Patterns of Infant Mortality in the Upper St. John Valley French Population: 1791-1838

The purpose of this paper is to provide a descriptive analysis of infant mortality patterns in a pre-industrial North American population, the Madawaska French of the upper St. John Valley. A synchronic approach was taken in examining a series of 320 infant deaths identified through family reconstitution. The infant mortality rate for the series is 132 per 1000, low compared to other pre-industrial populations. The large average completed family size of 11.34 is associated with short birth intervals averaging 21.9 months. Women who experience infant mortality were found to have significantly larger completed families that those who did not. Infant mortality risk was positively associated with larger ultimate family size, but was unrelated to birth order. Patterns of high fertility and low infant mortality are attributed to the process of colonization and population expansion in a relatively isolated area

Patterns of Infant Mortality in the Upper St. John Valley French Population: 1791-1838

The purpose of this paper is to provide a descriptive analysis of infant mortality patterns in a pre-industrial North American population, the Madawaska French of the upper St. John Valley. A synchronic approach was taken in examining a series of 320 infant deaths identified through family reconstitution. The infant mortality rate for the series is 132 per 1000, low compared to other pre-industrial populations. The large average completed family size of 11.34 is associated with short birth intervals ranging 21.9 months. Women who experience infant mortality were found to have significantly larger completed families than those who did not. Infant mortality risk was positively associated with larger ultimate family size, but was unrelated to birth order. Patterns of high fertility and low infant mortality are attributed to the process of colonization and population expansion in a relatively isolated are

Scientific Bases for a Participatory Forest Landscape Management

In Madagascar – a biodiversity hotspot of international importance – the villagers depend on the forest first for its soil as a reserve of arable land as well as a shelter and a pasture for the herds, and second for the production of timber, charcoal and other forest products. Most of the currently proposed conservation management systems for forests do not take into consideration villagers’ needs, in Madagascar too; indeed degradation and deforestation have continuously occurred in places where the forest is under great pressure. In targeting the improvement of the livelihood of local populations and the maintenance of “multifunctionality”, especially the ecological value of the forest, the present project aims at developing scientific criteria for a sustainable management of forest landscapes in western Madagascar at a regional scale. A detailed inventory of resources and a specific understanding of stakeholder requirements and strategies will allow drawing an accurate picture of the human-forest interface. A participatory approach paves the way for realistic management criteria that are really adequate to the ecological and social situations. The management criteria will provide a tool for further discussions on landscape management in central Menabe

Effect of Protein Level, Lysine and Oats in Diets for Growing-Finishing Pigs

Previous research has shown that the protein content of swine diets can be reduced approximately two percent if the diet is supplemented with lysine and if the diet is not deficient in other amino acids. Corn-soybean meal diets that are reduced more than two percent in protein may become deficient in the amino acid tryptophan. Oats contains more lysine and tryptophan but less energy than corn. However, dietary levels of 20 to 30% oats have generally not affected pig performance. The objectives of this experiment were to evaluate the protein and lysine needs of growing-finishing pigs and to determine the value of oats as an amino acid source in low protein diets containing 20% oats as a replacement for corn

Distinctive correspondence between separable visual attention functions and intrinsic brain networks

Separable visual attention functions are assumed to rely on distinct but interacting neural mechanisms. Bundesen's “theory of visual attention” (TVA) allows the mathematical estimation of independent parameters that characterize individuals' visual attentional capacity (i.e., visual processing speed and visual short-term memory storage capacity) and selectivity functions (i.e., top-down control and spatial laterality). However, it is unclear whether these parameters distinctively map onto different brain networks obtained from intrinsic functional connectivity, which organizes slowly fluctuating ongoing brain activity. In our study, 31 demographically homogeneous healthy young participants performed whole- and partial-report tasks and underwent resting-state functional magnetic resonance imaging (rs-fMRI). Report accuracy was modeled using TVA to estimate, individually, the four TVA parameters. Networks encompassing cortical areas relevant for visual attention were derived from independent component analysis of rs-fMRI data: visual, executive control, right and left frontoparietal, and ventral and dorsal attention networks. Two TVA parameters were mapped on particular functional networks. First, participants with higher (vs. lower) visual processing speed showed lower functional connectivity within the ventral attention network. Second, participants with more (vs. less) efficient top-down control showed higher functional connectivity within the dorsal attention network and lower functional connectivity within the visual network. Additionally, higher performance was associated with higher functional connectivity between networks: specifically, between the ventral attention and right frontoparietal networks for visual processing speed, and between the visual and executive control networks for top-down control. The higher inter-network functional connectivity was related to lower intra-network connectivity. These results demonstrate that separable visual attention parameters that are assumed to constitute relatively stable traits correspond distinctly to the functional connectivity both within and between particular functional networks. This implies that individual differences in basic attention functions are represented by differences in the coherence of slowly fluctuating brain activity

Transcriptional analysis of temporal gene expression in germinating Clostridium difficile 630 endospores.

