47 research outputs found
Measuring the growth of structure with multi-wavelength surveys of galaxy clusters
No full textCurrent and near-future galaxy cluster surveys at a variety of wavelengths are expected to provide a promising way to obtain precision measurements of the growth of structure over cosmic time. This in turn would serve as an important precision probe of cosmology. However, to realize the full potential of these surveys, systematic uncertainties arising from, for example, cluster mass estimates and sample selection must be well understood. This work follows several different approaches towards alleviating these uncertainties.
Cluster sample selection is investigated in the context of arcminute-resolution millimeter-wavelength surveys such as the Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT). Large-area, realistic simulations of the microwave sky are constructed and cluster detection is simulated using a multi-frequency Wiener filter to separate the galaxy clusters, via their Sunyaev-Zel'dovich signal, from other contaminating microwave signals. Using this technique, an ACT-like survey can expect to obtain a cluster sample that is 90% complete and 85% pure above a mass of 3 x 10^14 Msun.
Cluster mass uncertainties are explored by comparing X-ray and weak-lensing mass estimates for shear-selected galaxy clusters in the Deep Lens Survey (DLS) to study possible biases in using cluster baryons or weak-lensing shear as tracers of the cluster total mass. Results are presented for four galaxy clusters that comprise the top-ranked shear-selected system in the DLS, and for three of these clusters there is agreement between X-ray and weak-lensing mass estimates. For the fourth cluster, the X-ray mass estimate is higher than that from weak-lensing by 2-sigma, and X-ray images suggest this cluster may be undergoing a merger with a smaller cluster, which may be biasing the X-ray mass estimate high.
The feasibility of measuring galaxy cluster peculiar velocities using an ACT-like instrument is also investigated. Such a possibility would allow one to measure structure growth via large-scale velocity fields and circumvent the uncertainties associated with measuring cluster masses. We show that such measurements are possible and yield statistical uncertainties of roughly 100 km/sec given either a temperature prior with 1-sigma errors of less than 2 keV or additional lower frequency millimeter-band observations.Ph.D.Includes bibliographical references
PLoS Pathog
No full textMycobacterium tuberculosis (Mtb) remains a major public health problem, with an effective vaccine continuing to prove elusive. Progress in vaccination strategies has been hampered by a lack of appreciation of the bacterium's response to dynamic changes in the host immune environment. Here, we utilize reporter Mtb strains that respond to specific host immune stresses such as hypoxia and nitric oxide (hspX'::GFP), and phagosomal maturation (rv2390c'::GFP), to investigate vaccine-induced alterations in the environmental niche during experimental murine infections. While vaccination undoubtedly decreased bacterial burden, we found that it also appeared to accelerate Mtb's adoption of a phenotype better equipped to survive in its host. We subsequently utilized a novel replication reporter strain of Mtb to demonstrate that, in addition to these alterations in host stress response, there is a decreased percentage of actively replicating Mtb in vaccinated hosts. This observation was supported by the differential sensitivity of recovered bacteria to the front-line drug isoniazid. Our study documents the natural history of the impact that vaccination has on Mtb's physiology and replication and highlights the value of reporter Mtb strains for probing heterogeneous Mtb populations in the context of a complex, whole animal model.20141DP2LM011952-01/DP/NCCDPHP CDC HHS/United StatesAI067027/AI/NIAID NIH HHS/United StatesDP2 LM011952/LM/NLM NIH HHS/United StatesHL055936/HL/NHLBI NIH HHS/United StatesR01 AI067027/AI/NIAID NIH HHS/United StatesR01 HL055936/HL/NHLBI NIH HHS/United States25233380PMC41695031018
TRANSCRIPTIONAL REGULATION AND PROTECTIVE EFFICACY OF BORDETELLA COLONIZATION FACTOR A (BcfA) IN BORDETELLA INFECTIONS
No full textTo successfully colonize their mammalian hosts many bacteria produce multiple virulence factors that play essential roles in disease processes and pathogenesis. Some of these molecules are adhesins that allow efficient attachment to host cells, a prerequisite for successful host colonization. Bordetella spp. express a number of proteins which either play a direct role in attachment to the respiratory epithelia or exhibit similarity to previously known bacterial adhesins. One such recently identified protein is BipA. Despite similarity to intimins and invasins, its deletion from B. bronchiseptica did not result in any significant defect in respiratory tract colonization. We hypothesized the existence of a paralogous protein that could complement the function of BipA. In the studies described here, we report the identification and characterization of an ORF in B. bronchiseptica, designated as bcfA (Bordetella colonization factor A) that is similar to bipA. We show that in contrast to maximal expression of bipA in the Bvgi phase, bcfA is expressed at high levels in both the Bvg+ and the Bvgi phases. We have identified multiple sequence elements resembling the consensus BvgA binding site in the bcfA promoter region. Direct binding of purified BvgA to the bcfA promoter revealed differences in the DNA binding profiles of BvgA and BvgA-P to the promoter region. Utilizing an antibody raised against BcfA, we show that BcfA is localized in the outer membrane. Finally, we demonstrate that simultaneous deletion of both bipA and bcfA results in a defect in colonization of the rat trachea and that BcfA is expressed during Bordetella infectious cycle.
