To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Nucleobases are nitrogenous bases composed of monomers that are a major constituent of RNA and DNA, which are an essential part of any cellular life on the Earth. The search for nucleobases in the interstellar medium remains a major challenge, however, the recent detection of nucleobases in meteorite samples and laboratory synthesis in simulated analogue experiments have confirmed their abiotic origin and a possible route for their delivery to the Earth. Nevertheless, cellular life is based on the interacting network of complex structures, and there is substantial lack of information on the possible routes by which such ordered structures may be formed in the prebiotic environment. In the current study, we present the evidence for the synthesis of complex structures due to shock processing of nucleobases. The nucleobases were subjected to the reflected shock temperature of 3500–7000 K (estimated) and pressure of about 15–34 bar for over ~2 ms timescale. Under such extreme thermodynamic conditions, the nucleobases sample experiences superheating and subsequent cooling. Electron microscopic studies of shock processed residue show that nucleobases result in spontaneous formation of complex structures when subjected to extreme conditions of shock. These results suggest that impact shock processes might have contributed to the self-assembly of biologically relevant structures and the origin of life.
Nonsuicidal self-injury (NSSI) is prevalent among adolescents and research is needed to clarify the mechanisms which contribute to the behavior. Here, the authors relate behavioral neurocognitive measures of impulsivity and compulsivity to repetitive and sporadic NSSI in a community sample of adolescents.
Computerized laboratory tasks (Affective Go/No-Go, Cambridge Gambling Task, and Probabilistic Reversal Task) were used to evaluate cognitive performance. Participants were adolescents aged 15 to 17 with (n = 50) and without (n = 190) NSSI history, sampled from the ROOTS project which recruited adolescents from secondary schools in Cambridgeshire, UK. NSSI was categorized as sporadic (1-3 instances per year) or repetitive (4 or more instances per year). Analyses were carried out in a series of linear and negative binomial regressions, controlling for age, gender, intelligence, and recent depressive symptoms.
Adolescents with lifetime NSSI, and repetitive NSSI specifically, made significantly more perseverative errors on the Probabilistic Reversal Task and exhibited significantly lower quality of decision making on the Cambridge Gambling Task compared to no-NSSI controls. Those with sporadic NSSI did not significantly differ from no-NSSI controls on task performance. NSSI was not associated with behavioral measures of impulsivity.
Repetitive NSSI is associated with increased behavioral compulsivity and disadvantageous decision making, but not with behavioral impulsivity. Future research should continue to investigate how neurocognitive phenotypes contribute to the onset and maintenance of NSSI, and determine whether compulsivity and addictive features of NSSI are potential targets for treatment.
A cross-sectional study on six dairy farms was conducted to ascertain the occurrence of carbapenem-resistant Escherichia coli in calves. Two-hundred and seventy-nine isolates of E. coli were recovered from 90 faecal samples from apparently healthy (45) and diarrhoeal (45) calves. The isolates were screened for phenotypic susceptibility to carbapenems and production of metallo β-lactamase, as well as five carbapenemase resistance genes by PCR, and overexpression of efflux pumps. Eighty-one isolates (29.03%) were resistant to at least one of three carbapenem antibiotics [meropenem (23.30%), imipenem (2.15%) and ertapenem (1.43%)], and one isolate was positive for the blaVIM gene which was located on an Incl1 plasmid of a novel sequence type (ST 297) by multilocus sequence typing. The majority (83.95%) of isolates had an active efflux pump. Calves housed on concrete floors were approximately seven times more likely to acquire meropenem-resistant isolates than those housed on earthen floors (95% CI 1.27–41.54). In India, carbapenem drugs are not used in food animal treatment, hence carbapenem-resistant strains in calves possibly originate from the natural environment or human contact and is of public health importance. To our knowledge, this is the first report of blaVIM carbapenemases gene in calves from India.
We provide the first in situ measurements of antenna element beam shapes of the Murchison Widefield Array. Most current processing pipelines use an assumed beam shape, which can cause absolute and relative flux density errors and polarisation ‘leakage’. Understanding the primary beam is then of paramount importance, especially for sensitive experiments such as a measurement of the 21-cm line from the epoch of reionisation, where the calibration requirements are so extreme that tile to tile beam variations may affect our ability to make a detection. Measuring the primary beam shape from visibilities is challenging, as multiple instrumental, atmospheric, and astrophysical factors contribute to uncertainties in the data. Building on the methods of Neben et al. [Radio Sci., 50, 614], we tap directly into the receiving elements of the telescope before any digitisation or correlation of the signal. Using ORBCOMM satellite passes we are able to produce all-sky maps for four separate tiles in the XX polarisation. We find good agreement with the beam model of Sokolowski et al. [2017, PASA, 34, e062], and clearly observe the effects of a missing dipole from a tile in one of our beam maps. We end by motivating and outlining additional on-site experiments.
