Regulation of XMyoDa transcription by the binding of XMEF2A to the TATA box

MEF2 is a $\underline{\rm m}$yocyte-specific $\underline{\rm e}$nhancer-binding $\underline{\rm f}$actor that binds a conserved DNA sequence, CTA(A/T)$\sb4$TAG. A MEF2 binding site in the XMyoDa promoter overlaps with the TATA box and is required for muscle specific expression. To examine the potential role of MEF2 in the regulation of MyoD transcription during early development, the appearance of MEF2 binding activity in developing Xenopus embryos was analyzed with the electrophoretic mobility shift assay. Two genes were isolated from a X. Laevis stage 24 cDNA library that encode factors that bind the XMyoDa TFIID/MEF2 site. Both genes are highly homologous to each other, belong to the MADS ($\underline{\rm M}$CM1-$\underline{\rm A}$rg80-agamous-$\underline{\rm d}$eficiens-$\underline{\rm S}$RF) protein family, and most highly related to the mammalian MEF2A gene, hence they are designated as XMEF2A1 and XMEF2A2. Proteins encoded by both cDNAs form specific complexes with the MEF2 binding site and show the same binding specificity as the endogenous MEF2 binding activity. XMEF2A transcripts accumulate preferentially in developing somites after the appearance of XMyoD transcripts. XMEF2 protein begins to accumulate in somites at tailbud stages. Transcriptional activation of XMyoD promoter by XMEF2A required only the MADS box and MEF2-specific domain when XMEF2A is bound at the TATA box. However, a different downstream transactivation domain was required when XMEF2A activates transcription through binding to multiple upstream sites. These results suggest that different activation mechanisms are involved, depending on where the factor is bound. Mutations in several basic amino acid clusters in the MADS box inhibit DNA binding suggesting these amino acids are essential for DNA binding. Mutation of Thr-20 and Ser-36 to the negatively charged amino acid residue, aspartic acid, abolish DNA binding. XMEF2A activity may be regulated by phosphorylation of these amino acids. A dominant negative mutant was made by mutating one of the basic amino acid clusters and deleting the downstream transactivation domain. In vivo roles of MEF2 in the regulation of MyoD transcription were investigated by overexpression of wild type MEF2 and dominant negative mutant of XMEF2A in animal caps and assaying for the effects on the level of expression of MyoD genes. Overexpression of MEF2 activates the transcription of endogenous MyoD gene family while expression of a dominant negative mutant reduces the level of transcription of XMRF4 and myogenin genes. These results suggest that MEF2 is downstream of MyoD and Myf5 and that MEF2 is involved in maintaining and amplifying expression of MyoD and Myf5. MEF2 is upstream of MRF4 and myogenin and plays a role in activating their expression. ^

Evolution of Melt Pond Volume on the Surface of the Greenland Ice Sheet

The presence of surface meltwater on ice caps and ice sheets is an important glaciological and climatological characteristic. We describe an algorithm for estimating the depth and hence volume of surface melt ponds using multispectral ASTER satellite imagery. The method relies on reasonable assumptions about the albedo of the bottom surface of the ponds and the optical attenuation characteristics of the ponded meltwater. We apply the technique to sequences of satellite imagery acquired over the western margin of the Greenland Ice Sheet to derive changes in melt pond extent and volume during the period 2001 - 2004. Results show large intra- and interannual changes in ponded water volumes, and large volumes of liquid water stored in extensive slush zones.

S-nitroso albumin enhances bone formation in a rabbit calvaria model.

Nitric oxide (NO) is a mediator involved in bone regeneration. We therefore examined the effect of the novel NO donor, S-nitroso human serum albumin (S-NO-HSA) on bone formation in a rabbit calvaria augmentation model. Circular grooves (8 mm diameter, two per animal) were created by a trephine drill in the cortical bone of 40 rabbits and titanium caps were placed on the rabbit calvaria bone filled with a collagen sponge soaked with either 100 μL S-NO-HSA (5%, 20%) or human albumin (5%, 20%). After 4 weeks the titanium hemispheres were subjected to histological and histomorphometric analysis. Bone formation and the volume of the residual collagen sponge were evaluated. S-NO-HSA treatment groups had a significantly higher volume of newly formed bone underneath the titanium hemispheres compared to the albumin control groups (5%: 15.5 ± 4.0% versus 10.6 ± 2.9%; P < 0.05; 20%: 14.0 ± 4.6% versus 6.0 ± 3.8%; P < 0.01). The volume of residual collagen sponge was also significantly lower in the S-NO-HSA groups compared to the control groups (5%: 0.4 ± 0.5% versus 2.6 ± 2.4%; P < 0.05 and 20%: 1.5 ± 2.7% versus 13.0 ± 18.7%; P < 0.01). This study demonstrates for the first time that S-NO-HSA promotes bone formation by slow NO release. Additionally, S-NO-HSA increases collagen sponge degradation.

