Total posterior leg open wound management with free anterolateral thigh flap: case and literature review.

Soft tissue coverage of the exposed Achilles tendon is a unique reconstructive challenge. In this report, we describe the management of a large posterior leg wound with exposed Achilles tendon using a free anterolateral thigh (ALT) flap. A careful review of alternative reconstructive options is included, along with their respective advantages and disadvantages. A 32-year-old white man suffered a fulminant right lower extremity soft tissue infection requiring extensive debridement of the entire posterior surface of the right leg. The resulting large soft tissue defect included exposure of the Achilles tendon. Reconstruction of the defect was achieved with an ALT flap and split-thickness skin graft for coverage of the Achilles tendon and gastrocnemius muscle, respectively. The patient was able to ambulate independently within 2 months of the procedure

Controlling vibrational cooling with Zero-Width Resonances: An adiabatic Floquet approach

In molecular photodissociation, some specific combinations of laser parameters (wavelength and intensity) lead to unexpected Zero-Width Resonances (ZWR), with in principle infinite lifetimes. Their interest in inducing basic quenching mechanisms have recently been devised in the laser control of vibrational cooling through filtration strategies [O. Atabek et al., Phys. Rev. A87, 031403(R) (2013)]. A full quantum adiabatic control theory based on the adiabatic Floquet Hamiltonian is developed to show how a laser pulse could be envelop-shaped and frequency-chirped so as to protect a given initial vibrational state against dissociation, taking advantage from its continuous transport on the corresponding ZWR, all along the pulse duration. As compared with previous control scenarios actually suffering from non-adiabatic contamination, drastically different and much more efficient filtration goals are achieved. A semiclassical analysis helps in finding and interpreting a complete map of ZWRs in the laser parameter plane. In addition, the choice of a given ZWR path, among the complete series identified by the semiclassical approach, amounts to be crucial for the cooling scheme, targeting a single vibrational state population left at the end of the pulse, while all others have almost completely decayed. The illustrative example, offering the potentiality to be transposed to other diatomics, is Na2 prepared by photoassociation in vibrationally hot but translationally and rotationally cold states.Comment: 15 pages, 14 figure

Extending fatigue life of aircraft fuselage structures using laser-peening

Fatigue of airframe structures is a constant challenge to aircraft manufacturers when designing, maintaining and repairing new and aging metallic components. Laser-Peening (LP) is a highly flexible and controllable surface treatment and relatively new to manufacturers of large civil aircraft which demonstrated that it can extend the fatigue and crack growth life in aluminium alloys by introducing deep compressive Residual Stresses (RS). Currently there is no application of LP to any components of large civil aircraft. The aim of this research was to demonstrate and explore different LP strategies that can produce significant extension of the fatigue and crack growth performance of aircraft fuselage structures using Laser-Peening. Two representative samples made from 2000 series aluminium alloy were designed to represent features of the fuselage: A Centre Cracked Tension (CCT) panel made of 1.6 mm thick 2524-T3 represented the fuselage skin. Single overlap Lap-Joints (LJ) of 2.5 mm thick 2024-T3 aluminium with titanium Hi-Lok bolts arrayed in 5 columns and 3 rows embodied longitudinal LJ of aircraft fuselages. Both test samples were laser-peened without protective coating (LPwC) using a range of LP strategies in which LP process parameters and spatial arrangements of laser-peened areas were systematically varied. RS fields were measured before fatigue testing under constant amplitude loading. RS measurements used Incremental Centre Hole Drilling (ICHD) and X-ray and Neutron diffraction techniques. Laser-peening produced peak compressive RS of 200 – 350 MPa and compression stress penetration depths between 700-1000 μm. These values are superior to RS profiles induced by Shot-Peening. The value of peak compression stress and penetration depth depends on LP process parameters and on the LP layout. The latter defines the location and size of the laser-peened areas. A study of the effect of different LP strategies to establish the most effective LP treatment to enhance crack growth life of fuselage skins was performed using a Finite Element based crack growth model. The model was first used to introduce balanced RS fields into a cracked CCT sample. The effective stress intensity factor range (ΔKeff) and effective R-ratios (Reff) were then calculated as the crack tip progressed through the sample. Subsequently, fatigue crack growth rates and lives were computed using Walker’s empirical crack growth law. The accuracy of the model was demonstrated by comparison with crack growth test results from laser-peened CCT-samples. Results of the parameter study showed that an increase in the level of compression within the LPS increased life most significantly. Increased width of peen stripe increased the life while increasing the distance of the stripe from the starting position of the crack tip decreased the life. Four different LP strategies were applied to LJ samples. Subsequent fatigue testing demonstrated fatigue life improvements of between 1.14 to 3.54, depending on the LP strategy. The LP layout was identified as a key parameter determining the fatigue life. It was found that when small LP areas were used, to leave as much elastic material as possible between the peened areas, larger compressive stresses and minimised balancing tensile stresses were produced. Observations of fatigue fractures on joint samples showed that crack initiation occurred remote from the fastener holes, either in regions of fretting fatigue in peened areas or in regions of balancing tensile stress adjacent to peen boundaries. Optimum fatigue lives occurred when both fracture types occurred in the same sample. Striation spacing measurement and analysis showed that compressive residual stresses had little or no effect on fatigue growth rates at crack lengths < 600 µm. The majority of fatigue life extension was achieved during initiation and crack growth < 600 μm. The obtained results established evidence of how aircraft fuselage structures made of conventional 2000 series aluminium-copper alloys can be effectively laser-peened to produced fatigue life improvements and also of how to avoid any detrimental reductions in fatigue life which can also occur when LP is applied randomly. The generated research conclusions are applicable to other metals, geometries and components

