Alerta de Google: criptocromos

Alerta de Blogs de Google para: criptocromos

NUEVO ESTUDIO, PUBLICADO EN NATURE, SOBRE EL EFECTO DE LAS ... según ANTENAS-PELIGRO-MOVIL Los criptocromos son pigmentos fotorreceptores que se encuentran al parecer en el núcleo de las células de las personas, animales, plantas y algunos microorganismos, con multitud de funciones. Éstos son esenciales en la orientación a ... ANTENAS-PELIGRO-MOVIL - http://antenas-peligro-movil.espacioblog.com/post/2009/12/03/manifestacion-nantes-contra-contaminacion-electromagnetica

---

 Google le ofrece esta alerta de Google una vez al día..

Eliminar esta alerta.
Crear otra alerta.
Administrar sus alertas.

Los científicos descubren una molécula tras el sentido magnético de las aves

fotografía señoras viñedos camino del cid franquicia ahorros creditos

Algunas aves, principalmente las especies migratorias, son capaces de detectar el campo magnético de la Tierra y de utilizarlo para guiarse. Los nuevos resultados de un equipo de investigadores franco-alemanes sugieren que unas moléculas fotorreceptoras llamadas criptocromos podrían ser la clave del sentido magnético de las aves.

Los criptocromos son fotorreceptores sensibles a la luz azul y participan en varios procesos vinculados al ritmo circadiano, como el crecimiento y el desarrollo.

La capacidad de las aves para detectar campos magnéticos está influenciada por la luz; este "sexto sentido" sólo funciona adecuadamente en presencia de luz azul o verde, mientras que la luz de otras longitudes de onda altera el sentido magnético.

Los científicos se dieron cuenta de que los criptocromos podrían estar involucrados en la percepción del campo magnético, ya que poseían todas las propiedades físicas y químicas necesarias para ello, particularmente la absorción de luz azul y verde y la formación de "pares radicales", moléculas que responden a los campos magnéticos. Lo verdaderamente crucial es que la retina de los ojos de las aves es rica en criptocromos.



Incapaces de probar su hipótesis sobre las aves migratorias, los investigadores recurrieron a una planta de laboratorio con propiedades similares, la Arabidopsis thaliana. Es sabido que la activación de sus criptocromos por la luz azul influye en el comportamiento de estas plantas; por ejemplo, inhibe el crecimiento del hipocótilo (tallo).

Para determinar si el campo magnético influye en la función de los criptocromos, investigadores del Centro nacional de investigación de Francia (CNRS) y universidades de Frankfurt y Marburgo cultivaron las plantas en presencia de luz azul y roja y de campos magnéticos de varias intensidades. Descubrieron que aumentar el campo magnético sólo aumenta la inhibición del crecimiento del hipocótilo en presencia de la luz azul. Cuando se utiliza la luz roja la planta utiliza otros fotorreceptores llamados fitocromos y el crecimiento del hipocótilo no se ve afectado por los cambios en el campo magnético. Además, las plantas mutantes que no tienen criptocromos también son insensibles a los cambios en el campo magnético.

El estudio demuestra por primera vez que en las plantas, la función de los criptocromos se ve afectada por los campos magnéticos, y sugiere que los mecanismos de percepción del campo magnético en las plantas, y por extensión en las aves migratorias, se sirven de las mismas moléculas fotosensibles. Los investigadores también sugieren que, puesto que los criptocromos han sido conservados en gran medida a lo largo de la evolución, todos los organismos biológicos podrían tener la capacidad de detectar campos

Resonance effects indicate a radical-pair mechanism for avian magnetic compass
Thorsten Ritz1, Peter Thalau2, John B. Phillips3, Roswitha Wiltschko2 & Wolfgang Wiltschko2
Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA
Zoologisches Institut, Fachbereich Biologie und Informatik, J.W. Goethe-Universität, Siesmayerstrasse 70, D-60054 Frankfurt am Main, Germany
Department of Biology, 2119 Derring Hall, Virginia Tech, Blacksburg, Virginia 24061, USA
Correspondence to: Thorsten Ritz1 Correspondence and requests for materials should be addressed to T.R. (Email: tritz@uci.edu).
Top of page
Abstract
Migratory birds are known to use the geomagnetic field as a source of compass information1, 2. There are two competing hypotheses for the primary process underlying the avian magnetic compass, one involving magnetite3, 4, 5, the other a magnetically sensitive chemical reaction6, 7, 8. Here we show that oscillating magnetic fields disrupt the magnetic orientation behaviour of migratory birds. Robins were disoriented when exposed to a vertically aligned broadband (0.1–10 MHz) or a single-frequency (7-MHz) field in addition to the geomagnetic field. Moreover, in the 7-MHz oscillating field, this effect depended on the angle between the oscillating and the geomagnetic fields. The birds exhibited seasonally appropriate migratory orientation when the oscillating field was parallel to the geomagnetic field, but were disoriented when it was presented at a 24° or 48° angle. These results are consistent with a resonance effect on singlet–triplet transitions and suggest a magnetic compass based on a radical-pair mechanism7, 8.
To read this story in full you

