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1.
Experiments were conducted in winter (October to January) and summer (May to August) seasons to study the effect of seasonal temperature variations on the vermicomposting of household waste using Eisenia fetida earthworms. The prevailing temperatures during experiments were in the range of ?2.7°C to 35.0°C during winter season and 18.0°C to 44.4°C during summer season. Organic matter degradation was higher during winter than summer season. The electrical conductivity (EC) of vermicomposts was increased in the range of 2.3–7.8% in winter season; however, the increase in EC was 0.9–1.8% during summer season for different waste mixtures. There was about 56.2–80% increase in total Kjeldahl nitrogen (TKN) content during winter season, whereas the TKN increase was 23.9–44% during summers. The C:N ratio also decreased remarkably in all the waste mixtures during vermicomposting in both the seasons. However, the C:N ratio reduction was more significant during winter (47–60%) than in summer (31–44%). After the observation period, the net worm biomass achieved was higher during winter than summer season. The temperature variations during winter supported the life activities of earthworms more favourably than in summer. The results indicated that growth and reproductive potential of the earthworms were affected not only by the quality and quantity of the feed but also by ambient temperature.  相似文献   

2.
Physiological properties of the temperate hermatypic coral Acropora pruinosa Brook with symbiotic algae (zooxanthellae) on the southern coast of the Izu Peninsula, Shizuoka Prefecture, central Japan, were compared between summer and winter. Photosynthesis and respiration rates of the coral with symbiotic zooxanthellae were measured in summer and winter under controlled temperatures and irradiances with a differential gasvolumeter (Productmeter). Net photosynthetic rate under all irradiances was higher in winter than in summer at the lower range of temperature (12–20°C), while lower than in summer at the higher range of temperature (20–30°C). The optimum temperature for net photosynthesis was apt to fall with the decrease of irradiance both in summer and winter, whereas it was higher in summer than in winter under each irradiance. At 25/ 50/100 μmol photons nr2 s?1, it was nearly the sea‐water temperature in each season. Dark respiration rate was higher in winter than in summer, especially in the range from 20–30°C. In both seasons the optimum temperature for gross photosynthesis was 28°C under 400 μmol photons nr2 s?1 and lowered with decreasing irradiance up to 22°C under 25 μmol photons nr2 s?1 in summer, while 20°C under the same irradiance in winter. The optimum temperature for production/respiration (P/R) ratio was higher in summer than in winter under each irradiance. Results indicated that metabolism of coral and zooxanthellae is adapted to ambient temperature condition under nearly natural irradiance in each season.  相似文献   

3.
We present data accumulated over the last 25 years on predation of radio-tracked released pheasants. In studies of birds during the autumn/winter at six pheasant shoots with high-density releases managed by full-time gamekeepers, predation of released pheasants by foxes before the shooting season began (July–September) averaged 19.2?±?4.0% per site, and during the shooting season (October 1st–February 1st), a further 15.9?±?1.9% were predated. The range in 3-year average predation rates between sites before shooting began was 8.6 to 42.4%. At seven different sites during the spring and summer, between 20 and 71% of released or wild hens that survived the shooting season were predated, mainly by foxes, between mid-March and mid-July. Predation was significantly higher at sites with low-level predator control (59?±?4.7%) compared to those with high-level control (30?±?5.3%). At three of the four sites with low predator control between 5 and 22% of nest failures were caused by incubating hens being predated by foxes. Our data quantify for the first time highly variable predation rates of released pheasants before and during the winter shooting season which we suggest was influenced by a range of site and management factors. During the spring and summer, our data provide evidence that predation of adult hen pheasants as well as nest predation can suppress breeding success and that predator control can reduce these losses.  相似文献   

