bluuebunny/crossref_metadata_2025 huggingface dataset:
Post-fire macrofungi in the burnt area in the Jelonka reserve (Białowieża region, NE Poland)
Authors: Sumorok Beata
Published: August 2014

In the burnt area of the Jelonka nature reserve near Białowieża Primeval Forest mycological studies were carried out in the years 1994-1999. Carpophores of all macrofungi were identified and counted on 7 permanent observation plots repesenting different successional stages before the fire. Altogether 250 species of macromycetes were found, among them 16 species of post-fire fungi. Pholiota carbonaria and Tephrocybe anthracophila were the most abundant and frequent species occurring in the first years after the fire. It has be~ revealed that the presence of carbonised substrate is a limiting factor for the occurrence of post-fire Basidiomycetes.
Studies on the biology and occurrence of Ampelomyces quisqualis in the Drawski Landscape Park (NW Poland)
Authors: Czerniawska Beata
Published: August 2014

In the years 1996-1998, the ccurrence of Ampelomyces quisqualis parasitizing powdery mildews (Erysiphales) affecting plants of 12 permanent plots with nine plant assciations, as well as those of 32 agricultural fields and gardens of the Drawsko Landscape Park in north-western Poland was investigated. The plant associations of the 12 permanent plots were Luzulo pilosae-Fagetum, Stellrio-Carpinetum, Querco roboris-Pinetum, Leucobryo-Pinetum, Ribo nigri-Alnenun, Circaeo-Alnetum, Vaccino ulginosi-Pinetum, Chenopodietea, and Artemisietea. In the laboratory, the morphology of this hyperparasite, its pattern of colonization of powdery mildews as well as the influence of cultural conditions on its growth and sporulation were determined. Of the 57 species of Erysiphales found in Drawsko Landscape Park, A. quisqualis parasitized 14 in three genera. Of them, nine species were for the first time found to be fungal hosts of A. quisqualis in Poland. This hyperparasite preferred the Artemisietea and Chenopodiatea plant associations, as well as plants of agricultural and horticultural areas, i. e., plants of warmer sites compared with the others considered in this study. The media favouring the growth and sporulation of A. quisqualis were Sabouraud agar and potato dextrose agar. The optimal temperature range for both growth and sporulation of A. quisqualis was 20 -25°C.
Fungal communities of the rhizosphere and the rhizoplane of yellow lupine in a crop rotation system
Authors: Cwalina-Abroziak Bożena , Kurowski Tomasz P.
Published: August 2014

Fungal community populating the rhizosphere and lhe rhizoplane of yellow lupine Juno and Markiz cultivated in the crop rotation with the 20% and 33% portion of lupine was analyzed. The total fungus number was reduced when the participation of lupine in the crop rotation was established at level 20%. Then the pathogenic fungi were replaced by more frequently appeared saprofitic species representing the following genera: Trichoderma, Paecilomyces and Penicillium. Pathogenic Fusarium were more frequently isolated from the lupine rhizoplane cultivated in combination with its 33% participation.
Effect of some saprotrophic soil fungi on the embryonic development of Ascaris suum (Nematoda)
Authors: Kuźna-Grygiel Wanda , Kołodziejczyk Lidia , Janowicz Krystyna , Mazurkiewicz-Zapałowicz Kinga
Published: August 2014

Effect of Penicillium frequentans and Stachybotrys chartorum fungi on the embryonic development of Ascaris suum were studied in the present paper. In eggs that were incubated with fungi, significant delay of initiation of zygote division, as well as retardation of the development of individual stages of embryogenesis, was given a closer insight. Additionally, the following phenomena were observed: vacuolisation of zygote and disturbances in the distribution of yolk, non-synchronous and unequal divisions of blastomere, deformations of the blastula, gastrula, and larval stages. The above changes were more distinct in eggs that were incubated with P. frequentans. In the cultures with P. frequentans, a significantly lower number of larvac, as well as their earlier mortality were observed.
On the occurrence of Sistotrema confluens (Stereales) in Poland
Authors: Piątek Marcin , Cabała Jolanta
Published: August 2014

The new Polish rccord of Sistotrema confluens Pers.: Fr. provides the back-ground to outlining the morphology (with line drawings of microscopie characters), taxonomy and site conditions of this largely neglected polypore in Poland. The new record of the fungus is an 13. in the country but the first one documented by voucher specimens.
Modeling Nontraumatic Aneurysm Evolution, Growth and Rupture
Authors: Tor A. Kwembe  , Ashley M. Sanders
Published: August 2014

We have presented a mathematical model to study the evolution, growth and risk rupture of nontraumatic aneurysms contained within a cylindrical region of blood vessels. Analytical and numerical solutions are studied. Results affirmed that the intra-aneurysmal pressure and bloodstream flow account for the evolution and growth of aneurysms, and we find that an aneurysm may rupture when the ratio of the lateral membrane contraction to longitudinal membrane extension approaches one. Numerical properties of intra-aneurysmal pressure, impact fluid velocity, membrane displacement and the deformed radius with respect to the Poisson ratio, membrane thickness and extensional rigidity are studied. The importance of the findings is rested on the fact that they can be used to improve noninvasive means for predicting aneurysm rupture, and treatment and management decisions after rupture.
The Current State of Validation of Administrative Healthcare Databases in Italy: A Systematic Review
Authors: Abraha Iosief , Orso Massimiliano , Grilli Piero , Cozzolino Francesco , Eusebi Paolo , Casucci Paola , Marchesi Mauro , Luchetta Maria Laura , Fruttini Luisa , Ciappelloni Raoul , Florio Rita De , Giovannini Gianni , Montedori Alessandro
Published: August 2014

