A diphtheria toxin resistance marker for in vitro and in vivo selection of stably transduced human cells

We developed a selectable marker rendering human cells resistant to Diphtheria Toxin (DT). The marker (DT(R)) consists of a primary microRNA sequence engineered to downregulate the ubiquitous DPH2 gene, a key enzyme for the biosynthesis of the DT target diphthamide. DT(R) expression in human cells invariably rendered them resistant to DT in vitro, without altering basal cell growth. DT(R)-based selection efficiency and stability were comparable to those of established drug-resistance markers. As mice are insensitive to DT, DT(R)-based selection can be also applied in vivo. Direct injection of a GFP-DT(R) lentiviral vector into human cancer cell-line xenografts and patient-derived tumorgrafts implanted in mice, followed by systemic DT administration, yielded tumors entirely composed of permanently transduced cells and detectable by imaging systems. This approach enabled high-efficiency in vivo selection of xenografted human tumor tissues expressing ectopic transgenes, a hitherto unmet need for functional and morphological studies in laboratory animals

Visualizing the functional architecture of the endocytic machinery.

Clathrin-mediated endocytosis is an essential process that forms vesicles from the plasma membrane. Although most of the protein components of the endocytic protein machinery have been thoroughly characterized, their organization at the endocytic site is poorly understood. We developed a fluorescence microscopy method to track the average positions of yeast endocytic proteins in relation to each other with a time precision below 1 s and with a spatial precision of ~10 nm. With these data, integrated with shapes of endocytic membrane intermediates and with superresolution imaging, we could visualize the dynamic architecture of the endocytic machinery. We showed how different coat proteins are distributed within the coat structure and how the assembly dynamics of N-BAR proteins relate to membrane shape changes. Moreover, we found that the region of actin polymerization is located at the base of the endocytic invagination, with the growing ends of filaments pointing toward the plasma membrane

La programación de la enseñanza como contenido de la formación de los profesores

En esta comunicación nos proponemos reflexionar en torno a las prácticas de enseñanza que llevamos a cabo en la asignatura "Didáctica y curriculum" destinada a la formación pedagógica de los estudiantes que cursan distintos profesorados en el área de ciencias sociales y humanidades en la Universidad Nacional de La Plata. Específicamente nuestra intención apunta a narrar y sistematizar la experiencia en torno a la enseñanza de "la programación de la enseñanza" como contenido fundamental en la formación pedagógica de los futuros profesores así como también en el ejercicio profesional de la docencia. Pretendemos además recuperar categorías teóricas aportadas por la didáctica y el curriculum para la reflexión en torno a la "programación de la enseñanza", entendida como posible contenido y práctica de articulación de estas dos disciplinas. Sostenemos que la programación de la enseñanza es un proceso complejo de concreción progresiva de las intenciones formativas que coloca al docente en un lugar de toma de decisiones permanentes y fundamentadas para llevar a cabo la enseñanza de una manera responsable. Brindar a los estudiantes elementos conceptuales e instrumentales para esta práctica, forma parte de los propósitos de nuestra asignatura.Facultad de Humanidades y Ciencias de la Educació

Reflexiones en torno a los aportes conceptuales e instrumentales de la didáctica general a la formación de profesores universitarios

En este trabajo nos proponemos reflexionar sobre los aportes conceptuales e instrumentales que puede realizar la Didáctica general a la formación de profesores universitarios a partir de la experiencia realizada en la cátedra "Diseño y planeamiento del curriculum" perteneciente a la Facultad de Humanidades y Ciencias de la Educación (FaHCE), Universidad Nacional de La Plata (UNLP). Se trata de una asignatura perteneciente al Profesorado en Psicología (Facultad de Psicología, UNLP) y a distintos Profesorados que se cursan en la FaHCE (UNLP). La cursada de la materia se propone favorecer que los estudiantes analicen e intervengan en diversos temas y problemas que son constitutivos de la docencia a partir de acercamientos progresivos a la práctica, reservando la inserción institucional para el espacio de las "Prácticas de la enseñanza" específicas de cada profesorado, según lo estipulado en los respectivos planes de estudio. El programa de la asignatura posee cinco unidades organizadas desde aquéllas que poseen contenidos más instrumentales, vinculados a las prácticas de enseñanza y a la intervención presente o futura de los estudiantes, hasta aquéllas otras de corte más teórico, relativas a desarrollos conceptuales que teorizan sobre esas prácticas. En este sentido, iniciamos con el análisis de la enseñanza y el curriculum como objetos de estudio y de intervención y finalizamos el recorrido formativo estudiando teorías didácticas y curriculares. Con el análisis del programa de "Diseño y planeamiento del curriculum", anclado en los planes de estudio correspondientes y en estrecha relación con las vicisitudes que su puesta en marcha genera, pretendemos sistematizar los aportes conceptuales e instrumentales de la Didáctica general a la formación de profesores universitarios, sustentándonos en la concepción de que la Didáctica es una caja de herramientas que ayuda a los docentes a explicar sus prácticas de enseñanza, así como a intervenir y fundamentar sus intervenciones en ellas. La Didáctica es una disciplina que desde sus orígenes se caracteriza por poseer una dimensión normativa, es decir, una preocupación por la elaboración de orientaciones hacia las prácticas de enseñanza. Esta normativa siempre permanece abierta a las interpretaciones y recontextualizaciones que los sujetos docentes puedan realizarle con el propósito de resolver los problemas concretos de la enseñanza.Facultad de Humanidades y Ciencias de la Educació