4.
Long-term data on surface water temperature (SWT) from 9 lakes larger than 10 km2 located in different climatic regions in Austria were analysed for June–September 1965–2009. The lakes are situated north and south of the Alps, in the east bordering Hungary and in the west bordering Germany. Time series of air temperature (AT) and SWT were smoothed by the lowess function and linear trends. Water temperature for the year 2050 was estimated from (1) linear extrapolation of the time trend, (2) projection of the AT–SWT relation and (3) increase of average present day SWT (2000–2009) by 3°C in summer in the Alps as expected from models by climatologists. Results indicate a rise in SWT parallel to AT since the mid-1960s. On an annual basis, changes in water temperature were the greatest in spring and summer. A conservative estimate of the average increase of summer SWT until 2050 is 2°C (1.2–2.9°C), differentiated by region. As a consequence of warming water temperatures, the duration of thermal stratification will increase and mixing and retention time will be affected. Changes in the food web are difficult to forecast, but will strongly depend on local environmental conditions and will therefore be different for individual lakes.  相似文献   

5.
This study aimed to investigate the impact of dust storms on short-term mortality in Kuwait. We analyzed respiratory and cardiovascular mortality as well as all-cause mortality in relation to dust storm events over a 5-year study period, using data obtained through a population-based retrospective ecological time series study. Dust storm days were identified when the national daily average of PM10 exceeded 200 μg/m3. Generalized additive models with Poisson link were used to estimate the relative risk (RR) of age-stratified daily mortality associated with dust events, after adjusting for potential confounders including weather variables and long-term trends. There was no significant association between dust storm events and same-day respiratory mortality (RR = 0.96; 95 %CI 0.88–1.04), cardiovascular mortality (RR = 0.98; 95 %CI 0.96–1.012) or all-cause mortality (RR = 0.99; 95 %CI 0.97–1.00). Overall our findings suggest that local dust, that most likely originates from crustal materials, has little impact on short-term respiratory, cardiovascular or all-cause mortality.  相似文献   

6.
Seasonal variation in the incidence of tuberculosis (TB) has been widely assumed. However, few studies have investigated the association between extreme temperatures and the incidence of TB. We collected data on cases of TB and mean temperature in Fukuoka, Japan for 2008–2012 and used time-series analyses to assess the possible relationship of extreme temperatures with TB incident cases, adjusting for seasonal and interannual variation. Our analysis revealed that the occurrence of extreme heat temperature events resulted in a significant increase in the number of TB cases (relative risk (RR) 1.20, 95 % confidence interval (CI) 1.01–1.43). We also found that the occurrence of extreme cold temperature events resulted in a significant increase in the number of TB cases (RR 1.23, 95 % CI 1.05–1.45). Sex and age did not modify the effect of either heat or cold extremes. Our study provides quantitative evidence that the number of TB cases increased significantly with extreme heat and cold temperatures. The results may help public health officials predict extreme temperature-related TB incidence and prepare for the implementation of preventive public health interventions.  相似文献   

7.
The effect of various combinations of temperature, which increases from 14°C up to 25°C in the summer season, and salinity, which varies from 34 to 12‰ in the early stages of development of the sea star Asterina (= Patiria) pectinifera (Müller et Troschel) from Vostok Bay, Sea of Japan, was studied. The most vulnerable process in the early ontogenesis of A. pectinifera is its embryonal development, which is completed successfully within narrow ranges of temperature (20–22°C) and salinity (34–26‰). The ability of gametes to fertilize was retained in wider ranges of temperature and salinity. The dipleurula was the most responsive of the larval stages; the resistance of blastula, bipinnaria, and brachiolaria at ages of 12.5 and 15.5 days was almost the same for fluctuations of temperature from 14 up to 25°C and salinity from 34 to 18 and 16‰ Settling of the brachiolaria and completion of metamorphosis were also responsive to variations in the environmental factors. Settling of the larvae was faster at 17°C without illumination (on the 22nd–24th days of development) than at 22°C with the day-night mode (27th–28th day of development). The lack of light apparently had a positive effect on the settling of the brachiolaria.  相似文献   

