bluuebunny/crossref_metadata_2025 huggingface dataset:
Observations on aerophytic cyanobacteria and algae from ten caves in the Ojców National Park
Authors: Czerwik-Marcinkowska Joanna
Published: April 2013

This study, carried out in 2010–11, focuses on species composition and distribution of cyanobacterial and algal communities colonizing ten caves (Biała, Ciemna, Koziarnia, Krakowska, Łokietka, Okopy Wielka Dolna, Sąspowska, Sypialnia, Zbójecka and Złodziejska Caves) in the Ojców National Park (South Poland). A total of 85 taxa were identified, 35 of them belonging to cyanobacteria, 30 chlorophytes, and 20 belonging to other groups of algae. Aerophytic cyanobacteria dominated in these calcareous habitats. Nine species, Gloeocapsa alpina, Nostoc commune, Chlorella vulgaris, Dilabifilum arthopyreniae, Klebsormidium flaccidum, Muriella decolor, Neocystis subglobosa, and Orthoseira roseana, were the most abundant taxa in all the caves. The investigated microhabitats offer relatively stable microclimatic conditions and are likely to be responsible for the observed vertical distribution of aerophytic cyanobacteria and algae.
The activity of NADH-, NADPH- and Fd-dependent glutamate synthase in the plastids and cytosol of Pisum arvense L. root cells
Authors: Kubik-Dobosz Genowefa
Published: April 2013

Three forms of glutamate synthase (NADH-GOGAT, NADPH-GOGAT and Fd-(ferredoxin) GOGAT) were found in the plastids and cytosol of Pisum arvense root cells. The activities of the enzymes of both fractions decreased with increasing age of the plants, with the exception of plastid NADPH-GOGAT which exhibited markedly stable activity. NADH-GOGAT dominated in the cytosol of root cells of several day-old plants but after 14 days of cultivation, the activities of all of the GOGAT forms equalized. Plastid NADH-GOGAT and Fd-GOGAT showed similar activities in the root cells of 3-5 day-old plants, with Fd-GOGAT becoming the dominant enzyme form after 14 days. The entire activity of NADH-GOGAT and Fd-GOGAT was confined to the plaslid stroma. The plastid membrane fraction contained 37% of the NADPH-GOGAT activity. Isolated plastids synthesized glutamate from 2-ketoglutarate and glutamine, and glucose-6-phosphate and 6-phosophogluconate clearly stimulated this process. It is supposed that the synthesis of glutamate in Pisum arvense root plastids may be dependent on the intensity of the carbohydrates conversion in the pentose phosphate pathway.
Vertical variability of selected macrostructural properties of juvenile wood organization in trunks of Scots pine (Pinus sylvestris L.) trees
Authors: Tomczak Arkadiusz , Pozdrowski Witold , Jelonek Tomasz , Stypuła Ireneusz
Published: April 2013

The study makes an attempt to analyse the width of annual rings, the width of the latewood zone and the proportion of the latewood within juvenile wood along trunks of Scots pine (Pinus sylvestris L.) trees and to verify the hypothesis about the heterogeneous properties of juvenile wood in a single trunk. It was found that the above-mentioned macrostructural elements of wood structure showed a curvilinear correlation with the height of measurement points along the tree trunk. As the distance from the base of trunk increased, the width of the annual ring and the width of the latewood zone decreased, while the proportion of the latewood increased. These types of changes can affect positively physical and mechanical properties of wood tissue. It can be assumed that there is a mechanism which modifies properties of juvenile wood causing axial diversification of the analysed type of wood tissue. It is probable that axial heterogeneity results in advantageous changes in the mechanics of the tree trunk.
The effect of dominant species on numbers and agę structure of Iris sibirica L. population on blue moor-grass meadow in southern Poland
Authors: Kostrakiewicz Kinga
Published: April 2013

Two populations of Iris sibirica, a clonal species protected by law in Poland, occurring in patches of Molinietum caeruleae, of similar floristic composition although with different dominant species, were studied. In the Stanisławice locality, species with a high competitive potential prevailed, contrary to the Opatkowice locality, where the species of low competitive potential dominated. It was established that vegetative propagation ensures the continued presence of populations in both localities, although the proximity of plants with high competitive potential limits the vegetative propagation of ramet clusters of Iris sibirica. Despite the high level of seed production, the recruitment of seedlings in both patches is possible only in artificially created gaps. The field observations support the conclusion that creating gaps allowing for germination of seeds and development of seedlings, as well as eliminating expansive neighbours allowing proliferation of ramet clusters of Iris sibirica, is an affective way of protecting populations of this species.
Morphological variability of oospores of Chara baueri A. Braun (Characeae)
Authors: Hutorowicz Andrzej
Published: April 2013

The shape and size of present-day specimens of Chara baueri are described. C. baueri is believed to have practically died out in Europe. Oospores of specimens of C. baueri collected in Kazachstan were subjected to morpholgical analysis. Data recorded included oospore length, oospore diameter, the ratio of length to diameter, the number of lateral convolutions, ridge width, the width of the fossules at the equator, and the diameter of the basal pore. Variation in oospore length and the number of convolutions was higher than had been previously reported in the literature, whereas variation in oospore width was identical to previous reports.
Distribution of Chara braunii Gmellin 1826 (Charophyta) in Poland
Authors: Urbaniak Jacek
Published: April 2013

