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1.
Predatory mites (Acari: Mesostigmata) on tree trunks without significant epiphytic growth in a subtropical rainforest in Eastern Australia were assessed for habitat specificity (i.e. whether they are tree trunk specialists or occupying other habitats) and the influence of host tree and bark structure on their abundance, species richness and species composition. The trunks of nine tree species from eight plant families representing smooth, intermediate and rough bark textures were sampled using a knockdown insecticide spray. In total, 12 species or morphospecies of Mesostigmata (excluding Uropodina sensu stricto) were collected, most of which are undescribed. Comparison with collections from other habitats indicates that epicorticolous Mesostigmata are mainly represented by suspended soil dwellers (six species), secondarily by generalists (four species) and a bark specialist (one species). A typical ground-dwelling species was also found but was represented only by a single individual. In terms of abundance, 50.5% of individuals were suspended soil dwellers, 40.7% bark specialists, and 8.3% generalists. Host species and bark roughness had no significant effect on abundance or species richness. Furthermore, there was no clear effect on species composition. The distribution of the most frequently encountered species suggests that most mesostigmatid mites living on bark use many or most rainforest tree species, independent of bark roughness. These findings support the hypothesis that some epicorticolous Mesostigmata use tree trunks as ‘highways’ for dispersing between habitat patches, while others use it as a permanent habitat.  相似文献   

2.
The objective of this study was to evaluate the diversity of Phytoseiidae in the Atlantic Forest of São Paulo State, Brazil, and to estimate the possible role of this ecosystem as a reservoir for mites of this family. Samples were taken from 187 plant species belonging to 73 plant families in three vegetation types of the Atlantic Forest, from February 2001 to October 2002. In total, 1102 specimens of 54 species belonging to 20 genera of the three phytoseiid subfamilies were found. Most specimens (93%) and species (91%) belonged to the Amblyseiinae. The majority of species found belong to taxonomic groups largely composed of generalist predators (especially Amblyseius and Euseius). In general, the more abundant mites were found on a diversity of plant species, but a few of the abundant species were found on only a small number of plant species. Only nine of the mites encountered during this study are of known agricultural importance. The results obtained suggest the importance of the wide plant diversity in the region to sustain a wide diversity of phytoseiids. The extensive clearance of the Brazilian Atlantic Forest is a threat to the diversity of these mites, important predators of mite pests.  相似文献   

3.
The use of molecular markers for resolving systematics issues has improved our knowledge of life history. However, for the taxa studied herein—the predatory mite family Phytoseiidae—molecular phylogeny is impeded by a lack of suitable markers for deeper taxonomic levels. This study aims (i) to establish DNA amplification protocols for molecular markers known to resolve supraspecific nodes in other taxa, (ii) to determine their individual performance in assessing the clustering of species, genera, tribes and subfamilies, and (iii) to characterize the additional information provided when markers are concatenated. A new phylogenetic index is proposed based on ecological concepts, considering trees as a community of nodes. New and efficient protocols for DNA amplification of six molecular markers are provided. The concatenated tree globally provides more robust and reliable information, especially for deeper nodes. However, for assessing species identification and within‐genera phylogenies, the combined use of six markers does not seem necessary, underlining the need to resize experiments depending on their taxonomic objectives. Finally, this study lays the methodological foundations with which to test the present Phytoseiidae classification as the first phylogeny obtained shows incongruence with the present morphological classification.  相似文献   

4.
The translocator protein (TSPO) is a potential drug target for the treatment of CNS diseases, with TSPO ligands being able to modulate steroidogenesis, apoptosis, and cell proliferation. While there exist multiple TSPO binding sites, the nature of these sites--either overlapping or allosterically linked--remains largely uncharacterized. Furthermore, while evidence suggests that microglial activation and polymerization result in changes to TSPO binding sites, these changes are poorly understood. While current pharmacophoric models can be used to synthesize TSPO ligands with high affinity and selectivity, these models are unable to predict ligands with desirable functional effects. Better characterization of TSPO binding sites in health and disease may provide insight into particular sites which mediate promising therapeutic profiles, thus refining the TSPO pharmacophore.  相似文献   

