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PubMed2000

The impact of parsimony weighting schemes on inferred relationships among toucans and neotropical barbets (Aves: piciformes).

The development of new schemes for weighting DNA sequence data for phylogenetic analysis continues to outpace the development of consensus on the most appropriate weights. The present study is an exploration of the similarities and differences between results from 22 character weighting schemes when applied to a study of barbet and toucan (traditional avian families Capitonidae and Ramphastidae) phylogenetic relationships. The dataset comprises cytochrome b sequences for representatives of all toucan and Neotropical barbet genera, as well as for several genera of Paleotropical barbets. The 22 weighting schemes produced conflicting patterns of relationship among taxa, often with conflicting patterns each receiving strong bootstrap support. Use of multiple weighting schemes helped to identify the source within the dataset (codon position, transitions, transversions) of the various putative phylogenetic signals. Importantly, some phylogenetic hypotheses were consistently supported despite the wide range of weights employed. The use of phylogenetic frameworks to summarize the results of these multiple analyses proved very informative. Relationships among barbets and toucans inferred from these data support the paraphyly of the traditional Capitonidae. Additionally, these data support paraphyly of Neotropical barbets, but rather than indicating a relationship between Semnornis and toucans, as previously suggested by morphological data, most analyses indicate a basal position of Semnornis within the Neotropical radiation. The cytochrome b data also allow inference of relationships among toucans. Supported hypotheses include Ramphastos as the sister to all other toucans, a close relationship of Baillonius and Pteroglossus with these two genera as the sister group to an (Andigena, Selenidera) clade, and the latter four genera as a sister group to Aulacorhynchus.

Animals↗
PubMed2000

Social relationships and cardiovascular disease risk factors: findings from the third national health and nutrition examination survey.

Objective. Our aim was to study the associations between social relationships and several health behaviors in a national sample of the U.S. population. Methods. Using data from National Health and Nutrition Examination Survey III, which was conducted from 1988 to 1994, we examined the associations between the frequencies of organizational and individual relationships (derived from factor analysis) and cigarette smoking, not having had a blood pressure check during the preceding 12 months, not having had a cholesterol check, not engaging in physical activity, and eating fruits and vegetables fewer than five times per day among men and women aged 18 years and older. Results. After adjusting for age, sex, race, educational attainment, marital status, and employment status, increases in organizational relationships were associated with decreases in all five behaviors: significant inverse linear trends were noted only for smoking and physical activity. For individual relationships, significant inverse linear trends were noted for not having a blood pressure check within the previous 12 months, not having had a cholesterol check, and inadequate fruit and vegetable consumption. For physical inactivity, the shape of the relationship approximated a threshold response. For smoking, a significant positive linear trend was present. Conclusions. These results support findings from previous studies and indicate that social relationships have a beneficial effect on several behaviors that directly or indirectly affect the risk of cardiovascular disease.

Adolescent↗
PubMed1991

Relationship of airborne endotoxin and bacteria levels in pig farms with the lung function and respiratory symptoms of farmers.

Previous studies have demonstrated a high prevalence of respiratory and other symptoms and a decrement in lung function among pig farm workers, although the relationships with specific agents present in the work environment remain obscure. This study was therefore undertaken to investigate the relationship between symptoms, lung function and airborne endotoxin, ammonia and dust levels in piggeries. Information on symptoms, lung function, endotoxin, ammonia and dust levels was available for 183 pig farmers who worked in 136 farms. For 62 farms information was present on the levels of bacteria and gram-negative bacteria. For these 62 farms, endotoxin exposure measurements were taken in more than one stable. In general, no significant correlations were found between lung function and chronic respiratory symptoms, or dust and ammonia levels. The endotoxin concentration in stables was negatively related to most lung function variables, but only for the subgroup of 62 farmers was a statistically significant relationship found between endoxtoxin exposure and FEV1. A borderline statistically significant and negative relationship was found between the endotoxin concentration and the FVC. Symptoms experienced during or shortly after work showed odds ratios larger than one with the levels of bacteria, gram-negative bacteria and endotoxin, indicating a positive relationship. No consistency in the relationship between symptoms and dust levels was found. The results suggest that endotoxins and (gram-negative) bacteria probably play an important role in the development of symptoms and lung function changes among pig farmers.

