Omis free essay sample

Information is perhaps the most important of all business resources, and the ability to manage it effectively on a global level is a essential organizational capability. Information systems are the tools that firms use to manage information, and it is critical for managers to understand how to use them. This course introduces you to key information systems concepts, Issues and questions that will help you to accomplish this. The focus of the course is managerial little prior knowledge of information systems is required, and you certainly wont be doing any programming!It is assumed that you already assess the basic computer skills needed to use various office suite products (word processing, spreadsheet, e-mail, etc. ), or will acquire these skills independently of this course. The objective of the course is to provide a basic knowledge set that will allow you to understand the most common information systems issues that exist in todays organizations, to ask critical questions, and p articipate in IT decision making. We will write a custom essay sample on Omis or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page P age 2 Organization of the Course Pedagogy This course relies on a diversity of teaching media, including lectures, readings, and case discussions.Nicolas discussions are important and quality lass participation is expected from each student. It is your responsibility to read the appropriate material before class. Unless prior arrangements have been made with the instructor, no late assignments will be accepted. Assigned Reading There is a readings package for this course that contains required articles and cases. As well we have an open source text: John Gallagher, Information Systems: A Managers Guide to Harnessing Technology, Flat World,Versions. 1, 2011. Go to this website to access the text: http:// You can read it online for free.If you pay $29 or thereabouts you can download an e-reader version or a PDF. A printed text is $40 and a color text is $60. We cover a large volume of material in this course. When preparing for class, you should review the overheads, carefully read the assigned articles and cases and try to identify what you believe are key points or issues. Always ask yourself the following question As a manager, what issues does this raise for me? Evaluation of Student Performance The course grading scheme for Masters level courses at Schulz uses a 9- value grade-point system.The possible course letter grades for a course (and the corresponding grade points awarded for each grade are: A+ 9 grade mints AAA B+ 6 B 5 BE C+ 3 C 2 CLC OF (Students are reminded that they must maintain a cumulative GAP of at least 4. 2 to remain in good standing and continue in the program, and a minimum of 4. 4 to qualify for their degree. Schulz grading guidelines mandate a section grade point average [GAP] of between 4. 7 and 6. 1 for core courses and a section GAP of between 5. 2 and 6. 2 for electives. Where instructors use numerical or percentage grades, Schulz grading policy does not require a preset translation of percentages into specific letter grades 13 Participation 20 % Individual Assignment 30 % Group Assignment 50% In class Five pages maximum, handed in at the beginning of session 4 Presentation 20%, session 6 Peer evaluation 5%, session 6 Final report 25%, No later than 1 day after final session Participation (20%) Good class participation by all class members is necessary in order to get the most out of the cases and readings.You are encouraged to take advantage of this gathering of your peers to improve your communication skills and obtain feedback on your views in a relatively low-risk environment. Attendance is not participation. Your attendance is expected for the full duration of the class. If oh miss more than two classes, you have failed the course. If you feel that you have to miss a class or any part of a class please inform the instructor before the class so that you will not be called upon in class and so that the instructor can advise you on how to keep up with the rest of the class.I expect that you will: a) Be prepared for class. B) Be on time for class. C) Keep me informed. Do not suffer in silence. Let the instructor know if you are having problems. Let it be known if you cannot attend class. With only six sessions, you do not want to miss anything. D) Come to class with a readable name card. This is important for monitoring your participation. Identify all your work completely with student number and name. Both of these actions will help the instructor to get to know you as an individual. In-class participation will be graded on quality not quantity.Timely and regular attendance, comments and questions that demonstrate knowledge of the topic and intellectual acuity can enhance your participation grade. Be respectful of others desire to participate, so be brief and relevant. Individual assignment (30%) The course includes an individual assignment, worth 30%. The total length Of he individual assignment is 5 pages maximum, including all materials, except an optional cover page, and a reference list (if required). I will provide details on this assignment in the first class. Group Assignment (50%) You will be placed into groups.Each group will be required to perform an analysis of a business problem that deals with IT issues. Details of the group assignment will be provided in session 1. The group assignment includes three deliverables: 1 . Final Report Final report (25%) each group will submit a final report due no later than 1 day following the final class session. The report will be no longer than 20 pages, including all components, except for a title page and references. The following sections are required: Executive Summary (1 page only), Introduction, Summary, and Conclusions. Other sections are up to you 14 2.Management presentation Management presentation (20%) -? each group will deliver a 10 minute presentation during the final class session. No extra time will be allowed. Maximum 10 slides. Please provide me with a copy of the presentation slides the evening before the final class session by 6 p. M. At the latest. 