5.
The aim of this study was to assess the phoretic relationship between two beetle species of the genus Tetropium and mites from order Mesostigmata. The study was conducted in the Bia?owie?a Forest, which is recognized as one of Europe’s last natural forest areas. Insects were caught over a period of 8 weeks in 72 attractant traps (type Intercept IPM). In total 1250 specimens of genus Tetropium were collected. We analyzed 524 beetles, including 295 specimens of T. castaneum and 229 specimens of T. fuscum. On 49 beetles (9.4%) there were 785 individuals of Trichouropoda shcherbakae (Trematuridae). Mites were more common on T. fuscum, which carried 82% of all collected deutonymphs. Most of the mites found on beetles were attached to their legs. This study reports on changes in the intensity of phoresy in time and location of mite deutonymphs on their host species.  相似文献   

6.
In 1989 Guyana designated 3600 km2 of tropical rain forest as the Iwokrama Rain Forest Programme (IRFP) for developing methods of sustainable forest utilization and for conserving biodiversity. Bat diversity was assessed in 5 km2 of the IRFP area over a ten-week period. Effort totalled 22 400 m2 mist-net hours during 26 nights, 227 m2 harp-trap hours during 8 nights and 28 person days searching for roosts. This revealed 38 species of bats. In comparison with two other neotropical sites alpha diversity was high as shown by a Shannon diversity index of 1.30 for the 33 species taken in foraging areas by mist net and harp trap.Four forest types found here show some of the lowest floristic diversity in the neotropics. The high motility of bats allows them to exploit the range of forest types available locally, so avoiding constraints imposed within any one forest type.A list of bat species known from Guyana was compiled from the literature. A total of 96 species were found plus 17 unsupported records. The list is presented together with a further 45 species that potentially could occur. Our survey has shown that 45 of the 96 species recorded in Guyana (47%) are known from the IRFP area, suggesting that it provides a good representation of Guyana's bat fauna.The work formed part of a Guyana Rain Forest biodiversity programme coordinated by Mike Gillman at The Open University, Walton Hall, Milton Keynes, MK7 6AA, England, UK.  相似文献   

7.
The generic richness and abundance of Bethylidae collected in four different hillside areas of Atlantic rain forest from Espírito Santo, Brazil were studied. The sites are Santa Maria de Jetibá (SMJ), Domingos Martins (DM), Pancas (P) and Atílio Vivacqua (AV). A total of 2,840 specimens of 12 genera were collected. Lepidosternopsis Ogloblin and Bakeriella Kieffer are first recorded from the State. Richness of taxa was calculated using first-order Jackknife richness with EstimateS program. Genera accumulation curves were ran to evaluate the samples. Abundance data were adjusted to the geometric distribution. Parameter k was used to compare areas. The generic profile was not equal for the sites we studied. The areas were considered disturbed. SMJ and DM presented genera richness bigger than in P and AV. The differences in the sites reflect the different preservation of each environment. Pseudisobrachium Kieffer and Dissomphalus Ashmead are most dominant genera in SMJ, DM and P, and Anisepyris Kieffer in AV. This study emphasizes the fact of Dissomphalus as the most abundant genus in rain forests. The generic profile found in AV is similar to that of some areas of Brazilian savannah.  相似文献   

8.
Eutrophication and the associated proliferation offilamentous algae were often considered importantcauses of reed die-back that occurred in the sixtiesand seventies at Lake Constance. According to thishypothesis the reduction in lake water nutrientconcentrations during the eighties and nineties shouldhave reduced the abundance of filamentous algae andwhich should have reduced the supposed mechanicalimpact of filamentous algae on the lakeside reedstands. To examine whether this had actually occurred,the condition of the lakeside reed border at LakeConstance (Untersee) was surveyed in 1994 and resultswere compared to those of similar surveys carried outin the years 1981–83. The extent of mechanical damageto reed stalks, the amount of macrophyte wash and thedegree of shoreline erosion were assessed forshoreline segments of 25 m along a total shorelinelength of 65 km. The results showed that mechanicaldamage to reed stalks was generally higher in 1994than in 1981–83, while macrophyte wash and shorelineerosion were generally less severe. The decreasedamount of macrophyte wash was associated with a changein macrophyte species composition from a dominance offloating filamentous algae to a dominance of rootedPotamogetonaceaeand fragile Characeae,and therefore probably was due to the lower nutrientconcentrations of the lake. The opposite trends foundfor mechanical damage to reed stands and the amount ofmacrophyte wash between 1981–83 and 1994, as well asthe absence of relation between the two variables in1994, suggested that macrophyte wash had only a minoreffect on the condition of lakeside reed stands atLake Constance. Highly damaged reed stands and erodedcliffs were often located at wind exposed sites orclose to highly frequented shipping routes in 1994,suggesting that mechanical stress from waves wasresponsible for the damage. Due to the lakewardprogression of reed stands during the early nineties,reed stalks were, on average, located in deeper waterin 1994 than in 1981–83. This might have strengthenedthe mechanical stress from wave action even more andhave caused the higher frequency of mechanical damageto reed stalks. Other causes of damage such asmacrophyte wash, roosts of birds or bird swarmsprobably played a minor and only local role.  相似文献   

