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Comparative Data (comparative + data)
Selected AbstractsEase and effectiveness of costly autotomy vary with predation intensity among lizard populationsJOURNAL OF ZOOLOGY, Issue 3 2004William E. Cooper Jr Abstract Costly anti-predatory defences are used in ecological time and maintained in evolutionary time by natural selection favouring individuals that survive through their use. Autotomy of expendable body parts is a striking example of a defence having multiple substantial costs, including loss of ability to use the same defence, loss of energy, and decreased growth, reproductive success and survival following autotomy, plus the energetic cost of replacing the lost body part in species capable of regenerating them. Our study shows that autotomy in the lacertid lizard Podarcis lilfordi reduces sprint speed, indicating decreased capacity to escape as well as the loss of energy. Autotomy carries substantial cost, and thus should be avoided except as a last resort. Ease of autotomy and post-autotomic movements were studied in three populations of lacertid lizards. Two were islet populations of P. lilfordi from Aire (lowest predation pressure) and Colom (intermediate predation pressure) off Minorca. The third was a mainland population of Podarcis hispanica, a closely related species from the mainland of the Iberian Peninsula where predation pressure is higher than on the islets. As predicted, a suite of autotomic traits increases the effectiveness of autotomy as a defence as predation pressure increases. With increasing predation pressure, the frequency of voluntary autotomy increases, latency to autotomy decreases, pressure on the tail needed to induce autotomy decreases, vigour of post-autotomic tail movements increases, and distance moved by the shed tail increases. Additional changes that might be related to predation pressure, but could have other causes, are the presence of tail coloration contrasting with body coloration except under the lowest predation pressure (Aire) and longer tails in the mainland species P. hispanica. Correspondence between predation pressure and the suite of autotomic traits suggests that autotomy is an important defence that responds to natural selection. Comparative data are needed to establish the generality of relationships suggested in our study of only three populations. [source] Differences in the nearpoint of convergence with target typeOPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 5 2001John Siderov Summary Purpose: The purpose of this study was to determine the effect on measurements of the nearpoint of convergence (NPC) of different target types. In order to assess the influence of accommodation, the NPC was also measured under conditions of varying accommodative demand. Methods: The NPC was measured to the nearest 0.5 cm using three targets: the RAF rule, the sharpened tip of a pencil and the tip of the examiner's index finger. All measurements were performed under the same conditions on two groups of asymptomatic subjects, a group of 14 presbyopic subjects and a group of 14, younger, non-presbyopic subjects. The influence of accommodative demand was assessed in the non-presbyopic group by measuring the NPC while subjects viewed the RAF rule target through +2.00 and ,2.00 lenses held in front of their eyes. Results: For the presbyopic group, the NPC (break) and NPC (recovery) were independent of target type. However, the NPC (break) was significantly less remote than the NPC (recovery). Comparative data for the non-presbyopic group showed that NPC (break) for the RAF target was less remote than for either the pencil tip or finger tip targets. In agreement with the results from the presbyopic group, the NPC (recovery) was independent of target type. Conclusion: For subjects with little or no accommodation, the NPC does not depend on the target used and is the same measured with the RAF rule, a pencil tip or finger tip. In non-presbyopic subjects there appears to be a small accommodative influence on the NPC, which is target dependent. However, the difference is probably not clinically important. [source] Rationale and Design of the OPTION Study: Optimal Antitachycardia Therapy in ICD Patients without Pacing IndicationsPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2010CHRISTOF KOLB M.D. Background:,Implantable cardioverter-defibrillators (ICDs) represent the treatment of choice for primary and secondary prevention of sudden cardiac death but ICD therapy is also plagued by inappropriate shocks due to supraventricular tachyarrhythmias. Dual-chamber (DC) ICDs are considered to exhibit an enhanced discrimination performance in comparison to single-chamber (SC) ICDs, which results in reduction of inappropriate detections in a short- to mid-term follow-up. Comparative data on long-term follow-up and especially on inappropriate shocks are limited. Methods:,The aim of the OPTION study is to assess whether an optimized treatment with DC ICDs improves patient outcome and decreases the rate of inappropriate shocks in comparison to SC ICDs. DC ICD therapy optimization is achieved by optimal customizing of antitachycardia therapy parameters, activation of discrimination algorithms, antitachycardia pacing in the slow ventricular tachycardia zone, and avoidance of right ventricular pacing with the SafeR algorithm mode. The OPTION study, a prospective, multicenter, randomized, single-blinded, parallel study, will randomize 450 patients on a 1:1 allocation to either an SC arm with backup pacing at VVI 40 beats per minute (bpm) or to the DC arm with SafeR pacing at 60 bpm. Patients will be followed for 27 months. Primary outcome measure is the time to first occurrence of inappropriate shock and a combined endpoint of cardiovascular morbidity and all-cause mortality. Conclusion:,The study will evaluate the relative performance of DC in comparison to SC ICDs in terms of inappropriate shock reduction and patient outcome. (PACE 2010; 33:1141,1148) [source] Understanding hind limb weight support in chimpanzees with implications for the evolution of primate locomotionAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2009David A. Raichlen Abstract Most quadrupedal mammals support a larger amount of body weight on their forelimbs compared with their hind limbs during locomotion, whereas most primates support more of their body weight on their hind limbs. Increased hind limb weight