Photocatalytic activity of nanostructured anatase coatings obtained by cold gas spray

[EN] This article describes a photocatalytic nanostructured anatase coating deposited by cold gas spray (CGS) supported on titanium sub-oxide (TiO22x) coatings obtained by atmospheric plasma spray (APS) onto stainless steel cylinders. The photocatalytic coating was homogeneous and preserved the composition and nanostructure of the starting powder. The inner titanium sub-oxide coating favored the deposition of anatase particles in the solid state. Agglomerated nano-TiO2 particles fragmented when impacting onto the hard surface of the APS TiO22x bond coat. The rough surface provided by APS provided an ideal scenario for entrapping the nanostructured particles, which may be adhered onto the bond coat due to chemical bonding; a possible bonding mechanism is described. Photocatalytic experiments showed that CGS nano-TiO2 coating was active for photodegrading phenol and formic acid under aqueous conditions. The results were similar to the performance obtained by competitor technologies and materials such as dip-coating P25 photocatalysts. Disparity in the final performance of the photoactive materials may have been caused by differences in grain size and the crystalline composition of titanium dioxide.

The Hydrogen Atom: The Bohr Model in Detail

The Bohr Model for the Hydrogen Atom's electron is discussed in detail, with a recapitulation of angular momentum and a detailed discussion of relevant units (out of the cgs system).

Paleomagnetic of the Cobb Mountin event sections

Detailed paleomagnetic investigations are reported for 283 specimens, sampled from three closely spaced Ocean Drilling Program Leg 135 cores from the Lau Basin. These specimens cover three rather similar records of the reversed Cobb Mountain short polarity event, having an age of about 1.12 m.y. On the basis of a very detailed subsampling every 0.6 cm, we found that the transition times for the Cobb Mountain geomagnetic polarity event, as seen in the three Lau Basin sediment records, appear to have been as short as 0.6-1.0 k.y., although the duration of the normal-polarity event itself lasted only about 17 ± 4 k.y. The older (R to N) transition as well as the younger (N to R) transition show virtual geomagnetic paths roughly along the Americas, but shifted some 30° ± 10° to the east. These paths conflict with Cobb Mountain transition paths recorded in sediments from the Labrador Sea and the North Atlantic, but they are in fair accordance with sediment records from the Celebes and Sulu seas when corrected for differences in site longitude, suggesting that the transitional fields are dominated by nonaxial, high-order spherical harmonics.

Magnetic properties and oxide petrography of ODP Hole 111-504B

Magnetic properties measurements were performed on 47 samples drilled during Leg 111 of the Ocean Drilling Program and oxide petrography was studied in 32 samples taken at depths throughout the sheeted dike complex in Hole 504B. Integration of these data with results from previous DSDP legs shows that while natural remanent magnetization is constant with depth, magnetic susceptibility increases and median demagnetizing field and the Q ratio decrease with depth in the section. These trends appear to be a result of an increase in deuteric oxidation and a decrease in hydrothermal alteration of primary titanomagnetite with depth. A distinct change in stable magnetic inclination occurs between the extrusive basalts and the sheeted dikes and may be a result of tectonic rotation of the upper extrusive basalts.

Contusotruncana contusa abundances and morphotypes in the cretaceous mid-latitude South Atlantic

Spatial and temporal patterns in test size and shape (test conicity and spiral roundness) and absolute abundance (accumulation rate) of the planktonic foraminifer Contusotruncana contusa were studied in the South Atlantic Ocean (DSDP sites 356, 516, 525 and 527) during an interval corresponding to the last 800 kyr of the Cretaceous. The variation in absolute abundance of C. contusa was characterised by alternating periods of high and low abundance; some of these periods were traceable across the entire mid-latitude South Atlantic Ocean. While the mean spiral roundness did not show any interpretable patterns, a sudden increase of the mean test size and mean test conicity occurred between 65.3 and 65.2 Ma (based on linear interpolation within the Cretaceous part of Subchron C29R) at all sites studied, indicating a poleward migration followed by rapid withdrawal of the low-latitude C. contusa morphotypes from the mid-latitude South Atlantic Ocean. We suggest that this event was caused by a short period of surface-water warming in the southern mid-latitudes corresponding to the brief high-latitude warming event and associated faunal migrations in the Boreal and Austral realms.

