Interactions between butterfly pea (Clitoria ternatea) and rubber vine (Cryptostegia grandiflora)

The arutors studied the impact of a forage legume, butterfly pea, on rubber vine at the early establishment phase under seven planting combinations at three nitrogen fertiliser levels. In pure stands, both species increased their shoot and root dry weight yield in response to nitrogen but rubber vine exhibited the greater response. In mixed stands, rubber vine and butterfly pea did not compete with each other at any nitrogen level. An over-yielding response resulted in all mixture combinations in terms of shoot and root yields. Total shoot and root mass of mixed stands significantly out-yielded their highest yielding pure stands by 8% and 27% respectively, suggesting that butterfly pea not only failed to reduce shoot and root growth of rubber vine, but actually improved its growth performance. Consequently, the introduction of butterfly pea to suppress rubber vine is not warranted.

Poor adoption of ley-pastures in south-west Queensland: biophysical, economic and social constraints.

The present review identifies various constraints relating to poor adoption of ley-pastures in south-west Queensland, and suggests changes in research, development and extension efforts for improved adoption. The constraints include biophysical, economic and social constraints. In terms of biophysical constraints, first, shallower soil profiles with subsoil constraints (salt and sodicity), unpredictable rainfall, drier conditions with higher soil temperature and evaporative demand in summer, and frost and subzero temperature in winter, frequently result in a failure of established, or establishing, pastures. Second, there are limited options for legumes in a ley-pasture, with the legumes currently being mostly winter-active legumes such as lucerne and medics. Winter-active legumes are ineffective in improving soil conditions in a region with summer-dominant rainfall. Third, most grain growers are reluctant to include grasses in their ley-pasture mix, which can be uneconomical for various reasons, including nitrogen immobilisation, carryover of cereal diseases and depressed yields of the following cereal crops. Fourth, a severe depletion of soil water following perennial ley-pastures (grass + legumes or lucerne) can reduce the yields of subsequent crops for several seasons, and the practice of longer fallows to increase soil water storage may be uneconomical and damaging to the environment. Economic assessments of integrating medium- to long-term ley-pastures into cropping regions are generally less attractive because of reduced capital flow, increased capital investment, economic loss associated with establishment and termination phases of ley-pastures, and lost opportunities for cropping in a favourable season. Income from livestock on ley-pastures and soil productivity gains to subsequent crops in rotation may not be comparable to cropping when grain prices are high. However, the economic benefits of ley-pastures may be underestimated, because of unaccounted environmental benefits such as enhanced water use, and reduced soil erosion from summer-dominant rainfall, and therefore, this requires further investigation. In terms of social constraints, the risk of poor and unreliable establishment and persistence, uncertainties in economic and environmental benefits, the complicated process of changing from crop to ley-pastures and vice versa, and the additional labour and management requirements of livestock, present growers socially unattractive and complex decision-making processes for considering adoption of an existing medium- to long-term ley-pasture technology. It is essential that research, development and extension efforts should consider that new ley-pasture options, such as incorporation of a short-term summer forage legume, need to be less risky in establishment, productive in a region with prevailing biophysical constraints, economically viable, less complex and highly flexible in the change-over processes, and socially attractive to growers for adoption in south-west Queensland.

Water and thermal regimes for field pea in Australia and their implications for breeding.

There is a large gap between the refined approaches to characterise genotypes and the common use of location and season as a coarse surrogate for environmental characterisation of breeding trials. As a framework for breeding, the aim of this paper is quantifying the spatial and temporal patterns of thermal and water stress for field pea in Australia. We compiled a dataset for yield of the cv. Kaspa measured in 185 environments, and investigated the associations between yield and seasonal patterns of actual temperature and modelled water stress. Correlations between yield and temperature indicated two distinct stages. In the first stage, during crop establishment and canopy expansion before flowering, yield was positively associated with minimum temperature. Mean minimum temperature below similar to 7 degrees C suggests that crops were under suboptimal temperature for both canopy expansion and radiation-use efficiency during a significant part of this early growth period. In the second stage, during critical reproductive phases, grain yield was negatively associated with maximum temperature over 25 degrees C. Correlations between yield and modelled water supply/demand ratio showed a consistent pattern with three phases: no correlation at early stages of the growth cycle, a progressive increase in the association that peaked as the crop approached the flowering window, and a progressive decline at later reproductive stages. Using long-term weather records (1957-2010) and modelled water stress for 104 locations, we identified three major patterns of water deficit nation wide. Environment type 1 (ET1) represents the most favourable condition, with no stress during most of the pre-flowering phase and gradual development of mild stress after flowering. Type 2 is characterised by increasing water deficit between 400 degree-days before flowering and 200 degree-days after flowering and rainfall that relieves stress late in the season. Type 3 represents the more stressful condition with increasing water deficit between 400 degree-days before flowering and maturity. Across Australia, the frequency of occurrence was 24% for ET1, 32% for ET2 and 43% for ET3, highlighting the dominance of the most stressful condition. Actual yield averaged 2.2 t/ha for ET1, 1.9 t/ha for ET2 and 1.4 t/ha for ET3, and the frequency of each pattern varied substantially among locations. Shifting from a nominal (i.e. location and season) to a quantitative (i.e. stress type) characterisation of environments could help improving breeding efficiency of field pea in Australia.

