Wednesday, September 24, 2008
Love: Never Give Up!
A true love story that love does come when we least Expect it. If you think that the circumstances in your life will inhibit any chance of finding the love of your life, you may be in for a surprise. Rae thought that she had no chance at ever finding her
Wednesday, September 17, 2008
Enzyme kinetics
Enzyme kinetics is the study of the chemical reactions that are catalysed by enzymes, with a focus on their reaction rates. The study of an enzyme's kinetics reveals the catalytic mechanism of this enzyme, its role in metabolism, how its activity is controlled, and how a drug or a poison might inhibit the enzyme.
Enzymes are usually protein molecules that manipulate other molecules — the enzymes' substrates. These target molecules bind to an enzyme's active site and are transformed into products through a series of steps known as the enzymatic mechanism. These mechanisms can be divided into single-substrate and multiple-substrate mechanisms. Kinetic studies on enzymes that only bind one substrate, such as triosephosphate isomerase, aim to measure the affinity with which the enzyme binds this substrate and the turnover rate.
Enzymes are usually protein molecules that manipulate other molecules — the enzymes' substrates. These target molecules bind to an enzyme's active site and are transformed into products through a series of steps known as the enzymatic mechanism. These mechanisms can be divided into single-substrate and multiple-substrate mechanisms. Kinetic studies on enzymes that only bind one substrate, such as triosephosphate isomerase, aim to measure the affinity with which the enzyme binds this substrate and the turnover rate.
Wednesday, September 10, 2008
Microbiology
Microbiology is the study of microorganisms, which are unicellular or cell-cluster microscopic organisms. This includes eukaryotes such as fungi and protists, and prokaryotes, which are bacteria and archaea. Viruses, though not strictly classed as living organisms, are also studied. In short; microbiology refers to the study of life and organisms that are too small to be seen with the naked eye.
Microbiology is a broad term which includes virology, mycology, parasitology and other branches. A microbiologist is a specialist in microbiology.
Microbiology is researched actively, and the field is advancing continually. We have probably only studied about one percent of all of the microbe species on Earth. Although microbes were first observed over three hundred years ago, the field of microbiology can be said to be in its infancy relative to older biological disciplines such as zoology and botany.
Microbiology is a broad term which includes virology, mycology, parasitology and other branches. A microbiologist is a specialist in microbiology.
Microbiology is researched actively, and the field is advancing continually. We have probably only studied about one percent of all of the microbe species on Earth. Although microbes were first observed over three hundred years ago, the field of microbiology can be said to be in its infancy relative to older biological disciplines such as zoology and botany.
Tuesday, August 26, 2008
Retroviruses
The genetic material in retroviruses is in the form of RNA molecules, while the genetic material of their hosts is in the form of DNA. When a retrovirus infects a host cell, it will introduce its RNA together with some enzymes, namely reverse transcriptase and integrase, into the cell. This RNA molecule from the retrovirus must produce a DNA copy from its RNA molecule before it can be integrated into the genetic material of the host cell. The process of producing a DNA copy from an RNA molecule is termed reverse transcription. It is carried out by one of the enzymes carried in the virus, called reverse transcriptase. After this DNA copy is produced and is free in the nucleus of the host cell, it must be incorporated into the genome of the host cell. That is, it must be inserted into the large DNA molecules in the cell (the chromosomes). This process is done by another enzyme carried in the virus called integrase.
Now that the genetic material of the virus is incorporated and has become part of the genetic material of the host cell, it can be said that the host cell is now modified to contain a new gene. If this host cell divides later, its descendants will all contain the new genes. Sometimes the genes of the retrovirus do not express their information immediately.
Now that the genetic material of the virus is incorporated and has become part of the genetic material of the host cell, it can be said that the host cell is now modified to contain a new gene. If this host cell divides later, its descendants will all contain the new genes. Sometimes the genes of the retrovirus do not express their information immediately.
