47 resultados para Concentrate


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In this paper a multiscale simulation study was carried out in order to gain in-depth understanding of machining mechanism of nanometric cutting of single crystal copper. This study was focused on the effects of crystal orientation and cutting direction on the attainable machined surface quality. The machining mechanics was analyzed through cutting forces, chip formation morphology, generation and evolution of defects and residual stresses on the machined surface. The simulation results showed that the crystal orientation of the copper material and the cutting direction significantly influenced the deformation mechanism of the workpiece materials during the machining process. Relatively lower cutting forces were experienced while selecting crystal orientation family {1 1 1}. Dislocation movements were found to concentrate in front of the cutting chip while cutting on the (1 1 1) surface along the View the MathML source cutting direction thus, resulting in much smaller damaged layer on the machined surface, compared to other orientations. This crystal orientation and cutting direction therefore recommended for nanometric cutting of single crystal copper in practical applications. A nano-scratching experiment was performed to validate the above findings.

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This paper will examine some of the ways in which processes of denomination
have shaped Northern Irish politics before and after the ‘Belfast’, or ‘Good Friday
Agreement’ of 1998. We concentrate on the formation of the ‘Unionist’ or ‘Loyalist
community’, principally because the flag protests of 2012-2013 have brought the
issue of this community identity to the fore again. The flag is part of a whole
machinery of what we, in this paper, will call ‘denomination’ in Northern Irish
politics and elsewhere. The religious overtones of the term are neither accidental
nor incidental. Acts of denomination posit (assertively, authoritatively) a
collective identity, conceived and constituted ontologically, as an existent entity,
and stake a claim to a whole territory.

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Background: This study assessed the association between adolescent ecstasy use and depressive symptoms in adolescence. Methods: The Belfast Youth Development Study surveyed a cohort annually from age 11 to 16 years. Gender, Strengths and Difficulties Questionnaire emotional subscale, living arrangements, parental affluence, parent and peer attachment, tobacco, alcohol, cannabis and ecstasy use were investigated as predictors of Short Mood and Feelings Questionnaire (SMFQ) outcome. Results: Of 5371 respondents, 301 (5.6%) had an SMFQ > 15, and 1620 (30.2) had missing data for SMFQ. Around 8% of the cohort had used ecstasy by the end of follow-up. Of the non-drug users, ∼2% showed symptoms of depression, compared with 6% of those who had used alcohol, 6% of cannabis users, 6% of ecstasy users and 7% of frequent ecstasy users. Without adjustment, ecstasy users showed around a 4-fold increased odds of depressive symptoms compared with non-drug users [odds ratio (OR) = 0.26; 95% confidence interval (CI) = 0.10, 0.68]. Further adjustment for living arrangements, peer and parental attachment attenuated the association to under a 3-fold increase (OR = 0.37; 95% CI = 0.15, 0.94). There were no differences by frequency of use. Conclusions: Ecstasy use during adolescence may be associated with poorer mental health; however, this association can be explained by the confounding social influence of family dynamics. These findings could be used to aid effective evidence-based drug policies, which concentrate criminal justice and public health resources on reducing harm.

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Trajectory surface hopping (TSH) is one of the most widely used quantum-classical algorithms for nonadiabatic molecular dynamics. Despite its empirical effectiveness and popularity, a rigorous derivation of TSH as the classical limit of a combined quantum electron-nuclear dynamics is still missing. In this work, we aim to elucidate the theoretical basis for the widely used hopping rules. Naturally, we concentrate thereby on the formal aspects of the TSH. Using a Gaussian wave packet limit, we derive the transition rates governing the hopping process at a simple avoided level crossing. In this derivation, which gives insight into the physics underlying the hopping process, some essential features of the standard TSH algorithm are retrieved, namely (i) non-zero electronic transition rate ("hopping probability") at avoided crossings; (ii) rescaling of the nuclear velocities to conserve total energy; (iii) electronic transition rates linear in the nonadiabatic coupling vectors. The well-known Landau-Zener model is then used for illustration. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4770280]

