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PubMed2003

Climatic factors and the occurrence of vesicular stomatitis in New Mexico, United States of America.

Vesicular stomatitis (VS) outbreaks occurred in the southwestern United States of America in 1995, 1997 and 1998. The epidemiology of VS is not understood completely and some of the epidemiologic aspects of this disease are currently under investigation. In this study, daily maximum temperature, daily minimum temperature, daily mean temperature, daily mean relative humidity and daily total precipitation were collected at the Sevilleta Long Term Ecological Research site in central New Mexico. Discriminant analysis was used to identify the climatic variables best able to classify in which months VS would occur. The study found that the amounts of precipitation occurring two, ten, eleven and twelve months prior to the month in which cases were diagnosed, were the climatic variables that best described the occurrence of VS cases. The association of VS cases and precipitation suggests that, like numerous other arthropod-borne diseases, transmission of the disease-causing pathogen is linked to variations in climate.

Animals↗
PubMed1997

The effects of air mattress upon sleep and bed climate.

The purpose of this study was to investigate the effects of an air mattress upon sleep and bed climate. This air mattress, which employs a pump and timer to increase or decrease the inflation pressure in order to cure and prevent decubitus was tested. Six healthy female volunteers, aged 18 to 23, served as subjects. The experiments were carried out under three conditions: using regular Futon (Futon), the air mattress with pump and timer activated (Air+) and the same mattress without pump and timer activated (Air-). Room temperature and relative humidity were controlled at 22-23 degrees C and RH 50-60% respectively. Subjects' sleep was monitored by using EEG machine throughout the night, and subject's body temperature and bed climate were also continuously checked. Subjective estimation of bed and sleep were obtained before and after the recording sessions. Sleep onset latency and wake after sleep onset tended to be reduced in Air+ compared to Futon and Air-. The time and percentage of Stage 3 was increased significantly in the middle one third of the night in Air+. A significant difference was observed in bed climate of the waist area. Temperature tended to be higher in Futon than in Air+ and Air-, while relative and absolute humidity were significantly higher in Air+ and Air-. Significant difference between Air+ and Air- was observed only during one hour after sleep recordings started. Thermal sensation in the morning was cooler and comfort sensation tended to be better in Air+ and Air-. Subjective sleep estimation was somewhat good under all conditions. These results suggest that although these air mattresses do not affect sleep, we have to be cautious in using these mattresses as relative and absolute humidity were kept higher than with Futon. Further study on materials and construction of these air mattresses to decrease the humidity is needed.

Adult↗
PubMed2006

Forest environmental investments and implications for climate change mitigation.

Forest environmental conditions are affected by climate change, but investments in forest environmental quality can be used as part of the climate change mitigation strategy. A key question involving the potential use of forests to store more carbon as part of climate change mitigation is the impact of forest investments on the timing and quantity of forest volumes that affect carbon storage. Using an economic optimization model, we project levels of U.S. forest volumes as indicators of carbon storage for a wide range of private forest investment scenarios. Results show that economic opportunities exist to further intensify timber management on some hectares and reduce the average timber rotation length such that the national volume of standing timber stocks could be reduced relative to projections reflecting historical trends. The national amount of timber volume is projected to increase over the next 50 yr, but then is projected to decline if private owners follow an economic optimization path, such as with more forest type conversions and shorter timber rotations. With perfect foresight, future forest investments can affect current timber harvest levels, with intertemporal linkages based on adjustments through markets. Forest investments that boost regenerated timber yields per hectare would act to enhance ecosystem services (e.g., forest carbon storage) if they are related to the rate of growth and extent of growing stock inventory.

Air Pollution↗
PubMed2001

Differential effects of activity and climate on onset of subarachnoid hemorrhage.

Conflicting findings of the effect of climate on onset of subarachnoid hemorrhage (SAH) may result from the influence of strenuous activities which can trigger aneurysmal rupture independent of climatological factors. The effect of climate and patient activities on onset of SAH were analyzed. The clinical records of 786 consecutive patients with aneurysmal SAH admitted to our hospital for 10 years were reviewed. Activities at onset were categorized according to the intensity of strain at onset. Seasonal variation, circannual cyclic trend, and association with 90 meteorological factors were examined in each category and the results were compared between categories. Bimonthly occurrence in the light strain group showed a significant seasonal variation and cyclic trend with two peaks in early spring and fall, whereas no significant trend was detected in the overall patients and in the heavy strain group. The significant meteorological factors were global solar radiation, sunshine hours, changes in mean and minimum temperature and mean vapor pressure from the previous day, and minimum pressure in the previous 7 days. Lower global solar radiation in the light strain group was associated with onset with the lowest p value (p = 0.0046). No factors were significant in the heavy strain group. There is some evidence of the possible influence of climatological factors on onset of SAH without strenuous activity. Strenuous activity seems to affect onset more strongly, which masks any effect of climate.

