Physiological responses to heat strain: A study on personal monitoring for young workers

Heart rate, increased body-core temperature and sweating are the physiological responses to heat stress and they are collectively known as physiological strain. Our goal was to study levels of physiological strain in young farm workers aged 15–21 y. We also verified that heart rate is the response that exceeds threshold limits earliest as seen in previous studies. Personal monitoring for heat-strain measures directly physiological strain as it occurs and gives further information about each worker's state. When estimating levels of physiological strain, certain limits concerning heart rate were adjusted considering the young ages of the workers studied.     

A non-invasive device to continuously determine heat strain in humans

Heat stroke remains a very dangerous, potentially lethal illness in humans. The Physiological Strain Index (PSI), originally based on heart rate and rectal temperature recordings in humans, describes heat strain in quantitative terms. The objective of our study was to establish whether the rectal temperature recordings serving to determine the PSI could be replaced by a non-invasive skin temperature sensor combined with a heat flux sensor (Double Sensor) attached to the inside of a helmet. We assumed (i) that the difference between the recordings by the device under test and the rectal temperature should be less than ±1.0 °C for ±2 S.D. at 10, 25, and 40 °C ambient temperature, and (ii) that the temperature predictions based on the Double Sensor temperature should differ by less than 1 PSI score from the calculations based on recordings of the rectal temperature. Twenty male subjects participated in the study. Rectal, nasopharyngeal, and skin temperatures, heat flux, and cardiovascular data were collected continuously during different experimental setups at ambient temperatures of 10, 25, and 40 °C. Depending on the protocols, the exercise intensities varied from 25% to 55% of the individual VO_2max. A comparison of the recordings obtained from the device under test with those of the rectal temperature revealed that (i) the recordings of the Double Sensor differed by −0.16 to 0.1 °C from the mean rectal temperature, (ii) the concordance correlation coefficients (CCC) during all work and rest periods rose with rising ambient temperatures (all work periods: 10 °C: 0.49; 25 °C: 0.69; 40 °C: 0.75; all rest periods: 10 °C: 0.39; 25 °C: 0.81; 40 °C: 0.74), and that (iii) the Double Sensor in the helmet showed that during all rest periods and in all ambient conditions, the temperature dropped much more quickly than what was recorded when taking the rectal temperature (p<0.01). When we compared the PSI values based on the rectal temperature recordings to those determined by the Double Sensor, it was found that (i) the PSI based on the Double Sensor recordings differed by −0.27 to 0.17 from the mean PSI established by rectal temperature recordings. Furthermore, the CCC for the PSI rose during all work periods (10 °C: 0.81, 25 °C: 0.93, 40 °C: 0.87) and rest periods (10 °C: 0.68; 25 °C: 0.93; 40 °C: 0.79). In conclusion, under warm/hot environmental conditions the device under test provided a reliable method of assessing the PSI in operational environments to improve physiological situational awareness and safety in action. However, there are some limitations that reduce the device's performance in cold environments; these need to be investigated further.     

Comparison of heat strain recovery in different anti-heat stress clothing ensembles after work to exhaustion

A hot environment combined with physically demanding tasks can subject workers to a higher risk of heat stress. A series of regulations and guidelines have been proposed to design appropriate anti-heat stress work uniform to reduce body heat strain. The present study aimed to examine heat strain recovery in different anti-heat stress clothing ensembles after work to exhaustion in the heat. 10 healthy males performed intermittent treadmill running/walking to exhaustion, followed by 30 min passive recovery sitting in a climatic chamber, which simulated the hot and humid outdoor environment (34 °C temperature, 60% relative humidity, 0.3 m/s air velocity, and 450 W/m² solar radiation). The participants took part in five wear trials in counter-balanced order, including Sportswear, CIC Uniform, NEW Uniform, ICEBANK Cooling Vest, and NEW Cooling Vest, which have different levels of cooling capacity. Core temperature, skin temperature, heart rate, sweat loss, ratings of perceived exertion, and thermal sensations were measured throughout the entire heat exposure period. Physiological heat strain indices, including the physiological strain index (PhSI) and the perceptual strain index (PeSI), were used as a yardstick to quantify and compare the rate of recovery. Significantly lower physiological strain was observed in the newly developed NEW Uniform and NEW Cooling Vest groups compared with the commonly worn CIC Uniform group during recovery. At the end of the recovery period, participants in NEW Cooling Vest achieved the highest recovery (42.18% in PhSI and 81.08% in PeSI), followed by ICEBANK Cooling Vest, Sportswear, NEW Uniform, and CIC Uniform. The cooling capacity of anti-heat stress clothing ensembles and the recovery time significantly affect the rate of recovery in PhSI and PeSI, which may benefit the industry by formulating the appropriate work–rest schedule by considering the clothing effect.     

