Daily Temperature Difference Research Articles

Microclimate edge effect in small fragments of temperate forests in the context of climate change

A long-distance edge effect influences structure of species-rich plant communities in temperate forest fragments surrounded by an agricultural landscape in Central Europe. Though the edge effect may be an aggregate of many environmental conditions, the thermal gradient from the forest edge to the forest interior deserves particular attention due to increasing ambient air temperature over the past decades. With regard to ongoing climate change, any reliable information about magnitude and distance of thermal gradients in these forest fragments has become of great importance. Therefore, we carried out seasonal measurements of forest air and soil temperature at a total 40 sites in 14 forest fragments in central Bohemia with areas ranging between 0.3 and 255 ha. In addition, we assessed spatial and vertical air temperature variability at two sites, on both south and north facing slopes. We found that differences in daily mean air temperature in these forest fragments is significantly modified by slope aspect (and/or slope inclination) and distance to the forest edge. A negative monotonic edge-related thermal gradient was apparent up to 100 m towards the forest interior with differences in daily mean air temperatures of about 0.3 °C. The magnitude of this edge thermal gradient is comparable to the effect of slope aspect. In addition to mean air temperature, maximum and minimum daily temperatures as well as mean soil temperature inside forest fragments also showed impacts caused by the edge effect and other environmental conditions (e.g. forest structure, elevation). The edge-related area closer than 100 m from the forest edge represents the majority (78%) of forested land in the study area as well as a considerable part of temperate forests in Central Europe (40%), including less fragmented mountain forests. Hence, the edge alteration of forest microclimate should be taken into serious consideration when planning adaptation measures against the consequences of climate change in Central Europe. The edge influence could be partially mitigated by preventing further forest fragmentation and the adoption of timber harvesting methods that avoid creation of clearings, such as single-tree selection. Even if such forest management measures are implemented in the study area, spatial patterns and gradients of environmental heterogeneity may be gradually reduced in the forest fragments as a result of further exposure to the combined effects of climate change and edge influence.

Reduced thermal variability in cities and its impact on honey bee thermal tolerance.

Urbanization is one of the most significant land cover transformations, and while climate alteration is one of its most cited ecological consequences we have very limited knowledge on its effect on species’ thermal responses. We investigated whether changes in environmental thermal variability caused by urbanization influence thermal tolerance in honey bees (Apis mellifera) in a semi-arid city in central Mexico. Ambient environmental temperature and honey bee thermal tolerance were compared in urban and rural sites. Ambient temperature variability decreased with urbanization due to significantly higher nighttime temperatures in urban compared to rural sites and not from differences in maximum daily temperatures. Honey bee thermal tolerance breadth [critical thermal maxima (CTmax)—critical thermal minima (CTmin)] was narrower for urban bees as a result of differences in cold tolerance, with urban individuals having significantly higher CTmin than rural individuals, and CTmax not differing among urban and rural individuals. Honey bee body size was not correlated to thermal tolerance, and body size did not differ between urban and rural individuals. We found that honey bees’ cold tolerance is modified through acclimation. Our results show that differences in thermal variability along small spatial scales such as urban-rural gradients can influence species’ thermal tolerance breadths.

Air pollution increases the risk of SSNHL: A nested case-control study using meteorological data and national sample cohort data

