One- and two-atom states in a rotating ring lattice

We study the states of one and two atoms in a rotating ring lattice in a Hubbard type tight-binding model. The model is developed carefully from basic principles in order to properly identify the physical observables. The one-particle ground state may be degenerate and represent a finite flow velocity depending on the parity of the number of lattice sites, the sign of the tunneling matrix element, and the rotation speed of the lattice. Variation of the rotation speed may be used to control one-atom states, and leads to peculiar behaviors such as wildly different phase and group velocities for an atom. Adiabatic variation of the rotation speed of the lattice may also be used to control the state of a two-atom lattice dimer. For instance, at a suitably chosen rotation speed both atoms are confined to the same lattice site.Comment: Very close to the submitted versio

Progress and future prospects in groundnut improvement to feed Africa in the face of technological advancements

Crop productivity is crucial in meeting food demands to feed the growing population in the face of endemic biotic and abiotic stresses. Technological advancement and its application to boost crop productivity would be a pathway towards ensuring food and nutrition security. Dryland legumes including groundnut are suitable in diversification of farming systems as insurance crops to ensure productivity. Crop improvement is one of the pillars towards enhancing productivity by delivering products and services based on demand articulation such as high yielding resilient varieties that are nutrient dense to address the global nutrition agenda. Recent advancements in molecular technology has made it possible to sequence the groundnut genome, develop genetic maps and identification of quantitative trait loci (QTLs) for key traits of importance. These new developments need to be exploited to accelerate the design and development of quality products that fits within the African farming systems. The low genotyping cost has opened avenues for research centers in African countries to embrace the use of genomic selection tools in breeding. This should enhance efficiency in exploiting the wild genetic resource base, broadening the narrow genetic base of groundnut and fast tracking variety release. The use of molecular tools in breeding and wide hybridization techniques coupled with high throughput phenotyping is a new dawn to breeding programs and this would contribute significantly to food security and poverty alleviation in the long run. However, the success in the modernization of breeding for efficiency will be underpinned by pro-active engagement among different actors in the national, regional and international arena to leverage resources and expertise in the omics era for sustained outcomes. Healthy working partnerships are also key to the delivery and utilization of such technologies coupled with learning and feedback for product improvement

Quantitative methods for sampling of germplasm collections : getting the best out of molecular markers when creating core collections

