scholarly journals Reproduction and population structure of the sea cucumber Holothuria tubulosa in the Dardanelles Strait, Turkey

2015 ◽  
Vol 17 (1) ◽  
pp. 47 ◽  
Author(s):  
H. DERELİ ◽  
S. TÜRK ÇULHA ◽  
M. ÇULHA ◽  
B. H. ÖZALP ◽  
A. A. TEKİNAY

In this study, Holothuria tubulosa Gmelin 1791 was investigated from April 2013 to March 2014 in the Dardanelles Strait, to outline the morphological characteristics, reproductive patterns and the relationship between population characteristics and environmental parameters. Between 15 and 30 individuals of this species were sampled monthly from three stations. There was a negative allometry between length and weight, being gutted weight the most reliable measurement for this species. Reproductive patterns of the species were identified the first time for Turkish coasts. By macroscopic examination of the gonads, smallest sizes (gutted length) were measured as 8.4 and 8.1 cm for female and male, respectively. Sex ratio was calculated as 1: 1.1 with differences between seasons. The reproduction of sea cucumbers occurred between August and September after Gonadosomatic Index (GSI) values reached their maximum in July. The species was found down to 10 m depth with a population density of 0.21 / m2, which was rather low compared to previously reported values for Mediterranean populations of this species. There was a high positive correlation between population density and GSI of the species. The highest population density was observed where the largest sea grass meadows are found.

2008 ◽  
Vol 25 (3) ◽  
pp. 479-486 ◽  
Author(s):  
Sharlene R. da S. Torreias ◽  
Ulisses G. Neiss ◽  
Neusa Hamada ◽  
Ruth L. Ferreira-Keppler ◽  
Frederico A.A. Lencioni

The last-stage larva of Bromeliagrion rehni Garrison in De Marmels & Garrison, 2005 is described and illustrated and bionomics and habitat information on this species are provided. The study was conducted in the Reserva Florestal Adolpho Ducke, located near Manaus, state of Amazonas, Brazil.Twelve samplings were done between April, 2003 and April, 2005: six in the rainy season and six in the dry season. In each sampling month, 12 bromeliads (Guzmania brasiliensis Ule, 1907, Bromeliaceae) were collected, six of which were terrestrial and six epiphytic, yielding144 samples. A total of 75 specimens of B. rehni were collected. The relationship between larval B. rehni abundance and the measured environmental parameters (volume (ml), pH, season and stratum) was significant (ANCOVA, F = 5.296, d.f. = 130, p < 0.001). Larvae were most abundant in the rainy season (p < 0.01) and water volume was positively related to the abundance of B. rehni. Larvae of B. rehni can be distinguished from those of B. fernandezianum (the only species in the genus with described larvae) by the number of setae in the prementum and by the color of the apical region of the femur. The association of this species with phytotelmata of G. brasiliensis is reported here for the first time.


2012 ◽  
Vol 81 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Parisa Panahi ◽  
Mohammad R. Pourmajidian ◽  
Asghar Fallah ◽  
Mehdi Pourhashemi

For the first time, pollen morphology of 9 (4 spp. and 5 subspp.) taxa representing lobed leaved oaks of Iran in the family of Fagaceae has been examined and illustrated using light microscopy and scanning electron microscopy of acetolysed material. Detailed pollen morphological characteristics are given for <em>Quercus</em> section. The pollen grains are single, isopolar, radially symmetrical, tricolpate, tricolporoidate or tricolporate. Pollens were studied to show all possible characteristics like shape, size, apertures, wall thickness, etc., with special reference to the specific features of each pollen type such as structural, sculptural and suprasculptural patterns. There is considerable variation in pollen morphology between taxa so that, three types of pollen shape, five types of structural pattern, two types of sculptural pattern, five types of suprasculptural pattern and three types of perfora distribution are defined. Furthermore, the relationship between pollen morphology and taxonomy is discussed. Overall, pollen characters are shown to be a useful and informative tool for assessing taxonomic position within <em>Quercus</em> section in Iran.


2017 ◽  
Vol 81 (1) ◽  
pp. 57
Author(s):  
Daniela Silveira Simão ◽  
José Luís Pérez Gil ◽  
Pere Abelló

Morphological and size dimorphism between genders of the benthopelagic shrimp Pasiphaea sivado are reported for the first time in the present work. All five pleopod protopods of females are thinner and more elongated than the male pleopod protopods, which in turn are anteriorly rounded and have robust shapes. The shape variability of the second pleopod protopods was also analysed using geometric morphometrics techniques which clearly differentiated between the thinner, elongated shape of the females and the robust shape of males. An important application of the observations of sexual dimorphism in pleopod shape in adult P. sivado is, from now on, the ability to quickly assess the gender of individuals when fisheries and population biology studies are carried out in the field unaided by a magnifying. A critical size from which the population sex ratio biases changed from female to male dominance was found in all studied western Mediterranean populations of P. sivado. This critical size different and became progressively smaller from populations in the Alboran Sea to populations in the Catalan Sea. Concerning sex ratio, no significant tendency of gender segregation was found across the bathymetric distribution range of the species, suggesting that this species does not perform differential depth distribution by gender.


