bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatty acid composition of muscle and adipose tissues of organic and conventional Blanca Andaluza suckling kids
Authors: De la Vega F. , Guzmán J. L. , Delgado-Pertíñez M. , Zarazaga L. A. , Argüello A.
Published: July 2013

Interest in the preservation of autochthonous breeds such as the Blanca Andaluza goat (meat breed), raised under grazing-based management, has recently increased among Spanish farmers. A study of the possibilities of transformation to organic production needs to analyze the quality of their products. The aim of this study was to evaluate the fatty acid (FA) composition of muscle and adipose tissues of Blanca Andaluza goat kids under organic and conventional grazing–based management system. Twenty-four twin kids (12 males, 12 females) were selected from each system. The FA profile was determined in the longissimus thoracis muscle, kidney and pelvic fat. The percentages of C17:0, C17:1, C20:1, C20:4 n-6, C22:2 and several n-3 FAs were higher in organic meat; C12:0, C18:1 trans-11, CLA and C20:5 n-3 were lower in organic meat. The fat depots from the conventional kids showed lower percentages of C12:0, C14:0, C15:0, C17:0, C17:1, C18:3 n-3 and atherogenicity index, and higher percentage of C18:0. In the pelvic fat, the conventional kids displayed lower percentages of C16:0, C18:2 n-6 cis, PUFA, n-3 and n-6 FAs, and greater percentages of C18:1 n-9 cis and MUFA. The conventional kids displayed a major n6:n3 ratio in the kidney fat. No gender differences were observed. Significant differences were found only in some FA percentages of muscle and adipose tissues of suckling kids raised in organic and conventional livestock production systems, and due to this reason conventional grazing–based management farms could easily be transformed into organic production.
Short communication. Impact of the amino acid proline on the cold hardiness of honey bee, Apis mellifera L.
Authors: Mollaei M. , Hoseini S. A. , Karimi M. , Hekmat Z.
Published: July 2013

Like many insects, honey bee can increase its cold tolerance through freeze avoidance, using antifreeze proteins (AFPs) to lower its supercooling point (SCP). Proline is the most dominant amino acid in honey bee hemolymph, which can be obtained by the insect through feeding. In the current study the antifreeze activity of this amino acid was evaluated on worker honey bees, immediately before the start of cold season. The experiment was established on four treatments including three different concentrations of proline (1%, 3% and 4.35%) diluted in 1:1 water sucrose syrup, and the syrup without proline (control). Newly emerged worker honey bees were fed on the mentioned diets for 2 weeks, under cage condition, and then 20 bees from each treatment (cage) were selected randomly for determination of cold hardiness inside a cooling bath. Using a CHY data logger, equipped with a K100 sensor attached to the bee’s gaster, the SCP, the amount of released heat and the rate of this release as measures of insect cold hardiness were recorded. Proline significantly reduced honey bees’ SCP. The lowest point, -7.67±0.2646°C, was observed in the concentration of 1% proline. The amount of released heat and the rate of this release were not significantly different across the treatments.
Short communication. Mitochondrial DNA diversity of the founder populations of the Asturcón pony
Authors: Alvarez I. , Fernandez I. , Cuervo M. , Martin D. , Lorenzo L. , Goyache F.
Published: July 2013

A 380 bp fragment of the horse D-loop region was analysed in 42 founder mare samples of the bay-coated Asturcón pony obtained in three different and reproductively isolated mountainous areas of Western Asturias: range of “La Bobia” (20), range of “Carondio” (13) and range of “El Aguión” (9). These sequences were compared with the information provided by 37 founder matrilines of black-coated Asturcón assigned to the range of “Sueve” (26) and the “out-of-Sueve” (11) founder populations. The aim of this research was to ascertain the differences in founder mtDNA diversity between the two strains of the Asturcón pony and if such differences have geographical consistency. The 79 sequences analysed gave 16 different haplotypes defined by 33 polymorphic sites. The two Asturcón strains shared eight haplotypes that gathered 76% and 81% of the samples available in bay-coated and black-coated Asturcón, respectively. Both haplotypic (0.027 ± 0.006) and nucleotide (0.021 ± 0.011) diversity were higher in the bay-coated than in the black-coated Asturcón (0.024 ± 0.005 and 0.016 ± 0.009, respectively). AMOVA analyses failed in assessing any statistically differentiation among Asturcón geographical populations or strains. Most genetic variability is due to the individuals (estimates varying from 96.34% to 99.81%). Differentiation among strains or population took low and non-significant values. Differentiation between Asturcón pony strains using mtDNA marker would not have clear support. The two strains of the Asturcón pony breed likely derive from the same ancestral mare population.
Solubility Limit of Sol–Gel Grown Nano Zn1-xMgxO Through Charge Density Distribution
Authors: Francis Santhanam , Saravanan Ramachandran , Açıkgöz Mohammed
Published: July 2013

The mixed oxides Zn1-xMgxO were prepared as polycrystalline powders with various compositions (x = 0:02, 0.04, 0.05, and 0.10) using sol-gel technique. X-ray diffractometer (XRD) was used to characterize the powders for structural and electronic properties. X-ray diffraction analysis reveals that all the prepared samples exhibit the single wurtzite phase of zinc oxide (ZnO), and magnesiumdoping does not induce any secondary phase in the samples. The Bragg peak positions in the XRD patterns are found to be shifted towards higher 2q values with more addition of magnesium in the zinc oxide lattice. Magnesium addition in the zinc oxide lattice is found to enhance the mid bond electron density distribution up to x = 0:05 and then decrease for x = 0:10. Evidence of host lattice as well as interstitial addition of Mg2+ ions has been realized for x = 0:10, through electron density analysis.
A Robust Secondary Secure Communication Scheme Based on Synchronization of Spatiotemporal Chaotic Systems
Authors: Wang Xing-Yuan , Zhang Hao
Published: July 2013

