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An estimated 293,300 healthcare-associated cases of Clostridium difficile infection (CDI) occur annually in the United States. To date, research has focused on developing risk prediction models for CDI that work well across institutions. However, this one-size-fits-all approach ignores important hospital-specific factors. We focus on a generalizable method for building facility-specific models. We demonstrate the applicability of the approach using electronic health records (EHR) from the University of Michigan Hospitals (UM) and the Massachusetts General Hospital (MGH).
We utilized EHR data from 191,014 adult admissions to UM and 65,718 adult admissions to MGH. We extracted patient demographics, admission details, patient history, and daily hospitalization details, resulting in 4,836 features from patients at UM and 1,837 from patients at MGH. We used L2 regularized logistic regression to learn the models, and we measured the discriminative performance of the models on held-out data from each hospital.
Using the UM and MGH test data, the models achieved area under the receiver operating characteristic curve (AUROC) values of 0.82 (95% confidence interval [CI], 0.80–0.84) and 0.75 ( 95% CI, 0.73–0.78), respectively. Some predictive factors were shared between the 2 models, but many of the top predictive factors differed between facilities.
A data-driven approach to building models for estimating daily patient risk for CDI was used to build institution-specific models at 2 large hospitals with different patient populations and EHR systems. In contrast to traditional approaches that focus on developing models that apply across hospitals, our generalizable approach yields risk-stratification models tailored to an institution. These hospital-specific models allow for earlier and more accurate identification of high-risk patients and better targeting of infection prevention strategies.
In the mid-Atlantic region, there is increasing interest in the use of intercropping strategies to establish cover crops in corn cropping systems. However, intercropping may be limited by potential injury to cover crops from residual herbicide programs. Field experiments were conducted from 2013 to 2015 at Pennsylvania, Maryland, and New York locations (n=8) to evaluate the effect of common residual corn herbicides on interseeded red clover and annual ryegrass. Cover crop establishment and response to herbicide treatments varied across sites and years. S-metolachlor, pyroxasulfone, pendimethalin, and dimethenamid-P reduced annual ryegrass biomass relative to the nontreated check, whereas annual ryegrass biomass in acetochlor treatments was no different compared with the nontreated check. The rank order of observed annual ryegrass biomass reduction among chloroacetamide herbicides was S-metolachlor>pyroxasulfone>dimethenamid-P>acetochlor. Annual ryegrass biomass was not reduced by any of the broadleaf control herbicides. Mesotrione reduced red clover biomass 80% compared to the nontreated check. No differences in red clover biomass were observed between saflufenacil, rimsulfuron and atrazine treatments compared to the nontreated check. Red clover was not reduced by any of the grass control herbicides. This research suggests that annual ryegrass and red clover can be successfully interseeded in silt loam soils of Pennsylvania following use of several shorter-lived residual corn herbicides, but further research is needed in areas with soil types other than silt loam or outside of the mid-Atlantic cropping region.
Weed management is a major constraint in organic cropping systems. In 2004, the Cornell Organic Vegetable Cropping Systems Experiment was established in central New York state using a split-plot randomized complete block design with two crop rotation entry points (split-plot factor). Four organic vegetable cropping systems that varied in cropping intensity and tillage (main plot factor) were compared: (1) intensive, (2) intermediate, (3) bio-extensive, and (4) ridge tillage. The basic crop rotation was cabbage, lettuce, potato, and winter squash, with additional short-season crops in the intensive system and with cover crops and fallow substituted for cabbage and potato in the bio-extensive system. In 2014, two uniformity trials were conducted in which oat and then a mixture of sorghum-sudangrass plus Japanese millet were grown uniformly over the entire experiment. Prior to sowing oat, soil samples were collected from each plot and an emergence bioassay was conducted to assess the soil weed seedbank. Crop biomass, weed density, and weed biomass were sampled in the uniformity crops. Soil weed seedbank density was three to four times greater in the intensive, intermediate, and ridge-tillage systems than in the bio-extensive system. The bio-extensive system also had lower weed density and weed biomass in the oat uniformity trial compared with the other three systems. Oat biomass did not differ between the cropping systems. Weed density and biomass in oat were also affected by the crop rotation entry point. Cropping system legacy effects on weed abundance and community composition were greater in the oat than in the sorghum-sudangrass plus Japanese millet uniformity trial. Our results illustrate the effects of different organic vegetable production practices on weed community structure and highlight the value of tilled fallow periods, cover crops, and prevention of weed seed rain for reducing weed populations.
