2,435 research outputs found

    Resource Use Efficiency of Cassava farmers in Akwa Ibom State, Nigeria

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    This study examined the resource use efficiency of cassava farmers in Akwa Ibom State, Nigeria. Data collated from 100 farmers selected using a multi stage random sampling technique were subjected to statistical and economic analyses to unveil the pattern of resource use efficiency in cassava enterprise. Result from the ordinary least square multiple regression informed that 92 percent of the variation in cassava output was explained by farm size, fertilizer use, cuttings and labour inputs, with only farm size and cuttings being significant at five percent level. Data on resource use efficiency reveal that the farmers were operating in the second stage of production as regards the use of land (farm size), cuttings and labour, thus, implying decreasing returns to scale, whereas for fertilizer use, they operated within the third stage of the production process as Marginal Physical Product (MPP) was below zero. Based on these findings, the study recommends policies to raise the level of resource use especially through the provision and maintenance of an efficient input delivery system. Keywords: Cassava Farmers, Resource Use Efficiency, Returns to Scale, Marginal Physical Produc

    Selection of maize genotypes resistant to pink stem borer and sugarcane borer.

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    Maize is an important economic crop grown in Nigeria. Its production is dramatically affect by the pink stem borer—Sesamia calamistis (Hampson, Noctuidae) and sugarcane borer—Eldana saccharina (Walker, Pyralidae) that are endemic in Southeastern Nigeria. In areas of stress, existing genotypes may marginally do well due to their inherent capabilities. Therefore, it is possible to find useful genes in such areas of stress, since such genes have been responsible for the survival of host crops over the years. Evaluation study was conducted for a range of agronomic characteristics and resistance attributes for 209 local maize collections from Southeastern Nigeria along with three improved check varieties. Field trials were conducted at three locations in a total of four environments in 2001. Highly significant genotypic variances as were noted in all the traits, are indicative of the magnitude of variation that exists among the genotypes, thus providing the opportunity of selection for desirable traits. Furthermore, four traits, namely, leaf feeding, ear damage, stalk lodging and yield were used from across the environments to construct a rank summation index (RSI), which was used to rank the entries for resistance to stem borers. This RSI led to the identification of 11genotypes which represents the best 5% of the 212 genotypes in resistance ability. Genotype AMA TZBR-WC1 (from International Institute of Tropical Agriculture (IITA), Ibadan) had the best overall resistance levels, followed by genotypes SE NG-77 and SE NG-67 (from Umuahia North), SE NG-62 (from Ikwuano), SE NG-148 (from Ukwa West), SE NG-106 (from Bende), SE NG-119 (from Isiala Ngwa), SE NG-33 (from Ikwuano) and SE NG-65 (from Umuahia North)

    Lessons from the Congested Clique Applied to MapReduce

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    The main results of this paper are (I) a simulation algorithm which, under quite general constraints, transforms algorithms running on the Congested Clique into algorithms running in the MapReduce model, and (II) a distributed O(Δ)O(\Delta)-coloring algorithm running on the Congested Clique which has an expected running time of (i) O(1)O(1) rounds, if Δ≄Θ(log⁥4n)\Delta \geq \Theta(\log^4 n); and (ii) O(log⁥log⁥n)O(\log \log n) rounds otherwise. Applying the simulation theorem to the Congested-Clique O(Δ)O(\Delta)-coloring algorithm yields an O(1)O(1)-round O(Δ)O(\Delta)-coloring algorithm in the MapReduce model. Our simulation algorithm illustrates a natural correspondence between per-node bandwidth in the Congested Clique model and memory per machine in the MapReduce model. In the Congested Clique (and more generally, any network in the CONGEST\mathcal{CONGEST} model), the major impediment to constructing fast algorithms is the O(log⁥n)O(\log n) restriction on message sizes. Similarly, in the MapReduce model, the combined restrictions on memory per machine and total system memory have a dominant effect on algorithm design. In showing a fairly general simulation algorithm, we highlight the similarities and differences between these models.Comment: 15 page