The deep subsurface of other planetary bodies is of special interest for robotic and human exploration. The subsurface provides access to planetary interior processes, thus yielding insights into planetary formation and evolution. On Mars, the subsurface might harbour the most habitable conditions. In the context of human exploration, the subsurface can provide refugia for habitation from extreme surface conditions. We describe the fifth Mine Analogue Research (MINAR 5) programme at 1 km depth in the Boulby Mine, UK in collaboration with Spaceward Bound NASA and the Kalam Centre, India, to test instruments and methods for the robotic and human exploration of deep environments on the Moon and Mars. The geological context in Permian evaporites provides an analogue to evaporitic materials on other planetary bodies such as Mars. A wide range of sample acquisition instruments (NASA drills, Small Planetary Impulse Tool (SPLIT) robotic hammer, universal sampling bags), analytical instruments (Raman spectroscopy, Close-Up Imager, Minion DNA sequencing technology, methane stable isotope analysis, biomolecule and metabolic life detection instruments) and environmental monitoring equipment (passive air particle sampler, particle detectors and environmental monitoring equipment) was deployed in an integrated campaign. Investigations included studying the geochemical signatures of chloride and sulphate evaporitic minerals, testing methods for life detection and planetary protection around human-tended operations, and investigations on the radiation environment of the deep subsurface. The MINAR analogue activity occurs in an active mine, showing how the development of space exploration technology can be used to contribute to addressing immediate Earth-based challenges. During the campaign, in collaboration with European Space Agency (ESA), MINAR was used for astronaut familiarization with future exploration tools and techniques. The campaign was used to develop primary and secondary school and primary to secondary transition curriculum materials on-site during the campaign which was focused on a classroom extra vehicular activity simulation.
Suicide risk reduction is crucial for 15–29-year-old youth, who account for 46% of suicide deaths in low- and middle-income countries. Suicide predictors in high-resource settings, specifically depression, do not adequately predict suicidality in these settings. We explored if interpersonal violence (IPV) was associated with suicidality, independent of depression, in Nepal.
A longitudinal cohort of child soldiers and matched civilian children, enrolled in 2007 after the People's War in Nepal, were re-interviewed in 2012. The Depression Self-Rating Scale and Composite International Diagnostic Interview assessed depression and suicidality, respectively. Non-verbal response cards were used to capture experiences of sexual and physical IPV.
One of five participants (19%) reported any lifetime suicidal ideation, which was associated with sexual IPV, female gender, former child soldier status and lack of support from teachers. Among young men, the relationship between sexual IPV and suicidality was explained by depression, and teacher support reduced suicidality. Among young women, sexual IPV was associated with suicidality, independent of depression; child soldier status increased suicidality, and teacher support decreased suicidality. Suicide plans were associated with sexual IPV but not with depression. One of 11 female former child soldiers (9%) had attempted suicide.
Sexual IPV is associated with suicidal ideation and plans among conflict-affected young women, independent of depression. Reducing suicide risk among women should include screening, care, and prevention programs for sexual IPV. Programs involving teachers may be particularly impactful for reducing suicidality among IPV survivors.
This poster presented results from a detailed analysis of observed and theoretical light-curves of classical Cepheid variables in the Galaxy and the Magellanic Clouds. The theoretical light-curves were based on non-linear convective hydrodynamical pulsation models; the observational data were taken from ongoing wide-field variability surveys. The variation which we found in theoretical and observed light-curve parameters as a function of period, wavelength and metallicity was used to constrain the input physics to the pulsation models, such as the mass–luminosity relations obeyed by Cepheid variables. We also accounted for the variation in the convective efficiency as entered into the stellar pulsation models and its impact on the theoretical amplitudes and Period-Luminosity relations for Cepheid variables.
This poster presented results from the Large Magellanic Cloud Near-Infrared Synoptic Survey (LMCNISS) for classical and Type II Cepheid variables that were identified in the Optical Gravitational Lensing Experiment (OGLE-III) catalogue. Multi-wavelength time-series data for classical Cepheid variables are used to study light-curve structures as a function of period and wavelength. We exploited a sample of ∼1400 classical and ∼80 Type II Cepheid variables to derive Period–Wesenheit relations that combine both optical and near-infrared data. The new Period–Luminosity and Wesenheit relations were used to estimate distances to several Local-Group galaxies (using classical Cepheids) and to Galactic globular clusters (using Type II Cepheids). By appealing to a statistical framework, we found that fundamental-mode classical Cepheid Period–Luminosity relations are non-linear around 10–18 days at optical and near-IR wavelengths. We also suggested that a non-linear relation provides a better constraint on the Cepheid Period–Luminosity relation in Type Ia Supernovæ host galaxies, though it has a negligible effect on the systematic uncertainties affecting the local measurement of the Hubble constant.
