Vegetation light use efficiency is a key physiological parameter at the canopy scale, and at the daily time step is a component of remote sensing algorithms for scaling gross primary production (GPP) ...and net primary production (NPP) over regional to global domains. For the purposes of calibrating and validating the light use efficiency (εg) algorithms, the components of εg– absorbed photosynthetically active radiation (APAR) and ecosystem GPP – must be measured in a variety of environments. Micrometeorological and mass flux measurements at eddy covariance flux towers can be used to estimate APAR and GPP, and the emerging network of flux tower sites offers the opportunity to investigate spatial and temporal patterns in εg at the daily time step. In this study, we examined the relationship of daily GPP to APAR, and relationships of εg to climatic variables, at four micrometeorological flux tower sites – an agricultural field, a tallgrass prairie, a deciduous forest, and a boreal forest. The relationship of GPP to APAR was close to linear at the tallgrass prairie site but more nearly hyperbolic at the other sites. The sites differed in the mean and range of daily εg, with higher values associated with the agricultural field than the boreal forest. εg decreased with increasing APAR at all sites, a function of mid‐day saturation of GPP and higher εg under overcast conditions. εg was generally not well correlated with vapor pressure deficit or maximum daily temperature. At the agricultural site, a εg decline towards the end of the growing season was associated with a decrease in foliar nitrogen concentration. At the tallgrass prairie site, a decline in εg in August was associated with soil drought. These results support inclusion of parameters for cloudiness and the phenological status of the vegetation, as well as use of biome‐specific parameterization, in operational εg algorithms.
Recovery from serious neurological injury requires substantial rewiring of neural circuits. Precisely-timed electrical stimulation could be used to restore corrective feedback mechanisms and promote ...adaptive plasticity after neurological insult, such as spinal cord injury (SCI) or stroke. This study provides the first evidence that closed-loop vagus nerve stimulation (CLV) based on the synaptic eligibility trace leads to dramatic recovery from the most common forms of SCI. The addition of CLV to rehabilitation promoted substantially more recovery of forelimb function compared to rehabilitation alone following chronic unilateral or bilateral cervical SCI in a rat model. Triggering stimulation on the most successful movements is critical to maximize recovery. CLV enhances recovery by strengthening synaptic connectivity from remaining motor networks to the grasping muscles in the forelimb. The benefits of CLV persist long after the end of stimulation because connectivity in critical neural circuits has been restored.
Nuclear recoil backgrounds are one of the most dangerous backgrounds for many dark matter experiments. A primary source of nuclear recoils is radiogenic neutrons produced in the detector material ...itself. These neutrons result from fission and (α,n) reactions originating from uranium and thorium contamination. In this paper, we discuss neutron yields from these sources. We compile a list of (α,n) yields for many materials common in low-background detectors, calculated using NeuCBOT (Neutron Calculator Based On TALYS), a new tool introduced in this paper, available at https://github.com/shawest/neucbot. These calculations are compared to computations made using data compilations and SOURCES-4C.
The authors review studies relating to the immune responses evoked by laparoscopic surgery.
Laparoscopic surgery has gained rapid acceptance based on clinical grounds. Patients benefit from faster ...recovery, decreased pain, and quicker return to normal activities. Only more recently have attempts been made to identify the metabolic and immune responses that may underlie this clinical success. The immune responses to laparoscopy are now being evaluated in relation to the present knowledge of immune responses to traditional laparotomy and surgery in general.
A review of the published literature of the immune and metabolic responses to laparoscopy was performed. Laparoscopic surgery is compared with the traditional laparotomy on the basis of local and systemic immune responses and patterns of tumor growth. The impact of pneumoperitoneum and insufflation gases on the immune response is also reviewed.
The systemic immune responses for surgery in general may not apply to laparoscopic surgery. The body's response to laparoscopy is one of lesser immune activation as opposed to immunosuppression.
The purpose of this study was to gain insight into the pathophysiologic processes of severe lower-abdominal or inguinal pain
in high-performance athletes. We evaluated 276 patients; 175 underwent ...pelvic floor repairs. Of the 157 athletes who had not
undergone previous surgery, 124 (79%) participated at a professional or other highly competitive level, and 138 patients (88%)
had adductor pain that accompanied the lower-abdominal or inguinal pain. More patients underwent related adductor releases
during the later operative period in the series. Evaluation revealed 38 other abnormalities, including severe hip problems
and malignancies. There were 152 athletes (97%) who returned to previous levels of performance. The syndrome was uncommon
in women and the results were less predictable in nonathletes. A distinct syndrome of lower-abdominal/adductor pain in male
athletes appears correctable by a procedure designed to strengthen the anterior pelvic floor. The location and pattern of
pain and the operative success suggest the cause to be a combination of abdominal hyperextension and thigh hyperabduction,
with the pivot point being the pubic symphysis. Diagnosis of âathletic pubalgiaâ and surgery should be limited to a select
group of high-performance athletes. The consideration of other causes of groin pain in the patient is critical.
The MiniBooNE Collaboration observes unexplained electronlike events in the reconstructed neutrino energy range from 200 to 475 MeV. With 6.46x10;{20} protons on target, 544 electronlike events are ...observed in this energy range, compared to an expectation of 415.2+/-43.4 events, corresponding to an excess of 128.8+/-20.4+/-38.3 events. The shape of the excess in several kinematic variables is consistent with being due to either nu_{e} and nuover _{e} charged-current scattering or nu_{mu} neutral-current scattering with a photon in the final state. No significant excess of events is observed in the reconstructed neutrino energy range from 475 to 1250 MeV, where 408 events are observed compared to an expectation of 385.9+/-35.7 events.
