bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plant population and community responses to removal of dominant species in the shortgrass steppe
Authors: Munson Seth M. , Lauenroth William K. 
Published: March 2009

AbstractQuestion: What are the plant population‐ and community‐level effects of removal of dominant plant species in the shortgrass steppe?Location: The Shortgrass Steppe Long‐Term Ecological Research site in northern Colorado, USA.Methods: We annually measured plant cover and density by species for 10 years after a one‐time aboveground removal of the dominant perennial grass, Bouteloua gracilis. Removal and control plots (3 m × 3 m) were within grazed and ungrazed locations to assess the influence of grazing on recovery dynamics. Our analyses examined plant species, functional type, and community responses to removal, paying special attention to the dynamics of subdominant and rare species.Results: Basal cover of B. gracilis increased by an average of 1% per year, but there was significantly less plant cover in treatment compared to control plots for 5 years following removal. In contrast to the lower cover in treatment plots, the plant density (number of plants m−2) of certain subdominant perennial grasses, herbaceous perennial and annual forbs, a dwarf shrub, and cactus increased after removal of the dominant species, with no major change in species richness (number of species per 1 m × 1 m) or diversity. Subdominant species were more similar between years than rare species, but dominant removal resulted in significantly lower similarity of the subdominant species in the short term and increased the similarity of rare species in the long term.Conclusions: Removal of B. gracilis, the dominant perennial grass in the shortgrass steppe, increased the absolute density of subdominant plants, but caused little compensation of plant cover by other plants in the community and changes in species diversity.
Sexual Dysfunction in Men Who Abuse Illicit Drugs: A Preliminary Report
Authors: Bang-Ping Jiann 
Published: March 2009

ABSTRACT

Introduction
Despite being seen as aphrodisiacs, illicit drugs are reported to have detrimental effects on male sexual function but most studies have been based on small case numbers with ambiguous results.

Aims
To assess the impact of illicit drugs abuse on male sexual function.

Main Outcome Measures
International Index of Erectile Function (IIEF) and global assessment questions.

Methods
Illicit drug abusers in a Drug Abstention and Treatment Center were recruited to complete the questionnaires and their data were compared with an age-matched control.

Results
The abusers (N = 701, mean age 33.8 years) had a lower mean IIEF score in each domain than that of the controls (N = 196, mean age 35.4 years). Heroin, amphetamine, and MDMA (“Ecstasy”) were the leading drugs used. Erectile dysfunction (ED) was reported in 36.4% of the abusers and the odds ratio of having ED (compared with the controls) in mono-users of heroin, amphetamine, and MDMA was 4.8 (P &lt; 0.05), 3.2 (P &lt; 0.05), and 1.4 (P &gt; 0.05), respectively. Of the abusers, 38.6% reported to have decreased sexual desire with illicit drug use, more often seen in the heroin mono-users (46.7%), and 18.4% reported to have enhanced sexual desire, more often seen in the amphetamine mono-users (22.6%). Mean IIEF sexual desire domain score of the abusers was lower than that of the control, even for those who reported to have enhanced sexual desire. Increased and decreased ejaculation latency affected by illicit drugs was reported in 49.9 and 14.3%, respectively, of the abusers, showing no significant difference among the mono-users of three different drugs.

Conclusions
Illicit drug male abusers were prone to have ED, decreased sexual desire, and increased ejaculation latency. ED and decreased sexual desire were most commonly seen in heroin, followed by amphetamine and MDMA mono-users, while increased ejaculation latency occurred commonly in all of the abusers.
The Sexuality and Quality of Life of Hemodialyzed Patients—ASED Multicenter Study
Authors: Lew-Starowicz Michal , Gellert Ryszard 
Published: March 2009

ABSTRACT

Introduction
Chronic kidney disease (CKD) strongly affects sexual function (SF) and quality of life (QoL). The relations between CKD, SF, mental health, and QoL remain poorly understood in dialyzed patients.

Aim
To correlate sexuality to QoL in hemodialysis patients.

Methods
One hundred twelve patients (69 males and 43 females) aged 20–60 years at six dialysis units were interviewed, and their medical records were reinvestigated and supplemented with completed Beck’s Depression Inventory, Self-Evaluation Questionnaire, Mell–Krat Scale, International Index of Erectile Function-5, Arizona Sexual Experience Scale, and health-related Quality of Life (Short Form [SF]-36) questionnaires.

