Sparse thalamocortical convergence

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INDUCTION OF ANTIVIRAL RESPONSE BY ELECTRIC PULSES

Antiviral activity was detected in porcine leukocytes obtained from animals killed in a slaughterhouse. The activity appeared in the supernatant immediately after the addition of Sendai virus, an intended interferon (IFN) inducer. Electroinduction appears to be responsible for the production of antiviral molecules in both porcine and human leukocytes. The macromolecule conferring the antiviral activity is sensitive to heat and pH 2.0 treatment. The preformed or electroinduced antiviral activity originating from porcine leukocytes was not neutralized by either anti-PoIFN-α or anti-PoIFN-γ. The substance involved differs from all known antiviral proteins in that it is not secreted spontaneously into the extracellular space. Its release requires intact and virulent Sendai virus as a trigger signal. Differences in antigenic properties and characteristics indicate that this is a new antiviral substance.     

Synergistic interactions between temporal coupling of complex light and magnetic pulses upon melanoma cell proliferation and planarian regeneration

Synergisms between a physiologically patterned magnetic field that is known to enhance planarian growth and suppress proliferation of malignant cells in culture and three light emitting diode (LED) generated visible wavelengths (blue, green, red) upon planarian regeneration and melanoma cell numbers were discerned. Five days of hourly exposures to either a physiologically patterned (2.5–5.0 μT) magnetic field, one of three wavelengths (3 kLux) or both treatments simultaneously indicated that red light (680 nm), blue light (470 nm) or the magnetic field significantly facilitated regeneration of planarian compared to sham field exposed planarian. Presentation of both light and magnetic field conditions enhanced the effect. Whereas the blue and red light diminished the growth of malignant (melanoma) cells, the effect was not as large as that produced by the magnetic field. Only the paired presentation of the blue light and magnetic field enhanced the suppression. On the other hand, the changes following green light (540 nm) exposure did not differ from the control condition and green light presented with the magnetic field eliminated its effects for both the planarian and melanoma cells. These results indicate specific colors affect positive adaptation that is similar to weak, physiologically patterned frequency modulated (8–24 Hz) magnetic fields and that the two forms of energy can synergistically summate or cancel.     

Climate sensitivity of crop yields in the former state of Andhra Pradesh,India

Observed meteorological data demonstrates that temperature has increased by 0.74 °C in the last hundred years with the bulk of the warming occurring in the last 50 years. This paper examines the impact of climate change on five major crops in the former state of Andhra Pradesh using district level panel data for the period 1981–2010. Analysis of data shows that crop yields are significantly impacted by climate for rice, tobacco and groundnut. Crops grown in rabi are more susceptible to changes in climate than those in kharif, while drought crops like jowar are found to withstand changes in climate better than others.     

Effect of millimeter waves on survival of UVC-exposed Escherichia coli

Bacterial cells of the strain Escherichia coli K12 were exposed to millimeter electromagnetic waves (mm waves) with and without additional exposure to ultraviolet light λ = 254 nm (UVC). The mm waves were produced by a medical microwave generator emitting a 4-GHz-wide band around a 61 GHz center frequency and delivering an irradiation of 1 mW/cm² and a standard absorption rate (SAR) of 84 W/kg to the bacteria. Exposure to the mm waves alone for up to 30 minutes did not change the survival rate of bacteria. Exposure to mm waves followed by UVC irradiation also did not alter the number of surviving E. coli cells in comparison to UVC-treated controls. When mm waves were applied after the UVC exposure, a dose-dependent increase of up to 30% in the survival of E. coli was observed compared to UVC + sham-irradiated bacteria. Because sham controls and experimental samples were maintained under the same thermal conditions, the effect is not likely to be due to heating, although the possibility of nonuniform distribution of microwave heating in different layers of irradiated bacterial suspension cannot be ruled out. The mechanism for this effect appears to involve certain DNA repair systems that act as cellular targets for mm waves. © 1995 Wiley-Liss, Inc.     

Conjoint Measurement of Base Station Siting Preferences

Mobile communication has become a ubiquitous part of today's life. The ongoing growth of this technology, however, involves the construction of new mobile phone base stations in order to assure network coverage. The selection of a new base station site often results in conflicts between providers and public authorities, on the one hand, and residents on the other. The aim of the present study was to examine public preferences regarding base station sites. A random sample of 503 persons from the German speaking part of Switzerland was interviewed face-to-face in their homes. Conjoint analysis was used to evaluate participants’ preferences for various attributes of base stations (appearance, location, building, decision process). The results show that location plays the most important role in participants’ acceptance of base stations. The findings also indicate that most people would prefer a covered or camouflaged base station to a freely visible one. By means of a cluster analysis, several segments were distinguished, showing that base station siting preferences were not homogeneous. Implications for risk communication are discussed.     

Taking Advantage of Reduced Droplet-surface Interaction to Optimize Transport of Bioanalytes in Digital Microfluidics

Digital microfluidics (DMF), a technique for manipulation of droplets, is a promising alternative for the development of “lab-on-a-chip” platforms. Often, droplet motion relies on the wetting of a surface, directly associated with the application of an electric field; surface interactions, however, make motion dependent on droplet contents, limiting the breadth of applications of the technique.Some alternatives have been presented to minimize this dependence. However, they rely on the addition of extra chemical species to the droplet or its surroundings, which could potentially interact with droplet moieties. Addressing this challenge, our group recently developed Field-DW devices to allow the transport of cells and proteins in DMF, without extra additives.Here, the protocol for device fabrication and operation is provided, including the electronic interface for motion control. We also continue the studies with the devices, showing that multicellular, relatively large, model organisms can also be transported, arguably unaffected by the electric fields required for device operation.     

