Over the past century, agricultural landscapes worldwide have increasingly been managed for the primary purpose of producing food, while other diverse ecosystem services potentially available from ...these landscapes have often been undervalued and diminished. The incorporation of relatively small amounts of perennial vegetation in strategic locations within agricultural landscapes dominated by annual crops—or perennialization—creates an opportunity for enhancing the provision of a wide range of goods and services to society, such as water purification, hydrologic regulation, pollination services, control of pest and pathogen populations, diverse food and fuel products, and greater resilience to climate change and extreme disturbances, while at the same time improving the sustainability of food production. This paper synthesizes the current scientific theory and evidence for the role of perennial plants in balancing conservation with agricultural production, focusing on the Midwestern USA as a model system, while also drawing comparisons with other climatically diverse regions of the world. Particular emphasis is given to identifying promising opportunities for advancement and critical gaps in our knowledge related to purposefully integrating perennial vegetation into agroecosystems as a management tool for maximizing multiple benefits to society.
Thermophotovoltaic efficiency of 40 LaPotin, Alina; Schulte, Kevin L; Steiner, Myles A ...
Nature (London),
04/2022, Letnik:
604, Številka:
7905
Journal Article
Recenzirano
Odprti dostop
Thermophotovoltaics (TPVs) convert predominantly infrared wavelength light to electricity via the photovoltaic effect, and can enable approaches to energy storage
and conversion
that use higher ...temperature heat sources than the turbines that are ubiquitous in electricity production today. Since the first demonstration of 29% efficient TPVs (Fig. 1a) using an integrated back surface reflector and a tungsten emitter at 2,000 °C (ref.
), TPV fabrication and performance have improved
. However, despite predictions that TPV efficiencies can exceed 50% (refs.
), the demonstrated efficiencies are still only as high as 32%, albeit at much lower temperatures below 1,300 °C (refs.
). Here we report the fabrication and measurement of TPV cells with efficiencies of more than 40% and experimentally demonstrate the efficiency of high-bandgap tandem TPV cells. The TPV cells are two-junction devices comprising III-V materials with bandgaps between 1.0 and 1.4 eV that are optimized for emitter temperatures of 1,900-2,400 °C. The cells exploit the concept of band-edge spectral filtering to obtain high efficiency, using highly reflective back surface reflectors to reject unusable sub-bandgap radiation back to the emitter. A 1.4/1.2 eV device reached a maximum efficiency of (41.1 ± 1)% operating at a power density of 2.39 W cm
and an emitter temperature of 2,400 °C. A 1.2/1.0 eV device reached a maximum efficiency of (39.3 ± 1)% operating at a power density of 1.8 W cm
and an emitter temperature of 2,127 °C. These cells can be integrated into a TPV system for thermal energy grid storage to enable dispatchable renewable energy. This creates a pathway for thermal energy grid storage to reach sufficiently high efficiency and sufficiently low cost to enable decarbonization of the electricity grid.
The geochemical analysis of natural archives can improve our knowledge of past mining activities and their environmental imprint. The sedimentary records from the Hasli-Aare floodplain (Bernese Alps) ...over the last 2500 years were analysed for metals. Evidence of past mining contamination was obtained from the XRF analyses of iron, copper, zinc and lead. These results were analytically and statistically processed to produce a metal content index. Positive metal anomalies indicate four major pulses of contamination coinciding with the end of the Iron Age, from the end of the Roman Period to the Early Medieval Period, the Late Medieval Period, and the Modern Period. These pulses show good agreement with local historical sources of mining in the Hasli-Aare catchment, dating back to the beginning of the 15th century. Furthermore, they are in phase with anthropogenic pollution trends inferred from glacier ice cores, lake sediments and peat bogs across the Western Alps, most notably during the Roman, Late Medieval and Modern Periods. However, close comparison between these records can show some differences, suggesting local variations in mining activities and/or a lag in metal transfer. The reconstructed periods of anthropogenic metal pollution are located in their political, economic and social contexts and compared with the climate periods of central Europe.
Display omitted
•Anthropogenic metal contamination in the Bernese Alps dates back to the Iron Age.•Sediments exhibited the most significant metal peak anomalies in the last 500 yrs.•Shifts in metal trends correspond with socioeconomic changes in central Europe.•Similar anthropogenic pollution trends are observed across the Alpine region.•Other archives and knowledge of ancient mining validated sediment metal trends.
RATIONALE:A hallmark of chronic inflammatory disorders is persistence of proinflammatory macrophages in diseased tissues. In atherosclerosis, this is associated with dyslipidemia and oxidative ...stress, but mechanisms linking these phenomena to macrophage activation remain incompletely understood.
OBJECTIVE:To investigate mechanisms linking dyslipidemia, oxidative stress, and macrophage activation through modulation of immunometabolism and to explore therapeutic potential targeting specific metabolic pathways.