This paper deals with the synchronization of spatiotemporal chaotic systems and presents a new robust secondary chaotic secure communication system for digital signal transmissions which can recover digital signal even though the transmitted signal is influenced by limited noise. The transmitter terminal and the receiver terminal both contain a spatiotemporal chaotic system and a hyperchaotic system. The asymptotic convergence of the errors between the states of the transmitter terminal and the receiver terminal has been proved based on the Lyapunov stable theory and active-passive decomposition (APD) method. Moreover, a random digital signal and a binary Lena image are encrypted and decrypted successfully to verify the efficiency of the proposed robust secure communication system.
Design and semisynthesis of photoactivable split‐GFP by incorporation of photocleavable functionality
Authors: Sakamoto Seiji , Terauchi Mika , Araki Yasuyuki , Wada Takehiko
Published: July 2013

The design of proteins whose structure and function can be manipulated by the external stimuli has been of great interest in the field of protein engineering. In particular, caged proteins which can be activated by photo‐irradiation become powerful tools for investigating a variety of biological events. Although protein caging is straightforward to render light‐responsive protein functions, this approach mostly have difficulties based on the preparation of caged proteins in which amino acid residues required for biological activities must be specifically modified with synthetic photolabile groups. The synthetic peptide‐based strategy for photoactivation of protein function may expand the versatility of protein caging approaches since the photolabile protecting group can be easily introduced into the peptide by means of standard solid‐phase methods in a site‐specific manner. In this study, we designed a new photoactivable green fluorescent protein (GFP), in which a relatively short C‐terminal fragment (residues 214–230) of a dissected protein was modified with 7‐diethylamino‐4‐hydroxymethylcoumarin (DECM) as a photoresponsive‐protecting group. The introduced DECM unit completely inhibited the reconstitution with the GFP N‐terminal fragment (residues 2–214). However, irradiation of visible light (>400 nm) resulted in efficient cleavage of DECM group, leading to acceleration of protein reassembly and concomitant GFP fluorescence recovery. These results demonstrated direct control of protein structure and function by application of the synthetic photocleavable functionality to a fragmented protein. The combined system of fragmented proteins and synthetic photocleavable elements will provide the useful and potentially wide applicable strategy for the regulation of protein structure and function by the light in a temporal and spacial manner. © 2013 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 100: 773–779, 2013.
Development of a Metal‐Ion‐Mediated Base Pair for Electron Transfer in DNA
Authors: Ehrenschwender Thomas , Schmucker Wolfgang , Wellner Christian , Augenstein Timo , Carl Patrick , Harmer Jeffrey , Breher Frank , Wagenknecht Hans‐Achim
Published: July 2013

A new C‐nucleoside structurally based on the hydroxyquinoline ligand was synthesized that is able to form stable pairs in DNA in both the absence and the presence of metal ions. The interactions between the metal centers in adjacent CuII‐mediated base pairs in DNA were probed by electron paramagnetic resonance (EPR) spectroscopy. The metal–metal distance falls into the range of previously reported values. Fluorescence studies with a donor–DNA–acceptor system indicate that photoinduced charge‐transfer processes across these metal‐ion‐mediated base pairs in DNA occur more efficiently than over natural base pairs.
Physical Properties of Superbulky Lanthanide Metallocenes: Synthesis and Extraordinary Luminescence of [EuII(CpBIG)2] (CpBIG=(4‐nBu‐C6H4)5‐Cyclopentadienyl)
Authors: Harder Sjoerd , Naglav Dominik , Ruspic Christian , Wickleder Claudia , Adlung Matthias , Hermes Wilfried , Eul Matthias , Pöttgen Rainer , Rego Daniel B. , Poineau Frederic , Czerwinski Kenneth R. , Herber Rolfe H. , Nowik Israel
Published: July 2013

