Agrippa's trilemma: scepticism and contemporary epistemology

Take any belief of yours – even one about which you feel supremely confident. The Sceptic will ask: why do you think it is true? You might take yourself to have a very good reason to believe what you do. But the sceptic will also want to know why you think that this second thing is true as well. You might offer yet a third reason for believing that, but the sceptic won't stop. He will want, again, to know why you believe that third thing. How will you choose to answer the sceptic's constant questioning? You might just keep going on, offering yet more and more reasons every time the sceptic questions you. Or you might argue in a circle, so that you defend your original belief by an argument which eventually appeals again to that very belief. Or you might argue that your original belief can eventually be defended by appeal to a set of assumptions for which you do not have any further reasons. But are any of those options really acceptable, or should you give up your original belief? If the latter, then since the sceptic could question any of your beliefs in this way, does that mean that you should give up all of your beliefs? Are you open to blame and criticism just for believing anything at all? The Pyrrhonian sceptic tries to convince us that the answers to these questions are “yes”. In this work, I explicate the sceptical strategy in detail and consider philosophical attempts to evade its dire conclusion. My development of Scepticism draws on the ideas of Sextus and three of his scholars, Barnes, Bailey and Machuca, as well as BonJour and Oakley. A number of philosophers have criticized Scepticism on the grounds that it presupposes a nonordinary definition of “knowledge”. The sceptic tries to show that our common-sense belief that we know all sorts of things about the world is really a giant error, but the only way he manages to do it, according to these philosophers, is by starting with a definition of “knowledge” vastly removed from our usual one. This strategy is the dominant way of criticizing Scepticism in contemporary epistemology. It is deployed by John Greco, Alvin Goldman, Mark Kaplan and many others. Against these philosophers, I urge that the sceptic's using the word “know” in a non-ordinary way does not harm the substance of his arguments at all. A number of philosophers have argued that the sceptic's standards for right or justified belief should be rejected. I argue that the standard which the Pyrrhonian lays down is not at all ridiculous. All he asks of us is that we have some reason, no matter how weak, for believing that P rather than -P – a reason which might convince someone who did not already believe that P. And so the sceptic lays down a standard which it may be very difficult to give up. What's more, I argue, by discussing the views of Michael Williams and Michael Huemer, that it is far from clear that there is anything in the neighbourhood that is particularly plausible as an ethics of belief. These two broad anti-sceptical gambits are the currently dominant ones. In showing them to be unsatisfactory, I show that the sceptic still has us firmly in his net

New production methods for salient pole rotor manufacture

The current design for a salient pole rotor consists of hundreds of laminations joined together to form a core pack, which is then pressed onto shaft. This thesis examines the possibility of using a solid cast rotor to reduce the complexity of rotor construction. To produce a solid salient pole rotor that has the capability to match the performance of the current lamination based rotor three fundamental areas which affect rotor performance were investigated. They are: • The magnetic performance of cast steel and a lower saturation Fe-Ni alloy for the magnetic shielding of pole faces. • The comparison of the performance of a solid steel rotor verses the lamination based rotor. • The use of laser cladding to produce a soft magnetic coating to prevent eddy currents from being induced into the rotor. Samples of cast steel were tested after various heat treatments were applied and their DC B-H curves were measured. The samples were examined, via optical microscopy, to determine the effect of heat treatments on their microstructure. The changes in their B-H curves and permeability were linked to the changes in microstructure by examination of the optical images. A prototype of a solid rotor was produced to determine its performance compared with the lamination based rotor. The prototype rotor was produced with a Fe-Ni alloy on the rotor pole faces. The prototype rotor was found to require an average of 72% more power in the field windings to match the performance of the lamination based rotor. This was true until the generator’s output reached 72kW when the Fe-Ni alloy on the rotor pole faces saturated, resulting in the air gap between the rotor and stator increasing from 2mm to 34.5mm. After the increase in air gap the prototype rotor required an average of 188% more power to match the lamination based rotor. The point at which the Fe-Ni alloy saturates is critical, as once saturated the power in the field windings must increase sharply to bridge the larger air gap. From this work it is clear that a cast steel with a better magnetic performance is required and that the point at which the lower saturation material on the pole shoes saturates needs to more closely match the normal operating power of the generator. Laser cladding was used to produce a coating that can be applied to the pole faces, with a sufficient thickness to allow a controllable increase in the air gap between the rotor and the stator at predetermined field strengths. The use of laser cladding in this way enables the pole face to act as a magnetic shield stopping heating in the rotor due to induced eddy currents. The use of annealing in both inert and reactive atmospheres was examined to determine their effect on the DC magnetic properties of the deposited coating. Annealing in an inert atmosphere of argon was found to improve the saturation magnetisation of the coating 30% better than annealing in a reactive hydrogen atmosphere

