bluuebunny/crossref_metadata_2025 huggingface dataset:
Imidazol(in)ium‐2‐Carboxylates as N‐Heterocyclic Carbene Ligand Precursors for Ruthenium Metathesis Initiators
Authors: Sauvage Xavier , Demonceau Albert , Delaude Lionel
Published: July 2010

Summary: Imidazol(in)ium‐2‐carboxylates were used as N‐heterocyclic carbene (NHC) ligand precursors to convert the [RuCl2(p‐cymene)]2 dimer into three ruthenium‐arene complexes of the [RuCl2(p‐cymene)(NHC)] type. The decarboxylation of NHC · CO2 betaines also provided a convenient synthetic path to prepare five well‐known ruthenium‐NHC catalysts for olefin metathesis and related reactions, including the second generation Grubbs and Hoveyda–Grubbs catalysts, via ligand exchange with phosphine‐containing, first generation ruthenium‐benzylidene or indenylidene complexes. Both procedures are particularly attractive from a practical point of view, because NHC · CO2 adducts are stable zwitterionic compounds that can be stored and handled with no particular precautions.
Ring‐Opening Metathesis Polymerization of Cyclooctyne Employing Well‐Defined Tungsten Alkylidyne Complexes
Authors: Lysenko Sergej , Haberlag Birte , Wu Xian , Tamm Matthias
Published: July 2010

Summary: The ring‐opening metathesis polymerization of cyclooctyne was studied was studied in the presence of catalytic amounts of the tungsten alkylidyne complexes [RCW(NImtBu){OCMe(CF3)2}2] (1a: R = CMe3, 1b: R = Ph). The resulting polymers show relatively narrow polydispersities with the PDI ranging from 1.2 to 2.4. Treatment of 1b with cyclooctyne in dilute toluene or hexane solution afforded only low molecular weight oligomers. The mass spectra of these oligomers indicate the existence of macrocycles of the formula [C(CH2)6C]n (n = 3–9). In contrast, reactions at high substrate concentration led to mixtures of cyclic oligomers and linear polymers, which is probably a result of ring‐chain equilibria, established in agreement with the Jacobson‐Stockmayer theory of macrocyclization. In contrast, treatment of neat cyclooctyne with a catalytic amount of the catalyst produced medium molecular weight polymers in good yields.
Decomposition of mixtures' spectra by multivariate curve resolution of rapidly acquired TOCSY experiments
Authors: Castellanos Eddy Rocío Rey , Wist Julien
Published: July 2010

A method is presented that allows for retrieving 1D spectra of the individual components of a mixture from a sparsely acquired 2D‐TOCSY spectrum. The decomposition of the 2D‐TOCSY data into pure 1D traces is achieved using a non‐negative matrix factorization algorithm, also known as multivariate curve resolution analysis. Here, we show that the algorithm can be applied to data processed in the direct dimension only. Thus, our method can be applied to non‐linearly sampled experiments or data acquired with few indirect points. An example is shown for the spectra of a mixture of six amino acids, acquired in 15 min. Copyright © 2010 John Wiley & Sons, Ltd.
Fast multidimensional localized parallel NMR spectroscopy for the analysis of samples
Authors: Vega‐Vazquez Marino , Cobas Juan Carlos , Martin‐Pastor Manuel
Published: July 2010

A parallel localized spectroscopy (PALSY) method is presented to speed up the acquisition of multidimensional NMR (nD) spectra. The sample is virtually divided into a discrete number of nonoverlapping slices that relax independently during consecutive scans of the experiment, affording a substantial reduction in the interscan relaxation delay and the total experiment time. PALSY was tested for the acquisition of three experiments 2D COSY, 2D DQF‐COSY and 2D TQF‐COSY in parallel, affording a time‐saving factor of 3–4. Some unique advantages are that the achievable resolution in any dimension is not compromised in any way: it uses conventional NMR data processing, it is not prone to generate spectral artifacts, and once calibrated, it can be used routinely with these and other combinations of NMR spectra. Copyright © 2010 John Wiley & Sons, Ltd.
Wenn Wissensträger in den Ruhestand gehen
Authors: Riese Christian
Published: July 2010

Der demografische Wandel macht vor der chemischen Industrie nicht halt:  In den nächsten Jahren werden die über 50‐jährigen die größte Gruppe in vielen Unternehmen sein, und wenn sie in Ruhestand gehen, geht Know‐how verloren.
Systematic evaluation of the miRNA‐ome and its downstream effects on mRNA expression identifies gastric cancer progression
Authors: Tchernitsa Oleg , Kasajima Atsuko , Schäfer Reinhold , Kuban Ralf‐Jürgen , Ungethüm Ute , Györffy Balazs , Neumann Ulf , Simon Eva , Weichert Wilko , Ebert Matthias PA , Röcken Christoph
Published: July 2010

