374 resultados para weak ties


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We analyze the regional distribution of different categories of creative individuals in Germany. Generally, the share of creative people is higher in cities as compared to the rural area The freelancing artists are a kind of exception in this respect; they constitute a relatively high share of the population in some rural area A high share of creative people in a region can be explained by a high level of public provisions and a high share of foreign born population, which can be regarded as an indicator of the “openness” in the local milieu. Good employment opportunities have only a relatively weak impact. Regions with a high share of creatives tend to have an above average level of new business formation, a high level of innovation and a relatively high share of employees in high-tech industries.

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Magnesium minerals are important for the understanding of the concept of geosequestration. One method of studying the hydrated hydroxy magnesium carbonate minerals is through vibrational spectroscopy. A combination of Raman and infrared spectroscopy has been used to study the mineral hydromagnesite. An intense band is observed at 1121 cm-1 attributed CO32- ν1 symmetric stretching mode. A series of infrared bands at 1387, 1413, 1474 cm-1 are assigned to the CO32- ν3 antisymmetric stretching modes. The CO32- ν3 antisymmetric stretching vibrations are extremely weak in the Raman spectrum and are observed at 1404, 1451, 1490 and 1520 cm-1. A series of Raman bands at 708, 716, 728, 758 cm-1 are assigned to the CO32- ν2 in-plane bending mode. The Raman spectrum in the OH stretching region is characterised by bands at 3416, 3516 and 3447 cm-1. In the infrared spectrum a broad band is found at 2940 cm-1 assigned to water stretching vibrations. Infrared bands at 3430, 3446, 3511, 2648 and 3685 cm-1 are attributed to MgOH stretching modes.

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The progesterone receptor (PR) is a candidate gene for the development of endometriosis, a complex disease with strong hormonal features, common in women of reproductive age. We typed the 306 base pair Alu insertion (AluIns) polymorphism in intron G of PR in 101 individuals, estimated linkage disequilibrium (LD) between five single-nucleotide polymorphisms (SNPs) across the PR locus in 980 Australian triads (endometriosis case and two parents) and used transmission disequilibrium testing (TDT) for association with endometriosis. The five SNPs showed strong pairwise LD, and the AluIns was highly correlated with proximal SNPs rs1042839 (Δ2 = 0.877, D9 = 1.00, P < 0.0001) and rs500760 (Δ2 = 0.438, D9 = 0.942, P < 0.0001). TDT showed weak evidence of allelic association between endometriosis and rs500760 (P = 0.027) but not in the expected direction. We identified a common susceptibility haplotype GGGCA across the five SNPs (P = 0.0167) in the whole sample, but likelihood ratio testing of haplotype transmission and non-transmission of the AluIns and flanking SNPs showed no significant pattern. Further, analysis of our results pooled with those from two previous studies suggested that neither the T2 allele of the AluIns nor the T1/T2 genotype was associated with endometriosis.

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Surrogacy has produced some positive outcomes creating an opportunity for otherwise childless couples to live their dream of parenthood. However it has also been problematic, particularly where the surrogate mother fails to relinquish a child born as a result of the surrogacy arrangement. This article examines whether a surrogate mother, who is genetically related to the child she delivers, is less likely to relinquish the child than one who has no genetic ties. An examination of empirical evidence provides support for this argument. Legislation and case law in three jurisdictions, Australia, the United States and the United Kingdom, is examined to determine which, if any, of these jurisdictions take into account the existence, or otherwise, of a genetic link between the surrogate mother and the child she bears. The article concludes that surrogacy legislation should, subject to exceptional circumstances, encourage surrogacy arrangements where the child and the surrogate are not genetically related.

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The hexagonal resonator characteristics of an individual ZnO-nanonail’s head were investigated via spatially resolved cathodoluminescence (CL) at room temperature. The positions of most of distinct CL peaks in visible range were well matched to those of whispering gallery modes (WGMs) of a hexagonal dielectric cavity when we took birefringence and dispersion of refractive indices into account. The broad and weak peaks for TE polarization in long wavelength range were consistent with refractive-index values below the threshold for total internal inflection. CL peaks that were not matched to WGMs were identified as either triangular quasi-WGM or Fabry–Pérot resonance modes.

