Phylogeographic Insights Into Zika Virus In Puerto Rico

During the larger epidemic in the Americas, Puerto Rico experienced an epidemic of Zika virus (ZIKV) between November 2015 and December 2016. During this period, 39,717 residents tested positive, or 1.1% of the population. Our team sequenced 84 ZIKV genomes directly from archived ZIKV-positive clinical samples from throughout the epidemic period, and from distinct regions of the island, in order to reconstruct the introduction(s) to and geographic spread of ZIKV in Puerto Rico. We found that ZIKV was circulating in the Greater Antilles by April (95% CI: February-June) of 2015, and was introduced to Puerto Rico by August (95% CI: July-November) of 2015. While there were multiple introductions, just two showed evidence of sustained transmission and just one lineage included 77% of the samples in our data set. Coastal areas of the island, particularly the northeastern coast, saw early introductions and were sources of introductions to other areas of the island. Spread was highly correlated with ZIKV incidence at the origin, and not with volume of travel between locations. This epidemic is part of a growing trend of increasing arbovirus emergence and burden in the Americas and the Caribbean in particular, underscoring the importance of understanding dynamics specific to Puerto Rico as well as general driving factors behind epidemic and endemic arbovirus spread

Flipping the Winner of a Poset Game

Partially-ordered set games, also called poset games, are a class of two-player combinatorial games. The playing field consists of a set of elements, some of which are greater than other elements. Two players take turns removing an element and all elements greater than it, and whoever takes the last element wins. Examples of poset games include Nim and Chomp. We investigate the complexity of computing which player of a poset game has a winning strategy. We give an inductive procedure that modifies poset games to change the nim- value which informally captures the winning strategies in the game. For a generic poset game G, we describe an efficient method for constructing a game not G such that the first player has a winning strategy if and only if the second player has a winning strategy on G. This solves the long-standing problem of whether this construction can be done efficiently. This construction also allows us to reduce the class of Boolean formulas to poset games, establishing a lower bound on the complexity of poset games

Mapping the Galaxy Color-Redshift Relation: Optimal Photometric Redshift Calibration Strategies for Cosmology Surveys

Calibrating the photometric redshifts of >10^9 galaxies for upcoming weak lensing cosmology experiments is a major challenge for the astrophysics community. The path to obtaining the required spectroscopic redshifts for training and calibration is daunting, given the anticipated depths of the surveys and the difficulty in obtaining secure redshifts for some faint galaxy populations. Here we present an analysis of the problem based on the self-organizing map, a method of mapping the distribution of data in a high-dimensional space and projecting it onto a lower-dimensional representation. We apply this method to existing photometric data from the COSMOS survey selected to approximate the anticipated Euclid weak lensing sample, enabling us to robustly map the empirical distribution of galaxies in the multidimensional color space defined by the expected Euclid filters. Mapping this multicolor distribution lets us determine where - in galaxy color space - redshifts from current spectroscopic surveys exist and where they are systematically missing. Crucially, the method lets us determine whether a spectroscopic training sample is representative of the full photometric space occupied by the galaxies in a survey. We explore optimal sampling techniques and estimate the additional spectroscopy needed to map out the color-redshift relation, finding that sampling the galaxy distribution in color space in a systematic way can efficiently meet the calibration requirements. While the analysis presented here focuses on the Euclid survey, similar analysis can be applied to other surveys facing the same calibration challenge, such as DES, LSST, and WFIRST.Comment: ApJ accepted, 17 pages, 10 figure

U.S. Nuclear Regulatory Commission Extremely Low Probability of Rupture pilot study : xLPR framework model user's guide.

Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owne

Preliminary results of the APAC spills working group

The Spills Working Group is one of 6 working groups under the DOE-DP Accident Phenomenology and Consequence (APAC) methodology evaluation program. Objectives are to assess methodologies available in this area, evaluate their adequacy for accident analysis at DOE facilities, identify development needs, and define standard practices to be followed in the analyses supporting facility safety basis documentation. The group focused on methodologies for estimating 4 types of spill source terms: liquid chemical spills and evaporation, pressurized liquid/gas releases, solid spills and resuspension/sublimation, and resuspension of particulate matter from liquid spills. Computer models were identified with capabilities for quantifying release rates or released amounts from spills, and a set of sample test problems was established for evaluating a specific model for some common or probable accident release scenarios. The group agreed on a set of recommended computer codes which are classified according to spill type and hazard category. Code results for a given problem varied by up to an order of magnitude; this is attributed to differences in how the physics and thermodynamics of the problems were treated by the models

Biological necrectomy and vacuum-therapy in complex treatment of decompensated chronic venous insufficiency of the lower extremities

Objective. To improve the results of treatment in patients, suffering decompensated forms of chronic venous insufficiency (CHVI) of the lower extremities, using introduction of biological necrectomy and vacuum-therapy in combination with complex of optimal surgical interventions, depending on state of venous hemodynamics of the lower extremities. Materials and methods. In 2015-2018 yrs in Surgical Clinic of the Zakarpattya Regional Clinical Hospital named after Andriy Novak 147 patients, ageing 40 yrs old and older, suffering CHVI Category C6 in accordance to the CEAP Classification, were treated. All the patients were divided into two groups: the Group I consisted of 76 patients, suffering CHVI in decompensated stage on background of varicose disease, and the Group II - 71 patients, suffering trophic ulcers (TU) on background of postthrombophlebitic syndrome (PTHPHS). Results. There was established, that the TU clearance under the action of maggot-therapy in patients, suffering decompensated course of CHVI, is significantly more effective, than under the impact of vacuum-therapy. Autodermoplasty must be performed in all the patients, having TU with 4 cm in diameter, Good and satisfactory results were observed in 75 (98.7%) patients of Group I and in 63 (88.7%) patients of Group II, while poor results - in 8 (11.3%) patients of Group II. The working capacity of patients, suffering CHVI in decompensated stage of varicose genesis, have enhanced in 16.5 times, while in the patients, suffering TU on background of PTHPHS – in 1.25 times. Conclusion. Combined treatment of CHVI in decompensated stage, occurring on background of varicose disease includes the TU clearance, using vacuum-therapy or biological necrectomy with subsequent elimination of vertical reflux. In the patients, suffering TU on the PTHPHS background the biologic necrectomy with elimination of horizontal reflux is advantageous. The working capacity in patients with CHVI in decompensated stage of varicose genesis have enhanced in 16.5 times, while in the patients with TU on the PTHPHS background - in 1.25 times

