Software architecture.

Xen Project runs in a more privileged CPU state than any other software on the machine.  Responsibilities of the hypervisor include memory management and CPU scheduling of all virtual machines ("domains"), and for launching the most privileged domain ("dom0") - the only virtual machine which by default has direct access to hardware. From the dom0 the hypervisor can be managed and unprivileged domains ("domU") can be launched.  The dom0 domain is typically a version of Linux or BSD. User domains may either be traditional operating systems, such as Microsoft Windows under which privileged instructions are provided by hardware virtualization instructions (if the host processor supports x86 virtualization, e.g., Intel VT-x and AMD-V), or paravirtualized operating systems whereby the operating system is aware that it is running inside a virtual machine, and so makes hypercalls directly, rather than issuing privileged instructions.  Xen Project boots from a bootloader such as GNU GRUB, and then usually loads a paravirtualized host operating system into the host domain (dom0).

History.

Xen originated as a research project at the University of Cambridge led by Ian Pratt, a senior lecturer in the Computer Laboratory, and his PhD student Keir Fraser. The first public release of Xen was made in 2003, with v1.0 following in 2004. Soon after, Pratt and Fraser along with other Cambridge alumni including Simon Crosby and founding CEO Nick Gault created XenSource Inc. to turn Xen into a competitive enterprise product.  The Open Source Xen Project continued to be a supported by XenSource, then by Citrix following XenSource's acquisition in October 2007. This organization supports the development of the free software project and also sells enterprise versions of the software.  To support embedded systems such as smartphone/ IoT with relatively scarce hardware computing resources, the Secure Xen ARM architecture on an ARM CPU was exhibited at Xen Summit on April 17, 2007 held in IBM TJ Watson. The first public release of Secure Xen ARM source code was made at Xen Summit on June 24, 2008 by Sang-bum Suh, a Cambridge alumnus, in Samsung Electronics.  On October 22, 2007, Citrix Systems completed its acquisition of XenSource, and the Xen Project moved to the xen.org domain. This move had started some time previously, and made public the existence of the Xen Project Advisory Board (Xen AB), which had members from Citrix, IBM, Intel, Hewlett-Packard, Novell, Red Hat, Sun Microsystems and Oracle. The Xen Advisory Board advises the Xen Project leader and is responsible for the Xen trademark, which Citrix has freely licensed to all vendors and projects that implement the Xen hypervisor.  Citrix uses the Xen brand itself for some proprietary products unrelated to Xen, including XenApp and XenDesktop.  On April 15, 2013, it was announced that the Xen Project was moved under the auspices of the Linux Foundation as a Collaborative Project. The Linux Foundation launched a new trademark for "Xen Project" to differentiate the project from any commercial use of the older "Xen" trademark. A new community website was launched at xenproject.org as part of the transfer. Project members at the time of the announcement included: Amazon, AMD, Bromium, CA Technologies, Calxeda, Cisco, Citrix, Google, Intel, Oracle, Samsung, and Verizon. The Xen project itself is self-governing.

Xen in Linux distributions and Linux upstream.

Since version 3.0 of the Linux kernel, Xen support for dom0 and domU exists in the mainline kernel.

Uses.

Internet hosting service companies use hypervisors to provide virtual private servers. Amazon EC2 (since August 2006), IBM SoftLayer, Liquid Web, Fujitsu Global Cloud Platform, Linode, OrionVM and Rackspace Cloud use Xen as the primary VM hypervisor for their product offerings.  Virtual machine monitors (also known as hypervisors) also often operate on mainframes and large servers running IBM, HP, and other systems. Server virtualization can provide benefits such as:  Xen's support for virtual machine live migration from one host to another allows workload balancing and the avoidance of downtime.  Virtualization also has benefits when working on development (including the development of operating systems): running the new system as a guest avoids the need to reboot the physical computer whenever a bug occurs. Sandboxed guest systems can also help in computer-security research, allowing study of the effects of some virus or worm without the possibility of compromising the host system.  Finally, hardware appliance vendors may decide to ship their appliance running several guest systems, so as to be able to execute various pieces of software that require different operating systems.

Technology.

Types of virtualization.

Xen offers five approaches to running the guest operating system:

Paravirtualization – modified guests.

Xen provides a form of virtualization known as paravirtualization, in which guests run a modified operating system. The guests are modified to use a special hypercall ABI, instead of certain architectural features.  Through paravirtualization, Xen can achieve high performance even on its host architecture (x86) which has a reputation for non-cooperation with traditional virtualization techniques.  Xen can run paravirtualized guests ("PV guests" in Xen terminology) even on CPUs without any explicit support for virtualization.  Paravirtualization avoids the need to emulate a full set of hardware and firmware services, which makes a PV system simpler to manage and reduces the attack surface exposed to potentially malicious guests.  On 32-bit x86, the Xen host kernel code runs in Ring 0, while the hosted domains run in "Ring 1" (kernel) and "Ring 3" (applications).

Hardware-assisted virtualization, allowing for unmodified guests.

CPUs that support virtualization make it possible to run unmodified guests, including proprietary operating systems (such as Microsoft Windows). This is known as hardware-assisted virtualization, however in Xen this is known as hardware virtual machine (HVM).  HVM extensions provide additional execution modes, with an explicit distinction between the most-privileged modes used by the hypervisor with access to the real hardware (called "root mode" in x86) and the less-privileged modes used by guest kernels and applications with "hardware" accesses under complete control of the hypervisor (in x86, known as "non-root mode"; both root and non-root mode have Rings 0–3).  Both Intel and AMD have contributed modifications to Xen to exploit their respective Intel VT-x and AMD-V architecture extensions. Use of ARM v7A and v8A virtualization extensions came with Xen 4.3.  HVM extensions also often offer new instructions to allow direct calls by a paravirtualized guest/driver into the hypervisor, typically used for I/O or other operations needing high performance. These allow HVM guests with suitable minor modifications to gain many of the performance benefits of paravirtualized I/O.  In current versions of Xen (up to 4.2) only fully virtualized HVM guests can make use of hardware facilities for multiple independent levels of memory protection and paging. As a result, for some workloads, HVM guests with PV drivers (also known as PV-on-HVM, or PVH) provide better performance than pure PV guests.  Xen HVM has device emulation based on the QEMU project to provide I/O virtualization to the virtual machines. The system emulates hardware via a patched QEMU "device manager" (qemu-dm) daemon running as a backend in dom0. This means that the virtualized machines see an emulated version of a fairly basic PC. In a performance-critical environment, PV-on-HVM disk and network drivers are used during normal guest operation, so that the emulated PC hardware is mostly used for booting.

Virtual machine migration.

Administrators can "live migrate" Xen virtual machines between physical hosts across a LAN without loss of availability. During this procedure, the LAN iteratively copies the memory of the virtual machine to the destination without stopping its execution. The process requires a stoppage of around 60–300 ms to perform final synchronization before the virtual machine begins executing at its final destination, providing an illusion of seamless migration. Similar technology can serve to suspend running virtual machines to disk, "freezing" their running state for resumption at a later date.

Target processors.

The Xen hypervisor has been ported to a number of processor families.

Scalability.

Xen can scale to 4095 physical CPUs, 256 VCPUs per HVM guest, 512 VCPUs per PV guest, 16 TB of RAM per host, and up to 1 TB of RAM per HVM guest or 512 GB of RAM per PV guest.

Hosts.

Xen can be shipped in a dedicated virtualization platform, such as Citrix Hypervisor (formerly Citrix XenServer, and before that XenSource's XenEnterprise).  Alternatively, Xen is distributed as an optional configuration of many standard operating systems. Xen is available for and distributed with:

Guests.

Unix-like systems as guests.

Guest systems can run fully virtualized (which requires hardware support), paravirtualized (which requires a modified guest operating system), or fully virtualized with paravirtualized drivers (PVHVM). Most operating systems which can run on PCs can run as a Xen HVM guest. The following systems can operate as paravirtualized Xen guests:  For an updated list differentiating PV and PVHVM support, see DomU Support for Xen.

Microsoft Windows systems as guests.

Xen version 3.0 introduced the capability to run Microsoft Windows as a guest operating system unmodified if the host machine's processor supports hardware virtualization provided by Intel VT-x (formerly codenamed Vanderpool) or AMD-V (formerly codenamed Pacifica).  During the development of Xen 1.x, Microsoft Research, along with the University of Cambridge Operating System group, developed a port of Windows XP to Xen — made possible by Microsoft's Academic Licensing Program. The terms of this license do not allow the publication of this port, although documentation of the experience appears in the original Xen SOSP paper.  James Harper and the Xen open-source community have started developing GPL'd paravirtualization drivers for Windows. These provide front-end drivers for the Xen block and network devices, and allow much higher disk and network performance for Windows systems running in HVM mode. Without these drivers all disk and network traffic has to be processed through QEMU-DM. Subsequently, Citrix has released under a BSD license (and continues to maintain) PV drivers for Windows.

Xen Management Consoles.

Third-party developers have built a number of tools (known as Xen Management Consoles) to facilitate the common tasks of administering a Xen host, such as configuring, starting, monitoring and stopping of Xen guests. Examples include:

Commercial versions.

The Xen hypervisor is covered by the GNU General Public Licence, so all of these versions contain a core of free software with source code. However, many of them contain proprietary additions.

Xen (pronounced ) is a type-1 hypervisor, providing services that allow multiple computer operating systems to execute on the same computer hardware concurrently. It was originally developed by the University of Cambridge Computer Laboratory and is now being developed by the Linux Foundation with support from Intel.

