The Cuban industry La Purísima produces sauces and dressings for the national gastronomy; but it does not have a process for the deposition of chicken eggshells, as a result, 220 kg of eggshells are dumped daily, which generate a negative impact on the environment. The research evaluates the drying of hen eggshells with protein membrane on a laboratory scale, with a view to revalorizing this waste in the production of a calcium-rich poultry feed supplement. The calcium carbonate content of the shell was determined to confirm the potential application of the residue. The drying curve and drying rate curve was obtained by experimental measurement in a drying oven under aeration at 90 °C. The calcium carbonate content of the residue was 93,33 %. The drying curve was fitted to an exponential mathematical model as a function of the drying constant and the moisture in equilibrium at a temperature of 90 °C. The drying regime of the solid presented a period of decreasing drying rate up to a moisture value of 0,021 kg of water / kg of dry solid, for lower values, this presented a deviation from the exponential function in its rate. The utilization of residual eggshells proved to be an attractive source of calcium carbonate with potential for its use in the production of feed supplement for poultry.

RESUMEN En la Industria cubana La Purísima se producen salsas y aderezos para la gastronomía nacional; pero no dispone de un proceso para la deposición de las cáscaras de huevo de gallina, como resultado, se vierten diariamente 220 kg de cáscaras que generan un impacto negativo en el medio ambiente. La investigación evalúa el secado de las cáscaras de huevo de gallina con membrana proteica a escala de laboratorio, con vistas a revalorizar este residuo en la producción de un suplemento alimenticio para aves de corral rico en calcio. Se determinó el contenido de carbonato de calcio en la cáscara para confirmar la aplicación potencial del residuo. La curva de secado y del régimen de secado se obtuvo por medición experimental en un secadero bajo aireación a 90 °C. El contenido de carbonato de calcio en el residual fue de 93,33 %. La curva de secado se ajustó a un modelo matemático exponencial en función de la constante de secado y la humedad en equilibrio a una temperatura de 90 °C. El régimen de secado del sólido presentó un período de velocidad de secado decreciente hasta un valor de humedad de 0,021 kg de agua / kg de sólido seco, para valores inferiores presentó una desviación de la función exponencial en su velocidad. El aprovechamiento de las cáscaras de huevo residuales resultó ser una fuente atractiva de carbonato de calcio con potencialidades para su utilización en la elaboración de suplemento alimenticio para aves de corral.

RESUMEN El trabajo tuvo el propósito de caracterizar, desde el punto de vista químico, físico, granulométrico y mineralógico, un residuo industrial de hidróxido de calcio generado en el proceso de fabricación de acetileno. Las muestras se analizaron, primeramente, sin neutralizar; luego se realizó el mismo procedimiento, usando ácido sulfúrico a un 98 % de pureza. Para ambos casos, las temperaturas de calentamiento fueron de 500 oC y 900 oC. Para identificar las fases, los patrones de difracción fueron obtenidos usando fuente de radiación de cobre (CuKα, λ=1,5418 Å). Se determinó que el residual presenta CaO y MgO, lo que garantiza su pureza. Al calentarlo sin neutralizar a 500 oC se transforma el hidróxido de calcio y a los 900 oC hay pérdida del carbonato y del agua. En el residual, tanto sin tratamiento como neutralizado, está presente el hidróxido de calcio.

ABSTRACT The purpose of the work was to characterize, from the chemical, physical, granulometric and mineralogical point of view, an industrial residue of calcium hydroxide generated in the acetylene manufacturing process. Samples were first analyzed without neutralization; then the same procedure was performed using 98 % purity sulphuric acid. For both cases, the heating temperatures used were 500 °C and 900 °C. To identify the phases, diffraction patterns were obtained using copper radiation source (CuKα, λ = 1.5418 Å). It was determined that residual contains CaO and MgO, which guarantees its purity; heated at 500 °C, and without neutralizing, calcium hydroxide is transformed and there is loss of water and carbonate at 900 °C. In both untreated and neutralized waste, calcium hydroxide is present.

RESUMEN Esta investigación propone sustituir el cieno carbonatado que se utiliza como agente neutralizante en la tecnología de lixiviación ácida por los polvos residuales de la industria del mármol. El proceso de neutralización del licor en la lixiviación ácida a presión presenta concentraciones de ácido sulfúrico en exceso con valores de pH igual a 1,9 unidades, lo cual permite utilizar los residuos sólidos de carbonato de calcio de la industria del mármol. La investigación se realizó a escala de laboratorio con un régimen de agitación de 68 rpm. Se utilizó el diseño factorial multinivel, donde se estudian dos factores: la masa de sólido del agente neutralizante (1, 2, 3 y 4 g) y la temperatura (50 C y 700 C). Se evaluó, además, el comportamiento de las variables mediante el modelo cinético. Los modelos estadísticos evidenciaron una relación directa entre el aumento de la masa de sólido y la temperatura, donde el primer factor ejerce una influencia positiva en el proceso. Los mejores resultados de pH se obtienen en la prueba 1, para (50 ºC y 1 g), donde se logran valores desde 2,37 hasta 2,53, en el tiempo desde uno hasta 10 minutos.