We investigated the differential expression of Dicer and Drosha, as well as that of microRNA (miRNA), in adjacent normal and tumour samples of patients with gastric cancer. The expression of Dicer and Drosha was studied by immunohistochemistry in 332 gastric cancers and correlated with clinico‐pathological patient characteristics. Differential expression of miRNAs was studied using the Invitrogen NCode™ Multi‐Species miRNA Microarray Probe Set containing 857 mammalian probes in a test set of six primary gastric cancers (three with and three without lymph node metastases). Differential expression was validated by RT‐PCR on an independent validation set of 20 patients with gastric cancer. Dicer and Drosha were differentially expressed in non‐neoplastic and neoplastic gastric tissue. The expression of Drosha correlated with local tumour growth and was a significant independent prognosticator of patient survival. Twenty miRNAs were up‐ and two down‐regulated in gastric carcinoma compared with non‐neoplastic tissue. Six of these miRNAs separated node‐positive from node‐negative gastric cancers, ie miR‐103, miR‐21, miR‐145, miR‐106b, miR‐146a, and miR‐148a. Five miRNAs expressed differentially in node‐positive cancers had conserved binding sites for mRNAs differentially expressed in the same set of tumour samples. Gastric cancer shows a complex derangement of the miRNA‐ome, including Dicer and Drosha. These changes correlate independently with patient prognosis and probably influence local tumour growth and nodal spread. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Oestrogen‐induced epithelial–mesenchymal transition of endometrial epithelial cells contributes to the development of adenomyosis
Authors: Chen Yi‐Jen , Li Hsin‐Yang , Huang Chi‐Hung , Twu Nae‐Fang , Yen Ming‐Shyen , Wang Peng‐Hui , Chou Teh‐Ying , Liu Yen‐Ni , Chao Kuan‐Chong , Yang Muh‐Hwa
Published: July 2010

Adenomyosis is an oestrogen‐dependent disease caused by a downward extension of the endometrium into the uterine myometrium. Epithelial–mesenchymal transition (EMT) endows cells with migratory and invasive properties and can be induced by oestrogen. We hypothesized that oestrogen‐induced EMT is critical in the pathogenesis of adenomyosis. We first investigated whether EMT occurred in adenomyotic lesions and whether it correlated with serum 17β‐oestradiol (E2) levels. Immunohistochemistry was performed on adenomyotic lesions and corresponding eutopic endometrium samples from women with adenomyosis. Endometria from women without endometrial disorders were used as a control. In the epithelial component of adenomyotic lesions, vimentin expression was up‐regulated and E‐cadherin expression was down‐regulated compared to the eutopic endometrium, suggesting that EMT occurs in adenomyosis. In adenomyosis, the serum E2 level was negatively correlated with E‐cadherin expression in the epithelial components of the eutopic endometrium and adenomyotic lesions, suggesting the involvement of oestrogen‐induced EMT in endometrial cells. In oestrogen receptor‐positive Ishikawa endometrial epithelial cells, oestrogen induced a morphological change to a fibroblast‐like phenotype, a shift from epithelial marker expression to mesenchymal marker expression, increased migration and invasion, and up‐regulation of the EMT regulator Slug. Raloxifene, a selective oestrogen receptor modulator, abrogated these effects. To determine the role of oestrogen‐induced EMT in the implantation of ectopic endometrium, we xenotransplanted eutopic endometrium or adenomyotic lesions from adenomyosis patients into ovariectomized SCID mice. The implantation of endometrium was oestrogen‐dependent and was suppressed by raloxifene. Collectively, these data highlight the crucial role of oestrogen‐induced EMT in the development of adenomyosis and suggest that raloxifene may be a potential therapeutic agent for adenomyosis patients. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Is there a correlation between the proportion of cells with isodicentric Yp at amniocentesis and phenotypic sex?
Authors: Xu Jie , Siu V. M.
Published: July 2010

Objectives

(1) To present a case with prenatally detected idic Yp. (2) To review literature to assess if there is a correlation between the proportion of amniocytes with idic Yp and phenotypic sex.

Methods

Seventeen cases were reviewed.

Results

Amniocentesis was done due to positive integrated prenatal screening result. Interphase FISH was normal for chromosomes 13, 18, and 21, but mosaic for cell lines with 1 X and 0 to 2 copies of DYZ3, SRY, or DYZ1(Yq12). Amniocytes had 45,X[28]/46,X,idic(Y)(q11.2)[2].ish idic(Y)(DYZ3 + +, SRY + +). An apparently normal female was born at 37 weeks. The umbilical cord had 45,X[50], but cord blood had 45,X[17]/46,X,idic(Y)[31]/47,X,idic(Y)x2[2]. Review of 17 cases showed that 13 cases with 20 to 100% cells with idic Yp all had a male phenotype. Two cases with 3 and 7% of idic Yp cells had a female phenotype. Two cases with 45,X only at prenatal diagnosis but idic Yp detected postnatally were phenotypic male.

Conclusion

(1) We present the first report of prenatally detected idic Yp and Yq12 resulting in an apparently normal female at birth. (2) Finding of > 20% of G‐banded amniocytes with idic Yp in the absence of other indicators of foetal structural anomalies seems to correlate with phenotypically normal male in most cases. Copyright © 2010 John Wiley & Sons, Ltd.
The relationship between first trimester fetal growth, pregnancy‐associated plasma protein A levels and birthweight
Authors: Habayeb O. , Daemen A. , Timmerman D. , De Moor B. , Hackett G. A. , Bourne T. , Lees C. C.
Published: July 2010

Objective

We sought to define the relationship between first trimester fetal growth, pregnancy‐associated plasma protein A (PAPP‐A) levels and birthweight.

Methods

Two‐hundred and one women with repeat first trimester crown‐rump length (CRL) measurements were included. In 194, the first trimester PAPP‐A value was known and in 169 there was complete data including birthweight. Fetal growth curves were derived using functional linear discriminant analysis (FLDA) and growth compared between those with < 10th percentile, 10th to 90th and > 90th percentile PAPP‐A multiple of median (MoM) levels and birthweight percentiles.