Xen (ausgesprochen /ˈzɛn/)(auch Xen Project, in Abgrenzung zu darauf basierenden kommerziellen Produkten) ist ein Hypervisor, also eine Software, die den Betrieb mehrerer virtueller Maschinen auf einem physischen Computer erlaubt. Sie entstand an der britischen Universität Cambridge und wird heute von dem US-Unternehmen Citrix Systems weiterentwickelt. Der Name leitet sich von der Vorsilbe xeno (, "xénos": Fremder) ab.


History.

From 1830 to 1832, José Joaquín de Olmedo wrote a national anthem (chorus and four verses) as an homage to the nascent Ecuadorian state. This composition, suggested by General Juan José Flores, was not set to music and did not gain popularity. In 1833, a hymn titled "Canción Ecuatoriana" (), of six verses, was published in the "Gaceta del Gobierno del Ecuador" No. 125 of December 28. A composition date of 1830 was given, but most historians do not consider this definitive, because it was by an anonymous author. In 1838, a Canción Nacional (National Song), of a chorus and six verses, appeared included in the pamphlet Poesías by General Flores, which was published by the Government Press. In a later editions, there were changes to the third verse. Even so, for historians, it is the second Canción Nacional that is known.  In 1865, the Argentine musician Juan José Allende, in collaboration with the Ecuadorian Army, presented to the National Congress a musical project for the lyrics by José Joaquín de Olmedo, but it was not well received. In November of this year, at the express request of the president of the Senate, Nicolás Espinosa, the Ambateño poet Juan León Mera Martínez, who was then the secretary of the Senate, wrote and submitted the lyrics of the National Anthem. These lyrics were then sent, with Congressional approval, to Guayaquil, so that Antonio Neumane would set them to music. This is the hymn that would later be officialized as the definitive national anthem.  On January 16, 1866, the complete version of the lyrics by Juan León Mera were published in the Quiteño weekly "El Sud Americano". In 1870, the national anthem premiered in the Plaza Grande (Plaza de la Independencia facing the Palacio de Gobierno), performed by the 2nd Battalion and the Compañía Lírica de Pablo Ferreti, directed by Antonio Neumane. The music was in the key of C flat major. The current introduction of 16 measures was composed by Domingo Brescia and Enrique Marconi in 1901. Today, the hymn is performed in the key of E major from 2001 onward.  In 1913, the Guayaquileño writer and diplomat Víctor Manuel Rendón submitted a new hymn with lyrics adapted from the music of Antonio Neumane, but ultimately the Legislature rejected the proposal.  As a full performance can last up to three minutes, in many instances only a sub-90 second rendition of the chorus is performed at public events like soccer games.

"¡Salve, Oh Patria!" (, ) is the national anthem of Ecuador. The lyrics were written in 1865 by the poet Juan León Mera, under request of the Ecuadorian Senate; the music was composed by Antonio Neumane. However, it was not officially adopted by the Congress until September 29, 1948.

Salve, Oh Patria! ist seit 1886 die Nationalhymne von Ecuador. Der Verfasser des Textes, Juan León Mera, war später Präsident des Senates von Ecuador und gilt als einer der bedeutendsten Schriftsteller seines Landes im 19. Jahrhundert. Die Musik wurde von Antonio Neumane komponiert. Der offizielle Text hat neben dem Refrain sechs Strophen, von denen in der Regel nur die hier wiedergegebene zweite gesungen wird.


Background.

With increasing problems of town centre congestion, and demand for on-street parking, coupled with the pressures on police resources, and the low priority given by some police forces to the enforcement of parking regulations, the "Road Traffic Act 1991" permitted local authorities to apply for the legal powers to take over the enforcement of on-street, as well as off-street, car parking regulations from the police, in return they would be allowed to keep the proceeds. Thus in areas where DPE has been granted, parking offences cease to be criminal offences.  Without DPE, fixed penalties (not fines, because the recipient can exercise their right to a Court hearing instead) from the issue of parking tickets by the police is collected by Fixed Penalty Offices (each of which is part of a local Magistrates' Court in each county or metropolitan area) and passed directly to central government. With DPE in place, the local authority retains the income generated from parking penalties to finance parking enforcement and certain other activities such as local transport measures. Local authorities have been able to charge for on-street parking since 1958, but without the effective enforcement provided by DPE, such charging was of limited effect. Local authorities adopting DPE generally employ contractors to run their scheme.  The powers granted by DPE to deal with parking offences include:  Appeals against council decisions on PCNs can be made to the London Tribunals (formerly the Parking and Traffic Appeals Service, PATAS) in London, the Traffic Penalty Tribunal (TPT) in England and Wales, the Scottish Parking Appeals Service in Scotland and the Northern Ireland Traffic Penalty Tribunal in Northern Ireland. These bodies are tribunals established under DPE; appeals against their decisions can generally be made only on points of law, through judicial review. They are independent of the councils, albeit being funded by them in England and Wales through a fee of 60p per PCN issued. In Northern Ireland the Tribunal is operated by the Northern Ireland Court Service and all PCNs are issued by the Department for Regional Development as opposed to local councils.

Revenue potential.

Local authorities raise more than £1 billion a year from parking fines. Some of the money raised goes into the costs of operating the system. Local authorities must report their income from parking fines and charges and must also state what any surplus is spent on. Typically the revenue from such schemes (if lost parking fees from infringing motorists are excluded) is greater than the cost of running the scheme and the surplus goes into the public purse, along with the parking fee income. The surplus revenue is ring-fenced to be used for transport related expenditure unless the Council is judged to be 'excellent' by the Audit Commission, in which case the surplus goes into the Council's general budget (as is the case for Kensington and Chelsea). In 2005/6 the City of Westminster received GBP 65.4 million in parking revenue for on-street parking. From one road in London, £3.2 million was raised in the year 2005-06.  Some councils have used, attempted to use or been accused of attempting to use parking enforcement as a source of revenue.

Benefits.

Claimed benefits for DPE include:

Reform.

The summary of an inquiry into parking policy and enforcement by the "Transport Committee" of the House of Commons states:

Decriminalised parking enforcement (DPE) is the name given in the United Kingdom to the civil enforcement of car parking regulations, carried out by civil enforcement officers, operating on behalf of a local authority. The Road Traffic Act 1991 (c. 40) provided for the decriminalisation of parking-related contraventions committed within controlled parking zones (CPZ) administered by local councils across the UK. The CPZs under the control of the local councils are also referred to as yellow routes and they can be easily identified with yellow lines marked on the roads with relevant time plates. Councils employ parking attendants to enforce their CPZs directly.

Die Überwachung des ruhenden Verkehrs (auch "Parkraumüberwachung; PÜ") ist die Wahrnehmung der hoheitlichen Aufgabe, Verstöße im ruhenden Straßenverkehr als Verkehrsordnungswidrigkeit gemäß Bußgeldkatalog zu ahnden. Darunter fallen vor allem Verstöße gegen Halt- und Parkverbote sowie zeitlich begrenztes und gebührenpflichtiges Parken.


Early years.

Simonov was born in Petrograd in 1915. His mother, Princess Aleksandra Leonidovna Obolenskaya, came of the Rurikid Obolensky family. His father, Mikhail Agafangelovich Simonov, an officer in the Tsar's army, left Russia after the Revolution of 1917 and died in Poland sometime after 1921. Konstantin's mother, Alexandra, remained in Russia with Konstantin. In 1919 his mother married Alexander Ivanishev, a Red Army officer and veteran of World War I.  Konstantin spent several years as a child in Ryazan while his stepfather worked as an instructor at a local military school. They later moved to Saratov, where Konstantin spent the remainder of his childhood. After completing a basic seven-year education in 1930 in Saratov, he went into the factory workshop school (Fabrichno-Zavodskoe Uchilishche-FZU) to become a lathe-turner. In 1931 his family moved to Moscow. After completing his precision-engineering course, Simonov went to work in a factory, where he remained until 1935. During these years he changed his given name from Kirill to Konstantin because he could not pronounce the sound "r" without an aristocratic lisp.  The first of Simonov's poems were published in 1936 in the journals "Young Guard" and "October". After completing schooling at the Maxim Gorky Literature Institute in 1938, Simonov entered the Moscow Institute of History, Philosophy, and Literature. His time there was interrupted when he was sent as a war correspondent to cover the Battle of Khalkhin Gol of May–September 1939 in Mongolia. Simonov returned to the Institute in 1939.

Works.

Simonov's first play, "The History of One Love", was written in 1940, and performed on stage at the Memorial Lenin Komsomol Theater in Leningrad. He wrote his second play, "A Lad from Our Town", in 1941.  Studying war correspondence at the Lenin Military-Political Academy, Simonov obtained the service rank of quartermaster of the second rank. At the beginning of World War II Simonov received a job with the official army newspaper "Krasnaya Zvezda". Simonov rose through the army ranks becoming a senior battalion commissar in 1942, lieutenant colonel in 1943, and a colonel after the war.  During the war years, he wrote the plays "Russian People", "Wait for Me", "So It Will Be", the short novel "Days and Nights", and two books of poems, "With You and Without You" and "War". His poem "Wait for Me", about a soldier in the war asking his beloved to wait for his return, remains one of the best-known poems in Russian literature. The poem was addressed to his future wife, the actress Valentina Serova. Many of his poems for Valentina were included in the book "With You and Without You".  As a war correspondent, Simonov served in Romania, Bulgaria, Yugoslavia, Poland, and Germany, where he was present at the Battle of Berlin. After the war his collected reports appeared in "Letters from Czechoslovakia", "Slav Friendship", "Yugoslavian Notebook" and "From the Black to the Barents Sea: Notes of a War Correspondent".

