1,207 research outputs found
A note on edge oriented reinforced random walks and RWRE
This work introduces the notion of edge oriented reinforced random walk which
proposes in a general framework an alternative understanding of the annealed
law of random walks in random environment.Comment: 5 page
¿Por qué poca desigualdad fomenta el crecimiento: el ahorro y la inversión de los pobres
(Disponible en idioma inglés únicamente) En este trabajo se tratan las maneras en que los acontecimientos macroeconómicos pueden presionar a los bancos y, en casos extremos, conducir a crisis bancarias. Esto puede ocurrir de muchas maneras y no se trata ningún mecanismo específico. Estas causas macroeconómicas de la vulnerabilidad y las crisis de los bancos tienen implicaciones importantes para los regímenes regulatorios y para la política macroeconómica misma. Buena parte del análisis hace hincapié en la necesidad de fijar la política monetaria teniendo en mente la situación del sistema bancario nacional.
Random walks in random Dirichlet environment are transient in dimension
We consider random walks in random Dirichlet environment (RWDE) which is a
special type of random walks in random environment where the exit probabilities
at each site are i.i.d. Dirichlet random variables. On , RWDE are
parameterized by a -uplet of positive reals. We prove that for all values
of the parameters, RWDE are transient in dimension . We also prove that
the Green function has some finite moments and we characterize the finite
moments. Our result is more general and applies for example to finitely
generated symmetric transient Cayley graphs. In terms of reinforced random
walks it implies that directed edge reinforced random walks are transient for
.Comment: New version published at PTRF with an analytic proof of lemma
Comparison between measured and predicted turbulence frequency spectra in ITG and TEM regimes
The observation of distinct peaks in tokamak core reflectometry measurements
- named quasi-coherent-modes (QCMs) - are identified as a signature of
Trapped-Electron-Mode (TEM) turbulence [H. Arnichand et al. 2016 Plasma Phys.
Control. Fusion 58 014037]. This phenomenon is investigated with detailed
linear and nonlinear gyrokinetic simulations using the \gene code. A Tore-Supra
density scan is studied, which traverses through a Linear (LOC) to Saturated
(SOC) Ohmic Confinement transition. The LOC and SOC phases are both simulated
separately. In the LOC phase, where QCMs are observed, TEMs are robustly
predicted unstable in linear studies. In the later SOC phase, where QCMs are no
longer observed, ITG modes are identified. In nonlinear simulations, in the ITG
(SOC) phase, a broadband spectrum is seen. In the TEM (LOC) phase, a clear
emergence of a peak at the TEM frequencies is seen. This is due to reduced
nonlinear frequency broadening of the underlying linear modes in the TEM regime
compared with the ITG regime. A synthetic diagnostic of the nonlinearly
simulated frequency spectra reproduces the features observed in the
reflectometry measurements. These results support the identification of core
QCMs as an experimental marker for TEM turbulenc
"Even if the test result is negative, they should be able to tell us what is wrong with us": a qualitative study of patient expectations of rapid diagnostic tests for malaria.
BACKGROUND: The debate on rapid diagnostic tests (RDTs) for malaria has begun to shift from whether RDTs should be used, to how and under what circumstances their use can be optimized. This has increased the need for a better understanding of the complexities surrounding the role of RDTs in appropriate treatment of fever. Studies have focused on clinician practices, but few have sought to understand patient perspectives, beyond notions of acceptability. METHODS: This qualitative study aimed to explore patient and caregiver perceptions and experiences of RDTs following a trial to assess the introduction of the tests into routine clinical care at four health facilities in one district in Ghana. Six focus group discussions and one in-depth interview were carried out with those who had received an RDT with a negative test result. RESULTS: Patients had high expectations of RDTs. They welcomed the tests as aiding clinical diagnoses and as tools that could communicate their problem better than they could, verbally. However, respondents also believed the tests could identify any cause of illness, beyond malaria. Experiences of patients suggested that RDTs were adopted into an existing system where patients are both physically and intellectually removed from diagnostic processes and where clinicians retain authority that supersedes tests and their results. In this situation, patients did not feel able to articulate a demand for test-driven diagnosis. CONCLUSIONS: Improvements in communication between the health worker and patient, particularly to explain the capabilities of the test and management of RDT negative cases, may both manage patient expectations and promote patient demand for test-driven diagnoses
Caractérisation phénotypique et génétique du riz africain (Oryza glaberrima Steud) phenotypic and genetic characterization of african rice (oryza glaberrima steud)