The distribution and ecology of Chara braunii Gmellin 1826 in Poland is described, based on herbaria collections, literature data and own investigations. Maps showing the distribution of Ch. braunii are presented, as well as a list of localities with brief descriptions of the habitats. Additionally, some remarks on the distribution limit in the northern hemisphere are given.
Phenolic compounds and properties of antioxidants in grapevine roots (Vitis vinifera L.) under low-temperature stress followed by recovery
Authors: Weidner Stanisław , Kordala Edyta , Brosowska-Arendt Wioletta , Karamać Magdalena , Kosińska Agnieszka , Amarowicz Ryszard
Published: April 2013

The research has been performed on roots of Vitis vinifera, cv. Himrod, obtained from seedlings grown under chill stress conditions (+10oC in the day and +7oC at night), under optimum conditions (+25oC in the day and +18oC at night) and from seedling which underwent a recover period after the chill stress treatment. The purpose of the study has been to determine quantitative and qualitative changes in phenolic compounds as well as to demonstrate changes in antiradical properties of extracts from grapevine roots, which appeared as a result of chill stress and during recovery under the optimum conditions following the stress. Phenolic compounds from grapevine roots were extracted using 80% acetone. The total content of phenolics was determined by colorimetry. The content of tannins was tested by precipitation with bovine serum albumin. The reducing power as well as DPPH• free radical and ABTS+• cation radical scavenging activity of the extracts were also tested. In order to identify phenolic compounds present in the extracts the RP-HPLC technique was employed. The tested material was found to contain tannins and three identified phenolic acids: ferulic, caffeic and p-coumaric ones. The latter occurred in the highest concentrations (from 4.46 to 6.28 µg/g fresh matter). Ferulic acid appeared in smaller amounts (from 1.68 to 2.65 µg/g fresh matter), followed by caffeic acid (from 0.87 to 1.55 µg/g fresh matter). Significantly less total phenolic compounds occurred in roots of seedlings subjected to chill stress. However, the total content of these compounds increased significantly in roots of plants which underwent recovery after chill stress. Concentration of tannins was determined by two methods. The content of condensed tannins was depressed in roots as a result of low temperature stress, whereas the content of condensed and hydrolysing tannins (determined via the BSA method) rose under chill stress conditions. A significant increase in tannins in root extracts (determined with both methods) was found during the recovery process after the stress. The three identified phenolic acids appeared in grapevine roots as ester-bound compounds. It has been demonstrated that the content of phenolic acids significantly fell as a result of low temperatures, but increased during recovery after chill stress. The weakest ability to scavenge DPPH• and ABTS+• free radicals as well as the reducing power were shown by the extract obtained from grapevine roots from the seedlings subjected to chill stress. Both free radical scavenging activity and reducing power were observed to increase considerably during recovery after stress. This seems to prove that during the recovery process following chill stress the synthesis of antioxidative compounds in grapevine roots is much more intensive.
Flora of toxic depots in selected industrial zones
Authors: Petřík Petr , Soudek Petr , Benešová Dagmar , Najmanová Petra , Najman Michal , Vaněk Tomáš
Published: April 2013

Floristic composition in three industrial areas with soils contaminated by heavy metals (As, Cd, Cu, Hg, Pb, Zn) and organic pollutants (polychlorinated biphenyls) was studied. The content of Pb was only significantly correlated with the floristic composition and explained 13.8% of its variability considering spatial dependency of the sites. No correlation was found for PCBs. Altogether, 237 plant vascular species were found at three study sites (117, 133 and 105, respectively). The three study areas differed in their species composition represented by their own characteristic species. The gradient in the content of natives/non-natives, species number, prevailing life forms and indicator values for plant species investigated was revealed. Based on our results, for phytoremediation purposes we can select productive plant species with high biomass and ability to accumulate large amounts of heavy metals or organic compounds and surviving on soils with low mineral content.
Pollen morphology of Amygdalus L. (Rosaceae) in Iran
Authors: Vafadar Mahnaz , Attar Farideh , Maroofi Hosein , Mirtadzadini Mansur
Published: April 2013

Pollen grain of 16 species and three hybrids of the genus Amygdalus L., representing two subgenera and two sections distributed in Iran were examined by light and scanning electron microscopy. All pollen grains are tricolporate. The shape of grains varies from subprolate through prolate. Regarding outline, in polar view, pollen grains are triangular-circular and in equatorial view, elliptic. Regarding sculpturing of exine, the frequent type like many members of family Rosaceae is striate with or without perforations that can be subdivided into three subtypes: type I (A-B), type II (A-B) and type V. In three species, A. trichamygdalus, A. spinosissima and A. orientalis, exine sculpture type is completely different. In the first species is rugulate, in the second species is reticulate and in A. orientalis, it is gemmate-perforate. Ornamentation of ridges (muri) in the striate sculpture is parallel to ectocolpus. Number of perforations in tectum, diameter of them, striae intervals and the thickness of ridges varies among studied taxa. The striae have different depth and slope. Results showed that among pollen grain characters, shape is useful character solely for separating of taxonomic ranks in Iranian Amygdalus specially in subgeneric or section level.
Effect of Meta-topolin on in vitro propagation of Pelargonium × hortorum and Pelargonium × hederaefolium cultivars
Authors: Wojtania Agnieszka
Published: April 2013