The superbulky deca‐aryleuropocene [Eu(CpBIG)2], CpBIG=(4‐nBu‐C6H4)5‐cyclopentadienyl, was prepared by reaction of [Eu(dmat)2(thf)2], DMAT=2‐Me2N‐α‐Me3Si‐benzyl, with two equivalents of CpBIGH. Recrystallizyation from cold hexane gave the product with a surprisingly bright and efficient orange emission (45 % quantum yield). The crystal structure is isomorphic to those of [M(CpBIG)2] (M=Sm, Yb, Ca, Ba) and shows the typical distortions that arise from CpBIG⋅⋅⋅CpBIG attraction as well as excessively large displacement parameter for the heavy Eu atom (Ueq=0.075). In order to gain information on the true oxidation state of the central metal in superbulky metallocenes [M(CpBIG)2] (M=Sm, Eu, Yb), several physical analyses have been applied. Temperature‐dependent magnetic susceptibility data of [Yb(CpBIG)2] show diamagnetism, indicating stable divalent ytterbium. Temperature‐dependent 151Eu Mössbauer effect spectroscopic examination of [Eu(CpBIG)2] was examined over the temperature range 93–215 K and the hyperfine and dynamical properties of the EuII species are discussed in detail. The mean square amplitude of vibration of the Eu atom as a function of temperature was determined and compared to the value extracted from the single‐crystal X‐ray data at 203 K. The large difference in these two values was ascribed to the presence of static disorder and/or the presence of low‐frequency torsional and librational modes in [Eu(CpBIG)2]. X‐ray absorbance near edge spectroscopy (XANES) showed that all three [Ln(CpBIG)2] (Ln=Sm, Eu, Yb) compounds are divalent. The XANES white‐line spectra are at 8.3, 7.3, and 7.8 eV, for Sm, Eu, and Yb, respectively, lower than the Ln2O3 standards. No XANES temperature dependence was found from room temperature to 100 K. XANES also showed that the [Ln(CpBIG)2] complexes had less trivalent impurity than a [EuI2(thf)x] standard. The complex [Eu(CpBIG)2] shows already at room temperature strong orange photoluminescence (quantum yield: 45 %): excitation at 412 nm (24270 cm−1) gives a symmetrical single band in the emission spectrum at 606 nm (νmax=16495 cm−1, FWHM: 2090 cm−1, Stokes‐shift: 2140 cm−1), which is assigned to a 4f65d1→4f7 transition of EuII. These remarkable values compare well to those for EuII‐doped ionic host lattices and are likely caused by the rigidity of the [Eu(CpBIG)2] complex. Sharp emission signals, typical for EuIII, are not visible.
Synthesis of 4‐(2‐Phenylhydrazono)‐1‐(4‐phenylthiazol‐2‐yl)‐1H‐pyrazol‐5(4H)‐one Compounds and Characterization of Their Affinities to Anti‐apoptotic Bcl‐2 Family Proteins
Authors: Shi Shicheng , Han Li , Zhou Mi , Li Yangfeng , Liu Zhen , Yu Biao , Wang Renxiao
Published: July 2013

Organic compounds containing the thiazol‐2‐yl‐1H‐pyrazol‐5(4H)‐one moiety are known to be associated with versatile pharmacological applications. In this study, we describe the methods for preparing 4‐(2‐phenylhydrazono)‐1‐(4‐phenylthiazol‐2‐yl)‐1H‐pyrazol‐5(4H)‐one compounds. A set of 26 compounds were synthesized with overall yields ranging between 37% –92%. They were tested in a fluorescence polarization‐based binding assay against three anti‐apoptotic Bcl‐2 family proteins, including Bcl‐xL, Bcl‐2, and Mcl‐1. Our results indicate that this class of compounds are not effective inhibitors of these anti‐apoptotic Bcl‐2 family proteins. Their apoptosis‐inducing effects are possibly due to BAX activation as suggested by Gavathiotis et al. in their recent study. However, other possibilities should not be ignored. In addition, a crystal structure obtained by us reveals that the exocyclic double bond in the molecular structure of this class of compounds is in the (Z)‐configuration
Photodegradation‐Induced Changes in the Characteristics of Dissolved Organic Matter with Different Sources and Their Effects on Disinfection By‐Product Formation Potential
Authors: Lee Mi‐Hee , Hur Jin
Published: July 2013

Changes in the apparent characteristics of dissolved organic matter (DOM) upon photodegradation and their influences on disinfection by‐products formation potentials (DBPFP) were examined using biodegraded DOM from six different sources (leaf litter, algae, compost, paddy water, treated sewage, and headwater). After seven day UV irradiation, no substantial changes occurred in the dissolved organic carbon (DOC) concentrations, but significant decreases were observed for the specific UV absorbance. In general, fulvic‐like and humic‐like fluorophores appear to be more affected by photodegradation than protein‐like fluorophores (or DOM components) and/or than the DOM structures associated with a shorter excitation wavelength. Size exclusion chromatograms revealed that UV absorbing molecules of intermediate size ranging from 1 to 5 kDa were most vulnerable to the UV irradiation. Except for leaf litter‐derived DOM, UV irradiation did not lead to substantial changes in specific DBPFP (i.e. disinfection by‐product (DBP)/dissolved organic carbon) comparable to those of the DOM characteristics, suggesting that many of the DBP precursors were not easily removed by photodegradation or some photochemically produced compounds could operate as DBP precursors. All the DOM samples exhibited greater formation potential for haloacetic acids per organic carbon than trihalomethanes irrespective of the sources. In general, correlations between DOM properties and specific DBPFP became stronger after photodegradation. The intermediate sized UV‐absorbing moieties appear to be actively involved in forming DBPs for photodegraded DOM. An integrated region of protein‐like fluorescence intensities may be suggested as an estimation index for specific DBPFP independent of the DOM sources.
Are survivors who report cancer‐related financial problems more likely to forgo or delay medical care?
Authors: Kent Erin E. , Forsythe Laura P. , Yabroff K. Robin , Weaver Kathryn E. , de Moor Janet S. , Rodriguez Juan L. , Rowland Julia H.
Published: July 2013

BACKGROUND

Financial problems caused by cancer and its treatment can substantially affect survivors and their families and create barriers to seeking health care.

METHODS

The authors identified cancer survivors diagnosed as adults (n = 1556) from the nationally representative 2010 National Health Interview Survey. Using multivariable logistic regression analyses, the authors report sociodemographic, clinical, and treatment‐related factors associated with perceived cancer‐related financial problems and the association between financial problems and forgoing or delaying health care because of cost. Adjusted percentages using the predictive marginals method are presented.

