FEM based mathematical modelling of thrust force during drilling of Al7075-T6

Like most machining processes, drilling is affected by many parameters such as the tool diameter, the cutting speed and feed. The current research investigates the possibility of developing a finite element modelling based prediction model for the generated thrust force during drilling of Al7075-T6 with solid carbide tools. A total of 27 drilling experiments were carried out in order to examine the interaction between three key parameters and their effect on thrust force. In addition, simulations of the experiments were realized with the use of DEFORM3D((TM))software in order to obtain the necessary numerical data. Finally, a comparison was made between the experimental and the numerical results to verify that reliable modelling is feasible. The mathematical model was acquired with the use of response surface methodology and the verification of the adequacy of the model was performed through an analysis of variance. The majority of the simulations yielded results in agreement with the experimental results at around 95% and the derived model offered an accuracy of 5.9%

Perspectives on palliative oxygen for breathlessness: systematic review and meta-synthesis.

Oxygen therapy is frequently prescribed for the palliation of breathlessness, despite lack of evidence for its effectiveness in people who are not hypoxaemic. This study aimed to compare and contrast patients', caregivers' and clinicians' experiences of palliative oxygen use for the relief of chronic breathlessness in people with advanced life-limiting illnesses, and how this shapes prescribing.A systematic review and meta-synthesis of qualitative data was conducted. MEDLINE, CINAHL and PsycINFO were searched for peer-reviewed studies in English (2000-April 2019) reporting perspectives on palliative oxygen use for reducing breathlessness in people with advanced illnesses in any healthcare setting. After data extraction, thematic synthesis used line-by-line coding of raw data (quotes) to generate descriptive and analytical themes.Of 457 articles identified, 22 met the inclusion criteria by reporting perspectives of patients (n=337), caregivers (n=91) or clinicians (n=616). Themes common to these perspectives were: 1) benefits and burdens of palliative oxygen use, 2) knowledge and perceptions of palliative oxygen use beyond the guidelines, and 3) longitudinal trajectories of palliative oxygen use.There are differing perceptions regarding the benefits and burdens of using palliative oxygen. Clinicians should be aware that oxygen use may generate differing goals of therapy for patients and caregivers. These perceptions should be taken into consideration when prescribing oxygen for the symptomatic relief of chronic breathlessness in patients who do not quality for long-term oxygen therapy

Quantum information processing in mesoscopic systems

This thesis discusses various schemes and protocols for quantum information processing in mesoscopic systems with particular focus on using the spin of a particle as the bearer of information. The first chapter introduce various aspects of the field of quantum information used in this thesis such as qubits, entanglement, its quantification, quantum logic gates and entanglement swapping. In this chapter concepts such as AKLT states, decoherence and adiabatic elimination are introduced as they will be relevant in the thesis. In chapter 2 we introduce the Quantum Dots as the solid state system that will primarily be used as the hardware for the development of Quantum Information Processing (QIP). The different properties of quantum dots depending on their size are discussed. The exchange interaction between tunnel coupled quantum dots and the background of quantum computation in quantum dots is described. The principal sources of decoherence and the measurement techniques for spin qubits are presented. In chapter 3, carbon nanowires filled with N@C60 dimers are studied to analyse the entanglement between nuclear spins. The dimer is modelled as a two coupled nuclear spin- electron spin pair with a Heisenberg interaction. The entanglement have been studied depending on the temperature and the intensity of an external magnetic field. Witnessing the entanglement, and particularly bound entanglement are discussed. In chapter 4, the way to extract a singlet from a quantum dot is explored. The system that we model will be consisting of a triple dot and analyse the best way to get the singlet out, with each electron in a separate dot. The chief motivation is to create a singlet between separate dots in a time-scale much faster than that given by spinspin exchange interactions. In chapter 5, quantum logic gates in a triple dot system has been studied. Such gates have been widely studied in double and single quantum dots. Motivated by the advent of experimental set ups of triple dots, we have studied the natural quantum gates that came out of a triple dot system. There are still two spin quantum bits in the three dots and there is an empty intervening dot, which imparts the scheme some advantages, as well as a substantial difference from the class of schemes studied so far. In chapter 6, we model a large square dot. As we describe in chapter 2, the properties of the large dots make them behave with some interesting properties such as hosting Wigner molecules of electrons inside. We explore the application of these structures for quantum information processing. We show here how to get singlet/triplet measurement, entanglement swapping, and how to prepare a 1D AKLT state, using the square dot as a construction block of the system. Finally in chapter 7 conclusions and further work. Here we indicate the further work that could be done with the knowledge present in this thesis and motivated by future advances in the technology

