scholarly journals Onychites from Polish Jura and Their Functional Morphology

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1207
Author(s):  
Przemysław Sztajner
Keyword(s):  
Organic Matter ◽  
Functional Morphology ◽  
Original Structure ◽  
Excellent Preservation ◽  
High Diversity

Onychites aff. barbatus is excessively rare in the Polish Jura. This paper describes a recent find from the basal middle Oxfordian. The specimen is preserved in a manner typical for other finds of this kind in platy limestones, i.e., as compressed and flattened imprints with remnants of carbonized organic matter. Excellent preservation of the surfaces enables a precise reconstruction of the original structure. Accordingly, I hypothesize on the attachment to soft parts and the function of the belemnite onychites. The high diversity of known onychites, especially from Europe (NW Tethys), indicates that they served a variety of purposes.

Functional significance of preserved color patterns of mollusks from the Gosport Sand (Eocene) of Alabama

1988 ◽  
Vol 62 (01) ◽  
pp. 83-87 ◽  
Author(s):  
Patricia H. Kelley ◽  
Charles T. Swann
Keyword(s):  
Functional Morphology ◽  
Functional Significance ◽  
Intraspecific Variability ◽  
Color Pattern ◽  
Color Patterns ◽  
Historical Factors ◽  
Life Mode ◽  
Molluscan Fauna ◽  
Excellent Preservation ◽  
Architectural Constraints

The excellent preservation of the molluscan fauna from the Gosport Sand (Eocene) at Little Stave Creek, Alabama, has made it possible to describe the preserved color patterns of 15 species. In this study the functional significance of these color patterns is tested in the context of the current adaptationist controversy. The pigment of the color pattern is thought to be a result of metabolic waste disposal. Therefore, the presence of the pigment is functional, although the patterns formed by the pigment may or may not have been adaptive. In this investigation the criteria proposed by Seilacher (1972) for testing the functionality of color patterns were applied to the Gosport fauna and the results compared with life mode as interpreted from knowledge of extant relatives and functional morphology. Using Seilacher's criteria of little ontogenetic and intraspecific variability, the color patterns appear to have been functional. However, the functional morphology studies indicate an infaunal life mode which would preclude functional color patterns. Particular color patterns are instead interpreted to be the result of historical factors, such as multiple adaptive peaks or random fixation of alleles, or of architectural constraints including possibly pleiotropy or allometry. The low variability of color patterns, which was noted within species and genera, suggests that color patterns may also serve a useful taxonomic purpose.

scholarly journals Isolation, identification and functional characterization of cultivable bacteria from Arabian Sea and Bay of Bengal water samples reveals high diversity

2020 ◽  
Author(s):  
Shriram N. Rajpathak ◽  
Yugandhara M. Patil ◽  
Roumik Banerjee ◽  
Asmita M. Khedkar ◽  
Pawan G. Mishra ◽  
...  
Keyword(s):  
Organic Matter ◽  
Bay Of Bengal ◽  
Arabian Sea ◽  
Functional Characterization ◽  
Culturable Bacteria ◽  
Carbohydrate Utilization ◽  
Cultivable Bacteria ◽  
High Diversity ◽  
Oxygen Minimum

AbstractThe oxygen minimum zone of the Arabian Sea (AS) and Bay of Bengal (BOB) is rich in organic matter and is an unusual niche. Bacteria present in the oceanic water play an important role in ecology since they are responsible for decomposing, mineralizing of organic matter and in elemental cycling like nitrogen, sulfur, phosphate. This study focuses on culturing bacteria from oxygen minimum zones (OMZ) and non-OMZ regions and their phylogenetic as well as the functional characterization. Genotypic characterization of the isolates using amplified rDNA based 16SrRNA sequencing grouped them into various phylogenetic groups such as alpha-proteobacteria, gamma-proteobacteria and unaffiliated bacteria. The cultivable bacterial assemblages encountered belonged to the genus Halomonas, Marinobacter, Idiomarina, Pshyctobacter and Pseudoalteromonas. Among the enzymatic activities, carbohydrate utilization activity was most predominant (100%) and microorganisms possessed amylase, cellulase, xylanase and chitinase. A large proportion of these bacteria (60%) were observed to be hydrocarbon consuming and many were resistant to ampicillin, chloramphenicol, kanamycin and streptomycin. The high diversity and high percentage of extracellular hydrolytic enzyme activities along with hydrocarbon degradation activity of the culturable bacteria reflects their important ecological role in oceanic biogeochemical cycling. Further assessment confirmed the presence of nitrogen reduction capability in these cultivable bacteria which highlights their importance in oceanic geochemical cycling.

