bluuebunny/crossref_metadata_2025_split huggingface dataset:
Colour vision and speciation in Lake Victoria cichlids of the genus Pundamilia
Authors: CARLETON KAREN L. , PARRY JULIET W. L. , BOWMAKER JAMES K. , HUNT DAVID M. , SEEHAUSEN OLE 
Published: October 2005

AbstractLake Victoria cichlids are one of the most speciose groups of vertebrates. Selection on coloration is likely playing an important role in their rapid speciation. To test the hypothesis that sensory biases could explain species differences in mating preferences and nuptial coloration, we studied seven populations of four closely related species of the genus Pundamilia that differ in visual environment and male nuptial colour. Microspectrophotometry determined that the wavelength of maximum absorption (λmax) of the rod pigment and three cone pigments were similar in all four species. Only the long wavelength sensitive (LWS) pigment varied among species, with 3–4 nm shifts in λmax that correlated with differences in the LWS opsin sequence. These subtle shifts in λmax coincided with large shifts in male body colour, with red species having longer LWS pigments than blue species. Furthermore, we observed within and between species a correlation between water transparency and the proportion of red/red vs. red/green double cones. Individuals from turbid water had more red/red double cones than individuals from clear water. The variation in LWS λmax and in the proportion of red/red double cones could lead to differences in perceived brightness that may explain the evolution of variation in male coloration. However, other factors, such as chromophore shifts and higher order neural processing, should also be investigated to fully understand the physiological basis of differential responses to male mating hues in cichlid fish.
Bayesian inference of evolutionary history from chloroplast microsatellites in the cosmopolitan weed Capsella bursa‐pastoris (Brassicaceae)
Authors: CEPLITIS ALF , SU YINGTAO , LASCOUX MARTIN 
Published: October 2005

AbstractBesides showing an extraordinary degree of phenotypic variability, Capsella bursa‐pastoris (Brassicaceae) is also one of the world's most common plant species and a serious weed in many countries. We have employed a coalescent‐based Bayesian analysis of chloroplast microsatellite data to infer demographic and evolutionary parameters of this species. Two different demographic models applied to data from seven chloroplast microsatellite loci among 59 accessions show that the effective population size of C. bursa‐pastoris is very small indicating a rapid expansion of the species, a result that is in accordance with fossil and historical data. Against this background, analysis of flowering time variation among accessions suggests that ecotypic differentiation in flowering time has occurred recently in the species’ history. Finally, our results also indicate that mononucleotide repeat loci in the chloroplast genome can deteriorate in relatively short periods of evolutionary time.
Microsatellite DNA analysis shows that greater sage grouse leks are not kin groups
Authors: GIBSON ROBERT M. , PIRES DEBRA , DELANEY KATHLEEN S. , WAYNE ROBERT K. 
Published: October 2005

AbstractThe spectacular social courtship displays of lekking birds are thought to evolve via sexual selection, but this view does not easily explain the participation of many males that apparently fail to mate. One of several proposed solutions to this ‘lek skew paradox’ is that kin selection favours low‐ranking males joining leks to increase the fitness of closely related breeders. We investigated the potential for kin selection to operate in leks of the greater sage grouse, Centrocercus urophasianus, by estimating relatedness between lekking males using microsatellite DNA markers. We also calibrated these estimates using data from known families. Mean relatedness within leks was statistically indistinguishable from zero. We also found no evidence for local clustering of kin during lek display, although males tended to range closer to kin when off the lek. These results make kin selection an unlikely solution to the lek skew paradox in sage grouse. Together with other recent studies, they also raise the question of why kin selection apparently promotes social courtship in some lekking species, but not in others.
Nck‐independent actin assembly is mediated by two phosphorylated tyrosines within enteropathogenic Escherichia coli Tir
Authors: Campellone Kenneth G. , Leong John M. 
Published: October 2005

