Solar-wind interaction with planetary ionospheres

Planetary encounters by numerous spacecraft have furnished information concerning the solar wind interaction with the planets Mercury, Venus, Mars, and Jupiter. While direct measurements have indicated a wide range of atmospheric densities and intrinsic magnetic field strengths, the data seem to indicate that the flow pattern around nonmagnetized or weakly magnetized planets with atmospheres optically thick at ionizing wavelengths is basically the same as that around a strongly magnetized planet's magnetosphere, such as the earth's. The planetary ionosphere apparently presents a hard obstacle to the flow, with bow shock formation required in the supersonic, super-Alfvenic flow to slow and direct most of the solar wind plasma around the planetary ionosphere. Various aspects of the interaction are examined in the context of theoretical models in an attempt to explain observed details of the interaction regions of Venus and Mars

The effect of prior victory or defeat in the same site as that of subsequent encounter on the determination of dyadic dominance in the domestic hen

We examined the effect of prior victory or defeat in the same site as that of a subsequent encounter on the outcome of dyadic encounter of domestic hens by placing them in two situations: In the first set of dyads, two unacquainted hens having experienced prior victory were introduced in the site where one had experienced victory. In the second set, two unacquainted hens having experienced defeat were introduced in the site where one had recently lost. Results indicate that victories are equally shared between individuals with prior victory experiences, while familiarity with the meeting site did not give any advantage. However, hens having previously lost were disadvantaged when the encounter occurred in the same site as that of their prior defeat. This demonstrates that previous social experience in a site is more important on the outcome of subsequent encounters for losers than winners. Losers seem to associate the site with the stressful effect of losing or being more easily dominated

Effets de travaux de curage sur la faune benthique d'un cours d'eau d'une région agricole du Québec

Une étude quantitative et qualitative du benthos du Ruisseau des Anges (Comté de Montcalm, Québec), un bassin à vocation agricole, réalisée de 1986 à 1988, a permis d'évaluer les effets d'un curage effectué en 1987.L'échantillonnage couvrait les zones d'amont destinées être curés, ainsi que des sites en aval des travaux et des sites témoins. Les cours d'eau y sont enrichis, principalement en azote, et le benthos s'avère dominé par les Oligochètes Tubificidae. Mémo la station-témoin, située dans une zone plus boisée, contient une faune appauvrie, bien que plus diversifiée, dominée par les Diptères Chironomidae, les Mollusques Sphaeriidae, les Coléoptères Elmidae et les Mégaloptères Sialidae, groupes résistants à la pollution. Le curage a éliminé les accumulations de boues organiques, ainsi que les plantes aquatiques qui les retenaient, et favorisé la colonisation du milieu par les Diptères Chironomidae. Cependant, dès l'automne suivant (1988), l'envasement avait repris et les Tubificidae avaient recouvré leur position de dominance, particulièrement dans les stations d'amont, sans toutefois atteindre les densités de 1986. Les bénéfices du curage sur le benthos ont été de faible importance et de courte durée, dans la mesure où l'envasement et la pollution organique maintiennent des conditions de dégradation en absence de mesures efficaces de contrôle de l'érosion. L'utilisation de plusieurs indices biotiques pour décrire l'état des cours d'eau illustre la difficulté de leur application à des cours d'eau de plaine.A quantitative and qualitative study of the benthos of Ruisseau des Anges (Montcalm County, Quebec), in an agricultural area, in 1986 to 1988 was undertaken to evaluate the effects of ditching operations in 1987.Sampling included upstream zones where the ditching occurred, downstream stations, and control areas. All streams were enriched, particularly in nitrogen, and their benthic fauna was dominated by Tubificidae (Oligochaeta). Even the control area had a reduced fauna dominated by Chironomidae (Diptera), Sphaeriidae (Mollusca), Elmidae (Coleoptera) and Sialidae (Megaloptera), all resistant to pollution. The ditching operations eliminated the accumulated mud and destroyed the vegetation winch choked the streams. This allowed a colonization by Chironomidae. However, by the fall of 1988 much silting had occurred and the Tubificidae reestablished, though not in the high densities of 1986. Any improvement of the benthic fauna was marginal and shortlived, as silting and organic pollution restored the degradated conditions in the absence of erosion control. The use of several biotic indices to assess stream conditions showed that these are often unsatisfactory in lowland streams

