bluuebunny/crossref_metadata_2025_split huggingface dataset:
Blunting Occam's razor: aligning medical education with studies of complexity
Authors: Bleakley Alan 
Published: July 2010

AbstractClinical effectiveness and efficiency in medicine for patient benefit should be grounded in the quality of medical education. In turn, the quality of medical education should be informed by contemporary learning theory that offers high explanatory, exploratory and predictive power. Multiple team‐based health care interventions and associated policy are now routinely explored and explained through complexity theory. Yet medical education – how medical students learn to become doctors and how doctors learn to become clinical specialists or primary care generalists – continues to refuse contemporary, work‐based social learning theories that have deep resonance with models of complexity. This can be explained ideologically, where medicine is grounded in a tradition of heroic individualism and knowledge is treated as private capital. In contrast, social learning theories resonating with complexity theory emphasize adaptation through collaboration, where knowledge is commonly owned. The new era of clinical teamwork demands, however, that we challenge the tradition of autonomy, bringing social learning theories in from the cold, to reveal their affinities with complexity science and demonstrate their powers of illumination. Social learning theories informed by complexity science can act as a democratizing force in medical education, helping practitioners to work more effectively in non‐linear, complex, dynamic systems through inter‐professionalism, shared tolerance of ambiguity and distributed cognition. Taking complexity science seriously and applying its insights demands a shift in cultural mindset in medical education. Inevitably, patterns of resistance will arise to frustrate such potential innovation.
‘If things were simple . . .’: complexity in education
Authors: Davis Brent , Sumara Dennis 
Published: July 2010

AbstractRationale, aims and objectives In this speculative essay, we explore some of the implications and possibilities of complexity thinking for formal education.Methods We begin by developing the working definition that complexity research is the study of learning systems. Drawing on hard (rigorously empirical) complexity research, we critique some of the untenable assumptions and constructs that are typically used to frame those social enterprises that are attentive to adaptive, learning forms – including education, social work and health care. Looking to soft (holistic and more action‐oriented) complexity research, we review some of the insights and advice that have arisen among educational researchers. This part of the discussion is framed by a brief description of an ongoing study of teachers' disciplinary knowledge of mathematics – specifically how complexity theory compels and enables us to grapple with the unique qualities of our ‘object’ of study, its emergence, its relationship to student understanding, and how it is implicated in such grander systems as culture and global ecology.Conclusions We conclude by arguing that complexity theory might be properly construed as a theory of education, in contrast to the many theories that have been imported into and imposed on discussions of education over the past few centuries.
Complexity and health professions education: a basic glossary
Authors: Mennin Stewart 
Published: July 2010

AbstractRationale and aims The study of health professions education in the context of complexity science and complex adaptive systems involves different concepts and terminology that are likely to be unfamiliar to many health professions educators. A list of selected key terms and definitions from the literature of complexity science is provided to assist readers to navigate familiar territory from a different perspective.Terms and concepts include agent, attractor, bifurcation, chaos, co‐evolution, collective variable, complex adaptive systems, complexity science, deterministic systems, dynamical system, edge of chaos, emergence, equilibrium, far from equilibrium, fuzzy boundaries, linear system, non‐linear system, random, self‐organization and self‐similarity.
High‐resolution cryo‐SEM allows direct identification of F‐actin at the inner nuclear membrane of Xenopus oocytes by virtue of its structural features
Authors: WALTHER P. 
Published: July 2010

