17 research outputs found
Events with Isolated Charged Leptons and Large Missing Transverse Momentum at HERA
Striking events with isolated charged leptons, large missing transverse
momentum and large transverse momentum of the hadronic final state were
observed at the electron proton collider HERA in a data sample corresponding to
a luminosity of about 130 pb-1. The H1 collaboration observed 11 events with
isolated electrons or muons and with transverse momentum above 25 GeV. Only
3.4+-0.6 events were expected from Standard Model (SM) processes. Six of these
events have a transverse momentum of greater than 40 GeV, while 1.3+-0.3 events
were expected. The ZEUS collaboration observed good agreement with the SM.
However, ZEUS found two events with a similar event topology, but tau leptons
instead of electrons or muons in the final state. Only 0.2+-0.05 events were
expected from SM processes. For various hypotheses the compatibility of the
experimental results was investigated with respect to the SM and with respect
to possible explanations beyond the SM. Prospects for the high-luminosity
HERA-II data taking period are given
Giant intradiploic epidermoid cyst with large osteolytic lesions of the skull: a case report
<p>Abstract</p> <p>Introduction</p> <p>We report a case of tumor growth over a period of four decades, presenting with large multicentric lytic lesions of the skull and a profound mass effect, without neurological deficits. Clinical and radiological features of a patient with a giant intradiploic epidermoid and its impact on the choice of treatments are discussed.</p> <p>Case presentation</p> <p>An 81-year-old Caucasian man, who had first noticed a painless subcutaneous swelling over the left frontal scalp about 40 years ago, presented after a short episode of dizziness, which he experienced after treatment of focal retinal detachment. Computed tomography (CT) and magnetic resonance imaging (MRI) examinations revealed an exceptionally large tumor involving major parts of the skull with extensive destruction of the bone and distinct deformation of the brain. Considering his age and the absence of neurological deficits or pain, the patient refused the option of tumor removal and cranioplasty, yet agreed to a biopsy, which confirmed the suspected diagnosis.</p> <p>Conclusions</p> <p>The course of the disease demonstrates that even patients with large tumors, inducing distinct pathomorphological changes, do not necessarily experience significant impairment of their quality of life without surgery. This is an impressive example of the chance to lead a long and satisfying life without specific medical treatment, avoiding the inherent risks of these procedures. Yet, there is a clear indication for surgery of intradiploic epidermoids in most cases described in the literature.</p
Scientific Software – Publish, Cite, and get Credit for your Code
Scientific software takes on an increasingly prominent role in research. In particular in the
sciences software has become an indispensable element in the research process. The way we
handle software has a significant influence on the quality of research results, their traceability and
reproducibility.
In order to strengthen the recognition of scientific results achieved by software and to improve its
visibility, the scientific community is actively working on concepts and solutions enabling
researchers to publish software, cite it and be credited for it.
For software to be a valuable and citeable contribution to science, the publication of scientific
software must meet the quality criteria of the scientific discourse. As with data publication, defined
processes and persistent identifiers should be used to make the results of research reproducible.
Also, the specific needs of research have to be addressed and joined with experience gained in
the field of development of free and open source software. A common understanding of handling
scientific software with defined processes must be developed jointly. These processes have to
address questions regarding quality assurance, versioning and documentation, traceability,
reproducibility and reusability. Furthermore, the archiving of source code and executables, the use
of persistent identifiers, and metrics measuring productivity, impact, and recognition have to be
addressed.
Especially when looking at software in the context of scientific publications only insufficient
solutions exist to date. Even though it is possible to mint DOIs to identify archived source code
copies, quality ensured by reviews is not addressed properly. But deserving credit for a software
publication requires measures assessing the value of the published software. Subjectspecific
reviews paired with softwarespecific expertise would open up new possibilities leveraging
interdisciplinarity and the interplay of complementary scientific fields such as geosciences and
computer science. Thus software publications and properly arranged reviews would foster the
exchange in order to establish best practices from computer science in geosciences and to
enhance subjectspecific software successively after its original publication
Publishing Platform for Scientific Software –Lessons Learned –
Scientific software has become an indispensable commodity for the production, processing and analysis of
empirical data but also for modelling and simulation of complex processes. Software has a significant influence
on the quality of research results. For strengthening the recognition of the academic performance of scientific
software development, for increasing its visibility and for promoting the reproducibility of research results,
concepts for the publication of scientific software have to be developed, tested, evaluated, and then transferred into
operations. For this, the publication and citability of scientific software have to fulfil scientific criteria by means
of defined processes and the use of persistent identifiers, similar to data publications.