SummaryEnteropathogenic Escherichia coli (EPEC) stimulates tyrosine‐kinase signalling cascades to trigger localized actin assembly within mammalian cells. During actin ‘pedestal’ formation, the EPEC effector protein Tir is translocated into the plasma membrane, becomes phosphorylated on tyrosine‐474 (Y474) and promotes recruitment of the mammalian adaptor protein Nck to efficiently activate N‐WASP‐Arp2/3‐mediated actin polymerization. Tir also triggers localized actin assembly in the absence of Nck, but the Tir sequences involved in this signalling cascade have not been defined. To identify and characterize the phosphotyrosines that contribute to Nck‐independent pedestal formation, we investigated the regulation of Tir tyrosine phosphorylation and found that phosphorylation is stimulated by Tir clustering. In addition to Y474, residue Y454 is also phosphorylated, although at lower efficiency. These tyrosines differentially contribute to actin polymerization in a fashion reminiscent of actin ‘tail’ formation mediated by the vaccinia virus envelope protein A36R, which utilizes two similarly spaced phosphotyrosines to recruit the adaptors Nck and Grb2, respectively, in order to stimulate N‐WASP. Neither phosphorylated Y454 nor Y474 directly bind Grb2, but Tir derivatives harbouring these residues ultimately recruit N‐WASP and Arp2/3 independently of Nck, suggesting that EPEC exploits additional phosphotyrosine‐binding adaptors capable of initiating actin assembly.
All four Mycobacterium tuberculosis glnA genes encode glutamine synthetase activities but only GlnA1 is abundantly expressed and essential for bacterial homeostasis
Authors: Harth Günter , Masleša‐Galić Saša , Tullius Michael V. , Horwitz Marcus A. 
Published: October 2005

SummaryGlutamine synthetases (GS) are ubiquitous enzymes that play a central role in every cell's nitrogen metabolism. We have investigated the expression and activity of all four genomic Mycobacterium tuberculosis GS – GlnA1, GlnA2, GlnA3 and GlnA4 – and four enzymes regulating GS activity and/or nitrogen and glutamate metabolism – adenylyl transferase (GlnE), γ‐glutamylcysteine synthase (GshA), UDP‐N‐acetylmuramoylalanine‐d‐glutamate ligase (MurD) and glutamate racemase (MurI). All eight genes are located in multigene operons except for glnA1, and all are transcribed in M. tuberculosis; however, some are not translated or translated at such low levels that the enzymes escape detection. Of the four GS, only GlnA1 can be detected. Each of the eight genes, as well as the glnA1–glnE–glnA2 cluster, was expressed separately in Mycobacterium smegmatis, and its gene product was characterized and assayed for enzymatic activity by analysing the reaction products. In M. smegmatis, all four recombinant‐overexpressed GS are multimeric enzymes exhibiting GS activity. Whereas GlnA1, GlnA3 and GlnA4 catalyse the synthesis of l‐glutamine, GlnA2 catalyses the synthesis of d‐glutamine and d‐isoglutamine. The generation of mutants in M. tuberculosis of the four glnA genes, murD and murI demonstrated that all of these genes except glnA1 are nonessential for in vitro growth. l‐methionine‐S,R‐sulphoximine (MSO), previously demonstrated to inhibit M. tuberculosis growth in vitro and in vivo, strongly inhibited all four GS enzymes; hence, the design of MSO analogues with an improved therapeutic to toxic ratio remains a promising strategy for the development of novel anti‐M. tuberculosis drugs.
Characterization of point mutations in the cdtA gene of the cytolethal distending toxin of Actinobacillus actinomycetemcomitans
Authors: Cao Linsen , Volgina Alla , Huang Chuang‐ming , Korostoff Jonathan , DiRienzo Joseph M. 
Published: October 2005

SummaryThe Cdt is a family of gram‐negative bacterial toxins that typically arrest eukaryotic cells in the G0/G1 or G2/M phase of the cell cycle. The toxin is a heterotrimer composed of the cdtA, cdtB and cdtC gene products. Although it has been shown that the CdtA protein subunit binds to cells in culture and in an enzyme‐linked immunosorbent assay (CELISA) the precise mechanisms by which CdtA interacts with CdtB and CdtC has not yet been clarified. In this study we employed a random mutagenesis strategy to construct a library of point mutations in cdtA to assess the contribution of individual amino acids to binding activity and to the ability of the subunit to form biologically active holotoxin. Single unique amino acid substitutions in seven CdtA mutants resulted in reduced binding of the purified recombinant protein to Chinese hamster ovary cells and loss of binding to the fucose‐containing glycoprotein, thyroglobulin. These mutations clustered at the 5′‐ and 3′‐ends of the cdtA gene resulting in amino acid substitutions that resided outside of the aromatic patch region and a conserved region in CdtA homologues. Three of the amino acid substitutions, at positions S165N (mutA81), T41A (mutA121) and C178W (mutA221) resulted in gene products that formed holotoxin complexes that exhibited a 60% reduction (mutA81) or loss (mutA121, mutA221) of proliferation inhibition. A similar pattern was observed when these mutant holotoxins were tested for their ability to induce cell cycle arrest and to convert supercoiled DNA to relaxed and linear forms in vitro. The mutations in mutA81 and mutA221 disrupted holotoxin formation. The positions of the amino acid substitutions were mapped in the Haemophilus ducreyi Cdt crystal structure providing some insight into structure and function.
Unconventional distribution of facies in a continental rift basin: the Pliocene–Pleistocene Mangas Basin, south‐western New Mexico, USA
Authors: MACK GREG H. , STOUT DEANNA M. 
Published: October 2005

