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PubMed2026

Holmium laser enucleation of the prostate for the treatment of lower urinary tract symptoms in men with benign prostatic hyperplasia.

RATIONALE: A range of surgical options is available for the treatment of benign prostatic hyperplasia (BPH), including holmium laser enucleation of the prostate (HoLEP). The evidence is unclear regarding differences in functional, perioperative, and morbidity outcomes between these modalities. OBJECTIVES: To assess the effects of holmium laser enucleation of the prostate compared with other surgical treatments for lower urinary tract symptoms in men with benign prostatic hyperplasia. SEARCH METHODS: We searched multiple databases (including MEDLINE, Embase, CENTRAL, Web of Science, LILACS, and the International HTA database), trial registries, and conference abstracts through April 08, 2026. ELIGIBILITY CRITERIA: We only included randomized trials of men over 40 years of age with a prostate volume of at least 20 mL (assessed by digital rectal examination, ultrasound, or conventional imaging) who exhibited lower urinary tract symptoms (LUTS) defined by an International Prostate Symptom Score (IPSS) of eight or greater undergoing surgical interventions for BPH. OUTCOMES: The critical outcomes measured were the urologic symptoms score, the quality-of-life score, and major adverse events. The important outcomes measured were: re-treatment, erectile function, ejaculatory function, transfusions, acute urinary retention, indwelling urinary catheter duration, and hospital stay duration. RISK OF BIAS: We used the Cochrane risk of bias tool (RoB 1) to assess for potential sources of bias on a study and outcome level basis. SYNTHESIS METHODS: We pooled outcome data using the random-effects model and performed meta-analyses using the Mantel-Haenszel method. We assessed statistical heterogeneity in the pooled data by visually inspecting forest plots and using the I2 statistic to quantify it. We used the GRADE framework to assess the certainty of evidence. INCLUDED STUDIES: We included 52 trials that included 6242 participants that compared HoLEP to other surgical interventions for benign prostatic hyperplasia. The median age of participants across the studies ranged from 65 to 74 years. The baseline prostate volume ranged from 30 cc to 142 cc. Baseline IPSS scores ranged from 19.6 to 28.6 (range 0-35). SYNTHESIS OF RESULTS: We prioritized comparing HoLEP with transurethral resection of the prostate (TURP) at short-term follow-up (up to 12 months), because TURP is the long-standing reference standard and the predominant comparator in randomized surgical trials. Findings for the four remaining comparisons (laser ablation, alternative energy source enucleation, other minimally invasive therapies, and simple prostatectomy), for long-term follow-up, and for all remaining outcomes are reported in full in the review. Compared to TURP, at short-term follow-up: Critical outcomes - HoLEP may result in little to no difference in short-term urologic symptom scores measured using the IPSS (range 0 to 35; lower values reflect fewer symptoms) (MD -0.67, 95% CI -1.20 to -0.14; I² = 93%; 14 studies, 1666 participants, low-certainty evidence). - HoLEP may result in little to no difference in short-term quality of life (range 0 to 6; lower values reflect better quality of life) (MD -0.04, 95% CI -0.23 to 0.15; I² = 73%; 6 studies, 876 participants, low-certainty evidence). - HoLEP may result in little to no difference in short-term major adverse events (RR 0.75, 95% CI 0.35 to 1.58; I² = 0%; 10 studies, 1147 participants, low-certainty evidence). Important outcomes - HoLEP likely results in little to no difference in re-treatment (RR 0.45, 95% CI 0.14 to 1.50; I² = 0%; 8 studies, 813 participants, moderate-certainty evidence). - HoLEP likely results in little to no difference in erectile function (MD -0.03, 95% CI -0.47 to 0.42; I² = 0%; 3 studies, 518 participants, moderate-certainty evidence). - Ejaculatory function: we did not find any data for this outcome. - HoLEP likely reduces the need for blood transfusion (RR 0.19, 95% CI 0.09 to 0.42; I² = 0%; 15 studies, 1755 participants, moderate-certainty evidence). AUTHORS' CONCLUSIONS: Compared with TURP, HoLEP may achieve similar relief of urologic symptoms, similar quality of life, and similar rates of major adverse events in the first 12 months after surgery, and probably similar re-treatment rates and erectile function. HoLEP likely reduces the need for blood transfusion; this is the only advantage of HoLEP that the randomized evidence, as summarized here, supports as clinically important. There was insufficient evidence to assess outcomes in the subset of individuals with larger prostates or on anticoagulation. Future research should prioritize long-term trials reporting sexual function and urinary incontinence outcomes, recruit men with very large prostates (≥ 150 cc) or on anticoagulation therapy, and evaluate cost-effectiveness and training requirements. FUNDING: No external funding was received for this review. REGISTRATION: The protocol for this review was published in the Cochrane Database 2019 (https://doi.org/10.1002/14651858.CD013291).

