Uncertainties in fPAR estimation of grass canopies under different stress situations and differences in architecture

The fraction of intercepted photosynthetic active radiation (fPAR) is a key variable used by the Monteith model to estimate the net primary productivity (NPP). This variable can be assessed by vegetation indices (VIs) derived from spectral remote sensing data but several factors usually affect their relationship. The objectives of this work were to analyse the fPAR dynamics and to describe the relationships between fPAR and several indices (normalized difference vegetation index (NDVI), optimized soil adjusted vegetation index (OSAVI), GreenNDVI (GNDVI), visible atmospherically resistant index (VARI) green, VIgreen and red edge position (REP)) under different water and nutrient treatments for two species with different canopy architectures. Two C3 grass species with differences in leaf orientation (planophile and erectophile) were cultivated from seeds in pots. Four treatments were applied combining water and nitrogen availability. Every week, canopy reflectance and fPAR were measured. Aerial biomass was clipped to estimate final above-ground production for each species and treatment. Starting from reflectance values, the indices were calculated. Planophile species have a steeper (but not significantly) slope inVIs-fPAR relationships than the erectophile species. Water and nutrient deficiencies treatment showed no relationship with fPAR in any spectral index in the erectophile species. In the other species, this treatment showed significant relationship according to the index used. Analysing each species individually, treatments did not modify slopes except in one case (planophile species between both treatments with high nitrogen but differing in water availability). Among indices, GNDVI was the best estimator of fPAR for both species, followed by NDVI and OSAVI. Inaccurate results may be obtained from commonly reported spectral relationships if plants' stress factors are not taken into account.Fil: Cristiano, Piedad María. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Clima y Agua; ArgentinaFil: Posse, G.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Clima y Agua; ArgentinaFil: Di Bella, Carlos Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Clima y Agua; ArgentinaFil: Jaimes, Florencia Romina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación de Recursos Naturales. Instituto de Clima y Agua; Argentin

A new building block for polynuclear complexes: The ion [Ru(CN)4(bptz)]2- (bptz = 3,6-Bis(2-pyridyl)-1,2,4,5-tetrazine)

Se reportan la síntesis y las propiedades fisicoquímicas del nuevo complejo mononuclear de rutenio (II), de fórmula Na2[Ru(bptz)(CN)4 ].4H2 O (bptz = 3,6-bis(2-piridil)-1,2,4,5- tetrazina). Los datos espectrales de IR y de UV-visible, junto a las medidas de voltamperometría cíclica, indican que el ligando bptz tiene una capacidad aceptora π - intermedia entre dpp y bpz cuando se coordina a un grupo tetracianorutenato(II) (dpp = 2,3-bis(2’-piridil)pirazina ; bpz = 2,2’-bipirazina). Este complejo puede ser usado como un fotosensibilizador, pues emite a temperatura ambiente en soluciones alcohólicas, y como una unidad estructural para la construcción de nuevos complejos polinucleares, tales como el ion simétrico [(CN)4 Ru(bptz)Ru(CN)4 ]4-, cuya preparación y propiedades espectrales en soluciones acuosas se describen también en este trabajo.The synthesis and physicochemical properties of the new mononuclear ruthenium(II) complex, of formula Na2[Ru(bptz)(CN)4].4H2 O (bptz = 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine)are reported. The IR and UV-vis spectral data, together with cyclic voltammetrymeasurements, indicate that the ligand bptz has a π -acceptor ability intermediate betweendpp and bpz when coordinated to the tetracyanoruthenate(II) moiety (dpp = 2,3-bis(2’- pyridyl)pyrazine ; bpz = 2,2’-bipyrazine). This complex can be used as a photosensitizer,since it emits at room temperature in alcoholic solutions, and as a building block for new polynuclear complexes, such as the symmetric ion [(CN)4 Ru(bptz)Ru(CN)4]4-, whose preparation and spectral properties in aqueous solutions are also described in this work.Fil: García Posse, Mónica Ema. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Física; ArgentinaFil: Vergara, Monica Mercedes. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Física; ArgentinaFil: Fagalde, Florencia. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; ArgentinaFil: Mellace, María G.. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Física; ArgentinaFil: Katz, Néstor Eduardo. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; Argentin

When prosthetic joint infection may lead to premalignant colorectal lesion detection