Post-war works.

For three years after the war ended, Simonov served in foreign missions in Japan, the United States and China. From 1958 to 1960 he worked in Tashkent as the Central Asia correspondent for Pravda. His novel "Comrades in Arms" was published in 1952, and his longer novel, "The Living and the Dead", in 1959. In 1961 his play, "The Fourth," was performed at the Sovremennik Theatre. In 1963–64 he wrote the novel "Soldatami ne rozhdaiutsia", which can be translated as "Soldiers Are Made, Not Born" or "One Isn't Born a Soldier." In 1970–71 he wrote a continuation, "The Last Summer".  For two spells, 1946–50 and 1954–58, Simonov was editor in chief of the journal "Novy Mir". From 1950 through 1953, he was editor in chief of the "Literary Gazette"; from 1946 through 1959 and from 1967 through 1979, secretary of the Union of Writers of the USSR. In the year before his death, Simonov tried to create a special archive of memories of soldiers in the archives of the Defense Ministry in Podolsk, Moscow Region, but leaders of the army, in the high echelons, blocked the idea. Simonov died on 28 August 1979 in Moscow. According to his last will, he was cremated, and his ashes were scattered in Buynichi fields near Mogilev. In 1941 he was impressed by Soviet resistance in this place, during which 39 German tanks have been destroyed in one day, and described this episode in the "Dead and Alive" novel.  He is the central character in Orlando Figes' book "The Whisperers" (2007).

Film adaptations of Simonov's works.

Numerous films were released in the Soviet Union on Simonov's scenarios and based on his works:

Konstantin Mikhailovich Simonov, born Kirill (, – 28 August 1979), was a Soviet author and a war poet. He was a playwright and a wartime correspondent, most famous for his poem "Wait for Me".

Konstantin (Kirill) Michailowitsch Simonow (, wiss. Transliteration ""; * in Petrograd; † 28. August 1979 in Moskau) war ein sowjetischer Schriftsteller, Lyriker und Kriegsberichterstatter.


Effects.

Protection of those without immunity.

Some individuals either cannot develop immunity after vaccination or for medical reasons cannot be vaccinated. Newborn infants are too young to receive many vaccines, either for safety reasons or because passive immunity renders the vaccine ineffective. Individuals who are immunodeficient due to HIV/AIDS, lymphoma, leukemia, bone marrow cancer, an impaired spleen, chemotherapy, or radiotherapy may have lost any immunity that they previously had and vaccines may not be of any use for them because of their immunodeficiency.  A portion of those vaccinated may not develop long-term immunity. Vaccine contraindications may prevent certain individuals from being vaccinated. In addition to not being immune, individuals in one of these groups may be at a greater risk of developing complications from infection because of their medical status, but they may still be protected if a large enough percentage of the population is immune.  High levels of immunity in one age group can create herd immunity for other age groups. Vaccinating adults against pertussis reduces pertussis incidence in infants too young to be vaccinated, who are at the greatest risk of complications from the disease. This is especially important for close family members, who account for most of the transmissions to young infants. In the same manner, children receiving vaccines against pneumococcus reduces pneumococcal disease incidence among younger, unvaccinated siblings. Vaccinating children against pneumococcus and rotavirus has had the effect of reducing pneumococcus- and rotavirus-attributable hospitalizations for older children and adults, who do not normally receive these vaccines. Influenza (flu) is more severe in the elderly than in younger age groups, but influenza vaccines lack effectiveness in this demographic due to a waning of the immune system with age. The prioritization of school-age children for seasonal flu immunization, which is more effective than vaccinating the elderly, however, has been shown to create a certain degree of protection for the elderly.  For sexually transmitted infections (STIs), high levels of immunity in one sex induces herd immunity for both sexes. Vaccines against STIs that are targeted at one sex result in significant declines in STIs in both sexes if vaccine uptake in the target sex is high. Herd immunity from female vaccination does not, however, extend to homosexual males. If vaccine uptake among the target sex is low, then the other sex may need to be immunized so that the target sex can be sufficiently protected. High-risk behaviors make eliminating STIs difficult since even though most infections occur among individuals with moderate risk, the majority of transmissions occur because of individuals who engage in high-risk behaviors. For these reasons, in certain populations it may be necessary to immunize high-risk persons or individuals of both sexes to establish herd immunity.

Evolutionary pressure.

Herd immunity itself acts as an evolutionary pressure on certain viruses, influencing viral evolution by encouraging the production of novel strains, in this case referred to as escape mutants, that are able to "escape" from herd immunity and spread more easily. At the molecular level, viruses escape from herd immunity through antigenic drift, which is when mutations accumulate in the portion of the viral genome that encodes for the virus's surface antigen, typically a protein of the virus capsid, producing a change in the viral epitope. Alternatively, the reassortment of separate viral genome segments, or antigenic shift, which is more common when there are more strains in circulation, can also produce new serotypes. When either of these occur, memory T cells no longer recognize the virus, so people are not immune to the dominant circulating strain. For both influenza and norovirus, epidemics temporarily induce herd immunity until a new dominant strain emerges, causing successive waves of epidemics. As this evolution poses a challenge to herd immunity, broadly neutralizing antibodies and "universal" vaccines that can provide protection beyond a specific serotype are in development.

Serotype replacement.

Serotype replacement, or serotype shifting, may occur if the prevalence of a specific serotype declines due to high levels of immunity, allowing other serotypes to replace it. Initial vaccines against "Streptococcus pneumoniae" significantly reduced nasopharyngeal carriage of vaccine serotypes (VTs), including antibiotic-resistant types, only to be entirely offset by increased carriage of non-vaccine serotypes (NVTs). This did not result in a proportionate increase in disease incidence though, since NVTs were less invasive than VTs. Since then, pneumococcal vaccines that provide protection from the emerging serotypes have been introduced and have successfully countered their emergence. The possibility of future shifting remains, so further strategies to deal with this include expansion of VT coverage and the development of vaccines that use either killed whole-cells, which have more surface antigens, or proteins present in multiple serotypes.

Eradication of diseases.

If herd immunity has been established and maintained in a population for a sufficient time, the disease is inevitably eliminated—no more endemic transmissions occur. If elimination is achieved worldwide and the number of cases is permanently reduced to zero, then a disease can be declared eradicated. Eradication can thus be considered the final effect or end-result of public health initiatives to control the spread of infectious disease.  The benefits of eradication include ending all morbidity and mortality caused by the disease, financial savings for individuals, health care providers, and governments, and enabling resources used to control the disease to be used elsewhere. To date, two diseases have been eradicated using herd immunity and vaccination: rinderpest and smallpox. Eradication efforts that rely on herd immunity are currently underway for poliomyelitis, though civil unrest and distrust of modern medicine have made this difficult. Mandatory vaccination may be beneficial to eradication efforts if not enough people choose to get vaccinated.

Free riding.

Herd immunity is vulnerable to the free rider problem. Individuals who lack immunity, particularly those who choose not to vaccinate, free ride off the herd immunity created by those who are immune. As the number of free riders in a population increases, outbreaks of preventable diseases become more common and more severe due to loss of herd immunity. Individuals may choose to free ride for a variety of reasons, including the perceived ineffectiveness of a vaccine, believing that the risks associated with vaccines are greater than those associated with infection, mistrust of vaccines or public health officials, bandwagoning or groupthinking, social norms or peer pressure, and religious beliefs. Certain individuals are more likely to choose not to receive vaccines if vaccination rates are high enough so as to convince a person that he or she may not need to be vaccinated, since a sufficient percentage of others are already immune.

Mechanics.

Individuals who are immune to a disease act as a barrier in the spread of disease, slowing or preventing the transmission of disease to others. An individual's immunity can be acquired via a natural infection or through artificial means, such as vaccination. When a critical proportion of the population becomes immune, called the "herd immunity threshold" (HIT) or "herd immunity level" (HIL), the disease may no longer persist in the population, ceasing to be endemic.  The critical value, or threshold, in a given population, is the point where the disease reaches an endemic steady state, which means that the infection level is neither growing nor declining exponentially. This threshold can be calculated from the effective reproduction number "R", which is obtained by taking the product of the basic reproduction number "R", the average number of new infections caused by each case in an entirely susceptible population that is homogeneous, or well-mixed, meaning each individual can come into contact with every other susceptible individual in the population, and "S", the proportion of the population who are susceptible to infection, and setting this product to be equal to 1:  "S" can be rewritten as (1 − "p"), where "p" is the proportion of the population that is immune so that "p" + "S" equals one. Then, the equation can be rearranged to place "p" by itself as follows:  With "p" being by itself on the left side of the equation, it can be renamed as "p", representing the critical proportion of the population needed to be immune to stop the transmission of disease, which is the same as the "herd immunity threshold" HIT. "R" functions as a measure of contagiousness, so low "R" values are associated with lower HITs, whereas higher "R"s result in higher HITs. For example, the HIT for a disease with an "R" of 2 is theoretically only 50%, whereas a disease with an "R" of 10 the theoretical HIT is 90%.  When the effective reproduction number "R" of a contagious disease is reduced to and sustained below 1 new individual per infection, the number of cases occurring in the population gradually decreases until the disease has been eliminated. If a population is immune to a disease in excess of that disease's HIT, the number of cases reduces at a faster rate, outbreaks are even less likely to happen, and outbreaks that occur are smaller than they would be otherwise. If the effective reproduction number increases to above 1, then the disease is neither in a steady state nor decreasing in incidence, but is actively spreading through the population and infecting a larger number of people than usual.  An assumption in these calculations is that populations are homogeneous, or well-mixed, meaning that every individual comes into contact with every other individual, when in reality populations are better described as social networks as individuals tend to cluster together, remaining in relatively close contact with a limited number of other individuals. In these networks, transmission only occurs between those who are geographically or physically close to one another. The shape and size of a network is likely to alter a disease's HIT, making incidence either more or less common.  In heterogeneous populations, "R" is considered to be a measure of the number of cases generated by a "typical" infectious person, which depends on how individuals within a network interact with each other. Interactions within networks are more common than between networks, in which case the most highly connected networks transmit disease more easily, resulting in a higher "R" and a higher HIT than would be required in a less connected network. In networks that either opt not to become immune or are not immunized sufficiently, diseases may persist despite not existing in better-immunized networks.

