Fitting probability models to population dynamics data

Methods for modeling population dynamics in probability using the generalized point process approach are developed. The life history of these populations is such that seasonal reproduction occurs during a short time. Several models are developed and analyzed. Data about two species: colonial spiders (Stegodyphus dumicola) and a migratory bird (wood thrush, Hylocichla mustelina) are used to estimate model parameters with appropriate log maximum likelihood functions. For the spiders, the model is fitted to provide evolutionary feasible colony size based on maximum likelihood estimates of fecundity and survival data. For the migratory bird species, a maximum likelihood estimates are derived for the fecundity and survival rates of young and adult birds and immigration rate. The presented approach allows computation of quantities of interest such as probability of extinction and average time to extinction.     

A knowledge map for describing variegated and conflict domains of sustainable development

This paper aims to draw a knowledge map of the fragmented and multidisciplinary literature of sustainable development. Through the process of metaphor making, the study identifies seven metaphors that together construct this map. Each metaphor represents a specific domain in this map. The metaphor of ethical paradox signifies the ethical domain; the material domain is represented through the metaphor of natural capital, the social domain through the metaphor of fairness, the spatial domain through the eco‐form metaphor, the political domain through the global discourse metaphor, the management domain through the integrative management metaphor, and the visionary domain through the utopian metaphor. The strength of this approach lies with its comprehensive representation of the complex sustainable development world. Its main weakness relies on the accurate representation of this map.     

The influence of soil pollution on soil microbial biomass and nematode community structure in Navoiy Industrial Park, Uzbekistan

The effects of ammonium-rich and heavy-metal air pollution produced by the industrial enterprises at Navoiy (Uzbekistan) on soil free-living nematodes and microbial population activities was investigated in soil samples collected in a 5-km radius surrounding the industrial enterprises. At each location (n=4), soil samples were collected from the upper layer (0-10 cm) for determination of soil moisture (SM), total organic carbon (C(org)), total soluble nitrogen (TSN), soil electrical conductivity (EC) and cations (Ca(2+), K(+), Na(+)). Heavy metals (As, Cu, Pb, Zn), soil basal respiration (BR), microbial biomass (C(mic)) and nematode populations were determined. The highest level of TSN was found near the industrial enterprises, with 23.8 and 24.0 mg/kg at NavoiAzot and NavoiGRES, respectively. Soil sample pH was found to be weakly alkaline, with levels ranging between 7.9 and 8.1. Mean soil moisture content varied from 0.75% to 0.93% of the wet weight, without any significant differences between the sampling stations. The heavy metals As, Cu, Pb and Zn were accumulated in the upper soil layer. A significant difference was found between soil heavy-metal content for Cu (p<0.0005) and As (p<0.02). Basal respiration and microbial coefficient (C(mic)/C(org)) were found to be significantly negatively correlated with Cu and As soil content. A significantly positive correlation was found between the Cd concentration and the metabolic quotient (qCO(2)) (p<0.003). No significant correlation was observed between the soil microbial population and total soluble nitrogen. Furthermore, the qCO(2), which is a known ecophysiological index for the soil microbial population, was found to be correlated with the total number of nematodes in general and with the bacteriovore-feeding group in particular. No significant correlation was observed between the soil microbial population and total soluble nitrogen.     

Influence of industrial heavy metal pollution on soil free-living nematode population

The effect of distance from a heavy metal pollution source on the soil nematode community (trophic structure, sex structure, and taxa composition) was investigated along a 15-km transect originating at the Almalyk Industrial Complex, Uzbekistan (pollution source). The soil nematode community was exposed to heavy metal influence both directly and through soil properties changes. Pollution effect on the density and biomass of soil free-living nematodes was found to be highest at pollution source, with fungivores and plant parasites dominating at the upper and deeper soil layers next to the pollution source. These groups decreased along the transect, yielding domination to bacteria- and fungi-feeders. The sex ratio of nematode communities was found to be dependent on heavy metal pollution levels, with the juveniles being the most sensitive nematode group. The Maturity and modified Maturity Indices, reflecting the degree of disturbance of the soil ecosystem, were found to be the most sensitive indices.     

Social media and scientific research are complementary—YouTube and shrikes as a case study

Fascination with animals and their behaviour is one the most prominent patterns persisting in all human cultures. During the last decades, however, technological development and public access to the Internet have increased the speed and the extent of information sharing at an unprecedented rate, in some cases even challenging the traditional methods used in science. In order to understand the extent of this influence, we focused on the behaviour of shrikes. Shrikes are an enigmatic group of songbirds with a unique behaviour of impaling prey. We employed an extensive Internet search on YouTube (YT), a very popular and increasingly important source of information worldwide, for videos recording shrikes. Our analyses revealed that the number of shrike videos on YT is strongly positively correlated with classical knowledge on shrikes from books and scientific articles. Our results also suggest that in some cases YT may provide an alternative source of information on shrike ecology and behaviour. YT videos may thus provide new insights into the study of certain species or subjects and help identify gaps in ecological studies, especially in poorly studied species.     

Prenatal ultrasound diagnosis of gastric outlet obstruction due to a pyloric web

Gastrointestinal tract atresia has an incidence of 1 in 10 000 live-births, while gastric outlet obstruction comprises only approximately 1 per cent of these malformations. A prenatally diagnosed case is described, followed by a discussion regarding the diagnosis and possible associated abnormalities.     

Prenatal diagnosis of familial congenital pyloric atresia

Familial congenital pyloric atresia is a rare malformation of the fetal gastrointestinal tract. It usually manifests as maternal polyhydramnios and enlarged fetal stomach on ultrasound scan. Sonographic prenatal diagnosis and management of a pregnancy complicated by familial congenital pyloric atresia are presented.