This study aimed to evaluate the impact of weather conditions and air pollution on the onset of sudden sensorineural hearing loss (SSNHL). The Korean Health Insurance Review and Assessment Service - National Sample Cohort (HIRA-NSC) from 2002 through 2013 was used. A total of 5,200 participants with SSNHL were matched 1:4 for age, sex, income, region of residence, hypertension, diabetes, and dyslipidemia with 20,800 control participants. Meteorological data included daily mean temperature (°C), daily highest temperature (°C), daily lowest temperature (°C), daily temperature difference (°C), relative humidity (%), ambient atmospheric pressure (hPa), pressure, SO2 (ppm), NO2 (ppm), O3 (ppm), CO (ppm), and PM10 (μg/m3) of a mean of 60 days, 30 days, 14 days, 7 days, and 3 days before SSNHL were analyzed. Hourly measurements were taken from 94 places to assess the temperature, humidity, and atmospheric pressure and from 273 places to determine SO2, NO2, O3, CO, and PM10. Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of meteorological data for SSNHL were analyzed using unconditional logistic regression analyses. Subgroup analyses were conducted by age and sex. The mean NO2 and O3 concentrations 14 days before the index date were different in the SSNHL group compared to those in the control group (P < 0.001 for NO2 and P = 0.021 for O3). The adjusted 14-day OR for NO2 (0.1 ppm) exposure was 3.12 in the SSNHL group compared to that in the control group (95% CI = 2.16–4.49, P < 0.001). The increased odds of NO2 exposure for 14 days in the SSNHL group persisted in the age group older than 30 years for both sexes. Other meteorological conditions did not show differences between the SSNHL and control groups. SSNHL was associated with high concentrations of NO2.

Study on indoor thermal environment of rural dwellings in Northwest China in winter

In order to study the status of the indoor thermal environment of the northwest rural dwellings in winter, the thermal performance and the residents’ adaptability are investigated and the indoor and outdoor thermal environment parameters are measured in Zhongwei region of Ningxia, the indoor thermal environment is analyzed and evaluated by the operating temperature. The results show that the northwest rural residents have strong adaptability to the cold indoor thermal environment in winter. In this area, the cold and daily temperature difference in winter is large, but the solar energy is rich, and it has the geographical advantage of developing passive solar building. The thermal performance of existing rural dwellings is poor and the indoor thermal environment is not ideal. It is necessary to enhance the thermal performance of building’s heat collection, thermal storage and enclosure structure.

Sunspace coupling with hyper-insulated buildings: Investigation of the benefits of heat recovery via controlled mechanical ventilation

An experimental study was conducted to examine the energetic and ergonomic impacts of an optimized mechanically controlled ventilation system, implemented on the partition wall between a hyper-insulated test building and the attached sunspace, to overcome most of the inherent limitations of a purely radiative heat transfer in presence of very low thermal transmittance envelope.The system comprised two vented holes (at floor and ceiling level), piloted by a smart controller on the basis of the temperature difference between the two air volumes. The threshold was progressively reduced from 2 °C to 0.5 °C to ameliorate the energy performance without trespassing the comfort boundaries. Calls for extra heating from the active technical system (electric radiators) were thus minimized, regardless of the climatic conditions: the energy consumption (normalized over the indoor-outdoor daily average temperature difference and over the daily mean solar irradiation) decremented by 36% and 66% respectively compared to the 1 °C and 2 °C configurations, which, in turn, exhibited similar performance. The ergonomic penalty due to thermal overshooting was statistically acceptable.The outcomes were compared to those of a previous monitoring run on the same case study, with 20% less glazed surface: the new configuration more than halved the energy expenditure.Finally, the albedo of the surrounding materials was shown to be a key-player: even under extremely cold and overcast conditions, the sunspace temperature rose up to 40 °C when fresh snow layered all around the perimeter. Further investigation could support broadening the spectrum of potentially efficient applications.

Reviewing Theoretical and Numerical Models for PCM-embedded Cementitious Composites

Accumulating solar and/or environmental heat in walls of apartment buildings or houses is a way to level-out daily temperature differences and significantly cut back on energy demands. A possible way to achieve this goal is by developing advanced composites that consist of porous cementitious materials with embedded phase change materials (PCMs) that have the potential to accumulate or liberate heat energy during a chemical phase change from liquid to solid, or vice versa. This paper aims to report the current state of art on numerical and theoretical approaches available in the scientific literature for modelling the thermal behavior and heat accumulation/liberation of PCMs employed in cement-based composites. The work focuses on reviewing numerical tools for modelling phase change problems while emphasizing the so-called Stefan problem, or particularly, on the numerical techniques available for solving it. In this research field, it is the fixed grid method that is the most commonly and practically applied approach. After this, a discussion on the modelling procedures available for schematizing cementitious composites with embedded PCMs is reported.

