A universal equation to predict methane production of forage-fed cattle in Australia

The methods for estimating methane emissions from cattle as used in the Australian national inventory are based on older data that have now been superseded by a large amount of more recent data. Recent data suggested that the current inventory emissions estimates can be improved. To address this issue, a total of 1034 individual animal records of daily methane production (MP) was used to reassess the relationship between MP and each of dry matter intake (DMI) and gross energy intake (GEI). Data were restricted to trials conducted in the past 10 years using open-circuit respiration chambers, with cattle fed forage-based diets (forage >70%). Results from diets considered to inhibit methanogenesis were omitted from the dataset. Records were obtained from dairy cattle fed temperate forages (220 records), beef cattle fed temperate forages (680 records) and beef cattle fed tropical forages (133 records). Relationships were very similar for all three production categories and single relationships for MP on a DMI or GEI basis were proposed for national inventory purposes. These relationships were MP (g/day) = 20.7 (±0.28) × DMI (kg/day) (R2 = 0.92, P < 0.001) and MP (MJ/day) = 0.063 (±0.008) × GEI (MJ/day) (R2 = 0.93, P < 0.001). If the revised MP (g/day) approach is used to calculate Australia’s national inventory, it will reduce estimates of emissions of forage-fed cattle by 24%. Assuming a global warming potential of 25 for methane, this represents a 12.6 Mt CO2-e reduction in calculated annual emissions from Australian cattle.

Fertilising for yield and quality in sown grass pastures and forage crops

Sown pasture rundown and declining soil fertility for forage crops are too serious to ignore with losses in beef production of up to 50% across Queensland. The feasibility of using strategic applications of nitrogen (N) fertiliser to address these losses was assessed by analysing a series of scenarios using data drawn from published studies, local fertiliser trials and expert opinion. While N fertilser can dramatically increase productivity (growth, feed quality and beef production gains of over 200% in some scenarios), the estimated economic benefits, derived from paddock level enterprise budgets for a fattening operation, were much more modest. In the best-performing sown grass scenarios, average gross margins were doubled or tripled at the assumed fertiliser response rates, and internal rates of return of up to 11% were achieved. Using fertiliser on forage sorghum or oats was a much less attractive option and, under the paddock level analysis and assumptions used, forages struggled to be profitable even on fertile sites with no fertiliser input. The economics of nitrogen fertilising on grass pasture were sensitive to the assumed response rates in both pasture growth and liveweight gain. Consequently, targeted research is proposed to re-assess the responses used in this analysis, which are largely based on research 25-40 years ago when soils were generally more fertile and pastures less rundown.

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.

Of plants and pikas: evidence for a climate-mediated decline in forage and cache quality

Background: Animals that hoard food to mediate seasonal deficits in resource availability might be particularly vulnerable to climate-mediated reductions in the quality and accessibility of food during the caching season. Central-place foragers might be additionally impacted by climatic constraints on their already restricted foraging range. Aims: We sought evidence for these patterns in a study of the American pika (Ochotona princeps), a territorial, central-place forager sensitive to climate. Methods: Pika food caches and available forage were re-sampled using historical methods at two long-term study sites, to quantify changes over two decades. Taxa that changed in availability or use were analysed for primary and secondary metabolites. Results: Both sites trended towards warmer summers, and snowmelt trended earlier at the lower latitude site. Graminoid cover increased at each site, and caching trends appeared to reflect available forage rather than primary metabolites. Pikas at the lower latitude site preferred species higher in secondary metabolites, known to provide higher-nutrient winter forage. However, caching of lower-nutrient graminoids increased in proportion with graminoid availability at that site. Conclusions: If our results represent trends in climate, cache quality and available forage, we predict that pikas at the lower latitude site will soon face nutritional deficiencies.

La Ley Saénz Peña, una cuestión de familia

En el presente año se ha cumplido el centenario de la ley más célebre en materia de emisión del voto, es decir, la llamada Ley Sáenz Peña. Y este aniversario encuentra al voto, un aspecto clave de la vida institucional, en el centro mismo del debate, tanto en la Argentina como en gran parte del mundo. Por cuestiones tecnológicas, como el llamado voto electrónico, como acto jurídico, al discutirse su naturaleza imperativa, como hecho sociológico, vista la creciente reticencia de gran parte de la sociedad a participar de los actos electorales, y encontrar su representatividad en las llamadas “redes sociales”, por la aparición del denominado referéndum revocatorio, que en cierta medida implica poner en duda la eficacia del voto, y el demagógico proyecto de bajar a 16 años la edad hábil del sufragante, el mismo es hoy objeto de análisis, revisión y enfoques renovadores.

O Brasil no cenário internacional : uma peça em mais de mil atos (reflexos do debate parlamentar entre 4 de outubro de 1988 e 31 de dezembro de 2010)

Faz um mapeamento dos atos internacionais (tratados, convenções, convênios, acordos, protocolos, memorandos de entendimento etc.) assinados pela República Federativa do Brasil e encaminhados ao Congresso Nacional para apreciação legislativa, através de Mensagens do Presidente da República, entre a promulgação da Constituição de 1988 e julho de 2010, como um requisito essencial de inserção das normas de Direito Internacional Público no ordenamento jurídico positivo brasileiro. Questiona a possibilidade de inferência da participação parlamentar nesse processo a partir de um quadro de ação parlamentar assim elaborado. Tece, a partir das observações feitas, considerações a respeito do papel que o Congresso Nacional tem desempenhado nesse processo, através da Câmara dos Deputados.

Forage strategy of juvenile Lates niloticus (L.) in Lake Victoria, Kenya

Six KMFRI stations located in Nyanza Gulf of Lake Victoria (Kenya) were sampled in order to investigate the forage strategy of juvenile Lates niloticus. Thirty speciemens were collected using a bottom trawl at each station and sorted into three size classes 1-2 cm and 3-20 cm total length. Stomach contents were analysed and taxonomic keys used to identify zoplankton and other insects. Caridina nilotica was the dominant food item in both frequency of occurrence and numerical abundance. In fish examined from 1-2 cm T.L., cladocerans were prominent food items, while at 2-3 and 3-20 cm, C. nilotica was dominant

Length-weight relationships for some important forage crustaceans from South Africa

The diet of marine animals is usually determined by stomach content analysis. Although partially digested prey fragments can often be identified to species level, it is difficult to estimate the original mass of the prey organism. This information, however, is essential for calculating both the total food intake as well as the relative contribution of each prey item. In this study we present regression equations that can be used to estimate the original mass of 18 common South African crustaceans from various indigestible fragments such as the carapace (length and width), chelae (length and width of left and right dactylus) and eye (length and width).