Inverse mass matrix via the method of localized lagrange multipliers

An efficient method for generating the mass matrix inverse is presented, which can be tailored to improve the accuracy of target frequency ranges and/or wave contents. The present method bypasses the use of biorthogonal construction of a kernel inverse mass matrix that requires special procedures for boundary conditions and free edges or surfaces, and constructs the free-free inverse mass matrix employing the standard FEM procedure. The various boundary conditions are realized by the method of localized Lagrange multipliers. Numerical experiments with the proposed inverse mass matrix method are carried out to validate the effectiveness proposed technique when applied to vibration analysis of bars and beams. A perfect agreement is found between the exact inverse of the mass matrix and its direct inverse computed through biorthogonal basis functions

O cuidado na Atenção Primária à Saúde: a vivência de enfermeiras

Indexación: Scopus; Scielo.Objetivo: comprender el signifi cado de realizar cuidados de enfermería en la Atención Primaria de Salud desde la perspectiva de las enfermeras chilenas. Método: investigación cualitativa con enfoque desde la fenomenología social de Alfred Schütz. La recolección de datos fue realizada entre enero y abril del 2013, a través de entrevista con 13 enfermeras de Atención Primaria en Chile. Resultados: las enfermeras perciben el cuidado como una experiencia gratifi cante considerando un encuentro de subjetividades. Sin embargo, se sienten sobrecargadas por múltiples funciones a realizar y por presiones jerárquicas en el logro de las metas. Aspiran implementar cuidados innovadores manifi estados por el deseo de superar el cuidado tradicional y la efi ciencia de la gestión de los diversos niveles de atención de la salud. Conclusión: es importante discutir estos resultados en el contexto de la asistencia y especialmente en la formación, con el fi n de preparar mejor a las enfermeras que brindarán cuidados en este nivel de atención.OBJECTIVE: to understand the meaning of nursing care in primary health care from the perspective of Chilean nurses. METHOD: this was a qualitative study based on the social phenomenology of Alfred Schutz. Data was collected between January and April 2013, through interviews with 13 primary health care nurses in Chile. RESULTS: the nurses perceived primary care as a gratifying experience, considering it an encounter of subjectivities. However, they felt burdened with multiple functions and by the hierarchical pressure to achieve targets. They strived to implement innovative care, expressed by the desire to go beyond traditional care practices, and improve the efficiency of management at the various levels of health care. CONCLUSION: it is important to discuss the results of the present study in the context of health care and especially nursing education, with the goal of better preparing nurses who will deliver care at the primary health care level.Objetivo: compreender o signifi cado atribuído aos cuidados de enfermagem na Atenção Básica de Saúde por enfermeiras chilenas. Método: pesquisa qualitativa baseada na fenomenologia social de Alfred Schutz. Os dados foram coletados entre janeiro e abril de 2013, por meio de entrevistas com 13 enfermeiras de unidades de Atenção Básica em uma cidade do Chile. Resultados: as enfermeiras percebem o cuidado prestado como uma experiência gratifi cante, considerando-o um encontro de subjetividades. No entanto, elas se sentem sobrecarregadas pelas múltiplas funções que realizam e pelas pressões hierárquicas para cumprir metas. Elas se esforçam para implementar cuidados inovadores que possam superar o cuidado tradicional e aumentar a efi ciência da gestão nos vários níveis de atenção à saúde. Conclusão: é importante discutir estes resultados no contexto da assistência e especialmente na formação, com o objetivo de melhorar a preparação de enfermeiros trabalhando nesse nível de atenção.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0034-71672018000700531&lng=en&tlng=e

Underlying SUSY in a generalized Jaynes–Cummings model

We present a general qubit-boson interaction Hamiltonian that describes the Jaynes–Cummings model and its extensions as a single Hamiltonian class. Our model includes non-linear processes for both the free qubit and boson field as well as non-linear, multi-boson excitation exchange between them. It shows an underlying algebra with supersymmetric quantum mechanics features allowing an operator based diagonalization that simplifies the calculations of observables. As a practical example, we show the evolution of the population inversion and the boson quadratures for an initial state consisting of the qubit in the ground state interacting with a coherent field for a selection of cases covering the standard Jaynes–Cummings model and some of its extensions including Stark shift, Kerr-like, intensity dependent coupling, multi-boson exchange and algebraic deformations

USO DE COBERTURAS Y MALLA SOMBRA PARA PRODUCCIÓN DE Vanilla planifolia Jacks. ex Andrews

