Regulating ride-sharing in the peer economy

This magazine article examines the challenges of digital disruption and the way the struggle for legitimacy is playing out in mainstream and social media. Using ride-sharing as a case study, our team at the QUT Digital media research centre seeks to develop the tools policy-makers need to make evidence-based policy decisions in response to digital disruption.

Paper 1: The disruptive forces of the sharing economy

Overview: - The sharing economy unlocks a previously unused value of goods and labour, and causes disruption in established industries. - The pattern of disruption is similar regardless of the industry that's impacted. While the initial phases of disruption are transformational for many (e.g. lost jobs), often the industries end up stronger than before they were before the disruption. - Due to different in setting, upholding and enforcing standards, it is hard to assess the regulatory trade-offs. Safety, labour relations and social fairness are important factors to consider across the industry.

Narrative, Memory and the Crisis of Mimesis: the Case of Adam Elsheimer and Giordano Bruno

The triangular space between memory, narrative and pictorial representation is the terrain on which this article is developed. Taking the art of memory developed by Giordano Bruno (1548 – 1600) and the art of painting subtly revolutionised by Adam Elsheimer (1578 – 1610) as test-cases, it is shown how both subvert the norms of mimesis and narration prevalent throughout the Renaissance, how disrupted memory creates “incoherent” narratives, and how perspective and the notion of “place” are questioned in a corollary way. Two paintings by Elsheimer are analysed and shown to include, in spite of their supposed “realism”, numerous incoherencies, aporias and strange elements – often overlooked. Thus, they do not conform to two of the basic rules governing both the classical art of memory and the humanist art of painting: well-defined places and the exhaustive translatability of words into images (and vice-versa). In the work of Bruno, both his philosophical claims and the literary devices he uses are analysed as hints for a similar (and contemporaneous) undermining of conventions about the transparency and immediacy of representation.

Generalized Burgers equations and Euler–Painlevé transcendents. III

It was proposed earlier [P. L. Sachdev, K. R. C. Nair, and V. G. Tikekar, J. Math. Phys. 27, 1506 (1986); P. L. Sachdev and K. R. C. Nair, ibid. 28, 977 (1987)] that the Euler–Painlevé equations  y(d2y/dη2)+a(dy/dη)2 +f(η)y(dy/dη)+g(η)y2+b(dy/dη) +c=0 represent generalized Burgers equations (GBE’s) in the same way as Painlevé equations represent the Korteweg–de Vries type of equations. The earlier studies were carried out in the context of GBE’s with damping and those with spherical and cylindrical symmetry. In the present paper, GBE’s with variable coefficients of viscosity and those with inhomogeneous terms are considered for their possible connection to Euler–Painlevé equations. It is found that the Euler–Painlevé equation, which represents the GBE ut+uβux=(δ/2)g(t)uxx, g(t)=(1+t)n, β>0, has solutions, which either decay or oscillate at η=±∞, only when −1

Studies in nonlinear optical materials: structure of di-2-menthyl 2-(N,N'-dimethyl-2-imidazolidinylidene)malonate monohydrate

C28H48N2Oa.H2 O, Mr=494.7, orthorhombic,P2~2~2~, a = 7.634 (2), b = 11.370 (2), c=34. 167 (4) A, V = 2966 (2) A 3, Z = 4, D m = 1.095,D x -- 1. 108 g cm -3, Mo Kct, 2 -- 0.7107 ,/k, ~ =0.43 cm -~, F(000) = 1088.0, T= 293 K, R = 0.061 for 1578 significant reflections. The second-harmonicgeneration (SHG) efficiency of this compound is negligible (1/100th of the urea standard). The observed low second-order nonlinear response has been attributed to the unfavourable packing of the molecules in the crystal lattice.

Ultimate Strength of RC Wall Panels with Openings

Test results of 12 reinforced concrete (RC) wall panels with openings are presented. The panels have been subjected to in-plane vertical loads applied at an eccentricity to represent possible accidental eccentricity that occurs in practice due to constructional imperfections. The 12 specimens consist of two identical groups of six panels each. One group of panels is tested in one-way in-plane action (i.e., supported at top and bottom edges against lateral displacement). The second group of panels is tested in two-way in-plane action (i.e., supported on all the four edges against lateral displacement). Openings in the panels represent typical door and window openings. Cracking loads, ultimate loads, crack patterns, and lateral deflections of the panels are studied. Empirical methods have been developed for the prediction of ultimate load. Also, lateral deflections, cracking loads, and ultimate loads of identical loads tested under one-way and two-way action are compared.