9.
Wild animals increasingly inhabit human-influenced environments such as forest fragments amid agricultural systems. Dietary studies provide a means of assessing wildlife responses to anthropogenic habitat changes. Chimpanzees are specialist frugivores that consume other plant parts, e.g., fibrous pith and leaves, in greater amounts during fruit shortages. I examined the plant diet and seasonal foraging strategies of chimpanzees inhabiting small forest fragments within a cultivated landscape in Uganda. I determined diet over 13 mo via systematic fecal analysis, supplemented by direct observation and feeding trace evidence. I identified important foods and examined their role as seasonal fallbacks. Diet composition and breadth were overall species typical. Chimpanzees were highly frugivorous and the fruit component of fecal samples exceeded that of nonfruit fiber in all months. Forest fruit availability fluctuated seasonally, including a 3-mo low fruiting season, when overall fruit intake declined. During this time chimpanzees pursued a mixed strategy of increasing fiber consumption and feeding more heavily on energy-rich cultivars, including those obtained through crop raiding. The data suggest that exploiting agricultural fruits helped chimpanzees maintain a fruit-dominated diet when forest fruit was scarce. No evidence suggested this disturbed forest–farm mosaic is a food-impoverished habitat for chimpanzees overall. Nevertheless, cultivar feeding creates conflict with people and the high nutritional quality of crops is likely offset by the inherent risk associated with obtaining them. This study adds to growing evidence of ecological and behavioral adaptability of Pan troglodytes in response to anthropogenic habitat alteration. Targeted conservation of key natural foods for wildlife —particularly fallbacks— would help reduce conflicts and improve the survival prospects of threatened species sharing environments with people.  相似文献   

10.
Boreal species were repeatedly exposed to ice ages and went through cycles of contraction and expansion while sister species alternated periods of contact and isolation. The resulting genetic structure is consequently complex, and demographic inferences are intrinsically challenging. The range of Norway spruce (Picea abies) and Siberian spruce (Picea obovata) covers most of northern Eurasia; yet their geographical limits and histories remain poorly understood. To delineate the hybrid zone between the two species and reconstruct their joint demographic history, we analysed variation at nuclear SSR and mitochondrial DNA in 102 and 88 populations, respectively. The dynamics of the hybrid zone was analysed with approximate Bayesian computation (ABC) followed by posterior predictive structure plot reconstruction and the presence of barriers across the range tested with estimated effective migration surfaces. To estimate the divergence time between the two species, nuclear sequences from two well‐separated populations of each species were analysed with ABC. Two main barriers divide the range of the two species: one corresponds to the hybrid zone between them, and the other separates the southern and northern domains of Norway spruce. The hybrid zone is centred on the Urals, but the genetic impact of Siberian spruce extends further west. The joint distribution of mitochondrial and nuclear variation indicates an introgression of mitochondrial DNA from Norway spruce into Siberian spruce. Overall, our data reveal a demographic history where the two species interacted frequently and where migrants originating from the Urals and the West Siberian Plain recolonized northern Russia and Scandinavia using scattered refugial populations of Norway spruce as stepping stones towards the west.  相似文献   

