FRAGMENT OR BROKEN? IMPROVING THE PLANKTONIC FORAMINIFERA FRAGMENTATION ASSESSMENT

Palaios ◽  
2021 ◽  
Vol 36 (5) ◽  
pp. 165-172
Author(s):  
JAIME YESID SUÁREZ-IBARRA ◽  
CRISTIANE FRAGA FROZZA ◽  
SANDRO MONTICELLI PETRÓ ◽  
MARIA ALEJANDRA GÓMEZ PIVEL
Keyword(s):  
Weight Loss ◽  
Calcium Carbonate ◽  
Planktonic Foraminifera ◽  
Carbonate Content ◽  
Sand Content ◽  
Future Studies ◽  
Software Analysis ◽  
Fragmentation Index ◽  
Area And Perimeter ◽  
Partial Damage

ABSTRACT Planktonic foraminifera tests can suffer dissolution, which usually involves partial damage, weight loss, and fragmentation. Since planktonic foraminifera assemblages, consisting of different resistant/susceptible species, can be strongly modified by dissolution, it is imperative to quantify its effect. The fragmentation index proposed 50 years ago has been used widely to measure preservation of planktonic foraminifera tests, but calibrations to this method are necessary. Some revisions are based on assumptions, like a certain number of fragments produced by a unique test, which is then used to compare whole tests with the dissolution remains. Likewise, researchers do not agree on what they count and how they identify what they count. Here we present a standardized and less subjective method, called fragmentation intensity (FI), to better assess the fragmentation of planktonic foraminifera through image software analysis, which includes both fragmentation remains (fragments and broken tests) and their measured area and perimeter. When compared to calcium carbonate content, grain sand content, and planktonic foraminifera tests per gram of dry sediment, the FI method derived better correlation values than the broken and fragments indexes. Future studies, in varying oceanographic contexts, can test this method to improve confidence, and eventually possibly adapt the index into a proxy for calcium carbonate undersaturation.

scholarly journals Opto‐electrochemical Dissolution Reveals Coccolith Calcium Carbonate Content

2021 ◽  
Author(s):  
Minjun Yang ◽  
Christopher Batchelor-McAuley ◽  
Samuel Barton ◽  
Rosalind E.M. Rickaby ◽  
Heather A. Bouman ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Carbonate Content ◽  
Electrochemical Dissolution ◽  
Calcium Carbonate Content

scholarly journals A Novel Resorbable Composite Material Containing Poly(ester-co-urethane) and Precipitated Calcium Carbonate Spherulites for Bone Augmentation—Development and Preclinical Pilot Trials

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 102
Author(s):  
Claudia Rode ◽  
Ralf Wyrwa ◽  
Juergen Weisser ◽  
Matthias Schnabelrauch ◽  
Marijan Vučak ◽  
...  
Keyword(s):  
Composite Material ◽  
Calcium Carbonate ◽  
Bone Substitute ◽  
Pilot Trial ◽  
Carbonate Content ◽  
Precipitated Calcium Carbonate ◽  
Degradation Behaviour ◽  
Biodegradable Composite ◽  
Loss Of Mass

Polyurethanes have the potential to impart cell-relevant properties like excellent biocompatibility, high and interconnecting porosity and controlled degradability into biomaterials in a relatively simple way. In this context, a biodegradable composite material made of an isocyanate-terminated co-oligoester prepolymer and precipitated calcium carbonated spherulites (up to 60% w/w) was synthesized and investigated with regard to an application as bone substitute in dental and orthodontic application. After foaming the composite material, a predominantly interconnecting porous structure is obtained, which can be easily machined. The compressive strength of the foamed composites increases with raising calcium carbonate content and decreasing calcium carbonate particle size. When stored in an aqueous medium, there is a decrease in pressure stability of the composite, but this decrease is smaller the higher the proportion of the calcium carbonate component is. In vitro cytocompatibility studies of the foamed composites on MC3T3-E1 pre-osteoblasts revealed an excellent cytocompatibility. The in vitro degradation behaviour of foamed composite is characterised by a continuous loss of mass, which is slower with higher calcium carbonate contents. In a first pre-clinical pilot trial the foamed composite bone substitute material (fcm) was successfully evaluated in a model of vertical augmentation in an established animal model on the calvaria and on the lateral mandible of pigs.

