Extremely Large Variations of Atmospheric 14C Concentration During the Last Glacial Period

A long record of atmospheric 14C concentration, from 45 to 11 thousand years ago (ka), was obtained from a stalagmite with thermal-ionization mass-spectrometric 230Th and accelerator mass-spectrometric 14C measurements. This record reveals highly elevated Delta14C between 45 and 33 ka, portions of which may correlate with peaks in cosmogenic 36Cl and 10Be isotopes observed in polar ice cores. Superimposed on this broad peak of Delta14C are several rapid excursions, the largest of which occurs between 44.3 and 43.3 ka. Between 26 and 11 ka, atmospheric Delta14C decreased from approximately 700 to approximately 100 per mil, modulated by numerous minor excursions. Carbon cycle models suggest that the major features of this record cannot be produced with solar or terrestrial magnetic field modulation alone but also require substantial fluctuations in the carbon cycle.

Decreased brain metabolism in neurologically intact healthy alcoholics

OBJECTIVE

The extent to which cerebral dysfunction in alcoholics is related to the direct effects of alcohol in the brain rather than to indirect mechanisms and/or alcohol withdrawal remains unclear. The purpose of this study was to evaluate whether healthy alcoholics with no evidence of alcohol-associated complications showed changes in brain glucose metabolism.

METHOD

Positron emission tomography and [18F]-fluorodeoxyglucose were used to measure regional brain metabolism. The study group consisted of 22 normal, healthy, right-handed volunteers and 22 neurologically intact, healthy, right-handed alcoholics tested 6 to 32 days after alcohol discontinuation.

RESULTS

Alcoholics showed significantly lower whole brain metabolism than normal control subjects. Normalization of regional metabolic values to the whole brain metabolic rate revealed that the left parietal and right frontal cortices were the most affected regions. Although the whole brain metabolic rate was correlated with the amount of time since alcohol discontinuation, the "normalized" decreases in left parietal and right frontal glucose metabolism were not.

CONCLUSIONS

These findings support the contribution of the direct effect of alcohol as well as alcohol withdrawal on the changes in regional brain metabolism seen in alcoholics. They also provide evidence of cerebral changes in neurologically intact healthy alcoholics.

Acute effects of ethanol on regional brain glucose metabolism and transport

To evaluate the effects of ethanol in the human brain, we tested six normal subjects and six alcoholics using positron emission tomography and 2-deoxy-2-[18F]-fluoro-D-glucose (FDG) under baseline conditions and 24 hours later after ethanol administration (1 g/kg). Ethanol inhibited cortical and cerebellar glucose metabolism with relative sparing of the basal ganglia and corpus callosum. This inhibition was more pronounced in the alcoholics than in the controls. Measurement of the constants for glucose transport and utilization showed that decreased glucose metabolism was due to a reduction in glucose phosphorylation and not to a change of glucose transport into the tissue. The pattern of regional metabolic inhibition by alcohol paralleled the distribution of benzodiazepine receptors in the human brain.

Recovery of brain glucose metabolism in detoxified alcoholics

OBJECTIVE

To differentiate withdrawal-related abnormalities in brain glucose metabolism among alcoholics from abnormalities that may be irreversible or antedate alcohol use, the authors evaluated metabolic recovery during alcohol detoxification.

METHOD

Regional brain glucose metabolism was measured with positron emission tomography and 2-deoxy-2-[18F]fluoro-D-glucose in 10 male alcoholics at 8-15 days, 16-30 days, and 31-60 days after last use of alcohol. The alcoholics' metabolic values were compared with those of 10 age-matched male healthy volunteers.

RESULTS

Brain metabolism increased significantly during detoxification. There were significant differences in global and regional measures between the first and last time points but not between the second and third points, suggesting that recovery occurred predominantly within 16-30 days. Regional increases in metabolism were greater in the frontal regions. Whereas during the first evaluation the alcoholics showed significantly lower metabolism in various brain regions than the comparison group, at the end of detoxification the alcoholics showed significantly lower absolute and relative metabolic values in the basal ganglia and lower relative metabolic values in the parietal cortex. Among the alcoholics, but not the comparison group, metabolism in the frontal, parietal, and left temporal cortexes was negatively correlated with years of alcohol use and with age.