Antenas y declive de los gorriones

Antenas y declive de los gorriones

(Fuente e imagen: El País)

Según la noticia aparecida el pasado sábado, anualmente la población de gorriones comunes ha descendido en 400.000 ejemplares sólo en Madrid, Valencia y Castilla y León. En Barcelona cifran que en unos 20 años, la población de gorriones comunes puede quedarse en la mitad. En 2007 estimaron una población de gorriones comunes a nivel estatal de cerca de 163 millones de ejemplares.

En Europa, estas aves no corren mejor suerte: en Londres, esta especie (Passer domesticus) está a punto de pasar a ser especie en peligro de extinción, ya que desde 1970 ha perdido el 71% de su población.

Entre las principales causas de tal descenso, los expertos apuntan a la excesiva limpieza de las calles o la presencia de otras aves más agresivas (como las palomas). Sin embargo, además de otros factores ambientales, Juan Carlos del Moral, del Área de Estudio y Seguimiento de Aves de SEO/BirdLife, advierte que «los nidos de cualquier especie situados cerca de antenas de telefonía móvil dan unos índices escandalosamente bajos de productividad».

Esta afirmación está en la línea de lo que ya comentó en la Aniruddha Mukherjee, director del departamento de ciencias ambientales en la Universidad de Calcuta (India) hace casi dos años: «la población de pájaros como los gorriones y las palomas se ha visto afectada por las ondas electromagnéticas de las estaciones base de telefonía móvil». O la que realizó en el 2003 el Dr. Vijayan, Director del Salim Ali Centre for Ornithology and Natural History (SACON), «se han realizado varios estudios para encontrar si existía una relación entre el incremento de ondas electromagnéticas y el descenso en la población de gorriones. Una correlación positiva se ha encontrado entre ambos».

Todo ello sin olvidar los estudios realizados por el biólogo de fauna silvestre Alfonso Balmori, de Valladolid, España informa que: "La radiación electromagnética es una forma de contaminación ambiental que puede dañar la fauna silvestre. Las antenas de telefonía móvil ubicadas en las áreas donde viven, están irradiando continuamente a algunas especies que podrían sufrir efectos a largo plazo, como la disminución de sus defensas naturales, deterioro de su salud, problemas de reproducción y reducción de su territorio útil por deterioro del hábitat. Por lo tanto, la contaminación de microondas y radiofrecuencia constituye una causa potencial para la disminución de las poblaciones de animales y el deterioro de la salud de las plantas que viven cerca de las antenas de telefonía."

