Thursday, April 9, 2020
The peyote plant Essay Example For Students
The peyote plant Essay Drug use has always been a topic of controversy, especially when it pertains to religion. One particular drug that has been brought to the attention of the federal government is Peyote. Peyote is a drug that has been used by the Native Americans for thousands of years. This drug, Peyote which has caused much controversy over the years has recently been reconsidered for legal use. Probably the most famous New World hallucinogenic plant is Peyote,(Lophoproria willamsii), a small spineless cactus, native to the Rio Grande Valleyof Texas. Also in the northern and central parts of the Mexican Plateau Region. Another species (Lidiffuss) is native to the Mexican State of Quertono. The rounded, gray-green stem crown (top) is radially divided into sections, eachoffering a small meristematic region (called an areole) from which arises a tuft of hairs. The crown tapers into a thick carrot-like root that extends into the ground(Mescal Bean N. Pag.). There are many different chemicals in the Peyote cactus, the main one being mescaline. Mescaline, which can be made in a lab, was isolated in 1919, resembling epinephrine, the adrenal hormone (Peyote 1 Pag). We will write a custom essay on The peyote plant specifically for you for only $16.38 $13.9/page Order now The Peyote cactus contains more than 50 different alkaloids, but the most active hallucinogen is mescaline. Mescaline has a chemical structure similar to the brainneurotransmitter dopamine (MescalBean N. Pag.). It is also structurally similar to the neurohormone norepinephrine (noradrenaline) and to the stimulant amphetamine. In the Peyote cactus, mescaline is formed in a complex path way from the Amino Acid tyrosine. Mescaline provides psychologic disorientation with brilliant, ever changing colors. Mescaline hallucinations produce audio visual affects, double personality, derealization (loss of sense of reality of environment) and depersonalization (shattered personality). Peyote was dried and eaten by Southwest Indians at religious services for sense of well being, hallucinations (visions) and trances (Peyote N. Pag.). Native Americans use this drug as part of their religious ceremonies. The users slice off and eat peyote crowns fresh or dried. Peyote buttons last years, swallowed whole or drunk in tea. According to Clairdone, large amounts of peyote can induce hallucinations, adherents say the quantities normally taken in religious rites bring on only an introspective mood that gives the user insight to the spiritual world. This is not something American Indians have made up in the past hundred years. Mescal Beans have been discovered in Indian sites dating before A.D. 1000, and from one site dating back to 1500 B.C. (Mescal Bean N. Pag.). Ever since the arrival of the first Europeans in the New World, Peyote has provoked controversy. Supression and persecution (Scnultes N. Pag.). Peyote, in its natural state is not a dangerous drug, however, synthetic peyote causes harmful side effects. According to the article Peyote 1 and magic Mushrooms, Synthetic peyote lowers blood pressure, depresses the central Nervous system and kills by respiratory failure. Since Peyote is a drug that produces hallucinogenic affects, the military reached an agreement with the Native American church to honor the use of peyote for Native Americans in the Military, except for those who operate nuclear weapons. Other restrictions were said to include a prohibition against the use of peyote on military vehicles, aircraft, or ships; a requirement to stop using the drug 24 hours before returning to active duty. According to Clairdone, Church sources said fears of hallucinogenic flashbacks that were raised by officials of the Strategic Air Command de layed formal implementation of the draft rules and raised bitter resentment among devout native Americans who use peyote as a sacrament. Individual states had made laws that honoredthe peyote ritual, but peyote was still considered an illegal drug. According to Guy Mount, in his article, Peyote and the Law, Three states have exempted peyote from controlled substance prohibitions, and do permit the Bona-Fide sacramental use of peyote by non-Indians who are members of an established church: these are New York, Arizona, and New Mexico. A recent decision by the Supreme Court of the United States (1990) makes it clear that we do not have a Constitutional right to use any controlled substance as a religious sacrament. Instead, each state has the right to pass laws which honor the peyote religion, or continue to suppress it. Peyote is significant to Native American religious rituals and has been approved by the government for that purpose. On the legal front, Native Americans are secure in their right to use peyote for religious purposes (Glazer N. Pag.). According to the article Peyote Bill Signed, President Clinton signed into law on Oct. 6 2000, that guarantees the right of Native Americans to possess, transport, and use peyote in the course of traditional religious ceremonies. The bill passed the Senate on September 27, and passed the house August 8 by a voice vote. The bill was introduced by congressman Bill Richardson (D-Wm) and garnered bi-partisan support as well as support from the Drug Enforcement Administration (DEA). .u7700ad1127d6bfb1aed2838672e414a5 , .u7700ad1127d6bfb1aed2838672e414a5 .postImageUrl , .u7700ad1127d6bfb1aed2838672e414a5 .centered-text-area { min-height: 80px; position: relative; } .u7700ad1127d6bfb1aed2838672e414a5 , .u7700ad1127d6bfb1aed2838672e414a5:hover , .u7700ad1127d6bfb1aed2838672e414a5:visited , .u7700ad1127d6bfb1aed2838672e414a5:active { border:0!important; } .u7700ad1127d6bfb1aed2838672e414a5 .clearfix:after { content: ""; display: table; clear: both; } .u7700ad1127d6bfb1aed2838672e414a5 { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .u7700ad1127d6bfb1aed2838672e414a5:active , .u7700ad1127d6bfb1aed2838672e414a5:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .u7700ad1127d6bfb1aed2838672e414a5 .centered-text-area { width: 100%; position: relative ; } .u7700ad1127d6bfb1aed2838672e414a5 .