scholarly journals Size Distribution, Length-Weight Relationship and Condition Index of Tagelus adansonii Bosc 1801 (Mollusca: Bivalvia, Solecurtidae) in the Joal-Fadiouth Lagoon (Senegal)

2021 ◽  
Vol 12 (1) ◽  
pp. 31
Author(s):  
Jeanne Elisabeth Diouf ◽  
Alioune Faye ◽  
Ephigénie Ndew Dione ◽  
Jean Fall ◽  
Babacar Sané ◽  
...  
Keyword(s):  
Size Distribution ◽  
Atlantic Coast ◽  
Condition Index ◽  
East Atlantic ◽  
Size Frequency Distribution ◽  
Weight Relationship ◽  
The Mean ◽  
Condition Indices ◽  
The Many ◽  
Average Size

Size distribution, length-weight relationship and condition index are some of the many parameters that contribute to the study of the growth, environmental conditions and reproduction of an aquatic species. For Tagelus adansonii, only a few studies were carried out on these parameters. This species is a bivalve of the solecurtidae family only found on the East Atlantic Coast between Mauritania and Angola. The objective of this study was to examine the biometric relationships as well as size and condition index variations, within the perspective of resource management. In this study, the average size obtained (47.78mm) from the monthly sampling in Joal Fadiouth lagoon was smaller compared to sizes obtained in other countries for the same genus and species. The size frequency distribution is unimodal, the most abundant class is 45-50mm. The mean condition index is 18.41±16.47 using the formula by Beninger and Lucas (1984). The values of the condition indices varied throughout the duration of the study. In the period of cold-to-warm transition (June) the maximum values of the condition indices were observed, while in the period of warm-to-cold transition (November to December), the minimum values were registered. The allometry is positive (3.07) in Joal as in most studies on this genus.

scholarly journals Paleolimnology of Lake Yamanaka as reflected on particle-size distribution

1970 ◽  
Vol 14 ◽  
pp. 35-42 ◽  
Author(s):  
Danda Pani Adhikari
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Size Distribution ◽  
Central Japan ◽  
Size Frequency Distribution ◽  
Factors Affecting ◽  
Mean Grain Size ◽  
The Mean ◽  
Main Factors ◽  
Lake Size

A 17.63 m long bore-hole core extracted from the deepest part of Lake Yamanaka, one of the Fuji-five Lakes at the northeasternfoot of Mount Fuji, central Japan, composed of sediment with intercalations of scoria fallout deposits. The sediment of the upper11.4 m was investigated for grain-size distribution by using a laser diffraction particle size analyser. The mean grain-size profileshowed various degrees of fluctuations, both short-and long-terms, and the size-frequency distribution revealed unimodal-trimodalmixing of sediments. Changes in lake size and water depth appear to be the main factors affecting the variability in the grain-sizedistribution and properties. The lake level appears low during 7000–5000 cal BP and 2800–1150 cal BP and relatively high during5000–2800 cal BP and 1150 cal BP– present.DOI: http://dx.doi.org/10.3126/bdg.v14i0.5437Bulletin of the Department of Geology Vol.14 2011, pp.35-42 

Grain Coarsening – Insights from Curvature Modeling Cyril Stanley Smith Lecture

2012 ◽  
Vol 715-716 ◽  
pp. 1-12 ◽  
Author(s):  
Roger D. Doherty
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Kinetic Models ◽  
Size Distributions ◽  
Critical Importance ◽  
Grain Coarsening ◽  
The Many ◽  
Log Normal ◽  
Average Size ◽  
Removal Model

Normal and abnormal grain coarsening, NGC and AGC, are briefly reviewed and discussed in the light of grain curvature and kinetic models - notably those of Mullins. The critical importance of the log-normal grain size distribution determined by Hull and the grain shapes measured by Rhines and Craig are reviewed. It is shown that in NGC, as in particle coarsening, the largest grains or particles in their respective distributions grow at the rates, larger by a factor of the ratio of the largest to average size, required to maintain the size distributions during coarsening. The particle curvature removal model for NGC anchorage, giving = 0.2 r/f, developed here, matches surprisingly well the data reviewed by Manohar et al. Finally the need is indicated for further experimental and modeling studies to test the current ideas and to answer the many remaining questions.