Comparative studies of patterns of variation of daily temperature differences inside the north wall in Chinese solar greenhouses of three different designs during cold periods

Comparative studies of patterns of variation of daily temperature differences inside the north wall in Chinese solar greenhouses of three different designs during cold periods

Temperature Control Measures and Temperature Stress of Mass Concrete during Construction Period in High-Altitude Regions

The focus on the development of China’s vast hydropower resources has shifted to Tibet and other plateau regions. These areas are high-altitude regions whose basic climatic characteristics are as follows: dry climate, significant differences in daily temperature, and strong solar radiation. If a dam is built under such special climate conditions, specific and strict temperature control and crack prevention measures should be taken. Therefore, this study explores the temperature control standards, as well as temperature control and crack prevention measures, for concrete in high-altitude regions using three-dimensional finite element methods and based on the concrete gravity dam in Tibet in combination with the characteristics of material properties that are disadvantageous to temperature control and crack prevention. The temperature drop process can be optimized in time, and the temperature drop rate can be controlled to prevent excessive scale and temperature drop rates. Moreover, the temperature gradient can be spatially optimized, and thus, the differences in foundation temperatures, upper- and lower-layer temperatures, and internal and external temperatures can also be reduced. The research shows that the recommended temperature control and crack prevention measures can effectively reduce temperature stress. This study has a significant value as a reference for similar projects in high-altitude regions.

The integration of solid-solid phase change material with micro-channel flat plate heat pipe-based BIPV/T

In this paper, the influence of the solid-solid phase change material on the novel micro-channel flat-plate heat-pipe–based building integrated photovoltaic/thermal system has been investigated, which has been expected to store the excess heat, enhance the overall efficiency of the system and maintain the stable photovoltaic temperatures. The proposed system was divided into two parts, i.e. the outdoor part formed by flat-plate glass, photovoltaic panel, micro-channel flat-plate heat pipes, solid-solid phase change material layer and insulated material, and indoor part including the storage tank, water pump and storage batter. The experiments were conducted at the Guangdong University of Technology, China, to investigate the thermal and electrical performance of the proposed system. When the simulated radiation was at 300 W/m2 and water flow rate was at 600 L/h, the maximum average thermal, electrical and overall efficiency were found at 52.9%, 7.9% and 60.8%, respectively, when the xenon lamps were turned on, and the maximum average efficiency of 86.6% were found when the xenon lamps were turned off, indicating the most appropriate working condition of the proposed system due to the thermal storage and release of the solid-solid phase change material during the system operation. Compared with the previous studies of the conventional building integrated photovoltaic/thermal systems, it was found that the overall efficiency of the system averagely increased 5–30% and the daily water temperature difference of the system averagely increased 1.8–10.5℃, indicating that the solid-solid phase change material can significantly increase the thermal efficiency of the system. Practical application The proposed micro-channel-flat-plate-heat pipe based BIPV/T (MCFPHP-BIPV/T) system with SS-PCM will be potentially used in buildings to provide amount of electricity and thermal energy. The generated electricity will be used by the residential electrical devices or connected to the grid, and the thermal energy can be used for hot water, even for space heating and cooling. The proposed building-integrated system can be assisted in realising the targets of energy saving and carbon-emission-reduction in buildings.

Temperature Monitoring of High-Speed Railway Bridges in Mountainous Areas

Solar radiation and temperature can cause the deformation of high-speed railway bridges which has an obvious effect on the position of the rails and thus on passenger comfort, especially when the bridge spans a mountainous area. In this study, the temperatures of a track–bridge system and the deflections of the tall piers belonging to a high-speed railway line in China were monitored for over three years. By adopting extreme value theory and a time-series method, the temperatures and temperature gradients of structural components of the bridge were investigated in relation to time. The results show that the monitored temperatures can be broken down into the uniform temperature and the fluctuation temperature, which cause axial deformation and structural deflection, respectively. A uniform temperature curve was fitted using the Fourier series function and then used to calculate the axial deformations for different components of the track–bridge system over a one-year period. Additionally, the extreme temperature differences estimated for a 100-year return period can be used to encapsulate the maximum values of the daily temperature difference. Thus, the proposed temperature model can effectively estimate the structure’s temperature-induced deformations.

