196 research outputs found
Moore's Law
Mooreâs law originally was the observation that the number of transistors on integrated circuits doubles roughly every 18 months. However, many other areas of technology progress with a similar exponential growth. For instance, can one find an analogous law in the context of super-computing? The aim of this paper is to answer this question by showing how a variant of Mooreâs law emerges from an analysis of the âTop 500â lists of super computers from 1993 to 2013
Cobalt Phthalocyanine Modified Electrodes Utilised in Electroanalysis: Nano-Structured Modified Electrodes vs. Bulk Modified Screen-Printed Electrodes
Cobalt phthalocyanine (CoPC) compounds have been reported to provide electrocatalytic performances towards a substantial number of analytes. In these configurations, electrodes are typically constructed via drop casting the CoPC onto a supporting electrode substrate, while in other cases the CoPC complex is incorporated within the ink of a screen-printed sensor, providing a one-shot economical and disposable electrode configuration. In this paper we critically compare CoPC modified electrodes prepared by drop casting CoPC nanoparticles (nano-CoPC) onto a range of carbon based electrode substrates with that of CoPC bulk modified screen-printed electrodes in the sensing of the model analytes L-ascorbic acid, oxygen and hydrazine. It is found that no âelectrocatalysisâ is observed towards L-ascorbic acid using either of these CoPC modified electrode configurations and that the bare underlying carbon electrode is the origin of the obtained voltammetric signal, which gives rise to useful electroanalytical signatures, providing new insights into literature reports where âelectrocatalysisâ has been reported with no clear control experiments undertaken. On the other hand true electrocatalysis is observed towards hydrazine, where no such voltammetric features are witnessed on the bare underlying electrode substrate
Phosphine-alkene ligand-mediated alkyl-alkyl and alkyl-halide elimination processes from palladium(II)
N-Diphenylphosphino-7-aza-benzobicyclo[2.2.1]hept-2-ene (2) behaves as a chelating phosphineâalkene ligand for Pd0 and PdII, promoting direct alkylâalkyl and indirect alkylâhalide reductive elimination reactions due to the stabilisation of the resulting bis(phosphineâalkene)Pd0 complex
Antibacterial and anti-virulence activity of manuka honey against genetically diverse Staphylococcus pseudintermedius strains
Staphylococcus pseudintermedius causes opportunistic infections in dogs. It also has significant zoonotic potential, with the emergence of multidrug-resistance leading to difficulty treating both animal and human infections. Manuka honey has previously been reported to inhibit many bacterial pathogens including methicillin resistant Staphylococcus aureus and is successfully utilised in both clinical and veterinary practice. Here we evaluated the ability of manuka honey to inhibit strains of S. pseudintermedius growth alone and in combination with antibiotics, and its capacity to modulate virulence within multiple S. pseudintermedius. All 18 of the genetically diverse S. pseudintermedius strains sequenced and tested were inhibited by †12% (w/v) medical grade manuka honey, although tolerance to five clinically relevant antibiotics was observed. The susceptibility of the isolates to four of these antibiotics was significantly increased (p â€0.05) when combined with sub lethal concentrations of honey, although sensitivity to oxacillin was decreased. Virulence (DNase, protease and haemolysin) activity was also significantly reduced (p †0.05) in over half of isolates when cultured with sub lethal concentrations of honey (13, 9 and 10 isolates respectively). These findings highlight the potential for manuka honey to be utilised against S. pseudintermedius infections. Importance: Staphylococcus pseudintermedius is an important member of the skin microbial community in animals and can cause opportunistic infections in both pets and their owners. The high incidence of antimicrobial resistance in S. pseudintermedius highlights that this opportunistic zoonotic pathogen can cause infections which require prolonged and intensive treatment to resolve. Manuka honey has proven efficacy against many bacterial pathogens and is an accepted topical treatment for infections in both veterinary and clinical practice so is a particularly appropriate antimicrobial for use with zoonotic pathogens such as S. pseudintermedius. Here we demonstrate that manuka honey is not only highly potent against novel multi-drug resistant S. pseudintermedius isolates, but also acts synergistically with clinically relevant antibiotics. In addition, manuka honey modulates S. pseudintermedius virulence activity, even at subinhibitory concentrations. In a clinical setting these attributes may assist in controlling infection, allowing a more rapid resolution and reducing antibiotic use
