502 research outputs found
See-and-avoid quadcopter using fuzzy control optimized by cross-entropy
In this work we present an optimized fuzzy visual servoing system for obstacle avoidance using an unmanned aerial vehicle. The cross-entropy theory is used to optimise the gains of our controllers. The optimization process was made using the ROS-Gazebo 3D simulation with purposeful extensions developed for our experiments. Visual servoing is achieved through an image processing front-end that uses the Camshift algorithm to detect and track objects in the scene. Experimental flight trials using a small quadrotor were performed to validate the parameters estimated from simulation. The integration of cross- entropy methods is a straightforward way to estimate optimal gains achieving excellent results when tested in real flights
Spectrophotometric and Electrochemical Assessment of the Antioxidant Capacity of Aqueous and Ethanolic Extracts of Citrus Flavedos
Citrus peel residues are of great interest due to the use of their extracted compounds in the food, pharmaceutical and cosmetic industries, mainly due to their antioxidant properties. The flavedo of this peel is especially relevant in modern culinary uses. The antioxidant capacity of the water and ethanolic extracts of the flavedos of ten peels was measured by a spectrophotometric assay and two electrochemical assays. The Folin–Ciocalteu values and ascorbic acid contents were also determined. From the results, it was concluded that the polyphenols extracted from the flavedos have antioxidant activities that occur through single-electron-transfer (SET) mechanisms rather than SET+ hydrogen atom transfer mechanisms. The polyphenols with high polarities extracted in the water constituted the least abundant fraction, and were better antioxidants than those with lower polarity extracted in the ethanol, which constituted the most abundant fraction
The Solar Disk at High Energies
High energy cosmic rays illuminate the Sun and produce an image that could be observed in up to five different
channels: a cosmic-ray shadow (whose energy dependence has been studied by HAWC); a gamma-ray flux
(observed at E 200 GeV by Fermi-LAT); a muon shadow (detected by ANTARES and IceCube); a neutron flux
(undetected, as there are no hadronic calorimeters in space); a flux of high energy neutrinos. Since these signals are
correlated, the ones already observed can be used to reduce the uncertainty in the still undetected ones. Here we
define a simple setup that uses the Fermi-LAT and HAWC observations to imply very definite fluxes of neutrons
and neutrinos from the solar disk. In particular, we provide a fit of the neutrino flux at 10 GeV–10 TeV that
includes its dependence on the zenith angle and on the period of the solar cycle. This flux represents a neutrino
floor in indirect dark matter searches. We show that in some benchmark models the current bounds on the dark
matter–nucleon cross section push the solar signal below this neutrino floor.Spanish GovernmentJunta de Andalucia
PID2019-107844GB-C21/AEI/10.13039/501100011033
FQM 101
P18-FR-505
Heartworm Disease (Dirofilaria immitis) and Their Vectors in Europe – New Distribution Trends
Cardiopulmonary dirofilariasis is a cosmopolitan disease caused by Dirofilaria immitis, which affects mainly canids and felids. Moreover, it causes zoonotic infections, producing pulmonary dirofilariasis in humans. Heartworm disease is a vector-borne transmitted disease, thus transmission depends on the presence of competent mosquito species, which is directly related to favorable climate conditions for its development and survival. Cardiopulmonary dirofilariasis is mainly located in countries with temperate and tropical climates. Europe is one of the continents where animal dirofilariasis has been studied more extensively. In this article we review the current prevalence of canine and feline cardiopulmonary dirofilariasis in the European continent, the transmission vectors, the current changes in the distribution and the possible causes, though the analysis of the epidemiological studies carried out until 2001 and between 2002 and 2011. The highest prevalences have been observed in the southern European countries, which are considered historically endemic/hyperendemic countries. Studies carried out in the last 10 years suggest an expansion of cardiopulmonary dirofilariasis in dogs toward central and northern Europe. Several factors can exert an influence on the spreading of the disease, such as movement of infected animals, the introduction of new species of mosquitoes able to act as vectors, the climate change caused by the global warming, and development of human activity in new areas. Veterinary controls to prevent the spreading of this disease, programs of control of vectors, and adequate protocols of prevention of dirofilariasis in the susceptible species should be carried out
