bluuebunny/crossref_metadata_2025 huggingface dataset:
The foliicolous lichen biota of the Democratic Republic of the Congo, with the description of six new species
Authors: VAN DEN BROECK Dries , LÜCKING Robert , ERTZ Damien
Published: February 2014

Six new species of foliicolous lichenized fungi are described as new to science from lowland rainforest in the Congo Basin:Bapalmuia serusiauxianaVan den Broeck, Lücking & Ertz (Pilocarpaceae) characterized by (7–)15(–19)-septate ascospores of (40–)50–65(–72)×1·5–2·5 μm,Microtheliopsis ramazanianaVan den Broeck, Lücking & Ertz (Microtheliopsidaceae) characterized by 1-septate ascospores of 13–16×3–5 μm,PhylloblastiaverheyenianaVan den Broeck, Lücking & Ertz (Verrucariaceae) characterized by 3-septate ascospores of 13–15(–17)×3·0–4·5 μm,Porina duduanaVan den Broeck, Lücking & Ertz (Porinaceae) characterized by 3-septate ascospores of 11·0–14·5×2·5–3·0 μm, perithecia 130–150(–170) μm diam. and a photobiont with angular-rounded and irregularly arranged cells,Porina gryseelsianaVan den Broeck, Lücking & Ertz (Porinaceae) characterized by orange-brown perithecia and 7–9(–12)-septate ascospores of 29–46×5·0–7·5 μm,Porina weghianaVan den Broeck, Lücking & Ertz (Porinaceae) characterized by the presence of disc-shaped isidia, yellow perithecia without apical appendages and (7–)9-septate ascospores of 33–50×5·0–6·5 μm. In addition, 53 species new for the Democratic Republic of the Congo are listed, including five species new for tropical Africa and six new for the Palaeotropics, thus raising the number of species known from the Democratic Republic of the Congo from 150 to 209. Keys are presented to all known species ofMicrotheliopsisand to species ofPorinawith disc-shaped isidia.
Pine forest lichens under eutrophication generated by a great cormorant colony
Authors: MOTIEJŪNAITĖ Jurga , IRŠĖNAITĖ Reda , ADAMONYTĖ Gražina , DAGYS Mindaugas , TARAŠKEVIČIUS Ričardas , MATULEVIČIŪTĖ Dalytė , KOREIVIENĖ Judita
Published: February 2014

Lichen community changes were investigated on trees within a colony of great cormorants (Phalacrocorax carbo sinensis) established in a pine forest on the Curonian Spit, western Lithuania. The impact of birds on the forest has altered the number and characteristics of substrata available to lichens. The lowest number of lichen species and occurrences was registered on trees in the most active part of the colony with the highest nest density. Lichen community patterns were most strongly related to P and Ca content in substrata and pH values. Some acidophytic species showed negative correlations, both with long-term and short-term ornithogenic influence. However, three acidophytes (Chaenotheca ferruginea, Lepraria incana, Coenogonium pineti) demonstrated an affinity for the transitional zone and recently occupied trees, and furthermore,C. pinetiapparently reacted positively to a short-term ornithogenic influence but negatively to a long-term one. These three lichens, along with algae, were the main, and often the only, components of epiphytic communities on trees at the edge of the colony and apparently indicated the crucial point of the acidophytic community under the increasing load of nutrients. All nitrophytic species showed an affinity for a long-term bird influence and reacted negatively to a short-term influence. Only free-living algae (predominating speciesDesmococcus olivaceus) showed a clear affinity for trees occupied by bird nests.Hypogymnia physodeswas found to be an indicator for early environmental changes following eutrophication. The study also showed that high concentrations of P did not have a mitigating effect on the detrimental impact brought about by increases in N and pH levels, but was possibly equally detrimental to acidophytic lichens.
Catenarina (Teloschistaceae, Ascomycota), a new Southern Hemisphere genus with 7-chlorocatenarin
Authors: SØCHTING Ulrik , SØGAARD Majbrit Zeuthen , ELIX John A. , ARUP Ulf , ELVEBAKK Arve , SANCHO Leopoldo G.
Published: February 2014

A new genus, Catenarina (Teloschistaceae, Ascomycota), with three species is described from the Southern Hemisphere, supported by molecular data. All species contain the secondary metabolite 7-chlorocatenarin, previously unknown in lichens. Catenarinadesolata is a non-littoral, lichenicolous species found on volcanic and soft sedimentary rock at 190–300 m in and near steppes in southernmost Chile and on the subantarctic island, Kerguelen. Catenarina vivasiana grows on maritime rocks and on rock outcrops in lowland Nothofagus forests, but has also been found at altitudes up to c. 580 m on moss and detritus on outcrops in Tierra del Fuego. The Antarctic species Caloplaca iomma is transferred to Catenarina based on chemical data; it grows on rocks near the coast in maritime Antarctica.
Pertusaria yunnana, a new species from south-west China
Authors: ZHAO Zun Tian , ZHAO Xin , GAO Wei , ZHOU Guo Li , ZHANG Lu Lu
Published: February 2014

Pertusaria yunnana G. L. Zhou & Lu L. Zhang from south-western China is described as new to science. This corticolous species is characterized by the white pruinose disciform apothecia, asci with 8 ascospores, and the presence of atranorin in addition to fumarprotocetraric acid. Related lichen taxa are discussed and a key to 21 corticolous species of Pertusaria with disciform apothecia and 8-spored asci is also provided.
How dear are deer volunteers: the efficiency of monitoring deer using teams of volunteers to conduct pellet group counts
Authors: Buesching Christina D. , Newman Chris , Macdonald David W.
Published: February 2014

