bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasma Brain Natriuretic Peptide (BNP) as an Indicator of Left Ventricular Function, Early Outcome and Mechanical Complications after Acute Myocardial Infarction
Authors: Fazlinezhad A. , Rezaeian M. Khadem , Yousefzadeh H. , Ghaffarzadegan K. , Khajedaluee M.
Published: August 2011

Aims

This study investigated the prognostic value of B type natriuretic peptide (BNP) in acute myocardial infarction (AMI) patients and its relation with left ventricular function and post-myocardial infarction complications.

Methods

In this cross-sectional study, plasma BNP level was measured for 42 consecutive patients (mean ± SD: 61.6 ± 10.85 years old) with acute ST elevation myocardial infarction (MI) and 42 healthy, age and gender matched subjects.

Result

BNP level in AMI patients were significantly higher than control group (@ P < 0.001). Regarding to infarct location, the highest BNP level measured in inferoposterior MI (BNP = 4436.63 ± 6188.159 pg/ml) and the lowest one indicated in standalone inferior MI (BNP = 598.83 ± 309.867 pg/ml ( P = 0.071). There was significant reverse relation between BNP and EF ( P = 0.006, OR = −0.47) and a significant relationship between BNP and killip classification ( P = 0.036). There was no significant relation between diastolic and right-ventricular function and BNP level ( P = 0.61, P = 0.21). The highest BNP level was detected in LV septal rupture and false aneurysm ( P = 0.02) and in ventricular tachycardia, but without significant relationship ( P = 0.25).

Conclusion

After the onset of AMI, BNP blood level can be used as an important predictor for left ventricular dysfunction, killip classification, early mechanical complications and cardiac death.
Nonvanishing of L-functions, the Ramanujan Conjecture, and Families of Hecke Characters
Authors: Blomer Valentin , Brumley Farrell
Published: August 2011

We prove a nonvanishing result for families of GLn× GLn Rankin–Selberg L-functions in the critical strip, as one factor runs over twists by Hecke characters. As an application, we simplify the proof, due to Luo, Rudnick, and Sarnak, of the best known bounds towards the Generalized Ramanujan Conjecture at the infinite places for cusp forms on GLn. A key ingredient is the regularization of the units in residue classes by the use of an Arakelov ray class group.
Note on Cubature Formulae and Designs Obtained from Group Orbits
Authors: Nozaki Hiroshi , Sawa Masanori
Published: August 2011

In 1960, Sobolev proved that for a finite reflection group G, a G-invariant cubature formula is of degree t if and only if it is exact for all G-invariant polynomials of degree at most t . In this paper, we make some observations on invariant cubature formulas and Euclidean designs in connection with the Sobolev theorem. First, we give an alternative proof of theorems by Xu (1998) on necessary and sufficient conditions for the existence of cubature formulas with some strong symmetry. The new proof is shorter and simpler compared to the original one by Xu, and, moreover, gives a general interpretation of the analytically-written conditions of Xu's theorems. Second, we extend a theorem by Neumaier and Seidel (1988) on Euclidean designs to invariant Euclidean designs, and thereby classify tight Euclidean designs obtained from unions of the orbits of the corner vectors. This result generalizes a theorem of Bajnok (2007), which classifies tight Euclidean designs invariant under the Weyl group of type B, to other finite reflection groups.
The Central Limit Theorem for Subsequences in Probabilistic Number Theory
Authors: Aistleitner Christoph , Elsholtz Christian
Published: August 2011

Let (nk)k≥1 be an increasing sequence of positive integers, and let f (x) be a real function satisfying

If the distribution of

converges to a Gaussian distribution. In the case

there is a complex interplay between the analytic properties of the function f , the number-theoretic properties of (nk)k≥1, and the limit distribution of (2).

In this paper we prove that any sequence (nk)k≥1 satisfying lim contains a nontrivial subsequence (mk)k≥1 such that for any function satisfying (1) the distribution of

converges to a Gaussian distribution. This result is best possible: for any ε > 0 there exists a sequence (nk)k≥1 satisfying lim such that for every nontrivial subsequence (mk)k≥1 of (nk)k≥1 the distribution of (2) does not converge to a Gaussian distribution for some f.

Our result can be viewed as a Ramsey type result: a sufficiently dense increasing integer sequence contains a subsequence having a certain requested number-theoretic property.
p-adic L-functions and the Rationality of Darmon Cycles
Authors: Seveso Marco Adamo
Published: August 2011

Darmon cycles are a higher weight analogue of Stark–Heegner points. They yield local cohomology classes in the Deligne representation associated with a cuspidal form on Γ0(N) of even weight k0 ≥ 2. They are conjectured to be the restriction of global cohomology classes in the Bloch–Kato Selmer group defined over narrow ring class fields attached to a real quadratic field. We show that suitable linear combinations of them obtained by genus characters satisfy these conjectures. We also prove p-adic Gross–Zagier type formulas, relating the derivatives of p-adic L-functions of the weight variable attached to imaginary (resp. real) quadratic fields to Heegner cycles (resp. Darmon cycles). Finally we express the second derivative of the Mazur– Kitagawa p-adic L-function of the weight variable in terms of a global cycle defined over a quadratic extension of ℚ.
A Cohomological Property of π-invariant Elements
Authors: Filali M. , Sangani Monfared M.
Published: August 2011