    Lactate signalling regulates fungal ÎČ-glucan masking and immune evasion

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    AJPB: This work was supported by the European Research Council (STRIFE, ERC- 2009-AdG-249793), The UK Medical Research Council (MR/M026663/1), the UK Biotechnology and Biological Research Council (BB/K017365/1), the Wellcome Trust (080088; 097377). ERB: This work was supported by the UK Biotechnology and Biological Research Council (BB/M014525/1). GMA: Supported by the CNPq-Brazil (Science without Borders fellowship 202976/2014-9). GDB: Wellcome Trust (102705). CAM: This work was supported by the UK Medical Research Council (G0400284). DMM: This work was supported by UK National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC/K000306/1). NARG/JW: Wellcome Trust (086827, 075470,101873) and Wellcome Trust Strategic Award in Medical Mycology and Fungal Immunology (097377). ALL: This work was supported by the MRC Centre for Medical Mycology and the University of Aberdeen (MR/N006364/1).Peer reviewedPostprin

    Zoophilic behavior in a patient with posterior cerebral arterial aneurysm

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    This paper presents a clinical co-morbidity between a cerebral arterial aneurysm and a zoophilic behavior. This association has not been previously described before in the literature cited by PubMed.A 42-years old patient, without previous medical history, presented at the hospital with quite sudden onset of zoophilic behavior, disorientation and altered consciousness, was investigated and diagnosed with an aneurysm in the posterior cerebral artery.The case is unique due to the uncommon psychiatric presentation (zoophilic behavior), and its organic substrate: the presence of posterior cerebral arterial aneurysm with interpeduncular locatio

    Tectonic and stratigraphic evolution based on seismic sequence stratigraphy: Central rift section of the campos basin, offshore brazil

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    The rift section of the Brazilian basins represent the sedimentary record associated with the first stages of Gondwana break‐up in the Early Cretaceous phase (Berriasian to Aptian). The rift succession of the Campos Basin constitutes one of the main petroleum systems of Brazil’s marginal basins. This interval contains the main source rock and important reservoirs in the Lagoa Feia Group deposits. The Lagoa Feia Group is characterized by siliciclastic, carbonate and evaporite sediments deposited during the rift and post‐rift phases. Despite the economic relevance, little is known in stratigraphic terms regarding this rift interval. To date, most studies of the Lagoa Feia Group have adopted a lithostratigraphic approach, while this study proposes a tectonostrati-graphic framework for the deep‐rift succession of the Campos Basin (Lagoa Feia Group), using the fundamentals of seismic sequence stratigraphy. This work also aims to establish a methodological and practical procedure for the stratigraphic analysis of rift basins, using seismic data and seismofacies, and focusing on tectonicstratigraphic analysis. The dataset comprised 2D seismic lines, core and lithological logs from exploration wells. Three seismic facies were identified based on reflector patterns and lithologic data from well cores, providing an improved subdivision of the pre‐, syn‐ and post‐rift stages. The syn‐rift stage was further subdivided based on the geometric patterns of the reflectors. Tectonics was the main controlling factor in the sedimentary succession, and the pattern and geometry of the seismic reflectors of the syn‐rift interval in the Campos Basin allowed the identification of three tectonic systems tracts: (i) a Rift Initiation Systems Tract; (ii) a High Tectonic Activity Systems Tract and (iii) a Low Tectonic Activity Systems Tract

    Parameterized Verification of Safety Properties in Ad Hoc Network Protocols

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    We summarize the main results proved in recent work on the parameterized verification of safety properties for ad hoc network protocols. We consider a model in which the communication topology of a network is represented as a graph. Nodes represent states of individual processes. Adjacent nodes represent single-hop neighbors. Processes are finite state automata that communicate via selective broadcast messages. Reception of a broadcast is restricted to single-hop neighbors. For this model we consider a decision problem that can be expressed as the verification of the existence of an initial topology in which the execution of the protocol can lead to a configuration with at least one node in a certain state. The decision problem is parametric both on the size and on the form of the communication topology of the initial configurations. We draw a complete picture of the decidability and complexity boundaries of this problem according to various assumptions on the possible topologies.Comment: In Proceedings PACO 2011, arXiv:1108.145
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