Metabolic fate of fructose ingested with and without glucose in a mixed meal.

Ingestion of pure fructose stimulates de novo lipogenesis and gluconeogenesis. This may however not be relevant to typical nutritional situations, where fructose is invariably ingested with glucose. We therefore assessed the metabolic fate of fructose incorporated in a mixed meal without or with glucose in eight healthy volunteers. Each participant was studied over six hours after the ingestion of liquid meals containing either 13C-labelled fructose, unlabeled glucose, lipids and protein (Fr + G) or 13C-labelled fructose, lipids and protein, but without glucose (Fr), or protein and lipids alone (ProLip). After Fr + G, plasma 13C-glucose production accounted for 19.0% ± 1.5% and 13CO2 production for 32.2% ± 1.3% of 13C-fructose carbons. After Fr, 13C-glucose production (26.5% ± 1.4%) and 13CO2 production (36.6% ± 1.9%) were higher (p < 0.05) than with Fr + G. 13C-lactate concentration and very low density lipoprotein VLDL 13C-palmitate concentrations increased to the same extent with Fr + G and Fr, while chylomicron 13C-palmitate tended to increase more with Fr + G. These data indicate that gluconeogenesis, lactic acid production and both intestinal and hepatic de novo lipogenesis contributed to the disposal of fructose carbons ingested together with a mixed meal. Co-ingestion of glucose decreased fructose oxidation and gluconeogenesis and tended to increase 13C-pamitate concentration in gut-derived chylomicrons, but not in hepatic-borne VLDL-triacylglycerol (TG). This trial was approved by clinicaltrial. gov. Identifier is NCT01792089

Impaired radial artery compliance in normotensive subjects with familial hypercholesterolemia

Hypercholesterolemia impairs arteriolar dilatation, but whether the vascular abnormalities accompanying this condition include large artery function is unknown. We addressed this issue in 13 normotensive subjects with familial hypercholesterolemia (serum cholesterol 401.6 \ub1 16.9 mg/dl, mean \ub1 S.E., FHC) and no evidence of atherosclerotic lesions, in whom radial artery (RA) diameter and blood pressure (BP) were measured beat to beat by an echotracking and a Finapres device, respectively. RA compliance (RAG) was derived from the diameter/BP relationship and expressed over the systo-diastolic BP range, both at baseline and after a 12-min brachial artery occlusion. RAC was expressed also as the area under the RAC/BP curve divided for pulse BP. Measurements included maximal forearm blood flow (plethysmography) and minimal forearm vascular resistance (FVR) which were obtained from the values following the 12-min brachial arterial occlusion. Data were collected before and after 6- and 24-month lipid lowering treatment (simvastatin 40 mg/day). Ten age-matched normotensive normocholesterolemic healthy subjects (N) served as controls. Compared to N, baseline RAC was strikingly reduced in FHC (-53.5%, P < 0.01). After ischemia RAC increased significantly and markedly in N (+38.7, P < 0.01), while only a modest and non-significant increase was observed in FHC. Minimal FVR was markedly higher in FHC than in N (3.5 \ub1 0.9 vs 1.6 \ub1 0.1 units, P < 0.01). In FHC (7 subjects) RAC remained unchanged after 6 months of lipid lowering treatment, but increased markedly (+55.2%, P < 0.05) when treatment was prolonged to 24 months. Lipid lowering treatment also reduced minimal FVR, the effect being significant bath after 6 and after 24 months. No changes in RAC and minimal FVR were seen after 6 months in controls. Thus, in subjects with a marked increase in serum cholesterol due to FHC, not only arteriolar dilatation, but also RAC and distensibility are markedly impaired. This impairment can be favourably affected by an effective lipid lowering treatment of long duration

A novel hyperekplexia-causing mutation in the pre-transmembrane segment 1 of the human glycine receptor alpha1 subunit reduces membrane expression and impairs gating by agonists