RESULTS

Cancer‐related financial problems were reported by 31.8% (95% confidence interval, 29.3%‐34.5%) of survivors. Factors found to be significantly associated with cancer‐related financial problems in survivors included younger age at diagnosis, minority race/ethnicity, history of chemotherapy or radiation treatment, recurrence or multiple cancers, and shorter time from diagnosis. After adjustment for covariates, respondents who reported financial problems were more likely to report delaying (18.3% vs 7.4%) or forgoing overall medical care (13.8% vs 5.0%), prescription medications (14.2% vs 7.6%), dental care (19.8% vs 8.3%), eyeglasses (13.9% vs 5.8%), and mental health care (3.9% vs 1.6%) than their counterparts without financial problems (all P < .05).

CONCLUSIONS

Cancer‐related financial problems are not only disproportionately represented in survivors who are younger, members of a minority group, and have a higher treatment burden, but may also contribute to survivors forgoing or delaying medical care after cancer. Cancer 2013;119:3710–3717. © 2013 American Cancer Society.
CTNNB1 45F mutation is a molecular prognosticator of increased postoperative primary desmoid tumor recurrence
Authors: Colombo Chiara , Miceli Rosalba , Lazar Alexander J. , Perrone Federica , Pollock Raphael E. , Le Cesne Axel , Hartgrink Henk H. , Cleton‐Jansen Anne‐Marie , Domont Julien , Bovée Judith V. M. G. , Bonvalot Sylvie , Lev Dina , Gronchi Alessandro
Published: July 2013

BACKGROUND

A role for the serine to phenylalanine substitution at codon 45 (the S45F mutation) in the catenin (cadherin‐associated protein) β‐1 (CTNNB1) gene as a molecular predictor of local recurrence in patients with primary, sporadic desmoid tumor (DT) has been reported. To confirm the previous data, the authors evaluated the correlation between CTNNB1 mutation type and local recurrence in this multi‐institutional, retrospective study.

METHODS

Patients with primary, sporadic DT who underwent macroscopic complete surgical resection were included. Recurrence‐free survival (RFS) analyses were conducted using the Kaplan‐Meier method and log‐rank tests to compare strata.

RESULTS

In total, 179 patients were identified, including 65% females and 35% males (median age, 39 years; median tumor size, 7 cm). Most DTs were located in the abdominal/chest wall (42%) followed by extra‐abdominal sites (40%) and intra‐abdominal sites (18%). All patients underwent either R0 resection (62%) or R1 resection (38%), and most underwent surgery alone (80%). The tyrosine to alanine substitution at codon 41 (T41A) was the most frequent mutation (45%), but the S45F mutation was more prevalent in extra‐abdominal DTs compared with other sites (P < .001). At a median follow‐up of 50 months, 86% of patients remained alive without disease. The estimated 3‐year and 5‐year RFS rates were 0.49 and 0.45, respectively, for patients who had tumors with the S45F mutation; 0.91 and 0.91, respectively, for patients who had wild‐type tumors; and 0.70 and 0.66, respectively, for all others (P < .001). A similar trend was observed for patients who underwent surgery alone (P < .001). On multivariable analysis, mutation remained the only factor that was prognostic for local recurrence.

CONCLUSIONS

This series confirmed that primary, completely resected, sporadic DTs with the S45F mutation have a greater tendency for local recurrence. With increasing implementation of “watchful‐waiting” for DT management, it will be important to determine whether mutation type predicts outcome for these patients. Cancer 2013;119:3692–3702. © 2013 American Cancer Society.
Coupled and reduced dimensional modeling of respiratory mechanics during spontaneous breathing
Authors: Ismail M. , Comerford A. , Wall W. A.
Published: July 2013

In this paper, we develop a total lung model based on a tree of 0D airway and acinar models for studying respiratory mechanics during spontaneous breathing. This model utilizes both computer tomography‐based geometries and artificially generated lobe‐filling airway trees to model the entire conducting region of the lung. Beyond the conducting airways, we develop an acinar model, which takes into account the alveolar tissue resistance, compliance, and the intrapleural pressure. With this methodology, we compare four different 0D models of airway mechanics and determine the best model based on a comparison with a 3D–0D coupled model of the conducting airways; this methodology is possible because the majority of airway resistance is confined to the lower generations, that is, the trachea and the first few bronchial generations. As an example application of the model, we simulate the flow and pressure dynamics under spontaneous breathing conditions, that is, at flow conditions driven purely by pleural space pressure. The results show good agreement, both qualitatively and quantitatively, with reported physiological values. One of the key advantages of this model is the ability to provide insight into lung ventilation in the peripheral regions. This is often crucial because this is where information, specifically for studying diseases and gas exchange, is needed. Thus, the model can be used as a tool for better understanding local peripheral lung mechanics without excluding the upper portions of the lung. This tool will be also useful for in vitro investigations of lung mechanics in both health and disease.Copyright © 2013 John Wiley & Sons, Ltd.
New Logarithmic Sobolev Inequalities and an ɛ‐Regularity Theorem for the Ricci Flow
Authors: Hein Hans‐Joachim , Naber Aaron
Published: July 2013

In this note, we prove an ɛ‐regularity theorem for the Ricci flow. Let (Mn,g(t)) with t ∊ [−T,0] be a Ricci flow, and let Hx0(y,s) be the conjugate heat kernel centered at some point (x0,0) in the final time slice. By substituting Hx0(−,s) into Perelman's W‐functional, we obtain a monotone quantity Wx0(s) that we refer to as the pointed entropy. This satisfies Wx0(s) ≤ 0, and Wx0(s) = 0 if and only if (Mn,g(t)) is isometric to the trivial flow on Rn. Then our main theorem asserts the following: There exists ɛ > 0, depending only on T and on lower scalar curvature and μ‐entropy bounds for the initial slice (Mn,g(−T)) such that Wx0(s) ≥ −ɛ implies |Rm| ≤ r−2 on Pɛ r(x0,0), where r2 ≡ |s| and Pρ(x,t) ≡ Bρ(x,t) × (t−ρ2,t] is our notation for parabolic balls.

