Results 41 to 50 of about 5,142 (164)

Estudiantes y sustancias psicoactivas

, 2022
Se exponen los resultados de un estudio epidemiológico y de percepciones sobre el consumo de drogas en la población estudiantil de pregrado de la Universidad Tecnológica de Pereira, con base en una encuesta validada a nivel Latinoamericano. Propuesta por la CICAD/OEA, que permite comparar los resultados institucionales con los de otras universidades ...
Giraldo Herrera, John Harold, Bedoya Sánchez, José Rubiel, Restrepo Mesa, Maribel   +2 more
openaire   +2 more sources

Stacked scattering: The key to bright flowers lies in the mesophyll

American Journal of Botany, Volume 113, Issue 1, January 2026.
Abstract Premise The coloration of flowers is caused by wavelength‐selective absorption by pigments and scattering of light by floral structures. Although the molecular, physiological, and chemical properties of floral pigments have been studied in considerable detail, how floral structures contribute to the visual signal remains largely unknown.
Larissa De Paola, Thomas A. Veldhuis, Marjan Kraaij, Doekele G. Stavenga, Kira J. Tiedge, Casper J. van der Kooi   +5 more
wiley   +1 more source

Weak global trade‐off between frost and drought resistance in trees

New Phytologist, Volume 249, Issue 2, Page 810-828, January 2026.
Summary Drought and frost stresses play important roles in determining species distributions, especially at range margins. Understanding how stress resistance traits interact to determine vulnerability to climate change is critical. We developed a large global database of published and new measurements of drought resistance (xylem embolism resistance ...
Maximilian Larter, Guillaume Charrier, Sylvain Delzon, William Hammond, Anne Baranger, Constance Bertrand, Nicolas Martin‐StPaul, Georges Kunstler   +7 more
wiley   +1 more source

Chemical compounds exposure and human health: advances on the politics of chemical risk control Exposición a sustancias químicas y salud humana: avances en la política de control del riesgo químico

Revista de Salud Ambiental, 2002
Advances on the politics of chemical risk control. Observed deficiencies on the management, elimination and recirculation of chemical products. Therefore, some of the main challenges for the scientific research, environmental health, nature preservation ...
Eduardo de la Peña, Ana de la Torre, Pilar Gascó   +2 more
doaj  

Efecto de la técnica de sangrado sobre la composición fenólica de vinos cv. Malbec

Revista de la Facultad de Ciencias Agrarias, 2022
El mercado actual exige, en gran parte, la disponibilidad de vinos estructurados con coloraciones intensas, razón por la cual los enólogos evalúan constantemente diversas variantes tecnológicas tendientes a satisfacer los requerimientos del ...
Martín Fanzone, Álvaro Peña-Neira, Viviana Jofré, Mariela Asso, Fernando Zamora   +4 more
doaj  

Sustancias puras y sus propiedades

TEPEXI Boletín Científico de la Escuela Superior Tepeji del Río, 2023
Una sustancia pura es aquella que tiene una composición química fija, la cual está formada por un solo elemento o también por un compuesto químico. La mezcla de varios de estos puede ser una sustancia pura siempre y cuando sea una mezcla homogénea.
Gustavo Rico-Ojeda, Jorge N. Ramos-Acevedo, Emily González-Sánchez, Héctor I. Reyes- Larios   +3 more
openaire   +1 more source

Physiological roles of lignins – tuning cell wall hygroscopy and biomechanics

New Phytologist, Volume 248, Issue 6, Page 2674-2706, December 2025.
Summary Lignins constitute the second most abundant carbon‐storing biopolymers in the biosphere. These phenolic polymers accumulate in different concentrations, compositions, and localisations within and between cell wall layers and cell types. Lignins were acquired during plant terrestrialisation 450 million years ago, and the diversification of their
Edouard Pesquet, Igor Cesarino, Shinya Kajita, Katharina Pawlowski   +3 more
wiley   +1 more source

Factores psicosociales asociados al consumo de sustancias psicoactivas en adolescentes de Pereira, Colombia

Universidad y Salud, 2020
Introducción: El consumo de sustancias psicoactivas es un problema de salud pública con alta prevalencia en los adolescentes, situación que influye en el desarrollo individual y social en la adultez.
Ángela María Álvarez–López, Natalia Jeaneth Carmona-Valencia, Ángela Liceth Pérez-Rendón, Adriana Jaramillo-Roa   +3 more
doaj   +1 more source

Trehalose 6‐phosphate – a central regulator at the crossroads of sugar signalling, metabolism, and development

New Phytologist, Volume 248, Issue 5, Page 2243-2250, December 2025.
Summary In mammals, blood sugar levels are tightly controlled by two hormones: insulin and glucagon. In flowering plants, a comparable regulatory mechanism exists, mediated by the sugar‐signalling molecule trehalose 6‐phosphate (Tre6P). Similar to insulin, Tre6P functions as a signal and negative feedback regulator of sucrose, the main transport sugar ...
Franziska Fichtner
wiley   +1 more source

Arabidopsis thaliana exhibits wide within‐species variation in tolerance to boron limitation and root and shoot trait resilience associate with a pleiotropic locus

New Phytologist, Volume 248, Issue 5, Page 2444-2465, December 2025.
Summary To improve plant tolerance to suboptimal availability of the micronutrient boron (B), it is crucial to understand the mechanisms plants have evolved to tolerate B‐limited conditions. We assessed temporal physiological, ionomic and molecular responses to B deficiency across 185 Arabidopsis thaliana accessions grown in soil‐substrate in an ...
Thomas D. Alcock, Manuela Désirée Bienert, Astrid Junker, Rhonda C. Meyer, Henning Tschiersch, Sreelekha Kudamala, Nicolaus von Wirén, Thomas Altmann, Gerd Patrick Bienert   +8 more
wiley   +1 more source