Catalytic dehydrocoupling of Amine-Boranes Using Cationic Zirconium(IV)-Phosphine Frustrated Lewis Pairs
A series
of novel, intramolecular ZrÂ(IV)/P frustrated Lewis pairs
(FLPs) based on cationic zirconocene fragments with a variety of ancillary
cyclopentadienyl and 2-phosphinoaryloxide (âOÂ(C<sub>6</sub>H<sub>4</sub>)ÂPR<sub>2</sub>, R = <sup>t</sup>Bu and 3,5-CF<sub>3</sub>-(C<sub>6</sub>H<sub>3</sub>)) ligands are reported and their activity
as catalysts for the dehydrocoupling of dimethylamineâborane
(Me<sub>2</sub>NH·BH<sub>3</sub>) assessed. The FLP system [(C<sub>9</sub>H<sub>7</sub>)<sub>2</sub>ZrOÂ(C<sub>6</sub>H<sub>4</sub>)ÂP<sup>t</sup>Bu<sub>2</sub>]Â[BÂ(C<sub>6</sub>F<sub>5</sub>)<sub>4</sub>]
is shown to give unprecedented turnover frequencies (TOF) for a catalyst
based on a group 4 metal (TOF â„ 600 h<sup>â1</sup>),
while also proving to be the most efficient FLP catalyst reported
to date. The mechanism of this reaction has been probed using analogous
intermolecular ZrÂ(IV)/P FLPs, permitting deconvolution of the reactions
taking place at both the Lewis acidic and basic sites. Elucidation
of this mechanism revealed an interesting cooperative two-cycle process
where one cycle is FLP mediated and the other, a redistribution of
a linear diborazane intermediate, relies solely on the presence of
a ZrÂ(IV) Lewis acid
Psychological advocacy toward healing (PATH): study protocol for a randomized controlled trial.
BACKGROUND: Domestic violence and abuse (DVA), defined as threatening behavior or abuse by adults who are intimate partners or family members, is a key public health and clinical priority. The prevalence of DVA in the United Kingdom and worldwide is high, and its impact on physical and mental health is detrimental and persistent. There is currently little support within healthcare settings for women experiencing DVA. Psychological problems in particular may be difficult to manage outside specialist services, as conventional forms of therapy such as counseling that do not address the violence may be ineffective or even harmful. The aim of this study is to assess the overall effectiveness and cost-effectiveness of a novel psychological intervention tailored specifically for survivors of DVA and delivered by domestic violence advocates based in third-sector organizations. METHODS AND STUDY DESIGN: This study is an open, pragmatic, parallel group, individually randomized controlled trial. Women ages 16 years and older experiencing domestic violence are being enrolled and randomly allocated to receive usual DVA agency advocacy support (control) or usual DVA agency support plus psychological intervention (intervention). Those in the intervention group will receive eight specialist psychological advocacy (SPA) sessions weekly or fortnightly, with two follow-up sessions, 1 month and then 3 months later. This will be in addition to any advocacy support sessions each woman receives. Women in the control group will receive usual DVA agency support but no additional SPA sessions. The aim is to recruit 250 women to reach the target sample size. The primary outcomes are psychological well-being and depression severity at 1 yr from baseline, as measured by the Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM) and the Patient Health Questionnaire (PHQ-9), respectively. Secondary outcome measures include anxiety, posttraumatic stress, severity and frequency of abuse, quality of life and cost-effectiveness of the intervention. Data from a subsample of women in both groups will contribute to a nested qualitative study with repeat interviews during the year of follow-up. DISCUSSION: This study will contribute to the evidence base for management of the psychological needs of women experiencing DVA. The findings will have important implications for healthcare commissioners and providers, as well as third sector specialist DVA agencies providing services to this client group. TRIAL REGISTRATION: ISRCTN58561170
Extreme water levels, waves and coastal impacts during a severe tropical cyclone in northeastern Australia: a case study for cross-sector data sharing