Evaluation of selection index: application to the choice of an indirect multitrait selection index for soybean breeding

Summary Selection indices can be used to predict one trait from information available on several traits in order to improve the prediction accuracy. Plant or animal breeders are interested in selecting only the best individuals, and need to compare the efficiency of different trait combinations in order to choose the index ensuring the best prediction quality for individual values. As the usual tools for index evaluation do not remain unbiased in all cases, we propose a robust way of evaluation by means of an estimator of the mean-square error of prediction (EMSEP). This estimator remains valid even when parameters are not known, as usually assumed, but are estimated. EMSEP is applied to the choice of an indirect multitrait selection index at the F₅ generation of a classical breeding scheme for soybeans. Best predictions for precocity are obtained by means of indices using only part of the available information.     

Physical modelling of globe and natural wet bulb temperatures to predict WBGT heat stress index in outdoor environments

The present paper describes a physical model that estimates the globe and the natural wet bulb temperatures from the main parameters generally recorded at meteorological weather stations, in order to predict the wet bulb globe temperature (WBGT) heat stress index for outdoor environments. The model is supported by a thermal analysis of the globe and the natural wet bulb temperature sensors. The results of simultaneous measurements of the WBGT and climatological parameters (solar radiation, wind velocity, humidity, etc.) are presented and used to validate the model. The final comparison between calculated and measured values shows a good agreement with the experimental data, with a maximum absolute deviation of 2.8% for the globe temperature and 2.6% for the natural wet bulb temperature and the WBGT index. The model is applied to the design reference year for Coimbra, Portugal, in order to illustrate its preventative capabilities from a practical point of view. The results clearly show that during the summer there is a critical daily period (1200–1600 hours, local standard time) during which people working outdoors should not be allowed to perform their normal activities.     

An index based on silvicultural knowledge for tree stability assessment and improved ecological function in urban ecosystems

Trees in the city not only have an ornamental function but also a role in improving the ecological function in urban ecosystems that has been substantially disturbed by human activities such as environmental pollution. Today the ecological role of urban greenery is clearer than ever and is included in the new scientific field of ecological engineering, which is the design of sustainable ecosystems that integrate human society with its natural environment for the benefit of both. Trees in an urban environment show many difficulties in surviving in it because the ecological conditions that exist in the cities are worse than these of the nature. One of these seems to be the heavy wind loads. But even though rough surfaces slow down the wind speed, tall buildings can cause wind tunnel effects that stress a tree as much or even more than if it was positioned in an exposed, unprotected site. An urban tree must be able to endure all the damages and loads from the wind throughout its life. The ability of a tree to withstand wind loads of gale forces depends on its shape and its dimensions. The objective of this paper is the evaluation of tree stability based on the aboveground silvicultural characteristics in order to create an empirical index which can correlate tree stability with these features. Silvicultural characteristics that play the greatest role on tree stability are crown ratio (CR), crown asymmetry index (CAI), and tree height (H). Consequently, tree stability index (TSI) is formed by them. According to TSI values, tree stability was classified in three categories (classes): high, moderate and crucial stability. The limits of the transition from one class to another, as the classes themselves are depended on the number of variables that represent silvicultural characteristics.     

