bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of trisodium citrate on electrolytic deposition of hydroxyapatite coatings
Authors: Lin Dong‐Yang , Wang Xiao‐Xiang , Jiang Yong
Published: November 2010

Hydroxyapatite coatings were deposited on the titanium substrate by using various content Na3Cit as an organic modifier in electrolytes. The influence of the Na3Cit on the sizes of the HA crystals during electrolytic deposition was investigated under different molar ratio of Na3Cit to calcium ions. The experimental results showed that the size of HA crystal was well controlled by the addition of Na3Cit. When the molar ratio of Na3Cit to calcium ions was equal or greater than five, the obtained HA coating consisted of nanosized crystals. The HA nanoparticles were precipitated without a precursor phase when the molar ratio of Na3Cit to calcium ions was five; otherwise, the CaP coating experienced a phase conversion from octacalcium phosphate (OCP) to HA during the ELD. The effect of pH on saturation indexes with respect to hydroxyapatite, OCP, and dicalcium dihydrogen phosphate of these electrolytes was calculated by a computer program PHREEQC. The calculation showed the nucleation of OCP as the precursor during the deposition could be inhibited with increasing Na3Cit content in the electrolytes. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Biocompatibility and bioactivity enhancement of Ce stabilized ZrO2 doped HA coatings by controlled porosity change of Al2O3 substrates
Authors: Sima Felix , Ristoscu Carmen , Caiteanu Diana , Mihailescu Cristian N. , Stefan Nicolaie , Mihailescu Ion N. , Prodan Gabriel , Ciupina Victor , Palcevskis Eriks , Krastins Janis , Sima Livia E. , Petrescu Stefana M.
Published: November 2010

Al2O3 substrates with controlled porosity were manufactured from nanosized powders obtained by plasma processing. It was observed that when increasing the sintering temperature the overall porosity was decreasing, but the pores got larger. In a second step, Ce stabilized ZrO2 doped hydroxyapatite coatings were pulsed laser deposited onto the Al2O3 substrates. It was shown that the surface morphology, consisting of aggregates and particulates in micrometric range, was altered by the substrate porosity and interface properties, respectively. TEM studies evidenced that Ce stabilized ZrO2 doped HA particulates ranged from 10 to 50 nm, strongly depending on the Al2O3 porosity. The coatings consisted of HA nanocrystals embedded in an amorphous matrix quite similar to the bone structure. These findings were congruent with the increased biocompatibility and bioactivity of these layers confirmed by enhanced growing and proliferation of human mesenchymal stem cells. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Reconstitution of human MCF‐7 breast cancer cells with caspase‐3 does not sensitize them to action of CDK inhibitors
Authors: Węsierska‐Gądek Józefa , Hackl Stefan , Zulehner Nora , Maurer Margarita , Komina Oxana
Published: November 2010

Human MCF‐7 breast cancer cells are resistant to pro‐apoptotic stimuli due to caspase‐3 inactivation. On the other hand, they should be sensitive to agents like selective pharmacological inhibitors of cyclin‐dependent kinases (CDKs) that (re)activate p53 tumor suppressor protein because they harbor intact p53 pathways. In this study we examined whether reconstitution of caspase‐3 in MCF‐7 cells sensitizes them to inhibitors of CDKs, by analyzing the effects of roscovitine (ROSC) and olomoucine (OLO), two closely related selective pharmacological CDK inhibitors, on both mother MCF‐7 cells and a secondary mutant line, MCF‐7.3.28 that stably expresses human caspase‐3. The results show that ROSC is, as expected, much more potent than OLO. Surprisingly; however, ROSC and OLO reduced proliferation of parental MCF‐7 cells more strongly than caspase‐3‐proficient counterparts. Both inhibitors arrest human breast cancer cells at the G2‐phase of the cell cycle. Analysis of cell‐cycle regulators by immunoblotting revealed that ROSC strongly induces p53 protein activity by inducing its phosphorylation at Ser46 in the MCF‐7 cells lacking caspase‐3, but not in caspase‐3‐proficient cells. Furthermore, reconstitution of caspase‐3 in MCF‐7 cells neither elevates the mitochondrial apoptosis rate nor significantly increases caspases activity upon ROSC treatment. However, the stabilization of p53 in response to DNA damaging agents is the same in both caspase negative and positive MCF‐7 cells. Cytotoxic agents induce caspase‐3‐dependent apoptosis in caspase‐3‐proficient cells. These results indicate that reconstitution of MCF‐7 cancer cells with caspase‐3 sensitize them to the action of DNA damaging agents but not to ATP‐like pharmacological inhibitors of CDKs. J. Cell. Biochem. 112: 277–288, 2011. © 2010 Wiley‐Liss, Inc.
Cognitive triad as mediator in the hopelessness model? a three‐wave longitudinal study
Authors: Pössel Patrick , Thomas S. Denise
Published: November 2010

Several authors proposed that all elements of Beck's cognitive triad (1976) mediate the associations between inference style as described in the hopelessness model (Abramson, Alloy, & Metalsky, 1989) and depressive symptoms. Results of a 3‐wave longitudinal study indicate only a partial mediation model with all elements of the cognitive triad being associated with all inference styles, with depressive symptoms fitting the data best. Controlling for direct and indirect effects, no individual element of the cognitive triad mediates the association between inference styles and depressive symptoms. The partial mediation model is not stable across sex or clinical vs subclinical samples. In general, the data supports the integration of all three elements of the cognitive triad into the hopelessness model. © 2010 Wiley Periodicals, Inc. J Clin Psychol 00:1–7, 2010.
‘Youthscapes’ and escapes in rural Africa: Education, mobility and livelihood trajectories for young people in Eastern Cape, South Africa
Authors: Porter Gina , Hampshire Kate , Mashiri Mac , Dube Sipho , Maponya Goodhope
Published: November 2010

