bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of mark–recapture models to estimate the abundance of a humpback whale feeding aggregation in Southeast Alaska
Authors: Straley Janice M. , Quinn II Terrance J. , Gabriele Christine M.
Published: July 2008

Aim The aim of this study was to use photographs of the unique pattern on the ventral surface of the flukes to estimate the abundance of humpback whales (Megaptera novaeangliae) in a discrete feeding aggregation in northern Southeast Alaska.

Location The study was located in northern Southeast Alaska, USA, in the eastern North Pacific Ocean.

Methods This study evaluated mark–recapture models, ranging from the simpler models (pooled and stratified, closed Petersen estimators) to more complex multi‐strata models (closed Darroch and open Hilborn). The Akaike Information Criterion, corrected (AICc) was used as a model comparison statistic.

Results Our best estimate of whale abundance in northern Southeast Alaska in 2000 is 961 whales [95% confidence interval (657, 1076)]. This estimate comes from the Hilborn open, multi‐strata approach with constant migration over time, time‐dependent capture probabilities by area, and a fixed survival rate of 0.98. The simpler models were problematic owing to several aspects of whale behaviour, including that (1) the whales did not mix randomly throughout the study area, (2) some whales emigrated temporarily outside the study area and were not available for capture, and (3) whales were not equally identifiable because they did not behave in the same way when they showed their flukes upon diving. This led to heterogeneity in capture probability and a bias in the estimates. The more complex models stratified by area, and using migration movements among areas, compensated for some of these issues when estimating population size.

Main conclusions We believe that the Hilborn open, multi‐strata model produced the best estimate because: (1) it incorporated the best information about survival, (2) it used detailed information about the various release groups, (3) the analysis provided an integrated environment in which parameters such as migration and capture probabilities are shared, (4) the three strata encompassed a large portion of the areas used by whales, and (5) the Hilborn model selected was superior in terms of model selection criteria and biological realism. These data provide valuable insights into the numbers and movements of humpback whales in three areas of Southeast Alaska.
Assemblage‐level responses of phyllostomid bats to tropical forest fragmentation: land‐bridge islands as a model system
Authors: Meyer Christoph F. J. , Kalko Elisabeth K. V.
Published: July 2008

Aim  Working within a system of high structural contrast between fragments and the surrounding matrix, we assessed patterns of species loss and changes in species composition of phyllostomid bats on artificial land‐bridge islands relative to mainland assemblages, and evaluated the responses of bats to forest edges. We further examined the relative influence of local‐scale characteristics (e.g. vegetation structure, island area) versus landscape attributes (e.g. forest cover, patch density) and the importance of spatial scale in determining phyllostomid species richness and composition on islands.

Location  Islands in Gatún Lake and adjacent mainland peninsulas in the Barro Colorado Nature Monument, Panama.

Methods  Bats were sampled over a 2‐year period on 11 islands as well as at forest‐edge and interior sites on adjacent mainland, resulting in > 8400 captures.

Results  The islands harboured a less diverse and structurally simplified phyllostomid bat fauna. Islands far from the mainland were especially species‐poor. This decline in species richness was associated with compositional shifts towards assemblages strongly dominated by frugivores with good dispersal abilities. Members of other ensembles, most importantly gleaning animalivores, were much less common or absent. Although overall species composition was not significantly altered, species richness at continuous forest‐edge sites was significantly lower compared with that at interior sites. Distance from the mainland and amount of forest cover in the landscape were the best predictors of species richness and assemblage composition. Responses were scale‐dependent. At the local scale, species richness was independent of island area but was correlated positively with distance from the mainland. In contrast, area effects became more important at larger spatial scales, suggesting that many species use multiple fragments.

Main conclusions  Our results underline the conservation value of small habitat remnants, which, even when embedded in a hostile matrix, can support a relatively diverse bat fauna, provided that there is a low degree of patch isolation and spatial proximity to larger tracts of continuous forest. Although the results at the assemblage level were inconclusive, we demonstrate that certain bat species and ensembles, particularly gleaning animalivores, exhibit high edge‐sensitivity. Our results point to habitat loss rather than changes in landscape configuration as the main process after isolation underlying phyllostomid bat responses, suggesting that conservation efforts should focus on habitat preservation instead of trying to minimize fragmentation per se at the expense of habitat amount.
Biodiversity of soft‐sediment benthic communities from Italian transitional waters
Authors: Munari Cristina , Mistri Michele
Published: July 2008

Aim  For conservation purposes, it is important to understand the forces that shape biodiversity in transitional waters (TWs) and to evaluate the effects of small‐scale latitudinal changes. To this end, we analysed data on soft‐sediment macroinvertebrates from nine Italian TWs in order to (1) investigate the structure and distribution of the benthic fauna and their relationships with environmental and geographical variables, and (2) examine species richness and β‐diversity at various spatial scales.

Location  European Transition Waters Ecoregion 6.

Methods  Using a data set collected along a 7° latitudinal cline between 45°28′ N and 39°56′ N, we used Spearman’s rank correlation analysis to evaluate the relationships between species richness and both environmental and geographical variables, and linear regression analysis to show the relationships between α‐, β‐ and γ‐diversity. Three measures were used to assess β‐diversity: Whittaker’s βW, and two similarity indices, namely the Bray‐Curtis similarity index and Δs. Using multivariate analyses, we determined the similarity in composition of the benthic community between sites and compared the biotic ordination with abiotic (geographical and environmental) characteristics.

