Shell Calcification Research Articles

Characterization of Thyroid Nodule by Sonographic Features

Introduction: The thyroid is an endocrine gland situated in the infrahyoid compartment of neck in a space outlined by muscle, trachea, esophagus, carotid arteries and jugular veins. Though nodular thyroid disease is relatively common, thyroid cancer is rare and accounts for less than 1% of all malignancies indicating that overwhelming majority of thyroid nodules are benign. The purpose of this study was to assess the sonographic characteristics in a solitary thyroid nodule and predict risk of malignancy.Methods: This prospective study was conducted in a tertiary care hospital in Kathmandu.62 patients with palpable thyroid nodule were evaluated for sonographic characteristics .USG guided FNA for cytopathological examination was then performed.Results: Out of 66 patients, four were subsequently excluded because they didn’t fulfill the inclusion criteria. Of the 62 patients, 47 (75.8%) were females and 15 (24.2%) were males. Among 56 benign nodules, 45 (80.4%) were in females and 11(19.6) were in male. Among 6 malignant nodules, 4(66.7%) were in males and 2 (33.3%) were in females. Result shows 5 malignant nodules (83.3%) were solid where as 1 malignant nodule (16.7%) was complex with solid predominance. All 4 cystic nodules (7.1%) were benign. All complex nodules with predomint cystic components were also benign. One malignant nodule (16.7%) had snow storm type of microcalcification. None of the benign nodules had microcalcification. Nodule having microcalcification was malignant. Findings showed that all malignant nodules (100%) had increased internal vascularity whereas benign nodules were variable in internal vascularity.Conclusion: This study has shown that colloid goiter is the commonest benign diagnosis whereas papillary carcinoma is the commonest malignancy. Malignant nodules are solid or predominantly solid whereas cystic and predominantly cystic nodules are likely to be benign. Macrocalcification and internal vascularity are not reliable to differentiate benign from malignant nodule. However, snowstorm calcification makes a nodule likely to be malignant whereas egg shell calcification is characteristic for benign nodule.

Plywood‐like shell microstructures in hyoliths from the middle Cambrian (Drumian) Gowers Formation, Georgina Basin, Australia

AbstractHyoliths are a group of Palaeozoic fossils with calcareous shells whose affinities remain controversial. As their shells were originally aragonitic, their fossils are usually coarsely recrystallized, and few data on their microstructure are available. We report hyoliths from the middle Cambrian (Drumian, Floran) Gowers Formation of the eastern Georgina Basin, Queensland. These are preserved as phosphatic internal moulds, often with the inner layers of the shell also partly replaced by phosphate. Microstructural details preserved by this early diagenetic phosphatization show that these hyolith conchs were originally composed of fibrous crystallites, c. 0.5 μm wide, parallel to one another and to the inner surface of the shell. In several species, the fibres are arranged in a plywood‐like structure composed of multiple lamellae with a different fibre orientation in each lamella: often they are transversely oriented (relative to the long axis of the conch) in the inner part of the wall and longitudinally oriented in the outer part. Opercula also show a microstructure of parallel fibres. The lamello‐fibrillar microstructure we report from hyoliths is reminiscent of microstructures of many Cambrian molluscs; that this microstructure is found in both conchs and opercula suggests that these structures are serial homologues of one another, and in this respect they resemble brachiopod valves. As with many other biological plywoods, the hyolith shell probably records self‐organization in a liquid‐crystal‐like organic matrix. This provided a straightforward way to construct a material that could resist stresses from different directions, offering an effective defence against predators.

