Bayesian personalism,the methodology of scientific research programmes,and Duhem's problem

The detailed analysis of a particular quasi-historical numerical example is used to illustrate the way in which a Bayesian personalist approach to scientific inference resolves the Duhemian problem of which of a conjunction of hypotheses to reject when they jointly yield a prediction which is refuted. Numbers intended to be approximately historically accurate for my example show, in agreement with the views of Lakatos, that a refutation need have astonishingly little effect on a scientist's confidence in the ‘hard core’ of a successful research programme even when a comparable confirmation would greatly enhance that confidence (an initial confidence of 0.9 fell by a fraction of a percent in the refutation case and rose to only a fraction of a percent short of unity in the comparable confirmation case). Timeo Danaos et dona ferentis.     

Kuhn’s Structure of Scientific Revolutions between sociology and epistemology

The aim of the paper is to clarify Kuhn’s theory of scientific revolutions. We propose to discriminate between a scientific revolution, which is a sociological event of a change of attitude of the scientific community with respect to a particular theory, and an epistemic rupture, which is a linguistic fact consisting of a discontinuity in the linguistic framework in which this theory is formulated. We propose a classification of epistemic ruptures into four types. In the paper, each of these types of epistemic ruptures is illustrated by examples from physics. The classification of epistemic ruptures can be used as a basis for a classification of scientific revolutions and thus for a refinement of our view of the progress of science.     

Fourth World Conference on Women: the Namibian perspective

This consideration of some of the issues raised at the Fourth World Conference on Women (WCW) from a Namibian perspective begins by mentioning the pernicious nature of domestic violence and briefly summarizing some of the main points raised at a 1994 symposium on domestic violence. The discussion continues by noting that Namibia's report for the WCW reaffirms that it is crucial for women to be involved in the decision-making process at all levels. Next, the paper notes that traditional male attributes of strength are losing their importance in a world that values mental alertness, intuition, and traditional female qualities of love and service. This has led to a call for a transformation of society supported by the education of women and their economic empowerment. The essay ends by defining an empowered person as possessing a belief in the ability of human intervention to change the world, a sense of self-worth, a sense of the self as a viable agent of change, and a notion of what constitutes a better life.     

The role of Rab5a GTPase in endocytosis and post-endocytic trafficking of the hCG-human luteinizing hormone receptor complex

This study examined the role of Rab5a GTPase in regulating hCG-induced internalization and trafficking of the hCG-LH receptor complex in transfected 293T cells. Coexpression of wild-type Rab5a (WT) or constitutively active Rab5a (Q79L) with LHR significantly increased hCG-induced LHR internalization. Conversely, coexpression of dominant negative Rab5a (S34N) with LHR reduced internalization. Confocal microscopy showed LHR colocalizing with Rab5a (WT) and Rab5a (Q79L) in punctuate structures. Coexpression of Rab5a (WT) and Rab5a (Q79L) with LHR significantly increased colocalization of LHR in early endosomes. Conversely, dominant negative Rab5a (S34N) decreased this colocalization. While Rab5a stimulated internalization of LHR, it significantly decreased LHR recycling to the cell surface and increased degradation. Dominant negative Rab5a (S34N) increased LHR recycling and decreased degradation. These results suggest that Rab5a plays a role in LHR trafficking by facilitating internalization and fusion to early endosomes, increasing the degradation of internalized receptor resulting in a reduction in LHR recycling.     

Impact of climate change on wetland ecosystems: A critical review of experimental wetlands

Climate change is identified as a major threat to wetlands. Altered hydrology and rising temperature can change the biogeochemistry and function of a wetland to the degree that some important services might be turned into disservices. This means that they will, for example, no longer provide a water purification service and adversely they may start to decompose and release nutrients to the surface water. Moreover, a higher rate of decomposition than primary production (photosynthesis) may lead to a shift of their function from being a sink of carbon to a source. This review paper assesses the potential response of natural wetlands (peatlands) and constructed wetlands to climate change in terms of gas emission and nutrients release. In addition, the impact of key climatic factors such as temperature and water availability on wetlands has been reviewed. The authors identified the methodological gaps and weaknesses in the literature and then introduced a new framework for conducting a comprehensive mesocosm experiment to address the existing gaps in literature to support future climate change research on wetland ecosystems. In the future, higher temperatures resulting in drought might shift the role of both constructed wetland and peatland from a sink to a source of carbon. However, higher temperatures accompanied by more precipitation can promote photosynthesis to a degree that might exceed the respiration and maintain the carbon sink role of the wetland. There might be a critical water level at which the wetland can preserve most of its services. In order to find that level, a study of the key factors of climate change and their interactions using an appropriate experimental method is necessary. Some contradictory results of past experiments can be associated with different methodologies, designs, time periods, climates, and natural variability. Hence a long-term simulation of climate change for wetlands according to the proposed framework is recommended. This framework provides relatively more accurate and realistic simulations, valid comparative results, comprehensive understanding and supports coordination between researchers. This can help to find a sustainable management strategy for wetlands to be resilient to climate change.     