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .u7700ad1127d6bfb1aed2838672e414a5 .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .u7700ad1127d6bfb1aed2838672e414a5 .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .u7700ad1127d6bfb1aed2838672e414a5:hover .ctaButton { background-color: #34495E!important; } .u7700ad1127d6bfb1aed2838672e414a5 .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .u7700ad1127d6bfb1aed2838672e414a5 .u7700ad1127d6bfb1aed2838672e414a5-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .u7700ad1127d6bfb1aed2838672e414a5:after { content: ""; display: block; clear: both; } READ: The Tempest: Caliban Unjustly Punished EssayThe passing of H.R. Y230, a bill amending the American Indian Religious Freedom Act into U.S. law, states that no federal government can enforce a law restricting traditional religious use of peyote by a member of an Indian tribe,Recognized by the United States Government (Glazer N. Pag.). In the article Peyote Okd, Non-native Americans were prosecuted for participating in the peyote ritual, but were acquitted because of the first amendment rights. The case concerned two drug counselors who lost their jobs for using peyote during Native American church religious rites. The court ruled that by denying these men their jobless benefits, the state violated the mens First Amendment right to freely practice their religion. After many years of controversy over the use of the peyote cactus, the American Federal government had finally accepted the use of peyote by native Americans, and has created a federal law which protects the religious rights of the people of the native American church. The victory over the battle of the use of peyote for native Americans is a giant step in regaining their heritage from its degradation by the American government. The legalization of peyote proves that not all drug uses are bad. Reconsidering peyote for legal use opens the door to other drug s, which may have been overlooked and improperly categorized as dangerous or harmful substances. Bibliography:Works CitedClaiborne, William. Military, Indian Church Agree On Peyote Online Availablehttp://www.seattletimes.com/news/nation-wo/peyo_19990630.htm,May 16, 2000. Glazer, Mark. Peyote among Huichols and Native American Church Members. Online Available http://www.panam.edu/dept/psychanth/peyote.htm, May 16, 2000. Mount, Guy. Peyote and the Law. Online Available http://www.druglibrary.org/Schaffer/lsd/peylaw.htm, May 16, 2000. The Mescal Bean and The Peyote Cactus. Online Available http://daphne.palomar.edu/wayne/ww0703.htm#peyote, May 16, 2000. Peyote 1 and Magic Mushrooms Online Available http://www.geocities.com/capitolhill/lobby/5418/dd-peyote1.html, May 16, 2000. Peyote Bill Signed. Online Available http://ndsn.org/nov94/peyote.html, May 16, 2000. Peyote Okd in Indian Rites. Online Available http://www.ifas.org/fw/8901/peyote.html, May 16, 2000. Schultes, Richard E. and Albert Hoffman. The Tracks of Little Deer. Online Available http://www.peyote.org/, May 16, 2000.
Monday, March 9, 2020
Free Essays on On The Road With Charles Kuraltlt
ON THE ROAD WITH CHARLES KURALT BY: CHARLES KURALT In the beginning, I thought to myselfâ⬠¦Ã¢â¬ this will be a very dull and boring bookâ⬠. But to my surprise, it turned out to be one of the best books Iââ¬â¢ve read in a while. How lucky Mr. Kuralt was to have seen that many walks of life! This book gave brief biographies on how ordinary Americans live their lives and how they impact others around them. These mini-biographies caught average Americans in the act of being themselves. This was not an acted out or staged by any means, these were sheer, humble acts of what being a great American and a good citizen is all about. Throughout his voyage, I found Mr. Kuralt to be: unbiased, desegregated, witty and charming. He would blend right in with each person as if he had known him or her for ages. For example, when he interviewed Betsy Miller of Winterville, NC, an elderly lady who opened her home to the hungry each day like clockwork. Everyday at the crack of dawn, she would get up to make biscuits. She expected nothing in return. From helping the homeless people, she simply got gratification out of having daily company and loved to help out her fellow. Another person, who impressed me as being a genuine gentleman, was Jethro Mann of Belmont, North Carolina. He spent most of his days making sure that each kid in his town had a bike to ride. He would spend his last dime on materials to fix up old abandoned bikes for kids to enjoy. Mr. Mann thought it was every childââ¬â¢s dream to have bicycle to ride when they wanted to. Along with being a sweet guy, he taught children respect by allowing them to ride his bikes on a rental basis butâ⬠¦ if the bike was misused or abused in any way, he would place stipulations on using it again. The child would be placed on a probationary period and was not allowed to ride for a while. It taught children the responsibility of using other peopleââ¬â¢s