support is generally interpreted as an adaptation that reduces stress on primates' highly mobile forelimb joints. Thus, increased hind limb weight support was likely vital for the evolution of primate arboreality. Despite its evolutionary importance, the mechanism used by primates to achieve this important kinetic pattern remains unclear. Here, we examine weight support patterns in a sample of chimpanzees (Pan troglodytes) to test the hypothesis that limb position, combined with whole body center of mass position (COM), explains increased hind limb weight support in this taxon. Chimpanzees have a COM midway between their shoulders and hips and walk with a relatively protracted hind limb and a relatively vertical forelimb, averaged over a step. Thus, the limb kinematics of chimpanzees brings their feet closer to the COM than their hands, generating greater hind limb weight support. Comparative data suggest that these same factors likely explain weight support patterns for a broader sample of primates. It remains unclear whether primates use these limb kinematics to increase hind limb weight support, or whether they are byproducts of other gait characteristics. The latter hypothesis raises the intriguing possibility that primate weight support patterns actually evolved as byproducts of other traits, or spandrels, rather than as adaptations to increase forelimb mobility. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source] Effects of cellulase and xylanase enzymes on the deconstruction of solids from pretreatment of poplar by leading technologiesBIOTECHNOLOGY PROGRESS, Issue 2 2009Rajeev Kumar Abstract Comparative data is presented on glucose and xylose release for enzymatic hydrolysis of solids produced by pretreatment of poplar wood by ammonia fiber expansion (AFEX), ammonia recycled percolation (ARP), controlled pH, dilute acid, flowthrough (FT), lime, and sulfur dioxide (SO2) technologies. Sugar solubilization was measured for times of up to 72 h using cellulase supplemented with ,-glucosidase at an activity ratio of 1:2, respectively, at combined protein mass loadings of 5.8,116 mg/g of glucan in poplar wood prior to pretreatment. In addition, the enzyme cocktail was augmented with up to 11.0 g of xylanase protein per gram of cellulase protein at combined cellulase and ,-glucosidase mass loadings of 14.5 and 29.0 mg protein (about 7.5 and 15 FPU, respectively)/g of original potential glucose to evaluate cellulase,xylanase interactions. All pretreated poplar solids required high protein loadings to realize good sugar yields via enzymatic hydrolysis, and performance tended to be better for low pH pretreatments by dilute sulfuric acid and sulfur dioxide, possibly due to higher xylose removal. Glucose release increased nearly linearly with residual xylose removal by enzymes for all pretreatments, xylanase leverage on glucan removal decreased at high cellulase loadings. Washing the solids improved digestion for all pretreatments and was particularly beneficial for controlled pH pretreatment. Furthermore, incubation of pretreated solids with BSA, Tween 20, or PEG6000 prior to adding enzymes enhanced yields, but the effectiveness of these additives varied with the type of pretreatment. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] Family functioning and juvenile chronic physical illness in Northern RussiaACTA PAEDIATRICA, Issue 2 2009A Zashikhina Abstract Aim: To study family functioning of adolescents with chronic physical illnesses and factors related to it. The following research questions were addressed: (i) if families with adolescents with chronic physical illnesses were at increased risk for problematic functioning compared to the healthy control families; (ii) was disease severity associated with family dysfunction; and (iii) did family functioning level differ in three disease groups (diabetes, asthma and epilepsy). Methods: Self-report family inventory and socio-economic status questions were individually completed by 148 adolescents with physical illnesses aged 13,16 years and their mothers; medical data were obtained from the files at the outpatient clinics. Comparative data were collected from a group of 301 schoolchildren. Results: Overall there were no differences found in functioning of families with physically ill adolescents compared to controls. Family functioning was significantly associated with the number of disease-specific (disease severity and duration) and non-disease (socio-economic status and family type) factors. Conclusion: In our study, families with physically ill adolescents showed considerable resilience and tolerance to the changes in habitual functioning of the family unit. While greater disease severity, longer disease duration, as well as single-parent household were the factors that contributed to the family dysfunction. [source] Racial Metaphors: Interpreting Sex and AIDS in AfricaDEVELOPMENT AND CHANGE, Issue 5 2003Eileen Stillwaggon Western preconceptions regarding African sexuality distorted early research on the social context of AIDS in Africa and limited the scope of preventive policies. Key works cited repeatedly in the social science and policy literature constructed a hypersexualized pan,African culture as the main reason for the high prevalence of HIV in sub,Saharan Africa. Africans were portrayed as the social ,Other' in works marked by sweeping generalizations and innuendo, rather than useful comparative data on sexual behaviour. Although biomedical studies demonstrate the role of numerous factors that influence HIV transmission among poor people, a narrowly behavioural explanation dominated the AIDS,in,Africa discourse for over a decade and still circumscribes preventive strategies in Africa and elsewhere. [source] Comparative growth in the postnatal skull of the extant North American turtle Pseudemys texana (Testudinoidea: Emydidae)ACTA ZOOLOGICA, Issue 2 2008Gabe S. Bever Abstract Bever, G.S. 2007. Comparative growth in the postnatal skull of the extant North American turtle Pseudemys texana (Testudinoidea: Emydidae). ,Acta Zoologica (Stockholm) 88: 000,000 Postnatal growth is one of the many aspects of developmental morphology that remains distinctly understudied in reptiles. Variation and ontogenetic scaling within the skull of the extant emydid turtle, Pseudemys texana is described based on 25 continuous characters. Results indicate that skull shape in this species changes little during postnatal growth