3,129 research outputs found

    Generalized minority games with adaptive trend-followers and contrarians

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    We introduce a simple extension of the minority game in which the market rewards contrarian (resp. trend-following) strategies when it is far from (resp. close to) efficiency. The model displays a smooth crossover from a regime where contrarians dominate to one where trend-followers dominate. In the intermediate phase, the stationary state is characterized by non-Gaussian features as well as by the formation of sustained trends and bubbles.Comment: 4 pages, 6 figure

    Nutritional Quality of Meat Analogues: Results From the Food Labelling of Italian Products (FLIP) Project

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    Nowadays, the interest in meat substitutes is increasing, and consumers perceive their nutritional quality better than that of the animal products they intend to resemble. Therefore, this work aimed to investigate the overall nutritional quality of these new products. Regulated information [Regulation (EU) 1169/2011], the presence/absence of nutrition or health claim and organic declarations, the gluten-free indication, and the number of ingredients were collected from the food labels of 269 commercial meat analogues currently sold on the Italian market. Nutritional information of reference animal meat products was used to compare the nutrition profile. As an indicator of the nutritional quality, the Nutri-Score of meat analogues and counterparts was also determined. Plant-based steaks showed significantly higher protein, lower energy, fats and salt contents, and better Nutri-Scores than the other analogues. All the meat analogues showed a higher fibre content than meat products, while plant-based burgers and meatballs had lower protein contents than meat counterparts. Ready-sliced meat analogues showed a lower salt content than cured meats. Overall, all these plant-based products showed a longer list of ingredients than animal meat products. Results from this survey highlighted that plant-based steaks, cutlets, and cured meats have some favourable nutritional aspects compared to animal-based products. However, they cannot be considered a “tout-court” alternative to meat products from a nutritional point of view

    A Mechanistic model for predicting the nutrient requirements and feed biological values for sheep

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    The Cornell Net Carbohydrate and Protein System (CNCPS), a mechanistic model that predicts nutrient requirements and biological values of feeds for cattle, was modified for use with sheep. Published equations were added for predicting the energy and protein requirements of sheep, with a special emphasis on dairy sheep, whose specific needs are not considered by most sheep-feeding systems. The CNCPS for cattle equations that are used to predict the supply of nutrients from each feed were modified to include new solid and liquid ruminal passage rates for sheep, and revised equations were inserted to predict metabolic fecal N. Equations were added to predict fluxes in body energy and protein reserves from BW and condition score. When evaluated with data from seven published studies (19 treatments), for which the CNCPS for sheep predicted positive ruminal N balance, the CNCPS for sheep predicted OM digestibility, which is used to predict feed ME values, with no mean bias (1.1 g/100 g of OM; P > 0.10) and a low root mean squared prediction error (RMSPE; 3.6 g/100 g of OM). Crude protein digestibility, which is used to predict N excretion, was evaluated with eight published studies (23 treatments). The model predicted CP digestibility with no mean bias (-1.9 g/100 g of CP; P > 0.10) but with a large RMSPE (7.2 g/100 g of CP). Evaluation with a data set of published studies in which the CNCPS for sheep predicted negative ruminal N balance indicated that the model tended to underpredict OM digestibility (mean bias of -3.3 g/100 g of OM, P > 0.10; RMSPE = 6.5 g/100 g of OM; n = 12) and to overpredict CP digestibility (mean bias of 2.7 g/100 g of CP, P > 0.10; RMSPE = 12.8 g/100 g of CP; n = 7). The ability of the CNCPS for sheep to predict gains and losses in shrunk BW was evaluated using data from six studies with adult sheep (13 treatments with lactating ewes and 16 with dry ewes). It accurately predicted variations in shrunk BW when diets had positive N balance (mean bias of 5.8 g/d; P > 0.10; RMSPE of 30.0 g/d; n = 15), whereas it markedly overpredicted the variations in shrunk BW when ruminal balance was negative (mean bias of 53.4 g/d, P < 0.05; RMSPE = 84.1 g/d; n = 14). These evaluations indicated that the Cornell Net Carbohydrate and Protein System for Sheep can be used to predict energy and protein requirements, feed biological values, and BW gains and losses in adult sheep

