Sustainable development of smallholder crop-livestock farming in developing countries

Meeting the growing demand for animal-sourced food, prompted by population growth and increases in average per-capita income in low-income countries, is a major challenge. Yet, it also presents significant potential for agricultural growth, economic development, and reduction of poverty in rural areas. The main constraints to livestock producers taking advantage of growing markets include; lack of forage and feed gaps, communal land tenure, limited access to land and water resources, weak institutions, poor infrastructure and environmental degradation. To improve rural livelihood and food security in smallholder crop-livestock farming systems, concurrent work is required to address issues regarding efficiency of production, risk within systems and development of whole value chain systems. This paper provides a review of several forage basedstudies in tropical and non-tropical dry areas of the developing countries. A central tenet of this paper is that forages have an essential role in agricultural productivity, environmental sustainability and livestock nutrition in smallholder mixed farming systems

Assessment of apparent effectiveness of chemical egg disinfectants for improved artificial hatching in oreochromis karongae (pisces: cichlidae)

Oreochromis karongae is one of the three key Tilapia species locally known as ‘Chambo’ which is endemic to Lake Malawi. The species is favored by consumers and due to high demand its catches have significantly declined over time. Aquaculture holds the potential to supplement catches as well as produce seed for restocking purposes. However, seed production of O.karongae in artificial hatcheries has registered little success due to high egg and fry mortalities. Therefore, a study was conducted to compare the apparent effectiveness of three chemical egg disinfectants in an attempt to improve hatching success and reduce fry mortality in O. karongae in an artificial re-circulating incubation system at the National Aquaculture Center, Domasi, Malawi. Batches of 200 stage II eggs were immersed for 5 minutes in 50ml solutions of (1) 50mg/l Potassium Permanganate, (2) 500mg/l Formalin, (3) 1000mg/l Sodium Chloride, (4) 5000mg/l Sodium Chloride, while treatment (5) was a control without any chemical treatment. Each treatment was replicated three times in 1.2 L plastic incubation jars with continuous water flow rate of 0.17 l/s operated at 10% daily water replacement. There was significantly low total mortality and high hatchability in treatments (1), (2) and (3) than (4) and (5) (p<0.05). The results provided evidence that pre-incubation egg treatment using chemicals has potential to significantly reduce mortalities and increase fry production in an artificial re-circulating incubation system. It is recommended, based on the findings that lower concentrations of sodium chloride, being a safer and less toxic chemical can be used for disinfecting O.karongae eggs. Future studies should focus on undertaking a toxicity test with various levels of the chemical disinfectants to identify optimum doses. This should be coupled with microbiological assays to validate the apparent effectiveness found in this study and identify the key microbial species that are responsible for mortalities during incubation of O.karongae eggs in a re-circulating system.Key words: Egg, disinfectants, incubation, recirculation, hatchability, egg treatment, mortality, Oreochromis karonga

Genetic diversity within the genus Cynotilapia and its phylogenetic position among Lake Malawi’s mbuna cichlids

Cynotilapia’s unicuspid teeth, a unique character used to delineate it from all other mbuna genera, leaves evolutionary biologists wondering which is the closest relative to this genus among mbuna cichlids. This genus has only two described species out of the 10-13 species/taxa, whereby theundescribed taxa are either known by their colouration or place where they occur. AFLP genetic marker was used to determine the phylogenetic position of Cynotilapia among the mbuna and also the genetic diversity within this genus. Nei’s genetic distance, frequency of polymorphic loci and averageheterozygosity were used to unravel the genetic diversity. The neighbour-joining (NJ) dendrogram revealed that the genus Maylandia is the closest relative to Cynotilapia. Genetic distances were higher among all pairs of undescribed taxa than between the two species (Cynotilapia afra vs. C. axelrodi). Frequency of polymorphic loci and average heterozygosity were also higher within undescribed taxa than in two species. These results, coupled with already known phenotypic differences among thesetaxa (including colour, a crucial factor in speciation through sexual selection), do provide a strong base to taxonomists who can formally describe these taxa as species. The uncovered genetic differentiationis very important for conservation of this endemic fish fauna

Data analysis strategies for the detection of gravitational waves in non-Gaussian noise

