Atmospheric aerosols, suspended solid and liquid particles, act as nucleation sites for cloud drop formation, affecting clouds and cloud properties-ultimately influencing the cloud dynamics, ...lifetime, water path, and areal extent that determine the reflectivity (albedo) of clouds. The concentration N d of droplets in clouds that influences planetary albedo is sensitive to the availability of aerosol particles on which the droplets form. Natural aerosol concentrations affect not only cloud properties themselves but also modulate the sensitivity of clouds to changes in anthropogenic aerosols. It is shown that modeled natural aerosols, principally marine biogenic primary and secondary aerosol sources, explain more than half of the spatiotemporal variability in satellite-observed N d. Enhanced N d is spatially correlated with regions of high chlorophyll a, and the spatiotemporal variability in N d is found to be driven primarily by high concentrations of sulfate aerosol at lower Southern Ocean latitudes (35(o) to 45(o)S) and by organic matter in sea spray aerosol at higher latitudes (45(o) to 55(o)S). Biogenic sources are estimated to increase the summertime mean reflected solar radiation in excess of 10 W m(-2) over parts of the Southern Ocean, which is comparable to the annual mean increases expected from anthropogenic aerosols over heavily polluted regions of the Northern Hemisphere.
Roots are vital to plant performance because they acquire resources from the soil and provide anchorage. However, it remains difficult to assess root system size and distribution because roots are ...inaccessible in the soil. Existing methods to phenotype entire root systems range from slow, often destructive, methods applied to relatively small numbers of plants in the field to rapid methods that can be applied to large numbers of plants in controlled environment conditions. Much has been learned recently by extensive sampling of the root crown portion of field-grown plants. But, information on large-scale genetic and environmental variation in the size and distribution of root systems in the field remains a key knowledge gap. Minirhizotrons are the only established, non-destructive technology that can address this need in a standard field trial. Prior experiments have used only modest numbers of minirhizotrons, which has limited testing to small numbers of genotypes or environmental conditions. This study addressed the need for methods to install and collect images from thousands of minirhizotrons and thereby help break the phenotyping bottleneck in the field.
Over three growing seasons, methods were developed and refined to install and collect images from up to 3038 minirhizotrons per experiment. Modifications were made to four tractors and hydraulic soil corers mounted to them. High quality installation was achieved at an average rate of up to 84.4 minirhizotron tubes per tractor per day. A set of four commercially available minirhizotron camera systems were each transported by wheelbarrow to allow collection of images of mature maize root systems at an average rate of up to 65.3 tubes per day per camera. This resulted in over 300,000 images being collected in as little as 11 days for a single experiment.
The scale of minirhizotron installation was increased by two orders of magnitude by simultaneously using four tractor-mounted, hydraulic soil corers with modifications to ensure high quality, rapid operation. Image collection can be achieved at the corresponding scale using commercially available minirhizotron camera systems. Along with recent advances in image analysis, these advances will allow use of minirhizotrons at unprecedented scale to address key knowledge gaps regarding genetic and environmental effects on root system size and distribution in the field.
Myelin-associated inhibitory factors (MAIFs) are inhibitors of CNS axonal regeneration following injury. The Nogo receptor complex, composed of the Nogo-66 receptor 1 (NgR1), neurotrophin p75 ...receptor (p75), and LINGO-1, represses axon regeneration upon binding to these myelin components. The limited expression of p75 to certain types of neurons and its temporal expression during development prompted speculation that other receptors are involved in the NgR1 complex. Here, we show that an orphan receptor in the TNF family called TAJ, broadly expressed in postnatal and adult neurons, binds to NgR1 and can replace p75 in the p75/NgR1/LINGO-1 complex to activate RhoA in the presence of myelin inhibitors. In vitro exogenously added TAJ reversed neurite outgrowth caused by MAIFs. Neurons from
Taj-deficient mice were more resistant to the suppressive action of the myelin inhibitors. Given the limited expression of p75, the discovery of TAJ function is an important step for understanding the regulation of axonal regeneration.
Background
Diseases affecting the internal umbilical remnant are common in foals. Ultrasound is used to diagnose abnormalities of these structures, and to monitor treatment. However, little is known ...about the progression of normal internal umbilical remnant regression.
Objectives
To document normal regression of the umbilical remnant in foals over the first 6 weeks of life.
