8,963 research outputs found

    How do programs work to improve child nutrition?: Program impact pathways of three nongovernmental organization intervention projects in the Peruvian highlands

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    This paper examines the program logic of three nongovernmental, community-based programs with different intervention models to reduce childhood stunting. Two programs, Child Nutrition Program (PNI) and Good Start, focused directly on education and behavior change among caregivers, or the short routes to achieve impact, while one program, Sustainable Networks for Food Security (REDESA), focused on upstream factors, such as improving local governance and coordination, improving water and sanitation, and increasing family incomes, or the long routes to achieve impact. We compared the logic of each program as it was explicitly documented to the logic as perceived by the implementers. We elucidated the program impact pathways (PIPs) of key activities by actors at different operational levels in each program to identify congruencies and gaps in the perceptions of causal mechanisms between program activities and their intended outcomes, and analyzed them with the simple program models and logical frameworks to highlight the methodology and utility of PIPs. In a desire to move beyond static input-out models of the three programs, we designed and conducted data collection activities (document review, semi-structured interviews, and observations) with the intention of gaining insights about those aspects of the program that brought causal mechanisms of a given program into clearer focus. We propose that different methods for eliciting PIPs may be necessary at different operational levels. The interview method elicited more complete responses among those who are familiar with programmatic concepts, whereas actors at the local operational level provided sparse and fragmentary responses, even when simple, common language was used during the interviews. Group participatory processes, using visual aids, may be more effective for mapping the perceptions of those who are not accustomed to articulating information about programs. To reduce the length and frequency of interviews with program actors, initial PIPs could also be constructed from program documents, then discussed and revised iteratively with program actors. Although program logic models and the logical frameworks provide a succinct overview of the program (for communication, strategic planning, and management), we found that PIPs provide a better representation of the causal connections between program activities and results, particularly when both upstream and direct intervention activities were part of the same program. PIPs provide a visual tool for tracking how activities were perceived to work and make an impact, bringing into focus the different pathways of the activities and influences along the way. Beyond the logical sequence of program inputs, outputs, and outcomes, the conceptualization of impact pathways is a useful approach for understanding the causal connections required for impact and for identifying where attention and reinforcements may be required within program operation. The utility of this tool warrants its use not only during final evaluation but also during mid-program monitoring and relevant assessments. National- and regional-level program actors had good understanding of the overarching frameworks and principles of their respective programs as well as the program components and activities. They demonstrated a strong coherence to the program documents, provided similar cohesive responses, and were able to articulate the impact pathways. However, program actors at the national level identified fewer facilitators and barriers along the impact pathways than did the local actors, revealing that the practical dimensions of the impact pathways were not as evident to planners and managers farther from the communities. Although program actors at the local level were more apt to provide practical examples of influencing factors or incidents that occur during implementation, they had difficulty fully articulating their perceived PIPs and provided fragmented views of how the activities linked to their outcomes. Similar patterns were found across the three programs. This finding raises the question of desirability of a common understanding of the goals and pathways by which these outcomes are achieved or the acceptability of diversity of perspectives. It is still unclear whether program effectiveness may be improved through greater congruency in the PIPs. Future research should elucidate how congruency of PIPs among program actors across operational levels could be increased, and whether greater congruency would improve program implementation and effectiveness.program impact pathway, program logic model, logical framework, childhood stunting, child nutrition programs,

    Quantum order by disorder in frustrated diamond lattice antiferromagnets

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    We present a quantum theory of frustrated diamond lattice antiferromagnets. Considering quantum fluctuations as the predominant mechanism relieving spin frustration, we find a rich phase diagram comprising of six phases with coplanar spiral ordering in addition to the N\'eel phase. By computing the specific heat of these ordered phases, we obtain a remarkable agreement between (k,k,0)(k,k,0)-spiral ordering and the experimental specific heat data for the diamond lattice spinel compounds MnSc2_2S4_4, Co3_3O4_4 and CoRh2_2O4_4, i.e. specific heat data is a strong evidence for (k,k,0)(k,k,0)-spiral ordering in all of these materials. This prediction can be tested in future neutron scattering experiments on Co3_3O4_4 and CoRh2_2O4_4, and is consistent with existing neutron scattering data on MnSc2_2S4_4. Based on this agreement we infer a monotonically increasing relationship between frustration and the strength of quantum fluctuations.Comment: 4 pages, 2 figures, version published in PR

    Biaxial spin-nematic phase of two dimensional disordered rotor models and spin-one bosons in optical lattices