3. Peer valuation Peer evaluation (5%) you will be asked to evaluate the performance of your fellow group members. I will hand out a form for this in week 6. Academic Honesty Academic honesty is fundamental to the integrity of university education and degree programs.The Schulz School will investigate and will act to enforce academic honesty policies where apparent violations occur. Students should familiarize themselves with York Universitys policy on academic honesty. It is printed in full in your student handbook and can also viewed on-line on the Schulz website, clicking through as indicated: MBA/IAMB. Schulz website Programs Masters Degree Learn More Academic Policy While academic dishonesty can take many forms, there are several forms of which students should be highly aware because they are the ones that are most likely to occur in the context of a specific course. 1] Plagiarism. Plagiarism is the presentation of information, ideas, or analysis generated by other people as being your own. It includes direct quotations as well a substantive paraphrases where the course of that information or idea is not clearly identified to the reader. Students should be careful to present their written org in a way that makes it completely clear in each and every cases where a quotation, a paraphrase, or an analysis is based on the work of other people. (This includes information from all sources, including websites. ) [2] Cheating.Cheating is an attempt to gain an unfair advantage in an evaluation. Examples of such violations include (but are not limited to) consulting prohibited materials during an examination or copying from another student. [3] Failure to follow limitations on collaborative work with other students in preparing academic assignments. Each class differs in the mix of assignments and roof-versus-individual preparation that is allowed. The instructor will make clear the extent of collaboration among students that is acceptable among students on various pieces of assigned work. Students should abide by those limitations and, if they are unsure about whether a certain level or form of collaboration would be acceptable, to clarify that question with the instructor in advance. [4] Aiding and abetting. A student is guilty of violating academic honesty expectations if he/she acts in a way that enables another student to engage in academic dishonesty. If a student knows (or should reasonably expect) that an action would enable another student to cheat or plagiarism, that students action constitutes an academic honesty violation.Illustrative examples include making your exam paper easily visible to others in the same exam or providing your own working or finished documents for an individual assignment to another student (even if that other student said that he/she just wanted to get an idea of how to approach the assignment or to check whether they had done theirs correctly). [5] Use of academic work in more than one course. Generally, academic work done for every course is new org, done for that course only. If a student wishes to use some or all of the academic work done for an assigned task in one course in another course, the student must get explicit, prior permission from both instructors so that they agree that the scope and nature of the overlapping use of that work is such that it can fairly be counted toward both courses. 15 Schedule of Topics and Readings The following list of lecture topics and readings indicate the material to be read, reviewed and/or prepared for the various class sessions. If any changes in this schedule become necessary, notifications will be posted in the courseCOM, and where such changes need to be announced between class sessions, an email will be sent to students Lotus Notes email accounts, notifying them of the change. Date Topic(s) Session 1 Key question: What is an information system and why is it Feb. 27 important? IS Chi 1, Lecture: Introduction to management information systems and enterprise Chi 5 Chi technology management 10 Lecture: Technolog y fundamentals Reading: A conversation about information technology 1. In your experience, does this conversation ring true? 2. Why are many business managers frustrated with organizational IT? 3. Why are many IT managers frustrated with the business side? 4. What can be done to improve relations between the two sides? Activity: A group discussion of Open versus Closed systems models. Session 2 Key question: How can you use information systems to get the Mar 5 most out Of organizations? IS Chi 1 1 Lecture: Organizational information systems Enterprise systems Case: Business Intelligence Software at CISCO Activity: Information structures organizational effectiveness Session 3 How can you manage the balance between security and privacy, Mar 12 openness and access? IS Chi 6, Chi 12, Chi 13 Lecture: IS ethics, privacy, computer crime, and security Case: Checkpoint (A) 1 . What is your appraisal of Checkpoints business model? 2. How legitimate are the concerns voiced by the industry critics? 3. In Derek Smiths position, what internal changes, if any, would you make to address the issues discussed in the case? 4. In Derek Smiths position, what would you recommend to the U. S. Congress regarding regulation of the personal data industry? Discussion: Information security vs. privacy 6 Session 4 Key question: How can you use information systems for a Mar 19 sustainable competitive advantage?

President Trumans Fair Deal of 1949