    Human Attention Assessment Using A Machine Learning Approach with GAN-based Data Augmentation Technique Trained Using a Custom Dataset

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    Human–robot interactions require the ability of the system to determine if the user is paying attention. However, to train such systems, massive amounts of data are required. In this study, we addressed the issue of data scarcity by constructing a large dataset (containing ~120,000 photographs) for the attention detection task. Then, by using this dataset, we established a powerful baseline system. In addition, we extended the proposed system by adding an auxiliary face detection module and introducing a unique GAN-based data augmentation technique. Experimental results revealed that the proposed system yields superior performance compared to baseline models and achieves an accuracy of 88% on the test set. Finally, we created a web application for testing the proposed model in real time

    Improving Models for Student Retention and Graduation using Markov Chains

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    Graduation rates are a key measure of the long-term efficacy of academic interventions. However, challenges to using traditional estimates of graduation rates for underrepresented students include inherently small sample sizes and high data requirements. Here, we show that a Markov model increases confidence and reduces biases in estimated graduation rates for underrepresented minority and first-generation students. We use a Learning Assistant program to demonstrate the Markov model's strength for assessing program efficacy. We find that Learning Assistants in gateway science courses are associated with a 9% increase in the six-year graduation rate. These gains are larger for underrepresented minority (21%) and first-generation students (18%). Our results indicate that Learning Assistants can improve overall graduation rates and address inequalities in graduation rates for underrepresented students

    Suspended Multifunctional Nanocellulose as Additive for Mortars

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    Cellulose derivatives have found significant applications in composite materials, mainly because of the increased mechanical performance they ensure. When added to cement-based materials, either in the form of nanocrystals, nanofibrils or micro/nanofibers, cellulose acts on the mixture with fresh and hardened properties, affecting rheology, shrinkage, hydration, and the resulting mechanical properties, microstructure, and durability. Commercial cotton wool was selected as starting material to produce multifunctional nanocelluloses to test as additives for mortars. Cotton wool was oxidized to oxidized nanocellulose (ONC), a charged nanocellulose capable of electrostatic interaction, merging cellulose and nanoparticles properties. Oxidized nanocellulose (ONC) was further functionalized by a radical-based mechanism with glycidyl methacrylate (GMA) and with a mixture of GMA and the crosslinking agent ethylene glycol dimethacrylate (EGDMA) affording ONC-GMA and ONC-GMA-EGDMA, both multifunctional-charged nanocellulose merging cellulose and bound acrylates properties. In this work, only ONC was found to be properly suitable for suspension and addition to a commercial mortar to assess the variation in mechanical properties and water-mortar interactions as a consequence of the modified microstructure obtained. The addition of oxidized nanocellulose caused an alteration of mortar porosity, with a decreased percentage of porosity and pore size distribution shifted towards smaller pores, with a consequent increase in compressive resistance, decrease in water absorption coefficient, and increased percentage of micropores present in the material, indicating a potential improvement in mortar durability

