436 research outputs found

    Constructing Geo-Information Sharing GRID Architecture

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    Development of the Neurochemical Architecture of the Central Complex

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    The central complex represents one of the most conspicuous neuroarchitectures to be found in the insect brain and regulates a wide repertoire of behaviors including locomotion, stridulation, spatial orientation and spatial memory. In this review article, we show that in the grasshopper, a model insect system, the intricate wiring of the fan-shaped body (FB) begins early in embryogenesis when axons from the first progeny of four protocerebral stem cells (called W, X, Y, Z, respectively) in each brain hemisphere establish a set of tracts to the primary commissural system. Decussation of subsets of commissural neurons at stereotypic locations across the brain midline then establishes a columnar neuroarchitecture in the FB which is completed during embryogenesis. Examination of the expression patterns of various neurochemicals in the central complex including neuropeptides, a neurotransmitter and the gas nitric oxide (NO), show that these appear progressively and in a substance-specific manner during embryogenesis. Each neuroactive substance is expressed by neurons located at stereotypic locations in a given central complex lineage, confirming that the stem cells are biochemically multipotent. The organization of axons expressing the various neurochemicals within the central complex is topologically related to the location, and hence birthdate, of the neurons within the lineages. The neurochemical expression patterns within the FB are layered, and so reflect the temporal topology present in the lineages. This principle relates the neuroanatomical to the neurochemical architecture of the central complex and so may provide insights into the development of adaptive behaviors

    Using Data Science Tools for Investigating Chat Logs from the Conti Ransomware Group

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    The main goal of this paper is to showcase some results from a comprehensive data analysis that we did on the cache of chat logs from the notorious ransomware group Conti. The chat logs were made publicly available on February 27, 2022. They were translated from Russian into English, and contain 393 json files with chat logs from the instant messaging service Jabber. We employ a variety of modern data science tools for text mining, natural language processing, network analysis and geospatial analysis to investigate the Conti chat logs so that we can understand the command and control structure of the network and discover any valuable information hidden in the data, such as Bitcoin, IP, email and web addresses, as well as any other information that can lead to further insights into the inner workings of the Conti group

    LiveVV: Human-Centered Live Volumetric Video Streaming System

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    Volumetric video has emerged as a prominent medium within the realm of eXtended Reality (XR) with the advancements in computer graphics and depth capture hardware. Users can fully immersive themselves in volumetric video with the ability to switch their viewport in six degree-of-freedom (DOF), including three rotational dimensions (yaw, pitch, roll) and three translational dimensions (X, Y, Z). Different from traditional 2D videos that are composed of pixel matrices, volumetric videos employ point clouds, meshes, or voxels to represent a volumetric scene, resulting in significantly larger data sizes. While previous works have successfully achieved volumetric video streaming in video-on-demand scenarios, the live streaming of volumetric video remains an unresolved challenge due to the limited network bandwidth and stringent latency constraints. In this paper, we for the first time propose a holistic live volumetric video streaming system, LiveVV, which achieves multi-view capture, scene segmentation \& reuse, adaptive transmission, and rendering. LiveVV contains multiple lightweight volumetric video capture modules that are capable of being deployed without prior preparation. To reduce bandwidth consumption, LiveVV processes static and dynamic volumetric content separately by reusing static data with low disparity and decimating data with low visual saliency. Besides, to deal with network fluctuation, LiveVV integrates a volumetric video adaptive bitrate streaming algorithm (VABR) to enable fluent playback with the maximum quality of experience. Extensive real-world experiment shows that LiveVV can achieve live volumetric video streaming at a frame rate of 24 fps with a latency of less than 350ms

    Assessing prioritization measures for a private land conservation program in the U.S. Prairie Pothole Region

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    Private land conservation has become an important tool for protecting biodiversity and habitat, but methods for prioritizing and scheduling conservation on private land are still being developed. While return on investment methods have been suggested as a potential path forward, the different processes linking private landscapes to the socioeconomic systems in which they are embedded create unique challenges for scheduling conservation with this approach. We investigated a range of scheduling approaches within a return on investment framework for breeding waterfowl and broods in the Prairie Pothole Region of North Dakota, South Dakota, and Montana. Current conservation targeting for waterfowl in the region focuses mostly on the distribution and abundance of breeding waterfowl. We tested whether MaxGain approaches for waterfowl conservation differed from MinLoss approaches in terms of return on investment and which approach performed best in avoiding loss of waterfowl and broods separately. We also examined variation in results based upon the temporal scale of the abundance layers used for input and compared the region's current scheduling approach with results from our simulations. Our results suggested that MinLoss was the most efficient scheduling approach for both breeding waterfowl and broods and that using just breeding waterfowl to target areas for conservation programs might cause organizations to overlook important areas for broods, particularly over shorter timespans. The higher efficiency of MinLoss approaches in our simulations also indicated that incorporating probability of wetland drainage into decision-making improved the overall return on investment. We recommend that future conservation scheduling for easements in the region and for private land conservation in general include some form of return on investment or cost-effective analysis to make conservation more transparent

    Modulation of inflammation by anti-TNF α mAb-dendrimer nanoparticles loaded in tyramine-modified gellan gum hydrogels in a cartilage-on-a-chip model

