Transition prediction in incompressible boundary layer with finite-amplitude streaks

Modulating the boundary layer velocity profile is a very promising strategy for achieving transition delay, and thus reducing the friction of the plate. An usual way to perform it is by perturbing the flow with counter-rotating vortices that exhibit transient, non-modal growth and lead to streamwise aligned streaks inside the boundary layer, which have been proved (theoretical and experimentally) to be very robust flow structures. Recently, a new mechanism of generating high amplitude streaks has been proposed, consisting on miniature vortex generators (MVGs), increasing considerably the potential stabilization effect. Hence, we propose a numerical tool to analyze the stability properties of the streaky flow without big computational resources. Since streaks depend on how they are generated, and it is linked to the geometric configuration of the surface, a cheap CPU numerical analysis is required in order to perform large parametric studies for streak optimization. For this end, we use the reduced Navier-Stokes (RNS) equations to simulate the nonlinear downstream evolution of finite amplitude streaks in incompressible boundary layer flow. Regarding the stability analysis, the linear three-dimensional Parabolized Stability Equations (PSE-3D) concept constitutes the best candidate for this task. Herein, we present a thorough parametric study of the instability characteristic with respect to critical conditions of the modified incompressible zero-pressure-gradient flat-plate boundary layer by means of finite-amplitude linearly optimal disturbances or streaks. The parameter space is extended from low- to high- amplitude streaks, accurately documenting the transition delay for low-amplitude streaks and the amplitude threshold for streak shear layer instability or bypass transition, which drastically displaces the transition front upstream

A polytrauma patient with an unusual posterior fracture-dislocation of the femoral head: a case report

We report a case of a 27-year-old man who was involved in a high-speed car accident. He sustained multiple organ damage including multiple brain petechiae suggesting diffuse axonal damage, aortic dissection, retroperitoneal haematoma and a fracture-dislocation of the right hip with a femoral head fracture and an ipsilateral intertrochanteric fracture. Due to the general condition of the patient, physiological stabilisation was prioritized, and at 2 weeks the fracture-dislocation of the hip was treated with a proximal femoral nail for the intertrochanteric fracture and Herbert screws for the femoral head fracture. Postoperatively, two episodes of recurrent hip dislocation occurred, and this was stabilized eventually with a Steinman pin inserted across the hip joint and taken out 1 month later. Weight-bearing was allowed according to clinical and radiographical assessments. Heterotopic ossification developed around the hip joint, but without evidence of AVN or osteoarthritis. At 18-months follow-up, the fractures had healed and the patient had a Harris Hip score of 79.1. Anatomical reduction and stable fixation of fracture-dislocations of the hip are important for achieving an acceptable result

Currency hedging strategies, strategic benchmarks and the Global and Euro Sovereign financial crises

This paper investigates dynamic currency hedging benefits, with a further focus on the impact of currency hedging before and during the recent financial crises originated from the subprime and the Euro sovereign bonds. We take the point of view of a Euro-based institutional investor who considers passive investment strategies in portfolios holding European, British and US assets. We analyze the impact of the model specification to improve the risk-return tradeoff when currency risk is hedged. Hedging strategies of currency risk, using exchange rates futures and driven by several multivariate GARCH models, depend on the portfolio composition and period analyzed. Dynamic covariance models provide limited evidences of a decrease in hedging rations compared to naïve hedging strategies based on linear regressions or variance smoothing. Nevertheless, those results are coupled with better performances of dynamic covariance models in terms of hedging effectiveness an improved Sharpe ratios. The empirical evidences are observed both in-sample as well as in an out-of-sample exercise

Sequía, viento y tormentas de polvo 2021-22 en Patagones

Luego de transcurrido diez meses de la sequía 2021, las lluvias de noviembre promovieron el laboreo mecánico de los suelos de Patagones para la siembra de verdeos de verano. Debida a la alta demanda hídrica de la atmósfera, solo unos pocos verdeos fueron logrados sin pérdidas de suelos. La condición de fuertes vientos hizo que los suelos que quedaron desnudos fueran sujetos a grandes voladuras.EEA Hilario AscasubiFil: Cantamutto, Miguel Angel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; Argentina.Fil: Colazo, Juan Cruz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Luis; ArgentinaFil: Rodriguez, Emiliano. Actividad privada; ArgentinaFil: Gonzalez, Guillermo Martin. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi. Agencia De Extensión Rural Carmen de Patagones; Argentin