Systematic study of constitutive cyclo-oxygenase-2 expression: role of NFκB and NFAT transcriptional pathways

Cyclooxygenase-2 (COX-2) is an inducible enzyme that drives inflammation and is the therapeutic target for widely used nonsteroidal antiinflammatory drugs (NSAIDs). However, COX-2 is also constitutively expressed, in the absence of overt inflammation, with a specific tissue distribution that includes the kidney, gastrointestinal tract, brain, and thymus. Constitutive COX-2 expression is therapeutically important because NSAIDs cause cardiovascular and renal side effects in otherwise healthy individuals. These side effects are now of major concern globally. However, the pathways driving constitutive COX-2 expression remain poorly understood. Here we show that in the kidney and other sites, constitutive COX-2 expression is a sterile response, independent of commensal microorganisms and not associated with activity of the inflammatory transcription factor NF-κB. Instead, COX-2 expression in the kidney but not other regions colocalized with nuclear factor of activated T cells (NFAT) transcription factor activity and was sensitive to inhibition of calcineurin-dependent NFAT activation. However, calcineurin/NFAT regulation did not contribute to constitutive expression elsewhere or to inflammatory COX-2 induction at any site. These data address the mechanisms driving constitutive COX-2 and suggest that by targeting transcription it may be possible to develop antiinflammatory therapies that spare the constitutive expression necessary for normal homeostatic functions, including those important to the cardiovascular-renal system

Northern areas as refugia for temperate species under current climate warming: Atlantic salmon (Salmo salar L.) as a model in Northern Europe

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordIn this work, patterns of geographical genetic diversity in Atlantic salmon Salmo salar were studied across the whole Atlantic arc, as well as whether patterns (and thus genetic population structure) were affected by water temperatures. Salmo salar populations were here characterized using microsatellite loci and then analysed in the light of ocean surface temperature data from across the region. Analysis showed the presence of a latitudinal cline of genetic variability (higher in northern areas) and water temperatures (sea surface temperatures) determining genetic population structure (the latter in combination with genetic drift in southern populations). Under the current global change scenario, northern areas of Europe would constitute refuges for diversity in the future. This is effectively the inverse of what appears to have happened in glacial refugia during the last glacial maximum. From this perspective, the still abundant and large northern populations should be considered as precious as the small almost relict southern ones and perhaps protected. Careful management of the species, coordinated across countries and latitudes, is needed in order to avoid its extinction in Europe.J. L. Horreo was supported by a MINECO Spanish postdoctoral grant (“Juan de la CiervaIncorporación” (ref. IJCI-2015-23618). This work was funded by the European Union INTERREG IIIB programme (Atlantic Salmon Arc Project [ASAP], Project No. 040 and ASAP-2, Project No. 203). This study received additional funding from the Principality of Asturias Grants for Excellent Research (GRUPIN-2014-093) and the Contract CN-14-076

Metabolic rate and hypoxia tolerance in Girardinichthys multiradiatus (Pisces: Goodeidae), an endemic fish at high altitude in tropical Mexico

