bluuebunny/crossref_metadata_2025 huggingface dataset:
Arp2/3 mediates early endosome dynamics necessary for the maintenance of PAR asymmetry in Caenorhabditis elegans
Authors: Shivas Jessica M. , Skop Ahna R.
Published: March 2012

The widely conserved Arp2/3 complex regulates branched actin dynamics that are necessary for a variety of cellular processes. In Caenorhabditis elegans, the actin cytoskeleton has been extensively characterized in its role in establishing PAR asymmetry; however, the contributions of actin to the maintenance of polarity before the onset of mitosis are less clear. Endocytic recycling has emerged as a key mechanism in the dynamic stabilization of cellular polarity, and the large GTPase dynamin participates in the stabilization of cortical polarity during maintenance phase via endocytosis in C. elegans. Here we show that disruption of Arp2/3 function affects the formation and localization of short cortical actin filaments and foci, endocytic regulators, and polarity proteins during maintenance phase. We detect actin associated with events similar to early endosomal fission, movement of endosomes into the cytoplasm, and endosomal movement from the cytoplasm to the plasma membrane, suggesting the involvement of actin in regulating processes at the early endosome. We also observe aberrant accumulations of PAR-6 cytoplasmic puncta near the centrosome along with early endosomes. We propose a model in which Arp2/3 affects the efficiency of rapid endocytic recycling of polarity cues that ultimately contributes to their stable maintenance.
Initiating head development in mouse embryos: integrating signalling and transcriptional activity
Authors: Arkell Ruth M. , Tam Patrick P. L.
Published: March 2012

The generation of an embryonic body plan is the outcome of inductive interactions between the progenitor tissues that underpin their specification, regionalization and morphogenesis. The intercellular signalling activity driving these processes is deployed in a time- and site-specific manner, and the signal strength must be precisely controlled. Receptor and ligand functions are modulated by secreted antagonists to impose a dynamic pattern of globally controlled and locally graded signals onto the tissues of early post-implantation mouse embryo. In response to the WNT, Nodal and Bone Morphogenetic Protein (BMP) signalling cascades, the embryo acquires its body plan, which manifests as differences in the developmental fate of cells located at different positions in the anterior–posterior body axis. The initial formation of the anterior (head) structures in the mouse embryo is critically dependent on the morphogenetic activity emanating from two signalling centres that are juxtaposed with the progenitor tissues of the head. A common property of these centres is that they are the source of antagonistic factors and the hub of transcriptional activities that negatively modulate the function of WNT, Nodal and BMP signalling cascades. These events generate the scaffold of the embryonic head by the early-somite stage of development. Beyond this, additional tissue interactions continue to support the growth, regionalization, differentiation and morphogenesis required for the elaboration of the structure recognizable as the embryonic head.
Epidemic history of hepatitis C virus infection in two remote communities in Nigeria, West Africa
Authors: Forbi Joseph C. , Purdy Michael A. , Campo David S. , Vaughan Gilberto , Dimitrova Zoya E. , Ganova-Raeva Lilia M. , Xia Guo-liang , Khudyakov Yury E.
Published: March 2012

We investigated the molecular epidemiology and population dynamics of HCV infection among indigenes of two semi-isolated communities in North-Central Nigeria. Despite remoteness and isolation, ~15 % of the population had serological or molecular markers of hepatitis C virus (HCV) infection. Phylogenetic analysis of the NS5b sequences obtained from 60 HCV-infected residents showed that HCV variants belonged to genotype 1 (n = 51; 85 %) and genotype 2 (n = 9; 15 %). All sequences were unique and intermixed in the phylogenetic tree with HCV sequences from people infected from other West African countries. The high-throughput 454 pyrosequencing of the HCV hypervariable region 1 and an empirical threshold error correction algorithm were used to evaluate intra-host heterogeneity of HCV strains of genotype 1 (n = 43) and genotype 2 (n = 6) from residents of the communities. Analysis revealed a rare detectable intermixing of HCV intra-host variants among residents. Identification of genetically close HCV variants among all known groups of relatives suggests a common intra-familial HCV transmission in the communities. Applying Bayesian coalescent analysis to the NS5b sequences, the most recent common ancestors for genotype 1 and 2 variants were estimated to have existed 675 and 286 years ago, respectively. Bayesian skyline plots suggest that HCV lineages of both genotypes identified in the Nigerian communities experienced epidemic growth for 200–300 years until the mid-20th century. The data suggest a massive introduction of numerous HCV variants to the communities during the 20th century in the background of a dynamic evolutionary history of the hepatitis C epidemic in Nigeria over the past three centuries.
Impact of microRNA regulation on variation in human gene expression
Authors: Lu Jian , Clark Andrew G.
Published: March 2012

