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A hydraulic telegraph (Greek: υδραυλικός τηλέγραφος) is either of two different hydraulic-telegraph telecommunication systems. The earliest one was developed in 4th-century BC Greece, while the other was developed in 19th-century AD Britain. The Greek system was deployed in combination with semaphoric fires, while the latter British system was operated purely by hydraulic fluid pressure.

Although both systems employed water in their sending and receiver devices, their transmission media were completely different. The ancient Greek system transmitted its semaphoric information to the receiver visually, which limited its use to line-of-sight distances in good visibility weather conditions only. The 19th-century British system used water-filled pipes to effect changes to the water level in the receiver unit (similar to a transparent water-filled flexible tube used as a level indicator), thus limiting its range to the hydraulic pressure that could be generated at the transmitter's device.

While the Greek device was extremely limited in the codes (and hence the information) it could convey, the British device was never deployed in operation other than for very short-distance demonstrations. Although the British device could be used in any visibility within its range of operation, it could not work in sub-zero temperatures without additional infrastructure to heat the pipes. This contributed to its impracticality.

🔗 Aviation 🔗 Marketing & Advertising 🔗 United Kingdom 🔗 Guild of Copy Editors 🔗 Retailing 🔗 Home Living

The Hoover free flights promotion was a marketing promotion run by the British division of the Hoover Company in late 1992. The promotion, aiming to boost sales during the global recession of the early 1990s, offered two complimentary round-trip plane tickets to the United States, worth about £600, to any customer purchasing at least £100 in Hoover products. Hoover had been experiencing dwindling sales as a result of the economic downturn and a sharp increase in competing brands. Hoover was counting on most customers spending more than £100, as well as being deterred from completing the difficult application process, and not meeting its exact terms.

Consumer response was much higher than the company anticipated, with many customers buying the minimum £100 of Hoover products to qualify. It was perceived as two US flights for just £100 with a free vacuum cleaner included. The resulting demand was disastrous for the 84-year-old company. Hoover cancelled the ticket promotion after consumers had already bought the products and filled in forms applying for millions of pounds' worth of tickets. Reneging on the offer resulted in protests and legal action from customers who failed to receive the tickets they had been promised. The campaign was a financial disaster for the company and led to the loss of Hoover's Royal Warrant after the airing of a 2004 BBC documentary. The European branch of the company was eventually sold to one of its competitors, Candy, having never recovered from the losses, the promotion and the subsequent scandal.

🔗 Mammals

Musth or must (an Urdu word, from Persian, lit. drunk) is a periodic condition in bull (male) elephants characterized by highly aggressive behavior and accompanied by a large rise in reproductive hormones.

Testosterone levels in an elephant in musth can be on average 60 times greater than in the same elephant at other times (in specific individuals these testosterone levels can even reach as much as 140 times the normal). However, whether this hormonal surge is the sole cause of musth, or merely a contributing factor, is unknown.

Scientific investigation of musth is problematic because even the most placid elephants become highly violent toward humans and other elephants during musth.

🔗 Transport 🔗 Transport/Maritime 🔗 Lighthouses

A light characteristic is all of the properties that make a particular navigational light identifiable. Graphical and textual descriptions of navigational light sequences and colours are displayed on nautical charts and in Light Lists with the chart symbol for a lighthouse, lightvessel, buoy or sea mark with a light on it. Different lights use different colours, frequencies and light patterns, so mariners can identify which light they are seeing.

🔗 Astronomy

A Messier marathon is an attempt, usually organized by amateur astronomers, to find as many Messier objects as possible during one night. The Messier catalogue was compiled by French astronomer Charles Messier during the late 18th century and consists of 110 relatively bright deep-sky objects (galaxies, nebulae, and star clusters).

🔗 Biology 🔗 Astronomy 🔗 Color 🔗 Evolutionary biology

The Purple Earth Hypothesis (PEH) is an astrobiological hypothesis, first proposed by molecular biologist Shiladitya DasSarma in 2007, that the earliest photosynthetic life forms of Early Earth were based on the simpler molecule retinal rather than the more complex porphyrin-based chlorophyll, making the surface biosphere appear purplish rather than its current greenish color. It is estimated to have occurred between 3.5 and 2.4 billion years ago during the Archean eon, prior to the Great Oxygenation Event and Huronian glaciation.

Retinal-containing cell membranes exhibit a single light absorption peak centered in the energy-rich green-yellow region of the visible spectrum, but transmit and reflect red and blue light, resulting in a magenta color. Chlorophyll pigments, in contrast, absorb red and blue light, but little or no green light, which results in the characteristic green reflection of plants, green algae, cyanobacteria and other organisms with chlorophyllic organelles. The simplicity of retinal pigments in comparison to the more complex chlorophyll, their association with isoprenoid lipids in the cell membrane, as well as the discovery of archaeal membrane components in ancient sediments on the Early Earth are consistent with an early appearance of life forms with purple membranes prior to the turquoise of the Canfield ocean and later green photosynthetic organisms.

🔗 Poetry 🔗 Bible

An acrostic is a poem (or other form of writing) in which the first letter (or syllable, or word) of each line (or paragraph, or other recurring feature in the text) spells out a word, message or the alphabet. The word comes from the French acrostiche from post-classical Latin acrostichis, from Koine Greek ἀκροστιχίς, from Ancient Greek ἄκρος "highest, topmost" and στίχος "verse". As a form of constrained writing, an acrostic can be used as a mnemonic device to aid memory retrieval.