Overshoot.

The cumulative proportion of individuals who get infected during the course of a disease outbreak can exceed the HIT. This is because the HIT does not represent the point at which the disease stops spreading, but rather the point at which each infected person infects fewer than one additional person on average. When the HIT is reached, the number of additional infections begins to taper off, but it does not immediately drop to zero. The difference between the cumulative proportion of infected individuals and the theoretical HIT is known as the overshoot.

Boosts.

Vaccination.

The primary way to boost levels of immunity in a population is through vaccination. Vaccination is originally based on the observation that milkmaids exposed to cowpox were immune to smallpox, so the practice of inoculating people with the cowpox virus began as a way to prevent smallpox. Well-developed vaccines provide protection in a far safer way than natural infections, as vaccines generally do not cause the diseases they protect against and severe adverse effects are significantly less common than complications from natural infections.  The immune system does not distinguish between natural infections and vaccines, forming an active response to both, so immunity induced via vaccination is similar to what would have occurred from contracting and recovering from the disease. To achieve herd immunity through vaccination, vaccine manufacturers aim to produce vaccines with low failure rates, and policy makers aim to encourage their use. After the successful introduction and widespread use of a vaccine, sharp declines in the incidence of diseases it protects against can be observed, which decreases the number of hospitalizations and deaths caused by such diseases.  Assuming a vaccine is 100% effective, then the equation used for calculating the herd immunity threshold can be used for calculating the vaccination level needed to eliminate a disease, written as "V". Vaccines are usually imperfect however, so the effectiveness, "E", of a vaccine must be accounted for:  From this equation, it can be observed that if "E" is less than (1 − 1/"R"), then it is impossible to eliminate a disease, even if the entire population is vaccinated. Similarly, waning vaccine-induced immunity, as occurs with acellular pertussis vaccines, requires higher levels of booster vaccination to sustain herd immunity. If a disease has ceased to be endemic to a population, then natural infections no longer contribute to a reduction in the fraction of the population that is susceptible. Only vaccination contributes to this reduction. The relation between vaccine coverage and effectiveness and disease incidence can be shown by subtracting the product of the effectiveness of a vaccine and the proportion of the population that is vaccinated, "p", from the herd immunity threshold equation as follows:  It can be observed from this equation that, all other things being equal (""ceteris paribus""), any increase in either vaccine coverage or vaccine effectiveness, including any increase in excess of a disease's HIT, further reduces the number of cases of a disease. The rate of decline in cases depends on a disease's "R", with diseases with lower "R" values experiencing sharper declines.  Vaccines usually have at least one contraindication for a specific population for medical reasons, but if both effectiveness and coverage are high enough herd immunity can protect these individuals. Vaccine effectiveness is often, but not always, adversely affected by passive immunity, so additional doses are recommended for some vaccines while others are not administered until after an individual has lost his or her passive immunity.

Passive immunity.

Individual immunity can also be gained passively, when antibodies to a pathogen are transferred from one individual to another. This can occur naturally, whereby maternal antibodies, primarily immunoglobulin G antibodies, are transferred across the placenta and in colostrum to fetuses and newborns. Passive immunity can also be gained artificially, when a susceptible person is injected with antibodies from the serum or plasma of an immune person.  Protection generated from passive immunity is immediate, but wanes over the course of weeks to months, so any contribution to herd immunity is temporary. For diseases that are especially severe among fetuses and newborns, such as influenza and tetanus, pregnant women may be immunized in order to transfer antibodies to the child. In the same way, high-risk groups that are either more likely to experience infection, or are more likely to develop complications from infection, may receive antibody preparations to prevent these infections or to reduce the severity of symptoms.

Cost–benefit analysis.

Herd immunity is often accounted for when conducting cost–benefit analyses of vaccination programs. It is regarded as a positive externality of high levels of immunity, producing an additional benefit of disease reduction that would not occur had no herd immunity been generated in the population. Therefore, herd immunity's inclusion in cost–benefit analyses results both in more favorable cost-effectiveness or cost–benefit ratios, and an increase in the number of disease cases averted by vaccination. Study designs done to estimate herd immunity's benefit include recording disease incidence in households with a vaccinated member, randomizing a population in a single geographic area to be vaccinated or not, and observing the incidence of disease before and after beginning a vaccination program. From these, it can be observed that disease incidence may decrease to a level beyond what can be predicted from direct protection alone, indicating that herd immunity contributed to the reduction. When serotype replacement is accounted for, it reduces the predicted benefits of vaccination.

History.

Herd immunity was first recognized as a naturally occurring phenomenon in the 1930s when A. W. Hedrich published research on the epidemiology of measles in Baltimore, and took notice that after many children had become immune to measles, the number of new infections temporarily decreased, including among susceptible children. In spite of this knowledge, efforts to control and eliminate measles were unsuccessful until mass vaccination using the measles vaccine began in the 1960s. Mass vaccination, discussions of disease eradication, and cost–benefit analyses of vaccination subsequently prompted more widespread use of the term "herd immunity". In the 1970s, the theorem used to calculate a disease's herd immunity threshold was developed. During the smallpox eradication campaign in the 1960s and 1970s, the practice of "ring vaccination", of which herd immunity is integral to, began as a way to immunize every person in a "ring" around an infected individual to prevent outbreaks from spreading.  Since the adoption of mass and ring vaccination, complexities and challenges to herd immunity have arisen. Modeling of the spread of infectious disease originally made a number of assumptions, namely that entire populations are susceptible and well-mixed, which do not exist in reality, so more precise equations have been developed. In recent decades, it has been recognized that the dominant strain of a microorganism in circulation may change due to herd immunity, either because of herd immunity acting as an evolutionary pressure or because herd immunity against one strain allowed another already-existing strain to spread. Emerging or ongoing fears and controversies about vaccination have reduced or eliminated herd immunity in certain communities, allowing preventable diseases to persist in or return to these communities.

Herd immunity (also called herd effect, community immunity, population immunity, or social immunity) is a form of indirect protection from infectious disease that occurs when a large percentage of a population has become immune to an infection, whether through vaccination or previous infections, thereby providing a measure of protection for individuals who are not immune. In a population in which a large proportion of individuals possess immunity, such people being unlikely to contribute to disease transmission, chains of infection are more likely to be disrupted, which either stops or slows the spread of disease. The greater the proportion of immune individuals in a community, the smaller the probability that non-immune individuals will come into contact with an infectious individual, helping to shield non-immune individuals from infection. Individuals can become immune by recovering from an earlier infection or through vaccination. Some individuals cannot become immune because of medical conditions, such as an immunodeficiency or immunosuppression, and for this group herd immunity is a crucial method of protection. Once a certain threshold has been reached, herd immunity gradually eliminates a disease from a population. This elimination, if achieved worldwide, may result in the permanent reduction in the number of infections to zero, called eradication. Herd immunity created via vaccination contributed to the eventual eradication of smallpox in 1977 and has contributed to the reduction of the frequencies of other diseases. Herd immunity does not apply to all diseases, just those that are contagious, meaning that they can be transmitted from one individual to another. Tetanus, for example, is infectious but not contagious, so herd immunity does not apply. Herd immunity was recognized as a naturally occurring phenomenon in the 1930s when it was observed that after a significant number of children had become immune to measles, the number of new infections temporarily decreased, including among susceptible children. Mass vaccination to induce herd immunity has since become common and proved successful in preventing the spread of many infectious diseases. Opposition to vaccination has posed a challenge to herd immunity, allowing preventable diseases to persist in or return to communities that have inadequate vaccination rates.

Herdenimmunität (von ) bezeichnet in der Epidemiologie eine indirekte Form des Schutzes vor einer ansteckenden Krankheit, der entsteht, wenn ein hoher Prozentsatz einer Population bereits immun geworden ist – sei es durch Infektion oder durch Impfung –, sodass sich die Ausbreitungsmöglichkeiten des Erregers innerhalb der Population insgesamt vermindern. Daraus ergibt sich indirekt ein erhöhter Schutz auch für die nicht-immunen Individuen. Der Begriff ist deutlich zu unterscheiden von dem der individuellen Immunität.


Location.

The contest took place in Stockholm, the capital and largest city of Sweden, which has long been one of the country's cultural, media, political, and economic centres as well as the most populated urban area in Scandinavia.  The venue for the contest was Stockholmsmässan (or "Stockholm International Fairs" in English). The main building is in Älvsjö – a southern suburb of Stockholm Municipality for which the building got its nickname. It was constructed in 1971 and holds 4,000 people.

