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Section II Project (Submission required)

Section II Project (Submission required)

Purpose of this project is to exercise the concepts learned in this chapter. It is not the purpose of this project to create realistic services and applications. We will create more realistic services and applications in the subsequent projects. In this project, you can use a console application or a simple GUI application to implement the user interface to your program. You do not need to create Web applications.

Description: Consider that you are creating an e-business: a book distribution system that involves bookstores and publishers. The system consists of multiple bookstores (clients) and multiple publishers (servers). The bookstores can buy in quantity of books from the publishers with lower prices. The required architecture and the major components of the system are shown in the diagram below.

 

 

 

 

In this project, you will implement both clients and servers in one system in multithreading. You will further implement such systems in distributed web client and server systems in the following projects.

An Operation Scenario of the book distribution system is outlined as follows:

(1) A Publisher uses a pricing model to calculate dynamically the book price for the bookstores. If the new price is lower than the previous price, it emits a (promotional) event and calls the event handlers in the bookstores that have subscribed to the event.

 

(2) A BookStore evaluates the price, generates an OrderObject (consisting of multiple values), and sends the order to the Encoder to convert the order object into a plain string.

 

(3) The Encoder converts the object into a string.

 

(4) The Encoder sends the encoded string back to the caller.

 

(5) The BookStore sends the encoded string to one of the free cells in the MultiCellBuffer.

 

(6) The Publisher receives the encoded string from the MultiCellBuffer and sends the string to the Decoder for decoding.

 

(7) The Decoder sends the OrderObject to the Publisher. The decoded object must contain the same values generated by the BookStore.

 

(8) The Publisher creates a new thread, an OrderProcessingThread, to process the order;

 

(9) The OrderProcessingThread processes the order, e.g., checks the credit card number and calculates the total amount.

 

(10) The OrderProcessingThread sends a confirmation to the bookstore and prints the order (on screen).

 

Note, the encoder and decoder here do not perform encryption and decryption tasks.

Components in the diagram are explained in details as follows, with their grading scores (points) allocation, Components 1, 2, 3, 4, and 5 belong to Assignment 3, and the rest of the components belong to Assignment 4. You will submit both assignments together as a project. We will enter the scores under assignments 1 and 2, for the purpose of score management.

 

Assignment 3 Tasks

  1. Publisher1 through PublisherK* are the objects of a class on the server side: Each object has a method to be started as a thread by the Main method and will perform a number of functions. It uses a PricingModel to determine the book prices. It defines a price-cut event that can emit an event and call the event handlers in the BookStore if there is a price-cut according to the PricingModel. It receives the orders (in a string) from the MultiCellBuffer. It calls the Decoder to convert the string into the order object. For each order, you must start a new thread (resulting in multiple threads for processing multiple orders) from OrderProcessing class (or method) to process the order based on the current price. There is a counter p in the Publisher. After p (e.g., p = 20) price cuts have been made, a Publisher thread will terminate. The bookstores do not have to make an order after each price cut. [15 points]

*Note 1: For the individual project, the number of publishers K = 1. For a group project (both two-member and three-member group), K = 2 if you have a 2-member team, and K = 3 if you have a 3-member team.

 

  1. PricingModel: It can be a class or a method in the Publisher class. It decides the price of books, which must be between 50 and 200. It can increase or decrease the price. You must define a mathematical model. The model can be a simple random function for individual projects. However, for the group projects, a more complex model must be developed, where the price must be a function with multiple parameters, such as the available number of the books and the number of orders received within a given time period. In other words, the function must take the amount of orders as input. You can use a hard-coded table of the prices, for example, in each weekday. You must make sure that your model will allow the price to go up some times and go down other times within your iterations of testing. [5 points]

 

  1. OrderProcessing is a class or a method in a class on the server’s side. Whenever an order needs to be processed, a new thread is instantiated from this class (or method) to process the order. It will check the validity of the credit card number. If you are doing an individual project or a two-member group project, you can define your credit card format, for example, the credit card number from the bookstores must be a number registered to the Publisher, or a number between two given numbers (e.g., between 5000 and 7000). For the three-member group project, a bank service must be created. Each OrderProcessing thread will calculate the total amount of charge, e.g., unitPrice*NoOfBooks + Tax + LocationCharge. For the group (two and three members) projects, a confirmation must be sent back to the bookstore when an order is completed. You can implement the confirmation in different ways. For example, you can use another buffer for the confirmation, where you can use a buffer cell for each thread, so that you do not have to consider the conflict among the threads. However, you still need to coordinate the write and read between the producer and the consumer. [10 points]

 

  1. BookStore1 through BookStoreN, You can set N = 5 in your implementation. Each bookstore is a thread instantiated from the same class (or the same method in a class). The bookstore’s actions are event-driven. Each bookstore contains a callback method (event handler) for the Publisher to call when a price-cut event occurs. The bookstore will calculate the number of books to order, for example, based on the need and the difference between the previous price and the current price. The thread will terminate after the Publisher thread has terminated. Each order is an OrderClass object. The object is sent to the Encoder for encoding. The encoded string is sent back to the bookstore. Then, the bookstore will send the order in string format to the MultiCellBuffer. For group project, before sending the order to the MultiCellBuffer, a time stamp must be saved. When the confirmation of order completion is received, the time of the order will be calculated and saved (or printed). [10 points]

 

The following components will be counted as assignment 3 tasks.

