The Common Periwinkle Profile

The common periwinkle (Littorina littorea), also known as the edible periwinkle, is a frequent sight along the shoreline in some areas. Have you ever seen these little snails on the rocks or in a tide pool? Despite the large numbers of periwinkles on the U.S. shoreline today, they are not a native species in North America but were introduced from western Europe. These snails are edible — would you eat a periwinkle? Description Common periwinkles are a type of marine snail. They have a shell that is smooth and brown to brownish-gray in coloration and up to about 1 inch long. The base of the shell is white. Periwinkles may live out of the water for several days and can survive in challenging conditions. Out of the water, they can stay moist by closing up their shell with a trapdoor-like structure called an operculum. Periwinkles are mollusks. Like other mollusks, they move around on their muscular foot, which is coated with mucus. These snails may leave a trail in the sand or mud as they move around. The shells of periwinkles may be inhabited by a variety of species and may be encrusted with coralline algae. Periwinkles have two tentacles that can be seen if you look closely at their front end. Juveniles have black bars on their tentacles. Classification Kingdom: AnimaliaPhylum: MolluscaClass: GastropodaSubclass: CaenogastropodaOrder: LittorinimorphaSuperorder: LittorinoideaFamily: LittorinidaeSubfamily: LittorininaeGenus: LittorinaSpecies: littorea    Habitat and Distribution Common periwinkles are native to western Europe. They were introduced to North American waters in the 1800s. They were brought over possibly as food or were transported across the Atlantic in the ballast water of ships. Ballast water is water taken in by a ship to make sure operating conditions are safe, such as when a ship discharges cargo and needs a certain amount of weight to keep the hull at the right water level. Now common periwinkles range along the eastern coast of the U.S. and Canada from Labrador to Maryland and are still found in western Europe. Common periwinkles live on rocky coastlines and in the intertidal zone, and on muddy or sandy bottoms. Feeding and Diet Common periwinkles are omnivores  that feed primarily on algae, including diatoms, but can feed on other small organic matter, such as barnacle larvae. They use their radula, which has tiny teeth, to scrape the algae off of rocks, a process which can eventually erode the rock. According to a University of Rhode Island article, the rocks on the coastline of Rhode Island used to be covered with green algae, but have been bare gray since periwinkles were introduced to the area. Reproduction Periwinkles have separate sexes (individuals are either male or female). Reproduction is sexual, and females lay eggs in capsules of about 2-9 eggs. These capsules are about 1mm in size. After floating in the ocean, the veliger hatches after a few days. The larvae settle on the shore after about six weeks. The lifespan of periwinkles is thought to be about 5 years. Conservation and Status In its non-native habitat (i.e., the U.S. and Canada), the common periwinkle is thought to have altered the ecosystem by competing with other species, and grazing on green algae, which has caused other algae species to become overabundant. These periwinkles can also host a disease (marine black spot disease) which can be transferred to fish and birds. References and Further Information Buckland-Nicks, J., et. al. 2013. The living community inside the common periwinkle, Littorina . Canadian Journal of Zoology. Accessed June 30, 2013.littoreaEncyclopedia of Life. Littorina . Accessed June 30, 2013.littoreaGlobal Invasive Species Database. Littorina littorea. Accessed June 30, 2013.Jackson, A. 2008. Littorina . Common periwinkle. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 01/07/2013]. Accessed June 30, 2013.littoreaReid, David G., Gofas, S. 2013. Littorina . Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?ptaxdetailsid140262. Accessed June 30, 2013.littorea (Linnaeus, 1758)University of Rhode Island. Common Periwinkle. Accessed June 30, 2013.

