Swimming activity responses to water current reversal support selective tidal-stream transport hypothesis in juvenile thinlip mullet Liza ramada

Swimming activity of thinlip mullet Liza ramada in response to water current reversal was investigated experimentally. A total of 130 young of the year thinlip mullet ranging in size from 22 to 36 mm were entered in trials with four different conditions over three weeks. The fish were subjected to current reversal (6.2/6.2 h) and a Light-Dark cycle (12/12 h). Swimming direction (with or against the current) was video-recorded throughout the experiments. The mullet showed an effective synchronisation of their swimming activity to water current reversal and Light-Dark cycle. This synchronisation could demonstrate the existence of a diurnal selective tidal-stream transport in the natural environment as observed in the two other European catadromous species.     

Mycopathogens of Mites in Poland - A Review

Studies on diseases of mites caused by entomopathogenic fungi have been undertaken in Poland about a half a century later than in West European countries. Nevertheless, during the last 30 years almost 40 species of arthropod pathogenic fungi have been identified, among them 23 species of Entomophthorales, 12 species of Hyphomycetales and four species of ectoparasitic Laboulbeniales. The most common are representatives of the genus Hirsutella , found both on phytophagous and parasitic or predaceous mites. Percentage infection by H. thompsonii in populations of some tarsonemid and eriophyid mites increases slowly from the end of spring reaching a maximum of 30-60% in August-September. Neozygites floridana is a common entomophthoralean species causing epizootics in spider mite populations; infection also peaks in late summer and autumn. The most numerous fungal taxa have been identified from the resting spores produced internally within the body of the host and show features of the genus Tarichium . From the total number of the taxa recorded within these studies, 22 were described as species new to science. Current research on invertebrate pathology in Poland includes many groups of mites and among their pathogens fungal diseases seem to be the most common.     

Effect of Herbivore Density, Timing of Attack and Plant Community on Performance of Creeping Thistle Cirsium arvense (L.) Scop. (Asteraceae)

Creeping thistle, Cirsium arvense (L.) Scop. (Asteraceae), is one of the most serious weeds in ecological compensation areas (within-field or border refugia) in Europe. Since conventional weed control measures are restricted in compensation areas, augmenting indigenous agents for biological control of the weed may be a feasible alternative. In this paper, we studied the effect of density of the shield beetle, Cassida rubiginosa Muller (Coleoptera, Chrysomelidae), and two vegetation types typical for ecological compensation areas, on the performance of creeping thistle plants in an open field experiment. Early-season larval feeding had no measurable effect on creeping thistle growth, while late-season feeding significantly reduced shoot growth. These findings were attributed to higher feeding rates of the herbivores at higher ambient temperatures late in the season. Defoliation had a strong effect on the above-ground performance of C. arvense plants, but not on the below-ground performance. In contrast, the plant community affected all below-ground performance parameters measured, but only some of the above-ground performance parameters of creeping thistle. A combination of high levels of plant competition and herbivory by C. rubiginosa larvae led to 50% mortality in C. arvense plants during the growing season. We conclude that augmentation of indigenous herbivores of C. arvense in combination with breaking up the root system by tillage and the establishment of a highly competitive plant community of beneficial herbs may be a feasible way to control this problematic weed in ecological compensation areas.     

Arguing with the KGB Archives. Archival and Narrative Memory in Post-Soviet Latvia

This paper is a sequel to my earlier work on life histories in post-Soviet Latvia. The opening of the KGB archives in Riga created the possibility of comparing archival information with recorded personal narratives. The files and the highly charged emotional responses that they evoked raise questions about the uses of language as it moves along a continuum from rigid formalisation to free poetic constructions. Excessive formalisation and institutionalisation of language preclude dialogue and rather than pin down meaning end up by destroying it. Nevertheless, informants were keen to engage in retrospective dialogue with the files, contesting facts and meanings and in the process subverting the original enterprise and reasserting themselves as moral agents.     

Laboratory Evaluation of a Laboratory-selected Organophosphate-resistant Strain of Amblyseius finlandicus (Acari: Phytoseiidae) for Possible Use in Finnish Apple Orchards

The survival of adults and immatures, and reproduction at rates of 150, 300 and 900 ppm a.i. of azinphosmethyl were compared among four types of Amblyseius finlandicus females and their offspring; a laboratory-selected colony (SEL16) resistant to azinphosmethyl, an unselected base colony (Tuorla), reciprocal F1 females from crosses between SEL16 and a very susceptible colony (Hiekkaharju). The SEL16 and reciprocal F1 females had a higher survivorship than the unselected Tuorla base colony after 2 and 4 days on leaves treated with the three concentrations of insecticide. Azinphosmethyl decreased oviposition by the surviving females of all types, but the decrease was smaller in the SEL16 strain than in the base colony. The survivorship of immatures of SEL16 on fresh azinphosmethyl residues after 6 days was low at all three concentrations, but no survivors were found in the base colony at any of the concentrations. Females deposited significantly more eggs on the untreated areas of the leaves. The importance of this behavior for biological control is discussed. There were no significant differences in developmental rate, ovipositional rate, sex ratio and ovipositional period between the SEL16 and unselected base colony on untreated leaf substrates, suggesting that resistance was not associated with decreased fitness. A mode of inheritance study indicated that azinphosmethyl resistance was incompletely dominant. This was also suggested by the results of bioassays, where the reciprocal F1 females performed nearly as well as the SEL16 strain on leaves treated with field rates of azinphosmethyl.     