Based on our findings that BcfA is an outer membrane immunogenic protein and is critical for murine respiratory tract colonization, we examined its utility in inducing a protective immune response against B. bronchiseptica in a mouse model of intranasal infection. Mice vaccinated with BcfA demonstrated reduced pathology in the lungs and harbored lower bacterial burdens in the respiratory tract. Immunization with BcfA led to the generation of BcfA-specific antibodies in both the serum and the lungs and passive immunization led to the reduction of B. bronchiseptica in the trachea and the lungs. These results suggest that protection after immunization with BcfA is mediated in part by antibodies against BcfA. To further investigate the mechanism of BcfA-induced immune clearance, we examined the role of neutrophils and macrophages. Our results demonstrate that neutrophils are critical for anti-BcfA antibody-mediated clearance and that opsonization with anti-BcfA serum enhances phagocytosis of B. bronchiseptica by murine macrophages. We show that immunization with BcfA results in the production of IFN-γ and subclasses of IgG antibodies that are consistent with the induction of a Th1 type immune response. In combination, our findings suggest that mechanism of BcfA-mediated immunity involves humoral and cellular responses. Expression of BcfA is conserved among multiple clinical isolates of B. bronchiseptica. Our results demonstrate the striking protective efficacy of BcfA-mediated immunization thereby highlighting its utility as a potential vaccine candidate. These results also provide a model for the development of cell-free vaccines against B. bronchiseptica
Mycobacterium tuberculosis Responds to Chloride and pH as Synergistic Cues to the Immune Status of its Host Cell
No full textPubMed ID: 23592993This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Reforming institutions for service delivery : a framework for development assistance with an application to the health, nutrition, and population portfolio
No full textWorld Development Report 1997: The State in a Changing World (report no. 17300) argued that institutions-the rules of the game that govern production and exchange-shape a country's prospects for sustained market-led growth. The author provides an institutional framework for service delivery, an essential component of state capability. He applies this framework to an evaluation of Bank support for service delivery in the health, nutrition, and population sector. He argues for greater institutional pluralism in the ways the World Bank does business in infrastructure, rural, and social sectors, but cautions against making efficient service delivery an issue of"state versus market."The Bank and its clients face the challenge of fitting menus of"better practice"delivery options to maps of institutional reality. In the health, nutrition, and population sector, the Bank should (1) unbundle and categorize essential health and clinical services according to goods characteristics and (2) integrate country knowledge into operations through upstream assessments of state, political, and social institutions. Overall, the Bank has made progress toward a"goods characteristics"approach, particularly in infrastructure and some rural services-but it has lagged in the social sectors, where support remains largely technocratic. Cross-sector comparisons reveal four generations of support for service delivery. First-generation support focused mainly on physical implementation of projects. Second-generation interventions, which characterized most social service interventions, focused on improving the financial and organizational viability of implementing agencies through technical assistance. Third-generation support was marked by significant unbundling of service delivery activities and clearer links to goods characteristics. In irrigation (1982-94), telecommunications (1980s-present), and transport (1990s), the one-size-fits-all monopoly model gave way to a range of options based on greater private sector and citizen participation in delivery. These included leases, concessions, outsourcing, and contracting as well as building, operating, transfer, and turnover schemes. Fourth-generation interventions are works-in-progress and represent efforts to develop new governance arrangements that systematically combine competition, voice, and hierarchy in the design, delivery, and monitoring of Bank projects. The Bank has a poor track record building country knowledge of institutional endowments that affect service delivery. The author identifies concepts and tools valuable for sector specialists'operations.Enterprise Development&Reform,Public Health Promotion,Health Economics&Finance,Decentralization,Health Monitoring&Evaluation,Governance Indicators,Poverty Assessment,Environmental Economics&Policies,Health Monitoring&Evaluation,Health Economics&Finance
