Response of a ferrofluid to traveling-stripe forcing

We observe the dynamics of waves propagating on the surface of a ferrofluid under the influence of a spatially and temporarily modulated field. In particular, we excite plane waves by a travelling lamellar modulation of the magnetization. By this external driving both the wavelength and the propagation velocity of the waves can be controlled. The amplitude of the excited waves exhibits a resonance phenomenon similar to that of a forced harmonic oscillator. Its analysis reveals the dispersion relation of the free surface waves, from which the critical magnetic field for the onset of the Rosensweig instability can be extrapolated

Autosomal dominant hereditary spastic paraplegia: Novel mutations in the REEP1 gene (SPG31)

<p>Abstract</p> <p>Background</p> <p>Mutations in the <it>SPG4 </it>gene (spastin) and in the <it>SPG3A </it>gene (atlastin) account for the majority of 'pure' autosomal dominant form of hereditary spastic paraplegia (HSP). Recently, mutations in the <it>REEP1 </it>gene were identified to cause autosomal dominant HSP type SPG31. The purpose of this study was to determine the prevalence of <it>REEP1 </it>mutations in a cohort of 162 unrelated Caucasian index patients with 'pure' HSP and a positive family history (at least two persons per family presented symptoms).</p> <p>Methods</p> <p>162 patients were screened for mutations by, both, DHPLC and direct sequencing.</p> <p>Results</p> <p>Ten mutations were identified in the <it>REEP1 </it>gene, these included eight novel mutations comprising small insertions/deletions causing frame shifts and subsequently premature stop codons, one nonsense mutation and one splice site mutation as well as two missense mutations. Both missense mutations and the splice site mutation were not identified in 170 control subjects.</p> <p>Conclusion</p> <p>In our HSP cohort we found pathogenic mutations in 4.3% of cases with autosomal dominant inheritance. Our results confirm the previously observed mutation range of 3% to 6.5%, respectively, and they widen the spectrum of <it>REEP1 </it>mutations.</p

Interoperability for the design and construction industry through semantic web technology

The domain of architecture, engineering and construction (AEC) has experienced significant improvements with the advent of building information modelling (BIM) applications, which allow AEC specialists to model all information concerning a building design into one three-dimensional building model. Much of these improvements are however generated by the mere availability of such an environment, whereas many more improvements were expected by achieving an appropriate interoperability of information. We are investigating why such an interoperability is not reached fully and consider the semantic web as an alternative approach to reach the targeted interoperability. In this paper, an AEC description framework based on semantic web technology is presented and compared to the BIM approach, after which we indicate how it might solve the issue of interoperability more appropriately. Our evaluation of this investigation indicates the semantic web approach as a valid alternative approach, although considerably more research is needed to show it capable of providing the targeted interoperability of information in the AEC domain

Progress in Three-Dimensional Coherent X-Ray Diffraction Imaging

The Fourier inversion of phased coherent diffraction patterns offers images without the resolution and depth-of-focus limitations of lens-based tomographic systems. We report on our recent experimental images inverted using recent developments in phase retrieval algorithms, and summarize efforts that led to these accomplishments. These include ab-initio reconstruction of a two-dimensional test pattern, infinite depth of focus image of a thick object, and its high-resolution (~10 nm resolution) three-dimensional image. Developments on the structural imaging of low density aerogel samples are discussed.Comment: 5 pages, X-Ray Microscopy 2005, Himeji, Japa

An assessment of the resolution limitation due to radiation-damage in x-ray diffraction microscopy

X-ray diffraction microscopy (XDM) is a new form of x-ray imaging that is being practiced at several third-generation synchrotron-radiation x-ray facilities. Although only five years have elapsed since the technique was first introduced, it has made rapid progress in demonstrating high-resolution threedimensional imaging and promises few-nm resolution with much larger samples than can be imaged in the transmission electron microscope. Both life- and materials-science applications of XDM are intended, and it is expected that the principal limitation to resolution will be radiation damage for life science and the coherent power of available x-ray sources for material science. In this paper we address the question of the role of radiation damage. We use a statistical analysis based on the so-called "dose fractionation theorem" of Hegerl and Hoppe to calculate the dose needed to make an image of a lifescience sample by XDM with a given resolution. We conclude that the needed dose scales with the inverse fourth power of the resolution and present experimental evidence to support this finding. To determine the maximum tolerable dose we have assembled a number of data taken from the literature plus some measurements of our own which cover ranges of resolution that are not well covered by reports in the literature. The tentative conclusion of this study is that XDM should be able to image frozen-hydrated protein samples at a resolution of about 10 nm with "Rose-criterion" image quality.Comment: 9 pages, 4 figure

T-cell subpopulations αβ and γδ in cord blood of very preterm infants : The influence of intrauterine infection