President Trumans Fair Deal of 1949 The Fair Deal was an extensive list of proposals for social reform legislation suggested by U.S. President Harry S. Truman in his State of the Union address to Congress on January 20, 1949. The term has since come to be used to describe the overall domestic policy agenda of Truman’s presidency, from 1945 to 1953. Key Takeaways: The "Fair Deal" The â€Å"Fair Deal† was an aggressive agenda for social reform legislation proposed by President Harry Truman in January 1949.Truman had initially referred to this progressive domestic policy reform program as his â€Å"21-Points† plan after taking office in 1945.While Congress rejected many of Truman’s Fair Deal proposals, those that were enacted would pave the way for important social reform legislation in the future. In his State of the Union Address, President Truman told Congress that that, â€Å"Every segment of our population, and every individual, has a right to expect from his government a fair deal.† The â€Å"Fair Deal† set of social reforms Truman spoke of continued and built on the New Deal progressivism of President Franklin Roosevelt and would represent the last major attempt by the Executive Branch to create new federal social programs until President Lyndon Johnson proposed his Great Society program in 1964. Opposed by the â€Å"conservative coalition† that controlled Congress from 1939 to 1963, only a handful of Truman’s Fair Deal initiatives actually became law. A few of the major proposals that were debated, but voted down, included federal aid to education, the  creation of a Fair Employment Practices Commission, repeal of the Taft–Hartley Act limiting the power of labor unions, and the provision of universal health insurance. The conservative coalition was a group of Republicans and Democrats in Congress who generally opposed increasing the size and power of the federal bureaucracy. They also denounced labor unions and argued against most new social welfare programs. Despite the opposition of the conservatives, liberal lawmakers managed to win approval of some of the less controversial measures of the Fair Deal. History of the Fair Deal President Truman first gave notice that he would pursue a liberal domestic program as early as September 1945. In his first postwar address to Congress as president, Truman laid out his ambitious â€Å"21-Points† legislative program for economic development and expansion of social welfare. Truman’s 21-Points, several of which still resonate today, included: Increases to the coverage and amount of the unemployment compensation systemIncrease the coverage and amount of the minimum wageControl the cost of living in a peacetime economyEliminate federal agencies and regulations created during World War IIEnact laws ensure full employmentEnact a law making the Fair Employment Practice Committee permanentEnsure sound and fair industrial relationsRequire the U.S. Employment Service to provide jobs for former military personnelIncrease federal assistance to farmersEase restrictions on voluntary enlistment in the armed servicesEnact broad, comprehensive and non-discriminatory fair housing lawsEstablish a single federal agency dedicated to researchRevise the income tax systemEncourage the disposal through sale of surplus government propertyIncrease federal assistance for small businessesImprove federal assistance to war veteransEmphasize conservation and protection of natural in federal public works programsEncourage foreign post-war reconstructio n and settlements of Roosevelt’s Lend-Lease Act Increase wages of all federal government employeesPromote the sale of surplus wartime U.S. naval vesselsEnact laws to grow and retain stockpiles of materials essential to the future defense of the nation Expecting lawmakers to take the lead in drafting the bills necessary to implement his 21-Points, Truman did not send them to Congress. Focused at the time on dealing with rampant inflation, the transition to a peacetime economy, and the growing threat of Communism, Congress had little time for Truman’s social welfare reform initiatives. Despite the delays and opposition from the conservative Republican majority in Congress, Truman persisted, continuing to send them an ever-increasing number of proposals for progressive legislation. By 1948, the program that had begun as the 21-Points had come to be known as the â€Å"Fair Deal.†Ã‚   After his historically unexpected victory over Republican Thomas E. Dewey in the 1948 election, President Truman repeated his social reform proposals to Congress referring to them as the â€Å"Fair Deal.† Highlights of Truman’s Fair Deal Some of the major social reform initiatives of President Truman’s Fair Deal included: A national health insurance planFederal aid to educationAbolition of poll taxes and other practices intended to prevent racial minorities from votingA major tax cut for low-income workersExpanded Social Security coverageA farm assistance programExpansion of public housing programsA substantial increase in the minimum wageRepeal of the labor union-weakening Taft-Hartley ActA new TVA-style program to create public works projectsCreation of a federal Department of Welfare To pay for his Fair Deal programs while reducing the national debt, Truman also proposed a $4 billion tax increase. The Legacy of the Fair Deal Congress rejected most of Truman’s Fair Deal initiatives for two main reasons: Opposition from members of the majority-holding conservative coalition in Congress who viewed the plan as advancing President Roosevelt’s New Deal’s effort to achieve what they considered to be a â€Å"democratic socialist society.†In 1950, barely a year after Truman proposed the Fair Deal, the Korean War shifted the government’s priorities from domestic to military spending. Despite these roadblocks, Congress did approve a few or Truman’s Fair Deal initiatives. For example, the National Housing Act of 1949 funded a program removing crumbling slums in poverty-stricken areas and replacing them with 810,000 new federally rent-assisted public housing units. And in 1950, Congress nearly doubled the minimum wage, raising it from 40 cents per hour to 75 cents per hour, an all-time record 87.5% increase. While it enjoyed little legislative success, Truman’s Fair Deal was significant for many reasons, perhaps most notably its establishment of a demand for universal health insurance as a permanent part of the Democratic Party’s platform. President Lyndon Johnson credited the Fair Deal as being essential to the passage of his Great Society health care measures such as Medicare.

