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Context: For regulatory reasons, a biowaiver is characterized as the substitution or exemption of bioavailability and/or bioequivalence research with in vitro dissolution tests, according to the Biopharmaceutical Classification System (BCS). These studies need validated quantification methods to give reliable results. Aims: To develop and validate the UV spectrophotometric method for biowaiver studies in pyrazinamide tablets. Methods: The parameters for validation, such as specificity, linearity, range, accuracy, precision, stability of the analytical solution, filter test, limits of detection, and quantification, were assessed according to the standards set by the guidelines of the International Conference on Harmonization and the United States Pharmacopeia. The dissolution operating conditions were 900 mL of dissolution media at pH 1.2, 4.5, and 6.8, with the paddle method at 75 rpm and sampling times of 5, 10, 15, 20, and 30 minutes. Results: The wavelength of maximum absorbance was 268 nm for the three dissolution media. The method was linear in the range of 1.11112–13.3334 µg/mL (r2>0.998). The limits of detection ranged from 0.0157 to 0.0222 µg/mL, and the limits of quantification were between 0.0415 and 0.0546 µg/mL. The recovered values were between 99.4 and 103.0%. No interference from the placebo was observed. The relative standard deviation values were less than 2% for precision. For robustness, different conditions were evaluated as wavelengths, changes in concentration, and Whatman No. 40, 41, and 42 filters; they did not modify the method response. The samples were kept unchanged for a period of 24 hours at 25°C. Conclusions: The UV spectrophotometric method was linear, accurate, specific, and precise in the concentration range studied and in the dissolution media at pH levels of 1.2, 4.5, and 6.8, being suitable for biowaiver studies in pyrazinamide tablets.

Many hydro-meteorological disasters in small and steep watersheds develop quickly and significantly impact human lives and infrastructures. High-resolution rainfall data and machine learning methods have been used as modeling frameworks to predict those events, such as flash floods. However, a critical question remains: How long must the rainfall input data be for an empirical-based hydrological forecast? The present article employed an artificial neural network (ANN)hydrological model to address this issue to predict river levels and investigate its dependency on antecedent rainfall conditions. The tests were performed using observed water level data and high-resolution weather radar rainfall estimation over a small watershed in the mountainous region of Rio de Janeiro, Brazil. As a result, the forecast water level time series only archived a successful performance (i.e., Nash–Sutcliffe model efficiency coefficient (NSE) > 0.6) when data inputs considered at least 2 h of accumulated rainfall, suggesting a strong physical association to the watershed time of concentration. Under extended periods of accumulated rainfall (>12 h), the framework reached considerably higher performance levels (i.e., NSE > 0.85), which may be related to the ability of the ANN to capture the subsurface response as well as past soil moisture states in the watershed. Additionally, we investigated the model’s robustness, considering different seeds for random number generating, and spacial applicability, looking at maps of weights.

Conocer los requerimientos germinativos de especies nativas y los factores ambientales que los controlan permite comprender la dinámica de las comunidades vegetales y respaldar programas de restauración. Los disturbios pueden alterar esas dinámicas al afectar el ambiente y la abundancia de los organismos que lo habitan. La recuperación del ambiente disturbado depende de las características de las especies involucradas en el proceso de sucesión ecológica. Cabe esperar que los tipos sucesionales de especies (i.e., colonizadoras, intermedias y tardías) tengan requerimientos para germinar y características fisiológicas distintas que les permiten cumplir sus roles en el proceso de sucesión. En este trabajo se evaluaron los requerimientos germinativos de diez especies nativas del Monte Patagónico clasificadas según su rol en la sucesión ecológica. Se estudiaron las condiciones que mejoran las tasas de germinación (i.e., porcentaje y tiempo de germinación) sometiendo a las semillas a diferentes tratamientos (C=control, E=escarificación, F=estratificación, O=oscuridad, R=remojo en agua, CA=calor, y sus combinaciones). Como se esperaba, los tipos sucesionales de especies respondieron diferente a los tratamientos germinativos. Las especies colonizadoras no presentan dormancia, ya que el tratamiento control germinó más que en el resto de los tratamientos. Las intermedias germinaron más rápido y en mayor cantidad con la escarificación, aunque el control también obtuvo una germinación similar. Las tardías presentaron mecanismos de dormancia, y la combinación de remojo en agua con oscuridad y estratificación fría húmeda fue el tratamiento de mayor germinación. Las colonizadoras e intermedias serían las más adecuadas para proyectos de restauración ecológica, ya que poseen mayores tasas de germinación y crecimiento, lo que promueve una cobertura vegetal rápida. Estas estrategias germinativas, que dependen de los tipos sucesionales de especies, son una contribución valiosa para acelerar la sucesión y desarrollar estrategias de restauración ecológica.