 

  1. OrderClass is a class that contains at least the following private data members:

 senderId: the identity of the sender, you can use thread name or thread id.

 cardNo: an integer that represents a credit card number.

 receiverID: the identity of the receiver, you can use thread name or a unique name defined for a publisher. If you are doing an individual project, you do not need this field.

 amount: an integer that represents the number of books to order.

 unit price: a double that represents the unit price of the book received from the publisher.

 

You must use public methods to set and get the private data members. You must decide if these methods need to be synchronized. The instances created from this class are of the OrderObject. [10 points]

 

Assignment 4 Tasks

 

  1. MultiCellBuffer class is used for the communication between the bookstores (clients) and the publishers (servers): This class has n data cells (for individual project, n = 2 and for group project, n = 3). The number of cells available must be less than (<) the max number of bookstores in your experiment. To write data into and to read data from one of the available cells, setOneCell and getOneCell methods can be defined. You must use a semaphore of value n to manage the availability of the cells. You must use an additional lock mechanism to provide read or write permissions for a cell. You cannot use a queue for the buffer, which is a different data structure. The semaphore allows a bookstore to see the availability of the cells, while the lock mechanism allows the agent to gain the right to write into one of the buffer cells. The Publisher can read buffer cells at the same time. Synchronization/monitor is required for read/write and write/write overlap. [20 points]

 

  1. Encoder is a class or a method in a class: The Encoder will convert an OrderObject into a string. You can choose any way to encode the values into a string, as long as you can decode the string back to the original order object. [10 points] Page 5 of 7

 

  1. Decoder is a class or a method in a class: The Decoder will convert the encoded string back into the OrderObject. Note: encoder and decoder here DO NOT perform encryption and decryption. [10 points]

 

  1. Bank service is a class. This question is for the three-member group projects only. It allows the bookstore to apply for a credit card number. The bookstore will use this number to purchase books from the publishers. The publishers will send the credit card number and the amount to the bank. The bank charges the account and returns the message “valid” if the account exists and the funds are sufficient for the purchase, otherwise, it returns “not valid”. When a publisher sends the credit card number and the amount to the bank, it will call the encryption service in the ASU repository to encrypt the credit card numbers in a string. If you use the .svc service, you must use “Add Service Reference”. If you use the .asmx service, you must use “Add Web Reference”. The recommendation is to use the .svc service, as it is the new standard. On the other hand, the bank will call the ASU decryption service to decrypt the number before comparing with the valid credit card numbers. The Bank class must also allow the account holder to deposit funds into the account. [20 points]

 

  1. Main: The Main thread will perform necessary preparation, create the buffer classes, instantiate the objects, create threads, and start threads. [10 points]

 

Additional Tasks for group projects

Two-member Teams: If you are doing the project as a group of two members, you are required to complete the following additional tasks:

[1] You must implement multiple suppliers (publishers) with K = 2. You must deal with all the issues that are incurred because of the increase in the number of suppliers.

[2] You must develop a more complex price model.

[3] The supplier must send a confirmation back to the bookstore when an order is completed.

[4] The buffer size (number of cells in the buffer) is 3, instead of 2.

In this option, one member must write the code of the bookstores and the main program. The other member must write the code of the supplier. The two members must jointly write the code for the buffer class.

 

Three-member Teams: If you are doing the project as a group of three members, you are required to complete all the additional tasks for the two-member group projects and the following additional tasks:

[1] You must implement multiple suppliers (publishers) with K = 3. You must deal with all the issues that are incurred because of the increase in the number of suppliers.

[5] If you have a three-member team, you must also define the bank service. The third member must implement the Bank class and share some other tasks in the assignment.

For three member team, there are totally 70 points in Assignment 4 of the project. The 70 points will be scaled to 50 points proportionally. For example, 70 à 50, 60 à 43, and 50 à 36.

 

Notes:

  1. It is the purpose of this course to enforce the knowledge of C# (Visual Studio), as we have multiple courses in our program that use Java. We encourage you to use C#. However, we allow the use of Java (on NetBeans) in this assignment. You must indicate the environment (e.g., VS 2015 or 2017 or NetBeans) that you use, so that the TA can use the same environment to grade the project. We taught multithreading in both Java and C#. However, we did not teach event-driven programming in Java. If you choose to do the project in Java, you need to study this part on your own. I suggest that you do the project in Java only if you already know how to program events. The event handling in Java is not as easy as in C# for this project, and you need to take extra effort to implement the required functions.