Relationship between mineralogy and minor element partitioning in limpets from an Ischia CO2 vent site provides new insights into their biomineralization pathway

It has long since been noted that minor element (Me) partitioning into biogenic carbonates is sometimes different from Me partitioning into inorganically precipitated carbonates. The prime example is the partitioning coefficient, which might be lower or even higher than the one of inorganically precipitated carbonate. Such a difference is usually termed “vital effect” and is seen as indicative of a biologically modified minor element partitioning. Over the last three decades interest in conceptual biomineralization models compatible with minor element and isotope fractionation has been steadily increasing. However, inferring features of a biomineralization mechanism from Me partitioning is complicated, because not all partitioning coefficients show vital effects in every calcium carbonate producing organism. Moreover, the partitioning coefficient is not the only aspect of Me partitioning. Other aspects include polymorph specificity and rate dependence. Patellogastropod limpets are ideally suited for analysing Me partitioning in terms of biomineralization models, because they feature both aragonitic and calcitic shell parts, so that polymorph specificity can be tested. In this study, polymorph-specific partitioning of the minor elements Mg, Li, B, Sr, and U into shells of the patellogastropod limpet Patella caerulea from within and outside a CO2 vent site at Ischia (Italy) was investigated by means of LA-ICP-MS. The partitioning coefficients of U, B, Mg, and Sr (in aragonite) differed from the respective inorganic ones, while the partitioning coefficients of Li and Sr (in calcite) fell within the range of published values for inorganically precipitated carbonates. Polymorph specificity of Me partitioning was explicable in terms of inorganic precipitation in the case of Sr and Mg, but not Li and B. Seawater carbon chemistry did not have the effect on B partitioning that was expected on the basis of data on inorganic precipitates and foraminifera. Carbon chemistry did affect Mg (in aragonite) and Li, but only the effect on Mg was explicable in terms of calcification rate. On the one hand, these results show that Me partitioning in P. caerulea is incompatible with a direct precipitation of shell calcium carbonate from the extrapallial fluid. On the other hand, our results are compatible with precipitation from a microenvironment formed by the mantle. Such a microenvironment was proposed based on data other than Me partitioning. This is the first study which systematically employs a multi-element, multi-aspect approach to test the compatibility of Me partitioning with different conceptual biomineralization models.

Shells from aquaculture: a valuable biomaterial, not a nuisance waste product

AbstractMollusc aquaculture is advocated as a highly sustainable food source and may play an important role in future food security globally. With production increasing worldwide, it is timely to appraise all aspects of aquaculture when considering its expanding role as a food source. In this regard, one regularly overlooked aspect of mollusc aquaculture is waste generation: namely the production of calcareous shells. Shells from the aquaculture industry are widely regarded as a nuisance waste product, yet at the same time, calcium carbonate is mined in the form of limestone and viewed as a valuable commodity. In a time of increased awareness of the need for a circular economy, the aquaculture and seafood industry should consider shells as a valuable biomaterial that can be reused for both environmental and economic benefit. This review discusses the current waste shell issue and identifies large‐scale shell applications that are already in place. Further, it highlights proposed applications that have the potential to be scaled up to address the problem of waste shell accumulations and reduce our reliance on environmentally damaging incineration and landfill disposal. Of the plethora of shell valorisation techniques proposed in the scientific literature, this review will focus only on those that can incorporate large‐scale shell utilisation, and do not require high‐energy processing, and are thus; simple, sustainable and potentially economically viable. Further, this review questions whether, in many cases, shells can provide more inherent value being returned to the marine environment rather than being used in land‐based applications.

Calcite production by the calcifying green alga Phacotus lenticularis

The importance of carbonate precipitation by phytoplankton in fresh water lakes has not been sufficiently considered in global carbon cycles and climate change scenarios. The objective of this study was to determine the influence of the calcifying bivalved phytoflagellate Phacotus lenticularis (Ehrenberg) Deising 1866 on the total calcite precipitation in five European hard-water lakes. For this purpose, an accurate mass determination of single Phacotus lenticularis shells was required. We developed a novel methodological approach to precisely determine the volume and mass of the calcified shells. Focused ion beam (FIB) techniques were employed to investigate internal structural features. Thin layer cross-sections of the shell profiles were reproduced and perforation as well as the crystalline structure of the calcite plates were monitored. 3D-shell models were computed by 360° rotation of the shell cross-sections using a CAD 3D imaging software to calculate precise volumes and estimate realistic masses. In contrast to previous estimates, we determined a 2.8-fold higher shell mass of 0.86 ng CaCO3 (standard deviation SD = 0.18) for the highly massive shells at a mean volume per individual of 334.1 µm³ (SD = 70). An initial shell porosity of less than 5% was derived from thin layer cross-section images, resulting in a presumed mean shell density of 0.0026 ng µm−3. The shell diameter was significantly influenced by the lake’s origin. The shells from each lake displayed substantial variations in diameter and shape. The pores in the shells showed two variations. Wider pore canals penetrated the whole shell wall, whereas small, elongated pores were located along the interspaces between calcite crystals with tabular habit. The approximate average dimensions of these calcite plates were 1.0 × 1.6 × 0.2 µm. The mean lateral wall thickness at the rim and centre of the shell were 1.98 µm (SD = 0.42) and 0.79 µm (SD = 0.17), respectively. The average carbonate precipitation by Phacotus lenticularis in relation to the total epilimnetic suspended calcite precipitation was 6.0% in the oligotrophic lake Großer Ostersee (Bavaria, Germany). During the growing season, Phacotus lenticularis contributed up to 21% of the particulate calcium carbonate in the epilimnion. These findings suggest that Phacotus lenticularis should be considered in the assessment of hard-water lake carbon cycling.