Grain Refinement in Titanium-Erbium Alloys

1974 ◽  
Vol 32 ◽  
pp. 522-523
Author(s):  
B. B. Rath ◽  
J. E. O'Neal ◽  
R. J. Lederich
Keyword(s):  
Electron Microscopy ◽  
Size Distribution ◽  
Grain Refinement ◽  
Grain Growth ◽  
Volume Fraction ◽  
Pure Titanium ◽  
Systematic Investigation ◽  
Second Phase ◽  
Titanium Matrix ◽  
Average Size

Addition of small amounts of erbium has a profound effect on recrystallization and grain growth in titanium. Erbium, because of its negligible solubility in titanium, precipitates in the titanium matrix as a finely dispersed second phase. The presence of this phase, depending on its average size, distribution, and volume fraction in titanium, strongly inhibits the migration of grain boundaries during recrystallization and grain growth, and thus produces ultimate grains of sub-micrometer dimensions. A systematic investigation has been conducted to study the isothermal grain growth in electrolytically pure titanium and titanium-erbium alloys (Er concentration ranging from 0-0.3 at.%) over the temperature range of 450 to 850°C by electron microscopy.

Ratio imaging of intracellular ion concentration

1992 ◽  
Vol 50 (2) ◽  
pp. 1160-1161
Author(s):  
Stephen R. Bolsover
Keyword(s):  
Individual Cell ◽  
Video Camera ◽  
Field Of View ◽  
Ion Concentration ◽  
Fluorescence Signal ◽  
Ion Imaging ◽  
Ratiometric Fluorescence ◽  
Ratio Imaging ◽  
The Mean ◽  
The Many

The field of intracellular ion concentration measurement expanded greatly in the 1980's due primarily to the development by Roger Tsien of ratiometric fluorescence dyes. These dyes have many applications, and in particular they make possible to image ion concentrations: to produce maps of the ion concentration within living cells. Ion imagers comprise a fluorescence microscope, an imaging light detector such as a video camera, and a computer system to process the fluorescence signal and display the map of ion concentration.Ion imaging can be used for two distinct purposes. In the first, the imager looks at a field of cells, measuring the mean ion concentration in each cell of the many in the field of view. One can then, for instance, challenge the cells with an agonist and examine the response of each individual cell. Ion imagers are not necessary for this sort of experiment: one can instead use a system that measures the mean ion concentration in a just one cell at any one time. However, they are very much more convenient.

Batch Precipitation of Lead Iodide

1994 ◽  
Vol 59 (6) ◽  
pp. 1301-1304
Author(s):  
Jaroslav Nývlt ◽  
Stanislav Žáček
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Crystal Size ◽  
Lead Nitrate ◽  
Lead Iodide ◽  
Constant Rate ◽  
Mean Size ◽  
The Mean

Lead iodide was precipitated by a procedure in which an aqueous solution of potassium iodide at a concentration of 0.03, 0.10 or 0.20 mol l-1 was stirred while an aqueous solution of lead nitrate at one-half concentration was added at a constant rate. The mean size of the PbI2 crystals was determined by evaluating the particle size distribution, which was measured sedimentometrically. The dependence of the mean crystal size on the duration of the experiment exhibited a minimum for any of the concentrations applied. The reason for this is discussed.

scholarly journals Coverage Increases of Porites astreoides in Grenada Determined by Shifts in Size-Frequency Distribution

Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 288
Author(s):  
Ryan G. Eagleson ◽  
John S. Lumsden ◽  
Lorenzo Álvarez-Filip ◽  
Christophe M. Herbinger ◽  
Ryan A. Horricks
Keyword(s):  
Coral Community ◽  
Scleractinian Corals ◽  
Area Measurement ◽  
Coralline Algae ◽  
Measurement Tool ◽  
Size Frequency Distribution ◽  
Point Count ◽  
Porites Astreoides ◽  
The Mean ◽  
The Caribbean

