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1.
The present investigation is a retrospective review of snake bites in Riyadh province over the period (2005–2010). A total of 1019 cases of bites admitted to the Ministry of Health medical centers in Riyadh province were analyzed on the basis of age, sex, time of bite and its site on the body, outcome of treatment, antiserum dose and type of snake. Bites occurred throughout the six years with the highest frequency in 2005 and least in 2006 where most of the bite cases were mild and all evolved to cure except four patients who died following the administration of antivenom during 24 h after snake bite. Most of the patients were males (81.7%) and the most attacked age was within the range of 11–30 years (51.5%). All the bites were mainly in the exposed limbs and the most frequently bitten anatomical regions were the lower limbs (427 cases, 41.9%), principally the feet. The study incriminates Cerastes cerastes gasperettii in most of the bites indicating it as the snake of medical importance in Riyadh province. Also, the study indicates low degree of threat in spite of high rate of snake bites as a result of the availability of the medical facilities and the antivenin use in medical centers in Riyadh province. 相似文献
2.
In the past, Pneumocystis jiroveci (formerly P. carinii) belonged to the Protozoa group, but the studies on structure of the cell wall and nucleotide sequence resulted in the reclassification of this organism in the kingdom Fungi. P. jiroveci is an opportunistic pathogen, responsible for pneumocystis pneumonia with frequent complications of immunocompromised patients. Delayed initiation of appropriate therapy increases the risk of death in immunocompromised patient. The aim of this work was to determine the prevalence of P. jiroveci from patients suspected of having respiratory tract infections in southwestern Slovakia over a 10-year period. Due to the increasing number of immunosuppressed persons, the diagnostic of P. jiroveci in patients with pulmonary complications is essential to improve recovery onsets. Effective diagnosis is currently based on microscopic examination and detection of parasite DNA by polymerase chain reaction (PCR) in bronchoalveolar lavage (BAL) and induced sputum. In total, 386 clinical samples originated from patients suspected of pneumocystis infection were tested within ten years. Requirements for diagnosis of the pathogen were growing during the period. Three hundred and sixteen BALs, 59 induced sputa, 10 lung biopsies and 1 liquor were subjected to the detection of P. jiroveci. P. jiroveci DNA was detected in 30 patients using PCR, but cysts of microorganism were present only in 4 cases by microscopy. The pathogen was confirmed in 24 BALs and 6 sputa samples. The presence of P. jiroveci has been demonstrated mainly in immunocompromised individuals with cancer (20), but also in patients with pneumonia (6+1 HIV), with unspecified parasitic diseases (1+1HIV) and with systemic lupus erythematosus (1). 相似文献
3.
PurposeCalifornia is the largest US producer of processing tomatoes, generating 96% of all domestic production and nearly 30% of global supply. Processing tomatoes are mostly processed into diced and paste products. Consumers and actors along their supply chains are increasingly interested in understanding their environmental burdens and identifying opportunities for improvements. This study applies life cycle assessment (LCA) to California diced and paste products over a 10-year timeframe to characterize current impacts and historical trends. MethodsThe LCA considers a scope from cradle-to-processing facility gate and accords with relevant Product Category Rules as published by the International EPD® System. Extensive primary data were collected for tomato cultivation for the years 2005 and 2015, and from processing facilities for 2005, 2010, and 2015 to understand the effects of evolving practices and technologies. We estimate crop and regional specific nitrous oxide and nitrate leaching emissions using a biogeochemical model, and the USES-LCA model is used to determine potential impacts from pesticide application. A suite of impact assessment categories is included based on the CML method (only global warming potential and freshwater consumption values are in the abstract). Results and discussionThe 2015 results of the study indicate that diced tomatoes are responsible for 0.16 kg CO2e and 71 L of freshwater per kg, and paste is responsible for 0.83 kg CO2e and 328 L of freshwater per kg. The main opportunities for improvement include natural gas use in the greenhouse phase, energy for irrigation pumping and fertilizer type in the cultivation phase, and natural gas and electricity use in the facility processing phase. These hotspots are consistent with studies of processing tomato in other parts of the world. Evaluating trends over time showed that technological improvements in the industry had reduced life cycle impacts; for example, global warming potential decreased by 12% for paste and 26% for diced products between 2005 and 2015. ConclusionsTrends over time show increasing efficiency at the cultivation and processing facility stages that have led to reductions in all impact categories evaluated. However, additional opportunities exist beyond efficiency improvements. Fertilizer and pesticide choice are potential opportunities for further reducing impacts. Also, the introduction of renewables in each phase of the supply chain (solar-powered irrigation pumps and onsite solar energy generation for facilities) could reduce the overall supply chain GWP100 impacts by 9–10%. 相似文献
4.