Format.

This year a new scoring system was implemented. Each country would be represented by a jury of 11 members, at least half of whom had to be under the age of 26. Each jury member had to award every song a mark of between 1 and 5 points, but could not vote for their own nation's entry. The votes were cast immediately after the song was performed and collected by the adjudicator straight away. After the last song was performed, the jury secretary added up all the votes cast and awarded 12 points to the song with the highest score, 10 to the second highest score, then 8 to the third, 7 to the fourth, 6 to the fifth and so forth down to 1 point for the song ranked 10th, a points system that remains in use today. The jury spokesperson then announced the ten scores in the order the songs were presented when called upon by the hostess. The hostess Karin Falck several times confused the new system with questions like ""How much is seven in France?""  Unlike today, the points were not given in order (from 1 up to 12), but in the order the songs were performed. The current procedure of announcing the scores in ascending order, beginning with 1 point, was not established until 1980. This scoring system remained in use until 1996, although the number of jurors varied (it was 11 from 1975 to 1987, and 16 from 1988 to 1997) and the scores they awarded each song increased to 10 rather than 5. In from 1997, some juries were replaced by televotes and from 1998, all countries were encouraged to televote when possible.  In the 2009 final and the 2010 semi-finals, the juries were reintroduced to provide 50% of the scores. Despite these changes in how the points were decided, the 'douze points' scoring system remained in place from 1975–2015. In 2016 it was altered to each country providing two separate sets of points, however, modelled after the former model.

Participating countries.

Nineteen countries took part; Greece decided not to enter after its 1974 debut, while Turkey made its debut, and France and Malta returned to the contest.  The Portuguese entry "Madrugada" was an unabashed celebration of the Carnation Revolution, during which the country's 1974 Eurovision entry had played a pivotal practical role. According to author and historian John Kennedy O'Connor in his book "The Eurovision Song Contest – The Official History", the Portuguese performer had to be dissuaded from wearing his Portuguese army uniform and carrying a gun onto the stage. Some competitors (notably Portugal and Yugoslavia) opted to perform their songs in English for the rehearsals heard by the judges, but in their native tongue at the final. Others, such as Belgium and Germany, opted for a mix of their own language and English.

Conductors.

Each performance had a conductor who conducted the orchestra.

Returning artists.

Norway's Ellen Nikolaysen was one of the only two participants to return to the contest this year. Ellen's previous participation was with the band Bendik Singers in 1973. The second was John Farrar, one of The Shadows member who appeared as a backing guitarist and vocalist for Cliff Richard in 1973.

Scoreboard.

12 points.

Below is a summary of all 12 points in the final:

International broadcasts and voting.

The table below shows the order in which votes were cast during the 1975 contest along with the spokesperson who was responsible for announcing the votes for their respective country. Each national broadcaster [with the exception of Israel] also sent a commentator to the contest, in order to provide coverage of the contest in their own native language. Details of the commentators and the broadcasting station for which they represented are also included in the table below.

Notable incidents.

Intelligence reports at the time pointed out the festival as a possible target for a terrorist attack by the Red Army Faction which forced the organizers to tighten security considerably. The attack struck the West German embassy in Stockholm instead about a month later (see "West German embassy siege").  The Swedish left movement protested against the contest and its commercial aspect. At first the criticism was directed towards SR for the huge amount of money they spent on the contest but soon the protests developed into a movement against commercial music overall. When the Eurovision Song Contest took place an alternative festival was organized in another part of Stockholm where anybody who wanted could perform a song. Most popular became Sillstryparn's entry "Doing the omoralisk schlagerfestival" "(Doing the immoral Eurovision festival)". In the autumn of 1975 SR informed that Sweden would not participate in the 1976 edition of the Eurovision Song Contest due to the high costs that came with hosting the show. The rules later changed so that the costs were split more equally between the participating broadcasters. In the end, SR did not broadcast the 1976 Contest.  Swedish TV technicians refused to broadcast the festival to Chile, where Televisión Nacional de Chile had plans to air it. The refusal was in protest to the military dictatorship that has been ruling the country since the 1973 Chilean coup d'etat led by Augusto Pinochet.

The Eurovision Song Contest 1975 was the 20th edition of the annual Eurovision Song Contest. It took place in Stockholm, Sweden, following ABBA's win at the 1974 contest in Brighton, United Kingdom with the song "Waterloo". It was the first time the contest took place in Sweden, also marking the first time the Scandinavian Peninsula hosted the event. The contest was held at Stockholmsmässan on Saturday 22 March 1975. The show was hosted by Karin Falck.

Der 20. Eurovision Song Contest fand am 22. März 1975 in Stockholm statt, nachdem im Jahr zuvor die Gruppe ABBA gewonnen hatte. Es moderierte Karin Falck. Gewinner war die Gruppe Teach-In, die für die Niederlande mit ihrem Lied "Ding-a-dong" startete.


Early life.

Taco Ockerse, born in Jakarta, Indonesia, on July 21, 1955, had spent many of his childhood years moving around the world, residing in the Netherlands, the United States, Singapore, Luxembourg, Belgium, and Germany. He attended the International School of Brussels, Belgium, and graduated in 1973. Afterward, he studied interior decoration and finished acting school in Hamburg. He held lead roles in numerous school productions, including "You're a Good Man, Charlie Brown"; "Carousel"; "The Fantasticks"; and "Fiddler on the Roof".  In 1975, he began his first professional theatrical engagements in Hamburg. This included roles in "Children's Theater", and roles as an ensemble member of the Thalia Theater in a number of plays, including "Sweet Charity", "Chicago", and "Three Musketeers". He also directed and choreographed for the musical "Nightchild". In 1979, he played "Chino" in John Neumeier's "West Side Story" at Hamburg Opera House. He founded his first band, Taco's Bizz, in 1979.

Professional career.

In 1981, Taco signed his first record contract with Polydor in West Germany for two record releases, whereon he released his first single, "Puttin' On the Ritz", which in 1982 was issued by RCA Records for US release. His version of the song also had pieces of other Irving Berlin songs, such as "White Christmas". The single was widely played throughout the US by late summer of 1983 eventually peaking at No. 4 in September 1983 on the Hot 100 as well as No. 1 on "Cashbox". Although the single eventually earned him a Gold-certification for selling over one million copies, it was Taco's only Top 40 hit in the US. In 1983 and 1984, he toured extensively throughout Europe. While the single "Puttin' on the Ritz" topped the charts in Sweden and New Zealand, it entered the Top 5 in numerous countries including Norway, Austria, and Canada. His subsequent album, "After Eight", was released in over 40 countries and managed to reach No. 4 in Norway, No. 5 in Canada, No. 11 in Austria, No. 17 in New Zealand, No. 23 in the United States, and No. 59 in Germany. The album earned Taco a number of Gold certifications including one in Finland for selling over 25,000 copies.  Taco's second single "Singing in the Rain" was a moderate success peaking at No. 49 in Germany, No. 46 in Canada, and No. 98 in the UK.  He appeared as a guest on "The Merv Griffin Show", "Alan Thicke", "Solid Gold", "Good Morning America", a Bob Hope TV special, and many other TV shows while touring.  Taco's follow-up album, "Let's Face the Music", was recorded in 1984 for Polydor, which peaked at No. 58 in his home of West Germany and managed to enter the Top 100 in Canada peaking at No. 92. Taco continued to record, focusing mostly on the German market with albums "Swing Classics/In the Mood of Glenn Miller" in 1985 and "Tell Me That You Like It" in 1986 for Polydor. In 1987 he recorded the self-titled album "Taco".  In 1989, he briefly flirted with contemporary dance music by releasing a pair of singles, "Love Touch" and "Got to Be Your Lover", that were styled after the high energy disco sound popularized by Stock Aitken Waterman. Afterwards, he repositioned himself as a swing/soul singer. He has collaborated with Geff Harrison of Kin Ping Meh fame.  Between 1989 and 1996, Taco worked as an actor. He had television acting roles in "Friedrichstadt Palast" and "Das Erbe der Guldenburgs", and an appearance in the film "Karniggels". He also appeared as "Chico" in the theater production of "Marx Brothers Radio Show", and played lead roles in "Shakespeare Rock n Roll" in Berlin and "Shakespeare as We Like It" in Austria.  He currently resides in Germany, performing with his band and as a gala artist.  On October 11, 2009, the first channel of Russian TV, 1TV, filmed the program "Songs of the 20th Century". Taco appears with "Puttin' On the Ritz" in the sequence about the 1930s. The show was broadcast in January 2010. On November 27, 2009 he performed "Puttin' On the Ritz" and "Singin' in the Rain" at the Olympic Stadium in Moscow, Russia. Furthermore, he was the star guest in the "New Year's Eve Show 2009" of Russian TV, which had about 84 million viewers in more than 20 countries.  In July 2010, Cleopatra Records Los Angeles released an entirely new re-recording of "Puttin' On the Ritz". Taco's vocals were recorded in Germany and the backing tracks with top studio musicians in their studio in L.A.  On March 1, 2011, DingDing Music released the original song "Timeless Love" that was written and produced by Edgar Rothermich and Matthias Muentefering in the late 1980s. The studio recording that Taco performed as a duet with the singer Rozaa Wortham in Berlin was remixed in late 2010 in the U.S. and is now available for download.  On March 11, 2011, RTL Germany broadcast "The Ultimate Chartshow - the most successful Evergreens of all time", where he appeared with "Puttin' On The Ritz".  In mid 2019, Taco created his own personal Facebook page, where his fans can interact with him on a personal level. As of January 2020 the page has over 3,000 friends and followers.