Open Access: This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are creditedPreterm infants are very susceptible to infections. Immune response mechanisms in this group of patients and factors that influence cord blood mononuclear cell populations remain poorly understood and are considered insufficient. However, competent immune functions of the cord blood mononuclear cells are also described. The aim of this work was to evaluate the T-cell population (CD3+) with its subpopulations bearing T-cell receptor (TCR) αβ or TCR γδ in the cord blood of preterm infants born before 32 weeks of gestation by mothers with or without an intrauterine infection. Being a pilot study, it also aimed at feasibility check and assessment of an expected effect size. The cord blood samples of 46 infants age were subjected to direct immunofluorescent staining with monoclonal antibodies and then analyzed by flow cytometry. The percentage of CD3+ cells in neonates born by mothers with diagnosis of intrauterine infection was significantly lower than in neonates born by mothers without infection (p = 0.005; Mann-Whitney U test). The number of cells did not differ between groups. Infection present in the mother did not have an influence on the TCR αβ or TCR γδ subpopulations. Our study contributes to a better understanding of preterm infants' immune mechanisms, and sets the stage for further investigations.Peer reviewedFinal Published versio

The impact of late treatment-toxicity on generic health-related quality of life in head and neck cancer patients after radiotherapy

SummaryTo examine the impact of late treatment-related xerostomia and dysphagia on health-related quality of life (HRQOL) in head and neck cancer (HNC) patients after radiotherapy. A multi-center cross-sectional survey was performed. Patients with a follow-up of at least 6months after curative radiotherapy, without evidence of recurrent disease were eligible for inclusion. The Euroqol-5D questionnaire (EQ-5D) was filled out and toxicity was scored and converted to the RTOG scale. The EQ-5D measures generic HRQOL in terms of utility and visual analogue scale (VAS) scores. Missing data on the EQ-5D were imputed using multiple imputation. HRQOL was compared between subgroups of patients with and without toxicity. Subsequently, the impact of xerostomia and dysphagia on HRQOL was analyzed using multivariate regression analyses. Both analyses were performed separately for utility scores and VAS scores. The study population was composed of 396 HNC patients. The average utility and VAS scores were 0.85 (scale 0–1) and 75 (scale 0–100). Subgroups of patients with xerostomia and/or dysphagia showed statistically significantly lower utility and VAS scores (P=0.000–0.022). The multivariate regression model showed that xerostomia and dysphagia were negative predictors of both utility and VAS scores. Other factors which influenced HRQOL in at least one of the two regression models were: sex, tumor location and the addition of surgery to radiotherapy. Xerostomia and dysphagia diminish generic HRQOL. Moreover dysphagia affects patients’ HRQOL stronger than xerostomia

Mechanistic basis of an epistatic interaction reducing age at onset in hereditary spastic paraplegia

Many genetic neurological disorders exhibit variable expression within affected families, often exemplified by variations in disease age at onset. Epistatic effects (i.e. effects of modifier genes on the disease gene) may underlie this variation, but the mechanistic basis for such epistatic interactions is rarely understood. Here we report a novel epistatic interaction between SPAST and the contiguous gene DPY30, which modifies age at onset in hereditary spastic paraplegia, a genetic axonopathy. We found that patients with hereditary spastic paraplegia caused by genomic deletions of SPAST that extended into DPY30 had a significantly younger age at onset. We show that, like spastin, the protein encoded by SPAST, the DPY30 protein controls endosomal tubule fission, traffic of mannose 6-phosphate receptors from endosomes to the Golgi, and lysosomal ultrastructural morphology. We propose that additive effects on this pathway explain the reduced age at onset of hereditary spastic paraplegia in patients who are haploinsufficient for both genes.This work was supported by grants to E.R.; Project Grant from United States Spastic Paraplegia Foundation, UK Medical Research Council Project Grant [MR/M00046X/1], Project grant from NIHR Biomedical Research Centre at Addenbrooke’s Hospital, Wellcome Trust Senior Research Fellowship in Clinical Science [082381], Project Grant from Tom Wahlig Stiftung (project 33). J.E. and P.M. are supported by a Wellcome Trust Principal Research Fellowship Grant to Margaret S. Robinson [086598]. T.M.N. was supported by an MRC PhD studentship [G0800117]. B.W. is supported by the Tom Wahlig Advanced Fellowship, the German Federal Ministry of Education and Research (BMBF, 01GQ113), the Bavarian Ministry of Education and Culture, Sciences and Arts in the framework of the Bavarian Molecular Biosystems Research Network and ForIPS, and the Interdisciplinary Centre for Clinical Research (IZKF, University Hospital of Erlangen, N3 and F3). T.R. was supported by research grant DFG GRK2162/1 of the Deutsche Forschungsgemeinschaft. The study was also supported by the European Union within the 7th European Community Framework Program for Research and Technological Development through funding for the NEUROMICS network (F5-2012-305121 to L.S. and A.D.), the E-Rare Network NEUROLIPID (01GM1408B to R.S. and ANR-13-RARE-0003-02 to G.S.), and a Marie Curie International Outgoing Fellowship (grant PIOF-GA-2012-326681 to R.S. and L.S.). This work was further supported by the US National Institutes of Health (NIH) (grant 5R01NS072248 to R.S.), the German HSP-Selbsthilfegruppe e.V. (grant to R.S. and L.S.), and grants to C.B.: Project Grant from Tom Wahlig Stiftung (project 20), grant from the Stiftung für Pathobiochemie und Molekulare Diagnostik. CIMR is supported by a Wellcome Trust Strategic Award [100140] and Equipment Grant [093026]