NASA’s InSight mission to Mars will measure seismic signals to determine the planet’s interior structure. These highly sensitive seismometers are susceptible to corruption of their measurements by ...environmental changes. Magnetic fields, atmosphere pressure changes, and local winds can all induce apparent changes in the seismic records that are not due to propagating ground motions. Thus, InSight carries a set of sensors called the Auxiliary Payload Sensor Suite (APSS) which includes a magnetometer, an atmospheric pressure sensor, and a pair of wind and air temperature sensors. In the case of the magnetometer, knowledge of the amplitude of the fluctuating magnetic field at the InSight lander will allow the separation of seismic signals from potentially interfering magnetic signals of either natural or spacecraft origin. To acquire such data, a triaxial fluxgate magnetometer was installed on the deck of the lander to obtain magnetic records at the same cadence as the seismometer. Similarly, a highly sensitive pressure sensor is carried by InSight to enable the removal of local ground-surface tilts due to advecting pressure perturbations. Finally, the local winds (speed and direction) and air temperature are estimated using a hot-film wind sensor with heritage from REMS on the Curiosity rover. When winds are too high, seismic signals can be ignored or discounted. Herein we describe the APSS sensor suite, the test programs for its components, and the possible additional science investigations it enables.
The Plumbing of Land Surface Models Best, M. J.; Abramowitz, G.; Johnson, H. R. ...
Journal of hydrometeorology,
06/2015, Letnik:
16, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The Protocol for the Analysis of Land Surface Models (PALS) Land Surface Model Benchmarking Evaluation Project (PLUMBER) was designed to be a land surface model (LSM) benchmarking intercomparison. ...Unlike the traditional methods of LSM evaluation or comparison, benchmarking uses a fundamentally different approach in that it sets expectations of performance in a range of metrics a priori—before model simulations are performed. This can lead to very different conclusions about LSM performance. For this study, both simple physically basedmodels and empirical relationships were used as the benchmarks. Simulations were performed with 13 LSMs using atmospheric forcing for 20 sites, and then model performance relative to these benchmarks was examined. Results show that even for commonly used statistical metrics, the LSMs’ performance varies considerably when compared to the different benchmarks. All models outperform the simple physically based benchmarks, but for sensible heat flux the LSMs are themselves outperformed by an out-of-sample linear regression against downward shortwave radiation. While moisture information is clearly central to latent heat flux prediction, the LSMs are still outperformed by a three-variable nonlinear regression that uses instantaneous atmospheric humidity and temperature in addition to downward shortwave radiation. These results highlight the limitations of the prevailing paradigm of LSM evaluation that simply compares an LSM to observations and to other LSMs without a mechanism to objectively quantify the expectations of performance. The authors conclude that their results challenge the conceptual view of energy partitioning at the land surface.
Abstract The Winchcombe meteorite is a CM chondrite breccia composed of eight distinct lithological units plus a cataclastic matrix. The degree of aqueous alteration varies between intensely altered ...CM2.0 and moderately altered CM2.6. Although no lithology dominates, three heavily altered rock types (CM2.1–2.3) represent >70 area%. Tochilinite–cronstedtite intergrowths (TCIs) are common in several lithologies. Their compositions can vary significantly, even within a single lithology, which can prevent a clear assessment of alteration extent if only TCI composition is considered. We suggest that this is due to early alteration under localized geochemical microenvironments creating a diversity of compositions and because later reprocessing was incomplete, leaving a record of the parent body's fluid history. In Winchcombe, the fragments of primary accretionary rock are held within a cataclastic matrix (~15 area%). This material is impact‐derived fallback debris. Its grain size and texture suggest that the disruption of the original parent asteroid responded by intergranular fracture at grain sizes <100 μm, while larger phases, such as whole chondrules, splintered apart. Re‐accretion formed a poorly lithified body. During atmospheric entry, the Winchcombe meteoroid broke apart with new fractures preferentially cutting through the weaker cataclastic matrix and separating the breccia into its component clasts. The strength of the cataclastic matrix imparts a control on the survival of CM chondrite meteoroids. Winchcombe's unweathered state and diversity of lithologies make it an ideal sample for exploring the geological history of the CM chondrite group.
Quantal release of the principal excitatory neurotransmitter glutamate requires a mechanism for its transport into secretory vesicles. Within the brain, the complementary expression of vesicular ...glutamate transporters (VGLUTs) 1 and 2 accounts for the release of glutamate by all known excitatory neurons. We now report the identification of VGLUT3 and its expression by many cells generally considered to release a classical transmitter with properties very different from glutamate. Remarkably, subpopulations of inhibitory neurons as well as cholinergic interneurons, monoamine neurons, and glia express VGLUT3. The dendritic expression of VGLUT3 by particular neurons also indicates the potential for retrograde synaptic signaling. The distribution and subcellular location of VGLUT3 thus suggest novel modes of signaling by glutamate.