In order to analyze data produced by the kilometer-scale gravitational wave detectors that will begin operation early next century, one needs to develop robust statistical tools capable of extracting weak signals from the detector noise. This noise will likely have non-stationary and non-Gaussian components. To facilitate the construction of robust detection techniques, I present a simple two-component noise model that consists of a background of Gaussian noise as well as stochastic noise bursts. The optimal detection statistic obtained for such a noise model incorporates a natural veto which suppresses spurious events that would be caused by the noise bursts. When two detectors are present, I show that the optimal statistic for the non-Gaussian noise model can be approximated by a simple coincidence detection strategy. For simulated detector noise containing noise bursts, I compare the operating characteristics of (i) a locally optimal detection statistic (which has nearly-optimal behavior for small signal amplitudes) for the non-Gaussian noise model, (ii) a standard coincidence-style detection strategy, and (iii) the optimal statistic for Gaussian noise.Comment: 5 pages RevTeX, 4 figure

Dirty Work, Clean Hands: The Moral Psychology of Indirect Agency

When powerful people cause harm, they often do so indirectly through other people. Are harmful actions carried out through others evaluated less negatively than harmful actions carried out directly? Four experiments examine the moral psychology of indirect agency. Experiments 1A, 1B, and 1C reveal effects of indirect agency under conditions favoring intuitive judgment, but not reflective judgment, using a joint/separate evaluation paradigm. Experiment 2A demonstrates that effects of indirect agency cannot be fully explained by perceived lack of foreknowledge or control on the part of the primary agent. Experiment 2B indicates that reflective moral judgment is sensitive to indirect agency, but only to the extent that indirectness signals reduced foreknowledge and/or control. Experiment 3 indicates that effects of indirect agency result from a failure to automatically consider the potentially dubious motives of agents who cause harm indirectly. Experiment 4 demonstrates an effect of indirect agency on purchase intentions.Psycholog

Application of the Gaussian mixture model in pulsar astronomy -- pulsar classification and candidates ranking for {\it Fermi} 2FGL catalog

Machine learning, algorithms to extract empirical knowledge from data, can be used to classify data, which is one of the most common tasks in observational astronomy. In this paper, we focus on Bayesian data classification algorithms using the Gaussian mixture model and show two applications in pulsar astronomy. After reviewing the Gaussian mixture model and the related Expectation-Maximization algorithm, we present a data classification method using the Neyman-Pearson test. To demonstrate the method, we apply the algorithm to two classification problems. Firstly, it is applied to the well known period-period derivative diagram, where we find that the pulsar distribution can be modeled with six Gaussian clusters, with two clusters for millisecond pulsars (recycled pulsars) and the rest for normal pulsars. From this distribution, we derive an empirical definition for millisecond pulsars as $\frac{\dot{P}}{10^{-17}} \leq3.23(\frac{P}{100 \textrm{ms}})^{-2.34}$. The two millisecond pulsar clusters may have different evolutionary origins, since the companion stars to these pulsars in the two clusters show different chemical composition. Four clusters are found for normal pulsars. Possible implications for these clusters are also discussed. Our second example is to calculate the likelihood of unidentified \textit{Fermi} point sources being pulsars and rank them accordingly. In the ranked point source list, the top 5% sources contain 50% known pulsars, the top 50% contain 99% known pulsars, and no known active galaxy (the other major population) appears in the top 6%. Such a ranked list can be used to help the future follow-up observations for finding pulsars in unidentified \textit{Fermi} point sources.Comment: 9 pages, 4 figures, accepted by MNRA

Towards Conservation Agriculture systems in Moldova

As the world population and food production demands rise, keeping agricultural soils and landscapes healthy and productive are of paramount importance to sustaining local and global food security and the flow of ecosystem services to society. The global population, expected to reach 9.7 billion people by 2050, will put additional pressure on the available land area and resources for agricultural production. Sustainable production intensification for food security is a major challenge to both industrialized and developing countries. The paper focuses on the results from long-term multi-factorial experiments involving tillage practices, crop rotations and fertilization to study the interactions amongst the treatments in the context of sustainable production intensification. The paper discusses the results in relation to reported performance of crops and soil quality in Conservation Agriculture systems that are based on no or minimum soil disturbance (no-till seeding and weeding), maintenance of soil mulch cover with crop biomass and cover crops, and diversified cropping systems involving annuals and perennials. Conservation Agriculture also emphasizes the necessity of an agro-ecosystems approach to the management of agricultural land for sustainable production intensification, as well as to the site-specificity of agricultural production. Arguments in favor of avoiding the use of soil tillage are discussed together with agro-ecological principles for sustainable intensification of agriculture. More interdisciplinary systems research is required to support the transformation of agriculture from the conventional tillage agriculture to a more sustainable agriculture based on the principles and practices of Conservation Agriculture, along with other complementary practices of integrated crop, nutrient, water, pest, energy and farm power management