Onttojen puiden lahopuukovakuoriaiset — kolmen pyydystyypin vertailu

Vanhat ja ontot puut ovat tärkeä elinympäristö monelle lahopuusta riippuvaiselle eliölajille. Onttoihin puihin on erikoistunut suuri määrä myös vaarantuneita ja harvinaisia hyönteislajeja, jotka elävät puun onkalon seinämillä tai onkalon pohjalle kerääntyvässä orgaanisessa aineksessa, ns. mulmissa. Tutkimuksen tavoitteena oli selvittää, mikä kolmesta pyydystyypistä (ikkuna-, vuoka- ja kuoppapyydys) soveltuu parhaiten onttojen puiden lahopuukovakuoriaisten pyyntiin. Lisäksi tavoitteena oli kartoittaa hyönteisnäytteiden ensimmäiseen laboratoriokäsittelyyn vaadittua aikaa. Tutkimuksessa oli mukana vanhoja rungostaan onttoutuneita lehmuksia, tammia ja vaahteroita pääkaupunkiseudun puisto- ja kartanoalueilta. Puiden onkaloiden sisään aseteltiin ikkuna-, vuoka- ja kuoppapyydyksiä, kaksi kutakin tyyppiä ja ne tyhjennettiin kolmen viikon välein touko-heinäkuussa 2006. Pyydyksiä oli siis yhteensä 90 per pyyntijakso. Kun näytteistä eroteltiin halutut hyönteislahkot (mukaanlukien kovakuoriaiset) niiden käsittelyyn käytetty aika kirjattiin ylös. Aineistosta tunnistettiin yhteensä 3825 kovakuoriaisyksilöä ja 212 lajia, joista lahopuusta riippuvaisia oli yhteensä 3398 yksilöä ja 121 lajia. Ikkunapyydyksissä esiintyi yhteensä 1639 yksilöä ja 140 lajia, vuokapyydyksissä 1506 yksilöä ja 134 lajia, kuoppapyydyksissä 680 yksilöä ja 111 lajia. Näytteiden käsittelyaikojen keskiarvot olivat 48,3 minuuttia ikkunapyydykselle, 65,5 minuuttia vuokapyydykselle ja 34,1 kuoppapyydykselle. Lajistokoostumuksen huomioiva ?-diversiteetti erosi huomattavasti pyydysten välillä, se oli 36,5 % ikkuna- ja vuokapyydysten välillä, 13,1 % ikkuna- ja kuoppapyydysten välillä ja 14,2 % vuoka- ja kuoppapyydysten välillä. Ikkuna- ja vuokapyydysten välillä ei havaittu tilastollisesti merkitsevää eroa saproksyylilajien (p<0,05), -yksilöiden (p<0,05) tai käsittelyaikojen (p<0,05) keskiarvoissa. Ikkuna- ja vuokapyydyksillä saatiin keskimäärin selvästi enemmän saproksyylilajeja ja –yksilöitä kuoppapyydykseen verrattuna. Kuoppapyydyksellä saatiin kokonaisyksilömäärään verrattuna suhteellisesti vähemmän saproksyylejä (59 %) kuin ikkuna- (69 %) ja vuokapyydyksillä (71 %). Ikkunapyydykset olivat tehokkain pyydystyyppi vertailtaessa pyydysten keräämää saproksyyliyksilömäärää suhteessa aineiston käsittelyn vaatimaan aikaan. Tehokkuus (yksilöä minuutissa) ikkunapyydykselle oli 0,74, vuokapyydykselle 0,43 ja kuoppapyydykselle 0,21. Ikkunapyydyksiä ei ole aikaisemmin käytetty puun onkalon sisällä hyönteisiä pyydettäessä vaan ne ovat aikaisemmissa tutkimuksissa roikkuneet onkalon ulkopuolella. Ikkunapyydykset kuitenkin toimivat erinomaisesti myös onkaloiden sisällä. Ikkuna- sekä vuokapyydys toimivatkin selkeästi paremmin lahopuukovakuoriaisten pyynnissä verrattuna kuoppapyydykseen, jonka poisjättäminen olisi kuitenkin tuottanut huomattavasti lajiköyhemmän aineiston. Mahdollisimman monimuotoisen onttojen puiden lahopuukovakuoriaislajiston keräämiseksi tulisi käyttää ikkuna- tai vuokapyydyksiä yhdessä kuoppapyydysten kanssa.

Coordination-Driven Self-Assembly of M3L2 Trigonal Cages from Preorganized Metalloligands Incorporating Octahedral Metal Centers and Fluorescent Detection of Nitroaromatics

The design and preparation of novel M3L2 trigonal cages via the coordination-driven self-assembly of preorganized metalloligands containing octahedral aluminum(III), gallium(III), or ruthenium(II) centers is described. When tritopic or dinuclear linear metalloligands and appropriate complementary subunits are employed, M3L2 trigonal-bipyramidal and trigonal-prismatic cages are self-assembled under mild conditions. These three-dimensional cages were characterized with multinuclear NMR spectroscopy (H-1 and P-31) and high-resolution electrospray ionization mass spectrometry. The structure of one such trigonal-prismatic cage, self-assembled from an arene ruthenium metalloligand, was confirmed via single-crystal X-ray crystallography. The fluorescent nature of these prisms, due to the presence of their electron-rich ethynyl functionalities, prompted photophysical studies, which revealed that electron-deficient nitroaromatics are effective quenchers of the cages' emission. Excited-state charge transfer from the prisms to the nitroaromatic substrates can be used as the basis for the development of selective and discriminatory turn-off fluorescent sensors for nitroaromatics.