Humans↗
PubMed2002

Environmental conditions and host genotype direct genetic diversity of Venturia ditricha, a fungal endophyte of birch trees.

We investigated whether genetic variation of a common foliar endophyte of birch trees, Venturia ditricha, is affected by environmental conditions or host genotype. Fungal samples were collected from 10 half-sibling families of mountain birch (Betula pubescens ssp. czerepanovii) grown in two environmental conditions with different daily average temperatures: a forested river valley and an adjacent open tundra (altitudinal difference 180 m). Genetic analysis of V. ditricha isolates was done using random amplified microsatellite polymerase chain reaction. We found that host genotypes, along with prevailing environmental conditions, influence the probability of infection by particular endophyte genotypes. The most susceptible host genotypes were highly infected with genetically similar endophyte genotypes, whereas the most resistant trees were poorly infected and they were infected by genetically dissimilar endophytes. Our results also showed environment-host genotype interactions, suggesting that the susceptibility of the host to a particular endophyte genotype may change in natural environments when environmental conditions are changed. It appears that a particular endophyte genotype needs to find the right host genotype for a successful infection. There are many host genotypes in natural stands; this means, from the point of view of the fungus, the environment is heterogeneous. Thus, under the influence of birch tree genotypes, genetically differentiated subgroups of the endophytic fungus may be formed in different environments.

Ascomycota↗
PubMed2002

Amenity values of public and private forests: examining the value-attitude relationship.

Public values toward forests have changed since the late 1980s, from a commodity-oriented perspective toward a more inclusive (commodity and non-commodity) orientation. This study examines the influence of four indicators of population diversity (age, ethnic background, place of residence, and gender) on amenity values of forests, environmental attitudes, and forest value-attitude correspondence. Four values of public and private forests were assessed, wood production (utilitarian value), clean air (a life support value), scenic beauty (an aesthetic value), and heritage (a spiritual value). Environmental attitudes were measured using a modified version of the New Environmental Paradigm scale. Five hundred and forty-eight randomly selected residents of households in 13 states of the Southern United States participated in a telephone interview. Age and ethnic background were found to moderate the value-attitude relationship, with the strength of the association being dependent upon the type of forest (i.e., public or private) and the forest value (i.e., utilitarian, life support, spiritual, and aesthetic). Females, younger persons (less than 43 years old), and whites reported lower utilitarian values of forests than their respective counterparts. Results are interpreted within the context of an emerging post-material society, in which a biocentric orientation to forests and the natural environment may be favored more by a younger (versus older) generation and increasingly racially diverse U.S. population. Implications for managing forests using a multiple-values (versus multiple-uses) approach are discussed.

Adolescent↗
PubMed2003

Genetic differentiation among populations of Sesleria albicans Kit. ex Schultes (Poaceae) from ecologically different habitats in central Europe.

As observed for many other plant species, the populations of Sesleria albicans in Central Europe are located in habitats, which differ to a high degree from each other with regard to ecological factors such as nutrients, light and water as well as in type of land use. The species colonizes limestone cliffs, pavements, screes, grazed and mown grasslands, heaths, fens and open woodlands. In this study, we used random amplified polymorphic DNA (RAPD) analysis to investigate the genetic differentiation among 25 populations of S. albicans from six different types of habitat (beech forests, alpine and lowland rocky ridges, lowland screes, fens, calcareous grasslands). With RAPD analysis, 344 fragments could be amplified, of which 95.9% were polymorphic. The level of polymorphism ranged from 29.7 to 56.7% polymorphic bands per population and was correlated with population size. In an analysis of molecular variance (AMOVA), used to detect variation among individuals within populations, among populations from the same habitat and among different habitats, most of the genetic variation was found within populations (62.06%) and among populations from the same habitat (33.36%). In contrast, only a very low level of differentiation could be observed among different habitats (4.58%). The results of our study give only little evidence for an ecotypic differentiation of Sesleria albicans. This differentiation is principally conceivable, but obviously not related to the investigated RAPD loci.