Taco Ockerse (born July 21, 1955), known mononymously as Taco, is an Indonesian-born Dutch singer and entertainer who started his career in Germany.

Taco Ockerse (* 21. Juli 1955 in Jakarta) ist ein niederländischer Popsänger, der durch seine Coverversion des Irving-Berlin-Hits "Puttin’ on the Ritz" bekannt geworden ist.


Life.

Lipski trained as a lawyer, and joined the Polish Ministry of Foreign Affairs in 1925. From 29 October 1934 to 1 September 1939, Lipski served as the Polish ambassador to Germany. One of his first assignments in 1934 was to work on the German–Polish Non-Aggression Pact, to try and secure the border to the east in light of Poland's isolation and the build up in both Communist Russia and Germany itself.  In late 1938, German officials approached Poland with a suggestion to resettle European Jews to Africa, inspired by the British Uganda Scheme and the Franco-Polish Madagascar Plan, and Lipski as the Polish ambassador to Germany discussed the matter with Hitler. Yohanan Cohen describes Lipski's discussion with Hitler, which took place on 21 October 1938, as "characteristic of the kinds of things that had come to dominate the Polish establishment and public were comments by Jósef Lipski." Responding to Hitler's suggestions, Lipski said that "if he can find such a solution we will erect him a beautiful monument in Warsaw". Timothy Snyder stated that "historians of these negotiations often quote Lipski's remark that Poland would build a monument to Hitler if he found a way to resolve the Jewish question. With knowledge of the Holocaust we can find this remark even more revolting than it, in fact, was. Lipski was expressing the hope that despite the overwhelming difficulties, Germany could induce some maritime power to open some overseas colony to Polish Jews. It never occurred to him that Hitler's'resolution' could be total mass murder."  On 24 October 1938, Lipski met with German Foreign Minister Joachim von Ribbentrop at Hitler's mountain retreat in Berchtesgaden. Ribbentrop demanded that Poland agree to the German annexation of the Free City of Danzig; Lipski refused. According to British historian A. J. P. Taylor, just days before the German invasion of Poland, Lipski refused to get out of bed, despite the urging of British diplomats, to meet with von Ribbentrop to hear Germany's latest demands of Poland, illustrating the Polish response to the aggressive German diplomacy. Under British pressure to negotiate a solution to the Danzig crisis, Lipski eventually phoned to ask for an interview with Ribbentrop on 31 August 1939 - the day before the invasion - but when learning that Lipski would only be present as an ambassador, rather than as a plenipotentiary, the meeting was refused. According to Taylor, the Germans were aware of Lipski's limited negotiating authority.  During the Second World War, Lipski fought as a volunteer (Polish 1st Grenadiers Division in France) and later joined the General Staff of the Polish Armed Forces in the West. In 1951 Lipski moved to the USA and represented the Polish Government in Exile.

Statement by Vladimir Putin.

In December 2019, during a speech given to high ranking Russian defense officials, Russian President Vladimir Putin accused Lipski of antisemitism, calling him "That bastard! That anti-Semitic pig." The remarks were condemned by Polish government officials, and Poland's Chief Rabbi, Michael Schudrich, stated that "for us Jews, it is particularly outrageous for Putin to manipulate the tone of [Lipski's comments] made in his conversation with Adolf Hitler in 1938. One shouldn't forget Poland supported the emigration of its 10 percent Jewish minority, but it did so partly in cooperation with the Zionist movement, to which it gave clandestine military support. At the same time, however, when the Third Reich expelled thousands of Polish Jews in 1938, Polish diplomatic services, including Ambassador Lipski personally, assisted them. Accusing [Lipski] of antisemitism on the basis of one sentence taken out of context is extremely irresponsible."  Professor stated that "[Lipski's] extensive legacy... has no traces of antisemitic attitude. Lipski was not an antisemite."

Józef Lipski (5 June 1894 – 1 November 1958) was a Polish diplomat and Ambassador to Nazi Germany from 1934 to 1939. Lipski played a key role in the foreign policy of the Second Polish Republic.

Józef Lipski (* 5. Juni 1894 in Breslau; † 1. November 1958 in Washington, D.C.) war ein polnischer Politiker und Diplomat.


Background.

During both World Wars, the island of Britain was dependent upon huge numbers of merchant ships to bring in food and essential raw materials, and protecting this lifeline was one of the highest priorities for British forces. If this lifeline could be severed, the British Empire in Europe would have to either sue for peace; negotiate an armistice; or abandon the British Isles as a base of operations to blockade the sea approaches to Western Europe; giving Germany in effect, complete mastery of Western Europe, with no tactical base in Europe to oppose that control.  Germany's naval leadership (under Admiral Erich Johann Albert Raeder) at the time firmly believed that defeat by blockade was achievable. However, they also believed that the primary method to achieve this objective was to use traditional commerce raiding tactics, founded upon surface combatants (cruisers, battle-cruisers, fast battleships) that were only "supported" by submarines. Regardless of the method or manner, Raeder convinced the High Command (OKW) and Hitler that if this lifeline were severed, Britain should be defeated, regardless of any other factors.  Operation Rheinübung was the latest in a series of raids on Allied shipping carried out by surface units of the "Kriegsmarine". It was preceded by Operation Berlin, a highly successful sortie by and which ended in March 1941.  By May 1941, the "Kriegsmarine" battleships "Scharnhorst" and "Gneisenau" were at Brest, on the western coast of France, posing a serious threat to the Atlantic convoys, and were heavily bombed by the Royal Air Force. The original plan was to have both ships involved in the operation, but "Scharnhorst" was undergoing heavy repairs to her engines, and "Gneisenau" had just suffered a damaging torpedo hit days before which put her out of action for 6 months. This left just two new warships available to the Germans: the battleship "Bismarck" and the heavy cruiser "Prinz Eugen" (while the "Kriegsmarine" had three serviceable light cruisers, none had the endurance necessary for a long Atlantic operation), both initially stationed in the Baltic Sea.  The aim of the operation was for "Bismarck" and "Prinz Eugen" to break into the Atlantic and attack Allied shipping. Grand Admiral Erich Raeder's orders to Admiral Günther Lütjens were that "the objective of the "Bismarck" is not to defeat enemies of equal strength, but to tie them down in a delaying action, while preserving her combat capacity as much as possible, so as to allow "Prinz Eugen" to get at the merchant ships in the convoy" and "The primary target in this operation is the enemy's merchant shipping; enemy warships will be engaged only when that objective makes it necessary and it can be done without excessive risk".  To support and provide facilities for the capital ships to refuel and reärm, German Naval Command (OKM) established a network of tankers and supply ships in the "Rheinübung" operational area. Seven tankers and two supply ships were sent as far afield as Labrador in the west and the Cape Verde Islands in the south.  Lütjens had requested that Raeder delay "Rheinübung" long enough either for "Scharnhorst" to complete repairs to her engines and be made combat-worthy and to rendezvous at sea with "Bismarck" and "Prinz Eugen" or for "Bismarck"s sister ship to accompany them. Raeder had refused, as "Scharnhorst" would not be ready until early July. The crew of the newly completed "Tirpitz" was not yet fully trained, and over Lütjens's protests Raeder ordered "Rheinübung" to go ahead. Raeder's principal reason for going ahead was his knowledge of the upcoming Operation Barbarossa, where the "Kriegsmarine" was going to play only a small, supporting role, and his desire to score a major success with a battleship before "Barbarossa" that might impress upon Hitler the need not to cut the budget for capital ships.  To meet the threat from German surface ships, the British had stationed at Scapa Flow the new battleships and as well as the battlecruiser and the newly commissioned aircraft carrier. Elsewhere, Force H at Gibraltar could muster the battlecruiser and the aircraft carrier ; at sea in the Atlantic on various duties were the battleships, and and the battlecruiser. Cruisers and air patrols provided the fleet's "eyes". At sea, or due to sail shortly, were 11 convoys, including a troop convoy.  OKM did not take into account the Royal Navy's determination to destroy the German surface fleet. To make sure that "Bismarck" was sunk, the Royal Navy would ruthlessly strip other theatres of action. This would include denuding valuable convoys of their escorts. The British would ultimately deploy six battleships, three battlecruisers, two aircraft carriers, 16 cruisers, 33 destroyers and eight submarines, along with patrol aircraft. It would become the largest naval force assigned to a single operation up to that point in the war.

"Bismarck" sails.