AbstractThe Pliocene–Early Pleistocene Mangas Basin in SW New Mexico, USA, was a N–NW‐trending full graben that changed southward to an eastward‐tilted half graben. Unlike the facies distribution predicted in existing models, the half‐graben part of the Mangas Basin was characterized by broad alluvial fans derived from the footwall scarp, smaller hangingwall‐derived alluvial fans, and a shallow, closed lake (Lake Buckhorn) that locally lapped onto the hangingwall hills. The distribution of facies within the full‐graben part of the Mangas Basin was also unlike that predicted in current models, primarily because of a broad belt of alluvial‐fan sediment derived from the eastern footwall scarp and a narrow belt of axial‐fluvial sediment adjacent to the western footwall scarp. The distribution of facies in the Mangas Basin does not appear to have been controlled by the eastward tilt of the floor of the half graben or ‘see‐saw’ motion of the floor of the full graben, as predicted by existing models, but rather by the large size of the alluvial fans on the eastern side of the basin. These fans were derived from large, high‐relief catchments on the footwall scarp of the Mogollon Mountains, the uplift of which began during Early Miocene. This example illustrates how earlier uplift and drainage development in a mountain range may influence facies distribution in a younger extensional basin.
Calibration of modelled mixing patterns in loess grain‐size distributions: an example from the north‐eastern margin of the Tibetan Plateau, China
Authors: VRIEND MIRJAM , PRINS MAARTEN A. 
Published: October 2005

AbstractGenetically meaningful decomposition (unmixing) of sediment grain‐size distributions is accomplished with the end‐member modelling algorithm. Unmixing of the loess grain‐size distributions of a Late Quaternary loess–palaeosol succession from the north‐eastern Tibetan Plateau indicates that the loess is a mixture of three end‐members representing very fine sandy, coarse silty and medium silty loess. The unmixing approach potentially enables the unravelling of sediment fluxes from multiple dust sources, opening the way to significant advances in palaeoclimatic reconstructions from loess grain‐size distribution data. However, as laser‐diffraction size analysis is a volume‐based technique, the proportional contributions of the modelled end‐members might deviate (significantly) from weight proportions. Hence, calibration of the end‐member volume proportions to weight proportions must be established before one can calculate the source‐specific dust fluxes. This paper reports the findings of a sediment‐mixing experiment which enables calibration of the modelled mixing patterns established for the Tibetan loess–palaeosol succession.
Supplemental 80% oxygen does not attenuate post‐operative nausea and vomiting after breast surgery
Authors: Purhonen S. , Niskanen M. , Wüstefeld M. , Hirvonen E. , Hynynen M. 
Published: October 2005

Background:  Although supplemental oxygen has been shown to be as effective as ondansetron in the prevention of post‐operative nausea and vomiting (PONV) in one study in abdominal surgery patients, the antiemetic efficacy of supplemental oxygen is controversial on the basis of studies with other patients. We compared the efficacy of 80% and 30% oxygen in decreasing PONV in breast surgery. Ondansetron was used as an active control.Methods:  Ninety patients were given a standardized sevoflurane anesthetic. They were randomly assigned to three groups: 30% oxygen in nitrogen and saline 2 ml intravenously (i.v.) at the end of surgery (group 30); 80% oxygen in nitrogen and saline 2 ml (group 80); and 30% oxygen in nitrogen and ondansetron 4 mg (group O). Oxygen was administered during surgery and up to 2 h after surgery.Results:  The incidence of total response (no retching or vomiting, no nausea) during the first 24 post‐operative hours was not different between group 80 (17%) and group 30 (11%) but was higher in group O (43%) than in group 30 (P < 0.05). Compared with group O, patients in group 80 experienced more vomiting during the study period 0–24 h (66% vs. 32%; P < 0.05) and more nausea during the period 6–24 h (72% vs. 39%; P < 0.05). There was no difference between the groups in their risk for PONV, pain scores, opioid consumption, or patient satisfaction.Conclusions:  In this study, supplemental 80% oxygen administration failed to decrease PONV in breast surgery.
Significance of working conditions on burnout  in anesthetists
Authors: Lederer W. , Kinzl J. F. , Trefalt E. , Traweger C. , Benzer A. 
Published: October 2005

