A high cross or standing cross is a free-standing Christian cross made of stone and richly decorated. There was a unique Early Medieval tradition in Ireland and Britain of raising large sculpted stone crosses outdoors; these developed from earlier traditions using wood with metalwork attachments, earlier pagan Celtic memorial stones. The earliest surviving examples seem to come from the territory of the Anglo-Saxon kingdom of Northumbria, converted to Christianity by Irish missionaries, their relief decoration is a mixture of religious figures and sections of decoration such as knotwork, interlace and in Britain vine-scrolls, all in the styles found in insular art in other media such as illuminated manuscripts and metalwork. They were normally painted over a modelled layer of plaster; the earlier crosses were up to about two metres or eight feet high, but in Ireland examples up to three times higher appear retaining thick massive proportions, giving large surface areas for carving. The tallest of the Irish crosses is the so-called Tall Cross at County Louth.
It stands at twenty-two feet high. Anglo-Saxon examples remained slender in comparison, but could be large; the crosses though not always, feature a stone ring around the intersection, forming a Celtic cross. The term "high cross" is used in Ireland and Scotland, but the tradition across Britain and Ireland is a single phenomenon, though there are strong regional variations; some crosses were erected just outside monasteries. Whether they were used as "preaching crosses" at early dates is unclear, many crosses have been moved to their present locations, they do not seem to have been used as grave-markers in the early medieval period. In the 19th century Celtic Revival Celtic crosses, with decoration in a form of insular style, became popular as gravestones and memorials, are now found in many parts of the world. Unlike the Irish originals, the decoration does not include figures. High crosses are the primary surviving monumental works of Insular art, the largest number in Britain survive from areas that remained under Celtic Christianity until late.
No examples, or traces, of the putative earlier forms in wood or with metal attachments have survived. Saint Adomnán, Abbot of Iona who died in 704, mentions similar free standing ringed wooden crosses replaced by stone versions; the earliest surviving free-standing stone crosses are at Carndonagh, which appear to be erected by missionaries from Iona. Fleeing the Viking raiders, "giving Iona a critical role in the formation of ringed crosses"; the round bosses seen on early crosses derive from Pictish stones. High crosses may exist from the 7th century in Northumbria, which included much of south-east Scotland, Ireland, though Irish dates are being moved later; however the dates assigned to most of the early crosses surviving in good condition, whether at Ruthwell and Bewcastle, the Western Ossory group in Ireland, Iona or the Kildalton Cross on Islay, have all shown a tendency to converge on the period around or before 800, despite the differences between the Northumbrian and Celtic types. The high cross spread to the rest of the British Isles, including the Celtic areas of Wales, Devon and Cornwall, where ogham inscriptions indicate an Irish presence, some examples can be found on Continental Europe where the style was taken by Insular missionaries.
Most Irish High crosses have the distinctive shape of the ringed Celtic cross, they are larger and more massive, feature more figural decoration than those elsewhere. They have more survived as well; the ring served to strengthen the head and the arms of the high cross, but it soon became a decorative feature as well. The high crosses were status symbols, either for a monastery or for a sponsor or patron, preaching crosses, may have had other functions; some have inscriptions recording the donor who commissioned them, like Muiredach's High Cross and the Bewcastle Cross. The earliest 8th- or 9th-century Irish crosses had only ornament, including interlace and round bosses, but from the 9th and 10th century, figurative images appear, sometimes just a figure of Christ crucified in the centre, but in the largest 10th century examples large numbers of figures over much of the surface; some late Irish examples have fewer figures, approaching life-size, carved in high relief. The Irish tradition died out after the 12th century, until the 19th-century Celtic Revival, when the Celtic cross form saw a lasting revival for gravestones and memorials just using orname
Pesticides are substances that are meant to control pests, including weeds. The term pesticide includes all of the following: herbicide, insecticides nematicide, piscicide, rodenticide, insect repellent, animal repellent and fungicide; the most common of these are herbicides which account for 80% of all pesticide use. Most pesticides are intended to serve as plant protection products, which in general, protect plants from weeds, fungi, or insects. In general, a pesticide is a chemical or biological agent that deters, kills, or otherwise discourages pests. Target pests can include insects, plant pathogens, molluscs, mammals, fish and microbes that destroy property, cause nuisance, or spread disease, or are disease vectors. Along with these benefits, pesticides have drawbacks, such as potential toxicity to humans and other species; the Food and Agriculture Organization has defined pesticide as: any substance or mixture of substances intended for preventing, destroying, or controlling any pest, including vectors of human or animal disease, unwanted species of plants or animals, causing harm during or otherwise interfering with the production, storage, transport, or marketing of food, agricultural commodities and wood products or animal feedstuffs, or substances that may be administered to animals for the control of insects, arachnids, or other pests in or on their bodies.
