The Mourners' Kaddish
Yit-gadal v'yit-kadash sh'may raba b'alma dee-v'ra che-ru-tay, ve'yam-lich mal-chutay b'chai-yay-chon uv'yo-may-chon uv-cha-yay d'chol beit Yisrael, ba-agala u'vitze-man ka-riv, ve'imru amen. Transliteration
Y'hay sh'may raba me'varach le-alam uleh-almay alma-ya.
Yit-barach v'yish-tabach, v'yit-pa-ar v'yit-romam v'yit-nasay, v'yit-hadar v'yit-aleh v'yit-halal sh'may d'koo-d'shah, b'rich hoo. layla (ool-ayla)* meen kol beer-chata v'she-rata, toosh-b'chata v'nay-ch'mata, da-a meran b'alma, ve'imru amen.
Y'hay sh'lama raba meen sh'maya v'cha-yim aleynu v'al kol Yisrael, ve'imru amen.
O'seh shalom beem-romav, hoo ya'ah-seh shalom aleynu v'al kol Yisrael, ve'imru amen.
* Add on Shabbat
Magnified and sanctified be G-d's great name in the world which He created according to His will. May he establish His kingdom during our lifetime and during the lifetime of Israel. Let us say, Amen. English
May G-d's great name be blessed forever and ever.
Blessed, glorified, honored and extolled, adored and acclaimed be the name of the Holy One, though G-d is beyond all praises and songs of adoration which can be uttered. Let us say, Amen.
May there be peace and life for all of us and for all Israel. Let us say, Amen.
Let He who makes peace in the heavens, grant peace to all of us and to all Israel. Let us say, Amen.
Thursday, 28 February 2013
The Mourners' Kaddish
In Loving Memory of Lillian Friedman, 1917-2013
The Mourners' Kaddish
Transliteration
Yit-gadal v'yit-kadash sh'may raba b'alma dee-v'ra che-ru-tay, ve'yam-lich mal-chutay b'chai-yay-chon uv'yo-may-chon uv-cha-yay d'chol beit Yisrael, ba-agala u'vitze-man ka-riv, ve'imru amen.
Y'hay sh'may raba me'varach le-alam uleh-almay alma-ya.
Yit-barach v'yish-tabach, v'yit-pa-ar v'yit-romam v'yit-nasay, v'yit-hadar v'yit-aleh v'yit-halal sh'may d'koo-d'shah, b'rich hoo. layla (ool-ayla)* meen kol beer-chata v'she-rata, toosh-b'chata v'nay-ch'mata, da-a meran b'alma, ve'imru amen.
Y'hay sh'lama raba meen sh'maya v'cha-yim aleynu v'al kol Yisrael, ve'imru amen.
O'seh shalom beem-romav, hoo ya'ah-seh shalom aleynu v'al kol Yisrael, ve'imru amen.
* Add on Shabbat
English
Magnified and sanctified be G-d's great name in the world which He created according to His will. May he establish His kingdom during our lifetime and during the lifetime of Israel. Let us say, Amen.
May G-d's great name be blessed forever and ever.
Blessed, glorified, honored and extolled, adored and acclaimed be the name of the Holy One, though G-d is beyond all praises and songs of adoration which can be uttered. Let us say, Amen.
May there be peace and life for all of us and for all Israel. Let us say, Amen.
Let He who makes peace in the heavens, grant peace to all of us and to all Israel. Let us say, Amen.
Tuesday, 26 February 2013
Kahn Artist: Truth or Consequence
Elyssa: "Did you call Lauren ? Did you at least send her a birthday card"
Karen CON: "After what Lauren did to me, I have no intention of ever contacting her again."
Just me,
e 📧@ELyssaD™ http://elyssadurant.com
http://powersthatbeat.com ^ed
Proponents of Canada’s Online Spying Bill Still Trying to Justify Excessive Powers | Electronic Frontier Foundation
Proponents of Canada’s Online Spying Bill Still Trying to Justify Excessive Powers | Electronic Frontier Foundation
https://www.eff.org/deeplinks/2012/07/proponents-canada-online-spying-bill-still-trying-justify-excessive-powers
Canada’s online surveillance bill may be on hold for now, but a recent news article confirms that a rather formidable figure has been angling for its return: Richard Fadden, head of the Canadian equivalent of the FBI. Fadden, director of the Canadian Security Intelligence Service (CSIS), wrote in a letter that the highly contentious Bill C-30 was “vital” to protecting national security. The letter was sent to Public Safety Minister Vic Toews, the driver behind Bill C-30, in late February. It was released to the Canadian Press in response to a request filed under the Access to Information Act.
As EFF has noted before, Bill C-30 would introduce new police powers allowing Canadian authorities easy access to individuals’ online activities, including the power to force Internet companies to hand over private customer data without a warrant. It would also pave the way for gag orders preventing online service providers from notifying subscribers that their private data has been disclosed — a move that would make it impossible for users to seek legal recourse for privacy violations.
Similar gag orders are frequently imposed in the United States, when the FBI issues national security letters (NSLs) seeking customer information. In a case EFF has taken on to challenge an NSL statute on behalf of a telecommunications company that received one of these secret letters in 2011, fundamental due process and First Amendment issues arising from these gag order provisions are a central concern.
Toews, the bill’s proponent, has made some outrageous claims about Bill C-30. Early on, he stated that opponents of the bill were either with him, “or with the child pornographers,” an apparent attempt to paint the legislation merely as a tool to combat online predators. Yet this framing of the issue was roundly rejected by stakeholders – as EFF reported back in February, internal documents reveal that even the government’s own analysts have claimed the powers in question were actually needed for non-criminal investigations.
Indeed, the legislation met with broad criticism across the board. Privacy Experts, academics, all of Canada’s Privacy Commissioners (and specifically the Federal, Ontario and British Columbia Commissioners), telecommunications companies, major Canadian newspapers, all opposition political parties, the Internet community, and more than 145,000 Canadians who signed an OpenMedia.ca petition spoke out against the legislation because they understood that it represented an unwarranted invasion of Canadians’ online privacy. The message seemed to get through: The legislation was ultimately placed temporarily on hold in the wake of the public outcry.
In spite of this, Fadden made it clear in his letter that he’s eager to see the bill return to Parliament. He offered to help draft revisions to the legislation to strengthen accountability measures, and stated that his agency is available “to support this process through all legislative stages.”
This did not come as a great surprise to Canadian privacy advocates. “CSIS has been a strong (but silent) supporter of the legislation for quite some time,” said Tamir Israel, of the Canadian Internet Policy and Public Interest Clinic (CIPPIC). “Unfortunately, [Fadden’s] statement … offers little that will make this legislation palatable to Canadians. CSIS already has very broad surveillance powers and they have yet to make the case that these new powers are, in fact, necessary for them to continue to do their job.”