scholarly journals Classification of brown earths based on field and laboratory properties: Problematic issues and proposition of their solution

2019 ◽  
Vol 52 (2) ◽  
pp. 225
Author(s):  
Karolina Woźnica ◽  
Agnieszka Józefowska ◽  
Justyna Sokołowska ◽  
Ryszard Mazurek ◽  
Tomasz Zaleski
Keyword(s):  
Calcium Carbonate ◽  
Main Parameter ◽  
Ph Value ◽  
Soil Classification ◽  
Base Saturation ◽  
Carbonate Content ◽  
Field Guide ◽  
Content Determination

<p class="Default">In this paper, the current problems associated with the classification of brown earths, are presented. According to the Polish Soil Classification (PSC) (1989, 2011), base saturation is the main parameter for identifying eutrophic and dystrophic brown soils. In practice, however, it is not possible to determine the base saturation value in the field. Therefore, the aim of this study was to estimate the base saturation using a regression equation and create a field guide for brown earths, based on the pH value, measured using a Hellige indicator, and the calcium carbonate content. Determination of the pH ranges enabled the classification of brown earth types in the field. These results suggest that pH can be used as a proxy for base saturation especially in the field. A change in the hierarchy of soil (sub)types is proposed for the new Polish Soil Classification.</p>

Radiographic Studies on the Formation of the Hen'S Egg Shell

1951 ◽  
Vol 28 (2) ◽  
pp. 125-140
Author(s):  
J. R. G. BRADFIELD
Keyword(s):  
Calcium Carbonate ◽  
Mineral Matter ◽  
Carbonate Content ◽  
Shell Gland ◽  
X Rays ◽  
Characteristic Structure ◽  
Hen’S Egg ◽  
Shell Deposition ◽  
Egg Shell ◽  
Pointed End

1. Radiographic methods have been used to study the rate of deposition of the hen's egg shell and the changes in volume and orientation undergone by the egg in the shell gland. 2. Shell deposition commences about 5 hr. after the yolk is ovulated and several series of radiographs were obtained tracing the process from these earliest stages through to the fully calcined shell. 3. From radiographs of calcium carbonate-gelatin mixtures it was found that, for a series of comparable objects differing only in calcium carbonate content, the densitometer readings on their radiographs were directly proportional to the density of calcium carbonate traversed by the X-rays in each object. 4. Hence, densitometer measurements on the periphery of the shell in each of a series of radiographs taken during the development of a single egg shell give values which are proportional to the density (or thickness) of calcium carbonate traversed by the tangential rays. It is shown that the radial thickness is closely proportional to the square of these values. 5. Plotting these squared densitometer readings against time indicates that the rate of deposition of mineral matter in the shell follows an S-shaped curve, with a marked acceleration in shell deposition 5-6 hr. after its onset. 6. During its first few hours in the shell gland, the egg undergoes a 25% osmotic increase in volume. This swelling is brought to a fairly abrupt halt by the increase in the rate of shell deposition and the consequent increase in the impermeability and rigidity of the shell. 7. Throughout all but the last hour or two of its 20 hr. stay in the shell gland, the egg lies with its pointed end caudal. Shortly before it is laid, however, it usually undergoes a 180° rotation in a horizontal plane. Thus the blunt end finally becomes caudal and emerges first when the egg is laid. During the rotation, the egg sinks to a more ventral position. This is necessary because, in most hens, the length of the egg plus the thickness of the walls of the shell gland is greater than the width of the pelvis. 8. The possible significance of the S-shaped curve of shell deposition is discussed. The volume, shape and orientation of the egg are considered in relation to the needs of the chick embryo and to the characteristic structure of the bird's oviduct and pelvis.

