bluuebunny/crossref_metadata_2025 huggingface dataset:
The impact of temporary clipping during aneurysm surgery on the incidence of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage
Authors: Malinova Vesna , Schatlo Bawarjan , Voit Martin , Suntheim Patricia , Rohde Veit , Mielke Dorothee
Published: September 2017

OBJECTIVE

Clipping of a ruptured intracranial aneurysm requires some degree of vessel manipulation, which in turn is believed to contribute to vasoconstriction. One of the techniques used during surgery is temporary clipping of the parent vessel. Temporary clipping may either be mandatory in cases of premature rupture (rescue) or represent a precautionary or facilitating surgical step (elective). The aim of this study was to study the association between temporary clipping during aneurysm surgery and the incidence of vasospasm and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage (aSAH) in a large clinical series.

METHODS

Seven hundred seventy-eight patients who underwent surgical aneurysm treatment after aSAH were retrospectively included in the study. In addition to surgical parameters, the authors recorded transcranial Doppler (TCD) sonography–documented vasospasm (TCD-vasospasm, blood flow acceleration > 120 cm/sec), delayed ischemic neurological deficits (DINDs), and delayed cerebral infarction (DCI). Multivariate binary logistic regression analysis was applied to assess the association between temporary clipping, vasospasm, DIND, and DCI.

RESULTS

Temporary clipping was performed in 338 (43.4%) of 778 patients during aneurysm surgery. TCD sonographic flow acceleration developed in 370 (47.6%), DINDs in 123 (15.8%), and DCI in 97 (12.5%). Patients with temporary clipping showed no significant increase in the incidence of TCD-vasospasm compared with patients without temporary clipping (49% vs 48%, respectively; p = 0.60). DINDs developed in 12% of patients with temporary clipping and 18% of those without temporary clipping (p = 0.01). DCI occurred in 9% of patients with temporary clipping and 15% of those without temporary clipping (p = 0.02). The need for rescue temporary clipping was a predictor for DCI; 19.5% of patients in the rescue temporary clipping group but only 11.3% in the elective temporary clipping group had infarcts (p = 0.02). Elective temporary clipping was not associated with TCD-vasospasm (p = 0.31), DIND (p = 0.18), or DCI (p = 0.06).

CONCLUSIONS

Temporary clipping did not contribute to a higher rate of TCD-vasospasm, DIND, or DCI in comparison with rates in patients without temporary clipping. In contrast, there was an association between temporary clipping and a lower incidence of DINDs and DCI. There is no reason to be hesitant in using elective temporary clipping if deemed appropriate.
Atmospheric Lead in Antarctic Ice during the Last Climatic Cycle
Authors: Boutron Claude F. , Patterson Clair C. , Lorius Claude , Petrov V.N. , Barkov N.I.
Published: September 2017

Concentrations of lead (Pb) have been measured by the ultra-clean isotope dilution mass spectrometry technique in various sections of the Antarctic Dome C and Vostok deep ice cores, whose ages range from 3.85 to 155 ka B.P., in order to assess the natural, pre-human, sources of this toxic heavy metal in the global troposphere. Pb concentrations were very low, as low as about 0.3 pg Pb/g during the Holocene and probably during the last interglacial and part of the last ice age. On the other hand, they were quite high, up to about 40 pg Pb/g, during the Last Glacial Maximum and at the end of the penultimate ice age. Wind-blown dust from crustal rock and soil appears to be the main natural source of Pb in the global troposphere. Pb contribution from volcanoes is significant during periods of low Pb only. Contribution from the oceans is insignificant.
Glaciological Investigations in the Crête Area, Central Greenland: A Search for a new Deep-Drilling Site
Authors: Clausen H.B. , Gundestrup N.S. , Johnsen S.J. , Bindschadler R. , Zwally J.
Published: September 2017

The results of the 1984-85 post-GISP campaigns in central Greenland are presented. Eight ice cores were obtained, some spanning up to 360 years. We present:

I.

Geographical positions and elevations at the drill sites,

II.

Density and temperature in the bore holes,

III.

Filtered δ18O profiles and accumulation-rate variations along the ice cores.

The δ18O and accumulation profiles, along with those from the 400 m Crête ice core obtained in 1974, are compared.

The accumulation-rate series over a large region have a very high coherence. This indicates that a single bore hole in this region would give a representative accumulation time series over a long period. Further, it appears that for this region there is a linear relation between the measured annual accumulation rate and the mean annual δ18O values. Thus the area between Crête and Summit, just west of the ice divide, seems to be favorable for a deep-drilling operation.
The Effects of Wind on δ(18O) and Accumulation Give an Inferred Record of Seasonal δ Amplitude From the Agassiz Ice Cap, Ellesmere Island, Canada
Authors: Fisher D.A. , Koerner R.M.
Published: September 2017

Wind plays an important role in determining accumulation and δ(18O) on some ice caps. Three surface-to-bed cores spaced about 1 km apart have been taken on a flow line of the Agassiz Ice Cap, Ellesmere Island. The A84 core comes from the top of a local dome. The A79 core is 1200 m down the flow line, but very close to the ridge through the local dome. The A77 core is 1100m from A79 and well away from the ridge. The ridge causes wind turbulence, which removes or scours the soft winter snow from the A84 and A79 sites. No snow is scoured from the A77 site. Because of scour the retained accumulation and average δ(l8O) are different. The accumulations are 17.5, 11.5, 9.7 cm/a (ice equivalent) at A77, A79 and A84 respectively and the corresponding surface δs are –30.40, -27.90 and –27.05‰. The core records were dated by annual layer thicknesses and by identification of electrical conductivity measurement (ECM) acid peaks. With the three cores accurately aligned we examine the (δA84-δA77) and (δA84-δA79) time series. Significant variations in these difference series are interpreted as being caused by changes in the seasonal δ amplitude, which is then explained by changes in sea-ice cover. A seasonal δ amplitude series independently obtained from the Devon Island ice cap δ noise record is consistent with that from the Agassiz Ice Cap sites.
Trace-Acid Ion Content of Shallow Snow and Ice Cores from Mountain Sites in Western Canada
Authors: Holdsworth G. , Krouse H.R. , Peake E.
Published: September 2017

An historical record of the deposition of common acids is contained in snow and ice cores taken from suitable sites in the accumulation zone of certain glaciers. Spatial and time-series data sets for trace-mineral acids have been obtained from snow-pit samples and ice cores from a number of mountain sites in Alberta, British Columbia, and the Northwest and Yukon Territories. In Alberta, it is possible to use temperate firn sites above 3460 m, although elution occurs during certain summers as indicated by isotopic and ionic data. This would also apply to sites of a similar latitude (52°±2°N) in British Columbia. In the Yukon Territory (≥60.5°N) reliable time series for the acid anions may be obtained from sites at altitudes above 3000 m. Elution provides a natural control for demonstrating that field sampling and subsequent analytical procedures do not introduce significant contamination. The Yukon data are compared with the net annual accumulation rate and with altitude. Recent data from the 5340 m Mt Logan site do not indicate any significant increase in natural background levels of snow acidity. Lightning, which is responsible for numerous forest fires in all provinces, is a possible natural source of nitric acid. Spring-summer peaks in nitrate concentration usually occur. In addition, forest-fire smoke may be a significant contributor to the mountain snow-pack chemistry in some years and must be considered when interpreting the Mt Logan core data. One Yukon profile seems to contain the signature from the 1986 Augustine volcanic eruption.
Air Mixing in Firn and the Age of the Air at Pore Close-Off
Authors: Schwander J. , Stauffer B. , Sigg A.
Published: September 2017

The air trapped in the bubbles of natural ice is not the same age as the surrounding ice. This is due to the fact that the air is enclosed in isolated bubbles only at the depth of the firn–ice transition. Within the overlying porous firn layer the air is able to mix and to exchange to a certain degree with the atmosphere. The age difference between ice and air is given by the age of the ice at pore close-off, less the mixing delay. Also, there is an age distribution due to diffusive smoothing and due to the gradual enclosure of the air at the firn–ice transition. Knowledge of this age relation is necessary for the interpretation of climatic parameters measured on ice cores. This work concentrates on the effect of diffusive mixing. We report on measurements of the diffusivity of CO2 and O2 (in N2) in firn samples from Siple Station, Antarctica. It is shown that the dominant mixing process is molecular diffusion. The diffusion coefficient depends approximately linearly on the porosity. A one-dimensional diffusion model has been used to calculate the air mixing in firn at Siple Station (Antarctica), at the South Pole, and at Station Crête (Greenland). An exchange time of between 10 and 50 years is obtained.
Stable-Isotope Ratios and Concentration of CO2 in Air from Polar Ice Cores
Authors: Siegenthaler U. , Friedli H. , Loetscher H. , Moor E. , Neftel A. , Oeschger H. , Stauffer B.
Published: September 2017

Analyses of air trapped in an ice core from the South Pole indicate that the CO2 concentration may have increased by about 10 ppm and that the 13C/12C ratio decreased slightly in the thirteenth century. These changes, if really of atmospheric origin, must be due to a significant input into the atmosphere of CO2, either of biogenic or of oceanic origin.

18O/16O ratios in CO2 from different ice cores are much lower than those which have been observed in atmospheric carbon dioxide. A possible explanation is that the CO2 has equilibrated isotopically with the ice. We have calculated equilibrium isotope-fractionation factors between ice and carbon dioxide and found that the observed 18O/16O ratios of CO2 are indeed near isotopic equilibrium with the ice. This indicates that an exchange of oxygen atoms probably occurs between ice and included CO2.
Seasonal Variations in Hydrogen Peroxide in Polar Ice Cores
Authors: Sigg Andreas , Neftel Albrecht
Published: September 2017

Hydrogen peroxide is present in polar snow and ice in remarkably high concentrations. With values up to 300 ppb, H2O2 is one of the most concentrated impurities in polar ice. We present a continuous H2O2 firn record from Siple Station (Antarctica); it covers the last 83 years with a resolution of 10–20 samples per year. A very strong seasonality is present in this record. This seasonality is also observed in a Greenland ice core from Dye 3, where we have continuously measured the top 10 m with the same resolution. The maximum concentrations correspond to summer snow layers and can exceed winter snow concentrations by a factor of 10. This property makes H2O2 a useful tracer for dating suitable cores by counting annual layers. The different steps needed to relate the atmospheric to the ice–core H2O2 concentration are discussed. As with isotopic tracers, diffusion in the firn smooths the original H2O2 concentration profile.
Co-Isotopic Signature of Two Mechanisms of Basal-Ice Formation in Arctic Outlet Glaciers
Authors: Souchez R. , Lorrain R. , Tison J.L. , Jouzel J.
Published: September 2017

Basal ice is formed by regelation as a consequence of both pressure-melting and freezing-on at the glacier sole.

A study of D/H and 18O/16O ratios in basal ice from five Arctic outlet glaciers indicates that a co-isotopic signature exists for these two mechanisms of formation.

The dispersed and stratified facies of basal ice present in these glaciers are related respectively to the occurrence of regelation and to freezing-on at the glacier base. Their origin is tentatively connected with the onset of basal sliding and the zone of bed decoupling due to basal water pressure in these Arctic outlet glaciers.
Continuous and High-Resolution Ice-Core Analysis (Abstract)
Authors: Hammer C.U.
Published: September 2017

The aim of this paper is to evaluate and exemplify the potential of continuous and high-resolution ice-core analysis in atmospheric-climatic research.

At present only a few ice-core components of current interest can be measured continuously with high resolution along the cores. In this paper, the techniques of in-situ or “in the laboratory” continuous high-resolution measurement of solid-liquid electrical conductivity, pH, dust and anions will be presented and discussed. In particular, results from individual precipitation samples, seasonal changes, rare events, and the comparison of results from various Antarctic and Greenland ice cores will be discussed.
Chemical Composition of Insoluble Particles in an Ice Cap on Storøya, Svalbard (Abstract)
Authors: Heintzenberg Jost , Källström Margareta , Hansson Hans-Christen , Jonsson Stig
Published: September 2017

During the Ymer-80 expedition, a 6 m long ice core was taken on the low-lying ice cap Storøyjøkulen, Svalbard. Core samples of about 10 ml were filtered on 0.1 μm pore-size Nuclepore filters, for analysis with a soot photometer and by means of particle-induced X-ray emission, which yielded elemental carbon and about 15 metals in the insoluble microparticles. The concentrations

were comparable to Arctic snow data from other locations. Multivariate statistical analysis of the chemical results indicates two major factors affecting microparticle composition: crustal and anthropogenic. A regular seasonal concentration pattern was found which is consistent with the c. 40 cm annual accumulation deduced from mass-balance studies on the ice cap.
X-Ray Structure Analyses of Air Hydrates in a Deep Ice Core from Dye 3, Greenland (Abstract)
Authors: Hondoh T. , Anzai H. , Hayakawa N. , Mae S. , Higashi A. , Langway C.C.
Published: September 2017

Clathrate hydrate inclusions of various shapes and sizes were first found by Shoji and Langway (1982) in ice cores from a depth greater than 1280 m at Dye 3, Greenland. Although we have assigned clathrate guest molecules to O2 and N2 by observing Raman spectra of the hydrates in a core from 1501 m depth (Nakahara and others, in press), it has not been determined whether the crystal structure of the hydrate is structure I or structure II.

Using the 4-circle diffractometer in the High Brilliance X-ray Laboratory at Hokkaido University, many reflections from the hydrate crystals were identified. Applying extinction rules for cubic crystals, the space group of the hydrate was determined as Fd3m, which corresponded to structure II. The average lattice parameter for a unit cell obtained from three samples was 17.21 A, and this also supports structure II. Structure II was also found with artificial air hydrates by the method of neutron diffraction (Davidson and others 1984).

The density of the hydrate was calculated for various combinations of the occupancy of the two types of cage by guest molecules (in a composition ratio of N2 :O2 = (1.5 2.0) : I as determined from Raman intensity). A reasonable value of the density 950 kg m”3 was obtained when only the 12-hedrons were occupied. Therefore it was concluded that the air molecules were trapped only in 12-hedrons which formed the structure II hydrate with 16-hedrons.
Temporal Variations in the Deep Ice-Core Chemistry Record from Dye 3, Greenland (Abstract)
Authors: Langway C.C. , Goto-Azuma K.
Published: September 2017

Measurements of the chemical constituents in polar-snow deposits translate into chronological records representing a history of atmospheric composition for the periods involved. The 2037 m deep continuous and undisturbed ice core recovered at Dye 3, Greenland between 1979 and 1981 contains a temporal record of sequential snow deposits for the past 9 × 104 a B.P. (Dansgaard and others 1985). The upper 90 m of the deep core were unsuitable for chemistry studies, but stratigraphic continuity with present-day accumulation was obtained by hand-excavating a 5.4 m deep pit and augering two shallow cores to 138 and 113 m depths. The pit and shallow cores represent the last two centuries of snow precipitation.

To date, over 6000 individual samples of the pit, shallow and deep ice cores have been measured by ion chromatography for Cl−, NO3−, and SO42− in the field and laboratory (Herron and Langway 1985, Finkel and Langway 1985, Finkel and others 1986), under clean-room conditions. All pit and shallow-core samples were prepared in a continuous sequence of eight samples per year, as identified by other stable and radioactive isotope-dating methods. The deep ice-core samples were selected and prepared from core intervals spaced over the 2037 m profile from time units which showed evidence of abrupt or transitory periods in climate change or volcanic disturbances, as defined by stable isotopes (Dansgaard and others 1985), atmospheric gases (Oeschger and others 1985) and dust (Hammer and others 1985).

Approximately 1700 new measurements from the Dye 3 samples are included in this study. Variability in the chemical constituents and their concentration levels is present and meaningful on a short-term and long-term basis. The time units measured represent seasons, years, decades, centuries and longer geological periods. Particular attention is given to two new high- and low-frequency detailed chronological data sets from (1) a continuous 26 m core profile, representing 3000 years, extending from the Holocene/Wisconsin boundary back into the late Wisconsin and (2) measurements made on 106 samples spaced every 2 m over the Wisconsin-age ice from 1786 to 2008 m.
Dielectric Properties of Deep Ice Cores with Air-Hydrate Inclusions (Abstract)
Authors: Mae Shinji , Hondoh Takeo , Nakawo Masayoshi , Langway C.C.
Published: September 2017

Air-hydrate inclusions have been found in deep ice cores from Dye 3, Greenland, which were taken in August 1981. Although the concentration of the air-hydrate crystals decreased with time, when the core was stored at a temperature of −50 °C, they still existed to an appreciable extent in 1985.

An ice specimen was cut out from the Dye 3 core at a depth of 1500 m, where the volume fraction of the hydrate crystals was about 10−3 by volume. Its dielectric properties were measured in September 1985, in a frequency range of 30-20 × 103 Hz and temperature range of −20° to −90°C. The activation energy obtained for the relaxation time of the Debye dispersion was about 0.2 eV, which is much smaller than that of pure ice.

The measurement was repeated once a month for about a year, and the sample was stored at a temperature of −10 °C between measurements. The time variation of the dielectric properties has been discussed in relation to the deterioration of the air-hydrate crystals.
Gas Diffusion and Fractionation in Clathrated Ice-Core Samples (Abstract)
Authors: Ocampo J.
Published: September 2017

The evolution of gas content from clathrated ice is very sensitive to pressure and to storage temperature. As such substances are likely to be found in deep Antarctic ice and the Greenland ice sheet (Miller 1969, Shoji and Langway 1982), the influence of clathrate formation and incomplete back-diffusion on the measured air composition was investigated.

We have undertaken laboratory studies on the kinetics of formation and decomposition of clathrate hydrates of air and carbon dioxide. The kinetics were found to be controlled mainly by the self-diffusion of water molecules. The clathrate structure being of type II (Davidson and others 1984), the diffusion of guest molecules and the role of auxiliary gases was studied.

A bubble-relaxation model is presented for air-hydrate inclusions in fresh ice cores. It takes into account the diffusion constant for desorption of clathrates and the mechanical relaxation of the bulk ice. The increasing pressure and the initially low bubble surface are factors which limit the rate of decomposition. The rate of decomposition was compared with the natural bubble relaxation measured in deep ice cores (Gow and Williamson 1975).

Fractionation was also observed through the formation and decomposition of mixed hydrates. The diffusion control of the recrystallization process affects this fractionation.

On the basis of this study we make some recommendations for the analysis of deep ice-core samples.
N2O Measurements on Air Extracted from Antarctic Ice Cores (Abstract)
Authors: Zardini D. , Raynaud D. , Scharffe D. , Seiler W.
Published: September 2017

A method has been developed for measuring N2O concentrations in the air extracted from the bubbles contained in ice cores. The air extraction is performed by cutting the ice into very small pieces with a rotating knife, in a controlled atmosphere. The N2O concentrations are measured by gas chromatography. The complete original procedure will be discussed, and the results of the different experimental tests given, with a discussion of the uncertainties.

This method has been used to perform about 40 measurements on Antarctic ice samples. Ten air samples from the D57 core date approximately from the beginning of the seventeenth and twentieth centuries. The others were taken from the Dome C core and date from the Holocene and the period around the Last Glacial Maximum. The D57 results are in agreement with those of Pearman and others (1986), leading to a similar pre-industrial N2O level (270-290 ppb volume). Furthermore, our Dome C results suggest that during the Last Glacial Maximum atmospheric N2O content was not drastically different from the recent period.
Substring search over encrypted data
Authors: Moataz Tarik , Ray Indrajit , Ray Indrakshi , Shikfa Abdullatif , Cuppens Frédéric , Cuppens Nora
Published: September 2017

We propose a general solution to the problem of efficient substring search over encrypted data. The solution enhances existing “keyword” searchable encryption schemes by allowing searching for any part of encrypted keywords without requiring one to store all possible combinations of substrings from a given dictionary. The proposed technique is based on the idea of letter orthogonalization that allows testing of string membership by performing efficient inner products. We first propose SED-1, the base protocol for substring search. We then identify some attacks on SED-1 that demonstrate the complexity of the substring search problem under different threat scenarios. This leads us to propose our second and main protocol SED-2. The protocol is also efficient in that the search complexity is linear in the size of the keyword dictionary. We run several experiments on a sizeable real world dataset to evaluate the performance of our protocol.
Establishing a Risk Profile for New Zealand Pastoral Farms
Authors: Grafton Miles , Manning Michael
Published: September 2017

In this paper, the risk profile of two pastoral production systems in New Zealand are examined. All farmers must manage and mitigate a multitude of risks. Traditionally, a farm budget is solely undertaken to satisfy a lending institution. Limited variance analysis takes place, usually for output prices and inputs such as: interest rates, energy costs, and fertiliser. The authors of this paper use “@Risk”, a risk profiling plug-in tool for Microsoft Excel to demonstrate how farm budgets can be more relevant to farmers. Many risk factors that affect farm financial performance, such as climate and commodity prices, are not controlled by the farmer. Wet summers help hill country sheep and beef pastoral farmers, as more grass growth occurs, which thereby reduces the cost of production and increases revenue, as more stock is finished. Whereas in drought years income falls as stock must be sold prior to finishing, in severe droughts capital stock may also be sold. Input costs also rise as pasture weed invasion occurs; health issues such as rye grass staggers may also add cost. Monte Carlo simulations on model farm budgets for a North Island sheep and beef property and a Canterbury dairy farm help demonstrate the risk profile of each farm type.
New Chaotic Dynamical System with a Conic-Shaped Equilibrium Located on the Plane Structure
Authors: Petrzela Jiri , Gotthans Tomas
Published: September 2017

This paper presents a new autonomous deterministic dynamical system with equilibrium degenerated into a plane-oriented hyperbolic geometrical structure. It is demonstrated via numerical analysis and laboratory experiments that the discovered system has both a structurally stable strange attractor and experimentally measurable chaotic behavior. It is shown that the evolution of complex dynamics can be associated with a single parameter of a mathematical model and, due to one-to-one correspondence, to a single circuit parameter. Two-dimensional high resolution plots of the largest Lyapunov exponent and basins of attraction expressed in terms of final state energy are calculated and put into the context of the discovered third-order mathematical model and real chaotic oscillator. Both voltage- and current-mode analog chaotic oscillators are presented and verified by visualization of the typical chaotic attractor in a different fashion.
Film Thickness Estimation for the Oil Applied to the Inner Surface of Slim Tubes
Authors: Svetlík Jozef , Buša Ján , Brestovič Tomáš , Dobránsky Jozef , Kráľ Ján
Published: September 2017

The article deals with the approximation of the results of experimental measurement of coating of the inner surface of slim pipes with special oil, using a dispersion oil fraction. The reason for such treatment of the inner surface of the tubes is the anti-corrosion protection or various other requirements. The oil manufacturer prescribes the minimum required layer to guarantee the anti-corrosion protection parameters. Therefore, it is advisable to know the most exact coating parameters for different pipe diameters. The measured results give us an assumption of how much oil is sufficient to coat the inside of a pipe. The main idea lies in the correct estimation of coefficients in the three-parameter exponential dependence. For the initial estimates, Nelder–Mead’s minimization method was used. The condition for meeting the lower estimate of the minimum thickness of the oil layer was determined. Following graphic processing of minimization of individual pipe diameters, in some cases, the coefficients were adjusted manually. The result is that the oil thickness depends on the distance of the investigated point from the beginning of the tube, or on the point of entry of the dispersion oil fraction.
CEPP: Perceiving the Emotional State of the User Based on Body Posture
Authors: Lee Suk , Bae Mungyu , Lee Woonghee , Kim Hwangnam
Published: September 2017

Much research has been conducted in the area of face and gesture recognition in order to classify one’s emotional state. Surprisingly, utilizing computerized algorithms which recognize emotional conditions based on body postures has not yet been systematically developed. In this paper, we propose a novel method, Computerized Emotion Perception based on Posture (CEPP), to determine the emotional state of the user. This method extracts features from body postures and estimates the emotional state by computing a similarity distance. With the proposed algorithm, we will provide new insights into automatically recognizing one’s emotional state.
3D-Printed Super-Wideband Spidron Fractal Cube Antenna with Laminated Copper
Authors: Kwon Oh , Park Won , Lee Sungwoo , Lee Jong , Park Young , Hwang Keum
Published: September 2017

In this paper, a 3D-printed super-wideband (SWB) Spidron fractal cube antenna is proposed. The Spidron fractal configuration is utilized as a self-complementary structure on each face of a 3D frame to attain SWB characteristics. The antenna is excited through a tapered microstrip balun for both mode transforming and impedance matching. A prototype of the proposed antenna, including the 3D frame fabricated with the help of a 3D printer and Spidron fractal patches made of copper tape, is experimentally verified. The measured −10 dB reflection ratio bandwidth is 34:1 (0.44–15.38 GHz). The peak gain varies from 3.42 to 9.29 dBi within the operating frequency bandwidth. The measured radiation patterns are nearly omnidirectional at all operating frequency bands.
Empirical Subseasonal Prediction of Summer Rainfall Anomalies over the Middle and Lower Reaches of the Yangtze River Basin Based on Atmospheric Intraseasonal Oscillation
Authors: Zhu Zhiwei , Chen Shengjie , Yuan Kai , Chen Yini , Gao Song , Hua Zhenfei
Published: September 2017

The middle and lower reaches of the Yangtze River basin (MLRYB) are prone to flooding because their orientation is parallel to the East Asian summer monsoon rain belt. Since the East Asian summer monsoon presents pronounced intraseasonal variability, the subseasonal prediction of summer precipitation anomalies in the MLRYB region is an imperative demand nationwide. Based on rotated empirical orthogonal function analysis, 48 stations over the MLRYB with coherent intraseasonal (10–80-day) rainfall variability are identified. Power spectrum analysis of the MLRYB rainfall index, defined as the 48-station-averaged intraseasonal rainfall anomaly, presents two dominant modes with periods of 20–30 days and 40–60 days, respectively. Therefore, the intraseasonal (10–80-day) rainfall variability is divided into 10–30-day and 30–80-day components, and their predictability sources are detected separately. Spatial-temporal projection models (STPM) are then conducted using these predictability sources. The forecast skill during the period 2003–2010 indicates that the STPM is able to capture the 30–80-day rainfall anomalies 5–30 days in advance, but unable to reproduce the 10–30-day rainfall anomalies over MLRYB. The year-to-year fluctuation in forecast skill might be related to the tropical Pacific sea surface temperature anomalies. High forecasting skill tends to appear after a strong El Niño or strong La Niña when the summer seasonal mean rainfall over the MLRYB is enhanced, whereas low skill is apparent after neutral conditions or a weak La Niña when the MLRYB summer seasonal mean rainfall is weakened. Given the feasibility of STPM, the application of this technique is recommended in the real-time operational forecasting of MLRYB rainfall anomalies during the summer flooding season.
Why are Functional Amyloids Non-Toxic in Humans?
Authors: Jackson Matthew , Hewitt Eric
Published: September 2017

Amyloids were first identified in association with amyloidoses, human diseases in which proteins and peptides misfold into amyloid fibrils. Subsequent studies have identified an array of functional amyloid fibrils that perform physiological roles in humans. Given the potential for the production of toxic species in amyloid assembly reactions, it is remarkable that cells can produce these functional amyloids without suffering any obvious ill effect. Although the precise mechanisms are unclear, there are a number of ways in which amyloid toxicity may be prevented. These include regulating the level of the amyloidogenic peptides and proteins, minimising the production of prefibrillar oligomers in amyloid assembly reactions, sequestrating amyloids within membrane bound organelles, controlling amyloid assembly by other molecules, and disassembling the fibrils under physiological conditions. Crucially, a better understanding of how toxicity is avoided in the production of functional amyloids may provide insights into the prevention of amyloid toxicity in amyloidoses.
Sleep Disorders in Childhood Neurological Diseases
Authors: Tolaymat Abdullah , Liu Zhao
Published: September 2017

Sleep problems are frequently addressed as a primary or secondary concern during the visit to the pediatric neurology clinic. Sleep disorders can mimic other neurologic diseases (e.g., epilepsy and movement disorders), and this adds challenges to the diagnostic process. Sleep disorders can significantly affect the quality of life and functionality of children in general and those with comorbid neurological diseases in particular. Understanding the pathophysiology of sleep disorders, recognizing the implications of sleep disorder in children with neurologic diseases and behavioral difficulties, and early intervention continue to evolve resulting in better neurocognitive outcomes.
Comparison of Different Solar-Assisted Air Conditioning Systems for Australian Office Buildings
Authors: Ma Yunlong , Saha Suvash , Miller Wendy , Guan Lisa
Published: September 2017

This study has investigated the feasibility of three different solar-assisted air conditioning systems for typical medium-sized office buildings in all eight Australian capital cities using the whole building energy simulation software EnergyPlus. The studied solar cooling systems include: solar desiccant-evaporative cooling (SDEC) system, hybrid solar desiccant-compression cooling (SDCC) system, and solar absorption cooling (SAC) system. A referenced conventional vapor compression variable-air-volume (VAV) system has also been investigated for comparison purpose. The technical, environmental, and economic performances of each solar cooling system have been evaluated in terms of solar fraction (SF), system coefficient of performance (COP), annual HVAC (heating, ventilation, and air conditioning) electricity consumption, annual CO2 emissions reduction, payback period (PBP), and net present value (NPV). The results demonstrate that the SDEC system consumes the least energy in Brisbane and Darwin, achieving 56.9% and 82.1% annual energy savings, respectively, compared to the conventional VAV system, while for the other six cities, the SAC system is the most energy efficient. However, from both energy and economic aspects, the SDEC system is more feasible in Adelaide, Brisbane, Darwin, Melbourne, Perth, and Sydney because of high annual SF and COP, low yearly energy consumption, short PBP and positive NPV, while for Canberra and Hobart, although the SAC system achieves considerable energy savings, it is not economically beneficial due to high initial cost. Therefore, the SDEC system is the most economically beneficial for most of Australian cities, especially in hot and humid climates. The SAC system is also energy efficient, but is not as economic as the SDEC system. However, for Canberra and Hobart, reducing initial cost is the key point to achieve economic feasibility of solar cooling applications.
Relationship between Creep Property and Loading-Rate Dependence of Strength of Artificial Methane-Hydrate-Bearing Toyoura Sand under Triaxial Compression
Authors: Miyazaki Kuniyuki , Tenma Norio , Yamaguchi Tsutomu
Published: September 2017

Methane hydrate is anticipated to be a promising energy resource. It is essential to consider the mechanical properties of a methane hydrate reservoir to ensure sustainable production, since its mechanical behavior may affect the integrity of the production well, the occurrence of geohazards, and gas productivity. In particular, the creep property of methane-hydrate-bearing sediment is thought to have great significance in the long-term prediction of the mechanical behaviors of a reservoir. In earlier studies, triaxial compression tests were conducted on artificial methane-hydrate-bearing Toyoura sand under three axial-loading conditions, i.e., constant-strain-rate test, constant-stress-rate test, and creep (constant-stress) test. In this paper, the time-dependent properties of the methane-hydrate-bearing Toyoura sand observed in these tests were quantitatively discussed and found to be almost in agreement. The creep life obtained from the creep tests had a reasonably strong correlation with the loading-rate dependencies of strength, obtained from the constant-strain-rate tests and constant-stress-rate tests based on a simple hypothesis. The findings are expected to be used to develop a constitutive model considering the time-dependent behaviors of hydrate-bearing soil in future studies, and to improve the reliability of long-term prediction of the geomechanical response to gas extraction from a reservoir.
Engineering Fluid Dynamics
Authors: Hjertager Bjørn
Published: September 2017

Over the last few decades, the use of computational fluid dynamics (CFD) and experimental fluid dynamics (EFD) methods has penetrated into all fields of engineering. [...]
Trends in Data Centre Energy Consumption under the European Code of Conduct for Data Centre Energy Efficiency
Authors: Avgerinou Maria , Bertoldi Paolo , Castellazzi Luca
Published: September 2017

Climate change is recognised as one of the key challenges humankind is facing. The Information and Communication Technology (ICT) sector including data centres generates up to 2% of the global CO2 emissions, a number on par to the aviation sector contribution, and data centres are estimated to have the fastest growing carbon footprint from across the whole ICT sector, mainly due to technological advances such as the cloud computing and the rapid growth of the use of Internet services. There are no recent estimations of the total energy consumption of the European data centre and of their energy efficiency. The aim of this paper is to evaluate, analyse and present the current trends in energy consumption and efficiency in data centres in the European Union using the data submitted by companies participating in the European Code of Conduct for Data Centre Energy Efficiency programme, a voluntary initiative created in 2008 in response to the increasing energy consumption in data centres and the need to reduce the related environmental, economic and energy supply security impacts. The analysis shows that the average Power Usage Effectiveness (PUE) of the facilities participating in the programme is declining year after year. This confirms that voluntary approaches could be effective in addressing climate and energy issue.
Population Spatial Dynamics of Larix potaninii in Alpine Treeline Ecotone in the Eastern Margin of the Tibetan Plateau, China
Authors: Cui Jia’nan , Qin Jihong , Sun Hui
Published: September 2017

The high-altitude treeline is known to be sensitive to climate variability, and is thus considered as a bio-monitoring indicator of climate change. However, our understanding of the population dynamics and the cumulative climate-change effects on the alpine treeline ecotone in recent decades is limited. Here, we investigated the population dynamics of Larix potainii on the south- and north-facing slopes in the alpine treeline ecotone in the eastern margin of the Tibetan Plateau, China, including treeline position, population density, and tree recruitment. Results showed that on both south- and north-facing slopes, the treeline did not show a significant advancement in the past four decades. The population was dominated by young individuals, which tend to be established in the lower areas. Larix, here, tends to be clustered, especially in the upper areas. However, population density increased dramatically only on north-facing slopes. Larix here suffer from the stressful environment, but the warmer winter due to climate warming could facilitate the vertical growth of seedlings and saplings. Aggregated spatial patterns also provide a positive feedback in ameliorating the harsh environment. The slope-climate-moisture interactions have a pronounced impact on tree recruitment, including snow-limited tree establishment on the north-facing slopes and moisture-limited tree establishment on the south-facing slopes.
Comparison of Patterns of Use of Unrecorded and Recorded Spirits: Survey of Adult Drinkers in Rural Central China
Authors: Wei Shiqing , Yin Ping , Newman Ian , Qian Ling , Shell Duane , Yuen Lok-wa
Published: September 2017

About 70% of the beverage alcohol consumed in China annually is spirits. Recorded spirits make up most spirit consumption, but about 25% of total alcohol consumption (1.7 L pure alcohol per capita annually) is unrecorded spirits (bai jiu), either homemade or made in unregulated distilleries. In some parts of China, the consumption of unrecorded spirits is higher than average. This paper compares the patterns of use of unrecorded distilled spirits and recorded distilled spirits among rural residents in Central China. Interviews were conducted with 3298 individuals in 21 towns/villages in 10 counties in the Hubei, Anhui, and Hebei provinces in the People’s Republic of China. Unrecorded bai jiu drinkers chose it because of its taste and its low price. It was consumed mostly by older men, mostly at home with family, more regularly and at higher alcohol by volume (ABV) compared to recorded alcohol. Recorded bai jiu drinkers were more likely to drink away from their homes, consumed more bai jiu at memorable drinking occasions, and reported feeling sick after drinking more often than unrecorded bai jiu drinkers. This comparison of patterns of use of unrecorded bai jiu and recorded bai jiu does not suggest that unrecorded bai jiu is more problematic for drinkers.
Job Satisfaction among Health-Care Staff in Township Health Centers in Rural China: Results from a Latent Class Analysis
Authors: Wang Haipeng , Tang Chengxiang , Zhao Shichao , Meng Qingyue , Liu Xiaoyun
Published: September 2017