    The Impacts of the City and County of Denver’s Breed Specific Legislation

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    In August of 1989, the City and County of Denver, CO, USA enacted legislation that prohibits the presence of all “pit bull” type dogs (PBTD) (defined in Denver as: American Pit Bull Terrier, American Staffordshire Terrier, or Staffordshire Bull Terrier) within the city limits. In the 30 years the “pit bull ban” has been in place, the City and County of Denver and its animal control agency, Denver Animal Protection, have committed substantial resources to removing PBTDs from the community, including patrolling communities and/or responding to complaints made by neighbors, conducting thorough breed evaluations of suspected PBTDs, and kenneling PBTDs found in the city limits. This Social-Environmental-Economic Impact Assessment (SEEIA) examines how the City and County of Denver’s Breed-Specific Legislation (BSL) policy has impacted the economic and social systems of the Denver community. An economic assessment of BSL identified that the City and County of Denver has spent at least 5.8milliononenforcingthelegislation,withadditionaleconomicanalysesestimatingthatBSLresultedinapproximately5.8 million on enforcing the legislation, with additional economic analyses estimating that BSL resulted in approximately 107 million in lost direct and indirect economic activity related to lost pet care revenue. BSL in the City and County Denver has resulted in an extended length of stay for PBTDs in the care of animal shelters and also places additional strain on transfer partnerships with shelters in surrounding communities. An estimated $1 million has been spent by shelters in surrounding communities to care for the PBTDs that are transferred as a result of BSL. An assessment of the social impacts of BSL determined that the removal of a single breed of dog is inconsistent with the documented benefits of increasing opportunities for pet-keeping in community. Furthermore, the disproportionate enforcement of BSL in underserved communities and communities of color perpetuates historic trends of discrimination and marginalization in the U.S. and negatively impacts social cohesion of these communities. Despite some of the more negative impacts of the legislation, there appear to be a number of social factors that have sustained Denver’s “pit bull” ban. While in the minority of opinions, 19.4% of Denver residents who participated in an online survey about BSL (n = 252) said that the City and County of Denver’s breed ban positively impacted their perception of Denver and 24.6% of Denver residents said that the breed ban makes them feel safer. This perceived increase in sense of safety, even if only reported for a minority percentage of Denver residents, may continue to serve as the primary reason for policymakers to continue the ban in the present day (Maher, 2009, September 24). The breed ban’s prioritization of human public safety at the expense of the welfare of a specific type of dog, particularly without a substantial impact on the former, represents a diversion from the components that contribute to a Humane Community. In conclusion, we recommend alternatives to BSL that will address the root causes of the issue of dangerous dogs, including: building the City and County of Denver\u27s capacity to support residents in caring for their pets by identifying and expanding pet-support infrastructure such as affordable and accessible veterinary and behavior services, implementing robust non-breed-specific dangerous dog laws, and implementing evidence-based interventions for challenges to social cohesion and interpersonal and interspecies violence

    Desenvolvimento e avaliação de uma biblioteca de alimentos tropicais para o modelo "Sistema de Carboidrato e Proteína Líquidos" da Universidade de Cornell

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    The Cornell Net Carbohydrate and Protein System (CNCPS) model has been increasingly used in tropical regions for dairy and beef production. However, the lack of appropriate characterization of the feeds has restricted its application. The objective of this study was to develop and evaluate a feed library containing feeds commonly used in tropical regions with characteristics needed as inputs for the CNCPS. Feed composition data collected from laboratory databases and from experiments published in scientific journals were used to develop this tropical feed library. The total digestible nutrients (TDN) predicted at 1x intake of maintenance requirement with the CNCPS model agreed with those predicted by the Weiss et al. (1992) equation (r² of 92.7%, MSE of 13, and bias of 0.8%) over all feeds. However, the regression r² of the tabular TDN values and the TDN predicted by the CNCPS model or with the Weiss equation were much lower (58.1 and 67.5%, respectively). A thorough comparison between observed and predicted TDN was not possible because of insufficient data to characterize the feeds as required by our models. When we used the mean chemical composition values from the literature data, the TDN predicted by our models did not agree with the measured values. We conclude using the TDN values calculated using the Weiss equation and the CNCPS model that are based on the actual chemical composition of the feeds result in energy values that more accurately represent the feeds being used in specific production situations than do the tabular values. Few papers published in Latin America journals that were used in this study reported information need by models such as the CNCPS.O uso do Sistema de Carboidrato e Proteina Líquidos da Universidade de Cornell (CNCPS) tanto para produção de leite como carne tem aumentado durante o últimos anos nas regiões tropicais. Entretanto, a falta de uma caracterização adequada de alimentos tem restringido o seu uso corretamente. Esse trabalho teve como objetivo principal o desenvolvimento e a avaliação de uma tabela de composição de alimentos utilizados nas condições tropicais. Os dados da composição desses alimentos foram baseados nas informações necessárias para o uso do modelo CNCPS desenvolvido pela Universidade de Cornell, USA. A composição desses alimentos foi obtida através de análises realizadas em laboratórios e de experimentos publicados em revistas científicas. Os nutrientes digestíveis totais (NDT) estimados através da composição de carboidratos e proteina dos alimentos pela equação de Weiss et al. (1992) e pelo modelo CNCPS foram comparados com os valores da tabela. O NDT estimado ao nível de mantença (1x) com o modelo CNCPS obteve valores próximos aos estimados pela equação de Weiss et al. (1992) (r² = 92.7% e bias = 0.8%). Entretanto, o r² da regressão entre os valores de NDT da tabela e o estimado pelo CNCPS e por Weiss foram menores (58.1 e 67.5%, respectivamente). Uma comparação completa entre os valores observados e preditos não foi possível devido a falta de caracterização dos alimentos conforme necessário pelos modelos testados. Quando os valores médios de literatura foram utilizados, a correlação entre o NDT estimado e o observado foi muito baixa. Concluímos que os valores de NDT estimados por Weiss e modelo CNCPS fornecem melhores estimativas de NDT do que os valores de tabela. A maioria dos trabalhos publicados que foram avaliados nesse estudo raramente incluíam informações necessárias para modelos como o CNCPS

