bluuebunny/crossref_metadata_2025_split huggingface dataset:
The evolutionary fate of recently duplicated retrogenes in mice
Authors: GAYRAL P. , CAMINADE P. , BOURSOT P. , GALTIER N. 
Published: October 2006

AbstractInferences about the evolutionary impact of gene duplications often rely on the analysis of their long‐term outcome. The fate of the majority of them must, however, be decided shortly after duplication. Here we analysed the evolutionary pattern of 10 mouse genes very recently duplicated by retrotransposition, by sequencing the retroposed copy in five to 10 closely related mouse species. In all cases the retroposed copy experienced accelerated nonsynonymous evolution whereas the divergence pattern of the source copy appeared unaffected by the duplication, consistent with the neofunctionalization model. The analysis further revealed that most retrogenes, including pseudogenes, did not experience a period of relaxed neutral evolution, but have been submitted to purifying selection ever since their retroposition. We propose that these duplicates play a biochemical role but are not indispensable. Purifying selection prevents them from acquiring a negative role until they are lost or silenced. This period of unnecessary redundancy could in rare cases give the time for new functions to evolve.
Foraging performance of diet‐induced morphotypes in pumpkinseed sunfish (Lepomis gibbosus) favours resource polymorphism
Authors: PARSONS K. J. , ROBINSON B. W. 
Published: October 2006

AbstractMorphological plasticity can influence adaptive divergence when it affects fitness components such as foraging performance. We induced morphological variation in pumpkinseed sunfish (Lepomis gibbosus) ecomorphs and tested for effects on foraging performance. Young‐of‐year pumpkinseed sunfish from littoral and pelagic lake habitats were reared each on a ‘specialist diet’ representing their native habitat‐specific prey, or a ‘generalist diet’ reflecting a combination of native and non‐native prey. Specialist and generalist diets, respectively, induced divergent and intermediate body forms. Specialists had the highest capture success on their native prey whereas generalist forms were inferior. Specialists faced trade‐offs across prey types. However, pelagic specialists also had the highest intake rate on both prey types suggesting that foraging trade‐offs are relaxed when prey are abundant. This increases the likelihood of a resource polymorphism because the specialized pelagic form can be favoured by directional selection when prey are abundant and by diversifying selection when prey resources are restricted.
Morphological and genetic divergence of intralacustrine stickleback morphs in Iceland: a case for selective differentiation?
Authors: ÓLAFSDÓTTIR G. Á. , SNORRASON S. S. , RITCHIE M. G. 
Published: October 2006

AbstractThe evolutionary processes involved in population divergence and local adaptation are poorly understood. Theory predicts that divergence of adjacent populations is possible but depends on several factors including gene flow, divergent selection, population size and the number of genes involved in divergence and their distribution on the genome. We analyse variation in neutral markers, markers linked to putative quantitative trait loci and morphological traits in a recent (< 10 000 years) zone of primary divergence between stickleback morphs in Lake Thingvallavatn, Iceland. Environmental factors, especially predation, are clearly implicated in reducing gene flow between morphs. There is continuous morphological and genetic variation between habitats with a zone centre similar to secondary contact zones. Individual microsatellite loci are implicated as being linked to adaptive variation by direct tests as well as by differences in cline shape. Patterns of linkage disequilibria indicate that the morphs have diverged at several loci. This divergence shows parallels and differences with the well‐studied limnetic–benthic stickleback morphs, both in phenotypic divergence and at the genomic level.
Are juvenile coral‐trouts (Plectropomus) mimics of poisonous pufferfishes (Canthigaster) on coral reefs?
Authors: Frisch Ashley J. 
Published: October 2006

AbstractThe juveniles of three species of coral‐trout (Plectropomus) resemble two species of poisonous pufferfish (Canthigaster), one of the latter having two distinct colour morphs. Qualitative data are assembled on the diet, feeding mode, palatability, relative abundance, habitat and geographical range of each species. All observations are consistent with the hypothesis that juvenile coral‐trouts are generalized mimics of pufferfishes. Speciation within Plectropomus is discussed with respect to its mimetic relationships with Canthigaster.
Community structure of fishes in Cabo Pulmo Reef, Gulf of California
Authors: Alvarez‐Filip Lorenzo , Reyes‐Bonilla Héctor , Calderon‐Aguilera Luis E. 
Published: October 2006

