369 research outputs found
Hochschulisches Lernen â eine analytische Perspektive
Dieser Beitrag betrachtet hochschulisches Lernen unter einer analytischen Perspektive: Danach artikuliert sich hochschulisches Lernen im institutionellen Kontext der Hochschule mit ihren studiengangstrukturellen Rahmenbedingungen in einer je spezifischen, dabei stets kontingenten und polymorphen Koppelung zwischen Wissenschaft als Ort der Wissensproduktion einerseits und Studium als Ort der Erschliesung von Sinn- und Handlungsressourcen andererseits. Hochschulisches Lernen lasst sich als Moglichkeitsraum von Figurationen dieser Bezugnahmen rekonstruieren. Die Analyse des Lernens an Hochschulen erschliest auserdem Forschungsperspektiven einer bildungswissenschaftlichen Hochschulforschung und einer theoretischen Hochschuldidaktik, zu denen die Erwachsenenbildungswissenschaft substanzielle Beitrage liefern kann
Dynamic generation of maximally entangled photon multiplets by adiabatic passage
The adiabatic passage scheme for quantum state synthesis, in which atomic
Zeeman coherences are mapped to photon states in an optical cavity, is extended
to the general case of two degenerate cavity modes with orthogonal
polarization. Analytical calculations of the dressed-state structure and Monte
Carlo wave-function simulations of the system dynamics show that, for a
suitably chosen cavity detuning, it is possible to generate states of photon
multiplets that are maximally entangled in polarization. These states display
nonclassical correlations of the type described by Greenberger, Horne, and
Zeilinger (GHZ). An experimental scheme to realize a GHZ measurement using
coincidence detection of the photons escaping from the cavity is proposed. The
correlations are found to originate in the dynamics of the adiabatic passage
and persist even if cavity decay and GHZ state synthesis compete on the same
time scale. Beyond entangled field states, it is also possible to generate
entanglement between photons and the atom by using a different atomic
transition and initial Zeeman state.Comment: 22 pages (RevTeX), including 23 postscript figures. To be published
in Physical Review
ATRT-02. Neuropsychological function in infant atypical teratoid/rhabdoid tumor versus low-grade glioma survivors reflects tumor malignancy and multimodal treatment [Abstract]
BACKGROUND: Therapy of infants with brain tumors predisposes these patients to increased risks for cognitive sequelae, especially following radiotherapy. Neuropsychological outcome gains importance for those 40-60% of patients with an atypical teratoid/rhabdoid tumor (ATRT) who survive beyond 2 years. Still, reports on cognitive late-effects in children with ATRT are scarce compared to other pediatric brain tumor groups. We analyzed neuropsychological outcome for long-term ATRT-survivors registered in EU-RHAB and infant low-grade glioma (LGG) survivors from the SIOP-LGG 2004-study and LGG-registry. PATIENTS+METHODS: Age at diagnosis of both cohorts was 0-36 months. ATRT-patients (n=13) treated with up to 54Gy radiotherapy (median age 22 months (Âą7.1)) were evaluated with the âATRT-Neuropsychologyâ tool based on SIOPE-BTG QoS-Group recommendations at median 6.8 years (Âą2.8) after diagnosis. LGG-patients (n=15) treated without radiotherapy (4/15 with chemotherapy) were analyzed with the German âNeuropsychological-Basic-Diagnosticâ tool 5.2 years (Âą0.6) post-diagnosis. RESULTS: The ATRT- vs. LGG-cohorts were comparable for median age at diagnosis, sex-ratio and tumor-localization, though they differed slightly in median age at assessment (9.5/7.2 years (Âą2.5/1.1)). Results of age-appropriate tests showed increased impairments for ATRT-patients in fluid intelligence (FI) (p=.006, d=1.214) and in visual-spatial processing (VSP) (p<.001, d=2.233) compared to LGG-patients. The median for neuropsychological test results of ATRT-patients spanned from considerably below the normal to the lower normal range (median=65-90), while results of LGG-patients were mostly in the lower normal range (median=83-103). Results for psychomotor speed abilities (PMS) were distinctly below the norm for both patient groups (p=.002-.007). CONCLUSION: Infant ATRT- and LGG-patients develop significant impairments in PMS abilities following multimodal treatment. Long-term survivors of ATRT suffer from additional FI and VSP deficits. Our data suggest that high malignancy requiring multimodal treatment determines the inferior cognitive outcome for the ATRT-cohort. Long-term neuropsychological monitoring (and treatment options) should be implemented as standard of care in ATRT- and LGG-trials
QOL-31. Neuropsychological functioning and quality of life in infant AT/RT survivors: focus on fluid intelligence and visual processing [Abstract]
BACKGROUND
Understanding the long-term cognitive sequelae in infant brain tumor survivors remains incomplete, particularly regarding the impact of tumor type, multimodal treatment, and other patient-related factors. This retrospective analysis explores neuropsychological and quality of survival (QoS) outcomes in survivors of atypical teratoid/rhabdoid tumors (AT/RT) and extracranial malignant rhabdoid tumors of soft tissues (eMRT) and kidneys (RTK), all treated within the same framework. Neuropsychological data from children with AT/RT were compared to data from children with non-irradiated low-grade glioma (LGG).
