Ponderosa pine (Pinus ponderosa) forests of the southwestern United States are a mosaic of stands where undisturbed forests are carbon sinks, and stands recovering from wildfires may be sources of ...carbon to the atmosphere for decades after the fire. However, the relative magnitude of these sinks and sources has never been directly measured in this region, limiting our understanding of the role of fire in regional and US carbon budgets. We used the eddy covariance technique to measure the CO2 exchange of two forest sites, one burned by fire in 1996, and an unburned forest. The fire was a high‐intensity stand‐replacing burn that killed all trees. Ten years after the fire, the burned site was still a source of CO2 to the atmosphere 109±6 (SEM) g C m−2 yr−1, whereas the unburned site was a sink (−164±23 g C m−2 yr−1). The fire reduced total carbon storage and shifted ecosystem carbon allocation from the forest floor and living biomass to necromass. Annual ecosystem respiration was lower at the burned site (480±5 g C m−2 yr−1) than at the unburned site (710±54 g C m−2 yr−1), but the difference in gross primary production was even larger (372±13 g C m−2 yr−1 at the burned site and 858±37 g C m−2 yr−1at the unburned site). Water availability controlled carbon flux in the warm season at both sites, and the burned site was a source of carbon in all months, even during the summer, when wet and warm conditions favored respiration more than photosynthesis. Our study shows that carbon losses following stand‐replacing fires in ponderosa pine forests can persist for decades due to slow recovery of the gross primary production. Because fire exclusion is becoming increasingly difficult in dry western forests, a large US forest carbon sink could shift to a decadal‐scale carbon source.
Background and purpose
Mutations in the glucocerebrosidase (GBA) gene are known to be a risk factor for Parkinson's disease (PD). Data on clinicopathological correlation are limited. The purpose of ...this study was to determine the clinicopathological findings that might distinguish PD cases with and without mutations in the GBA gene.
Methods
Data from the Arizona Study of Aging and Neurodegenerative Disorders were used to identify autopsied PD cases that did or did not have a GBA gene mutation. Clinical and neuropathological data were compared.
Results
Twelve PD cases had a GBA mutation and 102 did not. The GBA mutation cases died younger (76 vs. 81 years of age) but there was no difference in disease duration or clinical examination findings. No neuropathological differences were found in total or regional semi‐quantitative scores for Lewy‐type synucleinopathy, senile plaques, neurofibrillary tangles, white matter rarefaction or cerebral amyloid angiopathy scores.
Conclusions
In longitudinally assessed, autopsied PD cases, those with GBA mutations had a younger age at death but there was no evidence for clinical or neuropathological differences compared to cases without GBA mutations. Due to the small GBA group size, small differences cannot be excluded.
Coherent elastic neutrino-nucleus scattering (CEνNS) offers a valuable approach in searching for physics beyond the standard model. The
Ricochet
experiment aims to perform a precision measurement of ...the CEνNS spectrum at the Institut Laue–Langevin nuclear reactor with cryogenic solid-state detectors. The experiment plans to employ an array of cryogenic thermal detectors, each with a mass of around 30 g and an energy threshold of below 100 eV. The array includes nine detectors read out by transition-edge sensors (TES). These TES-based detectors will also serve as demonstrators for future neutrino experiments with thousands of detectors. In this article, we present an update on the characterization and modeling of a prototype TES detector.
Properties of Low TC AlMn TES Wang, G.; Bratrud, G.; Chang, C. L. ...
Journal of low temperature physics,
2024/5, Letnik:
215, Številka:
3-4
Journal Article
Recenzirano
Low T
C
AlMn transition-edge sensors (TESs) have been developed as sensitive thermometers for the Q-Array, which will use superconducting targets to measure the coherent elastic neutrino nucleus ...scattering spectrum in the RICOCHET experiment. The TESs are made of manganese-doped aluminum with a titanium and gold antioxidation layer. A prototype TES thermometer consists of two TESs in parallel, an input gold pad in metallic contact with the TESs and an output gold pad and gold thermal link meanders, which are each designed to control the flow of heat through the TESs. We have fabricated and measured low T
C
AlMn TES chips with or without thermal flow control structures. We present T
C
measurements of the TESs after the initial fabrication and further T
C
tuning by re-heating and summarize the thermal property studies of the prototype TES thermometer by measuring I-V curves and complex impedance.
Climate change and increased fire are eroding the resilience of boreal forests. This is problematic because boreal vegetation and the cold soils underneath store approximately 30 % of all terrestrial ...carbon. Society urgently needs projections of where, when, and why boreal forests are likely to change. Permafrost (i.e., subsurface material that remains frozen for at least 2 consecutive years) and the thick soil-surface organic layers (SOLs) that insulate permafrost are important controls of boreal forest dynamics and carbon cycling. However, both are rarely included in process-based vegetation models used to simulate future ecosystem trajectories. To address this challenge, we developed a computationally efficient permafrost and SOL module named the Permafrost and Organic LayEr module for Forest Models (POLE-FM) that operates at fine spatial (1 ha) and temporal (daily) resolutions. The module mechanistically simulates daily changes in depth to permafrost, annual SOL accumulation, and their complex effects on boreal forest structure and functions. We coupled the module to an established forest landscape model, iLand, and benchmarked the model in interior Alaska at spatial scales of stands (1 ha) to landscapes (61 000 ha) and over temporal scales of days to centuries. The coupled model generated intra- and inter-annual patterns of snow accumulation and active layer depth (portion of soil column that thaws throughout the year) generally consistent with independent observations in 17 instrumented forest stands. The model also represented the distribution of near-surface permafrost presence in a topographically complex landscape. We simulated 39.3 % of forested area in the landscape as underlain by permafrost, compared to the estimated 33.4 % from the benchmarking product. We further determined that the model could accurately simulate moss biomass, SOL accumulation, fire activity, tree species composition, and stand structure at the landscape scale. Modular and flexible representations of key biophysical processes that underpin 21st-century ecological change are an essential next step in vegetation simulation to reduce uncertainty in future projections and to support innovative environmental decision-making. We show that coupling a new permafrost and SOL module to an existing forest landscape model increases the model's utility for projecting forest futures at high latitudes. Process-based models that represent relevant dynamics will catalyze opportunities to address previously intractable questions about boreal forest resilience, biogeochemical cycling, and feedbacks to regional and global climate.
