bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Ventricular Pacing in the Setting of an Institutional Improvement Program: Insights into Physiological Pacing
Authors: Kossaify Antoine , Zoghbi Sylvana , Milliez Paul
Published: March 2012

Background

Excessive ventricular pacing is known to be detrimental. The purpose of this study was to assess ventricular pacing in the setting of an institutional improvement program in order to decrease unnecessary pacing.

Method

This cross-sectional single-center study performed in a university hospital assessed 80 consecutive patients attending for a cardiac electronic device (pacemaker or cardioverter defibrillator) check. Forty percent of ventricular pacing was set as the cutoff level beyond which pacing was considered excessive.

Results

Three patients were excluded. Forty-six (59.7%) patients (group 1) had more than 40% ventricular pacing and 31 (40.3%) patients (group 2) showed ventricular pacing less than 41%. In group 1, corrective action was successful in 27 (58.7%) patients, but 19 (41.3%) continued to have ventricular pacing over 40% and were discussed accordingly. An improvement program was established at the institution in order to decrease unnecessary ventricular pacing.

Conclusion

Unnecessary ventricular pacing was encountered in many of the patients in this study, corrective actions were performed, and an institutional improvement project was set up as a consequence.
A problem of Kollár and Larsen on finite linear groups and crepant resolutions
Authors: Guralnick Robert M. , Tiep Pham Huu
Published: March 2012

The notion of
age
of elements of complex linear groups was introduced by M. Reid and is of importance in algebraic geometry, in particular in the study of crepant resolutions and of quotients of Calabi–Yau varieties. In this paper, we solve a problem raised by J. Kollár and M. Larsen on the structure of finite irreducible linear groups generated by elements of
age

≤ 1

. More generally, we bound the dimension of finite irreducible linear groups generated by elements of bounded deviation. As a consequence of our main results, we derive some properties of symmetric spaces

GU_{d}(\mathbb C)/G

having shortest closed geodesics of bounded length, and of quotients

\mathbb C^{d}/G

having a crepant resolution.
On sets of vectors of a finite vector space in which every subset of basis size is a basis
Authors: Ball Simeon
Published: March 2012

It is shown that the maximum size of a set

{ S}

of vectors of a

k

-dimensional vector space over

{\mathbb F}_q

, with the property that every subset of size

k

is a basis, is at most

q+1

, if

k \leq p

, and at most

q+k-p

, if

q \geq k \geq p+1 \geq 4

, where

q=p^h

and

p

is prime. Moreover, for

k\leq p

, the sets

S

of maximum size are classified, generalising Beniamino Segre's “arc is a conic'' theorem.

These results have various implications. One such implication is that a

k\times (p+2)

matrix, with

k \leq p

and entries from

{\mathbb F}_p

, has

k

columns which are linearly dependent. Another is that the uniform matroid of rank

r

that has a base set of size

n \geq r+2

is representable over

{\mathbb F}_p

if and only if

n \leq p+1

. It also implies that the main conjecture for maximum distance separable codes is true for prime fields; that there are no maximum distance separable linear codes over

{\mathbb F}_p

, of dimension at most

p

, longer than the longest Reed-Solomon codes. The classification implies that the longest maximum distance separable linear codes, whose dimension is bounded above by the characteristic of the field, are Reed–Solomon codes.
Counting walks in a quadrant: a unified approach via boundary value problems
Authors: Raschel Kilian
Published: March 2012

The aim of this article is to introduce a unified method to obtain explicit integral representations of the trivariate generating function counting the walks with small steps which are confined to a quarter plane. For many models, this yields for the first time an explicit expression of the counting generating function. Moreover, the nature of the integrand of the integral formulations is shown to be directly dependent on the finiteness of a naturally attached group of birational transformations as well as on the sign of the covariance of the walk.
Triangle-intersecting families of graphs
Authors: Ellis David , Filmus Yuval , Friedgut Ehud
Published: March 2012

A family

\mathcal F

of graphs is
triangle-intersecting
if for every

G,H\in\mathcal F

,

G \cap H

contains a triangle. A conjecture of Simonovits and Sós from 1976 states that the largest triangle-intersecting families of graphs on a fixed set of

n

vertices are those obtained by fixing a specific triangle and taking all graphs containing it, resulting in a family of size

\frac{1}{8}2^{\binom{n}{2}}

. We prove this conjecture and some generalizations (for example, we prove that the same is true of odd-cycle-intersecting families, and we obtain best possible bounds on the size of the family under different, not necessarily uniform, measures). We also obtain stability results, showing that almost-largest triangle-intersecting families have approximately the same structure.
Construction of Einstein metrics by generalized Dehn filling
Authors: Bamler Richard H.
Published: March 2012

In this paper, we present a new approach to the construction of Einstein metrics by a generalization of Thurston's Dehn filling. In particular in dimension 3, we will obtain an analytic proof of Thurston's result.
Families of hypersurfaces of large degree
Authors: Mourougane Christophe
Published: March 2012

Grauert and Manin showed that a non-isotrivial family of compact complex hyperbolic curves has finitely many sections. We consider a generic moving enough family of high enough degree hypersurfaces in a complex projective space. We show the existence of a strict closed subset of its total space that contains the image of all its sections.
Matrix identities involving multiplication and transposition
Authors: Auinger Karl , Dolinka Igor , Volkov Mikhail V.
Published: March 2012

