Energy Balance Index Research Articles

Spatial sensitivity of surface energy balance algorithms to meteorological data in a heterogeneous environment

Abstract Increasing demand for water security requires improved accuracy in water accounting. Quantification of actual evapotranspiration is an essential part of this accounting and is frequently derived from surface energy balance (SEB) models that combine satellite remote sensing and on-ground measurements of meteorological data. However, many of the world's major water supply catchments are highly heterogeneous with land types, vegetation communities, and topography varying spatially. We compared the performance of seven meteorological interpolation methods and three SEB algorithms (the Simplified Surface Energy Balance Index (S-SEBI), the Hybrid Dual-Source Scheme and Trapezoid Framework-Based Evapotranspiration Model (HTEM), and the Surface Energy Balance System (SEBS)), testing their sensitivity to meteorological and remotely sensed inputs in a heterogeneous environment. Under a two dimensional framework, accuracy of interpolation methods varied among SEB meteorological inputs, suggesting that combining methods could improve overall accuracy. SEB algorithms were influenced by the density, type, and variability of meteorological inputs and sensitivity analysis showed that wind speed and air temperature were almost as influential as surface temperature for HTEM and SEBS. SEBS was the most sensitive to meteorological variability caused by choice of interpolation method when analysed globally, while HTEM was the most sensitive to local meteorological variation at flux towers. S-SEBI's simple structure made it the least sensitive to meteorological inputs and interpolation methods. Continued improvement in spatially explicit interpolation methods, combined with increased densities of meteorological stations, will increase accuracy and confidence in remotely sensed SEB fluxes, contributing to improved water accounting in heterogeneous catchments.

Estimation of Surface Soil Moisture in Irrigated Lands by Assimilation of Landsat Vegetation Indices, Surface Energy Balance Products, and Relevance Vector Machines

Spatial surface soil moisture can be an important indicator of crop conditions on farmland, but its continuous estimation remains challenging due to coarse spatial and temporal resolution of existing remotely-sensed products. Furthermore, while preceding research on soil moisture using remote sensing (surface energy balance, weather parameters, and vegetation indices) has demonstrated a relationship between these factors and soil moisture, practical continuous spatial quantification of the latter is still unavailable for use in water and agricultural management. In this study, a methodology is presented to estimate volumetric surface soil moisture by statistical selection from potential predictors that include vegetation indices and energy balance products derived from satellite (Landsat) imagery and weather data as identified in scientific literature. This methodology employs a statistical learning machine called a Relevance Vector Machine (RVM) to identify and relate the potential predictors to soil moisture by means of stratified cross-validation and forward variable selection. Surface soil moisture measurements from irrigated agricultural fields in Central Utah in the 2012 irrigation season were used, along with weather data, Landsat vegetation indices, and energy balance products. The methodology, data collection, processing, and estimation accuracy are presented and discussed.

Evaluating five remote sensing based single-source surface energy balance models for estimating daily evapotranspiration in a humid subtropical climate

In the last two decades, a number of single-source surface energy balance (SEB) models have been proposed for mapping evapotranspiration (ET); however, there is no clear guidance on which models are preferable under different conditions. In this paper, we tested five models-Surface Energy Balance Algorithm for Land (SEBAL), Mapping ET at high Resolution with Internalized Calibration (METRIC), Simplified Surface Energy Balance Index (S-SEBI), Surface Energy Balance System (SEBS), and operational Simplified Surface Energy Balance (SSEBop)—to identify the single-source SEB models most appropriate for use in the humid southeastern United States. ET predictions from these models were compared with measured ET at four sites (marsh, grass, and citrus surfaces) for 149 cloud-free Landsat image acquisition days between 2000 and 2010. The overall model evaluation statistics showed that SEBS generally outperformed the other models in terms of estimating daily ET from different land covers (e.g., the root mean squared error (RMSE) was 0.74mmday−1). SSEBop was consistently the worst performing model and overestimated ET at all sites (RMSE=1.67mmday−1), while the other models typically fell in between SSEBop and SEBS. However, for short grass conditions, SEBAL, METRIC, and S-SEBI appear to work much better than SEBS. Overall, our study suggests that SEBS may be the best SEB model in humid regions, although it may require modifications to work better over short vegetation.

