Variabilidad en el tamaño de ovocitos y fecundidad parcial de anchoveta (Engraulis ringens, Jenyns 1842) en dos áreas de desove de la costa de Chile

Utilising histological preparations of ovaries from Engraulis ringens females collected in two contrasting spawning habitats along the Chilean coast, we assess the variability in oocyte size and batch fecundity during the peak spawning seasons in three years. The effects of female size (length and weight), batch fecundity and mean sea surface temperature on oocyte size were also examined. Results showed larger oocytes and lower batch fecundity in females from the southern area. Oocyte volume differences persisted inter-annually and were not explained by differences in female sizes. Since ovary weight was similar between areas, the cost of producing larger oocytes in the south population seems to be a fecundity reduction. The latitudinal variations in oocyte number and size seem to be determined by the predominant environmental conditions in each habitat. Hence, female E. ringens seem to adapt their reproductive tactics by producing eggs sizes and quantities that favour survival of their offspring under the environmental conditions in which they are to develop.Utilizando preparaciones histológicas de ovarios de anchovetas (Engraulis ringens) colectadas en dos hábitats contrastantes a lo largo de la costa de Chile, se estudia la variabilidad en tamaño de ovocitos y fecundidad parcial en la estación de máximo desove durante tres años. Los efectos de tamaño de hembra (longitud total y peso total), fecundidad parcial y temperatura superficial del mar sobre el tamaño de los ovocitos, también fueron investigados. Los resultados mostraron ovocitos más grandes y menor fecundidad en hembras de la zona sur. Las diferencias en volumen de ovocitos persistieron inter-anualmente y no fueron explicadas por diferencias en el tamaño de las hembras. Dado que los pesos de los ovarios fueron similares entre zonas, el coste de producir ovocitos más grandes en la población del sur sería la reducción en la fecundidad. Las variaciones latitudinales en número y tamaño de ovocitos parecen ser determinadas por las condiciones ambientales predominantes en cada hábitat de desove. De este modo, las hembras de E. ringens adaptarían sus tácticas reproductivas produciendo tamaño y cantidades de huevos que favorezcan la supervivencia de sus descendientes a las condiciones ambientales en las que se desarrollarán

From Mexico to Beijing: "Women in Development" Twenty Five Years On

During the past twenty five years the Women in Development (WID)approach has become an increasingly important issue in the literature on Third World development. WID issues and related activities have now been incorporated into the aid practice of most development agencies. This paper critically analyses the diverse and conflicting ideologies that have emerged in the WID literature since the early seventies

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Actividad reproductiva y longitud de madurez

The Patagonian sprat, Sprattus fuegensis, has been recently identified in the catches of small pelagic fish in the inland waters of Chiloé, southern Chile. In spite of its increasing economic importance, there are still unknown aspects of its reproductive biology. This study describes the reproductive activity of females of this species based on monthly variation of the Gonadosomatic Index (IGS) and the frequency of macroscopic states of maturity between January of 2006 and December of 2009 and microscopic states since February of 2007. The maturity at length of females was studied during the main spawning season. IGS monthly variation and the frequency of macroscopic states of maturity reached maximum values each year, between September and October, and minimum from January to June. In addition, the histological analysis of the ovaries confirmed that S. fueguensis is a partial spawner whose reproductive activity although tends to concentrate between September and October can be extended to December. The mean length at maturity of females during the reproductive season was 13.5 cm, indicating that they spawned at longer lengths in comparison with the same species from other localities. It is discussed that the increase of the reproductive activity in spring and larger maturity sizes could be part of a reproductive strategy of the species to enhance the survival during early stages in the inland seawater of Chiloé.La sardina austral, Sprattus fuegensis, ha sido recientemente identificada en las capturas de peces pelágicos en el mar interior de Chiloé, sur de Chile. A pesar de su creciente importancia económica aún se desconocen aspectos básicos de su biología reproductiva. Se describe la actividad reproductiva de las hembras de esta especie en base a la variación mensual del Indice Gonadosomático (IGS) y a la frecuencia de estados macroscópicos de madurez ovárica entre enero de 2006 y diciembre de 2009 y de estados microscópicos a partir de febrero de 2007. Se estudia además el proceso de maduración en longitud corporal de las hembras durante la época principal de desove. Cada año, la variación mensual del IGS así como la frecuencia de estados macroscópicos de madurez, revelaron valores máximos entre septiembre y octubre, y mínimos entre enero y junio. El análisis histológico del ovario confirmó que S. fuegensis corresponde a un desovante parcial, cuya actividad reproductiva aunque tiende a concentrarse entre septiembre y octubre, puede extenderse hasta diciembre. La longitud promedio de las hembras maduras durante la estación reproductiva se estimó en 13,5 cm, representando una avanzada longitud de madurez en comparación con otras estimaciones para la especie obtenidas en otras localidades. Se discute que el aumento de la actividad reproductiva en primavera, así como la maduración a mayor tamaño corporal, podrían ser parte de la estrategia reproductiva de la especie, orientada a favorecer la sobrevivencia de sus primeros estadios de vida en aguas del sur de Chile