Results

Median maternal age was 35 years, gestation at PAPP‐A sampling and of first scan was 11 weeks. Median delivery gestation was 40 weeks and birthweight 3425 g. There was no association between first trimester fetal CRL growth and either PAPP‐A MoM percentile or birthweight percentile. There was a significant positive correlation between PAPP‐A MoM and birthweight percentile (p = 0.0004).

Conclusions

First trimester fetal growth rate is not related to birthweight percentile or first trimester PAPP‐A levels. Irrespective of gestation, a low PAPP‐A is associated with delivery of a smaller baby, and a high PAPP‐A with a larger baby. Copyright © 2010 John Wiley & Sons, Ltd.
Fetal transient occipital bone protuberance during early pregnancy
Authors: Nevo Ori , Bronshtein Moshe
Published: July 2010

Objective

To describe the prenatal sonographic findings and pregnancy outcome of fetuses with transient occipital bone protuberance (TOBP).

Methods

Five fetuses with TOBP were identified at routine 14 to 15 weeks ultrasound. The sonographic examination was repeated during pregnancy and the neonates were examined after birth.

Results

The occipital bone protuberance disappeared by 24 weeks in all five cases, and the postnatal examination of the skull was normal.

Conclusions

Isolated TOBP is rare during early pregnancy. Ultrasound follow‐up is suggested and disappearance of the lesion can be expected in most, if not all the cases with normal skull at birth. Copyright © 2010 John Wiley & Sons, Ltd.
2,2,6,6‐Tetramethylpiperidine‐1‐oxyl‐mediated living mini‐emulsion polymerization of styrene under ambient pressure in a semi‐batch process: effect of ascorbic acid
Authors: Jeng Jauder , Chiu Wen‐Yen
Published: July 2010

2,2,6,6‐Tetramethylpiperidine‐1‐oxyl (TEMPO)‐mediated living mini‐emulsion polymerization of styrene with feeding of an ascorbic acid aqueous solution throughout the polymerization was performed at 90 °C under ambient pressure. The concentrations of sodium dodecylbenzenesulfonate (SDBS) and ascorbic acid were varied to study the shell polymerization mechanism of latex particles and evolution of growing chains. Interactions between SDBS and ascorbic acid and incompatibility between ascorbic acid and styrene were evident from UV‐visible analyses. High hydrophilicity of ascorbic acid in the aqueous phase was proved using a gravimetric method. Accordingly, the formation of a surface barrier on particles was proposed because of the interactions between SDBS and ascorbic acid. For higher SDBS concentration, the surface barrier on the particles was denser. Therefore, the polymerization rate decreased with increasing SDBS concentration. However, the polymerization rate increased with increasing ascorbic acid concentration. This was due to a higher consumption rate of TEMPO by ascorbic acid. Free TEMPO tended to reside in surface zones of the particles because of the surface activity between the aqueous and oil phases. The surface zones were thus the main loci where TEMPO was consumed by ascorbic acid. The estimated number‐average molecular weight (Mn) of growing chains increased in a linear fashion with conversion. This indicated that the growing chains were produced via living mini‐emulsion polymerization. For these growing chains, the estimated Mn and final polydispersity increased with increasing SDBS concentration. This was caused by a decrease in TEMPO concentration in the surface zones of particles with increasing SDBS concentration. The ‘livingness’ of polystyrene was identified by conducting bulk polymerization of chain extension. Based on the results obtained, a shell polymerization mechanism of latex particles was proposed, and living mini‐emulsion polymerization was limited to the surface zones of particles. Copyright © 2010 Society of Chemical Industry
Proteomic analysis of germinating urediniospores of Phakopsora pachyrhizi, causal agent of Asian soybean rust
Authors: Luster Douglas G. , McMahon Michael B. , Carter Melissa L. , Fortis Laurie L. , Nuñez Alberto
Published: July 2010

Phakopsora pachyrhizi is an obligate pathogen that causes Asian soybean rust. Asian soybean rust has an unusually broad host range and infects by direct penetration through the leaf cuticle. In order to understand the early events in the infection process, it is important to identify and characterize proteins in P. pachyrhizi. Germination of the urediniospore is the first stage in the infection process and represents a critical life stage applicable to studies with this obligate pathogen. We have applied a 2‐DE and MS approach to identify 117 proteins from the National Center of Biotechnology Information nonredundant protein database and a custom database of Basidiomycota EST sequences. Proteins with roles in primary metabolism, energy transduction, stress, cellular regulation and signaling were identified in this study. This data set is accessible at http://world‐2dpage.expasy.org/repository/database=0018.
Modern proteomic methodologies for the characterization of lactosylation protein targets in milk
Authors: Arena Simona , Renzone Giovanni , Novi Gianfranco , Paffetti Alessandro , Bernardini Giulia , Santucci Annalisa , Scaloni Andrea
Published: July 2010