MicroRNAs (miRNAs) are endogenously expressed small RNAs that regulate expression of mRNAs at the post-transcriptional level. The consequence of miRNA regulation is hypothesized to reduce the expression variation of target genes. However, it is possible that mutations in miRNAs and target sites cause rewiring of the miRNA regulatory networks resulting in increased variation in gene expression. By examining variation in gene expression patterns in human populations and between human and other primate species, we find that miRNAs have stabilized expression of a small number of target genes during primate evolution. Compared with genes not regulated by miRNAs, however, genes regulated by miRNAs overall have higher expression variation at the population level, and they display greater variation in expression among human ethnic groups or between human and other primate species. By integrating expression data with genotypes determined in the HapMap 3 and the 1000 Genomes Projects, we found that expression variation in miRNAs, genetic variants in miRNA loci, and mutations in miRNA target sites are important sources of elevated expression variation of miRNA target genes. A reasonable case can be made that natural selection is driving this pattern of variation.
A genome-wide analysis of common fragile sites: What features determine chromosomal instability in the human genome?
Authors: Fungtammasan Arkarachai , Walsh Erin , Chiaromonte Francesca , Eckert Kristin A. , Makova Kateryna D.
Published: March 2012

Chromosomal common fragile sites (CFSs) are unstable genomic regions that break under replication stress and are involved in structural variation. They frequently are sites of chromosomal rearrangements in cancer and of viral integration. However, CFSs are undercharacterized at the molecular level and thus difficult to predict computationally. Newly available genome-wide profiling studies provide us with an unprecedented opportunity to associate CFSs with features of their local genomic contexts. Here, we contrasted the genomic landscape of cytogenetically defined aphidicolin-induced CFSs (aCFSs) to that of nonfragile sites, using multiple logistic regression. We also analyzed aCFS breakage frequencies as a function of their genomic landscape, using standard multiple regression. We show that local genomic features are effective predictors both of regions harboring aCFSs (explaining ∼81% of the deviance in logistic regression models) and of aCFS breakage frequencies (explaining ∼45% of the variance in standard regression models). In our optimal models (based on a combination of biological interpretability and high R-squared value), aCFSs are predominantly located in G-negative chromosomal bands and away from centromeres, are enriched in Alu repeats, and have high DNA flexibility. In alternative models, CpG island density, H3K4me1 coverage, and mononucleotide microsatellite coverage are significant predictors. Also, aCFSs have high fragility when colocated with evolutionarily conserved chromosomal breakpoints. Our models are predictive of the fragility of aCFSs mapped at a higher resolution. Importantly, the genomic features we identified here as significant predictors of fragility allow us to draw valuable inferences on the molecular mechanisms underlying aCFSs.
Regulation of Plasmodesmatal Permeability and Stomatal Patterning by the Glycosyltransferase-Like Protein KOBITO1
Authors: Kong Danyu , Karve Rucha , Willet Alaina , Chen Ming-Kun , Oden Jennifer , Shpak Elena D.
Published: March 2012

The differentiation of stomata provides a convenient model for studying pattern formation in plant tissues. Stomata formation is induced by a set of basic helix-loop-helix transcription factors and inhibited by a signal transduction pathway initiated by TOO MANY MOUTHS (TMM) and ERECTA family (ERf) receptors. The formation of a proper stomata pattern is also dependent upon the restriction of symplastic movement of basic helix-loop-helix transcription factors into neighboring cells, especially in the backgrounds where the function of the TMM/ERf signaling pathway is compromised. Here, we describe a novel mutant of KOBITO1 in Arabidopsis (Arabidopsis thaliana). The kob1-3 mutation leads to the formation of stomata clusters in the erl1 erl2 background but not in the wild type. Cell-to-cell mobility assays demonstrated an increase in intercellular protein trafficking in kob1-3, including increased diffusion of SPEECHLESS, suggesting that the formation of stomata clusters is due to an escape of cell fate-specifying factors from stomatal lineage cells. While plasmodesmatal permeability is increased in kob1-3, we did not detect drastic changes in callose accumulation at the neck regions of the plasmodesmata. Previously, KOBITO1 has been proposed to function in cellulose biosynthesis. Our data demonstrate that disruption of cellulose biosynthesis in the erl1 erl2 background does not lead to the formation of stomata clusters, indicating that cellulose biosynthesis is not a major determining factor for regulating plasmodesmatal permeability. Analysis of KOBITO1 structure suggests that it is a glycosyltransferase-like protein. KOBITO1 might be involved in a carbohydrate metabolic pathway that is essential for both cellulose biosynthesis and the regulation of plasmodesmatal permeability.
Evolution of a Complex Disease Resistance Gene Cluster in DiploidPhaseolusand TetraploidGlycine
Authors: Ashfield Tom , Egan Ashley N. , Pfeil Bernard E. , Chen Nicolas W.G. , Podicheti Ram , Ratnaparkhe Milind B. , Ameline-Torregrosa Carine , Denny Roxanne , Cannon Steven , Doyle Jeff J. , Geffroy Valérie , Roe Bruce A. , Saghai Maroof M.A. , Young Nevin D. , Innes Roger W.
Published: March 2012