Relatively simple acrostics may merely spell out the letters of the alphabet in order; such an acrostic may be called an 'alphabetical acrostic' or abecedarius. These acrostics occur in the first four of the five chapters that make up the Book of Lamentations, in the praise of the good wife in Proverbs 31:10-31, and in Psalms 25, 34, 37, 111, 112, 119 and 145 of the Hebrew Bible. Notable among the acrostic Psalms is the long Psalm 119, which typically is printed in subsections named after the 22 letters of the Hebrew alphabet, each section consisting of 8 verses, each of which begins with the same letter of the alphabet and the entire psalm consisting of 22 x 8 = 176 verses; and Psalm 145, which is recited three times a day in the Jewish services. Some acrostic psalms are technically imperfect. E.g. Psalm 9 and Psalm 10 appear to constitute a single acrostic psalm together, but the length assigned to each letter is unequal and five of the 22 letters of the Hebrew alphabet are not represented and the sequence of two letters is reversed. In Psalm 25 one Hebrew letter is not represented, the following letter (Resh) repeated. In Psalm 34 the current final verse, 23, does fit verse 22 in content, but adds an additional line to the poem. In Psalms 37 and 111 the numbering of verses and the division into lines are interfering with each other; as a result in Psalm 37, for the letters Daleth and Kaph there is only one verse, and the letter Ayin is not represented. Psalm 111 and 112 have 22 lines, but 10 verses. Psalm 145 does not represent the letter Nun, having 21 one verses, but one Qumran manuscript of this Psalm does have that missing line, which agrees with the Septuagint.

Acrostics are common in medieval literature, where they usually serve to highlight the name of the poet or his patron, or to make a prayer to a saint. They are most frequent in verse works but can also appear in prose. The Middle High German poet Rudolf von Ems for example opens all his great works with an acrostic of his name, and his world chronicle marks the beginning of each age with an acrostic of the key figure (Moses, David, etc.). In chronicles, acrostics are common in German and English but rare in other languages.

Often the ease of detectability of an acrostic can depend on the intention of its creator. In some cases an author may desire an acrostic to have a better chance of being perceived by an observant reader, such as the acrostic contained in the Hypnerotomachia Poliphili (where the key capital letters are decorated with ornate embellishments). However, acrostics may also be used as a form of steganography, where the author seeks to conceal the message rather than proclaim it. This might be achieved by making the key letters uniform in appearance with the surrounding text, or by aligning the words in such a way that the relationship between the key letters is less obvious. This is referred to as null ciphers in steganography, using the first letter of each word to form a hidden message in an otherwise innocuous text. Using letters to hide a message, as in acrostic ciphers, was popular during the Renaissance, and could employ various methods of enciphering, such as selecting other letters than initials based on a repeating pattern (equidistant letter sequences), or even concealing the message by starting at the end of the text and working backwards.

🔗 Food and drink 🔗 Trains 🔗 Finland 🔗 Trains/Streetcars 🔗 Food and drink/Pubs

SpåraKoff is a HM V type tram converted into a mobile bar in Helsinki, Finland. Known as the pub tram, the vehicle does circular tours of downtown Helsinki picking up passengers for a fee during summer months. It is operated jointly by Sinebrychoff, HOK-Elanto (part of the S Group), and Helsinki City Transport.

The pub tram is immediately distinguishable in the Helsinki traffic by its vivid red colour (as opposed to the normal colours, green and cream, used on the Helsinki tram network of the Helsinki City Transport), and by the destination board that reads "PUB".

It is one of the four HM V trams that remain operational in Helsinki. Two of them are museum trams, and one is used as a non-passenger carrying advertisement tram.

🔗 Science Fiction 🔗 Plants

A Dyson tree is a hypothetical genetically engineered plant (perhaps resembling a tree) capable of growing inside a comet, suggested by the physicist Freeman Dyson. Plants could produce a breathable atmosphere within hollow spaces in the comet (or even within the plants themselves), utilising solar energy for photosynthesis and cometary materials for nutrients, thus providing self-sustaining habitats for humanity in the outer solar system analogous to a greenhouse in space or a shell grown by a mollusc.

A Dyson tree might consist of a few main trunk structures growing out from a comet nucleus, branching into limbs and foliage that intertwine, forming a spherical structure possibly dozens of kilometers across.

🔗 Science 🔗 Academic Journals

FUTON bias (acronym for "full text on the Net") is a tendency of scholars to cite academic journals with open access—that is, journals that make their full text available on the Internet without charge—in preference to toll-access publications. Scholars in some fields can more easily discover and access articles whose full text is available online, which increases authors' likelihood of reading and citing these articles, an issue that was first raised and has been mainly studied in connection with medical research. In the context of evidence-based medicine, articles in expensive journals that do not provide open access (OA) may be "priced out of evidence", giving a greater weight to FUTON publications. FUTON bias may increase the impact factor of open-access journals relative to journals without open access.

One study concluded that authors in medical fields "concentrate on research published in journals that are available as full text on the internet, and ignore relevant studies that are not available in full text, thus introducing an element of bias into their search result". Authors of another study conclude that "the OA advantage is a quality advantage, rather than a quality bias", that authors make a "self-selection toward using and citing the more citable articles—once OA self-archiving has made them accessible", and that open access "itself will not make an unusable (hence uncitable) paper more used and cited".

The related no abstract available bias is a scholar's tendency to cite journal articles that have an abstract available online more readily than articles that do not—this affects articles' citation count similarly to FUTON bias.