Intercropping with functionally diverse crops can reduce the availability of resources that could otherwise be used by weeds. An experiment was conducted across 6 site-years in New York and Maryland in 2013 and 2014 to examine the effects of functional diversity and crop species richness on weed suppression. We compared four annual crop species that differed in stature and nitrogen acquisition traits: (1) pearl millet, (2) sorghum sudangrass, (3) cowpea, and (4) sunn hemp. Crops were seeded in monoculture and in three- and four-species mixtures using a replacement design in which monoculture seeding rates were divided by the number of species in the intercrop. Crop and weed biomass were sampled at ~45 and 90 d after planting. At the first sampling date, intercrops produced more crop biomass than monocultures in all but 1 site-year; however, weed biomass in intercrops was lower than monocultures in only 1 site-year. By the second sampling date, crop biomass was consistently greater in the intercrops than in the monocultures, and weed biomass was lower in the intercrops than in monocultures in 2 site-years. Although we observed several negative relationships between crop species richness and weed biomass, crop biomass was a more important factor than species richness for suppressing weeds. Despite the weak weed suppression from the two legumes compared with the two grasses, legume crops can provide other benefits, including increased forage quality, soil nitrogen for subsequent crops, and resources for pollinators if allowed to flower. On the other hand, if weed suppression is the top priority, our results suggest that monocultures of high biomass–producing grasses will provide more effective suppression at a lower seed cost than functionally diverse intercrops that include low biomass–producing legumes in warm-season intercrops.
To assess iodine status among pregnant women in rural Zinder, Niger and to compare their status with the iodine status of school-aged children from the same households.
Seventy-three villages in the catchment area of sixteen health centres were randomly selected to participate in the cross-sectional survey.
Salt iodization is mandatory in Niger, requiring 20–60 ppm iodine at the retail level.
A spot urine sample was collected from randomly selected pregnant women (n 662) and one school-aged child from the same household (n 373). Urinary iodine concentration (UIC) was assessed as an indicator of iodine status in both groups. Dried blood spots (DBS) were collected from venous blood samples of pregnant women and thyroglobulin (Tg), thyroid-stimulating hormone and total thyroxine were measured. Iodine content of household salt samples (n 108) was assessed by titration.
Median iodine content of salt samples was 5·5 ppm (range 0–41 ppm), 98 % had an iodine content <20 ppm. Median (interquartile range) UIC of pregnant women and school-aged children was 69·0 (38·1–114·3) and 100·9 (61·2–163·2) µg/l, respectively. Although nearly all pregnant women were euthyroid, their median (interquartile range) DBS-Tg was 34·6 (23·9–49·7) µg/l and 38·4 % had DBS-Tg>40 µg/l.
In this region of Niger, most salt is inadequately iodized. UIC in pregnant women indicated iodine deficiency, whereas UIC of school-aged children indicated marginally adequate iodine status. Thus, estimating population iodine status based solely on monitoring of UIC among school-aged children may underestimate the risk of iodine deficiency in pregnant women.
Cover crops play an important role in agricultural sustainability. Unlike commodity cash crops, however, there has been relatively little cover crop breeding research and development. We conducted an online survey to evaluate: (a) the perspectives of organic and conventional farmers in the USA who use cover crops and (b) the specific cover crop traits that are important to farmers. We recruited participants from both organic and conventional agriculture networks and 69% of respondents reported that they farmed organic land. In addition to demographic data and information on management practices, we quantified farmer perspectives on four winter annual cover crops: (1) Austrian winter pea, (2) crimson clover, (3) hairy vetch and (4) cereal rye. Overall, respondents represented a wide range of states, farm sizes, plant hardiness zones and cash crops produced. Of the 417 full responses received, 87% of respondents reported that they used cover crops. The maximum amount farmers were willing to spend on cover crop seed varied by farmer type: 1% of conventional farmers versus 19% of organic farmers were willing to spend over US$185 ha−1 (US$75 acre−1). Organic and conventional farmers differed in terms of the reasons why they grew cover crops, with organic farmers placing greater value on the ecosystem services from cover crops. More organic (63%) than conventional (51%) farmers agreed that participatory breeding was important for cover crop variety development (P = 0.047). Both groups shared strong support for cover crop research and considered many of the same traits to be important for breeding. For the legume cover crops, nitrogen fixation was considered the most important trait, whereas winter hardiness, early vigor, biomass production and weed suppression were the most important traits for cereal rye. Our results illustrate common interests as well as differences in the perspectives between organic and conventional farmers on cover crops and can be used to inform nascent cover crop breeding efforts.