relative to the only cryptodire taxa for which comparable datasets are available (Apalone ferox and Sternotherus odoratus). This relative lack of change results in the paedomorphic retention of a largely juvenile appearance in the adult form of P. texana. The skulls of males and females, despite the presence of distinct sexual dimorphism in size, grow with similar scaling patterns, and the few observed differences appear to reflect alteration of the male growth trajectory. Comparisons with A. ferox and S. odoratus reveal a number of similarities and differences that are here interpreted within a phylogenetic context. These preliminary hypotheses constitute predictive statements that phylogenetically bracket the majority of extant cryptodire species and provide baseline comparative data that are necessary for the future recognition of apomorphic transformations. Plasticity of ontogenetic scaling as a response to the homeostatic needs and behaviour of individuals commonly is evoked as a limitation of ontogenetic scaling as a means to inform phylogenetic studies. These evocations are largely unfounded considering that variability itself can evolve and thus be phylogenetically informative. [source] Virulence evolution via host exploitation and toxin production in spore-producing pathogensECOLOGY LETTERS, Issue 4 2002Troy Day Many pathogens produce resilient free-living propagules that allow their dissemination in the absence of direct contact between susceptible and infected hosts. One might expect pathogens capable of producing such long-lived propagules to evolve high levels of virulence because their reproductive success is de-coupled from the survival of their host. Despite some comparative data supporting this prediction, theory has questioned its general validity. I present theoretical results that incorporate two transmission routes neglected by previous theory: death-mediated propagule production and direct host-host transmission. This theory predicts that spore-producing pathogens should evolve high levels of virulence under quite broad conditions. Moreover, a novel prediction of this theory is that the production of propagules can generate selection for the evolution of pathogen characteristics such as toxins whose sole function is to kill the host. This latter result reveals an unanticipated mechanism through which virulence is expected to evolve in spore-producing pathogens. [source] Returns to Education in the European Union: a re-assessment from comparative dataEUROPEAN JOURNAL OF EDUCATION, Issue 1 2005GEORGES HEINRICH First page of article [source] Sleep disruption, daytime somnolence and ,sleep attacks' in Parkinson's disease: a clinical survey in PD patients and age-matched healthy volunteersEUROPEAN JOURNAL OF NEUROLOGY, Issue 3 2006J. J. Ferreira Recent case reports of ,sleep attacks' (SA) in patients with Parkinson's disease (PD) generated concerns about drug-induced daytime somnolence in this population. However, there are nearly no comparative data on sleep and vigilance problems between PD patients and normal controls. We performed a cross-sectional survey in PD patients and age-matched controls using a structured questionnaire on PD history, treatments, co-morbidity, activities of daily living, habits, exercise, sleep pattern, driving, pre-existing nocturnal problems, daytime somnolence, episodes of SA and the circumstances in which such episodes occurred. Daytime somnolence was also measured with the Epworth Sleepiness Scale (ESS) and sleep quality with the Pittsburgh Sleep Quality Index (PSQI). 176 PD patients and 174 controls were included. The same proportion of PD patients (27%) and controls (32%) reported episodes of SA, but these were more frequent in PD patients and occurred more frequently during situations requiring attention (10.8% vs. 1.7%, p<10,3). More PD patients had abnormal daytime somnolence (ESS) and poor sleeping quality (PSQI). The most consistent factor associated with SA was the duration of levodopa therapy and the predictive value of an abnormal ESS score was rather poor (40.7%). Abnormal daytime somnolence and poor sleep quality at night are more frequent in PD patients than in normals. However, SA are reported in both groups, although less frequently in the normals during activities that requires attention. [source] ADAPTIVE REPTILE COLOR VARIATION AND THE EVOLUTION OF THE MCIR GENEEVOLUTION, Issue 8 2004Erica Bree Rosenblum Abstract The wealth of information on the genetics of pigmentation and the clear fitness consequences of many pigmentation phenotypes provide an opportunity to study the molecular basis of an ecologically important trait. The melanocortin-1 receptor (Mc1r) is responsible for intraspecific color variation in mammals and birds. Here, we study the molecular evolution of Mc1r and investigate its role in adaptive intraspecific color differences in reptiles. We sequenced the complete Mc1r locus in seven phylogenetically diverse squamate species with melanic or blanched forms associated with different colored substrates or thermal environments. We found that patterns of amino acid substitution across different regions of the receptor are similar to the patterns seen in mammals, suggesting comparable levels of constraint and probably a conserved function for Mc1r in mammals and reptiles. We also found high levels of silent-site heterozygosity in all species, consistent with a high mutation rate or large long-term effective population size. Mc1r polymorphisms were strongly associated with color differences in Holbrookia maculata and Aspidoscelis inornata. In A. inornata, several observations suggest that Mc1r mutations may contribute to differences in color: (1) a strong association is observed between one Mc1r amino acid substitution and dorsal color; (2) no significant population structure was detected among individuals from these populations at the mitochondrial ND4 gene; (3) the distribution of allele frequencies at Mc1r deviates from neutral expectations; and (4) patterns of linkage disequilibrium at Mc1r are consistent with recent selection. This study provides comparative data on a nuclear gene in reptiles and highlights the utility of a candidate-gene approach for understanding the evolution of genes involved in vertebrate adaptation. [source] Short and long germ segmentation: unanswered questions in the evolution of a developmental modeEVOLUTION AND DEVELOPMENT, Issue 6 2005Paul Z. Liu Summary The insect body