Lake Vesijärvi was loaded by sewage from the City of Lahti for 60 years until 1976 when the discharge was diverted. Paleolimnological analyses of the varved bottom sediment indicate that the sedimentation rate within the Enonselka basin, the most eutrophic part of the lake, has been as high as 2 cm yr –1, and total phosphorus accumulation was 20–40 g P m –2 yr –1, during the last 20 years. Within the less eutrophic Laitialanselkä basin, the sedimentation rate did not exceed 1 cm yr –1, and the formation of varved sediment only began at the end of the 1960's, i.e. about 10 years later than in Enonselkä.Planktonic diatom production was highest in the Enonselka basin. The most abundant diatoms in the sediment between 1970–1985 were Asterionella formosa, Aulacoseira islandica and Stephanodiscus spp. Fragilaria crotonensis and Tabellaria fenestrata had low abundances in the middle of the 1970's but increased again at the end of the 1970's. Asterionella formosa and Diatoma elongatum reached their maxima between 1979–1984 when the hypolimnion of the Enonselk/:a basin was aerated artificially. In the Laitialanselkä basin, the production of planktonic diatoms has been lower and the species composition of the diatom community differed from that in Enonselkä. However, at the end of 1980's the total accumulation of diatoms in Laitialanselkä approached levels which were observed at the end of 1950's in Enonselkä, prior to the rapid eutrophication period.The production and thereby the sedimentation of diatoms has decreased towards the end of the 1980's in Enonselkä, indicating reduced nutrient availability in the lake water. This reduction was due to the decreased external loading of phosphorus as well as to the decreased release of phosphorus from the sediment as a result of improved oxygen balance in the hypolimnion. 相似文献
5.
The hawk–dove game famously introduced strategic game theory thinking into biology and forms the basis of arguments for limited aggression in animal populations. However, aggressive ‘hawks’ and peaceful ‘doves’, with strategies inherited in a discrete manner, have never been documented in a real animal population. Thus, the applicability of game-theoretic arguments to real populations might be contested. Here, we show that the head-colour polymorphism of red and black Gouldian finches ( Erythrura gouldiae) provides a real-life example. The aggressive red morph is behaviourally dominant and successfully invades black populations, but when red ‘hawks’ become too common, their fitness is severely compromised (via decreased parental ability). We also investigate the effects of real-life deviations, particularly sexual reproduction, from the simple original game, which assumed asexual reproduction. A protected polymorphism requires mate choice to be sufficiently assortative. Assortative mating is adaptive for individuals because of genetic incompatibilities affecting hybrid offspring fitness, but by allowing red ‘hawks’ to persist, it also leads to significantly reduced population sizes. Because reductions in male contributions to parental care are generally known to lead to lower population productivity in birds, we expect zero-sum competition to often have wide ranging population consequences. 相似文献
6.
Species composition of the understory of spruce (Picea abies (L.) Karsten) and beech (Fagus sylvatica L.) forests subjected to intense air pollution stress in the Krkonoe Mts., Czech Republic, showed directional changes over the last 15 years. The changes were documented with repeated observations of 29 permanent plots, initiated in 1980 and analysed with constrained ordination methods (Canonical Correspondence Analysis). Ground layer changes were mainly associated with the loss of canopy foliage from air pollution stress. The increased amount of the light at ground level resulted in increased herb cover. The initially dominant species (e.g., Calamagrostis villosa (Chaix) J. F. Gmelin, Deschampsia flexuosa (L.) P. B., Vaccinium myrtillus L., Athyrium distentifolium Tausch) were those that increased in cover. Moss cover, and moss and herb richness, declined over the course of the study. Thus, the changes in tree canopy are accompanied with changes in the forest understory, which in turn can affect the dynamics of these forests. 相似文献
7.