Artificial mineral films similar to biogenic calcareous shells: oriented calcite nanorods on a self-standing polymer sheet

Micrometre-thick calcareous shells consisting of c-axis-oriented calcite nanorods are produced on an organic sheet as mimetics of foraminiferal tests and isopod cornea cuticles.

The ‘last’ tentaculitoids

ABSTRACTAn earliest Famennian (Late Devonian) record of tentaculitoids (an extinct ‘class’ of small calcareous conical shells) preserved as palynomorphs is documented from Sosnogorsk in the Komi Republic of Russia. These were preserved in considerable abundance in a near-shore shallow lagoon subjected to marine flooding with euxinia. Four forms of nowakiid tentaculitoids plus related aberrant forms are documented. They represent evidence for survival of the nowakiids into the earliest Famennian and hence post-date the Frasnian–Famennian mass extinction. It is hypothesised that the Frasnian and younger occurrence of tentaculitoids as palynomorphs may relate to a changing balance of carbonate and organic matter in their shells driven by the environmental conditions of the Frasnian–Famennian mass extinction.

Sonographic evaluation of solitary thyroid nodule with cytopathological correlation

Background: Nodular thyroid disease is a common health problem affecting women affected more frequently than men. Benign conditions like simple thyroid cyst, iodine deficiency disorder, chronic inflammatory disease of thyroid (like Hashimoto?s thyroiditis) as well as malignancy of different grades (ranging from well differentiated papillary carcinoma to high grade follicular neoplasm) can present with thyroid nodules. Differentiation between two entities based on clinical and biochemical ground alone is hardly possible and here comes the role of high resolution ultrasonography. Because of superficial location USG can identify normal thyroid anatomy and pathologic conditions with remarkable clarity. Based on sonologic features it is possible to predict whether a nodule is malignant or not and hence whether follow-up is sufficient or more invasive procedure is imperative. Materials & Methods: Fifty sequential adult patients of 15-60years of age presenting with nodular thyroid disease were studied over the period of one and half years (January 2016 to June 2017). Specific USG criteria were used to characterize the nodules so that a probable diagnosis could be made. Sonological diagnoses then compared with cytological results to conclude role of USG to analyse nodular thyroid disease. Result & Analysis: 50 patients were studied with a mean age of 37.4 years. Benign lesions constitute the majority (total 43 cases) four patients were diagnosed as having papillary carcinoma & three as case of follicular neoplasm. Most of the patients presented with long standing painless palpable thyroid swelling. Majority of malignant thyroid nodules presented as solitary hypoechoic solid nodules with intranodular vascularity. On contrary benign lesions were mainly iso or hyper echoic, multiple or solitary, well margined nodules with perinodular vascularity. Cervical lymphadenopathy & micro calcification were found almost exclusively in papillary carcinoma, whereas peripheral egg shell calcification &comet tail artifacts were seen only in hyperplastic nodules. Conclusion: Nodular thyroid disease was found to be of female predominance with benign causes outnumbered malignancy. USG assessment helped assess characteristics of thyroid nodules to reach a provisional diagnosis. We had taken into account parameters and among them taller than wide shape, intranodular vascularity with or with-out perinodular component and marked hypoechogenicity emerged as most useful.

