bluuebunny/crossref_metadata_2025 huggingface dataset:
Glucose‐stimulated prehepatic insulin secretion is associated with circulating alanine, triglyceride, glucagon, lactate and TNF‐α in patients with HIV‐lipodystrophy
Authors: Haugaard SB , Andersen O , Pedersen SB , Dela F , Deacon CF , Holst JJ , Iversen J , Madsbad S
Published: February 2006

Objectives

We examined whether insulin‐resistant lipodystrophic HIV‐infected patients with known high fasting prehepatic insulin secretion rates (FISRs) displayed alterations in first‐phase prehepatic insulin response to intravenous glucose (ISREG0–10min).

Methods

Eighteen normoglycaemic lipodystrophic HIV‐infected (LIPO) patients and 25 normoglycaemic nonlipodystrophic HIV‐infected patients (controls) were included in the study. The prehepatic insulin secretion rate was estimated by deconvolution of C‐peptide concentrations, and insulin sensitivity (SIRd) was estimated by the glucose clamp technique. The disposition index (Di=ISREG0–10min× SIRd) was calculated to estimate the β‐cell response relative to insulin sensitivity.

Results

FISR was increased by 69% (P<0.001), whereas median Di was decreased by 75% (P<0.01), primarily as a result of a reduction of SIRd by 60% (P<0.001) in LIPO patients compared with controls. Three LIPO groups were identified arbitrarily according to their FISR and ISREG0–10min values relative to those of controls. Four LIPO patients displayed high FISR [+3 standard deviations (SD), P<0.001], high ISREG0–10min (+3SD, P<0.001) and low SIRd (P<0.01), suggesting an intact B‐cell capacity to compensate insulin resistance; six LIPO patients exhibited high FISR (+3SD, P<0.001), low ISREG0–10min (−1SD, P=0.01), and low SIRd (P<0.01), suggesting depletion of readily releasable insulin stores; the remaining eight LIPO patients and controls displayed identical FISR and ISREG0–10min. Increased concentrations of the nonglucose insulin secretagogues triglyceride (+124%), alanine (+35%) and glucagon (+88%), and also lactate (+96%) and tumour necrosis factor (TNF)‐α (+62%) were observed in the 10 LIPO patients with aberrations in FISR and ISREG0–10min compared with the remaining HIV‐infected patients (all P<0.05).

Conclusion

Plasma triglyceride, alanine, glucagon, lactate and TNF‐α may be associated with alterations in the first‐phase prehepatic insulin secretion response to intravenous glucose in normoglycaemic lipodystrophic HIV‐infected patients.
Effect of early and late GB virus C viraemia on survival of HIV‐infected individuals: a meta‐analysis
Authors: Zhang W , Chaloner K , Tillmann HL , Williams CF , Stapleton JT
Published: February 2006

Objectives

To conduct a meta‐analysis to synthesize the evidence regarding the effect of co‐infection with GB virus C (GBV‐C) on survival of HIV‐infected individuals, and to estimate the effect.

Methods

A Bayesian meta‐analysis was conducted to synthesize evidence from eligible studies. Prospective survival studies of HIV‐1‐infected individuals, with outcome defined as time from baseline to all‐cause death, were included and classified by whether GBV‐C status was determined in early or late HIV disease. The primary measure was the hazard ratio (HR) of death for HIV‐infected individuals with GBV‐C infection versus those without GBV‐C infection.

Results

Eleven studies from eight publications met the inclusion criteria. For studies with GBV‐C status measured 2 years or less after HIV seroconversion (912 subjects), the combined HR was 0.88 [95% credible interval (CI) 0.30, 1.50]. For studies with GBV‐C status measured more than 2 years after HIV seroconversion (1294 subjects), the combined HR was 0.41 (95% CI 0.23, 0.69).

Conclusions

No conclusive evidence was found of an association between survival and GBV‐C infection early in HIV disease. However, when GBV‐C infection was present later in HIV disease, a significant reduction in the hazard for mortality was observed for those with co‐infection. Potential explanations for this difference include a non‐proportional benefit of GBV‐C over time, possibly related to clearance of GBV‐C infection early in HIV disease. The timing of GBV‐C infection appears to account for the contradictory results of studies on the effect of GBV‐C coinfection on survival of HIV‐infected people.
Using knowledge within small and medium‐sized firms: A systematic review of the evidence
Authors: Thorpe Richard , Holt Robin , Macpherson Allan , Pittaway Luke
Published: February 2006

This paper provides a systematic review of the literature on how small and medium‐sized enterprises (SMEs) use and acquire knowledge. The review was undertaken as part of the Economic and Social Research Council's Evolution of Business Knowledge Programme. The paper describes the systematic review protocol and provides a detailed explanation of the methods used. From the review, it is evident that SME knowledge research concentrates primarily on the acquisition and use of knowledge, treating it as an asset that is transferred by routines. The findings suggest that research is focused in three main areas. First, on the influence and abilities of the entrepreneur to extract, use and develop knowledge resources. Secondly, on firm‐wide systems and the social capital that facilitates knowledge exploration and exploitation. Thirdly, on the provision of knowledge and learning experiences through government policy. From a practical perspective, the review concludes that policies encouraging entrepreneurship and economic regeneration need to be more flexible and sensitive to the often complex contexts within which knowledge is used by SMEs. From a research perspective, and given the flexible, opportunity‐oriented and often novel nature of SMEs identified in these studies, there is a need to consider the relational and embedded qualities of knowledge by which these characteristics are framed; qualities that resist conceptualization as some form of separable, material asset.
The genetic rescue of the Florida panther
Authors: Pimm S. L. , Dollar L. , Bass O. L.
Published: February 2006

