Search research articles

ACERCA DE JoVE

Visión General Liderazgo Blog Centro de Ayuda JoVE

AUTORES

Proceso de Publicación Consejo Editorial Alcance y Políticas Revisión por Pares Preguntas Frecuentes Enviar

BIBLIOTECARIOS

Testimonios Suscripciones Acceso Recursos Consejo Asesor de Bibliotecas Preguntas Frecuentes

INVESTIGACIÓN

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archivo

EDUCACIÓN

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Centro de Recursos para Profesores Sitio de Profesores

Términos y Condiciones de Uso

Política de Privacidad

Videos de Conceptos Relacionados

Population Growth

Population Growth

Population size is dynamic, increasing with birth rates and immigration, and decreasing with death rates and emigration. In ideal conditions with unlimited resources, populations can increase exponentially, which plots as a J-shaped growth rate curve of population size against time. This type of curve is characteristic of newly-introduced invasive species, or populations that have suffered catastrophic declines and are rebounding.However, realistic environmental conditions limit the number of...

Density

Density

Density is an important characteristic of substances, crucial in determining whether an object sinks or floats in a fluid. Its SI unit is kg/m3, and its cgs unit is g/cm3. The density of an object helps in identifying its composition, and also reveals information about the phase of the matter and its substructure. The densities of liquids and solids are roughly comparable, consistent with the fact that their atoms are in close contact. However, gases have much lower densities than liquids and...

Relation Between the Distributed Load and Shear

Relation Between the Distributed Load and Shear

Understanding the relationship between the distributed load and shear force in structural analysis is crucial for analyzing beams subjected to various loading conditions. Consider the case of a beam experiencing a distributed load, two concentrated loads, and a couple moment.

Pore Size Distribution

Pore Size Distribution

In concrete, the pore size distribution significantly influences the material's properties. Capillary pores, markedly larger than gel pores, form a vast network within partially hydrated cement paste, reducing the concrete's strength and increasing its permeability. This heightened permeability leads to a greater risk of damage from environmental factors like freeze-thaw cycles and chemical attacks, with the extent of vulnerability also being tied to the water-to-cement ratio.
Adequate...

Density, Specific Weight, Specific Gravity and Compressibility of Fluid

Density, Specific Weight, Specific Gravity and Compressibility of Fluid

Density, specific weight, specific gravity, and compressibility are fundamental properties of fluids. Density is the mass per unit volume, characterizing the mass of a fluid system. It influences buoyancy, pressure, flow dynamics, viscosity, thermal conductivity, and sound propagation. For instance, in pipeline design, accurate density measurements ensure that the pipeline can handle the fluid's mass.
Specific weight represents the weight per unit volume and is calculated by multiplying density...

Typical Model Studies

Typical Model Studies

Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.

También podría leer

Artículos Relacionados

Artículos vinculados a este trabajo por autores compartidos, revista y gráfico de citas.

Ordenar por

Same author

The biochemical composition and calorific content of a rotifer and its algal food: comparison of a two stage chemostat and batch culture.

Oecologia·2017

Same author

Integration of a wet analysis system on a glass chip: determination of Co(ii) as 2-nitroso-1-naphthol chelates by solvent extraction and thermal lens microscopy.

Lab on a chip·2004

Same author

Integrated multilayer flow system on a microchip.

Analytical sciences : the international journal of the Japan Society for Analytical Chemistry·2002

Same author

On-chip integration of sequential ion-sensing system based on intermittent reagent pumping and formation of two-layer flow.

Analytical chemistry·2002

Same author

Acceleration of an enzymatic reaction in a microchip.

Analytical sciences : the international journal of the Japan Society for Analytical Chemistry·2001

Same author

Photothermal temperature control of a chemical reaction on a microchip using an infrared diode laser.

Analytical chemistry·2001

Search research articles

Video Experimental Relacionado

Updated: Jul 13, 2026

Measurement of Aggregate Cohesion by Tissue Surface Tensiometry

Measurement of Aggregate Cohesion by Tissue Surface Tensiometry

Published on: April 8, 2011

Relación entre la densidad de población y el tamaño corporal en las comunidades fluviales.

P E Schmid¹, M Tokeshi, J M Schmid-Araya

¹School of Biological Sciences, Queen Mary & Westfield College, University of London, London E1 4NS, UK. p.e.schmid@qmw.ac.uk

Science (New York, N.Y.)

|September 1, 2000

Resumen

Las comunidades de animales muestran consistentemente organismos más pequeños en densidades de población más altas. Esta relación inversa entre el tamaño corporal y la densidad se observó en dos ecosistemas fluviales distintos, lo que sugiere un patrón ecológico común.

Más Videos Relacionados

Watershed Planning within a Quantitative Scenario Analysis Framework

Watershed Planning within a Quantitative Scenario Analysis Framework

Published on: July 24, 2016

Automatic Image Processing to Determine the Community Size Structure of Riverine Macroinvertebrates

Automatic Image Processing to Determine the Community Size Structure of Riverine Macroinvertebrates

Published on: January 13, 2023

Videos de Experimentos Relacionados

Last Updated: Jul 13, 2026

Measurement of Aggregate Cohesion by Tissue Surface Tensiometry

Measurement of Aggregate Cohesion by Tissue Surface Tensiometry

Published on: April 8, 2011

Watershed Planning within a Quantitative Scenario Analysis Framework

Watershed Planning within a Quantitative Scenario Analysis Framework

Published on: July 24, 2016

Automatic Image Processing to Determine the Community Size Structure of Riverine Macroinvertebrates

Automatic Image Processing to Determine the Community Size Structure of Riverine Macroinvertebrates

Published on: January 13, 2023

Área de la Ciencia:

Ecología Ecología Ecología.
Ecología comunitaria Ecología comunitaria.
Estoquiometría ecológica.

Sus antecedentes:

La relación entre la densidad de población y el tamaño corporal en las comunidades animales es un tema de debate en curso.
Los estudios anteriores se enfrentaron a desafíos debido a sesgos en los datos y inconsistencias en el manejo de los datos publicados.

Objetivo del estudio:

Investigar la relación general entre la densidad de población y el tamaño corporal en grupos de animales.
Para determinar si esta relación es consistente en diferentes sistemas ecológicos.

Principales métodos:

Utilizó conjuntos de datos completos de dos comunidades de invertebrados de corriente geográficamente distintas.
Se analizaron datos que abarcan 448 y 260 taxones de invertebrados, que cubren un amplio espectro de tamaños corporales.
Análisis estadístico aplicado para examinar la relación de escala entre la densidad y el tamaño corporal en todos los taxones.

Principales resultados:

Demostró una proporción inversa consistente entre la densidad de población y el tamaño corporal dentro de las comunidades estudiadas.
No se encontró ninguna diferencia estadísticamente significativa en la relación de escala entre los dos sistemas de arroyos geográficamente separados.
Variaciones observadas en la pendiente de regresión entre diferentes grupos taxonómicos.

Conclusiones:

La relación inversa entre la densidad de población y el tamaño corporal es una característica robusta de estas comunidades fluviales.
La convergencia en los patrones de escala sugiere un principio ecológico común en juego en estos sistemas.
Las pendientes divergentes entre los taxones indican que las reglas ecológicas o energéticas universales no rigen todas las dinámicas de la comunidad.