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Lentil root statocytes show a strict structural polarity of their organelles with respect to the g vector. These cells are involved in the perception of gravity and are responsible for the orientation of the root. Actin filaments take part in the positioning of their organelles and could also be involved in the transduction of the gravitropic signal. A pre‐embedding immunogold silver technique was carried out with a monoclonal antibody in order to study the distribution of actin cytoskeleton in the statocytes at the electron microscopic level. Some areas were never labelled (cell wall, vacuole, nucleoplasm, mitochondria, starch grains of the amyloplasts) or very slightly labelled (stroma of the amyloplasts). The labelling was scattered in the cytoplasm always close to, or on the nuclear and amyloplast envelopes and the tonoplast. Associations of 2 to 6 dots in file were observed, but these short files were not oriented in one preferential direction. They corresponded to a maximum distance of 0.9 μm. This work demonstrated that each statocyte organelle was enmeshed in an actin web of short filaments arranged in different ways. The images obtained by rhodamine‐phalloidin staining were in accordance with those of immunogold labelling. The diffuse fluorescence of the cytoplasm could be explained by the fact that the meshes of the web should be narrow. The vicinity of actin and of the amyloplasts envelope could account for the movement of these organelles that was observed in spatial microgravity.

The authors explored the risks and benefits of repeated irrigation of Populus alba saplings with aqueous paper sludge (APS). Saplings were cultivated in pots of forest soil (3 L) in a greenhouse for 7 weeks and watered twice a week with differing concentrations of APS (0, 10, 20, 30, 50, 75,and 100 % v/v with deionized water). Plant growth and ecophysiological variables along with zinc and aluminum transfer were monitored. A stimulation of plant growth was observed with sludge treatments of 30 or 50 %, significantly correlated to APS input (r = 0.81). This may be explained by the easily available nitrogen as is shown with the positive correlation of CO2 assimilation and leaf nitrogen (r = 0.70). However, a significant reduction in plant growth was observed when treatments of 75 and 100 % of APS were administered, despite a high nutritional level (nitrogen and phosphorus). The study suggests that APS concentrations from 30 to 50 % may positively affect the growth of poplar saplings; however, the higher concentrations indicated a risk for plant growth and the environment.

Metabolic diseases, such as obesity, Type II diabetes and hepatic steatosis, are a significant public health concern affecting more than half a billion people worldwide. The prevalence of these diseases is constantly increasing in developed countries, affecting all age groups. The pathogenesis of metabolic diseases is complex and multifactorial. Inducer factors can either be genetic or linked to a sedentary lifestyle and/or consumption of high-fat and sugar diets. In 2002, a new concept of “environmental obesogens” emerged, suggesting that environmental chemicals could play an active role in the etiology of obesity. Bisphenol A (BPA), a xenoestrogen widely used in the plastic food packaging industry has been shown to affect many physiological functions and has been linked to reproductive, endocrine and metabolic disorders and cancer. Therefore, the widespread use of BPA during the last 30 years could have contributed to the increased incidence of metabolic diseases. BPA was banned in baby bottles in Canada in 2008 and in all food-oriented packaging in France from 1 January 2015. Since the BPA ban, substitutes with a similar structure and properties have been used by industrials even though their toxic potential is unknown. Bisphenol S has mainly replaced BPA in consumer products as reflected by the almost ubiquitous human exposure to this contaminant. This review focuses on the metabolic effects and targets of BPA and recent data, which suggest comparable effects of the structural analogs used as substitutes.

It has recently been documented that, compared to untransformed controls, the roots of oilseed rape (Brassica napus L. CV CrGC5) seedlings transformed by Agrobacterium rhizogenes A4 show a reduced gravitropic reaction (Legué et al. 1994, Physiol Plant 91: 559—566). After stimulation at 90°C or 135°, the transformed root tips curve, but never reach a vertical orientation. In the present study, we investigated the causes of reduced gravitropic bending observed in stimulated transformed root tips. First, we localized the gravitropic curvature in normal and in transformed roots after 1.5 h of stimulation. The cells involved in root curvature (target cells) corresponded at the cellular level to the apical part of the zone of increasing cell length. In transformed roots grown in the vertical position, these cells showed a reduction in cell length compared to controls. Because auxin is considered to be the gravitropic mediator, the response of normal and transformed roots to exogenous auxin was studied. Indole-3-acetic acid (IAA) was applied along the first 3 mm using resin beads loaded with the hormone. In comparison to normal roots, transformed roots showed reduced bending toward the bead at all points of bead application. Moreover, the cells which responded to IAA corresponded to the target cells involved in the gravitropic reaction. The level of endogenous IAA was lower in transformed roots. Thus, it was concluded that the modified behavior of transformed roots during gravitropic stimulation could be due to differences either in IAA levels or in reactivity of the target cells to the message from the cap.