We study matrix identities involving multiplication and unary operations such as transposition or Moore–Penrose inversion. We prove that in many cases such identities admit no finite basis.
On ramified covers of the projective plane II: Generalizing Segre’s theory
Authors: Friedman Michael , Lehman Rebecca , Leyenson Maxim , Teicher Mina
Published: March 2012

The classical Segre theory gives a necessary and sufficient condition for a plane curve to be a branch curve of a (generic) projection of a smooth surface in

\mathbb P^3

. We generalize this result for smooth surfaces in a projective space of any dimension in the following way: given two plane curves,

B

and

E

, we give a necessary and sufficient condition for

B

to be the branch curve of a surface

X

in

\mathbb P^N

and

E

to be the image of the double curve of a

\mathbb P^3

-model of

X

.In the classical Segre theory, a plane curve

B

is a branch curve of a smooth surface in

\mathbb P^3

iff its 0-cycle of singularities is special with respect to a linear system of plane curves of particular degree. Here we prove that

B

is a branch curve of a surface in

\mathbb P^N

iff (part of) the cycle of singularities of the union of

B

and

E

is special with respect to the linear system of plane curves of a particular low degree. In particular, given just a curve

B

, we provide some necessary conditions for

B

to be a branch curve of a smooth surface in

\mathbb P^N

.
Effect of Impact Orientation on Bird Strike Analysis
Authors: Hedayati Reza , Ziaei-Rad Saeed
Published: March 2012

Impacts between birds and aircrafts, known as bird-strike events, are very common and dangerous. Not many investigations have been carried out on the effect of orientation at which a bird impacts a surface. However, it can be an important factor because in real bird strike events, the birds do not always impact a surface from the same orientation. In this paper, a geometrical model for birds which is more similar to a real bird anatomy is introduced and used. Next, the results obtained from different orientations at which a Bufflehead duck strikes a surface are compared. It is concluded that the bottom side impact is the most dangerous scenario while the tail side impact is the less dangerous scenario.
Validation of Rear Axle with Differential Lock for Off-Road Vehicles
Authors: Biswas Sanjoy , Ranjan Das Saswata , Mandal Goutam , Sharma Sanjay
Published: March 2012

In today s scenario, rear axle with differential lock arrangement is one of the key required parameter for military vehicles. As per the current central motor vehicles rules an all wheel drive army vehicle can be considered as an off-road vehicle if the vehicle at least has an arrangement of differential lock at its rear axle. This paper details the development of such rear axle with differential lock and validation of the design in-line with the durability test on heavy duty chassis dynamometer. A comparison of recommended design standards and test results is also presented.
A simple method to reduce optical cross‐talk effects in chemical imaging with planar optodes
Authors: Mayr Torsten , Ungerböck Birgit , Mistlberger Günter , Borisov Sergey M. , Klimant Ingo
Published: March 2012

A simple and universal method to minimize optical cross‐talk in chemical imaging with planar optodes used for metabolic investigation of benthic interfaces is presented. Cross‐talk can lead to smeared images and flattened gradients and therefore to erroneous analytical results. To minimize the cross‐talk effect, an additional optical filter layer is coated on the downside of the transparent support. Cross‐talk light traveling in the support and decoupled by scattering media is absorbed to a higher extent than the virtual signal. The extent of cross‐talk and its reduction was evaluated by imaging the luminescence intensity of sensor layers with sharp edges and isolated points. The influence of cross‐talk on the accuracy of oxygen determination by lifetime measurements was investigated by analyzing aerated and de‐aerated zones of a planar optode placed on a scattering media. The presented method is compared qualitatively with methods previously described to reduce optical cross‐talk effects.
An intercomparison of procedures for the determination of total mercury in seawater and recommendations regarding mercury speciation during GEOTRACES cruises
Authors: Lamborg Carl H. , Hammerschmidt Chad R. , Gill Gary A. , Mason Robert P. , Gichuki Susan
Published: March 2012

We conducted a laboratory intercomparison of total mercury (Hg) determination in seawater collected during U.S. GEOTRACES Intercalibration cruises in 2008 and 2009 to the NW Atlantic and NE Pacific Oceans. Results indicated substantial disagreement between the participating laboratories, which appeared to be affected most strongly by bottle cleanliness and preservation procedures. In addition, we examined the effectiveness of various collection and sample preparation procedures that may be used on future GEOTRACES cruises. The type of sampling system and filtration medium appeared to make little difference to results. Finally, and in light of results from experiments that considered sample bottle material effect and the development of new methods for CH3Hg+ extraction from seawater, we propose a recommended procedure for determining all four of the major Hg species in seawater (elemental, dimethyl‐, monomethyl‐, and total Hg).
Assimilation of IASI partial tropospheric columns with an Ensemble Kalman Filter over Europe
Authors: Coman A. , Foret G. , Beekmann M. , Eremenko M. , Dufour G. , Gaubert B. , Ung A. , Schmechtig C. , Flaud J.-M. , Bergametti G.
Published: March 2012

