Universidad Nacional del Centro de la Provincia de Buenos Aires

Mencionar el circuito Kula siempre fue para los
\n antropólogos una referencia natural y obligatoria a
\n Bronislaw Malinowski (1973 [1922]). Después de la
\n publicación de The Fame of Gawa. A symbolic study
\n of value transformation in a Massim (Papua New Guinea)
\n society esta referencia debe hacerse extensiva al
\n valioso y original aporte de Nancy Munn. La trascendencia
\n de este libro, publicado originalmente hace casi
\n dos décadas y aún no traducido al español, radica en
\n que concentra varias preocupaciones contemporáneas
\n de la antropología, sin duda poco discutidas en Argentina.
\n Desde una lectura fenomenológica de la teoría de
\n la práctica, The Fame of Gawa presenta una mirada
\n diferente de los modelos de intercambio del clásico
\n circuito Kula. Munn aborda aspectos tales como la
\n construcción sociocultural del espacio y el tiempo, los
\n problemas políticos y morales de la jerarquía y la igualdad,
\n y la descripción de procesos de creación de valor
\n en un espacio inter-islas. El análisis incorpora una
\n perspectiva de género que reconoce la influencia de
\n Annette Weiner (1976), quien renovó los estudios antropológicos
\n de la región Massim e introdujo esta perspectiva
\n a las discusiones sobre el kula. Mientras que
\n Malinowski realiza su análisis a partir de la/s institución/
\n es, Munn prefirió hacerlo partiendo del valor simbólico
\n de las prácticas sociales. El relato se destaca por
\n su coherencia interna. Así, su preocupación por la
\n totalidad se refleja tanto en el análisis de la producción
\n de valor en Gawa, como en la estrategia de construcción
\n y presentación del argumento. Párrafo extraído de la reseña a modo de resumen.

The exact timing, route, and process of the initial peopling of the Americas remains uncertain despite much research. Archaeological evidence indicates the presence of humans as far as southern Chile by 14.6 thousand years ago (ka), shortly after the Pleistocene ice sheets blocking access from eastern Beringia began to retreat. Genetic estimates of the timing and route of entry have been constrained by the lack of suitable calibration points and low genetic diversity of Native Americans. We sequenced 92 whole mitochondrial genomes from pre-Columbian South American skeletons dating from 8.6 to 0.5 ka, allowing a detailed, temporally calibrated reconstruction of the peopling of the Americas in a Bayesian coalescent analysis. The data suggest that a small population entered the Americas via a coastal route around 16.0 ka, following previous isolation in eastern Beringia for ~2.4 to 9 thousand years after separation from eastern Siberian populations. Following a rapid movement throughout the Americas, limited gene flow in South America resulted in a marked phylogeographic structure of populations, which persisted through time. All of the ancient mitochondrial lineages detected in this study were absent from modern data sets, suggesting a high extinction rate. To investigate this further, we applied a novel principal components multiple logistic regression test to Bayesian serial coalescent simulations. The analysis supported a scenario in which European colonization caused a substantial loss of pre-Columbian lineages.

We report genome-wide ancient DNA from 49 individuals forming four parallel time transects in Belize, Brazil, the Central Andes, and the Southern Cone, each dating to at least ∼9,000 years ago. The common ancestral population radiated rapidly from just one of the two early branches that contributed to Native Americans today. We document two previously unappreciated streams of gene flow between North and South America. One affected the Central Andes by ∼4,200 years ago, while the other explains an affinity between the oldest North American genome associated with the Clovis culture and the oldest Central and South Americans from Chile, Brazil, and Belize. However, this was not the primary source for later South Americans, as the other ancient individuals derive from lineages without specific affinity to the Clovis-associated genome, suggesting a population replacement that began at least 9,000 years ago and was followed by substantial population continuity in multiple regions.

In recent years, airborne and spaceborne hyperspectral imaging systems have advanced in terms of spectral and spatial resolution, which makes the data sets they produce a valuable source for land cover classification. The availability of hyperspectral data with fine spatial resolution has revolutionized hyperspectral image (HSI) classification techniques by taking advantage of both spectral and spatial information in a single classification framework.

