Daily and annual shell growth in a long-lived freshwater bivalve as a proxy for winter snowpack

2021 ◽  
pp. 110346
Author(s):  
Tsuyoshi Watanabe ◽  
Mayumi Suzuki ◽  
Yoshihiko Komoto ◽  
Kotaro Shirai ◽  
Atsuko Yamazaki
Keyword(s):  
Shell Growth ◽  
Freshwater Bivalve

Field transplantation of a freshwater bivalve, Pyganodon grandis, across a metal contamination gradient. I. Temporal changes in metallothionein and metal (Cd, Cu, and Zn) concentrations in soft tissues

1995 ◽  
Vol 52 (4) ◽  
pp. 690-702 ◽  
Author(s):  
Y. Couillard ◽  
P. G. C. Campbell ◽  
A. Tessier ◽  
J. C. Auclair ◽  
J. Pellerin-Massicotte
Keyword(s):  
Soft Tissues ◽  
Shell Growth ◽  
Mining Area ◽  
Metal Exposure ◽  
Steady Increase ◽  
Freshwater Bivalve ◽  
Slow Increase ◽  
Metal Levels ◽  
Pyganodon Grandis ◽  
Over Time

To test the response of the freshwater bivalve Pyganodon grandis (formerly Anodonta grandis) to increased metal exposure in the field, we transferred specimens (8 cm length; 4–6 years old) from a less to a more contaminated lake in the mining area of Rouyn-Noranda, in northwestern Québec. The transplanted bivalves were maintained in open enclosures placed in the bottom sediments of the contaminated lake. Up to 16 individuals were removed from pairs of enclosures at times t = 0 (June 1990), 5, 14, 30, 60, 90, and 400 d; tissue concentrations of metallothionein (MT) and metals were monitored over time. Measurements on control molluscs enclosed in their lake of origin showed that enclosure per se had no apparent effect on tissue [MT] or tissue metal levels, but did decrease shell growth. Metallothionein levels in specimens transplanted to the more contaminated lake showed a slow but steady increase with time; in contrast, MT levels in the control populations showed only modest seasonal fluctuations. The increase in MT over time in the transplanted bivalves was closely correlated with a similar slow increase in soft tissue [Cd]. We conclude that MT in the freshwater bivalve P. grandis is a promising biochemical indicator of metal exposure.

Numerical analysis of local heat flux and thin-slab solidification in a CSP funnel-type mold with electromagnetic braking

2020 ◽  
Vol 117 (6) ◽  
pp. 602
Author(s):  
Heping Liu ◽  
Jianjun Zhang ◽  
Hongbiao Tao ◽  
Hui Zhang
Keyword(s):  
Heat Flux ◽  
Casting Speed ◽  
Shell Growth ◽  
Local Heat ◽  
Operating Conditions ◽  
Thin Slab ◽  
Wide Face ◽  
Slab Width ◽  
Steel Grades ◽  
Local Heat Flux

In this article, based on the actual monitored temperature data from mold copper plate with a dense thermocouple layout and the measured magnetic flux density values in a CSP thin-slab mold, the local heat flux and thin-slab solidification features in the funnel-type mold with electromagnetic braking are analyzed. The differences of local heat flux, fluid flow and solidified shell growth features between two steel grades of Q235B with carbon content of 0.19%C and DC01 of 0.03%C under varying operation conditions are discussed. The results show the maximum transverse local heat flux is near the meniscus region of over 0.3 m away from the center of the wide face, which corresponds to the upper flow circulation and the large turbulent kinetic energy in a CSP funnel-type mold. The increased slab width and low casting speed can reduce the fluctuation of the transverse local heat flux near the meniscus. There is a decreased transverse local heat flux in the center of the wide face after the solidified shell is pulled through the transition zone from the funnel-curve to the parallel-cure zone. In order to achieve similar metallurgical effects, the braking strength should increase with the increase of casting speed and slab width. Using the strong EMBr field in a lower casting speed might reverse the desired effects. There exist some differences of solidified shell thinning features for different steel grades in the range of the funnel opening region under the measured operating conditions, which may affect the optimization of the casting process in a CSP caster.

Phase-Dependent Shell Growth and Optical Properties of ZnSe/ZnS Core/Shell Nanorods

2021 ◽  
Author(s):  
Jiajia Ning ◽  
Yuan Xiong ◽  
Stephen V. Kershaw ◽  
Andrey L. Rogach
Keyword(s):  
Optical Properties ◽  
Shell Growth ◽  
Core Shell

Surface Chemistry and Quantum Dot Luminescence: Shell Growth, Atomistic Modification, and Beyond

2021 ◽  
pp. 977-984
Author(s):  
Forrest W. Eagle ◽  
Nayon Park ◽  
Melanie Cash ◽  
Brandi M. Cossairt
Keyword(s):  
Quantum Dot ◽  
Surface Chemistry ◽  
Shell Growth

scholarly journals Larval cryopreservation as new management tool for threatened clam fisheries

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
P. Heres ◽  
J. Troncoso ◽  
E. Paredes
Keyword(s):  
Shell Growth ◽  
Natural Populations ◽  
Ruditapes Philippinarum ◽  
Management Tool ◽  
Equilibration Time ◽  
Ruditapes Decussatus ◽  
Larval Stages ◽  
Long Term Storage ◽  
Declining Species ◽  
Conservation Of Endangered Species

AbstractCryopreservation is the only reliable method for long-term storage of biological material that guarantees genetic stability. This technique can be extremely useful for the conservation of endangered species and restock natural populations for declining species. Many factors have negatively affected the populations of high economical value shellfish in Spain and, as a result, many are declining or threatened nowadays. This study was focused on early-life stages of Venerupis corrugata, Ruditapes decussatus and Ruditapes philippinarum to develop successful protocols to enhance the conservation effort and sustainable shellfishery resources. Firstly, common cryoprotecting agents (CPAs) were tested to select the suitable permeable CPA attending to toxicity. Cryopreservation success using different combinations of CPA solutions, increasing equilibrium times and larval stages was evaluated attending to survival and shell growth at 2 days post-thawing. Older clam development stages were more tolerant to CPA toxicity, being ethylene-glycol (EG) and Propylene-glycol (PG) the least toxic CPAs. CPA solution containing EG yielded the highest post-thawing survival rate and the increase of equilibration time was not beneficial for clam larvae. Cryopreservation of trochophores yielded around 50% survivorship, whereas over 80% of cryopreserved D-larvae were able to recover after thawing.

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