Transient and cumulative memory impairments induced by GSM 1.8 GHz cell phone signal in a mouse model

This study was designed to investigate the transient and cumulative impairments in spatial and non-spatial memory of C57Bl/6J mice exposed to GSM 1.8 GHz signal for 90 min daily by a typical cellular (mobile) phone at a specific absorption rate value of 0.11 W/kg. Free-moving male mice 2 months old were irradiated in two experimental protocols, lasting for 66 and for 148 days respectively. Each protocol used three groups of animals (n = 8 each for exposed, sham exposed and controls) in combination with two behavioural paradigms, the object recognition task and the object location task sequentially applied at different time points. One-way analysis of variance revealed statistically significant impairments of both types of memory gradually accumulating, with more pronounced effects on the spatial memory. The impairments persisted even 2 weeks after interruption of the 8 weeks daily exposure, whereas the memory of mice as detected by both tasks showed a full recovery approximately 1 month later. Intermittent every other day exposure for 1 month had no effect on both types of memory. The data suggest that visual information processing mechanisms in hippocampus, perirhinal and entorhinal cortex are gradually malfunctioning upon long-term daily exposure, a phenotype that persists for at least 2 weeks after interruption of radiation, returning to normal memory performance levels 4 weeks later. It is postulated that cellular repair mechanisms are operating to eliminate the memory affecting molecules. The overall contribution of several possible mechanisms to the observed cumulative and transient impairments in spatial and non-spatial memory is discussed.     

Metacommunities of spiders in grassland habitat fragments of an agricultural landscape

Arthropod communities in fragmented agricultural landscapes depend on local processes and the interactions between communities in the habitat islands. We aimed to study metacommunity structure of spiders, a group that is known for high dispersal power, local niche partitioning and for engaging in species interactions. While living in fragmented habitats could lead to nestedness, other ecological traits of spiders might equally lead to patterns dominated either by species interactions or habitat filtering. We asked, which community pattern will prevail in a typical agricultural landscape with isolated patches of semi-natural habitats. Such a situation was studied by sampling spiders in 28 grassland locations in a Hungarian agricultural landscape. We used the elements of metacommunity structure (EMS) framework to distinguish between alternative patterns that reveal community organization. The EMS analysis indicated coherent species ranges, high turnover and boundary clumping, suggesting Clementsian community organization. The greatest variation in species composition was explained by local habitat characteristics, indicating habitat filtering. The influence of dispersal could be detected by the significant effect of landscape composition, which was strongest at 500 m. We conclude that dispersal allows spiders to respond coherently to the environment, creating similar communities in similar habitats. Consistent habitat differences, such as species rich versus species poor vegetation, lead to recognisably different, recurrent communities. These characteristics make spiders a predictable and diverse source of natural enemies in agricultural landscapes. Sensitivity to habitat composition at medium distances warns us that landscape homogenization may alter these metacommunity processes.     

A new algorithm quantifies the roles of wind and midge flight activity in the bluetongue epizootic in northwest Europe

The 2006 bluetongue (BT) outbreak in northwestern Europe had devastating effects on cattle and sheep in that intensively farmed area. The role of wind in disease spread, through its effect on Culicoides dispersal, is still uncertain, and remains unquantified. We examine here the relationship between farm-level infection dates and wind speed and direction within the framework of a novel model involving both mechanistic and stochastic steps. We consider wind as both a carrier of host semio-chemicals, to which midges might respond by upwind flight, and as a transporter of the midges themselves, in a more or less downwind direction. For completeness, we also consider midge movement independent of wind and various combinations of upwind, downwind and random movements. Using stochastic simulation, we are able to explain infection onset at 94 per cent of the 2025 affected farms. We conclude that 54 per cent of outbreaks occurred through (presumably midge) movement of infections over distances of no more than 5 km, 92 per cent over distances of no more than 31 km and only 2 per cent over any greater distances. The modal value for all infections combined is less than 1 km. Our analysis suggests that previous claims for a higher frequency of long-distance infections are unfounded. We suggest that many apparent long-distance infections resulted from sequences of shorter-range infections; a 'stepping stone' effect. Our analysis also found that downwind movement (the only sort so far considered in explanations of BT epidemics) is responsible for only 39 per cent of all infections, and highlights the effective contribution to disease spread of upwind midge movement, which accounted for 38 per cent of all infections. The importance of midge flight speed is also investigated. Within the same model framework, lower midge active flight speed (of 0.13 rather than 0.5 m s(-1)) reduced virtually to zero the role of upwind movement, mainly because modelled wind speeds in the area concerned were usually greater than such flight speed. Our analysis, therefore, highlights the need to improve our knowledge of midge flight speed in field situations, which is still very poorly understood. Finally, the model returned an intrinsic incubation period of 8 days, in accordance with the values reported in the literature. We argue that better understanding of the movement of infected insect vectors is an important ingredient in the management of future outbreaks of BT in Europe, and other devastating vector-borne diseases elsewhere.