plan is very well conserved, yet the developmental mechanisms of segmentation are surprisingly varied. Less evolutionarily derived insects undergo short germ segmentation where only the anterior segments are specified before gastrulation whereas the remaining posterior segments are formed during a later secondary growth phase. In contrast, derived long germ insects such as Drosophila specify their entire bodies essentially simultaneously. These fundamental embryological differences imply potentially divergent molecular patterning events. Numerous studies have focused on comparing the expression and function of the homologs of Drosophila segmentation genes between Drosophila and different short and long germ insects. Here we review these comparative data with special emphasis on understanding how short germ insects generate segments and how this ancestral mechanism may have been modified in derived long germ insects such as Drosophila. We break down the larger issue of short versus long germ segmentation into its component developmental problems and structure our discussion in order to highlight the unanswered questions in the evolution of insect segmentation. [source] Ancestors and variants: tales from the crypticEVOLUTION AND DEVELOPMENT, Issue 3 2000William E. Browne SUMMARY Those who work at the interface of development and evolution are united by the conviction that developmental comparisons can shed light on both the evolution of specific morphologies and the macroevolutionary process itself. In practice, however, the field comprises a diversity of approaches. As the field grows and practitioners attempt to digest a growing mountain of comparative data, the various approaches of "Evo Devo" have themselves evolved. A meeting organized by the authors and held at the University of Chicago in the Spring of 1999 illustrated some of these changes. This review will draw on its content to discuss recent developments in two areas: the reconstruction of common ancestors and the developmental basis of evolutionary change. [source] A comparative study of the dispersal of 10 species of stream invertebratesFRESHWATER BIOLOGY, Issue 9 2003J. M. Elliott Summary 1. Apart from downstream dispersal through invertebrate drift, few quantitative data are available to model the dispersal of stream invertebrates, i.e. the outward spreading of animals from their point of origin or release. The present study provides comparative data for 10 species, using two independent methods: unmarked animals in six stream channels built over a stony stream and marked animals in the natural stream. Experiments were performed in April and June 1973 and 1974, with initial numbers of each species varying from 20 to 80 in the stream channels and 20 to 60 for marked animals. 2. Results were the same for marked invertebrates and those in the channels. Dispersal was not density-dependent; the number of dispersing animals was a constant proportion of the initial number for each species. The relationship between upstream or downstream dispersal distance and the number of animals travelling that distance was well described by an inverse power function for all species (exponential and log models were poorer fits). Results varied between species but were similar within species for the 4 months, and therefore were unaffected by variations in mean water velocity (range 0.04,0.35 m s,1) or water temperature (range 6.7,8.9 °C in April, 12.1,14.8 °C in June). 3. Species were arranged in order, according to their dispersal abilities. Three carnivores (Perlodes, Rhyacophila, Isoperla) dispersed most rapidly (70,91% in 24 h, maximum distances 9.5,13.5 m per day), followed by two species (Protonemura, Rhithrogena) in which about half their initial numbers dispersed (50,51% in 24 h, 7.5,8 m per day), and four species (Ecdyonurus, Hydropsyche, Gammarus, Baetis) in which less than half dispersed (33,40% in 24 h, 5.5,7 m per day). Dispersal was predominantly upstream for all nine species. Few larvae (20%) of Potamophylax dispersed, with similar maximum upstream and downstream distances of 3.5 m per day. The mean time spent drifting downstream was known for seven species from previous studies, and correlated positively with their dispersal distances. Therefore, the species formed a continuum from rapid to very slow dispersers. These interspecific differences should be considered when evaluating the role of dispersal in the maintenance of genetic diversity in stream invertebrates, and in their ability to colonise or re-colonise habitats. [source] Inaccurate or disparate temperature cues?FUNCTIONAL ECOLOGY, Issue 5 2010Seasonal acclimation of terrestrial, aquatic locomotor capacity in newts Summary 1.,Many organisms respond to seasonal temperature fluctuations by the reversible modification of whole-animal performance. Semiaquatic ectotherms, which possess this acclimatory capacity in swimming speed, lack the plastic response in terrestrial locomotor performance and vice versa. Theory predicts that the presence of reversible (seasonal) thermal acclimation or fixed phenotypes depends on the predictability of future thermal conditions (i.e. accuracy of temperature cues) in a given environment. Alternatively, comparative data suggest that thermal acclimation is induced by disparate temperature cues in water and on land. 2.,We tested both predictions by examining the seasonal acclimation response in thermal sensitivity of maximal swimming and running speed in adult alpine newts, Ichthyosaura (formerly Triturus) alpestris. 3.,Following the seasonal variation in environmental temperatures, we exposed newts to 5 °C from November to March and, after a gradual temperature increase, to either a constant (15 °C) or fluctuating (10,20 °C) thermal regime from May to June. At the end of each treatment, we measured newt swimming and running capacity at five temperatures (range 5,25 °C). In the field, hourly temperatures were recorded in various aquatic and terrestrial microhabitats to obtain information about the predictability of thermal conditions in both environments. 