243 research outputs found
A New MMC Converter With Fault Blocking Capability for HVDC Interconnects
This work proposes a modular multilevel dc/dc converter, named the DC-MMC, that can be conveyed to interconnect HVDC systems of various or comparable voltage levels. Its key elements include: 1) bidirectional power stream; 2) step-up and step-down operation; and 3) bidirectional fault blocking like a dc electrical switch. The part of the DC-MMC is another class of bidirectional single-stage dc/dc converters using interleaved strings of fell sub modules. The DC-MMC operation is broke down and an open circle voltage control procedure that guarantees control adjust of every sub module capacitor by means of coursing air conditioning streams is proposed through fuzzy logic controller. simulation results were investigated in MATLAB programming
Fractures of the Scapula
The scapula plays a critical role in the association between the upper extremity and the axial skeleton. Fractures of the scapula account for 0.4% to 1% of all fractures and have an annual incidence of approximately 10 per 100,000 inhabitants. Scapular fractures typically result from a high-energy blunt-force mechanism and are often associated with other traumatic injuries. The present review focuses on the presentation, diagnosis, and treatment of fractures of the scapula. Indications for surgical treatment of glenoid fossa, scapular neck, and scapular body fractures are presented in detail. Finally, the authors' preferred surgical technique, including positioning, approach, reduction, fixation, and post-operative management, is described
The Spatial and Temporal Structure of Neural Activity across the Fly Brain
What are the spatial and temporal scales of brainwide neuronal activity? We used swept, confocally-aligned planar excitation (SCAPE) microscopy to image all cells in a large volume of the brain of adult Drosophila with high spatiotemporal resolution while flies engaged in a variety of spontaneous behaviors. This revealed neural representations of behavior on multiple spatial and temporal scales. The activity of most neurons correlated (or anticorrelated) with running and flailing over timescales that ranged from seconds to a minute. Grooming elicited a weaker global response. Significant residual activity not directly correlated with behavior was high dimensional and reflected the activity of small clusters of spatially organized neurons that may correspond to genetically defined cell types. These clusters participate in the global dynamics, indicating that neural activity reflects a combination of local and broadly distributed components. This suggests that microcircuits with highly specified functions are provided with knowledge of the larger context in which they operate
Expression Analysis of Novel microRNAs in Rice During High Temperature Stress
MicroRNAs (miRNAs) are small non-coding RNAs which play an important role in regulating the genes involved in plant
growth and development. Several studies showed that miRNAs are involved in plants response to different kinds of
abiotic stresses also. In our previous study, temperature responsive miRNAs were predicted in O.sativa. 27 miRNAs were
predicted to be novel in rice using homology search. In continuation to our previous study, expression of 14 novel
miRNAs was done in shoot and root of 13 days old seedlings of five different rice cultivars using real time PCR. Expression
these miRNAs was analyzed in control and high temperature stress environment. Out of 14 predicted novel miRNAs, two
novel miRNAs- miR157a and miR165a showed expression in all five rice cultivars. Interestingly, miR165a showed a
differential expression pattern among heat tolerant (N22, IR64 and Rasi) and susceptible (Vandana and Sampada)
cultivars suggesting that it might have specific role in high temperature tolerance
Neuronal birthdate reveals topography in a vestibular brainstem circuit for gaze stabilization
Across the nervous system, neurons with similar attributes are topographically organized. This topography reflects developmental pressures. Oddly, vestibular (balance) nuclei are thought to be disorganized. By measuring activity in birthdated neurons, we revealed a functional map within the central vestibular projection nucleus that stabilizes gaze in the larval zebrafish. We first discovered that both somatic position and stimulus selectivity follow projection neuron birthdate. Next, with electron microscopy and loss-of-function assays, we found that patterns of peripheral innervation to projection neurons were similarly organized by birthdate. Finally, birthdate revealed spatial patterns of axonal arborization and synapse formation to projection neuron outputs. Collectively, we find that development reveals previously hidden organization to the input, processing, and output layers of a highly conserved vertebrate sensorimotor circuit. The spatial and temporal attributes we uncover constrain the developmental mechanisms that may specify the fate, function, and organization of vestibulo-ocular reflex neurons. More broadly, our data suggest that, like invertebrates, temporal mechanisms may assemble vertebrate sensorimotor architecture
Score-based Diffusion Models in Function Space
Diffusion models have recently emerged as a powerful framework for generative
modeling. They consist of a forward process that perturbs input data with
Gaussian white noise and a reverse process that learns a score function to
generate samples by denoising. Despite their tremendous success, they are
mostly formulated on finite-dimensional spaces, e.g. Euclidean, limiting their
applications to many domains where the data has a functional form such as in