Deer populations are increasing throughout the northern hemisphere, and unregulated numbers can jeopardize biodiversity and the economy. These populations are difficult to monitor using visual counts. Estimating densities from surveys of faecal pellets is reliable but time-consuming and thus, if carried out by professionals, expensive. Utilizing volunteers has clear advantages. Based on research from the UK (6 years) and Nova Scotia, Canada (4 years), we investigated the methodological refinements and training required to achieve reliable data when using volunteers. For safety reasons volunteers worked in teams of 5–10 (n = 611) under supervision of scientists. We compared faecal accumulation rate and faecal standing crop surveys using 10 × 10 m quadrats. Both methods produced similar estimates of density, but because of significant time savings and greater volunteer enjoyment we favour faecal standing crop over faecal accumulation rate surveys. Volunteer teams surveyed quadrats significantly faster than a single professional but needed significantly longer to reach and stake out new quadrats. On average, teams found 68% of all droppings. Performance of individuals was affected by training, gender, and willingness and aptitude to survey. After five quadrats men scored significantly higher than women but this difference was reduced after 20 quadrats. Age did not affect performance but willingness and aptitude correlated with ability to find and identify droppings. We conclude that volunteers can monitor deer effectively but that techniques should be modified. The provision of context, training, supervision and verification by a professional are essential. Because of the drain on scientists’ time, cost-effective volunteer deployment is a question of scale.
Tracking and replication of hand movements by teleguided intelligent manipulator robot
Authors: Hussain A. T. , Ahmed S. Faiz , Hazry D.
Published: February 2014

In this paper, a new method is presented that allows an intelligent manipulator robotic system to track a human hand from far distance in 3D space and estimate its orientation and position in real time with the goal of ultimately using the algorithm with a robotic spherical wrist system. In this proposed algorithm, several image processing and morphology techniques are used in conjunction with various mathematical formulas to calculate the hand position and orientation. The proposed technique was tested on Remote teleguided virtual Robotic system. Experimental results show that proposed method is a robust technique in terms of the required processing time of estimation of orientation and position of hand.
State-Led Urbanization in China: Skyscrapers, Land Revenue and “Concentrated Villages”
Authors: Ong Lynette H.
Published: February 2014

This article examines the rationale behind municipal and local governments' pursuance of urbanization, and the political and socio-economic implications of the policy to move villagers from their farmland into apartment blocks in high-density resettlement areas, or “concentrated villages.” It provides evidence of an increasing reliance by municipal and local governments on land revenues and the financing of urban infrastructure by the governments' land-leasing income. Following their relocation to apartment blocks, villagers complain that their incomes fall but their expenditures rise. Moreover, although they cede rights to the use of their farmland to the government, they are not given access to the state-provided social welfare to which urban residents are entitled. The paltry compensation which they receive for their land is insufficient to sustain them. Displaced or landless peasants are emerging as a distinctly disadvantaged societal group, deprived of the long-term security of either farmland or social welfare. The question of whether or not rural land rights should be freely traded is not as crucial to the future livelihoods of landless peasants as allowing them access to the full range of social welfare afforded to urban residents.
Cognitive Functioning in Young Children with Type 1 Diabetes
Authors: Cato M. Allison , Mauras Nelly , Ambrosino Jodie , Bondurant Aiden , Conrad Amy L. , Kollman Craig , Cheng Peiyao , Beck Roy W. , Ruedy Katrina J. , Aye Tandy , Reiss Allan L. , White Neil H. , Hershey Tamara
Published: February 2014

The aim of this study was to assess cognitive functioning in children with type 1 diabetes (T1D) and examine whether glycemic history influences cognitive function. Neuropsychological evaluation of 216 children (healthy controls,n= 72; T1D,n= 144) ages 4–10 years across five DirecNet sites. Cognitive domains included IQ, Executive Functions, Learning and Memory, and Processing Speed. Behavioral, mood, parental IQ data, and T1D glycemic history since diagnosis were collected. The cohorts did not differ in age, gender or parent IQ. Median T1D duration was 2.5 years and average onset age was 4 years. After covarying age, gender, and parental IQ, the IQ and the Executive Functions domain scores trended lower (bothp= .02, not statistically significant adjusting for multiple comparisons) with T1D relative to controls. Children with T1D were rated by parents as having more depressive and somatic symptoms (p< .001). Learning and memory (p= .46) and processing speed (p= .25) were similar. Trends in the data supported that the degree of hyperglycemia was associated with Executive Functions, and to a lesser extent, Child IQ and Learning and Memory. Differences in cognition are subtle in young children with T1D within 2 years of onset. Longitudinal evaluations will help determine whether these findings change or become more pronounced with time. (JINS, 2014,20, 238–247)
BUSINESS CYCLES AND FINANCIAL CRISES: THE ROLES OF CREDIT SUPPLY AND DEMAND SHOCKS
Authors: Nason James M. , Tallman Ellis W.
Published: February 2014

