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The standard description of electrokinetic phenomena deals with a particle whose charge is uniformly smeared over its surface and considers ion transport only within a Gouy–Chapman diffuse layer. Experimental studies with colloidal dispersions have shown that this model is not applicable to many systems. To encompass a wider class of behavior, the standard model was extended to include ion migration within the Stern layer, the region between the shear envelope and the rigid particle. Computations show that Stern layer transport increases the conductivity and dielectric response of suspensions as well as the magnitude of the ζ potential inferred from mobility measurements. Model predictions are compared with experimental measurements on two well-defined systems—colloidal silica and a polymer latex. The inclusion of surface transport processes markedly improves agreement between theory and the experimental data. For example, in situations where the standard theory underpredicts the measured dielectric increments by factors of 2 or 3, the dynamic Stern layer model yields results within 5% to 20% of the experimental data at frequencies in the kHz range. [ABSTRACT FROM AUTHOR]

Field trials were conducted in hill-country pastures in Canterbury, New Zealand, to evaluate the herbicide flupropanate on nassella tussock (Nassella trichotoma) and associated pasture species. Pastures at three sites (Banks Peninsula, Spotswood and Greta Valley) and sprayed with flupropanate at 0, 0.75, 1.49 or 2.98 kg a.i./ha in March 2012. Pasture species composition was assessed in November/December 2011 (before treatment) and in November 2012. Pasture damage was assessed 3.5, 8.5 and 12 months after treatment (MAT). Cover of pasture species was reduced by 43%, 89% and 12% at 8.5 MAT at 1.49 kg a.i./ha, compared to untreated, for the three sites, respectively. Bare ground increased 3-fold to 51%, and 2.5-fold to 79% at Banks Peninsula and Spotswood but did not increase at Greta Valley. Cover ofAsteraceaeweeds, mainly thistles, increased at all three sites. Results indicate that flupropanate was severely damaging to some important pasture species at some sites. [ABSTRACT FROM PUBLISHER]

The plurivorous ascomycete, Sclerotinia sclerotiorum, is being evaluated as a mycoherbicide for the biocontrol of Cirsium arvensein pastures. Increased inoculum levels potentially add to the risk of disease in susceptible crops sown at or near the biocontrol site. This paper summarises: (1) two series of experiments that quantify the survival of soilborne sclerotia in sheep-grazed pastures in the Canterbury province of New Zealand; (2) a survey of the natural sclerotium population densities in four contrasting agricultural activity strata; and (3) a model for predicting the time period for which susceptible crops should be withheld from a site following the cessation of biocontrol. In the first series of two experiments, mycoherbicide-induced populations of sclerotia were sampled annually for four years. Half-lives were estimated to be 395 and 218 days. In the second series of eight experiments, sclerotia were buried in mesh bags in four different soils for three to four years, and exhibited half-lives of 206-506 days. In the survey, the four strata were permanent pasture, arable crop/pasture rotation, continuous cropping and market garden. The estimated sclerotium density in the market garden stratum was 9m[sup -2] ; few sclerotia were found in the other three strata. Using the withholding period model, the average time for a biocontrol-induced sclerotium population to decay exponentially to a natural 'market garden' density of 9 sclerotia m[sup -2] was estimated to be four years, assuming an average initial density of 125 sclerotia m[sup -2] and an average half-life of 351 days. A conservative upper limit for the withholding period was estimated to be ten years. [ABSTRACT FROM AUTHOR]

