首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
We report changes after frost in cerrado species populations and community structure in Assis, São Paulo State, Brazil and consider the possible impacts of frost on cerrado types and their distribution. Four permanent plots (10 m × 10 m) were established and 736 individuals were marked with enumerated plastic labels and measured one week after the frost. Frost damage for each individual was assessed: 0 - not affected; 1 - slightly affected; 2 - substantially affected; and 3 - strongly affected. The frost impact on vegetation structure was high, reducing tree canopy cover from 88% to 19% in the upper stratum and that of the lower stratum from 48% to 8.5%. Floristic richness did not change, even though a small number (3%) of individuals of some species died. Conversely, the relative dominance of species changed dramatically in the short-term because of varying susceptibility to frost of different species. The largest reductions in crown cover were observed in Xylopia aromatica and Vochysia tucanorum. Of the 57 species recorded, 15% were unaffected, 19% had only their leaves damaged, 25% had some of their leaves and branches damaged, and 41% had all their aerial parts killed. The majority of individuals in the community belonged to frost tolerant species. The regeneration of the stand structure was remarkably rapid; height and canopy cover of the lower stratum recovered completely after five months, and those of the arboreal stratum showed a recovery of about 80% after 11 months. We consider that the frequency and intensity of frosts can maintain more open forms of cerrado vegetation even in sites where both water and nutrient availability could support denser vegetation. It is also probable that some frost-resistant heliophyte species are confined to areas where frosts prevent the development of denser cerrado vegetation. Much of the characteristic floristic composition of the southern region of the cerrado biome may be related to the selection of frost-resistant species. Our study shows, however, that a full complement of cerrado plants is capable of occupying and colonizing frost susceptible sites.  相似文献   

2.
Benthic annelid communities were studied during a one-year period (August/95 to July/96) in two sectors of the beaches Engenho d'Agua and S?o Francisco, S?o Sebasti?o Channel (S?o Paulo, Brazil), where the substrate is composed by a mixture of sand and rock fragments. Abiotic parameters such as salinity of interstitial water and sediment properties were used to characterize the environment. The polychaetes were well represented in the two sectors and their distribution was related with sediment type. The density of individuals and the number of taxa was higher at S?o Francisco, while the diversity and the evenness were higher at Engenho d'Agua. This difference can be a consequence of organic enrichment caused by domestic input, and of the lower and more variable salinity at S?o Francisco. Due to these factors, the high density of opportunistic species, like Capitella capitata ssp., Scolelepis squamata, Laeonereis acuta and several oligochaetes, represented 75.5% of total abundance at this sector.  相似文献   

3.
Faunal inventories are extremely important, especially when focused on neglected groups, such as echinoderms, and concentrated on areas under intense anthropic activity such as the SAo Sebastilo Channel in Brazil (23 degrees 41' - 23 degrees 54' S and 45 degrees 19' - 45 degrees 30' W). Intertidal and upper sublittoral zone collections were performed at five sites of the Channel's continental margin from May to August 2001. The rocky substrate down to 19 m deep was surveyed by snorkeling and SCUBA diving from August 2002 to May 2004, on both margins of the Channel: continental (14 sites) and insular (10 sites). We report a total of 38 species of echinoderms (one Crinoidea, nine Asteroidea, 13 Ophiuroidea, nine Echinoidea and six Holothuroidea). Seven of those species have been recorded here for the first time for the Channel (four Asteroidea, two Ophiuroidea and one Echinoidea).  相似文献   

4.
In order to determine the epidemiology of tinea cruris in São Paulo, Brazil, an investigation was carried out from April 95 to March 1997. A total of 2000 individuals were studied, of whom 105 were suspected of having tinea cruris infection. Direct microscopy and/or culture were positive in 66 [62.8%] of the cases. Erythematous-scale plaques and erythematous-liquenificated plaques were the most frequently found clinicaltypes. T. rubrum was the prevalent dermatophyte in 90% of the cases, followed by T. tonsurans (6%) and T. mentagrophytes (4%).  相似文献   