things and how to treat the bikes ... Free Essays on On The Road With Charles Kuraltlt Free Essays on On The Road With Charles Kuraltlt ON THE ROAD WITH CHARLES KURALT BY: CHARLES KURALT In the beginning, I thought to myselfâ⬠¦Ã¢â¬ this will be a very dull and boring bookâ⬠. But to my surprise, it turned out to be one of the best books Iââ¬â¢ve read in a while. How lucky Mr. Kuralt was to have seen that many walks of life! This book gave brief biographies on how ordinary Americans live their lives and how they impact others around them. These mini-biographies caught average Americans in the act of being themselves. This was not an acted out or staged by any means, these were sheer, humble acts of what being a great American and a good citizen is all about. Throughout his voyage, I found Mr. Kuralt to be: unbiased, desegregated, witty and charming. He would blend right in with each person as if he had known him or her for ages. For example, when he interviewed Betsy Miller of Winterville, NC, an elderly lady who opened her home to the hungry each day like clockwork. Everyday at the crack of dawn, she would get up to make biscuits. She expected nothing in return. From helping the homeless people, she simply got gratification out of having daily company and loved to help out her fellow. Another person, who impressed me as being a genuine gentleman, was Jethro Mann of Belmont, North Carolina. He spent most of his days making sure that each kid in his town had a bike to ride. He would spend his last dime on materials to fix up old abandoned bikes for kids to enjoy. Mr. Mann thought it was every childââ¬â¢s dream to have bicycle to ride when they wanted to. Along with being a sweet guy, he taught children respect by allowing them to ride his bikes on a rental basis butâ⬠¦ if the bike was misused or abused in any way, he would place stipulations on using it again. The child would be placed on a probationary period and was not allowed to ride for a while. It taught children the responsibility of using other peopleââ¬â¢s things and how to treat the bikes ...
Saturday, February 22, 2020
Total quality management Essay Example | Topics and Well Written Essays - 250 words
Total quality management - Essay Example The meaning of quality differs depending on the circumstances and perceptions held by a consumer. Its meaning is also largely time based and equally situational. For example, quality becomes a different concept when focus is on tangible products versus the perception of a quality service. Scholars have thus given a general definition which postulates that it is a fitness for intended use. This definition says that quality is being able to meet and exceed the expectations of the customer. Deming argues that the customerââ¬â¢s definition of quality is the one that genuinely matters. It is thus evident that having a clear definition is not easy. The concept of zero defects is advocated by Philip Crosby. The primary objective of total quality management is to bring the number of faults or defects to zero (Nigam 113). However, Juran and Deming disagree with Crosbyââ¬â¢s assertion that organizations should work towards having zero defects in services and products. This is on the grounds that customers have different tastes and preferences which are difficult to satisfy. Humans are not perfect and havingà zero defects is not perfection. It is concerned with a commitment by employees and understanding that processes should continually be enhanced and defective systems should be reworked and reorganized from the top down.à In conclusion, quality encompasses a broad aspect that makes it difficult to settle on one definition. Meeting and continually exceeding market demands constitutes quality. Having zero defects is in itself not realizing perfection as market demands are dynamic. Quality Guru Deming postulates that catchphrases like "Zero Defects" are in fact, counterproductive and may possibly de-emphasize the customs and tools linked with continuous
Wednesday, February 5, 2020
Unwritten Constitution Essay Example | Topics and Well Written Essays - 750 words
Unwritten Constitution - Essay Example Paineââ¬â¢s definition of constitution is based upon 4 premises: 1. the constitution precedes and establishes the system of government; 2. the people are the superior authority; 3. the constitution binds the Legislature and the Judiciary; 4. it is entrenched, designed to limit the powers of the Executive, and can only be changed by special procedures. Wheare, (1966), defines a constitution as: ââ¬Å"[T]he whole system of government of a country, the collection of rules which establish and regulate or govern the government.â⬠The Select Committee on the Constitution appointed in 2001 uses the following working definition: ââ¬Å"[T]he set of laws, rules and practices that create the basic institutions of the state, and its component and related parts, and stipulate the powers of those institutions and the relationship between the different institutions and between those institutions and the individual.