HIV antiretroviral therapy and prevention use in US blood donors: a new blood safety concern.

Antiretroviral therapy (ART) to treat and pre-exposure prophylaxis (PrEP) to prevent HIV infection are effective tools to help end the HIV epidemic. However, their use could affect HIV transfusion-transmission risk. Three different ART/PrEP prevalence analyses in blood donors were conducted. First, blood samples from HIV-positive and a comparison group of infection-nonreactive donors were tested under blind using liquid chromatography-tandem mass spectrometry for ART. Second, blood donor samples from infection-nonreactive, 18- to 45-year-old, male, first-time blood donors in 6 US locations were tested for emtricitabine and tenofovir. Third, in men who have sex with men (MSM) participating in the 2017 Centers for Disease Control and Prevention National HIV Behavioral Surveillance (NHBS) from 5 US cities, self-reported PrEP use proximate to donation was assessed. In blind testing, no ART was detected in 300 infection-nonreactive donor samples, but in 299 HIV confirmed-infected donor samples, 46 (15.4%; 95% confidence interval [CI], 11.5% to 20.0%) had evidence of ART. Of the 1494 samples tested from first-time male donors, 9 (0.6%; 95% CI, 0.03% to 1.1%) had tenofovir and emtricitabine. In the NHBS MSM survey, 27 of 591 respondents (4.8%; 95% CI, 3.2% to 6.9%) reported donating blood in 2016 or 2017 and PrEP use within the same time frame as blood donation. Persons who are HIV positive and taking ART and persons taking PrEP to prevent HIV infection are donating blood. Both situations could lead to increased risk of HIV transfusion transmission if blood screening assays are unable to detect HIV in donations from infected donors.

Temporal multispectral and 3D analysis of Cerro de Pasco, Peru.

Mining operations across the world often lead to contamination of land, water resources, ecosystems and in some cases, entire communities.Results of recent health and ground sampling studies revealed extensive lead contamination within the populace and around the City of Cerro de Pasco, Peru. Tailings excavated from a large open pit zinc mine in the center of the city have been aggregated in four large stockpiles within close proximity to neighborhoods, schools, and hospitals. Visual comparison of ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) imagery from 2001 and Sentinel-2 imagery from 2018 suggests a size increase in one tailing stockpile in particular near the neighborhood of Paragsha. Due to ongoing mining efforts, the hypothesis motivating the work presented here is that Pb-bearing minerals would be detectable through multispectral analysis, an increase in Pb mineral percent abundance would be observed and tailing stockpile volume would be detectable between 2001 and 2016. This hypothesis is tested using Spectral Angle Mapper (SAM), Adaptive Coherence Estimator (ACE), and Jeffries-Matusita distance calculation on ASTER (2001) and Sentinel-2 (2018) VNIR and SWIR bands. Volume and area estimate of tailing stockpiles were calculated using a photogrammetrically derived point cloud. SAM detected the presence of five Pb-bearing minerals around Cerro de Pasco and Paragsha. The results of the temporal SAM analysis displayed an increase of approximately 17% of Pb-bearing minerals around the greater Cerro de Pasco city area and approximately 11% for the neighborhood of Paragsha. Jeffries-Matusita distance results suggest clear correlation between contamination sources and affected locations. Total tailing stockpile volume was measured to be approximately 200,300,000 m3. Volume for Pile 4 was estimated to have increased by approximately 46,000,000 m3 between 2001 and 2018. These presented results will hopefully inspire and guide future remote sensing campaigns, perhaps involving a UAV or aircraft-based hyperspectral instrument.

Demonstration of Machine Learning-Based Model-Independent Stabilization of Source Properties in Synchrotron Light Sources.

Synchrotron light sources, arguably among the most powerful tools of modern scientific discovery, are presently undergoing a major transformation to provide orders of magnitude higher brightness and transverse coherence enabling the most demanding experiments. In these experiments, overall source stability will soon be limited by achievable levels of electron beam size stability, presently on the order of several microns, which is still 1-2 orders of magnitude larger than already demonstrated stability of source position and current. Until now source size stabilization has been achieved through corrections based on a combination of static predetermined physics models and lengthy calibration measurements, periodically repeated to counteract drift in the accelerator and instrumentation. We now demonstrate for the first time how the application of machine learning allows for a physics- and model-independent stabilization of source size relying only on previously existing instrumentation. Such feed-forward correction based on a neural network that can be continuously online retrained achieves source size stability as low as 0.2 µm (0.4%) rms, which results in overall source stability approaching the subpercent noise floor of the most sensitive experiments.

