Carbonic anhydrase and Na/K-ATPase activities during the molt cycle of low salinity-reared white shrimp Litopenaeus vannamei

Changes in hemolymph osmolality, ion concentrations, and enzymatic activities of carbonic anhydrase (CA) in the gills and epidermal tissue, and Na/K-ATPase in the gills during the molt cycle were investigated in the white shrimp Litopenaeus vannamei. Hemolymph osmolality was high in the intermolt and early premolt stages, but started to decrease prior to ecdysis through to postmolt stages A and B. Changes in Na? and Cl- ion concentrations paralleled those in hemolymph osmolality. CA activity levels in the anterior and posterior gills were low at intermolt stage C0 and premolt stage D0, and maximum at premolt stage D3. In the epidermal tissue, activity was relatively high at intermolt stage C0 and premolt stage D0, but fluctuated towards premolt stage D3 and postmolt stage A. On the other hand, Na/K-ATPase activity in the gills decreased between intermolt stage C0 and premolt stage D2, but increased at premolt stage D3 and postmolt stage A. The changes in patterns of CA activity during the molt cycle suggest that CA may be involved in supplying counter-ions for Na? and Cl- uptake during molting. Branchial Na/K-ATPase appears to be involved in producing local osmotic gradients in order to support water influx across the epithelium

Development of two new sets of PCR primers for eDNA metabarcoding of brittle stars (Echinodermata, Ophiuroidea)

汲んだ水から深海生物の種類を判別 --世界初「クモヒトデメタバーコーティング」技術を開発--. 京都大学プレスリリース.Brittle stars (class Ophiuroidea) are marine invertebrates comprising approximately 2, 100 extant species, and are considered to constitute the most diverse taxon of the phylum Echinodermata. As a non-invasive method for monitoring biodiversity, we developed two new sets of PCR primers for metabarcoding environmental DNA (eDNA) from brittle stars. The new primer sets were designed to amplify 2 short regions of the mitochondrial 16S rRNA gene, comprising a conserved region (111–115 bp, 112 bp on average; named “16SOph1”) and a hyper-variable region (180–195 bp, 185 bp on average; named “16SOph2”) displaying interspecific variation. The performance of the primers was tested using eDNA obtained from two sources: a) rearing water of an 2.5 or 170 L aquarium tanks containing 15 brittle star species and b) from natural seawater collected around Misaki, the Pacific coast of central Japan, at depths ranging from shallow (2 m) to deep (> 200 m) sea. To build a reference library, we obtained 16S rRNA sequences of brittle star specimens collected from around Misaki and from similar depths in Japan, and sequences registered in International Nucleotide Sequence Database Collaboration. As a result of comparison of the obtained eDNA sequences with the reference library 37 (including cryptic species) and 26 brittle star species were detected with certain identities by 16SOph1 and 16SOph2 analyses, respectively. In shallow water, the number of species and reads other than the brittle stars detected with 16SOph1 was less than 10% of the total number. On the other hand, the number of brittle star species and reads detected with 16SOph2 was less than half of the total number, and the number of detected non-brittle star metazoan species ranged from 20 to 46 species across 6 to 8 phyla (only the reads at the “Tank” were less than 0.001%). The number of non-brittle star species and reads at 80 m was less than 10% with both of the primer sets. These findings suggest that 16SOph1 is specific to the brittle star and 16SOph2 is suitable for a variety of marine metazoans. It appears, however, that further optimization of primer sequences would still be necessary to avoid possible PCR dropouts from eDNA extracts. Moreover, a detailed elucidation of the brittle star fauna in the examined area, and the accurate identification of brittle star species in the current DNA databank is required

Minute distance obtained from pulmonary venous flow velocity using transesophageal pulsed Doppler echocardiography is related to cardiac output during cardiovascular surgery

Purpose. We studied the relationship between minute distance calculated from pulmonary venous flow (PVF) velocity tracing and cardiac output (CO)measured with thermodilution method in patients undergoing cardiovascular surgery. Methods. In 32 patients undergoing cardiovascular surgery, simultaneous measurements of hemodynamics including CO and transesophageal pulsed Doppler signals of PVF velocity were performed before and after surgical repair. Minute distance was calculated as the product of the heart rate and the sum of time-velocity integrals of PVF. Results. The minute distance after surgical intervention increased from 1121 ± 347 cm・sec-1to 1764 ± 538 cm・sec-1 (plt0.001 mean ± SD), while CO increased after surgical intervention from3.5 ± 0.9 L・min-1 to 5.3 ± 1.1 L・min-1. Simple linear regression analysis showed that minute distance was related with CO before and after surgical intervention (r=0.81 and r=0.76, respectively). The changes in minute distance were also related with those in CO (r=0.80). Conclusion. The present study demonstrated that minute distance obtained from the pulsed Doppler tracings of PVF velocity was related with CO during cardiovascular surgery in adults. These results suggest that the changes in CO could be estimated from minute distance in pulmonary vein

F-molding: A New Production Method for Largely Aspherical Mirrors of Cordierite

Cordierite is a rigid low thermal expansion coefficient ceramic equivalent to that of low thermal expansion glass but with voids due to forming with raw material powder. To overcome this problem, we propose Flexible Molding (F-molding) as our new fabrication method. With F-molding, the raw material powder is converted to liquid slurry, which is poured into a resin mold, solidified, and directly formed into near net design of a mirror. The mold prepared from F-molding is an effective tool for processing multiple volumes of identical structures such as those used in segmented mirror designs. We introduce details of our fabrication method in F-molding mirror and report its measurement results of optical performances with a 270mm diameter sample

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Not AvailableChanges in hemolymph osmolality, ion concentrations, and enzymatic activities of carbonic anhydrase (CA) in the gills and epidermal tissue, and Na/K-ATPase in the gills during the molt cycle were investigated in the white shrimp Litopenaeus vannamei. Hemolymph osmolality was high in the intermolt and early premolt stages, but started to decrease prior to ecdysis through to postmolt stages A and B. Changes in Na? and Cl- ion concentrations paralleled those in hemolymph osmolality. CA activity levels in the anterior and posterior gills were low at intermolt stage C0 and premolt stage D0, and maximum at premolt stage D3. In the epidermal tissue, activity was relatively high at intermolt stage C0 and premolt stage D0, but fluctuated towards premolt stage D3 and postmolt stage A. On the other hand, Na/K-ATPase activity in the gills decreased between intermolt stage C0 and premolt stage D2, but increased at premolt stage D3 and postmolt stage A. The changes in patterns of CA activity during the molt cycle suggest that CA may be involved in supplying counter-ions for Na? and Cl- uptake during molting. Branchial Na/K-ATPase appears to be involved in producing local osmotic gradients in order to support water influx across the epithelium.Not Availabl