In this study, we have compared the functional consequences of three mutations (R218Q, V260M, and Q266H) in the 1 subunit of the glycine receptor (GlyRA1) causing hyperekplexia, an inherited neurological channelopathy. In HEK-293 cells, the agonist EC50s for glycine- activated Cl currents were increased from 26 M in wtGlyRA1, to 5747, 135, and 129 M in R218Q, V260M, and Q266H GlyRA1 channels, respectively. Cl currents elicited by -alanine and taurine, which behave as agonists at wtGlyRA1, were decreased in V260M and Q266H mutant receptors and virtually abolished in GlyRA1 R218Q receptors. Gly-gated Cl currents were similarly antagonized by low concentrations of strychnine in both wild-type (wt) and R218Q GlyRA1 channels, suggesting that the Arg-218 residue plays a crucial role in GlyRA1 channel gating, with only minor effects on the agonist/ antagonist binding site, a hypothesis supported by our molecular model of the GlyRA1 subunit. The R218Q mutation, but not the V260M or the Q266H mutation, caused a marked decrease of receptor subunit expression both in total cell lysates and in isolated plasma membrane proteins. This decreased expression does not seem to explain the reduced agonist sensitivity of GlyRA1 R218Q channels since no difference in the apparent sensitivity to glycine or taurine was observed when wtGlyRA1 receptors were expressed at levels comparable with those of R218Q mutant receptors. In conclusion, multiple mechanisms may explain the dramatic decrease in GlyR function caused by the R218Q mutation, possibly providing the molecular basis for its association with a more severe clinical phenotype

Using satellite estimates of aboveground biomass to assess carbon stocks in a mixed-management, semi-deciduous tropical forest in the Yucatan Peninsula

Information on the spatial distribution of forest aboveground biomass (AGB) and its uncertainty is important to evaluate management and conservation policies in tropical forests. However, the scarcity of field data and robust protocols to propagate uncertainty prevent a robust estimation through remote sensing. We upscaled AGB from field data to LiDAR, and to landscape scale using Sentinel-2 and ALOS-PALSAR through machine learning, propagated uncertainty using a Monte Carlo framework and explored the relative contributions of each sensor. Sentinel-2 outperformed ALOS-PALSAR (R2 = 0.66, vs 0.50), however, the combination provided the best fit (R2 = 0.70). The combined model explained 49% of the variation comparing against plots within the calibration area, and 17% outside, however, 94% of observations outside calibration area fell within the 95% confidence intervals. Finally, we partitioned the distribution of AGB in different management and conservation categories for evaluating the potential of different strategies for conserving carbon stock

Los recortes bibliográficos en los planes de estudio como representación de los diferentes enfoques del aprendizaje en el nivel inicial de Historia en la Facultad de Arquitectura de la Universidad de Bs.As. (1951-1971)

Sabemos que en el dictado de Historia de la Arquitectura en la FADU-UBA como materia de grado se presentan distintas problemáticas a estudiar de diferentes escalas. Fragmentos y totalidades (Molinos, 2012) son abordados desde diferentes voces que, no sólo llegan al alumno por su búsqueda e interés personal, sino que son proporcionadas, en su gran mayoría, por las cátedras como material de lectura. El abordaje a cada tema desde ese menú de voces sugeridas, comprende un universo más acotado y característico de la mirada –individual o colectiva- de los miembros de cada cátedra. Para explorar los diferentes enfoques propuestos por las cátedras a lo largo de la segunda mitad del s.XX en el aprendizaje de Historia de la Arquitectura, se consultaron los programas de estudio de la materia desde el año 1951 en adelante y se analizaron los recortes bibliográficos del nivel inicial. Las cátedras examinadas han desarrollado variaciones curriculares expresadas no sólo desde los contenidos, sino también desde la manera de abordar temas teóricos, lecturas críticas y el material ilustrado como herramientas de aprendizaje; reflejados todos en la selección y presentación de sus recortes bibliográficos a la comunidad académica.We already know that the subject known as “History of Architecture” at the FADU – UBA introduces relevant problems to be analyzed in depth and studied at different scales. Not only fragments but also wholes (Molinos, 2012) are covered and performed as from different voices that, are not only perceived by students due to its constant search and personal interest, but are also provided, in its great majority, by the class as reading material. The approach of each lesson from that menu of suggested voices, comprises a more limited and characterized universe of the individual- collective perspective of the members of each class. In order to explore the different approaches and points of views proposed by the classes throughout the second half of the XX century in the History of Architecture learning, programs of study were looked up as from the year 1951 up to date and initial level bibliography was analyzed in depth. Examined classes have developed curricular variations expressed not only as from the basis of the exposed contents, but also as from the manner in which theory, critic readings and illustrated material are used as learning tools, evidenced in the selection and presentation of their appropriate bibliographic cuts to the academic community.Eje3. La Enseñanza de la Historia y la Teoría: cuestiones curriculares.Facultad de Arquitectura y Urbanism