Adult↗
PubMed2005

Climatic and aeroallergen risk factors for chronic obstructive pulmonary disease in horses.

OBJECTIVE: To estimate the association between climate and airborne pollen and fungal factors and chronic obstructive pulmonary disease (COPD) in horses. SAMPLE POPULATION: Data from 1,444 horses with a diagnosis of COPD. PROCEDURE: The Veterinary Medical Database was used to identify records of horses admitted to veterinary teaching hospitals in the United States and Canada between 1990 and 1999. Rainfall, mean minimum and maximum temperature, and maximum monthly pollen and fungal spore (mold) counts recorded at the city closest to where the hospital is located were identified for each month data were reported to the Veterinary Medical Database. Associations between climatic and aeroallergen data and monthly prevalence of COPD were estimated by use of cross-correlation and logistic regression models. RESULTS: Significant positive correlations were found between prevalence of COPD and rainfall 3 months previously, minimum temperature 1 and 2 months previously, total pollen counts measured 3 months previously, and total mold counts measured during the same month and 1 month previously. CONCLUSIONS AND CLINICAL RELEVANCE: Outdoor aeroallergens and climatic factors may contribute to the occurrence of COPD in horses.

Allergens↗
PubMed2003

Effects of dietary fiber on performance of multiparous lactating sows in a tropical climate.

Sixty-two multiparous Large White sows were used to determine the effect of dietary fiber level on lactation performance according to season under conditions of a humid tropical climate. This experiment was conducted in Guadeloupe (West French Indies, lat 16 degrees N, long 61 degrees W) between October 1999 and January 2001. Two seasons were distinguished a posteriori from climatic measurements parameters continuously recorded in the farrowing room. During the warm season, ambient temperature and relative humidity averaged 25 degrees C and 86.8%, respectively. The corresponding values for the hot season were 27.5 degrees C and 83.5%. Experimental diets fed during lactation were a control diet (C; 14% neutral detergent fiber) and a high-fiber diet (HF; 20% neutral detergent fiber) obtained by substitution of wheat middlings by wheat bran. The two diets were formulated to provide the same ratios between essential amino acids and lysine and between lysine and net energy. No interaction between season and diet composition was found for all criteria studied. Over the 28-d lactation, average daily feed intake (ADFI) was lower and body weight loss was higher (P < 0.001) during the hot season compared to the warm season (3,447 vs 4,907 g/d and 33 vs 17 kg, respectively). The number of stillborn piglets was higher (P < 0.05) during the hot season than during the warm season (2.0 vs 1.1 piglets, respectively). Litter growth rate and mean BW of piglets at weaning were reduced (P < 0.01) during the hot season vs the warm season (2.1 vs 2.3 kg/d and 7.7 vs 8.3 kg, respectively). The ADFI was similar for both diets and digestible energy (DE) intake tended to be lower (P = 0.06) with the HF diet (54.9 vs 59.3 MJ of DE/d for C sows) in relation with its lower DE concentration. The body weight loss was greater (P < 0.01) for HF sows than for C sows (30 vs 21 kg). Compared with the C diet, the HF diet increased (P < 0.05) litter growth rate and piglet body weight at weaning (2.3 vs 2.1 kg/d and 8.3 vs 7.7 kg/d for HF vs C, respectively). Season and diet composition did not affect the weaning-to-estrus interval. In conclusion, the hot season in humid tropical climates, which combines high levels of temperature and humidity, has a major negative effect on the performance of lactating sows.

Animal Feed↗
PubMed1985

Effects of climate on reproduction in cattle.

