Carbon sources and polyethylene glycol on soybean somatic embryo conversion

Somatic embryogenesis is an efficient method for the production of target cells for soybean genetic transformation. However, this method still offers low percentages of plant regeneration, and perhaps is related to the maturation process and high morphological abnormalities of the matured embryos. This study aimed to identify a maturation medium that could contribute to the outcome of more efficient plant regeneration results. Embryogenic clusters, derived from cotyledons of immature seeds of the soybean cultivars Bragg and IAS5, were used as starting material for embryos development. Different maturation media were tested by using 6% maltose, 3% sucrose or 6% sucrose, combined with or without 25 g L-1 of the osmotic regulator polyethylene glycol (PEG-8000). The histodifferentiated embryos were quantified and classified in morphological types. Percentages of converted embryos were analyzed. Cultivar Bragg resulted in higher matured embryo quantities, but lower percentages were obtained for the conversion in comparison to cultivar IAS5. While the addition of PEG did not affect the number of embryos converted into plants, 6% sucrose enhanced the conversion percent significantly.

2009 Cancer in Iowa Report: Data Sources, 2009

Cancer is a reportable disease as stated in the Iowa Administrative Code. Cancer data are collected by the State Health Registry of Iowa, located at The University of Iowa in the College of Public Health’s Department of Epidemiology. The staff includes more than 50 people. Half of them, situated throughout the state, regularly visit hospitals, clinics, and medical laboratories in Iowa and neighboring states to collect cancer data. A follow-up program tracks more than 99 percent of the cancer survivors diagnosed since 1973. This program provides regular updates for follow-up and survival. The Registry maintains the confidentiality of the patients, physicians, and hospitals providing data. In 2009 data will be collected on an estimated 16,000 new cancers among Iowa residents. In situ cases of bladder cancer are included in the estimates for bladder cancer, to be in agreement with the definition of reportable cases of the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute. Since 1973 the Iowa Registry has been funded primarily by the SEER Program of the National Cancer Institute. Iowa represents rural and Midwestern populations and provides data included in many National Cancer Institute publications. Beginning in 1990 between 5 and 10 percent of the Registry’s annual operating budget has been provided by the state of Iowa. Beginning in 2003, the University of Iowa has been providing cost-sharing funds. The Registry also receives funding through grants and contracts with university, state, and national researchers investigating cancer-related topics.

Bone histomorphometry of broilers submitted to different phosphorus sources in growing and finisher rations

The objective of this work was to identify alterations in the histomorphology of the cortical bone tissue of broilers submitted to growing and finisher rations formulated with five different sources of phosphorus: dicalcium phosphate, simple superphosphate, triple superphosphate, monoammonium phosphate and Araxá rock phosphate. Histological images had their components segmented, and were called regions of interest (ROI). Images were analyzed through developed algorithms, using the SCILAB mathematical environment. Eleven features were considered in order to obtain a complete description of the bone images: percentage of bone by area, ROI area, ROI perimeters, ROI elongation, ROI angle and their respective standard deviations, besides entropy of ROI angles and a texture-oriented measure (lacunarity). The substitution of dicalcium phosphate in growing and finisher rations for any other tested source of phosphorus caused significant changes on the hystomorphology of the cortical broilers bones, for example: diminution of bone percentage by area, increase of lacuna area and worse matrix homogeneity. Changes were more pronounced in the Araxá rock phosphate treatments, with the highest fluorine content, than in simple superphosphate, triple superphosphate and monoammonium phosphate treatments, which were similar.

Selective ablation of photovoltaic materials with UV laser sources for monolithic interconnection of devices based on a-Si:H

Lasers are essential tools for cell isolation and monolithic interconnection in thin-film-silicon photovoltaic technologies. Laser ablation of transparent conductive oxides (TCOs), amorphous silicon structures and back contact removal are standard processes in industry for monolithic device interconnection. However, material ablation with minimum debris and small heat affected zone is one of the main difficulty is to achieve, to reduce costs and to improve device efficiency. In this paper we present recent results in laser ablation of photovoltaic materials using excimer and UV wavelengths of diode-pumped solid-state (DPSS) laser sources. We discuss results concerning UV ablation of different TCO and thin-film silicon (a-Si:H and nc-Si:H), focussing our study on ablation threshold measurements and process-quality assessment using advanced optical microscopy techniques. In that way we show the advantages of using UV wavelengths for minimizing the characteristic material thermal affection of laser irradiation in the ns regime at higher wavelengths. Additionally we include preliminary results of selective ablation of film on film structures irradiating from the film side (direct writing configuration) including the problem of selective ablation of ZnO films on a-Si:H layers. In that way we demonstrate the potential use of UV wavelengths of fully commercial laser sources as an alternative to standard backscribing process in device fabrication.