On the performance of a baffled glazed-bladed entrance solar air heater

The performance of a baffled glazed-bladed entrance air heater (BGBSAH) was experimentally investigated and compared with a conventional one at the same operating conditions. The solar air heater was modified at the entrance region. This region was covered with a glass coverinstead of a steel one to increase the heating area exposed to solar radiation (IR). In addition, the entrance region was boosted by guide blades to affirm a good air distribution inside the heater. Baffles attached to nineteen longitudinal fins were fixed inside the heater. These baffles were used to increase the heat transfer area, the length of air flow path, and the heat capacity of SAH via increasing the mass of the material. Three various numbers of baffles (170, 410 and 800) were used. Moreover, four values of air flow rates ranged from 0.013 to 0.04 kg/s were investigated. The results showed that, at the same mass flow rate, the performance of SAH was directly proportional to the baffles number. In addition, the results revealed that the maximum daily temperature difference obtained from the BGBSAH with 800 baffles was 51.9 °C compared to 22.7 °C for the conventional one at 0.013 kg/s. Besides, the daily efficiency was improved by 29.91–51.69% in case of BGBSAH with 800 baffles compared to the conventional one. For conventional SAH the average cost per kW is 0.0146 $ while for BGBSAH are 0.00733, 0.00787 and 0.0084 $ for 800, 410 and 170 baffles, respectively.

Analysis of different combinations of meteorological parameters in predicting the horizontal global solar radiation with ANN approach: A case study

Solar energy is a clean renewable energy source and availability of solar resources at a particular location depends on the local meteorological parameters. In the present study, prediction models using artificial neural networks (ANN) are developed by varying the meteorological parameters from one to six. A two year database of daily global solar radiation (GSR), daily minimum temperature (Tmin), daily maximum temperature (Tmax), difference of daily maximum and minimum temperature (DT), sunshine hours (S), theoretical sunshine hours (So) and extraterrestrial radiation (Ho) have been used to train the ANN. Six ANN models are developed (ANN-1 to ANN-6) with 32 possible combinations of inputs and are used to train the network to identify the best combination of inputs to estimate the monthly mean daily GSR accurately. All the models are validated and the performance of the models are analyzed by using the statistical tools.Out of the six ANN models with all the possible combination of input variables, ANN-2 and ANN-3 have given best prediction with the combinations of [DT, Ho] and [DT, Ho, So] respectively. The statistical tool Relative Root Mean Square Error (RRMSE) showed the least value of 3.96% with [DT, Ho] inputs. The ANN-1 trained with calculated approximate sunshine hours (Sa) has also shown high prediction accuracy. Sunshine based model and temperature based model are validated with ANN-1, ANN-2 and ANN-3 architectures. Results showed that the developed ANN models outperform the considered empirical models. The combination of [So, Ho] has produced excellent estimation, which are theoretical parameters and does not require any measured meteorological parameters. Superior performance is observed with less number of inputs which are readily available for any location.

Correlation between equine colic and weather changes

The objective of this study is to evaluate the possible correlation between relative humidity/temperature change and equine colic in a specific region of Northern Greece. A study population of 823 adult horses stabled in a 40-km-radius around Thessaloniki, Northern Greece were included in this study; a total of 245 horses, suffering from several types of colic between January 2010 and December 2012 were selected. Metereological data, including temperature (oC) and relative humidity (%) were obtained as 3-hour periodic measurements by the Hellenic National Metereological Service. Statistical analysis was performed using Spearman correlation coefficients in order to assess the relationship between temperature changes, relative humidity changes and equine colic. A positive correlation between temperature change and equine colic was detected during March for the whole 3-year period, while positive correlation was presented during several months of late spring and late fall in specific years. No correlation between changes in relative humidity values and colic was shown. Moreover, a negative correlation between relative humidity and temperature, for temperatures &gt;10°C (rho=-0.568, p&lt;0.01) was found, while, a positive correlation (rho=0.650, p&lt;0.01) between daily temperature difference (ΔT) and relative humidity difference was detected. In this study, abrupt temperature change was proven as a significant risk factor in the development of colic during late spring and fall, in Northern Greece, requiring more vigilant horse owners and equine practitioners. These results suggest that in the future it may be possible to modulate management taking into consideration the current weather conditions, in order to prevent colic episodes.