Fadden’s focus on strengthening accountability fails to address the endemic problems in Bill C-30. British Columbia Privacy Commissioner Elizabeth Denham hit on the inherent problems with this approach in her assessment of prior government attempts to fix Bill C-30 by introducing stronger accountability:
I appreciate these changes attempt to improve the legislation. However, they remain premised on, and leave unaltered, the Bill’s fundamental flaw; that law enforcement can obtain an array of personal information about citizens, including real names, home addresses, unlisted numbers, email addresses and IP addresses from Internet service providers, without a warrant.
The Ontario Privacy Commissioner has also issued a detailed outline of what it would take to fix Bill C-30. And Denham’s perspective is shared by a broad cross-section of Canadians.
“If there’s one lesson Toews should have learned from the huge public outcry via the over 145,000+ who have spoken out through the StopSpying.ca petition and social media, it is that the government needs to make an effort to consult Canadians on issues relating to online privacy,” said Steve Anderson of OpenMedia.ca. “Canadians know this online spying bill will provide a range of authorities with the private information of any Canadian, at anytime, without a warrant. The fact is Vic Toews’ online spying plan is invasive, costly and poorly thought out.”
More recently, Toews claimed that Bill C-30 would have helped law enforcement apprehend accused killer Luka Magnotta, who has been charged in the gruesome murder of a Chinese university student. But Dr. Michael Geist, an expert in Internet and E-Commerce law and law professor at the University of Ottawa, immediately debunked this assertion:
“There is simply no question that law enforcement can obtain the necessary warrant on customer name and address information (if an ISP refused as part of an investigation) and police have presumably obtained warrants for far more detailed information. Moreover, the surveillance capabilities at ISPs mandated by C-30 - which focus on real-time surveillance - appear completely irrelevant given that Magnotta fled to France. In fact, reports indicate that there were early warnings about Magnotta and the video openly available that were dismissed by police.”
For his part, Israel characterized Toews’ statements as “more posturing from the Ministry of Justice and more crude attempts to leverage inflammatory issues in order to justify unnecessary and excessive powers.”
EFF continues to stand with Canadian privacy advocates who remain wary of Bill C-30’s return. We will continue to keep an eye on this legislation, which may be revisited once Parliament is back in session this coming fall.
(via Instapaper)
DarkNight II: "The Return of Durant"
DarkNight II: "The Return of Durant"
Too Old to Start Over, Too Young to Give Up.
By Elyssa Durant
Too old to start over, too young to give up. I often wonder why other people can uncover more information about my life than I can... Medical, Financial, Employment,,, even my next door neighbors are not somehow linked through the tiny web we have weave in cyberspace.
I'm a digger. To be clear, that is "digger." I never use the "N" word, and I'm way too proud to marry for money. I love information. I love to find, I love to collect it, but most of all, I love to use it. I love to dissect it, analyze it, formulate new questions and ponder the answers.
I love the journey of natural inquiry... never knowing where my racing mind will take me, often surprised surprised by the answer, but always, always intrigued by the things I encounter along the way.I may set out to find one answer to one question; only to find myself asking a million more.It keeps me up at night, and allows me to avoid the day.
My life is not unexamined, and my thought patterns may be far from typical, but the things I have learned along the way are by far the most intriguing and most unique.I am not afraid to ask questions, nor am I afraid that I don't have all the answers.
But as a digger, I do know that it is the path least taken: the creative, atypical mind that is riddled with creativity, tangential thoughts and questions that often deliver the most interesting answers. But sometimes, it is the answers that deliver us to the most interesting questions.
We often think that questions drive the inquiry-- at least that's what they tell us in school. To use the "scientific method"And of course, we are trained, and practiced to never, ever color outside the lines. But aren't the best discoveries the ones we weren't searching for? The unexpected gift... the non-occasion. Outside of the box?
Finding my voice has allowed me to appreciate the silence. The hours between dusk and dawn where the rest of the world sleeps and I dig. I dig and I write. I fill the lonely hours with my innermost thoughts, and my very best friend. So as the rest of the world sleeps soundly, surrounded by loved ones in a sanctuary they call home, I fill myself with books, journals and information.
Lots and lots of information. I love knowledge. I love the written word.The beauty is in the every day. The challenge is in the unexpected. Call me crazy if you like (and many have) but I can assure you that there will come a day when all of that R.A.M. will come in handy. I am definitely asking the right questions... and maybe one day you will too.
I never dreamed my life would turn out this way at the age of 35. It seems as though it was over before it even began. My birthday next month has pushed me a little further over the hill, and a little less tied to the past.I have a strong voice. A powerful voice.
I have a story that needs to be told. I am tired of being silenced by the Powers That Beat. I will not be ignored and I will not be forgotten.And though I may be too old to start over; I am definitely too young to give up.
ELyssa Durant © 2008-2013 || All Rights Reserved ELyssaD™
Google Online Security: An update on our war against account hijackers
An update on our war against account hijackers
Tuesday, February 19, 2013 9:13 AM
Have you ever gotten a plea to wire money to a friend stranded at an international airport? An oddly written message from someone you haven’t heard from in ages? Compared to five years ago, more scams, illegal, fraudulent or spammy messages today come from someone you know. Although spam filters have become very powerful—in Gmail, less than 1 percent of spam emails make it into an inbox—these unwanted messages are much more likely to make it through if they come from someone you’ve been in contact with before. As a result, in 2010 spammers started changing their tactics—and we saw a large increase in fraudulent mail sent from Google Accounts. In turn, our security team has developed new ways to keep you safe, and dramatically reduced the amount of these messages.
Spammers’ new trick—hijacking accounts
To improve their chances of beating a spam filter by sending you spam from your contact’s account, the spammer first has to break into that account. This means many spammers are turning into account thieves. Every day, cyber criminals break into websites to steal databases of usernames and passwords—the online “keys” to accounts. They put the databases up for sale on the black market, or use them for their own nefarious purposes. Because many people re-use the same password across different accounts, stolen passwords from one site are often valid on others.With stolen passwords in hand, attackers attempt to break into accounts across the web and across many different services. We’ve seen a single attacker using stolen passwords to attempt to break into a million different Google accounts every single day, for weeks at a time. A different gang attempted sign-ins at a rate of more than 100 accounts per second. Other services are often more vulnerable to this type of attack, but when someone tries to log into your Google Account, our security system does more than just check that a password is correct.
Legitimate accounts blocked for sending spam: Our security systems have dramatically reduced the number of Google Accounts used to send spam over the past few yearsHow Google Security helps protect your account
Every time you sign in to Google, whether via your web browser once a month or an email program that checks for new mail every five minutes, our system performs a complex risk analysis to determine how likely it is that the sign-in really comes from you. In fact, there are more than 120 variables that can factor into how a decision is made.If a sign-in is deemed suspicious or risky for some reason—maybe it’s coming from a country oceans away from your last sign-in—we ask some simple questions about your account. For example, we may ask for the phone number associated with your account, or for the answer to your security question. These questions are normally hard for a hijacker to solve, but are easy for the real owner. Using security measures like these, we've dramatically reduced the number of compromised accounts by 99.7 percent since the peak of these hijacking attempts in 2011.