Let A be a Banach algebra and let be a continuous representation of A on a separable Hilbert space H with dim H = m. Let πi j be the coordinate functions of π with respect to an orthonormal basis and suppose that for each and . Under these conditions, we call an element left π-invariant if In this paper we prove a link between the existence of left π-invariant elements and the vanishing of certain Hochschild cohomology groups of A. Our results extend an earlier result by Lau on F-algebras and recent results of Kaniuth, Lau, Pym, and and the second author in the special case where π : A → C is a non-zero character on A.
On Automorphisms and Commutativity in Semiprime Rings
Authors: Liau Pao-Kuei , Liu Cheng-Kai
Published: August 2011

Let R be a semiprime ring with center Z(R). For x, y ∊ R, we denote by [x, y] = xy – yx the commutator of x and y. If σ is a non-identity automorphism of R such that

for all x ∊ R, where n0, n1, n2, … nk are fixed positive integers, then there exists a map μ: R → Z(R) such that σ(x) = x + μ(x) for all x ∊ R. In particular, when R is a prime ring, R is commutative.
Versions of Schwarz's Lemma for Condenser Capacity and Inner Radius
Authors: Betsakos Dimitrios , Pouliasis Stamatis
Published: August 2011

We prove variants of Schwarz's lemma involving monotonicity properties of condenser capacity and inner radius. Also, we examine when a similar monotonicity property holds for the hyperbolic metric.
Wind speed dependent size-resolved parameterization for the organic mass fraction of sea spray aerosol
Authors: Gantt B. , Meskhidze N. , Facchini M. C. , Rinaldi M. , Ceburnis D. , O'Dowd C. D.
Published: August 2011

Abstract. For oceans to be a significant source of primary organic aerosol (POA), sea spray aerosol (SSA) must be highly enriched with organics relative to the bulk seawater. We propose that organic enrichment at the air-sea interface, chemical composition of seawater, and the aerosol size are three main parameters controlling the organic mass fraction of sea spray aerosol (OMSSA). To test this hypothesis, we developed a new marine POA emission function based on a conceptual relationship between the organic enrichment at the air-sea interface and surface wind speed. The resulting parameterization is explored using aerosol chemical composition and surface wind speed from Atlantic and Pacific coastal stations, and satellite-derived ocean concentrations of chlorophyll-a, dissolved organic carbon, and particulate organic carbon. Of all the parameters examined, a multi-variable logistic regression revealed that the combination of 10 m wind speed and surface chlorophyll-a concentration ([Chl-a]) are the most consistent predictors of OMSSA. This relationship, combined with the published aerosol size dependence of OMSSA, resulted in a new parameterization for the organic mass fraction of SSA. Global emissions of marine POA are investigated here by applying this newly-developed relationship to existing sea spray emission functions, satellite-derived [Chl-a], and modeled 10 m winds. Analysis of model simulations shows that global annual submicron marine organic emission associated with sea spray is estimated to be from 2.8 to 5.6 Tg C yr−1. This study provides additional evidence that marine primary organic aerosols are a globally significant source of organics in the atmosphere.
Analysis of cloud condensation nuclei composition and growth kinetics using a pumped counterflow virtual impactor and aerosol mass spectrometer
Authors: Slowik J. G. , Cziczo D. J. , Abbatt J. P. D.
Published: August 2011

Abstract. We present a new method of determining the size and composition of CCN-active aerosol particles. Method utility is illustrated through a series of ambient measurements. A continuous-flow thermal-gradient diffusion chamber (TGDC), pumped counterflow virtual impactor (PCVI), and Aerodyne time-of-flight mass spectrometer (AMS) are operated in series. Ambient particles are sampled into the TGDC, where a constant supersaturation is maintained, and CCN-active particles grow to ~2.5 ± 0.5 μm. The output flow from the TGDC is directed into the PCVI, where a counterflow of dry N2 gas opposes the particle-laden flow, creating a region of zero axial velocity. This stagnation plane can only be traversed by particles with sufficient momentum, which depends on their size. Particles that have activated in the TGDC cross the stagnation plane and are entrained in the PCVI output flow, while the unactivated particles are diverted to a pump. Because the input gas is replaced by the counterflow gas with better than 99 % efficiency at the stagnation plane, the output flow consists almost entirely of dry N2 and water evaporates from the activated particles. In this way, the system yields an ensemble of CCN-active particles whose chemical composition and size are analyzed using the AMS. Measurements of urban aerosol in downtown Toronto identified an external mixture of CCN-active particles consisting almost entirely of ammonium nitrate and ammonium sulfate, with CCN-inactive particles of the same size consisting of a mixture of ammonium nitrate, ammonium sulfate, and organics. We also discuss results from the first field deployment of the TGDC-PCVI-AMS system, conducted from mid-May to mid-June 2007 in Egbert, Ontario, a semirural site ~80 km north of Toronto influenced both by clean air masses from the north and emissions from the city. Organic-dominated particles sampled during a major biogenic event exhibited higher CCN activity and/or faster growth kinetics than urban outflow from Toronto, despite the latter having a higher inorganic content and higher O:C ratio. During both events, particles were largely internally mixed.
Interplanetary coronal mass ejections in the near-Earth solar wind during the minimum periods following solar cycles 22 and 23
Authors: Kilpua E. K. J. , Lee C. O. , Luhmann J. G. , Li Y.
Published: August 2011