BACKGROUND: Heart failure places a significant burden on patients and health systems in high-income countries. However, information about its burden in low- and middle-income countries (LMICs) is scant. We thus set out to review both published and unpublished information on the presentation, causes, management, and outcomes of heart failure in LMICs. METHODS AND FINDINGS: Medline, Embase, Global Health Database, and World Health Organization regional databases were searched for studies from LMICs published between 1 January 1995 and 30 March 2014. Additional unpublished data were requested from investigators and international heart failure experts. We identified 42 studies that provided relevant information on acute hospital care (25 LMICs; 232,550 patients) and 11 studies on the management of chronic heart failure in primary care or outpatient settings (14 LMICs; 5,358 patients). The mean age of patients studied ranged from 42 y in Cameroon and Ghana to 75 y in Argentina, and mean age in studies largely correlated with the human development index of the country in which they were conducted (r = 0.71, p<0.001). Overall, ischaemic heart disease was the main reported cause of heart failure in all regions except Africa and the Americas, where hypertension was predominant. Taking both those managed acutely in hospital and those in non-acute outpatient or community settings together, 57% (95% confidence interval [CI]: 49%-64%) of patients were treated with angiotensin-converting enzyme inhibitors, 34% (95% CI: 28%-41%) with beta-blockers, and 32% (95% CI: 25%-39%) with mineralocorticoid receptor antagonists. Mean inpatient stay was 10 d, ranging from 3 d in India to 23 d in China. Acute heart failure accounted for 2.2% (range: 0.3%-7.7%) of total hospital admissions, and mean in-hospital mortality was 8% (95% CI: 6%-10%). There was substantial variation between studies (p<0.001 across all variables), and most data were from urban tertiary referral centres. Only one population-based study assessing incidence and/or prevalence of heart failure was identified. CONCLUSIONS: The presentation, underlying causes, management, and outcomes of heart failure vary substantially across LMICs. On average, the use of evidence-based medications tends to be suboptimal. Better strategies for heart failure surveillance and management in LMICs are needed. Please see later in the article for the Editors' Summary.

Thermally activated clays, especially kaolinitic clays, are today revaluated as a source of supplementary cementitious materials to reduce the CO2 emissions and energy consumption originated in cement production. In this work, the influence of different thermal treatments on the pozzolanic activity of raw kaolin with 98% kaolinite and ordered structure was studied. Results show that pozzolanic activity of calcined kaolin decays when using a thermal treatment at high temperatures (800 ¡C) and high periods of residence (30 minutes). Furthermore, low calcination temperature (700 ¡C) must be corresponding with a residence time that guarantees a high dehydroxylation percentage. Sample treated during 10 minutes (94%DH) was less reactive than the one treated during 30 minutes (96%DH). Results contribute to the industry purposes to reduce the energy consumption, the CO2 emission and to contribute with new alternatives of sustainable development.

The persistence of the broad-spectrum antiparasitic activity of endectocide compounds relies on their disposition kinetics and pattern of plasma/tissues exchange in the host. This study evaluates the comparative plasma disposition kinetics of ivermectin (IVM), moxidectin (MXD) and doramectin (DRM) in cattle treated with commercially available injectable formulations. Twelve (12) parasite-free male Hereford calves (180-210 kg) grazing on pasture were allocated into three groups of four animals each. Animals in each group received either IVM (Ivomec 1%, MSD AGVET, Rahway, NJ, USA), MXD (Cydectin 1%. American Cyanamid, Wayne, NJ, USA) or DRM (Dectomax 1%, Pfizer Inc., New York, NY, USA) by subcutaneous injection at a dose of 200 micrograms/kg. Jugular blood samples were collected from 1 h up to 80 days post-treatment, and plasma extracted, derivatized and analysed by high performance liquid chromatography (HPLC) using fluorescence detection. The parent molecules were detected in plasma between 1 h and either 70 (DRM) or 80 (IVM and MXD) days post-treatment. The absorption of MXD from the site of injection was significantly faster (absorption half-life (t1/2ab) = 1.32 h) than those of IVM (t1/2ab = 39.2 h) and DRM (t1/2ab = 56.4 h). MXD peak plasma concentration (Cmax) was reached significantly earlier (8.00 h) compared to those of IVM and DRM (4-6 days post-treatment). There were no differences on Cmax values: the area under the concentration-time curve (AUC) was higher for IVM (459 ng.d/mL) and DRM (627 ng.d/mL) compared to that of MXD (217 ng.d/mL). The mean plasma residence time was longer for MXD (14.6 d) compared to IVM (7.35 d) and DRM (9.09 d). Unidentified metabolites were detected in plasma: they accounted for 5.75% (DRM), 8.50% (IVM) and 13.8% (MXD) of the total amount of their respective parent drugs recovered in plasma. The comparative plasma disposition kinetics of IVM, MXD and DRM in cattle, characterized over 80 days post-treatment under standardized experimental conditions, is reported for the first time.