Help protect your account
While we do our best to keep spammers at bay, you can help protect your account by making sure you’re using a strong, unique password for your Google Account, upgrading your account to use 2-step verification, and updating the recovery options on your account such as your secondary email address and your phone number. Following these three steps can help prevent your account from being hijacked—this means less spam for your friends and contacts, and improved security and privacy for you.(Cross-posted from the Official Google Blog)
Google : rel="nofollow"
rel="nofollow"
support.google.com
- March 14th, 2012
- view original
Watch an explanation of rel="nofollow""Nofollow" provides a way for webmasters to tell search engines "Don't follow links on this page" or "Don't follow this specific link."
Originally, the
nofollowattribute appeared in the page-level meta tag, and instructed search engines not to follow (i.e., crawl) any outgoing links on the page. For example:<meta name="robots" content="nofollow" />Before
nofollowwas used on individual links, preventing robots from following individual links on a page required a great deal of effort (for example, redirecting the link to a URL blocked in robots.txt). That's why thenofollowattribute value of therelattribute was created. This gives webmasters more granular control: instead of telling search engines and bots not to follow any links on the page, it lets you easily instruct robots not to crawl a specific link. For example:sign inHow does Google handle nofollowed links?
In general, we don't follow them. This means that Google does not transfer PageRank or anchor text across these links. Essentially, using
nofollowcauses us to drop the target links from our overall graph of the web. However, the target pages may still appear in our index if other sites link to them without usingnofollow, or if the URLs are submitted to Google in a Sitemap. Also, it's important to note that other search engines may handlenofollowin slightly different ways.What are Google's policies and some specific examples of nofollow usage?
Here are some cases in which you might want to consider using
nofollow:
- Untrusted content: If you can't or don't want to vouch for the content of pages you link to from your site — for example, untrusted user comments or guestbook entries — you should nofollow those links. This can discourage spammers from targeting your site, and will help keep your site from inadvertently passing PageRank to bad neighborhoods on the web. In particular, comment spammers may decide not to target a specific content management system or blog service if they can see that untrusted links in that service are nofollowed. If you want to recognize and reward trustworthy contributors, you could decide to automatically or manually remove the
nofollowattribute on links posted by members or users who have consistently made high-quality contributions over time.- Paid links: A site's ranking in Google search results is partly based on analysis of those sites that link to it. In order to prevent paid links from influencing search results and negatively impacting users, we urge webmasters use
nofollowon such links. Search engine guidelines require machine-readable disclosure of paid links in the same way that consumers online and offline appreciate disclosure of paid relationships (for example, a full-page newspaper ad may be headed by the word "Advertisement"). More information on Google's stance on paid links.- Crawl prioritization: Search engine robots can't sign in or register as a member on your forum, so there's no reason to invite Googlebot to follow "register here" or "sign in" links. Using
nofollowon these links enables Googlebot to crawl other pages you'd prefer to see in Google's index. However, a solid information architecture — intuitive navigation, user- and search-engine-friendly URLs, and so on — is likely to be a far more productive use of resources than focusing on crawl prioritization via nofollowed links.How does nofollow work with the Social Graph API (rel="nofollow me")?
If you host user profiles and allow users to link to other profiles on the web, we encourage you to mark those links with the rel="me" microformat so that they can be made available through the Social Graph API. For example:
My blogHowever, because these links are user-generated and may sometimes point to untrusted pages, we recommend that these links be marked with nofollow. For example:
My blogWith
rel="me nofollow", Google will continue to treat therel="nofollow"as expected for search purposes, such as not transferring PageRank. However, for the Social Graph API, we will count therel="me"link even when included with anofollow.If you are able to verify ownership of a link using an identity technology such as OpenID or OAuth, however, you may choose to remove the
nofollowlink.To prevent crawling of a rel="me nofollow" URL, you can use robots.txt. Standard robots.txt exclusion rules are respected by both Googlebot and the Social Graph API.
Does exposure to an artificial ULF magne... [Biomed Pharmacother. 2004] - PubMed - NCBI
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Biomed Pharmacother. 2004 Oct;58 Suppl 1:S20-7.Does exposure to an artificial ULF magnetic field affect blood pressure, heart rate variability and mood?
Source
Division of Neurocardiology and Chronoecology, Tokyo Women's Medical University, Daini Hospital, Tokyo, Japan.
Abstract
The aim of this study was to determine whether an artificial magnetic field with an amplitude and frequency equivalent to those of geomagnetic pulsations during geomagnetic storms could affect physiology and psychology. Three healthy volunteers wore anambulatory BP monitor and an ECG recorder around the clock for 12 consecutive weekends in Winnipeg, Manitoba, Canada. In a room shielded against ELF and VLF waves, they were exposed for 8 hours per week to either a 50 nT 0.0016 Hz or a sham magnetic field at one of six circadian stages. Real exposure randomly alternated with sham exposure. They provided saliva and recorded mood and reaction time every 4 hours while awake. Systolic (S) and diastolic (D) blood pressure (BP), and heart rate (HR) were recorded every 30 minutes. Spectral analysis of HR variability (HRV) was performed using the maximum entropy method and a complex demodulation method. For these variables, daily means were compared between real and sham exposure, using paired t-tests. Their circadian MESOR, amplitude, and acrophase were analyzed and summarized using single cosinor and population-mean cosinor. Circadian rhythms were demonstrated for HR, SBP, DBP for sham exposure, salivary flow rate, positive affect, vigor, and subjective alertness (p < 0.001, -0.02). One participant showed higher HR, lower LF, HF, and VLF powers, and a steeper power-law slope (p < 0.005, -0.0001) in an early night exposure to the real magnetic field, but not in other circadian stages. There was no significant difference between circadian responses to real and sham exposure in any variable at any circadian stage.
Monday, 25 February 2013
How to Recover Deleted Text Messages From iPhone Using Textpad
I thought you might be interested in reading this:
How to Recover Deleted Text Messages From iPhone Using Textpad
If you delete a text message on an iPhone, that message is gone forever, unless you have recently backed up your iPhone to your computer. If you have a recent backup of your iPhone saved on your computer, you can use the TextPad application to locate and recover the text message you deleted....
Sent from eHow
Does exposure to an artificial ULF magne... [Biomed Pharmacother. 2004] - PubMed - NCBI
Biomed Pharmacother. 2004 Oct;58 Suppl 1:S20-7.Does exposure to an artificial ULF magnetic field affect blood pressure, heart rate variability and mood?
Source
Division of Neurocardiology and Chronoecology, Tokyo Women's Medical University, Daini Hospital, Tokyo, Japan.
