185 research outputs found
Resolving the and anomalies with leptoquarks and a dark Higgs boson
At present, there are outstanding discrepancies between standard model
predictions and measurements of the muon's and several -meson
properties. We resolve these anomalies by considering a two-Higgs-doublet model
extended to include leptoquarks and a dark Higgs boson . The leptoquarks
modify -meson decays and also induce an coupling, which
contributes to the muon's through a Barr-Zee diagram. We show that, for
TeV-scale leptoquarks and dark Higgs boson masses , a consistent resolution to all of the anomalies exists. The
model predicts interesting new decays, such as , , , and , with branching fractions not far below current bounds.Comment: 25 pages, 7 figures. Matches published versio
Resolving the (g-2)μ and B anomalies with leptoquarks and a dark Higgs boson
© 2020 authors. Published by the American Physical Society. At present, there are outstanding discrepancies between standard model predictions and measurements of the muon\u27s g-2 and several B-meson properties. We resolve these anomalies by considering a two-Higgs-doublet model extended to include leptoquarks and a dark Higgs boson S. The leptoquarks modify B-meson decays and also induce an Sγγ coupling, which contributes to the muon\u27s g-2 through a Barr-Zee diagram. We show that, for TeV-scale leptoquarks and dark Higgs boson masses mS∼10-200 MeV, a consistent resolution to all of the anomalies exists. The model predicts interesting new decays, such as B→K(∗)e+e-, B→K(∗)γγ, K→πγγ, and h→γγγγ, with branching fractions not far below current bounds
Digital control of force microscope cantilevers using a field programmable gate array
This report describes a cantilever controller for magnetic resonance force
microscopy (MRFM) based on a field programmable gate array (FPGA), along with
the hardware and software used to integrate the controller into an experiment.
The controller is assembled from a low-cost commercially available software
defined radio (SDR) device and libraries of open-source software. The
controller includes a digital filter comprising two cascaded second-order
sections ("biquads"), which together can implement transfer functions for
optimal cantilever controllers. An appendix in this report shows how to
calculate filter coefficients for an optimal controller from measured
cantilever characteristics. The controller also includes an input multiplexer
and adder used in calibration protocols. Filter coefficients and multiplexer
settings can be set and adjusted by control software while an experiment is
running. The input is sampled at 64 MHz; the sampling frequency in the filters
can be divided down under software control to achieve a good match with filter
characterisics. Data reported here were sampled at 500 kHz, chosen for acoustic
cantilevers with resonant frequencies near 8 kHz. Inputs are digitized with 12
bits resolution, outputs with 14 bits. The experiment software is organized as
a client and server to make it easy to adapt the controller to different
experiments. The server encapusulates the details of controller hardware
organization, connection technology, filter architecture, and number
representation. The same server could be used in any experiment, while a
different client encodes the particulars of each experiment.Comment: submitted to Review of Scientific Instrument
Are social organizational factors independently associated with a current bacterial sexually transmitted infection among urban adolescents and young adults?
This study explored the relationship between the social organization of neighborhoods including informal social control and social cohesion and a current bacterial sexually transmitted infection (STI) among adolescents and young adults in one U.S. urban setting. Data for the current study were collected from April 2004 to April 2007 in a cross-sectional household study. The target population included English-speaking, sexually-active persons between the ages of 15 and 24 years who resided in 486 neighborhoods. The study sample included 599 participants from 63 neighborhoods. A current bacterial STI was defined as diagnosis of a chlamydia and/or gonorrhea infection at the time of study participation. Participants reported on informal social control (i.e. scale comprised of 9 items) and social cohesion (i.e. scale comprised of 5 items) in their neighborhood. In a series of weighted multilevel logistic regression models stratified by gender, greater informal social control was significantly associated with a decreased odds of a current bacterial STI among females (AOR 0.53, 95% CI 0.34, 0.84) after controlling for individual social support and other factors. The association, while in a similar direction, was not significant for males (AOR 0.73, 95% CI 0.48, 1.12). Social cohesion was not significantly associated with a current bacterial STI among females (OR 0.85, 95% CI 0.61, 1.19) and separately, males (OR 0.98, 95% CI 0.67, 1.44). Greater individual social support was associated with an almost seven-fold increase in the odds of a bacterial STI among males (AOR 6.85, 95% CI 1.99, 23.53), a finding which is in contrast to our hypotheses. The findings suggest that neighborhood social organizational factors such as informal social control have an independent relationship with sexual health among U.S. urban youth. The causality of the relationship remains to be determined
