Methane sources and sinks in the Arctic are poorly quantified. In particular, methane emissions from the Arctic Ocean and the potential sink capacity are still under debate. In this context sea ice ...impact on and the intense cycling of methane between sea ice and Polar surface water (PSW) becomes pivotal. We report on methane super- and under-saturation in PSW in the Eurasian Basin (EB), strongly linked to sea ice-ocean interactions. In the southern EB under-saturation in PSW is caused by both inflow of warm Atlantic water and short-time contact with sea ice. By comparison in the northern EB long-time sea ice-PSW contact triggered by freezing and melting events induces a methane excess. We reveal the Ttranspolar Drift Stream as crucial for methane transport and show that inter-annual shifts in sea ice drift patterns generate inter-annually patchy methane excess in PSW. Using backward trajectories combined with δ
O signatures of sea ice cores we determine the sea ice source regions to be in the Laptev Sea Polynyas and the off shelf regime in 2011 and 2015, respectively. We denote the Transpolar Drift regime as decisive for the fate of methane released on the Siberian shelves.
We report for the first time on the discovery of calcium carbonate crystals as ikaite (CaCO3·6H2O) in sea ice from the Arctic (Kongsfjorden, Svalbard) as confirmed by morphology and indirectly by ...X-ray diffraction as well as XANES spectroscopy of its amorophous decomposition product. This finding demonstrates that the precipitation of calcium carbonate during the freezing of sea ice is not restricted to the Antarctic, where it was observed for the first time in 2008. This observation is an important step in the quest to quantify its impact on the sea ice driven carbon cycle.
Proton radiography’s utilization of positively charged probing particles makes it susceptible to potential influences from electromagnetic forces generated at the target object. In this work, we ...investigate how the 800 MeV proton radiography system of Los Alamos National Laboratory would respond to such influences with intentions to develop proton radiography/deflectometry diagnostics capable of probing electromagnetic fields inside dynamically changing objects. To understand how the proton radiography system responds to object-generated electromagnetic fields, a series of simulations were performed, which map proton trajectories through the system. This leads to an understanding of how the radiographic images, normally dominated by multiple Coulomb scattering, would be modified. The simulations also highlight novel ways in which additional data could be collected to glean more information about electromagnetic influences within and around the target object.
Utilizing the highly correlated quantum NOON states of spins, we have implemented a proof-of-principle quantum thermometer using the NMR technique for measuring the variation of local magnetic field ...with the temperature. The system used was the star topology system of hexafluorophosphate molecules, and the thermometer showed a sensitivity of
85
nT
/
∘
C. Using the hexafluorophosphate and the trimethylphosphite spin systems, we have quantified the advantage of the quantum protocol over the classical one for measuring magnetic field. The quantum protocol showed the best performance for the sensing time of
T
max
=
20
ms, where the errors in the measurement scaled as the Heisenberg limit 1 /
N
. The thermometer implementation provided measurements in the temperature with errors scaling approximately with the Heisenberg limit, more precisely
N
-
0.94
.
Experimental studies showed that controlled variable ventilation (CVV) yielded better pulmonary function compared to non-variable ventilation (CNV) in injured lungs. We hypothesized that CVV improves ...intraoperative and postoperative respiratory function in patients undergoing open abdominal surgery.
Fifty patients planned for open abdominal surgery lasting >3 h were randomly assigned to receive either CVV or CNV. Mean tidal volumes and PEEP were set at 8 ml kg−1 (predicted body weight) and 5 cm H2O, respectively. In CVV, tidal volumes varied randomly, following a normal distribution, on a breath-by-breath basis. The primary endpoint was the forced vital capacity (FVC) on postoperative Day 1. Secondary endpoints were oxygenation, non-aerated lung volume, distribution of ventilation, and pulmonary and extrapulmonary complications until postoperative Day 5.
FVC did not differ significantly between CVV and CNV on postoperative Day 1, 61.5 (standard deviation 22.1) % vs 61.9 (23.6) %, respectively; mean 95% confidence interval (CI) difference, −0.4 (−13.2–14.0), P=0.95. Intraoperatively, CVV did not result in improved respiratory function, haemodynamics, or redistribution of ventilation compared to CNV. Postoperatively, FVC, forced expiratory volume at the first second (FEV1), and FEV1/FVC deteriorated, while atelectasis volume and plasma levels of interleukin-6 and interleukin-8 increased, but values did not differ between groups. The incidence of postoperative pulmonary and extrapulmonary complications was comparable in CVV and CNV.