The SciForge project is addressing these challenges. Based on interviews a blueprint for a scientific software
publishing platform and a systematic implementation plan has been designed. In addition, the potential
of journals, software repositories and persistent identifiers have been evaluated to improve the publication and
dissemination of reusable software solutions. It is important that procedures for publishing software as well as
methods and tools for software engineering are reflected in the architecture of the platform, in order to improve the
quality of the software and the results of research. In addition, it is necessary to work continuously on improving
specific conditions that promote the adoption and sustainable utilization of scientific software publications. Among
others, this would include policies for the development and publication of scientific software in the institutions but
also policies for establishing the necessary competencies and skills of scientists and IT personnel.
To implement the concepts developed in SciForge a combined bottom-up / top-down approach is considered
that will be implemented in parallel in different scientific domains, e.g. in earth sciences, climate research and
the life sciences. Based on the developed blueprints a scientific software publishing platform will be iteratively
implemented, tested, and evaluated. Thus the platform should be developed continuously on the basis of gained
experiences and results. The platform services will be extended one by one corresponding to the requirements of
the communities. Thus the implemented platform for the publication of scientific software can be improved and
stabilized incrementally as a tool with software, science, publishing, and user oriented features
The influence of lumbar spinal drainage on diffusion parameters in patients with suspected normal pressure hydrocephalus using 3T MRI
Background: Normal pressure hydrocephalus (NPH) has been an ongoing and challenging field of research for the past decades because two main issues are still not fully understood: the pathophysiologic mechanisms underlying ventricular enlargement and prediction of outcome after surgery. Purpose: To evaluate changes in diffusion tensor imaging (DTI) derived parameters in patients with suspected normal pressure hydrocephalus before and after withdrawal of cerebrospinal fluid (CSF). Material and Methods: Twenty-four consecutive patients with clinical and radiological suspicion of NPH and 14 agematched control subjects were examined with DTI on a clinical 3T scanner. Patients were examined before and 6–36 h after CSF drainage (interval between scans, 5 days). Fifteen patients were finally included in data analysis. Fractional anisotropy (FA) and mean, parallel, and radial diffusivity (MD, PD, RD) were evaluated using a combination of a ROI-based approach and a whole-brain voxel-by-voxel analysis. Results: Alteration of DTI parameters in patients with suspected NPH is regionally different. Compared to the control group, we found an elevation of FA in the subcortical white matter (SCWM) and corpus callosum, whereas the other diffusion parameters showed an increase throughout the brain in variable extent.We also found a slight normalization of RD in the SCWM in patients after lumbar drainage. Conclusion: Our results show that DWI parameters are regionally dependent and reflect multifactorial (patho-) physiological mechanisms, which need to be interpreted carefully. It seems that improvement of gait is caused by a decrease of interstitial water deposition in the SCWM
Automated neurosurgery for deep brain stimulation: Presentation held at International Disabled People's Day; Healthy Children - Healthy Europe, 15th-17th March 2018, Zgorzelec
