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

Growth and characterisation of thin film superconductors on oxides, silicon and silicides

Includes bibliographical references.High Tc thin film superconductors are of great interest because of their potential applications, particularly in the microelectronics field. A successful superconductor microelectronic technology depends both on the ability to grow good quality superconducting thin films, and the need to incorporate these films into multilayer semiconductor devices. In this work the growth and characterisation of high Tc Y₁Ba₂Cu₃O₇ films by inverted cylindrical magnetron sputtering and pulsed ruby laser ablation on oxides, silicon and silicides is investigated. The inverted cylindrical magnetron sputter system has been effectively used to counter the problem of negative ion re-sputtering found in sputter deposition of oxide films. The optimal growth conditions for both these techniques have been determined. Rutherford backscattering spectrometry is used to obtain thickness and stoichiometry information, while X-ray diffraction gave phase and orientational data. Ion channeling was used for structural analysis and Auger electron spectroscopy was used to determine the homogeneity of the films

Diagnostic challenges with acellular bacterial meningitis

An immunocompetent adult presenting with acellular pneumococcal meningitis is a rare occurrence and may pose a diagnostic challenge

Are recent trends in poverty and deprivation in Australia consistent with trickle-down effects?

This article examines trends in social disadvantage in Australia over the decade to 2018 using two approaches: a monetary approach using poverty and a living standards approach using deprivation. We compare the two approaches, highlight their implications and assess whether the evidence produced by each is consistent with trickle-down effects. The estimates allow for variations in thresholds, the treatment of housing costs and relative and absolute measures. The findings indicate an overall decline in poverty that is dependent on the treatment of housing costs and a more consistent decline in deprivation but with little or no improvement for many experiencing poverty or deprivation. Poverty and deprivation among unemployed households were above those for people in other labour force states throughout the period and while these differentials have narrowed, the findings suggest that trickle-down effects did not reach many of those highly disadvantaged or are subject to long delays. JEL Codes: I32, E65, H5

The crumbling pillar: Assessing the impact of housing costs on recent trends in poverty and deprivation in Australia

Homeownership has traditionally been high in Australia, where a broad range of tax and social security concessions are designed to promote ownership and reduce housing costs for owners. These have allowed homeowning age pensioners to avoid poverty despite receiving a pension that is low by international standards among high-income countries. This approach provides the fourth pillar of the Australian retirement income support system, an example of ‘Australian exceptionalism’. We examine recent trends in two measures of social disadvantage—poverty and deprivation—focusing on the changing role and impact of homeownership and housing costs. The comparisons reveal important differences in how housing costs are incorporated into the estimation of their impact and in how different social groups have fared, although our findings also indicate that the groups with highest incidence of poverty and deprivation have benefited least from the gains that others experienced over the period examined

Computer-aided: Modelled sustainable hybrid catalysts for a nano-drug delivery system

We evaluated a hybrid catalytic power source for less invasive internal electroporation with better tissue reach than the widely used and more invasive external electroporation.We modelled how open-circuit voltage optimizes platinum-loading in catalysts to improve the electrochemical activity (ECA) possible from bioelectrogenesis through these systems and address the high costs of nano-drug delivery systems. The effects of the catalysts’ convective flux and proton concentration were modelled for an enzyme (glucose oxidase) biofuel cell that was fed glucose substrate at a current rate under isothermal physiological conditions. Glucose concentrations were varied relative to anode catalyst loading models with 0.1–0.5 mg cm–2 platinum and alloyed (Pt-Ru-Ni) with a narrowparticle size distribution. Using the free (solvation) electron model, bioelectrochemical activity (BECA) and a high open circuit voltage were generated by 5.5, 10 and 20mMglucose with 20kUL–1 glucose oxidase at 37 °C.BECA(glucose oxidase), on its own, produced pulses of various intensities for nano–microsecond durations whereas the hybrid BECA-ECA (glucose oxidase and platinum) anode catalyst provided sustainable pulses of microseconds–minute durations. Enhanced catalysis with the hybrid BECA-ECA’s open circuit voltage favours compatibility of a hybrid-powered nano-drug delivery system for internal electroporation

Comparing the Monetary and Living Standards Approaches to Poverty Using the Australian Experience

