8 research outputs found
Macroanatomy and 3-dimensional modeling of the tentacular head of Phascolosoma arcuatum (Grey, 1828)
No full textAbstract: The macroanatomy of the tentacular head of Phascolosoma arcuatum belongs to phylum Sipuncula has been studied under light microscopic methods and computer aided graphics analysis. The tentacular head structure has been reconstructed using computer aided graphics analysis using series histological images on computer aided software platform. The P. arcuatum has only five, semitransparent, pigmented, lobed tentacles in tentacular crown with large tentacular coelomic connections. We found that the tentacles are lined by ciliated columnar epithelium with large number of mucosecretory cells, indicating their deposit feeding habit. Fewer number of tentacles, body wall and there burrowing habit supports there integumentary breathing habit. A thick striated collar encircles the tentacles forming the ventral wall of the mouth channel and protects tentacles from mechanical damage when retracted. These structural peculiarities revealed from macroanatomical analysis are strongly suggestive about the important role of the collar region of the tentacular crown of the head of P. arcuatum in relation to its burrowing habit to its concern habitat.
Keywords: Phascolosoma arcuatum, Deposit feeding, Tentacular Introvert, Anatomical modeling.
Title: Macroanatomy and 3-dimensional modeling of the tentacular head of Phascolosoma arcuatum (Grey, 1828)
Author: Biplab Mahata, Amalesh Choudhury, Subrata Kumar De
International Journal of Life Sciences Research
ISSN 2348-313X (Print), ISSN 2348-3148 (online)
Vol. 6, Issue 3, July - September 2018
Page : 294-298
Publisher: Research Publish Journals
Available at: www.researchpublish.com
DOI: https://doi.org/10.5281/zenodo.6523454
Published Date: 20-August-2018
Paper Download Link: https://www.researchpublish.com/upload/book/Macro%20anatomy-6267.pdf
Research Article Details link: https://www.researchpublish.com/papers/macro-anatomy-and-3-dimentional-modeling-of-the-tentacular-head-of-phascolosoma-arcuatum-grey-1828International Journal of Life Sciences Research
ISSN 2348-313X (Print), ISSN 2348-3148 (online)
Vol. 6, Issue 3, July - September 2018
Page : 294-298
Publisher: Research Publish Journals
Available at: www.researchpublish.co
Take‐off of online marketing: casting the next generation strategies
No full textPurposeThe purpose of this research is to study the emerging nature of on‐line marketing and define the next generation strategies for online marketers.Design/methodology/approachIt is a qualitative research to explain a few factors. Surveys were conducted to determine the view points of consumers. Existing literature and current trends are consideredFindingsOn the basis of the study, author has tried to forecast certain major factors and strategic approaches, which will dominate the on‐line marketing world in the near future.Research limitations/implicationsIt is difficult to predict trends. Extreme technological revolution, huge changes in market dynamics, economy of the nations and few other factors may affect the trends suddenly. So the intensity of the result may vary with time.Practical implications:It will add value to the strategic thinking of the organizations. Especially for the start‐ups firms and for the firms, which are following the traditional on‐line marketing strategies, it will give a new outlook.Originality/valueThe paper attempts to showing the critical factors, which are neglected while building the online marketing strategies. Also, author tries to show the original market trends and the necessity of innovative strategies</jats:sec
THE POSITION AND THE PROTECTION OF WOMEN IN OUR SOCIETY
Get PDF   According to Simone De Beauvoir-‘’ One is not born a women, One becomes a woman.’’ Women’s studies, also known as Feminist Studies; is an interdisciplinary academic field which explores politics, society and history from an inter-sectional, multi-cultural women’s perspective. It critiques and explores societal of GENDER, RACE, CLASS, SEXUALITY, and other inequalities. Today, women in our society display a pronounced apathy towards politics and maintain a safe distance from everything political. Over the years, some non-sociologist and some sociologist have devoted time and effort to assess the problems plaguing women and the quality of change in the position of women in our country. By the late twentieth century, women’s studies courses were available at many colleges and universities around the World
Dynamic, In-situ, Nonlinear-Inelastic Response and Post-Cyclic Strength of a Plastic Silt Deposit
Get PDFThis study presents the use of controlled blasting as a source of seismic energy to obtain the coupled, dynamic, linear-elastic to nonlinear-inelastic response of a plastic silt deposit. Characterization of blast-induced ground motions indicate that the shear strain and corresponding residual excess pore pressures (EPPs) are associated with low frequency near- and far-field shear waves that are within the range of earthquake frequencies, whereas the effect of high frequency P-waves are negligible. Three blasting programs were used to develop the initial and pre-strained relationships between shear strain, EPP, and nonlinear shear modulus degradation. The initial threshold shear strain to initiate soil nonlinearity and to trigger generation of residual EPP ranging from 0.002 to 0.003% and 0.008 to 0.012%, respectively, where the latter corresponded to ~30% of Gmax. Following pre-straining and dissipation of EPPs within the silt deposit, the shear strain necessary to trigger residual excess pore pressure increased two-fold. Greater excess pore pressures were observed in-situ compared to that of intact direct simple shear (DSS) test specimens at a given shear strain amplitude. The reduction of in-situ undrained shear strength within the blast-induced EPP field measured using vane shear tests compared favorably with that of DSS test specimens.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Consequences of mountain pine beetle outbreak on forest ecosystem services in western Canada