The endemic New Zealand ground wētā (Hemiandrussp. ‘promontorius’) has a Naturally Uncommon conservation status. This is because of the paucity of information on its density and distribution. Here, the biology, density and distribution of a population of this wētā found in and around vineyards in the Awatere Valley, Marlborough was studied. Wētā density was assessed in vineyards, paddocks and shrublands in this valley. Soil moisture, penetration resistance, pH and organic matter were recorded at locations with and without wētā. Wētā density in vineyards was significantly higher than in either paddocks or shrub habitats. In vineyards, the density of this insect was significantly higher under-vines than in the inter-rows. Higher numbers of this wētā were found in moist soils that required lower force to burrow. Females laid an average of 55 eggs between March and April, which hatched in September. These findings highlight the intersection between agriculture and conservation. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports on the cross-linking of dried (<5% moisture) paracetamol alginate granules with calcium chloride solutions. The effect of calcium concentration, temperature of the treatment solution, stirring speed and time used during cross-linking of granules on water uptake by the granules during cross-linking and physical properties of the cross-linked and dried granules were studied. A full factorial study of these factors each at two levels was used (CaCl2·2H2O: 20, 100mg/ml; temperature: 25, 45° C; stirrer speed: 25, 240rpm; time: 1.5 and 5.5min) to treat dried stock granules (size: 0.8–1.0mm) containing the model drug paracetamol and sodium alginate powder (1:1) which were prepared using conventional aqueous granulation under low shear. In addition to SEM and photomicrography, the physical properties studied were water uptake during cross-linking, yield, aggregation behaviour, moisture content, drug content, early stage drug release [over 10s (R10) and the next 50s (R50)] and calcium and sodium content of the unwashed cross-linked granules. Dry granules were successfully cross-linked. The treatment factors significantly affected most of the response variables. The variables most affected were water uptake (78–254%), drug entrapment (58–86%), early release (R10: 1.2–6.4% and R50: 3.0–12.2%), granule aggregation (0–70%), calcium (6.02–12.4%) and sodium content (1.2–6.44%). SEM photographs suggest that low calcium treated granules were less porous in nature compared to high calcium treated granules. Low shear drug alginate granules can be cross-linked in dried state. The properties of the cross-linked granules can be modified by altering the treatment process. [Copyright &y& Elsevier]

Abstract: In two consecutive seasons, forage rape (Brassica napus L.) plants were exposed to short periods (240°C hr) of heat stress (30°C day/25°C night) during seed filling (80% seed moisture content = S1), at physiological maturity (50% seed moisture content = S2) and at both S1 plus S2 (=S3) in a Biotron before being returned to the field until seed harvest. Seeds were hand harvested at 14% seed moisture content and their quality assessed by measuring germination, seed vigour (using the accelerated ageing and conductivity tests) and seed mass (as determined by thousand seed weight). Heat stress at both S1 and S2 caused a small (<10%) but significant reduction in germination in both seasons. There was a significant heat stress timing interaction in the first but not the second season. Reductions in germination were a result of increased abnormal seedling production not seed death. All three heat stress treatments significantly reduced seed vigour, with S3>S2>S1. Seed mass was reduced by heat stress at S1 but not at S2. Variable seed vigour in high‐germinating New Zealand‐produced forage rapeseed lots is most likely explained by short periods of heat stress during seed development. [ABSTRACT FROM AUTHOR]

Analysis of the economics of managing Cirsium arvense in grazed pastures worldwide has been hampered by a lack of data on the within-year seasonal dynamics of the weed and its impact on the yield of palatable herbage. To redress this, the seasonal pattern in within-patch percentage ground cover of the weed was determined from measurements on 39 dairy and 66 sheep and/or beef cattle farms in New Zealand during 2009-2010 and 2010-2011. This pattern was then scaled using farmer estimates of peak whole-farm cover to derive mean monthly covers for dairy, beef, sheep/beef, sheep and deer farms. These monthly covers corresponded, respectively, to mean annual percentage covers of 2.7, 1.7, 3.0, 5.9 and 2.9% and to mean annual percentage losses in pasture growth (palatable herbage yield) of 3.6, 2.3, 4.0, 7.8 and 3.9%. The latter, in combination with 2011-2012 farm statistics, revealed that C. arvense caused a national loss in pastoral farm gross revenue in New Zealand in 2011-2012 of $685 million ($446 m dairy, $233 m sheep/beef, $6 m deer). Beyond the scope of this paper, the monthly covers and their corresponding monthly losses in pasture growth provide a basis for modelling the economic impacts of C. arvense and its management at a farm scale. More generally, the analytical method that we have developed is appropriate for evaluating the economic impact of any weed in a grazed pasture, particularly those exhibiting pronounced seasonal patterns in occupancy, such as annuals and deciduous perennials. [ABSTRACT FROM AUTHOR]

