National University of the Northeast

An offline methodology is applied to estimate parameters of a subgrid-scale non-orographic gravity-wave scheme using observations from constant-level balloons. The approach integrates the Ensemble Kalman Filter (EnKF) with an iterative parameter estimation method based on the expectationmaximization (EM) algorithm. The meteorological fields required for the parameterization offline are taken from the ERA5 reanalysis, corresponding to the instantaneous meteorological conditions found underneath the Strateole-2 balloon observations made in the lower tropical stratosphere from November 2019 to February 2021 and October 2021 to January 2022. Compared to a direct approach that minimizes a cost function and uses Bayesian inference of parameters, our analysis demonstrates that the EnKF/EM method effectively characterizes the launching amplitudes and altitudes of the parameterized gravity waves and while quantifying their associated uncertainties. Furthermore, we illustrate how the method can help improving a scheme, specifically the results indicate that introducing a background wave activity renders the convective wave parameterization more realistic.

Estimation of surface soil moisture (SSM) is fundamental for hydrological monitoring and agricultural management, particularly in regions affected by recurrent droughts such as central–northeastern Argentina. Data assimilation techniques provide a robust approach to estimating SSM variability by integrating numerical soil models—i.e., land surface models—with observations from satellite-based remote sensors. Satellite missions based on L-band microwave sensors, such as NASA’s SMAP and ESA’s SMOS, provide global SSM retrievals, yet these observations often exhibit systematic biases arising from instrument noise, indirect measurements (i.e., observational operator), and temporal and spatial heterogeneities. Within data assimilation techniques, the ensemble Kalman filter (EnKF) has been widely employed for SSM estimation. This algorithm assumes unbiased observations; thus, bias correction becomes necessary to ensure optimal assimilation. In this study, we evaluate three off-line observational bias-correction techniques within a land data assimilation framework based on the Noah-MP v4.0.1 land surface model and an EnKF. The assessment focuses on the 2022 dry season over the endorheic Pampas region. We introduce a bias correction approach to mitigate sampling errors in cumulative distribution function (CDF) matching: (i) the climatological statistics are computed using homogeneous soil texture pixels within the bin, and (ii) a 45-day moving temporal sampling window is used to give a smoother evolution of the CDF. During dry periods, we empirically demonstrate that soil moisture probability density functions are statistically distinguishable across different soil textures within the bin. Furthermore the monthly-fixed statistics exhibited jumps during the dry season. This approach is compared with the standard CDF matching and the normal deviate scaling. These three off-line bias correction techniques are applied to correct SMAP and SMOS satellite retrievals prior to data assimilation. We show that this improved statistical sampling for CDF matching has a non-negligible impact on the SSM estimates resulting from EnKF, particularly during dry periods. The corrected sampling of CDF matching shows better alignment and stronger correlation with the time series of the independent in-situ soil moisture measurements. Overall, the study emphasizes the need for context-aware bias-correction techniques to enhance SSM data assimilation in regions with strong seasonal precipitation variations. Moreover, SSM estimations influence deeper model layers through vertical propagation of the information. These results motivate future work exploring how surface corrections might lead to enhanced subsurface estimates.

ABSTRACT Although numerous studies have examined reproductive strategies in weedy species, many have overlooked the influence of plant size on resource allocation patterns. Resource investment in Cyperus esculentus , measured as allocation to sexual structures and clonal propagules (tubers), was assessed at the genet level in a potted experiment under two contrasting light‐availability conditions, using three clonal populations from northeastern Argentina. It was found that shading consistently reduces both sexual and clonal reproduction, along with declines in genet size, while the relative investment in leaf mass remains invariant. Both sexual and clonal mass are strongly dependent on genet size under shade, where resource availability for growth is limited. Under full sun, no evidence appears for a linear relationship between genet size and either sexual or tuber mass; nevertheless, the reallocation of resources and meristems towards clonal expansion (i.e., the production of new ramets) may influence both reproductive functions. No association is evident between reproductive allocation plasticity across populations and fitness traits (represented by sexual and clonal mass); differences in reproduction among populations arise from variation in vegetative size rather than allocation strategy. A minimum genet size is required for both sexual reproduction and tuber production. Although no significant phenotypic correlation is found between sexual and clonal allocations, the negative relationship between sexual allocation and mean tuber size suggests that a trade‐off exists between the two reproductive functions. A thorough understanding of size‐dependent reproductive relationships in Cyperus esculentus has significant implications for its control and preventive management.