Extracellular matrix (ECM) structures within skeletal muscle play an important, but under-appreciated, role in muscle development, function and adaptation. Each individual muscle is surrounded by epimysial connective tissue and within the muscle there are two distinct extracellular matrix (ECM) structures, the perimysium and endomysium. Together, these three ECM structures make up the intramuscular connective tissue (IMCT). There are large variations in the amount and composition of IMCT between functionally different muscles. Although IMCT acts as a scaffold for muscle fiber development and growth and acts as a carrier for blood vessels and nerves to the muscle cells, the variability in IMCT between different muscles points to a role in the variations in active and passive mechanical properties of muscles. Some traditional measures of the contribution of endomysial IMCT to passive muscle elasticity relied upon tensile measurements on single fiber preparations. These types of measurements may now be thought to be missing the important point that endomysial IMCT networks within a muscle fascicle coordinate forces and displacements between adjacent muscle cells by shear and that active contractile forces can be transmitted by this route (myofascial force transmission). The amount and geometry of the perimysial ECM network separating muscle fascicles varies more between different muscle than does the amount of endomysium. While there is some evidence for myofascial force transmission between fascicles via the perimysium, the variations in this ECM network appears to be linked to the amount of shear displacements between fascicles that must necessarily occur when the whole muscle contracts and changes shape. Fast growth of muscle by fiber hypertrophy is not always associated with a high turnover of ECM components, but slower rates of growth and muscle wasting may be associated with IMCT remodeling. A hypothesis arising from this observation is that the level of cell signaling via shear between integrin and dystroglycan linkages on the surface of the muscle cells and the overlying endomysium may be the controlling factor for IMCT turnover, although this idea is yet to be tested.

The Convention on Biological Diversity's 2020 targets are an improvement over the 2010 target, but they could be strengthened.

Meat color is important for consumer acceptability, with excessively dark meat often associated with consumer rejection. It is determined chromatically by pigment content (measured by hue and chroma) and achromatically by scattering of light by the microstructure (measured by lightness), the latter of which has received minimal research focus. This review discusses the individual components of the meat microstructure that cause differences in achromatic contributions to color. Differences in achromatic light scattering between light and dark extremes of meat color are most likely explained by structural attributes within the muscle cell. These differences are proposed to arise from variations in (a) transverse shrinkage of the structural lattice of the myofilaments, myofibrils, and muscles fibers, (b) longitudinal shrinkage of the sarcomere, and (c) different protein composition of the surrounding medium (sarcoplasm and extracellular space). These are discussed at a mechanistic level, in relation to six parameters of the muscle cell: (a) protein surface charge altering the myofilament spacing, (b) protein solubility, (c) sarcoplasmic protein binding to myofilaments and myofibrils, (d) integrity of the cytoskeleton and cell adhesion proteins, (e) sarcomere integrity and myofibrillar proteins, and (f) myosin denaturation and rigor bond modification. New data are presented to support the proposed role of structural elements in muscle causing achromatic light scattering and their contribution to the surface color of meat. In addition, the relationships between lightness and water holding capacity and pH are explored and the economic impact of dark meat for the meat industry is discussed.

