273 research outputs found
Einstellung junger Hochschulkader zum Leistungsprinzip und zur beschleunigten Durchsetzung der wissenschaftlich-technischen Revolution: spezieller Bericht zu SIS 7
"Der vorliegende Bericht beinhaltet Aussagen von Hochschulabsolventen zur Durchsetzung des Leistungsprinzips und zur Beschleunigung des wissenschaftlich-technichen Fortschritts. Es handelt sich dabei meist um offene Fragen ohne Antwortvorgaben. Die Absolventen waren zum Zeitpunkt der Befragung ca. 10 Jahre in der Praxis tätig." Insgesamt wurden 227 in der Industrie tätige Hochschulabsolventen befragt. Es zeigt sich, daß diese in der Mehrheit dem Leistungsprinzip positiv gegenüber stehen. Weiterhin werde viel Unzufriedenheit über Erscheinungen des sozialen Alltags in der DDR von den Hochschulabsolventen reflektiert. "Die starke Orientierung auch vieler Hochschulabsolventen auf Fragen der Versorgung mit Konsumgütern und Dienstleistungen überdeckt manche andere Bedürfnisse etwas." (psz
Ultrafast nonlocal control of spontaneous emission
Solid-state cavity quantum electrodynamics systems will form scalable nodes
of future quantum networks, allowing the storage, processing and retrieval of
quantum bits, where a real-time control of the radiative interaction in the
cavity is required to achieve high efficiency. We demonstrate here the dynamic
molding of the vacuum field in a coupled-cavity system to achieve the ultrafast
nonlocal modulation of spontaneous emission of quantum dots in photonic crystal
cavities, on a timescale of ~200 ps, much faster than their natural radiative
lifetimes. This opens the way to the ultrafast control of semiconductor-based
cavity quantum electrodynamics systems for application in quantum interfaces
and to a new class of ultrafast lasers based on nano-photonic cavities.Comment: 15 pages, 4 figure
Feeding of the probiotic bacterium Enterococcus faecium NCIMB 10415 differentially affects shedding of enteric viruses in pigs
Effects of probiotic bacteria on viral infections have been described
previously. Here, two groups of sows and their piglets were fed with or
without feed supplementation of the probiotic bacterium Enterococcus faecium
NCIMB 10415. Shedding of enteric viruses naturally occurring in these pigs was
analyzed by quantitative real-time RT-PCR. No differences between the groups
were recorded for hepatitis E virus, encephalomyocarditis virus and norovirus.
In contrast, astrovirus was exclusively detected in the non-supplemented
control group. Rotavirus was shedded later and with lower amounts in the
probiotic piglet group (p < 0.05); rotavirus-shedding piglets gained less
weight than non-infected animals (p < 0.05). Serum titres of anti-rotavirus
IgA and IgG antibodies were higher in piglets from the control group, whereas
no difference was detected between sow groups. Phenotype analysis of immune
cell antigens revealed significant differences of the CD4 and CD8β (p < 0.05)
as well as CD8α and CD25 (p < 0.1) T cell populations of the probiotic
supplemented group compared to the non-supplemented control group. In
addition, differences were evident for CD21/MHCII-positive (p < 0.05) and IgM-
positive (p < 0.1) B cell populations. The results indicate that probiotic
bacteria could have effects on virus shedding in naturally infected pigs,
which depend on the virus type. These effects seem to be caused by
immunological changes; however, the distinct mechanism of action remains to be
elucidated
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Aspects of high hydrostatic pressure food processing: Perspectives on technology and food safety
The last two decades saw a steady increase of high hydrostatic pressure (HHP) used for treatment of foods. Although the science of biomaterials exposed to high pressure started more than a century ago, there still seem to be a number of unanswered questions regarding safety of foods processed using HHP. This review gives an overview on historical development and fundamental aspects of HHP, as well as on potential risks associated with HHP food applications based on available literature. Beside the combination of pressure and temperature, as major factors impacting inactivation of vegetative bacterial cells, bacterial endospores, viruses, and parasites, factors, such as food matrix, water content, presence of dissolved substances, and pH value, also have significant influence on their inactivation by pressure. As a result, pressure treatment of foods should be considered for specific food groups and in accordance with their specific chemical and physical properties. The pressure necessary for inactivation of viruses is in many instances