Analysis of Variance↗
PubMed2006

The phylogenetic structure of a neotropical forest tree community.

Numerous ecological and evolutionary processes are thought to play a role in maintaining the high plant species diversity of tropical forests. An understanding of the phylogenetic structure of an ecological community can provide insights into the relative importance of different processes structuring that community. The objectives of this study were to measure the phylogenetic structure of Neotropical forest tree communities in the Forest Dynamics Plot (FDP) on Barro Colorado Island, Panama, to determine how the phylogenetic structure of tree communities varied among spatial scales and habitats within the FDP, and to study the effects of null-model choice on estimates of community phylogenetic structure. We measured community phylogenetic structure for tree species occurring together in quadrats ranging in size from 10 x 10 m to 100 X 100 m in the FDP. We estimated phylogenetic structure by comparing observed phylogenetic distances among species to the distribution of phylogenetic distances for null communities generated using two different null models. A null model that did not maintain observed species occurrence frequencies tended to find nonrandom community phylogenetic structure, even for random data. Using a null model that maintained observed species frequencies in null communities, the average phylogenetic structure of tree communities in the FDP was close to random at all spatial scales examined, but more quadrats than expected contained species that were phylogenetically clustered or overdispersed, and phylogenetic structure varied among habitats. In young forests and plateau habitats, communities were phylogenetically clustered, meaning that trees were more closely related to their neighbors than expected, while communities in swamp and slope habitats were phylogenetically overdispersed, meaning that trees were more distantly related to their neighbors than expected. Phylogenetic clustering suggests the importance of environmental filtering of phylogenetically conserved traits in young forests and plateau habitats, but the phylogenetic overdispersion observed in other habitats has several possible explanations, including variation in the strength of ecological processes among habitats or the phylogenetic history of niches, traits, and habitat associations. Future studies will need to include information on species traits in order to explain the variation in phylogenetic structure among habitats in tropical forests.

Ecosystem↗
PubMed2002

Interaction between root lesion nematode Pratylenchus vulnus and two species of Fusarium on growth and development of maple seedlings.

Producing healthy seedlings and distributing them to far areas, is one of the most important factor for developing forests. Because of easy planting, rapid growth and good wood quality, Acer velutinum is the most useful species, among the softwood and hardwood trees. Growth and development of the nurseries were effected by different pests and diseases, the nematodes are one of these agents. They are not actively surveyed in the forest nurseries in Iran. On a survey of maple seedling in the forest nurseries Pratylenchus vulnus, Fusarium solani and F. oxysporum were identified. The interaction between these two fungi and nematode were studied in randomized complete block design with four replications and six treatments. For mass production and multiplication of the nematodes, they were sterilized with Streptomycin Sulfate, they were reared on carrot disc culture. The nematodes were then added to each pot. The results showed a highly significant difference (p = 0.01) between different treatments. In the treatment with nematodes alone growth of seedlings was minimum and population density of nematodes in soil and root tissue was maximum. In this treatments 75% of seedlings were died and seedling average height were 2.25 cm. In the treatments with nematode and fungi together the population of nematodes were decreased and the growth of seedlings were increased, in comparison with nematode alone. F. oxysporum showed more antagonistic effect on nematodes than F. solani. In the nematode + F. oxysporum treatment, 25% of seedlings were died and seedling average height was 12.75 cm. In the nematode + F. solani treatment, 50% of seedlings were died and the seedling average height was 5.5 cm. This is the first report of pathogenecity of Pratylenchus vulnus and its interaction whit fungi on maple seedlings in Iran.

Acer↗
PubMed2005

Separating rhizosphere respiration from total soil respiration in two larch plantations in northeastern China.