 

  1. You must follow what is defined in the assignment/project document. You have flexibility to choose your implementation details if they are not explicitly specified in the document. If you are not sure on any issue, ask the instructor or the TA by posting the question in the discussion board.
  2. The program and each component of the program must be well commented.
  3. You can choose to do this project as an individual project or a group project. I encourage you to do as a group project. Projects 3 and 5 will be required group projects and thus, you need to build a team anyway. The team building process is for assignments 3 and 5. The group used in assignment 2 does not have to be the same group for assignments 3 and 5. However, the group for assignment 3 and 5 must be the same, as the project in assignment 5 will be based on assignment 3.
  4. Project 3 will be partly a team project. If you have formed a team in this project, you can use the same team for the project 3. Of course, you can also use a different team for the project 3.

 

 

 

 

Submission Requirement

All submissions must be electronically submitted to the assignment folder where you downloaded the assignment paper. All files must be zipped into a single file.

Submission preparation notice: The assignment consists of multiple distributed projects and components. They may be stored in different locations on your computer when you create them. You must choose your own location to store the project when you create the project. Then, you can copy these projects into a single folder for the blackboard submission. To make sure that you have all the files included in the zip file and they work together, you must test them before submission. You must also download your own submission from the blackboard. Unzip the file on a different machine, and test your assignment and see if you can run the solution in a different machine, because the TA will test your application on a different machine.

If you submitted an empty project folder, or an incomplete project folder, we cannot grade your resubmission after the due date! We grade only what you submitted before the submission due date. Please read FAQ document in the course Web page for more details.

Grading of Programming Assignment/Project

The TA will grade your program following these steps:

(1) The TA will read your program and give points based on the points allocated to each component, the readability of your code (organization of the code and comments), logic, inclusion of the required functions, and correctness of the implementations of each function.

(2) Compile the code. If it does not compile, 40% of the points given in (1) will be deducted. For example, if you are given 20 points in step (1), your points will become 12 if the program fails to compile.(3) If the code passes the compilation, the TA will execute and test the code. If, for any reason, the program gives an incorrect output or crashes for any input, 20% of the points given in (1) will be deducted.

Please notice that the TA will not debug your program to figure out how big or how small the error is. You may lose 40% or 20% of your points for a small error such missing a comma or a space!

Late submission deduction policy:

 No penalty for late submissions that are received within 24 hours of the given due date;

 1% grade deduction for every hour after the first 24 hours of the grace period!

 No submission will be allowed after Tuesday midnight.

 

 
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Posted by on September 17, 2018 in academic writing, Academic Writing

 

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Module 1 – Case MKT501

Module 1 – Case

STP, PRODUCT MANAGEMENT & SITUATION ANALYSIS

Assignment Overview

A Customer Focus

After you determine what you are selling, the next critical part of the marketing plan is to understand to whom you are selling. Knowing your customer is essential to ensure that the company is delivering an appropriate message to the target market. Marketing success is about turning sales leads into profits.
Not only should a company focus on servicing its current customer base, it must also seek out new customers.

This module’s case will focus on defining your product’s customer demographic and psychographic profile, along with customer relationship management (CRM) and customer satisfaction metrics. CRM is about managing current and prospective customers for strong and long customer relationships.

Case Assignment

Check out Nielsen Insights to find out more about today’s customer. Visit Experian and Mosaic® to find out more about using marketing research to develop customer profiles.

Using information from the websites and articles from the library’s full-text article databases (Academic Search Complete, Business Source Complete, and/or ProQuest Central), create a customer profile brief:

Customer Demographics and Psychographics—A review of current customer demographics—explain why this demographic profile is your primary target market.

  • Develop a demographic profile of the potential customer segment.
  • List at least two demographic tools you can use to help develop the demographic profile.
  • Potential customer market demographics. Define the psychographic profile of your customer.

Customer Relationship Management—Find two CRM tools that help companies identify pertinent information about their customer segments.

  • How will you use these tools to manage the customer relationship?

Since you are engaging in research, be sure to cite and reference the sources in APA format. The paper should be written in third person; this means words like “I”, “we”, and “you” are not appropriate. For more information see Differences Between First and Third Person.

Use the attached APA-formatted template (MKT501 Case1) to create your submission.

Assignment Expectations

Your submission will include:

  • Trident University International’s cover page
  • A 4- to 5-page paper with APA citations (2- to 3-sentence introduction, body, 2- to 3-sentence conclusion)
  • The reference list page in APA format

Grading Note:

At Trident University International, rubrics are used for grading. These rubrics specify the points available for each component of an assignment. Points are earned based on the level of the work submitted. The rubric located in the case dropbox is used for this case.

