269 research outputs found
Madagascar's future climate change intensified actions and policy reforms: fostering local initiatives or business as usual?
As Madagascar, like all other countries on the globe, is gearing up for the meeting of the 21 st Conference of Parties (COP21 ) of UN’s Framework Climate Change Convention (UNFCCC), we reflect on the persistent failure of development policies in Madagascar, and suggest that there may be fundamental flaws in perceptions about development interventions and transferability of solutions, resulting in a country in permanent crisis despite the island’s great potential. The major official donors claim that they had left the island to itself since the 2009 crisis. However, World Bank statistics show that, in current terms, Madagascar was receiving US 500 million in 2013. In the same interval, the Gross National Product (GDP) per capita remained basically the same (equivalent to 440 US400 millions en 1990 et US/capita en 2014). À supposer que la COP21 ait pour résultat des investissements massifs dans la réduction des émissions de carbone et dans l’adaptation au changement climatique, nous proposons que, a minima, ces nouveaux projets, plans, programmes et politiques devraient viser à plus de durabilité en appliquant les Évaluations environnementales et sociales à tous les niveaux requis et que, de préférence, cet afflux de capitaux représente l’opportunité d’une nouvelle approche du développement. En particulier, nous proposons une focalisation sur la capacité générative (définie somme la capacité à générer spontanément de nouvelles options de développement) des citoyens malgaches de mieux tirer parti des ressources naturelles et de l’infrastructure des technologies de l’information et des communications (TIC) déjà en place. L’ambition d’un tel programme n’est ni sans risques ni sans embûches, mais nous estimons qu’il s’agit d’un moyen de sortir du cycle actuel et auto-entretenu de sousperformance qui existe à Madagascar. Cet essai propose ainsi de mettre en cause le statut quo afin de stimuler la discussion et une nouvelle approche. À défaut et sans changement, les habitants comme les observateurs connaitront, dans 20 ans, les frustrations d’aujourd’hui, face à l’état du développement de Madagascar
Market opportunities, customer desires and purchasing selectiveness modelling in multi-layered cellular automata: A study case on organizational survivability
The present work aims to contribute to a better understanding of the dynamics of organizational competition and survival in a supply chain network market context, while highlighting the potential of multi-layered cellular automata models as frameworks for accommodating increasing levels of complexity. More particularly, the implementation of inter-layer rules associated to k-bit words modelling of market opportunities, customer desires and purchasing selectiveness, and their impact on the dynamics of an evolutionary “ecology” of suppliers, competing organizations, and customers, following a complex adaptive systems approach is described and illustrated through a study case on organizational survivability. The implications of the study results—reflecting the interplay between market environment, competitors’ strategic choice, and corresponding ability to succeed, survive crises and proliferate—are then discussed and the main aims of the work ahead highlighted.info:eu-repo/semantics/acceptedVersio
Fitness voter model: damped oscillations and anomalous consensus
We study the dynamics of opinion formation in a heterogeneous voter model on a complete graph, in which each agent is endowed with an integer fitness parameter k≥0, in addition to its + or - opinion state. The evolution of the distribution of k-values and the opinion dynamics are coupled together, so as to allow the system to dynamically develop heterogeneity and memory in a simple way. When two agents with different opinions interact, their k-values are compared, and with probability p the agent with the lower value adopts the opinion of the one with the higher value, while with probability 1-p the opposite happens. The agent that keeps its opinion (winning agent) increments its k-value by one. We study the dynamics of the system in the entire 0≤p≤1 range and compare with the case p=1/2, in which opinions are decoupled from the k-values and the dynamics is equivalent to that of the standard voter model. When 0≤p<1/2, agents with higher k-values are less persuasive, and the system approaches exponentially fast to the consensus state of the initial majority opinion. The mean consensus time τ appears to grow logarithmically with the number of agents N, and it is greatly decreased relative to the linear behavior τ∼N found in the standard voter model. When 1/2<p≤1, agents with higher k-values are more persuasive, and the system initially relaxes to a state with an even coexistence of opinions, but eventually reaches consensus by finite-size fluctuations. The approach to the coexistence state is monotonic for 1/2<p<po≃0.8, while for po≤p≤1 there are damped oscillations around the coexistence value. The final approach to coexistence is approximately a power law t-b(p) in both regimes, where the exponent b increases with p. Also, τ increases respect to the standard voter model, although it still scales linearly with N. The p=1 case is special, with a relaxation to coexistence that scales as t-2.73 and a consensus time that scales as τ∼Nβ, with β≃1.45.Instituto de Física de Líquidos y Sistemas Biológico
