Arbuscular mycorrhizal fungi are considered as a potential biotechnological tool for improving phytostabilization efficiency and plant tolerance to heavy metal-contaminated soils. However, the mechanisms through which AMF help to alleviate metal toxicity in plants are still poorly understood. A greenhouse experiment was conducted to evaluate the effects of two AMF species on the growth, Pb accumulation, photosynthesis and antioxidant enzyme activities of a leguminous tree at Pb addition levels of 0, 500, 1000 and 2000 mg kg-1 soil. AMF symbiosis decreased (...) Pb concentrations in the leaves and promoted the accumulation of biomass as well as photosynthetic pigment contents. Mycorrhizal plants had higher gas exchange capacity, non-photochemistry efficiency, and photochemistry efficiency compared with non-mycorrhizal plants. The enzymatic activities of superoxide dismutase, ascorbate peroxidases and glutathione peroxidase were enhanced, and hydrogen peroxide and malondialdehyde contents were reduced in mycorrhizal plants. These findings suggested that AMF symbiosis could protect plants by alleviating cellular oxidative damage in response to Pb stress. Furthermore, mycorrhizal dependency on plants increased with increasing Pb stress levels, indicating that AMF inoculation likely played a more important role in plant Pb tolerance in heavily contaminated soils. Overall, both F. mosseae and R. intraradices were able to maintain efficient symbiosis with R. pseudoacacia in Pb polluted soils. AMF symbiosis can improve photosynthesis and reactive oxygen species scavenging capabilities and decrease Pb concentrations in leaves to alleviate Pb toxicity in R. pseudoacacia. Our results suggest that the application of the two AMF species associated with R. pseudoacacia could be a promising strategy for enhancing the phytostabilization efficiency of Pb contaminated soils. (shrink)

A critical review of gravitational wave theory is made. It is pointed out that the usual linear approach to the gravitational wave theory is neither conceptually consistent nor mathematically justified. Relying upon that analysis it is argued that—analogously to a Yang-Mills propagating field, which must be nonlinear to carry its gauge charge—a gravitational wave must necessarily be nonlinear to transport its own charge—that is, energy-momentum.

A report by the Nuffield Council on Bioethics, contrary to the Declaration of Helsinki, permits most important research initiatives in developing countries.The Ethics of Research Related to Health Care in Developing Countries by the Nuffield Council on Bioethics makes a number of innovative recommendations that depart from codes such as the Declaration of Helsinki. It recommends that standards of care might be relativised to the standard of that nation. It recommends that very good reasons need to be given for not (...) giving post-trial access to medications but recognises that there may be justifiable instances of this. It is the view of the authors that these and other recommendations of the report are sensible pieces of advice given the complexities of the developing world. (shrink)

In his illuminating discussion of ‘the Caspian question’ Sir William Tarn, basing his case mainly on Aristotle, Meteorologica, 2. 1. 10 and Strabo, 11. 7. 4, argued that Alexander knew of the existence of the Aral Sea. Tarn's conclusion, however, was soon challenged by Professor Lionel Pearson, who disagreed in particular with Tarn's interpretation of the passage in Strabo. But, although he undoubtedly succeeds in showing that some of Tarn's arguments are not valid, Pearson fails, as it seems to me, (...) to disprove his main contention. Indeed, Pearson misunderstands the line of Strabo's argument and is led to propose an unnecessary emendation of the text. (shrink)

In his illuminating discussion of ‘the Caspian question’ Sir William Tarn, basing his case mainly on Aristotle, Meteorologica, 2. 1. 10 and Strabo, 11. 7. 4, argued that Alexander knew of the existence of the Aral Sea. Tarn's conclusion, however, was soon challenged by Professor Lionel Pearson, who disagreed in particular with Tarn's interpretation of the passage in Strabo. But, although he undoubtedly succeeds in showing that some of Tarn's arguments are not valid, Pearson fails, as it seems to me, (...) to disprove his main contention. Indeed, Pearson misunderstands the line of Strabo's argument and is led to propose an unnecessary emendation of the text. (shrink)

The purpose of this note is to defend the following reading, offered by a minority of manuscripts, at Sat. 6.6. Even if the evidence of the manuscripts showed merely that egregius… senes was an eleventh-century conjecture which gained a very moderate degree of acceptance, the reading would still have much to commend it.