The heavy cruiser "Prinz Eugen" sailed at about 21:00 on 18 May 1941 from Gotenhafen (now Gdynia, Poland), followed at 2:00 am, 19 May, by "Bismarck". Both ships proceeded under escort, separately and rendezvoused off Cape Arkona on Rügen Island in the western Baltic. They then proceeded through the Danish Islands into the Kattegat. Entering the Kattegat on 20 May "Bismarck" and "Prinz Eugen" sailed north toward the Skagerrak, the strait between Jutland and Southern Norway where they were sighted by the Swedish aircraft-carrying cruiser on around 1:00 pm. "Gotland" forwarded the sighting in a routine report.  On 21 May the Admiralty was alerted by sources in the Swedish government that two large German warships had been seen in the Kattegat. The ships entered the North Sea and took a brief refuge in a Grimstadfjord near Bergen, Norway on 21 May where "Prinz Eugen" was topped off with fuel, making a break for the Atlantic shipping lanes on 22 May. By this time, "Hood" and "Prince of Wales", with escorting destroyers, were en route to the Denmark Strait, where two cruisers, and were already patrolling. The cruisers and had been sent to guard the waters south-east of Iceland.  Once the departure of the German ships was discovered, Admiral Sir John Tovey, the Commander-in-Chief of the British Home Fleet, sailed with "King George V", "Victorious" and their escorts to support those already at sea. "Repulse" joined soon afterwards.  On the evening of 23 May, "Suffolk" sighted "Bismarck" and "Prinz Eugen" in the Denmark Strait, close to the Greenland coast. "Suffolk" immediately sought cover in a fog bank and The Admiralty was alerted. "Bismarck" opened fire on "Norfolk" at a range of six miles but "Norfolk" escaped into fog. "Norfolk" and "Suffolk", outgunned, shadowed the German ships using radar. No hits were scored but the concussion of the main guns firing at "Norfolk" had knocked out "Bismarck"'s radar causing Lütjens to re-position "Prinz Eugen" ahead of "Bismarck". After the German ships were sighted, British naval groups were redirected to either intercept Lütjens' force or to cover a troop convoy.

Battle of the Denmark Strait.

"Hood" and "Prince of Wales" made contact with the German force early on the morning of 24 May, and the action started at 5:52 am, with the combatants about apart. Gunners on both British ships initially mistook "Prinz Eugen" that was now in the lead for "Bismarck" and targeted her. Both German ships were firing at "Hood". "Hood" suffered an early hit from "Prinz Eugen" which started a rapidly spreading fire amidships.  Then, at about 6 am, one or more of "Hood"'s magazines exploded, probably as the result of a direct hit by a shell from "Bismarck". The massive explosion broke the great battlecruiser's back, and she sank within minutes. All but three of her 1,417-man crew died, including Rear Admiral Lancelot Holland, commanding officer of the squadron.  "Prince of Wales" continued the action, but suffered multiple hits with and shells, and experienced repeated mechanical failures with her main armament. Her commanding officer, Captain Leach, was wounded when one of "Bismarcks shells struck "Prince of Wales bridge. Leach broke off the action, and the British battleship retreated under cover of a smokescreen.  "Bismarck" had been hit only two (or perhaps three) times but Admiral Lütjens overruled "Bismarck"s Captain Ernst Lindemann who wanted to pursue the damaged "Prince of Wales" and finish her off. All of the hits on "Bismarck" had been inflicted by "Prince of Wales" guns. One of the hits had penetrated the German battleship's hull near the bow, rupturing some of her fuel tanks, causing her to leak oil continuously and at a serious rate. This was to be a critical factor as the pursuit continued, forcing "Bismarck" to make for Brest instead of escaping into the great expanse of the Atlantic. The resulting oil slick also helped the British cruisers to shadow her.

The Pursuit.

"Norfolk" and "Suffolk" and the damaged "Prince of Wales" continued to shadow the Germans, reporting their position to draw British forces to the scene. In response, it was decided that the undamaged "Prinz Eugen" would detach to continue raiding, while "Bismarck" drew off the pursuit. In conjunction with this, Admiral Dönitz committed the U-boat arm to support "Bismarck" with all available U-boats in the Atlantic. He organised two patrol lines to trap the Home Fleet should "Bismarck" lead her pursuers to them. One line of 7 boats was arrayed in mid-Atlantic while another, of 8 boats, was stationed west of the Bay of Biscay. At 6:40 pm on 24 May, "Bismarck" turned on her pursuers and briefly opened fire to cover the escape of "Prinz Eugen". The German cruiser slipped away undamaged.  At 10 pm, "Victorious" was away and launched an air attack with nine Fairey Swordfish torpedo bombers, which were guided in by "Norfolk". In poor weather, and against heavy fire, they attacked and made a single torpedo hit under the bridge. However, up against strong belt armour and anti-torpedo bulges, it failed to cause substantial damage. The attacking aircraft were all safely recovered by "Victorious", despite poor weather, darkness, aircrew inexperience and the failure of the carrier's homing beacon.  At 3 am on 25 May, the British shadowers lost contact with "Bismarck". At first, it was thought that she would return to the North Sea, and ships were directed accordingly. Then Lütjens, believing that he was still being shadowed by the British, broke radio silence by sending a long radio message to headquarters in Germany. This allowed the British to triangulate "Bismarck"'s approximate position and send aircraft to hunt for the German battleship. By the time that it was realised that Lütjens was heading for Brest, "Bismarck" had broken the naval cordon and gained a lead. By 11 pm, Lütjens was well to the east of Tovey's force and had managed to evade "Rodney". "Bismarck" was short of fuel due to the damaging hit inflicted by "Prince of Wales" which had caused Lütjens to reduce speed to conserve fuel but "Bismarck" still had enough speed to outrun the heavy units of the Home Fleet and reach the safety of France. From the south, however, Somerville's Force H with the carrier "Ark Royal", the battlecruiser "Renown", and the light cruiser were approaching to intercept.  The British ships were also beginning to run low on fuel, and the escape of "Bismarck" seemed more and more certain. However, at 10:30 am on 26 May, a PBY Catalina flying-boat, based at Lough Erne, Northern Ireland, found "Bismarck". She was from Brest and not within range of "Luftwaffe" air cover. This contact was taken over by two Swordfish from "Ark Royal". This carrier now launched an airstrike, but her aircrew were unaware of "Sheffield"'s proximity to "Bismarck", mistook the British cruiser for the German battleship and therefore immediately attacked her. Their torpedoes had been fitted with influence detonators, and several of them exploded prematurely. Others missed their target, and the attacking aircraft then received a warning from "Ark Royal" that "Sheffield" was in the vicinity, whereupon the Swordfish finally recognised the cruiser and broke off the attack.  "Ark Royal" now launched, in almost impossibly bad weather conditions for air operations, and from a distance of less than 40 miles upwind of "Bismarck", a second strike consisting of 15 Swordfish. These were carrying torpedoes equipped with the standard and reliable contact detonators. The attack resulted in two or three hits on the German ship, one of which inflicted critical damage on her steering. A jammed rudder now meant she could now only sail "away" from her intended destination of Brest. At midnight, Lütjens signalled his headquarters: "Ship unmanoeuvrable. We shall fight to the last shell. Long live the Führer."

"Bismarck"s end.

The battleships "Rodney" and "King George V" waited for daylight on 27 May before attacking. At 8:47 am, they opened fire, quickly hitting "Bismarck". Her gunners achieved near misses on "Rodney", but the British ships had silenced most of the German guns within half an hour. Despite close-range shelling by "Rodney", a list to port and widespread fires, "Bismarck" did not sink.  According to Ballard's underwater surveys in recent years the British guns achieved only four penetrations of "Bismarck"s armour, two through the upper armour belt on the starboard side from "King George V" and two on the port side from "Rodney". These four hits occurred at about 10:00 am, at close range, causing heavy casualties among the sheltering crew.  Nearly out of fuel – and mindful of possible U-boat attacks – the British battleships left for home. The heavy cruiser attacked with torpedoes and made three hits. Scuttling charges were soon set off by German sailors, and at 10:40 am, "Bismarck" capsized and sank. "Dorsetshire" and the destroyer rescued 110 survivors. After an hour, rescue work was abruptly ended when there were reports of a U-boat presence. Another five survivors were picked up by and the German weather ship. Over 2,000 died, including Captain Lindemann and Admiral Lütjens.

Aftermath.

After separating from "Bismarck", "Prinz Eugen" went further south into the Atlantic, intending to continue the commerce raiding mission. On 26 May, with just 160 tons of fuel left, she rendezvoused with the tanker "Spichern" and refuelled. On 27 May, she developed engine trouble, which worsened over the next few days. On 28 May, she received a further refueling from "Esso Hamburg". With her speed reduced to, it was no longer considered practicable to continue. She abandoned her commerce raiding mission without sinking any merchant ships, and made her way to Brest, arriving on 1 June where she remained under repair until the end of 1941. She later escaped from France with two other German battleships in the Channel Dash.  In the action, just two U-boats had sighted the British forces, and neither was able to attack. In the aftermath, the British ships were able to evade the patrol lines as they returned to base; there were no further U-boat contacts. The "Luftwaffe" also organized sorties against the Home Fleet, but none were successful until 28 May, when planes from "Kampfgeschwader" 77 attacked and sank the destroyer.  After "Rheinübung", the Royal Navy made a concerted effort to round up the network of supply ships deployed to refuel and rearm the "Rheinübung" ships. The first success came on 3 June, when the tanker "Belchen" was discovered by the cruisers and south of Greenland. On 4 June the tanker "Gedania" was found in mid-Atlantic by "Marsdale", while east the supply ship "Gonzenheim" was caught by the armed merchant cruiser, and aircraft from "Victorious". On the same day in the south Atlantic, midway between Belém and Freetown, the southern most limit of the "Rheinübung" operation, the tanker "Esso Hamburg" was intercepted by the cruiser ; while the following day "London", accompanied by, sank the tanker "Egerland". A week later, on 12 June, the tanker "Friederich Breme" was sunk by the cruiser "Sheffield" in the mid-Atlantic. On 15 June, the tanker "Lothringen" was sunk by the cruiser, with aircraft from. In just over two weeks, 7 of the 9 supply ships assigned to Operation Rheinübung had been accounted for, with serious consequences for future German surface operations.

Conclusion.