Magnetism, FeS colloids, and Origins of Life
A number of features of living systems: reversible interactions and weak
bonds underlying motor-dynamics; gel-sol transitions; cellular connected
fractal organization; asymmetry in interactions and organization; quantum
coherent phenomena; to name some, can have a natural accounting via
interactions, which we therefore seek to incorporate by expanding the horizons
of `chemistry-only' approaches to the origins of life. It is suggested that the
magnetic 'face' of the minerals from the inorganic world, recognized to have
played a pivotal role in initiating Life, may throw light on some of these
issues. A magnetic environment in the form of rocks in the Hadean Ocean could
have enabled the accretion and therefore an ordered confinement of
super-paramagnetic colloids within a structured phase. A moderate H-field can
help magnetic nano-particles to not only overcome thermal fluctuations but also
harness them. Such controlled dynamics brings in the possibility of accessing
quantum effects, which together with frustrations in magnetic ordering and
hysteresis (a natural mechanism for a primitive memory) could throw light on
the birth of biological information which, as Abel argues, requires a
combination of order and complexity. This scenario gains strength from
observations of scale-free framboidal forms of the greigite mineral, with a
magnetic basis of assembly. And greigite's metabolic potential plays a key role
in the mound scenario of Russell and coworkers-an expansion of which is
suggested for including magnetism.Comment: 42 pages, 5 figures, to be published in A.R. Memorial volume, Ed
Krishnaswami Alladi, Springer 201
Patient-reported wellbeing and clinical disease measures over time captured by multivariate trajectories of disease activity in individuals with juvenile idiopathic arthritis in the UK: a multicentre prospective longitudinal study
Background: Juvenile idiopathic arthritis (JIA) is a heterogeneous disease, the signs and symptoms of which can be
summarised with use of composite disease activity measures, including the clinical Juvenile Arthritis Disease Activity
Score (cJADAS). However, clusters of children and young people might experience different global patterns in their
signs and symptoms of disease, which might run in parallel or diverge over time. We aimed to identify such clusters in
the 3 years after a diagnosis of JIA. The identification of these clusters would allow for a greater understanding of
disease progression in JIA, including how physician-reported and patient-reported outcomes relate to each other over
the JIA disease course. /
Methods: In this multicentre prospective longitudinal study, we included children and young people recruited before
Jan 1, 2015, to the Childhood Arthritis Prospective Study (CAPS), a UK multicentre inception cohort. Participants
without a cJADAS score were excluded. To assess groups of children and young people with similar disease patterns in
active joint count, physician’s global assessment, and patient or parental global evaluation, we used latent profile analysis
at initial presentation to paediatric rheumatology and multivariate group-based trajectory models for the following
3 years. Optimal models were selected on the basis of a combination of model fit, clinical plausibility, and model parsimony. /
Finding: Between Jan 1, 2001, and Dec 31, 2014, 1423 children and young people with JIA were recruited to CAPS,
239 of whom were excluded, resulting in a final study population of 1184 children and young people. We identified
five clusters at baseline and six trajectory groups using longitudinal follow-up data. Disease course was not well
predicted from clusters at baseline; however, in both cross-sectional and longitudinal analyses, substantial proportions
of children and young people had high patient or parent global scores despite low or improving joint counts and
physician global scores. Participants in these groups were older, and a higher proportion of them had enthesitisrelated JIA and lower socioeconomic status, compared with those in other groups. /
