Options for improving water use efficiency under worsening scarcity: Evidence from the Middle Olifants Sub-Basin in South Africa

Following the political changes in the early 1990s, the South African government introduced a comprehensive reform process for the water sector with the goal of achieving an enhanced and more equitable water management system. This paper analyses the existing water allocation situations and applies a non-linear optimisation model to investigate the optimal intraand inter-regional allocation regimes in the Middle Olifants sub-basin of South Africa. Economic issues such as efficiency gains related to water transfers are discussed and calculated water price elasticities and estimated water demand functions provide necessary fundamentals for further modelling work. Social and environmental aspects are accounted for by including constant water demands in the model. Results show higher benefits from inter-regional water allocation. Reducing water supply levels to conform to the sustainable water supply policy, it can be shown that although water supply is reduced by approximately 50%, total benefits from water use are only reduced by 5% and 11% for inter- and intra-regional allocation regimes, respectively. These results indicate that alternative water allocation mechanisms can serve as policy instruments to offset the effects of water scarcity

Human myiasis in an endemic area of Southwestern Ethiopia: Prevalence, knowledge, perceptions and practices

Background: Human subcutaneous myiasis is an endemic, understudied disease in Ethiopia. Objective: The aim of this study was to assess knowledge, perceptions and practices in different urban and rural communities of Jimma Zone, southwestern Ethiopia, related to human myiasis. Method: A cross-sectional, descriptive, comparative study was carried out during March -June 2005 in 5 urban and 3 rural kebeles in Jimma Zone. Kebeles were chosen by random sampling and a total of 1,272 households were selected by systematic random sampling technique for interview. Results: Most subjects (60.0%) mentioned lying on damp soil as the cause of myiasis. More urban than rural communities who wore un-ironed clothes had myiais infestation (p< 0.05). Myiasis was reported to be common in the lower extremities (65.6%), upper extremities (56.7%), abdomen (48.9%) and back (34.9%). A total of 86% dwellers responded that myiasis was more common during the wet season. More than half of the interviewees were knowledgeable about the clinical presentation of the disease. The most common signs and symptoms were itching (94.0%), pus discharge (82.9 %) and papules (79.5%). The majority (87.9%) of the study subjects treated infestations with hot matches. Wearing dry clothes (38.6%) was reported to be effective preventive measure. Nearly 64.8% of the rural and 68.7% of the urban communities knew that human subcutaneous myiasis is preventable. Conclusion: Due to the low levels of knowledge about myiasis, we recommend that community health education programs be developed through the health services to raise the awareness levels about this infestation to the general population.The Ethiopian Journal of Health Development Vol. 21 (2) 2007: pp. 166-17

Constraints on Mars Aphelion Cloud Belt Phase Function and Ice Crystal Geometries

This study constrains the lower bound of the scattering phase function of Martian water ice clouds (WICs) through the implementation of a new observation aboard the Mars Science Laboratory (MSL). The Phase Function Sky Survey (PFSS) was a multiple pointing all-sky observation taken with the navigation cameras (Navcam) aboard MSL. The PFSS was executed 35 times during the Aphelion Cloud Belt (ACB) season of Mars Year 34 over a solar longitude range of L_s=61.4{\deg}-156.5{\deg}. Twenty observations occurred in the morning hours between 06:00 and 09:30 LTST, and 15 runs occurred in the evening hours between 14:30 and 18:00 LTST, with an operationally required 2.5 hour gap on either side of local noon due the sun being located near zenith. The resultant WIC phase function was derived over an observed scattering angle range of 18.3{\deg} to 152.61{\deg}, normalized, and compared with 9 modeled phase functions: seven ice crystal habits and two Martian WIC phase functions currently being implemented in models. Through statistical chi-squared probability tests, the five most probable ice crystal geometries observed in the ACB WICs were aggregates, hexagonal solid columns, hollow columns, plates, and bullet rosettes with p-values greater than or equal to 0.60, 0.57,0.56,0.56, and 0.55, respectively. Droxtals and spheres had p-values of 0.35, and 0.2, making them less probable components of Martian WICs, but still statistically possible ones. Having a better understanding of the ice crystal habit and phase function of Martian water ice clouds directly benefits Martian climate models which currently assume spherical and cylindrical particles.Comment: Accepted Manuscript by Planetary and Space Scienc