The main technical challenge of the theorem is to prove an effective Lipschitz bound in x for the s‐average of Wx(s). To accomplish this, we require a new log‐Sobolev inequality. Perelman's work implies that the metric measure spaces (Mn,g(t),dvolg(t)) satisfy a log‐Sobolev; we show that this is also true for the heat kernel weighted spaces (Mn,g(t),Hx0(−,t)dvolg(t)). Our log‐Sobolev constants for these weighted spaces are in fact universal and sharp.

The weighted log‐Sobolev has other consequences as well, including certain average Gaussian upper bounds on the conjugate heat kernel. © 2014 Wiley Periodicals, Inc.
Ecosystems perspective on financial networks: Diagnostic tools
Authors: Viegas Eduardo , Takayasu Misako , Miura Wataru , Tamura Koutarou , Ohnishi Takaaki , Takayasu Hideki , Jensen Henrik Jeldtoft
Published: July 2013

The world economy consists of highly interconnected and interdependent commercial and financial networks. Here, we develop temporal and structural network tools to analyze the state of the economy and the financial markets. Our analysis indicates that a strong clustering can be a warning sign. Reduction in diversity, which was an essential aspect of the dynamics surrounding the financial markets crisis of 2008, is seen as a key emergent feature arising naturally from the evolutionary and adaptive dynamics inherent to the financial markets. Similarly, collusion amongst construction firms in a number of regions in Japan in the 2000s can be identified with the formation of clusters of anomalous highly connected companies. © 2013 Wiley Periodicals, Inc. Complexity 19: 22–36, 2013
Solid–Solid Heterogeneous Catalysis: The Role of Potassium in Promoting the Dehydrogenation of the Mg(NH2)2/2 LiH Composite
Authors: Wang Jianhui , Chen Ping , Pan Hongge , Xiong Zhitao , Gao Mingxia , Wu Guotao , Liang Chu , Li Cao , Li Bo , Wang Jieru
Published: July 2013

Considerable efforts have been devoted to the catalytic modification of hydrogen storage materials. The K‐modified Mg(NH2)2/2 LiH composite is a typical model for such studies. In this work, we analyze the origin of the kinetic barrier in the first step of the dehydrogenation and investigate how K catalyzes this heterogeneous solid‐state reaction. Our results indicate that the interface reaction of Mg(NH2)2 and LiH is the main source of the kinetic barrier at the early stage of the dehydrogenation for the intensively ball‐milled Mg(NH2)2/2 LiH sample. K can effectively activate Mg(NH2)2 as well as promote LiH to participate in the dehydrogenation. Three K species of KH, K2Mg(NH2)4, and Li3K(NH2)4 likely transform circularly in the dehydrogenation (KH↔K2Mg(NH2)4↔KLi3(NH2)4), which creates a more energy‐favorable pathway and thus leads to the overall kinetic enhancement. This catalytic role of K in the amide/hydride system is different from the conventional catalysis of transition metals in the alanate system.
Synthesis of 1,2‐Diaryl‐ and 1‐Aryl‐2‐alkylimidazoles with Sterically Demanding Substituents
Authors: Micksch Maik , Tenne Mario , Strassner Thomas
Published: July 2013

1,2‐Diarylimidazoles are an important class of compounds. They are frequently used as ligands for photophysically active metal complexes and also display physiological activity. We developed a new, high‐yielding procedure for the synthesis of 1,2‐diaryl‐substituted imidazoles with sterically demanding substituents at the respective ortho positions by starting from commercially available anilines and benzoic acids through the corresponding acid chlorides. The metal‐free method provides access to a variety of different substituents on the phenyl rings at N‐1 and C‐2 as well as at the 4,5‐positions of the imidazole backbone. Our new method is also suitable for the preparation of 1‐aryl‐2‐alkylimidazoles.
Analysis of Redox Activity of Proteins on the Carbon Screen Printed Electrodes
Authors: Suprun Elena V. , Zharkova Maria S. , Morozevich Galina E. , Veselovsky Alexander V. , Shumyantseva Victoria V. , Archakov Alexander I.
Published: July 2013

Direct redox activity of different proteins was investigated on the surface of carbon screen printed electrodes (SPE). The signal attributed to the electrochemical oxidation of amino acid residues (cysteine (Cys), tryptophan (Trp) and tyrosine (Tyr)) was registered at Emax from 0.6 to 0.7 V (vs. Ag/AgCl). Based on the difference in the redox behavior of L‐tyrosine and 3‐nitro‐L‐tyrosine, the selective electrochemical detection of native and nitrated albumins was demonstrated. It was shown that the electrochemical signal correlated with the surface density of electroactive amino acid residues on the protein molecule. A simple electrochemical method for the total protein analysis was proposed.
Empirical Hierarchical Bayes Approach to Gene‐Environment Interactions: Development and Application to Genome‐Wide Association Studies of Lung Cancer in TRICL
Authors: Sohns Melanie , Viktorova Elena , Amos Christopher I. , Brennan Paul , Fehringer Gord , Gaborieau Valerie , Han Younghun , Heinrich Joachim , Chang‐Claude Jenny , Hung Rayjean J. , Müller‐Nurasyid Martina , Risch Angela , Lewinger Juan Pablo , Thomas Duncan C. , Bickeböller Heike
Published: July 2013