We used a comparative genomics approach to investigate the evolution of a complex nucleotide-binding (NB)-leucine-rich repeat (LRR) gene cluster found in soybean (Glycine max) and common bean (Phaseolus vulgaris) that is associated with several disease resistance (R) genes of known function, including Rpg1b (for Resistance to Pseudomonas glycinea1b), an R gene effective against specific races of bacterial blight. Analysis of domains revealed that the amino-terminal coiled-coil (CC) domain, central nucleotide-binding domain (NB-ARC [for APAF1, Resistance genes, and CED4]), and carboxyl-terminal LRR domain have undergone distinct evolutionary paths. Sequence exchanges within the NB-ARC domain were rare. In contrast, interparalogue exchanges involving the CC and LRR domains were common, consistent with both of these regions coevolving with pathogens. Residues under positive selection were overrepresented within the predicted solvent-exposed face of the LRR domain, although several also were detected within the CC and NB-ARC domains. Superimposition of these latter residues onto predicted tertiary structures revealed that the majority are located on the surface, suggestive of a role in interactions with other domains or proteins. Following polyploidy in the Glycine lineage, NB-LRR genes have been preferentially lost from one of the duplicated chromosomes (homeologues found in soybean), and there has been partitioning of NB-LRR clades between the two homeologues. The single orthologous region in common bean contains approximately the same number of paralogues as found in the two soybean homeologues combined. We conclude that while polyploidization in Glycine has not driven a stable increase in family size for NB-LRR genes, it has generated two recombinationally isolated clusters, one of which appears to be in the process of decay.
Poly[(μ3-benzene-1,4-dicarboxylato)di-μ-chlorido-(triethanolamine)dicadmium(II)]: a cadmium–halide coordination polymer with a hydrogen-bonded three-dimensional framework
Authors: He Xiyun , Lv Jianyi , Xu Guohai
Published: March 2012

The structure of the title compound, [Cd2(C8H4O4)Cl2(C6H15NO3)]n, consists of one-dimensional chains in which each centrosymmetric tetranuclear Cd4Cl4O2cluster is terminated by two chelating triethanolamine (teaH3) ligands but linked to two adjacent clusters through four bridging benzene-1,4-dicarboxylate (bdc) ligands. The tetranuclear Cd4Cl4O2clusters are held togetherviabridging Cl and O atoms. Three directional hydrogen bonds from the multi-podal hydroxy groups of the teaH3ligand stabilize and extend the one-dimensional chains into a three-dimensional framework. All three hydroxy groups of the teaH3ligand form hydrogen bonds, illustrating the fact that the teaH3ligand can serve as an excellent hydrogen-bond donor.
Di-μ-methanolato-bis[(η4-tetrafluorobenzobarrelene)rhodium(I)]
Authors: García-Orduña Pilar , Mena Inmaculada , Casado Miguel A. , Lahoz Fernando J.
Published: March 2012

The versatile synthetic precursor methanolate-bridged title rhodium complex, [Rh2(CH3O)2(C12H6F4)2] or [Rh(μ-OCH3)(tfbb)]2[tfbb = tetrafluorobenzobarrelene or 3,4,5,6-tetrafluorotricyclo[6.2.2.02,7]dodeca-2(7),3,5,9,11-pentaene], has been structurally characterized. The asymmetric unit contains half a molecule that can be expandedviaa twofold axis. The title compound has been shown to be a dinuclear rhodium complex where each metal centre is coordinated by two O atoms from two bridging methanolate groups and by the olefinic bonds of a tfbb ligand. Comparison of the bite angles of tfbb, norbornadiene (nbd) and cyclooctadiene (cod) olefins in their η4-coordination to rhodium reveals similarities between the tfbb and nbd ligands, which are much more rigid than cod. The short distance found between the distorted square-planar metal centres [2.8351 (4) Å] has been related to thesynconformation of the folded core `RhORhO' ring.
Seasonal wing colour plasticity varies dramatically between buckeye butterfly populations in different climatic zones
Authors: DANIELS EMILY V. , MOONEY KAILEN A. , REED ROBERT D.
Published: March 2012

1. In the present study, how seasonal wing colour plasticity in buckeye butterflies (Junonia coenia Hübner) differs between populations in different climatic regions, and whether these differences are explained by regional environmental differences or reflect genetic divergences in plasticity is addressed.

2. Using museum specimen data, it is shown that buckeye wing colour variation is much greater in populations from the humid and subtropical climates of the eastern U.S.A. than in populations from the desert and mediterranean climates of the western U.S.A.

3. Museum specimen data further show that wing colour in eastern populations is strongly correlated with seasonal variation in day length and temperature, whereas wing colour in western populations is only weakly associated with these cues.

4. Controlled incubator experiments comparing Southern California and North Carolina populations suggest that regional differences in wing pattern variation are attributable to dramatically increased robustness to environmental variation in western populations.

5. Together these experiments show that while phenotypic variation can be influenced by environmental cues, the range of this variation can genetically diverge between populations in different regions.
Sharing the same space: foraging behaviour of saproxylic beetles in relation to dietary components of morphologically similar larvae
Authors: PŘIKRYL ZDENĚK B. , TURČÁNI MAREK , HORÁK JAKUB
Published: March 2012

1. Saproxylic beetles (Coleoptera) have particular requirements for dead wood. Little is known about their larval development, especially within intermediate and late stages of dead wood decay.

2. We studied the natural foraging behaviour of three saproxylic beetles with morphologically similar (i.e. convergent) larvae and similar habitat requirements –Cucujus cinnaberinus Scopoli (Cucujidae), Pyrochroa coccinea L., and Schizotus pectinicornis L. (Pyrochroidae) – examining dietary components using visual gut content analysis.