July and September. The most efficient regeneration and axillary multiplication were achieved on the medium supplemented with meta-topolin. The application of BAP caused a lower regeneration potency of explants and resulted in a decrease of shoot quality with every subculture. Four of the six cultivars showed growth inhibition after three months of growth on BAP-medium. The highest multiplication rate (2.7-4.7 depending on genotype) and the high quality of shoots were noted on the medium supplemented with mT (0.5-1.0 mg l-1). It is also very important to note that mT had stimulating effect on organogenesis in P. × hederaefolium and P. × hortorum cultivars over the long term. Moreover, meta-topolin had no after-effect on the growth and inhibition of rooting. Only one cultivar ("Sofie Cascade") rooted better on control medium without auxin. In case of the other cultivars, IBA added in concentrations of 0.01-0.1 mg l-1 had a stimulating effect on root production. The higher level of auxin inhibited root formation, stimulated senescence of shoots and had a negative after-effect on acclimatization in greenhouse conditions.
Effect of osmotic stress and post-stress recovery on the content of phenolics and properties of antioxidants in germinating seeds of grapevine Vitis californica
Authors: Weidner Stanisław , Brosowska-Arendt Wioletta , Szczechura Wojciech , Karamać Magdalena , Kosińska Agnieszka , Amarowicz Ryszard
Published: April 2013

The tested material consisted of grapevine Vitis californica stratified seeds germinated under optimum conditions (+25°C in water), under osmotic stress (-0.2 MPa in PEG solution) and submitted to recovery after stress (+25°C in water). The germinating seeds were determined to contain tannins, catechins and the following phenolic acids: gallic, caffeic, p-coumaric and ferulic. The acids occurred in free, ester- and glycoside-bound forms. The dominant form of phenolic acids was the ester-bound fraction. Gallic acid was the most abundant phenolic acid in germinating seeds, while ferulic acid appeared in the smallest amounts. Our analysis of tannins demonstrated that osmotic stress depressed their concentration. Presence of catechin group compounds such as catechin and epicatechin was also determined. In each sample epicatechin was dominant. The total concentration of catechin increased under stress conditions and declined during post-stress recovery. Catechins are a constituent of tannins and their increase under osmotic stress is most probably caused by the breakdown of some tannins in seeds germinating under stress conditions. Samples submitted to osmotic stress were also found to contain less of total phenolic compounds, whereas in samples which underwent post-stress recovery the total level of phenolic compounds increased. Compared to extracts from seeds germinating under optimum conditions, osmotic stress depressed the capacity of extract to scavenge DPPH● (2,2-diphenyl-1-picrylhydrazyl) and ABTS●+ – 2,2-Azino-bis (3-etylbenzothiazoline-6-sulfonic acid) free radicals, but the antioxidant activity rose in seeds submitted to recovery after stress. Positive correlation was therefore demonstrated between the total content of phenolic acids in germinating grapevine seeds and the reducing power of extracts obtained from these seeds and their free radical scavenging activity. The results suggest that osmotic stress inhibits the activity of antioxidizing enzymes in germinating grapevine seeds. Thus, the antioxidative defence system is largely blocked under osmotic stress. It seems that a very high oxidoreductive potential in grapevine tissues prior to occurrence of osmotic stress is essential for maintaining proper homeostasis of oxidation and reduction reactions.
Quantifying Cellular Dynamics by Fluorescence Resonance Energy Transfer (FRET) Microscopy
Authors: Grecco Hernán E. , Bastiaens Philippe I. H.
Published: April 2013

The cell is a spatially organized system whose function emerges from the complex interaction of molecular components. Such local interaction of nanometer‐sized molecules generates patterns that span throughout the cell. Those patterns, in turn, regulate the molecular interactions. Understanding such simultaneous bidirectional causation requires quantifying the spatio‐temporal progression of biochemical reactions in the context of a living cell. Due to its ability to resolve micrometer‐sized structures, biological microscopy has been instrumental to the discovery and understanding of living systems. Functional fluorescence microscopy allows a cellular dynamic topographic map of proteins to be overlaid with topological information on the causality that determines protein state. Here we describe how Förster/fluorescence resonance energy transfer (FRET) can be used to measure the phosphorylation state of proteins in the context of the cell. Curr. Protoc. Neurosci. 63:5.22.1‐5.22.14. © 2013 by John Wiley & Sons, Inc.
ITO‐Free and Fully Solution‐Processed Semitransparent Organic Solar Cells with High Fill Factors
Authors: Guo Fei , Zhu Xiangdong , Forberich Karen , Krantz Johannes , Stubhan Tobias , Salinas Michael , Halik Marcus , Spallek Stefanie , Butz Benjamin , Spiecker Erdmann , Ameri Tayebeh , Li Ning , Kubis Peter , Guldi Dirk M. , Matt Gebhard J. , Brabec Christoph J.
Published: April 2013