METHODS
Patients (0 - 36 months at diagnosis) underwent various treatments, including radio-chemotherapy for AT/RT (n = 13) and eMRT/RTK (n = 7), chemotherapy only for LGG (n = 4) and eMRT/RTK (n = 1), or observation for LGG (n = 11). Neuropsychological evaluations were conducted at a median of 6.8 years (AT/RT), 6.6 years (eMRT/RTK), and 5.2 years (LGG) post-diagnosis.
RESULTS
Impairments were observed for all tumour types. Patients with AT/RT exhibited impairments in fluid intelligence (p =.041; d = 1.11) and visual processing (p =.001; d = 2.09) when compared to LGG-patients. Both groups demonstrated deficits in psychomotor speed and attention abilities (p <.001â.019; d = 0.79â1.90). Diagnosis significantly predicted cognitive outcomes, whereas gender and age-related variables did not. QoS outcomes for all rhabdoid patients indicated lower scores in psychosocial functioning (p =.023; d = 0.78) and quality of life (p =.006; d = 0.79) compared to healthy controls.
CONCLUSIONS
Infant rhabdoid tumor survivors experience cognitive and quality-of-life sequelae. Patients with AT/RT are especially vulnerable to impairments in fluid intelligence and visual processing, while infant LGG-patients without radiotherapy demonstrated comparable deficits in psychomotor and attention abilities. Close monitoring of neuropsychological and quality of life outcomes is crucial for early onset and multimodal treatment
Survivors of infant atypical teratoid/rhabdoid tumors present with severely impaired cognitive functions especially for fluid intelligence and visual processing: data from the German brain tumor studies
Background
The contribution of tumor type, multimodal treatment, and other patient-related factors upon long-term cognitive sequelae in infant brain tumor survivors remains undefined. We add our retrospective analysis of neuropsychological and quality of survival (QoS) outcome data of survivors of atypical teratoid/rhabdoid tumors (ATRT) and extracranial malignant rhabdoid tumors of the soft tissues (eMRT) and kidneys (RTK) treated within the same framework. Neuropsychological data from children with ATRT were compared to data from children with non-irradiated low-grade glioma (LGG).
Patients and methods
Following surgery, patients (0â36 months at diagnosis) had received radio-chemotherapy (up to 54 Gy; ATRT: n = 13; eMRT/RTK: n = 7), chemotherapy only (LGG: n = 4; eMRT/RTK: n = 1) or had been observed (LGG: n = 11). Neuropsychological evaluation employing comparable tests was performed at median 6.8 years (ATRT), 6.6 years (eMRT/RTK), and 5.2 years (LGG) post diagnosis.
Results
We detected sequelae in various domains for all tumor types. Group comparison showed impairments, specifically in fluid intelligence (p = .041; d = 1.11) and visual processing (p = .001; d = 2.09) in ATRT patients when compared to LGG patients. Results for psychomotor speed and attention abilities were significantly below the norm for both groups (p < .001â.019; d = 0.79â1.90). Diagnosis predicted impairments of cognitive outcome, while sex- and age-related variables did not. QoS outcome for all rhabdoid patients displayed impairments mainly in social (p = .008; d = 0.74) and school functioning (p = .048; d = 0.67), as well as lower overall scores in psychosocial functioning (p = .023; d = 0.78) and quality of life (p = .006; d = 0.79) compared to healthy controls.
Conclusion
Survivors of infant ATRT experience various late effects in cognition and QoS following multimodal treatment, while infant LGG patients without radiotherapy demonstrated comparable impairments in psychomotor and attention abilities. Early onset and multimodal treatment of rhabdoid tumors require close monitoring of neuropsychological and QoS sequelae
Invasion of ovarian cancer cells is induced by PITX2-mediated activation of TGF-β and Activin-A
Background:Most ovarian cancers are highly invasive in nature and the high burden of metastatic disease make them a leading cause of mortality among all gynaecological malignancies. The homeodomain transcription factor, PITX2 is associated with cancer in different tissues. Our previous studies demonstrated increased PITX2 expression in human ovarian tumours. Growing evidence linking activation of TGF-β pathway by homeodomain proteins prompted us to look for the possible involvement of this signalling pathway in PITX2-mediated progression of ovarian cancer.
Methods: The status of TGF-β signalling in human ovarian tissues was assessed by immunohistochemistry. The
expression level of TGFB/INHBA and other invasion-associated genes was measured by quantitative-PCR (Q-PCR)
and Western Blot after transfection/treatments with clones/reagents in normal/cancer cells. The physiological
effect of PITX2 on invasion/motility was checked by matrigel invasion and wound healing assay. The PITX2- and
activin-induced epithelial-mesenchymal transition (EMT) was evaluated by Q-PCR of respective markers and confocal/phase-contrast imaging of cells.
