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At least 55 records · Page 3Linked to original sources
PubMed2000

Microclimate monitoring of indoor environments using piezoelectric quartz crystal humidity sensors.

The aim of this paper is to describe indoor microclimate monitoring at two different locations, Sandham Memorial Chapel, in Hampshire, England, and the castle El Alcázar, in Segovia, Spain. Piezoelectric quartz crystal sensors with novel humidity sensitive poly(ethyleneimine) coatings and Pt resistance thermometers were used to measure the relative humidity (RH) and temperature gradients across one of the paintings of the British artist, Stanley Spencer, housed in Sandham Memorial Chapel. The measurement period extended from December 1997 to September 1998. Each coated crystal was set in its own housing from which temperature and RH measuring circuits were connected via a cable to the computer. The 9 month monitoring period incorporated the range in seasons from winter through to autumn. Between December and February the RH at the back of the painting was found to be lower than that at the front. In March and April the reverse was true. Additionally, there were large spikes in the data in some of the months for both RH and temperature, probably caused by direct sunlight falling on the sensors. At the second site monitoring was performed for a shorter period, from December 1997 to early January 1998. It served, however, to show that abrupt changes can occur in the microclimate surrounding the painting. These fluctuations can with time lead to alterations to the paint surface and result eventually in cracking and damage to the art work.

Air Pollution, Indoor↗
PubMed2003

Influence of sugar availability and indoor microclimate on survival of Anopheles gambiae (Diptera: Culicidae) under semifield conditions in western Kenya.

The influence of indoor microclimate on survival of female Anopheles gambiae sensu stricto Giles (Diptera: culicidae) mosquitoes fed on different nutrition sources was evaluated in a semifield experimental hut exposed to ambient climate in western Kenya. Cages of mosquitoes (n approximately 50 per cage) were placed in nine positions within the hut combining three different sides and three different heights. At each height and side, mosquitoes were offered either human blood (once every 2 d), glucose (6% wt:vol) or a combination of the two diets over three experiments so that each cage position received one diet source. The effect of diet on survival was significant with mean survival times of 14 d for mosquitoes fed blood alone, 29 d for sugar alone and 33 d for blood plus sugar. Sugar availability decreased the odds of mortality approximately 85% compared with the blood group. Micro heterogeneities of temperature but not relative humidity also influenced survival although to a much lesser extent. The side but not height within the hut at which mosquitoes were placed, influenced survival but could not be explained by either temperature or relative humidity differences. The potential influence of seemingly minor heterogeneities of indoor microclimate upon vector longevity and vectorial capacity may merit further investigation. Also, the availability of sugar was shown to be a potentially crucial determinant of vectorial capacity. Compared with blood alone, the availability of sugar served to increase survival potential of vectors beyond ages at which they are old enough to transmit malaria.

Animals↗
PubMed2006

[Diurnal dynamics of microclimate at different succession stages of vegetation communities in inner-river wetland of Zhenjiang City].

To study the diurnal dynamics of microclimate at different succession stages of vegetation communities in the inner-river wetland of Zhenjiang City, three typical communities were chosen, and the light intensity, air temperature, soil temperature, and air relative humidity were measured. The results showed that with the succession of barren land --> Phalaris arundinacea --> Phragmites communis, the diurnal mean values of light intensity, air temperature, and soil temperature decreased from 1204.7 micromol x m(-2) x s(-1) to 141.28 micro.mol x m(-2) x s(-1), 32.2 degrees C to 24.9 degrees C, and 21.83 degrees C to 19.47 degrees C, and their daily variations decreased from 1126 micromol x m(-2) x s(-1) to 265 miromol x m(-2) x s(-1), 12.75 degrees C to 4.8 degrees C, and 4.5 degrees C to 2.1 degrees C, respectively. The air relative humidity increased from 58.95% to 87.3%, while its variation decreased from 29.75% to 5.15%. Habitats were open at early succession stage but more closed at late succession stage, microclimatic conditions developed towards much more cloudy, cold, and moist, and microclimate had a less fluctuation. There were definite correlations among the light intensity, air temperature, soil temperature, and air relative humidity in the vegetation communities, but the correlation coefficients among the test factors were differed at different succession stages.