Semen characteristics, sexual hormones and libido of hy-plus rabbit bucks influenced by a dietary multi-enzyme additive
A total of 144 adult Hy-Plus rabbit bucks were randomly assigned into 4 treatments of 36 replicates each, in a completely randomised design. Animals were fed ad libitum on a basal diet supplemented with a multi-enzyme complex (EZ, including cellulases, xylanases, protease and α-amylase) at 0 (EZ0), 1 (EZ1), 3 (EZ3) and 5 (EZ5) kg/ton of feed. Total sperm count was higher (P<0.05) in EZ5 than in EZ0. Sperm motility increased with increasing levels of the EZ additive, being lowest for EZ0 and highest for EZ5 rabbits (P<0.05). Percentage of dead sperm was higher (P<0.05) in EZ0 than in EZ5 rabbits. Rabbit bucks that received the highest level of EZ in their diet had the shortest reaction time (22.31±3.17 s; P<0.05), whereas EZ5 bucks took 43.56±5.89 s to mount does for the first time after exposure. Blood testosterone, 17α-estradiol and progesterone levels were highest in EZ5 rabbits and lowest in EZ0 rabbits. Enzyme addition increased (P<0.05) sperm transit in estrus doe cervical mucus. Data suggested that the EZ additive in diets of adult Hy-Plus rabbit bucks was effective to improve both semen characteristics and sexual drive
Modelo de Uso óptimo del territorio en el PRDU: Región de La Araucanía
The Regional Urban Development Plan (UDRP) for the Araucanía Region was prepared
using methods taken from ecology-based physical planning and from the integrated
analysis of natural systems. In this way, a series of processes for aggregation, extraction,
map algebra and logic operators was produced, making the best use of the analytical potential
of ArcView(c) and its Spatial Analyst extension, in order to develop a GIS model to
determine the optimum multi-purpose use of the territory, which was the basis used for
the proposed zoning of this regional planning instrumentPeer Reviewe
Effect of climate and insemination technique on reproductive performance of gilts and sows in a subtropical zone of Mexico
The objective of this study was to analyse the reproductive performance of hybrid (Yorkshire x Landrace) gilts/sows in relation to temperature-humidity index (THI) at artificial insemination (AI), season of AI, occurrence of estrus >8 d post-weaning, repeated estrus, insemination technique (cervical, CAI or post-cervical, PCAI) and parity. Data included 8851 reproductive records (1771 for gilts and 7080 for sows) from a pig farm in a sub-tropical zone (THI ranged from 72.9 in January to 81.8 in June). A decrease in pregnancy rate (PR, 89.8 vs 93.0%; P<0.01) and a tendency to decline farrowing rate (FR, 87.9 vs 90.3%; P=0.07) following AI during high THI (>82), compared to AI at <74 THI were observed. The spring and summer season were associated with decreased (P<0.01) PR compared with fall and winter (90.0% vs 93.0%). Likewise, FR decreased in spring and summer compared to fall and winter (88.5% vs. 90.9%). FR was higher (P<0.01) in non-repeat breeders compared with that of repeat-breeders (90.3% vs 76.2%). Litter size increased (P<0.01) from 10.8 ± 3.2 to 11.1 ± 3.1 pigs when the interval from weaning to estrus was >8 d. The insemination technique did not affect PR and FR but the litter size decreased (P<0.05) from 11.3 ± 3.0 to 11.1 ± 2.9 pigs when PCAI was used compared to CAI. This study reaffirms the negative effects of the hot season on reproductive performance of gilts/sows, although thermal stress at AI did not cause foetal losses. Also, there is no advantage in using the PCAI as compared to the CAI in gilts/sows with high numbers of sperm cells per AI
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