Artículo científico JCR Q1The darkedged splitfin (Amarillo fish), Girardinichthys multiradiatus is a vulnerable endemic fish species inhabiting central Mexico's high altitude Upper Lerma Basin, where aquatic hypoxia is exacerbated by low barometric pressures (lower PO2s), large aquatic oxygen changes, poor aquatic systems management and urban, agricultural and industrial pollution. The respiratory physiology of G. multiradiatus under such challenging conditions is unknown - therefore the main goal of the present study was to determine metabolic rates and hypoxia tolerance to elucidate possible physiological adaptations allowing this fish to survive high altitude and increasingly eutrophic conditions. Fish came from two artificial reservoirs – San Elías and Ex Hacienda - considered refuges for this species. Both reservoirs showed high dial PO2 variation, with hypoxic conditions before midday and after 20:00 h, ~4 h of normoxia (15 kPa) from 16:00–20:00, and ~4 h of hyperoxia (16–33 kPa) from 12:00–16:00. Standard metabolic rate at 20 ± 0.5 °C of larvae from Ex Hacienda was significantly higher than those from San Elías, but these differences disappeared in juveniles and adults. Metabolic rate at 20 ± 0.5 °C for adults was 9.8 ± 0.1 SEM μmol O2/g/h. The metabolic scaling exponent for adults was 0.58 for San Elías fish and 0.83 for Ex Hacienda fish, indicating possible ecological effects on this variable. Post-larval fish in Ex Hacienda and all stages in San Elias site showed considerable hypoxia tolerance, with PCrit mean values ranging from 1.9–3.1 kPa, lower than those of many tropical fish at comparable temperatures. Collectively, these data indicate that G. multiradiatus is well adapted for the hypoxia associated with their high-altitude habitat.CONACyT PRODEP-SEP UAEMé

Memory consolidation in the cerebellar cortex

Several forms of learning, including classical conditioning of the eyeblink, depend upon the cerebellum. In examining mechanisms of eyeblink conditioning in rabbits, reversible inactivations of the control circuitry have begun to dissociate aspects of cerebellar cortical and nuclear function in memory consolidation. It was previously shown that post-training cerebellar cortical, but not nuclear, inactivations with the GABA(A) agonist muscimol prevented consolidation but these findings left open the question as to how final memory storage was partitioned across cortical and nuclear levels. Memory consolidation might be essentially cortical and directly disturbed by actions of the muscimol, or it might be nuclear, and sensitive to the raised excitability of the nuclear neurons following the loss of cortical inhibition. To resolve this question, we simultaneously inactivated cerebellar cortical lobule HVI and the anterior interpositus nucleus of rabbits during the post-training period, so protecting the nuclei from disinhibitory effects of cortical inactivation. Consolidation was impaired by these simultaneous inactivations. Because direct application of muscimol to the nuclei alone has no impact upon consolidation, we can conclude that post-training, consolidation processes and memory storage for eyeblink conditioning have critical cerebellar cortical components. The findings are consistent with a recent model that suggests the distribution of learning-related plasticity across cortical and nuclear levels is task-dependent. There can be transfer to nuclear or brainstem levels for control of high-frequency responses but learning with lower frequency response components, such as in eyeblink conditioning, remains mainly dependent upon cortical memory storage

Ultrasound erosions in the feet best predict progression to inflammatory arthritis in anti-CCP positive at-risk individuals without clinical synovitis

Objectives To investigate, in anti-cyclic citrullinated peptide antibody positive (CCP+) at-risk individuals without clinical synovitis, the prevalence and distribution of ultrasound (US) bone erosions (BE), their correlation with subclinical synovitis and their association with the development of inflammatory arthritis (IA). Methods Baseline US scans of 419 CCP+ at-risk individuals were analysed. BE were evaluated in the classical sites for rheumatoid arthritis damage: the second and fifth metacarpophalangeal (MCP2 and MCP5) joints, and the fifth metatarsophalangeal (MTP5) joints. US synovitis was defined as synovial hypertrophy (SH) ≥2 or SH ≥1+power Doppler signal ≥1. Subjects with ≥1 follow-up visit were included in the progression analysis (n=400). Results BE were found in ≥1 joint in 41/419 subjects (9.8%), and in 55/2514 joints (2.2%). The prevalence of BE was significantly higher in the MTP5 joints than in the MCP joints (p1 joint 10.6 (95% CI 1.9 to 60.4, p<0.01) and BE and synovitis in ≥1 MTP5 joint 5.1 (95% CI 1.4 to 18.9, p=0.02). In high titre CCP+ at-risk individuals, with positive rheumatoid factor and BE in ≥1 joint, the OR increased to 16.9 (95% CI 2.1–132.8, p<0.01). Conclusions In CCP+ at-risk individuals, BE in the feet appear to precede the onset of clinical synovitis. BE in >1 joint, and BE in combination with US synovitis in the MTP5 joints, are the most predictive for the development of clinical arthritis