Clostridium difficile is the leading cause of hospital acquired diarrhoea in industrialised countries. Under conditions that are not favourable for growth, the pathogen produces metabolically dormant endospores via asymmetric cell division. These are extremely resistant to both chemical and physical stress and provide the mechanism by which C. difficile can evade the potentially fatal consequences of exposure to heat, oxygen, alcohol, and certain disinfectants. Spores are the primary infective agent and must germinate to allow for vegetative cell growth and toxin production. While spore germination in Bacillus is well understood, little is known about C. difficile germination and outgrowth. Here we use genome-wide transcriptional analysis to elucidate the temporal gene expression patterns in C. difficile 630 endospore germination. We have optimized methods for large scale production and purification of spores. The germination characteristics of purified spores have been characterized and RNA extraction protocols have been optimized. Gene expression was highly dynamic during germination and outgrowth, and was found to involve a large number of genes. Using this genome-wide, microarray approach we have identified 511 genes that are significantly up- or down-regulated during C. difficile germination (p≤0.01). A number of functional groups of genes appeared to be co-regulated. These included transport, protein synthesis and secretion, motility and chemotaxis as well as cell wall biogenesis. These data give insight into how C. difficile re-establishes its metabolism, re-builds the basic structures of the vegetative cell and resumes growth

Impaired visual short-term memory capacity is distinctively associated with structural connectivity of the posterior thalamic radiation and the splenium of the corpus callosum in preterm-born adults

Preterm birth is associated with an increased risk for lasting changes in both the cortico-thalamic system and attention; however, the link between cortico-thalamic and attention changes is as yet little understood. In preterm newborns, cortico-cortical and cortico-thalamic structural connectivity are distinctively altered, with increased local clustering for cortico-cortical and decreased integrity for cortico-thalamic connectivity. In preterm-born adults, among the various attention functions, visual short-term memory (vSTM) capacity is selectively impaired. We hypothesized distinct associations between vSTM capacity and the structural integrity of cortico-thalamic and cortico-cortical connections, respectively, in preterm-born adults. A whole-report paradigm of briefly presented letter arrays based on the computationally formalized Theory of Visual Attention (TVA) was used to quantify parameter vSTM capacity in 26 preterm- and 21 full-term-born adults. Fractional anisotropy (FA) of posterior thalamic radiations and the splenium of the corpus callosum obtained by diffusion tensor imaging were analyzed by tract-based spatial statistics and used as proxies for cortico-thalamic and cortico-cortical structural connectivity. The relationship between vSTM capacity and cortico-thalamic and cortico-cortical connectivity, respectively, was significantly modified by prematurity. In full-term-born adults, the higher FA in the right posterior thalamic radiation the higher vSTM capacity; in preterm-born adults this FA-vSTM-relationship was inversed. In the splenium, higher FA was correlated with higher vSTM capacity in preterm-born adults, whereas no significant relationship was evident in full-term-born adults. These results indicate distinct associations between cortico-thalamic and cortico-cortical integrity and vSTM capacity in preterm-and full-term-born adults. Data suggest compensatory cortico-cortical fiber re-organization for attention deficits after preterm delivery

Evoked responses to rhythmic visual stimulation vary across sources of intrinsic alpha activity in humans

Rhythmic flickering visual stimulation produces steady-state visually evoked potentials (SSVEPs) in electroencephalogram (EEG) recordings. Based on electrode-level analyses, two dichotomous models of the underpinning mechanisms leading to SSVEP generation have been proposed: entrainment or superposition, i.e., phase-alignment or independence of endogenous brain oscillations from flicker-induced oscillations, respectively. Electrode-level analyses, however, represent an averaged view of underlying ‘source-level’ activity, at which variability in SSVEPs may lie, possibly suggesting the co-existence of multiple mechanisms. To probe this idea, we investigated the variability of SSVEPs derived from the sources underpinning scalp EEG responses during presentation of a flickering radial checkerboard. Flicker was presented between 6 and 12 Hz in 1 Hz steps, and at individual alpha frequency (IAF i.e., the dominant frequency of endogenous alpha oscillatory activity). We tested whether sources of endogenous alpha activity could be dissociated according to evoked responses to different flicker frequencies relative to IAF. Occipitoparietal sources were identified by temporal independent component analysis, maximal resting-state alpha power at IAF and source localisation. The pattern of SSVEPs to rhythmic flicker relative to IAF was estimated by correlation coefficients, describing the correlation between the peak-to-peak amplitude of the SSVEP and the absolute distance of the flicker frequency from IAF across flicker conditions. We observed extreme variability in correlation coefficients across sources, ranging from −0.84 to 0.93, with sources showing largely different coefficients co-existing within subjects. This result demonstrates variation in evoked responses to flicker across sources of endogenous alpha oscillatory activity. Data support the idea of multiple SSVEP mechanisms