The potential capacity of soil to sequester carbon in response to global warming is strongly regulated by the ratio of rhizosphere respiration to respiration by soil microbial decomposers, because of their different temperature sensitivities. To quantify relative contributions of rhizosphere respiration to total soil respiration as influenced by forest stand development, we conducted a trenching study in two larch (Larix gmelini (Rupr.) Rupr.) plantations, aged 17 and 31 years, in northeastern China. Four plots in each plantation were randomly selected and trenched in early May 2001. Soil surface CO2 effluxes both inside and outside the plots were measured from May 2001 to August 2002. Soil respiration (i.e., the CO2 effluxes outside the trenched plots) varied similarly in the two plantations from 0.8 micromol m(-2) s(-1) in winter to 6.0 micromol m(-2) s(-1) in summer. Rhizosphere respiration (i.e., CO2 efflux outside the trenched plots minus that inside the plots) varied from 0.2 to 2.0 micromol m(-2) s(-1) in the old forest and from 0.3 to 4.0 micromol m(-2) s(-1) in the young forest over the seasons. Rhizosphere respiration, on average, accounted for 25% of soil respiration in the old forest and 65% in the young forest. Rhizosphere and soil respiration were significantly correlated with soil temperature but not with soil water content. We conclude that the role forests play in regulating climate change may depend on their age.

Agriculture↗
PubMed2026

Effects of transcutaneous electrical acupoint stimulation versus acupressure on the trajectories of multidimensional adverse reactions to chemotherapy in breast cancer patients: a secondary analysis of a randomized controlled trial.

BACKGROUND: Chemotherapy for breast cancer often induces multidimensional adverse reactions such as nausea and vomiting, anxiety, depression, and sleep disturbances. These symptoms are interrelated and may evolve dynamically, impacting patients' treatment outcomes and quality of life. As non-pharmacological interventions, transcutaneous electrical acupoint stimulation (TEAS) and self-acupressure (SA) have shown potential in alleviating symptoms. However, their long-term effects on the joint developmental trajectories of these multidimensional symptoms (nausea and vomiting, anxiety, depression, and sleep disturbances) remain unclear. OBJECTIVE: This study aimed to identify potential trajectory class of multidimensional adverse reactions in breast cancer patients undergoing chemotherapy and to explore the differential effects of TEAS and SA on different trajectory subgroups. METHODS: This was a secondary analysis of a randomized controlled trial. A total of 189 breast cancer patients receiving chemotherapy were included. The Group-Based Multi-Trajectory Model (GBMTM) was employed to identify joint developmental trajectories of acute/delayed chemotherapy-induced nausea and vomiting (CINV), anxiety, depression, and sleep quality during chemotherapy. Subsequently, causal forest was used to analyze the average treatment effects (ATE) of TEAS (vs. control group) and SA (vs. control group) on patients' symptom trajectory. RESULTS: Multidimensional adverse reactions were classified into two heterogeneous trajectories: a "High Symptom Burden-Persistent (HSBP)" type (n&#x2009;=&#x2009;101) and a "Low Symptom Burden-Relieving (LSBR)" type (n&#x2009;=&#x2009;88). The persistent high incidence of acute CINV contrasted sharply with the comprehensive relief of other symptoms in the latter group. Causal forest suggested that both TEAS and SA significantly increased the probability of patients being classified into the "LSBR" trajectory. The ATE was 0.147 (95% CI: 0.143, 0.151) for TEAS, slightly lower (P&#x2009;<&#x2009;0.05) than 0.176 (95% CI: 0.162, 0.190) for SA.&#xa0; CONCLUSION: Multidimensional adverse reactions in breast cancer patients undergoing chemotherapy exhibit heterogeneity in their trajectories. Both TEAS and SA were associated with a higher probability of patients being classified into a more favorable symptom trajectory-LSBR. The multidimensional trajectory identification with treatment effect estimation may serve as a useful analytical strategy for future longitudinal research in cancer chemotherapy-induced adverse reactions symptom management. CLINICAL TRIAL REGISTRATION: ChiCTR2300077667 (Chinese Clinical Trial Registry, https://www.chictr.org.cn/ ), Registered 15 November 2023.

