bluuebunny/crossref_metadata_2025_split huggingface dataset:
The HtrA/DegP family protease MamE is a bifunctional protein with roles in magnetosome protein localization and magnetite biomineralization
Authors: Quinlan Anna , Murat Dorothée , Vali Hojatollah , Komeili Arash 
Published: March 2011

SummaryMagnetotactic bacteria contain nanometre‐sized, membrane‐bound organelles, called magnetosomes, which are tasked with the biomineralization of small crystals of the iron oxide magnetite allowing the organism to use geomagnetic field lines for navigation. A key player in this process is the HtrA/DegP family protease MamE. In its absence, Magnetospirillum magneticum str AMB‐1 is able to form magnetosome membranes but not magnetite crystals, a defect previously linked to the mislocalization of magnetosome proteins. In this work we use a directed genetic approach to find that MamE, and another predicted magnetosome‐associated protease, MamO, likely function as proteases in vivo. However, as opposed to the complete loss of mamE where no biomineralization is observed, the protease‐deficient variant of this protein still supports the initiation and formation of small, 20 nm‐sized crystals of magnetite, too small to hold a permanent magnetic dipole moment. This analysis also reveals that MamE is a bifunctional protein with a protease‐independent role in magnetosome protein localization and a protease‐dependent role in maturation of small magnetite crystals. Together, these results imply the existence of a previously unrecognized ‘checkpoint’ in biomineralization where MamE moderates the completion of magnetite formation and thus committal to magneto‐aerotaxis as the organism's dominant mode of navigating the environment.
An actin‐based cytoskeleton in archaea
Authors: Ettema Thijs J. G. , Lindås Ann‐Christin , Bernander Rolf 
Published: March 2011

SummaryIn eukaryotic and bacterial cells, spatial organization is dependent upon cytoskeletal filaments. Actin is a main eukaryotic cytoskeletal element, involved in key processes such as cell shape determination, mechanical force generation and cytokinesis. We describe an archaeal cytoskeleton which forms helical structures within Pyrobaculum calidifontis cells, as shown by in situ immunostaining. The core components include an archaeal actin homologue, Crenactin, closely related to the eukaryotic counterpart. The crenactin gene belongs to a conserved gene cluster denoted Arcade (actin‐related cytoskeleton in Archaea involved in shape determination). The phylogenetic distribution of arcade genes is restricted to the crenarchaeal Thermoproteales lineage, and to Korarchaeota, and correlates with rod‐shaped and filamentous cell morphologies. Whereas Arcadin‐1, ‐3 and ‐4 form helical structures, suggesting cytoskeleton‐associated functions, Arcadin‐2 was found to be localized between segregated nucleoids in a cell subpopulation, in agreement with possible involvement in cytokinesis. The results support a crenarchaeal origin of the eukaryotic actin cytoskeleton and, as such, have implications for theories concerning the origin of the eukaryotic cell.
Depositional processes of the Zhushadong and Mantou formations (Early to Middle Cambrian), Shandong Province, China: roles of archipelago and mixed carbonate–siliciclastic sedimentation on cycle genesis during initial flooding of the North China Platform
Authors: LEE HYUN SUK , CHOUGH SUNG KWUN 
Published: March 2011