Despite coral community collapse, the mustard hill coral (Porites astreoides) is a species currently experiencing success throughout the Caribbean. The inshore reefs of Grenada were selected to study the influence of benthic factors on the abundance, size, and coverage of P. astreoides colonies. Surveys of reef communities along established 30 m transects were conducted at eight sites in 2014 and 2017 using a 0.5 m² quadrat. Coral Point Count was used to annotate the images, estimating the coverage of scleractinian corals, sponges, algae, and benthic substrates. Coverage, size, and abundance of P. astreoides colonies were quantified using the area measurement tool in ImageJ standardized against the quadrats. There were significant differences in benthic community assemblages between islands, selected sites, and between years. From 2014 to 2017 there was a significant decrease in the mean abundance of P. astreoides colonies and significant increases in mean colony size and coverage. The presence of P. astreoides colonies was significantly correlated with: rubble (−), sand (−); pavement (+); macroalgae (−); coralline algae (+); sponges (varying response); gorgonians (−); massive corals (+); and branching corals (−). P. astreoides follows similar recruitment patterns as other scleractinian corals. Observed changes in P. astreoides populations appear to indicate a recovery event following a disturbance, potentially tropical storm Chantal in 2013.

scholarly journals Structural Changes in Israeli Family Farms: Long-Run Trends in the Farm Size Distribution and the Role of Part-Time Farming

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 518
Author(s):  
Ayal Kimhi ◽  
Nitzan Tzur-Ilan
Keyword(s):  
Size Distribution ◽  
Structural Changes ◽  
Farm Size ◽  
Farm Income ◽  
Higher Moments ◽  
Full Time ◽  
Family Farms ◽  
Income Sources ◽  
Part Time ◽  
The Mean

Israeli agriculture has experienced rapid structural changes in recent decades, including the massive exit of farmers, a resulting increase in average farm size, a higher farm specialization and a higher reliance on non-farm income sources. The higher farm heterogeneity makes it necessary to examine changes in the entire farm size distribution rather than the common practice of analyzing changes in the average farm size alone. This article proposes a nonparametric analysis in which the change in the distribution of farm sizes between two periods is decomposed into several components, and the contributions of subgroups of farms to this change are analyzed. Using data on Israeli family farms, we analyze the changes in the farm size distribution in two separate time periods that are characterized by very different economic environments, focusing on the different contributions of full-time farms and part-time farms to the overall distributional changes. We found that between 1971 and 1981, a period characterized by stability and prosperity, the farm size distribution has shifted to the right with relatively minor changes in higher moments of the distribution. On the other hand, between 1981 and 1995, a largely unfavorable period to Israeli farmers, the change in the distribution was much more complex. While the overall change in the size distribution of farms was smaller in magnitude than in the earlier period, higher moments of the distribution were not less important than the increase in the mean and led to higher dispersion of farm sizes. Between 1971 and 1981, the contributions of full- and part-time farms to the change in the size distribution were quite similar. Between 1981 and 1995, however, full-time farms contributed mostly to the growth in the average farm size, while the average farm size among part-time farms actually decreased, and their contribution to the higher dispersion of farm sizes was quantitatively larger. This highlights the need to analyze the changes in the entire farm size distribution rather than focusing on the mean alone, and to allow for differences between types of farms.

Indeks Kondisi Kerang Bambu yang Didaratkan Di TPI Tasik Agung, Rembang, Jawa Tengah

2021 ◽  
Vol 10 (2) ◽  
pp. 200-204
Author(s):  
Aulia Dessy Ramadhani ◽  
Sri Redjeki ◽  
Jusup Suprijanto
Keyword(s):  
Economic Value ◽  
Condition Index ◽  
Total Weight ◽  
Size Selectivity ◽  
Weight Relationship ◽  
Central Java ◽  
Lack Of Information ◽  
Length Width ◽  
Increasing Demand ◽  
Index Value

