Intraspecific Aggregation Alters Competitive Interactions in Experimental Plant Communities

We tested the prediction from spatial competition models that intraspecific aggregation may promote coexistence and thus maintain biodiversity with experimental communities of four annual species. Monocultures, three-species mixtures, and the four-species mixture were sown at two densities and with either random or intraspecifically aggregated distributions. There was a hierarchy of competitive abilities among the four species. The weaker competitors showed higher aboveground biomass in the aggregated distribution compared to the random distribution, especially at high density. In one species, intraspecific aggregation resulted in an 86% increase in the number of flowering individuals and a 171% increase in the reproductive biomass at high density. The competitively superior species had a lower biomass in the aggregated distribution than in the random distribution at high density. The data support the hypothesis that the spatial distribution of plants profoundly affects competition in such a way that weaker competitors increase their fitness while stronger competitors are suppressed when grown in the neighborhood of conspecifics. This implies that the spatial arrangement of plants in a community can be an important determinant of species coexistence and biodiversity.

Peptide-based interactions with calnexin target misassembled membrane proteins into endoplasmic reticulum-derived multilamellar bodies.

Oligomeric assembly of neurotransmitter transporters is a prerequisite for their export from the endoplasmic reticulum (ER) and their subsequent delivery to the neuronal synapse. We previously identified mutations, e.g., in the gamma-aminobutyric acid (GABA) transporter-1 (GAT1), which disrupted assembly and caused retention of the transporter in the ER. Using one representative mutant, GAT1-E101D, we showed here that ER retention was due to association of the transporter with the ER chaperone calnexin: interaction with calnexin led to accumulation of GAT1 in concentric bodies corresponding to previously described multilamellar ER-derived structures. The transmembrane domain of calnexin was necessary and sufficient to direct the protein into these concentric bodies. Both yellow fluorescent protein-tagged versions of wild-type GAT1 and of the GAT1-E101D mutant remained in disperse (i.e., non-aggregated) form in these concentric bodies, because fluorescence recovered rapidly (t(1/2) approximately 500 ms) upon photobleaching. Fluorescence energy resonance transfer microscopy was employed to visualize a tight interaction of GAT1-E101D with calnexin. Recognition by calnexin occurred largely in a glycan-independent manner and, at least in part, at the level of the transmembrane domain. Our findings are consistent with a model in which the transmembrane segment of calnexin participates in chaperoning the inter- and intramolecular arrangement of hydrophobic segment in oligomeric proteins.

Supramolecular Polymers in DNA Nanotechnology

Creation of biocompatible functional materials is an important task in supramolecular chemistry. In this contribution, we report on noncovalent synthesis of DNA-grafted supramolecular polymers (SPs). DNA-grafted SPs enable programmed arrangement of oligonucleotides in a regular, tightly packed one-dimensional array. Further interactions of DNA-grafted SPs with complementary DNA strands leads to the formation of networks through highly cooperative G-C blunt-end stacking interactions. The structural changes in the polymeric core enable to monitor spectroscopically the stepwise formation of networks. Such stimuli-responsive supramolecular networks may lead to the development of DNA-based smart materials.

Recognizing a Single-Issue Spatial Election

A single-issue spatial election is a voter preference profile derived from an arrangement of candidates and voters on a line, with each voter preferring the nearer of each pair of candidates. We provide a polynomial-time algorithm that determines whether a given preference profile is a single-issue spatial election and, if so, constructs such an election. This result also has preference representation and mechanism design applications.