AbstractIn order to analyse the structure of the fish community in Cabo Pulmo Reef., 36 cylindrical stationary censuses (5 m radius, 15 min of observation time) were conducted in October 2003 (warm season) and February 2004 (cold season). To explore the relationship with depth and associated variables, we considered a shallow stratum (<5 m) and a deep stratum (>5.5 m; depth range was between 2 and 15 m). Species richness, number of individuals, and the indices of diversity (Shannon), evenness (Pielou) and taxonomic distinctness were computed for each census. A total of 8725 fish were recorded (3829 in the warm season and 4896 in the cold season), belonging to 62 species, included in 23 families. Thalassoma lucasanum and Chromis atrilobata were the dominant species (62.5% of total abundance, and occurrence of 97% and 72%, respectively). Conversely, 50 species had low relative abundance, <1% of total abundance, and a frequency of occurrence <50% of the census. None of the ecological descriptors were significantly different between seasons (P > 0.5), but richness, abundance and taxonomic differentiation were higher in the deeper zone. The analysis of similarity and ordination analysis did not show consistent clusters by season or depth, but suggest similarity among census of deeper zones. Most species preference for physical factors associated with deeper zones maybe the reason for the pattern observed in this study.
Microbial status in seawater and coastal sediments during pre‐ and post‐tsunami periods in the Bay of Bengal, India
Authors: Ramesh Subramani , Jayaprakashvel Mani , Mathivanan Narayanasamy 
Published: October 2006

AbstractTsunami, the natural disaster, which occurred on December 26, 2004 in the Indian Ocean, caused severe damage to mankind in the coastal areas. Total loss of life and economic loss because of this disaster have been estimated by various agencies but its effect on microbial density has not been probed. With our previous results on microbial populations in four locations of the Chennai coast of the Bay of Bengal, India in the pre‐tsunami period, the change in microbial populations was studied after the tsunami at regular intervals in the same locations. Coastal sediment and seawater samples were collected from four different locations after 5–10 h and thereafter at intervals of every 7 days up to 28 days post‐tsunami. Bacteria, fungi and actinomycetes were isolated from the marine samples by serial dilution on respective media. Before the tsunami, the bacterial population was higher in seawater samples than the sediments, whereas fungi and actinomycetes were recorded only in the sediments. The microbial population remarkably increased 5–10 h post‐tsunami in all the marine samples irrespective of the location. However, it slowly declined in the subsequent days and became similar to that of the population recorded before the tsunami. The population of gram‐positive bacteria increased whereas the gram‐negative bacterial population decreased after the tsunami. Further, populations of pathogenic bacteria such as coliform and vibrios did not increase after the tsunami. It has been observed that the increase in populations of bacteria and actinomycetes even after 28 days of tsunami may be due to the introduction of foreign microorganisms that developed the ability to survive in the extreme environment by exhibiting special characteristics such as pigmentation and production of exopolysaccharides.
Response of the soft coral Heteroxenia fuscescens to ultraviolet radiation regimes as reflected by mycosporine‐like amino acid biosynthesis
Authors: Zeevi Ben‐Yosef Dafna , Kashman Yoel , Benayahu Yehuda 
Published: October 2006

AbstractThe variation in mycosporine‐like amino acid (MAA) concentration in the soft coral Heteroxenia fuscescens in relation to changes in ultraviolet radiation (UVR) regimes was investigated at the Gulf of Eilat, northern Red Sea. Solar radiation (300–700 nm) was measured for different depths and seasons. The UVR irradiance was measured to a depth of 25 m on the reef. The mean attenuation coefficient for UV‐B measured in winter was twofold that of the summer value. Separation of H. fuscescens extracts by reverse‐phase isocratic high‐performance liquid chromatography revealed a single MAA compound, palythine (λmax = 320 nm). Possible seasonal changes in MAAs in colonies of H. fuscescens along a depth gradient were examined on different dates. Palythine concentrations in the colonies were significantly higher in summer than in the other seasons particularly in shallow water. Possible changes in MAA content in colonies of H. fuscescens as a result of UVR protection, were determined by experiments conducted for periods of 1 week, 1 month and 3 months, at a depth of 5 m. In these experiments colonies were removed from the natural substrate and placed underwater, protected from UVR by a PVC filter. Significant differences between UV‐exposed and protected colonies of H. fuscescens were found only in the 3‐month experiment conducted during the summer. These findings demonstrate that UVR is an important environmental factor regulating MAA biosynthesis in the soft coral H. fuscescens.
International Trade, Technology, and the Wage Gap: Evidence from Granger‐causality Tests*
Authors: Ghosh Sucharita , Yamarik Steven 
Published: October 2006