China↗
PubMed1991

[Study of mortality among workers exposed to heating microclimate (epidemiological study)].

The article presents results of the study of mortality rates and causes of a retrospective cohort of workers engaged in a metallurgical plant, affected by different degrees of heating microclimate. The results of the study confirmed statistically verified high mortality risks among those engaged in the labour conditions characterized by the heating microclimate exceeding the admissible levels, as compared with the general male population in the Moscow region, with taking into account mortality from different causes (excepting accidents, traumas and poisonings), and from blood diseases, hypertension, IHD and respiratory diseases.

Adult↗
PubMed1990

[Effects of covering the windowpane with plastic film on microclimate and sunshine of the living room in a cold region].

Experiments were made to ascertain the effects of covering windowpane with plastic film in Hulunbeir region on microclimate and sunshine intensity in the living room. It was found that a good regulative effect on the room microclimate resulted by covering the windowpane with plastic film in the cold region. The room temperature rose distinctly. No evident effects were found on ultra-violet radiation and illumination. But the concentration of carbon dioxide increased to some extent. Attention should be paid to ventilation of the room.

China↗
PubMed1988

[Setting standards for the industrial microclimate via integral indices under conditions close to overheating].

The possibilities of the WBGT and Belding and Hutch methods for standardization of the industrial microclimate in conditions, near to overheating, are discussed. The acceptable WBGT temperatures according to the norms of NIOSH are compared with the sanitary norms existing in this country. It is pointed out that the NIOSH norms allow significantly higher temperatures of the air (up to 10 degrees C) from the regulated according to the Bulgarian State Standards (BSS) 14776-79. The differences with the sanitary norms, regulating the radiant microclimate are also considerable. On this basis a conclusion is made, that the application of the WBGT method in the sanitary practice in this country should be preceded by the standardization of the allowable WBGT temperatures. The basic shortcomings of the method Belding-Hutch are mentioned: inaccuracies in the equation of the heat balance, incongruity of the accepted criteria with the up-to-date physiological data. The comparison of the two discussed methods show, that considerable differences in the interpretation of one and the same microclimatic conditions are possible. A modification of the method Belding-Hutch is proposed. The proposed model can be used in standardization of the optimum and the allowable microclimatic parameters depending on the heat radiation, clothes, on the negative temperatures a.o. A set of graphics for determination of temperature is proposed without using the globe thermometers by velocity, relative humidity, temperature of the air and heat radiation.

Climate↗
PubMed1977

[Veterinary health examination of the microclimate of the cow complex in the Vidin district].

Studied was the dynamics of the microclimate at the cow complexes in the district of Vidin, where cows are raised of the Dutch Black Pied, Bulgarian Simmental, and Bulgarian Red cattle breeds. The temperature and relative humidity dynamics of the air was followed up as well as the values of ammonia gas and carbon dioxide, the microbial contamination, the coefficient of natural illumination, and the level of noise. The effectiveness of the ventilation system was assessed by direct and indirect criteria as suggested by the authors. The veterinary and sanitary evaluation by individual elements of the microclimate is carried out on the basis of normative documents in the People's Republic of Bulgaria, USSR, and GDR.

Air↗
PubMedDate not supplied

[The dynamics of the persistence characteristics of staphylococci under the action of the microclimate of a speleotherapy mine].

A decrease in the persistence characteristics of staphylococci under the influence of microclimate in a spelean pit has been demonstrated under experimental conditions. Clinical investigations have confirmed the capacity of speleotherapy to decrease the microbial contamination of the upper respiratory tract and to inhibit the persistence properties of staphylococcal microflora in children with respiratory allergosis, which seems to be the basis of the positive effect achieved by treatment with microclimate in a spelean pit.