CONCLUSIONS

This study shows significant increases in brain metabolism during alcohol withdrawal and documents persistent low metabolic levels in the basal ganglia of detoxified alcoholics.

Contextualizing critical care family needs through triangulation: an Australian study

Family needs and concerns within the critical care context have been thoroughly explored from the quantitative perspective utilizing the Critical Care Family Needs Inventory (CCFNI). Nursing interventions have been designed on the basis of the findings from these studies. However, while the CCFNI would seem to encompass all the possible needs of families with a critically ill loved one, at no time were the family members themselves consulted at length in regard to the development of the instrument, or in any subsequent validation studies. Individual reality generates the variables that are measured in a needs analysis, and the family member experiences encompass dimensions that are not easily assessed by quantification. In fact the unique experiences of family members underpin their perception of need. Methodological triangulation formed the basis for this study to determine the degree of confirmation (or otherwise) between family member respondents to the CCFNI (n = 105) and those participating in an interview (n = 26) designed to explore needs and experiences. The qualitative data served the purpose of completeness by providing a more contextual representation of needs and therefore greater depth of understanding of the whole construct. The results indicate that, while there were many areas of convergence between the two samples, there were also areas of diveregence. Two major needs emerged from the interviews that are not represented on the CCFNI: the need of family members to provide reassurance and support to the patient; and their need to protect (others as well as the patient). A more complete understanding of family needs was obtained through the contextualization of their experiences.

A Large Drop in Atmospheric 14C/12C and Reduced Melting in the Younger Dryas, Documented with 230Th Ages of Corals

Paired carbon-14 ((14)C) and thorium-230((230)Th) ages were determined on fossil corals from the Huon Peninsula, Papua New Guinea. The ages were used to calibrate part of the (14)C time scale and to estimate rates of sea-level rise during the last deglaciation. An abrupt offset between the (14)C and (230)Th ages suggests that the atmospheric (14)C/(12)C ratio dropped by 15 percent during the latter part of and after the Younger Dryas (YD). This prominent drop coincides with greatly reduced rates of sea-level rise. Reduction of melting because of cooler conditions during the YD may have caused an increase in the rate of ocean ventilation, which caused the atmospheric (14)C/(12)C ratio to fall. The record of sea-level rise also shows that globally averaged rates of melting were relatively high at the beginning of the YD. Thus, these measurements satisfy one of the conditions required by the hypothesis that the diversion of meltwater from the Mississippi to the St. Lawrence River triggered the YD event.

Regional brain metabolic response to lorazepam in subjects at risk for alcoholism

The mechanisms underlying the blunted response to alcohol administration observed in subjects at risk for alcoholism are poorly understood and may involve GABA-benzodiazepine receptors. The purpose of this study was to investigate if subjects at risk for alcoholism had abnormalities in brain GABA-benzodiazepine receptor function. This study measured the effects of 30 micrograms/kg (i.v.) of lorazepam, on regional brain glucose metabolism using positron emission tomography and 2-deoxy-2[18F]fluoro-D-glucose in subjects with a positive family history for alcoholism (FP) (n = 12) and compared their response with that of subjects with a negative family history for alcoholism (FN) (n = 21). At baseline, FP subjects showed lower cerebellar metabolism than FN. Lorazepam decreased whole-brain glucose metabolism, and FP subjects showed a similar response to FN in cortical and subcortical regions, but FP showed a blunted response in cerebellum. Lorazepam-induced changes in cerebellar metabolism correlated with its motor effects. The decreased cerebellar baseline metabolism in FP as well as the blunted cerebellar response to lorazepam challenge may reflect disrupted activity of benzodiazepine-GABA receptors in cerebellum. These changes could account for the decreased sensitivity to the motor effects of alcohol and benzodiazepines in FP subjects.

