Great White Shark

The great white shark (Carcharodon carcharias), also known as the white shark, white pointer, or simply great white, is a species of large mackerel shark which can be found in the coastal surface waters of all the major oceans. It is the only known surviving species of its genus Carcharodon. The great white shark is notable for its size, with the largest preserved female specimen measuring 5.83 m (19.1 ft) in length and around 2,000 kg (4,410 lb) in weight at maturity.[3] However, most are smaller; males measure 3.4 to 4.0 m (11 to 13 ft), and females measure 4.6 to 4.9 m (15 to 16 ft) on average.[4][5] According to a 2014 study, the lifespan of great white sharks is estimated to be as long as 70 years or more, well above previous estimates,[6] making it one of the longest lived cartilaginous fishes currently known.[7] According to the same study, male great white sharks take 26 years to reach sexual maturity, while the females take 33 years to be ready to produce offspring.[8] Great white sharks can swim at speeds of 25 km/h (16 mph)[9] for short bursts and to depths of 1,200 m (3,900 ft).[10]

The great white shark is arguably the world’s largest-known extant macropredatory fish, and is one of the primary predators of marine mammals, such as pinnipeds and dolphins. The great white shark is also known to prey upon a variety of other animals, including fish, other sharks, and seabirds. It has only one recorded natural predator, the orca.[11]

The species faces numerous ecological challenges which has resulted in international protection. The International Union for Conservation of Nature lists the great white shark as a vulnerable species,[1] and it is included in Appendix II of CITES.[12] It is also protected by several national governments, such as Australia (as of 2018).[13] Due to their need to travel long distances for seasonal migration and extremely demanding diet, it is not logistically feasible to keep great white sharks in captivity; because of this, while attempts have been made to do so in the past, there are no known aquariums in the world believed to house a live specimen.[14]

The great white shark is depicted in popular culture as a ferocious man-eater, largely as a result of the novel Jaws by Peter Benchley and its subsequent film adaptation by Steven Spielberg. Humans are not a preferred prey,[15] but nevertheless it is responsible for the largest number of reported and identified fatal unprovoked shark attacks on humans.[16] However, attacks are rare, typically occurring fewer than 10 times per year globally.[17][18]

Bitcoin

Bitcoin (abbreviation: BTC;[a] sign: ₿) is the first decentralized cryptocurrency. Nodes in the peer-to-peer bitcoin network verify transactions through cryptography and record them in a public distributed ledger, called a blockchain, without central oversight. Consensus between nodes is achieved using a computationally intensive process based on proof of work, called mining, that guarantees the security of the bitcoin blockchain. Mining consumes increasing quantities of electricity and has been criticized for its environmental effects.[5]

Bitcoin
Prevailing bitcoin logo
Logo
Denominations
Plural
Bitcoins
Symbol

(Unicode: U+20BF ₿ BITCOIN SIGN)[1] Code
BTC[a] Precision
10−8
Subunits
 1⁄1000
Millibitcoin
 1⁄1000000
Microbitcoin
 1⁄100000000
Satoshi[b][2] Development
Original author(s)
Satoshi Nakamoto
White paper
“Bitcoin: A Peer-to-Peer Electronic Cash System”
Implementation(s)
Bitcoin Core
Initial release
0.1.0 / 9 January 2009 (15 years ago)
Latest release
25.1 / 19 October 2023 (6 months ago)[3] Code repository
github.com/bitcoin/bitcoin
Development status
Active
Written in
C++
Source model
Free and open-source software
License
MIT License
Ledger
Ledger start
3 January 2009 (15 years ago)
Timestamping scheme
Proof of work (partial hash inversion)
Hash function
SHA-256 (two rounds)
Issuance schedule
Decentralized (block reward)
Initially ₿50 per block, halved every 210,000 blocks
Block reward
₿3.125 (as of 2024)
Block time
10 minutes
Circulating supply
₿19,591,231 (as of 6 January 2024)
Supply limit
₿21,000,000[c] Valuation
Exchange rate
Floating
Demographics
Official user(s)
El Salvador[4] This article contains special characters. Without proper rendering support, you may see question marks, boxes, or other symbols.
Based on a free market ideology, bitcoin was invented in 2008 by Satoshi Nakamoto, an unknown person.[6] Use of bitcoin as a currency began in 2009,[7] with the release of its open-source implementation.[8]: ch. 1  In 2021, El Salvador adopted it as legal tender.[4] Bitcoin is currently used more as a store of value and less as a medium of exchange or unit of account. It is mostly seen as an investment and has been described by many scholars as an economic bubble.[9] As bitcoin is pseudonymous, its use by criminals has attracted the attention of regulators, leading to its ban by several countries as of 2021.[10]

Tooth

The tooth (plural teeth), Latin and technical term Dens (plural Dentes), is a hard structure in the oral cavity of vertebrates. The teeth are used to grasp, crush and grind food. They have developed in vertebrates according to the form-function principle. In humans, other functions include sound production (especially dental sounds) and social functions.

Design science (methodology)

Design science research (DSR) is a research paradigm focusing on the development and validation of prescriptive knowledge in information science. Herbert Simon distinguished the natural sciences, concerned with explaining how things are, from design sciences which are concerned with how things ought to be,[1] that is, with devising artifacts to attain goals. further explanation needed] Design science research methodology (DSRM) refers to the research methodologies associated with this paradigm. It spans the methodologies of several research disciplines, for example information technology, which offers specific guidelines for evaluation and iteration within research projects.

DSR focuses on the development and performance of (designed) artifacts with the explicit intention of improving the functional performance of the artifact. DSRM is typically applied to categories of artifacts including algorithms, human/computer interfaces, design methodologies (including process models) and languages. Its application is most notable in the Engineering and Computer Science disciplines, though is not restricted to these and can be found in many disciplines and fields. DSR, or constructive research, in contrast to explanatory science research, has academic research objectives generally of a more pragmatic nature. Research in these disciplines can be seen as a quest for understanding and improving human performance. Such renowned research institutions as the MIT Media Lab, Stanford University’s Center for Design Research, Carnegie Mellon University’s Software Engineering Institute, Xerox’s PARC, and Brunel University London’s Organisation and System Design Centre, use the DSR approach.

Design science is a valid research methodology to develop solutions for practical engineering problems. Design science is particularly suitable for wicked problems.

Apples

Apple_JE3_BE3.webp

An apple is a round, edible fruit produced by an apple tree (Malus spp., among them the domestic or orchard apple; Malus domestica). Apple trees are cultivated worldwide and are the most widely grown species in the genus Malus. The tree originated in Central Asia, where its wild ancestor, Malus sieversii, is still found. Apples have been grown for thousands of years in Asia and Europe and were introduced to North America by European colonists. Apples have religious and mythological significance in many cultures, including Norse, Greek, and European Christian tradition.

Apples grown from seed tend to be very different from those of their parents, and the resultant fruit frequently lacks desired characteristics. For commercial purposes, including botanical evaluation, apple cultivars are propagated by clonal grafting onto rootstocks. Apple trees grown without rootstocks tend to be larger and much slower to fruit after planting. Rootstocks are used to control the speed of growth and the size of the resulting tree, allowing for easier harvesting.

There are more than 7,500 cultivars of apples.[3] Different cultivars are bred for various tastes and uses, including cooking, eating raw, and cider or apple juice production. Trees and fruit are prone to fungal, bacterial, and pest problems, which can be controlled by a number of organic and non-organic means. In 2010, the fruit’s genome was sequenced as part of research on disease control and selective breeding in apple production.

Worldwide production of apples in 2021 was 93 million tonnes, with China accounting for nearly half of the total.[4]