Remote Sensing of Evapotranspiration in a Southern Mediterranean Forest. Application to Bissa Forest, Algeria

The Simplified Surface Energy Balance Index (S-SEBI) algorithm was used in this study with four Landsat-5 Thematic Mapper images to assess the evapotranspiration (ET) in Bissa forest, one of the healthiest Algerian forests located south of the Mediterranean Sea. Results showed that ET varies over the different seasons, the highest ET values were reached during the spring due to water availability, whereas, the lowest values were recorded during the summer. The relationship between normalized difference vegetation index (NDVI) and ET showed that the highest ET values coincide always with the highest NDVI except for January where even the lowest NDVI values correspond to higher ET. The intensity of ET was closely related to aspects, southeastern exposures showed the highest ET, whereas, northwestern exposures showed the lowest ET.

The effect of breakfast on appetite regulation, energy balance and exercise performance.

The belief that breakfast is the most important meal of day has been derived from cross-sectional studies that have associated breakfast consumption with a lower BMI. This suggests that breakfast omission either leads to an increase in energy intake or a reduction in energy expenditure over the remainder of the day, resulting in a state of positive energy balance. However, observational studies do not imply causality. A number of intervention studies have been conducted, enabling more precise determination of breakfast manipulation on indices of energy balance. This review will examine the results from these studies in adults, attempting to identify causal links between breakfast and energy balance, as well as determining whether consumption of breakfast influences exercise performance. Despite the associations in the literature, intervention studies have generally found a reduction in total daily energy intake when breakfast is omitted from the daily meal pattern. Moreover, whilst consumption of breakfast supresses appetite during the morning, this effect appears to be transient as the first meal consumed after breakfast seems to offset appetite to a similar extent, independent of breakfast. Whether breakfast affects energy expenditure is less clear. Whilst breakfast does not seem to affect basal metabolism, breakfast omission may reduce free-living physical activity and endurance exercise performance throughout the day. In conclusion, the available research suggests breakfast omission may influence energy expenditure more strongly than energy intake. Longer term intervention studies are required to confirm this relationship, and determine the impact of these variables on weight management.

On Uncertainties of the Priestley-Taylor/LST-Fc Feature Space Method to Estimate Evapotranspiration: Case Study in an Arid/Semiarid Region in Northwest China

Accurate evapotranspiration (ET) estimation is very crucial for water resource management, particularly for the arid and semi-arid region. The remote sensing-based Priestley-Taylor method (RS-PT method) can estimate ET at regional scale, using the feature space of remotely sensed land surface temperature (LST) and vegetation index (VI). This study evaluates the RS-PT feature space method over an arid and semi-arid region in northwest China using satellite data from the moderate-resolution space-borne sensor Advanced Along-Track Scanning Radiometer (AATSR), the observations from the high-resolution airborne sensor Wide-angle Infrared Dual-mode line/area Array Scanner (WiDAS) and ground measurements of heat fluxes collected in summer 2008. The results show that the mean difference for latent heat flux (LE) estimates resulting from different domain sizes is 69.5 W/m2. When using high-resolution images from airborne measurements, the dry boundary is strongly affected by the pixels of impervious surfaces, which lead to a mean difference of 15.36 W/m2 for LE estimates. In addition, the physically based Surface Energy Balance Index (SEBI) model is used to analyze the accuracy of dry/wet boundaries in the RS-PT method. Compared with the SEBI-estimated relative evaporative fraction (Λr), the RS-PT method underestimated Λr by ~0.11. For the RS-PT method, the uncertainty in the determination of the dry/wet boundaries has a significant impact on the accuracy of the ET estimate, not only depending on the size of the area to build the feature space, but also on the land covers.

Energy saving potential of semi-transparent photovoltaic elements for building integration

Within the building energy saving strategies, BIPV (building integrated photovoltaic systems) present a promising potential based on the close relationship existing between these multifunctional systems and the overall building energy balance. Building integration of STPV (semi-transparent photovoltaic) elements affects deeply the building energy demand since it influences the heating, cooling and lighting loads as well as the local electricity generation. This work analyses over different window-to-wall ratios the overall energy performance of five STPV elements, each element having a specific degree of transparency, in order to assess the energy saving potential compared to a conventional solar control glass compliant with the local technical standard. The prior optical characterization, focused to measure the spectral properties of the elements, was experimentally undertaken. The obtained data were used to perform simulations based on a reference office building using a package of specific software tools (DesignBuilder, EnergyPlus, PVsyst, and COMFEN) to take proper account of the STPV peculiarities. To evaluate the global energy performance of the STPV elements a new Energy Balance Index was formulated. The results show that for intermediate and large façade openings the energy saving potential provided by the STPV solutions ranges between 18% and 59% compared to the reference glass.