Electromagnetic Radiation: Influences on Honeybees (Apis mellifera)
Kimmel, Stefan1*; Kuhn, Jochen2; Harst, Wolfgang3; Stever, Hermann3
1 Institute for Environmental Sciences, University of Koblenz-Landau/Campus Landau, Germany
2 Institute of Science and Science Education (ISSE), Department of Physics, University of Koblenz-Landau/Campus Landau, Germany
3 Institute of Educational Informatics, University of Koblenz-Landau/Campus Landau, Germany
* Author for correspondence (e-mail: kimmel@uni-landau.de)
ABSTRACT
Focussing on the influences of non-ionizing radiation towards the behaviour of the honeybee (Apis mellifera), the here presented study reports partially significant results. Nowadays, there is a certain increase of radiation impact in today’s environmental ecosystems, and the influence of higher frequencies on honey bees is analyzed by the workgroup "educational informatics" since 2001 (Stever & Kuhn 2001; Kuhn & Stever 2001; Kuhn & Stever 2002). In ecotoxicology, the honeybee (Apis mellifera) is of great importance as a tested species for agricultural chemicals, e. g. plant protection products and pesticides. In this case, significant variations in the behaviour of Apis mellifera under the influence of non-ionizing radiation were tested. The presented data set is based on earlier studies from 2005, which showed significant differences in returning, 39.7% of the non-irradiated bees came back compared to 7.3% of the irradiated ones.
Standard commercial DECT telephones were used as exposition source. Concerning possible variations in behaviour an experimental setup with irradiated and non-irradiated bee hives was assembled. The main emphasis of this study was the investigation on significant changes in the foraging flight under electromagnetic radiation influence.
Keywords: Honeybees, electromagnetic radiation, learning process, changing behaviour, ecotoxicology.
1. INTRODUCTION
This study focuses on the effects of an electromagnetic exposition caused by DECT Telephones on the behaviour of the honeybee. All researches and tests have been carried out at the Dienstleistungszentrum Ländlicher Raum (DLR), Fachzentrum Bienen und Imkerei, in Mayen during June/July 2006. There have been several scientific investigations throughout the past years concerning the electromagnetic radiation and its effects (Greenberg et al., 1981; Hartsgrove et al., 1987; Eulitz et al., 1998; Rothmana, 2000). In context of the increasing non-ionising radiation, this study focus on the effects of electromagnetic exposition on the behaviour of the honeybee. Especially towards crop pesticide testing, Apis mellifera is a confirmed test species in ecotoxicological researches. Furthermore the honeybee shows an effective learning behaviour, resulting in olfactory amenities and even forms, structures and faces and also in training abilities on certain plants (Vareschi & Kaissling, 1970; Hoefer & Lindauer, 1976; Dyer et al 2005). Apis mellifera is well suited as a bioindicator, because its brain anatomy as well as the learning regions of the bee brain are well known (Menzel & Müller, 1996; Zhang et al., 1999; Schwärzel & Müller, 2006) and the brain structure of the honeybee concerning associative learning is comparable to those of vertebrates (Bliss & Collinridge, 1993; Eichenbaum, 2004; Giurfa, 2003; Schwärzel &
-1-
Müller, 2006). Concerning the effects of electromagnetic radiation it might be possible to draw conclusions towards other organisms based on the results according to the monitoring of honeybees.
2. MATERIAL AND METHODS
2.1 Physical aspects
In this case, base stations of everyday used DECT telephones (Digital Enhanced Cordless Telecommunications) were fixed as radiation sources. Investigating on non-thermal influences of electromagnetic fields towards the learning behaviour of bees requires an exposition with an appropriate radiation frequency. The stations send out continually electromagnetic radiation with a frequency fS ≈ 1900 MHz and an average transmitting power PS of 10 mW. The peak power is 250 mW and the sending signal throughout a talk is frequency modulated and pulsed with a frequency fp of 100 Hz. For this study the base station is used as radiation source at a permanent standby mode reached with an average transmitting power of PS = 2.5 mW. To analyze a possible effect of the radiation intensity, cubic radiation shields made of reed and clay were build around some of the DECT base stations (experimental group 2, EG2, refer to 2.2), which is completely permeable to the low-frequency pulse mentioned above, but enables a reduction of the high-frequency sending radiation about 50% (Moldan & Pauli, 2000). We also installed metal lattices (width 1x1 mm) between the exposed bee hives (experimental group) in order to avoid possible influences of the radiation on the non-exposed bee hives (control group, CG).