This paper draws attention to the significance of mobility in shaping the educational and livelihood trajectories of rural young people in sub‐Saharan Africa, with particular reference to a case study in Eastern Cape, South Africa. Young rural people commonly face both economic and political exclusions. As our case study illustrates, in the context of work demands, restricted basic education and poverty, the potential for escape, whether to secondary education or city jobs, is limited and in some respects highly gendered. We draw principally on ethnographic material from interviews with people aged 9–18 years, their parents, teachers and other key informants. Copyright © 2010 John Wiley & Sons, Ltd.
Phenolic compounds in seed oils
Authors: Van Hoed Vera
Published: November 2010

Traditionally, phenolic compounds are known to be abundant in fruits, vegetables and cereals. Recently, however, their presence in seed oils has been discovered and this offers interesting nutritional and economical possibilities. The nutritional benefit arises from the high levels of polar antioxidants in crude seed oils, as it is known that these are antioxidants offering health benefits. Economical benefit results when seeds traditionally considered as a waste stream become the source of high value vegetable oils. The main identified phenolic compounds in those oils are discussed, as well as the varying levels of total phenolic compounds as determined by the Total Phenol Content (TPC) assay and by HPLC methods. While not all compounds are yet identified, and further study is needed on this subject, it is clear that the phenolic compounds in seed oils contribute to their oxidative stability and to their nutritional importance. The available data show that phenolic compounds are not only abundant in fruits, cereals and vegetables, but seed oils are also good sources of a variety of these antioxidants, in particular phenolic acids. This gives possibilities for the use of otherwise waste streams, such as fruit seeds, as sources of high value oils, with interesting nutritional properties, including essential fatty acids and antioxidants.
Microbial production of rare unsaturated fatty acids and alcohols
Authors: Nagao Toshihiro , Shimada Yuji
Published: November 2010

Aeromonas hydrophila N‐6, isolated from a soil sample, converted vegetable oils to several rare unsaturated fatty acids and alcohols accumulated inside the cells as a wax ester form. A. hydrophila N‐6 effectively decreased fatty acid chain lengths, and converted rapeseed, safflower and linseed oils into 7‐16:1 and 5‐14:1 fatty acids, 7,10‐16:2 and 5,8‐14:2 fatty acids, and 7,10,13‐16:3 fatty acids, respectively. Furthermore, A. hydrophila N‐6 reduced the resulting fatty acids to rare unsaturated fatty alcohols, such as 7‐16:1, 5‐14:1, 9,12‐18:2, 7,10‐16:2, 9,12,15‐18:3 and 7,10,13‐16:3. Such unsaturated fatty acids and alcohols are rarely found in natural oils. Because decreasing fatty acid carbon chain lengths from the carboxyl end and reducing unsaturated fatty acids to unsaturated fatty alcohols in industrially applicable scale are both difficult reactions to accomplish by chemical means, we suggest that A. hydrophila N‐6 may facilitate the introduction of new bioprocesses for producing rare unsaturated fatty acids and alcohols, especially fatty alcohols with more than two double bonds.
Can blood cholesterol levels be too low?
Authors: Stanley John
Published: November 2010

Like glucose, cholesterol is an essential cellular nutrient and like glucose, blood cholesterol levels need to be kept within limits. The deleterious effects of hypercholesterolaemia on the risk of cardiovascular disease are well established and have resulted in the widespread prescription of statins to lower blood cholesterol levels and hence lower the risk of developing the disease. However, the possible deleterious effects of hypocholesterolaemia on mental health are less well studied and while there is enough evidence to cause concern, there is not enough evidence to be sure that these deleterious effects really exist. More research is urgently needed and in particular studies which investigate the possibility that LDL cholesterol and HDL cholesterol have different effects on mental health as they do on cardiovascular health.
Countably Categorical Structures with n‐Degenerate Algebraic Closure
Authors: Vassiliev Evgueni V.
Published: November 2010

We study the class of ω‐categorical structures with n‐degenerate algebraic closure for some n ε ω, which includes ω‐categorical structures with distributive lattice of algebraically closed subsets (see [4]), and in particular those with degenerate (trivial) algebraic closure. We focus on the models of ω‐categorical universal theories, absolutely ubiquitous structures, and ω‐categorical structures generated by an indiscernible set. The assumption of n‐degeneracy implies total categoricity for the first class, stability for the second, and ω‐stability for the third.
On the Consistency of a Positive Theory
Authors: Esser Olivier
Published: November 2010

In positive theories, we have an axiom scheme of comprehension for positive formulas. We study here the “generalized positive” theory GPK∞+. Natural models of this theory are hyperuniverses. The author has shown in [2] that GPK∞+ interprets the Kelley Morse class theory. Here we prove that GPK∞+ + ACWF (ACWF being a form of the axiom of choice allowing to choose elements in well‐founded sets) and the Kelley‐Morse class theory with the axiom of global choice and the axiom “On is ramifiable” are mutually interpretable. This shows that GPK∞+ + ACWF is a “strong” theory since “On is ramifiable” implies the existence of a proper class of inaccessible cardinals.
Boolean Algebras and Distributive Lattices Treated Constructively
Authors: Bell John L.
Published: November 2010

Some aspects of the theory of Boolean algebras and distributive lattices–in particular, the Stone Representation Theorems and the properties of filters and ideals–are analyzed in a constructive setting.
A Real Number Structure that is Effectively Categorical
Authors: Hertling Peter
Published: November 2010