This paper compares the monetary and living standards approaches to poverty using Australian data for the period 2006–2017. The aim is to highlight the conceptual and empirical strengths and weaknesses of the two approaches and identify the similarities and differences that emerge when both are applied to examine what happened over the period and to a limited degree, why. The acknowledged limitations of estimating poverty rates by comparing household income with a poverty line have to a degree been addressed by developments in deprivation research that have generated estimates that are more directly related to living standards, more democratic and more credible. But this approach also has limitations, so its growing popularity need not signify the end of poverty line studies. This paper compares the two approaches, with specific attention paid to ensuring that the estimates are internally consistent over time and comparable at a point in time. Both show a consistent pattern of modest improvement in social disadvantage over the period examined, but they reveal different aspects of change. The monetary approach highlights the role of housing costs in driving changes in poverty, while the more nuanced explanation generated by estimates of deprivation provides detailed insights. The results suggest that each has a positive role to play in better understanding the nature of poverty and identifying the factors driving change over time

South African Indians and HIV/AIDS: contextual factors in the experiences of HIV/AIDS in Chatsworth, KwaZulu-Natal.

Thesis (M.A.)-University of KwaZulu-Natal, Durban, 2010.This study set out to examine contextual level drivers of HIV among the South African Indian community of Chatsworth. Very little is currently known about HIV/AIDS among South African Indians. It was from this starting point that I set out to research this largely unexplored study topic, to gain insight into and understanding of the non-biological factors that underlie the spread of HIV/AIDS among people in Chatsworth. In-depth interviews, informal discussions and participant observation were carried out among community members, including members who were HIV positive. Findings revealed that poverty, gender power relations and stigma were major social factors contributing to the growth of HIV/AIDS within the South African Indian community of Chatsworth. Poverty places many in vulnerable positions, having to choose between treatment and disability grants to buy food for example, and gender inequalities make women more susceptible to contracting HIV than men. Culture plays a role in placing women in high risk situations. Furthermore stigma, denial and discrimination against people living with HIV/AIDS makes it very difficult for HIV positive people to disclose their status and to live their lives in the community. The importance of understanding the context in which the HIV/AIDS pandemic is occurring and the various cultural factors that play a role in the experience of HIV/AIDS in people?s lives, is argued to be vital to the development of successful strategies to prevent and manage the disease

Ultrastructure and cytochemistry of squamulae intravaginales of the marine angiosperm, Halophila ovalis

Small delicate structures found in the leaf bases in vegetative buds of the marine angiosperm Halophila ovalis (R. Br.) Hook. f. showed a fine structure of the component cells typical of secretory cells. They are rich in organelles particularly ER, dictyosomes, ribosomes and mitochondria. Endoplasmic reticulum occurs at two localities in each cell, one surrounding the central nucleus and the other in the peripheral regions close to the plasmalemma. Groups of dictyosomes occur between the two layers of ER and each group is separated from another by interconnecting strands of ER. A mucilaginous secretion accumulates on the cell surface and between the outer and inner layers of cell wall, particularly at the corners. The involvement of ER in the secretion of mucilage is discussed. Staining of ultrathin sections with silver proteinate after thiocarbohydrazide showed the presence of insoluble carbohydrates and histochemical tests with alcian dyes showed the secretion to contain non-sulphated acid polysaccarides. Staining of epoxy resin sections with Coomassie blue R250 indicated that the mucilage secretion on the surface of and within the cell walls also contained proteins. Cellulase–gold complex marked the cellulose wall layers as distinct from the included secretion

Incisional Hernia: Experience in a single surgical unit

Background: Incisional hernias are a common problem in general surgery and they have a varied aetiology. The aim of this study was to document a single unit experience with the management of incisional hernias at King Edward VIII Hospital, Durban, South Arica.Patients and Methods: This was a prospective audit of incisional hernias in a single surgical unit from January 2001 to May 2004. All patients underwent open repair. Clinical data and intra-operative findings were documented.Results: A total number of 77 patients were seen of which 70 were female. Fifty three (68.8%) and 24 (31.2%) of patients underwent elective and emergency surgery respectively. A total of 56 patients had previously undergone gynaecological surgery compared to 21 who had undergone general surgery. There was a documented history of previous sepsis in 4 (7%) of patients. There was 1 sheath defect in 36 patients, 2 defects in 9 patients, 3 defects in 10 patients, 4 or more defects in 9 cases. In 55 patients the original suture could not be identified. Gangrenous bowel was present in 3 patients. Only 3 (3.9%) of the patients had a mesh repair. The rest (96.1%) underwent tissue repair. Morbidity rate was 17% and there were no deaths. Five patients needed management in the ICU. Hospital stay was 8 + 11 yearsConclusion: Most incisional hernias followed gynaecological surgery. There was no evidence of a nonabsorbable suture having been used at the original operation in over half of the patients. We recommend that meticulous technique is essential in closing the abdominal incision