Development of an international data repository and research resource: the Prospective studies of Acute Child Trauma and Recovery (PACT/R) Data Archive

Background: Studies that identify children after acute trauma and prospectively track risk/protective factors and trauma responses over time are resource-intensive; small sample sizes often limit power and generalizability. The Prospective studies of Acute Child Trauma and Recovery (PACT/R) Data Archive was created to facilitate more robust integrative cross-study data analyses. Objectives: To (a) describe creation of this research resource, including harmonization of key variables; (b) describe key study- and participant-level variables; and (c) examine retention to follow-up across studies. Methods: For the first 30 studies in the Archive, we described study-level (design factors, retention rates) and participant-level (demographic, event, traumatic stress) variables. We used Chi square or ANOVA to examine study- and participant-level variables potentially associated with retention. Results: These 30 prospective studies (N per study = 50 to 568; overall N = 5499) conducted by 15 research teams in 5 countries enrolled children exposed to injury (46%), disaster (24%), violence (13%), traffic accidents (10%), or other acute events. Participants were school-age or adolescent (97%), 60% were male, and approximately half were of minority ethnicity. Using harmonized data from 22 measures, 24% reported significant traumatic stress ≥1 month post-event. Other commonly assessed outcomes included depression (19 studies), internalizing/externalizing symptoms (19), and parent mental health (19). Studies involved 2 to 5 research assessments; 80% of participants were retained for ≥2 assessments. At the study level, greater retention was associated with more planned assessments. At the participant level, adolescents, minority youth, and those of lower socioeconomic status had lower retention rates. Conclusion: This project demonstrates the feasibility and value of bringing together traumatic stress research data and making it available for re-use. As an ongoing research resource, the Archive can promote ‘FAIR’ data practices and facilitate integrated analyses to advance understanding of child traumatic stress

Medicinal Plant Use and Health Sovereignty: Findings from the Tajik and Afghan Pamirs

Medicinal plants are indicators of indigenous knowledge in the context of political volatility and sociocultural and ecological change in the Pamir Mountains of Afghanistan and Tajikistan. Medicinal plants are the primary health care option in this region of Central Asia. The main objective of this paper is to demonstrate that medicinal plants contribute to health security and sovereignty in a time of instability. We illustrate the nutritional as well as medicinal significance of plants in the daily lives of villagers. Based on over a decade and half of research related to resilience and livelihood security, we present plant uses in the context of mountain communities. Villagers identified over 58 cultivated and noncultivated plants and described 310 distinct uses within 63 categories of treatment and prevention. Presence of knowledge about medicinal plants is directly connected to their use

An excess power statistic for detection of burst sources of gravitational radiation

We examine the properties of an excess power method to detect gravitational waves in interferometric detector data. This method is designed to detect short-duration (< 0.5 s) burst signals of unknown waveform, such as those from supernovae or black hole mergers. If only the bursts' duration and frequency band are known, the method is an optimal detection strategy in both Bayesian and frequentist senses. It consists of summing the data power over the known time interval and frequency band of the burst. If the detector noise is stationary and Gaussian, this sum is distributed as a chi-squared (non-central chi-squared) deviate in the absence (presence) of a signal. One can use these distributions to compute frequentist detection thresholds for the measured power. We derive the method from Bayesian analyses and show how to compute Bayesian thresholds. More generically, when only upper and/or lower bounds on the bursts duration and frequency band are known, one must search for excess power in all concordant durations and bands. Two search schemes are presented and their computational efficiencies are compared. We find that given reasonable constraints on the effective duration and bandwidth of signals, the excess power search can be performed on a single workstation. Furthermore, the method can be almost as efficient as matched filtering when a large template bank is required. Finally, we derive generalizations of the method to a network of several interferometers under the assumption of Gaussian noise.Comment: 22 pages, 6 figure