To summarize and classify the evidence for the use of endovascular techniques in the treatment of patients with acute ischemic stroke.
Recommendations previously published by the American Heart ...Association (AHA) (Guidelines for the early management of adults with ischemic stroke (Circulation 2007) and Scientific statement indications for the performance of intracranial endovascular neurointerventional procedures (Circulation 2009)) were vetted and used as a foundation for the current process. Building on this foundation, a critical review of the literature was performed to evaluate evidence supporting the endovascular treatment of acute ischemic stroke. The assessment was based on guidelines for evidence based medicine proposed by the Stroke Council of the AHA and the University of Oxford, Centre for Evidence Based Medicine (CEBM). Procedural safety, technical efficacy and impact on patient outcomes were specifically examined.
There are sparse data on the frequency of venous thromboembolism in patients with various types of cancer. We sought to determine the incidence and relative risk of venous thromboembolism, pulmonary ...embolism, and deep venous thrombosis in patients with malignancies.
The number of patients discharged with a diagnostic code for 19 types of malignancies, pulmonary embolism or deep venous thrombosis from 1979 through 1999 was obtained from the National Hospital Discharge Survey. Patients studied were men and women of all ages and races.
In patients with any of the 19 malignancies studied, 827
000 of 40
787
000 (2.0%) had venous thromboembolism, which was twice the incidence in patients without these malignancies, 6
854
000 of 662
309
000 (1.0 %). The highest incidence of venous thromboembolism was in patients with carcinoma of the pancreas, 51
000 of 1
176
000 (4.3%), and the lowest incidences were in patients with carcinoma of the bladder and carcinoma of the lip, oral cavity or pharynx. The overall incidences of pulmonary embolism and deep venous thrombosis were also twice the rates in noncancer patients. Incidences with cancer were not age dependent. The incidence of venous thromboembolism in patients with cancer began to increase in the late 1980s.
Patients with cancer had twice the incidence of venous thromboembolism, pulmonary embolism and deep venous thrombosis as patients without cancer. The incidence of venous thromboembolism, pulmonary embolism and deep venous thrombosis associated with cancer differed according to the type of cancer, was comparable in elderly and younger patients, and increased in the late 1980s and 1990s.
The high rate of severe cytomegalovirus (CMV) disease after bone marrow transplantation (BMT) is related to the profound immunodeficiency posttransplant. Because cytotoxic T lymphocytes (CTL) have ...been implicated in resistance to viral infections, we examined the restoration of the CMV-specific CTL response in 20 patients who received bone marrow from HLA-matched, CMV-seropositive donors. Blood specimens were obtained from patients at 1,2, and 3 months after BMT and from the donors on a single occasion. Peripheral blood mononuclear cells were cocultured with CMV-infected donor-derived fibroblasts for 2 weeks and then tested for cytotoxicity against CMV-infected and uninfected autologous or HLA-mismatched fibroblasts. Cytolytic activity was detected in all 20 donors, with specificity for autologous CMV-infected targets demonstrable in 17 (median CMV-specific lysis at an effector:target ratio of 15:1 was 32%, range 18% to 83%). Specific lysis was mediated by CD8+, class l-restricted T cells, as shown by inhibition with anticlass I monoclonal antibody and by selective depletion of effector cells. By contrast, CMV-specific CTL were detected in only 10 of 20 patients after BIVJT (median lysis 29% at 3 months post-BMT). None of these 10 patients developed CMV pneumonia, whereas 6 of the 10 patients with an undetectable CMV-specific CTL response after BMT died with CMV pneumonia. These results demonstrate that restoration of CMV-specific CTL responses may require an extended time period after BMT in some patients, and that such patients are at increased risk of developing severe CMV disease. Approaches to reconstitute CMV immunity in BMT patients by adoptive transfer of CMV-specific CD8+ CTL clones derived from the bone marrow donor are now being pursued.
Operational monitoring of global terrestrial gross primary production (GPP) and net primary production (NPP) is now underway using imagery from the satellite-borne Moderate Resolution Imaging ...Spectroradiometer (MODIS) sensor. Evaluation of MODIS GPP and NPP products will require site-level studies across a range of biomes, with close attention to numerous scaling issues that must be addressed to link ground measurements to the satellite-based carbon flux estimates. Here, we report results of a study aimed at evaluating MODIS NPP/GPP products at six sites varying widely in climate, land use, and vegetation physiognomy. Comparisons were made for twenty-five 1 km2 cells at each site, with 8-day averages for GPP and an annual value for NPP. The validation data layers were made with a combination of ground measurements, relatively high resolution satellite data (Landsat Enhanced Thematic Mapper Plus at ~30 m resolution), and process-based modeling. There was strong seasonality in the MODIS GPP at all sites, and mean NPP ranged from 80 g C m-2 yr-1 at an arctic tundra site to 550 g C m-2 yr-1 at a temperate deciduous forest site. There was not a consistent over- or underprediction of NPP across sites relative to the validation estimates. The closest agreements in NPP and GPP were at the temperate deciduous forest, arctic tundra, and boreal forest sites. There was moderate underestimation in the MODIS products at the agricultural field site, and strong overestimation at the desert grassland and at the dry coniferous forest sites. Analyses of specific inputs to the MODIS NPP/GPP algorithm - notably the fraction of photosynthetically active radiation absorbed by the vegetation canopy, the maximum light use efficiency (LUE), and the climate data - revealed the causes of the over- and underestimates. Suggestions for algorithm improvement include selectively altering values for maximum LUE (based on observations at eddy covariance flux towers) and parameters regulating autotrophic respiration.
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