273 research outputs found
Measurement of Exclusive B Decays to Final States Containing a Charmed Baryon
Using data collected by the CLEO detector in the Upsilon(4S) region, we
report new measurements of the exclusive decays of B mesons into final states
of the type Lambda_c^+ p-bar n(pi), where n=0,1,2,3. We find signals in modes
with one, two and three pions and an upper limit for the two body decay
Lambda_c^+ pbar. We also make the first measurements of exclusive decays of B
mesons to Sigma_c p-bar n(pi), where n=0,1,2. We find signals in modes with one
and two pions and an upper limit for the two body decay Sigma_c p-bar.
Measurements of these modes shed light on the mechanisms involved in B decays
to baryons.Comment: 11 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to PR
Observation of the Charmed Baryon at CLEO
The CLEO experiment at the CESR collider has used 13.7 fb of data to
search for the production of the (css-ground state) in
collisions at {\rm GeV}. The modes used to
study the are ,
, , , and
. We observe a signal of 40.49.0(stat) events
at a mass of 2694.62.6(stat)1.9(syst) {\rm MeV/}, for all modes
combined.Comment: 10 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
Measurements of B --> D_s^{(*)+} D^{*(*)} Branching Fractions
This article describes improved measurements by CLEO of the and branching fractions, and first evidence
for the decay , where
represents the sum of the , , and
L=1 charm meson states. Also reported is the first
measurement of the polarization in the decay . A partial reconstruction technique, employing only the fully
reconstructed and slow pion from the decay, enhances sensitivity. The observed branching fractions are
, , and , where the first error is statistical,
the second systematic, and the third is due to the uncertainty in the branching fraction. The measured longitudinal
polarization, , is consistent with
the factorization prediction of 54%.Comment: 26 pages (LaTeX), 15 figures. To be submitted to PR
Sustained Na<sup>+</sup>/H<sup>+</sup> exchanger activation promotes gliotransmitter release from reactive hippocampal astrocytes following oxygen-glucose deprivation
Hypoxia ischemia (HI)-related brain injury is the major cause of long-term morbidity in neonates. One characteristic hallmark of neonatal HI is the development of reactive astrogliosis in the hippocampus. However, the impact of reactive astrogliosis in hippocampal damage after neonatal HI is not fully understood. In the current study, we investigated the role of Na +/H+ exchanger isoform 1 (NHE1) protein in mouse reactive hippocampal astrocyte function in an in vitro ischemia model (oxygen/glucose deprivation and reoxygenation, OGD/REOX). 2 h OGD significantly increased NHE1 protein expression and NHE1-mediated H+ efflux in hippocampal astrocytes. NHE1 activity remained stimulated during 1-5 h REOX and returned to the basal level at 24 h REOX. NHE1 activation in hippocampal astrocytes resulted in intracellular Na+ and Ca2+ overload. The latter was mediated by reversal of Na+/Ca2+ exchange. Hippocampal astrocytes also exhibited a robust release of gliotransmitters (glutamate and pro-inflammatory cytokines IL-6 and TNFα) during 1-24 h REOX. Interestingly, inhibition of NHE1 activity with its potent inhibitor HOE 642 not only reduced Na+ overload but also gliotransmitter release from hippocampal astrocytes. The noncompetitive excitatory amino acid transporter inhibitor TBOA showed a similar effect on blocking the glutamate release. Taken together, we concluded that NHE1 plays an essential role in maintaining H + homeostasis in hippocampal astrocytes. Over-stimulation of NHE1 activity following in vitro ischemia disrupts Na+ and Ca2+ homeostasis, which reduces Na+-dependent glutamate uptake and promotes release of glutamate and cytokines from reactive astrocytes. Therefore, blocking sustained NHE1 activation in reactive astrocytes may provide neuroprotection following HI. © 2014 Cengiz et al
American Thyroid Association Guide to Investigating Thyroid Hormone Economy and Action in Rodent and Cell Models
Background: An in-depth understanding of the fundamental principles that regulate thyroid hormone homeostasis is critical for the development of new diagnostic and treatment ap-proaches for patients with thyroid disease. Summary: Important clinical practices in use today for the treatment of patients with hypothy-roidism, hyperthyroidism, or thyroid cancer, are the result of laboratory discoveries made by scientists investigating the most basic aspects of thyroid structure and molecular biology. In this document, a panel of experts commissioned by the American Thyroid Association makes a se-ries of recommendations related to the study of thyroid hormone economy and action. These recommendations are intended to promote standardization of study design, which should in turn increase the comparability and reproducibility of experimental findings. Conclusions: It is expected that adherence to these recommendations by investigators in the field will facilitate progress towards a better understanding of the thyroid gland and thyroid hormone dependent processes
Combined artificial bee colony algorithm and machine learning techniques for prediction of online consumer repurchase intention
