CORRECTION FACTORS FOR ‘BINDING’ STUDIES; MODEL SYSTEMS FOR GABA BINDING TO A SYNAPTOSOMAL–MITOCHONDRIAL FRACTION OF RAT CEREBRAL CORTEX1

Correction methods currently used in ‘binding’ experiments have been compared and a new approach is proposed. These methods have been applied to data on the ‘binding’ of GABA to a ‘synaptosomal-mitochondrial’ fraction of rat cerebral cortex under various conditions. Results indicated that values for ‘corrected binding’ can differ greatly, depending upon the method employed. Calculations based on data obtained when using a high concentration of unlabelled GABA to displace ‘specific’ binding of [³H]GABA (‘cold ligand method’) under-estimated the binding, because this method neglects the existence of a biochemically-inert space which exists within the pellet even at 0°C and which traps labelled ligand. The other correction method, in which an inert labelled substance (e.g. sucrose) is used to measure the portion of the pellet occupied by trapped supernatant fluid (‘sucrose space method’), is more accurate, but does not take into account the amount of ligand that may be non-specifically bound to the particulate portion of the pellet. The error with this method is small for ‘high-affinity’ ligand-receptor systems, but may be quite large for lower affinity systems. A method which takes into consideration both the inert space of the pellet and ligand that is non-specifically bound to the pellet (‘fully corrected method’) is proposed. The three correction methods have been applied to a study of the kinetic parameters of GABA binding to a ‘synaptosomal-mitochondrial’ fraction of rat cerebral cortex in the presence and absence of the GABA inhibitor, bicuculline-methiodide. In some cases, the results showed qualitative as well as large quantitative differences, depending on the correction method employed.     

The Question of ‘Corruption’ in Nepal

Drawing on ethnographic material about a set of Nepalese cultural practices known as ‘nutabad —ciypabad’, ‘favouritism’, the paper attempts; first, to chart the meaning favouritism has for Nepalis in their everyday encounters with central administration and the forms these interactions take and their cultural significations; second, to examine the way the idea of favouritism is constructed by the Westernized intellectuals to mean corruption and their reasons for so doing. The key sociological concept utilized for this analysis is ‘power’, specifically its operation in the field of political ethics centring on a conflict between two opposing ideologies; one advocated by the Westernized intellectuals who are pressing for the adoption of the principle of ‘impartiality’ in government; the other being that which is inherent in the Hindu traditional mode of statecraft wherein the institution of ‘the favour’ and therefore ‘partiality’ as a value is paramount and is in accord with Hindu cultural values, generally.     

A critique of the principle of ‘respect for autonomy’, grounded in African thought

I give an account how the principle of ‘respect for autonomy’ dominates the field of bioethics, and how it came to triumph over its competitors, ‘respect for persons’ and ‘respect for free power of choice’. I argue that ‘respect for autonomy’ is unsatisfactory as a basic principle of bioethics because it is grounded in too individualistic a worldview, citing concerns of African theorists and other communitarians who claim that the principle fails to acknowledge the fundamental importance of understanding persons within the nexus of their communal relationships. I defend the claim that ‘respect for persons’ is a more appropriate principle, as it is able to acknowledge both individual decision making and the essential relationality of persons. I acknowledge that my preference for ‘respect for persons’ is problematic because of the important debate around the definition of ‘personhood’ in bioethics discourse. Relying on Thaddeus Metz's conception of moral status, I propose a relational definition of personhood that distinguishes between persons with agency and persons without agency, arguing that we have different moral obligations to these distinct categories of persons. I claim that this conception of personhood is better able to accommodate our moral intuitions than conventional approaches, and that it is able to do so without being speciesist or question‐begging.     

FOR HOMEOPATHY: A PRACTISING PHYSICIAN'S PERSPECTIVE

This article is a rebuttal to Kevin Smith's ‘Against Homeopathy,’ which was posted on 14 February 2011. 1 It contends that his argument rests entirely on the assumption that homeopathic remedies are nothing but placebos. His argumentation is good, but his assumption is false. Evidence is presented to show that the Law of Similars is plausible and that ultradilute remedies do indeed have biological activity.     

Is the coral‐algae symbiosis really ‘mutually beneficial’ for the partners?

The consideration of ‘mutual benefits’ and partner cooperation have long been the accepted standpoint from which to draw inference about the onset, maintenance and breakdown of the coral‐algae endosymbiosis. In this paper, I review recent research into the climate‐induced breakdown of this important symbiosis (namely ‘coral bleaching’) that challenges the validity of this long‐standing belief. Indeed, I introduce a more parsimonious explanation, in which the coral host exerts a ‘controlled parasitism’ over its algal symbionts that is akin to an enforced domestication arrangement. Far from being pathogenic, a range of well‐established cellular processes are reviewed that support the role of the coral host as an active ‘farmer’ of the energy‐rich photoassimilates from its captive symbionts. Importantly, this new paradigm reposes the deleterious bleaching response in terms of an envelope of environmental conditions in which the exploitative and captive measures of the coral host are severely restricted. The ramification of this new paradigm for developing management strategies that may assist the evolution of bleaching resistance in corals is discussed.     