4.,Seasonal acclimation shaped the thermal sensitivity of swimming speed under both constant and fluctuating temperature treatments. Thermal sensitivity of running speed was markedly modified by a fluctuating thermal regime so that newts ran at the highest test temperature faster than cold-acclimated individuals. Natural thermal environment contained a similar proportion of predictable variation in water and on land. 5.,Complex seasonal acclimation of locomotor capacity in newts was influenced by the disparate thermal cues, i.e. mean acclimation temperature or diel temperature fluctuations, rather than by the different accuracy of these cues in water and on land. Future confrontations of theory with empirical data will require more attention not only on the assumptions of adaptive thermal acclimation but also on the ecologically relevant thermal conditions during acclimation experiments. [source] Drug-eluting bead therapy in primary and metastatic disease of the liverHPB, Issue 7 2009Stewart Carter Abstract Background:, Drug-eluting bead transarterial chemoembolization (DEB-TACE) is a novel therapy for the treatment of hypervascuarized tumours. Through the intra-arterial delivery of microspheres, DEB-TACE allows for embolization as well as local release of chemotherapy in the treatment of hepatic malignancy, providing an alternative therapeutic option in unresectable tumours. Its role as an adjunct to surgical resection or radiofrequency ablation (RFA) is less clear. The purpose of this review is to summarize recent studies investigating DEB-TACE in order to better define safety, efficacy and outcomes associated with its use. Methods:, A systematic review of all published articles and trials identified nine clinical trials and 23 abstracts. These were reviewed for tumour histology, stage of treatment, delivery technique, outcome at follow-up, complications and mortality rates. Results:, Publications involved treatment of hepatocellular carcinoma (HCC), metastatic colorectal carcinoma (MCRC), metastatic neuroendocrine (MNE) disease and cholangiocarcinoma (CCA). Using Response Evaluation Criteria in Solid Tumours (RECIST) or European Association for the Study of the Liver (EASL) criteria, studies treating HCC reported complete response (CR) rates of 5% (5/101) at 1 month, 9% (8/91) at 4 months, 14% (19/138) at 6 months and 25% (2/8) at 10 months. Partial response (PR) was reported as 58% (76/131) at 1 month, 50% (67/119) at 4 months, 57% (62/108) at 6,7 months and 63% (5/8) at 10 months. Studies involving MCRC, CCA and MNE disease were less valuable in terms of response rate because there is a lack of comparative data. The most common procedure-associated complications included fever (46,72%), nausea and vomiting (42,47%), abdominal pain (44,80%) and liver abscess (2,3%). Rather than reporting individual symptoms, two studies reported rates of post-embolic syndrome (PES), consisting of fever, abdominal pain, and nausea and vomiting, at 82% (75/91). Six of eight studies reported length of hospital stay, which averaged 2.3 days per procedure. Mortality was reported as occurring in 10 of 456 (2%) procedures, or 10 of 214 (5%) patients. Conclusions:, Drug-eluting bead TACE is becoming more widely utilized in primary and liver-dominant metastatic disease of the liver. Outcomes of success must be expanded beyond response rates because these are not a reliable surrogate for progression-free survival or overall survival. Ongoing clinical trials will further clarify the optimal timing and strategy of this technology. [source] A systematic review of hand-assisted laparoscopic live donor nephrectomyINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 5 2004P. Dasgupta Summary We provide a systematic review of hand-assisted laparoscopic live donor nephrectomy (HALDN), a relatively new procedure. Medline search of HALDN between 1995 and 2002 was conducted. Published studies were scored by two independent assessors using a modified form of 11 generic questions. All questions required one of three responses: 0 , criterion not reported, 1 , criterion reported but inadequate, 2 , criterion reported and adequate. The studies were placed according to their scoRes in category A (score 20,22), category B (17,19) and category C (16 or less). Higher scores indicate better quality of studies. Where possible, statistical analysis of comparative data was performed. Most reports of HALDN are expert series, some comparative and a few prospective. There was good correlation between the assessors (r = 0.91), and of the seven published series on HALDN, two fell into category B and five into category C. At present, there is only one published randomised-controlled trial of HALDN vs. open donor nephrectomy; this is the only such trial in laparoscopic urology. HALDN allows kidneys to be harvested with short operating and warm ischaemia times and fewer ureteric complications. HALDN is a relatively new and effective technique, designed to make kidney donation more attractive and minimally invasive without affecting recipient outcomes. More prospective data of this technique is needed, and wide variation in reported outcome parameters need to be standardised to allow meaningful comparison. [source] Tilly Tally: War-Making and State-Making in the Contemporary Third World,INTERNATIONAL STUDIES REVIEW, Issue 1 2008Brian D. Taylor Does the war-making/state-making thesis, most associated with Charles Tilly, apply in the developing world If so, how? This essay reviews the bellicist literature and offers an explanation for variation in state capacity among the most war-prone states in the developing world. We investigate the influence of war on state strength in two countries, Afghanistan and Vietnam. We examine three hypothesized causal mechanisms about how war contributes to state formation: raising money, building armies, and making nations. We find that war in Vietnam contributed to state-building, while war in Afghanistan has been state-destroying. There appear to be two main factors that contributed to state-making in Vietnam that were absent in Afghanistan: the existence of a core ethnic group that had served as the basis for a relatively long-standing political community in the past, and the combination of war and revolution, which inspired state officials and facilitated the promulgation of a unifying national ideology. Of these two factors, comparative data suggest relative ethnic homogeneity is the most important. Absent these specific conditions, war is more likely to break than make states in the contemporary Third World. [source] Evolutionary emergence of synaptic nervous systems: what can we learn from the non-synaptic, nerveless Porifera?INVERTEBRATE BIOLOGY, Issue 1 2010Michael Nickel Abstract. The Porifera represent one of the only two recent nerveless and muscleless