5,353 research outputs found
The Technicolor Higgs in the Light of LHC Data
We consider scenarios in which the 125 GeV resonance observed at the Large
Hadron Collider is a Technicolor (TC) isosinglet scalar, the TC Higgs. By
comparison with quantum chromodynamics, we argue that the couplings of the TC
Higgs to the massive weak bosons are very close to the Standard Model (SM)
values. The couplings to photons and gluons are model-dependent, but close to
the SM values in several TC theories. The couplings of the TC Higgs to SM
fermions are due to interactions beyond TC, such as Extended Technicolor: if
such interactions successfully generate mass for the SM fermions, we argue that
the couplings of the latter to the TC Higgs are also SM-like.
We suggest a generic parameterization of the TC Higgs interactions with SM
particles that accommodates a large class of TC models, and we perform a fit of
these parameters to the Higgs LHC data. The fit reveals regions of parameter
space where the form factors are of order unity and consistent with data at the
95% CL, in agreement with expectations in TC theories. This indicates that the
discovered Higgs boson is consistent with the TC Higgs hypothesis for several
TC theories.Comment: 26 pages, 8 figure
Electrochemical Tuning of the Dielectric Function of Au Nanoparticles
The tunable dielectric response of Au nanoparticles under electrochemical bias can be interpreted in terms of changes in the surface charge density, surface damping, and the near-surface volume fraction of the nanoparticles that experience a modified dielectric function, as well as changes in the index of refraction of the surrounding electrolyte medium. Using experimental bias-dependent extinction measurements, we derive a potential-dependent dielectric function for Au nanoparticles that accounts for changes in the physical properties contributing to the optical extinction
Building capacity for dissemination and implementation research: One universityâs experience
Abstract Background While dissemination and implementation (D&I) science has grown rapidly, there is an ongoing need to understand how to build and sustain capacity in individuals and institutions conducting research. There are three inter-related domains for capacity building: people, settings, and activities. Since 2008, Washington University in St. Louis has dedicated significant attention and resources toward building D&I research capacity. This paper describes our process, challenges, and lessons with the goal of informing others who may have similar aims at their own institution. Activities An informal collaborative, the Washington University Network for Dissemination and Implementation Research (WUNDIR), began with a small group and now has 49 regular members. Attendees represent a wide variety of settings and content areas and meet every 6Â weeks for half-day sessions. A logic model organizes WUNDIR inputs, activities, and outcomes. A mixed-methods evaluation showed that the network has led to new professional connections and enhanced skills (e.g., grant and publication development). As one of four, ongoing, formal programs, the Dissemination and Implementation Research Core (DIRC) was our first major component of D&I infrastructure. DIRCâs mission is to accelerate the public health impact of clinical and health services research by increasing the engagement of investigators in later stages of translational research. The aims of DIRC are to advance D&I science and to develop and equip researchers with tools for D&I research. As a second formal component, the Washington University Institute for Public Health has provided significant support for D&I research through pilot projects and a small grants program. In a third set of formal programs, two R25 training grants (one in mental health and one in cancer) support post-doctoral scholars for intensive training and mentoring in D&I science. Finally, our team coordinates closely with D&I functions within research centers across the university. We share a series of challenges and potential solutions. Conclusion Our experience in developing D&I research at Washington University in St. Louis shows how significant capacity can be built in a relatively short period of time. Many of our ideas and ingredients for success can be replicated, tailored, and improved upon by others
The Use of Public Funds for Private Benefit: An Examination of the Relationship between Public Stadium Funding and Ticket Prices in the National Football League
During the past decade there has been a proliferation of sports stadia being built in Americaâs municipal districts. While it used to be common for the public to fully fund stadium construction projects, over the past 20 years factors such as political motives, tax reform, and increased public awareness of tax equity have forced sports teams to share increasing amounts of the financial burden (Crompton, Howard, & Var, 2003). As public funding for stadia construction has decreased, franchises have continued to strive for maximized profits. Concurrently, the cost of attending events in sports stadia has increased for consumers in terms of higher ticket prices even though changes in fixed costs should not affect pricing (Leeds & von Allmen, 2004). The purpose of this study was to examine the relationship between the use of public funds to build stadia and the profit maximizing goals of National Football League (NFL) franchises. A hypothesis was formulated that stated the impact of the public share of the construction cost would have no effect on relative ticket prices for those that consume the product. The cross-sectional data for a ticket price model, which consisted of seasonal data from every NFL team to play from 1991 through 2003, was investigated. The results showed an increase in public funding by 10% lowers ticket prices by 42 cents. As shown, the bulk of the variation in ticket prices was due to a general increase over time and MSA per capita income
Mitochondrial dysfunction and oxidative stress in patients with chronic kidney disease.