slightly lower than that for vegetative bacterial cells; however, data for food relevant human virus types are missing due to the lack of methods for determining their infectivity. Parasites can be inactivated by comparatively lower pressure than vegetative bacterial cells. The degrees to which chemical reactions progress under pressure treatments are different to those of conventional thermal processes, for example, HHP leads to lower amounts of acrylamide and furan. Additionally, the formation of new unknown or unexpected substances has not yet been observed. To date, no safety-relevant chemical changes have been described for foods treated by HHP. Based on existing sensitization to non-HHP-treated food, the allergenic potential of HHP-treated food is more likely to be equivalent to untreated food. Initial findings on changes in packaging materials under HHP have not yet been adequately supported by scientific data
Successful new product development by optimizing development process effectiveness in highly regulated sectors: the case of the Spanish medical devices sector
Rapid development and commercialization of new products is of vital importance for small and medium sized enterprises (SME) in regulated sectors. Due to strict regulations, competitive advantage can hardly be achieved through the effectiveness of product concepts only. If an SME in a highly regulated sector wants to excell in new product development (NPD) performance, the company should focus on the flexibility, speed, and productivity of its NPD function: i.e. the development process effectiveness. Our main research goals are first to explore if SMEs should focus on their their development process effectiveness rather than on their product concept effectiveness to achieve high NPD performance; and second, to explore whether a shared pattern in the organization of the NPD function can be recognized to affect NPD performance positively. The medical devices sector in Spain is used as an example of a\ud
highly regulated sector. A structured survey among 11 SMEs, of which 2 were studied also as in in-depth case studies, led to the following results. First of all, indeed the companies in the dataset which focused on the effectiveness of their development process, stood out in NPD performance. Further, the higher performing companies did have a number of commonalities in the organisation of their NPD function: 1) The majority of the higher performing firms had an NPD strategy characterized by a predominantly incremental project portfolio.\ud
2) a) Successful firms with an incremental project portfolio combined this with a functional team structure b) Successful firms with a radical project portfolio combined this with a heavyweight or autonomous team structure.\ud
3) A negative reciprocal relationship exists between formalization of the NPD processes and the climate of the NPD function, in that a formalized NPD process and an innovative climate do not seem to reinforce each other. Innovative climate combined with an informal NPD process does however contribute positively to NPD performance. This effect was stronger in combination with a radical project portfolio. The highest NPD performance was measured for companies focusing mainly on incremental innovation. It is argued that in highly regulated sectors, companies with an incremental product portfolio would benefit from employing a functional structure. Those companies who choose for a more radical project portfolio in highly regulated sectors should be aware\ud
that they are likely to excell only in the longer term by focusing on strategic flexibility. In their NPD organization, they might be well advised to combine informal innovation processes with an innovative climate
Hepatitis E Virus in Pork Liver Sausage, France
We investigated viability of hepatitis E virus (HEV) identified in contaminated pork liver sausages obtained from France. HEV replication was demonstrated in 1 of 4 samples by using a 3-dimensional cell culture system. The risk for human infection with HEV by consumption of these sausages should be considered to be high
Fecal Calprotectin Excretion in Preterm Infants during the Neonatal Period