Effect of substituent on the thermodynamics of D-glucopyranoside binding to concanavalin A, pea (Pisum sativum) lectin and lentil (Lens culinaris) lectin

Titration calorimetry measurements of the binding of phenyl-alpha (alpha PhOGlu), 3-methoxy (3MeOGlu), fluorodeoxy and deoxy derivatives of alpha-D-glucopyranose (Glu) to concanavalin A (conA), pea lectin and lentil lectin were performed at approx. 10 and 25 degrees C in 0.01 M dimethylglutaric acid/NaOH buffer, pH 6.9, containing 0.15 M NaCl and Mn2+ and Ca2+ ions. Apparently the 3-deoxy, 4-deoxy and 6-deoxy as well as the 4-fluorodeoxy and 6-fluorodeoxy derivatives of Glu do not bind to the lectins because no heat release was observed on the addition of aliquots of solutions of these derivatives to the lectin solutions. The binding enthalpies, delta H0b, and entropies, delta S0b, determined from the measurements were compared with the same thermodynamic binding parameters for Glu, D-mannopyranoside and methyl-alpha- D-glucopyranoside (alpha MeOGlu). The binding reactions are enthalpically driven with little change in the heat capacity on binding, and exhibit enthalpy-entropy compensation. Differences between the thermodynamic binding parameters can be rationalized in terms of the interactions apparent in the known crystal structures of the methyl-alpha-D-mannopyranoside-conA [Derewenda, Yariv, Helliwell, Kalb (Gilboa), Dodson, Papiz, Wan and Campbell (1989) EMBO J. 8, 2189-2193] and pea lectin-trimanno-pyranoside [Rini, Hardman, Einspahr, Suddath and Carber (1993) J. Biol. Chem. 268, 10126-10132] complexes. Increases in the entropy change on binding are observed for alpha MeOGlu binding to pea and lentil lectin, for alpha PhOGlu binding to conA and pea lectin, and for 3MeOGlu binding to pea lectin relative to the entropy change for Glu binding, and imply that the phenoxy and methoxy substituents provide additional hydrophobic interactions in the complex. Increases in the binding enthalpy relative to that of Glu are observed for deoxy and fluoro derivatives in the C-1 and C-2 positions and imply that these substituents weaken the interaction with the surrounding water, thereby strengthening the interaction with the binding site.

Thermodynamics of monosaccharide binding to concanavalin A, pea (Pisum sativum) lectin, and lentil (Lens culinaris) lectin