Background: Administrative healthcare databases are widely present in Italy. Our aim was to describe the current state of healthcare databases validity in terms of discharge diagnoses (according to the International Classification of Diseases, ICD-9 code) and their output in terms of research.
Methods: A systematic search of electronic databases including Medline and Embase (1995-2013) and of local sources was performed. Inclusion criteria were: healthcare databases in any Italian territory routinely and passively collecting data; medical investigations or procedures at patient level data; the use of a validation process. The quality of studies was evaluated using the STARD criteria. Citations of the included studies were explored using Scopus and Google Scholar.
Results: The search strategy allowed the identification of 16 studies of which 3 were in Italian. Thirteen studies used regional administrative databases from Lombardia, Piemonte, Lazio, Friuli-Venezia Giulia and Veneto. The ICD-9 codes of the following diseases were successfully validated: amyotrophic lateral sclerosis (3 studies in four different regional administrative databases), stroke (3 studies), gastrointestinal bleeding (1 study), thrombocytopenia (1 study), epilepsy (1 study), infection (1 study), chronic obstructive pulmonary disease (1 study), Guillain-Barre syndrome (1 study), and cancer diseases (4 studies). The quality of reporting was variable among the studies. Only 6 administrative databases produced further research related to the validated ICD-9 codes.
Conclusion: Administrative healthcare databases in Italy need an extensive process of validation for multiple diagnostic codes to perform high quality epidemiological and health services research.
Does the Ulnar Nerve Enlarge After Surgical Transposition?
Authors: Vosbikian Michael M. , Tarity T. David , Nazarian Levon N. , Ilyas Asif M.
Published: August 2014

Objectives

The purpose of this study was to test the hypothesis that symptomatic transposed ulnar nerves have a larger average cross‐sectional area (CSA) than symptomatic in situ ulnar nerves.

Methods

We conducted a retrospective review of the charts and sonograms of 68 patients who had failed ulnar nerve transposition compared to 48 patients with cubital tunnel syndrome who had not undergone surgical management. In addition, postoperative sonograms were compared with preoperative studies when available. Failure was defined as persistence or recurrence of symptoms of ulnar neuropathy postoperatively. The cross‐sectional area of the nerve, subjective echogenicity, and residual sites of compression were recorded. Groups were subsequently compared by t tests.

Results

The failed ulnar nerve transposition group showed a mean cross‐sectional area ± SD of 17.26 ± 9.93 mm2, whereas the control group showed a mean cross‐sectional area of 13.45 ± 7.33 mm2. This difference was statistically significant (P= .018). Nontransposed nerves were more likely to have identifiable sites of compression (P< .05). There was a trend toward postoperative enlargement in the 6 patients with available preoperative imaging (P = .17). No difference in subjective echogenicity was found in this analysis.

Conclusions

Patients with failed ulnar nerve transposition show a significantly enlarged cross‐sectional area when compared to symptomatic nerves in situ. Although a specific etiology for this difference cannot be determined, the data suggest that the reference ranges for the cross‐sectional area of the ulnar nerve may need to be revised for those who have undergone surgery.
Inactivation of Escherichia coli and Staphylococcus aureus by Ultrasound
Authors: Sesal Nüzhet Cenk , Kekeç Özge
Published: August 2014

Objectives

The aim of this study was to obtain valuable information about the effect of ultrasonic irradiation with a frequency of 30 kHz frequency and power of 100 W on the inactivation capability of two bacterial groups, namely, Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923, in physiologic water samples.

Methods

Ultrasonic irradiation of bacterial samples with different populations of 5 × 103, 1.5 × 104, and 3 × 104 colony‐forming units/mL was performed at a constant frequency with various treatment times. The specific energy (γ) values were calculated for these different concentrations of E coli and S aureus. The rate constant for ultrasonic inactivation was estimated in the linear region of a plot representing a survival ratio logarithm versus sonication time.

Results

Although a significant death rate for E coli was observed with ultrasound treatment, in contrary to expectations, an increase in S aureus populations was observed.

Conclusions

Considering the widespread use of ultrasound for sterilization of tools and equipment used in hospitals, the results obtained in this study indicate that ultrasonic irradiation is not a suitable method for the elimination of the major hospital pathogen S aureus.
Close coupling of N‐cycling processes expressed in stable isotope data at the redoxcline of the Baltic Sea
Authors: Frey Claudia , Dippner Joachim W. , Voss Maren
Published: August 2014

