Bifurcations in the wake of a thick circular disk

Using DNS, we investigate the dynamics in the wake of a circular disk of aspect ratio χ = d/w = 3(where d is the diameter and w the thickness) embedded in a uniform flow of magnitude U0 perpendicular to its symmetry axis. As the Reynolds number Re = U0d/ν is increased, the flow is shown to experience an original series of bifurcations leading to chaos. The range Re ∈ [150, 218] is analysed in detail. In this range, five different non-axisymmetric regimes are successively encountered, including states similar to those previously identified in the flow past a sphere or an infinitely thin disk, as well as a new regime characterised by the presence of two distinct frequencies. A theoretical model based on the theory of mode interaction with symmetries, previously introduced to explain the bifurcations in the flow past a sphere or an infinitely thin disk (Fabre et al. in Phys Fluids 20:051702, 2008), is shown to explain correctly all these results. Higher values of the Reynolds number, up to 270, are also considered. Results indicate that the flow encounters at least four additional bifurcations before reaching a chaotic state

CHARACTERISTICS OF PATIENTS WITH LOW HEPATITIS C TREATMENT RATES IN URBAN MEDICAL CENTER CLINICS

The objective of this study was to determine whether there were different characteristics between HCV patients who were treated and those not treated after their first visit to a Gastroenterology (GI) or Infectious Disease (ID) clinic. This information might identify potential targets for remedial actions that could be performed to increase the number of treated patients. Data was collected from 2019 HCV patient EMR charts including patient demographics, treatment history, and laboratory studies. We defined success as receiving treatment by July 2020 (6-18 months after the first visit). We found that of 587 patients with HCV who were seen at least once in the Wayne Health system, 441 patients (441/587=75%) were not treated and only 189 (189/441= 43%) were treated by July 2020. Treated and not treated patients were similar with respect to race, gender, age, and median income defined by zip code. They were also not different with respect to the clinic seen (ID vs GI), the type of insurance, or the degree of fibrosis. However, patients with an average of 4 visits were more likely to be treated than those having 2 visits. Having 1 visit was the most dramatic factor in the lack of treatment (42% vs 8% p\u3c0.0001). PCR available at first visit was an important factor with respect to treatment (treated 38% vs not treated 25% p\u3c0.02)

Approche décisionnelle géospatiale et multicritère dans l’identification des zones potentielles de recharge des eaux souterraines : cas du bassin versant du Mayo Bocki au Nord Cameroun

La présente étude a été effectuée pour déterminer les zones potentielles de recharge des eaux souterraines. Pour ce faire, la démarche  méthodologique était basée sur l’analyse multicritère associée aux techniques géospatiales. Les données utilisées étaient entre autres les images  satellitaires, les fonds cartographiques, les données pluviométriques et les niveaux statiques. Ces données ont permis d’exprimer sous forme de  carte thématique les facteurs régissant la recharge (pente, drainage, lithologie, fracturation, sol, pluviométrie et occupation du sol). L’analyse de  sensibilité par suppression d’un paramètre a permis d’établir l’ordre d’influence suivant : Lit > Sol > AACH > Df > Pl > Pe > Dd > OS. Le croisement de  tous ces paramètres après pondération a conduit à l’élaboration de la carte qui montre que les zones à ort potentiel occupent 3 % de la zone d’étude  pendant que les zones de faible à faible potentialité sont de l’ordre de 58 % dans le bassin. Les zones à potentialité moyenne quant à elles  représentent 39%. Ce support cartographique constitue indéniablement un outil d’aide à la décision pour les gestionnaires de l’eau.   This study was carried out to determine potential groundwater recharge areas. To do this, the methodological approach was based on multi-criteria  analysis associated with geospatial techniques. The data used were, among others, satellite images, base maps, rainfall data and static levels. These  data made it possible to express in the form of a thematic map the factors governing the recharge (slope, drainage, lithology, fracturing, soil,  rainfall and land use). The sensitivity analysis by deletion of a parameter made it possible to establish the following order of influence: Lit > Sol  > AACH > Df > Pl > Pe > Dd > OS. The crossing of all these parameters after weighting led to the development of the map of potential recharge zones  which revealed that the zones with high potential occupy 3% of the study zone while the zones with low to low potentiality are around 58% in  the basin. Areas with average potential represent 39%. This cartographic support is undeniably a decision-making tool for water managers

