The increased population of the Wild Boar (Sus scrofa L.) in Europe

In this paper the recent population changes of the Wild Boar in different European countries is analysed through the study of hunting statistics. A simultaneous increase in numbers is observed throughout the whole area during the period 1965–1975. From 1975 onwards the population stabilizes itself apart from in peripheral areas like Finland. Potentially favourable factors which play a part in this process are discussed and certain reproductive and dispersive characteristics which favour its invasive behaviour are discussed.     

Neuronal expression of a single‐subunit yeast NADH–ubiquinone oxidoreductase (Ndi1) extends Drosophila lifespan

The ‘rate of living’ theory predicts that longevity should be inversely correlated with the rate of mitochondrial respiration. However, recent studies in a number of model organisms, including mice, have reported that interventions that retard the aging process are, in fact, associated with an increase in mitochondrial activity. To better understand the relationship between energy metabolism and longevity, we supplemented the endogenous respiratory chain machinery of the fruit fly Drosophila melanogaster with the alternative single‐subunit NADH–ubiquinone oxidoreductase (Ndi1) of the baker’s yeast Saccharomyces cerevisiae. Here, we report that expression of Ndi1 in fly mitochondria leads to an increase in NADH–ubiquinone oxidoreductase activity, oxygen consumption, and ATP levels. In addition, exogenous Ndi1 expression results in increased CO₂ production in living flies. Using an inducible gene‐expression system, we expressed Ndi1 in different cells and tissues and examined the impact on longevity. In doing so, we discovered that targeted expression of Ndi1 in fly neurons significantly increases lifespan without compromising fertility or physical activity. These findings are consistent with the idea that enhanced respiratory chain activity in neuronal tissue can prolong fly lifespan.     

The timing of eruption of the primary dentition in Nigerian children

The objectives of this study were to clarify the eruption time and sequence for primary teeth in Nigerian children. It also investigated the effect of sex and socioeconomic status on the timing and sequence of eruption. A random sample of 1,657 children from ages of 3-40 months were examined--921 (55.6%) males and 736 (44.4%) females. The age of eruption of the teeth was estimated using probit regression. The results show that there was no effect of sex, socioeconomic status or breastfeeding status on the timing of eruption and pattern of teeth eruption in Nigerian children. Left and right teeth had similar eruption times. Eruption times of the lateral incisor, canine, and molars were similar for upper and lower teeth. Interpopulation studies however showed that though the sequence of eruption of primary teeth in Nigerian population is similar to that of their peers in other compared populations, there are observable sex differences in the timing of tooth eruption.     

Neurocognitive processing of esophageal central sensitization in the insula and cingulate gyrus

The cingulate and insular cortices are parts of the limbic system that process and modulate gastrointestinal sensory signals. We hypothesized that sensitization of these two limbic area may operate in esophageal sensitization. Thus the objective of the study was to elucidate the neurocognitive processing in the cingulate and insular cortices to mechanical stimulation of the proximal esophagus following infusion of acid or phosphate buffer solution (PBS) into the esophagus. Twenty-six studies (14 to acid and 12 to PBS infusion) were performed in 20 healthy subjects (18-35 yr) using high-resolution (2.5 x 2.5 x 2.5 mm(3) voxel size) functional MRI (fMRI). Paradigm-driven, 2-min fMRI scans were performed during randomly timed 15-s intervals of proximal esophageal barostatically controlled distentions and rest, before and after 30-min of distal esophageal acid or PBS perfusion (0.1 N HCl or 0.1 M PBS at 1 ml/min). Following distal esophageal acid infusion, at subliminal and liminal levels of proximal esophageal distentions, the number of activated voxels in both cingulate and insular cortices showed a significant increase compared with before acid infusion (P < 0.05). No statistically significant change in cortical activity was noted following PBS infusion. We conclude that 1) acid stimulation of the esophagus results in sensitization of the cingulate and insular cortices to subliminal and liminal nonpainful mechanical stimulations, and 2) these findings can have ramifications with regard to the mechanisms of some esophageal symptoms attributed to reflux disease.     

Statistical Analyses of Twins Birth Data from a Nigerian Sample

In this paper, both the linear logistic model and its analogous linear model (weighted least squares) are fitted to twin birth data from a Nigerian sample. The logits of the observed perinatal mortality rates are fitted against the birthweight of breech infants for both first born and second born twins. Results show that a quadratic response model fits the data very well, and that the WLS procedure gives a better fit. The results further show that breech births necessarily result in 7.7% and 11.2% mortality rates respectively for first born and second born twins. The results of a log-linear model analysis on the 2×2×4 contingency table formed by the factors, ‘mode of birth’, and twins with the response variable ‘Apgar Scores’-an index of morbidity-also show that both factors play significant roles in explaining the variation of the response variable. It was found that the most important factor effecting the ability of a twin infant to survive as measured by the Apgar scores is the variable ‘mode of birth’ (vertex or breech). In other words, a vertex first twin infant has the best survival chance.     

Comparisons of Some Chi-Squared Goodness-of-Fit Test Statistics in Sparse One-Way Multinomials

The behavior of Pearson's X² test, the likelihood ratio test Y² and the two of its derivatives, G² and G_k², the Freeman-Tukey test (FT) and the Cressie and Read test Statistic I(2/3) are examined in this study. Estimated attained α levels based on 1000 simulated samples when the approximating distribution is χ_k-1², are computed for these tests for the various values of k, n and seven null hypotheses. Results from estimated power computations indicate that none of the test statistics has a clear advantage over any others, and that the choice of which test to use must therefore rest mainly on the performances with regards to the attained α levels when the χ² approximation is invoked. In this respect, the log-normal approximation proposed by Lawal and Upton (1980) is strongly recommended. This is closely followed by the I(2/3).