Over the past decades, the hypoxic state of the central Baltic Sea has deteriorated because of eutrophication, but little is known about the extent to which related factors such as nitrogen removal have been altered. The Baltic Sea is a stratified semi‐enclosed basin with a large, anoxic bottom water mass in its central Gotland Basin and highly active microbial nitrogen transformation processes at the redoxcline, the interface between oxic and anoxic waters. In this study, we identified and quantified the dominant transformation processes of reactive nitrogen by exploiting fine resolution profiles of δ15NNO3, δ18ONO3, and δ15NNH4 through the pelagic redoxcline between 60 and 140 m. Our results showed increasing δ15NNO3 and δ18ONO3 values with decreasing nitrate concentrations, but the associated low apparent isotope effect (ε = ~5‰), as inferred from a closed system Rayleigh model, was not consistent with the high ε (~25‰) characteristic of denitrification in the water column. These findings could be explained by substrate limitation. The observed δ18ONO3:δ15NNO3 ratio of 1.38:1 rather than the usual 1:1 ratio typical for denitrification‐dominated systems could be explained by the occurrence of both nitrification and denitrification. We then developed a numeric reaction‐diffusion model, according to which a realistic denitrification rate of 14 nmol N L−1 d−1 was estimated, and a nitrification rate of 6.6 nmol N L−1 d−1 confirmed. Our study not only demonstrates the value of stable isotope data for investigating nitrogen transformation processes but also highlights that care is needed in interpreting systems with closely coupled processes such as those at ocean redoxclines.
Evidence for lunar true polar wander and a past low‐eccentricity, synchronous lunar orbit
Authors: Keane James Tuttle , Matsuyama Isamu
Published: August 2014

As first noted 200 years ago by Laplace, the Moon's rotational and tidal bulges are significantly larger than expected, given the Moon's present orbital and rotational state. This excess deformation has been ascribed to a fossil figure, frozen in when the Moon was closer to the Earth. However, the observed figure is only consistent with an eccentric and non‐synchronous orbit, contrary to our understanding of the Moon's formation and evolution. Here, we show that lunar mascons and impact basins have a significant contribution to the observed lunar figure. Removing their contribution reveals a misaligned fossil figure consistent with an early epoch of true polar wander (driven by the formation of the South Pole‐Aitken Basin) and an early low‐eccentricity, synchronous lunar orbit. This new self‐consistent model solves a long‐standing problem in planetary science and will inform future studies of the Moon's dynamical evolution and early dynamo.
Further evidence for superterminal raindrops
Authors: Larsen M. L. , Kostinski A. B. , Jameson A. R.
Published: August 2014

A network of optical disdrometers (including laser precipitation monitors and a two‐dimensional video disdrometer) was utilized to determine whether the recent reports of “superterminal” raindrops were spurious results of drop breakup occurring on instrumentation. Results unequivocally show that superterminal raindrops at small (less than 1 mm) sizes are ubiquitous, are measurable over an extended area, and appear in every rain event investigated. No evidence was found to suggest that superterminal drops are the result of drop breakup due to impact with the measurement instrument; thus, if the superterminal drops are the result of drop fragmentation, this fragmentation happens in the ambient atmosphere during all rain events measured in this study. The ubiquity of superterminal drops at small drop sizes raises natural questions regarding rain accumulation estimations, estimates of drop size distributions, and erosion characterization.
MESSENGER observations of Mercury's dayside magnetosphere under extreme solar wind conditions
Authors: Slavin James A. , DiBraccio Gina A. , Gershman Daniel J. , Imber Suzanne M. , Poh Gang Kai , Raines Jim M. , Zurbuchen Thomas H. , Jia Xianzhe , Baker Daniel N. , Glassmeier Karl‐Heinz , Livi Stefano A. , Boardsen Scott A. , Cassidy Timothy A. , Sarantos Menelaos , Sundberg Torbjorn , Masters Adam , Johnson Catherine L. , Winslow Reka M. , Anderson Brian J. , Korth Haje , McNutt Ralph L. , Solomon Sean C.
Published: August 2014

The structure of Mercury's dayside magnetosphere is investigated during three extreme solar wind dynamic pressure events. Two were the result of coronal mass ejections (CMEs), and one was from a high‐speed stream (HSS). The inferred pressures for these events are ~ 45 to 65 nPa. The CME events produced thick, low‐β (where β is the ratio of plasma thermal to magnetic pressure) plasma depletion layers and high reconnection rates of 0.1–0.2, despite small magnetic shear angles across the magnetopause of only 27 to 60°. For one of the CME events, brief, ~ 1–2 s long diamagnetic decreases, which we term cusp plasma filaments, were observed within and adjacent to the cusp. These filaments may map magnetically to flux transfer events at the magnetopause. The HSS event produced a high‐β magnetosheath with no plasma depletion layer and large magnetic shear angles of 148 to 166°, but low reconnection rates of 0.03 to 0.1. These results confirm that magnetic reconnection at Mercury is very intense, and its rate is primarily controlled by plasma β in the adjacent magnetosheath. The distance to the subsolar magnetopause is reduced during these events from its mean of 1.45 Mercury radii (RM) from the planetary magnetic dipole to between 1.03 and 1.12 RM. The shielding provided by induction currents in Mercury's interior, which temporarily increase Mercury's magnetic moment, was negated by reconnection‐driven magnetic flux erosion.
Spatial and temporal variations of diffuse CO2 degassing at El Hierro volcanic system: Relation to the 2011–2012 submarine eruption
Authors: Melián Gladys , Hernández Pedro A. , Padrón Eleazar , Pérez Nemesio M. , Barrancos José , Padilla Germán , Dionis Samara , Rodríguez Fátima , Calvo David , Nolasco Dacil
Published: August 2014