Relationship between whole-body macronutrient oxidative partitioning and pancreatic insulin secretion/β-cell function in non-diabetic humans

BackgroundGlucose-stimulated insulin secretion correlates inversely with the degree of whole-body insulin sensitivity suggesting a crosstalk between peripheral organs and pancreas. Such sensing mechanism could be mediated by changes in glucose flux (uptake, oxidation or storage) in peripheral tissues that may drive insulin secretion. AimTo relate whole-body non-protein respiratory quotient (npRQ), an index of macronutrient oxidative partitioning, with insulin secretion and β-cell function in non-diabetic individuals. MethodsMacronutrient oxidation was measured after an overnight fast and for 4h after a 75-g oral glucose tolerance test (OGTT) in 30 participants (15/15 males/females; 35±12y; 27±4kg/m2). Furthermore, npRQ was assessed for 24h in a metabolic chamber. Insulin secretion was estimated by deconvolution of serum C-peptide concentration (fasting and 4-h OGTT) and from 24-h urinary C-peptide excretion corrected for energy intake (metabolic chamber). β-Cell function parameters were obtained by mathematical modeling, while insulin sensitivity was determined by a euglycemic–hyperinsulinemic clamp (120mU·m−2·min−1). ResultsInsulin secretion (from 24-h urinary C-peptide) correlated inversely with 24-h npRQ (r=−0.61; p=0.001), even after controlling for insulin sensitivity, energy balance, age and body mass index (r=−0.52; p=0.01). In turn, insulin secretion (from serum C-peptide) was not associated with fasting or OGTT npRQ. However, fasting npRQ was positively correlated with rate sensitivity (r=0.40; p<0.05) and marginally with glucose sensitivity (r=0.34; p=0.08). ConclusionMacronutrient oxidative partitioning, specifically glucose oxidation, might play a role on the regulation of insulin secretion. Further studies should aim at identifying the signals linking these processes.

Water allocation and water consumption of irrigated agriculture and natural vegetation in the Aksu-Tarim river basin, Xinjiang, China

A significant part of the world's largest river basins are located in areas of arid and semi-arid climate, such as the Amu Darya, Jordan, Murray-Darling, Yellow River, and Aksu-Tarim river basin. These river basins are experiencing water scarcity resulting in conflicts between upstream and downstream, conflicts between water users, and degradation of the natural ecosystems. Therefore, in many river basins, including the Aksu-Tarim river basin, water quota systems have been established, in order to allocate water under scarcity. The Aksu-Tarim river basin (NW China) has developed into one of the most important cotton production areas worldwide. In this paper, we aim at assessing the water consumption through irrigated agriculture, mainly cotton, and natural vegetation in the Aksu-Tarim river basin against the background of this water quota system. Firstly, we map the evapotranspiration (ETa) as water consumption of irrigated agriculture and natural vegetation in the Aksu-Tarim river basin. Secondly, we calculate water balances and relate them to the water quota system. We employed the remote sensing method Simplified Surface Energy Balance Index (S-SEBI), in order to map ETa based on MODIS satellite images for the growing seasons 2009, 2010, and 2011. Thereby, the MODIS products 8-day land surface temperature (MOD11A2), 16-day albedo (MCD43A3), and 16-day NDVI (MOD13A1) were used. The ETa of cotton ranges from 884 to 1198 mm. The ETa of the natural vegetation of a total coverage ranges from 715 in 2009 to 960 mm in 2011, clearly following the annual runoff of the Aksu and Tarim River. The water balance of the Aksu-Tarim river basin is −3.25 to −3.73 km3, 0.1–0.53 km3, and −3.55 to −4.12 km3 in 2009, 2010, and 2011, respectively. The water quotas along the Aksu River and the upper reaches of the Tarim are exceeded by water consumption, while the quotas along the middle and lower reaches are not met. Considerable amounts of groundwater, including fossil groundwater, are exploited for irrigation along the Aksu and Tarim River, which must be regarded as exploitation of a non-renewable resource.