Heat treatment of milk induces the Maillard reaction between lactose and proteins; in this context, β‐lactoglobulin and α‐lactalbumin adducts have been used as markers to monitor milk quality. Since some milk proteins have been reported as essential for the delivery of microelements and, being resistant against proteolysis in the gastrointestinal tract, also contributing to the acquired immune response against pathogens and the stimulation of cellular proliferation, it is crucial to systematically determine the milk subproteome affected by the Maillard reaction for a careful evaluation of aliment functional properties. This is more important when milk is the unique nutritional source, as in infant diet. To this purpose, a combination of proteomic procedures based on analyte capture by combinatorial peptide ligand libraries, selective trapping of lactosylated peptides by m‐aminophenylboronic acid‐agarose chromatography and collision‐induced dissociation and electron transfer dissociation MS was used for systematic identification of the lactosylated proteins in milk samples subjected to different thermal treatments. An exhaustive modification of proteins was observed in milk powdered preparations for infant nutrition. Globally, this approach allowed the identification of 271 non‐redundant modification sites in 33 milk proteins, which also included low‐abundance components involved in nutrient delivery, defence response against virus/microorganisms and cellular proliferative events. A comparison of the modified peptide identification percentages resulting from electron transfer dissociation or collision‐induced dissociation fragmentation spectra confirmed the first activation mode as most advantageous for the analysis of lactosylated proteins. Nutritional, biological and toxicological consequences of these findings are discussed on the basis of the recent literature on this subject, emphasizing their impact on newborn diet.
Elucidating the role of Trp105 in the KPC‐2 β‐lactamase
Authors: Papp‐Wallace Krisztina M. , Taracila Magdalena , Wallace Christopher J. , Hujer Kristine M. , Bethel Christopher R. , Hornick John M. , Bonomo Robert A.
Published: July 2010

The molecular basis of resistance to β‐lactams and β‐lactam‐β‐lactamase inhibitor combinations in the KPC family of class A enzymes is of extreme importance to the future design of effective β‐lactam therapy. Recent crystal structures of KPC‐2 and other class A β‐lactamases suggest that Ambler position Trp105 may be of importance in binding β‐lactam compounds. Based on this notion, we explored the role of residue Trp105 in KPC‐2 by conducting site‐saturation mutagenesis at this position. Escherichia coli DH10B cells expressing the Trp105Phe, ‐Tyr, ‐Asn, and ‐His KPC‐2 variants possessed minimal inhibitory concentrations (MICs) similar to E. coli cells expressing wild type (WT) KPC‐2. Interestingly, most of the variants showed increased MICs to ampicillin‐clavulanic acid but not to ampicillin‐sulbactam or piperacillin‐tazobactam. To explain the biochemical basis of this behavior, four variants (Trp105Phe, ‐Asn, ‐Leu, and ‐Val) were studied in detail. Consistent with the MIC data, the Trp105Phe β‐lactamase displayed improved catalytic efficiencies, kcat/Km, toward piperacillin, cephalothin, and nitrocefin, but slightly decreased kcat/Km toward cefotaxime and imipenem when compared to WT β‐lactamase. The Trp105Asn variant exhibited increased Kms for all substrates. In contrast, the Trp105Leu and ‐Val substituted enzymes demonstrated notably decreased catalytic efficiencies (kcat/Km) for all substrates. With respect to clavulanic acid, the Kis and partition ratios were increased for the Trp105Phe, ‐Asn, and ‐Val variants. We conclude that interactions between Trp105 of KPC‐2 and the β‐lactam are essential for hydrolysis of substrates. Taken together, kinetic and molecular modeling studies define the role of Trp105 in β‐lactam and β‐lactamase inhibitor discrimination.
High‐level expression and purification of Cys‐loop ligand‐gated ion channels in a tetracycline‐inducible stable mammalian cell line: GABAAand serotonin receptors
Authors: Dostalova Zuzana , Liu Aiping , Zhou Xiaojuan , Farmer Sarah L. , Krenzel Eileen S. , Arevalo Enrique , Desai Rooma , Feinberg‐Zadek Paula L. , Davies Paul A. , Yamodo Innocent H. , Forman Stuart A. , Miller Keith W.
Published: July 2010

The human neuronal Cys‐loop ligand‐gated ion channel superfamily of ion channels are important determinants of human behavior and the target of many drugs. It is essential for their structural characterization to achieve high‐level expression in a functional state. The aim of this work was to establish stable mammalian cell lines that enable high‐level heterologous production of pure receptors in a state that supports agonist‐induced allosteric conformational changes. In a tetracycline‐inducible stable human embryonic kidney cells (HEK293S) cell line, GABAAreceptors containing α1 and β3 subunits could be expressed with specific activities of 29–34 pmol/mg corresponding to 140–170 pmol/plate, the highest expression level reported so far. Comparable figures for serotonin (5‐HT3A) receptors were 49–63 pmol/mg and 245–315 pmol/plate. The expression of 10 nmol of either receptor in suspension in a bioreactor required 0.3–3.0 L. Both receptor constructs had a FLAG epitope inserted at the N‐terminus and could be purified in one step after solubilization using ANTI‐FLAG affinity chromatography with yields of 30–40%. Purified receptors were functional. Binding of the agonist [3H]muscimol to the purified GABAAR was enhanced allosterically by the general anesthetic etomidate, and purified 5‐hydroxytryptamine‐3A receptor supported serotonin‐stimulated cation flux when reconstituted into lipid vesicles.
Photon‐in photon‐out soft X‐ray spectroscopy for materials science
Authors: Himpsel F. J.
Published: July 2010

A brief overview of the three elements of photon‐in photon‐out spectroscopy is given, i.e., X‐ray absorption spectroscopy (XAS), X‐ray emission spectroscopy (XES), and resonant inelastic X‐ray scattering (RIXS). Key features are emphasized, such as element selectivity and the ability to study electronic states in dilute systems, at buried interfaces, and in a liquid environment. Characteristic applications in the areas of nanomaterials, biomaterials, and photovoltaic materials illustrate these capabilities.
Monitoring, analysis, and filtering system for purifying network traffic of known and unknown malicious content
Authors: shabtai Asaf , Potashnik Dennis , Fledel Yuval , Moskovitch Robert , Elovici Yuval
Published: July 2010

