Developing a new methodology to characterize in vivo the passive mechanical behavior of abdominal wall on an animal model

The most common surgical repair of abdominal wall hernia goes through implanting a mesh that substitutes the abdominal muscle/fascia while it is healing. To reduce the risk of relapse or possible complications, this mesh needs to mimic the mechanical behavior of the muscle/fascia, which nowadays is not fully determined. The aim of this work is to develop a methodology to characterize in vivo the passive mechanical behavior of the abdominal wall. For that, New Zealand rabbits were subjected to pneumoperitoneum tests, taking the inner pressure from 0 mmHg to 12 mmHg, values similar to those used in human laparoscopies. Animals treated were divided into two groups: healthy and herniated animals with a surgical mesh (polypropylene SurgiproTM Covidien) previously implanted. All experiments were recorded by a stereo rig composed of two synchronized cameras. During the postprocessing of the images, several points over the abdominal surface were tracked and their coordinates extracted for different levels of internal pressure. Starting from that, a three dimensional model of the abdominal wall was reconstructed. Pressure–displacement curves, radii of curvature and strain fields were also analysed. During the experiments, animals tissue mostly deformed during the first levels of pressure, showing the noticeable hyperelastic passive behavior of abdominal muscles. Comparison between healthy and herniated specimen displayed a strong stiffening for herniated animals in the zone where the high density mesh was situated. Cameras were able to discern this change, so this method can be used to measure the possible effect of other meshes

Geología de las Mineralizaciones de Sulfuros Masivos en los cloritoesquistos de Moeche (Complejo de Cabo Ortegal, La Coruña.

En la Unidad de Moeche existen concentraciones sulfuradas cupríferas, poco documentadas y poco accesibles actualmente, que han sido explotadas por Cu hasta los años 1960. Se trata de menas metamórficas (metamorfizadas, pero no metamorfogénicas, según las evidencias observadas), diseminadas (en cloritoesquistos cuarzo-piríticos) o estratiformes (en niveles decimétricos a métricos). Las mineralizaciones están fuertemente laminadas y deformadas por la orogenia hercínica; su génesis es pre-tectónica, aunque las frecuentes movilizaciones parciales por transferencia en disolución, ligada a fenómenos de presión-disolución prácticamente ubicuos, enmascaran en parte los rasgos primarios. En cualquier caso, los cuerpos mineralizados muestran habitualmente una estructura concordante con la del encajante, si bien el conjunto está invertido en Mina Piquitos II, y fallado y muy deformada en Mina Barqueira. El encajante corresponde, esencialmente, a una serie meta-volcánica submarina (metabasitas representadas por cloritoesquistos, como tipo más frecuente), interpretada según las ideas actuales como el techo de una serie ofiolítica, con una fuerte impronta de metamorfismo dinámico y una mineralogía epizonal definida por proporciones variables de clorita, albita, actinolita (hornblenda), epidota/clinozoisita, esfena, anatasa, cuarzo, pirita y, en el entorno de Mina Maruxa, estilpnomelana y magnetita. La mineralogía de las menas diseminadas y de los niveles masivos es análoga y, en general, simple: pirita y calcopirita, con cantidades subordinadas a trazas de esfalerita, pirrotita, galena, magnetita, hematites, linneita, marcasita, oro nativo, etc. La Petrografía de IF (Inclusiones Fluidas) muestra que, debido a la fuerte impronta de metamorfismo dinámico, no se han preservado IF primarias (pre-metamórficas) medibles, sino sólo secundarias, sin-metamórficas, generalmente minúsculas y alojadas en microfisuras de tensión sobre microclastos y lentículas de cuarzo, o bien aisladas en cristales de cuarzo metamórfico. Los fluidos dominantes en estas IF son acuosos y densos (F~0,8), Lw, de salinidad moderada (~8% en peso NaCl equiv); no se ha constatado la presencia de CO2 y las temperaturas de homogeneización total oscilan entre 200 y 225ºC. Estos fluídos caracterizan el metamorfismo dinámico, en condiciones epizonales (Pf y T~2/2,5 kb y 325/350ºC, estimación preliminar). La información geoquímica obtenida, tanto por contenidos metálicos como por los valores isotópicos δ34S (-0,6 a +4,5‰, media +2,5‰), establece una clara afinidad con las concentraciones exhalativas o volcano-sedimentarias de sulfuros masivos (VMS), del tipo Cu-Zn de Lydon, análogas a las de Chipre (relacionadas con series ofiolíticas), lo que concuerda con la geología y mineralogía observadas, a pesar de la ubicua impronta metamórfica