Study design
Prospective, longitudinal cohort study.
Methods
Weekly ultrasound examinations were performed beginning at 1 day of age in 34 healthy Standardbred foals. The umbilical vein was measured in cross section just cranial to the external umbilicus, at the level of the liver and midway between these points. The umbilical arteries were measured in cross section just caudal to the external umbilicus, at the apex of the bladder and at the midpoint of the bladder. The urachus was imaged longitudinally as it exited the bladder. Reduction in size over time was evaluated as percentage change in diameter.
Results
Structure diameter decreased linearly over time. The largest measurements were at 24 hours of age with a median umbilical vein diameter of 0.83 cm (IQR 0.77‐1.02 cm), median umbilical artery diameter of 0.61 cm (IQR 0.56‐0.70 cm) and median urachal diameter of 1.07 cm (IQR 1.02‐1.14 cm). There was a significant reduction in diameter for all structures (16.0%‐21.9%; corrected P < .001) within the first week of life.
Main limitations
All foals were of a single breed, and examinations and measurements were performed by multiple individuals.
Conclusions
The internal umbilical remnants (umbilical vein/arteries, and urachus) rapidly regress over the first few weeks of life. The median internal umbilical remnant diameters reported here are smaller than previously reported values, emphasising the importance of accounting for age when diagnosing umbilical abnormalities. In a healthy Standardbred foal, normal structures are difficult to definitively identify via transcutaneous ultrasound by 5‐6 weeks of age.
The space flight environment is known to induce bone loss and, subsequently, calcium loss. The longer the mission, generally the more bone and calcium are lost. This review provides a history of bone ...and calcium studies related to space flight and highlights issues related to calcium excretion that the space program must consider so that urine can be recycled. It also discusses a novel technique using natural stable isotopes of calcium that will be helpful in the future to determine calcium and bone balance during space flight.
Composite analyses of the atmosphere over the central United States during elevated thunderstorms producing heavy rainfall are presented. Composites were created for five National Weather Service ...County Warning Areas (CWAs) in the region. Events studied occurred during the warm season (April–September) during 1979–2012. These CWAs encompass the region determined previously to experience the greatest frequency of elevated thunderstorms in the United States. Composited events produced rainfall of >50 mm 24 hr−1 within the selected CWA. Composites were generated for the 0–3 hr period prior to the heaviest rainfall, 6–9 hours prior to it, and 12–15 hours prior to it. This paper focuses on the Pleasant Hill, Missouri (EAX) composites, as all CWA results were similar; also these analyses focus on the period 0–3 hours prior to event occurrence. These findings corroborate the findings of previous authors. What is offered here that is unique is (1) a measure of the interquartile range within the composite mean fields, allowing for discrimination between variable fields that provided a strong reliable signal, from those that may appear strong but possess large variability, and (2) composite soundings of two subclasses of elevated thunderstorms. Also, a null case (one that fits the composite but failed to produce significant rainfall) is also examined for comparison.
Compositional characterization of biomass is vital for the biofuel industry. Traditional wet chemistry-based methods for analyzing biomass composition are laborious, time-consuming, and require ...extensive use of chemical reagents as well as highly skilled personnel. In this study, near-infrared (NIR) spectroscopy was used to quickly assess the composition of above-ground vegetative biomass from 113 diverse, photoperiod-sensitive, biomass-type sorghum (Sorghum bicolor) accessions cultivated under field conditions in Central Illinois. Biomass samples were analyzed using NIR spectra collected in the spectral range of 867–2536 nm, with their chemical compositions determined following the National Renewable Energy Laboratory (NREL) protocol. Advanced spectral pre-treatment and band selection techniques were utilized to develop calibration models using partial least squares regression (PLSR). The models' effectiveness was assessed through cross-validation and independent data tests. The predictions for moisture, ash, extractives, glucan, xylan, acid-soluble lignin (ASL), acid-insoluble lignin (AIL), and total lignin were accurate and reliable, demonstrating the capability of NIR spectroscopy to provide rapid and precise characterization of sorghum biomass. The results demonstrated that NIR spectroscopy is an efficient tool for rapidly characterizing sorghum biomass, making it a sustainable option for screening desirable feedstock for biofuel or bioproduct production.
