Exploring how fire spread mode shapes the composition of pyrogenic carbon from burning forest litter fuels in a combustion wind tunnel.

In this study, solid state 13C nuclear magnetic resonance (NMR) spectroscopy was used to explore the carbon-containing functional groups present in pyrogenic carbon (PyC) produced during different fire spread modes to forest litter fuels from a dry sclerophyll eucalypt forest burnt in a combustion wind tunnel. A replicated experimental study was performed using three different fire spread modes: heading fires (i.e. fires which spread with the wind), flanking fires (i.e. fires which spread perpendicular to the wind) and backing fires (i.e. fires which spread against the wind). In addition to 13C NMR measurements of PyC, detailed fire behaviour measurements were recorded during experiments. Experiments showed that heading fires produced significantly more aryl carbon in ash samples than flanking fires. All other experimental comparisons for burnt fuel samples involving different fire spread modes were statistically insignificant. Principal component analysis (PCA) was used to explore the relationship between 13C NMR functional groups and fire behaviour observations. Results from PCA indicate that maximising the residence time of high temperature combustion and the combustion factor (i.e. the fraction of pre-fire biomass consumed by fire) could be a method for increasing the amount of aryl carbon in PyC. Maximising the amount of aryl carbon could be beneficial for the overall PyC balance from fire, since more recalcitrant carbon (e.g. carbon with a higher aryl carbon content) that is not emitted to the atmosphere has been shown to have longer residence times in environmental media such as soils or sediments.

Incorrect interpretation of carbon mass balance biases global vegetation fire emission estimates.

Vegetation fires are a complex phenomenon in the Earth system with many global impacts, including influences on global climate. Estimating carbon emissions from vegetation fires relies on a carbon mass balance technique that has evolved with two different interpretations. Databases of global vegetation fire emissions use an approach based on 'consumed biomass', which is an approximation to the biogeochemically correct 'burnt carbon' approach. Here we show that applying the 'consumed biomass' approach to global emissions from vegetation fires leads to annual overestimates of carbon emitted to the atmosphere by 4.0% or 100 Tg compared with the 'burnt carbon' approach. The required correction is significant and represents ∼9% of the net global forest carbon sink estimated annually. Vegetation fire emission studies should use the 'burnt carbon' approach to quantify and understand the role of this burnt carbon, which is not emitted to the atmosphere, as a sink enriched in carbon.

Predictors of oral health after spinal cord injury.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: To examine predictors of oral health in people with spinal cord injury (SCI). METHODS: Ninety-two people with SCI (> or =6 months, 44% cervical level) completed questionnaires and underwent oral examination. Socio-economic, injury-related and oral habits variables were used for predicting oral health score (OHS); Decayed, missing and filled teeth (DMFT) score; and periodontal screen and recording index (PSR). RESULTS: Most people with SCI were able to bring at least one hand to the mouth (82%) and brush teeth independently (65%). Regarding daily oral habits, 84% reported brushing teeth, 48% rinsing mouth, 14% flossing, 33% tobacco use and 13% mouthstick use. Only 32% had teeth cleaned within the past year. Oral examination revealed three decayed and eight missing teeth on average, with prominent periodontal disease (64%). Employment before SCI and more risky oral habits were significant predictors of worse OHS (P=0.005 and P=0.014, respectively) and PSR score (P=0.010 and P=0.035, respectively). Older age was the only predictor of worse DMFT score (P<0.001). CONCLUSION: Oral health appears compromised in people with SCI. Identification of modifiable risk factors warrants examination whether intervention with focus on behavioral changes may improve oral health in this population.

Adrenal suppression in bronchiectasis and the impact of inhaled corticosteroids.