Animal environment is affected by climatic factors that include temperature, humidity, radiation, and wind. Extremes in climate alter energy transfer between the animal and its environment and can affect deleteriously reproduction. Seasonal variation of environment, nutrition, and management alters estrous activity and duration of estrus. Conception rates are reduced under stress of heat and cold. Endocrine functions are altered by climatic extremes. In hyperthermia, adrenal function is reduced, and this may allow the animal to cope with the environment because of the lower calorigenic actions of glucocorticoids. Estrogens are lower during the proestrus to metestrus period of the estrous cycle and during late gestation and appear to manifest their physiological actions through shorter duration of estrus and lower calf birth weights, respectively. Season alters endocrine profiles and influences fertility of males. Spermatogenesis is impaired, and testosterone is lower during early exposure to hyperthermia. Environmental modifications can alleviate stress of heat and cold to some extent. Experimentation using indices of environmental measures is needed to assess interactive effects of environment on reproduction.

Animals↗
PubMed2003

Does living in a cold climate or recreational skiing increase the risk for obstructive respiratory diseases or symptoms?

OBJECTIVES: Respiratory symptoms and obstructive pulmonary diseases experienced during exercise and in cold weather were analysed in a large postal questionnaire study of a general adult population living in a cold climate. The aim of this study was to assess the prevalence of shortness of breath (SOB) during exercise, or in cold weather, and to find out if the risks (odds ratio=OR) for asthma, chronic bronchitis, or SOB during exercise, or in cold weather, were affected by recreational cross-country skiing, or by outdoor work in a cold climate. RESULTS: Of the 7937 invited persons, 84% responded; 876 of them were outdoor workers and 1497 were recreational cross-country skiers. Of the non-smoking responders, asthmatic subjects had the highest prevalence of SOB during exercise in cold weather (78%-82%), but allergic and bronchitic persons also had significantly higher prevalence rates (22%-38% and 27%-59%, respectively) than healthy persons (10%-19%). In all categories, the prevalence of SOB was significantly higher among current smokers than among ex- or non-smokers. Risk factor analysis revealed increased risks for respiratory conditions among those who had a family history of obstructive airway disease, or allergy. Skiers did not have a significantly increased risk for asthma, or respiratory symptoms. Among outdoor workers the risk for SOB during exercise in cold weather, OR 1.23 (CI 1.03-1.47), and for chronic bronchitis, OR 1.77 (CI 1.21-2.60), was higher than among indoor workers. CONCLUSIONS: In conclusion, the risk for chronic bronchitis and bronchitic symptoms was elevated among outdoor workers, but not among regular recreational cross-country skiers, and the risk for asthma was not significantly elevated by regular exercising, or by working in a cold climate.

Adult↗
PubMed2005

The potential impact of climate on human exposure to contaminants in the Arctic.

Many northern indigenous populations are exposed to elevated concentrations of contaminants through traditional food and many of these contaminants come from regions exterior to the Arctic. Global contaminant pathways include the atmosphere, ocean currents, and river outflow, all of which are affected by climate. In addition to these pathways, precipitation, animal availability, UV radiation, cryosphere degradation and human industrial activities in the North are also affected by climate change. The processes governing contaminant behaviour in both the physical and biological environment are complex and therefore, in order to understand how climate change will affect the exposure of northern people to contaminants, we must have a better understanding of the processes that influence how contaminants behave in the Arctic environment. Furthermore, to predict changes in contaminant levels, we need to first have a good understanding of current contaminant levels in the Arctic environment, biota and human populations. For this reason, it is critical that both spatial and temporal trends in contaminant levels are monitored in the environment, biota and human populations from all the Arctic regions.

Animals↗
PubMedDate not supplied

Effect of climatic factors and population density on varicella zoster virus epidemiology within a tropical country.

Blood samples were collected from healthy subjects, aged 9 months-29 years in urban and rural communities from 4 distinct regions in Thailand, to determine the seroprevalence rate of varicella-zoster virus (VZV) antibody and its relationship with demographic, climatic, and socioeconomic factors. The overall seroprevalence rate was 52.8% and increased from 15.5% in the 9-month to 4-year-old group to 75.9% in the 20-29 year-olds. The age-adjusted seroprevalence was significantly higher in the cooler than in the warmer regions. In the warmer regions only, the age-specific seroprevalence was significantly higher in the urban population than in the rural population. In Thailand, climate is the main determinant of VZV seroprevalence. The delayed onset of natural immunity is more marked in warmer climate areas. Population density is a secondary determinant; in the warmer areas, the pattern of adolescent and adult susceptibility was greater in rural than in urban areas.

Adolescent↗
PubMed2002

Modeling relationships between climate and the frequency of human plague cases in the southwestern United States, 1960-1997.

