Morphology, physiology, biochemistry and functional design of the termite gut: an evolutionary wonderland

The chapter reviews termite gut structure and associations with mutualists, now informed by a great increase of data on intestinal microbial diversity made possible in the last decade by molecular genomics, and in the light of contemporary theories on the origin, evolution and trophic diversification of the Isoptera. Detailed morphological descriptions are not given, but the more modern synoptic literature on anatomy, histology and in situ coiling is listed and discussed in relation to current concepts of the termite gut as a bioreactor system. Knowledge of intestinal microbiology, and of microbial physiology and metabolism, has outstripped progress in understanding secretory and absorptive processes by the gut wall and associated structures, such that the primary substrates fermented in the hindgut and the end products utilised by the termite host are still not precisely identified in many cases. Current perceptions of the specialised digestive processes of fungus-growing and soil-feeding termites are summarised, and an overarching evolutionary thesis is proposed, arguing that social organisation in termites has developed primarily to safeguard the fidelity of symbiont transmission between individuals and generations

Impaired interferon-γ responses, increased interleukin-17 expression, and a tumor necrosis factor–α transcriptional program in invasive aspergillosis

This article is available open access through the publisher’s website. Copyright @ 2009 Oxford University Press.Background - Invasive aspergillosis (IA) is the most common cause of death associated with fungal infection in the developed world. Historically, susceptibility to IA has been associated with prolonged neutropenia; however, IA has now become a major problem in patients on calcineurin inhibitors and allogenic hematopoetic stem cell transplant patients following engraftment. These observations suggest complex cellular mechanisms govern immunity to IA. Methods - To characterize the key early events that govern outcome from infection with Aspergillus fumigatus we performed a comparative immunochip microarray analysis of the pulmonary transcriptional response to IA between cyclophosphamide-treated mice and immunocompetent mice at 24 h after infection. Results - We demonstrate that death due to infection is associated with a failure to generate an incremental interferon-γ response, increased levels of interleukin-5 and interleukin-17a transcript, coordinated expression of a network of tumor necrosis factor–α-related genes, and increased levels of tumor necrosis factor–α. In contrast, clearance of infection is associated with increased expression of a number genes encoding proteins involved in innate pathogen clearance, as well as apoptosis and control of inflammation. Conclusion - This first organ-level immune response transcriptional analysis for IA has enabled us to gain new insights into the mechanisms that govern fungal immunity in the lung.The BBSRC, CGD Research Trust, and the MRC

Further Observational Evidence for a Critical Ionising Luminosity in Active Galaxies

We report the results of a survey for HI 21-cm absorption at redshifts of z > 2.6 in a new sample of radio sources with the Green Bank and Giant Metrewave Radio Telescopes. From a total of 25 targets, we report zero detections in the 16 for which optical depth limits could be obtained. Based upon the detection rate for z > 0.1 associated absorption, we would expect approximately four detections. Of the 11 which have previously not been searched, there is sufficient source-frame optical/ultra-violet photometry to determine the ionising photon rate for four. Adding these to the literature, the hypothesis that there is a critical rate of logQ = 56 ionising photons per second is now significant at ~7 sigma. This reaffirms our assertion that searching z > 3 active galaxies for which optical redshifts are available selects sources in which the ultra-violet luminosity is sufficient to ionise all of the neutral gas in the host galaxy.Comment: Accepted by MNRA