First Results of the Phase II SIMPLE Dark Matter Search

We report results of a 14.1 kgd measurement with 15 superheated droplet detectors of total active mass 0.208 kg, comprising the first stage of a 30 kgd Phase II experiment. In combination with the results of the neutron-spin sensitive XENON10 experiment, these results yield a limit of |a_p| < 0.32 for M_W = 50 GeV/c2 on the spin-dependent sector of weakly interacting massive particle-nucleus interactions with a 50% reduction in the previously allowed region of the phase space formerly defined by XENON, KIMS and PICASSO. In the spin-independent sector, a limit of 2.3x10-5 pb at M_W = 45 GeV/c2 is obtained.Comment: 4 pages, 4 figures; PRL-accepted version with corrected SI contour (Fig. 4

Scaling of Wave-Packet Dynamics in an Intense Midinfrared Field

A theoretical investigation is presented that examines the wavelength scaling from near-visible (0.8 µm) to midinfrared (2 µm) of the photoelectron distribution and high harmonics generated by a "single" atom in an intense electromagnetic field. The calculations use a numerical solution of the time-dependent Schrödinger equation (TDSE) in argon and the strong-field approximation in helium. The scaling of electron energies (λ^2), harmonic cutoff (λ^2), and attochirp (λ^-1) agree with classical mechanics, but it is found that, surprisingly, the harmonic yield follows a λ^-(5-6) scaling at constant intensity. In addition, the TDSE results reveal an unexpected contribution from higher-order returns of the rescattering electron wave packet

The effect of cocaine on gastric mucosal PGE2, LTC4 and ulcerations

The association between cocaine use and acute gastroduodenal perforation is known. The effect of cocaine and stress on gastric mucosal ulceration and the levels of prostaglandin E2 (PGE2) and leukotriene C4 (LTC4) was studied in 40 Sprague–Dawley rats. Controls received intraperitoneal (i.p.) saline, ten received i.p. cocaine (35 mg/kg), ten were stressed by the cold restraint method, and ten had i.p. cocaine and stress. Cocaine alone did not induce ulceration, but decreased PGE2 levels. Stress alone caused ulceration, but was not associated with a change in either PGE2 or LTC4 levels. When combined with stress, however, cocaine caused a three-fold increase in ulceration and a significant increase in PGE2 and LTC4 levels. Stress may predispose the cocaine addict to loss of gastroduodenal mucosal integrity, which is related to an imbalance of PGE2 and LTC4 synthesis

FAILURE TO TREAT HCV IN PATIENTS SEEN IN A PREDOMINATELY AFRICAN AMERICAN SOCIOECONOMICALLY CHALLENGED POPULATION

The research objective of this proposal is to investigate the impediment with respect to moving a patient from initial antibody/PCR positive to successful completion of treatment. Secondary objectives include determining the most effective way for patients to progress from initial antibody/PCR positive to treatment and identifying the roadblocks for HCV antibody/PCR positive patients to be treated effectively. Data was collected from 2019 HCV patient EMR charts, including demographics, laboratory studies, and treatment history. Concerning treatment, we evaluated linkage to the care; we defined success as treatment within six months of the initial visit. Thus, data on treatment initiation was collected through the first six months of 2020

The SIMPLE Phase II Dark Matter Search

Phase II of SIMPLE (Superheated Instrument for Massive ParticLe Experiments) searched for astroparticle dark matter using superheated liquid C$_{2}$ClF$_{5}$ droplet detectors. Each droplet generally requires an energy deposition with linear energy transfer (LET) $\gtrsim$ 150 keV/$\mu$m for a liquid-to-gas phase transition, providing an intrinsic rejection against minimum ionizing particles of order 10$^{-10}$, and reducing the backgrounds to primarily $\alpha$ and neutron-induced recoil events. The droplet phase transition generates a millimetric-sized gas bubble which is recorded by acoustic means. We describe the SIMPLE detectors, their acoustic instrumentation, and the characterizations, signal analysis and data selection which yield a particle-induced, "true nucleation" event detection efficiency of better than 97% at a 95% C.L. The recoil-$\alpha$ event discrimination, determined using detectors first irradiated with neutrons and then doped with alpha emitters, provides a recoil identification of better than 99%; it differs from those of COUPP and PICASSO primarily as a result of their different liquids with lower critical LETs. The science measurements, comprising two shielded arrays of fifteen detectors each and a total exposure of 27.77 kgd, are detailed. Removal of the 1.94 kgd Stage 1 installation period data, which had previously been mistakenly included in the data, reduces the science exposure from 20.18 to 18.24 kgd and provides new contour minima of $\sigma_{p}$ = 4.3 $\times$ 10$^{-3}$ pb at 35 GeV/c$^{2}$ in the spin-dependent sector of WIMP-proton interactions and $\sigma_{N}$ = 3.6 $\times$ 10$^{-6}$ pb at 35 GeV/c$^{2}$ in the spin-independent sector. These results are examined with respect to the fluorine spin and halo parameters used in the previous data analysis.Comment: 20 pages, 19 figures; accepted Physical Review