Asymmetric Responses of Primary Productivity to Altered Precipitation Simulated by Ecosystem Models across Three Long-term Grassland Sites

Field measurements of aboveground net primary productivity (ANPP) in temperate grasslands suggest that both positive and negative asymmetric responses to changes in precipitation (<i>P</i>) may occur. Under normal range of precipitation variability, wet years typically result in ANPP gains being larger than ANPP declines in dry years (positive asymmetry), whereas increases in ANPP are lower in magnitude in extreme wet years compared to reductions during extreme drought (negative asymmetry). Whether the current generation of ecosystem models with a coupled carbon–water system in grasslands are capable of simulating these asymmetric ANPP responses is an unresolved question. In this study, we evaluated the simulated responses of temperate grassland primary productivity to scenarios of altered precipitation with 14 ecosystem models at three sites: Shortgrass steppe (SGS), Konza Prairie (KNZ) and Stubai Valley meadow (STU), spanning a rainfall gradient from dry to moist. We found that (1) the spatial slopes derived from modeled primary productivity and precipitation across sites were steeper than the temporal slopes obtained from inter-annual variations, which was consistent with empirical data; (2) the asymmetry of the responses of modeled primary productivity under normal inter-annual precipitation variability differed among models, and the mean of the model ensemble suggested a negative asymmetry across the three sites, which was contrary to empirical evidence based on filed observations; (3) the mean sensitivity of modeled productivity to rainfall suggested greater negative response with reduced precipitation than positive response to an increased precipitation under extreme conditions at the three sites; and (4) gross primary productivity (GPP), net primary productivity (NPP), aboveground NPP (ANPP) and belowground NPP (BNPP) all showed concave-down nonlinear responses to altered precipitation in all the models, but with different curvatures and mean values. Our results indicated that most models overestimate the negative drought effects and/or underestimate the positive effects of increased precipitation on primary productivity under normal climate conditions, highlighting the need for improving eco-hydrological processes in those models in the future

Impact of change in maternal age composition on the incidence of Caesarean section and low birth weight: analysis of delivery records at a tertiary hospital in Tanzania, 1999–2005

<p>Abstract</p> <p>Background</p> <p>Previous studies on change in maternal age composition in Tanzania do not indicate its impact on adverse pregnancy outcomes. We sought to establish temporal changes in maternal age composition and their impact on annual Caesarean section (CS) and low birth weight deliveries (LBWT) at Muhimbili National Hospital in Tanzania.</p> <p>Methods</p> <p>We conducted data analysis of 91,699 singleton deliveries that took place in the hospital between 1999 and 2005. The data were extracted from the obstetric data base. Annual proportions of individual age groups were calculated and their trends over the years studied. Multiple logistic analyses were conducted to ascertain trends in the risks of CS and LBWT. The impact of age composition changes on CS and LBWT was estimated by calculating annual numbers of these outcomes with and without the major changes in age composition, all others remaining equal. In all statistics, a p value < 0.05 was considered significant.</p> <p>Results</p> <p>The proportion of teenage mothers (12–19 years) progressively decreased over time while that of 30–34 years age group increased. From 1999, the risk of Caesarean delivery increased steadily to a maximum in 2005 [adjusted OR = 1.7; 95%CI (1.6–1.8)] whereas that of LBWT declined to a minimum in 2005 (adjusted OR = 0.76; 95% CI (0.71–0.82). The current major changes in age trend were responsible for shifts in the number of CS of up to206 cases per year. Likewise, the shift in LBWT was up to 158 cases per year, but the 30–34 years age group had no impact on this.</p> <p>Conclusion</p> <p>The population of mothers giving birth at MNH is progressively becoming older with substantial impact on the incidence of CS and LBWT. Further research is needed to estimate the health cost implications of this change.</p

Implementing spring-foam technology to design a lightweight and comfortable aircraft seat-pan