Aberrations of spectrographs with the correction of the Schmidt camera effected in the collimator

Of the different ways to introduce the Schmidt correction of the camera in a spectrograph, the case was studies in which it is effected in the collimator. Equations which describe the form of the wavefront at one side of the grating as function of the form at the other side were found. The sixth order terms in the correction to compensate for the deformation of the wave front in the path from the collimator to the grating and to the mirror were also found. The aberrations for a correction which is symmetrical around* the collimator axis were calculated. The limit of camera aperture for which this aberrations are tolerable is between F/D = 4 and F/D = 3 according to the size and number of lines of the grating. Este trabajo será publicado en Óptica Acta.Asociación Argentina de Astronomí

The geometry of null rotation identifications

The geometry of flat spacetime modded out by a null rotation (boost+rotation) is analysed. When embedding this quotient spacetime in String/M-theory, it still preserves one half of the original supersymmetries. Its connection with the BTZ black hole, supersymmetric dilatonic waves and one possible resolution of its singularity in terms of nullbranes are also discussed.Comment: 1+18 pages, 5 figures. v2 references adde

A Fermi Surface Model for Large Supersymmetric AdS_5 Black Holes

We identify a large family of 1/16 BPS operators in N=4 SYM that qualitatively reproduce the relations between charge, angular momentum and entropy in regular supersymmetric AdS_5 black holes when the main contribution to their masses is given by their angular momentum.Comment: 32 pages, 6 figures, LaTeX uses JHEP3 class; ver 2- added acknowledgment, minor change

A Multi-Boundary AdS Orbifold and DLCQ Holography: A universal holographic description of extremal black hole horizons

We examine a stationary but non-static asymptotically AdS_3 spacetime with two causally connected conformal boundaries, each of which is a ``null cylinder'', namely a cylinder with a null direction identified. This spacetime arises from three different perspectives: (i) as a non-singular, causally regular orbifold of global AdS_3 by boosts, (ii) as a Penrose-like limit focusing on the horizon of extremal BTZ black holes, and (iii) as an S^1 fibration over AdS_2. Each of these perspectives sheds an interesting light on holography. Examination of the conformal boundary of the spacetime shows that the dual to the space should involve DLCQ limits of the D1-D5 conformal field theory. The Penrose-like limit approach leads to a similar conclusion, by isolating a sector of the complete D1-D5 CFT that describes the physics in the vicinity of the horizon of an extremal black hole. As such this is a holographic description of the universal horizon dynamics of the extremal black holes in AdS_3 and also of the four and five dimensional stringy black holes whose states were counted in string theory. The AdS_2 perspective draws a connection to a 0+1d quantum mechanical theory. Various dualities lead to a Matrix model description of the spacetime. Many interesting issues that are related to both de Sitter physics and attempts to ``see behind a horizon'' using AdS/CFT arise from (a) the presence of two disconnected components to the boundary, and (b) the analytic structure of bulk physics in the complex coordinate plane.Comment: 48 pages. 3 EPS figures. If you use mpage to print multiple postscript pages on the same sheet of paper you may have difficulties with the figures. The PDF version will print fine, as will postscript if you stick to one page per sheet. v3: minor edits and references adde

The R136 star cluster dissected with Hubble Space Telescope/STIS. II. Physical properties of the most massive stars in R136

