scholarly journals Otolith Analyses Highlight Morpho-Functional Differences of Three Species of Mullet (Mugilidae) from Transitional Water

2021 ◽  
Vol 14 (1) ◽  
pp. 398 ◽  
Author(s):  
Claudio D’Iglio ◽  
Sabrina Natale ◽  
Marco Albano ◽  
Serena Savoca ◽  
Sergio Famulari ◽  
...  

Otoliths are used in taxonomy and ichthyology as they can provide a wide range of information about specimens. They are an essential tool to monitor the most sensitive species for a sustainable exploitation level. Despite the increasing use of sagittae in research, their inter- and intra-specific variability and eco-functionality are still poorly explored. This paper aims to investigate the inter- and intra-specific variability of Mugilidae sagittae using morphological and morphometrical analysis, as well as scanning electron microscopy and shape analysis. The sagittae of 74 specimens belonging to three different Mugilidae species, collected from a coastal lagoon, were analyzed to give an accurate description of their morphology, morphometry, shape and crystalline habits. The results highlighted the intra- and inter-specific variability of sagittae, showing morphometrical differences among species and slight differences between left and right sagittae in C. labrosus individuals. Moreover, SEM images showed a peculiar crystal organization, with several different crystal habits and polymorphs. This study provides an accurate description of sagittae in the studied species, deepening the knowledge on inter- and intra-specific variations and crystal habits and providing data which will be useful for future studies on otoliths. With this data, it will be possible to improve conservation and exploitation sustainability in sensitive habitats.

1998 ◽  
Vol 49 (1) ◽  
pp. 113
Author(s):  
B. N. Nagorcka ◽  
A. E. Dollin ◽  
A. J. Ringrose-Voase

A procedure for analysing digitised scanning electron microscope (SEM) images of impressions of sheep skin has been developed and tested. The new technique for measuring fibre densities and fibre bundles was applied to a small number of sheep from the Romney, Border Leicester, and Suffolk breeds, and in fine- and strong-woolled Merinos. Skin impressions were taken from small shaved areas of the skin, and fibres in digitised SEM images of the skin impressions were counted and assigned to bundles. Estimates were made of the density of epidermal follicles, the proportion of these which branch, the number of fibres (follicles) per bundle, and the proportion of skin left bare of follicles. An average distance between neighbouring epidermal follicles, Λ E, was also measured. Λ E was found to be correlated with fibre diameter. The total density of fibres (follicles) in the animals sampled ranged from 10 to 100 follicles/mm2 , and fibre diameter ranged from ~35 to ~15µm. Despite this wide range, all animals examined were observed to have derived (branched) follicles. The fraction of epidermal follicles which branched varied from ~0·15 to ~0·45, and the average number of fibres (follicles) per bundle ranged from 2·2 to 3·8. Λ E was used to calculate an indicator of the fraction of skin which is bare of follicles. This was found to be substantial, varying between 0·4 and 0·7. Measurements were also made using both serial transverse and serial longitudinal skin sections. The results obtained with the different techniques were compared.


2020 ◽  
Vol 89 (3) ◽  
pp. 282-323 ◽  
Author(s):  
Carolin Gut ◽  
Jasna Vukić ◽  
Radek Šanda ◽  
Timo Moritz ◽  
Bettina Reichenbacher

Gobies (Gobiidae + Oxudercidae) are among the largest groups of extant marine fishes. Fossils of gobies are abundant since the Miocene, and many species have been reported so far. However, delimitation of fossil goby species is challenging because molecular markers and diagnostic traits such as the disposition of sensory head papillae are lost. This study provides, for the first time, an actualistic framework for the identification of fossil goby species. We focus on characters that can in principle be recognized in fossils, and evaluate their ability to discriminate between extant goby species based on statistical analyses. Using 14 extant species of Gobius and seven species of Pomatoschistus, we conducted otolith morphometry, elliptic Fourier shape analysis of otoliths using the package ‘Momocs’, conventional fish morphometry, and meristic counts. In addition, the otoliths of all species are depicted based on SEM images and briefly described. Otolith Fourier shape analysis proved to be most efficient in discrimination of species within both genera, Gobius and Pomatoschistus. Several characters used in the other approaches also worked well, but the results were variable, and the relative taxonomic significance of particular variables tended to change depending on the species under consideration. We propose otolith shape analysis as a powerful tool to explore ancient goby species diversity when samples with abundant fossil otoliths are present. Overall, the herein presented data will greatly facilitate delimitation of fossil goby species in future studies, and will consequently shed new light on the evolution of goby diversity and biogeography through time.