We examine the consequences of panthers introduced from Texas into south Florida, an area housing a small, isolated, inbred and distinct subspecies (Puma concolor coryi). Once part of a continuous, widespread population, panthers became isolated in south Florida more than a century ago. Numbers declined and the occurrence of genetic defects increased. Hoping to reverse the genetic damage, managers introduced eight female panthers from Texas into south Florida in the mid‐1990s. This action was highly controversial and we explain the arguments for and against the intervention. We synthesized data systematically collected on the Florida panthers from before, during and after this management intervention. These data include information on movements, breeding, mortality, survivorship and range. There is no evidence that purebred Florida females produce fewer kittens at a later age or less often than do hybrid cats (i.e. those with a Texas ancestor). Hybrid kittens have about a three times higher chance of becoming adults as do purebred ones. Hybrid adult females survive better than purebred females; there is no obvious difference between the males. Males die younger than females, are more often killed by other males and are more likely to disperse longer distances into habitats that are dangerous to them. Hybrids are expanding the known range of habitats panthers occupy and use.
Impact of density‐dependent nest destruction on emergence success of Guianan leatherback turtles (Dermochelys coriacea)
Authors: Caut S. , Hulin V. , Girondot M.
Published: February 2006

To assess the impact of nest covering on a leatherback turtle Dermochelys coriacea nesting beach in French Guiana, we used field study data and a modelling approach. Field results showed that the covering of a pre‐existing nest by a new one causes the destruction of the older nest under some conditions of time and covering area, and almost always causes the destruction of the new nest. We then used field results to parameterize a theoretical model of the nesting beach. This allowed us to obtain a ‘critical carrying capacity for the beach’: the number of nests deposited for which the number of successful nests is maximum; when this number increases, the number of successful nests decreases. With these results, we then concluded that density‐dependent nest destruction plays a role in the functioning of the nesting beach. These results are essential for our understanding of nest‐site selection at the scale of the beach and its consequences.
Intergenerational effects of preterm birth and reduced intrauterine growth: a population‐based study of Swedish mother–offspring pairs
Authors: Selling KE , Carstensen J , Finnström O , Sydsjö G
Published: February 2006

Objective  To estimate the intergenerational effects of preterm birth and reduced intrauterine growth.

Design  Population‐based cohort study.

Settings  Mother–first‐born offspring pairs recorded in the Swedish Medical Birth Registry.

Population  Children born before 2001 to 38 720 women born in 1973–75.

Methods  The relationships between the mother's and the child's birth characteristics were estimated using logistic regression analysis. Adjustments were made for smoking habits, body mass index (BMI), and current and childhood socio‐economic conditions. Analyses were performed on all mother–offspring pairs and on the pairs for which information on neither of the included background variables was missing (n= 24 520).

Main outcome measures  Preterm birth (<37 weeks of gestation) and small for gestational age (SGA) (<−2 SD of the Swedish standard).

Results  Mothers who themselves had been born preterm were not significantly more likely to deliver their own children preterm, compared with those who had been born at term (adjusted OR 1.24, 95% CI 0.95–1.62). Also, preterm birth in the mothers did not influence the occurrence of SGA in the children. However, the odds ratio for giving birth to SGA and preterm children, respectively, was higher among SGA mothers (OR 2.68, 95% CI 2.11–3.41 and OR 1.30, 95% CI 1.05–1.61). Mothers whose intrauterine growth was moderately reduced but who did not meet the criterion of being born SGA were also at higher risk of giving birth to both preterm and SGA children, respectively.

Conclusions  The present study showed evidence of intergenerational effects of reduced intrauterine growth even when socio‐economic factors as well as BMI and smoking were adjusted for. There was, however, no consistent intergenerational effect of preterm birth.
Cisatracurium: myographical and electrophysiological studies in the isolated rat muscle
Authors: Serra C.S.M. , Oliveira A.C.
Published: February 2006

