1,706 research outputs found
Distance from a fishing community explains fish abundance in a no-take zone with weak compliance
There are numerous examples of no-take marine reserves effectively conserving fish stocks within their boundaries. However, no-take reserves can be rendered ineffective and turned into ‘paper parks’ through poor compliance and weak enforcement of reserve regulations. Long-term monitoring is thus essential to assess the effectiveness of marine reserves in meeting conservation and management objectives. This study documents the present state of the 15-year old no-take zone (NTZ) of South El Ghargana within the Nabq Managed Resource Protected Area, South Sinai, Egyptian Red Sea. Previous studies credited willing compliance by the local fishing community for the increased abundances of targeted fish within the designated NTZ boundaries compared to adjacent fished or take-zones. We compared benthic habitat and fish abundance within the NTZ and the adjacent take sites open to fishing, but found no significant effect of the reserve. Instead, the strongest evidence was for a simple negative relationship between fishing pressure and distance from the closest fishing village. The abundance of targeted piscivorous fish increased significantly with increasing distance from the village, while herbivorous fish showed the opposite trend. This gradient was supported by a corresponding negative correlation between the amount of discarded fishing gear observed on the reef and increasing distance from the village. Discarded fishing gear within the NTZ suggested decreased compliance with the no-take regulations. Our findings indicate that due to non-compliance the no-take reserve is no longer functioning effectively, despite its apparent initial successes and instead a gradient of fishing pressure exists with distance from the nearest fishing community
Altered Ca(2+ )homeostasis in polymorphonuclear leukocytes from chronic myeloid leukaemia patients
BACKGROUND: In polymorphonuclear leukocytes (PMNL), mobilization of calcium ions is one of the early events triggered by binding of chemoattractant to its receptors. Besides chemotaxis, a variety of other functional responses are dependent on calcium ion mobilization. PMNL from chronic myeloid leukaemia (CML) patients that were morphologically indistinguishable from normal PMNL were found to be defective in various functions stimulated by a chemoattractant – fMLP. To study the mechanism underlying defective functions in CML PMNL, we studied calcium mobilization in CML PMNL in response to two different classical chemoattractants, fMLP and C5a. RESULTS: Release of calcium estimated by flow cytometry and spectrofluorimetry using fluo-3 as an indicator showed that the [Ca(2+)](i )levels were lower in CML PMNL as compared to those in normal PMNL. But, both normal and CML PMNL showed maximum [Ca(2+)](i )in response to fMLP and C5a at 10 sec and 30 sec, respectively. Spectrofluorimetric analysis of the total calcium release in chemoattractant treated PMNL indicated more and faster efflux of [Ca(2+)](i )in CML PMNL as compared to normal PMNL. CONCLUSION: Fine-tuning of Ca(2+ )homeostasis was altered in CML PMNL. The altered Ca(2+ )homeostasis may contribute to the defective functions of CML PMNL
Minnorm training: an algorithm for training over-parameterized deep neural networks
In this work, we propose a new training method for finding minimum weight
norm solutions in over-parameterized neural networks (NNs). This method seeks
to improve training speed and generalization performance by framing NN training
as a constrained optimization problem wherein the sum of the norm of the
weights in each layer of the network is minimized, under the constraint of
exactly fitting training data. It draws inspiration from support vector
machines (SVMs), which are able to generalize well, despite often having an
infinite number of free parameters in their primal form, and from recent
theoretical generalization bounds on NNs which suggest that lower norm
solutions generalize better. To solve this constrained optimization problem,
our method employs Lagrange multipliers that act as integrators of error over
training and identify `support vector'-like examples. The method can be
implemented as a wrapper around gradient based methods and uses standard
back-propagation of gradients from the NN for both regression and
classification versions of the algorithm. We provide theoretical justifications
for the effectiveness of this algorithm in comparison to early stopping and
-regularization using simple, analytically tractable settings. In
particular, we show faster convergence to the max-margin hyperplane in a
shallow network (compared to vanilla gradient descent); faster convergence to
the minimum-norm solution in a linear chain (compared to -regularization);
and initialization-independent generalization performance in a deep linear
network. Finally, using the MNIST dataset, we demonstrate that this algorithm
can boost test accuracy and identify difficult examples in real-world datasets
An Overview of Research, Research Paper and Thesis: Evidence From Literature Review