Impacts of Near-Future Ocean Acidification and Warming on the Shell Mechanical and Geochemical Properties of Gastropods from Intertidal to Subtidal Zones.

Many marine organisms produce calcareous shells as the key structure for defense, but the functionality of shells may be compromised by ocean acidification and warming. Nevertheless, calcifying organisms may adaptively modify their shell properties in response to these impacts. Here, we examined how reduced pH and elevated temperature affect shell mechanical and geochemical properties of common grazing gastropods from intertidal to subtidal zones. Given the greater environmental fluctuations in the intertidal zone, we hypothesized that intertidal gastropods would exhibit more plastic responses in shell properties than subtidal gastropods. Overall, three out of five subtidal gastropods produced softer shells at elevated temperature, while intertidal gastropods maintained their shell hardness at both elevated pCO2 (i.e., reduced pH) and temperature. Regardless of pH and temperature, degree of crystallization was maintained (except one subtidal gastropod) and carbonate polymorph remained unchanged in all tested species. One intertidal gastropod produced less soluble shells (e.g., higher calcite/aragonite) in response to reduced pH. In contrast, subtidal gastropods produced only aragonite which has higher solubility than calcite. Overall, subtidal gastropods are expected to be more susceptible than intertidal gastropods to shell dissolution and physical damage under future seawater conditions. The increased vulnerability to shell dissolution and predation could have serious repercussions for their survival and ecological contributions in the future subtidal environment.

Range expansion of a fouling species indirectly impacts local species interactions.

We investigated how recent changes in the distribution and abundance of a fouling organism affected the strength of interactions between a commercially important foundation species and a common predator. Increases in the abundance of boring sponges that bioerode the calcified shells of oysters and other shelled organisms have been attributed to increased salinization of estuarine ecosystems. We tested the hypothesis that fouling by boring sponges will change the interaction strength between oysters and a common predator (stone crabs). We generated five oyster density treatments crossed with two sponge treatments (sponge and no sponge). We contrasted the interaction strength between stone crabs and fouled and non-fouled oysters by comparing the parameters of fitted functional response curves based on Rogers random predation model. We found that fouled oysters suffered higher predation from stone crabs, and that the increased predation risk stemmed from a reduction in the handling time needed to consume the fouled oysters. These findings highlight the importance of understanding the effects of abiotic changes on both the composition of ecological communities, and on the strengths of direct and indirect interactions among species. Global climate change is altering local ecosystems in complex ways, and the success of restoration, management, and mitigation strategies for important species requires a better appreciation for how these effects cascade through ecosystems.

Assessing the utility of transcriptome data for inferring phylogenetic relationships among coleoid cephalopods

Historically, deep-level relationships within the molluscan class Cephalopoda (squids, cuttlefishes, octopods and their relatives) have remained elusive due in part to the considerable morphological diversity of extant taxa, a limited fossil record for species that lack a calcareous shell and difficulties in sampling open ocean taxa. Many conflicts identified by morphologists in the early 1900s remain unresolved today in spite of advances in morphological, molecular and analytical methods. In this study we assess the utility of transcriptome data for resolving cephalopod phylogeny, with special focus on the orders of Decapodiformes (open-eye squids, bobtail squids, cuttlefishes and relatives). To do so, we took new and previously published transcriptome data and used a unique cephalopod core ortholog set to generate a dataset that was subjected to an array of filtering and analytical methods to assess the impacts of: taxon sampling, ortholog number, compositional and rate heterogeneity and incongruence across loci. Analyses indicated that datasets that maximized taxonomic coverage but included fewer orthologs were less stable than datasets that sacrificed taxon sampling to increase the number of orthologs. Clades recovered irrespective of dataset, filtering or analytical method included Octopodiformes (Vampyroteuthis infernalis + octopods), Decapodiformes (squids, cuttlefishes and their relatives), and orders Oegopsida (open-eyed squids) and Myopsida (e.g., loliginid squids). Ordinal-level relationships within Decapodiformes were the most susceptible to dataset perturbation, further emphasizing the challenges associated with uncovering relationships at deep nodes in the cephalopod tree of life.