Myographical and electrophysiological studies of cisatracurium were performed, in vitro, in the isolated sciatic nerve‐extensor digitorum longus muscle preparation of the rat. Indirect twitches were generated at 0.1 Hz and tetanic contractions at 50 Hz. endplate potentials (epps) were generated in trains of 50 Hz. The electrophysiological variables used in the analysis of the epps were: amplitude of the first epp in the train, average amplitude of the 30° to the 59° epp in the train (epps‐plateau), tetanic rundown (percent loss in amplitude of epps‐plateau relative to the first epp in the train), quantal size and quantal content. The myographical results showed that the inhibitory concentration 50% (IC50) of cisatracurium for the blockade of twitches (0.48 μm) is 12 times its IC50for the induction of tetanic fade (0.04 μm). The electrophysiological results showed a concentration dependent decrease in the amplitudes of first epps in the trains and of epps‐plateau in the two used concentrations (0.13 μmand 0.38 μm). The tetanic rundown was intensified only in the presence of the higher (0.38 μm) concentration of cisatracurium. In cisatracurium 0.13 μm(a concentration which affects only tetanic contractions, inducing their fade, while leaving the twitch unaffected) there was a decrease in the quantal content of the first epp and of epps‐plateau in the train. In cisatracurium (0.38 μm), a concentration, which affects the twitch, there was a decrease of the quantal size and of quantal content of epps‐plateau, but not of the quantal content of the first epp in the train. The results indicate that the fade of the tetanic contraction induced by cisatracurium at the concentration of 0.13 μmis entirely because of a pre‐synaptic blocking effect while the decrease in the twitch induced by cisatracurium at the concentration of 0.38 μmis due to a post‐synaptic blocking effect.
Effect of inhaled corticosteroids on risk of development of cataract: a meta‐analysis
Authors: Uboweja Anup , Malhotra Samir , Pandhi P.
Published: February 2006

The objective of this study was to quantify the risk of cataract among users of inhaled corticosteroids (ICS). Studies that examined the association of ICS use with risk of cataract were identified through computerized (MEDLINE, EMBASE), manual searches using Index Medicus, and checking cross‐references to recover all published articles and scientific session abstracts. Pooled odds ratio (OR) with 95% confidence intervals (CI) were estimated using two methods, fixed effects Mantel–Haenszel model and random effects DerSimonian–Laird model. Four studies satisfied all the inclusion/exclusion criteria and were included in the analysis. The pooled OR (95% CI) by the Mantel–Haenszel method was 1.48 (1.39–1.57) and by the DerSimonian–Laird method was 1.48 (1.30–1.68). The test for heterogeneity was not significant. A total number of nine negative studies would be required to make the results of our meta‐analysis non‐significant. Number needed to harm is 16 with 95% CI of 13–19. Contrary to popular belief, inhaled ICS may be associated with systemic side effects like cataract as shown by this meta‐analysis. The risk of increased cataract shown in our analysis needs to be weighted against the benefits of ICS. Further evaluations are required to clarify the causal association between the dosage and duration of drug use.
Benzodiazepines prescription in Dakar: a study about prescribing habits and knowledge in general practitioners, neurologists and psychiatrists
Authors: Dièye Amadou Moctar , Sylla Mbaye , Ndiaye Awa , Ndiaye Mamadou , Guata Yoro Sy , Faye Babacar
Published: February 2006

Benzodiazepines are relatively well‐tolerated medicines but can induce serious problems of addiction and that is why their use is regulated. However, in developing countries like Senegal, these products are used without clear indications on their prescription, their dispensation or their use. This work focuses on the prescription of these medicines with a view to make recommendations for their rational use. Benzodiazepine prescription was studied with psychiatrists or neurologists and generalists in 2003. Specialist doctors work in two Dakar university hospitals and generalists in the 11 health centres in Dakar. We did a survey by direct interview with 29 of 35 specialists and 23 of 25 generalists. All doctors were interviewed in their office. The questionnaire focused on benzodiazepine indications, their pharmacological properties, benzodiazepines prescribed in first intention against a given disease and the level of training in benzodiazepines by doctors. Comparisons between specialists and generalists were made by chi‐square test. Benzodiazepines were essentially used for anxiety, insomnia and epilepsy. With these diseases, the most benzodiazepines prescribed are prazepam against anxiety and insomnia and diazepam against epilepsy. About 10% of doctors do not know that there is a limitation for the period of benzodiazepine use. The principal reasons of drugs choice are knowledge of the drugs, habit and low side effects of drugs. All generalists (100%) said that their training on benzodiazepines is poor vs. 62.1% of specialists, and doctors suggest seminars, journals adhesions and conferences to complete their training in this field. There are not many differences between specialists and generalists except the fact that specialists prefer prazepam in first intention in the insomnia treatment where generalists choose bromazepam. In addition, our survey showed that specialists’ training in benzodiazepines is better than that of generalists. Overall, benzodiazepine prescription poses problems particularly in training, and national authorities must take urgent measures for rational use of these drugs.
The effects of nocturnal home mechanical ventilation on daytime blood gas disturbances
Authors: Laub Michael , Midgren Bengt
Published: February 2006

Introduction:  In chronic alveolar hypoventilation, previous studies of selected patient groups have shown that nocturnal home mechanical ventilation (HMV) may result in improvements in chronic blood gas disturbances during daytime spontaneous breathing. We wished to examine the effects of this treatment in a large sample of non‐selected patients prospectively followed up, in a national multicentric register.

Material:  A total of 288 patients from a broad diagnostic spectrum were studied. We looked at the blood gases and vital capacity before the patients elected for initiation of HMV and at the first register‐recorded follow‐up after 6–24 months.

Results:  We found statistically significant improvements in PO2 and PCO2 (approximately 1 kPa in both) and in base excess, but no changes in vital capacity or calculated alveolo‐arterial gradient. All changes were independent of the observation period and only weakly diagnose‐related.

