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The advent of global warming events on already stressed organisms by pollution and loss of habitats raised concerns on the sustainability of local mussel populations. The purpose of this study was to study the physiology 6 commonly found species of freshwater mussels in the attempt to identify species at risk from global warming and pollution. The following species were examined for mass/length, energy metabolism, air survival and lipid peroxidation (LPO): Elliptio complanata (EC), Eurynia dilatata (ED), Pyganodon cataracta (PC), Pyganodon species (Psp), Lasmigona costata (LC) and Dreissena bugenis (DB). The data revealed that the estimated longevity of each species was associated with mussel mass, mitochondria electron transport (MET), temperature-dependent MET but negatively related with mitochondria levels in LPO and the colonization potential. The colonization potential was derived from the scaling of MET activity and mass, which confirmed that DB mussels are more invasive than the other species followed by Psp. Resistance to air emersion was significantly associated with longevity, mass and length and mitochondria LPO. Hence, organisms with low lifetimes, mass or length with high LPO are less able to survive for longer periods in air. In conclusion, longevity and air survival was positively associated with mass and energy metabolism but negatively with oxidative damage. This study proposes key markers in identifying species more at risk to contaminant stress, decreased water levels and global warming.

The advent of global warming events on already stressed organisms by pollution and loss of habitats raised concerns on the sustainability of local mussel populations. The purpose of this study was to study the physiology 6 commonly found species of freshwater mussels in the attempt to identify species at risk from global warming and pollution. The following species were examined for mass/length, energy metabolism, air survival and lipid peroxidation (LPO): Elliptio complanata (EC), Eurynia dilatata (ED), Pyganodon cataracta (PC), Pyganodon species (Psp), Lasmigona costata (LC) and Dreissena bugenis (DB). The data revealed that the estimated longevity of each species was associated with mussel mass, mitochondria electron transport (MET), temperature-dependent MET but negatively related with mitochondria levels in LPO and the colonization potential. The colonization potential was derived from the scaling of MET activity and mass, which confirmed that DB mussels are more invasive than the other species followed by Psp. Resistance to air emersion was significantly associated with longevity, mass and length and mitochondria LPO. Hence, organisms with low lifetimes, mass or length with high LPO are less able to survive for longer periods in air. In conclusion, longevity and air survival was positively associated with mass and energy metabolism but negatively with oxidative damage. This study proposes key markers in identifying species more at risk to contaminant stress, decreased water levels and global warming.

The cumulative effects of cyanobacterial blooms at sites impacted by urban or agricultural activity, could be detrimental to local freshwater mussels. The purpose of this study was to examine and compare the resulting toxicity using an upstream–downstream approach at four sites in the Yamaska River. Mussels were caged and placed at a site where cyanobacterial blooms were present, a site that receives municipal effluent from a small city of 75,000 inhabitants, and a site that drains a large agricultural area—plus a reference site in Lake Saint-Pierre (Quebec, Canada) for four months spanning the summer and fall (June to October). Effects on immunocompetence were monitored by testing for hemocyte counts, viability, phagocytosis, production of nitric oxide (NO), lysozyme (LY), reactive oxygen species (ROS), thiol contents, and inflammation induced by cyclooxygenase (COX) activity and glutathione S-transferase (GST) activity. Cyanobacterial blooms occurred at the target site only, reaching levels of 2.1 million cyanobacteria/L and 3 g/L of microcystin-LR in surface waters. Although most of the immune parameters were affected at the urban, agricultural and cyanobacteria sites, ROS and LY were the most responsive to cyanobacterial bloom, with a significantly greater response than the agriculture, urban and reference sites. The results also suggest that the effects of cyanobacterial blooms are spatially localized; they are not found at the downstream urban and agriculture sites in the Yamaska River., Invertebrate Survival Journal, Vol 15 No 1 (2018)