秸秆覆盖量对红壤旱地棉花生长及土壤温度的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 秸秆覆盖量对红壤旱地棉花生长及土壤温度的影响 DOI: 10.5846/stxb201610272194 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 江西省研究生创新专项资助项目（YC2016-B035）；国家重点研发计划（2016YFD0300209） Effects of straw mulching amount on cotton growth and soil temperature in red soil drylands Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为探索红壤旱地较适宜的秸秆覆盖量，采取随机区组大田试验，设置4个秸秆覆盖水平：S1为0 kg/hm2、S2为4375 kg/hm2，S3为8750 kg/hm2和S4为13125 kg/hm2，研究秸秆覆盖量对红壤旱地棉花产量、出苗率、株高、叶绿素含量和土壤温度的影响。结果表明：秸秆覆盖处理（S2-S4）较不覆盖处理（S1），一是提高棉花出苗率，差异极显著（P<0.01）；二是影响棉花生育后期的主茎生长速度，以S4效果最好；三是可明显促进棉花叶绿素含量的增加，且以S3和S4的效果较好；四是调节土壤温度，在8：00和20：00提高土壤温度，在14：00降低土壤温度，且日均地温变化幅度小，但随着土层的加深，调温作用逐渐减弱，整个覆盖期内日均温的差值与土壤深度具有高度的相关性；五是显著增加棉花产量，S2、S3和S4分别比S1高11.4%、35.9%和37.7%，差异极显著（P<0.01），且随着覆盖量的增加，增产效果逐渐提高。综合来看，秸秆覆盖在改善红壤旱地棉花产量、出苗率、株高、叶绿素含量、调节土壤温度方面发挥着重要作用，且以8750-13125 kg/hm2效果显著，是红壤旱地值得推广的栽培模式。 Abstract:To improve the productivity of cotton fields in red soil drylands, it is necessary to study the yield-limiting factors in these regions, and propose appropriate mitigation measures. Straw mulching is an effective method of straw resource utilization, which could effectively promote the sustainable development of agriculture. To enhance our understanding of the appropriate straw mulching amount in red soil drylands, a randomized block design field experiment was carried out in the Science and Technology Park of Jiangxi Agricultural University (115°55'02.040″E, 28°46'04.476″N, original the Agricultural College Test Station). The effects of the following four straw mulch level treatments were examined:0 kg/hm2 (S1), 4 375 kg/hm2 (S2), 8 750 kg/hm2 (S3), and 13 125 kg/hm2 (S4). The present study mainly investigated the yield, emergence rate, plant height, and chlorophyll content of cotton, and also soil temperature. The following results were obtained. (1) Straw mulching treatments increased cotton seedling emergence by 21.5%-28.1%. The difference between mulching treatments (S2-S4) and the non-mulching treatment (S1) was significant at P<0.01, although there were no significant differences among the three mulching treatments. (2) Straw mulching treatments affected the main stem growth of cotton at the late stage of growth, with treatment S4 having the best effect. (3) Straw mulching treatments also promoted an increase in chlorophyll content. Chlorophyll content in each growth period increased with an increase in the amount of straw mulching, with treatments S3 and S4 having the best effects. (4) Straw mulching treatments regulated the soil temperature. The soil temperature increased at 08:00 and 20:00, but decreased at 14:00, although the daily temperature range showed only a small variation. The effect of temperature control was weakened gradually in the straw mulching treatments with an increase in soil depth. This effect was highly correlated with daily mean temperature difference and soil depth during the coverage period, and the correlation coefficient reached 0.98 or higher, which aided in predicting the variation in diurnal temperature range of different soil layers. (5) Straw mulching treatments promoted a highly significant (P<0.01) increase in cotton production, with production in treatments S2, S3, and S4 being 11.4%, 35.9%, and 37.7% higher, respectively, than that in the non-mulching treatment (S1). There was also a gradual increase in yield with an increase in the amount of mulching. Collectively, these results indicate that straw mulching can play an important role in improving cotton yield, seedling emergence rate, plant height, and chlorophyll content, and also in regulating soil temperature in red soil drylands. In this regard, straw mulching at 8 750-13 125 kg/hm2 was considerably effective, which would not only be conducive to the production of cotton but could also reduce environmental pollution caused by the burning of straw and improve the utilization of straw resources, and is thus worth popularizing in red soil drylands. However, since the present study was only of a short duration, further long-term studies in red soil drylands are required, particularly with regards to the mechanisms underlying the effects of mulching on the growth of cotton. 参考文献 相似文献 引证文献