Get PDFAfter affecting millions of hectares of pine forests in western Canada, the mountain pine beetle (MPB) is spreading out of its native range and into Canadaâ s boreal forest. Impacts of outbreaks can be environmental, economic, and social, and an ecosystem services (ES) viewpoint provides a useful perspective for an integrated approach to assessing these impacts as well as may help to identify how possible management strategies could minimize these impacts. In this regards, a comprehensive overview of the ecosystem functions and socio-economic factors that have been impacted by the current outbreaks in western Canada was carried out to facilitate a more general ES assessment. In addition to timber production, current MPB outbreaks have negative effects on provisioning services (water supply and food production) and aesthetic cultural services, while effects on regulating services (carbon and forest fire) are still in debate. Among the supporting services, nutrient cycling and aquatic habitat showed short and long term negative effects while terrestrial habitat showed a mostly positive response. The overall impact on ES may be more severe if salvage logging is practiced as a post-MPB forest management strategy. The outcomes of this study may help to identify areas of greatest socio-ecological vulnerability to MPB, and identify knowledge gaps and avenues for research to advance the ES framework for MPB outbreak management.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Wind damage over 21 years across different levels of tree removal in natural-origin mixed forests of northwestern British Columbia
Get PDFIn many regions, forestry practices are shifting to partial harvesting approaches that seek to maintain species and structural diversity in managed forests. We monitored windthrow for 21 years following partial cutting treatments with 0%, 30%, and 60% removal in a large, replicated experiment located in mixed-species mature and old-growth forests of fire origin. There was no evidence that wind damage to merchantable trees (≥17.5 cm) varied among the three removal treatments. We found no evidence of a short-term spike in susceptibility to windthrow after partial cutting during the initial years following treatment. Over 21 years, a total basal area of 2.4 m2·ha–1 was damaged, which was 5.9% of the original standing basal area at the start of the experiment. We found clear differences in susceptibility to windthrow among the different tree species. The percentage of original standing trees that were windthrown varied from 0% to 23.7%. Eight of nine species had ≤10% damage over the monitoring period. Foresters should be aware of differences among tree species in risk of wind damage but should not use a general concern about susceptibility to windthrow as a reason to avoid partial cutting systems (that can achieve a diversity of management objectives) in structurally diverse, multispecies forests.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Geothermal energy resources: potential environmental impact and land reclamation
Get PDFWith increasing costs, finite sources, and adverse environmental impacts of fossil fuels, global attention has focused on developing renewable and clean sources of energy. Although geothermal energy is considered one of the most promising sources of renewable and clean energy, it may not be as benign as widely believed. In this paper, we evaluate the environmental challenges for geothermal resource extraction and describe potential reclamation strategies for disturbed ecosystems. Generally, the environmental impacts of geothermal power generation and direct use are minor and in most cases controllable. Geothermal plants have low emissions of carbon dioxide, hydrogen sulfide, and ammonia, and low land and water usage; these impacts can be minimized through appropriate mitigation measures. Other potential emissions such as mercury, boron, and arsenic may result in local and regional environmental consequences, although their impacts are poorly understood on a global scale. Geothermal plants can alter vegetation and wildlife habitat by reducing species diversity and community composition. There are small risks of subsidence, induced seismicity, and landslides, with potential serious consequences. Integration of timely reclamation during and after plant operation can significantly contribute to reducing long term reclamation costs while enhancing ecosystem recovery. This paper is expected to contribute to understanding environmental impacts associated with geothermal energy production and to determining appropriate mitigation and land reclamation strategies.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Plant community development following reclamation of oil sands mine sites in the boreal forest: a review
Get PDFUnderstanding how reclamation practices influence plant community assembly and succession is an important step in developing realistic indicators and targets for reclamation of oil sands mine sites to upland forest ecosystems. We currently have a poor understanding of factors affecting plant community assembly and succession in reclaimed oil sands sites. Through synthesis of research completed over the last 24 years, we identify four key findings: 1) use of surface soil and forest floor material salvaged from mined areas increases plant species cover, richness and diversity relative to the use of various other cover soil materials (such as clay subsoil); 2) stockpiling of salvaged surface soils decreases the abundance of native plant propagules and delays early vegetation community development; 3) differences in plant community composition between reclaimed and adjacent mature forests remain two decades after placing cover soils; However, differences are smaller with use of forest floor - mineral mix than peat - mineral mix; and 4) plant community assembly is in progress but communities remain different to those found in natural undisturbed conditions. Our review identified critical knowledge gaps for further research to improve understanding of: 1) long term (60 to 100 years) plant community composition in reclaimed oil sands sites; 2) how residual forest patches near disturbed oil sands sites act as seed and propagule sources in newly reclaimed sites; 3) plant community assembly processes in reclamation sites; 4) the effect of micro-topographic heterogeneity on plant community development; and 5) how soil nutrient availability in different substrates influences plant community development over the long term. Ongoing support for selected existing studies and establishment of new studies focussing on plant community development through long term monitoring are highly recommended.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