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Purpose – The purpose of this paper is to explore whether internal audit’s reporting relationship with the audit committee and the client’s business risk environment impact external auditors’ reliance on the work of internal audit. Design/methodology/approach – An experiment is conducted using a 2 £ 2 between-subjects design where we manipulate the above two factors at strong and weak levels. Participants are 66 audit partners, managers and seniors, all experienced with clients having internal audit functions. Findings – The results indicate that both factors affect external auditors’ reliance on work already undertaken by internal audit and their use of internal auditors (IA) as assistants. The results also indicate that external auditors are more likely to use internal audit for control evaluation tasks than for substantive tests of balances. The study does not find any significant interaction effects between the two factors. Originality/value – No prior studies have examined the influence of reporting relationship and client business risk on external auditors’ reliance decisions in the current governance environment. Further, the paper examines the impact of these factors on reliance on work already undertaken by internal audit and on using IA as assistants, with respect to both control evaluation work and substantive testing of balances.

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In the structure of title compound [Rb2(C7H4NO2)2(H2O)2]n the centrosymmetric cyclic dimeric repeating unit comprises two irregular RbO4 complex centres bridged by the carboxylate groups of the 5-nitrosalicylate ligands. The coordination about each Rb is completed by a monodentate water molecule and a phenolic O donor which gives a bridging extension [Rb-O range 3.116(7)-3.135(5)A]. The two-dimensional polymeric structure is stabilized by intermolecular water O-H...O(carboxyl) hydrogen bonds and weak inter-ring pi--pi interactions [minimum ring centroid separation, 3.620(4)A].

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Despite various approaches, the production of biodegradable plastics such as polyhydroxybutyrate (PHB) in transgenic plants has met with limited success due largely to low expression levels. Even in the few instances where high levels of protein expression have been reported, the transgenic plants have been stunted indicating PHB is phytotoxic (Poirier 2002). This PhD describes the application of a novel virus-based gene expression technology, termed InPAct („In Plant Activation.), for the production of PHB in tobacco and sugarcane. InPAct is based on the rolling circle replication mechanism by which circular ssDNA viruses replicate and provides a system for controlled, high-level gene expression. Based on these features, InPAct was thought to represent an ideal system to enable the controlled, high-level expression of the three phb genes (phbA, phbB and phbC) required for PHB production in sugarcane at a preferred stage of plant growth. A Tobacco yellow dwarf virus (TbYDV)-based InPAct-phbA vector, as well as linear vectors constitutively expressing phbB and phbC were constructed and different combinations were used to transform tobacco leaf discs. A total of four, eight, three and three phenotypically normal tobacco lines were generated from discs transformed with InPAct-phbA, InPAct-phbA + p1300-TaBV P-phbB/phbC- 35S T, p1300-35S P-phbA-NOS T + p1300-TaBV P-phbB/phbC-35S T and InPAct-GUS, respectively. To determine whether the InPAct cassette could be activated in the presence of the TbYDV Rep, leaf samples from the eight InPActphbA + p1300-TaBV P-phbB/phbC-35S T plants were agroinfiltrated with p1300- TbYDV-Rep/RepA. Three days later, successful activation was indicated by the detection of episomes using both PCR and Southern analysis. Leaf discs from the eight InPAct-phbA + p1300-TaBV P-phbB/phbC-35S T transgenic plant lines were agroinfiltrated with p1300-TbYDV-Rep/RepA and leaf tissue was collected ten days post-infiltration