Ending the affair: The decline of television current affairs in Australia

Examines the state of current affairs television in Australia today by pondering the future, while drawing lessons from the past. The book questions the social and political value of what we now think of as current affairs journalism.

Characterization of calcium-activated chloride channels in patches excised from the dendritic knob of mammalian olfactory receptor neurons

We investigated the properties of calcium-activated chloride channels in inside-out membrane patches from the dendritic knobs of acutely dissociated rat olfactory receptor neurons. Patches typically contained large calcium-activated currents, with total conductances in the range 30-75 nS. The dose response curve for calcium exhibited an EC50 of about 26 mu M. In symmetrical NaCl solutions, the current-voltage relationship reversed at 0 mV and was linear between -80 and +70 mV. When the intracellular NaCl concentration was progressively reduced from 150 to 25 mM, the reversal potential changed in a manner consistent with a chloride-selective conductance. Indeed, modeling these data with the Goldman-Hodgkin-Katz equation revealed a P-Na/P-Cl of 0.034. The halide permeability sequence was P-Cl > P-F > P-I > P-Br indicating that permeation through the channel was dominated by ion binding sites with a high field strength. The channels were also permeable to the large organic anions, SCN-, acetate(-), and gluconate(-), with the permeability sequence P-Cl > P-SCN > gluconaie. Significant permeation to gluconate ions suggested that the channel pore had a minimum diameter of at least 5.8 Angstrom.

Potential errors in the application of mixture theory to multifrequency bioelectrical impedance analysis

Potential errors in the application of mixture theory to the analysis of multiple-frequency bioelectrical impedance data for the determination of body fluid volumes are assessed. Potential sources of error include: conductive length; tissue fluid resistivity; body density; weight and technical errors of measurement. Inclusion of inaccurate estimates of body density and weight introduce errors of typically < +/-3% but incorrect assumptions regarding conductive length or fluid resistivities may each incur errors of up to 20%.

Synthesis of hydroperoxide and perketal derivatives of polyunsaturated fatty acids as potential antimalarial agents

Hydroperoxide derivatives of beta-oxa-substituted polyunsaturated fatty acids were prepared by 15-lipoxygenase catalysed oxidation and perketal derivatives of fatty acid hydroperoxides were synthesized. The perketals are more stable than their parent fatty acid hydroperoxides, but less active as antimalarial agents in the in vitro growth inhibition of Plasmodium falciparum. (C) 1998 Elsevier Science Ltd. All rights reserved.

Calculating current densities and fields due to shielded bi-planar radio-frequency coils

A method for the accurate computation of the current densities produced in a wide-runged bi-planar radio-frequency coil is presented. The device has applications in magnetic resonance imaging. There is a set of opposing primary rungs, symmetrically placed on parallel planes and a similar arrangement of rungs on two parallel planes surrounding the primary serves as a shield. Current densities induced in these primary and shielding rungs are calculated to a high degree of accuracy using an integral-equation approach, combined with the inverse finite Hilbert transform. Once these densities are known, accurate electrical and magnetic fields are then computed without difficulty. Some test results are shown. The method is so rapid that it can be incorporated into optimization software. Some preliminary fields produced from optimized coils are presented.

Presynaptic long-term depression at a central glutamatergic synapse: a role for CaMKII

CaMKII is a calcium-activated kinase that is abundant in neurons and has been strongly implicated in memory and learning. Here we show that low-frequency stimulation of glutamatergic afferents in hippocampal slices from juvenile domestic chicks results in long-term depression of synaptic transmission. This reduction does not require activation of NMDA or metabotropic glutamate receptors and does not require a rise in postsynaptic calcium. However, buffering presynaptic calcium prevents the reduction of the excitatory postsynaptic potential or current that is induced by low-frequency stimulation. in addition, application of the calmodulin antagonist calmidazolium, or the specific CaMKII antagonist KN-93, completely blocks long-term depression. These findings demonstrate a newsy discovered form of long-term synaptic depression in the avian hippocampus.

