Large-scale air mass characteristics observed over the remote tropical Pacific Ocean during March-April 1999: Results from PEM-Tropics B field experiment

Eighteen long-range flights over the Pacific Ocean between 38° S to 20° N and 166° E to 90° W were made by the NASA DC-8 aircraft during the NASA Pacific Exploratory Mission (PEM) Tropics B conducted from March 6 to April 18, 1999. Two lidar systems were flown on the DC-8 to remotely measure vertical profiles of ozone (O3), water vapor (H2O), aerosols, and clouds from near the surface to the upper troposphere along their flight track. In situ measurements of a wide range of gases and aerosols were made on the DC-8 for comprehensive characterization of the air and for correlation with the lidar remote measurements. The transition from northeasterly flow of Northern Hemispheric (NH) air on the northern side of the Intertropical Convergence Zone (ITCZ) to generally easterly flow of Southern Hemispheric (SH) air south of the ITCZ was accompanied by a significant decrease in O3, carbon monoxide, hydrocarbons, and aerosols and an increase in H2O. Trajectory analyses indicate that air north of the ITCZ came from Asia and/or the United States, while the air south of the ITCZ had a long residence time over the Pacific, perhaps originating over South America several weeks earlier. Air south of the South Pacific Convergence Zone (SPCZ) came rapidly from the west originating over Australia or Africa. This air had enhanced O3 and aerosols and an associated decrease in H2O. Average latitudinal and longitudinal distributions of O3 and H2O were constructed from the remote and in situ O3 and H2O data, and these distributions are compared with results from PEM-Tropics A conducted in August-October 1996. During PEM-Tropics B, low O3 air was found in the SH across the entire Pacific Basin at low latitudes. This was in strong contrast to the photochemically enhanced O3 levels found across the central and eastern Pacific low latitudes during PEM-Tropics A. Nine air mass types were identified for PEM-Tropics B based on their O3, aerosols, clouds, and potential vorticity characteristics. The data from each flight were binned by altitude according to air mass type, and these results showed the relative observational frequency of the different air masses as a function of altitude in seven regions over the Pacific. The average chemical composition of the major air mass types was determined from in situ measurements in the NH and SH, and these results provided insight into the origin, lifetime, and chemistry of the air in these regions. Copyright 2001 by the American Geophysical Union

Literature

Literature has been proposed as a means to enrich an understanding of ethical issues within medicine and health care and as a resource in medical education. Its proponents argue for the value of understanding human suffering, and the experience of health care, through literature, rather than solely through the more abstract and analytic philosophical methods of bioethics. Literature is claimed to serve as a corrective to the rational and individualist approaches of bioethics, by drawing attention to ‘our vulnerable and interdependent human existence.’ In this essay the history of a relationship between ethics and literature is discussed, along with more recent scholarship on the ethical relevance of literature, and research focusing on the constitution of ethics as literary form. It is apparent that literature, and especially futurist writing and science fiction, has an influence on the construction and understanding of ethical issues for both specialist practitioners and the lay public. It is concluded that literature enhances understanding of ethical issues in health care and research, and the manner in which it does so needs to be better understood through the skills of literary analysis as a necessary complement to bioethical analysis

Tumor-derived exosomes confer antigen-specific immunosuppression in a murine delayed-type hypersensitivity model

Exosomes are endosome-derived small membrane vesicles that are secreted by most cell types including tumor cells. Tumor-derived exosomes usually contain tumor antigens and have been used as a source of tumor antigens to stimulate anti-tumor immune responses. However, many reports also suggest that tumor-derived exosomes can facilitate tumor immune evasion through different mechanisms, most of which are antigen-independent. In the present study we used a mouse model of delayed-type hypersensitivity (DTH) and demonstrated that local administration of tumor-derived exosomes carrying the model antigen chicken ovalbumin (OVA) resulted in the suppression of DTH response in an antigen-specific manner. Analysis of exosome trafficking demonstrated that following local injection, tumor-derived exosomes were internalized by CD11c+ cells and transported to the draining LN. Exosome-mediated DTH suppression is associated with increased mRNA levels of TGF-β1 and IL-4 in the draining LN. The tumor-derived exosomes examined were also found to inhibit DC maturation. Taken together, our results suggest a role for tumor-derived exosomes in inducing tumor antigen-specific immunosuppression, possibly by modulating the function of APCs. © 2011 Yang et al

Mitochondrial phylogeography and demographic history of the Vicuña: implications for conservation

The vicuña (Vicugna vicugna; Miller, 1924) is a conservation success story, having recovered from near extinction in the 1960s to current population levels estimated at 275 000. However, lack of information about its demographic history and genetic diversity has limited both our understanding of its recovery and the development of science-based conservation measures. To examine the evolution and recent demographic history of the vicuña across its current range and to assess its genetic variation and population structure, we sequenced mitochondrial DNA from the control region (CR) for 261 individuals from 29 populations across Peru, Chile and Argentina. Our results suggest that populations currently designated as Vicugna vicugna vicugna and Vicugna vicugna mensalis comprise separate mitochondrial lineages. The current population distribution appears to be the result of a recent demographic expansion associated with the last major glacial event of the Pleistocene in the northern (18 to 22°S) dry Andes 14–12 000 years ago and the establishment of an extremely arid belt known as the 'Dry Diagonal' to 29°S. Within the Dry Diagonal, small populations of V. v. vicugna appear to have survived showing the genetic signature of demographic isolation, whereas to the north V. v. mensalis populations underwent a rapid demographic expansion before recent anthropogenic impacts

Site and Strain-Specific Variation in Gut Microbiota Profiles and Metabolism in Experimental Mice