Abstract. In this paper we examine the occurrence rates and properties of interplanetary coronal mass ejections (ICMEs) and solar activity levels during the minima following solar cycle 22 (January 1995–December 1997) and 23 (January 2007–April 2010) minima using observations from the OMNI data base. Throughout the minimum following cycle 22 the CME and ICME rates roughly tracked each other, while for the minimum following cycle 23 they diverged. During the minimum after solar cycle 23, there were large variations in the streamer belt structure. During the lowest activity period of cycle 23 (based on sunspot numbers), the ICME rate was about four times higher than during a similar activity period of cycle 22. We propose that this relatively high ICME rate may be due to CME source regions occurring at lower heliolatitudes and due to equatoward deflection of slow and weak CMEs originating from the mid- and high-heliolatitudes. The maximum magnetic fields of the ICMEs identified during the minimum following cycle 23 were ~30 % lower and their radial widths were ~15 % lower compared to the ICMEs observed during the minimum following solar cycle 22. The weak and small ICMEs may result from intrinsically weak CMEs and/or they may represent stronger CMEs that are encountered far away from the center.
Effect of ion beam on electromagnetic ion cyclotron instability in hot anisotropic plasma-particle aspect analysis
Authors: Patel S. , Varma P. , Tiwari M. S. , Shukla N.
Published: August 2011

Abstract. Using the general loss-cone distribution function electromagnetic ion cyclotron (EMIC) instability affected by up going ion beam has been studied by investigating the trajectories of charged particles. The plasma consisting of resonant and non-resonant particles has been considered. It is assumed that the resonant particles participate in energy exchange with the wave, whereas non-resonant particles support the oscillatory motion of the wave. The effect of ion beam velocity on the dispersion relation, growth rate, parallel and perpendicular resonant energy of the EMIC wave with general loss-cone distribution function in hot anisotropic plasma is described by particle aspect approach. The effect of beam anisotropy and beam density on electromagnetic ion cyclotron instabilities is investigated. Growth length is derived for EMIC waves in hot anisotropic plasma. It is found that the effect of the ion beam is to reduce the energy of transversely heated ions, whereas the thermal anisotropy of the background plasma acts as a source of free energy for the EMIC wave and enhances the growth rate. It is observed that ion beam velocity opposite to the wave propagation and its density reduces the growth rate and enhance the reduction in perpendicularly heated ions energy. The effect of ion beam anisotropy on EMIC wave is also discussed. These results are determined for auroral acceleration region. It is also found that the EMIC wave emissions occur by extracting energy of perpendicularly heated ions in the presence of an up flowing ion beam.
Winter-spring cyclonic variability in the Mediterranean-Black Sea region associated with global processes in the ocean-atmosphere system
Authors: Voskresenskaya E. N. , Maslova V. N.
Published: August 2011

Abstract. Using global NCEP/NCAR reanalysis data set on 1000 hPa geopotential height (1948–2006), cyclones in the Mediterranean and Black Sea regions were detected and their main characteristics (frequency, depth, integrated area) were calculated. Analysis of their interannual-multidecadal variability in January-March associated with global processes in the ocean-atmosphere system was done. It was shown that North Atlantic Oscillation (NAO) manifests in the Black Sea region mainly in the variability of frequency of cyclones while in the Mediterranean – in the interannual anomalies of cyclones' depth and area. Joint NAO and El Nino – Southern Oscillation (ENSO) influence is responsible for about 20–45% of cyclones' frequency variance in the Black Sea region, and in the Mediterranean region for up to 10–25 and 20–30% of the depth and area variance, accordingly. As a result of using a new approach to study ENSO manifestations based on El Nino classification, correlation coefficients between characteristics of cyclones and Southern Oscillation index (SOI) increase at least twice. The influence of the Pacific Decadal and Atlantic Multidecadal Oscillations on variability of cyclonic activity in the Mediterranean-Black Sea region manifests in considerable differences of cyclones' characteristics and their typical location.
Sensitivity of Red Sea circulation to sea level and insolation forcing during the last interglacial
Authors: Trommer G. , Siccha M. , Rohling E. J. , Grant K. , van der Meer M. T. J. , Schouten S. , Baranowski U. , Kucera M.
Published: August 2011