AbstractTo understand the depositional processes and environmental changes during the initial flooding of the North China Platform, this study focuses on the Lower to Middle Cambrian Zhushadong and Mantou formations in Shandong Province, China. The succession in the Jinan and Laiwu areas comprises mixed carbonate and siliciclastic deposits composed of limestone, dolostone, stromatolite, thrombolite, purple and grey mudstone, and sandstone. A detailed sedimentary facies analysis of seven well‐exposed sections suggests that five facies associations are the result of an intercalation of carbonate and siliciclastic depositional environments, including local alluvial fans, shallowing‐upward carbonate–siliciclastic peritidal cycles, oolite dominant shoals, shoreface and lagoonal environments. These facies associations successively show a transition from an initially inundated tide‐dominated carbonate platform to a wave‐dominated shallow marine environment. In particular, the peritidal sediments were deposited during a large number of depositional cycles. These sediments consist of lime mudstone, dolomite, stromatolite and purple and grey mudstones. These shallowing‐upward cycles generally resulted from carbonate production in response to an increase of accommodation during rising sea‐level. The carbonate production was, however, interrupted by frequent siliciclastic input from the adjacent emergent archipelago. The depositional cycles thus formed under the influence of both autogenetic changes, including sediment supply from the archipelago, and allogenic control of relative sea‐level rise in the carbonate factory. A low‐relief archipelago with an active tidal regime allowed the development of tide‐dominated siliciclastic and carbonate environments on the vast platform. Siliciclastic input to these tidal environments terminated when most of the archipelago became submerged due to a rapid rise in sea‐level. This study provides insights on how a vast Cambrian carbonate platform maintained synchronous sedimentation under a tidal regime, forming distinct cycles of mixed carbonates and siliciclastics as the system kept up with rising relative sea‐level during the early stage of basin development in the North China Platform.
Actinomycetoma: dramatic response to modified two‐step regimen
Authors: Palit Aparna , Ragunatha Shivanna , Inamadar Arun C. 
Published: March 2011

AbstractMycetoma is a chronic granulomatous infection of the subcutaneous tissue caused by fungi or fungus‐like bacteria. The infection eventually spreads to bone resulting in significant morbidity. Rarely, viscera may be involved through contiguous spread. It is common in tropical countries like India, though disease is worldwide in distribution. A 22‐year‐old male patient, a farmer by occupation, presented with multiple discharging sinuses over the left chest wall, shoulder, upper arm, and adjacent neck of eight months duration. A diagnosis of actinomycetoma was made based on clinical and histopathological features as culture was negative for both fungus and bacteria. The patient was treated with a modified two‐step regimen. It consisted of an intensive phase with intravenous gentamicin 80 mg 12th hourly and cotrimoxazole 320/1600 mg twice daily orally for four weeks. This was followed by a maintenance phase with oral cotrimoxazole and doxycycline 100 mg twice daily. Patient showed excellent response with healing of all sinuses after two months of therapy. Involvement of covered parts of the body such as chest wall and shoulders is common in actinomycetoma compared to eumycetoma. Early institution of long‐term combination therapy with antimicrobials results in excellent outcome.
DNA‐based prenatal diagnosis of plectin‐deficient epidermolysis bullosa simplex associated with pyloric atresia
Authors: Nakamura Hideki , Natsuga Ken , Nishie Wataru , McMillan James R. , Nakamura Hiroyuki , Sawamura Daisuke , Akiyama Masashi , Shimizu Hiroshi 
Published: March 2011

AbstractBackground  Mutations in the plectin gene (PLEC) generally lead to epidermolysis bullosa simplex (EBS) associated with muscular dystrophy. It has been recently demonstrated that PLEC mutations can also cause a different clinical subtype, EBS associated with pyloric atresia (EBS‐PA), which shows early lethality. Prenatal diagnosis (PND) of EBS‐PA using mutation screening of PLEC has not been described.Objective  This study aimed to perform DNA‐based PND for an EBS‐PA family.Materials and methods  The EBS‐PA proband was compound‐heterozygous for a paternal c.1350G>A splice‐site mutation and a maternal p.Q305X nonsense mutation. Genomic DNA was obtained from amniocytes taken from an at‐risk fetus of the proband’s family. Direct sequencing and restriction enzyme digestion of polymerase chain reaction products from the genomic DNA were performed.Results  Mutational analysis showed that the fetus harbored both pathogenic mutations, suggesting that the fetus was a compound‐heterozygote and therefore affected with EBS‐PA. The skin sample obtained by autopsy from the abortus confirmed the absence of plectin expression at the dermal–epidermal junction.Conclusions  This is the first successful DNA‐based PND for an EBA‐PA family.
Should we say NO to body piercing in children? Complications after ear piercing in children
Authors: Fijałkowska Marta , Pisera Paweł , Kasielska Anna , Antoszewski Bogusław 
Published: March 2011