11.
The life cycle of the water mite Unionicola foili includes larvae that parasitize chironomid dipterans, and nymphs and adults that occur in association with the freshwater mussel Utterbackia imbecillis. The georesponses and photoresponses of larval U. foili in the presence of chemical substances from chironomids and mussels both prior to (= pre-chironomid larvae) and after their parasitism with chironomids (= post-chironomid larvae) were examined in the laboratory. The responses of larval U. foili to light and gravity changed during larval ontogeny and varied depending on the chemistry of the medium in which they were examined. Pre-chironomid larvae preferentially responded to water modified by chironomids given that negative phototaxis and positive georesponses were elicited only in the presence of water that had been modified by these hosts. Post-chironomid larvae exhibited host-induced negative phototaxis only in the presence of mussel-modified water. Post-chironomid larvae were consistently geopositive when exposed to water modified by mussels or chironomids. The pattern of responses exhibited by larval U. foili to light and gravity are interpreted as adaptations for locating potential hosts in the field.  相似文献   

12.
Bonartseva  G. A.  Myshkina  V. L.  Nikolaeva  D. A.  Rebrov  A. V.  Gerasin  V. A.  Makhina  T. K. 《Microbiology》2002,71(2):221-226
The biodegradation of films made of poly--hydroxybutyrate (PHB) with a molecular mass of 1500 kDa was studied using a model soil community in the presence and absence of nitrate and at different concentrations of oxygen in the gas phase. The biodegradation of PHB was investigated with respect to changes in its molecular mass, crystallinity, and some mechanical properties.  相似文献   

13.
An applied groundwater study of the Plana de Castellón was performed to investigate possible impacts of pollutants on ecological characteristics of the aquifer. The area is illustrative for a western mediterranean coastal plain, densely populated, industrialized, and with intensive agricultural land-use. During one year, six wells in a subsection of the plain were monitored, simultaneously sampled for zoological and physicochemical analysis. Heavy metals and pesticides were not (or at very low levels) detected in the wells. Low correlations were found between physicochemical and biological data, but there were indications that organic pollution affects the abundance of the fauna. A logarithmic relationship between abundance and COD/BOD5-ratio is postulated. Salinization, an important threat to the groundwater of the area, was clearly reflected in the chemistry of one of the wells. Probably, this process has important consequences for abundance and diversity of the fauna.  相似文献   

14.
It has been reported in several studies that there may be a significant correlation between reproductive history and the risk of osteoporosis due to the effect of estrogen. Under this hypothesis, however, it is unclear whether the age at first delivery has any major influences on the risk of osteoporosis. Therefore, this study aimed to investigate the relationship between the age at first delivery and the risk of osteoporosis in Korean menopausal women. This study was performed using data from the 2008–2011 Korea National Health and Nutrition Examination Survey and included 2,530 Korean postmenopausal women. The diagnosis of osteoporosis was made using the World Health Organization T-score criteria (T-score ≤ -2.5, at the femoral neck or lumbar spine). Participants were categorized into 3 groups according to age at first delivery: ≤23, 24–29, and ≥30 years. Older age, lower body mass index, lower calcium intake, later menarche, and earlier menopause increased the risk of osteoporosis, whereas hormone therapy and oral contraceptive use were associated with a decreased risk of osteoporosis. Postmenopausal women whose first delivery occurred at age 24–29 years were shown to have a significantly increased risk of osteoporosis (odds ratio, 2.124; 95% confidence interval, 1.096–4.113; P = 0.026) compared to those who first gave birth after the age of 30 years. These findings suggest that postmenopausal women whose first delivery occurred in their mid to late 20s, a period during which bone mass slowly accumulates to the peak, are at an increased risk of osteoporosis.  相似文献   

15.
16.
The life history and feeding habits of Pontoporeia affinis Lindström were studied in mesotrophic Lake Erken during 1982 to 1983. The greatest densities and biomasses of P. affinis occurred at 12 m (662 ind./m2 and 118.2 mg dw/m2, respectively) with values decreasing at the shallower and deeper regions. The life cycle of Pontoporeia was one year, with recruitment occurring in April, at which time the majority of the population consisted of individuals <2 mm. Overall the gut content of Pontoporeia was predominantly composed of detritus (97.6%) with algae accounting for 2.3%. Annual production was highest at 12 m (386.2 mg dw/m2) and lowest at 16 m (8.1). The highest production occurred during September, coinciding with the autumn Bacillariophyceae bloom.  相似文献   