Serjania erecta Raldk is an essential genetic resource due to its anti-inflammatory, gastric protection, and anti-Alzheimer properties. However, the genetic and evolutionary aspects of the species remain poorly known. Here, we sequenced and assembled the complete chloroplast genome of S. erecta and used it in a comparative analysis within the Sapindaceae family. S. erecta has a chloroplast genome (cpDNA) of 159,297 bp, divided into a Large Single Copy region (LSC) of 84,556 bp and a Small Single Copy region (SSC) of 18,057 bp that are surrounded by two Inverted Repeat regions (IRa and IRb) of 28,342 bp. Among the 12 species used in the comparative analysis, S. erecta has the fewest long and microsatellite repeats. The genome structure of Sapindaceae species is relatively conserved; the number of genes varies from 128 to 132 genes, and this variation is associated with three main factors: (1) Expansion and retraction events in the size of the IRs, resulting in variations in the number of rpl22, rps19, and rps3 genes; (2) Pseudogenization of the rps2 gene; and (3) Loss or duplication of genes encoding tRNAs, associated with the duplication of trnH-GUG in X. sorbifolium and the absence of trnT-CGU in the Dodonaeoideae subfamily. We identified 10 and 11 mutational hotspots for Sapindaceae and Sapindoideae, respectively, and identified six highly diverse regions (tRNA-Lys — rps16, ndhC – tRNA-Val, petA – psbJ, ndhF, rpl32 – ccsA, and ycf1) are found in both groups, which show potential for the development of DNA barcode markers for molecular taxonomic identification of Serjania. We identified that the psaI gene evolves under neutrality in Sapindaceae, while all other chloroplast genes are under strong negative selection. However, local positive selection exists in the ndhF, rpoC2, ycf1, and ycf2 genes. The genes ndhF and ycf1 also present high nucleotide diversity and local positive selection, demonstrating significant potential as markers. Our findings include providing the first chloroplast genome of a member of the Paullinieae tribe. Furthermore, we identified patterns in variations in the number of genes and selection in genes possibly associated with the family’s evolutionary history.

Además de estrés por sequía, las plantas de climas áridos suelen sufrir herbivoría por grandes mamíferos. Esto puede repercutir en su fitness, por lo que a menudo despliegan respuestas o defensas para contrarrestar este efecto, desarrollando mecanismos de tolerancia y resistencia. En este trabajo investigamos cómo la sequía y la herbivoría afectan el crecimiento de plántulas de Atriplex lampa, una especie forrajera del Monte Patagónico. En invernadero evaluamos si el estrés por herbivoría simulada afecta la presencia de pulgones en esta especie; a campo estudiamos si la herbivoría por grandes mamíferos afecta la granivoría por insectos. Encontramos que la sequía no afectó el crecimiento de la especie, sugiriendo que A. lampa posee mecanismos de tolerancia y adaptación a este tipo de estrés, mientras que la herbivoría redujo su crecimiento. Además, hallamos que un aumento en el estrés sufrido por las plántulas y —en menor grado— por sus parentales (origen de la semilla) se relaciona con una menor presencia de pulgones en las plántulas cultivadas en invernadero. Sin embargo, a campo observamos que a mayor carga ganadera, mayor granivoría por insectos. Los resultados del experimento en invernadero sugieren que A. lampa desarrolla algún tipo de defensa o que el estrés por la sequía y la herbivoría simulada disminuyen la atracción por pulgones. Los resultados a campo sugieren que esta especie no genera defensas o que estas se encuentran principalmente en tallos y hojas, y no en frutos. Nuestros resultados evidencian que A. lampa ha desarrollado estrategias de tolerancia a la sequía, pero es vulnerable a la herbivoría. Estos factores de estrés podrían estar ejerciendo presiones de selección sobre A. lampa que afectan procesos evolutivos y ecológicos, y, en consecuencia, a sus servicios ecosistémicos como especie forrajera clave en la región del Monte.