â⬠In most constitutions a concentration of powers is avoided by keeping the legislature, executive and judicial powers separate. This ensures that certain rights of the citizen are beyond the reach of the organs of government and are entrenched by requiring a special legislative procedure if they are to be amended. However, commentators in the UK prefer a wider definition. ... Further as Bradley & Ewing point out: "In practice, a written constitution does not contain all the detailed rules upon which a government depends."6 The jurist and legal historian, Lord Hailsham believes that a written constitution is not necessary pointing out that: "The essential ingredientsare a strong executive based on an omnicompetent and elective legislatureregular electionspowerful and independent oppositionand limitedby convention and precedentand regulated more by checks and balances deriving from political constraints and necessities than by a written legal code policed by a Supreme Court."7 It is misleading to refer to the British Constitution as 'unwritten': "from the Magna Carta to the Local Government Acts most of our constitutional law is contained somewhere in the growing volumes of written Acts of Parliament."8 Hailsham sees no particular reason for a codified constitution since he argues that: "Throughout our history, our Constitution has proved flexible, sensitive and almost infinitely capable of evolutionary adaptation. "9 The flexibility of an 'unwritten' constitution allows the people to vote out the Executive when necessary and for majority rule. Countries with written constitutions have the equivalent of a Constitutional Court which has a remit to amend the constitution.10 "It is an axiom of our constitutional law that no parliament may bind its successor.A traditional constitution, changing and evolving with the needs of a nation, may well prove more flexible and practical than the legal strait-jacket imposed by a 'written Constitution'."11 As examples Hailsham looks at the first two articles of
Tuesday, January 28, 2020
Urea Recycling in Ruminants
Urea Recycling in Ruminants Animals have a certain state of protein metabolism, varying from negative to positive protein balances. This balance level is influenced e.g. by the efficiency of nitrogen (N) utilization in animals. A simple strategy to increase the efficiency of N utilization is by reducing the N content in the feed converted to urea, for which a correlation of about r2=0.77 was found. However, this was mainly based on studies with mature or slow growing, small ruminants in which most of the absorbed N is converted to urea to maintain the N balance of the whole body close to zero (Lapierre and Lobley, 2001). More recent and extensive data show much weaker correlations between N intake and urea production for growing sheep (r2=0.33) and cattle (r2=0.58). Moreover, this strategy is not always realizable due to minimal absolute N requirements in animal feed, especially for growing animals. In addition to N intake, the protein balance level is influenced by the efficiency of N recycling in animals, especially in ruminants. Nitrogen recycling takes place between blood and the digestive tract in the form of endogenous protein-N, secreted-N (e.g. enzymes in saliva) and urea-N (Reynolds and Kristensen, 2008). In this chapter, the recycling of urea-N is explained. Amino acids and ammonia, which are absorbed from the digestive tract, are converted to urea in the liver. Urea (re)enters the digestive tract, mainly through the rumen wall, where it can be absorbed again or be (re)used for microbial protein synthesis and finally anabolic purposes. Amino acids and ammonia are absorbed into the portal bloodstream and converted into urea in the liver (ureagenesis). Urea can reenter the rumen, where it can be absorbed (again) or be used for microbial protein synthesis. Absorption of amino acids and ammonia Urea is the mammalian end-product of the amino acid metabolism. In the rumen, proteins are degraded into amino acids and finally into ammonia (NH3) by means of rumen fermentation (Shingu et al., 2007). Then, absorption of both amino acids and NH3 through the rumen wall and entrance into the portal circulation to the liver can take place (figure 3.1). The NH3 absorption depends on the pH and the ratio of NH3 to NH4 in the rumen (Siddons et al., 1985). Ureagenesis In the liver, detoxification of NH3 takes place, because urea is synthesized from the nitrogen (N) compound of both NH3 and amino acids (which appear in the portal circulation due to absorption from the intestine into the blood) (Obitsu and Taniguchi, 2009). The synthesis of urea, called ureagenesis, takes place by means of the urea or ornithine cycle. This cycle of biochemical reactions occurs in many animals that produce urea ((NH2)2CO) from ammonia (NH3), mainly in the liver and to a lesser extent in the kidney. The key compound is ornithine, which acts as a carrier on which the urea molecule is built up. At the end of the reaction sequence, urea is released by the hydrolysis of arginine, yielding ornithine to start the cycle again (Bender, 2008). Mitochondrial ammonia and cytosolic aspartate are precursors for the ornithine cycle (Van den Borne et al., 2006). The presence of arginine is needed to produce ornithine in the body, so higher levels of this amino acid should increase o rnithine production. Furthermore, ornithine, citrulline and arginine (all components of the ornithine cycle) seem to stimulate urea synthesis, with a concurrent decrease in plasma ammonia. Temporarily high ammonia fluxes seem to stimulate amino acid utilization for ureagenesis (Milano and Lobley, 2001). Urea is produced in the liver in greater amounts than which is eliminated in the urine. This is because urea from the liver is released to the blood circulation and then, next to excretion in the urine also is reabsorbed in the distal renal tubules, where it maintains an osmotic gradient for the reabsorption of water (Bender, 2008). Furthermore, urea from the blood can re-enter the digestive tract via saliva, secretions or directly across the rumen wall in the form