Mitochondria abnormalities in skeletal muscle may contribute to frailty and sarcopenia, commonly present in patients with chronic kidney disease (CKD). Dysfunctional mitochondria are also a major source of oxidative stress and may contribute to cardiovascular disease in CKD We tested the hypothesis that mitochondrial structure and function worsens with the severity of CKD Mitochondrial volume density, mitochondrial DNA (mtDNA) copy number, BNIP3, and PGC1α protein expression were evaluated in skeletal muscle biopsies obtained from 27 subjects (17 controls and 10 with CKD stage 5 on hemodialysis). We also measured mtDNA copy number in peripheral blood mononuclear cells (PBMCs), plasma isofurans, and plasma F2-isoprostanes in 208 subjects divided into three groups: non-CKD (eGFR>60 mL/min), CKD stage 3-4 (eGFR 60-15 mL/min), and CKD stage 5 (on hemodialysis). Muscle biopsies from patients with CKD stage 5 revealed lower mitochondrial volume density, lower mtDNA copy number, and higher BNIP3 content than controls. mtDNA copy number in PBMCs was decreased with increasing severity of CKD: non-CKD (6.48, 95% CI 4.49-8.46), CKD stage 3-4 (3.30, 95% CI 0.85-5.75, P = 0.048 vs. non-CKD), and CKD stage 5 (1.93, 95% CI 0.27-3.59, P = 0.001 vs. non-CKD). Isofurans were higher in patients with CKD stage 5 (median 59.21 pg/mL, IQR 41.76-95.36) compared to patients with non-CKD (median 49.95 pg/mL, IQR 27.88-83.46, P = 0.001), whereas F2-isoprostanes did not differ among groups. Severity of CKD is associated with mitochondrial dysfunction and markers of oxidative stress. Mitochondrial abnormalities, which are common in skeletal muscle from patients with CKD stage 5, may explain the muscle dysfunction associated with frailty and sarcopenia in CKD Further studies are required to evaluate mitochondrial function in vivo in patients with different CKD stages
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Anatomic Fat Depots and Coronary Plaque Among Human Immunodeficiency Virus-Infected and Uninfected Men in the Multicenter AIDS Cohort Study.
Methods. âIn a cross-sectional substudy of the Multicenter AIDS Cohort Study, noncontrast cardiac computed tomography (CT) scanning for coronary artery calcium (CAC) scoring was performed on all men, and, for men with normal renal function, coronary CT angiography (CTA) was performed. Associations between fat depots (visceral adipose tissue [VAT], abdominal subcutaneous adipose tissue [aSAT], and thigh subcutaneous adipose tissue [tSAT]) with coronary plaque presence and extent were assessed with logistic and linear regression adjusted for age, race, cardiovascular disease (CVD) risk factors, body mass index (BMI), and human immunodeficiency virus (HIV) parameters. Results. âAmong HIV-infected men (n = 597) but not HIV-uninfected men (n = 343), having greater VAT was positively associated with noncalcified plaque presence (odds ratio [OR] = 1.04, P < .05), with a significant interaction (P < .05) by HIV serostatus. Human immunodeficiency virus-infected men had lower median aSAT and tSAT and greater median VAT among men with BMI <25 and 25-29.9 kg/m(2). Among HIV-infected men, VAT was positively associated with presence of coronary plaque on CTA after adjustment for CVD risk factors (OR = 1.04, P < .05), but not after additional adjustment for BMI. There was an inverse association between aSAT and extent of total plaque among HIV-infected men, but not among HIV-uninfected men. Lower tSAT was associated with greater CAC and total plaque score extent regardless of HIV serostatus. Conclusions. âThe presence of greater amounts of VAT and lower SAT may contribute to increased risk for coronary artery disease among HIV-infected persons
Structure and dielectric response in the high ferroelectric Bi(Zn,Ti)O-PbTiO solid solutions
Theoretical {\em ab initio} and experimental methods were used to investigate
the Bi(Zn,Ti)O-(1-)PbTiO (BZT-PT) solid solution. We find that
hybridization between Zn 4 and O 2 orbitals allows the formation of
short, covalent Zn-O bonds, enabling favorable coupling between A-site and
B-site displacements. This leads to large polarization, strong tetragonality
and an elevated ferroelectric to paraelectric phase transition temperature.
