Dynamics and pattern formation in invasive tumor growth

In this work, we study the in-vitro dynamics of the most malignant form of the primary brain tumor: Glioblastoma Multiforme. Typically, the growing tumor consists of the inner dense proliferating zone and the outer less dense invasive region. Experiments with different types of cells show qualitatively different behavior. Wild-type cells invade a spherically symmetric manner, but mutant cells are organized in tenuous branches. We formulate a model for this sort of growth using two coupled reaction-diffusion equations for the cell and nutrient concentrations. When the ratio of the nutrient and cell diffusion coefficients exceeds some critical value, the plane propagating front becomes unstable with respect to transversal perturbations. The instability threshold and the full phase-plane diagram in the parameter space are determined. The results are in a good agreement with experimental findings for the two types of cells.Comment: 4 pages, 4 figure

Excellent diagnostic characteristics for ultrafast gene profiling of DEFA1-IL1B-LTF in detection of prosthetic joint infections

The timely and exact diagnosis of prosthetic joint infection (PJI) is crucial for surgical decision-making. Intraoperatively, delivery of the result within an hour is required. Alpha-defensin lateral immunoassay of joint fluid (JF) is precise for the intraoperative exclusion of PJI; however, for patients with a limited amount of JF and/or in cases where the JF is bloody, this test is unhelpful. Important information is hidden in periprosthetic tissues that may much better reflect the current status of implant pathology. We therefore investigated the utility of the gene expression patterns of 12 candidate genes (TLR1, -2, -4, -6, and 10, DEFA1, LTF, IL1B, BPI, CRP, IFNG, and DEFB4A) previously associated with infection for detection of PJI in periprosthetic tissues of patients with total joint arthroplasty (TJA) (n = 76) reoperated for PJI (n = 38) or aseptic failure (n = 38), using the ultrafast quantitative reverse transcription-PCR (RT-PCR) Xxpress system (BJS Biotechnologies Ltd.). Advanced data-mining algorithms were applied for data analysis. For PJI, we detected elevated mRNA expression levels of DEFA1 (P < 0.0001), IL1B (P < 0.0001), LTF (P < 0.0001), TLR1 (P = 0.02), and BPI (P = 0.01) in comparison to those in tissues from aseptic cases. A feature selection algorithm revealed that the DEFA1-IL1B-LTF pattern was the most appropriate for detection/exclusion of PJI, achieving 94.5% sensitivity and 95.7% specificity, with likelihood ratios (LRs) for positive and negative results of 16.3 and 0.06, respectively. Taken together, the results show that DEFA1-IL1B-LTF gene expression detection by use of ultrafast qRT-PCR linked to an electronic calculator allows detection of patients with a high probability of PJI within 45 min after sampling. Further testing on a larger cohort of patients is needed.Web of Science5592697268

Coverage-dependent adsorption sites in the K/Ru(0001) system: a low-energy electron-diffraction analysis

The two ordered phases p(2 × 2) at a coverage θ = 0.25 and (√3 × √3)R30° at θ = 0.33 of potassium adsorbed on Ru(0001) were analyzed by use of low-energy electron-diffraction (LEED). In the (√3 × √3)R30° phase, the K atoms occupy threefold hcp sites, while in the p(2 × 2) phase the fcc site is favoured. In both phases, the K hard-sphere radii are nearly the same and close to the covalent Pauling radius

Composite Dissolving Microneedles for Coordinated Control of Antigen and Adjuvant Delivery Kinetics in Transcutaneous Vaccination