•NIR efficiently characterizes sorghum biomass rapidly and at high throughput.•Spectral pre-treatments and band selection enhanced PLSR model robustness.•Validations confirmed the developed models' effectiveness.•Sustainable nature of NIR supports environmentally friendly practices.
The control of myelination by oligodendrocytes in the CNS is poorly understood. Here we show that LINGO-1 is an important negative regulator of this critical process. LINGO-1 is expressed in ...oligodendrocytes. Attenuation of its function by dominant-negative LINGO-1, LINGO-1 RNA-mediated interference (RNAi) or soluble human LINGO-1 (LINGO-1-Fc) leads to differentiation and increased myelination competence. Attenuation of LINGO-1 results in downregulation of RhoA activity, which has been implicated in oligodendrocyte differentiation. Conversely, overexpression of LINGO-1 leads to activation of RhoA and inhibition of oligodendrocyte differentiation and myelination. Treatment of oligodendrocyte and neuron cocultures with LINGO-1-Fc resulted in highly developed myelinated axons that have internodes and well-defined nodes of Ranvier. The contribution of LINGO-1 to myelination was verified in vivo through the analysis of LINGO-1 knockout mice. The ability to recapitulate CNS myelination in vitro using LINGO-1 antagonists and the in vivo effects seen in the LINGO-1 knockout indicate that LINGO-1 signaling may be critical for CNS myelination.
Known as "Valley Fever," coccidiomycosis is a soil-borne, fungal infection predominately found in endemic regions of the southwestern United States and Latin America. While most infected individuals ...are asymptomatic, <1% of patients have hematogenous seeding of bone, skin, and soft tissue. When the musculoskeletal system is involved, the knee is most commonly affected, although infection has been described in the spine, hand, wrist, ankle, foot, and pelvis. Treatment typically includes a combination of surgical debridement and antifungal treatment.An 11-year-old boy presented with a 7-month history of left anterior knee pain. Physical examination revealed mild knee effusion and quadriceps atrophy with focal tenderness to palpation to the distal pole of the patella. Laboratory studies were unremarkable and plain radiographs revealed a radiolucency in the inferomedial aspect of the patella. Magnetic resonance imaging revealed a corresponding focus of increased T2 signal with sclerotic margins and peripheral edema within the patella. Open biopsy with curettage confirmed coccidiomycosis, and the patient was successfully managed with long-term antifungal antibiotics.To our knowledge, this article presents the first known case of coccidioidal osteomyelitis of the patella.
The prevalence of burnout and depressive symptoms is high among physician trainees.
What is the burden of burnout and depressive symptoms among fellows training in pulmonary and critical care ...medicine (PCCM) and what are associated individual fellow, program, and institutional characteristics?
We conducted a cross-sectional electronic survey of fellows enrolled in pulmonary, PCCM, and critical care medicine training programs in the United States to assess burnout and depressive symptoms. Burnout symptoms were measured using the Maslach Burnout Index two-item measure. The two-item Primary Care Evaluation of Mental Disorders Procedure was used to screen for depressive symptoms. For each of the two outcomes (burnout and depressive symptoms), we constructed three multivariate logistic regression models to assess individual fellow characteristics, program structure, and institutional polices associated with either burnout or depressive symptoms.
Five hundred two of the 976 fellows who received the survey completed it-including both outcome measures-giving a response rate of 51%. Fifty percent of fellows showed positive results for either burnout or depressive symptoms, with 41% showing positive results for depressive symptoms, 32% showing positive results for burnout, and 23% showing positive results for both. Reporting a coverage system in the case of personal illness or emergency (adjusted OR aOR, 0.44; 95% CI, 0.26-0.73) and access to mental health services (aOR, 0.14; 95% CI, 0.04-0.47) were associated with lower odds of burnout. Financial concern was associated with higher odds of depressive symptoms (aOR, 1.13; 95% CI, 1.05-1.22). Working more than 70 hours in an average clinical week and the burdens of electronic health record (EHR) documentation were associated with a higher odds of both burnout and depressive symptoms.
Given the high prevalence of burnout and depressive symptoms among fellows training in PCCM, an urgent need exists to identify solutions that address this public health crisis. Strategies such as providing an easily accessible coverage system, access to mental health resources, reducing EHR burden, addressing work hours, and addressing financial concerns among trainees may help to reduce burnout or depressive symptoms and should be studied further by the graduate medical education community.
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