Abstract
The aim of this study was to determine whether an artificial magnetic field with an amplitude and frequency equivalent to those of geomagnetic pulsations during geomagnetic storms could affect physiology and psychology. Three healthy volunteers wore anambulatory BP monitor and an ECG recorder around the clock for 12 consecutive weekends in Winnipeg, Manitoba, Canada. In a room shielded against ELF and VLF waves, they were exposed for 8 hours per week to either a 50 nT 0.0016 Hz or a sham magnetic field at one of six circadian stages. Real exposure randomly alternated with sham exposure. They provided saliva and recorded mood and reaction time every 4 hours while awake. Systolic (S) and diastolic (D) blood pressure (BP), and heart rate (HR) were recorded every 30 minutes. Spectral analysis of HR variability (HRV) was performed using the maximum entropy method and a complex demodulation method. For these variables, daily means were compared between real and sham exposure, using paired t-tests. Their circadian MESOR, amplitude, and acrophase were analyzed and summarized using single cosinor and population-mean cosinor. Circadian rhythms were demonstrated for HR, SBP, DBP for sham exposure, salivary flow rate, positive affect, vigor, and subjective alertness (p
Joined in death, love is stronger than stone אברהם לילאן
That which is so is so universal as death must be a blessing
Joined in death, love is stronger than stone.
May you rest in peace for eternity.
With love,
ELyssa Danielle
Sunset Prayer at Cemetary Gates
Several years ago, someone told me that Grandpa was not my "real" grandfather.
Looking back now, I know that was not true. Grandpa was one thing in my life that was, in fact, very, very real.
My grandfather embodied all things constant: consistency, reliability, and unconditional love. I could always depend on him to be there for me: as a child, a young woman, and an adult.
So now I ask myself and all of you to help me define what is "real?" I believe you will come to understand it as I have: "real" is something or someone we can touch; something we can feel.
My grandfather was a man I could trust, a man I could admire, and a man who stood up for what he believed in. My grandfather was, in fact, a man that was so real that he could single-handedly turn dreams into realities.
When I was little, I used to go to my grandparent's when I was too sick to go to school. Grandma would load me up with tea and cheese and Grandpa would load me up with Vitamin C.
As I got older, he continued to care for me. When I was hungry, he sent me food; when I was cold, he sent me clothing. When I was sick, he sent me more vitamins!
When I was scared, he gave me courage; when I was lonely, he gave me shelter; when I was sad, he gave me hope.
He was a man of action, a man of honor, and a man of truth. But most of all, he was a man of integrity. He was a man who exemplified all things wonderful that life had to offer.
He was generous beyond reason and he gave me those things in life money simply cannot buy: he gave me roots, he gave me foundations, and most importantly, he gave me wings.
Rest in peace, Grandpa. You were loved.
Read more:
ELyssa Durant © 2008-2013 || All Rights Reserved ELyssaD™ || DailyDDoSe™ @ELyssaD™
- Relatively speaking: What is "real?"
- Does DNA alone define who you are? Where you came from? A relationship?
- Blood is not always thicker than water.
Just me,
e
@ELyssaD™
http://elyssadurant.com
http://powersthatbeat.com
^ed
Are stress responses to geomagnetic storms mediated by the cryptochrome compass system?
Are stress responses to geomagnetic storms mediated by the cryptochrome compass system?
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3321722/
Abstract
A controversial body of literature demonstrates associations of geomagnetic storms (GMS) with numerous cardiovascular, psychiatric and behavioural outcomes. Various melatonin hypotheses of GMS have suggested that temporal variation in the geomagnetic field (GMF) may be acting as an additional zeitgeber (a temporal synchronizer) for circadian rhythms, with GMS somehow interfering with the hypothesized system. The cryptochrome genes are known primarily as key components of the circadian pacemaker, ultimately involved in controlling the expression of the hormone melatonin. Cryptochrome is identified as a clear candidate for mediating the effect of GMS on humans, demonstrating the prior existence of several crucial pieces of evidence. A distinct scientific literature demonstrates the widespread use of geomagnetic information for navigation across a range of taxa. One mechanism of magnetoreception is thought to involve a light-dependent retinal molecular system mediated by cryptochrome, acting in a distinct functionality to its established role as a circadian oscillator. There is evidence suggesting that such a magnetosense—or at least the vestiges of it—may exist in humans. This paper argues that cryptochrome is not acting as secondary geomagnetic zeitgeber to influence melatonin synthesis. Instead, it is hypothesized that the cryptochrome compass system is mediating stress responses more broadly across the hypothalamic–pituitary–adrenal (HPA) axis (including alterations to circadian behaviour) in response to changes in the GMF. Two conceptual models are outlined for the existence of such responses—the first as a generalized migrational/dispersal strategy, the second as a stress response to unexpected signals to the magnetosense. It is therefore proposed that GMS lead to disorientation of hormonal systems in animals and humans, thus explaining the effects of GMS on human health and behaviour.
1. Introduction
(a) Geomagnetic navigation in animals
The geomagnetic field (GMF) conveys orientational and positional information of substantial utility to migrating animals. Magnetoreception is thought to exist across a phylogenetically widespread array of taxa, including molluscs, insects, bony fish, amphibians, bats, rodents, artiodactylans, cetaceans, carnivorans and avian species (there are many good reviews [–]). Geomagnetic senses have a small overall physiological footprint and are redundantly integrated with other navigational and sensory stimuli in a complex fashion. For these reasons, they have often confounded scientific investigation, and it is only over the last few decades that their mechanisms and functionality have started to become elucidated. The majority of well-studied magnetodetection systems can be broadly divided into two categories: permanent ferromagnetic crystals normally found in the ethmoid sinuses of vertebrates, or a cryptochrome-mediated radical-pair based paramagnetic detection located in the eye. Many bird species appear to have both systems working in tandem to produce a detailed magnetic map. These senses appear to be extremely sensitive—in order for the magnetic map to function, birds must be able to detect naturally occurring local changes in magnetic field strength that are down to perhaps 10 nT, equivalent to just a few miles or less []. Thresholds in the region 10–200 nT have been shown experimentally in birds and honeybees, and inferred for homing pigeons and whales [].