Poor diet quality contributes to morbidity, including poor brain health outcomes such as cognitive decline and dementia. African Americans and individuals living in poverty may be at greater risk for cognitive decrements from poor diet quality.
Baltimore, MD, USA.
Participants were 2090 African Americans and Whites (57 % female, mean age=47·9 years) who completed two 24 h dietary recalls. We examined cognitive performance and potential interactions of diet quality with race and poverty status using baseline data from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. Healthy Eating Index-2010 (HEI-2010) scores were calculated and interpreted using federal guidelines. A neurocognitive test battery was administered to evaluate cognitive function over several domains.
Linear regression analyses showed that lower HEI-2010 scores were associated with poorer verbal learning and memory (P<0·05) after adjustment for covariates. Diet quality within the sample was poor. Significant interactions of HEI-2010 and poverty status (all P<0·05) indicated that higher diet quality was associated with higher performance on tests of attention and cognitive flexibility, visuospatial ability and perceptual speed among those below the poverty line. No significant race interactions emerged. Higher diet quality was associated with better performance on two measures of verbal learning and memory, irrespective of race and poverty status.
Findings suggest that diet quality and cognitive function are likely related at the population level. Future research is needed to determine whether the association is clinically significant.
We describe bright microwave events that were first detected with the Parkes 64-m telescope at 8.4 or 22 GHz from six active-chromosphere stars. In some flares spectral data were obtained over a large frequency range from simultaneous measurements with the Parkes reflector (8.4 or 22 GHz), the Tidbinbilla interferometer (8.4 and 2.29 GHz), the Fleurs synthesis telescope (1.42 GHz) and the Molonglo Observatory synthesis telescope (0.843 GHz). Data on circular polarization were obtained from the Parkes observations at 8.4 GHz.
The stars were in a wide variety of evolutionary states, ranging from a single pre-main-sequence star (HD 36705), two RS CVn binaries (HD 127535, HD 128171), an Algol (HD 132742) and two apparently single K giants (HD 32918 and HD 196818). Their high brightness temperatures, positive spectral indices and low polarization are consistent with optically thick gyrosynchrotron emission from mildly relativistic electrons with average energies 0.5 to 3 MeV gyrating in inhomogeneous magnetic fields of 5 to 100 G.
We present an overview of the survey for radio emission from active stars that has been in progress for the last six years using the observatories at Fleurs, Molonglo, Parkes and Tidbinbilla. The role of complementary optical observations at the Anglo-Australian Observatory, Mount Burnett, Mount Stromlo and Siding Spring Observatories and Mount Tamborine are also outlined. We describe the different types of star that have been included in our survey and discuss some of the problems in making the radio observations.
Recent meta-analyses of resting-state networks in major depressive disorder (MDD) implicate network disruptions underlying cognitive and affective features of illness. Heterogeneity of findings to date may stem from the relative lack of data parsing clinical features of MDD such as phase of illness and the burden of multiple episodes.
Resting-state functional magnetic resonance imaging data were collected from 17 active MDD and 34 remitted MDD patients, and 26 healthy controls (HCs) across two sites. Participants were medication-free and further subdivided into those with single v. multiple episodes to examine disease burden. Seed-based connectivity using the posterior cingulate cortex (PCC) seed to probe the default mode network as well as the amygdala and subgenual anterior cingulate cortex (sgACC) seeds to probe the salience network (SN) were conducted.
Young adults with remitted MDD demonstrated hyperconnectivity of the left PCC to the left inferior frontal gyrus and of the left sgACC to the right ventromedial prefrontal cortex (PFC) and left hippocampus compared with HCs. Episode-independent effects were observed between the left PCC and the right dorsolateral PFC, as well as between the left amygdala and right insula and caudate, whereas the burden of multiple episodes was associated with hypoconnectivity of the left PCC to multiple cognitive control regions as well as hypoconnectivity of the amygdala to large portions of the SN.
This is the first study of a homogeneous sample of unmedicated young adults with a history of adolescent-onset MDD illustrating brain-based episodic features of illness.
