636 research outputs found
The establishment of a commercial fishery for Haplochromis in the Uganda waters of Lake Victoria
Lake Victoria, straddling the Equator, is the second largest lake in the world, with a surface area of approximately 26,000 square miles (41,500 square kilometers) and a maximum depth of about 300 feet. Uganda possesses most of the north end of the lake which consists of a long, indented coastline and a chain of offshore islands on the edge of a 'continental shelf' separating relatively shallow sheltered inshore waters from the deeper open waters of the lake.
At the present time the lake is harvested mainly by a native gill net fishery confined almost entirely to the shallow sheltered inshore waters. The annual production of all species from Uganda waters is in the region of 24,000 tons per annum, and Tilapia(Cichlidae)is commercially the most important genus. Haplochromis, a close relative of Tilapia, but generally much smaller, contributes only a small amount to this annual production; see Table 1, although they are probably the most abundant group of fish present in the lake.
Through international aid programmes Uganda has been offered a canning plant and it is thought that Haplochromis is the most suitable type of fish to be utilized by such a plant. The Uganda Fisheries Department are conducting research into processing techniques and marketing and the East African Freshwater Fisheries Research Organization was asked to conduct a survey of the Haplochromis stocks of the lake with a view to estimating the ability or otherwise of these stocks to support a commercial canning industry
Fishing gear development 1965-67
The commercial fisheries of lake Victoria are based principally on a number of species of tilapia althougy considerable tonnages of other genera are landed,namely clarias Bagrud,photopteru
Experimental trawling operations on Lake Victoria
A programme has been started to investigate the feasibility of operating a trawl fishery for Haplochromis in connection with development of a proposed cannery by the Ugandan government Because of lack of gear much time has been spent on the development of boats and nets for this type of fishing
Understanding the shared meaning of recovery from Substance Use Disorders.:New findings from the What is Recovery? Study.
Background:Substance use disorder (SUD) resolution typically involves a long-term, comprehensive process of change now widely referred to as “recovery.” Yet, definitions of recovery vary substantially, producing significant confusion. To support formal recovery definitions, we aimed to systematically identify recovery elements that are central to those in recovery and shared regardless of subgroup/pathway.Methods:Data were from the What is Recovery? Study, involving a diverse, national, online survey of people in recovery (N = 9341). Surveys included a 35-item recovery measure reflecting 4 domains; participants reported whether or not each element definitely belonged in their recovery definitions. Analyses examined item endorsements overall and among 30 subgroups defined a priori (by sociodemographics, substance use characteristics, and help-seeking history) to determine where items met study-specific centrality thresholds (ie, endorsement by ⩾80% and top-10 ranking, by endorsement level). We then classified items as “core” if meeting centrality thresholds both overall and for all 30 subgroups, and “prevalent” if meeting centrality thresholds overall and for 26 to 29 subgroups.Results:Four “core” recovery elements emerged, including a process of growth or development; being honest with oneself; taking responsibility for the things one can change; and reacting in a more balanced way. Four “prevalent” recovery elements also emerged, referencing the ability to enjoy life and handle negative feelings without substance use; abstinence and/or nonproblematic substance use; and living a life that contributes. Subgroups differing most in their endorsements included those reporting mild/moderate SUD severity; non-abstinent recovery; and no specialty treatment or mutual-help group attendance.Conclusions:Recovery elements identified here partially reflect some stakeholder definitions, but offer greater specificity and include novel elements (eg, personal integrity). Elements may point to areas of functioning that are damaged in the addiction process and can support an addiction-free life. Findings should inform institutional recovery definitions; SUD services and research; and communications about recovery
Faster linearizability checking via -compositionality
Linearizability is a well-established consistency and correctness criterion
for concurrent data types. An important feature of linearizability is Herlihy
and Wing's locality principle, which says that a concurrent system is
linearizable if and only if all of its constituent parts (so-called objects)
are linearizable. This paper presents -compositionality, which generalizes
the idea behind the locality principle to operations on the same concurrent
data type. We implement -compositionality in a novel linearizability
checker. Our experiments with over nine implementations of concurrent sets,
including Intel's TBB library, show that our linearizability checker is one
order of magnitude faster and/or more space efficient than the state-of-the-art
algorithm.Comment: 15 pages, 2 figure
The long‐term effectiveness and cost‐effectiveness of public health interventions; how can we model behavior? A review
The effectiveness and cost of a public health intervention is dependent on complex human behaviors, yet health economic models typically make simplified assumptions about behavior, based on little theory or evidence. This paper reviews existing methods across disciplines for incorporating behavior within simulation models, to explore what methods could be used within health economic models and to highlight areas for further research. This may lead to better-informed model predictions. The most promising methods identified which could be used to improve modeling of the causal pathways of behavior-change interventions include econometric analyses, structural equation models, data mining and agent-based modeling; the latter of which has the advantage of being able to incorporate the non-linear, dynamic influences on behavior, including social and spatial networks. Twenty-two studies were identified which quantify behavioral theories within simulation models. These studies highlight the importance of combining individual decision making and interactions with the environment and demonstrate the importance of social norms in determining behavior. However, there are many theoretical and practical limitations of quantifying behavioral theory. Further research is needed about the use of agent-based models for health economic modeling, and the potential use of behavior maintenance theories and data mining