The kinetics of the movement of statoliths in gravity-perceiving root cap cells of Lens culinaris L. and the force responsible for it have been analysed under 1 g and under microgravity conditions (S/MM-03 mission of Spacehab 1996). At the beginning of the experiment in space, the amyloplasts were grouped at the distal pole of the statocytes by a root-tip-directed 1-g centrifugal acceleration. The seedlings were then placed in microgravity for increasing periods of time (13, 29, 46 or 122 min) and chemically fixed. During the first 29 min of microgravity there were local displacements (mean velocity: 0.154 μm min-1) of some amyloplasts (first at the front of the group and then at the rear). Nevertheless, the group of amyloplasts tended to reconstitute. After 122 min in microgravity the bulk of amyloplasts had almost reached the proximal pole where further movement was blocked by the nucleus. After a longer period in microgravity (4 h; experiment carried out 1994 during the IML 2 mission) the statoliths reached a stable position due to the fact that they were stopped by the nucleus. The position was similar to that observed in roots grown continuously in microgravity. Treatment with cytochalasin D (CD) did not stop the movement of the amyloplasts but slowed down the velocity of their displacement (0.019 μm min-1). Initial movement patterns were the same as in control roots in water. Comparisons of mean velocities of amyloplast movements in roots in space and in inverted roots on earth showed that the force responsible for the movement in microgravity (Fc) was about 86% less (Fc = 0.016 pN) than the gravity force (Fg = 0.11 pN). Treatment with CD reduced Fc by two-thirds. The apparent viscosity of the statocyte cytoplasm was found to be 1 Pa s or 3.3 Pa s for control roots or CD treated roots, respectively. Brownian motion or elastic forces due to endoplasmic reticulum membranes do not cause the movement of the amyloplasts in microgravity. It concluded that the force transporting the statoliths caused by the actomyosin system.

From 1993 to 1995, more than 2000 of 0 + brown trout (Salmo trutta L.) were captured in a small brook in October and released after clipping the left pelvic fin. More than 1700 of them were also tagged with a small Passive Integrated Transponder (PIT) tag (11 mm long) implanted in the body cavity. Tagged juveniles were recaptured in May in the brook but also one year later in the river Oir, and continuously in a trap during spring downstream migration in the river Oir. The combined marking experiment (PIT tag and fin-clipping) carried out during the two first years showed an average transponder loss rate of 3.38% after seven months for 0+ juveniles tagged in October. Pelvic fin regeneration occurred at a average low rate of 2.37± during the same period. Futhermore, PIT tag showed no significant effect on growth, survival in 0+ juveniles (55 to 127 mm fork length), tagged in October 1995 and recaptured in May 1996. PIT tagging has been used to analyse brown trout movement inside the river. Recapture rate in the brook from tagged 0+ juveniles after seven months decreased while size increased. The medium sized juveniles migrated in the main system Oir and the largest ones out of the main river. Results showed (1) PIT tagging is a reliable technique to analyse the movement and population dynamics of brown trout by taking into account the individual life history, (2) recruitment of juvenile trout in the river depends on fish size.[PUBLICATION ABSTRACT]

This paper aims at disentangling the correlation between LDC debt and investment in the 1980's. I show that a large debt was not an unconditional predictor of low investment in the 1980's, nor was investment abnormally low, when compared to a \"financial-autarky\" rate, calculated in the text. I do find, however, that the actual service of the debt crowded out investment. For the rescheduling countries I show that 1 percent of GDP paid abroad reduced domestic investment by 0.3 percent of GDP. This is identical to the correlation between investment and foreign finance observed in the 1960's.

Space experiments have offered a unique opportunity to analyse the mechanism of gravisensing in plant roots. It has been shown that the strict structural polarity of statocytes observed on the ground is perturbed in microgravity: the amyloplasts move towards the proximal half of the cell and, at least in some cases, the nucleus becomes located further away from the (proximal) plasma membrane. It has thus been demonstrated that the amyloplasts do not move freely in the cytoplasm. Experiments using cytochalasin B (or D) have indicated that these organelles are attached to the actin network, probably by motor proteins. These findings have led to a new hypothesis on gravisensing the basis of which is that the tension in the actin filaments resulting from interaction with the statoliths would be transmitted to stretch-activated ion channels located in the plasma membrane (Sievers et al., 1991. In: Lloyd (ed) The cytoskeletal basis of plant growth and form, Academic Press, London New York, pp 169-182. Recently, it has been shown that the sensitivity of roots grown under 1 g conditions in orbit is less than that of roots grown in microgravity or under simulated weightlessness on clinostats. Since the location of the amyloplasts in microgravity is different from that in 1 g, the greater sensitivity observed could be due to different tensions in the actin network.

Many unit process models are available in the field of wastewater treatment. All of these models use their own notation, causing problems for documentation, implementation and connection of different models (using different sets of state variables). The main goal of this paper is to propose a new notational framework which allows unique and systematic naming of state variables and parameters of biokinetic models in the wastewater treatment field. The symbols are based on one main letter that gives a general description of the state variable or parameter and several subscript levels that provide greater specification. Only those levels that make the name unique within the model context are needed in creating the symbol. The paper describes specific problems encountered with the currently used notation, presents the proposed framework and provides additional practical examples. The overall result is a framework that can be used in whole plant modelling, which consists of different fields such as activated sludge, anaerobic digestion, sidestream treatment, membrane bioreactors, metabolic approaches, fate of micropollutants and biofilm processes. The main objective of this consensus building paper is to establish a consistent set of rules that can be applied to existing and most importantly, future models. Applying the proposed notation should make it easier for everyone active in the wastewater treatment field to read, write and review documents describing modelling projects.