The stations were put at the bottom of a beehive, right under the honeycombs (Fig. 1).
Fig. 1: Position of DECT base station within a bee hive
2.2 test objects and method
Overall, 16 Bee colonies of Apis mellifera carnica were used as test objects. With a permanent connection establishment between the wireless cells and the DECT base stations, the average sending power Ps could be estimated. Five of eight exposed hives were under fully electromagnetic exposure (experimental group EG 1), while in three of the exposed colonies the radiation was shielded down to 50% (experimental group EG 2, see Fig. 1). The following figure shows the whole experimental set-up: Wooden frames with bee cells DECT-base stationBee hive Cubic radiation shield of reed around the DECT base
-2-
Fig. 2: Experimental set up
For one test run, 15 bees flying out of the hive were trapped with the help of plastic tubes at the hive entrance. All catched bees were short term paralyzed (using CO2) and got marked with a marker dot on the thorax. At a distance of about 500 m to the hive all marked bees were set free simultaneously and got timed from that moment. Concerning the returning behaviour, in every test run irradiated bees were checked against non-exposed ones (EG 1 vs. CG; EG 1 vs. EG 2; EG 2 vs. CG). Time of flight for every single bee as well as certain aspects like weather, temperature and hive activity in common was reported. The returning bees were intercepted at the bee hive's entrance and the returning time was documented. The observation time lasted 45 minutes, bees that came back afterwards were disregarded in order to avoid possible mistakes for following test runs.
3. RESULTS
All results are based on collected data from June, 28.–29., and July, 9.-19., in 2006.
3.1 statistics
52 paired comparisons had to be taken into consideration, 31 pairs of bee colonies "EG 1 vs. CG", 15 pairs "EG 2 vs. CG" and finally 6 pairs "EG 1 vs. EG 2". In 22 of the 31 tested pairs "EG 1 vs. CG" more of the non-exposed bees (CG) returned to their colonies. With the total amount of returned bees (non-exposed 293 = 63.0%, exposed 229 = 49.2%) the tendency of earlier researches (Stever et al., 2005) could be confirmed.
Overall, 482 (63%) bees of the CG, 203 (56.4%) bees of the EG 2 and 365 (54.1%) bees of the EG 1 returned to their hive. These differences between the groups were not significant (Kruskal-Wallis H test).
One of the main problems of the statistical analysis was to combine the amount of returning bees with their returning time in one single value (tnr), which reflects the predominate circumstances and enables a comparison between different testing properties. The following term presents a possible solution to this problem:
tnR = nR * 46 – Σ tR
In this term the amount of returning bees nR is multiplied by the maximum observation time + 1, then the sum of the returning time of each bee tR, which were actually returned, is subtracted from this product. To standardize the tnR-Index its term is related to the maximum value (for this study (nRmax = 15 bees * [45min + 1]), the tnmax is up to 690):
tn = tnR * 100 / tnmax
EG 2
EG 1
Metal lattice
South/east
North/west
-3-
fully exposed
It became obvious that in 29 of 31 tested pairs the tn-index was higher for non-exposed bees, with tn-index-mean ratio of 48.97 (SD 20.74) for non-exposed bees against a tn-index-mean ratio of 38.48 (SD 16.41) for exposed bees.
The comparison in pairs between bees of the EG 1 with bees of the CG is presented in Fig. 3:
Fig. 3: tn-Index comparison CG (green) vs. EG 1 (red), decreasing ranks
3.2 tn-index mean comparisons for all tested groups
All deviations concerning the mean ratio for each compared group are tested for significant differences by conducting the t-test for independent variables.
Referring to the results of the t-test, mean differences between non-exposed and exposed honeybees (CG vs. EG 1) were significant (p = 0.031), whereas the other two tested pairs (CG vs. EG 2; EG 1 vs. EG 2) showed no significant differences.
Furthermore no correlations of uncontrollable factors like weather, temperature and flight frequency with the tn-Index were found, which shows that there is no influence of these uncontrollable factors concerning our results.
4. DISCUSSION
Obviously certain factors concerning the experimental set up are hard to control, but aspects such as homogenous bee colonies, the location of the tested hives and the interaction between studied bee colonies and disregarded neighbour colonies must be observed and controlled before starting a following study. Also the testing place should be selected as soon as possible, in order to allow the bees selecting a preferred region for collecting food.
