Weekly variability of clupeoid eggs and larvae in the Benguela jet current: implications for recruitment

Weekly sampling of ichthyoplankton, current vectors and surface temperature along a 34-mile transect crossing the jet current off the Cape Peninsula was conducted from August 1995 to July 1996 as part of thethird phase of the South African Sardine and Anchovy Recruitment Programme, designed to investigate within-season variability in factors affecting sardine Sardinops sagax and anchovy Engraulis capensisrecruitment. Anchovy eggs and larvae were found from October 1995 to February 1996, with most intense spawning from mid-October to early December. Peak abundances of anchovy eggs (717.m–2) and larvae(342.m–2) were encountered during mid-November. Sardine eggs and larvae were found throughout the year, but were most abundant from August 1995 to February 1996. Numbers  ere greatest during late September, reaching 630 eggs.m–2 and 142 larvae.m–2, with secondary peaks of >200 eggs.m–2 during August, October and January. Spawning products were low from March onwards, but increased slightly during July 1996. Current vectors indicated that spawning prior to December was most favourable for transport of eggs and larvae to the West Coast nursery area. January and February were characterized by increasingly complexflow patterns, while the frontal jet current was positioned offshore of the transect for most of March and April as a result of prolonged periods of upwelling. Monthly length-frequency distributions of larvae indicatedspawning by both species farther east on the western Agulhas Bank later in the season, or more complex transport from that region to the sampling area. Mean monthly (August–March) anchovy and sardine (September – February) egg abundances were significantly correlated (p < 0.05) with the estimated birthdate distribution of recruits, suggesting that frequent monitoring of egg abundance along the transect may be usefulfor forecasting recruitment strength

Privacy Preserving Multi-Server k-means Computation over Horizontally Partitioned Data

The k-means clustering is one of the most popular clustering algorithms in data mining. Recently a lot of research has been concentrated on the algorithm when the dataset is divided into multiple parties or when the dataset is too large to be handled by the data owner. In the latter case, usually some servers are hired to perform the task of clustering. The dataset is divided by the data owner among the servers who together perform the k-means and return the cluster labels to the owner. The major challenge in this method is to prevent the servers from gaining substantial information about the actual data of the owner. Several algorithms have been designed in the past that provide cryptographic solutions to perform privacy preserving k-means. We provide a new method to perform k-means over a large set using multiple servers. Our technique avoids heavy cryptographic computations and instead we use a simple randomization technique to preserve the privacy of the data. The k-means computed has exactly the same efficiency and accuracy as the k-means computed over the original dataset without any randomization. We argue that our algorithm is secure against honest but curious and passive adversary.Comment: 19 pages, 4 tables. International Conference on Information Systems Security. Springer, Cham, 201

Risk of post-pregnancy hypertension in women with a history of hypertensive disorders of pregnancy: nationwide cohort study.

Objectives To determine how soon after delivery the risk of post-pregnancy hypertension increases in women with hypertensive disorders of pregnancy and how the risk evolves over time.Design Nationwide register based cohort study.Setting Denmark.Populations 482 972 primiparous women with a first live birth or stillbirth between 1995 and 2012 (cumulative incidence analyses), and 1 025 118 women with at least one live birth or stillbirth between 1978 and 2012 (Cox regression analyses).Main outcome measures 10 year cumulative incidences of post-pregnancy hypertension requiring treatment with prescription drugs, and hazard ratios estimated using Cox regression.Results Of women with a hypertensive disorder of pregnancy in a first pregnancy in their 20s, 14% developed hypertension in the first decade post partum, compared with 4% of women with normotensive first pregnancies in their 20s. The corresponding percentages for women with a first pregnancy in their 40s were 32% and 11%, respectively. In the year after delivery, women with a hypertensive disorder of pregnancy had 12-fold to 25-fold higher rates of hypertension than did women with a normotensive pregnancy. Rates in women with a hypertensive disorder of pregnancy were threefold to 10-fold higher 1-10 years post partum and remained twice as high even 20 or more years later.Conclusions The risk of hypertension associated with hypertensive disorders of pregnancy is high immediately after an affected pregnancy and persists for more than 20 years. Up to one third of women with a hypertensive disorder of pregnancy may develop hypertension within a decade of an affected pregnancy, indicating that cardiovascular disease prevention in these women should include blood pressure monitoring initiated soon after pregnancy

Beyond wasted and stunted—a major shift to fight child undernutrition

Child undernutrition refers broadly to the condition in which food intake is inadequate to meet a child's needs for physiological function, growth, and the capacity to respond to illness. Since the 1970s, nutritionists have categorised undernutrition in two major ways, either as wasted (ie, low weight for height, or small mid-upper arm circumference) or stunted (ie, low height for age). This approach, although useful for identifying populations at risk of undernutrition, creates several problems: the focus is on children who have already become undernourished, and this approach draws an artificial distinction between two idealised types of undernourished children that are widely interpreted as indicative of either acute or chronic undernutrition. This distinction in turn has led to the separation of programmatic approaches to prevent and treat child undernutrition. In the past 3 years, research has shown that individual children are at risk of both conditions, might be born with both, pass from one state to the other over time, and accumulate risks to their health and life through their combined effects. The current emphasis on identifying children who are already wasted or stunted detracts attention from the larger number of children undergoing the process of becoming undernourished. We call for a major shift in thinking regarding how we assess child undernutrition, and how prevention and treatment programmes can best address the diverse causes and dynamic biological processes that underlie undernutrition