    The Impacts of the City and County of Denver’s Breed Specific Legislation

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    In August of 1989, the City and County of Denver, CO, USA enacted legislation that prohibits the presence of all “pit bull” type dogs (PBTD) (defined in Denver as: American Pit Bull Terrier, American Staffordshire Terrier, or Staffordshire Bull Terrier) within the city limits. In the 30 years the “pit bull ban” has been in place, the City and County of Denver and its animal control agency, Denver Animal Protection, have committed substantial resources to removing PBTDs from the community, including patrolling communities and/or responding to complaints made by neighbors, conducting thorough breed evaluations of suspected PBTDs, and kenneling PBTDs found in the city limits. This Social-Environmental-Economic Impact Assessment (SEEIA) examines how the City and County of Denver’s Breed-Specific Legislation (BSL) policy has impacted the economic and social systems of the Denver community. An economic assessment of BSL identified that the City and County of Denver has spent at least 5.8milliononenforcingthelegislation,withadditionaleconomicanalysesestimatingthatBSLresultedinapproximately5.8 million on enforcing the legislation, with additional economic analyses estimating that BSL resulted in approximately 107 million in lost direct and indirect economic activity related to lost pet care revenue. BSL in the City and County Denver has resulted in an extended length of stay for PBTDs in the care of animal shelters and also places additional strain on transfer partnerships with shelters in surrounding communities. An estimated $1 million has been spent by shelters in surrounding communities to care for the PBTDs that are transferred as a result of BSL. An assessment of the social impacts of BSL determined that the removal of a single breed of dog is inconsistent with the documented benefits of increasing opportunities for pet-keeping in community. Furthermore, the disproportionate enforcement of BSL in underserved communities and communities of color perpetuates historic trends of discrimination and marginalization in the U.S. and negatively impacts social cohesion of these communities. Despite some of the more negative impacts of the legislation, there appear to be a number of social factors that have sustained Denver’s “pit bull” ban. While in the minority of opinions, 19.4% of Denver residents who participated in an online survey about BSL (n = 252) said that the City and County of Denver’s breed ban positively impacted their perception of Denver and 24.6% of Denver residents said that the breed ban makes them feel safer. This perceived increase in sense of safety, even if only reported for a minority percentage of Denver residents, may continue to serve as the primary reason for policymakers to continue the ban in the present day (Maher, 2009, September 24). The breed ban’s prioritization of human public safety at the expense of the welfare of a specific type of dog, particularly without a substantial impact on the former, represents a diversion from the components that contribute to a Humane Community. In conclusion, we recommend alternatives to BSL that will address the root causes of the issue of dangerous dogs, including: building the City and County of Denver\u27s capacity to support residents in caring for their pets by identifying and expanding pet-support infrastructure such as affordable and accessible veterinary and behavior services, implementing robust non-breed-specific dangerous dog laws, and implementing evidence-based interventions for challenges to social cohesion and interpersonal and interspecies violence
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