5.
The capybara (Hydrochaeris hydrochaeris) is a large rodent used for human consumption in certain areas of South America. In the present study, viable Toxoplasma gondii was isolated for the first time from this host. Antibodies to T. gondii were assayed in the sera of 64 capybaras from 6 counties of S?o Paulo State, Brazil, using the modified agglutination test (MAT, > or =1:25 dilution) and the indirect fluorescent antibody test (IFAT, > or =1:16 dilution), and antibodies were found in 48 (75%) by MAT, and 49 (76.6%) by IFAT. Samples of brain, heart, and tongue of 40 seropositive capybaras were pooled, digested in pepsin, and bioassayed in mice. Toxoplasma gondii was isolated from tissue homogenates of 36 capybaras, and the isolates were designated TgCyBrl-36. Most isolates were lethal to mice; 17 of the 36 isolates killed 100% of infected mice, 11 isolates caused mortality in 25-90% of infected mice, and 8 isolates were nonpathogenic to mice. Results indicate that asymptomatic capybaras can harbor mouse-virulent T. gondii, and hence they can serve as a source of infection for humans.  相似文献   

6.
New records and distributional notes are provided for Reserva Ecológica Michelin, an Atlantic Forest fragment near the southern coast of Bahia State, Brazil. Two families, four genera and five species are recorded for the first time in Bahia State. Additionally, one family, two genera and three species are also recorded for the first time in the Northeast Region of Brazil, resulting in nine families, 48 genera and 96 species recorded to this region. Amongst the recorded species, Hermanella mazama (Nascimento, Mariano, and Salles, 2012) has been classified as an endangered species on the official Brazilian red list.  相似文献   

7.
The incidence of cases of dermatophytosis in dermatology outpatient departments has increased in recent years. Infection control is essential to prevent transmission, and accurate diagnosis of this type of infection is important to avoid confusion with other dermatological processes caused by non-fungal agents. The objective of this study was to determine the incidence of dermatophytosis and its etiological agents in a public hospital of São Bernardo do Campo, Brazil. From February 2005 to May 2006, 273 samples were collected from 191 patients in a public dermatology outpatient department. The samples were collected according to conventional methods used in clinical mycology and direct examinations and cultures were performed. Of the samples suspected of fungal infection, 19% produced positive cultures, and the largest number of samples was from female patients between 31 and 40 years old. The most commonly infected area was the toenails, and the most common infective agents according to microscopic analysis and biochemical tests were the Candida species, which were responsible for 61.6% of the infections. These data agree with findings reported in the literature indicating a lower prevalence of filamentous fungi, such as Epidermophyton, Trichophyton, and Microsporum, in dermatomycosis.  相似文献   

8.
The 957‐ha forest at the Estação Biológica de Caratinga/Reserva Particular do Patrimônio Natural‐Felìciano Miguel Abdala, in Minas Gerais, Brazil, supports one of the largest known populations of the critically endangered northern muriqui (Brachyteles hypoxanthus). We combine long‐term data on one group that has been monitored since 1982 with new data obtained on the other three groups since 2002 and 2003 to describe the demographic structure of this population, evaluate its potential for future growth, and predict how dispersal and competitive regimes may change in response to current demographic conditions. As of January 2005, the 226 individuals in the population were divided into four mixed‐sex groups with 37–77 members, and an all‐male unit whose eight males maintained transient associations with two of the mixed‐sex groups. Although 51.77% of the population was female, the sex ratio among adults and subadults was female‐biased (0.75), while that among immatures was male‐biased (1.47). Consistent with expectations from mean interbirth intervals, 64.18% of adult females gave birth in 2003 and 2004. However, by January 2005, only 52.31% of adult females were still carrying infants <24 months of age due to unusually high infant mortality. First‐year survivorship among the 25 infants born in the population in 2003 was only 76%, considerably lower than previously documented in the longest‐studied group. High female fecundity is indicative of a healthy population, but the current male bias in births will result in a decline in the population growth rate within two decades, and may increase levels of male reproductive competition and alter dispersal patterns. Am J Phys Anthropol, 2006. © 2005 Wiley‐Liss, Inc.  相似文献   