Teachers’ motivation and emotion during professional development : antecedents, concomitants, and consequences

Professional development (PD) opportunities are offered to teachers as means for them to develop their knowledge and teaching practices, with the hope of improved learning outcomes for students. However, PD experiences often do not improve teacher knowledge or lead to changed teacher practices. Research exploring how teachers interact with professional development can serve as a powerful tool and help to outline further the landscape of professional development. Specifically, understanding the intersections of motivation, emotion, and teacher learning may inform our understanding of why teachers do or do not implement what they learn in PD and contribute to theories about the motivation-emotion-learning connection. Theoretical frameworks influencing this work include Expectancy-Value theory of motivation (Eccles et al., 1983), with the idea that the theory may help with explaining teachers’ motivation during PD by way of teachers’ expectancies for successful implementation, value for implementing, and perceived costs of implementing influence their intentions to implement what they learned in PD. In addition to motivation, this study considers teachers’ emotional experiences during professional development. Emotion theories, as formulated by Pekrun (2006) and Fredrickson (2001), frame emotions as the product of cognitions, and emotions as antecedents to future cognition. In this way, emotions can support or hinder teachers’ learning during PD. As teaching is an emotionally laden profession (Hargreaves, 1998), the consequences of teachers’ emotions during PD are especially important to understand why and how teachers’ learn and implement professional development. In this descriptive study, I measured the antecedents and consequences of teachers’ motivational and emotional experiences during PD. Educator participants (n = 673) were sampled from 64 summer professional development experiences. Participants completed two questionnaires, one immediately following the summer PD experience and a second in the following fall semester. Data were analyzed using hierarchical linear modeling. Results indicated that participants’ motivation to implement what they had learned in PD and the degree to which they had experienced pleasant affect during PD predicted their intentions to implement what they had learned. Participants’ motivation to implement was also predicted by their teaching self-efficacy. Implications for research and practitioners are discussed.Educational Psycholog