Author(s):  
Y. Kokubo ◽  
W. H. Hardy ◽  
J. Dance ◽  
K. Jones

A color coded digital image processing is accomplished by using JEM100CX TEM SCAN and ORTEC’s LSI-11 computer based multi-channel analyzer (EEDS-II-System III) for image analysis and display. Color coding of the recorded image enables enhanced visualization of the image using mathematical techniques such as compression, gray scale expansion, gamma-processing, filtering, etc., without subjecting the sample to further electron beam irradiation once images have been stored in the memory.The powerful combination between a scanning electron microscope and computer is starting to be widely used 1) - 4) for the purpose of image processing and particle analysis. Especially, in scanning electron microscopy it is possible to get all information resulting from the interactions between the electron beam and specimen materials, by using different detectors for signals such as secondary electron, backscattered electrons, elastic scattered electrons, inelastic scattered electrons, un-scattered electrons, X-rays, etc., each of which contains specific information arising from their physical origin, study of a wide range of effects becomes possible.


2017 ◽  
Author(s):  
O Pong-Sik ◽  
Ryang Se-Hun ◽  
Sin Gum-Chol ◽  
Hwang Guk-Nam ◽  
yongson hong

We have studied porous anodic alumina template through the second anodic oxidation of preparation. Observing the morphology of nanoscale AAO template using scanning electron microscope (SEM), the results indicate that the pores are orderly paralleled arranged with uniform pore diameter, perpendicular to the template surface. A detailed study of the influence of different oxidation conditions, such as different type of electrolyte, concentration, voltage and temperature on the template of alumina and its electrochemical mechanism were performed. By changing the oxidation voltage, electrolyte type, concentration, pore diameter and template thickness can be altered in a wide range such that we can obtain the desired aspect ratio. <br>


Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 51
Author(s):  
Michela Relucenti ◽  
Giuseppe Familiari ◽  
Orlando Donfrancesco ◽  
Maurizio Taurino ◽  
Xiaobo Li ◽  
...  

Several imaging methodologies have been used in biofilm studies, contributing to deepening the knowledge on their structure. This review illustrates the most widely used microscopy techniques in biofilm investigations, focusing on traditional and innovative scanning electron microscopy techniques such as scanning electron microscopy (SEM), variable pressure SEM (VP-SEM), environmental SEM (ESEM), and the more recent ambiental SEM (ASEM), ending with the cutting edge Cryo-SEM and focused ion beam SEM (FIB SEM), highlighting the pros and cons of several methods with particular emphasis on conventional SEM and VP-SEM. As each technique has its own advantages and disadvantages, the choice of the most appropriate method must be done carefully, based on the specific aim of the study. The evaluation of the drug effects on biofilm requires imaging methods that show the most detailed ultrastructural features of the biofilm. In this kind of research, the use of scanning electron microscopy with customized protocols such as osmium tetroxide (OsO4), ruthenium red (RR), tannic acid (TA) staining, and ionic liquid (IL) treatment is unrivalled for its image quality, magnification, resolution, minimal sample loss, and actual sample structure preservation. The combined use of innovative SEM protocols and 3-D image analysis software will allow for quantitative data from SEM images to be extracted; in this way, data from images of samples that have undergone different antibiofilm treatments can be compared.


2021 ◽  
Vol 14 (3) ◽  
pp. 1-26
Author(s):  
Andrea Asperti ◽  
Stefano Dal Bianco

We provide a syllabification algorithm for the Divine Comedy using techniques from probabilistic and constraint programming. We particularly focus on the synalephe , addressed in terms of the "propensity" of a word to take part in a synalephe with adjacent words. We jointly provide an online vocabulary containing, for each word, information about its syllabification, the location of the tonic accent, and the aforementioned synalephe propensity, on the left and right sides. The algorithm is intrinsically nondeterministic, producing different possible syllabifications for each verse, with different likelihoods; metric constraints relative to accents on the 10th, 4th, and 6th syllables are used to further reduce the solution space. The most likely syllabification is hence returned as output. We believe that this work could be a major milestone for a lot of different investigations. From the point of view of digital humanities it opens new perspectives on computer-assisted analysis of digital sources, comprising automated detection of anomalous and problematic cases, metric clustering of verses and their categorization, or more foundational investigations addressing, e.g., the phonetic roles of consonants and vowels. From the point of view of text processing and deep learning, information about syllabification and the location of accents opens a wide range of exciting perspectives, from the possibility of automatic learning syllabification of words and verses to the improvement of generative models, aware of metric issues, and more respectful of the expected musicality.