Depression of thalamic metabolism by lorazepam is associated with sleepiness

Though it is well recognized that the pharmacological actions of benzodiazepines are mediated by facilitation of GABAergic neurotransmission, the consequences of these changes in regional brain function are not well understood. This study measured regional brain glucose metabolism using Positron Emission Tomography and 2-deoxy-2[18F]fluoro-D-glucose in normal controls (n = 21) investigated with and without lorazepam (30 micrograms/kg IV) and with flumazenil given after lorazepam (n = 9). Lorazepam markedly decreased metabolism in thalamus (23 +/- 8%) and occipital cortex (19 +/- 8%), and flumazenil partially reversed these changes. Changes in metabolic activity in thalamus were significantly correlated with lorazepam-induced sleepiness (r = .69, df 20, p < .0005) and there was a trend of an association between the reversal by flumazenil of lorazepam-induced change in thalamus and in sleepiness (r = .63, df 8, p = .07). Benzodiazepine-induced changes in thalamic activity may account for their sedative properties.

Lead poisoning among household members exposed to lead-acid battery repair shops in Kingston, Jamaica

To investigate the risk of lead poisoning among household members exposed to 'backyard' battery repair shops (BBRS) in Kingston, Jamaica, environmental and blood lead (PbB) were measured at 24 households (112 individuals) with a BBRS worker or located at a BBRS premises and at 18 neighbourhood control households (74 individuals). Elevated PbB (greater than or equal to 25 micrograms per decilitre [micrograms/dl]) was common among subjects of all ages living at BBRS premises, especially among children less than age 12, 43% of whom had PbB greater than 70 micrograms/dl. Potentially hazardous soil and house dust lead levels were also common at BBRS premises, where 84% of yards had soil lead levels above 500 parts per million (geometric mean 3388 parts per million [ppm] at BBRS premises households with a BBRS worker). Geometric mean blood and environmental lead levels were significantly lower at control households, where less than 10% of subjects in all age groups had elevated PbB (maximum 33 micrograms/dl). Sharing a premises with a BBRS was a stronger determinant of household blood lead and environmental contamination than was the presence of a BBRS worker in a household. Blood lead levels were associated with soil and house dust lead levels in all age groups. We conclude that small battery repair shops, which have also been described in other developing countries, create a high lead poisoning risk for nearby residents.

Current triage practice and influences affecting clinical decision-making in emergency departments in NSW, Australia

In Australia, as elsewhere, the nature of triage decision making, patient referral, investigations, physical resources, triage policies, educational requirements and clinical expertise is often unclear and differs between organizations (Gerdtz & Bucknell 2000; Standen 1998). The study described here was undertaken in order to explore current triage practices throughout New South Wales (NSW) and to describe the range of clinical reasoning tasks performed by nurses.

Pressure ulcer prevention and care: a survey of current practice

The incidence and management of pressure ulcers in hospitalised patients is an ongoing concern for nurses. Efforts to prevent pressure ulcer development are plagued with inconsistencies and a general lack of best practice guidelines. Establishing current practice approaches to the assessment, prevention and management of pressure ulcers is a necessary first step in the implementation of evidence-based/best practice guidelines. Anecdotal evidence suggested a range of different approaches were being used in a Sydney metropolitan area health service (AHS) to assess patients to identify those at risk, to prevent pressure ulcers and to treat existing ulcers. A collaborative research project was undertaken to examine current practice and to explore the apparent clinical variance. It involved the distribution of a questionnaire to registered nurses working within the AHS (n = 2113) and a review of nursing policy documents in the various hospitals in the health service area. While the overall response rate was satisfactory (40%) many of the returned questionnaires were incomplete. Only 21% (n = 444) of the questionnaires were deemed suitable for analysis. The findings highlight a range of inconsistencies within and across nursing practice domains. Nurses generally do not use a tool to assess pressure ulcer risk potential, but rely on a range of practice procedures and risk indicators to determine risk potential of developing pressure ulcers. Repositioning patients is the most common approach used in an attempt to prevent the development of pressure ulcers, but additional measures are diverse. Most nurses seem to be familiar with modern wound dressings such as hydrocolloids, foams and alginates in the treatment of second and third stage ulceration. However, the care provided by some nurses reflects an adherence to outdated practices, including the use of water filled gloves, povidone iodine and gauze packing.