Operation Rheinübung was a failure, and although the Germans scored a success by sinking the old battlecruiser "HMS Hood", this was more than offset with the loss of the modern battleship "Bismarck", which represented one-quarter of the "Kriegsmarine"s capital ships. No merchant ships were sunk or even sighted by the German heavy surface units during the 2-week raid. Allied convoys were not seriously disrupted; most convoys sailed according to schedule, and there was no diminution of supplies to Britain. On the other hand, the Atlantic U-boat campaign was disrupted; boats in the Atlantic sank just 2 ships in the last weeks of May, compared to 29 at the beginning of the month. As a result of "Bismarck"s sinking, Hitler forbade any further Atlantic sorties, and her sister ship "Tirpitz" was sent to Norway. The "Kriegsmarine" was never again able to mount a major surface operation against Allied supply routes in the North Atlantic; henceforth its only weapon was the U-boat campaign.

Operation Rheinübung ("Exercise Rhine") was the sortie into the Atlantic by the new German battleship and heavy cruiser on 18–27 May 1941, during World War II. This operation to block Allied shipping to the United Kingdom culminated with the sinking of "Bismarck".

Das Unternehmen Rheinübung war eine Operation der deutschen Kriegsmarine im Seekrieg des Zweiten Weltkriegs. Die Operation sollte den Druck auf die Nachschubtransporte zu den britischen Inseln erhöhen und den U-Boot-Krieg unterstützen. Im Verlauf des Unternehmens wurden bei zwei Seegefechten der britische Schlachtkreuzer "HMS Hood" und das deutsche Schlachtschiff "Bismarck" versenkt.


Life.

Herophilos was born in Chalcedon in Asia Minor (now Kadiköy, Turkey), c. 335 BC. Not much is known about his early life other than he moved to Alexandria at a fairly young age to begin his schooling.  As an adult Herophilos was a teacher, and an author of at least nine texts ranging from his book titled, "On Pulses", which explored the flow of blood from the heart through the arteries, to his book titled "Midwifery", which discussed duration and phases of childbirth. In Alexandria, he practiced dissections, often publicly so that he could explain what he was doing to those who were fascinated. Erasistratus was his contemporary. Together, they worked at a medical school in Alexandria that is said to have drawn people from all over the ancient world due to Herophilos' fame.  His works are lost but were much quoted by Galen in the second century AD. Herophilos was the first scientist to systematically perform scientific dissections of human cadavers. Dissections of human cadavers were banned in most places at the time, except for Alexandria. Celsus in "De Medicina" and the church leader Tertullian state that he vivisected at least 600 live prisoners.  After the death of Herophilos in 280 BC, his anatomical findings lived on in the works of other important physicians, notably Galen. Even though dissections were performed in the following centuries and medieval times, only a few insights were added. Dissecting with the purpose to gain knowledge about human anatomy started again in early modern times (Vesalius), more than 1600 years after Herophilos' death.

Medicine.

He emphasised the use of the experimental method in medicine, for he considered it essential to found knowledge on empirical bases. He was a forerunner of the Empiric school of medicine, founded by Herophilos' pupil Philinus of Cos, which combined Herophilos' empirical impulses with critical tools borrowed from Pyrrhonist philosophy. However, the Empirics found Herophilos wanting, mounting two chief attacks against him:  Conventional medicine of the time revolved around the theory of the four humors in which an imbalance between bile, black bile, phlegm, and blood led to sickness or disease. Veins were believed to be filled with blood and a mixture of air and water. Through dissections, Herophilus was able to deduce that veins only carried blood. After studying the flow of blood, he was able to differentiate between arteries and veins. He noticed that as blood flowed through arteries, they pulsed or rhythmically throbbed. He worked out standards for measuring a pulse and could use these standards to aid him in diagnosing sicknesses or diseases. To measure this pulse, he made use of a water clock.  His work on blood and its movements led him to study and analyse the brain. He proposed that the brain housed the intellect rather than the heart. He was the first person to differentiate between the cerebrum and the cerebellum, and to place individual importance on each portion. He looked more in depth into the network of nerves located in the cranium. He described the optic nerve and the oculomotor nerve for sight and eye movement. Through his dissection of the eye, he discovered the different sections and layers of the eye: the cornea, the retina, the iris, and the choroid, also known as the choroid coat. Further study of the cranium led him to describe the "calamus scriptorius", which he believed was the seat of the human soul. Analysis of the nerves in the cranium allowed him to differentiate between nerves and blood vessels and to discover the differences between motor and sensory nerves. He believed that the sensory and motor nerves shot out from the brain and that the neural transmissions occurred by means of "pneuma". Part of his belief system regarding the human body involved the pneuma, which he believed was a substance that flowed through the arteries along with the blood. Playing off of medical beliefs at the time, Herophilos stated that diseases occurred when an excess of one of the four humors impeded the pneuma from reaching the brain.  Herophilos also introduced many of the scientific terms used to this day to describe anatomical phenomena. He was among the first to introduce the notion of conventional terminology, as opposed to use of "natural names", using terms he created to describe the objects of study, naming them for the first time. A confluence of sinuses in the skull was originally named "torcular Herophili" after him. Torcular is a Latin translation of Herophilos' label, "ληνός - lenos", 'wine vat' or 'wine press'. He also named the duodenum, which is part of the small intestine. Other areas of his anatomical study include the liver, the pancreas, and the alimentary tract, as well as the salivary glands and genitalia.  Herophilos is credited with learning extensively about the physiology of the female reproductive system. In his book "Midwifery", he discussed phases and duration of pregnancy as well as causes for difficult childbirth. The aim of this work was to help midwives and other doctors of the time more fully understand the process of procreation and pregnancy. He is also credited with the discovery of the ovum, and was the first to make a scientific description of what would later be called Skene's gland, and in 2001 was renamed the female prostate.  Herophilos believed that exercise and a healthy diet were integral to the bodily health of an individual. Herophilos once said that "when health is absent, wisdom cannot reveal itself, art cannot become manifest, strength cannot be exerted, wealth is useless, and reason is powerless".

Herophilos (; ; 335–280 BC), sometimes Latinised Herophilus, was a Greek physician deemed to be among the earliest anatomists. Born in Chalcedon, he spent the majority of his life in Alexandria. He was the first scientist to systematically perform scientific dissections of human cadavers. He recorded his findings in over nine works, which are now all lost. The early Christian author Tertullian states that Herophilos vivisected at least 600 live prisoners.

Herophilos von Chalkedon (auch "H. von Kalchedon" und "Herophilos von Alexandria"; * um 325 v. Chr.; † um 255 v. Chr.) war ein griechischer Arzt und Anatom, der in Alexandria lehrte. Herophilos, der als „Vater der Anatomie“ gilt, und der etwas jüngere Erasistratos waren die führenden Anatomen der alexandrinischen Schule.


Massacres during Second World War.

Wieszanów Massacre.

During the German Invasion of Poland in 1939, German soldiers conducted a number of massacres in the area. In the village of Wieszanów on 1 September 1939, 17 women and children (as young as 2 years old) were murdered en masse after two men were murdered by German soldiers. Women and children tried to hide themselves in cellars but were discovered by soldiers. Despite pleading to be allowed to get out, they were forced to stay as Germans threw down several grenades, murdering 14 women and children on the spot and wounding 3 of them. Several local men were later kidnapped and sent to German concentration camps. At least two were executed already on their way to the camps. A day later the same Germans who committed the murder came back and burned down 20 homes along with the livestock.

Torzeniec Massacre.

Several massacres were made by Germans in the village of Torzeniec. On 1 September 1939 Germans arrived during the night to the town, and started to set fire to barns and houses using bottles with gasoline and gun fire with incendiary bullets. Villagers who tried to escape their burning homes were gunned down by the Germans who behaved as they were making a hunt for animals. Eight people were murdered in this way alongside Barbara Pietrzak who tried to save her 2-year-old child. Another eight were burned alive in the cellar as their only escape route was blocked by a burning barn. The only member of the family left outside, 70-year-old Antoni Kubera was shot dead on his backyard by the Germans just as his family was burning alive in the cellar. On the same night all men from the village were gathered by the Germans, and every second one was led to a group that was executed in front of all the villagers. 18 men were murdered this way. A Polish woman(Maria Stambuła) who according to Germans refused to watch the murder was shot severely by the Germans as well. During the massacre a 40-year-old Józef Sadowski and a husband and father of several children pleaded to be exchanged for his 70-year-old father Stanisław Sadowski who was chosen by the Germans to be murdered. The Germans agreed and the son saved his father's life by sacrificing himself. Later during the night another massacre was made by the German soldiers. Four unidentified Polish PoWs were taken to the village and murdered. All together the cemetery in Wyszanów is the place of burial of 57 victims of German massacres.

Neighbouring counties.

Wieruszów County is bordered by Sieradz County to the north-east, Wieluń County to the east, Olesno County and Kluczbork County to the south, Kępno County to the west, and Ostrzeszów County to the north-west.

Administrative division.

The county is subdivided into seven gminas (one urban-rural and six rural). These are listed in the following table, in descending order of population.  <br

Wieruszów County () is a unit of territorial administration and local government (powiat) in Łódź Voivodeship, central Poland. It came into being on January 1, 1999, as a result of the Polish local government reforms passed in 1998. Its administrative seat and only town is Wieruszów, which lies south-west of the regional capital Łódź.

Der Powiat Wieruszowski ist ein Powiat ("Kreis") in der polnischen Woiwodschaft Łódź. Der Powiat hat eine Fläche von 576,22 km2, auf der 42.000 Einwohner leben.