The relationships between climatic variables and the frequency of human plague cases (1960-1997) were modeled by Poisson regression for two adjoining regions in northeastern Arizona and northwestern New Mexico. Model outputs closely agreed with the numbers of cases actually observed, suggesting that temporal variations in plague risk can be estimated by monitoring key climatic variables, most notably maximum daily summer temperature values and time-lagged (1 and 2 year) amounts of late winter (February-March) precipitation. Significant effects also were observed for time-lagged (1 year) summer precipitation in the Arizona model. Increased precipitation during specific periods resulted in increased numbers of expected cases in both regions, as did the number of days above certain lower thresholds for maximum daily summer temperatures (80 degrees F in New Mexico and 85 degrees F in Arizona). The number of days above certain high-threshold temperatures exerted a strongly negative influence on the numbers of expected cases in both the Arizona and New Mexico models (95 degrees F and 90 degrees F, respectively). The climatic variables found to be important in our models are those that would be expected to influence strongly the population dynamics of the rodent hosts and flea vectors of plague.

Arizona↗
PubMed1999

[Climate therapy for children with respiratory allergy].

Climate therapy is often proposed for children with severe allergic asthma which remains uncontrolled in spite of adapted treatment. The beneficial effects of climate therapy are related to the reduced allergenic load and to the fact that mites do not survive at high altitudes. Less exposure to allergens leads to improved respiratory function, decreased bronchial hyperreactivity and lower levels of total and specific IgE as well as markers of inflammation. These different actions combine to produce a lower prevalence of asthma at higher altitudes. Other advantages of climate therapy is related to better management of care by a multidisciplinary team. This in turn enables: a combined medial and paramedical approach to stablize the asthma with minimal effective doses of drug therapy; the development of a specific educational program aimed at improving therapeutic compliance; and an individualized education adapted to the learning problems which are often important in these children. The problems of the child being separated from his/her parents and the risk of recurrence after returning home must also be addressed and can generally be prevented by simple precautions.

Allergens↗
PubMed1999

Transaxillary thoracoscopic sympathectomy experience in a hot climate: management of the dominant hand.

Primary palmar hyperhydrosis is a functionally and socially disabling problem of unknown etiology, affecting adolescents and young adults, especially in hot climates. Thoracoscopic sympathectomy is the most effective treatment for palmar hyperhydrosis. Postsympathectomy rebound hyperhydrosis may limit its success, especially in hot climates. The aim of this study is to report experience with thoracoscopic sympathectomy in a hot climate, managing the dominant hand (unilateral), followed by the other hand at a later date, based on the patient's choice. One hundred twenty patients were operated on during a 3 year period. The mean operative time was 25 minutes. The procedure was successfully completed in 169 operated limbs and was abandoned in one limb because of severe pleural adhesions. The procedure was done for the dominant hand (unilateral) in 120 patients. Fifty patients returned for contralateral thoracoscopic sympathectomy. There were 18 postoperative complications. Most of the patients (95%) were discharged after an overnight stay. The early observed cure rate was high (97%). During the mean follow-up period of 300 days, there was no recurrence of the original symptoms, except for one patient in whom the nerve of Kuntz was found and diathermized on the second thoracoscopy with symptomatic relief. Rebound hyperhydrosis occurred in 40 patients (33% of the total; 21% in the unilateral group and 42% in the bilateral group). In conclusion, it seems that transaxillary endoscopic sympathectomy of the dominant hand is an alternative method of treatment for patients with hyperhydrosis. Managing the dominant hand first and giving the patient the chance to observe the severity of the rebound hyperhydrosis may facilitate the decision for contralateral sympathectomy.

Adult↗
PubMed2000

[Maintenance of African ostriches (Struthio carnelus) under Hessian climatic conditions--analysis of metereological data for the application of BML's expert recommendations of 1996].

A report is given on an analysis of meteorological data on five locations in the region of Hessia in order to apply the BML's expert recommendation concerning ostrich farming. According to this recommendation black ice, very strong frost and continuous rain should not make it necessary to keep the animals in pens longer than 3 days or more often than 10 days per month. Otherwise a dry paddock must be provided. It was investigated whether and how often the above mentioned weather conditions exceeded the critical duration or frequency in the last decades at the different locations. Previously the weather related terms which were used in the BML-recommendation were defined more precisely in order to provide an objective basis for the analysis. Frequent periods of frost lasting longer than 3 days with temperatures below -5 degrees C were found to be a critical factor. They occurred in 79 to 90% of the winter seasons under investigation, although the climate was thought to be rather mild in comparison to other regions. Frost can not be remedied by a dry paddock. Therefore the locations in question are not suitable for ostrich farming. The same conclusion holds at least for all locations with a colder climate. Black ice occurred only scarcely. At none of the investigated locations periods of continuous rain were longer than 3 days or occurred more often than 10 days per month. This result might not only be due to the given climatic conditions but also due to methodological reasons. It seems that the meteorological definition of continuous rain is too restricted to take the relevant precipitation for ostriches into account. It is suggested to find a new definition and consider factors like humidity and wind speed as well.