Classical Cepheids (hereafter Cepheids) are important standard candle as they obey the famous period-luminosity (PL) relation. Parallax measurements from Gaia offer a unique opportunity to derive or calibrate the PL relations for Galactic Cepheids, as traditionally their distances were measured via different methods. In this work, we attempted to derive the Gaia G-band PL relation based on the Gaia Data Release 1 (DR1) measurements. We adopted the inferred distances provided by Astraatmadja & Bailer-Jones (2016), calculated using two priors in a Bayesian analysis, and cross-matched to known Galactic Cepheids. The resulting G-band PL relation, however, exhibits a much larger scatter than expected. Hence the inferred distances based on the Gaia DR1 parallaxes are not suitable for calibrating the Galactic PL relation, and future Data Releases with improved parallax measurements are desirable.
Task-sharing is the involvement of non-specialist providers to deliver mental health services. A challenge for task-sharing programs is to achieve and maintain clinical competence of non-specialists, including primary care workers, paraprofessionals, and lay providers. We developed a tool for non-specialist peer ratings of common factors clinical competency to evaluate and optimize competence during training and supervision in global mental health task-sharing initiatives.
The 18-item ENhancing Assessment of Common Therapeutic factors (ENACT) tool was pilot-tested with non-specialists participating in mental health Gap Action Programme trainings in Nepal. Qualitative process evaluation was used to document development of the peer rating scoring system. Qualitative data included interviews with trainers and raters as well as transcripts of pre- and post-training observed structured clinical evaluations.
Five challenges for non-specialist peer ratings were identified through the process evaluation: (1) balance of training and supervision objectives with research objectives; (2) burden for peer raters due to number of scale items, number of response options, and use of behavioral counts; (3) capturing hierarchy of clinical skills; (4) objective v. subjective aspects of rating; and (5) social desirability when rating peers.
The process culminated in five recommendations based on the key findings for the development of scales to be used by non-specialists for peer ratings in low-resource settings. Further research is needed to determine the ability of ENACT to capture the relationship of clinical competence with client outcomes and to explore the relevance of these recommendations for non-specialist peer ratings in high-resource settings.
Populations of the six equine breeds registered by the Indian National Bureau of Animal Genetic Resources have drastically decreased due to indiscriminate breeding and their low utilization. In this study, 15 biometric indices along with typical breed characteristics were recorded for 50 animals of each breed except Bhutia breed (35) for their phenotypic characterization. On the basis of their heights at wither, Kathiawari and Marwari breeds were grouped under “horse”, while Zanskari, Manipuri, Bhutia and Spiti fell under “pony” breeds. Marwari was the tallest and significantly different from other breeds in most of the biometric indices. Spiti was the shortest breed among all the six horse and pony breeds. Sex-wise differences were also observed in some of the biometric indices in different breeds. In Marwari and Kathiawari breeds, both stallions and mares can rotate their ears at an angle of 180° making the ear tips meet in the centre, which is a typical characteristic of the two breeds. This report aims at providing reference data for identification and comparison of different breeds of equines in India with a view to raise awareness among animal geneticists and breeders for production of true to breed animals, conservation and better management of these precious genetic resources.
The current trends in stimulated Brillouin scattering and optical phase conjugation are overviewed. This report is formed by the selected papers presented in the “Fifth International Workshop on stimulated Brillouin scattering and phase conjugation 2010” in Japan. The nonlinear properties of phase conjugation based on stimulated Brillouin scattering and photo-refraction can compensate phase distortions in the high power laser systems, and they will also open up potentially novel laser technologies, e.g., phase stabilization, beam combination, pulse compression, ultrafast pulse shaping, and arbitrary waveform generation.
The very intense radiation environment of high luminosity future colliding beam
experiments (LHC, etc.) makes radiation hardness the most important issue for Si
detectors. The crucial question is whether the Si strip detectors can withstand the harsh
radiation environment for sufficiently long time (full LHC lifetime) and hence the central
issue concerning all LHC experiments is the breakdown performance of these detectors.
In this paper the simulations have been performed to analyze electrical parameters for the
most deleterious long-term effect of radiation: the change in effective charge carrier
concentration and resulting increase in full depletion bias. Detailed calculations using
Hamburg Model have allowed the parameterization of these effects, and helped to
simulate the operation scenario of Si detectors over 10 years of LHC operation. The
systematic studies of the electric field to get an insight into the device behavior provide,
for the first time, a possible explanation for the improvement in breakdown performance
with radiation. Simulation study is also carried on optimized guard ring structures to
study the change in guard voltage distribution after 10 years of neutron radiation damage.
