Radio Galaxy Zoo: CLARAN - A deep learning classifier for radio morphologies

The upcoming next-generation large area radio continuum surveys can expect tens of millions of radio sources, rendering the traditional method for radio morphology classification through visual inspection unfeasible.We present CLARAN-Classifying Radio sources Automatically with Neural networks - a proof-of-concept radio source morphology classifier based upon the Faster Region-based Convolutional Neutral Networks method. Specifically, we train and test CLARAN on the FIRST and WISE (Wide-field Infrared Survey Explorer) images from the Radio Galaxy Zoo Data Release 1 catalogue. CLARAN provides end users with automated identification of radio source morphology classifications from a simple input of a radio image and a counterpart infrared image of the same region. CLARAN is the first open-source, endto- end radio source morphology classifier that is capable of locating and associating discrete and extended components of radio sources in a fast (<200 ms per image) and accurate (=90 per cent) fashion. Future work will improve CLARAN's relatively lower success rates in dealing with multisource fields and will enable CLARAN to identify sources on much larger fields without loss in classification accuracy

Changes in Behavior and Ultrasonic Vocalizations During Pair Bonding and in Response to an Infidelity Challenge in Monogamous California Mice

Despite recent exciting research about pair bonding, little is known about how mammalian vocalizations change with the initiation and maintenance of pair bonding in monogamous species. Moreover, even less is known about the significance of pair bond resilience in the face of social challenges. In the strictly monogamous California mouse (Peromyscus californicus), we measured changes in ultrasonic vocalizations (USV) and other behaviors within male-female dyads over the course of pair bonding and characterized associations of USVs with affiliation and aggression. After 1 week of cohabitation, pairs exhibited decreased aggression and “bark” USVs, and increased “simple sweep” and “sustained vocalization” (SV) USV types. Accordingly, the number of barks was associated with aggression, whereas the number of simple sweeps and the number, call duration and bout size of SVs corresponded with affiliation. We then experimentally assessed the impact of an infidelity challenge (1 week cohabitation with an unfamiliar, opposite-sex, extra-pair individual) for both sexes on pair social behavior, acoustic behavior, and reproductive success. The infidelity challenge temporarily disrupted pair bond interactions during pair reunion, independent of which sex experienced the infidelity challenge, via both increases in aggression and barks, and a stunting of affiliation and SVs, compared to control pairs. Pair reproductive success, in the form of birth latency, litter size, pup survival and birth weight, did not differ between infidelity challenge pairs and controls. The quality of pair interactions, however, was associated with reproductive success: aggression during pair reunion across all pairs was associated with a lower likelihood of successfully producing a litter. Similarly, among infidelity challenge pairs, but not the controls, there was a positive association between pair affiliation and paternal care, and a negative association between pair aggression and paternal care. Overall, the infidelity challenge revealed a weak negative effect on reproductive success, but we speculate, based on our results, that greater resiliency of a pair bond can moderate negative effects of a social challenge

Metabolic Levels in the Corpus Callosum and Their Structural and Behavioral Correlates after Moderate to Severe Pediatric TBI

Diffuse axonal injury (DAI) secondary to traumatic brain injury (TBI) contributes to long-term functional morbidity. The corpus callosum (CC) is particularly vulnerable to this type of injury. Magnetic resonance spectroscopy (MRS) was used to characterize the metabolic status of two CC regions of interest (ROIs) (anterior and posterior), and their structural (diffusion tensor imaging; DTI) and neurobehavioral (neurocognitive functioning, bimanual coordination, and interhemispheric transfer time [IHTT]) correlates. Two groups of moderate/severe TBI patients (ages 12–18 years) were studied: post-acute (5 months post-injury; n = 10), and chronic (14.7 months post-injury; n = 8), in addition to 10 age-matched healthy controls. Creatine (energy metabolism) did not differ between groups across both ROIs and time points. In the TBI group, choline (membrane degeneration/inflammation) was elevated for both ROIs at the post-acute but not chronic period. N-acetyl aspartate (NAA) (neuronal/axonal integrity) was reduced initially for both ROIs, with partial normalization at the chronic time point. Posterior, not anterior, NAA was positively correlated with DTI fractional anisotropy (FA) (r = 0.88), and most domains of neurocognition (r range 0.22–0.65), and negatively correlated with IHTT (r = −0.89). Inverse corerlations were noted between creatine and posterior FA (r = −0.76), neurocognition (r range −0.22 to −0.71), and IHTT (r = 0.76). Multimodal studies at distinct time points in specific brain structures are necessary to delineate the course of the degenerative and reparative processes following TBI, which allows for preliminary hypotheses about the nature and course of the neural mechanisms of subsequent functional morbidity. This will help guide the future development of targeted therapeutic agents