Osteoarthritis (OA) is a common musculoskeletal disorder that affects millions of people worldwide, and total knee arthroplasty (TKA) is a common treatment for advanced OA. However, joint replacement surgeries may lead to complications such as deep vein thrombosis (DVT), surgical site infection, and prosthetic joint infection (PJI). Our objective is to discuss a Streptococcus bovis group (SBG) PJI case after TKA and its possible consequences in clinical practice. We describe a 67-year-old female who underwent TKA and developed initial complications including wound hematoma, symptomatic anemia, and acute DVT. Further investigations because of knee pain persistence and inflammatory signs post TKA revealed the presence of Staphylococcus aureus in the synovial and scar tissues from the knee and SBG in the periprosthetic membrane from the revision surgery, as well as mitral infective endocarditis and a large stenosing villous polypoid lesion in the ascending colon. SBG osteoarticular infection post TKA is a rare condition, but it may be associated with severe diseases. This article highlights the link between SBG and colorectal cancer (CRC) and emphasizes the importance of an echocardiogram and a colonoscopy for early detection and prompt treatment of infective endocarditis and CRC. This diagnostic workup should be performed even in the absence of symptoms, for early diagnosis and increased chance of cure. A multidisciplinary approach, involving orthopedists, infectious disease specialists, cardiologists, and gastroenterologists, among others, is advised to effectively manage SBG infections and improve patient outcomes

El Sistema Antártico

Fil: Gutiérrez Posse, Hortensia D. T.. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Derecho Internacional Público. Buenos Aires, ArgentinaFil: Gutiérrez Posse, Hortensia D. T. Universidad de Buenos Aires. Facultad de Derecho. Cátedra Derecho Internacional Humanitario. Buenos Aires, ArgentinaFil: Alonso, Gabriela Liliana. Universidad de Buenos Aires. Facultad de Derecho. Buenos Aires, ArgentinaFil: Breier, Ingrid E. Universidad de Buenos Aires. Facultad de Derecho. Buenos Aires, ArgentinaFil: Cabrera Felisoni, Patricio O. Universidad de Buenos Aires. Facultad de Derecho. Buenos Aires, ArgentinaFil: González, Ariel W. Universidad de Buenos Aires. Facultad de Derecho. Buenos Aires, ArgentinaFil: Jorquera, Mario. Universidad de Buenos Aires. Facultad de Derecho. Buenos Aires, ArgentinaFil: Rizzo Alonso, Hermán G. Universidad de Buenos Aires. Facultad de Derecho. Buenos Aires, ArgentinaEn el marco del ciclo profesional orientado se desarrolló durante 1989 un curso de actualización sobre el sistema antártico. Tenía por objetivo no sólo la profundización de los conocimientos sino también brindar la ocasión de que se ensayasen técnicas de investigación. Los trabajos que a continuación se publican reflejan resultados logrados por alumnos de ese curso. Ellos abordan distintos aspectos de una compleja cuestión que interesa directamente a nuestro país.\n\nPrólogo / Hortensia D. T. Gutiérrez Posse. El Sistema Antártico como régimen objetivo / Gabriela Liliana Alonso. Necesidad de su preservación para salvaguarda de la paz mundial / Ingrid E. Breier. Conservación y protección del medio ambiente antártico / Patricio O. Cabrera Felisoni. Los recursos minerales en el marco del Sistema Antártico : algunas reflexiones / Ariel Walter González. Evolución de los presupuestos jurídicos del Sistema Antártico / Mario Jorquera. Año 1991 y la soberanía en la Antártida, de condición a objetivo / Hernán G. Rizzo Alonso.\

Measuring or estimating greenhouse gas emissions techniques

La disponibilidad de técnicas objetivas para medir o predecir las emisiones de gases de efecto invernadero (GEI) es fundamental para el desarrollo de trabajos de investigación y de gestión de las emisiones de GEI en los sistemas agropecuarios. Existe una variada disponibilidad de técnicas e instrumentos que permiten abordar estudios a nivel ruminal, tales como las técnicas in vitro, o a escala de animal o incluso de rodeo (e.g. cámaras de respiración, torres micrometeorologicas). En este capítulo se describen diferentes técnicas utilizadas para obtener indicadores de las emisiones de GEI, y se explica brevemente la estrategia de cálculo de los inventarios nacionales.Fil: Jaurena, Gustavo. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Juliarena, María Paula. Universidad Nacional del Centro de la Provincia de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Errecart, Pedro. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; ArgentinaFil: Arroquy, Jose Ignacio. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Buenos Aires Sur. Estacion Experimental Agropecuaria Cesareo Naredo.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Berone, Germán Darío. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Posse, G.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Ricci, Patricia. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Producción y Sanidad Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Wide-Angle Seismic Imaging of Two Modes of Crustal Accretion in Mature Atlantic Ocean Crust

