Southern ocean carbon and heat impact on climate.

The Southern Ocean greatly contributes to the regulation of the global climate by controlling important heat and carbon exchanges between the atmosphere and the ocean. Rates of climate change on decadal timescales are therefore impacted by oceanic processes taking place in the Southern Ocean, yet too little is known about these processes. Limitations come both from the lack of observations in this extreme environment and its inherent sensitivity to intermittent processes at scales that are not well captured in current Earth system models. The Southern Ocean Carbon and Heat Impact on Climate programme was launched to address this knowledge gap, with the overall objective to understand and quantify variability of heat and carbon budgets in the Southern Ocean through an investigation of the key physical processes controlling exchanges between the atmosphere, ocean and sea ice using a combination of observational and modelling approaches. Here, we provide a brief overview of the programme, as well as a summary of some of the scientific progress achieved during its first half. Advances range from new evidence of the importance of specific processes in Southern Ocean ventilation rate (e.g. storm-induced turbulence, sea-ice meltwater fronts, wind-induced gyre circulation, dense shelf water formation and abyssal mixing) to refined descriptions of the physical changes currently ongoing in the Southern Ocean and of their link with global climate. This article is part of a discussion meeting issue 'Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities'.

Palliative sedation and moral distress: A qualitative study of nurses.

BACKGROUND: Clinical nursing practice may involve moral distress, which has been reported to occur frequently when nurses care for dying patients. Palliative sedation is a practice that is used to alleviate unbearable and refractory suffering in the last phase of life and has been linked to distress in nurses. AIM: The aim of this study was to explore nurses' reports on the practice of palliative sedation focusing on their experiences with pressure, dilemmas and morally distressing situations. METHODS: In-depth interviews with 36 nurses working in hospital, nursing home or primary care. RESULTS: Several nurses described situations in which they felt that administration of palliative sedation was in the patient's best interest, but where they were constrained from taking action. Nurses also reported on situations where they experienced pressure to be actively involved in the provision of palliative sedation, while they felt this was not in the patient's best interest. The latter situation related to (1) starting palliative sedation when the nurse felt not all options to relieve suffering had been explored yet; (2) family requesting an increase of the sedation level where the nurse felt that this may involve unjustified hastening of death; (3) a decision by the physician to start palliative sedation where the patient had previously expressed an explicit wish for euthanasia. CONCLUSIONS: Nurses experienced moral distress in situations where they were not able to act in what they believed is the patient's best interest. Situations involving moral distress require nurses to be well informed and able to adequately communicate with suffering patients, distressed family and physicians.

The extent to which healthy older adults rely on anticipatory control following simulated slip exposure.

As the recovery from gait perturbations is coordinatively complex and error-prone, people often adopt anticipatory strategies when the perturbation is expected. These anticipatory strategies act as a first line of defence against potential balance loss. Since age-related changes in the sensory and neuromotor systems could make the recovery from external perturbations more difficult, it is important to understand how older adults implement anticipatory strategies. Therefore, we exposed healthy young (N = 10, 22 ± 1.05 yrs.) and older adults (N = 10, 64.2 ± 6.07 yrs.) to simulated slips on a treadmill with consistent properties and assessed if the reliance on anticipatory control differed between groups. Results showed that for the unperturbed steps in between perturbations, step length decreased and the backward (BW) margin of stability (MOS) increased (i.e., enhanced dynamic stability against backward loss of balance) in the leg that triggered the slip, while step lengths increased and BW MOS decreased in the contralateral leg. This induced step length and BW MOS asymmetry was significantly larger for older adults. When exposed to a series of predictable slips, healthy older adults thus rely more heavily on anticipatory control to proactively accommodate the expected backward loss of balance.

Natural ageing primarily affects the initial response to a sustained walking perturbation but not the ability to adapt over time.