ABSTRACT This research is a proposal for replacing carbonated silt used as neutralizing agent in acid leaching technology with residual dust from marble industry. The liquor neutralization process in pressure acid leaching contains sulfuric acid concentration to excess with pH values equal to 1.9 units, which allows using solid calcium carbonate residues from marble industry. The research was carried out at laboratory scale with an agitation regime of 68 rpm. The multilevel factorial design was used, where two factors are studied: solid mass of neutralizing agent (1, 2, 3 and 4 g) and temperature (50 ºC and 700 ºC. Behavior of variables was also assessed by means of kinetic model. The statistical models showed a direct relationship between the increase of solid in the mass and the temperature, where the first factor exerts a positive influence on the process. The best pH results are obtained in test 1, for (50 ºC and 1 g), where values from 2,37 to 2,53 are achieved between one to ten minutes.

Resumo A estomatite química é um tipo de lesão traumática causada pelo contato de substâncias químicas e medicamentos com os tecidos bucais, resultando em danos clinicamente significativos. Nesse contexto, é relatado o caso de um paciente do sexo masculino com 14 anos, portador de doença renal crónica, em terapia renal substitutiva (diálise peritoneal) e uso de carbonato de cálcio via cápsulas orais para tratamento. Devido a complicações da diálise peritoneal, o paciente apresentou um quadro de peritonite bacteriana, necessitando de internamento em unidade de terapia intensiva e alteração do modo de terapia dialítica para hemodiálise. Durante o período de internamento, foi observado o desenvolvimento de lesões orais significativas devido à administração inadequada de carbonato de cálcio, interferindo na evolução do estado geral de saúde do paciente e exigindo a assistência de uma equipa odontológica para diagnóstico e tratamento. O paciente foi diagnosticado com estomatite química. Durante o exame clínico foi possível observar a presença de lesões ulceradas e hemorrágicas localizadas no lábio, mucosas jugais, palato duro e palato mole. A fotobiomodulação a laser foi utilizada como tratamento associada ao corticosteróide. Cada região recebeu dez pontos de 1 J, de forma que foram fornecidos 60 J de energia por dia/sessão. No total, foram fornecidos 480 J de energia com um tempo total de irradiação de 4800 s. O paciente relatou melhora considerável dos sintomas álgicos após a primeira sessão de fotobiomodulação a laser. Após 8 sessões, o paciente melhorou e a fotobiomodulação a laser mostrou-se eficaz no tratamento de lesões orais

Abstract Chemical stomatitis is a type of traumatic injury caused by contact of chemical substances and drugs with oral tissues, resulting in clinically significant damage. This case reports a 14-year-old male patient with chronic kidney disease on renal replacement therapy (peritoneal dialysis) and using calcium carbonate via oral capsules for treatment. Due to peritoneal dialysis complications, the patient developed bacterial peritonitis, requiring intensive care unit admission and alteration of his dialysis therapy mode to hemodialysis. During the hospitalization period, significant oral lesions developed due to inadequate calcium carbonate administration, interfering with the evolution of the patient’s general health and requiring the assistance of a dental team for diagnosis and treatment. The patient was diagnosed with chemical stomatitis. During the clinical examination, ulcerated, bleeding lesions were observed on the lip, jugal mucous membranes, hard palate, and soft palate. Laser photobiomodulation was used as a treatment associated with a topical corticosteroid. Each region received ten 1 J/point, and 60 J of energy were delivered per day/session. In total, 480 J of energy were delivered with a total irradiation time of 4800 s. The patient reported considerable improvement in pain symptoms after the first laser-photobiomodulation session. After 8 sessions, the patient had improved, and laser photobiomodulation proved effective for treating oral lesions.

Resumo A crescente investigação da contaminação ambiental por cistos de Giardia spp. e seu impacto na saúde pública despertou o interesse em desenvolver métodos mais sensíveis para detectar esses protozoários, especialmente na água. No entanto, esses métodos ainda são complexos e dispendiosos. Este estudo teve como objetivo avaliar a eficiência de concentração e remoção de cistos de Giardia duodenalis usando um polímero floculante aniônico à base de acrilamida (AFP) em amostras de água de retrolavagem de filtro de uma estação de tratamento de água (ETA) localizada na cidade de Blumenau, sul do Brasil, e compará-lo com a técnica de floculação de carbonato de cálcio (CCF), rotineiramente usada em matrizes de água com alta turbidez. A taxa de recuperação média de cistos de G. duodenalis usando CCF e AFP foi de 33,33% e 43,33%, com uma redução média de turbidez de 98,39% e 98,78%, respectivamente. O uso de um polímero floculante aniônico provou ser uma alternativa eficiente para a concentração e remoção de cistos de protozoários em amostras de água com alta turbidez. É importante destacar que o desenvolvimento e a aplicação de novos estudos e estratégias que aumentem a eficiência da remoção desses organismos de matrizes ambientais complexas trariam benefícios tanto do ponto de vista da saúde pública quanto da perspectiva da saúde única. spp entanto dispendiosos (AFP ETA (ETA Blumenau Brasil comparálo compará lo CCF, , (CCF) G 3333 33 33,33 4333 43 43,33% 9839 98 39 98,39 9878 78 98,78% respectivamente única (CCF 333 3 33,3 433 4 43,33 983 9 98,3 987 7 98,78 33, 43,3 98, 98,7 43,