Abstract. Partial lower tropospheric ozone columns provided by the IASI (Infrared Atmospheric Sounding Interferometer) instrument have been assimilated into a chemistry-transport model at continental scale (CHIMERE) using an Ensemble Square Root Kalman Filter (EnSRF). Analyses are made for the month of July 2007 over the European domain. Launched in 2006, aboard the MetOp-A satellite, IASI shows high sensitivity for ozone in the free troposphere and low sensitivity at the ground; therefore it is important to evaluate if assimilation of these observations can improve free tropospheric ozone, and possibly surface ozone. The analyses are validated against independent ozone observations from sondes, MOZAIC1 aircraft and ground based stations (AIRBASE – the European Air quality dataBase) and compared with respect to the free run of CHIMERE. These comparisons show a decrease in error of 6 parts-per-billion (ppb) in the free troposphere over the Frankfurt area, and also a reduction of the root mean square error (respectively bias) at the surface of 19% (33%) for more than 90% of existing ground stations. This provides evidence of the potential of data assimilation of tropospheric IASI columns to better describe the tropospheric ozone distribution, including surface ozone, despite the lower sensitivity. The changes in concentration resulting from the observational constraints were quantified and several geophysical explanations for the findings of this study were drawn. The corrections were most pronounced over Italy and the Mediterranean region, we noted an average reduction of 8–9 ppb in the free troposphere with respect to the free run, and still a reduction of 5.5 ppb at ground, likely due to a longer residence time of air masses in this part associated to the general circulation pattern (i.e. dominant western circulation) and to persistent anticyclonic conditions over the Mediterranean basin. This is an important geophysical result, since the ozone burden is large over this area, with impact on the radiative balance and air quality. 1 Measurements of OZone, water vapour, carbon monoxide and nitrogen oxides by in-service AIrbus airCraft (http://mozaic.aero.obs-mip.fr/web/).
Suspendable macromolecules are responsible for ice nucleation activity of birch and conifer pollen
Authors: Pummer B. G. , Bauer H. , Bernardi J. , Bleicher S. , Grothe H.
Published: March 2012

Abstract. The ice nucleation of bioaerosols (bacteria, pollen, spores, etc.) is a topic of growing interest, since their impact on ice cloud formation and thus on radiative forcing, an important parameter in global climate, is not yet fully understood. Here we show that pollen of different species strongly differ in their ice nucleation behaviour. The average freezing temperatures in laboratory experiments range from 240 to 255 K. As the most efficient nuclei (silver birch, Scots pine and common juniper pollen) have a distribution area up to the Northern timberline, their ice nucleation activity might be a cryoprotective mechanism. Far more intriguingly, it has turned out that water, which has been in contact with pollen and then been separated from the bodies, nucleates as good as the pollen grains themselves. The ice nuclei have to be easily-suspendable macromolecules located on the pollen. Once extracted, they can be distributed further through the atmosphere than the heavy pollen grains and so presumably augment the impact of pollen on ice cloud formation even in the upper troposphere. Our experiments lead to the conclusion that pollen ice nuclei, in contrast to bacterial and fungal ice nucleating proteins, are non-proteinaceous compounds.
Droplet vertical sizing in warm clouds using passive optical measurements from a satellite
Authors: Kokhanovsky A. , Rozanov V. V.
Published: March 2012

Abstract. In this paper a new algorithm for the determination of the vertical distribution of the droplet effective radius in shallow warm clouds is proposed. The method is based on the fact that the spectral top-of-atmosphere reflectance in the near IR spectral range depends on the vertical profile of the effective radius of droplets. The retrieval is based on the optimal estimation method and direct radiative transfer calculations of respective weighting functions. The applications of the method both to synthetic and satellite data are presented. An important feature of the method is the fact that the cloud optical thickness and cloud effective radius are found using the standard homogeneous cloud retrieval and then the retrievals are improved assuming the type of the droplet effective radius profile.
Climatically-controlled siliceous productivity in the eastern Gulf of Guinea during the last 40 000 yr
Authors: Crosta X. , Romero O. E. , Ther O. , Schneider R. R.
Published: March 2012

Abstract. Opal content and diatom assemblages were analysed in core GeoB4905-4 to reconstruct siliceous productivity changes in the eastern Gulf of Guinea during the last 40 000 yr. Opal and total diatom accumulation rates presented low values over the considered period, except during the Last Glacial Maximum and between 15 000 calendar years Before Present (15 cal. ka BP) and 5.5 cal. ka BP, the so-called African Humid Period, when accumulation rates of brackish and freshwater diatoms at the core site were highest. Conversely, accumulation rates of windblown diatoms exhibited an opposite pattern with higher values before and after the African Humid Period and greatest values during Heinrich Events, the Younger Dryas and since 5.5 cal. ka BP. Our results demonstrate that siliceous productivity in the eastern Gulf of Guinea was directly driven by the nutrient load from local rivers, whose discharges were forced by precipitation changes over western Equatorial Africa and/or modification of the fluvio-deltaic systems forced by sea level changes. Precipitation in this region is controlled by the West African monsoon which is, in turn, partly dependent on the presence and intensity of the Atlantic Cold Tongue (ACT). Our results therefore suggest that the ACT was weakened, warmer trade winds were less vigorous, and cloud convection and precipitation were greater during the AHP though centennial-to-millennial timescale dry events were observed at ∼10 cal. ka BP, ∼8.5 cal. ka BP and ∼6 cal. ka BP. Conversely, the ACT was more intense, trade winds were more vigorous and African climate was more arid during H1, the Younger Dryas and after 5.5 cal. ka BP into the present.
Soil parameters estimation over bare agriculture areas from C-band polarimetric SAR data using neural networks
Authors: Baghdadi N. , Cresson R. , El Hajj M. , Ludwig R. , La Jeunesse I.
Published: March 2012