Studies in the absorption and excretion of certain minerals by poultry. III. The influence of different levels of dietary calcium upon the retention of calcium, phosphorus, carbonate and chloride

1946 ◽  
Vol 36 (4) ◽  
pp. 283-288 ◽  
Author(s):  
Cyril Tyler
Keyword(s):  
Calcium Carbonate ◽  
Dietary Calcium ◽  
Egg Laying ◽  
Carbonate Content ◽  
Phosphorus Excretion ◽  
Calcium Carbonate Content ◽  
High Calcium ◽  
Calcium Phosphorus ◽  
Different Levels

1. The daily retention of calcium, carbonate, phosphorus and chloride was studied using four birds and changing the calcium carbonate content of the ration every 5 days for 15 days.2. It was shown that high calcium diets result in a much lower retention of calcium and thin-shelled eggs are produced.3. Retention of calcium was higher in the laying than in the non-laying bird when calcium carbonate was fed.4. High calcium diets depressed the retention of phosphorus, and in one case the retention was negative, even when no eggs were laid. Laying birds gave negative values for retention because of the heavy phosphorus excretion associated with egg laying.5. High calcium diets also depressed the retention of chloride, and on occasion led to negative retention values.

scholarly journals Exploring the Viability of Exogenous Ketones as Weight Loss Supplements (P21-017-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Angela Poff ◽  
Andrew Koutnik ◽  
Sara Moss ◽  
Sahith Mandala ◽  
Dominic D'Agostino
Keyword(s):  
Weight Loss ◽  
Caloric Restriction ◽  
Ketone Bodies ◽  
Standard Diet ◽  
Medium Chain Triglycerides ◽  
Future Studies ◽  
Medium Chain ◽  
Funding Sources ◽  
Beta Hydroxybutyrate ◽  
Main Strategy

Abstract Objectives 70.7% of Americans over 20 years of age are overweight or obese. Currently, the main strategy for weight loss is caloric restriction. Ketone bodies have been shown to facilitate voluntary caloric restriction through altering the appetite stimulating hormone ghrelin. However, these non-toxic ketone bodies have not been evaluated as weight loss supplements. C57BL6J mice were used to determine the weight loss efficacy of exogenous ketones by adding synthetic (R/S 1,3-Butanediol Acetoacetate Diester and 1,3-Butanediol) and natural (Beta-hydroxybutyrate and Beta-hydroxybutyrate + Medium Chain Triglycerides) ketogenic agents to standard rodent chow ab-libitum. Methods Six groups (R/S 1,3-butanediol acetoacetate diester, 1,3-butanediol, beta-hydroxybutyrate, beta-hydroxybutyrate + medium chain triglycerides, caloric restriction, standard diet ad-libitum) were housed 2–5 animals per cage and monitored to ensure appropriate acclimation prior to intervention. Mice were treated for two weeks with ketogenic agents, adjusting % of agent daily to ensure 20% weight loss was achieved. Results All ketogenic agents induced weight loss and voluntary caloric restriction. Weight loss for beta-hydroxybutyrate and beta-hydroxybutyrate + medium chain triglycerides was explained by caloric restriction alone. However, R/S 1,3-butanediol acetoacetate diester induced weight loss at lower dosages which could not be explained by caloric restriction alone. Conclusions Taken together, all ketogenic agents may assist in weight loss. However, R/S 1,3-butanediol acetoacetate diester appears to be a more potent non-toxic ketogenic supplement that facilitates weight loss via both voluntary caloric restriction and caloric restriction-independent mechanisms. Future studies should explore caloric-restriction independent weight loss mechanisms of R/S 1,3-butanediol acetoacetate diester. Funding Sources Disruptive Nutrition.

