733 research outputs found
Optimal estimation for discrete time jump processes
Optimum estimates of nonobservable random variables or random processes which influence the rate functions of a discrete time jump process (DTJP) are obtained. The approach is based on the a posteriori probability of a nonobservable event expressed in terms of the a priori probability of that event and of the sample function probability of the DTJP. A general representation for optimum estimates and recursive equations for minimum mean squared error (MMSE) estimates are obtained. MMSE estimates are nonlinear functions of the observations. The problem of estimating the rate of a DTJP when the rate is a random variable with a probability density function of the form cx super K (l-x) super m and show that the MMSE estimates are linear in this case. This class of density functions explains why there are insignificant differences between optimum unconstrained and linear MMSE estimates in a variety of problems
Unreflective use of old data sources produced echo chambers in the water-electricity nexus
This meta-analysis of over 2,400 papers tracks the influence of older publications that have 'echoed' through the decades, cited in countless publications and creating a potentially false confirmation bias. Echo chambers in science describe the amplification and repetition of information within closed networks. Frequently used data sources can cause echo chambers as scientists keep reading similar outputs from different sources, creating false perceptions of certainty and variety of data sources. We show this effect by studying the scientific and grey literature on water use by electricity systems. The power sector is the largest contributor to anthropogenic carbon emissions and the second largest water consumer. We have assessed the scope and references of 2,426 papers and created a citation network to trace original data sources. Most data sources used for the last 30 years originate from a few old US publications, recently also Chinese, that echo through publications. This echo effect, also reflected in recent scientific publications, creates a confirmation bias, also facilitating double counting of the water intensities of electricity generation. This example from sustainability science warns of the risk of echo chambers in other scientific disciplines
Thamnophis eques (Mexican Garter Snake). Diet.
On 27 September 2018 at 1651 h, we captured an adult male T. eques that regurgitated a partially digested mouse pup. Analysis of rodent guard hair shows a lanceolate pattern of cuticular scales that is characteristic of Peromyscus melanotis. Our record increases the small mammals known to be consumed by snake T. eques to three species
NIRS potential use for the determination of natural resources quality from dehesa (acorn and grass) in Montanera system for Iberian pigs.
NIRS technology has been used as an alternative to conventional methods to determinate the content of nutrients of acorns and grass from dehesa ecosystem. Dry matter (DM), crude fat (CF), crude protein (CP), starch, total phenolic compounds (TP), α-tocopherol, γ-tocopherol, fatty acids, neutral detergent fiber (NDF), total antioxidant activity (TAA) and total energy (TE) were determined by conventional methods for later development of NIRS predictive equations. The NIR spectrum of each sample was collected and for all studied parameters, a predictive model was obtained and external validated. Good prediction equations were obtained for moisture, crude fat, crude protein, total energy and γ-tocopherol in acorns samples, with high coefficients of correlation (1-VR) and low standard error of prediction (SEP) (1-VR=0.81, SEP=2.62; 1-VR=0.92, SEP=0.54; 1-VR=0.86, SEP=0.47; 1-VR=0.84, SEP=0.2; 1-VR=0.88, SEP=5.4, respectively) and crude protein, NDF, α-tocopherol and linolenic acid content in grass samples (1-VR=0.9, SEP=1.99; 1-VR=0.87, SEP=4.13; 1-VR=0.76, SEP=10.9; 1-VR=0.82, SEP=0.6, respectively). Therefore, these prediction models could be used to determinate the nutritional composition of Montanera natural resources
Periodontal Inflammation and Its Relationship with the Risk of Cardiovascular Diseases: Literature Review
For dental practice today, it has become important to emphasize the relevance of periodontal inflammation and oral microorganisms in the development and progression of atherosclerosis and cardiovascular diseases. Generally, the focus on PI as a causal factor of CVD is due to the great complexity and interaction that present the Gram-negative bacteria characteristic of chronic periodontal disease with the vast vascularization of the stomatognathic system. In many recent studies, researchers examined the association at the cellular and molecular level between periodontal and cardiovascular diseases. Although the specific causal correlation as a determining risk factor has not been established, it seems that periodontal disease is associated with several systemic diseases. In this connection, atherosclerosis is important in recent years. There is a possibility of an association documented in several field investigations, and this one refers to a systemic bacteremia caused by poor oral hygiene, which in turn can cause bacterial growth on the atherosclerotic plaques located in the coronary arteries, which possibly
Solid-State Transformer for Energy Efficiency Enhancement
The rapid evolution of power electronic solutions in all around the globe brings a common problem, which is the adoption of nonlinear loads. This fact carries out a strong impact over the quality of power systems and consequently on energy efficiency, since nonlinear loads act as sources of harmonic currents that flow to other loads or even sources, causing non-optimal performance in their operation. Nowadays, conventional transformers are limited to just manage (increase or decrease) voltage level, but they are not able to deal with power quality events, such as harmonics, sag, swell, among others. Hence, there is a need to incorporate a versatile smart device to deal with the challenges previously described for a smart grid environment. This chapter introduces a solid-state transformer (SST) with topology of multilevel cascade H bridge converter as a solution. SST is an emerging technology that has the advantages of low volume, low weight, fault isolation, and other management features. Within its fundamental operation, this chapter presents a detailed description of a SST system comprising communication and control, highlighting their main advantages in comparison with conventional transformer such as mitigation of waveform harmonic distortion, allowance of integration of distributed generation, and bi-directional power flow
Comparison of Cytokine Responses in Ecuadorian Children Infected with Giardia, Ascaris, or Both Parasites.