Adolescent↗
PubMedDate not supplied

[The treatment of patients with chronic cerebral circulatory failure by using laser puncture and the microclimate of the biotron].

A mode is proposed of treatment of chronic cerebrovascular disorders, such as initial manifestations of cerebral blood supply insufficiency (IMBSI) and dyscirculatory encephalopathy (DE) stage I-II in hypertensive disease, involving the use of laser puncture and microclimate of biotron. All patients (n = 162) were exposed to laser puncture (10-12 procedures). Laser puncture treatments were devised according to classical approaches of reflexotherapy, using determinants of electropuncture diagnostic method by Riodoraku. The treatments were carried out with the aid of infrared portable laser "Biomed-001". IMBSI patients presenting with vegetovascular dystonia and about 70% of IMBSI patients presenting with hypertensive disease derived benefit from a course of laser puncture, as evidenced by REG, EEG, acupuncture diagnosis, iridodiagnosis according. In DE stage I-II patients and about 30% IMBSI patients presenting with hypertensive disease good therapeutic effect occurred after treatment in a ward with a stable microclimate of biotron. The proposed method can be used for treating chronic cerebrovascular disorders and administering stroke prophylaxis.

Acupuncture Points↗
PubMed1996

[Revising sanitary norms of microclimate in industrial accommodations].

The article outlines new edition of a project "Sanitary norms of microclimate in industrial compartments". Up-to-date scientific data, results of studies concerning human heat state in experimental and industrial conditions, evaluation of the workers' health state helped to modify optimal and allowable parameters of microclimate, to rectify requirements for measurement conditions and measuring devices. When the recommended temperature could not be maintained, the duration of work in such conditions should be limited for prevention of overheating and overcooling. To examine prophylactic measures against overheating, the authors suggested an integral characteristic of heating environmental load (TNS-index) and set its safe values.

Body Temperature Regulation↗
PubMed1998

[The influence of dust and heating microclimate on lipid peroxidation].

In experimental pneumoconiosis both under normal and heating ambient temperature lipid peroxidation is not activated, although heating microclimate increases alteration of lung tissue and induces rapid and intensive pulmonary fibrosis. Association of dust and heating microclimate prolongs a period of "stress" myocardial affliction due to intensified lipid peroxidation and exhausted endogenous glutathione peroxidase, afterwards lipid peroxidation decreases with progressing sclerosis and fat degeneration in heart.

Animals↗
PubMed2004

Seasonal change in terrestriality of chimpanzees in relation to microclimate in the tropical forest.

Seasonal change in time spent for terrestrial behavior of chimpanzees was investigated from the viewpoint of the distribution of food and microclimate in the forest at Bossou, Guinea, West Africa. Daily and monthly data for activity budgets of three focal animals, climatic variables in the forest, and indices of fruit availability and distribution of fruit-bearing trees were estimated and analyzed. Mean activity budgets calculated by monthly means were 23.4% for terrestrial behavior (range, 2.9% in August to 42.1% in November) and 76.6% for arboreal behavior. Chimpanzees spent more time on the ground in warm or dry months. Chimpanzees also spent less time in trees in months with high fruit production (trees of diameter at breast height >/=10 cm). The daily percentage of terrestrial behavior showed a positive correlation with maximum temperature and a negative correlation with the minimum humidity of the day. Only maximum temperature of the observation day influenced time spent on the ground significantly, as analyzed by generalized linear models (GLZ), which included all variables (fruit production, distribution of fruit-bearing trees, and climatic variables). It was concluded that the reason why arboreal behavior increased in the rainy season was not owing to the vertical distribution of food, but rather in order to reduce thermoregulation costs by resting in trees during cool periods and taking advantage of the vertical structure of the microclimate in the tropical forest (i.e., higher temperatures in higher positions).

Animals↗
PubMed1983

Drug absorption by the rat jejunum perfused in situ. Dissociation from the pH-partition theory and role of microclimate-pH and unstirred layer.