(b) Cryptochrome-based magnetodetection
The radical-pair mechanism has been proposed as one of only a few molecular features that might plausibly be influenced by the Earth’s magnetic field [], with the yield of a biochemical reaction proceeding via a spin-correlated radical-pair-based reaction being sensitive to the orientation of an external magnetic field. A later theoretical refinement of the model proposed that the retina is well suited as an ordered structure for an array of molecules configured in various alignments with the GMF [], with the product of the radical pair intermediate detected by the existing visual reception system. It was also hypothesized that cryptochrome was the most promising candidate molecule—it is the only known photoreceptor in vertebrates shown to be able to form a radical pair upon photoexcitation []. Mounting inferential evidence now supports a role for cryptochrome in avian magnetodetection: the hypothesized eye-localized, paramagnetic cryptochrome-based magnetodetection has a series of biophysical signatures, including (but not limited) to the following (for references and a more complete discussion, see reviews, [–,]): (i) Gene expression profile: a high cytosolic localization of cryptochrome in avian retinal ganglion cells and co-localization with neuronal activity markers during magnetic orientation suggests a role of cryptochrome as a magnetic compass detector (beyond its established role as a circadian oscillator) []. (ii) The avian compass is an inclination compass: the radical-pair method is known to operate as an inclination compass (directional information is derived from the inclination of the field lines rather than their polarity). An inclination compass has been documented for geomagnetic navigation in every bird species tested, also revealing a corresponding insensitivity to polarity. (iii) Geomagnetic navigation involves the eyes and is light-dependent: the cryptochrome model proposes that magnetoreception involves photon absorption as a first step for creation of radical pairs, and therefore predicts that geomagnetic navigation will be dependent on a specific wavelength of light. It has been shown that magnetic orientation is wavelength dependent under low-intensity monochromatic light, with birds orientating well under blue wavelength, but are generally challenged under red wavelengths. (iv) Sensitivity to oscillating magnetic fields in the low radio-frequency range: these fields are expected to affect radical-pair reactions and compete with the effects of the GMF, but would not interfere with magnetite-based magnetodetection. Experiments with such fields have been shown to disrupt magnetic orientation behaviour of migratory birds. These results provide the strongest, albeit indirect, evidence that the biophysical mechanism underlying the magnetic compass of birds involves the radical-pair reaction, with such effects hard to reconcile with other mechanisms.
(c) A human magnetosense?
Somewhat surprisingly, while a human magnetosense is not widely accepted, there is accumulating evidence to suggest that such a sense—or at least the vestiges of it—may exist. It has recently been proposed that magnetoreception may be a general feature of at least mammals [4], and also that animals without a magnetosense may be the exception, rather than the rule []. The majority of human evolution involved migrational or nomadic lifestyles until the onset of sedentarization around 10 000 years ago [], providing a clear functional utility for such a sense. In 1987, a meta-analysis of several studies directly testing for human geomagnetic orientation revealed a statistically significant result []. Recent studies with more sophisticated experimental design have confirmed these results, revealing that weak magnetic fields can trigger evoked potentials in human subjects []. Further human experimental studies have revealed that the visual sensitivity of man is influenced by changes to the GMF [], interpreted as supporting evidence for the radical-pair retinal model in humans. Further publications have revealed that the fundamental biological components for magnetoreception are present in humans. Ferromagnetic structures have been identified in human sinuses []. Moreover, recent experiments with Drosophila have revealed that the human cryptochrome CRY2 gene has functional magnetoreceptive abilities []. These experiments involved entraining Drosophila to navigate using a magnetic field, with the response shown to be blue-light dependent, thus implicating cryptochrome []. Moreover, cryptochrome-knockout Drosophila could not navigate in response to the magnetic field, providing the first direct evidence for the role of cryptochrome in magnetic navigation. In a subsequent transgenic experiment, the human cryptochrome CRY2 gene was revealed to rescue the magnetic navigation abilities of the knockout Drosophila, thus revealing that the human gene is functionally magnetosensitive [].
(d) Geomagnetic storms
The GMF has a maximum field strength of around 70 µT at the geographical poles (where the field is near vertical) to less than 30 µT at the geomagnetic equator (where the field is parallel to the terrestrial plain). Coronal mass ejections can occasionally be directed towards the Earth. These can deliver a huge number of high-energy ions to the ionosphere, which are sufficient to cause relatively minor alterations to the strength and the direction of the magnetic field. Such events are dubbed ‘geomagnetic storms’ (GMS). These global disturbances can last from several hours to days, with the literature generally defining a geomagnetic storm as involving 24 h planetary average changes to the GMF of as little as around 30 nT [–]. Such storms occur on average once every 10 days or so, but do not occur with an even distribution. Instead, solar activity reveals a number of quasi-periodic oscillations, the most prominent of which is the approximately 11.5 year solar cycle. Furthermore, GMS tend to be more frequent at the equinoxes, and more extreme at higher latitudes [,].
(e) Geomagnetic storms and human health
A large, complex, and often controversial body of literature has linked elevated geomagnetic activity (GMA) with a range of human psychological, neurological, cardiovascular (CV), immunological and behavioural outcomes (see electronic supplementary material, table). The roots of this literature [] lies with Russian biological science, where studies revealed a number of health associations of GMS of various strength and reproducibility, with many of these associations since investigated in the Western literature []. Owing to space constraints, selected evidence for the key findings is outlined below. However, the electronic supplementary material, table includes a detailed reference list.
While early Western studies on the CV system were controversial with some notable negative results [] and a retraction [], later studies have revealed positive associations of GMS with myocardial infarction, stroke, blood pressure, capillary blood flow and an inverse correlation with heart rate variability (HRV) [18„,]. One study observed that in years of peak GMS activity, patients admitted for myocardial infarction increased 25 per cent []; other studies have reported a similar relationship, accounting for a 5 per cent increase in mortality in maximal solar years []. Moreover, these epidemiological studies are supported by evidence from both human [,] and animal [,] physiological studies that reveal changes to blood pressure and HRV in relation to geomagnetic disturbances.
With regard to the psychiatric literature, associations have been revealed between GMA and increased hospitalizations for depression [] and ambulance callouts for mental disorders in general [], with one well-cited study reporting an increase of 36 per cent in hospital admissions for males with a diagnosis of depression during periods of high GMA []. However, such psychiatric findings have not always been repeated and remain somewhat contentious (see electronic supplementary material, table and [18,] for discussion).
Associations have also been demonstrated across wider health studies, correlating GMA with the total number of deaths []. Correlations have also been reported between solar cycles and longevity [], although such findings remain equivocal []. A further series of studies have revealed associations between the solar cycle and flu pandemics [], and a similar relationship was recently reported with papillomavirus infections []. Relationships have also been observed between GMA and sudden infant death syndrome [] and epilepsy [].
One of the few large literature reviews on GMS made the definite conclusion that GMA has an effect on human CV health, and the less certain conclusion that there may be an association between GMA and admissions for mental illness [18]. A review of the vast Russian magnetobiology literature concluded that ‘the totality of the matter described here strongly supports the hypothesis that the GMF disturbances correlate with the general human condition’ []. Associations of GMA with certain parameters—in particular, the CV system and melatonin suppression—are now so heavily reproduced that the associations themselves are not necessarily the subject of controversy. Rather, the fundamental question now relates to causation versus correlation. However, the obvious confounders—seasonality and latitude—are often controlled for, and the results have often been confirmed in various human and animal physiological studies both during GMS and using applied Earth-strength magnetic fields (electronic supplementary material, table). Therefore, serious consideration has been applied to a rational biological basis for these associations.