The results of this study are much more heterogenic compared to our examination in 2005. But despite this aspect, still a significant difference between exposed and non-exposed bee colonies could be observed. A correlation between the independent factors weather, flight frequency and temperature on the tn-index could not be determined. A possible influence of the radiation intensity could not be proven by this study, because no significant differences between the group-pairs CG and EG 2 as well as EG 2 and EG 1 could be detected. Also, a clear distinction between the low-frequency pulse of the DECT base station and its high-frequency sending radiation could not be drawn, despite the fact that a significant difference between the non-exposed bees and the fully tn-Indexnon-exposed -
-4-
irradiated ones can be counted as a result of the influence of high-frequency electromagnetic radiation.
A certain method to improve the experimental set up can be found in automating the testing intervals, e.g. by using a lock at the hive entrance for automatically collecting the bees. Finally, it would be also very important to measure the exact radiation intensity within the hives as well as the concrete character of the used radiation.
5. LITERATURE
Bliss, T. V. P. & Collingridge, G. L. (1993); A synaptic model of memory: long-term potentiation in the hippocampus. Nature, Vol. 361 (pp. 31-39).
Dyer, A. G., Neumeyer, C. and Chittka, L. (2005); Honeybee (Apis mellifera) vision can discriminate between and recognise images of human faces. Journal of Experimental Biology, Vol. 208 (pp. 4709-4714).
Eichenbaum, H. (2004); Hippocampus: cognitive processes and neural representations that underlie declarative memory. Neuron, Vol. 44 (pp. 109-120).
Eulitz, C., Ullsperger, P., Freude, G. & Elbert, T. (1998); Mobile phones modulate response patterns of human brain activity. Neuroreport, Vol. 9, No. 14 (pp. 3229-3232).
Giurfa, M. (2003); The amazing mini-brain: lessons from a honey bee. Bee World, Vol. 84, No. 1 (pp. 5-18)
Greenberg, B., Bindokas, V. P. & Gauger, J.R. (1981); Biological effects of a 765-kV transmission line: exposures and thresholds in honeybee colonies. Bioelectromagnetics, Vol. 2, No. 4 (pp. 315-328).
Hartsgrove, G., Kraszewski, A. & Surowiec, A. (1987); Simulated biological materials for electromagnetic radiation absorption studies. Bioelectromagnetics, Vol. 8, No. 1 (pp. 29-36).
Hoefer, I. & Lindauer, M. (1976). Der Einfluss einer Vordressur auf das Lernverhalten der Honigbiene. Journal of Comparative Physiology, Vol.109 (pp. 249-264).
Kimmel, S., Kuhn, J., Harst, W. & Stever, H. (2007): Effects of Electromagnetic Exposition on the Behaviour of the Honey Bee (Apis mellifera). ACTA SYSTEMICA - IAAS International Journal; in press
Kuhn, J. & Stever, H. (2001); Handy-Boom: eine Gefahr für die Imkerei? ADIZ 35/die Biene 137/Imkerfreund 56, Heft 2, S. 12-13
Kuhn, J. & Stever, H. (2002); Einwirkung hochfrequenter elektromagentischer Felder auf Bienenvölker. Deutsches Bienenjournal, 10, Heft 4, S. 151-154
Locatelli, F., Bundrock, G. & Müller, U. (2005 ); Focal and Temporal Release of Glutamate in the Mushroom Bodies Improves Olfactory Memory in Apis mellifera. The Journal of Neuroscience, Vol. 25, No. 50 (pp. 11614-11618).
Menzel R. & Müller, U. (1996); Learning and memory in honeybees: from behaviour to neural substrates. Annual Review of Neuroscience, Vol. 19 (pp. 379-404).
Moldan, D. & Pauli, P. (2000); Reduzierung hochfrequenter Strahlung im Bauwesen: Baustoffe und Abschirmmaterialien. Iphofen: Eigenverlag.
Rothmana, K. J. (2000); Epidemiological evidence on health risks of cellular telephones. The Lancet, Vol. 356, No. 9244 (pp. 1837-1840).
Schmickl, T. (2003). Sammeln, Verteilen und Bewerten von Informationen: Verteilte Intelligenz in einem Bienenvolk. Wien: Böhlau Verlag.
Schwärzel, M. & Müller, U. (2006); Dynamic memory networks: dissecting molecular mechanisms underlying associative memory in the temporal domain. Cell. Mol. Life Sci., Vol. 63 (pp. 989-998).
-5-
Stever, H. & Kuhn, J. (2001): Schutz der Bienen vor Handy-Strahlung. Schweizerische Bienen-Zeitung 124,Heft 9, S. 23-27
Stever, H., Kuhn, J., Otten, C. Wunder, B. & Harst, W. (2005); Verhaltensänderung unter elektromagnetischer Exposition. Landau: Arbeitsgruppe Bildungsinformatik (http://agbi.uni-landau.de/materialien.htm)
Tautz, J. (1996); Honeybee waggle dance: Recruitment success depends on the dance floor. The Journal of Experimental Biology, Vol. 199 (pp. 1375-1381).
Vareschi, E. & Kaissling, K.-E. (1970). Dressur von Bienenarbeiterinnen und Drohnen auf Pheromone und andere Duftstoffe. Zeitschrift vergl. Physiologie, Vol. 66 (pp. 22-26).
Zhang, S. W., Lehrer, M. & Srinivasan, M. V. (1999); Honeybee Memory: Navigation by Associative Grouping and Recall of Visual Stimuli. Neurobiology of Learning and Memory, Vol. 72 (pp. 180-201).
-6-

