26,157 research outputs found

    The diversity of gendered adaptation strategies to climate change of Indian farmers: a feminist intersectional approach

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    This paper examines climate change adaptation and gender issues through an application of a feminist intersectional approach. This approach permits the identification of diverse adaptation responses arising from the existence of multiple and fragmented dimensions of identity (including gender) that intersect with power relations to shape situation-specific interactions between farmers and ecosystems. Based on results from contrasting research cases in Bihar and Uttarakhand, India, this paper demonstrates, inter alia, that there are geographically determined gendered preferences and adoption strategies regarding adaptation options and that these are influenced by the socio-ecological context and institutional dynamics. Intersecting identities, such as caste, wealth, age and gender, influence decisions and reveal power dynamics and negotiation within the household and the community, as well as barriers to adaptation among groups. Overall, the findings suggest that a feminist intersectional approach does appear to be useful and worth further exploration in the context of climate change adaptation. In particular, future research could benefit from more emphasis on a nuanced analysis of the intra-gender differences that shape adaptive capacity to climate change

    Universality of low-energy scattering in (2+1) dimensions

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    We prove that, in (2+1) dimensions, the S-wave phase shift, δ0(k) \delta_0(k), k being the c.m. momentum, vanishes as either δ0cln(k/m)orδ0O(k2)\delta_0 \to {c\over \ln (k/m)} or \delta_0 \to O(k^2) as k0k\to 0. The constant cc is universal and c=π/2c=\pi/2. This result is established first in the framework of the Schr\"odinger equation for a large class of potentials, second for a massive field theory from proved analyticity and unitarity, and, finally, we look at perturbation theory in ϕ34\phi_3^4 and study its relation to our non-perturbative result. The remarkable fact here is that in n-th order the perturbative amplitude diverges like (lnk)n(\ln k)^n as k0k\to 0, while the full amplitude vanishes as (lnk)1(\ln k)^{-1}. We show how these two facts can be reconciled.Comment: 23 pages, Late

    The envelope of IRC+10216 reflecting the galactic light: UBV surface brightness photometry and interpretation

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    We present and analyse new optical images of the dust envelope surrounding the high mass-loss carbon star IRC+10216. This envelope is seen due to external illumination by galactic light. Intensity profiles and colors of the nebula were obtained in the UBV bandpasses. The data are compared with the results of a radiative transfer model calculating multiple scattering of interstellar field photons by dust grains with a single radius. The data show that the observed radial shape of the nebula, especially its half maximum radius, does not depend on wavelength (within experimental errors), suggesting that grains scatter in the grey regime, etc, etc (this abstract has been shortened)Comment: accepted by A

    RAC1-Dependent ORAI1 Translocation to the Leading Edge Supports Lamellipodia Formation and Directional Persistence

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    Tumor invasion requires efficient cell migration, which is achieved by the generation of persistent and polarized lamellipodia. The generation of lamellipodia is supported by actin dynamics at the leading edge where a complex of proteins known as the WAVE regulatory complex (WRC) promotes the required assembly of actin filaments to push the front of the cell ahead. By using an U2OS osteosarcoma cell line with high metastatic potential, proven by a xenotransplant in zebrafish larvae, we have studied the role of the plasma membrane Ca2+ channel ORAI1 in this process. We have found that epidermal growth factor (EGF) triggered an enrichment of ORAI1 at the leading edge, where colocalized with cortactin (CTTN) and other members of the WRC, such as CYFIP1 and ARP2/3. ORAI1-CTTN co-precipitation was sensitive to the inhibition of the small GTPase RAC1, an upstream activator of the WRC. RAC1 potentiated ORAI1 translocation to the leading edge, increasing the availability of surface ORAI1 and increasing the plasma membrane ruffling. The role of ORAI1 at the leading edge was studied in genetically engineered U2OS cells lacking ORAI1 expression that helped us to prove the key role of this Ca2+ channel on lamellipodia formation, lamellipodial persistence, and cell directness, which are required for tumor cell invasiveness in vivo.</p

    Ambient-pressure molecular superconductor with a superlattice containing layers of tris(oxalato)rhodate enantiomers and 18-crown-6

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    We report a novel multilayered organic-inorganic hybrid material, β”-(BEDT-TTF)2[(H2O)(NH4)2Rh(C2O4)3].18-crown-6. This is the first molecular superconductor to have a superlattice with layers of both BEDT-TTF and 18-crown-6, and also the first with the anion tris(oxalato)rhodate. This is the 2D superconductor with the widest gap between conducting layers where only a single donor packing motif is observed (β”). The strong 2D nature of this system strong-ly suggests that the superconducting transition is a KT transition. A superconducting Tc of 2.7 K at ambient pressure was found by transport and 2.5 K by magnetic susceptibility measurements