9.
Capybara (Hydrochaeris hydrochaeris) is a large rodent distributed throughout tropical America. Antibodies to Neospora caninum in 213 feral capybaras from 11 counties of the State of S?o Paulo, Brazil, were assessed using the indirect immunofluorescent antibody test (titer >or=1:25) and found in 20 (9.4%), with titers of 1:25 in 4, 1:50 in 7, and 1:100 in 9 animals. This is the first report of occurrence of N. caninum antibodies in capybaras.  相似文献   

10.
We conducted monthly snail captures in Bananal, State of S?o Paulo, Brazil, between March 1998 and February 2001, to identify Schistosoma mansoni vectors, estimate seasonal population changes, and delimit foci. We also evaluated the impact of improvements in city water supply and basic sanitation facilities. We identified 28,651 vector specimens, 28,438 as Biomphalaria tenagophila, 49 of them (0.2%) infected with S. mansoni, and 213 as B. straminea, none of the latter infected. Vectors predominated in water bodies having some vegetation along their banks. Neither population density nor local vegetation could be linked to vector infection. We found the first infected snails in 1998 (from March to May). Further captures of infected snails ocurred, without exception, from July to December, when rainfall was least. Irrespective of season, overall temperature ranged from 16.5 degrees C to 21 degrees C; pH values, from 6.0 to 6.8. Neither factor was associated with snail population density. Frequent contact of people with the river result from wading across it, extracting sand from its bottom, fishing, washing animals, etc. Despite a marked reduction in contamination, cercaria shedding persists. Whatever the location along its urban course, contact with river Bananal, particularly of the unprotected skin, entails risks of infection.  相似文献   

11.
Forty-four stream segments were sampled from May to October in 1992 and 1993 in the northwest region of São Paulo State, southeastern Brazil (19°45–21°25S, 49°05–51°30S). Thirty-six macroalgal subgeneric taxa were found and Chlorophyta was the dominant algal group (47% species), followed by Cyanophyta (33.5%), Rhodophyta (14%) and Chrysophyta (5.5%). The most widespread species wereStigeoclonium helveticum (25% sites),Batrachospermum delicatulum andCompsopogon coeruleus (20.5%). Distribution was patchy, with species number per sampling site ranging from 0 to six (3.1 ± 1.7) and correlated positively with species abundance. Species cover ranged from 0 to 61% of the stream bottom (19.1 ± 19.7%). Most sites (57%) were dominated by one or two macroalgae species. No significant difference was found between the frequency distribution of variables measured for streams and for total macroalgae, but the most widespread species differed for most parameters and occurred over wider ranges of environmental conditions. Mean species number and abundance were close to values found in distinct regions or biomes of North America. Higher conductance and lower oxygen values, as well as rocky substrata, generally constituted the most favourable combination of conditions for the development of macroalgae in the region. The pattern of strong dominance of few species was considered to be typical for stream macroalgal communities in general.  相似文献   

12.
São Paulo is the most developed state in Brazil and little of its native vegetation remains. In Luiz Antonio and Santa Rita do Passa Quatro municipalities, only small fragments of cerrado (Brazilian savanna) physiognomies (cerradão, cerrado sensu stricto) and of semideciduous forest have been left, surrounded by eucalyptus silviculture and sugar-cane agriculture. However, that vegetation mosaic still shelters large mammals, including several carnivore species. To detect the carnivores present in such a mosaic area (50,000 ha), and to find out how they use the landscape, we recorded them through 21 camera traps and 21 track plots, during 18 months. Species richness, diversity and relative frequency were evaluated according to the habitat. Ten species were recorded, some of them locally threatened to extinction (Puma concolor, Leopardus pardalis, Chrysocyon brachyurus). Species diversity did not significantly differ among fragments, and although most species preferred one or another habitat, the carnivore community as a whole explored all the study area regardless of the vegetation cover; eucalyptus plantations were as used by the carnivores as the native fragments. Therefore, it seems possible to maintain such animals in agricultural landscapes, where some large native fragments are left and the matrix is permeable to native fauna.  相似文献   

