Multinational Performance and the Geography of FDI:evidence from 46 countries

The literature on multinationality and firm performance has generally disregarded the role of geography. However, the location of FDI assumes particular importance in terms of the link between multinationality at the firm level. The purpose of this paper is to consider the multinationality-performance relationship within the context of greater emphasis on the importance of location, but also emphasising the importance of the location decision. This paper draws on firm-level data covering over 16,000 multinationals from 46 countries over the period of 1997-2007 and allows for different effects upon the performance of the multinational firm depending on the level of development of the host economy. In our results, we find a clear positive relation between multinationality and firm performance. However, investment in developing countries is associated with larger effects on performance than in the case of investment in developed countries. We also find that the return to investing in developing countries is U-shaped. This indicates that multinationals are likely to face losses in the early stage of their investment in developing countries before the positive returns are realized. Overall, our results suggest that the net gains for multinationals from greater geographical diversification have not yet been fully explored. Geographical diversification into developing countries may be an important source of competitive advantages that deserves more serious consideration from business leaders and academics alike. © 2013 Springer-Verlag Berlin Heidelberg.

Transfer of patients from health care centres to special care services:analysis of travel distances in Nordic countries

Objectives: This paper highlights the importance of analysing patient transportation in Nordic circumpolar areas. The research questions we asked are as follows: How many Finnish patients have been transferred to special care intra-country and inter-country in 2009? Does it make any difference to health care policymakers if patients are transferred inter-country? Study design: We analysed the differences in distances from health care centres to special care services within Finland, Sweden and Norway and considered the health care policy implica tions. Methods: An analysis of the time required to drive between service providers using the "Google distance meter" (http://maps.google.com/); conducting interviews with key Finnish stakeholders; and undertaking a quantitative analyses of referral data from the Lapland Hospital District. Results: Finnish patients are generally not transferred for health care services across national borders even if the distances are shorter. Conclusion: Finnish patients have limited access to health care services in circumpolar are as across the Nordic countries for 2 reasons. First, health professionals in Norway and Sweden do not speak Finnish, which presents a language problem. Second, The Social Insurance Institution of Finland does not cover the expenditures of travel or the costs of medicine. In addition, it seems that in circumpolar areas the density of Finnish service providers is greater than Swedish ones, causing many Swedish citizens to transfer to Finnish health care providers every year. However, future research is needed to determine the precise reasons for this.

Evolution of optical pulses in fiber lines with lumped nonlinear devices as a mapping problem

We analyze the steady-state propagation of optical pulses in fiber transmission systems with lumped nonlinear optical devices (NODs) placed periodically in the line. For the first time to our knowledge, a theoretical model is developed to describe the transmission regime with a quasilinear pulse evolution along the transmission line and the point action of NODs. We formulate the mapping problem for pulse propagation in a unit cell of the line and show that in the particular application to nonlinear optical loop mirrors, the steady-state pulse characteristics predicted by the theory accurately reproduce the results of direct numerical simulations. © 2005 Springer Science+Business Media, Inc.

Evolution of timing jitter in nonlinearly-guided, dispersion managed transmission systems

Timing jitter is a major factor limiting the performance of any high-speed, long-haul data transmission system. It arises from a number of reasons, such as interaction with accumulated spontaneous emission, inter-symbol interference (ISI), electrostriction etc. Some effects causing timing jitter can be reduced by means of non-linear filtering, using, for example, a nonlinear optical loop mirror (NOLM) [1]. The NOLM has been shown to reduce the timing jitter by suppressing the ASE and by stabilising the pulse duration [2, 3]. In this paper, we investigate the dynamics of timing jitter in a 2R regenerated system, nonlinearly guided by NOLMs at bit rates of 10, 20, 40, and 80- Gbit/s. Transmission performance of an equivalent non-regenerated (generic) system is taken as a reference.