Main Outcome Measures
Prevalence of different levels of measurable aspects of sexual life, mental health, QoL, as well as their correlations, was assessed.

Results
Only 55.4% of the patients were sexually active (79% in the age-matched general population) and 24.1% has ever before spoken to a doctor about their sexual life. The patients perceived sexual activity as important and were not satisfied with the performance. The predominant sexual dysfunctions were loss or diminished sexual needs (84.7% males and 48.8% females); in men, also erectile dysfunction (44.5%) and inhibited or lack of ejaculation (51.5%); in women, arousal dysfunction and anorgasmia (67.8% and 80.7%, respectively). The rate of depression was extremely high (80.5%). The patients self-assessed their QoL as low in both the physical and the mental health domains. Multiple regression analysis revealed that anxiety in men and depression in women independently predicted the lower quality of sexual life (P = 0.017 and 0.04, respectively). The general QoL, mental health, and physical health negatively correlated with the presence of depressive symptoms (P = 0.011, 0.013, and 0.011, respectively).

Conclusions
This pilot study is the first to present, in a multicenter design, the complex relations of sexuality and QoL in hemodialyzed patients, which are strongly underevaluated by medical professionals. It supports a thesis that sexual disability correlates with depression and anxiety, and seriously impacts the QoL in dialyzed patients.
Controversies in Sexual Medicine: Is There a Place for Conservative Treatment in Peyronie’s Disease?
Authors: Vardi Yoram , Levine Laurence A. , Chen Juza , Hatzimouratidis Konstantinos , Sohn Michael 
Published: March 2009

ABSTRACT

Introduction
Peyronie’s disease (PD) is a relatively common disorder affecting middle aged men. Conservative nonsurgical treatments include oral, topical, and intra-lesional pharmacotherapies, vacuum stretching, and mechanical traction.

Methods
Four people with expertise and/or interest in the area of PD were asked to contribute their opinions with regard to the safety and efficacy of nonsurgical conservative treatments.

Main Outcome Measure
To provide food for thought, discussion, and possible further research in a poorly discussed area of sexual medicine.

Results
Of the four experts writing on the topic, one believes a combination of medical therapy and penile traction has positive potential for curvature. Another feels that although medical therapies have potential to alleviate pain, there is little evidence to show that they help with curvature or that penile traction helps. A third expert proposes dividing the disease into phases, where patients in the acute phase may benefit from conservative therapy, whereas patients whose disease is stable require surgical intervention. The last expert agrees that the therapy should depend on the stage of the disease, but believes like the first expert that there is a role for traction therapy for patients with stable disease.

Conclusion
There is a need for guidelines for nonsurgical therapies for patients with PD, but there is a paucity of evidence as to their efficacy.
Ecological studies on Cyperus difformis, Cyperus iria and Fimbristylis miliacea: three troublesome annual sedge weeds of rice
Authors: Chauhan B.S. , Johnson D.E. 
Published: March 2009

Abstract Cyperus difformis, Cyperus iria and Fimbristylis miliacea are troublesome annual sedges of rice grown in many countries. Laboratory and screenhouse experiments were conducted to determine the effects of temperature, light, salt and water stress, seed burial depth, and flooding time, duration and depth on germination, emergence and growth of these three species. Germination of all the three species was stimulated by light and warm fluctuating temperatures. Germination of C. difformis was influenced to a greater degree by increasing salt and water stress than C. iria and F. miliacea. In all three species, seeds sown on the soil surface gave the greatest percentage of seedling emergence, and no seedlings emerged from seeds buried in soil at depths of ≥1 cm. Flooding, although not continuous or deep, had a suppressive effect on emergence and growth of C. iria and F. miliacea. Intermittent flooding to shallow depths, however, was less effective in controlling C. difformis; deep flooding was needed to suppress growth of C. difformis seedlings. When the flooding was delayed to 21 days after sowing, there was little growth reduction in all three species.
Influence of minisett sizes on dry matter accumulation and fresh tuber yield of white Guinea yam (Dioscorea rotundata)
Authors: Law‐Ogbomo K.E. , Remison S.U. 
Published: March 2009