Abstract The increasing investigation into environmental contamination by Giardia spp. cysts and its impact on public health has spurred interest in developing more sensitive methods for detecting these protozoa, particularly in water. However, these methods remain complex and costly. This study evaluated the concentration and removal efficiency of Giardia duodenalis cysts using an acrylamide-based anionic flocculant polymer (AFP) in filter backwash water samples from a water treatment plant (WTP) located in Blumenau City, southern Brazil, and compared them with the calcium carbonate flocculation technique (CCF), which is routinely used for water matrices with high turbidity. The average recovery rates of G. duodenalis cysts using CCF and AFP were 33.33% and 43.33%, respectively, with an average turbidity reduction of 98.39% and 98.78%. The use of an anionic flocculant polymer proved to be an efficient alternative for the concentration and removal of protozoan cysts in water samples with high turbidity. It is important to highlight that the development and application of new studies and strategies aimed at increasing the efficiency of the removal of these organisms from complex environmental matrices would bring benefits to public health and promote a One Health perspective. spp protozoa However costly acrylamidebased acrylamide based (AFP WTP (WTP City Brazil CCF, , (CCF) G 3333 33 33.33 4333 43 43.33% respectively 9839 98 39 98.39 9878 78 98.78% perspective (CCF 333 3 33.3 433 4 43.33 983 9 98.3 987 7 98.78 33. 43.3 98. 98.7 43.

Abstract. Reef-forming cnidarians are essential for maintaining ecological balance. Unfortunately, coral reefs are endangered due to coral bleaching, which interrupts mutualistic symbiosis between Symbiodiniaceae algae and their coral hosts. Bleaching events result in very high coral mortality and the rapid deterioration of reef structures. Studies aimed at explaining the causes, mechanisms, and consequences of coral bleaching have been mainly conducted with anthozoans, while the impacts of thermal stress responsible for coral bleaching have been scarcely studied in hydrozoans, such as Millepora species (phylum Cnidaria, class Hydrozoa), which are the second most important reef-forming cnidarians. In the present study, the effects of thermal stress caused by the 2015-2016 El Niño on symbiont abundance, exoskeleton structure, and the biochemical composition of Millepora alcicornis were analyzed. Unbleached M. alcicornis specimens exhibited a higher abundance of Breviolum and Durisdinium species, which suggests that unbleached hydrocoral colonies might counteract thermal stress by hosting thermotolerant symbionts of the Durisdinium genus. Bleached hydrocorals exhibited lower levels of calcification than unbleached hydrocorals as well as changes in the microstructure of trabeculae and zooid pores. In contrast, thermal stress did not affect total calcium carbonate and carbohydrate content. Bleached tissues showed significantly higher levels of protein and refractory material, whereas their lipid content decreased considerably. The present study provides evidence that bleached M. alcicornis colonies suffered a decline in calcification and changes in the structure of their exoskeletons after being exposed to the 2015-2016 El Niño. The significant decrease in lipid content suggests that M. alcicornis primarily uses energy stores to maintain vital cellular processes at the expense of calcification.

Resumen. Los cnidarios formadores de arrecifes son esenciales en la ecología marina. Desafortunadamente, están amenazados por el fenómeno de blanqueamiento, el cual rompe la simbiosis mutualista entre algas de la familia Symbiodiniaceae y sus hospederos coralinos. El blanqueamiento causa un alto índice de mortalidad de corales y un rápido deterioro de las estructuras arrecifales. Los estudios dirigidos a explicar causas, mecanismos y consecuencias del blanqueamiento se han realizado principalmente con antozoos, mientras que los impactos del blanqueamiento de corales se han estudiado escasamente en especies de Millepora (phylum Cnidaria, clase Hydrozoa), que son los segundos constructores de arrecifes más importantes. En el presente estudio se analizó el efecto del estrés térmico causado por el evento El Niño 2015-2016 sobre la abundancia de simbiontes, la estructura del exoesqueleto y la composición bioquímica de Millepora alcicornis. Los especímenes sin blanquear de M. alcicornis contenían una mayor abundancia de especies de Breviolum y Durisdinium, lo que sugiere que las colonias de hidrocorales sin blanquear podrían estar contrarrestando el estrés térmico al albergar simbiontes termotolerantes del género Durisdinium. Los hidrocorales blanqueados mostraron niveles más bajos de calcificación y cambios en la microestructura de zooides y trabéculas. En contraste, el estrés térmico no modificó el contenido total de carbonato de calcio y carbohidratos en los hidrocorales. Los tejidos blanqueados mostraron niveles significativamente más altos de proteína y material refractario, mientras que su contenido de lípidos disminuyó considerablemente. El presente estudio muestra que las colonias blanqueadas de M. alcicornis sufrieron una disminución en la calcificación y cambios en la estructura de su exoesqueleto después de estar expuestas al estrés térmico provocado por el evento El Niño 2015-2016. La disminución significativa en el contenido de lípidos sugiere que M. alcicornis está utilizando sus reservas de energía principalmente para mantener sus procesos celulares vitales a expensas de la calcificación.