(f) The melatonin hypothesis of geomagnetic storms
A plausible mechanism of biological action of GMS has confounded biological sciences for decades—one of the primary reasons why the above findings are often treated with caution. When searching for rational explanations for the aetiology of GMS, a striking feature is their small magnitude—as little as 0.1 per cent or less of the background GMF, with typical directional changes of the field a fraction of a degree. This poses a significant problem when considering plausible biophysical mechanisms. While numerous models have been proposed (see [18„] for discussion), most remain unclear and unsubstantiated by evidence. However, a series of hypotheses that argue a role for melatonin and the circadian system have gained the most widespread support [,,18„„,].
Light is detected by the non-classical photoreceptor melanopsin in the eye, with the photic information conveyed to the suprachiasmatic nucleus (SCN), where it acts as the principal environmental synchronizer of the master mammalian circadian pacemaker, and is used to modulate coupled transcription/translation feedback loops [–]. This involves a molecular oscillator of several components including the Period genes (PER1, PER2 and PER3) and cryptochrome genes (CRY1 and CRY2). The SCN acts as master pacemaker that regulates many functions throughout the organism including endocrine functions (including melatonin and glucocorticoids), behavioural outputs (body temperature, sleep/wake cycles), metabolism and liver function. The pineal gland is the source of circulating melatonin, plasma concentrations of which are higher during the biological night than the day, and it is fundamentally involved in regulating the sleep–wake cycles. Retinal exposure to light at night, via the above outlined pathways, produces short-term suppression of night-time melatonin secretion in an intensity-dependent manner, which can result in the modulation of normal circadian rhythms.
The previously proposed melatonin hypothesis of GMS [„18„„,42] is predicated on observations that GMA or applied magnetic fields in the geomagnetic range have been associated with lower mean nocturnal melatonin secretion (or its major metabolite 6-hydroxymelatonin-sulfate: 6-OHMS) in studies of both healthy individuals and CV patients [„,,]. Such findings have been confirmed in animal experimental studies [–], although some negative results have been obtained [,] (see electronic supplementary material, table). Moreover, melatonin plays a central role in the regulation of diverse biological functions, and the other observed relationships of GMA (e.g. CV, psychiatric and immunological) all concern traits that are possibly influenced downstream by the effects of melatonin disturbance []. For example, there is evidence for the involvement of melatonin in various cardiopathologies [,]. Previous authors have therefore suggested that the influences of GMA on the CV system could be via a disruption of melatonin synthesis [„,], with the effects transmitted to the CV system via melatonin action on the adrenal gland influencing glucocorticoid and cortisol production []. With the psychiatric findings, it has recently been suggested that the circadian system may be more directly involved in the aetiology of psychiatric disorders []. Marked changes are observed in the circadian systems of psychiatric patients [], and circadian clock genes (including CRY2 []) have been associated with almost all neuropsychiatric disorders, albeit with some conflicting results []. Disrupted melatonin action could have further widespread deleterious effects on human health: it is an immunoenhancing modulator (thereby potentially influencing influenza and other infections) [], is known to act as an anti-oxidant [], is an endogenous anticonvulsant (thereby potentially influencing epilepsy) [] and has been linked with sudden infant death syndrome [].
While there is evidence of melatonin suppression in response to changes in the GMF, fundamental questions remain concerning the putative biophysical and molecular basis for such associations and the underlying biological rationale for such circadian behaviour. Below, the evidence for the melatonin hypothesis is disinterred, reframed within the context of recent work on geomagnetic navigational magnetoreception, and extended: first, to hypothesize a specific biological candidate, and secondly, to hypothesize a novel but plausible theoretical framework.
2. Cryptochrome as the prime candidate for the effects of geomagnetic storms on humans
Cryptochrome immediately presents itself as the prime candidate for a role linking GMS with the circadian system: of its two established functions, one is to act as a geomagnetic compass, the other is to act as a circadian oscillator. However, this is perhaps a somewhat naive appraisal of cryptochrome, as these roles are thought to be entirely distinct. During preparation and review of this manuscript, cryptochrome has, in a related manner, been suggested as a candidate gene underlying the observed relationships between the solar cycle and influenza pandemics [] and suggested as the candidate for the controversial effects of anthropogenic sources of EMFs on human health [,]. These reviews are an ideal complement to this paper owing to their distinct focus (see also the electronic supplementary material for further discussion of PF-EMFs).
(a) The evidence for cryptochrome
(i) Similarity of human and avian expression of cryptochrome. Quantitative RT-PCR and immunohistochemistry of human tissue revealed a relative abundance of CRY2 transcripts localized to the inner retina and that it is also localized within the cytoplasm of some cells in the ganglion cell layer []. This originally led to suggestions that cryptochrome may perform a secondary retinal function of photo-entrainment of the circadian system. However, it is now known that melanopsin, rather than CRY2, primarily performs such a role [], although some photo-entraining functionality of CRY2 cannot be excluded. Instead, it should be highlighted that this expression profile is similar to avian species, where CRY1 has also been shown to have a high cytosolic expression in ganglion cells (see electronic supplementary material, figure for visual comparison). This same expression, in avian species, has been inferred as evidence for the involvement of cryptochrome in magnetodetection [,]. (ii) The human CRY2 gene is a magnetosensitive molecule. These expression data are complemented by the above-mentioned Drosophila transgenic experiments, which established that the human CRY2 gene is a magnetosensitive molecule []. Both the location and functionality of CRY2 in humans are therefore consistent with a geomagnetic sensing role in humans. (iii) Evidence that melatonin responses to changes in the GMF are transmitted via the eye. A series of animal experiments provide evidence that the visual system is involved when melatonin is suppressed owing to magnetic disturbances. While applied Earth-strength magnetic stimulus significantly reduces the pineal activity and melatonin expression of rats, acutely blinded rats reveal no such response []. The authors concluded that this suggests a retinal magneto-sensitivity which may serve to modulate pineal function. However, a pineal magnetosensitivity cannot be excluded based on such data, as this may require a light signal as a trigger. (iv) Evidence that melatonin response to changes in the GMF are light-dependent. Further animal experiments revealed that dim light is necessary to mediate the effects of the Earth-strength magnetic stimulus on pineal enzyme activity [], with other animal studies also revealing interactions of light with the EMF []. However, it was revealed that the red light is sufficient to mediate the geomagnetic influence on the circadian system []. This finding is perhaps contrary to a role of cryptochrome in mediating these relationships—a blue-wavelength-specific response would be expected []. However, this could also be representative of an additional layer of complexity. Magnetoreception in nocturnal newts has been revealed to be dependent on yellow-red wavelength light, corresponding to moonlight-dependent magnetoreception [], and some bird species appear to have multiple magnetic compass receptors operating at different wavelengths of light []. In humans, a series of studies have revealed a relationship between light exposure with both geomagnetic [,] and anthropogenic magnetic fields [–]. The authors argued that the reduction in 6-OHMS excretion associated with geomagnetic and electromagnetic activity may depend on low levels of ambient light. However, findings with anthropogenic EMFs remain extremely controversial, with the majority of studies producing negative results (see WHO [40] and discussion in the electronic supplementary material). (v) Cryptochrome transgenic experiments. Experiments with Drosophila revealed that applied magnetic fields influenced their circadian behaviour, and that this response was again blue-light-dependent []. Moreover, cryptochrome-knockout Drosophila did not show such a response, whereas flies overexpressing cryptochrome revealed an enhanced response. These experiments therefore provide initial direct evidence that cryptochrome is involved with transmitting magnetic field effects to the circadian system. The authors discuss the results within the context of cryptochrome acting as a secondary zeitgeber for the circadian system.
