410 research outputs found
CARBOTRAF: A decision Support system for reducing pollutant emissions by adaptive traffic management
Traffic congestion with frequent “stop & go” situations causes substantial pollutant emissions. Black carbon (BC) is a good indicator of combustion-related air pollution and results in negative health effects. Both BC and CO2 emissions are also known to contribute significantly to global warming. Current traffic control systems are designed to improve traffic flow and reduce congestion. The CARBOTRAF system combines real-time monitoring of traffic and air pollution with simulation models for emission and local air quality prediction in order to deliver on-line recommendations for alternative adaptive traffic management. The aim of introducing a CARBOTRAF system is to reduce BC and CO2 emissions and improve air quality by optimizing the traffic flows. The system is implemented and evaluated in two pilot cities, Graz and Glasgow. Model simulations link traffic states to emission and air quality levels. A chain of models combines micro-scale traffic simulations, traffic volumes, emission models and air quality simulations. This process is completed for several ITS scenarios and a range of traffic boundary conditions. The real-time DSS system uses all these model simulations to select optimal traffic and air quality scenarios. Traffic and BC concentrations are simultaneously monitored. In this paper the effects of ITS measures on air quality are analysed with a focus on BC
A study assessing the viability of using Fused Filament Fabrication (FFF) Additive Manufacturing (AM) technology to manufacture customised Class I medical devices
Additive manufacturing (AM) is becoming an increasingly common manufacturing method for medical devices due to the benefits of advanced customisation, improved fit and opportunities for innovation. However, many AM medical devices remain inaccessible due to high costs of hardware and consumables, and the large infrastructural requirements required for operation. Fused filament fabrication (FFF) is a highly accessible AM technique due to its open-source nature, which has led to an extensive market of affordable desktop 3D printers. In this work FFF has been demonstrated as a potentially viable technique to fabricate low-risk medical devices in two case studies presented in this thesis: a customised daily living aid and a range of medical devices in response to the COVID-19 pandemic.
Although the potential of the technology has been demonstrated, research around the practical suitability of FFF for medical applications remained limited, with much of the research in the field focussing on proof-of-concept applications, which did not explore the necessary requirements for the integration of the technology into daily clinical practices. This thesis investigates the fundamental requirements of the FFF AM technique for it to be used for Class I medical device applications in three identified use cases: non-specialist, research and industrial use. In keeping with the ambition for FFF to provide accessible solutions, mid-range hardware aimed at professional printing applications was selected to carry out this work, which encompasses the activities present in each of the three identified use cases.
A methodology was presented to determine the repeatability and reproducibility of FFF across three potential use cases, which revealed varying process capability between the X-, Y- and Z- printing directions for individual machines, and significant variation between multiple machines of the same make and model. The repeatability and reproducibility of the FFF technique was identified as a key limitation for the widespread adoption of FFF technology for specialist and industrial use. The smallest tolerance achieved from a professional desktop FFF printer was 0.3mm in both the X- and Y- directions, and 0.4mm in the Z-direction.
Additional variable factors were studied, including the condition of filament with respect to its storage environment and duration of storage, the influence of different colours and pigments present in filament and the use of an air management add-on unit intended to enhance the hardware. The glass transition temperature of Tough PLA remained largely unaffected from variable storage conditions, which when submerged in water decreased by around 1.4ºC from that of ambiently stored filament. The mechanical properties of printed parts were influenced by filament colour, with white filament producing parts with increased elongation and tensile strength than other colours studied. Dimensional accuracy in the Z-printing direction was affected by air management, where samples produced with air management were measured higher than the nominal value, and without air management lower than the nominal value.
This thesis is the first known work to explore the suitability of FFF technology for Class I medical devices, from the perspective of both specialist and non-specialist users. The key barriers to widespread adoption were identified as the repeatability and reproducibility of the technique, and the influence of variable factors on the process and part performance. The exploration of these continually referenced medical device regulations, whilst consideration was given to how the experimental work can be applied to real-world Class I medical device manufacturing applications
Слабка збіжність сім'ї напівмарковських процесів до дифузійного процесу
Наведено основні критерії слабкої збіжності сім'ї напівмарковських процесів до ''чисто'' дифузійного процесу в умовах балансу та до дифузійного процесу Орнштейна–Уленбека за умови, що величина стрибка залежить від параметра серії ε.Приведены основные критерии слабой сходимости семейства полумарковских процессов к ''чисто'' диффузионному процессу в условиях баланса и к диффузионному процессу Орнштейна–Уленбека при условии, что величина скачка зависит от параметра серии ε.The basic criteria of weak convergence of a family of semi-Markov processes to the ''pure'' diffusion process under balance conditions and to the Ornstein–Uhlenbeck diffusion process provided that the value of jump depends on the series parameter ε are obtained
Theophylline Restores Histone Deacetylase Activity and Steroid Responses in COPD Macrophages