Results  Two hundred and sixty‐eight species were recorded from 46 sites. Of these, 53.4% were restricted to one TW. Annelida was the dominant taxonomic group, followed by Crustacea and Mollusca. The α‐diversity was highly variable (5–87 species) and was correlated with latitude. The γ‐diversity, measured at the TW scale, was correlated significantly with α‐diversity. The β‐diversity increased with spatial scale and habitat heterogeneity. In the community pattern identified by multivariate analysis, TWs were segregated by latitude and biogeography, and this reflected different climatic conditions.

Main conclusions  We found that α‐diversity increased when moving from higher to lower latitudes, and that it depended on both regional and local factors. In addition, we detected latitudinal variations in the extent of regional influence on local species richness. The observed distribution pattern of TW faunas depended mostly on climate type. We suggest that the distribution of annelidan species could be used as a proxy for assessing general community patterns for Italian TWs.
Distribution patterns of land snails in Ugandan rain forests support the existence of Pleistocene forest refugia
Authors: Wronski Torsten , Hausdorf Bernhard
Published: July 2008

Aim We investigated whether the biogeographical patterns expected if the East African fauna was affected by cycles of contraction to refugia and expansion of ranges, as has been previously hypothesized, can be found in the land snail fauna of rain forests in Uganda.

Location The Albertine Rift region and the Lake Victoria forest belt in Uganda.

Methods Snails and slugs were sampled in 60 plots in 13 rain forests, and small species were extracted from 5‐L leaf litter samples. Relative species richness was calculated by rarefaction. The influence of putative determinants of species richness was examined by bivariate correlation and multiple regression. Clustering and nestedness were tested by Monte Carlo simulations with a null model that considers the range size distribution, the species richness distribution of the forests, and the spatial autocorrelation of the occurrences of each species. Biotic elements were determined by model‐based Gaussian clustering.

Results A total of 169 land snail species were recorded from 13 Ugandan rain forests. Relative species richness increases with rainfall and altitude, and decreases with evaporation and distance from the putative East Congolian refugia. Mean annual rainfall and distance from the putative East Congolian refugia were included in the best multiple regression model. The distribution areas of the Ugandan land snails are significantly clustered. Two montane, two lowland and a northern biotic element were found. The mean range extension increases with increasing distance from the putative East Congolian refugia. Moreover, the ranges of the Ugandan land snails are significantly nested. The centre of the sets of nested subsets is in the Virunga Mountains, close to the putative East Congolian refugia.

Main conclusions The decrease of diversity with increasing distance from the putative East Congolian refugia, the clustering and nestedness of ranges, and the range size increase with increasing distance from the refugia indicate that the East African land snail fauna was affected by cycles of contraction to refugia and expansion of ranges. The significant clustering and nestedness cannot be explained by current environmental conditions. Given the environmental history, it can be supposed that the lowland elements expanded post‐glacially, whereas the ranges of the montane species are probably currently contracting.
Phylogeography of the pallid kangaroo mouse,Microdipodops pallidus: a sand‐obligate endemic of the Great Basin, western North America
Authors: Hafner John C. , Upham Nathan S. , Reddington Emily , Torres Candice W.
Published: July 2008

Aim Kangaroo mice, genusMicrodipodopsMerriam, are endemic to the Great Basin and include two species:M. pallidusMerriam andM. megacephalusMerriam. The pallid kangaroo mouse,M. pallidus, is a sand‐obligate desert rodent. Our principal intent is to identify its current geographical distribution and to formulate a phylogeographical hypothesis for this taxon. In addition, we test for orientation patterns in haplotype sharing for evidence of past episodes of movement and gene flow.

Location The Great Basin Desert region of western North America, especially the sandy habitats of the Lahontan Trough and those in south‐central Nevada.

Methods Mitochondrial DNA sequence data from portions of three genes (16S ribosomal RNA, cytochromeb, and transfer RNA for glutamic acid) were obtained from 98 individuals ofM. pallidusrepresenting 27 general localities sampled throughout its geographical range. Molecular sequence data were analysed using neighbour‐joining, maximum‐parsimony, maximum‐likelihood and Bayesian methods of phylogenetic inference. Directional analysis of phylogeographical patterns, a novel method, was used to examine angular measurements of haplotype sharing between pairs of localities to detect and quantify historical events pertaining to movement patterns and gene flow.

Results Collecting activities showed thatM. pallidusis a rather rare rodent (mean trapping success was 2.88%), and its distribution has changed little from that determined three‐quarters of a century ago. Two principal phylogroups, distributed as eastern and western moieties, are evident from the phylogenetic analyses (mean sequence divergence for cytochromebisc. 8%). The western clade shows little phylogenetic structure and seems to represent a large polytomy. In the eastern clade, however, three subgroups are recognized. Nine of the 42 unique composite haplotypes are present at two or more localities and are used for the orientation analyses. Axial data from haplotype sharing between pairwise localities show significant, non‐random angular patterns: a north‐west to south‐east orientation in the western clade, and a north‐east to south‐west directional pattern in the eastern clade.