Characteristics of global organic matrix in normal and pimpled chicken eggshells

The organic matrix from normal and pimpled calcified chicken eggshells were dissociated into acid-insoluble, water-insoluble, and facultative-soluble (both acid- and water-soluble) components, to understand the influence of shell matrix on eggshell qualities. A linear correlation was shown among these 3 matrix components in normal eggshells but was not observed in pimpled eggshells. In pimpled eggshells, the percentage contents of all 4 groups of matrix (the total matrix, acid-insoluble matrix, water-insoluble matrix, and facultative-soluble matrix) were significantly higher than that in normal eggshells. The amounts of both total matrix and acid-insoluble matrix in individual pimpled calcified shells were high, even though their weight was much lower than a normal eggshell. In both normal and pimpled eggshells, the calcified eggshell weight and shell thickness significantly and positively correlated with the amounts of all 4 groups of matrix in an individual calcified shell. In normal eggshells, the calcified shell thickness and shell breaking strength showed no significant correlations with the percentage contents of all 4 groups of matrix. In normal eggshells, only the shell membrane weight significantly correlated with the constituent ratios of both acid-insoluble matrix and facultative-soluble matrix in the whole matrix. In pimpled eggshells, 3 variables (calcified shell weight, shell thickness, and breaking strength) were significantly correlated with the constituent proportions of both acid-insoluble matrix and facultative-matrix. This study suggests that mechanical properties of normal eggshells may not linearly depend on the organic matrix content in the calcified eggshells and that pimpled eggshells might result by the disequilibrium enrichment of some proteins with negative effects.

Egg Shell and Oyster Shell Powder as Alternatives for Synthetic Phosphate: Effects on the Quality of Cooked Ground Pork Products.

This study aimed to determine the optimal ratio of natural calcium powders (oyster shell and egg shell calcium) as synthetic phosphate replacers in pork products. Ground pork samples were subjected to six treatments, as follows: control (−) (no phosphate added), control (+) (0.3% phosphate blend added), treatment 1 (0.5% oyster shell calcium powder added), treatment 2 (0.3% oyster shell calcium powder and 0.2% egg shell calcium powder added), treatment 3 (0.2% oyster shell calcium powder and 0.3% egg shell calcium powder added), and treatment 4 (0.5% egg shell calcium powder added). The addition of natural calcium powders resulted in an increase in the pH values of meat products, regardless of whether they were used individually or mixed. The highest cooking loss was observed (p<0.05) in the negative control samples, whereas the cooking loss in samples with natural calcium powder added was similar (p>0.05) to that in the positive control samples. CIE L* values decreased as the amount of added egg shell calcium powder increased. CIE a* values were higher (p<0.05) in samples containing natural calcium powder (treatments 1, 2, 3, and 4) than in the positive control. The combination of oyster shell calcium powder and egg shell powder (treatment 2 or 3) was effective for the improvement of textural properties of the pork products. The findings show that the combined use of 0.2% oyster shell calcium and 0.3% egg shell calcium should enable the replacement of synthetic phosphate in the production of cooked pork products with desirable qualities.