Fractures in Children and Adolescents

Fractures of the growing bone require fixation techniques, which preclude any injury to the growth plate regions. This requirement is met by Elastic Stable Intramedullary Nails (ESIN) which are positioned between both metaphyseal regions. Pronounced malposition and/or shortening, open fractures and fractures with impending skin perforation are indications for clavicle nailing in adolescents. Retrograde nailing with two elastic nails, inserted from lateral, is the method of choice for stabilization of humerus fractures. In radial neck fractures with severe tilting of the radial head, a retrograde nail may reduce and fix the head. In Monteggia lesions, the ulna fracture is reduced and fixed with an antegrade nail. Forearm fractures with unacceptable axial deviation are reduced and fixed with one antegrade nail in the ulna and a retrograde nail in the radius. Ascending elastic nailing is done for femur shaft and proximal femur fractures. The medial and lateral entry sites are located above the distal physis. End caps are used to prevent shortening in spiral and multiple segment fractures. Fractures of the distal third of the femur are nailed in a descending technique. The entry sites of two nails are located on the lateral cortex below the greater trochanter. Combined tibia and fibula fractures, open fractures and unstable fracture types such as spiral and multifragmental tibia fractures are good indications for ESIN. Descending nailing is the method of choice. The nail entry points are medially and laterally distal to the apophysis of the proximal tibia. Thorough knowledge of each fracture type, fracture location and age specific healing pattern is necessary for safe and effective treatment of pediatric fractures

Scaling the Costs of 404 Testing to Fit the Needs of Small Public Companies

In July of 2002, the Sarbanes-Oxley Act was passed by Congress, including section 404 which requires the auditors to test and opine on the company's internal controls. Since that time there has been much debate about whether the intended benefits of increased investor confidence and financial statement transparency trump the unexpectedly high compliance costs, especially for public companies with market-caps less than $75 million. Before these companies begin complying in the upcoming year, interest groups are calling for the requirements to be 'scaled' to better fit the needs of these companies. While auditors already are expected to scale their audit approach to each individual client, more must be done to significantly decrease the costs in order to reverse the trend of small companies foregoing listing on U.S. capital markets. Increased guidance from the PCAOB, SEC, and other related parties could help the small-cap companies and their auditors be aware of best practices. Also, exempting industries that already follow similar guidelines or are significantly injured by the compliance requirements could help. Lastly, the controversial proposal of rotational audits could be put in place if the affected parties cooperate to remove the undue burden on these small-cap companies. Without some form of significant action, the investors could soon lose the ability to buy small-cap companies in U.S. markets.

Sexualidad y Ciencias Sociales: aportes al campo de la salud. 16H287

1) Profundizar el marco teórico: revisión bibliográfica, reuniones de discusión y reflexión, informes de texto. Elaboración de documentos internos para trabajar con los becarios y auxiliares según los ejes temáticos seleccionados: GENERO Y SEXUALIDAD. 2) Revisión y análisis de los documentos técnicos de planes y programas seleccionados: Plan Mamá, Plan Nacer y Programa de Salud Sexual y Reproductiva. 3) Desarrollo del trabajo de campo en Posadas: finalización de las actividades en los CAPS y continuidad con el grupo de promotoras Progen (barrios San Jorge y Santa Ceciia). 4) Elaboración de una serie de documentos de trabajo individuales según rol desempeñado y tiempo abocado al proyecto (adscriptos, becarios auxiliares y de iniciación, de postgrado, integrantes docentes). 5) Participación en reuniones y congresos científicos. 6) Redacción de artículos para publicar y/o publicados. 7) Apoyo en la presentación de los integrantes a convocatorias de becas de investigación, nacionales y provinciales. 8) Participación en diversas actividades de extensión y transferencia.