A new methodology to extend the validity of the Hargreaves-Samani model to estimate global solar radiation in different climates: Case study Mexico

This work presents a modification to the model proposed by Hargreaves and Samani, based on daily temperature difference, to estimate daily global solar radiation. This is done by analyzing the relation between daily temperature increments and the fitting parameter in the model. Six different climates and four day types have been considered. Day classification was done in accordance to the daily clearness index. The proposed model was validated on a database that comprises 47 stations distributed in Mexico.The proposed methodology to estimate daily solar global radiation is compared against the original Hargreaves model, using fixed reported values for the fitting parameter. The performance of the proposed model is done based on four metrics commonly used. The proposed model reduces the overall errors and bias from the original model, and thus its validity on different climate types is extended. It was obtained a reduction of the RMSE of at least 15% and up to 30%, depending on climate, when compared with the Hargreaves-Samani model. Obtained RMSE are below the mean RMSE reported in literature. Similar improvements were observed with other metrics. In addition, average daily clearness index for each station and their distribution are presented for all stations.

Uncertainty in homogenized daily temperatures and derived indices of extremes illustrated using parallel observations in Canada

ABSTRACTParallel daily temperature observations at site pairs over a 5‐year period at 88 locations across Canada were used to derive and validate adjustments required during homogenization process. The data was first ‘aligned’ for compatible observing times at 12 locations (other locations do not have this problem). Then the homogenization adjustments were obtained using three procedures (Seasonal Bias, Monthly Interpolation and Quantile Matching) and two approaches (using parallel and neighbours observations). The root mean squared error (RMSE) between the daily temperatures of site 1 and site 2, and the percentage of days within 0.5 °C (PD05) between site 1 and site 2 were used to assess the uncertainty in the mean and extreme values, respectively. The instruments were not necessarily collocated as the distance between the two observing sites varied from 0 to 30 km. The results confirm that it is necessary to apply adjustments for known issues first, such as a different observing time. They also show that when a shift between site 1 and site 2 (defined by the annual mean of the daily temperature differences) is small [&lt;0.25 standard deviation (SD)], the adjustments do not reduce the error between site 1 and site 2. When the shift size is between 0.25 and 0.5 SD, the adjustments derived from parallel observations help to reduce the uncertainty. When the shift is large (&gt;0.5 SD), both approaches reduce the error, although the adjustments derived from parallel observations provide better results as compared to those computed from neighbour observations. The results also indicate that Quantile Matching adjustments can provide a better estimate of the adjustments than the other methods evaluated to indices of extreme temperature computed from the adjusted daily values; however, highly correlated neighbours are needed when the adjustments are based on neighbours observations.

