334 research outputs found

    The ultrastructure of meiotic chromosomes of Lilium longiflorum

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    Dynamic Gaussian Splatting from Markerless Motion Capture can Reconstruct Infants Movements

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    Easy access to precise 3D tracking of movement could benefit many aspects of rehabilitation. A challenge to achieving this goal is that while there are many datasets and pretrained algorithms for able-bodied adults, algorithms trained on these datasets often fail to generalize to clinical populations including people with disabilities, infants, and neonates. Reliable movement analysis of infants and neonates is important as spontaneous movement behavior is an important indicator of neurological function and neurodevelopmental disability, which can help guide early interventions. We explored the application of dynamic Gaussian splatting to sparse markerless motion capture (MMC) data. Our approach leverages semantic segmentation masks to focus on the infant, significantly improving the initialization of the scene. Our results demonstrate the potential of this method in rendering novel views of scenes and tracking infant movements. This work paves the way for advanced movement analysis tools that can be applied to diverse clinical populations, with a particular emphasis on early detection in infants

    FURTHER EXPERIMENTS ON THE CAUSE OF SEQUENTIAL NEOPLASTIC CHANGES : THE EFFECTS OF 20-METHYLCHOLANTHRENE ON TRANSPLANTED EPIDERMAL MOUSE PAPILLOMAS AND THE DERIVATIVE CARCINOMAS

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    When crystalline 20-methylcholanthrene (MC) and the cells of tar-induced mouse papillomas (paps.) are injected together into the thigh muscles of mice the carcinogen exerts a marked promoting and chemotactic influence upon the cells while it is dissolving in the tissue fluid. Under such circumstances it strongly stimulates and attracts them, with result they surround and include the scattered crystals in small cysts that later coalesce to form a larger one from which the MC only very gradually escapes. Because of these findings intramuscular tests were made to learn whether MC would hasten the occurrence or increase the number of cancers that now and again derive from paps.; but the tests were repeatedly marred by the extraordinary behavior of such cancerous cells as happened to be already present in the implanted material. They responded far more actively to MC than did the pap. cells and soon took over the growths. Some carcinomas which failed to grow when transplanted alone, or only gradually formed small, regressing nodules, gave rise rapidly to huge growths of similar sort when exposed to MC. To exclude cancerous cells so far as possible from the later tests small grafts of pap. tissue with MC crystals adhering to them were implanted subcutaneously. The pap. cells promptly lined the graft pockets, encysting the crystals incidentally, and formed tumors that enlarged progressively by keratinizing inwards. While they did this their living layer of pap. tissue was continually bathed in dissolved MC throughout many weeks. Despite these apparently favorable conditions the carcinogen neither hastened the occurrence nor increased the number of visible epidermal cancers deriving from the paps. It also failed to bring about sequential malignant changes in the carcinomas. These negative results accord with those already obtained through long exposure of the benign pulmonary adenomas of mice to urethane or methylcholanthrene, agents which rapidly induce these benign tumors yet which were found to be incapable of furthering the cancerous changes to which such growths are prone. They accord also with another previous finding, namely that MC fails to bring on the malignant changes of discontinuous, sequential sort that mammary mouse carcinomas often undergo "spontaneously." Taken together these facts indicate that the change or changes whereby normal cells are converted into benign tumor cells differ in nature from those taking place when they become cancer cells, as also from those occurring when cancer cells undergo further, step-like, malignant changes. A study has been begun to learn whether the widely various carcinomas deriving from benign papillomas differ from these latter and from one and other in their chromosomal content

    THE PLATING OF TUMOR COMPONENTS ON THE SUBCUTANEOUS EXPANSES OF YOUNG MICE : FINDINGS WITH BENIGN AND MALIGNANT EPIDERMAL GROWTHS AND WITH MAMMARY CARCINOMAS