Impact of education and training on type of care provided by community-based breastfeeding counselors: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Studies using community-based breastfeeding counselors (CBBCs) have repeatedly shown positive impact on breastfeeding initiation, exclusivity and duration, particularly among low-income mothers. To date, there has not been a comprehensive study to determine the impact of CBBC attributes such as educational background and training, on the type of care that CBBCs provide.</p> <p>Methods</p> <p>This was a cross-sectional study of a convenience sample of CBBCs to ascertain the influence of counselor education and type of training on type of support and proficiency of CBBCs in communities across the United States. Invitations to participate in this online survey of CBBCs were e-mailed to program coordinators of the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), La Leche League, and other community-based health organizations, who in turn invited and encouraged their CBBCs to participate. Descriptive analysis was used to describe participants (N = 847), while bivariate analysis using χ²test was used to examine the differences between CBBC education, training received and breastfeeding support skills used. Multivariate logistic regression was used to assess the independent determinants of specific breastfeeding support skills.</p> <p>Results</p> <p>The major findings from the research indicate that overall, educational attainment of CBBCs is not a significant predictor for the curriculum used in their training and type of support skills used during counseling sessions, but initial training duration was positively associated with the use of many breastfeeding support skills. Another major influence of counselor support to clients is the type of continuing education they receive after their initial training, with higher likelihood of use of desirable support skills associated with counselors continuing their breastfeeding education at conferences or trainings away from their job sites.</p> <p>Conclusions</p> <p>Our results show that different programs use different training curricula to train their CBBCs varying in duration and content. Counselor education is not a significant predictor of the type of training they receive. Continuing breastfeeding education is a significant determinant of type of counseling techniques used with clients. Further research is therefore needed to critically examine the content of the various training curricula of CBBC programs. This may show a need for a standardized training curriculum for all CBBC programs worldwide to make CBBCs more proficient and efficient, ensuring successful and optimum breastfeeding experiences for mothers and their newborns.</p

Fractal-like Distributions over the Rational Numbers in High-throughput Biological and Clinical Data

Recent developments in extracting and processing biological and clinical data are allowing quantitative approaches to studying living systems. High-throughput sequencing, expression profiles, proteomics, and electronic health records are some examples of such technologies. Extracting meaningful information from those technologies requires careful analysis of the large volumes of data they produce. In this note, we present a set of distributions that commonly appear in the analysis of such data. These distributions present some interesting features: they are discontinuous in the rational numbers, but continuous in the irrational numbers, and possess a certain self-similar (fractal-like) structure. The first set of examples which we present here are drawn from a high-throughput sequencing experiment. Here, the self-similar distributions appear as part of the evaluation of the error rate of the sequencing technology and the identification of tumorogenic genomic alterations. The other examples are obtained from risk factor evaluation and analysis of relative disease prevalence and co-mordbidity as these appear in electronic clinical data. The distributions are also relevant to identification of subclonal populations in tumors and the study of the evolution of infectious diseases, and more precisely the study of quasi-species and intrahost diversity of viral populations

A gene to organism approach--assessing the impact of environmental pollution in eelpout (Zoarces viviparus) females and larvae

A broad biomarker approach was applied to study the effects of marine pollution along the Swedish west coast using the teleost eelpout (Zoarces viviparus) as the sentinel species. Measurements were performed on different biological levels, from the molecular to the organismal, including measurements of messenger RNA (mRNA), proteins, cellular and tissue changes, and reproductive success. Results revealed that eelpout captured in Stenungsund had significantly higher hepatic ethoxyresorufin O-deethylase activity, high levels of both cytochrome P4501A and diablo homolog mRNA, and high prevalence of dead larvae and nuclear damage in erythrocytes. Eelpout collected in Göteborg harbor displayed extensive macrovesicular steatosis, whereby the majority of hepatocytes were affected throughout the liver, which could indicate an effect on lipid metabolism. Results also indicate that eelpouts collected at polluted sites might have an affected immune system, with lower mRNA expression of genes involved in the innate immune system and a higher number of lymphocytes. Biomarker assessment also was performed on livers dissected from unborn eelpout larvae collected from the ovary of the females. No significant differences were noted, which might indicate that the larvae to some extent are protected from effects of environmental pollutants. In conclusion, usage of the selected set of biological markers, covering responses from gene to organism, has demonstrated site-specific biomarker patterns that provided a broad and comprehensive picture of the impact of environmental stressors