On countable structures computability is usually introduced via numberings. For uncountable structures whose cardinality does not exceed the cardinality of the continuum the same can be done via representations. Which representations are appropriate for doing real number computations? We show that with respect to computable equivalence there is one and only one equivalence class of representations of the real numbers which make the basic operations and the infinitary normed limit operator computable. This characterizes the real numbers in terms of the theory of effective algebras or computable structures, and is reflected by observations made in real number computer arithmetic. Demanding computability of the normed limit operator turns out to be essential: the basic operations without the normed limit operator can be made computable by more than one class of representations. We also give further evidence for the well‐known non‐appropriateness of the representation to some basebby proving that strictly less functions are computable with respect to these representations than with respect to a standard representation of the real numbers. Furthermore we consider basic constructions of representations and the countable substructure consisting of the computable elements of a represented, possibly uncountable structure. For countable structures we compare effectivity with respect to a numbering and effectivity with respect to a representation. Special attention is paid to the countable structure of the computable real numbers.
Distributive Lattices with a Negation Operator
Authors: Celani Sergio Arturo
Published: November 2010

In this note we introduce and study algebras (L, V, Λ, ⌝, 0,1) of type (2, 2,1,1,1) such that (L, V, ⌝, 0,1) is a bounded distributive lattice and ⌝ is an operator that satisfies the condition ⌝ (a V b) = a ⌝ b and ⌝ 0 = 1. We develop the topological duality between these algebras and Priestley spaces with a relation. In addition, we characterize the congruences and the subalgebras of such an algebra. As an application, we will determine the Priestley spaces of quasi‐Stone algebras.
Stability and General Logics
Authors: Hyttinen Tapani
Published: November 2010

In this paper we make an attempt to study classes of models by using general logics. We do not believe that Lww is always the best logic for analyzing a class of models. Let K be a class of models and L a logic. The main assumptions we make about K and C are that K has the L‐amalgamation property and, later in the paper, that K does not omit L‐types. We show that, if modified suitably, most of the results of stability theory hold in this context. The main difference is that existentially closed models of K play the role that arbitrary models play in traditional stability theory. We prove e. g. a structure theorem for the class of existentially closed models of K assuming that K is a trivial superstable class with ndop.
Partition Complete Boolean Algebras and Almost Compact Cardinals
Authors: Jipsen Peter , Rose Henry
Published: November 2010

For an infinite cardinal K a stronger version of K‐distributivity for Boolean algebras, called k‐partition completeness, is defined and investigated (e. g. every K‐Suslin algebra is a K‐partition complete Boolean algebra). It is shown that every k‐partition complete Boolean algebra is K‐weakly representable, and for strongly inaccessible K these concepts coincide. For regular K ≥ u, it is proved that an atomless K‐partition complete Boolean algebra is an updirected union of basic K‐tree algebras. Using K‐partition completeness, the concept of γ‐almost compactness is introduced for γ ≥ K. For strongly inaccessible K we show that K is K‐almost compact iff K is weakly compact, and if K is 2K‐almost compact, then K is measurable. Further K is strongly compact iff it is γ‐almost compact for all γ ≥ K.
Étude constructive de problèmes de topologie pour les réels irrationnels
Authors: Khalouani Mohamed , Labhalla Salah , Lombardi Et Henri
Published: November 2010

We study in a constructive manner some problems of topology related to the set Irr of irrational reals. The constructive approach requires a strong notion of an irrational number; constructively, a real number is irrational if it is clearly different from any rational number. We show that the set Irr is one‐to‐one with the set Dfc of infinite developments in continued fraction (dfc). We define two extensions of Irr, one, called Dfc1, is the set of dfc of rationals and irrationals preserving for each rational one dfc, the other, called Dfc2, is the set of dfc of rationals and irrationals preserving for each rational its two dfc. We introduce six natural distances over Irr wich we denote by dfc0, dfc1, dfc2, d, dmir and dcut. We show that only the four distances dfco, dfc1, d and dmir among the six make Irr a complete metric space. The last distances define in Irr the same topology in a constructive sens. We study further the set Dfc1 in which we show that the irrationals constitute a closed subset. Finally, we make a particular study of the completion Dfc2 of Dfc for the two equivalent metrics dfc2 and dcut.
On MODkP Counting Degrees
Authors: Ozaki Masamitsu , Shinoda Juichi
Published: November 2010

For a prime k, the embeddability of finite lattices are discussed for various kind of the MODkP degrees of recursive sets. In particular, all finite lattices are embeddable into the MODkP Turing degrees, whereas the non distributive lattice M3 is embeddable into the MOD2P many‐one degrees but N5 is not.
Strong Cardinals and Sets of Reals in Lω1(ℝ)
Authors: Schindler Ralf‐Dieter
Published: November 2010

We generalize results of [3] and [1] to hyperprojective sets of reals, viz. to more than finitely many strong cardinals being involved. We show, for example, that if every set of reals in Lω (ℝ) is weakly homogeneously Souslin, then there is an inner model with an inaccessible limit of strong cardinals.
On the Finite Model Property of Intuitionistic Modal Logics over MIPC
Authors: Aoto Takahito , Shirasu Hiroyuki
Published: November 2010

MIPC is a well‐known intuitionistic modal logic of Prior (1957) and Bull (1966). It is shown that every normal intuitionistic modal logicLover MIPC has the finite model property wheneverLis Kripke‐complete and universal.
Sémantique algébrique ďun système logique basé sur un ensemble ordonné fini
Authors: Nour Abir
Published: November 2010

In order to modelize the reasoning of an intelligent agent represented by a poset T, H. Rasiowa introduced logic systems called “Approximation Logics”. In these systems a set of constants constitutes a fundamental tool. In this papers, we consider logic systems called L′T without this kind of constants but limited to the case where T is a finite poset. We prove a weak deduction theorem. We introduce also an algebraic semantics using Hey ting algebra with operators. To prove the completeness theorem of the L′T system with respect to the algebraic semantics, we use the method of H. Rasiowa and R. Sikorski for first order logic. In the propositional case, a corollary allows us to assert that it is decidable to know “if a propositional formula is valid”. We study also certain relations between the L′T logic and the intuitionistic and classical logics.
On a Class of Recursively Enumerable Sets
Authors: Didehvar Farzad
Published: November 2010