Friday, August 22, 2008
Run-time system
In computer science, the runtime system is software that provides services for a running program but is itself not considered to be part of the operating system.[citation needed]
Examples include:
* the code that is generated by the compiler to manage the runtime stack.
* library code for handling memory management (for example, malloc).
* code that handles dynamic loading and linking.
* debugger code that is generated at compile time or run time.
* application-level thread management code.
Byte-code interpreters and virtual machines can also be considered runtime systems. Services that run in concurrent processes are more likely to be considered middleware.
Examples include:
* the code that is generated by the compiler to manage the runtime stack.
* library code for handling memory management (for example, malloc).
* code that handles dynamic loading and linking.
* debugger code that is generated at compile time or run time.
* application-level thread management code.
Byte-code interpreters and virtual machines can also be considered runtime systems. Services that run in concurrent processes are more likely to be considered middleware.
Tuesday, August 12, 2008
Network telescope
A network telescope (also known as a darknet, internet motion sensor or black hole) is an internet system that allows one to observe different large-scale events taking place on the Internet. The basic idea is to observe traffic targeting the dark (unused) address-space of the network. Since all traffic to these addresses is suspicious, one can gain information about possible network attacks (random scanning worms, and DDoS backscatter) as well as other misconfigurations by observing it.
The resolution of the Internet telescope is dependent on the number of dark addresses it monitors. For example, a large Internet telescope that monitors traffic to 16,777,216 addresses (a /8 Internet telescope in IPv4), has a higher probability of observing a relatively small event than a smaller telescope that monitors 65,536 addresses (a /16 Internet telescope).
A variant of a network telescope is a sparse darknet, or greynet, consisting of a region of IP address space that is sparsely populated with 'darknet' addresses interspersed with active (or 'lit') IP addresses.
The resolution of the Internet telescope is dependent on the number of dark addresses it monitors. For example, a large Internet telescope that monitors traffic to 16,777,216 addresses (a /8 Internet telescope in IPv4), has a higher probability of observing a relatively small event than a smaller telescope that monitors 65,536 addresses (a /16 Internet telescope).
A variant of a network telescope is a sparse darknet, or greynet, consisting of a region of IP address space that is sparsely populated with 'darknet' addresses interspersed with active (or 'lit') IP addresses.
Wednesday, August 06, 2008
Wide Area Augmentation System
The Wide Area Augmentation System (WAAS) is an air navigation aid developed by the Federal Aviation Administration to augment the Global Positioning System (GPS), with the goal of improving its accuracy, integrity, and availability. Essentially, WAAS is intended to enable aircraft to rely on GPS for all phases of flight, including precision approaches to any airport within its coverage area.
WAAS uses a network of ground-based reference stations (Benchmark DGPSRs transmitting differential corrections (DCs, located within spaces protected from the public inside airportsin North America and Hawaii, to measure small variations in the GPS satellites' signals in the western hemisphere. Measurements from the reference stations are routed to master stations, which queue the received DCs and send the correction messages to geostationary WAAS satellites in a timely manner (at least every 5 seconds or better). Those satellites broadcast the correction messages back to Earth, where WAAS-enabled GPS receiver uses the corrections while computing its position to improve accuracy. The longer any given DC has been delayed, the less benefit it will produce.
The International Civil Aviation Organization (ICAO) calls this type of system a Satellite Based Augmentation System (SBAS). Europe and Asia are developing their own SBASs, the Indian Gagan, the European Geostationary Navigation Overlay Service (EGNOS) and the Japanese Multi-functional Satellite Augmentation System (MSAS), respectively. Commercial systems include StarFire and OmniSTAR.
WAAS uses a network of ground-based reference stations (Benchmark DGPSRs transmitting differential corrections (DCs, located within spaces protected from the public inside airportsin North America and Hawaii, to measure small variations in the GPS satellites' signals in the western hemisphere. Measurements from the reference stations are routed to master stations, which queue the received DCs and send the correction messages to geostationary WAAS satellites in a timely manner (at least every 5 seconds or better). Those satellites broadcast the correction messages back to Earth, where WAAS-enabled GPS receiver uses the corrections while computing its position to improve accuracy. The longer any given DC has been delayed, the less benefit it will produce.