La producción tradicional de vainilla (Vanilla planifolia Jacks. ex Andrews) en México se lleva a cabo utilizando la sombra de tutores de colorín(Erythrina americana), guácima (Guazuma ulmifolia), chaca (Bursera simaruba), ciruela mexicana (Spondia sp.), entre otros, en asociación con arvenses de la zona, lo que ocasiona la presencia de enfermedades causadas por Fusarium, Phytophthora, Colletotricum y otros organismos, que aunadas a bajas densidades de plantación, ocasionan bajos rendimientos provocando el abandono del cultivo

PROPIEDADES AGROPRODUCTIVAS DE Ricinus communis L. Y CARACTERIZACIÓN FISICOQUÍMICA DEL ACEITE

Agroproductive properties from seven accessions of R. communis L., and physical-chemical characteristics of their oil as raw matter for biodiesel, were determined. The accession SF6 had a greater number of racemes (34), number of capsules (1453), weight of the capsule per plant (1324 g), skin (69 %) and oil (48 %), but smaller size of the seed (6.8 mm of mean geometric diameter). The seeds from accession C were larger (74 g and 95 mL for 100 seeds); however, it had lower seed yield (326 g per plant). Accessions Mir and SF7 obtained the highest capsule weight per plant (1518 and 1595 g), seed (49%), seed yield (742 and 796 g) and estimated seed yield (808 and 867 kg ha-1). In terms of physical-chemical characteristics of the castor oil, the accessions C, SF7 and M2 were within the quality standards; however, SF7 (from sites contaminated with mining residues) stood out because of its high estimated oil production (362 kg ha-1), showing adequate physical-chemical properties for biodiesel production: relative density (0.96 g mL-1), viscosity (410.7 cSt); refraction (1.47), iodine (83.5 g I2 100 g-1) and saponification (184.1 mg g-1) indexes; which make it advisable for biodiesel productionSe determinaron propiedades agroproductivas de siete accesiones de Ricinus communis L. y características fisicoquímicas de su aceite como materia prima de biodiesel. La accesión SF6 tuvo mayor número de racimos (34), número de cápsulas (1453), peso de cápsula por planta (1324 g), cáscara (69%) y aceite (48%) pero menor tamaño de semilla (6.8 mm de diámetro medio geométrico). Las semillas de la accesión C fueron de tamaño mayor (74 g y 95 mL por 100 semillas), sin embargo, tuvo menor rendimiento de semilla (326 g por planta). Las accesiones Mir y SF7 obtuvieron el mayor peso de cápsulas por planta (1518 y 1595 g), semilla (49%), rendimiento de semilla (742 y 796 g) y rendimiento estimado de semilla (808 y 867 kg ha-1). En cuanto a características fisicoquímicas del aceite de ricino las accesiones de C, SF7 y M2 estuvieron dentro de los estándares de calidad, sin embargo, la SF7 (proveniente de sitios contaminados con residuos de minería) destacó por su elevada producción estimada de aceite (362 kg ha-1); registrando propiedades fisicoquímicas adecuadas para producción de biodiesel: densidad relativa (0.96 g mL-1), viscosidad (410.7 cSt), índices de refracción (1.47), de yodo (83.5 g I2 100 g-1) y de saponificación (184.1 mg g-1), que hacen recomendable su producción para biodiesel

Inverse mass matrix via the method of localized Lagrange multipliers

An efficient method for generating the mass matrix inverse of structural dynamic problems is presented, which can be tailored to improve the accuracy of target frequency ranges and/or wave contents. The present method bypasses the use of biorthogonal construction of a kernel inverse mass matrix that requires special procedures for boundary conditions and free edges or surfaces and constructs the free-free inverse mass matrix using the standard FEM procedure. The various boundary conditions are realized by the the method of localized Lagrange multipliers. In particular, the present paper constructs the kernel inverse matrix by using the standard FEM elemental mass matrices. It is shown that the accuracy of the present inverse mass matrix is almost identical to that of a conventional consistent mass matrix or a combination of lumped and consistent mass matrices. Numerical experiments with the proposed inverse mass matrix are conducted to validate its effectiveness when applied to vibration analysis of bars, beams, and plain stress problems.Centre of Excellence for nonlinear dynamic behavior of advanced materialsin engineering CZ.02.1.01/0.0/0.0/15 003/000049

Abordaje transvasto mínimamente invasivo versus abordaje parapatelar medial convencional en la artroplastia total de rodilla en pacientes con gonartrosis: estudio prospectivo comparativo no randomizado