Interpretation: Almost one in four children and young people with JIA in our study reported persistent, high patient
or parent global scores despite having low or improving active joint counts and physician’s global scores. Distinct
patient subgroups defined by disease manifestation or trajectories of progression could help to better personalise
health-care services and treatment plans for individuals with JIA. /
Funding: Medical Research Council, Versus Arthritis, Great Ormond Street Hospital Children’s Charity, Olivia’s Vision,
and National Institute for Health Researc
Gastrin-Releasing Peptide Signaling Plays a Limited and Subtle Role in Amygdala Physiology and Aversive Memory
Links between synaptic plasticity in the lateral amygdala (LA) and Pavlovian fear learning are well established. Neuropeptides including gastrin-releasing peptide (GRP) can modulate LA function. GRP increases inhibition in the LA and mice lacking the GRP receptor (GRPR KO) show more pronounced and persistent fear after single-trial associative learning. Here, we confirmed these initial findings and examined whether they extrapolate to more aspects of amygdala physiology and to other forms of aversive associative learning. GRP application in brain slices from wildtype but not GRPR KO mice increased spontaneous inhibitory activity in LA pyramidal neurons. In amygdala slices from GRPR KO mice, GRP did not increase inhibitory activity. In comparison to wildtype, short- but not long-term plasticity was increased in the cortico-lateral amygdala (LA) pathway of GRPR KO amygdala slices, whereas no changes were detected in the thalamo-LA pathway. In addition, GRPR KO mice showed enhanced fear evoked by single-trial conditioning and reduced spontaneous firing of neurons in the central nucleus of the amygdala (CeA). Altogether, these results are consistent with a potentially important modulatory role of GRP/GRPR signaling in the amygdala. However, administration of GRP or the GRPR antagonist (D-Phe6, Leu-NHEt13, des-Met14)-Bombesin (6–14) did not affect amygdala LTP in brain slices, nor did they affect the expression of conditioned fear following intra-amygdala administration. GRPR KO mice also failed to show differences in fear expression and extinction after multiple-trial fear conditioning, and there were no differences in conditioned taste aversion or gustatory neophobia. Collectively, our data indicate that GRP/GRPR signaling modulates amygdala physiology in a paradigm-specific fashion that likely is insufficient to generate therapeutic effects across amygdala-dependent disorders
Tuple-based semantic and structural mapping for a sustainable interoperability
Abstract. Enterprises are demanded to collaborate and establish partnerships to reach global business and markets. However, due to the different sources of models and semantics, organizations are experiencing difficulties exchanging vital information electronically and seamlessly, even when they operate in related business environments. This situation is even worst in the advent of the evolution of the enterprise systems and applications, whose dynamics result in increasing the interoperability problem due to the continuous need for model adjustments and semantics harmonization. To contribute for a long term stable interoperable enterprise operating environment, the authors propose the integration of traceability functionalities in information systems as a way to support such sustainability. Either data, semantic, and structural mappings between partner enterprises in the complex network should be modelled as tuples and stored in a knowledge base for communication support with reasoning capabilities, thus allowing to trace, monitor and support the stability maintenance of a system's interoperable state
Critical analysis of the Bennett-Riedel attack on secure cryptographic key distributions via the Kirchhoff-law-Johnson-noise scheme
Recently, Bennett and Riedel (BR) (http://arxiv.org/abs/1303.7435v1) argued that thermodynamics is not essential in the Kirchhoff-law–Johnson-noise (KLJN) classical physical cryptographic exchange method in an effort to disprove the security of the KLJN scheme. They attempted to demonstrate this by introducing a dissipation-free deterministic key exchange method with two batteries and two switches. In the present paper, we first show that BR's scheme is unphysical and that some elements of its assumptions violate basic protocols of secure communication. All our analyses are based on a technically unlimited Eve with infinitely accurate and fast measurements limited only by the laws of physics and statistics. For non-ideal situations and at active (invasive) attacks, the uncertainly principle between measurement duration and statistical errors makes it impossible for Eve to extract the key regardless of the accuracy or speed of her measurements. To