Beliefs as Self-Sustaining Networks: Drawing Parallels Between Networks of Ecosystems and Adults’ Predictions

In this paper, we argue that beliefs share common properties with the self-sustaining networks of complex systems. Matching experiences are said to couple with each other into a mutually reinforcing network. The goal of the current paper is to spell out and develop these ideas, using our understanding of ecosystems as a guide. In Part 1 of the paper, we provide theoretical considerations relevant to this new conceptualization of beliefs, including the theoretical overlap between energy and meaning. In Part 2, we discuss the implications of this new conceptualization on our understanding of belief emergence and belief change. Finally, in Part 3, we provide an analytical mapping between beliefs and the self-sustaining networks of ecosystems, namely by applying to behavioral data a measure developed for ecosystem networks. Specifically, average accuracies were subjected to analyses of uncertainty (H) and average mutual information (AMI). The ratio between these two values yields degree of order, a measure of how organized the self-sustained network is. Degree of order was tracked over time and compared to the amount of explained variance returned by a categorical nonlinear principal components analysis (CATPCA). Finding high correspondence between the two measures of order, together with the theoretical groundwork discussed in Parts 1 and 2, lends preliminary validity to our theory that beliefs have important similarities to the structural characteristics of self-sustaining networks

Continuous Sweep: an improved, binary quantifier

Quantification is a supervised machine learning task, focused on estimating the class prevalence of a dataset rather than labeling its individual observations. We introduce Continuous Sweep, a new parametric binary quantifier inspired by the well-performing Median Sweep. Median Sweep is currently one of the best binary quantifiers, but we have changed this quantifier on three points, namely 1) using parametric class distributions instead of empirical distributions, 2) optimizing decision boundaries instead of applying discrete decision rules, and 3) calculating the mean instead of the median. We derive analytic expressions for the bias and variance of Continuous Sweep under general model assumptions. This is one of the first theoretical contributions in the field of quantification learning. Moreover, these derivations enable us to find the optimal decision boundaries. Finally, our simulation study shows that Continuous Sweep outperforms Median Sweep in a wide range of situations

Bibliography on HIV/AIDS in Ethiopia and Ethiopians in the Diaspora: The 2006 Update

No Abstract. The Ethiopian Journal of Health Development Vol. 21 (1) 2007: pp. 70-9

Long-range correlations and patterns of recurrence in children and adults' attention to hierarchical displays

In order to make sense of a scene, a person must pay attention to several levels of nested order, ranging from the most differentiated details of the display to the integrated whole. In adults, research shows that the processes of integration and differentiation have the signature of self-organization. Does the same hold for children? The current study addresses this question with children between 6 and 9 years of age, using two tasks that require attention to hierarchical displays. A group of adults were tested as well, for control purposes. To get at the question of self-organization, reaction time data were submitted to a detrended fluctuation analysis and a recurrence quantification analysis. Hurst exponents shows a long-range correlations (1/f noise), and recurrence measures (percent determinism, maximum line, entropy, and trend), show a deterministic structure of variability being characteristic of self-organizing systems. Findings are discussed in terms of organism-environment coupling that gives rise to fluid attention to hierarchical displays

Minigap, Parity Effect and Persistent Currents in SNS Nanorings

We have evaluated a proximity-induced minigap in the density of states (DOS) of SNS junctions and SNS nanorings at an arbitrary concentration of non-magnetic impurities. We have demonstrated that an isotropic energy minigap in the electron spectrum opens up already at arbitrarily weak disorder, while angle resolved DOS at higher energies can remain strongly anisotropic. The minigap value $\epsilon_g$ can be tuned by passing a supercurrent through an SNS junction or by applying a magnetic flux $\Phi$ to an SNS ring. A non-monotonous dependence of $\epsilon_g$ on $\Phi$ has been found at weak disorder. We have also studied persistent currents in isolated SNS nanorings. For odd number of electrons in the ring we have found a non-trivial current-phase (current-flux) relation which -- at relatively high disorder -- may lead to a $\pi$-junction state and spontaneous currents in the ground state of the system.Comment: 7 pages, 8 figure

Bibliography on HIV/AIDS in Ethiopia and Ethiopians in the Diaspora: The 2011 Update

No abstract