Adolescent↗
PubMed1993

Social relationships and health-related behavior.

The relationship of social ties to health behavior is studied in this paper. The general hypothesis tested is that those with social relationships are more likely to avoid health damaging behavior. Patterns regarding specific social ties and particular health behaviors are examined. Findings indicate the relationships of spouse, organization member, and friend are related to preventive health behavior; spouses are less likely smokers, drinkers, and heavy drinkers. The friend relationship is related to decreased smoking behavior, while the employee relationship is related to increased drinking. A consistent predictor of health behaviors is the social tie of organization member. People with relationships as organization members are more likely always to wear seat belts, smoke and drink less, and consume lower amounts of these substances.

Adult↗
PubMed1995

Unconventional sexual relationships: data about German women ages 50 to 91 years.

For older women there is a shortage of single male partners in the same age group. This study investigates the extent of relevant alternative sexual options. 91 German women aged 50 to 91 years (birth cohorts: 1895-1936) were interviewed about their attitudes to and experiences with unconventional sexual relationships (cumulative incidence figures are given in parentheses): At the time of interview 4% (18%) of the interviewees had a relationship with a man younger than themselves and 1% (4%) had a lesbian relationship. Of those living as singles, 8% were having an affair with a married man (21% had one while living as a single). Although relationships with married men occurred most often, attitudes towards relationships with married men were mostly negative. Feelings about relationships with younger men and other women were ambivalent.

Age Factors↗
PubMed1986

A new approach to defining regional work of the ventricle and evaluating regional cardiac function: mean wall stress-natural logarithm of reciprocal of wall thickness relationship.

A new method of defining regional mechanical work done by a unit volume of myocardium of the ventricular wall and evaluating regional cardiac function is proposed. This method uses the relationship between mean wall stress (sigma) and the natural logarithm of the reciprocal of wall thickness (ln(1/H)). 1/H at a point on the epicardial surface is proportional to the regional area (A) of the ventricular wall containing that point. The value for regional work obtained from the relationship between the sigma and ln A or sigma and ln(1/H) has a true dimension of work, i.e., [J/m3]. The sigma-ln(1/H) relationship was studied in ten anesthetized dogs. Wall thickness and internal diameter of the left ventricle were measured with ultrasonic dimension gauges. Regional work per unit volume of myocardium multiplied by the total myocardial volume of the left ventricle correlated well with the total mechanical work of the entire left ventricle calculated from the pressure-volume relationship during pressure loading, contractility change, and volume loading. During pressure loading, the end-systolic sigma-ln(1/H) relationship showed linearity. After bolus injection of isoproterenol the sigma-ln(1/H) loop shifted to the left. We concluded that the sigma-ln(1/H) relationship provides a method of characterizing regional function normalized to the unit volume of myocardium. In addition, our methods have a potential for echocardiographic application.

Animals↗
PubMed1996

Phylogenetic relationships of annelids, molluscs, and arthropods evidenced from molecules and morphology.

Annelids and arthropods have long been considered each other's closest relatives, as evidenced by similarities in their segmented body plans. An alternative view, more recently advocated by investigators who have examined partial 18S ribosomal RNA data, proposes that annelids, molluscs, and certain other minor phyla with trochophore larva stages share a more recent common ancestor with one another than any do with arthropods. The two hypotheses are mutually exclusive in explaining spiralian relationships. Cladistic analysis of morphological data does not reveal phylogentic relationships among major spiralian taxa but does suggest monophyly for both the annelids and molluscs. Distance and maximum-likelihood analyses of 18S rRNA gene sequences from major spiralian taxa suggest a sister relationship between annelids and molluscs and provide a clear resolution within the major groups of the spiralians. The parsimonious tree based on molecular data, however, indicates a sister relationship of the Annelida and Bivalvia, and an earlier divergence of the Gastropoda than the Annelida-Bivalvia clade. To test further hypotheses on the phylogenetic relationships among annelids, molluscs, and arthropods, and the ingroup relationships within the major spiralian taxa, we combine the molecular and morphological data sets and subject the combined data matrix to parsimony analysis. The resulting tree suggests that the molluscs and annelids form a monophyletic lineage and unites the molluscan taxa to a monophyletic group. Therefore, the result supports the Eutrochozoa hypothesis and the monophyly of molluscs, and indicates early acquisition of segmented body plans in arthropods.