Zootaxa ◽  
2008 ◽  
Vol 1923 (1) ◽  
pp. 37-54 ◽  
Author(s):  
LUCIMEIRE DE S. RAMOS LACAU ◽  
CLAIRE VILLEMANT ◽  
ODAIR C. BUENO ◽  
JACQUES H.C. DELABIE ◽  
SEBASTIEN LACAU

The morphology of the eggs and larvae of the ant Cyphomyrmex transversus Emery is here described and discussed for the first time. Some morphological characteristics of the symbiotic fungus that covers the eggs, larvae, and pupae are also examined.


2011 ◽  
Vol 10 (3) ◽  
pp. 139-143 ◽  
Author(s):  
Gazi Islam ◽  
Sarah E. S. Zilenovsky

This note examines the relationship between affirmative action (AA) program perceptions and women’s self-ascribed capacity and desire to become leaders. We propose that women who believe that their organization implements a program of preferential selection toward women will experience negative psychological effects leading to lowered self-expectations for leadership, but that this effect will be moderated by their justice perceptions of AA programs. We test this proposition empirically for the first time with a Latin American female sample. Among Brazilian women managers, desire but not self-ascribed capacity to lead was reduced when they believed an AA policy was in place. Both desire’s and capacity’s relationships with belief in an AA policy were moderated by justice perceptions.


2020 ◽  
Vol 13 (2) ◽  
pp. 112-121
Author(s):  
Sudiyar . ◽  
Okto Supratman ◽  
Indra Ambalika Syari

The destructive fishing feared will give a negative impact on the survival of this organism. This study aims to analyze the density of bivalves, distribution patterns, and to analyze the relationship of bivalves with environmental parameters in Tanjung Pura village. This research was conducted in March 2019. The systematic random system method was used for collecting data of bivalves. The collecting Data retrieval divided into five research stasions. The results obtained 6 types of bivalves from 3 families and the total is 115 individuals. The highest bivalve density is 4.56 ind / m², and the lowest bivalves are located at station 2,1.56 ind / m²,  The pattern of bivalve distribution in the Coastal of Tanjung Pura Village is grouping. The results of principal component analysis (PCA) showed that Anadara granosa species was positively correlated with TSS r = 0.890, Dosinia contusa, Anomalocardia squamosa, Mererix meretrix, Placamen isabellina, and Tellinella spengleri were positively correlated with currents r = 0.933.


2019 ◽  
pp. 42-44
Author(s):  
I.V. GUSAROV ◽  
V.A. OSTAPENKO ◽  
T.V. NOVIKOVА

Впервые в мире создана популяция зубров на территории 60 градусов северной широты. В новых климатических условиях разведения и сохранения зубров определены и проанализированы факторы существования вида на севере Европейской части РФ. Выявлены признаки, динамика численности, которые являются составной частью системы, предназначенной для управления биоразнообразием. Интродукция, являясь процессом введения в экосистему нехарактерных для нее видов, может усиливать изменения биоценозов как положительно, так и отрицательно. Насколько быстро и успешно проходит процесс адаптации заселенного вида, и усматривается его влияние на окружающую среду зависит дальнейшее существование зубров и в целом биоразнообразия. В статье обсуждаются вопросы взаимоотношения зубров с другими видами копытных и хозяйственной деятельностью человека, а также дальнейшим использованием зубров в сельскохозяйственном производстве. Пластичность зубров, выявление изменений и их анализ при вселении видов в новые условия обитания необходимы не только для определения развития или деградации биоценозов и в целом экосистемы, но и прогноза социально-экономических последствий интродукции как одного из методов сохранения редких и исчезающих видов фауны.For the first time in the world, a bison population has been created in an area of 60 degrees north latitude. In the new climatic conditions of breeding and preservation of bison, the factors of the species existence in the north of the European part of the Russian Federation are identified and analyzed. The signs, dynamics of abundance, which are an integral part of the system designed to manage biodiversity are identified, since the preservation of biological diversity on the planet is one of the main problems of our time. Introduction, being the process of introducing non-typical species into an ecosystem, can enhance changes in biocenoses, both positively and negatively. The question posing sounds especially when it comes to such a large hoofed animal as the European bison. How quickly and successfully the process of adaptation of the universe takes place and its environmental impact is seen depends on the continued existence of bison and biodiversity in general. The article discusses the relationship of bison with other types of ungulates and human activities, as well as the further use of bison in agricultural production. How these issues will be resolved positively depends on the future of these animals. Thus, the plasticity of bison, the identification of changes and their analysis, with the introduction of species into new habitat conditions is necessary not only to determine the development or degradation of biocenoses and the ecosystem as a whole, but also to predict the socio-economic consequences due to the introduction as one of the methods of preserving rare and endangered species of fauna.