The analysis of gene‐environment (G × E) interactions remains one of the greatest challenges in the postgenome‐wide association studies (GWASs) era. Recent methods constitute a compromise between the robust but underpowered case‐control and powerful case‐only methods. Inferences of the latter are biased when the assumption of gene‐environment (G‐E) independence in controls fails. We propose a novel empirical hierarchical Bayes approach to G × E interaction (EHB‐GE), which benefits from greater rank power while accounting for population‐based G‐E correlation. Building on Lewinger et al.'s ([2007] Genet Epidemiol 31:871–882) hierarchical Bayes prioritization approach, the method first obtains posterior G‐E correlation estimates in controls for each marker, borrowing strength from G‐E information across the genome. These posterior estimates are then subtracted from the corresponding case‐only G × E estimates. We compared EHB‐GE with rival methods using simulation. EHB‐GE has similar or greater rank power to detect G × E interactions in the presence of large numbers of G‐E correlations with weak to strong effects or only a low number of such correlations with large effect. When there are no or only a few weak G‐E correlations, Murcray et al.'s method ([2009] Am J Epidemiol 169:219–226) identifies markers with low G × E interaction effects better. We applied EHB‐GE and competing methods to four lung cancer case‐control GWAS from the Interdisciplinary Research in Cancer of the Lung/International Lung Cancer Consortium with smoking as environmental factor. A number of genes worth investigating were identified by the EHB‐GE approach.
Ridge Regression in Prediction Problems: Automatic Choice of the Ridge Parameter
Authors: Cule Erika , De Iorio Maria
Published: July 2013

To date, numerous genetic variants have been identified as associated with diverse phenotypic traits. However, identified associations generally explain only a small proportion of trait heritability and the predictive power of models incorporating only known‐associated variants has been small. Multiple regression is a popular framework in which to consider the joint effect of many genetic variants simultaneously. Ordinary multiple regression is seldom appropriate in the context of genetic data, due to the high dimensionality of the data and the correlation structure among the predictors. There has been a resurgence of interest in the use of penalised regression techniques to circumvent these difficulties. In this paper, we focus on ridge regression, a penalised regression approach that has been shown to offer good performance in multivariate prediction problems. One challenge in the application of ridge regression is the choice of the ridge parameter that controls the amount of shrinkage of the regression coefficients. We present a method to determine the ridge parameter based on the data, with the aim of good performance in high‐dimensional prediction problems. We establish a theoretical justification for our approach, and demonstrate its performance on simulated genetic data and on a real data example. Fitting a ridge regression model to hundreds of thousands to millions of genetic variants simultaneously presents computational challenges. We have developed an R package, ridge, which addresses these issues. Ridge implements the automatic choice of ridge parameter presented in this paper, and is freely available from CRAN.
New stratospheric dust belt due to the Chelyabinsk bolide
Authors: Gorkavyi Nick , Rault D. F. , Newman P. A. , da Silva A. M. , Dudorov A. E.
Published: July 2013

The Ozone Mapping Profiler Suite (OMPS) Limb Profiler (LP) on the recently launched NASA/NOAA NPP/Suomi satellite detected aerosol excess in the mid‐stratosphere (25–45 km altitude) between 50°N and 70°N latitudes. OMPS/LP observations trace this aerosol plume to the meteor that struck near Chelyabinsk, Russia on 15 February 2013. This new dust layer, located above the Junge aerosol layer, has persisted over at least a 3 month period. Material collected on the ground following the bolide explosion showed that the meteor was mostly composed of olivine and pyroxenes. Simulations using Lagrangian and Eulerian atmospheric models trace the plume back to Chelyabinsk and confirm that the plume altitude was at altitudes between 25 and 45 km. The models also confirm the plume circumpolar longitudinal spreading observed by OMPS/LP, with propagation speeds up to 85 m/s.
Simulating soil freeze/thaw dynamics with an improved pan‐Arctic water balance model
Authors: Rawlins M. A. , Nicolsky D. J. , McDonald K. C. , Romanovsky V. E.
Published: July 2013

The terrestrial Arctic water cycle is strongly influenced by the presence of permafrost, which is at present degrading as a result of warming. In this study, we describe improvements to the representation of processes in the pan‐Arctic Water Balance Model (PWBM) and evaluate simulated soil temperature at four sites in Alaska and active‐layer thickness (ALT) across the pan‐Arctic drainage basin. Model improvements include new parameterizations for thermal and hydraulic properties of organic soils; an updated snow model, which accounts for seasonal changes in density and thermal conductivity; and a new soil freezing and thawing model, which simulates heat conduction with phase change. When compared against observations across Alaska within differing landscape vegetation conditions in close proximity to one another, PWBM simulations show no systematic soil temperature bias. Simulated temperatures agree well with observations in summer. In winter, results are mixed, with both positive and negative biases noted at times. In two pan‐Arctic simulations forced with atmospheric reanalysis, the model captures the mean in observed ALT, although predictability as measured by correlation is limited. The geographic pattern in northern hemisphere permafrost area is well estimated. Simulated permafrost area differs from observed extent by 7 and 17% for the two model runs. Results of two simulations for the periods 1996–1999 and 2066–2069 for a single grid cell in central Alaska illustrate the potential for a drying of soils in the presence of increases in ALT, annual total precipitation, and winter snowfall.
Microstructure, mechanical property, biodegradation behavior, and biocompatibility of biodegradable Fe–Fe2O3 composites
Authors: Cheng J. , Huang T. , Zheng Y. F.
Published: July 2013