Organic photovoltaic (OPV) solar cells that can be simply processed from solution are in the focus of the academic and industrial community because of their enormous potential to reduce cost. One big challenge in developing a fully solution‐processed OPV technology is the design of a well‐performing electrode system, allowing the replacement of ITO. Several solution‐processed electrode systems were already discussed, but none of them could match the performance of ITO. Here, we report efficient ITO‐free and fully solution‐processed semitransparent inverted organic solar cells based on silver nanowire (AgNW) electrodes. To demonstrate the potential of these AgNW electrodes, they were employed as both the bottom and top electrodes. Record devices achieved fill factors as high as 63.0%, which is comparable to ITO based reference devices. These results provide important progress for fully printed organic solar cells and indicate that ITO‐free, transparent as well as non‐transparent organic solar cells can indeed be fully solution‐processed without losses.
Persistent Hypertension Despite Successful Dilation of a Stenotic Renal Artery in a Boy With Neurofibromatosis Type 1
Authors: Ueda Keisuke , Awazu Midori , Konishi Yoriko , Takenouchi Toshiki , Shimozato Sachiko , Kosaki Kenjiro , Takahashi Takao
Published: April 2013

Hypertension is one of the major complications in neurofibromatosis type 1 (NF1). It is known to be caused by renal artery stenosis or pheochromocytoma. However, more than half of hypertensive patients with NF1 do not have either disorder. We report here on a 13‐year‐old male with NF1 who had hypertension and a stenosis of the right renal artery associated with elevated renal vein renin on the diseased side. He underwent percutaneous transluminal renal angioplasty. In spite of successful dilation of the artery and normalized renin level, high blood pressure persisted beyond 6 months requiring antihypertensive medication. His wide pulse pressure suggested arterial stiffness due to NF1 vasculopathy. We posit that the cause of hypertension in this patient was considered to be arterial stiffness ascribed to NF1 vasculopathy rather than renal artery stenosis. Increased pulse pressure supports the hypothesis. This marker of arterial stiffness can be assessed non‐invasively and should be evaluated routinely in NF1. © 2013 Wiley Periodicals, Inc.
Synthesis and aqueous solution properties of novel thermosensitive polyacrylamide derivatives
Authors: Zhu Yong , Xu Yuntao , Huang Guangsu
Published: April 2013

A series of novel thermosensitive polymers were synthesized with acrylamide and thermosensitive macromonomers by radical polymerization in water solution. The structures of the copolymers were characterized by 1H‐NMR. The effects of the polymer concentration, NaCl concentration, shear rate, and chemical structure on the thermothickening behavior of the polymer solution were investigated by advanced rheometry. The luminous transmittance of the solution with various polymer concentrations was tested by visible spectrometry. The results show that the thermothickening behavior was due to the phase separation of the polymer solution or intramolecular repulsions between the hydrophobic side chains and hydrophilic backbone at high temperatures. Finally, the thermothickening properties of the novel copolymer were studied under conditions simulating an underground oil reservoir. This novel copolymer is expected to be used as an oil‐displacing agent to enhance oil recovery in the future. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 766‐775, 2013
Vibrational Circular Dichroism Spectroscopy of Three Multidentate Nitrogen Donor Ligands: Conformational Flexibility and Solvent Effects
Authors: Dezhahang Zahra , Poopari Mohammad Reza , Xu Yunjie
Published: April 2013

A series of multidentate nitrogen donor ligands have been synthesized and characterized and their conformational distributions in solution have been investigated. Vibrational absorption (VA) and vibrational circular dichroism (VCD) spectroscopy, complemented with DFT calculations, have been used to probe the conformations of these important ligands in solution directly. These three ligands demonstrate very different conformational flexibility; the pyridine subunits and amine groups may adopt a number of different conformations. Experimental VA and VCD data measured in CDCl3 have been compared to the theoretical spectra of all possible most stable conformers. Solvent effects have been taken into account by using the implicit polarizable continuum model and explicit solvation model. The explicit hydrogen‐bonding solvation model is important for explaining the VCD sign‐reverse phenomenon in the amide I region. Good agreement has been achieved between experimental and predicted spectra for all three ligands; thus allowing detailed examination of the related conformational structures and distributions in solution.
Matricide and Stepmatricide Victims and Offenders: An Empirical Analysis of U.S. Arrest Data
Authors: Heide Kathleen M.
Published: April 2013

Almost all of the clinical and empirical literature on female parricide victims focuses on mothers killed, with only little information available on stepmothers murdered. This study is the first to compare the victim, offender, and case correlates in incidents when mothers and stepmothers were killed. Supplementary Homicide Report Data for 1976–2007 were used to investigate similarities and differences between the two female victim types in the United States. Similarities between stepmothers and mothers included that more than 70% were White and killed in single victim, single offender incidents. Their killers were adult sons in between 67% and 87% of incidents. Several significant differences emerged with respect to age, involvement in multiple offender incidents, and weapon use. Stepmothers and their stepchildren, relative to mothers and their offspring, were significantly younger. Sixty‐four percent of stepchildren, compared with 35% of biological children, were under age 25 at the time of their arrest for murder. A higher percentage of juveniles than adult killers was involved in multiple offender (MO) incidents involving mothers. Relative to their male counterparts, higher percentages of female juveniles were involved in MO incidents involving the deaths of mothers and stepmothers. A higher proportion of female adults, relative to their male counterparts, were involved in MO matricide incidents. Offenders who killed stepmothers, relative to those who killed mothers, were significantly more likely to use guns. Juvenile matricide offenders were significantly more likely to use firearms than their adult counterparts. Possible reasons for the differences are discussed in the conclusion. Copyright © 2013 John Wiley & Sons, Ltd.
Dictyostelium discoideum SecG interprets cAMP‐mediated chemotactic signals to influence actin organization
Authors: Garcia Rebecca , Nguyen Liem , Brazill Derrick
Published: April 2013