The International Civil Aviation Organization (ICAO) calls this type of system a Satellite Based Augmentation System (SBAS). Europe and Asia are developing their own SBASs, the Indian Gagan, the European Geostationary Navigation Overlay Service (EGNOS) and the Japanese Multi-functional Satellite Augmentation System (MSAS), respectively. Commercial systems include StarFire and OmniSTAR.
Wednesday, July 30, 2008
Run-time system
In computer science, the runtime system is software that provides services for a running program but is itself not considered to be part of the operating system.[citation needed]
Examples include:
* the code that is generated by the compiler to manage the runtime stack.
* library code for handling memory management (for example, malloc).
* code that handles dynamic loading and linking.
* debugger code that is generated at compile time or run time.
* application-level thread management code.
Byte-code interpreters and virtual machines can also be considered runtime systems. Services that run in concurrent processes are more likely to be considered middleware.
Examples include:
* the code that is generated by the compiler to manage the runtime stack.
* library code for handling memory management (for example, malloc).
* code that handles dynamic loading and linking.
* debugger code that is generated at compile time or run time.
* application-level thread management code.
Byte-code interpreters and virtual machines can also be considered runtime systems. Services that run in concurrent processes are more likely to be considered middleware.
Wednesday, July 23, 2008
Deadlocks
In some cases, two transactions may, in the course of their processing, attempt to access the same portion of a database at the same time, in a way that prevents them from proceeding. For example, transaction A may access portion X of the database, and transaction B may access portion Y of the database. If, at that point, transaction A then tries to access portion Y of the database while transaction B tries to access portion X, a deadlock occurs, and neither transaction can move forward. Transaction-processing systems are designed to detect these deadlocks when they occur. Typically both transactions will be cancelled and rolled back, and then they will be started again in a different order, automatically, so that the deadlock doesn't occur again. Or sometimes, just one of the deadlocked transactions will be cancelled, rolled back, and automatically re-started after a short delay.
Deadlocks can also occur between three or more transactions. The more transactions involved, the more difficult they are to detect, to the point that transaction processing systems find there is a practical limit to the deadlocks they can detect.
Deadlocks can also occur between three or more transactions. The more transactions involved, the more difficult they are to detect, to the point that transaction processing systems find there is a practical limit to the deadlocks they can detect.
Wednesday, July 16, 2008
Data quality
1. Data Quality refers to the degree of excellence exhibited by the data in relation to the portrayal of the actual phenomena. GIS Glossary
2. The state of completeness, validity, consistency, timeliness and accuracy that makes data appropriate for a specific use. Government of British Columbia
3. The totality of features and characteristics of data that bears on their ability to satisfy a given purpose; the sum of the degrees of excellence for factors related to data
2. The state of completeness, validity, consistency, timeliness and accuracy that makes data appropriate for a specific use. Government of British Columbia
3. The totality of features and characteristics of data that bears on their ability to satisfy a given purpose; the sum of the degrees of excellence for factors related to data
Thursday, July 10, 2008
Object-relational database
An object-relational database (ORD) or object-relational database management system (ORDBMS) is a database management system (DBMS) similar to a relational database, but with an object-oriented database model: objects, classes and inheritance are directly supported in database schemas and in the query language. In addition, it supports extension of the data model with custom data-types and methods.
One aim for this type of system is to bridge the gap between conceptual data modeling techniques such as Entity-relationship diagram (ERD) and object-relational mapping (ORM), which often use classes and inheritance, and relational databases, which do not directly support them.
Another, related, aim is to bridge the gap between relational databases and the object-oriented modeling techniques used in programming languages such as Java (programming language), C++ or C#. However, a more popular alternative for achieving such a bridge is to use a standard relational database systems with some form of ORM software.