Animals↗
PubMed2004

Relationships of body mass index with blood pressure and serum cholesterol concentrations at different ages.

BACKGROUND AND AIMS: Only limited information has been available on the effects of age on the relationship between obesity and other atherosclerotic risk factors, such as blood pressure and serum lipids. The purpose of this study was to investigate the effects of age on the relationships of obesity with blood pressure and serum cholesterol concentrations. METHODS: A community-based cross-sectional study was performed on 157,902 workers in Yamagata, Japan. Blood pressure and serum total and HDL cholesterol concentrations were measured, and body mass index (BMI) and atherogenic index were calculated. The correlations of BMI with blood pressure, serum cholesterol concentrations and atherogenic index in different age groups were compared. RESULTS: BMI showed significant positive correlations with systolic and diastolic blood pressures, serum total cholesterol level and atherogenic index, and showed a significant negative correlation with serum HDL cholesterol level. The relationships of BMI with systolic and diastolic blood pressures became weaker with advancing age in both men and women after 30 and 40 years of age, respectively. The relationships of BMI with serum total cholesterol level and atherogenic index also became weaker with advancing age after 30 years of age in men and after 40 years of age in women. There was no age-dependent tendency in the relationship between BMI and HDL cholesterol, however. The above age-dependent changes were more prominent in men than in women. CONCLUSION: The relationships of obesity with blood pressure, serum total cholesterol level and atherogenic index in the elderly are much weaker than in the young.

Adult↗
PubMed2003

Genetic relationships among perennial and annual Cicer species growing in Turkey assessed by AFLP fingerprinting.

AFLP markers were used to assess genetic relationships among Cicer species with distribution in Turkey. Genetic distances were computed among 47 Cicer accessions representing four perennial and six annual species including chickpea, using 306 positions on AFLP gels. AFLP-based grouping of species revealed two clusters, one of which includes three perennial species, Cicer montbretii, Cicer isauricum and Cicer anatolicum, while the other cluster consists of two subclusters, one including one perennial, Cicer incisum, along with three annuals from the second crossability group ( Cicer pinnatifidum, Cicer judaicum and Cicer bijugum) and the other one comprising three annuals from the first crossability group ( Cicer echinospermum, Cicer reticulatum and Cicer arietinum). Consistent with previous relationship studies in the same accession set using allozyme and RAPD markers, in AFLP-based relationships, C. incisum was the closest perennial to nearly all annuals, and C. reticulatum was the closest wild species to C. arietinum. Cluster analysis revealed the grouping of all accessions into their distinct species-clusters except for C. reticulatum accessions, ILWC247, ILWC242 and TR54961; the former was found to be closer to the C. arietinum accessions while the latter two clustered with the C. echinospermum group. Small genetic distance values were detected among C. reticulatum accessions (0.282) and between C. reticulatum and C. arietinum (0.301) indicating a close genetic similarity between these two species. Overall, the AFLP-based genetic relationships among accessions and species were congruous with our previous study of genetic relationships using allozymes. The computed level of AFLP variation and its distribution into within and between Cicer species paralleled the previous report based on RAPD analyses. AFLP analysis also confirmed the presence of the closest wild relatives and previous projections of the origin of chickpea in southern Turkey. Results presented in this report indicate that AFLP analysis is an efficient and reliable marker technology in determination of genetic variation and relationships in the genus Cicer. Obviously, the use of AFLP fingerprinting in constructing a detailed genetic map of chickpea and cloning, and characterizing economically important traits would be promising as well.

Cicer↗
PubMed2001

Theoretical frameworks for understanding and investigating the therapeutic relationship in psychiatry.

