Utilizing biomass energy for improving summer squash greenhouse productivity during the winter season

The objective of this present research is to use agricultural residues as a source of energy for heating greenhouses during winter seasons and sequestrating soil carbon dioxide through adding biochar to the soil media. To fulfill the objective of the research work, summer squash was transplanted in a constructed greenhouse and heated using an attached biomass-burning system. The performance of the attached biomass-burning system was experimentally studied under different agricultural residues (corn stalks, cotton stalks and okra stalks), heating fluids (water and oil) and air fan operating periods (10, 15 and 20 min/h). Results indicated that the biomass-burning system allowed increasing temperature and relative humidity inside the greenhouse up to 27.2 and 80 %, respectively. The maximum biomass-burning system efficiency of 81 % was achieved with the use of okra stalks as a source of energy and oil as a heating fluid side by side with adjusting the suction fan operating period at 15 min/h. Adding bio-charcoal to the soil media, enhanced the soil carbon, resulting in a total fresh yield of 3.7 and 2.9 kg/pot with a total number of leaves per plant of 55 and 47 leaves under conditions of with and without charcoal addition, respectively.     

气候变暖背景下广东冬种生产季气候资源和气象灾害的时空变化

运用趋势分析法研究了气候变暖前(1961—1996年)后(1997—2015年)广东冬种生产季气候资源和气象灾害的一般变化特征;引入百分位法确定了冬种主产区发生极端寒害和干旱的阈值,重点分析了气候变暖以来的极端灾害特征.结果表明: 与1961—1996年相比,1997—2015年区域内冬种生产季热量显著增加,冬种主产区湛江、茂名、惠州、韶关、梅州和广州等处在平均气温≥15 ℃、积温≥2200 ℃·d的高值区;降水略增加,湛江、茂名、惠州、广州和梅州大部地区处在降水量250～350 mm的区域.区域内冬种生产季寒害呈减轻趋势,湛江、茂名、广州和惠州大部均处于积寒<2 ℃·d的区域,韶关和梅州大部处在积寒8～16 ℃·d的区域;干旱日数呈减少趋势,湛江、茂名、惠州、广州和梅州大部处在干旱日数≥50 d的区域,韶关处在干旱日数<50 d的区域.从灾害典型个例分析可知,冬种主产区极端寒害和干旱的风险不容忽视,湛江、茂名、惠州和梅州发生极端寒害的风险较高,韶关和广州次之;湛江、茂名发生极端干旱的风险较高,惠州和广州次之,韶关和梅州较小.1997—2015年间,冬种生产季热量显著增加,寒害、干旱呈减轻趋势,但冬种主产区极端灾害频发、风险较高,建议在实际生产中紧密结合冬种生产季气候资源和气象灾害的发生规律发展冬种.     

冬季水分管理方式对稻田CH4排放量的影响

在西南农业大学和华南农业大学农场的田间试验表明 ,长期淹水是我国西南地区冬灌田水稻生长期CH4排放通量高于一般水田的主要原因 .土壤淹水前连续干燥的时间越长 ,水稻生长期CH4排放通量越低 ,但这种作用仅能维持一季水稻生长期 .冬灌田冬季排干 ,种植冬小麦 ,次年水稻生长期CH4平均排放通量可减少 63～ 72 % .如果我国西南地区冬灌田的水利设施能够得到有效改善 ,改冬灌为冬排 ,一年一季水稻为一水一旱 ,将可提高该类土壤生产力和大大减少我国稻田CH4排放总量 .     

Significance of sinking particles in the distribution of motile Aeromonas during the winter season.

The role of sinking particles in the distribution of motile Aeromonas species was studied during the winter season. Various environmental parameters and microbial populations were investigated to elucidate the relationship with motile aeromonads. Motile Aeromonas species were enumerated by most probable number technique with alkaline peptone water as the enrichment medium and modified pril-xylose ampicillin agar as the plating medium. Aeromonas species were isolated in a water column in any one of the two procedures but sediment and plankton samples exhibited an irregular isolation pattern for these organisms. Aeoromonas species were continuously isolated in sinking particles with the highest counts during January. Of the 206 isolates identified, three known motile Aeromonas species were observed of which A. caviae accounted for 51.4% of the total. Toxin characterization showed that 20% of the strains produced haemolysin as well as cytotoxin, and A. hydrophila was highly toxigenic. Statistical analyses revealed that nutrients govern the distribution of Aeromonas. It may be that riverine discharge influences the distribution of motile aeromonads in this environment.     