Analysis of the onset time of acute aortic dissection and the influence of climate on acute aortic dissection occurrence in Urumqi city: a retrospective study of a single center

To observe the time characteristics of acute aortic dissection (AAD) in Urumqi and its peripheral areas in Xinjiang Uygur autonomous region, and to explore the effect of meteorological conditions on the onset of AAD. Retrospective analysis of the related data of the adult AAD patients diagnosed by imaging examination, and admitted to the First Affiliated Hospital of Xinjiang Medical University from March 2010 to July 2016 was performed. The onset time, the contemporaneous meteorological data, including daily minimum, average, and the highest temperature, daily average air pressure, daily average relative humidity, daily precipitation, daily average wind speed, daily maximum wind speed, and sunshine duration per day were collected. Analysis of concentrated distribution trend of the AAD onset was done by circular distribution statistics. Meteorological conditions were compared between "the AAD day" and "no AAD day". The changes of air temperature 5 days before onset were observed. A total of 379 patients were enrolled, with 307 male and 72 female. The ratio of male to female was 4.19: 1, the average age was 52.27±12.18; and the underlying diseases was hypertension (about 58.05%); the incidence sites were Urumqi and Changji city. (1) The incidence of AAD in Urumqi and its peripheral areas had clear concentrated trend, and the peak period of AAD corresponded to January 1st to 2nd (homogeneity test r = 0.104, r 0.05 = 0.009, P < 0.05). (2) The minimum, mean and maximal atmospheric temperatures on "the AAD day" were lower than "no AAD day" [centigrade: 4.10 (-9.55, 14.60) vs. 7.75 (-6.70, 16.20), 14.10 (-1.50, 25.00) vs. 17.50 (0.60, 26.78), 8.50 (-6.22, 19.45) vs. 12.10 (-3.60, 20.90), all P < 0.05], sunshine duration was significantly shorter than "no AAD day" [hours: 8.50 (4.60, 10.70) vs. 8.90 (5.50, 11.50), P < 0.01], and atmospheric pressure were higher than "no AAD day" [kPa: 91.24 (90.66, 91.75) vs. 91.12 (90.62, 91.61), 19.11 (18.99, 19.22) vs. 19.09 (18.98, 19.19), both P < 0.05]; there were no significant differences in the incidence of daytime temperature difference, average relative humidity, precipitation, average wind speed, and maximum wind speed between the two groups. (3) the peak period of AAD occurrence was December (38 cases), which was followed by January (36 cases); and there were 26 cases of each month in May, June, July, and September, which were lower than the rest of months. It was shown by the temperature distribution that the minimum average temperature was in January (-12.46 centigrade), followed by December (-9.03 centigrade); the maximum average temperature was in July [(24.59±3.21)centigrade], followed by August [(23.14±3.64)centigrade]. (4) The patients was sorted according to the quartile of daily mean temperature, into < -5.2 centigrade, -5.2-10.7 centigrade, 10.7-20.4 centigrade, and > 20.4 centigrade groups, and each group had 104, 99, 98, 78 cases of AAD, respectively. The number of AAD in lowest temperature group was 1.33 times of the highest temperature group. In the 45-59 and 60-74 years, the number of AAD in lowest temperature group was higher than that in the highest temperature group (50 vs. 36, 26 vs. 13). In patients with hypertension, the number of AAD in lowest temperature group was higher than that in the highest temperature group (60 vs. 44). (5) The maximum air temperature, mean air temperature of the day from 5 days before to the onset day of AAD, and the lowest temperature from 3 days before to the onset day of AAD display slowly decrease trends, but there was no significant difference in daily temperature. The incidence of AAD in Urumqi and its peripheral areas was concentrated from January 1st to 2nd of each year. When the temperature was lower than -5.2 centigrade, AAD were more likely to attack. The 5 days changes of temperature and daily temperature before the attack were relevant with onset of AAD. It was speculated that the weather conditions such as air temperature may affect patient who has a past history of cardiovascular disease to attack AAD.

Association Between Ambient Temperature and Lower Urinary Tract Symptoms: A Hospital-Based Cross-Sectional Analysis.