Background: Deep brain stimulation (DBS) has become a reliable method in the treatment of motional disorders, e.g., Idiopathic Parkinson’s disease (IPD). DBS is technically based on stereotaxy. The Starfix®-platform is a new type of stereotactic frame that allows for an individualized and patient-optimized therapeutic regimen in IPD. Objectives: The aim of this study is to retrospectively compare the outcomes of IPD patients that underwent surgery with the use of conventional stereotactic frames (31 patients) to those that underwent implantation of DBS with the use of Starfix® frames (29 patients). Material and methods: Surgery time, UPDRS/ III, L-dopa and L-dopa equivalent dose (LED) were compared prior to surgery as well as 4weeks, 12 weeks, 6 months and one year post-operatively. Results: IPD-related symptoms improved significantly in both groups, concerning the UPDRS/III (conventional 69.5% vs.72.4% Starfix®). After surgery, a significant reduction of L-dopa and LED was seen in both groups. Inherent advantages of the Starfix®-platform include simultaneous positioning of the stimulating electrodes and a significant reduction in surgical time. Conclusions: In summary, both stereotactic procedures are reliably safe procedures for the placement of stimulating electrodes as well as the stimulation effect achieved. The logistical disconnection of pre-surgical planning and surgical therapy emphasizes the benefits of the individualized stereotactic procedure
Detection of novel genomic aberrations in anaplastic astrocytomas by GTG-banding, SKY, locus-specific FISH, and high density SNP-array
Astrocytomas represent the largest and most common subgroup of brain tumors. Anaplastic astrocytoma (WHO grade III) may arise from low-grade diffuse astrocytoma (WHO grade II) or as primary tumors without any precursor lesion. Comprehensive analyses of anaplastic astrocytomas combining both cytogenetic and molecular cytogenetic techniques are rare.Therefore, we analyzed genomic alterations of five anaplastic astrocytomas using high-density single nucleotide polymorphism arrays combined with GTG-banding and FISH-techniques.By cytogenetics, we found 169 structural chromosomal aberrations most frequently involving chromosomes 1, 2, 3, 4, 10, and 12, including two not previously described alterations, a nonreciprocal translocation t(3;11)(p12;q13), and one interstitial chromosomal deletion del(2)(q21q31).Additionally, we detected previously not documented loss of heterozygosity (LOH) without copy number changes in 4/5 anaplastic astrocytomas on chromosome regions 5q11.2, 5q 22.1, 6q21, 7q21.11, 7q31.33, 8q11.22, 14q21.1, 17q21.31, and 17q22, suggesting segmental uniparental disomy (UPD), applying high-density single nucleotide polymorphism arrays.UPDs are currently considered to play an important role in the initiation and progression of different malignancies. The significance of previously not described genetic alterations in anaplastic astrocytomas presented here needs to be confirmed in a larger series
Three gangliogliomas: Results of GTG-banding, SKY, genome-wide high resolution SNP-array, gene expression and review of the literature
According to the World Health Organization gangliogliomas are classified as well-differentiated and slowly growing neuroepithelial tumors, composed of neoplastic mature ganglion and glial cells. It is the most frequent tumor entity observed in patients with long-term epilepsy. Comprehensive cytogenetic and molecular cytogenetic data including high-resolution genomic profiling (single nucleotide polymorphism (SNP)-array) of gangliogliomas are scarce but necessary for a better oncological understanding of this tumor entity. For a detailed characterization at the single cell and cell population levels, we analyzed genomic alterations of three gangliogliomas using trypsin-Giemsa banding (GTG-banding) and by spectral karyotyping (SKY) in combination with SNP-array and gene expression array experiments. By GTG and SKY, we could confirm frequently detected chromosomal aberrations (losses within chromosomes 10, 13 and 22; gains within chromosomes 5, 7, 8 and 12), and identify so far unknown genetic aberrations like the unbalanced non-reciprocal translocation t(1;18)(q21;q21). Interestingly, we report on the second so far detected ganglioglioma with ring chromosome 1. Analyses of SNP-array data from two of the tumors and respective germline DNA (peripheral blood) identified few small gains and losses and a number of copy-neutral regions with loss of heterozygosity (LOH) in germline and in tumor tissue. In comparison to germline DNA, tumor tissues did not show substantial regions with significant loss or gain or with newly developed LOH. Gene expression analyses of tumor-specific genes revealed similarities in the profile of the analyzed samples regarding different relevant pathways. Taken together, we describe overlapping but also distinct and novel genetic aberrations of three gangliogliomas