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The historic significance of the Good Friday Agreement and its role in ending organized political violence is acknowledged at the outset. The article then goes on to probe the roots of the political paralysis built into the architecture of the Agreement that are predicated on a misplaced political and cultural symmetry between the “two communities.” It is suggested that the institutionalized relationship between Northern Ireland and the rest of the U.K. facilitates a cross-party, populist, socio-economic consensus among the nationalist and unionist political parties on the welfare state, taxation and maintaining the massive British subvention to the region. This in turn allows them to concentrate on a divisive culturalist politics, i.e., on antagonistic forms of cultural and identity politics over such issues as flags, parades, and the legacy of the “Troubles” which spills over into gridlock into many areas of regional administration. The article argues for a much broader understanding of culture and identity rooted in the different, if overlapping and interdependent, material realities of both communities while challenging the idea of two cultures/identities as fixed, mutually exclusive, non-negotiable and mutually antagonistic. It then focuses on the importance of Belfast as a key arena which will determine the long-term prospects of an alternative and more constructive form of politics, and enable a fuller recognition of the fundamental asymmetries and inter-dependence between the “two communities.” In the long run, this involves re-defining and reconstructing what is meant by the “Union” and a “United Ireland.”

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Justice for victims has often been invoked as the raison d’être of international criminal justice, by punishing perpetrators of international crimes. This article attempts to provide a more holistic account of justice for victims by examining victims’ needs, interests, and rights. The International Criminal Court itself includes participation, protection and reparation for victims, indicating they are important stakeholders. This article also suggests that victims are integral to the purpose of the ICC in ending impunity by ensuring transparency of proceedings. However, there are limits to the resources and capacity of the ICC, which can only investigate and prosecute selected crimes. To overcome this justice gap, this article directs the debate towards a victim-orientated agenda to complementarity, where state parties and the Assembly of State Parties should play a greater role in implementing justice for victims domestically. This victim-orientated complementarity approach can be achieved through new ASP guidelines on complementarity, expanding universal jurisdiction, or seeking enforcement and cooperation through regional and international bodies and courts, such asUniversal Periodic Review or the African Court’s International Criminal Law Section. In the end, ifwe are serious about delivering justice for victims we need to move beyond the rhetoric, with realistic expectations of what the ICC can achieve, and concentrate our attention to what states should bedoing to end impunity.

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Title
Psychosocial interventions to improve quality of life and emotional wellbeing for recently diagnosed cancer patients.

Background
Despite clear guidelines recommending the provision of emotional support for cancer patients, we do not know how best to address psychological distress in this group.

Aim
To assess the effects of psychosocial interventions to improve quality of life (QoL) and general psychological distress newly diagnosed cancer patients.

Methods
We searched electronic sources for RCTs of psychosocial interventions or ‘talking therapies’ with individual newly diagnosed cancer patients. Only trials measuring QoL and general psychological distress were included. Meta-analyses examined subgroups by outcome measurement, mode of delivery and discipline of trained helper.

Results
Thirty trials met the criteria. No significant effects were observed for QoL at 6-months (SMD 0.11; 95% CI -0.00 to 0.22) except when using cancer-specific measures (SMD 0.16; 95% CI 0.02 to 0.30). Sub-group analyses revealed that psycho-educational, nurse-delivered interventions improved QoL (SMD 0.23; 95% CI 0.04 to 0.43). General psychological distress as assessed by ‘mood measures’ improved (SMD - 0.81; 95% CI -1.44 to -0.18), but heterogeneity was a factor.

Discussion and conclusion
Psychosocial interventions vary in format and content, raising concerns about heterogeneity, despite appearing to have a beneficial impact on cancer-specific QoL and mood. Future research should concentrate on screening for emotional support needs and identifying common elements within interventions that are of value. Authors should carefully select outcome measures that are appropriately sensitive to change.

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Title
Psychosocial interventions to improve quality of life and emotional wellbeing for recently diagnosed cancer patients.

Background
Despite clear guidelines recommending the provision of emotional support for cancer patients, we do not know how best to address psychological distress in this group.

Aim
To assess the effects of psychosocial interventions to improve quality of life (QoL) and general psychological distress newly diagnosed cancer patients.

Methods
We searched electronic sources for RCTs of psychosocial interventions or ‘talking therapies’ with individual newly diagnosed cancer patients. Only trials measuring QoL and general psychological distress were included. Meta-analyses examined subgroups by outcome measurement, mode of delivery and discipline of trained helper.

Results
Thirty trials met the criteria. No significant effects were observed for QoL at 6-months (SMD 0.11; 95% CI -0.00 to 0.22) except when using cancer-specific measures (SMD 0.16; 95% CI 0.02 to 0.30). Sub-group analyses revealed that psycho-educational, nurse-delivered interventions improved QoL (SMD 0.23; 95% CI 0.04 to 0.43). General psychological distress as assessed by ‘mood measures’ improved (SMD - 0.81; 95% CI -1.44 to -0.18), but heterogeneity was a factor.

