701 research outputs found
Current noise in high Tc granular superconductors under non-stationary conditions of current and magnetic field
We present a set of experimental results concerning the power spectrum of
current noise, detected on a granular high Tc superconductor submitted either
to a slowly varying magnetic field or to a varying current intensity.
Experiments were performed on a YBCO specimen suitably treated in order to
weaken the weak links without affecting the oxygen content of grains. The
weakening of the intergrain region allowed the use of very small magnetic
fields and currents to induce the resistive transition of the specimen and to
observe current noise. The induced noise is of the 1/f^2 type and will be
interpreted in terms of two different models. One of the model is based on the
enhancement of the noise due to the clustering of the resistive transition of
the weak links, produced by correlation effects related to the strong
nonlinearity of their Josephson type I-V characteristics. This model has been
the object of a computer simulation based on a 3D-network of Josephson-like
elements and seems suitable to explain the noise produced by current variation.
The second model explains the excess noise as produced by discontinuous
penetration of the magnetic flux inside the intergrain region. This
discontinuity is related to the field screening effect of rings made of several
superconducting weak links connecting different grains, which are alternatively
broken and restored by the current induced during flux variation, and seems
suitable to explain the larger noise produced by a varying magnetic field.Comment: 7 pages, 4 figures, conference contribution to "Fluctuations and
Noise", Santa Fe, New Mexico 1-4 June 200
Four-qubit entangled symmetric states with positive partial transpositions
We solve the open question of the existence of four-qubit entangled symmetric
states with positive partial transpositions (PPT states). We reach this goal
with two different approaches. First, we propose a
half-analytical-half-numerical method that allows to construct multipartite PPT
entangled symmetric states (PPTESS) from the qubit-qudit PPT entangled states.
Second, we adapt the algorithm allowing to search for extremal elements in the
convex set of bipartite PPT states [J. M. Leinaas, J. Myrheim, and E. Ovrum,
Phys. Rev. A 76, 034304 (2007)] to the multipartite scenario. With its aid we
search for extremal four-qubit PPTESS and show that generically they have ranks
(5,7,8). Finally, we provide an exhaustive characterization of these states
with respect to their separability properties.Comment: 5+4 pages, improved version, title slightly modifie
Review of Camel Calves Nutrition and Management in Kenya
Camels are important livestock species in the arid and semi-arid lands (ASALs) of Kenya. Camels provide milk, meat and serves as means of transport (drawing water, carry make shift houses, elderly people and children) for mobile pastoral communities. They supply milk and meat even during dry and drought periods when other livestock species struggle for their survival. Production systems for the camels are largely extensive with camel husbandry techniques mainly inherited from pastoral traditional knowledge passed down over generations. High calf mortality (about 63%) is a common phenomenon in the pastoral production systems of northern Kenya. A review was conducted to established causes of the high mortality and recommendations developed with a view to reduce mortality to manageable levels. This review showed that calf colostrum suckling restriction at birth, calf diarrhoea and other diseases, milk competition with calves for household consumption and income generation and limited forages during droughts were among the major causes of camel calf mortality. The review consolidated previous research on camel calves’ nutrition and management and has recommended nutrition and management tips to reduce mortality. Key words: calve mortality, milk competition, colostrum, supplementation, milk replacer. DOI: 10.7176/JNSR/10-8-04 Publication date: April 30th 202
Cultivating Connection
Student leadership is an increasingly utilized tool on college campuses for welcoming and supporting new students as they transition to college. In our various experiences as previous student leaders turned student affairs professionals, we found a common thread in our work which made a tremendous difference in the development of student leaders and the students they served—the ability to create and maintain meaningful empathic connections. This paper will provide structure for orientation, transition, and retention (OTR) professionals to cultivate empathy in student leaders who may use those skills to build stronger and more authentic connections as they welcome and help students successfully navigate their transition to college. The purpose of this paper is to fill a gap in empathic leadership development and its potential to positively impact the transition and retention of new students
Consensus conference on the management of tumor lysis syndrome.
