The structure of the spine of the spur dogfish (Squalus Acanthias L.) and its use for age determination

Author(s):  
M. J. Holden ◽  
P. S. Meadows

SUMMARYThe external and internal structure of the spines of Squalus acanthias are described. Internally the spines consist of a series of dentine cones laid down one within the other. This series is reflected in the external structure by bands of pigment associated with ridges of enamel. The latter are proved to be annual.The use of the spines for age determination is discussed and the growth parameters and growth curves calculated. The results obtained differ from those of previous authors, whose work is critically discussed.

2019 ◽  
Vol 44 ◽  
pp. 31-46
Author(s):  
Andrej Ryčkov

A thorough analysis of approximately one hundred unpublished and about seventy published letters written by Lithuanian noblemen and the Grand Duke of Lithuania led to a conclusion that there were three distinct types of letters. They represent correspondence between socially unequal as well as equal individuals. The external structure of a letter does not indicate the social differences between the addresser and the addressee. On the one hand, the external structure of a letter did not represent the addressers themselves; first of all, it was relevant for the intermediaries who confirmed the authenticity of the letters, registered the correspondence, and handed in the letters. On the other hand, the format of the seal is not a reliable indicator as well. The Lithuanian nobility, when communicating amongst themselves, sealed their letters with signets, while in correspondences with foreign countries they normally used larger seals. The Salutation (Latin: salutatio) is the element of a letter’s internal structure that is essential for understanding the power and status relation between an addresser and an addressee. Only “partners” of equal status informed each other on their health conditions or asked about each other’s well-being.


2019 ◽  
pp. 23-31 ◽  
Author(s):  
George N. Hotos

Growth and mortality of L. aurata (Risso,1810) were estimated in the lagoon of Klisova-Messolonghi (W. Greece), based on age estimation from scale readings of a total of 1048 individuals, ranging between 10 and 59 cm in total length (TL). Age determination revealed nine age classes (0+ to 8+). Maximum age was found to be 8 years for females and 6 years for males respectively. The growth pattern of L. aurata exhibited allometry (b=3.26). The species seems to achieve 34% of its growth during the first year; thereafter the annual growth rate drops. Both sexes presented similar von Bertalanffy growth curves. The von Bertalanffy growth function for the estimated total length-at-age was found Lt = 70.78 [1 - e -0.129(t+1.345)] for the combined sexes. Otolith weight, length and width were tested and they were found to be very good predictors for age. Between the present L. aurata growth parameters and those of other Mediterranean, Caspian and Atlantic Sea for the same species, there were found significant differences in its growth parameters. The total (Z) and natural (M) mortality rate was found to be 0.54 years-1 and 0.33 years-1 respectively. The estimated exploitation rate was found to be E=0.395 which suggests that the existing fishing pressure on L. aurata is rather moderate in the investigated region.


The Condor ◽  
2000 ◽  
Vol 102 (1) ◽  
pp. 216-219
Author(s):  
Beatriz E. Arroyo ◽  
Thomas DeCornulier ◽  
Vincent Bretagnolle

Abstract We studied plumage patterns of known-sex nestling and juvenile Short-eared Owls (Asio flammeus) to develop a sexing technique for nestlings in the field. Markings on the secondaries varied according to sex, and differences were apparent from about 10–15 days of age. We also provide aging formulas based on mass for nestlings up to 15 days of age and on wing length for nestlings older than that age. Finally, we evaluate growth parameters according to sex. The asymptotes of body mass, wing length, and tarsus length growth curves were higher in females than males. The inflexion point was attained earlier by males than by females.


1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.