(Table 1) Boron-isotope measurements of shallow-dwelling planktonic foraminifera of ODP Holes 144-817A, 144-872C and 143-865C

Knowledge of the evolution of atmospheric carbon dioxide concentrations throughout the Earth's history is important for a reconstruction of the links between climate and radiative forcing of the Earth's surface temperatures. Although atmospheric carbon dioxide concentrations in the early Cenozoic era (about 60 Myr ago) are widely believed to have been higher than at present, there is disagreement regarding the exact carbon dioxide levels, the timing of the decline and the mechanisms that are most important for the control of CO2 concentrations over geological timescales. Here we use the boron-isotope ratios of ancient planktonic foraminifer shells to estimate the pH of surface-layer sea water throughout the past 60 million years, which can be used to reconstruct atmospheric CO2 concentrations. We estimate CO2 concentrations of more than 2,000 p.p.m. for the late Palaeocene and earliest Eocene periods (from about 60 to 52 Myr ago), and find an erratic decline between 55 and 40 Myr ago that may have been caused by reduced CO2 outgassing from ocean ridges, volcanoes and metamorphic belts and increased carbon burial. Since the early Miocene (about 24 Myr ago), atmospheric CO2 concentrations appear to have remained below 500 p.p.m. and were more stable than before, although transient intervals of CO2 reduction may have occurred during periods of rapid cooling approximately 15 and 3 Myr ago.

Ice loss in the Canadian Arctic Archipelago

Though much attention has been focused in recent years on the melting of ice from Greenland and Antarctica, nearly half of the ice volume currently being lost to the ocean is actually coming from other mountain glaciers and ice caps. Ice loss from a group of islands in northern Canada accounts for much of that volume. In a study published in April 2011 in the journal Nature, a team of researchers led by Alex Gardner of the University of Michigan found that land ice in both the northern and southern Canadian Arctic Archipelago has declined sharply. The maps above show ice loss from surface melting for the northern portion of the archipelago from 2004-2006 (left) and 2007-2009 (right). Blue indicates ice gain, and red indicates ice loss. In the six years studied, the Canadian Arctic Archipelago lost an average of approximately 61 gigatons of ice per year. (A gigaton is a billion tons of ice.) The research team also found the rate of ice loss was accelerating. From 2004 to 2006, the average mass loss was roughly 31 gigatons per year; from 2007 to 2009, the loss increased to 92 gigatons per year. Gardner and colleagues used three independent methods to assess ice mass, all of which showed the same trends. The team used a model to estimate the surface mass balance of ice and the amount of ice discharged. They also compiled and analyzed measurements from NASA's Ice, Cloud and Land Elevation Satellite (ICESat) to assess changes in the surface height of ice. Finally, they gathered observations from NASA's Gravity Recovery and Climate Experiment (GRACE) to determine changes in the gravity field in the region, an indicator of the amount of ice gained or lost. The Canadian Arctic Archipelago generally receives little precipitation, and the amount of snowfall changes little from year to year. But the rate of snow and ice melting varies considerably, so changes in ice mass come largely from changes in summertime melt. During the 2004 to 2009 study period, the Canadian Arctic Archipelago experienced four of its five warmest years since 1960, likely fueling the melting. Gardner notes that from 2001 to 2004, the sum of melting from all mountain glaciers and ice caps around the world (but not the Greenland and Antarctic ice sheets) contributed an estimated 1 millimeter per year to global sea level rise. Recent estimates suggest the Greenland and Antarctic ice sheets add another 1.3 millimeters per year to sea level. "This means 1 percent of the land ice volume-mountain glaciers and ice caps-account for about half of all ice loss to the world's oceans," Gardner said. "Most of the ice loss is coming from the Canadian Arctic Archipelago, Alaska, Patagonia, the Himalayas, and the smaller ice masses surrounding the main Greenland and Antarctic ice sheets."

Saber sobre el Virus del Papiloma Humano en la atención de jóvenes : Estudio en Centros de Atención Primaria de Salud del municipio de La Plata

En nuestro país, en 2011 se incorpora al calendario la vacuna del HPV (virus del papiloma humano) para las niñas de 11 años. Este evento acompaña la preocupación -a nivel mundial- vinculada a la incidencia del cáncer de cuello de útero, el que ocupa el segundo lugar como causa de muerte por cáncer en mujeres. La prevención pone en foco a niñas que aún no han iniciado las relaciones sexuales, cuestión que además de 'instalar' problemas relativos a la sexualidad en ese grupo etario, intersecta las especialidades médicas. En este trabajo interesa indagar el modo en que los profesionales de la salud (principalmente ginecólogos y obstétricas) de los Centros de Atención Primaria de la Salud (CAPS) abordan esta problemática en la consulta de jóvenes mayoritariamente no cubiertas por la vacuna. Considerando las limitaciones -ampliamente reconocidas- presentes en la atención de la salud sexual y reproductiva de jóvenes por parte de los equipos de salud, interesa indagar el lugar que ocupa el HPV en la atención de esta población y el modo en que los profesionales de los CAPS plantean el diagnóstico, tratamiento y prevención. Asimismo, plantea una aproximación cualitativa entrevistando a aquellos profesionales del equipo de salud que se consideran competentes en el tema, por medio de un cuestionario semiestructurado