We define a class of so‐called ∑(n)‐sets as a natural closure of recursively enumerable sets Wn under the relation “∈” and study its properties.
Approaches to Effective Semi‐Continuity of Real Functions
Authors: Zheng Xizhong , Brattka Vasco , Weihrauch Klaus
Published: November 2010

For semi‐continuous real functions we study different computability concepts defined via computability of epigraphs and hypographs. We call a real function f lower semi‐computable of type one, if its open hypograph hypo(f) is recursively enumerably open in dom(f) × ℝ; we call f lower semi‐computable of type two, if its closed epigraph Epi(f) is recursively enumerably closed in dom(f) × ℝ; we call f lower semi‐computable of type three, if Epi(f) is recursively closed in dom(f) × ℝ. We show that type one and type two semi‐computability are independent and that type three semi‐computability plus effectively uniform continuity implies computability, which is false for type one and type two instead of type three. We show also that the integral of a type three semi‐computable real function on a computable interval is not necessarily computable.
Can You Add Power‐Sets to Martin‐Lof's Intuitionistic Set Theory?
Authors: Maietti Maria Emilia , Valentini Silvio
Published: November 2010

In this paper we analyze an extension of Martin‐Löf s intensional set theory by means of a set contructor P such that the elements of P(S) are the subsets of the set S. Since it seems natural to require some kind of extensionality on the equality among subsets, it turns out that such an extension cannot be constructive. In fact we will prove that this extension is classic, that is “(A V ⌝ A) true holds for any proposition A.
About Segment Complexity of Turing Reductions
Authors: Bulitko Valeriy K.
Published: November 2010

We apply complexity concepts to define a new sort of sub‐Turing reducibilities ≤ 𝔷 make the degree hierarchy thinner and to obtain some new specifications of the well known jump inversion theorem of Friedberg. We show that this theorem doesn't hold when ≤ T is replaced with ≤ 𝔷, where 𝔷 is any countable subset of the class 𝔷 of all total increasing functions f : ℕ → ℕ.
1H and 13C assignments of two new macrocyclic lactones isolated from Streptomyces sp. 211726 and revised assignments of Azalomycins F3a, F4aand F5a
Authors: Yuan Ganjun , Lin Haipeng , Wang Cheng , Hong Kui , Liu Yue , Li Jia
Published: November 2010

Azalomycin F4a 2‐ethylpentyl ester (1) and Azalomycin F5a 2‐ethylpentyl ester (2), two new macrocyclic lactones, along with three known compounds of Azalomycins F3a (3), F4a (4) and F5a (5), were identified from metabolites of Streptomyces sp. 211726 isolated from mangrove rhizosphere soil. The complete 1H and 13C assignments of these compounds were achieved by using 1H, 13C, DEPT, HSQC, 1H‐1H COSY and HMBC spectra, and the relative stereochemistry of 5 was first elucidated on the basis of proton–proton coupling constants, NOESY and IR spectra. Moreover, some errors in the 1H and 13C assignments published of 3, 4 and 5 were found and revised. 1 and 2 were active against Candida albicans, and exhibited moderate cyctotoxicity against HCT‐116 cell line. Copyright © 2010 John Wiley & Sons, Ltd.
Electrical and rheological percolation in poly(vinylidene fluoride)/multi‐walled carbon nanotube nanocomposites
Authors: Martins Johnny N , Bassani Taís S , Barra Guilherme MO , Oliveira Ricardo VB
Published: November 2010

Nanocomposites of poly(vinylidene fluoride) (PVDF) and multi‐walled carbon nanotubes (MWCNTs) were prepared through melt blending in a batch mixer (torque rheometer equipped with a mixing chamber). The morphology, rheological behavior and electrical conductivity were investigated through transmission electron microscopy, dynamic oscillatory rheometry and the two‐probe method. The nanocomposite with 0.5 wt% MWCNT content presented a uniform dispersion through the PVDF matrix, whereas that with 1 wt% started to present a percolated network. For the nanocomposites with 2 and 5 wt% MWCNTs the formation of this nanotube network was clearly evident. The electrical percolation threshold at room temperature found for this system was about 1.2 wt% MWCNTs. The rheological percolation threshold fitted from viscosity was about 1 wt%, while the threshold fitted from storage modulus was 0.9 wt%. Thus fewer nanotubes are needed to approach the rheological percolation threshold than the electrical percolation threshold. Copyright © 2010 Society of Chemical Industry
Synthesis of quaternized ammonium iodide‐containing conjugated polymer electrolytes and their application in dye‐sensitized solar cells
Authors: Lee Rong‐Ho , Liu Jene‐Ku , Ho Jhu‐Heng , Chang Jhih‐Wei , Liu Bo‐Tau , Wang Hsing‐Ju , Jeng Ru‐Jong
Published: November 2010

A series of conjugated polymer electrolytes (CPEs) comprising fluorene/carbazole or thiophene/carbazole backbones with quaternized ammonium iodide groups were synthesized and used in polymer solution and polymer gel electrolytes in dye‐sensitized solar cells (DSSCs). The photovoltaic (PV) performances became markedly poorer with increasing CPE content for the DSSCs based on polymer solution electrolytes. However, the PV performances were not significantly affected with increasing CPE content for the DSSCs fabricated from poly(ethylene oxide) (PEO)/CPE blend‐based gel‐type electrolytes. Moreover, higher PV efficiencies and stabilities were obtained for the DSSCs based on PEO/CPE blend gel electrolytes as compared to the DSSCs based on PEO gel electrolyte. The electrochemical impedance and PV properties of the DSSCs based on polymer solution electrolytes and on polymer gel electrolytes were determined as a function of the CPE concentration. Copyright © 2010 Society of Chemical Industry
Service Learning and Integrated, Collaborative Project Management
Authors: Dixon Gene
Published: November 2010