HEMATOCRIT AND HEMOGLOBIN, ATP AND DPG CONCENTRATIONS IN ANDEAN MAN: VARIABILITY BY SEX, AGE, VILLAGE, ALTITUDE, WEIGHT, SMOKING HABITS AND GENETIC CONSTITUTION

The Departmento de Arica in northern Chile was chosen as the investigation site for a study of the role of certain hematologic and glycolytic variables in the physiological and genetic adaptation to hypoxia.^ The population studied comprised 876 individuals, residents of seven villages at three altitudes: coast (0-500m), sierra (2,500-3,500m) and altiplano (> 4,000m). There was an equal number of males and females ranging in ages from six to 90 years. Although predominantly Aymara, those of mixed or Spanish origin were also examined. The specimens were collected in heparinized vacutainers precipitated with cold trichloroacetic acid (TCA) and immediately frozen to -196(DEGREES)C. Six variables were measured. Three were hematologic: hemoglobin, hematocrit and mean cell hemoglobin concentration. The three others were glycolytic: erythrocyte 2,3-diphosphoglycerate (DPG), adenosine triphosphate (ATP) and the percentage of phosphates (DPG + ATP) in the form of DPG.^ Hemoglobin and hematocrit were measured on site. The DPG and ATP content was assayed in specimens which had been frozen at -196(DEGREES)C and transported to Houston. Structured interviews on site provided information as to lifestyle and family pedigrees.^ The following results were obtained: (1) The actual village, rather than the altitude, of examination accounted for the greatest proportion of the variance in all variables. In the coast, a large difference in levels of ionic lithium in the drinking water exists. The chemical environment of food and drink is postulated to account, in part, for the importance of geographic location in explaining the observed variance. (2) Measurements of individuals from the two extreme altitudes, coast and altiplano, did not exhibit the same relationship with age and body mass. The hematologic variables were significantly related to both age and body build in the coast. The glycolytic variables were significantly related to age and body mass in the altiplano. (3) The environment modified male values more than female values in all variables. The two sexes responded quite differently to age and changes in body mass as well. The question of differing adaptability of the two sexes is discussed. (4) Environmental factors explained a significantly higher proportion of total variability in the altiplano than in the coast for hemoglobin, hematocrit and DPG. Most of the ATP variability at both altitudes is explained by genetic factors. ^

DISCHARGE PLANNING: A PROCESS MODEL

As the requirements for health care hospitalization have become more demanding, so has the discharge planning process become a more important part of the health services system. A thorough understanding of hospital discharge planning can, then, contribute to our understanding of the health services system. This study involved the development of a process model of discharge planning from hospitals. Model building involved the identification of factors used by discharge planners to develop aftercare plans, and the specification of the roles of these factors in the development of the discharge plan. The factors in the model were concatenated in 16 discrete decision sequences, each of which produced an aftercare plan.^ The sample for this study comprised 407 inpatients admitted to the M. D. Anderson Hospital and Tumor Institution at Houston, Texas, who were discharged to any site within Texas during a 15 day period. Allogeneic bone marrow donors were excluded from the sample. The factors considered in the development of discharge plans were recorded by discharge planners and were used to develop the model. Data analysis consisted of sorting the discharge plans using the plan development factors until for some combination and sequence of factors all patients were discharged to a single site. The arrangement of factors that led to that aftercare plan became a decision sequence in the model.^ The model constructs the same discharge plans as those developed by hospital staff for every patient in the study. Tests of the validity of the model should be extended to other patients at the MDAH, to other cancer hospitals, and to other inpatient services. Revisions of the model based on these tests should be of value in the management of discharge planning services and in the design and development of comprehensive community health services.^