Magnetic-glassy multicritical behavior of the three-dimensional +- J Ising model

We consider the three-dimensional $\pm J$ model defined on a simple cubic lattice and study its behavior close to the multicritical Nishimori point where the paramagnetic-ferromagnetic, the paramagnetic-glassy, and the ferromagnetic-glassy transition lines meet in the T-p phase diagram (p characterizes the disorder distribution and gives the fraction of ferromagnetic bonds). For this purpose we perform Monte Carlo simulations on cubic lattices of size $L\le 32$ and a finite-size scaling analysis of the numerical results. The magnetic-glassy multicritical point is found at $p^*=0.76820(4)$, along the Nishimori line given by $2p-1={\rm Tanh}(J/T)$. We determine the renormalization-group dimensions of the operators that control the renormalization-group flow close to the multicritical point, $y_1 = 1.02(5)$, $y_2 = 0.61(2)$, and the susceptibility exponent $\eta = -0.114(3)$. The temperature and crossover exponents are $\nu=1/y_2=1.64(5)$ and $\phi=y_1/y_2 = 1.67(10)$, respectively. We also investigate the model-A dynamics, obtaining the dynamic critical exponent $z = 5.0(5)$.Comment: 17 page

Leptospirosis in cats : current literature review to guide diagnosis and management

Leptospirosis is the most widespread zoonosis worldwide. Mammals (eg, rats, horses, cows, pigs, dogs, cats and aquatic species, such as sea lions and northern elephant seals) can all be infected by leptospires. Infection in animals occurs through contact with urine or water contaminated with the bacteria. In people, the disease is acquired mainly from animal sources or through recreational activities in contaminated water

Multicritical Nishimori point in the phase diagram of the +- J Ising model on a square lattice

We investigate the critical behavior of the random-bond +- J Ising model on a square lattice at the multicritical Nishimori point in the T-p phase diagram, where T is the temperature and p is the disorder parameter (p=1 corresponds to the pure Ising model). We perform a finite-size scaling analysis of high-statistics Monte Carlo simulations along the Nishimori line defined by $2p-1={\rm Tanh}(1/T)$, along which the multicritical point lies. The multicritical Nishimori point is located at p^*=0.89081(7), T^*=0.9528(4), and the renormalization-group dimensions of the operators that control the multicritical behavior are y_1=0.655(15) and y_2 = 0.250(2); they correspond to the thermal exponent \nu= 1/y_2=4.00(3) and to the crossover exponent \phi= y_1/y_2=2.62(6).Comment: 23 page

The Relationship between Work, Health and Job Performance for a Sustainable Working Life: A Case Study on Older Manual Employees in an Italian Steel Factory

Background: Supporting and retaining older workers has become a strategic management goal for companies, considering the ageing of the workforce and the prolongation of working lives. The relationship between health and work is especially crucial for older workers with manual tasks, considering the impact of long-standing health impairments in older age. Although different studies investigated the relationship between work ability and job performance, few studies have analysed the impact of workers’ capability to balance between health and work demands, including managerial and organisational support (work-health balance). Considering health as a dynamic balance between work and health demands influenced by both individual and environmental factors, we assess the mediator role of work-health balance in the relation between work ability and job performance, both self-reported and assessed by the supervisor. Methods: The study utilises data from a case study of 156 manual workers, who were 50 years old or older and employed in a steel company in Italy. Data were collected inside the company as an organiational initiative to support age diversity. Results: The findings show that work-health balance partially mediates the relationship between work ability and self-rated job performance, while it does not mediate the relationship with job performance as rated by the supervisor. Supervisor-rated job performance is positively associated with work ability, while it decreases with the increasing perceived incompatibility between work and health. Conclusion: A perceived balance between health and work is a strategic factor in increasing manual older workers’ job performance. For older workers, not only the perceived capability to work is important but also the organisational health climate and supervisor’s support. More studies are needed to verify if managers overlook the importance of health climate and support, as strategic elements that can foster performance for older employees.publishedVersionPeer reviewe

PyF2F: a robust and simplified fluorophore-to-fluorophore distance measurement tool for Protein interactions from Imaging Complexes after Translocation experiments

Structural knowledge of protein assemblies in their physiological environment is paramount to understand cellular functions at the molecular level. Protein interactions from Imaging Complexes after Translocation (PICT) is a live-cell imaging technique for the structural characterization of macromolecular assemblies in living cells. PICT relies on the measurement of the separation between labelled molecules using fluorescence microscopy and cell engineering. Unfortunately, the required computational tools to extract molecular distances involve a variety of sophisticated software programs that challenge reproducibility and limit their implementation to highly specialized researchers. Here we introduce PyF2F, a Python-based software that provides a workflow for measuring molecular distances from PICT data, with minimal user programming expertise. We used a published dataset to validate PyF2F’s performance