of endogenous proteins or urea respectively (Lapierre and Lobley, 2001; Shingu et al., 2007; Obitsu and Taniguchi, 2009). Thus not all urea is secreted directly into the urine after entering the bloodstream. Entry into digestive tract Entry of urea into the digestive tract is, until certain concentrations (sheep: 6 mM (= 84 mg/L); cattle: 4 mM (= 56 mg/L) (Harmeyer and Martens, 1980; cattle: 80 mg/L (Kennedy and Milligan, 1978)) partly affected by plasma urea concentrations (Harmeyer and Martens, 1980). Above these concentrations, boundary layer effects with NH3 inhibit the urea entry into the digestive tract (Lapierre and Lobey, 2001). Urease activity is lower with increased NH3 concentrations and N intake (Marini et al., 2004). This inhibits the entry of urea into the digestive tract (Kennedy and Milligan, 1978). Thus high ammonia concentrations in the rumen result in a lower gut entry rate (Kennedy and Milligan, 1978; Bunting et al., 1989a). Urea, which flows from the blood into the rumen and enters the digestive tract, is hydrolyzed by bacterial urease to carbon dioxide (CO2) and ammonia (NH3) (figure 3.1). NH3 can be either reabsorbed into the blood or be used as N source for microbial protein synthesis or microbial growth (Sarraseca et al., 1998; Shingu et al., 2007). This latter process may provide a mechanism for the salvage of urea-N into bacterial protein which can be digested and yields amino acids to the animal when they are absorbed in the lower parts of the digestive tract. Thus, urea nitrogen incorporated in microbial protein and possibly absorbed in the gut gets a second chance for absorption and deposition/anabolic purposes. Therefore, urea recycling can be regarded as a mechanism with positive effects at the protein balance of ruminants. Gut entry location and gut entry rate (GER) The gut entry rate (GER) of urea is simply the amount of urea N recycled into the digestive tract. The amount of urea which entered the digestive tract that can be used for anabolic purposes depends e.g. on the gut entry location (Lapierre and Lobley, 2001). Urea appears to enter all parts of the digestive tract, including via saliva and pancreatic juice, but with different rates. The GER could be influenced by the concentration gradient of urea between the plasma and the fluids in the digestive tract (Harmeyer and Martens, 1980). The concentration gradient is again dependent on the activity of ureolytic bacteria and could therefore be influenced by diverse bacteria-influencing compounds in the feed. Also, the presence of carrier mediated, facilitative urea transport mechanisms have been reported in the ovine colon and rumen epithelia (Ritzhaupt et al., 1997). The carrier mediated, facilitative urea transporters in the ovine colon and rumen epithelia permit bi-directional flows (Ritz haupt et al., 1997), and thus may the total gut entry rate (GER) be underestimated if urea molecules are reabsorbed without being metabolized (Lapierre and Lobley, 2001). Post-stomach tissues can greatly influence the (GER) (up to 70%), but their contribution to potential anabolic salvage of N is not certain. The majority of conversions of urea into anabolic compounds occur in the fore-stomach, mainly the rumen (Kennedy and Milligan, 1980). As summarized by Lapierre and Lobley (2001), in sheep, the part of the total gut urea entry (GER) transferred to the rumen varies from 27 to 60% (Kennedy and Milligan, 1978) and 27 to 54% (Siddons et al., 1985) depending on type of diet. This proportion seems to increase when animals get high levels of rumen-degradable energy in feed (Lapierre and Lobley, 2001; Theuer et al., 2002). Also saliva contributes to the total urea entry into the rumen, depending on the type of diet ingested. E.g. this proportion varies extensively from 15 (Kennedy and Milligan, 1978) to almost 100% (Norton et al., 1978) in sheep. It has been found in growing beef steers that forage diets, e.g. alfalfa hay, result in higher proportions of saliva entering the gut (36% of GER) (Taniguchi et al., 1995) compared to high concentrate diets (17% of GER) (Guerino et al., 1991). Thus the fore-stomachs are important for the anabolic salvage of N, however, this depends on the type of feed ingested (and animal species). Small intestine Also the small intestine contributes to the anabolic salvage of N. It has been found in sheep that 37 and 48% of the total GER of urea entered the small intestine in case of grass silage and dried grass, respectively (Siddons et al., 1985). However, the quantities of anabolic N formed may by small, e.g. because ammonia production seems to exceed urea entry across the small intestine, although this depends on the type of feed ingested (Lapierre and Lobley, 2001). Hindgut Likely most microbial protein synthesized from urea that enters the hindgut is excreted. All the evidence so far would suggest that hindgut usage of urea involves only catabolic fates, at least in terms of amino acids supply to the animal (Lapierre and Lobley, 2001). Fate of urea that enters the digestive tract Urea that enters the gut by means of saliva or flowing through the gut wall can be used for anabolic purposes or is transformed into ammonia and returned to the liver (Lapierre and Lobley, 2001). Much of the NH3 in the GI tract is reabsorbed and used in the liver for the synthesis of glutamate and glutamine, and then a variety of other nitrogenous compounds (Bender, 2008). Urea-N that entered the gut contributed for 33% of the rumen ammonia flux in sheep offered dried grass, while this percentage was lower in case of grass silage (Siddons et al., 1985). Lapierre and Lobley (2001), based on several references, summarized that sheep, dairy cows and growing steers have a efficient reuse of N because urea-N atoms can return to the gut on more than one occasion. This increases the overall probability of appropriation towards an anabolic fate. This multiple-recycling process can result in improvements of 22 to 49% of GER used for anabolic purposes in both cattle and sheep (Lapierre and Lobley, 2001). A substantial proportion of urea that enters the digestive tract is returned to the body as ammonia in both sheep (32 to 52%; Sarreseca et al., 1998) and cattle (26 to 41%; Archibeque et al., 2001). This means that a large proportion of net ammonia absorption across the PDV is due to recycled N, rather than arising directly from ingested N. These anabolic and ca tabolic fates of urea then explain why net appearances of amino acid-N and ammonia across the PDV can equal or exceed apparent digestible-N (Lapierre and Lobley, 2001). The net result of all these N transactions is that the apparent conversion of digestible N into net absorbed amino acid N can be high, with individual values of 27 to 279% calculated for both cattle and sheep. These efficiencies are lower (24 to 58%) when other inputs are considered, mainly the urea-N inflow into the rumen. Apparent digestible N represents the net available N to the animal and thus the amino acid absorption cannot normally exceed this unless other N sources like amino acids obtained due to catabolism (released on a net basis during submaintenance intake) or urea recycling. N recycling via the digestive tract increases the opportunity for catabolism N to be reconverted to an anabolic product. This recycling can be considered analogous to the synthesis and breakdown of proteins within tissues, where th e dynamic flow maintains metabolic fluidity with minimum loss (see figure â⬠¦; Lapierre and Lobley, 2001). SUMMARIZED UREA RECYCLING KINETICS Thus, urea-N kinetics can, as an approximation, be considered as a mechanism, where hepatic synthesis is similar to digested N, with one-third lost via the kidneys into urine, while the remaining two-thirds is returned to the digestive tract. Half of this is then reconverted to anabolic N (mainly amino acids) that can be reabsorbed and used for productive purposes. Most of the remaining half of GER is reabsorbed as ammonia that is reconverted to urea and can be further re-partitioned between urinary loss and GER (see figureâ⬠¦). The process thus allows conversion of a catabolic products (urea-N) into anabolic forms, contains these for longer within the body, and provides the animal with increased opportunities to utilize products derived from dietary N (Lapierre and Lobley, 2001). Figureâ⬠¦ Urea recycling: values in circles represent the fraction of hepatic ureagenesis destined either for urinary output or to gut entry rate (GER); values in rectangles represent the fractions of gut entry rate lost in feces, returned as ammonia to the hepatic ornithine cycle or converted to anabolic products (mainly amino acid N). Thus, on average, 33% of hepatic urea-N flux is eliminated in urine while 67% enters the various sites of the digestive tract. Of this latter N, 10% is lost in feces, 40% is reabsorbed directly as ammonia, while the remaining 50% is reabsorbed as anabolic-N sources (mainly AAs). Data are simplified means for steers, dairy cows and sheep (from Archibeque et al., 2001; Sarraseca et al., 1998; summarized by Lapierre and Lobley, 2001) Efficiency of N utilization In both cattle and sheep, the inefficient use of intake-N is associated with large ammonia absorption representing on average 0.46 and 0.47 of N available from the lumen of the gut (digestible N plus urea-N entry across the PDV) (Lapierre and Lobley, 2001). As mentioned earlier, one strategy is to reduce the amount of N directed towards ammonia absorption and hepatic ureagenesis, but the situation is more complex than that. The target of reduction of ammonia absorption has to be integrated in a wider context where this decrease would result 1) from a smaller degradation of dietary N into the rumen or 2) from an increased utilization of rumen ammonia for microbial protein synthesis. Lowered N degradation can result from diet manipulation. Lapierre and Lobley (2001) summarized from several studies that cattle fed concentrate-based diets had decreased ammonia absorption, both in absolute amounts and relative to digested N, compared with forage rations. Increased utilization of N for bac terial synthesis can also be influenced by dietary manipulation, particularly provision of additional energy. From several studies, it can be concluded that supplements of rumen fermentable energy sources increase the transfer of urea into the rumen, and therefore the capture of dietary N and GER into anabolic products, mainly amino acids. However, there appear to be upper limits to the overall efficiency of the process (Lapierre and Lobley, 2001). The limited data available suggest that a maximum of 50 to 60% of dietary N, or 70 to 90% of apparently digested N, will be converted into amino acids released into the portal vein. Energy sources may also improve utilization of dietary and urea-N by less direct means, e.g. by energy-sparing effects within the cells of the gut tissues rather than alteration of rumen fermentation (Lapierre and Lobley, 2001). Intrarumen recycling Recycling of N can also occur within the rumen, due to the presence of proteolytic bacterial and protozoa. These graze and digest the rumen bacteria, increasing