Habitat of the corn leafhopper (Hemiptera: Cicadellidae) during the dry (winter) season in Mexico

Although the corn leafhopper Dalbulus maidis (DeLong and Wolcott) is the most important vector of maize pathogens in Latin America, little is known about how and where it overwinters (passes the dry season), particularly in Mexico. The objectives of this study were (1) to monitor the abundance of D. maidis adults throughout the dry season in maize and maize-free habitats and (2) to determine where and how D. maidis adults, exposed or nonexposed to the maize pathogen Spiroplasma kunkelii Whitcomb, overwinter in a maize-free habitat. Work for the first objective was done during the two consecutive dry seasons of 1999-2000 and 2000-2001; the second objective was done during the dry seasons of 2003-2004 and 2005-2006. During the dry winter seasons, D. maidis was prevalent as long as maize was present in irrigated areas. The leafhopper was found in 52 of the 58 irrigated maize fields sampled in Mexico at the end of the dry seasons of 1999-2000 and 2000-2001. However, leafhopper adults were not found in nonirrigated maize-free habitats at high elevation during the dry winter season (February, March, and April), although leafhopper adults were prevalent on perennial wild grasses in January after maize harvest. Additional experiments revealed, however, that corn leafhopper adults, although few in number, survived the entire dry season in these nonirrigated maize-free fields. Also, no detectable difference in survival existed between leafhoppers exposed and those not exposed to S. kunkelli during the two dry seasons in the maize-free habitat.     

Enhanced winter soil frost reduces methane emission during the subsequent growing season in a boreal peatland

Winter climate change may result in reduced snow cover and could, consequently, alter the soil frost regime and biogeochemical processes underlying the exchange of methane (CH₄) in boreal peatlands. In this study, we investigated the short‐term (1–3 years) vs. long‐term (11 years) effects of intensified winter soil frost (induced by experimental snow exclusion) on CH₄ exchange during the following growing season in a boreal peatland. In the first 3 years (2004–2006), lower CH₄ emissions in the treatment plots relative to the control coincided with delayed soil temperature increase in the treatment plots at the beginning of the growing season (May). After 11 treatment years (in 2014), CH₄ emissions were lower in the treatment plots relative to the control over the entire growing season, resulting in a reduction in total growing season CH₄ emission by 27%. From May to July 2014, reduced sedge leaf area coincided with lower CH₄ emissions in the treatment plots compared to the control. From July to August, lower dissolved organic carbon concentrations in the pore water of the treatment plots explained 72% of the differences in CH₄ emission between control and treatment. In addition, greater Sphagnum moss growth in the treatment plots resulted in a larger distance between the moss surface and the water table (i.e., increasing the oxic layer) which may have enhanced the CH₄ oxidation potential in the treatment plots relative to the control in 2014. The differences in vegetation might also explain the lower temperature sensitivity of CH₄ emission observed in the treatment plots relative to the control. Overall, this study suggests that greater soil frost, associated with future winter climate change, might substantially reduce the growing season CH₄ emission in boreal peatlands through altering vegetation dynamics and subsequently causing vegetation‐mediated effects on CH₄ exchange.     

Placebo Trends across the Border: US versus Canada

Background

Physicians around the world report to using placebos in a variety of situations and with varying degrees of frequency. Inconsistent methodologies, however, complicate interpretation and prevent direct comparisons across studies. While US- and Canada-based physicians share similar professional standards, Canada harbours a less-litigious universal healthcare model with no formal placebo-related policy—factors that may impact how physicians view and use placebos.

Methods

To compare American and Canadian data, we circulated an online survey to academic physicians practicing in Canada, collected anonymous responses, and extracted those of internists and rheumatologists for comparison to US data obtained through parallel methodologies.

Results

Whereas our data show overall concordance across the border—from definitions to ethical limitations and therapeutic potential—differences between American- and Canadian-based placebo practices merit acknowledgement. For example, compared to 45%-80% among US-based respondents, only 23±7% of Canada-based respondents reported using placebos in clinical practice. However, 79±7% of Canada-respondents—a figure comparable to US data—professed to prescribing at least one form of treatment without proven or expected efficacy. Placebo interventions including unwarranted vitamins and herbal supplements (impure placebos) as well as sugar pills and saline injections (pure placebos) appear more common in Canada, where more doctors described placebos as “placebos” (rather than “medications”) and used them as a “diagnostic” tool (rather than a means of placating patient demands for treatment).