This study reports the potential of different polymers and polymer incorporation methods to inhibit crystallisation and maintain supersaturation of amorphous indomethacin (IND) in aqueous suspensions during storage. Three different polymers (poly(vinyl pyrrolidone) (PVP), hydroxypropyl methylcellulose (HPMC) and Soluplus® (SP)) were used and included in the suspensions either as a solid dispersion (SD) with IND or dissolved in the suspension medium prior to the addition of amorphous IND. The total concentrations of both IND and the polymer in the suspensions were kept the same for both methods of polymer incorporation. All the polymers (with both incorporation methods) inhibited crystallisation of the amorphous IND. The SDs were better than the predissolved polymer solutions at inhibiting crystallisation. The SDs were also better at maintaining drug supersaturation. SP showed a higher IND crystallisation inhibition and supersaturation potential than the other polymers. However, this depended on the method of addition. IND in SD with SP did not crystallise, nor did the SD generate any drug supersaturation, whereas IND in the corresponding predissolved SP solution crystallised (into the recently characterised η polymorphic form of the drug) but also led to a more than 20-fold higher IND solution concentration than that observed for crystalline IND. The ranking of the polymers with respect to crystallisation inhibition potential in SDs was SP ≫ PVP > HPMC. Overall, this study showed that both polymer type and polymer incorporation method strongly impact amorphous form stability and drug supersaturation in aqueous suspensions. [ABSTRACT FROM AUTHOR]

The weedy grass Nassella trichotoma (nassella tussock), historically an economically damaging invader of modified tussock grasslands in New Zealand, currently causes little if any reduction in farm production. This is a result of successful historical regional management programmes in which plants have been removed manually (by grubbing) each year before they seed. To inform a debate about the need for ongoing regional management, we developed a stage-structured spatially explicit integrodifference equation population model and linked this to a cost analysis. We used the model to compare the weed's future population trajectories and related regional control costs over 50 years under three alternative management scenarios. The total discounted (3% p.a.) costs of no management, three-yearly grubbing and continued annual grubbing were NZ $417 million, $736 million and $131 million respectively. These analyses indicate that annual grubbing of N. trichotoma returns a net benefit of $286 million ($417 - $131 million) compared with doing nothing and a net benefit of $605 million ($736 - $131 million) compared with a 3-yearly grubbing programme. These results support the continuation of annual grubbing as the long-term economically optimal management strategy for N. trichotoma on pastoral farms infested by the weed in New Zealand. [ABSTRACT FROM AUTHOR]

An experiment was conducted in New Zealand to assess the effect of creep grazing of lambs on their liveweight and resistance to endoparasites. Comparisons included creep versus non-creep grazing at two herbage allowances and regular anthelmintic drenching. Treatments commenced with 6-week-old twin reared lambs, and ceased when they were weaned at 13 weeks, with the exception of the drench treatment which continued post-weaning. Pastures used contained sheep endoparasites. At 8 weeks post-weaning one lamb from each twin set was slaughtered, remaining lambs were then drenched, and 8 and 9 days later were orally dosed with 180 Trichostrongylus colubriformis L3/kg liveweight each day (averaging 12 650/lamb). Three weeks later these lambs were also slaughtered. Measurements included liveweight, faecal worm egg count (FEC) and adult endoparasite numbers. Neither herbage allowance nor creep grazing affected FEC or adult endoparasite numbers. Fortnightly drenching of creep grazed lambs on the high allowance had no effect on weaning liveweight, but it improved liveweights post-weaning. Neither creep grazing, pre-weaning herbage allowance, nor drenching, affected lamb resistance to endoparasites. Creep grazing and the higher allowance both increased weaning liveweights. The response to creep grazing was highest at the lower allowance, increasing weaning liveweights by 4 kg. Pre-weaning treatment had no effect on post-weaning growth rate. [ABSTRACT FROM AUTHOR]

Abstract: Powder samples of ranitidine hydrochloride forms 1 and 2 were milled using a vibrational ball mill (Retsch MM301) for periods up to 240min at 4, 12 and 35°C. X-ray powder diffraction (XRPD), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), solid-state nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC) were used to monitor solid-state properties of the milled samples. Milling of form 1 at 4°C led to a powder temperature of 36°C in the milling chamber and produced only amorphous drug; at 12°C (powder temperature 45°C) and at 35°C (powder temperature 62°C) progressive transformation of form 1 via amorphous drug to form 2 occurred. DSC of the milled samples showed a glass transition at 13–30°C and a crystallization exotherm (T c) between 30 and 65°C if the sample contained amorphous drug. The behaviour of the solid was speculated to be influenced by the relationship between powder temperature and T c; at powder temperatures below T c, amorphous drug is formed but no crystallization of form 2 occurs; at temperatures close to T c, amorphous content initially increases with transformation to form 2 on continued milling. At temperatures much higher than T c, at intermediate stages, less amorphous drug but both form 1 and form 2 are recovered, but continued milling gives only form 2. Form 2 did not transform to form 1 under any conditions used in this study. [Copyright &y& Elsevier]