Discussion:  Our findings extend those of previous studies, showing a relatively early and apparently stable improvement in blood gases after starting and continuing nocturnal HMV. The equal extent of the improvements in blood gases among all the diagnostic groups including the neurological patients with progressive diseases was unexpected.

Conclusion:  In 288 patients starting nocturnal HMV electively we found significant improvements in daytime blood gases after 6–24 months. There were no changes in vital capacity or calculated alveolo‐arterial gradient.
Differences in heart rate variability in non‐hypertensive diabetic patients correlate with the presence of underlying cerebrovascular disease
Authors: Nagata Koji , Sasaki Eun , Goda Koshi , Yamamoto Naomune , Sugino Masakazu , Yamamoto Kazuhiro , Narabayashi Isamu , Hanafusa Toshiaki
Published: February 2006

We previously showed that diabetes contributes to the development of sclerotic lesions in cerebral arteries. In this study, we attempted to clarify whether differences in heart rate variability in non‐hypertensive diabetic patients were dependent on the presence or absence of underlying cerebrovascular disease. Thirty diabetic subjects between 40 and 59 years of age and who had no prior history of hypertension were used in this study. Lacunar lesions (LA) were detected with magnetic resonance imaging and atherosclerotic lesions (AS) were detected using intra‐ and extracranial magnetic resonance angiography, and by ultrasonographic scanning of the carotid artery. Patients underwent a full clinical laboratory screening and a power spectrum analysis of their heart rate variability. Subjects were divided into two groups: those with and without LA. The low frequency/high frequency ratio (LF/HF ratio) was found to be significantly increased (P<0·01) in subjects with LA (2·2 ± 0·3) compared to those without LA (1·3 ± 0·1). When subjects were divided into groups based on their presence or absence of AS, high‐frequency power was found to be significantly reduced (P<0·05) in the subjects with AS (12·8 ± 3·4 ms) compared to those without AS (19·4 ± 1·7 ms). The LF/HF ratio was found to be significantly increased (P<0·05) in the subjects with AS (2·2 ± 0·3) compared to those without AS (1·4 ± 0·1). Our data suggested that atherosclerotic lesions in cerebrovascular diseased linked to decrease of vagal nerve activity in non‐hypertensive diabetic patients.
The association between muscle EMG and perfusion in knee extensor muscles
Authors: Laaksonen Marko S. , Kyröläinen Heikki , Kalliokoski Kari K. , Nuutila Pirjo , Knuuti Juhani
Published: February 2006

The relationships between electromyographic (EMG) activity and force as well as muscle blood flow and work have been well established. However, the association between muscle blood flow and EMG activity remains unsolved. Thus, to test the hypothesis that muscle EMG activity relates to muscle perfusion in different compartments of the quadriceps femoris (QF) muscle, 12 healthy male subjects were studied. During two very submaximal exercise bouts, at different exercise intensities, oxygen labelled radiowater and positron emission tomography were used to measure muscle perfusion. In addition, produced force of knee extensors and muscle EMG activity in the vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) muscles were recorded during both exercise bouts. Although the exercise intensity and average force production was higher during the second exercise bout (38 ± 15 versus 51 ± 17 N; P = 0·007), the mean EMG activity was lower (RF; P<0·001) or unchanged (VL; P = 0·722 and VM; P = 0·640). During the second exercise period, perfusion also remained unchanged in the entire QF muscle (P = 0·223) and in its separate muscles (VL, P = 0·703; VM, P = 0·141; RF, P = 0·113) in a group level. However, the individual changes in muscle perfusion were tightly related to changes in muscle EMG activity in VL (r = 0·84; P = 0·002) and VM (r = 0·68; P = 0·015) but poorly in the RF muscle (r = 0·40; P = 0·257). In conclusion, the different associations between muscle perfusion and EMG activity in different QF muscles suggests specific functional role of the vasti muscles and the RF muscle.
Exercise test mode dependency for ventilatory efficiency in women but not men
Authors: Davis James A. , Tyminski Trisha A. , Soriano April C. , Dorado Silvia , Costello Kara B. , Sorrentino Kristin M. , Pham Patrick H.
Published: February 2006

Ventilatory efficiency is commonly defined as the level of ventilation V̇E at a given carbon dioxide output (V̇CO2). The slope of the V̇E versus V̇CO2 relationship and the lowest V̇E/V̇CO2 are two ventilatory efficiency indices that can be measured during cardiopulmonary exercise testing (CPET). A possible CPET mode dependency for these indices was evaluated in healthy men and women. Also evaluated was the relationship between these two indices as, in theory, V̇E/V̇CO2 falls hyperbolically towards an asymptote that numerically equals the V̇E versus V̇CO2 slope at exercise levels below the ones that cause respiratory compensation for metabolic acidosis. Twenty‐eight healthy subjects (14 men) underwent treadmill and cycle ergometer CPET on different days. Ventilation and the gas fractions for oxygen and CO2 were measured with a vacumed metabolic cart. In men, paired t‐test analysis failed to find a mode difference for either ventilatory efficiency index but the opposite was true in the women as each woman had higher values for both indices on the treadmill. For men, the lowest V̇E/V̇CO2 was larger than the V̇E versus V̇CO2 slope by 1·3 on the treadmill and 0·8 on the cycle ergometer. The corresponding values for women were 1·7 and 1·4. We conclude that in healthy subjects, women, but not men, demonstrate a mode dependency for the two ventilatory efficiency indices investigated in this study. Furthermore, our results are consistent with the theoretical expectation that the lowest V̇E/V̇CO2 has a numerical value just above the asymptote of the V̇E/V̇CO2 versus V̇CO2 relationship.
Reliability of different blood indices to explore the oxidative stress in response to maximal cycling and static exercises
Authors: Steinberg Jean Guillaume , Delliaux Stéphane , Jammes Yves
Published: February 2006