Resumen El carbonato de calcio está presente en muchas estructuras biológicas, como la concha de bivalvo, que se compone principalmente de dos polimorfos de CaCO3: calcita y aragonito. Sin embargo, existen otras formas de carbonato de calcio como vaterita y carbonato de calcio amorfo (ACC) que no se reportan comúnmente. La selección de polimorfos está influenciada por la concentración de sal, los iones cofactores y la presencia de proteínas de la matriz de la cubierta (SMP) que regulan la deposición de carbonato de calcio, entre otros factores. En este estudio, se evaluó la cristalización in vitro de carbonato de calcio de cuatro soluciones salinas diferentes (1: 40 mM CaCl2, MgCl2, 100 mM NaHCO3; 2: CaCl2, 100 mM Na2CO3; 3: 40 mM CaCl2, MgSO4, 100 mM Na2CO3; 4: CaCl2/MgCl2, 100 mM NaHCO3) en dos molaridades (40 o 100 mM)con diferentes concentraciones la proteína Ps19 (0.2, 0.7 y 1.2 µg/µL) una proteína insoluble extraída de la concha de Pteria sterna, descrita anteriormente como promotora de la cristalización de plaquetas de aragonita. Las cristalizaciones in vitro mostraron que Ps19 es capaz de inducir la deposición de aragonita y calcita de forma dependiente de la dosis, pero también de vaterita en determinadas condiciones, actuando como promotor e inhibidor de la cristalización. Los resultados contribuyen a comprender cómo Ps19 controla la precipitación de polimorfos de calcio en el crecimiento de la capa prismática y de nácar de la concha de P. sterna.

Abstract Calcium carbonate is present in many biological structures such as bivalve shells, which is composed mainly of two CaCO3 polymorphs: calcite and aragonite. However, other forms of calcium carbonate exist like vaterite and amorphous calcium carbonate (ACC) that are not commonly reported. Polymorph selection is influenced by salt concentration, cofactor ions, and the presence of shell matrix proteins (SMPs) which regulates calcium carbonate deposition, among other factors. In this study, in vitro calcium carbonate crystallization of four different saline solutions (1: 40 mM CaCl2, MgCl2, 100 mM NaHCO3; 2: CaCl2, 100 mM Na2CO3; 3: 40 mM CaCl2, MgSO4, 100 mM Na2CO3; 4: CaCl2/MgCl2, 100 mM NaHCO3) at two molarities (40 o 100 mM) was evaluated with increased concentrations of the Ps19 protein (0.2, 0.7 y 1.2 µg/µL), an insoluble extracted protein from the Pteria sterna shell, previously described as a promotor of aragonite platelet crystallization. In vitro crystallizations showed that Ps19 is capable to induce aragonite and calcite deposition in a dose-dependent manner, but also vaterite under certain conditions, acting as a promoter and inhibitor of crystallization. The results contribute to understand how Ps19 control precipitation of calcium polymorphs in the growth of the prismatic and nacre layer of the shell of P. sterna.

ABSTRACT Background. Corals play a fundamental role in reef structure and function because of their ability to deposit calcium carbonate and contribute to the formation of complex three-dimensional structures. However, the functioning potential of a reef community, in terms of its building capacity, is affected by the relative abundance of coral species on the reef. Objectives. Evaluate the physical functionality of coral reefs at six sites in the Parque Nacional Zona Marina del Archipiélago Espíritu Santo (PNZMAES). Methods. The Reef Functional Index (RFI) was implemented as a metric of physical functionality; this tool considers the calcification rate, structural complexity, and abundance of coral species at each site. Results. Las Navajas and San Gabriel sites had the highest coral cover, with 74.72 % and 60.14 %, respectively, while La Ballena was the site with the lowest coral cover (6.77 %). In terms of IFA, the sites with the highest index were Las Navajas (0.68) and San Gabriel (0.65), dominated by Pocillopora meandrina and Pocillopora verrucosa corals, respectively. The site with the lowest IFA was La Ballena (0.35), with Pocillopora verrucosa being the predominant coral. Coral species of the genus Pocillopora were predominant in all sites and contributed the most to the Reef Function Index. Conclusions. The Reef Function Index helped to complement the information on the coral assemblage in the PNZMAES and to understand the performance of coral species in the reef functioning of the Mexican Pacific.

RESUMEN Antecedentes. Los corales desempeñan un papel fundamental en la estructura y función del arrecife debido a su capacidad para depositar carbonato de calcio y contribuir con la formación de estructuras tridimensionales complejas. Sin embargo, el potencial de funcionamiento de una comunidad arrecifal, en términos de su capacidad de construcción, es afectado por la abundancia relativa de las especies de coral que se encuentran en el arrecife. Objetivos. Evaluar la funcionalidad física de los arrecifes de coral en seis sitios del Parque Nacional Zona Marina del Archipiélago Espíritu Santo (PNZMAES). Métodos. Se implementó el Índice Funcional Arrecifal (IFA) como métrica de funcionalidad física; esta herramienta considera la tasa de calcificación, la complejidad estructural y la abundancia de las especies de coral en cada sitio. Resultados. Los sitios Las Navajas y San Gabriel presentaron la cobertura de coral mayor con 74.72 % y 60.14 %, respectivamente, mientras que La Ballena fue el sitio con menor cobertura coralina (6.77 %). En cuanto al IFA, los sitios que presentaron el mayor valor fueron Las Navajas (0.68) y San Gabriel (0.65), dominados por los corales Pocillopora meandrina y Pocillopora verrucosa, respectivamente. El sitio con menor IFA fue La Ballena (0.35), donde Pocillopora verrucosa predominó. Las especies de coral del género Pocillopora son los que predominaron en todos los sitios y los que tuvieron una mayor contribución al IFA. Conclusiones. El IFA ayudó a complementar la información del ensamblaje de corales en el PNZMAES y a entender el desempeño que tienen las especies de coral en el funcionamiento arrecifal del Pacífico mexicano.