nhomogeneities in local structure near the 90 domain boundaries can be
deduced from the asymetric peak broadening in the neutron and x-ray diffraction
spectra. These extrinsic effects make the ferroelectric to paraelectric phase
transition diffuse in BZT-PT solid solutions
Combined analysis of microbial metagenomic and metatranscriptomic sequencing data to assess in situ physiological conditions in the premature infant gut.
Microbes alter their transcriptomic profiles in response to the environment. The physiological conditions experienced by a microbial community can thus be inferred using meta-transcriptomic sequencing by comparing transcription levels of specifically chosen genes. However, this analysis requires accurate reference genomes to identify the specific genes from which RNA reads originate. In addition, such an analysis should avoid biases in transcript counts related to differences in organism abundance. In this study we describe an approach to address these difficulties. Sample-specific meta-genomic assembled genomes (MAGs) were used as reference genomes to accurately identify the origin of RNA reads, and transcript ratios of genes with opposite transcription responses were compared to eliminate biases related to differences in organismal abundance, an approach hereafter named the "diametric ratio" method. We used this approach to probe the environmental conditions experienced by Escherichia spp. in the gut of 4 premature infants, 2 of whom developed necrotizing enterocolitis (NEC), a severe inflammatory intestinal disease. We analyzed twenty fecal samples taken from four premature infants (4-6 time points from each infant), and found significantly higher diametric ratios of genes associated with low oxygen levels in samples of infants later diagnosed with NEC than in samples without NEC. We also show this method can be used for examining other physiological conditions, such as exposure to nitric oxide and osmotic pressure. These study results should be treated with caution, due to the presence of confounding factors that might also distinguish between NEC and control infants. Nevertheless, together with benchmarking analyses, we show here that the diametric ratio approach can be applied for evaluating the physiological conditions experienced by microbes in situ. Results from similar studies can be further applied for designing diagnostic methods to detect NEC in its early developmental stages
Variable Ticket Pricing in Major League Baseball
Sport teams historically have been reluctant to change ticket prices during the season. Recently, however, numerous sport organizations have implemented variable ticket pricing in an effort to maximize revenues. In Major League Baseball variable pricing results in ticket price increases or decreases depending on factors such as quality of the opponent, day of the week, month of the year, and for special events such as opening day, Memorial Day, and Independence Day. Using censored regression and elasticity analysis, this article demonstrates that variable pricing would have yielded approximately 1.4 million in revenue. The largest percentage revenue gain would have been the San Francisco Giants. The Giants would have seen an estimated 6.7% increase in revenue had they used optimal variable pricing
Text mining the food security literature reveals substantial spatial bias and thematic broadening over time
We conducted text mining analyses on nearly the entirety of academic literature related to food security. Assessing the literature\u27s spatial scope, we found a truly global body of research conducted across 187 different countries, but with significant spatial heterogeneities in where research is conducted. Comparing the spatial distribution of the literature to actual rates of food insecurity, we found only a slight association between where food security research is conducted and where food security needs are located. Using topic modeling to assess the thematic scope of the literature, we found that originally food security research focused on economic policy and global issues, and only later did the literature expand to encompass themes like livelihoods, health, and the environment. This analysis provides the first ever thematic scoping of the entire food security literature and the first assessment of spatial biases in where food security research is conducted
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