METHODS AND RESULTS:Using a combination of biochemical, immunologic, and ex vivo cell metabolic studies, we report that CD36 mediates a mitochondrial metabolic switch from oxidative phosphorylation to superoxide production in response to its ligand, oxidized LDL (low-density lipoprotein). Mitochondrial-specific inhibition of superoxide inhibited oxidized LDL-induced NF-κB (nuclear factor-κB) activation and inflammatory cytokine generation. RNA sequencing, flow cytometry, 3H-labeled palmitic acid uptake, lipidomic analysis, confocal and electron microscopy imaging, and functional energetics revealed that oxidized LDL upregulated effectors of long-chain fatty acid uptake and mitochondrial import, while downregulating fatty acid oxidation and inhibiting ATP5A (ATP synthase F1 subunit alpha)—an electron transport chain component. The combined effect is long-chain fatty acid accumulation, alteration of mitochondrial structure and function, repurposing of the electron transport chain to superoxide production, and NF-κB activation. Apoe null mice challenged with high-fat diet showed similar metabolic changes in circulating Ly6C monocytes and peritoneal macrophages, along with increased CD36 expression. Moreover, mitochondrial reactive oxygen species were positively correlated with CD36 expression in aortic lesional macrophages.
CONCLUSIONS:These findings reveal that oxidized LDL/CD36 signaling in macrophages links dysregulated fatty acid metabolism to oxidative stress from the mitochondria, which drives chronic inflammation. Thus, targeting to CD36 and its downstream effectors may serve as potential new strategies against chronic inflammatory diseases such as atherosclerosis.
Introduction/purpose
In adult scoliosis surgery (AS) delineation of risk factors contributing to failure is important to improve patient care. Treatment goals include deformity correction resulting ...in a balanced spine and horizontal lowest instrumented vertebra (LIV) in fusions not ending at S1. Therefore, the study objectives were to determine predictors for deformity correction, complications, revision surgery, and outcomes as well as to determine predictors of postoperative evolution of the LIV-take-off angle (LIV-TO) and symptomatic adjacent segment disease (ASD).
Methods
The authors performed a retrospective analysis of 448 patients who had AS surgery. Patients’ age averaged 51 years, BMI 26, and follow-up of 40 months. According to the SRS adult scoliosis classification, 51 % of patients had major lumbar curves, 24 % each with single thoracic or double major curves. 54 % of patients had stable vertebra at L5 and 34 % of patients had fusion to S1. The mean number of posterior fusion levels was eight and implant density 73 %. Among standard radiographic measures of deformity the LIV-TO was assessed on neutral and bending/traction-films (bLIV-TO). Clinical outcomes were assessed in 145 patients with degenerative-type AS using validated measures (ODI, COMI and SF-36). Prediction analysis was conducted with stepwise multiple regression analyses.
Results
Preoperative thoracic curve (TC) was 53° and 33° at follow-up. Preoperative lumbar curve (LC) was 43° and 24° at follow-up. Curve flexibility was low (TC 34 %/LC 38 %). TC-correction (38 %) was predicted by preoperative TC (
r
= 0.9) and TC-flexibility (
r
= 0.8). LC-correction (50 %) was predicted by preoperative LC (
r
= 0.8), LC-flexibility (
r
= 0.8) and screw density (
r
= 0.7). Preoperative LIV-TO was 18.2° and at follow-up 9.4° (
p
< 0.01). 20 % of patients had a non-union (18 % at L5-S1). The risk for non-union at L5-S1 increased with age (
p
= 0.04), low screw density (
p
= 0.03), and postoperative sagittal imbalance (T9-tilt (
p
= 0.01), C7-SVA (
p
= 0.01), LL (
p
= 0.01) and PI-LL mismatch (
p
= 0.01). 32 % of patients had revision surgery. Risk for revision was increased in fusions to S1 (
p
< 0.01), increased BMI (
p
< 0.01), sagittal imbalance (C7-SVA,
p
< 0.01), age (
p
= 0.02), and disc wedging distal to the LIV (
p
< 0.01). To a varying extent, clinical outcomes negatively correlated (
p
< 0.05) with revision, ASD, perioperative complications, age, low postoperative TC- and LC-correction, and sagittal and coronal imbalance at follow-up (C7-SVA, PT, and C7-CSVL). 59 patients had ASD, which correlated with preoperative and postoperative sagittal and coronal parameters of deformity. In a multivariate model, preoperative bLIV-TO (
p
< 0.01) and preoperative LIV-TO (
p
< 0.01) demonstrated the highest predictive strength for follow-up LIV-TO.
Conclusion
In the current study, the magnitude of deformity correction in the sagittal and coronal planes was shown to have significant impact on radiographic and clinical outcomes as well as revision rates. Findings indicate that risks for complications might be reduced by restoration of sagittal balance, appropriate deformity correction and advanced lumbosacral fixation. The use of preoperative LIV-TO and LIV-TO on bending/traction-films were shown to be useful for surgical planning, selection of the LIV and prediction of follow-up-TO, respectively. Parameters of sagittal balance rather than coronal deformity predicted ASD.