13.
A total of 25 aphid species were collected from 49 ornamental plant species in S?o Carlos-S?o Paulo, Brazil; 12 aphids were monophagous, four oligophagous and nine polyphagous. A total of 58 aphid-plant associations are recorded, 43 unknown from Brazil. Eucarazzia elegans (Ferrari, 1872) (Aphididae: Aphidinae: Macrosiphini) is recorded for the first time from Brazil, and Nectandra megapotamica Spreng. (Lauraceae) is recorded for the first time as host plant for Lizerius tuberculatus (E.E. Blanchard, 1939) (Drepanosiphidae: Drepanosiphinae: Lizeriini). We also describe the injuries caused by aphids to the ornamental plants.  相似文献   

14.
Seeking to identify thrips species associated to peach and the injuries they cause, plants of Aurora and Tropic Beauty cultivars were weekly monitored, from May to August of 2005, in Holambra II district, in Paranapanema, SP. Flowers and fruits from six plants per hectare were sampled by the hitting technique. Frankliniella occidentalis (Pergande), F. schultzei (Trybom), F. gardenia (Moulton), F. condei John, F. insularis (Franklin) and Thrips tabaci Lindeman, in Thripidae, and Haplothrips gowdeyi (Franklin), in Phlaeothripidae were identified. F. occidentalis was dominant, comprising 55.7% of the total specimens sampled. Slight and severe injuries were registered in fruits.  相似文献   

15.
Gripopteryx from the Mantiqueira Mountains (South‐eastern Brazil), especially from Campos do Jordão, State of São Paulo, are considered. For G. cancellata (Pictet), G. reticulata Brauer, and G. garbei Navás new data and figures of adults are presented, and the nymphs are described. G. juetah sp.n., and G. pilosa sp.n. are described.  相似文献   

16.
Among the pests of cassava, the shoot fly, Neosilba perezi (Romero & Ruppell), is one of the most prevalent. It attacks mainly the terminal shoots and causes infested plants to produce lateral shoots. Reports on this species are rare or inexistent; thus, the purpose of this study was to assess three different areas for N. perezi infestation. The survey began in March 2008 and finished in February 2009. Fortnightly analyses were performed starting 45 days after planting, calculating the rate of infestation by N. perezi larvae in each study area. The areas were correlated separately for each parameter: fortnightly mean temperature, fortnightly mean rainfall, and plant age. The N. perezi larvae occurrence rate was higher in area 1 - which presented the highest population peaks in autumn and winter. There was only a single population peak in area 2, in winter; and area 3 presented the weakest population peak among the three, in November. The shoot fly population dynamics in the studied region is separately correlated to temperature, rainfall and plant age: temperatures above 23oC, relatively high rainfall and older plants seem to have a negative effect on populations of this insect.  相似文献   

17.
The occurrence of species of hermit crabs and their ecological distribution in soft bottoms off Ubatuba, São Paulo, Brazil were analyzed. To better understand the distribution of the species in relation to environmental factors, the similarity and species-diversity indexes were calculated. Paguroideans were sampled monthly from January through December 2000. The trawls were made with two otter-trawl nets at 13 different sites, at depths of 2–40 m. Water temperature, salinity, sediment texture, and organic matter content were measured. Gastropod shells occupied by hermit crabs were also assessed. A total of 1,238 specimens was collected, belonging to the families Diogenidae and Paguridae, comprising seven genera and thirteen species. The most abundant hermit crab species were Dardanus insignis (761 specimens) and Loxopagurus loxochelis (351 specimens). Phimochirus holthuisi is newly reported from the São Paulo coast. The highest diversity index was found for the shallower sites near rocky shores. The results of the grouping analysis for sites and species indicated three distinct groups for sites, and four groups for species. This suggests that the occurrence of these anomurans is associated with the environmental and biotic factors analyzed.  相似文献   