This paper explores the hypothesis that the sources of economic and financial crises differ from those of noncrisis business cycle fluctuations. We employ Markov-switching Bayesian vector autoregressions (MS-BVARs) to gather evidence about the hypothesis on a long annual U.S. sample running from 1890 to 2010. The sample covers several episodes useful for understanding U.S. economic and financial history, which generate variation in the data that aids in identifying credit supply and demand shocks. We identify these shocks within MS-BVARs by tying credit supply and demand movements to inside money and its intertemporal price. The model space is limited to stochastic volatility (SV) in the errors of the MS-BVARs. Of the 15 MS-BVARs estimated, the data favor a MS-BVAR in which economic and financial crises and noncrisis business cycle regimes recur throughout the long annual sample. The best-fitting MS-BVAR also isolates SV regimes in which shocks to inside money dominate aggregate fluctuations.
The effect of periconceptional undernutrition of sheep on the cognitive/emotional response and oocyte quality of offspring at 30 days of age
Authors: Abecia J. A. , Casao A. , Pascual-Alonso M. , Lobón S. , Aguayo-Ulloa L. A. , Meikle A. , Forcada F. , Sosa C. , Marín R. H. , Silva M. A. , Maria G. A.
Published: February 2014

Maternal periconceptional undernutrition is associated with altered development and increased risks of adverse outcomes in the offspring. This circumstance is normal in flocks under extensive farming systems, which depend on natural forage resources. The aim of this study was to determine the effect of periconceptional undernutrition in sheep on behavioral and reproductive aspects of the offspring. Eighty ewes were synchronized in estrus and allocated to two groups (n=40) to be fed diets that provided 1.5 (C) or 0.5 (L) times the requirements for maintenance. Ewes were mated and 7 days later fed the control diet until lambing. One month after lambing, 32 lambs were exposed to tests to determine their cognitive and emotional responses. Six ewe lambs were euthanized and in vitro maturation and fertilization procedures were performed. L ewes presented a significant reduction in prolificacy and fecundity (P<0.05) in comparison with C ewes. Mean LW at lambing of L lambs was significantly higher than C lambs (C: 3.80±0.11; L: 4.24±0.15 kg, P<0.05). Lambs born from C ewes spent more time walking than L lambs (P<0.05) in the isolation test, revealing a decrease in the locomotor activity of lambs born from undernourished ewes around conception. Ewe lambs from the undernourished ewes presented a total population of oocytes 2.3 times higher than ovaries from control ewe lambs (60.0±7.8 v. 140.0±18.5 oocytes; P<0.05). In conclusion, periconceptional undernutrition is able to produce an increment in the body weight and the oocyte population, and an alteration of the locomotor activity of the offspring.
Community mental health teams in low- and middle-income countries
Authors: Thara R. , John S. , Chatterjee S.
Published: February 2014

The dearth of trained mental health professionals and the huge gap in providing accessible services in many low- and middle-income countries have led to the identification of alternate providers of care in these countries. Community mental health teams seem to fill this lacuna in some of these places. This editorial addresses issues of the need for such teams, their composition, responsibilities and limitations. With adequate training, these teams are able to carry out a broad array of tasks such a case identification, referrals, elementary counselling, family support and psychosocial interventions. While these teams are generally found to be enthusiastic, they require periodic monitoring and support with which they can well be a critical element of the mental health care team.
Werden Ängste und depressive Symptome bei Kindern und Jugendlichen in der Schule übersehen?
Authors: Bilz Ludwig
Published: February 2014

Lehrkräfte können eine wichtige Rolle bei der Früherkennung psychischer Fehlentwicklungen bei Kindern und Jugendlichen spielen. Diese Studie untersucht, wie Lehrpersonen internalisierende vs. externalisierende Symptome bei Schülern wahrnehmen. Hierfür wurde 345 Sechst- und Zehntklässlern der Strengths and Difficulties Questionnaire (SDQ) vorgelegt und parallel wurden die Lehrkräfte befragt, bei welchen zwei Schülern ihrer Klasse sie am ehesten emotionale und bei welchen zwei Schülern sie am ehesten Verhaltensstörungen vermuten. Die Ergebnisse zeigen, dass Lehrkräfte mäßig in der Lage sind, psychische Beschwerden bei ihren Schülern wahrzunehmen. Die Übereinstimmung zwischen Lehrerurteil und Selbstangabe fällt bei externalisierenden Problemen höher aus als bei internalisierenden. Weiterhin liegen die Einschätzungen der Lehrkräfte bei Mädchen näher an den selbst berichteten Beschwerden als bei den Jungen. Es werden Schlussfolgerungen für die Lehrerprofessionalisierung und für zukünftige Forschungsbemühungen präsentiert.
Auf dem Weg zur Professionalisierung: Anforderungen im Lehramtsstudium
Authors: Bohndick Carla , Buhl Heike M.
Published: February 2014

Obwohl die Lehrerbildung in den letzten Jahren vermehrt im Fokus von Untersuchungen stand, ist über die Anforderungen im Lehramtsstudium wenig bekannt. Diese werden hier anhand der Methodik zur Ermittlung von Anforderungen an Studierende (MEVAS; Hell, Ptok & Schuler, 2007 ) analysiert und in Zusammenhang mit 5 Studienerfolgskriterien gesetzt. An der Online-Befragung, in der verschiedene Anforderungen hinsichtlich ihres Erfüllungsgrads eingeschätzt wurden, nahmen 686 Lehramtsstudierende einer mittelgroßen Universität in Nordrhein-Westfalen teil. Die Daten wurden faktoren- und regressionsanalytisch ausgewertet. Es zeigten sich 17 Anforderungsdimensionen, von denen bei gemeinsamer Betrachtung sechs aufgrund ihres positiven Zusammenhangs mit verschiedenen Studienerfolgskriterien bedeutsam sind: Selbstdisziplin, Umgang mit Belastungen, Interesse, Angebotsnutzung, allgemeine kognitive Fähigkeiten und Theorie-Praxis-Verzahnung.
Interdisziplinäre Beschulung und die Struktur des akademischen Selbstkonzepts in den naturwissenschaftlichen Fächern
Authors: Jansen Malte , Schroeders Ulrich , Lüdtke Oliver , Anand Pant Hans
Published: February 2014