One aim for this type of system is to bridge the gap between conceptual data modeling techniques such as Entity-relationship diagram (ERD) and object-relational mapping (ORM), which often use classes and inheritance, and relational databases, which do not directly support them.
Another, related, aim is to bridge the gap between relational databases and the object-oriented modeling techniques used in programming languages such as Java (programming language), C++ or C#. However, a more popular alternative for achieving such a bridge is to use a standard relational database systems with some form of ORM software.
Wednesday, July 02, 2008
Types of spam
Spam has several definitions, varying by the source.
* Unsolicited bulk e-mail (UBE)—unsolicited e-mail, sent in large quantities.
* Unsolicited commercial e-mail (UCE)—this more restrictive definition is used by regulators whose mandate is to regulate commerce, such as the U.S. Federal Trade Commission.
* Any email message that is fraudulent.
* Any email message where the sender’s identity is forged, or messages sent though unprotected SMTP servers, unauthorized proxies, or botnets
* Unsolicited bulk e-mail (UBE)—unsolicited e-mail, sent in large quantities.
* Unsolicited commercial e-mail (UCE)—this more restrictive definition is used by regulators whose mandate is to regulate commerce, such as the U.S. Federal Trade Commission.
* Any email message that is fraudulent.
* Any email message where the sender’s identity is forged, or messages sent though unprotected SMTP servers, unauthorized proxies, or botnets
Tuesday, June 24, 2008
Grayware
Grayware (or greyware) is a general term sometimes used as a classification for applications that behave in a manner that is annoying or undesirable, and yet less serious or troublesome than malware. Grayware encompasses spyware, adware, dialers, joke programs, remote access tools, and any other unwelcome files and programs apart from viruses that are designed to harm the performance of computers on your network. The term has been in use since at least as early as September 2004.
Grayware refers to applications or files that are not classified as viruses or trojan horse programs, but can still negatively affect the performance of the computers on your network and introduce significant security risks to your organization. Often grayware performs a variety of undesired actions such as irritating users with pop-up windows, tracking user habits and unnecessarily exposing computer vulnerabilities to attack.
Grayware refers to applications or files that are not classified as viruses or trojan horse programs, but can still negatively affect the performance of the computers on your network and introduce significant security risks to your organization. Often grayware performs a variety of undesired actions such as irritating users with pop-up windows, tracking user habits and unnecessarily exposing computer vulnerabilities to attack.
Wednesday, June 18, 2008
EICAR test file
The EICAR test file (official name: EICAR Standard Anti-Virus Test File) is a file, developed by the European Institute for Computer Antivirus Research, to test the response of computer antivirus (AV) programs. The rationale behind it is to allow people, companies, and AV programmers to test their software without having to use a real computer virus that could cause actual damage should the AV not respond correctly. EICAR likens the use of a live virus to test AV software to setting a fire in a trashcan to test a fire alarm, and promotes the EICAR test file as a safe alternative.
A compliant virus scanner, when detecting the file, will respond in exactly the same manner as if it found genuinely harmful code. Its use can be more versatile than straightforward detection - for example, a file containing the EICAR test string can be compressed or archived, and then the antivirus software can be run to see whether it can detect the test string in the compressed file.
A compliant virus scanner, when detecting the file, will respond in exactly the same manner as if it found genuinely harmful code. Its use can be more versatile than straightforward detection - for example, a file containing the EICAR test string can be compressed or archived, and then the antivirus software can be run to see whether it can detect the test string in the compressed file.
Wednesday, June 11, 2008
Systems psychology
Systems psychology is a branch of applied psychology that studies human behaviour and experience in complex systems. It is inspired by systems theory and systems thinking, and based on the theoretical work of Roger Barker, Gregory Bateson, Humberto Maturana and others. It is an approach in psychology, in which groups and individuals, are considered as systems in homeostasis. Alternative terms here are "systemic psychology", "systems behavior", and "systems-based psychology".