Numerical studies of non-linear intrinsic streaks in the flat plate boundary layer

The development of streaky perturbations near the leading edge of a flat plate boundary layer was analyzed by Luchini (1996) using a description of the flow linearized around the Blaius solution. He found that there is just one single streaky mode (periodic in the spanwise direction) that grows downstream from the leading edge. The presence of this mode in the linear approximation indicates that, for the complete non-linear problem, there is an one parameter family of streak solutions that grow from the leading edge of the boundary layer. This family of steady 3D non-linear intrinsic streaks (intrinsic because they appear in the complete absence of any free stream perturbation) was recently non-linearly computed, using the Reduced Navier-Stokes formulation to describe its downstream evolution far away from the linear region. In this work, we enlarge the analysis of the transversal structure of the streaks. Furthermore, the stability characteristics of the streaky boundary layer flow is presented using the three-dimensional Parabolized Stability Equations (PSE-3D) and spatial BiGlobal analysis formulations, which have been successfully employed in flows that are inhomogeneous in two directions and weakly dependent along the third spatial direction. The stability analysis results show that the intrinsic streaks damp Tollmien-Schlichting waves. This effect is increased as the amplitude of the streak grows. At a certain limit, as observed in linear optimal streaks, shear-layer modes become unstable, potentially producing bypass transition

Servicios de la ACOOPA en apoyo al sector agropecuario regional 2022-2023

La Asociación Cooperadora de la Estación Experimental Agropecuaria Hilario Ascasubi (ACOOPA) es una organización sin fines de lucro que apoya las actividades de investigación y extensión del Instituto Nacional de Tecnología Agropecuaria (INTA) en el extremo austral bonaerense. Los servicios ofrecidos a los productores, instituciones y otros comitentes, incluyen la clasificación y análisis de semillas, análisis de suelos y forestación con salicáceas. Entre julio de 2022 y junio de 2023, a través de la Planta de Limpieza y Clasificación de Semillas, se procesaron más de medio millón de kg de semillas. A través de los laboratorios se realizó el control de calidad de 260 muestras de semillas de varias especies de valor agronómico, y se analizaron cerca de un millar de muestras de suelos y agua. Los servicios tuvieron como destino directo a los productores o resultaron como apoyo a actividades de investigación y extensión de INTA. El servicio de forestación con salicáceas bajo el sistema de plantación profunda, con la entrega de unos 1.200 nuevos individuos, continuó fortaleciendo la adopción de la innovadora tecnología. Se estima que, en conjunto, los servicios realizados mejoraron el manejo de los suelos en cerca de 30 mil ha. La certificación de la calidad de las semillas benefició a unas 90 mil ha de cultivos, principalmente forrajeras perennes y cultivos de servicio. La mejora de la calidad física y botánica de las partidas de semillas presentes en el Valle posibilitó optimizar la siembra de unas 20 mil ha de cultivos. También en este caso existió una fuerte predominancia de semillas de pasturas y leguminosas forrajeras.EEA Hilario AscasubiFil: Cantamutto, Miguel Angel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; Argentina.Fil: Renzi Pugni, Juan Pablo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; ArgentinaFil: Iurman, Daniel Eduardo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; Argentina.Fil: Fernández, Marianela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; Argentina.Fil: Urrutia, Gustavo Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi; Argentina.Fil: Gonzalez, Guillermo Martin. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Hilario Ascasubi. Agencia De Extensión Rural Carmen de Patagones; Argentin

Metallofluorescent Nanoparticles for Multimodal Applications

Herein, we describe the synthesis and application of cross-linked polystyrene-based dual-function nano- and microparticles containing both fluorescent tags and metals. Despite containing a single dye, these particles exhibit a characteristic dual-band fluorescence emission. Moreover, these particles can be combined with different metal ions to obtain hybrid metallofluorescent particles. We demonstrate that these particles are easily nanofected into living cells, allowing them to be used for effective fingerprinting in multimodal fluorescence-based and mass spectrometry-based flow cytometry experiments. Likewise, the in situ reductions of the metal ions enable other potential uses of the particles as heterogeneous catalysts