Suppression of epithelial-mesenchymal transition and apoptotic pathways by miR-294/302 family synergistically blocks let-7-induced silencing of self-renewal in embryonic stem cells.

The embryonic stem cell (ESC)-enriched miR-294/302 family and the somatic cell-enriched let-7 family stabilizes the self-renewing and differentiated cell fates, respectively. The mechanisms underlying these processes remain unknown. Here we show that among many pathways regulated by miR-294/302, the combinatorial suppression of epithelial-mesenchymal transition (EMT) and apoptotic pathways is sufficient in maintaining the self-renewal of ESCs. The silencing of ESC self-renewal by let-7 was accompanied by the upregulation of several EMT regulators and the induction of apoptosis. The ectopic activation of either EMT or apoptotic program is sufficient in silencing ESC self-renewal. However, only combined but not separate suppression of the two programs inhibited the silencing of ESC self-renewal by let-7 and several other differentiation-inducing miRNAs. These findings demonstrate that combined repression of the EMT and apoptotic pathways by miR-294/302 imposes a synergistic barrier to the silencing of ESC self-renewal, supporting a model whereby miRNAs regulate complicated cellular processes through synergistic repression of multiple targets or pathways.

Donor-specific cell-based assays in studying sensitivity to low-dose radiation: a population-based perspective.

Currently, a linear no-threshold model is used to estimate health risks associated with exposure to low-dose radiation, a prevalent exposure in the general population, because the direct estimation from epidemiological studies suffers from uncertainty. This model has been criticized based on unique biology of low-dose radiation. Whether the departure from linearity is toward increased or decreased risk is intensely debated. We present an approach based on individual radiosensitivity testing and discuss how individual radiosensitivity can be assessed with the goal to develop a quantifiable measure of cellular response that can be conducted via high-throughput population testing.

Effects of oral D-ribose supplementation on anaerobic capacity and selected metabolic markers in healthy males.

Oral D-ribose supplementation has been reported to increase adenine nucleotide synthesis and exercise capacity in certain clinical populations. Theoretically, increasing adenine nucleotide availability may enhance high intensity exercise capacity. This study evaluated the potential ergogenic value of D-ribose supplementation on repetitive high-intensity exercise capacity in 19 trained males. Subjects were familiarized to the testing protocol and performed two practice-testing trials before pre-supplementation testing. Each test involved warming up for 5 min on a cycle ergometer and then performing two 30-s Wingate anaerobic sprint tests on a computerized cycle ergometer separated by 3 min of rest recovery. In the pre- and post-supplementation trials, blood samples were obtained at rest, immediately following the first and second sprints, and following 5 min of recovery from exercise. Subjects were then matched according to body mass and anaerobic capacity and assigned to ingest, in a randomized and double blind manner, capsules containing either 5 g of a dextrose placebo (P) or D-ribose (R) twice daily (10 g/d) for 5 d. Subjects then performed post-supplementation tests on the 6th day. Data were analyzed by ANOVA for repeated measures. Results revealed a significant interaction (p =.04) in total work output. Post hoc analysis revealed that work significantly declined (-18 +/- 51 J) during the second post-supplementation sprint in the P group while being maintained in the R group (-0.0 +/- 31 J). No significant interactions were observed in peak power, average power, torque, fatigue index, lactate, ammonia, glucose, or uric acid. Results indicate that oral ribose supplementation (10 g/d for 5 d) does not affect anaerobic exercise capacity or metabolic markers in trained subjects as evaluated in this study.

Expression of connexin 43 mRNA and protein in developing follicles of prepubertal porcine ovaries.

A major form of cell-cell communication is mediated by gap junctions, aggregations of intercellular channels composed of connexins (Cxs), which are responsible for exchange of low molecular weight (<1200 Da) cytosolic materials. These channels are a growing family of related proteins. This study was designed to determine the ontogeny of connexin 43 (Cx43) during early stages of follicular development in prepubertal porcine ovaries. A partial-length (412 base) cDNA clone was obtained from mature porcine ovaries and determined to have 98% identity with published porcine Cx43. Northern blot analysis demonstrated a 4.3-kb mRNA in total RNA isolated from prepubertal and adult porcine ovaries. In-situ hybridization revealed that Cx43 mRNA was detectable in granulosa cells of primary follicles but undetectable in dormant primordial follicles. The intensity of the signal increased with follicular growth and was greatest in the large antral follicles. Immunohistochemical evaluation indicated that Cx43 protein expression correlated with the presence of Cx43 mRNA. These results indicate that substantial amounts of Cx43 are first expressed in granulosa cells following activation of follicular development and that this expression increases throughout follicular growth and maturation. These findings suggest an association between the enhancement of intercellular gap-junctional communication and onset of follicular growth.

