The Interstellar Medium In Galaxies Seen A Billion Years After The Big Bang

Evolution in the measured rest frame ultraviolet spectral slope and ultraviolet to optical flux ratios indicate a rapid evolution in the dust obscuration of galaxies during the first 3 billion years of cosmic time (z>4). This evolution implies a change in the average interstellar medium properties, but the measurements are systematically uncertain due to untested assumptions, and the inability to measure heavily obscured regions of the galaxies. Previous attempts to directly measure the interstellar medium in normal galaxies at these redshifts have failed for a number of reasons with one notable exception. Here we report measurements of the [CII] gas and dust emission in 9 typical (~1-4L*) star-forming galaxies ~1 billon years after the big bang (z~5-6). We find these galaxies have >12x less thermal emission compared with similar systems ~2 billion years later, and enhanced [CII] emission relative to the far-infrared continuum, confirming a strong evolution in the interstellar medium properties in the early universe. The gas is distributed over scales of 1-8 kpc, and shows diverse dynamics within the sample. These results are consistent with early galaxies having significantly less dust than typical galaxies seen at z<3 and being comparable to local low-metallicity systems.Comment: Submitted to Nature, under review after referee report. 22 pages, 4 figures, 4 Extended Data Figures, 5 Extended Data table

Radiogenic backgrounds in the NEXT double beta decay experiment

Natural radioactivity represents one of the main backgrounds in the search for neutrinoless double beta decay. Within the NEXT physics program, the radioactivity- induced backgrounds are measured with the NEXT-White detector. Data from 37.9 days of low-background operations at the Laboratorio Subterráneo de Canfranc with xenon depleted in 136Xe are analyzed to derive a total background rate of (0.84±0.02) mHz above 1000 keV. The comparison of data samples with and without the use of the radon abatement system demonstrates that the contribution of airborne-Rn is negligible. A radiogenic background model is built upon the extensive radiopurity screening campaign conducted by the NEXT collaboration. A spectral fit to this model yields the specific contributions of 60Co, 40K, 214Bi and 208Tl to the total background rate, as well as their location in the detector volumes. The results are used to evaluate the impact of the radiogenic backgrounds in the double beta decay analyses, after the application of topological cuts that reduce the total rate to (0.25±0.01) mHz. Based on the best-fit background model, the NEXT-White median sensitivity to the two-neutrino double beta decay is found to be 3.5σ after 1 year of data taking. The background measurement in a Qββ±100 keV energy window validates the best-fit background model also for the neutrinoless double beta decay search with NEXT-100. Only one event is found, while the model expectation is (0.75±0.12) events. [Figure not available: see fulltext.]

Demonstration of the event identification capabilities of the NEXT-White detector

In experiments searching for neutrinoless double-beta decay, the possibility of identifying the two emitted electrons is a powerful tool in rejecting background events and therefore improving the overall sensitivity of the experiment. In this paper we present the first measurement of the efficiency of a cut based on the different event signatures of double and single electron tracks, using the data of the NEXT-White detector, the first detector of the NEXT experiment operating underground. Using a 228Th calibration source to produce signal-like and background-like events with energies near 1.6 MeV, a signal efficiency of 71.6 ± 1.5 stat± 0.3 sys% for a background acceptance of 20.6 ± 0.4 stat± 0.3 sys% is found, in good agreement with Monte Carlo simulations. An extrapolation to the energy region of the neutrinoless double beta decay by means of Monte Carlo simulations is also carried out, and the results obtained show an improvement in background rejection over those obtained at lower energies. [Figure not available: see fulltext.