Das akademische Selbstkonzept wird als multidimensionales, fachspezifisches Konstrukt aufgefasst. Welchen Einfluss die schulische Fächerstruktur auf die Struktur des Selbstkonzepts hat, ist jedoch noch unklar. In diesem Beitrag wird untersucht, ob bei Schülern, die interdisziplinären Naturwissenschaftsunterricht erhalten, ein weniger stark ausdifferenziertes naturwissenschaftliches Selbstkonzept vorliegt als bei Schülern, die Unterricht in Biologie, Chemie und Physik getrennt erhalten. Dazu wurden 326 Schüler, die in der gesamten Sekundarstufe im Fächerverbund beschult wurden, mit einer Vergleichsgruppe von 4361 fächergetrennt beschulten Schülern verglichen. Mit konfirmatorischen (Mehrgruppen-) Faktorenanalysen wird gezeigt, dass Schüler beider Gruppen in ihrem Selbstkonzept zwischen den drei Fächern differenzieren, in der interdisziplinär beschulten Gruppe die Zusammenhänge zwischen den Selbstkonzeptfaktoren aber deutlich höher sind. Interdisziplinärer Unterricht scheint also mit einer Vereinheitlichung der Selbstkonzeptstruktur auf Schülerseite einherzugehen. Implikationen für die Selbstkonzepttheorie werden diskutiert.
The emerging role of mTOR signalling in antibacterial immunity
Authors: Abdel‐Nour Mena , Tsalikis Jessica , Kleinman David , Girardin Stephen E
Published: February 2014

Mammalian target of rapamycin (mTOR) is a central regulator of cellular metabolic homeostasis that is highly conserved in evolution. Recent evidence has revealed the existence of a complex interplay between mTOR signalling and immunity. We review here the emerging role of mTOR signalling in the regulation of Toll‐like receptor‐dependent innate responses and in the activation of T cells and antigen‐presenting cells. We also highlight the importance of amino‐acid starvation‐driven mTOR inhibition in the control of autophagy and intracellular bacterial clearance.
Dissecting mammalian immunity through mutation
Authors: Siggs Owen M
Published: February 2014

Although mutation and natural selection have given rise to our immune system, a well‐placed mutation can also cripple it, and within an expanding population we are recognizing more and more cases of single‐gene mutations that compromise immunity. These mutations are an ideal tool for understanding human immunology, and there are more ways than ever to measure their physiological effects. There are also more ways to create mutations in the laboratory, and to use these resources to systematically define the function of every gene in our genome. This review focuses on the discovery and creation of mutations in the context of mammalian immunity, with an emphasis on the use of genome‐wide chemical and CRISPR/Cas9 mutagenesis to reveal gene function.
Lactate-mediated glia-neuronal signalling in the mammalian brain
Authors: Tang F. , Lane S. , Korsak A. , Paton J. F. R. , Gourine A. V. , Kasparov S. , Teschemacher A. G.
Published: February 2014

Astrocytes produce and releaseL-lactate as a potential source of energy for neurons. Here we present evidence thatL-lactate, independently of its caloric value, serves as an astrocytic signalling molecule in the locus coeruleus (LC). The LC is the principal source of norepinephrine to the frontal brain and thus one of the most influential modulatory centers of the brain. Optogenetically activated astrocytes releaseL-lactate, which excites LC neurons and triggers release of norepinephrine. ExogenousL-lactate within the physiologically relevant concentration range mimics these effects.L-lactate effects are concentration-dependent, stereo-selective, independent ofL-lactate uptake into neurons and involve a cAMP-mediated step.In vivoinjections ofL-lactate in the LC evokes arousal similar to the excitatory transmitter,L-glutamate. Our results imply the existence of an unknown receptor for this ‘glio-transmitter’.
The vital role of constitutive GPCR activity in the mesolimbic dopamine system
Authors: Meye F J , Ramakers G M J , Adan R A H
Published: February 2014

The midbrain dopamine system has an important role in processing rewards and the stimuli associated with them, and is implicated in various psychiatric disorders. This system is tightly regulated by various G protein-coupled receptors (GPCRs). It is becoming increasingly clear that these receptors are not only activated by (endogenous) agonists but that they also exhibit agonist-independent intrinsic constitutive activity. In this review we highlight the evidence for the physiological role of such constitutive GPCR activity (in particular for cannabinoid 1, serotonin 2C and mu-opioid receptors) in the ventral tegmental area and in its output regions like the nucleus accumbens. We also address the behavioral relevance of constitutive GPCR signaling and discuss the repercussions of its abolition in dopamine-related psychiatric diseases.
Retracted Article: A simple rhodamine-based dual signalling reversible molecular switch for recognition of Al(III) with Promising applications for advanced logic operations – ‘OR’, ‘Keypad Lock’ & ‘INHIBIT’ logic function and cell-imaging studies†.
Authors: Mahammad Ali , Mistri Tarun , Alam Rabiul , Bhowmick Rahul , Mandal Sushil Kumar , Dolai Malay , Khuda-Bukhsh Anisur Rahman
Published: February 2014

A simple salicylaldimine-based receptor equipped with rhodamine moiety (L3) has been designed and synthesized for detection of Al3+ ions, which exhibits high sensitivity over other metal ions in aqueous buffer-methanol...
New insights into carbon dioxide interactions with benzimidazole-linked polymers
Authors: Altarawneh Suha , Behera S. , Jena Puru , El-Kaderi Hani M.
Published: February 2014

