Reply Gaucher, David; Gaudric, Alain
American journal of ophthalmology,
09/2008, Volume:
146, Issue:
3
Journal Article
Peer reviewed
...these cases of severe hypotonia are usually associated with choroidal folds and optic disc edema,1 which was not the case in our patients. ...no objective element in our observations supported the ...hypothesis of hypotonia.
We tested the hypothesis that underrepresented students in active-learning classrooms experience narrower achievement gaps than underrepresented students in traditional lecturing classrooms, averaged ...across all science, technology, engineering, and mathematics (STEM) fields and courses. We conducted a comprehensive search for both published and unpublished studies that compared the performance of underrepresented students to their overrepresented classmates in active-learning and traditional-lecturing treatments. This search resulted in data on student examination scores from 15 studies (9,238 total students) and data on student failure rates from 26 studies (44,606 total students). Bayesian regression analyses showed that on average, active learning reduced achievement gaps in examination scores by 33% and narrowed gaps in passing rates by 45%. The reported proportion of time that students spend on in-class activities was important, as only classes that implemented high-intensity active learning narrowed achievement gaps. Sensitivity analyses showed that the conclusions are robust to sampling bias and other issues. To explain the extensive variation in efficacy observed among studies, we propose the heads-and-hearts hypothesis, which holds that meaningful reductions in achievement gaps only occur when course designs combine deliberate practice with inclusive teaching. Our results support calls to replace traditional lecturing with evidence-based, active-learning course designs across the STEM disciplines and suggest that innovations in instructional strategies can increase equity in higher education.
Introduction Negative symptoms represent a fundamental aspect of schizophrenia: they have a substantial impact on patients’ real-life functioning and do not respond satisfactorily to currently ...available treatments. Therefore, a better understanding of the pathophysiological mechanisms underlying these symptoms could favor the development of new treatments. To date, the most validated pathophysiological hypothesis indicates an association between the Motivational domain (consisting of avolition, anhedonia and asociality) and alterations in the neuronal circuits involved in motivation. The Expressive Deficit domain (consisting of blunted affect and alogia) would be subtended by widespread alterations of cortical connectivity and associated with impaired neurocognition, social cognition, and the presence of neurological soft signs. Objectives The aim of the present study is to examine the neurobiological correlates of the two domains of negative symptoms, starting from the brain areas that have been most commonly found in the literature to be associated with negative symptoms. Methods Resting-state (rs) fMRI data were acquired in 62 subjects with schizophrenia (SZ) and 46 healthy controls (HC). The two negative symptom domains were assessed using the Brief Negative Symptom Scale. In addition, the following assessment tools were used: the Positive and Negative Syndrome Scale for the assessment of positive symptoms and disorganization, the Calgary Depression Scale for Schizophrenia for depression and the St. Hans Rating Scale for extrapyramidal symptoms. The study of the possible relationships between rs-brain activity and the negative symptoms domains was conducted through partial correlations, checking for possible confounding factors (positive, depressive, extrapyramidal symptoms and disorganization). Results The SZ, compared to the HC, showed higher rs-brain activity of the right inferior parietal lobule and of the right temporoparietal junction and lower rs-brain activity of the right dorsolateral prefrontal cortex, bilateral anterior dorsal cingulate cortex, bilateral ventral caudate and bilateral dorsal caudate. Furthermore, in the group of patients, the rs-brain activity of the left ventral caudate showed a moderate negative correlation with the Expressive deficit domain (r = -0.401; p = 0.003), but not with the Motivational domain. Conclusions The results of the present study, in line with the literature, demonstrated how the two domains of negative symptomatology are subtended by different pathophysiological mechanisms. Given the role played by the ventral caudate in neurocognitive processes, these results are in line with the hypothesis that Expressive deficit may have a common etiopathogenesis with cognitive deficits. A better understanding of the neurobiology of negative symptoms could foster the development of innovative treatment strategies targeting the two negative symptom domains. Disclosure of Interest None Declared
We consider the problem of testing multiple quantum hypotheses $\left\{ {\rho _1^{ \otimes n},...,\rho _r^{ \otimes n}} \right\}$, where an arbitrary prior distribution is given and each of the r ...hypotheses is n copies of a quantum state. It is known that the minimal average error probability Pe decays exponentially to zero, that is, Pe = exp{–ξn + 0(n)}. However, this error exponent ξ is generally unknown, except for the case that r = 2. In this paper, we solve the long-standing open problem of identifying the above error exponent, by proving Nussbaum and Szkola's conjecture that ξ = mini≠j C(ρi, ρj). The right-hand side of this equality is called the multiple quantum Chernoff distance, and $C\left( {{\rho _i},{\rho _j}} \right): = \max {}_{0 \leqslant s \leqslant 1}\left\{ { - \log Tr\rho _i^s\rho _j^{1 - s}} \right\}$ has been previously identified as the optimal error exponent for testing two hypotheses, $\rho _i^{ \otimes n}$ versus $\rho _j^{ \otimes n}$. The main ingredient of our proof is a new upper bound for the average error probability, for testing an ensemble of finite-dimensional, but otherwise general, quantum states. This upper bound, up to a states-dependent factor, matches the multiple-state generalization of Nussbaum and Szkola's lower bound. Specialized to the case r = 2, we give an alternative proof to the achievability of the binary-hypothesis Chernoff distance, which was originally proved by Audenaert et al.
