1,083 research outputs found
Animal health and welfare in organic livestock production in Europe– current state and future challenges
Existing data on animal health and welfare in organic livestock production systems in the European Community countries are reviewed in the light of the demands and challenges of the recently implemented EU regulation on organic livestock production. The main conclusions and recommendations of a three-year networking project on organic livestock production are summarised and the future challenges to organic livestock production in terms of welfare and health management are discussed. The authors conclude that, whilst the available data are limited and the implementation of the EC regulation is relatively recent, there is little evidence to suggest that organic livestock management causes major threats to animal health and welfare in comparison with conventional systems. There are, however, some well-identified areas, like parasite control and balanced ration formulation, where efforts are needed to find solutions that meet with organic standard requirements and guarantee high levels of health and welfare. It is suggested that, whilst organic standards offer an implicit framework for animal health and welfare management, there is a need to solve apparent conflicts between the organic farming objectives in regard to environment, public health, farmer income and animal health and welfare. The key challenges for the future of organic livestock production in Europe are related to the feasibility of implementing improved husbandry inputs and the development of evidence-based decision support systems for health and feeding management.
(HOVI, M., A. SUNDRUM and S. M. THAMSBORG (2003): Animal health and welfare in organic livestock production in Europe – current state and future challenges. Livestock production science 80, 41-53.
Modification and simulation of asphalt blowing unit (ABU) - hot oil system
This work focuses on the modification and simulation of asphalt blowing unit- hot oil system of Kaduna Refining and Petrochemical Company (KRPC). The modification involves an introduction of a 10-inch bye-pass line to the hot oil drum which helps in preventing oil loss and decrease heater duty for better efficiency and cost effective system. While the original and modified units were simulated using ASPEN HYSYS withthe aim of observing the effect of temperature on the heater duty of the units and to determine the volume of hot oil lost from the hot oil drum due to flashing. After successful completion of the simulation, the amount of vapour lost per hour for the operational system was found to be 0.3853 m3, with a heater duty of 32240 kcal/hr while for the modified system is 0.3841 m3 and 11480 kcal/hr for amount of vapour loss and heater duty respectively. Prior to the modification, the oil is replenished at an interval of 48hrs which is totally avoidable. The introduction of bye-pass line helps to prevent oil loss and reduce heater duty by 64.40%
Hierarchical Organization in Complex Networks
Many real networks in nature and society share two generic properties: they
are scale-free and they display a high degree of clustering. We show that these
two features are the consequence of a hierarchical organization, implying that
small groups of nodes organize in a hierarchical manner into increasingly large
groups, while maintaining a scale-free topology. In hierarchical networks the
degree of clustering characterizing the different groups follows a strict
scaling law, which can be used to identify the presence of a hierarchical
organization in real networks. We find that several real networks, such as the
World Wide Web, actor network, the Internet at the domain level and the
semantic web obey this scaling law, indicating that hierarchy is a fundamental
characteristic of many complex systems
A marked point process model with strong prior shape information for extraction of multiple, arbitrarily-shaped objects
We define a method for incorporating strong prior shape information into a recently extended Markov point process model for the extraction of arbitrarily-shaped objects from images. To estimate the optimal configuration of objects, the process is sampled using a Markov chain based on a stochastic birth-and-death process defined in a space of multiple objects. The single objects considered are defined by both the image data and the prior information in a way that controls the computational complexity of the estimation problem. The method is tested via experiments on a very high resolution aerial image of a scene composed of tree crowns
Ionizing radiation absorption of vascular surgeons during endovascular procedures
ObjectiveEndovascular procedures have become an integral part of a vascular surgeon’s practice. The exposure of surgeons to ionizing radiation and other safety issues have not been well studied. We investigated the radiation exposure of a team of vascular surgeons in an active endovascular unit and compared yearly dosages absorbed by various body parts among different surgeons. Patients’ radiation exposure was also assessed.MethodsThe radiation absorption of a team of vascular surgeons was prospectively monitored in a 12-month period. During each endovascular procedure, the effective body, eye, and hand radiation doses of all participating surgeons were measured by mini-thermoluminescent dosimeters (TLD) attached at the chest level under a lead apron, at the forehead at eye level, and at the hand. The type of procedure, fluoroscopy machine, fluoroscopy time, and personal and operating theatre radiation protection devices used in each procedure were also recorded. One TLD was attached to the patient’s body near the operative site to measure the patient’s dose. The yearly effective body, eye, and hand dose were compared with the safety limits of radiation for occupational exposure recommended by the International Commission on Radiation Protection (ICRP). The radiation absorption of various body parts per minute of fluoroscopy was compared among different surgeons.ResultsA