Virtual reality as a new approach to assess cognitive decline in the elderly

Brain aging is a natural process that leads to a change in cognitive functions. Mild Cognitive Impairment (MCI) is a condition in which a person has cognitive functions that are below normal for his age. However, these deficits are not pronounced enough to confirm for the diagnosis of dementia. It is therefore important to develop new ways to assess cognitive functions in the elderly. This would indeed lead to a better identification of the cognitive losses that are related to normal or pathological aging. The objective of this study was to investigate the relevance of virtual reality as a new evaluation approach in psychology. To do this, 10 elderly people with Mild Cognitive Impairment, and 20 elderly people without cognitive problems, were compared using tests of prospective memory that were presented in a traditional way and in virtual reality. The diagnosis of MCI was made using the Montreal Cognitive Assessment (MoCA). Significant differences between the two groups were noted in virtual reality. Nevertheless, no difference was observed between the two groups with the traditional task. A significant positive correlation between the virtual reality task and the MoCA, but not between the traditional task and the MoCA, was observed. An evaluative approach based on virtual reality seems more sensitive to cognitive impairment associated with aging than an approach based on traditional neuropsychological tests.

Guidelines for physical weed control research: flame weeding, weed harrowing and intra-row cultivation

A prerequisite for good research is the use of appropriate methodology. In order to aggregate sound research methodology, this paper presents some tentative guidelines for physical weed control research in general, and flame weeding, weed harrowing and intra-row cultivation in particular. Issues include the adjustment and use of mechanical weeders and other equipment, the recording of impact factors that affect weeding performance, methods to assess effectiveness, the layout of treatment plots, and the conceptual models underlying the experimental designs (e.g. factorial comparison, dose response). First of all, the research aims need to be clearly defined, an appropriate experimental design produced and statistical methods chosen accordingly. Suggestions on how to do this are given. For assessments, quantitative measures would be ideal, but as they require more resources, visual classification may in some cases be more feasible. The timing of assessment affects the results and their interpretation. When describing the weeds and crops, one should list the crops and the most abundantly present weed species involved, giving their density and growth stages at the time of treatment. The location of the experimental field, soil type, soil moisture and amount of fertilization should be given, as well as weather conditions at the time of treatment. The researcher should describe the weed control equipment and adjustments accurately, preferably according to the prevailing practice within the discipline. Things to record are e.g. gas pressure, burner properties, burner cover dimensions and LPG consumption in flame weeding; speed, angle of tines, number of passes and direction in weed harrowing. The authors hope this paper will increase comparability among experiments, help less experienced scientists to prevent mistakes and essential omissions, and foster the advance of knowledge on non-chemical weed management

Justification, evaluation and critique in the study of organization: An introduction to the volume

This volume presents state-of-the-art research and thinking on the analysis of justification, evaluation and critique in organizations, as inspired by the foundational ideas of French Pragmatist Sociology’s economies of worth (EW) framework. In this introduction, we begin by underlining the EW framework’s importance in sociology and social theory more generally and discuss its relative neglect within organizational theory, at least until now. We then present an overview of the framework’s intellectual roots, and for those who are new to this particular theoretical domain, offer a brief introduction to the theory’s main concepts and core assumptions. This we follow with an overview of the contributions included in this volume. We conclude by highlighting the EW framework’s important yet largely untapped potential for advancing our understanding of organizations more broadly. Collectively, the contributions in this volume help demonstrate the potential of the EW framework to (1) advance current understanding of organizational processes by unpacking justification dynamics at the individual level of analysis, (2) refresh critical perspectives in organization theory by providing them with pragmatic foundations, (3) expand and develop the study of valuation and evaluation in organizations by reconsidering the notion of worth, and finally (4) push the boundaries of the framework itself by questioning and fine tuning some of its core assumptions. Taken as a whole, this volume not only carves a path for a deeper embedding of the EW approach into contemporary thinking about organizations, it also invites readers to refine and expand it by confronting it with a wider range of diverse empirical contexts of interest to organizational scholars

Mathematical Model and Simulation of a Pneumatic Apparatus for In-Drilling Alignment of an Inertial Navigation Unit during Horizontal Well Drilling