Clinical proton MR spectroscopy in central nervous system disorders

<b>This article is free to read on the publishers website</b>\ud \ud A large body of published work shows that proton (hydrogen 1 [¹H]) magnetic resonance (MR) spectroscopy has evolved from a research tool into a clinical neuroimaging modality. Herein, the authors present a summary of brain disorders in which MR spectroscopy has an impact on patient management, together with a critical consideration of common data acquisition and processing procedures. The article documents the impact of ¹H MR spectroscopy in the clinical evaluation of disorders of the central nervous system. The clinical usefulness of ¹H MR spectroscopy has been established for brain neoplasms, neonatal and pediatric disorders (hypoxia-ischemia, inherited metabolic diseases, and traumatic brain injury), demyelinating disorders, and infectious brain lesions. The growing list of disorders for which ¹H MR spectroscopy may contribute to patient management extends to neurodegenerative diseases, epilepsy, and stroke. To facilitate expanded clinical acceptance and standardization of MR spectroscopy methodology, guidelines are provided for data acquisition and analysis, quality assessment, and interpretation. Finally, the authors offer recommendations to expedite the use of robust MR spectroscopy methodology in the clinical setting, including incorporation of technical advances on clinical units

Clinical proton MR spectroscopy in central nervous system disorders.

A large body of published work shows that proton (hydrogen 1 [(1)H]) magnetic resonance (MR) spectroscopy has evolved from a research tool into a clinical neuroimaging modality. Herein, the authors present a summary of brain disorders in which MR spectroscopy has an impact on patient management, together with a critical consideration of common data acquisition and processing procedures. The article documents the impact of (1)H MR spectroscopy in the clinical evaluation of disorders of the central nervous system. The clinical usefulness of (1)H MR spectroscopy has been established for brain neoplasms, neonatal and pediatric disorders (hypoxia-ischemia, inherited metabolic diseases, and traumatic brain injury), demyelinating disorders, and infectious brain lesions. The growing list of disorders for which (1)H MR spectroscopy may contribute to patient management extends to neurodegenerative diseases, epilepsy, and stroke. To facilitate expanded clinical acceptance and standardization of MR spectroscopy methodology, guidelines are provided for data acquisition and analysis, quality assessment, and interpretation. Finally, the authors offer recommendations to expedite the use of robust MR spectroscopy methodology in the clinical setting, including incorporation of technical advances on clinical units

Genetic Dissection of the Role of Cannabinoid Type-1 Receptors in the Emotional Consequences of Repeated Social Stress in Mice.

International audienceThe endocannabinoid system (ECS) tightly controls emotional responses to acute aversive stimuli. Repeated stress alters ECS activity but the role played by the ECS in the emotional consequences of repeated stress has not been investigated in detail. This study used social defeat stress, together with pharmacology and genetics to examine the role of cannabinoid type-1 (CB(1)) receptors on repeated stress-induced emotional alterations. Seven daily social defeat sessions increased water (but not food) intake, sucrose preference, anxiety, cued fear expression, and adrenal weight in C57BL/6N mice. The first and the last social stress sessions triggered immediate brain region-dependent changes in the concentrations of the principal endocannabinoids anandamide and 2-arachidonoylglycerol. Pretreatment before each of the seven stress sessions with the CB(1) receptor antagonist rimonabant prolonged freezing responses of stressed mice during cued fear recall tests. Repeated social stress abolished the increased fear expression displayed by constitutive CB(1) receptor-deficient mice. The use of mutant mice lacking CB(1) receptors from cortical glutamatergic neurons or from GABAergic neurons indicated that it is the absence of the former CB(1) receptor population that is responsible for the fear responses in socially stressed CB(1) mutant mice. In addition, stress-induced hypolocomotor reactivity was amplified by the absence of CB(1) receptors from GABAergic neurons. Mutant mice lacking CB(1) receptors from serotonergic neurons displayed a higher anxiety but decreased cued fear expression than their wild-type controls. These mutant mice failed to show social stress-elicited increased sucrose preference. This study shows that (i) release of endocannabinoids during stress exposure impedes stress-elicited amplification of cued fear behavior, (ii) social stress opposes the increased fear expression and delayed between-session extinction because of the absence of CB(1) receptors from cortical glutamatergic neurons, and (iii) CB(1) receptors on central serotonergic neurons are involved in the sweet consumption response to repeated stress.Neuropsychopharmacology advance online publication, 21 March 2012; doi:10.1038/npp.2012.36