Grond‐ en afloopverlies bepalings vanaf natuurlike veld,met behulp van ‘n reënvalnabootser

Uittreksel

‘n Oorhoofse roterende reënvalnabootser is gebruik om die sediment‐ en afloopverliese vanaf natuurlike veld in verskillende suksessiestadia en teen verskillende hellings te bepaal.

Soveel as 94,34% van die toegediende hoeveelheid water en 5,74 t/ha sediment het verlore gegaan vanaf ‘n pionierbedekte veld met ‘n 2,42% helling. Die basale bedekking het van al die veranderlikes betrokke, die grootste bydrae tot afloopverliese gelewer, terwyl die helling ‘n nie‐betekenisvolle rol gespeel het. Beide basale bedekking en helling het ‘n betekenisvolle (P < 0,05) invloed op die hoeveelheid sedimentverliese, vanaf natuurlike veld gehad.

‘n Hoogsbetekenisvolle verwantskap tussen basale bedekking met sediment‐ (r² = 0,68) en afloopverliese (r² = 0,69) is verkry, terwyl die helling geen betekenisvolle verwantskap met sediment‐ en afloopverliese getoon het nie.     

What is your diagnosis? Shoulder mass in a dog with lameness

Abstract: An adult castrated male Golden Retriever of unknown age was presented with a history of weight loss and progressive left thoracic limb lameness. On physical examination, a solid mass was palpated on the left scapula that had areas of lysis on radiographs and an area of cortical bone loss on ultrasound. Hepatomegaly, abdominal distension, and numerous intra‐abdominal soft tissue masses were also found. Fine‐needle aspirates of the scapula and several abdominal masses contained numerous free nuclei mixed with fewer individualized, intact cells that were round in shape and rarely formed small sheets. The cells had high nuclear to cytoplasmic ratios, central nuclei, coarsely stippled chromatin, 1–2 prominent nucleoli, and basophilic cytoplasm with indistinct cell borders. The cytopathologic interpretation was neuroendocrine neoplasia, either metastatic or multicentric. The dog was subsequently euthanized and based on gross and histologic findings at necropsy, a diagnosis of pheochromocytoma with multiple metastases was made. The neoplastic cells stained positive with Grimelius stain and were immunoreactive for synaptophysin and chromogranin A. Pheochromocytomas are rare tumors in dogs and uncommonly undergo distant metastasis, especially to bone.     

A prospective comparison between stabilized glutaraldehyde and chlorhexidine gluconate for preoperative skin antisepsis in dogs

OBJECTIVE: To compare the efficacy of 0.3% stabilized glutaraldehyde and alcohol (SG+A), 0.3% SG and water (SG+W), and 4% chlorhexidine gluconate tincture (CG+A), as skin disinfectants in dogs undergoing ovariohysterectomy. STUDY DESIGN: Prospective, blinded clinical study. ANIMALS: One hundred and twenty-one dogs. METHODS: Cutaneous bacterial colony forming units (CFU) from the perioperative site after skin preparation, after antisepsis, and after surgery (incisional and paramedian), were quantified. The influence of high initial bacterial counts (> or =150 CFU) and surgical time on antibacterial efficacy was examined and the proportion of dogs from which Staphylococcus intermedius was cultured, determined. Perioperative skin reactions and wound infections were documented. RESULTS: All 3 antiseptic solutions significantly and equally reduced CFU to all post-antisepsis sampling levels irrespective of surgical duration (mean surgical times 151.6, 136.2, and 149.6 minutes for CG+A, SG+A and SG+W, respectively). Median percentage reductions in CFU ranged between 99.3% and 100%. In dogs with initial high counts and disinfected with CG+A and SG+W, the incisional samples had significantly higher counts than the post-antisepsis samples. In the CG+A and SG+W groups, the proportion of post-surgery samples yielding S. intermedius was significantly higher at the incisional than the paramedian sites. Eight mild cutaneous reactions were recorded in equal proportions for the 3 solutions. There were no recorded infections. CONCLUSIONS: All 3 preparations had an equal ability to reduce and maintain low CFU counts, with minimal cutaneous reactions. CLINICAL RELEVANCE: SG solutions are safe and effective preoperative skin antiseptics for elective clean-contaminated surgical procedures.     

Toepassíng van ‘n gronderosievergelyking op natuurlike veld van die sentrale oranje‐vrystaat

Uittreksel

‘n Oorhoofse roterende rcënvalnabootscr is gebruik orn numericse waardes vir sekere faktore van die universele gronderosi‐evcrgelyking vas te stel. Alhocwei dit tydens hierdie Studie nodig was om sekere belangrike aannames te maak, het die afgeleide data betekenisvol ooreengestem met die reënvalnabootserrcsultate. Dit het veral betrckking op gronderodeerbaarheid en die bedekking en bestuursfaktor.

‘n Voorbeeld vir die gebruik van die universele gronderosievergelyking vir die beraming van grondverliese onder natuurlike veldtoestande, word uiteengesit. Die berekende grondverlies vanaf ‘n pioniergrasbedekking (2% basale bedekking) op ‘n Huttongrondvorm en ‘n 4% helling in die Sentrale Oranje‐Vrystaat, bedra tot 3,86 t/ha/jaar teenoor slegs 0,61 t/ha/jaar vanaf ‘n klimaksbedekking (6% basale bedekking) op dieselfdc helling en grondvorm. Die berekende grondverliese vanaf ‘n Hutton‐ en Valsriviergrondvorm het nie betekenisvol van mekaar verskil nie.     

Variability of yellow tulp (Moraea pallida Bak.) toxicity

Yellow tulp (Moraea pallida Bak.), collected predominantly during the flowering stage from a number of sites in South Africa, showed large variation in digoxin equivalent values, indicating variability in yellow tulp toxicity. Very low values were recorded for tulp collected from certain sites in the Northern Cape.     

Leaf rust and stripe rust resistance genes Lr54 and Yr37 transferred to wheat from Aegilops kotschyi

The tendency of unpaired meiotic chromosomes to undergo centric misdivision was exploited to translocate leaf rust and stripe rust resistance genes from an Aegilops kotschyi addition chromosome to a group 2 chromosome of wheat. Monosomic and telosomic analyses showed that the translocation occurred to wheat chromosome arm 2DL. The introgressed region did not pair with the corresponding wheat 2DL telosome during meiosis suggesting that a whole arm may have been transferred. Female transmission of the resistance was about 55% whereas male transmission was strongly preferential (96%). The symbols Lr54 and Yr37 are proposed to designate the new resistance genes.     

The effect of form and level of inorganic N on nitrogen use efficiency of sugarcane grown in pots

To-date, assessments of nitrogen use efficiency (NUE) of sugarcane have not included the contribution of its components, nitrogen uptake efficiency (NUpE) and nitrogen utilization efficiency (NUtE). This study determined these values, based on biomass and plant nitrogen (N) content, in two four-month-old pot-grown genotypes. The treatments included six N regimes, with nitrate (NO₃^—N) or ammonium (NH₄⁺-N) supplied alone, or as NO₃^?-N for the first 6 weeks and then NH₄⁺-N until harvest, each as 4 or 20 mM. Regardless of the N form, NUE was higher at four than at 20 mM due to significantly higher NUpE at low N supply. The results indicated that there was luxury N uptake and preference for NH₄⁺-N nutrition, which resulted in the highest determined NUE. There were significant differences between genotypes in biomass, morphological growth parameters, N uptake, total plant N and NUE, the latter matching previously established sucrose yield-based NUE field rankings.