Abstract. The purpose of this study was to develop an approach to estimate soil surface parameters from C-band polarimetric SAR data in the case of bare agricultural soils. An inversion technique based on Multi-Layer Perceptron (MLP) neural networks was introduced. The neural networks were trained and validated on a noisy simulated dataset generated from the Integral Equation Model (IEM) on a wide range of surface roughness and soil moisture, as it is encountered in agricultural contexts for bare soils. The performances of neural networks in retrieving soil moisture and surface roughness were tested for several inversion cases in using or not a priori knowledge on soil parameters. The inversion approach was then validated in using RADARSAT-2 images in polarimetric mode. The introduction of expert knowledge on the soil moisture (dry to wet soils or very wet soils) improves the soil moisture estimates whereas the precision on the surface roughness estimation remains unchanged. Moreover, the use of polarimetric parameters α1 and anisotropy were used to improve the soil parameters estimates. These parameters provide to neural networks the probable ranges of soil moisture (lower or higher than 0.30 cm3 cm−3) and surface roughness (lower or higher than 1.5 cm). Soil moisture can be retrieved correctly from C-band SAR data by using the neural networks technique. Soil moisture errors were estimated at about 0.098 without a priori information on soil parameters and 0.065 cm3 cm−3 (RMSE) applying a priori information on the soil moisture. The retrieval of surface roughness is possible only for low and medium values (lower than 2 cm). Results show that the precision on the soil roughness estimates was about 0.7 cm. For surface roughness lower than 2 cm, the precision on the soil roughness is better with a RMSE about 0.5 cm. The use of polarimetric parameters improves only slightly the soil parameters estimates.
The strength and permeability of tuffisite-bearing andesite in volcanic conduits
Authors: Kolzenburg S. , Heap M. J. , Lavallée Y. , Russell J. K. , Meredith P. G. , Dingwell D. B.
Published: March 2012

Abstract. Tuffisites result from volcanically-induced subsurface fragmentation, transport and deposition, and are common in explosive volcanic environments. Their study provides direct insight to explosive volcanic processes operating within volcanic conduits. Here we report the influence of tuffisite veins on the fundamental physical properties of andesitic rocks. We find that: (1) strength is unaffected by the presence and/or orientation of tuffisites, (2) permeability doubles when tuffisites are oriented favorable (45 degrees to fluid flow), and (3) seismic wave velocities show a continuous increase with depth, independent of vein orientation. Although the influence of tuffisites on andesitic rock properties is modest, we emphasize that the material tested represents the post-eruptive state of tuffisite. Thus, these results delineate the upper boundary of strength and lower boundary of permeability and porosity. All evidence suggests that tuffisites become compacted and lithified on relatively short time scales, restoring the strength of the rock to their initial host rock values.
An analysis of the information behaviors, goals, and intentions of frequent Internet users: Findings from online activity diaries
Authors: St. Jean Beth , Rieh Soo Young , Kim Yong-Mi , Yang Ji Yeon
Published: March 2012

Using a method that combines the Experience Sampling Method (Kubey, et al., 1996) and the diary survey method, we surveyed frequent Internet users about their online activities, along with their interest, confidence, and satisfaction in regard to these activities. A link to an online survey was sent to respondents five times a day for three consecutive days. The results reported here are based on 2,656 diary forms submitted by 417 respondents. Through inductive analysis of respondents’ open–ended accounts of their activities, we identified four information activity dimensions — information object, information behavior, goal, and intention. The results reveal that younger respondents were more likely than older respondents to mention that they engage in online activities with the intention of sharing or evaluating information, while older respondents more frequently mentioned the intentions of gathering data and keeping up to date. Respondents reported spending more time on traditional types of online activities (such as reading) and were more confident in their ability to conduct these types of activities. However, they also reported spending considerable amounts of time on more participatory types of activities, such as creating content and commenting on content. Furthermore, they often rated their interest and satisfaction levels higher when their goals and intentions for their activities were more social in nature and thus more characteristic of Web 2.0 activities, such as connecting with people, self–expression, and sharing. Respondents’ goals and intentions for their activities, as well as their interest, confidence, and satisfaction with various types of online activities, along with the relative amount of time they spent on various types of online activities and the locations from which they conducted these activities, all proved to be important factors to consider when attempting to reach a better understanding of people’s online activities. The contribution of this study lies in the unique data collection and analysis methods that we used in order to reach a better understanding of their online activities across multiple information activity dimensions.
Assessment of dialysis adequacy guidelines implementation in a developing country
Authors: Maoujoud Omar , Bahadi Abdelali , Zajjari Yassir , Ahid Samir , Aatif Taoufiq , Oualim Zouhir
Published: March 2012

Dialysis adequacy has been shown to have a significant impact on patient survival, but there are few data concerning the adequacy of the delivered hemodialysis dose in developing countries. To describe the level of implementation of dialysis practice guidelines in a dialysis center in Morocco, we retrospectively reviewed our 1-year experience of managing chronic hemodialysis patients (CHP), from May 2009 to May 2010. Demographic and biochemical data were collected, and the percentage of patients achieving targets recommended by the NKF-KDOQI guidelines were calculated. Our data suggests that dialysis units in a developing country can achieve current guidelines targets for dialysis adequacy, however, our results are not generalizable to all dialysis centers in Morocco.
Modulation of Bovine Chondrocyte Metabolism by Free Periosteal Grafts in Vitro
Authors: Steinhagen Joern , Niggemeyer Oliver , Bruns Juergen , Klebig Florian , Fuerst Martin , Ruether Wolfgang , Schuenke Michael , Kurz Bodo
Published: March 2012

Purpose

Autologous chondrocyte transplantation (ACT) is an established method in cartilage repair. Although long-term results show durable repair of isolated cartilage defects, some problems still remain. Since hypertrophy of the transplanted periosteum is a common problem, alternatives for periosteum are in demand. Periosteal grafts have been reported to stimulate neochondrogenesis via paracrine effects. The objective of this study was to evaluate the modulation of chondrocyte metabolism by periosteal grafts in vitro.

