Study of the lepton flavor-violating Z′→τμZ'\to\tau\mu decay

The lepton flavor violating $Z^{\prime}\to\tau\mu$ decay is studied in the context of several extended models that predict the existence of the new gauge boson named $Z^\prime$. A calculation of the strength of the lepton flavor violating $Z^\prime\mu\tau$ coupling is presented by using the most general renormalizable Lagrangian that includes lepton flavor violation. We used the experimental value of the muon magnetic dipole moment to bound this coupling, from which the $\mathrm{Re}(\Omega_{L\mu\tau}\Omega^\ast_{R\mu\tau})$ parameter is constrained and it is found that $\mathrm{Re}(\Omega_{L\mu\tau}\Omega^\ast_{R\mu\tau})\sim 10^{-2}$ for a $Z^\prime$ boson mass of 2 TeV. Alongside, we employed the experimental restrictions over the $\tau\to\mu\gamma$ and $\tau\to\mu\mu^+\mu^-$ processes in the context of several models that predict the existence of the $Z^\prime$ gauge boson to bound the mentioned coupling. The most restrictive bounds come from the calculation of the three-body decay. For this case, it was found that the most restrictive result is provided by a vector-like coupling, denoted as $|\Omega_{\mu\tau}|^2$, for the $Z_\chi$ case, finding around $10^{-2}$ for a $Z^\prime$ boson mass of 2 TeV. We used this information to estimate the branching ratio for the $Z^\prime\to\tau\mu$ decay. According to the analyzed models the least optimistic result is provided by the Sequential $Z$ model, which is of the order of $10^{-2}$ for a $Z^\prime$ boson mass around 2 TeV.Comment: Revised versio

A Hybrid Least Squares and Principal Component Analysis Algorithm for Raman Spectroscopy

Raman spectroscopy is a powerful technique for detecting and quantifying analytes in chemical mixtures. A critical part of Raman spectroscopy is the use of a computer algorithm to analyze the measured Raman spectra. The most commonly used algorithm is the classical least squares method, which is popular due to its speed and ease of implementation. However, it is sensitive to inaccuracies or variations in the reference spectra of the analytes (compounds of interest) and the background. Many algorithms, primarily multivariate calibration methods, have been proposed that increase robustness to such variations. In this study, we propose a novel method that improves robustness even further by explicitly modeling variations in both the background and analyte signals. More specifically, it extends the classical least squares model by allowing the declared reference spectra to vary in accordance with the principal components obtained from training sets of spectra measured in prior characterization experiments. The amount of variation allowed is constrained by the eigenvalues of this principal component analysis. We compare the novel algorithm to the least squares method with a low-order polynomial residual model, as well as a state-of-the-art hybrid linear analysis method. The latter is a multivariate calibration method designed specifically to improve robustness to background variability in cases where training spectra of the background, as well as the mean spectrum of the analyte, are available. We demonstrate the novel algorithm’s superior performance by comparing quantitative error metrics generated by each method. The experiments consider both simulated data and experimental data acquired from in vitro solutions of Raman-enhanced gold-silica nanoparticles

Global Forces of Change: Implications for Forest-poverty Dynamics

This article examines global trends likely to influence forests and tree-based systems and considers the poverty implications of these interactions. The trends, identified through a series of expert discussions and review of the literature, include: (i) climatic impacts mediated through changes in forests, (ii) growth in commodity markets, (iii) shifts in private and public forest sector financing, (iv) technological advances and rising interconnectivity, (v) global socio-political movements, and (vi) emerging infectious diseases. These trends bring opportunities and risks to the forest-reliant poor. A review of available evidence suggests that in a business-as-usual scenario, the cumulative risks posed by these global forces, in conjunction with limited rights, resources, and skills required to prosper from global changes, are likely to place poor and transient poor households under additional stress. The article concludes with an assessment of how interventions for enhancing forest management, combined with supportive policy and institutional conditions, can contribute to a different and more prosperous future for forests and people

Electric dipole and magnetic quadrupole moments of the WW boson via a CP-violating HWWHWW vertex in effective Lagrangians

The possibility of nonnegligible $W$ electric dipole ($\widetilde{\mu}_W$) and magnetic quadrupole ($\widetilde{Q}_W$) moments induced by the most general $HWW$ vertex is examined via the effective Lagrangian technique. It is assumed that new heavy fermions induce an anomalous CP-odd component of the $HWW$ vertex, which can be parametrized by an $SU_L(2)\times U_Y(1)$-invariant dimension-six operator. This anomalous contribution, when combined with the standard model CP-even contribution, lead to CP-odd electromagnetic properties of the $W$ boson, which are characterized by the form factors $\Delta \widetilde{\kappa}$ and $\Delta \widetilde{Q}$. It is found that $\Delta \widetilde{\kappa}$ is divergent, whereas $\Delta \widetilde{Q}$ is finite, which reflects the fact that the latter cannot be generated at the one-loop level in any renormalizable theory. Assuming reasonable values for the unknown parameters, we found that $\widetilde{\mu}_W\sim 3-6\times 10^{-21}$ e-cm, which is eight orders of magnitude larger than the SM prediction and close to the upper bound derived from the neutron electric dipole moment. The estimated size of the somewhat less-studied $\widetilde{Q}_W$ moment is of the order of $-10^{-36}$ e-cm^2, which is fifteen orders of magnitude above the SM contribution.Comment: 7 pages, 6 figures, REVTEX styl

EcoCyc: fusing model organism databases with systems biology.