A novel paradigm in the service sector i.e. services through the web is a progressive mechanism for rendering offerings over diverse environments. Internet provides huge opportunities for companies to provide personalized online services to their customers. But prompt novel web services introduction may unfavorably affect the quality and user gratification. Subsequently, prediction of the consumer intention is of supreme importance in selecting the web services for an application. The aim of study is to predict online consumer repurchase intention and to achieve this objective a hybrid approach which a combination of machine learning techniques and Artificial Bee Colony (ABC) algorithm has been used. The study is divided into three phases. Initially, shopping mall and consumer characteristic’s for repurchase intention has been identified through extensive literature review. Secondly, ABC has been used to determine the feature selection of consumers’ characteristics and shopping malls’ attributes (with > 0.1 threshold value) for the prediction model. Finally, validation using K-fold cross has been employed to measure the best classification model robustness. The classification models viz., Decision Trees (C5.0), AdaBoost, Random Forest (RF), Support Vector Machine (SVM) and Neural Network (NN), are utilized for prediction of consumer purchase intention. Performance evaluation of identified models on training-testing partitions (70-30%) of the data set, shows that AdaBoost method outperforms other classification models with sensitivity and accuracy of 0.95 and 97.58% respectively, on testing data set. This study is a revolutionary attempt that considers both, shopping mall and consumer characteristics in examine the consumer purchase intention.N/
Fungal vaccines and immunotherapeutics: current concepts and future challenges
Purpose of review The remarkable advances in modern medicine have paradoxically resulted in a rapidly expanding population of immunocompromised patients displaying extreme susceptibility to life-threatening fungal infections. There are currently no licensed vaccines, and the prophylaxis and therapy of fungal infections in at-risk individuals remains challenging, contributing to undesirable mortality and morbidity rates. The design of successful antifungal preventive approaches has been hampered by an insufficient understanding of the dynamics of the host-fungus interaction and the mechanisms that underlie heterogenous immune responses to vaccines and immunotherapy. Recent findings Recent advances in proteomics and glycomics have contributed to the identification of candidate antigens for use in subunit vaccines, novel adjuvants, and delivery systems to boost the efficacy of protective vaccination responses that are becoming available, and several targets are being exploited in immunotherapeutic approaches. Summary We review some of the emerging concepts as well as the inherent challenges to the development of fungal vaccines and immunotherapies to protect at-risk individuals.ThisworkwassupportedbytheNorthernPortugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER) (NORTE-01-0145-FEDER-000013), and the Fundação para a Ciência e Tecnologia (FCT) (contracts IF/00735/ 2014 to A.C., and SFRH/BPD/96176/2013 to C.C).info:eu-repo/semantics/publishedVersio
Seroprevalence of Toxoplasma gondii IgG antibody in HIV/AIDS-infected individuals in Maputo, Mozambique
Epidemiology, Species Distribution, Antifungal Susceptibility and Outcome of Nosocomial Candidemia in a Tertiary Care Hospital in Italy
Candida is an important cause of bloodstream infections (BSI), causing significant mortality and morbidity in health care settings. From January 2008 to December 2010 all consecutive patients who developed candidemia at San Martino University Hospital, Italy were enrolled in the study. A total of 348 episodes of candidaemia were identified during the study period (January 2008–December 2010), with an incidence of 1,73 episodes/1000 admissions. Globally, albicans and non-albicans species caused around 50% of the cases each. Non-albicans included Candida parapsilosis (28.4%), Candida glabrata (9.5%), Candida tropicalis (6.6%), and Candida krusei (2.6%). Out of 324 evaluable patients, 141 (43.5%) died within 30 days from the onset of candidemia. C. parapsilosis candidemia was associated with the lowest mortality rate (36.2%). In contrast, patients with C. krusei BSI had the highest mortality rate (55.5%) in this cohort. Regarding the crude mortality in the different units, patients in Internal Medicine wards had the highest mortality rate (54.1%), followed by patients in ICU and Hemato-Oncology wards (47.6%)
Prevalence of Abnormalities in Vestibular Function and Balance among HIV-Seropositive and HIV-Seronegative Women and Men
BACKGROUND: Most HIV-seropositive subjects in western countries receive highly active antiretroviral therapy (HAART). Although many aspects of their health have been studied, little is known about their vestibular and balance function. The goals of this study were to determine the prevalences of vestibular and balance impairments among HIV-seropositive and comparable seronegative men and women and to determine if those groups differed. METHODS: Standard screening tests of vestibular and balance function, including head thrusts, Dix-Hallpike maneuvers, and Romberg balance tests on compliant foam were performed during semiannual study visits of participants who were enrolled in the Baltimore and Washington, D. C. sites of the Multicenter AIDS Cohort Study and the Women's Interagency HIV Study. RESULTS: No significant differences by HIV status were found on most tests, but HIV-seropositive subjects who were using HAART had a lower frequency of abnormal Dix-Hallpike nystagmus than HIV-seronegative subjects. A significant number of nonclassical Dix-Hallpike responses were found. Age was associated with Romberg scores on foam with eyes closed. Sex was not associated with any of the test scores. CONCLUSION: These findings suggest that HAART-treated HIV infection has no harmful association with vestibular function in community-dwelling, ambulatory men and women. The association with age was expected, but the lack of association with sex was unexpected. The presence of nonclassical Dix-Hallpike responses might be consistent with central nervous system lesions
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