Methods

Periosteal explants and articular chondrocytes obtained from slaughtered adult cattle were co-cultured in a newly established perfusion system. The experimental groups were: 1. monocultured chondrocytes; 2. chondrocytes cultured with synovial supernatants; 3. chondrocytes cultured with periosteal supernatants; 4. chondrocytes co-cultured with periosteal explants.

Results

Chondrocyte proliferation, evaluated by measuring total DNA content, was prolongated by periosteal and synovial explants. Immunocytochemical staining of collagen type II was stronger in monoculture than in co-culture. Protein biosynthetic activity estimated by [3H]-proline incorporation, as well as extracellular matrix deposition for collagen type II, were reduced by periosteal and synovial explants. Additionally, co-culturing led to a decrease in aggrecan synthesis and release. The inhibiting effects were significantly stronger when cellular chondrocyte-periosteal cross-talk was made possible via paracrine effects.

Conclusions

The results of our study suggest a catabolic effect of periosteal explants on isolated chondrocytes in vitro. Further investigations are necessary whether periosteum in ACT is dispensable.
Performance Prediction of Solar Adsorption Refrigeration System by Ann
Authors: Baiju V. , Muraleedharan C.
Published: March 2012

This paper proposes a new approach for the performance analysis of a single-stage solar adsorption refrigeration system with activated carbon-R134a as working pair. Use of artificial neural network has been proposed to determine the performance parameters of the system, namely, coefficient of performance, specific cooling power, adsorbent bed (thermal compressor) discharge temperature, and solar cooling coefficient of performance. The ANN used in the performance prediction was made in MATLAB (version 7.8) environment using neural network tool box.In this study the temperature, pressure, and solar insolation are used in input layer. The back propagation algorithm with three different variants namely Scaled conjugate gradient, Pola-Ribiere conjugate gradient, and Levenberg-Marquardt (LM) and logistic sigmoid transfer function were used, so that the best approach could be found. After training, it was found that LM algorithm with 9 neurons is most suitable for modeling solar adsorption refrigeration system. The ANN predictions of performance parameters agree well with experimental values with R2 values close to 1 and maximum percentage of error less than 5%. The RMS and covariance values are also found to be within the acceptable limits.
Postmortem Health and Pollution Investigations on Harbor Seals (Phoca vitulina) of the Islands Helgoland and Sylt
Authors: Kakuschke Antje , Gandrass Juergen , Luzardo O. P. , Boada L. D. , Zaccaroni Annalisa , Griesel Simone , Grebe Mechthild , Pröfrock Daniel , Erbsloeh Hans-Burkhard , Valentine-Thon Elizabeth , Prange Andreas , Kramer Katharina
Published: March 2012

Helgoland and Sylt are important centers of tourism in the North Sea. Harbor and grey seals are one reason for the attraction of these islands. However, little is known about these local seal groups. The present postmortem health and pollution study describes a multiparameter investigation of five ill harbor seals which were shot for animal welfare reasons. Firstly, results of pathology and blood investigations support the bad prognosis of survival made in the field. Signs of inflammation in organs, malnutrition, a high-stress level, and reduced thyroid activity were found. Secondly, metal and organic contaminants were investigated. Metal pollutants in blood, liver, muscle, and kidney tissue were not elevated. Lead and mercury concentrations showed a decreased level compared to former studies. Additionally, interesting insights were found for several organic contaminants in comparison with other studies. The Helgoland seals may be influenced by the contaminants of the Elbe plume.
Does 3D Ultrasound Enhance the Diagnosis of Bladder Tumours in Patients with Haematuria?
Authors: Silva-Ramos Miguel , Louro Nuno , Versos Rui , Cavadas Victor , Marcelo Filinto
Published: March 2012

Purpose. Bladder cancer is a frequent cause of haematuria in elderly patients, and bladder ultrasound (US) is a valuable tool in diagnosing these malignancies. We examined the accuracy of 3D bladder US in diagnosing bladder tumors in patients with haematuria. Patients and Methods. Twenty-one patients observed in the emergency department for haematuria underwent a kidney and bladder US. Patients with normal or uncertain bladder US findings underwent a 3D US and a cystoscopy. Results. In 5 (23.8%) patients, the 3D US detected bladder tumours not seen in 2D US. All these patients were found to have bladder tumours on cystoscopy. Another 5 (23.8%) patients with uncertain findings on 2D US had normal 3D US and cystoscopy. 3D US showed a sensitivity of 83.3% and a specificity of 100% with a positive predicted value and negative predictive values of 100% and 93.8%, respectively. Conclusion. 3D US was more sensitive than 2D US in diagnosing bladder tumours in patients with haematuria.
The Born Formula Describes Enthalpy of Ions Solvation
Authors: Bazhin Nikolai
Published: March 2012

The process of ion solvation has been studied in the reversible system using the Van't Hoff equilibrium box. It is shown that the Born formula for solvation energy describes a change in enthalpy rather than in Gibbs energy.
Molecular Mechanisms of Cytotoxicity and Apoptosis Induced by Inorganic Fluoride
Authors: Agalakova Natalia Ivanovna , Gusev Gennadii Petrovich
Published: March 2012

