Ensenada Institute of Technology

Poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch) is the worldwide symbol of Christmas, and its demand constantly grows. The main challenge in the poinsettia in vitro propagation protocol is maintaining aseptic conditions in the culture, as the latex present in poinsettia stems significantly contributes to carbohydrates and other molecules that promote the development of endogenous phytopathogens in the culture medium after establishment. Therefore, the primary objective of this work is to assess the efficacy in achieving an aseptic in vitro culture by the addition of AgNPs at six concentrations (0, 100, 200, 300, 400, 500, and 600 mg/L) to the MS culture medium. Entirely aseptic nodal segments were obtained with the addition of 300 to 600 mg/L of AgNPs. The best shoot induction and growth promotion was obtained with the addition of 400 mg/L to the medium, without compromising explant viability. It is essential to note that shoot induction and growth promotion were achieved without the addition of 6-benzylaminopurine (BA) or naphthalene acetic acid (NAA), which have previously been reported as the optimal conditions for poinsettia micropropagation. These results highlight the potential of AgNPs to accomplish both tasks in the in vitro establishment of poinsettia cultures: eliminating bacterial and fungal contamination and promoting conditions for shoot induction and growth. Silver nanoparticles ensure aseptic conditions in the culture, stimulate growth, and preserve all specimens of Euphorbia pulcherrima Willd. ex Klotzsch var. Belén alive without the addition of cytokinin or auxins.

This study evaluated the water supply and regulation of the San Pedro River basin, located in the municipality of Puerto Libertador (Córdoba, Colombia), under climate change scenarios, using the SWAT (Soil and Water Assessment Tool) hydrological model. The model was calibrated and validated in SWAT-CUP using the SUFI-2 algorithm, based on observed streamflow series and sensitive hydrological parameters. Observed and satellite climate data, CHIRPS for precipitation and ERA5-Land for temperature, radiation, humidity, and wind, were employed. Climatic data were integrated along with spatial information on soils, land use, and topography, allowing for an adequate representation of the basin’s heterogeneity. The model showed acceptable performance (NSE > 0.6; PBIAS < ±15%), reproducing the seasonal variability and the average flow behavior. Climate projections under RCP 4.5 and RCP 8.5 scenarios, derived from the MIROC5 model (CMIP5), indicated a slight decrease in mean streamflow and an increase in interannual variability for the period 2040–2070, suggesting a potential reduction in surface water availability and natural hydrological regulation by mid-century. The Water Regulation Index (WRI) exhibited a downward trend in most sub-basins, particularly in areas affected by forest loss and agricultural expansion. The WRI showed a downward trend in most sub-basins, especially those with loss of forest cover and a predominance of agricultural uses. These findings provide basin-specific evidence on how climate change and land-use pressures may jointly affect hydrological regulation in tropical Andean–Caribbean basins. These results highlight the usefulness of the SWAT model as a decision-support tool for integrated water resources management in the San Pedro River basin and similar tropical Andean–Caribbean catchments, supporting basin-scale climate adaptation planning. They also emphasize the importance of conserving headwater ecosystems and forest cover to sustain hydrological regulation, reduce vulnerability to flow extremes, and enhance long-term regional water security.

To synthesize current evidence on sexual dimorphism in maximal fat oxidation (MFO) and its corresponding exercise intensity (FATmax), exploring key moderators influencing these parameters across populations. We conducted a systematic review and meta-analysis, registered in PROSPERO (CRD42024563620), following Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. PubMed, Scopus, and EBSCOhost databases were searched from January 2001 to April 2024 for English- and Spanish-language studies examining MFO and FATmax during graded exercise tests. Studies were included if they reported sex-specific MFO and/or FATmax values derived from indirect calorimetry. Both cross-sectional and longitudinal designs were considered. Exclusion criteria included pooled-sex data, inaccessible full texts, and nonexercise-based MFO assessments. Thirty-six studies (n = 8,990; 5,133 females, 3,857 males) were included. Absolute MFO was significantly lower in females (MD: -0.06g/min), but no significant differences were observed in relative MFO (standardized mean difference: 0.202, p = .096) or FATmax (mean difference: 1.29% VO2max, p = .254). Cardiorespiratory fitness, body mass index, and exercise modality were key moderators in both sexes. Treadmill exercise was associated with higher MFO, irrespective of sex. Notably, body mass index and age influenced sexual dimorphism in fat oxidation, with age showing a curvilinear (quadratic) relationship with FATmax, suggesting complex age-related adaptations (p = .008). This review questions the assumption that women consistently oxidize more fat than men during exercise. The influence of sex on fat metabolism appears context-dependent, emphasizing the need for individualized interpretation. Longitudinal studies are required to evaluate whether these differences confer cardiometabolic protection.

Two new species of nereidids, Namalycastis solenotognatha sp. nov. and Nereis dhritiae sp. nov. are described in the present paper. These species were collected from two different locations along the intertidal zones, which are situated near mangrove habitats and sandy beaches, respectively. Namalycastis solenotognatha sp. nov. can be distinguished from its resembling congeners from Indian waters mainly by having heterogomph spinigers in supra-preacicular neurochaeta in anterior chaetigers, and lacking notochaetae. Other features related to the size (antennae, eyes, postero-dorsal tentacular cirri, and neuropodial superior lobe) and shape (heterogomph falcigers and spinigers’ blades, and pygidium) of several prostomial and parapodial structures, as well as the number of canals in the jaws, help distinguish the new species. Further, N. dhritiae sp. nov. differs from the three infra group I.B.2 species recorded from India by the presence of a distinct tendon in the blades of notopodial homogomph falcigers, one paragnath on area V, and an anterior row of area VII–VIII with only small paragnaths. Namalycastis solenotognatha sp. nov. and Nereis dhritiae sp. nov. increase the total number of Nereididae species to 73 from the Indian coast, five species belonging to Namalycastis and nine to Nereis.