Kerang bambu merupakan  salah  satu  jenis  Moluska  dari  famili  Solenidae  yang mempunyai nilai ekonomis. Potensi sumberdaya hayati kerang bambu ini menarik untuk diteliti lebih dalam mengingat permintaannya yang semakin meningkat. Upaya pengambilan kerang bambu jika tidak diimbangi dengan selektivitas ukuran dan dilakukan penangkapan secara terus-menerus maka dapat mengakibatkan hilangnya organisme ini. Mengingat masih minimnya informasi mengenai kerang bambu (Solen sp.) sehingga perlu dilakukan penelitian mengenai morfometri, hubungan panjang dan berat serta indeks kondisi kerang bambu. Tujuan dari penelitian ini adalah mengetahui hubungan panjang cangkang dan berat total serta nilai indeks kondisi dari kerang bambu (Solen sp.). Penelitian ini dilakukan dengan mengukur aspek morfometri seperti panjang, lebar dan berat total. Hasil penelitian menunjukkan hubungan antara panjang cangkang dan berat total memiliki nilai b = 3,99 dan R2=0.5742. Nilai indeks kondisi kerang bambu (Solen sp.) dari TPI Tasik Agung, Rembang, Jawa Tengah pada kategori kurus sebesar 1.9% dengan jumlah 1 ekor, kategori sedang sebesar 13,3% dengan jumlah 67 ekor dan kategori gemuk sebesar 86.4% dengan jumlah 433 ekor.Bamboo clams are type of mollusc from the Solenidae family that have economic value. The potential of bamboo clam is interesting to be investigated more deeply considering its increasing demand. Efforts to collect bamboo clams of it’s not balanced with size selectivity and continuous fishing can result in the loss of these organisms. Given the lack of information on bamboo clams (Solen sp.) it is necessary to conduct research on morphometry, length and weight relationship and condition index of bamboo clams. The purpose of this study was to determine condition index value of bamboo clams (Solen sp.). This research was conducted by measuring morphometric aspects such as length, width, and total weight. The result showed that the condition index value of bamboo clams (Solen sp.) in TPI Tasik Agung, R, Central Java in the thin category was 1.9% with 1 individuals, the moderate category was 13.3% with 67 individuals and the fat category was 86.4% with 433 individuals.

A comparative study on the nursery culture of hatchery-reared sub-adult cupped oyster, Crassostrea iredalei (Faustino, 1932), in an earthen pond and a mangrove canal

2018 ◽  
Vol 26 (4) ◽  
pp. 217-222
Author(s):  
Premwadee Chueachat ◽  
Woraporn Tarangkoon ◽  
Suwat Tanyaros
Keyword(s):  
Growth Rate ◽  
Comparative Study ◽  
Condition Index ◽  
Daily Growth ◽  
Nursery Culture ◽  
Absolute Growth Rate ◽  
Significant Difference ◽  
Adult Oyster ◽  
Absolute Growth ◽  
The Mean

Abstract A comparative study on the nursery culture of the spat of the tropical oyster, Crassostrea iredalei, in an earthen pond and a mangrove canal was conducted over two months. The results revealed no differences in the absolute growth rate determined by shell width between the two culture sites (P < 0.05). Sub-adult oysters cultured in the mangrove canal showed a higher absolute growth rate in shell length and a higher daily growth rate than the oysters cultured in the earthen pond (P < 0.05). The mean survival rate of sub-adult oysters cultured in the earthen pond (99.8 ± 0.2%) was significantly higher than for those cultured in the mangrove canal (66.7 ± 31.4%). Decreased density from the loss of sub-adult oyster nursery culture in the mangrove canal led to higher growth performance than in the earthen pond. However, no difference was found for the fraction of oysters larger or smaller than 5 cm for the two culture sites (P < 0.05). A significant difference was noted in the Condition Index (CI) between the two culture sites (P < 0.05). The high primary productivity in mangroves is a major supporter of higher CI in sub-adult oysters cultured in mangrove canals versus in earthen ponds. Water exchange in the earthen pond to maintain calcium and magnesium concentrations resulted in no differences in the shell compressibility of sub-adult oysters compared with those cultured in the mangrove canal.

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