Functional significance of preserved color patterns of mollusks from the Gosport Sand (Eocene) of Alabama

1988 ◽  
Vol 62 (1) ◽  
pp. 83-87 ◽  
Author(s):  
Patricia H. Kelley ◽  
Charles T. Swann
Keyword(s):  
Functional Morphology ◽  
Functional Significance ◽  
Intraspecific Variability ◽  
Color Pattern ◽  
Color Patterns ◽  
Historical Factors ◽  
Life Mode ◽  
Molluscan Fauna ◽  
Excellent Preservation ◽  
Architectural Constraints

The excellent preservation of the molluscan fauna from the Gosport Sand (Eocene) at Little Stave Creek, Alabama, has made it possible to describe the preserved color patterns of 15 species. In this study the functional significance of these color patterns is tested in the context of the current adaptationist controversy. The pigment of the color pattern is thought to be a result of metabolic waste disposal. Therefore, the presence of the pigment is functional, although the patterns formed by the pigment may or may not have been adaptive. In this investigation the criteria proposed by Seilacher (1972) for testing the functionality of color patterns were applied to the Gosport fauna and the results compared with life mode as interpreted from knowledge of extant relatives and functional morphology. Using Seilacher's criteria of little ontogenetic and intraspecific variability, the color patterns appear to have been functional. However, the functional morphology studies indicate an infaunal life mode which would preclude functional color patterns. Particular color patterns are instead interpreted to be the result of historical factors, such as multiple adaptive peaks or random fixation of alleles, or of architectural constraints including possibly pleiotropy or allometry. The low variability of color patterns, which was noted within species and genera, suggests that color patterns may also serve a useful taxonomic purpose.

scholarly journals Enzymatic Bioprospecting of Fungi Isolated from a Tropical Rainforest in Mexico

2021 ◽  
Vol 8 (1) ◽  
pp. 22
Author(s):  
Karla Peraza-Jiménez ◽  
Susana De la Rosa-García ◽  
José Javier Huijara-Vasconselos ◽  
Manuela Reyes-Estebanez ◽  
Sergio Gómez-Cornelio
Keyword(s):  
Organic Matter ◽  
Leaf Litter ◽  
Tropical Rainforest ◽  
Laccase Activity ◽  
Tropical Environment ◽  
Tropical Rainforests ◽  
Biotechnological Applications ◽  
Fusarium Spp ◽  
Daedalea Flavida ◽  
High Diversity

The humid tropical environment provides an ideal place for developing a high diversity of plants; this is why it is an interesting site for the enzymatic bioprospecting of fungi that are responsible for the recycling of organic matter in an efficient and accelerated way and whose enzymes could have multiple biotechnological applications. For this study, 1250 isolates of macroscopic and microscopic fungal morphotypes were collected from soil, leaf litter, and wood. One hundred and fifty strains (50 from each source) were selected for the enzymatic screening. From the first phase, 51 strains with positive activity for laccase, protease, amylase, xylanase, and lipase enzymes were evaluated, of which 20 were isolated from leaf litter, 18 from the soil, and 13 from wood. The 10 best strains were selected for the enzymatic quantification, considering the potency index and the production of at least two enzymes. High laccase activity was detected for Trametes villosa FE35 and Marasmius sp. CE25 (1179 and 710.66 U/mg, respectively), while Daedalea flavida PE47 showed laccase (521.85 U/mg) and protease activities (80.66 U/mg). Fusarium spp. PH79 and FS400 strains had amylase (14.0 U/mg, 49.23 U/mg) and xylanase activities (40.05 U/mg, 36.03 U/mg) respectively. These results confirm the enzymatic potential of fungi that inhabit little-explored tropical rainforests with applications in industry.