AbstractStudies were conducted in 2005 and 2006 at Irrua, Nigeria, to determine the performance of various sizes of minisetts of Dioscorea rotundata cv. ‘Obiaoturugo’ evaluated for size and yield of yield matter and seed yams. These trials involved a macrosett (250 g) and six minisett sizes (25, 30, 35, 40, 45 and 50 g) in a randomised block design with four replicates. The results indicated that larger minisetts had higher degree of field establishment, foliation, leaf area index, total dry weight, percentage of leaf dry matter and net assimilation rate. These growth parameters influenced higher crop growth rate, which was responsible for higher fresh tuber yield. The macrosett’s fresh tuber yield was the greatest (20.48 t ha−1) but had the least multiplication ratio (8.19). The greatest multiplication ratio was obtained from 30‐g setts.
Performance Trade‐offs Driven by Morphological Plasticity Contribute to Habitat Specialization of Bornean Tree Species
Authors: Dent Daisy H. , Burslem David F. R. P. 
Published: March 2009

ABSTRACTGrowth‐survival trade‐offs play an important role in niche differentiation of tropical tree species in relation to light‐gradient partitioning. However, the mechanisms that determine differential species performance in response to light and soil resource availability are poorly understood. To examine responses to light and soil nutrient availability, we grew seedlings of five tropical tree species for 12 mo at < 2 and 18 percent full sunlight and in two soil types representing natural contrasts in nutrient availability within a lowland dipterocarp forest in North Borneo. We chose two specialists of nutrient‐rich and nutrient‐poor soils, respectively, and one habitat generalist. Across all species, growth was higher in high than low light and on more nutrient rich soil. Although species differed in growth rates, the ranking of species, in terms of growth, was consistent across the four treatments. Nutrient‐rich soils improved seedling survival and increased growth of three species even under low light. Slower‐growing species increased root allocation and reduced specific leaf area (SLA) and leaf area ratio (LAR) in response to decreased nutrient supply. All species increased LAR in response to low light. Maximum growth rates were negatively correlated with survival in the most resource‐limited environment. Nutrient‐poor soil specialists had low maximum growth rates but high survival at low resource availability. Specialists of nutrient‐rich soils, plus the habitat generalist, had the opposite suite of traits. Fitness component trade‐offs may be driven by both light and belowground resource availability. These trade‐offs contribute to differentiation of tropical tree species among habitats defined by edaphic variation.
A Lepidopteran defoliator attack on Brazil nut trees (Bertholletia excelsa) in Central Amazonia, Brazil
Authors: Haugaasen Torbjørn 
Published: March 2009

ABSTRACTThis paper describes a severe outbreak of a Lepidopteran defoliator,Lusura altrix(Stoll 1782), on Brazil nut trees in Central Amazonia. The pest outbreak appeared to succeed abnormal weather conditions, and defoliation was sufficient to disrupt normal phenological patterns.
Varying Ecological Quality Influences the Probability of Polyandry in White‐handed Gibbons (Hylobates lar) in Thailand
Authors: Savini Tommaso , Boesch Christophe , Reichard Ulrich H. 
Published: March 2009

ABSTRACTAlthough members of the family Hylobatidae are known to be monogamous, adult white‐handed gibbons (Hylobates lar) at Khao Yai National Park, Thailand, also show multimale groups and polyandry. A need for more than one male to successfully raise offspring cannot explain the occurrence of polyandry in these territorial primates, because direct paternal care is absent in this species. We hypothesize that polyandry is primarily related to costs/benefits for males of cooperatively defending a female and/or resources; our prediction was that polyandry would become more frequent with increasing costs of female/resource defense. We measured the ecological quality of seven gibbon home ranges over a 3‐yr period (2001–2003) to investigate how resource availability affected the probability of polyandry, and found a significant negative relationship between home range quality and home range size. Larger home ranges were of lower quality. As predicted, groups living on larger, poorer home ranges also experienced longer periods of polyandry. In forest areas of comparatively low quality, acquiring and maintaining a large home range that includes enough resources for a female to reproduce steadily may surpass a single male's capacity. Our model of cooperative male polyandry was supported by preliminary data of shared territorial defense and access to the female. However, interaction proportions were strongly skewed, and female's primary male partners monopolized grooming and mating. Nevertheless, a primary male on a large territory may benefit from the presence of a secondary male with aid in territorial/female defense, whereas a secondary male may gain by avoiding high dispersal costs.
Studying Animal Diets In Situ Using Portable Stable Isotope Analyzers
Authors: Voigt Christian C. 
Published: March 2009