3. There were few significant differences in diet among the study species, but there were significant differences for the different dietary components in individual species. Guts of all three species included more plant and fungal material than animal. We also observed that with increasing body size larvae foraged significantly less on fungal material. We observed significant differences among species and selection with respect to body size during the overwintering period. Larvae swallowed more animal and less fungal material with increasing body size.

4. The study species seem to be opportunistic foragers, varying their foraging capability according to seasonality and age. They probably generally foraged woody material infested by filamentous fungi (i.e. xylomycetophagy), swallowing other material that is in their way while foraging, including animal parts and small arthropods.

5. We found that morphologically similar larvae do not differ much in their foraging behaviour even when sharing the same habitat. Larval size seems to be a useful predictor for foraging behaviour of saproxylic beetles within the same guild. The study species are probably occasional predators with less ability to forage on other animals than previously suggested.
First evidence that marine protected areas can work for marine mammals
Authors: Gormley Andrew M. , Slooten Elisabeth , Dawson Steve , Barker Richard J. , Rayment Will , du Fresne Sam , Bräger Stefan
Published: March 2012

1. Marine protected areas (MPAs) have been advocated for the protection of threatened marine mammals, but there is no empirical evidence that they are effective. In 1988, the Banks Peninsula Marine Mammal Sanctuary was established to reduce gillnet mortalities of Hector’s dolphin Cephalorhynchus hectori, an endangered dolphin species endemic to New Zealand. This study assesses the effectiveness of the MPA in improving the survival rate of Hector’s dolphin at Banks Peninsula.

2. Over 21 years, we undertook photo‐identification surveys of Hector’s dolphins along standardized transects from small outboard‐powered boats. From 1986 to 2006, we photographically captured 462 reliably marked individuals. We estimated mean annual survival during the pre‐sanctuary and post‐sanctuary periods by applying a Bayesian random effects capture‐recapture model to the data. Population growth was estimated from population simulations using a stage‐structured matrix model.

3. We estimate a 90% probability that survival has improved between the pre‐sanctuary and post‐sanctuary periods, with estimates of mean survival probability increasing by 5·4% (from 0·863 to 0·917). This improvement in survival corresponds to a 6% increase in mean annual population growth (from 0·939 to 0·995).

4. Synthesis and applications. Our study demonstrates improvement in a demographic parameter of an endangered marine mammal species following conservation action. Our results provide evidence that area‐based protection measures can be effective for marine mammals. We note that estimating demographic parameters in marine mammals requires many years of data to achieve sufficient precision to detect biologically meaningful change. MPAs should be established with a commitment to long‐term monitoring.
Obtaining the mean relative weights of the cost of care in Catalonia (Spain): retrospective application of the adjusted clinical groups case‐mix system in primary health care
Authors: Sicras‐Mainar Antoni , Velasco‐Velasco Soledad , Navarro‐Artieda Ruth , Jodar Alba Aguado , Plana‐Ripoll Oleguer , Hermosilla‐Pérez Eduardo , Bolibar‐Ribas Bonaventura , Prados‐Torres Alejandra , Violan‐Fors Concepción
Published: March 2012

Objective  The study aims to obtain the mean relative weights (MRWs) of the cost of care through the retrospective application of the adjusted clinical groups (ACGs) in several primary health care (PHC) centres in Catalonia (Spain) in routine clinical practice.

Methods  This is a retrospective study based on computerized medical records. All patients attended by 13 PHC teams in 2008 were included. The principle measurements were: demographic variables (age and sex), dependent variables (number of diagnoses and total costs), and case‐mix or co‐morbidity variables (International Classification of Primary Care). The costs model for each patient was established by differentiating the fix costs from the variable costs. In the bivariate analysis, the Student's t, analysis of variance, chi‐squared, Pearson's linear correlation and Mann–Whitney–Wilcoxon tests were used. In order to compare the MRW of the present study with those of the United States (US), the concordance [intraclass correlation coefficient (ICC) and concordance correlation coefficient (CCC)] and the correlation (coefficient of determination: R2) were measured.

Results  The total number of patients studied was 227 235, and the frequentation was 5.9 visits/habitant/year) and with a mean diagnoses number of 4.5 (3.2). The distribution of costs was €148.7 million, of which 29.1% were fixed costs. The mean total cost per patient/year was €654.2 (851.7), which was considered to be the reference MRW. Relationship between study‐MRW and US‐MRW: ICC was 0.40 [confidential interval (CI) 95%: 0.21–0.60] and the CCC was 0.42 (CI 95%: 0.35–0.49). The correlation between the US MRW and the MRW of the present study can be seen; the adjusted R2 value is 0.691. The explanatory power of the ACG classification was 36.9% for the total costs. The R2 of the total cost without considering outliers was 56.9%.

Conclusions  The methodology has been shown appropriate for promoting the calculation of the MRW for each category of the classification. The results provide a possible practical application in PHC clinical management.
First trimester Down syndrome screening is less effective and the number of invasive procedures is increased in women younger than 35 years of age
Authors: Peuhkurinen Sini , Laitinen Paivi , Ryynanen Markku , Marttala Jaana
Published: March 2012

Objectives  We evaluated the performance of first trimester screening for Down syndrome in women less than 35 years of age (study group) and in women aged 35 years or more (control group) in an unselected low‐risk population.