BACKGROUND: Mental health care is delivered through a relationship between a clinician and a patient. Although this therapeutic relationship is of central importance for mental health care, it appears to be relatively neglected in psychiatric research. Empirical research has for the most part adopted concepts and methods developed in psychotherapy and general medical practice. Hence, unpacking the presuppositions that have informed research on the therapeutic relationship to date may be a useful first step in developing this field. METHOD: A review of the literature was carried out. RESULTS: Six central theories are identified as framing the definitions and methods on this topic: role theory, psychoanalysis, social constructionism, systems theory, social psychology and cognitive behaviourism. To date, role theory, psychoanalysis and systems theory appear to be the frameworks most often applied in research in this field. Each perspective offers a unique emphasis in the analysis of the therapeutic relationship, which is reflected in the empirical work from each perspective discussed herein. CONCLUSIONS: None of the theories identified have been fully specified and comprehensively investigated in psychiatric settings. However, more than one approach may be used for thinking about relationships, depending on the treatment situation. Further specification and testing of the theories in psychiatric practice--taking account of the specific context--is warranted to underpin more pragmatic research. A stronger link between fundamental psychological and sociological research and applied health care research would advance our understanding of which elements of positive therapeutic relationships are instrumental in improving patient outcome and ultimately contribute to improving mental health care.

Humans↗
PubMed2002

Relationship between the curvature constant parameter of the power-duration curve and muscle cross-sectional area of the thigh for cycle ergometry in humans.

For high-intensity cycle ergometer exercise, the relationship between power output ( P) and its tolerable duration ( t) has been well characterized by the hyperbolic relationship: ( P- theta;(F)). t=W', where theta;(F) has been termed the "critical power" or "fatigue threshold". The curvature constant (W') reflects a constant amount of work which can be performed above theta;(F), and it may be regarded as a muscle energy store. The relationship of this energy store to muscle mass is not known. Therefore, the purpose of this study was to determine the relationships among W', accumulated peak oxygen deficit (accumulated peak O(2)-deficit), and muscle cross-sectional area (CSA) of the thigh for high-intensity cycle ergometry in humans. A group of 17 healthy male subjects (aged 21-41 years) participated in this study. The theta;(F) and W' of the P- t hyperbolic relationship and the accumulated peak O(2)-deficit was calculated by standard procedures. The CSA of muscle, fat and bone in the right thigh were measured using ultrasonography. The mean (SD) of theta;(F), W', accumulated peak O(2)-deficit, and muscle CSA of the thigh were 200.0 (17.8) W, 12.60 (2.94) kJ, 2.29 (0.41) l, and 185.3 (22.6) cm(2), respectively. The muscle CSA of the thigh was positively correlated with W' ( r=0.59, P<0.01) and with accumulated peak O(2)-deficit ( r=0.54, P<0.05). The relationship between W' and accumulated peak O(2)-deficit also showed a positive correlation ( r=0.63, P<0.005). Our results indicated that W' derived from the P- t hyperbolic curve as anaerobic working capacity is related to the CSA of muscle.

Adult↗
PubMed2004

Relationship between stress hormones and testosterone with prolonged endurance exercise.

Previous pharmacological and pathological studies have reported negative relationships between circulating testosterone and certain stress hormones (i.e., cortisol and prolactin) in humans. These relationships have subsequently been used in hypotheses explaining the subclinical resting testosterone levels often found in some endurance-trained males, but as of yet no one has specifically examined these relationships as they relate to exercise. Thus, we examined the relationship between total and free testosterone levels and cortisol, and between total and free testosterone and prolactin following prolonged endurance exercise in trained males. Twenty-two endurance-trained males volunteered to run at 100% of their ventilatory threshold (VT) on a treadmill until volitional fatigue. Blood samples were taken at pre-exercise baseline (B0); volitional fatigue (F0); 30 min (F30), 60 min (F60), and 90 min (F90) into recovery; and at 24 h post-baseline (P24 h). At F0 [mean running time = 84.8 (3.8) min], exercise induced significant changes (P<0.05) from B0 in total testosterone, cortisol and prolactin. All three of these hormones were still significantly elevated at F30; but at F60 only cortisol and prolactin were greater than their respective B0 values. Free testosterone displayed no significant changes from B0 at F0, F30, or the F60 time point. At F90, neither cortisol nor prolactin was significantly different from their B0 values, but total and free testosterone were reduced significantly from B0. Cortisol, total testosterone and free testosterone at P24 h were significantly lower than their respective B0 levels. Negative relationships existed between peak cortisol response (at time F30) versus total testosterone (at F90, r=-0.53, P<0.05; and at P24 h, r=-0.60, P<0.01). There were no significant relationships between prolactin and total or free testosterone. In conclusion, the present findings give credence to the hypothesis suggesting a linkage between the low resting testosterone found in endurance-trained runners and stress hormones, with respect to cortisol.