Case

Nielsen Insights
http://www.nielsen.com/us/en/insights.html

Experian Services Marketing
http://www.experian.com/marketing-services/marketing-services.html

Mosaic
https://www.experian.com/assets/marketing-services/product-sheets/mosaic-usa.pdf

Understanding Your Customers: How Demographics and Psychographics Can Help
https://extension.psu.edu/understanding-your-customers-how-demographics-and-psychographics-can-help

Psychographics Are Just as Important for Marketers as Demographics
https://hbr.org/2016/03/psychographics-are-just-as-important-for-marketers-as-demographics

What is customer relationship management?
https://canadabusiness.ca/managing-your-business/marketing-and-sales/sales-and-customer-relationship-management/what-is-customer-relationship-management/

What is a CRM system? Your guide to customer relationship management
https://www.cio.com/article/2439505/customer-relationship-management/customer-relationship-management-crm-definition-and-solutions.html

 
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Posted by on September 12, 2018 in Academic Writing

 

CM4 Term Paper Brief

1
CM4 Term Paper Brief
January 2018
Option 2: Critically evaluate the potential of economic theory of construction
procurement as a decision-making tool in the selection of procurement systems.
Background
In this assignment, you are required to draw on a solid theoretical and evidential ground to
critically review the transaction cost theory of construction procurement. You are expected to
meet the following requirements:
1. Show a thorough understanding of TCE and its application to construction procurement
(i.e., explain the theory in your own way).
2. You can choose a context of interest, including non-private finance delivery systems
(traditional method, design-build, management system), Public-Private Partnerships or
collaborative delivery systems.
3. Conduct a literature review that is broad enough to cover most of the important techniques
suitable for procurement system selection and discuss their limitations.
4. Develop a framework to compare the strengths and limitations of existing techniques (TC
based and non-TC based approaches).
5. Building on the result of point 4, you should make a proposal for the way the TC based
theory can be transformed into a decision-aiding tool.
6. Apply the tool you propose to a real-life project and explore the additional insights, if any,
one might gain from the application of TC theory to procurement system selection (for
this, you can consider contrasting the suggestions made by the TC approach and other
methods and explain the disparity, if any.)
Word length
3000 words
Required readings
See the key papers of transaction cost theory of construction procurement in the bibliography
section. Read as many as you can.
Useful information sources/references
1. Your literature review is expected to cover important papers on construction procurement
from the leading project/construction/engineering management journals, including:
ASCE Journal of Construction Engineering and Management (A*)
2
International Journal of Project Management (A)
Construction Management and Economics (A)
ASCE Journal of Management in Engineering (A)
Building Research and Information (A)
IEEE Transactions on Engineering Management (A)
Project Management Journal (B)
2. Conventional delivery systems
1) The Bartlett library has many textbooks on construction procurement systems, such
as
A. Franks, J. 1998, Building Procurement Systems: A Client’s Guide, 3rd edition,
Longman, UK.
B. Masterman, J.W.E. 2001, An Introduction to Building Procurement Systems, E&FN
Spon, London, UK.
2) The following studies on procurement system selection could be useful
A. Sidwell, T. 2001, Literature Review- Value Alignment Process For Project
Delivery.
B. Love, P.E.D., R.M.Skitmore and G.Earl, 1998, Selecting A Suitable
Procurement Method for A Building Project,
Construction Management and
Economics
, 16, 221-233.
C. Skitmore R.M. and D.E. Marsden, 1988, Which Procurement System?
Towards A Universal Procurement Selection Technique,
Construction
Management and Construction,
6, 71-89.
3) HM Treasury’s Procurement Guide
https://www.gov.uk/government/publications/infrastructure-procurement-route
map-a-guide-to-improving-delivery-capability
4) HM Treasury’s Green Book
https://www.gov.uk/government/publications/the-green-book-appraisal-and-eval
uation-in-central-governent
3. Public-Private Partnerships
1) World Bank (2014). Public-Private Parnterships: Reference Guide (Version 2).
Washington
http://www.worldbank.org/en/news/feature/2014/09/09/public-private-refere
nce-guide-version-2
2) UK Private Finance 2 (PF2) procurement guides
https://www.gov.uk/government/publications/private-finance-2-pf2
4. Collaborative delivery system
Cabinet Office (2014). New Models of Construction Procurement. London, HMSO.
Cost Led Procurement
Integrated Project Insurance
Two Stage Open Book
3
https://www.gov.uk/government/collections/new-models-of-construction-procurement
4
Bibliography: Transaction cost theory of construction procurement
All papers are downloadable from my ResearchGate webpages.
1. Chang, C. & Shi Chen (2016) An Analysis of Transitional Public-Private Partnerships Model
in China: Contracting with little recourse to contracts.
Journal of Construction Engineering and
Management
.
2. Chang, C., & Qian, Y. (2015). An Econometric Analysis of Holdup Problems in
Construction Projects.
Journal of Construction Engineering and Management. doi:
10.1061/(ASCE)CO.1943-7862.0000957.
3. Chang, C., & Chou, H.Y. (2014). Transaction-Cost Approach to the Comparative Analysis
of User-Pay and Government-Pay Public-Private Partnership Systems.
Journal of Construction
Engineering and Management
. doi:10.1061/(ASCE)CO.1943-7862.0000883
4. Chang, C. (2013). When Might A Project Company Break Up? The Perspective of
Risk-Bearing Capacity.
Construction Management and Economics, 31(12), 1186-1198.
doi:
10.1080/01446193.2013.868015
5. Chang, C. (2013). Principal-Agent Model of Risk Allocation in Construction Contracts and
Its Critique.
Journal of Construction Engineering and Management.
doi:
10.1061/(ASCE)CO.1943-7862.0000779
6. Chang, C. (2013). A Critical Analysis of Recent Advances in the Techniques for the
Evaluation of Renewable Energy Projects.
International Journal of Project Management, 31(7),
1057-1067. doi:
10.1016/j.ijproman.2013.03.001
7. Chang, C. (2013). A Critical Review of the Application of TCE in the Interpretation of
Risk Allocation in PPP Contracts.
Construction Management and Economics, 31(2), 99-103.
doi:
10.1080/01446193.2012.726365
8. Park, A., & Chang, C. (2013). Impacts of Construction Events on the Project Equity Value
of the Channel Tunnel Project.
Construction Economics and Management, 31(3), 223-237.
9. Chang, C. (2013). Understanding the Hold-up Problem in the Management of
Megaprojects: The Case of the Channel Tunnel Rail Link Project.
International Journal of
Project Management
, 31, 628-637. doi:10.1016/j.ijproman.2012.10.012
10. Chang, C., Ive., & G. (2007). Reversal of Bargaining Power in Construction Project:
meaning, existence and implications.
Construction Management and Economics, 25(8), 845-855.
doi:
10.1080/01446190601164113
11. Ive, G., & Chang, C. Y. (2007). The principle of inconsistent trinity in the selection of
procurement systems.
Construction Management and Economics, 25(7), 677-690.
doi:
10.1080/01446190601164089
12. Chang, C. Y., & Ive, G. (2007). The hold-up problem in the management of construction
projects: A case study of the Channel Tunnel.
International Journal of Project Management,
25(4), 394-404. doi:10.1016/j.ijproman.2007.01.001
5
13. Chang, C., Chou, H., & Wang, M. (2006). Characterising Corporate Governance of the
UK Listed Construction Companies.
Construction Management and Economics, 24(6), 647-656.
doi:
10.1080/01446190500529424
14. Chang, C. (2006). The determinants of the vertical boundaries of the construction firm:
Comment.
Construction Management and Economics, 24(3), 229-232.
doi:
10.1080/01446190500516579
15. Chang, C., & Ive, G. (2003). Discussion of “Model for Understanding, Preventing, and
Resolving Project Disputes” by Panagiotis Mitropoulos and Gregory Howell.
Journal of
Construction Engineering and Management
, 129(2), 231-233.
doi:
10.1061/(ASCE)0733-9364(2001)127:3(223
16. Chang, C., & Ive, G. (2002). Rethinking the multi-attribute approach based procurement
selection technique.
Construction Management and Economics, 20(3), 275-284.
doi:
10.1080/01446190110117608