Immigrant women's health.

The immigration process entails many changes in the lives of those who emigrate including establishing oneself in a new country. There is continuing interest in what happens to the health of those who undergo this process. This qualitative study investigated the perceived health and health-related experiences of a sample of mid-life immigrant women and explored relationships between determinants of health and their experiences connected to immigration. Forty-two women participated in the study. While respondents were relatively well educated, their current socioeconomic status was relatively low. While women defined their health in a holistic manner. personal health focused on their physical health and their ability to function. This functionality was closely related to women's roles as resources for their families' well-being. Several health-related themes were identified that related to their change in homelands as adults: immigration and health, adapting to immigration and rebuilding their lives. Women are unlikely to talk about non-physical aspects of health unless asked about the general context of their lives. The family-centredness of immigrant women's well-being is a mediating factor in all aspects of their health; it is the health of the family unit that is the final point of adjudication for women. Spirituality and religious practices were identified as important resources for health. In addition, the process of immigration needs to be recognized as a determinant of health in and of itself. An understanding of these conceptualizations and health beliefs is an important component of the knowledge to be brought to formulating health promotion strategies and health services delivery that are relevant to and appropriate for this population of mid-life women.

Nesting and shredding behavior as an indicator of hippocampal ischemic damage.

Mongolian gerbils were subjected to bilateral carotid artery occlusion, exposed to nesting material and examined daily. Five minutes of ischemia significantly reduced nesting behavior for 3 days; while 10 min attenuated nesting 6 days. Semi-novel re-exposure to nesting material also resulted in deficits. These disruptions in nesting behavior directly correlate to the amount of ischemic morphological damage and thus serve as a behavioral indicator of tissue damage.

Some microbiological assays of ground beef blended with hydrogenated soybean oil.

Ground beef patties were formulated from beef lean, beef fat and hydrogenated soybean oil. Using the Pearson Square Method, the patties were formed to contain three total fat levels (16,20 and 24%). At each level, vegetable fat was substituted for 0,25 or 50% of total fat to end up with nine different blends. Aerobic psychrotrophs and mesophiles of the blends were investigated at 0-, 3- and 6-day intervals. A split-split plot design with two replications was used to differentiate significant and non-significant attributes of the main effect and the corresponding interactions. Results obtained show that total fat level, percentage vegetable fat or replication did not have a significant effect on bacterial numbers of ground beef extended with hydrogenated soybean oil of 70 iodine value. However, the days of storage significantly (P <0·001) affected both the Standard Plate Count (SPC) and Psychotrophic Plate Count (PPC). The log number of bacteria in both SPC and PPC continued to increase with length of storage. In all the cases studied PPC was found to be higher than SPC, which indicates that the predominant microflora in raw beef products is psychrotrophic in nature.

Effects of long-term exposure to low levels of ozone: a review.

Available literature regarding long-term effects of ozone on animals and humans is reviewed. Emphasis is placed on reports that have appeared since 1976, but some earlier reports are cited for completeness and perspective. This review shows that ozone concentration is more important than duration of exposure in determining the effects of an ozone exposure (dose). This conclusion calls into question the validity of the Time-Weighted Average (TWA) as an index of severity of ozone exposure. The literature review further reveals a wide variation in susceptibility of different animal species to ozone, making it difficult to apply results of animal experiments to humans. It further appears that a dose of ozone that is acutely innocuous is also innocuous over the long term. The effects of a symptom-producing dose of ozone are initially cumulative for the first two or three exposures; then an adaptive response may ensue that involves a plateau of response or even reversal. These effects are shown by both animals and humans. The mechanisms are unknown. Ozone probably causes damage by the free radical formation. Free radical scavengers, such as vitamin E and C, may provide protection against ozone damage.

Growth of Bacteria in Soy-Extended Ground Beef Stored at Three Temperatures.

The objective of this study was to determine the influence of five separate levels of textured soy protein (TSP) on growth of psychrotrophs, mesophiles, coliforms, Staphylococcus aureus , and fecal streptococci in soy-extended ground beef stored at -16°, 0° and 6°C. Highly significant increases in psychrotroph and mesophile counts accompanied increased levels of soy at 0° and 6°C, but not at -16°C. Soy-extended beef samples containing 20 and 40% TSP spoiled one day faster at 6°C and four days sooner at 0°C than non-extended ground beef. No significant differences in coliform, fecal streptococci or S. aureus counts could be attributed to increasing levels of TSP in extended ground beef at -16°, 0° or 6°C. Protein content did not vary significantly with TSP concentration; however, fat decreased as soy level increased. Moisture and carbohydrate-ash content increased significantly as soy level increased, as did pH which reached a maximum of 6.5.