We report herein the results of extensive diffuse CO2 emission surveys performed on El Hierro Island in the period 1998–2012. More than 17,000 measurements of the diffuse CO2 efflux were carried out, most of them during the volcanic unrest period that started in July 2011. Two significant precursory signals based on geochemical and geodetical studies suggest that a magma intrusion processes might have started before 2011 in El Hierro Island. During the preeruptive and eruptive periods, the time series of the diffuse CO2 emission released by the whole island experienced two significant increases. The first started almost 2 weeks before the onset of the submarine eruption, reflecting a clear geochemical anomaly in CO2 emission, most likely due to increasing release of deep‐seated magmatic gases to the surface. The second one, between 24 October and 27 November 2011, started before the most energetic seismic events of the volcanic‐seismic unrest. The data presented here demonstrate that combined continuous monitoring studies and discrete surveys of diffuse CO2 emission provide important information to optimize the early warning system in volcano monitoring programs and to monitor the evolution of an ongoing volcanic eruption, even though it is a submarine eruption.
Imaging along‐strike variations in mechanical properties of the Gofar transform fault, East Pacific Rise
Authors: Froment B. , McGuire J. J. , van der Hilst R. D. , Gouédard P. , Roland E. C. , Zhang H. , Collins J. A.
Published: August 2014

A large part of global plate motion on mid‐ocean ridge transform faults (RTFs) is not accommodated as major earthquakes. When large earthquakes do occur, they often repeat quasiperiodically. We focus here on the high slip rate (∼14 cm/yr) Gofar transform fault on the equatorial East Pacific Rise. This fault is subdivided into patches that slip during Mw 5.5–6 earthquakes every 5 to 6 years. These patches are separated by rupture barriers that accommodate slip through swarms of smaller events and/or aseismic creep. We performed an imaging study to investigate which spatiotemporal variations of the fault zone properties control this segmentation in mechanical behavior and could explain the specific behavior of RTFs at the global scale. We adopt a double‐difference approach in a joint inversion of active air gun shots and microseismicity recorded for 1 year. This data set includes the 2008 Mw 6 Gofar earthquake. The along‐strike P wave velocity structure reveals an abrupt transition between the barrier area, characterized by a damaged fault zone of 10–20% reduced Vp and a nearly intact fault zone in the asperity area. The importance of the strength of the damage zone on the mechanical behavior is supported by the temporal S wave velocity changes which suggest increased damage within the barrier area, during the week preceding the Mw 6 earthquake. Our results support the conclusion that extended highly damaged zones are the key factor in limiting the role of major earthquakes to accommodate plate motion along RTFs.
Rankine models for time‐dependent gravity spreading of terrestrial source flows over subplanar slopes
Authors: Weijermars R. , Dooley T. P. , Jackson M. P. A. , Hudec M. R.
Published: August 2014

Geological mass flows extruding from a point source include mud, lava, and salt issued from subsurface reservoirs and ice from surface feeders. The delivery of the material may occur via a salt stock, a volcanic pipe (for magma and mud flows), or a valley glacier (for ice). All these source flows are commonly skewed by a superposed far‐field velocity vector imposed by the topographic slope and thus develop plumes having a wide range of shapes. The morphological evolution of the perimeter of the plumes (in plan view) can be simulated by varying the key parameters in a simple analytical flow description on the basis of Rankine equations. Our model systematically varies the strength of the point source relative to the downslope far‐field velocity of its expelled mass. The flow lines are critically controlled by the relative speed of the two rates, which can be concisely expressed by the dimensionless Rankine number (Rk, introduced in this study). For steady flows, plume widths can be expressed as a function ofRk. The viscosity of the rock, mud, or lava mass involved in the gravity flow affectsRkand thus the appearance of the plumes. For unsteady source strength,Rkbecomes time dependent and the plume width varies over time. The model flow shapes suggest that the plume shapes of natural gravity flows of terrestrial surface materials (mud, lava, salt, and ice) commonly express fast initial flux of the source, followed by an exponential decline of the source strength. Flows having initially higherRkbut otherwise equal life cycles create broader plumes. Peaks in the source flux due to magmatic pulsing during the eruption cycle can explain the formation of pillow lavas. Rather than instantaneously reaching full strength before declining, some natural source flows start by swelling slowly, leading to the creation of unique plume shapes like a flying saucer.
The emission and scattering of L‐band microwave radiation from rough ocean surfaces and wind speed measurements from the Aquarius sensor
Authors: Meissner Thomas , Wentz Frank J. , Ricciardulli Lucrezia
Published: August 2014

In order to achieve the required accuracy in sea surface salinity (SSS) measurements from L‐band radiometers such as the Aquarius/SAC‐D or SMOS (Soil Moisture and Ocean Salinity) mission, it is crucial to accurately correct the radiation that is emitted from the ocean surface for roughness effects. We derive a geophysical model function (GMF) for the emission and backscatter of L‐band microwave radiation from rough ocean surfaces. The analysis is based on radiometer brightness temperature and scatterometer backscatter observations both taken on board Aquarius. The data are temporally and spatially collocated with wind speeds from WindSat and F17 SSMIS (Special Sensor Microwave Imager Sounder) and wind directions from NCEP (National Center for Environmental Prediction) GDAS (Global Data Assimilation System). This GMF is the basis for retrieval of ocean surface wind speed combining L‐band H‐pol radiometer and HH‐pol scatterometer observations. The accuracy of theses combined passive/active L‐band wind speeds matches those of many other satellite microwave sensors. The L‐band GMF together with the combined passive/active L‐band wind speeds is utilized in the Aquarius SSS retrieval algorithm for the surface roughness correction. We demonstrate that using these L‐band wind speeds instead of NCEP wind speeds leads to a significant improvement in the SSS accuracy. Further improvements in the roughness correction algorithm can be obtained by adding VV‐pol scatterometer measurements and wave height (WH) data into the GMF.
The diurnal salinity cycle in the tropics
Authors: Drushka Kyla , Gille Sarah T. , Sprintall Janet
Published: August 2014