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    Rheumatoid arthritis (RA) is an autoimmune and chronic inflammatory disease characterized by joint inflammation. Since the inflammatory condition plays an important role in the disease process, it is important to develop and test new therapeutic approaches that specifically target and treat joint inflammation. In this study, a human 3D inflammatory cartilage-on-a-chip model was established to test the therapeutic efficacy of anti-TNFα mAb-CS/PAMAM dendrimer NPs loaded-Tyramine-Gellan Gum in the treatment of inflammation. The results showed that the proposed therapeutic approach applied to the human monocyte cell line (THP-1) and human chondrogenic primary cells (hCH) cell-based inflammation system revealed an anti-inflammatory capacity that increased over 14 days. It was also possible to observe that Coll type II was highly expressed by inflamed hCH upon the culture with anti-TNF α mAb-CS/PAMAM dendrimer NPs, indicating that the hCH cells were able maintain their biological function. The developed preclinical model allowed us to provide more robust data on the potential therapeutic effect of anti-TNF α mAb-CS/PAMAM dendrimer NPs loaded-Ty-GG hydrogel in a physiologically relevant model.The authors thank the financial support under the Norte2020 project (NORTE-08-5369-FSE000044). M. R. C. acknowledges TERM RES Hub Ref. Norte-01-0145-FEDER-02219015 working contract. D. C. F. acknowledges Portuguese Foundation for Science and Technology (FCT) for his phD scholarship (PD/ BD/143081/2018) and F. R. M. for her contract under the Transitional Rule DL 57/2016 (CTTI-57/18-I3BS(5)). C. M. A., D. C. V. and S. C. K. thank the support of FCT (PTDC/BTM-ORG/ 28070/2017). D. C. V acknowledges the CEEC individual contract (CEECIND/00352/2017). S. C. K wishes to record the financial support from EU Framework Programme for Research and Innovation H2020 on FoReCaST under grant agreement no. 668983 and BREAST-IT FCT-Portugal project (PTDC/BTM-ORG/ 28168/2017). The FCT distinction attributed to J. M. O. under the Investigator FCT program (number IF/01285/2015) is also greatly acknowledge

    Silicon Nanophotonic Waveguides for the Mid-Infrared

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    It has recently been shown that silicon nanophotonic waveguides can be used to construct all of the components of a photonic data transmission system on a single chip. These components can be integrated together with CMOS electronics to create complex electronic-photonic integrated circuits. It has also emerged that the high field confinement of silicon nanoscale guides enables exciting new applications, from chipscale nonlinear optics to biosensors and light-force activated devices. To date, most of the experiments in silicon waveguides have been at wavelengths in the near-infrared, ranging from 1.1-2 microns. Here we show that single-mode silicon nano-waveguides can be used at mid-infrared wavelengths, in particular at 4.5 microns, or 2222.2 1/cm. This idea has appeared in theoretical literature, but experimental realization has been elusive. This result represents the first practical integrated waveguide system for the mid-infrared in silicon, and enables a range of new applications.Comment: 18 pages, 4 figure

    Anthropogenic Disturbance and Population Viability of Woodland Caribou in Ontario

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    One of the most challenging tasks in wildlife conservation and management is to clarify how spatial variation in land cover due to anthropogenic disturbance influences wildlife demography and long‐term viability. To evaluate this, we compared rates of survival and population growth by woodland caribou (Rangifer tarandus caribou) from 2 study sites in northern Ontario, Canada that differed in the degree of anthropogenic disturbance because of commercial logging and road development, resulting in differences in predation risk due to gray wolves (Canis lupus). We used an individual‐based model for population viability analysis (PVA) that incorporated adaptive patterns of caribou movement in relation to predation risk and food availability to predict stochastic variation in rates of caribou survival. Field estimates of annual survival rates for adult female caribou in the unlogged ( x̄ = 0.90) and logged ( x̄ = 0.76) study sites recorded during 2010–2014 did not differ significantly (P \u3e 0.05) from values predicted by the individual‐based PVA model (unlogged:  x̄ = 0.87; logged:  x̄ = 0.79). Outcomes from the individual‐based PVA model and a simpler stage‐structured matrix model suggest that substantial differences in adult survival largely due to wolf predation are likely to lead to long‐term decline of woodland caribou in the commercially logged landscape, whereas the unlogged landscape should be considerably more capable of sustaining caribou. Estimates of population growth rates (λ) for the 2010–2014 period differed little between the matrix model and the individual‐based PVA model for the unlogged (matrix model  x̄ = 1.01; individual‐based model x̄ = 0.98) and logged landscape (matrix model x̄ = 0.88; individual‐based model x̄ = 0.89). We applied the spatially explicit PVA model to assess the viability of woodland caribou across 14 woodland caribou ranges in Ontario. Outcomes of these simulations suggest that woodland caribou ranges that have experienced significant levels of commercial forestry activities in the past had annual growth rates 0.96. These differences were strongly related to regional variation in wolf densities. Our results suggest that increased wolf predation risk due to anthropogenic disturbance is of sufficient magnitude to cause appreciable risk of population decline in woodland caribou in Ontario. © 2020 The Authors. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society
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