Microbial profiles of country-cured hams aged in stockinettes, barrier bags, and paraffin wax.

No significant differences were found in surface microflora of county-cured hams covered with stockinettes, barrier bags, or a coating of paraffin wax during aging, except for a reduction in mold growth on waxed hams. The incidence of Clostridium spp. was lost in all treatments. Micrococcus spp. and Streptococcus spp. were the most common contaminants, but caused no apparent spoilage problem in any treatment.

Pulmonary and symptom threshold effects of ozone in airline passenger and cockpit crew surrogates.

Previous studies showed that the ozone concentration for pulmonary and symptom threshold effects in flight attendant surrogates lies between 0.20 and 0.30 ppmv for a 3-h exposure with intermittent treadmill exercise at 1829 m (MSL) stimulated cabin altitude. In the present study of sedentary occupants of the in-flight airline cabin, the same protocol was used except for omitting all treadmill exercise. Symptoms were assessed with a standardized questionnaire. Pulmonary function was assessed using standardized quantitative spirometry. Male smoker and nonsmoker airline passanger and cockpit crew surrogates 40-59 years of age were used. Small but statistically significant displacements occurred in symptoms and in some spirometry parameters. In general, the younger subjects appeared more sensitive to ozone than the older subjects. No significant differences appeared between smokers' and nonsmokers' responses to ozone exposure. It is concluded that the ozone threshold of these sedentary surrogates under these experimental conditions is right at 0.30 ppmv.

Effects of ozone on symptoms and cardiopulmonary function in a flight attendant surrogate population.

Two studies were conducted to ascertain the lowest ozone concentration threshold for statistically significant adverse effects on cardiopulmonary function and symptoms in male and female surrogates of the flight attendant population. Both studies simulated in-flight environmental conditions at 1,829 m mean sea level (MSL) chamber altitude. The ozone exposures were 0.2 parts per million by volume (ppmv) for 4 h in the first study and 0.3 ppmv for 3 h in the second study. Each subject was similarly exposed to air only (no ozone) on another occasion. Treadmill exercise, equivalent to workloads of on-duty flight attendants, was performed at altitude. Cardiorespiratory measurements were made during ozone exposure, whereas spirometry and symptom assessments were made immediately before and after exposure. The ozone threshold for reversible adverse effects on symptoms and spirometry function was reached by a 3-h exposure to 0.3 ppmv. The data suggest a greater symptomatic sensitivity to ozone in females.

Stress in air traffic personnel: low-density towers and flight service stations.

Stress and anxiety levels were measured in 10 air traffic control specialists (ATCS) at two low traffic-density towers in Fayetteville (FYV), Ar, and Roswell (ROW), NM, and in 24 flight service (FS) specialists at those airports and at Okalhoma City (OKC), Ok. Physiological measurements consisted of heart rate and urine biochemical analysis for 17-ketogenic steroids, epinephrine, and norepinephrine. On-duty arousal in ATCSs and FS specialists was evident both physiologically and psychologically; such arousal was within psychologically normal limits and was generally low physiologically compared to other air traffic control (ATC) facilities studied in the past. Physiological stress levels at these low-density towers and flight service stations were also low compared to other ATC facilities studied previously. Therefore, it is inappropriate to describe all air traffic control work, as is commonly done in the popular press, as unusually stressful. Such accounts in the popular press tend to deal with the exceptional, rather than with the typical, controller or facility.

Hemoglobins in single chick erythrocytes as determined by a differential elution procedure.

The switch from embryonic to adult hemoglobin (Hb) has been studied in vivo by a correlated cytological and electrophoretic analysis of circulating red blood cells from early, purely embryonic-Hb stages to purely adult-Hb stages including the adult chicken. It has been discovered, by using an acid buffer treatment that selectively elutes adult but not embryonic Hb from intact red blood cells, that embryonic and adult Hbs occur together in single cells, and that the switch occurs simultaneously in all cells. These results together with knowledge of the chick erythroid cell dynamics and ontogenetic titers indicate that the initiation of adult Hb synthesis occurs in the circulation in cells previously committed only to embryonic Hb synthesis.