Methods  The study group comprised a total of 63 945 women who participated in the first trimester combined screening in public health care in Finland during the study period of 1 May 2002 to 31 December 2008. Women at the age of 35 or more (n = 13 004) were controls. Prevalence of Down syndrome, detection rate, false positive rate and number of invasive procedures needed to detect a single case of Down syndrome were analyzed in both groups.

Results  The overall prevalence of Down syndrome (n = 73) in the study group was 1:876. The number of detected cases was 54. The detection rate was 74.0% with a false positive rate of 2.8%. Number of invasive procedures needed to detect a single case of Down syndrome was 33. In the control group, the detection rate was 87.0% with a false positive rate of 11.9%. The number of invasive procedures needed to detect a single case of Down syndrome was 15. The differences in detection rate and false positive rate were significant, P < 0.012, P < 0.001, respectively.

Conclusion  The overall detection rate given for the entire population is an overestimate for a woman younger than the age of 35, which should be taken into consideration when counselling women of that age.
Development and testing of hyperbaric atomic force microscopy (AFM) and fluorescence microscopy for biological applications
Authors: D’AGOSTINO D.P. , MCNALLY H.A. , DEAN J.B.
Published: March 2012

A commercially available atomic force microscopy and fluorescence microscope were installed and tested inside a custom‐designed hyperbaric chamber to provide the capability to study the effects of hyperbaric gases on biological preparations, including cellular mechanism of oxidative stress. In this report, we list details of installing and testing atomic force microscopy and fluorescence microscopy inside a hyperbaric chamber. The pressure vessel was designed to accommodate a variety of imaging equipment and ensures full functionality at ambient and hyperbaric conditions (≤85 psi). Electrical, gas and fluid lines were installed to enable remote operation of instrumentation under hyperbaric conditions, and to maintain viable biological samples with gas‐equilibrated superfusate and/or drugs. Systems were installed for vibration isolation and temperature regulation to maintain atomic force microscopy performance during compression and decompression. Results of atomic force microscopy testing demonstrate sub‐nanometre resolution at hyperbaric pressure in dry scans and fluid scans, in both contact mode and tapping mode. Noise levels were less when measurements were taken under hyperbaric pressure with air, helium (He) and nitrogen (N2). Atomic force microscopy and fluorescence microscopy measurements were made on a variety of living cell cultures exposed to hyperbaric gases (He, N2, O2, air). In summary, atomic force microscopy and fluorescence microscopy were installed and tested for use at hyperbaric pressures and enables the study of cellular and molecular effects of hyperbaric gases and pressure per se in biological preparations.
Human parvovirus PARV4 in plasma pools of Chinese origin
Authors: Ma Y.‐Y. , Guo Y. , Zhao X. , Wang Z. , Lv M.‐M. , Yan Q.‐P. , Zhang J.‐G.
Published: March 2012

Human parvovirus 4 (PARV4) is present in blood and blood products. As the presence and levels of PARV4 in Chinese source plasma pools have never been determined, we implemented real‐time quantitative PCR to investigate the presence of PARV4 in source plasma pools in China. Results showed that 26·15% (51/195) of lots tested positive for PARV4. The amounts of DNA ranged from 2·83 × 103 copies/ml to 2·35×107 copies/ml plasma. The high level of PARV4 in plasma pools may pose a potential risk to recipients. Further studies on the pathogenesis of PARV4 are urgently required.
Fire management and minesite rehabilitation in a frequently burnt tropical savanna
Authors: COOK GARRY DAVID
Published: March 2012

The interactions between vegetation dynamics, fuel dynamics and fire hazard in rehabilitation after bauxite mining at Gove, Northern Territory, Australia were investigated. It was found that a policy of fire exclusion had led to fuel loads of the oldest rehabilitation being three to four times greater than those of frequently burnt adjoining unmined landscapes. Consequently, the potential fire intensities are beyond those experienced elsewhere in the region. Where occasional fires have occurred in the rehabilitated areas, the proportion of tree death has varied, with the most severe cases having 43% to 70% mortality. In rehabilitated sites that have been burnt, the fuel loads are lower. These findings indicate that the fire hazard in the unburnt rehabilitation is extreme, but because not all sites had substantial tree death, there is potential to manage fuel loads with carefully planned fires. The paradigm of fire exclusion during the rehabilitation process is based on a long‐debunked forestry management paradigm which was applied to some Australian savanna landscapes and needs to be overturned to facilitate integration of the rehabilitation into the broader frequently burnt landscape.
Low local recurrence rates in young Asian patients with phyllodes tumours: less is more
Authors: Teo Jin Yao , Cheong Crystal Shuk‐Jin , Wong Chow Yin
Published: March 2012

Background:  Phyllodes tumours are increasingly being discovered incidentally in young patients after excision of a seemingly innocuous breast lump. The clinical course of this group of patients has not been well‐described, especially in the Asian population.

Methods:  A retrospective review of 44 consecutive patients below 25 years of age undergoing surgery for phyllodes tumours at our institution from 1992 to 2010 was conducted. Clinico‐pathological data, local recurrence rates and margin involvement were recorded.

Results:  The majority of the patients had benign lesions treated with simple enucleation, and there were no local recurrences documented after a mean and median length of follow‐up of 47.6 and 29.5 months, respectively.