2021 ◽  
Vol 12 (2) ◽  
pp. 480-490
Author(s):  
Ahsanul Salehin ◽  
Ramesh Raj Puri ◽  
Md Hafizur Rahman Hafiz ◽  
Kazuhito Itoh

Colonization of a biofertilizer Bacillus sp. OYK strain, which was isolated from a soil, was compared with three rhizospheric and endophytic Bacillus sp. strains to evaluate the colonization potential of the Bacillus sp. strains with a different origin. Surface-sterilized seeds of tomato (Solanum lycopersicum L. cv. Chika) were sown in the sterilized vermiculite, and four Bacillus sp. strains were each inoculated onto the seed zone. After cultivation in a phytotron, plant growth parameters and populations of the inoculants in the root, shoot, and rhizosphere were determined. In addition, effects of co-inoculation and time interval inoculation of Bacillus sp. F-33 with the other endophytes were examined. All Bacillus sp. strains promoted plant growth except for Bacillus sp. RF-37, and populations of the rhizospheric and endophytic Bacillus sp. strains were 1.4–2.8 orders higher in the tomato plant than that of Bacillus sp. OYK. The plant growth promotion by Bacillus sp. F-33 was reduced by co-inoculation with the other endophytic strains: Klebsiella sp. Sal 1, Enterobacter sp. Sal 3, and Herbaspirillum sp. Sal 6., though the population of Bacillus sp. F-33 maintained or slightly decreased. When Klebsiella sp. Sal 1 was inoculated after Bacillus sp. F-33, the plant growth-promoting effects by Bacillus sp. F-33 were reduced without a reduction of its population, while when Bacillus sp. F-33 was inoculated after Klebsiella sp. Sal 1, the effects were increased in spite of the reduction of its population. Klebsiella sp. Sal 1 colonized dominantly under both conditions. The higher population of rhizospheric and endophytic Bacillus sp. in the plant suggests the importance of the origin of the strains for their colonization. The plant growth promotion and colonization potentials were independently affected by the co-existing microorganisms.


1956 ◽  
Vol 2 (4) ◽  
pp. 305-312 ◽  
Author(s):  
E. W. Dempsey

A characteristic internal structure, consisting of a double-layered outer wall enclosing a matrix-filled space through which pass double-layered membranous folds, would appear to comprise as satisfactory a definition of mitochondria for electron microscopy as their intravital affinity for Janus green affords for light microscopy. Relying for identification upon this characteristic internal structure, mitochondria appear to be pleomorphic structures which vary in size, shape, complexity, and density. They are labile also in that their number may increase or decrease under controlled conditions. The possibility therefore exists that these organelles are constantly being formed and destroyed, perhaps by their participation in metabolic processes. The problem of the origin of mitochondria is in an unsatisfactory state. New organelles unquestionably are formed in particular physiological states. The possibility that new bodies are produced by fission of ones already present does not seem adequate. On the other hand, the possible fabrication of new mitochondria out of intracellular membranes, although an attractive hypothesis, has not been adequately substantiated.


2019 ◽  
Vol 14 (2) ◽  
pp. 5-13
Author(s):  
Margarita F. Klimentyeva

The paper focuses on the analyses of the interiorization phenomena in the fantastic (utopian and dystopian) tales by Faddey Bulgarin that he wrote and published between 1825 and 1846. The tales came out in such periodicals as Severnyy archiv, Literturnye zapiski, Syn otechestva. The study of the texts allows to assume that Rus-sian mass literature born within magazine prose was characterized by the interiorization of plots. The latter led to the formation of an adaptive hab-itus entirely assimilated by the Russian cultural and social discourses around the 1830–1840s. The study of the texts by Bulgarin (which in terms of genre can be identified either as journal manifestos or literary works of different genres) indicates his conscious orientation on the reader, the intended involvement of the reader into the literary and would-be-literary life of an artistic word. On the one hand, that could be the echo of the tradition established by the Enlighteners who educated the reader via literary words, thus shaping his or her ethics and esthetics. On the other hand, that could be the reflection of the interiorization phenomenon that is the structural transposition of a text (text structure) into the internal structure of the reader’s mind. We suggest that the interiorization phenomenon and the shaping of the mass literature are interconnected; the adaptive habitus born in the magazine prose in the mid-1820s – the early 1840s determined the energy of mind and the peculiarities of thinking of the mass reader. Despite almost no narrator addressing the reader in the fantastic tales, the reader finds him- or herself indirectly present throughout the texts as an addressee of the interiorization. The discursive strategy adopted by Bulgarin consists of the transformation of the reader’s mind patterns into the adaptive habitus of mass literature.