La "capacidad de investigación" en un enfoque por competencias : Un estudio en el Instituto de Ciencias Básicas de la UNCuyo

Considerando a la "capacidad de investigación" ("CI") como una "competencia genérica" ("CG") se plantea la pregunta por la importancia que tendrían para su desarrollo las demás CGs establecidas en el Proyecto Tuning para el egreso de cualquier carrera universitaria en América Latina ("AL"). Considerando, además, que el desarrollo de la CI otorga identidad y articula la formación superior en Ciencias Básicas ("CsBs") se plantea la pregunta por la influencia de la investigación en la elección de una carrera en CsBs y por las actividades que pudieren favorecerla. Para abordar ambos problemas se realizó una encuesta a estudiantes de 1er año de la Licenciatura y Profesorado en CsBs con orientaciones Matemática, Física, Química y Biología. En este trabajo se presentan los resultados sobre elección de la carrera, asignaturas y actividades previas que estimularon el interés por las CsBs y la importancia de desarrollar las CGs para el logro de la CI. Los últimos datos se analizan en términos de un esquema para las dimensiones de la formación superior. Las CGs consideradas más importantes son las que involucran las dimensiones cognitiva y metodológica - solas o combinadas - y las que articulan a éstas con las dimensiones actitudinal-valorativa y "de la acción"

La "capacidad de investigación" en un enfoque por competencias : Un estudio en el Instituto de Ciencias Básicas de la UNCuyo

Considerando a la "capacidad de investigación" ("CI") como una "competencia genérica" ("CG") se plantea la pregunta por la importancia que tendrían para su desarrollo las demás CGs establecidas en el Proyecto Tuning para el egreso de cualquier carrera universitaria en América Latina ("AL"). Considerando, además, que el desarrollo de la CI otorga identidad y articula la formación superior en Ciencias Básicas ("CsBs") se plantea la pregunta por la influencia de la investigación en la elección de una carrera en CsBs y por las actividades que pudieren favorecerla. Para abordar ambos problemas se realizó una encuesta a estudiantes de 1er año de la Licenciatura y Profesorado en CsBs con orientaciones Matemática, Física, Química y Biología. En este trabajo se presentan los resultados sobre elección de la carrera, asignaturas y actividades previas que estimularon el interés por las CsBs y la importancia de desarrollar las CGs para el logro de la CI. Los últimos datos se analizan en términos de un esquema para las dimensiones de la formación superior. Las CGs consideradas más importantes son las que involucran las dimensiones cognitiva y metodológica - solas o combinadas - y las que articulan a éstas con las dimensiones actitudinal-valorativa y "de la acción"

La "capacidad de investigación" en un enfoque por competencias : Un estudio en el Instituto de Ciencias Básicas de la UNCuyo

Considerando a la "capacidad de investigación" ("CI") como una "competencia genérica" ("CG") se plantea la pregunta por la importancia que tendrían para su desarrollo las demás CGs establecidas en el Proyecto Tuning para el egreso de cualquier carrera universitaria en América Latina ("AL"). Considerando, además, que el desarrollo de la CI otorga identidad y articula la formación superior en Ciencias Básicas ("CsBs") se plantea la pregunta por la influencia de la investigación en la elección de una carrera en CsBs y por las actividades que pudieren favorecerla. Para abordar ambos problemas se realizó una encuesta a estudiantes de 1er año de la Licenciatura y Profesorado en CsBs con orientaciones Matemática, Física, Química y Biología. En este trabajo se presentan los resultados sobre elección de la carrera, asignaturas y actividades previas que estimularon el interés por las CsBs y la importancia de desarrollar las CGs para el logro de la CI. Los últimos datos se analizan en términos de un esquema para las dimensiones de la formación superior. Las CGs consideradas más importantes son las que involucran las dimensiones cognitiva y metodológica - solas o combinadas - y las que articulan a éstas con las dimensiones actitudinal-valorativa y "de la acción"

Magnetic properties of basalts and sediments of ODP Leg 135 sites

Paleomagnetic and rock-magnetic investigations of basalts from Hole 834B in the Lau backarc basin and of sediments from Holes 841A and 841B at the Tonga Ridge are reported. Three groups of blocking temperatures in the basalts suggest the presence of at least three magnetic phases: pure magnetite, a Ti-poor titanomagnetite, and a Ti-rich phase. The drill-string-induced remanence in the basalts is typically between three and six times the original normal remanent magnetization intensity, but it is mostly removed by alternating-field (AF) cleaning in 5 mT. Volume susceptibility values range from 0.04 * 10**-3 to 4 * 10**-3 cgs. The modified Q-ratio J5/sus ranges from 0.5 to 10. The drill-string-induced remanence behaves different in the two sediment cores from Holes 841A and 841B, which may be the result of differences in the sediment or caused by the different drilling equipment used. The AF-cleaned inclinations of the sediment in Holes 841A and 841B suggest a slight flattening with increasing depth (up to 6° under a load of 400 m of sediment) to be present. This flattening is likely to be caused by the differential rotation of detrital particles under compaction during diagenesis.