Main conclusions The geographical range ofM. pallidusseems to be remarkably stable in historical times and does not show a northward (or elevationally upward) movement trend, as has been reported for some other kinds of organism in response to global climate change. The eastern and western clades are likely to represent morphologically cryptic species. Estimated times of divergence of the principal clades ofM. pallidus(4.38 Ma) and betweenM. pallidusandM. megacephalus(8.1 Ma; data from a related study) indicate that kangaroo mice diverged much earlier than thought previously. The phylogeographical patterns described here may serve as a model for other sand‐obligate members of the Great Basin Desert biota.
Red herring or low illumination? The peninsula effect revisited
Authors: Jenkins David G. , Rinne Debra
Published: July 2008

Aim The peninsula effect is the prediction that the number of species declines from a peninsula's base to its tip. We evaluated evidence for and against the peninsula effect, and conducted a field study designed to test alternative hypotheses for that effect.

Location The Florida peninsula, USA.

Methods First, we critically reviewed the accumulated literature on peninsula effects; second, we sampled microcrustaceans in palustrine wetlands on the ridges of peninsular Florida. Site selection in our field study accounted for historical effects and partially controlled for habitat effects. Statistical analyses further accounted for habitat effects, leaving peninsular geometry as the remaining causative mechanism for residual variation in species richness regression analyses.

Results Our literature review found mixed evidence (49% of cases) for a peninsula effect. However, most study designs did not control for alternative hypotheses, most comparisons of alternative hypotheses were qualitative, and most studies focused on vertebrate animals. Our field study found that freshwater microcrustaceans inhabiting isolated wetlands on Florida’s peninsular ridges do not exhibit a peninsula effect. Essentially, no variation in microcrustacean species richness could be attributed to peninsular geometry, but 82.5% of variation in species richness was attributed to habitat and sampling effort.

Main conclusions Although our research results support the ‘red herring’ label for the peninsula effect, our literature review leads us to argue that more illumination (in the form of study design and quantitative analysis) is needed if mechanisms causing the peninsula effect hypothesis are to be resolved. Future studies of peninsula effects need to control for alternative causative hypotheses (geometry, habitat or history) in study design, and compare quantitatively the effects of hypothesized mechanisms on peninsular diversity patterns. Additionally, studies of taxa other than vertebrate animals need to be conducted for generality. Our study may serve as an example of such an approach.
Definition of grassland biomes from phytoliths in West Africa
Authors: Bremond Laurent , Alexandre Anne , Peyron Odile , Guiot Joël
Published: July 2008

Aim  In order to enhance the effectiveness of comparisons between modelled and empirical data for present and past vegetation, it is important to improve the characterization of tropical grass‐dominated biomes reconstructed from fossil tracers. This study presents a method for assigning phytolith assemblages to tropical grass‐dominated biomes, with the objective of offering a new tool for combining pollen and phytolith data in the reconstruction of tropical biomes.

Location  The West African latitudinal transect studied here extends from 12° N (southern Senegal) to 23° N (southern Mauritania), passing through the Guinean, Sudanian, Sahelian and Saharan bioclimatic zones.

Methods  Modern phytolith assemblages were extracted from 59 soil surface samples taken throughout the study area and allocated, a priori, to three current biomes: (1) desert C4 grassland, (2) short grass savanna, and (3) tall grass savanna. Five out of nine phytolith types identified were used as predictors in a discriminant analysis (with calibration and validation steps) for assigning phytolith assemblages to biomes. In addition, 74 modern pollen spectra from the West African transect, acquired from the African Pollen Database (http://medias.obs‐mip.fr/apd), were processed by the biomization method. This mathematical procedure involves assigning palynological taxa to one or more plant functional types, which represent broad classes of plants. The plant functional types, in turn, are combined to define biomes following a specific set of algorithms and rules. The resulting maps of the phytolith biomes thus derived were compared with maps of pollen biomes and of contemporary ecosystem classes.

Results  In the calibration and validation steps, 91.5% and up to 83%, respectively, of the phytolith samples were assigned to the correct biome. The short grass savanna and tall grass savanna biomes were assigned with similar accuracy by both the phytolith and pollen biomization methods, but the phytolith method gave substantially superior results for the desert C4 grassland biome, providing seven out of seven correct assignments, compared with just one out of four by pollen biomization. Comparisons between an existing ecosystem map and the maps created from phytolith estimation showed close correspondence for desert C4 grassland, short grass savanna and tall grass savanna, the latter providing correct assignments in 88, 62 and 91% of cases, respectively.

Main conclusions  The phytolith discriminant analysis method presented here accurately estimates three C4 grass‐dominated biomes that are widespread in West Africa. Complementarities between the phytolith method and pollen biomization are highlighted. Combining complementary phytolith and pollen data would provide more accurate assignments of C4 grass‐dominated biomes than pollen biomization alone.
Does the varied use of NSAIDs explain the differences in the risk of myocardial infarction?
Authors: Van Staa T.‐P. , Rietbrock S. , Setakis E. , Leufkens H. G. M.
Published: July 2008

Objective.  To investigate the risk of myocardial infarction (MI) with diclofenac, ibuprofen and naproxen, taking into account the exposure patterns.

