相关实验视频
Updated: Jun 27, 2026

05:58
An Integrated Micro-Device System for Coral Growth and Monitoring
Published on: July 21, 2023
广泛的威胁是淡水中的减少
Adam Jeziorski1, Norman D Yan, Andrew M Paterson
1Paleoecological Environmental Assessment and Research Lab, Department of Biology, Queen's University, Kingston, ON, Canada, K7L 3N6.
概括
软水北极湖正在失去,影响水生生物. 水平的下降正在导致关键的食草动物物种达夫尼亚近乎灭绝,威胁到食物网.
科学领域:
- 环境科学 环境科学
- 生态生态学 生态生态学
- 临界技术 临界技术
背景情况:
- 全球软水北极湖泊的度正在下降.
- 这些减少对水生生物群的生态后果在很大程度上未被报告.
- 关键的食草动物物种,如达芬尼亚,对水平敏感.
研究的目的:
- 研究湖水度下降对类动物浮游生物群落的影响.
- 评估加拿大盾牌湖中低条件的流行情况及其对达芬尼亚种群的潜在影响.
主要方法:
- 在湖泊沉积物中保存的甲类动物浮游生物遗骸的分析.
- 测量湖水当前的度.
- 水平与达芬尼亚存活和繁殖的已知值的比较.
主要成果:
- 记录了富含的多夫尼亚物种的近乎灭绝,与湖水度下降相关.
- 在接受调查的加拿大盾牌湖泊中,62%的度接近或低于大夫尼亚的临界值.
- 这些低水平接近已知的水平,在实验室环境中降低了达夫尼亚的生存率和生育能力.
结论:
- 环境中的损失对北极湖中的大夫尼亚种群构成重大威胁.
- 减少对水生食物网的生态影响很可能是广泛和实质性的.
- 保护工作可能需要解决淡水生态系统的耗问题.
相关概念视频
Skeleton and Calcium Homeostasis
Calcium is not only the most abundant mineral in bone but also the most abundant mineral in the human body. Calcium ions are needed for bone mineralization, tooth health, heart rate regulation and strength of contraction, blood coagulation, the contraction of smooth and skeletal muscle cells, and the regulation of nerve impulse conduction. The average calcium level in the blood is about 10 mg/dL. When the body cannot maintain this level, a person will experience hypo or hypercalcemia.
Factors Affecting Solubility
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Chȃtelier’s principle. Consider the dissolution of silver iodide:
Feedback Regulation of Calcium Concentration
Calcium is an essential signaling molecule required for various cellular functions. Calcium pumps and ion channels on cell and organellar membranes, such as those on the endoplasmic reticulum (ER), regulate calcium concentrations inside the cell. They remain closed, keeping the cytosolic calcium levels low at a resting state.
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Introduction to Electrolytes
In humans, electrolytes play a vital role in various physiological processes. Balancing electrolyte levels is essential for normal body functions; their imbalance can be life-threatening. The major electrolytes include sodium, potassium, chloride, calcium, phosphate, and bicarbonate. They are primarily involved in physiological processes, such as nerve signal transmission, membrane trafficking, muscle contraction, buffering body fluids, and balancing water levels in the body.
Role of Sodium
One...
Role of Sodium
One...
Essential Minerals for Bone Health
The minerals contained in all of the food we consume are essential for our organ systems. However, certain essential minerals, such as calcium, phosphorus, magnesium, manganese, and fluoride, largely affect bone health.
Calcium and Phosphorus
Calcium is a critical component of bones, especially in the form of calcium phosphate and calcium carbonate. Since the body cannot make calcium, it must be obtained from the diet. However, calcium cannot be absorbed from the small intestine without...
Calcium and Phosphorus
Calcium is a critical component of bones, especially in the form of calcium phosphate and calcium carbonate. Since the body cannot make calcium, it must be obtained from the diet. However, calcium cannot be absorbed from the small intestine without...
Roles of Electrolytes: Calcium and Phosphate
Calcium and phosphate are essential electrolytes in the human body, with calcium being the most abundant mineral. Around 99% of the body's calcium is stored in the skeleton and teeth, forming a crystal lattice of mineral salts in combination with phosphates. Calcium plays crucial roles in various bodily functions such as blood clotting, neurotransmitter release, muscle tone maintenance, and nervous and muscle tissue excitability.
The calcium concentration in blood plasma is primarily regulated...
The calcium concentration in blood plasma is primarily regulated...