To date, there is no overall agreement as to risk of ambient temperature for lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). Thus, we focused on ambient temperature as an environmental factor affecting LUTS and attempted to explain the temperature differences in LUTS severity in cases in real clinical practice. This was a multicenter, cross-sectional survey. The study involved 1612 men aged 40 years and older who visited 23 university hospitals in 10 major areas in South Korea between September 2010 and December 2011. The participants who had good overall mental and physical health, and complaint of LUTS were included. Korea Meteorological Administration data were used to determine daily average temperatures and daily temperatures on the interview dates at each site. The average age of the 1612 men was 66.57 ± 10.03 years. The mean International Prostate Symptom Score (IPSS) and symptom duration were 18.51 ± 6.77 and 3.79 ± 3.89 years, respectively. Daily average temperature and temperature difference ranged from -13.1 to 28.5 °C and 0 to 20.6 °C, respectively. Age was a significant risk factor for IPSS, symptom duration, prostate volume (PV), maximal urinary flow rate (Qmax), average urinary flow rate (Qave) and total voiding volume (P < 0.001) but not QOL. Logistic regression analysis after adjustment for age and PV revealed that Qave and total voiding volume were increased as the temperature declined. However, IPSS and Qmax did not show a statistically significant difference as the temperature declined. Our findings did not demonstrate an increased clinically significant risk of LUTS severity in connection with ambient temperature in clinical practice.

Association between ambient temperature and lower urinary tract symptoms: a community-based survey.

ABSTRACTPurpose The aim of this study was to evaluate the individual change of International prostate Symptom Score (IPSS) and Overactive Bladder Symptom Score (OABSS) in each patient by temperature conditions.Materials and Methods The severity of lower urinary tract symptoms (LUTS) was explored using the IPSS and OABSS questionnaires that were completed by 2.486 subjects (923 males and 1.563 females) aged 60 years and older. Korea Meteorological Administration data was used to determine daily average temperature and daily temperature difference on the interview dates at each site.Results The mean IPSS and mean age for males was 13.45±8.24 and 75.03±6.20 years, respectively. The mean OABSS and mean age for females was 4.41±3.10 and 73.74±6.03years, respectively. Daily average temperature and daily temperature difference ranged from-3.4-28.3oC and 2.2-16.9oC, respectively. Age was a significantly risk factor for IPSS, OABSS, and QoL (P<0.001, <0.001, and 0.005, respectively). After multiple regression analysis, daily average temperatures did not show a statistically significant change in IPSS and OABSS. Only daily temperature differences were associated with male LUTS.Conclusions While LUTS could be worsened in low temperatures generally, IPSS and OABSS were not affected by daily average temperature conditions. Daily temperature differences may be more influential than daily average temperatures.

Population differentiation and countergradient variation throughout the geographic range in the fern gametophyte Vittaria appalachiana.

Theory predicts that limited gene flow between populations will promote population differentiation, and experimental studies have found that differentiation is often explained by local adaptation in sexually reproducing angiosperms. However, few experiments have examined the drivers of differentiation among populations in asexual land plants with limited dispersal potential. Here, we evaluated the role of temperature in driving population differentiation in an asexual, obligate gametophyte fern species. We reciprocally transplanted Vittaria appalachiana gametophytes among six populations that spanned the species' geographic range in the Appalachian Mountains and Plateau. Temperature, survival, and senescence rates were measured for 1 year. Populations had significantly different fitness responses to different sites, consistent with the hypothesis that populations have differentiated across the species' range. There was some evidence for local adaptation in marginal populations and for countergradient selection favoring particularly robust genotypes at the northern range edge. Most populations had relatively high fitness at the site with the most stable temperature conditions and were negatively affected by decreasing minimum temperatures. Populations of Vittaria appalachiana exhibit highly variable responses to transplantation across the species' range, and only a small subset of these responses are due to local adaptation. Differences in daily minimum temperature explain some variation in fitness, but other site-specific factors also have significant impacts on transplant fitness. These results indicate that asexual, patchily distributed species with limited dispersal may exhibit population-specific responses to global climate change that have not been elucidated by empirical work focused on sexually reproducing angiosperms.