Discussion and conclusion
Psychosocial interventions vary in format and content, raising concerns about heterogeneity, despite appearing to have a beneficial impact on cancer-specific QoL and mood. Future research should concentrate on screening for emotional support needs and identifying common elements within interventions that are of value. Authors should carefully select outcome measures that are appropriately sensitive to change.

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We review the physics of hybrid optomechanical systems consisting of a mechanical oscillator interacting with both a radiation mode and an additional matterlike system. We concentrate on the cases embodied by either a single or a multi-atom system (a Bose-Einstein condensate, in particular) and discuss a wide range of physical effects, from passive mechanical cooling to the set-up of multipartite entanglement, from optomechanical nonlocality to the achievement of non-classical states of a single mechanical mode. The reviewed material showcases the viability of hybridised cavity optomechanical systems as basic building blocks for quantum communication networks and quantum state-engineering devices, possibly empowered by the use of quantum and optimal control techniques. The results that we discuss are instrumental to the promotion of hybrid optomechanical devices as promising experimental platforms for the study of nonclassicality at the genuine mesoscopic level.

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High-frequency fluctuations are observed with the Rapid Oscillations in the Solar Atmosphere (ROSA) instrument (Jess et al. 2010, Solar Phys, 261, 363) at the Dunn Solar Telescope. This can produce simultaneous observations in up to six channels, at different heights in the photosphere and chromosphere, at an unprecedentedly high cadence of 0.5 seconds, and at a spatial resolution of 100 km after photometrically correct speckle reconstruction. Here we concentrate on observations at two levels. The first is in the G-band of the CH radical at 4305.5Å, bandpass 9.2Å, with height of formation z <250 km at a cadence of 0.525 sec corresponding to Nyquist frequency 950 mHz. The second is in the Ca II K-line core at 3933.7Å, bandpass 1.0Å, with height of formation z <1300 km, and cadence 4.2 sec giving Nyquist frequency 120 mHz. The data span 53 min, and the maximum field of view is 45 Mm. The data were taken on 28 May 2009 in internetwork and network near disk center. Using both Fourier and Morlet wavelet methods we find evidence in the G-band spectra for intensity fluctuations above noise out to frequencies f >> 100 mHz. The K-line signal is noisier and is seen only for f <50 mHz. With wavelet techniques we find that G-band spectral power with 20 <f <100 mHz is clearly concentrated in the intergranular lanes and especially at the locations of magnetic elements indicated by G-band bright points. This wavelet power is highly intermittent in time. By cross-correlating the data we find that pulses of high-frequency G-band power in the photosphere tend to be followed by increases in K-line emission in the chromosphere with a time lag of about 2 min.

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Homomorphic encryption offers potential for secure cloud computing. However due to the complexity of homomorphic encryption schemes, performance of implemented schemes to date have been unpractical. This work investigates the use of hardware, specifically Field Programmable Gate Array (FPGA) technology, for implementing the building blocks involved in somewhat and fully homomorphic encryption schemes in order to assess the practicality of such schemes. We concentrate on the selection of a suitable multiplication algorithm and hardware architecture for large integer multiplication, one of the main bottlenecks in many homomorphic encryption schemes. We focus on the encryption step of an integer-based fully homomorphic encryption (FHE) scheme. We target the DSP48E1 slices available on Xilinx Virtex 7 FPGAs to ascertain whether the large integer multiplier within the encryption step of a FHE scheme could fit on a single FPGA device. We find that, for toy size parameters for the FHE encryption step, the large integer multiplier fits comfortably within the DSP48E1 slices, greatly improving the practicality of the encryption step compared to a software implementation. As multiplication is an important operation in other FHE schemes, a hardware implementation using this multiplier could also be used to improve performance of these schemes.