EcoCyc (http://EcoCyc.org) is a model organism database built on the genome sequence of Escherichia coli K-12 MG1655. Expert manual curation of the functions of individual E. coli gene products in EcoCyc has been based on information found in the experimental literature for E. coli K-12-derived strains. Updates to EcoCyc content continue to improve the comprehensive picture of E. coli biology. The utility of EcoCyc is enhanced by new tools available on the EcoCyc web site, and the development of EcoCyc as a teaching tool is increasing the impact of the knowledge collected in EcoCyc

Indigenous Peoples’ Perceptions of Their Food System in the Context of Climate Change: A Case Study of Shawi Men in the Peruvian Amazon

Biodiversity and ecosystem conservation in the Amazon play a critical role in climate-change mitigation. However, institutional responses have had conflicted and complex relations with Indigenous peoples. There is a growing need for meaningful engagement with—and recognition of—the centrality of Indigenous peoples’ perceptions and understanding of the changes they are experiencing to inform successful and effective place-based adaptation strategies. To fill this gap, this study focuses on the value-based perspectives and pragmatic decision-making of Shawi Indigenous men in the Peruvian Amazon. We are specifically interested in their perceptions of how their food system is changing, why it is changing, its consequences, and how/whether they are coping with and responding to this change. Our results highlight that Shawi men’s agency and conscious envisioning of their future food system intersect with the effects of government policy. Shawi men perceive that the main driver of their food-system changes, i.e., less forest food, is self-driven population growth, leading to emotions of guilt and shame. During our study, they articulated a conscious belief that future generations must transition from forest-based to agricultural foods, emphasising education as central to this transition. Additionally, results suggest that the Peruvian government is indirectly promoting Shawi population growth through policies linking population size to improved service delivery, particularly education. Despite intentional Shawi moves to transition to agriculture, this results in a loss of men’s cultural identity and has mental-health implications, creating new vulnerabilities due to increasing climatic extremes, such as flooding and higher temperatures

Partial transplantation of trachea with preservation of vascular supply: experimental study with and without immunosuppression in animal models

Introducción. La intubación traqueal prolongada puede causar estenosis. En lesiones extensas, se han realizado trasplantes o colocación de prótesis sin buenos resultados. El trasplante evoluciona frecuentemente con necrosis, retraso de la cicatrización, estenosis e isquemia. En este trabajo se realizó el trasplante de un segmento anterior de la pared traqueal, para preservar el suministro vascular del tejido que permita ampliar la luz traqueal y supere los problemas derivados del trasplante completo o de la inserción de prótesis. Objetivo. Evaluar la viabilidad, los cambios histológicos macroscópicos y microscópicos en trasplante alógénico de un parche anterior de tráquea, en dos grupos de conejos, con y sin inmunosupresión. Métodos. Estudio experimental, prospectivo, randomizado y controlado. Se utilizaron 15 conejos de cepas exocriadas. En 5 se realizó autotrasplante para estandarizar la técnica quirúrgica. En 10 se realizó alotrasplante de la pared anterior de la tráquea, a 5 de los cuales se les administró ciclosporina. Se hizo la eutanasia al día 15 del postoperatorio, para estudio macro y microscópico. Resultados. Todos los conejos evolucionaron satisfactoriamente. No hubo diferencia significativa entre los que recibieron inmunosupresión y los que no la recibieron, cuando se evaluó la pérdida del epitelio, tejido de granulación, infiltración linfocitaria y fibroproliferación. Sí hubo oclusión luminal debido a causas inflamatorias. Al evaluar hialinosis vascular, estrechez vascular, endotelitis y linfangiectasias no hubo diferencia significativa, ninguno presentó necrosis tisular. Se encontraron numerosos capilares permeables en el segmento trasplantado y conservación del epitelio. Conclusiones. El trasplante segmentario de pared anterior de tráquea permitió ampliar la luz traqueal con preservación vascular del injerto y buena viabilidad, macro y microscópica. La evolución postquirúrgica fue buena en ambos grupos.Introduction. Prolonged tracheal intubation can cause stenosis. In extensive lesions, they have performed transplants or prosthesis placement without good results. Transplantation frequently evolves with necrosis, delayed healing, and ischemia. The anterior segment of the tracheal wall was transplanted to preserve the vascular supply of the trachea. Objectives. Verify that the transplant of a previous patch of the trachea, allows to expand the tracheal lumen in its anterior part and overcome the problems derived from the complete transplant or the insertion of prosthesis and evaluate the viability, macroscopic and microscopic changes of the transplant in two groups of rabbits, one of which will receive treatment with immunosuppressants. Methods. Experimental, prospective, randomized and controlled study. We used 15 rabbits of exocriated strains. In 5, autotransplantation was performed to standardize the surgical technique. In 10, an alotransplant of the anterior wall of the trachea was performed, 5 of which were administered ciclosporin. Euthanasia was performed 15 days postoperatively, for macro and microscopic study. Results. All rabbits evolved satisfactorily. There was no significant difference between those who received immunosuppression and those who did not receive it, when loss of epithelium, granulation tissue, lymphocyte infiltration and fibroproliferation was evaluated. If there was luminal occlusion due to inflammatory causes. When evaluating vascular hyalinosis, vascular stricture, endothelitis and lymphangiectasis there was no significant difference. In none was tissue necrosis found. There were numerous permeable capillaries in the transplanted segment and conservation of the epithelium. Conclusions. The segmental transplantation of the anterior wall of the trachea allowed to enlarge the tracheal lumen with vascular preservation of the graft and good viability, macro and microscopic. Postoperative evolution was good in both groups