Fluoride (F) is ubiquitous natural substance and widespread industrial pollutant. Although low fluoride concentrations are beneficial for normal tooth and bone development, acute or chronic exposure to high fluoride doses results in adverse health effects. The molecular mechanisms underlying fluoride toxicity are different by nature. Fluoride is able to stimulate G-proteins with subsequent activation of downstream signal transduction pathways such as PKA-, PKC-, PI3-kinase-, Ca2+-, and MAPK-dependent systems. G-protein-independent routes include tyrosine phosphorylation and protein phosphatase inhibition. Along with other toxic effects, fluoride was shown to induce oxidative stress leading to excessive generation of ROS, lipid peroxidation, decrease in the GSH/GSSH ratio, and alterations in activities of antioxidant enzymes, as well as to inhibit glycolysis thus causing the depletion of cellular ATP and disturbances in cellular metabolism. Fluoride triggers the disruption of mitochondria outer membrane and release of cytochrome c into cytosol, what activates caspases-9 and -3 (intrinsic) apoptotic pathway. Extrinsic (death receptor) Fas/FasL-caspase-8 and -3 pathway was also described to be implicated in fluoride-induced apoptosis. Fluoride decreases the ratio of antiapoptotic/proapoptotic Bcl-2 family proteins and upregulates the expression of p53 protein. Finally, fluoride changes the expression profile of apoptosis-related genes and causes endoplasmic reticulum stress leading to inhibition of protein synthesis.
Pollen morphology of Quercus (subgenus Quercus, section Quercus) in Iran and its systematic implication
Authors: Panahi Parisa , Pourmajidian Mohammad R. , Fallah Asghar , Pourhashemi Mehdi
Published: March 2012

For the first time, pollen morphology of 9 (4 spp. and 5 subspp.) taxa representing lobed leaved oaks of Iran in the family of Fagaceae has been examined and illustrated using light microscopy and scanning electron microscopy of acetolysed material. Detailed pollen morphological characteristics are given for Quercus section. The pollen grains are single, isopolar, radially symmetrical, tricolpate, tricolporoidate or tricolporate. Pollens were studied to show all possible characteristics like shape, size, apertures, wall thickness, etc., with special reference to the specific features of each pollen type such as structural, sculptural and suprasculptural patterns. There is considerable variation in pollen morphology between taxa so that, three types of pollen shape, five types of structural pattern, two types of sculptural pattern, five types of suprasculptural pattern and three types of perfora distribution are defined. Furthermore, the relationship between pollen morphology and taxonomy is discussed. Overall, pollen characters are shown to be a useful and informative tool for assessing taxonomic position within Quercus section in Iran.
A diáspora africana na América Latina, tolerância opressiva e perspectivas de transformação
Authors: Oliveira Dennis De
Published: March 2012

A violência étnico-racial é o elemento fundante do modelo de relações sócio-políticas na América Latina. Diante disto, os mecanismos de poder e resistência se expressam em uma práxis de caráter racial, constituindo arquétipos como o mestiço que, de forma ambivalente, tanto servem para os projetos de subjugação política como determinados projetos de afirmação nacional. É no campo dos embates étnico-raciais que também surgem as possibilidades de subjetividades políticas alternativas no continente.
Mídia e propaganda racista: como os mass media constroem a imagem da realidade social – uma leitura do genocídio Ruanda
Authors: Couto Andréia Terzariol
Published: March 2012

Este artigo tem por objetivo analisar como os mass media constroem a imagem da realidade social a partir de uma interpretação sobre o genocídio Ruanda, verificando como a propaganda racista teve um papel fundamental no desencadeamento dos fatos que levaram ao genocídio. A orientação teórica desse artigo, dentro dos limites que ele possui, busca uma tentativa de análise a partir da questão da identidade cultural, discutida por Hall (2003), e como um grande número de elementos de uma nação, que a princípio deveriam compartilhar de uma identidade cultural comum a partir de um determinado momento, passam a propagar o extermínio de outros.
A New Paradigm for Materials Discovery: Heuristics‐Assisted Combinatorial Chemistry Involving Parameterization of Material Novelty
Authors: Park Woon Bae , Shin Namsoo , Hong Kun‐Pyo , Pyo Myoungho , Sohn Kee‐Sun
Published: March 2012

The combinatorial chemistry (combi‐chem) of inorganic functional materials has not yet led to the discovery of commercially interesting materials, in contrast to the many successful discoveries of heterogeneous catalysts leading to commercialization. Novel materials for practical use are likely hidden in the multicompositional search space that contains an infinite number of possible stoichiometries, as well as a large number of well‐known materials. To discover new, inorganic luminescent materials (phosphors) from the SrO‐CaO‐BaO‐La2O3‐Y2O3‐Si3N4‐Eu2O3 search space, heuristics optimization strategies, such as the non‐dominated‐sorting genetic algorithm (NSGA) and particle swarm optimization (PSO) are coupled with high‐throughput experimentation (HTE) in such a manner that the experimental evaluation of fitness functions for the NSGA and PSO is accomplished by the HTE. The proposed strategy also involves the parameterization of the material novelty to avoid systematically a futile convergence on well‐known, already‐established materials. Although the process starts with random compositions, we finally converge on a novel, single‐phase, yellow‐green‐emitting luminescent material, La4–xCaxSi12O3+xN18−x:Eu2+, that has strong potential for practical use in white light‐emitting diodes (WLEDs).
Nanowrinkled and Nanoporous Polyethylene Membranes Via Entanglement Arrangement Control
Authors: Uehara Hiroki , Tamura Takuya , Kakiage Masaki , Yamanobe Takeshi
Published: March 2012