The present study identified three patients with bronchiectasis receiving inhaled corticosteroids (ICSs) who had symptomatic adrenal suppression secondary to ICS. The prevalence of adrenal suppression is unknown in bronchiectasis. The frequency of adrenal suppression and the impact of ICS use in bronchiectasis patients were examined. In total, 50 outpatients (33 receiving ICSs) underwent a short Synacthen test and completed a St George's Respiratory Questionnaire (SGRQ). Symptoms of adrenal suppression, steroid use and lung function were compared between subjects who were suppressed and those who were not. Adrenal suppression was evident in 23.5% of subjects who did not receive ICSs and 48.5% of those who did. Basal cortisol and the increments by which cortisol increased 30 min after Synacthen were lower in suppressed than in nonsuppressed subjects. The incremental cortisol rise was negatively correlated with SGRQ impacts and total score, suggesting a worse quality of life in those who had an impaired adrenal response. The greatest frequency of generalised symptoms was seen in the suppressed group. A significant proportion of subjects with bronchiectasis have evidence of adrenal suppression, and this is increased when inhaled corticosteroids are also used. Impairment of the cortisol response to stimulation is associated with poorer health status.

Suppression of false recognition in Alzheimer's disease and in patients with frontal lobe lesions.

Previous research has shown that patients with Alzheimer's disease show increasing levels of false recognition across five repeated study-test trials of semantic associates. The present study tested the hypotheses that (i) the increasing false recognition was partly due to the frontal lobe dysfunction of patients with Alzheimer's disease, and (ii) a failure of source monitoring was the central mechanism by which frontal lobe dysfunction led to increasing false recognition across trials. In Experiment 1, patients with frontal lobe lesions and controls were examined in the same repeated trials paradigm as that used previously in patients with Alzheimer's disease. Although controls were able to reduce their false recognition across trials, the patients with frontal lobe lesions were not, and instead showed a constant level of elevated false recognition across the study-test trials. In Experiment 2, two groups of patients with Alzheimer's disease and healthy older adult controls were studied: the first group was given a single study session followed by a recognition test, the second group was given five study sessions followed by a single recognition test. Older adults who were exposed to five study lists demonstrated lower levels of false relative to true recognition, whereas patients with Alzheimer's disease in this condition exhibited levels of false recognition elevated to that of their true recognition, even with the source memory confusion of intervening tests eliminated. The authors suggest that impairment in aspects of frontal lobe function, such as verification-inhibition mechanisms, probably contributes to the inability of patients with Alzheimer's disease to suppress their false recognition across repeated trials. Lastly, it is speculated that one way in which the frontal lobes enable normal episodic memory function is by facilitating the suppression of false recognition and other distortions of memory.

The family as a protective asset in adolescent development.

Adolescents are considered at high risk for engaging in such negative health behaviors as drug and alcohol use, unprotected sexual intercourse, and violence. Conventional wisdom has long upheld the belief that the peer group exerts the strongest influence on adolescent behavior. However, recent research has shown that in fact the family remains a strong factor in moderating teen risk behavior. Holistic nursing acknowledges the crucial relationship between environment and health; the environment is composed of everything that surrounds the individual, which by definition includes the family. The purpose of this article is to examine the evidence supporting the concept of the family as a protective external asset in adolescent development, to explore the way the family helps defend young people from risk, and to review briefly the implications for nursing research, practice, advocacy, and education.

Preventing injuries to infants of adolescent mothers.

Infant injury prevention is an important issue for practitioners who work with adolescent mothers. Data are presented to examine the association between having a young mother and being injured as an infant. Prevention messages need to take into account that parents in general tend to minimize the magnitude of injury risk to their children. With careful documentation, using External Cause of Injury Codes, practitioners may be able to estimate the cost savings of prevention initiatives.

Shortcomings in psychosocial history taking in a paediatric emergency department.

OBJECTIVE: To assess the quality of documentation of the psychosocial history taken from parents who repeatedly bring their infants and young children to an emergency department. METHODOLOGY: We prepared a list of 26 psychosocial items, indicated by the literature to be important elements of a history taken in this setting. We then reviewed subjects' casenotes, and compared each history to this ideal list. PARTICIPANTS/SETTING: Case note review of 104 children under 2 years who had presented to a paediatric emergency department at least five times in 1 year. RESULTS: Documentation of psychosocial history for these subjects was very poor, with a mean of only 5 of the 26 possible psychosocial items mentioned per set of casenotes. The majority of records lacked important information, including basic demographic data. CONCLUSIONS: We canvass possible reasons for poor psychosocial history taking, and argue for changes in medical education, the development of techniques to efficiently identify at risk children and families, and improved resources for referral.