and examined for the presence of PHB granules. Confocal microscopy and TEM revealed the presence of typical PHB granules in five of the eight lines, thus demonstrating the functionality of InPActbased PHB production in tobacco. However, analysis of leaf extracts by HPLC failed to detect the presence of PHB suggesting only very low level expression levels. Subsequent molecular analysis of three lines revealed low levels of correctly processed mRNA from the catalase intron contained within the InPAct cassette and also the presence of cryptic splice sites within the intron. In an attempt to increase expression levels, new InPAct-phb cassettes were generated in which the castorbean catalase intron was replaced with a synthetic intron (syntron). Further, in an attempt to both increase and better control Rep/RepA-mediated activation of InPAct cassettes, Rep/RepA expression was placed under the control of a stably integrated alc switch. Leaf discs from a transgenic tobacco line (Alc ML) containing 35S P-AlcR-AlcA P-Rep/RepA were supertransformed with InPAct-phbAsyn or InPAct-GUSsyn using Agrobacterium and three plants (lines) were regenerated for each construct. Analysis of the RNA processing of the InPAct-phbAsyn cassette revealed highly efficient and correct splicing of the syntron, thus supporting its inclusion within the InPAct system. To determine the efficiency of the alc switch to activate InPAct, leaf material from the three Alc ML + InPAct-phbAsyn lines was either agroinfiltrated with 35S P-Rep/RepA or treated with ethanol. Unexpectedly, episomes were detected not only in the infiltrated and ethanol treated samples, but also in non-treated samples. Subsequent analysis of transgenic Alc ML + InPAct-GUS lines, confirmed that the alc switch was leaky in tissue culture. Although this was shown to be reversible once plants were removed from the tissue culture environment, it made the regeneration of Alc ML + InPAct-phbsyn plant lines extremely difficult, due to unintentional Rep expression and therefore high levels of phb expression and phytotoxic PHB production. Two Alc ML + InPAct-phbAsyn + p1300-TaBV P-phbB/phbC-35S T transgenic lines were able to be regenerated, and these were acclimatised, alcohol-treated and analysed. Although episome formation was detected as late as 21 days post activation, no PHB was detected in the leaves of any plants using either microscopy or HPLC, suggesting the presence of a corrupt InPAct-phbA cassette in both lines. The final component of this thesis involved the application of both the alc switch and the InPAct systems to sugarcane in an attempt to produce PHB. Initial experiments using transgenic Alc ML + InPAct-GUS lines indicated that the alc system was not functional in sugarcane under the conditions tested. The functionality of the InPAct system, independent of the alc gene switch, was subsequently examined by bombarding the 35S Rep/RepA cassette into leaf and immature leaf whorl cells derived from InPAct-GUS transgenic sugarcane plants. No GUS expression was observed in leaf tissue, whereas weak and irregular GUS expression was observed in immature leaf whorl tissue derived from two InPAct- GUS lines and two InPAct-GUS + 35S P-AlcR-AlcA P-GUS lines. The most plausible reason to explain the inconsistent and low levels of GUS expression in leaf whorls is a combination of low numbers of sugarcane cells in the DNA replication-conducive S-phase and the irregular and random nature of sugarcane cells bombarded with Rep/RepA. This study details the first report to develop a TbYDV-based InPAct system under control of the alc switch to produce PHB in tobacco and sugarcane. Despite the inability to detect quantifiable levels of PHB levels in either tobacco or sugarcane, the findings of this study should nevertheless assist in the further development of both the InPAct system and the alc system, particularly for sugarcane and ultimately lead to an ethanol-inducible InPAct gene expression system for the production of bioplastics and other proteins of commercial value in plants.