 
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Posted by on September 9, 2018 in Academic Writing

 

M6 Assignment 2 Submission

M6 Assignment 2 Submission

Instructions

Assignment 2: Analyzing and Interpreting Data

This module taught you about analyzing and interpreting data. In addition, this module taught you how to plan the data collection process and how analyzing data for qualitative research, analyzing data for quantitative research, and analyzing data for mixed methods applied research studies differ. Using your textbook, the Argosy University online library resources, and other scholarly sources, create a data collection and analysis plan. Specifically, discuss the type of applied research study you plan to conduct (qualitative, quantitative, or mixed methods) and why you selected the data analysis technique.

In the last module, you listed your plan for data collection. After restating the purpose of the study, your data collection methods should have been organized and described by research question. In this module, you will add the analysis portion to your plan following your data collection plan for each research question.

Tasks:

  • Assuming that you have collected the data identified in your plan, how will you analyze and interpret the findings?
    • Describe the analysis process that will be used for each research question. In some cases, analysis may include more than one method (e.g., descriptive and inferential statistics). Describe the full analysis process anticipated for each research question.
    • If any statistical tests are needed to analyze the data of any of your research questions, identify the appropriate test and your rationale for its selection.
    • If the data collected produces qualitative findings, describe the analysis process and how you will narrow and interpret the findings so as to answer your research questions.
  • Identify the resources and/or software that will be required to analyze your data.
  • Use at least two scholarly citations and cite the sources in the body of your work as per APA standards.
  • Prepare a reference list.

Support your rationale and analysis by using at least two resources from professional literature in your response. Professional literature may include the Argosy University online library resources; relevant textbooks; peer-reviewed journal articles; and websites created by professional organizations, agencies, or institutions (websites ending in .edu or .gov).