This paper investigates whether spring-foam technology in an aircraft seat-pan can reduce weight and at the same time provide equal or better comfort. Firstly, through literature studies and using an iterative design process a prototype seat-pan was designed and developed using spring-foam technology. The (dis)comfort of this seat was compared with a standard aircraft seat-pan. Twenty two participants were asked to sit in each seat for 90 min, completing a questionnaire every 15 min. At the end of each seating session pressure map recordings were made of the seat-pans. The results showed that the prototype seat-pan has on average a significantly higher comfort for the first 30 min and at a 60 min recording than the standard seat-pan. The discomfort and long term comfort were not significantly influenced. The pressure distribution on the prototype seat-pan was significantly closer to an ideal pressure distribution than a conventional seat-pan. In addition, the prototype seat-pan had a significantly larger contact area and lower average pressure. The seat-cushion weighs 20% less than the conventional seat-cushion. The study indicates that a seat-pan design using spring-foam technology can be lighter and more comfortable than conventional foam cushion materials. It is recommended to optimize the prototype seat further and conduct long term (dis)comfort studies with a broader variation in subjects’ age.</p

Implementing spring-foam technology to design a lightweight and comfortable aircraft seat-pan

This paper investigates whether spring-foam technology in an aircraft seat-pan can reduce weight and at the same time provide equal or better comfort. Firstly, through literature studies and using an iterative design process a prototype seat-pan was designed and developed using spring-foam technology. The (dis)comfort of this seat was compared with a standard aircraft seat-pan. Twenty two participants were asked to sit in each seat for 90 min, completing a questionnaire every 15 min. At the end of each seating session pressure map recordings were made of the seat-pans. The results showed that the prototype seat-pan has on average a significantly higher comfort for the first 30 min and at a 60 min recording than the standard seat-pan. The discomfort and long term comfort were not significantly influenced. The pressure distribution on the prototype seat-pan was significantly closer to an ideal pressure distribution than a conventional seat-pan. In addition, the prototype seat-pan had a significantly larger contact area and lower average pressure. The seat-cushion weighs 20% less than the conventional seat-cushion. The study indicates that a seat-pan design using spring-foam technology can be lighter and more comfortable than conventional foam cushion materials. It is recommended to optimize the prototype seat further and conduct long term (dis)comfort studies with a broader variation in subjects’ age.Circular Product DesignMechatronic DesignApplied Ergonomics and Desig

GYNECOLOGICAL MALIGNANCY IN BPKMCH, BHARATPUR: A RETROSPECTIVE ANALYSIS OF 321 CASES

Gynecological Malignancy is the leading cancer in female not only in Nepal but worldwide. A retrospective study of histopathological specimens was conducted in BPKMCH Bharatpur from July 1999 to January 2001, duration of 19 months. Total 321 cases of Gynecological Malignancy were diagnosed in Department of Pathology of BPKMCH. Out of which 272(84.73%) cases of cancer of cervix; 17 cases (5.29%) of cancer of vulva; 14 cases (4.36%) of ovarian cancer, 12 cases (3.73%) of cancer of vagina and 6 cases (1.86%) of endometrial cancer were detected. Cancer of cervix was most common in 40-49 years age group followed by 50-59 years age group. Mean age of the patients with cancer of cervix was 50 years and 10 months; minimum of 29 years and maximum of 76 years. Out of 272 cases of cancer of cervix, 266 (97.79%) were squamous cell carcinoma and rest 6 (2.20%) were adenocarcinoma. Commonest histology in vulva and vagina was squamous cell carcinoma, whereas adenocarcinoma was commonest in endometrium and ovary. The higher incidence of gynecological malignancies particularly carcinoma of cervix was observed in BPKMCH. Key Words: Cancer, Cervix, Vagina, Vulva, Ovary

Revisiting enteric methane emissions from domestic ruminants and their δ13CCH4 source signature reflecting diet and environmental shifts

