bluuebunny/crossref_metadata_2025_split huggingface dataset:
Criteria for Defining Polycystic Ovary Syndrome as a Predominantly Hyperandrogenic Syndrome: An Androgen Excess Society Guideline
Authors: Azziz Ricardo , Carmina Enrico , Dewailly Didier , Diamanti-Kandarakis Evanthia , Escobar-Morreale Hector F. , Futterweit Walter , Janssen Onno E. , Legro Richard S. , Norman Robert J. , Taylor Ann E. , Witchel Selma F. 
Published: August 2006

Abstract
Objective: The Androgen Excess Society (AES) charged a task force to review all available data and recommend an evidence-based definition for polycystic ovary syndrome (PCOS), whether already in use or not, to guide clinical diagnosis and future research.
Participants: Participants included expert investigators in the field.
Evidence: Based on a systematic review of the published peer-reviewed medical literature, by querying MEDLINE databases, we tried to identify studies evaluating the epidemiology or phenotypic aspects of PCOS.
Consensus Process: The task force drafted the initial report, following a consensus process via electronic communication, which was then reviewed and critiqued by the AES Board of Directors. No section was finalized until all members were satisfied with the contents and minority opinions noted. Statements that were not supported by peer-reviewed evidence were not included.
Conclusions: Based on the available data, it is the view of the AES Task Force on the Phenotype of PCOS that there should be acceptance of the original 1990 National Institutes of Health criteria with some modifications, taking into consideration the concerns expressed in the proceedings of the 2003 Rotterdam conference. A principal conclusion was that PCOS should be first considered a disorder of androgen excess or hyperandrogenism, although a minority considered the possibility that there may be forms of PCOS without overt evidence of hyperandrogenism but recognized that more data are required before validating this supposition. Finally, the task force recognized, and fully expects, that the definition of this syndrome will evolve over time to incorporate new research findings.
Improved Triglycerides and Insulin Sensitivity with 3 Months of Acipimox in Human Immunodeficiency Virus-infected Patients with Hypertriglyceridemia
Authors: Hadigan Colleen , Liebau James , Torriani Martin , Andersen Rebecca , Grinspoon Steven 
Published: August 2006

Abstract
Context: Metabolic abnormalities such as hypertriglyceridemia remain a challenge for optimizing long-term health in HIV-infected patients.
Objective: Elevation of free fatty acids (FFAs) may contribute to hyperlipidemia and insulin resistance in HIV. We evaluated the efficacy and safety of chronic inhibition of lipolysis in HIV-infected men and women with hypertrigyceridemia. We hypothesized that acipimox would lead to significant reductions in triglycerides and improved insulin sensitivity, compared with placebo.
Design: A 3-month, randomized, double-blind, controlled trial of acipimox (250 mg thrice daily) vs. placebo was conducted in 23 HIV-infected men and women with hypertriglyceridemia (&gt;150 mg/dl), abnormal fat distribution, and no current lipid-lowering therapy. The primary outcome variable was triglyceride concentration, and insulin sensitivity measured by hyperinsulinemic euglycemic clamp was a secondary outcome.
Setting: The study was conducted at an academic medical center.
Results: Acipimox resulted in significant reductions in FFAs [mean change −0.38 (0.06) vs. 0.08 (0.06) mEq/liter with placebo, −68 vs. +17% change from mean baseline, P &lt; 0.0001], decreased rates of lipolysis (P &lt; 0.0001), and a median triglyceride decrease from 238 mg/dl at baseline to 190 mg/dl, compared with an increase from 290 to 348 mg/dl in the placebo group (P = 0.01). Acipimox improved insulin sensitivity [acipimox +2.31 (0.74) vs. placebo −0.21 (0.90) mg glucose per kilogram lean body mass per minute, or +31 vs. −2% change from mean baseline values, P = 0.04]. Improvements in insulin sensitivity were significantly correlated with reductions in FFAs (r = −0.62, P = 0.003) and lipolysis (r = −0.59, P = 0.005).
Conclusions: Acipimox resulted in significant sustained reductions in lipolysis, improved glucose homeostasis, and significant but modest reductions in triglycerides in HIV-infected individuals with abnormal fat distribution and hypertriglyceridemia. Improvement in overall metabolic profile with acipimox suggests a potential clinical utility for this agent that requires further investigation.
Testosterone Gel Combined with Depomedroxyprogesterone Acetate Is an Effective Male Hormonal Contraceptive Regimen and Is Not Enhanced by the Addition of a GnRH Antagonist
Authors: Page Stephanie T. , Amory John K. , Anawalt Bradley D. , Irwig Michael S. , Brockenbrough Andrew T. , Matsumoto Alvin M. , Bremner William J. 
Published: August 2006