Optimized Round Robin CPU Scheduling Algorithm
No full textOne of the fundamental function of an operating system is scheduling. There are 2 types of uni-processor operating system in general. Those are uni-programming and multi-programming. Uni-programming operating system execute only single job at a time while multiprogramming operating system is capable of executing multiple jobs concurrently. Resource utilization is the basic aim of multiprogramming operating system. There are many scheduling algorithms available for multi-programming operating system. But our work focuses on design and development aspect of new and novel scheduling algorithm for multi-programming operating system in the view of optimization. We developed a tool which gives output in the form of experimental results with respect to some standard and new scheduling algorithms e.g. First come first serve, shortest job first, round robin, optimal and a novel cpu scheduling algorithm etc
Performance Assessment of TMOs
No full textAbstractHigh dynamic range (HDR) imaging has gained momentum with the growth in digital photography technology. In this paper, performance assessment of various tone mapping techniques has been presented. HDR images were used and Tone Mapping Operators (TMOs) such as Gamma Correction, Reinhard, Drago, Ashkmin were applied to generate Low Dynamic Range (LDR) images. After that, LDR images are rated using objective assessment parameters such as luminance, mean, MSE and mPSNR. A new modified Ashikmin TMO is reported in this work. The results have shown that modified Ashikhmin has generated better LDR image than other TMOs. In addition, the profiles of objective performance assessment were also included to compare the usability of TMOs for generating better LDR images
Building blocks of Cwebs in multiparton scattering amplitudes
No full textThe correlators of Wilson-line operators in non-abelian gauge theories are known to exponentiate, and their logarithms can be organised in terms of the collections of Feynman diagrams called Cwebs. The colour factors that appear in the logarithm correspond to completely connected diagrams and are determined by the web mixing matrices. In this article we introduce several new concepts: (a) Normal ordering of the diagrams of a Cweb, (b) Fused-Webs (c) Basis and Family of Cwebs. We use these ideas together with a Uniqueness theorem that we prove to arrive at an understanding of the diagonal blocks, and several null matrices that appear in the mixing matrices. We demonstrate using our formalism that, once the basis Cwebs present upto order αsn are determined, the number of exponentiated colour factors for several classes of Cwebs starting at order αsn+1 can be predicted. We further provide complete results for the mixing matrices, to all orders in perturbation theory, for two special classes of Cwebs using our framework. © 2022, The Author(s)
Assessing Self-Care Perception in Patients Living with Type 2 Diabetes and Their Physicians
No full textThe general metadata -- e.g., title, author, abstract, subject headings, etc. -- is publicly available, but access to the submitted files is restricted to UT Southwestern campus access and/or authorized UT Southwestern users.BACKGROUND: Type 2 diabetes mellitus (T2D) is chronic illness affecting millions in the United States. Patients living with T2D require highly individualized care and significant patient effort. This effort is comprised of the patient's self-care with regards to medication, diet, lifestyle, and mental health. Self-efficacy is a patient's ability to feel agency over their illness and therefore feel able to maintain self-care. Previous literature suggests that improving a patient's self-efficacy through various behavioral health interventions may improve a patient's ability to manage their T2D. Additionally, interventions on self-efficacy are thought to work regardless of health literacy level and might be a generalizable intervention. However, while validated surveys assessing patient diabetes distress, quality-of-life, social determinants of health, adverse childhood events, and more exist, no literature was found attempting to understand a patient's perspective on their self-care, and by extension, their self-efficacy. Under the premise that consistent beliefs between patient and physician regarding self-care are necessary to make meaningful plans promoting self-care and self-efficacy, the authors developed the term self-care perception consistency to assess relationship between patient and physician perceptions of a patient's self-care.
