A reply to "Relevant factors in the eutrophication of the Uruguay River and the Río Negro".

A recent paper by Beretta-Blanco and Carrasco-Letelier (2021) claims that agricultural eutrophication is not one of the main causes for cyanobacterial blooms in rivers and artificial reservoirs. By combining rivers of markedly different hydrological characteristics e.g., presence/absence and number of dams, river discharge and geological setting, the study speculates about the role of nutrients for modulating phytoplankton chlorophyll-a. Here, we identified serious flaws, from erratic and inaccurate data manipulation. The study did not define how erroneous original dataset values were treated, how the variables below the detection/quantification limit were numerically introduced, lack of mandatory variables for river studies such as flow and rainfall, arbitrary removal of pH > 7.5 values (which were not outliers), and finally how extreme values of other environmental variables were included. In addition, we identified conceptual and procedural mistakes such as biased construction/evaluation of model prediction capability. The study trained the model using pooled data from a short restricted lotic section of the (large) Uruguay River and from both lotic and reservoir domains of the Negro River, but then tested predictability within the (small) Cuareim River. Besides these methodological considerations, the article shows misinterpretations of the statistical correlation of cause and effect neglecting basic limnological knowledge of the ecology of harmful algal blooms (HABs) and international research on land use effects on freshwater quality. The argument that pH is a predictor variable for HABs neglects overwhelming basic paradigms of carbon fluxes and change in pH because of primary productivity. As a result, the article introduces the notion that HABs formation are not related to agricultural land use and water residence time and generate a great risk for the management of surface waterbodies. This reply also emphasizes the need for good practices of open data management, especially for public databases in view of external reproducibility.

Improved biovolume estimation of Microcystis aeruginosa colonies: A statistical approach.

The Microcystis aeruginosa complex (MAC) clusters many of the most common freshwater and brackish bloom-forming cyanobacteria. In monitoring protocols, biovolume estimation is a common approach to determine MAC colonies biomass and useful for prediction purposes. Biovolume (µm3 mL-1) is calculated multiplying organism abundance (orgL-1) by colonial volume (µm3org-1). Colonial volume is estimated based on geometric shapes and requires accurate measurements of dimensions using optical microscopy. A trade-off between easy-to-measure but low-accuracy simple shapes (e.g. sphere) and time costly but high-accuracy complex shapes (e.g. ellipsoid) volume estimation is posed. Overestimations effects in ecological studies and management decisions associated to harmful blooms are significant due to the large sizes of MAC colonies. In this work, we aimed to increase the precision of MAC biovolume estimations by developing a statistical model based on two easy-to-measure dimensions. We analyzed field data from a wide environmental gradient (800 km) spanning freshwater to estuarine and seawater. We measured length, width and depth from ca. 5700 colonies under an inverted microscope and estimated colonial volume using three different recommended geometrical shapes (sphere, prolate spheroid and ellipsoid). Because of the non-spherical shape of MAC the ellipsoid resulted in the most accurate approximation, whereas the sphere overestimated colonial volume (3-80) especially for large colonies (MLD higher than 300 µm). Ellipsoid requires measuring three dimensions and is time-consuming. Therefore, we constructed different statistical models to predict organisms depth based on length and width. Splitting the data into training (2/3) and test (1/3) sets, all models resulted in low training (1.41-1.44%) and testing average error (1.3-2.0%). The models were also evaluated using three other independent datasets. The multiple linear model was finally selected to calculate MAC volume as an ellipsoid based on length and width. This work contributes to achieve a better estimation of MAC volume applicable to monitoring programs as well as to ecological research.

Quality and stability of oral extemporaneous formulations developed from commercial tablets containing spironolactone / Desenvolvimento e estudo de estabilidade de formulações extemporâneas de uso oral a partir de comprimidos comerciais contendo espironolactona

The purpose of this study was to develop extemporaneous liquid pharmaceutical formulations from commercial tablets containing spironolactone and to assess their stability for use in children or adults with difficulty in swallowing. The content and stability of spironolactone in the tablets, as well as in water, 1.5% carboxymethylcellulose (CMC) or simple syrup dispersions were determined by high performance liquid chromatography (HPLC) analysis on a C18 silica column (250 mm ? 4.6 mm ? 5 ?m), with a mobile phase of methanol:water (75:25 v/v), flowing at 1 mL/min, and UV detection at 240 nm. The extemporaneous formulations were tested over a 35-day period at 8, 27, and 40 ºC. Drug content in the aqueous dispersion was far lower than expected, with significant fluctuations at all temperatures, owing to rapid sedimentation. The content proved adequate in aqueous 1.5% CMC dispersion at 27 ºC, with undesirable variations at the other temperatures. The syrup-based dispersion remained stable at all three temperatures, with suitable drug content and no significant variability. No degradation products were observed in any of the formulations. The syrup-based dispersion is easy to prepare, self-preserving, stable, palatable, offering satisfactory drug content per dose, and can therefore be recommended as an extemporaneous formulation for enhancing treatment adherence and effectiveness...