This thesis addresses the issue of how special players (crisis entrepreneurs) try to generate attention to a latent crisis and how government communication can contribute to identifying and interpreting such a crisis. In chapter 1, I show how crisis communication is an activity that is often associated with organizations. This study takes a different view. It is based on the concept that strategic crisis communication is used by those in the immediate environment to achieve certain goals. In society, certain individuals and groups can decide to oppose and denounce a given crisis. Some of those involved often start signalling the risk of an impending crisis before any such crisis has actually developed. In this study, I refer to individuals who generate signals of this kind as ‘crisis entrepreneurs’. These crisis entrepreneurs typically take the initiative when it comes to airing their concerns about a potential crisis situation. However, such individuals often have to deal with certain interactional problems that make it difficult for them to raise the issue of a crisis. They have to deal with certain ‘interactional’ challenges, while running the risk that their signals will not be picked up. For instance, they can be held responsible for raising the problem in question. They can be accused of bearing some degree of personal responsibility for the problem, through negligence, incompetence, or laziness, for example. In this study, I have explored the way in which crisis entrepreneurs issue signals. This is an attempt to identify the problems that they encounter as they attempt to draw people’s attention to a given crisis. The goal of this study is to enhance our understanding of crisis entrepreneurs’ interactional problems. The study makes use of the ‘discursive perspective’, which is based on the discursive psychological approach developed in the 1990s by two British social psychologists, Derek Edwards and Jonathan Potter. To date, this interaction-based approach has seldom been used in the context of crisis communication. Chapter 2 underlines the value of examining the way in which stakeholders within an organization’s environment raise the issue of a crisis. In terms of crises as a phenomenon, it is important to do justice to the dynamics of risks and crises. In essence, this is about what happens in the course of interactions. In such an environment, it is vital for an organization to keep pace with those in its surroundings if it is to observe signals in interaction with this dynamic environment. This requires a view of crisis communication that allows sufficient scope for the interactional dimension. Chapter 3 explores various elements that characterize crises in general, while describing a particularly significant phase - the latent crisis. I have identified two forms of latent crisis, a lingering form and a creeping form. These two forms differ chiefly in terms of the dynamics involved. While the dynamics of both types exhibit both peaks and troughs, there are differences. Lingering crises are entirely lacking in dynamism for extended periods of time. The dynamics of creeping crises, on the other hand, tend to increase gradually. After describing the theoretical framework of the study, chapter 4 proceeds to explore the theoretical and methodological scope of discursive psychology, in terms of an interactional approach to crisis communication. Discursive psychology offers the valuable option of using discourse analysis to examine the social context of risks from the standpoint of everyday reality. A discursive perspective characteristically focuses on a) everyday interactions that are not shaped by the study itself and b) the transactions that, either consciously or unconsciously, feature in such interactions. The discursive perspective offers a specific form of discourse analysis that communications professionals can use to understand how those in the environment express their ideas relative to others. The significance of this is that it can help professionals to understand the specific interactional problems facing crisis entrepreneurs. These involve dealing with certain ‘interactional’ challenges, while running the risk that their signals will not be picked up. Chapter 5 discusses the two cases selected for this study. The selected case domain is education in the Netherlands. I have investigated the ways in which crisis entrepreneurs have signalled problems in this sector. I used discourse analysis (Edwards, 1997; Potter, 1992) to first examine the interactional efforts of those behind collective social movements, then those of individual whistleblowers. To this end, I studied an interview with Matthé Sjamaar, the rector of a secondary school, which was published in Onderwijsblad (education journal) in May 1998. I also examined the manifesto of Beter Onderwijs Nederland (better education for the Netherlands; BON), which was published in the NRC Handelsblad newspaper in June 2006. Both sources raised the issue of a crisis. One of the criteria that I used in selecting these texts was whether the crisis entrepreneur in question had the ability to influence the public debate. In both cases, both local and national media responded to the statements made by these crisis entrepreneurs. Using a discursive response analysis, I explored the way in which newspapers dealt with the interactional problems faced by these crisis entrepreneurs. Chapters 6 and 7 form the empirical part of this study. The analysis identified three important discursive activities that are carried out by crisis entrepreneurs. These are: 1. demonstrating the validity of the problem, 2. establishing the messenger’s credibility, and 3. creating the belief in a solution. The analysis showed that Matthé Sjamaar creates indirectly undetermined others in the environment as being partly responsible for the cause of the problem, while exhibiting a degree of fatalism and holding out no prospect of a solution. He makes an indefinite-side group responsible for the problems. He shows he can not control the problem because it is too large. He creates the crisis as an isolated entity. They are merely the facts which he shows, which are independent of him. He suggests that he has done a lot of hard work and now others have to do something. The media portrayed Rector Sjamaar as symbolizing a problem that was primarily a personal issue. BON, on the other hand, presents itself as a collective that is committed to achieving better education in the Netherlands. The writers display insight and overview of the education problem and create the association to BON as a group consisting of ‘outspoken thinkers’ who are not hindered by doubts. The authors set themselves superior in their attitude towards the education reformers. The writers poses the problem as clear and relevant to everyone and so they create their own need for existence. So now they start a movement and give voice to something that has long been going on: BON is the solution to turn the tide. We can jointly fate a twist. Various media sources reinforced this image, portraying this social movement as the solution to the problem. The study has shown that crisis entrepreneurs may differ in terms of the strategies used and the interactional problems encountered. The solutions put forward by BON have proved more effective than those suggested by Rector Sjamaar. As a result, the discursive activities pursued by the former have been more successful than those of the latter. The diverse reactions exhibited by the media sources in this study serve to underline the precarious nature of a crisis entrepreneur’s operation. For instance, the analysis shows that rather than focusing on the authenticity of his signal, the responses to Matthé Sjamaar’s article dismiss his views as a purely private emotion. Based on this study, I show that the Rector’s initiative was undermined by his presentation of the problem. It failed to trigger a general sense of crisis as a result of segregation. BON fared very differently, as the problem of educational reform is already widely recognized. Moreover, as the analysis shows, BON’s spokespersons are important actors in this connection. Ad and Marijke Verbrugge have put forward polarizing arguments, in which they distance themselves from the New Learning concept. These views have clearly been taken on board by supporters and opponents in the debate triggered by these authors. The study has also shown that certain interactional problems are not necessarily inevitable, but that such problems can be triggered by crisis entrepreneurs themselves. Its content is inextricably linked to people’s goals in making specific comments. Chapter 8 summarizes the main observations in this thesis. It shows that the problems created by raising the issue of a latent crisis are not purely substantive in nature (‘is this crisis genuine?’), there is also an interactional aspect (for example, ‘how do I get people to accept the urgency and validity of the problem?’). My study provides a greater understanding of the course that crises can take. It also shows that crisis entrepreneurs can be seen as dynamic elements within society. They express dissenting views, and launch new initiatives through various forms of traditional and electronic media. This process can be very instructive. Communications professionals can better understand how crises develop among those in their environment if they are aware of the types of interactional problems, and the types of responses, that can result from raising the issue of a crisis. Moreover, this might also help communications professionals to achieve better outcomes in their dealings with crisis entrepreneurs. A discursive approach is valuable in this respect because it shows how certain themes in communication can deal with policy development. This approach can lead to a better hold on these themes in practice and can provide another perspective to widespread failure of interaction between government and citizens. The government is often unable to understand what the citizen means, because their interactional problems are not recognized. Knowledge of their doubts on an issue, can help the organization to acquire a better understanding of objections – from inside and out – against a particular policy. A discourse analysis of the interactional contributions of crisis entrepreneurs may give a rich and structured insight into latent crisis supply, including the strategies, interactional problems and reactions of the actors involved and how they are able to recognize a potential crisis. </p