2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
P. S. Bhupal Dev ◽  
Werner Rodejohann ◽  
Xun-Jie Xu ◽  
Yongchao Zhang

Abstract The P2 experiment aims at high-precision measurements of the parity-violating asymmetry in elastic electron-proton and electron-12C scatterings with longitudinally polarized electrons. We discuss here the sensitivity of P2 to new physics mediated by an additional neutral gauge boson Z′ of a new U(1)′ gauge symmetry. If the charge assignment of the U(1)′ is chiral, i.e., left- and right-handed fermions have different charges under U(1)′, additional parity-violation is induced directly. On the other hand, if the U(1)′ has a non-chiral charge assignment, additional parity-violation can be induced via mass or kinetic Z-Z′ mixing. By comparing the P2 sensitivity to existing constraints, we show that in both cases P2 has discovery potential over a wide range of Z′ mass. In particular, for chiral models, the P2 experiment can probe gauge couplings at the order of 10−5 when the Z′ boson is light, and heavy Z′ bosons up to 79 (90) TeV in the proton (12C) mode. For non-chiral models with mass mixing, the P2 experiment is sensitive to mass mixing angles smaller than roughly 10−4, depending on model details and gauge coupling magnitude.


Author(s):  
Nufar Sukenik ◽  
Laurice Tuller

AbstractStudies on the lexical semantic abilities of children with autism have yielded contradicting results. The aim of the current review was to explore studies that have specifically focused on the lexical semantic abilities of children with ASD and try to find an explanation for these contradictions. In the 32 studies reviewed, no single factor was found to affect lexical semantic skills, although children with broader linguistic impairment generally, but not universally, also showed impaired lexical semantic skills. The need for future studies with young ASD participants, with differing intellectual functioning, longitudinal studies, and studies assessing a wide range of language domains are discussed.


2008 ◽  
Vol 190 (18) ◽  
pp. 6111-6118 ◽  
Author(s):  
P. Rousseau ◽  
C. Loot ◽  
C. Turlan ◽  
S. Nolivos ◽  
M. Chandler

ABSTRACT IS911 is a bacterial insertion sequence composed of two consecutive overlapping open reading frames (ORFs [orfA and orfB]) encoding the transposase (OrfAB) as well as a regulatory protein (OrfA). These ORFs are bordered by terminal left and right inverted repeats (IRL and IRR, respectively) with several differences in nucleotide sequence. IS911 transposition is asymmetric: each end is cleaved on one strand to generate a free 3′-OH, which is then used as the nucleophile in attacking the opposite insertion sequence (IS) end to generate a free IS circle. This will be inserted into a new target site. We show here that the ends exhibit functional differences which, in vivo, may favor the use of one compared to the other during transposition. Electromobility shift assays showed that a truncated form of the transposase [OrfAB(1-149)] exhibits higher affinity for IRR than for IRL. While there was no detectable difference in IR activities during the early steps of transposition, IRR was more efficient during the final insertion steps. We show here that the differential activities between the two IRs correlate with the different affinities of OrfAB(1-149) for the IRs during assembly of the nucleoprotein complexes leading to transposition. We conclude that the two inverted repeats are not equivalent during IS911 transposition and that this asymmetry may intervene to determine the ordered assembly of the different protein-DNA complexes involved in the reaction.


2014 ◽  
Vol 887-888 ◽  
pp. 458-461
Author(s):  
Chang Qing Li ◽  
Kun Wang ◽  
Pei Jia Liu ◽  
Qi Ming

Porous silicon (PSi) was fabricated by using electrochemical anodic etching method. Then acid treatment and cathode reduction treatment were employed to improve the luminescence properties and stability of PSi material. Photoluminescence (PL) measurements and scanning electron microscope (SEM) were used to observe the luminescence properties and microstructure of samples, respectively. The results of PL measurements showed that the PL intensity and the stability of luminescence of samples after cathodic reduction and acid treatment were significantly improved. The SEM images showed that the porosity of PSi may be increased through the cathodic reduction treated.


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