1,442 research outputs found
Pacific warm pool excitation, earth rotation and El Niño southern oscillations
2002-2003 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Non-perturbative effects and the refined topological string
The partition function of ABJM theory on the three-sphere has
non-perturbative corrections due to membrane instantons in the M-theory dual.
We show that the full series of membrane instanton corrections is completely
determined by the refined topological string on the Calabi-Yau manifold known
as local P1xP1, in the Nekrasov-Shatashvili limit. Our result can be
interpreted as a first-principles derivation of the full series of
non-perturbative effects for the closed topological string on this Calabi-Yau
background. Based on this, we make a proposal for the non-perturbative free
energy of topological strings on general, local Calabi-Yau manifolds.Comment: 38 pages, 5 figure
Bovine GDF10 gene polymorphism analysis and its association with body measurement traits in Chinese indigenous cattle
The objective of this research was to detect bovine GDF10 gene polymorphism and analyze its association with body measurement traits (BMT) of animals sampled from 6 different Chinese indigenous cattle populations. The populations included Xuelong (Xl), Luxi (Lx), Qinchuan (Qc), Jiaxian red (Jx), Xianang (Xn) and Nanyang (Ny). Blood samples were taken from a total of 417 female animals stratified into age categories of 12–36 months. Polymerase chain reaction–single strand conformation polymorphism (PCR–SSCP) was employed to find out GDF10 single polymorphism nucleotide (SNPs) and explore their possible association with BMT. Sequence analysis of GDF10 gene revealed 3 SNPs in total: 1 in exon1 (G142A) and 2 in exon3 (A11471G, and T12495C). G142A and T12495C SNPs are both synonymous mutation. They showed 2 genotypes namely respectively (GG, GA) and (PP and PB). A11471G SNP is a missense mutation leading to the change of Alanine to Threonine amino acid. It showed three genotypes namely AA, BB and AB. Analysis of association of polymorphism with body measurement traits at the three locus showed that there were significant effects on BMT in Qc, Jx and Ny cattle population. These results suggest that the GDF10 gene might have potential effects on body measurement traits in the above mentioned cattle populations and could be used for marker-assisted selection
Patient and prescriber perspectives on long-acting injectable (LAI) antipsychotics and analysis of in-office discussion regarding LAI treatment for schizophrenia
BACKGROUND: The research goal is to better understand prescriber, patient, and caregiver perspectives about long-acting injectable (LAI) antipsychotic therapy and how these perspectives affect LAI use. Addressing these perspectives in the clinic may lead to greater success in achieving therapeutic goals for the patient with schizophrenia. METHODS: Ethnographic information was collected from a non-random sample of 69 prescriber-patient conversations (60 with community mental health center [CMHC] psychiatrists; 9 with nurse-practitioners) recorded during treatment visits from August 2011 to February 2012, transcribed and analyzed. Discussions were categorized according to 11 predetermined CMHC topics. In-person observations were also conducted at 4 CMHCs, including home visits by researchers (n = 15 patients) prior to the CMHC visit and observations of patients receiving injections and interacting with staff. Telephone in-depth interviews with psychiatrists, patients, and caregivers to gather additional information on LAI discussion, prescription, or use were conducted. RESULTS: Antipsychotic treatment decisions were made without patient or caregiver input in 40 of 60 (67%) of psychiatrist-patient conversations. Involvement of patients or caregivers in treatment decisions was greater when discussing LAI (15 of 60 [25%]) vs oral antipsychotic treatment (5 of 60 [8%]). LAIs were not discussed by psychiatrists in 11 of 22 (50%) patients taking oral antipsychotics. When offered, more LAI-naïve patients expressed neutral (9 of 19 [47%]) rather than favorable (3 of 19 [16%]) or unfavorable (7 of 19 [37%]) responses. Prescribers were most concerned about potentially damaging the therapeutic relationship and side-effects when discussing LAIs while patient resistance was often related to negative feelings about injections. Psychiatrists had some success in overcoming patient objections to LAIs by addressing and decomposing initial resistance. More than half (11 of 19 [58%]) of LAI-naïve patients agreed to start LAI treatment following office visits. Patient-described benefits of LAIs vs orals included perceived rapid symptom improvement and greater overall efficacy. CONCLUSIONS: In this study, many psychiatrists did not offer LAIs and most patients and caregivers were not involved in antipsychotic treatment decision making. Opportunities to increase active patient engagement, address resistances, guide patient drug-formulation selection, and provide better LAI-relevant information for more individualized approaches to treating the patient with schizophrenia were present
Spatio-Temporal Characteristics of Global Warming in the Tibetan Plateau during the Last 50 Years Based on a Generalised Temperature Zone - Elevation Model