This article studies a series of provocative references to Spinoza by Jacques Derrida and Giorgio Agamben. For both contemporary philosophers, the context is discussions of eating, a subject matter that turns out to involve such central issues as subjectivity, nature, ethics, and teleology. Each situates Spinoza in a counter-history of philosophy and suggests that Spinoza constitutes an important resource for contemporary reflections. Through an analysis of the three philosophers' texts about eating, nutrition, and being metabolized, I argue that Spinoza's nonteleological, (...) nonhumanistic conception of nature remains a radical possibility, even in the face of contemporary attempts to think outside the canonical discourses of transcendental subjectivity, technological reason, and teleological ethics. Spinoza's position is, in the end, more uncompromising than that of Derrida or Agamben. (shrink)

It seems to me certain that the perception of foreign bodies of a certain sort, although a necessary, is not the only, part of the basis of our belief in other persons. The greatest disagreement with this view that I know of has been expressed by Professor Aaron in a paper published in Philosophy , XIX, 72. He claims that, since one does not really know “what it means to be a mind in one's own case,” the question whether we (...) can be certain that there are other minds is meaningless except as reducible to the question whether such propositions as “Robinson exists” are propositions which we can be certain about. And he tries to show that no more is involved in the analysis of “Robinson exists” than would be involved in the analysis of propositions of whose truth we can be perceptually certain, such as “That table over there exists” or “The Eiffel Tower exists.” My assurance that Robinson exists is not the assurance that something called Robinson's mind exists. It is the perfectly ordinary perceptual assurance that ‘the person over there’ exists. “You ask me how I am certain that Robinson exists and I answer, ‘Well, look, there he is.’ It would be absurd for anyone to say that he does not exist when I see him here before me and hear him talk and watch him move that chair.”. (shrink)

There are many challenges to be met when writing an introductory treatise on an academic topic. The subject matter must be presented in a simple but not oversimplified manner. Enough theory must be included to ground the discussion of specific issues but not so much as to overwhelm or bore the readers. The text should be long enough to do justice to the subject matter but short enough to be readily accessible, especially for readers such as healthcare professionals, whose primary (...) concerns lie elsewhere.There are additional challenges in a relatively novel interdisciplinary field such as bioethics. The scope and methodology of bioethics are matters of great controversy, as are its relations with related subjects such as professionalism and human rights. The field is so broad that a single author cannot claim expertise on all topics. Rivalries between law and ethics and among medicine, other health professions, and disciplines such as philosophy complicate efforts to produce a broadly acceptable text. Finally, national and cultural differences pose major challenges to anyone trying to write for a truly international readership.The difficulty of meeting all these challenges in producing the WMA Medical Ethics Manual provides ample opportunity for criticism, especially from bioethics experts. The three expert reviewers of the manual in this issue of the journal are remarkably restrained in pointing out its shortcomings.1–3 I am grateful for both their positive evaluations and their constructive criticism. In what follows, I will respond to each of them in turn, focusing in particular on their suggestions as to how the Manual could have been improved.Before addressing these suggestions, I wish to clarify a matter raised by Søren Holm, namely, to what degree the manual …. (shrink)

On April 26, 1995, the United States Supreme Court limited the reach of the preemption provision of ERISA in New York State Conference of Blue Cross & Blue Shield Plans v. Tavelers Insurance Co. ). In Travelers, the Supreme Court upheld the validity of a New York statute requiring hospitals to collect surcharges from patients covered by commercial insurers and requiring health maintenance organizations to pay a surcharge to the state's general fund that varies depending on the number of Medicaid-eligible (...) HMO members enrolled. Neither patients insured by Blue Cross/Blue Shield plans nor the plans themselves are similarly charged under the statute. Several commercial insurers and HMOs claimed the surcharges should be preempted under ERISA because they are levied on patients whose insurance or HMO membership premiums are purchased by an ERISA plan.The ERISA preemption clause means that federal regulation, or lack thereof, supersedes state regulation that is related to employee pension and benefit plans. This preemption clause prevents states from changing health care and benefit law for a significant portion of state residents. (shrink)