Effect of Impoundment and River Diversion on Profundal Macrobenthos of Southern Indian Lake Manitoba

1984 ◽  
Vol 41 (4) ◽  
pp. 638-648 ◽  
Author(s):  
Allen P. Wiens ◽  
David M. Rosenberg
Keyword(s):  
Organic Matter ◽  
Primary Production ◽  
Particulate Organic Matter ◽  
Standing Crop ◽  
Suspended Solids ◽  
Shoreline Erosion ◽  
Benthic Organism ◽  
River Diversion ◽  
Before And After ◽  
High Diversity

Profundal macrobenthos in Southern Indian Lake, Manitoba, were surveyed to determine effects of hydroelectric manipulations in 1972 (preimpoundment), 1977 (postimpoundment), and 1979 (postdiversion). Lakewide average standing crops increased following impoundment and decreased by 3 yr after impoundment. Regional changes in standing crops usually could be related to additions of nutrients leached from flooded vegetation, additions of particulate organic matter resulting from shoreline erosion, and changes in integral primary production and suspended solids concentrations before and after impoundment. Greater increases in standing crops of macrobenthos in shallower compared with deeper depth zones of the lake after flooding were attributed to preferential deposition of organic materials in the shallow areas of the lake. Mean standing crops of macrobenthos were higher in regions through which the Churchill River flowed than in regions isolated from the flow before and after impoundment. After diversion, greatest decreases in standing crops occurred in isolated regions, whereas those of regions in the flow declined much less or increased. Responses of the most abundant taxa of macrobenthos (Pontoporeia brevicornis grp., Chironomidae, Oligochaeta, Sphaeriidae) differed in many ways from those recorded for other new reservoirs. Pontoporeia brevicornis grp. remained the most abundant benthic organism, there was no evident succession of macrobenthic taxa, and a high diversity of profundal species was maintained. These results, together with the slight changes in standing crop observed after flooding, indicated only a marginal impact on macrobenthos caused by the low-level flooding of Southern Indian Lake.

ALKALINE CUPRIC OXIDE OXIDATION OF ROOTS AND ALKALINE-EXTRACTABLE ORGANIC MATTER OF CHERNOZEMIC SOILS

1979 ◽  
Vol 59 (1) ◽  
pp. 27-35 ◽  
Author(s):  
J. F. DORMAAR
Keyword(s):  
Organic Matter ◽  
Humic Substances ◽  
Ethyl Ether ◽  
Soluble Fraction ◽  
Cupric Oxide ◽  
Grass Species ◽  
Original Structure ◽  
Chromatographic Peak ◽  
Stipa Comata ◽  
Extractable Organic Matter

Alkaline cupric oxide oxidation was performed on roots of three grass species, on humic substances from three Chernozemic soils, and on three known compounds. The three grass species were Stipa comata Trin. & Rupr., Stipa spartea Trin. var. curtiseta Hitchc, and Festuca scabrella Torr., the three Chernozemic soils were Brown, Dark Brown and Black, and the three known compounds were vanillin, p-hydroxybenzaldehyde, and syringaldehyde. The intent of the study was to obtain a qualitative overview of the set of ethyl ether-soluble products. The gas chromatographic patterns were, therefore, qualitatively assessed and only some of the major peaks were tentatively identified. The ethyl ether-soluble fraction represented only up to 5.7% of the total root C. Most of the compounds identified in the root digests were also present in digests of the alkaline-soluble humic substances. There were quantitative differences for each chromatographic peak among root species, among time of sampling and growth location, and among extraction procedures of humic substances. The oxidation of the three known compounds in turn led to a number of compounds. The CuO-NaOH oxidation may thus cause alterations in similar compounds released from the original structure which will lead to either inflated or deflated yields of compounds that were part of the original structure.

scholarly journals Seasonal diet shift in a Tetragonopterinae (Oateichthyes, Characidae) from the Ubatiba river, RJ, Brazil

2003 ◽  
Vol 63 (1) ◽  
pp. 69-74 ◽  
Author(s):  
R. Mazzoni ◽  
C. F. Rezende
Keyword(s):  
Organic Matter ◽  
Aquatic Insects ◽  
Feeding Habits ◽  
Diet Shift ◽  
Life Stages ◽  
Wet Season ◽  
Feeding Resources ◽  
Important Shift ◽  
High Diversity ◽  
Omnivorous Diet

In the present study, we describe feeding habits of Deuterodon sp. from the Ubatiba River and explore if diet changes according to a temporal cycle of dry and wet seasons. We observed that Deuterodon sp. fed on an extremely high diversity of items ranging from organic matter, sediment (sand plus quartz parts), algae, seeds and leaves to animal organisms, such as, crustaceans, oligochaets and several life stages of terrestrial and aquatic insects, indicating an omnivorous diet. An important shift in the use of feeding resources was also registered; animal and vegetal items had alternated importance between both seasons. Allochthonous vs. autochthonous items analysis showed predominance of allochthonous items during dry season while no significant differences were registered during wet season.