Adult↗
PubMed1997

Torque-velocity relationship during cycle ergometer sprints with and without toe clips.

The torque-velocity relationship in cycling has been studied during all-out sprints (n = 6 subjects) with and without toe clips on an electronic Lode ergometer with strain gauges, to estimate the importance of the expected decrease in torque, velocity and power output. As previously found with different cycling protocols, the torque-velocity relationship was linear for all-out sprints with toe clips. A similar relationship was observed when cycling without toe clips but the torque-velocity relationship was inflected downwards at low or high velocities in several subjects who were not regular cyclists. The pulling action during the rise of the pedal at low velocities cannot explain why the torque-velocity relationship is not hyperbolic for cycling exercises with toe clips because similar relationships were observed without toe clips. The maximal power output was significantly higher during cycling with toe clips (782 W vs 668 W, P < 0.05), probably because of the pulling action at low and medium velocities as indicated by the higher value of the extrapolated maximal torque T0 (138 N x m vs 122 N x m, P < 0.05). In contrast, the maximal extrapolated velocity, V0 and peak velocity were not significantly improved by the use of toe clips. The comparison of the angle-torque patterns at low and high velocities suggested that the kinetic energy of the legs can be transformed into power output when cycling without toe clips as well as it can when cycling with toe clips.

Adult↗
PubMed1999

Relationships between muscle mitochondrial DNA content, mitochondrial enzyme activity and oxidative capacity in man: alterations with disease.

Muscle mitochondrial content is tightly regulated, and requires the expression of both nuclear and mitochondrial genes. In addition, muscle mitochondrial content is a major determinant of aerobic exercise capacity in healthy subjects. The current study was designed to test the hypothesis that in healthy humans, muscle mitochondrial DNA (mtDNA) content is correlated with citrate synthase activity (a representative nuclear-encoded mitochondrial enzyme) and aerobic exercise capacity as defined by whole-body peak oxygen consumption (VO2). Furthermore, it was postulated that these relationships might be altered with disease. Twelve healthy and five paraplegic subjects underwent exercise testing and vastus lateralis muscle biopsy sampling. An additional ten healthy subjects and eight patients with unilateral peripheral arterial disease (PAD) underwent exercise testing and gastrocnemius muscle biopsy sampling. Citrate synthase activity and mtDNA content were positively correlated in the vastus lateralis muscles from the healthy subjects. This relationship was similar in muscle from paraplegic subjects. mtDNA content was positively correlated with peak VO2 in the healthy subjects and in the paraplegic subjects in whom peak VO2 had been elicited by functional electrical stimulation of the muscle. In contrast, the PAD subjects demonstrated higher mtDNA contents than would have been predicted based on their claudication-limited peak VO2. Thus, in healthy humans there are strong relationships between muscle mtDNA content and both muscle citrate synthase activity and peak VO2. These relationships are consistent with coordinant nuclear DNA and mtDNA expression, and with mitochondrial content being a determinant of aerobic exercise capacity. The relationships seen in healthy humans are quantitatively similar in paraplegic patients, but not in patients with PAD, a disease which is associated with a metabolic myopathy. The relationships between mtDNA content, mitochondrial enzyme activities and exercise capacity provide insight into the physiologic and pathophysiologic regulation of muscle mitochondrial expression.

Adolescent↗
PubMed1997

The effect of sarcoplasmic reticulum blockade on the force/frequency relationship and systolic contraction patterns in the newborn pig heart.