1969 ◽  
Vol 6 (3) ◽  
pp. 399-425 ◽  
Author(s):  
D. C. Findlay

The Tulameen Complex is a composite ultramafic-gabbroic intrusion that outcrops over 22 sq. mi. (57 km2) in the Southern Cordillera of British Columbia. The complex intruded Upper Triassic metavolcanic and metasedimentary rocks of the Nicola Group, and on the basis of geologic relations and a K–Ar age determination (186 m.y.) is tentatively dated as Late Triassic.The principal ultramafic units — dunite, olivine clinopyroxenite, and hornblende clinopyroxenite — form an elongate, non-stratiform body whose irregular internal structure is best explained by deformation contemporaneous with crystallization of the rocks. The derivation of the ultramafic rocks is attributed to fractional crystallization of an ultrabasic magma. The gabbroic mass, which consists of syenogabbro and syenodiorite, partly borders and partly overlies the ultramafic body and was apparently intruded by it.The ultramafic and gabbroic parts of the complex probably formed from separate intrusions of different magmas, but the two suites have sufficient mineralogical and chemical features in common to indicate an ultimate petrogenic affinity of the magmas. Comparison of the Tulameen rocks with nearby intrusions of the same general age, in particular the Copper Mountain stock, suggests that they are members of a regional suite of alkalic intrusions. The possibility is also raised that these intrusions may be comagmatic with the Nicola volcanic rocks.


2016 ◽  
Vol 60 (4) ◽  
pp. 530-561
Author(s):  
Charlotte R. Vaughn ◽  
Ann R. Bradlow

While indexical information is implicated in many levels of language processing, little is known about the internal structure of the system of indexical dimensions, particularly in bilinguals. A series of three experiments using the speeded classification paradigm investigated the relationship between various indexical and non-linguistic dimensions of speech in processing. Namely, we compared the relationship between a lesser-studied indexical dimension relevant to bilinguals, which language is being spoken (in these experiments, either Mandarin Chinese or English), with: talker identity (Experiment 1), talker gender (Experiment 2), and amplitude of speech (Experiment 3). Results demonstrate that language-being-spoken is integrated in processing with each of the other dimensions tested, and that these processing dependencies seem to be independent of listeners’ bilingual status or experience with the languages tested. Moreover, the data reveal processing interference asymmetries, suggesting a processing hierarchy for indexical, non-linguistic speech features.


2021 ◽  
Vol 12 (1) ◽  
pp. 48
Author(s):  
Moussa Side ◽  
Eby Yoboué Gnamma Honorine Alla ◽  
Behiri Innocent Kakou ◽  
Béatrice Abouo Adepo-Gourene

The growth and size at first sexual maturity of the species Ethmalosa fimbriata were studied in two sites in the Ebrié lagoon: Bietri, a highly anthropized environment and Vitré 2, a reference site. Growth parameters estimated from size frequencies showed that growth in both size and weight was faster in females than in males regardless of habitat. On the other hand, specimens from Biétri bay have a slower growth rate than those from Vitré 2. In Bietri bay, individuals are characterized by early sexual maturity. They reach sexual maturity at the age of 0.55 years (about 7 months), corresponding to a size of 6.13 cm for males and 8.42 cm for females; whereas in Vitré 2, they reach sexual maturity at the age of 0.82 years (about 10 months) corresponding to a size of 10.22 cm and 12.94 cm for males and females respectively. These results show that in a highly antropic environment, the growth of Ethmalosa fimbriata is affected and individuals reproduce earlier.


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