There are many unanswered questions about the population history of the Central and South Central Andes, particularly regarding the impact of large-scale societies, such as the Moche, Wari, Tiwanaku, and Inca. We assembled genome-wide data on 89 individuals dating from ∼9,000-500 years ago (BP), with a particular focus on the period of the rise and fall of state societies. Today's genetic structure began to develop by 5,800 BP, followed by bi-directional gene flow between the North and South Highlands, and between the Highlands and Coast. We detect minimal admixture among neighboring groups between ∼2,000-500 BP, although we do detect cosmopolitanism (people of diverse ancestries living side-by-side) in the heartlands of the Tiwanaku and Inca polities. We also highlight cases of long-range mobility connecting the Andes to Argentina and the Northwest Andes to the Amazon Basin. VIDEO ABSTRACT.

Software visualization studies techniques and methods for graphically representing different aspects of software. Its main goal is to enhance, simplify and clarify the mental representation a software engineer has of a computer system. During many years, visualization in 2D space has been actively studied, but in the last decade, researchers have begun to explore new 3D representations for visualizing software. In this article, we present an overview of current research in the area, describing several major aspects like: visual representations, interaction issues, evaluation methods and development tools. We also perform a survey of some representative tools to support different tasks, i.e., software maintenance and comprehension, requirements validation and algorithm animation for educational purposes, among others. Finally, we conclude identifying future research directions.

&mdash; The effects of daily herbage allowance (DHA = herbage mass [HM] x daily offered area [DOA]) and cow characteristics upon herbage intake at grazing were assessed in two experiments. In n experiment 1, two DHA (low and medium, 19 and 26 kg organic matter [OM]/cow/day) were com- pared in a continuous design using two groups of five cows. In experiment 2, three DHA (low, medium and high, 19, 29 and 46 kg OM/cow/day) were compared in a 3 x 3 latin square design using three groups of five cows. Mid-lactating cows (six first lactation per trial) were used. Fat-corrected milk at turnout (FCMt) ranged between 17 to 35 kg and live weight (LW) from 510 to 680 kg. Cows strip-grazed plots of vegetative Lolium perenne and did not receive concentrates. Herbage mass cut to ground level (HM) ranged from 3.5 to 7.1 t OM/ha. In experiment 1, herbage organic matter intake (HOMI) (13.5 vs 14.9 kg/day) and FCM yield (20.6 vs 22.0 kg/day) tended to increase from low to medium DHA but dif- ferences were not significant. In experiment 2, HOMI increased in a quadratic manner (13.8, 16.2 and 16.7 kg/day) and FCM increased linearly (P < 0.01 ) with DHA (20.4, 21 .7 and 23.0 kg/day for low, medium and high DHA, respectively). In both experiments, HOMI was consistently lower in first lac- tation compared to adult cows and large between-cow variations within lactation were noted. From the pooled data, HOMI was related to DHA and cow characteristics: HOMI = 7.9 -98 DHA-1 + 0.264 FCMt + 0.0073 LW (n = 95, R 2 = 0.60, rsd = 1.77 kg). However, splitting DHA into its two components accounted for more of the variance in HOMI: HOMI =-20.4 -115 DOA-1 + 9.63 HM -0.873 HM 2 + 0.266 FCMt + 0.0095 LW (R 2 = 0.70, rsd = 1.56 kg). These relationships showed that HOMI was affected by DHA but the original sward herbage mass/structure does have an independant effect in regulating intake. Moreover, voluntary intake increases with the potential of milk yield and this increase could account for the two-thirds of the supplementary energy requirements. dairy cows / grazing / intake / herbage allowance / animal requirements Rsum &mdash; Effet des quantits d'herbe offertes, de la biomasse et des caractristiques ani- males sur l'ingestion des vaches laitires au pturage. L'effet de la quantit d'herbe alloue (DHA = biomasse (HM) x surface offerte journellement (DOA)) et des caractristiques des animaux sur les quantits de MO d'herbe ingres au pturage (HOMI) ont t analyses au cours de deux essais. Dans l'essai 1, deux niveaux de DHA (Bas et Moyen, 19 et 26 kg MO/vache/jour) ont t compars dans un schma en continu en utilisant deux groupes de cinq vaches apparies. Dans le second essai, trois niveaux d'herbe alloue (Bas, Moyen et Haut ; 19, 29 et 46 kgljour) ont t compars dans un schma en carr latin 3 x 3 en utilisant trois lots de cinq vaches. Tous les animaux taient en milieu de lactation et six primipares ont t utilises par essai. la mise l'herbe, la production de lait 4 % (FCMt) et le poids vif (LtN) variaient de 17 35 kgljour et de 510 680 kg. Les vaches n'ont pas reu de concentr et ont t conduites en pturage rationn sur prairies de ray-grass anglais pendant toute la dure des essais. La biomasse coupe au niveau du sol a vari de 3,5 7,1 t MOlha entre les priodes. Dans l'essai 1, HOMI (13,5 versus 14,9 kglj) et la production de la 4 % (20,6 versus 22,0 kgljour) ont eu tendance augmenter entre le traitement Bas et Moyen mais les diffrences n'ont pas t significatives. Dans l'essai 2, HOMI a augment de manire curvilinaire (13,8 ; 16,2 ; 16,7 kgljour) et la production de lait 4 % a augment linairement avec le niveau d'herbe alloue (20,4; 21,7 et 23,0 kgljour). HOMI a toujours t beaucoup plus faible pour les vaches primipares que les vaches adultes et des diffrences interindividuelles importantes sont apparues pour un mme rang de lactation. partir de l'ensemble des donnes individuelles nous avons montr que HOMI peut tre prdite partir de DHA et des caractristiques des animaux : HOMI = 7,9 -98 DHA-1 + 0,264 FCMt+ 0,0073 LVV (n = 95, R 2 = 0,6 0 , etr= 1,77kg). Cependant, la prcision de ce modle est sensiblement amliore lorsque l'on considre sparment les deux composantes de DHA : HOMI = -20,4 -115 DOA-I + 9,63 HM -0,873 HM 2 + 0,266 FCMt + 0, 0095 LW(R2 = 0, 70, etr = 1,56 kg). Ces relations montrent que HOMI est affecte par DHA mais aussi que la biomasse et/ou la structure ini- tiale de la prairie affecte galement les quantits ingres. De plus les quantits ingres augmentent avec le potentiel de production des animaux et cet accroissement couvre environ les deux tiers des besoins supplmentaires de production pour des pturages de bonne qualit.