This study was carried out over a 2-year period (2001 and 2002) with the aim of identifying the fungal population in the aerosol of the Southern city of Caxias do Sul, RS, Brazil. Sampling was performed using Hirstȁ9s non-viable volumetric method. Our results show the presence of a large number of fungal spore types, a total of 41. Three groups were predominant: Deuteromycotina, Ascomycotina and Basidiomycotina. In 2001, Deuteromycotina taxa represented 44.61% of the total annual spore counts, with the largest concentration occurring in the fall (58,637 spores); in 2002, it represented 40.03% of the total annual spore counts, and the largest concentration was obtained in the summer (68,317 spores). Ascomycotina was present at the same level (24.5%) in both years of sampling, and the highest concentrations were found out in the summer (2001: 42,183 spores; 2002: 29,461 spores). Basidiomycotina represented 22.37% of the total annual spore counts in 2001, and 20.41% in 2002, with the largest concentrations found in the summer (2001: 35,988 spores; 2002: 30,212 spores). The most frequent fungi found during the study period were Cladosporium, Coprinus, Leptosphaeria, Aspergillus/Penicillium and Ganoderma. Permanent aerobiological monitoring would be necessary to detect associated environmental variations. 相似文献
8.
The implantation of cardiac pacemakers has become a well-established therapy for conduction disorders and sinus node dysfunction. In many countries pacemaker registries have been initiated in order to collect information on patient characteristics, trends in numbers and the types of pacemakers used, to identify problematic devices, and for safety monitoring. For this utilisation study the Central Pacemaker Patients Registration (CPPR) from the Netherlands Pacemaker Registry Foundation (CPPR-SPRN) containing data collected for more than 20 years was used. During this period nearly 97,000 first pacemakers were implanted. Analyses show an increase in the rate of implanted devices. The change in pacemaker type from VVI to DDD, followed by biventricular stimulation, is reflected by the number of simultaneously implanted leads, which is partly a consequence of cardiac resynchronisation therapy. Our data demonstrate that indications for implantation and type of pacemaker are comparable with other European countries. 相似文献
9.
High efficiency particulate arrestance (HEPA; 99.97% efficient at 0.3 m) filters, filters with ASHRAE particulate arrestance rating of 90–95% at 1 m (90–95% filters), and lower efficiency cellulosic-polyester filters from air conditioning systems in hospitals and commercial buildings were removed from the systems and examined microscopically for mold colonization. Cellulosic-type filters from systems with water entrainment problems typically were colonized, or became colonized upon incubation in moisture chambers. Species of Acremonium, Aspergillus, and Cladosporium were most common. With air filters of all types, treatment of filter media with an antimicrobial preservative tended to reduce or delay colonization. Mold colonization of HEPA and 90–95% filters was observed most often on the load surfaces, but two untreated HEPA filters were permeated with fungi, one with Aspergillus flavus, the other with Cladosporium sp. Air filters in heating, ventilating, and air conditioning (HVAC) systems, particularly those with chronic or periodic exposure to moisture, may serve as point sources for indoor molds. 相似文献
11.
We studied the effects of soil temperature (7, 15, and 25°C) on the growth and photosynthesis of seedlings of the Japanese
larch ( Larix kaempferi) and its hybrid larch ( L. gmelinii × L. kaempferi) to simulate early stages of regeneration after disturbance. At a soil temperature of 7°C, the root length per unit root
biomass, chlorophyll concentration, and photosynthetic nitrogen-use efficiency (PNUE) were markedly lower in the Japanese
larch than in the hybrid larch, which may indicate that the hybrid larch is better at acquiring water and nutrients. At ambient
temperatures of 17–25°C, the light-saturated photosynthesis rate ( P
sat) of both seedlings grown at a soil temperature of 7°C was lower than at 15 or 25°C. By the 16th week, the needle area, root
area, and biomass in seedlings of both types were lower at a soil temperature of 7°C than at soil temperatures of 15 or 25°C.
At a soil temperature of 25°C, P
sat and nitrogen uptake were lower in both larch species than at 15°C. The growth of the Japanese larch declined sharply from
15 to 25°C; however, the growth of the hybrid larch decreased only slightly from 15 to 25°C. We conclude that an increased
soil temperature may retard larch growth in cold regions, especially in the case of the Japanese larch. 相似文献
12.