Fecal calprotectin has been proposed as a non-invasive marker of intestinal inflammation in inflammatory bowel disease in adults and children. Fecal calprotectin levels have been reported to be much higher in both healthy full-term and preterm infants than in children and adults.To determine the time course of fecal calprotectin (f-calprotectin) excretion in preterm infants from birth until hospital discharge and to identify factors influencing f-calprotectin levels in the first weeks of life, including bacterial establishment in the gut.F-calprotectin was determined using an ELISA assay in 147 samples obtained prospectively from 47 preterm infants (gestational age, and birth-weight interquartiles 27–29 weeks, and 880–1320 g, respectively) at birth, and at 2-week intervals until hospital discharge. (p = 0.047).During the first weeks of life, the high f-calprotectin values observed in preterm infants could be linked to the gut bacterial establishment
On the Action of Methotrexate and 6-Mercaptopurine on M. avium Subspecies paratuberculosis
BACKGROUND: Clinical improvement in inflammatory bowel disease (IBD) treated with methotrexate and 6-mercaptopurine (6-MP) is associated with a decrease in pro-inflammatory cytokines. This has been presumed to indicate the mechanism of action of methotrexate and 6-MP. Although controversial, there are increasingly compelling data that Mycobacterium avium subspecies paratuberculosis (MAP) may be an etiological agent in some or all of IBD. We hypothesized that the clinical efficacy of methotrexate and 6-MP in IBD may be to simply inhibit the growth of MAP. METHODOLOGY: The effect on MAP growth kinetics by methotrexate and 6-MP were evaluated in cell culture of two strains each of MAP and M. avium using a radiometric ((14)CO(2) BACTEC®) detection system that quantifies mycobacterial growth as arbitrary “growth index units” (GI). Efficacy data are presented as “percent decrease in cumulative GI” (% −ΔcGI). PRINCIPAL FINDINGS: The positive control antibiotic (clarithromycin) has ≥85% −ΔcGI at a concentration of 0.5 µg/ml. The negative control (ampicillin) has minimal inhibition at 64 µg/ml. MAP ATCC 19698 shows ≥80% −ΔcGI for both agents by 4 µg/ml. With the other three isolates, although more effective than ampicillin, 6-MP is consistently less effective than methotrexate. CONCLUSIONS: We show that methotrexate and 6-MP inhibit MAP growth in vitro. Each of the four isolates manifests different % −ΔcGI. These data are compatible with the hypothesis that the clinical improvement in patients with IBD treated with methotrexate and 6-MP could be due to treating a MAP infection. The decrease in pro-inflammatory cytokines, thought to be the primary mechanism of action, may simply be a normal, secondary, physiological response. We conclude that henceforth, in clinical studies that evaluate the effect of anti-MAP agents in IBD, the use of methotrexate and 6-MP should be excluded from any control groups
Re-examination of siRNA specificity questions role of PICH and Tao1 in the spindle checkpoint and identifies Mad2 as a sensitive target for small RNAs
The DNA-dependent adenosine triphosphatase (ATPase) Plk1-interacting checkpoint helicase (PICH) has recently been implicated in spindle checkpoint (SAC) signaling (Baumann et al., Cell 128(1):101–114, 2007). Depletion of PICH by siRNA abolished the SAC and resulted in an apparently selective loss of Mad2 from kinetochores, suggesting a role for PICH in the regulation of the Mad1–Mad2 interaction. An apparent rescue of SAC functionality by overexpression of PICH in PICH-depleted cells initially seemed to confirm a role for PICH in the SAC. However, we have subsequently discovered that all PICH-directed siRNA oligonucleotides that abolish the SAC also reduce Mad2 mRNA and protein expression. This reduction is functionally significant, as PICH siRNA does not abolish SAC activity in a cell line that harbors a bacterial artificial chromosome driving the expression of murine Mad2. Moreover, we identified several siRNA duplexes that effectively deplete PICH but do not significantly affect SAC functionality or Mad2 abundance or localization. Finally, we discovered that the ability of overexpressed PICH to restore SAC activity in PICH-depleted cells depends on sequestration of the mitotic kinase Plk1 rather than ATPase activity of PICH, pointing to an underlying mechanism of “bypass suppression.” In support of this view, depletion or inhibition of Plk1 also rescued SAC activity in cells harboring low levels of Mad2. This observation suggests that a reduction of Plk1 activity partially compensates for reduced Mad2 levels and argues that Plk1 normally reduces the strength of SAC signaling. Collectively, our results question the role of PICH in the SAC and instead identify Mad2 as a sensitive off target for small RNA duplexes. In support of the latter conclusion, our evidence suggests that an off-target effect on Mad2 may also contribute to explain the apparent role of the Tao1 kinase in SAC signaling (Draviam et al., Nat Cell Biol 9(5):556–564, 2007)
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