Observations from 35 tropical moorings are used to characterize the diurnal cycle in salinity at 1 m depth. The amplitude of diurnal salinity anomalies is up to 0.01 psu and more typically ∼0.005 psu. Diurnal variations in precipitation and vertical entrainment appear to be the dominant drivers of diurnal salinity variability, with evaporation also contributing. Areas where these processes are strong are expected to have relatively strong salinity cycles: the eastern Atlantic and Pacific equatorial regions, the southwestern Bay of Bengal, the Amazon outflow region, and the Indo‐Pacific warm pool. We hypothesize that salinity anomalies resulting from precipitation and evaporation are initially trapped very near the surface and may not be observed at the 1 m instrument depths until they are mixed downward. As a result, the pattern of diurnal salinity variations is not only dependent on the strength of the forcing terms, but also on the phasing of winds and convective overturning. A comparison of mixed‐layer depth computed with hourly and with daily averaged salinity reveals that diurnal salinity variability can have a significant effect on upper ocean stratification, suggesting that representing diurnal salinity variability could potentially improve air‐sea interaction in climate models. Comparisons between salinity observations from moorings and from the Aquarius satellite (level 2 version 3.0 data) reveal that the typical difference between ascending‐node and descending‐node Aquarius salinity is an order of magnitude greater than the observed diurnal salinity anomalies at 1 m depth.
Storm tracks in the Southern Hemisphere subtropical oceans
Authors: O'Kane T. J. , Matear R. J. , Chamberlain M. A. , Oliver E. C. J. , Holbrook N. J.
Published: August 2014

Ocean storm tracks have previously been associated with the midlatitude western boundary currents (WBCs) and the Antarctic Circumpolar Current (ACC). Here we identify and examine large‐scale baroclinically unstable waves occurring within waveguides associated with potential density gradients in the subtropical regions of the Southern Hemisphere (SH) oceans where the trade winds and westerlies meet and at depths associated with mode water formation. In contrast to the Northern Hemisphere subtropics, the SH pathways are more extensive allowing large‐scale coherent disturbances to communicate information westward from the midlatitudes to the subtropics (South Pacific Ocean) and from the subtropics to the tropics (Indian Ocean). Particular consideration is given to the subtropical South Pacific Ocean as this is a region where resonant interactions between large‐scale Rossby waves and significant topographic features have been reported to occur. Using an ocean general circulation model and a simple potential energy transfer diagnostic, we identify the relevant nonlinearly modified structures comparing their propagation characteristics to planetary Rossby waves calculated using a shallow water model. Although at first appearance baroclinic disturbances resemble planetary Rossby waves, we show they are inherently nonlinear, multiscale and are amplified where topography occurs. The location of the disturbances coincides with regions of high variability in sea surface height observed in satellite altimetry and their speeds closely match the large‐scale coherent westward propagating structures described in the observational literature. Our study provides evidence that, in addition to the midlatitude WBCs and the ACC, significant ocean storm tracks are also manifest in the SH subtropics.
Interannual variability of the eastward current in the western South China Sea associated with the summer Asian monsoon
Authors: Chen Changlin , Wang Guihua
Published: August 2014

The interannual variability of the eastward current in the western South China Sea (SCS) during the summer of 1993–2012 is examined with satellite altimeter data and Regional Ocean Modeling System (ROMS) model output. It is found that the meridional location of the eastward current displays apparent interannual variability. The core of the eastward current shifts between 10.7°N and 17.6°N with a standard deviation of 1.6°. Results from Sverdrup theory and ROMS experiments demonstrate a close dynamic linkage between the north‐south migration of the eastward current and the SCS summer monsoon anomaly on the interannual time scale. When the summer monsoon has southwesterly (northeasterly) anomaly, the eastward current moves southward (northward). With the southward (northward) shift of the eastward current, the summer cold filament in the SCS moves southward (northward) as well.
Precipitation variability over UAE and global SST teleconnections
Authors: Niranjan Kumar K. , Ouarda T. B. M. J.
Published: August 2014

The present study investigates the role of equatorial Pacific sea surface temperatures (SSTs) on the precipitation variability over the United Arab Emirates (UAE) and adjoining Middle East regions. Monthly precipitation data (1981–2011) assembled from rain gauge stations located in the UAE along with other global reanalysis data sets are used to explore the teleconnections. It is observed that statistically significant correlations exist between precipitation over the UAE and the equatorial Pacific and North Atlantic SSTs. Canonical correlation analysis between the monthly winter precipitation and the global SSTs (60°S to 60°N) reveals that the major portion of the precipitation variability is influenced by equatorial Pacific SSTs associated with El Niño–Southern Oscillation (ENSO). The moisture budget analysis reveals the distinct change in the anomalous circulation (cyclonic and anticyclonic) associated with strong convergence and divergence of the moisture flux during the warm and cold phases of ENSO, respectively. Further, the composite analysis of upper troposheric zonal wind shows the equatorward shift (~2° latitude) of subtropical jet stream (STJ) over the Middle East during the warm phase of ENSO affecting the weather in the UAE. The findings suggest that the teleconnection linking ENSO and the precipitation over UAE and adjoining regions is mediated by the response of STJ to Rossby waves.
Atmospheric photochemical reactivity and ozone production at two sites in Hong Kong: Application of a Master Chemical Mechanism–photochemical box model
Authors: Ling Z. H. , Guo H. , Lam S. H. M. , Saunders S. M. , Wang T.
Published: August 2014