The purpose of this study was to examine the relationship between mitochondrial activity and gonad lipid stores in clams exposed to anthropogenic pollution at cold- and warm-water sites. The balance between energy expenses and energy reserves was measured by mitochondrial electron transport (MET) activity and lipid content in the gonad. The activity of malate dehydrogenase (MDH) was measured as an intermediary between energy production and the production of lipids in gonadal tissues. The results revealed that intertidal clam populations at warm-water sites under no source of pollution had less heavy metal content (Ag, As, Cr, Hg and Ni), lower MDH activity and temperature dependent MET than clams from cold-water sites. However, MDH activity measured at 6 o C was higher at the warm-water sites. Lipid peroxidation in the gonad was higher in clams from the coldwater sites. The impacts of pollution differed among the study sites, clams from cold-water sites having increased MDH activity, temperature-dependent MET activity, higher lipid content and DNA strand breaks; clams from the warm-water sites had increased temperature-dependent MDH activity and lower gonadal lipid reserves. A multiple regression analysis revealed that gonad lipid reserves were positively correlated with MDH activity and negatively correlated with its temperature-dependent activity, suggesting that increased temperature sensitivity was negatively related to gonad energy reserves. The data show that pollution increases temperature sensitivity at the MET level in clams in cold water, while temperature sensitivity in MDH activity was observed in clams from warm-water sites. Discriminate function analysis revealed that pollution stress shows a tendency to be closer to clams adapted to warmer temperatures. In conclusion, pollution could increase MDH activity in cold-adapted clams which can lead to increased lipid stores in the gonad, oxidative stress and genotoxicity while pollution seems to increase the temperature dependence in MET. In warm-adapted clams, temperature dependent MDH activity was higher by pollution with decreased lipid content in the gonad tissues which was independent of gonad maturation and size.

Municipal effluents are complex mixtures of compounds such as heavy metals, aromatic and aliphatic hydrocarbons, and micro-organisms and are released in aquatic ecosystems. The purpose of this study was to verify whether changes in metallothioneins (MT) were associated with the accumulation of labile metals in tissue of freshwater mussels exposed to the dispersion plume of a major municipal effluent. Mussels were placed in experimental cages deployed at sites 1.5 km upstream, 8 km downstream and 12 km downstream of the outfall of a major, primary-treated municipal effluent in the St. Lawrence River (Québec, Canada). Mussels were analysed for MT and labile zinc levels in their gonads, gills and digestive glands. Lipogenic enzyme (isocitrate and glucose-6-phosphate dehydrogenase) and arachidonic acid cyclooxygenase (COX) activities were also measured in gonad and gill tissues. Although MT was induced in all the tissues examined, the results showed that labile zinc levels were significantly reduced in gill and gonad tissues, with an increase observed only at the 12 km downstream site in the digestive gland. COX activity was readily induced in gills and gonads. Glucose-6-phosphate dehydrogenase activity was reduced at both downstream sites, but isocitrate dehydrogenase activity was significantly induced at the farthest (12 km) site. Analysis of covariance revealed that MT levels in gills were more influenced by COX activity than with distance in the dispersion plume and was negatively correlated with labile zinc levels. In conclusion, MT induction was inversely related to the levels of labile zinc but positively so with the inflammation biomarker COX. Hence, the induction of MT in mussels exposed to the municipal effluent of a large city appears to be associated with either inflammatory processes or as compensation for the loss of labile essential metals. We propose that the simple and complimentary parameters of labile zinc and COX evaluations be used to link MT induction with divalent heavy metal exposure in environmental studies dealing with various type of contaminants in such complex contaminant mixture effluents.

Using a series push-pull SiP modulator at 1310 nm, transmission using PAM-4 at 53.5 GBaud over 10 km of SMF-28 fiber is realized at a BER of 3.6x10 -3 .

TeraXion started silicon photonics activities aiming at developing building blocks for new products and customized solutions. Passive and active devices have been developed including MMI couplers, power splitters, Bragg grating filters, high responsivity photodetectors, high speed modulators and variable optical attenuators. Packaging solutions including fiber attachment and hybrid integration using flip-chip were also developed. More specifically, a compact packaged integrated coherent receiver has been realized. Good performances were obtained as demonstrated by our system tests results showing transmission up to 4800 km with BER below hard FEC threshold. The package size is small but still limited by the electrical interface. Migrating to more compact RF interface would allow realizing the full benefit of this technology.