Computational studies reveal that the excellent performance of benzimidazole-linked polymers in selective carbon dioxide capture over methane and nitrogen is facilitated by several electrostatic interactions involving the Lewis basic sites and the aryl C–H of the benzimidazole units with CO2.
Harnessing G-tetrad scaffolds within G-quadruplex forming aptamers for fluorescence detection strategies
Authors: Sproviero Michael , Manderville Richard A.
Published: February 2014

Utility of internal fluorescent guanine replacements for effective signaling of thrombin binding.
Applications of biocatalytic arene ipso,ortho cis-dihydroxylation in synthesis
Authors: Lewis Simon E.
Published: February 2014

The dearomatising dihydroxylation of aromatic molecules mediated by arene dioxygenase enzymes can provide cyclohexadiene-diols that are versatile starting materials for organic synthesis.
Length-controlled synthesis and the photoluminescence of pre-perovskite PbTiO3 nanofibers
Authors: Yu Tingting , Ren Zhaohui , Gong Siyu , Jiang Shan , Chao Chunying , Li Xiang , Shen Ge , Han Gaorong
Published: February 2014

The introduced TEA solution modified the sol–gel process and decreased the length of PbTiO3 nanofibers during the subsequent hydrothermal reaction.
P7C3 and an unbiased approach to drug discovery for neurodegenerative diseases
Authors: Pieper Andrew A. , McKnight Steven L. , Ready Joseph M.
Published: February 2014

The P7C3 compounds emerged from an in vivo screen and were found to protect neurons in models of neurodegenerative disease.
Towards bacterial adhesion-based therapeutics and detection methods
Authors: Pera Núria Parera , Pieters Roland J.
Published: February 2014

Bacterial adhesion is an important first step towards bacterial infection and plays a role in colonization, invasion and biofilm formation.
Generation of spatiotemporal calcium patterns by coupling a pH-oscillator to a complexation equilibrium
Authors: Molnár István , Kurin-Csörgei Krisztina , Orbán Miklós , Szalai István
Published: February 2014

Calcium waves and patterns have been observed in the bromate–sulfite–ferrocyanide–CaEDTA reaction–diffusion system, where pH-oscillations drive binding and release of calcium ions.
Coordination polymers of organic polymers synthesized via photopolymerization of single crystals: two-dimensional hydrogen bonding layers with amazing shock absorbing nature
Authors: Garai Mousumi , Biradha Kumar
Published: February 2014

Crystalline coordination polymers of organic polymers (CPOPs) were synthesized via photopolymerization of Ag(i) coordination polymers of dienes which have a self-templating nature due to the formation of N–H⋯O hydrogen bonded layers.
Supramolecular gel from folic acid with multiple responsiveness, rapid self-recovery and orthogonal self-assemblies
Authors: Xing Pengyao , Chu Xiaoxiao , Ma Mingfang , Li Shangyang , Hao Aiyou
Published: February 2014

Supramolecular gel with multi-responsiveness, self-healing properties and concentration dependent orthogonal self-assemblies are constructed from folic acid via a solvent strategy.
Organization and intramolecular charge-transfer enhancement in tripodal tris[(pyridine-4-yl)phenyl]amine push–pull molecules by intercalation into layered materials bearing acidic functionalities
Authors: Melánová Klára , Cvejn Daniel , Bureš Filip , Zima Vítězslav , Svoboda Jan , Beneš Ludvík , Mikysek Tomáš , Pytela Oldřich , Knotek Petr
Published: February 2014

Intercalation of tripodal molecules into zirconium phosphate and zirconium 4-sulfophenylphosphonate leads to their organization in a layered system of the hosts.
A regio- and stereoselective entry to (Z)-β-halo alkenyl sulfides and their applications to access stereodefined trisubstituted alkenes
Authors: Liu Ge , Kong Lichun , Shen Ji , Zhu Gangguo
Published: February 2014

A regio- and stereoselective synthesis of (Z)-β-halo alkenyl sulfides via K2CO3-promoted hydrothiolation of haloalkynes has been reported, permitting a new entry to trisubstituted alkenes featuring the iterative cross-coupling of carbon–halide and carbon–sulfur bonds.
Modulating carnitine levels by targeting its biosynthesis – selective inhibition of γ-butyrobetaine hydroxylase
Authors: Rydzik Anna M. , Chowdhury Rasheduzzaman , Kochan Grazyna T. , Williams Sophie T. , McDonough Michael A. , Kawamura Akane , Schofield Christopher J.
Published: February 2014

Potent and selective inhibitors of γ-butyrobetaine hydroxylase were developed. Conformational changes on inhibitor binding rationalise regulation of γ-butyrobetaine hydroxylase activity by high levels of γ-butyrobetaine.
Colloidal synthesis and characterisation of Cu3SbSe3 nanocrystals
Authors: Liu Yike , Yang Jia , Gu Ening , Cao Tiantian , Su Zhenghua , Jiang Liangxing , Yan Chang , Hao Xiaojing , Liu Fangyang , Liu Yexiang
Published: February 2014

Cu3SbSe3 nanocrystals have been synthesized for the first time and show excellent photoelectrochemical properties.
The HicA toxin from Burkholderia pseudomallei has a role in persister cell formation
Authors: Butt Aaron , Higman Victoria A. , Williams Christopher , Crump Matthew P. , Hemsley Claudia M. , Harmer Nicholas , Titball Richard W.
Published: February 2014