Mechanical properties and the evolution of matrix molecules in PTFE upon irradiation with MeV alpha particles

The morphology, chemical composition, and mechanical properties in the surface region of α-irradiated polytetrafluoroethylene (PTFE) have been examined and compared to unirradiated specimens. Samples were irradiated with 5.5 MeV 4He2+ ions from a tandem accelerator to doses between 1 × 106 and 5 × 1010 Rad. Static time-of-flight secondary ion mass spectrometry (ToF-SIMS), using a 20 keV C60+ source, was employed to probe chemical changes as a function of a dose. Chemical images and high resolution spectra were collected and analyzed to reveal the effects of a particle radiation on the chemical structure. Residual gas analysis (RGA) was utilized to monitor the evolution of volatile species during vacuum irradiation of the samples. Scanning electron microscopy (SEM) was used to observe the morphological variation of samples with increasing a particle dose, and nanoindentation was engaged to determine the hardness and elastic modulus as a function of a dose. The data show that PTFE nominally retains its innate chemical structure and morphology at a doses <109 Rad. At α doses ≥109 Rad the polymer matrix experiences increased chemical degradation and morphological roughening which are accompanied by increased hardness and declining elasticity. At  α doses >1010 Rad the polymer matrix suffers severe chemical degradation and material loss. Chemical degradation is observed in ToF-SIMS by detection of ions that are indicative of fragmentation, unsaturation, and functionalization of molecules in the PTFE matrix. The mass spectra also expose the subtle trends of crosslinking within the α-irradiated polymer matrix. ToF-SIMS images support the assertion that chemical degradation is the result of a particle irradiation and show morphological roughening of the sample with increased a dose. High resolution SEM images more clearly illustrate the morphological roughening and the mass loss that accompanies high doses of a particles. RGA confirms the supposition that the outcome of chemical degradation in the PTFE matrix with continuing irradiation is evolution of volatile species resulting in morphological roughening and mass loss. Finally, we reveal and discuss relationships between chemical structure and mechanical properties such as hardness and elastic modulus.

The evolution of immigration discourse in the Maltese press from 2005 to 2015: A case study of the Times of Malta