The association between harmful use of alcohol and HIV infection is well documented. To address this dual epidemic, the US President's Emergency Plan for AIDS Relief (PEPFAR) developed and implemented a multi-pronged approach primarily in Namibia and Botswana. We present the approach and preliminary results of the public health investigative and programmatic activities designed, initiated and supported by PEPFAR to combat the harmful use of alcohol and its association as a driver of HIV morbidity and mortality from 2008 to 2013.
PEPFAR supported comprehensive alcohol programming using a matrix model approach that combined the socio-ecological framework and the Alcohol Misuse Prevention and Intervention Continuum. This structure enabled seven component objectives: (1) to quantify harmful use of alcohol through rapid assessments; (2) to develop and evaluate alcohol-based interventions; (3) to promote screening programs and alcohol abuse resource services; (4) to support stakeholder networks; (5) to support policy interventions and (6) structural interventions; and (7) to institutionalize universal prevention messages.
Targeted PEPFAR support for alcohol activities resulted in several projects to address harmful alcohol use and HIV. Components are graphically conceptualized within the matrix model, demonstrating the intersections between primary, secondary and tertiary prevention activities and individual, interpersonal, community, and societal factors. Key initiative successes included leveraging alcohol harm prevention activities that enabled projects to be piloted in healthcare settings, schools, communities, and alcohol outlets. Primary challenges included the complexity of multi-sectorial programming, varying degrees of political will, and difficulties monitoring outcomes over the short duration of the program.
We examine the game theoretic properties of a model of crime first introduced by Short et al. (2010 Phys. Rev. E82, 066114) as the SBD Adversarial Game. We identify the rationalizable strategies and one-shot equilibria under multiple equilibrium refinements. We further show that SBD's main result about the effectiveness of defecting-punishers (“Informants”) in driving the system to evolve to the cooperative equilibrium under an imitation dynamic generalizes to a best response dynamic, though only under certain parameter regimes. The nature of this strategy's role, however, differs significantly between the two dynamics: in the SBD imitation dynamic, Informants are sufficient but not necessary to achieve the cooperative equilibrium, while under the best response dynamic, Informants are necessary but not sufficient for convergence to cooperation. Since a policy of simply converting citizens to Informants will not guarantee success under best response dynamics, we identify alternative strategies that may help the system reach cooperation in this case, e.g., the use of moderate but not too severe punishments on criminals.
Social context has a major influence on the detection and treatment of youth mental and substance use disorders in socioeconomically disadvantaged urban areas, particularly where gang culture, community violence, normalisation of drug use and repetitive maladaptive family structures prevail. This paper aims to examine how social context influences the development, identification and treatment of youth mental and substance use disorders in socioeconomically disadvantaged urban areas from the perspectives of health care workers.
Semi-structured interviews were conducted with health care workers (n=37) from clinical settings including: primary care, secondary care and community agencies and analysed thematically using Bronfenbrenner’s Ecological Theory to guide analysis.
Health care workers’ engagement with young people was influenced by the multilevel ecological systems within the individual’s social context which included: the young person’s immediate environment/‘microsystem’ (e.g., family relationships), personal relationships in the ‘mesosystem’ (e.g., peer and school relationships), external factors in the young person’s local area context/‘exosystem’ (e.g., drug culture and criminality) and wider societal aspects in the ‘macrosystem’ (e.g., mental health policy, health care inequalities and stigma).
In socioeconomically disadvantaged urban areas, social context, specifically the micro-, meso-, exo-, and macro-system impact both on the young person’s experience of mental health or substance use problems and services, which endeavour to address these problems. Interventions that effectively identify and treat these problems should reflect the additional challenges posed by such settings.
Material extrusion 3D printing (ME3DP) based on fused deposition modeling (FDM) technology is currently the most commonly used additive manufacturing method. However, ME3DP suffers from a limitation of compatible materials and typically relies upon amorphous thermoplastics, such as acrylonitrile butadiene styrene (ABS). The work presented here demonstrates the development and implementation of binary and ternary polymeric blends for ME3DP. Multiple blends of acrylonitrile butadiene styrene (ABS), styrene ethylene butadiene styrene (SEBS), and ultrahigh molecular weight polyethylene (UHMWPE) were created through a twin screw compounding process to produce novel polymer blends compatible with ME3DP platforms. Mechanical testing and fractography were used to characterize the different physical properties of these new blends. Though the new blends possessed different physical properties, compatibility with ME3DP platforms was maintained. Also, a decrease in surface roughness of a standard test piece was observed for some blends as compared with ABS.