Photoluminescent properties of lead zirconate powders obtained by the polymeric precursor method

Lead zirconate powders, obtained by the polymeric precursor method, were annealed for 2 h at temperatures from 300 to 800 degrees C. The effect of heat treatment on structural defects and photoluminescent behavior was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Fourier transform Raman spectroscopy (FT-Raman), scanning electron microscopy (SEM), and photoluminescence spectroscopy (PL). XRD patterns and FT Raman spectra showed that the structure of the PbZrO3 powders was orthorhombric. FT-IR spectra exhibited absorption bands at 450 and 860 cm(-1). were ascribed to Zr-O bands and indicate the ZrO6 octahedral group. SEM micrographs suggested that the annealing temperature allowed structural morphology changes in the samples. PbZrO3 powders emitted green photoluminescence at room temperature and at lower annealing temperatures but no photoluminescence was observed from the ordered structure. This optical behavior was attributed to structural evolution from disordered to ordered as a function of PbZrO3 powder annealing. The intensity of the green PL component increased after annealing at 300 degrees C. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Investigation of phase transition in ferroelectric Pb0.70Sr0.30TiO3 thin films

We have carried out dielectric and Raman spectroscopy studies at the 298-623 K temperature range in polycrystalline Pb0.70Sr0.30TiO3 thin films grown by a soft chemical method. The diffuse phase-transition behavior of the thin films was observed by means of the dielectric constant versus temperature curves, which show a broad peak. Such behavior was confirmed later by Raman spectroscopy measurements up to 823 K, indicating that a diffuselike phase transition takes place at around 548-573 K. The damping factor of the E(1TO) soft mode was calculated using the damped simple harmonic oscillator model. on the other hand, Raman modes persist above the tetragonal to cubic phase transition temperature although all optical modes should be Raman inactive. The origin of these modes was interpreted in terms of a breakdown of the microscopic local cubic symmetry by chemical disorder. The lack of a well-defined transition temperature and the presence of broad bands at some temperature interval above the ferroelectric-paraelectric phase-transition temperature suggested a diffuse nature of the phase transition. This result corroborates the dielectric constant versus temperature data, which showed a broad ferroelectric phase transition in this thin film. (C) 2004 American Institute of Physics

Structural phase evolution of strontium-doped lead titanate thin films prepared by the soft chemical technique

Strontium-modified lead titanate thin films with composition Pb1-xSrxTiO3 were grown on Pt/Ti/SiO2/Si substrates using the polymeric precursor method. The structural phase evolution as a function of the Sr contents was studied using micro-Raman scattering, specular reflectance infrared Fourier transform spectroscopy, and x-ray diffraction. The results showed a gradual change from tetragonal to cubic structure, the transition occurring at about x = 0.58. The infrared reflectance spectra showed that the frequency of several peaks decreases as the strontium concentration increases. These features are correlated with a decrease in the tetragonal distortion of the TiO6 octahedra as the strontium concentration increases

Reflux synthesis and hydrothermal processing of ZrO2 nanopowders at low temperature

In this paper, we report on the reflux synthesis at 90 degrees C and hydrothermal processing at 120 degrees C for obtention of zirconium oxide (ZrO2) nanopowders under several conditions. These nanopowders; were characterized by X-ray diffraction (XRD), Fourier transform Raman (FT-Raman) spectroscopy, adsorption-desorption N-2-isotherms, Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA) and field-emission scanning electron microscopy (FE-SEM). XRD patterns and Raman spectra indicated that ZrO2 nanopowders present a monoclinic structure. In addition, the hydrothermal processing promoted an increase in crystallinity of ZrO2 nanopowders. FT-IR spectra revealed a small shoulder on the nu (Zr-O) bands in transmittance spectra of the ZrO2 nanopowders. The decomposition of precursor was accompanied by evolution of TGA curves. The morphology of ZrO2 nanopowders was observed by FEG-SEM. Also, the FEG-SEM micrographs revealed that the presence of H2O2 in systems reduced the particle size, while the absence of promoted an increase in particle size. (C) 2009 Elsevier B.V. All rights reserved.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP