170,954 research outputs found
Meteorological synoptical observations from Neumayer Station, 1981-03 to 2011-12, reference list of 372 datasets
No full textERA-Interim reanalysis data and data of the Hadley Centre Global Environmental Model version 2 (HadGEM2) are compared with continuous meteorological observations of near-surface wind and temperature carried out for more than 30 years at Neumayer station, situated on the Ekstro¨m Ice Shelf of Antarctica. Significant temperature correlations between Neumayer climate and the climate of both the interior of the Antarctic continent and oceanic regions north of Neumayer are investigated using observational data and model data. Mean sea level pressure fluctuations at Neumayer can be connected to changes in the Southern Annular Mode (SAM). Shortcomings in the ERA-Interim reanalysis data with spurious trends of up to 7 C over 31 years are identified at several places in Antarctica. Furthermore, it is shown that katabatic winds in both the ERA-Interim reanalysis data and in the HadGEM2 climate model are underrepresented in frequency and speed, presumably due to the problems in representing topography in these relatively coarse resolution models. This may be one reason for the positive 2m air temperature bias of 3 C in the models at Neumayer station. The results of this study reemphasize that climatic trends in regions with a low station density can not be assessed solely from model data. Thus, it is absolutely necessary to maintain polar observatories such as Neumayer station to quantify climate change over the Southern Ocean and Antarctica
Genetics and Epigenetics of Sex Bias: Insights from Human Cancer and Autoimmunity
No full textHigh-throughput sequencing and genome-wide association studies have revealed a sex bias in human diseases. The underlying molecular mechanisms remain, however, unknown. Here, we cover recent advances in cancer and autoimmunity focusing on intrinsic genetic and epigenetic differences underlying sex biases in human disease. These studies reveal a central role of genome regulatory mechanisms including genome repair, chromosome folding, and epigenetic regulation in dictating the sex bias. These highlight the importance of considering sex as a variable in both basic science and clinical investigations. Understanding the molecular mechanisms underlying sex bias in human diseases will be instrumental in making a first step forwards into the era of personalized medicine
Daily to intraseasonal oscillations at Antarctic research station Neumayer
No full textHigh temporal resolution (three hours) records of temperature, wind speed and sea level pressure
recorded at Antarctic research station Neumayer (708S, 88W) during 1982–2011 are analysed to identify
oscillations from daily to intraseasonal timescales. The diurnal cycle dominates the three-hourly time series
of temperature during the Antarctic summer and is almost absent during winter. In contrast, the three-hourly
time series of wind speed and sea level pressure show a weak diurnal cycle. The dominant pattern of the
intraseasonal variability of these quantities, which captures the out-of-phase variation of temperature and
wind speed with sea level pressure, shows enhanced variability at timescales of , 40 days and , 80 days,
respectively. Correlation and composite analysis reveal that these oscillations may be related to tropical
intraseasonal oscillations via large-scale eastward propagating atmospheric circulation wave-trains. The
second pattern of intraseasonal variability, which captures in-phase variations of temperature, wind and sea
level pressure, shows enhanced variability at timescales of , 35, , 60 and , 120 days. These oscillations
are attributed to the Southern Annular Mode/Antarctic Oscillation (SAM/AAO) which shows enhanced
variability at these timescales. We argue that intraseasonal oscillations of tropical climate and SAM/AAO are
related to distinct patterns of climate variables measured at Neumayer
Wet chemical ozone measurements at Georg von Neumayer station, Antarctica, during 1982-1994
No full textOzone measurements began in 1982 at the Georg von Neumayer Station on the Ekstrom Ice Shelf in Antarctica and continued until 1996. The station was about 15 km from the ice edge. In the first year, a so-called trace substance observatory was set up 1.5 km south of the station by the University of Heidelberg (Weller et al. 2007) in order to be able to take a wide variety of air-chemical samples. Some experience had to be gained under the extreme conditions. For some devices, frost settled in the air intake shaft. The ozone machine had its own Teflon suction line, which worked without any problems. The bubbler, on the other hand, was sensitive to direct sunlight, causing the display to change erratically. This was successfully prevented by a cardboard sunshade. An aerosol filter was installed at the outlet of the device in order to separate the solution droplets formed in the aerator so that aerosol measuring devices and in particular a particle counter was not disturbed. The ozone device also survived an emergency power operation during which the temperature in the trace substance observatory dropped to -22°C. In 1984/1985, the ozone device was not housed in the trace substance observatory, but directly in the station in a special trace substance laboratory. The intake line was moved to the outside in the exit chimney of the station. Height above ground was rather 1.5m instead of 2.5m at that time. The formation of a snow plug in the intake line initially cut off the air supply. In this way, experience in the operation of the device was gradually gained. In 1992, the Georg von Neumayer station was replaced by a new building about 10 km south-southwest of the first station. In January 1992, due to frequent trips between GvN and the new Neumayer-II building, the trace substance measurements were repeatedly disrupted, so that operations were temporarily suspended