In anaesthetized rats the rate of appearance of benzoic acid and aminopyrine in jejunal venous blood was measured; the pH of the luminal perfusion solution was varied between 4 and 10.5. The pH-absorption curves were less steep than predicted by the unmodified pH-partition theory. A reduction of the mucosal unstirred layer thickness by means of the segmented-flow technique considerably increased the absorption rate without essentially changing the shape of the pH-absorption curves. The pH at the surface of the jejunal mucosa was 6.0, 6.5, 6.6, and 8.0 for luminal solutions of pH 4.0, 6.0, 8.0, and 10.8, respectively. From the absorption data the microclimate-pH was calculated which would explain best the observed pH-absorption curves. These calculated pH-values correspond well to the values measured at the mucosal surface. Therefore, it was concluded that a microclimate-pH caused the deviation of the intestinal pH-absorption curves of benzoic acid and aminopyrine from the prediction of the unmodified pH-partition theory. The mucosal unstirred layer represented only a considerable permeation resistance and was not responsible for the deviating shape of the pH-absorption curves.

Aminopyrine↗
PubMed2006

Neighborhood microclimates and vulnerability to heat stress.

Human exposure to excessively warm weather, especially in cities, is an increasingly important public health problem. This study examined heat-related health inequalities within one city in order to understand the relationships between the microclimates of urban neighborhoods, population characteristics, thermal environments that regulate microclimates, and the resources people possess to cope with climatic conditions. A simulation model was used to estimate an outdoor human thermal comfort index (HTCI) as a function of local climate variables collected in 8 diverse city neighborhoods during the summer of 2003 in Phoenix, USA. HTCI is an indicator of heat stress, a condition that can cause illness and death. There were statistically significant differences in temperatures and HTCI between the neighborhoods during the entire summer, which increased during a heat wave period. Lower socioeconomic and ethnic minority groups were more likely to live in warmer neighborhoods with greater exposure to heat stress. High settlement density, sparse vegetation, and having no open space in the neighborhood were significantly correlated with higher temperatures and HTCI. People in warmer neighborhoods were more vulnerable to heat exposure because they had fewer social and material resources to cope with extreme heat. Urban heat island reduction policies should specifically target vulnerable residential areas and take into account equitable distribution and preservation of environmental resources.

Adolescent↗
PubMed2003

The vulva skin microclimate: influence of panty liners on temperature, humidity and pH.

Many women use panty liners between menstrual periods. The aim of this study was to investigate whether the use of such products might influence the vulva skin. Twelve healthy women were studied on four occasions with three different product constructions and on one occasion without products. Temperature, surface wetness and surface pH were measured on vulva skin. Mean skin temperature when the women were wearing a conventional panty liner (with a non-breathable back sheet) was 35.9 degrees C, compared to 34.4 degrees C when wearing no panty liner at all (p < 0.01) and 34.5 degrees C when using a panty liner with a breathable (i.e. vapour permeable) back sheet (p < 0.01). Skin humidity was significantly higher when the conventional panty liner was used compared to no panty liner or to the breathable panty liner (both cases p < 0.01). The mean pH value at the exterior aspect of the labium majus was 5.8 with the conventional panty liner, 5.2 with no panty liner and 5.3 with the breathable panty liner (p < 0.001 and p < 0.01, respectively). The results indicate that the conventional panty liner changes the vulva skin microclimate, but that the breathable panty liner to a substantial degree keeps the microclimate at an undisturbed level. The actual effect of these differences on microbiological flora will be addressed in a subsequent study.

Adult↗
PubMed1996

Microclimate-dependent survival of unfed adult Ixodes scapularis (Acari:Ixodidae) in nature: life cycle and study design implications.