Abstract. This study investigates the response of Red Sea circulation to sea level and insolation changes during termination II and across the last interglacial, in comparison with termination I and the Holocene. Sediment cores from the central and northern part of the Red Sea were investigated by micropaleontological and geochemical proxies. The recovery of the planktic foraminiferal fauna following high salinities during marine isotopic stage (MIS) 6 took place at similar sea-level stand (~50 m below present day), and with a similar species succession, as during termination I. This indicates a consistent sensitivity of the basin oceanography and the plankton ecology to sea-level forcing. Based on planktic foraminifera, we find that increased water exchange with the Gulf of Aden especially occurred during the sea-level highstand of interglacial MIS 5e. From MIS 6 to the peak of MIS 5e, northern Red Sea sea surface temperature (SST) increased from 21 °C to 25 °C, with about 3 °C of this increase taking place during termination II. Changes in planktic foraminiferal assemblages indicate that the development of the Red Sea oceanography during MIS 5 was strongly determined by insolation and monsoon strength. The SW Monsoon summer circulation mode was enhanced during the termination, causing low productivity in northern central Red Sea core KL9, marked by high abundance of G. sacculifer, which – as in the Holocene – followed summer insolation. Core KL11 records the northern tip of the intruding intermediate water layer from the Gulf of Aden and its planktic foraminifera fauna shows evidence for elevated productivity during the sea-level highstand in the southern central Red Sea. By the time of MIS 5 sea-level regression, elevated organic biomarker BIT values suggest denudation of soil organic matter into the Red Sea and high abundances of G. glutinata, and high reconstructed chlorophyll-a values, indicate an intensified NE Monsoon winter circulation mode. Our results imply that the amplitude of insolation fluctuations, and the resulting monsoon strength, strongly influence the Red Sea oceanography during sea-level highstands by regulating the intensity of water exchange with the Gulf of Aden. These processes are responsible for the observation that MIS 5e/d is characterized by higher primary productivity than the Holocene.
A millennial multi-proxy reconstruction of summer PDSI for Southern South America
Authors: Boucher É. , Guiot J. , Chapron E.
Published: August 2011

Abstract. We present the first spatially explicit field reconstruction of the summer (DJF) Palmer Drought Severity Index (PDSI) for the Southern Hemisphere. Our multi-proxy reconstruction focuses on Southern South America (SSA, south of 20° S) and is based on a novel spectral analogue method that aims at reconstructing low PDSI frequencies independently from higher frequencies. The analysis of past regimes and trends in extreme wet spells and droughts reveals considerable geographical and temporal variations over the last millennium in SSA. Although recent changes are in some cases notorious, most were not exceptional at the scale of the last thousand years. Our reconstruction highlights that low frequency water availability fluctuations in Patagonia were generally in antiphase with the rest of the subcontinent. Providing the fact that modern patterns of changes are transferable to the past, we show that such antiphases within SSA's hydroclimate could be attributed to the spatially contrasted response of summer PDSI to the Antarctic Oscillation (AAO). However, El Niño Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) signals are also embedded within the PDSI series during the 20th century. All these ocean-atmospheric forcings acted synergically, but the dominant influence appeared highly compartmentalized through space, highlighting clear AAO- (e.g. South Patagonia) and ENSO- (e.g. the Pampas) dominated regions. Our results therefore emphasize the complexity of water-availability fluctuations in SSA and their important dependence on external ocean-atmospheric forcings.
Discharge estimation in a backwater affected meandering river
Authors: Hidayat H. , Vermeulen B. , Sassi M. G. , Torfs P. J. J. F. , Hoitink A. J. F.
Published: August 2011

Abstract. Variable effects of backwaters complicate the development of rating curves at hydrometric measurement stations. In areas influenced by backwater, single-parameter rating curve techniques are often inapplicable. To overcome this, several authors have advocated the use of an additional downstream level gauge to estimate the longitudinal surface level gradient, but this is cumbersome in a lowland meandering river with considerable transverse surface level gradients. Recent developments allow river flow to be continuously monitored through velocity measurements with an acoustic Doppler current profiler (H-ADCP), deployed horizontally at a river bank. This approach was adopted to obtain continuous discharge estimates at a cross-section in the River Mahakam at a station located about 300 km upstream of the river mouth in the Mahakam delta. The discharge station represents an area influenced by variable backwater effects from lakes, tributaries and floodplain ponds, and by tides. We applied both the standard index velocity method and a recently developed methodology to obtain a continuous time-series of discharge from the H-ADCP data. Measurements with a boat-mounted ADCP were used for calibration and validation of the model to translate H-ADCP velocity to discharge. As a comparison with conventional discharge estimation techniques, a stage-discharge relation using Jones formula was developed. The discharge rate at the station exceeded 3250 m3 s−1. Discharge series from a traditional stage-discharge relation did not capture the overall discharge dynamics, as inferred from H-ADCP data. For a specific river stage, the discharge range could be as high as 2000 m3 s−1, which is far beyond what could be explained from kinematic wave dynamics. Backwater effects from lakes were shown to be significant, whereas interaction of the river flow with tides may impact discharge variation in the fortnightly frequency band. Fortnightly tides cannot easily be isolated from river discharge variation, which features similar periodicities.
Comparison and evaluation of satellite derived precipitation products for hydrological modeling of the Zambezi River Basin
Authors: Cohen Liechti T. , Matos J. P. , Boillat J.-L. , Schleiss A. J.
Published: August 2011