The ability to flexibly respond and adapt the walking pattern over time to unexpected gait perturbations is pivotal for safe and efficient locomotion. However, these abilities might be affected by age due to age-related changes in sensorimotor functioning. In this cross-sectional lifespan study, we used a split-belt paradigm to determine how age affects the initial response (i.e., flexibility)-and the ability to adapt after prolonged exposure-to a sustained gait perturbation. Healthy adults (N = 75) of different ages (12-13 per decade) were included and walked on a split-belt treadmill, in which a sustained gait perturbation was imposed by increasing one of the belt speeds. Linear regression models, with the evoked spatiotemporal gait asymmetry during the early perturbation and late adaptation, were performed to determine the effects of age on the flexibility and adaptability to split-belt walking. Results showed that the flexibility to respond to an unexpected perturbation decreased across the lifespan, as evidenced by a greater step length asymmetry (SLA) during the early perturbation phase. Despite this reduced flexibility in step lengths, late adaptation levels in SLA were comparable across different ages. With increasing age, however, subjects needed more steps to reach a stable level in SLA. Finally, when the belts were set to symmetrical speeds again, the magnitude of SLA (i.e., the aftereffects) increased with age. Collectively, these findings suggest that natural ageing comes with a decrease in gait flexibility, while the ability to adapt to split-belt walking was not affected by age-only how adaptation was achieved.

[Practicing medicine at the end of life: use clear language]. / Dokteren aan het levenseinde: gebruik heldere taal.

Up to thirty years ago, in the Netherlands the word 'stervensbegeleiding' [literally, dying-guidance] was used to refer to care for people in the last days of life. After Cicely Saunders had developed a multidisciplinary and multidimensional approach for care for the dying, the wording changed, until the word 'palliative care' was adopted. This care gradually developed from care for the dying to care for all people with life-threatening illness, as illustrated in the WHO definition. This shift in focus of care raises the question of when palliative care starts. The surprise question is regarded as a useful tool for marking this shift in focus of care. However, answering the surprise question does not inform us about palliative care needs. Nevertheless, when people enter the dying phase, a fundamental change in the nature of care is needed. The word 'stervensbegeleiding' marks this change of care.

[Palliative sedation, the sympathetic alternative for euthanasia?]. / Palliatieve sedatie, het sympathieke alternatiefvoor euthanasie?

Palliative sedation is given to relieve refractory discomfort (pain, shortness of breath, agitation) during the phase when life expectancy is estimated to be a week or less. It is a medical intervention which, although not expressly meant to shorten life, may well do so. There is an inherent uncertainty here which is the cause of considerable ethical unease. Figures show that in a limited number of cases palliative sedation is actually applied with the intention to hasten death. It may well be impossible to rid ourselves ofthis uncertainty conclusively.

Alpha 2-adrenoceptor coupling to adenylate cyclase in adrenaline insensitive human platelets.

Coupling of the alpha 2-adrenoceptor to adenylate cyclase was assessed in platelets from 3 groups of subjects: normal controls and patients with myeloproliferative disorders whose platelets were either sensitive or specifically insensitive to the aggregatory effects of adrenaline. The ability of adrenaline to induce the formation of a complex between the alpha 2-adrenoceptor and the inhibitory guanine nucleotide binding protein was examined in all three groups by assessment of the effect of mono and divalent cations and Gpp(NH)p on the displacement of [3H]yohimbine binding to platelet membranes by adrenaline. Coupling to adenylate cyclase was also assessed in separate studies of the inhibition by adrenaline of PGE1 stimulated cyclic AMP accumulation in whole platelets. Both the formation of the ternary complex and the inhibition by adrenaline of cyclic AMP accumulation was not significantly different in platelets sensitive or insensitive to adrenaline. These results suggest that inhibition of cyclic AMP alone does not explain the mechanisms of adrenaline induced platelet aggregation.

Human platelet alpha 2-adrenoceptors: relationship between radioligand binding studies and adrenaline-induced aggregation in normal individuals.

Using the alpha 2-adrenoceptor selective radioligand [3H]yohimbine maximum binding capacities (Bmax), dissociation constants (KD), and the affinity (KI) of adrenaline for the binding sites were measured in platelets obtained from a group of 42 normal individuals. These results were compared with the efficacy of adrenaline induced aggregation in platelet rich plasma in the same subjects. Wide interindividual variation was found in Bmax values as measured in whole platelets (sites/platelet) or platelet lysates (fmol/mg protein) and in KI values for adrenaline displacement of [3H]yohimbine binding. Adrenaline's ability to induce platelet aggregation measured as the concentration required to achieve half maximal aggregation assessed from dose-response curves showed similar interindividual variation. No correlation was found, however, between alpha 2-adrenoceptor status as assessed by radioligand binding studies and the functional studies. These results suggest that the present understanding of the relationship between alpha 2-adrenoceptor occupation and platelet aggregation may be incorrect.