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    A procedure analogous to the plating of bacteria is described whereby some complex tumors have been taken apart and their components separately propagated. It was the outcome of finding that the forcible injection of Locke's solution followed by air can be used to split the subcutaneous connective tissue of sucklings and weanlings horizontally over the entire expanse of their backs or bellies, without inducing any complicating inflammation. Tumor fragments suspended in Locke's were widely scattered on the surfaces thus exposed. Most of them remained where they had lodged on the body wall, and rapidly becoming fixed in place, formed growths protected by the overlying cutaneous layer—which, throughout many weeks, remained unattached either to the wall or to them. The procedure is more searching in its disclosure of tumor constituents than those currently employed, and it has the advantage that it preserves the neoplastic components that it reveals. It has been used thus far only to rescue for experimental purposes transplantable, benign, epidermal papillomas from the hidden carcinomas deriving from their cells, and to set free and maintain the neoplastic components of complex mammary tumors of milk factor type. Success was obtained with such of the latter as were chosen for separate propagation, though successive platings were sometimes required for their isolation. Incidentally the procedure revealed two components in the mammary growths which could not have been discerned by previous methods of search. Each formed tumors peculiar to itself

    Safe zero-cost coercions for Haskell

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    Generative type abstractions – present in Haskell, OCaml, and other languages – are useful concepts to help prevent programmer errors. They serve to create new types that are distinct at compile time but share a run-time representation with some base type. We present a new mechanism that allows for zero-cost conversions between generative type abstractions and their representations, even when such types are deeply nested. We prove type safety in the presence of these conversions and have implemented our work in GHC

    On the Nature of Trapped-Hole States in CdS Nanocrystals and the Mechanism of their Diffusion

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    Recent transient absorption experiments on CdS nanorods suggest that photoexcited holes rapidly trap to the surface of these particles and then undergo diffusion along the rod surface. In this paper, we present a semiperiodic DFT model for the CdS nanocrystal surface, analyze it, and comment on the nature of both the hole-trap states and the mechanism by which the holes diffuse. Hole states near the top of the valence band form an energetic near continuum with the bulk, and localize to the non-bonding sp3^3 orbitals on surface sulfur atoms. After localization, the holes form nonadiabatic small polarons that move between the sulfur orbitals on the surface of the particle in a series of uncorrelated, incoherent, thermally-activated hops at room temperature. The surface-trapped holes are deeply in the weak-electronic coupling limit and, as a result, undergo slow diffusion.Comment: 4 figure

    High concentrations of flavor chemicals are present in electronic cigarette refill fluids.

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    We characterized the flavor chemicals in a broad sample of commercially available electronic cigarette (EC) refill fluids that were purchased in four different countries. Flavor chemicals in 277 refill fluids were identified and quantified by gas chromatography-mass spectrometry, and two commonly used flavor chemicals were tested for cytotoxicity with the MTT assay using human lung fibroblasts and epithelial cells. About 85% of the refill fluids had total flavor concentrations >1 mg/ml, and 37% were >10 mg/ml (1% by weight). Of the 155 flavor chemicals identified in the 277 refill fluids, 50 were present at ≥1 mg/ml in at least one sample and 11 were ≥10 mg/ml in 54 of the refill fluids. Sixty-one% (170 out of 277) of the samples contained nicotine, and of these, 56% had a total flavor chemical/nicotine ratio >2. Four chemicals were present in 50% (menthol, triacetin, and cinnamaldehyde) to 80% (ethyl maltol) of the samples. Some products had concentrations of menthol ("Menthol Arctic") and ethyl maltol ("No. 64") that were 30 times (menthol) and 100 times (ethyl maltol) their cytotoxic concentration. One refill fluid contained cinnamaldehyde at ~34% (343 mg/ml), more than 100,000 times its cytotoxic level. High concentrations of some flavor chemicals in EC refill fluids are potentially harmful to users, and continued absence of any regulations regarding flavor chemicals in EC fluids will likely be detrimental to human health

    Bayesian Analysis of Autoregressive Processes: Time and Frequency Domain

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    A Bayesian approach to inferences in the time and frequency domains is developed for multivariate autoregressive models. Examples are presented to demonstrate the use and limitations of the techniques. The approach handles a very wide class of models, including a rich class of nonstationary (and explosive) models. To the best of my knowledge, the AR spectral analysis approach as described in Chapters IV and V is new.Statistic
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