Results: Human ovarian tumours showed enhanced TGF-β signalling. Our study uncovers the PITX2-induced
expression of TGFB1/2/3 as well as INHBA genes (p < 0.01) followed by SMAD2/3-dependent TGF-β signalling
pathway. PITX2-induced TGF-β pathway regulated the expression of invasion-associated genes, SNAI1, CDH1
and MMP9 (p < 0.01) that accounted for enhanced motility/invasion of ovarian cancers. Snail and MMP9 acted
as important mediators of PITX2-induced invasiveness of ovarian cancer cells. PITX2 over-expression resulted in
loss of epithelial markers (p < 0.01) and gain of mesenchymal markers (p < 0.01) that contributed significantly to ovarian oncogenesis. PITX2-induced INHBA expression (p < 0.01) contributed to EMT in both normal and ovarian cancer cells.
Conclusions: Overall, our findings suggest a significant contributory role of PITX2 in promoting invasive
behaviour of ovarian cancer cells through up-regulation of TGFB/INHBA. We have also identified the previously unknown involvement of activin-A in promoting EMT. Our work provides novel mechanistic insights into the invasive behavior of ovarian cancer cells. The extension of this study have the potential for therapeutic applications in future
The incidence of experimental smoking in school children: an 8-year follow-up of the child and adolescent behaviors in long-term evolution (CABLE) study
<p>Abstract</p> <p>Background</p> <p>Studies have established that most regular adult smokers become addicted in their adolescent years. We investigated the incidence of and risk factors associated with initial experimental smoking among a group of school children who were followed for 8 years.</p> <p>Methods</p> <p>We used cohort data collected as part of the Child and Adolescent Behaviors in Long-term Evolution (CABLE) study, which selected nine elementary schools each from an urban area (Taipei City) and a rural area (Hsingchu county) in northern Taiwan. From 2002 to 2008, children were asked annually whether they had smoked in the previous year. An accelerated lifetime model with Weibull distribution was used to examine the factors associated with experimental smoking.</p> <p>Results</p> <p>In 2001, 2686 4<sup>th</sup>-graders participated in the study. For each year from 2002 to 2008, their incidences of trial smoking were 3.1%, 4.0%, 2.8%, 6.0%, 5.3%, 5.0% and 6.0%, respectively. There was an increase from 7<sup>th </sup>to 8<sup>th </sup>grade (6.0%). Children who were males, lived in rural areas, came from single-parent families, had parents who smoked, and had peers who smoked were more likely to try smoking earlier. The influence of parents and peers on experimental smoking demonstrated gradient effects.</p> <p>Conclusions</p> <p>This study used a cohort to examine incidence and multiple influences, including individual factors, familial factors, and community factors, on experimental smoking in adolescents. The findings fit the social ecological model, highlighting the influences of family and friends. School and community attachment were associated with experimental smoking in teenagers.</p
Enhancement of Both Long-Term Depression Induction and Optokinetic Response Adaptation in Mice Lacking Delphilin
In the cerebellum, Delphilin is expressed selectively in Purkinje cells (PCs) and is localized exclusively at parallel fiber (PF) synapses, where it interacts with glutamate receptor (GluR) δ2 that is essential for long-term depression (LTD), motor learning and cerebellar wiring. Delphilin ablation exerted little effect on the synaptic localization of GluRδ2. There were no detectable abnormalities in cerebellar histology, PC cytology and PC synapse formation in contrast to GluRδ2 mutant mice. However, LTD induction was facilitated at PF-PC synapses in Delphilin mutant mice. Intracellular Ca2+ required for the induction of LTD appeared to be reduced in the mutant mice, while Ca2+ influx through voltage-gated Ca2+ channels and metabotropic GluR1-mediated slow synaptic response were similar between wild-type and mutant mice. We further showed that the gain-increase adaptation of the optokinetic response (OKR) was enhanced in the mutant mice. These findings are compatible with the idea that LTD induction at PF-PC synapses is a crucial rate-limiting step in OKR gain-increase adaptation, a simple form of motor learning. As exemplified in this study, enhancing synaptic plasticity at a specific synaptic site of a neural network is a useful approach to understanding the roles of multiple plasticity mechanisms at various cerebellar synapses in motor control and learning
The Optokinetic Reflex as a Tool for Quantitative Analyses of Nervous System Function in Mice: Application to Genetic and Drug-Induced Variation
The optokinetic reflex (OKR), which serves to stabilize a moving image on the retina, is a behavioral response that has many favorable attributes as a test of CNS function. The OKR requires no training, assesses the function of diverse CNS circuits, can be induced repeatedly with minimal fatigue or adaptation, and produces an electronic record that is readily and objectively quantifiable
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