Land use impact assessment in the construction sector: an analysis of LCIA models and case study application

Purpose

Land use is a potentially important impact category in life cycle assessment (LCA) studies of buildings. Three research questions are addressed in this paper: Is land use a decisive factor in the environmental impact of buildings?; Is it important to include the primary land use of buildings in the assessment?; and How does the environmental performance of solid structure and timber frame dwellings differ when assessed by distinct available models for quantifying land use impacts?

Methods

This paper compares several operational land use impact assessment models, which are subsequently implemented in an LCA case study comparing a building constructed using timber frame versus a solid structure. Different models were used for addressing the different research questions.

Results and discussion

The results reveal that contrasting decisions may be supported by LCA study results, depending on whether or not and how land use is included in the assessment. The analysis also highlights the need to include the building land footprint in the assessment and to better distinguish building locations in current land use impact assessment models.

Conclusions

Selecting land use assessment models that are most appropriate to the goals of the study is recommended as different models assess different environmental issues related to land use. In general, the combination of two land use assessment methods for buildings is recommended, i.e. soil organic matter (SOM) of Milà i Canals and Eco-indicator 99.     

Bioclimatic characterisation of an urban area: a case study in Bologna (Italy)

Summer bioclimatic discomfort is a significant public health problem. Bioclimatic characterisations of populations living in urban areas are usually very poor, although the risks are relatively higher in cities because of the phenomenon known as the “urban heat island”. We compared airport, rural, and urban bioclimatic conditions in terms of apparent temperature, Thom index, and temperature alone in several sites within a radius of approximately 25 km from the city of Bologna (Italy). The comparison between meteorological monitoring stations within and near the urban area showed the large impact of the urban heat island effect. Nighttime data showed the largest differences among the investigated sites. Minimum apparent temperatures at rural stations were about 3.5°C lower than the urban 30 m reference station, and 6°C lower than the 2 m urban site. The 2 m apparent temperature values within the urban area were several degrees higher (typically 2°C) than those taken above the roof, both for minimum and maximum values. Temporal trends in the different sites were highly correlated (generally above 0.90), but regression residuals were sometimes quite large. Finally, epidemiological implications are briefly addressed.     

特大型城市生态文明建设评价指标体系及应用——以武汉市为例

特大型城市是我国社会、经济、文化和人口的中心,也是我国资源环境问题最为突出的地方之一。由于特大型城市与中小城市资源环境问题存在差异,特大型城市之间生态环境问题和生态文明建设的状态也存在相似之处,建立反映特大型城市资源环境问题特征的生态文明评价指标体系,依据评价结论,指导特大型生态文明建设十分必要。以服务于特大型城市生态文明建设为目标,在对特大型城市发展状态和特大型城市资源环境问题与社会经济发展突出矛盾分析的基础上,建立了包括有生态环境健康度、资源环境消耗强度、面源污染治理效率和居民生活宜居度等4个方面,共20个指标的特大型城市生态文明评价指标体系,并以各个指标对应的国家标准、政策和规划要求,以及相关研究确立的指标发展目标为依据,对武汉市2006—2011年生态文明建设完成情况进行了评价。依据评价结果,指出武汉市要从以下方面加强生态文明建设:一要控制空气中可吸入颗粒物含量,降低大气中硫化物含量,控制污水排放规模和噪音污染,循环利用废水资源;二要实施总量和强度"双控"政策,显著降低单位GDP的能耗、废气排放量和工业固体排放量;三要提高城市生活污水和生活垃圾的治理能力,循环利用可再生的城市生活"矿产";四要提高森林覆盖率和建城区绿化率,降低人口密度,解决城市住房和交通拥挤问题。     

Cooling therapy upregulates protein C activation in heat stressed rats: An experimental study