Objetivos: valorar y comparar los resultados a corto plazo de la artroplastia total de rodilla realizada mediante dos vías de abordaje. Material y métodos: estudio prospectivo comparativo que compara abordaje parapatelar medial (24 pacientes) y transvasto mínimamente invasivo (25 pacientes) en artroplastia total de rodilla. Se incluyeron pacientes con gonartrosis grado IV de la clasificación de Kellgren-Lawrence y se excluyeron aquellos menores de 50 años, deformidad en varo (> 15º) o valgo (> 10º), artrosis postraumática, artritis reumatoide, cirugías de revisión, osteotomías correctoras previas, IMC > 40 kg/m2, infección activa local o sistémica y/o deterioro mental. Resultados: se encontraron diferencias estadísticamente significativas en dolor del primer y segundo día postoperatorios a favor del abordaje mínimamente invasivo (1º día: 3,8 ± 2,5 vs. 6,7 ± 2,1; p< 0,001. 2º día: 3 ± 2,1 vs. 6 ± 2; p< 0,001). Conclusiones: no existen diferencias relevantes entre ambos abordajes, por lo que se recomienda la utilización del abordaje con el que el cirujano se encuentre más cómodo y familiarizadoAim: Assess and compare short-term outcomes of total knee arthroplasty performed using two surgical approaches. Material and methods: a prospective study with 49 patients comparing medial parapatellar approach (24 patients) and minimally invasive trans-vastus access (25 patients) in total knee replacement. The patients included suffered knee osteoarthritis grade IV the Kellgren-Lawrence’s classification. Exclusion criteria were age under 50 years, large axial deformity (varus deformity > 15° or valgus > 10°), posttraumatic osteoarthritis, rheumatoid arthritis, revision surgeries, previous osteotomies, BMI> 40 kg/m2 and of course local or systemic active infection and mental impairment. Results: statistically significant differences were found for pain in first and second postoperative days for the minimally invasive approach (1st day: 3.8 ± 2.5 vs. 6.7 ± 2.1; p <0.001. 2nd day: 3 ± 2.1 vs. 6 ± 2; p <0.001). Conclusions: there are not significant differences between mini and standard approaches in knee replacement, so decision about which access to use in knee reconstruction surgery depends on surgeon’s preferences

Symmetry breaking from Scherk-Schwarz compactification

We analyze the classical stable configurations of an extra-dimensional gauge theory, in which the extra dimensions are compactified on a torus. Depending on the particular choice of gauge group and the number of extra dimensions, the classical vacua compatible with four-dimensional Poincar\'e invariance and zero instanton number may have zero energy. For SU(N) on a two-dimensional torus, we find and catalogue all possible degenerate zero-energy stable configurations in terms of continuous or discrete parameters, for the case of trivial or non-trivial 't Hooft non-abelian flux, respectively. We then describe the residual symmetries of each vacua.Comment: 24 pages, 1 figure, Section 4 modifie

Amputación Pirogoff modificada aplicada a la cirugía oncológica del pie

Los sarcomas óseos y de tejidos blandos del pie son infrecuentes, representando menos del 10% de todos los sarcomas de la extremidad inferior. El tratamiento más frecuente de los sarcomas del pie es la amputación por debajo de la rodilla, debido a la imposibilidad de conseguir márgenes amplios, pero en determinados casos de tumores del antepié se puede optar por una amputación parcial del pie con margen amplio. Se presenta una serie de tres casos de amputación de Pirogoff modificada aplicada a la resección oncológica tumoral. La amputación de Pirogoff consiste en una artrodesis calcaneotibial con resección del astrágalo, rotando el calcáneo 90°. La modificación de la técnica de amputación del Pirogoff, en la que se conservan ambos maléolos con escisión de la carilla articular favorece la estabilidad en el plano lateral y ayuda a una más rápida artrodesis. Es muy importante mantener los principios oncológicos de la resección tumoral.Bone and soft-tissue sarcomata of the foot are infrequent neoplasms, representing less than 10% of all lower limb sarcomata. The most frequent therapeutic measure for foot sarcomata is amputation below the knee, due to the difficulty to achieve ample (onco-)-surgical margins, yet in a number of cases of forefoottumours there is an option for partial foot amputation with ample surgical margins. We report a series of three cases of modified Pirogoff's amputation as applied to oncosurgical tumour resection. Pirogoff's amputation is a calcaneo-tibial arthrodesis with resection of the talus and 90° rotation of the calcaneus. The here reported modification of the Pirogoff amputation, in which both malleoli are preserved yet with excision of the articular surface, favours lateral-plane stability and promotes a quicker arthrodesis. It is highly important to observe and maintain the oncologic surgery principles for tumour resection