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.

IPCC SPECIAL REPORT ON CLIMATE CHANGE AND LAND (SRCCL) -/- Chapter 3: Climate Change and Land: An IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems.

Schnorr randomness is a notion of algorithmic randomness for real numbers closely related to Martin-Löf randomness. After its initial development in the 1970s the notion received considerably less attention than Martin-Löf randomness, but recently interest has increased in a range of randomness concepts. In this article, we explore the properties of Schnorr random reals, and in particular the c.e. Schnorr random reals. We show that there are c.e. reals that are Schnorr random but not Martin-Löf random, and provide a new (...) characterization of Schnorr random real numbers in terms of prefix-free machines. We prove that unlike Martin-Löf random c.e. reals, not all Schnorr random c.e. reals are Turing complete, though all are in high Turing degrees. We use the machine characterization to define a notion of "Schnorr reducibility" which allows us to calibrate the Schnorr complexity of reals. We define the class of "Schnorr trivial" reals, which are ones whose initial segment complexity is identical with the computable reals, and demonstrate that this class has non-computable members. (shrink)

This essay, which is the editor's introduction to part 1 of a multipart symposium on quietism, also constitutes his call for symposium papers. The symposium is meant be comprehensive. It is described as political and broadly cultural as well as religious, and in religious terms is said to cover not only the Catholic and Protestant quietisms (most properly so called) of the late seventeenth and eighteenth centuries, but also the proto-quietisms of the medieval Western church and reputedly quietist aspects of (...) the Gnostic, Eastern Orthodox, early Hasidic, Shi'ite, Jain and other Indic, Taoist, and Zen religious traditions. This introduction emphasizes the secular approaches, mostly antipolitical or postphilosophical, that wear the adjective “quietist” metaphorically, including the postmodern currents that Martha Nussbaum has named “hip quietism” and the “minimalist” philosophical version developed by Wittgenstein and some of his successors, notably Richard Rorty. This introduction concludes with attention to Rorty's late essay “Naturalism and Quietism,” then with a dedication of the entire symposium to Rorty's memory. (shrink)

One third of the transcendental dialectic in Kant's Critique of Pure Reason is devoted to demolishing the pseudo-science of rational psychology. In this part of his work Kant attacks the idea that there is an ultimate subject of experience — the ‘I’ or Self — which can only be investigated and understood intellectually. The belief that such a study is possible is natural to human reason; but it is based on demonstrable error. Kant tries to exorcize our minds from falling (...) prey to this mistake. (shrink)

In debates over the regulation of communication related to dual-use research, the risks that such communication creates must be weighed against against the value of scientific autonomy. The censorship of such communication seems justifiable in certain cases, given the potentially catastrophic applications of some dual-use research. This conclusion however, gives rise to another kind of danger: that regulators will use overly simplistic cost-benefit analysis to rationalize excessive regulation of scientific research. In response to this, we show how institutional design principles (...) and normative frameworks from free speech theory can be used to help extend the argument for regulating dangerous dual-use research beyond overly simplistic cost-benefit reasoning, but without reverting to an implausibly absolutist view of scientific autonomy. (shrink)

In this article, we raise ethical concerns about the potential misuse of open-source biology : biological research and development that progresses through an organisational model of radical openness, deskilling, and innovation. We compare this organisational structure to that of the open-source software model, and detail salient ethical implications of this model. We demonstrate that OSB, in virtue of its commitment to openness, may be resistant to governance attempts.