Sediment paleomagnetism at DSDP Leg 78 Holes

The results of paleomagnetic studies of samples from DSDP Leg 78A are reported. For Site 541, the interval from 60 to 200 m sub-bottom was correlated with the Matuyama through Gilbert polarity epochs. For Site 543, the interval from 150 to 190 m sub-bottom was correlated with marine magnetic Anomalies 5C through 5E. Down-dip directions of tilted beds inferred from declination values for Sites 541 and 542 suggest a pattern of monoclinal folding. Results from basalt samples are comparable to those from other DSDP sites in relatively old basalts.

Magnetic properties of gabbros from ODP Hole 118-735B

A total of 500.7 m of continuous, vertical, oceanic gabbroic section was recovered during Leg 118. The gabbros obtained exhibited various degrees of alteration and deformation, which gave us a good opportunity to study the magnetic properties of oceanic gabbros. Many of these gabbros, which are mainly Fe-Ti oxide gabbros, have strong and unstable secondary magnetic components that were acquired during drilling. Stable inclinations, which are probably in-situ magnetic directions, show a single polarity, with an average value of 66° (±5°), meaning that the studied 501-m oceanic gabbroic block may be a candidate for the source of the marine magnetic anomaly. This may also imply that the metamorphism of oceanic gabbros causing acquisition of magnetization probably occurred within one geomagnetic polarity chron (about 0.3 to 0.7 m.y.) after these gabbros formed at the ridge, leading us to conclude that oceanic gabbros record the so-called Vine-Matthews-Morley type of initial magnetization at the ridge. The average intensity value of stable magnetic components of individual samples, which may be a minimum estimate for remanent magnetizations, is 1.6 A/m. Assuming this magnetic intensity value and a uniform magnetization within an oceanic gabbroic layer having a thickness of 4.5 km (i.e., whole layer 3), it is possible to explain most of the marine magnetic anomaly. If magnetic properties of the samples obtained from Hole 735B are common to oceanic gabbros, layer 3 may contribute more significantly to seafloor spreading magnetic anomalies than previously thought.

Biostimulation methods associated with early weaning and reproductive rhythms in primiparous rabbit does