Abstract. In the framework of the African Dams ProjecT (ADAPT), an integrated water resource management study in the Zambezi Basin is currently under development. In view of the sparse gauging network for rainfall monitoring, the observations from spaceborne instrumentation currently produce the only available rainfall data for a large part of the basin. Three operational and acknowledged high resolution satellite derived estimates: the Tropical Rainfall Measuring Mission product 3B42 (TRMM 3B42), the Famine Early Warning System product 2.0 (FEWS RFE2.0) and the National Oceanic and Atmospheric Administration/Climate Prediction Centre (NOAA/CPC) morphing technique (CMORPH) are analyzed in terms of spatial and temporal repartition of the precipitations. They are compared to ground data for the wet seasons of the years 2003 to 2009 on a point to pixel basis at daily, 10-daily and monthly time steps and on a pixel to pixel basis for the wet seasons of the years 2003 to 2007 at monthly time steps. The general North-South gradient of precipitation is captured by all the analyzed products. Regarding the spatial heterogeneity, FEWS pixels are much more inter-correlated than TRMM and CMORPH pixels. For a rainfall homogeneity threshold criterion of 0.5 global mean correlation coefficient, the area of each subbasin should not exceed a circle of 2.5° latitude/longitude radius for FEWS and a circle of 0.75° latitude/longitude radius for TRMM and CMORPH considering rectangular mesh. In terms of reliability, the correspondence of all estimates with ground data increases with the time step chosen for the analysis. The volume ratio computation indicates that CMORPH is overestimating by nearly 1.5 times the rainfall. The statistics of TRMM and FEWS estimates show quite similar results. Due to the its lower inter-correlation and longer data set, the TRMM 3B42 product is chosen as input for the hydraulic-hydrologic model of the basin. Further work will focus on the calibration of the hydraulic-hydrological model of the basin, including the major existing hydraulic structures with their operation rules.
Integral Cost-Benefit Analysis of Maglev Rail Projects Under Market Imperfections
Authors: Elhorst J. Paul , Oosterhaven Jan
Published: August 2011

This article evaluates a new mode of high speed ground transportation, the magnetic levitation rail system (Maglev). The outcomes of this evaluation provide policy information on the interregional redistribution of employment and population and the national welfare improvement of two Dutch urban-conglomeration and two Dutch core-periphery projects. This article also compares the results of an integral cost- benefit analysis with those of a conventional cost-benefit analysis and concludes that the additional economic benefits due to market imperfections vary from –1% to +38% of the direct transport benefits, depending on the type of regions connected and the general condition of the economy.
Long-Term Outcome of Epi-LASIK for High Myopia
Authors: Wang Shiyuan , Dai Jinhui , Chu Renyuan , Zhou Xingtao
Published: August 2011

Purpose

To evaluate the long-term outcomes of epipolis laser-assisted in situ keratomileusis (epi-LASIK) for high myopia.

Methods

High myopic patients who underwent epi-LASIK during 2004 and 2005 were included in this study. Epi-LASIK was performed with an automatically rotational epikeratome (KM-5000D). Postoperative visual acuity, manifest refraction, and haze formation were assessed 3 mo, 6 mo, 1 y, and 3 y after surgery. Results were compared by dividing patients into 2 groups according to preoperative mean refractive spherical equivalent (MRSE): group A (≥–6 D to −10 D; group B ≥–10 D). The differences within groups were analyzed using mixed model for continuous variables. The differences between groups were analyzed using t test or rank sum test for continuous variables, and Pearson χ2 or Fisher exact probabilities for categorical variables.

Results

A total of 20 patients (33 eyes) were followed up for more than 3 years with 17 eyes in group A (MRSE −8.15±1.41 D) and 16 eyes in group B (MRSE −12.95±2.91 D). While postoperative refraction regression occurred in both groups, it was more prominent in group B (p<0.05). The long-term predictability is good in group A with 14 eyes (82.35%) within ±1 D of attempted correction at 3 years while the percentage in group B was 18.75%. The efficacy index was significantly different between the 2 groups (p<0.05): 0.84±0.29 for group A and 0.61±0.47 for group B at 3 years. The safety index was above 1.0 at each timepoint in both groups. Haze was at low level and faded with time after epi-LASIK.

Conclusions

Epi-LASIK had a satisfactory long-term effect for high myopia of less than −10 D. Myopic regression limited the satisfaction of epi-LASIK in eyes with myopia of more than −10.0 D.
Reemergence of dormant Coats disease after 30 years
Authors: Pérez-Campagne Eric , Wolfensberger Thomas J.
Published: August 2011

Purpose

We describe an atypical case of a patient with Coats disease that re-emerged after 30 years, illustrating a previously poorly understood long-term evolution of the disease.

Methods

A 20-year-old man consulted for visual acuity (VA) decrease in the left eye (LE) to 0.3. Fundus examination revealed an exudative lesion with telangiectasias in the superior peripheral retina compatible with the diagnosis of Coats disease.

Results

The patient was treated with cryotherapy and argon laser. Visual acuity improved to 0.5 and remained stable during a 1-year follow-up. The patient did not seek further clinical follow-up. Thirty years later, he returned complaining of a progressive VA decrease in the LE. Snellen VA was measured to counting fingers. Fundus examination revealed stage 3A Coats disease with macular exudation and a serous retinal detachment in the inferior quadrants requiring the placement of an encircling band, external drainage, and cryotherapy of the vascular lesions. After 10 additional sessions of argon laser on the vascular malformations, exudation regressed further and best-corrected VA increased to 0.1 at the end of the follow-up period.