Evaluation of microbial quality of water in Kawempe Division, Kampala Surburb

Objective: The aim of the study was to evaluate the microbial quality of water in Kawempe Division, Kampala district.Design: A cross sectional study was conducted on two major water supplies used in the Kawempe division, Kampala district.Setting: Between June 2015 and April 2016, total coliforms and Escherichia coli (E. coli) were investigated in two major sources of water during wet and dry seasons. Water samples from tap water and protected spring wells were collected and analyzed for total coliforms and E. coli.Subjects: A total of 100 water samples were collected and analyzed for microbial quality. Plate count method was used. 10 ml of water sample was mixed with 90 ml of 1% peptone water saline. 1 ml of the inoculum was transferred to each of the two petri-dishes containing agar and mixed thoroughly. The solidified agar plates for total coliforms and E. coli were incubated at 370C and 44.5 respectively and read after 24-48 hours. The results were expressed as Colony Forming Units (CFU) per milliliter (mL).Results: Of the 100 samples analyzed, protected wells were more contaminated with E. coli (48%) and total coliforms (56%) than tap water with E.coli at (4%) and total coliforms (7%) respectively. Tap water had a significantly higher degree of mean microbial count of 362 CFU/mL (P&lt;0.05) while protected spring well had mean microbial count of 83 CFU/mL. The microbial counts ranged between 5.0 x 100 to 1.92 x 103 CFU/mL in the wet season and 5.0 x 100 to 6.4 x 102 CFU/mL in the dry season. Protected spring wells had a mean microbial count between 2.0 x 100 to 2.6 x 102 CFU/mL in the wet season and 2.0 x 100 to 2.6 x 102 CFU/mL in the dry season. There was a statistical significant difference between counts of total coliforms and E.coli in the wet season and dry season (P&lt;0.05).Conclusions: Tap water and protected spring wells in Kawempe Division, Kampala district are contaminated with total coliforms and E.coli. The presence of total Coliforms and E.coli in drinking water is of great public health significance and this may lead to the onset of various enteric diseases. Therefore, this calls for immediate response from health authority to enforce public health intervention measures in the area

Assessment of variability in on-farm trials : a Uganda case.

Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2002.On-farm trials techniques have become an integral part of research aimed at improving agricultural production especially in subsistence farming. The poor performance of certain technologies on the farmers' fields known to have performed well on stations have been of concern. Traditionally, on-farm trials are meant to address such discrepancies. The main problems associated with on-farm trials in most developing countries are high variability and inappropriate application of statistical knowledge known to work on station to on-farm situation. Characterisation of various on-farm variability and orientation of existing statistical methods may lead to improved agricultural research. Characterization of the various forms of variability in on-farm trials was conducted. Based on these forms of variability, estimation procedures and their strength have been assessed. Special analytical tools for handling non-replicated experiments known to be common to on-farm trials are presented. The above stated procedures have been illustrated through a review of Uganda case. To understand on-farm variability require grouping of sources of variability into agronomic, animal and socioeconomic components. This led to a deeper understanding of levels of variability and appropriate estimation procedures. The mixed model, modified stability analysis and additive main effects and multiplicative interaction methods have been found to play a role in on-farm trials. Proper approach to on-farm trials and application of appropriate statistical tools will lead to efficient results that will subsequently enhance agricultural production especially under subsistence farming.Rockefeller Foundation and Makerere University