Design.  Retrospective cohort study using the General Practice Research Database.

Setting.  UK primary care.

Subjects.  Patients aged 40+ years prescribed a traditional nonsteroidal anti‐inflammatory drug (NSAID). The control cohort was frequency matched by disease risk score.

Intervention.  Observational comparisons of MI rates.

Results.  The study included 729294 NSAID users and 443047 controls. The relative rate (RR) for MI increased with cumulative and daily dose (RR = 1.05 with 0–4 prior prescriptions and RR = 1.49 with 30+; RR = 1.05 with daily dose of <1200 mg ibuprofen and RR = 1.96 with dose of ≥2400 mg per day; for diclofenac, the RR was 1.13 with <150 mg per day and 2.03 with ≥300 mg per day). Diclofenac users had higher risks of MI (RR = 1.21) than ibuprofen (RR = 1.04) or naproxen (RR = 1.03) users, but exposure varied between these drugs. Taking into account these exposure differences, it was found that the risk of MI was comparable in current and past long‐term users. The patterns of hazard rates (i.e. absolute risks) of MI were similar in patients using ibuprofen, diclofenac or naproxen with similar history of NSAID use. There was no statistical difference between ibuprofen, diclofenac and ibuprofen in the linear trends for cumulative dose or daily dose.

Conclusions.  Long‐term users of traditional NSAIDs have an increased risk of MI that is probably explained by the underlying disease severity. Most of the differences in MI risk between diclofenac, ibuprofen or naproxen may be explained by their varied use.
Developing more positive attitudes towards mental health nursing in undergraduate students: part 1 – does more theory help?
Authors: HAPPELL B. , ROBINS A. , GOUGH K.
Published: July 2008

Negative attitudes towards mental illness and the mental health nursing profession have deterred many undergraduate nursing students from considering this area as an attractive career option. Positive clinical experience has been identified as the most important factor in producing more favourable attitudes. While the quantity of theory is identified as important, its impact on attitudes has not been examined through research. This study compared two groups of students undertaking different numbers of theoretical and clinical hours in mental health nursing to determine if this increase has an impact on nursing students' attitudes. Anonymous questionnaires were distributed to the total population of students following completion of the theoretical component of the programme but prior to clinical experience. The questionnaire was designed to assess: (1) nursing student's preparedness for and attitudes towards the mental health field; (2) consumers of mental health services; and (3) the students' career preferences. This first paper in a two‐part series examines the impact of theoretical hours and suggests that while other attitudes are fairly similar between the two groups, the group exposed to more theory exhibited significantly more positive attitudes towards psychiatric nursing as a career.
The experiences and perceived changes of Chinese ex‐mental patients attending a holistic psychiatric rehabilitation programme: a qualitative study
Authors: LUK A. L. , SHEK D.
Published: July 2008

The paper reports a study on the subjective experiences and perceived personal changes of Chinese ex‐mental patients attending a psychiatric holistic rehabilitation programme. The programme adopted a self‐help group approach in which holistic aspects of physical, psycho‐social and spiritual needs are emphasized. There are different rehabilitation programmes for chronic mental patients. However, spiritual element is not consciously included in most of these programmes. Furthermore, few studies document the changes of participants attending psychiatric rehabilitation adopting self‐help and holistic care principles. A qualitative approach using an in‐depth interview was adopted. A total of 20 members from the programme, which was about one‐sixth of all the regular group members were recruited. All interviews were audiotaped and transcribed. Data were coded, categorized and developed to different themes using content analysis. Totally, there were 52 themes developed from the data. However, only 13 themes on experiences in the group and nine themes on the perceived personal changes were reported. By attending the programme, participants had positive feelings and gained many positive learning opportunities when interacting with peers. Interacting with group counsellors was also very beneficial to them. Though there were only some improvements physically, there were clear perceived positive changes in the psychological, social and spiritual dimensions. These findings are consistent with those found in the quantitative measures reported previously. The subjective experiences of the participants were positive and they perceived positive personal changes after joining the group. The findings support the effectiveness of the long‐term nature of self‐help group. Furthermore, the holistic programme helps members rediscover meaning and purpose of life and the religious practices in the group can be regarded to be a protective factor to stress not only to those believers but also to the non‐believers.
Perceived sleep quality of psychiatric patients
Authors: NIET DE G. J. (GERRIT) , TIEMENS B. G. (BEA) , LENDEMEIJER H. H. G. M. (BERT) , HUTSCHEMAEKERS G. J. M. (GIEL)
Published: July 2008

This paper aims at acquiring knowledge about the quality of sleep of adult and elderly psychiatric patients who receive clinical or outpatient nursing care, and identifying key factors in perceiving a sleep problem. To do so, a sample of 1699 psychiatric patients were asked whether they perceived a sleep problem and were invited to fill in the Pittsburgh Sleep Quality Index (PSQI) and additional questions. Five hundred and sixty (33%) questionnaires were returned. As a result, we find that 36% of the patients perceived a sleep problem, while the PSQI assessed 66% of the sample as being ‘bad sleepers’. Forty‐nine per cent of the respondents used sleep medication one or more times a week. Five items of the PSQI were shown to be predictors of a perceived sleep problem. Four of these are insomnia symptoms, while the fifth is the use of sleep medication. Moreover, the patients who used sleep medication most scored significantly worse on all PSQI components than patients who used sleep medication less than once a week. In conclusion, many psychiatric patients perceive a sleep problem and all nurses could be confronted not only with the night‐time consequences of this, but also with daytime consequences. Therefore, sleep problems must not be viewed as an isolated problem but must be seen in relation with social functioning.
Caregivers' reflections on their interactions with adult people with learning disabilities
Authors: ANTONSSON H. , GRANEHEIM U. H. , LUNDSTRÖM M. , ÅSTRÖM S.
Published: July 2008