Westfarmers Curragh Pty Ltd Assignment Example | Topics and Well Written Essays - 1250 words

Westfarmers Curragh Pty Ltd - Assignment Example Curragh falls under the category of largest independent producer of coal mines and Curragh mission is to deliver and create sustained, outstanding growth for shareholders value and return by way of delivering quality products to the customers as per their requirements. The key mining products of Curragh includes hard coking coal, steam coal and PCI coal (Curragh, 2011). Advantage for Curragh to enter the Chinese coal market would be since China is the second largest importer of coal and it imports mostly from Australia and Indonesia making room for Curragh to enter China and export coal reserve. Several factors have contributed to China’s sudden entrance in the coal import sector such as environmental as well as safety consideration, transportation bottleneck, and economic factors along with concerns with respect to depleting coal reserve. Based on the above several factors it would wise to export coal to china Analysis of external environment External environment includes industry factor and the general environmental factors and starts with an analysis of the political factors, economic, social, technological factors, environmental and legal factors which are also referred to as PESTEL analysis. Thus if Westfarmers Curragh l wants to entry China it should analyze the external environment of China through PESTEL. ... Safety with coal production has been significant focus for the Chinese government and as result deaths per million tons of coal produced has decreased by 85% in between 2000 and 2009 (World Coal Association, 2011). China has been suffering from imbalance transportation which means coal needs to be transported through long distance through roads, railways and water bodies. Thus from the perspective of the Chinese government import of coal has been encouraged and can be regarded as a way to ease the deteriorating bottleneck of transportation in China. Curragh coal can benefit through this policy as it will get assistance from the Chinese government to export coal in China which in return will enhance the brand name and value of Westfarmers, it can avail to all the rights and regulation and enter the Chinese market. Economical Coal imports in China accounts for more than half of the global production and contributes to the economy of China. Over the years China has become the second lar gest coal reserve globally next to US. China is the largest energy consumer and the economy which has grown at an average rate of 10% is the key driver in consumption of energy both in China and also on international grounds. China GDP grew to 7.8% as estimated in the first half of 2012 (EIA, 2012). China is said to be the biggest producer of coal for the past 2000 years and is the third largest coal reserves with 114billion tones and in any economic environment would make it to the top coal producer. In an environment of rapid growth of economy, China production of coal has grown up drastically and in between 2000 and 2010 the coal production has tripled (World Coal Association, 2011). Exporting Curragh Coal in China will also boost

BUSINESS STRATEGY Essay Example | Topics and Well Written Essays - 1000 words - 1

BUSINESS STRATEGY - Essay Example Nokia was the most popular brand of mobile phones in these markets till the last decade, however with the advent of the Samsung group and its innovative products the market has been divided. Nokia faces a tough competition from the Samsung group especially in the mobile phone sector. In this analysis we try and compare the roles and responsibilities for strategy implementation in Nokia Inc and Samsung Group. The paper will try to identify and evaluate resources required to implement a strategy in the Nokia Inc. further it would also analyze whether the Nokia Inc is sufficiently equipped with resources so as to deal with the much required changes. The Samsung Group of companies is a Korean multinational organization with its headquarters in Seoul. It is one of the world’s largest mobile companies with annual revenue of 173.4 billion dollars. This organization has invested in a variety of businesses including heavy industries, ship industry and life insurance. However the mobile business remains its largest domain. â€Å"As a global leader we are at the forefront of change, anticipating today what our customers around the world will want tomorrow.† (Samsung Profile, 2009). Nokia being the market leader is the toughest competitor of the Samsung group in the mobile business. Nokia is a large organization with enough resources to spend on the reseach and development of the new technologies and innovations. At the same time Samsung group challenges Nokia Inc by bringing in phones which are attractive to the customers in terms of price and features. Nokia has wide established market and customers for mobile phones. It is a renowned firm for its user friendly products. Samsung on the other hand is a new dealer, as compared to Nokia, in the field of telecommunication. Still the firm has captured a considerable market and is providing tough competetion to the Nokia Inc. the strength of the Samsung group is that it adopts different strategies

Relationships between soldiers in The Thin Red Line (1998, Malick) Essay

Relationships between soldiers in The Thin Red Line (1998, Malick) - Essay Example This war movie consists of both cruelties and kindness. The first level of kindness that this takes place is with regards to the brotherly relations that are evident between the men of the company and platoon. On a second level, the relationships within the movie are related to the viewer with regards to the means by which father-son elements unfold also represent bright side of humanity. On the other side of spectrum we face tensions between people that result into conflicts in the movie. When seeking to understand these relationships within the context of the film, the following analysis will attempt to draw a level of focus upon the brother-brother, father-son, and exemplification of tensions between the men as they are exhibited by the actions that take place. As such, this particular analysis will seek to understand whether or not a familial level of relationships exist within the film, the type and definition of these familial relationships and some of the causal factors that h elp to encourage and develop these features. Firstly, with regards to the brother-brother relationships that are exhibited within