869 research outputs found
A nonparametric approach for model individualization in an artificial pancreas
The identification of patient-tailored linear time invariant glucose-insulin models is investigated for type 1 diabetic patients, that are characterized by a substantial inter-subject variability. The individualized linear models are identified by considering a novel kernel-based nonparametric approach and are compared with a linear time invariant average model in terms of prediction performance by means of the coefficient of determination, fit, positive and negative max errors, and root mean squared error. Model identification and validation are based on in-silico data collected from the adult virtual population of the UVA/Padova simulator. The data generation involves a protocol designed to produce a sufficient input excitation without compromising patient safety, compatible also with real life scenarios. The identified models are exploited to synthesize an individualized Model Predictive Controller (MPC) for each patient, which is used in an Artificial Pancreas to maintain the blood glucose concentration within an euglycemic range. The MPC used in several clinical studies, synthesized on the basis of a non-individualized average linear time invariant model, is also considered as reference. The closed-loop control performance is evaluated in an in-silico study on the adult virtual population of the UVA/Padova simulator in a perturbed scenario, in which the MPC is blind to random variations of insulin sensitivity in each virtual patient. © 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved
Tabela de vida e fertilidade de Tetrastichus howardi (Hymenoptera: Eulophidae) em pupa de Diatraea saccharalis (Lepidoptera: Crambidae).
Natural based products for cleaning copper and copper alloys artefacts
Copper alloys objects can deteriorate their conservation state through irreversible corrosion. Since in the cultural heritage field every artefact is unique and any loss irreplaceable, solutions for conservation are needed. Hence, there is the necessity to stop the corrosion process with a suitable cleaning and conservation process to avoid further degradation processes without changing its morphological aspect. Chelating solutions are commonly used in chemical cleaning, mainly sodium salts of ethylenediaminetetraacetic acid (EDTA). However, it is resistant to water purification procedures and is not biodegradable. The goal of this study was to see if applying an ecologically friendly chelating agent as an alternative to EDTA cleaning procedures for cultural heritage was suitable. In this study were chosen six natural-based chelators that could be a new green non-toxic alternative to EDTA in corrosion-inhibiting properties. They were tested for cleaning copper artefacts exposed to atmospheric environment in polluted areas. The study considered four amino acids, a glucoheptonate (CSA) and an industrial green chelator (GLDA). The effectiveness was tested on corrosion copper compounds and on laboratory corroded copper sheets. Finally, the cleaning efficacy was tested on four Roman coins and a modern copper painting. To define the cleaning efficacy, surface analytical investigations have been carried out by means ICP-OES, UV-VIS, µ-Raman, spectro-colorimetry, XRD and FTIR. Among the amino acids, alanine was the most effective, showing an unaltered noble patina and a good effective copper recovery from corrosion patinas
Inibição de crescimento de plantas espontâneas por leguminosas herbáceas perenes na Caatinga Mineira - primeiro ano.
Publicado também na: Revista Brasileira de Agroecologia, v. 6. n. 2, dez. 2011
Avaliação de espécies silvestres e cultivares de amendoim para resistência a Enneothrips flavens moulton.
Resistance to thrips (Enneothrips flavens) in wild and amphidiploid Arachis species.
Thrips (Enneothrips flavens) is a pest that causes severe damage and yield losses to peanut crop if not properly controlled. The main control method currently used by farmers is biweekly application of insecticides during crop development, which, in addition to its toxicity, is very costly. Thus, new sources of resistance must be identified in order to reduce the use of insecticides and effectively manage the pest. This study aimed to evaluate the occurrence and symptoms of E. flavens infestations in 12 accessions of 10 wild species of Arachis and nine amphidiploids, as well as to compare their morphoagronomic characteristics to those of commercial cultivars. To this end, we conducted experiments during two summer seasons, using a randomized block design with four replications. We conducted evaluations of the severity of infestation, noting visual symptoms of E. flavens and morphological and reproductive characteristics of the Arachis plants. Results indicated that wild accessions V 7635 (A. vallsii), V 13250 (A. kempff-mercadoi), K 9484 (A. batizocoi), Wi 1118 (A. williamsii), V 14167 (A. duranensis) and V 13751 (A. magna) are the most promising for obtaining useful new amphidiploids. Among the amphidiploids, An 12 (A. batizocoi x A. kempff-mercadoi) 4x, An 9 (A. gregoryi x A. stenosperma) 4x, and An 8 (A. magna x A. cardenasii) 4x showed high level of resistance to E. flavens. The identified thrips resistant wild and amphidiploid Arachis species may be used in future breeding program to produce thrips resistant peanut cultivars
Effect of sire breed on carcass traits measured via ultrasound of crossbred cattle during feedlot
The aim of this study was to evaluate the effect of sire breed on carcass traits measured via ultrasound of crossbred cattle during feedlot. Steers (n=74) and heifers (n=71) produced along two years mating Nellore, ½ Nellore x ½ Angus and ½ Nellore x ½ Caracu dams with Braford (BF), Charbray (CC) and Caracu (CR) were raised grazing tropical grasses until 20 months (mo) of age and then finished in feedlot for 4 mo. Animals with 3 80 ± 49 kg of initial body eight were kept in individual pens and received a total mixed ration containing 74% of Total Digestible Nutrients and 13 % of Crude Protein . Ultrasound carcass scanning was performed in the beginning and end weighings of the feedlot to determine Longissimus ribeye area (REA i and REA f ), Longissimus backfat thickness (BFT i and BFT f ) and rump fat thickness (RFT i and RFT f ). Data were analyzed using mixed model methodology. There were no sire breed effects on REA i and REA f (P>0.05). Progenies of BF, CC and CR obtained average gains in muscle of 10.6 cm 2 , 12.2 cm 2 e 7.9 cm 2 , respectively. No differences (P>0.05) for BFT i and BFT f were found between progenies of BF (4.7 e 8.2 mm), CC 4.1 e 7.8 mm) and CR sires (4.4 e 7.7 mm). Sire breed did not influence on RFT i , however BF progenies had greater RFT f than CC progenies (11.3 vs. 8.9 mm; P<0.10), CR group was intermediate (10.3 mm). Braford breed has superiority in rump fat hickness at the end of feedlot compared to Charbray breed, both being similar to Caracu. The evaluated sire breeds are viable alternatives to be used in crossbreeding programs, presenting carcasses with good qualit
Carcass traits of crossbred steers surgically castrated or immunocastrated.