ABSTRACT Background. Sclerobionts (e.g., calcareous algae, bryozoans, polychaetes, mollusks, and barnacles) produce reef calcium carbonate (CaCO3). Their contribution is key to maintaining positive CaCO3 balances, especially in marginal reefs. Objective. To compare the production of CaCO3 by sclerobionts in two marginal reefs of the Mexican Pacific: Las Gatas (LG), in Zihuatanejo Guerrero Bay, and La Llave (LL), in Bahía de Los Angeles (Gulf of California). Methods. CAUs (Calcification/Accretion Units) were used to promote sclerobiont recruitment during two deployment times: 6 and 15 months. Results. The calcification rate was high at six months and then decreased due to rapid colonization and initial growth, followed by a decrease over time. Sclerobionts deposited 1.2 ± 0.4 kg CaCO3 m-2 yr-1 in LG, which represents 7% of the production of branching corals in the Mexican South Pacific (17.2 kg m-2 yr-1), while in LL, they deposited 2.1 ± 0.7 kg CaCO3 m-2 yr-1; equivalent to 20% of the production of massive corals in the area (10.1 kg m-2 yr-1). The groups that deposited most CaCO3 were mollusks and bryozoans in LG (up to 0.65 ± 0.16 kg m-2 yr-1) and barnacles in LL (up to 2.32 ± 0.35 kg m-2 yr-1). Conclusions. These results highlight the role of heterotrophs as secondary calcifiers both in LG, a site impacted by anthropogenic activity, and in LL, an area with low anthropogenic impact but high biological productivity associated with upwellings. This finding implies that the environmental conditions at the study sites limit the calcification of primary calcifiers (i.e., corals and CCA) but promote that of secondary calcifiers, with potential geomorphic repercussions.

RESUMEN Antecedentes. Los esclerobiontes (e.g., algas calcáreas, briozoos, poliquetos, moluscos, y balanos) participan en la producción de carbonato de calcio (CaCO3) arrecifal. Su contribución es vital para mantener balances de CaCO3 positivos, especialmente en arrecifes marginales. Objetivo. Comparar la producción de CaCO3 por esclerobiontes en un arrecife sujeto a estrés antropogénico - Las Gatas (LG), en la bahía de Zihuatanejo Guerrero, y otro bajo condiciones ambientales altamente fluctuantes - La Llave (LL), en Bahía de Los Ángeles (Golfo de California). Métodos. Se utilizaron CAUs (Calcification/Accretion Units) para promover el reclutamiento de esclerobiontes durante dos periodos de inmersión: 6 y 15 meses. Resultados. La tasa de calcificación fue alta a los 6 meses y luego disminuyó debido a la rápida colonización y crecimiento inicial seguido de una disminución con el tiempo. Los esclerobiontes depositaron 1.2 ± 0.4 kg CaCO3 m-2 año-1 en LG, lo que representa el 7% de la producción de corales ramificados en el Pacífico sur mexicano (17.2 kg m-2 año-1), mientras que en LL depositaron 2.1 ± 0.7 kg CaCO3 m-2 año-1, equivalente al 20% de la producción de corales masivos en la zona (10.1 kg m-2 año-1). Los grupos que más CaCO3 depositaron fueron los moluscos y los briozoos en LG (hasta 0.65 ± 0.16 kg m-2 año-1), y los balanos en LL (hasta 2.32 ± 0.35 kg m-2 año-1). Conclusiones. Estos resultados destacan el papel de los heterótrofos como calcificadores secundarios tanto en LG, un sitio impactado por actividad antropogénica, como en LL, un sitio con bajo impacto antropogénico, pero con alta productividad biológica asociada a surgencias. Este hallazgo implica que las condiciones ambientales en los sitios de estudio limitan la calcificación de los calcificadores primarios (i.e., corales y CCA) pero estimulan la de calcificadores secundarios, con potenciales repercusiones geomórficas.

ABSTRACT Background. Coral reefs provide several important geo-ecological functions essential for the sustainability of coastal human communities. However, during the last 50 years, reef ecosystems are experiencing rapid degradation caused by natural and anthropogenic disturbances. One consequence of the above has been the reduction in the carbonate production rate and the structural complexity of these systems. Particularly, the loss of key coral species in the construction of reefs has compromised the functionality of the ecosystem. Objective. In this study we used an adaptation of the ReefBudget methodology to measure the calcium carbonate budget in the reef of La Entrega, Oaxaca, Mexico. Methods. Six transects were carried out to estimate the abundance of eroding fish (25 x 4 m), sea urchins (25 x 2 m) and the composition of the benthos. Results. When carrying out the corresponding calculations, it was found that in La Entrega 13.72 kg m-2 year-1 (commonly referred as “G”) are produced, the endobioerosion (including erosion by sponges) calculated was 5.65 G. The sea urchin erosion is 0.12 G and that of fish is 0.73 G; the resulting net carbonate budget was 7.21 G. The accretion rate (vertical reef growth) at La Entrega reef was 7.07 mm yr-1. We consider it important to mention that the reef patch at La Entrega is relatively small (approximately 324 x 233 m) compared to formations in the Caribbean or Indo-Pacific regions. Conclusions. Net production at La Entrega is higher than estimated for most Caribbean reefs (2-4 G) but lower than that of the Indo-Pacific (5-14 G). Differences in the balance between regions are mainly associated with differences in the abundances of builder species in each region. According to what was modeled in this work, the La Entrega reef patch presents a sufficient accretion rate to deal with a possible rise in sea level under the RCP 4.5 and 2.6 scenarios (4 and 7 mm, respectively).