Description of the vaginal microbiota in nulliparous ewes during natural mating and pregnancy: preliminary signs of the male preputial microbiota modulation

The vaginal microbiota plays a key role in animals' health. Understanding its diversity and composition and associated changes occurring through the reproductive cycle represents valuable knowledge to disclose the mechanisms leading to dysbiosis and eventually to infection. Even if the human vaginal microbiota has been thoroughly studied, scarce research has been conducted on the vaginal microbiota of livestock. In this study, 16S rRNA gene-based sequencing was performed on vaginal samples of ten nulliparous ewes at three different sampling points: before the estrus synchronization protocol (T0), at the time of estrus before mating (Testrus), and the day of the pregnancy diagnosis (Tpreg). Preputial samples from the three males collected pre and post-mating were also analyzed. Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria were the most abundant phyla in vaginal samples. The most abundant genera were Porphyromonas, Anaerococcus, and Peptinophilius. Vaginal microbiota biodiversity decreased during pregnancy. Tenericutes (Ureaplasma spp.) increased significantly at Tpreg in both pregnant and non-pregnant ewes. Differences were observed between pregnant and non-pregnant ewes at Tpreg where pregnant ewes had a significantly higher abundance of Actinobacillus spp. and Ureaplasma spp. Ewes that were diagnosed with pregnancy at Tpreg showed a decreased abundance of gram-negative bacteria such as Bacteroidales, Campylobacterales, and Enterobacteriales. In addition, a significant decrease in the relative abundances of genera within Firmicutes, such as Alloicoccus (Lactobacillales), Atopostipes (Lactobacillales), and an uncultured bacteria W5053 from Family XI (Firmicutes, Clostridiales) was observed in non-pregnant ewes at Tpreg. The four most abundant phyla in the rams' prepuce were the same as in the ewes' vagina. The most abundant genus was Corynebacterium. No major differences were observed in the ram's preputial microbiota between pre and post-mating samples. Nevertheless, the differences in the taxonomic composition of ewes' vaginal microbiota between Testrus and Tpreg could be explained by the exposure to the preputial microbiota. This study offers new insights into the effects of several key steps of the ewe's reproductive cycle such as estrus-synchronization protocol, mating, and pregnancy on ovine vaginal microbiota. The knowledge of the microbiota dynamics during the reproductive cycle can help improve the reproductive outcomes of dams by identifying biomarkers and putative probiotics.Este trabajo fue financiado y aprobado por la subvención para la realización de proyectos de investigación, desarrollo e innovación de grupos de investigación emergentes 2020 (GVA/2020/026), Generalitat Valenciana (España). Además, por el proyecto del Ministerio de Ciencia e Innovación de España (Referencia del proyecto PID2020-119462RA-I00/AEI/10.13039/501100011033).Microbiota reproductivareproductive microbiotaovinesheepmicrobiomepregnantintravaginal spongePublishe

Critically short telomeres and toxicity of chemotherapy in early breast cancer

Cumulative toxicity from weekly paclitaxel (myalgia, peripheral neuropathy, fatigue) compromises long-term administration. Preclinical data suggest that the burden of critically short telomeres ( 21.9% CSTs) had 2-fold higher number of neuropathy (P = 0.04) or fatigue (P = 0.019) episodes and >3-fold higher number of myalgia episodes (P = 0.005). The average telomere length was unrelated to the incidence of side effects.The percentage of CSTs, but not the average telomere size, is associated with weekly paclitaxel-derived toxicity.This work was supported by the Fondo de Investigación Sanitaria [FIS PI10/00288 and FIS PI13/00430]; AECC Scientific Foundation [Beca de Retorno-2010, to MQF]; Spanish Ministry of Economy and Competitiveness Projects [SAF2013-45111-R]; Madrid Regional Government Projects [S2010/BMD- 2303]; AXA Research Found; Fundación Botin; AVON Spain; and Boehringer-Ingelheim Spain.S