ABSTRACTI assessed the usefulness of a portable stable isotope analyzer for assigning animals to food chains of tropical ecosystems. Based on the stable carbon isotope ratio of the animals’ breath (δ13Cbreath), it was possible to distinguish between the isotopically distinct food chains of fruit‐eating bats and blood‐eating vampire bats. Portable instruments for the analysis of δ13Cbreath may improve our ability to quantify animal diets, because they are accurate and cheap, and most importantly they can be used in situ.
Conservation of Vascular Epiphyte Diversity in Shade Cacao Plantations in the Chocó Region of Ecuador
Authors: Haro‐Carrión Xavier , Lozada Tannya , Navarrete Hugo , de Koning G. H. J. 
Published: March 2009

ABSTRACTTo assess the contributions of rustic shade cacao plantations to vascular epiphyte conservation, we compared epiphyte species richness, abundance, composition, and vertical distributions on shade trees and in the understories of six plantations and adjacent natural forests. On three phorophytes and three 10 × 10 m understory plots in each of the agroforestry plantations and natural forests, 54 and 77 species were observed, respectively. Individual‐based rarefaction curves revealed that epiphyte species richness was significantly higher on forest phorophytes than on cacao farm shade trees; detailed analyses showed that the differences were confined to the inner and outer crown zones of the phorophytes. No differences in epiphyte species richness were found in understories. Araceae, Piperaceae, and Pteridophyta were less species‐rich in plantations than in forests, while there were no differences in Orchidaceae and Bromeliaceae. Regression analysis revealed that epiphyte species richness on trunks varied with canopy cover, while abundance was more closely related to soil pH, canopy cover, and phorophyte height. For crown epiphytes, phorophyte diameter at breast height (dbh) explained much of the variation in species richness and abundance. There were also pronounced downward shifts in the vertical distributions of epiphyte species in agroforests relative to natural forests. The results confirm that epiphyte diversity, composition, and vertical distributions are useful indicators of human disturbance and showed that while the studied plantations serve to preserve portions of epiphyte diversity in the landscape, their presence does not fully compensate for the loss of forests.
Comparing the Dispersal of Large‐seeded Tree Species by Frugivore Assemblages in Tropical Montane Forest in Africa
Authors: Gross‐Camp Nicole D. , Mulindahabi Felix , Kaplin Beth A. 
Published: March 2009

ABSTRACTWe examined frugivore visitation and seed dispersal of five large‐seeded (≥ 5 mm) tree species in tropical montane forest based on their occurrence in frugivorous primate diets: Ekebergia capensis, Olea capensis, Parinari excelsa, Prunus africana, and Syzygium guineense. A total of 21 frugivores in five assemblages (i.e., chimpanzees, cercopithecines, large‐bodied birds, small‐bodied birds, and squirrels) were observed over the study period (August 2006 and October–April 2007). We observed seed dispersal in four of five tree species studied; no dispersal was observed for P. excelsa. Frugivore assemblages did not visit tree species equally. Primates spent the most time in trees and had the largest group size. Large‐bodied birds (LB) and chimpanzees dispersed the highest number of seeds per minute. LB and cercopithecines potentially dispersed the greatest number of seeds for E. capensis, and chimpanzees for S. guineense. Our analyses indicated that the mean fruiting duration of the focal tree, time in the tree, and number of species present are important predictor variables for seed dispersal by small‐ and large‐bodied birds, and cercopithecines. The number of fruiting trees in the immediate vicinity of the focal tree further predicted seed dispersal for small‐bodied birds (SB). Large‐bodied birdseed dispersal also was predicted by time in tree by SB, and the number of individuals for SB and cercopithecines. Cercopithecines (CS) were further explained by the time in tree and number of species (SB & LB), and number of individuals for CS. Our study highlights the complexity of describing the relative importance of a frugivore assemblage to the dispersal of a tree species seeds.
Combining Biogeographic and Phylogenetic Data to Examine Primate Speciation: An Example Using Cercopithecin Monkeys
Authors: Kamilar Jason M. , Martin Sara K. , Tosi Anthony J. 
Published: March 2009