SummaryThe nuclear envelope of Xenopus laevis stage VI oocytes was studied in a high‐resolution field emission cryo‐scanning electron microscope to compare the level of structural preservation obtainable by different procedures of specimen preparation. All approaches generally allowed frequent detection of long filaments of about 10 nm in diameter that were attached to the nuclear envelope's inner membrane facing the nuclear interior. Structural details of these 10‐nm filaments, however, could not be unveiled by standard procedures of specimen preparation and analysis, including critical point drying and imaging at room temperature. In contrast, after freeze‐drying and imaging at −100°C, the 10‐nm filament type was found to be composed of distinct globular subunits of approximately 5 nm in diameter that were arranged in a helical manner with right‐handed periodicity. Stereoscopic images showed that some of these filaments were lying directly on the membrane whereas others appeared to hover at a certain distance above the nuclear envelope. The appearance of these filaments was highly similar to that of in vitro polymerized F‐actin analysed in parallel, and closely resembled the structural characteristics of F‐actin filaments described earlier. By virtue of their structural features we therefore conclude that these filaments at the nuclear periphery represent F‐actin. The high level of structural resolution obtainable by field emission cryo‐SEM illustrates the potential of this method for studying details of biological structures in a subcellular context.
A new pathway for the synthesis of α‐ribazole‐phosphate in Listeria innocua
Authors: Gray Michael J. , Escalante‐Semerena Jorge C. 
Published: July 2010

SummaryThe genomes of Listeria spp. encode all but one of 25 enzymes required for the biosynthesis of adenosylcobalamin (AdoCbl; coenzyme B12). Notably, all Listeria genomes lack CobT, the nicotinamide mononucleotide:5,6‐dimethylbenzimidazole (DMB) phosphoribosyltransferase (EC 2.4.2.21) enzyme that synthesizes the unique α‐linked nucleotide N1‐(5‐phospho‐α‐d‐ribosyl)‐DMB (α‐ribazole‐5′‐P, α‐RP), a precursor of AdoCbl. We have uncovered a new pathway for the synthesis of α‐RP in Listeria innocua that circumvents the lack of CobT. The cblT and cblS genes (locus tags lin1153 and lin1110) of L. innocua encode an α‐ribazole (α‐R) transporter and an α‐R kinase respectively. Results from in vivo experiments indicate that L. innocua depends on CblT and CblS activities to salvage exogenous α‐R, allowing conversion of the incomplete corrinoid cobinamide (Cbi) into AdoCbl. Expression of the L. innocua cblT and cblS genes restored AdoCbl synthesis from Cbi and α‐R in a Salmonella enterica cobT strain. LinCblT transported α‐R across the cell membrane, but not α‐RP or DMB. UV‐visible spectroscopy and mass spectrometry data identified α‐RP as the product of the ATP‐dependent α‐R kinase activity of LinCblS. Bioinformatics analyses suggest that α‐R salvaging occurs in important Gram‐positive human pathogens.
The Bps polysaccharide of Bordetella pertussis promotes colonization and biofilm formation in the nose by functioning as an adhesin
Authors: Conover Matt S. , Sloan Gina Parise , Love Cheraton F. , Sukumar Neelima , Deora Rajendar 
Published: July 2010

SummaryMany respiratory pathogens establish persistent infection or a carrier state in the human nasopharynx without overt disease symptoms but the presence of these in the lungs usually results in disease. Although the anatomy and microenvironments between nasopharynx and lungs are different, a virulence factor with an organ‐specific function in the colonization of the nasopharynx is unknown. In contrast to the severity of pertussis and mortality in non‐vaccinated young children, Bordetella pertussis results in milder and prolonged cough in vaccinated adolescents and adults. Individuals harbouring bacteria in the nasopharynx serve as reservoirs for intrafamilial and nosocomial transmission. We show that the Bps polysaccharide of B. pertussis is critical for initial colonization of the mouse nose and the trachea but not of the lungs. Our data reveal a biofilm lifestyle for B. pertussis in the nose and the requirement of Bps in this developmental process. Bps functions as an adhesin by promoting adherence of B. pertussis and Escherichia coli to human nasal but not to human lung epithelia. Patient serum specifically recognized Bps suggesting its expression during natural human infections. We describe the first bacterial factor that exhibits a differential role in colonization and adherence between the nasopharynx and the lungs.
Characterization of a DNA damage‐inducible membrane protein kinase from Deinococcus radiodurans and its role in bacterial radioresistance and DNA strand break repair
Authors: Rajpurohit Yogendra S. , Misra Hari S. 
Published: July 2010