More than 2 billion people are infected with parasites globally, and the majority have coinfections. Intestinal protozoa and helminths induce polarizing CD4(+) T-helper cell 1 (Th1) mediated cytokine responses within the host. Such immune polarization may inhibit the ability of the host to mount an adequate immune response for pathogen clearance to concurrent pathogens. The current study evaluated the plasma cytokine profile in Ascaris and Giardia coinfected children compared with Giardia- and Ascaris-only infected children. Fecal samples and blood samples were collected from asymptomatic 3-year-old children living in the district of Quininde, Ecuador. Stool samples that tested positive for Giardia lamblia-only, Ascaris lumbricoides-only, or G. lamblia and A. lumbricoides coinfections were confirmed by quantitative real-time polymerase chain reaction. Plasma samples from the study subjects were used to quantitate cytokines. A total of 39 patients were evaluated. Children with coinfection had a significant decrease in Th1 cytokine production, interleukin 2 (IL-2) (P < 0.05), IL-12 (P < 0.05), and tumor necrosis factor alpha (P < 0.05) compared with Giardia-only infected children. Coinfected children had an increase in IL-10/interferon gamma (IFN-γ) ratio compared with uninfected (P < 0.05) and Ascaris alone (P < 0.05). The increased IL-10/IFN-γ ratio in the setting of decreased Th1 cytokine response indicates Th2 polarization in the coinfected group. Reduced Th1 cytokines in children coinfected with Ascaris and Giardia may impair the host's ability to eradicate Giardia infection leading to chronic giardiasis
Efeito das condições de cura no comportamento da resistência à compressão em resíduos de cerâmica ativados por álcali
The industrial sector is responsible for the generation of a large amount of solid waste, of which some is partially recycled, but the majority is deposited in landfills or landfills causing various negative impacts on the environment. Alkaline cements are attracting growing interest for their potential to allow the industry to operate within the constraints imposed on CO2 emissions. The objective of this research was to know the effect of different curing conditions on the compressive strength behavior of alkaline activated ceramic residues. As a result, it was determined that an alkali-activated matrix is significantly influenced when cured at a temperature of 70 ° C, reaching, at 90 days of age, a compressive strength of up to 39.3 MPa in contrast to 27.08 MPa. when curing was carried out in environmental conditions of 20 ° C (± 0.5 ° C) and 60% (± 5%) of relative humidity (RH). This work was complemented with a microstructural analysis that included Scanning Electron Microscopy (SEM) and X-ray Energy Dispersion Analyzer (EDX).El sector industrial es responsable de la generación de una gran cantidad de residuos
sólidos, de los cuales algunos son parcialmente reciclados, pero la mayoría son
depositados en vertederos o rellenos sanitarios provocando diversos impactos negativos
en el medio ambiente. Los cementos alcalinos están atrayendo un interés creciente por su
potencial para permitir que la industria opere dentro de las limitaciones impuestas a las
emisiones de CO2. La presente investigación tuvo como objetivo conocer el efecto de
diferentes condiciones de curado sobre el comportamiento de resistencia a compresión de
los residuos cerámicos activados alcalinamente. Como resultado se determinó que una
matriz álcali-activada es significativamente influenciada cuando se cura con una
temperatura de 70°C alcanzando, a los 90 días de edad, una resistencia a la compresión de
hasta 39,3 MPa en contraste con 27,08 MPa cuando el curado se realizó en condiciones
ambientales de 20°C (± 0,5 ° C) y 60% (± 5%) de humedad relativa (RH). Este trabajo se
complementó con un análisis microestructural que incluyó Microscopía electrónica de
barrido (SEM) y Analizador de dispersión de energía de rayos X (EDX).O setor industrial é responsável pela geração de grande quantidade de resíduos sólidos, alguns
deles parcialmente reciclados, mas a maior parte é depositada em aterros ou aterros sanitários
causando diversos impactos negativos ao meio ambiente. Os cimentos alcalinos estão atraindo
cada vez mais interesse por seu potencial de permitir que a indústria opere dentro das restrições
impostas às emissões de CO2. O objetivo desta pesquisa foi conhecer o efeito de diferentes
condições de cura no comportamento da resistência à compressão de resíduos cerâmicos alcalinos
ativados. Como resultado, determinou-se que uma matriz alcalina ativada é significativamente
influenciada quando curada a uma temperatura de 70 ° C, atingindo, aos 90 dias de idade, uma
resistência à compressão de até 39,3 MPa em contraste com 27,08 MPa. quando a cura foi
realizada em condições ambientais de 20 ° C (± 0,5 ° C) e 60% (± 5%) de umidade relativa (UR).
Este trabalho foi complementado com uma análise microestrutural que incluiu Microscopia
Eletrônica de Varredura (MEV) e Analisador de Dispersão de Energia de Raios-X (EDX)
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