Humans↗
PubMed2001

Patterns of DNA sequence variation in chromosomally recognized taxa of Anopheles gambiae: evidence from rDNA and single-copy loci.

Patterns of DNA sequence variation in the ribosomal DNA (rDNA) second internal transcribed spacer (ITS2) and five unlinked single-copy nuclear loci were examined for evidence of reproductive isolation among four chromosomally recognized taxa of Anopheles gambiae from West Africa: Savanna, Bamako, Mopti and Forest, as well as sibling species An. arabiensis and An. merus. Included among the single-copy loci were three sequence-tagged random amplified polymorphic DNA (RAPD) loci, two of which (R15 and R37) had been reported as discriminating between Mopti and other chromosomal forms. Each of the five single-copy sequences were highly polymorphic in most samples. However, the R15 and R37 loci had no diagnostic value, and therefore are not recommended as tools in recognition of field-collected An. gambiae chromosomal forms. Although pairwise comparisons between species generally revealed significant levels of differentiation at all five loci, variation was not partitioned by chromosomal form within An. gambiae at any single-copy locus examined. The few exceptions to these trends appear related to a location either inside or nearby chromosomal inversions. At the tryptophan oxygenase locus inside inversion 2Rb, variation was structured only by inversion orientation and not by taxonomic designation even between An. gambiae and An. arabiensis, providing the first molecular evidence that the 2Rb inversion was transferred between species by introgressive hybridization. By contrast, the rDNA showed fixed differences between species and a difference diagnostic for Mopti, consistent with effective, if not complete, reproductive isolation. The apparent disagreement between the data from this locus and multiple single-copy loci within An. gambiae may be explained by the much lower effective population size of rDNA, owing to concerted evolution, which confers increased sensitivity at much shorter divergence times. Taken together with the accompanying reports by della Torre et al. (2001), Favia et al. (2001) and Gentile et al. (2001), our data suggest that neutral molecular markers may not have the sensitivity required to detect isolation between these recently established taxa.

Animals↗
PubMed2003

[Research progress in forest tree genetic linkage map construction and its future prospects].

The research progress in genetic linkage map construction of forest tree species both at home and abroad were reviewed in the paper. Two main problems involved in the field were discussed. One was the limitation of the number of individuals of mapping populations and the other was the random markers mostly employed by the majority of studies. These problems have resulted in crossing combination specificity in the constructed maps and the QTLs located on the basis of the maps. As a result,the QTLs discovered up to now have low credibility and poor practicability in marker-assisted selection. Therefore considering the biological characteristics of forest tree species,the selection of the most suitable genetic markers is crucial to obtain a high quality genetic linkage map, and it is both important and necessary to carry out comparative genetic mapping. Progress in the ongoing expressed sequence tag (EST) sequencing projects were summarized and EST polymorphism (ESTP), the most informative and highly conservative marker with known function,as well as the main ESTP detection techniques were elaborated. It was pointed out that ESTP markers should be integrated into the present studies of genetic linkage map construction, QTL mapping and genome comparative mapping. Finally the future prospects in the fields of genetic linkage map and QTL mapping were discussed. In China, such studies around Populus, especially in the local Populus species should make a breakthrough in the related fields.

English Abstract↗
PubMed1999

Regional Representativeness of Swedish Reference Lakes.

/ Recent focus has been placed on ecoregion delineations for providing an appropriate framework for monitoring and assessment of region-specific attainable water/habitat quality. Using an ecoregion approach to stratify variance, this study was conducted to determine whether earlier (subjectively) selected Swedish reference lakes may be considered as regionally representative reference sites when compared with a randomly selected lake population. Predictive modeling by discriminant function analysis with lakes classified by ecoregion and lake surface area and six physicochemical variables showed that the greater majority of reference lakes may be considered as regionally representative. The highest proportion of lake "misclassifications" occurred in the boreonemoral ecoregion, a relatively diverse ecoregion of southern Sweden. This apparent bias may be in part be due to the criteria used in selecting regional reference lakes. In the earlier selection of reference lakes emphasis was placed on lakes not being adversely affected by land usage or pollutant discharges, consequently forest lakes were often overrepresented and sites in agricultural areas underrepresented in the selected reference sites. As a complement to predictive modeling, PCA ordination showed the placement of reference lakes within the random lake population and indicated where reference sites might be missing along potentially important ecological gradients. KEY WORDS: Regionalization; Ecoregion; Representativeness; Reference; Ordination; Modeling; Temperate lakes

Journal Article↗
PubMed2003

In vivo effects of fluoroquinolones on rabbit corneas.

