Stochastic-rheological Simulation of Free-fall Arm Impact in Children: Application to Playground Injuries

The aim of this study was to develop and pilot a stochastic-rheological biomechanical model to investigate the mechanics of impact fractures in the upper limbs of children who fall in everyday situations, such as when playing on playground equipment. The rheological aspect of the model characterises musculo-skeletal tissues in terms of inertial, elastic and viscous parameters. The stochastic aspect of the model allows natural variation of children's musculo-skeletal mechanical properties to be accounted for in the analysis. The relationship of risk factors, such as fall height, impact surface, child mass and bone density, to the probability of sustaining an injury in playground equipment falls were examined and found to closely match findings in epidemiological, clinical and biomechanical literature. These results suggest that the stochastic-rheological model is a useful tool for the evaluation of arm fracture risk in children. Once fully developed, information from this model will provide the basis for recommendations for modifications to playground equipment and surface standards.     

Digestive and metabolic utilization of lauric,myristic and stearic acid in cows,and associated effects on milk fat quality

A study was carried out to examine the effect of dietary supplementation of oregano essential oil on performance of broiler chickens experimentally infected with Eimeria tenella at 14 days of age. A total of 120 day-old Cobb-500 chicks separated into 4 equal groups with three replicates each, were used in this study. Two groups, one infected with 5·10⁴ sporulated oocysts of E. tenella and the other not, were given a basal diet and served as controls. The other two groups also infected with E. tenella were administered diets supplemented with oregano essential oil at a level of 300 mg/kg, or with the anticoccidial lasalocid at 75 mg/kg. Following this infection, survival rate, bloody diarrhoea and oocysts excretion as well as lesion score were determined. Throughout the experimental period of 42 days, body weight gain and feed intake were recorded weekly, and feed conversion ratios were calculated. Two weeks after the infection with E. tenella supplementation with dietary oregano oil resulted in body weight gains and feed conversion ratios not differing from the non-infected group, but higher than those of the infected control group and lower than those of the lasalocid group. These parameters correspond with the extent of bloody diarrhoea, survival rate, lesion score and oocyst numbers and indicated that oregano essential oil exerted an anticoccidial effect against E. tenella, which was, however, lower than that exhibited by lasalocid.     

Improved expansion of T cells in culture when isolated with an equipment-free,high-throughput,flow-through microfluidic module versus traditional density gradient centrifugation

Background

The isolation of lymphocytes – and removal of platelets (PLTs) and red blood cells (RBCs) – from an initial blood sample prior to culture is a key enabling step for effective manufacture of cellular therapies. Unfortunately, currently available methods suffer from various drawbacks, including low cell recovery, need for complex equipment, potential loss of sterility and/or high materials/labor cost.

Rare element concentrations indicating agglutinated character of Lower Cambrian Platysolenites tubes

Felitsyn, S. B. 1992 04 15: Rare element concentrations indicating agglutinated character of Lower Cambrian Platysolenites tubes. Lethaia , Vol. 25, pp. 131–133. Oslo. ISSN 9924–1164.
Data on rare element contents in siliceous tubes of Platysolenites antiquissimus from Lontova Beds were obtained. Low metal contents and REE patterns serve as indications of the presence of quartz in the tube substance. X-ray analysis detected the quartz and K-feldspars. Information on tube composition suggests their agglutinated character, since siliceous minerals are not a single component of the tubes and an affinity between Platysolenites and Foraminifera is quite possible. * Plarysolenites, Lower Cambrian, rare elements .     

Systematics of the Neotropical braconid wasps of the Pedinotus genus group (Doryctinae)

The braconid subfamily Doryctinae (Hymenoptera) is a cosmopolitan, species‐rich group of parasitoid wasps whose known species richness and morphological diversity is mainly concentrated in the Neotropical region. Among the doryctine taxa that are endemic to this region, there is a group of six genera (the Pedinotus genus group) that are mainly characterized by having lateral, posteriorly converging or subparallel grooves on the second metasomal tergite (including Gymnobracon Szépligeti, Hybodoryctes Szépligeti, Lamquetia Braet et van Achterberg, Osmophila Szépligeti, Pedinotus Szépligeti and Trigonophasmus Enderlein). Most of these genera were described more than a century ago, and thus their limits and diagnostic morphological features are not well defined. We present an analysis of the phylogenetic relationships among various representative species of five of the six genera belonging to the Pedinotus genus group based on one mitochondrial (cytochrome oxidase I) and two nuclear (28S, Wingless) gene markers. We also estimated the timing of origin and diversification within the group and investigated the external morphology of the genera involved in order to determine reliable identification characters. The group as a whole, whilst being recovered as monophyletic with the inclusion of Acanthorhogas Szépligeti, was not statistically supported. However, the respective monophyly of all of the morphologically supported genera are confirmed, as are the intergeneric relationships (Gymnobracon, Trigonophasmus) ((Acanthorhogas, Osmophila) (Lamquetia, Pedinotus)). We propose that the pattern of sublateral grooves or depressions appears to be a useful systematic character for recognition of an endemic Neotropical radiation that could have originated c. 41–27 Ma. We redescribe six of the seven genera that we recognize for the Pedinotus genus group and provide a key to enable their identification.     