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The World Health Organization estimates that 13 million children aged 5-15 years worldwide are visually impaired from uncorrected refractive error. School vision screening programs can identify and treat or refer children with refractive error. We concentrate on the findings of various screening studies and attempt to identify key factors in the success and sustainability of such programs in the developing world. We reviewed original and review articles describing children's vision and refractive error screening programs published in English and listed in PubMed, Medline OVID, Google Scholar, and Oxford University Electronic Resources databases. Data were abstracted on study objective, design, setting, participants, and outcomes, including accuracy of screening, quality of refractive services, barriers to uptake, impact on quality of life, and cost-effectiveness of programs. Inadequately corrected refractive error is an important global cause of visual impairment in childhood. School-based vision screening carried out by teachers and other ancillary personnel may be an effective means of detecting affected children and improving their visual function with spectacles. The need for services and potential impact of school-based programs varies widely between areas, depending on prevalence of refractive error and competing conditions and rates of school attendance. Barriers to acceptance of services include the cost and quality of available refractive care and mistaken beliefs that glasses will harm children's eyes. Further research is needed in areas such as the cost-effectiveness of different screening approaches and impact of education to promote acceptance of spectacle-wear. School vision programs should be integrated into comprehensive efforts to promote healthy children and their families.

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As the ESA Rosetta mission approached, orbited, and sent a lander to comet 67P/Churyumov-Gerasimenko in 2014, a large campaign of ground-based observations also followed the comet. We constrain the total activity level of the comet by photometry and spectroscopy to place Rosetta results in context and to understand the large-scale structure of the comet's coma pre-perihelion. We performed observations using a number of telescopes, but concentrate on results from the 8m VLT and Gemini South telescopes in Chile. We use R-band imaging to measure the dust coma contribution to the comet's brightness and UV-visible spectroscopy to search for gas emissions, primarily using VLT/FORS. In addition we imaged the comet in near-infrared wavelengths (JHK) in late 2014 with Gemini-S/Flamingos 2. We find that the comet was already active in early 2014 at heliocentric distances beyond 4 au. The evolution of the total activity (measured by dust) followed previous predictions. No gas emissions were detected despite sensitive searches. The comet maintains a similar level of activity from orbit to orbit, and is in that sense predictable, meaning that Rosetta results correspond to typical behaviour for this comet. The gas production (for CN at least) is highly asymmetric with respect to perihelion, as our upper limits are below the measured production rates for similar distances post-perihelion in previous orbits.

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Transitional justice is concerned with the legal and social processes established to deal with the legacy of violence in post-conflict and post-authoritarian contexts. These processes are essentially “creatures of law” – they are established by statute, their work is molded and shaped by lawyers, and their outcomes are benchmarked against what is or is not acceptable in domestic and international law. Concerns have mounted in recent years about the dominance of legalism within the field and the instrumentalization of those most directly affected by past violence. A commonly prescribed – but as yet largely empirically untested – corrective is that transitional justice theory and practice must become more open to interdisciplinary insights and perspectives. The interview – in different guises, contexts and settings – is at the heart of most transitional justice processes. As a historian now working in a School of Law I reflect in this article on the theoretical and practical intersections between law, history, and the interview. Drawing on more than 200 interviews concerning the Northern Ireland conflict and six other international case studies I concentrate in particular on interview-based initiatives that purport to be “victim-centered”. Having identified three interrelated risks - the manipulation of victim voice by vested interests, the affording of authority to particular voices, and the reification or “freezing” of identity - and having related these to the constraints of legal mechanisms and a wider failure to manage victims’ expectations, I argue that a greater familiarity with oral history theory and praxis can usefully illuminate the tensions between legal and historical approaches to engaging voice, and ultimately offer guidance to the shared challenge of victim-centered transitional justice.

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Heterocyclic aromatic amines (HCA) are carcinogenic mutagens formed during cooking of protein-rich foods. HCA residues adducted to blood proteins have been postulated as biomarkers of HCA exposure. However, the viability of quantifying HCAs following hydrolytic release from adducts in vivo and correlation with dietary intake are unproven. To definitively assess the potential of labile HCA-protein adducts as biomarkers, a highly sensitive UPLC-MS/MS method was validated for four major HCAs: 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) and 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline (7,8-DiMeIQx). Limits of detection were 1e5 pg/ml plasma and recoveries 91e115%. Efficacy of hydrolysis was demonstrated by HCA-protein adducts synthesised in vitro. Plasma and 7-day food diaries were collected from 122 fasting adults consuming their habitual diets. Estimated HCA intakes ranged from 0 to 2.5 mg/day. An extensive range of hydrolysis conditions was examined for release of adducted HCAs in plasma. HCA was detected in only one sample (PhIP, 9.7 pg/ml), demonstrating conclusively for the first time that acid-labile HCA adducts do not reflect dietary HCA intake and are present at such low concentrations that they are not feasible biomarkers of exposure. Identification of biomarkers remains important. The search should concentrate on stabilised HCA peptide markers and use of untargeted proteomic and metabolomic approaches.