8.
Sphagnum palustre L. is one of the few Sphagnum species distributed in the warm‐temperate zone. To elucidate the mechanisms that enable S. palustre to maintain its productivity under warm climatic conditions, we examined the temperature conditions and photosynthetic characteristics of this species in a lowland wetland in western Japan. Moss temperatures during the daytime were much lower than the air temperature, particularly during summer. The optimum temperature for the net photosynthetic rate was approximately 20°C, irrespective of the season, but summer and autumn samples maintained high rates at higher temperatures as well. The net photosynthetic rate at near light saturation was much higher during summer–autumn than during spring–winter. A model estimation in which net production was calculated from the photosynthetic characteristics and microclimatic data showed that both the low temperature of the moss colony and the seasonal shift in photosynthetic characteristics are among the mechanisms that enable this species to maintain its productivity under warm climatic conditions.  相似文献   

9.
The present study was conducted to examine differential expression pattern of HSP genes and adaptability in Indian goat breeds of semi-arid region. The study was conducted in five animals from each breed viz. Barbari, Sirohi, and Jhakrana during winter, thermo-neutral and summer seasons. The respiratory rate (RR) and rectal temperature (RT) of the goats were recorded at 09:00 h during the study period. The blood samples were collected for RNA isolation, cDNA synthesis, and quantitative analysis of HSP genes expression by quantitative RT-PCR. The RR increased significantly (p < 0.01) during summer as compared to winter and thermo-neutral season however, RT did not change (p > 0.05) during different seasons. The expression of HSP genes was significantly (p < 0.01) increased during summer (high THI) as compared to thermo-neutral season in all the goat breeds. Among HSPs, only HSP90 was upregulated (p < 0.01) in Jhakrana goats during winter as compared to thermo-neutral season. The deviation in expression of HSP genes during summer and winter with respect to thermo-neutral season was minimum in Barbari goats. Therefore, it can be concluded that Barbari goats possessed better adaptability during summer and winter as compared to Sirohi and Jhakrana goats in semi-arid climatic conditions of India.  相似文献   

10.
Trenching (Tr), root biomass regression (RR), and root excising (RE) methods were used to estimate the contribution of root (RR) and heterotrophic (HR) respiration to soil respiration (SR) in a cool-temperate deciduous forest in central Japan. The contribution ratios of RR to SR were 23 % (?16 to 46 %), 11 % (?19 to 61 %), and 115 % (20 to 393 %), as estimated by the Tr, RR, and RE methods, respectively. The contribution ratio showed clear seasonal variation with high values in summer for the Tr method, while they were undetectable for the RR and RE methods because of some methodological problems. These results suggest the Tr method is the best of the three methods used to estimate the contribution ratio of RR and HR to SR in the forest. Annual SR, RR, and HR rates, estimated by the Tr method, were 479, 369, 110 gC m?2 year?1, respectively. The seasonal variation of SR was mainly influenced by HR (77 %) throughout the year, while the influence of RR on SR was strongest in summer (46 %). This effect occurred because RR (Q 10 = 7.5) is more sensitive to temperature than HR (Q 10 = 3.2). Also, the contribution of fine RR to total RR was higher than that of coarse RR because of high respiratory activity (Q 10 and R 10) as well as the large biomass of fine roots. These results suggest that each component of SR responds differently to the same environmental factors and their relative influence on SR changes across the seasons.  相似文献   