ammonia content and release within the rumen, and reducing microbial N outflow within the rumen because of increased recycling of bacteria (Lapierre and Lobley, 2001). Thus changes in the microbial population of the rumen can have substantial effect on anabolic N flow. Such modifications of the rumen microflora may contribute to the differences in N recycling and conversion to amino acids that occur between diets and animal species (Lapierre and Lobley, 2001). Amino acid supply In many circumstances, inefficiencies for conversion of feed N to animal protein may not be a feature of total amino acid supply, but rather depend more on the profile of absorbed amino acids. Hereby you can think of e.g. limiting essential amino acids. In short the definition of urea recycling is: the flow of urea from the blood into the digestive tract so that urea nitrogen salvage could happen. Figure â⬠¦ Use of [15N15N] urea and isotopomer analysis of urinary [15N15N], [14N15N] and [14N14N] urea to quantify flows and fates of urea that enters the digestive tract. Part of the infused [15N15N]urea enters the digestive tract were it can be excreted in the faeces or is hydrolyzed to [15N]ammonia. This latter is either used by the microbial population to synthesize bacterial proteins ([15N]) or it is absorbed directly as [15N]ammonia. [15N]ammonia is removed by the liver were [15N14N]urea is formed. The ratio of [14N15N]:[14N14N]urea in the urine reflects the proportion of urea flux that is converted to ammonia in the digestive tract and returned directly to the hepatic ornithine cycle (Lapierre and Lobley, 2001). The utilities of urea recycling Both ruminants and non-ruminants, including omnivores, have a mechanism in which urea produced by the liver can enter the intestinal tract and where it is used for microbial protein production or urea production. However, the amount of urea recycled in ruminants is in much larger proportions compared to non-ruminants, which emphasizes the importance of urea recycling in ruminants (Lapierre and Lobley, 2001). Next to reducing feed costs (due to the lower dietary N contents required), there are three important reasons to obtain a good and efficient urea recycling in ruminants (Huntington and Archibeque, 1999): Maximization of the microbial functioning in the rumen; Optimization of the amino acid supply to the host ruminant improvements of adaptation; Minimization of the negative effects of nitrogen excretion into the environment. Maximization of microbial functioning In ruminants, synthesis of urea by the liver can exceed apparent digestible N. This would result in a negative N balance (even at high intakes) if no salvage mechanism existed to recover some of this N (Lapierre and Lobley, 2001). Recycling of urea synthesized in the liver can provide a substantial contribution to available N for the gut. Lapierre and Lobley (2001) summarized that this can increase the digestible N inflow from 43 to 85% in growing steers, 50 to 60% in dairy cows and 86 to 130% in growing sheep. Moreover, in veal calves shifts the major origin of absorbable amino acids in the small intestine after weaning from milk protein to microbial protein (Obitsu and Taniguchi, 2009). With this, it is important to realize that a higher level of urea recycling results in a higher production of microbial protein. This protein source will be largely used for anabolic uses and performance which will result, on the long term, in improved production efficiency (Lapierre and Lobley, 200 1). What urea-N recycling does is to increase N transfers through the body to convert more of the N into anabolic form and thus acts as a conservation mechanism. Therefore, the combined inflows of dietary N and urea GER can be considered analogous to protein turnover within the body, where the anabolic and catabolic processes of synthesis and degradation greatly exceed inputs (intake) and outputs (oxidation and gain). This is believed to provide an overall plasticity to allow rapid response to any challenges or changes in metabolic status. Optimization of amino acid supply adaptation As a consequence of the salvage mechanism to recover some N, nitrogen and urea recycling in ruminants are important regarding the adaptation to different environmental (living) circumstances but mainly to nutritional conditions. Examples are periods of dietary protein deficiency or an asynchronous supply of carbohydrates and proteins (Reynolds and Kristensen, 2008). Ammonia and microbial protein produced in the gut and urea synthesized in the liver are major components in N-recycling transactions (Obitsu and Taniguchi, 2009). An increase in the total urea flux, caused by the return to the ornithine cycle from the gut entry, is considered to serve as a labile N pool in the whole body to permit metabolic plasticity under a variety of physiological (productive), environmental and nutritional conditions (Obitsu and Taniguchi, 2009; Lapierre and Lobley, 2001). Therefore, ruminant species have different characteristics of their urea recycling due to different living conditions varying from tropical conditions with poor quality feed to intensive systems in temperate/cold conditions with high quality feed. High ambient temperatures seem to increase urea production but reduce urea gut entry (Obitsu and Taniguchi, 2009). Minimization of N excretion into the environment Finally, a more efficient urea recycling in ruminants results in a less urea-N excretion in the urine. This is will minimize the negative effects of nitrogen excretion into the environment (Huntington and Archibeque, 1999).