People with learning disabilities and their professional carers often have difficulty interacting. The aim of this study was to illuminate carers' reflections on their interactions with adult people with learning disabilities. In a previous study, interactions between 16 carers and 11 residents with learning disabilities were recorded on video. In this study, stimulated recall interviews about the interactions were carried out with all the carers. The text was analysed using qualitative content analysis. The findings indicate that the carers reflected on both successful and unsuccessful interaction. Examples of successful interaction included understanding cues, satisfying needs, and managing challenging behaviours, and the carers reflected on the influences that successful interaction had on security, confidence, and satisfaction among the residents. Examples of unsuccessful interaction included failing to understand cues, failing to satisfy needs and failing to manage challenging behaviours, and the carers reflected on the consequences of such interaction, which included irritation, aggression and violence among the residents. Our findings have implications for interventions aimed at strengthening the competence of carers and developing strategies for managing challenging behaviour, in order to ensure high‐quality care and a good working climate.
Do ‘no‐suicide’ contracts work?
Authors: MCMYLER C. , PRYJMACHUK S.
Published: July 2008

Suicide is the main cause of premature death in mental health service users, and the prevention of suicide is a major, global concern. An intervention designed to address this concern is the ‘no‐suicide’ contract (NSC) – an agreement, usually written, between a mental health service user and clinician, whereby the service user pledges not to harm himself or herself. Following a review of the literature on NSCs, this paper argues that there is a lack of quantitative evidence to support such contracts as clinically effective tools and that there is strong opposition to the tool, from both service users and nurses. Moreover, important ethical and conceptual issues in the use of such contracts have been identified, including the potential for coercion from the clinician for their own protection and the ethical implications of restricting a service user's choices when they may be already struggling for control. In light of these findings, the paper discusses alternative interventions aimed at preventing self‐harm and suicide. Although a number of other interventions are available to clinicians, further research is required to test the effectiveness of these as viable alternatives to the NSC.
Expression of MDR1, MRP2 and BCRP mRNA in tissues of turkeys
Authors: HARITOVA A. M. , SCHRICKX J. , LASHEV L. D. , FINK‐GREMMELS J.
Published: July 2008

MDR1, MRP2 and BCRP are members of the superfamily of ABC membrane transporters that export a large variety of structurally diverse substances out of the cell, hence being an integral part of various biological barriers. Here we report for the first time the tissue distribution of these ABC efflux transporters in the gastrointestinal tract (crop, proventriculus, duodenum, proximal and distal jejunum, ileum, caecum, colon) as well as in liver, kidney, lung, brain, adrenal gland, ovaries, oviduct and testes in BUT9 turkeys. MDR1 and BCRP mRNA expression was detected in all tissue samples, and the highest levels were measured in the small intestines. The tissue distribution of MRP2 mRNA was less consistent and some tissues seemed to lack any significant expression. Moreover, in consideration of previous findings suggesting that fluoroquinolones are substrates and modulators of ABC transporters, the effect of orally administered danofloxacin mesylate on the levels of MDR1, MRP2 and BCRP mRNA expression was investigated. Danofloxacin treatment resulted in a significant up‐regulation of the measured transporters at the transcriptional level in the upper part of gastro‐intestinal tract, liver and kidneys as well as in barrier‐protected organs, such as the brain. However, despite this significant increase in the transcription levels, the pharmacokinetic parameters after repeated application of danofloxacin mesylate were not significantly altered.
Recombination of synthetic oligonucleotides with prokaryotic chromosomes: substrate requirements of the Escherichia coli/λRed and Sulfolobus acidocaldarius recombination systems
Authors: Grogan Dennis W. , Stengel Kristy R.
Published: July 2008

In order to reveal functional properties of recombination involving short ssDNAs in hyperthermophilic archaea, we evaluated oligonucleotide‐mediated transformation (OMT) in Sulfolobus acidocaldarius and Escherichia coli as a function of the molecular properties of the ssDNA substrates. Unmodified ssDNAs as short as 20–22 nt yielded recombinants in both organisms, as did longer DNAs forming as few as 2–5 base pairs on one side of the genomic mutation. The two OMT systems showed similar responses to certain end modifications of the oligonucleotides, but E. coli was found to require a 5′ phosphate on 5′‐limited ssDNA whereas this requirement was not evident in S. acidocaldarius. The ability of both E. coli and S. acidocaldarius to incorporate short, mismatched ssDNAs into their genomes raises questions about the biological significance of this capability, including its phylogenetic distribution among microorganisms and its impact on genome stability. These questions seem particularly relevant for S. acidocaldarius, as this archaeon has natural competence for OMT, encodes no MutSL homologues and thrives under environmental conditions that accelerate DNA decomposition.
The periplasmic regulator ExoR inhibits ExoS/ChvI two‐component signalling in Sinorhizobium meliloti
Authors: Chen Esther J. , Sabio Erich A. , Long Sharon R.
Published: July 2008