total of 149 consecutive endovascular procedures were performed, including 30 endovascular aortic repairs (EVAR), 58 arteriograms with and without embolization (AGM), and 61 percutaneous transluminal angioplasty and stent (PTA/S) procedures. The cumulative fluoroscopy time was 1132 minutes. The median yearly effective body, eye, and hand dose for the surgeons were 0.20 mSv (range, 0.13 to 0.27 mSv), 0.19 mSv (range, 0.10 to 0.33 mSv) and 0.99 mSv (0.29 to 1.84 mSv) respectively, which were well below the safety limits of the ICRP. The mean body, eye, and hand dose of the chief surgeon per procedure were highest for EVAR. A significant discrepancy was observed for the average hand dose per minute of fluoroscopy among different surgeons. The mean radiation absorption of patients who underwent EVAR, AGM, and PTA/S was 12.7 mSv, 13.6 mSv, and 3.4 mSv, respectively.ConclusionWith current radiation protection practice, the radiation absorbed by vascular surgeons with a high endovascular workload did not exceed the safety limits recommended by ICRP. Variations in practice, however, can result in significant discrepancy of radiation absorption between surgeons
Excitation functions of 3He-particle-induced nuclear reactions on 103Rh: Experimental and theoretical investigations
Excitation functions for the 3He-induced reactions on 103Rh as alternative pathway for the production of the medically used 103Pd were studied by the stacked foil technique. Excitation functions of the 103Rh(3α, x) 103Pd, 103,104,104m,105Ag and 100,101,101m,102,102mRh reactions were determined up to 27 MeV by detecting only the characteristic γ-rays obtained from the decay of residual nuclei. The experimental results were compared with the theoretical ones obtained from the EMPIRE-3.2 code and the TENDL nuclear data library. From the measured cross-section data integral production yields were calculated
Production of Medical Radioisotopes with High Specific Activity in Photonuclear Reactions with Beams of High Intensity and Large Brilliance
We study the production of radioisotopes for nuclear medicine in
photonuclear reactions or ()
photoexcitation reactions with high flux [()/s], small
diameter m and small band width () beams produced by Compton back-scattering of laser
light from relativistic brilliant electron beams. We compare them to (ion,np) reactions with (ion=p,d,) from particle accelerators like
cyclotrons and (n,) or (n,f) reactions from nuclear reactors. For
photonuclear reactions with a narrow beam the energy deposition in the
target can be managed by using a stack of thin target foils or wires, hence
avoiding direct stopping of the Compton and pair electrons (positrons).
isomer production via specially selected cascades
allows to produce high specific activity in multiple excitations, where no
back-pumping of the isomer to the ground state occurs. We discuss in detail
many specific radioisotopes for diagnostics and therapy applications.
Photonuclear reactions with beams allow to produce certain
radioisotopes, e.g. Sc, Ti, Cu, Pd, Sn,
Er, Pt or Ac, with higher specific activity and/or
more economically than with classical methods. This will open the way for
completely new clinical applications of radioisotopes. For example Pt
could be used to verify the patient's response to chemotherapy with platinum
compounds before a complete treatment is performed. Also innovative isotopes
like Sc, Cu and Ac could be produced for the first time
in sufficient quantities for large-scale application in targeted radionuclide
therapy.Comment: submitted to Appl. Phys.
Dementia in late-onset epilepsy: The Atherosclerosis Risk in Communities study
OBJECTIVE: To determine the risk of dementia after the development of late-onset epilepsy. METHODS: We used data from the Atherosclerosis Risk in Communities (ARIC) cohort study, which started in 1987 to 1989 with 15,792 mostly Black and White men and women from 4 US communities. We identified late-onset epilepsy (LOE; seizures starting at age 67 or later) from linked Medicare claims data. We used a Cox proportional hazards regression model to evaluate associations between LOE and dementia through 2017 as ascertained from neuropsychological testing, interviews, and hospital discharge surveillance, and we used multinomial logistic regression to assess the risk of dementia and mild cognitive impairment in the subset with full neuropsychological assessments available. We adjusted for demographics and vascular and Alzheimer disease risk factors. RESULTS: Of 9,033 ARIC participants with sufficient Medicare coverage data (4,980 [55.1%] female, 1993 [22.1%] Black), 671 met the definition of LOE. Two hundred seventy-nine (41.6%) participants with and 1,408 (16.8%) without LOE developed dementia (p < 0.001). After a diagnosis of LOE, the adjusted hazard ratio for developing subsequent dementia was 3.05 (95% confidence interval 2.65-3.51). The median time to dementia ascertainment after the onset of LOE was 3.66 years (quartile 1-3, 1.28-8.28 years). INTERPRETATION: The risk of incident dementia is substantially elevated in individuals with LOE. Further work is needed to explore causes for the increased risk of dementia in this growing population
MEMORY AND COGNITIVE ABILITIES IN UNIVERSITY PROFESSORS:
Professors from the University of California at Berkeley were administered a 90-min test battery of cognitive performance that included measures of reaction time, paired-associate learning, working memory, and prose recall. Age effects among the professors were observed on tests of reaction time, paired-associate memory, and some aspects of working memory. Age effects were not observed on measures of proactive interference and prose recall, though age-related declines are generally observed in standard groups of elderly individuals. The findings suggest that age-related decrements in certain cognitive functions may be mitigated in intelligent, cognitively active individualsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72229/1/j.1467-9280.1995.tb00510.x.pd
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