Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. The process of biodegradation can be divided into three stages: biodeterioration and assimilation. Biodeterioration is sometimes described as a surface-level degradation that modifies the mechanical and chemical properties of the material; this stage occurs when the material is exposed to abiotic factors in the outdoor environment and allows for further degradation by weakening the material's structure. Some abiotic factors that influence these initial changes are compression, light and chemicals in the environment. While biodeterioration occurs as the first stage of biodegradation, it can in some cases be parallel to biofragmentation. Hueck, defined Biodeterioration as the undesirable action of living organisms on Man's materials, involving such things as breakdown of stone facades of buildings, corrosion of metals by microorganisms or the esthetic changes induced on man-made structures by the growth of living organisms.
Biofragmentation of a polymer is the lytic process in which bonds within a polymer are cleaved, generating oligomers and monomers in its place. The steps taken to fragment these materials differ based on the presence of oxygen in the system; the breakdown of materials by microorganisms when oxygen is present, it's aerobic digestion. And the breakdown of materials when oxygen is not present, is anaerobic digestion; the main difference between these processes is that anaerobic reactions produce methane, while aerobic reactions do not. In addition, aerobic digestion occurs more than anaerobic digestion, while anaerobic digestion does a better job reducing the volume and mass of the material. Due to anaerobic digestion's ability to reduce the volume and mass of waste materials and produce a natural gas, anaerobic digestion technology is used for waste management systems and as a source of local, renewable energy; the resulting products from biofragmentation are integrated into microbial cells, this is the assimilation stage.
Some of the products from fragmentation are transported within the cell by membrane carriers. However, others still have to undergo biotransformation reactions to yield products that can be transported inside the cell. Once inside the cell, the products enter catabolic pathways that either lead to the production of adenosine triphosphate or elements of the cells structure. In practice all chemical compounds and materials are subject to biodegradation processes; the significance, however, is in the relative rates of such processes, such as days, years or centuries. A number of factors determine the rate. Factors include light, water and temperature; the degradation rate of many organic compounds is limited by their bioavailability, the rate at which a substance is absorbed into a system or made available at the site of physiological activity, as compounds must be released into solution before organisms can degrade them. The rate of biodegradation can be measured in a number of ways. Respirometry tests can be used for aerobic microbes.
First one places a solid waste sample in a container with microorganisms and soil, aerates the mixture. Over the course of several days, microorganisms digest the sample bit by bit and produce carbon dioxide – the resulting amount of CO2 serves as an indicator of degradation. Biodegradability can be measured by anaerobic microbes and the amount of methane or alloy that they are able to produce. It's important to note factors that affect biodegradation rates during product testing to ensure that the results produced are accurate and reliable. Several materials will test as being biodegradable under optimal conditions in a lab for approval but these results may not reflect real world outcomes where factors are more variable. For example, a material may have tested as biodegrading at a high rate in the lab may not degrade at a high rate in a landfill because landfills lack light and microbial activity that are necessary for degradation to occur. Thus, it is important that there are standards for plastic biodegradable products, which have a large impact on the environment.
The development and use of accurate standard test methods can help ensure that all plastics that are being produced and commercialized will biodegrade in natural environments. One test, developed for this purpose is DINV 54900; the term Biodegradable Plastics refers to a material that maintains its mechanical strength during practical use but break down into low-weight compounds and non-toxic byproducts after their use. This breakdown is made possible through an attack of microorganisms on the material, a non-water-soluble polymer; such materials can be obtained through chemical synthesis, fermentation by microorganisms, from chemically modified natural products. Plastics biodegrade at variable rates. PVC-based plumbing is selected for handling sewage; some packaging materials on the other hand are being developed that would degrade upon exposure to the environment. Examples of synthetic polymers that biodegrade include polycaprolactone, other polyesters and aromatic-aliphatic esters, due to their ester bonds being susceptible to attack by water.