metazoan phyla. Nevertheless, sponges provide behavioral, physiological, pharmacological, morphological, and, more recently, an increasing amount of genetic evidence for a paracrine pre-nervous integration system. Although this system might be derived, it allows us to draw conclusions, on the basis of comparative data, about the origin of the nervous system sensu stricto as found in the eumetazoan phyla. The goal of the present review is to compile recent evidence on the sponge integration systems. Based on this framework, new light is also shed on the evolutionary origin of the eumetazoan synaptic nervous systems, which can be regarded to form an evolutionary biochemical continuum with the paracrine signaling system in sponges. Thus, we can assume that the evolutionary transition from a paracrine-dominated, pre-nervous system to an electrochemically dominated, primordial nervous system resulted in part from compartmentalization effects. As intermediate evolutionary stages, regionalized synapse precursor areas might have occurred within pre-nervous cells, which foreshadowed the highly organized synaptic scaffolds present in recent nerve cells of the Eumetazoa. [source] Evolution of cranial development and the role of neural crest: insights from amphibiansJOURNAL OF ANATOMY, Issue 5 2005James Hanken Abstract Contemporary studies of vertebrate cranial development document the essential role played by the embryonic neural crest as both a source of adult tissues and a locus of cranial form and patterning. Yet corresponding and basic features of cranial evolution, such as the extent of conservation vs. variation among species in the contribution of the neural crest to specific structures, remain to be adequately resolved. Investigation of these features requires comparable data from species that are both phylogenetically appropriate and taxonomically diverse. One key group are amphibians, which are uniquely able to inform our understanding of the ancestral patterns of ontogeny in fishes and tetrapods as well as the evolution of presumably derived patterns reported for amniotes. Recent data support the hypothesis that a prominent contribution of the neural crest to cranial skeletal and muscular connective tissues is a fundamental property that evolved early in vertebrate history and is retained in living forms. The contribution of the neural crest to skull bones appears to be more evolutionarily labile than that of cartilages, although significance of the limited comparative data is difficult to establish at present. Results underline the importance of accurate and reliable homology assessments for evaluating the contrasting patterns of derivation reported for the three principal tetrapod models: mouse, chicken and frog. [source] Comparative foraging and nutrition of horses and cattle in European wetlandsJOURNAL OF APPLIED ECOLOGY, Issue 1 2002Catherine Menard Summary 1Equids are generalist herbivores that co-exist with bovids of similar body size in many ecosystems. There are two major hypotheses to explain their co-existence, but few comparative data are available to test them. The first postulates that the very different functioning of their digestive tracts leads to fundamentally different patterns of use of grasses of different fibre contents. The second postulates resource partitioning through the use of different plant species. As domestic horses and cattle are used widely in Europe for the management of conservation areas, particularly in wetlands, a good knowledge of their foraging behaviour and comparative nutrition is necessary. 2In this paper we describe resource-use by horses and cattle in complementary studies in two French wetlands. Horses used marshes intensively during the warmer seasons; both species used grasslands intensively throughout the year; cattle used forbs and shrubs much more than horses. Niche breadth was similar and overlap was high (Kulczinski's index 0·58,0·77). Horses spent much more time feeding on short grass than cattle. These results from the two sites indicate strong potential for competition. 3Comparative daily food intake, measured in the field during this study for the first time, was 63% higher in horses (144 gDM kg W,0·75 day,1) than in cattle (88 gDM kg W,0·75 day,1). Digestibility of the cattle diets was a little higher, but daily intake of digestible dry matter (i.e. nutrient extraction) in all seasons was considerably higher in horses (78 gDM kg W,0·75 day,1) than in cattle (51 gDM kg W,0·75 day,1). When food is limiting, horses should outcompete cattle in habitats dominated by grasses because their functional response is steeper; under these circumstances cattle will require an ecological refuge for survival during winter, woodland or shrubland with abundant dicotyledons. 4Horses are a good tool for plant management because they remove more vegetation per unit body weight than cattle, and use the most productive plant communities and plant species (especially graminoids) to a greater extent. They feed closer to the ground, and maintain a mosaic of patches of short and tall grass that contributes to structural diversity at this scale. Cattle use broadleaved plants to a greater extent than horses, and can reduce the rate of encroachment by certain woody species. [source] Monthly Oral Ibandronate Therapy in Postmenopausal Osteoporosis: 1-Year Results From the MOBILE StudyJOURNAL OF BONE AND MINERAL RESEARCH, Issue 8 2005Paul D Miller MD Abstract Once-monthly (50/50, 100, and 150 mg) and daily (2.5 mg; 3-year vertebral fracture risk reduction: 52%) oral ibandronate regimens were compared in 1609 women with postmenopausal osteoporosis. At least equivalent efficacy and similar safety and tolerability were shown after 1 year. Introduction: Suboptimal adherence to daily and weekly oral bisphosphonates can potentially compromise therapeutic outcomes in postmenopausal osteoporosis. Although yet to be prospectively shown in osteoporosis, evidence from randomized clinical trials in several other chronic conditions shows that reducing dosing frequency enhances therapeutic adherence. Ibandronate is a new and potent bisphosphonate with antifracture efficacy proven for daily administration and also intermittent administration with a dose-free interval of >2 months. This report presents comparative data on the efficacy and safety of monthly and daily oral ibandronate regimens. Materials and Methods: MOBILE is a 2-year, randomized, double-blind, phase