Unfinished business: interviewing family members of critically ill patients

This 'story from the field' emerges from qualitative research conducted with relatives of patients admitted to intensive care. A disturbing feature of researching the needs of family members of critically ill patients is the intense emotion that is often generated during the course of interviewing. For some the opportunity to talk about the experience of having a loved one in an intensive care unit was therapeutic; for others it meant anguish and despair as they relived the event that resulted in a life-threatening illness. Despite being a reasonably experienced educator and critical care nurse, I was unprepared for the intensity of feelings shown by many of the participants. I found that exposure to this kind of suffering was emotionally draining, experiencing the various roles of confidante, nurse, counsellor and researcher. It became important to share my thoughts and feelings and unwind with an independent friend and colleague as a way of debriefing. Methodological and ethical issues that arose included: generating a situation that potentially required therapeutic intervention; the impact on the 'purity' of data of becoming emotionally enmeshed; and the level of investigator preparedness when researching sensitive topics. The issue of walking away from an intensely emotional and intimate interview often leaves one with a sense of 'unfinished business'.

Lead exposure among lead-acid battery workers in Jamaica

To assess lead exposure in the Jamaican lead-acid battery industry, we surveyed three battery manufacturers (including 46 production workers) and 10 battery repair shops (including 23 battery repair workers). Engineering controls and respiratory protection were judged to be inadequate at battery manufacturers and battery repair shops. At manufacturers, 38 of 42 air samples for lead exceeded a work-shift time-weighted average concentration of 0.050 mg/m3 (range 0.030-5.3 mg/m3), and nine samples exceeded 0.50 mg/m3. Only one of seven air samples at repair shops exceeded 0.050 mg/m3 (range 0.003-0.066 mg/m3). Repair shop workers, however, had higher blood lead levels than manufacturing workers (65% vs. 28% with blood lead levels above 60 micrograms/dl, respectively). Manufacturing workers had a higher prevalence of safe hygienic practices and a recent interval of minimal production had occurred at one of the battery manufacturers. Workers with blood lead levels above 60 micrograms/dl tended to have higher prevalences of most symptoms of lead toxicity than did workers with lower blood lead levels, but this finding was not consistent or statistically significant. The relationship between zinc protoporphyrin concentrations and increasing blood lead concentrations was consistent with that described among workers in developed countries. The high risk of lead toxicity among Jamaican battery workers is consistent with studies of battery workers in other developing countries.

Using the Delphi technique to design a self-reporting triage survey tool

A useful addition to any researcher's methodological repertoire is the Delphi technique. This technique facilitates group communication to develop research items that are contextually specific. For the first time this method was utilised to develop a self-reporting triage survey tool that would explore current practice and begin to explore triage decision-making. The triage role is complex, often crisis-driven and demands speed and accuracy on the part of the triage nurse. This role involves patient assessment, initiating investigations, patient referral and management. The study used the Delphi technique to produce a triage survey tool that would assist in broadening our understanding of current triage practice within Australia.

The family and critical care nursing: a brief review of the literature

While there is generalised agreement in the literature on the importance of involving family members in critical care practice, there is little in regard to the roles and responsibilities of both nurses and families. There are many factors that can influence the nurse-family relationship, in both positive and negative dimension, and this relationship can impact significantly on the family member's experience of critical illness. It can also impact on his or her perception of need and need satisfaction. However, the complex nature of critical care practice may be too demanding, both physically and emotionally, for nurses to respond to many of the family's needs and concerns.

Sediment deposition rates on the continental margins of the eastern Arabian Sea using 210Pb, 137Cs and 14C

Eight gravity cores from the active eastern continental margins of the Arabian Sea were dated using 210Pbxs, 137Cs and 14C. The short-term (< or = 100 years) sedimentation rates range from 0.06 to 0.66 cm/year where as the long-term (> or = 1000 years) ones using AMS 14C on planktonic foraminifera varied from 0.004 to 0.13 cm/year. For long-term chronology (< or = 50,000 years) AMS dating of well-cleaned planktonic foraminifera is most suited.