Correction of the contrast transfer function to determine the radial density distribution of frozen-hydrated tobacco mosaic virus

1992 ◽  
Vol 50 (1) ◽  
pp. 536-537
Author(s):  
Michael F. Smith ◽  
John P. Langmore
Keyword(s):  
Transfer Function ◽  
Phase Contrast ◽  
Heavy Atom ◽  
Biological Molecules ◽  
Frequency Compensation ◽  
Contrast Transfer Function ◽  
High Background ◽  
Low Contrast ◽  
Radial Density Distribution ◽  
Excellent Preservation

The purpose of image reconstruction is to determine the mass densities within molecules by analysis of the intensities within images. Cryo-EM offers this possibility by virtue of the excellent preservation of internal structure without heavy atom staining. Cryo-EM images, however, have low contrast because of the similarity between the density of biological material and the density of vitreous ice. The images also contain a high background of inelastic scattering. To overcome the low signal and high background, cryo-images are typically recorded 1-3 μm underfocus to maximize phase contrast. Under those conditions the image intensities bear little resemblance to the object, due to the dependence of the contrast transfer function (CTF) upon spatial frequency. Compensation (i.e., correction) for the CTF is theoretically possible, but implementation has been rare. Despite numerous studies of molecules in ice, there has never been a quantitative evaluation of compensated images of biological molecules of known structure.

The Advantages of Cryotechniques: Application To Bioluminescent Cells

1990 ◽  
Vol 48 (1) ◽  
pp. 486-487
Author(s):  
Gisèle Nicolas ◽  
Jean-Marie Bassot ◽  
Marie-Thérèse Nicolas
Keyword(s):  
Endoplasmic Reticulum ◽  
Striated Muscle ◽  
Light Emission ◽  
Stable State ◽  
Freeze Substitution ◽  
Initial Step ◽  
Point Of Interest ◽  
Cell Components ◽  
Excellent Preservation ◽  
External Water

The use of fast-freeze fixation (FFF) followed by freeze-substitution (FS) brings substantial advantages which are due to the extreme rapidity of this fixation compared to the conventional one. The initial step, FFF, physically immobilizes most molecules and therefore arrests the biological reactions in a matter of milliseconds. The second step, FS, slowly removes the water content still in solid state and, at the same time, chemically fixes the other cell components in absence of external water. This procedure results in an excellent preservation of the ultrastructure, avoids osmotic artifacts,maintains in situ most soluble substances and keeps up a number of cell activities including antigenicities. Another point of interest is that the rapidity of the initial immobilization enables the capture of unstable structures which, otherwise, would slip towards a more stable state. When combined with electrophysiology, this technique arrests the ultrastructural modifications at a well defined state, allowing a precise timing of the events.We studied the epithelium of the elytra of the scale-worm, Harmothoe lunulata which has excitable, conductible and bioluminescent properties. The intracellular sites of the light emission are paracrystals of endoplasmic reticulum (PER), named photosomes (Fig.1). They are able to flash only when they are coupled with plasma membrane infoldings by dyadic or triadic junctions (Fig.2) basically similar to those of the striated muscle fibers. We have studied them before, during and after stimulation. FFF-FS showed that these complexes are labile structures able to diffentiate and dedifferentiate within milliseconds. Moreover, a transient network of endoplasmic reticulum was captured which we have named intermediate endoplasmic reticulum (IER) surrounding the PER (Fig.1). Numerous gap junctions are found in the membranous infoldings of the junctional complexes (Fig.3). When cryofractured, they cleave unusually (Fig.4-5). It is tempting to suggest that they play an important role in the conduction of the excitation.

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