To stay up to date you can also follow on Mastodon.

🔗 Architecture 🔗 Japan 🔗 Japan/Tokyo

The X-Seed 4000 is a visionary skyscraper for what would be, if it was built, the tallest building in the world. The idea was initially created and developed by Peter Neville. Its proposed 4-kilometre (2.5 mi) height, 6-kilometre-wide (3.7 mi) sea-base, and 800-floor capacity could accommodate 500,000 to 1,000,000 inhabitants. This structure would be composed of over 3,000,000 tons of pure steel.

It was designed for Tokyo, Japan by the Taisei Corporation in 1995 as a futuristic environment combining ultra-modern living and interaction with nature. Methods of transportation within the X-seed would most likely include MagLev trains.

The X-Seed 4000 "is never meant to be built," says Georges Binder, managing director of Buildings & Data, a firm which compiles data banks on buildings worldwide. "The purpose of the plan was to earn some recognition for the firm, and it worked."

Unlike conventional skyscrapers, to remain habitable the (X-Seed 4000) would be forced to actively protect its occupants from considerable internal air pressure and external air pressure gradations and weather fluctuations that its massive elevation would cause. Its design calls for the use of solar power to maintain internal environmental conditions. As the proposed site for the structure is located in the Pacific Ring of Fire, the most active volcano range in the world, the X-Seed 4000 would be subject to earthquakes and tsunamis.

A sea-based location and a Mount Fuji shape are some of this building's other major design features—the real Mount Fuji is land-based and is 3,776 metres (12,388 ft) high so is 224 metres (735 ft) shorter than the X-Seed 4000.

The X-Seed 4000 is projected to be twice the height of the Shimizu Mega-City Pyramid at 2,004 metres (6,575 ft). The Shimizu Mega-City Pyramid (proposed in 2007, also planned for Tokyo, Japan) faces most of the same problems as the X-Seed. Other projects that may be in the top five man made structures are the Ultima Tower 3,218 metres (10,558 ft) in San Francisco, Dubai City Tower 2,400 metres (7,900 ft) and the Bionic Tower 1,228 metres (4,029 ft) in either Hong Kong or Shanghai.

🔗 Computing 🔗 Mathematics 🔗 Crime 🔗 Cryptography 🔗 Cryptography/Computer science

An illegal prime is a prime number that represents information whose possession or distribution is forbidden in some legal jurisdictions. One of the first illegal primes was found in 2001. When interpreted in a particular way, it describes a computer program that bypasses the digital rights management scheme used on DVDs. Distribution of such a program in the United States is illegal under the Digital Millennium Copyright Act. An illegal prime is a kind of illegal number.

🔗 Economics 🔗 Business

The principal–agent problem, in political science, supply chain management and economics (also known as agency dilemma or the agency problem) occurs when one person or entity (the "agent"), is able to make decisions and/or take actions on behalf of, or that impact, another person or entity: the "principal". This dilemma exists in circumstances where agents are motivated to act in their own best interests, which are contrary to those of their principals, and is an example of moral hazard. Issues also arise when companies have an incentive to become increasingly deferential to management that have ownership stakes. As shareholders are dis-incentived to intervene, there are fewer checks on management. Issues can also arise among different types of management.

Common examples of this relationship include corporate management (agent) and shareholders (principal), elected officials (agent) and citizens (principal), or brokers (agent) and markets (buyers and sellers, principals). Consider a legal client (the principal) wondering whether their lawyer (the agent) is recommending protracted legal proceedings because it is truly necessary for the client's well-being, or because it will generate income for the lawyer. In fact the problem can arise in almost any context where one party is being paid by another to do something where the agent has a small or nonexistent share in the outcome, whether in formal employment or a negotiated deal such as paying for household jobs or car repairs.

The principal–agent problem typically arises where the two parties have different interests and asymmetric information (the agent having more information), such that the principal cannot directly ensure that the agent is always acting in their (the principal's) best interest, particularly when activities that are useful to the principal are costly to the agent, and where elements of what the agent does are costly for the principal to observe (see moral hazard and conflict of interest). Often, the principal may be sufficiently concerned at the possibility of being exploited by the agent that they choose not to enter into the transaction at all, when it would have been mutually beneficial: a suboptimal outcome that can lower welfare overall. The deviation from the principal's interest by the agent is called "agency costs".

The agency problem can be intensified when an agent acts on behalf of multiple principals (see multiple principal problem). When one agent acts on behalf of multiple principals, the multiple principals have to agree on the agent's objectives, but face a collective action problem in governance, as individual principals may lobby the agent or otherwise act in their individual interests rather than in the collective interest of all principals. As a result, there may be free-riding in steering and monitoring, duplicate steering and monitoring, or conflict between principals, all leading to high autonomy for the agent. The multiple principal problem is particularly serious in the public sector, where multiple principals are common and both efficiency and democratic accountability are undermined in the absence of salient governance. This problem may occur, for example, in the governance of the executive power, ministries, agencies, intermunicipal cooperation, public-private partnerships, and firms with multiple shareholders.

The relationships between investment managers and corporate management is an especially common example of the principal–agent relationship. There are several drivers of agency problems that affect investment managers of index funds and mutual funds include. First, investment managers receive a fraction of the benefits resulting from stewardship activities while having to handle all the costs. competition among investment managers is can also contribute to agency problems.And, lastly, another driver of agency problems is that investment managers can be heavily influenced by private incentives provided by the managers of corporations.

Various mechanisms may be used to align the interests of the agent with those of the principal. In employment, employers (principal) may use piece rates/commissions, profit sharing, efficiency wages, performance measurement (including financial statements), the agent posting a bond, or the threat of termination of employment to align worker interests with their own.