A photochemical box model incorporating the Master Chemical Mechanism (v3.2), constrained with a full suite of measurements, was developed to investigate the photochemical reactivity of volatile organic compounds at a semirural site (Mount Tai Mo Shan (TMS)) and an urban site (Tsuen Wan (TW)) in Hong Kong. The levels of ozone (O3) and its precursors, and the magnitudes of the reactivity of O3 precursors, revealed significant differences in the photochemistry at the two sites. Simulated peak hydroperoxyl radical (HO2) mixing ratios were similar at TW and TMS (p = 0.05), while the simulated hydroxyl radical (OH) mixing ratios were much higher at TW (p < 0.05), suggesting different cycling processes between OH and HO2 at the two sites. The higher OH at TW was due to high‐NO mixing ratios, which shifted the HOx (OH + HO2) balance toward OH by the propagation of HO2 and alkyl peroxy radicals (RO2) with NO. HOx production was dominated by O3 photolysis at TMS, but at TW, both HCHO and O3 photolyses were found to be major contributors. By contrast, radical‐radical reactions governed HOx radical losses at TMS, while at TW, the OH + NO2 reaction was found to dominate in the morning and the radical‐radical reactions at noon. Overall, the conversion of NO to NO2 by HO2 dictated the O3 production at the two sites, while O3 destruction was dominated by the OH + NO2 reaction at TW, and at TMS, O3 photolysis and the O3 + HO2 reaction were the major mechanisms. The longer OH chain length at TMS indicated that more O3 was produced for each radical that was generated at this site.
Exner‐Based Master Equation for transport and dispersion of river pebble tracers: Derivation, asymptotic forms, and quantification of nonlocal vertical dispersion
Authors: Pelosi A. , Parker G. , Schumer R. , Ma H.‐B.
Published: August 2014

Ideas deriving from the standard formulation for continuous time random walk (CTRW) based on the Montroll‐Weiss Master Equation (ME) have been recently applied to transport and diffusion of river tracer pebbles. CTRW, accompanied by appropriate probability density functions (PDFs) for walker step length and waiting time, yields asymptotically the standard advection‐diffusion equation (ADE) for thin‐tailed PDFs and the fractional advection‐diffusion equation (fADE) for heavy‐tailed PDFs, the latter allowing the possibilities of subdiffusion or superdiffusion. Here we show that the CTRW ME is inappropriate for river pebbles moving as bed load: a deposited particle raises local bed elevation, and an entrained particle lowers it so that particles interact with the “lattice” of the sediment‐water interface. We use the Parker‐Paola‐Leclair framework, which is a probabilistic formulation of the Exner equation of sediment conservation, to develop a new ME for tracer transport and dispersion for alluvial morphodynamics. The formulation is based on the existence of a mean bed elevation averaged over fluctuations. The new ME yields asymptotic forms for ADE and fADE that differ significantly from CTRW. It allows vertical as well as streamwise advection‐diffusion. Vertical dispersion is nonlocal but cannot be expressed with fractional derivatives. In order to illustrate the new model, we apply it to the restricted case of vertical dispersion only, with both thin and heavy tails for relevant PDFs. Vertical dispersion shows a subdiffusive behavior.
Inversion of fluvial channels for paleorock uplift rates in Taiwan
Authors: Fox Matthew , Goren Liran , May Dave A. , Willett Sean D.
Published: August 2014

The transient response of erosion to changes in rock uplift rate leads to the preservation of rock uplift history in the long profiles of rivers. However, extracting this information is nontrivial as changes in channel steepness are the result of both spatial and temporal changes in rock uplift rate, as well as other factors such as climate and rock type. We exploit an analytical linear solution for river channel profile evolution in response to erosion and tectonic uplift to investigate the rock uplift history of Taiwan. The analytical approach allows us to solve the linear inverse problem, efficiently extracting rock uplift as a function of space and time, from digital elevation data. We assess the potential of fluvial topography to resolve rock uplift rates using three approaches: (1) a synthetic resolution test, (2) analysis of the forward model to demonstrate where in space and time the fluvial topography constrains rock uplift rate, and (3) interpretation of the model resolution matrix. Furthermore, the potential to analyze large data sets reduces the influence of stochastic processes such as landslides, small‐scale river network reorganization, and also local lithological variability. In Taiwan, our analysis suggests that current rock uplift rates exceed erosion rates across much of the island and that there has been an increase in rock uplift rates since 0.5 Ma across the Central Range.
A 3‐D thermal regime model suitable for cold accumulation zones of polythermal mountain glaciers
Authors: Gilbert A. , Gagliardini O. , Vincent C. , Wagnon P.
Published: August 2014

