The Kelvin-Helmholtz instability with arbitrarily oriented body force

Interfacial stability of two parallel superposed inviscid streams of fluid applied to stability of molten liquid-gas interface on ablating reentry bod

Detecting the Starting Frame of Actions in Video

In this work, we address the problem of precisely localizing key frames of an action, for example, the precise time that a pitcher releases a baseball, or the precise time that a crowd begins to applaud. Key frame localization is a largely overlooked and important action-recognition problem, for example in the field of neuroscience, in which we would like to understand the neural activity that produces the start of a bout of an action. To address this problem, we introduce a novel structured loss function that properly weights the types of errors that matter in such applications: it more heavily penalizes extra and missed action start detections over small misalignments. Our structured loss is based on the best matching between predicted and labeled action starts. We train recurrent neural networks (RNNs) to minimize differentiable approximations of this loss. To evaluate these methods, we introduce the Mouse Reach Dataset, a large, annotated video dataset of mice performing a sequence of actions. The dataset was collected and labeled by experts for the purpose of neuroscience research. On this dataset, we demonstrate that our method outperforms related approaches and baseline methods using an unstructured loss

A systematic review of bilingual experiences, labels, and descriptions in autism spectrum disorder research

There is growing research on autism spectrum disorder (ASD) that examines linguistically diverse samples, increasing research generalizability as many individuals with ASD live in bilingual or multilingual communities. However, bilingualism is not a homogenous experience that can be easily categorized. By clarifying participants' language experiences, research findings can be more meaningful for clinicians and practitioners. In this systematic review, we document how the language experiences of samples with and without ASD were described in 103 peer-reviewed journal articles. We observed that language experiences were characterized using a wide range of labels and descriptions. Approximately half of the studies in this review reported participants' language acquisition history, and 64% of the studies defined language proficiency using standardized measures or parental reports. However, <20% of the studies reported daily language exposure and/or usage of the participants. The diversity in how participants' language experiences were characterized in research reflects the complexity of bilingualism. Yet, to further understand how ASD and bilingualism intersect across studies, to facilitate meta-science development, and to balance generalizability with specificity, reporting common characteristics of bilingual experiences is recommended

Prevention of bone mineral changes induced by bed rest: Modification by static compression simulating weight bearing, combined supplementation of oral calcium and phosphate, calcitonin injections, oscillating compression, the oral diophosphonatedisodium etidronate, and lower body negative pressure

The phenomenon of calcium loss during bed rest was found to be analogous to the loss of bone material which occurs in the hypogravic environment of space flight. Ways of preventing this occurrence are investigated. A group of healthy adult males underwent 24-30 weeks of continuous bed rest. Some of them were given an exercise program designed to resemble normal ambulatory activity; another subgroup was fed supplemental potassium phosphate. The results from a 12-week period of treatment were compared with those untreated bed rest periods. The potassium phosphate supplements prevented the hypercalciuria of bed rest, but fecal calcium tended to increase. The exercise program did not diminish the negative calcium balance. Neither treatment affected the heavy loss of mineral from the calcaneus. Several additional studies are developed to examine the problem further

Somatosensory microcircuits for real-world hand function

Two-photon calcium imaging is already well-established in flies, fish and rodents, and is providing truly revolutionary insight into the neural basis of animal behaviour. Our critical foundational milestone is applying two-photon microscopy to NHP subjects while performing hand function tasks, given their higher brain complexity and translation potential to the human brain.https://ir.lib.uwo.ca/brainscanprojectsummaries/1038/thumbnail.jp

Morphological and Physiological Features of a Set of Spinal Substantia Gelatinosa Neurons Defined by Green Fluorescent Protein Expression

The spinal substantia gelatinosa (SG) is known to be involved in the manipulation of nociceptive and thermal primary afferent input; however, the interrelationships of its neuronal components are poorly understood. As a step toward expanding understanding, we took a relatively unique approach by concentrating on a set of SG neurons selectively labeled by green fluorescent protein (GFP) in a transgenic mouse. These GFP-expressing SG neurons prove to have homogenous morphological and electrophysiological properties, are systematically spaced in the SG, contain GABA, receive C-fiber primary afferent input, and upregulate c-Fos protein in response to noxious stimuli. Together, the properties established for these GFP-labeled neurons are consistent with a modular SG organization in which afferent activity related to nociception or other C-fiber signaling are subject to integration/modulation by repeating, similar circuits of neurons

Molecular Logic of Spinocerebellar Tract Neuron Diversity and Connectivity

Coordinated motor behaviors depend on feedback communication between peripheral sensory systems and central circuits in the brain and spinal cord. Relay of muscle- and tendon-derived sensory information to the CNS is facilitated by functionally and anatomically diverse groups of spinocerebellar tract neurons (SCTNs), but the molecular logic by which SCTN diversity and connectivity is achieved is poorly understood. We used single-cell RNA sequencing and genetic manipulations to define the mechanisms governing the molecular profile and organization of SCTN subtypes. We found that SCTNs relaying proprioceptive sensory information from limb and axial muscles are generated through segmentally restricted actions of specific Hox genes. Loss of Hox function disrupts SCTN-subtype-specific transcriptional programs, leading to defects in the connections between proprioceptive sensory neurons, SCTNs, and the cerebellum. These results indicate that Hox-dependent genetic programs play essential roles in the assembly of neural circuits necessary for communication between the brain and spinal cord. © 2019 The Author(s)Baek et al. show that Hox-transcription-factor-dependent programs govern the specification and connectivity of spinal interneurons that relay muscle-derived sensory information to the cerebellum. These findings shed light on the development of neural circuits required for proprioception—the perception of body position. © 2019 The Author(s)1

Neuropixels 2.0: A miniaturized high-density probe for stable, long-term brain recordings

Measuring the dynamics of neural processing across time scales requires following the spiking of thousands of individual neurons over milliseconds and months. To address this need, we introduce the Neuropixels 2.0 probe together with newly designed analysis algorithms. The probe has more than 5000 sites and is miniaturized to facilitate chronic implants in small mammals and recording during unrestrained behavior. High-quality recordings over long time scales were reliably obtained in mice and rats in six laboratories. Improved site density and arrangement combined with newly created data processing methods enable automatic post hoc correction for brain movements, allowing recording from the same neurons for more than 2 months. These probes and algorithms enable stable recordings from thousands of sites during free behavior, even in small animals such as mice