Self-similar plane solutions for the inertial stage of gravity currents are related to the initial parameters and a coefficient that is determined by the boundary condition at the front. Different relations have been proposed for the boundary condition in terms of a Froude number at the front, none of which have a sound theoretical or experimental basis. This paper focuses on considerations of the appropriate Froude number based on results of lock-exchange experiments in which extended inertial gravity currents are generated in a rectangular cross-section channel. We use ‘top-hat’ vertical density profiles of the currents to obtain an ‘equivalent’ depth, defined by profiles having the same buoyancy at every position as the real profiles. As in previous work, our experimental results show that in the initial constant-velocity phase the Froude number can be defined in terms of the lock depth. However, as the current enters the similarity phase when the initial release conditions are no longer relevant, we find that the Froude number is more appropriately defined in terms of the maximum height of the head. Strictly speaking, the self-similar solution to the shallow-water equations requires a front condition that uses the height at the rear of the head. We find that this rear Froude number is not constant and is a function of the head Reynolds number over the range 400–4500.

Chapter 5 analyzes the anthropogenic greenhouse gas (GHG) emission trends until the present and the main drivers that explain those trends. The chapter uses different perspectives to analyze past GHG-emissions trends, including aggregate emissions flows and per capita emissions, cumulative emissions, sectoral emissions, and territory-based vs. consumption-based emissions. In all cases, global and regional trends are analyzed. Where appropriate, the emission trends are contextualized with long-term historic developments in GHG emissions extending back to 1750.

