Leslie Armour argues for the rules of a dialectical logic which can account for the metaphysical problems of stability and change. He proposes a specific/general exclusion reference, a variation of the polar opposites contrast, which will make possible a rigorous development of the core structural concepts necessary for systematic explanation. His initial move is significantly different from Hegel’s being-nothing-becoming triad. The opposite of "pure being," Armour contends, is "pure disjunction." "Being" unifies, "disjunction" makes distinctions possible. Seven more categories are developed, (...) each at lower levels of abstraction, to introduce actual specificity and change. Armour’s main contention is that Hegel erred in introducing concrete "becoming" at a high level of logical abstraction. The ordering of his concepts is straightforward. "Pure being" contrasted with "pure disjunction" necessitates "determinate being." "Systematic unity" unifies the opposing elements in and. "Pure process" establishes the possibility of ongoing experience. Particularity is accounted for by the concepts of "determinate process" instantiated in the contrast of "ideal" and "objective universality" realized in the "dialectical individual." The final concept maintains the tension between structure and actualization without resulting in mere vacillation. This is done by arguing that self-identity is not a matter of bodily and dispositional consistency, but, rather, the pursuit of reasonableness. Armour contends that we identify people by the coherence of their actions which is understood in the context of an overall structure, such as the one he proposes. Some will be bothered by Armour’s admission that the development of the concepts of specificity cannot exemplify the necessity of the more general initial dialectical concepts. Others will be attracted to the degree of freedom for the subject in his concept of individuality which is supported by a clear systematic account.—P. G. W. S. (shrink)

Progressive supranuclear palsy is a movement disorder with prominent tau neuropathology. Brain diseases with abnormal tau deposits are called tauopathies, the most common of which is Alzheimer's disease. Environmental causes of tauopathies include repetitive head trauma associated with some sports. To identify common genetic variation contributing to risk for tauopathies, we carried out a genome-wide association study of 1,114 individuals with PSP and 3,247 controls followed by a second stage in which we genotyped 1,051 cases and 3,560 controls for the (...) stage 1 SNPs that yielded P ≤ 10-3. We found significant previously unidentified signals associated with PSP risk at STX6, EIF2AK3 and MOBP. We confirmed two independent variants in MAPT affecting risk for PSP, one of which influences MAPT brain expression. The genes implicated encode proteins for vesicle-membrane fusion at the Golgi-endosomal interface, for the endoplasmic reticulum unfolded protein response and for a myelin structural component. © 2011 Nature America, Inc. All rights reserved. (shrink)

Microbiologists are transitioning from the study and characterization of individual strains or species to the profiling of whole microbiomes and microbial ecology. Equipped with high-throughput methods for studying the taxonomic and functional characteristics of diverse samples, they are just beginning to encounter the conceptual, theoretical, and experimental problems of comparing taxonomy to function, and extracting useful measures from such comparisons. Although still unresolved, these problems are well studied in macro-ecology and are reiterated here as an historical precautionary for microbial ecologists. (...) Beyond expected and unresolved terminological vagueness, we argue that assessments and comparisons of taxonomic and functional profiles in micro-ecology suffer from theoretically unresolvable arbitrariness and ambiguities. We divide these into problems of scale, individuation, and commensurability. We argue that there is no technically/theoretically “correct” scale, individuation, or comparison of taxonomy and function, but there are nonetheless better and worse methodologies for profiling. (shrink)

In a recent paper Robert J. Richman joins a host of doubters who question Gettier's claim that knowledge is not justified true belief. Richman's scepticism of Gettier's counterexamples to the traditional analysis of knowledge stems from what he says are two basic defects in the examples. One defect is that Gettier employs the Principle of Deducibility for Justification which Richman argues is false. The second defect is based on “the obvious consideration that a belief which is justified on the basis (...) of one set of facts or assumptions need not be justified on the basis of a different set.” I shall consider each of these alleged defects and argue that Richman has not shown that in fact they are defects and that Gettier's counterexamples do in fact show that knowledge is not justified true belief.The Principle of Deducibility for Justification states that for any proposition P, if P entails Q and S correctly deduces Q from P and accepts Q as a result of this deduction, then Sis justified in believing Q. (shrink)