This study compares the changes in four blood markers of exercise‐induced oxidative stress in response to exercise protocols commonly used to explore the global muscle performance at work (maximal incremental cycle) and endurance to fatigue of selected muscles (static handgrip and thumb adduction). Cycling and static exercises allow the muscle to work in aerobic and anaerobic conditions, respectively. Healthy adults performed an incremental cycling exercise until volitional exhaustion and, on separated days, executed infra‐maximal static thumb adduction and handgrip until exhaustion. Exercise‐induced oxidative stress was assessed by the increased plasma concentration of thiobarbituric acid reactive substances (TBARS), the consumption of plasma reduced ascorbic acid (RAA), and erythrocyte reduced glutathione (GSH) antioxidants, and the changes in the total antioxidant status (TAS) of plasma. Five minutes after the end of the incremental cycling exercise, we measured a peak increase in TBARS level, maximal consumption of GSH and RAA, and a modest but significant decrease in TAS concentration. In response to both static thumb adduction and handgrip, significant variations of TBARS, GSH and RAA occurred but we did not measure any significant change in TAS level throughout the 20‐min recovery period of both exercise bouts. The present study shows that only the changes in TBARS, GSH and RAA explore both dynamic and static exercises. In addition, TAS measurement does not seem to represent a reliable and unique tool to explore exercise‐induced oxidative stress, at least during isometric efforts that allow the muscle to work under anaerobic condition.
Contrast media inhibit exogenous surfactant therapy in rats with acute respiratory distress syndrome
Authors: Kesecioglu Jozef , Haitsma Jack J. , Schultz Marcus J. , den Heeten Gerard J. , Lachmann Burkhard
Published: February 2006

Aim:  To test the effects of various contrast media on the pulmonary surfactant system.

Material and methods:  In a rat model of acute respiratory distress syndrome (ARDS) induced by lung lavage, the effects of surfactant suspended in saline were compared with surfactant suspended in the contrast media Visipaque®, Gastrografin®, Omnipaque®, Telebrix M®, Telebrix® and Hexabrix®, to establish their influence on oxygenation and lung mechanics.

Results:  After the induction of ARDS, surfactant instillation improved oxygenation, total lung capacity (TLC35), volume at 5 cm H2O end‐expiration (V5) and Gruenwald index. The effects of Visipaque® and Gastrografin® were comparable with those of surfactant alone from 90 min onwards and at 120 min, respectively. Surfactant suspended in the other contrast media resulted in significantly lower values in the above‐mentioned parameters. Surface tension was lowest in surfactant suspended in saline alone. Surfactant suspended in Visipaque® and Gastrografin® had lower surface tension compared with surfactant suspended in the other contrast media.

Conclusion:  The ionic and non‐ionic contrast media used in this study, cause an impairment of the physico‐chemical behaviour of exogenous surfactant. Therefore, these contrast media cannot be regarded as safe in case of accidental exposure.
Multiple pressure–volume loops recorded with sinusoidal low flow in a porcine acute respiratory distress syndrome model
Authors: Bitzén Ulrika , Enoksson Jens , Uttman Leif , Niklason Lisbet , Johansson Leif , Jonson Björn
Published: February 2006

Objectives:  To develop a method for automatic recording of multiple dynamic elastic pressure–volume (Pel/V) loops. To analyse the relationship between multiple dynamic Pel/V loops and static Pel/V loops in a porcine model of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). To test the hypothesis that increasing lung collapse and re‐expansion with decreasing positive end expiratory pressure (PEEP) can be characterized by hysteresis of the Pel/V loops.

Material and Interventions:  In eight anaesthetized and paralysed pigs, ALI/ARDS was induced by inhalation of dioctyl sodium sulfosuccinate and large tidal volume ventilation.

Measurements and Results:  The physiological and histopathological findings indicated a status mimicking an early stage of ALI/ARDS. Automatically, a series of dynamic Pel/V loops from different PEEP levels were recorded with the sinusoidal flow modulation method using a computer‐controlled ventilator. During expiration, resistance increased more than twofold. For each step of lower starting pressure, the inspiratory limb was displaced towards lower volume indicating derecruitment. Recruitment occurred between 20 and 40 cm H2O. The expiratory curves, all starting from 50 cm H2O, overlapped. Hysteresis increased significantly in loops recorded from lower PEEP levels. Viscoelasticity explained differences between static and dynamic Pel/V loops.