Animal Husbandry↗
PubMed1990

Precambrian evolution of the climate system.

Climate is an important environmental parameter of the early Earth, likely to have affected the origin and evolution of life, the composition and mineralogy of sedimentary rocks, and stable isotope ratios in sedimentary minerals. There is little observational evidence constraining Precambrian climates. Most of our knowledge is at present theoretical. Factors that must have affected the climate include reduced solar luminosity, enhanced rotation rate of the Earth, an area of land that probably increased with time, and biological evolution, particularly as it affected the composition of the atmosphere and the greenhouse effect. Cloud cover is a major uncertainty about the early Earth. Carbon dioxide and its greenhouse effect are the factors that have been most extensively studied. This paper presents a new examination of the biogeochemical cycles of carbon as they may have changed between an Archean Earth deficient in land, sedimentary rocks, and biological activity, and a Proterozoic Earth much like the modern Earth, but lacking terrestrial life and carbonate-secreting plankton. Results of a numerical simulation of this transition show how increasing biological activity could have drawn down atmospheric carbon dioxide by extracting sedimentary organic carbon from the system. Increasing area of continents could further have drawn down carbon dioxide by encouraging the accumulation of carbonate sediments. An attempt to develop a numerical simulation of the carbon cycles of the Precambrian raises questions about sources and sinks of marine carbon and alkalinity on a world without continents. More information is needed about sea-floor weathering processes.

Atmosphere↗
PubMed2001

Climate controls on dust storm occurrence in Maowusu Desert, Inner Mongolia, north China.

Dust storms occurring in arid and semi-arid regions play a main role in the evolution of landscapes. Climate is generally regarded to be important factors influencing the occurrence of dust storm, however, the way of climate controlling dust storms had been poorly understood. In this paper, we present the Ew Index model to describe the relationship between climate variables and dust storm frequency using the available meteorological data from three meteorological stations in Maowusu Desert. This index model explains 83.6%, 69.5% and 65.09% of the variance of dust storm frequency in three regions from the north to the south, respectively and this difference is probably caused by the difference of the human disturbance. The Ew Index model is an effective predictor of dust storm frequency and provides us a quite good understanding on the occurrence of dust storms in Maowusu Desert.

China↗
PubMed2001

Spatial distribution analysis on climatic variables in northeast China.

Information ecology is a new research area of modern ecology. Here describes the spatial distribution analysis methods of four sorts of climatic variables, i.e. temperature, precipitation, relative humidity and sunshine fraction in Northeast China. First, digital terrain models was built with large-scale maps and vector data. Then trend surface analysis and interpolation method were used to analyze the spatial distribution of these four kinds of climatic variables at three temporal scale: (1) monthly data; (2) mean monthly data of thirty years, and (3) mean annual data of thirty years. Ecological information system were used for graphics analysis on the spatial distribution of these climatic variables.

Algorithms↗
PubMed2000

[Simulation of potential responses of clear-cut of mixed coniferous and broadleaved Korean pine forest in Yichun to climate change by BKPF model].

The potential responses of forest succession in the clear-cut site of mixed coniferous and broad-leaved Korean pine forest (MCBLKPF) in Yichun, Heilongjiang Province to global climate change and elevated CO2 after 50 years by BKPF model were simulated. The results indicated that the densities of Pinus koraiensis and hardwood species(Fraxinus mandshurica, Tilia amurensis, Juglans mandshurica and Phellodendron amurense) would increase, while the densities of Larix olgensis, Betula platyphylla and Populus davidiana would decrease after 50 years. The stand densities would be slightly lower than those at the same age under the current climate condition. The stand productivity, total aboveground biomass and leaf area index will increase by 7-28%, 15-24% and 5-8%, respectively. Climate change would be beneficial to the forest succession from the clear-cut site to MCBLKPF.

Climate↗