Transport Properties of Clean Quantum Point Contacts

Quantum point contacts are fundamental building blocks for mesoscopic transport experiments and play an important role in recent interference- and fractional quantum Hall experiments. However, it is not clear how electron-electron interactions and the random disorder potential influence the confinement potential and give rise to phenomena like the mysterious 0.7 anomaly. Novel growth techniques of GaAs/AlGaAs heterostructures for high-mobility two-dimensional electron gases enable us to investigate quantum point contacts with a strongly suppressed disorder potential. These clean quantum point contacts indeed show transport features that are obscured by disorder in standard samples. From this transport data, we are able to extract the parameters of the confinement potential which describe its shape in longitudinal and transverse direction. Knowing the shape (and hence the slope) of the confinement potential might be crucial to predict which interaction-induced states can form in quantum point contacts

Self-Reported Wisdom and Happiness: An Empirical Investigation

Possible tensions between wisdom and happiness have been extensively debated in philosophy. Some regard wisdom as the 'supreme part of happiness', whereas other think that a more accurate and wiser view on reality might reduce happiness. Analyzing a Dutch internet survey of 7037 respondents, we discovered that wisdom and happiness were modestly positively related. Wisdom, measured with the Three-Dimensional Wisdom Scale (3D-WS), explained 9.2% of the variation in hedonic happiness. The correlation with the reflective dimension of wisdom was the strongest. In addition, wisdom was more important for happiness among adults with only an elementary education. Our results suggest that happiness and wisdom do not conflict

The thalamic reticular nucleus in schizophrenia and bipolar disorder: role of parvalbumin-expressing neuron networks and oxidative stress.

Growing evidence points to a disruption of cortico-thalamo-cortical circuits in schizophrenia (SZ) and bipolar disorder (BD). Clues for a specific involvement of the thalamic reticular nucleus (TRN) come from its unique neuronal characteristics and neural connectivity, allowing it to shape the thalamo-cortical information flow. A direct involvement of the TRN in SZ and BD has not been tested thus far. We used a combination of human postmortem and rodent studies to test the hypothesis that neurons expressing parvalbumin (PV neurons), a main TRN neuronal population, and associated Wisteria floribunda agglutinin-labeled perineuronal nets (WFA/PNNs) are altered in SZ and BD, and that these changes may occur early in the course of the disease as a consequence of oxidative stress. In both disease groups, marked decreases of PV neurons (immunoreactive for PV) and WFA/PNNs were observed in the TRN, with no effects of duration of illness or age at onset. Similarly, in transgenic mice with redox dysregulation, numbers of PV neurons and WFA/PNN+PV neurons were decreased in transgenic compared with wild-type mice; these changes were present at postnatal day (P) 20 for PV neurons and P40 for WFA/PNN+PV neurons, accompanied by alterations of their firing properties. These results show profound abnormalities of PV neurons in the TRN of subjects with SZ and BD, and offer support for the hypothesis that oxidative stress may play a key role in impacting TRN PV neurons at early stages of these disorders. We put forth that these TRN abnormalities may contribute to disruptions of sleep spindles, focused attention and emotion processing in these disorders

RISK FACTORS FOR RESIDUAL DISEASE AT RE-TUR IN T1G3 BLADDER CANCER

INTRODUCTION AND OBJECTIVES: Goals of transurethral resection of a bladder tumour (TUR) are to completely resect the lesions and to make a correct diagnosis in order to adequately stage the patient. It is well known that the presence of detrusor muscle in the specimen is a prerequisite to minimize the risk of under staging. Persistent disease after resection of bladder tumours is not uncommon and is the reason why the European Guidelines recommended a reTUR for all T1 tumours. It was recently published that when there is muscle in the specimen, re-TUR does not influence progression or cancer specific survival. We present here the patient and tumour factors that may influence the presence of residual disease at re-TUR. METHODS: In our retrospective cohort of 2451 primary T1G3 patients initially treated with BCG, pathology results for 934 patients (38.1%) who underwent re-TUR are available. 75.4% had multifocal tumours, 42.7% of tumours were more than 3 cm in diameter and 25.8% had concomitant CIS. We analyse this subgroup of patients who underwent re-TUR: there was no residual disease in 267 patients (28.6%) and residual disease in 667 patients (71.4%): Ta in 378 (40.5%) and T1 in 289 (30.9%) patients. Age, gender, tumour status (primary/recurrent), previous intravesical therapy, tumour size, tumour multi-focality, presence of concomitant CIS, and muscle in the specimen were analysed in order to evaluate risk factors of residual disease at re-TUR, both in univariate analyses and multivariate logistic regressions. RESULTS: The following were not risk factors for residual disease: age, gender, tumour status and previous intravesical chemotherapy. The following were univariate risk factors for presence of residual disease: no muscle in TUR, multiple tumours, tumours > 3 cm, and presence of concomitant CISDue to the correlation between tumor multi-focality and tumor size, the multivariate model retained either the number of tumors or the tumor diameter (but not both), p < 0.001. The presence of muscle in the specimen was no longer significant, p ¼ 0.15, while the presence of CIS only remained significant in the model with tumor size, p < 0.001. CONCLUSIONS: The most significant factors for a higher risk of residual disease at re-TUR in T1G3 patients are multifocal tumours and tumours more than 3 cm. Patients with concomitant CIS and those without muscle in the specimen also have a higher risk of residual disease