La conception du "dialogue" de Mikhaïl Bakhtine et ses sources sociologiques (l'exemple des "Problèmes de l'oeuvre de Dostoïevski" [1929])

Résumé: L'article porte sur la conception du « dialogue » de Mikhaïl Bakhtine dans laquelle s'articulent deux groupes d'idées : 1) la notion de « dialogue » en tant que forme de l'interaction verbale interindividuelle (l'échange des répliques) et 2) la notion de « dialogisme » comme principe qui prévoit un rapport particulier entre le « Moi » (le « Je ») et l'« Autrui ». Son but consiste à 1) analyser ces notions au sens de Bakhtine, en s'appuyant sur le texte russe des Problèmes de l'oeuvre de Dostoïevski (1929) ; et à 2) montrer leurs sources sociologiques (principalement russes). Il y est également question de la notion de « polyphonie » introduite par Bakhtine pour caractériser la particularité de la construction des romans de Dostoïevski et d'une facette des réflexions bakhtiniennes sur le rôle de la « polyphonie » chez Dostoïevski, contenues dans le texte russe de 1929, abandonnées dans la version de 1963 et, de ce fait, méconnues des chercheurs francophones n'ayant accès qu'à la traduction des Problèmes de la poétique de Dostoïevski (1963). This paper examines the conception of "dialogue" elaborated by Mikhaïl Bakhtin in which are articulated two groups of ideas : 1) the notion of "dialogue" as a form of verbal interindividual interaction (an exchange of speech) and 2) the notion of "dialogism" as a principle which implies a relation between the "Me" (the "I") and the "Other". Its aim is 1) to analyse these notions in the sens of Bakhtin, on the base of russian text of Problems of Dostoyevsky's Art (1929) and 2) to show their sociological (mainly russian) origins. The paper also deals with the notion of "polyphony" introduced by Bakhtin to characterize the particularity of Dostoyevsky's method of constructing novels and with one facet of bakhtinian reflections (expounded in the text of 1929, omitted in the version of 1963, thereby unknown by francophone researchers who have access only to the translation of Problems of Dostoyevsky's Poetics (1963)) on the role of "polyphony" in Dostoyevsky's works.

Sources d'exposition aux phtalates dans une unité de soins néonatals [Phthalate exposure in the neonatal intensive care unit].

There are growing concerns on long-term health consequences, notably on fertility rates, of plasticizers such as phthalates. While di(2-ethylhexyl)phthalate (DEHP) is currently used in several medical devices, newborns in the neonatal intensive care unit are both more exposed and more vulnerable to DEHP. The objectives of this study were to identify, count, and describe possible sources of DEHP in a neonatal care unit. Our method consisted in the listing and the inspection of the information on packaging, complemented by contact with manufacturers when necessary. According to the results, 6% of all products and 10% of plastic products contained some DEHP; 71% of these involved respiratory support devices. A vast majority of the items showed no information on the content of DEHP. Further research is needed, particularly to determine the effects of such an early exposure and to study and develop safer alternatives.

Modeling morphogen gradient formation from arbitrary realistically shaped sources.

Much of the analytical modeling of morphogen profiles is based on simplistic scenarios, where the source is abstracted to be point-like and fixed in time, and where only the steady state solution of the morphogen gradient in one dimension is considered. Here we develop a general formalism allowing to model diffusive gradient formation from an arbitrary source. This mathematical framework, based on the Green's function method, applies to various diffusion problems. In this paper, we illustrate our theory with the explicit example of the Bicoid gradient establishment in Drosophila embryos. The gradient formation arises by protein translation from a mRNA distribution followed by morphogen diffusion with linear degradation. We investigate quantitatively the influence of spatial extension and time evolution of the source on the morphogen profile. For different biologically meaningful cases, we obtain explicit analytical expressions for both the steady state and time-dependent 1D problems. We show that extended sources, whether of finite size or normally distributed, give rise to more realistic gradients compared to a single point-source at the origin. Furthermore, the steady state solutions are fully compatible with a decreasing exponential behavior of the profile. We also consider the case of a dynamic source (e.g. bicoid mRNA diffusion) for which a protein profile similar to the ones obtained from static sources can be achieved.