Tight control of actin cytoskeletal dynamics is essential for proper cell function and survival. Arf nucleotide binding‐site opener (ARNO), a mammalian guanine nucleotide exchange factor for Arf, has been implicated in actin cytoskeletal regulation but its exact role is still unknown. To explore the role of ARNO in this regulation as well as in actin‐mediated processes, the Dictyostelium discoideum homolog, SecG, was examined. SecG peaks during aggregation and mound formation. The overexpression of SecG arrests development at the mound stage. SecG overexpressing (SecG OE) cells fail to stream during aggregation. Although carA is expressed, SecG OE cells do not chemotax toward cAMP, indicating SecG is involved in the cellular response to cAMP. This chemotactic defect is specific to cAMP‐directed chemotaxis, as SecG OE cells chemotax to folate without impairment and exhibit normal cell motility. The chemotactic defects of the SecG mutants may be due to an impaired cAMP response as evidenced by altered cell polarity and F‐actin polymerization after cAMP stimulation. Cells overexpressing SecG have increased filopodia compared to wild type cells, implying that excess SecG causes abnormal organization of F‐actin. The general function of the cytoskeleton, however, is not disrupted as the SecG OE cells exhibit proper cell‐substrate adhesion. Taken together, the results suggest proper SecG levels are needed for appropriate response to cAMP signaling in order to coordinate F‐actin organization during development. © 2013 Wiley Periodicals, Inc
Protein Contacts and Ligand Binding in the Inward‐Facing Model of Human P‐Glycoprotein
Authors: Pajeva Ilza K. , Hanl Markus , Wiese Michael
Published: April 2013

The primary aim of this work was to analyze the contacts between residues in the nucleotide binding domains (NBDs) and at the interface between the transmembrane domains (TMDs) and the NBDs in the inward‐open homology model of human P‐glycoprotein (P‐gp). The analysis revealed communication nets through hydrogen bonding in the NBD and at the NBD–TMD interface of each half involving residues from the adenosine triphosphate (ATP) motifs and the coupling helices of the intracellular loops. Similar networks have been identified in P‐gp conformations generated by molecular dynamics simulation. Differences have been recorded in the networking between both halves of P‐gp. Many of the residue contacts have also been observed in the X‐ray crystal structures of other ATP binding cassette (ABC) transporters, which confirms their validity. Next, possible binding pockets involving residues of importance for the TMD–NBD communication were identified. By studying these pockets, binding sites were suggested for rhodamine 123 (R‐site) and prazosin (regulatory site) at the NBD–TMD interface that agreed with the experimental data on their location. Additionally, one more R‐site in the protein cavity was proposed, in accordance with the available biochemical data. Together with the previously suggested Hoechst 33342 site (H‐site), all sites were interpreted with respect to their effects on the protein ATPase activity, in correspondence with the experimental observations. Several residues involved in key contacts in the P‐gp NBDs were proposed for further targeted mutagenesis experiments.
Integrated Devices to Realize Energy Conversion and Storage Simultaneously
Authors: Chen Tao , Yang Zhibin , Peng Huisheng
Published: April 2013

Other forms of energy are generally converted to electric energy and then transported to electrochemical devices, where the energy is stored, by external electric wires. To further improve total energy conversion and storage efficiency, interest in simultaneously realize the energy conversion and storage in a single device has increased. This Concept describes recent progress in developing such novel integrated energy devices. Both planar and wire architectures are carefully illustrated with an emphasis on the “energy wire” which has been the focus of past developments due to its unique and promising applications, such as being woven into clothes or other complex structures by conventional textile technology. The current challenges and future directions of the integrated devices, particularly in the wire architecture, are summarized.
GI/Geom/1 queue based on communication model for mesh networks
Authors: Wei W. , Xu Q. , Wang L. , Hei X. H. , Shen P. , Shi W. , Shan L.
Published: April 2013

In mesh networks architecture, it should be permitted to visit the mobile client points. Whereas in mesh networks environment, the main throughput flows usually communicate with the conventional wired network. The so‐called gateway nodes can link directly to traditional Ethernet, depending on these mesh nodes, and can obtain access to data sources that are related to the Ethernet. In wireless mesh networks (WMNs), the quantities of gateways are limited. The packet‐processing ability of settled wireless nodes is limited. Consequently, throughput loads of mesh nodes highly affect the network performance. In this paper, we propose a queuing system that relied on traffic model for WMNs. On the basis of the intelligent adaptivenes, the model considers the influences of interference. Using this intelligent model, service stations with boundless capacity are defined as between gateway and common nodes based on the largest hop count from the gateways, whereas the other nodes are modeled as service stations with certain capacity. Afterwards, we analyze the network throughput, mean packet loss ratio, and packet delay on each hop node with the adaptive model proposed. Simulations show that the intelligent and adaptive model presented is precise in modeling the features of traffic loads in WMNs. Copyright © 2013 John Wiley & Sons, Ltd.
Adverse analytical findings with clenbuterol among U‐17 soccer players attributed to food contamination issues
Authors: Thevis Mario , Geyer Lina , Geyer Hans , Guddat Sven , Dvorak Jiri , Butch Anthony , Sterk Saskia S. , Schänzer Wilhelm
Published: April 2013

