1,242 research outputs found
Quantum Isometries of the finite noncommutative geometry of the Standard Model
We compute the quantum isometry group of the finite noncommutative geometry F
describing the internal degrees of freedom in the Standard Model of particle
physics. We show that this provides genuine quantum symmetries of the spectral
triple corresponding to M x F where M is a compact spin manifold. We also prove
that the bosonic and fermionic part of the spectral action are preserved by
these symmetries.Comment: 29 pages, no figures v3: minor change
Aminosidine plus sodium stibogluconate for the treatment of Indian kala-azar: a randomized dose-finding clinical trial
This randomized, open sequential design trial was set up to assess the efficacy, tolerability and toxicity of 20 d courses of combined intramuscular aminosidine and sodium stibogluconate at various dosages in patients with newly-diagnosed kala-azar in Bihar, India. Three successive studies of 96 patients each were originally planned with aminosidine administered at 12, 6 and 3 mg/kg/d, respectively. For each aminosidine dosage, patients were randomly assigned to receive sodium stibogluconate at 20, 10 or 5 mg/kg/d of antimony. Ninety-six patients were enrolled and assigned aminosidine 12 mg/kg/d as scheduled. In the subsequent study with aminosidine at 6 mg/kg/d, the trial was interrupted after 40 patients had entered owing to inadequacy of the treatment. With aminosidine 12 mg/kg/d the success rates with sodium stibogluconate at 20, 10 and 5 mg/kg/d were 88%, 71% and 72%, respectively and did not differ significantly. With aminosidine 6 mg/kg/d, 69%, 50% and 46% of patients were cured with the same sodium stibogluconate doses, respectively; again, there was no significant difference between the subgroups. The overall success rate with aminosidine at 12 mg/kg/d (76%) was significantly higher than that with 6 mg/kg/d (55%) (odds ratio = 2·69; 95% confidence interval, 1·11-6·4). Patients improved clinically and the treatments were equally well tolerated. The combination of aminosidine 12 mg/kg/d and sodium stibogluconate 20 mg/kg/d for 20 d appears to be an effective and safe replacement in Bihar for sodium stibogluconate alone for ⩾40
Tripartite degrons confer diversity and specificity on regulated protein degradation in the ubiquitin-proteasome system
Specific signals (degrons) regulate protein turnover mediated by the ubiquitin-proteasome system. Here we systematically analyse known degrons and propose a tripartite model comprising the following: (1) a primary degron (peptide motif) that specifies substrate recognition by cognate E3 ubiquitin ligases, (2) secondary site(s) comprising a single or multiple neighbouring ubiquitinated lysine(s) and (3) a structurally disordered segment that initiates substrate unfolding at the 26S proteasome. Primary degron sequences are conserved among orthologues and occur in structurally disordered regions that undergo E3-induced folding-on-binding. Posttranslational modifications can switch primary degrons into E3-binding-competent states, thereby integrating degradation with signalling pathways. Degradation-linked lysines tend to be located within disordered segments that also initiate substrate degradation by effective proteasomal engagement. Many characterized mutations and alternative isoforms with abrogated degron components are implicated in disease. These effects result from increased protein stability and interactome rewiring. The distributed nature of degrons ensures regulation, specificity and combinatorial control of degradation. © 2016 Nature America, Inc
Roles of Government and Community Support, Flood Experience, and Flood Education in Livelihood Resilience
Flooding is a perennial problem in the state of Bihar, India with devastating impact on the livelihood of people. In spite of the government\u27s measures of flood mitigation, households continue to live with suffering on account of severe damage to their material and non-material assets. In this background, the objectives of the study are: (1) to explore the differential role of the community and government support in livelihood resilience; (2) to assess the impact of flood experience and flood education in livelihood resilience; and (3) to explore the impact of level of education, reflected in average years of schooling of the male-headed households in livelihood resilience. The primary data were collected from 472 households by using a multi-stage random sampling technique over seven blocks in river basins of Ganga and Kosi in the district of Bhagalpur, Bihar. To analyze the data, descriptive statistics and structural equation modeling were used. The findings of the study show that prompt and spontaneous community action was more effective than government help. Flood experience also plays a crucial role in the revamping of livelihood. Flood education is not found to exist in the area; people learn the skills of survival during and after floods from their elders. Moreover, difference in education among the male-headed households creates difference in the attitudes and awareness surrounding livelihood resilience
Expression of virulence genes in luminescent and nonluminescent isogenic vibrios and virulence towards gnotobiotic brine shrimp (<i>Artemia franciscana</i>)