Corneal donor infection by herpes simplex virus: herpes simplex virus DNA in donor corneas.

Three corneoscleral discs (from two donors) underwent subtotal endothelial loss during routine "long-term" organ culture storage. Laboratory studies of these corneas revealed evidence of herpes simplex virus (HSV) infection. The fellow cornea from one of the donors had been issued for transplant to a patient with keratoconus. Deterioration of the graft was noted 5 days after surgery; the disc was removed at 2 months and was shown to be infected with HSV. In an experiment designed to simulate initial "cleansing" of donor globes, 0.1% polyvinylpyrolidone-iodine protected cells from infection with HSV. It was concluded that the detection of HSV in these corneas could not be explained by external contamination of the ocular surface. Furthermore, culture of conjunctival and pharangeal swabs taken from 47 consecutive donors confirmed that HSV is rarely isolated at or around the time of death. Five pairs of donor corneas destined for use in transplantation were selected at random and investigated for the presence of HSV. HSV DNA was detected by polymerase chain reaction (PCR) in tissue from two of the corneal donors. Sequential stepwise sectioning suggested that HSV DNA when present was distributed in discrete foci within the cornea. These observations suggest that HSV infection may be a cause of severe endothelial loss during corneal organ culture and possibly provide an explanation for some "failures" of corneal grafting.

A randomized trial of a health care program for first-time adolescent mothers and their infants.

To test the effectiveness of a special health care program for adolescent mothers (17 years old or younger) and their infants, 243 mother-infant pairs were randomly assigned to one of two groups. All of the mothers were unwed, on Medicaid, and black. The control group received routine well-baby care. The experimental group received routine care and services that included rigorous follow-up, discussions with the mother about her plans for return to school and use of family planning methods, and extra health teaching. The dropout rate in the experimental group (60%) was significantly less after 18 months than the control group (82%). In spite of the high dropout rate, 91% of the mothers were located for the 18 month follow-up interview. The repeat pregnancy rate in the experimental group was 12% after 18 months, and 28% in the control group. There was no significant difference in the percentage returning to school. After 12 months, the infants in the experimental group were more likely to be fully immunized (33%) than the infants in the control group (18%). Mothers in the special care program who continued to attend clinic used the emergency room less than the mothers who continued to attend in the control group. These results suggest that a comprehensive health care program is one way to bring about better outcomes for both adolescent mothers and their infants.

PIP: 120 adolescent mothers who delivered at a large teaching hospital in Philadelphia, Pennsylvania, and their infants were assigned to an experimental group who had received special care which included rigorous follow-up, discussions with the mothers about plans to return to school and use of family planning, and additional health education. Another 123 mothers formed the control group and received only routine well-baby care. A nurse practitioner directed the experimental clinic. All the cases and controls were African American, on Medicaid, and unmarried. Mothers in the control group were more likely to return for all well-baby visits (at 2 weeks, 92% vs. 76%; at 18 months, 40% vs. 18%; p = 0.002). At 18 months, the dropout rate was high for both groups, but it was less for the experimental group than the control group (60% vs. 82%). Nevertheless, clinic staff were able to locate 91% of the mothers at 18 months postpartum. At 18 months, mothers in the experimental group had a lower repeat pregnancy rate than did those in the control group (12% vs. 28%; p = 0.003). More than 50% of mothers from both groups returned to school with no significant difference between the 2 groups. Children of mothers in the experimental group were more likely to be fully immunized at 18 months than those in the control group (33% vs. 18%; p 0.02). Experimental group mothers who still attended the clinic at 18 months were less likely to use the emergency room for infant care at least once than control group mothers who still attended the clinic (81% vs. 100%; p 0.03). These findings indicate that a comprehensive health care program improves outcomes for adolescent mothers and their infants. The high dropout rates from clinic attendance suggests a need for more research into developing programs targeting adolescent mothers.