2,052 research outputs found

    Denoising Diffusion Models on Model-Based Latent Space

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    With the recent advancements in the field of diffusion generative models, it has been shown that defining the generative process in the latent space of a powerful pretrained autoencoder can offer substantial advantages. This approach, by abstracting away imperceptible image details and introducing substantial spatial compression, renders the learning of the generative process more manageable while significantly reducing computational and memory demands. In this work, we propose to replace autoencoder coding with a model-based coding scheme based on traditional lossy image compression techniques; this choice not only further diminishes computational expenses but also allows us to probe the boundaries of latent-space image generation. Our objectives culminate in the proposal of a valuable approximation for training continuous diffusion models within a discrete space, accompanied by enhancements to the generative model for categorical values. Beyond the good results obtained for the problem at hand, we believe that the proposed work holds promise for enhancing the adaptability of generative diffusion models across diverse data types beyond the realm of imagery

    5'-deiodinase activity and circulating thyronines in lactating cows.

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    To investigate the correlation between lactation and thyroid hormone metabolism, the authors studied concentrations of total and free thyroxine (T4 and fT4), triiodothyronine (T3 and fT3), and reverse triiodothyronine (rT3) in plasma and milk, as well as liver and mammary gland 5'-deiodinase (5'D) activity in dry, early, middle, and late lactating dairy cows. Cows in early lactation show lower plasma levels of T4 and rT3 than dry, middle, and late lactating animals, whereas T3 shows the lowest plasma levels in the dry period; free T4 and T3 show a similar pattern. In early lactation there is a clear decrease in liver 5'D associated with a notable increase in mammary 5'D. Concentrations of T4 and T3 in milk drop significantly in the first few days after delivery, whereas rT3 increases up to the fourth month. The findings suggest a relationship between the hypothyroid status of lactating cows and the rearrangement of organ-specific 5'-deiodinase activity related to the maintenance of the udder's function

    Role of prolactin, growth hormone and insulin-like growth factor 1 in mammary gland involution in the dairy cow.

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    Bovine mammary involution, an important process for subsequent lactations, is characterized by loss of epithelial cells by apoptosis, but its hormonal regulation is still not well defined. Prolactin (PRL) and growth hormone (GH) play a specific role on rat mammary gland apoptosis, through insulin-like growth factor 1 (IGF-1) and the IGF binding protein (IGFBP) system. The purpose of our investigation was to determine the possible role of PRL, GH, and IGF-1 on cell survival and on IGFBP-5 expression in the bovine mammary gland. Mammary gland explants were cultured in the presence of cortisol, 17beta-estradiol, progesterone, insulin, PRL, GH, and IGF-1 and with the same treatment but without PRL, GH or IGF-1, respectively. After 24 h of culture, we determined the level of apoptosis through evaluation of DNA laddering in the oligonucleosomal fraction and examined IGFBP-5 messenger RNA (mRNA) expression. The results show a high level of DNA laddering and an increase in IGFBP-5 mRNA content in mammary explants cultured in the absence of PRL, GH, or IGF-I with respect to explants treated with all hormones. Moreover, explants cultured in presence of PRL, GH, or IGF-I show a low level of DNA laddering and IGFBP-5 expression with respect to explants cultured without any hormones. These data demonstrate a relationship between levels of apoptosis and IGFBP-5 mRNA expression in the bovine mammary gland and confirm the involvement of this binding protein programmed cell death and its relationship with the main lactogenic hormones

    Effects of Mechanical Winter Pruning on Vine Performances and Management Costs in a Trebbiano Romagnolo Vineyard: A Five-Year Study