Background:  The influence of working conditions on the development of burnout syndrome was assessed in anesthetists working at a university hospital.Methods:  Self‐reporting questionnaires were used to assess physical health and emotional well‐being (Health and Stress Profile), burnout syndrome (Maslach Burnout Inventory) and working conditions (Instrument for Stress‐Oriented Task Analysis) in anesthetists.Results:  Twenty‐three anesthetists (25.8%) appeared to be at risk for burnout, and three anesthetists (3.4%) had already developed full‐blown burnout syndrome. Anesthetists at risk for burnout more frequently suffered from limited complexity of work (P = 0.001), lacking individual time control (P = 0.004), lack of participation possibilities (P = 0.012), and had more physical complaints (P = 0.017) and greater job dissatisfaction (P = 0.002) than did their colleagues with no burnout symptoms.Conclusion:  Job conditions providing little opportunity to influence work pace and participation contribute to the development of burnout syndrome. Communication and contact with colleagues appear to be an important preventive regulative.
Unique genomic configuration revealed by microsatellite DNA in polyploid dogroses, Rosa sect. Caninae
Authors: Nybom H. , Esselink G. D. , Werlemark G. , Leus L. , Vosman B. 
Published: October 2005

Abstract
An allopolyploid complex with high genomic integrity has been studied. Dogroses transmit only seven chromosomes (from seven bivalents) through the pollen, whereas 21, 28 or 35 chromosomes (from seven bivalents and 14, 21 or 28 univalents) come from the egg cells. Seedlings derived from two interspecific crosses were analysed with flow cytometry and molecular markers to determine ploidy level, mode of reproduction and genomic constitution. Evidence was obtained for the formation of unreduced male and female gametes, which can take part in fertilization (producing seedlings with higher ploidy than the parental plants) or in apomictic reproduction. Random amplified polymorphic DNA (RAPD) and microsatellite analyses indicated that three seedlings (5%) were derived through apomixis, whereas the other 49 were hybrids. Bivalent formation appears to involve chromosomes that consistently share the same microsatellite alleles. Allele-sharing between the maternally transmitted and highly conserved univalent-forming chromosomes reflected the taxonomic distance between different genotypes. The frequently recombining bivalent-forming chromosomes were taxonomically less informative.
The Impact of Physiological Demands on Foraging Decisions under Predation Risk: A Test with the Whelk Acanthina monodon
Authors: Soto Rubén E. , Castilla Juan C. , Bozinovic Francisco 
Published: October 2005

AbstractWe study whether and how physiological demands affect foraging decisions under predation risk, by evaluating the effect of starvation on the rate of food consumption and prey‐size preferences and the potential trade‐off between starvation and predation risk on foraging behavior in the whelk Acanthina monodon, a gastropod inhabiting the intertidal rocky shores of central Chile. These whelks appear to adjust their foraging strategy to physiological (nutritional) demand and predation risk. Starvation reduced the effect of predation risk on the rate of food consumption by A. monodon. Thus, in the absence of the predator sea star, the rate of food consumption by starved and satiated whelks was similar. When a predator was present, starved whelks fed faster than satiated whelks. Our results indicate that foraging behaviour represents an integrated and hierarchical response to environmental conditions and the physiological conditions of the forager.
Limits to Male Copulation Frequency: Sexual Cannibalism and Sterility in St Andrew's Cross Spiders (Araneae, Araneidae)
Authors: Herberstein M. E. , Gaskett A. C. , Schneider J. M. , Vella N. G. F. , Elgar M. A. 
Published: October 2005