AbstractIn this paper, we propose an alternative approach under which to examine the source of the increased wage gap between skilled and unskilled workers in US manufacturing. Rather than imposing the assumptions inherent in a given structural form, we posit a long‐run equilibrium relationship between international trade, technology, and the wage premium using a vector error‐correction model. We first test for the existence of a long‐run relationship using cointegration tests. If a cointegrating relationship is found, we then conduct tests on the direction of the long‐run relationship and of Granger causality. We apply our approach to each two‐digit and four‐digit SIC industry and find evidence in support of international trade being an important source of the wage gap. Our results suggest that it is premature to dismiss international trade as a possible suspect behind the rising wage premium.
The Effect of EMU on Tourism*
Authors: Gil‐Pareja Salvador , Llorca‐Vivero Rafael , Martínez‐Serrano José Antonio 
Published: October 2006

AbstractThis paper estimates the effect of the euro on intra‐EMU tourist flows by using a panel dataset of 20 OECD countries over the period 1995–2002. The results reveal that the euro has increased tourism, with an effect of around 6.5%. This is a noticeable impact given the early stage of the EMU analyzed. The robustness checks show that the evidence of a positive impact is quite widespread across EMU destination countries.
Craniofacial levels and the morphological maturation of the human skull
Authors: Bastir Markus , Rosas Antonio , O’Higgins Paul 
Published: October 2006

AbstractIt is well known that the human skull achieves adult size through a superior–inferior gradient of maturation. Because the basicranium matures in size before the face, it has been suggested that the form of the basicranium might have ontogenetic knock‐on effects on that of the face. However, although sequential spatially organized maturation of size is well described in the cranium, the maturation of skull shape is not. Knowledge of the maturation of shape is important, nevertheless, because it is claimed that the early determination of the spatial configuration of basicranial components, where the facial skeleton attaches, is relevant in the spatio‐temporal ontogenetic cascade from basicranium to face. This paper examines the ontogeny of various components of the human skull in 28 individuals from the longitudinal Denver Growth Study. Sixty‐six landmarks and semilandmarks were digitized on 228 X‐rays and analysed using geometric morphometric methods. Bootstrapped confidence intervals for centroid size support previous studies suggesting a supero‐inferior gradient of growth maturation (size over time), while developmental maturation (shape over time) is more complex. A sequence of shape maturation is described, in which the earliest structure to mature in shape was the midline cranial base (7–8 years), followed by the lateral cranial floor (11–12), midline neurocranium (9–10) and facial and mandibular structures (15–16). The absolute ages of shape maturation of the latter three depended on the criterion of maturity used, which was not the case for the basicranial components. Additionally, ontogenetic dissociations were found between the maturation of size and shape of the midline cranial base and lateral floor, possibly underlining its role as structural ‘interface’ between brain and facial ontogeny. These findings imply potential for bidirectional developmental influences between the lateral cranial floor and the face until about 11–12 years. The findings are discussed with regard to their relevance for palaeoanthropology and especially the evolutionary and developmental bases of skull morphological variation.
Chilean women’s preferences regarding mode of delivery: which do they prefer and why?
Authors: Angeja ACE , Washington AE , Vargas JE , Gomez R , Rojas I , Caughey AB 
Published: October 2006