Transcutaneous administration has the potential to improve therapeutics delivery, providing an approach that is safer and more convenient than traditional alternatives, while offering the opportunity for improved therapeutic efficacy through sustained/controlled drug release. To this end, a microneedle materials platform is demonstrated for rapid implantation of controlled-release polymer depots into the cutaneous tissue. Arrays of microneedles composed of drug-loaded poly(lactide-co-glycolide) (PLGA) microparticles or solid PLGA tips are prepared with a supporting and rapidly water-soluble poly(acrylic acid) (PAA) matrix. Upon application of microneedle patches to the skin of mice, the microneedles perforate the stratum corneum and epidermis. Penetration of the outer skin layers is followed by rapid dissolution of the PAA binder on contact with the interstitial fluid of the epidermis, implanting the microparticles or solid polymer microneedles in the tissue, which are retained following patch removal. These polymer depots remain in the skin for weeks following application and sustain the release of encapsulated cargos for systemic delivery. To show the utility of this approach the ability of these composite microneedle arrays to deliver a subunit vaccine formulation is demonstrated. In comparison to traditional needle-based vaccination, microneedle delivery gives improved cellular immunity and equivalent generation of serum antibodies, suggesting the potential of this approach for vaccine delivery. However, the flexibility of this system should allow for improved therapeutic delivery in a variety of diverse contexts.Massachusetts Institute of Technology. Ragon Institute of MGH, MIT and HarvardNational Institutes of Health (U.S.) (Award AI095109)United States. Army Research Office (Contract W911NF-07-D-0004

Simplicity of extremal eigenvalues of the Klein-Gordon equation

We consider the spectral problem associated with the Klein-Gordon equation for unbounded electric potentials. If the spectrum of this problem is contained in two disjoint real intervals and the two inner boundary points are eigenvalues, we show that these extremal eigenvalues are simple and possess strictly positive eigenfunctions. Examples of electric potentials satisfying these assumptions are given

Multilingual assessment of early child development: Analyses from repeated observations of children in Kenya.

In many low- and middle-income countries, young children learn a mother tongue or indigenous language at home before entering the formal education system where they will need to understand and speak a countrys official language(s). Thus, assessments of children before school age, conducted in a nations official language, may not fully reflect a childs development, underscoring the importance of test translation and adaptation. To examine differences in vocabulary development by language of assessment, we adapted and validated instruments to measure developmental outcomes, including expressive and receptive vocabulary. We assessed 505 2-to-6-year-old children in rural communities in Western Kenya with comparable vocabulary tests in three languages: Luo (the local language or mother tongue), Swahili, and English (official languages) at two time points, 5-6&nbsp;weeks apart, between September 2015 and October 2016. Younger children responded to the expressive vocabulary measure exclusively in Luo (44%-59% of 2-to-4-year-olds) much more frequently than did older children (20%-21% of 5-to-6-year-olds). Baseline receptive vocabulary scores in Luo (β&nbsp;=&nbsp;0.26, SE&nbsp;=&nbsp;0.05, p&nbsp;&lt;&nbsp;0.001) and Swahili (β&nbsp;=&nbsp;0.10, SE&nbsp;=&nbsp;0.05, p&nbsp;=&nbsp;0.032) were strongly associated with receptive vocabulary in English at follow-up, even after controlling for English vocabulary at baseline. Parental Luo literacy at baseline (β&nbsp;=&nbsp;0.11, SE&nbsp;=&nbsp;0.05, p&nbsp;=&nbsp;0.045) was associated with child English vocabulary at follow-up, while parental English literacy at baseline was not. Our findings suggest that multilingual testing is essential to understanding the developmental environment and cognitive growth of multilingual children

Polymer multilayer tattooing for enhanced DNA vaccination

DNA vaccines have many potential benefits but have failed to generate robust immune responses in humans. Recently, methods such as in vivo electroporation have demonstrated improved performance, but an optimal strategy for safe, reproducible, and pain-free DNA vaccination remains elusive. Here we report an approach for rapid implantation of vaccine-loaded polymer films carrying DNA, immune-stimulatory RNA, and biodegradable polycations into the immune-cell-rich epidermis, using microneedles coated with releasable polyelectrolyte multilayers. Films transferred into the skin following brief microneedle application promoted local transfection and controlled the persistence of DNA and adjuvants in the skin from days to weeks, with kinetics determined by the film composition. These ‘multilayer tattoo’ DNA vaccines induced immune responses against a model HIV antigen comparable to electroporation in mice, enhanced memory T-cell generation, and elicited 140-fold higher gene expression in non-human primate skin than intradermal DNA injection, indicating the potential of this strategy for enhancing DNA vaccination.Howard Hughes Medical Institute (Investigator)Ragon Institute of MGH, MIT, and HarvardNational Institutes of Health (U.S.) (NIH AI095109)United States. Dept. of Defense. Institute for Soldier Nanotechnologies (contract W911NF-07-D-0004)United States. Dept. of Defense. Institute for Soldier Nanotechnologies (contract W911NF-07-0004