Impacts of the broadband albedo on actual evapotranspiration estimated by S-SEBI model over an agricultural area

Surface albedo and emissivity are essential variables in surface energy balance. In recent decades, several land surface energy models have used both surface broadband albedo and emissivity in order to achieve reliable evapotranspiration retrievals on a daily basis. Despite these improvements in surface energy models, we noticed an assumption that most studies make when using this framework. It assumes that the surface broadband albedo and emissivity can be estimated directly as a weighted average of spectral surface bi-directional reflectances, and as a weighted average of spectral surface emissivities retrieved at a given view angle, respectively. However, this approach does not take into account surface anisotropy, which is described by the Bi-directional Reflectance Distribution Function (BRDF) in the case of the surface albedo. In this paper, we analyze the influence that estimating land surface albedo directly from the surface reflectance (αREF) or through the BRDF integration (αBRDF) has on the estimation of energy balance components (net radiation, latent and sensible heat fluxes and evapotranspiration) by using the Simplified Surface Energy Balance Index (S-SEBI). To this end, in-situ data and remote sensing images acquisitioned at different view zenith angles (VZA) such as 0°, ±40° and ±57° by the Airborne Hyperspectral Scanner (AHS) over an agricultural area were used. Results show high variation in αREF depending on the VZA when compared to αBRDF, with the highest difference observed in the backward scattering direction along the hot spot region (RMSE of 0.11 and relative error of 65%). Net radiation gives relative errors from 6 to 17%, with the maximum error obtained in the images that include the hot spot effect, whereas significant changes are not observed in case of the ground heat flux and the evaporative fraction. However, sensible heat flux, latent heat flux and daily evapotranspiration show relative errors ranging between 23–39%, 6–18% and 5–15% respectively. In a future study, the influence of estimating surface emissivity directly from the average of spectral emissivities under a given view angle or using a hemispherical value will be analyzed.

TVDI模型的农业旱情时空变化遥感应用研究

温度植被干旱指数（TVDI）是一种通过反演土壤湿度来反映农业干旱状况的重要方法，其中能量平衡和植被指数的变化是影响TVDI模型精度的主要因子。在研究比值植被指数（RVI）、归一化植被指数（NDVI）、增强型植被指数（EVI）和修正土壤调节植被指数（MSAVI）和下垫面温度（<em>T</em>_s）的基础上，引入DEM数据并对<em>T</em>_s做地形校正，减少了地形起伏对能量平衡的影响，建立不同植被指数的<em>T</em>_s-Ⅵ特征空间，选择与土壤湿度相关性最好的温度植被干旱指数（TVDI），获取研究区2005年作物生长季（5-9月）的干旱状况，并用同步的气象信息对干旱状况进行验证。结果表明：根据不同时期采用不同植被指数的TVDI模型，经过地形校正后能够更好地反映研究区的农业干旱状况。;Temperature Vegetation Dryness Index (TVDI) is an important tool that reflects agriculture dry situation by inverting soil moisture. The changes of energy balance and vegetation index are two main factors to influence the precision of the TVDI. The MODIS (Moderate….) data products, as RVI(Ratio Vegetation Index), NDVI(Normalized Difference Vegetation Index), EVI(Enhanced Vegetation Index), MSAVI(Modified Soil Adjusted Vegetation Index), and <em>T</em>_s (Land Surface Temperatures), are applied and the DEM (ASTER-GDEM) data are used to correct the <em>T</em>_s data for the reduction of the topographic influences by topographic relief. The TVDI is then employed by comparison of different vegetation index, where the TVDI is more sensitive to soil moisture. Thus the dry situation in the study area is analyzed during the plant growth time and compared by the synchronous meteorology data. The results indicate that: (1) terrain correction can effectively prevent the decrease of TVDI value from a lower surface temperature for a higher pixel. The correlation between <em>T</em>_s-NDVI index and measured values on May is compared, <em>R</em>< sup>2</sup> will increase from 0.4634 to 0.5859 by terrain correction. It shows that the terrain corrected TVDI can improve effectively the estimation of soil moisture. (2) By comparing the correlation between <em>T</em>_s-NDVI, <em>T</em>_s-EVI, <em>T</em>_s-RVI, <em>T</em>_s-MSAVI and soil moisture,all the TVDIs present the negative correlations with soil moisture. The best correlations between the soil moisture and TVDIs can be always found, such as <em>T</em>_s-MSAVI in June, July and September 2005, <em>T</em>_s-EVI in May, and <em>T</em>_s-NDVI in August. Thus a TVDI feature space for different periods by these vegetation indexes are built for inversion of drought conditions. By comparison with agricultural meteorology, the results are acceptable. (3) Large area of the study area was humid from May to September 2005, drought occurred in the West on August, and humid was located in East on June. Therefore, compared with the measured data, the terrain corrected TVDI model is robust to eliminate the terrain and land cover influences to land surface temperature for inversion of soil moisture in the study area. And it is faithful to predict the agricultural drought condition in the study area during 2005 crop growth season.