Elevated atmospheric CO2 increases microbial growth rates in soil: results of three CO2 enrichment experiments

Increasing the belowground translocation of assimilated carbon by plants grown under elevated CO₂ can cause a shift in the structure and activity of the microbial community responsible for the turnover of organic matter in soil. We investigated the long‐term effect of elevated CO₂ in the atmosphere on microbial biomass and specific growth rates in root‐free and rhizosphere soil. The experiments were conducted under two free air carbon dioxide enrichment (FACE) systems: in Hohenheim and Braunschweig, as well as in the intensively managed forest mesocosm of the Biosphere 2 Laboratory (B2L) in Oracle, AZ. Specific microbial growth rates (μ) were determined using the substrate‐induced respiration response after glucose and/or yeast extract addition to the soil. For B2L and both FACE systems, up to 58% higher μ were observed under elevated vs. ambient CO₂, depending on site, plant species and N fertilization. The μ‐values increased linearly with atmospheric CO₂ concentration at all three sites. The effect of elevated CO₂ on rhizosphere microorganisms was plant dependent and increased for: Brassica napus=Triticum aestivum<Beta vulgaris<Populus deltoides. N deficiency affected microbial growth rates directly (N limitation) and indirectly (changing the quantity of fine roots). So, 50% decrease in N fertilization caused the overall increase or decrease of microbial growth rates depending on plant species. The μ‐value increase was lower for microorganisms growing on yeast extract then for those growing on glucose, i.e. the effect of elevated CO₂ was smoothed on rich vs. simple substrate. So, the r/K strategies ratio can be better revealed by studying growth on simple (glucose) than on rich substrate mixtures (yeast extract). Our results clearly showed that the functional characteristics of the soil microbial community (i.e. specific growth rates) rather than total microbial biomass amount are sensitive to increased atmospheric CO₂. We conclude that the more abundant available organics released by roots at elevated CO₂ altered the ecological strategy of the soil microbial community specifically a shift to a higher contribution of fast‐growing r‐selected species was observed. These changes in functional structure of the soil microbial community may counterbalance higher C input into the soil under elevated atmospheric CO₂ concentration.     

The Zooflagellates Stephanopogon and Percolomonas are a Clade (Class Percolatea: Phylum Percolozoa)

ABSTRACT. The enigmatic marine protozoan Stephanopogon was first classified with ciliate protozoa because its pellicle also has rows of cilia. As ciliates have nuclear dimorphism with separate germline and somatic nuclei, Stephanopogon with several identical nuclei was regarded as a model for a hypothetical homokaryotic ancestor of ciliates. When electron microscopy revealed radical differences from ciliates this idea was abandoned, but its evolutionary position remains controversial, affinities with three other phyla being suggested. We sequenced 18S rDNA from Stephanopogon aff. minuta and actin genes from it and Stephanopogon apogon to clarify their evolutionary position. Phylogenetic analyses of 18S rRNA nest S. aff. minuta and Stephanopogon minuta securely within the protozoan phylum Percolozoa with zooflagellates of the genus Percolomonas, their closest relatives, comprising the clade Percolatea. This supports a previous grouping of Stephanopogon (order Pseudociliatida) with Percolomonas (order Percolomonadida) as a purely zooflagellate class Percolatea within Percolozoa, in contrast to the fundamentally amoeboid Heterolobosea, which are probably ancestral to Percolatea. Stephanopogon actins evolve exceptionally fast: actin trees place them as a long branch within bikont eukaryotes without revealing their sisters. We establish Percolomonadidae fam. n. for Percolomonas, excluding Pharyngomonas kirbyi g., sp. n. and Pharyngomonas (=Tetramastix=Percolomonas) salina comb. n., which unlike Percolomonas have two anterior and two posterior cilia and a pocket‐like pharynx, like “Macropharyngomonas”, now grouped with Pharyngomonas as a new purely zooflagellate class Pharyngomonadea, within a new subphylum Pharyngomonada; this contrasts them with the revised ancestrally amoeboflagellate subphylum Tetramitia. We discuss evolution of the percolozoan cytoskeleton and different body forms.     

Phylogeny of the genera of the parasitic wasps subfamily Doryctinae (Hymenoptera: Braconidae) based on morphological evidence

The evolutionary relationships among most (143 genera) of the currently recognized genera of the braconid wasp subfamily Doryctinae were investigated using maximum parsimony analysis, employing 100 characters from external morphology and four additional, less well‐studied character systems (male genitalia, ovipositor structure, venom apparatus and larval cephalic structure). We investigated the ‘performance’ of characters from external morphology and the other character systems and the effects of abundant missing entries by comparing the data decisiveness, retention and consistency indices of four different character partitions. The results indicate that the performances of the different partitions are not related to the proportions of missing entries, but instead are negatively correlated to their proportion of informative characters, suggesting that the morphological information in this group is subject to high levels of homoplasy. The external morphological partition is significantly incongruent with respect to a data set comprising the other character systems based on the ILD test. Analyses supported neither the monophyly of the large tribes Doryctini and Hecabolini, nor the monophyly of the Spathiini and Heterospilini. Relationships obtained from successive approximation weighting analysis for the complete data differ considerably from the currently accepted tribal and subtribal classifications. The only exceptions were the Ypsistocerini and the Ecphylini, whose recognized members were recovered in single clades. A close relationship between the Binaerini and Holcobraconini, and also Monarea, is consistently supported by venom apparatus and ovipositor structure characters but is not indicated by external morphological data. Low bootstrap values obtained for most of the recovered clades in all analyses do not allow us to propose a meaningful reclassification for the group at this time. A complete list of the recognized genera and their synonymies is given. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society, 2004, 142 , 369–404.