169 research outputs found

    Vaccination control programs for multiple livestock host species: an age-stratified, seasonal transmission model for brucellosis control in endemic settings

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    Brucella melitensis causes production losses in ruminants and febrile disease in humans in Africa, Central Asia, the Middle East and elsewhere. Although traditionally understood to affect primarily sheep and goats, it is also the predominant Brucella species that affects cows in some endemic areas. Despite this, no licensed vaccine is available specifically for use against B. melitensis in cows. The mainstay of most control programs is vaccination of sheep and goats with a live vaccine, Rev-1. The aim of this study was to investigate how critical vaccination of cows might be, in order to control B. melitensis on a mixed sheep-and-cattle farm

    Systematic review of brucellosis in the Middle East: disease frequency in ruminants and humans and risk factors for human infection

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    This paper considers the problem of finding global states incoming to a specified global state in a Boolean network, which may be useful for pre-processing of finding a sequence of control actions for a Boolean network and for identifying the basin of attraction for a given attractor, We show that this problem is NP-hard in general along with related theoretical results, On the other hand, we present algorithms that are much faster than the naive exhaustive search-based algorithm. ©2007 IEEE.link_to_subscribed_fulltex

    Burkitt's lymphoma of the colon and bronchi: three case reports

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

    Knowledge, Attitudes, and Practices Associated with Brucellosis in Livestock Owners in Jordan

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    We evaluated livestock owners' knowledge, attitudes, and practices regarding brucellosis in Jordan. A questionnaire was administered and biological samples were examined to verify the serological status of animals. Seroprevalence estimates indicated that 18.1% (95% CI: 11–25.3) of cattle herds and 34.3% (95% CI: 28.4–40.4) of small ruminant flocks were seropositive. The results showed that 100% of the interviewed livestock keepers were aware of brucellosis: 87% indicated a high risk of infection if unpasteurized milk is consumed and 75% indicated a high risk if unpasteurized dairy products are consumed. Awareness of the risk of infection through direct contact with fetal membranes or via physical contact with infected livestock is considerably lower, 19% and 13%, respectively. These knowledge gaps manifest in a high frequency of high-risk practices such as assisting in animal parturition (62%), disposing aborted fetuses without protective gloves (71.2%) or masks (65%), and not boiling milk before preparation of dairy products (60%). When brucellosis is suspected, basic hygiene practices are often disregarded and suspect animals are freely traded. Public health education should be enhanced as the disease is likely to remain endemic in the ruminant reservoir as long as a suitable compensation program is not established and trust on available vaccines is regained

    Effect of zero tillage and different weeding methods on grain yield of durum wheat in semi-arid regions

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    Received: September 28th, 2020 ; Accepted: December 1st, 2020 ; Published: December 10th, 2020 ; Correspondence: [email protected] high grain yield of wheat is limited by the dominance of weeds, particularly wild oat. Therefore, to improve wheat yield under these conditions, a field experiment was carried out in Maru Agricultural Research Station, Jordan during 2015–2016 and 2016–2017 to investigate yield response of two wheat varieties (Triticum durum L.) to different tillage and weeding treatments. The experimental design used was a split-split arrangement in a randomized complete block design with three replicates. Two-tillage treatments (conventional vs. zero tillage) were applied to the main plot, two wheat varieties to sub-plot, and five weeding methods (hand weeding, broadleaf + narrow leaf herbicide, broadleaf herbicide, narrow leaf herbicide, and controls) as a sub-sub-plot. The variety ‘Umqais’ had higher plant height, biological, grain, and straw yield than the variety ‘Sham’. Hand weeding slightly increased grain yield compared with mixed herbicides (the 2,4-D plus Antelope Clodinatop- propagyl). Furthermore, mixed herbicides presented a higher grain yield than using either single herbicide. The interaction between tillage systems and weeding methods was significant in both years. The highest (P < 0.05) straw yield (5,990 kg ha-1 ) was obtained by hand weeding under conventional tillage in the first season while the highest grain yield (2,005 kg ha-1 ) was obtained by hand weeding under zero tillage in the second season. Under all weed control treatments, the variety ‘Umqais’ had higher biological, grain, and straw yields than the variety ‘Sham’ in the second season indicating that variety ‘Umqais’ performed better under dry conditions. Our results confirmed the superior of zero tillage for increasing the grain yield of the variety ‘Umqais’, and for increasing the biological and straw yields of the variety ‘Sham’ under semi-arid rainfed conditions of Jordan