Interactions between proteins bound to biomembranes
We study a physical model for the interaction between general inclusions
bound to fluid membranes that possess finite tension, as well as the usual
bending rigidity. We are motivated by an interest in proteins bound to cell
membranes that apply forces to these membranes, due to either entropic or
direct chemical interactions. We find an exact analytic solution for the
repulsive interaction between two similar circularly symmetric inclusions. This
repulsion extends over length scales of order tens of nanometers, and contrasts
with the membrane-mediated contact attraction for similar inclusions on
tensionless membranes. For non circularly symmetric inclusions we study the
small, algebraically long-ranged, attractive contribution to the force that
arises. We discuss the relevance of our results to biological phenomena, such
as the budding of caveolae from cell membranes and the striations that are
observed on their coats.Comment: 22 pages, 2 figure
Effect of liraglutide on cardiovascular outcomes in elderly patients: A post hoc analysis of a randomized controlled trial
Background: Comorbidities and complications associ-ated with type 2 diabetes mellitus (T2DM) increase with age, making treatment of elderly persons with this condition chal-lenging. Clinical data on the effect of antihyperglycemic treat-ment on cardiovascular (CV) events in elderly persons are limited (1). The U.S. Food and Drug Administration and Euro-pean Medicines Agency recommend collecting comprehen-sive data on elderly patients with diabetes, particularly those aged 75 years or older, to inform appropriate treatment of this growing populatio
Perspectives on multiscale modelling and experiments to accelerate materials development for fusion
Prediction of material performance in fusion reactor environments relies on computational modelling, and will continue to do so until the first generation of fusion power plants come on line and allow long-term behaviour to be observed. In the meantime, the modelling is supported by experiments that attempt to replicate some aspects of the eventual operational conditions. In 2019, a group of leading experts met under the umbrella of the IEA to discuss the current position and ongoing challenges in modelling of fusion materials and how advanced experimental characterisation is aiding model improvement. This review draws from the discussions held during that workshop. Topics covering modelling of irradiation-induced defect production and fundamental properties, gas behaviour, clustering and segregation, defect evolution and interactions are discussed, as well as new and novel multiscale simulation approaches, and the latest efforts to link modelling to experiments through advanced observation and characterisation techniques.MRG, SLD, and DRM acknowledge funding by the RCUK Energy Programme [grant number EP/T012250/1]. Part of this work has been carried out within the framework of the EUROFusion Consortium and has received funding from the Euratom research and training programme 2014–2018 and 2019–2020 under grant Agreement No. 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. JRT acknowledges funding from the US Department of Energy (DOE) through grant DE-SC0017899. ZB, LY,BDW, and SJZ acknowledge funding through the US DOE Fusion Energy Sciences grant DE-SC0006661ZB, LY and BDW also were partially supported from the US DOE Office of Science, Office of Fusion Energy Sciences and Office of Advanced Scientific Computing Research through the Scientific Discovery through Advanced Computing (SciDAC) project on Plasma-Surface Interactions. JMa acknowledges support from the US-DOEs Office of Fusion Energy Sciences (US-DOE), project DE-SC0019157. Pacific Northwest National Laboratory is operated by Battelle Memorial Institute for the US Department of Energy (DOE) under contract DE-AC05-76RL01830. YO and YZ were supported as part of the Energy Dissipation to Defect Evolution (EDDE), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under contract number DE-AC05-00OR22725. TS and TT are supported by JSPS KAKENHI Grant Number 19K05338
Current status of turbulent dynamo theory: From large-scale to small-scale dynamos
Several recent advances in turbulent dynamo theory are reviewed. High
resolution simulations of small-scale and large-scale dynamo action in periodic
domains are compared with each other and contrasted with similar results at low
magnetic Prandtl numbers. It is argued that all the different cases show
similarities at intermediate length scales. On the other hand, in the presence
of helicity of the turbulence, power develops on large scales, which is not
present in non-helical small-scale turbulent dynamos. At small length scales,
differences occur in connection with the dissipation cutoff scales associated
with the respective value of the magnetic Prandtl number. These differences are
found to be independent of whether or not there is large-scale dynamo action.
However, large-scale dynamos in homogeneous systems are shown to suffer from
resistive slow-down even at intermediate length scales. The results from
simulations are connected to mean field theory and its applications. Recent
work on helicity fluxes to alleviate large-scale dynamo quenching, shear
dynamos, nonlocal effects and magnetic structures from strong density
stratification are highlighted. Several insights which arise from analytic
considerations of small-scale dynamos are discussed.Comment: 36 pages, 11 figures, Spa. Sci. Rev., submitted to the special issue
"Magnetism in the Universe" (ed. A. Balogh
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