During the extremely dry period between 2000 and 2003, the water level of Lake Balaton decreased by 82 cm and 80% of the stony littoral, an important habitat for the zebra mussel ( Dreissena polymorpha), became dry. A recovery period started in 2004 due to intense precipitation, which increased water levels in the lake. Seasonal and spatial variations of the relative abundance, population density, population structure and biomass of the zebra mussel and the relative abundance of the amphipod Chelicorophium curvispinum were monitored in the period of 2003–2005 at four different shoreline sections and in two different portions (on the bottom and near the surface portion of the rip-rap) of Lake Balaton. Along with these studies, a quantitative survey of mussel larvae found in the plankton and of the abundance of mussel feeding diving ducks were made. As a consequence of the water level fall, on the dried part of the stony littoral, numerous zebra mussel druses perished. Following the dry period in early 2004, the relative abundance of the mussel on the bottom stones was smaller than in 2003 and the bottom community was dominated by C. curvispinum. By the end of 2004 and during 2005, the water level returned to normal and the surfaces of the reinundated stones were conducive to the successful colonization of zebra mussels. Hence, they returned as the dominant fauna in 2005. The stones near the surface might provide a new substrate for the recruitment of zebra mussels, probably offering more suitable substrata for the settlement in 2005 than in 2003. Therefore, the new substrata available in 2005 may have encouraged better and more rapid zebra mussel colonization than before. Zebra mussels may be better competitors for new space than C. curvispinum. A minor change of water-level fluctuation in 2005 and the reduction in population size of the mussel feeding waterfowl could have contributed to the intensive spread of zebra mussel by 2005. 相似文献
13.
Background: This study aimed to investigate the incidence trends of colorectal cancer by sex and subsite, in East Anglia from 1971 to 2005. Methods: Using data from the Eastern Cancer Registration and Information Centre, we examined the time trends and the effect of age, period of diagnosis and birth cohort on the incidence of colorectal cancer by sex and subsite. Results: Between 1971 and 2005, 23 875 males and 22 651 females were registered with colorectal cancer in East Anglia. During this period, the increase in the incidence trends was higher among males, more recent periods of diagnosis, and proximal colon. Cohort effects were statistically significant in distal and rectal cancers in males ( p < 0.001 and p = 0.05, respectively), and in proximal colon in females ( p < 0.001). Period effects were statistically significant across all subsites and both sexes ( p < 0.001 for all). Conclusions: Period effects were significant across all subsites for both sexes, whereas cohort effects varied in their significance levels depending on subsite and sex. We suggest that the period effect may be due to an increase in the use of colonoscopy for diagnostic or opportunistic screening, and the cohort effect may be due to aetiological differences in CRC between sexes and subsites. 相似文献
14.
Discrete variability of four P. percae characters of the main cestode functional complexes was identified. Phenotypic diversity of P. percae from different parts of the distribution range was analysed. Research revealed low geographic variability and high stability of the dominant variations in combination with morphometric plasticity. The conclusion was made that the patterns of P. percae morphological variability were shaped by the common fate and long-standing co-evolutionary relations between the parasite and the host--the perch Perca fluviatilis. 相似文献
15.
We studied a congeneric species pair that shows very different abundances in Estonia — Viola elatior occurs in only five localities in mesic calcareous grasslands, while Viola mirabilis is abundant in mesic calcareous grasslands and forests all over the country. Both species were sown in patches of mesic calcareous grassland, in clipped and untreated plots. Both species were established successfully after sowing, indicating that they both may be dispersal limited to the same extent. V. elatior showed higher fecundity in the second year than V. mirabilis. V. elatior was more sensitive to the availability of light. In the first year, V. elatior established more successfully in clipped plots than V. mirabilis. In the second year, the number of established V. elatior individuals decreased in unmanaged plots, where competition for light was more severe. Since many calcareous grasslands in Estonia have been abandoned and the standing crop, as well as the cover of shrubs and trees, has increased, sensitivity to light competition may be one reason why V. elatior has become more rare. It cannot be the only reason for its rarity in the whole region, since many other grassland species that are vulnerable to reduced light in overgrown unmanaged grassland communities still occur in much higher numbers in the country. It was hypothesised that historical factors, e.g. relatively late arrival in the region, may also be behind the rarity of V. elatior. 相似文献
16.
Pollen counts in Burgundy were monitored by means of four Hirst volumetric traps. Their analysis revealed a sharp rise of Ambrosia from 1996 to 1997. The minimum amount of ragweed pollen likely to provoke allergies (13 grains m–3) was reached or exceeded several days every year, but without leading to clinical symptoms. The circadian variation of Ambrosia pollen showed two peaks: the first one in the morning was suggested to coincide with local pollination, although the second one, in the afternoon, seemed to result from a long range transport which was confirmed by the study of wind roses. 相似文献
17.