🔗 Germany 🔗 Measurement

The obsolete units of measurement of German-speaking countries consist of a variety of units, with varying local standard definitions. Some of these units are still used in everyday speech and even in stores and on street markets as shorthand for similar amounts in the metric system. For example, some customers ask for one pound (ein Pfund) of something when they want 500 grams.

The metric system became compulsory on 1 January 1872, in Germany and on 1 January 1876, in Austria.

Some obsolete German units have names similar to units that were traditionally used in other countries, and that are still used in the United Kingdom (imperial units) and the United States (United States customary units).

🔗 Mathematics 🔗 Archaeology

The Ishango bone is a bone tool and possible mathematical object, dated to the Upper Paleolithic era. It is a dark brown length of bone, the fibula of a baboon, with a sharp piece of quartz affixed to one end, perhaps for engraving. It is thought by some to be a tally stick, as it has a series of what has been interpreted as tally marks carved in three columns running the length of the tool, though it has also been suggested that the scratches might have been to create a better grip on the handle or for some other non-mathematical reason. Others argue that the marks on the object are non-random and that it was likely a kind of counting tool and used to perform simple mathematical procedures.

🔗 Computer Security 🔗 Computer Security/Computing

Zombie Zero is an attack vector where a cyber attacker utilized malware that was clandestinely embedded in new barcode readers which were manufactured overseas.

It remains unknown if this attack was promulgated by organized crime or a nation state. Clearly there was significant planning and investment in order to design the malware, and then embed it into the hardware within the barcode scanner. Internet of things (IoT) devices may be similarly preinstalled with malware that can capture the network passwords and then open a backdoor to attackers. Given the high volume of these devices manufactured overseas high caution is to be exercised before placing these devices on corporate or government networks.

🔗 Food and drink 🔗 Plants 🔗 Alternative medicine 🔗 Women's Health

Silphium (also known as silphion, laserwort, or laser) was a plant that was used in classical antiquity as a seasoning, perfume, as an aphrodisiac, or as a medicine. It also was used as a contraceptive by ancient Greeks and Romans. It was the essential item of trade from the ancient North African city of Cyrene, and was so critical to the Cyrenian economy that most of their coins bore a picture of the plant. The valuable product was the plant's resin (laser, laserpicium, or lasarpicium).

Silphium was an important species in prehistory, as evidenced by the Egyptians and Knossos Minoans developing a specific glyph to represent the silphium plant. It was used widely by most ancient Mediterranean cultures; the Romans who mentioned the plant in poems or songs, considered it "worth its weight in denarii" (silver coins), or even gold. Legend said that it was a gift from the god Apollo.

The exact identity of silphium is unclear. It is commonly believed to be a now-extinct plant of the genus Ferula, perhaps a variety of "giant fennel". The still-extant plants Margotia gummifera and Ferula tingitana have been suggested as other possibilities. Another plant, asafoetida, was used as a cheaper substitute for silphium, and had similar enough qualities that Romans, including the geographer Strabo, used the same word to describe both.

🔗 Computing 🔗 Books

EPUB is an e-book file format that uses the ".epub" file extension. The term is short for electronic publication and is sometimes styled ePub. EPUB is supported by many e-readers, and compatible software is available for most smartphones, tablets, and computers. EPUB is a technical standard published by the International Digital Publishing Forum (IDPF). It became an official standard of the IDPF in September 2007, superseding the older Open eBook standard.

The Book Industry Study Group endorses EPUB 3 as the format of choice for packaging content and has stated that the global book publishing industry should rally around a single standard. The EPUB format is implemented as an archive file consisting of XHTML files carrying the content, along with images and other supporting files. EPUB is the most widely supported vendor-independent XML-based (as opposed to PDF) e-book format; that is, it is supported by almost all hardware readers, except for Kindle.

🔗 Medicine 🔗 Medicine/Pulmonology 🔗 Physiology 🔗 Scuba diving 🔗 Physiology/respiratory

Liquid breathing is a form of respiration in which a normally air-breathing organism breathes an oxygen-rich liquid (such as a perfluorocarbon), rather than breathing air.

This requires certain physical properties such as respiratory gas solubility, density, viscosity, vapor pressure, and lipid solubility which some, but not all, perfluorochemicals (perfluorocarbon) have. Thus, it is critical to choose the appropriate PFC for a specific biomedical application, such as liquid ventilation, drug delivery or blood substitutes. The physical properties of PFC liquids vary substantially; however, the one common property is their high solubility for respiratory gases. In fact, these liquids carry more oxygen and carbon dioxide than blood.

In theory, liquid breathing could assist in the treatment of patients with severe pulmonary or cardiac trauma, especially in pediatric cases. Liquid breathing has also been proposed for use in deep diving and space travel. Despite some recent advances in liquid ventilation, a standard mode of application has not yet been established.

🔗 Internet 🔗 Cryptography 🔗 Cryptography/Computer science

k-anonymity is a property possessed by certain anonymized data. The concept of k-anonymity was first introduced by Latanya Sweeney and Pierangela Samarati in a paper published in 1998 as an attempt to solve the problem: "Given person-specific field-structured data, produce a release of the data with scientific guarantees that the individuals who are the subjects of the data cannot be re-identified while the data remain practically useful." A release of data is said to have the k-anonymity property if the information for each person contained in the release cannot be distinguished from at least ${\displaystyle k-1}$ individuals whose information also appear in the release.

K-anonymity received widespread media coverage in 2018 when British computer scientist Junade Ali used the property alongside cryptographic hashing to create a communication protocol to anonymously verify if a password was leaked without disclosing the searched password. This protocol was implemented as a public API in Troy Hunt's Have I Been Pwned? service and is consumed by multiple services including password managers and browser extensions. This approach was later replicated by Google's Password Checkup feature.