160,818 research outputs found
The Ho-Zhao problem
No full textGiven a poset P, the set Γ(P) of all Scott closed sets ordered by inclusion forms a complete lattice. A subcategory C of Posd (the category of posets and Scott-continuous maps) is said to be Γ-faithful if for any posets P and Q in C, Γ(P) ∼= Γ(Q) implies P ∼= Q. It is known that the category of all continuous dcpos and the category of bounded complete dcpos are Γ-faithful, while Posd is not. Ho & Zhao (2009) asked whether the category DCPO of dcpos is Γ-faithful. In this paper, we answer this question in the negative by exhibiting a counterexample. To achieve this, we introduce a new subcategory of dcpos which is Γ-faithful. This subcategory subsumes all currently known Γ-faithful subcategories. With this new concept in mind, we construct the desired counterexample which relies heavily on Johnstone’s famous dcpo which is not sober in its Scott topology
Study of Ho-doped Bi2Te3 topological insulator thin films
No full textThis publication arises from research funded by the John Fell Oxford University Press (OUP) Research Fund and the Research Complex at Harwell is acknowledged for their hospitality. This work was supported by a DARPA MESO project (No. N66001-11-1-4105). S.E.H. was supported by the VPGE (Stanford University). L.C.M. and A.A.B. acknowledge partial financial support from EPSRC (UK) through a Doctoral Training Award. Diamond Light Source is acknowledged for beamtime on I10 (proposal SI10207).Breaking time-reversal symmetry through magnetic doping of topological insulators has been identified as a key strategy for unlocking exotic physical states. Here, we report the growth of Bi2Te3 thin films doped with the highest magnetic moment element Ho. Diffraction studies demonstrate high quality films for up to 21% Ho incorporation. Superconducting quantum interference device magnetometry reveals paramagnetism down to 2 K with an effective magnetic moment of ∼5 μB/Ho. Angle-resolved photoemission spectroscopy shows that the topological surface state remains intact with Ho doping, consistent with the material's paramagnetic state. The large saturation moment achieved makes these films useful for incorporation into heterostructures, whereby magnetic order can be introduced via interfacial coupling.Peer reviewe
HO-1 expression in macrophages.
No full textRepresentative sections (400x magnifications) of rat prostate MatLyLu TINT double stained for CD68+ (brow) and HO-1+ (red) cells (A), or double stained for CD163+ (brown) and HO-1+ (red) cells (B). Most cells stained both red and blown suggesting that most HO-1+ cells are macrophages, and in particular of the M2-type (CD163+).</p
The 1961 Kampong Bukit Ho Swee fire and the making of modern Singapore
No full textBy 1970, Singapore’s urban landscape was dominated by high-rise blocks of planned public housing built by the People’s Action Party government, signifying the establishment of a high modernist nation-state. A decade earlier, the margins of the City had been dominated by kampongs, home to semi-autonomous communities of low-income Chinese families which freely built, and rebuilt, unauthorised wooden houses. This change was not merely one of housing but belied a more fundamental realignment of state-society relations in the 1960s. Relocated in Housing and Development Board flats, urban kampong families were progressively integrated into the social fabric of the emergent nation-state. This study examines the pivotal role of an event, the great Kampong Bukit Ho Swee fire of 1961, in bringing about this transformation. The redevelopment of the fire site in the aftermath of the calamity brought to completion the British colonial regime’s ‘emergency’ programmes of resettling urban kampong dwellers in planned accommodation, in particular, of building emergency public housing on the sites of major fires in the 1950s. The PAP’s far greater political resolve, and the timing of and state of emergency occasioned by the scale of the 1961 disaster, enabled the government to rehouse the Bukit Ho Swee fire victims in emergency housing in record time. This in turn provided the HDB with a strategic platform for clearing other kampongs and for transforming their residents into model citizens of the nation-state. The 1961 fire’s symbolic usefulness extended into the 1980s and beyond, in sanctioning the PAP’s new housing redevelopment schemes. The official account of the inferno has also become politically useful for the government of today for disciplining a new generation of Singaporeans against taking the nation’s progress for granted. Against these exalted claims of the fire’s role in the Singapore Story, this study also examines the degree of actual change and continuity in the social and economic lives of the people of Bukit Ho Swee after the inferno. In some crucial ways, the residents continued to occupy a marginal place in society while pondering, too, over the unresolved question of the cause of the fire. These continuities of everyday life reflect the ambivalence with which the citizenry regarded the high modernist state in contemporary Singapore
HMOX1 gene promoter alleles and high HO-1 levels are associated with severe malaria in Gambian children.