Conclusions:  Automated multiple Pel/V loop determination is feasible and provides comprehensive information on lung derecruitment and recruitment. It requires determination of volume dependence of expiratory resistance. An expiratory curve serves as a reference to inspiratory curves and provides information about hysteresis.
A lifetime of caring: Dimensions and dynamics in late‐life close relationships
Authors: BLIESZNER ROSEMARY
Published: February 2006

This review of research on close relationships in old age is informed by principles of life span developmental psychology and life course theory in sociology. It begins with an elaboration of life span and life course concepts as applied to relationships and an analysis of the multiple forms that caring can take. The discussion continues with presentation of research on the effects of sociohistorical contexts on relationships in old age and studies of the effects of personal development and life events on relationships as well. A section examining problems in late‐life close relationships is followed by examples of new directions for research on the intersections of personal development and close relationships.
Parental attachment and conflict behavior: Implications for offspring's attachment, loneliness, and relationship satisfaction
Authors: FEENEY JUDITH A.
Published: February 2006

This study assessed the implications of parental attachment security and parental conflict behavior for offspring's relational adjustment (attachment security, loneliness, and relationship satisfaction). Further, reports of parental conflict behavior were obtained from both parents and offspring, addressing questions regarding agreement between reporters and the origin and extent of discrepant perceptions. Results revealed consistent patterns of conflict behavior and moderate agreement between reporters. However, offspring reported parental conflict behavior more negatively than parents, especially when offspring or parents were anxious about relationships. Parental attachment security had direct associations with offspring's relationship anxiety, whereas associations between parental attachment and offspring's loneliness and discomfort with closeness were mediated by parental conflict behavior. Parental conflict behavior was also associated with offspring's relationship satisfaction. The results are discussed in terms of the mechanisms involved in the intergenerational transmission of relationship difficulties.
Friendships of Indonesian, South Korean, and U.S. college students
Authors: FRENCH DORAN C. , BAE ALYX , PIDADA SRI , LEE OKHWA
Published: February 2006

The friendships of college students in the United States (n= 61), Indonesia (n= 56), and South Korea (n= 35) were assessed to evaluate the H. C. Triandis, R. Bontempo, M. J. Villareal, M. Asai, and N. Lucca (1988) hypothesis that the friendships of individuals in collectivist cultures are more intimate and less extensive than those in individualistic cultures. Students rated the qualities of their friendships, reported the identity and characteristics of friends, and recorded details of their social interactions using the Rochester Interaction Inventory. The friendship characteristics of South Korean students were generally consistent with the H. C. Triandis et al. (1988) hypotheses, whereas those of the Indonesian students were not. It appears that friendships in some collectivist cultures, including Indonesia, display characteristics of extensive social contacts with others in conjunction with limited intimacy with specific individuals.
Gender, attachment, and relationship duration on cardiovascular reactivity to stress in a laboratory study of dating couples
Authors: KIM YOUNGMEE
Published: February 2006

Stress related to relationship events has been a strong predictor of cardiovascular reactivity. This four‐phase laboratory study used a multiple‐nested design to examine variations in diastolic blood pressure (DBP) and rate‐pressure product (RPP: pulse rate [PR] × systolic blood pressure [SBP]) as a function of stress appraisal using 33 college‐aged dating couples. Individual participants filled out questionnaires designed to assess the length of their relationships (couple‐level factor), gender and attachment styles (individual‐level factors); watched a film clip depicting relationship distress; discussed relationship problems; then received instruction for relaxation. Individuals’ self‐reported stress and negative affect levels (experimental phase‐level factors), DBP, SBP, and PR were also measured at each study phase. Hierarchical linear modeling analyses revealed that relationships with longer duration were associated with higher levels of DBP and RPP as perceived stress levels increased. Also, as perceived stress levels increased, men or individuals high in the anxiety dimension of attachment showed higher DBP and RPP reactivity, whereas individuals high in the avoidance dimension of attachment showed lower RPP reactivity. As the negative affect level increased, individuals high in the avoidance dimension of attachment showed lower RPP reactivity. Findings imply that under relationship stress, individuals high in avoidance or anxiety dimensions of attachment may be vulnerable to a range of physical symptoms, such as cardiovascular disease or hypertension.
Conservation Benefits of Temperate Marine Protected Areas: Variation among Fish Species
Authors: BLYTH‐SKYRME ROBERT E. , KAISER MICHEL J. , HIDDINK JAN G. , EDWARDS‐JONES GARETH , HART PAUL J. B.
Published: February 2006

Abstract:  Marine protected areas, and other fishery management systems that impart partial or total protection from fishing, are increasingly advocated as an essential management tool to ensure the sustainable use of marine resources. Beneficial effects for fish species are well documented for tropical and reef systems, but the effects of marine protected areas remain largely untested in temperate waters. We compared trends in sport‐fishing catches of nine fish species in an area influenced by a large (500‐km2) towed‐fishing‐gear restriction zone and in adjacent areas under conventional fishery management controls. Over the period 1973–2002 the mean reported weight of above‐average‐sized (trophy) fish of species with early age at maturity and limited home range was greatest within the area influenced by the fishing‐gear restriction zone. The reported weight of trophy fish of species that mature early also declined less and more slowly over time within the area influenced by the fishing‐gear restriction zone. Importantly, the mean reported weight of trophy fish of species that mature late and those that undertake extensive spatial movements declined at the same rate in all areas. Hence these species are likely to require protected areas >500 km2 for effective protection. Our results also indicated that fish species with a localized distribution or high site fidelity may require additional protection from sport fishing to prevent declines in the number or size of fish within the local population.
Using Niche‐Based Models to Improve the Sampling of Rare Species
Authors: GUISAN ANTOINE , BROENNIMANN OLIVIER , ENGLER ROBIN , VUST MATHIAS , YOCCOZ NIGEL G. , LEHMANN ANTHONY , ZIMMERMANN NIKLAUS E.
Published: February 2006

