As relações de equivalência como critério de análise da pertinência científica de categorias analíticas

El objetivo del presente trabajo es proponer las relaciones de equivalencia como criterio estructural o de ordenamiento analítico mediante el cual se puedan delimitar las funciones del conocimiento requeridas en una actividad científica. Se parte de considerar al conocimiento como un fenómeno estudiado por la psicología y cuya explicación requiere de dar cuenta de la manera en que se establecen, organizan y actualizan las funciones conductuales o del conocimiento. De este modo, se considera que las tareas de igualación a la muestra permiten comprender el modo de abstraer las categorías analíticas que estructuran científicamente el conocimiento de la realidad. Cuando se usan estos procedimiento, se derivan nuevas relaciones sin la necesidad de un entrenamiento directo y que no pueden explicarse con base en principios de generalización de estímulos, sino, más bien, como relaciones equivalentes diferenciadas mediante los entrenamientos previos y que adquieren un cierre en una categoría analítica cuando se abstraen los criterios categoriales o, si se quiere, cuando estas relaciones se nominan. Así, al categorizarse o nominarse, estas trascienden la situación -porque nominar se entiende como un ajuste a criterios convencionales- y una vez que las interacciones situacionales se nominan, regulan todas las prácticas sociales, incluidas las prácticas del conocimiento científico.O objetivo deste trabalho é propor as relações de equivalência como critério estrutural ou de ordenamento analítico pelo qual possam ser delimitadas as funções do conhecimento requeridas numa atividade científica. Parte-se de considerar o conhecimento como um fenômeno estudado pela psicologia e cuja explicação requer evidenciar a maneira na qual são estabelecidas, organizadas e atualizadas as funções comportamentais ou do conhecimento. Desse modo, considera-se que as tarefas de igualação à amostra permitem compreender o modo de abstrair as categorias analíticas que estruturam cientificamente o conhecimento da realidade. Quando são usados esses procedimentos, são derivadas novas relações que, sem a necessidade de um treinamento direto, não podem ser explicadas com base em princípios de generalização de estímulos, mas sim como relações equivalentes diferenciadas mediante os treinamentos prévios e que adquirem uma delimitação numa categoria analítica quando são abstraídos os critérios categoriais ou, se se quiser, quando essas relações são nominadas. Assim, ao serem categorizadas ou nominadas, elas transcendem a situação -porque nominar se entende como um ajuste a critérios convencionais- e, uma vez que as interações situacionais são nominadas, regulam todas as práticas sociais, incluídas as práticas do conhecimento científico.The aim of this paper is to propose equivalence relations as a structural criterion or analytical order, through which the functions of knowledge required in a scientific activity are delimited. It begins by considering knowledge as a phenomenon studied by psychology, whose explanation requires giving an account of the way in which such behavioral or knowledge functions are established, organized and updated. It is considered that the procedures of matching-to-sample allow understanding the way of abstracting the analytical categories that scientifically structure the knowledge of reality. When using these procedures, new relationships are derived that without the need for direct training, cannot be explained based on principles of stimulus generalization, but rather as equivalent relations differentiated through previous training. They get a closure in an analytical category, once the categorical criteria are abstracted or if desired, when these relationships are nominated. And when categorized or nominated, they transcend the situation, since nominating is understood as an adjustment to conventional criteria. Once situational interactions are nominated, they regulate all social practices, including practices of scientific knowledge

Expected and unexpected behavior of the orientational order and dynamics induced by azobenzene solutes in a nematic

We have explored the changes in the phase stability, orientational order, and dynamics of the nematic 4-cyano-4¢-n-pentylbiphenyl (5CB) doped with either the trans or the cis form of different p-azobenzene derivatives using the ESR spin-probe technique. In particular, we have studied the effects induced by each of the seven nonmesogenic 4-R-phenylazobenzenes (R = H, F, Br, CH3, CF3, On-Bu, Ot-Bu) at 1% and 7% mole fraction on the order parameter and on the shift of the nematic-isotropic transition temperature (TNI), as reported by a nitroxide spin probe, and we have tried to relate them to the solute shape and charge distribution. In all the cases the presence of the azo-derivative causes a depression of TNI, more pronounced for the cis isomers. The dependence of on the reduced temperature T*=T/TNI remains the same as that of pure 5CB in all trans-doped samples at 1% and 7% and decreases only slightly in the cis at 1%. However, we observe different and in some cases large variations (up to 25%) in for the cis at 7%, showing solute effects that go beyond the shift in TNI. Surprisingly enough, even at the highest concentration, the probe dynamics appears to be essentially independent of the nature, the configuration, and the concentration of the different solutes and very similar to that observed in the pure 5CB