Public agencies and private enterprises increasingly desire to achieve ecosystem service outcomes in agricultural systems, but are limited by perceived conflicts between economic and ecosystem ...service goals and a lack of tools enabling effective operational management. Here we use Iowa-an agriculturally homogeneous state representative of the Maize Belt-to demonstrate an economic rationale for cropland diversification at the subfield scale. We used a novel computational framework that integrates disparate but publicly available data to map ∼3.3 million unique potential management polygons (9.3 Mha) and reveal subfield opportunities to increase overall field profitability. We analyzed subfield profitability for maize soybean fields during 2010-2013-four of the most profitable years in recent history-and projected results for 2015. While cropland operating at a loss of US$ 250 ha−1 or more was negligible between 2010 and 2013 at 18 000-190 000 ha (<2% of row-crop land), the extent of highly unprofitable land increased to 2.5 Mha, or 27% of row-crop land, in the 2015 projection. Aggregation of these areas to the township level revealed 'hotspots' for potential management change in Western, Central, and Northeast Iowa. In these least profitable areas, incorporating conservation management that breaks even (e.g., planting low-input perennials), into low-yielding portions of fields could increase overall cropland profitability by 80%. This approach is applicable to the broader region and differs substantially from the status quo of 'top-down' land management for conservation by harnessing private interest to align profitability with the production of ecosystem services.
Parental care is a limited resource which in many species is acquired by the offspring through begging behaviours and often causes competition between siblings. The Neotropical poison frog Ranitomeya ...variabilis provides a very specific form of parental care: because its tadpoles are cannibalistic males usually separate them from their siblings after hatching by transporting them singly to small water bodies. However, in some cases parents do not transport their tadpoles but let them all hatch into the same pool. Here, we investigate if abandoned tadpoles of R. variabilis actively seek parental care in form of transportation. We conducted experiments where tadpoles of the same clutch were presented with con‐ and heterospecific frogs, and both moving and non‐moving frog models. Our results revealed that abandoned tadpoles actively approached all frogs and sometimes even climbed onto their backs. We suggest that this tadpole behaviour may function to allow tadpoles to escape sibling competition and cannibalism. Being the first (and possibly the only one) to leave the shared pool should give a tadpole a high survival advantage over its brood‐mates. We further found that tadpoles did not approach artificial models, suggesting that these where either not natural enough or that tadpoles do not recognize frogs by visual or tactile cues but might use chemical or multiple stimuli. The latter is also the case in related egg‐feeding species where tadpoles beg for food. We therefore discuss our results in relation to potential begging behaviours, as well as fixed action patterns and parent–offspring conflict, being potential questions opening up for future examinations regarding our findings.
Poison frog tadpoles of the species Ranitomeya variabilis, unless separately transported elsewhere by their parents, hatch together with their cannibalistic siblings into small plant pools. Our behavioural tests revealed that such tadpoles were highly attracted not only to conspecific but all frogs entering their pools, followed them and tried to climb onto their backs, probably in order to escape their siblings. Moved and motionless frog models, however, did not trigger the same behaviour, assuming that they did not emit the right cues to attract tadpoles.
In patients presenting with low back pain (LBP), once specific causes are excluded (fracture, infection, inflammatory arthritis, cancer, cauda equina and radiculopathy) many clinicians pose a ...diagnosis of non-specific LBP. Accordingly, current management of non-specific LBP is generic. There is a need for a classification of non-specific LBP that is both data- and evidence-based assessing multi-dimensional pain-related factors in a large sample size. The “PRedictive Evidence Driven Intelligent Classification Tool for Low Back Pain” (PREDICT-LBP) project is a prospective cross-sectional study which will compare 300 women and men with non-specific LBP (aged 18–55 years) with 100 matched referents without a history of LBP. Participants will be recruited from the general public and local medical facilities. Data will be collected on spinal tissue (intervertebral disc composition and morphology, vertebral fat fraction and paraspinal muscle size and composition via magnetic resonance imaging MRI), central nervous system adaptation (pain thresholds, temporal summation of pain, brain resting state functional connectivity, structural connectivity and regional volumes via MRI), psychosocial factors (e.g. depression, anxiety) and other musculoskeletal pain symptoms. Dimensionality reduction, cluster validation and fuzzy c-means clustering methods, classification models, and relevant sensitivity analyses, will classify non-specific LBP patients into sub-groups. This project represents a first personalised diagnostic approach to non-specific LBP, with potential for widespread uptake in clinical practice. This project will provide evidence to support clinical trials assessing specific treatments approaches for potential subgroups of patients with non-specific LBP. The classification tool may lead to better patient outcomes and reduction in economic costs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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