Abstract
Introduction: Exogenous androgens plus progestins can be used to suppress spermatogenesis, resulting in effective male hormonal contraception; however, induction of azoospermia can require 3–6 months, and these methods require injectable or implantable androgens. We hypothesized that testosterone (T) transdermal gel (T gel) could be combined with a depot formulation of the progestin, depomedroxyprogesterone acetate (DMPA), with or without the potent GnRH antagonist, acyline, to suppress spermatogenesis conveniently, rapidly, and reversibly.
Objectives: The objectives of the study were: 1) to determine the rate of severe oligospermia (≤1 million sperm/ml) using T gel+DMPA; and 2) to determine whether the addition of acyline to T gel+DMPA during the first 12 wk of the regimen would accelerate and improve suppression of spermatogenesis.
Methods: Forty-four healthy men, ages 18–55 yr, were randomized to T gel (100 mg daily)+DMPA (300 mg/3 months) or acyline (300 μg/kg·2 wk × 12 wk)+T gel+DMPA. Thirty-eight men completed the 24-wk treatment protocol.
Results: All men had dramatic suppression of spermatogenesis; 90% of the subjects became severely oligospermic, a rate comparable to implantable and injectable T+progestin combinations. The addition of acyline did not significantly accelerate spermatogenic suppression or improve rates of severe oligospermia. There were no serious adverse events, and there were minimal changes in weight, serum lipids, and prostate-specific antigen.
Conclusions: The combination of T gel+DMPA is a promising new regimen in male contraception. The addition of the GnRH antagonist acyline, as part of an induction phase in a male contraception regimen, has limited clinical utility. Additional studies using T gel for male contraception are warranted.
Uncertainty about nest position influences systematic search strategies in desert ants
Authors: Merkle Tobias , Knaden Markus , Wehner Rüdiger 
Published: August 2006

SUMMARY
Foraging desert ants return to their starting point, the nest, by means of path integration. If the path-integration vector has been run off but the nest has not yet been reached, the ants engage in systematic search behavior. This behavior results in a system of search loops of ever increasing size and finally leads to a search density profile peaking at the location where the path integration system has been reset to zero. In this study we investigate whether this systematic search behavior is adapted to the uncertainty resulting from the preceding foraging run. We show first that the longer the distances of the foraging excursions, the larger the errors occurring during path integration, and second that the ants adapt their systematic search strategy to their increasing uncertainty by extending their search pattern. Hence, the density of the systematic search pattern is correlated with the ants' confidence in their path integrator. This confidence decreases with increasing foraging distances.
Size discrimination of hollow hemispheres by echolocation in a nectar feeding bat
Authors: Simon Ralph , Holderied Marc W. , von Helversen Otto 
Published: August 2006

SUMMARY
Nectar feeding bats use echolocation to find their flowers in the dense growth of tropical rainforests, and such flowers have evolved acoustic features that make their echo more conspicuous to their pollinators. To shed light on the sensory and cognitive basis of echoacoustic object recognition we conducted a size discrimination experiment with the nectarivorous bat Glossophaga soricina and compared the bats' behavioural performance with the echoic features of the training objects.
We chose a simple geometric form, the hollow hemisphere, as the training object because of its resemblance to the bell-shaped concave form of many bat flowers, as well as its special acoustic qualities. The hemispheres showed a characteristic echo pattern, which was constant over a wide range of angles of sound incidence. We found systematic size-dependent changes in the echo's temporal and spectral pattern as well as in amplitude.
Bats were simultaneously confronted with seven different sizes of hollow hemispheres presented from their concave sides. Visits to one particular size were rewarded with sugar water, while we recorded the frequency of visits to the unrewarded hemispheres. We found that: (1) bats learned to discriminate between hemispheres of different size with ease; (2) the minimum size difference for discrimination was a constant percentage of the hemisphere's size (Weber fraction: approximately 16% of the radius); (3) the comparison of behavioural data and impulse response measurements of the objects' echoes yielded discrimination thresholds for mean intensity differences (1.3 dB), the temporal pattern (3-22 μs) and the change of spectral notch frequency(approximately 16%). We discuss the advantages of discrimination in the frequency and/or time domain.
Efficiency of antlion trap construction
Authors: Fertin Arnold , Casas Jérôme 
Published: August 2006