Protein C (PC) pathway homeostasis is implicated in heat stress (HS). This study determines whether cooling could improve the PC pathway in HS. Fifty-six anesthetized rats were warmed to achieve HS (rectal temperature [Tr] 42°C). These rats were divided into seven groups: (a) control group:sacrifice immediately 15 min after HS; (b) HS+I:sacrifice immediately after 15 min ice-water treatment or (c) 3 hr after HS; (d) HS+C:sacrifice immediately after 15-min cold-water treatment or (e) 3 hr after HS; (f) HS: sacrifice immediately 15 min after HS or (g) 3 hr after HS. Plasma PC, activated protein C (APC), and soluble thrombomodulin (sTM) levels were tested at both time points. After cooling, Tr in the HS+I and HS+C groups significantly decreased, when compared with the HS group, and Tr was significantly lower in the HS+I group than in the HS+C group ( p < 0.05). Furthermore, sTM levels were highest in the HS group among the groups at both time points. Plasma PC and APC levels increased after HS. In the HS+I and HS+C groups, plasma APC levels and the APC/PC ratio significantly increased at both time points. The proportions were significantly higher in the HS+I group than in the HS+C group, and there was no significant increase in APC/PC ratio in the HS group. Cooling exerts an anticoagulant effect following HS by increasing APC levels. Ice-water blanket therapy is more effective than cold-water blanket therapy in increasing APC levels.     

Development and application of an integrated sustainability index for small-holder dairy farms in Rajasthan,India

In agrarian economy of developing nations like India, smallholder dairy production is an important enterprise and its sustainability is vital for ensuring livelihood and nutritional security to the masses. Studies on methodological aspects of farm sustainability at micro-level are limited, either confined to a particular dimension of sustainability or based on complex data requirement which is not feasible to obtain in the context of smallholder dairy farms. This study has developed a multi-attribute farm level sustainability assessment method encompassing economic, social and ecological dimensions of sustainability and has applied it to assess the sustainability of dairy farming in north-western part of India. Based on data from 120 dairy farms located in rural area of Jaipur district from the state of Rajasthan, the study computed the composite Sustainable Dairy Farming Index (SDFI). The overall substantiality status of the smallholder dairy farms in the study area was not encouraging, implying that it may not be viable for future generation to take up the enterprise. Among the three dimensions of sustainability, the average scores of ecological dimension were highest followed by the economic and social sustainability scores. Some of the core attributes like feed productivity, management of animal genetic potential and gender equality are particularly weak aspects of the dairy production system in India. The direct relationship of economic sustainability with herd size suggests for farmers with very small herds (one to two) animals, increasing the number of dairy animals to about five to six, would be a good strategy to economize on input costs and generate more marketed surplus of milk.     

Parental investment in an anadromous population of threespine sticklebacks: An experimental study

Summary Two previously published field studies of threespine sticklebacks conducted to test predictions of parental investment (PI) theory yielded different conclusions about how males invest in their young. Males of a freshwater population invested more in older/larger broods whereas environmental factors played no role in PI decisions. In contrast, males of an anadromous population adjusted levels of PI in response to environmental factors rather than brood characteristics. The current laboratory study attempts to determine possible reasons for the discrepancy between these two studies. We addressed the following questions. Do males invest more in larger/older broods? Do environmental factors affect levels of parental investment? Males were more aggressive (a measure of PI) in defending eggs than empty nests and free-swimming fry. However, aggression was similar for different-aged eggs and different-aged fry. Moreover, when we manipulated brood sizes (fry), males did not change their level of investment. Males increased their level of aggressive defence in response to a rise in water level, indicating that they can adjust their level of investment in response to changes in environmental conditions that affect brood survival.     

