The global circulation of the oceans and the atmosphere transports heat
around the Earth. Broecker and Denton suggested that changes
in the global ocean circulation might have triggered or enhanced ...the glacial-interglacial
cycles. But proxy data for past circulation taken from sediment cores in the
South Atlantic Ocean have yielded conflicting interpretations of ocean circulation
in glacial times-δ13C variations in benthic foraminifera support the idea of a glacial weakening or shutdown
of North Atlantic Deep Water production, whereas other proxies, such as Cd/Ca,
Ba/Ca and 231Pa/230Th ratios, show little change
from the Last Glacial Maximum to the Holocene epoch.
Here we report neodymium isotope ratios from the dispersed Fe-Mn oxide
component of two southeast Atlantic sediment cores. Both cores show variations
that tend towards North Atlantic signatures during the warm marine isotope
stages 1 and 3, whereas for the full glacial stages 2 and 4 they are closer
to Pacific Ocean signatures. We conclude that the export of North Atlantic
Deep Water to the Southern Ocean has resembled present-day conditions during
the warm climate intervals, but was reduced during the cold stages. An increase
in biological productivity may explain the various proxy data during the times
of reduced North Atlantic Deep Water export.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Factors as age, sex, smoking, duration of leg pain, working status, type/level of disc herniation and psychosocial factors have been demonstrated to be of importance for short-term results after ...lumbar discectomy. There are few studies with long-term follow-up. In this prospective study of lumbar disc herniation patients undergoing surgery, the result was evaluated at 2 and 5–10 (mean 7.3) years after surgery. Predictive factors for satisfaction with treatment and objective outcome were investigated. Out of the included 171 patients undergoing lumbar discectomy, 154 (90%) patients completed the 2-year follow-up and 140 (81%) completed the long-term follow-up. Baseline data and questionnaires about leg- and back pain intensity (VAS), duration of leg pain, disability (Oswestry Disability Index), depression (Zung Depression Scale), sick leave and employment status were obtained preoperatively, at 2-year- and long-term follow-up. Primary outcome included patient satisfaction with treatment (at both time points) and assessment of an independent observer at the 2-year follow-up. Secondary outcomes at 2-year follow-up were improvement of leg and back pain, working capacity and the need for analgesics or sleeping pills. In about 70% of the patients excellent or good overall result was reported at both follow-ups, with subjective outcome measurements. The objective evaluation after 2 years was in agreement with this result. Time on sick leave was found to be a clinically important predictor of the primary outcomes, with a potential of changing the probability of a satisfactory outcome (both objective and subjective) from around 50% (sick leave >3 months) to 80% (sick leave <2 months). Time on sick leave was also an important predictor for several of the secondary outcomes; e.g. working capacity and the need for analgesics.
The cycling of climate into and out of glacial states in response to orbital forcing illustrates the important role of feedbacks in the Earth system. In this contribution, the Geophysical Fluid ...Dynamics Laboratory coupled ocean‐atmosphere model is used to qualitatively assess how changes in the Earth's precessional parameters may have impacted Atlantic Meridional Ocean Circulation and Southern Ocean dynamics. The Southern Ocean region responds to precessional forcing similar to that of the Last Glacial Maximum with a slight shift in maximum average annual wind stress, a reduction in austral winter wind stress, and an increase in austral winter sea ice. During austral summer, stratification and wind stress increase, Changes in the temperature and density of the North Atlantic lead to a decrease in Atlantic Meridional Overturning Circulation. Together these changes contribute to aging of the global deep ocean, except around Antarctica where enhanced local convection decreases the age of upwelling waters. These circulation changes may have implications for a precessionally driven feedback that contributes to enhanced storage of CO2 in the deep ocean and a reduction in atmospheric CO2.
Plain Language Summary
The Earth has cycled into and out of ice ages over last 2.6 million years. The precise factors that cause these changes in climate are not fully understood. The correspondence between the Earth's climate and the Earth's position in space suggests that there is a connection between the two. In this work we use a fully coupled global climate model to explore whether the season during which Earth is closest to the Sun has an impact on ocean circulation. We use two model runs, one having the Earth in a northern hemisphere winter perihelion (close pass) position and another placing the Earth in a northern hemisphere summer perihelion. We find that the northern hemisphere winter perihelion position is associated with changes in Southern Ocean circulation that include an increase in upwelling and a decrease in the age of the upwelled water. We also find that deep ocean circulation in the Atlantic Ocean decreases and that global ocean deep waters increase in age. The observed changes are consistent with the idea that a Northern Hemisphere winter perihelion position may contribute to glacial interglacial climate change and a drawdown of atmospheric CO2.
Key Points
Precessional forcing that places the Earth at a boreal winter perihelion position causes an increase in wind stress and Ekman upwelling during austral summer/fall and a decrease during austral winter/spring in the high‐latitude Southern Ocean
Global deepwater age responds to a boreal winter perihelion position by increasing ~200 years
Atlantic Meridional Overturning Circulation decreases in response to a boreal winter perihelion position. Southern Ocean ventilation increases
Prospective, single centre study.
Previous studies have suggested a relationship between stress reaction and elevated levels of prolactine. The aim of the present study was to investigate if there ...was a relationship between s-prolactine and menstrual cycle status following spinal cord injury (SCI).
Spinal Cord Injury Unit, Göteborg, Sweden.
S-prolactine and menstrual cycle status were investigated in 16 consecutive women with SCI, treated at the SCI Unit, Sahlgrens University Hospital, Göteborg, Sweden. Level of injury ranged from C1 to L5, ASIA A-D. Mean age at injury was 45 years (range 20-79).
S-Prolactine showed a mean value of 741 mIU/l (standard deviation (s.d.): 625; 95% confidence interval (CI): 435-1788 mIU/l, reference value <400 mIU/l). When dividing the group according to fertility status we found hyperprolactinaemia in the women who were in childbearing age (n=9): mean value 1050 mIU/l (s.d.: 678; 95% CI: 607-1493 mIU/ml), whereas it was normal in the group in menopause (n=7): mean value 343 mIU/l (s.d.: 185, 95% CI: 206-480 mIU/l) (P<0.01 when comparing groups). The group that developed amenorrhoea showed the highest values of s-prolactine. All values but one was normalised 3-6 months later.
Amenorrhoea following SCI is correlated to level of s-prolactine. We found no correlation between level of s-prolactine and level or degree of injury.
This quality improvement project involved a multi-pronged, evidence-based approach to improving catheter associated urinary tract infections (CAUTIs) in hospitalized adult patients. Combining unit ...culture with current literature, the plan, do, study, act model, several interventions were used to evaluate the impact on CAUTI reduction and utilization. Opportunities exist to improve CAUTI rates to meet national and state benchmarks. CAUTI causes increased morbidity, mortality, decreased patient satisfaction, and financial consequences for institutions who have CAUTIs occur during hospitalizations. A multi-modal approach to reducing the utilization of indwelling urinary catheters using a protocol was employed. The results indicated a reduction in duration time in the post-intervention group without a change in CAUTI rates. The bladder emptying protocol (BEP) did not affect utilization rates; however, there were only two participants able to take part in this protocol. Sustainability includes writing this protocol into hospital policy and utilizing the protocol across other units within the organization. There were positive results, including decreasing duration time by 50% in the post-intervention group which possibly led to no CAUTI development in the post-intervention group.Keywords: CAUTI, nurse-driven removal protocol, indwelling urinary catheter, urinary tract infection.
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