The illicit use of growth promoters in animal husbandry has frequently been reported in the past. Among the drugs misused to illegally increase the benefit of stock farming, clenbuterol has held a unique position due to the substance's composition, mechanism of action, metabolism, and disposition. Particularly clenbuterol's disposition in animals' edible tissues destined for food production can cause considerable issues on consumption by elite athletes registered in national and international doping control systems as demonstrated in this case‐related study. Triggered by five adverse analytical findings with clenbuterol among the Mexican national soccer team in out‐of‐competition controls in May 2011, the Fédération Internationale de Football Association (FIFA) initiated an inquest into a potential food contamination (and thus sports drug testing) problem in Mexico, the host country of the FIFA U‐17 World Cup 2011. Besides 208 regular doping control samples, which were subjected to highly sensitive mass spectrometric test methods for anabolic agents, 47 meat samples were collected in team hotels during the period of the tournament and forwarded to Institute of Food Safety, RIKILT.

In 14 out of 47 meat samples (30%), clenbuterol was detected at concentrations between 0.06 and 11 µg/kg. A total of 109 urine samples out of 208 doping control specimens (52%) yielded clenbuterol findings at concentrations ranging from 1–1556 pg/ml, and only 5 out of 24 teams provided urine samples that did not contain clenbuterol. At least one of these teams was on a strict ‘no‐meat’ diet reportedly due to the known issue of clenbuterol contamination in Mexico. Eventually, owing to the extensive evidence indicating meat contamination as the most plausible reason for the extraordinary high prevalence of clenbuterol findings, none of the soccer players were sanctioned. However, elite athletes have to face severe consequences when testing positive for a prohibited anabolic agent and sufficient supporting information corroborating the scenario of inadvertent ingestion are required to be acquitted from anti‐doping rule violations. Hence, governmental contribution is urgently needed to combat the illegal use of clenbuterol in stock breading. Copyright © 2013 John Wiley & Sons, Ltd.
Synthesis, Structures, and Optical Properties of Aza[4]helicenes
Authors: Zheng Yuan‐Hui , Lu Hai‐Yan , Li Meng , Chen Chuan‐Feng
Published: April 2013

A series of aza[4]helicenes have been conveniently synthesized in yields of 71–92 % by a one‐pot procedure involving the Pictet–Spengler reaction. The structures of the aza[4]helicenes were characterized by 1H and 13C NMR spectroscopy, mass spectrometry, and X‐ray crystallography. Moreover, it was found that the aza[4]helicenes self‐assemble into 2D layers or herringbone‐like structures in the solid state. In addition, the optical properties were investigated by UV and fluorescence spectroscopic methods.
Fully Organic Nanocomposites with High Thermoelectric Power Factors by using a Dual‐Stabilizer Preparation
Authors: Moriarty Gregory P. , Briggs Kenneth , Stevens Bart , Yu Choongho , Grunlan Jaime C.
Published: April 2013

The thermoelectric properties of fully organic nanocomposites were investigated, for which meso‐tetra(4‐carboxyphenyl) porphine (TCPP) and poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) were used as instrinically conductive and semiconducting stabilizers, respectively. The electrical conductivity (σ) of these dual‐stabilizer organic composites increased to approximately 9500 S m−1 as the concentrations of both the multiwalled carbon nanotubes (MWNTs) and PEDOT:PSS were increased. The thermopower (or Seebeck coefficient, S) and thermal conductivity, however, remained relatively unaffected by the increase in concentration (≈40 μV K−1 and ≈0.12 W m−1 K−1, respectively). Replacing MWNTs with double‐walled carbon nanotubes (DWNTs) increased σ and S to approximately 96 000 S m−1 and 70 μV K−1, respectively, at 40 wt % DWNTs. This study suggests that σ and S can be simultaneously tailored by using multiple stabilizing agents to affect the transport properties of the junctions between nanotubes. Combining semiconducting and intrinsically conductive molecules as CNT‐stabilizers has led to a power factor that is among the best for a completely organic, free‐standing film (≈500 μW m−1 K−2). These flexible, segregated‐network nanocomposites now exhibit properties that rival the more conventional inorganic semiconductors, particularly when normalized by the mass.
Comparative foliar epidermal morphology of the West African species of Amaranthaceae Juss.
Authors: Ogundipe O.T. , Kadiri A.B.
Published: April 2013

The species are generally amphistomatic except Pandiaka heudelotii that is hypostomatic. Anomocytic and paracytic stomatal types were mostly found but cyclocytic and diacytic types may accompany, especially in Cyathula spp. The anticlinal wall pattern varies from undulate to curved and curved‐straight in the family. Other useful epidermal features are peltate scales, trichomes of different types such as candelabra type, unicellular and multicellular conical types, long acicular glandular forms that may be tuberculate or non‐tuberculate and the filiform type; all can be employed at species level for delimitation purpose. Sub‐familial grouping of the genera is supported while monophyly and polyphyly suggested in Gomphrenoideae and Amarantheae respectively can be inferred from the extent of character variations in the species. An indented dichotomous key is presented for species delimitation. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Complex visual hallucinations and attentional performance in eye disease and dementia: a test of the Perception and Attention Deficit model
Authors: Makin S. M. , Redman J. , Mosimann U. P. , Dudley R. , Clarke M. P. , Colbourn C. , Collerton D.
Published: April 2013

Objective

This study aimed to test the prediction from the Perception and Attention Deficit model of complex visual hallucinations (CVH) that impairments in visual attention and perception are key risk factors for complex hallucinations in eye disease and dementia.