AbstractBackground  The popularity of body piercing procedures is increasing around the world. The trend for body ornamentation is not free from risks. The percentage of various complications following such procedures is growing. The aim of this paper is to present a rare complication after earlobe piercing, which happened to a child.Materials and methods  A 7‐year‐old girl was admitted to the Department of Plastic, Reconstructive and Aesthetic Surgery complaining of inflammatory lesions, caused by the presence of foreign bodies in both of her earlobes, which developed after the body piercing procedure. Her earlobes had been pierced in a beauty parlor six weeks earlier.Results  With regard to the child’s age, the embedded parts of the earrings were removed in the operating theatre. In our description, the hind parts of the earrings started to embed five weeks after the piercing procedure. Too strong and constant pressure caused by fixing clips led to skin ischemia, followed by inflammation and decubitus ulcer, and consequently to the penetration of clips into the earlobes.Conclusions  Complications after body piercing are observed in adults, as well as in children, in whom the decision of piercing performance should be carefully considered and rather postponed until self care is achievable.
Prevalence of infection by JC and BK polyomaviruses in kidney transplant recipients and patients with chronic renal disease
Authors: Pires E.P. , Bernardino‐Vallinoto C.V. , Alves D.M. , Migone S.R.C. , Machado L.F.A. , Ishak M.O.G. , Ishak R. , Cayres‐Vallinoto I.M.V. , Vallinoto A.C.R. 
Published: March 2011

E.P. Pires, C.V. Bernardino‐Vallinoto, D.M. Alves, S.R.C. Migone, L.F.A. Machado, M.O.G. Ishak, R. Ishak, I.M.V. Cayres‐Vallinoto, A.C.R. Vallinoto. Prevalence of infection by JC and BK polyomaviruses in kidney transplant recipients and patients with chronic renal disease. Transpl Infect Dis 2011: 13: 633–637. All rights reserved
Abstract: The present study investigated the prevalence of infection by JC and BK polyomaviruses (JCV and BKV) in patients with chronic renal disease (CRD), kidney transplant recipients, and a control group of asymptomatic subjects. We tested a total of 295 urine samples. After DNA extraction, polymerase chain reaction assay was used to amplify a fragment of 173 bp of the polyomavirus T antigen, followed by analysis using the BamHI restriction endonuclease. Infection by polyomavirus was detected in 17.6% (52/295 subjects) of the subjects. Whereas 30.5% (18/59) of transplant recipients were infected, the frequency was only 22.4% (30/134) in the control subjects, and 3.9% (4/102) in the CRD group (all JCV). The vast majority of infections (88.9%; 16/18) in transplant recipients were of the BKV type, whereas this type was absent in CRD patients, and made up only 10.0% (3/30) of infections in the control group. The risk of BKV infection was 72 times greater in renal transplant patients than in asymptomatic subjects. The low frequency of infection found in CRD patients may have been related to elevated levels of urea excreted in the urine, together with reduced urine volume and cell content. These factors may combine to reduce viral load or inhibit amplification. The results of the study indicate a need for the routine screening for polyomavirus in pre‐ and post‐transplant patients, as well as organ donors, considering that BKV infection has been associated with graft rejection in kidney transplants.
Allometry and sexually dimorphic traits in male anurans
Authors: SCHULTE‐HOSTEDDE A. I. , KUULA S. , MARTIN C. , SCHANK C. C. M. , LESBARRÈRES D. 
Published: March 2011

AbstractAllometry of secondary sexual traits has been the subject of recent debate, and the generality of positive allometry and its association with sexual selection have been recently questioned. Whereas some studies suggest an almost universal positive allometry for traits under sexual selection and isometry or a negative allometry for traits not under such pressure, other studies argue that this pattern results from the study of exaggerated (ornamental) traits. To answer the call for an examination of the allometry of less‐exaggerated sexually selected traits, we have examined morphological data from 14 sexually dimorphic traits and six monomorphic traits from three anuran species. Although we found evidence of positive allometry in male secondary sexual traits of several species and populations, not all nonsexual traits were isometric or exhibited negative allometry. Furthermore, our results indicate that larger traits in the populations that we studied were not associated with greater allometric slopes. Therefore, our study is in line with the contention suggesting no specific kind of allometric pattern for sexual and nonsexual characters, and we can only advocate for further investigation of trait allometry and sexual selection to understand the complexity underlying the evolution of allometry in sexual traits.
Neuroanatomical correlates of therapeutic efficacy of low‐frequency right prefrontal transcranial magnetic stimulation in treatment‐resistant depression
Authors: Kito Shinsuke , Hasegawa Takashi , Koga Yoshihiko 
Published: March 2011

