5,416 research outputs found

    Climate Change Impacts on Hydro-generation and Land Suitability for Agriculture in Least Developed Countries of the Greater Mekong Sub-region

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    The main objective of this report is to understand the climate induced changes in precipitation, water inflow, and land-suitability for food and bioenergy production in the case study countries (Cambodia, Laos and Myanmar) where electricity system is heavily dependent on hydro and the economy of the rural population heavily depends on the agriculture. Rural agrarian communities are highly vulnerable to climate change as their income heavily depends on agriculture and has very limited access to electricity (Morton 2007). Access to electricity and climate resilience in the agriculture sector are expected to facilitate enhanced economic activities, secure jobs, and income generated by the sector and its supply chain for rural communities. Further, increased development, driven by access to clean energy and employment, is also key to achieve several SDGs such as health and wellbeing, education, poverty alleviation, reducing inequality and promoting gender equality. This report quantifies and analyses the impacts of climate change on water availability and land suitability for key crops in three least developed countries in the Greater Mekong Sub-region, namely, Cambodia, Laos and Myanmar. We use different databases (CMIP5 for climate and ISIMIP for hydropower data) as well as a modelling tool (land suitability model) to conduct these analyses

    Low scale gravity as the source of neutrino masses?

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    We address the question whether low-scale gravity alone can generate the neutrino mass matrix needed to accommodate the observed phenomenology. In low-scale gravity the neutrino mass matrix in the flavor basis is characterized by one parameter (the gravity scale M_X) and by an exact or approximate flavor blindness (namely, all elements of the mass matrix are of comparable size). Neutrino masses and mixings are consistent with the observational data for certain values of the matrix elements, but only when the spectrum of mass is inverted or degenerate. For the latter type of spectra the parameter M_{ee} probed in double beta experiments and the mass parameter probed by cosmology are close to existing upper limits.Comment: 10 pages, 1 figur

    Functional Dynamics of PDZ Binding Domains: A Normal Mode Analysis

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    PDZ (Post-synaptic density-95/discs large/zonula occludens-1) domains are relatively small (80 to 120 residues) protein binding modules central in the organization of receptor clusters and in the association of cellular proteins. Their main function is to bind C-terminals of selected proteins that are recognized through specific amino-acids in their carboxyl end. Binding is associated with a deformation of the PDZ native structure and is responsible for dynamical changes in regions not in direct contact with the target. We investigate how this deformation is related to the harmonic dynamics of the PDZ structure and show that one low-frequency collective normal mode, characterized by the concerted movements of different secondary structures, is involved in the binding process. Our results suggest that even minimal structural changes are responsible of communication between distant regions of the protein, in agreement with recent Nuclear Magnetic Resonance (NMR) experiments. Thus PDZ domains are a very clear example of how collective normal modes are able to characterize the relation between function and dynamics of proteins, and to provide indications on the precursors of binding/unbonding events.Comment: 25 pages, 10 figures, submitted to Biophysical Journa

    The Two Faces of Anomaly Mediation

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    Anomaly mediation is a ubiquitous source of supersymmetry (SUSY) breaking which appears in almost every theory of supergravity. In this paper, we show that anomaly mediation really consists of two physically distinct phenomena, which we dub "gravitino mediation" and "Kahler mediation". Gravitino mediation arises from minimally uplifting SUSY anti-de Sitter (AdS) space to Minkowski space, generating soft masses proportional to the gravitino mass. Kahler mediation arises when visible sector fields have linear couplings to SUSY breaking in the Kahler potential, generating soft masses proportional to beta function coefficients. In the literature, these two phenomena are lumped together under the name "anomaly mediation", but here we demonstrate that they can be physically disentangled by measuring associated couplings to the goldstino. In particular, we use the example of gaugino soft masses to show that gravitino mediation generates soft masses without corresponding goldstino couplings. This result naively violates the goldstino equivalence theorem but is in fact necessary for supercurrent conservation in AdS space. Since gravitino mediation persists even when the visible sector is sequestered from SUSY breaking, we can use the absence of goldstino couplings as an unambiguous definition of sequestering.Comment: 21 pages, 1 table; v2, references added, extended discussion in introduction and appendix; v3, JHEP versio

    Generalizing the O(N)-field theory to N-colored manifolds of arbitrary internal dimension D

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    We introduce a geometric generalization of the O(N)-field theory that describes N-colored membranes with arbitrary dimension D. As the O(N)-model reduces in the limit N->0 to self-avoiding polymers, the N-colored manifold model leads to self-avoiding tethered membranes. In the other limit, for inner dimension D->1, the manifold model reduces to the O(N)-field theory. We analyze the scaling properties of the model at criticality by a one-loop perturbative renormalization group analysis around an upper critical line. The freedom to optimize with respect to the expansion point on this line allows us to obtain the exponent \nu of standard field theory to much better precision that the usual 1-loop calculations. Some other field theoretical techniques, such as the large N limit and Hartree approximation, can also be applied to this model. By comparison of low and high temperature expansions, we arrive at a conjecture for the nature of droplets dominating the 3d-Ising model at criticality, which is satisfied by our numerical results. We can also construct an appropriate generalization that describes cubic anisotropy, by adding an interaction between manifolds of the same color. The two parameter space includes a variety of new phases and fixed points, some with Ising criticality, enabling us to extract a remarkably precise value of 0.6315 for the exponent \nu in d=3. A particular limit of the model with cubic anisotropy corresponds to the random bond Ising problem; unlike the field theory formulation, we find a fixed point describing this system at 1-loop order.Comment: 57 pages latex, 26 figures included in the tex