Dengue fever (DF) or dengue haemorrhagic fever (DHF) has not previously been reported in
Coimbatore and Erode districts in Tamil Nadu in India. In 1998, 20 hospitalized cases of fever
tested positive for dengue virus IgM and/or IgG antibodies. All of them had dengue-compatible illness, and at least four had DHF. Two of them died. Sixteen cases were below
10 years of age. The cases were scattered in 15 distantly located villages and 5 urban localities
that had a high Aedes aegypti population. Although the incidence of dengue-like illness has
not increased recently, almost 89% (95/107) of samples from healthy persons in the
community tested positive for dengue IgG antibodies. The study showed that dengue has been
endemic in the area, but was not suspected earlier. A strong laboratory-based surveillance
system is essential to monitor and control DF/DHF.
Nearly all metals form a passivation film due to oxidation in air at ambient temperatures, that acts as a diffusion barrier to protect the materials from further corrosion. Aluminum demonstrates excellent passivation behavior due to the formation of a protective amorphous alumina film during exposure to air at ambient temperatures. However, H. Ebinger and J. Yates discovered that the passivation of aluminum can be significantly improved by artificial oxidation. Both electron-beam induced oxidation in water vapor and oxidation in ozone atmospheres3 showed higher impedance in electrochemical impedance spectroscopy measurements to anion diffusion than the thermally grown oxides. To understand the nature of this beneficial passivation, we probed the microstructure of these amorphous oxide films by transmission electron microscopy (TEM).
The oxide films were grown on a polycrystalline Al substrate. The Al substrate was cleaned with a sputter cleaner inside a UHV (ultra-high vacuum) system.
In high-density fluorinated plasma processes, the mechanisms that fundamentally limit the etching of silicon are poorly understood. In an effort to improve our understanding of limits to the performance of such systems, the etching of silicon wafers in an inductive coupled plasma reactor, using SF6, has been studied. A systematic empirical investigation has allowed us to define many of the experimental parameters that control the etching rate.
There is little temperature dependence of etching which suggests a diffusion limited process. Systematic variation of parameters controlling the rate of etching: total pressure in the reactor, flow rate, partial pressure of reactive species and the rf power supplied to the discharge enable us to accurately define the performance of the system. Experiments, which segregate the physical and chemical components of the etching process, support the conclusion that etching is dominated by electrically neutral species. These various results are interpreted in terms of accepted models for the reactive chemistry in plasmas containing SF6.
The MEMS industry is placing ever greater demands on etching processes, and there is a need to achieve the high degrees of anisotropy, and critical dimension control, at high etch-rates. The approach outlined allows us to develop effective strategies for evolving improved systems for the high rate plasma etching of silicon.
In the ongoing enhancement of MEMS applications, the STS Advanced Silicon Etch, (ASETM). process satisfies the demanding requirements of the industry. Typically, highly anisotropic. high aspect ratios profiles with fine CD (critical dimension) control are required. Selectivities to photoresist of 150:1 with Si etch rates of up to 10μm/min are demonstrated. Applications range from shallow etched optical devices to through wafer membrane etches. This paper details some of the fundamental trends of the ASETM process and goes on to discuss how the process has been enhanced to meet product specifications. Parameter ramping is a powerful technique used to achieve the often-conflicting requirements of high etch rate with good profile/CD control. The results are presented in this paper.
Disease ecology refers to the intricate human and environmental relationships that form the context of one or a group of diseases. Diseases are not simply biomedical entities; rather, they have their physical, environmental, sociocultural, psychological, and even political parameters. Distinctive human and biophysical environmental webs form the context of distinctive groups of human diseases. Major changes in this web, whether brought about by human intervention, environmental catastrophes, or a combination thereof, can result in a new context and possibly a new group of diseases. In developing countries, human control of the environment is limited, basic needs of a healthful life are not met, and, therefore, infectious and communicable diseases are the major cause of death. Improvements in health conditions will no doubt reduce the incidence of mortality resulting from infectious diseases and, in turn, bring about the prominence of chronic diseases more closely related to life-styles and life stages than to environmental parameters. South Asia as a geographic region still remains a region of poverty within which there is a marked contrast between the rural and urban genre de vie. Morbidity and mortality patterns in the rural and urban areas are, therefore, likely to be somewhat different, although paucity and quality of data make generalizations hazardous.
Ecologically, South Asia is one of the most distinctive regions of the world. Physiographically well demarcated, and climatically distinguished by the monsoonal rainfall regime, South Asian life has a rhythm marked by seasonality. Although agriculture is still the dominant occupation, rapidly swelling cities create air pollution, overcrowding, social stress, and the immense problem of waste disposal.