Sinorhizobium meliloti requires ExoS/ChvI two‐component signalling to establish a nitrogen‐fixing symbiosis with legume hosts. The importance of ExoS/ChvI signalling in microbe–host interactions is underscored by the requirement of ExoS/ChvI orthologues for virulence of the related α‐proteobacteria Agrobacterium tumefaciens and Brucella abortus. In S. meliloti, ExoS/ChvI is a key regulator of gene expression for exopolysaccharide synthesis, biofilm formation, motility, nutrient utilization and free‐living viability. Previously, we showed that the novel conserved regulator ExoR interacts genetically with both ExoS and ChvI, and localizes to the periplasm of S. meliloti. Here, we show that ExoR physically associates with ExoS and that this association is important for regulating ExoS/ChvI signalling. We have identified point mutations in the Sel1‐like repeat region of ExoR that disrupt binding to ExoS and cause a dramatic increase in ExoS/ChvI‐dependent gene expression. Furthermore, we have found that physical interaction with ExoS stabilizes the ExoR protein. Together, our results indicate that ExoR binds to ExoS in the periplasm of S. meliloti to inhibit ExoS/ChvI activity, and that ExoR represents a novel periplasmic inhibitor of two‐component signalling.
Diagenesis of plattenkalk: examples from the Solnhofen area (Upper Jurassic, southern Germany)
Authors: MUNNECKE AXEL , WESTPHAL HILDEGARD , KÖLBL‐EBERT MARTINA
Published: July 2008

The Upper Jurassic (Tithonian) plattenkalk successions in the Solnhofen/Eichstätt area consist of alternations of thin‐bedded, laminated, fine‐grained, very pure limestones (so‐called ‘flinz beds’) and softer interlayers with slightly lower carbonate contents that are also laminated and show a foliaceous weathering appearance (‘fäule beds’). These successions are world famous for their exceptionally well‐preserved fossils. In contrast to the well‐studied wealth of fossils, little is known about the origin and diagenesis of the host rock. The reason for this discrepancy might lay in the monotonous appearance of these fine‐grained mudstones that require electron microscopical examination. Study of samples from the Solnhofen–Eichstädt area implies that flinz and fäule beds have undergone differential diagenesis. The ultrastructure of the flinz beds is characterized by interlocking microspar crystals, whereas the fäule beds show smaller and less interlocking crystals. The ratios of diagenetically inert trace elements lack clear differences between the two interlayered lithologies. While most authors agree that the flinz–fäule rhythm reflects rhythmically changing environmental conditions, primary rhythms can be taken as proven only where statistically significant differences in diagenetically resistant proxies are found. The absence of clear primary differences between flinz and fäule beds, however, leaves the question of primary differences unsolved. It is concluded that diagenesis has had a strong influence on the genesis of the lithological rhythm, and that any primary rhythm underlying the diagenetically mature rhythm is less clear than generally assumed.
New insights of HLA class I association to Behçet’s disease in Portuguese patients
Authors: Bettencourt A. , Pereira C. , Carvalho L. , Carvalho C. , Patto J. V. , Bastos M. , Silva A. M. , Barros R. , Vasconcelos C. , Paiva P. , Costa L. , Costa P. P. , Mendonça D. , Correia J. , Silva B. M.
Published: July 2008

Human leukocyte antigen (HLA)‐B*51 is a well‐known genetic factor associated with Behçet’s disease (BD). To analyse the influence of HLA‐B*51 and other HLA class I alleles in BD susceptibility in a Portuguese population and its association with disease severity, we studied 78 BD patients and 208 healthy controls. The patients were classified into two severity groups as described by Gul et al. As expected, a higher frequency of HLA‐B*51 was found. The frequency of HLA‐Cw*16 alleles was significantly higher in patients. Regarding severity, HLA‐B*27 frequency was higher in the severe group compared with controls and with the mild group. Thus, HLA‐B*51 and HLA‐Cw*16 seem to confer susceptibility to BD in this patients. HLA‐B*27 may be important as a prognostic factor.
Screening for rejection in symptomatic pediatric heart transplant recipients: The sensitivity of BNP
Authors: Geiger Miwa , Harake Danielle , Halnon Nancy , Alejos Juan Carlos , Levi Daniel S.
Published: July 2008

Abstract:  As the pediatric OHT population expands, there is increasing demand for convenient, yet sensitive screening techniques to identify children with acute rejection when they present to acute care facilities. In children, symptoms of acute rejection or other causes of graft dysfunction are often non‐specific and can mimic other childhood illnesses. The aim of this study was to assess the utility of BNP as a biomarker to assist providers in clinical decision‐making when evaluating symptomatic pediatric heart transplant patients. One hundred twenty‐two urgent care and emergency room visits from 53 symptomatic pediatric OHT patients were retrospectively reviewed to evaluate the relationship between BNP levels, symptoms, and clinical diagnosis at these visits. An ROC curve was generated to determine the accuracy of BNP as a screening tool for acute rejection in this patient population. In this group of patients, a BNP value of >700 pg/mL was 100% sensitive and 92% specific for detecting allograft acute rejection (NPV of 100%). We concluded that BNP is a highly sensitive screening test for acute rejection in symptomatic pediatric heart transplant patients.
Subclinical atherosclerosis after heart and heart–lung transplantation in childhood
Authors: Dalla Pozza Robert , Urschel Simon , Bechtold Susanne , Kozlik‐Feldmann Rainer , Schmitz Christoph , Netz Heinrich
Published: July 2008

