Dynamic Mechanical Analysis and Three-Body Abrasive Wear Behaviour of Thermoplastic Copolyester Elastomer Composites

Various amounts of short fibers (glass and carbon) and particulate fillers like polytetrafluoroethylene (PTFE), silicon carbide (SiC), and alumina (Al2O3) were systematically introduced into the thermoplastic copolyester elastomer (TCE) matrix for reinforcement purpose. The mechanical properties such as storage modulus, loss modulus, and Tan δ by dynamic mechanical analysis (DMA) and three-body abrasive wear performance on a dry sand rubber wheel abrasion tester have been investigated. For abrasive wear study, the experiments were planned according to L27 orthogonal array by considering three factors and three levels. The complex moduli for TCE hybrid composites were pushed to a higher level relative to the TCE filled PTFE composite. At lower temperatures (in the glassy region), the storage modulus increases with increase in wt.% of reinforcement (fiber + fillers) and the value is maximum for the composite with 40 wt.% reinforcement. The loss modulus and damping peaks were also found to be higher by the incorporation of SiC and Al2O3 microfillers. The routine abrasive wear test results indicated that TCE filled PTFE composite exhibited better abrasion resistance. Improvements in the abrasion resistance, however, have not been achieved by short-fiber and particlaute filler reinforcements. From the Taguchi’s experimental findings, optimal combination of control factors were obtained for minimum wear volume and also predictive correlations were proposed. Further, the worn surface morphology of the samples was discussed

Anti-stress activity of Ocimum sanctum and alprazolam in animal models

Background: Stress is the physiological, psychological and behavioral response by individuals when they perceive a lack of equilibrium between the demands placed upon them and their ability to meet those demands, which over a period of time leads to ill health. There are several ways of coping with stress. Some techniques of time management may help a person to control stress.Methods: Forced swim test- mice were randomized into two groups according to the body weights. Each group contains six animals. Each individual animal was allowed to swim inside the jar (25-12-25 cm) containing fresh water up to 15 cm height. Mice were allowed swim for 6 min. After initial struggle to escape the animal became immobile. Total immobility period was measured. Rotarod test- mice were randomized into two groups according to body weights. Each group contains six animals. Rats were placed on the lanes. Latency period was recorded at which each rat falls off the rod.Results: In first experiment, anti-stress activity of Ocimum sanctum in mice was demonstrated by measuring the immobility period during forced swim test and in the second experiment the measurement of the latency period of rats in rotarod apparatus was performed. Both the experimental procedures were compared with standard anti stress drug alprazolam.Conclusions: The present study suggests that Ocimum sanctum possess significant anti stress activity but less when compared to alprazolam

Cortical glutamatergic projection neuron types contribute to distinct functional subnetworks

The cellular basis of cerebral cortex functional architecture remains not well understood. A major challenge is to monitor and decipher neural network dynamics across broad cortical areas yet with projection neuron (PN)-type resolution in real time during behavior. Combining genetic targeting and wide-field imaging, we monitored activity dynamics of subcortical-projecting (PTFezf2) and intratelencephalic-projecting (ITPlxnD1) types across dorsal cortex of mice during different brain states and behaviors. ITPlxnD1 and PTFezf2 neurons showed distinct activation patterns during wakeful resting, spontaneous movements, and upon sensory stimulation. Distinct ITPlxnD1 and PTFezf2 subnetworks were dynamically tuned to different sensorimotor components of a naturalistic feeding behavior, and optogenetic inhibition of subnetwork nodes disrupted specific components of this behavior. Lastly, ITPlxnD1 and PTFezf2 projection patterns are consistent with their subnetwork activation patterns. Our results show that, in addition to the concept of columnar organization, dynamic areal and PN type-specific subnetworks are a key feature of cortical functional architecture linking microcircuit components with global brain networks

Nature of gene action for kernel yield and its component traits in maize (Zea mays L.)

Towards understanding the nature of gene action for kernel yield and its components traits, a set of 45 F1 hybrids generated by adopting diallel mating design (Method IV and Model I) involving 10 inbred lines were tested across three seasons for their performance and combining ability. Combining ability analysis revealed that the mean sum of squares due to general and specific combining ability were significant indicating the contribution of both additive and non-additive gene action in controlling days to 50% flowering, days to 50% silking, anthesis-silking interval, days to maturity, plant height, SPAD chlorophyll meter reading, specific leaf area, cob length, cob girth, number of kernel rows per cob, number of kernels per row, 100 kernel weight, harvest index and kernel yield. Estimates of components of variances (σ2GCA and σ2SCA) and ratio of σ2GCA/σ2SCA indicated the predominance of non-additive gene action for all the characters studied. Among the inbred lines, BML 2, DFTY, Heypool and PDM 1474 were found to be the best general combiners across seasons for kernel yield and most of yield components as well as developmental characters. DFTY, Heypool, PDM 1452 and PAM 1474 were identified as good general combiners for earliness. Among the top 20 best performing hybrids, BML 15 × PDM 1452, BML 15 × PDM 1474 and BML 7 × DFTY were rated as promising hybrids based on their superior performance and sca effects for kernel yield and most of the yield components. These hybrids could be recommended for commercial cultivation after extensive testing in multilocation trials