Validation of Messenger Ribonucleic Acid Markers Differentiating Among Human Acute Respiratory Distress Syndrome Subgroups in an Ovine Model of Acute Respiratory Distress Syndrome Phenotypes
BACKGROUND: The discovery of biological subphenotypes in acute respiratory distress syndrome (ARDS) might offer a new approach to ARDS in general and possibly targeted treatment, but little is known about the underlying biology yet. To validate our recently described ovine ARDS phenotypes model, we compared a subset of messenger ribonucleic acid (mRNA) markers in leukocytes as reported before to display differential expression between human ARDS subphenotypes to the expression in lung tissue in our ovine ARDS phenotypes model (phenotype 1 (Ph1): hypoinflammatory; phenotype 2 (Ph2): hyperinflammatory). METHODS: We studied 23 anesthetized sheep on mechanical ventilation with observation times between 6 and 24 h. They were randomly allocated to the two phenotypes (n = 14 to Ph1 and n = 9 to Ph2). At study end, lung tissue was harvested and preserved in RNAlater. After tissue homogenization in TRIzol, total RNA was extracted and custom capture and reporter probes designed by NanoString Technologies were used to measure the expression of 14 genes of interest and the 6 housekeeping genes on a nCounter SPRINT profiler. RESULTS: Among the 14 mRNA markers, in all animals over all time points, 13 markers showed the same trend in ovine Ph2/Ph1 as previously reported in the MARS cohort: matrix metalloproteinase 8, olfactomedin 4, resistin, G protein-coupled receptor 84, lipocalin 2, ankyrin repeat domain 22, CD177 molecule, and transcobalamin 1 expression was higher in Ph2 and membrane metalloendopeptidase, adhesion G protein-coupled receptor E3, transforming growth factor beta induced, histidine ammonia-lyase, and sulfatase 2 expression was higher in Ph1. These expression patterns could be found when different sources of mRNA – such as blood leukocytes and lung tissue – were compared. CONCLUSION: In human and ovine ARDS subgroups, similar activated pathways might be involved (e.g., oxidative phosphorylation, NF-κB pathway) that result in specific phenotypes
A hidden problem: peripheral artery disease in women
Peripheral artery disease (PAD) has a huge social and economic burden and is an important contributor to the global health burden. Sex differences in PAD are apparent, with recent data suggesting equal if not greater prevalence in women, and women having worse clinical outcomes. Why this occurs is not clear. To identify underlying reasons for gender inequalities in PAD, we executed a deeper exploration through a social constructive perspective. A scoping review was conducted using the World Health Organization model for analysis of gender-related needs in healthcare. Complex interacting factors, including biological, clinical, and societal variables, were reviewed to highlight gender-related inequities in the diagnosis, treatment, and management of PAD. Current gaps in knowledge were identified and insights into future directions aimed at improving these inequalities were discussed. Our findings highlight the multi-level complexities that need to be considered for strategies to improve gender-related needs in PAD healthcare
Endothelial cell dysfunction: Implications for the pathogenesis of peripheral artery disease
Peripheral artery disease (PAD) is caused by occluded or narrowed arteries that reduce blood flow to the lower limbs. The treatment focuses on lifestyle changes, management of modifiable risk factors and vascular surgery. In this review we focus on how Endothelial Cell (EC) dysfunction contributes to PAD pathophysiology and describe the largely untapped potential of correcting endothelial dysfunction. Moreover, we describe current treatments and clinical trials which improve EC dysfunction and offer insights into where future research efforts could be made. Endothelial dysfunction could represent a target for PAD therapy
Sex, Endothelial Cell Functions, and Peripheral Artery Disease
Peripheral artery disease (PAD) is caused by blocked arteries due to atherosclerosis and/or thrombosis which reduce blood flow to the lower limbs. It results in major morbidity, including ischemic limb, claudication, and amputation, with patients also suffering a heightened risk of heart attack, stroke, and death. Recent studies suggest women have a higher prevalence of PAD than men, and with worse outcomes after intervention. In addition to a potential unconscious bias faced by women with PAD in the health system, with underdiagnosis, and lower rates of guideline-based therapy, fundamental biological differences between men and women may be important. In this review, we highlight sexual dimorphisms in endothelial cell functions and how they may impact PAD pathophysiology in women. Understanding sex-specific mechanisms in PAD is essential for the development of new therapies and personalized care for patients with PAD
- …