Response to cadmium in higher plants

The paper summarizes present knowledge in the field of higher plant responses to cadmium, an important environmental pollutant. The principal mechanisms reviewed here include phytochelatin-based sequestration and compartmentalization processes, as well as additional defense mechanisms, based on cell wall immobilization, plasma membrane exclusion, stress proteins, stress ethylene, peroxidases, metallothioneins, etc. An analysis of data taken from the international literature has been carried out, in order to highlight possible ‘qualitative’ and ‘quantitative’ differences in the response of wild-type (non-tolerant) plants to chronic and acute cadmium stress. The dose-response relationships indicate that plant response to low and high cadmium level exposures is a very complex phenomenon indeed: cadmium evokes a number of parallel and/or consecutive events at molecular, physiological and morphological levels. We propose that, above all in response to acute cadmium stress, various mechanisms might operate both in an additive and in a potentiating way. Thus, a holistic and integrated approach seems to be necessary in the study of the response of higher plants to cadmium. This multi-component model, which we would call ‘fan-shaped’ response, may accord with the Selyean ‘general adaptation syndrome’ hypothesis. While cadmium detoxification is a complex phenomenon, probably under polygenic control, cadmium ‘real’ tolerance—found in mine plants or in plant systems artificially grown under long-term selection pressure, exposed to high levels of cadmium—seems to be a simpler phenomenon, possibly involving only monogenic/oligogenic control. We conclude that, following a ‘pyramidal’ model, (adaptive) tolerance is supported by (constitutive) detoxification mechanisms, which in turn rely on (constitutive) homeostatic processes. The shift between homeostasis and ‘fan-shaped’ response can be rapid and involve quick changes in (poly)gene expression. Differently, the slow shift from ‘fan-shaped’ response to ‘real’ cadmium tolerance is caused and affected by long-term selection pressure, which may increase the frequency (and promote the expression) of one or a few tolerance gene(s).     

Engineered single‐ and multi‐cell chemotaxis pathways in E. coli

We have engineered the chemotaxis system of Escherichia coli to respond to molecules that are not attractants for wild‐type cells. The system depends on an artificially introduced enzymatic activity that converts the target molecule into a ligand for an E. coli chemoreceptor, thereby enabling the cells to respond to the new attractant. Two systems were designed, and both showed robust chemotactic responses in semisolid and liquid media. The first incorporates an asparaginase enzyme and the native E. coli aspartate receptor to produce a response to asparagine; the second uses penicillin acylase and an engineered chemoreceptor for phenylacetic acid to produce a response to phenylacetyl glycine. In addition, by taking advantage of a ‘hitchhiker’ effect in which cells producing the ligand can induce chemotaxis of neighboring cells lacking enzymatic activity, we were able to design a more complex system that functions as a simple microbial consortium. The result effectively introduces a logical ‘AND’ into the system so that the population only swims towards the combined gradients of two attractants.     

Morphogenetic response of shoot tips to cryopreservation by encapsulation-dehydration in a solid mutant and periclinal chimeras of <Emphasis Type="Italic">Chrysanthemum</Emphasis> × <Emphasis Type="Italic">grandiflorum</Emphasis> /Ramat./Kitam.

Cryopreservation is widely applied to many economically important species excluding chimera plants which are problematic for long-term conservation. Their storage problems can be circumvented only by cryopreserving meristems. This study looked at the morphogenetic response of shoot tips of periclinal chimera chrysanthemum ‘Lady Orange’ and ‘Lady Salmon’, as well as the solid mutant ‘Richmond’, that were cryopreserved by encapsulation-dehydration technique. By applying 10 µM ABA in the preculture medium followed by 4-day-long dehydration treatment, the explant survival reached up to 67%. Besides the stimulation of typical single shoot recovery, cryopreservation led to direct or indirect multiple shoot formation, shoot malformation, as well as inhibited their spontaneous rooting. Microscopic analysis revealed three types of structural damages of shoot tips which can correspond with their morphogenetic response in recovery culture. No influence of cryostorage on the acclimatisation efficiency of the recovered chrysanthemums was observed.     