III, noninferiority trial. A total of 1609 women with postmenopausal osteoporosis were assigned to one of four oral ibandronate regimens: 2.5 mg daily, 50 mg/50 mg monthly (single doses, consecutive days), 100 mg monthly, or 150 mg monthly. Results: After 1 year, lumbar spine BMD increased by 3.9%, 4.3%, 4.1%, and 4.9% in the 2.5, 50 /50, 100, and 150 mg arms, respectively. All monthly regimens were proven noninferior, and the 150 mg regimen superior, to the daily regimen. All monthly regimens produced similar hip BMD gains, which were larger than those with the daily regimen. All regimens similarly decreased serum levels of C-telopeptide, a biochemical marker of bone resorption. Compared with the daily regimen, a significantly larger proportion of women receiving the 100 and 150 mg monthly regimens achieved predefined threshold levels for percent change from baseline in lumbar spine (6%) or total hip BMD (3%). All regimens were similarly well tolerated. Conclusions: Monthly ibandronate is at least as effective and well tolerated as the currently approved daily ibandronate regimen in postmenopausal osteoporosis. [source] REVIEW: The evolution of polyembryony in parasitoid waspsJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 9 2010M. SEGOLI Abstract Polyembryony has evolved independently in four families of parasitoid wasps. We review three main hypotheses for the selective forces favouring this developmental mode in parasitoids: polyembryony (i) reduces the costs of egg limitation; (ii) reduces the genetic conflict among offspring; and (iii) allows offspring to adjust their numbers to the quality of the host. Using comparative data and verbal and mathematical arguments, we evaluate the relative importance of the different selective forces through different evolutionary stages and in the different groups of polyembryonic wasps. We conclude that reducing the cost of egg limitation is especially important when large broods are favoured. Reducing genetic conflict may be most important when broods are small, thus might have been important during, or immediately following, the initial transition from monoembryony to polyembryony. Empirical data provide little support for the brood-size adjustment hypothesis, although it is likely to interact with other selective forces favouring polyembryony. [source] Population differences in behaviour are explained by shared within-population trait correlationsJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 4 2010JONATHAN N. PRUITT Abstract Correlations in behavioural traits across time, situation and ecological context (i.e. ,behavioural syndromes' or ,personality') have been documented for a variety of behaviours, and in diverse taxa. Perhaps the most controversial inference from the behavioural syndromes literature is that correlated behaviour may act as an evolutionary constraint and evolutionary change in one's behaviour may necessarily involve shifts in others. We test the two predictions of this hypothesis using comparative data from eighteen populations of the socially polymorphic spider, Anelosimus studiosus (Araneae, Theriidae). First, we ask whether geographically distant populations share a common syndrome. Second, we test whether population differences in behaviour are correlated similarly to within-population trait correlations. Our results reveal that populations separated by as much as 36° latitude shared similar syndromes. Furthermore, population differences in behaviour were correlated in the same manner as within-population trait correlations. That is, population divergence tended to be along the same axes as within-population covariance. Together, these results suggest a lack of evolutionary independence in the syndrome's constituent traits. [source] Nestling coloration is adjusted to parent visual performance in altricial birds irrespective of assumptions on vision system for Laniidae and owls, a reply to Renoult et al.JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 1 2010J. M. AVILÉS Abstract We have recently published support to the hypothesis that visual systems of parents could affect nestling detectability and, consequently, influences the evolution of nestling colour designs in altricial birds. We provided comparative evidence of an adjustment of nestling colour designs to the visual system of parents that we have found in a comparative study on 22 altricial bird species. In this issue, however, Renoult et al. (J. Evol. Biol., 2009) question some of the assumptions and statistical approaches in our study. Their argumentation relied on two major points: (1) an incorrect assignment of vision system to four out of 22 sampled species in our study; and (2) the use of an incorrect approach for phylogenetic correction of the predicted associations. Here, we discuss in detail re-assignation of vision systems in that study and propose alternative interpretation for current knowledge on spectrophotometric data of avian pigments. We reanalysed the data by using phylogenetic generalized least squares analyses that account for the alluded limitations of phylogenetically independent contrasts and, in accordance with the hypothesis, confirmed a significant influence of parental visual system on gape coloration. Our results proved to be robust to the assumptions on visual system evolution for Laniidae and nocturnal owls that Renoult et al. (J. Evol. Biol., 2009) study suggested may have flawed our early findings. Thus, the hypothesis that selection has resulted in increased detectability of nestling by adjusting gape coloration to parental visual systems is currently supported by our comparative data. [source] Testosterone, growth and the evolution of sexual size dimorphismJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 8 2009R. M. COX Abstract The integration of macroevolutionary pattern with developmental mechanism presents an outstanding challenge for studies of phenotypic evolution. Here, we use a combination of experimental and comparative data to test whether evolutionary shifts in the direction of sexual size dimorphism (SSD) correspond to underlying changes in the endocrine regulation of growth. First, we combine captive breeding studies with mark-recapture data to show that male-biased SSD develops in the brown anole lizard (Anolis sagrei) because males grow significantly faster than females as juveniles and adults. We then use castration surgeries and testosterone implants to show that