The toughness of secondary cell wall and woody tissue

The ''across grain'' toughness of 51 woods has been determined on thin wet sections using scissors. The moisture content of sections and the varying sharpness of the scissor blades had little effect on the results. In thin sections (less than 0.6mm), toughness rose linearly with section thickness. The intercept toughness at zero thickness, estimated from regression analysis, was proportional to relative density, consistent with values reported for non-woody plant tissues. Extrapolation of the intercept toughness of these woods and other plant tissues/materials to a relative density of 1.0 predicted a toughness of 3.45kJ m^-2 , which we identify with the intrinsic toughness of the cell wall. This quantity appears to predict published results from K_IC tests on woods and is related to the propensity for crack deflection. The slope of the relationship between section thickness and toughness, describing the work of plastic buckling of cells, was not proportional to relative density, the lightest (balsa) and heaviest (lignum vitae) woods fracturing with less plastic work than predicted. The size of the plastic zone around the crack tip was estimated to be 0.5mm in size. From this, the hypothetical overall toughness of a thick (greater than 1 mm) block of solid cell wall material was calculated as 39.35 kJ m^-2, due to both cell wall resistance (10 per cent) and the plastic buckling of cells (90 per cent). This value successfully predicts the toughness of most commercial woods (of relative densities between 0.2 and 0.8) from ''work area'' tests in tension and bending. Though density was the most important factor, both fibre width/fibre length (in hardwoods) and lignin/cellulose ratios were negatively correlated with the work of plastic buckling, after correcting for density. At low densities the work of plastic buckling in the longitudinal radial (LR) direction exceeded that in longitudinal tangential (LT), but the reverse was true for relative densities above 0.25. This could be attributed to the direction of rays. Density for density, the toughness of temperate hardwoods tested was about 20 per cent lower than that of tropical hardwoods. This is probably due to the much greater number of vessels in temperate hardwoods. Vessels appear either not to display buckling behaviour during fracture at all or to collapse cheaply. These general results have applications to other plant tissues.     

Confronting the angry rock: American Indians' situated risks from radioactivity

Numic people in the western United States are co-adapted with their traditional lands and these lands are spiritually and physically co-adapted with these people. This relationship has been documented through studies funded by the Department of Energy, Nevada Operations. 1 The u.s. Department of Energy Nevada Operations studies of American Indiacultural impacts from the transportation of Low Level Radioactive Waste were managed by Frank DiSanza. Consultation with the involved tribes was guided by Robert Furlow through the American Indian Program. Elders from twenty-six Indian tribes participated in two studies in order to explain why the transportation of radioactive waste poses serious threats. Key in their interpretation is the perception that radioactive material is an angry rock. Indian knowledge and use of this rock goes back for thousands of years. As a powerful spiritual being the angry rock constitutes a threat that can neither be contained nor controlled by conventional means. It has the power to pollute food, medicine, and places, none of which can be used afterwards by Indian people. Spiritual impacts are even more threatening, given that the angry rock would pass along highways where there are animal creation places, access to spiritual beings, and unsung human souls. A most troubling concern is that radioactivity would be transported along the path to the afterlife. The juxtaposition of the angry rock and human spirits being sung to the afterlife is unthinkable.     

Phosphorylation of Tau at Thr212, Thr231, and Ser262 Combined Causes Neurodegeneration

Abnormal hyperphosphorylation of the microtubule-associated protein Tau is a hallmark of Alzheimer disease and related diseases called tauopathies. As yet, the exact mechanism by which this pathology causes neurodegeneration is not understood. The present study provides direct evidence that Tau abnormal hyperphosphorylation causes its aggregation, breakdown of the microtubule network, and cell death and identifies phosphorylation sites involved in neurotoxicity. We generated pseudophosphorylated Tau proteins by mutating Ser/Thr to Glu and, as controls, to Ala. These mutations involved one, two, or three pathological phosphorylation sites by site-directed mutagenesis using as backbones the wild type or FTDP-17 mutant R406W Tau. Pseudophosphorylated and corresponding control Tau proteins were expressed transiently in PC12 and CHO cells. We found that a single phosphorylation site alone had little influence on the biological activity of Tau, except Thr²¹², which, upon mutation to Glu in the R406W background, induced Tau aggregation in cells, suggesting phosphorylation at this site along with a modification on the C-terminal of the protein facilitates self-assembly of Tau. The expression of R406W Tau pseudophosphorylated at Thr²¹², Thr²³¹, and Ser²⁶² triggered caspase-3 activation in as much as 85% of the transfected cells, whereas the corresponding value for wild type pseudophosphorylated Tau was 30%. Cells transfected with pseudophosphorylated Tau became TUNEL-positive.     

Parametric Finite Element Analysis and Closed-formSolutions in Orthodontics

The goal and clinical relevance of this work was the development of closed formulas that are correct and simple enough for a fast decision making by the orthodontist in the daily praxis. This paper performs a parametric three-dimensional finite element linear analysis on a maxillary central incisor with a root of paraboloidal shape, which is subjected to typical orthodontic force-systems. Parameters of most importance, such as the tooth mobility in translation and in pure moment rotation including orthodontic centers, as well as the stresses inside the periodontal ligament are calculated for a large variety of over four hundred different couples of root lengths and root diameters around a nominal value. Regression analysis is afterwards performed and establishes closed-form solutions, which are also explained in terms of analytical strain energy and hydrostatic stress considerations within the periodontal ligament characterised by a small compressibility. The obtained expressions include both the root length as well as the root diameter.