The early detection, alert and response (eDare) framework is presented in this paper. The goal of this framework is to address the risks stemming from malicious software propagating via networks operated by Internet/network service providers (ISP/NSP). To achieve this goal, eDare employs network‐based traffic scanning appliances that enable sanitation of Internet traffic of known malware. Remaining traffic is extracted and various types of algorithms are invoked in an attempt to detect instances of previously un‐encountered malware and to generate a unique and simple byte‐string signature for such malware. That signature is immediately uploaded to the aforementioned network traffic scanners. To augment judgments of the algorithms, human experts are consulted for assistance in classifying files suspected of being malware about which the automatic detection algorithms are not sufficiently decisive. Finally, collaborative feedback and tips from end‐users are meshed into the identification process. This makes tackling of suspect files, whose impact can be assessed on a large, distributed scale, possible. The system incorporates static and behavioral analysis of malware and novel automatic signature generation algorithm. eDare was implemented and tested using an evaluation environment especially developed for that purpose. The results suggest that eDare can detect and remove unknown malware effectively. Copyright © 2010 John Wiley & Sons, Ltd.
Removal of Ar+ beam‐induced damaged layers from polyimide surfaces with argon gas cluster ion beams
Authors: Miyayama Takuya , Sanada Noriaki , Bryan Scott R. , Hammond John S. , Suzuki Mineharu
Published: July 2010

An Ar Gas Cluster Ion Beam (GCIB) has been shown to remove previous Ar+ ion beam‐induced surface damage to a bulk polyimide (PI) film. After removal of the damaged layer with a GCIB sputter source, XPS measurements show minor changes to the carbon, nitrogen and oxygen atomic concentrations relative to the original elemental bulk concentrations. The GCIB sputter depth profiles showed that there is a linear relationship between the Ar+ ion beam voltage within the range from 0.5 to 4.0 keV and the dose of argon cluster ions required to remove the damaged layer. The rate of recovery of the original PI atomic composition as a function of GCIB sputtering is similar for carbon, nitrogen and oxygen, indicating that there was no preferential sputtering for these elements. The XPS chemical state analysis of the N 1s spectra after GCIB sputtering revealed a 17% damage ratio of altered nitrogen chemical state species. Further optimization of the GCIB sputtering conditions should lead to lower nitrogen damage ratios with the elemental concentrations closer to those of bulk PI. Copyright © 2010 John Wiley & Sons, Ltd.
Sonographic estimation of fetal head circumference: how accurate are we?
Authors: Melamed N. , Yogev Y. , Danon D. , Mashiach R. , Meizner I. , Ben‐Haroush A.
Published: July 2010

Objectives

To assess the accuracy of sonographic estimation of fetal head circumference (HC).

Methods

We compared sonographic estimations of fetal HC with actual measurements performed immediately after delivery using 3008 sonographic examinations performed within 3 days prior to delivery. The following measures of accuracy were calculated: correlation with actual HC, systematic error, random error, simple error, mean absolute percentage error and fraction of estimates within 5% of actual HC. Multivariate logistic regression analysis was used to identify factors affecting the accuracy of sonographic HC estimation.

Results

There was a high correlation between sonographic and postnatal measurements of HC (r= 0.845,P< 0.001). Overall, sonographic HC measurements consistently underestimated actual HC measured postnatally (mean simple error, − 13.6 mm; 95% CI, − 13.2 to − 13.9), and the difference increased with gestational age. A high cephalic index (> 0.81) (odds ratio (OR), 0.3; 95% CI, 0.2–0.4), HC > 90thcentile (OR, 0.5; 95% CI, 0.3–0.6), delivery by vacuum extraction (OR, 0.6; 95% CI, 0.4–0.8), gestational week (OR, 0.7; 95% CI, 0.6–0.9) and male fetal gender (OR, 0.8; 95% CI, 0.6–0.9) were associated with decreased sonographic accuracy. At term, breech presentation at the time of sonographic examination was associated with a higher sonographic accuracy compared with vertex presentation (−12.0; 95% CI, − 10.5 to − 13.5 vs. − 13.9 mm; 95% CI, − 13.6 to − 14.3;P= 0.02). The random error was relatively constant, and was unaffected by any of the obstetric factors studied.

Conclusion

Sonographic estimation of HC is associated with significant underestimation compared with the actual postnatal HC. This measurement error may have important clinical implications and should be taken into account in the interpretation of sonographically measured HC. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
Splitting downlink multimedia traffic over WiMAX and WiFi heterogeneous links based on airtime‐balance
Authors: Kim Jong‐Ok , Davis Peter , Ueda Tetsuro , Obana Sadao
Published: July 2010

We investigate the challenge of splitting a traffic flow over WiMAX and WiFi links. For traffic load distribution over heterogeneous RATs (Radio Access Technologies), heterogeneous link resources need to be commonly measured and fairly compared. To this end, an airtime cost model is considered as a common resource measure. The model can be used to estimate channel time consumed for a successful packet transmission. As a traffic split mechanism, an airtime‐balance method is proposed. Using the airtime cost model, the offered traffic load (in Mbps) is converted into airtime cost required for its transmission, and IP packets are distributed to multiple RATs so that airtime is equally balanced between RATs.

