Indian marine fishery resources: optimistic present, challenging future

Marine fish production from capture fisheries in India has increased by about six fold during the past six decades. Export earnings from the marine sector crossed 12,000 crores in 2010-11 and gross revenue through marine fish landings at the point of first sales was about 20,000 crores. Marine products are now exported from India to nearly 100 countries. Monitoring the harvest of different marine fishery resources is very much essential for planning and implementing policies for sustained production from the sea. The dynamic changes in the landings of marine fishery resources over the last six decades were examined after classifying them into 26 different resource groups. Decadal averages of landings of different resource groups were compared using Student’s t test and coefficient of variation was worked out for each decade. Present status of each resource group was examined separately based on a simple criterion. Out of the 26 groups examined, 18 were found to be under the ‘abundant class, 5 under ‘less abundant’ class and one each under ‘declining’, ‘depleted’ and ‘collapsed’ classes. Elasmobranchs, threadfins, ribbonfishes, mullets and flatfishes are the five resource groups falling under ‘less abundant’ class. White fish falls under ‘declining’ class, flying fishes under ‘depleted’ class and unicorn cod under ‘collapsed’ class. All the other groups fall under the ‘abundant’ class indicating that most of the resources (73%) are in healthy condition. The ‘depleted’ and ‘collapsed’ classes require management interventions for the recovery of the resources and the group falling under ‘declining’ class needs caution and care to prevent further reduction in the stock

Hypertrophic cardiomyopathy and ultra-endurance running - two incompatible entities?

Regular and prolonged exercise is associated with increased left ventricular wall thickness that can overlap with hypertrophic cardiomyopathy (HCM). Differentiating physiological from pathological hypertrophy has important implications, since HCM is the commonest cause of exercise-related sudden cardiac death in young individuals. Most deaths have been reported in intermittent 'start-stop' sports such as football (soccer) and basketball. The theory is that individuals with HCM are unable to augment stroke volume sufficiently to meet the demands of endurance sports and are accordingly 'selected-out' of participation in such events. We report the case of an ultra-endurance athlete with 25 years of > 50 km competitive running experience, with genetically confirmed HCM; thereby demonstrating that these can be two compatible entities

Debate:Challenges in sports cardiology; US versus European approaches

For practitioners working with elite athletes, the field of sports cardiology provides clinical, academic, administrative and fiscal challenges. These challenges are exemplified and reinforced by the lack of consistency and consensus both in the literature and academic presentations. Through thepresentation of a series of clinical questions, this debate attempts to ‘cut to the chase’ on cardiovascular issues relevant to the clinician dealing with elite athletes. In so doing, we hope to crystallize some of the most important elements of the complex cardiological management of elite athletes, in a concise, readable format. Frequently over the last 10 years, many of the controversies in this field have been (rightly or wrongly) presented in aEurope versus USA paradigm. We have chosen to test whether there really are polarised views across the Atlantic, by deliberately pitting specialists from the USA against those from the UK. Professors Levine and Thompson are both internationally recognised sports cardiologists, with immense academic and clinical credibility, and who will represent the ‘US approach’. Professor Whyte and Doctor Wilson are cardiac physiologists with a wealth of experience in the testing, evaluation and screening of elite athletes, and who have equally impressive academic credibility and for the purposes of this debate, they will be representing the ‘European approach’. To initiate this process, each team was required to provide a concise answer (circa 200–300 words) to a series of fiveclinical conundrums. Subsequently, each team had the opportunity to provide a rebuttal to the opposing team’s answers, and the following reflects the consolidation of those answers

Vapour polishing of fused deposition modelling (FDM) parts: a critical review of different techniques, and subsequent surface finish and mechanical properties of the post-processed 3D-printed parts

Fused deposition modelling (FDM), one of the most commonly used additive manufacturing techniques in the industry, involves layer-by-layer deposition of melted material to create a 3D structure. The staircase and beading effect caused by the printing process and temperature variation cause delamination and poor surface finish in FDM-printed parts. This hinders the use of these specimens in various applications, which are then usually resolved using pre-processing and post-processing techniques. Higher surface finish in pre-processing is achieved by increasing the resolution, changing layer thickness and optimizing build orientation. However, this increases the processing time considerably. On the other hand, post-processing techniques involve different processes such as mechanical, chemical, thermal and hybrid methods but can affect the mechanical and structural properties of the printed components. This review paper analyses three different aspects in the area of improving the surface finish of FDM-printed parts. First, this article reviews the state-of-the-art attempts made to improve the surface finish of FDM-printed parts concentrated mainly on different vapour polishing techniques and their respective merits and demerits. Second, it focuses on the changes in mechanical properties before and after polishing. Finally, the paper explores the development in the 3D printing of thermosets and composite materials and their post-processing processes and process parameters