The agronomic interest of African rice and the morphological similarities with other species, arouse the necessity to characterize African rice for recovery and conservation. The present study aims primarily to characterize phenotypically and genetically African rice for better exploitation in aid of rice producers and consumers. Indeed, the phenotypic characteristics of the rice accessions examined have been determined in two agronomics systems (upland and irrigated) carried out about 235 accessions of African rice; and afterwards, genetic characterization using a specific marker has been carried. At the end of the analyzes, with regard to the phenotypic characters, 22 O.sativa or interspecific accessions differing morphologically on several descriptors were identified. Genetically, out of 19 profiles revealed on a 935-bp band, 14 confirmed the phenotypic results. This study shows that 221 out of 235 accessions are O. glaberrima rice. These results show that the accessions of different species analyzed were confused during the collection. They also seems to validate the possibility of hybridization between the two rice species in peasant environment. The accessions characterized strengthen the conservation effort of African rice. This collection can be used for future studies, particularly with perspective to selection and running African rice with the possibility to establish a genetic model to facilitate the transfer of useful genes from O.glaberrima to O.sativa, while controlling the reproductive barrier. Thus, it will be easy to better exploit the genetic diversity of the African species of cultivated rice
Modelling dependency networks to inform data structures in BIM and smart cities
The pervasive deployment of "smart city" and "smart building" projects in cities world-wide is driving innovation on many fronts including; technology, telematics, engineering and entrepreneurship. This paper focuses on the technical and engineering perspectives of BIM and smart cities, by extending building and urban morphology studies as to respond to the challenges posed by Big Data, and smart infrastructure. The proposed framework incorporates theoretical and modelling descriptions to verify how network-based models can act as the backbone skeletal representation of both building and urban complexity, and yet relate to environmental performance and smart infrastructure. The paper provides some empirical basis to support data information models through building dependency networks as to represent the relationships between different existing and smart infrastructure components. These dependency networks are thought to inform decisions on how to represent building and urban data sets in response to different social and environmental performance requirements, feeding that into void and solid descriptions of data maturity models. It is concluded that network-based models are fundamental to comprehend and represent the complexity of cities and inform urban design and public policy practices, in the design and operation phases of infrastructure projects
Socially-marketed rapid diagnostic tests and ACT in the private sector: ten years of experience in Cambodia.
Whilst some populations have recently experienced dramatic declines in malaria, the majority of those most at risk of Plasmodium falciparum malaria still lack access to effective treatment with artemisinin combination therapy (ACT) and others are already facing parasites resistant to artemisinins.In this context, there is a crucial need to improve both access to and targeting of ACT through greater availability of good quality ACT and parasitological diagnosis. This is an issue of increasing urgency notably in the private commercial sector, which, in many countries, plays an important role in the provision of malaria treatment. The Affordable Medicines Facility for malaria (AMFm) is a recent initiative that aims to increase the provision of affordable ACT in public, private and NGO sectors through a manufacturer-level subsidy. However, to date, there is little documented experience in the programmatic implementation of subsidized ACT in the private sector. Cambodia is in the unique position of having more than 10 years of experience not only in implementing subsidized ACT, but also rapid diagnostic tests (RDT) as part of a nationwide social marketing programme. The programme includes behaviour change communication and the training of private providers as well as the sale and distribution of Malarine, the recommended ACT, and Malacheck, the RDT. This paper describes and evaluates this experience by drawing on the results of household and provider surveys conducted since the start of the programme. The available evidence suggests that providers' and consumers' awareness of Malarine increased rapidly, but that of Malacheck much less so. In addition, improvements in ACT and RDT availability and uptake were relatively slow, particularly in more remote areas.The lack of standardization in the survey methods and the gaps in the data highlight the importance of establishing a clear system for monitoring and evaluation for similar initiatives. Despite these limitations, a number of important lessons can still be learnt. These include the importance of a comprehensive communications strategy and of a sustained and reliable supply of products, with attention to the geographical reach of both. Other important challenges relate to the difficulty in incentivising providers and consumers not only to choose the recommended drug, but to precede this with a confirmatory blood test and ensure that providers adhere to the test results and patients to the treatment regime. In Cambodia, this is particularly complicated due to problems inherent to the drug itself and the emergence of artemisinin resistance
Deciphering the genome structure and paleohistory of _Theobroma cacao_
We sequenced and assembled the genome of _Theobroma cacao_, an economically important tropical fruit tree crop that is the source of chocolate. The assembly corresponds to 76% of the estimated genome size and contains almost all previously described genes, with 82% of them anchored on the 10 _T. cacao_ chromosomes. Analysis of this sequence information highlighted specific expansion of some gene families during evolution, for example flavonoid-related genes. It also provides a major source of candidate genes for _T. cacao_ disease resistance and quality improvement. Based on the inferred paleohistory of the T. cacao genome, we propose an evolutionary scenario whereby the ten _T. cacao_ chromosomes were shaped from an ancestor through eleven chromosome fusions. The _T. cacao_ genome can be considered as a simple living relic of higher plant evolution
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