Functional significance of the platelet alpha2-adrenoceptor: studies in patients with myeloproliferative disorders.

Platelet alpha-adrenoceptor status was examined in 35 patients with myeloproliferative disorders (MPD) and 35 normal controls by means of radioligand binding studies with 3H-yohimbine (3H-YOH) and in vitro platelet function tests. A group of 'adrenaline insensitive' MPD patients identified in the functional studies were found to be identical to normal controls and other MPD patients with respect to their alpha 2-adrenoceptor status as assessed by the binding studies. Possible explanations for the dissociation between radioligand binding studies and functional responses in the platelet are discussed.

Differential labeling of platelet alpha 2 adrenoceptors by 3H dihydroergocryptine and 3H yohimbine in patients with myeloproliferative disorders.

Platelet alpha adrenoceptor status was examined using the radioligands 3H-yohimbine (3H-YOH) and 3H-dihydroergocryptine (3H-DHE) in 14 patients with myeloproliferative disorder (MPD) and 10 normal controls. Platelets from normal controls and MPD patients sensitive to adrenaline induced aggregation exhibited approximately 50% more binding sites identified by 3H-DHE than 3H-YOH, whereas MPD platelets insensitive to adrenaline showed selective loss of these 'extra' 3H-DHE sites. In functional studies after 30 minutes preincubation with the unlabelled antagonists, DHE was more potent than YOH at inhibiting adrenaline induced aggregation in normal platelets. In addition, the affinity constant for DHE was virtually identical in binding and functional experiments, whereas for YOH the affinity constant for binding was approximately 10 fold more potent than that for aggregation. These results suggest that the alpha adrenoceptor binding site on human platelets labelled by 3H-DHE may be of more functional relevance than that labelled by 3H-YOH alone.

Effects of adrenaline and alpha adrenergic antagonists on platelet aggregation in whole blood: evaluation of electrical impedance aggregometry.

The effects of adrenaline and alpha adrenergic antagonists on platelet aggregation in whole blood were assessed by electrical impedance. These effects were then compared to those found in platelet rich plasma assessed by both optical and impedance methods. Our data demonstrate a number of difficulties in attempting to measure platelet responsiveness by electrical impedance and re-emphasise the need for caution in interpretation of in vitro platelet aggregation studies in terms of their clinical relevance.

Nasal secretions from patients with polyps and healthy individuals, collected with a new aspiration system: evaluation of total protein and immunoglobulin concentrations.

This study was designed, first, to test a new system for aspiration of human nasal secretions and, secondly, to evaluate protein and immunoglobulin concentrations in these secretions at different levels of secretory activity. The direct aspiration system combines the advantages of minimal irritation of the nasal mucosa with the facility to determine concentrations per gram of secretion. The total protein and immunoglobulin concentrations were inversely related to the amount of secretion obtained. Variations in fluid secretion throughout the day may be responsible for this relationship. The inverse relationship was much more significant in patients with nasal polyps, in which much higher concentrations were found, than in healthy subjects. Ratios of immunoglobulin to total protein were independent of the amount of secretion obtained. Compared to the controls, the ratios of IgM and IgG to protein in the secretions of the patients were significantly increased. The secretory immunoglobulin A to total protein ratios were only slightly higher in the patients' secretions.

Microbial, chemical and physical aspects of citrus waste composting.