ECOLOGÍA Y SITUACIÓN ACTUAL DE LA FAMILIA COLUMBIDAE EN LA RESERVA DE LA BIOSFERA LOS TUXTLAS, VERACRUZ

RESUMEN Analizamos la presencia y abundancia de palomas tropicales residentes en la Reserva de la Biosfera Los Tuxtlas, Veracruz, México durante las épocas reproductivas de 2010 y 2011. Se emplearon distintos métodos de conteo para maximizar el registro del mayor número de especies y superar las dificultades del terreno y la vegetación. Muestreamos principalmente a través de transectos y puntos de conteo en bosque tropical perennifolio, bosque mesófilo de montaña, bosque de pino‐encino y áreas agropecuarias, y registramos 512 individuos de 12 de las 17 especies reportadas históricamente. Las especies registradas en el presente fueron: Patagioenas cayennensis, P. speciosa, P. flavirostris, P. nigrirostris, Columbina inca, C. talpacoti, Claravis pretiosa, Geotrygon montana, Leptotila verreauxi, L. plumbeiceps, Zentrygon carrikeri (endémica) y Zenaida asiatica. La mayor riqueza se observó en el bosque tropical perennifolio, en donde la especie más abundante fue L. verreauxi. La abundancia varió significativamente entre tipos de vegetación para L. verreauxi, L. plumbeiceps y Z. carrikeri, posiblemente debido a los diferentes niveles de tolerancia a la perturbación. El bosque mesófilo de montaña fue el hábitat utilizado en mayor proporción a lo esperado para la mayoría de las especies examinadas como: P. flavirostris, C. pretiosa, L. verreauxi, L. plumbeiceps y Z. carrikeri. Las preferencias de hábitat más amplias correspondieron a P. flavirostris, C. pretiosa y L. verreauxi. Tres especies fueron exclusivas a un tipo de vegetación (P. cayennensis y P. nigrirostris en bosque tropical perennifolio; P. speciosa en bosque mesófilo de montaña). El volcán San Martín Pajapan, una de las áreas núcleo de la Reserva de la Biósfera fue muestreada por primera vez, y registramos a L. verreauxi, L. plumbeiceps, al igual que a una importante población de Z. carrikeri, especie endémica cuyas poblaciones conocidas están limitadas a otras tres áreas montañosas de la región. Las poblaciones de palomas que habitan en interior de bosque se encuentran ubicadas en fragmentos de bosque primario aislados, por lo que deben establecerse corredores para evitar el aislamiento de las poblaciones remanentes de especies de palomas en riesgo. ABSTRACT ∙ Ecology and status of pigeons and doves (Columbidae) in Los Tuxtlas Biosphere Reserve, Veracruz, MexicoWe analyzed the presence and abundance of tropical resident pigeons and doves (Columbidae) in Los Tuxtlas Biosphere Reserve, Veracruz, Mexico, during the breeding seasons of 2010 and 2011. We used different survey methods to maximize the detection of different species and overcome terrain and vegetation limitations. We surveyed the area mostly through transects and point counts in evergreen tropical forest, cloud forest, pine‐oak forest, and agricultural areas, including the Reserve core areas, recording 512 individuals of 12 out of 17 columbid species reported historically for the area. We were able to confirm Patagioenas cayennensis, P. speciosa, P. flavirostris, P. nigrirostris, Columbina inca, C. talpacoti, Claravis pretiosa, Geotrygon montana, Leptotila verreauxi, L. plumbeiceps, Zentrygon carrikeri (endemic), and Zenaida asiatica. The tropical evergreen forest is the vegetation type with the highest species richness, and the most abundant species was L. verreauxi. Abundance varied significantly among vegetation types for L. verreauxi, L. plumbeiceps, and Zentrygon carrikeri, possibly due to differences in their tolerance to disturbance. Cloud forest stood out as the most important habitat as it was used more than expected by species such as P. flavirostris, C. pretiosa, L. verreauxi, L. plumbeiceps, and Z. carrikeri. The species with the broadest habitat preferences were P. flavirostris, C. pretiosa, and L. verreauxi. Three species were exclusive to a single vegetation type (P. cayennensis and P. nigrirostris to evergreen tropical forest; P. speciosa to cloud forest). The volcán San Martín Pajapan, one of the Bio‐ sphere Reserve core areas was surveyed for the first time, and we recorded L. verreauxi, L. plumbeiceps, as well as an important population of Z. carrikeri, the latter endemic species being previously only known from three other Mexican mountain ranges. The populations of doves and pigeons inhabiting the forest interior are mostly located in isolated primary forest fragments, therefore corridors should be established to avoid the isolation of the remaining endangered dove populations