The dataset provide data supporting the findings of the above publication (Chang et al., 2019). The dataset contains global, regional and country level data of 1) feed intake (dry matter) by livestock (poultry, pigs and ruminants), 2) C3-C4 diet composition of domestic ruminants, 3) enteric methane emissions from ruminants, and 4) the δ13CCH4 source signature of the methane emissions. Annual data for the period 1961-2012 are provided

Effects of a hand luggage guiding system on airplane boarding time and passenger experience

Airplane boarding is a time-consuming procedure due to a number of factors. First of all, passengers cannot pass each other in the aisles, but also stress is experienced in finding the seat or the space to store hand luggage and some passengers repack their luggage in the aisle. To reduce boarding time and improve the overall boarding experience a light guiding hand luggage system (GHL-System) was developed within the PASSME project. Due to the GHL passengers in the airplane see a light in the overhead bin which will shine more bright coming closer. This GHL-system did reduce stress levels while boarding and indicated a time saving of 3-4 minutes on a Boeing 737-800 flight with 189 passengers. Indicating a personal luggage spot located near the passenger seat might solve the problem of passengers not being able to find their space. Further research is needed on actual flight conditions to prove the effect of this system.Mechatronic DesignApplied Ergonomics and Desig

Improving airplane boarding time: A review, a field study and an experiment with a new way of hand luggage stowing

The airplane (de)boarding process is not organized optimally. The goal of this paper is to search for improvement possibilities. In this paper literature is reviewed, boarding characteristics are studied in a field study and a pilot study with a new way of hand luggage stowing is performed. Computer simulations indicate that there are more efficient boarding methods than those currently in use, like the reverse pyramid method which starts window seat columns in the back and ends with aisle seat columns in the front. The literature also shows that hand luggage stowing in the overhead lockers can block other passengers increasing the boarding time. Also, the field observations and the pilot test indicate that hand luggage stowing could block the aisle and is one of the main elements in boarding that influences passenger experience and boarding time. Training and preparing the boarding process could potentially reduce the boarding time by 3-4 minutes, but further research is needed to prove this.Applied Ergonomics and Desig

Magnitude and uncertainty of nitrous oxide emissions from North America based on bottom‐up and top‐down approaches: Informing future research and national inventories

International audienceWe synthesized N2O emissions over North America using 17 bottom-up (BU) estimates from 1980–2016 and five top-down (TD) estimates from 1998 to 2016. The BU-based total emission shows a slight increase owing to U.S. agriculture, while no consistent trend is shown in TD estimates. During 2007–2016, North American N2O emissions are estimated at 1.7 (1.0–3.0) Tg N yr−1 (BU) and 1.3 (0.9–1.5) Tg N yr−1 (TD). Anthropogenic emissions were twice as large as natural fluxes from soil and water. Direct agricultural and industrial activities accounted for 68% of total anthropogenic emissions, 71% of which was contributed by the U.S. Our estimates of U.S. agricultural emissions are comparable to the EPA greenhouse gas (GHG) inventory, which includes estimates from IPCC tier 1 (emission factor) and tier 3 (process-based modeling) approaches. Conversely, our estimated agricultural emissions for Canada and Mexico are twice as large as the respective national GHG inventories.Nitrous oxide (N2O) is the third most important greenhouse gase (GHG) after CO2 and CH4 causing global warming. Among world regions, North America (defined herein as U.S., Canada, and Mexico) is the second largest source of N2O emissions globally, and previous source estimates for this region vary widely. This study aims to provide a comprehensive N2O assessment over North America including all available estimates based on a number of approaches. We report total emissions, and emissions from four anthropogenic source sectors, over the past four decades. Agriculture and industry are two major N2O sources in North America. Our results show a minor increase in the total N2O emission due to agricultural trends in the U.S. Our bottom-up estimate of U.S. agricultural N2O emissions are close to those in the EPA national GHG inventory that includes both empirical and model results. The high consistency suggests the need to take process-based modeling results into account for future national GHG inventories