Summary Deinococcus radiodurans mutant lacking pyrroloquinoline–quinone (PQQ) synthesis shows sensitivity to γ‐rays and impairment of DNA double strand break repair. The genome of this bacterium encodes five putative proteins having multiple PQQ binding motifs. The deletion mutants of corresponding genes were generated, and their response to DNA damage was monitored. Only the Δdr2518 mutant exhibited higher sensitivity to DNA damage. Survival of these cells decreased by 3‐log cycle both at 6 kGy γ‐rays and 1200 J m−2 UV (254 nm) radiation, and 2.5‐log cycle upon 14 days desiccation at 5% humidity. The Δdr2518 mutant showed complete inhibition of DSB repair until 24 h PIR and disappearance of a few phosphoproteins. The Δdr2518pqqE:cat double mutant showed γ‐ray sensitivity similar to Δdr2518 indicating functional interaction of these genes in D. radiodurans. DR2518 contains a eukaryotic type Ser/Thr kinase domain and structural topology suggesting stress responsive transmembrane protein. Its autokinase activity in solution was stimulated by nearly threefold with PQQ and twofold with linear DNA, but not with circular plasmid DNA. More than 15‐fold increase in dr2518 transcription and several‐fold enhanced in vivo phosphorylation of DR2518 were observed in response to γ irradiation. These results suggest that DR2518 as a DNA damage‐responsive protein kinase plays an important role in radiation resistance and DNA strand break repair in D. radiodurans.
Caspase‐12 deficiency enhances cytokine responses but does not protect against lethal Plasmodium yoelii 17XL infection
Authors: MIU J. , SALEH M. , STEVENSON M. M. 
Published: July 2010

SummaryTo investigate the effect of caspase‐12 deficiency on IFN‐γ‐independent control of blood‐stage malaria, we compared lethal Plasmodium yoelii 17XL infection in wild‐type C57BL/6J and caspase‐12−/− mice. Infected caspase‐12−/− mice exhibited higher parasitaemia than WT mice on days 8 and 9 post‐inoculation, but all WT and caspase‐12−/− mice succumbed by day 10. In addition, infected caspase‐12−/− mice had significantly elevated levels of IFN‐γ, TNF, IL‐18, and IL‐10 in sera compared to infected WT mice. At the terminal stage of disease, there were no differences in cytokine levels in the tissues of infected WT and caspase‐12−/− mice. However, liver pathology was more severe in infected caspase‐12−/− mice compared to infected WT mice. Together, these findings indicate that although caspase‐12 deficiency results in enhanced pro‐inflammatory and immunoregulatory cytokine levels in sera during P. yoelii 17XL infection, these responses are not essential for protection against lethal malaria infection.
Chute channels in the Holocene high‐sinuosity river deposits of the Firenze plain, Tuscany, Italy
Authors: GHINASSI MASSIMILIANO 
Published: July 2010

AbstractThis paper focuses on Holocene deposits of the Firenze alluvial plain (Northern Apennines, Italy) and deals with the sedimentary features of chute channels draining the down‐river edges of the meander neck formed by 70 to 100 m wide and 1 to 1·5 m deep sinuous channels. Two main types of chute channels have been recognized. Type 1 is represented by 3 to 6 m wide and 0·5 to 1 m deep straight channels filled with mud aggregates overlying a basal gravel lag made of reworked caliches. These channels drained the point bar top during floods, and are thought to have been initiated as small rills when a shallow flow overpassed the downstream side of the point bar. Type 2 channels, 3 to 6 m wide and 1 to 1·5 m deep, are moderately to highly sinuous and filled with well‐stratified sand and gravels sourced from nearby rocky highlands. Type 2 channels were connected to the main river channel also during the base flow stage. The transition from Type 1 to Type 2 channels is documented and is interpreted as the result of the meander cut‐off process. Type 1 chute channels represent the early stage of the cut‐off phase, when a headcut is incised on the down‐river edges of the meander neck. The headcut migrates up‐river across the meander neck during floods, when fast currents shape the chute channels into a straight route. The transition from Type 1 into Type 2 channels is linked to the connection of the up‐river migrating headcut with the main channel and the termination of the cut‐off process. At this stage, the cut‐off channel is drained permanently and receives bedload from the main channel. The progressive shaping of the newly formed channel will convert it into the main channel and lead to the formation of an oxbow lake in the abandoned meander branch. Development of chute channels in the Firenze alluvial plain is thought to have heralded a decrease in sinuosity of the main channels, triggered by a climate‐driven increase in water discharge.
Histological Features in the Mammary Glands of Female Dogs throughout Lactation
Authors: Orfanou D. C. , Pourlis A. , Ververidis H. N. , Mavrogianni V. S. , Taitzoglou I. A. , Boscos C. M. , Fthenakis G. C. 
Published: July 2010