Modern planktic foraminifers in the high-latitude ocean

Abstract Planktic foraminifers can be sensitive indicators of the changing environment including both the Arctic Ocean and Southern Ocean. Due to variability in their ecology, biology, test characteristics, and fossil preservation in marine sediments, they serve as valuable archives in paleoceanography and climate geochemistry over the geologic time scale. Foraminifers are sensitive to, and can therefore provide proxy data on ambient water temperature, salinity, carbonate chemistry, and trophic conditions through shifts in assemblage (species) composition and the shell chemistry of individual specimens. Production and dissolution of the calcareous shell, as well as growth and remineralization of the cytoplasm, affect the carbonate counter pump and to a lesser extent the soft-tissue pump, at varying regional and temporal scales. Diversity of planktic foraminifers in polar waters is low in comparison to lower latitudes and is limited to three native species: Neogloboquadrina pachyderma, Turborotalita quinqueloba, and Globigerina bulloides, of which N. pachyderma is best adapted to polar conditions in the surface ocean. Neogloboquadrina pachyderma hibernates in brine channels in the lower layers of the Antarctic sea ice, a strategy that is presently undescribed in the Arctic. In open Antarctic and Arctic surface waters T. quinqueloba and G. bulloides increase in abundance at lower polar to subpolar latitudes and Globigerinita uvula, Turborotalita humilis, Globigerinita glutinata, Globorotalia inflata, and Globorotalia crassaformis complement the assemblages. Over the past two to three decades there has been a marked increase in the abundance of Orcadia riedeli and G. uvula in the subpolar and polar Indian Ocean, as well as in the northern North Atlantic. This paper presents a review of the knowledge of polar and subpolar planktic foraminifers. Particular emphasis is placed on the response of foraminifers to modern warming and ocean acidification at high latitudes and the implications for data interpretation in paleoceanography and paleoclimate research.

First description of egg masses, oviposition and copulation of a neglected apple snail endemic to the Iguazú and Alto Paraná Rivers

ABSTRACTThe Ampullariidae have attracted persistent scientific interest, although this has been mostly concentrated on a few invasive species. Pomacea americanista (Von Ihering, 1919) new combination is a neglected species as there has been no published information about its anatomy and natural history since its description in 1919. Our aim was to describe its egg masses, oviposition and copulation to compare them with those of other Ampullariidae. We made observations on egg masses in the Iguazú River and tributaries and on snails reared in the laboratory. Pomacea americanista exhibited the same reproductive mode as other Pomacea species: aerial egg masses composed of hundreds (mean 186.12) of eggs with calcareous shells (mean 3.1 mm in diameter) that are deposited on emergent substrates, mostly rocks. The egg masses were a characteristic pale pink that distinguishes them from those of other species of Pomacea. Embryonic development took nearly 17 days at 26 °C. Hatchlings had a smooth shell with 1⅛ whorls (mean 2.6 mm in diameter) and began to breathe air and feed within a few hours. Copulation was subaquatic and long lasting (mean 16.13 h) and both sexes were highly promiscuous. The evidence gathered supports the hypothesis that P. americanista belongs to the genus Pomacea.http://zoobank.org/urn:lsid:zoobank.org:pub:6484308C-3128-4013-ACCA-A274176958DE

Effects of phenanthrene on early development of the Pacific oyster Crassostrea gigas (Thunberg, 1789)

Phenanthnere (PHE) is a polycyclic aromatic hydrocarbon continuously discarded in the marine environment and bioavailable to many aquatic species. Although studies about PHE toxicity have been documented for adult oysters, the effects on early developmental stages are poorly characterized in bivalves. In this study, the effects of PHE (0.02 and 2.0μg.L−1) were evaluated on the embryogenesis and larval development of Crassostrea gigas. Toxicity bioassays, growth and deformities assessment, analysis of shell calcium abundance and transcript levels of genes related to xenobiotic biotransformation (CYP2AU2, CYP30C1), immune system (Cg-Tal) and tissue growth and shell formation (Ferritin, Insulin-like, Cg-Try, Calmodulin and Nacrein) were assayed in D-shape larvae after 24h of PHE exposure. At the highest concentration (2.0μg.L−1), PHE decreased the frequency of normal development (19.7±2.9%) and shell size (53.5±2.8mm). Developmental deformities were mostly related to abnormal mantle and shell formation. Lower calcium levels in oyster shells exposed to PHE 2.0μg.L−1 were observed, suggesting effects on shell structure. At this same PHE concentration, CYP30C1, Cg-Tal, Cg-Tyr, Calmodulin were upregulated and CYP2AU2, Ferritin, Nacrein, and Insulin-Like were downregulated compared to control larvae. At the lowest PHE concentration (0.02μg.L−1), it was observed a minor decrease in normal larval development (89,6±6%) and the remaining parameters were not affected. This is the first study to provide evidences that exposure to PHE can affect early oyster development at the molecular and morphological levels, possibly threatening this bivalve species.

Exposure, Effects and Absorption of Lead in American Woodcock (Scolopax minor): A Review.