Severe tropical cyclone (TC) Debbie made landfall on
the northern Queensland coast of Australia on 27 March 2017 after crossing
the Great Barrier Reef as a slow-moving Category 4 system. Groups from
industry, government and academia collected coastal hazard and impact data
before, during and after the event and shared these data to produce a
holistic picture of TC Debbie at the coast. Results showed the still
water level exceeded the highest astronomical tide by almost a metre. Waves
added a further 16 % to water levels along the open coast, and were
probably unprecedented for this area since monitoring began. In most places,
coastal barriers were not breached and as a result there was net offshore
sand transport. If landfall had occurred 2 h earlier with the high tide,
widespread inundation and overwash would have ensued. This paper provides a
case study of effective cross-sector data sharing in a natural hazard
context. It advocates for a shared information platform for coastal extremes
in Australia to help improve the understanding and prediction of TC-related
coastal hazards in the future.</p
Intoxicants and the invention of 'consumption'
In 1600 the word âconsumptionâ was a term of medical pathology describing the âwasting, petrification of thingsâ. By 1700 it was also a term of economic discourse: âIn commodities, the value rises as its quantity is less and vent greater, which depends upon it being preferred in its consumptionâ. The article traces the emergence of this key category of economic analysis to debates over the economy in the 1620s and subsequent disputes over the excise tax, showing how âconsumptionâ was an early term in the developing lexicon of political economy. In so doing the article demonstrates the important role of âintoxicantsâ â i.e. addictive and intoxicating commodities like alcohols and tobaccos â in shaping these early meanings and uses of âconsumptionâ. It outlines the discursive importance of intoxicants, both as the foci for discussions of âsuperfluousâ and ânecessaryâ consumption and the target of legislation on consumption. And it argues that while these discussions had an ideological dimension, or dimensions, they were also responses to material increases in the volume and diversity of intoxicants in early seventeenth-century England. By way of conclusion the article suggests the significance of the Low Countries as a point of reference for English writers, as well as a more capacious and semantically sensitive approach to changes in early-modern consumption practices
Genetically manipulated phages with improved pH resistance for oral administration in veterinary medicine
Orally administered phages to control zoonotic pathogens face important challenges, mainly related to the hostile conditions found in the gastrointestinal tract (GIT). These include temperature, salinity and primarily pH, which is exceptionally low in certain compartments. Phage survival under these conditions can be jeopardized and undermine treatment. Strategies like encapsulation have been attempted with relative success, but are typically complex and require several optimization steps. Here we report a simple and efficient alternative, consisting in the genetic engineering of phages to display lipids on their surfaces. Escherichia coli phage T7 was used as a model and the E. coli PhoE signal peptide was genetically fused to its major capsid protein (10A), enabling phospholipid attachment to the phage capsid. The presence of phospholipids on the mutant phages was confirmed by High Performance Thin Layer Chromatography, Dynamic Light Scattering and phospholipase assays. The stability of phages was analysed in simulated GIT conditions, demonstrating improved stability of the mutant phages with survival rates 102107 pfu.mL1 higher than wild-type phages. Our work demonstrates that phage engineering can be a good strategy to improve phage tolerance to GIT conditions, having promising application for oral administration in veterinary medicine.This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and under the scope of the Project PTDC/BBB-BSS/6471/2014 (POCI-01-0145-FEDER-016678). Franklin L. Nobrega and Ana Rita Costa acknowledge FCT for grants SFRH/BD/86462/2012 and SFRH/BPD/94648/2013, respectively. Melvin F. Siliakus acknowledges funding from the Biobased Ecologically Balanced Sustainable Industrial Chemistry (BE-BASIC) foundation. Electron microscopy work was performed at the Wageningen Electron Microscopy Centre (WEMC) of Wageningen University
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