The term includes substances intended for use as a plant growth regulator, desiccant, or agent for thinning fruit or preventing the premature fall of fruit. Used as substances applied to crops either before or after harvest to protect the commodity from deterioration during storage and transport. Pesticides can be classified by target organism, chemical structure, physical state. Biopesticides include biochemical pesticides. Plant-derived pesticides, or "botanicals", have been developing quickly; these include the pyrethroids, nicotinoids, a fourth group that includes strychnine and scilliroside. Many pesticides can be grouped into chemical families. Prominent insecticide families include organochlorines and carbamates. Organochlorine hydrocarbons could be separated into dichlorodiphenyl ethanes, cyclodiene compounds, other related compounds, they operate by disrupting the sodium/potassium balance of the nerve fiber, forcing the nerve to transmit continuously. Their toxicities vary but they have been phased out because of their persistence and potential to bioaccumulate.
Organophosphate and carbamates replaced organochlorines. Both operate through inhibiting the enzyme acetylcholinesterase, allowing acetylcholine to transfer nerve impulses indefinitely and causing a variety of symptoms such as weakness or paralysis. Organophosphates are quite toxic to vertebrates and have in some cases been replaced by less toxic carbamates. Thiocarbamate and dithiocarbamates are subclasses of carbamates. Prominent families of herbicides include phenoxy and benzoic acid herbicides, triazines and Chloroacetanilide. Phenoxy compounds tend to selectively kill broad-leaf weeds rather than grasses; the phenoxy and benzoic acid herbicides function similar to plant growth hormones, grow cells without normal cell division, crushing the plant's nutrient transport system. Triazines interfere with photosynthesis. Many used pesticides are not included in these families, including glyphosate; the application of pest control agents is carried out by dispersing the chemical in a solvent-surfactant system to give a homogeneous preparation.
A virus lethality study performed in 1977 demonstrated that a particular pesticide did not increase the lethality of the virus, however combinations which included some surfactants and the solvent showed that pretreatment with them markedly increased the viral lethality in the test mice. Pesticides can be classified based upon their biological mechanism application method. Most pesticides work by poisoning pests. A systemic pesticide moves inside a plant following absorption by the plant. With insecticides and most fungicides, this movement is upward and outward. Increased efficiency may be a result. Systemic insecticides, which poison pollen and nectar in the flowers, may kill bees and other needed pollinators. In 2010, the development of a new class of fungicides called; these work by taking advantage of natural defense chemicals released by plants called phytoalexins, which fungi detoxify using enzymes. The paldoxins inhibit the fungi's detoxification enzymes, they are believed to be greener.
Since before 2000 BC, humans have utilized pesticides to protect their crops. The first known pesticide was elemental sulfur dusting used in ancient Sumer about 4,500 years ago in ancient Mesopotamia; the Rig Veda, about 4,000 years old, mentions the use of poisonous plants for pest control. By the 15th century, toxic chemicals such as arsenic and lead were being applied to crops to kill pests. In the 17th century, nicotine sulfate was extracted from tobacco leaves for use as an insecticide; the 19th century saw the introduction of two more natural pesticides, derived fr
Ponnani State assembly constituency is one of the 140 state legislative assembly constituencies in Kerala. It is one of the 7 state legislative assembly constituencies included in the Ponnani Lok Sabha constituency. Ponnani Niyama Sabha constituency is composed of the following local self governed segments: The following list contains all members of Kerala legislative assembly who have represented Ponnani Niyama Sabha Constituency during the period of various assemblies::Key CPI INC IUML Independent Percentage change denotes the change in the number of votes from the immediate previous election. There were 1,90,774 registered voters in Ponnani Constituency for the 2016 Kerala Niyama Sabha Election. Ponnani Malappuram district List of constituencies of the Kerala Legislative Assembly 2016 Kerala Legislative Assembly election Remaining Date for Ponnani Municipality Election 2020