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| 2. |
- Nittby, Henrietta, et al.
(författare)
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Exposure to radiation from global system for mobile communications at 1,800 MHz significantly changes gene expression in rat hippocampus and cortex
- 2008
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Ingår i: The Environmentalist. - : Springer Science and Business Media LLC. - 0251-1088 .- 1573-2991. ; 28:4, s. 458-465
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Tidskriftsartikel (refereegranskat)abstract
- We have earlier shown that radio frequency electromagnetic fields can cause significant leakage of albumin through the blood-brain barrier of exposed rats as compared to non-exposed rats, and also significant neuronal damage in rat brains several weeks after a 2 h exposure to a mobile phone, at 915 MHz with a global system for mobile communications (GSM) frequency modulation, at whole-body specific absorption rate values (SAR) of 200, 20, 2, and 0.2 mW/kg. We have now studied whether 6 h of exposure to the radiation from a GSM mobile test phone at 1,800 MHz (at a whole-body SAR-value of 13 mW/kg, corresponding to a brain SAR-value of 30 mW/kg) has an effect upon the gene expression pattern in rat brain cortex and hippocampus-areas where we have observed albumin leakage from capillaries into neurons and neuronal damage. Microarray analysis of 31,099 rat genes, including splicing variants, was performed in cortex and hippocampus of 8 Fischer 344 rats, 4 animals exposed to global system for mobile communications electromagnetic fields for 6 h in an anechoic chamber, one rat at a time, and 4 controls kept as long in the same anechoic chamber without exposure, also in this case one rat at a time. Gene ontology analysis (using the gene ontology categories biological processes, molecular functions, and cell components) of the differentially expressed genes of the exposed animals versus the control group revealed the following highly significant altered gene categories in both cortex and hippocampus: extracellular region, signal transducer activity, intrinsic to membrane, and integral to membrane. The fact that most of these categories are connected with membrane functions may have a relation to our earlier observation of albumin transport through brain capillaries.
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| 3. |
- Nittby, Henrietta, et al.
(författare)
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Nonthermal GSM RF and ELF EMF effects upon rat BBB permeability
- 2011
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Ingår i: The Environmentalist. - : Springer Science and Business Media LLC. - 0251-1088 .- 1573-2991. ; 31:2, s. 140-148
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Tidskriftsartikel (refereegranskat)abstract
- Since the late 1980s, our group has examined the effects of radiofrequency electromagnetic fields (RF-EMF), including pulse-modulated waves of the type emitted by mobile phones, upon the blood-brain barrier. In more than 2,000 rats, we have repeatedly demonstrated a passage of the rats' own albumin from the blood through the brain capillaries into the surrounding brain parenchyma at SAR values down to 0.1mW/kg. In most of these experiments, the animals were exposed in TEM-cells, ventilated by an external electrical fan at 50 Hz. In the present study, we examined whether the extremely low frequency (ELF) magnetic fields from the fan (50 Hz, 0.3-1.5 μT) might add to the RF effect. Sixty-four rats were divided into 4 groups: RF only, ELF only and RF + ELF exposure plus a sham group. The GSM-900 MHz RF exposure was at the very low, nonthermal, average whole-body SAR level 0.4 mW/kg. Demonstration of the normally occurring albumin extravasation in the basal hypothalamus is our inbuilt control proving that the staining is reliable. Two full series of staining of the whole material gave negative results for hypothalamus. Not until we changed to avidin, biotin, and antibodies from a third supplier, we received an acceptable staining. Twenty-five percent of the RF animals had a pathological albumin leakage, while the ELF and RF + ELF groups with three and two pathological findings, respectively, were not significantly different from the control group. We conclude that the use of external fans has had no major influence upon the result.
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| 4. |
- Salford, Leif G., et al.
(författare)
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Non-thermal effects of EMF upon the mammalian brain : The Lund experience
- 2007
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Ingår i: The Environmentalist. - : Springer Science and Business Media LLC. - 0251-1088 .- 1573-2991. ; 27:4, s. 493-500
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Tidskriftsartikel (refereegranskat)abstract
- The environment in which biology exists has dramatically changed during the last decades. Life was formed during billions of years, exposed to, and shaped by the original physical forces such as gravitation, cosmic irradiation and the terrestrial magnetism. The existing organisms are created to function in harmony with these forces. However, in the late 19th century mankind introduced the use of electricity and during the very last decades, microwaves of the modern communication society spread around the world. Today one third of the world's population is owner of the microwave-producing mobile phones. The question is: to what extent are living organisms affected by these ubiquitous radio frequency fields? Since 1988 our group has studied the effects upon the mammalian blood-brain barrier (BBB) by non-thermal radio frequency electromagnetic fields (RF-EMF). These have been revealed to cause significantly increased leakage of albumin through the BBB of exposed rats as compared to non-exposed animals-in a total series of about two thousand animals. One remarkable observation is the fact that the lowest energy levels give rise to the most pronounced albumin leakage. If mobile communication, even at extremely low energy levels, causes the users' own albumin to leak out through the BBB, also other unwanted and toxic molecules in the blood, may leak into the brain tissue and concentrate in and damage the neurons and glial cells of the brain. In later studies we have shown that a 2-h exposure to GSM 915 MHz at non-thermal levels, gives rise to significant neuronal damage, seen 28 and 50 days after the exposure. In our continued research, the non-thermal effects (histology, memory functions) of long-term exposure for 13 months are studied as well as the effects of short term GSM 1,800 MHz upon gene expression. Most of our findings support that living organisms are affected by the non-thermal radio frequency fields. Studies from other laboratories in some cases find effects, while in other cases effects are not seen. Our conclusion is that all researchers involved in this field have the obligation to intensify this research in order to reduce, or avoid, the possible negative effects of the man made microwaves!