Facies investigations on sediment core CRP-3 from the Ross Sea, Antarctica

The Cenozoic Victoria Land Basin (VLB) stratigraphic section penetrated by CRP-3 is mostly of Early Oligocene age. It contains an array of lithofacies comprising fine-grained mudrocks, interlaminated and interbedded mudrocks/sandstones, mud-rich and mud-poor sandstones, conglomerates and diamctites that are together interpreted as the products of shallow marine to possibly non-marine environments of deposition, affected by the periodic advance and retreat of tidewater glaciers. This lithofacies assemblage can be readily rationalised using the facies scheme designed originally for CRP-2/2A, and published previously. The uppermost 330 metres below sea floor (mbsf) shows a cyclical arrangement of lithofacies also similar to that recognised throughout CRP-2/2A, and interpreted to reflect cyclical variations in relative sea-level driven by ice volume fluctuations ('Motif A'). Between 330 and 480 mbsf, a series of less clearly cyclical units, generally fining-upward but nonetheless incorporating a significant subset of the facies assemblage, has been identified and noted in the Initial Report as 'Motif B' Below 480 mbsf, the section is arranged into a repetitive succession of fining-upward units, each of which comprises dolerite clast conglomerate at the base passing upward into relatively thick intervals of sandstones. The cycles present down 480 mbsf are defined as sequences, each interpreted to record cyclical variation of relative sea-level. The thickness distribution of sequences in CRP-3 provides some insights into the geological variables controlling sediment accumulation in the Early Oligocene section. The uppermost part of the section in CRP-3 comprises two or three thick, complete sequences that show a broadly symmetrical arrangement of lithofacies (similar to Sequences 9-11 in CRP-2/2A). This suggests a period of relatively rapid tectonic subsidence, which allowed preservation of the complete facies cycle. Below Sequence 3, however, is a considerable interval of thin, incomplete and erosionally truncated sequences (4-23), which incorporates both the remainder of Motif A sequences and all Motif B sequences recognised. The thinner and more truncated sequences suggest sediment accumulation under conditions of reduced accommodation, and given the lack of evidence for glacial conditions (see Powell et al., this volume) tends to argue for a period of reduced tectonic subsidence. The section below 480 mbsf consists of a series of fining-upward, conglomerate to sandstone intervals which cannot be readily interpreted in terms of relative sea-level change. A relatively mudrock-rich interval above the basal conglomerate/breccia (782-762 mbsf) may record initial flooding of the basin during early rift subsidence. The lithostratigraphy summarised above has been linked to seismic reflection data using depth conversion techniques (Henrys et al., this volume). The three uppermost reflectors ('o', 'p' and 'q') correlate to the package of thick sequences 1-3, and several deeper reflectors can also be correlated to sequence boundaries. The package of thick Sequences 1-3 shows a sheet-like cross-sectional geometry on seismic reflection lines, unlike the similar package recognised in CRP-2/2A.

La configuración de la Sociología como contenidos y/o espacio curricular

Este artículo tiene el propósito de compartir algunos hallazgos sobre la configuración de las disciplinas de las carreras como espacio o contenido escolar en el sistema educativo de la Provincia de Mendoza, en particular, las modelizaciones pedagógicas de las prácticas de residencia de la cohorte 2006 del profesorado de Sociología. Así, la unidad de indagación fueron nueve Portafolios y sus Memorias en los que se documentaron y narraron dieciocho experiencias de prácticas de residencias desarrolladas durante el ciclo lectivo 2006. Este aporte está organizado en cuatro apartados. En el primero, se describen los dispositivos de trabajo de la cátedra en torno a la organización de las experiencias de residencias de los estudiantes del profesorado (2004-2013). En el segundo, se caracterizan los rasgos de los Portafolios y Memorias de prácticas y cursantes de la cohorte 2006 del Profesorado de Sociología. En el tercer apartado, se ensaya una caracterización de las modelizaciones pedagógicas emergentes, y se presta especial atención a la descripción de sus rasgos. Finalmente, en el cuarto, se proponen una serie de reflexiones en torno a los hallazgos obtenidos y a algunas líneas de indagación emergentes.

La evolución reciente de las políticas de paisaje en España y el convenio europeo del paisaje

En este artículo se analiza el desarrollo de las políticas paisajísticas en España, especialmente en su etapa actual, cuando el paisaje se ha convertido en un instrumento importante para la diagnosis y el desarrollo del territorio. En primer lugar, se estudian las diferentes etapas en la evolución de las políticas del paisaje en España, desde el periodo donde el paisaje sólo tenía un significado artístico y cultural (principios del siglo XX) hasta la firma y ratificación por España del Convenio Europeo del Paisaje (CEP) que establece un marco común para las políticas paisajísticas europeas. Se realiza un análisis crítico de los planteamientos del CEP y de los problemas de su implementación en España. Se hace hincapié en la problemática de la democracia y participación pública en la toma de decisiones políticas en materia de ordenación del territorio y paisaje que recomienda el CEP y las dificultades para llevar a cabo las medidas que allí se proponen. Como conclusión, se realiza una reflexión sobre la integración del paisaje en las políticas de ordenación del territorio europeas como una manifestación de la emergencia de las formas más democráticas de gestión del territorio y sobre los nuevos retos de las investigaciones paisajísticas.