Focused antithrombotic therapy: Novel anti-platelet salicylates with reduced ulcerogenic potential and higher first-pass detoxification than aspirin in rats

The use of aspirin as an anti-platelet drug is limited by its propensity to induce gastric injury and by its adverse effect on vascular prostacyclin formation. Two phenolic non-steroidal anti-inflammatory drugs (salicyclic acid and diflunisal) were modified by esterification with a series of O-acyl moieties. The short-term ulcerogenic in vitro and in vivo anti-platelet properties, pharmacodynamic profiles, and extent of hepatic extraction of these phenolic esters were compared with aspirin (acetylsalicylic acid). The more lipophilic esters (longer carbon chain length in O-acyl group) show significantly less gastrotoxicity in stressed rats than does aspirin after a single oral dose. The in vitro and in vivo anti-platelet studies show that these phenolic esters inhibited (1) arachidonate-triggered human platelet aggregation and (2) thrombin-stimulated rat serum thromboxane Ag production by platelets in the clotting process almost as effectively as aspirin. The hepatic extractions of these O-acyl derivatives are significantly higher than those of aspirin. The pharmacodynamic studies show that these O-acyl derivatives of salicylic acid and diflunisal probably bind to, or combine with, the same site on the platelet cyclooxygenase as aspirin. Replacing the O-acetyl group with longer chain O-acyl moiety in this series of phenolic esters markedly reduced the potential of these agents to induce short-term gastric injury but did not lessen their activity as inhibitors of platelet aggregation. These non-acetyl salicylates may therefore represent a novel class of anti-platelet drugs with less ulcerogenic potential.

Tongue piercing: Case report and review of current practice

Although oral piercing has been an uncommon practice in the Western world, the insertion of metal objects into intra-oral and peri-oral pierced sites is growing in popularity. Tongue piercing is one such practice whereby a metal barbell is inserted into the tongue after piercing with a 14-16 gauge needle. Pain, swelling and infection are the most serious consequences associated with this procedure. Other adverse outcomes include mucosal or gingival trauma, chipped or fractured teeth, increased salivary flow, calculus build-up, and interference with speech, mastication and swallowing. This article presents a case report on tongue piercing and highlights the procedure involved. Special attention is given to complications and dental implications associated with such an unusual practice.

STD syndrome packets: Improving syndromic management of sexually transmitted diseases in developing countries

Objective: To design, introduce, and evaluate STD syndrome packets containing recommended drugs for each syndrome, four condoms, a partner treatment card, and a patient information leaflet, with the goal of improving sexually transmitted disease (STD) case management. Methods: Packet design evolved around available packaging technology, informed by pilot testing with nurses working in primary care clinics, doctors in private medical practices, and patients with an STD, in Hlabisa, South Africa. Evaluation 1 year later included analysis of distribution records and interviews with 16 nurses and 61 patients. Results: A cheap packet (2 U, S, cents each, excluding contents) compatible with current legislation was designed and introduced to six public sector clinics and as a short pilot to five private medical practices, Four thousand eighty-five packets were distributed to the clinics, equivalent to approximately 115% of the STDs reported over that period. All 16 nurses reported using the packets, but only 63% did so all the time because of occasional supply problems, All believed the packets improved treatment by saving time (75%), improving supply of condoms and partner cards (44%), and making treatment easier (56%), Patients also responded positively, and most said they would buy a packet (up to $5) at a pharmacy (84%) or store (63%) if available. Conclusions: The STD syndrome packets have the potential to improve STD syndromic management by standardizing therapy and improving the supply of condoms, partner cards, and information leaflets. Packets are popular with practitioners and patients, but consistent supply is essential for maximal impact, There may be scope for social marketing of the packets, which could further increase use.

Quantum open-systems approach to current noise in resonant tunneling junctions

A quantum Markovian master equation is derived to describe the current noise in resonant tunneling devices. This equation includes both incoherent and coherent quantum tunneling processes. We show how to obtain the population master equation by adiabatic elimination of quantum coherences in the presence of elastic scattering. We calculate the noise spectrum for a double well device and predict subshot noise statistics for strong tunneling between the wells. The method is an alternative to Green's function methods and population master equations for very small coherently coupled quantum dots.