We present an optical analysis of 55 members of R136, the central cluster in the Tarantula Nebula of the Large Magellanic Cloud. Our sample was observed with STIS aboard the Hubble Space Telescope, is complete down to about 40 M⊙, and includes 7 very massive stars with masses over 100 M⊙. We performed a spectroscopic analysis to derive their physical properties. Using evolutionary models we find that the initial mass function (IMF) of massive stars in R136 is suggestive of being top-heavy with a power-law exponent γ ≈ 2 ± 0.3, but steeper exponents cannot be excluded. The age of R136 lies between 1 and 2 Myr with a median age of around 1.6 Myr. Stars more luminous than log L/L⊙ = 6.3 are helium enriched and their evolution is dominated by mass loss, but rotational mixing or some other form of mixing could be still required to explain the helium composition at the surface. Stars more massive than 40 M⊙ have larger spectroscopic than evolutionary masses. The slope of the wind-luminosity relation assuming unclumped stellar winds is 2.41 ± 0.13 which is steeper than usually obtained (∼1.8). The ionising (log Q0 [ph/s] = 51.4) and mechanical (log LSW [erg/s] = 39.1) output of R136 is dominated by the most massive stars (>100 M⊙). R136 contributes around a quarter of the ionising flux and around a fifth of the mechanical feedback to the overall budget of the Tarantula Nebula. For a census of massive stars of the Tarantula Nebula region we combined our results with the VLT-FLAMES Tarantula Survey plus other spectroscopic studies. We observe a lack of evolved Wolf-Rayet stars and luminous blue and red supergiants

Are Comorbidities Associated With Overall Survival in Patients With Oral Squamous Cell Carcinoma?

Purpose: Oral squamous cell carcinoma (OSCC) is a highly prevalent type of immunogenic cancer with a low survival rate in patients with comorbidities owing to toxic habits. Materials and Methods: A retrospective cohort study was conducted of patients with resectable OSCC at a tertiary Spanish hospital from 2011 to 2014. The primary predictor variables were comorbidity and immune biomarkers. Comorbidity was assessed using the Adult Comorbidity Evaluation–27 (ACE-27) and scored from 1 to 3 (mild to severe decompensation, respectively). The immune biomarkers were neutrophil-to-lymphocyte ratio (NLR), derived NLR (dNLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR). The primary outcome variable was 5-year overall survival (OS). Other study variables were stage, margin, and neck management. Receiver operating characteristic curves were built for each ratio. For the survey of immune biomarkers, area under the curve was computed to determine cutoff points and investigate their association with OS. Kaplan-Meier estimates of survival and Cox proportional hazards models were used for longitudinal analysis. Results: Overall 215 patients were identified (median age, 67 yr; range, 32 to 96 yr; median follow-up, 31 months; range, 7 to 78 months); 159 patients had at least 1 comorbid condition. Results showed that a severe comorbidity (according to the ACE-27) increased the risk of death by 4 times in patients with OSCC regardless of stage. NLR, dNLR, LMR, and PLR were associated with OS in the univariate study. Cutoff points to predict increased mortality were 3, 1.9, 2.6, and 66 for NLR, dNLR, LMR, and PLR, respectively. Age, comorbidity, stage, margins, and management of the neck were important independent predictors of decreased OS in OSCC. PLR was marginally associated with OS in the multivariate model. Conclusion: These results suggest that comorbidity and NLR, dNLR, LMR, and PLR are associated with 5-year OS in patients with resectable OSCC

An experience beyond continuous assessment activities: virtual tour to the medieval medicinal plant garden of the Pedralbes monastery