We have implemented a practical test‐bed system, including both WiMAX and WiFi systems, and used it to conduct extensive experiments indoor and outdoor. Experimental results confirm that airtime‐balance can achieve an improved flow split to reduce the waiting packets at the reorder buffer of the receiver. Moreover, it could realize a more rapid adaptation to link variations with local measurements, when compared to the RTT‐based method, which also requires extra system overhead due to the use of probe packets. Copyright © 2010 John Wiley & Sons, Ltd.
An interdisciplinary systems approach to study sperm physiology and evolution
Authors: Shi Linda Z. , Nascimento Jaclyn , Botvinick Elliot , Durrant Barbara , Berns Michael W.
Published: July 2010

Optical trapping is a noninvasive biophotonic tool that has been developed to study the physiological and biomechanical properties of cells. The custom‐designed optical system is built to direct near‐infrared laser light into an inverted microscope to create a single‐point three‐dimensional gradient laser trap at the microscope focal point. A real‐time automated tracking and trapping system (RATTS) is described that provides a remote user‐friendly robotic interface. The combination of laser tweezers, fluorescent imaging, and RATTS can measure sperm swimming speed and swimming force simultaneously with mitochondrial membrane potential (MMP). The roles of two sources of adenosine triphosphate in sperm motility/energetics are studied: oxidative phosphorylation, which occurs in the mitochondria located in the sperm midpiece, and glycolysis, which occurs along the length of the sperm tail (flagellum). The effects of glucose, oxidative phosphorylation inhibitors, and glycolytic inhibitors on human sperm motility are studied. This combination of photonic physical and engineering tools has been used to examine the evolutionary effect of sperm competition in primates. The results demonstrate a correlation between mating type and sperm motility: sperm from polygamous (multi‐partner) primate species swim faster and with greater force than sperm from polygynous (single partner) primate species. In summary, engineering and biological systems are combined to provide a powerful interdisciplinary approach to study the complex biological systems that drive the sperm toward the egg. WIREs Syst Biol Med 2011 3 36–47 DOI: 10.1002/wsbm.106

This article is categorized under:

Analytical and Computational Methods > Computational Methods

Physiology > Organismal Responses to Environment
Estrogen receptor‐positive breast cancer: a multidisciplinary challenge
Authors: Zwart Wilbert , Theodorou Vasiliki , Carroll Jason S.
Published: July 2010

Estrogen receptor (ER)‐positive breast cancer research is an ideal example of how systems biology can be applied to better understand a specific clinical issue. By integrating vast data sets from tumor‐derived expression arrays, genome‐wide transcription factor/chromatin interactions, proteomics and computational analyses, we may better understand the concept of breast cancer development, heterogeneity, and its treatment. Resistance to endocrine treatment, such as anti‐estrogens, often occurs and systems biology may prove to be a valuable asset in tailoring treatment for each patient. In such a multidisciplinary setup, it is essential to try and connect these massive data streams with the known pathological background and cell biology. In this review, we describe the current status of such studies and the challenges that are to be met in order to fully understand the concept of anti‐estrogen resistance from a holistic perspective. WIREs Syst Biol Med 2011 3 216–230 DOI: 10.1002/wsbm.109

This article is categorized under:

Models of Systems Properties and Processes > Cellular Models

Laboratory Methods and Technologies > Genetic/Genomic Methods

Translational, Genomic, and Systems Medicine > Translational Medicine
Ratification of IATSIC/WHO’s Guidelines for Essential Trauma Care Assessment in the South American Region
Authors: Aboutanos Michel B. , Mora Francisco , Rodas Edgar , Salamea Juan , Parra Marcelo Ochoa , Salgado Estuardo , Mock Charlie , Ivatury Rao
Published: July 2010

Background

The purpose of the present study was to evaluate the usefulness of the International Association for Trauma Surgery and Intensive Care (IATSIC)/World Health Organization (WHO)’s Guidelines for Essential Trauma Care (EsTC Guidelines) in providing an internationally applicable and standardized template to assess trauma care capabilities in the South American Region.

Methods

Field assessment was conducted in seven provinces (urban and rural, pop. 2,239,509) and 24 facilities (5 large hospitals (LH); 15 small hospitals (SH); 4 basic hospitals (BH)) in Ecuador using EsTC criteria. A total of 260 individual items in Human Resources (HR– availability, clinical knowledge, skills) and physical resources (PR) were evaluated via inspection, review of local statistics, and administrative and staff interviews. EsTC was evaluated on a scale as follows: 0 (absent); 1(inadequate; < 50%); 2 (partly adequate > 50%); 3 (adequate–100%).

Results

210,045 Emergency Department (ED) visits and 61,365 (29%) ED trauma visits were recorded (incidence rate 2,740/100,000 population). Deficits were noted in prehospital trauma care (inadequate coordination, communication), education and training (ATLS < 30%, TNCC 0%), facility based trauma care (poor physical resources [PR] and human resources [HR]), and quality assurance (1/27 hospitals).