With 3 tables and 2 figuresSummaryThe objective of this study was to describe the histology of the mammary glands of female dogs throughout lactation. Twelve lactating female dogs were operated 4, 7, 10, 14, 21, 28, 35, 42, 56, 70 and 84 days post‐partum; four mammary glands of each animal were excised for histological, ultrastructural and morphometric examination. During early lactation and mid‐lactation, all lobes and lobules within the same gland had similar features; alveoli were well developed and distended and had a spherical to slightly ovoid structure, with muscular fibres grasping them around; inflammatory cells were seen in the inter‐ and intra‐alveolar space; mammary lobules were separated with a scant amount of connective tissue. In late lactation, connective tissue was abundant and dense, with large numbers of inflammatory cells; alveoli appeared to be irregularly shaped and collapsing, shrunken or fully collapsed. Number of alveoli per lobule and number of epithelial cells per alveolus, as well as diameter of alveoli and height of epithelial cells decreased as lactation progressed. The third mammary glands (from caudal to cranial) had a significantly smaller number of alveoli, but not of epithelial cells per alveolus, than each of the two mammary glands caudally to that. The results suggest that progressive involution of the normal mammary gland starts around the end of the 2nd month of lactation and continues until the end of the 3rd month.
Comparison of genomic and traditional BLUP‐estimated breeding value accuracy and selection response under alternative trait and genomic parameters
Authors: Muir W.M. 
Published: July 2010

SummaryAccuracy of prediction of estimated breeding values based on genome‐wide markers (GEBV) and selection based on GEBV as compared with traditional Best Linear Unbiased Prediction (BLUP) was examined for a number of alternatives, including low heritability, number of generations of training, marker density, initial distributions, and effective population size (Ne). Results show that the more the generations of data in which both genotypes and phenotypes were collected, termed training generations (TG), the better the accuracy and persistency of accuracy based on GEBV. GEBV excelled for traits of low heritability regardless of initial equilibrium conditions, as opposed to traditional marker‐assisted selection, which is not useful for traits of low heritability. Effective population size is critical for populations starting in Hardy‐Weinberg equilibrium but not for populations started from mutation‐drift equilibrium. In comparison with traditional BLUP, GEBV can exceed the accuracy of BLUP provided enough TG are included. Unfortunately selection rapidly reduces the accuracy of GEBV. In all cases examined, classic BLUP selection exceeds what was possible for GEBV selection. Even still, GEBV could have an advantage over traditional BLUP in cases such as sex‐limited traits, traits that are expensive to measure, or can only be measured on relatives. A combined approach, utilizing a mixed model with a second random effect to account for quantitative trait loci in linkage equilibrium (the polygenic effect) was suggested as a way to capitalize on both methodologies.
Environmental drivers of ophiuroid species richness on seamounts
Authors: O’Hara Timothy D. , Tittensor Derek P. 
Published: July 2010

AbstractBenthic communities on seamounts are frequently characterised as being species rich, yet there is considerable variation in observed species richness. Although large‐scale patterns of species richness have been described from many marine and terrestrial habitats, their environmental drivers often remain poorly understood. We compared species richness of ophiuroids (brittle‐stars) on 60 seamounts throughout the South West Pacific Ocean, and used an information‐theoretic approach and generalized linear models to determine the relative importance of predictor variables. Due to high correlation among many environmental variables, we used a reduced set of predictors in an a priori model framework. Temperature was the only environmental predictor of any importance in these models over the bathymetric range of the study. Post‐hoc analyses of other potential environmental predictor variables showed that depth, calcite saturation state, temperature range, modelled current velocity and latitude all had some predictive value, but were also highly correlated with temperature or other environmental variables included in the a priori model. Longitude, large‐area species richness, habitat suitability for stony corals, and modelled POC flux did not have high predictive value. We hypothesise that temperature affects richness by constraining species distributions; in particular fewer species can tolerate the conditions on relatively warm shallow seamount summits.
Squat lobster assemblages on seamounts differ from some, but not all, deep‐sea habitats of comparable depth
Authors: Rowden Ashley A. , Schnabel Kareen E. , Schlacher Thomas A. , Macpherson Enrique , Ahyong Shane T. , Richer de Forges Bertrand 
Published: July 2010

