Rethinking the externality issue for dryland salinity in Western Australia

Dryland salinity has been conceived of as a problem involving massive off‐site impacts and therefore requiring coordinated action to ensure that land managers reduce those off‐site impacts. In economic terms, salinity is seen as a problem of market failure due to externalities, including external costs from one farmer to another and from the farm sector to the non‐farm sector. In this article, we argue that, at least in Western Australia (WA), externalities are much less important as a cause of market failure than has been widely believed. If all externalities from salinity in WA were to be internalised, the impact on farm management would be small.Land Economics/Use,

Low-Input Heifer Development Using Stockpiled Native Forages and Protein Supplementation

Three studies were conducted to determine the effects of stockpiled winter forage species and protein supplementation strategy on heifer growth, reproductive performance, nutritional status, rumen fermentation, and the economic implications of forage-based heifer development. In all three studies, spring-born, beef heifers were stratified by BW and randomly assigned to 1 of 3 stockpiled forages: (1) endophyte-infected tall fescue (TF, Schedonorus arundinaceus (Schreb.) Dumort) (2) big bluestem (Andropogon gerardi Vitman) and indiangrass (Sorghastrum nutans L.) combination (BI), or (3) switchgrass (SG, Panicum virgatum L.). Forage treatments were randomly allocated to receive 1 of 2 supplement types: (1) 0.68 kg·heifer-1·d-1 of dried distiller’s grains with solubles (DDGS) or (2) 0.22 kg·heifer-1·d-1 of blood meal and fish meal (BF), resulting in a 3 × 2 factorial arrangement of treatments. Treatments were initiated in January and concluded in April at the onset of the breeding season. In Exp. 1, BW was greater (P \u3c 0.01) for TF heifers, resulting from an increased (P \u3c 0.01) ADG from initiation to breeding for TF heifers. From January to April, heifers grazing SG and BI pastures had a negative ADG; however, from breeding to final pregnancy diagnosis, SG and BI heifers compensated and had greater (P \u3c 0.01) ADG than TF heifers. Pregnancy rates at fixed timed-AI and overall pregnancy rates did not differ (P ≥ 0.38) by forage or supplement treatment. In Exp. 2, heifers grazing SG pastures had greater (P = 0.04) ruminal acetate concentrations than their counterparts. However, ruminal concentrations of propionate and butyrate were not influenced (P \u3e 0.32) by forage species. Due to an increase in ruminal acetate concentration, ruminal acetate:propionate ratio was greater (P = 0.04) for heifers grazing SG pastures. In Exp. 3, total cost of producing a heifer’s first calf using the three forage-based systems was $1,079 to$1,149/head with tall fescue (TF) being the most expensive forage-based heifer development forage system. Overall, low-input heifer development using stockpiled warm-season forages and protein supplementation may be a viable opportunity to extend the grazing season, lower production costs, and select for more efficient replacement females in the southeastern United States

Prebiotic, Probiotic, and Synbiotic Supplementation in Chronic Kidney Disease: A Systematic Review and Meta-analysis

Gut dysbiosis has been implicated in the pathogenesis of chronic kidney disease (CKD). Restoring gut microbiota with prebiotic, probiotic, and synbiotic supplementation has emerged as a potential therapeutic intervention but has not been systematically evaluated in the CKD population.This is a systematic review. A structured search of MEDLINE, CINAHL, EMBASE, Cochrane Central Register of Controlled Trials, and the International Clinical Trials Register Search Portal was conducted for articles published since inception until July 2017. Included studies were randomized controlled trials investigating the effects of prebiotic, probiotic, and/or synbiotic supplementation (>1\ua0week) on uremic toxins, microbiota profile, and clinical and patient-centered outcomes in adults and children with CKD.Sixteen studies investigating 645 adults met the inclusion criteria; 5 investigated prebiotics, 6 probiotics, and 5 synbiotics. The quality of the studies (Grades of Recommendation, Assessment, Development and Evaluation) ranged from moderate to very low. Prebiotic, probiotic, and synbiotic supplementation may have led to little or no difference in serum urea (9 studies, 345 participants: mean difference [MD] -0.30\ua0mmol/L, 95% confidence interval [CI] -2.20 to 1.61, P\ua0=\ua0.76, I\ua0=\ua053%), indoxyl sulfate (4 studies, 144 participants: MD -0.02\ua0mg/dL, 95% CI -0.09 to 0.05, P\ua0=\ua0.61, I\ua0=\ua00%), and p-cresyl sulfate (4 studies, 144 participants: MD -0.13\ua0mg/dL, 95% CI -0.41 to 0.15, P\ua0=\ua0.35, I\ua0=\ua00%). Prebiotic supplementation may have slightly reduced serum urea concentration (4 studies, 105 participants: MD -2.23\ua0mmol/L, 95% CI -3.83 to -0.64, P\ua0=\ua0.006, I\ua0=\ua011). Of the 2 studies investigating microbiota changes, synbiotic interventions significantly increased Bifidobacterium. Supplement effects on clinical outcomes were uncertain.There is limited evidence to support the use of prebiotics, probiotics, and/or synbiotics in CKD management