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Usability in HCI (Human-Computer Interaction) is normally understood as the simplicity and clarity with which the interaction with a computer program or a web site is designed. Identity management systems need to provide adequate usability and should have a simple and intuitive interface. The system should not only be designed to satisfy service provider requirements but it has to consider user requirements, otherwise it will lead to inconvenience and poor usability for users when managing their identities. With poor usability and a poor user interface with regard to security, it is highly likely that the system will have poor security. The rapid growth in the number of online services leads to an increasing number of different digital identities each user needs to manage. As a result, many people feel overloaded with credentials, which in turn negatively impacts their ability to manage them securely. Passwords are perhaps the most common type of credential used today. To avoid the tedious task of remembering difficult passwords, users often behave less securely by using low entropy and weak passwords. Weak passwords and bad password habits represent security threats to online services. Some solutions have been developed to eliminate the need for users to create and manage passwords. A typical solution is based on generating one-time passwords, i.e. passwords for single session or transaction usage. Unfortunately, most of these solutions do not satisfy scalability and/or usability requirements, or they are simply insecure. In this thesis, the security and usability aspects of contemporary methods for authentication based on one-time passwords (OTP) are examined and analyzed. In addition, more scalable solutions that provide a good user experience while at the same time preserving strong security are proposed.

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A healthy human would be expected to show periodic blinks, making a brief closure of the eyelids. Most blinks are spontaneous, occurring regularly with no external stimulus. However a reflex blink can occur in response to external stimuli such as a bright light, a sudden loud noise, or an object approaching toward the eyes. A voluntary or forced blink is another type of blink in which the person deliberately closes the eyes and the lower eyelid raises to meet the upper eyelid. A complete blink, in which the upper eyelid touches the lower eyelid, contributes to the health of ocular surface by providing a fresh layer of tears as well as maintaining optical integrity by providing a smooth tear film over the cornea. The rate of blinking and its completeness vary depending on the task undertaken during blink assessment, the direction of gaze, the emotional state of the subjects and the method under which the blink was measured. It is also well known that wearing contact lenses (both rigid and soft lenses) can induce significant changes in blink rate and completeness. It is been established that efficient blinking plays an important role in ocular surface health during contact lens wear and for improving contact lens performance and comfort. Inefficient blinking during contact lens wear may be related to a low blink rate or incomplete blinking and can often be a reason for dry eye symptoms or ocular surface staining. It has previously been shown that upward gaze can affect blink rate, causing it to become faster. In the first experiment, it was decided to expand on previous studies in this area by examining the effect of various gaze directions (i.e. upward gaze, primary gaze, downward gaze and lateral gaze) as well as head angle (recumbent position) on normal subjects’ blink rate and completeness through the use of filming with a high-speed camera. The results of this experiment showed that as the open palpebral aperture (and exposed ocular surface area) increased from downward gaze to upward gaze, the number of blinks significantly increased (p<0.04). Also, the size of closed palpebral aperture significantly increased from downward gaze to upward gaze (p<0.005). A weak positive correlation (R² = 0.18) between the blink rate and ocular surface area was found in this study. Also, it was found that the subjects showed 81% complete blinks, 19% incomplete blinks and 2% of twitch blinks in primary gaze, consistent with previous studies. The difference in the percentage of incomplete blinks between upward gaze and downward gaze was significant (p<0.004), showing more incomplete blinks in upward gaze. The findings of this experiment suggest that while blink rate becomes slower in downward gaze, the completeness of blinking is typically better, thereby potentially reducing the risk of tear instability. On the other hand, in upward gaze while the completeness of blinking becomes worse, this is potentially offset by increased blink frequency. In addition, blink rate and completeness were not affected by lateral gaze or head angle, possibly because these conditions have similar size of the open palpebral aperture compared with primary gaze. In the second experiment, an investigation into the changes in blink rate and completeness was carried out in primary gaze and downward gaze with soft and rigid contact lenses in unadapted wearers. Not surprisingly, rigid lens wear caused a significant increase in the blink rate in both primary (p<0.001) and downward gaze (p<0.02). After fitting rigid contact lenses, the closed palpebral aperture (blink completeness) did not show any changes but the open palpebral aperture showed a significant narrowing (p<0.04). This might occur from the subjects’ attempt to avoid interaction between the upper eyelid and the edge of the lens to minimize discomfort. After applying topical anaesthetic eye drops in the eye fitted with rigid lenses, the increased blink rate dropped to values similar to that before lens insertion and the open palpebral aperture returned to baseline values, suggesting that corneal and/or lid margin sensitivity was mediating the increased blink rate and narrowed palpebral aperture. We also investigated the changes in the blink rate and completeness with soft contact lenses including a soft sphere, double slab-off toric design and periballast toric design. Soft contact lenses did not cause any significant changes in the blink rate, closed palpebral aperture, open palpebral aperture and the percentage of incomplete blinks in either primary gaze or downward gaze. After applying anaesthetic eye drops, the blink rate reduced in both primary gaze and downward gaze, however this difference was not statistically significant. The size of the closed palpebral aperture and open palpebral aperture did not show any significant changes after applying anaesthetic eye drops. However it should be noted that the effects of rigid and soft contact lenses that we observed in these studies were only the immediate reaction to contact lenses and in the longer term, it is likely that these responses will vary as the eye adapts to the presence of the lenses.

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Higher-order spectral (bispectral and trispectral) analyses of numerical solutions of the Duffing equation with a cubic stiffness are used to isolate the coupling between the triads and quartets, respectively, of nonlinearly interacting Fourier components of the system. The Duffing oscillator follows a period-doubling intermittency catastrophic route to chaos. For period-doubled limit cycles, higher-order spectra indicate that both quadratic and cubic nonlinear interactions are important to the dynamics. However, when the Duffing oscillator becomes chaotic, global behavior of the cubic nonlinearity becomes dominant and quadratic nonlinear interactions are weak, while cubic interactions remain strong. As the nonlinearity of the system is increased, the number of excited Fourier components increases, eventually leading to broad-band power spectra for chaos. The corresponding higher-order spectra indicate that although some individual nonlinear interactions weaken as nonlinearity increases, the number of nonlinearly interacting Fourier modes increases. Trispectra indicate that the cubic interactions gradually evolve from encompassing a few quartets of Fourier components for period-1 motion to encompassing many quartets for chaos. For chaos, all the components within the energetic part of the power spectrum are cubically (but not quadratically) coupled to each other.