Prospective randomized comparison of laparoscopic versus open adrenalectomy for sporadic pheochromocytoma.

BACKGROUND: Laparoscopic adrenalectomy for pheochromocytoma remains subject of debate, owing to the systemic consequences of pneumoperitoneum in patients with catecholamine-secreting tumors. METHODS: A prospective randomized study was conducted (2000-2006), evaluating cardiovascular instability during open (n = 9, group A) or laparoscopic (n = 13, group B) adrenalectomy for pheochromocytoma. Haemodynamic parameters were recorded by invasive monitoring. RESULTS: Haemodynamic instability was observed in 3/9 (group A) and 6/13 patients (group B), with a mean of 1.8 and 2.2 hypertensive peaks per patient (p = n.s.). Blood loss (164 +/- 94 cc versus 48 +/- 36 cc, p < 0.05) and operative time (180 +/- 40 versus 158 +/- 45 min, p = n.s.) favored laparoscopic procedures. Postoperative morbidity and mortality were nil. Hospital stay was shorter in group B (p < 0.05). Long-term follow-up was always normal. CONCLUSIONS: Laparoscopic approach for pheochromocytoma can be as safe as open surgery; intraoperative haemodynamic instability, although usually controlled with success, remains a source of concern

Lynch Syndrome from a surgeon perspective: retrospective study of clinical impact of mismatch repair protein expression analysis in colorectal cancer patients less than 50 years old.

BACKGROUND: In clinical practice, unexpected diagnosis of colorectal cancer in young patients requires prompt surgery, thus genetic testing for Lynch Syndrome is frequently missed, and clinical management may result incorrect. METHODS: Patients younger than 50 years old undergoing colorectal resection for cancer in the period 1994-2007 were identified (Group A, 49 cases), and compared to a group of randomly selected patients more than 50 (Group B, 85 cases). In 31 group A patients, immunohistochemical expression analysis of MLH1, MSH2 and MSH6 was performed; personal and familial history of patients with defective MMR proteins expression was further investigated, searching for synchronous and metachronous tumors in probands and their families. RESULTS: Fifty-one percent of patients did not express one or more MMR proteins (MMR-) and should be considered Lynch Syndrome carriers (16 patients, group A1); while only 31.2% of them were positive for Amsterdam criteria, 50% had almost another tumor, 37.5% had another colorectal tumor and 68% had relatives with colorectal tumor. This group of patients, compared with A2 group (< 50 years old, MMR+) and B group, showed typical characteristics of HNPCC, such as proximal location, mucinous histotype, poor differentiation, high stage and shorter survival. CONCLUSIONS: The present study confirms that preoperative knowledge of MMR proteins expression in colorectal cancer patients would allow correct staging, more extended colonic resection, specific follow-up and familial screening

Eosinophilic inflammation in allergic asthma

Eosinophils are circulating granulocytes involved in pathogenesis of asthma. A cascade of processes directed by Th2 cytokine producing T-cells influence the recruitment of eosinophils into the lungs. Furthermore, multiple elements including interleukin (IL)-5, IL-13, chemoattractants such as eotaxin, Clara cells, and CC chemokine receptor (CCR)3 are already directly involved in recruiting eosinophils to the lung during allergic inflammation. Once recruited, eosinophils participate in the modulation of immune response, induction of airway hyperresponsiveness and remodeling, characteristic features of asthma. Various types of promising treatments for reducing asthmatic response are related to reduction in eosinophil counts both in human and experimental models of pulmonary allergic inflammation, showing that the recruitment of these cells really plays an important role in the pathophysiology of allergic diseases such asthma.Univ São Paulo, Sch Med, Dept Med, BR-01246 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biol Sci, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biol Sci, São Paulo, BrazilWeb of Scienc

p75 neurotrophin receptor mediates apoptosis in transit-amplifying cells and its overexpression restores cell death in psoriatic keratinocytes.