TA (toxin–antitoxin) systems are widely distributed amongst bacteria and are associated with the formation of antibiotic tolerant (persister) cells that may have involvement in chronic and recurrent disease. We show that overexpression of the Burkholderia pseudomallei HicA toxin causes growth arrest and increases the number of persister cells tolerant to ciprofloxacin or ceftazidime. Furthermore, our data show that persistence towards ciprofloxacin or ceftazidime can be differentially modulated depending on the level of induction of HicA expression. Deleting the hicAB locus from B. pseudomallei K96243 significantly reduced persister cell frequencies following exposure to ciprofloxacin, but not ceftazidime. The structure of HicA(H24A) was solved by NMR and forms a dsRBD-like (dsRNA-binding domain-like) fold, composed of a triple-stranded β-sheet, with two helices packed against one face. The surface of the protein is highly positively charged indicative of an RNA-binding protein and His24 and Gly22 were functionality important residues. This is the first study demonstrating a role for the HicAB system in bacterial persistence and the first structure of a HicA protein that has been experimentally characterized.
Low‐resolution face recognition in uses of multiple‐size discrete cosine transforms and selective Gaussian mixture models
Authors: Huang Shih‐Ming , Chou Yang‐Ting , Yang Jar‐Ferr
Published: February 2014

Owing to losing the detailed information, the low‐resolution problem in face recognition degrades the recognition performance dramatically. To overcome this problem, a novel face‐recognition system has been proposed, consisting of the extracted feature vectors from the multiple‐size discrete cosine transforms (mDCTs) and the recognition mechanism with selective Gaussian mixture models (sGMMs). The mDCT could extract enough visual features from low‐resolution face images while the sGMM could exclude unreliable observation features in recognition phase. Thus, the mDCT and the sGMM can greatly improve recognition rate at low‐resolution conditions. Experiments are carried out on George Tech and AR facial databases in 16 × 16 and 12 × 12 pixels resolution. The results show that the proposed system achieves better performance than the existing methods for low‐resolution face recognition.
Power allocation for range‐only localisation in distributed multiple‐input multiple‐output radar networks – a cooperative game approach
Authors: Sun Bin , Chen Haowen , Wei Xizhang , Wang Hongqiang , Li Xiang
Published: February 2014

Power allocation in distributed multiple‐input multiple‐output radar is investigated for range‐only target localisation such that the determinant of Bayesian Fisher information matrix (B‐FIM) is maximised. The B‐FIM is derived from a signal model that incorporates the propagation path loss, the target reflectivity, the transmitted power and target prior information. The authors model the problem as a cooperative game and exploit the solution concept of Shapley value to distribute a given power budget among all transmitting radars for localisation and integrate the algorithm with a sequential Bayesian estimator to localise target. In numerical simulations, it is shown that uniform power allocation is not in general optimal. They illustrate the impact of the radar antenna geometry and target location prior density on the allocation results and demonstrate the superior performance of the proposed optimal power allocation scheme via Monte Carlo simulations.
Magnetic and microwave properties of U-type hexaferrite films with high remanence and low ferromagnetic resonance linewidth
Authors: Su Zhijuan , Bennett Steven , Hu Bolin , Chen Yajie , Harris Vincent G.
Published: February 2014

U-type barium hexaferrite films (Ba4Ni1.4Co0.6Fe36O60) were deposited on (0001) sapphire substrates by pulsed laser deposition. Microstructure and magnetic properties of the films were characterized by X-ray diffraction, scanning electron microscopy and vibrating sample magnetometry. Ferromagnetic resonance (FMR) measurements were performed at X-band. The results indicate an anisotropy field of ∼8 kOe, and the saturation magnetization (4πMs) of ∼3.6 kG. An optimal post-deposition annealing of films results in a strong (0 0 n) crystallographic texture and a high hysteresis loop squareness (Mr/Ms = 92%) leading to self biased properties. Furthermore, the highly self-biased ferrite films exhibited an FMR linewidth of ∼200 Oe. The U-type hexaferrite films having low microwave loss, low magnetic anisotropy field, and high squareness are a suitable alternative to Sc or In doped BaM ferrites that have been the choice material for self-biased microwave devices at X-band frequencies.
Ultrafast energy transfer from rigid, branched side-chains into a conjugated, alternating copolymer
Authors: Griffin Graham B. , Lundin Pamela M. , Rolczynski Brian S. , Linkin Alexander , McGillicuddy Ryan D. , Bao Zhenan , Engel Gregory S.
Published: February 2014

We present the synthesis and characterization of a benzodithiophene/thiophene alternating copolymer decorated with rigid, singly branched pendant side chains. We characterize exciton migration and recombination dynamics in these molecules in tetrahydrofuran solution, using a combination of static and time-resolved spectroscopies. As control experiments, we also measure electronic relaxation dynamics in isolated molecular analogues of both the side chain and polymer moieties. We employ semi-empirical and time-dependent density functional theory calculations to show that photoexcitation of the decorated copolymer using 395 nm laser pulses results in excited states primarily localized on the pendant side chains. We use ultrafast transient absorption spectroscopy to show that excitations are transferred to the polymer backbone faster than the instrumental response function, ∼250 fs.
Effects of easy axis direction on the magnetoimpedance properties of thin films with uniaxial anisotropy
Authors: Kikuchi H. , Takahashi Y. , Takahashi K. , Nakai T. , Hashi S. , Ishiyama K.
Published: February 2014

