Effects of Salinity on Gills’ Chloride Cells, Stress Indices and Gene Expression of Asian Seabass (Lates Calcarifer, Bloch, 1790)

A two-week research was carried-out to assess water salinity (WS) effects including 0, 15, 35 and 50‰ on osmoregulatory mechanisms and stress indices in Asian sea bass (34.4 g) juveniles. Except for fish reared at 50‰, in the other treatments gradually decreased to the prescribed WS during a 10-day period (-5‰ a day). After 10-day of acclimation period, fish reared at the prescribed WS for two weeks. Fish reared at 15 and 35‰ had higher chloride cell (CC) counts in the interlamellar region. The number of CC in the interlamellar region elevated with increment of WS up to 35‰, but they were pronouncedly reduced in 50‰ group . The diameter of CC in the interlamellar region was not affected by WS. The least nucleus diameter of CC in the interlamellar region was observed in fish reared at 15‰ (P < 0.05). The greatest and the least amounts of serum aspartate aminotransferase content were observed in fish reared at freshwater and 15‰, respectively. Fish reared at 35‰ had the highest serum sodium and potassium contents. Serum chloride content and total osmolality increased with increment of WS (P < 0.05). Serum cortisol and glucose contents gradually increased with elevation of WS up to 35‰, then their contents remarkably decreased. The relative expression of insulin like growth factor-1 in the liver of fish reared at 35‰ was strikingly higher than the other groups. The relative expression of HSP70 gene in fresh water group was pronouncedly elevated compared to other treatments. The relative expression of interleukin-1β in 15 and 35‰ groups was higher than the other groups; however, the relative expression of lysozyme gene in the liver of fish reared at fresh water was pronouncedly lower than the other treatments. The results of this study suggested rearing L. calcarifer at 15‰ closer to the isosmotic point and better provide its welfare.

Lamellar Crystal-Dominated Surface of Polymer Film Achieved by Melt Stretching-Induced Free Surface Crystallization

Lamellar crystal-dominated (LCD) surface holds great superiority and broad prospects for polymer surface engineering. The key to this is avoiding the formation of amorphous phase in the interlamellar region. Here...

New data on oribatid mites (Acari, Oribatida) of South Africa, with description of two new species of the family Oppiidae

The present study is based on oribatid mite material (Acari, Oribatida) collected from soil of Kaaimansgat estuary, Wilderness, Western Cape, South Africa in 2018. A list of identified taxa, including 41 species from 34 genera and 23 families, is presented; of these, nine species, three genera and one family are recorded in South Africa for the first time. Two new species belonging to the family Oppiidae are described: Kokoppia kaaimansensis sp. nov. differs from Kokoppia dudichi (Balogh, 1982) by the larger body size, the medium sized lamellar and interlamellar setae, the presence of muscle sigillae in the interlamellar region and the distinctly semi-oval epimeral borders IV and the absence of notogastral setae c; Paroppia neethlingi sp. nov. differs from other species of the genus by the localization of adanal lyrifissures in a direct apoanal position and the absence of epimeral borders IV. Revised generic diagnoses and identification keys to the known species of Kokoppia and Paroppia are presented.

A novel two-dimensional cobalt(II) complex composed of one-dimensional twisted pair-like chains: poly[[tetraaquabis(μ3-pyridine-2,5-dicarboxylato-κ4N,O2:O5:O5′)dicobalt(II)] dihydrate]

A novel neutral polymer, {[Co2(C7H3NO4)2(H2O)4]·2H2O}n, was hydrothermally synthesized using pyridine-2,5-dicarboxylate (2,5-PDC2−) as the organic linker. It features a two-dimensional layer structure constructed from one-dimensional {[Co(2,5-PDC)2]2−}nchains interlinked by [Co(H2O)4]+units. The two CoIIcations occupy special positions, sitting on inversion centres. Each 2,5-PDC2−anion chelates to one CoIIcationviathe pyridine N atom and an O atom of the adjacent carboxylate group, and links to two other CoIIcations in a bridging modeviathe O atoms of the other carboxylate group. In this way, the 2,5-PDC2−ligand connects three neighbouring CoIIcentres to form a two-dimensional network. The two-dimensional undulating layers are linked by extensive hydrogen bonds to form a three-dimensional supramolecular structure, with the uncoordinated solvent molecules occupying the interlamellar region.