The Problem Of Local Police - 868 Words

Description of the Problem Local police are being overly co-opt by federal law enforcement agencies. They are directing too many resources toward protecting the nation’s borders and other federal duties. It is a belief held by some that local police are becoming too militaristic in nature by using military-style weapons, tactics, training, uniforms, and heavy equipment. This notion makes local police no longer a benefit for the community. A number of attacks on American soil have demonstrated this nation’s vulnerability to both foreign and domestic terrorist. The Federal Bureau of Investigations defines terrorism as the unlawful use of force against persons or property to intimidate or coerce a government or its population to further political or social objectives. Race, Trust, and Police Legitimacy According to Horowitz, research consistently shows that minorities are more likely than whites to view law enforcement with suspicion and distrust. Minorities frequently report that the police single them out unreasonably. They believe it is because of their race or ethnicity. How the public views law enforcement on the lawfulness and legitimacy of their duty are an important criterion for judging policing in society. Lawfulness means that the police follow and perform their duties with constitutional, statutory, and professional standards. Legitimacy is the public s willingness to recognize police authority within society. (Horowitz, 2007) The racial and ethnic minority’sShow MoreRelatedCommunity Policing and Problem Solving1135 Words   |  5 PagesCommunity Policing and Problem Solving Policing John K. Forrest II CJS/210 August 15, 2010 Travis Coldwell Community Policing and Problem Solving Policing When police departments and crime rates of the past are examined there are some apologist who believe that America would be in a better law enforcement situation provide the policies of the past we put back into use. With the public becoming more technologically advanced and criminal’s awareness of prosecution avoidance, communityRead MoreAfter The 9/11 Attack, Many Agencies DidnT Know What To1630 Words   |  7 Pagesorder for everything to go out smoothly federal agencies will need the help of local law enforcement because they will be the first responders on the crime scene when something bad happens. Local law enforcement usually have it concerns with preventing or solving crimes such as burglary, theft, robbery, and homicide crimes, these crimes usually have an impact on the local community, but when future terror threats local law enforcement will have to reorganize adapt to the policing strategies of theRead MoreIt Comes To Light That Police Departments Across Th e States1741 Words   |  7 Pageslight that police departments across the states play an important role in fighting and preventing terrorism. They are being trained to learn and investigate local terrorist threats throughout the United States, and to make sure the community is protected from such harm. In to do so police officers will have to extend they stay in the community and be involved in such activities and improve the community trust, another thing they will have to do is to build a partnership with other local businessesRead MoreFice Of Community Policing Essay1609 Words   |  7 Pagescommunity policing focuses on crime and social disorder through the delivery of police services that includes aspects of traditional law enforcement, as well as prevention, problem-solving, community engagement, and partnerships. The community policing model balances reactive responses to calls for service with proactive problem-solving centered on the causes of crime and disorder. Communi ty policing requires police and citizens to join together as partners in the course of both identifying and effectivelyRead MorePolice History Paper1117 Words   |  5 Pagesthey were in the 1800s. Peel established the Metropolitan Police when he served as Home Secretary of England. Since Sir Robert Peel introduced his principles of policing in the early 1800s, our country has continued to follow his ideas of effective policing. Community policing is based on Peels concept of prevention. According to one of Peel’s principals, the real key for policing is The police are the people and the people are the police. Peel believed that prevention of crime could be accomplishedRead MoreLaw Enforcement History: Historical Development of Police Agencies and Their Jurisdictions1017 Words   |  4 PagesThe Historical Development of Police Agencies and Their Jurisdictions: An Analysis Man is cruel and competitive. For these reasons, man often times wrongs others in society. And for this reason, it is necessary to have a law enforcement agency, whether local, state-based, or federal. In the absence of the rule of law, society would not be able to function, and man must make a pact that, in order to live and be protected within society, he must obey these laws. Police agencies often times serve asRead MoreThe Impact Of Terrorism On Economic Development And Reducing The Level Of Industrialization Essay1533 Words   |  7 Pagesin the America to refer to the police. Police officers play a significant role in the process of fighting terrorism. In order to realize the role of law enforcement officials, the government of the United States came up with a number of strategies which include: Initiation of Training Programs It involves the familiarization of terrorism-related aspects. The teaching helps the officers to recognize the strength of a danger thus find ways of overcoming them. The police officers are also introduced toRead MoreThe Eras of Policing Are Political, Reform and Community Problem Solving600 Words   |  3 PagesReform Era, and The Community Problem Solving Era. A lot has changed in the way that policing works over the years in the United States. During the Political Era the police departments were typically established and controlled by local government agencies. The Police being ran by the Local Government means that the State and Federal government did not interfere too much. Only well established families or local political groups would get the local elected positions. Police also did a lot more duringRead MoreLaw Enforcement Today Paper1056 Words   |  5 PagesISSUES OF POLICE DEPARTMENTS IN TODAY’S SOCIETY BY: HOLLY HANDLON February 20th, 2012 The issues that our police departments face in today’s society consist of corrupt police departments, publicity, operating expenses, and constant training to meet the guidelines set by court decisions. Corruption and brutality scandals have severely tarnished the public’s faith in the police. From the killings and brutalizing of citizens in New York City to the widespread corruption in the Los AngelesRead MoreWhy Hiring More Police Officers916 Words   |  4 Pagesseveral reasons why hiring more police officers does not reduce crime rates. First, if we increased our nation’s police force, the number of actual police officers per 10,000 citizens would continue to be insignificant because the police officer’s presence is already distributed very thin. Second, in spite of a large and noticeable police existence some criminals are not discouraged from committing crimes. Third, many crimes cannot be successfully stopped by police patrol because they are committed