Why Vodaphone should not increase the power of its base stations

ITNT Archive: Disappearing Bees
This is an emailed response to Cliff Mason of OFCOM following a proposal by Vodafone that it should be allowed to increase the power of its base stations by a factor of four. The email explains the mechanism by which base station radiation may be responsible for the increased incidence of cancer around them, the decline of the bees, and the loss of many trees within range to pathogens. It also explains how a simple modification to the signal could put it right.
It remains to be seen whether they are prepared to do anything about it.
Dear Cliff Mason,
As an ex-amateur radio enthusiast, I am a great believer in the value of mobile communications, but things are not yet right. There is compelling evidence for a mechanism by which the continuous radiation from mobile phone base stations can weaken the immune systems, not only in humans, but also in animals and plants. In addition, the same mechanism is probably responsible for colony collapse disorder in honey bees and their increased susceptibility to various pathogens.
It is based on a family of pigments called cryptochromes, which occur in virtually all animals and plants and some micro-organisms. They have a number of functions, including navigation in the Earth’s magnetic field and the regulation of the “body clock”, which is needed for solar navigation and also for the regulation of the immune system. This pigment is very badly affected by a wide range of radio frequencies, so that all of these processes can be disrupted by the modulated radiation from mobile phone base stations. This can explain the clusters of cancer cases believed by many people to have formed around mobile phone base stations as well as the decline and incipient loss of the honey bee population, which will have far more serious consequences for mankind. Insofar as the mobile phone operators say that there is no known mechanism by which their radiation can have these effects, we can only assume that they are unaware of its effects on cryptochrome.
I am attaching a document entitled “Making Mobile Phones Safer”, which sets this out in more detail and makes some simple suggestions to mitigate these effects. I am also attaching the original “Nature” paper by Ritz et al. in which they first discovered the effects of radio-frequency radiation on cryptochrome and animal navigation.
I am quite happy for you to forward this email, with attachments, to Vodafone, but I would suggest that they postpone any increase in power until this has been sorted out. It may not be that difficult.
Making Mobile Phones Safer
Mobile phone radiation can be linked to colony collapse disorder and immune dysfunction
Bee colonies are dying mysteriously all over the developed world. Often their navigation systems fail and they do not return to the hive after collecting pollen and nectar, which can cause colony collapse disorder. Their immune systems also fail and they become unusually susceptible to pathogens to which they might otherwise be resistant. Both of these effects can now be linked by plausible mechanisms to the electromagnetic radiation from mobile telecommunications.
Why the bees are important.
If the decline of the bees continues, the effects on agriculture will be devastating and even the continued existence of the human race will be called into question. Many of our crops depend on bee pollination, and the remainder cannot provide a balanced diet. While the bulk of our staple foods come from wind-pollinated cereals that do not rely directly on the bees, these do not support the nitrogen-fixing bacteria needed for sustainable agriculture. Without bee pollinated crops (e.g. legumes) that host these bacteria, we will have to rely on artificial nitrogen fertilisers, which are either mined from limited natural sources or manufactured from the nitrogen of the air. Both are heavily dependent on fossil fuels and are not sustainable. Without them even our wind-pollinated crops will be decimated, which will lead to famine and mass starvation.
In addition, cereals do not provide an adequate balanced diet. In particular, they are almost totally lacking in vitamin C, which is essential to prevent scurvy. Scurvy is a fatal disease in which the body is unable to make the collagen needed for the connective tissue that binds our tissues and organs together. Without it, we literally begin to fall apart. The teeth fall out, the joints deteriorate and it leads to a slow and very painful death. Bee-pollinated crops are the main natural sources of vitamin C. Although some vitamin C producing species can self-pollinate or be propagated vegetatively, these are of necessity inbred and lack genetic diversity. Consequently, they will be less able to adapt to changing environmental conditions, including climate change and newly-evolved pathogens. They cannot be expected to last us for long.
Electromagnetic radiation is the most likely cause of bee loss
Whatever is causing the decline in the bee population in developed countries, it is likely to be man-made. Various possibilities have been mooted, including the varroa mite, pesticides and other agrichemicals, but the front runner, for which there is the most convincing evidence, is the radio-frequency radiation from mobile telecommunications. For example, German scientists placed cordless phone base stations (which emit modulated microwave radiation 24/7 just like mobile phone masts) next to some of their hives, but left others unexposed to the radiation. They then marked the bees as they left the hives and counted the proportion of the marked bees that returned. They found that a significantly larger proportion did not return in the hives that had been irradiated (more details at (http://tinyurl.com/rans84 ). But what could be the mechanism of this odd behaviour? It looks very much as if it is due to the effects on their cryptochromepigments, which they use for both solar and magnetic navigation, and is highly sensitive to radio frequency radiation.
The Cryptochromes