OBJECTIVE: The objective is to assess the consistency between patient and physician perceptions of patient self-care through a biopsychosocial and structural/social determinants of health lens.
METHODS: This study uses a cross-sectional, quantitative data set obtained by the Research Residency Network of Texas (RRNeT) through a 71-item survey study. This survey was completed across 12 Family Medicine residencies in Texas and included individuals between 18-75 who were living with T2D. Responses ranged from short free response to Likert-scale based questions and covered topics such as demographics, social determinants of health, patient self-care, diabetes distress, quality-of-life, adverse childhood events, and more. The physicians of each patient were asked to complete a shorter 10-item survey with broader analogous questions to the patient survey. This data was collected through RedCap and analyzed through RStudio.
RESULTS: The term self-care perception consistency was coined to describe the relationship between the patient's and physician's perception of the patient's self-care. Self-care perception consistency was found to be lacking 31.2% of the time. Only HgA1c (p<0.01) was inversely correlated with self-care perception consistency in both the univariate and multivariate analyses of demographic factors and social determinants of health. Additional analysis was completed to assess the relationship of HgA1c control, patient diabetes distress, patient quality-of-life, and the physician survey with self-care perception consistency. Self-care perception consistent and inconsistent groups were found to have significantly different HgA1c control distributions (p < 0.01) in the subset of patients that rated their self-care positively, but no significant difference was found in the group that rated their self-care negatively. Patient self-care ratings were best correlated with their diabetes distress (p<0.01) and HgA1c (p<0.01) while physician ratings of patient self-care were best correlated with their perception of HgA1c, perception of patient diabetes distress, perception of patient quality-of-life, and perception of patient social connectedness (p<0.01 for all). Notably, trending diabetes distress, quality-of-life, the physician survey, and social determinants of health across patient self-care ratings in self-care perception consistent versus inconsistent groups revealed that only the physician survey showed opposite trends across the consistent and inconsistent groups.
CONCLUSION: Self-care perception consistency was found to be lacking 31.2% of the time. Notably, HgA1c is correlated with patient and physician perceptions of patient self-care (p<0.01 for both); however, in instances of patient-physician self-care perception inconsistency, HgA1c is not correlated with patient self-care perception. Instead, diabetes distress remains predictive of patient self-care rating in all instances (p<0.01). Patient-physician self-care perception inconsistency is also associated with inconsistency in patient and physician perceptions of the patient's diabetes distress. As diabetes distress remains consistently correlated with patient self-care rating, using the validated diabetes distress survey-17 with an additional question regarding self-care may help physicians better understand patients and therefore target appropriate education and psychosocial interventions
Exploitation of Mycobacterium tuberculosis reporter strains to probe the impact of vaccination at sites of infection.
No full textMycobacterium tuberculosis (Mtb) remains a major public health problem, with an effective vaccine continuing to prove elusive. Progress in vaccination strategies has been hampered by a lack of appreciation of the bacterium's response to dynamic changes in the host immune environment. Here, we utilize reporter Mtb strains that respond to specific host immune stresses such as hypoxia and nitric oxide (hspX'::GFP), and phagosomal maturation (rv2390c'::GFP), to investigate vaccine-induced alterations in the environmental niche during experimental murine infections. While vaccination undoubtedly decreased bacterial burden, we found that it also appeared to accelerate Mtb's adoption of a phenotype better equipped to survive in its host. We subsequently utilized a novel replication reporter strain of Mtb to demonstrate that, in addition to these alterations in host stress response, there is a decreased percentage of actively replicating Mtb in vaccinated hosts. This observation was supported by the differential sensitivity of recovered bacteria to the front-line drug isoniazid. Our study documents the natural history of the impact that vaccination has on Mtb's physiology and replication and highlights the value of reporter Mtb strains for probing heterogeneous Mtb populations in the context of a complex, whole animal model