In this paper, we investigate the effects of easy axis direction against magnetoimpedance elements on stepped impedance properties. The angle between the easy axis and the element width is changed from 0° to 90°, and we examine the resulting impedance profiles. The magnetic field at which impedance is highest shifts to a lower field with increasing easy axis angles, which can be explained by a bias susceptibility theory. On the other hand, stepped impedance changes appear for the elements with an easy axis angle in the range of 35°–75°. We confirmed the stepped impedance property through our observations that those impedance jumps occur at transitional points of domain structure between single and multi domains by domain observations. The area where the impedance shows relatively low value and the element has multiple domains becomes narrower with increasing easy axis angles, which can be explained qualitatively on the basis of a simplified domain structure model.
Effects of deformation on the crystal field parameter of the Nd ions in Nd2Fe14B
Authors: Suzuki Tsuneaki , Toga Yuta , Sakuma Akimasa
Published: February 2014

Recently, the reduced coercivity of sintered Nd-Fe-B magnets was explained by distortion of the Nd-Fe-B region at the grain boundaries using classical molecular dynamics and phenomenological theory regarding magnetoelastic anisotropy. In this paper, we investigate how the deformation of Nd2Fe14B affects the crystal field parameter A20 of the Nd ions using first-principles calculations. By examining some cases of crystalline deformation, we confirm that the compressive deformation of Nd ions within the c-plane forces A20 to negative values. This is qualitatively consistent with the results of a previous study. However, quantitatively, the first-principles calculation shows that the magnetic anisotropy constant Ku is less sensitive to the distortion of Nd2Fe14B than suggested from the results obtained using classical and phenomenological theories.
Current dependence of spin torque switching rate based on Fokker-Planck approach
Authors: Taniguchi Tomohiro , Imamura Hiroshi
Published: February 2014

The spin torque switching rate of an in-plane magnetized system in the presence of an applied field is derived by solving the Fokker-Planck equation. It is found that three scaling currents are necessary to describe the current dependence of the switching rate in the low-current limit. The dependences of these scaling currents on the applied field strength are also studied.
Quantum state specific reactant preparation in a molecular beam by rapid adiabatic passage
Authors: Chadwick Helen , Hundt P. Morten , van Reijzen Maarten E. , Yoder Bruce L. , Beck Rainer D.
Published: February 2014

Highly efficient preparation of molecules in a specific rovibrationally excited state for gas/surface reactivity measurements is achieved in a molecular beam using tunable infrared (IR) radiation from a single mode continuous wave optical parametric oscillator (cw-OPO). We demonstrate that with appropriate focusing of the IR radiation, molecules in the molecular beam crossing the fixed frequency IR field experience a Doppler tuning that can be adjusted to achieve complete population inversion of a two-level system by rapid adiabatic passage (RAP). A room temperature pyroelectric detector is used to monitor the excited fraction in the molecular beam and the population inversion is detected and quantified using IR bleaching by a second IR-OPO. The second OPO is also used for complete population transfer to an overtone or combination vibration via double resonance excitation using two spatially separated RAP processes.
Performance enhanced miniaturized and electrically tunable patch antenna with patterned permalloy based magneto-dielectric substrate
Authors: Peng Yujia , Farid Rahman B. M. , Wang Xuehe , Wang Guoan
Published: February 2014

Perspective magneto-dielectric materials with high permeability are potential substrates to miniaturize the patch antenna without deteriorating its performance. Besides its high permeability at high frequency, patterned Permalloy (Py) also presents tunable permeability by applying DC current. A performance enhanced miniaturized and electrically tunable patch antenna with patterned Py thin film is first presented and developed in this paper. To suppress the magnetic loss, the Py thin film layer is consisted of an array of 2 μm × 2 μm square Py patterns between the copper patch antenna and dielectric substrate. The DC current could be applied directly on Py patterns through the copper strip lines beneath the Py patterns along the length of patch antenna. The copper strip lines are specially designed with the same width of Py patterns and the thickness much less than the skin depth at the operating frequency, which can reduce their deteriorating effects to the performance of antenna. The structure of the antenna is presented and simulated with high frequency structure simulator. The results show that compared with non-magnetic antenna, the performance of Py thin film based antenna is improved with 50% bandwidth increase from 4 MHz to 8 MHz and 1.2 dB gain enhancement from 1.16 dB to 2.36 dB. The resonant frequency of the antenna could be continuously tuned from 937 MHz to 911 MHz with the permeability of Py thin film changing from 1750 to 1 900 by applying the DC current.
Anisotropic spin structure along the easy axis of magnetization in epitaxially grown MnAs/GaAs(100) thin films
Authors: Song J. H. , Cui Y. , Lee J. J. , Ketterson J. B.
Published: February 2014

We grew epitaxial MnAs thin films on GaAs(100) substrates using molecular-beam epitaxy and investigated their magnetic properties. The crystal orientation of the film was type-B. Measurements of the film's magnetization revealed two-fold symmetric magnetic anisotropy on its surface, with the easy and hard directions of magnetization along GaAs[1¯10](MnAs[1¯1¯20]) and GaAs[110](MnAs[11¯02]), respectively. We found breakage of the uniaxial anisotropy in magnetization along the easy direction of magnetization for both the magnetization versus magnetic field and magnetization versus temperature measurements. We suggest that the origin of this peculiar pinned ferromagnetism in the MnAs layer is the spin-exchange interaction between the MnAs film and the ultra-thin Mn layer formed at the interface of MnAs film and GaAs(100) substrate.
Micromagnetic study on influence of the recording field direction on transition noise of stacked media
Authors: Kumagai S. , Sato S. , Sugita R.
Published: February 2014