The aim of this study was to evaluate carcass traits of crossbred steers surgically castrated or immunocastrated. Steers produced along two years from mating Nellore, 1/2 Nellore x 1/2 Angus and 1/2 Nellore x 1/2 Caracu dams with Braford, Charbray and Caracu sires were raised grazing tropical grasses until 20 months of age (n = 80; 40 per treatment; five of each genetic group per treatment), finished feedlot for 4 months (n = 64; 32 per treatment; four of each genetic group per treatment), and harvested at 570 ? 63 kg of body weight. The immunocastration protocol was performed in three applications of vaccine Bopriva (Zoetis; 1 ml subcutaneous each application), targeting the complete castration effect, obtained in the 2nd dose, at 14 months of age, when was also performed surgical castration of the other steers, so that all animals were castrated at the same age. Ultrasound scanning was performed at the beginning and end of the growing period to determine ribeye area (REAi / REAf), backfat thickness (BFTi / BFTf) and rump fat thickness (RFTi / RFTf). Hot carcass weight (HCW) and carcass dressing (CD) were measured at slaughter. Following 24-h chill, Longissimus marbling score (12th-13th ribs section), carcass backfat score (BFS), REAsl and BFTsl were evaluated. Longissimus samples were analyzed for Warner Bratzler shear force (SF) following 0d and 7d aging as well as Hunter L*, a* and b* values following 7d aging. Data were analyzed under a mixed model with sire and dam genetic group (and its iteration), birth season, castration method and backgrounding paddock as fixed effects, and sire nested in sire genetic group as random effect. There were no differences on BFTi, RFTi and RFTf (P > 0.05), however, there was tendency (P 0.05) among animals. The REAsl was superior for immunocastrated steers (81.8 vs. 76.5 cm2; P 0.05). Immunocastration can be used as alternative for surgical castration to improve backfat thickness, however it can negatively affect marbling in crossbred steers. - See more at: https://proceedings.galoa.com.br/imas/papers/carcass-traits-of-crossbred-steers-surgically-castrated-or-immunocastrated#sthash.wVsCYEpG.dpu
Effect of sire breed on carcass and beef quality of crossbred cattle.
The aim of this study was to evaluate the effect of sire breed on beef quality of crossbred cattle. Steers (n=74) and heifers (n=71) produced along two years from mating Nellore, ½ Nellore x ½ Angus and ½ Nellore x ½ Caracu dams with Braford (BF), Charbray (CC) and Caracu (CR) sires were raised grazing tropical grasses until 20 months (mo) of age, finished in feedlot for 4 mo and harvested at 546 ± 60 kg live weight. Hot carcass weight (HCW) and c rcass dressing percentage (CD) were measured at slaughter. Following 24- hour chill, ultimate pH (pH), Longissimus marbling score (12th-13th ribs section), carcass backfat score (1 to 5) and backfat distribution (1 to 3) were evaluated. Longissimus samples were analyzed for Warner Bratzler shear force (SF) after aging for 0 and 7 day (d) as well as Hunter L*, a* and b* values after aging for 7d. Data were analyzed using mixed model methodology. HCW was greater for CC (P0.05), however CC progenies had greater CD (P0.05), however BF progenies had greater backfat distribution score than CC (P0.05). Charbray breed is related to heavier carcasses and possibly with greater dressing percentage whereas Braford breed is associated with better carcass backfat distribution. All sire breeds had similar qualitative attributes of meat
Relationships between residual feed intake and feedlot profitability, growth performance and carcass traits in Brahman cattle.
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