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We explore the ability of anisotropic permeable substrates to reduce turbulent skin friction, studying the influence that these substrates have on the overlying turbulence. For this, we perform direct numerical simulations of channel flows bounded by permeable substrates. The results confirm theoretical predictions, and the resulting drag curves are similar to those of riblets. For small permeabilities, the drag reduction is proportional to the difference between the streamwise and spanwise permeabilities. This linear regime breaks down for a critical value of the wall-normal permeability, beyond which the performance begins to degrade. We observe that the degradation is associated with the appearance of spanwise-coherent structures, attributed to a Kelvin–Helmholtz-like instability of the mean flow. This feature is common to a variety of obstructed flows, and linear stability analysis can be used to predict it. For large permeabilities, these structures become prevalent in the flow, outweighing the drag-reducing effect of slip and eventually leading to an increase of drag. For the substrate configurations considered, the largest drag reduction observed is
20–25 % at a friction Reynolds number
The main objective of this study was to determine the prevalence of work-related musculoskeletal symptoms in otolaryngology and head and neck surgery specialists and trainees in Spain, and to measure the effect that physical exercise could have on muscular discomfort.
A cross-sectional survey was administered between September and December 2017 to practising otolaryngologists.
Four hundred and three ENT surgeons responded, with a median age of 44.9 years, and 89.8 per cent reported discomfort or physical symptoms that they attributed to surgical practice. More female surgeons reported musculoskeletal symptoms (92.8 per cent vs 87.1 per cent; p = 0.04). When the level of physical activity was compared with the frequency of physical discomfort, no significant difference was found.
This study has shown a high prevalence of musculoskeletal disorders among ENT surgeons in Spain but has failed to demonstrate an important role of physical exercise in the prevention of musculoskeletal disorders.
OBJECTIVES/SPECIFIC AIMS: To introduce CCTS to the clinical and translational research community. METHODS/STUDY POPULATION: Established in the summer of 2017, the Center for Clinical and Translational Science (CCTS) fosters cooperative clinical and translational sciences between the University of Mississippi School of Pharmacy (UMSOP) and the University of Mississippi Medical Center (UMMC). CCTS facilitates the translation of basic research discoveries into clinically validated therapies to improve the health of populations in Mississippi and beyond. Priority areas of investigation in CCTS include Cardiometabolic disorders, Cancer, Neuroscience, Infectious diseases, Precision Medicine, and Community-Based Research. To accomplish CCTS mission three overarching goals have been defined: I) Develop progressive and sustainable capacity for clinical and translational research in Mississippi; II) Promote interprofessional engagement in clinical and translational science; and III) Foster research collaboration among stakeholders in and outside of Mississippi. RESULTS/ANTICIPATED RESULTS: To carry its CCTS’s mission three research units have been established: 1) The Pre-clinical Research Unit: Develops processes to move basic science discoveries towards translation into research in humans. This unit provides guidance in the development of Investigational New Drug (IND) applications; and identifies and pursues opportunities to develop progressive capacities for in vitro, ex vivo, in vivo, and in silico approaches for evaluating new pharmaceutical and therapeutic agents. 2) The Clinical Research Unit: Transitions projects that have received IND approval into the first phase of clinical trials. It also transitions clinical trials from Phase I to Phase II and to Phase III; develops standard operating procedures (SOPs), personnel training plans, and policies to guide clinical research; works with industry sponsors and governmental funding agencies; and assures compliance with regulatory requirements. 3) Community/population Research Unit: Develops, coordinates, and facilitates research activities and translation between clinical and community/population research stages. To do so, this unit works closely with community partners and Population Health programs on the Oxford and Jackson campuses. DISCUSSION/SIGNIFICANCE OF IMPACT: Since its inception, the CCTS has surpassed 1.5 million dollars in competitive funding. This early success positions the CCTS well to promote research collaboration between UMSOP and UMMC and to progress in becoming a national leader in clinical and translational investigation.
The objective of this study was to investigate the impact of the most commonly cited factors that may have influenced infants’ gut microbiota profiles at one year of age: mode of delivery, breastfeeding duration and antibiotic exposure. Barcoded V3/V4 amplicons of bacterial 16S-rRNA gene were prepared from the stool samples of 52 healthy 1-year-old Australian children and sequenced using the Illumina MiSeq platform. Following the quality checks, the data were processed using the Quantitative Insights Into Microbial Ecology pipeline and analysed using the Calypso package for microbiome data analysis. The stool microbiota profiles of children still breastfed were significantly different from that of children weaned earlier (P<0.05), independent of the age of solid food introduction. Among children still breastfed, Veillonella spp. abundance was higher. Children no longer breastfed possessed a more ‘mature’ microbiota, with notable increases of Firmicutes. The microbiota profiles of the children could not be differentiated by delivery mode or antibiotic exposure. Further analysis based on children’s feeding patterns found children who were breastfed alongside solid food had significantly different microbiota profiles compared to that of children who were receiving both breastmilk and formula milk alongside solid food. This study provided evidence that breastfeeding continues to influence gut microbial community even at late infancy when these children are also consuming table foods. At this age, any impacts from mode of delivery or antibiotic exposure did not appear to be discernible imprints on the microbial community profiles of these healthy children.