El grupo de innovación docente integrado por profesores del área de Botánica (GIBAF) de la Universidad de Barcelona (UB) se plantea cada curso el diseño de nuevas actividades acreditativas en el marco de la evaluación continuada. Se presenta la experiencia llevada a cabo durante el curso 2008- 09 en la asignatura Botánica Farmacéutica. El objetivo ha sido implicar durante un semestre a los estudiantes en la autoría de un proyecto tutorizado de inmediata utilidad y clara perdurabilidad, más allá de su utilidad acreditativa. Como recurso se ha utilizado el Jardín de Plantas Medicinales del Monasterio de Pedralbes y se ha firmado un convenio de colaboración docente entre la UB y el Instituto de Cultura de Barcelona. Los estudiantes han realizado el trabajo utilizando la plataforma Moodle del Campus virtual de la UB en cinco etapas que han incluido la confección de unas fichas que se han ido modificando en función de las diversas retroacciones de los profesores. Al inicio de la actividad, se facilitó a los estudiantes el cronograma completo de la actividad, la pauta para su realización, así como un total de 18 recursos bibliográficos de uso obligado. Finalmente, a través de GoogleSites, se ha realizado una web que permite realizar un paseo virtual por el jardín, documentando de forma referenciada para las 50 plantas medicinales su nomenclatura, descripción botánica, distribución, usos (históricos, actuales y futuros) y toxicidad. El resultado de la actividad fue presentado en un acto público en el Monasterio de Pedralbes y puede consultarse en: http://sites.google.com/site/jardimedievalpedralbes/The group of teaching innovation in the area of Botany (GIBAF), University of Barcelona (UB), is raised each year to design new accreditation activities under continuous evaluation framework. We present the experience carried out during the academic year 2008-09 in the course of Pharmaceutical Botany. The aim has been to involve students for a semester in the authorship of a tutored project immediately useful and of easy permanence, beyond its assessment proving usefulness. The Medicinal Plants Garden of the Monastery of Pedralbes has been used as a resource and a collaboration agreement has been signed between the UB faculty and the Institute of Culture of Barcelona. The students have developed the work using the Moodle platform CampusvirtualUB into five stages which included preparation of files by students that have been modified in some steps following the various feedbacks from teachers. At the beginning of the activity, students were provided with a complete schedule of activities, the schedule for its implementation, and a total of 18 forced-use library resources. Finally, through Google sites, a website has been implemented, allowing for a virtual tour of the garden, documenting by referenced literature 50 medicinal plants for their nomenclature, botanical description, distribution, uses (historical, current and future) and toxicity. The result of the activity was presented at a public ceremony in the Monastery of Pedralbes and is available at: http://sites.google.com/site/jardimedievalpedralbes/Este trabajo ha sido parcialmente financiado con un Ajut per a Projectes d'Innovació Docent (2006PID-UB/11) de la Universidad de Barcelona

Estimation of the basal crop coefficient of a young almond orchard based on canopy cover and height

En los últimos años se está produciendo un crecimiento significativo de la superficie cultivada de almendros en zonas áridas y semiáridas de la cuenca Mediterránea con escasez de recursos hídricos. Este crecimiento está siendo exponencial en algunas zonas de España, como es el caso de Castilla‐La Mancha. Las principales razones han sido la mecanización de la recolección, un considerable incremento de la demanda global, que ha llevado a un aumento gradual del precio pagado al agricultor, y la introducción de nuevas variedades de floración tardía y extra‐tardía que reducen el riesgo de pérdidas de producción por heladas primaverales. Muchas de estas nuevas plantaciones se cultivan en condiciones de regadío, por lo que la determinación precisa de los coeficientes de cultivo es necesario para optimizar la programación del riego e incrementar la eficiencia en el uso del agua de este cultivo. El objetivo de este estudio fue estimar los valores del coeficiente de cultivo basal, Kcb, (componente transpirativa) para una plantación joven de almendros regados por goteo al 100% de sus necesidades hídricas y sin ningún otro tipo de estrés. Para ello, se utilizó la metodología propuesta por Allen&Pereira (2009), basada en medidas de la fracción de suelo cubierta por vegetación (fc) y la altura del cultivo (h). El experimento se llevó a cabo durante tres campañas consecutivas (2019‐2021) en una parcela comercial de 12,5 ha de almendros (Prunus dulcis (Mill.) D.A. Webb) localizada en Hellín (Albacete). Los árboles de la variedad ‘Penta’ se injertaron sobre el patrón GF‐677 en 2018. El marco de plantación fue de 6 m entre filas de árboles y 5 m entre plantas de la misma fila, dando lugar a 333 árboles ha‐1. Las medidas de fc y h se llevaron a cabo cada 15 días a lo largo de las tres campañas experimentales. Los valores directamente medidos de fc se convirtieron a valores de fracción de cobertura efectivos (fc eff) a partir del ángulo de inclinación del sol (β) cerca del mediodía solar. Los valores medios de fc eff durante la fase de mitad de temporada variaron entre 0,16 en 2019 y 0,38 en 2021, mientras que la altura media en esta fase osciló entre 2,36 m en 2019 y 3,45 m en 2021. Estos valores de fc eff y h dieron lugar a unos valores medios del coeficiente de cultivo basal en la fase de mediados de temporada (Kcb mid) de 0,30 en 2019, 0,45 en 2020 y 0,55 en 2021. Los valores de Kcb mid fueron ajustados a las condiciones climáticas templadas estándar (humedad relativa mínima del 45% y velocidad del viento de 2 m s‐1), lo que permite transferirlos a otras zonas con condiciones climáticas diferentes