This article describes the development of an undergraduate course on project management that incorporates experiential learning and service learning as the primary course learning methodology to instill in students the Project Management Institute's nine Knowledge Areas. The discussed instructional method is a dynamic and participative pedagogy. The project management course content is traditionally structured around system needs and analysis identification, functional requirements analysis, project timelines, network analysis, and project progress metrics. Introduction of service-learning projects and experiential learning pedagogies provides a pragmatic approach for applying project management concepts. This article compares and contrasts the first three offerings of this course and provides lessons learned that may be helpful to others wishing to embrace project management realism in their course work. The purpose of this article is to encourage a hands-on method for learning the nine Knowledge Areas in the undergraduate classroom.
Screening for symptoms of depression and anxiety in adolescents and young adults with cystic fibrosis
Authors: Modi Avani C. , Driscoll Kimberly A. , Montag‐Leifling Karen , Acton James D.
Published: November 2010

Background

Although studies have assessed symptoms of depression and anxiety in individuals with cystic fibrosis (CF), few have been conducted since the advent of new medical treatments (e.g., nebulized antibiotics, ThAIRpy Vest). Study objectives were to: (1) document symptoms of depression and anxiety for adolescents and young adults with CF and compare with normative values, (2) examine the associations among depressive/anxiety symptoms and gender, age, lung function, and body mass index, and (3) determine the relations between adolescent and caregiver symptoms of depression and anxiety.

Methods

Patients and caregivers completed the Hospital Anxiety and Depression Scale (HADS) anytime (e.g., beginning or end) during routine CF clinic appointments.

Results

Participants included 59 adolescents/young adults with CF (Mage = 15.8 years, 54% female, 98% Caucasian, MFEV1% predicted = 84.6) and caregivers of 40 adolescents. Although symptom scores were in the normative range for patients with CF (MDepression = 2.27 and MAnxiety = 5.59), 3% and 32% exhibited clinically elevated symptoms of depression and anxiety, respectively. Symptoms of depression and anxiety were significantly associated with age (r = 0.28, 0.36). Symptoms of depression and anxiety were also positively correlated (r = 0.48). Females endorsed higher anxiety symptoms than males. While adolescent and caregiver anxiety scores were not related, higher caregiver depressive symptoms were associated with older patient age and worse lung function.

Conclusions

Data from the current study suggest low levels of depressive symptoms and substantial levels of anxiety symptoms in adolescents and young adults with CF. Consistent with prior literature, depressive symptoms appear higher in older patients and are significantly associated with anxiety symptoms. Caregiver symptomology appears to be more affected by an adolescent's health status, suggesting a need to screen caregivers when health begins to decline. Pediatr. Pulmonol. 2011; 46:153–159. © 2011 Wiley‐Liss, Inc.
Evaluation of interrupter resistance in methacholine challenge testing in children
Authors: Koopman Marije , Brackel Hein J.L. , Vaessen‐Verberne Anja A.P.H. , Hop Wim C. , van der Ent Cornelis K. ,   on behalf of the COMBO‐R Research Group
Published: November 2010

Bronchial hyperresponsiveness (BHR) is a key feature of asthma and is assessed using bronchial provocation tests. The primary outcome in such tests (a 20% decrease in forced expiratory volume in 1 sec (FEV1)) is difficult to measure in young patients. This study evaluated the sensitivity and specificity of the interrupter resistance (Rint) technique, which does not require active patient participation, by comparing it to the primary outcome measure.

Methacholine challenge tests were performed in children with a history of moderate asthma and BHR. Mean and individual changes in Rint and FEV1 were studied. A receiver operating characteristic (ROC) curve was used to describe sensitivity and specificity of Rint.

Seventy‐three children (median age: 9.2 years; range: 6.3–13.4 years) participated. There was a significant (P < 0.01) increase in mean Rint with increasing methacholine doses. However, individual changes of Rint showed large fluctuations. There was great overlap in change of Rint between children who did and did not reach the FEV1 endpoint. A ROC curve showed an area under the curve of 0.65.

Because of low sensitivity and specificity, the use of Rint to diagnose BHR in individual patients seems limited. Pediatr Pulmonol. 2011; 46:266–271. © 2011 Wiley‐Liss, Inc.
Prescribing hormone replacement therapy: the role of occupational stress
Authors: Chen Ruey‐Jien , Lu Luo
Published: November 2010

This study investigates whether physicians' levels of occupational stress may influence the likelihood of their prescribing hormone replacement therapy (HRT). One hundred and one physicians answered a cross‐sectional, mailed, self‐administered survey that measured occupational stress using Occupational Stress Indicator 2. Questions concerning HRT—including the possibility of recommending HRT to treat menopausal syndrome—were also asked. We found the likelihood of prescribing HRT for menopausal syndrome positively correlates with ‘coping’ (p < 0.01) and ‘other indications’ (p < 0.001). The likelihood of prescribing is also greater when the patient is a younger menopausal woman (p < 0.0001) and if the physician is more experienced (p < 0.05). Multiple regression analysis reveals that the ‘coping’ scale (p < 0.05) is the most significant factor, whereas ‘seeking support’ is the significant subscale (p < 0.0001). Our results indicate that ‘seeking support’ from the ‘coping’ scale is the most important factor that influences the prescribing of HRT. Copyright © 2010 John Wiley & Sons, Ltd.
Stretching the limits of visual attention: the case of action video games
Authors: Hubert‐Wallander Bjorn , Green C. Shawn , Bavelier Daphne
Published: November 2010