A nanoscale, synthetic perturbation was all that was required to nudge a natural, self-assembly process toward significantly higher order. Metallic thin film strips were transformed into nanoparticle arrays by nanosecond, liquid-phase dewetting. Arrays formed according to an evolving Rayleigh-Plateau instability, yet nanoparticle diameter and pitch were poorly controlled. However, by patterning a nanoscale sinusoid onto the original strip edge, a precise nanoparticle diameter and pitch emerged superseding the naturally evolving Rayleigh-Plateau instability.

Available vaccines against Brucella spp. are live attenuated Brucella strains. In order to engineer a better vaccine to be used in animals and humans, our laboratory aims to develop an innocuous subunit vaccine. Particularly, we are interested in the outer membrane proteins (OMPs) of B. abortus: Omp16 and Omp19. In this study, we assessed the use of these proteins as vaccines against Brucella in BALB/c mice. Immunization with lipidated Omp16 (L-Omp16) or L-Omp19 in incomplete Freund's adjuvant (IFA) conferred significant protection against B. abortus infection. Vaccination with unlipidated Omp16 (U-Omp16) or U-Omp19 in IFA induced a higher degree of protection than the respective lipidated versions. Moreover, the level of protection induced after U-Omp16 or U-Omp19 immunization in IFA was similar to that elicited by live B. abortus S19 immunization. Flow cytometric analysis showed that immunization with U-Omp16 or U-Omp19 induced antigen-specific CD4(+) as well as CD8(+) T cells producing gamma interferon. In vivo depletion of CD4(+) or CD8(+) T cells in mice immunized with U-Omp16 or U-Omp19 plus IFA resulted in a loss of the elicited protection, indicating that both cell types are mediating immune protection. U-Omp16 or U-Omp19 vaccination induced a T helper 1 response, systemic protection in aluminum hydroxide formulation, and oral protection with cholera toxin adjuvant against B. abortus infection. Both immunization routes exhibited a similar degree of protection to attenuated Brucella vaccines (S19 and RB51, respectively). Overall these results indicate that U-Omp16 or U-Omp19 would be a useful candidate for a subunit vaccine against human and animal brucellosis.

Hydration products of Portland cement pastes, hydrated in water and in the presence of zinc ions were studied comparatively at different ages. Hydration products were studied by X ray diffractions (XRD) and infrared spectroscopy (IR). Although IR is not frequently used in cement chemistry, it evidenced a new phase Ca(Zn(OH)3)2. 2H2O formed during cement hydration in the presence of zinc. The significant retardation of early cement hydration in the presence of zinc is assessed in detail by differential calorimetry as a complement to the study carried out by IR and XRD, providing evidence that permits to evaluate the kinetic of the early hydration.

Abstract People have unique ways of learning, which may greatly affect the learning process and, therefore, its outcome. In order to be effective, e‐learning systems should be capable of adapting the content of courses to the individual characteristics of students. In this regard, some educational systems have proposed the use of questionnaires for determining a student learning style; and then adapting their behaviour according to the students' styles. However, the use of questionnaires is shown to be not only a time‐consuming investment but also an unreliable method for acquiring learning style characterisations. In this paper, we present an approach to recognize automatically the learning styles of individual students according to the actions that he or she has performed in an e‐learning environment. This recognition technique is based upon feed‐forward neural networks.

In medical practice the reference values of arterial stiffness came from multicenter registries obtained in Asia, USA, Australia and Europe. Pulse wave velocity (PWV) is the gold standard method for arterial stiffness quantification; however, in South America, there are few population-based studies. In this research PWV was measured in healthy asymptomatic and normotensive subjects without history of hypertension in first-degree relatives. Normal PWV and the 95% confidence intervals values were obtained in 780 subjects (39.8 ± 18.5 years) divided into 7 age groups (10-98 years). The mean PWV found was 6.84 m/s ± 1.65. PWV increases linearly with aging with a high degree of correlation (r (2) = 0.61; P < 0.05) with low dispersion in younger subjects. PWV progressively increases 6-8% with each decade of life; this tendency is more pronounced after 50 years. A significant increase of PWV over 50 years was demonstrated. This is the first population-based study from urban and rural people of Argentina that provides normal values of the PWV in healthy, normotensive subjects without family history of hypertension. Moreover, the age dependence of PWV values was confirmed.