Interpretation

Cross-border variation in the use of clinical placebos appears minor despite substantial differences in health care delivery system, malpractice climate, and placebo-related policy. The prevalence of impure placebos in both Canadian and US clinics raises ethical and practical questions currently unaddressed by policy and warranting investigation.     

Human plasma inflammatory response during 5 days of exercise training in the heat

The aim of the present investigation was to examine the response of 80 plasma inflammatory analytes during five days of exercise in a hot (38 °C, 40% relative humidity) environment. 15 male participants (25±4yrs, 54±6 ml kg⁻¹ min⁻¹ VO₂ max), with no heat exposure within the previous 3 weeks, were asked to cycle in a hot environment at 70% of their VO₂ max workload until their terminal temperature was obtained, for 5 consecutive days. Terminal temperature was determined as the core temperature at volitional exhaustion or a core temperature of 39.5 °C, whichever came first. Blood samples were collected pre- and post-exercise on day 1 and day 5. Pre-trial urine specific gravity and body weight was not different on day 1 and day 5. Exercise time and heart rate at terminal temperature did not change during the five days. Of the 52 plasma analytes that increased in concentration on day 1, only 30 demonstrated increased concentrations at terminal temperature on day 5. Resting concentrations of 18, both pro- (IL-12p40, IL-15) and anti-inflammatory (IL-1ra, IL-10, IL-13) analytes were elevated on day 5 compared to day 1. We conclude that individuals completing consecutive days of exercise in the heat, but not definitively attaining heat acclimation, have increased resting levels of many inflammatory analytes associated with heat illness, but also demonstrate a reduced inflammatory response to a subsequent bout of exercise in the heat.     

Developing of a model to predict lying behavior of dairy cows on silvopastoral system during the winter season

International Journal of Biometeorology - Lying behavior is an important indicator of the cows’ welfare and health. In this study, we evaluate the effect of the physical environment on dairy...     

Carbon limitation of soil respiration under winter snowpacks: potential feedbacks between growing season and winter carbon fluxes

A reduction in the length of the snow‐covered season in response to a warming of high‐latitude and high‐elevation ecosystems may increase soil carbon availability both through increased litter fall following longer growing seasons and by allowing early winter soil frosts that lyse plant and microbial cells. To evaluate how an increase in labile carbon during winter may affect ecosystem carbon balance we investigated the relationship between carbon availability and winter CO₂ fluxes at several locations in the Colorado Rockies. Landscape‐scale surveys of winter CO₂ fluxes from sites with different soil carbon content indicated that winter CO₂ fluxes were positively related to carbon availability and experimental additions of glucose to soil confirmed that CO₂ fluxes from snow‐covered soil at temperatures between 0 and ?3°C were carbon limited. Glucose added to snow‐covered soil increased CO₂ fluxes by 52–160% relative to control sites within 24 h and remained 62–70% higher after 30 days. Concurrently a shift in the δ¹³C values of emitted CO₂ toward the glucose value indicated preferential utilization of the added carbon confirming the presence of active heterotrophic respiration in soils at temperatures below 0°C. The sensitivity of these winter fluxes to substrate availability, coupled with predicted changes in winter snow cover, suggests that feedbacks between growing season carbon uptake and winter heterotrophic activity may have unforeseen consequences for carbon and nutrient cycling in northern forests. For example, published winter CO₂ fluxes indicate that on average 50% of growing season carbon uptake currently is respired during the winter; changes in winter CO₂ flux in response to climate change have the potential to reduce substantially the net carbon sink in these ecosystems.     

Avian diversity and function across the world's most populous cities

Understanding the composition of urban wildlife communities is crucial to promote biodiversity, ecosystem function and links between nature and people. Using crowdsourced data from over five million eBird checklists, we examined the influence of urban characteristics on avian richness and function at 8443 sites within and across 137 global cities. Under half of the species from regional pools were recorded in cities, and we found a significant phylogenetic signal for urban tolerance. Site-level avian richness was positively influenced by the extent of open forest, cultivation and wetlands and avian functional diversity by wetlands. Functional diversity co-declined with richness, but groups including granivores and aquatic birds occurred even at species-poor sites. Cities in arid areas held a higher percentage of regional species richness. Our results indicate commonalities in the influence of habitat on richness and function, as well as lower niche availability, and phylogenetic diversity across the world's cities.     

