5,700 research outputs found

    Nanointerfacial strength between non-collagenous protein and collagen fibrils in antler bone

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    This research was supported by the Engineering and Physical Science Research Council, UK (grant award EP/E039928/1)

    The Methods to Improve Quality of Service by Accounting Secure Parameters

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    A solution to the problem of ensuring quality of service, providing a greater number of services with higher efficiency taking into account network security is proposed. In this paper, experiments were conducted to analyze the effect of self-similarity and attacks on the quality of service parameters. Method of buffering and control of channel capacity and calculating of routing cost method in the network, which take into account the parameters of traffic multifractality and the probability of detecting attacks in telecommunications networks were proposed. The both proposed methods accounting the given restrictions on the delay time and the number of lost packets for every type quality of service traffic. During simulation the parameters of transmitted traffic (self-similarity, intensity) and the parameters of network (current channel load, node buffer size) were changed and the maximum allowable load of network was determined. The results of analysis show that occurrence of overload when transmitting traffic over a switched channel associated with multifractal traffic characteristics and presence of attack. It was shown that proposed methods can reduce the lost data and improve the efficiency of network resources.Comment: 10 pages, 1 figure, 1 equation, 1 table. arXiv admin note: text overlap with arXiv:1904.0520

    Asymmetry to symmetry transition of Fano line-shape: Analytical derivation

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    An analytical derivation of Fano line-shape asymmetry ratio has been presented here for a general case. It is shown that Fano line-shape becomes less asymmetric as \q is increased and finally becomes completely symmetric in the limiting condition of q equal to infinity. Asymmetry ratios of Fano line-shapes have been calculated and are found to be in good consonance with the reported expressions for asymmetry ratio as a function of Fano parameter. Application of this derivation is also mentioned for explanation of asymmetry to symmetry transition of Fano line-shape in quantum confined silicon nanostructures.Comment: 3 figures, Latex files, Theoretica

    Clinicopathological Profile and Surgical Treatment of Abdominal Tuberculosis: A Single Centre Experience in Northwestern Tanzania.

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    Abdominal tuberculosis continues to be a major public health problem worldwide and poses diagnostic and therapeutic challenges to general surgeons practicing in resource-limited countries. This study was conducted to describe the clinicopathological profile and outcome of surgical treatment of abdominal tuberculosis in our setting and compare with what is described in literature. A prospective descriptive study of patients who presented with abdominal tuberculosis was conducted at Bugando Medical Centre (BMC) in northwestern Tanzania from January 2006 to February 2012. Ethical approval to conduct the study was obtained from relevant authorities. Statistical data analysis was performed using SPSS version 17.0. Out of 256 patients enrolled in the study, males outnumbered females. The median age was 28 years (range = 16-68 years). The majority of patients (77.3%) had primary abdominal tuberculosis. A total of 127 (49.6%) patients presented with intestinal obstruction, 106 (41.4%) with peritonitis, 17 (6.6%) with abdominal masses and 6 (2.3%) patients with multiple fistulae in ano. Forty-eight (18.8%) patients were HIV positive. A total of 212 (82.8%) patients underwent surgical treatment for abdominal tuberculosis. Bands /adhesions (58.5%) were the most common operative findings. Ileo-caecal region was the most common bowel involved in 122 (57.5%) patients. Release of adhesions and bands was the most frequent surgical procedure performed in 58.5% of cases. Complication and mortality rates were 29.7% and 18.8% respectively. The overall median length of hospital stay was 32 days and was significantly longer in patients with complications (p < 0.001). Advanced age (age ≥ 65 years), co-morbid illness, late presentation, HIV positivity and CD4+ count < 200 cells/μl were statistically significantly associated with mortality (p < 0.0001). The follow up of patients were generally poor as only 37.5% of patients were available for follow up at twelve months after discharge. Abdominal tuberculosis constitutes a major public health problem in our environment and presents a diagnostic challenge requiring a high index of clinical suspicion. Early diagnosis, early anti-tuberculous therapy and surgical treatment of the associated complications are essential for survival

    Justice at Sea: Fishers’ politics and marine conservation in coastal Odisha, India