Aims: This study aimed to evaluate the expression levels of virulence gene regulators (luxR and toxR) and virulence factors (serine protease, metalloprotease and haemolysin) in luminescent and nonluminescent isogenic Vibrio harveyi and Vibrio campbellii.Method and Results: Nonluminescent variants have been reported before to become dominant in cultures of luminescent vibrios when grown under static conditions in the dark. Wild-type V. harveyi BB120, V. campbellii LMG 21363, quorum sensing mutants of V. harveyi BB120 and their previously reported nonluminescent isogenic counterparts were used in this study. The expression level of the virulence genes srp serine protease, vhp metalloprotease and vhh haemolysin, the quorum sensing master regulator gene luxR and the virulence regulator gene toxR in isogenic luminescent and nonluminescent strains were quantified using reverse transcriptase real-time PCR. These experiments revealed that the nonluminescent strains produced lower levels of the quorum sensing master regulator gene luxR and the vhp metalloprotease gene (which is known to be regulated by quorum sensing). Finally, challenge tests with gnotobiotic brine shrimp (Artemia franciscana) larvae revealed that the nonluminescent strains are less virulent than their luminescent isogenic counterparts.Conclusion: Nonluminescent variants of V. harveyi and V. campbellii strains produce lower levels of the quorum sensing master regulator gene luxR and the vhp metalloprotease gene and are less virulent to brine shrimp than their isogenic luminescent counterparts.Significance and Impact of the study: These results indicate that adaptation of luminescent vibrios to specific growth conditions that result in a dominant nonluminescent phenotype is accompanied by a decreased adaptation to a host environment because of altered virulence gene regulation
Vefrifikacija prognoza oborine WRF modelom nad Indijom tijekom monsuna 2010.: CRA metoda
The WRF model forecast during monsoon season 2010 has been verified with daily observed gridded rainfall analysis with 0.5° spatial resolution. First- ly, the conventional neighborhood technique has been deployed to calculate common scores like mean error and root mean square error. Along with, widely used two categorical skill scores have been computed for seven different rainfall thresholds. The scores only found the general nature of the model performance and depicted the degradation of forecast accuracy exceeding moderate rainfall category of 7.5 mm. The object oriented Contiguous Rain Area method also has been considered for the verification of rainfall forecasts to gather more informa- tion about model performance. The method similarly has endorsed that the performance of the model degrades along with the increase in rainfall amount. But at the same time, the decomposition of mean square error has pointed out that the maximum error occurred due the shifting of rain object or event in the forecast compared to observation. The volume error contributes less as compared to pattern error in 24 hour forecasts irrespective of rainfall thresholds. But in 48 hour forecasts, their values are comparable and change along with rainfall threshold. During whole monsoon season, all contiguous rain areas in model forecasts have been searched over observed rainfall analyses applying best-fit criteria. For contiguous rain areas below 50 mm more than 70 percent match was found.Prognoza oborine dobivena modelom WRF za monsunsku sezonu 2010. verificirana je korištenjem analize dnevne opažene oborine u mreži prostorne rezolucije od 0,5°. Određeni su jednostavni, standardni pokazatelji poput srednje pogreške i srednje kvadratne pogreške, a također i dva uobičajena kategorička pokazatelja uspješnosti koji su izračunati za sedam različitih pragova oborine. Ti pokazatelji su omogućili općenitu procjenu uspješnosti modela te su ukazali na smanjenu pouzdanost za kategorije oborine veće od 7,5 mm. kako bi se detaljnije procijenila uspješnost modela, verifikacija prognoze oborine je također napravljena pomoću objektno orijentirane metode bliskih oborinskih područja CRA (Contiguous Rain Area). Ova metoda je također ukazala na smanjenje uspješnosti modela s povećanjem količine oborine. Međutim, dekompozicija srednje kvadratne pogreške je ukazala da najveću pogrešku uzrokuje pomak prognoziranog oborinskog područja ili događaja u odnosu na izmjerene vrijednosti. Za 24-satne prognoze volumna pogreška doprinosi manje u usporedbi s prostornom pogreškom, neovisno o pragovima oborine. Međutim, za 48-satne prognoze iznosi volumne i prostorne pogreške su usporedivi te rastu s pragom oborine. Susjedna oborinska područja za prognoziranu oborinu su određena obzirom na izmjerenu oborinu primjenom kriterija nabolje podudarnosti. Postupak je proveden za cijelu monsunsku sezonu. Za područja s količinom oborine manjom od 50 mm podudaranje je veće od 70%
Generalized Holographic Cosmology
We consider general black hole solutions in five-dimensional spacetime in the
presence of a negative cosmological constant. We obtain a cosmological
evolution via the gravity/gauge theory duality (holography) by defining
appropriate boundary conditions on a four-dimensional boundary hypersurface.
The standard counterterms are shown to renormalize the bare parameters of the
system (the four-dimensional Newton's constant and cosmological constant). We
discuss the thermodynamics of cosmological evolution and present various
examples. The standard brane-world scenarios are shown to be special cases of
our holographic construction.Comment: 15 pages, 5 figure
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