We investigated the relationship between heart rate and contractility in seven anaesthetized young piglets by measuring contractility at different atrial pacing rates. To study the origin of this relationship we repeated the measurements after blocking the sarcoplasmic reticulum calcium release channel with ryanodine. We assessed contractility using indices derived from instantaneous left ventricular pressure and volume measured by micromanometric and conductance catheters during rapid inferior vena cava occlusion, thus generating the end-systolic pressure-volume relationship, which was characterized by its slope Ees, and the maximum rate of change of ventricular pressure (dP/dtmax)/end-diastolic volume relationship, also characterized by its slope. All animals showed an increase in contractility with increasing heart rate (intact force/frequency relationship) which was abolished after ryanodine. The most striking effect of ryanodine on baseline haemodynamics was the dramatic decrease of dP/dtmax to about 50% of its original value, while peak developed pressure and Ees did not change. We conclude that the young piglet, despite its immaturity, has a functional sarcoplasmic reticulum, illustrated by an intact force/frequency relationship. In addition, blockade of the sarcoplasmic reticulum in vivo has profoundly different effects during early and late systole, indicating that indices of contractility derived during different parts of the cardiac cycle represent different aspects of systole.

Animals↗
PubMed2003

The contribution of small individuals to density-body size relationships.

The relationship between density and body size is central to our understanding of species assemblages. The greatest challenge in sampling complete assemblages is obtaining reliable estimates of all taxa regardless of body size. We therefore examined the density-body size relationship in a coral reef fish assemblage using a novel sampling method which permits reliable quantification of the small/cryptic reef fish fauna. We found a negative linear relationship between density and adult body size. This is in marked contrast to the polygonal relationship previously described for other local scale assemblage studies. Our linear relationship may be a consequence of the larger differences in body size among taxa. Spanning over five orders of magnitude, the range of body sizes appears to be an important factor in shaping density-body size relationships.

Animals↗
PubMed2004

The contribution of small individuals to density-body size relationships: examination of energetic equivalence in reef fishes.

A key relationship in ecology is that between density and body size, with the emphasis placed on energetic rules constraining the abundance of larger organisms below that of smaller organisms. Most studies have focused upon the density-body size relationship at the species level. However, energy is gathered at an individual level. We therefore examined this relationship in a coral reef fish assemblage, focusing on individuals. Using a comprehensive data set, with over 14,000 observations we found that the relationship between local density and adult body size differs from the linear relationship predicted by the 'energetic equivalence rule'. However, excluding the smallest size classes, the relationship between body size and individual abundance for intermediate to larger fish did not depart from the predicted -0.75. Unlike plants and intermediate to large reef fishes, the smallest fishes appear to have constraints that may reflect different patterns of resource acquisition.

Animals↗
PubMed2004

Grooming relationships of adolescent orphans in a free-ranging group of Japanese macaques (Macaca fuscata) at Katsuyama: a comparison among orphans with sisters, orphans without sisters, and females with a surviving mother.

The present study examined grooming relationships of adolescent females in a free-ranging group of Japanese macaques (Macaca fuscata) at Katsuyama. To assess whether the loss of the mother influenced the grooming relationships of adolescent females (5-7 years old), we compared the time spent in grooming interactions and the number of grooming partners among the following three groups: 6 adolescent orphans with sisters, 9 adolescent orphans without sisters, and 11 adolescent non-orphans with surviving mothers. In Japanese macaques, grooming most frequently occurs between mothers and their daughters. Therefore, it is expected that if the mother is lost, orphans will devote less time to grooming interactions than non-orphans. However, the time spent in overall grooming interactions did not differ among the three groups. While non-orphans maintained grooming relationships with their mothers, orphans acquired alternative grooming relationships with other group members. Orphans adopted two kinds of tactics to compensate for the loss of the mother. First, adolescent orphans with sisters developed more affiliative grooming relationships with their sisters than non-orphans with sisters. Secondly, adolescent orphans without sisters spent more time in grooming interactions with same-aged females and non-related adult females. Moreover, regarding grooming interactions with same-aged females and non-related adult females, orphans without sisters had a larger number of grooming partners than non-orphans. These results indicate that adolescent females have enough flexibility to develop their grooming network after the loss of their mothers, and that the lack of mother and sisters might accelerate socialization of adolescent females and enable them to be integrated in reciprocal adult grooming relationships.

Age Factors↗