Opportunities and challenges of unplanned follow-up interviews: Experiences with Polish migrants in London

Although there is growing interest in qualitative longitudinal research as a way of taking time seriously (ADAM, 2000), this approach still holds many challenges for the social researcher. In this article we use a reflexive approach, drawing on a Goffmanian analysis of self-presentation, to consider our separate but related experience of re-interviewing Polish migrants over intervals of several years. In each case, the repeat interviews were not part of the original research design and were undertaken years later for a range of different reasons. After briefly presenting case studies from our individual interviews, we critically reflect upon some opportunities and challenges of researching change through time. We first consider the ways in which repeat interviews may challenge earlier analyses and findings. We then explore some of the ethical considerations involved in unplanned repeat interviews. Next, we reflect upon dilemmas about self-revelation, particularly in contexts of social media and on-line technologies. Finally, we discuss what we have learned from our different experiences and what implications there are for this kind of ad hoc longitudinal research in migration studies

Characterization of hair-follicle side population cells in mouse epidermis and skin tumors.

A subset of cells, termed side-population (SP), which have the ability to efflux Hoeschst 33342, have previously been demonstrated to act as a potential method to isolate stem cells. Numerous stem/progenitor cells have been localized in different regions of the mouse hair follicle (HF). The present study identified a SP in the mouse HF expressing the ABCG2 transporter and MTS24 surface marker. These cells are restricted to the upper isthmus of the HF and have previously been described as progenitor cells. Consistent with their SP characteristic, they demonstrated elevated expression of ABCG2 transporter, which participates in the dye efflux. Analysis of tumor epidermal cell lines revealed a correlation between the number of SP keratinocytes and the grade of malignancy, suggesting that the SP may play a role in malignant progression. Consistent with this idea, the present study observed an increased number of cells expressing ABCG2 and MTS24 in chemically induced skin tumors and skin tumor cell lines. This SP does not express the CD34 surface marker detected in the multipotent stem cells of the bulge region of the HF, which have been defined as tumor initiation cells. The present study concluded that a SP with properties of progenitor cells is localized in the upper isthmus of the HF and is important in mouse skin tumor progression

Cyclin D3 deficiency inhibits skin tumor development, but does not affect normal keratinocyte proliferation.

Rearrangement and amplification of the D-type cyclin genes have been reported in human cancer. Previous studies have demonstrated that Ras-mediated skin tumorigenesis depends on pathways that act through cyclin D1 and D2; however, the role of cyclin D3 remains unknown. The present study demonstrates that cyclin D3 ablation does not affect keratinocyte proliferation, but instead increases apoptosis levels in the bulge region of the hair follicle. Consequently, cyclin D3 ablation reduces skin papilloma development in a Ras-dependent carcinogenesis model. Previous results revealed that cyclin D3 preferentially binds to cyclin-dependent kinase 6 (CDK6) in mouse keratinocytes and transgenic expression of CDK6 (K5CDK6 mice) inhibits skin tumor development. Thus, we hypothesized that the inhibitory effect of CDK6 is dependent on cyclin D3 expression. To test this hypothesis, a mouse model that overexpresses CDK6 and does not express cyclin D3 (K5CDK6/cyclin D3-/- compound mouse) was developed. Biochemical analysis of the epidermis of K5CDK6/cyclin D3-/- mice revealed that cyclin D3 ablation resulted in increased expression of cyclin D1 protein, with a consequent elevation in the level of CDK6/cyclin D1 and CDK4/cyclin D1 complexes. These findings were concurrent with the increase skin papilloma malignant progression observed in K5CDK6/cyclin D3-/- mice. In summary the absence of cyclin D3 led to fewer number of papillomas in cyclin D3-ablated mice than in the wild-type owing to increased apoptosis, suggesting that alterations in cell survival are a crucial mechanism for crippling cellular defense against neoplasia. The results of the current study also suggest that although cyclin D3 expression does not alter the tumor suppressive role of CDK6 in skin carcinogenesis, the compensatory increase in cyclin D1 can shift the balance towards malignant progression

Politicas agrarias y estrategias campesinas en la Cuenca del Canete : anexos 8 a 13