Cross-sectional associations between multiple lifestyle behaviors and health-related quality of life in the 10,000 steps cohort

Background: The independent and combined influence of smoking, alcohol consumption, physical activity, diet, sitting time, and sleep duration and quality on health status is not routinely examined. This study investigates the relationships between these lifestyle behaviors, independently and in combination, and health-related quality of life (HRQOL). Methods: Adult members of the 10,000 Steps project (n = 159,699) were invited to participate in an online survey in November-December 2011. Participant socio-demographics, lifestyle behaviors, and HRQOL (poor self-rated health; frequent unhealthy days) were assessed by self-report. The combined influence of poor lifestyle behaviors were examined, independently and also as part of two lifestyle behavior indices, one excluding sleep quality (Index 1) and one including sleep quality (Index 2). Adjusted Cox proportional hazard models were used to examine relationships between lifestyle behaviors and HRQOL. Results: A total of 10,478 participants provided complete data for the current study. For Index 1, the Prevalence Ratio (p value) of poor self-rated health was 1.54 (p = 0.001), 2.07 (p≤0.001), 3.00 (p≤0.001), 3.61 (p≤0.001) and 3.89 (p≤0.001) for people reporting two, three, four, five and six poor lifestyle behaviors, compared to people with 0-1 poor lifestyle behaviors. For Index 2, the Prevalence Ratio (p value) of poor self-rated health was 2.26 (p = 0.007), 3.29 (p≤0.001), 4.68 (p≤0.001), 6.48 (p≤0.001), 7.91 (p≤0.001) and 8.55 (p≤0.001) for people reporting two, three, four, five, six and seven poor lifestyle behaviors, compared to people with 0-1 poor lifestyle behaviors. Associations between the combined lifestyle behavior index and frequent unhealthy days were statistically significant and similar to those observed for poor self-rated health. Conclusions: Engaging in a greater number of poor lifestyle behaviors was associated with a higher prevalence of poor HRQOL. This association was exacerbated when sleep quality was included in the index. © 2014 Duncan et al

Belediye Müzesi

Taha Toros Arşivi, Dosya No: 114-Müzelerİstanbul Kalkınma Ajansı (TR10/14/YEN/0033) İstanbul Development Agency (TR10/14/YEN/0033

The Gut Microbiota of Wild Mice

The gut microbiota profoundly affects the biology of its host. The composition of the microbiota is dynamic and is affected by both host genetic and many environmental effects. The gut microbiota of laboratory mice has been studied extensively, which has uncovered many of the effects that the microbiota can have. This work has also shown that the environments of different research institutions can affect the mouse microbiota. There has been relatively limited study of the microbiota of wild mice, but this has shown that it typically differs from that of laboratory mice (and that maintaining wild caught mice in the laboratory can quite quickly alter the microbiota). There is also inter-individual variation in the microbiota of wild mice, with this principally explained by geographical location. In this study we have characterised the gut (both the caecum and rectum) microbiota of wild caught Mus musculus domesticus at three UK sites and have investigated how the microbiota varies depending on host location and host characteristics. We find that the microbiota of these mice are generally consistent with those described from other wild mice. The rectal and caecal microbiotas of individual mice are generally more similar to each other, than they are to the microbiota of other individuals. We found significant differences in the diversity of the microbiotas among mice from different sample sites. There were significant correlations of microbiota diversity and body weight, a measure of age, body-mass index, serum concentration of leptin, and virus, nematode and mite infection

The transmission of Leishmania infantum chagasi by the bite of the Lutzomyia longipalpis to two different vertebrates

<p>Abstract</p> <p>Background</p> <p>Sandflies are vectors of <it>Leishmania</it>, the causative agent of leishmaniasis in mammalian hosts, including humans. The protozoan parasite is transmitted by the sandfly bite during salivation that occurs at the moment of blood feeding. The components of vector saliva include anticlotting and vasodilatory factors that facilitate blood flow and immunomodulatory factors that inhibit wound healing and quell the immune response. Not surprisingly, these factors also play important roles in the establishment of <it>Leishmania </it>infection. To date, the majority of knowledge that has been generated regarding the process of <it>Leishmania </it>infection, including <it>L. infantum chagasi </it>transmission has been gathered by using intradermal or subcutaneous inoculation of purified parasites.</p> <p>Findings</p> <p>This study presents the establishment of a transmission model of <it>Leishmania infantum chagasi </it>by the bite of <it>Lutzomyia longipalpis</it>, the vector of American visceral leishmaniasis. The parasites were successfully transmitted by infected sandfly bites to mice and hamsters, indicating that both animals are good experimental models. The <it>L. infantum chagasi </it>dose that was transmitted in each single bite ranged from 10 to 10, 000 parasites, but 75% of the sandflies transmitted less than 300 parasites.</p> <p>Conclusions</p> <p>The strategy for initiating infection by sandfly bite of experimental animals facilitates future investigations into the complex and dynamic mechanisms of visceral leishmaniasis. It is important to elucidate the transmission mechanism of vector bites. This model represents a useful tool to study <it>L. infantum chagasi </it>infection transmitted by the vector.</p

