#acta

• Anticategory — An abstract concept utilized in structural logic or mathematical category theory to denote a dual, inverse, or complementary structure in relation to a standard defined category. In a philosophical sense, it represents a conceptual class constructed through direct opposition or by negating the fundamental attributes of an established ontological category.
• Anti-realist — Belonging to anti-realism, denying the postulates of realism, or refusing the faithful and objective representation of reality. As a noun, it denotes the philosopher arguing that truth depends on our cognitive systems, or the artist/writer whose works use non-mimetic, abstract, or fantastic techniques to construct an alternative universe detached from the canons of classical realism.
• Cataract — A popular or archaic name for cataract, an ophthalmological condition manifested by the partial or total opacification of the lens in humans or animals, causing gradual vision loss; in empirical veterinary medicine, the term also describes a weak lead-based disinfectant aqueous solution used externally for washing wounds, inflammations, or skin ulcers.
• Compacted — Having been tightly squeezed, pressed, rammed, or forcefully packed together; a material, soil, or object that has reduced its volume following the compacting process, becoming dense, solid, or tightly fixed in bonds.
• Aporocactus — A genus of epiphytic or lithophytic plants in the family Cactaceae, native to the mountainous regions and forests of Mexico, characterized by long, slender, cylindrical, and creeping or pendulous stems covered with fine spines and large, tubular, brightly colored pink, red, or crimson flowers. In modern horticulture, the most famous species is Aporocactus flagelliformis (rat-tail cactus), widely cultivated in hanging baskets.
• Areola — A small circular area, pigmented or structurally differentiated, surrounding a central point, such as the darker ring of skin around the nipple or the space bounded by the secondary vein ramifications of a leaf. In botany, the term also denotes the microscopic structure or cushion of hairs or spines specific to cacti (Cactaceae family), from which flowers, new branches, or defensive needles develop.
• Argillolite — A consolidated argillaceous sedimentary rock, structurally formed through the cementation, compaction, and deep dehydration of fine pelitic deposits (clay muds); a fine argillaceous sandstone or mudstone rock. In a geological sense, argilolitul is characterized by a massive texture, compact mass, and the absence of obvious fissility, representing a stable lithostratigraphic unit used in sedimentary basin analysis.
• Arial — An extremely widespread typeface (font) characterized by its sans-serif, neo-grotesque structural design, created in 1982 for digital screens and printed documents; it offers excellent legibility due to its clean, uniform lines and balanced proportions, becoming a global industrial standard across operating systems and office suites.
• Ariocarpus — A genus of cacti endemic to the semi-desert zones of Mexico and southern Texas, characterized by extremely slow growth, flattened globular stems, and unique, triangular or rocky tubercles lacking classic spines at maturity; these succulent plants have a massive taproot used as a water reservoir and are highly prized by collectors for their large flowers and mimetic appearance mimicking surrounding limestones.
• Ariocarpus retusus — A cactus species endemic to the arid and semi-desert regions of Mexico (genus Ariocarpus), characterized by the absence of spines in adult specimens and the presence of robust, triangular, grayish-green tubercles, often retuse or rounded at the apex. Commonly known as 'living rock', this globose cactus is extremely slow-growing and features a massive taproot, being bio-structurally adapted to survive within the cracks of limestone rocks.
• Arp — A German surname, famous in art history due to Jean Arp (Hans Arp), a French-German sculptor, painter, and poet, co-founder of the Dada movement in Zürich in 1916. In astronomy, it refers to Halton Arp and his 'Atlas of Peculiar Galaxies'.
• Arrojadoa — A genus of xerophytic plants within the Cactaceae family, endemic to the semi-arid regions of eastern Brazil, particularly inside the caatinga vegetation. It is characterized by slender, cylindrical, erect or decumbent, jointed stems that develop a woolly and bristly apical cephalium from which bright, tubular flowers emerge, adapted for hummingbird pollination.
• Arrojadoa penicillata — A particular cactus species within the Arrojadoa genus, endemic to the state of Bahia in Brazil. It is distinguished by slender, highly branched, and often shrubby stems whose segmented tips form a dense apical cephalium covered with fine, long hairs resembling a small brush (penicillate), from which vivid pink or purplish-red tubular flowers erupt.
• Arrojadoa rhodantha — A xerophytic species of cactus within the Arrojadoa genus, endemic to eastern Brazil (particularly in the states of Piauí, Ceará, Pernambuco, and Bahia), characterized by cylindrical, semi-erect or scrambling stems that develop a ringed apical cephalium covered with brownish or white wool and stiff reddish bristles. Its flowers are tubular, intense pink-magenta or bright red, adapted for hummingbird pollination within rocky caatinga habitats.
• Arthrocereus — A genus of succulent plants in the Cactaceae family, endemic to the mountainous and arid regions of Brazil, particularly in the state of Minas Gerais. These species are structurally characterized by thin, cylindrical, poorly branched or decumbent stems, covered with dense and fine spines, producing large, nocturnal, white or pale-pink flowers adapted for pollination by moths.
• Arthrocereus microsphaericus — The scientific name of a rare and endangered cactus species belonging to the Arthrocereus genus, found exclusively in the mountainous regions of eastern Brazil. The plant is structurally recognized by its very small globular or cylindrical segments (hence the name 'microsphaericus'), with reduced spines, forming compact clumps at soil level and bearing major ecological importance in biodiversity conservation.
• Assuan — An alternative or historical toponymic form used in Romanian for the city and governorate of Aswan in southern Egypt, situated at the first cataract of the Nile; globally renowned for its giant dam complex (especially the Aswan High Dam, built in the 20th century to control floods and generate power) and for the historic salvage relocation of the ancient Abu Simbel temples under UNESCO.
• Astralite — A technical term used to denote a special type of opaque glass, glass-ceramic, or refractory material enriched with mineral compounds, structurally designed to withstand extreme thermal shocks and mimic the crystalline reflections of stellar bodies. In a restricted sense, it was also used in the older commercial nomenclature of safe ammonium nitrate-based industrial explosives used in mining.
• Astrophytum — A genus of succulent plants within the Cactaceae family, native to the arid and semi-desert regions of Mexico and the southern United States (Texas). These cacti are characterized by globose or cylindrical stems, often lacking spines in adult state, decorated with prominent ribs and microscopic white dots formed by coarse hairs (trichomes), possessing a general star-like appearance reminiscent of a star or marine astroid.
• Astrophytum asterias — An endemic species of small succulent plants within the Astrophytum genus (Cactaceae family), with a globose, flattened stem completely lacking spines, typically divided into exactly 8 flat, regular ribs. Its greenish-grey surface is decorated with numerous trichomes (microscopic white dots made of tiny hairs), featuring large, woolly areoles in the center from which yellow flowers with a red-orange center emerge; it is a protected species, endangered in its native habitat of Mexico and Texas.