The application of inelastic neutron scattering to investigate the interaction of methyl propanoate with silica

A modern industrial route for the manufacture of methyl methacrylate involves the reaction of methyl propanoate and formaldehyde over a silica-supported Cs catalyst. Although the process has been successfully commercialised, little is known about the surface interactions responsible for the forward chemistry. This work concentrates upon the interaction of methyl propanoate over a representative silica. A combination of infrared spectroscopy, inelastic neutron scattering, DFT calculations, X-ray diffraction and temperature-programmed desorption is used to deduce how the ester interacts with the silica surface

Neoarchean Mantle-derived Magmatism within the Repulse Bay Block, Melville Peninsula, Nunavut: Implications for Archean Crustal Extraction and Cratonization

SUMMARYThe Repulse Bay block (RBb) of the southern Melville Peninsula, Nunavut, lies within the Rae craton and exposes a large (50,000 km2) area of middle to lower crust. The block is composed of ca. 2.86 Ga and 2.73–2.71 Ga tonalite-trondhjemite-granodiorite (TTG) and granitic gneiss that was derived from an older 3.25 and 3.10 Ga crustal substrate. This period of crustal generation was followed by the emplacement of ca. 2.69–2.66 Ga enderbite, charnockite, and granitoid intrusions with entrained websterite xenoliths. These voluminous batholith-scale bodies (dehydrated and hydrated intrusions), and the associated websterite xenoliths, have similar whole rock geochemical properties, including fractionated light rare earth element (LREE)–heavy (H)REE whole rock patterns and negative Nb, Ti, and Ta anomalies. Dehydrated intrusions and websterite xenoliths also contain similar mineralogy (two pyroxene, biotite, interstitial amphibole) and similar pyroxene trace element compositions. Based on geochemical and mineralogical properties, the two lithologies are interpreted to be related by fractional crystallization, and to be the product of a magmatic cumulate processes. Reworking of the crust in a ca. 2.72 Ga subduction zone setting was followed by ca. 2.69 Ga upwelling of the asthenospheric mantle and the intrusion of massif-type granitoid plutons. Based on a dramatic increase in FeO, Zr, Hf, and LREE content of the most evolved granitoid components from the 2.69–2.66 Ga cumulate intrusion, we propose that those granitoid plutons were in part derived from a metasomatized mantle source enriched by fluids from the subducting oceanic slab that underwent further hybridization (via assimilation) with the crust. Large-scale, mantle-derived Neoarchean sanukitoid-type magmatism played a role in the development of a depleted lower crust and residual sub-continental lithospheric mantle, a crucial element in the preservation of the RBb.RÉSUMÉLe bloc de Repulse Bay (RBb) dans le sud de la péninsule de Melville, au Nunavut, est situé dans le craton de Rae et expose une large zone (50 000 km2) de croûte moyenne à inférieur. Ce bloc est composé de tonalite-trondhjémite-granodiorite (TTG) daté à ca. 2,86 Ga et 2,73–2,71 Ga, et de gneiss granitique dérivé d’un substrat crustal plus ancien daté à 3,25 Ga et 3,10 Ga. Cette période de croissance crustale a été suivie par la mise en place entre ca. 2,69 et 2,66 Ga d’intrusions d’enderbite, charnockite et de granitoïde incluant des xénolites d’entraînement de websterite. Ces intrusions de taille batholitique (intrusions déshydratées et hydratées) ainsi que les xénolites d’entraînement de websterite associés, ont des propriétés géochimiques sur roche totale semblables notamment leurs profils de fractionnement des terres rares légers (LREE) et des terres rares lourds (HREE) ainsi que leurs anomalies négatives en Nb, Ti et Ta. Les intrusions déshydratées et les xénolites de websterite ont aussi des minéralogies similaires (deux pyroxènes, biotite, amphibole interstitielle) ainsi que des compositions semblables en éléments traces de leurs pyroxènes. Étant donné leurs propriétés géochimiques et minéralogiques, ces deux lithologies sont interprétées comme provenant d’une cristallisation fractionnée, et comme étant le produit de processus d'accumulations magmatiques. Le remaniement de la croûte dans un contexte de subduction vers ca. 2,72 Ga, a été suivi vers ca. 2,69 Ga d’une remontée du manteau asthénosphérique et de l’intrusion de granitoïdes de type massif. D'après l’importante augmentation en FeO, Zr, Hf et LREE dans les granitoïdes les plus évolués du magmatisme ayant pris place entre ca. 2,69 Ga et 2,66 Ga, nous proposons que ces plutons aient été en partie dérivés d’une source mantélique métasomatisée enrichies par des fluides d’une plaque océanique en subduction et qui a subi une hybridation supplémentaire (par assimilation) avec la croûte. Le magmatisme néo-archéen de type sanukitoïde, dérivé du manteau et de grande échelle, a joué un rôle dans le développement d’une croûte inférieure et d’un manteau lithosphérique continental résiduel appauvri, un élément déterminant pour la préservation du RBb

