No effects of mobile phone use on cortical auditory change‐detection in children: An ERP study

We investigated the effect of mobile phone use on the auditory sensory memory in children. Auditory event‐related potentials (ERPs), P1, N2, mismatch negativity (MMN), and P3a, were recorded from 17 children, aged 11–12 years, in the recently developed multi‐feature paradigm. This paradigm allows one to determine the neural change‐detection profile consisting of several different types of acoustic changes. During the recording, an ordinary GSM (Global System for Mobile Communications) mobile phone emitting 902 MHz (pulsed at 217 Hz) electromagnetic field (EMF) was placed on the ear, over the left or right temporal area (SAR_1g = 1.14 W/kg, SAR_10g = 0.82 W/kg, peak value = 1.21 W/kg). The EMF was either on or off in a single‐blind manner. We found that a short exposure (two 6 min blocks for each side) to mobile phone EMF has no statistically significant effects on the neural change‐detection profile measured with the MMN. Furthermore, the multi‐feature paradigm was shown to be well suited for studies of perception accuracy and sensory memory in children. However, it should be noted that the present study only had sufficient statistical power to detect a large effect size. Bioelectromagnetics 31:191–199, 2010. © 2009 Wiley‐Liss, Inc.     

Joint-specific twin and familial aggregation of recalled physician diagnosed osteoarthritis.

In our three-stage questionnaire study we investigated patterns of twin and familial aggregation of osteoarthritis (OA) for commonly affected joints. The baseline questionnaire study of the Finnish Twin Cohort was performed in 1975. In 1990, 4095 twin pairs of the same gender born 1930-1957 responded to a questionnaire and reported whether they had OA diagnosed by a physician. In 1996 both twins of 266 pairs of which at least one had reported OA in 1990 responded to a detailed questionnaire on joint-specific OA, including family history of OA. In male pairs shared (non-genetic) familial effects accounted for 37% of the total variance in liability to OA and unshared environmental effects for 63%. In female pairs additive gene effects explained 44% of the variance in liability to OA, and unshared environmental effects for 36%. Familial aggregation of finger and knee OA was clearly higher than that of hip OA. Twin-pair discordance for OA was, to some extent, associated with body-mass index, occupational loading and trauma. Our results indicate that genetic effects may be modulated by sex or by environmental factors distributed differently between men and women. Based on our joint-specific data finger and knee joints are the most optimal targets for studies of genetic factors predisposing to the development of OA.     

Species immigration, extinction and turnover of vascular plants in boreal lakes

Dictated by limited resource availability for land acquisition, a central question in conservation biology is the ability of areas of different size to maintain species diversity. The selected reserves should not only be species rich at the moment, but should also maintain species diversity in the long run. We used two sets of data on vascular plant species in boreal lakes collected in 1933/34 and 1996 to test the relationships between lake area and the extinction, immigration and turnover rates of the species. Moreover, we investigated, whether the number of species in 1933/34 or water connection between lakes was related to extinction, immigration and turnover rates of species. We found that lake area or shoreline length was not correlated with immigration or turnover rate. But extinction rate was slightly negatively correlated with shoreline length. The original number of species was positively related to the number of species extinctions and to the absolute turnover rate in the lakes, which indicates that species richness does not create stability in these communities. Species number was not correlated with immigration rate. Upstream water connections in the lakes did not affect immigration, extinction or turnover rates. We conclude that length of the shoreline is a better measure of suitable area for water plants than the lake area, and that because the correlation between shoreline length and extinction rate was slight, also small lakes can be valuable for conservation.     

Identifying ‘climate keystone species’ as a tool for conserving ecological communities under climate change

Aim

Climate change affects ecological communities via impacts on species. The community's response to climate change can be represented as the temporal trend in a climate-related functional property that is quantified using a relevant functional trait. Noteworthy, some species influence this response in the community more strongly than others.

Innovation

Leveraging on the concept of keystone species, we propose that species with a strong effect on the community's functional response to climate change beyond their relative abundance can be considered as ‘climate keystone species’. We develop a stepwise tool to determine species' effects on a community's climate response and identify climate keystone species. We quantify the species-specific effect by measuring the difference in the community's climate response with and without the species. Next, we identify climate keystone species as those with a strong residual effect after weighting with their relative abundances in the community.

Main Conclusions

To illustrate the use of the stepwise tool with empirical data, we identify climate keystone species that have a strong effect on the change in the average temperature niche in North American bird communities over time and find the identification tool ecologically relevant. Identification of climate keystone species can serve as an additional conservation method to efficiently protect ecological communities and, in turn, the ecosystem functions they provide.     

Pigmented variants of Tolypocladium inflatum in relation to cyclosporin A production

Summary We have isolated four distinct colony types of the fungus Tolypocladium inflatum, the producer of the immunosuppresive agent cyclosporin A: morphologically normal white, red, and orange colonies and morphologically diverse tiny brown colonies. In liquid cultures, white normal and brown colonies developed into yellow broths. The broth of the brown colony had a low final pH and low cyclosporin production, whereas orange and red colonies had dark brown and even black broths with higher final pH and high cyclosporin production. The specific production of cyclosporin A by the red colony was three times that of the white normal colonies. Offprint requests to: S. N. Agathos     

Timing an ontogenetic niche shift: responses of emerging salmon alevins to chemical cues from predators and competitors

Ontogenetic niche shifts are ubiquitous in nature. However, in most species little is known about phenotypic plasticity in the timing of shifts and in the associated characters. Following a period of endogenous feeding on yolk, salmonid alevins emerge from their gravel nests into the open water and start feeding exogenously. We studied, by using replicated artificial nests, whether the responses of emerging Atlantic salmon ( Salmo salar ) alevins to chemical cues from two piscivorous fish predators and conspecific competitors are plastic. We hypothesised that the alevins should delay emergence in response to predator cues, whereas cues from competitors should induce earlier emergence. We found that chemical cues from predatory burbot ( Lota lota ) delayed emergence, whereas cues from brown trout ( S. trutta ) tended to induce earlier emergence. The earlier emergence in response to trout cues was associated with a smaller body size and more yolk resources remaining at emergence, but burbot cues did not alter these traits. Predator cues also influenced the daily pattern of emergence: more alevins emerged during the morning in the burbot treatment, and fewer alevins emerged during the afternoon in the trout treatment. Chemical cues from conspecific competitors had no effect on emergence patterns. The results indicate that salmon alevins exhibit flexible ontogenetic niche shifts in the timing of emergence in response to predator cues, and that the responses are predator-specific. As timing of emergence is a major determinant of territory acquisition, these responses are likely to have an impact on later fitness of the fry.     

Strength characteristics of a healthy urban adult population

A random sample of 778 subjects representing ages 25, 35, 45 and 55 years were studied for the amount of habitual physical activity, their anthropometric structure, vertical jumping height, trunk extension and flexion torques and dynamic endurance fitness of trunk extension and flexion. The proportion of subjects who were habitually physically active did not change systematically with age. The highest number of physically inactive subjects was found in men and women in the 35-year age group. The results in all the tests used to assess the strength characteristics were statistically significant when related to sex (P less than 0.001) and in all, except the relative maximal isometric torque of trunk extension, when related to age (P less than 0.001). Everyday physical activity was related to the variation in vertical jumping height (P less than 0.001), as well to the dynamic endurance fitness (P less than 0.001) of trunk extension and flexion. The decline in vertical jumping height and dynamic endurance fitness of trunk extension and flexion fitness was found to start at earlier ages than that of relative maximal isometric trunk extension and flexion torques. Dynamic endurance fitness of trunk flexion showed a more pronounced decline with age than trunk extension fitness.