(b) The geomagnetic field as a secondary zeitgeber?
Several authors have previously argued that the GMF acts as a secondary zeitgeber of circadian rhythms, in addition to the primary synchronizer of the day–night-light cycle. This could operate via Schumann resonance signals [] or the reduced variation in the magnetic field at night [42]. The electromagnetic field of 10 Hz exhibits diurnal variations [], and it has been demonstrated that several organisms—including humans [], mice [] and Musca flies []—can have their circadian behaviour influenced or entrained by applied 10 Hz magnetic fields. However, there are issues with theories of the GMF as a secondary zeitgeber. There is a questionable utility of a variable secondary zeitgeber when working alongside a reliable primary synchronizer (e.g. day-light cycle). Moreover, numerous experiments have already revealed that when various species [,72,,] are kept under constant lighting conditions, their circadian rhythms become free-running and decoupled from the usual 24 h cycle, i.e. they do not resort to a secondary daily geomagnetic synchronizer in the absence of the primary synchronizer. For example, the free-running circadian rhythm of humans was found to be 24.87 h in a natural geomagnetic environment (whereas under geomagnetically shielded conditions, it was demonstrated to be a significantly longer length of 25.26 [72]). Although the experimental environment may be interfering with daily variations in the natural GMF in some of the above studies, it has been established that daily variations in the GMF across different animal facilities are essentially similar and omnipresent []. Thus, while the above studies confirm the influence of the GMF on the circadian system, no study has experimentally established that the natural GMF can act as a reliable zeitgeber. Instead, an alternative explanatory framework is proposed.
3. Magnetosense–HPA interactions: two models
(a) A generalized model of migratory-dispersal strategies
Migrating birds display a number of stressful physiological adaptations to long journeys with low food availability and high predation—an often nocturnal migration, reduced melatonin amplitude, increased metabolism, higher body temperature and increased energy expenditure []. However, just as the magnetosense is now thought to be a rather more common feature of animals than was previously considered, modern definitions of migration are much more inclusive than past interpretations []. The majority of species are now considered to exhibit life-history strategies that involve territoriality and home-ranges punctuated by periodic long-distant dispersals [], which can occur for a plethora of reasons (e.g. resource availability, seasonal excursions, mating etc.) Such migrations represent a stressful phase mirrored by similar hormonal and behavioural adaptations to bird navigation, also mediated by the HPA axis []. While migrational life-history strategies are under complex control and poorly understood in birds and other animals, a relationship with navigational behaviour is implicated []. Therefore, in animals using the GMF for navigation, relationships are expected between the GMF and migrational behaviour. Given the apparent widespread existence of both long-distance dispersals and the magnetosense, hypothesized interactions between the GMF, migratory behaviour and hormonal control are possibly generalizable. In migratory birds, recent research has established that simulated GMFs influence hormonal secretion and migrational behaviour, with the elicited responses being related to specific adaptations of planned long-distant migrations such as fuelling and metabolic strategies [,]. In contrast to these specific strategies, unplanned dispersals in non-migratory animals might instead be expected to elicit a generalized stress reaction mediated across the HPA axis in response to unknown environments with subsequent risks such as low-resource availability and high predation. It is perhaps noteworthy that the above investigations on birds represent rare examples of animal experiments where hormonal responses to simulated MFs are as predicted by theory. Could the existing data relating changes in the GMF (either GMS or applied MFs) to hormonal behaviour in animals be appraised under a similar paradigm?
(b) A generalized model of stress responses of sensory systems
It has recently been suggested that in addition to simply providing compass information, the cryptochrome magnetosense provides a spherical coordinate system that serves to interface metrics of distance, direction and spatial position []. Magnetodetection could thereby provide a global reference system used to place local landmark arrays into a register with the local maps of other areas, to increase the accuracy of a path integration system, to define directional relationships between landmarks, and also to specify spatial locations within the landmark array. Such theories are controversial and to date there is no compelling experimental evidence (see [] for discussion and references). However, observations with mole-rats have established that the magnetic sense is no different to the other senses, and is involved in multi-sensory integration with other inputs (e.g. vestibular, visual, etc.) []. Similarly, magnetically responsive activity has been identified in the nucleus of the basal optic root of birds, where the information is thought to interact with vestibular inputs []. Moreover, gravitational cues—derived from the vestibular system—play an essential role in cryptochrome-based magnetodetection, providing a vertical reference used to resolve the ambiguity inherent to a polarity-independent device []. When the vestibular system is exposed to extreme vestibular stimuli, such as hypogravity, hypergravity, horizontal or angular accelerations, there is an elicited acute stress response activated across the HPA axis [,], with the vestibular system being implicated in a variety of physiological and behavioural functions including modulation of circadian rhythmicity []. Furthermore, there is anatomical evidence for the existence of neuronal connections between the vestibular system to the SCN [] and hypothalamic paraventricular nucleus (PVN) []. Thus, there exists a clear precedent for hypothesized interactions between a magnetosense and the HPA axis. Therefore, rather than stress responses of the magnetosense having evolved as a migrational strategy per se, as proposed above, such connections could instead be invoked as a response to extreme or unexpected signals. Such signals could degrade the proposed magnetodetective components of path integration systems [] cause navigational disorientation, and therefore elicit a general stress response similar to those observed with the vestibular system.
Both of the above models are functionally related, involving stress responses in relation to novel, extreme or unexpected signals, and are treated as largely equivalent below. The first model appraises magnetosense–HPA interactions under classical and experimentally verified notions of the magnetosense as a primarily migrational device. However, the magnetosense is thought to have a maximum resolution of perhaps a few miles []. Therefore, in animals with limited dispersal ranges, it is difficult to envisage a geomagnetic component of dispersal-stress behaviour. In contrast, the second model appraises interactions of magnetosense–HPA interactions under more modern (but experimentally unverified) theoretical models [], but as such is more widely generalizable across the animal kingdom. In fact, both models could coexist in some animals. It is therefore proposed that information from the magnetosense—known to be integrated in a hierarchical and complex fashion with the other senses [–]—is used in a series of related hormonal functionalities that are optimized according to the navigational, migrational or dispersal strategies of the organism.