Thermal biology, torpor, and activity in free-living mulgaras in arid zone Australia during the winter reproductive season

Little is known about the energy conservation strategies of free-ranging marsupials living in resource-poor Australian deserts. We studied activity patterns and torpor of free-living mulgaras (Dasycercus blythi) in arid central Australia during the winter of 2006. Mulgaras are small (approximately 75 g), nocturnal, insectivorous marsupials, with a patchy distribution in hummock grasslands. Mulgaras (six males, three females) were implanted intraperitoneally with temperature-sensitive transmitters and monitored for 6-55 d. Temperature profiles for different microhabitats and the thermal properties of soil and a number of burrows were also measured. Air temperature ranged from -3 degrees C at night to 30 degrees C during the day. Although burrows buffered temperature extremes, the thermal diffusivity of the sandy soil was high, and many burrows were shallow. Hence, soil and burrow temperatures averaged about 15 degrees C. The activity of mulgaras was often restricted to a few hours after sunset, before they retired into their burrows. Mulgaras employed torpor frequently, often entering torpor during the night and arousing around midday, with arousals occurring later on cooler days. Shallow burrows allowed cooling below mean T(soil). Consequently, body temperatures as low as 10.8 degrees C were observed. The longest torpor bout was 20.8 h. Torpor patterns changed seasonally and differed between males and females. From June to August, females entered torpor almost daily despite mating and gestation, but from the end of the gestation period onward, they remained normothermic. In contrast, males showed only shallow and short torpor during the mating season, but from mid-July, a transition to more frequent and deeper torpor resembling that of females was observed. Apparently, in both sexes, the reproductive effort entails energetic costs, but torpor, as an energy-saving mechanism, and reproduction are not exclusive in mulgaras. In a resource-poor environment during the least productive part of the year, frequent torpor seems to provide the means to compensate for the increased energetic costs associated with reproduction.     

Weather conditions during hunting season affect the number of harvested roe deer (Capreolus capreolus)

Due to human‐induced climate and landscape changes, distribution and abundance of many ungulate species have increased worldwide. Especially in areas where natural predators are absent, hunting is the essential management tool for regulating ungulate populations. Therefore, understanding the factors associated with harvest rates is the first step toward an adaptive management approach. Weather influences hunter and ungulate behavior and thus presumably harvest, but how and which meteorological parameters are linked to harvest numbers have rarely been evaluated. We used nearly 65,000 “sit and wait” and driven hunt harvests of roe deer (Capreolus capreolus) in Bavaria, Germany, and weather data from 2008 to 2017 to test for factors affecting roe deer harvests (i.e., temperature, rain hours, wind speed, sunshine duration, snow depth, workdays vs. weekends, month) using zero‐inflated negative binomial mixed‐effect models. Our results reveal that, besides workdays, high temperatures and prolonged rain resulted in fewer harvested animals, whereas sunshine duration in summer and snow height in snow‐rich areas partially favored harvests during sitting hunts in summer and winter, respectively. The influence of wind speed varied over the course of the year. In summer and autumn, wind speed commonly had a negative effect, positively affecting harvests in winter in some regions. Daily harvest numbers decreased during the summer and autumn hunting periods (May till mid‐October), while they increased during the winter period (mid‐October till mid‐January). Interestingly, harvest success during driven hunts, which are planned well in advance and therefore take place largely independent of weather conditions, was similarly affected by the weather. This result suggests that the inferred weather influence is not only due to the hunters'' decisions but also due to deer behavior. Since many ungulate populations may further benefit from climate change, building an understanding of the relationship between hunting success and weather will aid adaptive ungulate management.     

Ecological conditions during winter affect sexual selection and breeding in a migratory bird

Populations of migratory birds have undergone marked declines, although the causes and mechanisms remain unknown. Because environmental effects on population dynamics are mediated by the effects of ecological factors on individuals, understanding changes in individual phenotypes in response to ecological conditions is key to understanding population trends. We show that breeding individuals of a declining population of trans-Saharan migratory barn swallows, Hirundo rustica, were affected by environmental conditions, as estimated from the normalized difference vegetation index (NDVI), reflecting primary production, in their winter quarters. The breeding dates of the same individuals in consecutive breeding seasons were advanced and clutch sizes were larger after winters with high NDVI in the winter quarters. Feather moult was also affected by winter conditions, with consequences for male sexual attractiveness. Length of tail ornament was positively correlated with NDVI during the previous winter, and males with large tail ornaments reproduced earlier and had larger clutches. The mean annual breeding date of the population was earlier and breeding success was increased after favourable winters, but this result was mainly determined by a single winter with very low NDVI. Thus, ecological conditions in Africa influence individual performance and productivity in a barn swallow population.     