Memorias TeSAC Santa Rita, Honduras 2019

La introducción del enfoque de los Territorios Sostenibles Adaptados al Clima (TeSAC) en Santa Rita ha permitido conformar una plataforma socialmente inclusiva en donde se ha generado evidencia sobre la adopción de prácticas de agricultura sostenible adaptada al clima (ASAC) y cuya consolidación ha sido posible gracias al fortalecimiento de las capacidades de los productores e instituciones locales por medio de talleres y capacitaciones enfocados en el uso de información agroclimática y la adopción de prácticas. Entre las instituciones más relevantes dentro del desarrollo del TeSAC en Santa Rita, resalta el rol de la Comisión de Acción Social Menonita (CASM) la cual hace presencia en la región y ha permitido la extensión de la metodología PICSA (Servicios Integrados Participativos de Clima para la Agricultura) entre productores agrícolas, integrando la información climática disponible a los procesos de toma de decisiones entre los productores agrícolas. Entre las principales practicas implementadas que se adaptan al contexto de Santa Rita y se espera puedan escalarse a otros contextos, se encuentran aquellas relacionadas con sistemas de recolección de agua para el riego como cosecha de agua, huertos con sistemas de recolección de agua y reservorios de agua, con 158 hogares implementándolas; así mismo, practicas orientadas a mejorar la calidad de los suelos mediante el uso de fertilizantes orgánicos, Kuxur rum, siembra en terrazas y manejo del café bajo sombra con podas sanitarias, han sido adoptadas por 177 hogares. De igual forma, se han logrado introducir otro tipo de prácticas como la construcción de huertos familiares (105 hogares), sistemas piscícolas (22 hogares), barreras vivas (6 hogares) y la siembra de frijol biofortificado (120 hogares). Por otro lado, se busca seguir trabajando en asegurar el financiamiento de los procesos de escalamiento del enfoque TeSAC a otras comunidades, así como el desarrollo de diversas investigaciones y la divulgación de la información recogida en los procesos realizados en el TeSAC.The introduction of the Climate Smart Villages (CSV) approach in Santa Rita has allowed the creation of a socially inclusive platform where evidence has been generated on the adoption of climate smart agriculture (CSA) practices and whose consolidation has been possible thanks to the strengthening of the capacities of local producers and institutions through workshops and training focused on the use of agroclimatic information and the adoption of practices. Among the most relevant institutions involved on the development of Santa Rita’s CSV, the Mennonite Social Action Commission (CASM) stands out, making presence in the region and allowing the scaling of the PICSA methodology among agricultural producers (Participatory Integrated Climate Services for Agriculture) integrating the climate information available to the decision-making processes among agricultural producers. Among the main practices implemented in Santa Rita’s context and expected to be scaled in other contexts, are those related to irrigation water collection systems such as water harvesting, orchards with water collection systems and reservoirs of water, with 158 homes implementing them; Likewise, practices focused on improving the quality of soils through the use of organic fertilizers, Kuxur rum, sowing on terraces and shade coffee control with sanitary pruning, have been adopted by 177 households. Similarly, other types of practices have been introduced such as the construction of family gardens (105 households), fish farming systems (22 households), living barriers (6 households) and the planting of biofortified beans (120 households). On the other hand, there are some advances ensuring the finance of the scaling processes of the CSV approach in other communities, as well as the development of various researches and the dissemination of the information collected in the processes carried out in the CSV

Mathematical Modelling of Transmission Dynamics of Anthrax in Human and Animal Population.

Anthrax is an infectious disease that can be categorised under zoonotic diseases. It is caused by the bacteria known as Bacillus anthraces. Anthrax is one of the most leading causes of deaths in domestic and wild animals. In this paper, we develop and investigated a mathematical model for the transmission dynamics of the disease. Ordinary differential equations were formulated from the mathematical model. We performed the quantitative and qualitative analysis of the model to explain the transmission dynamics of the anthrax disease. We analysed and determined the model’s steady states solutions. The disease-free equilibrium of the anthrax model is analysed for locally asymptotic stability and the associated epidemic basic reproduction number. The model’s disease free equilibrium has shown to be locally asymptotically stable when the basic reproductive number is less than unity. The model is found to exhibit the existence of multiple endemic equilibria. Sensitivity analysis was performed on the model’s parameters to investigate the most sensitive parameters in the dynamics of the diseases. Keywords: Anthrax model, Basic reproductive number, Asymptotic stability, Endemic equilibrium, Sensitivity analysis