Mapping our Universe in 3D with MITEoR

Mapping our universe in 3D by imaging the redshifted 21 cm line from neutral hydrogen has the potential to overtake the cosmic microwave background as our most powerful cosmological probe, because it can map a much larger volume of our Universe, shedding new light on the epoch of reionization, inflation, dark matter, dark energy, and neutrino masses. We report on MITEoR, a pathfinder low-frequency radio interferometer whose goal is to test technologies that greatly reduce the cost of such 3D mapping for a given sensitivity. MITEoR accomplishes this by using massive baseline redundancy both to enable automated precision calibration and to cut the correlator cost scaling from N^2 to NlogN, where N is the number of antennas. The success of MITEoR with its 64 dual-polarization elements bodes well for the more ambitious HERA project, which would incorporate many identical or similar technologies using an order of magnitude more antennas, each with dramatically larger collecting area.Comment: To be published in proceedings of 2013 IEEE International Symposium on Phased Array Systems & Technolog

Sanitation and Hygiene Practices in Small Towns in Tanzania: The Case of Babati District, Manyara Region.

Formative research findings from the fast-growing Babati town were used to assess the prevalence of sanitation and hygiene practices among individuals and institutions and associated factors. A cross-sectional study involving household surveys, spot-checks, focus group discussions, in-depth interviews, and structured observations of behaviors showed that 90% of households have sanitation facilities, but 68% have safely managed sanitation services. The most common types of household sanitation facilities were pit latrines with slab (42%) followed by flush/pour flush toilets (32%). Therefore, the management of wastewater depends entirely on onsite sanitation systems. The majority of households (70%) do not practice proper hygiene behaviors. Thirteen percent of the households had handwashing stations with soap and water, handwashing practice being more common to women (38%) than men (18%). The reported handwashing practices during the four critical moments (handwashing with soap before eating and feeding, after defecation, after cleaning child's bottom, and after touching any dirt/dust) differed from the actual/observed practices. Households connected to the town's piped water supply were more likely to practice handwashing than those not directly connected. Sanitation and hygiene behaviors of the people in the study area were seen to be influenced by sociodemographic, cultural, and economic factors. The conditions of sanitation and hygiene facilities in public places were unsatisfactory. There is an urgent need to ensure that the sanitation and hygiene services and behaviors along the value chain (from waste production/source to disposal/end point) are improved both at the household level and in public places through improved sanitation services and the promotion of effective hygiene behavior change programs integrated into ongoing government programs and planning

Critical Transition in Tissue Homeostasis Accompanies Murine Lung Senescence

BACKGROUND: Respiratory dysfunction is a major contributor to morbidity and mortality in aged populations. The susceptibility to pulmonary insults is attributed to "low pulmonary reserve", ostensibly reflecting a combination of age-related musculoskeletal, immunologic and intrinsic pulmonary dysfunction. METHODS/PRINCIPAL FINDINGS: Using a murine model of the aging lung, senescent DBA/2 mice, we correlated a longitudinal survey of airspace size and injury measures with a transcriptome from the aging lung at 2, 4, 8, 12, 16 and 20 months of age. Morphometric analysis demonstrated a nonlinear pattern of airspace caliber enlargement with a critical transition occurring between 8 and 12 months of age marked by an initial increase in oxidative stress, cell death and elastase activation which is soon followed by inflammatory cell infiltration, immune complex deposition and the onset of airspace enlargement. The temporally correlative transcriptome showed exuberant induction of immunoglobulin genes coincident with airspace enlargement. Immunohistochemistry, ELISA analysis and flow cytometry demonstrated increased immunoglobulin deposition in the lung associated with a contemporaneous increase in activated B-cells expressing high levels of TLR4 (toll receptor 4) and CD86 and macrophages during midlife. These midlife changes culminate in progressive airspace enlargement during late life stages. CONCLUSION/SIGNIFICANCE: Our findings establish that a tissue-specific aging program is evident during a presenescent interval which involves early oxidative stress, cell death and elastase activation, followed by B lymphocyte and macrophage expansion/activation. This sequence heralds the progression to overt airspace enlargement in the aged lung. These signature events, during middle age, indicate that early stages of the aging immune system may have important correlates in the maintenance of tissue morphology. We further show that time-course analyses of aging models, when informed by structural surveys, can reveal nonintuitive signatures of organ-specific aging pathology

Combinatorial Probes for High-Throughput Electrochemical Analysis of Circulating Nucleic Acids in Clinical Samples