Coastal dune stability: The effect of meteorological conditions and vegetation

Quantitative investigations and research conducted along the north coast of New South Wales, Australia are evaluated with respect to coastal processes, coastal alignment, meteorological data, dune dimensions, dune vegetative cover, development on the dunal area and dune management.The data available covered an assessment of the extent of dune instabilities, an assessment of long term coastline movements, a study of the effect of a cyclone and storm surge, and an assessment and evaluation of a phase of extreme coastline erosion. Specific situations are described and evaluated within the above context. The evaluations are used to determine the extent of coastal dune areas required to be designated as buffer zone in land use planning. The extent of the zone required is dependent upon expected magnitude of wave erosion. Magnitude of wave erosion was found to be proportional to the interaction of coastal processes during periods of extreme erosive factors and the beach dune characteristics for the particular section of coastline. It was found that man's influence on this natural interaction can be a dominating factor in determining beach dune characteristics and therefore the magnitude of wave erosion. — management of the beach dunal area to maintain an acceptable dynamic equilibrium of the beach dune line by a vegetated sand dune of specific dimensions is possible despite weather conditions, if a designated buffer zone is maintained.Presented at the Seventh International Biometeorological Congress, 17–23 August 1975, College Park, Maryland, USA.     

When season does not matter: summer and winter trophic ecology of Arctic amphipods

Polar marine ecosystems’ functioning is known to be strongly affected by the seasonality of water column production. However, a response of benthic organisms may range from close coupling to total decoupling from seasonal variability of environmental processes, depending on a feeding strategy. In this study, we used a multi-method approach (gut content, lipid and stable isotope analyses) to examine trophic ecology and major food sources of a large set of Arctic sub-littoral amphipods, and to evaluate whether their feeding strategies undergo seasonal changes. The wide range of δ¹⁵N values (5.45-12.43‰) indicates that amphipods form a trophic continuum from primary herbivores to carnivores/scavengers. Three main feeding modes, namely scavenging/predatory, deposit-feeding/predatory and phytodetrivory, were distinguished based on the multivariate analysis of whole fatty acid profiles. Total lipid content was low in all species and included primarily short-term energy reserves of triacylglycerols. In general, amphipods feeding habits appeared to be independent of the seasonal phytodetritial pulses. Low reliance on lipid reserves and lack of major changes in the trophic strategies over time suggest that these crustaceans feed continuously, taking advantage of a variety of food sources that are available year-round in shallow polar waters.     

Impact of Thromboprophylaxis across the US Acute Care Setting

Background

The risk of venous thromboembolism (VTE) can be reduced by appropriate use of anticoagulant prophylaxis. VTE prophylaxis does, however, remain substantially underused, particularly among acutely ill medical inpatients. We sought to evaluate the clinical and economic impact of increasing use of American College of Chest Physicians (ACCP)-recommended VTE prophylaxis among medical inpatients from a US healthcare system perspective.

Methods and Findings

In this retrospective database cost-effectiveness evaluation, a decision-tree model was developed to estimate deaths within 30 days of admission and outcomes attributable to VTE that might have been averted by use of low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH). Incremental cost-effectiveness ratio was calculated using “no prophylaxis” as the comparator. Data from the ENDORSE US medical inpatients and the US nationwide Inpatient Sample (NIS) were used to estimate the annual number of eligible inpatients who failed to receive ACCP-recommended VTE prophylaxis. The cost-effectiveness analysis indicated that VTE-prevention strategies would reduce deaths by 0.5% and 0.3%, comparing LMWH and UFH strategies with no prophylaxis, translating into savings of $50,637 and $25,714, respectively, per death averted. The ENDORSE findings indicated that 51.1% of US medical inpatients were at ACCP-defined VTE risk, 47.5% of whom received ACCP-recommended prophylaxis. By extrapolating these findings to the NIS and applying cost-effectives analysis results, the full implementation of ACCP guidelines would reduce number of deaths (by 15,875 if using LMWH or 10,201 if using UFH), and was extrapolated to calculate the cost reduction of $803M for LMWH and $262M for UFH.

Conclusions

Efforts to improve VTE prophylaxis use in acutely ill inpatients are warranted due to the potential for reducing VTE-attributable deaths, with net cost savings to healthcare systems.