A coherent receiver based on silicon photonics is presented. Its performance is confirmed at 112 Gb/s with PM-QPSK modulation at 28 Gbaud up to 4800 km and at 224 Gb/s with PM-16QAM up to 640 km. The packaged core has very compact dimensions of 6mm×8mm.

A coherent receiver based on silicon photonics is presented. Its performance is confirmed by single-channel and WDM transmission tests with PM-QPSK modulation at 28 Gbaud up to 4800 km. The packaged core is very compact with dimensions of 6 mm × 8 mm.

The release of treated municipal wastewaters to the aquatic environment raises concern about the health impacts on local resident invertebrates such as mussels. The purpose of this study was to examine the immunotoxicity of two types of treated municipal effluents—physico-chemical treated and physico-chemical with additional ozonation—to freshwater mussels. Immunocompetence was followed by tracking changes in hemocyte viability, adherence, phagocytosis, vitellogenin (Vtg)-like proteins and the pro-inflammatory precursors nitric oxide (NOx) production and arachidonate cyclo-oxygenase (COX) activity. The study results revealed that following a two-week continuous-flow exposure to the effluents, a reduction in hemocyte viability, adherence, NOx and COX activities was observed. Vtg like proteins were also increased, highlighting the estrogenic nature of the effluents. A significant correlation was found between Vtg-like proteins and the phagocytic efficiency index (r=0.34; p

The contamination of the benthic environment poses a threat to long-lived sessile organisms such as clams. The purpose of this study was to investigate metal contamination in tissues and changes in metallothioneins (MT) in respect to its redox status in Mya arenaria clams collected at three polluted sites. The phosphorylation state of MT was also investigated to determine whether this state is changed in clams collected at heavy-metal contaminated site and its involvement in cytoprotective signaling during stress contamination. The results show that clams collected at least one of the three polluted sites presented significantly higher concentrations of silver (Ag), arsenic (As), cobalt (Co), copper (Cu), mercury (Hg), nickel (Ni), tin (Sn) and lead (Pb) in tissues. In the visceral tissue, total MT levels and the reduced, metal-binding form of the protein were significantly induced at the sites. The phosphorylation of MT and mitochondrial activity, as determined by electron transport and cytochrome c oxidase activities, were also significantly reduced at the contaminated sites. Reduced phosphate levels in MT were negatively correlated with total MT levels, suggesting that decreased phosphorylation was involved in kinase-mediated signaling during cellular stress and could possibly alter the protein’s affinity to confer cytoprotection against heavy metal contamination. These preliminary investigations revealed that the phosphorylation state could change in polluted environment and provide some clues on the modulation of binding affinities during heavy-metal and oxidative stress in clams.

Municipal effluents are complex mixtures of compounds such as heavy metals, aromatic and aliphatic hydrocarbons, and micro-organisms and are released in aquatic ecosystems. The purpose of this study was to verify whether changes in metallothioneins (MT) were associated with the accumulation of labile metals in tissue of freshwater mussels exposed to the dispersion plume of a major municipal effluent. Mussels were placed in experimental cages deployed at sites 1.5 km upstream, 8 km downstream and 12 km downstream of the outfall of a major, primary-treated municipal effluent in the St. Lawrence River (Québec, Canada). Mussels were analysed for MT and labile zinc levels in their gonads, gills and digestive glands. Lipogenic enzyme (isocitrate and glucose-6-phosphate dehydrogenase) and arachidonic acid cyclooxygenase (COX) activities were also measured in gonad and gill tissues. Although MT was induced in all the tissues examined, the results showed that labile zinc levels were significantly reduced in gill and gonad tissues, with an increase observed only at the 12 km downstream site in the digestive gland. COX activity was readily induced in gills and gonads. Glucose-6-phosphate dehydrogenase activity was reduced at both downstream sites, but isocitrate dehydrogenase activity was significantly induced at the farthest (12 km) site. Analysis of covariance revealed that MT levels in gills were more influenced by COX activity than with distance in the dispersion plume and was negatively correlated with labile zinc levels. In conclusion, MT induction was inversely related to the levels of labile zinc but positively so with the inflammation biomarker COX. Hence, the induction of MT in mussels exposed to the municipal effluent of a large city appears to be associated with either inflammatory processes or as compensation for the loss of labile essential metals. We propose that the simple and complimentary parameters of labile zinc and COX evaluations be used to link MT induction with divalent heavy metal exposure in environmental studies dealing with various type of contaminants in such complex contaminant mixture effluents.

Ten 56-d-old, 15-kg barrows were surgically fitted with a postvalvular T-cecum cannula at the ileo-cecal junction to evaluate the effect of microbial phytase on apparent and true ileal AA digestibility and N utilization. A semipurified cornstarch- and soybean meal-based diet was formulated to contain 3.4 Mcal of DE/kg, 17.0% CP, 0.8% Ca, and 0.6% P but had a low phytate-P concentration (0.13%; all on an as-fed basis). Chromic oxide and dysprosium chloride were used as indigestible markers. The basal diet was supplemented with 0 or 1,000 phytase units/kg of microbial phytase. Postprandial plasma urea N and alpha-amino N concentrations, excretion of Ca, P, and N in feces and urine, and ileal AA digestibilities were determined 3 times at 4-wk intervals beginning at 70 d of age. The homoarginine (HA) method was used to determine endogenous AA flow by replacing 50% of the basal protein with guanidinated protein. Microbial phytase had no effect on apparent ileal digestibility (AID) or on true ileal digestibilities of N and most AA but did increase AID for arginine (P = 0.006) and methionine (P = 0.037). However, in HA diets, phytase increased the AID of CP (P = 0.01) and several AA. Addition of microbial phytase had no effect on the postprandial alpha-amino N concentrations in plasma but increased overall plasma urea N concentrations (P = 0.035). Barrows fed phytase-supplemented diets had decreased P in feces (P = 0.003) and greater P in urine (P = 0.001) but comparable total P excretion compared with barrows fed no phytase-supplemented diets. In conclusion, the addition of phytase to a semi-purified soybean meal-based diet did not affect the AID of several AA. In addition, differences between the basal and HA diets in N digestibilities indicated that that guanidination may limit the use of the HA method in determining endogenous protein losses.

A spatial and temporal survey of six sites in the Saguenay Fjord and of one adjacent site in the St. Lawrence River estuary (Quebec, Canada) was undertaken to study the possible effects of anthropogenic contaminant input on soft-shell clam (Mya arenaria) populations. Bivalve sampling sites were selected because they reflected a range of areas representative of either no known (or apparent) pollution sources or of areas potentially influenced by different gradients and types of contamination sources. The most upstream site selected in the Saguenay Fjord, nearest to a highly populated and industrialized sector, and the most downstream site, near its mouth with the St. Lawrence River estuary, spanned a distance of some 70 km and encompassed the entire intertidal area suitable for Mya arenaria habitat. To measure effects in collected animals, we used a comprehensive battery of biomarkers composed of metallothionein-like proteins (MT), 7-ethoxyresorufin O-deethylase activity (EROD), DNA damage (DD), lipid peroxidation (LPO), vitellinlike proteins (Vn), phagocytosis (PHAG), nonspecific esterase (NspE) activity, and condition factor (weight-to-length ratio of clams). Vn, PHAG, DD, and NspE biomarkers were assayed in hemolymph (or hemocytes), whereas others (MT, EROD, LPO) were determined in the digestive gland. Whole-tissue metal content was also quantified in clams collected in the spatial survey. The spatial survey conducted in June 1997 showed significant effects at all sites, and principal component analysis indicated in addition that the more important responses were linked to the MT, LPO, and NspE biomarkers. Clams collected from sites closest to the upstream reaches of the fjord generally displayed higher levels of tissue metals (cadmium, manganese), as well as greater responses of NspE activity, MT, LPO, and PHAG. Animals collected from sites influenced by municipal wastewaters had higher levels of Vn, suggesting the presence of environmental estrogens. The results of the temporal survey (six monthly samplings of clams at three sites from May through October, 1997) showed that the bivalve reproductive cycle (vitellogenesis and spawning) can modulate the expression of several biomarkers. Vn levels, for example, were positively correlated with DD and EROD and negatively correlated with MT, suggesting that reproduction can influence the susceptibility of clams to some contaminants. Discrimination analysis over the 6 months of sampling revealed that the mean value of the discriminant function changed significantly over time, suggesting important changes in the relative contribution of each biomarker. In short, this study has provided evidence that clam populations in the Saguenay Fjord are impacted by multiple sources of contamination whose effects can be modulated by reproduction.