The cryptochromes are a family of pigments found in virtually all animals and plants. The earliest forms (which we now call photolyase) absorb light and use its energy to repair damaged DNA. More recently evolved cryptochromes actually measure light and tell the organism whether it is night or day so that it can adapt its metabolism accordingly. Still later versions became an integral part of the “body clock”, now present in virtually all animal and plant cells, which regulates the timing of their natural circadian rhythms. These rhythms regulate, amongst other things, our sleep-wake cycle and our resistance to disease. Normally, they are synchronised with day and night by environmental cues such as changes in light and temperature, but they can also run indefinitely under constant conditions (although they may not then be exactly 24 hours). They affect many aspects of metabolism and allow cells and organisms to anticipate the coming of dawn and dusk so that they can prepare themselves in advance for the new conditions. They are extremely important for all of us; if they get out of kilter with the natural day-night sequence, such as when flying to a different time zone, we get jet lag and feel distinctly out of sorts until the rhythm become synchronised again.
Cryptochromes are used for animal navigation
Animals that use the sun for navigation have extremely accurate cryptochrome-based body clocks that enable them to compensate for its changing position throughout the day. Animals that navigate using the earth’s magnetic field also use cryptochromes to sense the direction of the field. Cryptochrome can detect the direction of the field because it uses the energy of light to flip an electron between two parts of the molecule to generate a pair of unstable magnetic free radicals. The electron tries to return to its original position, but the rate at which it does so depends on the direction of the earth’s field relative to the molecule, and gives an indication of the direction of the field. This sort of cryptochrome occurs in the eye and enables the animal to superimpose the direction of the magnetic field on its visual field as a “heads-up” display, which is ideal for navigation.
Electromagnetic fields disrupt cryptochrome-based magnetic navigation.
Thorsten Ritz and his co-workers (Nature, Vol. 429, pp177-180, 13th May 2004) showed that even weak electromagnetic radiation over a wide range of radio frequencies completely prevented robins orienting for navigation in a steady magnetic field simulating that of the Earth; the same is probably true for bees. The mechanism has since been confirmed and further elucidated by other workers. Although the active frequencies are lower than the nominal carrier frequencies used by mobile phones, they can be generated when they are modulated to carry information such as speech. Very little radio-frequency energy is needed since the energy to drive the process comes in this case from a high energy photon of light, which is stored in the free radical form of the molecule. The RF simply just modulates the thermodynamically downhill reaction that restores the status quo with a net release of energy. This allows non-ionizing radio frequency radiation, with photon energies far below that necessary to break chemical bonds, to give biological effects, which in this case disrupts magnetic navigation.
Solar navigation can also be affected.
The cryptochrome-based body clock in insects is also affected by magnetic fields, as was shown by Yoshii and coworkers in 2009 (more details athttp://tinyurl.com/y9vkzfj ); it is therefore likely that the bee’s ability to navigate by the sun is also compromised.
The radiation from mobile phone masts and similar wireless devices can therefore disrupt bee navigation, both by the sun and by the earth’s magnetic field. This can reduce the number of foraging bees returning to the hive and result in colony collapse disorder.
Effects on the immune system
Virtually all animal immune systems are under the control of their circadian rhythms. This is to make the best use of limited bodily resources, which are diverted from physical activity during the day to the immune system and the repair of damage at night. If these rhythms are disrupted, or their amplitude reduced by electromagnetic radiation, nothing they control can ever function at full power. Consequently, bees affected in this way may die, seemingly of other causes, including attack by pathogens to which they might otherwise be resistant. More information on circadian rhythms and their close links to the immune system can be found in Willard L. Koukkari and Robert B. Sothern. “Introducing Biological Rhythms”, pp 426 – 525. Springer 2006. ISBN 13: 078-1-4020-3691-0.
Effects on plants
The cryptochromes are one of several families of light-sensing pigments used by plants to control their patterns of growth and physiology so that they can make the best use of light for photosynthesis. For example, cryptochrome brings about the night time closure of stomata. Stomata are microscopic pores in the surface of leaves and stems used for photosynthetic gas exchange. They open during the day to absorb carbon dioxide for photosynthesis and close at night to prevent the unnecessary loss of water vapour. Cryptochrome is also one of the pigments used to measure the length of the day to control photoperiodic responses; e.g. the “deliberate” shedding of leaves by deciduous trees in autumn is a response to short days.
There is mounting anecdotal evidence that radiation from mobile phone base stations disturbs these functions. I would like to invite you to see this for yourself. There is a very powerful Vodafone mast just outside the northeast corner of Hanger Hill Park, London W5, which appears to have damaged many of the nearby trees inside the park. Those in the main beam within a radius of about 400metres often show growth abnormalities with the younger shoots dieing. Many trees have actually died completely in the ten years or so that the mast has been operational. Most of them have now been removed, but there is still evidence of damage in those that remain. The cause of death also seems to be related to cryptochrome. Many of the mortalities occurred in dry conditions, possibly because the radiation kept the stomata open at night when they should have been closed. Another abnormality still visible in several trees is their partial or complete failure to shed their leaves and seeds in autumn; they remain dead on the tree but still firmly attached. It is as if the radiation absorbed by cryptochrome is perceived as light so that the tree behaves as if it was in continuous light and cannot respond to short days. This type of behaviour appears to have increased considerably since the power of the mast was increased to accommodate 3G.