ABSTRACT Magnetic cataclysmic variables of the intermediate polar (IP) subclass display a wide range of variability across different wavelengths. In late 2024 October/early November, the IP V709 Cas was observed over 10 nights by the OPtical TIming CAMera at the San Pedro Mártir Observatory in simultaneous three-colour (g, r, and i, or z band) photometry. On two of these nights, V709 Cas was simultaneously observed by the Neutron star Interior Composition ExploreR X-ray telescope. A periodogram analysis of the optical g- and r-band light curves reveals no prominent features at the white dwarf (WD) spin, but prominent features at the spin-orbit beat. In contrast, the X-ray and near-infrared (near-IR) i- and z-band periodograms show prominent features at the spin, but not the spin-orbit beat. Optical beat and near-IR spin pulsations have been seen in the IP PQ Gem, with simultaneous circular polarization detected in the near-IR, indicating cyclotron origin. We therefore speculate that we are seeing cyclotron radiation from V709 Cas, possibly adding it to the small group of cyclotron-emitting IPs. Combining analytical approximations with our expectation for cyclotron harmonics in the near-IR, we suggest a WD magnetic field strength of $10~{\rm MG} < B < 40$ MG.

Santa Ana winds are extreme meteorological events that strongly affect the U.S.–Mexico border region, often associated with droughts, high fire risk, and hydrological imbalance. Understanding the temporal behavior of key atmospheric variables during these events is crucial for integrated water resource management in semi-arid regions such as the Guadalupe Basin in northern Baja California. In this study, we explored the predictive capability of several hybrid deep learning architectures—Long Short-Term Memory (LSTM), Convolutional Neural Network combined with LSTM (CNN–LSTM), and Bidirectional LSTM with Attention (BiLSTM–Attention)—to model the temporal evolution of wind speed, wind direction, temperature, relative humidity, and atmospheric pressure using Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) reanalysis data from 1980 to 2020. Model performance was evaluated using RMSE, MAE, and R2 metrics and compared against persistence and climatology baselines. The BiLSTM–Attention model achieved the best overall performance, showing particularly high accuracy for temperature (R2 = 0.95) and relative humidity (R2 = 0.76), while maintaining angular errors below 35° for wind direction. The results demonstrate the potential of hybrid deep learning models to capture nonlinear temporal dependencies in meteorological time series and provide a methodological framework to enhance hydrometeorological understanding and water resource management in the Guadalupe Basin under Santa Ana wind conditions.

La tecnología InSAR satelital es una herramienta poderosa para detectar las laderas inestables y caracterizar los patrones espaciales y temporales de su desplazamiento. En este estudio, se han utilizado dos enfoques de InSAR multitemporal (MT-InSAR), SBAS e IPTA, para evaluar el estado de actividad de los deslizamientos del corredor costero Tijuana-Ensenada, Baja California, en la región de Salsipuedes, después de nueve años de trabajos de estabilización. Para ello, se utilizaron 61 imágenes de Sentinel-1A adquiridas en paso orbital descendente entre diciembre de 2021 y diciembre de 2023. Los resultados obtenidos permitieron identificar cuatro deslizamientos activos, tres de los cuales afectan directamente la carretera de cuota Tijuana-Ensenada y la infraestructura circundante. El cuarto deslizamiento, aunque no impacta directamente la carretera, es relevante por su proximidad a una ruta alterna proyectada. Los desplazamientos en estas zonas mostraron un comportamiento no lineal, con un 70 % del desplazamiento total acumulado durante 2023, año de precipitaciones abundantes durante la temporada de lluvias. Además, se identificó que las precipitaciones no solo afectan el desplazamiento inmediato, sino también su persistencia a lo largo del tiempo. Aunque la lluvia es un factor desencadenante clave, el estudio indica que existen otros factores que también influyen en la actividad de los deslizamientos, lo que requiere investigaciones adicionales para comprender completamente su comportamiento. Ambos enfoques de MT-INSAR ayudaron a identificar deslizamientos activos, pero el enfoque SBAS resultó ser más fiable para caracterizar patrones temporales y espaciales del desplazamiento, gracias a la mejor cobertura de sus resultados y su capacidad para medir patrones no lineales de desplazamiento.

Reportamos un avistamiento de un tejón americano (Taxidea taxus) nadando hacia la costa desde el Océano Pacífico cerca de El Campito, Baja California, México. El individuo emergió del oleaje y se dirigió inmediatamente tierra adentro. Este registro constituye el primer registro de un tejón americano nadando en aguas oceánicas.

The application of satellite-derived sea surface temperature in coastal regions is critical for resolving the dynamics of frontal features and coastal upwelling. Here, we examine and compare sea surface temperature (SST) gradients derived from two satellite products, the Multi-Scale Ultra-High Resolution SST Product (MUR, 0.01° grid scale) and the Operational SST and Ice Analysis (OSTIA, 0.05° grid scale), available through the Group for High Resolution SST (GHRSST). Both products show similar seasonal variability, with maxima occurring in the summer time frame. Additionally, both products show an increasing trend of SST gradients near the coast. However, differences exist between the two products (maximum gradient intensities were around 0.11 and 0.06 °C/km for OSTIA and MUR, respectively). The potential contributions of both cloud cover and the collocation of the MUR SST onto the OSTIA SST grid product to these differences were examined. Spectra and coherences were examined at two specific latitudes along the coast where upwelling can occur. A major conclusion is that future work needs to focus on cloud cover and its impact on the derivation of SST in coastal regions. Future comparisons also need to apply collocation methodologies that maintain, as much as possible, the spatial variability of the high-resolution product.