Precise U-Pb ages for the cogenetic alkaline Mount LaTour and peraluminous Mount Elizabeth granites of the South Nepisiguit River Plutonic Suite, northern New Brunswick, Canada

The South Nepisiguit River Plutonic Suite consists of various phases of felsic to mafic plutonic rocks of early Devonian age in northern New Brunswick. The felsic portion of this intrusive suite includes a large pluton of homogeneous, peraluminous biotite granite (the Mount Elizabeth Granite), which is flanked on its western side by the alkaline Mount LaTour Granite. New in situ and mineral separate U-Pb Laser Ablation-Inductively Coupled Plasma Mass Spectro-metry analyses of monazite and zircon grains from both sides of the suite define a crystallization age of 417.3 ± 0.96 Ma for the Mount Elizabeth Granite and 417.7 ± 4.4 Ma for the Mount LaTour Granite. The new data confirm previous geochronological work and indicate a close temporal relationship between these felsic phases of this plutonic suite

Profitability of Developing Beef Heifers on Stockpiled Winter Forages

We estimate the profitability of developing heifers on one stockpiled cool-season grass and two stockpiled warm-season grasses during the winter months by comparing distributions of net present value (NPV) over an 11-year useful life. Furthermore, distributions of payback period and the break-even price for each calf over the heifer’s production life were generated for each forage species. These results are compared across forages as well as to a simulated drylot system for heifer development. Data comes from a grazing experiment in Tennessee, where heifers grazed big bluestem and Indian grass combination (BBIG), switchgrass (SW), or endophyte-infected tall fescue (TF) pastures. Total cost of producing the first calf from a heifer using the three forage-based systems was $1,079/ head to$1,149/head, with TF being the most expensive forage-based heifer development system, and the total cost to produce a calf from heifers developed in a drylot system ranged from $574 to$644/head higher than the forage-based systems. The NPV of heifers developed on forage ranged from $264 to$468/head, while heifers developed in a drylot system had an NPV of –$876/head. Payback period was estimated in years of age, and heifers in forage-based systems became profitable at 3–4 years of age, whereas heifers developed in a drylot were 9–10 years of age before they covered their investment cost. The results indicate that SW was the lowest risk and the most profitable forage species relative to TF. These findings suggest that low-input forage-based systems may be more profitable than drylot heifer development systems in the southeastern United States

Base-induced cyclisations of ortho-substituted nitro-aromatics

In Chapter I some of the chemical, biological and physical properties of purine analogues, particularly benzimidazole N-oxides, are briefly discussed. In Chapter II, the preparations of 4-, 5-, 6-, and 7-amino-1H-benzimidazole 3-oxides are described. The methods employed involve base-induced cyclisation of suitably protected aminonitrophenyl glycine derivatives (esters or nitriles) followed by hydrolysis of the ester or nitrile and decarboxylation. In Chapter III, attempts are made to prepare imidazopyridine N-oxides, an area of N-oxide chemistry little explored. Although few derivatives of this class of compound are synthesised, the preparation of the parent 3H-imidazo[4 ,5-b]pyridine 1-oxide is accomplished. In Chapter IV, the possibility of preparing 1-methylbenzimidazole 3-oxides by the methods used in Chapters II and III is investigated, but unexpected results are obtained e.g. cyclisation of O-nitropheny1-sarcosine esters gives 1-hydroxy-4-methylquinoxaline-2, 3-diones. These reactions have instigated an investigation into the general mechanism for the base-induced cyclisations discussed in this thesis