Potential strategies utilised by papillomavirus to evade host immunity

The co-evolution of papillomaviruses (PV) and their mammalian hosts has produced mechanisms by which PV might avoid specific and non-specific host immune responses. Low level expression of PV proteins in infected basal epithelial cells, together with an absence of inflammation and of virus-induced cell lysis, restricts the opportunity for effective PV protein presentation to immunocytes by dendritic cells. Additionally, PV early proteins, by a range of mechanisms, may restrict the efficacy of antigen presentation by these cells. Should an immune response be induced to PV antigens, resting keratinocytes (KC) appear resistant to interferon-gamma-enhanced mechanisms of cytotoxic T-lymphocyte (CTL)-mediated lysis, and expression of PV antigens by resting KC can tolerise PV-specific CTL. Thus, KC, in the absence of inflammation, may represent an immunologically privileged site for PV infection. Together, these mechanisms play a parr in allowing persistence of PV-induced proliferative skin lesions for months to years, even in immunocompetent hosts.

Accuracy of predicting a child's response to potential threat: A comparison of children and their mothers

Considerable research has indicated that children and their parents often demonstrate marked discrepancies in their reporting of anxiety-related phenomena. In such cases, the question arises as to whether children are capable of accurately reporting on their anxiety. In the present study, 50 children (aged 5 to 14 years) were asked to approach a large, German Shepherd dog. Prior to the task, both the mother and child independently predicted the closest point likely to be reached by the child and the degree of anxiety likely to be experienced. These predictions were then compared with the actual phenomena displayed by the child during the task. On the behavioural measure (closest step reached), both the child and mother demonstrated equivalent predictive accuracy. On the subjective measure (fear ratings) children were considerably more accurate than their mothers. The data were not influenced by gender, age, or clinical status. The results indicate the ability of children to accurately predict their anxious responses, and support the value of incorporating children's self-reports in the assessment of emotional disorders.

Traditional healers as tuberculosis treatment supervisors: precedent and potential

SETTING: Hlabisa, South Africa. OBJECTIVE: To determine precedent and potential for traditional healers to act as tuberculosis (TB) treatment supervisors. METHODS: Literature review to describe precedent for the involvement of traditional healers in TB treatment supervision. Interviews with 100 TB patients to determine use of healers and their acceptability as supervisors. Interviews with 24 healers in the project sub-district to determine willingness to act as supervisors. RESULTS: Despite extensive literature on the interaction between traditional healers and conventional health services, including descriptions of traditional understandings of TB, no published work was identified that reported supervision of TB patients by traditional healers. Of 100 patients interviewed, only 10% had used a healer as the first health provider for their illness, but 40% had attended a healer at some time prior to diagnosis. Although only 4% believe healers can cure TB, 84% would consider choosing a healer as a treatment supervisor. Of the 24 healers, 15 (63%) distinguished between two types of diagnosis made among patients with. symptoms suggestive of TB: TB and idliso. Idliso is poisoning or bewitching, and is said to be best cured by healers, while TB is infectious and cannot be cured by healers. Most healers (88%) reported having referred patients with possible TB to hospital in the past; all were keen to negotiate collaboration with health services, and 92% were willing to act as treatment supervisors. CONCLUSIONS: While there is little reported precedent for traditional healers to interact formally with tuberculosis treatment services, the potential for collaboration seems to be high, at least in our setting.

GABA receptors inhibited by benzodiazepines mediate fast inhibitory transmission in the central amygdala

The amygdala is intimately involved in emotional behavior, and its role in the generation of anxiety and conditioned fear is well known. Benzodiazepines, which are commonly used for the relief of anxiety, are thought to act by enhancing the action of the inhibitory transmitter GABA. We have examined the properties of GABA-mediated inhibition in the amygdala. Whole-cell recordings were made from neurons in the lateral division of the central amygdala. Application of GABA evoked a current that reversed at the chloride equilibrium potential. Application of the GABA antagonists bicuculline or SR95531 inhibited the GABA-evoked current in a manner consistent with two binding sites. Stimulation of afferents to neurons in the central amygdala evoked an IPSC that was mediated by the release of GABA. The GABA(A) receptor antagonists bicuculline and picrotoxin failed to completely block the IPSC. The bicuculline-resistant IPSC was chloride-selective and was unaffected by GABA(B)-receptor antagonists. Furthermore, this current was insensitive to modulation by general anesthetics or barbiturates. In contrast to their actions at GABA(A) receptors, diazepam and flurazepam inhibited the bicuculline-resistant IPSC in a concentration-dependent manner. These effects were fully antagonized by the benzodiazepine site antagonist Ro15-1788. We conclude that a new type of ionotropic GABA receptor mediates fast inhibitory transmission in the central amygdala. This receptor may be a potential target for the development of new therapeutic strategies for anxiety disorders.