Estimation of real evapotranspiration and its variation in Mediterranean landscapes of central-southern Chile

Evapotranspiration (ETd) is a key controller in the ecohydrological processes of semi-arid landscapes. This is the case of the dry land in Chile's central-southern zone, where forestry, farming and livestock activities must adapt to precipitation with considerable year-on-year variations. In this study, the spatial distribution of ETd was estimated in relation to the land use map and physical parameters of the soil. The ETd was estimated through the Simplified Surface Energy Balance Index (S-SEBI) using data from weather stations and remote data provided by the ASTER and MODIS sensors for November 2004 and 2006, respectively. The spatial variability of ETd was compared among different plant types, soil textural classes and depths using non-parametric statistical tests. In this comparison, the highest rates of ETd were obtained in the forest covers with values of 7.3 ± 0.8 and 8.4 ± 0.8 mm d−1 for 2004 and 2006, respectively. The lowest values were estimated for pastures and shrublands with values of 3.5 ± 1.2 mm d−1 and for crops with rates of 4.4 ± 1.6 mm d−1. Comparison of the ETd of the native forest covers and plantations of exotic species showed statistically significant differences; however, no great variation was noted, at least in the study months. Additionally, the highest rates of ETd were found in the clay loam textures (6.0 ± 1.8 and 6.4 ± 2.0 mm d−1) and the lowest rates in the sandy loam soils (3.7 ± 1.6 and 3.9 ± 1.6 mm d−1) for 2004 and 2006, respectively. The results enable analysis of the spatial patterns of the landscape in terms of the relation between water consumption, ET and the biophysical characteristics of a Mediterranean ecosystem. These results form part of the creation of tools useful in the optimization of decision-making for the management and planning of water resources and soil use in territories with few measuring instruments.

Estimate energy, energy balance and economic indices of watered farming Potato Production in North of Iran

Efficient use of energy in agriculture is one of the conditions for sustainable production. The aim of this study was to determine the amount of input-output energy used in watermelon production and to make an economic analysis of watermelon production under watered farming in Guilan province, Iran. In this article, evaluation of energy balance and energy indices under watered farming watermelon in north of Iran (Guilan province) were investigated. Data were collected from 72 farms by used a face to face questionnaire method during 2010 year in Guilan province. By using of consumed data as inputs and total production as output, and their concern equivalent energy, energy balance and energy indices were calculated. Energy efficiency (energy output to input energy ratio) for yield in this study was calculated 1.75; showing the affective use of energy in the agro ecosystems watermelon production. Energy balance efficiency (production energy to consumption energy ratio) for yield in this study was calculated 0.55; showing the affective use of energy in the agro ecosystems watermelon production. Results of economic analysis showed the benefit to cost ratio in the studied farms was calculated to be 1.88. Therefore watermelon production was a cost effective business based on the data of the 2010 season of watermelon production under watered farming in north of Iran.

Evaluation green house gases and energy of pumpkin production in north of Iran

Energy has a key role in social-economic development of countries. Efficient use of energy in agriculture is one of the conditions for sustainable production. In this article, evaluation of energy balance and energy indices under dry land farming pumpkin in north of Iran (Guilan province) were investigated. Data were collected from 72 farms by used a face to face questionnaire method during 2011 year in Guilan province. By using of consumed data as inputs and total production as output, and their concern equivalent energy, energy balance and energy indices were calculated. Energy efficiency (energy output to input energy ratio) for seed and fruit in this study were calculated 0.16 and 1.43 respectively; showing the affective use of energy in the agro ecosystems pumpkin production. Energy balance efficiency (production energy to consumption energy ratio) for seed and fruit in this study were calculated 0.09 and 1.54 respectively; showing the affective use of energy in the agro ecosystems pumpkin production.