Los recortes bibliográficos en los planes de estudio como representación de los diferentes enfoques del aprendizaje en el nivel inicial de Historia en la Facultad de Arquitectura de la Universidad de Bs.As. (1951-1971)

Sabemos que en el dictado de Historia de la Arquitectura en la FADU-UBA como materia de grado se presentan distintas problemáticas a estudiar de diferentes escalas. Fragmentos y totalidades (Molinos, 2012) son abordados desde diferentes voces que, no sólo llegan al alumno por su búsqueda e interés personal, sino que son proporcionadas, en su gran mayoría, por las cátedras como material de lectura. El abordaje a cada tema desde ese menú de voces sugeridas, comprende un universo más acotado y característico de la mirada –individual o colectiva- de los miembros de cada cátedra. Para explorar los diferentes enfoques propuestos por las cátedras a lo largo de la segunda mitad del s.XX en el aprendizaje de Historia de la Arquitectura, se consultaron los programas de estudio de la materia desde el año 1951 en adelante y se analizaron los recortes bibliográficos del nivel inicial. Las cátedras examinadas han desarrollado variaciones curriculares expresadas no sólo desde los contenidos, sino también desde la manera de abordar temas teóricos, lecturas críticas y el material ilustrado como herramientas de aprendizaje; reflejados todos en la selección y presentación de sus recortes bibliográficos a la comunidad académica.We already know that the subject known as “History of Architecture” at the FADU – UBA introduces relevant problems to be analyzed in depth and studied at different scales. Not only fragments but also wholes (Molinos, 2012) are covered and performed as from different voices that, are not only perceived by students due to its constant search and personal interest, but are also provided, in its great majority, by the class as reading material. The approach of each lesson from that menu of suggested voices, comprises a more limited and characterized universe of the individual- collective perspective of the members of each class. In order to explore the different approaches and points of views proposed by the classes throughout the second half of the XX century in the History of Architecture learning, programs of study were looked up as from the year 1951 up to date and initial level bibliography was analyzed in depth. Examined classes have developed curricular variations expressed not only as from the basis of the exposed contents, but also as from the manner in which theory, critic readings and illustrated material are used as learning tools, evidenced in the selection and presentation of their appropriate bibliographic cuts to the academic community.Eje3. La Enseñanza de la Historia y la Teoría: cuestiones curriculares.Facultad de Arquitectura y Urbanism

Los recortes bibliográficos en los planes de estudio como representación de los diferentes enfoques del aprendizaje en el nivel inicial de Historia en la Facultad de Arquitectura de la Universidad de Bs.As. (1951-1971)