Abstract: Because data on rare species usually are sparse, it is important to have efficient ways to sample additional data. Traditional sampling approaches are of limited value for rare species because a very large proportion of randomly chosen sampling sites are unlikely to shelter the species. For these species, spatial predictions from niche‐based distribution models can be used to stratify the sampling and increase sampling efficiency. New data sampled are then used to improve the initial model. Applying this approach repeatedly is an adaptive process that may allow increasing the number of new occurrences found. We illustrate the approach with a case study of a rare and endangered plant species in Switzerland and a simulation experiment. Our field survey confirmed that the method helps in the discovery of new populations of the target species in remote areas where the predicted habitat suitability is high. In our simulations the model‐based approach provided a significant improvement (by a factor of 1.8 to 4 times, depending on the measure) over simple random sampling. In terms of cost this approach may save up to 70% of the time spent in the field.
Connectivity in an Agricultural Landscape as Reflected by Interpond Movements of a Freshwater Turtle
Authors: BOWNE DAVID R. , BOWERS MICHAEL A. , HINES JAMES E.
Published: February 2006

Abstract: Connectivity is a measure of how landscape features facilitate movement and thus is an important factor in species persistence in a fragmented landscape. The scarcity of empirical studies that directly quantify species movement and determine subsequent effects on population density have, however, limited the utility of connectivity measures in conservation planning. We undertook a 4‐year study to calculate connectivity based on observed movement rates and movement probabilities for five age‐sex classes of painted turtles (Chrysemys picta) inhabiting a pond complex in an agricultural landscape in northern Virginia (U.S.A.). We determined which variables influenced connectivity and the relationship between connectivity and subpopulation density. Interpatch distance and quality of habitat patches influenced connectivity but characteristics of the intervening matrix did not. Adult female turtles were more influenced by the habitat quality of recipient ponds than other age‐sex classes. The importance of connectivity on spatial population dynamics was most apparent during a drought. Population density and connectivity were low for one pond in a wet year but dramatically increased as other ponds dried. Connectivity is an important component of species persistence in a heterogeneous landscape and is strongly dependent on the movement behavior of the species. Connectivity may reflect active selection or avoidance of particular habitat patches. The influence of habitat quality on connectivity has often been ignored, but our findings highlight its importance. Conservation planners seeking to incorporate connectivity measures into reserve design should not ignore behavior in favor of purely structural estimates of connectivity.
Effects of Forest Fragmentation on Phenological Patterns and Reproductive Success of the Tropical Dry Forest Tree Ceiba aesculifolia
Authors: HERRERÍAS‐DIEGO YVONNE , QUESADA MAURICIO , STONER KATHRYN E. , LOBO JORGE A.
Published: February 2006

Abstract:  Spatial isolation caused by forest fragmentation and temporal isolation caused by asynchronous flowering of plants have been proposed as important factors that affect the reproduction of plant populations. In a 4‐year study, we determined the effects of forest fragmentation and spatial isolation on flowering phenology and reproductive success of the tropical tree Ceiba aesculifolia ([Kunth] Britton & Rose). We conducted our study in the dry forest of Mexico and compared populations in two habitat conditions based on density and environmental conditions: (1) disturbed habitat (four populations of ≤3 reproductive individuals/ha surrounded by agricultural fields or pastures) and (2) undisturbed habitat (three populations of groups of ≥6 reproductive individuals/ha surrounded by undisturbed mature forest). We compared the following variables within these populations over 4 years: flowering overlap, proportion of individuals with flowers and fruit, total flower production, total fruit production, fruit set, seed production, and seed abortion. Little overlap in flowering occurred among the populations in the two habitat conditions. The flowering period of trees in the disturbed habitat initiated between 15 to 20 days before the flowering period of trees in the undisturbed habitat during 3 years. Flowering of trees in the undisturbed habitat peaked at the end of the flowering period of the trees in the disturbed habitat. The proportion of trees that flowered was greater in the undisturbed habitat. Nevertheless, total flower production was greater in the disturbed habitat and these differences were maintained across 3 years. The proportion of individuals that produced fruit did not differ across habitat conditions but did differ across years. Total fruit production was greater in the disturbed habitat, but fruit set and seed production were the same across years and between habitat conditions. Seed abortion varied over years between habitats. We concluded that forest fragmentation does not negatively affect the reproductive success of C. aesculifolia. It appears that the highly mobile bat pollinators maintain reproductive connectivity between trees in both habitats.
A low diversity of ANTP class homeobox genes in Placozoa
Authors: Monteiro A.S. , Schierwater B. , Dellaporta S.L. , Holland P.W.H.
Published: February 2006