No full textHeme oxygenase 1 (HO-1) is an essential enzyme induced by heme and multiple stimuli associated with critical illness. In humans, polymorphisms in the HMOX1 gene promoter may influence the magnitude of HO-1 expression. In many diseases including murine malaria, HO-1 induction produces protective anti-inflammatory effects, but observations from patients suggest these may be limited to a narrow range of HO-1 induction, prompting us to investigate the role of HO-1 in malaria infection. In 307 Gambian children with either severe or uncomplicated P. falciparum malaria, we characterized the associations of HMOX1 promoter polymorphisms, HMOX1 mRNA inducibility, HO-1 protein levels in leucocytes (flow cytometry), and plasma (ELISA) with disease severity. The (GT)(n) repeat polymorphism in the HMOX1 promoter was associated with HMOX1 mRNA expression in white blood cells in vitro, and with severe disease and death, while high HO-1 levels were associated with severe disease. Neutrophils were the main HO-1-expressing cells in peripheral blood, and HMOX1 mRNA expression was upregulated by heme-moieties of lysed erythrocytes. We provide mechanistic evidence that induction of HMOX1 expression in neutrophils potentiates the respiratory burst, and propose this may be part of the causal pathway explaining the association between short (GT)(n) repeats and increased disease severity in malaria and other critical illnesses. Our findings suggest a genetic predisposition to higher levels of HO-1 is associated with severe illness, and enhances the neutrophil burst leading to oxidative damage of endothelial cells. These add important information to the discussion about possible therapeutic manipulation of HO-1 in critically ill patients
Increased expression of heme oxygenase (HO)-1 in alveolar spaces and HO-2 in alveolar walls of smokers
No full textIt has been suggested that oxidative stress protein heme oxygenase (HO)-1 plays a role in chronic airway diseases including chronic obstructive pulmonary disease (COPD). The inducible isoform HO-1 and the constitutive HO-2 catalyze the same reaction. Their distribution in situ was studied in lungs of 10 nonsmoking subjects, 6 healthy smokers, and 10 smokers with COPD. Paraffin-embedded sections of surgical lung specimens were immunostained with antibodies against HO-1 and HO-2. HO-1 immunoreactivity was observed mainly in alveolar macrophages. HO-1-positive macrophages were increased in smokers with COPD (median: 36%) as compared with nonsmoking subjects (13%; p < 0.02), whereas no differences were observed between patients with COPD and healthy smokers (34%). HO-2 had a more widespread distribution in cells of the alveolar wall, in adventitia of pulmonary arteries and bronchioles, and in vascular smooth muscle. Lower percentages of alveolar macrophages exhibited positive staining for HO-2 without significant differences between the three groups. HO-2(+) cells in the alveolar wall were increased in smokers with (15/mm) and without COPD (12/mm) as compared with nonsmokers (8/mm, p < 0.01). In conclusion, inducible HO-1 and constitutive HO-2 are detectable in human lung tissue and their expression is increased in smokers, suggesting that oxidative stress due to cigarette smoke may increase lung cells expressing HO-1 and HO-2
Ethusina alcocki Ng & Ho 2003, new species
No full text<i>Ethusina alcocki</i>, new species <p>(Figs. 4, 5)</p> <p> <i>Ethusina investigatoris</i> – Chen & Xu, 1991: 60, Fig. 9 (not <i>E. investigatoris</i> Alcock, 1896)</p> <p> <i>Material examined. –</i> Holotype - female, 8.2 by 9.8 mm (NTOU), Station CP 32, 22 01.7’N, 120 11.1’E, 910-1129 m, coll. TAIWAN 2000, R. V. “Fishery Researcher 1”, 30 Jul.2000.</p> <p> <i>Etymology. –</i> This species is named after A. Alcock, whose contributions to Indian carcinology have not been rivalled.</p> <p> <i> <i>Remarks. –</i> Ethusina alcocki</i> , new species, is rather close to <i>E. investigatoris</i> Alcock, 1896, but three characters argue against its inclusion there. In <i>E. investigatoris</i>, the median frontal teeth are more prominent, with the inner margin more convex, the supraorbital margin is relatively narrower, and the dactylus of the P2 and P3 is about one-third shorter and relatively broader (cf. Alcock, 1896: 295; Alcock & MacGilchrist, 1905: Pl. 72 fig. 3). Chen (1986b: 135, Fig. 14) referred a male specimen from China to <i>E. investigatoris</i>, and this seems to be correct. Chen & Xu (1991: 60, Fig. 9) subsequently reported <i>E. investigatoris</i> from the South China Sea, but the external orbital spine of the male specimen she figured is relatively shorter with the median frontal teeth subequal in length (rather than with the outer tooth longer). Recently, through the courtesy of H.