O subtexto do Chanceler Pero Lopez de Ayala na Crônica de D. João I de Fernão Lopes referente ao biênio de 1383-1384 : autoridade e desafio

El intento del artículo es percibir cómo el cronista portugués Fernão Lopes (1385-1460) se apropia, en el último texto suyo, del discurso del castellano Pero Lopez de Ayala (1332-1407) en la Crónica de D. Juan I. La parte elegida para el examen fue el bienio de 1383-1384, antes, por lo tanto, de la Batalla de Aljubarrota (1385). La comparación de las crónicas citadas todavía ya fue realizada por investigadores renombrados, sin embargo mi trabajo sigue el camino por la reducción de escala, o sea, por un análisis interpretativo de un bienio especifico, con la finalidad de iniciar un análisis más abarcador del rasgo de la crónica medieval ibérica medieval, objeto de mi presente pesquisa.

El uso del caso en el dispositivo de formación en la cátedra de Institución Educativa

Con la apertura del Ciclo de Profesorado destinado a los licenciados en Sociología, Ciencia Política y Administración Pública, Trabajo Social y Comunicación Social en 2003, se abre la cátedra de Institución Educativa. Uno de los rasgos de la configuración de la propuesta fue la construcción y uso de un caso. A nueve años y seis cohortes de egresados nos preguntamos ¿qué rasgos tiene el dispositivo de formación de la cátedra Institución Educativa? y ¿cómo se ha configurado el caso en el dispositivo de formación propuesto por dicha cátedra?

Turbulent flux and meteorological measurements during ARCTEX-2006 campaign

This dataset present result from the DFG- funded Arctic-Turbulence-Experiment (ARCTEX-2006) performed by the University of Bayreuth on the island of Svalbard, Norway, during the winter/spring transition 2006. From May 5 to May 19, 2006 turbulent flux and meteorological measurements were performed on the monitoring field near Ny-Ålesund, at 78°55'24'' N, 11°55'15'' E Kongsfjord, Svalbard (Spitsbergen), Norway. The ARCTEX-2006 campaign site was located about 200 m southeast of the settlement on flat snow covered tundra, 11 m to 14 m above sea level. The permanent sites used for this study consisted of the 10 m meteorological tower of the Alfred Wegener Institute for Polar- and Marine Research (AWI), the international standardized radiation measurement site of the Baseline Surface Radiation Network (BSRN), the radiosonde launch site and the AWI tethered balloon launch sites. The temporary sites - set up by the University of Bayreuth - were a 6 m meteorological gradient tower, an eddy-flux measurement complex (EF), and a laser-scintillometer section (SLS). A quality assessment and data correction was applied to detect and eliminate specific measurement errors common at a high arctic landscape. In addition, the quality checked sensible heat flux measurements are compared with bulk aerodynamic formulas that are widely used in atmosphere-ocean/land-ice models for polar regions as described in Ebert and Curry (1993, doi:10.1029/93JC00656) and Launiainen and Cheng (1995). These parameterization approaches easily allow estimation of the turbulent surface fluxes from routine meteorological measurements. The data show: - the role of the intermittency of the turbulent atmospheric fluctuation of momentum and scalars, - the existence of a disturbed vertical temperature profile (sharp inversion layer) close to the surface, - the relevance of possible free convection events for the snow or ice melt in the Arctic spring at Svalbard, and - the relevance of meso-scale atmospheric circulation pattern and air-mass advection for the near-surface turbulent heat exchange in the Arctic spring at Svalbard. Recommendations and improvements regarding the interpretation of eddy-flux and laser-scintillometer data as well as the arrangement of the instrumentation under polar distinct exchange conditions and (extreme) weather situations could be derived.

