2,483 research outputs found
Deformations and D-branes
I discuss the relation of Hochschild cohomology to the physical states in the
closed topological string. This allows a notion of deformation intrinsic to the
derived category. I use this to identify deformations of a quiver gauge theory
associated to a D-branes at a singularity with generalized deformations of the
geometry of the resolution of the singularity. An explicit map is given from
noncommutative deformations (ie, B-fields) to terms in the superpotential.Comment: 33 pages, uses utarticle.cls, dcpic.sty; v2: minor corrections and
refs adde
The fungal frontier
A report of the 24th Fungal Genetics Conference, Asilomar, USA, 20-25 March 2007
A Case of Highly Aggressive Extraskeletal Myxoid Chondrosarcoma
Extraskeletal myxoid chondrosarcoma (EMC) is a soft tissue malignancy characterized by specific chromosomal abnormalities involving the TEC gene. This disease has historically been considered largely indolent both histologically and clinically. Rarer subsets of EMC exist that demonstrate aggressive histopathologic features and clinical behavior, though it remains unclear whether or not aggressive histopathology is predictive of outcome. Herein we present a case of EMC with aggressive histopathologic features that underwent rapid clinical progression despite initial treatment with curative intent. This case provides the context for a discussion of the existing literature regarding treatment, prognosis, pathology, and genetic/molecular features of EMC in general and aggressive EMC specifically
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An Examination of Motivation to Change and Neural Alcohol Cue Reactivity Following a Brief Intervention.
Background: Brief interventions represent a promising psychological intervention targeting individuals with heavy alcohol use. Motivation to change represents an individual's openness to engage in a behavior change strategy and is thought to be a crucial component of brief interventions. Neuroimaging techniques provide a translational tool to investigate the neurobiological mechanisms underlying potential mediators of treatment response, including motivation to change. Therefore, this study aimed to examine the effect of a brief intervention on motivation to change drinking behavior and neural alcohol taste cue reactivity. Methods: Non-treatment-seeking heavy drinkers were randomized to receive a brief drinking intervention (n = 22) or an attention-matched control (n = 24). Three indices of motivation to change were assessed at baseline and after the intervention or control session: importance, confidence, and readiness. Immediately following the intervention or control session, participants also underwent an functional magnetic resonance imaging (fMRI) during which they completed an alcohol taste cues paradigm. Results: There was a significant effect of the brief intervention on increasing ratings of importance of changing drinking behavior, but not on ratings of confidence or readiness to change. Ratings of importance after the intervention or control session were associated with neural alcohol taste cue reactivity, but notably, this effect was only significant for participants who received the intervention. Individuals in the intervention condition showed a positive association between ratings of importance and activation in the precuneus, posterior cingulate, and insula. Conclusions: The brief drinking intervention was successful at improving one dimension of motivation to change among non-treatment-seeking heavy drinkers. The brief intervention moderated the relationship between ratings of importance and brain activation in circuitry associated with interoceptive awareness and self-reflection. Together, findings represent an initial step toward understanding the neurobiological mechanisms through which a brief intervention may improve motivation to change
Financial Relationships With Industry Among National Comprehensive Cancer Network Guideline Authors
Financial conflicts of interest (FCOIs) among authors of clinical practice guidelines have the potential to influence treatment recommendations. To quantify FCOIs with industry among authors of the National Comprehensive Cancer Network (NCCN) guidelines. We assessed FCOIs occurring during 2014 among NCCN guideline authors in the United States. All were physician members of the NCCN guideline committees for lung, breast, prostate, and colorectal cancer as of the end of 2014. The data source for FCOIs was Open Payments, which is publically reported by the Centers for Medicare and Medicaid Services. This study was cross-sectional. The proportion of NCCN authors having FCOIs with industry; the average amount received from industry sources per author. Of 125 guideline authors, 108 (86%) had at least 1 reported FCOI. Authors received an average of 0-236 066 (range 2 756 713) in industry research payments (RPs), including funding associated with clinical trials. Approximately 84% of authors received GPs, while 47% received RPs. Eight (6%) had FCOIs in excess of the 20 000 single-company maximums stipulated by NCCN. Among NCCN guideline authors, FCOIs involving RPs were of greater value, while those involving GPs were more prevalent. Although FCOIs may result from engaging in important scholarship, FCOIs may still influence guideline authors in counterproductive ways. Research is needed to understand how best to manage author FCOIs during guideline creation
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Roles of Candida albicans Mig1 and Mig2 in glucose repression, pathogenicity traits, and SNF1 essentiality.