Titration calorimetry measurements of the binding of methyl alpha-D-mannopyranoside (Me alpha Man), D-mannopyranoside (Man), methyl alpha-D-glucopyranoside (Me alpha Glu), and D-glucopyranoside (Glu) to concanavalin A (Con A), pea lectin, and lentil lectin were performed at 281 and 292 K in 0.01 M dimethylglutaric acid-NaOH buffer (pH 6.9) containing 0.15 M NaCl and Mn+2 and Ca+2 ions. The site binding enthalpies, delta H, are the same at both temperatures and range from -28.4 +/- 0.9 (Me alpha Man) to -16.6 +/- 0.5 kJ mol-1 (Glu) for Con A, from -26.2 +/- 1.1 (Me alpha Man) to -12.8 +/- 0.4 kJ mol-1 (Me alpha Glu) for pea lectin, and from -16.6 +/- 0.7 (Me alpha Man) to -8.0 +/- 0.2 kJ mol-1 (Me alpha Glu) for lentil lectin. The site binding constants range from 17 +/- 1 x 10(3) M-1 (Me alpha Man to Con A at 281.2 K) to 230 +/- 20 M-1 (Glu to lentil lectin at 292.6 K) and exhibit high specificity for Con A where they are in the Me alpha Man:Man:Me alpha Glu:Glu ratio of 21:4:5:1, while the corresponding ratio is 5:2:1.5:1 for pea lectin and 4:2:2:1 for lentil lectin. The higher specificity for Con A indicates more interactions between the amino acid residues at the binding site and the carbohydrate ligand than for the pea and lentil lectin-carbohydrate complexes. The carbohydrate-lectin binding results exhibit enthalpy-entropy compensation in that delta Hb (kJ mol-1) = -1.67 +/- 0.06 x 10(4) + (1.30 +/- 0.12)T(K) delta Sb (J mol-1K-1). Differential scanning calorimetry measurements on the thermal denaturation of the lectins and their carbohydrate complexes show that the Con A tetramer dissociates into monomers, while the pea and lentil lectin dimers dissociate into two submonomer fragments. At the denaturation temperature, one carbohydrate binds to each monomer of Con A and the pea and lentil lectins. Complexation with the carbohydrate increases the denaturation temperature of the lectin and the magnitude of the increases yield binding constants in agreement with the determinations from titration calorimetry.

Computer simulation of protein—carbohydrate complexes: application to arabinose-binding protein and pea lectin

The CCEM method (Contact Criteria and Energy Minimisation) has been developed and applied to study protein-carbohydrate interactions. The method uses available X-ray data even on the native protein at low resolution (above 2.4 Å) to generate realistic models of a variety of proteins with various ligands.The two examples discussed in this paper are arabinose-binding protein (ABP) and pea lectin. The X-ray crystal structure data reported on ABP-β-l-arabinose complex at 2.8, 2.4 and 1.7 Å resolution differ drastically in predicting the nature of the interactions between the protein and ligand. It is shown that, using the data at 2.4 Å resolution, the CCEM method generates complexes which are as good as the higher (1.7 Å) resolution data. The CCEM method predicts some of the important hydrogen bonds between the ligand and the protein which are missing in the interpretation of the X-ray data at 2.4 Å resolution. The theoretically predicted hydrogen bonds are in good agreement with those reported at 1.7 Å resolution. Pea lectin has been solved only in the native form at 3 Å resolution. Application of the CCEM method also enables us to generate complexes of pea lectin with methyl-α-d-glucopyranoside and methyl-2,3-dimethyl-α-d-glucopyranoside which explain well the available experimental data in solution.

Algunas reflexiones a partir de la Ley de Muerte Digna

El Senado Nacional sancionó recientemente una ley llamada “Ley de Muerte Digna”, la cual nos invita a hacer algunas reflexiones. La primera es llamar la atención justamente sobre el hecho de que la ley no trata de la muerte (como lo hace la Ley Nº 24.193 sobre trasplantes de órganos que deja estipulado, entre otras cosas, cómo se debe constatar la muerte), sino de la vida de las personas cuya salud se encuentra seriamente comprometida y que en muchos casos, no siempre, se presupone que se encuentra próxima a la muerte.

Ley natural, diálogo social y convicciones creyentes

Resumen: El artículo plantea una lectura transversal del Documento de la Comisión Teológica Internacional, titulado “En busca de una ética universal: una nueva mirada sobre la ley natural” de tal manera que, a partir del reconocimiento de una ley natural que subyace a toda norma, se procura mostrar cómo esa convicción no impide la participación de los cristianos en el diálogo social. El autor señala las paradojas a las que conduce la ética de la discusión y el lugar de la discusión pública como estímulo para alcanzar la verdad. Enfatiza la importancia del amor a la verdad como condición necesaria para que una sociedad sea noble y respetable. Considera el lugar del diálogo y el consenso y la existencia de una verdad última que la inteligencia puede captar en el marco de un sano pluralismo. También aborda la relación entre este pluralismo y las religiones y su contribución al debate público.