The change in magnetization at the transition and the transition noise of the stacked media recorded with a single pole head without a trailing shield (SPH) and a head with a trailing shield (TSH) were investigated by using micromagnetic simulation. As a result, it was found that the linearity of the transition was higher and the transition noise was lower for the medium recorded with the TSH as compared with the medium recorded with the SPH. This is because stronger in-plane recording field of the TSH caused many small reversed domains. The relation between the magnetization distribution of the transition area and the direction of the recording head field reflected the relation between the domain structure of demagnetized media and the direction of the demagnetizing field.
A generalized tool for accurate time-domain separation of excited modes in spin-torque oscillators
Authors: Siracusano Giulio , La Corte Aurelio , Puliafito Vito , Finocchio Giovanni
Published: February 2014

We propose and develop an advanced signal processing technique that, combined with micromagnetic simulations, is able to deeply describe the non-stationary behavior of spin-torque oscillators, both in terms of time domain and spatial distribution of the magnetization dynamics. The Hilbert-Huang Transform is used for the identification of the time traces of each oscillation in a multimode excitation and enhanced with masking signals and the Ensemble Empirical Mode Decomposition. We emphasize that the technique developed here is general and can be used for any physical non-linear system in the presence of multimode dynamical excitation or intermittence.
Nitrogen-vacancy-center imaging of bubble domains in a 6-Å film of cobalt with perpendicular magnetization
Authors: Tetienne J.-P. , Hingant T. , Rondin L. , Rohart S. , Thiaville A. , Jué E. , Gaudin G. , Roch J.-F. , Jacques V.
Published: February 2014

We employ a scanning nitrogen-vacancy-center microscope to perform stray field imaging of bubble magnetic domains in a perpendicularly magnetized Pt/Co/AlOx trilayer with 6 Å of Co. The stray field created by the domain walls is quantitatively mapped with few-nanometer spatial resolution, with a probe-sample distance of about 100 nm. As an example of application, we show that it should be possible to determine the Bloch or Néel nature of the domain walls, which is of crucial importance to the understanding of current-controlled domain wall motion.
Growth process and magnetic properties of α-FeSe nanostructures
Authors: Li S. J. , Li D. , Jiang J. J. , Liu G. B. , Ma S. , Liu W. , Zhang Z. D.
Published: February 2014

Growth process and magnetic properties of PbO-type α-FexSe nanostructures with shape changing from nanocacti to nanopetals and then to nanosheets are investigated. With iron acetylacetonate [Fe(acac)3] and Se powder as raw materials, the diffusion process of Fe atoms dominates the synthesis of α-FexSe nanocacti following phase transitions from FeSe2 to Fe3Se4 and finally to α-FexSe. When a mixed solution containing Se precursor and Fe(acac)3 was used as the raw material, the formation of FeSe2 and Fe3Se4 can be avoided and, bended α-FexSe nanopetals can be prepared at 345 °C, which became flat nanosheets with a [001] preferred orientation as extending the reaction time from 1 to 4 h. No superconducting transition occurs in the α-FexSe (0.84 ≤ x ≤ 1.05) nanostructures due to composition heterogeneity or size effect. Magnetic measurements indicate that an antiferromagnetic component with a Néel point at about 45 K dominates the magnetic properties of the α-Fe0.87Se nanosheets.
Granular nanostructures and magnetic characteristics of FePt-TiO2/FePt-C stacked granular films
Authors: Ono Takuya , Moriya Tomohiro , Hatayama Masatoshi , Kikuchi Nobuaki , Okamoto Satoshi , Kitakami Osamu , Shimatsu Takehito
Published: February 2014

To realize a granular film composed of L10-FePt grains with high uniaxial magnetic anisotropy energy, Ku, and segregants for heat-assisted magnetic recording, the FePt-TiO2/FePt-C stacked film was investigated. The FePt-TiO2/FePt-C stacked film has well-isolated granular structure with average grain size of 6.7 nm because the FePt-TiO2 film follows the FePt-C template film in microstructural growth. However, the Ku value is quite low for total thickness of 9 nm: 5 × 106 erg/cm3. Exploration of the thickness dependence of L10-FePt(001) peaks in XRD spectra and cross-sectional TEM images suggest that degradation of the L10 ordering appears near the middle of the FePt-TiO2 layer. The EDX-STEM mapping reveals that Ti atoms exist within the FePt grains in addition to the grain boundary. This indicates the possibility that TiO2 tends to be incorporated into the FePt grains and that it prevents L10-ordering of the FePt grains along the normal-to-plane direction.
Dynamics of microemulsions bridged with hydrophobically end-capped star polymers studied by neutron spin-echo
Authors: Hoffmann I. , de Molina Paula Malo , Farago B. , Falus P. , Herfurth Christoph , Laschewsky André , Gradzielski M.
Published: February 2014

The mesoscopic dynamical properties of oil-in-water microemulsions (MEs) bridged with telechelic polymers of different number of arms and with different lengths of hydrophobic stickers were studied with neutron spin-echo (NSE) probing the dynamics in the size range of individual ME droplets. These results then were compared to those of dynamicic light scattering (DLS) which allow to investigate the dynamics on a much larger length scale. Studies were performed as a function of the polymer concentration, number of polymer arms, and length of the hydrophobic end-group. In general it is observed that the polymer bridging has a rather small influence on the local dynamics, despite the fact that the polymer addition leads to an increase of viscosity by several orders of magnitude. In contrast to results from rheology and DLS, where the dynamics on much larger length and time scales are observed, NSE shows that the linear polymer is more efficient in arresting the motion of individual ME droplets. This finding can be explained by a simple simulation, merely by the fact that the interconnection of droplets becomes more efficient with a decreasing number of arms. This means that the dynamics observed on the short and on the longer length scale depend in an opposite way on the number of arms and hydrophobic stickers.