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    This is a paper about the politics of fishing rights in and around the Gahirmatha marine sanctuary in coastal Odisha, in eastern India. Claims to the resources of this sanctuary are politicised through the creation of a particularly damaging narrative by influential Odiya environmental actors about Bengalis, as illegal immigrants who have hurt the ecosystem through their fishing practices. Anchored within a theoretical framework of justice as recognition, the paper considers the making of a regional Odiya environmentalism that is, potentially, deeply exclusionary. It details how an argument about ‘illegal Bengalis’ depriving ‘indigenous Odiyas’ of their legitimate ‘traditional fishing rights’ derives from particular notions of indigeneity and territory. But the paper also shows that such environmentalism is tenuous, and fits uneasily with the everyday social landscape of fishing in coastal Odisha. It concludes that a wider class conflict between small fishers and the state over a sanctuary sets the context in which questions about legitimate resource rights are raised, sometimes with important effects, like when out at sea

    In vitro plant regeneration in rough lemon (Citrus jambhiri Lush) by direct organogenesis

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    This study was aimed to optimize the organogenesis in rough lemon (Citrus jambhiri Lush), an important citrus rootstock of India. Organogenesis was induced in epicotyl segments of rough lemon seedlings. Three important factors influencing organogenesis in vitro viz. hormone combination, cut modes and photoperiod were evaluated. Etiolation of seedlings had a positive effect on bud formation and higher number of buds per explant was obtained from etiolated seedlings. Among the cut modes, transverse cut performed better for its effect on the number of regenerated buds and shoots per explant. The best response regarding the number of adventitious buds formed per explant was observed with BAP at the concentration of 2.0 mg/l along with malt extract (500 ppm) and additional dose of 25 g/l sucrose.Key words: Citrus, epicotyl, hypocotyl, etiolation, transverse cut, longitudinal cut, photoperiod

    Urgent carotid endarterectomy for acute cerebral ischemia

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    Background-Carotid endarterectomy (CEA) is well established as the elective treatment for severe symptomatic carotid stenosis . In contrast, the merits of CEA performed as an emergency procedure in patients with acute stroke or fluctuating neurological deficit remain controversial.Material Methods-CEA was performed as an emergency procedure on 16 patients within 4 to 48 hours after the onset of symptoms. Patients selected for urgent surgery fulfilled the following criteria: acute onset of fluctuating hemispheric neurological symptoms, significant carotid pathology, absence of cerebral hemorrhage, absence of massive cerebral damage and stable cardiopulmonary conditions. The patients presented with a crescendo-TIA in 7, evolving (stuttering) stroke in 3 and fluctuating neurological deficits in 6 - corresponding to a contralateral carotid stenosis.Results-Following CEA, the neurological deficits improved instantaneously to complete recovery in 10 patients. The symptoms of 4 patients improved to non-disabling deficits, and remained unchanged in two patients. 14/16 patients were discharged within 8 days after admission. The neurologic status after discharge did not deteriorate in any of the patients during follow up - in fact it further improved in 4 of the patients (2 in whom there had been no change and 2 in whom there had been a partial improvement).Conclusion-Emergency CEA may be beneficial for selected patients with stroke in evolution and fluctuating neurological deficits. Careful adherence to selection criteria, judicious intraoperative shunting, intensive unit care post surgery and an experienced team are recommended

    Prime movers : mechanochemistry of mitotic kinesins

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    Mitotic spindles are self-organizing protein machines that harness teams of multiple force generators to drive chromosome segregation. Kinesins are key members of these force-generating teams. Different kinesins walk directionally along dynamic microtubules, anchor, crosslink, align and sort microtubules into polarized bundles, and influence microtubule dynamics by interacting with microtubule tips. The mechanochemical mechanisms of these kinesins are specialized to enable each type to make a specific contribution to spindle self-organization and chromosome segregation

    Unlocking the secrets of mutable collagenous tissue

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    © Biochemical Society. The mutable collagenous tissue (MCT) of echinoderms (e.g. sea cucumbers, starfish and sea urchins) is unique because of its ability to 'switch' mechanical states rapidly and reversibly - from stiff to soft and vice versa. This kind of tissue in humans, for example, in skin, tendons and ligaments, does not have this property. So what are the molecular-level secrets by which MCT achieves this transformative ability? New real-time ultrastructural investigations are beginning to shed light on this question. Synchrotron X-ray measurements of dynamic molecular conformational changes point to the key factor being the gel-like matrix between the collagen fibrils. These findings could have applications for developing treatments for collagen-based disorders
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