scientific computing and 3D geometric data analysis. In this work, we introduce
a mathematically rigorous framework called Denoising Diffusion Operators (DDOs)
for training diffusion models in function space. In DDOs, the forward process
perturbs input functions gradually using a Gaussian process. The generative
process is formulated by integrating a function-valued Langevin dynamic. Our
approach requires an appropriate notion of the score for the perturbed data
distribution, which we obtain by generalizing denoising score matching to
function spaces that can be infinite-dimensional. We show that the
corresponding discretized algorithm generates accurate samples at a fixed cost
that is independent of the data resolution. We theoretically and numerically
verify the applicability of our approach on a set of problems, including
generating solutions to the Navier-Stokes equation viewed as the push-forward
distribution of forcings from a Gaussian Random Field (GRF).Comment: 26 pages, 7 figure
Neuronal Birthdate Reveals Topography in a Vestibular Brainstem Circuit for Gaze Stabilization
Across the nervous system, neurons with similar attributes are topographically organized. This topography reflects developmental pressures. Oddly, vestibular (balance) nuclei are thought to be disorganized. By measuring activity in birthdated neurons, we revealed a functional map within the central vestibular projection nucleus that stabilizes gaze in the larval zebrafish. We first discovered that both somatic position and stimulus selectivity follow projection neuron birthdate. Next, with electron microscopy and loss-of-function assays, we found that patterns of peripheral innervation to projection neurons were similarly organized by birthdate. Finally, birthdate revealed spatial patterns of axonal arborization and synapse formation to projection neuron outputs. Collectively, we find that development reveals previously hidden organization to the input, processing, and output layers of a highly conserved vertebrate sensorimotor circuit. The spatial and temporal attributes we uncover constrain the developmental mechanisms that may specify the fate, function, and organization of vestibulo-ocular reflex neurons. More broadly, our data suggest that, like invertebrates, temporal mechanisms may assemble vertebrate sensorimotor architecture
A multi-dimensional approach from seed-to-seed to understand and improve heat stress tolerance in rice
In changing climatic conditions, stress caused by high temperature
poses a serious threat to rice cultivation. Physiological,
biochemical, and molecular analysis of rice cultivars revealed
that Nagina22 (N22) shows lesser reduction in chlorophyll content,
net photosynthetic rate, spikelet fertility and grain yield,
but increased membrane thermal stability, antioxidant enzymes
activity and transpiration rate (E) at high temperature. DREB,
RAB, LEA, and genes associated with hormones signalling were
induced during germination, while OsFd (an iron sulphur cluster
binding protein) and CWIP (cell wall integrity protein) emerged
as high priority candidate genes in seedling and reproductive
stages. Their function is being analysed by transgene expression
and CRISPR/Cas genome editing approaches. Field screening
in polyhouse, late sowing and temperature gradient chamber
for 20 morpho-physiological traits indicated the importance of
both yield and spikelet fertility, and photosynthesis traits. N22
showed the least Heat Susceptibility Index (HSI) for yield/plant,
spikelet fertility, flag leaf SPAD and stomatal conductance, while
Vandana showed the highest HSI for spikelet fertility and flag leaf
temperature. QTLs for HSI of spikelet fertility were identified on
chromosome 1 and HSI of yield per plant on chromosomes 1, 2, 3,
4, 7 and 8; and PV of 6% to 57% using 174 F2-3 Vandana x N22
mapping population. Simultaneously, RNAseq was performed
to identify the genome wide miRNAs and transcriptome of N22
and Vandana from shoot and root after short and long duration
of heat stress treatments; and recovery phase for an eQTL-guided
function-related co-expression analysis to identify the putative
regulators and gene regulatory networks
Deep sequencing of small RNAs reveals ribosomal origin of microRNAs in Oryza sativa and their regulatory role in high temperature
MicroRNAs are small noncoding regulatory RNAs which control gene expression by mRNA degradation or translational repression. They are significant molecular players regulating important biological processes such as developmental timing and stress response. We report here the discovery of miRNAs derived from ribosomal DNA using the small RNA datasets of 16 deep sequencing libraries of rice. Twelve putative miRNAs were identified based on highly stringent criteria of novel miRNA prediction. Surprisingly, 10 putative miRNAs (mi_7403, mi_8435, mi_12675, mi_4266, mi_4758, mi_4218, mi_8200, mi_4644, mi_14291, mi_16235) originated from rDNA of rice chromosome 9. Expression analysis of putative miRNAs and their target genes in heat tolerant and susceptible rice cultivars in control and high temperature treated seedlings revealed differential regulation of rDNA derived miRNAs. This is the first report of rDNA derived miRNAs in rice which indicates their role in gene regulation during high temperature stress in plants. Further studies in this area will open new research challenges and opportunities to broaden our knowledge on gene regulation mechanisms
Quantitative analysis of orthopedic metal artefact reduction in 64-slice computed tomography scans in large head metal-on-metal total hip replacement, a phantom study
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