El ordenamiento del sistema jurídico ateniense a partir del vocabulario de la legalidad en Antígona de Sófocles

Abordamos en Antígona la voz nómos utilizada por la protagonista en su último discurso (vv. 908 y 914). Con ese término califica la razón de su proceder, que justifica contraponiendo su condición como hermana del muerto a una potencial situación como esposa o madre de un difunto. Pese al uso de nómos, observa Etxabe (2009: 61), tales palabras no han sido articuladas con un argumento legal; no obstante, a un estudio con tales propósitos pareciera poder objetarse el hecho de que el léxico jurídico implica ante todo generalidad, lo que entraría en contradicción con la particularidad y excepcionalidad que caracteriza aquello que Antígona califica como nómos. Revisamos entonces qué implica para Antígona el entierro de su hermano y luego abordamos el asunto desde los estudios más recientes sobre la legalidad griega, atendiendo especialmente al ordenamiento del sistema jurídico que tiene lugar en el siglo V a.C., y que implica un cambio de actitud con respecto a las leyes no escritas frecuentemente asociadas a Antígona

Y te llevaste en andas al ángel de los perdedores : El nómos de Antígona en su discurso final a partir del vocabulario legal en Antígona de Sófocles

Abordamos en Antígona la voz nómos utilizada por la protagonista en los vv. 908 y 914 de su último discurso. Con ese término califica la razón de su proceder, según la cual nunca habría realizado un entierro por un hijo o un esposo muerto pues la gente sensata justificaría sólo la sepultura de su hermano ya que un esposo y un hijo podría volver a tener pero nunca un hermano, con su padre y madre muertos. Pese a su uso, observa Etxabe (2009: 61), tales palabras no han sido articuladas con un argumento legal. No obstante, a un estudio con tales propósitos pareciera poder objetarse el hecho de que el léxico jurídico implica ante todo generalidad, lo que entraría en contradicción con la particularidad y excepcionalidad que caracteriza aquello que Antígona califica como nómos. Revisamos entonces qué implica para Antígona el entierro de su hermano y luego abordamos el asunto desde los estudios más recientes sobre la legalidad griega. En un contexto histórico en el cual tiene lugar un ordenamiento del sistema jurídico, que implica un cambio de actitud con respecto a las leyes no escritas frecuentemente asociadas a Antígona, la expresión nómos de este pasaje requiere la integración del trabajo filológico y los estudios del derecho griego, de la familia y de las relaciones de género en la Atenas del siglo V a.C.

Y te llevaste en andas al ángel de los perdedores : El nómos de Antígona en su discurso final a partir del vocabulario legal en Antígona de Sófocles

Abordamos en Antígona la voz nómos utilizada por la protagonista en los vv. 908 y 914 de su último discurso. Con ese término califica la razón de su proceder, según la cual nunca habría realizado un entierro por un hijo o un esposo muerto pues la gente sensata justificaría sólo la sepultura de su hermano ya que un esposo y un hijo podría volver a tener pero nunca un hermano, con su padre y madre muertos. Pese a su uso, observa Etxabe (2009: 61), tales palabras no han sido articuladas con un argumento legal. No obstante, a un estudio con tales propósitos pareciera poder objetarse el hecho de que el léxico jurídico implica ante todo generalidad, lo que entraría en contradicción con la particularidad y excepcionalidad que caracteriza aquello que Antígona califica como nómos. Revisamos entonces qué implica para Antígona el entierro de su hermano y luego abordamos el asunto desde los estudios más recientes sobre la legalidad griega. En un contexto histórico en el cual tiene lugar un ordenamiento del sistema jurídico, que implica un cambio de actitud con respecto a las leyes no escritas frecuentemente asociadas a Antígona, la expresión nómos de este pasaje requiere la integración del trabajo filológico y los estudios del derecho griego, de la familia y de las relaciones de género en la Atenas del siglo V a.C.