PURPOSE: The use of topical fluoroquinolones to treat microbial keratitis is associated with an increased incidence of corneal perforation compared to other standard treatments. This study examined the effects of topical fluoro-quinolones on corneal collagen and keratocytes in intact rabbit corneas and corneas with an epithelial defect. METHODS: Studies consisted of one group of intact corneas and one group of corneas where a 6-mm epithelial defect was created with a surgical scrape. Within each group, eyes were randomly assigned to one of four topical medications (0.3% ciprofloxacin, 0.3% ofloxacin, fortified antibiotics (1.36% tobramycin, 5% cefrazolin) or Tears Naturale (Alcon Laboratories, Frenchs Forest, NSW, Australia). Two drops were instilled hourly for 48 h and then 2-hourly for an additional 48 h. At 96 h the corneas were removed and processed for light microscopy, immunohistology for collagen IV, V and VI, and apoptosis staining. RESULTS: In intact rabbit corneas there was no demonstrable difference between treatment groups. In corneas with an epithelial defect, both fluoroquinolones delayed epithelial healing when compared to fortified antibiotics or tears. Keratocyte loss was seen in all groups and was greatest in the ofloxacin group. Median stromal thickness with keratocyte loss were: ofloxacin 30%; ciprofloxacin 10%; fortified antibiotics 7.5%; and tears 15% (ofloxacin vs tears, Mann-Whitney = 16.0, P = 0.09). Keratocyte loss did not correlate with the amount of demonstrable apoptosis. Collagens IV, V and VI showed no differences between treatments. CONCLUSIONS: These results suggest that ofloxacin is potentially cytotoxic to corneal keratocytes. Such an effect could lead to the observed increased incidence of corneal perforation in microbial keratitis.

Administration, Topical↗
PubMed2005

[Population structure and community characteristics of Pseudotaxus chienii in Fengyangshan National Natural Reserve].

Pseudotaxus chienii, an endemic plant in China, is one of the second grade state protection wild plants, and distributes in Fengyangshan Natural Reserve as one of its concentrative dwelling places. A survey in the region was carried out on 10 communities, which were dominated by P. chienii. The analysis on its size structure, spatial distribution pattern and community characteristics showed that the populations of P. chienii could grow in the communities dominated by Rhododendron simiarum, Fokienia hodginsii-R. simiarum, and evergreen broad-leaved forests. In R. simiarum communities, the size structure, survival curve, and overwhelming community distribution pattern of P. chienii showed a sustaining development, while in communities dominated by F. hodginsii-R. simiarum, though the size structure was declining, the survival curve was Deevy- III type. Plenty of plantlets were still existed, and the populations kept steady. Two types were considered to be the most suitable ones for P. chienii populations. The important value of P. chienii reached 5% - 10%. In evergreen broad-leaved forests, the populations of P. chienii showed to be a declining type, and the survival curve was Deevy- II type. The distribution pattern was random, indicating that P. chienii populations could not fit for survive in this kind of communities. Correlation analysis showed that P. chienii populations had a positive correlation with R. simiarum and F. hodginsii, but a negative correlation with Cyclobalanopsis stewardiana and Schima superba. P. chienii could associate to the habits with the community canopy density of about 0.6 - 0.8. From the results mentioned above, the populations of P. chienii could be able to sustain and develop, and the existing habitat in Fengyangshan should be protected effectively. The protection of P. chienii requires more basic work to establish efficient measures to protect its habitat.

China↗
PubMed2002

Climatic effects on microsatellite diversity in wild emmer wheat (Triticum dicoccoides) at the Yehudiyya microsite, Israel.