AbstractThis study was carried out to test the hypothesis that benthic communities on seamounts are distinct from those of other deep‐sea habitats at comparable depths. Analysis of the squat lobster fauna of deep‐sea habitats in the Southwestern Pacific revealed that the species composition of assemblages on seamounts was not statistically dissimilar from assemblages on slope and plateau habitat at comparable depths. However, compositional differences were observed between seamount and rise and ridge habitat. Differences in assemblage composition between seamount and ridge habitat were statistically significant for two of the four ridge systems examined. Assemblages on seamounts that were distinct from non‐seamount ridge habitat were typically dominated by small‐bodied species with an abbreviated larval stage. Various environmental variables were correlated with the observed assemblage patterns observed; depth‐related variables may account for differences between seamount and rise assemblages, whilst differences in POC flux likely play a role in determining the assemblage compositional patterns between seamount and non‐seamount ridge habitat. Extensive pre‐analysis data treatment was required to ensure that multivariate analyses of assemblage data from seamount and non‐seamount habitats were robust. Our results confirm the findings of recent studies that found no compositional differences in assemblages from seamount and slope habitats, and support the idea that dissimilarity between seamount assemblages on different ridge systems increases with geographic distance. Further research will be required before the generality of these findings can be confirmed.
Second to fourth digit ratio: a predictor of prostate‐specific antigen level and the presence of prostate cancer
Authors: Jung Han , Kim Khae Hawn , Yoon Sang Jin , Kim Tae Beom 
Published: July 2010

Study Type – Diagnostic (exploratory cohort) Level of Evidence 2b What’s known on the subject? and What does the study add? The Homeobox genes, Hox a and d, control urinogenital system differentiation and digit development. The patterns of digit formation may be related to gonad function and may be reflected in 2nd to 4th digit ratio (digit ratio). Digit ratio is negatively correlated with prenatal testosterone levels and androgen receptor activity which is related to the increased prostate cancer risk.Patients with a lower digit ratio have a higher risk of prostate biopsy due to high PSA level, and of prostate cancer. Digit ratio could be a predictor of high PSA level and the presence of prostate cancer.OBJECTIVETo investigate the relationships between the 2nd to 4th digit ratio (digit ratio) and prostate volume, prostate‐specific antigen (PSA) level, and the presence of prostate cancer.PATIENTS AND METHODSOf the men that presented with lower urinary tract symptoms (LUTS) at a single tertiary academic center, 366 men aged 40 or older with a PSA level ≤40 ng/mL were prospectively enrolled. Right‐hand 2nd and 4th digit lengths were measured prior to the PSA determinations and transrectal ultrasonography (TRUS). Prostate volumes were measured by TRUS without information about digit length. Patients with a PSA level ≥3 ng/mL underwent prostate biopsy.RESULTSNo relationship was found between prostate volume and digit ratio [correlation coefficient (r) =−0.038, P= 0.466]. But, significant negative correlations were found between digit ratio and PSA (r=−0.140, P= 0.007). When the patients were divided into two groups (Group A: digit ratio <0.95, n= 184; Group B: digit ratio ≥0.95, n= 182), Group A had a higher mean PSA level than Group B (3.26 ± 5.54 ng/mL vs 1.89 ± 2.24 ng/mL, P= 0.002) and had significantly higher risks of prostate biopsy [odds ratio (OR) = 1.75, 95% CI = 1.07–2.84] and prostate cancer (OR = 3.22, 95% CI = 1.33–7.78).CONCLUSIONSPatients with a lower digit ratio have higher risks of prostate biopsy and prostate cancer.