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| 5. |
- Salinas, Ener, 1957, et al.
(författare)
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A new technique for reducing extremely low frequency magnetic field emissions affecting large building structures
- 2007
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Ingår i: Environmentalist. - 0251-1088 .- 1573-2991. ; 27:4, s. 571-576
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Tidskriftsartikel (refereegranskat)abstract
- When large structures such as residentialcompounds or public buildings are under the influence ofextremely low frequency (ELF) magnetic fields, such asthe one generated by a system of railways fed by16.67 Hz, standard methods of designing shieldingstructures by numerical methods usually fail. The lattercan be explained by the difficulty posed in the computingprocess by the large aspect ratios involved due to thinlayers of metal (a few millimetres or centimetres) incontrast to the large dimensions of the affected structure(several tens of meters). In some cases one has to utilizespecial approximations such as surface conductivity,which are not easy to handle when the designed shieldingstructure is clearly three -dimensional. Other alternativessuch as experimentation in situ are very costly. Here, anew technique is presented of mitigating the field byusing three-dimensional propagation of induced currentsoptimizing the field reduction factors and minimizing thecost of shielding material. The particular designingmethod is a hybrid of numerical simulations combinedwith lab experimentation using scaled models of the largestructure. The method is rather cost-effective and flexible as various designs can be easily tested. Results are presented in the form of magnetic field values, at various locations in the buildings, before and after this mitigation technique is applied.
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| 7. |
- Pogorilyi, Roman, et al.
(författare)
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Urease adsorption and activity on magnetite nanoparticles functionalized with monofunctional and bifunctional surface layers
- 2013
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Ingår i: Journal of Sol-Gel Science and Technology. - : Springer Science and Business Media LLC. - 0928-0707 .- 1573-4846. ; 68, s. 447-454
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Tidskriftsartikel (refereegranskat)abstract
- The surface of magnetite nanoparticles was coated with functional polysiloxane layers using reaction of hydrolytic copolycondensation of tetraethoxysilane and 3-aminopropyltriethoxysilane (or N-[3-trimethoxysilylpropyl] ethylendiamine), and also that of tetraethoxysilane, 3-aminopropyltriethoxysilane and methyltriethoxysilane (or n-propyltriethoxysilane). It was shown that these functionalized magnetically controllable particles (about 60-150 nm in size as aggregates), as opposed to magnetite, adsorb urease well from aqueous solutions (up to 1 g/g), and that the level of residual activity of adsorbed layers is up to 84 % in the case of a bifunctional sample. It was established that the activity of immobilized urease is normally gradually reduced during storage of the samples, but in the case of ethylenediamine functional group is not decreased for 45 days. The synthesized samples are promising for use as magnetically directed biocatalysts.
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| 8. |
- Williams, Quentin Emmanuel, et al.
(författare)
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Multilingualism in transformative spaces : contact and conviviality
- 2013
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Ingår i: Language Policy. - : Springer Science and Business Media LLC. - 1568-4555 .- 1573-1863. ; 12:4, s. 289-311
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Tidskriftsartikel (refereegranskat)abstract
- South Africa is a highly mobile country characterized by historical displacements and contemporary mobilities, both social and demographic. Getting to grips with diversity, dislocation, relocation and anomie, as well as pursuing aspirations of mobility, is part of people's daily experience that often takes place on the margins of conventional politics. A politics of conviviality is one such form of politics of the popular that emerges in contexts of rapid change, diversity, mobility, and the negotiation and mediation of complex affiliations and attachments. The questions in focus for this paper thus pertain to how forms of talk, born out of displacement, anomie and contact in the superdiverse contexts of South Africa, allow for the articulation of life-styles and aspirations that break with the historical faultlines of social and racial oppression. We first expand upon the idea of (marginal) linguistic practices as powerful mediations of political voice and agency, an idea that can be captured in the notion of linguistic citizenship, the rhetorical foundation of a politics of conviviality. We then move on to analyze the workings of linguistic citizenship in the multilingual practices of two distinct manifestations of popular culture, namely hip hop and a performance by a stand-up comedian in Mzoli's meat market in Gugulethu, Cape Town. The paper concludes with a general discussion on the implications for politics of multilingualism and language policy.
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