    Enhanced stochastic optimization algorithm for finding effective multi-target therapeutics

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    <p>Abstract</p> <p>Background</p> <p>For treating a complex disease such as cancer, we need effective means to control the biological network that underlies the disease. However, biological networks are typically robust to external perturbations, making it difficult to beneficially alter the network dynamics by controlling a single target. In fact, multi-target therapeutics is often more effective compared to monotherapies, and combinatory drugs are commonly used these days for treating various diseases. A practical challenge in combination therapy is that the number of possible drug combinations increases exponentially, which makes the prediction of the optimal drug combination a difficult combinatorial optimization problem. Recently, a stochastic optimization algorithm called the Gur Game algorithm was proposed for drug optimization, which was shown to be very efficient in finding potent drug combinations.</p> <p>Results</p> <p>In this paper, we propose a novel stochastic optimization algorithm that can be used for effective optimization of combinatory drugs. The proposed algorithm analyzes how the concentration change of a specific drug affects the overall drug response, thereby making an informed guess on how the concentration should be updated to improve the drug response. We evaluated the performance of the proposed algorithm based on various drug response functions, and compared it with the Gur Game algorithm.</p> <p>Conclusions</p> <p>Numerical experiments clearly show that the proposed algorithm significantly outperforms the original Gur Game algorithm, in terms of reliability and efficiency. This enhanced optimization algorithm can provide an effective framework for identifying potent drug combinations that lead to optimal drug response.</p

    Decoding the Complexity of Systemic Inflammation Predictors in Locally Advanced Cervical Cancer, with Hemoglobin as the Hidden Key (the ESTHER Study)

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    Simple Summary We explored whether specific factors, like inflammation indicators in the blood, could help predict treatment outcomes for locally advanced cervical cancer (LACC). LACC is generally treated with a combination of chemotherapy and radiation. We wanted to see if these factors could help physicians personalize treatments for better results. Our study involved looking at various aspects, including inflammation indices in the blood and various clinical treatment details, in LACC patients. While some factors, such as age and hemoglobin levels, seemed to predict outcomes, there was no clear connection between inflammation indicators in the blood and results. These findings challenge previous ideas and highlight the importance of considering multiple factors to predict the prognoses of LACC patients.Abstract Locally advanced cervical cancer (LACC) is treated with concurrent chemoradiation (CRT). Predictive models could improve the outcome through treatment personalization. Several factors influence prognosis in LACC, but the role of systemic inflammation indices (IIs) is unclear. This study aims to assess the correlation between IIs and prognosis in a large patient cohort considering several clinical data. We retrospectively analyzed pretreatment IIs (NLR, PLR, MLR, SII, LLR, COP-NLR, APRI, ALRI, SIRI, and ANRI) in 173 LACC patients. Patient, tumor, and treatment characteristics were also considered. Univariate and multivariate Cox's regressions were conducted to assess associations between IIs and clinical factors with local control (LC), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS). Univariate analysis showed significant correlations between age, HB levels, tumor stage, FIGO stage, and CRT dose with survival outcomes. Specific pretreatment IIs (NLR, PLR, APRI, ANRI, and COP-NLR) demonstrated associations only with LC. The multivariate analysis confirmed Hb levels, CRT dose, and age as significant predictors of OS, while no II was correlated with any clinical outcome. The study findings contradict some prior research on IIs in LACC, emphasizing the need for comprehensive assessments of potential confounding variables

    Mirror model for sterile neutrinos

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    Sterile neutrinos are studied as subdominant contribution to solar neutrino physics. The mirror-matter neutrinos are considered as sterile neutrinos. We use the symmetric mirror model with gravitational communication between mirror and visible sectors. This communication term provides mixing between visible and mirror neutrinos with the basic scale mu=v^2/M_Pl=5*10^-6 eV, where v=174 GeV is the vacuum expectation value of the standard electroweak group and M_Pl is the Planckian mass. It is demonstrated that each mass eigenstate of active neutrinos splits into two states separated by small Delta m^2. Unsuppressed oscillations between active and sterile neutrinos nu_a --> nu_s occur only in transitions between each of these close pairs (``windows''). These oscillations are characterized by very small Delta m^2 and can suppress the flux and distort spectrum of pp-neutrinos in detectable way. The other observable effect is anomalous seasonal variation of neutrino flux, which appears in LMA solution. The considered subdominant neutrino oscillations nu_a nu_s can reveal itself as big effects in observations of supernova neutrinos and high energy (HE) neutrinos. In the case of HE neutrinos they can provide a very large diffuse flux of active neutrinos unconstrained by the e-m cascade upper limit.Comment: 30 pags, 5 figs. V2: Refs added, minor editing. Accepted in NP
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