Conclusion:  We conclude that in young Asian patients who present with benign phyllodes tumours, simple excision, followed by close follow‐up is sufficient, regardless of surgical margin status.
Short‐term and working memory skills in primary school‐aged children with specific language impairment and children with pragmatic language impairment: phonological, linguistic and visuo‐spatial aspects
Authors: Freed Jenny , Lockton Elaine , Adams Catherine
Published: March 2012

Background: Children with specific language impairment (CwSLI) are consistently reported to have short‐term memory (STM) and working memory (WM) difficulties.

Aim: To compare STM and WM abilities in CwSLI with children with pragmatic language impairment (CwPLI).

Methods & Procedures: Primary school‐aged CwSLI (n= 12) and CwPLI (n= 23) were assessed on measures of STM and WM.

Outcomes & Results: CwPLI had significantly higher scores than CwSLI on STM tasks, and this difference could not be accounted for by differences in receptive language ability. There were no between‐group differences for WM tasks. The majority of CwSLI and a significant proportion of CwPLI scored in the impaired range on each of the memory measures. In contrast, some CwPLI scored within the normal range.

Conclusions & Implications: CwPLI present with a different profile of STM but not WM ability to CwSLI. Clinical implications are discussed.
Social Identity, Groups, and Post‐Traumatic Stress Disorder
Authors: Muldoon Orla T. , Lowe Robert D.
Published: March 2012

As with the identification and labelling of many mental health problems, the adoption of PTSD within DSM can be said to arise from contemporaneous social and political contexts: specifically the return to the United States of many war‐affected veterans from Vietnam (Scott, 1993). The specific circumstances of the recognition of PTSD within DSM‐III have led several commentators to discuss it in terms of social construction (e.g., Summerfield, 2001). The current review argues that the orientation of theory and research aimed at understanding PTSD has been particularly informed by Western individualistic constructions of social phenomena. Our review calls for a blending of approaches to understanding post‐traumatic stress by considering the social structures and contexts in which it is expressed and in particular by considering how a group‐level analysis can inform incidence, diagnosis, and expression of post‐traumatic symptoms.
Blastic plasmacytoid dendritic cell neoplasm: a report of four cases and review of the literature
Authors: Borchiellini D. , Ghibaudo N. , Mounier N. , Del Giudice P. , Quinsat D. , Ticchioni M. , Perrin C. , Cardot Leccia N. , Lacour J.P.
Published: March 2012

Background  Blastic plasmacytoid dendritic cell neoplasm (BPDCN), formerly known as agranular CD4+/CD56+ haematodermic neoplasm (CD4/CD56 HN), is a rare distinct form of lymphoma‐like entity known of dermatologists because of its marked predilection for cutaneous involvement, and its aggressive behaviour. Moreover, the association or the evolution to an acute leukaemia entity that still expresses CD4 and CD56 markers is almost systematic. This new described entity of ‘CD4+/CD56+ leukaemia’ or ‘leukaemia of plasmacytoid dendritic cell lineage’ has a poor prognostic and may lead to include haematopoietic stem cell transplantation in the treatment strategy as early as possible.

Report of cases  We report here four cases presenting with skin lesions and haematological signs. One of the patients underwent allogeneic stem cell transplantation, with a relapse‐free survival of 40 months. We discuss the diagnosis features as well as the treatment options.

Conclusion  A collaborative work between dermatologists and onco‐haematologists is essential to give patients the best chance of complete and long‐term response.
Government Spending Shocks in Quarterly and Annual Time Series
Authors: BORN BENJAMIN , MÜLLER GERNOT J.
Published: March 2012

Government spending shocks are frequently identified in quarterly time‐series data by ruling out a contemporaneous response of government spending to other macroeconomic aggregates. We provide evidence that this assumption may not be too restrictive for annual time‐series data.
How Payday Credit Access Affects Overdrafts and Other Outcomes
Authors: MORGAN DONALD P. , STRAIN MICHAEL R. , SEBLANI IHAB
Published: March 2012

Despite a dozen studies, the welfare effects of payday credit are still debatable. We contribute new evidence to the debate by studying how payday credit access affects bank overdrafts (such as returned checks), bankruptcy, and household complaints against lenders and debt collectors. We find some evidence that Chapter 13 bankruptcy rates decrease after payday credit bans, but where we find that, we also find that complaints against lenders and debt collectors increase. The welfare implications of these offsetting movements are unclear. Our most robust finding is that returned check numbers and overdraft fee income at banks increase after payday credit bans. Bouncing a check may cost more than a payday loan, so this finding suggests that payday credit access helps households avoid costlier alternatives. While our findings obviously do not settle the welfare debate over payday lending, we hope they resolve it to some extent it by illuminating how households rearrange their financial affairs when payday loan supply changes.
Understanding Expectation‐Driven Fluctuations: A Labor‐Market Approach
Authors: WANG PENGFEI
Published: March 2012

This paper presents a unified analysis of neoclassical models that can generate expectation‐driven business cycles under anticipated future technology shocks (or news shocks). It shows that the ability or inability of various RBC models to generate positive comovement of aggregate variables hinges crucially on the structure of the labor market equilibrium. The analysis provides a simple and intuitive guide to understanding the existing literature and to searching for new models that can explain the data under news shocks.
Introducing the Elephant in the Room: Power
Authors: Jones Robert M.
Published: March 2012

“The ideal of fully absent power is not only impossible to achieve; it is even hard to envision. We are all the products of power relations and exercise power by our very presence in the world.”

