A cohort study is a particular form of longitudinal study that samples a cohort, performing a cross-section at intervals through time. It is a type of panel study. Cohort studies represent one of the fundamental designs of epidemiology which are used in research in the fields of medicine, psychology, social science, in any field reliant on'difficult to reach' answers that are based on evidence. In medicine for instance, while clinical trials are used for assessing the safety of newly developed pharmaceuticals before they are approved for sale, epidemiological analysis on how risk factors affect the incidence of diseases is used to identify the causes of diseases in the first place, to help provide pre-clinical justification for the plausibility of protective factors. Cohort studies differ from clinical trials in that no intervention, treatment, or exposure is administered to participants in a cohort design. Rather, cohort studies are about the life histories of segments of populations, the individual people who constitute these segments.
Exposures or protective factors are identified as preexisting characteristics of participants. The study is controlled by including other common characteristics of the cohort in the statistical analysis. Both exposure/treatment and control variables are measured at baseline. Participants are followed over time to observe the incidence rate of the disease or outcome in question. Regression analysis can be used to evaluate the extent to which the exposure or treatment variable contributes to the incidence of the disease, while accounting for other variables that may be at play. Double-blind randomized controlled trials are considered superior methodology in the hierarchy of evidence in treatment, because they allow for the most control over other variables that could affect the outcome, the randomization and blinding processes reduce bias in the study design; this minimizes the chance that results will be influenced by confounding variables ones that are unknown. However, educated hypotheses based on prior research and background knowledge are used to select variables to be included in the regression model for cohort studies, statistical methods can be used to identify and account potential confounders from these variables.
Bias can be mitigated in a cohort study when selecting participants for the cohort. It is important to note that RCTs may not be suitable in all cases. Ethical standards, morality, would prevent the use of risk factors in RCTs; the natural or incidental exposure to these risk factors, or self-administered exposure, can be measured without subjecting participants to risk factors outside of their individual lifestyles and choices. Cohort studies can be prospective. Retrospective cohort studies restrict the investigators ability to reduce confounding and bias because collected information is restricted to data that exists. There are advantages to this design however, as retrospective studies are much cheaper and faster because the data has been collected and stored. A cohort is a group of people who share a common characteristic or experience within a defined period, thus a group of people who were born on a day or in a particular period, say 1948, form a birth cohort. The comparison group may be the general population from which the cohort is drawn, or it may be another cohort of persons thought to have had little or no exposure to the substance under investigation, but otherwise similar.
Alternatively, subgroups within the cohort may be compared with each other In medicine, a cohort study is undertaken to obtain evidence to try to refute the existence of a suspected association between cause and effect. Crucially, the cohort is identified before the appearance of the disease under investigation; the study groups follow a group of people who do not have the disease for a period of time and see who develops the disease. The cohort cannot therefore be defined as a group of people who have the disease. Prospective cohort studies between exposure and disease aid in studying causal associations, though distinguishing true causality requires further corroboration from further experimental trials; the advantage of prospective cohort study data is that it can help determine risk factors for contracting a new disease because it is a longitudinal observation of the individual through time, the collection of data at regular intervals, so recall error is reduced. However, cohort studies are expensive to conduct, are sensitive to attrition and take a long follow-up time to generate useful data.
The results that are obtained from long-term cohort studies are of superior quality to those obtained from retrospective/cross-sectional studies. Prospective cohort studies are considered to yield the most reliable results in observational epidemiology, they enable a wide range of exposure-disease associations to be studied. Some cohort studies track groups of children from th
Dudley Pond is an 84 acre Great Pond in the Cochituate census-designated area of Wayland, Massachusetts. The Pond is a shallow glacial landform fed by rain. Dudley Pond was used in the mid-1800s as a stand-by water source for Boston. At the time it was connected by pipe to much larger Lake Cochituate. In the 1920s and 30s the Pond became center for nightlife and Prohibition-breaking, with a concomitant decline in habitat and sanitation. Efforts to restore the environment beginning in the mid-century returned the Pond to a high standard of water quality. More Dudley Pond has been a vacation spot, residential area, community recreation site. Notable residents of the Pond area include current resident George Howell; the Pond has one eatery, The Dudley Chateau. Recreation activities include public boating; the Pond is owned on a long-term lease. Since 1968 its health and habitat have been monitored by the Dudley Pond Association, a non-profit corporation; the Dudley Pond Association website A history of Dudley Pond The Dudley Pond Association Facebook page