Abstract:  Children after heart transplantation are considered as at‐risk patients for extracardiac atherosclerotic complications. Noninvasive ultrasound measurement of the common carotid artery (IMT) provides valid information about the endothelial structure of the vascular system. Twenty‐two patients (17 male, mean age 12.4 ± 4.5 yr) after heart and (5.7 ± 4.5 yr) heart–lung transplantation were enrolled. The mean IMT was measured and compared with a control group (18 children, 10 male, mean age 11.8 ± 1.8 yr) and to normative data. Transplanted children had a higher IMT than controls (0.453 ± 0.003 vs. 0.424 ± 0.002 mm, p < 0.001). IMT‐SDS was increased as well (1.6 ± 0.1 vs. 0.8 ± 0, p < 0.001). Transplanted children had a higher LDL/HDL‐ratio (2.2 ± 0.2 vs. 1.2 ± 0.1, p < 0.001). Time after transplantation, age at the time of transplantation, or medical therapy did not influence the findings. We found evidence for subclinical atherosclerosis in children after heart and heart–lung transplantation. Even if single atherosclerotic risk factors could not be identified, transplanted children seem to be at risk for atherosclerosis. Our findings support the recently published statement of the AHA‐Expert panel: after heart transplantation atherosclerotic complications may occur with increased incidence. We propose the IMT‐measurement in these patients as an easy method to assess the vascular status and to guide preventive measures.
Successful arterial thrombolysis and percutaneous transluminal angioplasty for early hepatic artery thrombosis after split liver transplantation in a four‐month‐old baby
Authors: López‐Benítez R. , Schlieter M. , Hallscheidt P. J. , Radeleff B. A. , Kauffmann G. , Richter G. M. , Schmidt J. , Engelmann G.
Published: July 2008

Abstract: Early HAT is the most frequent and severe vascular complication following liver transplantation. It is one of the major causes of graft failure and mortality. Endovascular thrombolytic treatment in patients with thrombotic complications after liver transplantation is an attractive alternative to open surgery as lower morbidity and mortality rates are reported for it. PTA following transcatheter thrombolysis has been successfully used to treat HAT in adults. To the best of our knowledge, there have not been any reports of a successful transcatheter thrombolysis using interventional radiological techniques in a patient only four months old. The present report describes the successful endovascular emergency treatment of a HAT three days after DD split liver transplantation.
Experimental multivisceral xenotransplantation
Authors: Galvão Flávio Henrique Ferreira , Pompeu Eduardo , De Mello Evandro Sobroza , Da Costa Lino Costa Anderson , Mory Eduardo , Dos Santos Rafael Miyashiro , Santos Vinicius Rocha , Machado Marcel Cesar , Bacchella Telésforo
Published: July 2008

Abstract:  Background:  Organ shortage impairs the proposition of multivisceral transplantation to treat multiple organ failure. Interspecies (xeno) transplantation is a valid solution for organ shortage; however, suitable models of this advance are lacking. We describe an effective model of multivisceral xenotransplantation to study hyperacute rejection.

Methods:  Under general anesthesia, we in block recovered the distal esophagus, stomach, small bowel, colon, liver, pancreas, spleen, and kidneys from donors and implanted heterotopically in the lower abdomen of recipients. Animals were divided into four groups: I—canine donor, swine recipient (n = 6); II – swine donor, canine recipient (n = 5); III—canine donor, canine recipient (n = 4); and IV—swine donor, swine recipient (n = 5). Groups I and II comprised experimental (xenotransplantation) and III and IV control groups (allotransplantation). During the experiment, we appraised recipient evolution and graft modification by sequential biopsy up to 3 h. At this time, we killed animals for autopsy (experimental end point).

Results:  We accomplished all experiments successfully. Every grafts attained customary appearance and convenient urine output immediately after unclamp. Around 15 min after reperfusion, xenografts achieved signs of progressive hyperacute rejection and absence of urine output. At the end of experiments we observed moderate to severe hyperacute rejection at small bowel, colon, mesenteric lymph node, liver, spleen, pancreas, and kidney, while stomach and esophagus achieved mild lesions. In contrast, allograft achieved normal or minimum ischemia/reperfusion injury and constant urine output.