Background. In the Strategic Timing of Antiretroviral Treatment (START) study, immediate combination antiretroviral therapy (cART) initiation reduced cancer risk by 64%. We hypothesized that risk ...reduction was higher for infection-related cancer and determined by differences in CD4 cell counts and human immunodeficiency virus (HIV) RNA between the study arms. Methods. Incident malignancies in START were categorized into infection-related and infection-unrelated cancer. We used Cox models to assess factors associated with both cancer categories. We used sequential adjustment for baseline covariates, cancer risk factors, and HIV-specific variables to investigate potential mediators of cancer risk reduction with immediate cART. Results. There were 14 cancers among persons randomized to immediate cART (6 infection-related and 8 infection-unrelated) and 39 cancers in the deferred arm (23 infection-related and 16 infection-unrelated); hazard ratios of immediate vs deferred cART initiation were 0.26 (95% confidence interval CI, .11-.64) for infection-related and 0.49 (95% CI, .21-1.15) for infection-unrelated cancer. Independent predictors of infection-related cancer were older age, higher body mass index, low- to middle-income region, HIV RNA, and baseline CD8 cell count. Older age and baseline CD8 cell count were independent predictors of infection-unrelated cancer. Adjustment for latest HIV RNA level had little impact on the protective effect of immediate cART on infection-related cancer. Adjustment for latest HIV RNA level, but not for CD4 cell count or cancer risk factors, attenuated the effect of immediate cART on infection-unrelated cancer. Conclusions. Immediate cART initiation significantly reduces risk of cancer. Although limited by small sample size, this benefit does not appear to be solely attributable to HIV RNA suppression and may be also mediated by other mechanisms.
Clinical islet transplantation achieves insulin independence in selected patients, yet current methods for extracting islets from their surrounding pancreatic matrix are suboptimal. The islet ...basement membrane (BM) influences islet function and survival and is a critical marker of islet integrity following rodent islet isolation. No studies have investigated the impact of islet isolation on BM integrity in human islets, which have a unique duplex structure. To address this, samples were taken from 27 clinical human islet isolations (donor age 41–59, BMI 26–38, cold ischemic time < 10 h). Collagen IV, pan‐laminin, perlecan and laminin‐α5 in the islet BM were significantly digested by enzyme treatment. In isolated islets, laminin‐α5 (found in both layers of the duplex BM) and perlecan were lost entirely, with no restoration evident during culture. Collagen IV and pan‐laminin were present in the disorganized BM of isolated islets, yet a significant reduction in pan‐laminin was seen during the initial 24 h culture period. Islet cytotoxicity increased during culture. Therefore, the human islet BM is substantially disrupted during the islet isolation procedure. Islet function and survival may be compromised as a consequence of an incomplete islet BM, which has implications for islet survival and transplanted graft longevity.
This study characterizes the human islet basement membrane before and after islet isolation, demonstrating that substantial disruption of both layers of the duplex basement membrane occurs during the procedure, potentially compromising islet survival.
Drop out from upper secondary school represents a risk for the future health and wellbeing of young people. Strengthening of psychosocial aspects of the learning environment may be an effective ...strategy to promote completion of upper secondary school. This paper is a study protocol of a school based cluster randomized controlled trial (RCT) evaluating two school-based interventions, namely the Dream School Program (DSP) and the Mental Health Support Team (MHST). The interventions aim to improve psychosocial learning environments and subsequently school achievements and decrease drop-out and absence.
The COMPLETE RCT is aimed at youth in upper secondary school, grade 1 (age 15-16 years), and examines the effect of the combination of the DSP and the MHST; and the DSP only, compared with a comparison group on the following primary outcomes: student completion, presence, average grade, and self-reported mental health. Seventeen upper secondary schools from four counties in Norway were randomized to one of the three arms: 1) DSP and MHST; 2) DSP; and 3) comparison (offered DSP intervention in 2018/2019). The study will evaluate the interventions based on information from two cohorts of students (cohort 1 (C1) and cohort 2 (C2)). For C1, data was collected at baseline (August 2016), and at first follow-up seven months later. Second follow-up will be collected 19 months after baseline. For C2, data was collected at baseline (August 2017), and first and second follow-up will be collected similarly to that of C2 seven and 19 months respectively after baseline. Process evaluations based on focus groups, interviews and observation will be conducted twice (first completed spring 2017).
The COMPLETE trial is a large study that can provide useful knowledge about what interventions might effectively improve completion of upper secondary school. Its thorough process evaluation will provide critical information about barriers and points of improvement for optimizing intervention implementation. Findings can guide school development in the perspective of improving psychosocial learning environments and subsequent completion of upper secondary schooling.
The trial was retrospectively registered in the ClinicalTrials.gov register on December 22.2017: NCT03382080 .
Summary
Background
In developed countries, hepatitis E is a porcine zoonosis caused by hepatitis E virus (HEV) genotype 3. In developing countries, hepatitis E is mainly caused by genotype 1, and ...causes increased mortality in patients with pre‐existing chronic liver disease (CLD).
Aim
To determine the role of HEV in patients with decompensated CLD.
Methods
Prospective HEV testing of 343 patients with decompensated CLD at three UK centres and Toulouse France, with follow‐up for 6 months or death. IgG seroprevalence was compared with 911 controls.
Results
11/343 patients (3.2%) had acute hepatitis E infection, and three died. There were no differences in mortality (27% vs. 26%, OR 1.1, 95% CI 0.28–4.1), age (P = 0.9), bilirubin (P = 0.5), alanine aminotransferase (P = 0.06) albumin (P = 0.5) or international normalised ratio (P = 0.6) in patients with and without hepatitis E infection. Five cases were polymerase chain reaction (PCR) positive (genotype 3). Hepatitis E was more common in Toulouse (7.9%) compared to the UK cohort (1.2%, P = 0.003). HEV IgG seroprevalence was higher in Toulouse (OR 17, 95% CI 9.2–30) and Truro (OR 2.5, 95% CI 1.4–4.6) than in Glasgow, but lower in cases, compared to controls (OR 0.59, 95% CI 0.41–0.86).
Conclusions
Hepatitis E occurs in a minority of patients with decompensated chronic liver disease. The mortality is no different to the mortality in patients without hepatitis E infection. The diagnosis can only be established by a combination of serology and PCR, the yield and utility of which vary by geographical location.
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