Two kinds of physician‐assisted death

I argue that the concept ‘physician‐assisted suicide’ covers two procedures that should be distinguished: giving someone access to humane means to end his own life, and taking co‐responsibility for the safe and effective execution of that plan. In the first section I explain the distinction, in the following sections I show why it is important. To begin with I argue that we should expect the laws that permit these two kinds of ‘assistance’ to be different in their justificatory structure. Laws that permit giving access only presuppose that the right to self‐determination implies a right to suicide, but laws that permit doctors to take co‐responsibility may have to appeal to a principle of mercy or beneficence. Actually this difference in justificatory structure can to some extent be found in existing regulatory systems, though far from consistently. Finally I argue that if one recognizes a right to suicide, as Oregon and other American states implicitly do, and as the European Court of Human Rights has recently done explicitly, one is committed to permit the first kind of ‘assistance’ under some conditions.     

The influence of host and non‐host companion plants on the behaviour of pest insects in field crops

Companion plants grown as ‘trap crops’ or ‘intercrops’ can be used to reduce insect infestations in field crops. The ways in which such reductions are achieved are being described currently using either a chemical approach, based on the ‘push‐pull strategy’, or a biological approach, based on the ‘appropriate/inappropriate landing theory’. The chemical approach suggests that insect numbers are reduced by chemicals from the intercrop ‘repelling’ insects from the main crop, and by chemicals from the trap‐crop ‘attracting’ insects away from the main crop. This approach is based on the assumptions that (1) plants release detectable amounts of volatile chemicals, and (2) insects ‘respond’ while still some distance away from the emitting plant. We discuss whether the above assumptions can be justified using the ‘appropriate/inappropriate landing theory’. Our tenet is that specialist insects respond only to the volatile chemicals released by their host plants and that these are released in such small quantities that, even with a heightened response to such chemicals, specialist insects can only detect them when a few metres from the emitting plant. We can find no robust evidence in the literature that plant chemicals ‘attract’ insects from more than 5 m and believe that ‘trap crops’ function simply as ‘interception barriers’. We can also find no evidence that insects are ‘repelled’ from landing on non‐host plants. Instead, we believe that ‘intercrops’ disrupt host‐plant finding by providing insects with a choice of host (appropriate) and non‐host (inappropriate) plant leaves on which to land, as our research has shown that, for intercropping to be effective, insects must land on the non‐host plants. Work is needed to determine whether non‐host plants are repellent (chemical approach) or ‘non‐stimulating’ (biological approach) to insects.     

A biological relativity view of the relationships between genomes and phenotypes

This article explores the relativistic principle that there is no privileged scale of causality in biology to clarify the relationships between genomes and phenotypes. The idea that genetic causes are primary views the genome as a program. Initially, that view was vindicated by the discovery of mutations and knockouts that have large and specific effects on the phenotype. But we now know that these form the minority of cases. Many changes at the genome level are buffered by robust networks of interactions in cells, tissues and organs. The ‘differential’ view of genetics therefore fails because it is too restrictive. An ‘integral’ view, using reverse engineering from systems biological models to quantify contributions to function, can solve this problem. The article concludes by showing that far from breaking the supervenience principle, downward causation requires that it should be obeyed.     

Contemporary Urban Buddhist ‘Cults’ and the Socio-Political Order in Thailand

This paper is concerned with the ongoing intense interest in Thailand of two controversial urban Buddhist movements which have appeared since the beginning of the seventies, Santi Asok and Thammakaai. Essentially, I view both as a resonance of the perceived need for ‘change’ among an articulate aspiring new middle class. I also argue that both Santi Asok and Thammakaai in their expressions — Thammakaai the specious discursive function of capital, Santi Asok by confrontation and spurning what they consider an ‘amoralistic’ establishment — are predicating a radical critique of the Thai social order, a call for collective ‘inner-worldly activism’ and ‘individualistic’ reflexive response to convention.     

Time‐shift experiments and patterns of adaptation across time and space

Time‐shift experiments provide measures of the mean fitness of a population in environments of different points in time. Here, we show how to use this type of data to decompose mean fitness into (1) the effect of the environment in which the population is transplanted, (2) the effect of the genetic composition of the population and (3) ‘temporal adaptation’, which measures how the population fits the environment at that time. We derive analytical results for the pattern of ‘temporal adaptation’ and show that it is in general maximal in the recent past. The link between ‘temporal adaptation’ and ‘local adaptation’ is discussed, and we show when patterns of adaptation in time and space are expected to be similar. Finally, we illustrate the potential use of this approach using a data set measuring the adaptation of HIV to the immune response of several recently infected patients.     

Fair Innings and Time‐Relative Claims

Greg Bognar has recently offered a prioritarian justification for ‘fair innings’ distributive principles that would ration access to healthcare on the basis of patients' age. In this article, I agree that Bognar's principle is among the strongest arguments for age‐based rationing. However, I argue that this position is incomplete because of the possibility of ‘time‐relative' egalitarian principles that could complement the kind of lifetime egalitarianism that Bognar adopts. After outlining Bognar's position, and explaining the attraction of time‐relative egalitarianism, I suggest various ways in which these two kinds of principle could interact. Since various options have very different implications for age‐based rationing, proponents of such a rationing scheme must take a position on time‐relative egalitarianism to complement a lifetime prioritarian view like Bognar's.     

