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HandWiki is the world's largest wiki-style encyclopedia dedicated to science, technology and computing. It allows you to create and edit articles as long as you have external citations and login account. In addition, this is a content management environment that can be used for collaborative editing of original scholarly content, such as books, manuals, monographs and tutorials.

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Pathophysiology of Parkinson's Disease
The pathophysiology of Parkinson's disease is death of dopaminergic neurons as a result of changes in biological activity in the brain with respect to Parkinson's disease (PD). There are several proposed mechanisms for neuronal death in PD; however, not all of them are well understood. Five proposed major mechanisms for neuronal death in Parkinson's Disease include protein aggregation in Lewy bodies, disruption of autophagy, changes in cell metabolism or mitochondrial function, neuroinflammation, and blood-brain barrier (BBB) breakdown resulting in vascular leakiness.
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  • 28 Nov 2022
Topic Review
Pneumococcal Infection
A pneumococcal infection is an infection caused by the bacterium Streptococcus pneumoniae, which is also called the pneumococcus. S. pneumoniae is a common member of the bacterial flora colonizing the nose and throat of 5–10% of healthy adults and 20–40% of healthy children. However, it is also a cause of significant disease, being a leading cause of pneumonia, bacterial meningitis, and sepsis. The World Health Organization estimates that in 2005 pneumococcal infections were responsible for the death of 1.6 million children worldwide.
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  • 28 Nov 2022
Topic Review
American Sparrow
American sparrows are a group of mainly New World passerine birds, forming the family Passerellidae. American sparrows are seed-eating birds with conical bills, brown or gray in color, and many species have distinctive head patterns. Although they share the name sparrow, American sparrows are more closely related to Old World buntings than they are to the Old World sparrows (family Passeridae). American sparrows are also similar in both appearance and habit to finches, with which they sometimes used to be classified.
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  • 28 Nov 2022
Topic Review
European Nucleotide Archive
The European Nucleotide Archive (ENA) is a repository providing free and unrestricted access to annotated DNA and RNA sequences. It also stores complementary information such as experimental procedures, details of sequence assembly and other metadata related to sequencing projects. The archive is composed of three main databases: the Sequence Read Archive, the Trace Archive and the EMBL Nucleotide Sequence Database (also known as EMBL-bank). The ENA is produced and maintained by the European Bioinformatics Institute and is a member of the International Nucleotide Sequence Database Collaboration (INSDC) along with the DNA Data Bank of Japan and GenBank. The ENA has grown out of the EMBL Data Library which was released in 1982 as the first internationally supported resource for nucleotide sequence data. As of early 2012, the ENA and other INSDC member databases each contained complete genomes of 5,682 organisms and sequence data for almost 700,000. Moreover, the volume of data is increasing exponentially with a doubling time of approximately 10 months.
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  • 28 Nov 2022
Topic Review
VSOP (Planets)
The semi-analytic planetary theory VSOP (French: Variations Séculaires des Orbites Planétaires) is a mathematical model describing long-term changes (secular variation) in the orbits of the planets Mercury to Neptune. The earliest modern scientific model considered only the gravitational attraction between the Sun and each planet, with the resulting orbits being unvarying Keplerian ellipses. In reality, all the planets exert slight forces on each other, causing slow changes in the shape and orientation of these ellipses. Increasingly complex analytical models have been made of these deviations, as well as efficient and accurate numerical approximation methods. VSOP was developed and is maintained (updated with the latest data) by the scientists at the Bureau des Longitudes in Paris. The first version, VSOP82, computed only the orbital elements at any moment. An updated version, VSOP87, computed the positions of the planets directly at any moment, as well as their orbital elements with improved accuracy. At present, the difference between computational predictions and observations is so small that the model seems essentially complete in its physical principles. Such hypothetical deviations are often referred to as post-Keplerian effects.
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  • 28 Nov 2022
Topic Review
Medical Psychology
Medical psychology, or Medico-psychology, is the application of psychological principles to the practice of medicine, primarily drug-oriented, for both physical and mental disorders. A medical psychologist who holds prescriptive authority for specific psychiatric medications and other pharmaceutical drugs must first obtain specific qualifications in psychopharmacology. A trained medical psychologist, or clinical psychopharmacologist who has prescriptive authority, is equated with a mid-level provider who has the authority to prescribe psychotropic medication such as antidepressants for mental health disorders. However, a medical psychologist does not automatically equate with a psychologist who has the authority to prescribe medication. In fact, most medical psychologists do not prescribe medication and do not have the authority to do so. Medical psychologists apply psychological theories, scientific psychological findings, and techniques of psychotherapy, behavior modification, cognitive, interpersonal, family, and lifestyle therapy to improve the psychological and physical health of the patient. Psychologists with postdoctoral specialty training as medical psychologists are the practitioners with refined skills in clinical psychology, health psychology, behavioral medicine, psychopharmacology, and medical science. Highly qualified and postgraduate specialized doctors are trained for service in primary care centers, hospitals, residential care centers, and long-term care facilities and in multidisciplinary collaboration and team treatment.