The gastrointestinal tract microbiota (GTM) of mammals is a complex microbial consortium, the composition and activities of which influences mucosal development, immunity, nutrition and drug metabolism. It remains unclear whether the composition of the dominant GTM is conserved within animals of the same strain and whether stable GTMs are selected for by host-specific factors or dictated by environmental variables.The GTM composition of six highly inbred, genetically distinct strains of mouse (C3H, C57, GFEC, CD1, CBA nu/nu and SCID) was profiled using eubacterial -specific PCR-DGGE and quantitative PCR of feces. Animals exhibited strain-specific fecal eubacterial profiles that were highly stable (c. >95% concordance over 26 months for C57). Analyses of mice that had been relocated before and after maturity indicated marked, reproducible changes in fecal consortia and that occurred only in young animals. Implantation of a female BDF1 mouse with genetically distinct (C57 and Agoutie) embryos produced highly similar GTM profiles (c. 95% concordance) between mother and offspring, regardless of offspring strain, which was also reflected in urinary metabolite profiles. Marked institution-specific GTM profiles were apparent in C3H mice raised in two different research institutions.Strain-specific data were suggestive of genetic determination of the composition and activities of intestinal symbiotic consortia. However, relocation studies and uterine implantation demonstrated the dominance of environmental influences on the GTM. This was manifested in large variations between isogenic adult mice reared in different research institutions

Ovarian cancer histology-specific incidence trends in Canada 1969–1993: age-period-cohort analyses

This study examined histology-specific incidence trends of ovarian cancer in Canada, 1969–1993. The impact of age, period and cohort effects on these trends were studied by means of age-period-cohort analysis. Age-standardized incidence rates of serous, endometrioid, clear cell and germ cell tumours increased significantly and the rates of sex cord-stromal and other classified epithelial ovarian tumours decreased considerably. The rates of mucinous and NOS/unclassified tumours remained unchanged. Cohort effect has a major impact on incidence trends of serous, endometrioid, germ cell, sex cord-stromal and other classified epithelial ovarian tumours but no meaningful impact on trends of mucinous, clear cell, or NOS/unclassified ovarian tumours. Various cohort patterns by histology subtypes were observed: the risk of developing serious tumours increased markedly among birth cohorts of 1895–1930, stabilized thereafter and decreased among young cohorts of 1950–1960; the risk of germ cell tumours increased significantly among young cohorts of 1965–1980; and the risk of sex cord-stromal tumours dropped constantly among cohorts 1910–1950. Various period patterns by histology subtypes observed in this study suggested changes in histology classification criteria over the period. Further studies need to consider the various etiologies and the classification criteria changes according to histology subtypes. © 1999 Cancer Research Campaig

The effect of posterior capsule repair upon post-operative hip dislocation following primary total hip arthroplasty

<p>Abstract</p> <p>Background</p> <p>Herein, we evaluated, retrospectively, the effect of posterior capsular repair upon postoperative hip dislocation subsequent to total hip arthroplasty (THA) incorporating a posterolateral approach.</p> <p>Methods</p> <p>A total of 181 patients undergoing 204 primary non-complicated THA surgical procedures in the period from January 2000 to October 2005 inclusively were included in this study. The patients were separated into two groups by whether the posterior capsular repair had been incorporated in the surgical procedure. For the surgeon did not commence repairing the posterior capsule until July, 2003, all members in the group that did not undergo posterior capsular repair (142 hips from 131 patients) were collected since January, 2000 to July, 2003, while the members in the group that underwent posterior capsular repair (62 hips from 52 patients) were followed since July, 2003, to October, 2005. With a minimum follow-up period of 12 months, we evaluated the early post-operative dislocation rate.</p> <p>Results</p> <p>The early postoperative hip-dislocation rate for the group who did not undergo posterior capsular repair appeared to be substantially greater (6.38% versus 0%) than the corresponding figure for the group the members of which underwent posterior capsular repair. In addition, patient demographics and the orientation of acetabular components for the replaced hip joints, as presented in postoperative radiographs, did not differ between the two groups.</p> <p>Conclusion</p> <p>Thus, surgeons should include posterior capsular repair as an important step in the surgical procedures of posterolateral approach for all THA in order to reduce the likelihood of early hip dislocation subsequent to THA.</p

Group art therapy as an adjunctive treatment for people with schizophrenia: multicentre pragmatic randomised trial

Objectives To evaluate the clinical effectiveness of group art therapy for people with schizophrenia and to test whether any benefits exceed those of an active control treatment

Phylotyping and Functional Analysis of Two Ancient Human Microbiomes

Background: The Human Microbiome Project (HMP) is one of the U.S. National Institutes of Health Roadmap for Medical Research. Primary interests of the HMP include the distinctiveness of different gut microbiomes, the factors influencing microbiome diversity, and the functional redundancies of the members of human microbiotas. In this present work, we contribute to these interests by characterizing two extinct human microbiotas. Methodology/Principal Findings: We examine two paleofecal samples originating from cave deposits in Durango Mexico and dating to approximately 1300 years ago. Contamination control is a serious issue in ancient DNA research; we use a novel approach to control contamination. After we determined that each sample originated from a different human, we generated 45 thousand shotgun DNA sequencing reads. The phylotyping and functional analysis of these reads reveals a signature consistent with the modern gut ecology. Interestingly, inter-individual variability for phenotypes but not functional pathways was observed. The two ancient samples have more similar functional profiles to each other than to a recently published profile for modern humans. This similarity could not be explained by a chance sampling of the databases. Conclusions/Significance: We conduct a phylotyping and functional analysis of ancient human microbiomes, while providing novel methods to control for DNA contamination and novel hypotheses about past microbiome biogeography. We postulate that natural selection has more of an influence on microbiome functional profiles than it does on the species represented in the microbial ecology. We propose that human microbiomes were more geographically structured during pre-Columbian times than today