Aims:  Low‐frequency transcranial magnetic stimulation (TMS) to the right prefrontal cortex has been shown to be effective in treatment‐resistant depression. The aim of the present study was to investigate changes in regional cerebral blood flow (rCBF) after low‐frequency right prefrontal stimulation (LFRS), and neuroanatomical correlates of therapeutic efficacy of LFRS in treatment‐resistant depression.Methods:  Twenty‐six patients with treatment‐resistant depression received five 60‐s 1‐Hz trains over the right prefrontal cortex, and 12 treatment sessions were administered during 3 weeks. Brain scans were acquired before and after LFRS using single photon emission computed tomography with 99mTc‐ethyl cysteinate dimer. Severity of depression was assessed on the Hamilton Depression Rating Scale (HDRS).Results:  Significant decreases in rCBF after LFRS were seen in the prefrontal cortex, orbitofrontal cortex, subgenual cingulate cortex, globus pallidus, thalamus, anterior and posterior insula, and midbrain in the right hemisphere. Therapeutic efficacy of LFRS was correlated with decreases in rCBF in the right prefrontal cortex, bilateral orbitofrontal cortex, right subgenual cingulate cortex, right putamen, and right anterior insula.Conclusion:  The antidepressant effects of LFRS in treatment‐resistant depression may be associated with decreases in rCBF in the orbitofrontal cortex and the subgenual cingulate cortex via the right prefrontal cortex.
Palliative resection of the primary tumour in stage IV rectal cancer
Authors: Verberne C. J. , de Bock G. H. , Pijl M. E. J. , Baas P. C. , Siesling S. , Wiggers T. 
Published: March 2011

AbstractAim  The aim of this study was to investigate the use of resection in a cohort of palliatively treated patients with stage IV rectal cancer. To avoid selection bias, particular attention was paid to correction for comorbidity and extent of disease.Method  Patients with stage IV rectal cancer in two hospitals in Groningen were consecutively included over a 5‐year period. Comorbidity was defined as major (dementia, cardiac failure or left ventricle ejection fraction < 30%, or severe chronic obstructive pulmonary disease), minor (diabetes, hypertension, mild renal disease or mild pulmonary disease) or none. The effect of patient and disease characteristics on survival was assessed using Kaplan–Meier and Cox regression analyses.Results  Of 88 patients, 11 (13%) underwent elective surgical resection without chemotherapy, 15 (17%) received both elective resection and chemotherapy, 21 (24%) underwent palliative chemotherapy only and 41 (47%) had supportive care only. The extent of disease (P < 0.01), hospital (P = 0.02) and comorbidity (P = 0.04) were correlated with worse survival. Patients treated surgically survived for longer than patients treated nonsurgically, when the data were corrected for age, comorbidity, extent of disease and hospital [hazard ratio (HR) = 0.4 (95% CI = 0.2–0.7)]. Perioperative morbidity was seen in 38% of the patients, and 30‐day mortality was 0%.Conclusion  In this retrospective cohort, resection was associated with longer survival independently of the extent of distant metastases, age and comorbidity.
A Time‐series Approach to the Feldstein–Horioka Puzzle with Panel Data from the OECD Countries
Authors: Kumar Saten , Bhaskara Rao B. 
Published: March 2011

AbstractThis paper estimates the Feldstein–Horioka equation from 1960–2007 with a panel of 13 OECD countries with the Pedroni method. It is found that the Feldstein–Horioka puzzle exists in a weaker form. Structural break tests indicated that there was a break in the mid‐1970s or in the early 1990s. These break dates seem to capture the effects of the last decade of the Bretton Woods agreement and the early years of the Maastricht agreement. In the post‐break periods, this relationship is weaker and the saving retention coefficient has declined, implying that capital mobility has increased between these OECD countries. It is likely that these two agreements may have decreased investor uncertainty and improved capital mobility. However, this conclusion should be interpreted cautiously because alternative explanations for the observed correlation between the saving–investment ratios are possible. For example, Byrne et al. (2009) have argued that the observed correlation between investment–saving ratios could be due to common global factors and therefore may not be useful for testing whether capital mobility has decreased or increased.
Quantitative Evaluation of the Determinants of Export and FDI: Firm‐level Evidence from Japan
Authors: Todo Yasuyuki 
Published: March 2011