Fossil fuel CO2 traced by radiocarbon in fifteen Chinese cities

China is an important fossil fuel CO₂ (CO_2ff) emitter and the international community is thus concerned with quantifying reductions in Chinese carbon emissions in the recent past. Compared to traditional statistical method, radiocarbon (¹⁴C) offers a different approach to quantify atmospheric CO₂ derived from fossil fuel emissions. Here, we carry out a multi-year (2011-2016) CO_2ff tracing by ¹⁴C in Xi'an, and a three-year (2014-2016) CO_2ff tracing in 15 Chinese cities. The Xi'an results show that average CO_2ff concentrations fell 35.9 ± 6.6% from 2014- 2016, compared to 2011-2013, and the timing of this decrease coincides with the implementation of nationwide carbon reduction measures in China, known as the Action Plan on Prevention and Control of Air Pollution. A WRF-Chem forward modeling simulation reveals that the CO_2ff in Xi'an is mainly derived from local sources, and a source apportionment combined stable-carbon isotope showed that the CO_2ff in this city is dominated by coal combustion (72.6 ± 10.4%). Strong CO_2ff differences are found between January and July in most Chinese cities. High CO_2ff concentrations often correspond to severe haze episodes and there are generally positive correlations between CO_2ff and fine particulate (PM_2.5) concentrations. Our study provides scientific data to understand the effects of CO_2ff reduction strategies in China that can be applied to other countries as well.

Fostering Nursing Research Among Nurse Clinicians in an Australian Area Health Service

BACKGROUND

The Nursing Research Centre for Adaptation in Health and Illness (NRCAHI) is a collaborative effort of the University of Sydney and Central Sydney Area Health Service (CSAHS) in Sydney, Australia. This article reports findings of a research needs-analysis of clinical nursing staff in CSAHS that was conducted to provide research training.

METHOD

A questionnaire was administered to a random sample of nurses working in CSAHS. The questionnaire gathered information about employment and demographic information, interest in research participation, current and future levels of research skills, and areas where skill and knowledge enhancement is desired.

RESULTS

Overall, nurses expressed low levels of perceived confidence, knowledge, and research skills. Results were used as the basis for developing a range of strategies designed to enhance research confidence and participation. These strategies were sufficiently flexible to cater for the needs of nurses with varying levels of research experience.

CONCLUSION

Strategies implemented by the NRCAHI in its first 4 years of operation have produced positive outcomes in terms of increased research participation.

A review of intensive care nurse staffing practices overseas: what lessons for Australia?

In view of market-driven health-care policies and the move to greater efficiencies within the health-care system, the cost of nursing care is being increasingly scrutinised. Different overseas practices are commonly cited as justification for changing practices within Australia. This study is based on a review of the literature on intensive care nurse staffing requirements in Australasia; specifically, New South Wales, the United States (US) and, to a lesser extent, Europe. It was found that looking to the US for cost-cutting strategies in intensive care units (ICUs) is based on a false premise: that we are comparing like with like. ICUs in the US have a different historical trajectory and culture, service wider constituencies, have technicians and unregistered personnel providing nursing care and do not provide demonstrably better outcomes or significant cost savings. Research indicates that continuous nursing care by trained professionals provides the best outcomes. If costs must be cut, technology, pharmaceuticals and laboratory tests should be targeted. Further, a greater commitment to the development of a 'progressive patient care' model in hospital planning is required, in order to establish or consolidate an intermediate level of nursing care between the ward and the ICU. Programs aiming to improve and continuously monitor patient care, such as adverse event monitoring, the prevention of unplanned extubation and facilitation of early extubation, should be instituted, as these have been shown to not only reduce ICU costs but also improve patient outcomes.

The Dose Reduction in Schizophrenia (DORIS) Study: a final report

Twenty-one medication-free chronic schizophrenics were randomly assigned to three treatment groups: 50% blockade of the bromocriptine growth hormone (GH) response, 100% blockade or 10 ng/ml haloperidol. Only seven of the 21 patients showed a significant improvement after 6 weeks in positive psychotic symptoms; six of the seven responders came from the 50 and 100% blockade groups, suggesting greater efficacy at lower doses. Fifty percent blockade was associated with an average daily haloperidol dose of 3.2 mg and plasma haloperidol levels below the limit of detection (< 1 ng/ml). 100% blockade was associated with a daily dose of 6.5 mg and a plasma haloperidol level of 1 ng/ml. Negative symptoms significantly improved in only four of the 21 patients, and three of these patients were from the 100% blockade group. Twenty-nine patients currently receiving 20 mg/day haloperidol were randomly assigned to three treatment groups: placebo, 100% blockade of the GH response and 10 ng/ml. Patients in the placebo group showed significant deterioration along both the positive and negative symptom dimensions. There were no significant symptom differences between the 100% blockade and the 10 ng/ml groups. The patients in the 100% blockade group had on average a daily dose reduction from 20 to 11 mg/day and a 65% reduction in the plasma haloperidol level. There was a 70% difference in the average daily dose for 100% blockade between the two study arms. The higher daily dose in the dose-reduction arm may reflect receptor up-regulation and/or other "tolerance'-like mechanisms associated with chronic neuroleptic administration.