SUMMARYAssessing the architectural optimality of animal constructions is in most cases extremely difficult, but is feasible for antlion larvae, which dig simple pits in sand to catch ants. Slope angle, conicity and the distance between the head and the trap bottom, known as off-centring, were measured using a precise scanning device. Complete attack sequences in the same pits were then quantified, with predation cost related to the number of behavioural items before capture. Off-centring leads to a loss of architectural efficiency that is compensated by complex attack behaviour. Off-centring happened in half of the cases and corresponded to post-construction movements. In the absence of off-centring, the trap is perfectly conical and the angle is significantly smaller than the crater angle, a physical constant of sand that defines the steepest possible slope. Antlions produce efficient traps, with slopes steep enough to guide preys to their mouths without any attack, and shallow enough to avoid the likelihood of avalanches typical of crater angles. The reasons for the paucity of simplest and most efficient traps such as theses in the animal kingdom are discussed.
Modeling the electric field of weakly electric fish
Authors: Babineau David , Longtin André , Lewis John E. 
Published: August 2006

SUMMARYWeakly electric fish characterize the environment in which they live by sensing distortions in their self-generated electric field. These distortions result in electric images forming across their skin. In order to better understand electric field generation and image formation in one particular species of electric fish, Apteronotus leptorhynchus, we have developed three different numerical models of a two-dimensional cross-section of the fish's body and its surroundings. One of these models mimics the real contour of the fish; two other geometrically simple models allow for an independent study of the effects of the fish's body geometry and conductivity on electric field and image formation. Using these models, we show that the fish's tapered body shape is mainly responsible for the smooth, uniform field in the rostral region, where most electroreceptors are located. The fish's narrowing body geometry is also responsible for the relatively large electric potential in the caudal region. Numerical tests also confirm the previous hypothesis that the electric fish body acts approximately like an ideal voltage divider; this is true especially for the tail region. Next, we calculate electric images produced by simple objects and find they vary according to the current density profile assigned to the fish's electric organ. This explains some of the qualitative differences previously reported for different modeling approaches. The variation of the electric image's shape as a function of different object locations is explained in terms of the fish's geometrical and electrical parameters. Lastly, we discuss novel cues for determining an object's rostro-caudal location and lateral distance using these electric images.
Dolphin continuous auditory vigilance for five days
Authors: Ridgway Sam , Carder Don , Finneran James , Keogh Mandy , Kamolnick Tricia , Todd Mark , Goldblatt Allen 
Published: August 2006

SUMMARYThe present report describes the first study of continuous vigilance in dolphins. Two adult bottlenose dolphins (Tursiops truncatus), WEN(male) and SAY (female), maintained a very high detection rate of randomly presented, infrequent, 1.5-s target tones in a background of frequent 0.5-s equal-amplitude tones over five continuous 120-h sessions. The animals were able to maintain high levels (WEN 97, 87, 99%; SAY 93, 96%) of target detection without signs of sleep deprivation as indicated by behavior, blood indices or marked sleep rebound during 24 h of continuous post-experiment observation. Target response time overall (F=0.384; P=0.816)did not change between day 1 and day 5. However, response time was significantly slower (F=21.566, P=0.019) during the night(21.00-04.00 h) when the dolphins would have ordinarily been resting or asleep.
Effect of host kairomones and oviposition experience on the arrestment behavior of an egg parasitoid
Authors: Peri Ezio , Sole Mery Angelica , Wajnberg Eric , Colazza Stefano 
Published: August 2006