Metabolic adaptation is linked to the ability of the opportunistic pathogen Candida albicans to colonize and cause infection in diverse host tissues. One way that C. albicans controls its metabolism is through the glucose repression pathway, where expression of alternative carbon source utilization genes is repressed in the presence of its preferred carbon source, glucose. Here we carry out genetic and gene expression studies that identify transcription factors Mig1 and Mig2 as mediators of glucose repression in C. albicans. The well-studied Mig1/2 orthologs ScMig1/2 mediate glucose repression in the yeast Saccharomyces cerevisiae; our data argue that C. albicans Mig1/2 function similarly as repressors of alternative carbon source utilization genes. However, Mig1/2 functions have several distinctive features in C. albicans. First, Mig1 and Mig2 have more co-equal roles in gene regulation than their S. cerevisiae orthologs. Second, Mig1 is regulated at the level of protein accumulation, more akin to ScMig2 than ScMig1. Third, Mig1 and Mig2 are together required for a unique aspect of C. albicans biology, the expression of several pathogenicity traits. Such Mig1/2-dependent traits include the abilities to form hyphae and biofilm, tolerance of cell wall inhibitors, and ability to damage macrophage-like cells and human endothelial cells. Finally, Mig1 is required for a puzzling feature of C. albicans biology that is not shared with S. cerevisiae: the essentiality of the Snf1 protein kinase, a central eukaryotic carbon metabolism regulator. Our results integrate Mig1 and Mig2 into the C. albicans glucose repression pathway and illuminate connections among carbon control, pathogenicity, and Snf1 essentiality
Statin cost effectiveness in primary prevention a systematic review of the recent cost-effectiveness literature in the United States
AbstractBackgroundThe literature on the cost-effectiveness of statin drugs in primary prevention of coronary heart disease is complex. The objective of this study is to compare the disparate results of recent cost-effectiveness analyses of statins.FindingsWe conducted a systematic review of the literature on statin cost-effectiveness. The four studies that met inclusion criteria reported varying conclusions about the cost-effectiveness of statin treatment, without a clear consensus as to whether statins are cost-effective for primary prevention. However, after accounting for each study’s assumptions about statin costs, we found substantial agreement among the studies. Studies that assumed statins to be more expensive found them to be less cost-effective, and vice-versa. Furthermore, treatment of low-risk groups became cost-effective as statins became less expensive.ConclusionsDrug price is the primary determinant of statin cost-effectiveness within a given risk group. As more statin drugs become generic, patients at low risk for coronary disease may be treated cost-effectively. Though many factors must be weighed in any medical decision, from a cost-effectiveness perspective, statins may now be considered an appropriate therapy for many patients at low risk for heart disease
The cancer premium – explaining differences in prices for cancer vs non-cancer drugs with efficacy and epidemiological endpoints in the US, Germany, and Switzerland: a cross sectional study
Background: High treatment prices of new cancer drugs are a global public health challenge to patients and healthcare systems. Policymakers in the US and Europe are debating reforms to drug pricing. The objective of this study was to assess whether drug efficacy or epidemiological characteristics (prevalence, incidence, mortality) explain the gap in treatment prices between cancer and non-cancer drugs in the US, Germany, and Switzerland.
Methods: This cross-sectional study identified all new drugs approved in the US, Germany, and Switzerland between 2011 and 2020. Drug efficacy was extracted from pivotal trials, drug prices from public and commercial databases, and epidemiological characteristics from the Global Burden of Disease (GBD) 2019 study. We used regression models to explain drug prices with drug efficacy and epidemiological characteristics (prevalence, incidence, mortality).
Findings: The cohort included 181 drugs, including 68 (37.5%) drugs approved for treatment of cancer. A significant negative correlation was found between incidence/prevalence and treatment prices, and a significant positive correlation was observed between mortality and treatment prices for both, cancer and non-cancer drugs. A significant association between relative drug efficacy and treatment prices of drugs was observed, however, less pronounced for cancer drugs. Our regression estimates indicated that after adjusting for efficacy and epidemiological characteristics, cancer drugs were on average approximately three times more expensive compared to non-cancer drugs in all three countries, indicating a cancer premium; i.e., treatment prices of cancer drugs were on average USD 74,412 (95% CI [62,810; 86,015]) more expensive in the US compared to non-cancer drugs, USD 37,770 (95% CI [26,175; 49,367]) more expensive in Germany, and USD 32,801 (95% CI [27,048; 38,555]) more expensive in Switzerland. Our model explained 72% of the variance in observed prices (R2).
Interpretation: Drug pricing reforms should target the cancer premium to improve access of patients to cancer drugs as well as to achieve equity across the different therapeutic areas and sustainability in the health care systems
Insect resistance of a full sib family of tetraploid switchgrass \u3ci\u3ePanicum virgatum\u3c/i\u3e L. with varying lignin levels
Little information is available on insect resistance mechanisms and inheritance in biomass grasses. Although reduction of lignin in biomass grasses in order to increase the efficiency of fermentation may result in increased susceptibility to insect feeding, other resistance mechanisms may be more important. Field grown leaves of two tetraploid parent (Kanlow N1, Summer) and 14 progeny switchgrass (Panicum virgatum L.) plant clones selected for a diversity of plant form and ranges in lignin levels were tested for leaf resistance to feeding by the fall armyworm (Spodoptera frugiperda J. E. Smith), a grass feeding insect pest. Although lignin generally appeared important as a resistance mechanism only at early season stages, replicate clones of two low lignin progeny plants generally remained resistant to fall armyworm feeding. Mechanical damaging increased resistance to fall armyworm feeding in several of these plants. Degrees of resistance were sometimes associated with leaf form of progeny. These results indicate there are likely multiple insect resistance mechanisms operating at different stages in switchgrass, and that segregation of some mechanisms appears related to growth form of the plants
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