La didáctica de la simulación Clínica: innovar en el sistema de evaluación de competencias. Estudio de caso en la Universidad Nacional del Nordeste

 La investigación detalla el estudio sobre las Prácticas Pedagógicas Innovadoras, acotado al ámbito universitario. Estas prácticas poseen características específicas: actitud investigativa, de revisión y transformación de las propias prácticas.El problema de investigación gira en torno a las concepciones docentes, características y valores de utilidad de las prácticas pedagógicas innovadoras de profesores universitarios de la Universidad Nacional del Nordeste.Esta presentación tiene como objetivo, exponer las prácticas pedagógicas innovadoras vinculadas a prácticas de simulación en la enseñanza clínica que llevaron adelante docentes de la Facultad de Medicina de la Universidad Nacional del Nordeste, buscando identificar la influencia de las mismas en el aprendizaje de los estudiantes. Metodológicamente nos encuadramos el paradigma cualitativo, en el tipo descriptivo- explicativo desde un estudio de casos.En este espacio comunicaremos resultados de los análisis que hemos realizado dentro de la “Práctica Final Obligatoria” de la carrera de Medicina, y específicamente en el “Gabinete de Simulación”. Entre los resultados sobresalientes mencionamos que el espacio se ubicaría dentro de un Enfoque Didáctico Problematizador, identificando que los docentes se presentan como mediadores entre los estudiantes y la práctica clínica, proporcionando ayudas necesarias para que el sujeto avance progresivamente en la apropiación de los saberes y el ejercicio de las prácticas profesionales. A modo de conclusión, consideramos que estos docentes, promovieron a la innovación educativa como un “cambio justificado”

Walking—and Running and Jumping—with Dinosaurs and their Cousins, Viewed Through the Lens of Evolutionary Biomechanics

Archosauria diversified throughout the Triassic Period before experiencing two mass extinctions near its end∼201 Mya, leaving only the crocodile-lineage (Crocodylomorpha) and bird-lineage (Dinosauria) as survivors; along with thepterosaurian flying reptiles. About 50 years ago, the “locomotor superiority hypothesis” (LSH) proposed that dinosaurs ultimatelydominated by the Early Jurassic Period because their locomotion was superior to other archosaurs’. This idea has beendebated continuously since, with taxonomic andmorphological analyses suggesting dinosaurs were “lucky” rather than survivingdue to being biologically superior. However, the LSH has never been tested biomechanically. Here we present integrationof experimental data from locomotion in extant archosaurs with inverse and predictive simulations of the same behavioursusing musculoskeletal models, showing that we can reliably predict how extant archosaurs walk, run and jump. These simulationshave been guiding predictive simulations of extinct archosaurs to estimate how they moved, and we show our progressin that endeavour. The musculoskeletal models used in these simulations can also be used for simpler analyses of form andfunction such as muscle moment arms, which inform us about more basic biomechanical similarities and differences betweenarchosaurs. Placing all these data into an evolutionary and biomechanical context, we take a fresh look at the LSH as part of acritical review of competing hypotheses for why dinosaurs (and a few other archosaur clades) survived the Late Triassic extinctions.Early dinosaurs had some quantifiable differences in locomotor function and performance vs. some other archosaurs, butother derived dinosaurian features (e.g., metabolic or growth rates, ventilatory abilities) are not necessarily mutually exclusivefrom the LSH; or maybe even an opportunistic replacement hypothesis; in explaining dinosaurs’ success.Fil: Cuff, A. R.. The Royal Veterinary College; Reino UnidoFil: Demuth, O. E.. The Royal Veterinary College; Reino UnidoFil: Michel, K.. The Royal Veterinary College; Reino UnidoFil: Otero, Alejandro. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Pintore, R.. The Royal Veterinary College; Reino UnidoFil: Polet, D. T.. The Royal Veterinary College; Reino UnidoFil: Wiseman, A. L .A.. The Royal Veterinary College; Reino UnidoFil: Hutchinson, J. R.. The Royal Veterinary College; Reino Unid