—Jane Mansbridge, 2009
Don't Believe the Hype: Local Media Slant, Local Advertising, and Firm Value
Authors: GURUN UMIT G. , BUTLER ALEXANDER W.
Published: March 2012

When local media report news about local companies, they use fewer negative words compared to the same media reporting about nonlocal companies. We document that one reason for this positive slant is the firms' local media advertising expenditures. Abnormal positive local media slant strongly relates to firm equity values. The effect is stronger for small firms; firms held predominantly by individual investors; and firms with illiquid or highly volatile stock, low analyst following, or high dispersion of analyst forecasts. These findings show that news content varies systematically with the characteristics and conflicts of interest of the source.
Carry Trades and Global Foreign Exchange Volatility
Authors: MENKHOFF LUKAS , SARNO LUCIO , SCHMELING MAIK , SCHRIMPF ANDREAS
Published: March 2012

We investigate the relation between global foreign exchange (FX) volatility risk and the cross section of excess returns arising from popular strategies that borrow in low interest rate currencies and invest in high interest rate currencies, so‐called “carry trades.” We find that high interest rate currencies are negatively related to innovations in global FX volatility, and thus deliver low returns in times of unexpected high volatility, when low interest rate currencies provide a hedge by yielding positive returns. Furthermore, we show that volatility risk dominates liquidity risk and our volatility risk proxy also performs well for pricing returns of other portfolios.
Share Issuance and Factor Timing
Authors: GREENWOOD ROBIN , HANSON SAMUEL G.
Published: March 2012

We show that characteristics of stock issuers can be used to forecast important common factors in stocks' returns such as those associated with book‐to‐market, size, and industry. Specifically, we use differences between the attributes of stock issuers and repurchasers to forecast characteristic‐related factor returns. For example, we show that large firms underperform after years when issuing firms are large relative to repurchasing firms. While our strongest results are for portfolios based on book‐to‐market (i.e., HML), size (i.e., SMB), and industry, our approach is also useful for forecasting factor returns associated with distress, payout policy, and profitability.
Maintaining Participation and Momentum in Longitudinal Research Involving High‐Risk Families
Authors: Graziotti Ann L. , Hammond Jane , Messinger Daniel S. , Bann Carla M. , Miller‐Loncar Cynthia , Twomey Jean E. , Bursi Charlotte , Woldt Eunice , Ann Nelson Jay , Fleischmann Debra , Alexander Barbara
Published: March 2012

Purpose: The purpose of the current study was to identify and describe strategies available to optimize retention of a high‐risk research cohort and assist in the recovery of study participants following participant dropout.

Design and Methods: The Maternal Lifestyle Study (MLS), which investigated the effects of prenatal substance exposure (cocaine or opiates) on child outcome, is a prospective longitudinal follow‐up study that extended from birth through 15 years of age. Retention strategies to maximize participation and factors that might negatively impact compliance were examined over the course of five follow‐up phases.

Findings: At the conclusion of the 15‐year visits, MLS had successfully maintained compliance at 76%. Retention rates did not differ by exposure group.

Conclusions: Maintaining ongoing participation of enrolled study subjects is a critical element of any successful longitudinal study. Strategies that can be used to reengage and maintain participants in longitudinal research include persistence, flexibility with scheduling, home visits, long‐distance trips, increased incentives, and development of a computerized tracking system. Establishing rapport with families and ensuring confidentiality contributed to overall participant retention. The use of multiple tracking techniques is essential.

Clinical Relevance: Researchers are challenged to maintain participants in longitudinal studies to ensure the integrity of their research.
Occupational skin diseases
Authors: Diepgen Thomas L.
Published: March 2012

Occupational skin diseases are the most commonly reported notifiable occupational diseases. In Germany, 23 596 out of a total of 71 263 reported occupational diseases in 2010 were classified as occupational skin diseases (BK No. 5101: “severe or recurrent skin diseases which have forced the person to discontinue all occupational activities that caused or could cause the development, worsening, or recurrence of the disease”). Contact dermatitis (allergic, irritant) of the hands is the most common skin disease and atopic skin diathesis is often an important co‐factor. The number of work‐related skin diseases is many times higher than the number of notified occupational dermatoses. This CME article explains the legal framework of occupational diseases, the tasks and obligations of the legal statutory work insurance. Typical allergens and irritants of high risk professions are also presented as are the important steps from diagnosis to compensation. Early prevention of occupational skin diseases is very important to avoid severe chronic hand eczema. Therefore the “dermatologist's report” is crucial. Other occupational dermatoses (outside of BK 5101) are briefly mentioned. In recent years the number of notifications of occupational skin cancer due to occupational UV‐irradiation has increased. According to recent epidemiological findings, there is a significant and consistent positive association between occupational UV‐irradiation and squamous cell carcinoma. Therefore, an important criterion for a new occupational disease is fulfilled.
Estimating Classification Consistency and Accuracy for Cognitive Diagnostic Assessment
Authors: Cui Ying , Gierl Mark J. , Chang Hua‐Hua
Published: March 2012