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The crystal structures of the proton-transfer compounds of 3,5-dinitrosalicylic acid (DNSA) with a series of aniline-type Lewis bases [aniline, 2-hydroxyaniline, 2-methoxyaniline, 3-methoxyaniline, 4-fluoroaniline, 4-chloroaniline and 2-aminoaniline] have been determined and their hydrogen-bonding systems analysed. All are anhydrous 1:1 salts: [(C6H8N)+(C7H3N2O7)-], (1), [(C6H8NO)+(C7H3N2O7)-], (2), [(C7H10NO)+(C7H3N2O7)-], (3), [(C7H10NO)+(C7H3N2O7)-], (4), [(C6H7FN)+(C7H3N2O7)-], (5), [(C6H7ClN)+(C7H3N2O7)-], (6), and [(C6H9N2)+(C7H3N2O7)-], (7) respectively. Crystals of 1 and 6 are triclinic, space group P-1 while the remainder are monoclinic with space group either P21/n (2, 4, 5 and 7) or P21 (3). Unit cell dimensions and contents are: for 1, a = 7.2027(17), b = 7.5699(17), c = 12.9615(16) Å, α = 84.464(14), β = 86.387(15), γ = 75.580(14)o, Z = 2; for 2, a = 7.407(3), b = 6.987(3), c = 27.653(11) Å, β = 94.906(7)o, Z = 4; for 3, a = 8.2816(18), b = 23.151(6), c = 3.9338(10), β = 95.255(19)o, Z = 2; for 4, a = 11.209(2), b = 8.7858(19), c = 15.171(3) Å, β = 93.717(4)o, Z = 4; for 5, a = 26.377(3), b = 10.1602(12), c = 5.1384(10) Å, β = 91.996(13)o, Z = 4; for 6, a = 11.217(3), b = 14.156(5), c = 4.860(3) Å, α = 99.10(4), β = 96.99(4), γ = 76.35(2)o, Z = 2; for 7, a = 12.830(4), b = 8.145(3), c = 14.302(4) Å, β = 102.631(6)o, Z = 4. In all compounds at least one primary linear intermolecular N+-H…O(carboxyl) hydrogen-bonding interaction is present which, together with secondary hydrogen bonding results in the formation of mostly two-dimensional network structures, exceptions being with compounds 4 and 5 (one-dimensional) and compound 6 (three-dimensional). In only two cases [compounds 1 and 4], are weak cation-anion or cation-cation π-π interactions found while weak aromatic C-H…O interactions are insignificant. The study shows that all compounds fit the previously formulated classification scheme for primary and secondary interactive modes for proton-transfer compounds of 3,5-dinitrosalicylic acid but there are some unusual variants.

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In the structure of the title compound [Rb4(C9H6NO4)4(H~2~O)6]n, the asymmetric unit comprises four rubidium complex cations, two of which have an RbO7 coordination polyhedron with a monocapped distorted octahedral stereochemistry and two of which have a distorted RbO6 octahedral coordination. The bonding about both the seven-coordinate centres is similar, comprising one monodentate water molecule together with three bridging water molecules and three carboxylate O-atom donors, two of which are bridging. The environments about the six-coordinate cations are also similar, comprising a monodentate nitro O-atom donor, a bridging water molecule and four bridging carboxylate O-atom donors [overall Rb-O range, 2.849(2)-3.190(2)A]. The coordination leads to a two-dimensional polymeric structure extending parallel to (001), which is stabilized by interlayer water O-H...O hydrogen-bonding associations to water, carboxyl and nitro O-atom acceptors, together with weak inter-ring pi--pi interactions [minimum ring centroid separation = 3.5319(19)A].

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This paper formulates a node-based smoothed conforming point interpolation method (NS-CPIM) for solid mechanics. In the proposed NS-CPIM, the higher order conforming PIM shape functions (CPIM) have been constructed to produce a continuous and piecewise quadratic displacement field over the whole problem domain, whereby the smoothed strain field was obtained through smoothing operation over each smoothing domain associated with domain nodes. The smoothed Galerkin weak form was then developed to create the discretized system equations. Numerical studies have demonstrated the following good properties: NS-CPIM (1) can pass both standard and quadratic patch test; (2) provides an upper bound of strain energy; (3) avoid the volumetric locking; (4) provides the higher accuracy than those in the node-based smoothed schemes of the original PIMs.