Long-term oral drenching of crude glycerol to primiparous dairy cows in early lactation

The objective of this experiment was to study the long-term effects of supplemental oral drenching of crude glycerol (CG) on feed intake, milk yield and composition, plasma metabolites and energy balance indices of primiparous dairy cows in early lactation. Fourteen primiparous Holstein dairy cows were paired according to body weight (BW) and body condition score (BCS) at calving, and allocated at random to either a treatment or a control group. Both groups were fed a basal diet, containing 11.4MJkg−1 DM metabolisable energy and 103g/kg DM metabolisable protein, twice a day. Silage (ad libitum) and a pelleted concentrate mixture with mineral mix were fed separately during the three six-day periods from days 4 to 21 post partum. An oral drench of 500ml of CG mixed with lukewarm water was fed supplementally before the morning feedings to the treatment groups, while the control group were given no oral drench. Blood samples were collected on two consecutive days at the end of each six-day period before administration of glycerol. Results showed that long-term administration of CG increased silage intake (P<0.001), and total dry matter intakes (DMI; P=0.023). Oral drenching with glycerol increased milk yields (P<0.01), and milk lactose content (P<0.001). Supplemental glycerol had no effect on estimates for milk energy, milk constituent ratios or milk acetone content. No differences in BCS changes or on concentrations of plasma glucose, insulin, and β-hydroxybutyrate (BHB) were found between the two groups. Dairy cows given oral glycerol had lower concentrations of plasma urea (P=0.005) during the post partum period. There was a treatment and time interaction effect on the non-esterified fatty acids (NEFA) concentration (P=0.048), although this was complex, and the only period of significant differences was in the first six-day period, when NEFA concentration was higher (P=0.025) in the control group. The data indicate that prolonged oral drenching of supplemental CG in the early lactation period improves total DMI, and therefore has a positive effect on milk yield of primiparous dairy cows in this period.

A comparative study on energy balance and economical indices in irrigated and dry land barley production systems

This study was conducted to determine how energy balances and economical indices of barley production are affected by irrigated and dry land farming systems. Data were collected from 26 irrigated and 68 dry land barley farms. The complimentary data were collected through questionnaires filled by farmers in face-to-face interviews during 2010. The results indicated that total energy input for irrigated barley was 19,308.96 MJ ha−1 and for dry land barley was 7,867.82. The non-renewable energy was about 66.83 and 71.02 % in irrigated and dry land systems while the renewable energy was 33.17 and 28.98 %, respectively. Energy use efficiency is energy output MJ ha−1 divided by energy input MJ ha−1. Energy use efficiency was 5.3 and 3.96 in dry land and irrigated systems, respectively. Although net return in the irrigated system (266.13$ ha−1) was greater than that in the dry land system (208.64) but the benefit to cost ratio in irrigated system (1.38) was lower than that in the dry land system (1.58). Results showed that human labor as well as machinery energy inputs were the most important inputs influencing the dry land and irrigated barley production systems, respectively. The second important input in the irrigated barley was electricity (with 0.16) which was followed by water for irrigation and diesel fuel (0.14 and 0.13, respectively). In total energy consumption, the ratio of non-renewable energy was greater than that of renewable energy. Since the main non-renewable energy input was diesel, electricity, and chemical fertilizers; therefore, management and improvement in the application of these inputs would increase the proportion of renewable energy.

A comparative climate analysis of heat-related emergency 911 dispatches: Chicago, Illinois and Phoenix, Arizona USA 2003 to 2006

Research into the health impacts of heat has proliferated since 2000. Temperature increases could exacerbate the increased heat already experienced by urban populations due to urbanization. Heat-related mortality studies have found that hot southern cities in North America have not experienced the summer increases in mortality found in their more northern counterparts. Heat-related morbidity studies have not assessed this possible regional difference. This comparison study uses data from emergency 911 dispatches [referred to as heat-related dispatches (HRD)] identified by responders as heat-related for two United States cities located in different regions with very different climates: Chicago, Illinois in the upper midwest and Phoenix, Arizona in the southwest. Phoenix's climate is hot and arid. Chicago's climate is more temperate, but can also experience days with unusually high temperatures combined with high humidity. This study examines the relationships between rising HRD and daily temperatures: maximum (Tmax); apparent (ATmax): minimum (Tmin) and two energy balance indices (PET and UTCI). Phoenix had more HRD cumulatively, over a longer warm weather season, but did not experience the large spikes in HRD that occurred in Chicago, even though it was routinely subjected to much hotter weather conditions. Statistical analyses showed the strongest relationships to daily ATmax for both cities. Phoenix's lack of HRD spikes, similar to the summer mortality patterns for southern cities, suggests an avenue for future research to better understand the dynamics of possible physiological or behavioral adaption that seems to reduce residents' vulnerability to heat.