The ‘sparkle’ in fake eyes – the protective effect of mimic eyespots in lepidoptera

Many species of lepidoptera bear conspicuous circular patterns on their wings, known as eyespots, that are hypothesised to protect their bearers against predatory birds. In this study, we focus on a small but ubiquitous feature occurring naturally in lepidopteran eyespots, namely the so‐called ‘sparkle’. The ‘pupil’ in an eyespot is often highlighted by a ‘sparkle’, which is hypothesised to mimic a natural corneal total light reflection evident as a highlight, twinkle, or sparkle in the vertebrate eye. In a study exploring the presence of such sparkles, we found that 53% of lepidopteran eyespots exceeding 1 mm in diameter have a central, pinpoint‐like ‘sparkle’, 12% have a marginal, crescent‐shaped ‘sparkle’, 13% have a semi‐circular ‘sparkle’, and 22% have an intermediate semi‐circular to crescent‐shaped ‘sparkle’. In the lepidopterans’ natural resting position, the marginal ‘sparkles’ are positioned in the upper part of the eyespots’‘pupil’ and thus may create the illusion of a spherical eyeball. The ‘sparkles’ in lepidopteran eyespots do not only appear white to humans, but also reflect ultraviolet light. White and UV‐reflecting ‘sparkles’ also appear ‘white’ for UV‐sensitive viewers such as birds, and thus may effectively mimic the natural highlight in vertebrate eyes as an area of total light reflection. In field experiments using lepidopteran dummies baited with a mealworm, we show that the ‘sparkle’ is one of several components of eyespots eliciting a deterrent effect and that eyespots with a ‘sparkle’ in a natural position have a stronger deterrent effect than those with a ‘sparkle’ in an unnatural position. These findings support the eye mimicry hypothesis that better vertebrate eye mimicry improves the deterrent effect of eyespots.     

Valuing Lives and Allocating Resources: A Defense of the Modified Youngest First Principle of Scarce Resource Distribution

In this paper, I argue that the ‘modified youngest first’ principle provides a morally appropriate criterion for making decisions regarding the distribution of scarce medical resources, and that it is morally preferable to the simple ‘youngest first’ principle. Based on the complete lives system's goal of maximizing complete lives rather than individual life episodes, I argue that essential to the value we see in complete lives is the first person value attributed by the experiencer of that life. For a life to be ‘complete’ or ‘incomplete,’ the subject of that life must be able to understand the concept of a complete life, to have started goals and projects, and to know what it would be for that life to be complete. As the very young are not able to do this, it can reasonably be said that their characteristically human lives have not yet begun, giving those accepting a complete lives approach good reason to accept the modified youngest first principle over a simple ‘youngest first’ approach.     

Morphological homeostasis by autophagy

With cellular organelles coming in all shapes and sizes, the principle ‘form follows function’ is readily discernible through the cytologist’s lens. Architecturally, one might ask whether there is feedback in this organization. Does a cell ‘know’ when it has constructed membrane into the stacks of the Golgi, the cisternae of the mitochondria or the tubules of the endoplasmic reticulum? Proofreading can occur in vivo as both errors in nucleic acids and misfolds in proteins are recognized by the cell. Are there analogous systems which maintain/regulate the architectural integrity of organelles? Our recent paper entitled “Generation of cubic membranes from controlled homotypic interactions of membrane proteins in the endoplasmic reticulum” suggests that autophagy may play such a role.     

A periodic table for ecology? A chemist's view of plant functional types

Abstract. A functional type approach, in which the complexity found in nature is reduced by grouping organisms that are functionally similar into a single classification, is being promoted in global change research. This paper examines a proposed analogy between this functional type approach in global change ecology and the periodic table of the elements in chemistry. When applied to a ‘bottom-up’ approach for defining functional types in ecology, in which large numbers of organisms are classified into smaller groups based on similarity of certain functions, the analogy fails. Ecological functions are not simple attributes of a biological entity, as electronic structure is for a chemical element, but are themselves complex chemical and physical systems that often interact strongly with the environment. The analogy to the periodic table may be of some use as an organizing tool in a ‘top-down’ approach in which a modelling context is used to define the number of ‘elements’ and their properties. This will be elaborated for plant functional types. Each PFT is assigned characteristics that allow its response to the driving forces of change, e.g. temperature, precipitation, soil nutrients, disturbance, to be predicted. ‘Rules of combination’ determine how the mix of PFTs in a particular ecosystem changes to form different ecosystems, which would correspond in the analogy to chemical compounds. However, these requirements present significant challenges to the usefulness of the analogy, even as an organizing tool in the ‘top-down’ approach.