La respuesta de las plantas a los disturbios se relaciona con sus características fisiológicas, sus formas de vida y su función dentro de la comunidad. Evaluamos la respuesta, en términos de biomasa y fecundidad, de los distintos tipos sucesionales de especies (colonizadoras, intermedias y tardías) del Monte Patagónico a un gradiente de carga ganadera (unidades ganaderas.año.ha-1). La biomasa la estimamos mediante el tamaño de las plantas consumidas (diámetro x altura) y la fecundidad a través del esfuerzo reproductivo (% de ramas reproductivas) y del porcentaje de semillas viables producido. Observamos que el ramoneo disminuyó la biomasa y la fecundidad de las plantas, tanto ramas reproductivas como semillas viables. Sin embargo, los tipos sucesionales de especies mostraron diferente producción de semillas viables en respuesta a la intensidad de pastoreo. Con el aumento del ganado se redujo el tamaño de especies colonizadoras, aumentó el de las intermedias, y el tamaño de las tardías no cambió significativamente. En general, el aumento del ramoneo afectó negativamente el esfuerzo reproductivo de todas las especies. A pesar de ello, las colonizadoras e intermedias aumentaron la producción de semillas viables, mientras que las tardías la disminuyeron. Estos resultados sugieren que las especies tardías son las más afectadas por el ganado en términos de fecundidad, lo que podría reducir su reclutamiento. El aumento de su biomasa con la carga ganadera en especies intermedias sugiere una respuesta compensatoria que podría otorgarles una ventaja a corto plazo. La pérdida de tejido que sufren las plantas por consumo del ganado impacta en la cantidad de semillas, pero, además, podría tener consecuencias en la tasa y el momento de germinación de la progenie. Los resultados ayudan a comprender la dinámica de las comunidades frente a los disturbios, y aportan información útil para elaborar estrategias de manejo y restauración de ecosistemas áridos.

Haemulidae is a widely diverse and widespread family of New World teleost fish. The Peruvian grunt, Anisotremus scapular, inhabits the South American Pacific coast where its overexploitation for human consumption. Fishing has led to the populational decline of the species and raised the need for conservation and aquaculture developments. Here we describe the complete mitogenome of the Peruvian grunt assembled from an RNA-seq dataset. The mitogenome length is 16,785 bp and, as expected for a vertebrate, composed of 13 PCGs, 22 transfer RNA, 2 ribosomal RNA genes. Phylogenetic reconstruction, including all available 25 Lutjaniformes mitogenomes, places A. scapularis within the family Haemulidae, more precisely within the subfamily Haemulinae. Furthermore, paraphyletic relationships were observed within the other groups represented in the phylogeny. Overall, our results highlight the usefulness of using mitochondrial genomes for phylogenetic analysis in Haemulinae as well as the necessity to increase taxonomic sampling within the group.

Climate change is increasing the frequency and severity of short-term (~1 y) drought events-the most common duration of drought-globally. Yet the impact of this intensification of drought on ecosystem functioning remains poorly resolved. This is due in part to the widely disparate approaches ecologists have employed to study drought, variation in the severity and duration of drought studied, and differences among ecosystems in vegetation, edaphic and climatic attributes that can mediate drought impacts. To overcome these problems and better identify the factors that modulate drought responses, we used a coordinated distributed experiment to quantify the impact of short-term drought on grassland and shrubland ecosystems. With a standardized approach, we imposed ~a single year of drought at 100 sites on six continents. Here we show that loss of a foundational ecosystem function-aboveground net primary production (ANPP)-was 60% greater at sites that experienced statistically extreme drought (1-in-100-y event) vs. those sites where drought was nominal (historically more common) in magnitude (35% vs. 21%, respectively). This reduction in a key carbon cycle process with a single year of extreme drought greatly exceeds previously reported losses for grasslands and shrublands. Our global experiment also revealed high variability in drought response but that relative reductions in ANPP were greater in drier ecosystems and those with fewer plant species. Overall, our results demonstrate with unprecedented rigor that the global impacts of projected increases in drought severity have been significantly underestimated and that drier and less diverse sites are likely to be most vulnerable to extreme drought.

Students who are the first in their families to attend college and have Deferred Action for Childhood Arrivals (DACA) status, question whether they will be welcomed, accepted, and safe in their relationships and on campus. Setting the stage for this paper, the authors provide definitional overviews of DACA, first-generation to college status, and Latinx as foundational information for working with and mentorship. Next, the article presents the theoretical model and discussion of experiences of many Latinx first-generation college undocumented/DACAmented students' sense of belonging in higher education. The authors end with implications and recommendations for university personnel.

We examine the impact of credit mobility exchange programs' timing on students' academic performance, focusing on the moment in which students travel and the length of the period spent abroad. To provide causal evidence, we exploit unique data from more than 10,000 students from a well-known and internationalized Brazilian university from 2010 to 2020. By combing Propensity Score Matching with Difference in Differences techniques, we find that international mobility impacts groups of students differently. Students who travel closer to the end of their undergraduate courses benefit the most from the mobility experience, while negative effects are found for those who travel at the beginning of their university program. Results also show that, while student mobility impacts positively and significantly students who participate in programs lasting from one semester to 1 year, negative effects are associated with shorter periods abroad. Our findings also reveal heterogeneity across destination countries. Mobility has a positive impact on students' grades for those students traveling to English-speaking countries. Our analysis presents empirical evidence that can be used to design international student mobility programs, providing insights to policymakers engaged in maximizing their effects.