17.
Summary Restriction fragment length polymorphisms (RRLPs) located at short distances may demonstrate linkage disequilibrium. Under the assumption that the distances between the loci of the RFLPs are inversely related to the linkage disequilibria, gene order may be deduced. However, if the assumption is invalid, the results may be incorrect. We have studied four different DNA polymorphisms at the COLIA2 locus in 180 unrelated Norwegian individuals. Observed frequencies (presence/absence) for the different polymorphic sites were as follows: site A (EcoRI) 0.30/0.70, site B (MspI) 0.83/0.16, site C (StuI) 0.86/0.14, and site D (RsaI) 0.66/0.34. Of 16 possible haplotypes 12 were demonstrated, and 2 additional were deduced to be present. Restriction mapping of the four polymorphic sites gave the following order of the sites from the 5 to the 3 of the gene: A-D-B-C. Linkage disequilibrium was not found between the sites A and D; strong disequilibrium was found between sites A and C, and B and C; and less strong, between A and B, B and D, and C and D. Analysis of linkage disequilibrium coefficients between all pairs of loci demonstrated that there is no consistent relationship between linkage disequilibrium and physical distance (=-0.07). These results suggest that for a small region of the genome, factors such as deviating mutation rate and gene conversion may add significantly to rearrangements by recombination. Thus, a deduced gene order from linkage disequilibrium data has to be regarded with great caution.  相似文献   

18.
19.
Since the 1970s, the public has been advised to limit egg consumption even though there is little evidence of any harmful effect of eggs on blood cholesterol. The purpose of this cross-sectional and prospective study was to evaluate the potential association between egg consumption and metabolic syndrome (MetS) and MetS components in adults ≥ 40 years in KoGES_Yangpyeong. Yangpyeong is a rural area in South Korea. A total of 2,887 subjects (men 1,115, women 1,772) were recruited from 2005 to 2009, based on a physical examination and questionnaires administered using standardized protocol. After excluding subjects who had MetS at baseline, 1,663 subjects (675 men, 958 women) were followed for 3.20 years (range: 0.34–8.70). During the follow-up period, MetS occurred in 289 subjects. More than 3 eggs per week was significantly associated with decreased risk of MetS in both men (RR = 0.46, 95% CI, 0.26–0.82, P for trend = 0.1093) and women (RR = 0.54, 95% CI, 0.31–0.93, P for trend 0.0325) compared to non-users. There was a cross-sectional inverse relationship between egg consumption and abdominal obesity in men and women. Also, prospectively, higher egg consumption in men was associated with a decreased risk of high fasting blood glucose (RR = 0.39, 95% CI, 0.22–0.67, P for trend = 0.0042) and high triglycerides (RR = 0.42, 95% CI, 0.22–0.80, P for trend = 0.1080). In conclusion, our findings suggest that higher egg consumption may reduce the risk of MetS both in men and women, and the risk of high fasting blood glucose and high triglycerides in men. Current guidelines regarding egg consumption may need to be re-visited for healthy middle-aged and elderly people.  相似文献   

20.
Recent studies have reported correlations between mineral intake and metabolic syndrome (MS), but accurate relationships and consistency in the results are difficult to confirm. Accordingly, this study aims to assess the dietary intakes of magnesium (Mg), manganese (Mn), and copper (Cu) to determine their relationship with MS. Data from a total of 5,136 adults (2,084 men, 3,052 women) was collected from the 2007–2008 Korea National Health and Nutrition Examination Survey (KNHANES), and the intakes of Mg, Mn, and Cu of the MS patients were compared with those of healthy adults. The relationship between the intakes of these minerals and the MS risks was analyzed. Diagnosis of MS was evaluated by the National Cholesterol Education Program's Adult Treatment Panel III (NCEP-ATP III) standards. Among all study subjects, 25.9 % (540 subjects) of the men and 24.5 % (748 subjects) of the women met diagnostic criteria for inclusion in the MS group. In the men, daily intakes of Mg and Cu in the MS group were significantly lower than those in control group, and in the women, daily intakes of energy, Mg, Mn, and Cu in the MS group were significantly lower than those of the control group. The women subjects with high blood pressure showed significantly lower intakes of Mg, Mn, and Cu than control subjects. In addition, in the women, the highest quartile of Mg and Cu was inversely associated with MS, but with adjustment were not maintained. However, in the postmenopausal women, MS was significant and inversely associated with the highest quartiles of Cu intake and the association remained significant after adjustments. Considering that MS incidence increases and dietary intake and nutrient density decrease with increasing age, and mineral intake is reduced accordingly, these results suggest that meal management with adequate mineral intake is advisable to control MS.  相似文献   

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