Microsatellite (SSR) diversity at 28 loci comprising seven types of tandem dinucleotide repeated motifs was analyzed in 105 individual plants of wild emmer wheat, Triticum dicoccoides, from a microsite in Yehudiyya, northeast of the Sea of Galilee, Israel. The study area was less than 1000 m(2) and involved 12 paired plots distributed in a mosaic pattern. Each experiment involved very close (a few meters apart), but sharply divergent, microclimatic niches in the open park forest of Tabor oak: (1) sun, between trees, and (2) shade, under tree canopy. Significant microclimatic divergence characterized many loci displaying asymmetric and non-random distribution of repeat numbers. Niche-specific and niche-unique alleles and linkage disequilibria were found in the two sub-populations. Microsatellite diversity at both single- and two-locus levels is affected by microclimatic environment. The evidence reflects effects of ecological stresses and natural selection on SSR diversity, resulting presumably in adaptive structures.

Climate↗
PubMed2005

Field ecology of sylvatic Rhodnius populations (Heteroptera, Triatominae): risk factors for palm tree infestation in western Ecuador.

Most Rhodnius species (Triatominae) are primarily associated with palm trees. They maintain enzootic Trypanosoma cruzi transmission and are responsible for human infection (causing Chagas disease) through the Neotropics. Assessing whether individual palm traits (ecological and/or botanical) may increase the risk of palm infestation by triatomines is relevant in areas where bugs invade houses flying from peridomestic palms. We developed a novel fieldwork approach with that objective, and applied it to study infestation by sylvatic Rhodnius ecuadoriensis in 110 tagua palms (Phytelephas aequatorialis). Palm infestation (23% overall) was non-randomly distributed in our sample. Palms located in anthropic landscapes were frequently infested (>27%, n=92), whereas no bugs were collected from palms surveyed within forest remnants (n=18; P=0.01). The presence of abundant decaying vegetable matter (P=0.001) and (to a lesser extent) epiphytic plants (P=0.049) on palm crowns and stems increased the probability of infestation and was positively correlated with the apparent density of bug colonies (R2=0.68). A trend towards higher infestation rates in male palms (34% vs. 18%) could relate to female palm management (removal of infrutescences and vegetable debris) in areas where palm seeds are harvested. An outline of 'risk palm ecotopes' and environmental management-based strategies for the control of peridomestic, palm tree-living vector populations are proposed.

Animals↗
PubMed2003

Genetic diversity of an ectomycorrhizal fungus Tricholoma terreum in a Larix principis-rupprechtii stand assessed using random amplified polymorphic DNA.

The genetic variation and spatial distribution of the ectomycorrhizal fungus Tricholoma terreum was studied in an artificial Larix principis-rupprechtii stand in China. The 33 sporophores studied belonged to distinct genotypes, based on analysis of random amplified polymorphic DNA (RAPD) markers. The genets of T. terreum were small and no larger than 0.5 m. Two major phenetic groups, i.e. eight individuals in group 1 and 25 in group 2, were identified by principal component analysis and the unweighted pair group method with arithmetic means of simple matching coefficients, respectively. The genetic diversity as determined by the Shannon-Weaver diversity index was 4.52 for these 33 sporophores. Furthermore, there was a slightly lower diversity index in group 1 (4.28) than in group 2 (4.46). It is suggested that sexual spore propagation is very important in the life history of T. terreum in this larch forest.

Agaricales↗
PubMed2001

Local abundance and regional distribution of tree species of forest fragments in Brazil: a test of models.

Patterns of local abundance and regional distribution of tree species were analyzed on three spatial scales and compared with those predicted by Hanski's 1982 original core-satellite model, Brown's 1984 niche-based model, and Tokeshi's 1992 model. Data were collected in seven forest fragments dispersed over approximately 7200 km2, remnants of a former continuous forest in the south of Mato Grosso do Sul state, southwestern Brazil. Fifty-six east-west-oriented 10 m yen 150 m plots were randomly demarcated in those fragments from 1994 to 1996. In each plot all trees having DBH > or = 0.15 m were recorded and measured. The smallest scale was that of the fragments themselves and the greatest was that of the entire region. No evidence was found of the bimodality predicted by Hanski's 1982 model on any scale. On all scales, an unimodal pattern was found whose mode was on the left side (satellite mode) of the distribution. This pattern was in best agreement with the predictions of Tokeshi's 1992 model.

Brazil↗