Chronic obstructive pulmonary disease (COPD) is a common chronic inflammatory disease of the lungs with little or no response to glucocorticoids and a high level of oxidative stress. Histone deacetylase (HDAC) activity is reduced in cells of cigarette smokers, and low concentrations of theophylline can increase HDAC activity. We measured the effect of theophylline on HDAC activity and inflammatory gene expression in alveolar macrophages (AM) from patients with COPD. AM from normal smokers showed a decrease in HDAC activity compared with normal control subjects, and this was further reduced in COPD patients (51% decrease, P < 0.01). COPD AMs also showed increased basal release of IL-8 and TNF-α, which was poorly suppressed by dexamethasone. Theophylline induced a sixfold increase in HDAC activity in COPD AM lysates and significantly enhanced dexamethasone suppression of induced IL-8 release, an effect that was blocked by the HDAC inhibitor trichostatin A. Therefore, theophylline might restore steroid responsiveness in COPD patients
Pleistocene Niche Stability And Lineage Diversification In The Subtropical Spider Araneus Omnicolor (araneidae)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The influence of Quaternary climate oscillations on the diversification of the South American fauna is being increasingly explored. However, most of these studies have focused on taxa that are endemic to tropical environments, and relatively few have treated organisms restricted to subtropical biomes. Here we used an integrative phylogeographical framework to investigate the effects of these climate events on the ecological niche and genetic patterns of the subtropical orb-weaver spider Araneus omnicolor (Araneidae). We analyzed the mitochondrial (Cytochrome Oxidase I, COI) and nuclear (Internal Transcribed Subunit II, ITS2) DNA of 130 individuals throughout the species' range, and generated distribution models in three different climate scenarios [present, Last Glacial Maximum (LGM), and Last Interglacial Maximum (LIG)]. Additionally, we used an Approximate Bayesian Computation (ABC) approach to compare possible demographic scenarios and select the hypothesis that better explains the genetic patterns of A. omnicolor. We obtained high haplotype diversity but low nucleotide variation among sequences. The population structure and demographic analyses showed discrepancies between markers, suggesting male-biased dispersal in the species. The time-calibrated COI phylogenetic inference showed a recent diversification of lineages (Middle/Late Pleistocene), while the paleoclimate modeling indicated niche stability since similar to 120 Kya. The ABC results agreed with the niche models, supporting a panmictic population as the most likely historical scenario for the species. These results indicate that A. omnicolor experienced no niche or population reductions during the Late Pleistocene, despite the intense landscape modifications that occurred in the subtropical region, and that other factors beside LGM and LIG climate oscillations might have contributed to the demographic history of this species. This pattern may be related to the high dispersal ability and wide environmental tolerance of A. omnicolor, highlighting the need for more phylogeographical studies with invertebrates and other generalist taxa, in order to understand the effects of Quaternary climate changes on Neotropical biodiversity.104Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2012/02526-7
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Optical, electrical and chemical properties of PEO:I2 complex composite films
Synthesized PEO:I2 complex composite films with different I2 concentrations were deposited onto fused silica substrates using a dip-coating method. Incorporation of PEO films with I2 increases the electrical conductivity of the composite, reaching a maximum of 46 mS/cm for 7 wt% I2. The optical and optoelectronic properties of the complex composite films were studied using the transmittance and reflectance spectra in the UV-Vis region. The transmittance of PEO decreases with increasing I2 content. From this study, the optical bandgap energy decreases from 4.42 to 3.28 eV as I2 content increases from 0 to 7 wt%. In addition, the refractive index for PEO films are in the range of 1.66 and 2.00.1H NMR spectra of pure PEO film shows two major peaks at 3.224 ppm and 1.038 ppm, with different widths assigned to the mobile polymer chains in the amorphous phase, whereas the broad component is assigned to the more rigid molecules in the crystalline phase, respectively. By adding I2 to the PEO, both peaks (amorphous and crystal) are shifted to lower NMR frequencies indicating that I2 is acting as a Lewis acid, and PEO is acting as Lewis base. Hence, molecular iodine reacts favorably with PEO molecules through a charge transfer mechanism, and the formation of triiodide (I3-), the iodite (IO2-) anion, I 2· · · PEO and I2+···PEO complexes. PEO:I2 complex composite films are expected to be suitable for optical, electrical, and optoelectronic applications
Preimplantation Genetic Diagnosis in cattle: A review
Preimplantation Genetic Diagnosis (PGD) is reviewed and novel fields where it may be applied are investigated. Technical advances of PGD in cattle embryos have already enabled its integration as a part of the MOET (Multiple Ovulation Embryo Transfer) breeding system. PGD for well-defined selection targets can enhance cattle breeding and embryo trade. It allows embryo selection according to their sex, and it may be used to breed special cow lines, or top bulls, by selecting embryos for valuable production traits using Marker Assisted Selection (MAS). A good allelic profile and/or the insertion of a transgene can be detected by PGD. This review article presents the technical requirements for PGD, and shows that this biotechnological method has great economic potential
Mutations in pericentrin cause Seckel syndrome with defective ATR-dependent DNA damage signaling
Large brain size is one of the defining characteristics of modern humans. Seckel syndrome (MIM 210600), a disorder of markedly reduced brain and body size, is associated with defective ATR-dependent DNA damage signaling. Only a single hypomorphic mutation of ATR has been identified in this genetically heterogeneous condition. We now report that mutations in the gene encoding pericentrin (PCNT)--resulting in the loss of pericentrin from the centrosome, where it has key functions anchoring both structural and regulatory proteins--also cause Seckel syndrome. Furthermore, we find that cells of individuals with Seckel syndrome due to mutations in PCNT (PCNT-Seckel) have defects in ATR-dependent checkpoint signaling, providing the first evidence linking a structural centrosomal protein with DNA damage signaling. These findings also suggest that other known microcephaly genes implicated in either DNA repair responses or centrosomal function may act in common developmental pathways determining human brain and body size
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