An Approach Toward Homocalystegines and Silyl-homocalystegines. Acid-Mediated Migrations of Acetates in Seven-Membered Ring Systems

A short access to homocalystegine analogues silylated at C7 is described. The synthesis involves the desymmetrization of a (phenyldimethylsilyl)methylcycloheptatriene using osmium-mediated dihydroxylation, followed by the diol protection and a cycloaddition involving the remaining diene moiety and an acylnitroso reagent. Additions of the osmium and acylnitroso reagents were shown, through X-ray diffraction studies of the resulting major isomers, to occur anti and syn, respectively, relative to the SiCH2 substituent. N-O bond cleavage on the resulting cycloadduct then produces the aminopolyol having a silylmethyl substituent. Oxidation of the C-Si bond also afforded an access to unusual amino-heptitols having five contiguous stereogenic centers. In the course of this work, we finally observed a unusual rearrangement taking place on cycloheptanone 18 substituted by two acetyl groups and a neighboring Boc-protected amine. A profound reorganization of the substituents on the seven-membered ring effectively took place under acidic conditions (TFA) leading to the thermodynamically more stable homocalystegine-type compound., DFT calculations of the conformational energy of isomeric silyl homocalystegines indicated that the product observed upon the acid-mediated rearrangement was the most stable of a series of analogues with various distributions of substituents along the seven-membered ring backbone. A tentative mechanism is proposed to rationalize the acetate migrations and inversions of the stereochemistry at various stereocenters.

Exact complex-wave reconstruction in digital holography

We address the problem of exact complex-wave reconstruction in digital holography. We show that, by confining the object-wave modulation to one quadrant of the frequency domain, and by maintaining a reference-wave intensity higher than that of the object, one can achieve exact complex-wave reconstruction in the absence of noise. A feature of the proposed technique is that the zero-order artifact, which is commonly encountered in hologram reconstruction, can be completely suppressed in the absence of noise. The technique is noniterative and nonlinear. We also establish a connection between the reconstruction technique and homomorphic signal processing, which enables an interpretation of the technique from the perspective of deconvolution. Another key contribution of this paper is a direct link between the reconstruction technique and the two-dimensional Hilbert transform formalism proposed by Hahn. We show that this connection leads to explicit Hilbert transform relations between the magnitude and phase of the complex wave encoded in the hologram. We also provide results on simulated as well as experimental data to validate the accuracy of the reconstruction technique. (C) 2011 Optical Society of America

Role of Hetero-Halogen (F center dot center dot center dot X, X = Cl, Br, and I) or Homo-Halogen (X center dot center dot center dot X, X = F, Cl, Br, and I) Interactions in Substituted Benzanilides

A series of halogen-substituted benzanilides have been synthesized and characterized, and crystallization studies directed toward generation of polymorphs have been performed to delineate the importance of interactions involving halogens. The effect of halogen substitution on the molecular conformation and supramolecular packing has been investigated. The N-H center dot center dot center dot O H-bond is a key structure-directing element acting in conjunction with C-H center dot center dot center dot O and C-H center dot center dot center dot pi interactions. In addition, it is of importance to note that organic fluorine prefers Type I F center dot center dot center dot F contacts, whereas Cl, Br, and I prefer Type II contacts. Hetero-halogen center dot center dot center dot halogen interactions on the other hand are predominately of Type II geometry, and this is due to the greater polarizability of the electron density associated with the heavier halogens. It is of importance to evaluate the contributing role of these interactions in crystal structure packing and the co-operativity associated with such interactions in the solid state.

Dynamics of water at the interface of a small protein, enterotoxin

Fully atomistic molecular dynamics simulations have been carried out to investigate the correlation of biological activity with dynamics of water molecules in an aqueous protein solution of the toxic domain of enterotoxin (PDB ID: 1ETN). This is a small protein of 13 amino acid residues. Our study of this water soluble protein clearly reveals that water dynamics slows down in the hydration layer. Despite this general slowing down, water molecules in the vicinity of the second beta turn of this protein exhibit faster dynamics than those near other regions of the protein. Since this beta turn is believed to play a critical role in the receptor binding of this protein, the faster dynamics of water near the beta turn m ay have biological significance. The collective orientational dynamics of the water molecules in the protein solution exhibits a characteristic long time component of 27 ps, which agrees well with dielectric relaxation experiments.

Oxygen displacement in a 107Ag17+ ion irradiated Bi2Sr2CaCu2O8 single crystal

We have studied the magnetic field (H∥c) dependent rf dissipation (Hrf∥a) in an as-grown Bi2Sr2CaCu2O8 single crystal prior to and after irradiation with 250 MeV 107Ag17+ ions. In a comparison of the responses from the as-grown crystal with an air-annealed crystal, features due to oxygen deficient regions acting as weak links in the former are identified. These features disappear immediately after irradiation of the as-grown crystal. We attribute such behavior to the displacement of oxygen from columnar tracks to deficient regions thus eliminating the weak links. Losses from the same irradiated as-grown crystal stored at 300 K for 60 days show that the features similar but not identical to those observed in the pristine state have reappeared implying that the displaced oxygen is in a metastable configuration in the deficient regions and hence is mobile due to thermal effects even at 300 K.