Conclusions

Coats disease must be considered as a chronic disease, which necessitates a very long-term follow-up even in the absence of subjective visual loss. The disease can reawaken and recur with force in previously unaffected areas of the retina several decades later. The gold standard treatment consists of cryotherapy and argon laser. However, in cases of very important retinal exudation, surgical management with subretinal drainage may be necessary.
Carcinoma of the Breast With Choriocarcinomatous Features
Authors: Mohammadi Amir , Rosa Marilin
Published: August 2011

Choriocarcinomatous differentiation has been described in tumors arising from many organs including lung, rectum, colon, stomach, bladder, and rarely breast. Mammary carcinoma with choriocarcinomatous features is a rare variant of breast metaplastic carcinoma characterized by malignant cells morphologically resembling choriocarcinoma cells in which reactivity with human placental lactogen and human chorionic gonadotropin can be demonstrated by immunohistochemistry. The characteristic syncytiotrophoblast-like giant cells seen in these neoplasms are more commonly associated with moderately to poorly differentiated carcinomas with or without a clear-cut mesenchymal component. Most of the reported cases have behaved very aggressively. The reason for this poor prognosis remains unclear. Because of the small number of cases, special treatment protocols have not been developed and these patients are treated surgically and with the standard chemotherapeutic agents available for other types of carcinoma of the breast. Pathologically, these tumors must be distinguished from metastatic choriocarcinoma to the breast.
Genomic Aberrations in Salivary Duct Carcinoma Arising in Warthin Tumor of Parotid Gland: DNA Microarray and HER2 Fluorescence In Situ Hybridization
Authors: Kim Hyun-Jung , Yoo Young Sam , Park Kyeongmee , Kwon Ji-Eun , Kim Jung Yeon , Monzon Federico A
Published: August 2011

Carcinoma arising from Warthin tumor is extremely rare. A 79-year-old man was admitted for a firm, well-defined, 5-cm left infra-auricular mass. Aspiration cytology showed many lymphohistiocytes and oncocytes in a proteinaceous background, compatible with Warthin tumor. A left superficial parotidectomy showed a solid mass around the cyst wall. The tumor cells of the solid area were arranged as infiltrative ducts with a few foci of malignant transformation. Virtual karyotyping disclosed a complex pattern of genetic aberrations with a focal amplification in 12q14–q21.2. This chromosomal region contains the MDM2 (murine double minute) gene, which regulates p53 inactivation. HER2 fluorescence in situ hybridization showed a focal amplification. Subsequently, the patient underwent total parotidectomy and ipsilateral neck dissection for a recurrence. To our knowledge, this is the first case of salivary duct carcinoma arising from Warthin tumor. The essential molecular pathway has not been reported, we presume an important role of MDM2 amplification–P53 inactivation.
Granulomatous Dermatitis due to Malassezia sympodialis
Authors: Desai Harsha B , Perkins Philip L , Procop Gary W
Published: August 2011

A 67-year-old man, with multiple skin lesions that appeared over 2 years, had biopsies that disclosed granulomatous dermatitis with associated small yeasts. The urinary antigen test results were negative for Histoplasma infection; cultures from the biopsies did not grow any fungi or other potential pathogens. The chest roentgenogram results were normal. Morphologic examination revealed features of a Malassezia species. Broad-range fungal polymerase chain reaction and DNA sequencing disclosed that the infecting fungus was Malassezia sympodialis, a lipid-dependent yeast. This report supports one other case report that Malassezia species may cause granulomatous dermatitis; in the previous case, the etiologic agent was Malassezia pachydermatis, a nonlipid-dependent species. We recommend the use of lipid-supplemented culture media for specimens from patients with granulomatous dermatitis because several Malassezia species are dependent on lipid; the absence of lipid supplementation in routine cultures likely explains the negative culture results for this patient. This, to our knowledge, is the first report of granulomatous dermatitis caused by M sympodialis.
Mesenchymal stem cells expanded in human platelet lysate display a decreased inhibitory capacity on T‐ and NK‐cell proliferation and function
Authors: Abdelrazik Heba , Spaggiari Grazia M. , Chiossone Laura , Moretta Lorenzo
Published: August 2011

The use of fetal bovine serum (FBS) for the culture and expansion of mesenchymal stromal cells (MSCs) limits their possible clinical applications. Although some recent studies recommended substituting FBS with human platelet lysate (HPL) for the expansion of MSCs for clinical use, the functional capacity of the expanded cells has only been partially explored. 10% FBS and two other commercial FBS‐containing media (MesenCult and MesenPro) were compared with 10% HPL‐containing medium for their ability to support MSCs expansion and immunomodulation. We demonstrate that HPL sustained MSC proliferation and expansion in vitro. However, the cumulative cell numbers recovered were comparable with those obtained in MesenPro medium. Moreover, we show that HPL alters the expression of some relevant MSC surface molecules, namely the DNAM‐1 ligands PVR and Nectin‐2, the NKG2D ligand ULBP3, the adhesion molecules CD49d and αvβ3 and the fibroblast‐associated protein. In addition, MSCs cultured in HPL displayed impaired inhibitory capacity on T‐cell proliferation to alloantigen and NK‐cell proliferation and cytotoxicity. Finally, they showed decreased constitutive PGE2 production while IL‐6, IL‐8 and RANTES secretion were upregulated. These results imply some limitations in the use of HPL for the expansion of MSCs to be used as immunomodulators in clinical applications.
Quantification of pH gradients and implications in insulator‐based dielectrophoresis of biomolecules
Authors: Gencoglu Aytug , Camacho‐Alanis Fernanda , Nguyen Vi Thanh , Nakano Asuka , Ros Alexandra , Minerick Adrienne R.
Published: August 2011