Analysis of the thermal and mechanical response of high altitude glaciers to climate change is crucial to assess future glacier hazards associated with thermal regime changes. This paper presents a new fully thermo‐mechanically coupled transient thermal regime model including enthalpy transport, firn densification, full‐Stokes porous flow, free surface evolution, strain heating, surface meltwater percolation, and refreezing. The model is forced by daily air temperature data and can therefore be used to perform prognostic simulations for different future climate scenarios. The set of equations is solved using the finite element ice sheet/ice flow model Elmer/Ice. This model is applied to the Col du Dôme glacier (Mont Blanc area, 4250 m a.s.l., France) where a comprehensive data set is available. The results show that the model is capable of reproducing observed density and velocity fields as well as borehole temperature evolution. The strong spatial variability of englacial temperature change observed at Col du Dôme is well reproduced. This spatial variability is mainly a result of the variability of the slope aspect of the glacier surface and snow accumulation. Results support the use of this model to study the influence of climate change on cold accumulation zones, in particular to estimate where and under what conditions glaciers will become temperate in the future.
Beyond optimality: Multistakeholder robustness tradeoffs for regional water portfolio planning under deep uncertainty
Authors: Herman Jonathan D. , Zeff Harrison B. , Reed Patrick M. , Characklis Gregory W.
Published: August 2014

While optimality is a foundational mathematical concept in water resources planning and management, “optimal” solutions may be vulnerable to failure if deeply uncertain future conditions deviate from those assumed during optimization. These vulnerabilities may produce severely asymmetric impacts across a region, making it vital to evaluate the robustness of management strategies as well as their impacts for regional stakeholders. In this study, we contribute a multistakeholder many‐objective robust decision making (MORDM) framework that blends many‐objective search and uncertainty analysis tools to discover key tradeoffs between water supply alternatives and their robustness to deep uncertainties (e.g., population pressures, climate change, and financial risks). The proposed framework is demonstrated for four interconnected water utilities representing major stakeholders in the “Research Triangle” region of North Carolina, U.S. The utilities supply well over one million customers and have the ability to collectively manage drought via transfer agreements and shared infrastructure. We show that water portfolios for this region that compose optimal tradeoffs (i.e., Pareto‐approximate solutions) under expected future conditions may suffer significantly degraded performance with only modest changes in deeply uncertain hydrologic and economic factors. We then use the Patient Rule Induction Method (PRIM) to identify which uncertain factors drive the individual and collective vulnerabilities for the four cooperating utilities. Our framework identifies key stakeholder dependencies and robustness tradeoffs associated with cooperative regional planning, which are critical to understanding the tensions between individual versus regional water supply goals. Cooperative demand management was found to be the key factor controlling the robustness of regional water supply planning, dominating other hydroclimatic and economic uncertainties through the 2025 planning horizon. Results suggest that a modest reduction in the projected rate of demand growth (from approximately 3% per year to 2.4%) will substantially improve the utilities' robustness to future uncertainty and reduce the potential for regional tensions. The proposed multistakeholder MORDM framework offers critical insights into the risks and challenges posed by rising water demands and hydrological uncertainties, providing a planning template for regions now forced to confront rapidly evolving water scarcity risks.
An intercomparison of statistical downscaling methods used for water resource assessments in the United States
Authors: Gutmann Ethan , Pruitt Tom , Clark Martyn P. , Brekke Levi , Arnold Jeffrey R. , Raff David A. , Rasmussen Roy M.
Published: August 2014

Information relevant for most hydrologic applications cannot be obtained directly from the native‐scale outputs of climate models. As a result the climate model output must be downscaled, often using statistical methods. The plethora of statistical downscaling methods requires end‐users to make a selection. This work is intended to provide end‐users with aid in making an informed selection. We assess four commonly used statistical downscaling methods: daily and monthly disaggregated‐to‐daily Bias Corrected Spatial Disaggregation (BCSDd, BCSDm), Asynchronous Regression (AR), and Bias Corrected Constructed Analog (BCCA) as applied to a continental‐scale domain and a regional domain (BCCAr). These methods are applied to the NCEP/NCAR Reanalysis, as a surrogate for a climate model, to downscale precipitation to a 12 km gridded observation data set. Skill is evaluated by comparing precipitation at daily, monthly, and annual temporal resolutions at individual grid cells and at aggregated scales. BCSDd and the BCCA methods overestimate wet day fraction, and underestimate extreme events. The AR method reproduces extreme events and wet day fraction well at the grid‐cell scale, but over (under) estimates extreme events (wet day fraction) at aggregated scales. BCSDm reproduces extreme events and wet day fractions well at all space and time scales, but is limited to rescaling current weather patterns. In addition, we analyze the choice of calibration data set by looking at both a 12 km and a 6 km observational data set; the 6 km observed data set has more wet days and smaller extreme events than the 12 km product, the opposite of expected scaling.
A Comparative Study on Humidity Sensing Performances of Polyaniline and Polypyrrole Nanostructures
Authors: Joulazadeh Mehrnaz , Navarchian Amir H. , Niroomand Mehdi
Published: August 2014