Lamellar and Interlamellar Shear Compared Across Regions of the Annulus Fibrosus

Computational models of the intervertebral disc commonly use continuum descriptions that treat the annulus fibrosus as a single material rather than discretely modeling the lamellae and interlamellar interactions [1,2]. However, modeling the mechanics of individual lamellae and the interlamellar region can aid in the understanding of degenerative disc disease and its treatment. Previous work has demonstrated that fibrous connections between lamellae as well as bridges spanning across layers exist, but the mechanical contributions of these structures have largely remained uncharacterized [3]. Studying interlamellar shear mechanics may provide insights into the structure-function relationships of the annulus. The purpose of this study was to compare the mechanical shear in the interlamellar and lamellar regions, model the stress-stretch relationships of these areas utilizing a hyperelastic strain energy function, and compare the shear properties across multiple locations of the intervertebral disc.

Oribatella (Acari, Oribatida, Oribatellidae) of western North America

The oribatid mite genus Oribatella (Oribatellidae) includes 18 species known previously from North America. Herein, wedescribe 11 new Oribatella species from montane, subarctic, forest and prairie habitats in western North America: O. abmisp. nov., O. banksi sp. nov., O. ewingi sp. nov., O. heatherae sp. nov., O. manningensis sp. nov., O. maryae sp. nov., O.oregonensis sp. nov., O. parallelus sp. nov., O. pawnee sp. nov., O. sintranslamella and O. yukonensis sp. nov.Descriptions of two species (O. heatherae and O. pawnee) include some developmental instars. That of O. yukonensisincludes all instars; nymphs retain dorsocentral setae dm and dp, but the setal morphology changes between larva andnymphs. These immatures bear sclerotized areas on the hysterosoma. Adults of Oribatella oregonensis show distinctsexual dimorphism, with three notogastral setae arising from fused porose areas in the male. We provide new distributionrecords for Oribatella species previously known from North America, including O. arctica Thor, 1930, O. canadensisBehan-Pelletier and Eamer, 2010, O. jacoti Behan-Pelletier, 2011 and O. reticulatoides Hammer, 1955, and remark on O.anomola Grabowski, 1970. We clarify description of the octotaxic system and the interlamellar region in species ofOribatella and discuss variability in hysterosomal sclerotization and setation in immatures. Finally, we give a key to adults of the 29 species of Oribatella now known from North America.

Response of mucous cells of the gills of traíra (Hoplias malabaricus) and jeju (Hoplerythrinus unitaeniatus) (Teleostei: Erythrinidae) to hypo- and hyper-osmotic ion stress

The mucous cells (MC) of traíra, Hoplias malabaricus, and jeju, Hoplerythrinus unitaeniatus, two ecologically distinct erythrinid species, were analyzed in fish exposed to deionized (DW) and high ion concentration (NaCl and Ca2+) water (HIW) during 15 days to evaluate the MC responses to ion challenge. MCs are localized in the leading and trailing edge and, interlamellar region of the gill filament epithelium but, in H. unitaeniatus, they are also found in the breathing or lamellar epithelium. MC density is lower in H. malabaricus, the exclusively water-breathing fish, than in H. unitaeniatus, a facultative air-breathing fish. The transference to DW or HIW did not change the MC density and surface area, excepting in H. malabaricus, in the first day of exposure to DW. A single MC containing three types of glycoproteins (neutral, acidic and sulphated) was identified in the gill epithelium of both, H. malabaricus and H. unitaeniatus. The amount (based on the intensity of histochemistry reaction) of these glycoproteins differed between the species and were altered after exposure to DW and HIW showing little adjustments in the amount of mucosubstances in the MC of H. malabaricus and reduction of acidic and sulphated glycoproteins in H. unitaeniatus. The decreasing of these glycoproteins in H. unitaeniatus reduced the mucus protection against desiccation of gill tissue when change the ion concentration in water.