the film, the viewer can see direct evidence of this to the type of behavior that is exhibited during their leave. Even though it may be assumed that the brotherly relations would most be exemplified during the combat scenes of the film, this is not necessarily the case. Rather, the dynamics of brotherly relations between the battle-weary men is most exhibited with regards to how the men spend their free time once they are on leave or before and after the combat. After weeks of stress and integrating with the deaths of their comrades within gruesome battles, the men settle into an uneasy, still stressful, rest that is only punctuated and made uniform by the level to which these men appreciate their own camaraderie and seek to make a communal sense of their current lives. The Narrator says the following about Witt’s realization of friendship:  "he feels the mysterious quality of deep, manly friendship which can exist between men who share the pain and death, the fear and sadness of combat—the happiness, too† (02:40). This of course helps to underscore the understanding of how the men involved within the film are defined by the conflict they are in. If such hardships did not exist within Guadalcanal, it is unlikely that the brotherly relationship exhibited during leave would have ever developed at all. Hardships bring people together, since they are fighting together for one cause against one evil enemy. Likewise, the father-son relationship that exists within the film is most adequately exposed by how Captain Staros interacts with the company commander. Captain Staros, a father figure for the men under his command, takes his role as guardian and protector of his men’s lives very seriously. Therefore, he takes full responsibility for all of the members of his platoon. Although his responsibility as an o fficer also includes implementing the orders of the officers above him, this primary motive to provide for the safety and wellbeing of the men under his command serves as something of a guiding precept by which Staros defines his role as captain. Staros right before the leave home has a warm and memorable talk with some members of his platoon. He says, â€Å"

Analytical Techniques for DNA Extraction

Analytical Techniques for DNA Extraction Development of DNA sensors for highly sensitive detection of sequence specific DNA has become crucial due to their extensive applications in clinical diagnosis, pathogen detection, gene expression studies, and environmental monitoring.ref Along with complementary base-pair hybridization between long oligonucleotide for DNA detection, several DNA sensors employ short oligonucleotide (à ¢Ã¢â‚¬ °Ã‚ ¤10 base pair) to this goal. Ref Easley and co-workers constructed the electrochemical proximity assay (ECPA) for highly sensitive and highly selective quantitative detection of protein, where target-induced DNA hybridization between 5, 7, or 10 complementary base system brings redox tag close to the sensor surface resulting direct electrochemical readout. To date, numerous analytical techniques have been established for DNA detection, such as electrochemistry, fluorescence, surface plasmon resonance, chemiluminiscence, quartz crystal microbalance and so on. Ref Among these methods, electrochemical DNA (E-DNA) sensors have attracted much attention owing to their reliability, simplicity, rapid response, low cost and portability, low sample consumption, ability to work in complex-multicomponent samples and remarkably high sensitivity and selectivity.ref The basic principle of E-DNA sensor is based on immobilization of single stranded DNA probe, a selective biological recognition element, on a sensor surface followed by incubation with sample containing the target biomolecules. When a target-induced molecular recognition event (hybridization) takes place the sensor translates that to a measurable electrochemical signal which is directly correlated to the target concentration. In recent years, numerous research groups have studied the perf ormance of these sensors by investigating the effect of immobilized probe structure and probe surface density, nature of the redox reporter used, target length, ionic strength of buffer and modifying the frequency of the square-wave voltammetry employed. ref Nevertheless, distance dependence of the redox tag relative to the electrode surface to achieve maximum signal has never been explored. As solid-phase hybridization is very distinct from that in solution-phase in terms of kinetics and thermodynamics, ref sensor performance may be sensitive to the location of the redox reporter because surface charge would likely alter the hybridization rate of negatively charged DNA which, in turn, alters the signaling properties of E-DNA sensors. Especially for short oligonucleotide (à ¢Ã¢â‚¬ °Ã‚ ¤10 base pair) hybridization near surface the effect may lead to very à ¢Ã¢â€š ¬Ã‚ ¦ due to their low binding energy which is not sufficient to overcomeà ¢Ã¢â€š ¬Ã‚ ¦. Here, we describe a detailed s tudy of the extent to which the location of the redox reporter can be varied to achieve maximum signal within shorter response time in effort to design efficient E-DNA sensors with improved sensitivity. Prior to this work, these electrochemical DNA (E-DNA) and electrochemical, aptamer based (E-AB) sensors have been reported against specific DNA and RNA sequences,2 proteins,3,4 small molecules,5-7 and inorganic ions.8,9 Because all of the sensing components in the E-DNA/EAB platform are covalently attached to the interrogating electrode, the approach requires neither exogenous reagents nor labeling of the target. Likewise, because their signaling is linked to specific, binding-induced changes in the dynamics of the probe DNA (rather than changes in adsorbed mass, charge, etc.), these sensors function well when challenged with complex, contaminant-ridden samples such as blood serum, soil extracts, and foodstuffs.5,7,9,10 These attributes render the E-DNA/E-AB platform an appealing approach for the specific detection of oligonucleotides and other targets that bind DNA or RNA.11-13 In the above methods, electrochemical biosensors are much popular because of their simple instrumentation setup, low sample and reagent consumption as well as high sensitivity and selectivity (Wenetal.,2012; Lu etal.,2012; Wenetal.,2011; Farjamietal.,2011; Xia etal.,2010; Xiang andLu, 2012; Pei etal.,2011; Farjamietal.,2013; Liu etal.,2013b). Electrochemical methods,1,11 being simple, portable and low-cost, are particularly attractive for DNA detection.12à ¢Ã‹â€ Ã¢â‚¬â„¢16 Electrochemical methods have been used extensively in DNA detection assays, as summarized in recent review articles.15,16 Among these protocols, the electrochemical biosensors have attracted particular attention in different fields owing to its small dimensions, easy operation, rapid response, low cost, high sensitivity and selectivity [10,11]. Among these techniques, the electrochemical techniques have received great interests owing to its superior characteristics of rapid response, low-cost, small-size, simple operation, and good selectivity [13-16]. Among these approaches, electrochemical methods have been shown to be superior over the other existing measurement systems,11 because electrochemical transduction possesses a potential allowing the development of rapid, simple, low-cost, and portable devices.12-14 As an alternative to conventional techniques, electrochemical DNA biosensors have attracted considerable interest owing to their intrinsic advantages, including good portability, fast response, and remarkably high sensitivity (Sun etal.,2010). More importantly, a number of DNA biosensors have been developed and extensively applied for the determination of biomarkers (Huang etal.,2014). Microfabrication technology has enabled the development of electrochemical DNA biosensors with the capacity for sensitive and sequence-specific detection of nucleic acids.1-5 The ability of electrochemical sensors to directly identify nucleic acids in complex mixtures is a significant advantage over approaches such as polymerase chain reaction (PCR) that require target purification and amplification. Electrochemical DNA sensors are reliable, fast, simple, and cost- effective devices that convert the hybridization occurring on an electrode surface into an electrical signal by means of direct or indirect methods. the electrochemical DNA (E-DNA) sensor is one of them. This sensor platform, the electrochemical equivalent of optical molecular beacons, exhibits notable sensitivity, specificity and operational convenience whilst also being fully electronic, reusable and able to work in complex, contaminant-rich samples [4-6]. Compared with other transducers, electrochemical ones received particular interest due to a rapid detection and great sensitivity. Combining the characteristics of DNA probes with the capacity of direct and label-free electrochemical detection represents an attractive solution in many different fields of application, such as rapid monitoring of pollutant agents or metals in the environment, investigation and evaluation of DNA-drug interaction mechanisms, detection of DNA base damage in clinical diagnosis, or detection of specific DNA sequences in human, viral, and bacterial nucleic acids [2-8]. The determination using electrochemical biosensor methods has attracted much interest because of their simple instrumentation, high specificity, sensitivity, rapid, and is inexpensive with potential for applications in molecular sensing devices. Amongst the electrochemical transducers, carbon electrodes such as glassy carbon, carbon fibre, graphite, or carbon black exhibit several unique properties. Recent engineering advances have enabled the development of electrochemical DNA biosensors with molecular diagnostic capabilities (2, 8, 18, 33, 47). Electrochemical DNA biosensors offer several advantages compared to alternative molecular detection approaches, including the ability to analyze complex body fluids, high sensitivity, compatibility with microfabrication technology, a low power requirement, and compact instrumentation compatible with portable devices (18, 48). Electrochemical DNA sensors consist of a recognition layer containing oligonucleotide probes and an electrochemical signal transducer. A well-established electrochemical DNA sensor strategy involves sandwich hybridization of target nucleic acids by capture and detector probes (5, 7, 46, 50). First reported in 2003, electrochemical DNA (E-DNA) biosensors are reagentless, single-step sensors comprised of a redox-reporter-modified nucleic acid probe attached to an interrogating electrode.1 Originally used for the detection of DNA2à ¢Ã‹â€ Ã¢â‚¬â„¢9 and RNA10 targets, the platform has since been expanded to the detection of a wide range of small molecules,11,12 inorganic ions,13,14 and proteins,12,15à ¢Ã‹â€ Ã¢â‚¬â„¢17 including antibodies,18,19 via the introduction of aptamers and nucleic-acid-small molecule and nucleic-acid-peptide conjugates as recognition elements (reviewed in refs 20 and 21). Irrespective of their specific target, all of these sensors are predicated on a common mechanism: binding alters the efficiency with which the attached redox reporter approaches the electrode due to either the steric bulk of the target or the changes in the conformation of the probe.1,12,18 Given this mechanism, these sensors are quantitative, single-step (washfree), and selective enough to perform well even in complex clinical samples.12,15 They are likewise supported on micrometer- scale electrodes22 and require only inexpensive, handheld driving electronics (analogous to the home glucose meter23), suggesting they are well suited to applications at the point-of-care. Among these, the electrochemical detection of DNA hybridization appears promising due to its rapid response time, low cost, and suitability for mass production.11,12 The E-DNA sensor,13-16 which is the electrochemical equivalent of an optical molecular beacon,17-20 appears to be a particularly promising approach to oligonucleotide detection because it is rapid, reagentless, and operationally convenient.21,22 The E-DNA sensor is comprised of a redox-modified stemloop probe that is immobilized on the surface of a gold electrode via self-assembled monolayer chemistry. In the absence of a target, the stem-loop holds the redox moiety in proximity to the electrode, producing a large Faradic current. Upon target hybridization, the stem is broken and the redox moiety moves away from the electrode surface. This produces a readily measurable reduction in current that can be related to the presence and concentration of the target sequence. Both E-DNA sensors13-16 and related sensors based on th e binding-induced folding of DNA aptamers23-28 have been extensively studied in recent years. Nevertheless, key issues in their fabrication and use have not yet been explored in detail. Electrochemical biosensors, combining the sensitivity of electroanalytical methods with the inherent bio-selectivity of the biological component, have found extensive application in