Verletzliche Jugend - Jugendliche als Opfer von Schlägereien: empirische Ergebnisse des DJISurveys "Aufwachsen in Deutschland: Alltagswelten"

"Am Beispiel von Opfererfahrungen in körperlichen Auseinandersetzungen werden Risiko- und Schutzmarker im Aufwachsen Jugendlicher in den Blick genommen. Empirische Grundlage sind entsprechende Erfahrungen von 13- bis 17-Jährigen (n=2.708). Mittels bivariater Zusammenhangsanalysen und einer binären logistischen Regression werden Risikokonstellationen bzw. Gefährdungszusammenhänge untersucht. Das Risiko, vulnerablen Situationen ausgesetzt zu werden, erhöht sich bei Problemen mit Alkohol oder Drogen, Schulabsentismus, einem negativen Schulklima, einem schlechten Familienklima, geringer Religiosität, einer hohen eigenen Selbstkontrollorientierung sowie einem hohen Anteil gegengeschlechtlicher Freund/-innen." (Autorenreferat)"In this study, risk and protective factors are analyzed using the example of fight victimization among adolescents (13- to 17-year olds, n=2708). In a bivariate analysis and a binary logistic regression, risk situations and risk contexts are analyzed. Serious problems with alcohol or drugs, school absenteeism, a negative school atmosphere, a poor family climate, lower extent of religiousness, high internal locus of control and a high proportion of other-sex friends were shown to be statistically significant predictors of fight victimization." (author's abstract

Fluency-Based Memory Decisions in Alzheimer’s Disease: A Matter of Source Detection?

Objective: The primary aim of this study was to test whether differences in the ability of patients with Alzheimer Disease (AD) and healthy participants to detect alternative sources of fluency can account for differences observed in the use of fluency - i.e., the ease with which information is processed - as a cue for memory. Method: Twenty-two patients with AD and 22 matched controls were presented with three forced-choice visual recognition tests. In each test, an external source of fluency was provided by manipulating the perceptual quality of the items during the test phase. The detectability of the perceptual manipulation varied in each test (i.e., 10%, 20%, or 30% contrast reduction were given). Results: Data indicated that AD patients rely on fluency in a similar extent than older adults as long as they demonstrate intact detection of differences in the perceptual quality of the items. Specifically, it appears that patients’ ability to visually discriminate stimuli differing in terms of their perceptual quality is critical for patients to be able to implement strategies to appropriately use or correctly disqualify fluency during a recognition task. Conclusion: Overall, these findings suggest that the disruption of some basic cognitive processes could prevent AD patients to experience fluency in a similar extent than healthy controls. However, when the ability to detect differences in the perceptual quality of the stimuli was taken into account, patients appeared to be as able as controls to rely on fluency to guide their memory decisions

A dose-effect relationship for deltaretrovirus-dependent leukemogenesis in sheep

<p>Abstract</p> <p>Background</p> <p>Retrovirus-induced tumors develop in a broad range of frequencies and after extremely variable periods of time, from only a few days to several decades, depending mainly on virus type. For hitherto unexplained reasons, deltaretroviruses cause hematological malignancies only in a minority of naturally infected organisms and after a very prolonged period of clinical latency.</p> <p>Results</p> <p>Here we demonstrate that the development of malignancies in sheep experimentally infected with the deltaretrovirus bovine leukemia virus (BLV) depends only on the level of BLV replication. Animals were experimentally infected with leukemogenic or attenuated, but infectious, BLV molecular clones and monitored prospectively through 8 months for viral replication. As early as 2 weeks after infection and subsequently at any time during follow-up, leukemogenic viruses produced significantly higher absolute levels of reverse transcription (RT), clonal expansion of infected cells, and circulating proviruses with RT- and somatic-dependent mutations than attenuated viruses. These differences were only quantitative, and both kinds of viruses triggered parallel temporal fluctuations of host lymphoid cells, viral loads, infected cell clonality and proliferation.</p> <p>Conclusion</p> <p>Deltaretrovirus-associated leukemogenesis in sheep appears to be a two-hit process over time depending on the amounts of first horizontally and then vertically expanded viruses.</p

Early and transient reverse transcription during primary deltaretroviral infection of sheep

<p>Abstract</p> <p>Background</p> <p>Intraindividual genetic variability plays a central role in deltaretrovirus replication and associated leukemogenesis in animals as in humans. To date, the replication of these viruses has only been investigated during the chronic phase of the infection when they mainly spread through the clonal expansion of their host cells, vary through a somatic mutation process without evidence for reverse transcriptase (RT)-associated substitution. Primary infection of a new organism necessary involves allogenic cell infection and thus reverse transcription.</p> <p>Results</p> <p>Here we demonstrate that the primary experimental bovine leukemia virus (BLV) infection of sheep displays an early and intense burst of horizontal replicative dissemination of the virus generating frequent RT-associated substitutions that account for 69% of the in vivo BLV genetic variability during the first 8 months of the infection. During this period, evidence has been found of a cell-to-cell passage of a mutated sequence and of a sequence having undergone both RT-associated and somatic mutations. The detection of RT-dependent proviral substitution was restricted to a narrow window encompassing the first 250 days following seroconversion.</p> <p>Conclusion</p> <p>In contrast to lentiviruses, deltaretroviruses display two time-dependent mechanisms of genetic variation that parallel their two-step nature of replication <it>in vivo</it>. We propose that the early and transient RT-based horizontal replication helps the virus escape the first wave of host immune response whereas somatic-dependent genetic variability during persistent clonal expansion helps infected clones escape the persistent and intense immune pressure that characterizes the chronic phase of deltaretrovirus infection.</p