Methods

Two studies ran concurrently to investigate the relationship between CVH and impairments in perception (picture naming using the Graded Naming Test) and attention (Stroop task plus a novel Imagery task). The studies were in two populations—older patients with dementia (n = 28) and older people with eye disease (n = 50) with a shared control group (n = 37). The same methodology was used in both studies, and the North East Visual Hallucinations Inventory was used to identify CVH.

Results

A reliable relationship was found for older patients with dementia between impaired perceptual and attentional performance and CVH. A reliable relationship was not found in the population of people with eye disease.

Conclusions

The results add to previous research that object perception and attentional deficits are associated with CVH in dementia, but that risk factors for CVH in eye disease are inconsistent, suggesting that dynamic rather than static impairments in attentional processes may be key in this population. Copyright © 2013 John Wiley & Sons, Ltd.
Annual/semiannual variation of the ionosphere
Authors: Qian Liying , Burns Alan G. , Solomon Stanley C. , Wang Wenbin
Published: April 2013

We investigated the relationship between the systematic annual and semiannual variations in the ionosphere and thermosphere using a combination of data analysis and model simulation. A climatology of daytime peak density and height of the ionospheric F2 layer was obtained from GPS radio occultation measurements by the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) during 2007–2010. These measurements were compared to simulations by the NCAR Thermosphere‐Ionosphere‐Electrodynamics General Circulation Model (TIE‐GCM). Model reproduction of the ionospheric annual and semiannual variations was significantly improved by imposing seasonal variation of eddy diffusion at the lower boundary, which also improves agreement with thermospheric density measurements. Since changes in turbulent mixing affect both the thermosphere and ionosphere by altering the proportion of atomic and molecular gases, these results support the proposition that composition change drives the annual/semiannual variation in both the neutral and ionized components of the coupled system.
Hospital decentralisation in Romania: stakeholders' perspectives in the newsprint media
Authors: Popa Adela Elena
Published: April 2013

In the summer of 2010, Romania undertook a process of hospital decentralisation as part of the reform in the healthcare sector. The national newsprint media covered the process thoroughly. This paper is a study of how key stakeholders' views, attitudes, beliefs and attitudes towards decentralisation are represented in print media. 106 articles, published between June and September 2010, retrieved from the online databases of six leading national dailies were analysed. A mixed methodology was used in the data analysis stage. The qualitative data exploration identified five voices belonging to stakeholders involved directly or indirectly in the process: the representatives of central government, the local authorities (district and local councils, municipal mayors), health professionals (managers and physicians in hospitals), the media (journalists, analysts) and finally voices from civil society, professional associations and advocacy groups. These were the main actors negotiating the subjective meanings of the decentralisation process. An imbalance between these key actors were observed in the frequency, content and tone of the messages delivered in media during the four months. Central government and the local authorities were the most active voices, but the respective discourses differed significantly. An analysis of the accounts identified three main themes: the financial problem (hospitals liabilities and future spending), human resource in hospitals (the impact of decentralisation upon it) and the political character of the decentralisation. Copyright © 2013 John Wiley & Sons, Ltd.
Physicochemical regulation of endothelial sprouting in a 3D microfluidic angiogenesis model
Authors: Verbridge Scott S. , Chakrabarti Anirikh , DelNero Peter , Kwee Brian , Varner Jeffrey D. , Stroock Abraham D. , Fischbach Claudia
Published: April 2013

Both physiological and pathological tissue remodeling (e.g., during wound healing and cancer, respectively) require new blood vessel formation via angiogenesis, but the underlying microenvironmental mechanisms remain poorly defined due in part to the lack of biologically relevant in vitro models. Here, we present a biomaterials‐based microfluidic 3D platform for analysis of endothelial sprouting in response to morphogen gradients. This system consists of three lithographically defined channels embedded in type I collagen hydrogels. A central channel is coated with endothelial cells, and two parallel side channels serve as a source and a sink for the steady‐state generation of biochemical gradients. Gradients of vascular endothelial growth factor (VEGF) promoted sprouting, whereby endothelial cell responsiveness was markedly dependent on cell density and vessel geometry regardless of treatment conditions. These results point toward mechanical and/or autocrine mechanisms that may overwhelm pro‐angiogenic paracrine signaling under certain conditions. To date, neither geometrical effects nor cell density have been considered critical determinants of angiogenesis in health and disease. This biomimetic vessel platform demonstrated utility for delineating hitherto underappreciated contributors of angiogenesis, and future studies may enable important new mechanistic insights that will inform anti‐angiogenic cancer therapy. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A:2948–2956, 2013.
Polycyclic aromatic hydrocarbons—induced ROS accumulation enhances mutagenic potential of T‐antigen from human polyomavirus JC
Authors: Wilk Anna , Waligórski Piotr , Lassak Adam , Vashistha Himanshu , Lirette David , Tate David , Zea Arnold H. , Koochekpour Shahriar , Rodriguez Paulo , Meggs Leonard G. , Estrada John J. , Ochoa Augusto , Reiss Krzysztof
Published: April 2013

