Festschrift 25 Jahre Fachgebiet Maschinenelemente und Mechanik, Technische Hochschule Darmstadt

Festschrift 25 Jahre Fachgebiet Maschinenelemente und Mechanik, Technische Hochschule Darmstadt Leiter Prof. Dr.-Ing. Walter Raab. Kolloquium am 13. September 1991, Darmstad

Newly defined ATP-binding cassette subfamily B member 5 positive dermal mesenchymal stem cells promote healing of chronic iron-overload wounds via secretion of interleukin-1 receptor antagonist

In this study, we report the beneficial effects of a newly identified dermal cell subpopulation expressing the ATP‐binding cassette subfamily B member 5 (ABCB5) for the therapy of nonhealing wounds. Local administration of dermal ABCB5+‐derived mesenchymal stem cells (MSCs) attenuated macrophage‐dominated inflammation and thereby accelerated healing of full‐thickness excisional wounds in the iron‐overload mouse model mimicking the nonhealing state of human venous leg ulcers. The observed beneficial effects were due to interleukin‐1 receptor antagonist (IL‐1RA) secreted by ABCB5+‐derived MSCs, which dampened inflammation and shifted the prevalence of unrestrained proinflammatory M1 macrophages toward repair promoting anti‐inflammatory M2 macrophages at the wound site. The beneficial anti‐inflammatory effect of IL‐1RA released from ABCB5+‐derived MSCs on human wound macrophages was conserved in humanized NOD‐scid IL2rγ null mice. In conclusion, human dermal ABCB5+ cells represent a novel, easily accessible, and marker‐enriched source of MSCs, which holds substantial promise to successfully treat chronic nonhealing wounds in humans

Discovery of X-ray burst triplets in EXO 0748-676

[Abridged] Type-I X-ray bursts are thermonuclear flashes that take place on the surface of accreting neutron stars. The wait time between consecutive bursts is set by the time required to accumulate the fuel needed to trigger a new burst; this is at least one hour. Sometimes secondary bursts are observed, approximately 10 min after the main burst. These short wait-time bursts are not yet understood. We observed the low-mass X-ray binary and X-ray burster EXO 0748-676 with XMM-Newton for 158 h, during 7 uninterrupted observations lasting up to 30 h each. We detect 76 X-ray bursts. Most remarkably, 15 of these bursts occur in burst triplets, with wait times of 12 min between the three components of the triplet. We also detect 14 doublets with similar wait times between the two components of the doublet. The characteristics of the bursts indicate that possibly all bursts in this system are hydrogen-ignited, in contrast with most other frequent X-ray bursters in which bursts are helium-ignited, but consistent with the low mass accretion rate in EXO 0748-676. Possibly the hydrogen ignition is the determining factor for the occurrence of short wait-time bursts.Comment: 23 pages, 16 figures, accepted for publication in A&

“I attend at Vanguard and I attend here as well”: barriers to accessing healthcare services among older South Africans with HIV and non-communicable diseases

Background: HIV and non-communicable disease (NCD) are syndemic within sub-Saharan Africa especially among older persons. The two epidemics interact with one another within a context of poverty, inequality and inequitable access to healthcare resulting in an increase in those aged 50 and older living with HIV and experiencing an NCD comorbidity. We explore the challenges of navigating healthcare for older persons living with HIV and NCD co-morbidity. Methods: In-depth semi-structured interviews were conducted with a small sample of older persons living with HIV (OPLWH). The perspectives of key informants were also sought to triangulate the evidence of OPLWH. The research took place in two communities on the outskirts of Cape Town, South Africa. All interviews were conducted by a trained interviewer and transcribed and translated for analysis. Thematic content analysis guided data analysis. Results: OPLWH experienced an HIV-NCD syndemic. Our respondents sought care and accessed treatment for both HIV and other chronic (and acute) conditions, though these services were provided at different health facilities or by different health providers. Through the syndemic theory, it is possible to observe that OPLWH and NCDs face a number of physical and structural barriers to accessing the healthcare system. These barriers are compounded by separate appointments and spaces for each condition. These difficulties can exacerbate the impact of their ill-health and perpetuate structural vulnerabilities. Despite policy changes towards integrated care, this is not the experience of OPLWH in these communities. Conclusions: The population living with HIV is aging increasing the likelihood that those living with HIV will also be living with other chronic conditions including NCDs. Thus, it is essential that health policy address this basic need to integrate HIV and NCD care

A Genome-Wide Survey of Switchgrass Genome Structure and Organization

The perennial grass, switchgrass (Panicum virgatum L.), is a promising bioenergy crop and the target of whole genome sequencing. We constructed two bacterial artificial chromosome (BAC) libraries from the AP13 clone of switchgrass to gain insight into the genome structure and organization, initiate functional and comparative genomic studies, and assist with genome assembly. Together representing 16 haploid genome equivalents of switchgrass, each library comprises 101,376 clones with average insert sizes of 144 (HindIII-generated) and 110 kb (BstYI-generated). A total of 330,297 high quality BAC-end sequences (BES) were generated, accounting for 263.2 Mbp (16.4%) of the switchgrass genome. Analysis of the BES identified 279,099 known repetitive elements, >50,000 SSRs, and 2,528 novel repeat elements, named switchgrass repetitive elements (SREs). Comparative mapping of 47 full-length BAC sequences and 330K BES revealed high levels of synteny with the grass genomes sorghum, rice, maize, and Brachypodium. Our data indicate that the sorghum genome has retained larger microsyntenous regions with switchgrass besides high gene order conservation with rice. The resources generated in this effort will be useful for a broad range of applications

Towards Analyzing Security-Critical Software During Development

We describe an approach and tool for analyzing the vulnerability of software applications to anomalous events and malicious threats during software development. Traditionally, security analysis has been applied at the network system level, after release, using tiger team approaches. After a successful tiger team penetration, specific system vulnerabilities are patched. We make a case for applying software engineering analysis techniques that have proven successful in the software safety arena to security-critical software code. This work is based on the generally held belief that a large proportion of security violations result from errors introduced during software development. Our methodology employs software fault injection and automatic input generation to force anomalous program states while a piece of software is executing, in order to determine where it is most vulnerable. A software developer or security analyst can specify what constitutes a security policy violation for the s..

Festschrift 25 Jahre Fachgebiet Maschinenelemente und Mechanik, Technische Hochschule Darmstadt

Festschrift 25 Jahre Fachgebiet Maschinenelemente und Mechanik, Technische Hochschule Darmstadt Leiter Prof. Dr.-Ing. Walter Raab. Kolloquium am 13. September 1991, Darmstad