This paper addresses the preparation of polyaniline (PAni) and polypyrrole (PPy) nanostructures as humidity sensor elements. The semicrystalline microstructure and chemical structure of synthesized PAni and PPy were studied by X‐ray diffraction and Fourier transform infrared spectroscopy, respectively. The morphology of these polymers was studied by scanning electron microscopy and transmission electron microscopy, indicating fibrillar and tubular nanostructures for PAni and PPy, respectively. The humidity sensing performances of sensors based on the prepared nanostructural PAni and PPy were investigated, and the sensing mechanisms of both systems have been discussed. The interesting reverse behaviors during humidity exposure of PAni‐ and PPy‐based sensors in different water vapor concentrations have been comprehensively justified. The temperature dependency of the electrical conductivity for PAni and PPy samples was investigated. The UV–vis spectroscopy was used to study the effect of moisture on the electronic transport properties of PAni and PPy nanostructures.
High thermal conductive m‐xylylenediamine functionalized multiwall carbon nanotubes/epoxy resin composites
Authors: Xie Fan , Qi Shuhua , Yang Rui , Wu Dong
Published: August 2014

In this study, multiwall carbon nanotubes (MWNTs) functionalized by m‐xylylenediamine is used as thermal conductive fillers to improve their dispersibility in epoxy resin and the thermal conductivity of the MWNTs/bisphenol‐A glycidol ether epoxy resin composites. Functionalization with amine groups of MWNTs is achieved after such steps as carboxylation, acylation and amidation. The thermal conductivity, impact strength, flexural strength, and fracture surfaces of MWNTs/epoxy composites are investigated with different MWNTs. The results show that m‐xylylenediamine is successfully grafted onto the surface of the MWNTs and the mass fraction of the organic molecules grafted onto MWNTs is about 20 wt %. The thermal conductivity of MWNTs/epoxy composites is further enhanced to 1.236 W/mK with 2 wt % m‐MWNTs. When the content of m‐MWNTs is 1.5 wt %, the impact strength and flexural strength of the composites are 25.85 KJ/m2, 128.1 MPa, respectively. Scanning electron microscope (SEM) results show that the fracture pattern of composites is changed from brittle fracture to ductile fracture. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41255.
Monitoring production process of cisplatin‐loaded PLGA nanoparticles by FT‐IR microspectroscopy and univariate data analysis
Authors: Portaccio Marianna , Menale Ciro , Diano Nadia , Serri Carla , Mita Damiano G. , Lepore Maria
Published: August 2014

Cisplatin‐loaded PLGA nanoparticles for drug delivery have been prepared using a well‐established water/oil/water double emulsion‐solvent evaporation method. The production process has been monitored by using Fourier Transform Infrared (FT‐IR) microspectroscopy without using KBr tablets and any preliminary sample preparation. Significant spectra have been obtained for all chemical compounds and for samples at different steps of production process. The use of a linear or univariate approach using a R2 determination coefficient has been proposed for discriminating among FT‐IR spectra even when small differences are present. The obtained results confirm that new geometries of data acquisition contribute to make infrared microspectroscopy a very useful tool for a rapid and detailed monitoring of production processes of pharmacological interest. Moreover, morphological and physiological characterizations have been performed on cisplatin‐loded samples showing results in good agreement with those reported in literature. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41305.
Modification of polysulfones by click chemistry: Zwitterionic graft complex and their antiprotein fouling property
Authors: Xu Canhong , Gu Shaojin , Huang Jingjing , Xu Weilin , Xia Huan , Du Jiehao , Liu Hongtao , Yang Hongjun , Zhou Yingshan , Bai Zikui
Published: August 2014

A new nonspecific protein antifouling polysulfone (PSU) material has been elaborated by grafting zwitterionic sulfobetaine (SB) complex by the means of PSU azidation (PSU‐N3) followed by “Click‐Chemistry” with acetylenic zwitterionic SB monomer (N,N'‐diethyl‐N‐propargyl‐N‐ (3‐sulfopropyl) ammonium (DEPAS)). Azidation (PSU‐N3) and functionalization (PSU‐g‐DEPAS) PSU materials were characterized by 1H NMR, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Contact angle and protein adsorption on PSU‐g‐DEPAS and unmodified PSU membrane were studied. The results show that the chemical modification of PSU improved both the hydrophilicity and antiprotein absorption ability. This new fouling‐resistance to protein material has potential for biomaterials applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41327.
Electrospray preparation of propranolol‐loaded alginate beads: Effect of matrix reinforcement on loading and release profile
Authors: Khorram Mohammad , Samimi Mohsen , Samimi Abdolreza , Moghadam Hamid
Published: August 2014

In the present study, propranolol loaded‐calcium alginate beads were prepared from concentrated solutions of sodium alginate, using combined method of electrospray and ionotropic gelation. The objectives of the study were to increase the propranolol‐HCl loading and to decrease its initial burst release. However, the effects of voltage, nozzle diameter, flow rate, and concentration of sodium alginate on size of the beads and drug entrapment efficiency (DEE) were also investigated. The matrix of alginate beads was reinforced with dextran sulfate and/or coated with chitosan. The mean particle size of the beads, their swelling behavior, and drug entrapment efficiency were characterized. Furthermore, the drug release profiles from the prepared beads in simulated gastric fluid and intestinal fluid were evaluated and compared. Among the parameters that affected the electrospray of alginate, voltage had a pronounced effect on the size of beads. The size of beads was reduced to a minimum value on increasing the voltage. Furthermore, increasing the flow rate, alginate concentration, and nozzle diameter and decreasing the voltage led to improvement in DEE. Enhancing the alginate concentration as well as coating with chitosan and reinforcing with dextran sulfate led to increase of the encapsulation efficiency and therefore decrease of the drug release rate in both pHs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41334.