18.
The purpose of this study was to isolate fungi from the quarter milk of cow udders from several dairy herds and to identify the different genera and species involved in mastitis. A total of 2078 milk samples from normal, clinical and subclinical mastitis quarters from 22 dairy herds of 16 districts in the State of São Paulo, Brazil was utilized in this survey. Two hundred and fifty one (12.07%) fungi were isolated from the samples. Two hundred and eight of these (82.86%) were yeasts and 30 (11.95%) were moulds. The fungi were isolated in pure culture (24.77%) or in cultures mixed with bacteria (72.22%). The yeasts isolated were:Cryptococcus spp. (71 strains),Rhodotorula spp. (40),Candida spp. (68),Trichosporon cutaneum (21),Aureobasidium pullulans (7), andPichia ohmeri (1). Moulds classified in following genera were also isolated:Aspergillus (3),Penicillium (3),Alternaria (3),Phoma (3),Epicoccum (2), andGeotrichum (16).  相似文献   

19.
Fifty-two stream segments were sampled from 16 August to 13 September in 1993 in the eastern Atlantic Rainforest of S?o Paulo State, southeastern Brazil (22°55′–25°00′S, 44°48′–48°03′W). Forty-two macroalgal subgeneric taxa were found and the most widespread species were Audouinella pygmaea (21% of sites), Compsopogon leptoclados and Microcoleus subtorulosus (19%). Macroalgal species number per sampling site ranged from 0 to six (2.6 ± 1.7) and was positively correlated to species abundance, whereas species cover ranged from 0 to 70% of the stream bed (15.5 ± 20.8%). No significant correlation was found among macroalgal species number and abundance with any physical or chemical variable analyzed. Most sites were dominated by one or few macroalgal species, mainly, Audouinella macrospora, C. leptoclados and M. subtorulosus. No significant difference was found between the frequency distribution of variables measured for streams and for total macroalgae but the most widespread species (A. pygmaea) differed significantly for current velocity, specific conductance, turbidity and pH. Overall means for macroalgal occurrence include the following values: temperature (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiwaaaa!36CA!\[X\] = 19.9°C), current velocity (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiwaaaa!36CA!\[X\] = 45 cm s−1), oxygen saturation (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiwaaaa!36CA!\[X\] = 66%), specific conductance (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiwaaaa!36CA!\[X\] = 59.6 μS cm−1), turbidity (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiwaaaa!36CA!\[X\] = 5 NTU) and pH (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiwaaaa!36CA!\[X\] = 7.1). This pattern of patchy distribution and dominance by few species has been suggested as typical of stream macroalgal communities and has been ascribed to the rapid fluctuation of physical and chemical conditions. Total macroalgal species richness as well as mean species number per sampling site were considerably lower than found in similar studies of other regions. The Intermediate Disturbance Hypothesis was applied to explain these results: the same factor (high precipitation) responsible for the maintainance of the high species diversity in the surrounding forest can be, paradoxically, a constraint to the development of a more diverse macroalgal flora in streams.  相似文献   

20.
BackgroundPopulation-based cancer registry (PBCR) data provide crucial information for evaluating the effectiveness of cancer services and reflect prospects for cure by estimating population-based cancer survival. This study provides long-term trends in survival among patients diagnosed with cancer in the Barretos region (São Paulo State, Brazil).MethodsIn this population-based study, we estimated the one- and five-year age-standardized net survival rates of 13,246 patients diagnosed with 24 different cancer types in Barretos region between 2000 and 2018. The results were presented by sex, time since diagnosis, disease stage, and period of diagnosis.ResultsMarked differences in the one- and five-year age-standardized net survival rates were observed across the cancer sites. Pancreatic cancer had the lowest 5-year net survival (5.5 %, 95 %CI: 2.9–9.4) followed by oesophageal cancer (5.6 %, 95 %CI: 3.0–9.4), while prostate cancer ranked the best (92.1 %, 95 %CI: 87.8–94.9), followed by thyroid cancer (87.4 %, 95 %CI: 69.9–95.1) and female breast cancer (78.3 %, 95 %CI: 74.5–81.6). The survival rates differed substantially according to sex and clinical stage. Comparing the first (2000–2005) and last (2012–2018) periods, cancer survival improved, especially for thyroid, leukemia, and pharyngeal cancers, with differences of 34.4 %, 29.0 %, and 28.7 %, respectively.ConclusionTo our knowledge, this is the first study to evaluate long-term cancer survival in the Barretos region, showing an overall improvement over the last two decades. Survival varied by site, indicating the need for multiple cancer control actions in the future with a lower burden of cancer.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号