Direct current (DC) insulator‐based dielectrophoretic (iDEP) microdevices have the potential to replace traditional alternating current dielectrophoretic devices for many cellular and biomolecular separation applications. The use of large DC fields suggest that electrode reactions and ion transport mechanisms can become important and impact ion distributions in the nanoliters of fluid in iDEP microchannels. This work tracked natural pH gradient formation in a 100 μm wide, 1 cm‐long microchannel under applicable iDEP protein manipulation conditions. Using fluorescence microscopy with the pH‐sensitive dye FITC Isomer I and the pH‐insensitive dye TRITC as a reference, pH was observed to drop drastically in the microchannels within 1 min in a 3000 V/cm electric field; pH drops were observed in the range of 6–10 min within a 100 V/cm electric field and varied based on the buffer conductivity. To address concerns of dye transport impacting intensity data, electrokinetic mobilities of FITC were carefully examined and found to be (i) toward the anode and (ii) 1 to 2 orders of magnitude smaller than H+ transport which is responsible for pH drops from the anode toward the cathode. COMSOL simulations of ion transport showed qualitative agreement with experimental results. The results indicate that pH changes are severe enough and rapid enough to influence the net charge of a protein or cause aggregation during iDEP experiments. The results also elucidate reasonable time periods over which the phosphate buffering capacity can counter increases in H+ and OH− for unperturbed iDEP manipulations.
A new logarithmic method to minimize the size of low‐pass filter using multilayer and defected ground structure technique
Authors: Boutejdar Ahmed , Omar Abbas , Burte Edmund , Batmanov Anatoliy , Mikuta Reinhard
Published: August 2011

A novel three‐pole low‐pass filter is designed using metal‐loaded slots etched in the ground plane, and low impedance microstrip line as microstrip capacitor. An equivalent circuit model of a defected ground structure (DGS) is applied to study the characteristics of DGS. Parameters of the model are extracted from the EM simulation results by matching it to a one‐pole Butterworth low‐pass filter. The theory is validated against the commercial Microwave Office. The new low‐pass filter (LPF) is very compact and provides sharp transition band and a wide stop‐band. Additional to the new mathematical method (natural logarithm function), a multilayer technique will be used to improve the compactness of the structure. Finally, the proposed structure is implemented, and the measurement results are found to be in good agreement with the simulation results. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2561–2566, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26352
Volatility forecasts evaluation and comparison
Authors: Laurent Sébastien , Violante Francesco
Published: August 2011

This article surveys the most important developments in volatility forecast comparison and model selection. We review a number of evaluation methods and testing procedures for predictive accuracy based on statistical loss functions. We also review recent contributions on the admissible form of loss functions ensuring consistency of the ordering when forecast performances are evaluated with respect to an imperfect volatility proxy. The techniques discussed are illustrated using artificial and EUR/USD exchange rate data. WIREs Comp Stat 2012, 4:1–12. doi: 10.1002/wics.190

This article is categorized under:

Statistical Models > Time Series Models

Data: Types and Structure > Time Series, Stochastic Processes, and Functional Data

Applications of Computational Statistics > Computational Finance
Learning to cooperate in the Iterated Prisoner’s Dilemma by means of social attachments
Authors: Bazzan Ana L. C. , Peleteiro Ana , Burguillo Juan C.
Published: August 2011

The Iterated Prisoner’s Dilemma (IPD) has been used as a paradigm for studying the emergence of cooperation among individual agents. Many computer experiments show that cooperation does arise under certain conditions. In particular, the spatial version of the IPD has been used and analyzed to understand the role of local interactions in the emergence and maintenance of cooperation. It is known that individual learning leads players to the Nash equilibrium of the game, which means that cooperation is not selected. Therefore, in this paper we propose that when players have social attachment, learning may lead to a certain rate of cooperation. We perform experiments where agents play the spatial IPD considering social relationships such as belonging to a hierarchy or to coalition. Results show that learners end up cooperating, especially when coalitions emerge.
Distribution of human papillomavirus genotypes in archival cervical tissue from women with cervical cancer in urban Sri Lanka
Authors: Samarawickrema Nirma A. , Tabrizi Sepehr N. , Hewavisenthi Janaki , Leong Trishe , Garland Suzanne M.
Published: August 2011

Objective

To identify the contributions of various human papillomavirus (HPV) genotypes in tissue samples from women diagnosed with cervical cancer in Sri Lanka.

Methods

In a retrospective study, archival cervical tissues samples (n = 108) obtained from Sri Lankan women diagnosed with histologically proven invasive squamous cell carcinoma between 2006 and 2007 were tested for HPV. Genotyping of HPV DNA was performed using an INNO‐LiPA assay.

Results

Overall, 93% of tumor samples tested positive for HPV DNA. HPV types 16 and 18 accounted collectively for 83.4% of the positive samples.

Conclusion

The findings suggest that the HPV genotypes responsible for causing cervical cancer in Sri Lanka are similar to those reported elsewhere worldwide. Consequently, women in Sri Lanka could benefit from currently available prophylactic HPV vaccines should they be implemented.
H1N1 influenza pandemic and maternal mortality in Antioquia, Colombia
Authors: Velásquez Jesús , Vélez Gladis , Zuleta John , Franco Francisco , Gómez Joaquín
Published: August 2011

Objective

To evaluate the impact of the H1N1 influenza pandemic on maternal mortality in the province of Antioquia, Colombia, in 2009.