    Recording advances for neural prosthetics

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    An important challenge for neural prosthetics research is to record from populations of neurons over long periods of time, ideally for the lifetime of the patient. Two new advances toward this goal are described, the use of local field potentials (LFPs) and autonomously positioned recording electrodes. LFPs are the composite extracellular potential field from several hundreds of neurons around the electrode tip. LFP recordings can be maintained for longer periods of time than single cell recordings. We find that similar information can be decoded from LFP and spike recordings, with better performance for state decodes with LFPs and, depending on the area, equivalent or slightly less than equivalent performance for signaling the direction of planned movements. Movable electrodes in microdrives can be adjusted in the tissue to optimize recordings, but their movements must be automated to be a practical benefit to patients. We have developed automation algorithms and a meso-scale autonomous electrode testbed, and demonstrated that this system can autonomously isolate and maintain the recorded signal quality of single cells in the cortex of awake, behaving monkeys. These two advances show promise for developing very long term recording for neural prosthetic applications

    Low-Power Circuits for Brain–Machine Interfaces

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    This paper presents work on ultra-low-power circuits for brain–machine interfaces with applications for paralysis prosthetics, stroke, Parkinson’s disease, epilepsy, prosthetics for the blind, and experimental neuroscience systems. The circuits include a micropower neural amplifier with adaptive power biasing for use in multi-electrode arrays; an analog linear decoding and learning architecture for data compression; low-power radio-frequency (RF) impedance-modulation circuits for data telemetry that minimize power consumption of implanted systems in the body; a wireless link for efficient power transfer; mixed-signal system integration for efficiency, robustness, and programmability; and circuits for wireless stimulation of neurons with power-conserving sleep modes and awake modes. Experimental results from chips that have stimulated and recorded from neurons in the zebra finch brain and results from RF power-link, RF data-link, electrode- recording and electrode-stimulating systems are presented. Simulations of analog learning circuits that have successfully decoded prerecorded neural signals from a monkey brain are also presented

    Control of Brucella melitensis in endemic settings: a simulation study in the Nile Delta, Egypt

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    Small ruminant brucellosis remains endemic in many low and middle‐income countries (LMICs), where it poses a major economic and public health burden. Lack of resources to support long‐term vaccination, inherent characteristics of small ruminant production systems such as mixing of different flocks for grazing and limitations of the vaccines currently available, which can induce abortion in pregnant animals, have all hindered the effectiveness of control programs. In the current study, the likely effect of different control scenarios on the seroprevalence of brucellosis among the small ruminant population in a hypothetical area of an endemic region was simulated using compartmental models. The model accounts for variability in transmission rates between villages and also simulates control scenarios that target villages with high seroprevalence. Our results show that vaccination of young replacement animals only can effectively reduce the prevalence of small ruminant brucellosis in endemic settings if a high vaccination coverage is achieved. On the other hand, test and slaughter alone is not a promising strategy for control of small ruminant brucellosis under husbandry practices typical of endemic low‐resources settings. Furthermore, results show the potential success of some strategies requiring a relatively low overall vaccination coverage such as the vaccination of 50% of young replacements and 25% of adult animals each year. Control strategies selectively targeting high initial seroprevalence villages (p>10%) did not decrease the overall seroprevalence to acceptable levels in most of the examined scenarios. Scenario analysis showed that the efficacy of the simulated control strategies can be improved mostly by decreasing the proportion of between‐village trade and also by improving the performance of the used serological tests and increasing vaccine efficacy
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