The analysis of circulating tumour nucleic acids (ctNAs) provides a minimally invasive way to assess the mutational spectrum of a tumour. However, effective and practical methods for analyzing this emerging class of markers are lacking. Analysis of ctNAs using a sensor-based approach has notable challenges, as it is vital to differentiate nucleic acids from normal cells from mutation-bearing sequences emerging from tumours. Moreover, many genes related to cancer have dozens of different mutations. Herein, we report an electrochemical approach that directly detects genes with mutations in patient serum by using combinatorial probes (CPs). The CPs enable detection of all of the mutant alleles derived from the same part of the gene. As a proof of concept, we analyze mutations of the EGFR gene, which has more than 40 clinically relevant alterations that include deletions, insertions, and point mutations. Our CP-based approach accurately detects mutant sequences directly in patient serum.Research reported in this publication was supported by the Province of Ontario though the Ministry of Research, Innovation and Science (Grant #RE05-009), the Canadian Institutes of Health Research (Emerging Team Grant #RMF-111625), the Canadian Cancer Society Research Institute (Grant #70241), and the Natural Sciences and Engineering Research Council of Canada (Grant #2016-06090). The opinions, results and conclusions are solely the responsibility of the authors and no endorsement by the funding agencies is intended or inferred

High-Curvature Nanostructuring Enhances Probe Display for Biomolecular Detection

High-curvature electrodes facilitate rapid and sensitive detection of a broad class of molecular analytes. These sensors have reached detection limits not attained using bulk macroscale materials. It has been proposed that immobilized DNA probes are displayed at a high deflection angle on the sensor surface, which allows greater accessibility and more efficient hybridization. Here we report the first use of all-atom molecular dynamics simulations coupled with electrochemical experiments to explore the dynamics of single-stranded DNA immobilized on high-curvature versus flat surfaces. We find that high-curvature structures suppress DNA probe aggregation among adjacent probes. This results in conformations that are more freely accessed by target molecules. The effect observed is amplified in the presence of highly charged cations commonly used in electrochemical biosensing. The results of the simulations agree with experiments that measure the degree of hybridization in the presence of mono-, di-, and trivalent cations. On high-curvature structures, hybridization current density increases as positive charge increases, whereas on flat electrodes, the trivalent cations cause aggregation due to electrostatic overscreening, which leads to decreased current density and less sensitive detection

Steric Hindrance Assay for Secreted Factors in Stem Cell Culture

The ex vivo expansion of hematopoietic stem cells is significantly inhibited by secreted proteins that induce negative feedback loops. The ability to effectively monitor these factors is critical for their real-time regulation and control and, by extension, enhancing stem cell expansion. Here, we describe a novel monitoring strategy for the detection of soluble signaling factors in stem cell cultures using a DNA-based sensing mechanism on a chip-based nanostructured microelectrode platform. We combine DNA hybridization engineering with antibody-capturing chemistry in an amplified steric hindrance hybridization assay. This method enables the quantification of important secreted proteins, showcased by the detection of 10 pg·mL^–1 level concentrations of three proteins in stem cell culture samples. This approach is the first universal nonsandwich technique that permits pg·mL^–1 level quantification of small proteins in stem cell culture media without signal loss

“We want everything in a one-stop shop”: acceptability and feasibility of PrEP and buprenorphine implementation with mobile syringe services for Black people who inject drugs

Abstract Introduction A recent surge in HIV outbreaks, driven by the opioid and stimulant use crises, has destabilized our progress toward targets set forth by Ending the HIV Epidemic: A Plan for America for the high-priority community of people who inject drugs (PWID), particularly Black PWID. Methods In order to ascertain the acceptability and feasibility of using a mobile syringe services program (SSP) for comprehensive HIV prevention via PrEP and medications for opioid use disorder (MOUD), our mixed methods approach included a quantitative assessment and semi-structured qualitative interviews with Black PWID (n = 30) in Miami-Dade County who were actively engaged in mobile syringe services. Results Participants felt that delivery of MOUD and PrEP at a mobile SSP would be both feasible and acceptable, helping to address transportation, cost, and stigma barriers common within traditional healthcare settings. Participants preferred staff who are compassionate and nonjudgmental and have lived experience. Conclusions A mobile harm reduction setting could be an effective venue for delivering comprehensive HIV prevention services to Black PWID, a community that experiences significant barriers to care via marginalization and racism in a fragmented healthcare system

Rapid Identification and Investigation of an HIV Risk Network Among People Who Inject Drugs –Miami, FL, 2018

Prevention of HIV outbreaks among people who inject drugs remains a challenge to ending the HIV epidemic in the United States. The first legal syringe services program (SSP) in Florida implemented routine screening in 2018 leading to the identification of ten anonymous HIV seroconversions. The SSP collaborated with the Department of Health to conduct an epidemiologic investigation. All seven acute HIV seroconversions were linked to care (86% within 30 days) and achieved viral suppression (mean 70 days). Six of the seven individuals are epidemiologically and/or socially linked to at least two other seroconversions. Analysis of the HIV genotypes revealed that two individuals are connected molecularly at 0.5% genetic distance. We identified a risk network with complex transmission dynamics that could not be explained by epidemiological methods or molecular analyses alone. Providing wrap-around services through the SSP, including routine screening, intensive linkage and patient navigation, could be an effective model for achieving viral suppression for people who inject drugs