diverse fields because of their high sensitivity with relatively simple and low-cost measurement systems.1 For example, by assembling artful target-responsive DNA architectures on the electrode surface, a series of electrochemical bioanalysis methods have been proposed for the sensing of specific biomarkers, such as DNA and proteins.2-5 The typical sensing schemes of these designs involve the immobilization of an efficient probe on the electrode surface, incubation with target biomolecules, and measurement of the output electrochemical signal.6,7 A wide variety of nanomaterials including metal nanoparticles, oxide nanoparticles, quantum dots, carbon nanotubes, graphene and even hybrid nanomaterials have found attractive application in electrochemical biosensing, such as detection of DNA, proteins and pathogens and the design of biological nanodevices (bacteria/cells).14,15 Electrochemical transducers offer broad opportunities in DNA sensor design due to simple experiment protocols, inexpensive and mostly commercially available equipment. Among various detection methods, the electrochemical approach attracted much attention due to its rapidness, low cost, high sensitivity and compatibility with portability [10,11]. The E-DNA sensor [12,13], an electrochemical method derived from the optical molecular beacon[14,15], is particularly promising because it is reagentlessness andoperation convenience. In brief, the E-DNA sensor is composed of a redox-modified hairpin-like stem-loop DNA probe that is immobilized on the electrode surface. Without a target, the stem-loop structure holds the redox probe close to the electrode surface, pro-ducing a large current. Upon hybridization with a target, the stem is opened and the redox label moves away from the electrode surface and the current is decreased. This current change is directly related to the target DNA concentration. Many different versions of the E-DNA sensor have been reported to date [7-9]. A popular construct of this type of sensors is a folding-based E-DNA sensor comprised of a redox-labeled DNA stem-loop probe covalently attached to a gold disk electrode. In the absence of a target, the stem-loop conformation holds the redox label in close proximity to the electrode, facilitating electron transfer. In the presence of and binding to a complementary DNA target, hybridization forces the redox tag farther from the electrode, impeding electron transfer and producing an observable reduction in redox current [4-6]. In this approach, a single-stranded DNA (ssDNA) probe is immobilized on a surface and exposed to a sample containing the specific complementary target sequence, which is captured by forming a double-stranded DNA(dsDNA) molecule. This recognition event (hybridization) is then transduced into a readable signal. In this strategy, the target is anchored to the sensor surface by the capture probe and detected by hybridization with a detector probe linked to a reporter function. Detector probes coupled to oxidoreductase reporter enzymes allow amperometric detection of redox signals by the sensor electrodes (28, 34). When a fixed potential is applied between the working and reference electrodes, enzyme-catalyzed redox activity is detected as a measurable electrical current (11, 16, 27). The current amplitude is a direct reflection of the number of target-probe-reporter enzyme complexes anchored to the sensor surface. Because the initial step in the electrochemical detection strategy is nucleic acid hybridization rather than enzyme-based target amplification, electrochemical sensors are able to directly detect target nucleic acids in clinical specimens, an advantage over nucleic acid amplification techniques, such as PCR. Electrochemical methods are typically inexpensive and rapid methods that allow distinct analytes to be detected in a highly sensitive and selective manner [22-25]. Although electrochemical DNA sensors exploit a range of distinct chemistries, they all take advantage of the nanoscale interactions among the target present in solution, the recognition layer, and the solid electrode surface. This has led to the development of simple signal transducers for the electrochemical detection of DNA hybridization by using an inexpensive analyzer. DNA hybridization can be detected electrochemically by using various strategies that exploit the electrochemistry of the redox reaction of reporters [26] and enzymes immobilized onto an electrode surface [27], direct or catalytic oxidation of DNA bases [28-31], electrochemistry of nanoparticles [32-35], conducting polymers (CPs) [35-37], and quantum dots [38]. E-DNA sensors, the electrochemical analog of optical molecular beacons [e.g.,1-4], are based on the hybridization-induced folding of an electrode-bound, redox-tagged DNA probe. In their original implementation, the concentration of a target oligonucleotide is recorded when it hybridizes to a stem-loop DNA probe, leading to the formation of a rigid, double stranded duplex that sequesters the redox tag from the interrogating electrode [1]. Follow-on E-DNA architectures have dispensed with the stem-loop probe in favor of linear probes, leading to improved binding thermodynamics and, thus, improved gain [5], as well as strand-invasion, hairpin and pseudoknot probes producing signal-on sensors [6-8]. Because E-DNA sensors are reagentless, electronic (electrochemical) and highly selective (they perform well even when challenged directly in complex, multicomponent samples such as blood serum or soil) [e.g., 9], E-DNA sensors appear to be a promising and appealing approach for the sequence-s pecific detection of DNA and RNA [see, e.g., 10,11]. E-DNA signaling arises due to hybridization-linked changes in the rate, and thus efficiency, with which the redox moiety collides with the electrode and transfers electrons. To design efficient DNA-electrochemical biosensors, it is essential to know the structure and to understand the electrochemical characteristics of DNA molecules. Motivated by the potential advantages of the E-DNA sensing platform, numerous research groups have explored their fabrication and optimization over the past decade. Specifically, efforts have been made to improve the platforms signal gain (change in signal upon the addition of saturating target) by optimizing the frequency of the square-wave potential rampemployed,11 the density with which the target-recognizing probes packed onto the electrode,11,24 probe structure,25 the redox reporter employed,26 and the nature of the monolayer coating the electrode.25 