Sporobolus virginicus leaf salt glands: morphology and ultrastructure

The leaves of the halophytic, C4 grass, Sporobolus virginicus, possess bicellular salt glands that are more abundant on the adaxial surface. Each gland is composed of a voluminous, flask-shaped basal cell, embedded in the leaf and a smaller, dome-shaped cap cell that protrudes beyond the epidermis. An ornamented, porose cuticle overlies the protruding gland. The dense cytoplasm of the basal cell is partitioned into channels by a system of paired membranes which originate from invaginations of the plasma membrane, adjacent to the common wall between basal and cap cells. Closely associated with the partitioning membranes are numerous mitochondria, microtubules and endoplasmic reticulum. The basal cell is intimately connected to adjacent cap, epidermal and mesophyll cells by numerous plasmodesmata. The dense cytoplasm of the cap cell lacks partitioning membranes, but contains numerous small vacuoles and a concentration of organelles in close proximity to the outer surface. The basal cell appears to be suitably located and designed to access and direct ions from surrounding mesophyll and epidermal cells into the channels formed by the partitioning membranes. Subsequent ion movement is probably symptastic via the cytoplasm and plasmodesmata to the cap cell. The abundant mitochondria, which are closely associated with the partitioning membranes, are probably important in ion transport through the cytoplasm of the basal cell. The ions appear to be compartmentalised and transported across the cap cell in small vacuoles and accumulate in the cuticular cavity prior to elimination via cuticular pores or through rupture of the cuticle

Responses of the mangrove Rhizophora mucronata to high salinities and low osmotic potentials

The effect of solutions of seawater or non-saline polyethylene glycol (PEG)-6000 on dry mass, tissue water potential, stomatal resistance and inorganic solute uptake were investigated in the mangrove, Rhizophora mucronata Lam. Plants were treated with solutions of seawater or PEG-6000 at osmotic potentials of −0,05, −0,5, −1,2 and −2,4 MPa for three weeks. Generally, effects of salinity and PEG-6000 were similar. Low external osmotic potentials decreased root mass, lowered tissue water potentials, increased stomatal resistance and influenced distribution of Na, K, Ca and Mg in tissues. The similarity of the responses of the plants to salinity and PEG-6000 suggests that the effects of salinity are mediated primarily through low osmotic potentials and not by salinity per se

Prosecuting “hate”: An overview of problem areas relating to hate crimes and challenges to criminal litigation

Several calls, from a wide spectrum of sectors for the enactment of hate-crime legislation in South Africa, suggest that there is limited knowledge about the theoretical underpinnings of this area of criminal law and of the practical problems associated with the implementation of hate-crime laws. This submission briefly examines the origins of hate-crime laws and attempts, by using existing American sources, to provide a conceptual framework for hate crimes. The different models of hate-crime laws, definitional issues and the controversies associated with hate-crime laws are considered. These controversies include disagreements about the use of the term ‘hate’, the inclusion of victim categories, and the consideration of motive as a requirement of hate crimes. The article also considers practical problems associated with the implementation of hate-crime laws. These problems could commence at the complaint stage when evidence of bias has to be established by law-enforcement officers, and extend to the trial stage, when the role of victims must be considered, when plea bargaining is a possibility and when bias has to be proved in court

Towards new indicators of disadvantage: deprivation and social exclusion

Studies of Australian poverty have concentrated on comparing people\u27s incomes with poverty lines. By focusing on income alone, poverty research has failed to connect with the actual living standards experienced by those in poverty. This paper addresses the broader issues of poverty and is the final report from stage 2 of a major project assisted by a Linkages grant from the Australian Research Council, and led by Professor Peter Saunders from the Social Policy Research Centre of the University of New South Wales, with Janet Taylor (Brotherhood of St Laurence) and Peter Davidson (ACOSS) as partner investigators. Mission Australia and Anglicare NSW are other industry partners

The effects of HIV/AIDS on the clinical profile and outcomes post pericardiectomy of patients with constrictive pericarditis: a retrospective review.

OBJECTIVE: The clinical profile and surgical outcomes of patients with constrictive pericarditis were compared in HIV-positive and -negative individuals. METHODS: This study was a retrospective analysis of patients diagnosed with constrictive pericarditis at Inkosi Albert Luthuli Central Hospital, Durban, over a 10-year period (2004-2014). RESULTS: Of 83 patients with constrictive pericarditis, 32 (38.1%) were HIV positive. Except for pericardial calcification, which was more common in HIV-negative subjects (n = 15, 29.4% vs n = 2, 6.3%; p = 0.011), the clinical profile was similar in the two groups. Fourteen patients died preoperatively (16.9%) and three died peri-operatively (5.8%). On multivariable analysis, age (OR 1.17; 95% CI: 1.03-1.34; p = 0.02), serum albumin level (OR 0.63; 95% CI: 0.43-0.92; p = 0.016), gamma glutamyl transferase level (OR 0.97; 95% CI: 0.94-0.1.0; p = 0.034) and pulmonary artery pressure (OR 1.49; 95% CI: 1.07-2.08; p = 0.018) emerged as independent predictors of pre-operative mortality rate. Peri-operative complications occurred more frequently in HIV-positive patients [9 (45%) vs 6 (17.6%); p = 0.030]. CONCLUSIONS: Without surgery, tuberculous constrictive pericarditis was associated with a high mortality rate. Although peri-operative complications occurred more frequently, surgery was not associated with increased mortality rates in HIV-positive subjects

Predictors of post-operative outcomes in patients with peripheral arterial disease and critical limb ischaemia: a systematic review and meta-analysis

Background: A very small proportion (1%) of patients with peripheral artery disease (PAD) present with critical limb threatening ischaemia (CLTI) with poor prognosis. The present review showcased several pre-operative predictors and key post-operative outcomes. Identification of any modifiable predictors may impact positively on surgical outcomes.Design: PubMed/Medline, Google scholar and Cochrane databases were searched using terms such as “peripheral arterial disease” AND “critical limb ischemia,” “post-operative outcome,” AND “predictors of post-operative outcomes”. Search was for relevant English-language articles published between January 1997 and December 2007 Selected articles were screened first by title and abstract, and selection of full articles was based on relevance using our inclusion and exclusion criteria and quality ratings performed with the MINORS score.Results: The included studies were published between 1997 and 2007. Only six (6) articles out of a total of 2,114 were deemed suitable for analysis. Ambulatory recovery was >70% at six months, 86.7% and 70.0% at one year and five years respectively. Rate of local wound complications was between 12% and 24%. Reported limb salvage rates were >90% at six months, >70% at one year and 70.0-90.0% at five years. Primary graft patency rate at one year ranged from 63% and 76.6%. Gangrene, diabetes and impaired pre-operative ambulatory function are associated with more wound complications, low limb salvage, reduced graft patency and poor functional outcome.Conclusion: Pre-operative ambulatory status was the most important predictor of post-operative ambulatory recovery. Diabetes mellitus was an important risk factor for prolonged wound healing, local wound complications and major amputation

Hepatic amoebiasis

Thirty-two cases of hepatic amoebiasis with some unusual features are presented. The clinical spectrum and the value of investigations such as liver scanning, angiography and slide agglutination test are presented. Therapy is outlined.S. Afr. Med. J., 48, 1159 (1974