Phospholipases A2 (PLA2s) are key mediators of the cytotoxic and inflammatory activities of snake venoms. While PLA2 isoforms from Bothrops diporus venom have been characterized and shown to possess antimetastatic and antiangiogenic properties, their impact on mitochondrial bioenergetics and immune modulation has not yet been investigated. In this study, we examined the bioenergetic and immunomodulatory effects of B. diporus PLA2s using integrated biochemical, metabolic, and multiplex cytokine analyses. In MDA-MB-231 breast cancer cells, pooled PLA2s induced a dose-dependent decrease in MTT-reducing activity, increased mitochondrial ROS, caused Δψm hyperpolarization, and decreased NADH autofluorescence, collectively indicating sustained mitochondrial stress. Real-time impedance measurements further revealed a marked inhibition of cell proliferation. In human PBMCs, pooled PLA2s elicited a dynamic cytokine program, inducing early cytotoxic (Granzyme B) and chemotactic (CCL2, CCL3, CCL4) mediators, followed by late pro-inflammatory and regulatory factors such as IL-6, TNF-β, IL-10 and IL-15. Analysis of a single purified PLA2 isoform (Fraction 6) confirmed activation of the canonical IL-6/TNF-α/IL-1β axis but uniquely induced IL-10 and CCL20, revealing isoform-specific immunomodulatory properties. Altogether, these findings provide the first integrated characterization of mitochondrial and immune perturbations induced by B. diporus PLA2s, expanding their recognized biological scope and underscoring their potential as molecular templates for novel pharmacological strategies targeting mitochondrial vulnerabilities or modulating the tumor immune microenvironment.

Climate change is expected to intensify biodiversity loss through increasing aridity, but the potential of humid microhabitats to buffer these effects in tropical lowlands remains poorly understood. To address this gap, we surveyed 326 plots across 14 localities along a natural humidity gradient in northeastern Argentina, comparing fern diversity between climatically driven zonal habitats and more humid topographically or edaphically influenced azonal habitats. We found that azonal habitats supported greater fern richness than zonal ones in humid to semihumid regions, but this advantage disappeared towards the arid extreme, where both habitat types hosted equally poor communities. At the species level, only Christella hispidula and Doryopteris pentagona showed higher frequency patterns in azonal habitats toward drier conditions, whereas most species were more frequent in zonal habitats or showed no clear shift. Annual precipitation best explained variation in species richness, and soil conditions, such as salinity or unsuitable textures, may limit the capacity of azonal habitats to act as refugia under dry climates. Our findings reveal that humid microhabitats can act as refugia for ferns only under favorable moisture conditions, highlighting the need to account for local environmental heterogeneity and edaphic limitations when predicting biodiversity persistence under climate change.

Abstract The growing demand for plant-based proteins has prompted the exploration of alternative sources such as cowpea ( Vigna unguiculata ), due to its high protein content (23-25%). This study compared two protein extraction methods: 1-the pH-shift method at pH 7.5, 8.0, and 9.0, and at the natural pH of the cowpea flour–water dispersion (pH 6.4); 2- pH-shift protein extraction assisted by high-intensity ultrasound (HIUS; 400 W, 60 min, pulse 2 s on/2 s off, T < 30 °C). Protein yield, structural modifications, thermal stability, and techno-functional properties were assessed. Protein content ranged from 77.85% to 83.0%. HIUS increased yield at all pH conditions, including at pH 6.4. HIUS induced partial unfolding, increased surface hydrophobicity, and decreased thermal stability as a function of pH-shift extraction. These structural changes improved solubility at pH 6.0 and enhanced emulsifying capacity, especially in I7.5-US and I8-US, forming emulsions with smaller droplet sizes. I6.4-US was particularly attractive, providing yields and solubility comparable to or higher than I9 while avoiding the use of highly alkaline solutions. Although HIUS-assisted extraction slightly reduced protein purity due to co-extraction of non-protein compounds, it represents a simpler and more sustainable approach. This strategy supports the development of plant-based protein ingredients with high functionality and reduced chemical usage.

The Iberá Wetlands in northeastern Argentina constitute the second largest wetland system in South America, yet the fern and lycophyte flora of this region remains poorly documented. The aims of this work were to update the species richness of these plant groups, evaluate the intensity of collecting efforts, identify conservation priorities, estimate the potential true species richness, and make biogeographical inferences. We compiled a database of species from multiple sources, and the study area (21,853 km2) was divided into 19 grid cells for analysis. Sampling effort and species richness were quantified, and non-parametric estimators (Chao2, ICE, Jack2) were used to evaluate inventory completeness. Several similarity analyses were performed using the Jaccard index, incorporating reference areas from the Chaco and Paranaense phytogeographic provinces. The Ituzaingó–La Paz geological fracture and the geological formations present in the area were also considered. We recorded 76 taxa, whereas estimators suggested a potential richness of 130–140 species. The center of the Iberá Wetlands showed the lowest sampling effort, while the eastern sector exhibited the highest species richness. The distribution of species appears to be correlated with geological formations. These findings emphasize the importance of continuing sampling in the area.

Since 2023, librarians at The Ohio State University and the University of New Mexico have been collaborating on a project, including “Outdated Research Notions” workshops, to identify information literacy practices that may no longer work as well as we’d like.1 This article, along with the companion piece “Outdated Notion? Teaching Plagiarism as Theft,” by Jane Hammons, provides an overview of an “outdated notion” that has generated significant discussion among our workshop participants. Our piece explores one of the more evocative topics from our series: the use of scholarly articles in teaching undergraduates