Conventional methods in horizontal drilling processes incorporate magnetic surveying techniques for determining the position and orientation of the bottom-hole assembly (BHA). Such means result in an increased weight of the drilling assembly, higher cost due to the use of non-magnetic collars necessary for the shielding of the magnetometers, and significant errors in the position of the drilling bit. A fiber-optic gyroscope (FOG) based inertial navigation system (INS) has been proposed as an alternative to magnetometer -based downhole surveying. The utilizing of a tactical-grade FOG based surveying system in the harsh downhole environment has been shown to be theoretically feasible, yielding a significant BHA position error reduction (less than 100m over a 2-h experiment). To limit the growing errors of the INS, an in-drilling alignment (IDA) method for the INS has been proposed. This article aims at describing a simple, pneumatics-based design of the IDA apparatus and its implementation downhole. A mathematical model of the setup is developed and tested with Bloodshed Dev-C++. The simulations demonstrate a simple, low cost and feasible IDA apparatus

Characterization of flax germplasm for resistance to fusarium wilt

Non-Peer ReviewedFusarium wilt of flax (Linum usitatissimum L.) caused by Fusarium oxysporum f. sp. lini (Fol) is an economically important disease that can result in severe yield losses. Due to the pathogen’s ability to survive in soil for long periods, it is essential to identify fusarium wilt resistant flax varieties. The objectives of the study were to phenotype and compare a recombinant inbred line (RIL) population of flax in a controlled environment and in field wilt nurseries. Disease reaction of a subset (160) of RIL lines developed from cultivars ‘Aurore’ (moderately resistant) and ‘Oliver’ (susceptible) was assessed under controlled environment conditions to two Fol isolates. Disease severity was determined and the area under the disease progress curve (AUDPC) was calculated. The population varied in response from resistant to highly susceptible, indicating that resistant to wilt was probably polygenic. Twenty-eight days after inoculation, 14% and 5% of the RILs were severely wilted (scores of 8 and 9, with isolates 131 and 81, respectively). Plant height was negatively correlated with AUDPC (r2= -0.13155 for 131 and r2=-0.29841 for 81). Similarly, in the field in wilt nurseries, at Saskatoon and Morden, evaluation of the full set of 200 RILs, the disease reaction varied from resistant to susceptible, with 21% and 42% of RILs severely wilted (rated 8 and 9) at each site at the green boll stage. The results from the two locations were significantly different, although moderately correlated (r2=0.6127). The 160 RILs in controlled environment inoculated with isolates 131 and 81 showed a higher correlation for disease severity at 28 days after inoculation, with the wilt nursery in Saskatoon (r= 0.40028 and r2=0.38046) as compared to Morden (r2=0.33016 and r2=0.21140) at green boll stage. Differences in environmental and experimental conditions (such as seeding date) at the two locations, as well as different Fol strains in the soil combined with the subjectivity of the grading system may explain the differences between locations

Activation and enzymatic characterization of recombinant human kallikrein 8

Human kallikrein 8 (hK8), whose gene was originally cloned as the human ortholog of a mouse brain protease, is known to be associated with diseases such as ovarian cancer and Alzheimer's disease. Recombinant human pro-kallikrein 8 was activated with lysyl endopeptidase-conjugated beads. Amino-terminal sequencing of the activated enzyme demonstrated the cleavage of a 9-aa propeptide from the pro-enzyme. The substrate specificity of activated hK8 was characterized using synthetic fluorescent substrates. hK8 showed trypsin-like specificity, as predicted from sequence analysis and enzymatic characterization of the mouse ortholog. All synthetic substrates tested containing either arginine or lysine at P1 position were cleaved by hK8. The highest k cat/K m value of 20×103M-1 s-1 was observed with Boc-Val-Pro-Arg-7-amido-4-methylcoumarin. The activity of hK8 was inhibited by antipain, chymostatin, and leupeptin. The concentration for 50% inhibition by the best inhibitor, antipain, was 0.46μM. The effect of different metal ions on the enzyme activity was analyzed. Whereas Na+ had no effect on hK8 activity, Ni2+ and Zn2+ decreased the activity and Ca2+, Mg2+, and K+ had a stimulatory effect. Ca2+ was the best activator, with an optimal concentration of approximately 10μ