Background: The lower job satisfaction of health-care staff will lead to more brain drain, worse work performance, and poorer health-care outcomes. The aim of this study was to identify patterns of job satisfaction among health-care staff in rural China, and to investigate the association between the latent clusters and health-care staff’s personal and professional features; Methods: We selected 12 items of five-point Likert scale questions to measure job satisfaction. A latent-class analysis was performed to identify subgroups based on the items of job satisfaction; Results: Four latent classes of job satisfaction were identified: 8.9% had high job satisfaction, belonging to “satisfied class”; 38.2% had low job satisfaction, named as “unsatisfied class”; 30.5% were categorized into “unsatisfied class with the exception of interpersonal relationships”; 22.4% were identified as “pseudo-satisfied class”, only satisfied with management-oriented items. Low job satisfaction was associated with specialty, training opportunity, and income inequality. Conclusions: The minority of health-care staff belong to the “satisfied class”. Three among four subgroups are not satisfied with income, benefit, training, and career development. Targeting policy interventions should be implemented to improve the items of job satisfaction based on the patterns and health-care staff’s features.
Using a Hidden Markov Model for Improving the Spatial-Temporal Consistency of Time Series Land Cover Classification
Authors: Gong Wenbing , Fang Shenghui , Yang Guang , Ge Mengyu
Published: September 2017

Time series land cover maps play a key role in monitoring the dynamic change of land use. To obtain classification maps with better spatial-temporal consistency and classification accuracy, this study used an algorithm that incorporated information from spatial and temporal neighboring observations in a hidden Markov model (HMM) to improve the time series land cover maps initially produced by a support vector machine (SVM). To investigate the effects of different initial distributions and transition probability matrices on the classification of the HMM, we designed different experimental schemes with different input elements to verify this algorithm with Landsat and HJ satellite images. In addition, we introduced spatial weights into the HMM to make effective use of spatial information. The experimental results showed that the HMM considered that spatial weights could eliminate the vast majority of illogical land cover transition that may occur in previous pixel-wise classification, and that this model had obvious advantages in spatial-temporal consistency and classification accuracy over some existing classification models.
New Insights into the Role of Inflammation in the Pathogenesis of Atherosclerosis
Authors: Wu Meng-Yu , Li Chia-Jung , Hou Ming-Feng , Chu Pei-Yi
Published: September 2017

Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of lipids, smooth muscle cell proliferation, cell apoptosis, necrosis, fibrosis, and local inflammation. Immune and inflammatory responses have significant effects on every phase of atherosclerosis, and increasing evidence shows that immunity plays a more important role in atherosclerosis by tightly regulating its progression. Therefore, understanding the relationship between immune responses and the atherosclerotic microenvironment is extremely important. This article reviews existing knowledge regarding the pathogenesis of immune responses in the atherosclerotic microenvironment, and the immune mechanisms involved in atherosclerosis formation and activation.
A Novel Vav3 Homolog Identified in Lamprey, Lampetra japonica, with Roles in Lipopolysaccharide-Mediated Immune Response
Authors: Shen Yanqi , Zhang Yishan , Han Yinglun , Su Peng , Gou Meng , Pang Yue , Li Qingwei , Liu Xin
Published: September 2017

Vav guanine nucleotide exchange factor 3 (Vav3), a Rho family GTPase, regulates multiple cell signaling pathways including those of T- and B-cell receptors in vertebrates through mediating the activities of the Rho family members. Whether the lamprey possesses Vav3 homolog and what role it plays in immune response remain unknown. Gene cloning, recombinant expression, antibody production and expression pattern analyses were performed to characterize the lamprey Vav3 in the current study. The lamprey Vav3 is closer to jawed vertebrates’ Vav3 molecules (about 53% identities in general) than to Vav2 molecules of jawless and jawed vertebrates (about 51% identities in general) in sequence similarity. Conserved motif analysis showed that the most distinguished parts between Vav3 and Vav2 proteins are their two Src-homology 3 domains. The relative expression levels of lamprey vav3 mRNA and protein were significantly up-regulated in lamprey lymphocytes and supraneural myeloid bodies after mixed-antigens stimulation, respectively. In addition, lamprey Vav3 were up-regulated drastically in lymphocytes and supraneural myeloid bodies after lipopolysaccharide (LPS) rather than phytohemagglutinin (PHA) stimulation. Lamprey Vav3 distributed in the cytoplasm of variable lymphocyte receptor B positive (VLRB+) lymphocytes, and the number of plasmacytes (VLRB and lamprey Vav3 double positive) in blood lymphocytes also increased after LPS stimulation. Our results proved that lamprey Vav3 was involved in the LPS-mediated immune reaction of lamprey and provided a clue for the further study of the precise role lamprey Vav3 played in the signaling pathway of lamprey VLRB+ lymphocytes.