11.
Abstract. Adult female mosquito populations were monitored at weekly intervals during spring-autumn (November-March) for 4 years (1991-95) using dry-ice-baited light traps at forty sites in the Murray Valley of Victoria, Australia. Among twenty species of mosquitoes collected, Culex annulirostriswas the most abundant (66.6 ± 9.3%) followed by Cx australicus(15.3 ± 7.7%). From a total of 476, 682 mosquitoes collected, nearly all were females and only 1295 (0.27%) were males. Mosquito population densities were generally higher in 1992-93 and 1993-94 seasons than in 1991-92 and 1994-95 seasons. Greatest densities of Cx annulirostrisand Cx australicusoccurred in 1992-93, coinciding with outbreaks of Ross River (RR) and Barman Forest (BF) arboviruses causing human polyarthritis. In the majority of shires, Cx australicuswas the predominant species from spring to early summer (November and December), then was replaced by Cx annulirostrisfrom mid-summer to autumn (January-April). In three shires, Aedes bancroftianusand Ae.sagaxpredominated during the early part of the season. Densities of both Cx annulirostrisand Cx australicuswere related to temperature. Cx australicusadults were found to be trapped when the mean ambient temperature exceeded 6d?C, with peak population recorded at 20d?C. Cx annulirostrisadult density increased when the mean temperature rose above 12d?C, reaching a peak during February and March when temperature exceeded 25d?C. Cx annulirostrisdeclined rapidly from April onwards, with no adult activity evident from May to November. Population densities of Aedesspp. were generally less than reported from earlier studies, possibly due to lower rainfall in spring and summer as well as reduced flood irrigation practices. In each year, a significant correlation was detected between Cx annulirostrisdensity and RR virus incidence in humans. As Cx annulirostrisis the predominant local mosquito species and feeds on a wide spectrum of hosts including man, it seems likely that Cx annulirostrisis the major vector of RR in the inland Murray Valley region.  相似文献   

12.
13.
Hand, foot and mouth disease (HFMD) is a contagious viral illness that commonly affects infants and children. The underlying risk factors have not yet been systematically examined. This study analyzed the short-term effects of meteorological factors on children HFMD in Guangzhou, China. Daily count of HFMD among children younger than 15 years and meteorological variables from 2009 to 2011 were collected to construct the time series. A generalized additive model was applied to estimate the effects of meteorological factors on HFMD occurrence, after adjusting for long-term trend, seasonal trend, day of week, and public holidays. A negative association between temperature and children HFMD occurrence was observed at lag days 1–3, with the relative risk (RR) for a 1 °C increase on lag day 2 being 0.983 (95 % confidence intervals (CI) 0.977 to 0.989); positive effect was found for temperature at lag days 5–9, with the highest effect at lag day 6 (RR?=?1.014, 95 % CI 1.006 to 1.023). Higher humidity was associated with increased HFMD at lag days 3–10, with the highest effect at lag day 8 (RR?=?1.009 for 1 % increase in relative humidity, 95 % CI 1.007 to 1.010). And we also observed significant positive effect for rainfall at lag days 4 and 8 (RR?=?1.001, 95 % CI 1.000 to 1.002) for 1-mm increase. Subgroup analyses showed that the positive effects of temperature were more pronounced among younger children. This study suggests that meteorological factors might be important predictors of children HFMD occurrence in Guangzhou.  相似文献   

14.
Obese subjects may be more vulnerable to injury from heat stress, and appear to be less efficient at thermoregulation. Sweat rate, tympanic temperature and osmolality in obese subjects were investigated in Japan during two seasons. The purpose of this study was to examine the relationship between obesity, thermoregulatory response and season. Five obese (BMI, 32.0?±?4.9 kg/m2) and five non-obese (BMI, 23.2?±?2.9 kg/m2) men participated in this experiment at latitude 35°10′ N and longitude 136°57.9′E. The average atmospheric temperature was 29.1?±?1.0 °C in summer and 3.3?±?1.4 °C in winter. Tympanic temperature and sweat rate were measured during leg water immersion at 42 °C for 30 min. Blood samples were analyzed for plasma osmolality. The relationship between tympanic temperature and sweat rate decreased significantly in obese compared to in non-obese subjects in both seasons, there being a lowered sweat rate for any core temperature in obese subjects. Plasma osmolality was significantly higher in obese than in non-obese subjects in both seasons. Thermal sensation increased significantly in non-obese than in obese in winter but not in summer. Our data show that thermoregulatory responses are attenuated in obese subjects compared with controls, suggesting that obese people are at increased risk of heat-related illnesses.  相似文献   

