Spring (season)Spring, also known as springtime, is one of the four temperate seasons, succeeding winter and preceding summer. There are various technical definitions of spring, but local usage of the term varies according to local climate, cultures and customs. When it is spring in the Northern Hemisphere, it is autumn in the Southern Hemisphere and vice versa. At the spring (or vernal) equinox, days and nights are approximately twelve hours long, with daytime length increasing and nighttime length decreasing as the season progresses until the Summer Solstice in June (Northern Hemisphere) and December (Southern Hemisphere).
Urban vitalityUrban vitality is the quality of those spaces in cities that are capable of attracting heterogeneous people for different types of activities throughout varied time schedules. The areas of the city with high vitality are perceived as alive, lively or vibrant and they tend to attract people to carry out their activities, stroll or stay. However, the areas of low vitality repel people and can be perceived as unsafe.
NocturnalityNocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed senses of hearing, smell, and specially adapted eyesight. Some animals, such as cats and ferrets, have eyes that can adapt to both low-level and bright day levels of illumination (see metaturnal). Others, such as bushbabies and (some) bats, can function only at night.
Urban cultureUrban culture is the culture of towns and cities. The defining theme is the presence of a large population in a limited space that follows social norms. This makes it possible for many subcultures close to each other, exposed to social influence without necessarily intruding into the private sphere. Globally, urban areas tend to hold concentrations of power, such as government capitals and corporate headquarters, and the wealthy and powerful people that are employed in them. Cities also organize people, create norms, beliefs, and values.
Crepuscular animalIn zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal, vespertine/vespertinal, or both. This is distinguished from diurnal and nocturnal behavior, where an animal is active during the hours of daylight and of darkness, respectively. Some crepuscular animals may also be active by moonlight or during an overcast day. Matutinal animals are active only before sunrise, and vespertine only after sunset. A number of factors impact the time of day an animal is active.