Physiological performance of juvenile Haliotis rufescens and Haliotis discus hannai abalone exposed to the withering syndrome agent

Withering syndrome (WS) is a serious chronic disease caused by infection with the bacterium Candidatus Xenohaliotis californiensis, a Rickettsiales-like organism (WS-RLO) that affects multiple abalone species in both natural and farmed populations. However, there is no available information regarding the effects of this disease on the physiological performance of infected abalone. We studied the effect of different levels of infection on components of energy balance and physiological indices (rates of absorption and assimilation, O/N ratio, and scope for growth) in the abalone species Haliotis rufescens and Haliotis discus hannai. Juveniles were exposed to C. X. californiensis transmission for 130days, during which time the presence/absence of WS-RLOs was evaluated by PCR (following DNA sequencing-based confirmation of 100% identity with the sequence of C. X. californiensis from California), and the prevalence and intensity of infection were evaluated via histological analysis. Among H. rufescens juveniles exposed to the bacterium, 92% became infected (positive by histology), and the intensity of infection ranged from low (degree 1) to moderate (degree 2). In contrast, no H. discus hannai juveniles were positive for WS-RLO by histology, although 23% were positive by PCR, possibly indicating incipient WS-RLO infection that did not develop during the experimental period or to mere presence of WS-RLO DNA in the sample. Infection of H. rufescens juveniles by WS-RLOs negatively affected all components of the energy balance and physiological indices, such as scope for growth and the O/N ratio, in direct relation to the degree of infection. The most strongly affected functions were the rate of ingestion, standard metabolism, and production of feces, which were reduced by 60–80% in the most highly infected individuals. The reduced energy intake in the organisms produced a strong energy imbalance such that the energy available for growth was reduced by 49% in infected organisms. In contrast, juveniles of H. discus hannai carrying the bacterium developed no infection and showed no alterations of physiological function. Our results indicate that the level of early infection by WS-RLOs may exert a negative effect on physiological activity in H. rufescens, even when the disease is not evident.

Evaluation energy balance and energy indices of peanut production in north of Iran

One way to evaluation of sustainable developing in agriculture is using of energy flow method. This method in an agricultural product system is the energy consuming in product operations and energy saving in produced crops. In this article, evaluation of energy balance and energy indices under rain fed farming peanut in north of Iran (Guilan province) was investigated. Data were collected from 72 farms by using a face to face questionnaire method during 2011 year in Guilan province. By using of consumed data as inputs and total production as output, and their concern equivalent energy, energy balance and energy indices were calculated. Energy efficiency (energy output to input energy ratio) in this study was calculated as 3.50, showing the affective use of energy in the agro ecosystems peanut production. Energy balance efficiency (production energy to consumption energy ratio) in this study was calculated as 2.73, showing the affective use of energy in the agro ecosystems peanut production.

EAR: An Energy and Activity-Aware Routing Protocol for Wireless Sensor Networks in Smart Environments

Sensor network, unlike traditional communication network, is deeply embedded in physical environments and its operation is mainly driven by the event activities in the environment. In long-term operations, the event activities usually show certain patterns which can be learned and exploited to optimize network design. However, this has been underexplored in the literature. One work related to this is using ATPG for radio duty cycling ([1]). In this paper we present a novel Energy and Activity aware Routing (EAR) protocol for sensor networks. As a case study, we have evaluated EAR with the data trace of real Smart Environments. In EAR an Activity Transition Probability Graph (ATPG) is learned and built from the event activity patterns. EAR is an online routing protocol, which chooses the next-hop relay node by utilizing: activity pattern information in the ATPG graph and a novel index of energy balance in the network. EAR extends network lifetime by maintaining an energy balance across the nodes in the network, while meeting application performance with desired throughput and low data delivery latency. We theoretically prove that: (a) the network throughput with EAR achieves a competitive ratio (i.e., the ratio of the performance of any offline algorithm that has knowledge of all past and future packet arrivals to the performance of our online algorithm) which is asymptotically optimal, and (b) EAR achieves a lower bound in network lifetime. Extensive experimental results from: (a) 82 node Motelab sensor network testbed [2] and (b) varying size network (20-100) in sensor network simulator TOSSIM, validate that EAR outperforms the existing methods both in terms of network performance (network lifetime, network energy consumption) and application performance (low latency, desired throughput) for an energy-constrained sensor network.