We present a high‐resolution 2‐D P‐wave velocity model from a 225‐km‐long active seismic profile, collected over ~60–75 Ma central Atlantic crust. The profile crosses five ridge segments separated by a transform and three nontransform offsets. All ridge discontinuities share similar primary characteristics, independent of the offset. We identify two types of crustal segment. The first displays a classic two‐layer velocity structure with a high gradient Layer 2 (~0.9 s$^{−1}$) above a lower gradient Layer 3 (0.2 s$^{−1}$). Here, PmP coincides with the 7.5 km s$^{−1}$ contour, and velocity increases to >7.8 km s$^{−1}$ within 1 km below. We interpret these segments as magmatically robust, with PmP representing a petrological boundary between crust and mantle. The second has a reduced contrast in velocity gradient between the upper and lower crust and PmP shallower than the 7.5 km s$^{−1}$ contour. We interpret these segments as tectonically dominated, with PmP representing a serpentinized (alteration) front. While velocity‐depth profiles fit within previous envelopes for slow‐spreading crust, our results suggest that such generalizations give a misleading impression of uniformity. We estimate that the two crustal styles are present in equal proportions on the floor of the Atlantic. Within two tectonically dominated segments, we make the first wide‐angle seismic identifications of buried oceanic core complexes in mature (>20 Ma) Atlantic Ocean crust. They have a ~20‐km‐wide “domal” morphology with shallow basement and increased upper crustal velocities. We interpret their midcrustal seismic velocity inversions as alteration and rock‐type assemblage contrasts across crustal‐scale detachment faults

Predictors of linkage to care following community-based HIV counseling and testing in rural Kenya

Despite innovations in HIV counseling and testing (HCT), important gaps remain in understanding linkage to care. We followed a cohort diagnosed with HIV through a community-based HCT campaign that trained persons living with HIV/AIDS (PLHA) as navigators. Individual, interpersonal, and institutional predictors of linkage were assessed using survival analysis of self-reported time to enrollment. Of 483 persons consenting to follow-up, 305 (63.2%) enrolled in HIV care within 3 months. Proportions linking to care were similar across sexes, barring a sub-sample of men aged 18–25 years who were highly unlikely to enroll. Men were more likely to enroll if they had disclosed to their spouse, and women if they had disclosed to family. Women who anticipated violence or relationship breakup were less likely to link to care. Enrolment rates were significantly higher among participants receiving a PLHA visit, suggesting that a navigator approach may improve linkage from community-based HCT campaigns.Vestergaard Frandse

Imaging Mass Spectrometry Detection of Gangliosides Species in the Mouse Brain following Transient Focal Cerebral Ischemia and Long-Term Recovery

Gangliosides, a member of the glycosphingolipid family, are heterogeneously expressed in biological membranes and are particularly enriched within the central nervous system. Gangliosides consist of mono- or poly-sialylated oligosaccharide chains of variable lengths attached to a ceramide unit and are found to be intimately involved in brain disease development. The purpose of this study is to examine the spatial profile of ganglioside species using matrix-assisted laser desorption/ionization (MALDI) imaging (IMS) following middle cerebral artery occlusion (MCAO) reperfusion injury in the mouse. IMS is a powerful method to not only discriminate gangliosides by their oligosaccharide components, but also by their carbon length within their sphingosine base. Mice were subjected to a 30 min unilateral MCAO followed by long-term survival (up to 28 days of reperfusion). Brain sections were sprayed with the matrix 5-Chloro-2-mercaptobenzothiazole, scanned and analyzed for a series of ganglioside molecules using an Applied Biosystems 4800 MALDI TOF/TOF. Traditional histological and immunofluorescence techniques were performed to assess brain tissue damage and verification of the expression of gangliosides of interest. Results revealed a unique anatomical profile of GM1, GD1 and GT1b (d18∶1, d20∶1 as well as other members of the glycosphingolipid family). There was marked variability in the ratio of expression between ipsilateral and contralateral cortices for the various detected ganglioside species following MCAO-reperfusion injury. Most interestingly, MCAO resulted in the transient induction of both GM2 and GM3 signals within the ipsilateral hemisphere; at the border of the infarcted tissue. Taken together, the data suggest that brain region specific expression of gangliosides, particularly with respect to hydrocarbon length, may play a role in neuronal responses to injury