Contributing to these studies, we describe here a more comprehensive study of the extent to which the square-wave voltammetric approach itself can be optimized to achieve maximum signal gain. Specifically, we have investigated the effect of varying the square-wave frequency, amplitude, and potential step-size on the gain of E-DNA sensors, evaluating each parameter as a function of the others as well as of the structure of the E-DNA probe, its packing density, the nature of its redox-reporter, and the monolayer chemistry used to coat the sensing electrode. E-DNA sensors are a reagentless, electrochemical oligonucleotide sensing platform based on a redox-tag modified, electrode-bound probe DNA. Because E-DNA signaling is linked to hybridization-linked changes in the dynamics of this probe, sensor performance is likely dependent on the nature of the self-assembled monolayer coating the electrode. We have investigated this question by characterizing the gain, specificity, response time and shelf-life of E-DNA sensors fabricated using a range of co-adsorbates, including both charged and neutral alkane thiols. The signaling mechanism of E-DNA sensors is linked to a bindingspecific change in the flexibility of the redox-tagged probe; upon hybridization, the relatively rigid target/probe duplex hampers the collision of the electrochemical tag thus decreasing the observable amperometric signal [5,12]. This, in turn, suggests that E-DNA signaling may be sensitive to changes in surface chemistry which, due to surface charge and steric bulk effects, would likely alter the dynamics of a negatively charged DNA probe. However, despite rapid growth in the E-DNA literature [reviewed in 13] the extent to which surface chemistry affects E-DNA signaling has not been established; all previous E-DNA sensors were fabricated using hydroxyl-terminated alkane thiol self-assembled monolayers (SAMs) [e.g.,1,3,5,7,9]. Here we address this question and describe a study of E-DNA sensors fabricated using co-adsorbates of various lengths and charges in an effort to further optimize E-DNA performance. For example, while it is likely that the signaling properties of these sensors depend sensitively on the density of immobilized probe DNA molecules on the sensor surface (measured in molecules of probe per square centimeter) [see, e.g., refs 5 and 29-36], no systematic study of this effect has been reported. Similarly, while it appears that the size of the target and the location of the recognition element within the target sequence affect signal suppression,24 this effect, too, has seen relatively little study. Here we detail the effects of probe surface density, target length, and other aspects of molecular crowding on the signaling properties, specificity, and response time of the E-DNA sensor. However, the sensitivity is one of the most important limiting factors for the development of electrochemical DNA biosensors.

Crime and Punishment Summary Essay -- essays research papers

One July day in St. Petersburg, a poor young man slips out of his apartment and goes out. He is Rodion Romanych Raskolnikov, a former student, and he is preoccupied with something. He arrives at the apartment of Alyona Ivanovna, a pawnbroker, where he is attempting a trial of the unknown deed obsessing him. He has pawned something to this woman a month before, and now pawns an old watch for much less than he had hoped to get. As the woman gets her money, he watches and listens very carefully, storing up details in his memory. He leaves after vaguely mentioning that he may come back soon with another pledge. Tormented, he wanders down the street, mentally at war with himself. He happens upon a tavern, where he stops to eat and drink something, and feels better after doing so. There, he meets Semyon Zakharovich Marmeladov, a retired official and a drunkard. Marmeladov pours out his life story to Raskolnikov, telling about his consumptive wife Katerina Ivanovna, his three small children, and his oldest daughter Sofya (Sonya), who has had to prostitute herself to earn money for the family. Marmeladov himself had recently acquired a position, but almost immediately lost it through his alcoholism. He has been away from home for five days, having stolen his salary money and spent it all on drink. Marmeladov asks Raskolnikov to take him home. Rodion does so, and witnesses how Katerina Ivanovna falls on her husband and drags him about by his hair. She kicks Raskolnikov out, assuming him to be a drinking partner of her husband's. As he leaves, he places a handful of change on their windowsill unnoticed. Outside, he regrets this action, but knows he cannot go back to get the money. The next day, he awakens feeling unrested. Nastasya, the landlady's servant, comes in with some tea for him, as well as leftovers from the previous day's meal (since he is behind on his rent, the landlady has stopped sending his dinner up to him). She also tells him that he has received a letter. Agitated, he sends her to get it, and orders her out of the room so he can read it. The letter is from his mother, Pulcheria Alexandrovna, and mostly concerns his sister Avdotya Romanovna, or Dunya. Dunya had been working as a governess in the house of the Svidrigailov family, but the husband's unfortunate attraction to her led the wife to kick Dunya out on the assumption that the girl had ini... ...ainder of the day wandering about and settling his affairs, and shoots himself the next morning. Later that day, Rodya goes to see his mother for the last time before turning himself in. He then hurries home, where he finds Dunya waiting for him. He takes leave of her and goes to Sonya. She gives him a cross. He rushes out rudely, not even saying goodbye to her, impatient to get it over with, even though he can't understand why he should go, because he still does not see his act as a crime. He goes to the station, with Sonya following him. He finds out that Svidrigailov is dead, and, stunned, leaves without confessing; but Sonya is waiting for him, and he goes back upstairs and confesses. Rodya is exiled to Siberia, where Sonya follows him. Dunya marries Razumikhin. Pulcheria Alexandrovna dies. Sonya writes to the Razumikhins about Rodya. He is unsociable and hated by his fellow prisoners. He falls ill. At the end of his illness, Sonya herself is ill, and he misses her. When she recovers, she goes to him, and he at last repents truly, falling at her feet and weeping. Having finally recognized his sin, he is resurrected†¹able to love Sonya and look forward to his life with her.