RESUMEN Antecedentes. Los arrecifes de coral proporcionan diversas funciones geo-ecológicas importantes esenciales para la sostenibilidad de las comunidades humanas costeras. Sin embargo, durante los últimos 50 años, los ecosistemas arrecifales están experimentando una rápida degradación ocasionada por perturbaciones naturales y antropogénicas. Una consecuencia de lo anterior ha sido la reducción de la tasa de producción de carbonatos y la complejidad estructural de estos sistemas. Particularmente, la pérdida de especies coralinas clave en la construcción de arrecifes ha comprometido la funcionalidad del ecosistema. Objetivo. En este estudio utilizamos una adaptación de la metodología ReefBudget para medir el balance de carbonato de calcio en el arrecife de La Entrega, Oaxaca, México. Métodos. Se realizaron seis transectos para estimar la de abundancia de peces erosionadores (25 x 4 m), erizos (25 x 2 m) y la composición del bentos. Resultados. Al realizar los cálculos correspondientes, se encontró que en La Entrega se producen 13.72 kg m-2 año-1 (unidades comúnmente referidas con “G”), la endobioerosión (incluida la erosión por esponjas) calculada fue de 5.65 G. La erosión por erizos es de 0.12 G y la de peces es de 0.73 G; el balance neto de carbonatos resultantes fue de 7.21 G. La tasa de acreción (crecimiento vertical del arrecife) en el arrecife de La Entrega fue de 7.07 mm año-1. Consideramos importante mencionar que el parche arrecifal en La Entrega es relativamente pequeño (aproximadamente 324 x 233 m) en comparación con las formaciones de regiones del Caribe o el Indo-Pacífico. Conclusiones. La producción neta en La Entrega es superior a la estimada en la mayoría de los arrecifes del Caribe (2-4 G) pero más baja que la del Indo-Pacífico (5-14 G). Las diferencias en el balance entre regiones están, principalmente, asociadas a las diferencias en las abundancias de especies constructoras en cada región. De acuerdo con lo modelado en este trabajo, el parche arrecifal de La Entrega presenta una tasa de acreción suficiente para lidiar con una posible elevación en el nivel del mar bajo los escenarios RCP 4.5 y 2.6 (4 y 7 mm, respectivamente).

Abstract Ca2+ and Mg2+ ions are present in the water of the sulfide flotation process, negatively affecting its floatability and grade of the final concentrates obtained. It has recently been reported that its removal by adding sodium carbonate (Na2CO3) has a beneficial effect on flotation, although the reasons for this behavior are not yet known in detail. This paper presents the results of a study designed to investigate the reaction mechanism between the metal-carbonate ions. The results show that the addition of Na2CO3 to a saturated gypsum solution (0.016 mol/L) containing 50 ppm Mg(II) promotes the precipitation of the Ca2+ ion, such as calcite and vaterite. The kinetic model proposed to describe the reaction’s kinetics suggests that it is about a second order kinetic.

Resumen Los iones Ca2+ y Mg2+ se encuentran presentes en las aguas del proceso de flotación de sulfuros, lo que afecta negativamente su flotabilidad y el grado de los concentrados finales obtenidos. Recientemente se ha reportado que su remoción mediante la adición de carbonato de sodio (Na2CO3) tiene un efecto benéfico en la flotabilidad, aunque las razones de este comportamiento aún no se conocen con detalle. Este documento presenta los resultados de un estudio diseñado para investigar el mecanismo de reacción entre iones metal-carbonato. Los resultados demuestran que la adición de Na2CO3 a una solución saturada de yeso (0.016 mol/L) conteniendo 50 ppm de Mg(II), promueve la precipitación del ión Ca2+, como calcita y vaterita. El modelo cinético propuesto para describir la cinética de reacción sugiere que se trata de una cinética de segundo orden.

Abstract Algaroba wood (Prosopis juliflora) is commonly used as energy source in the northeast region of Brazil and India, generating rich-calcium carbonate (CaCO3) ashes as a promising alternative limestone filler. Moreover, concreting in hot climates (for example, in tropical regions) can affect its fresh state conditions owing to the evaporation of the mixing water. Thus, Self-Compacting Concretes (SCCs) incorporating Algaroba ashes were produced using heated dry materials (80 ± 2oC) to simulate hot weather mixing (on site, 50 ± 2oC). In order to simulate the hot weather conditions on site for subsequent control tests over time (in the laboratory), the specimens were cured in water at 20 ± 2oC. The self-compacting ability at the end of mixing was kept constant by extra water addition or superplasticizer overdosing. The partial replacement of 50% of natural lime filler by calcium-rich ash preserved the compressive strength and permeability of mixtures with 100% of limestone filler. Using 50% ash also demanded less water and superplasticizer when submitted to the simulated hot weather mixing. Prosopis juliflora India richcalcium rich calcium CaCO3 CaCO (CaCO3 Moreover example regions Thus SelfCompacting Self Compacting SCCs (SCCs 80 (8 2oC oC 5 . laboratory, laboratory , laboratory) 2 selfcompacting self compacting overdosing calciumrich 100 (CaCO 8 ( 10 1