We apply an online optimization process based on machine learning to the production of Bose-Einstein condensates. BEC is typically created with an exponential evaporation ramp that is optimal for ergodic dynamics with two-body s-wave interactions and no other loss rates, but likely sub-optimal for real experiments. Through repeated machine-controlled scientific experimentation and observations our ’learner’ discovers an optimal evaporation ramp for BEC production. In contrast to previous work, our learner uses a Gaussian process to develop a statistical model of the (...) relationship between the parameters it controls and the quality of the BEC produced. We demonstrate that the Gaussian process machine learner is able to discover a ramp that produces high quality BECs in 10 times fewer iterations than a previously used online optimization technique. Furthermore, we show the internal model developed can be used to determine which parameters are essential in BEC creation and which are unimportant, providing insight into the optimization process of the system. (shrink)

Using covariant derivatives and the operator definitions of quantum mechanics, gauge invariant Proca and Lehnert equations are derived and the Lorenz condition is eliminated in U(1) invariant electrodynamics. It is shown that the structure of the gauge invariant Lehnert equation is the same in an O(3) invariant theory of electrodynamics.

Governments must keep agricultural systems free of pests that threaten agricultural production and international trade. Biosecurity surveillance already makes use of a wide range of technologies, such as insect traps and lures, geographic information systems, and diagnostic biochemical tests. The rise of cheap and usable surveillance technologies such as remotely piloted aircraft systems presents value conflicts not addressed in international biosurveillance guidelines. The costs of keeping agriculture pest-free include privacy violations and reduced autonomy for farmers. We argue that physical and (...) digital privacy in the age of ubiquitous aerial and ground surveillance is a natural right to allow people to function freely on their land. Surveillance methods must be co-created and justified through using ethically defensible processes such as discourse theory, value-centred design and responsible innovation to forge a cooperative social contract between diverse stakeholders. We propose an ethical framework for biosurveillance activities that balances the collective benefits for food security with individual privacy: establish the boundaries of a biosurveillance social contract; justify surveillance operations for the farmers, researchers, industry, the public and regulators; give decision makers a reasonable measure of control over their personal and agricultural data; and choose surveillance methodologies that give the appropriate information. The benefits of incorporating an ethical framework for responsible biosurveillance innovation include increased participation and accumulated trust over time. Long term trust and cooperation will support food security, producing higher quality data overall and mitigating against anticipated information gaps that may emerge due to disrespecting landholder rights. (shrink)

The 3Rs, or the replacement, reduction, and refinement of animal research, are widely accepted as the best approach to maximizing high-quality science while ensuring the highest standard of ethical consideration is applied in regulating the use of animals in scientific procedures. This contrasts with the muted scientific interest in the 3Rs when they were first proposed in The Principles of Humane Experimental Technique. Indeed, the relative success of the 3Rs has done little to encourage engagement with their original text, which (...) remains little read and out of print. By adopting a historical perspective, this article argues that one explanation for this disjunction may be found in another, more celebrated, event of 1959: C. P. Snow’s Rede lecture on The Two Cultures. The moral outlook of The Principles of Humane Experimental Technique derived from an earlier ethos wherein humanistic and scientific values occupied a shared culture. While the synthetic style of The Principles has hindered its readership, this article concludes that there is value to recovering the notion that the humanities and social sciences can contribute to the improvement of animal research. (shrink)

We propose a model mechanism for the initiation and spatial positioning of teeth primordia in the alligator, Alligator mississippiensis. Detailed embryological studies by Westergaard and Ferguson have shown that jaw growth plays a crucial role in the developmental patterning of the tooth initiation process. Based on biological data we develop a dynamic patterning mechanism, which crucially includes domain growth. The mechanism can reproduce the spatial pattern development of the first seven teeth primordia in each half jaw of A. mississippiensis. The (...) results for the precise spatio-temporal sequence compare well with experiment. Simulation of the model also predicts that certain transplantations can alter the spatial sequence of teeth primordia initiation. (shrink)