Monday, January 20, 2020
Ernest Hemingway :: essays papers
Ernest Hemingway Ernest Hemingway uses symbolism to help the reader gain a better perspective of how the protagonist feels in his story. Symbolism occurs when the author uses one thing to represent another. This helps to give the reader a better idea of the situation or feeling in a given scene. There are several types of symbolism utilized by authors. One type is conventional symbolism. Conventional symbolism is common to the area where the story takes place. While another type is personal which simply is closely tied to the individual. Still a third type of symbolism is universal, which hold a widely understood meaning. As we examine "Hills Like White Elephants" we notice how Hemingway integrates both personal and conventional symbolism in order to help the reader relate to the situation. As the story begins the reader is thrust into the lives of two individuals who wait in a small bar for their train to come. The symbolism is evident as early as the description of the setting when the introduction says, "The hills across the valley of the Ebro were long and white. On this side there was no shade and no treesâ⬠¦". This opening statement describes the actual landscape and also describes the situation that the two characters face which is dismal and dark. The reader might possibly wonder about what the other side of the hill looks like. The opening sentence might also be used as conventional irony since the hills are local to the setting of the story. The opening description of the setting later goes onto say, "â⬠¦the station was between two lines of rails in the sun". This also relays the current situation of the protagonist as being stuck between to sides. The reader experiences personal symbolism as the story advances. While focusing on her decision, she looks at her life says, "That's all we do isn't it-look at things and try new drinks". In this reflection, she is mentioning how monotonous her and her boyfriend's lives are with no change and no responsibility. Apparently the boyfriend enjoys this way of life in that he is the one pushing her towards his way of thinking without openly appearing to push her. The editors express their feelings of the symbolism used by Hemingway in saying, "Clearly the child begun in the girl's womb is a 'white elephant'"(book Arp, 184).
Sunday, January 12, 2020
Celebrating the Piano
This finest wood made this stringed low keyed, quiet musical instrument in 1157 Continuously sings quiet flowing harmonies Monotone pianississimo, pianoissimo, piano and mezzo piano lullabyââ¬â¢s Keep sounding from the pianoââ¬â¢s vibrations. Flutes, saxophones and original pianos were used to create this harmonic based musical piece. The piano provided the ongoing harmonic sounds throughout the song. The overall tone was very simple, smooth and unaccented. The saxophone played lines four and five to highlight the action of the piano. The altos and tenors sang lines four and five adding more emphases on the pianos purpose. The sopranos sang the entire song. The flutes played the first three lines, to provide the introduction. Classical Musical Era; Play that funky music and make me dance with piano forte musical notes The strings are becoming more versatile through musical eras Play harmonic soft flowing lullabyââ¬â¢s for me The strings are taking us from the baroque to classical eras Still producing monotones, the musical sounds are altering my moods The harpsichord is taking us from one musical era into another Now adding more confusion and options to musicians The string dominated instrument is changing and creating musical history Dual musical instrument resulted from economic changes The string dominated musical instrument is requiring multitasking The 1750-1825 musical era developed The string dominated musical instrument is progressing through musical eras The harpsichord, now allowing the vibrations from the piano sounds to be heard by plucking strings, emphasized all even numbered lines. During the classical musical era, the bass played throughout the song, also providing the harmonic structure. An additional regular piano provided ongoing melody. To emphasize the variety and contrast, the violin interchanged with wind instruments, flutes, saxophones and xylophones. This musical piece used sopranos, since it was an opera. Romantic Era; Playing softly flowing harmonic sailing music In childrens darkened quiet room late at night Playing energetic, jazzy, upbeat, high and low notes While running through the water on a brightly lit sunny beach in mid daylight Quiet romantic monotone music piano music with lights down low Loud blaring music in nightclubs Comes from the piano progressing into a clavichord Playing dual notes or sounds simultaneously Various brass, or wind, instruments; trumpets, horns, trombone and tubaââ¬â¢s were used to bring out the obvious contrasts, and highlight the extreme tempos in this musical selection. Several different pianos were used, the classical piano, the clavichord and harpsichord in this piano concerto. The softer musical versions or the melodies were played on the lyrics accenting softness, lightness. The louder pianoââ¬â¢s, horns and trumpets accented the ââ¬Å"louderâ⬠lyrics, which played slower, bass notes. No singers were used for this musical selection. The focus was primarily on musical instrumentation. Modern Music; Play me a pop, rap, jazz, classical tune A ballad and a tempo Fom jazzy ragtime To Classical Chariots of Fire Play me a tune with lots of percussion Play me a tune with whole notes, quarter notes, half notes eighth and sixteenth notes Play it in 4/4 à 2/4 3/4 and 6/8 time Play the classic take five in 5/4 time This amazing piece of wood From the piano, harpsichord, clavichord to the organ Never fails to entertain in these modern times This was a full modern concert including various sheet music with mixture ofà time signatures and strings, percussions wind, electronic instruments. Tap dancers were used contributing their won percussion. Singers, sopranos, altos, tenors and bass singing voices were used, each given specific roles to show the versatility of the different versions of the piano. à à Tambourines, drums and clavichord were used to provide percussion on every line.à Belters were used everytime the purpose of the piano contrasted. There are no specific standards for modern music. It is whatever the musician wants to play. Originating in Paris, modern music can be primitivism, impressionism and expressionism, a combination of all historical musical eraââ¬â¢s.
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