show that thermodynamics and noise are essential for the security, we crack the BR system with 100% success via passive attacks, in ten different ways, and demonstrate that the same cracking methods do not function for the KLJN scheme that employs Johnson noise to provide security underpinned by the Second Law of Thermodynamics. We also present a critical analysis of some other claims by BR; for example, we prove that their equations for describing zero security do not apply to the KLJN scheme. Finally we give mathematical security proofs for each BR-attack against the KLJN scheme and conclude that the information theoretic (unconditional) security of the KLJN method has not been successfully challenged.Laszlo B. Kish, Derek Abbott, Claes G. Granqvis
Molecular, Cellular and Physiological Evidences for the Anorexigenic Actions of Nesfatin-1 in Goldfish
Nesfatin-1 is a recently discovered anorexigen encoded in the precursor peptide, nucleobindin-2 (NUCB2) in mammals. To date, nesfatin-1 has not been described in any non-mammalian species, although some information is available in the sequenced genomes of several species. Our objective was to characterize nesfatin-1 in fish.In the present study, we employed molecular, immunohistochemical, and physiological studies to characterize the structure, distribution, and appetite regulatory effects of nesfatin-1 in a non-mammalian vertebrate. A very high conservation in NUCB2 sequences, especially in the nesfatin-1 region was found in lower vertebrates. Abundant expression of NUCB2 mRNA was detected in several tissues including the brain and liver of goldfish. Nesfatin-1-like immunoreactive cells are present in the feeding regulatory nucleus of the hypothalamus and in the gastrointestinal tract of goldfish. Approximately 6-fold increase in NUCB2 mRNA levels was found in the liver after 7-day food-deprivation, and a similar increase was also found after short-term fasting. This points toward a possible liver specific role for NUCB2 in the control of metabolism during food-deprivation. Meanwhile, ∼2-fold increase at 1 and 3 h post-feeding and an ∼3-fold reduction after a 7-day food-deprivation was observed in NUCB2 mRNA in the goldfish hypothalamus. In vivo, a single intraperitoneal injection of the full-length native (goldfish; gf) nesfatin-1 at a dose of 50 ng/g body weight induced a 23% reduction of food intake one hour post-injection in goldfish. Furthermore, intracerebroventricular injection of gfnesfatin-1 at a dose of 5 ng/g body weight resulted in ∼50% reduction in food intake.Our results provide molecular, anatomical and functional evidences to support potential anorectic and metabolic roles for endogenous nesfatin-1 in goldfish. Collectively, we provide novel information on NUCB2 in non-mammals and an anorexigenic role for nesfatin-1 in goldfish
Prioritization and Evaluation of Depression Candidate Genes by Combining Multidimensional Data Resources
Large scale and individual genetic studies have suggested numerous susceptible genes for depression in the past decade without conclusive results. There is a strong need to review and integrate multi-dimensional data for follow up validation. The present study aimed to apply prioritization procedures to build-up an evidence-based candidate genes dataset for depression.Depression candidate genes were collected in human and animal studies across various data resources. Each gene was scored according to its magnitude of evidence related to depression and was multiplied by a source-specific weight to form a combined score measure. All genes were evaluated through a prioritization system to obtain an optimal weight matrix to rank their relative importance with depression using the combined scores. The resulting candidate gene list for depression (DEPgenes) was further evaluated by a genome-wide association (GWA) dataset and microarray gene expression in human tissues.A total of 5,055 candidate genes (4,850 genes from human and 387 genes from animal studies with 182 being overlapped) were included from seven data sources. Through the prioritization procedures, we identified 169 DEPgenes, which exhibited high chance to be associated with depression in GWA dataset (Wilcoxon rank-sum test, p = 0.00005). Additionally, the DEPgenes had a higher percentage to express in human brain or nerve related tissues than non-DEPgenes, supporting the neurotransmitter and neuroplasticity theories in depression.With comprehensive data collection and curation and an application of integrative approach, we successfully generated DEPgenes through an effective gene prioritization system. The prioritized DEPgenes are promising for future biological experiments or replication efforts to discover the underlying molecular mechanisms for depression
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