Conclusions

The IATSIC/WHO EsTC Guidelines provide a simple and useful template to assess trauma care capability in variable facilities and international settings, and they could serve as a valuable tool for trauma system development. Endorsement of EsTC Guidelines by the Panamerican Health Organization and lead trauma societies (the Panamerican Trauma Society) should be considered.
Insulin modulates induction of glucose‐regulated protein 78 during endoplasmic reticulum stress via augmentation of ATF4 expression in human neuroblastoma cells
Authors: Inageda Kiyoshi
Published: July 2010

The effect of insulin on endoplasmic reticulum (ER) stress was investigated. Insulin protected cell death induced by ER stress and increased glucose‐regulated protein 78 (GRP78) mRNA and protein levels. Insulin also significantly increased activating transcription factor‐4 (ATF4) protein in the nucleus, which was inhibited by LY294002, a phosphatidylinositol 3‐kinase (PI‐3 kinase) inhibitor. The increase of ATF4 protein by insulin was not due to transcriptional or translational up‐regulation but to a post‐translational mechanism. Knockdown of ATF4 by siRNA significantly inhibited GRP78 induction by insulin. These results indicate that insulin modulated ER stress‐induced GRP78 expression occurs via ATF4 up‐regulation.
Scattering from Black Holes
Authors: Futterman J. A. H. , Handler F. A. , Matzner Richard Alfred
Published: July 2010

This book investigates the propagation of waves in the presence of black holes. Astrophysical black holes may eventually be probed by these techniques. The authors emphasise intuitive physical thinking in their treatment of the techniques of analysis of scattering, but alternate this with chapters on the rigourous mathematical development of the subject. High and low energy limiting cases are treated extensively and semi-classical results are also obtained. The analogy between Newtonian gravitational scattering and Coulomb quantum mechanical scattering is fully exploited. The book introduces the concepts of scattering by considering the simplest, scalar wave case of scattering by a spherical black hole. It then develops the formalism of spin-weighted spheroidal harmonics and of plane wave representations for neutrino, electromagnetic and gravitational scattering. Research workers and graduate and advanced undergraduate students in scattering theory, wave propagation and relativity will find this a comprehensive treatment of the topic.
Shoot Apex and Leaf Growth
Authors: Williams
Published: July 2010

First published in 1975, this book is a comprehensive and quantitative study of the shoot apex and leaf growth. Its central purpose is to provide precise quantitative descriptions of shoot apical systems of very diverse types. Vegetative apices are considered except for wheat for which a description of the developing inflorescence is also given. The descriptions rely on a development of the old technique of serial reconstruction, which allows the early stages in growth of leaf primordia and related tissues to be measured as volume. An important feature of the book is the numerous three-dimensional scale drawings, which, together with the photomicrographs, enable the reader to build up a clear picture of the process of growth in the stem apex. The appendix contains details of the methods employed in this quantitative study together with the procedures used for data processing. This major study on the growth of higher plants will be a standard work and will be a valuable source of quantitative information. Botanists, particularly those studying plant physiology, crop science, developmental biology and theoretical biology, will find this stimulating book has much to say that is of permanent value.
Darwin's Plots
Authors: Beer Gillian
Published: July 2010

Gillian Beer's landmark book demonstrates how Darwin overturned fundamental cultural assumptions in his narratives, how George Eliot, Thomas Hardy and other writers pursued and resisted their contradictory implications, and how the stories he produced about natural selection and the struggle for life now underpin our culture. This second edition of Darwin's Plots incorporates a new preface by the author and a foreword by the distinguished American scholar George Levine.
Modelling food safety and economic consequences of surveillance and control strategies forSalmonellain pigs and pork
Authors: BAPTISTA F. M. , HALASA T. , ALBAN L. , NIELSEN L. R.
Published: July 2010

Targets for maximum acceptable levels ofSalmonellain pigs and pork are to be decided. A stochastic simulation model accounting for herd and abattoir information was used to evaluate food safety and economic consequences of different surveillance and control strategies, based among others on Danish surveillance data. An epidemiological module simulated theSalmonellacarcass prevalence for different scenarios. Cost-effectiveness analysis was used to compare the costs of the different scenarios with their expected effectiveness. Herd interventions were not found sufficient to attainSalmonellacarcass prevalence <1%. The cost-effectiveness of abattoir interventions changed with abattoir size. The most cost-effective strategy included the use of steam vacuum and steam ultrasound. Given uncertainty of the effect of steam vacuum and steam ultrasound, model results should be updated as more information becomes available. This framework contributes to informed decision-making for a more cost-effective surveillance and control ofSalmonellain pigs and pork.
IMAGE and DMSP observations of a density trough inside the plasmasphere
Authors: Fu H. S. , Tu J. , Cao J. B. , Song P. , Reinisch B. W. , Gallagher D. L. , Yang B.
Published: July 2010

We report coordinated observations of a density trough within the plasmasphere using the measurements from the radio plasma imager (RPI) and extreme ultraviolet imager (EUV) on the IMAGE satellite and the measurements from DMSP F‐15. The density trough inside the plasmasphere with a width of ∼0.7 RE in terms of L shell (from L ∼ 2.3 to L ∼ 3.0) was observed in situ by RPI when IMAGE traversed the plasmasphere in ∼2130 magnetic local time (MLT) sector. The plasmasphere images taken by the IMAGE EUV instrument confirm that the density trough is inside the plasmasphere. A 2‐D electron density image constructed from the RPI active sounding measurements reveals that the density trough extends along the magnetic field from the IMAGE orbit to at least 41° magnetic latitude. Meanwhile, the DMSP‐F15 satellite, circling the Earth at about 850 km altitude, detected a light ion density trough at the same time on the same L shells and similar MLT sector. The coordinated observations with the IMAGE and DMSP‐F15 satellite demonstrate, for the first time, that the density trough is a low‐density plasmaspheric structure extending from the plasmasphere to the topside ionosphere along the geomagnetic field lines.
Substorm triggering by new plasma intrusion: Incoherent‐scatter radar observations
Authors: Lyons L. R. , Nishimura Y. , Shi Y. , Zou S. , Kim H.‐J. , Angelopoulos V. , Heinselman C. , Nicolls M. J. , Fornacon K.‐H.
Published: July 2010