ABSTRACTWe combined phylogenetic and biogeographic data to examine the mode of speciation in a group of African monkeys, the Cercopithecini. If allopatric speciation is the major force producing species, then there should be a positive relationship between the relative divergence time of taxa and their degree of geographic range overlap. Alternatively, an opposite relationship between divergence time and geographic range overlap is consistent with sympatric speciation as the main mechanism underlying the cercopithecin radiation. We collected biogeographic and phylogenetic data for 19 guenon species from the literature. We digitized geographic range maps and utilized three different phylogenetic hypotheses based on Y chromosome, X chromosome, and mitochondrial (mtDNA) data. We used regressions with Monte Carlo simulation to examine the relationship between the relative time since divergence of taxa and their degree of geographic range overlap. We found that there was a positive relationship between relative divergence time and the proportion of geographic range overlap between taxa using all three molecular data sets. Our findings provide evidence for allopatric speciation being the common mode of diversification in the cercopithecin clade. Because most of these primates are forest adapted mammals, the cyclical contraction and expansion of African forests from the late Miocene to the present has likely been an important factor driving allopatric speciation. In addition, geographic barriers such as the Congo and Sanaga rivers have probably played a complementary role in producing new species within the clade.
The extended X-ray emission around HDF130 at z = 1.99: an inverse Compton ghost of a giant radio source in the Chandra Deep Field-North
Authors: Fabian A. C. , Chapman S. , Casey C. M. , Bauer F. , Blundell K. M. 
Published: March 2009

Abstract
One of the six extended X-ray sources found in the Chandra Deep Field-North is centred on Hubble Deep Field (HDF) 130, which has recently been shown to be a massive galaxy at z = 1.99 with a compact radio nucleus. The X-ray source has a roughly double-lobed structure with each lobe about 41-arcsec long, or 345 kpc at the redshift of HDF 130. We have analysed the 2 Ms X-ray image and spectrum of the source and find that it is well fit by a power-law continuum of photon index 2.65 and has a 2–10 keV luminosity of 5.4 × 1043 erg s−1 (if at z = 1.99). Any further extended emission within a radius of 60 arcsec has a luminosity less than half this value, which is contrary to what is expected from a cluster of galaxies. The source is best explained as an inverse Compton ghost of a giant radio source, which is no longer being powered, and for which Compton losses have downgraded the energetic electrons, γ &gt; 104, required for high-frequency radio emission. The lower energy electrons, γ∼ 1000, produce X-rays by inverse Compton scattering on the cosmic microwave background. Depending on the magnetic field strength, some low-frequency radio emission may remain. Further inverse Compton ghosts may exist in the Chandra Deep Fields and beyond.
HD 271791: dynamical versus binary-supernova ejection scenario
Authors: Gvaramadze V. V. 
Published: March 2009

Abstract
The atmosphere of the extremely high-velocity (530–920 km s−1) early B-type star HD 271791 is enriched in α-process elements, which suggests that this star is a former secondary component of a massive tight binary system and that its surface was polluted by the nucleosynthetic products after the primary star exploded in a supernova. It was proposed that the (asymmetric) supernova explosion unbind the system and that the secondary star (HD 271791) was released at its orbital velocity in the direction of Galactic rotation. In this Letter, we show that to explain the Galactic rest-frame velocity of HD 271791 within the framework of the binary-supernova scenario, the stellar remnant of the supernova explosion (a ≲10 M⊙ black hole) should receive an unrealistically large kick velocity of ≥750–1200 km s−1. We therefore consider the binary-supernova scenario as highly unlikely and instead propose that HD 271791 attained its peculiar velocity in the course of a strong dynamical three- or four-body encounter in the dense core of the parent star cluster. Our proposal implies that by the moment of encounter HD 271791 was a member of a massive post-supernova binary.