Submission Details:

  • By the due date assigned, save your document as M6_A2_LastName_FirstInitial.doc and submit the document to the Submissions Area.

 

 
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Posted by on August 11, 2018 in Academic Writing

 

hyroidectomy PTH in Predicting Hypocalcaemia

The Role of Post -Thyroidectomy  PTH in Predicting Hypocalcaemia

 

 

Correspondence: Dr.

 

 

 

 

Category: Case series

 

 

 

 

 

 

 

 

 

 

Running title:

 

ABSTRACT

 

 Hypocalcemia is the most common complication after total thyroidecto­my. It is also the leading cause for prolonged hospitalization after thyroidectomy. The purpose of this study is to determine the validity of PTH monitoring six and twelve hours after total thyroidectomy in predicting hypocalcaemia. Nineteen patients who underwent total thyroidectomy alone or with neck dissection were included. PTH levels and calcium levels were monitored for all patients at two major points: at 6 and 12 hours post-operatively. In all patients, corrected calcium level was calculated.

At 6 hours post-operatively, 47% of patients had calculated calcium level< 8, with normal PTH level in 5 of them. At 12 hour post-operatively 37% of patients had calculated calcium level< 8, with normal PTH level in 3 of them. The validity of low serum PTH in predicting the post-operative hypocalcaemia and of normal serum PTH in predicting the normocalcemia were calculated.

 We conculude that there is a strong correlation of postoperative PTH with post thyroidectomy hypocalcaemia. A single serum PTH level 12 hours post-operatively is an accurate predictor of normocalcaemia. Patients with normal PTH and normal calcium level 12 hours postoperatively can be considered for discharge.

 

 

Key Words: Thyroidectomy, hypocalcemia, parathyroid hormone, surgery

 

 

 

 

 

 

Running title:

 

 

INTRODUCTION

Thyroid cancer is the most common endocrine malignancy accounting for approximately 1% of all human cancers and causing approximately 0.5% of all cancer deaths. Total thyroidectomy is the treatment of choice for clinically significant thyroid cancers. Transient hypocalcaemia after total thyroidectomy is reported at 20%-30% in most studies . The search for a blood test that identifies patients who will become hypocalcaemic after total thyroidectomy versus those who will remain normocalcaemic in the early postoperative period has evolved since the late 1980s (1-5) . Transient hypocalcaemia after total thyroidectomy is reported at 20-30% in most studies (2,7). Hypocalcaemia after total thyroidectomy is multi-factorial, but parathyroid dysfunction is the main cause.The incorporation of parathyroid hormone (PTH) levels as a monitor for hypoparathyroidism leading to hypocalcaemia has been the next step in the evolution of this field of research (2). Serum PTH has a half  life of 1 to 4 minutes. Any insult to parathyroid glands with impaired PTH secretion leads to an immediate decline in PTH levels.

Serum calcium homeostasis by PTH occurs through a variety of mechanisms:

  1. It promotes distal tubule calcium re-absorption.
  2. Bone re-absorption.
  3. 1,25(OH)2D mediated intestinal calcium absorption.

The nadir of serum calcium post total thyroidectomy is 24-48h postoperatively and it may be delayed as the 4th  postoperative day (6). Thus, monitoring calcium levels postoperatively, might lead to patients being hospitalized for longer time than otherwise necessary. The risk of hemorrhage and hematoma is mostly in the early postoperative  period, and warrant 24 h in hospital observation.

Inpatient stay beyond 24 h after Total thyroidectomy, in the absence of complications, is not warranted because patients suffer minimal pain (8).

Grodski found that postoperative PTH can be used to stratify the risk of patients developing    hypocalcaemia after thyroidectomy (1). In addition, the routine use of oral calcium supplements was shown to lead to decreased incidence and severity of post-thyroidectomy hypocalcaemia (1) .

In this work we aimed to investigate the role and best timing of PTH monitoring post total thyroidectomy in predicting hypocalcaemia.

 

MATERIALS AND METHODS

In this study we included patients (men and women) that underwent different thyroidectomy procedures: total thyroidectomy  or total thyroidectomy with central neck dissection. PTH levels were monitored for all patients at two major points: at 6 and 12 hours postoperatively. Calcium levels were measured twice a day. Corrected calcium level was calculated using the next formula:

Corrected Ca. = serum calcium + 0.8 (4 – serum albumin)

We defined two different points for hypocalcaemia:

While the corrected calcium level was less than 8 mg/dl

While the PTH level was less than 1.6 Pcmoll/l (8).

 

 

RESULTS

Nineteen patients were included (13 women and 6 men). Age of patients ranged from 20 to 76, with a mean age of 45 years. Patients underwent total thyroidectomy and 4 patients underwent total thyroidectomy with central neck dissection.