Ce document réunit plusieurs diagnostics établis à partir d'observations de terrain sur la géographie physique, l'organisation sociale, les pratiques paysannes dans la vallée de Canete et la vallée Pampas afin de déterminer les facteurs limitants de la production et des pratiques culturales , notamment en matière d'irrigation

Analysis of milk using a portable potentiometric electronic tongue based on five polymeric membrane sensors

A portable potentiometric electronic tongue (PE-tongue) was developed and applied to evaluate the quality of milk with different fat content (skimmed, semi-skimmed, and whole) and with different nutritional content (classic, calcium-enriched, lactose-free, folic acid-enriched, and enriched in sterols of vegetal origin). The system consisted of a simplified array of five sensors based on PVC membranes, coupled to a data logger. The five sensors were selected from a larger set of 20 sensors by applying the genetic algorithm (GA) to the responses to compounds usually found in milk including salts (KCl, CaCl2, and NaCl), sugars (lactose, glucose, and galactose), and organic acids (citric acid and lactic acid). Principal component analysis (PCA) and support vector machine (SVM) results indicated that the PE-tongue consisting of a five-electrode array could successfully discriminate and classify milk samples according to their nutritional content. The PE-tongue provided similar discrimination capability to that of a more complex system formed by a 20-sensor array. SVM regression models were used to predict the physicochemical parameters classically used in milk quality control (acidity, density, %proteins, %lactose, and %fat). The prediction results were excellent and similar to those obtained with a much more complex array consisting of 20 sensors. Moreover, the SVM method confirmed that spoilage of unsealed milk could be correctly identified with the simplified system and the increase in acidity could be accurately predicted. The results obtained demonstrate the possibility of using the simplified PE-tongue to predict milk quality and provide information on the chemical composition of milk using a simple and portable system.We appreciate the financial support of MINECO-FEDER Plan Nacional (RTI 2018-097990-B-100) and Junta de Castilla y Leon - FEDER (VA275P18) and “Infraestructuras Red de Castilla y León (INFRARED)” UVA01info:eu-repo/semantics/publishedVersio

Aprovechamiento de residuos de la industria textil para la preparación de telas de carbón activo.

Los residuos generados por la industria textil en España se han cuantificado sobre unas 30.000 Toneladas durante los últimos años. Debido al gran volumen de almacenamiento que necesitan estos residuos, así como la problemática generada por la disponibilidad geográfica, hacen que sea de gran interés el estudio del aprovechamiento de estos materiales, siendo de gran importancia la obtención de materiales carbonosos que poseen originariamente una estructura fibrilar en forma continua, cuya forma presenta características muy interesantes para distintas aplicaciones. En el presente trabajo se muestran los resultados de preparación y caracterización de materiales carbonosos a partir de residuos de la industria textil, usando como materia prima tejidos de algodón, los cuales se activarán químicamente con H3PO4. Las telas de carbón activo obtenidas serán usadas para testar su aplicación como adsorbentes y como materiales para almacenamiento de energía.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Mechanical and fracture characterization of 50:50 HDPE/PET blends presenting different phase morphologies

Uncompatibilized and compatibilized blends of poly(ethytene terephthalate) (PET) and high-density polyethylene (HDPE) (50:50 PET/HDPE) have been prepared and characterized. A commercial grade of ethylene/methacrylic acid copolymer was used as compatibilizing agent and added to the blends in two different proportions, 1 % and 7%. Compounded blends were processed following three different procedures: compression molding, extrusion, and extrusion followed by annealing. In every case, there is evidence that suggests that HDPE constitutes the matrix and PET is the dispersed phase. The PET phase shape was related to the processing procedure of the blends. PET adopted a globular morphology in the compression molded samples but it took the form of microfibers (microfibrillar-like reinforced composites) in extruded samples, which were flattened during the postextrusion annealing process. According to the results obtained in tensile and fracture tests, extruded blends having 7% of ethylene/methacrylic acid copolymer appeared as the optimum combination of processing method and compatibilizer content.Fil: Fasce, Laura Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Seltzer, Rocío. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Frontini, Patricia Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Pita, V.J. Rodriguez. Universidade Federal do Rio de Janeiro; BrasilFil: Pacheco, E.B.A.V.. Universidade Federal do Rio de Janeiro; BrasilFil: Dias, M.L.. Universidade Federal do Rio de Janeiro; Brasi