This study investigates a hypothesized positive relationship between the number and strength of network ties and the performance of wineries in emerging production regions, which may face different challenges than wineries found in well-established regions. Results corroborate expectations that greater ties to competitors and firms in related tourism food and lodging sectors bolster performance. (JEL Classification: Q130)
We determined the molecular epidemiology of Bordetella pertussis isolates to evaluate its potential impact on pertussis reemergence in a population of Mexico. Symptomatic and asymptomatic cases were included. Pertussis infection was confirmed by culture and real-time polymerase chain reaction (PCR). Selected B. pertussis isolates were further analysed; i.e. clonality was analysed by pulsed-field gel electrophoresis (PFGE) and ptxP-ptxA, prn, fim2 and fim3 typing was performed by PCR and sequencing. Out of 11 864 analysed samples, 687 (5.8%) were positive for pertussis, with 244 (36%) confirmed by both culture and PCR whereas 115 (17%) were positive only by culture and 328 (48%) were positive only by PCR. One predominant clone (clone A, n = 62/113; 55%) and three major subtypes (A1, A2 and A3) were identified by PFGE. All 113 selected isolates had the allelic combination ptxP3-ptxA1. The predominant clone A and the three major subtypes (A1, A2 and A3) corresponded to the emerging genotypes ptxP3-ptxA1-prn2-fim2-1-fim3-2 and ptxP3-ptxA1-prn2-fim2-1-fim3-1. In conclusion, the presence of an endemic clone and three predominant subtypes belonging to the genotypes ptxP3-ptxA1-prn2-fim2-1-fim3-2 and ptxP3-ptxA1-prn2-fim2-1-fim3-1 were detected. This finding supports the global spread/expansion reported for these outbreaks associated genotypes.
The aim of this study was to establish the association of maternal, family, and contextual correlates of anthropometric typologies at the household level in Colombia using 2005 Demographic Health Survey (DHS/ENDS) data.
Household-level information from mothers 18–49 years old and their children <5 years old was included. Stunting and overweight were assessed for each child. Mothers were classified according to their body mass index. Four anthropometric typologies at the household level were constructed: normal, underweight, overweight, and dual burden. Four three-level [households (n = 8598) nested within municipalities (n = 226), nested within states (n = 32)] hierarchical polytomous logistic models were developed. Household log-odds of belonging to one of the four anthropometric categories, holding ‘normal’ as the reference group, were obtained.
This study found that anthropometric typologies were associated with maternal and family characteristics of maternal age, parity, maternal education, and wealth index. Higher municipal living conditions index was associated with a lower likelihood of underweight typology and a higher likelihood of overweight typology. Higher population density was associated with a lower likelihood of overweight typology.
Distal and proximal determinants of the various anthropometric typologies at the household level should be taken into account when framing policies and designing interventions to reduce malnutrition in Colombia.
The main objective of our study was to describe the epidemiological and microbiological features of an oligoclonal hospital-wide outbreak caused by OXA-48-producing Enterobacteriaceae (OXA-48-PE). OXA-48 is a carbapenemase belonging to Ambler class D beta-lactamases, identified frequently in the Mediterranean and Southern European countries, and associated with several Enterobacteriaceae species. An outbreak of OXA-48-PE with a complex epidemic pattern was detected in January 2011. Initial control measures included contact precautions and the reinforcement of infection control practices, but despite all efforts made, the epidemiological situation hardly changed and new measures were implemented during 2013. An observational retrospective study was performed to describe the main features of the outbreak and to analyse the cumulative incidence (CI) trends. Eight hundred and 16 patients colonised or infected by OXA-48-PE were identified during the 2-year period (January 2013–December 2014), female 46%, mean age (s.d.), 71.6 (15.2). The samples isolated in the incident cases were rectal swabs (80%), urine samples (10.7%), blood samples (2.8%) and other clinical samples (6.6%). The most frequent OXA-48-PE was Klebsiella pneumoniae. Eleven different clones were identified, but K. pneumoniae sequence types 11 and 405 were predominant: ST11 (64.2%) and ST405 (29.3%). OXA-48-PE CI trend suffered a statistically significant change in August 2013, which continued the following months. Though we could not eradicate the outbreak, we observed a statistically significant drop in CI after an intervention for OXA-48-PE control, based on patient cohort, active surveillance, electronic alerts and reinforcement of infection control measures in a tertiary hospital.
In this study, we sought to evaluate the performance of the Xpert MTB/RIF (Cepheid) assay for the detection of Mycobacterium tuberculosis (MTB) complex DNA on fresh and formalin-fixed, paraffin-embedded (FFPE) tissue specimens from oncology patients in an area with a low prevalence of tuberculosis. We also aimed to retrospectively assess the potential impact of Xpert MTB/RIF on the duration of airborne infection isolation (AII).
A 473-bed, tertiary-care cancer center in New York City.
A total of 203 tissue samples (101 FFPE and 102 fresh) were tested using Xpert MTB/RIF, including 133 pulmonary tissue samples (65.5%) and 70 extrapulmonary tissue samples (34.5%). Acid-fast bacilli (AFB) culture was used as the diagnostic gold standard. The limit of detection (LOD) and reproducibility were also evaluated for both samples types using contrived specimens. The potential impact of the Xpert MTB PCR assay on tissue samples from AII patients on AII duration was retrospectively assessed.
Using the Xpert MTB/RIF for fresh tissue specimens, the sensitivity was 50% (95% CI, 1.3%–98.7%) and the specificity was 99% (95% CI, 94.5%–99.9%). For FFPE tissue specimens, the sensitivity was 100% (95% CI, 63.1%–100%) and the specificity was 98.3% (95% CI, 95.5%–100%. The LOD was 103 colony-forming units (CFU)/mL for both fresh and FFPE tissue specimens, and the Xpert MTB/RIF was 100% reproducible at concentrations 10 times that of the LOD. With an expected turnaround time of 24 hours, the Xpert MTB PCR could decrease the duration of AII from a median of 8 days to a median of 1 day.
The Xpert MTB/RIF assay offers a valid option for ruling out Mycobacterium tuberculosis complex (MTBC) on tissue samples from oncology patients and for minimizing AII resource utilization.