Visual attention is the set of mechanisms by which relevant visual information is selected while irrelevant information is suppressed, thus allowing the observer to function in a world made up of nearly infinite visual information. Recently, those who habitually play video games have been documented to outperform novices in a variety of visual attentional capabilities, including attention in space, in time, and to objects. Training studies have established similar improvements in groups of nongamers given experience playing these video games. Critically, not all video games seem to have such a beneficial effect on attention; it seems that fast‐paced, embodied visuo‐motor tasks that require divided attention (tasks commonly found in popular action games like Halo) have the greatest effect. At the core of these action video game‐induced improvements appears to be a remarkable enhancement in the ability to efficiently deploy endogenous attention. The implications of such an enhancement are relevant to a variety of real‐world applications, such as work force training, rehabilitation of clinical populations, and improvement of traditional educational approaches. WIREs Cogni Sci 2011 2 222–230 DOI: 10.1002/wcs.116

This article is categorized under:

Psychology > Learning
Quantitative analysis of yeast internal architecture using soft X‐ray tomography
Authors: Uchida Maho , Sun Yidi , McDermott Gerry , Knoechel Christian , Le Gros Mark A. , Parkinson Dilworth , Drubin David G. , Larabell Carolyn A.
Published: November 2010

We used soft X‐ray tomography (SXT)—a high‐resolution, quantitative imaging technique—to measure cell size and organelle volumes in yeasts. Cell size is a key factor in initiating cell division in yeasts, whereas the number and volume of the organelles have a profound impact on the function and viability of a cell. Consequently, determining these cell parameters is fundamentally important in understanding yeast biology. SXT is well suited to this type of analysis. Specimens are imaged in a near‐native state, and relatively large numbers of cells can be readily analysed. In this study, we characterized haploid and diploid strains of Saccharomyces cerevisiae at each of the key stages in the cell cycle and determined the relationships that exist cellular and organelle volumes. We then compared these results with SXT data obtained from Schizosaccharomyces pombe, the three main phenotypes displayed by the opportunistic yeast pathogen Candida albicans and from a coff1‐22 mutant strain of S. cerevisiae. This comparison revealed that volumetric ratios were invariant, irrespective of yeast strain, ploidy or morphology, leading to the conclusion these volumetric ratios are common in all yeasts. Copyright © 2010 John Wiley & Sons, Ltd.
Über die Fehlerabschätzung des Adams schen Verfahrens zur Integration gewöhnlicher Differentialgleichungen 1. Ordnung
Authors: Fricke Arnold
Published: November 2010

Die von Tollmien für den Annäherungsgrad n=3 gegebene Fehlerabschätzung für die extrapolative und interpolative Form des Adamsschen Verfahrens zur numerischen Integration gewöhnlicher Differentialgleichungen 1. Ordnung wird auf einen beliebigen Annäherungsgrad verallgemeinert und verschärft. Die erhaltenen Fehlerschranken werden mit den von v. Mises und G. Schulz angegebenen verglichen und an Beispielen erläutert.
Zur hydrodynamischen Schmiertheorie des Zapfenlagers
Authors: Weber C.
Published: November 2010

“Strebt nach der besten Lösung”

Ausgehend von der Grundgleichung und vom Variationsproblem des endlichen Zapfenlagers wird die optimale Näherung der Druckfunktion gefunden für den Fall, daß die Näherung als Produkt einer Funktion von x (in Laufrichtung) und einer Funktion von z (in Achsrichtung des Zapfens) gewählt wird. Für die Funktion von z finden wir eine geschlossene Lösung, für die Funktion von x eine Differentialgleichung. Für diese wird an Hand eines Beispiels eine Lösungsmethode dargelegt. Für das Beispiel wird die Lagerkraft und ihre Richtung berechnet.
Zur elastisch‐plastischen Deformation des rotierenden Kreisrings
Authors: Gamer U.
Published: November 2010

Untersucht wird der ebene Spannungszustand sowie die Deformation eines rotierenden Kreisrings aus elastisch‐plastischem Material mit linearer Verfestigung unter Zugrundelegung der Tresca schen Fließbedingung und der zugehörigen Fließregel.
Mathematische Deutung des ‘Flat Facet Models’ zur Bildverarbeitung
Authors: Werner H.
Published: November 2010

In dieser Note wird ein Verfahren für die Verarbeitung von gerasterten Bilddaten mit Hilfe des unten genauer definierten Facettenmodells zur Verschärfung der Konturen mathematisch gedeutet. Dazu nehmen wir an, daß die Grauwertverteilung über einem äguidistanten Raster T aus einer über dem gesamten Definitionsintervall gegebenen, etwa zweimal stetig differenzierbaren Funktion x gewonnen worden ist. Bei Anwendung des Bildverbesserungsprozesses entwickeln sich Sprungstellen jeweils zwischen zwei Rasterpunkten, die nahe bei Wendepunkten liegen, in denen der Betrag der ersten Ableitung, also |x|, ein relatives Maximum besitzt. Die Werte der Verteilungsfunktion streben bei der Iteration gegen eine auf jeder Facette (d. h. den Rasterpunkten zwischen den Sprungstellen) konstante Funktion X, deren Wert auf der Facette gegeben wird durch x(t) mit einem t, in dem |x| näherungsweise sein Minimum auf dieser Facette annimmt.
Heat and Mass Transfer in the Vapour Gas Region of a Gas‐Loaded Heat Pipe
Authors: Shukla K. N. , Sankara Rao K.
Published: November 2010

A numerical analysis is made of the unsteady two‐dimensional heat and mass transfer in the vapour gas region of a gas‐loaded heat pipe. The parabolic mass, momentum, energy and species conservation equations for a symmetrical heat pipe are solved and the quantitative behaviour of the start up transient in the vapour gas region is presented.
A New Approach for Investigating the Thermal Instability of a Fluid Layer
Authors: Li Nian , Murphy J. O. , Steiner J. M.
Published: November 2010