Crystalline homopolymers, including polyethylene (PE), which has the simplest architecture, form a nanometer‐sized combination of crystalline and amorphous components, but their arrangement control, similar to self‐assembled phase‐separation of block‐copolymers, is usually difficult. However, molecular entanglements trapped between crystalline and amorphous components of homopolymers coincide with the segmental linking points on the interfaces of the microphase separation for block copolymers. Nanowrinkled PE membranes are prepared with a network of 30 nm‐thick homogeneous lamellae using a novel entanglement control technique composed of biaxial melt‐drawing and melt‐shrinking procedures, which are limited for highly entangled ultrahigh molecular weight materials. Such a network arrangement of nanowrinkling lamellae spreading on membrane surface and also across the membrane thickness improves the mechanical properties of both tensile strength and tearing strength. Subsequent cold‐drawing causes delamination of the lamellar interfaces, leading to the resultant nanoporous morphology composed of passing‐through channels that are several tens of nanometers in diameter, without any solvent processing.
The Iridium‐Catalyzed Synthesis of Symmetrically and Unsymmetrically Alkylated Diamines under Mild Reaction Conditions
Authors: Michlik Stefan , Hille Toni , Kempe Rhett
Published: March 2012

An iridium catalyst – stabilized by an anionic P,N ligand – was used for the symmetrical and unsymmetrical monoalkylation of para‐, meta‐, and ortho‐benzenediamines. Benzyl and aliphatic alcohols were used as alkylating reagents. 28 derivatives were synthesized. 14 of them are new compounds. Furthermore, the alkylation of the pharmacological important diamine Dapson® (dapsone) is described. 14 dapsone derivatives were synthesized among them 9 new compounds.
One‐Pot Synthesis of Biaryl Lactones by Sonogashira Cross‐Coupling Reactions of 4‐Chloro‐3‐formylcoumarin and Subsequent Domino [5+1] Cyclization/Deacetylation Reactions with 1,3‐Dicarbonyl Compounds
Authors: Iaroshenko Viktor O. , Abbasi Muhammad S. A. , Villinger Alexander , Langer Peter
Published: March 2012

Biaryl lactones were prepared by a new palladium(0) and base‐catalyzed one‐pot reaction of 4‐chloro‐3‐formylcoumarin with alkynes and 1,3‐dicarbonyl compounds.
Copper (I) Iodide‐Catalyzed One‐Step Preparation of Functionalized Allenes from Terminal Alkynes: Amine Effect
Authors: Kuang Jinqiang , Luo Hongwen , Ma Shengming
Published: March 2012

An efficient one‐step synthesis of functionalized allenes from readily available functionalized terminal alkynes and aldehydes by applying the effect of a dialkylamine has been developed. The protocol is catalyzed by copper(I) iodide and the dialkylamine is believed to play a very important role in the transformation.
A Highly Efficient Palladium‐Catalyzed One‐Pot Synthesis of Unsymmetrical Aryl Alkyl Thioethers under Mild Conditions in Water
Authors: Wang Liang , Zhou Wei‐You , Chen Sheng‐Chun , He Ming‐Yang , Chen Qun
Published: March 2012

A palladium‐catalyzed, one‐pot synthesis of unsymmetrical aryl alkyl thioethers involving aryl halides (aryl bromides and chlorides), thiourea and alkyl bromides has been realized under mild conditions (room temperature to 50 °C) in water with polyoxyethanyl α‐tocopheryl sebacate (PTS) as amphiphile. The PTS/water could be recycled in up to eight runs without an obvious change in its activity.
Ontogeny of Proteolytic Signaling and Antioxidant Capacity in Fetal and Neonatal Diaphragm
Authors: Song Yong , Jane Pillow J.
Published: March 2012

Although upregulation of protein degradation pathways contributes to the development of muscle weakness in response to muscle injury and inflammation in the adult diaphragm, less is known about the preterm diaphragm. Muscle development during the antenatal and early postnatal periods normally results in net growth. However, the structural and functional immaturity of the preterm diaphragm may predispose it to injury and inflammation induced by adverse antenatal and postnatal exposures. Characterization of the ontogeny of diaphragm protein degradation pathways in early life is essential to recognize altered signaling pathways under pathologic conditions in preterm babies. We assessed the relative role of the major proteolytic pathways and antioxidant capacity during muscle maturation in ovine fetuses and lambs from 75 days to 200 days postconceptual age. Gene expression and protein content of calpain and caspase 3 exhibited a similar profile with advancing gestation, increasing from 75 days to 100 days/128 days and subsequently decreasing gradually toward the end of gestation. In contrast, ubiquitin conjugating and ligase genes did not change during gestation. All proteolytic genes examined (except Ubiquitin) were upregulated rapidly after delivery, with a similar developmental trend observed in calpain II protein content as well as calpain protease activity. In contrast, antioxidant gene expression demonstrated a steady increase from 75 days gestation to 24 hr after birth, followed by a significant reduction at 7 weeks of postnatal age (P ≤ 0.002). The proteolytic signaling and antioxidant capacity patterns reflect the adaptive process to metabolic change and muscle maturity with development. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Reaction of Frustrated Lewis Pairs with Ketones and Esters
Authors: Xu Bao‐Hua , Yanez Raul Alfonso Adler , Nakatsuka Hiroshi , Kitamura Masato , Fröhlich Roland , Kehr Gerald , Erker Gerhard
Published: March 2012