A new index for assessing heavy metals contamination in sediments: A case study

In this study, heavy metals contamination in surface sediments of northwest Persian Gulf was investigated and a new index was formulated for assessing severity of heavy metal pollution in aquatic environments. The surface sediment samples were collected from 45 stations. The concentrations of 8 metals (Fe, Cu, Zn, Cr, Ni, Pb, Cd and V) were analyzed. According to the results of potential ecological risk index (RI), pollution load index (PLI) and modified degree of contamination (mCD), based on the average shale, considerable and intense pollution of heavy metals in sediments of study area was not observed. Based on the sediments quality guidelines the concentration of Ni at whole study area has frequently adverse biological effect on aquatic organisms. The mean effects range-median quotient indicated that surface sediments in the vicinity of petrochemical zone and Bahrekan pier with 49% probability of toxicity can be risky for the biota. The Consequence of the cluster analysis and principal component analysis/factor analysis indicated that Fe, Cu, Zn and Cr are mainly originated from natural sources and Ni, Pb, Cd and V are mostly derived from anthropogenic sources. Results of introduced index in this research (Contamination Severity Index) demonstrated that pollution of heavy metals in sediments at several sites is very intense. Assessment of results illustrated that proposed index is more reliable and logical compared with other investigated indices for evaluating heavy metals pollution in sediments of aquatic environments.     

基于浮游植物生物完整性指数的湖泊生态系统评价——以2012年冬季太湖为例

依据2012年12月对太湖29个样点和同一地理区划4个湖、库的浮游植物和环境变量的监测结果,应用生物完整性理论和方法,构建冬季太湖浮游植物生物完整性指数,评价冬季太湖水生态健康质量。采用干扰程度最小系统法定义筛选确定参照点,对51个候选参数进行分布范围筛选、判别能力分析、参数间相关性分析,获得了太湖枯水期P-IBI指数的6个构成参数:总分类单元数、硅藻门分类单元%、细胞Simpson指数、细胞密度、硅藻门细胞密度%和绿藻门个体密度%。采用比值法统一各参数的量纲,累加后得到枯水期太湖P-IBI分值,并划分健康评价标准。应用P-IBI对冬季太湖水生态进行评价,8个参照点中1个点位评价结果为健康其余7个为亚健康;25个受损点中,2个点位为亚健康,9个点位为一般,12个点位为差,2个点位为极差。太湖总体受到了不同程度的人为干扰,东太湖湖区水生态状况最好,评价结果多为亚健康或一般;竺山湖、贡湖、东部沿岸和西部沿岸次之;南部沿岸和湖心区最差,湖心区有2个点位评价结果为极差。与冬季太湖P-IBI指数显著相关的水化学因子是氨氮和总磷含量。     

Instrumental test to estimate a model of forecast yield: a non-parametric application to the pollen index in South Italy

A statistical test is described to verify the characteristics of the biological information contained in the dynamics of the flowering process. The test focuses on interactions between the pollen index and climatic variables to investigate if the biological indicator can synthesise the information of the pre-flowering phases. The multiple-regression model is built upon two pre-flowering climate macro-indicators extracted by Principal Component Analysis (PCA) and the optimised pollen index is obtained by non-parametric estimation. The empirical analysis is applied to 15 stations located in southern Italy in regions that have a longstanding tradition of olive production. Using the variance explained, we find that an optimised pollen index is fairly well predicted by the pre-flowering climatic data. We conclude that the optimised pollen index makes more parsimonious the modelling for predicting olive production.     

Integration of host strain bioengineering and bioprocess development using ultra‐scale down studies to select the optimum combination: An antibody fragment primary recovery case study

An ultra scale‐down primary recovery sequence was established for a platform E. coli Fab production process. It was used to evaluate the process robustness of various bioengineered strains. Centrifugal discharge in the initial dewatering stage was determined to be the major cause of cell breakage. The ability of cells to resist breakage was dependant on a combination of factors including host strain, vector, and fermentation strategy. Periplasmic extraction studies were conducted in shake flasks and it was demonstrated that key performance parameters such as Fab titre and nucleic acid concentrations were mimicked. The shake flask system also captured particle aggregation effects seen in a large scale stirred vessel, reproducing the fine particle size distribution that impacts the final centrifugal clarification stage. The use of scale‐down primary recovery process sequences can be used to screen a larger number of engineered strains. This can lead to closer integration with and better feedback between strain development, fermentation development, and primary recovery studies. Biotechnol. Bioeng. 2014;111: 1971–1981. © 2014 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.