15.
Heat waves kill more people in the United States than hurricanes, tornadoes, earthquakes, and floods combined. Recently, international attention focused on the linkages and impacts of human health vulnerability to urban climate when Western Europe experienced over 30,000 excess deaths during the heat waves of the summer of 2003-surpassing the 1995 heat wave in Chicago, Illinois, that killed 739. While Europe dealt with heat waves, in the United States, Phoenix, Arizona, established a new all-time high minimum temperature for the region on July 15, 2003. The low temperature of 35.5 degrees C (96 degrees F) was recorded, breaking the previous all-time high minimum temperature record of 33.8 degrees C (93 degrees F). While an extensive literature on heat-related mortality exists, greater understanding of influences of heat-related morbidity is required due to climate change and rapid urbanization influences. We undertook an analysis of 6 years (2001-2006) of heat-related dispatches through the Phoenix Fire Department regional dispatch center to examine temporal, climatic and other non-spatial influences contributing to high-heat-related medical dispatch events. The findings identified that there were no significant variations in day-of-week dispatch events. The greatest incidence of heat-related medical dispatches occurred between the times of peak solar irradiance and maximum diurnal temperature, and during times of elevated human comfort indices (combined temperature and relative humidity).  相似文献   

16.
The roles of weather variability and sunspots in the occurrence of cyanobacteria blooms, were investigated using cyanobacteria cell data collected from the Fred Haigh Dam, Queensland, Australia. Time series generalized linear model and classification and regression tree (CART) model were used in the analysis. Data on notified cell numbers of cyanobacteria and weather variables over the periods 2001 and 2005 were provided by the Australian Department of Natural Resources and Water, and Australian Bureau of Meteorology, respectively. The results indicate that monthly minimum temperature (relative risk [RR]: 1.13, 95% confidence interval [CI]: 1.02–1.25) and rainfall (RR: 1.11; 95% CI: 1.03–1.20) had a positive association, but relative humidity (RR: 0.94; 95% CI: 0.91–0.98) and wind speed (RR: 0.90; 95% CI: 0.82–0.98) were negatively associated with the cyanobacterial numbers, after adjustment for seasonality and auto-correlation. The CART model showed that the cyanobacteria numbers were best described by an interaction between minimum temperature, relative humidity, and sunspot numbers. When minimum temperature exceeded 18°C and relative humidity was under 66%, the number of cyanobacterial cells rose by 2.15-fold. We conclude that weather variability and sunspot activity may affect cyanobacteria blooms in dams.  相似文献   

17.
The wandering glider dragonfly, Pantala flavescens (Fabricius), arrives in Japan from tropical regions every spring. The offspring colonize areas throughout Japan, with rapid increases in populations in the autumn, but all individuals die in the winter, suggesting low tolerance to low temperatures. However, few quantitative data on egg development and water temperature have been reported for this species. Females at the reproductive stage were collected from fields throughout the flying season and their eggs released using an artificial oviposition technique. Almost all of the eggs were fertilized. Egg size was stable throughout the seasons. Most eggs hatched within a period of 5 days at high water temperatures (35 and 30 °C), which were recorded in the shallow ponds and rice paddy fields from summer to early autumn. However, the egg-stage duration increased with declining water temperature. All eggs in water at 15 °C had failed to hatch by 90 days. The calculated critical temperature of water was determined to be approximately 14.3 °C; the total effective temperature for the egg stage was about 80 degree-days. Thus, low water temperatures in winter may prevent P. flavescens overwintering in Japan.  相似文献   