Mean time of hospitalization for these patients was 5.05 days (SD 0.97). The PTH levels, and corrected calcium levels (calculated) at three measurements are shown in Table I.

At 6 hours post-operatively, 47% (9 from 19) of patients had calculated calcium level< 8, with normal PTH level in 5 of them. At 12 hours post-operatively 37% (7 from 19) of patients had calculated.

calcium level< 8, with normal PTH level in 3 of them. At 48 h post-operatively, 2 of those 3 patients, had a normal calculated calcium level and were asymptomatic without calcium supplementation.

Seven of our patients (36.8%) received intravenous calcium treatment after the operation. Six of them received also the calcium supplementation. Five from these patients were symptomatic. Furthermore, one patient who underwent thyroidectomy with central neck dissection required 5 month calcium supplementation.

We calculated the validity of  low serum PTH in predicting the post-operative hypocalcaemia and of  normal serum PTH in predicting the normocalcaemia. For low serum PTH, the sensitivity of this test was 55% at 6 hours after the operation, and 71% at 12 hours after the operation. The specificity of this test was 90% at 6 hours after the operation, and 100% at 12 hours after the operation.

The sensitivity of normal serum PTH level as a predictor of normocalcaemia was 91% at 6 hours after the operation and 100% at 12 hours after the operation. The specificity of this test was 44% at 6 hours after the operation and 75 % at 12 hours after the operation.

 

 

DISCUSSION

Hypocalcemia is the most frequent complication of total thyroidectomy. The reported incidence in the literature varies from 1-50% (1). The risk of hypoparathyroidism increases in reoperative thyroid surgery and when central neck is associated (11). Patients symptoms and serum calcium levels dictate the necessity for calcium and vitamin D supplementation. The need of monitoring hypocalcemia is the leading reason for patients’ hospitalizaion beyond 23 hours (7) . Within the last decade, numerous studies have been conducted to predict the factors involved in the early prediction of hypocalcemia following thyroidectomy. Parathyroid hormone assay was one of the most reliable tool to predict postoperative hypocalcemia within hours of total thyroidectomy or completion thyroidectomy ( 11-13).

Several published reports have demonstrated the marked utility of the PTH assay in predicting patients who will develop hypocalcemia after thyroidectomy. However, there is a substantial

variability among these reports about the sensitivity and specificity  of PTH in accurately predicting hypocalcemia. Lam and ker found that all patients with PTH values less than 8pg/mL measured one hour after surgery became hypocalcemic, and all patients with PTH level greater than 9pg/mole did not (14) . Higgins and his colleagues demonstrated that 64% of those patients who subsequently required calcium supplementation had more than 75%  decrease in PTH levels from baseline 20minutes post surgery. Another finding was that most of patients who did not  need calcium supplementation (74%) had  a decrease of less than 75% from baseline (15). For Lombardi and colleague. PTH less than 10 pg/mL measured four or six hours after surgery predicted hypocalcemia with an overall accuracy of 98% (3). Pattou and colleagues  reported that a postoperative PTH level of 12 pg/mL or less was a good predictor of hypocalcemia, but did not state how long after surgery PTH values were obtained (6). Payne and his colleagues found that 6 hours post-operation PTH level is the most accurate predictor for hypocalcaemia and accurately predicts also the normocalcaemia (7).

As we saw earlier, most of the studies are discussing the correct timing of taking the measurements of PTH levels post-operatively. In our study we performed the measurements at 6 and 12 hours after the operation. We saw that the sensitivity of  low PTH as a predictor of hypocalcaemia was higher at the 12 hours measurement. Despite this no absolute PTH levels or percentage decline has 100% sensitivity or specificity. Sensitivity of normal PTH levels predicting normocalcaemia was higher than sensitivity of  low PTH levels predicting hypocalcaemia.

There are a few limitations to the study. First, it is a retrospective non-random review, which may result in selection bias. Secondly, a small number of participants. Further randomised controlled are required.

 

 

 

 

 

 

 

CONCLUSION

In our study we saw that a single serum PTH level 12 hours postoperatively is an accurate predictor of normocalcaemia. Thus, patients with normal PTH and normal calcium level 12 hours post-operatively can be considered for discharge reducing unnecessary hospitalization and patients’ discomfort.