In this study, the effects of Fe2O3 (addition, 2, 5, 10, and 50 wt %) on the microstructure, mechanical properties, corrosion behaviors, and in vitro biocompatibility of Fe–Fe2O3 composites fabricated by spark plasma sintering were systematically investigated as a novel‐structure biodegradable metallic material. The results of X‐ray diffraction analysis and optical microscopy indicated that Fe–Fe2O3 composite is composed of α‐Fe and FeO instead of Fe2O3. Both eletrochemical measurements and immersion test showed a faster degradation rate of Fe–2Fe2O3 and Fe–5Fe2O3 composites than pure iron and Fe–5Fe2O3 exhibited the fastest corrosion rate among these composites. Besides, the effect of Fe2O3 on the corrosion behavior of Fe–Fe2O3 composites was discussed. The extracts of Fe–Fe2O3 composite exhibited no cytotoxicity to both ECV304 and L929 cells, whereas greatly reduced cell viabilities of vascular smooth muscle cells. In addition, good hemocompatibility of all Fe–Fe2O3 composites and pure iron was obtained. To sum up, Fe–5Fe2O3 composite is a promising alternative for biodegradable stent material with elevated corrosion rate, enhanced mechanical properties, as well as excellent biocompatibility. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2277–2287, 2014.
Increased porosity of electrospun hybrid scaffolds improved bladder tissue regeneration
Authors: Horst Maya , Milleret Vincent , Nötzli Sarah , Madduri Srinivas , Sulser Tullio , Gobet Rita , Eberli Daniel
Published: July 2013

The object of this study was to investigate the role of scaffold porosity on tissue ingrowth using hybrid scaffolds consisting of bladder acellular matrix and electrospun poly (lactide‐co‐glycolide) (PLGA) microfibers that mimic the morphological characteristics of the bladder wallin vitroandin vivo. We compared single‐spun (SS) PLGA scaffolds with more porous cospun (CS) scaffolds (PLGA and polyethylene glycol). Scaffolds were characterized by scanning electron microscopy. Bladder smooth muscle cells (SMCs) were seeded, and proliferation and histological assays were performed. Sixteen rats were subjected to augmentation cystoplasty with seeded SS or CS scaffolds, morphological, and histological studies were performed 2 and 4 weeks after implantation. The porosities of SS and CS scaffolds were 73.1 ± 2.9% and 80.9 ± 1.5%, respectively. Thein vitroevaluation revealed significantly deeper cell migration into CS scaffolds. Thein vivoevaluation showed significant shrinkage of SS scaffolds (p = 0.019). The histological analysis revealed a bladder wall‐like structure with urothelial lining and SMC infiltration in both groups. The microvessel density was significantly increased in the CS scaffolds (p <0.001). Increasing the porosity of electrospun hybrid scaffolds is an effective strategy to enhance cell proliferation and distributionin vitroand tissue ingrowthin vivo. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2116–2124, 2014.
New sol‐gel bioactive glass and titania composites with enhanced physico‐chemical and biological properties
Authors: Pawlik Justyna , Widziołek Magdalena , Cholewa‐Kowalska Katarzyna , Łączka Maria , Osyczka Anna Maria
Published: July 2013

We developed TiO2 matrix composites modified by sol‐gel bioactive glasses (SBG) of either high CaO content (A2) or high SiO2 content (S2). The latter were mixed with titanium dioxide (TiO2) at 75:25, 50:50, and 25:75 weight ratios and sintered at 1250°C for 2 h. We examined the effects of various types (A2 or S2) and compositional TiO2:SBG ratios on the mechanical properties of resulting composites, their bioactivity and human bone marrow mesenchymal stem cells (MSC) response. The chemistry of SBGs influenced the phase composition, mechanical and biological properties of the composites. Rutile and titanite prevailed in A2‐TiO2 composites, and rutile and crystobalite in S2‐TiO2 composites. Compressive strength increased significantly for 25A2‐TiO2 composites (140 MPa) compared to matrix TiO2 (58 MPa). Composites containing 50–75 wt % of either SBG displayed bioactive properties as determined by simulated body fluid test. Compared to TiO2, human bone marrow stromal cell (BMSC) viability was enhanced on the composites containing 25 wt % of either SBG, whereas the composites modified by 25 wt % of S2 enhanced alkaline phosphatase activity and mineralization in cultures treated with osteogenic inducers–dexamethasone (Dex) or bone morphogenetic protein. Increasing amounts of A2 in TiO2 matrix decreased cell viability but increased collagen deposition and mineralized matrix production by BMSC. Considering the physico‐chemical and biological properties of the presented composites, the modification of TiO2 with SBG may prove useful strategy in several bone tissue related regeneration strategies. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2383–2394, 2014.
Intermittent heterochronic plasma exchange as a modality for delaying cellular senescence—A hypothesis
Authors: Kiprov Dobri D.
Published: July 2013

The population of baby boomers (age 60–65) is rapidly increasing globally. The aging of the human body is associated with the decline of cellular function which leads to the development of a variety of diseases. The increased demand for health care for the aging population creates significant financial burden to any healthcare system. Developing strategies and health intervention methods to ameliorate this situation is paramount. Experiments utilizing heterochronic parabiosis in mice have demonstrated that replacing the aging cellular milieu with the plasma of a young experimental animal leads to reversal of cellular senescence. This article describes a hypothetical model of intermittent heterochronic plasma exchange in humans as a modality for heterochronic parabiosis in an attempt to delay cellular senescence. J. Clin. Apheresis, 28:387–389, 2013. © 2013 Wiley Periodicals, Inc.
The role of trustworthiness in recruitment and selection: A review and guide for future research
Authors: Klotz Anthony C. , da Motta Veiga Serge P. , Buckley M. Ronald , Gavin Mark B.
Published: July 2013

