Development of outdoor thermal index indicating universal and separate effects on human thermal comfort

The purpose of this study is to propose a new outdoor thermal index that simultaneously indicates universal and separate effects. The value indicating universal effect in this index consists of the summation of air temperature and the effective temperature differences by air velocity, longwave radiation, solar radiation, and humidity. This paper describes the theoretical construction of this newly derived index to compare with previous indices. The calculations of the new index are demonstrated using the observed data in order to explicitly indicate the specific features of the new index.     

Toward an energy budget model of photosynthesis predicting world productivity

In order to provide an initial estimate of the probable potential (no lack of soil water, fertilizer, pest and disease controls, advanced cultivation techniques, etc.) agricultural and primary productive ceilings of this planet, a series of deductive models of optimum net photosynthesis is constructed. The concern is with the generalized global trends of productivities representing many types of plants. Because a worldwide treatment of productivity is preferred at this time, a relatively simple, basic model had to be utilized in order to stay within reasonable limits of financial contraints. The findings presented in the body of the text thus represent a tentative economic answer to a pressing question of mankind.Four models have been developed: 1 for a high-efficiency C₄ plant, 2 for a C₃ type agricultural crop, 3 for a broadleaf woody species and 4 for a needleleaf species. The prediction of the leaf temperature is considered the crux of the testing of the energy budget portion of the models.     

Part B: Revisions to the COMFA outdoor thermal comfort model for application to subjects performing physical activity

This study assessed the performance of the COMFA outdoor thermal comfort model on subjects performing moderate to vigorous physical activity. Field tests were conducted on 27 subjects performing 30 min of steady-state activity (walking, running, and cycling) in an outdoor environment. The predicted COMFA budgets were compared to the actual thermal sensation (ATS) votes provided by participants during each 5-min interval. The results revealed a normal distribution in the subjects’ ATS votes, with 82% of votes received in categories 0 (neutral) to +2 (warm). The ATS votes were significantly dependent upon sex, air temperature, short and long-wave radiation, wind speed, and metabolic activity rate. There was a significant positive correlation between the ATS and predicted budgets (Spearman’s rho = 0.574, P < 0.01). However, the predicted budgets did not display a normal distribution, and the model produced erroneous estimates of the heat and moisture exchange between the human body and the ambient environment in 6% of the cases.     

Part A: Assessing the performance of the COMFA outdoor thermal comfort model on subjects performing physical activity

This study assessed the performance of the COMFA outdoor thermal comfort model on subjects performing moderate to vigorous physical activity. Field tests were conducted on 27 subjects performing 30 min of steady-state activity (walking, running, and cycling) in an outdoor environment. The predicted COMFA budgets were compared to the actual thermal sensation (ATS) votes provided by participants during each 5-min interval. The results revealed a normal distribution in the subjects’ ATS votes, with 82% of votes received in categories 0 (neutral) to +2 (warm). The ATS votes were significantly dependent upon sex, air temperature, short and long-wave radiation, wind speed, and metabolic activity rate. There was a significant positive correlation between the ATS and predicted budgets (Spearman’s rho?=?0.574, P?<?0.01). However, the predicted budgets did not display a normal distribution, and the model produced erroneous estimates of the heat and moisture exchange between the human body and the ambient environment in 6% of the cases.     

Diel aspects of the thermal structure and energy budget of a small English lake

SUMMARY. The did response of the thermal structure of Esthwaite Water to prevailing meteorological conditions was analysed for seven selected days, covering different phases of stratification. Meteorological measurements were combined with published empirical relations to compute 24-h thermal energy budgets for 2 days. Amplitudes of diel changes were controlled by the seasonal phase of stratification and the magnitude of incident solar radiation. Heat storage usually followed a sinusoidal curve with a minimum during the night and early morning and a maximum during the late afternoon. Wind-induced turbulent mixing, and vertical circulation induced by nocturnal cooling of the surface water through evaporative and conductive processes, also modified depth-time trends in thermal structure.
The budget accounted for almost all the thermal energy exchanges of the lake. Possible sources of a slight imbalance are considered. Although there was a positive daily surplus of net radiation, it may not always imply heat gain by the lake as it may be counter-balanced by heat losses through fluxes of latent and sensible heat, Net back-radiation was a major component of daily heat loss. The combined latent and sensible heat fluxes also accounted fora high proportion of heat loss to the atmosphere. Net flow of sensible heat to the lake was small but not always inappreciable. Net daily heat storage represented 26% (9 May) and 13% (17 June) of solar radiation Input. Advected energy due to lake inflow and outflow was negligible. Qualitative comparisons are made with long-term (seasonal and annual) energy budgets and heat fluxes.     