-L. Chen, the first author had an opportuinity to examine a second specimen from the South China Sea which had been identified as “ <i>E. investigatoris</i> ” and is almost identical to that described by Chen & Xu (1991). We have no doubt that this specimen is conspecific with what is here identified as <i>E. alcocki</i>. Unfortunately, the original specimens described in Chen (1986) and Chen & Xu (1991) could not be located for direct comparisons as the IOCAS is currently moving its catalogued collections to a new building and the material is not available for study (H.-L. Chen, pers. comm., September 2002).</p> <p> Alcock (1896: 285) described <i>E. investigatoris</i> from the Laccadive Sea and Bay of Bengal, in the Indian Ocean, noting that the elongated external orbital spine is “needlelike” but “falls considerably short of the tips of the rather long acute frontal spines” (see also Alcock & MacGilchrist, 1905: Pl. 72 fig. 3), and felt that it was very close to <i>E. gracilipes</i> (Miers, 1886). <i>Ethusina alcocki</i>, however, differs from <i>E. gracilipes</i> in having the external orbital spine relatively longer, reaching to the tip of the frontal spines (not falling short of it), and the inner median teeth are also lower and are not spiniform.</p>Published as part of <i>Ng, Peter K. L. & Ho, P. - H., 2003, On The Deep-Water Dorippid Crabs Of The Genus Ethusina Smith, 1884 (Crustacea: Decapoda: Brachyura) From Taiwan, pp. 71-85 in Raffles Bulletin of Zoology 51 (1)</i> on pages 74-75, DOI: <a href="http://zenodo.org/record/4619337">10.5281/zenodo.4619337</a>
Booktalk at library : Prof Ho Lok-sang
No full textIn this booktalk, Prof. Ho Lok-sang talked over the inspiration and writing of his recent works. Ho, L. S. (2013). The psychology and economics of happiness: Love, life and positive living. Routledge. Ho, L. S. (2011). Human spirituality and happiness : a tribute to life, the source of inspirations, the source of hope, the source of joy. AuthorHouse
Synthesis of spherical nanoparticles of Cu2L2O5 (L = Ho, Er) from W/O microemulsions
No full textNanoparticles of Cu2L2O, (L = Ho, Er) (15-25 nm in size) were synthesised by the intermediate use of W/O microemulsions. In this process the aqueous cores of water/cetyltrimethylammonium bromide/n-octane/1-butanol microemulsions were used as microreactors for the precipitation of Cu2Ho2(CO3)(4)(OH)(2) (25-30 nm) and Cu2Er2(CO3)(4)(OH)(2) (10-40 nm) as precursors. These mixed salts were separated and further decomposed to the corresponding mixed oxides at 900 degrees C for 16 h. All solids were characterised by scanning and transmission electron microscopy, IR, XRPD, ICP-OES, TCA, XPS measurements and elemental analyses
Cooling rates of neutron stars and the young neutron star in the Cassiopeia A supernova remnant
No full textWe explore the thermal state of the neutron star in the Cassiopeia A supernova remnant using the recent result of Ho & Heinke that the thermal radiation of this star is well described by a carbon atmosphere model and the emission comes from the entire stellar surface. Starting from neutron star cooling theory, we formulate a robust method to extract neutrino cooling rates of thermally relaxed stars at the neutrino cooling stage from observations of thermal surface radiation. We show how to compare these rates with the rates of standard candles – stars with non-superfluid nucleon cores cooling slowly via the modified Urca process. We find that the internal temperature of standard candles is a well-defined function of the stellar compactness parameter x=rg/R, irrespective of the equation of state of neutron star matter (R and rg are circumferential and gravitational radii, respectively). We demonstrate that the data on the Cassiopeia A neutron star can be explained in terms of three parameters: f?, the neutrino cooling efficiency with respect to the standard candle; the compactness x; and the amount of light elements in the heat-blanketing envelope. For an ordinary (iron) heat-blanketing envelope or a low-mass (? 10?13 M?) carbon envelope, we find the efficiency f?? 1 (standard cooling) for x? 0.5 and f?? 0.02 (slower cooling) for a maximum compactness x? 0.7. A heat blanket containing the maximum mass (?10?8 M?) of light elements increases f? by a factor of 50. We also examine the (unlikely) possibility that the star is still thermally non-relaxe
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