Embedded Weapons-Grade Tungsten Alloy Shrapnel Rapidly Induces Metastatic High-Grade Rhabdomyosarcomas in F344 Rats

Continuing concern regarding the potential health and environmental effects of depleted uranium and lead has resulted in many countries adding tungsten alloy (WA)-based munitions to their battlefield arsenals as replacements for these metals. Because the alloys used in many munitions are relatively recent additions to the list of militarily relevant metals, very little is known about the health effects of these metals after internalization as embedded shrapnel. Previous work in this laboratory developed a rodent model system that mimicked shrapnel loads seen in wounded personnel from the 1991 Persian Gulf War. In the present study, we used that system and male F344 rats, implanted intramuscularly with pellets (1 mm × 2 mm cylinders) of weapons-grade WA, to simulate shrapnel wounds. Rats were implanted with 4 (low dose) or 20 pellets (high dose) of WA. Tantalum (20 pellets) and nickel (20 pellets) served as negative and positive controls, respectively. The high-dose WA-implanted rats (n = 46) developed extremely aggressive tumors surrounding the pellets within 4–5 months after implantation. The low-dose WA-implanted rats (n = 46) and nickel-implanted rats (n = 36) also developed tumors surrounding the pellets but at a slower rate. Rats implanted with tantalum (n = 46), an inert control metal, did not develop tumors. Tumor yield was 100% in both the low- and high-dose WA groups. The tumors, characterized as high-grade pleomorphic rhabdomyosarcomas by histopathology and immunohistochemical examination, rapidly metastasized to the lung and necessitated euthanasia of the animal. Significant hematologic changes, indicative of polycythemia, were also observed in the high-dose WA-implanted rats. These changes were apparent as early as 1 month postimplantation in the high-dose WA rats, well before any overt signs of tumor development. These results point out the need for further studies investigating the health effects of tungsten and tungsten-based alloys

Complex microwave processing of high-ash brown coal in relation to the energy and metallurgical industries

Relevance. The need of the Tomsk region for valuable energy resources obtained from local low-grade resources to develop iron ore deposits available in the region and cover energy needs. Aim. To study gaseous and solid products obtained from low-grade brown coal of the Talovsky deposit (Tomsk region) under microwave pyrolysis conditions in relation to the energy and metallurgical industries. Objects. Brown coal of the Talovsky deposit (Tomsk region). Methods. Certified SS methods to determine thermal characteristics and elemental composition of coal organic and mineral parts, the "transmission-reflection" method for measuring imaginary (ε'') and real (ε') components of the complex dielectric permittivity, physical experiment, gas analysis, Brunauer–Emmett–Teller method for measuring texture characteristics. Results. Brown coal of the Talovsky deposit has high values of moisture and ash contents for operating conditions, which leads to a low calorific value. Such characteristics make it possible to classify coal as a low-grade fuel, which indicates the inexpediency of its use as a raw material for the energy and metallurgical industries. Thermal processing by means of microwave pyrolysis makes it possible to obtain a high-calorie (heat of combustion over 21 MJ/m3) and environmentally friendly (hydrogen content over 29%) gaseous fuel from the low-grade brown coal of the Talovsky deposit. The resulting solid carbonaceous residue has an ash content of over 48%, which required its chemical treatment in a solution of HF and HCl. As a result of the solid carbonaceous residue treatment, its ash content decreased by more than 38%, the sulfur content – by more than 1.5 times. According to its characteristics, the resulting product corresponds to the currently available carbonaceous products – semi-coke, coke and carbon reducing agent for ferroalloy production

Viral dynamics of acute SARS-CoV-2 infection and applications to diagnostic and public health strategies.

SARS-CoV-2 infections are characterized by viral proliferation and clearance phases and can be followed by low-level persistent viral RNA shedding. The dynamics of viral RNA concentration, particularly in the early stages of infection, can inform clinical measures and interventions such as test-based screening. We used prospective longitudinal quantitative reverse transcription PCR testing to measure the viral RNA trajectories for 68 individuals during the resumption of the 2019-2020 National Basketball Association season. For 46 individuals with acute infections, we inferred the peak viral concentration and the duration of the viral proliferation and clearance phases. According to our mathematical model, we found that viral RNA concentrations peaked an average of 3.3 days (95% credible interval [CI] 2.5, 4.2) after first possible detectability at a cycle threshold value of 22.3 (95% CI 20.5, 23.9). The viral clearance phase lasted longer for symptomatic individuals (10.9 days [95% CI 7.9, 14.4]) than for asymptomatic individuals (7.8 days [95% CI 6.1, 9.7]). A second test within 2 days after an initial positive PCR test substantially improves certainty about a patient's infection stage. The effective sensitivity of a test intended to identify infectious individuals declines substantially with test turnaround time. These findings indicate that SARS-CoV-2 viral concentrations peak rapidly regardless of symptoms. Sequential tests can help reveal a patient's progress through infection stages. Frequent, rapid-turnaround testing is needed to effectively screen individuals before they become infectious