SUMMARY
Chemical residues left by walking adults of the southern green stink bug, Nezara viridula (L.) (Heteroptera: Pentatomidae) induce arrestment behavior in the egg parasitoid Trissolcus basalis (Wollaston)(Hymenoptera: Scelionidae) leading to prolonged periods of walking on contaminated areas and to systematic return to the stimulus after encountering the treatment borders. In this study, we quantified how the hierarchical value of residues from host adults and oviposition experience can influence the arrestment behavior of T. basalis females. Our results showed that:(1) female wasps perceived host residues at different hierarchical levels depending on the host gender, with a clear preference for the chemical residues deposited by host females rather then host males; (2) wasps'arrestment response to chemical residues of host females became weaker when wasps were not rewarded by an oviposition experience, and stronger following successful oviposition; (3) repeated encounters with host male chemical residues, followed or not by oviposition experience, did not cause wasps to change their innate arrestment response; (4) in the unrewarded condition,arrestment responses of wasps varied according to the time elapsed between successive visits to areas contaminated by host females: responses were weak with a short interval (less than 24 h) and stronger with a long interval (more than 72 h), suggesting that this unrewarded experience, i.e. encounter with female traces not followed by host egg location, fade within a few hours. The potential significance of these results to the host location behavior of T. basalis in the field is discussed.
Noradrenergic modulation of respiratory motor output during tadpole development: role of α-adrenoceptors
Authors: Fournier Stéphanie , Kinkead Richard 
Published: August 2006

SUMMARY
Noradrenaline (NA) is an important modulator of respiratory activity. Results from in vitro studies using immature rodents suggest that the effects exerted by NA change during development, but these investigations have been limited to neonatal stages. To address this issue, we used in vitro brainstem preparations of an ectotherm, Rana catesbeiana,at three developmental stages: pre-metamorphic tadpoles, metamorphic tadpoles and fully mature adult bullfrogs. We first compared the effects of NA bath application (0.02-10 μmol l-1) on brainstem preparations from both pre-metamorphic (Taylor-Köllros stages VII-XI) and metamorphic tadpoles (TK stages XVIII-XXIII) and adult frogs. The fictive lung ventilation frequency response to NA application was both dose- and stage-dependent. Although no net change was observed in the pre-metamorphic group, NA application decreased fictive lung burst frequency in preparations from more mature animals. These effects were attenuated by application ofα-adrenoceptor antagonists. Conversely, NA application elicited dose-and stage-dependent increases in fictive buccal ventilation frequency. We then assessed the contribution of α-adrenoceptors towards these responses by applying specific agonists (α1: phenylephrine;α 2: clonidine; concentration range from 10 to 200 μmol l-1 for both). Of the two agonists used, only phenylephrine application consistently mimicked the lung burst frequency response observed during NA application in each stage group. However, both agonists decreased buccal burst frequency, thus suggesting that other (β) adrenoceptor types mediate this response. We conclude that modulation of both buccal and lung-related motor outputs change during development. NA modulation affects both types of respiratory activities in a distinct fashion, owing to the different adrenoceptor type involved.
Molecular characterization of sodium/proton exchanger 3 (NHE3) from the yellow fever vector,Aedes aegypti
Authors: Pullikuth Ashok K. , Aimanova Karlygash , Kang'ethe Wanyoike , Sanders Heather R. , Gill Sarjeet S. 
Published: August 2006