In his discussion of Roman military institutions Polybius described how the desire for fame might inspire Roman soldiers to heroic feats of bravery, including single combat: τ δ μέγιστον, ο νέοι παρορμνται πρς τ πν πομένειν πρ τν κοινν πραγμάτων χάριν το τυχεν τς συνακολουθούσης τος γαθος τν νδρν εκλείας. πίστιν δ' χει τ λεγόμενον κ τούτων. πολλο μν γρ μονο-μάχησαν κουσίως ωμαίων πρ τς τν λων κρίσεως κτλ. Modern scholars, however, have taken little notice of this remark and some (...) have tried to belittle the importance of single combat at Rome. Thus G. Dumézil alleged that the Romans fought few single combats and that this was significant for their outlook upon war, while R. Bloch described the duels in the seventh book of Livy as ‘un mode de combat absolument étranger à la tradition romaine, mail auquel les Romains ont été contraints par les habitudes et par les défis des Celtes’. W. V. Harris is the only scholar to have understood the importance of monomachy in the Roman Republic, but even he has not assembled all the evidence necessary for an accurate assessment of the phenomenon. This essay is intended to provide a full treatment and thus to make some contribution in a limited but interesting area to our understanding of Roman attitudes to warfare. I have included a list and discussion of all instances of single combat from the Roman Republic which I have discovered and have argued that the custom continued from prehistoric times at least to 45 b.c. (shrink)

Nucleation and motion of kink pairs on partial dislocations are examined by elasticity theory for materials with a high Peierls stress. Two approaches are used: one considers the change in average stacking-fault energy due to alloying elements and the other considers the change in local SFE due to a nearby solute atom. Both approaches highlight the role of SFE on kink nucleation, propagation and annihilation and both furnish strain rate as a function of stress, temperature and SFE. Model predictions are (...) compared with yield stress data for two systems: firstly, an intermetallic, MoSi 2 , which softens for alloying elements that decrease the SFE and hardens for Re additions that increase the SFE; secondly, a ceramic oxide, MgO-Al 2 O 3 spinel, which softens with increasing addition of excess alumina and at the same time exhibits a decrease in SFE. The average SFE approach agrees qualitatively with the data while quantitative agreement is obtained with the local SFE approach. The possibility is considered that the model applies to other materials, such as TiAl, HfV 2 and Fe 3 Al, which show softening with certain alloying additions. One requirement is that the dislocations are dissociated more than a few atomic distances; otherwise kink nucleation occurs on the perfect dislocation . Hence the model does not apply to materials such as bcc metals which only have a core dissociation. Normal hardening effects of solutes from size and modulus misfits are additive with any softening effects from a decrease in SFE and so may mask the latter, as occurs for W additions to MoSi 2. (shrink)

Early versions of satellite and radiosonde datasets suggested that the tropical surface had warmed more than the troposphere, while climate models consistently showed tropospheric amplification of surface warming in response to human-caused increases in greenhouse gases. We revisit such comparisons here using new observational estimates of surface and tropospheric temperature changes. We find that there is no longer a serious discrepancy between modeled and observed trends in the tropics. Our results contradict a recent claim that all simulated temperature trends in (...) the tropical troposphere are inconsistent with observations. This claim was based on the use of older radiosonde and satellite datasets and on two methodological errors: the neglect of observational trend uncertainties introduced by interannual climate variability and application of an inappropriate statistical “consistency test”.This emerging reconciliation of models and observations has two primary explanations. First, because of changes in the treatment of buoy and satellite information, new surface temperature datasets yield slightly reduced tropical warming relative to earlier versions. Second, recently developed satellite and radiosonde datasets now show larger warming of the tropical lower troposphere. In the case of a new satellite dataset from remote sensing systems, enhancedRSS warming is due to an improved procedure of adjusting for inter-satellite biases. When the RSS-derived tropospheric temperature trend is compared with four different observed estimates of surface temperature change, the surface warming is invariably amplified in the tropical troposphere, consistent with model results. Even if we use data from a second satellite dataset with smaller tropospheric warming than in remote sensing systems RSS, observed tropical lapse rates are not significantly different from those in all model simulations.Our results contradict a recent claim that all simulated temperature trends in the tropical troposphere and in tropical lapse rates are inconsistent with observations. This claim was based on the use of older radiosonde and satellite datasets and on two methodological errors: the neglect of observational trend uncertainties introduced by interannual climate variability and application of an inappropriate statistical “consistency test”. (shrink)