Eine neue direkte Methode zum Lösen verschiedener Eigenwertprobleme wird vorgestellt. Sie kommen in der linearen Theorie der thermischen Konvektion in einer Fluidschicht vor, die von unten erwärmt ist, in Abwesenheit oder Gegenwart von Rotation und/oder eines magnetischen Feldes. Notwendige und hinreichende Bedingungen für die Existenz nichttrivialer Lösungen verschiedener Eigenwertprobleme werden für den allgemeinen Fall hergeleitet, und danach wird die Methode vorteilhaft zum Studium der thermischen Instabilität einer Schicht angewandt, begrenzt durch alle beliebigen Randtypen. Die Methode ist streng, einfach anzuwenden, anwendbar auf alle Randtypen: frei, fest, gemischt, vollkommen leitend oder nichtleitend und außerdem ist der Gebrauch der üblichen mathematischen Softwarepakete leicht. Einige ungelöste Konvektionsprobleme mit Rotation und gleichzeitig vorhandenem Magnetfeld werden das erste Mal unter Benutzung dieser Methode in Angriff genommen.
Transient Wave Propagation in an Infinite Voigt‐Viscoelastic Layer Due to Concentrated Moving Loads
Authors: Ishikawa K. , Hirashima M.
Published: November 2010

Die Wirkung einer unendlichen viskoelastischen Schicht auf die Ausbreitung von Ausgleichsvorgängen kann analytisch bestimmt werden. Das Ziel dieser Arbeit ist die Entwicklung von Eigenfunktionen für die Ausbreitung von Ausgleichsvorgängen, und die Darstellung einer Untersuchung des Problems unter Benutzung dieser Funktionen. Diese Berechnung von Eigenfunktionen beruht darauf, daß die Bewegungsgleichungen in der zweidimensionalen Viskoelastizität vom Voigt‐Typ, dargestellt als simultane partielle Differentialgleichungen, direkt unter Rand‐und Anfangsbedingungen gelöst werden, anstelle der Verwendung der Potentialtheorie und der Integraltransformationstechnik für die Reduzierung der Zeitvariablen. Die Lösungen für Verschiebungen können durch Benutzung der Fouriertransformierten und der Eigenfunktionen für die Separation der Variablen durch die Stokessche Methode erhalten werden. Die numerischen Resultate zeigen die Ausbreitung der Ausgleichsvorgänge für Spannungen, hervorgerufen durch zwei gleiche und normal sowie entgegengesetzt konzentrierte Kräfte, welche plötzlich auf die freie Oberflächen wirken, und die sich dann geradlinig mit konstanter Geschwindigkeit entlang der Oberfläche bewegen.
A Subspace Study on Conjugate Gradient Algorithms
Authors: Yuan Y.‐X. , Stoer J.
Published: November 2010

In dieser Arbeit analysieren wir Techniken zur Berechnung einer Suchrichtung durch die Minimierung des quadratischen Näherungsmodells in dem vom aktuellen Gradienten und der vorangegangenen Suchrichtung aufgespannten zweidimensionalen Unterraum. Die klassischen konjugierten Gradientenmethoden sind dabei nur Spezialfälle mit quadratischer Zielfunktion und exakten Kantensuchverfahren. Basierend auf unseren Analysen für den Fall nicht exakter Kantensuchverfahren konstruieren wir neue Algorithmen vom Typ der Verfahren der konjugierten Richtungen.
On the Robustness of a Multiple Semi‐coarsened Grid Method
Authors: Oosterlee C. W. , Wesseling P.
Published: November 2010

The robustness of a non‐standard multigrid method called Multiple Semi‐coarsened Grids (MSG) is investigated. The smoother is a damped point‐Jacobi relaxation method. Three different coarse grid correction strategies are implemented and compared. Robustness is investigated by solving the rotated anisotropic diffusion equation and the convection diffusion equation.
Interaction of a Crack with a Circular Inclusion in a Thermally Stressed Material
Authors: Herrmann K. P. , Wang R.
Published: November 2010

The influence of a thermally mismatched inclusion on the stress intensity factors at the tips of an interacting crack is investigated. The analytical expressions for the stress intensity factors KIand KIIof a crack submitted to the stresses due to the thermal misfit of a constrained inclusion are given by using an appropriate dislocation density function. The stress intensity factors vary with the size, position and the thermal misfit strain of the inclusion. The characteristics of this crack‐inclusion interaction problem are analyzed and discussed.
Three‐Dimensional Flow of a Power‐Law Fluid Due to a Stretching Flat Surface
Authors: Gorla R. S. R. , Dakappagari V. , Pop Ioan
Published: November 2010

Exakte Ähnlichkeitslösungen für die stationäre dreidimensionale nicht‐newtonsche Strömung eines Ostwald‐de Waele Fluids, hervorgerufen durch Dehnung einer flachen Grenzschicht, werden dargestellt. Die Bewegungsgleichungen werden auf zwei gewöhnliche DGL reduziert, die numerisch für verschiedene Werte des Ostwald‐de Waele Index n und des Dehnwertes e gelöst werden.
Convectively Unstable Wave Packets in the Blasius Boundary Layer
Authors: Brevdo L.
Published: November 2010