A madeira de Algaroba (Prosopis juliflora) é comumente usada na região nordeste do Brasil e na Índia como matriz energética, gerando cinzas ricas em carbonato de cálcio (CaCO3), promissores fíleres calcários alternativos. Adicionalmente, concretar em climas quentes (por exemplo, em regiões tropicais) pode afetar o estado fresco devido à evaporação da água de mistura. Concretos Auto Adensáveis (CAAs) incorporando cinzas de Algaroba foram produzidos usando materiais secos aquecidos (80 ± 2 o C) para simular mistura sob clima quente (em obra, 50 ± 2 o C). A fim de simular as condições de clima quente em obra para posterior teste de controle ao longo do tempo (em laboratório), as amostras foram curadas em água a 20 ± 2 o C. A auto-adensabilidade foi mantida constante ao final das misturas pela adição de água extra ou superdosagem de superplastificante.A substituição parcial de 50% do fíler calcário por cinzas ricas em cálcio preservou a resistências à compressão e permeabilidade das misturas com 100% de fíler calcário. O uso de 50% de cinza também demandou menos água e superplastificante em condição simulada de mistura sob clima quente. Prosopis juliflora energética CaCO3, CaCO3 CaCO , (CaCO3) alternativos Adicionalmente exemplo tropicais CAAs (CAAs 80 (8 C 5 . laboratório, laboratório laboratório) autoadensabilidade auto adensabilidade superplastificanteA 100 (CaCO3 8 ( 10 (CaCO 1

Abstract The aim of this paper is s to expand the knowledge about the variability with which taphonomic agents impact on the archaeological record from the southern coast of the province of Santa Cruz, specifically, on the one that is part of shell middens found in the archaeological locality of Punta Entrada and Monte León National Park. For this, the lithic materials recovered in different exposure situations (stratigraphy and surface materials) which are dated in the Middle and Late Holocene are analyzed. Specifically, indicators of subaerial exposure and burial are used, such as the impact of wind erosion and the presence of calcium carbonate precipitates. Results are compared with the ones available for non-shell midden sites. It is concluded thatthere would be no differences in the way in which both taphonomic effects are expressed according to the kind of site that contains the artifacts.

Resumen El objetivo de este trabajo es ampliar el conocimiento acerca de la variabilidad con que los agentes tafonómicos impactan sobre el registro arqueológico proveniente de la costa meridional de la provincia de Santa Cruz, específicamente, de sitios concheros que se encuentran en la localidad arqueológica Punta Entrada y el Parque Nacional Monte León. Para ello se analizan los artefactos líticos recuperados en distinta situación de exposición (estratigrafía y materiales en superficie) recuperados en sitios concheros y datados en el Holoceno medio y tardío. Concretamente se utilizan indicadores de exposición subaérea y enterramiento como son el impacto de la erosión eólica y la presencia de precipitados de carbonato de calcio. Los resultados se comparan con los disponibles para sitios no concheros. Se concluye queno habría diferencias en la forma en la que se expresan ambos efectos tafonómicos según el tipo de sitiosen el que se hallan los artefactos.

Resumo As algas coralinas crustosas (Corallinophycideae) são algas vermelhas que produzem carbonato de cálcio e são bem reconhecidas como espécies de base na zona epipelágica do ecossistema marinho. Essas algas induziram o assentamento juvenil de coral por meio de estímulos químicos liberados por comunidades bacterianas na superfície de suas colônias. Seu carbonato de cálcio extracelular também pode estabilizar a estrutura do recife que influencia muitos invertebrados anexados e crescimento no fundo do mar. As algas coralinas crustosas (CCA) têm obtido atenção devido à sua distribuição e comprometimento da saúde com o aumento da temperatura da água do mar, acidificação dos oceanos e poluentes. Como uma espécie enigmática no ecossistema, a presença de recrutamento CCA às vezes não recebe atenção, especialmente em sua capacidade de ocupar o espaço vazio. Este estudo teve como objetivo documentar a cobertura e o número de recrutamento de CCA em dois materiais de recrutamento diferentes. A maior porcentagem de CCA da cobertura foi mostrada na superfície interna do que nas outras superfícies em todas as estações. A intensidade da luz e a baixa sedimentação foram sugeridas como um fator-chave para o sucesso da alta cobertura. De modo geral, recrutas de CCA mais graduados mostraram-se em Tiga Warna. A baixa sedimentação e a proteção contra a exposição aérea se tornaram a principal razão para isso. Não houve diferença significativa no número de recrutas CCA entre mármore e arenito neste estudo. O recrutamento bem-sucedido de CCA neste estudo pode dar uma imagem ampla de que o recrutamento natural de corais e outros recifes da biodiversidade no sul de Malang será bem-sucedido por causa da abundância de algas coralinas que sustentam seu estágio de história de vida.

Abstract Crustose coralline algae (Corallinophycideae) are red algae that produced calcium carbonate and are well recognized as foundation species in the epipelagic zone of the marine ecosystem. These algae induced settlement juvenile of coral by released chemical cues from bacterial communities on the surface of their colonies. Their extracellular calcium carbonate also can stabilize reef structure that influencing many invertebrate attaches and growth in the seabed. Crustose coralline algae (CCA) have obtained attention because of their distribution and health compromise to increasing seawater temperature, ocean acidification, and pollutant. As a cryptic species in the ecosystem, the presence of CCA recruit sometimes doesn’t have attention, especially on their capability to occupy the empty space. This study aimed to document coverage and number of CCA recruit in two different recruitment tile’s material. The highest CCA percentage of the cover was showed inside surface than others surface in all stations. Light intensity and low sedimentation were suggested as a key factor of success of high coverage. Overall, station higher CCA recruits have shown from Tiga Warna. Low sedimentation and protection from aerial exposure became the main reason for it. No significant difference number of CCA recruits between marble and sandstone in this study. Successful CCA recruitment in this study can give a wide picture that natural recruitment of coral and other reef biodiversity in Southern Malang might be will succeed because of the abundance of coralline algae that support their life history stage.