The case for home monitoring in hypertension

Although the assessment of cardiovascular risk in individual patients takes into account a range of risk factors, the diagnosis and management of hypertension (high blood pressure) is largely determined by a single numerical value, albeit that often several readings are taken over time. Given the critical impact of a decision to embark on lifelong drug therapy, the importance of ensuring that a blood pressure (BP) record is both accurate and representative is clear. However, there is good evidence that the variability of BP is such that even if measurement is of the highest quality, it can be difficult to say with confidence whether a patient is above or below a treatment threshold. This commentary argues that current BP measurement is inadequate to make the clinical decisions that are necessary and that multiple readings are required to deliver an acceptable degree of accuracy for safe decision-making. This is impractical in a doctor's surgery, and the only realistic long-term strategy is to involve the patient in measuring his or her own BP in their own environment. Evidence is presented that such a strategy is better able to predict risk, is cost-effective for diagnosing hypertension, can improve BP control and is thus better able to protect individuals in the future

Sub-microscopic malaria cases and mixed malaria infection in a remote area of high malaria endemicity in Rattanakiri province, Cambodia: implication for malaria elimination

BACKGROUND: Malaria microscopy and rapid diagnostic tests are insensitive for very low-density parasitaemia. This insensitivity may lead to missed asymptomatic sub-microscopic parasitaemia, a potential reservoir for infection. Similarly, mixed infections and interactions between Plasmodium species may be missed. The objectives were first to develop a rapid and sensitive PCR-based diagnostic method to detect low parasitaemia and mixed infections, and then to investigate the epidemiological importance of sub-microscopic and mixed infections in Rattanakiri Province, Cambodia. METHODS: A new malaria diagnostic method, using restriction fragment length polymorphism analysis of the cytochrome b genes of the four human Plasmodium species and denaturing high performance liquid chromatography, has been developed. The results of this RFLP-dHPLC method have been compared to 1) traditional nested PCR amplification of the 18S rRNA gene, 2) sequencing of the amplified fragments of the cytochrome b gene and 3) microscopy. Blood spots on filter paper and Giemsa-stained blood thick smears collected in 2001 from 1,356 inhabitants of eight villages of Rattanakiri Province have been analysed by the RFLP-dHPLC method and microscopy to assess the prevalence of sub-microscopic and mixed infections. RESULTS: The sensitivity and specificity of the new RFLP-dHPLC was similar to that of the other molecular methods. The RFLP-dHPLC method was more sensitive and specific than microscopy, particularly for detecting low-level parasitaemia and mixed infections. In Rattanakiri Province, the prevalences of Plasmodium falciparum and Plasmodium vivax were approximately two-fold and three-fold higher, respectively, by RFLP-dHPLC (59% and 15%, respectively) than by microscopy (28% and 5%, respectively). In addition, Plasmodium ovale and Plasmodium malariae were never detected by microscopy, while they were detected by RFLP-dHPLC, in 11.2% and 1.3% of the blood samples, respectively. Moreover, the proportion of mixed infections detected by RFLP-dHPLC was higher (23%) than with microscopy (8%). CONCLUSIONS: The rapid and sensitive molecular diagnosis method developed here could be considered for mass screening and ACT treatment of inhabitants of low-endemicity areas of Southeast Asia