Tree community structure and dynamics of a 5.8 ha fragment of montane semideciduous forest in south-eastern Brazil are described based on two successive surveys of trees with dbh 5 cm carried out in 1987 and 1992 in 126 20 × 20 m quadrats. The main purpose was to assess whether the spatial variation of dynamic and structural variables were related to edge-effects and past disturbance regimes. The totals for the two surveys were, respectively, 6528 and 6770 trees, and 94.89 and 108.53 m 2 of basal area. The forest fragment was at an aggrading sylvigenetic phase, indicated by an overall net increase in density and basal area, and by a declining proportion of trees of smaller size. The overall annual mortality and recruitment rates were 2.6% and 3.0%, respectively. The dynamic process, however, was strongly affected by spatial heterogeneity. The more severely disturbed sectors had lower average canopy heights and basal areas per hectare, and higher tree densities, proportions of smaller trees, and relative area of canopy gaps. They also had higher mortality and recruitment rates, resulting in higher turnover rates compared to the sectors which suffered only moderate disturbance regimes. Edge sectors were also affected by different past disturbance regimes. However, they stood out by having a particularly high frequency of liana tangles and the highest rates of net increase both in density and basal area. A canonical correspondence analysis indicated that the effects of past disturbance regimes and edges were highly related to the species distribution in the area. Pioneer species were concentrated on the edges and more severely disturbed sectors, shade-tolerant species were particularly more abundant on the moderately disturbed sites, while light-demanding ones were more widely distributed. Tree community structure was also undergoing important changes, with less common species enjoying higher recruitment rates and density increase compared to the more common ones. Shade-tolerant species were increasing in relative abundance and had comparatively lower mortality rates and higher recruitment rates. On the other hand, pioneer species were under retreat, with a decreasing relative abundance, higher mortality rates and lower recruitment rates.Nomenclature: Oliveira-Filho et al. 1994a,d. 相似文献
18.
Pollen of grasses (Poaceae) is one of the most important airborne allergen sources worldwide. The aim of the study was to determine diurnal, day‐to‐day, weekly, monthly and annual pollen variation, and the effect of selected meteorological parameters on atmospheric pollen concentrations in Zagreb. A preliminary study was carried out during four seasons (2002 – 2005), using a 7‐day VPPS 2000 Hirst volumetric pollen trap. Total annual grass pollen concentrations in Zagreb were constant (2 673 – 3 074 p.g.m ?3), with a relative drop in 2004 (1 196 p.g.m ?3). The beginning of the grass pollen season is usually observed when the average daily temperature exceeds 13.5°C (max. daily temp. 19.5°C), without precipitation. In all four study years the absolute peak of concentrations occurs in the second half of May. The length of pollen season during the study period was 157 – 173 days. A high variability was observed in the maximal concentration and in the number of days when grass pollen concentration exceeded the threshold value of 30 p.g.m ?3 (9 – 40 days). Statistically significant correlations were found between airborne grass pollen concentrations and air temperature, level of precipitation and relative humidity. 相似文献
19.
International Journal of Biometeorology - 相似文献
20.
Changes in species composition and density of trees >10 cm gbh in a tropical dry evergreen forest in Puthupet, south India are interpreted for the period between 1992 and 2002. A 1-ha plot was inventoried in 1992 and was recensused in 2002. During the 10-year interval tree taxa diversity as well as stand density increased, but the basal area value decreased. Tree species richness increased by 21% (from 24 to 29 species) by an addition of eight species and local extinction of three species. The tree density increased just by eight individuals (from 1330 stems ha −1 in 1992 to 1338 ha −1 in 2002), but the basal area decreased by 8% (from 37.5 to 34.5 m 2 ha −1). Many species (11 numbers) have increased in abundance rather than decreased. Many surviving species seem to have considerable stability in abundance at the local scale. The density of smaller stems (10 29 cm gbh) increased by 15.3%, while that of the larger trees decreased drastically (81.6%). Ninety percent of the missing stems were from the middlestorey of the forest. Tree density changes among the three ecological guilds revealed a decrease in stem density and an increase in basal area in the lowerstorey; while the middlestorey exhibited a reverse trend. Family-wise, tree density changes revealed that the majority of families (67%) showed an increase in stem density. Long-term studies on tree population changes are essential to estimate tree mortality and recruitment rates, which will provide a greater insight in tropical forest dynamics. 相似文献
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