SUMMARYTransport across insect epithelia is thought to depend on the activity of a vacuolar-type proton ATPase (V-ATPase) that energizes ion transport through a secondary proton/cation exchanger. Although several of the subunits of the V-ATPase have been cloned, the molecular identity of the exchanger has not been elucidated. Here, we present the identification of sodium/proton exchanger isoform 3 (NHE3) from yellow fever mosquito, Aedes aegypti(AeNHE3). AeNHE3 localizes to the basal plasma membrane of Malpighian tubule, midgut and the ion-transporting sector of gastric caeca. Midgut expression of NHE3 shows a different pattern of enrichment between larval and adult stages, implicating it in the maintenance of regional pH in the midgut during the life cycle. In all tissues examined, NHE3 predominantly localizes to the basal membrane. In addition the limited expression in intracellular vesicles in the median Malpighian tubules may reflect a potential functional versatility of NHE3 in a tissue-specific manner. The localization of V-ATPase and NHE3, and exclusion of Na+/K+-ATPase from the distal ion-transporting sector of caeca, indicate that the role of NHE3 in ion and pH regulation is intricately associated with functions of V-ATPase. The AeNHE3 complements yeast mutants deficient in yeast NHEs, NHA1 and NHX1. To further examine the functional property of AeNHE3, we expressed it in NHE-deficient fibroblast cells. AeNHE3 expressing cells were capable of recovering intracellular pH following an acid load. The recovery was independent of the large cytoplasmic region of AeNHE3, implying this domain to be dispensable for NHE3 ion transport function. 22Na+uptake studies indicated that AeNHE3 is relatively insensitive to amiloride and EIPA and is capable of Na+ transport in the absence of the cytoplasmic tail. Thus, the core domain containing the transmembrane regions of NHE3 is sufficient for pH recovery and ion transport. The present data facilitate refinement of the prevailing models of insect epithelial transport by incorporating basal amiloride-insensitive NHE3 as a critical mediator of transepithelial ion and fluid transport and likely in the maintenance of intracellular pH.
Frictional adhesion: a new angle on gecko attachment
Authors: Autumn K. , Dittmore A. , Santos D. , Spenko M. , Cutkosky M. 
Published: August 2006

SUMMARYDirectional arrays of branched microscopic setae constitute a dry adhesive on the toes of pad-bearing geckos, nature's supreme climbers. Geckos are easily and rapidly able to detach their toes as they climb. There are two known mechanisms of detachment: (1) on the microscale, the seta detaches when the shaft reaches a critical angle with the substrate, and (2) on the macroscale, geckos hyperextend their toes, apparently peeling like tape. This raises the question of how geckos prevent detachment while inverted on the ceiling, where body weight should cause toes to peel and setal angles to increase. Geckos use opposing feet and toes while inverted, possibly to maintain shear forces that prevent detachment of setae or peeling of toes. If detachment occurs by macroscale peeling of toes, the peel angle should monotonically decrease with applied force. In contrast, if adhesive force is limited by microscale detachment of setae at a critical angle, the toe detachment angle should be independent of applied force. We tested the hypothesis that adhesion is increased by shear force in isolated setal arrays and live gecko toes. We also tested the corollary hypotheses that (1) adhesion in toes and arrays is limited as on the microscale by a critical angle, or (2)on the macroscale by adhesive strength as predicted for adhesive tapes. We found that adhesion depended directly on shear force, and was independent of detachment angle. Therefore we reject the hypothesis that gecko toes peel like tape. The linear relation between adhesion and shear force is consistent with a critical angle of release in live gecko toes and isolated setal arrays, and also with our prior observations of single setae. We introduced a new model,frictional adhesion, for gecko pad attachment and compared it to existing models of adhesive contacts. In an analysis of clinging stability of a gecko on an inclined plane each adhesive model predicted a different force control strategy. The frictional adhesion model provides an explanation for the very low detachment forces observed in climbing geckos that does not depend on toe peeling.
RNA editing level in the mouse is determined by the genomic repeat repertoire
Authors: Neeman Yossef , Levanon Erez Y. , Jantsch Michael F. , Eisenberg Eli 
Published: August 2006

A-to-I RNA editing is the conversion of adenosine to inosine in double-stranded cellular and viral RNAs. Recently, abundant editing of human transcripts affecting thousands of genes has been reported. Most editing sites are confined to the primate-specific Alu repeats. Notably, the editing level in mouse was shown to be much lower. In order to find the reason for this dramatic difference, here we identify editing sites within mouse repeats and analyze the sequence properties required for RNA editing. Our results show that the overall rate of RNA editing is determined by specific properties of different repeat families such as abundance, length, and divergence. We show that the striking difference in editing levels between human and mouse is mostly due to the higher divergence of the different mouse repeats.