In patients undergoing open abdominal surgery, CVV did not improve intraoperative and postoperative respiratory function compared with CNV.
NCT 01683578.
Purpose
To test if an encircling band improves outcomes in vitrectomy for pseudophakic retinal detachment (PRD) with inferior or with multiple (4 or more) breaks.
Methods
Subgroup analysis of a ...prospective randomized controlled multicenter trial in patients with uncomplicated PRD assigned either to 20 G vitrectomy plus encircling band (group E1), or 20 G vitrectomy without any buckle (group C), or 23/25 G vitrectomy without any buckle (group E2). The primary endpoint was defined as no indication for any retina reattaching procedure during the review period of 6 months. One hundred out of 257 patients were identified with inferior breaks and 63 patients had 4 or more breaks.
Results
In patients with retinal breaks between 5:00 and 7:00, treatment was successful in 77.4% (24/31, treatment arm E1) versus 57.1% (16/28, treatment arm C) (
p
= 0.301, odds ratio (OR) 1.83, 95% confidence interval (CI) 0.48 to 7.17). In patients with multiple breaks, success rates were 68.2% (15/22, E1) versus. 72.4% (21/29, C,
p
= 0.46, OR 0.52, CI 0.08–3.65).
Conclusion
Combining an encircling band with vitrectomy in patients with pseudophakic retinal detachment and inferior or multiple breaks does not significantly improve primary anatomical success in comparison to treatment with 20 G or 23/25 G vitrectomy alone.
Accurate soil information is critically important for forest management planning and operations but is challenging to map. Digital soil mapping (DSM) improves upon the limitations of conventional ...soil mapping by explicitly linking a variety of environmental data layers to spatial soil point data sets to continuously predict soil variability across a landscape. Thus far, much DSM research has focussed on the development of ultrafine-resolution soil maps within agricultural systems; however, increasing availability of light detection and ranging (LiDAR) data presents new opportunities to apply DSM to support forest resource applications at multiple scales. This project describes a DSM workflow using LiDAR-derived elevation data and machine learning models (MLMs) to predict key forest soil attributes. A case study in the Hearst Forest in northeastern Ontario, Canada, is used to illustrate the workflow. We applied multiple MLMs to the Hearst Forest to predict soil moisture regime and textural class. Both qualitative and quantitative assessment pointed to the random forest MLM producing the best maps (63% accuracy for moisture regime and 66% accuracy for textural class). Where error occurred, soils were typically misclassified to neighbouring classes. This standardized, flexible workflow is a valuable tool for practitioners that want to undertake DSM as part of forest resource management and planning.
Celotno besedilo
Dostopno za:
BF, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Purpose
To analyse the willingness for postmortem cornea donation in Germany.
Methods
Employees in two cities (UKM, UKS), and university hospitals (STM, STE), members of the German Ophthalmological ...Society (DOG), and employees of an automobile company (BO) participated in a questionnaire about postmortem cornea donation attitudes. The questionnaire consisted of demographic items, motives concerning postmortem cornea donation, general attitudes toward donation, and questions concerning the perceived needs for information about donation. The statistical analyses included logistic regression with the target parameter of 'willingness to donate cornea postmortem'.
Results
Of the participants, 67.7 % (UKM, UKS), 70.9 % (STM, STE), 70.8 % (BO), and 79.4 % (DOG) declared their intention to donate their corneas postmortem. Younger age (
p
< 0.001), poorer general health (
p
< 0.05), faith in an eternal life (
p
< 0.05), disagreement with brain death diagnostics (
p
< 0.001), fear of receiving worse medical treatment (
p
< 0.001), and fear of the commercialization of organs (
p
< 0.001) were found to be risk factors for a negative attitude toward postmortem cornea. The majority of participants (57.4 %) indicated that additional information about donation would be appreciated, and the internet (69.9 %) was considered the most appropriate means for conveying this information.
Conclusions
Emotional items were revealed to be the most relevant factors influencing the willingness to donate cornea postmortem, which may be counteracted by means of public education. The relatively low willingness among the medical staff contrasts with previous observations in a professional ophthalmologic society.
PDF