Microclimate and other abiotic factors may be important in determining the survival of arthropod vectors, yet the impact of such variables rarely has received careful examination. The impacts of habitat, microclimate, and experimental confinement on survival rates of unfed adult blacklegged ticks, Ixodes scapularis Say, were studied in field enclosures in southcentral and northwestern Connecticut. At both locations, 2 enclosures were placed in each of 3 different habitats (field, forest canopy, and forest/field edge). Forty wild-caught adult ticks (20 males, 20 females) were placed in each enclosure. At one site, another 40 ticks were confined to nylon mesh bags placed inside each enclosure. Soil temperature, ground-level air temperature and relative humidity were measured within each habitat. The number of ticks surviving within each enclosure was monitored 1 or 2 times per week. Ticks that were confined in nylon bags had a lower survival rate than ticks that were able to move freely within the enclosures. Ticks survived longer in edge and forest habitats than in open fields, which were characterized by greater extremes in air temperature, soil temperature, relative humidity, and vapor pressure deficit than the other 2 habitats. The mean daily survival rates of free-ranging I. scapularis were negatively related to air temperature, vapor pressure deficit, and the coefficient of variation of relative humidity.

Animals↗
PubMed1999

Microclimate and habitat in relation to Ixodes scapularis (Acari: Ixodidae) populations on Long Point, Ontario, Canada.

The impact of microclimate and density of hosts for adult ticks on the density of Ixodes scapularis Say was evaluated within 4 habitats on Long Point, Ontario, from 1989-1992. During the period from May to September, mean weekly vapor pressure deficits were greater within the oak savannah and cottonwood dune habitats than at the maple forest and white pine habitats, which were similar. Vapor pressure deficit was likely the major factor affecting the survivorship of eggs and immature tricks in these habitats. Based on drag sampling, I. scapularis adults demonstrated peak activity in April and October of each year. The mean number of I. scapularis adults collected by dragging during the fall or in the spring did not differ significantly within each habitat. The mean number of adults collected also did not differ among tick cohorts within each habitat; however, significantly more adults were collected within the maple forest than in the white pine habitat. The mean number of I. scapularis adults per white-tailed deer, Odocoileus virginianus (Zimmerman), increased from 1989 to 1991 and then decreased in 1992. Significantly more adult I. scapularis infested deer were observed in 1990 than in 1989. Removal of deer in 1989 and 1990 resulted in a calculated decrease of > 100,000 fed female ticks. Although seasonal variation in microclimate within habitats was closely linked with tick survival and partly explains the differences in abundance of I. scapularis among habitats on Long Point, habitat utilization by deer was also a primary factor governing the local abundance of I. scapularis populations.

Animals↗
PubMed1999

Maintenance and regulation of the pH microclimate at the luminal surface of the distal colon of guinea-pig.

1. The fluorescent dye 5-N-hexadecanoyl-aminofluorescein (HAF) was used to study the mechanisms involved in maintaining a relatively constant luminal surface pH (pHs) in the distal colon of the guinea-pig. The fatty acyl chain of the HAF molecule inserts into the apical membrane of epithelial cells. This allows a continuous measurement of the surface pH for several hours. 2. The localization of HAF was confirmed by confocal laser-scanning microscopy and by using monoclonal antibodies against fluorescein. The insertion of HAF into the apical membrane of the colonocytes did not change the transepithelial conductance or the short-circuit current of the epithelium. 3. With the HAF method a pH microclimate was confirmed at the colonic surface. Although the pH of the bulk luminal solution was decreased in bicarbonate-containing solution from 7.4 to 6.4 the pHs changed only in the range 7.54-6.98. 4. In the absence of bicarbonate pHs almost followed changes of bulk luminal pH. In the presence of bicarbonate there was a decrease in pHs after removal of chloride from the luminal side and an increase in pHs after addition of butyrate to the luminal solution. This suggests the involvement of a bicarbonate-anion exchange in bicarbonate secretion: a Cl--HCO3- as well as a short-chain fatty acid--HCO3- exchange. 5. The apical K+-H+-ATPase in the distal colon of guinea-pig has little influence on pHs in the presence of physiological buffer concentrations. 6. Our findings indicate that bicarbonate plays a major role in maintaining the pH microclimate at the colonic surface.

Animals↗