In the companion paper, we identified a repeatable sequence of events leading to substorm onset in THEMIS all‐sky imager observations: enhanced flows bring new plasma into the plasma sheet. The new plasma then moves earthward as a flow channel, bringing it to the near‐Earth plasma sheet and where it produces onset instability. New plasma entering the dusk (dawn) convection cell drifts equatorward and eastward and then around the Harang reversal, leading to pre‐midnight (near‐ and post‐midnight) onset. Here we present evidence supporting this sequence using incoherent scatter radar (ISR) ionospheric observations. Using the Sondrestrom ISR, we find that enhanced flows of new plasma commonly enter the plasma sheet from the polar cap ∼8 min prior to onset. These flows are related to poleward boundary intensification signatures, consistent with the inferences from the imagers. Using the Poker Flat ISR (PFISR), we find that shortly before onset, enhanced westward flows reach the subauroral polarization streams (SAPS) region equatorward of the Harang reversal (dusk‐cell onsets) or enhanced eastward flows enter the onset region from the poleward direction (dawn‐cell onset). PFISR proton precipitation signatures are consistent with the possibility that the enhanced flows consist of reduced‐entropy plasma sheet plasma, and that onset occurs poleward of much of the enhanced SAPS flow (dusk‐cell onsets) or equatorward of the enhanced eastward flows (dawn‐cell onsets). Consistency with reduced entropy plasma is seen only within the enhanced flows, leading us to suggest that intrusion of low‐entropy plasma may alter the radial gradient of entropy toward onset instability.
Do magnetospheric shear Alfvén waves generate sufficient electron energy flux to power the aurora?
Authors: Watt C. E. J. , Rankin R.
Published: July 2010

Using a self‐consistent drift‐kinetic simulation code, we investigate whether electron acceleration owing to shear Alfvén waves in the plasma sheet boundary layer is sufficient to cause auroral brightening in the ionosphere. The free parameters used in the simulation code are guided by in situ observations of wave and plasma parameters in the magnetosphere at distances >4 RE from the Earth. For the perpendicular wavelength used in the study, which maps to ∼4 km at 110 km altitude, there is a clear amplitude threshold which determines whether magnetospheric shear Alfvén waves above the classical auroral acceleration region can excite sufficient electrons to create the aurora. Previous studies reported wave amplitudes that easily exceed this threshold; hence, the results reported in this paper demonstrate that auroral acceleration owing to shear Alfvén waves can occur in the magnetosphere at distances >4 RE from the Earth.
Stationary, oscillating or drifting mantle‐driven geomagnetic flux patches?
Authors: Amit Hagay , Aubert Julien , Hulot Gauthier
Published: July 2010

The impact of the heterogeneous lower mantle on the geomagnetic field is under debate, especially the question of whether high‐latitude intense geomagnetic flux patches currently observed at the core surface are stationary, oscillating, or drifting on longer time scales. While the correlation between the location of these patches with that of similar patches found in the time‐averaged paleomagnetic field may suggest stationary behavior, their variability over archaeomagnetic time scales together with their weaker signature in the average paleomagnetic field relative to the present geomagnetic field precludes such a scenario. Here we use numerical dynamos with an imposed heat flux boundary condition based on lower mantle tomography to study the behavior of such intense magnetic flux patches. We design an algorithm to detect centers of intense flux patches and track their time evolution. We find that the time‐dependent nature of those patches comprises oscillatory motion about statistically preferred locations imposed by mantle control, with episodic drift from one preferred location to the other corresponding to an azimuthal migration of fluid downwelling structures that concentrate surface magnetic flux. This statistical behavior provides a possible explanation for both the observed variability of high‐latitude patches on the archaeomagnetic time scale and the similar locations of the current patches and the weaker patches seen in the paleomagnetic field. Our simulations also show that the patches exhibit more time dependence and less coherency in the southern hemisphere, leading to a weaker time‐averaged patch signature in that hemisphere.
The 2002 M5 Au Sable Forks, NY, earthquake sequence: Source scaling relationships and energy budget
Authors: Viegas Gisela , Abercrombie Rachel E. , Kim Won‐Young
Published: July 2010

We find invariant high stress drops and radiated energies for a sequence of intraplate earthquakes. We estimate source parameters of the Au Sable Forks, NY, earthquake (M5, 2002) and aftershocks. This intraplate earthquake was the largest to occur in Eastern North America since 1988 and the largest to be recorded by regional broadband networks. We use the empirical Green's function (EGF) method and define a set of qualitative and quantitative rules for the selection of EGF earthquake pairs and for the quality verification of the obtained EGF spectral ratio. We use a multitaper code that performs the complex spectral division with minimum frequency leakage and allows transformation back to the time domain to check the validity of the EGF event. We estimate source parameters for 22 earthquakes (M1–M5) in the sequence. The median stress drop of 104 MPa (using Madariaga source model, and 19 MPa for a Brune model) is significantly larger than estimates for interplate earthquakes. The lower crustal strain rates, and longer fault healing times in intraplate environments, may be responsible for this high average value. We find constant stress drop between M2 and M5, up to the bandwidth resolution limit (80 Hz) of the study, and no evidence of stress drop breakdown for M2 to M1 earthquakes. We find consistently high radiated seismic energy and apparent stress, and a median radiated energy to seismic moment ratio of 9 × 10−5. This is significantly larger than estimates for interplate earthquakes (∼2 × 10−5) and consistent with higher stress drops and stronger faults.