Objective  Caesarean section rates in Chile are reported to be as high as 60% in some populations. The purpose of this study was to determine pregnant Chilean women’s preferences towards mode of delivery.Design  Interviewer‐administered cross‐sectional survey.Setting  Prenatal clinics in Santiago, Chile.Population  Pregnant women in Santiago, Chile.Methods  Of 180 women completing the questionnaire, 90 were interviewed at a private clinic (caesarean delivery rate 60%) and 90 were interviewed at a public clinic (cesarean delivery rate 22%). Data collected included demographics, preferred mode of delivery, and women’s attitudes towards vaginal and caesarean deliveries.Main outcome measures  Mode of delivery preferences, perceptions of mode of delivery measured on a 1–7 Likert scale.Results  The majority of women (77.8%) preferred vaginal delivery, 9.4% preferred caesarean section, and 12.8% had no preference. There was no statistical difference in preference between the public clinic (11% preferred caesarean) and the private clinic (8% preferred caesarean, P= 0.74). Overall, women preferring caesarean birth were slightly older than other groups (31.6 years, versus 28.4 years for women who preferred vaginal and 27.3 years for women who had no preference, P= 0.05), but there were otherwise no differences in parity, income, or education. On a scale of 1–7, women preferring caesarean birth rated vaginal birth as more painful, while women preferring vaginal birth rated it as less painful (5.8 versus 3.7, P= 0.003). Whether vaginal or caesarean, each group felt that their preferred mode of delivery was safer for their baby (P < 0.001).Conclusions  Chilean women do not prefer caesarean section to vaginal delivery, even in a practice setting where caesarean delivery is more prevalent. Thus, women’s preferences is unlikely to be the most significant factor driving the high caesarean rates in Chile.
Extracellular S‐nitrosoglutathione, but not S‐nitrosocysteine or N2O3, mediates protein S‐nitrosation in rat spinal cord slices*
Authors: Romero Jorge M. , Bizzozero Oscar A. 
Published: October 2006

SummaryThere is evidence that protein S‐nitrosothiols (PrSNOs) accumulate in inflammatory demyelinating disorders like multiple sclerosis and experimental allergic encephalomyelitis. However, very little is known regarding the mechanism by which PrSNOs are formed in target cells. The present study compares the ability of potential intercellular mediators of nitrosative damage including S‐nitrosoglutathione (GSNO), S‐nitrosocysteine and N2O3 to induce protein S‐nitros(yl)ation in the spinal cord, a CNS region that is commonly affected in multiple sclerosis and experimental allergic encephalomyelitis. The results clearly demonstrate that while all three NO‐donors cause S‐nitrosation of proteins in cell‐free systems, only GSNO is a viable S‐nitrosating agent in rat spinal cord slices. Generation of PrSNOs with GSNO occurs by S‐transnitrosation as the process was not inhibited by either the NO‐scavenger rutin or the N2O3‐scavenger azide. Contrary to other cell types, nerve cells incorporate intact GSNO and neither functional l‐amino acid transporters nor cell‐surface thiols are required. We also found that there is a restricted number of proteins available for S‐nitrosation, even at high, non‐physiological concentrations of GSNO. These proteins are highly concentrated in mitochondria and mitochondria‐rich subcellular compartments. This study is relevant to those CNS disorders characterized by excessive nitric oxide production.
Low‐Dose Topiramate Versus Lamotrigine in Migraine Prophylaxis (The Lotolamp Study)
Authors: Gupta Praveen , Singh Sumit , Goyal Vinay , Shukla Garima , Behari Madhuri 
Published: October 2006

