Tens of thousands of drone (无人机)owners will have to register their devices for the first time under regulations designed to safeguard privacy.

Rules introduced yesterday require all drones that are fitted with cameras to be logged with the Civil Aviation Authority (CAA). Anyone who fails to do so faces being taken to court and fined up to £1,000. Drones heavier than 250g already have to be registered with the CAA, which costs £9 and must be renewed annually, but the new measures extend this requirement to all devices, including the lightweight models that are used by hobbyist pilots.

The move comes after sharp rise in the number of drones bought by enthusiasts or those operating them for commercial reasons, such as to inspect infrastructure or for photography and filming.

However, the rise has prompted concerns over privacy, with fears that drones are being used to spy on private residences and other buildings. It has also led to an increase in the number of near-misses between drones and other aircraft, including commercial passenger jets. The latest figures show 531 near-misses involving drones were logged in the past decade, including 125 recorded in 2019.

By law drones are supposed to be operated within an operator's line of sight. They have to remain below an altitude of 400ft to avoid interfering with aircraft and flown at least 164ft away from people and buildings. The government has already toughened up regulations in recent years. This includes requiring all operators to pass an online test before being allowed to fly devices. Other changes to the regulations include allowing drones that weigh up to 25kg to be operated, compared with a previous limit of 20kg.

Devices will also fall into three new categories of risk --high, medium and low -- depending on how they will be flown. Low-risk drones, including those typically used by hobbyists, will have operational limitations but will not need authorisation （授权）for flights. Authorisation is needed for larger medium-risk and high-risk drone flights, which are typically carried out in more complex environments, including those beyond the operator's line of sight, which is banned under normal circumstances.

Christian Struwe, the director of public policy, said of the new regulation: "It simplifies different processes and allows customers to travel from country to country without having to worry about different rules in different foreign locations"

A recent study conducted by the Massachusetts Institute of Technology（MIT）has discovered that river erosion（侵蚀）can lead to increased biodiversity in areas with minimal tectonic（地壳构造的）activity. The researchers focused their attention on the Tennessee River Basin and examined how the erosion of various rock types by the river had led to the separation and diversification of a type of fish called the greenfin darter. As time passed, these separate fish populations evolved into distinct families with genetic differences.

Scientist Thomas Near observed that the greenfin darter was exclusively found in the southern half of the Tennessee River Basin. The researchers analyzed the genes of each fish in Near's data set and constructed an evolutionary tree. This tree helped them comprehend the evolution and differences of the greenfin darter species. They discovered that the fish within the same branch of the river were more closely related to each other than to the fish in other branches.

This study provides evidence that river erosion significantly impacts biodiversity in regions with low tectonic activity. It illustrates how changes in the landscape caused by river erosion can lead to the division and diversification of species over time, even in peaceful environments. These findings enhance our understanding of the mechanisms（机制）that drive biodiversity and evolution, even in areas that are not typically associated with intense tectonic activity.

Subsequently, the team discovered a strong correlation between the habitats of the greenfin darter and the type of rocks present. The southern half of the Tennessee River Basin consists of hard, tightly packed rocks, resulting in turbulent（湍急的）waves in the rivers that flow through it. This characteristic may be favored by the greenfin darter. As a result, the team assumed whether the distribution of greenfin darter habitats had been influenced by the changing rock types, as the rivers eroded the land over time. To test this assumption, the researchers developed a simulation model. Remarkably, the results confirmed their assumption.

Lighting is a key design feature in your home and deserves consideration, whether it's to brighten up a dull corner or you're planning a full renovation （翻新）. Here, we put the spotlight on four key lighting design layers and how you can use them to capture every room of your home in its best light. 

General lighting

Think of general lighting as the background layer that casts an even illumination （照明） throughout a room, most commonly from your ceiling lights. As these are often the main source of light for a room, it's wise to have flexible options depending on the time of day, or desired brightness to suit the mood and the room's purpose at the time. 

Ambient（氛围的） lighting

Ambient lighting is the layer that adds warmth and softness to your space. Think lamp belt under the kitchen bench, or floor lamps in the corner. Use ambient lighting where you want to encourage rest and comfort， such as living spaces and bedrooms. 

Task lighting

The next layer to consider is task lighting for more practical uses. These are brighter and are designed to illuminate workplaces, and are also used for study areas, home offices,, bedside tables and reading corners. 

Accentlighting

Accent lighting is placed to create a specific light effect， such as downlights or spotlights to highlight artwork， and wash lights against walls. The layering of accent lighting can be used to highlight architectural details and is an artful way to create focus and play with light in your space.