Temperature is one of the primary factors influencing the climate and ecosystem, and examining its change and fluctuation could elucidate the formation of novel climate patterns and trends. In this study, we constructed a generalised temperature zone elevation model (GTEM) to assess the trends of climate change and temporal-spatial differences in the Tibetan Plateau (TP) using the annual and monthly mean temperatures from 1961-2010 at 144 meteorological stations in and near the TP. The results showed the following: (1) The TP has undergone robust warming over the study period, and the warming rate was 0.318°C/decade. The warming has accelerated during recent decades, especially in the last 20 years, and the warming has been most significant in the winter months, followed by the spring, autumn and summer seasons. (2) Spatially, the zones that became significantly smaller were the temperature zones of -6°C and -4°C, and these have decreased 499.44 and 454.26 thousand sq km from 1961 to 2010 at average rates of 25.1% and 11.7%, respectively, over every 5-year interval. These quickly shrinking zones were located in the northwestern and central TP. (3) The elevation dependency of climate warming existed in the TP during 1961-2010, but this tendency has gradually been weakening due to more rapid warming at lower elevations than in the middle and upper elevations of the TP during 1991-2010. The higher regions and some low altitude valleys of the TP were the most significantly warming regions under the same categorizing criteria. Experimental evidence shows that the GTEM is an effective method to analyse climate changes in high altitude mountainous regions
MRPS18CP2 alleles and DEFA3 absence as putative chromosome 8p23.1 modifiers of hearing loss due to mtDNA mutation A1555G in the 12S rRNA gene
<p>Abstract</p> <p>Background</p> <p>Mitochondrial DNA (mtDNA) mutations account for at least 5% of cases of postlingual, nonsyndromic hearing impairment. Among them, mutation A1555G is frequently found associated with aminoglycoside-induced and/or nonsyndromic hearing loss in families presenting with extremely variable clinical phenotypes. Biochemical and genetic data have suggested that nuclear background is the main factor involved in modulating the phenotypic expression of mutation A1555G. However, although a major nuclear modifying locus was located on chromosome 8p23.1 and regardless intensive screening of the region, the gene involved has not been identified.</p> <p>Methods</p> <p>With the aim to gain insights into the factors that determine the phenotypic expression of A1555G mutation, we have analysed in detail different genetic and genomic elements on 8p23.1 region (<it>DEFA3 </it>gene absence, <it>CLDN23 </it>gene and <it>MRPS18CP2 </it>pseudogene) in a group of 213 A1555G carriers.</p> <p>Results</p> <p>Family based association studies identified a positive association for a polymorphism on <it>MRPS18CP2 </it>and an overrepresentation of <it>DEFA3 </it>gene absence in the deaf group of A1555G carriers.</p> <p>Conclusion</p> <p>Although none of the factors analysed seem to have a major contribution to the phenotype, our findings provide further evidences of the involvement of 8p23.1 region as a modifying locus for A1555G 12S rRNA gene mutation.</p
c-erbB-2 is not a major factor in the development of colorectal cancer
We have investigated c-erbB-2 protein expression in a large cohort of well-characterized colorectal tumours, and in a subset of lymph node metastases. We have also evaluated a Val655Ile single nucleotide polymorphism, which is associated with an increased risk of breast cancer, in a subset of the colorectal cancer patients and in healthy control subjects. Immunohistochemical studies revealed that while 81.8% of tumours expressed c-erbB-2, in the majority of cases equivalent levels of c-erb-B2 were seen in adjacent normal mucosa. Colon tumours were significantly more likely to express c-erbB-2 than rectal tumours (P=0.015). Only 52.4% of the metastases displayed staining patterns concordant with their primary tumour, indicating that determination of c-erbB-2 protein in colorectal tumours cannot predict the status of lymph node metastases. PCR–RFLP analysis of the Val655Ile single nucleotide polymorphism demonstrated that allele frequencies were identical between colorectal cancer patients and a control group of Caucasian subjects (Ile=0.80 and Val=0.20 in each case), indicating that it is not related to the risk of developing colorectal cancer in this population. Furthermore, there was no relationship between c-erbB-2 protein expression and gene polymorphism (P=0.58). In terms of prognosis, no association was seen between either c-erbB-2 protein expression or the presence of the Val allele and patient survival (P>0.05 in each case), suggesting that c-erbB-2 is not a prognostic marker in colorectal cancer
Inadequate glucose control in type 2 diabetes is associated with impaired lung function and systemic inflammation: a cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Inadequate glucose control may be simultaneously associated with inflammation and decreased lung function in type 2 diabetes. We evaluated if lung function is worse in patients with inadequate glucose control, and if inflammatory markers are simultaneously increased in these subjects.</p> <p>Methods</p> <p>Subjects were selected at the Colombian Diabetes Association Center in Bogotá. Pulmonary function tests were performed and mean residual values were obtained for forced expiratory volume (FEV<sub>1)</sub>, forced vital capacity (FVC) and FEV<sub>1</sub>/FVC, with predicted values based on those derived by Hankinson et al. for Mexican-Americans. Multiple least-squares regression was used to adjust for differences in known determinants of lung function. We measured blood levels of glycosylated hemoglobin (HBA<sub>1c</sub>), interleukin 6 (IL-6), tumor necrosis factor (TNF-α), fibrinogen, ferritin, and C-reactive protein (C-RP).</p> <p>Results</p> <p>495 diabetic patients were studied, out of which 352 had inadequate control (HBA<sub>1c </sub>> 7%). After adjusting for known determinants of lung function, those with inadequate control had lower FEV<sub>1 </sub>(-75.4 mL, IC95%: -92, -59; P < 0.0001) and FVC (-121 mL, IC95%: -134, -108; P < 0,0001) mean residuals, and higher FEV<sub>1</sub>/FVC (0.013%, IC95%: 0.009, 0.018, P < 0.0001) residuals than those with adequate control, as well as increased levels of all inflammatory markers (P < 0.05), with the exception of IL-6.</p> <p>Conclusions</p> <p>Subjects with type 2 diabetes and inadequate control had lower FVC and FEV<sub>1 </sub>than predicted and than those of subjects with adequate control. It is postulated that poorer pulmonary function may be associated with increased levels of inflammatory mediators.</p
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