Mathematical modelling of zika virus in Brazil

In this paper we study some deterministic mathematical models that seek to explain the expansion of zika virus, as a viral epidemic, using published data for Brazil. SIR type models are proposed and validated using the epidemic data found, considering several aspects in the spread of the disease. Finally, we confirmed that the crucial epidemic parameter such as $R_0$ is consistent with those previously reported in the literature for other areas. We also explored variations of the parameters within Brazil for different federal entities. We concluded that a parsimonious model that includes both human and vector populations best describe the epidemic parameters

Comparison of Frequentist and Bayesian Meta-Analysis Models for Assessing the Efficacy of Decision Support Systems in Reducing Fungal Disease Incidence

Diseases of fruit and foliage caused by fungi and oomycetes are generally controlled by the application of fungicides. The use of decision support systems (DSSs) may assist to optimize fungicide programs to enhance application on the basis of risk associated with disease outbreak. Case-by-case evaluations demonstrated the performance of DSSs for disease control, but an overall assessment of the efficacy of DSSs is lacking. A literature review was conducted to synthesize the results of 67 experiments assessing DSSs. Disease incidence data were obtained from published peer-reviewed field trials comparing untreated controls, calendar-based and DSS-based fungicide programs. Two meta-analysis generic models, a “fixed-effects” vs. a “random-effects” model within the framework of generalized linear models were evaluated to assess the efficacy of DSSs in reducing incidence. All models were fit using both frequentist and Bayesian estimation procedures and the results compared. Model including random effects showed better performance in terms of AIC or DIC and goodness of fit. In general, the frequentist and Bayesian approaches produced similar results. Odds ratio and incidence ratio values showed that calendar-based and DSS-based fungicide programs considerably reduced disease incidence compared to the untreated control. Moreover, calendar-based and DSS-based programs provided similar reductions in disease incidence, further supporting the efficacy of DSSs

Evidence for a meteoritic origin of the September 15, 2007, Carancas crater

On September 15th, 2007, around 11:45 local time in Peru, near the Bolivian border, the atmospheric entry of a meteoroid produced bright lights in the sky and intense detonations. Soon after, a crater was discovered south of Lake Titicaca. These events have been detected by the Bolivian seismic network and two infrasound arrays operating for the Comprehensive Nuclear-Test-Ban Treaty Organization, situated at about 80 and 1620 km from the crater. The localization and origin time computed with the seismic records are consistent with the reported impact. The entry elevation and azimuthal angles of the trajectory are estimated from the observed signal time sequences and backazimuths. From the crater diameter and the airwave amplitudes, the kinetic energy, mass and explosive energy are calculated. Using the estimated velocity of the meteoroid and similarity criteria between orbital elements, an association with possible parent asteroids is attempted. The favorable setting of this event provides a unique opportunity to evaluate physical and kinematic parameters of the object that generated the first actual terrestrial meteorite impact seismically recorded

Confirmation of symmetrical distributions of clinical attachment loss and tooth loss in a homogeneous Mexican adult male population

Background/purpose To ascertain whether or not clinical attachment loss and tooth loss are present with similar severity and prevalence across the two sides of the mouth in a homogeneous sample of urban male adults. Materials and methods A cross-sectional study was carried out on 161 policemen (a largely homogeneous group in terms of ethnic background, socioeconomic status, sex, occupation, and medical/dental insurance) in Campeche, Mexico. Periodontal examinations were undertaken using the Florida Probe System in a dental chair by one trained and standardized examiner (kappa ≥ 0.60) to determine clinical attachment loss and tooth loss. We examined six sites in all teeth present in the mouth (a maximum of 168 sites, no third molars). Because of correlated data between observations, McNemar (for tooth loss) and Wilcoxon (for attachment loss) signed-rank tests were used to compare right and left sites within the same patient. Results The mean age was 38.4 ± 11.0 years. The mean number of teeth present was 24.4 ± 4.6; the mean number of periodontal sites/person was 146.7 ± 27.8. All P values were ≥ 0.05 (except for attachment loss in the upper first premolars), suggesting that there were no statistically significant differences between the right and left sides for the frequency of presentation of these two conditions. Conclusion Tooth loss and attachment loss measurements largely resemble each other on both sides of the mouth

Should Student Employment Be Subsidized? Conditional Counterfactuals and the Outcomes of Work-Study Participation: Appendices A and B

Appendices A and B to "Should Student Employment Be Subsidized? Conditional Counterfactuals and the Outcomes of Work-Study Participation" (DOI: 10.7916/D8JH3JTP)

A Strategy for Estimating the Effects of Whole-College Guided Pathways Reforms in Community Colleges