AbstractSexual cannibalism is common among orb‐web spiders and may limit male copulation frequency. Each copulation by male St Andrew's Cross spiders (Argiope keyserlingi) involves the transfer of sperm from one pedipalp only. Almost half of the males survive their first copulation, but all of the surviving males are cannibalized when they copulate with the other pedipalp. We investigated why males cannot copulate more than twice. Experimentally fatigued males were not cannibalized more frequently than control males. Experimental removal of one pedipalp in virgin males did not increase cannibalism during their first copulation, but the surviving males were unable to copulate with a subsequent female, suggesting they cannot use a pedipalp more than once. Un‐manipulated males always inserted their unused pedipalp during their second copulation. Sperm counts from males preserved immediately after copulation and from males maintained for an additional 3 wk show that used pedipalps are not replenished over such a period.
Cooperative Breeding and Group Structure in the Lake Tanganyika Cichlid Neolamprologus savoryi
Authors: Heg Dik , Bachar Zina , Taborsky Michael 
Published: October 2005

AbstractAs yet, cooperative breeding has been described only for some fish species. However, evidence is accumulating that it is widespread among Lake Tanganyika cichlids. We studied the cooperative breeding system of the substrate breeding cichlid Neolamprologus savoryi. Breeding groups typically consisted of a large breeding male with one to four breeding females and three to 33 helpers (mean group size: 14.3 members). Group size was significantly related to breeding male and female body sizes, and larger males had more breeding females and larger sized male helpers. The size of the largest female in the group was positively related to the number and sizes of secondary breeding females and female helpers. In case of multiple breeding females, these females usually divided the group's territory into sub‐territories, each with its own helpers (subgroups). Interspersed between groups, independent fish were detected defending an individual shelter (4.4% of all fish). In 9% of the groups no breeding female was present. All group members participated in territory defence and maintenance, and showed submissive behaviours to larger group members. As expected, the level of between‐subgroup conflicts was high compared with the level of within‐subgroup conflicts. We compare these results with data available from other cooperatively breeding fishes.
Individual Consistency in Parental Effort Across Multiple Stages of Care in the House Sparrow, Passer domesticus
Authors: Kopisch Amy D. , Schwagmeyer P. L. , Mock Douglas W. 
Published: October 2005

AbstractIn many avian species in which biparental care is provided to offspring, substantial variation exists within members of each sex in the level of effort contributed to various forms of parental care. Questions remain as to whether individuals that contribute more toward one parental activity also contribute more toward other activities in which they participate. We examined the contributions of male and female house sparrows (Passer domesticus) to three forms of parental care: incubation, nestling provisioning, and nest defense, and compared the investments made by individuals at each stage of care relative to other same‐sexed parents. In both males and females, nestling feeding rates were positively associated with time spent incubating, but no relationships were found between measures of nestling feeding and nest defense. The predictability of an individual's feeding behavior based on earlier incubation efforts may make incubation a good stage for individuals to evaluate the parental abilities of their partners.
Inflammatory bowel disease in Iran: A review of 457 cases
Authors: AGHAZADEH RAHIM , ZALI MOHAMMAD REZA , BAHARI ALI , AMIN KAMYAR , GHAHGHAIE FARZIN , FIROUZI FARZAD 
Published: October 2005

AbstractBackground and Aims: Inflammatory bowel disease (IBD) was believed to be infrequent in Iran; however, unofficial reports have confessed the continuing rise in IBD in our country.Methods: Demographic and clinical features, extraintestinal manifestations, extension of disease and complications of 401 patients with ulcerative colitis (UC), 47 with Crohn's disease (CD), and nine with indeterminatn colitis (IC) were assessed retrospectively. The exact course of physicians’ visits of 250 IBD patient was asked through face‐to‐face interview.Results: Mean age at diagnosis was 31.9 years in UC and 30.5 years in CD patients. The male to female ratio was 0.8 for UC and 1.3 for CD. The percentage of CD and UC patients who were non‐smokers was 82.9 and 84.5%, respectively. Patients with UC presented with rectal bleeding (41.9%), whereas those with CD complained of abdominal pain (46.9%). Among UC patients, proctosigmoid was affected in 51.9%. Colorectal cancer was diagnosed in two patients. The mean lag time between the onset of symptoms and definite diagnosis was 13.9 and 17.7 months for UC and CD patients, respectively. A total of 32.4% of patients with IBD had at least one of the five major extra‐intestinal diseases.Conclusion: The demographic and clinical picture of IBD is more or less the same as that of other developing countries; however, the rarity of CD in Iran is noted. Although the true epidemiologic profile of IBD in Iran is still unknown, it is not as rare as previously thought, and it seems as if gradual adoption of a Western lifestyle may be associated with the continuing rise in IBD.© 2005 Blackwell Publishing Asia Pty Ltd