Diffusion, Dialysis And Osmosis Lab free essay sample

We discovered that we were going to observe and understand the conditions under which diffusion, dialysis, and osmosis occur. Then we constructed models of diffusion, dialysis, and osmosis. We predicted that the direction of change would be from the membrane to the beaker. We understood how these processes affected the selectivity of the cell membrane. The second part of the lab was dealing with dialysis. In this part we studied starch and sodium chloride for dialysis activity. In Part A We hypothesized that NaCl existed in 1-3 and AgNO existed 2-4. In Part B We hypothesized that there will be more changes in the cell then outside the cell. In Part C We hypothesized that there will be a difference due to the different environments that are provide to help change the appearance of a molecule. Procedure A. Qualitative testing for sodium chloride and starch We got 6 clean test tubes and number them 1-6. We will write a custom essay sample on Diffusion, Dialysis And Osmosis Lab or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Test tubes 12 had 5ml of 10% sodium chloride (NaCl). Test tubes 34 had 5ml of starch. Test tubes 56 had 5ml of distilled water. We added 2-3 drops of silver nitrate (AgNO )to 1,3,5. We added 2-3 drops of iodine solution to 2,4,6. B. Dialysis of a starch/sodium chloride mixture Get one dialysis tube and tie one end. Fill the bag with 5ml of 10% Sodium chloride solution and 5ml of starch solution from Part A. then tie the tube and place it in a beaker of distilled water. Leave the tube for 30 minutes. Afterwards test for the presence of starch and sodium chloride. Then split the solution into to test tubes and 2-3 drops of iodine into one test tube and 2-3 drops of AgNO in the other test tube. C. Osmosis using dialysis tubing as a model of the cell membrane Obtain 5 beakers and label them 1-5. Fill beakers 1-4 halfway with distilled water. And beaker 5 with 30% sucrose halfway. Obtain 5 dialysis tubes that will be filled with 10ml of different solutions. Tube 1 has distilled water, Tube 2 has 10% sucrose, Tube 3 has 20% sucrose, Tube 4 has 30% sucrose, and Tube 5 has distilled water. Tie the tubes and weigh each of them before placing them in there respected beakers. Every 15 minutes weigh the tubes to record the change. There will be 5 tables for each beaker. Results A. TT1: yes NaCl; TT2: no AgNO; TT3: no NaCl; TT4: yes AgNO; TT5: no NaCl; TT6: no AgNO B. Test Tube 1Test Tube 2 Outside: no starch; Inside: yes starch; Outside: yes salt; Inside: yes salt C. #1 TIME 0 -9. 7 15 -9. 30 -9. 7 45 -9. 7 #2 TIME 0-9. 8 15-10. 3 30-10. 8 45-10. 9 #3 TIME 0-9. 8 15-10. 8 30-11. 5 45-11. 9 #4 TIME 0-10. 9 15-12. 4 30-13. 1 45-15. 7 #5 TIME 0-9. 5 15-8. 3 30-7. 5 45-6. 8 Conclusion In Part A we found that test tube 1 had NaCl and test tube 4 had AgNO . Test tubes 2,3,5,6 had no change and no presence of starch nor salt. Part A was the easiest part in this three part l ab. There weren’t any problems in this section which allows me to move on to the next section. This proving that our hypothesis was right because it meant that there was going to be sugar and salt present in the experiment. In Part B we found that outside test tube; salt existed and not sugar. But inside the test tubes both the starch and the salt existed in the two different tubes. In this part there weren’t any problems and we were successful in gathering the necessary results to move to the next section. This helping prove our hypothesis right because it meant that there would be more changes inside the cell than outside the cell. In Part C we found that Beaker 1 had no changes in weight. In Beaker 2 there were changes that ranged from 0-1. 1. In Beaker 3 there were changes that ranged from 0-2. 1. In Beaker 4 there were changes that ranged from 0-4. 8. In Beaker 5 there were changes that ranged from -2. 7-0. This is the results that my group gathered from another group that did well because our results were way off and inconsistent. So we were forced to use better results to find better explanations. We understood that the conditions under which osmosis is possible and to what degree it occurs. There were three different types of temperate environments. This helping prove our hypothesis right because it meant that different environments help change the appearance of a molecule.