Impact of climate change on wetland ecosystems: A critical review of experimental wetlands

Climate change is identified as a major threat to wetlands. Altered hydrology and rising temperature can change the biogeochemistry and function of a wetland to the degree that some important services might be turned into disservices. This means that they will, for example, no longer provide a water purification service and adversely they may start to decompose and release nutrients to the surface water. Moreover, a higher rate of decomposition than primary production (photosynthesis) may lead to a shift of their function from being a sink of carbon to a source. This review paper assesses the potential response of natural wetlands (peatlands) and constructed wetlands to climate change in terms of gas emission and nutrients release. In addition, the impact of key climatic factors such as temperature and water availability on wetlands has been reviewed. The authors identified the methodological gaps and weaknesses in the literature and then introduced a new framework for conducting a comprehensive mesocosm experiment to address the existing gaps in literature to support future climate change research on wetland ecosystems. In the future, higher temperatures resulting in drought might shift the role of both constructed wetland and peatland from a sink to a source of carbon. However, higher temperatures accompanied by more precipitation can promote photosynthesis to a degree that might exceed the respiration and maintain the carbon sink role of the wetland. There might be a critical water level at which the wetland can preserve most of its services. In order to find that level, a study of the key factors of climate change and their interactions using an appropriate experimental method is necessary. Some contradictory results of past experiments can be associated with different methodologies, designs, time periods, climates, and natural variability. Hence a long-term simulation of climate change for wetlands according to the proposed framework is recommended. This framework provides relatively more accurate and realistic simulations, valid comparative results, comprehensive understanding and supports coordination between researchers. This can help to find a sustainable management strategy for wetlands to be resilient to climate change.     

Cytogenetics of South American akodont rodents (Cricetidae). V. Segregation of chromosome No. 1 polymorphism in Akodon molinae

Akodon molinae is polymorphic with 2n=42, 43, 44, where the metacentric autosome No. 1 is homologous to 2 acrocentrics 1a and 1b. Matings between 2n=43 heterozygotes 1/1a, 1b gave a surplus of 1/1 offspring, a moderate reduction of heterozygous and a strong reduction of homozygous 1a, 1b/1a, 1b offspring. The latter type also has a highly reduced fertility.     

‘The happy thought of a single man’: On the legendary beginnings of a style of reasoning

In this paper I direct attention to one feature of Hacking’s recent work on styles of reasoning and argue that this feature is of far greater philosophical significance than Hacking’s limited discussion of this suggests. The feature in question is his use of ‘legendary beginnings’ in setting out a given style, viz. the method of introducing a style of reasoning by recounting a popular and quasi-mythical narrative that ties the crystallisation of that style to a particular person in a particular place and at a particular time. Whilst Hacking both deploys and discusses this method, his comments suggest that this is primarily a stylistic device employed for reasons of expedience. In contrast, it is argued here that recounting the legendary origins of a style of reasoning affords a distinctive way of vindicating that style, a vindication from within the style itself.     

Changes in the cardiac glutathione status after ischemia and reperfusion

In the isolated and perfused rabbit heart ischemia induced a rapid decline of contractility, associated with a reduction of the content of tissue GSH with no significant changes in GSSG. Reperfusion induced a small recovery of contractility, a substantial release of total glutathione and a further decrease in the content of tissue GSH with a significant increase of tissue GSSG. Glutathione reductase and glutathione peroxidase activities were not affected by ischemia and reperfusion. This study suggests a possible role for glutathione in the determination of functional damage induced by myocardial ischemia and reperfusion.     

Effect of daily parenteral injection of betamethasone on histamine concentration of gastric tissue in albino rats

Summary Gastric tissue histamine concentration was determined in albino rats following daily parenteral injection of betamethasone over a period of 12 days. The result shows a highly significant fall in gastric tissue histamine concentration in comparison with that in saline-treated albino rats over a similar period.This investigation was carried out as a part of a project supported by a research grant from Medical Research Centre, Bombay Hospital Trust, Bombay, India.     

Karyotypes of shrews of the generaCryptotis andBlarina (mammalia: Soricidae)

Summary Cryptotis parva has a diploid number of 52 and a fundamental number of 50. Blarina brevicauda in Nebraska and Pennsylvania has a diploid number of 49 or 50 and a fundamental number of 48. Blarina carolinensis in Nebraska and Kansas has a diploid number of 52 and a fundamental number of 62. The X-chromosome in all 3 species is a large metacentric chromosome. The Y-chromosome is a small acrocentric in Blarina, whereas in Cryptotis it is a small subtelocentric.Funds for field work were provided by the American Philosophical Society from the Johnson Fund. We thank Dr Robert J. Baker, Texas Tech University, for use of his karyological equipment and laboratory facilities.     