 

 

Acknowledgments

No acknowledgements

 

 

 

 

 

 

 

 

 

 

 

                  References

  1. Grodski, S., Serpell, J. Evidence for the Role of Perioperative PTH Measurement after Total Thyroidectomy as a Predictor of Hypocalcemia. World Journal of Surgery 2008; 32: 1367–1373.
  2. LoGerfo, P., Gates R., Gazetas, P. Outpatient and Short-stay Thyroid Surgery. Head and Neck;2006; 13 (2): 97 – 101.
  3. Lombardi, C.., Raffaelli, M., Princi, P. et al. Early prediction of postthyroidectomyhypocalcemia by one single iPTH measurement. Surgery;2006; 136: 1236-1241.
  4. Marohn M.R, LaCivita K.A. Evaluation of total/near-total thyroidectomy in a short-stay hospitalization: safe and cost-effective. Surgery;2006; 118:943–948.
  5. McHenry C. R. ‘‘Same-day’’ thyroid surgery: an analysisof safety, cost savings, and outcome. American Surgery:1997: 63:586–589.
  6. Pattou, F., Combemale, F., Fabre. et al. Hypocalcemia following Thyroid Surgery: Incidence and Prediction of Outcome. World Journal of Surgery:1998: 22, 718–724.
  7. Payne, R. J., Hier, M. P., Tamilia, M. et al. Same-Day Discharge After Total Thyroidectomy: The Value of 6-hour Serum Parathyroid Hormone and Calcium Levels. Head and Neck:2004; 27: 1 – 7.
  8. Kalmovich LM1, Cote V, Sands N, Thyroidectomy: Excatly how painful is it? J otology head and neck surgery; 2010:39(3),277-83.
  9. Payne, R. J., Tewfik, M. A., Hier, M. et al. Benefits Resulting from 1-and 6-Hour Parathyroid Hormone and Calcium Levels After Thyroidectomy. Otolaryngology — Head and Neck Surgery;2005; 133: 386-390.
  10. Sywak, M. S., Palazzo, F. F., Yeh, M. et al. Parathyroid hormone assay predicts hypocalcaemia after total thyroidectomy. ANZ Journal of Surgery;2007; 77: 667–670.
  11. McLeod IK, Arciero C, Noordzij JP, et al. The use of rapid parathyroid hor­mone assay in predicting postoperative hypocalcemia after total or comple­tion thyroidectomy. Thyroid. 2006;16:259–65
  12. Noordzij JP, Lee SL, Bernet VJ, et al. Early prediction of hypocalcemia after thyroidectomy using parathyroid hormone: an analysis of pooled individual patient data from nine observational studies. J Am Coll Surg. 2007;205:748–54
  13. Khafif A, Pivoarov A, Medina JE et al. Parathyroid hormone: A sensitive predictor of hypocalcemia following total Otolaryngol Head Neck Surg. 2006;134:907–10).
  14. Lam A, Kerr P. Parathyroid hormone: an early predictor of postthyroidectomy hypocalcemia. Laryngoscope. 2003;113(12):2196-200.
  15. Higgins KM, Mandell DL, Govindaraj S et al. The role of intraoperative rapid parathyroid hormone monitoring for predicting thyroidectomy-related hypocalcemia. Arch Otolaryngol Head Neck Surg. 2004;130(1):63-7

 

 

 

 

 

Table I. PTH and calcium level measurements at two different post-operation time points

  6 hours after the operation 12 hours after the operation
PTH level

(mean (SD))

3.36 (2.58) 3.27 (2.47)
Corrected calcium

(mean (SD))

8.04 (0.42) 8.04 (0.55)

 

 

 

 
 

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Order

 

 

A = 70, B = 0.95, C = 1000

 

A typical fish farming process might involve placing small fish (fingerlings) in a dam, waiting for them to grow, and then harvesting all of the remaining fish.

 

People who rely on growing fish as a source of food are faced with the problem of working out when is the best time to harvest the fish, because although the fish grow bigger as time passes, unfortunately some of them die before they are harvested for food.

 

Data was collected and analysed for a particular species of fish. The following information was obtained:

 

Fish Length

The following formula gives a relationship between the fish length (L) in centimetres and time elapsed (t) in months since the fingerlings were placed in the dam:

L  = A (1 – Bt )

 

Fish Weight

The following weight-length data is available for the species concerned:

 

Length (cm) 10.1 25.0 32.6 35.4 43.8 45.5 55.7
Weight (g) 15 236 520 660 1250 1425 2590

 

Length of Life

For every ‘C’ fingerlings of this species of fish placed in the dam, the number, n, still alive after t months is given by the formula:

N = C x Bt

 

 

Based on this information, find the best time to harvest all of the fish remaining in the dam in order to get the maximum weight of live fish. Validate your solution using technology.

 

 
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System Quality Requirements Engineering (SQUARE)

  • Due to the growth and sophistication of cyber-attacks against organizations, the client and software developers need to agree on security definitions derived from the client’s business goals. As a software engineer, you have explored the concept of System Quality Requirements Engineering (SQUARE). Now you need to convince your team to build security and quality concepts into the early stages of the development life cycles. Your job is to discuss SQUARE methodology or SQUARE steps to show your team the advantages of using SQUARE methodology in the development stage. How will you accomplish this? What are some things you might do to get the team on board with your plan?
  • Note: The Security Quality Requirements Engineering (SQUARE) project is identifying and assessing processes and techniques to improve requirements identification, analysis, specification, and management. The project is also focusing on management issues associated with the development of good security requirements.
 
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Posted by on July 23, 2018 in academic writing

 

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