El objetivo general de esta Tesis Doctoral ha sido tratar de mejorar los parámetros reproductivos de las conejas primíparas lactantes, empleando dos métodos de manejo (destete temprano y extensificación del ritmo reproductivo), que están directamente relacionados con su balance energético. Para ello, se diseñaron 2 experimentos en este tipo de hembras. En el primero, se estudió el efecto del destete a 25 días post-parto (dpp) sobre la actividad ovárica y el metabolismo energético de las conejas una semana más tarde (32 dpp). Un total de 34 primíparas lactantes con 8 gazapos fueron distribuidas en tres grupos: 10 conejas se sacrificaron a los 25 dpp (grupo L25), 13 fueron destetadas a los 25 dpp y sacrificadas a los 32 dpp (grupo NL32), y 11 conejas no se destetaron y fueron sacrificadas a los 32 dpp (grupo L32). No se observaron diferencias significativas entre grupos en el peso corporal, el peso del ovario, ni en las concentraciones séricas de ácidos grasos no esterificados y de proteínas totales. A pesar de que el grupo NL32 presentó un bajo consumo de alimento (122 ± 23,5 g / día, p <0,001), su contenido corporal estimado de lípidos (16,9 ± 1,09%, P <0,008), proteínas (19,7 ± 0,07%, P <0,0001), y energía (1147 ± 42,7 MJ / kg, p <0,006) fueron más elevados y las concentraciones séricas de glucosa (158 ± 24,5 mg/dl, p <0,04) más bajas que en los grupos L25 (11,9 ± 1,3%, 18,5 ± 0,08%, 942 ± 51,3 MJ/kg y 212 ± 27,9 mg/dl) y L32 (13,4 ± 1,03%, 18,5 ± 0,1%, 993 ± 40,4 MJ/kg y 259 ± 29,5 mg/dl), respectivamente. En el grupo L25 se observó un menor número medio de folículos ≥ 1 mm en la superficie ovárica en comparación con los grupos NL32 y L32 (12,7 ± 1,5 vs. 18,0 ± 1,45 y 17,6 ± 1,67, p <0,05). La población folicular ovárica en las secciones histológicas y la inmunolocalización de los receptores de prolactina fueron similares en todos los grupos. En el grupo L25, tanto la maduración nuclear de oocitos, medida en términos de tasas alcanzadas de Metafase II (67,0 vs. 79,7 y 78,3%, P <0.05) y la maduración citoplasmática, medida por el porcentaje de gránulos corticales (GC) total o parcialmente migrados en los oocitos, fueron significativamente menores que en los grupos NL32 y L32 (16,0 vs 38,3 y 60,0%, P <0.05). En conclusión, a pesar de que el destete precoz a 25 dpp pareció mejorar las reservas de energía de las conejas primíparas, este hecho no se reflejó claramente a nivel ovárico a los 32 dpp y fue similar independientemente del destete, por lo que éste último podría llevarse a cabo más tarde. En el segundo experimento, se compararon dos ritmos reproductivos. Se utilizaron un total de 48 conejas primíparas lactantes con 8 gazapos que se asignaron al azar en dos grupos experimentales: a) lactantes sacrificadas a comienzos del post-parto (11 dpp) de acuerdo a un ritmo semi-intensivo (n = 24), y b) lactantes sacrificadas al final del período post-parto (25 dpp) de acuerdo con un ritmo más extensivo (n = 24). En ellas, se estudió el peso vivo, la composición corporal estimada, parámetros metabólicos y endocrinos (estradiol y progesterona) y características ováricas como la población folicular y la tasa de atresia, así como la maduración nuclear y citoplásmica de los oocitos. En este estudio, el peso vivo, el contenido de energía corporal, los depósitos grasos y los ácidos grasos no esterificados disminuyeron a lo largo del post-parto con respecto al momento del parto (P <0,05). Las concentraciones séricas de proteínas y glucosa aumentaron en el mismo periodo post-parto (P <0,05). Se observaron similares niveles de estradiol y progesterona en ambos ritmos, así como una población folicular, tasas de maduración nuclear (tasa de oocitos en metafase II) y citoplasmática (porcentaje de oocitos con gránulos corticales migrados), similares en ambos momentos del post-parto. Sin embargo, el número de folículos preovulatorios en la superficie ovárica fue menor (P <0,05) y la tasa de atresia tendió a ser mayor con un porcentaje también menor de folículos sanos (P <0,1) en los ovarios de las hembras sometidas al ritmo extensivo. En conclusión, al final del post-parto (25 días), las conejas primíparas sin destetar muestran un deterioro de sus reservas corporales, de sus parámetros metabólicos séricos y de la calidad de sus oocitos; incluso se ha observado una ligera influencia negativa en el desarrollo de sus folículos ováricos. Por esta razón, se considera que en las conejas primíparas lactantes el manejo reproductivo extensivo (25 dpp) no presenta ninguna ventaja en comparación con el semi-intensivo (11 dpp). A la vista de los resultados de estos dos experimentos, podemos decir que ni el destete temprano, ni la extensificación del ritmo reproductivo han conseguido una mejora en los parámetros reproductivos de una hembra primípara. Por ello, son necesarios más estudios sobre el estado metabólico de la coneja primípara lactante para conseguir métodos o estrategias que lo mejoren y tengan consecuencias directas sobre la actividad reproductiva y sobre su éxito productivo. The general aim of this Thesis was to study two management methods (early weaning and extensive reproductive rhythm) linked to the energy balance of the primiparous rabbit does to improve their reproductive performance. In this sense, 2 experiments were conducted using this kind of females. In the first experiment, the effect of weaning at 25 days post-partum (dpp) on ovarian activity and energetic metabolism one week later (32 dpp) was studied. A total of 34 primiparous lactating rabbit does were used and distributed among three groups: 10 does euthanized at 25 dpp (group L25), 13 does weaned at 25 dpp and euthanized at 32 dpp (group NL32), and 11 non weaned does euthanized at 32 dpp (group L32). No significant differences were observed in live body weight, ovary weight, serum non esterified fatty acids (NEFA) and total protein concentration among groups. Although NL32 does had a low feed intake (122±23.5 g/Day; P < 0.001), their estimated lipids (16.9±1.09%, P < 0.008), protein (19.7±0.07%, P < 0.0001), and energy (1147±42.7 MJ/kg, P < 0.006) body contents were higher and their serum glucose concentrations (158±24.5 mg/dl, P < 0.04) were lower compared to L25 does (11.9±1.3%, 18.5±0.08%, 942±51.3 MJ/kg and 212±27.9 mg/dl) and L32 does (13.4±1.03%, 18.5±0.1%, 993±40.4 MJ/kg and 259±29.5 mg/dl, respectively). A lower number of follicles ≥1mm was observed compared to NL32 and L32 groups (12.7±1.5 vs. 18.0±1.45 and 17.6 ±1.67; P < 0.05) in the ovarian surface of L25 does. Follicular population in the histological ovarian sections and immunolocalization of prolactin receptor were similar in all groups. In group L25, both nuclear maturation of oocytes in terms of Metaphase II rate (67.0 vs. 79.7 and 78.3%; P < 0.05) and cytoplasmic maturation measured by percentage of cortical granules (CG), totally or partially migrated in oocytes were significantly lower than in groups NL32 and L32 (16.0 vs. 38.3 and 60.0%; P < 0.05). Consequently, a higher rate of oocytes with non-migrated CGs was found in group L25 than in groups NL32 and L32 (76.0 vs. 46.8 and 33.3%; P < 0.05). In conclusion, even though early weaning at 25 dpp seemed to improve body energy stored in primiparous does, this fact was not well reflected on the ovarian status at 32 dpp, which was similar regardless of weaning time. In the second experiment, two reproductive rhythms were compared. A total of 48 primiparous Californian x New Zealand White rabbit does suckling 8 kits were randomly allocated in two experimental groups: a) lactating does euthanized at early post-partum period (11 dpp) according to a semi-intensive rhythm (n = 24), and b) lactating does euthanized on later post-partum period (25 dpp) according to a more extensive rhythm (n = 24). Live weight, estimated body composition, serum metabolic and endocrine parameters (oestradiol and progesterone concentrations) and ovarian features like follicle population and atresia rate, and oocyte maturation were studied. Live weight, body energy content, lipid depots and serum non esterified fatty acids (NEFA) concentrations diminished from parturition time to post-partum period (P < 0.05). In addition, serum protein and glucose concentrations increased along postpartum time (P < 0.05). Similar oestradiol and progesterone levels were shown in rhythms as well as similar follicle population and nuclear and cytoplasmic maturation rates measured as metaphase II and cortical granule migration, respectively in both postpartum times. However, number of preovulatory follicles on the ovarian surface was lower (P < 0.05) and atresia rate tended to be higher with also lower percentage of healthy follicles (P < 0.1) in ovaries of females of extensive group. In conclusion, primiparous non-weaned rabbits does at late post-partum time (25 days), Did no show any improvement regarding body reserves, serum metabolic parameters and oocyte quality; even a slight negative influence has been observed in the development of their ovarian follicles. Thus this reproductive management does not present any advantage compared to earlier post-partum (11 days) reproductive rhythm. In summary, according to the obtained results from these two experiments, we can say that the application of early weaning and the extensive rhythms did not achieve an improvement in the reproductive performance of primiparous does. Thus, it is necessary to conduct more studies about the metabolic status of the primiparous lactating doe to achieve strategies in order to improve it and consequently, to improve the reproductive activity and their productive success.