SUMMARYHomeobox genes of the ANTP and PRD classes play important roles in body patterning of metazoans, and a large diversity of these genes have been described in bilaterian animals and cnidarians.Trichoplax adhaerens(Phylum Placozoa) is a small multicellular marine animal with one of the simplest body organizations of all metazoans, showing no symmetry and a small number of distinct cell types. Only two ANTP class genes have been described fromTrichoplax: the Hox/ParaHox geneTrox‐2and a gene related to the Not family. Here we report an extensive screen for ANTP class genes inTrichoplax, leading to isolation of three additional ANTP class genes. These can be assigned to the Dlx, Mnx and Hmx gene families. Sequencing approximately 12–20 kb around each gene indicates that none are part of tight gene clusters, and in situ hybridization reveals that at least two have spatially restricted expression around the periphery of the animal. The low diversity of ANTP class genes isolated inTrichoplaxcan be reconciled with the low anatomical complexity of this animal, although the finding that these genes are assignable to recognized gene families is intriguing.
Evolution of larval form in ophiuroids: insights from the metamorphic phenotype of Ophiothrix (Echinodermata: Ophiuroidea)
Authors: Selvakumaraswamy Paulina , Byrne Maria
Published: February 2006

SUMMARY
Comparison of development through metamorphosis in Ophiothrix species provided insights into the evolutionary relationships between Type I (ophiopluteus only) and Type II (ophiopluteus and vitellaria) patterns of development in the Ophiuroidea. As typical of Type I developers, the six inner larval arms in Ophiothrix spongicola were fully resorbed at metamorphosis and no remnants of ciliated epithelia were retained. The postero‐lateral arms function as locomotory organs for the developing juvenile and were discarded at settlement. In contrast, in O. ciliaris the epithelia of the inner arms were transformed into ciliated ridges, similar to those seen in vitellariae and the postero‐lateral arms were resorbed rather than being discarded. Larval arm resorption in O. ciliaris is similar to that in Type II developers. The metamorphic phenotype of O. ciliaris provides a link between Type I and II development. The presence of two types of metamorphosis in congeneric ophiuroids and the variable metamorphic phenotype of O. ciliaris was unexpected. It appears that closely related ophiuroids and individual species may have the capacity to metamorphose using either Type I or Type II pathways. Although the phylogenetic distribution of metamorphic phenotypes indicates that Type II development may be the ancestral state, comparative morphology suggests that a developmental dichotomy based on larval arm resorption may not be appropriate for the Ophiuroidea. Until metamorphosis is characterized for more taxa, the ancestral developmental mode for the Ophiuroidea will remain a matter of conjecture.
Juvenile hormone mediates a trade‐off between primary and secondary sexual traits in stalk‐eyed flies
Authors: Fry Catherine L.
Published: February 2006

SUMMARY
Trade‐offs between developing body parts may contribute to variation in allometric scaling relationships in a variety of taxa. Experimental evidence indicates that both circulating levels of juvenile hormone (JH) and sensitivities of developing body parts to JH can influence morphology in polyphenic insects. However, the extent to which JH may regulate both the development of traits that scale continuously with body size and trade‐offs between these traits is largely unknown. Here, I present evidence that the JH analog methoprene applied to final instar larvae of a stalk‐eyed fly (Cyrtodiopsis dalmanni) can induce males to produce larger eye‐stalks relative to their body size. Examination of testis growth, sperm transfer, and egg maturation indicates that JH induces a trade‐off between eye‐span and gonad development in adult males, but not females. Age at sexual maturity was unaffected by larval JH applications to either sex. Collectively, these results are consistent with JH‐mediated allocation of resources to eye‐span at the expense of testes, and indicate potential costs for the production of an exaggerated trait.
From cells to colonies: at what levels of body organization does the ‘temperature‐size rule’ apply?
Authors: Atkinson David , Morley Simon A. , Hughes Roger N.
Published: February 2006

SUMMARY
An inverse relationship between temperature during ontogeny and final body size is widespread in ectotherms, but poorly understood. Evidence suggests that within organs, this “temperature‐size rule” (TSR) may also apply to cell size with no change in numbers. So how closely do reductions in size and number of cells and other repeated structures correlate with size reduction at higher levels of organization? We examine this in the context of a proposal that size and/or number changes at various organizational levels are adaptive responses to temperature‐ and size‐dependent oxygen supply. We subjected two clones of the modular colonial bryozoan, Celleporella hyalina, to orthogonal combinations of two temperatures and two oxygen concentrations during ontogeny, observing effects on sizes of colonies and larvae, and sizes and numbers of cells, tentacles, and modules (autozooids). We found that the size:number responses varied among cell types and among structures at different levels of organization, with the inverse temperature‐size relationship applying only to larval parenchymal cells and colony modules. Using our findings and other evidence we propose a unifying adaptive hypothesis that predicts how temperature affects the sizes of mitochondria, cells, organs, modules and organisms, and their relationships with processes that determine the functional capacity of aerobic metabolism.