Abstract
Introduction:
Cataplexy, a symptom of narcolepsy, is defined as the abrupt and uncontrollable onset of skeletal muscle paralysis during wakefulness. It has been hypothesized that cataplexy ...results from inappropriate intrusion of REM sleep paralysis into wakefulness. The mechanism of muscle paralysis in cataplexy is unclear, but is thought to result from pathological recruitment of the subcoeruleus nucleus (SubC) that generates REM sleep paralysis. Here, we show that activation of SubC neurons promotes cataplexy in narcoleptic mice, whereas, its inhibition reduces it.
Methods:
We bilaterally infused 400nL of an AAV harboring a modified G-protein coupled receptor (AAV-HSYN-hm3D(Gq)-mCherry or AAV-HSYN-hm4D(Gi)-mCherry) or an inert fluorophore (AAV-HSYN-GFP) into the SubC region of narcoleptic mice. Animals were instrumented for EEG and EMG recordings. Administration of clozapine-N-oxide (CNO, 0.5mg/kg and/or 5mg/kg) was used to activate/inhibit SubC neurons expressing modified receptors. Sleep/wake data was analyzed for 3 hours following CNO administration.
Results:
SubC activation in narcoleptic mice triggered a dose dependent increase in the number of cataplexy episodes (0.5mg/kg CNO: hm3D(Gq) x=25 ± 4.1, n=9 vs. control x=2 ± 0.6, n=3, p<0.05; 5mg/kg CNO: hm3D(Gq) x=64 ± 12.4, n=9 vs. control x= 3.3 ± 0.9, n=3, p<0.05) and in overall time spent in cataplexy (0.5mg/kg CNO: hm3D(Gq) x=14.6 ± 2.9% vs. control x= 0.6 ± 0.14%, p<0.05; 5mg/kg CNO: hm3D(Gq) x=33.3 ± 6.9% vs. control x= 0.9 ± 0.34%, p<0.05). Consistent with our hypothesis, inhibition of SubC neurons resulted in a 58% reduction in cataplexy (n=4, p<0.05).
Conclusion:
These results support our long-standing hypothesis that a REM sleep mechanism modulates muscle paralysis during cataplexy.
Support (If Any):
This research was funded by the Canadian Institutes of Health Research (CIHR), the Natural Sciences and Engineering Research Council of Canada (NSERC), and the Ontario Graduate Scholarship (OGS).
Turizmin ekonomide gösterdiǧi olumlu etkiler giderek artmaktadır. Turizm sektöründe önemli bir konumda olan Türkiye, bu sektörden elde ettiǧi gelirleri giderek artırmayı amaçlamaktadır. Bu amaçla ...çalışmada, Türkiye'nin uluslararası turizm piyasasında dünyanın farklı kıtalarında yer alan ülkeler için yakınsama hipotezinin geçerliliǧi sınanmıştır. 2000-2020 yıllarını kapsayan çalışmada TUİK tarafından oluşturulan 8 grup (Afrika, Amerika, Asya, Avrupa, Baǧımsız Devletler, OECD, Okyanusya ve Milliyetsiz) üzerinden analiz gerçekleştirilmiştir. Yakınsama hipotezinin geçerliliǧini test etmek için Furuoka (2017) tarafından geliştirilen birim kök testi kullanılmıştır. Bu çalışmanın sonucunda önerilen dört alternatif arasından D modeli en uygun yöntem olarak bulunmuştur. Buna göre yakınsamanın Asya, Avrupa ve Okyanusya için geçerli olmadıǧı görülmüştür. Yakınsamanın Amerika, OECD, Ulusal Olmayan, Baǧımsız Devletler ve Afrika için de geçerli olduǧu sonucuna varılmıştır.