O objetivo desse trabalho foi desenvolver e avaliar a estabilidade de formas farmacêuticas líquidas extemporâneas, a partir de amostras comerciais (comprimidos), contendo espironolactona, para que possam ser empregadas em pacientes pediátricos ou adultos com dificuldade de deglutição. A metodologia empregada para a análise do teor e da estabilidade do fármaco espironolactona nos comprimidos e nas dispersões utilizando água, carboximetilcelulose (CMC) 1,5% e xarope simples foi a Cromatografia Líquida de Alta Eficiência (CLAE), utilizando coluna de sílica C18 (250 mm x 4,6 mm x 5 μm), fluxo de 1 mL/min, comprimento de onda 240 nm e fase móvel metanol:água (75:25 v/v). As formulações extemporâneas foram analisadas durante 35 dias nas temperaturas de 8, 27 e 40 ºC. A dispersão aquosa apresentou teor muito abaixo do esperado, com variações significativas em todas as temperaturas, devido à rápida sedimentação. A dispersão aquosa de CMC 1,5% apresentou teor adequado na temperatura de 27 ºC com variações indesejadas nas demais temperaturas. A dispersão de xarope simples apresentou-se estável nas três temperaturas, com teor adequado e sem variações significativas. Não foi observado produto de degradação em nenhuma das formulações propostas. Por ser de fácil preparação, autoconservante, estável e de sabor agradável, a dispersão de xarope simples é a formulação extemporânea recomendada, pois garante teor satisfatório por dose e, portanto, favorece aumento à adesão e à eficácia do tratamento...

Determination of Cu, Ni, and Zn in fuel ethanol by FAAS after enrichment in column packed with 2-aminothiazole-modified silica gel.

This work describes the synthesis and characterization of 2-aminothiazole-modified silica gel (SiAT), as well as its application for preconcentration (in batch and column technique) of Cu(II), Ni(II) and Zn(II) in ethanol medium. The adsorption capacities of SiAT determined for each metal ion were (mmol g(-1)): Cu(II)=1.20, Ni(II)=1.10 and Zn(II)=0.90. In addition, results obtained in flow experiments, showed a recovery of ca. 100% of the metal ions adsorbed in a column packed with 500 mg of SiAT. The eluent was 2.0 mol L(-1) HCl. The sorption-desorption of the studied metal ions made possible the development of a preconcentration method for metal ions at trace level in fuel ethanol using flame AAS for their quantification.

[Telling a beautiful story: the trajectory of the Brazilian Nurses Association-Bahia]. / Contando uma bela história: a trajetória da ABEn-Bahia.

This study presents the story of the Brazilian Association of Nursing in Bahia federal state. It parallels the trajectory of this association to the history of the National Brazilian Association of Nursing, pointing out the most important events in its fifty-three years of work. It is clear that the history of the Brazilian Association of Trained Nurses (ABED)/ABEn-Bahia begins with the foundation of the Nursing School of the Federal University of Bahia. Teachers at this university, who were nurses in their home states, and had participated in other associations previously, were motivated to create a new branch of ABEn in Bahia. The branch of ABEn in the city of Feira de Santana-Bahia, had a similar trajectory, since it was also founded after the creation of the State University of Feira de Santana. The branch of ABEn in Bahia is considered a democratic association, which is attentive to the claims of the nursing professionals, the health of the Brazilian population and also to the strengthening of the organization.

Prevalence and risk of cysticercosis and taeniasis in an urban population of soldiers and their relatives.

To determine markers of Taenia solium transmission and risk factors in an urban community, we studied 1,000 soldiers from a military camp in Mexico City and their relatives. Serum samples were used to detect antigens and antibodies and fecal specimens were examined for Taenia coproantigens and helminth eggs. Prevalences of 12.2% and 5.8% for cysticercosis were found among soldiers and their relatives, respectively. Taeniasis was found in 0.5% and none of the groups, respectively. Relatives of soldiers positive for cysticercosis and taeniasis markers ate more pork from street stores than restaurants or markets compared with relatives of soldiers without these indicators of infection. Also, 12.0% of the relatives of positive soldiers had a history of expelling tapeworm proglottids in the feces in contrast to 3.7% of the family members of the control group. Prevalence values and risk factors in this urban population are similar to those of previous studies performed in rural populations.

[Evaluation of the safety and effectiveness of WHR-1142A in the treatment of non-specific acute diarrhea]. / Valoración de la seguridad y eficacia del WHR-1142A en el tratamiento de la diarrea aguda inespecífica.

A randomized double-blind placebo controlled trial of the safety and efficacy of lidamidine hydrochloride (WHR-1142A) in thirty patients with acute nonspecific diarrhea was conducted. During their 29-hour hospital treatment period, the average number of bowel movements for each ten patient treatment group was: placebo, 5.1: lidamidine hydrochloride (10 mg), 2.4; lidamidine hydrochloride (18 mg), 2.5. The average weight of the feces of the patients in each treatment group was: placebo, 576 grams; lidamidine hydrochloride (10 mg), 364 grams; lidamidine hydrochloride (18 mg), 435 grams. Time intervals between each of the first two doses were greater for those patients in the active treatment groups (lidamidine hydrochloride) when compared to the placebo group. Overall evaluation of therapy was rated by physician and patient at end of study: placebo, 10 of 10, not effective; lidamidine hydrochloride (10 mg), 10 of 10 (100%) effective; lidamidine hydrochloride (18 mg), 10 of 10 (100%) effective. Vital signs and laboratory values remained within normal ranges throughout the duration of study, and no clinically significant adverse effects were reported.