Anticipating water infrastructure renewal:A framing perspective on organizational learning in public agencies

Water authorities in Western countries are increasingly confronted with waterway renewal. Ageing waterway infrastructures put the reliability of the existing network under pressure. Similarly, they open up the need to anticipate long-term uncertainties to ensure network performance. Aligning organizational practices to this new context can be considered an organizational learning process, which concerns improving current practices as well as reconsidering underlying values. Against the background of public management reforms, we aim to understand the organizational learning process in a case study of the Dutch authority Rijkswaterstaat, which is facing a major waterway renewal challenge. By developing a framing perspective on organizational learning, our analysis theoretically provides more insight into agencies anticipating change and empirically into waterway renewal in practice. Our research demonstrates that waterway renewal is primarily framed from a New Public Management viewpoint in which change is approached rather pragmatically. Accordingly, we observed a refinement of existing practice that protects the agency’s mission. Higher levels of learning were discarded as potentially disruptive to waterway management, leaving more fundamental change untouched. We therefore question to what extent water authorities are capable of fully addressing waterway renewal. Nevertheless, the repositioning process resulted in opportunities for reflecting on dominant frames and introducing new concepts. To better seize such opportunities and thus improve alignment to waterway renewal, water authorities can, in addition to improving existing practices, re-interpret dominant frames and construct a new narrative in which future, long-term uncertainties are acknowledged as inherent conditions for agencies to cope with

Overview of Advanced LIGO Adaptive Optics

This is an overview of the adaptive optics used in Advanced LIGO (aLIGO), known as the thermal compensation system (TCS). The thermal compensation system was designed to minimize thermally-induced spatial distortions in the interferometer optical modes and to provide some correction for static curvature errors in the core optics of aLIGO. The TCS is comprised of ring heater actuators, spatially tunable CO$_{2}$ laser projectors and Hartmann wavefront sensors. The system meets the requirements of correcting for nominal distortion in Advanced LIGO to a maximum residual error of 5.4nm, weighted across the laser beam, for up to 125W of laser input power into the interferometer

Overview of Advanced LIGO Adaptive Optics

This is an overview of the adaptive optics used in Advanced LIGO (aLIGO), known as the thermal compensation system (TCS). The TCS was designed to minimize thermally induced spatial distortions in the interferometer optical modes and to provide some correction for static curvature errors in the core optics of aLIGO. The TCS is comprised of ring heater actuators, spatially tunable CO_2 laser projectors, and Hartmann wavefront sensors. The system meets the requirements of correcting for nominal distortion in aLIGO to a maximum residual error of 5.4 nm rms, weighted across the laser beam, for up to 125 W of laser input power into the interferometer

Theoretical orbital period distributions of cataclysmic variables above the period gap: effects of circumbinary disks

The population of non magnetic cataclysmic variables evolving under the influence of a circumbinary disk is investigated for systems above the upper edge of the period gap at orbital periods greater than 2.75hr. For a fractional mass input rate into the disk, corresponding to 3e-4 of the mass transfer rate, the model systems exhibit a bounce at orbital periods greater than 2.75hr. The simulations reveal that (1) some systems can exist as dwarf nova type systems throughout their lifetime, (2) dwarf nova type systems can evolve into nova-like systems as their mass transfer rate increases with increasing circumbinary disk mass, and (3) nova-like systems can evolve back into dwarf nova systems during their postbounce evolution to longer orbital periods. Among these subclasses, nova-like cataclysmic variables would be the best candidates to search for circumbinary disks at wavelengths greater than 10 micron. The theoretical orbital period distribution of our population synthesis model is in reasonable accord with the combined population of dwarf novae and nova-like systems above the period gap, suggesting the possibility that systems with unevolved donors need not detach and evolve below the period gap as in the disrupted magnetic braking model. The resulting population furthermore reveals the possible presence of systems with small mass ratios (a property of systems exhibiting superhump phenomena at long orbital periods) and a preference of O/Ne/Mg white dwarfs in dwarf nova systems in comparison to nova-like systems. The importance of observational bias in accounting for the differing populations is examined, and it is shown that an understanding of these effects is necessary in order to confront the theoretical distributions with the observed ones in a meaningful manner. (abridged)Comment: accepted for publication in Ap