There are good grounds for seeing a deep opposition between reason and violence. Yet some forms of argument appear to link the two; and a prominent example is the argumentum ad baculum, where the premise contains a threat. Consideration of the connection between premise and conclusion in such an argument can, it seems, yield some cases where the status of the author of the threat renders the argument not only valid but also sound. Examples of such arguments cluster in the (...) areas near Pascal's Wager and Rawls' argument for justice. However even these arguments fail to effect a reconciliation between reason and violence. (shrink)

I understand Pluralism to be the doctrine that, either generally or with reference to some particular area of judgement, there is more than one basic principle. It endorses the possibility that some particular case may arise which will be adjudicated in one way if one principle is applied while another principle points otherwise and to an answer which, at least in practice, is incompatible. Thus in morality, according to pluralism there may be more than one correct answer to the question (...) of which of the decisions available in some particular situation is the best. (shrink)

Ethics rounds in clinical ethics have already taken hold in multiple venues. There are “sit-down rounds,” which usually consist of a bioethicist setting a specific, prescheduled time aside for residents and/or others to bring a case or two for discussion with the bioethicist. Another kind of rounds that occurs on an ad hoc or infrequent basis is to have either a staff or outside bioethicist give hospital-wide and/or departmental “grand rounds.” Grand rounds is a traditional educational format in medicine and (...) adding bioethics to the topics covered in grand rounds is an important means of elevating ethical awareness within a department or throughout a healthcare organization. Newer is the rounding practice of adding a bioethicist to other established rounding processes, such as case management and utilization review rounds. All of these kinds of ethics rounds are important opportunities to elevate the level of moral discourse within a healthcare setting and are becoming part and parcel of any full-service hospital bioethics program. (shrink)

Scholars of classical philosophy have long disputed whether Aristotle was a dialectical thinker. Most agree that Aristotle contrasts dialectical reasoning with demonstrative reasoning, where the former reasons from generally accepted opinions and the latter reasons from the true and primary. Starting with a grasp on truth, demonstration never relinquishes it. Starting with opinion, how could dialectical reasoning ever reach truth, much less the truth about first principles? Is dialectic then an exercise that reiterates the prejudices of one's times and at (...) best allows one to persuade others by appealing to these prejudices, or is it the royal road to first principles and philosophical wisdom? In From Puzzles to Principles? May Sim gathers experts to argue both these positions and offer a variety of interpretive possibilities. The contributors' thoughtful reflections on the nature and limits of dialectic should play a crucial role in Aristotelian scholarship. (shrink)

Patients with apraxia perform poorly when demonstrating how an object is used, particularly when pantomiming the action. However, these patients are able to accurately identify, and to pick up and move objects, demonstrating intact ventral and dorsal stream visuomotor processing. Appropriate object manipulation for skilled use is thought to rely on integration of known and visible object properties associated with ‘ventro-dorsal’ stream neural processes. In apraxia, it has been suggested that stored object knowledge from the ventral stream may be less (...) readily available to incorporate into the action plan, leading to an over-reliance on the objects’ visual affordances in object-directed motor behaviour. The current study examined grasping performance in left hemisphere stroke patients with (N = 3) and without (N = 9) apraxia, and in age-matched healthy control participants (N = 14), where participants repeatedly grasped novel cylindrical objects of varying weight distribution. Across two conditions, object weight distribution was indicated by either a memory-associated cue (object colour) or visual-spatial cue (visible dot over the weighted end). Participants were required to incorporate object-weight associations to effectively grasp and balance each object. Control groups appropriately adjusted their grasp according to each object’s weight distribution across each condition, whereas throughout the task two of the three apraxic patients performed poorly on both the memory-associated and visual-spatial cue conditions. A third apraxic patient seemed to compensate for these difficulties but still performed differently to control groups. Patients with apraxia performed normally on the neutral control condition when grasping the evenly weighted version. The pattern of behaviour in apraxic patients suggests impaired integration of visible and known object properties attributed to the ventro-dorsal stream: in learning to grasp the weighted object accurately, apraxic patients applied neither pure knowledge-based information (the memory-associated condition) nor higher-level information given in the visual-spatial cue condition. Disruption to ventro-dorsal stream predicts that apraxic patients will have difficulty learning to manipulate new objects on the basis of information other than low-level visual cues such as shape and size. (shrink)