相关实验视频
Updated: Jul 5, 2025
07:28
Evolution of Staircase Structures in Diffusive Convection
Published on: September 5, 2018
6.5K
起重机在海上迁移时,在寒冷前线后面的热上流上
Sasha Pekarsky1, David Shohami1, Nir Horvitz1
1Movement Ecology Laboratory, Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Proceedings. Biological sciences
|January 17, 2024
概括
迁徙鸟类可以使用海上热翔,挑战以前的假设. 这一发现表明,选择性飞翔鸟可以利用海洋热量,影响迁徙策略.
科学领域:
- 鸟类学 鸟类学是一门学科.
- 大气科学 大气科学
- 动物迁徙 动物迁徙
背景情况:
- 据认为,在海上迁徙的陆地鸟类缺乏足够的热升空条件.
- 这导致了昂贵的飞行飞行或海上航线的绕道假设.
- 海上大气对流是海鸟利用的,但在鸟类迁移研究中基本被忽视.
研究的目的:
- 调查陆地迁徙鸟类在公海上的热升条件的存在和程度.
- 挑战关于海洋环境中鸟类迁徙的既定范式.
- 分析影响迁徙鸟类海上飞行行为的因素.
主要方法:
- 利用高分辨率的生物识别设备在四年内在跨大陆迁徙期间跟踪44只常见的起重机.
- 在中度地区,比较海上与陆地的飞行性能.
- 分析了与海上升事件相关的环境条件,特别是水空气温度差异和中度旋风.
主要成果:
- 在常见的起重机中,在公海上演示了常规的热升,这是已知的最重的法定升陆地迁徙者.
- 发现海上飞行性能与中度陆地飞行性能没有显著差异.
- 观察到秋季的海上浮动占主导地位,与中度气旋后的水空气温度差异有关.
结论:
- 这项研究挑战了基本的假设,即对于陆地迁徙者来说,海上没有热升或太弱.
- 强制翔者可能会因为热的频率低而不是缺席而避免海上穿越,他们不能用来补偿.
- 选择性飞翔鸟,包括起重机和其他潜在的鸟类,可以有效地利用海基热量进行迁徙.
相关概念视频
00:53Migration
7.9K
Migration is long-range, seasonal movement from one region or habitat to another. This common strategy, carried out by many different organisms around the world, is an adaptive response that typically corresponds to changes in an organism’s environment, like resource availability or climate. Migrations can involve huge groups of thousands of animals as well as single individuals traveling alone and can range from thousands of kilometers to just a few hundred meters.
7.9K
01:32Cytoskeletal Coordination in Cell Migration
4.8K
A migrating cell changes its shape during the cyclic events of attachment and detachment from the substratum and repositions the cell organelles correspondingly. These complex events are orchestrated by the dynamic cytoskeletal network comprising actin filaments, intermediate filaments, and microtubules. Cytoskeletal crosstalk — the direct and indirect communication between the different components — is crucial for this coordination. Direct communication involves various linker...
4.8K
01:23Coriolis Force
3.4K
An accelerating particle experiences a force equal to the mass multiplied by the acceleration in an inertial frame of reference. Consider a particle in a non-inertial frame of reference, such as a sliding ball on a rotating table. The acceleration of the ball in this rotating reference frame is different than in the intertial frame, which modifies its equation of motion. The fictitious forces acting additionally on a rotating frame of reference alter Newton's Second Law expression.
3.4K
01:54Convergent Evolution
27.7K
Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.
27.7K
01:09Cell Migration
17.0K
Cell migration, the process by which cells move from one location to another, is essential for the proper development and viability of organisms throughout their life. When cells are not able to migrate properly to their ordained locations, various disorders may occur. For example, disruption in cell migration causes chronic inflammatory diseases such as arthritis.
17.0K
01:28Irrotational Flow
462
Irrotational flow is characterized by fluid motion where particles do not rotate around their axes, resulting in zero vorticity. For a flow to be irrotational, the curl of the velocity field must be zero. This imposes specific conditions on velocity gradients. For instance, to maintain zero rotation about the z-axis, the gradient condition:
462