castration inhibits, and testosterone stimulates, male growth. We conclude by reviewing published testosterone manipulations in other squamate reptiles in the context of evolutionary patterns in SSD. Collectively, these studies reveal that the evolution of SSD has been accompanied by underlying changes in the effect of testosterone on male growth, potentially facilitating the rapid evolution of SSD. [source] Tempo and mode in evolution: phylogenetic inertia, adaptation and comparative methodsJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 6 2002S. P. Blomberg Abstract Before the Evolutionary Synthesis, ,phylogenetic inertia' was associated with theories of orthogenesis, which claimed that organisms possessed an endogenous perfecting principle. The concept in the modern literature dates to Simpson (1944), who used ,evolutionary inertia' as a description of pattern in the fossil record. Wilson (1975) used ,phylogenetic inertia' to describe population-level or organismal properties that can affect the course of evolution in response to selection. Many current authors now view phylogenetic inertia as an alternative hypothesis to adaptation by natural selection when attempting to explain interspecific variation, covariation or lack thereof in phenotypic traits. Some phylogenetic comparative methods have been claimed to allow quantification and testing of phylogenetic inertia. Although some existing methods do allow valid tests of whether related species tend to resemble each other, which we term ,phylogenetic signal', this is simply pattern recognition and does not imply any underlying process. Moreover, comparative data sets generally do not include information that would allow rigorous inferences concerning causal processes underlying such patterns. The concept of phylogenetic inertia needs to be defined and studied with as much care as ,adaptation'. [source] Management of skin toxicity during radiation therapy: A review of the evidenceJOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 3 2010S Kumar Summary Acute skin toxicity occurs in the majority of the patients undergoing radical radiotherapy. While a variety of topical agents and dressing are used to ameliorate side effects, there is minimal evidence to support their use. The aims of this study were to systematically review evidence on acute skin toxicity management and to assess the current practices in ANZ. A systematic review of the literature was conducted on studies published between 1980 and 2008. A meta-analysis was performed on articles on clinical trials reporting grade II or greater toxicity. Analyses were divided into breast (the most common site) and other sites. A survey of Radiation Oncology departments across ANZ was conducted to identify patterns of practices and compare these with the published evidence. Twenty-nine articles were reviewed. Only seven articles demonstrated statistically significant results for management of side-effects. These were for topical corticosteroids, hyaluronic acid, sucralfate, calendula, Cavilon cream (3M, St Paul, Minnesota, USA) and silver leaf dressing. Meta-analysis demonstrated statistical significance for the prophylactic use of topical agents in the management acute toxicity. The survey of departments had a low response rate but demonstrated variation in skin care practices across ANZ. A considerable number of these practices were based only on anecdotal evidence. Lack of evidence in the literature for the care of radiation skin reactions was associated with variation in practice. Only a limited number of studies have demonstrated a significant benefit of specific topical agents. There is a need for objective and prospective recording of skin toxicity to collect meaningful comparative data on which to base recommendations for practice. [source] Flexural Strength, Elastic Modulus, and pH Profile of Self-etch Resin Luting CementsJOURNAL OF PROSTHODONTICS, Issue 4 2008Egle Saskalauskaite DDS Abstract Purpose: To determine the flexural strength, modulus of elasticity, and 24-hour pH profile of three self-etching resin luting cements and to obtain comparative data for representative conventional resin and resin-modified glass ionomer luting cements. Materials and Methods: Three self-etching resin luting cements [RelyX Unicem (3M ESPE), Maxcem (Kerr), Embrace Wetbond (Pulpdent)] were tested and compared with two conventional resin cements [RelyX ARC (3M ESPE), Linkmax (GC)] plus two resin-modified glass ionomer luting cements [Fuji Plus (GC), RelyX Luting Plus (3M ESPE)]. Flexural strength and modulus of elasticity were determined using bar-shaped specimens (2 × 2 × 25 mm3) at 24 hours, using an Instron universal testing machine. Setting pH was measured using a flat-surface pH electrode at 0, 2, 5, 15, and 30 minutes and 1, 2, 4, 6, and 24 hours after mixing. Testing was performed under both dual-cured and self-cured conditions for all dual-cure cements. Data analysis included ANOVA and Tukey's test (p < 0.05). Results: The self-etching cements showed similar flexural strength to the conventional resin cements, except for Embrace Wetbond self-cured, which was considerably lower. Modulus of elasticity results were both higher and lower than for conventional resin cements. All photopolymerized conventional and self-etch dual-cure cements showed markedly higher flexural strength and modulus than when solely self-cured. The resin-modified glass ionomer cements were characterized by lower flexural strength and elastic modulus. Self-etching resin cements showed lower initial pH (2.0 to 2.4) than conventional resin cements (4.8 to 5.2) and a wide range of final pH values (3.9 to 7.3) at 24 hours. One self-etching cement (Unicem) revealed a unique pH profile characterized by a more rapid rise in pH to neutrality both when dual-cured (15 minutes) and when auto-cured (1 hour). Conclusions: The self-etching resin cements evaluated in this study displayed disparate properties and cannot be considered a homogeneous group. Flexural strength properties were most uniform and were similar to those of the conventional resin cements, whereas moduli of elasticity showed greater variation. Setting pH profiles differed, depending on the brand and mode of cure, even within the same category of luting cement. All cements with dual-cure capability, both conventional and self-etch, showed significantly superior properties when photopolymerized. [source] | |||||||||||||||||||||||||||||||||||||