Blood Vessels Under the Microscope

This paper looks at blood vessels. All humans and animals have blood vessels, including your pet rabbit or dog, a whale or a giraffe! We need blood vessels to stay alive. This paper answers many questions, including what blood vessels are used for and why we need them. It looks at how and why blood vessels grow and what they look like. It also explores what happens when things go wrong with blood vessels and if blood vessels are ever bad for us. So, if you want to know how many miles of blood vessels there are in your body, learn about problems astronauts have in space, see real blood vessels through a microscope, or learn how to keep your blood vessels healthy, you are reading the right article

Synthetic and mechanistic aspects of sulfonyl migrations

Over the past 20 years reports of sulfonyl migrations have appeared, frequently described as ‘unusual’ and ‘unexpected’. This comprehensive review compiles, for the first time, sulfonyl migrations reported over the last 20 years including formal 1,2-, 1,3-, 1,4-, 1,5-, 1,6- and 1,7-sulfonyl shifts, occurring through either radical or polar processes, either inter- or intramolecularly. Discussion of the sulfonyl migrations is structured according to reaction type, i.e. nitrogen–carbon, nitrogen–oxygen, nitrogen–nitrogen, oxygen–carbon (including anionic and non-anionic thia-Fries rearrangements), oxygen–oxygen and carbon–carbon migrations. Discussion of the underlying mechanisms for the migrations is included, with particular attention afforded to the principal techniques utilised for their elucidation, namely isotopic-labelling, crossover experiments, density functional theory calculations and electron paramagnetic resonance spectroscopy amongst others

NUCB2/Nesfatin-1 Reduces Obesogenic Diet Induced Inflammation in Mice Subcutaneous White Adipose Tissue

Background: Excess adipose tissue accumulation and obesity are characterised by chronic, low-grade, systemic inflammation. Nestfatin-1 is a neuropeptide derived from the precursor protein nucleobindin-2 (NUCB2), which was initially reported to exert anorexigenic effects. The present study aimed to investigate the effects of an obesogenic diet (OD; high-fat, high-sugar) in NUCB2 knockout (KO) mice and of nesfatin-1 treatment in LPS-stimulated 3T3-L1 preadipocytes. Methods: Subcutaneous white adipose tissue (Sc-WAT) samples from wild type (WT) and NUCB2 KO mice that were fed a normal diet (ND), or the OD for 12 weeks were used for RNA and protein extraction, as well as immunohistochemistry. 3T3-L1 cells were treated with 100 nM nesfatin-1 during differentiation and stimulated with 1 µg/mL LPS for measuring the expression and secretion of pro-inflammatory mediators by qPCR, western blotting, immunofluorescence, Bioplex, and ELISA. Results: Following the OD, the mRNA, protein and cellular expression of pro-inflammatory mediators (Tnfα, Il-6, Il-1β, Adgre1, Mcp1, TLR4, Hmbgb1 and NF-kB) significantly increased in the ScWAT of NUCB2 KO mice compared to ND controls. Adiponectin and Nrf2 expression significantly decreased in the ScWAT of OD-fed NUCB2 KO, without changes in the OD-fed WT mice. Furthermore, nesfatin-1 treatment in LPS-stimulated 3T3-L1 cells significantly reduced the expression and secretion of pro-inflammatory cytokines (Tnfα, Il-6, Il-1β, Mcp1) and hmgb1. Conclusion: An obesogenic diet can induce significant inflammation in the ScWAT of NUCB2 KO mice, involving the HMGB1, NRF2 and NF-kB pathways, while nesfatin-1 reduces the pro-inflammatory response in LPS-stimulated 3T3-L1 cells. These findings provide a novel insight into the metabolic regulation of inflammation in WAT

Knockdown of embryonic myosin heavy chain reveals an essential role in the morphology and function of the developing heart

The expression and function of embryonic myosin heavy chain (eMYH) has not been investigated within the early developing heart. This is despite the knowledge that other structural proteins, such as alpha and beta myosin heavy chains and cardiac alpha actin, play crucial roles in atrial septal development and cardiac function. Most cases of atrial septal defects and cardiomyopathy are not associated with a known causative gene, suggesting that further analysis into candidate genes is required. Expression studies localised eMYH in the developing chick heart. eMYH knockdown was achieved using morpholinos in a temporal manner and functional studies were carried out using electrical and calcium signalling methodologies. Knockdown in the early embryo led to abnormal atrial septal development and heart enlargement. Intriguingly, action potentials of the eMYH knockdown hearts were abnormal in comparison with the alpha and beta myosin heavy chain knockdowns and controls. Although myofibrillogenesis appeared normal, in knockdown hearts the tissue integrity was affected owing to apparent focal points of myocyte loss and an increase in cell death. An expression profile of human skeletal myosin heavy chain genes suggests that human myosin heavy chain 3 is the functional homologue of the chick eMYH gene. These data provide compelling evidence that eMYH plays a crucial role in important processes in the early developing heart and, hence, is a candidate causative gene for atrial septal defects and cardiomyopathy

Serum ceruloplasmin and the risk of cancer in Finland.