Polycyclic aromatic hydrocarbons (PAHs) are the products of incomplete combustion of organic materials, which are present in cigarette smoke, deep‐fried food, and in natural crude oil. Since PAH‐metabolites form DNA adducts and cause oxidative DNA damage, we asked if these environmental carcinogens could affect transforming potential of the human Polyomavirus JC oncoprotein, T‐antigen (JCV T‐antigen). We extracted DMSO soluble PAHs from Deepwater Horizon oil spill in the Gulf of Mexico (oil‐PAHs), and detected several carcinogenic PAHs. The oil‐PAHs were tested in exponentially growing cultures of normal mouse fibroblasts (R508), and in R508 stably expressing JCV T‐antigen (R508/T). The oil‐PAHs were cytotoxic only at relatively high doses (1:50–1:100 dilution), and at 1:500 dilution the growth and cell survival rates were practically unaffected. This non‐toxic dose triggered however, a significant accumulation of reactive oxygen species (ROS), caused oxidative DNA damage and the formation of DNA double strand breaks (DSBs). Although oil‐PAHs induced similar levels of DNA damage in R508 and R508/T cells, only T‐antigen expressing cells demonstrated inhibition of high fidelity DNA repair by homologous recombination (HRR). In contrast, low‐fidelity repair by non‐homologous end joining (NHEJ) was unaffected. This potential mutagenic shift between DNA repair mechanisms was accompanied by a significant increase in clonal growth of R508/T cells chronically exposed to low doses of the oil‐PAHs. Our results indicate for the first time carcinogenic synergy in which oil‐PAHs trigger oxidative DNA damage and JCV T‐antigen compromises DNA repair fidelity. J. Cell. Physiol. 228: 2127–2138, 2013. © 2013 Wiley Periodicals, Inc.
Suppression of interactions between prostate tumor cell‐surface integrin and endothelial ICAM‐1 by simvastatin inhibits micrometastasis
Authors: AL‐Husein Belal , Goc Anna , Somanath Payaningal R.
Published: April 2013

Cancer micrometastasis relies on the ability of cancer cells to secrete angiogenic modulators, to interact with the vascular endothelium, and to overcome the resistance offered by the endothelial‐barrier. Being an essential step prior to metastasis, blockage of micrometastasis can have potential applications in cancer therapy and metastasis prevention. Due to poorly known molecular mechanisms leading to micrometastasis, developing therapeutic strategies to target prostate cancer utilizing drugs that block micrometastasis is far from reality. Here, we demonstrate the potential benefits of simvastatin in the inhibition of prostate cancer micrometastasis and reveal the novel molecular mechanisms underlying this process. First, we showed that simvastatin inhibited the ability of human PC3 prostate cancer cells for transendothelial migration in vitro. Second, our data indicated that simvastatin modulates the expression of tumor‐derived factors such as angiopoietins and VEGF‐A at the mRNA and protein levels by the PC3 cells, thus preventing endothelial‐barrier disruption. Third, simvastatin directly activated endothelial cells and enhances endothelial‐barrier resistance. Apart from this, our study revealed that simvastatin‐mediated effect on PC3 micrometastasis was mediated through inhibition of integrin αvβ3 activity and suppression of interaction between prostate cancer cell integrin αvβ3 with endothelial ICAM‐1. J. Cell. Physiol. 228: 2139–2148, 2013. © 2013 Wiley Periodicals, Inc.
Preparation of 8‐hydroxyquinoline‐type composite chelating material HQ‐PHEMA/SiO2 and its adsorption behavior for heavy metal ions
Authors: Li Yanbin , Gao Baojiao , Fang Xiaolin
Published: April 2013

BACKGROUND

An 8‐hydroxyquinoline (HQ)‐type composite chelating material with high performance was designed and prepared. Monomer hydroxyethyl methacrylate (HEMA) was first grafted onto silica gel particles via surface‐initiated graft‐polymerization, forming grafted particles PHEMA/SiO2 with a high grafting degree. Subsequently, through the substitution reaction between 5‐chloromethyl‐8‐hydroxyquinoline (CHQ) and the grafted macromolecules PHEMA, HQ groups were bonded onto the grafted particles, obtaining the composite chelating material HQ‐PHEMA/SiO2. The chelating adsorption performance and mechanism of HQ‐PHEMA/SiO2 towards Cu2+ and Ni2+ ions was studied, and the adsorption thermodynamics was investigated.

RESULTS

The experimental results show that HQ‐PHEMA/SiO2 possesses a strong adsorption affinity for heavy metal ions owing to the high density of the HQ group, and for Cu2+ and Ni2+ ions, the adsorption capacities were up to 63.4 mg g−1 and 51.1 mg g−1, respectively. The adsorption behavior fits the Langmuir model, and the adsorption enthalpy change ΔH is positive, indicating endothermic chemisorption. The value of the entropy change ΔS is also positive, and the higher value of |TΔS| suggests that the adsorption process is entropically driven.

CONCLUSION

HQ‐PHEMA/SiO2 is a promising material for the effective removal of heavy metal ions from water. © 2013 Society of Chemical Industry