    Diarrhoea, acute respiratory infection, and fever among children in the Democratic Republic of Congo

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    Several years of war have created a humanitarian crisis in the Democratic Republic of Congo (DRC) with extensive disruption of civil society, the economy and provision of basic services including health care. Health policy and planning in the DRC are constrained by a lack of reliable and accessible population data. Thus there is currently a need for primary research to guide programme and policy development for reconstruction and to measure attainment of the Millennium Development Goals (MDGs). This study uses the 2001 Multiple Indicators Cluster Survey to disentangle children's health inequalities by mapping the impact of geographical distribution of childhood morbidity stemming from diarrhoea, acute respiratory infection, and fever. We observe a low prevalence of childhood diarrhoea, acute respiratory infection and fever in the western provinces (Kinshasa, Bas-Congo and Bandundu), and a relatively higher prevalence in the south-eastern provinces (Sud-Kivu and Katanga). However, each disease has a distinct geographical pattern of variation. Among covariate factors, child age had a significant association with disease prevalence. The risk of the three ailments increased in the first 8–10 months after birth, with a gradual improvement thereafter. The effects of socioeconomic factors vary according to the disease. Accounting for the effects of the geographical location, our analysis was able to explain a significant share of the pronounced residual geographical effects. Using large scale household survey data, we have produced for the first time spatial residual maps in the DRC and in so doing we have undertaken a comprehensive analysis of geographical variation at province level of childhood diarrhoea, acute respiratory infection, and fever prevalence. Understanding these complex relationships through disease prevalence maps can facilitate design of targeted intervention programs for reconstruction and achievement of the MDGs

    Monitoring degradation mechanisms in PTB7:PC71BM photovoltaic cells by means of impedance spectroscopy

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    © 2016. This version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/We have used impedance spectroscopy technique to monitor degradation mechanisms in organic solar cells based on a blend of PTB7:PC71BM. We have measured the impedance of the cell on a periodical basis for almost four months, and experimental data have been modeled using three different circuits. The evolution of the circuital parameters gives information about the device dynamical mechanisms. We have observed at high voltages a low frequency feature that is more pronounced along days of measurement. This low frequency arc has been associated to charge accumulation that is related to a worsening of charge extraction through the contacts. The simultaneous increase of recombination and low frequency resistances at high voltages (around V-oc) results in a decrease of the fill factor and therefore of the efficiency.Peer ReviewedPostprint (author's final draft

    A unified BFKL and GLAP description of F2F_2 data

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    We argue that the use of the universal unintegrated gluon distribution and the kTk_T (or high energy) factorization theorem provides the natural framework for describing observables at small x. We introduce a coupled pair of evolution equations for the unintegrated gluon distribution and the sea quark distribution which incorporate both the resummed leading ln(1/x)ln (1/x) BFKL contributions and the resummed leading ln(Q2)ln (Q^2) GLAP contributions. We solve these unified equations in the perturbative QCD domain using simple parametic forms of the nonperturbative part of the integrated distributions. With only two (physically motivated) input parameters we find that this kTk_T factorization approach gives an excellent description of the measurements of F2(x,Q2)F_2 (x,Q^2) at HERA. In this way the unified evolution equations allow us to determine the gluon and sea quark distributions and, moreover, to see the x domain where the resummed ln(1/x)ln (1/x) effects become significant. We use kTk_T factorization to predict the longitudinal structure function FL(x,Q2)F_L (x,Q^2) and the charm component of F2(x,Q2)F_2 (x,Q^2).Comment: 25 pages, LaTeX, 9 figure

    Elliptic and hyperelliptic magnetohydrodynamic equilibria

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    The present study is a continuation of a previous one on "hyperelliptic" axisymmetric equilibria started in [Tasso and Throumoulopoulos, Phys. Plasmas 5, 2378 (1998)]. Specifically, some equilibria with incompressible flow nonaligned with the magnetic field and restricted by appropriate side conditions like "isothermal" magnetic surfaces, "isodynamicity" or P + B^2/2 constant on magnetic surfaces are found to be reducible to elliptic integrals. The third class recovers recent equilibria found in [Schief, Phys. Plasmas 10, 2677 (2003)]. In contrast to field aligned flows, all solutions found here have nonzero toroidal magnetic field on and elliptic surfaces near the magnetic axis.Comment: 9 page
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