Tuesday, June 03, 2008
Types of systems psychology
In the scientific literature different kind of systems psychology have been mentioned in the scientific literature:
Applied systems psychology
De Greene in 1970 described applied systems psychology as being connected with engineering psychology and human factor.
Cognitive systems theory
Cognitive systems psychology is a part of cognitive psychology and like existential psychology, attempts to dissolve the barrier between conscious and the unconscious mind.
Contract-systems psychology
Contract-systems psychology is about the human systems actualization through praticipative organizations.
Family systems psychology
Family systems psychology is a more general name for the subfield of family thearpists and like Murray Bowen, Michael E. Kerr, and Baard. and researchers have begun to theoretize a psychology of the family as a system.
Organismic-systems psychology
Through the application of organismic-systems biology to human behavior Ludwig von Bertalanffy conceived and developed the organismic-systems psychology, as the theoretical prospect needed for the gradual comprehension of the various ways human personalities may evolve and how could they evolve properly
Applied systems psychology
De Greene in 1970 described applied systems psychology as being connected with engineering psychology and human factor.
Cognitive systems theory
Cognitive systems psychology is a part of cognitive psychology and like existential psychology, attempts to dissolve the barrier between conscious and the unconscious mind.
Contract-systems psychology
Contract-systems psychology is about the human systems actualization through praticipative organizations.
Family systems psychology
Family systems psychology is a more general name for the subfield of family thearpists and like Murray Bowen, Michael E. Kerr, and Baard. and researchers have begun to theoretize a psychology of the family as a system.
Organismic-systems psychology
Through the application of organismic-systems biology to human behavior Ludwig von Bertalanffy conceived and developed the organismic-systems psychology, as the theoretical prospect needed for the gradual comprehension of the various ways human personalities may evolve and how could they evolve properly
Wednesday, May 28, 2008
Software Process Innovation
Software process innovation can take the form of the development of new techniques, tools or methods for software development, as for example with extreme programming (XP) or SCRUM. It can concentrate on one phase of a more traditional development process, such as requirements elicitation - introducing more creative or imaginative techniques or tools. Software process innovations can be user-led , where expert users collaborate in the writing of software which meets their own needs (for example the Linux community). Process innovation can also focus on market analysis:where the demand for new software products lies. Common to many software process innovations is a focus on productive work, and the avoidance of thrashing – unfocused work which is neither productive nor generating new ideas. A more modern pre-occupation is with ‘flow’ , (Csíkszentmihályi’s description of a mental state characterized by high energy and focus) in a software team
The relationship between software process innovation and innovative software products is a complex one. At the moment there is no particular evidence that innovative software processes necessarily result in innovative software products. Some forms of innovative software products may be best developed using traditional methods .
The relationship between software process innovation and innovative software products is a complex one. At the moment there is no particular evidence that innovative software processes necessarily result in innovative software products. Some forms of innovative software products may be best developed using traditional methods .
Tuesday, May 20, 2008
Organizational psychology
Industrial and organizational psychology also known as "work psychology", "occupational psychology" or "personnel psychology" concerns the application of psychological theories, research methods, and intervention strategies to workplace issues. Industrial and organizational psychologists are interested in making organizations more productive while ensuring workers are able to lead physically and psychologically healthy lives. Relevant topics include personnel psychology, motivation and leadership, employee selection, training and development, organization development and guided change, organizational behavior, and work and family issues.
Tuesday, May 13, 2008
Roboticist
A roboticist designs, builds, programs, and experiments with robots. Since robotics is a highly interdisciplinary field, roboticists often have backgrounds in a number of disciplines including computer science, mechanical engineering, electrical engineering, and computer engineering. Roboticists often work for university, industry, and government research labs, but may also work for startup companies and other entrepreneurial firms. Amateur Roboticist is also a growing hobby all over the world.
Wednesday, May 07, 2008
Transport engineering
Transport engineering (alternatively transportation engineering) is the science of safe and efficient movement of people and goods (transport). It is a sub-discipline of civil engineering.
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