Due to long term declines of American Woodcock (Scolopax minor) and widespread distribution of environmentally available lead (Pb) throughout their geographic range, it is important to assess if Pb exposure is a potential contributor to these declines. Woodcock are exposed to Pb through various environmental sources and are known to exhibit relatively high bone-Pb concentrations. Absorption of Pb by birds, and woodcock specifically, is not well understood. Some studies show that interactions among calcium, phosphorus, iron, zinc, and vitamin D levels may play an important role in Pb absorption. Therefore, when future Pb studies are performed for woodcock, and other birds, interactions among these elements should be considered. For example, these interactions are relevant in the acquisition and mobilization of calcium in female birds during egg development and shell calcification. These factors should be considered to understand potential mechanisms of Pb exposure, Pb absorption, and subsequent Pb toxicity to birds in general, and woodcock specifically. This review discusses Pb exposure routes, effects of Pb toxicity, and the distribution of Pb in American woodcock and identifies areas for future research in woodcock and other avian species.

Possibilidade do uso de Mexilhão Dourado contaminado com metais tóxicos em dietas para frangos de corte

A avicultura brasileira ocupa posição de destaque no cenário mundial e existe a necessidade de que esta produção ocorra de forma sustentável, sendo assim a nutrição destes animais deve ser realizada de forma que provoque o menor impacto ambiental possível. Frente ao exposto surgem as conchas calcárias do mexilhão dourado que é um molusco invasor que ocupa grande parte dos rios de água doce da América do Sul e é responsável por gerar grandes impactos ambientais. O alto teor de cálcio (Ca) presente no mexilhão dourado faz com que este seja um potencial alimento com capacidade de substituir o calcário calcítico em dietas de frangos de corte, porém o seu hábito alimentar filtrador faz com que este possa conter teores de metais tóxicos como o cádmio (Cd) e o chumbo (Pb) que se contidos no interior do mexilhão podem causar contaminação dos frangos e conseqüentemente também dos produtos alimentícios derivados destes.

Effects of Various Calcium Powders as Replacers for Synthetic Phosphate on the Quality Properties of Ground Pork Meat Products.

The aim of this study was to identify the optimal and superior type of natural calcium for replacing phosphate in cooked ground pork products. To achieve this, 0.5% eggshell calcium (ESC), oyster shell calcium (OSC), marine algae calcium (MAC), or milk calcium (MC) was added to ground pork meat products. The effect of this substitution was studied by comparing the substituted products with products containing 0.3% phosphate blend (control). ESC was considered an ideal phosphate replacer for minimizing the cooking loss, which likely resulted from the increase in the pH of the product. Among the other natural calcium types, OSC treatment did not cause a significant increase in pH, but it lowered the cooking loss. CIE L* values were higher (p<0.05) in products treated with OSC or MC than the control, and lowest (p<0.05) in the products with ESC. However, products with ESC had higher (p<0.05) CIE a* and CIE b* values than the control and products treated with other powders. Compared to the control, products treated with ESC and OSC had similar substitution effects on the textural properties of the products. Therefore, the results of this study suggested that the combined use of ESC and OSC could be a potentially effective method for replacing synthetic phosphate in ground pork products.

Another possible risk for the Mediterranean Sea? Aspergillus sydowii discovered in the Port of Genoa (Ligurian Sea, Italy)

Aspergillus sydowii is a cosmopolitan fungus that has been responsible for the mass destruction of coral in the Caribbean Sea over the last 15years. To our knowledge, this study has found the first case of A. sydowii in the Mediterranean Sea, in marine-bottom sediments, water and calcareous shells of bivalve molluscs sampled during a campaign to characterise the mycobiota in the Port of Genoa (Italy). The area is characterised by adverse environmental conditions (high turbidity, organic pollution and high concentrations of phosphorus and nitrogen compounds). These parameters, in combination with a rising temperature, could contribute to A. sydowii bloom and dispersal. This fungal strain may have been imported into the Port of Genoa in the bilge water of vessels or by torrent input. This work represents the first step in the implementation of a monitoring programme to safeguard calcareous sponges and sea fan corals endemic in the Mediterranean Sea.