Abstract
Introduction
Oxytocin is a versatile hypothalamic neuropeptide involved in diverse neurobehavioural processes. Since oxytocin can elicit anxiolytic and serenic effects, one could hypothesise ...that oxytocin should prime the brain for sleep and promote hypnogenesis. However, based on the social salience hypothesis—that oxytocin promotes prosocial behaviour and directs attention toward social stimuli—one could also posit that oxytocin should promote wakefulness. At present, little research has comprehensively characterised the effect of oxytocin on sleep-wake behaviour and no explanation to reconcile these two seemingly competing hypotheses has been proposed.
Methods
This study investigated the effects of oxytocin on sleep-wake outcomes using radiotelemetry-based polysomnography in adult male and female Wistar rats. Oxytocin was administered via the intraperitoneal (IP; 0.1, 0.3 and 1 mg/kg) and intranasal (IN; 0.06, 1, 3 mg/kg) routes. Caffeine (IP and IN; 10 mg/kg) was also administered as a wake-promoting positive control. Additionally, pre-treatment with the oxytocin receptor (OTR) antagonist L-368,899 (IP; 5 mg/kg) and vasopressin 1a receptor (V1aR) antagonist SR49059 (IP; 1 mg/kg) followed by oxytocin (IP; 1 mg/kg) was conducted to determine which receptor(s) mediated sleep-wake effects of oxytocin.
Results
In both male and female rats, IP oxytocin produced dose-dependent effects on sleep-wake behaviour. Specifically, oxytocin initially promoted quiescent wakefulness (a restful but conscious state) at the cost of reducing both active wakefulness and sleep. Throughout the 1.5-hour period post-administration, oxytocin delayed REM sleep onset and reduced the proportion of both NREM and REM sleep. Conversely, IN oxytocin did not significantly alter any sleep-wake parameters at any dose tested. Caffeine demonstrated wake-promoting effects under both the IP and IN routes of administration. The involvement of OTR and V1aR binding in oxytocin-induced effects on sleep-wake outcomes will be discussed.
Conclusion
These findings appear to reconcile the two competing hypotheses: in rats, IP oxytocin appears to promote a state of quiescent wakefulness—one of calm and rest, but also of conscious responsivity to environmental stimuli. IN oxytocin demonstrated little to no effect on sleep-wake behaviour, which is a crucial finding given the escalating use of IN oxytocin as a therapeutic for conditions with comorbid disordered sleep.
Support (if any)
None.
Abstract
Introduction
Pressure between a CPAP mask and the skin is a significant contributor to irritation and pressure ulcers, an area of localized soft tissue ischemic necrosis caused by prolonged ...pressure over bony prominences that exceeds supra capillary pressure (70 mmHg). We hypothesized that cloth masks (CM) would exert a lower nasal bridge pressure than traditional mask (TM) products constructed of silicone and plastic.
Methods
We evaluated the pressure exerted by seven types of nasal masks in three trials onto the nasal bridge of two healthy adult volunteers, one female, one male, while they received 10 cm H₂O of CPAP. Five commercially available CMs (SleepWeaver® 3D, SleepWeaver® Advance Pediatric, SleepWeaver® Élan, and SleepWeaver® Prevent, Circadiance®, LLC) were tested as were three TMs constructed primarily of silicone and plastic (DreamWisp™, Philips Respironics, Inc.; Mirage™, ResMed; Zest™, Fisher & Paykel Healthcare). Pressure was detected using a texsens®-g low pressure sensor force measuring device. Pressure data from each 30 second trial were summarized as the median value after confirming that pressure did not vary by time (one-way ANOVA, p = 0.7393). Median values were then compared across trials, subjects, and masks using one-way ANOVAs and student’s t-tests.
Results
After confirming that pressure did not vary by trial (one-way ANOVA, p=0.4585) or subject (t-test, p=0.0938), pressure data were summarized by mask. On average, CMs exerted 37.0 (17.7) mmHg of nasal bridge pressure, although there was significant variation across masks (one-way ANOVA, p < 0.0001). Conversely, TMs averaged 112 (38.5) mmHg of nasal bridge pressure without significant variation across masks (one-way ANOVA, p=0.1291). CMs averaged 75.26 mmHg less pressure than TMs (p < 0.0001), a difference of 67 percent.
Conclusion
The data supports the hypothesis that pressure from CMs on the bridge of the nose are significantly lower than a sample of TMs with similar shape and style, and the null hypothesis was rejected. Furthermore, the average CM was below the threshold for capillary closing, in contrast to the average TM. Therefore, for CPAP users with predicted or existing skin sensitivity, comfort and/or compliance concerns, CM should be considered as a first choice in mask selection.
Support (if any):
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