(c) Geomagnetic storms as nature’s experiment: spoofing the system?
The magnitude of GMS can dwarf the local variation in the GMF [40], and are known to cause disruptions to human navigational systems. Similarly, GMS have been suggested to cause navigational disorientation in the animal kingdom, including bees [], birds [] and whales []. In a similar manner, experimental evidence has revealed that altered magnetic field conditions can introduce significant changes in rodent directional and spatial circuits []. According to either of the above models, GMS would introduce signals that are incorrect—yet coherent—to the magnetosense and associated navigational behaviour. If the magnetosense also has the above proposed interactions with hormonal systems, then GMS would subsequently lead to disorientation of hormonal behaviour across the HPA axis. In fact, the action of GMS on humans have been previously interpreted as such a generalized stress response [,], with correlates largely mirroring those of a stress responses [], involving CV pathologies, circadian disturbances, neuropsychiatric manifestations, immunological responses and apparently widespread alterations in neuroendocrine markers [,–] (see electronic supplementary material, table). Therefore, the ‘melatonin hypothesis’ of GMS would be a somewhat limited paradigm, with GMF–melatonin interactions being just one of a set coordinated hormonal responses.
In contrast to GMS, the interactions of the magnetosense with PF-EMFs is likely to be complex, depending on factors such as field strength, frequency, timing, duration, polarization, lighting conditions, the relative changes and duration of such sources, in addition to possible temporal window effects and the age of the organism. However, as MF frequencies and strength approach the geomagnetic range and intensity, it might be expected that findings would become generally more positive, and it is interesting to speculate how the hypothesized magnetosense–HPA interactions might relate to the highly controversial literature on the influence of PF-EMFs on biological systems (see the electronic supplementary material and [,] for further discussion). Nonetheless, there is evidence that the compass system of at least some animals does react to PF-EMFs—overhead high-voltage power lines disrupt the normal northsouth alignment of ruminants with the GMF [].
(d) Reappraising the existing data under the framework of magnetosense–HPA interactions
It is observed that the apparent sensitivity of melatonin suppression in response to GMS (becoming significant at around 15–80 nT [„„„]) mirrors the apparent sensitivity of the compass system (in the range of 10–200 nT []). Furthermore, many previous publications have interpreted findings with GMS under the assumption that there is some specific component of GMS that is important (e.g. Schumann resonances [71] or pc1 pulsations [24]), whereas under the current framework, it is simply the change in the usual GMF that is sufficient to elicit responses. This is supported by evidence from laboratory animal studies that it is indeed the change in applied MF that is important, rather than the main stimulus itself—removing the stimulus and returning animals to the natural GMF also produces the observed reductions in melatonin [].
It should be noted that the GMF is used by migrating animals in a complex, hierarchical and redundant manner, being of particularly utility in the absence of other navigational stimuli (e.g. sun, moon, stars and landmarks) [–]. Such hierarchical utilization of sensory input may also be reflected in the above-proposed magnetosense–HPA interactions, and the effects of GMS may therefore be particularly acute in the absence of other cues, e.g. when navigating in new or visually homogenous environments. A further related situation occurs while sleeping, owing to the absence of wakeful navigational information. Therefore, when sleeping in a geomagnetically unfamiliar environment (i.e. representing a dispersal from the home range), it would be evolutionary rational to attenuate sleep behaviour. Such speculations are consistent with apparent night-to-night temporal window effects for the influence of GMS on melatonin [„,]. In contrast, other stress responses may be influenced more immediately by geomagnetic disturbances, as evidenced by reports of changes to CV parameters on the day of GMS [,], rather than such effects being purely downstream of melatonin disturbances (e.g. the day after the GMS). However, complex feedback between neuroendocrine systems [] could, for example, compound impacts on the CV systems, involving both immediate and melatonin-mediated interactions (e.g. see discussion in Gmitrov & Gmitrova []).
4. Summary of evidence and future evaluation
A role for cryptochrome in transmitting changes in the GMF to the circadian system is supported by several of the key correlates used to infer the role of cryptochrome in avian geomagnetic navigation. However, the evidence relies on only a handful of key papers, findings will require replicating and extending, issues need to be considered such as the role of multiple genes (CRY1 and CRY2), and other potential candidates, especially given the apparent presence of multiple receptors in other species []. Moreover, the hypothesis suggests the use of specific controls for cryptochrome (e.g. the use of specific wavelengths of light and oscillating magnetic fields in the low radio-frequency range) and more sophisticated experimental design (e.g. the use of shielded magnetic fields and simulated magnetic fields with specific emphasis on inclination, strength and possible temporal windows effects.) In contrast to the evidence for cryptochrome, the theoretical framework of magnetosense–HPA interactions is speculative and currently unsupported by experimental evidence. However, the existing behavioural paradigm—a secondary zeitgeber—is of questionable biological utility and contradicts experimental data. In contrast, the proposed alternative is consistent with existing notions of life-history theory and of the interactions between navigational or sensory behaviour and hormonal responses.
5. Discussion and consequences of the hypothesis
The extensive literature relating geomagnetic and solar activity to humans is often considered inexplicable and bizarre, including correlations with crime [], stock market returns [17], religious experience [] and revolutions [20]. Detractors of such literature have reasonable grounds for objection—lacking a rational explanation, such findings are merely spurious associations, likely to be the result of some unexpected confounder. However, there is now evidence for a specific biophysical pathway for these findings, with existing direct and indirect experimental evidence that cryptochrome is influencing circadian behaviour in response to magnetic stimuli. A fundamental question relates to whether cryptochrome could be orientating the circadian and related hormonal system in space or time, or perhaps even a complex interaction of both. Either way, the contentious and controversial associations in the literature are—by some degree—more plausible when placed upon a reasonable biological narrative. Despite the far-fetched nature of some of the behavioural and socio-political associations, they do paint a picture that is coherent when viewed through the framework of a population-level disruption of circadian rhythms and the subsequent lost sleep and anxious, stressful days.
Finally, the implications for human health are noted for a wide variety of disorders associated with geomagnetic activity including CV disease and psychiatric disorders. Further investigations could suggest the use of novel therapeutic interventions for diseases exacerbated by GMS. In Russia—where the effect of GMS have gained much more widespread institutional acceptance [18„]—a study has already trialled melatonin therapy to prevent the effects of GMS on CV patients, with positive results []. However, animal experimental evidence has suggested that the effects of magnetic activity on the circadian system are light-dependent. Could a simpler measure—the widespread use of sleep masks—shield at-risk patients from the negative effects of geomagnetic storms?
Acknowledgements
The author would like to gratefully thank the following people for their careful consideration and constructive criticisms with the manuscript: Prof. Tim Crow, Dr Helen Lloyd, Dr Joanne Lloyd, Dr Kate Lester and the referees.