289 research outputs found
Towards a more situation appropriate and responsive extension approach for Ethiopia
This paper investigates the influence of some selected personal, environmental and intervening factors on the adoption behaviour of dairy producers with the object of identifying the most important causes of behaviour and thus finding a more purposeful and effective way of changing the adoption behaviour.
200 farmers were randomly drawn form a total of about 430 standing members of Ada Liben Woreda Dairy And Dairy Products Marketing Association (ALWDADPMA) in Debrezeit, Ethiopia. In the analysis of data the ordinary least squares (OLS) regression methods were employed to identify the most important determinants associated with behavioural change
The results indicate that, in general, the intervening variables tend to have the highest prediction value. They were found to explain 68.3 percent and 80.9 percent of the variance of behaviour associated with the practice adoption and production efficiency, while the independent variables explained only 17.8 percent and 19.3 percent of the variation, respectively. The contribution of independent variables appears substantial only when their indirect effect (effect through intervening variables) is considered.
SA Jnl. Agric. Ext. Vol 33 2004: 52-6
Artificial intelligence for conflict management
Student Number : 0213053E
MSc research report -
School of Electrical and Information Engineering -
Faculty of Engineering and the Built EnvironmentOne of the risks that have a great impact on society is military con-
°ict. Militarised Interstate Dispute (MID) is de¯ned as an outcome of
interstate interactions which result in either peace or con°ict. E®ective
prediction of the possibility of con°ict between states is a good decision
support tool. Neural networks (NNs) have been implemented to predict
militarised interstate disputes before Marwala and Lagazio [2004]. Sup-
port Vector Machines (SVMs) have proven to be very good prediction
techniques in many other real world problems Chen and Odobez [2002];
Pires and Marwala [2004]. In this research we introduce SVMs to predict
MID. The results found show that SVM is better in predicting con°ict
cases (true positives) without e®ectively reducing the number of correctly
classiÂŻed peace (true negatives) than NN. A sensitivity analysis for the
in°uence of the dyadic (explanatory) variables shows that NN gives more
consistent and easy to interpret results than SVM. Further investigation
is required with regards to the sensitivity analysis of SVM
On the need for multi-dimensional models for the safety analysis of (fast-spectrum) Molten Salt Reactors
This paper aims at characterizing the impact of adopting numerical models with different dimensionalities on the predicted behavior of fast-spectrum Molten Salt Reactors (MSRs). The study encompasses 1-D, 2-D, and 3-D representations of thermal-hydraulics and precursor transport/diffusion, along with spatial and point kinetics models for neutronics. We evaluate the accuracy of each model based on steady-state results and on the reactor response to 2 different transient initiators. The findings emphasize the significance of utilizing a 3-D representation with accurate thermal-hydraulics modeling, and with either spatial kinetics or carefully calibrated point kinetics incorporating a spatial description of precursors transport. 2-D and 1-D models can reproduce main trends and remain valuable tools for e.g. reactor design, control-oriented studies or uncertainty quantification. However, proper calibration of these models is needed and the user should be aware that alterations in flow patterns could jeopardize model calibration and hide first-order local effects
Anti-colorectal cancer activity of an organometallic osmium arene azopyridine complex
This first in vivo antitumour activity for an organometallic osmium arene complex, [Os(eta(6)-p-cym)(4-(2-pyridylazo)-N,N-dimethylaniline)I]PF(6), is reported. The complex delays the growth of HCT116 human colon cancer xenografts in mice, with negligible toxicity. Its activity appears to involve redox mechanisms and its potency towards A2780 ovarian and A549 lung cancer cells is increased significantly in combination with L-buthionine-sulfoximine
Halide Control of N,N-Coordination versus N,C-Cyclometalation and Stereospecific Phenyl Ring Deuteration of Osmium(II) p-Cymene Phenylazobenzothiazole Complexes