The frustrated Lewis pair (FLP) Mes2PCH2CH2B(C6F5)2 (1) reacts with an enolizable conjugated ynone by 1,4‐addition involving enolate tautomerization to give an eight‐membered zwitterionic heterocycle. The conjugated endione PhCO‐CHCH‐COPh reacts with the intermolecular FLP tBu3P/B(C6F5)3 by a simple 1,4‐addition to an enone subunit. The same substrate undergoes a more complex reaction with the FLP 1 that involves internal acetal formation to give a heterobicyclic zwitterionic product. FLP 1 reacts with dimethyl maleate by selective overall addition to the CC double bond to give a six‐membered heterocycle. It adds analogously to the triple bond of an acetylenic ester to give a similarly structured six‐membered heterocycle. The intermolecular FLP P(o‐tolyl)3/B(C6F5)3 reacts analogously with acetylenic ester by trans‐addition to the carbon–carbon triple bond. An excess of the intermolecular FLP tBu3P/B(C6F5)3, which contains a more nucleophilic phosphane, reacts differently with acetylenic ester examples, namely by OC(alkyl) bond cleavage to give the {R‐CO2[B(C6F5)3]2−}[alkyl‐PtBu3+] salts. Simple aryl or alkyl esters react analogously by using the borane‐stabilized carboxylates as good leaving groups. All essential products were characterized by X‐ray diffraction.
SN1‐Type Substitution Reactions of N‐Protected β‐Hydroxytyrosine Esters: Stereoselective Synthesis of β‐Aryl and β‐Alkyltyrosines
Authors: Wilcke David , Herdtweck Eberhardt , Bach Thorsten
Published: March 2012

The title compounds were prepared by aldol reaction of anisaldehyde and the respective N,N‐dibenzyl glycinates. Deprotection of the nitrogen atom with Pearlman’s catalyst delivered the unprotected β‐hydroxytyrosine esters, which were further N‐protected as N,N‐phthaloyl (Phth) and N‐fluorenylmethylcarbonyloxy (Fmoc) derivatives. The Friedel–Crafts reaction with various arenes was studied employing these alcohols as electrophiles. It turned out that the facial diastereoselectivitiy depends on the nitrogen protecting group and on the ester group. The unprotected substrates (NH2) gave preferentially syn‐products but the anti‐selectivity increased when going from NHFmoc over NPhth to NBn2. If the ester substituent was varied the syn‐preference increased in the order Me <Et <iPr. The reactions were shown to be fully stereoconvergent and proceeded under kinetic product control. A model is suggested to explain the facial diastereoselectivity based on a conformationally locked benzylic cation intermediate. The reactions are preparatively useful for the N‐unprotected isopropyl ester, which gave Friedel–Crafts alkylation products with good syn‐selectivity (anti/syn=21:79 to 7:93), and for the N,N‐dibenzyl‐protected methyl ester, which led preferentially to anti‐products (anti/syn=80:20 to >95:5). Upon acetylation of the latter compound to the respective acetate, Bi(OTf)3‐catalyzed alkylation reactions became possible, in which silyl enol ethers served as nucleophiles. The respective alkylation products were obtained in high yield and with excellent anti‐selectivitiy (anti/syn≥95:5).
Max Planck – ein Gegner des Christentums? Die Debatte um Plancks Haltung zur Religion nach dem Zweiten Weltkrieg
Authors: Löhr Gebhard
Published: March 2012

Max Planck – an Adversary of Christianity? The Debate About Planck's Attitude Towards Religion after World War II. The article discusses a debate which unfolded in the early 1950s and 1960s between East German Marxist philosophers and historians of science and West German theologians and scientists. The subject treated was the attitude towards religion of famous physicist Max Planck who had died a few years earlier, in 1947. The article analyses the different positions of the contributors, mainly with a view to developing a categorial framework usable in descriptions and analyses of the religious attitudes of natural scientists. Moreover the different stages of the debate are outlined in order to exhibit their connections to the larger historical context, i.e. the unfolding of the cold war. In the light of this the debate can be regarded as a religious or ideological war, albeit a cold one, on German soil, which fortunately did not escalate into a hot conflict. It ended, as can be illustrated in a late contribution to the debate, with the collapse of the GDR in 1989 or shortly thereafter.
Eine analytische Bildpraxis. Die pathologisch‐anatomischen Zeichnungen Jean Cruveilhiers in ihrem Verhältnis zu klinischen Beobachtungen
Authors: Engelmann Lukas
Published: March 2012

An Analytical Visualization Practice. The Pathological‐anatomical Illustrations of Jean Cruveilhier in Relation to Clinical Observations. The article examines the meaning and function of medical illustrations in the famous Atlas Anatomie pathologique, published by the French surgeon Jean Cruveilhier (1791–1874). By tracing the complex representation of pathological entities both back to the visual tradition of anatomy and the semiotic tradition of case descriptions and case histories, the article identifies the visualization technique of Cruveilhier as an analytical practice. The illustration of pathological anatomy gains a functional diagnostic quality when bound to case descriptions and clinical histories. The Atlas serves thereby as a sample to trace the genealogies of a clinical visualization practice in characteristic images that is both engaged with an individual case and classificational tasks.