Oak forest carbon and water simulations:Model intercomparisons and evaluations against independent data

Models represent our primary method for integration of small-scale, process-level phenomena into a comprehensive description of forest-stand or ecosystem function. They also represent a key method for testing hypotheses about the response of forest ecosystems to multiple changing environmental conditions. This paper describes the evaluation of 13 stand-level models varying in their spatial, mechanistic, and temporal complexity for their ability to capture intra- and interannual components of the water and carbon cycle for an upland, oak-dominated forest of eastern Tennessee. Comparisons between model simulations and observations were conducted for hourly, daily, and annual time steps. Data for the comparisons were obtained from a wide range of methods including: eddy covariance, sapflow, chamber-based soil respiration, biometric estimates of stand-level net primary production and growth, and soil water content by time or frequency domain reflectometry. Response surfaces of carbon and water flux as a function of environmental drivers, and a variety of goodness-of-fit statistics (bias, absolute bias, and model efficiency) were used to judge model performance. A single model did not consistently perform the best at all time steps or for all variables considered. Intermodel comparisons showed good agreement for water cycle fluxes, but considerable disagreement among models for predicted carbon fluxes. The mean of all model outputs, however, was nearly always the best fit to the observations. Not surprisingly, models missing key forest components or processes, such as roots or modeled soil water content, were unable to provide accurate predictions of ecosystem responses to short-term drought phenomenon. Nevertheless, an inability to correctly capture short-term physiological processes under drought was not necessarily an indicator of poor annual water and carbon budget simulations. This is possible because droughts in the subject ecosystem were of short duration and therefore had a small cumulative impact. Models using hourly time steps and detailed mechanistic processes, and having a realistic spatial representation of the forest ecosystem provided the best predictions of observed data. Predictive ability of all models deteriorated under drought conditions, suggesting that further work is needed to evaluate and improve ecosystem model performance under unusual conditions, such as drought, that are a common focus of environmental change discussions

Global and regional cardiac function in lifelong endurance athletes with and without myocardial fibrosis

The aim of the present study was to compare cardiac structure as well as global and regional cardiac function in athletes with and without myocardial fibrosis (MF). Cardiac magnetic resonance imaging with late gadolinium enhancement was used to detect MF and global cardiac structure in nine lifelong veteran endurance athletes (58 ± 5 years, 43 ± 5 years of training). Transthoracic echocardiography using tissue-Doppler and myocardial strain imaging assessed global and regional (18 segments) longitudinal left ventricular function. MF was present in four athletes (range 1–8 g) and not present in five athletes. MF was located near the insertion points of the right ventricular free wall on the left ventricle in three athletes and in the epicardial lateral wall in one athlete. Athletes with MF demonstrated a larger end diastolic volume (205 ± 24 vs 173 ± 18 ml) and posterior wall thickness (11 ± 1 vs 9 ± 1 mm) compared to those without MF. The presence of MF did not mediate global tissue velocities or global longitudinal strain and strain rate; however, regional analysis of longitudinal strain demonstrated reduced function in some fibrotic regions. Furthermore, base to apex gradient was affected in three out of four athletes with MF. Lifelong veteran endurance athletes with MF demonstrate larger cardiac dimensions and normal global cardiac function. Fibrotic areas may demonstrate some co-localised regional cardiac dysfunction, evidenced by an affected cardiac strain and base to apex gradient. These data emphasize the heterogeneous phenotype of MF in athletes

Multi-lepton signals from the top-prime quark at the LHC

We analyze the collider signatures of models with a vector-like top-prime quark and a massive color-octet boson. The top-prime quark mixes with the top quark in the Standard Model, leading to richer final states than ones that are investigated by experimental collaborations. We discuss the multi-lepton final states, and show that they can provide increased sensitivity to models with a top-prime quark and gluon-prime. Searches for new physics in high multiplicity events are an important component of the LHC program and complementary to analyses that have been performed.Comment: 7 pages, 4 figures, 2 table

Demographic and socio-economic changes in the coastal fishing community of India

The spatial and temporal changes in the demographic and socio-economic indicators of coastal fishing community of India were studied using data collected during the national level census on marine fishermen population in 2005 and 2010, covering 11 maritime states and union territories of the country. Information on population growth, sex ratio, literacy level and educational status, poverty level, sectoral dependency and occupational categories of the coastal fisherfolk were analysed and compared with analogous figures of national averages on these socio-economic indicators. The marine fishermen of India, who depend on fisheries for their subsistence, were significantly below the national averages in many of key demographic indicators. The results of correspondence analysis carried out for visual description of the association of economic status with the key indicators showed that, the below poverty class among fishermen were more associated with low family size compared to large sized families, which implicates to labour supply in a labour demanding socio-economy of marine fisheries. Different dependency ratios were computed as a simple summary measure for comparison of age structure of fisherfolks