The annual area burned due to wildfires in the western United States (WUS) increased by
more than 300 % between 1984 and 2020. However, accounting for the nonlinear, spatially heterogeneous ...interactions between climate, vegetation, and human predictors driving the trends in fire frequency and sizes at different spatial scales remains a challenging problem for statistical fire models. Here we introduce a novel stochastic machine learning (SML) framework, SMLFire1.0, to model observed fire frequencies and sizes in 12 km × 12 km grid cells across the WUS. This framework is implemented using mixture density networks trained on a wide suite of input predictors. The modeled WUS fire frequency matches observations at both monthly (r=0.94) and annual (r=0.85) timescales, as do the monthly (r=0.90) and annual (r=0.88) area burned. Moreover, the modeled annual time series of both fire variables exhibit strong correlations (r≥0.6) with observations in 16 out of 18 ecoregions. Our ML model captures the interannual variability and the distinct multidecade increases in annual area burned for both forested and non-forested ecoregions. Evaluating predictor importance with Shapley additive explanations, we find that fire-month vapor pressure deficit (VPD) is the dominant driver of fire frequencies and sizes across the WUS, followed by 1000 h dead fuel moisture (FM1000), total monthly precipitation (Prec), mean daily maximum temperature (Tmax), and fraction of grassland cover in a grid cell. Our findings serve as a promising use case of ML techniques for wildfire prediction in particular and extreme event modeling more broadly. They also highlight the power of ML-driven parameterizations for potential implementation in fire modules of dynamic global vegetation models (DGVMs) and earth system models (ESMs).
Recognizing Facial Cues Parr, Lisa A; Winslow, James T; Hopkins, William D ...
Journal of comparative psychology (1983),
03/2000, Letnik:
114, Številka:
1
Journal Article
Recenzirano
Faces are one of the most salient classes of stimuli
involved in social communication. Three experiments compared
face-recognition abilities in chimpanzees (
Pan troglodytes
) and
rhesus monkeys (
...Macaca mulatta
). In the face-matching task, the
chimpanzees matched identical photographs of conspecifics' faces on
Trial 1, and the rhesus monkeys did the same after 4 generalization
trials. In the individual-recognition task, the chimpanzees matched
2 different photographs of the same individual after 2 trials, and
the rhesus monkeys generalized in fewer than 6 trials. The
feature-masking task showed that the eyes were the most important
cue for individual recognition. Thus, chimpanzees and rhesus monkeys
are able to use facial cues to discriminate unfamiliar conspecifics.
Although the rhesus monkeys required many trials to learn the tasks,
this is not evidence that faces are not as important social stimuli
for them as for the chimpanzees.
Given the choice of standard, cluster, and rush build-up for aeroallergen immunotherapy, standard-build immunotherapy has generally been preferred because of a perceived high rate of systemic ...reactions (SRs) associated with cluster and rush immunotherapy.
To characterize the incidence of SRs during standard, cluster, and rush build-up immunotherapy in an allergy practice during a 5-year period.
A retrospective review was conducted among patients receiving standard-build, 8- to 10-step cluster, or 2-day rush immunotherapy from January 1, 2010, through December 31, 2014, at Family Allergy & Asthma clinics in Louisville, Kentucky. Investigators excluded reactions that occurred during skin prick testing, venom immunotherapy, and not-true SRs, and identified the build-up method, age, sex, date of reaction, vial concentration, and presence of asthma. Per-shot and per-patient incidence of SRs was computed from these data.
During our review period, 2,549,643 injections were administered to 11,982 patients. Per-shot incidence of SR was 0.01%, 0.06%, and 0.33% for standard, cluster, and rush immunotherapy, respectively; per-patient incidence of SR was 2.84%, 2.52%, and 11.86% for standard, cluster, and rush immunotherapy, respectively. A total of 42% of SRs were grade 1, 43% were grade 2, 12% were grade 3, and 3% were grade 4. No fatalities were reported. A total of 70% of total SRs, 75% of cluster SR, and 55% of rush SR occurred in females, with an emergent peak in SR from May to October.
Compared with previously published rates, we observed a decrease in the incidence of SR for standard, cluster, and rush immunotherapy, with peak seasonality from May to October and a female predominance.
The Lambeth Conventions are guidelines intended to be of practical value in the investigation of arrhythmias induced by ischaemia, infarction, and reperfusion. They cover the design and execution of ...experiments and the definition, classification, quantification, and analysis of arrhythmias. Investigators are encouraged to adopt the conventions in the hope that this will improve uniformity and interlaboratory comparisons.
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