Human PEX19: cDNA cloning by functional complementation, mutation analysis in a patient with Zellweger syndrome, and potential role in peroxisomal membrane assembly

At least 11 complementation groups (CGs) have been identified for the peroxisome biogenesis disorders (PBDs) such as Zellweger syndrome, for which seven pathogenic genes have been elucidated. We have isolated a human PEX19 cDNA (HsPEX19) by functional complementation of peroxisome deficiency of a mutant Chinese hamster ovary cell line, ZP119, defective in import of both matrix and membrane proteins. This cDNA encodes a hydrophilic protein (Pex19p) comprising 299 amino acids, with a prenylation motif, CAAX box, at the C terminus. Farnesylated Pex19p is partly, if not all, anchored in the peroxisomal membrane, exposing its N-terminal part to the cytosol. A stable transformant of ZP119 with HsPEX19 was morphologically and biochemically restored for peroxisome biogenesis. HsPEX19 expression also restored peroxisomal protein import in fibroblasts from a patient (PBDJ-01) with Zellweger syndrome of CG-J. This patient (PBDJ-01) possessed a homozygous, inactivating mutation: a 1-base insertion, A764, in a codon for Met255, resulted in a frameshift, inducing a 24-aa sequence entirely distinct from normal Pex19p. These results demonstrate that PEX19 is the causative gene for CG-J PBD and suggest that the C-terminal part, including the CAAX homology box, is required for the biological function of Pex19p. Moreover, Pex19p is apparently involved at the initial stage in peroxisome membrane assembly, before the import of matrix protein.