AbstractUsing firm‐level data for Japan, this paper examines the determinants of the export and foreign direct investment (FDI) decision. We contribute to the literature by employing a mixed logit model, i.e. a multinomial logit model with random intercepts and random coefficients, to incorporate any unobserved firm heterogeneity and by paying special attention to the quantitative significance of the determinants. We find that while the impact of productivity on the export and FDI decision is positive and statistically significant, it is economically negligible. The effect of firm size, credit constraints and information spillovers from experienced firms is also small in magnitude. A quantitatively dominant determinant of the export and FDI decision is instead the prior status of firms in terms of internationalisation. In addition, the use of the mixed logit model enables us to find a substantial role of unobserved firm characteristics in internationalisation of the firm. These findings suggest that entry costs to foreign markets, which substantially vary in size across firms, play an important role in the export and FDI decision. In addition, given that the negligible effect of productivity and the dominant effect of prior status appear to be more prominent in Japan than in some other countries, this study helps highlight the uniqueness of Japanese firms.
A Vicious Cycle of Manias, Crises and Asymmetric Policy Responses – An Overinvestment View
Authors: Hoffmann Andreas , Schnabl Gunther 
Published: March 2011

AbstractOver the past three decades, we find that asymmetric policy responses heavily contributed to manias and bursting bubbles that eventually trapped the major industrial economies into near zero short‐term interest rates with rapidly rising public indebtedness. The article uses the endogenous business cycle theories of Wicksell, Mises, Schumpeter, Hayek and Minsky to show how ostensible counter‐cyclical monetary policies are asymmetric, as central banks are less willing to raise interest rates in booms than cut them when bubbles collapse. After interest rates have fallen towards zero, fiscal policy is called on which sooner or later becomes bounded by extraordinary debt to GDP ratios. Central banks hesitate to raise interest rates even in the face of a partial economic recovery because the cost of public debt service would become prohibitive. The economies then languish at very low interest rates that encourage low productivity real investments and a continual threat of bubbles in asset and raw material markets. This makes them unable to deal with further macroeconomic shocks.
Analysis of Subgroup Effects in Randomized Trials When Subgroup Membership is Missing: Application to the Second Multicenter Automatic Defibrillator Intervention Trial
Authors: Scharfstein Daniel , Onicescu Georgiana , Goodman Steven , Whitaker Rachel 
Published: March 2011

SummaryWe develop and implement a methodology for drawing inference about subgroup effects in a two-arm randomized trial when subgroup status is known only for a non-random sample in each of the trial arms. Since the subgroup effects are not point identified from the distribution of the observed data, we show how to compute bounds on these effects by using scientifically plausible assumptions. We characterize the uncertainty of our procedure by using the Bayesian paradigm. The methodology is developed in the context of the second Multicenter Automatic Defibrillator Intervention Trial, which was a randomized trial designed to evaluate the effectiveness of implantable defibrillators on survival.
Genetic variation in complement component C3 shows association with ischaemic stroke
Authors: Olsson S. , Stokowska A. , Holmegaard L. , Jood K. , Blomstrand C. , Pekna M. , Jern C. 
Published: March 2011

Background and purpose:  The aim of this study was to investigate whether genetic variation at the third complement component (C3) locus is associated with ischaemic stroke (IS).Methods:  The Sahlgrenska Academy Study on Ischaemic Stroke comprises 844 patients with IS, and 668 healthy controls. Sixteen SNPs were analyzed.Results:  Two SNPs, rs2277984 and rs3745565, showed a significant association with overall IS. The SNP rs2277984 also showed association with the IS subtype cryptogenic stroke. These associations were independent of hypertension, diabetes, and smoking. The independent association between rs3745565 and overall IS withstands correction for multiple testing.Conclusion:  In this sample of patients with IS, genetic variation in C3 is associated with IS.