Objective.—To assess the efficacy and safety of topiramate and lamotrigine for prophylaxis in patients with frequent migraine as compared to each other and to placebo.Methods.—Sixty patients with frequent migraine (more than 4 attacks per month) from the headache clinic at a tertiary referral centre in India were randomized to receive 50 mg topiramate/lamotrigine or matching placebo for 1 month each in 2 divided doses in 4 phases in a crossover manner with a washout period of 7 days in between. Primary efficacy measure was responder rate (50% decrease in mean migraine frequency/intensity). Secondary efficacy measures included reduction in mean monthly frequency, intensity, duration, rescue medication use, migraine associated symptoms, and adverse events.Statistical analysis.—Analysis was on intention to treat basis. Data were analyzed as correlated data. Generalized estimation equation was used to compute overall mean standard deviation and 95% confidence intervals for each of the outcome variables. Bonferroni's correction done for multiple comparisons. P value of <.017 was taken as significant.Results.—Fifty‐seven patients comprised the intent‐to‐treat population. Four patients withdrew from the study at various phases, none because of the side effects. Responder rate for frequency was significantly higher for topiramate versus placebo (63% vs 30%, P < .001), and versus lamotrigine (63% vs 46 %, P= .02). For intensity of headache also a responder rate of topiramate versus placebo (50% vs 10%, P < .001), and versus lamotrigine (50% vs 41%, P= .01) was observed. Topiramate showed statistically significant benefits (P < .017) in most of the secondary efficacy measures while lamotrigine was beneficial for reduction in headache frequency, and migraine associated symptoms. Adverse events were similar.Conclusion.—Low‐dose topiramate is efficacious in migraine prophylaxis as compared to both placebo and lamotrigine. Lamotrigine in low doses might be beneficial for headache frequency; however, longer trials are required to establish its efficacy on the intensity and frequency of migraine.
Quatrefoil Reentry Caused by Burst Pacing
Authors: JANKS DEBORAH L. , ROTH BRADLEY J. 
Published: October 2006

Background: Experiments and clinical studies have shown that high‐frequency (burst) pacing can induce reentry and fibrillation without a strong shock. We hypothesize that a train of weak stimuli induces quatrefoil reentry, and investigate the mechanism and threshold for this mode of reentry induction. Methods: We apply a train of weak stimuli at different pacing rates to determine the threshold necessary to induce quatrefoil reentry. Numerical calculations are used to simulate cardiac tissue, based on the bidomain model with unequal anisotropy ratios. We consider both anodal and cathodal stimuli. Results: Quatrefoil reentry is initiated using much smaller currents during burst pacing (0.9 mA) compared to a single premature pulse (8.6 mA). As we varied the pacing rate, we observed reentry at the border between different modes of phase locking, such as between 1:1 and 2:1 responses. Conclusion: Burst pacing can significantly reduce the threshold for reentry. However, the extreme sensitivity of reentry induction to the exact number of stimuli in the pulse train makes the method difficult to use as a consistent, reproducible way to induce reentry.
Leaf Epidermal Cells: A Trap for Lipophilic Xenobiotics
Authors: Liu Zhiqian 
Published: October 2006

AbstractPlant surfaces are covered by a layer of cuticle, which functions as a natural barrier to protect plants from mechanical damage, desiccation, and microbial invasion. Results presented in this report show that the epicuticular wax and the cuticle of plant leaves also play an important role in resisting xenobiotic invasion. Although the epicuticular wax is impermeable to hydrophilic xenobiotics, the cuticle not only restricts the penetration of hydrophilic compounds into leaf cells, but also traps lipophilic ones. The role of the epidermal cells of plant leaves in resisting xenobiotic invasion has been neglected until now. The present study shows, for the first time, that the epidermal cells may reduce or retard the transport of lipophilic xenobiotics into the internal tissues through vacuolar sequestration. Although the guard cells appear to be an easy point of entry for xenobiotics, only a very small proportion of xenobiotics present on the leaf surface actually moves into leaf tissues via the guard cells.(Managing editor: Wei Wang)
A New Pregnane from Munronia delavayi Franch (Meliaceae)
Authors: Cai Xiang‐Hai , Luo Xiao‐Dong , Zhou Jun , Hao Xiao‐Jiang 
Published: October 2006

AbstractTo search for pharmacologically active constituents of folk medicine, a new pregnane, 2α,3α,15β‐trihy‐droxy‐20(S)‐tigloyl‐pregnane (compound 1), and nine known compounds, geranylgeraniol (compound 2), β‐daucosterol (compound 3), 6‐hydroxystigmast‐4‐en‐3‐one (compound 4), sitoindoside I (compound 5), sitoindoside II (compound 6), β‐sitosterol (compound 7), kaempferol (compound 8), quercetin (compound 9), and rutin (compound 10), were isolated from the ethanol extract of whole plants of Munronia delavayi Franch using chromatographic methods. The structures of compounds 1–10 were elucidated on the basis of spectral data.(Managing editor: Wei Wang)