Installing the "magic methyl" - C-H methylation in synthesis

The selective and efficient C-H methylation of sp2 and sp3 carbon centres has become a powerful transformation in the synthetic toolbox. Due to the potential for profound changes to physicochemical properties attributed to the installation of a "Magic Methyl" group at a strategic site in a lead compound, such techniques have become highly desirable in modern drug discovery and synthesis programmes. This review will cover the diverse techniques that have been employed to enable the selective installation of the C-Me bond in a wide range of chemical structures, from simple building blocks to complex drug-like architectures

Bone versus breast density

The common link with oestrogen levels suggests that bone mineral density and mammographic density might also be linked. One study found weak support for this, but another study failed to provide confirmation. Overall, the relationship is very weak, if it exists at all. Other factors such as weight-bearing exercise, which have opposing impacts on these variables, may have a more dominant effect

Migration of Apicomplexa Across Biological Barriers: The Toxoplasma and Plasmodium Rides

The invasive stages of Apicomplexa parasites, called zoites, have been largely studied in in vitro systems, with a special emphasis on their unique gliding and host cell invasive capacities. In contrast, the means by which these parasites reach their destination in their hosts are still poorly understood. We summarize here our current understanding of the cellular basis of in vivo parasitism by two well-studied Apicomplexa zoites, the Toxoplasma tachyzoite and the Plasmodium sporozoite. Despite being close relatives, these two zoites use different strategies to reach their goal and establish infection

Quantifying short-term dynamics of Parkinson's disease using self-reported symptom data from an internet social network

Background: Parkinson’s disease (PD) is an incurable neurological disease with approximately 0.3% prevalence. The hallmark symptom is gradual movement deterioration. Current scientific consensus about disease progression holds that symptoms will worsen smoothly over time unless treated. Accurate information about symptom dynamics is of critical importance to patients, caregivers, and the scientific community for the design of new treatments, clinical decision making, and individual disease management. Long-term studies characterize the typical time course of the disease as an early linear progression gradually reaching a plateau in later stages. However, symptom dynamics over durations of days to weeks remains unquantified. Currently, there is a scarcity of objective clinical information about symptom dynamics at intervals shorter than 3 months stretching over several years, but Internet-based patient self-report platforms may change this. Objective: To assess the clinical value of online self-reported PD symptom data recorded by users of the health-focused Internet social research platform PatientsLikeMe (PLM), in which patients quantify their symptoms on a regular basis on a subset of the Unified Parkinson’s Disease Ratings Scale (UPDRS). By analyzing this data, we aim for a scientific window on the nature of symptom dynamics for assessment intervals shorter than 3 months over durations of several years. Methods: Online self-reported data was validated against the gold standard Parkinson’s Disease Data and Organizing Center (PD-DOC) database, containing clinical symptom data at intervals greater than 3 months. The data were compared visually using quantile-quantile plots, and numerically using the Kolmogorov-Smirnov test. By using a simple piecewise linear trend estimation algorithm, the PLM data was smoothed to separate random fluctuations from continuous symptom dynamics. Subtracting the trends from the original data revealed random fluctuations in symptom severity. The average magnitude of fluctuations versus time since diagnosis was modeled by using a gamma generalized linear model. Results: Distributions of ages at diagnosis and UPDRS in the PLM and PD-DOC databases were broadly consistent. The PLM patients were systematically younger than the PD-DOC patients and showed increased symptom severity in the PD off state. The average fluctuation in symptoms (UPDRS Parts I and II) was 2.6 points at the time of diagnosis, rising to 5.9 points 16 years after diagnosis. This fluctuation exceeds the estimated minimal and moderate clinically important differences, respectively. Not all patients conformed to the current clinical picture of gradual, smooth changes: many patients had regimes where symptom severity varied in an unpredictable manner, or underwent large rapid changes in an otherwise more stable progression. Conclusions: This information about short-term PD symptom dynamics contributes new scientific understanding about the disease progression, currently very costly to obtain without self-administered Internet-based reporting. This understanding should have implications for the optimization of clinical trials into new treatments and for the choice of treatment decision timescales

A Laser/EMAT Concurrent Weld Inspection System

A noncontacting ultrasonic sensor system is being developed for online inspection of thick section welds made by a robotic gas metal arc welding (GMAW) system. The sensor system consists of a pulsed laser for generating the ultrasound and an electromagnetic-acoustic transducer (EMAT) for receiving it. The sensor will follow closely behind the weld head and inspect the solidified weld bead for flaws. The main advantage of this technique is that flaws can be found and repaired before they are covered by subsequent welding passes. This is expected to be much simpler and less likely to induce further flaws than current practice since a large amount of otherwise good weld metal need not be removed to reach and repair a flaw. The system also monitors the welding process, i.e., detection of a large number of flaws indicates that the process is no longer operating as planned. In this paper, the technique for detecting incomplete sidewall penetration is demonstrated and methods for improving the system are discussed.</p