Basierend auf der formalen Lösung des linearen Anfangs‐Randwert‐Stabilitätsproblems für die Blasiussche Grenzschichtströmung, BREVDO [8], werden die instabilen Wellenpakete in dieser Strömung, d. h. die Pakete von Tollmien‐Schlichting‐Wellen. Für eine breite Menge von Reynoldszahlen R mit Hilfe von Chebyshev‐Kollokationsmethoden numerisch untersucht. Wir zeigen. daß die Blasiussche Grenzschichtströmung absolut stabil, aber konvektiv instabil für Rc <R < 104 ist, wobei R, die kritische Reynoldszahl bezeichnet. Die Abhängigkeit der Eigenschaften der konvektiv instabilen Wellenpakete, wie etwa: die Ausbreitungsgeschwindigkeit, die Anfachungsrate, räumliche Struktur usw. von der Reynoldszahl R wird untersucht. Insbesondere wird mit Hilfe der eN‐Methode gezeigt, daß die Transition zur Turbulenz in dieser Strömung für die Reynoldszahlen beschleunigt werden kann, die viel größer sind als die Reynoldszahl Rm, bei der die Anfachungsrate des Wellenpakets γigihr Maximum hat Für eine feste Reynoldszahl R wird die Abhängigkeit der lokalen, räumlichen Struktur von der Strahlgeschwindigkeit untersucht. Unsere Ergebnisse stimmen gut mit den verfügbaren Messungen überein.
The Structural Dynamic Formulation of Non‐Rotating and Rotating Systems Using Real and Complex Normal Modes
Authors: Niedbal N. , Klusowski E.
Published: November 2010

Experimentelle Modalanalyse‐Verfahren beschreiben das strukturdynamische Verhalten elastischer Strukturen teilweise mit komplexen Eigenschwingungen. Zur Steifigkeit nichtproportionale Dämpfungsverteilung wird allgemein als Ursache dieses Verhaltens angenommen. Andere Untersuchungen zeigen, daß komplexe Eigenschwingungen auch aus Unzulänglichkeiten im Versuch resultieren können. Die Extraktion reeller Eigenschwingungen aus komplexen Eigenschwingungskenngrößen wird deshalb auf rotierende Systeme als eine praktisch interessante Anwendung erweitert. Das Beispiel zeigt, daß diese Berechnung der reellen Eigenschwingungen eine Rück transformation in die Ausgangsgleichungen darstellt.
Analyse des Kriechverhaltens dünner Schalen und Platten unter zyklischen Belastungen
Authors: Moratschkowski O. , Naumenko K.
Published: November 2010

Nach einer kurzgefaßten Darstellung der materialabhängigen Zustandsgleichungen des zyklischen Kriechens wird in der Arbeit ein spezielles numerisches Verfahren zur Analyse des Kriechverhaltens dünner Schalen und Platten bei mehrachsiger Belastung (Überlagerung von statischem Druck und zyklisch veränderlicher, kurzperiodischer Belastung) vorgestellt. Die Möglichkeiten der theoretischen Modellierung und des Lösungsverfahrens werden anhand von Beispielen illustriert.
Definition of Physically Consistent Damping Laws with Fractional Derivatives
Authors: Beyer H. , Kempfle S.
Published: November 2010

Betrachtet wird die verallgemeinerte Schwingungsgleichung E: (D2 + aDq + b) x(t) = f(t); q ≠ (0, 2). Es wird gezeigt, daß es für q ε 1 und x, f ε L2C(R) beliebig viele Möglichkeiten der Definition von E gibt, entsprechend der Wahl der Äste von (iε)q zur Definition charakteristischer Funktionen p(ε) = (i)2 + a(iε)q + b. Dabei muß p lediglich meßbar sein. Neben allgemeinen Bedingungen für die Eindeutigkeit und die Kausalität von Lösungen werden auch für Anwendungen wichtige Ergebnisse erzielt: So folgt die Eindeutigkeit bereits, wenn p stetig ist und keine reellen Nullstellen hat. Wird ferner p auf den Hauptast beschränkt, so gibt es kausale Lösungen genau dann, wenn a,b > 0. Als Beispiel wird eine allgemeine analytische Lösung der kausalen Impulsantwort gegeben und diskutiert.
Shooting Methods for Two‐Point BVPs with Partially Separated Endconditions
Authors: Hermann M. , Kaiser D.
Published: November 2010

Mittels eines neuen verallgemeinerten Brent‐ Verfahrens für Systeme nichtlinearer algebraischer Gleichungen wird die “stabilized march technique” auf nichtlineare Zwei‐Punkt‐Randwertprobleme ausgedehnt. Die sich ergebenden Algorithmen können in ökonomischer Weise zur Lösung von Systemen nichtlinearer gewöhnlicher Differentialgleichungen erster Ordnung mil partiell separierten nichtlinearen Randbedingungen verwendet werden. Es werden numerische Ergebnisse angegeben, die die nichtlineare "stabilized march method" mil der Standard‐Mehrfach‐Schießmethode vergleichen.
Gronwall Type Inequalities
Authors: Popenda J.
Published: November 2010

In Abschnitt I werden verschiedene Formen derjenigen Integralungleichung betrachtet, die von vielen Autoren als Gronwall‐Ungleichung beschrieben wird, und es wird versucht, eine allgemeine Definition zu geben. In Abschnitt II wird eine algebraische Version gegeben, von der gezeigt wird, daß sich daraus viele der bekannten Gronwall‐Ungleichungen ableiten lassen.
Conjugate Free Convection from a Horizontal Surface in a Porous Medium
Authors: Lesnic D. , Ingham D B. , Pop I.
Published: November 2010

In dieser Arbeit wird eine detaillierte Untersuchung der konjugiert freien Konvektion von einer horizontalen flachen Platte endlicher Länge mit Grenzschicht‐Approximation gegeben, die in ein poröses Medium eingebettet ist. Das Problem wird auf ein Paar gekoppelter, parabolischer, partieller Differentialgleichungen für die Temperatur‐ und die Stromfunktion reduziert. Die vollen numerischen und asymptotischen Lösungen werden für einen großen x‐Bereich erhalten (x Koordinate längs der Platte). Die Resultate für die Temperatur‐ und Geschwindigkeitsprofile an der Platte und im konvektiven Fluid werden vorgestellt. Ein Vergleich zwischen der Finite‐Differenzen‐Lösung und der kleinen und großen Lösungsdarstellung durch Reihen illustriert, daß die volle numerische Lösung genau ist.