Tumor lysis syndrome is a potentially life threatening complication of massive cellular lysis in cancers. Identification of high-risk patients and early recognition of the syndrome is crucial in the institution of appropriate treatments. Drugs that act on the metabolic pathway of uric acid to allantoin, like allopurinol or rasburicase, are effective for prophylaxis and treatment of tumor lysis syndrome. Sound recommendations should regulate diagnosis and drug application in the clinical setting. The current article reports the recommendations on the management of tumor lysis syndrome that were issued during a Consensus Conference project, and which were endorsed by the Italian Society of Hematology (SIE), the Italian Association of Pediatric Oncologists (AIEOP) and the Italian Society of Medical Oncology (AIOM). Current concepts on the pathophysiology, clinical features, and therapy of tumor lysis syndrome were evaluated by a Panel of 8 experts. A consensus was then developed for statements regarding key questions on tumor lysis syndrome management selected according to the criterion of relevance by group discussion. Hydration and rasburicase should be administered to adult cancer patients who are candidates for tumor-specific therapy and who carry a high risk of tumor lysis syndrome. Cancer patients with a low-risk of tumor lysis syndrome should instead receive hydration along with oral allopurinol. Hydration and rasburicase should also be administered to patients with clinical tumor lysis syndrome and to adults and high-risk children who develop laboratory tumor lysis syndrome. In conclusion, the Panel recommended rasburicase for tumor lysis syndrome prophylaxis in selected patients based on the drug efficacy profile. Methodologically rigorous studies are needed to clarify its cost-effectiveness profile
Determination of fatty acids ethyl esters in virgin olive oils: proposals to enhance the EU official method
Fatty acids ethyl esters (FAEEs) are markers for virgin olive oils obtained from olives of poor quality or not
adequately stored before being processed. FAEEs can also be considered as indirect markers in detecting the
illegal treatment of soft deodorization that can be applied to slightly defective olive oils, as they are difficult to be
removed from the oils at the conditions reached during this technological process. The official FAEEs determination
(EU Reg. 61/2011) suffers some drawbacks in terms of amount of solvents and long time of analysis, linked with the
preparative procedure to isolate these compounds.
The aim of this work is to study the application of an HPLC-UV as a rapid alternative approach to the traditional
liquid chromatography applied in the preparative phase. After the set up of the most appropriate working conditions
(eg. mobile phase, flow, injection volume), some validation parameters (eg. precision, accuracy, LOD and LOQ,
recovery) have been evaluated, in order to check the effectiveness of the proposed method. Moreover, considering
the GC-FID step, the use of a PTV (programmed temperature vaporizer) injector as an alternative of the on-column
one was evaluated.
This work is developed in the context of the project OLEUM \u201cAdvanced solutions for assuring authenticity and quality
of olive oil at global scale\u201c, funded by the European Commission within the Horizon 2020 Programme (2014\u20132020,
GA no. 635690). The information expressed in this abstract reflects the authors\u2019 views; the EC is not liable for the
information contained therein
Densidade de pragas e inimigos naturais em resposta ao tratamento de sementes de soja com inseticidas.
Objetivo: avaliar o efeito do tratamento de sementes de soja com inseticidas quĂmicos sobre a frequĂŞncia densidade populacional diária acumulada de insetos-praga e artrĂłpodes predadores da parte aĂ©rea da soja ao longo do desenvolvimento da cultura
Grape pomace polyphenols improve insulin response to a standard meal in healthy individuals: A pilot study
Dietary polyphenols have beneficial effects on glucose/lipid metabolism in subjects at high risk to develop type 2 diabetes; however, the underlying mechanisms are not clear. We aimed to evaluate: 1) the acute effects of the consumption of a drink rich in polyphenols from red grape pomace (RGPD) on glucose/insulin and triglyceride responses to a standard meal in healthy individuals, and, 2) the relationship between plasma levels of phenolic metabolites and metabolic parameters
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