Sabemos que en el dictado de Historia de la Arquitectura en la FADU-UBA como materia de grado se presentan distintas problemáticas a estudiar de diferentes escalas. Fragmentos y totalidades (Molinos, 2012) son abordados desde diferentes voces que, no sólo llegan al alumno por su búsqueda e interés personal, sino que son proporcionadas, en su gran mayoría, por las cátedras como material de lectura. El abordaje a cada tema desde ese menú de voces sugeridas, comprende un universo más acotado y característico de la mirada –individual o colectiva- de los miembros de cada cátedra. Para explorar los diferentes enfoques propuestos por las cátedras a lo largo de la segunda mitad del s.XX en el aprendizaje de Historia de la Arquitectura, se consultaron los programas de estudio de la materia desde el año 1951 en adelante y se analizaron los recortes bibliográficos del nivel inicial. Las cátedras examinadas han desarrollado variaciones curriculares expresadas no sólo desde los contenidos, sino también desde la manera de abordar temas teóricos, lecturas críticas y el material ilustrado como herramientas de aprendizaje; reflejados todos en la selección y presentación de sus recortes bibliográficos a la comunidad académica.We already know that the subject known as “History of Architecture” at the FADU – UBA introduces relevant problems to be analyzed in depth and studied at different scales. Not only fragments but also wholes (Molinos, 2012) are covered and performed as from different voices that, are not only perceived by students due to its constant search and personal interest, but are also provided, in its great majority, by the class as reading material. The approach of each lesson from that menu of suggested voices, comprises a more limited and characterized universe of the individual- collective perspective of the members of each class. In order to explore the different approaches and points of views proposed by the classes throughout the second half of the XX century in the History of Architecture learning, programs of study were looked up as from the year 1951 up to date and initial level bibliography was analyzed in depth. Examined classes have developed curricular variations expressed not only as from the basis of the exposed contents, but also as from the manner in which theory, critic readings and illustrated material are used as learning tools, evidenced in the selection and presentation of their appropriate bibliographic cuts to the academic community.Eje3. La Enseñanza de la Historia y la Teoría: cuestiones curriculares.Facultad de Arquitectura y Urbanism

Isolating the effects of land use and functional variation on Yucatán's forest biomass under global change

Tropical forests hold large stocks of carbon in biomass and face pressures from changing climate and anthropogenic disturbance. Forests' capacity to store biomass under future conditions and accumulate biomass during regrowth after clearance are major knowledge gaps. Here we use chronosequence data, satellite observations and a C-cycle model to diagnose woody C dynamics in two dry forest ecotypes (semi-deciduous and semi-evergreen) in Yucatán, Mexico. Woody biomass differences between mature semi-deciduous (90 MgC ha−1) and semi-evergreen (175 MgC ha−1) forest landscapes are mostly explained by differences in climate (c. 60%), particularly temperature, humidity and soil moisture effects on production. Functional variation in foliar phenology, woody allocation, and wood turnover rate explained c. 40% of biomass differences between ecotypes. Modeling experiments explored varied forest clearance and regrowth cycles, under a range of climate and CO2 change scenarios to 2100. Production and steady state biomass in both ecotypes were reduced by forecast warming and drying (mean biomass 2021–2100 reduced 16–19% compared to 2001–2020), but compensated by fertilisation from rising CO2. Functional analysis indicates that trait adjustments amplify biomass losses by 70%. Experiments with disturbance and recovery across historically reported levels indicate reductions to mean forest biomass stocks over 2021–2100 similar in magnitude to climate impacts (10–19% reductions for disturbance with recovery). Forest disturbance without regrowth amplifies biomass loss by three- or four-fold. We conclude that vegetation functional differences across the Yucatán climate gradient have developed to limit climate risks. Climate change will therefore lead to functional adjustments for all forest types. These adjustments are likely to magnify biomass reductions caused directly by climate change over the coming century. However, the range of impacts of land use and land use change are as, or more, substantive than the totality of direct and indirect climate impacts. Thus the carbon storage of Yucatan's forests is highly vulnerable both to climate and land use and land use change. Our results here should be used to test and enhance land surface models use for dry forest carbon cycle assessment regionally and globally. A single plant functional type approach for modeling Yucatán's forests is not justified