Effect of fee-for-service air-conditioning management in balancing thermal comfort and energy usage

Balancing thermal comfort with the requirement of energy conservation presents a challenge in hot and humid areas where air-conditioning (AC) is frequently used in cooling indoor air. A field survey was conducted in Taiwan to demonstrate the adaptive behaviors of occupants in relation to the use of fans and AC in a school building employing mixed-mode ventilation where AC use was managed under a fee-for-service mechanism. The patterns of using windows, fans, and AC as well as the perceptions of students toward the thermal environment were examined. The results of thermal perception evaluation in relation to the indoor thermal conditions were compared to the levels of thermal comfort predicted by the adaptive models described in the American Society of Heating, Refrigerating, and Air-Conditioning Engineers Standard 55 and EN 15251 and to that of a local model for evaluating thermal adaption in naturally ventilated buildings. A thermal comfort-driven adaptive behavior model was established to illustrate the probability of fans/AC use at specific temperature and compared to the temperature threshold approach to illustrate the potential energy saving the fee-for-service mechanism provided. The findings of this study may be applied as a reference for regulating the operation of AC in school buildings of subtropical regions.     

Thermal comfort modelling of body temperature and psychological variations of a human exercising in an outdoor environment

Human thermal comfort assessments pertaining to exercise while in outdoor environments can improve urban and recreational planning. The current study applied a simple four-segment skin temperature approach to the COMFA (COMfort FormulA) outdoor energy balance model. Comparative results of measured mean skin temperature ( [`(T)]\nolimits<sub>Msk</sub> \mathop{{\bar{T}}}\nolimits_{{Msk}} ) with predicted [`(T)]\nolimits_sk \mathop{{\bar{T}}}\nolimits_{{sk}} indicate that the model accurately predicted [`(T)]\nolimits<sub>sk</sub> \mathop{{\bar{T}}}\nolimits_{{sk}} , showing significantly strong agreement (r = 0.859, P < 0.01) during outdoor exercise (cycling and running). The combined 5-min mean variation of the [`(T)]\nolimits_sk \mathop{{\bar{T}}}\nolimits_{{sk}} RMSE was 1.5°C, with separate cycling and running giving RMSE of 1.4°C and 1.6°C, respectively, and no significant difference in residuals. Subjects’ actual thermal sensation (ATS) votes displayed significant strong rank correlation with budget scores calculated using both measured and predicted [`(T)]\nolimits<sub>sk</sub> \mathop{{\bar{T}}}\nolimits_{{sk}} (r <sub>s</sub>  = 0.507 and 0.517, respectively, P < 0.01). These results show improved predictive strength of ATS of subjects as compared to the original and updated COMFA models. This psychological improvement, plus [`(T)]\nolimits_sk \mathop{{\bar{T}}}\nolimits_{{sk}} and T _c validations, enables better application to a variety of outdoor spaces. This model can be used in future research studying linkages between thermal discomfort, subsequent decreases in physical activity, and negative health trends.     

Understanding the low breeding success in Greater Rheas populations through an energy budget model

We propose an individual-based energy budget model of the Greater Rhea (Rhea americana) with the purpose of analyzing the population's recruitment. One remarkable characteristic of this species is that female rheas lay eggs communally and males incubate the eggs and care for the chicks without the assistance of females.The model is based on a system of equations daily updating the weight of each bird as a function of its ingestion rate and the energetic cost of its activity pattern. Ingestion rate is calculated from field experiments. Daily energetic costs are estimated from activity patterns observed in the field, taking into account gender and factors that influence behavior (e.g., photoperiod, season). Concatenating daily model outputs, the weight dynamics of an individual can be calculated over any given period of time.The possible factors that affect the successful breeding of the Greater Rhea and therefore population growth are analyzed using the model. Different reproductive strategies for each gender are analyzed and the minimal body weight, and thus energy reserves, that an individual needs to achieve for ensuring reproductive success is determined. Model outputs show that the reproductive success of males depends strongly on their body weight while females exhibit low nutritional requirements for producing eggs. An analysis of model outputs allows inferring that males in wild populations might not be able to breed in consecutive years but could successfully breed every other year. They also allow estimating the incidence that food availability has on population growth. Management strategies that are easy to implement in extensive and semi-extensive farms may allow obtaining male individuals capable of breeding every year.     

Estimating crop yield using a satellite-based light use efficiency model

Satellite-based techniques that provide temporally and spatially continuous information over vegetated surfaces have become increasingly important in monitoring the global agriculture yield. In this study, we examine the performance of a light use efficiency model (EC-LUE) for simulating the gross primary production (GPP) and yield of crops. The EC-LUE model can explain on average approximately 90% of the variability in GPP for 36 FLUXNET sites globally. The results indicate that a universal set of parameters, independent of crop species (except for C4 crops), can be adopted in the EC-LUE model for simulating crops’ GPP. At both irrigated and rainfed sites, the EC-LUE model exhibits a similar level of performance. However, large errors are found when simulating yield based on crop harvest index. This analysis highlights the need to improve the representation of the harvest index and carbon allocation for improving crop yield estimations from satellite-based methods.     