The relationship between serum ceruloplasmin level and cancer incidence was investigated in a case-control study nested within a longitudinal study of 39,268 Finns participating in the Social Insurance Institution's Mobile Clinic Health Examination Survey carried out in 1968-1972. During a median follow-up of 8 years, 766 cancer cases were identified. Ceruloplasmin levels were determined from stored serum samples collected at the baseline from these cancer cases and from two matched controls per case. The overall incidence of cancer was positively associated with serum ceruloplasmin level. The association was strongest for lung cancer and other cancers related to smoking and, consequently, in males. The smoking-adjusted relative risk of lung cancer among men was 4.3 (95% confidence interval (CI) = 1.8-10.6) in the highest quintile of serum ceruloplasmin as compared with that in the lowest quintile. The corresponding relative risks for cancers related to smoking combined, and for cancers not related to smoking were 3.9 (CI = 1.9-8.4) and 0.9 (CI = 0.6-1.5), respectively. The elevated risk of lung cancer at high concentrations of serum ceruloplasmin persisted after further adjustment for several potential confounding factors such as serum levels of vitamins A and E and selenium. The risk was stronger during the first 6 years of follow-up than later, and strongest during the first 2 years. The most likely explanation of the present results thus is that high serum ceruloplasmin levels in lung cancer are mainly due to occult cancer

Inhibición del bronceado en cáscara de chirimoya ‘Fino de Jete’ por aplicación de 6-bencilaminopurina

The cherimoya (Annona cherimola Mill.) fruit is climacteric and has a very short postharvest life; the symptoms of senescence include peel browning and fruit softening. The objective of this research was to evaluate the effect of application of 6-benzylaminopurine (BAP) in the postharvest life of cherimoya fruit ‘Fino de Jete’. Fruits were randomly selected from the middle and basal part of six trees. BAP was applied at 1.0 mM or 0 mM in every of two dates, that is 8 or 15 days before harvest (DAC). After harvest, fruits were transported for 1.5 h and stored in two different temperatures, refrigerated (TR) (6 °C) or room temperature (TA) (16 ± 2 °C). Every third day, from 1 to 15 day after harvest (DDC), they were analyzed in relation to weight loss, color L*, a* and b*, and fruit firmness and deformation. In TA, the fruits treated with 1 mM BAP in both, 8 or 15 DAC retained peel color L* over 35% (ρ ≤ 0.05) in relation to control.La chirimoya (Annona cherimola Mill.) es climatérica, su vida poscosecha se acorta por el bronceado de cáscara y ablandamiento del fruto. El objetivo de esta investigación fue evaluar el efecto poscosecha de la aplicación de 6-bencilaminopurina (BAP) en chirimoya ‘Fino de Jete’. Los frutos se seleccionaron aleatoriamente de la parte media y basal de la copa de seis árboles y se les aplicó 1,0 mM o 0 mM BAP. Los frutos permanecieron en el árbol 8 y 15 días después de la aplicación; después de la cosecha se transportaron por 1,5 h y se almacenaron en refrigeración (TR) (6 °C) o temperatura ambiente (TA) (16 ± 2 °C). A partir de 1 y hasta 15 días después de cosecha (DDC), cada tercer día se analizó pérdida de peso, color L*, a* y b*, firmeza y deformación de fruto. Después de 15 días de almacenamiento a TA, 1 mM BAP aplicado en cualquier fecha redujo el oscurecimiento poscosecha de la cáscara, conservando el color L* más de 35% en relación al control (ρ ≤ 0,05)

Controlling DC permeability in cast steels

Annealing (at multiple cooling rates) and quenching (with tempering) was performed on specimens of cast steel of varying composition. The aim was to devise a method for selecting the steel with the highest permeability, from any given range of steels, and then increasing the permeability by heat treatment. Metallographic samples were imaged using optical microscopy to show the effect of the applied heat treatments on the microstructure. Commonly cast steels can have DC permeability altered by the careful selection of a heat treatment. Increases of up to 381% were achieved by annealing using a cooling rate of 6.0 °C/min. Annealing was found to cause the carbon present in the steel to migrate from grain boundaries and from within ferrite crystals into adjacent pearlite crystals. The migration of the carbon resulted in less carbon at grain boundaries and within ferrite crystals reducing the number of pinning sites between magnetic domains. This gives rise to a higher permeability. Quenching then tempering was found to cause the formation of small ferrite crystals with the carbon content of the steel predominately held in the martensitic crystal structures. The results show that with any given range of steel compositions the highest baseline DC permeability will be found with the steel that has the highest iron content and the lowest carbon content. For the samples tested in this paper a cooling rate of 4.5 °C/min resulted in the relative permeability of the sample with the highest baseline permeability, AS4, increasing from 783 to 1479 at 0.5 T. This paper shows how heat treatments commonly applied to hypoeutectoid cast steels, to improve their mechanical performance, can be used to also enhance electromagnetic properties of these alloys. The use of cast steels allows the creation of DC components for electrical machines not possible by the widely used method of stacking of electrical grade sheet steels