Saber sobre el Virus del Papiloma Humano en la atención de jóvenes : Estudio en Centros de Atención Primaria de Salud del municipio de La Plata

En nuestro país, en 2011 se incorpora al calendario la vacuna del HPV (virus del papiloma humano) para las niñas de 11 años. Este evento acompaña la preocupación -a nivel mundial- vinculada a la incidencia del cáncer de cuello de útero, el que ocupa el segundo lugar como causa de muerte por cáncer en mujeres. La prevención pone en foco a niñas que aún no han iniciado las relaciones sexuales, cuestión que además de 'instalar' problemas relativos a la sexualidad en ese grupo etario, intersecta las especialidades médicas. En este trabajo interesa indagar el modo en que los profesionales de la salud (principalmente ginecólogos y obstétricas) de los Centros de Atención Primaria de la Salud (CAPS) abordan esta problemática en la consulta de jóvenes mayoritariamente no cubiertas por la vacuna. Considerando las limitaciones -ampliamente reconocidas- presentes en la atención de la salud sexual y reproductiva de jóvenes por parte de los equipos de salud, interesa indagar el lugar que ocupa el HPV en la atención de esta población y el modo en que los profesionales de los CAPS plantean el diagnóstico, tratamiento y prevención. Asimismo, plantea una aproximación cualitativa entrevistando a aquellos profesionales del equipo de salud que se consideran competentes en el tema, por medio de un cuestionario semiestructurado

Saber sobre el Virus del Papiloma Humano en la atención de jóvenes : Estudio en Centros de Atención Primaria de Salud del municipio de La Plata

En nuestro país, en 2011 se incorpora al calendario la vacuna del HPV (virus del papiloma humano) para las niñas de 11 años. Este evento acompaña la preocupación -a nivel mundial- vinculada a la incidencia del cáncer de cuello de útero, el que ocupa el segundo lugar como causa de muerte por cáncer en mujeres. La prevención pone en foco a niñas que aún no han iniciado las relaciones sexuales, cuestión que además de 'instalar' problemas relativos a la sexualidad en ese grupo etario, intersecta las especialidades médicas. En este trabajo interesa indagar el modo en que los profesionales de la salud (principalmente ginecólogos y obstétricas) de los Centros de Atención Primaria de la Salud (CAPS) abordan esta problemática en la consulta de jóvenes mayoritariamente no cubiertas por la vacuna. Considerando las limitaciones -ampliamente reconocidas- presentes en la atención de la salud sexual y reproductiva de jóvenes por parte de los equipos de salud, interesa indagar el lugar que ocupa el HPV en la atención de esta población y el modo en que los profesionales de los CAPS plantean el diagnóstico, tratamiento y prevención. Asimismo, plantea una aproximación cualitativa entrevistando a aquellos profesionales del equipo de salud que se consideran competentes en el tema, por medio de un cuestionario semiestructurado

Black shales from the Upper Aptian and Lower Albanian of the Volcontian Basin

Calcareous nannoplankton, palynomorph, benthic foraminifera, and oxygen isotope records from the supraregionally distributed Niveau Paquier (Early Albian age, Oceanic Anoxic Event 1b) and regionally distributed Niveau Kilian (Late Aptian age) black shales in the Vocontian Basin (SE France) exhibit variations that reflect paleoclimatic and paleoceanographic changes in the mid-Cretaceous low latitudes. To quantify surface water productivity and temperature changes, nutrient and temperature indices based on calcareous nannofossils were developed. The nutrient index strongly varies in the precessional band, whereas variations of the temperature index reflect eccentricity. Since polar ice caps were not present during the mid-Cretaceous, these variations probably result from feedback mechanisms within a monsoonal climate system of the mid-Cretaceous low latitudes involving warm/humid and cool/dry cycles. A model is proposed that explains the formation of mid-Cretaceous black shales through monsoonally driven changes in temperature and evaporation/precipitation patterns. The Lower Albian Niveau Paquier, which has a supraregional distribution, formed under extremely warm and humid conditions when monsoonal intensity was strongest. Bottom water ventilation in the Vocontian Basin was diminished, probably due to increased precipitation and reduced evaporation in regions of deep water formation at low latitudes. Surface water productivity in the Vocontian Basin was controlled by the strength of monsoonal winds. The Upper Aptian Niveau Kilian, which has a regional distribution only, formed under a less warm and humid climate than the Niveau Paquier. Low-latitude deep water formation was reduced to a lesser extent and/or on regional scale only. The threshold for the formation of a supraregional black shale was not reached. The intensity of increases in temperature and humidity controlled whether black shales developed on a regional or supraregional scale. At least in the Vocontian Basin, the increased preservation of organic matter at the sea floor was more significant in black shale formation than the role of enhanced productivity.