Although scholars recognize the importance of trustworthiness for both job applicants and hiring organizations, prior research exploring trustworthiness during the organizational pre‐entry period is scattered across a number of disparate literatures. This paper selectively reviews prior work that investigates the role of trustworthiness in the recruitment and selection processes. Within these pre‐entry processes, we explore how job applicants' and hiring organizations' perceptions of one another's trustworthiness, conceptualized as each parties' attitudes regarding the others' benevolence, integrity, and ability, influence meaningful recruitment and selection outcomes. Avenues for future research regarding trustworthiness are also identified in each section of the review. Finally, particular attention is given to two overarching issues at the intersection of trustworthiness and pre‐entry processes—trust violations and individual differences in propensity to trust. Copyright © 2013 John Wiley & Sons, Ltd.
Meal replacements, reduced energy density eating, and weight loss maintenance in primary care patients: A randomized controlled trial
Authors: Lowe Michael R. , Butryn Meghan L. , Thomas J. Graham , Coletta Maria
Published: July 2013

Objective

To compare the presence or absence of meal replacements (MRs) and an energy density (ED) intervention to facilitate weight loss maintenance.

Design and Methods

A total of 238 overweight primary care patients (mean body mass index = 39.5 kg/m2) began the study; 132 completed the 12‐week weight loss phase. Participants were randomly assigned to one of four maintenance conditions formed by crossing the presence or absence of MRs (MR+/MR−) and of the ED program (ED+/ED−) during a subsequent 9‐month maintenance phase. Follow‐up assessments occurred 1 and 2 years after treatment termination.

Results

Participants initially lost 6.1 kg. Analyses of variance based on weight change from the beginning of the maintenance phase to the 2‐year follow‐up produced a significant interaction. All groups except ED+/MR− regained substantial weight during follow‐up; the ED+/MR− group regained significantly less weight than the control group at both follow‐up assessments. No significant effects of treatment were found for several variables that were expected to mediate these outcomes.

Conclusions

Because weight losses achieved in lifestyle change programs for obesity are rarely maintained, the superior outcome achieved by the ED+/MR− condition is notable. Nonetheless, methodological issues and inability to identify a potential mediator of this outcome make replication of this finding essential.
Determination of the inheritance, cross‐resistance and detoxifying enzyme levels of a laboratory‐selected, spiromesifen‐resistant population of the predatory mite Neoseiulus californicus (Acari: Phytoseiidae)
Authors: Yorulmaz‐Salman Sibel , Ay Recep
Published: July 2013

BACKGROUND

Neoseiulus californicus of the family Phytoseiidae is an effective predatory mite species that is used to control pest mites.

RESULTS

The LC50 and LC60 values of spiromesifen were determined on N. californicus using a leaf‐disc method and spraying tower. A laboratory selection population designated SPR13 was found to have a 52.08‐fold resistance to spiromesifen following 13 selection cycles. This population developed low resistance to hexythiazox and moderate cross‐resistance to propargite, clofentezine, spirodiclofen, etoxazole and milbemectin. PBO, IBP and DEM synergised resistance 3.75‐, 2.54‐ and 1.93‐fold respectively. Crossing experiments revealed that spiromesifen resistance in the SPR13 population was intermediately dominant and monogenic. In addition, detoxifying enzyme activities were increased 2.74‐fold for esterase, 3.09‐fold for glutathione S‐transferase and 2.17‐fold for cytochrome P450 monooxygenase in the SPR13 population.

CONCLUSIONS

Selection for spiromesifen under laboratory conditions resulted in the development of spiromesifen resistance in the predatory mite N. californicus. Predatory mites that are resistant to pesticides are considered valuable for use in resistance management programmes within integrated pest control strategies. © 2013 Society of Chemical Industry
Interpreting observational studies: why empirical calibration is needed to correct p‐values
Authors: Schuemie Martijn J. , Ryan Patrick B. , DuMouchel William , Suchard Marc A. , Madigan David
Published: July 2013

Often the literature makes assertions of medical product effects on the basis of ‘ p < 0.05’. The underlying premise is that at this threshold, there is only a 5% probability that the observed effect would be seen by chance when in reality there is no effect. In observational studies, much more than in randomized trials, bias and confounding may undermine this premise. To test this premise, we selected three exemplar drug safety studies from literature, representing a case–control, a cohort, and a self‐controlled case series design. We attempted to replicate these studies as best we could for the drugs studied in the original articles. Next, we applied the same three designs to sets of negative controls: drugs that are not believed to cause the outcome of interest. We observed how often p < 0.05 when the null hypothesis is true, and we fitted distributions to the effect estimates. Using these distributions, we compute calibrated p‐values that reflect the probability of observing the effect estimate under the null hypothesis, taking both random and systematic error into account. An automated analysis of scientific literature was performed to evaluate the potential impact of such a calibration. Our experiment provides evidence that the majority of observational studies would declare statistical significance when no effect is present. Empirical calibration was found to reduce spurious results to the desired 5% level. Applying these adjustments to literature suggests that at least 54% of findings with p < 0.05 are not actually statistically significant and should be reevaluated. © 2013 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.