YesWe report the synthesis of halido Os(II) p-cymene complexes bearing bidentate chelating phenylazobenzothiazole (AZBTZ) ligands. Unlike the analogous phenylazopyridine (AZPY) complexes, AZBTZ-NMe2 is capable of both N,N-coordination to Os(II) and cyclometalation to form N,C-coordinated species. N,C-Coordination occurs via an azo nitrogen and an ortho carbon on the aniline ring, as identified by 1H NMR and X-ray crystallography of [Os(p-cym)(N,N-AZBTZ-NMe2)Cl]PF6 (1a), [Os(p-cym)(N,N-AZBTZ-NMe2)Br]PF6 (2a), [Os(p-cym)(N,C-AZBTZ-NMe2)Br] (2b), and [Os(p-cym)(N,C-AZBTZ-NMe2)I] (3b). The N,C-coordinated species is more stable and is not readily converted to the N,N-coordinated complex. Analysis of the crystal structures suggests that their formation is influenced by steric interactions between the p-cym and AZBTZ-NMe2 ligands: in particular, larger monodentate halide ligands favor N,C-coordination. The complexes [Os(p-cym)(N,N-Me2-AZBTZ-NH2)Cl]PF6 (4) and [Os(p-cym)(N,N-Me2-AZBTZ-NH2)I]PF6 (5) were synthesized with methyl groups blocking the ortho positions on the aniline ring, forcing an N,N-coordination geometry. 1H NMR NOE experiments confirmed hindered rotation of the arene ligand and steric crowding around the metal center. Complex 2b exhibited unexpected behavior under acidic conditions, involving regiospecific deuteration of the aniline ring at the meta position, as observed by 1H NMR and high-resolution ESI-MS. Deuterium exchange occurs only under acidic conditions, suggesting an associative mechanism. The calculated partial charges on 2b show that the meta carbon is significantly more negatively charged, which may account for the regiospecificity of deuterium exchange.ERC, EPSRC, The Royal Societ
Different Coordination Modes of a Tripod Phosphine in Gold(I) and Silver(I) Complexes
The following gold(I) and silver(I) complexes of the tritertiary phosphine 1,1,1-
tris(diphenylphosphinomethyl)ethane, tripod , have been synthesised: Au3(tripod)X3
[X = Cl(1), Br(2), I(3)];
[Au3(tripod)2Cl2]Cl
(4); Au(tripod)X [X = Br(5), I(6)]; Ag3(tripod)
(NO3)4
(7), Ag(tripod)NO3
(8). They were
characterized by X-ray diffraction (complexes 2, 3 and 4), 31P
NMR spectroscopy, electrospray and FAB mass
spectrometry and infrared spectroscopy. Complexes 2 and 3 show a linear
coordination geometry for Au(I),
with relatively short Au-P bond distances. Complex 3 has a Au•••Au
intramolecular distance of 3.326
A
°
,
while complex 2 had a short Au•••Au intermolecular interaction of 3.048
A
°
. Complexes 4-6 were found by
31P NMR spectroscopy studies to contain a mixture of species in solution, one of which crystallised as
[Au3(tripod|)2Cl2]Cl which was shown by X-ray diffraction to contain both
tetrahedral and linear Au(I), the
first example of a Au(I) complex containing such a mixture of geometries. The reaction of [Au3
(tripod)Cl3] (1)
with tripod led successfully to the formation of [Au3(tripod|)2Cl2]+
and [Au3(tripod)2Cl3]+ and [Au3(tripod|)3Cl]2+.
The silver(I)
complexes, 7 and 8 appear to contain linear and tetrahedral Ag(I), respectively
Level of Care Preferences Among Nursing Home Residents With Advanced Dementia
Delivering goal-directed care is a hallmark of high-quality palliative care, but requires an understanding of preferences
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Patterns, Predictors, and Outcomes of Falls Trajectories in Older Adults: The MOBILIZE Boston Study with 5 Years of Follow-Up
Background: Falls may occur as unpredictable events or in patterns indicative of potentially modifiable risks and predictive of adverse outcomes. Knowing the patterns, risks, and outcomes of falls trajectories may help clinicians plan appropriate preventive measures. We hypothesized that clinically distinct trajectories of falls progression, baseline predictors and their coincident clinical outcomes could be identified. Methods: We studied 765 community-dwelling participants in the MOBILIZE Boston Study, who were aged 70 and older and followed prospectively for falls over 5 years. Baseline demographic and clinical data were collected by questionnaire and a comprehensive clinic examination. Falls, injuries, and hospitalizations were recorded prospectively on daily calendars. Group-Based Trajectory Modeling (GBTM) was used to identify trajectories. Results: We identified 4 distinct trajectories: No Falls (30.1%), Cluster Falls (46.1%), Increasing Falls (5.8%) and Chronic Recurring Falls (18.0%). Predictors of Cluster Falls were faster gait speed (OR 1.69 (95CI, 1.50–2.56)) and fall in the past year (OR 3.52 (95CI, 2.16–6.34)). Predictors of Increasing Falls were Diabetes Mellitus (OR 4.3 (95CI, 1.4–13.3)) and Cognitive Impairment (OR 2.82 (95CI, 1.34–5.82)). Predictors of Chronic Recurring Falls were multi-morbidity (OR 2.24 (95CI, 1.60–3.16)) and fall in the past year (OR 3.82 (95CI, 2.34–6.23)). Symptoms of depression were predictive of all falls trajectories. In the Chronic Recurring Falls trajectory group the incidence rate of Hospital visits was 121 (95% CI 63–169) per 1,000 person-years; Injurious falls 172 (95% CI 111–237) per 1,000 person-years and Fractures 41 (95% CI 9–78) per 1,000 person-years. Conclusions: Falls may occur in clusters over discrete intervals in time, or as chronically increasing or recurring events that have a relatively greater risk of adverse outcomes. Patients with multiple falls, multimorbidity, and depressive symptoms should be targeted for preventive measures
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