Approximately 450 community colleges nationally are part of formal statewide or national initiatives to implement guided pathways reforms to improve student success, and many other colleges are implementing guided pathways practices on their own. Because guided pathways is a whole-college reform—and because it takes several years to fully implement—it is challenging to evaluate. This paper presents a methodology for assessing the scale of adoption and estimating the causal effects of guided pathways within states and across colleges that have adopted the approach. To measure the scale of adoption of guided pathways practices, we will conduct institutional surveys and phone interviews with college leaders and examine the websites of every community college in Ohio, Tennessee, and Washington (70 institutions total). We plan to use these data to estimate each college’s scale of adoption using a rubric with indicators for scale and timing. Drawing on strategies used in K-12 whole-school reform evaluations, we propose to examine pre-reform adoption trends and apply a single interrupted time series design to project what students’ early outcomes would have been in the absence of guided pathways. We then propose to use a comparative interrupted time series design (which closely resembles a difference-in-differences approach) to exploit variation in the intensity of guided pathways practices and the timing of their adoption across colleges by comparing early student outcomes in colleges that have adopted guided pathways practices at scale and those that have not or those with a low scale of adoption

An international assessment of surgeon practices in abdominal wound closure and surgical site infection prevention by the European Society for Coloproctology

Abdominal wound; Incisional hernia; Surgical site infectionFerida abdominal; Hèrnia incisional; Infecció del lloc quirúrgicHerida abdominal; Hernia incisional; Infección del sitio quirúrgicoAim The burden of abdominal wound failure can be profound. Recent clinical guidelines have highlighted the heterogeneity of laparotomy closure techniques. The aim of this study was to investigate current midline closure techniques and practices for prevention of surgical site infection (SSI). Method An online survey was distributed in 2021 among the membership of the European Society of Coloproctology and its partner societies. Surgeons were asked to provide information on how they would close the abdominal wall in three specific clinical scenarios and on SSI prevention practices. Results A total of 561 consultants and trainee surgeons participated in the survey, mainly from Europe (n = 375, 66.8%). Of these, 60.6% identified themselves as colorectal surgeons and 39.4% as general surgeons. The majority used polydioxanone for fascial closure, with small bite techniques predominating in clean-contaminated cases (74.5%, n = 418). No significant differences were found between consultants and trainee surgeons. For SSI prevention, more surgeons preferred the use of mechanical bowel preparation (MBP) alone over MBP and oral antibiotics combined. Most surgeons preferred 2% alcoholic chlorhexidine (68.4%) or aqueous povidone-iodine (61.1%) for skin preparation. The majority did not use triclosan-coated sutures (73.3%) or preoperative warming of the wound site (78.5%), irrespective of level of training or European/non-European practice. Conclusion Abdominal wound closure technique and SSI prevention strategies vary widely between surgeons. There is little evidence of a risk-stratified approach to wound closure materials or techniques, with most surgeons using the same strategy for all patient scenarios. Harmonization of practice and the limitation of outlying techniques might result in better outcomes for patients and provide a stable platform for the introduction and evaluation of further potential improvements

A search for anisotropy in the arrival directions of ultra high energy cosmic rays recorded at the Pierre Auger Observatory

Observations of cosmic rays arrival directions made with the Pierre Auger Observatory have previously provided evidence of anisotropy at the 99% CL using the correlation of ultra high energy cosmic rays (UHECRs) with objects drawn from the Veron-Cetty Veron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2pt-L, 2pt+ and 3pt methods, each giving a different measure of self-clustering in arrival directions, were tested on mock cosmic ray data sets to study the impacts of sample size and magnetic smearing on their results, accounting for both angular and energy resolutions. If the sources of UHECRs follow the same large scale structure as ordinary galaxies in the local Universe and if UHECRs are deflected no more than a few degrees, a study of mock maps suggests that these three method can efficiently respond to the resulting anisotropy with a P-value = 1.0% or smaller with data sets as few as 100 events. using data taken from January 1, 2004 to July 31, 2010 we examined the 20, 30, ... , 110 highest energy events with a corresponding minimum energy threshold of about 49.3 EeV. The minimum P-values found were 13.5% using the 2pt-L method, 1.0% using the 2pt+ method and 1.1% using the 3pt method for the highest 100 energy events. In view of the multiple (correlated) scans performed on the data set, these catalog-independent methods do not yield strong evidence of anisotropy in the highest energy cosmic rays

The rapid atmospheric monitoring system of the Pierre Auger Observatory

The Pierre Auger Observatory is a facility built to detect air showers produced by cosmic rays above 10^17 eV. During clear nights with a low illuminated moon fraction, the UV fluorescence light produced by air showers is recorded by optical telescopes at the Observatory. To correct the observations for variations in atmospheric conditions, atmospheric monitoring is performed at regular intervals ranging from several minutes (for cloud identification) to several hours (for aerosol conditions) to several days (for vertical profiles of temperature, pressure, and humidity). In 2009, the monitoring program was upgraded to allow for additional targeted measurements of atmospheric conditions shortly after the detection of air showers of special interest, e. g., showers produced by very high-energy cosmic rays or showers with atypical longitudinal profiles. The former events are of particular importance for the determination of the energy scale of the Observatory, and the latter are characteristic of unusual air shower physics or exotic primary particle types. The purpose of targeted (or "rapid") monitoring is to improve the resolution of the atmospheric measurements for such events. In this paper, we report on the implementation of the rapid monitoring program and its current status. The rapid monitoring data have been analyzed and applied to the reconstruction of air showers of high interest, and indicate that the air fluorescence measurements affected by clouds and aerosols are effectively corrected using measurements from the regular atmospheric monitoring program. We find that the rapid monitoring program has potential for supporting dedicated physics analyses beyond the standard event reconstruction