Citrus waste supplemented with calcium hydroxide and with a C/N ratio of 24:1, pH of 6.3 and moisture content of 60% was composted by piling under shelter. With regular turning over of the pile and replenishment of moisture, the thermic phase lasted for 65-70 days and composting was completed after 3 months. Compost thus prepared had an air-filled porosity of 14%, water-holding capacity of 590 ml l(-1), bulk density of 1.05 g cm(-3) and conductivity of 480 mS m(-1). Phosphorus content (in mg l(-1)) was 15, potassium 1,170, calcium 362, magnesium 121, sodium 32, chloride 143, boron 0.31, and water-soluble nitrogen and organic matter 126 and 4788, respectively. Total carbon amounted to 8.85% and total nitrogen to 1.26% of the dry weight, giving a C/N ratio of 7. Mature compost showed some, but acceptable, levels of phytotoxicity. Raw citrus waste was predominantly colonised by mesophilic yeasts. Thermophilous microorganisms present during the thermic phase mainly comprised the bacterial species Bacillus licheniformis, B. macerans and B. stearothermophilus and, to a lesser extent, fungi such as Absidia corymbifera, Aspergillus fumigatus, Emericella nidulans, Penicillium diversum, Paecilomyces variotii, Rhizomucor pusillus, Talaromyces thermophilus and Thermomyces lanuginosus. Bacteria prevalent in the final product included B. licheniformis, B. macerans, Proteus vulgaris, Pseudomonas aeruginosa, P. fluorescens, P. luteola and Serratia marcescens, whereas fungi isolated most frequently comprised Aspergillus puniceus, A. ustus, E. nidulans. Paecilomyces lilacinus, T lanuginosus, yeasts and a basidiomycetous species, probably Coprinus lagopus.

Childhood hearing loss in sub-Saharan Africa: a review and recommendations.

Nearly 10% of the world's population lives in sub-Saharan Africa, a region comprised of many countries with least developed nation status. The region has a predominantly young population and many children in the region are at risk of pathologies associated with hearing loss. Despite the constraints associated with low socioeconomic levels, a number of valuable studies have been carried out into the prevalence and etiology of childhood hearing loss in the sub-Saharan region. A review of the published literature related to childhood hearing loss in sub-Saharan Africa is presented and recommendations made on possible future research directions that could assist hearing loss prevention and management.

A survey of ear and hearing disorders amongst a representative sample of grade 1 schoolchildren in Swaziland.

A representative sample of Grade 1 (first year school entry) schoolchildren in Swaziland were surveyed during a single week to determine the prevalence of ear and hearing disorders: 79.8% had both normal ears and normal hearing, 16.8% had an ear disorder, but 80% of them had normal hearing. The most common disorder was impacted wax, with a prevalence rate of 74/1000. Middle ear disorders were common and the prevalence rate for children with active middle ear disease was 30/1000 (17/1000 having a hearing loss), and for children with inactive ear disease, the prevalence was 21/1000 (5/1000 having a hearing loss); 8/1000 children were found to have a sensorineural hearing loss, 5.3/1000 unilateral and 2.1/1000 bilateral. Improved treatment of acute otitis media, which is also common in the pre-school age group, could reduce the sequelae of the disorder, which has a deleterious effect on hearing and impairs educational achievement once the children enrol at school.

Therapists' perceptions of pediatric occupational therapy interventions in self-care.

OBJECTIVES: This study examined the congruence between pediatric occupational therapists' self-care interventions and occupational therapy's philosophical base, which focuses on performance of self-care skills as primary in evaluation and intervention. METHOD: A questionnaire was mailed to 252 therapists serving children ages birth to 6 years. The questionnaire asked for therapists' perceptions about the importance, uniqueness, and frequency of 10 areas of intervention, including self-care. RESULTS: Perceived importance of self-care was found to be strongly related to perceived frequency of self-care intervention. Practice setting was significantly associated with perceptions of uniqueness of self-care, and team membership status was significantly associated with importance of self-care. Most respondents perceived self-care intervention to be important (86%) and unique (80%) to occupational therapy. Seventy percent regularly provided intervention for self-care. CONCLUSIONS: The therapists' perceptions reflected continued regard for self-care as an important and unique area of pediatric occupational therapy but were somewhat discrepant with the actual frequency of self-care interventions.

A comparison of flight of colours with visually evoked responses in patients with multiple sclerosis.

The flight of colours test was performed in a series of patients with multiple sclerosis. Visually evoked responses were then measured in the same patients. The two tests were found to be comparable in their ability to detect disturbance in the visual system.