Actividades de las autoridades argentinas y la embajada española sobre los anarquistas antes de la Ley de Residencia

Resumen: El presente trabajo investiga la actuación de la Embajada de España con respecto a la entrada a la Argentina de inmigrantes con antecedentes anarquistas durante fines del siglo XIX y los primeros dos años del siglo XX. Registra además el interés por seguir los movimientos de dichos inmigrantes en el país. Se destaca el rol de la documentación diplomática, mediante la cual la Embajada española se mantenía en permanente contacto con el gobierno central, con las autoridades argentinas y con los consulados del interior para intercambiar información. A través de las fuentes se puede observar la labor de “inteligencia ideológica” que se realizó y el detallado conocimiento que se tenía sobre los anarquistas, sus vías de traslado hacia nuestro país, sus profesiones, paraderos, domicilios, relaciones, y las minuciosas descripciones físicas de los sospechados. En esta política se nota la coparticipación entre la Embajada de España y las instituciones argentinas para desligarse de elementos que denominaban “no deseados”. También se consideran las relaciones entre el anarquismo argentino y el español, así como la importancia de la prensa revolucionaria, aun sobre la misma España. La vigilancia que ejercía la Embajada española sobre los inmigrantes, el control sobre los anarquistas españoles en la Argentina y la influencia de éstos sobre los sucesos de la Península demuestran a las claras la preocupación del gobierno hispano en la cuestión.

La ley nueva y la nueva evangelización : la tradición tomista y la perspectiva moral de Evangelii gaudium

Resumen: Las indicaciones pastorales del Papa Francisco en Evangelii gaudium ofrecen la oportunidad para redescubrir el valor de la categoría ley bajo la guía de la tradición tomista recogida en el documento pontificio. La propuesta moral del Evangelio o ley nueva, siguiendo la sinonimia utilizada por santo Tomás de Aquino, no puede ser reducida a un precepto o una serie de normas; muy por el contrario, revisitando la doctrina del Doctor Común podemos descubrir la necesidad de una hermenéutica sapiencial y profundamente bíblica de uno de los pilares de la moral cristiana. En el camino de la conversión pastoral, el retorno a las fuentes tomistas vuelve a iluminar la reflexión teológica con fecundidad renovada.

La ley moral natural y ley positiva humana en el opúsculo “La filosofía jurídica del artículo 19 de la Constitución Nacional”, de Arturo Enrique Sampay

La Constitución Nacional reconoce un orden de conducta instituido por Dios y otro instituido por el Estado… el débito legal debe resultar conforme al débito moral. Si así no fuera, cualquier imposición del legislador no sería derecho sino un acto de violencia desnaturalizando el poder que el Estado tiene de reforzar con débito eventualmente coercible obligaciones emergentes de la virtud de la justicia. En este trabajo nos ocuparemos de la relación entre ley moral natural y la ley positiva humana a partir de las consideraciones que Arturo Enrique Sampay2 formula en su obra, La filosofía jurídica del Artículo 19 de la Constitución Nacional3. Sampay desarrolla el tópico principalmente con la inspiración de la doctrina de Tomás de Aquino.

Bajo Dios y bajo la ley : fundamentos de Derecho natural en el sistema del Common-law inglés

Resumen: El common-law inglés tiene una herencia cristiana increíblemente rica. Los juristas ingleses más prestigiosos –incluyendo a Blackstone, Coke y Fortescue– frecuentemente partían desde la fe cristiana a la hora de iluminar y desarrollar lo que ahora son ya principios bien establecidos de la doctrina del common-law. Por consiguiente, este sistema fue desarrollándose históricamente con una particular referencia a la tradición cristiana del derecho natural. Este artículo demuestra cómo el common-law inglés fue mayoritariamente inspirado y desarrollado por estos principios cristianos de la teoría del derecho natural y cómo estos principios todavía subsisten válidos para la interpretación del common-law aun en el presente.

Lecturas contemporáneas de la ley natural

Resumen: la teoría de la ley natural ha tenido un extenso desarrollo en la ética, más allá de lo jurídico, por lo que bien puede hablarse de una ética de la ley natural, con una vigencia desde su nacimiento en el pensamiento griego hasta la filosofía contemporánea. En este trabajo se atiende a la especial lectura que hacen los moralistas neo-analíticos de habla inglesa, quienes tratan, sistemática y/o históricamente, el tema de la ley natural, sea traduciéndola a su proceder epistemológico, sea en confrontación o crítica, sea desde una forma «sui generis» de reivindicación. Esto nos permite hablar de una vigencia de lo que su concepto significa: ser una ley que se sustenta en la naturaleza racional y universal de la humanidad