A prominent example is poly-3-hydroxybutyrate, the renewably derived polylactic acid. Others are the cellulose-based cellulose celluloid. Under low oxygen conditions plastics break down more slowly; the breakdown process can be accelerated in speci
Everybody Loves Lil' Chris is a television series broadcast by Channel 4 in 2008 and presented by the singer and performer Lil' Chris. Broadcast in October and November 2008, 18-year-old Lil' Chris hosted seven episodes of Everybody Loves Lil' Chris on the T4 strand of Channel 4 on Saturday mornings; each episode ran for 23 minutes. The series was a mixture of comedy, celebrity interviews, live music performances and various'challenges' that Hardman undertook, including busking while dressed as a wild animal, visiting a haunted location and cage fighting. Another feature of the programmes was'Lil' Chris' Big Eight', in which celebrity guests were quizzed on what they knew about the lives of such media personalities as Paris Hilton and Geri Halliwell; the airing of the shows coincided with the release of Hardman's second album What's It All About in October 2008. Guests on the series included Robyn, The Hoosiers, Shayne Ward, Keith Lemon, Katy Perry, The Feeling, Jack Osbourne, The Sugababes, The Script, George Sampson, The Saturdays, Jonas Brothers, New Kids on the Block, Cage the Elephant, Kevin Bishop, Scouting for Girls, Will Young and Ne-Yo.
The Executive Producers were Peter Penny. The series was directed by John Pereira, was produced by Gareth Collett. Everybody Loves Lil' Chris on IMDb
Positive was a Filipino drama series, broadcast on TV5. It follows the story of Carlo Santillan, played by Martin Escudero, a call center agent who, after having lived a hedonistic lifestyle discovers that he has since developed HIV/AIDS, attempts to track down who might have infected him; the series, directed by Eric Quizon, was the Philippines' first television program that directly dealt with the topic of HIV/AIDS. It premiered on at 9:00 pm on October 17, 2013 as part of TV5's primetime block, Unlike regular Philippine dramas, which air episodes daily, episodes of Positive aired weekly on Thursdays. Positive ended on January 2014, after a thirteen-episode run. Positive follows the story of Carlo Santillan, who since grade school without knowing lived a hedonistic lifestyle. Describing himself as the "life of the party", he consumed drugs and alcohol, had numerous sexual partners since he was 12 years old. After entering rehab at the urging of his mother, Carlo has attempted to set his life straight: he has found work as a call center agent, rising through the ranks until he became operations manager, has since married his wife, who he met when high school, and, three months pregnant with their child.
Despite setting his life straight, Carlo started developing recurrent pneumonia symptoms, at the urging of his doctor, had his blood screened for possible HIV infection. The tests show that despite appearing healthy, not only is he HIV-positive, but he has developed AIDS. Carlo attempts to retrace his past in order to determine, the person that might have infected him with the virus. Martin Escudero portrays Carlo Santillan, the operations manager of a call center who, after having lived a hedonistic lifestyle, discovers that he has developed HIV/AIDS. Afraid of dying young and angry at his lot, he attempts to retrace his past to determine who might have infected him with HIV. Helga Krapf portrays Carlo's wife. Janis meets Carlo while in high school, where she rebuffs his advances until they get married after he exits rehab. Pregnant with their three-month-old child, she is oblivious to the fact that her husband is HIV-positive. Felix Roco portrays Carlo's best friend. A guitarist in a rock band at a local bar, he continues to live the same hedonistic lifestyle he lived with Carlo while in high school.
He is the first person to know that his best friend is infected with HIV. Bing Loyzaga portrays Esther Santillan, Carlo's mother. A principal at a local elementary school, she was the one who urged her son to enter rehab, supported him in his attempt to overcome his hedonistic lifestyle. Alwyn Uytingco portrays Jeffy, he is the only son of a famous land developer. Filthy rich and gay, he's a permanent fixture in a known drug dealer. Carlo thinks something might have happened between him and Jeffy in the past, making the latter one of his suspects. Malak So Shdifat portrays Miles de Guzman, she is a team leader under his sometime booty call. She is his first suspect because she is open to him about sleeping around with different guys whenever her OFW boyfriend is not here. Bianca Manalo portrays Anne, she is a popular yoga instructor who, unknown to many, has been living with HIV. She volunteers as an HIV helps Carlo deal with his situation. Rufa Mae Quinto portrays Maricris. Carlo met Maricris on Facebook.