Immune function in bivalves can be adversely affected by long-term exposure to environmental contaminants. Investigating alterations in immunity can therefore yield relevant information about the relationship between exposure to environmental contaminants and susceptibility to infectious diseases. We have developed a rapid, cost-effective, and miniaturized immunocompetence assay to evaluate the phagocytic activity, viability, and concentration of hemocytes in freshwater and marine bivalves. Preliminary experiments were performed to optimize various aspects of the assay including 1) the time required for adherence of hemocytes to polystyrene microplate wells, 2) the time required for internalization of fluorescent bacteria, 3) the ratio of hemocytes to fluorescent bacteria in relation to phagocytosis, 4) hemolymph plasma requirements, and 5) the elimination of fluorescence from (noninternalized) bacteria adhering to the external surface of hemocytes. The results of these experiments showed the optimal adherence time for hemocytes in microplate wells to be 1 h, that phagocytosis required at least 2 h of contact with fluorescently labeled E. coli cells, that the number of fluorescent E. coli cells had a positive effect on phagocytic activity, that at least 2.5 million cells/mL were required to measure a significant intake, and that a linear increase in uptake of bacteria (R = 0.91; p0.01) could be obtained with concentrations of up to 1.3 x 10(6) hemocytes/mL. Afterward, the assay was used in two field studies to identify sites having the potential to affect the immunocompetence of bivalves. The first study was conducted on Mya arenaria clams collected at selected contaminated sites in the Saguenay River (Quebec, Canada), and the second examined Elliptio complanata freshwater bivalves that had been exposed to a municipal effluent plume in the St. Lawrence River (Quebec, Canada). In the Saguenay River field study a significant increase in phagocytosis was observed at sites closest to polluted areas. Phagocytotic activity varied over time and was highest during the warmest months (June, July, and August), closely paralleling the spawning period of Mya arenaria clams. In contrast, a drop in phagocytic activity was observed in Elliptio complanata mussels exposed to surface water 4 km downstream of a major municipal effluent plume, with a concomitant increase in the number of hemocytes in the hemolymph. It appears that both immunosuppressive and immunostimulative effects are likely to occur in the field and that responses will be influenced by the type and intensity of contaminants at play.

The toxicological effects of a primary-treated municipal effluent plume were investigated in two species of freshwater mussels, Elliptio complanata and Dreissena polymorpha, exposed for 62 days at sites upstream and downstream of an effluent outfall in the St. Lawrence River (Quebec, Canada). Levels of metallothioneins (MT), cytochrome P4501A1 activity, DNA damage, total lipids, relative levels of vitellins, and phagocytic activity (in E. complanata hemocytes) were determined after the exposure period. A parallel analysis measured heavy metals and coprostanol in mussel tissues. The results show that significant levels of coprostanol and some metals (specifically, Cu, Hg, Sb, Se, and Zn) had accumulated in mussels caged 5 km downstream of the effluent plume. Mixed-function oxidase activity, MT in gills, total lipids, DNA damage (in D. polymorpha only), and total hemolymph bacteria (in E. complanata only) had increased in these mussels, while levels of total cadmium (Cd), MT in digestive glands or whole soft tissues, phagocytic activity, and DNA damage in the digestive gland (in E. complanata only) were diminished. The exposure of mussels to surface waters contaminated by a municipal effluent led to many stress responses, depending on both the tissues and the species being examined.