18.
Carbon dioxide and methane exchange of a north-east Siberian tussock tundra   总被引:1,自引:0,他引:1  
Carbon dioxide, energy flux measurements and methane chamber measurements were carried out in an arctic wet tussock grassland located on a flood plane of the Kolyma river in NE Siberia over a summer period of 155 days in 2002 and early 2003. Respiration was also measured in April 2004. The study region is characterized by late thaw of the top soil (mid of June) and periodic spring floods. A stagnant water table below the grass canopy is fed by thawing of the active layer of permafrost and by flood water. The climate is continental with average daily temperature in the warmest months of 13°C (maximum temperature at midday: 28°C by the end of July), dry air (maximum vapour pressure deficit at midday: 28 hPa) and low rainfall of 50 mm during summer (July–September). Summer evaporation (July–September: 103 mm) exceeded rainfall by a factor of 2. The daily average Bowen ratio (H/LE) was 0.62 during the growing season. Net ecosystem CO2 uptake reached 10 μmol m−2 s−1 and was related to photon flux density (PFD) and vapour pressure deficit (VPD). The cumulative annual net carbon flux from the atmosphere to the terrestrial surface was estimated to be about −38 g C m−2 yr−1 (negative flux depicts net carbon sink). Winter respiration was extrapolated using the Lloyd and Taylor function. The net carbon balance is composed of a high rate of assimilation in a short summer and a fairly large but uncertain respiration mainly during autumn and spring. Methane flux (about 12 g C m−2 measured over 60 days) was 25% of C uptake during the same period of time (end of July to end of September). Assuming that CH4 was emitted only in summer, and taking the greenhouse gas warming potential of CH4 vs. CO2 into account (factor 23), the study site was a greenhouse gas source (at least 200 g Cequivalent m−2 yr−1). Comparing different studies in wetlands and tundra ecosystems as related to latitude, we expect that global warming would rather increase than decrease the CO2-C sink.  相似文献   

19.
西双版纳热带季节雨林与橡胶林土壤呼吸的季节变化   总被引:6,自引:0,他引:6  
采用挖壕沟法与红外气体分析法,研究了西双版纳热带季节雨林和人工橡胶林内土壤呼吸包括根系呼吸、异养呼吸的干湿季动态变化.结果表明:季节雨林内土壤呼吸和异养呼吸速率均显著大于橡胶林(P<0.01),但根系呼吸差异不显著;土壤温湿度是呼吸速率变化的主要影响因子,季节雨林和橡胶林内土壤呼吸和异养呼吸速率均为雨季>干热季>雾凉季,但季节雨林内根系呼吸为雨季>雾凉季>干热季,而橡胶林内为雾凉季>雨季>干热季;季节雨林内根系呼吸对土壤呼吸的贡献率(29%)小于橡胶林(42%,P<0.01),而季节雨林内异养呼吸对土壤呼吸的贡献率为71%、橡胶林为58%;当5 cm土壤温度在12 ℃~32 ℃范围内变化时,季节雨林内土壤呼吸及根系呼吸、异养呼吸的Q10值均大于橡胶林,且异养呼吸的Q10值最大而根系呼吸的Q10值最小.  相似文献   

20.
The effect of light and temperature on the growth and photosynthesis of the Japanese agarophyte, Gracilariopsis chorda (Gracilariaceae, Rhodophyta), was determined to better understand its physiology so that we could identify candidates for mass cultivation. Above the photosynthetic active radiation of 66 μmol photons m?2 s?1, photosynthetic rates saturated for all strains that were collected from six different locations (Hokkaido, Chiba, Tokushima, Saga, Kagoshima, and Okinawa); furthermore, either photosynthesis or growth was observed at all temperature treatments examined in our study (4–32 °C for photosynthesis, 16–32 °C for growth experiments). We identified a temperature range for optimal photosynthesis and growth, which occurred within 20.1–29.1 °C and roughly correlated with the water temperatures of the collection locations and strongly suggests that this species tolerates a wide variety of water temperature. In particular, the Kagoshima strain had the widest range of optimal temperatures (20.8–29.1 °C), whereas the Saga strain had the narrowest range (23.1–27.3 °C). It is important to note that all the optimal temperature ranges overlapped among the strains; therefore, no definitive distinction can be determined. The broad tolerance to temperatures commonly observed from northern to southern Japan suggests that the cultivation of this species should succeed during spring to summer in the majority of the coastal regions in Japan.  相似文献   

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