This article introduces procedures for the computation and asymptotic statistical inference for classification consistency and accuracy indices specifically designed for cognitive diagnostic assessments. The new classification indices can be used as important indicators of the reliability and validity of classification results produced by cognitive diagnostic assessments. For tests with known or previously calibrated item parameters, the sampling distributions of the two new indices are shown to be asymptotically normal. To illustrate the computations of the new indices, we apply them to the real diagnostic data from a fraction subtraction test (Tatsuoka). We also use simulated data to evaluate their performances and distributional properties.
Assessing the Practical Equivalence of Conversions When Measurement Conditions Change
Authors: Liu Jinghua , Dorans Neil J.
Published: March 2012

At times, the same set of test questions is administered under different measurement conditions that might affect the psychometric properties of the test scores enough to warrant different score conversions for the different conditions. We propose a procedure for assessing the practical equivalence of conversions developed for the same set of test questions but administered under different measurement conditions. This procedure assesses whether the use of separate conversions for each condition has a desirable or undesirable effect. We distinguish effects due to differences in difficulty from effects due to rounding conventions. The proposed procedure provides objective empirical information that assists in deciding to report a common conversion for a set of items or a different conversion for the set of items when the set is administered under different measurement conditions. To illustrate the use of the procedure, we consider the case where a scrambled test form is used along with a base test form. If section order effects are detected between the scrambled and base forms, a decision needs to be made whether to report a single common conversion for both forms or to report separate conversions.
Can Health Care Rationing Ever Be Rational?
Authors: Gruenewald David A.
Published: March 2012

Mr. M. was a 77-year-old decisionally incapacitated long-term nursing home resident with chronic schizophrenia who was admitted to the hospital with a bacterial pneumonia. His past medical history was notable for deteriorating functional status over the past 2-3 years, urinary retention requiring chronic indwelling bladder catheterization, and two recent hospitalizations for urinary tract infections leading to sepsis. He developed respiratory failure soon after admission and was intubated and placed on mechanical ventilation. Follow-up studies suggested worsening pneumonia and acute respiratory distress syndrome (ARDS), as well as worsening kidney function.
Testing the Medical Covenant: Caring for Patients with Advanced Dementia
Authors: May William F.
Published: March 2012

A word, first, about the religious sensibility that I have found helpful to describe the care professionals owe to dying patients, particularly patients with advanced dementia.

That word is covenant. It is a biblical term; but, today, it covers such dubious devices as real estate covenants. A real estate covenant often operates below the moral level of a contract to wall some people out of a neighborhood. Classically understood, however, the word covenant helps probe the obligations of doctors to their patients more deeply than the notion of a contract. Covenants of the sort I have in mind and contracts appear to be first cousins; they both include an agreement and an exchange between parties. But, in spirit, contracts and covenants differ markedly. Contracts are external; covenants are internal to the parties involved. We sign contracts in order to discharge them expediently. Contracts are limited and time-bound — whether a contract to fix plumbing or to charge such and such for a medical procedure.
Doing the Right Thing: A Geriatrician's Perspective on Medical Care for the Person with Advanced Dementia
Authors: Gillick Muriel R.
Published: March 2012

America is aging. But even more striking than the rise in the proportion of the population over age 65 is the unprecedented number of individuals who are living into their eighties and nineties. While many people remain robust well into advanced age, the dramatic increase in the number of the oldest old has brought with it an epidemic of Alzheimer’s disease and other dementias. Dementia is a highly prevalent condition — currently 5.4 million Americans have Alzheimer’s disease, a number which may rise to 16 million by 2050 if there is no breakthrough in the prevention or treatment of the disease — but it disproportionately affects those over age 85, striking between one-third and one-half of this cohort. Developing a reasonable approach to the medical care of older people with dementia will be essential in the coming decades.
Morphological structure and peripheral innervation of the lateral line system in the Siberian sturgeon (Acipenser baerii)
Authors: SONG Wei , SONG Jiakun
Published: March 2012

Light and scanning electron microscopy (SEM) were used to study the epidermal lateral line system of the Siberian sturgeon (Acipenser baerii Brandt, 1869). This system consists of mechanoreceptive neuromasts, ampullae and the electroreceptive organ. The neuromasts are located in 5 pairs of cephalic and 1 pair of trunk canals and superficially in the middle and posterior pit lines that lie dorsomedially along the top of the skull immediately adjacent to the otic ampullae field. Both canal neuromasts and pit organ superficial neuromasts have opposite polarized hair cells that are parallel along the axis of the canal and pit line, respectively. However, they differ in both size and shape and in the density and length of the hair bundles. The ampullae are confined on the head, adjacent to the neuromast lines. The morphological structure of the ampullae in the Siberian sturgeon is similar to the ampullae in elasmobranchs and other primitive fish. Nevertheless, it has a relatively large mucus‐filled ampulla, and a shorter and narrower canal leading to a small opening to the outer epidermal surface. We also present new information concerning the peripheral innervation of lateral line receptors in sturgeons. The receptors of the lateral line system are innervated by 2 pairs of cranial nerves: anterior and posterior lateral line nerves. The peripheral processes of the anterior lateral line nerve form superficial ophthalmic, buccal, otic and anteroventral rami. The peripheral processes of the posterior lateral line nerve form middle, supratemporal and lateral rami.