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    Vineyard mechanical winter pruning has been spreading worldwide, and the physiological basis ascribable to it has been consolidated throughout the years. Despite labor savings and reduction of costs having been proven, the demonstration of its economic viability might be challenging. In this context, this work aims to evaluate the vine performances and the costs of different degrees of the mechanization of winter pruning over a five-year trial (2011-2015). In a vineyard of cv. Trebbiano Romagnolo (Vitis vinifera L.) located in northern Italy, three pruning treatments were laid out as follows: (a) manual pruning (MAN); (b) mechanical pre-pruning and simultaneous manual follow-up (MP + F); (c) mechanical pruning without a manual follow-up (MP). The results showed a strong increase in the node number of MP. Nevertheless, the yield compensation factors (i.e., the shoot fruitfulness and cluster weight) limited the increase in productivity. Soluble solids did not differ between the pruning treatments, while titratable acidity resulted slightly higher only on the MP berries. The MP treatment was the most economically convenient, with a vineyard surface of 1.5 hectares, while mechanical pruning with manual finishing resulted more advantageous, compared to manual pruning when the vineyard surface was greater than 2.9 hectares. The agronomic and economic results obtained in this five-year trial suggest that mechanical pruning may be profitably applied also on grapevine varieties characterized by low basal bud fruitfulness, such as Trebbiano Romagnolo

    Investigations on Arthropods Associated with Decay Stages of Buried Animals in Italy

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    Burial could be used by criminals to conceal the bodies of victims, interfering with the succession of sarcosaprophagous fauna and with the evaluation of post-mortem interval. In Italy, no experimental investigation on arthropods associated with buried remains has been conducted to date. A first experimental study on arthropods associated with buried carcasses was carried out in a rural area of Arcavacata di Rende (Cosenza), Southern Italy, from November 2017 to May 2018. Six pig carcasses (Sus scrofa Linnaeus) were used, five of which were buried in 60-cm deep pits, leaving about 25-cm of soil above each carcass, and one was left above ground. One of the buried carcasses was periodically exhumed to evaluate the effects of disturbance on decay processes and on arthropod fauna. The other four carcasses were exhumed only once, respectively after 43, 82, 133, and 171 days. As expected, the decay rate was different among carcasses. Differences in taxa and colonization of arthropod fauna were also detected in the above ground and periodically exhumed carcasses. In carcasses exhumed only once, no arthropod colonization was detected. The results showed that a burial at about 25 cm depth could be sufficient to prevent colonization by sarcosaprophagous taxa and these data could be relevant in forensic cases involving buried corpses

    A parallel pattern for iterative stencil + reduce

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    We advocate the Loop-of-stencil-reduce pattern as a means of simplifying the implementation of data-parallel programs on heterogeneous multi-core platforms. Loop-of-stencil-reduce is general enough to subsume map, reduce, map-reduce, stencil, stencil-reduce, and, crucially, their usage in a loop in both data-parallel and streaming applications, or a combination of both. The pattern makes it possible to deploy a single stencil computation kernel on different GPUs. We discuss the implementation of Loop-of-stencil-reduce in FastFlow, a framework for the implementation of applications based on the parallel patterns. Experiments are presented to illustrate the use of Loop-of-stencil-reduce in developing data-parallel kernels running on heterogeneous systems

    Antimicrobial effects of chemically functionalized and/or photo-heated nanoparticles

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    Antibiotic resistance refers to when microorganisms survive and grow in the presence of specific antibiotics, a phenomenon mainly related to the indiscriminate widespread use and abuse of antibiotics. In this framework, thanks to the design and fabrication of original functional nanomaterials, nanotechnology offers a powerful weapon against several diseases such as cancer and pathogenic illness. Smart nanomaterials, such as metallic nanoparticles and semiconductor nanocrystals, enable the realization of novel drug-free medical therapies for fighting against antibiotic-resistant bacteria. In the light of the latest developments, we highlight the outstanding capabilities of several nanotechnology-inspired approaches to kill antibiotic-resistant bacteria. Chemically functionalized silver and titanium dioxide nanoparticles have been employed for their intrinsic toxicity, which enables them to exhibit an antimicrobial activity while, in a different approach, photo-thermal properties of metallic nanoparticles have been theoretically studied and experimentally tested against several temperature sensitive (mesophilic) bacteria. We also show that it is possible to combine a highly localized targeting with a plasmonic-based heating therapy by properly functionalizing nanoparticle surfaces with covalently linked antibodies. As a perspective, the utilization of properly engineered and chemically functionalized nanomaterials opens a new roads for realizing antibiotic free treatments against pathogens and related diseases
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