p75 neurotrophin receptor (p75NTR) belongs to the TNF-receptor superfamily and signals apoptosis in many cell settings. In human epidermis, p75NTR is mostly confined to the transit-amplifying (TA) sub-population of basal keratinocytes. Brain-derived neurotrophic factor (BDNF) or neurotrophin-4 (NT-4), which signals through p75NTR, induces keratinocyte apoptosis, whereas β-amyloid, a ligand for p75NTR, triggers caspase-3 activation to a greater extent in p75NTR transfected cells. Moreover, p75NTR co-immunoprecipitates with NRAGE, induces the phosphorylation of c-Jun N-terminal kinase (JNK) and reduces nuclear factor kappa B (NF-κB) DNA-binding activity. p75NTR also mediates pro-NGF-induced keratinocyte apoptosis through its co-receptor sortilin. Furthermore, BDNF or β-amyloid cause cell death in TA, but not in keratinocyte stem cells (KSCs) or in p75NTR silenced TA cells. p75NTR is absent in lesional psoriatic skin and p75NTR levels are significantly lower in psoriatic than in normal TA keratinocytes. The rate of apoptosis in psoriatic TA cells is significantly lower than in normal TA cells. BDNF or β-amyloid fail to induce apoptosis in psoriatic TA cells, and p75NTR retroviral infection restores BDNF- or β-amyloid-induced apoptosis in psoriatic keratinocytes. These results demonstrate that p75NTR has a pro-apoptotic role in keratinocytes and is involved in the maintenance of epidermal homeostasis

Quantitative Nanomechanical Properties of Multilayer Films Made of Polysaccharides through Spray Assisted Layer-by-Layer Assembly.

Nanomechanical properties of alginate/chitosan (Alg/Chi) multilayer films, obtained through spray assisted layer-by-layer assembly, were studied by means of PeakForce quantitative nanomechanical mapping atomic force microscopy (PF-QNM AFM). Prepared at two different alginate concentrations (1.0 and 2.5 mg/mL) and a fixed chitosan concentration (1.0 mg/mL), Alg/Chi films have an exponential growth in thickness with a transition to a linear growth toward a plateau by increasing the number of deposited bilayers. Height, elastic modulus, deformation, and adhesion maps were simultaneously recorded depending on the number of deposited bilayers. The elastic modulus of Alg/Chi films was found to be related to the mechanism of growth in contrast to the adhesion and deformation. A comparison of the nanomechanical properties obtained for non-cross-linked and thermally cross-linked Alg/Chi films revealed an increase of the elastic modulus after cross-linking regardless alginate concentration. The incorporation of iron oxide nanoparticles (NPs), during the spray preparation of the films, gave rise to nanocomposite Alg/Chi films with increased elastic moduli with the number of incorporated NPs layers. Deformation maps of the films strongly suggested the presence of empty spaces associated with the method of preparation. Finally, adhesion measurements point out to a significant role of NPs on the increase of the adhesion values found for nanocomposite films.journal article2017 01 092016 12 15importe

Keratinocytes enriched for stem cells are protected from anoikis via an integrin signaling pathway in a Bcl-2 dependent manner

AbstractBecause inhibition of integrin signaling induces apoptosis, we investigated whether keratinocytes expressing β1 and α6β4 integrins (enriched for stem cells) are protected from cell death. Keratinocytes rapidly adhering to type IV collagen expressed highest levels of β1 and α6β4 and of the anti-apoptotic stem cell marker p63. Apoptotic cells were significantly higher in slowly adhering than in rapidly adhering keratinocytes. Anti-β1 integrin caused a significant increase in apoptotic cells, while it decreased Bcl-2 levels in stem keratinocytes. Bax and Bad proteins were higher in slowly adhering than in rapidly adhering cells. By contrast, Bcl-2, Bcl-x and Mcl-1 proteins were highest in rapidly adhering keratinocytes and nearly absent in slowly adhering cells. After addition of anti-β1 integrin, the apoptotic rate was significantly higher in HaCaT cells not expressing Bcl-2 than in controls. These results indicate that keratinocytes enriched for stem cells are protected from apoptosis via β1 integrin, in a Bcl-2 dependent manner