Meteorological synoptical observations from Neumayer Station, 1981-03 to 2011-12, reference list of 372 datasets
No full textERA-Interim reanalysis data and data of the Hadley Centre Global Environmental Model version 2 (HadGEM2) are compared with continuous meteorological observations of near-surface wind and temperature carried out for more than 30 years at Neumayer station, situated on the Ekstro¨m Ice Shelf of Antarctica. Significant temperature correlations between Neumayer climate and the climate of both the interior of the Antarctic continent and oceanic regions north of Neumayer are investigated using observational data and model data. Mean sea level pressure fluctuations at Neumayer can be connected to changes in the Southern Annular Mode (SAM). Shortcomings in the ERA-Interim reanalysis data with spurious trends of up to 7 C over 31 years are identified at several places in Antarctica. Furthermore, it is shown that katabatic winds in both the ERA-Interim reanalysis data and in the HadGEM2 climate model are underrepresented in frequency and speed, presumably due to the problems in representing topography in these relatively coarse resolution models. This may be one reason for the positive 2m air temperature bias of 3 C in the models at Neumayer station. The results of this study reemphasize that climatic trends in regions with a low station density can not be assessed solely from model data. Thus, it is absolutely necessary to maintain polar observatories such as Neumayer station to quantify climate change over the Southern Ocean and Antarctica
Quantifying the snowmelt–albedo feedback at Neumayer Station, East Antarctica
No full textWe use 24 years (1992–2016) of high-quality meteorological observations at
Neumayer Station, East Antarctica, to force a surface energy balance model.
The modelled 24-year cumulative surface melt at Neumayer amounts to 1154 mm
water equivalent (w.e.), with only a small uncertainty (±3 mm w.e.)
from random measurement errors. Results are more sensitive to the chosen
value for the surface momentum roughness length and new snow density,
yielding a range of 900–1220 mm w.e. Melt at Neumayer occurs only in the
months November to February, with a summer average of 50 mm w.e. and large
interannual variability (σ=42 mm w.e.). This is a small value
compared to an annual average (1992–2016) accumulation of 415±86 mm w.e. Absorbed shortwave radiation is the dominant driver of temporal
melt variability at Neumayer. To assess the importance of the
snowmelt–albedo feedback we include and calibrate an albedo parameterisation
in the surface energy balance model. We show that, without the
snowmelt–albedo feedback, surface melt at Neumayer would be approximately
3 times weaker, demonstrating how important it is to correctly represent this
feedback in model simulations of surface melt in Antarctica.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Aspects of weather parameters at Neumayer station, Antarctica, and their representation in reanalysis and climate model data
No full textERA-Interim reanalysis data and data of the Hadley Centre Global Environmental Model version 2
(HadGEM2) are compared with continuous meteorological observations of near-surface wind and
temperature carried out for more than 30 years at Neumayer station, situated on the Ekström Ice Shelf of
Antarctica. Significant temperature correlations between Neumayer climate and the climate of both the
interior of the Antarctic continent and oceanic regions north of Neumayer are investigated using
observational data and model data. Mean sea level pressure fluctuations at Neumayer can be connected to
changes in the Southern Annular Mode (SAM). Shortcomings in the ERA-Interim reanalysis data with
spurious trends of up to 7 °C over 31 years are identified at several places in Antarctica. Furthermore, it is
shown that katabatic winds in both the ERA-Interim reanalysis data and in the HadGEM2 climate model are
underrepresented in frequency and speed, presumably due to the problems in representing topography in
these relatively coarse resolution models. This may be one reason for the positive 2m air temperature bias of
3 °C in the models at Neumayer station. The results of this study reemphasize that climatic trends in regions
with a low station density can not be assessed solely from model data. Thus, it is absolutely necessary to
maintain polar observatories such as Neumayer station to quantify climate change over the Southern Ocean
and Antarctica
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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