A further effect of the radiation seems to be on the functioning of the plant equivalent of the immune system, which leads to attack by pathogens to which they would normally be resistant. This may explain the mysterious increase in general tree mortality from disease, especially bacterial diseases, in recent years. As in animals, cryptochrome plays a vital role in the regulation of the plant immune system. For example; recent work by Wu and Yang (Molecular Plant Advance Access Jan 6 2010, doi:10.1093/mp/ssp107) showed that Arabidopsismutants lacking a functional cryptochrome 1 had a lowered resistance to the bacterial pathogen Pseudomonas syringae, whereas similar plants in which the gene was over-expressed had enhanced resistance. If radio-frequency electromagnetic radiation were to compromise the normal functioning of cryptochrome, we might expect that this would reduce the plant’s resistance to disease.
Effects on humans
Although humans have no natural ability for magnetic or solar navigation, we still use cryptochromes to control our circadian rhythms and immune systems. There are now increasing reports of cancer clusters around mobile phone masts that can be attributed to a failure of the immune system to dispose of incipient cancer cells. This is the most likely explanation since other factors that disturb our circadian rhythms, such as shift-working and exposure to continuous illumination, have similar effects on health. These include significant increases in the incidence of breast cancer, colorectal cancer and heart disorders (http://tinyurl.com/afgLjr ). Similar increases are to be expected in people living close to mobile phone masts. Many of them already report poor sleep at night and tiredness during the day, which suggests that their natural circadian rhythms have been disturbed. Present evidence suggests that the radiation is perceived as light, which disrupts the dark phase of the cycle, during which the immune system should be most active. If so, humans who might normally tolerate the radiation during the day will be less able to do so at night. Every effort should therefore be made to avoid night time or continuous exposure to the radiation from base stations.
What can be done about it?
1. Postpone any increase in power. When you are in a hole, stop digging. The first thing to do is to suspend any increase in the power of mobile phone base stations until this problem has been solved.
2. Use Femtocells. This technology uses low power domestic base stations connected to the broadband network by a wired or optical links. It is already the preferred option for the mobile phone operators (seehttp://www.ipaccess.com/femtocells/consumer_value.php ) since it is cheaper, more reliable, and the consumer bears most of the cost. It also reduces the need for investment in high power base stations and reduces the traffic through each. If Femtocells lead to the bulk of the traffic being routed though these very low power base stations, which are partially shielded by the walls of the house, less will be routed through the major base stations and the effects on the bees and other wildlife should be minimised.
However, there are some very important provisos. The Femtocells should be no more powerful than is necessary to cover a single household and shouldautomatically cease transmission when not in use (rather like an Orchid Low Radiation DECT Phone Base Station). This is not just to save electricity but also to minimise disruption of the circadian rhythms and immune systems of the users, their neighbours and wildlife. The fact that most of the Femtocells would then be inactive at night when the immune system would otherwise be most active is particularly important.
3. Restrict the bandwidth of the signal
A problem with digital signals is that their rapid rise and fall times generate a very large number of harmonics (multiples of the basic frequency). When these are used to modulate carrier waves, they generate very wide sidebands on either side of the carrier frequency, which actually carry the information. The width of each sideband corresponds to the frequency of the highest harmonic of the signal to be transmitted and is likely to overlap with the frequencies to which cryptochrome is sensitive. This “out-of-band” radiation does not normally interfere with other radio transmissions because it is relatively weak at any given frequency. However, cryptochrome is sensitive over a very wide range of frequencies and the signal is integrated over this range so that interference may be severe. A simple solution that should be investigated is to suppress the part of the lower sideband, which overlaps with the cryptochrome range. (This is already done with analogue television, which uses vestigial sideband transmissions). The upper base station sideband, and what remains of the lower one, will still contain all the digital information but should be relatively safe.
Other Modifications
While interference with cryptochrome is probably not the only way in which modulated radio waves from base stations give rise to biological effects, it is likely to be the one that has the most effect on the bees and also the immune systems and consequent risk of cancer in human beings. Other non-thermal biological effects of mobile phone radiation, such as DNA damage, have a different aetiology, but provided the immune system is fully functional, most of the damaged cells may be eradicated before they become cancerous.
Nevertheless, it may be possible to do something about this too. DNA damage is most likely due to the release of structurally-important calcium ions from cell membranes by modulated radio waves, first noted by Bawin et al. in 1975 (Effects of modulated VHF fields on the central nervous system. Ann NY Acad Sci 247: 74-81). There is strong evidence that this weakens the membranes and makes them more inclined to leak (A Goldsworthy in “Plant Electrophysiology: Theory and Methods” Ed AG Volkov. Springer 2006: ISBN-10 3-540-32717-7). When lysosomes leak, they release digestive enzymes, including DNase, into the main part of the cell to cause DNA fragmentation. Damage to the membranes of mitochondria will release free radicals that are normally used in the controlled oxidation of food products, but are kept locked up safely within the structure of the membrane. These free radicals can also damage DNA. However, it should be possible to modify the transmitted signal to avoid these effects on membranes too. This too may be easier than you think.
Andrew Goldsworthy BSc PhD
Lecturer in Biology (retired)
Imperial College London