Author(s):  
David Willetts

Universities have a crucial role in the modern world. In England, entrance to universities is by nation-wide competition which means English universities have an exceptional influence on schools--a striking theme of the book. This important book first investigates the university as an institution and then tracks the individual on their journey to and through university. In A University Education, David Willetts presents a compelling case for the ongoing importance of the university, both as one of the great institutions of modern society and as a transformational experience for the individual. The book also makes illuminating comparisons with higher education in other countries, especially the US and Germany. Drawing on his experience as UK Minister for Universities and Science from 2010 to 2014, the author offers a powerful account of the value of higher education and the case for more expansion. He covers controversial issues in which he was involved from access for disadvantaged students to the introduction of L9,000 fees. The final section addresses some of the big questions for the future, such as the the relationship between universities and business, especially in promoting innovation.. He argues that the two great contemporary trends of globalisation and technological innovation will both change the university significantly. This is an authoritative account of English universities setting them for the first time in their new legal and regulatory framework.


2021 ◽  
Vol 80 (3) ◽  
pp. 1329-1337
Author(s):  
Jure Mur ◽  
Daniel L. McCartney ◽  
Daniel I. Chasman ◽  
Peter M. Visscher ◽  
Graciela Muniz-Terrera ◽  
...  

Background: The genetic variant rs9923231 (VKORC1) is associated with differences in the coagulation of blood and consequentially with sensitivity to the drug warfarin. Variation in VKORC1 has been linked in a gene-based test to dementia/Alzheimer’s disease in the parents of participants, with suggestive evidence for an association for rs9923231 (p = 1.8×10–7), which was included in the genome-wide significant KAT8 locus. Objective: Our study aimed to investigate whether the relationship between rs9923231 and dementia persists only for certain dementia sub-types, and if those taking warfarin are at greater risk. Methods: We used logistic regression and data from 238,195 participants from UK Biobank to examine the relationship between VKORC1, risk of dementia, and the interplay with warfarin use. Results: Parental history of dementia, APOE variant, atrial fibrillation, diabetes, hypertension, and hypercholesterolemia all had strong associations with vascular dementia (p < 4.6×10–6). The T-allele in rs9923231 was linked to a lower warfarin dose (βperT - allele = –0.29, p < 2×10–16) and risk of vascular dementia (OR = 1.17, p = 0.010), but not other dementia sub-types. However, the risk of vascular dementia was not affected by warfarin use in carriers of the T-allele. Conclusion: Our study reports for the first time an association between rs9923231 and vascular dementia, but further research is warranted to explore potential mechanisms and specify the relationship between rs9923231 and features of vascular dementia.


2021 ◽  
Vol 22 (9) ◽  
pp. 4691
Author(s):  
Anastasia V. Poznyak ◽  
Evgeny E. Bezsonov ◽  
Ali H. Eid ◽  
Tatyana V. Popkova ◽  
Ludmila V. Nedosugova ◽  
...  

COVID-19 is a highly contagious new infection caused by the single-stranded RNA Sars-CoV-2 virus. For the first time, this infection was recorded in December 2019 in the Chinese province of Wuhan. The virus presumably crossed the interspecies barrier and passed to humans from a bat. Initially, the disease was considered exclusively in the context of damage to the respiratory system, but it quickly became clear that the disease also entails serious consequences from various systems, including the cardiovascular system. Among these consequences are myocarditis, myocardial damage, subsequent heart failure, myocardial infarction, and Takotsubo syndrome. On the other hand, clinical data indicate that the presence of chronic diseases in a patient aggravates the course and outcome of coronavirus infection. In this context, the relationship between COVID-19 and atherosclerosis, a condition preceding cardiovascular disease and other disorders of the heart and blood vessels, is particularly interesting. The renin-angiotensin system is essential for the pathogenesis of both coronavirus disease and atherosclerosis. In particular, it has been shown that ACE2, an angiotensin-converting enzyme 2, plays a key role in Sars-CoV-2 infection due to its receptor activity. It is noteworthy that this enzyme is important for the normal functioning of the cardiovascular system. Disruptions in its production and functioning can lead to various disorders, including atherosclerosis.


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