ABSTRACT Thirty-five groundwater samples from the aquifer were collected and analyzed for major cations and anions to understand the groundwater chemistry and hydrochemical processes in the Egbako aquifer. Laboratory studies identified the major ions while the results were analyzed using different graphical methods and ionic plots. The abundance of the major cations and anions are Ca2+>K+>Na+>Mg2+ and HCO3->NO3->Cl->SO42- respectively. The dominant hydrochemical facies are calcium-bicarbonate (Ca-HCO3), sodium-bicarbonate (Na-HCO3) and mixed calcium-sodium bicarbonate (Ca-Na-HCO3) water types. Interpretation of bivariate and scatter plots indicate silicate weathering, simple dissolution and ion exchange as the dominant processes in the aquifer. Saturation indices reveals evaporites (halite, gypsum and anhydrite) undersaturation, supersaturation in most samples with respect to silicates (quartz and kaolinite) and few samples for carbonate (calcite, aragonite, dolomite). Assessment of the water quality indicate that they are chemically suitable for human consumption except in the agricultural fields of southwestern areas where high nitrate concentration is present. Thirtyfive Thirty five Ca2KNaMg2 CaKNaMg Ca2 K Na Mg2 Ca Mg Ca2+>K+>Na+>Mg2 HCO3>NO3>Cl>SO42 HCO3NO3ClSO42 HCONOClSO HCO3 >NO3 >Cl >SO42 NO3 Cl SO42 HCO NO SO HCO3->NO3->Cl->SO42 respectively calciumbicarbonate calcium CaHCO3, CaHCO3 CaHCO , (Ca-HCO3) sodiumbicarbonate sodium NaHCO3 NaHCO (Na-HCO3 calciumsodium CaNaHCO3 CaNaHCO (Ca-Na-HCO3 types weathering halite, halite (halite anhydrite undersaturation quartz kaolinite calcite, calcite (calcite aragonite dolomite. dolomite . dolomite) present KNaMg Ca2KNaMg Ca2+>K+>Na+>Mg HCO3>NO3>Cl>SO4 ClSO HCO3NO3ClSO4 >NO >SO4 SO4 HCO3->NO3->Cl->SO4 (Ca-HCO3 (Na-HCO (Ca-Na-HCO HCO3>NO3>Cl>SO HCO3NO3ClSO >SO HCO3->NO3->Cl->SO (Ca-HCO

RESUMO Trinta e cinco amostras de água subterrânea do aquífero foram coletadas e analisadas para os principais cátions e ânions para entender a química e os processos hidroquímicos das águas subterrâneas no aquífero Egbako. Estudos laboratoriais identificaram os íons majoritários, enquanto os resultados foram analisados usando diferentes métodos gráficos e gráficos iônicos. A abundância dos cátions e ânions majoritários foram, respectivamente, Ca2+>K+>Na+>Mg2+ e HCO3->NO3->Cl->SO42-. As fases hidroquímicas dominantes são os tipos de água bicarbonato de cálcio (Ca-HCO3), bicarbonato de sódio (Na-HCO3) e bicarbonato de cálcio e sódio misto (Ca-Na-HCO3). A interpretação de gráficos bivariados e de dispersão indica o intemperismo do silicato, a dissolução simples e a troca iônica como os processos dominantes no aquífero. Os índices de saturação revelam subsaturação de evaporitos (halita, gesso e anidrita), supersaturação na maioria das amostras em relação aos silicatos (quartzo e caulinita) e poucas amostras de carbonato (calcita, aragonita, dolomita). A avaliação da qualidade da água indica que elas são quimicamente adequadas para o consumo humano, exceto nos campos agrícolas das áreas do sudoeste, onde há alta concentração de nitrato. Egbako iônicos respectivamente Ca2KNaMg2 CaKNaMg Ca2 K Na Mg2 Ca Mg Ca2+>K+>Na+>Mg2 HCO3>NO3>Cl>SO42. HCO3NO3ClSO42 HCONOClSO HCO3 >NO3 >Cl >SO42 . NO3 Cl SO42 HCO NO SO HCO3->NO3->Cl->SO42- CaHCO3, CaHCO3 CaHCO , (Ca-HCO3) NaHCO3 NaHCO (Na-HCO3 CaNaHCO3. CaNaHCO3 CaNaHCO (Ca-Na-HCO3) silicato halita, halita (halita anidrita, anidrita anidrita) quartzo caulinita calcita, calcita (calcita aragonita dolomita. dolomita dolomita) humano sudoeste nitrato KNaMg Ca2KNaMg Ca2+>K+>Na+>Mg HCO3>NO3>Cl>SO42 ClSO HCO3NO3ClSO4 >NO >SO4 SO4 HCO3->NO3->Cl->SO42 (Ca-HCO3 (Na-HCO (Ca-Na-HCO3 HCO3>NO3>Cl>SO4 HCO3NO3ClSO >SO HCO3->NO3->Cl->SO4 (Ca-HCO (Ca-Na-HCO HCO3>NO3>Cl>SO HCO3->NO3->Cl->SO