A pedagogic appraisal of the Priority Heuristic

We have explored how science and mathematics teachers made decisions when confronted with a dilemma in which a fictitious young woman, Deborah, may choose to have an operation that might address a painful spinal condition. We sought to explore the extent to which psychological heuristic models, in particular the Priority Heuristic, might successfully describe the decision-making process of these teachers and how an analysis of the role of personal and emotional factors in shaping the decision-making process might inform pedagogical design. A novel aspect of this study is that the setting in which the decision-making process is examined contrasts sharply with those used in psychological experiments. We found that to some extent, even in this contrasting setting, the Priority Heuristic could describe these teachers' decision-making. Further analysis of the transcripts yielded some insights into limitations on scope as well the richness and complexity in how personal factors were brought to bear. We see these limitations as design opportunities for educational intervention

Ultrathin compound semiconductor on insulator layers for high performance nanoscale transistors

Over the past several years, the inherent scaling limitations of electron devices have fueled the exploration of high carrier mobility semiconductors as a Si replacement to further enhance the device performance. In particular, compound semiconductors heterogeneously integrated on Si substrates have been actively studied, combining the high mobility of III-V semiconductors and the well-established, low cost processing of Si technology. This integration, however, presents significant challenges. Conventionally, heteroepitaxial growth of complex multilayers on Si has been explored. Besides complexity, high defect densities and junction leakage currents present limitations in the approach. Motivated by this challenge, here we utilize an epitaxial transfer method for the integration of ultrathin layers of single-crystalline InAs on Si/SiO2 substrates. As a parallel to silicon-on-insulator (SOI) technology14,we use the abbreviation "XOI" to represent our compound semiconductor-on-insulator platform. Through experiments and simulation, the electrical properties of InAs XOI transistors are explored, elucidating the critical role of quantum confinement in the transport properties of ultrathin XOI layers. Importantly, a high quality InAs/dielectric interface is obtained by the use of a novel thermally grown interfacial InAsOx layer (~1 nm thick). The fabricated FETs exhibit an impressive peak transconductance of ~1.6 mS/{\mu}m at VDS=0.5V with ON/OFF current ratio of greater than 10,000 and a subthreshold swing of 107-150 mV/decade for a channel length of ~0.5 {\mu}m

Cooperation beyond consanguinity: post-marital residence, delineations of kin, and social support among South Indian Tamils

Evolutionary ecologists have shown that relatives are important providers of support across many species. Among humans, cultural reckonings of kinship are more than just relatedness, as they interact with systems of descent, inheritance, marriage and residence. These cultural aspects of kinship may be particularly important when a person is determining which kin, if any, to call upon for help. Here, we explore the relationship between kinship and cooperation by drawing upon social support network data from two villages in South India. While these Tamil villages have a nominally male-biased kinship system (being patrilocal and patrilineal), matrilateral kin play essential social roles and many women reside in their natal villages, letting us tease apart the relative importance of genetic relatedness, kinship and residence in accessing social support. We find that people often name both their consanguineal and affinal kin as providing them with support, and we see some weakening of support with lesser relatedness. Matrilateral and patrilateral relatives are roughly equally likely to be named, and the greatest distinction instead is in their availability, which is highly contingent on post-marital residence patterns. People residing in their natal village have many more consanguineal relatives present than those who have relocated. Still, relocation has only a small effect on an individual's network size, as non-natal residents are more reliant on the few kin that they have present, most of whom are affines. In sum, marriage patterns have an important impact on kin availability, but the flexibility offered by the broadening of the concept of kin helps people develop the cooperative relationships that they rely upon, even in the absence of genetic relatives. This article is part of the theme issue 'The evolution of female-biased kinship in humans and other mammals'

The initial U.S. experience with the Tempo active fixation temporary pacing lead in structural heart interventions

ObjectivesThis multicenter retrospective study of the initial U.S. experience evaluated the safety and efficacy of temporary cardiac pacing with the Tempo® Temporary Pacing Lead.BackgroundDespite increasing use of temporary cardiac pacing with the rapid growth of structural heart procedures, temporary pacing leads have not significantly improved. The Tempo lead is a new temporary pacing lead with a soft tip intended to minimize the risk of perforation and a novel active fixation mechanism designed to enhance lead stability.MethodsData from 269 consecutive structural heart procedures were collected. Outcomes included device safety (absence of clinically significant cardiac perforation, new pericardial effusion, or sustained ventricular arrhythmia) and efficacy (clinically acceptable pacing thresholds with successful pace capture throughout the index procedure). Postprocedure practices and sustained lead performance were also analyzed.ResultsThe Tempo lead was successfully positioned in the right ventricle and achieved pacing in 264 of 269 patients (98.1%). Two patients (0.8%) experienced loss of pace capture. Procedural mean pace capture threshold (PCT) was 0.7 ± 0.8 mA. There were no clinically significant perforations, pericardial effusions, or sustained device‐related arrhythmias. The Tempo lead was left in place postprocedure in 189 patients (71.6%) for mean duration of 43.3 ± 0.7 hr (range 2.5–221.3 hr) with final PCT of 0.84 ± 1.04 mA (n = 80). Of these patients, 84.1% mobilized out of bed with no lead dislodgment.ConclusionThe Tempo lead is safe and effective for temporary cardiac pacing for structural heart procedures, provides stable peri and postprocedural pacing and allows mobilization of patients who require temporary pacing leads.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154941/1/ccd28476.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154941/2/ccd28476_am.pd

Adaptive Gain Modulation in V1 Explains Contextual Modifications during Bisection Learning

The neuronal processing of visual stimuli in primary visual cortex (V1) can be modified by perceptual training. Training in bisection discrimination, for instance, changes the contextual interactions in V1 elicited by parallel lines. Before training, two parallel lines inhibit their individual V1-responses. After bisection training, inhibition turns into non-symmetric excitation while performing the bisection task. Yet, the receptive field of the V1 neurons evaluated by a single line does not change during task performance. We present a model of recurrent processing in V1 where the neuronal gain can be modulated by a global attentional signal. Perceptual learning mainly consists in strengthening this attentional signal, leading to a more effective gain modulation. The model reproduces both the psychophysical results on bisection learning and the modified contextual interactions observed in V1 during task performance. It makes several predictions, for instance that imagery training should improve the performance, or that a slight stimulus wiggling can strongly affect the representation in V1 while performing the task. We conclude that strengthening a top-down induced gain increase can explain perceptual learning, and that this top-down signal can modify lateral interactions within V1, without significantly changing the classical receptive field of V1 neurons

Giant pyogenic granuloma of the thigh: a case report

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