Methods

The present study was a descriptive, retrospective, cross‐sectional study of maternal deaths in Antioquia in 2009 caused by H1N1‐related pneumonia. The study formed part of the epidemiologic surveillance process undertaken by the Health and Social Protection Directorate of Antioquia and the particular healthcare institutions involved in the cases.

Results

In 2009, there were 42 maternal deaths in Antioquia, corresponding to a maternal mortality ratio of 46 per 100 000 live births. Ten deaths were due to pneumonia, 9 of which occurred after the H1N1 outbreak was first reported in early 2009. In 3 cases, the women were confirmed to have H1N1 virus infection, and the remainder fulfilled probable case criteria. The main factors contributing to the deaths were underestimation of H1N1 symptoms, and delays in administration of antiviral medication and in hospitalization.

Conclusion

For the population subgroup of pregnant women in Antioquia, it is crucial to remain alert regarding H1N1 virus infection, guaranteeing patients adequate monitoring and/or timely administration of immunization, medication, and hospitalization.
A clinicopathologic study of gynecologic organ involvement at radical cystectomy for bladder cancer
Authors: Salem Hosni , El‐Mazny Akmal
Published: August 2011

Objective

To report the clinicopathologic analysis of women who underwent radical cystectomy for bladder cancer in Egypt from 1997 to 2005.

Methods

Clinicopathologic data for 250 women who underwent radical cystectomy for bladder cancer at 3 centers in Cairo were retrospectively reviewed from hospital charts and pathology sheet records. Cystectomy specimens were evaluated pathologically for involvement of internal genitalia.

Results

The uterus was not available for histopathologic examination in 11 specimens; 1 ovary was absent from 18 specimens; and both ovaries were absent from 2 specimens. Uterine involvement was observed in 1 case of transitional cell carcinoma. Benign uterine pathology was detected in 25 cases. All patients had normal ovaries, and the vagina was involved in 11 cases. There was urethral involvement in 10% of patients. Of the 50 patients available for follow‐up, 11 had 1 ovary preserved and 2 had the uterus plus both ovaries preserved. None of them experienced late ovarian or uterine recurrence.

Conclusion

Involvement of female internal genitalia in bladder cancer is uncommon. Thus, preservation of these organs in young women undergoing radical cystectomy should be considered in selected cases after careful preoperative assessment.
Influence of ethnicity on the clinical and biologic expression of pre‐eclampsia in the ECLAXIR study
Authors: Anselem Olivia , Girard Guillaume , Stepanian Alain , Azria Elie , Mandelbrot Laurent
Published: August 2011

Objective

To determine whether ethnic origin is related to the clinical and biologic expression of pre‐eclampsia.

Methods

In a secondary analysis of information collected in the ECLAXIR study in France between May 2003 and October 2006, the data from 284 white European, 84 Maghrebian and 158 African women were evaluated in a case–control study of the genetic and endothelial determinants of pre‐eclampsia.

Results

African origin was a risk factor for pre‐eclampsia before 28 weeks of gestation. Symptoms related to hypertension, such as neurologic signs and changes in biologic parameters (e.g. hemolysis elevated liver enzymes, low platelet count [HELLP] syndrome), occurred more frequently among white European women. After logistic regression, gestational age at delivery was lower for African women than for white European women (33.4 weeks versus 34.4 weeks of gestation, P = 0.04).

Conclusion

The results suggest that ethnic origin may have a role in the expression of pre‐eclampsia, and should therefore be taken into account in prenatal surveillance. Further research on the genetic factors involved in endothelial dysfunction is warranted.
Oral misoprostol for the management of incomplete abortion in Ecuador
Authors: Montesinos Rolando , Durocher Jill , León Wilfrido , Arellano Mónica , Peña Melanie , Pinto Ernesto , Winikoff Beverly
Published: August 2011

Objective

To assess the feasibility of introducing misoprostol for the treatment of incomplete abortion in Quito, Ecuador.

Methods

In a randomized prospective study conducted at a large tertiary‐level maternity hospital and a private secondary‐level clinic between November 2006 and November 2007, women with incomplete abortion were treated with either 600 μg of oral misoprostol (n = 122) or manual vacuum aspiration (MVA) (n = 120). All participants were requested to return for follow‐up care on day 7 to determine the success of the treatment and to document their satisfaction with the method and the adverse effects experienced.

Results

Sixteen percent of women (39/242) did not return for their follow‐up visit and their outcomes are unknown. Among those who did return, 94% (100/106) of women showed successful completion of abortion after treatment with misoprostol, as compared with 100% (97/97) of women treated with MVA. Most women described their adverse effects after treatment as tolerable (misoprostol, 95%; MVA, 91%). Nearly all women reported being satisfied with their treatment (196/203); there were no differences among the women's reports of satisfaction according to treatment received.

Conclusion

An oral dose of 600 μg of misoprostol was found to be an acceptable and effective non‐surgical option for treating incomplete abortion. Clinical trials.gov NCT00674232.