Combining multiple forecasts given multiple objectives

This paper is concerned with expanding the decision support capabilities of computerized forecasting systems. The expansion allows for the systematic combination of multiple forecasts and the explicit consideration of multiple objectives in the forecast selection process. The methodology used is multiple objective linear programming. Selecting an individual forecast based upon a single objective may not make the best use of available information for a variety of reasons. Combined forecasts may provide a better fit with respect to a single objective than any individual forecast. Even if an individual forecast does provide a good fit with respect to a single objective, a combined forecast may provide a better fit with respect to multiple objectives. An example is used to illustrate the expanded decision support system, its outputs and their properties.     

Receptor potential of rat taste cell to potassium benzoate.

Rat taste cells responded to relatively low concentrations of K-benzoate with a hyperpolarization and to the high concentrations with a depolarization. During both responses the membrane resistance of a taste cell decreased. Depolarization elicited by application of a combination of 0.25 M NaCl and 0.05 M K-benzoate was smaller than that by the NaCl alone, indicating a depressant action of K-benzoate.     

The filtering of transitory noise in earnings numbers

This paper applies the Kalman filtering procedure to estimate persistent and transitory noise components of accounting earnings. Designating the transitory noise component separately (under a label such as extraordinary items) in financial reports should help users predict future earnings. If a firm has no foreknowledge of future earnings, managers can apply a filter to a firm's accounting earnings more efficiently than an interested user. If management has foreknowledge of earnings, application of a filtering algorithm can result in smoothed variables that convey information otherwise not available to users. Application of a filtering algorithm to a sample of firms revealed that a substantial number of firms exhibited a significant transitory noise component of earnings. Also, for those firms whose earnings exhibited a significant departure from the random walk process, the paper shows that filtering can be fruitfully applied to improve predictive ability.     

Oxygen consumption of hibernating worker ants Dolichoderus quadripunctatus as a function of temperature and level of population]

The oxygen consumption of "hibernating" ants shows a grouping effect translated by a significant decrease in the level of oxygen consumption as a function of grouping effect. The general relation between oxygen consumption and the living body mass is the same, if the living material belongs to a single animal, or a social community of ants.     

Autoradiographic study of a bacterial colony. Application to the effects of polymyxin on Pseudomonas aeruginosa colonies]

The autoradiograph of a colony of Ps. a. which has been transferred, during growth, on a medium added with polymyxin and tritiate leucin makes it possible to locate an upper zone with a high metabolic activity and a basal zone with no metabolic activity. The latter, which consists of lysed cells, acts probably as a selective filter against the drug.     

Ouabain--a link in the genesis of high blood pressure?

Hypertension or high blood pressure is a risk factor that increases risk of myocardial infarction, renal failure or cerebral stroke. The pathogenesis of hypertension is due to a variety of causes, including inherited predisposition, dietary habits, especially salt intake, smoking, and also 'general lifestyle'. But for the scientist interested in the complex interplay of physiological and molecular factors, the actual causes of high blood pressure remain uninvestigated. The following article is concerned with new reports that ouabain, a plant derivative, occurs in human beings, in whom it appears to have a hormonal function; ouabain may even play a key role in the pathogenesis of hypertension. We are thus brought a step closer to the background of cardiovascular disease; we may also be afforded a lead to a new therapeutic principle.     

Self-induced decoherence: a new approach

According to Zurek, decoherence is a process resulting from the interaction between a quantum system and its environment; this process singles out a preferred set of states, usually called “pointer basis”, that determines which observables will receive definite values. This means that decoherence leads to a sort of selection which precludes all except a small subset of the states in the Hilbert space of the system from behaving in a classical manner: environment-induced-superselection—einselection—is a consequence of the process of decoherence. The aim of this paper is to present a new approach to decoherence, different from the mainstream approach of Zurek and his collaborators. We will argue that this approach offers conceptual advantages over the traditional one when problems of foundations are considered; in particular, from the new perspective, decoherence in closed quantum systems becomes possible and the preferred basis acquires a well founded definition.     

Pollen carryover and neighbourhood inRanunculus bulbosus

The pattern of gene flow has a major influence on the spatial scale of evolutionary processes. In plant populations pollen carryover will influence the pattern of gene flow. InRanunculus bulbosus L. pollen carryover was found to occur over a maximum of 5 flowers, with seed set per flower decreasing in a curvilinear fashion with increasing visit number in a sequence of visits by a bee after pollen pick-up from a donor plant. The effect of pollen carryover is to increase both neighbourhood area and neighbourhood size by two-fold.     

Forecasting with missing data: application to coastal wave heights

This paper presents a comparative analysis of linear and mixed models for short‐term forecasting of a real data series with a high percentage of missing data. Data are the series of significant wave heights registered at regular periods of three hours by a buoy placed in the Bay of Biscay. The series is interpolated with a linear predictor which minimizes the forecast mean square error. The linear models are seasonal ARIMA models and the mixed models have a linear component and a non‐linear seasonal component. The non‐linear component is estimated by a non‐parametric regression of data versus time. Short‐term forecasts, no more than two days ahead, are of interest because they can be used by the port authorities to notify the fleet. Several models are fitted and compared by their forecasting behaviour. Copyright © 1999 John Wiley & Sons, Ltd.