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    We show that the ground state of disordered rotor models with quadrupolar interactions can exhibit biaxial nematic ordering in the disorder-averaged sense. We present a mean-field analysis of the model and demonstrate that the biaxial phase is stable against small quantum fluctuations. We point out the possibility of experimental realization of such rotor models using ultracold spin-one Bose atoms in a spin-dependent and disordered optical lattice in the limit of a large number of atoms per site and also suggest an imaging experiment to detect the biaxial nematicity in such systems.Comment: revtex file 7 pages, 2 figures, version published in PR

    Selfduality for coupled Potts models on the triangular lattice

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    We present selfdual manifolds for coupled Potts models on the triangular lattice. We exploit two different techniques: duality followed by decimation, and mapping to a related loop model. The latter technique is found to be superior, and it allows to include three-spin couplings. Starting from three coupled models, such couplings are necessary for generating selfdual solutions. A numerical study of the case of two coupled models leads to the identification of novel critical points

    Proteomic analyses reveal misregulation of LIN28 expression and delayed timing of glial differentiation in human iPS cells with MECP2 loss-of-function.

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    Rett syndrome (RTT) is a pervasive developmental disorder caused by mutations in MECP2. Complete loss of MECP2 function in males causes congenital encephalopathy, neurodevelopmental arrest, and early lethality. Induced pluripotent stem cell (iPSC) lines from male patients harboring mutations in MECP2, along with control lines from their unaffected fathers, give us an opportunity to identify some of the earliest cellular and molecular changes associated with MECP2 loss-of-function (LOF). We differentiated iPSC-derived neural progenitor cells (NPCs) using retinoic acid (RA) and found that astrocyte differentiation is perturbed in iPSC lines derived from two different patients. Using highly stringent quantitative proteomic analyses, we found that LIN28, a gene important for cell fate regulation and developmental timing, is upregulated in mutant NPCs compared to WT controls. Overexpression of LIN28 protein in control NPCs suppressed astrocyte differentiation and reduced neuronal synapse density, whereas downregulation of LIN28 expression in mutant NPCs partially rescued this synaptic deficiency. These results indicate that the pathophysiology of RTT may be caused in part by misregulation of developmental timing in neural progenitors, and the subsequent consequences of this disruption on neuronal and glial differentiation

    What Is the Best Pain Control After Major Hepatopancreatobiliary Surgery?

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    In the modern era, hepato-pancreato-biliary (HPB) surgery has become safe with significant reductions in morbidity and mortality at high volume centers for both liver and pancreas surgery. While laparoscopic surgery has provided a safe approach with superior pain control laparotomy is still needed for the majority of HPB operations. Inadequate pain control is not only associated with poor patient experience but contributes to inferior outcomes. Specifically, inadequate pain control affects the neuroendocrine stress response, increases complication rates, and prolongs length of stay. Furthermore, there is an ongoing opioid epidemic and all fields of medicine should strive to reduce narcotic use to limit transformation into chronic opiate dependence. As such, successful pain control after HPB surgery continues to be a challenge and rigorous studies evaluating postoperative results are needed. The following article reviews the modalities debated to be the best strategies for pain control after major HPB surgery, as well as a discussion of other important considerations when executing these plans

    Asymptotic behavior of the density of states on a random lattice

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    We study the diffusion of a particle on a random lattice with fluctuating local connectivity of average value q. This model is a basic description of relaxation processes in random media with geometrical defects. We analyze here the asymptotic behavior of the eigenvalue distribution for the Laplacian operator. We found that the localized states outside the mobility band and observed by Biroli and Monasson (1999, J. Phys. A: Math. Gen. 32 L255), in a previous numerical analysis, are described by saddle point solutions that breaks the rotational symmetry of the main action in the real space. The density of states is characterized asymptotically by a series of peaks with periodicity 1/q.Comment: 11 pages, 2 figure

    Stabilities of nanohydrated thymine radical cations: insights from multiphoton ionization experiments and ab initio calculations

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    Multi-photon ionization experiments have been carried out on thymine-water clusters in the gas phase. Metastable H2O loss from T+(H2O)n was observed at n ≥ 3 only. Ab initio quantum-chemical calculations of a large range of optimized T+(H2O)n conformers have been performed up to n = 4, enabling binding energies of water to be derived. These decrease smoothly with n, consistent with the general trend of increasing metastable H2O loss in the experimental data. The lowest-energy conformers of T+(H2O)3 and T+(H2O)4 feature intermolecular bonding via charge-dipole interactions, in contrast with the purely hydrogen-bonded neutrals. We found no evidence for a closed hydration shell at n = 4, also contrasting with studies of neutral clusters
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