The Legend of God's Gun is a 2007 American independently produced film celebrating the tradition of western films and the spirit of Rock and Roll. The film is based on the psychedelic Western album of the same name by the band Spindrift—the album having preceded the production of the film by a number of years. A gun-slinging preacher returns to the debaucherous town of Playa Diablo seeking revenge from the notorious scorpion-venom drinking bandito El Sobero, a descendant of a disciple of King Tavatta—the Scorpion King from the ancient world. El Sobero and his band of bad banditos are returning to Playa Diablo seeking their own revenge against the town sheriff for putting a bounty on their heads and subsequently shooting all of their horses. With the Bounty Hunter dragging up behind there is sure to be a confrontation of Biblical proportions as they all meet in the circle of death; this is The Legend Of God's Gun. Death Valley Pioneertown, California Hollywood Hills The Legend Of God's Gun on IMDb Indican Pictures Official Myspace Film Profile
The 2012 Sepang GP2 Series round was a GP2 Series motor race held on March 24 and 25, 2012 at Sepang International Circuit, Malaysia. It was the first round of the 2012 GP2 Series season; the race weekend supported the 2012 Malaysian Grand Prix. Davide Valsecchi was on pole for the feature race, won by Luiz Razia. James Calado won the sprint race. Notes ^1 – Onidi received a three grid place penalty for impeding González during the qualifying session. Notes: ^2 — Stéphane Richelmi and Simon Trummer were both issued with twenty-second time penalties after the race when they were judged to have caused an avoidable collision. ^3 — Jolyon Palmer and Tom Dillmann started from the pit lane. Notes: ^4 — Stefano Coletti and Ricardo Teixeira were both classified as having finished the race, as they had completed 90% of the winners race distance. Note: Only the top five positions are included for both sets of standings. GP2 Series official website – Results
Heavy Lies the Crown is the fifth studio album by underground hip hop collective Army of the Pharaohs. The album had an initial release set for November 2014, but it was confirmed that it would be released a month earlier on October 21, 2014 via Vinnie Paz's independent record label, Enemy Soil. On August 6, 2014, it was announced that Heavy Lies the Crown would be released on October 21, 2014, six months after their previous album In Death Reborn. King Magnetic is the only artist from the previous album to not make an appearance. Lawrence Arnell makes two guest appearances on the album after he was featured on one track on In Death Reborn. Album credits adapted from AllMusic
ICI Pakistan Limited known as Imperial Chemical Industries, is a Pakistani chemical company, based in Karachi, Pakistan. It manufactures polyester, pharmaceuticals and soda ash. In 2012, Yunus Brothers Group acquired the company for $152m from the Dutch paints giant AkzoNobel; the company's history dates back to British colonial-era when it was established as Khewra Soda Ash Company in 1944. They set up a soda ash manufacturing facility in Khewra with a capacity of 18,000 tonnes per annum; this facility was sited next as rock salt and limestone. In 1995, ICI Pakistan Limited set up a USD 490 million PTA manufacturing facility at Port Qasim, near Karachi, commissioned in 1998. In 2001, the business was demerged or spun off to form Pakistan PTA Limited, a subsidiary of ICI Plc UK. In 2008, Dutch paints and chemicals giant AkzoNobel bought out the global parent company Imperial Chemical Industries. ICI Pakistan is one of the largest quoted companies on the Pakistan Stock Exchange with a paid up share capital of Rs 1.39 billion.
The company has around 1,294 permanent employees and around the same numbers of people provide services through contractual arrangements. ICI Pakistan pioneered Polyester Staple Fibre technology in Pakistan through its investment in a 12,000 tonnes per annum PSF Plant commissioned in 1982 in Sheikhupura, near Lahore. Polyester fibre is used in cars and clothes. While the soda ash plant dates back to 1939, commercial production began in 1944. Over the years, the capacity of the plant has been increased through expansion in line with market demand; the total capacity of the plant today is 425,000 tons per annum. In 1995, the business commissioned a 10ktpa plant for the manufacture of Sodium bicarbonate, further expanded to 20ktpa in 2004 and 30 ktpa in 2015. Besides, the business has a production capacity of 500 tons per day of dense ash, an essential raw material for glass making. ICI Pakistan’s soda ash business caters to 70% of the country’s total Soda Ash requirement; the Business uses indigenous raw materials and locally made equipment.
The plant is located near the Khewra salt range. The Life Sciences Business consists of two divisions. ICI Pakistan Chemicals and Agri Business consists of General Chemicals and Specialty Chemicals as well as Agriculture Products ranging from seeds to pesticides; the General Chemicals Segment includes trading and polyurethanes and is involved in the import, manufacturing and distribution of industrial chemicals. The trading segment comprises a portfolio of fourteen product groupings with over 250 products/variants, including trading partners such as National Starch & Chemicals, Huntsman Polyurethanes, Ineos Chlor, Huntsman Tioxide, supplemented by imports of complementary product lines from companies in the USA, Europe and the Far East; this Segment markets a product range used for various applications including power, textiles, pharmaceuticals, personal care, food & beverage, detergents and household appliances. Since 2014, ICI Pakistan is importing and distributing selected Morinaga Milk Industry of Japan's infant milk formula products under the brand name of NutriCo Pakistan.
ICI Pakistan operates factories in the following cities: Lahore Sheikhupura Khewra Karachi Hattar, Pakistan In 2018, ICI Pakistan was awarded the Gallup Pakistan's'Gallup Great Workplace Award'. ICI Pakistan official site Company Profile and stock quote of ICI Pakistan on Pakistan Stock Exchange website