Conclusion:  The present procedure assembles a simple and effective model to study multivisceral xenotransplantation and may ultimately spread researches toward hyperacute rejection.
Local expression of IDO, either alone or in combination with CD40Ig, IL10 or CTLA4Ig, inhibits indirect xenorejection responses
Authors: Mulley William R. , Li Yu Qin , Wee Janet L. , Dodge Natalie , Christiansen Dale , Simeonovic Charmaine , Ierino Francesco L. , Sandrin Mauro S.
Published: July 2008

Abstract:  Background:  To overcome cell‐mediated xenorejection by transgenic expression of immunomodulatory molecules by a graft, it is likely that expression of multiple molecules will be required. Previous studies support the use of the immunomodulatory agents indoleamine 2,3‐dioxygenase (IDO), CD40Ig, interleukin 10 (IL10), and CTLA4Ig for suppression of rejection responses. We examined the effects of local expression of these molecules by a porcine cell line (PIEC) on indirect murine xenorejection responses in vitro and in vivo.

Methods:  The PIEC stable lines expressing IDO, CD40Ig, and IL10 as single molecules were generated. In addition, PIEC lines expressing IDO with either CD40Ig, IL10 or CTLA4Ig were generated to produce cell lines expressing two molecules. BALB/c mice were primed with wild type PIEC, followed by harvesting splenocytes used as responder cells and PIEC expressing immunomodulatory molecules as stimulators, in proliferation and cytokine assays. In vivo effects of modified PIEC were examined by transplantation of PIEC lines expressing the immunomodulatory molecules under the renal capsule of naïve mice. PIEC grafts were harvested for histological evaluation at days 7 and 14.

Results:  Proliferation of primed BALB/c splenocytes was inhibited most significantly by IDO compared with control cells (49%, P = 0.02). In addition both Th1 (interferon‐gamma) and Th2 (IL4 and IL10) cytokines were markedly inhibited in vitro by IDO expression. IL10 expressing cells did not inhibit proliferation as potently (37%, P = 0.03) whilst CD40Ig lead to an increase in proliferative responses (59%, P = 0.02). Co‐expression of CD40Ig, IL10, and CTLA4Ig with IDO resulted in further modest reductions in proliferation compared with IDO expression alone. When transplanted under the renal capsule of BALB/c mice, those grafts expressing IDO demonstrated significantly lower levels of lymphocyte infiltration at days 7 and 14 than control grafts and those expressing CD40Ig, CTLA4Ig or IL10 alone. Grafts co‐expressing IDO and a second molecule were no better protected than those expressing IDO alone. Graft cell viability (PIECs) was reduced in some IDO expressing grafts suggesting high levels of IDO expression may inhibit PIEC viability, however, grafts co‐expressing IDO‐CTLA4Ig and IDO‐IL10 were not affected in this way.

Conclusion:  Indoleamine 2,3‐dioxygenase appears to be a potent molecule for protecting xenografts from cell‐mediated rejection responses activated via the indirect pathway. Co‐expression of IDO with both CTLA4Ig and IL10 warrants further investigation. Overall these findings support pursuing further studies, in larger animal models, to determine whether increased IDO activity within the graft itself can attenuate xenorejection responses.
Sexual imprinting on continuous variation: do female zebra finches prefer or avoid unfamiliar sons of their foster parents?
Authors: SCHIELZETH H. , BURGER C. , BOLUND E. , FORSTMEIER W.
Published: July 2008

Sexual imprinting on discrete variation that serves the identification of species, morphs or sexes is well documented. By contrast, sexual imprinting on continuous variation leading to individual differences in mating preferences within a single species, morph and sex has been studied only once (in humans). We measured female preferences in a captive population of wild‐type zebra finches. Individual cross‐fostering ensured that all subjects grew up with unrelated foster parents and nest mates. Females from two cohorts (N = 113) were given a simultaneous choice between (two or four) unfamiliar males, one of which was a genetic son of their foster parents (SFP). We found no significant overall preference for the SFP (combined effect sized = 0.14 ± 0.15). Additionally, we tested if foster parent traits could potentially explain between‐female variation in preferences. However, neither the effectiveness of cooperation between the parents nor male contribution to parental care affected female preferences for the son of the foster father. We conclude that at least in zebra finches sexual imprinting is not a major source of between‐individual variation in mating preferences.
Morph‐ratio variation, population size and female reproductive success in distylous Pulmonaria officinalis (Boraginaceae)
Authors: BRYS R. , JACQUEMYN H. , BEECKMAN T.
Published: July 2008

Theory predicts that morph ratios in heterostylous populations are governed by negative frequency‐dependent selection typically resulting in equal morph ratios at equilibrium. Previous work on the distylous perennial herb Pulmonaria officinalis, however, showed asymmetric mating between floral morphs and a weak self‐incompatibility system, with the long‐styled morph (L‐morph) producing significantly higher seed set following intramorph crosses and even selfing than the short‐styled morph (S‐morph), two aspects thought to affect female fecundity and morph‐ratio variation. Here, we evaluated morph ratios and population size of all known P. officinalis populations in the northern part of Belgium. Morph ratios deviated significantly from 1 : 1 (range 0.09–1 L‐morph frequency, mean = 0.58). Relative fecundity of the S‐morph (i.e. mean seed set of the S‐morph/mean seed set of the L‐morph) was on average 0.73, was positively related to the frequency of the L‐morph, and reached 1 (similar levels of female fecundity) at an average L‐morph frequency of 0.66 in the population. As some small populations had the S‐morph in majority, our results suggest that local morph ratios are influenced both by the relative fecundity of L‐ and S‐morph individuals and by stochastic processes in small populations.