Estrogens play a major role in the sexual differentiation, gonad development, and oocyte growth of most oviparous organisms. They also stimulate vitellogenesis, the formation of high-density glycolipophosphoprotein that serves as an energy source for the developing embryo. Surface waters from the St. Lawrence River, obtained in the vicinity of an urban area (Montreal, Quebec, Canada), were studied with respect to their estrogenic potential to the freshwater mussel Elliptio complanata. Estrogenicity was measured in water extracts by means of a competitive assay of estradiol binding to cytosolic proteins and by the vitellin-inducing ability of mussel hemolymph following direct extract injection. Surface-water samples drawn downstream of a municipal outfall plume and in a river draining a large farming and agricultural area had high levels of total and fecal coliform bacteria. High levels of estrogen competitors were also found and were able to induce vitellins in injected mussels. Moreover, the estrogen-competing potential of the extracts was found to be significantly correlated with total and fecal coliform bacteria (R = 0.9, p0.01) and with the levels of vitellins in the hemolymph (R = 0.62, p = 0.03). The results indicate that water samples drawn from within the municipal effluent plume and from a river draining an agricultural area are estrogenic to freshwater mussels. Thus, the environmental inputs of estrogens are likely to be associated with human sewage and pesticide products.

Some individuals stand out among their peers because of their remarkable abilities; they are called gifted or talented. What do these two terms mean? How many can be labeled gifted or talented? Are some youngsters much more gifted/talented than others? Are they more at risk developmentally than their average ability peers? What are their major educational needs, and how do school systems answer these needs? These are the major themes covered by this brief overview of a field traditionally named Gifted Education.

We have searched for amyloid substance in 41 consecutive samples of tissue taken during laminectomies performed to relieve spinal canal stenoses. We also evaluated the relation between the occurrence of deposits and the age of patients.Tissue sections were stained with Congo red; positive areas had to show green dichroism under polarized light.Small amyloid deposits were found in fibrous and fibro-elastic (ligamentum flavum) tissues in 14 subjects (34%). After age 60, the frequency was close to 50%. It reached 58% in those aged 70 or over. Our 3 patients aged 80 or more all had deposits. There was also a relation between age and importance of the infiltration. Both sexes appeared evenly involved. Systemic amyloidosis (multiple myeloma) was demonstrated in a single patient. In this case infiltration was slightly more abundant and exceeded ligamentary structures, also involving vascular walls.Small amyloid deposits were frequent in our material. Their presence and their abundance were closely related to the age of patients. Rarely, a more important infiltration, exceeding ligamentary structures will perhaps suggest a systemic form of amyloidosis. A few other rare amyloid conditions (amyloidosis associated with prolonged dialysis, amyloid tumour) have been reported to induce spinal canal stenosis. The occurrence of amyloid in vertebral ligaments of non-stenosed elderly persons is not documented; it may represent a new localization of senile amyloidosis.

We report herein eight cases of microcystic meningiomas. This unusual variant was originally described by Masson, who labeled it "humid." Grossly, tumors were usually soft, with occasionally a glistening cut surface. Two tumors were cystic and three invaded bone structures. By light microscopy, tumor cells were stellate, with long processes delimitating clear spaces. Whorls were found in all tumors. Intracytoplasmic glycogen, fatty droplets, and phosphotungstic acid-hematoxylin-positive fibrils were sometimes seen. Tumor cells, however, were all negative with the peroxidase-antiperoxidase technique for glial fibrillary acidic protein. Mitoses, hemorrhages, and necrosis were absent. By electron microscopy, interdigitations of cytoplasmic processes and desmosomes were found. The large extracellular spaces were filled with a finely granular substance intermingled with fibrils and collagenic fibers. The clinical and morphological findings point toward a benign course. We also discuss the differential diagnosis and the pathogenesis.

The purpose of this chapter is to outline a framework of values for Giftedness and Talent Education (GTE). We begin by discussing the functions of education and the issue of purpose in educating the gifted and talented. We then address the meaning of values and their role in guiding research and practice. Our discussion is centered around five pairs of fundamental values: wisdom and truth, beauty and aesthetics, compassion and cooperation, freedom and autonomy, and equity and justice. We conclude by proposing the integration of the different functions of education as a fundamental endeavor for understanding the purpose of education for the gifted and talented. info:eu-repo/semantics/acceptedVersion