  • 1.3K
  • 28 Nov 2022
Topic Review
Shunting-Yard Algorithm
In computer science, the shunting-yard algorithm is a method for parsing arithmetical or logical expressions, or a combination of both, specified in infix notation. It can produce either a postfix notation string, also known as Reverse Polish notation (RPN), or an abstract syntax tree (AST). The algorithm was invented by Edsger Dijkstra and named the "shunting yard" algorithm because its operation resembles that of a railroad shunting yard. Dijkstra first described the Shunting Yard Algorithm in the Mathematisch Centrum report MR 34/61. Like the evaluation of RPN, the shunting yard algorithm is stack-based. Infix expressions are the form of mathematical notation most people are used to, for instance "3 + 4" or "3 + 4 × (2 − 1)". For the conversion there are two text variables (strings), the input and the output. There is also a stack that holds operators not yet added to the output queue. To convert, the program reads each symbol in order and does something based on that symbol. The result for the above examples would be (in Reverse Polish notation) "3 4 +" and "3 4 2 1 − × +", respectively. The shunting yard algorithm will correctly parse all valid infix expressions, but does not reject all invalid expressions. For example, "1 2 +" is not a valid infix expression, but would be parsed as "1 + 2". The algorithm can however reject expressions with mismatched parentheses. The shunting-yard algorithm was later generalized into operator-precedence parsing.
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  • 28 Nov 2022
Topic Review
ODB (C++)
ODB is an object-relational mapping (ORM) system for the C++ language. It allows an application developer to persist C++ objects to a relational database without having to deal with tables, columns, or SQL and without manually writing any mapping code. ODB supports C++98/03 and C++11 language standards and comes with optional profiles for Boost and Qt which allow an application developer to seamlessly use value types (data-time, string, binary, uuid, etc.), containers, and smart pointers from these libraries in persistent C++ classes. ODB is free software and is dual-licensed under the GPL and a proprietary license. One notable difference between ODB and other ORM implementations for C++ is its automatic generation of the database mapping code and, optionally, the database schema from the C++ headers that declare the classes. This task is performed by the ODB compiler. The ODB compiler is a real C++ compiler except that instead of producing assembly or machine code, it generates portable C++ which can in turn be compiled by any C++ compiler. The ODB compiler uses the GCC compiler front-end for C++ parsing and is implemented using the new GCC plugin architecture. The ODB compiler also provides comprehensive support for database schema evolution, including fully automatic schema migration, support for immediate and gradual data migration, as well as support for soft model changes. The latter feature allows one to work with multiple schema versions using the same C++ classes. The other components of the ODB system include the common runtime library (libodb) and the database-specific runtime libraries (for example, libodb-mysql). The common runtime library defines object-oriented database interfaces that are used by the application developer to perform various database operations on persistent objects. The database-specific runtimes implement these interfaces for concrete database systems and provide support functionality for the generated database mapping code. To achieve high performance, low overhead, and reliability ODB does not use common database APIs, such as ODBC, to access the relational database. Rather, each database-specific runtime library uses low-level, native C APIs that are specific to each database. ODB currently supports the MySQL, SQLite, PostgreSQL, Oracle, and SQL Server databases. Bulk/batch operations are supported for Oracle and SQL Server. The application can also use multiple databases (for example, MySQL, SQLite, etc.) at the same time. Multi-database support comes in the static and dynamic flavors with the latter allowing the application to dynamically load the database support code for individual database if and when necessary. ODB is not a framework. There is no common base type that all persistent classes should derive from nor are there any restrictions on the data member types in persistent classes. Existing classes can be made persistent with a few or no modifications. ODB is also flexible in the level of insulation it provides to the application developer. It can either completely hide the relational nature of the underlying database or expose some of the details as required.
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  • 28 Nov 2022
Topic Review
Nontransitive Dice
A set of dice is nontransitive if it contains three dice, A, B, and C, with the property that A rolls higher than B more than half the time, and B rolls higher than C more than half the time, but it is not true that A rolls higher than C more than half the time. In other words, a set of dice is nontransitive if the binary relation – X rolls a higher number than Y more than half the time – on its elements is not transitive. It is possible to find sets of dice with the even stronger property that, for each die in the set, there is another die that rolls a higher number than it more than half the time. Using such a set of dice, one can invent games which are biased in ways that people unused to nontransitive dice might not expect (see Example).
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  • 28 Nov 2022
Topic Review
BOSH
BOSH is an open-source software project that offers a toolchain for release engineering, software deployment and application lifecycle management of large-scale distributed services. The toolchain is made up of a server (the BOSH Director) and a command line tool. BOSH is typically used to package, deploy and manage cloud software. While BOSH was initially developed by VMware in 2010 to deploy Cloud Foundry PaaS, it can be used to deploy other software (such as Hadoop, RabbitMQ, or MySQL for instance). BOSH is designed to manage the whole lifecycle of large distributed systems. Since March 2016, BOSH can manage deployments on both Microsoft Windows and Linux servers. A BOSH Director communicates with a single Infrastructure as a service (IaaS) provider to manage the underlying networking and virtual machines (VMs) (or containers). Several IaaS providers are supported: Amazon Web Services EC2, Apache CloudStack, Google Compute Engine, Microsoft Azure, OpenStack, and VMware vSphere. To help support more underlying IaaS providers, BOSH uses the concept of a Cloud Provider Interface (CPI). There is an implementation of the CPI for each of the IaaS providers listed above. Typically the CPI is used to deploy VMs, but it can be used to deploy containers as well. Few CPIs exist for deploying containers with BOSH and only one is actively supported. For this one, BOSH uses a CPI that deploys Pivotal Software's Garden containers (Garden is very similar to Docker) on a single virtual machine, run by VirtualBox or VMware Workstation. In theory, any other container engine could be supported, if the necessary CPIs were developed. Due to BOSH indifferently supporting deployments on VMs or containers, BOSH uses the generic term “instances” to designate those. It is up to the CPI to choose whether a BOSH “instance” is actually a VM or a container.
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