In this study an attempt has been made to answer the questions “What are Research and its types?” What is difference between research paper and article? What is difference between project report, thesis and dissertation? A systematic literature review is undertaken giving an overview of its processes and principles. Research’ is a particular type of investigation. It is impossible to do research without having a problem, which is required to be resolved, or a question, which needs to be answered but it is difficult for scholars to select and write topic, statement of purpose and thesis, so the solutions of these are given in this article. The definition and evolution of the approach are described, including the various kinds of research being used today. The research procedure and its nature have been discussed from different scholars’ point of view. This article also seeks to organize the scattered knowledge at one point to get research scholars equipped with the latest knowledge. Finally, this study has revealed that research is purposeful and solution-oriented investigation which needs every step properly written. Guidelines given in this study are very clear to help the student to complete their article thesis and dissertation so researchers are advised to follow the guidelines to write quality thesis
Evaluation of preferences of women and healthcare professionals in Singapore for implementation of noninvasive prenatal testing for Down syndrome
INTRODUCTION: Invasive prenatal diagnosis (IPD) has long been used to prenatally diagnose Down syndrome (DS), but is associated with a small risk of miscarriage. Meanwhile, noninvasive prenatal testing (NIPT) is a highly sensitive screening test using cell-free DNA in maternal blood for detection of DS that removes the risk of miscarriage, but confers a small risk of false-positive and false-negative results. Their implementations into clinical practice require an understanding of stakeholder preferences. METHODS: A total of 69 health professionals (HPs) and 301 women took part in a discrete choice experiment (DCE) in which preferences for four prenatal test attributes (accuracy, time of results, risk of miscarriage and amount of information provided) were assessed, and conditional logit regression was used to analyse data. Data on demographics and ranked preferences for test attributes were collected, and a direct choice between NIPT, IPD or neither test was given. RESULTS: Women showed a preference for test safety, whereas HPs prioritised test accuracy above all other attributes. When offered a direct choice between NIPT, IPD or neither test, women aged over 35 years, those with previous miscarriage or who knew a child with DS were more likely to choose NIPT than IPD. Chinese women preferred NIPT whereas Indian women preferred IPD. CONCLUSION: Our data highlight the need for patient-specific counselling, taking into account previous experiences and cultural factors. Since women and HPs prioritise different test attributes, it is essential that HPs recognise these differences in order to provide non-biased counselling
Hyperglycemia and Renal Mass Ablation Synergistically Augment Albuminuria in the Diabetic Subtotally Nephrectomized Rat: Implications for Modeling Diabetic Nephropathy
Background/Aims: While experimental models that emulate diabetic nephropathy are valuable tools for elucidating pathogenetic mechanisms and developing novel therapies, existing models imperfectly recapitulate human disease. In diabetes, hyperglycemia and hemodynamic forces act in concert to induce renal injury. Accordingly, in the present study, we combined streptozotocin-induced diabetes with surgical ablation of 5/6 of the kidney mass with the aim of evaluating their additive effects on renal function and glomerular morphology. Methods: Female F344 rats were randomized to undergo subtotal nephrectomy (SNx) either at baseline or following 4 weeks of diabetes. Results: In comparison to sham rats, rats with diabetes or rats after SNx surgery, diabetic subtotally nephrectomized (DM-SNx) rats demonstrated an increase in systolic blood pressure, glomerular volume and mesangial matrix. Albuminuria was synergistically increased by hyperglycemia and renal mass ablation associated with decreased nephrin expression. In contrast, glomerular capillary rarefaction and glomerular filtration rate were similarly reduced in SNx and DM-SNx rats. Conclusion: The DM-SNx rat recapitulates some of the features of human disease, most notably augmented albuminuria. Since this model avoids the deletion or overexpression of gene(s) linked to the pathogenesis of nephropathy, the DM-SNx rat model represents a complementary tool for the trial of novel therapies
Anti-tubulin drugs conjugated to anti-ErbB antibodies selectively radiosensitize.
Tumour resistance to radiotherapy remains a barrier to improving cancer patient outcomes. To overcome radioresistance, certain drugs have been found to sensitize cells to ionizing radiation (IR). In theory, more potent radiosensitizing drugs should increase tumour kill and improve patient outcomes. In practice, clinical utility of potent radiosensitizing drugs is curtailed by off-target side effects. Here we report potent anti-tubulin drugs conjugated to anti-ErbB antibodies selectively radiosensitize to tumours based on surface receptor expression. While two classes of potent anti-tubulins, auristatins and maytansinoids, indiscriminately radiosensitize tumour cells, conjugating these potent anti-tubulins to anti-ErbB antibodies restrict their radiosensitizing capacity. Of translational significance, we report that a clinically used maytansinoid ADC, ado-trastuzumab emtansine (T-DM1), with IR prolongs tumour control in target expressing HER2+ tumours but not target negative tumours. In contrast to ErbB signal inhibition, our findings establish an alternative therapeutic paradigm for ErbB-based radiosensitization using antibodies to restrict radiosensitizer delivery
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