Optimizing algal biomass production in an outdoor pond: a simulation model

A deterministic simulation model was developed to predict production rates of the marine prymnesiophyteIsochrysis galbana in an outdoor algal mass culture system. The model consists of photoadapation, gross photosynthesis and respiration sections. Actual physiological and biophysical laboratory data, obtained from steady state cultures grown under a wide range of irradiance levels, were used in calculating productivity. The resulting values were used to assess optimal operational parameters to maximize algal biomass production. The model predicted a yearly averaged production rate of 9.7 g C m^?2d^?1, which compared well with field data reported in the literature. The model evaluated the effect of pond depth and chlorophyll concentration on potential production rate in various seasons. The model predicted that a yearly averaged chlorophyll areal density of 0.65 g m^?2 will yield the maximal production rate. Chlorophyll areal density should be seasonally adjusted to give maximal production. This adjustment could be done either by changing pond depth or chlorophyll concentration. The model predicted that under optimal operational conditions, the diurnal respiration losses averaged 35% of gross photosynthesis. The calculated growth rate for maximal productivity ranged between 0.15 and 0.24 d^?1, suggesting an optimal hydraulic retention time of 6.7 and 4.2 d for various seasons.     

Prediction of air temperature for thermal comfort of people using sleeping bags: a review

Six models for determining air temperatures for thermal comfort of people using sleeping bags were reviewed. These models were based on distinctive metabolic rates and mean skin temperatures. All model predictions of air temperatures are low when the insulation values of the sleeping bag are high. Nevertheless, prediction variations are greatest for the sleeping bags with high insulation values, and there is a high risk of hypothermia if an inappropriate sleeping bag is chosen for the intended conditions of use. There is, therefore, a pressing need to validate the models by wear trial and determine which one best reflects ordinary consumer needs.     

A note on the energy budget for an oyster population in a temperate estuary

There are six beds of oysters in the estuary of the Beaulieu River, Hampshire; these correspond to areas of gravel bottom. Between November, 1974 and November, 1975 the population was dominated by large individuals (>5 years) and there was no evidence of significant recruitment during the previous two to three years. During the year the population filtered material with an energy content of 15.95 × 10⁶ kcal; 30.4% of this is estimated to have been rejected as pseudofaeces; of the remainder, which was consumed, 30.7% was passed as faeces, 29.0% was respired and lost as heat, 6.4% was diverted into production of soft tissue and shell organics. and 5.5% was released as gonad output. The remaining 28.4% may be partly accounted for as excreta lost to the population as mucus and dissolved organic matter. Gonad output was proportionally large due to the presence of a high percentage of older individuals; this energy was lost from the population and there was no recruitment.     

Estimating developmental states of tumors and normal tissues using a linear time-ordered model

Background  

Tumor cells are considered to have an aberrant cell state, and some evidence indicates different development states appearing in the tumorigenesis. Embryonic development and stem cell differentiation are ordered processes in which the sequence of events over time is highly conserved. The "cancer attractor" concept integrates normal developmental processes and tumorigenesis into a high-dimensional "cell state space", and provides a reasonable explanation of the relationship between these two biological processes from theoretical viewpoint. However, it is hard to describe such relationship by using existed experimental data; moreover, the measurement of different development states is also difficult.     

Estimating the under-five mortality rate using a bayesian hierarchical time series model

Background

Millennium Development Goal 4 calls for a reduction in the under-five mortality rate by two-thirds between 1990 and 2015, which corresponds to an annual rate of decline of 4.4%. The United Nations Inter-Agency Group for Child Mortality Estimation estimates under-five mortality in every country to measure progress. For the majority of countries, the estimates within a country are based on the assumption of a piece-wise constant rate of decline.

Methods and Findings

This paper proposes an alternative method to estimate under-five mortality, such that the underlying rate of change is allowed to vary smoothly over time using a time series model. Information about the average rate of decline and changes therein is exchanged between countries using a Bayesian hierarchical model. Cross-validation exercises suggest that the proposed model provides credible bounds for the under-five mortality rate that are reasonably well calibrated during the observation period. The alternative estimates suggest smoother trends in under-five mortality and give new insights into changes in the rate of decline within countries.

Conclusions

The proposed model offers an alternative modeling approach for obtaining estimates of under-five mortality which removes the restriction of a piece-wise linear rate of decline and introduces hierarchy to exchange information between countries. The newly proposed estimates of the rate of decline in under-5 mortality and the uncertainty assessments would help to monitor progress towards Millennium Development Goal 4.     

Estimating the population size of an endangered shorebird, the Madagascar plover, using a habitat suitability model

The Madagascar plover Charadrius thoracicus is a shorebird endemic to western Madagascar, currently classified as globally vulnerable. It is restricted to specialized wetland habitats that are increasingly threatened by humans. To inform future conservation measures for this poorly known species, we develop a predictive habitat suitability map and use this map to estimate the size of the Madagascar plover population. We integrate spatially referenced presence-only observations of Madagascar plovers with Landsat data, elevation data and measures of distance to settlements and the coast to produce a habitat suitability model using ecological niche factor analysis. Validation of this model using a receiver operating characteristic plot suggests that it is at least 84% accurate in predicting suitable sites. We then use our estimate of total area of suitable habitat above a critical suitability threshold and data on Madagascar plover density in suitable sites to estimate the total population size to derive a total population estimate of 3100±396 standard error individuals. Finally, we explore the conservation applications of our model.