Building amorphous calcium carbonate into geochemical biomineralisation models

2020 ◽  
Author(s):  
David Evans ◽  
William Gray ◽  
James Rae ◽  
Rosanna Greenop ◽  
Paul Webb ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Isotope Fractionation ◽  
Planktonic Foraminifera ◽  
Transformation Process ◽  
Geochemical Data ◽  
Amorphous Calcium Carbonate ◽  
Carbonate System ◽  
Precursor Phase ◽  
Shell Geochemistry

&lt;p&gt;Amorphous calcium carbonate (ACC) has been observed, or inferred to exist, in the majority of the major phyla of marine calcifying organisms. The CaCO&lt;sub&gt;3&lt;/sub&gt; produced by these organisms represents one of the largest long-term carbon sinks on Earth&amp;#8217;s surface, such that identifying how calcification will respond to anthropogenic climate change is an urgent priority. A substantial portion of our knowledge of the biomineralisation process of these organisms is derived from inferences based on skeletal geochemical data, yet such models typically do not include an ACC component because little is known about trace element and isotope fractionation into ACC. In order to address this, we present, to our knowledge, the first structural and geochemical data of ACC precipitated from seawater under varying carbonate system conditions, seawater Mg/Ca ratios, and in the presence of three of the most common intracrystalline amino acids (aspartic acid, glutamic acid, and glycine). Based on these data we identify the carbonate system conditions necessary to produce ACC from seawater [Evans &lt;em&gt;et al&lt;/em&gt;., 2019], and identify the dominant controls on ACC geochemistry. As an example, we utilise these data to build a simple biomineralisation model for the low-Mg (e.g. planktonic) foraminifera, based on precipitation of low-Mg calcite through an ACC precursor phase in a semi-enclosed pool. This exercise demonstrates that the observed shell geochemistry of this group of organisms can be fully reconciled with a model that includes an ACC component, and moreover that constraints can be placed on the degree of ACC utilisation and the ACC-calcite transformation process. More broadly, the exercise demonstrates that knowledge of the characteristics and geochemistry of ACC is important in the development of a process-based understanding of marine calcification.&lt;/p&gt;&lt;p&gt;Evans, D., Webb, P., Penkman, K. Kr&amp;#246;ger, R., &amp; Allison, N. [2019] The Characteristics and Biological Relevance of Inorganic Amorphous Calcium Carbonate (ACC) Precipitated from Seawater. &lt;em&gt;Crystal Growth &amp; Design&lt;/em&gt; &lt;strong&gt;19&lt;/strong&gt;: 4300.&lt;/p&gt;

scholarly journals Impact of seawater <i>p</i>CO<sub>2</sub> on calcification and Mg/Ca and Sr/Ca ratios in benthic foraminifera calcite: results from culturing experiments with <i>Ammonia tepida</i>

2010 ◽  
Vol 7 (1) ◽  
pp. 81-93 ◽  
Author(s):  
D. Dissard ◽  
G. Nehrke ◽  
G. J. Reichart ◽  
J. Bijma
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Benthic Foraminifera ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Planktonic Foraminifera ◽  
Ambient Conditions ◽  
Precipitated Calcium Carbonate ◽  
Shell Weight ◽  
Dissolved Carbon

Abstract. Evidence of increasing concentrations of dissolved carbon dioxide, especially in the surface ocean and its associated impacts on calcifying organisms, is accumulating. Among these organisms, benthic and planktonic foraminifera are responsible for a large amount of the globally precipitated calcium carbonate. Hence, their response to an acidifying ocean may have important consequences for future inorganic carbon cycling. To assess the sensitivity of benthic foraminifera to changing carbon dioxide levels and subsequent alteration in seawater carbonate chemistry, we cultured specimens of the shallow water species Ammonia tepida at two concentrations of atmospheric CO2 (230 and 1900 ppmv) and two temperatures (10 °C and 15 °C). Shell weights and elemental compositions were determined. Impact of high and low pCO2 on elemental composition are compared with results of a previous experiment were specimens were grown under ambient conditions (380 ppvm, no shell weight measurements of specimen grown under ambient conditions are, however, available). Results indicate that shell weights decrease with decreasing [CO32−], although calcification was observed even in the presence of calcium carbonate under-saturation, and also decrease with increasing temperature. Thus both warming and ocean acidification may act to decrease shell weights in the future. Changes in [CO32−] or total dissolved inorganic carbon do not affect the Mg distribution coefficient. On the contrary, Sr incorporation is enhanced under increasing [CO32−]. Implications of these results for the paleoceanographic application of foraminifera are discussed.

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