Pyramidal cell types drive functionally distinct cortical activity patterns during decision-making

Understanding how cortical circuits generate complex behavior requires investigating the cell types that comprise them. Functional differences across pyramidal neuron (PyN) types have been observed within cortical areas, but it is not known whether these local differences extend throughout the cortex, nor whether additional differences emerge when larger-scale dynamics are considered. We used genetic and retrograde labeling to target pyramidal tract, intratelencephalic and corticostriatal projection neurons and measured their cortex-wide activity. Each PyN type drove unique neural dynamics, both at the local and cortex-wide scales. Cortical activity and optogenetic inactivation during an auditory decision task revealed distinct functional roles. All PyNs in parietal cortex were recruited during perception of the auditory stimulus, but, surprisingly, pyramidal tract neurons had the largest causal role. In frontal cortex, all PyNs were required for accurate choices but showed distinct choice tuning. Our results reveal that rich, cell-type-specific cortical dynamics shape perceptual decisions

The posterior parietal cortex as integrative hub for whisker sensorimotor information

Our daily life consists of a continuous interplay between incoming sensory information and outgoing motor plans. Particularly during goal-directed behavior and active exploration of the sensory environment, brain circuits are merging sensory and motor signals. This is referred to as sensorimotor integration and is relevant for locomotion, vision or tactile exploration. The somatosensory (tactile) system is an attractive modality to study sensorimotor integration in health and disease, motivated by the need for revolutionary technology that builds upon conceptual understanding of sensorimotor integration, such as brain-machine-interfaces and neuro-prosthetics. In this perspective, we focus on the rat whisker system and put forward the posterior parietal cortex as a potential circuit where sensorimotor integration could occur during active somatosensation

Xanthoma Disseminatum Presenting with Hoarseness

Introduction: Xanthoma disseminatum (XD) is a rare, benign, non-Langerhans cell histiocytic disorder with unknown etio-pathology. It manifests with multiple, grouped, red-brown to yellow papules and nodules involving the skin, mucous membranes, and internal organs with a predilection for flexures and the face.  Case Report: We report a patient who presented with disseminated xanthomatous papules and nodules involving the face, neck, trunk, axilla, groin, and oral cavity, along with hoarseness of voice. Video laryngoscopy revealed multiple yellowish nodules over the base of the tongue, vallecula, laryngeal surface of the epiglottis, ary-epiglottic folds, interarytenoid region, and subglottic region. Histopathology was suggestive of  xanthoma disseminatum and the patient was treated with tablet acitretin 25mg daily for three months without any response. Following this, the patient was prescribed tablet thalidomide 100 mg daily without any significant improvement at the end of two months.  Conclusion: Xanthoma disseminatum is a very rare form of non-Langerhans cell histiocytosis that classically presents with cutaneous xanthomas, mucosal xanthomas, and diabetes insipidus. Hoarseness of voice due to lesions involving the larynx is a rare symptom. Because the disease has punctated, numerous relapses and causes morbidity to the patient, its multisystem manifestations have to be known. Therefore, xanthoma disseminatum has to be kept in mind as a differential  diagnosis for hoarseness of voice

Functional architecture and encoding of tactile sensorimotor behavior in rat posterior parietal cortex

The posterior parietal cortex (PPC) in rodents is reciprocally connected to primary somatosensory and vibrissal motor cortices. The PPC neuronal circuitry could thus encode and potentially integrate incoming somatosensory information and whisker motor output. However, the information encoded across PPC layers during refined sensorimotor behavior remains largely unknown. To uncover the sensorimotor features represented in PPC during voluntary whisking and object touch, we performed loose-patch single-unit recordings and extracellular recordings of ensemble activity, covering all layers of PPC in anesthetized and awake, behaving male rats. First, using single-cell receptive field mapping, we revealed the presence of coarse somatotopy along the mediolateral axis in PPC. Second, we found that spiking activity was modulated during exploratory whisking in layers 2-4 and layer 6, but not in layer 5 of awake, behaving rats. Population spiking activity preceded actual movement, and whisker trajectory endpoints could be decoded by population spiking, suggesting that PPC is involved in movement planning. Finally, population spiking activity further increased in response to active whisker touch but only in PPC layers 2-4. Thus, we find layer-specific processing, which emphasizes the computational role of PPC during whisker sensorimotor behavior.SIGNIFICANCE STATEMENT The posterior parietal cortex (PPC) is thought to merge information on motor output and sensory input to orchestrate interaction with the environment, but the function of different PPC microcircuit components is poorly understood. We recorded neuronal activity in rat PPC during sensorimotor behavior involving motor and sensory pathways. We uncovered that PPC layers have dedicated function: motor and sensory information is merged in layers 2-4; layer 6 predominantly represents motor information. Collectively, PPC activity predicts future motor output, thus entailing a motor plan. Our results are important for understanding how PPC computationally processes motor output and sensory input. This understanding may facilitate decoding of brain activity when using brain-machine interfaces to overcome loss of function after, for instance, spinal cord injury