Authentication of Chinese vintage liquors using bomb-pulse 14C

The older a bottle of Chinese vintage liquor is, the higher the price it commands. Driven by the potential for higher profits, some newly-founded distilleries openly sell liquor whose storage ages are exaggerated. In China, the market for vintage liquor has become fraught with uncertainty and a pressing need has arisen to establish an effective method to authenticate the age of vintage liquors. A radiocarbon (¹⁴C) dating method is described here that can verify cellar-stored years of Chinese liquors distilled within the last fifty years. Two different flavored Chinese liquors produced in “the golden triangular region” in the Upper Yangtze River region in southwest China, with known cellar-stored years, were analyzed to benchmark the technique. Strong flavored liquors are found to be consistent with local atmospheric Δ¹⁴C values. A small offset of 2–3 years between predicted vintage years of soy-sauce flavored liquors and strong flavored liquors is found to be associated with the fermentation cycle of certain varieties. The technique can measure cellar-stored years of a wide range of liquors including those with fundamentally different aromas. This demonstrates the strength of our method in identifying suspect Chinese vintage liquors.

The impact of COVID-19 lockdown on atmospheric CO2 in Xi'an, China

Lockdown measures to control the spread of the novel coronavirus disease (COVID-19) sharply limited energy consumption and carbon emissions. The lockdown effect on carbon emissions has been studied by many researchers using statistical approaches. However, the lockdown effect on atmospheric carbon dioxide (CO₂) on an urban scale remains unclear. Here we present CO₂ concentration and carbon isotopic (δ¹³C) measurements to assess the impact of COVID-19 control measures on atmospheric CO₂ in Xi'an, China. We find that CO₂ concentrations during the lockdown period were 7.5% lower than during the normal period (prior to the Spring Festival, Jan 25 to Feb 4, 2020). The observed CO_2excess (total CO₂ minus background CO₂) during the lockdown period was 52.3% lower than that during the normal period, and 35.7% lower than the estimated CO_2excess with the effect of weather removed. A Keeling plot shows that in contrast CO₂ concentrations and δ¹³C were weakly correlated (R² = 0.18) during the lockdown period, reflecting a change in CO₂ sources imposed by the curtailment of traffic and industrial emissions. Our study also show that the sharp reduction in atmospheric CO₂ during lockdown were short-lived, and returned to normal levels within months after lockdown measures were lifted.

Intensive care of the crush victim. Part 1

The victims of disasters, accidents and many forms of trauma are often trapped or wedged under and within rubble which can lead to crush injury. Prolonged immobility can also cause crush injury if the weight of a person's body compresses muscle and soft tissue for an extended period of time. Extensive muscular tissue pathology can result from the crush injury itself and once the pressure, or compressive force, is removed a predictable sequence of events can cause widespread haemodynamic and metabolic disturbances--the crush syndrome. Part one includes the mechanism of crush injury and the pathophysiology underlying the clinical manifestations of the crush syndrome. The aims of assessment and management are discussed as well as a brief review of the literature related to management of the local crush site and the potential problem of compartment syndrome. Part two involves a case study of a person who was trapped for 10-12 hours following a motor vehicle accident. This patient was transported to 2 country centres and then transferred to a major teaching hospital in Sydney. Discussions will centre on the classic nature of the case, and the findings and management strategies will be correlated with the literature. The implications for nursing practice are explored and include the need for astute assessment and monitoring based on a thorough understanding of the sequelae of crush. Interventions are aimed at minimising discomfort and reducing complications both at the local crush site and generalised systemic level. Close monitoring and interpretation of the patient's response to interventions is essential for the continuation of definitive care.