Global glacier changes

Changes in glaciers and ice caps provide some of the clearest evidence of climate change, and as such they constitute key variables for early detection strategies in global climate-related observations. These changes have impacts on global sea level fluctuations, the regional to local natural hazard situation, as well as on societies dependent on glacier meltwater. Internationally coordinated collection and publication of standardised information about ongoing glacier changes was initiated back in 1894. The compiled data sets on the global distribution and changes in glaciers and ice caps provide the backbone of the numerous scientific publications on the latest findings about surface ice on land. Since the very beginning, the compiled data has been published by the World Glacier Monitoring Service and its predecessor organisations. However, the corresponding data tables, formats and meta-data are mainly of use to specialists.

Hydrogen isotope composition of pore waters and interlayer water in sediments of ODP Leg 129 holes

Hydrogen isotope compositions have been measured on pore waters from sediments of Leg 129 sites in the Pigafetta and East Mariana basins (central western Pacific). Total water (pore + sorbed waters) contents and their dD have been analyzed for three samples that contain smectite but no zeolite so that sorbed water can be attributed to interlayer water. The H budget for pore and total waters implies that interlayer water is 20 per mil to 30 per mil depleted in D compared to pore water. Because the interlayer/total water molar ratio (0.25 to 0.5) in smectitic sediments is very high, interlayer water represents an important reservoir of D-depleted water in sediments. dD depth profiles for pore water at Sites 800 and 801 show breaks related to chert and radiolarite layers and are relatively vertical below. Above these chert units, pore waters are similar to modern seawater but below, they are between -10 per mil and -5.5 per mil. These values could represent little modified pre-Miocene seawater values, which were D-depleted because of the absence of polar caps, and were preserved from diffusive exchange with modern seawater by the relatively impermeable overlying chert layers. At Site 802, dD values of the pore waters show a decrease in the Miocene tuffs from 0 per mil values at the top to -8 per mil at 250 mbsf. Below, dD values are relatively uniform at about -8ë. Miocene tuffs are undergoing low water/rock alteration. A positive covariation of dD and Cl content of pore water in the tuffs suggests that the increase of dD values could result from secondary smectite formation. Low diffusive exchange coupled with D enrichment due to alteration of preglacial waters could explain the observed profile.

Miocene stable isotope record of ODP Hole 162-982B

Oxygen and carbon isotope records are presented for the benthic foraminifer Cibicidoides wuellerstorfi from upper middle through lower upper Miocene (11.6-8.2 Ma) sediments recovered at intermediate water depth (1134 m) at Ocean Drilling Program Site 982 on Rockall Plateau. Oxygen isotopic values generally lighter than those for the Holocene indicate significantly warmer intermediate waters and/or less global ice volume during the late middle to early late Miocene than at the present. The most depleted oxygen isotope values occurred at around 10.5 Ma. After this time a long-term increase in d18O suggests a gradual increase in global ice volume and/or cooling of intermediate waters during the late Miocene. Comparison of the intermediate depth benthic foraminiferal carbon isotope record from Site 982 and records from various North Atlantic deep sites shows that intermediate waters were generally better ventilated than deep waters between 11.6 and 9.6 Ma. During this time period, increased ventilation of intermediate waters was linked to cooling or the build up of polar ice caps. The Mi events originally proposed by Miller et al. (1991, doi:10.1029/90JB02015) and Wright and Miller (1992, doi:10.2973/odp.proc.sr.120.193.1992) are difficult to identify with certainty in sediments sampled at high resolution (<10**4 year). Comparison of the high-resolution benthic d18O records from ODP Site 982 with the low-resolution benthic d18O record from Monte Gibliscemi (Mediterranean) show that Mi events, if real, may not be of importance as a stratigraphic tool in upper Miocene sedimentary sequences.