El drama migratorio del cual está siendo Europa testigo en estas últimas semanas es en parte el resultado de una falta de políticas comunitarias en relación a este tema, hecho del cual, en los últimos años, se han hecho eco multitud de medios. Europa, y en especial los países del Mediterráneo, ha experimentado un incremento sustancial en el número de inmigrantes que llegan a sus costas en condiciones cada vez más deplorables y arriesgando gravemente su integridad física. Este hecho está principalmente motivado por el aumento y la intensidad de los conflictos bélicos en países de África y Oriente próximo. En el caso de Malta, un diminuto archipiélago ubicado entre los territorios de Libia y Sicilia, el cambio en la tendencia migratoria que se produjo en 2002 le hizo pasar de ser un país de emigrantes a un país receptor de inmigrantes. Este cambio dio como resultado la aparición de grupos y partidos anti-inmigración, como Azzjoni Nazzjonali, y de un sentimiento de preocupación frente a la llegada de inmigrantes que crece de manera constante según se refleja en encuestas europeas (véase Eurobarometer 82-83). Desde el punto de vista lingüístico, el discurso discriminatorio empleado por los medios de comunicación, organismos y figuras políticas ha sido ampliamente estudiado dentro de la rama del Análisis Crítico del Discurso (Charteris-Black, 2006; Fairclough, 1989, Reisigl & Wodak, 2001; Santa Ana, 1999; Van Dijk, 1984, 1992, 1999, 2000, 2006, Van Leeuwen & Wodak, 1999). En los últimos años, se ha potenciado el uso de un enfoque cognitivo en el análisis de este tipo de discursos. Dicho enfoque utiliza elementos tomados de la lingüística cognitiva para explicar cómo la representación de eventos y participantes en el discurso atiende, o está motivada por la conceptualización mental de dichos eventos y participantes (Charteris-Black, 2006; Hart, 2011; Musolff, 2012; Núñez-Perucha, 2011; O’Brien, 2003; Santa Ana, 1999; Van Dijk, 1992, 1998, 1999, 2000, 2006; Wodak, 2006). El Análisis Crítico del Discurso es una disciplina cuyo principal objetivo es analizar cómo ciertos fenómenos sociales que se basan en relaciones de abuso de poder y dominación se representan en el discurso de las denominadas élites (Van Dijk, 2001). Muchos de estos discursos atienden a lo que en lingüística se ha denominado discurso de discriminación, en donde un grupo dominante ejerce poder sobre otro mediante el uso de diversas herramientas discursivas. Generalmente, estos estudios sobre discursos de discriminación se han centrado en fenómenos como el machismo o el racismo. Dentro de este último campo, cabe destacar el trabajo de Van Dijk en el análisis del discurso del racismo y del discurso de la inmigración (Van Dijk, 1992, 1999, 2000, 2001, 2006). El presente trabajo se centra en analizar cómo la prensa maltesa ha representado el fenómeno de la inmigración y a los inmigrantes desde 2005 hasta 2015. Dentro de esta línea temporal, se presta especial atención al día 2 de abril de 2013. Esta es la fecha en la que la Associated Press, una organización de prensa independiente con subscriptores alrededor del mundo, decidió incluir un importante cambio léxico en su manual de estilo. El motivo del mismo era modificar el uso del adjetivo “ilegal” recomendando su uso para referirse exclusivamente a acciones (ej. Inmigración ilegal) pero nunca para referirse a individuos (ej. Inmigrante ilegal). Nuestro estudio pretende identificar hasta qué punto esta medida se ha puesto en práctica en los periódicos malteses y qué repercusiones ha tenido su incorporación en la representación de los inmigrantes y la inmigración. Para ello, se ha seleccionado como caso de estudio uno de los periódicos en lengua inglesa más leídos en el archipiélago, Times of Malta. El estudio se ha centrado en el análisis de un total de treinta artículos de opinión repartidos de manera homogénea (quince y quince) en dos corpus. El primer corpus contiene artículos pertenecientes a un periodo de tiempo que va desde 2005 hasta la fecha en la cual el cambio léxico de la Associated Press fue publicado, es decir, el 2 de abril de 2013. Por otro lado, el segundo corpus contiene artículos desde el 2 de abril de 2013 hasta mediados de 2015. Para agilizar y facilitar el análisis de los artículos, se ha hecho uso del programa llamado WordSmith Tools, el cual está especializado en el trabajo con corpus. Este programa se utilizó principalmente para analizar la representación semántica de los distintos participantes y eventos. Los resultados del análisis demuestran que el periódico ha aplicado el cambio léxico sugerido por la Associated Press al no encontrarse ningún ejemplo de “inmigrante ilegal” o “migrante ilegal” a partir del 2 de abril de 2013. En estos mismos resultados también se aprecia una representación más positiva de la figura del inmigrante en el segundo corpus, dónde el inmigrante abandona la categoría léxica de “criminal” para comenzar a ser visto cada vez más como la víctima. También a nivel léxico, se puede observar cómo los autores tienden a usar cada vez más el término “migrante” en lugar de “inmigrante”. A pesar de que este último continúa siendo el término más utilizado para referirse a la persona que llega desde otro país, el significativo incremento del uso de la palabra “migrante” en el segundo corpus es llamativo y puede deberse a que la palabra “inmigrante” haya adquirido connotaciones negativas por su repetido uso junto al adjetivo “ilegal”. De entre las estrategias discursivas empleadas en la representación de la sociedad maltesa, cabe destacar dos. Por un lado, tenemos el uso de la victimización, mediante la cual la población maltesa aparece como una víctima frente a la inmigración, que es vista como una amenaza, al mismo tiempo que Malta es también víctima de la falta de apoyo internacional. En segundo lugar, es también común encontrar artículos en donde el autor destaca las cualidades positivas de la sociedad maltesa, especialmente su generosidad. Esta última estrategia es lo que Van Dijk denomina national self-glorifiation (2000:220; 2006:738). En cuanto al uso de las metáforas, el cambio es menos significativo. En general, ambos corpus muestran ejemplos de metáforas en las que el inmigrante aparece conceptualizado como parte de un fenómeno natural incontrolable, un invasor o un organismo dispuesto a infectar o dañar de algún modo el país. En el segundo corpus, sin embargo, desaparecen las metáforas en las que el inmigrante se percibe como un animal inferior, que sí aparecían en el primer corpus. Esto supone un cambio positivo. Hasta este punto hemos resumido los cambios en la representación de los inmigrantes. Respecto al modo en el cual el fenómeno de la inmigración aparece representado en los periódicos, también encontramos cambios importantes. A nivel léxico, el cambio que mencionábamos relativo a los términos “inmigrante” y “migrante” también se produce a la hora de nombrar este fenómeno social. De este modo, la palabra “migración” es más usada en el segundo corpus que en el primero, aunque sigue ocupando el segundo lugar por detrás de la palabra “inmigración”. En cuanto a los contenidos, se puede observar un cambio positivo hacia una mayor concienciación social. Por ejemplo, vemos cómo en el segundo corpus en ocasiones se pide una respuesta estatal a temas como la integración de los inmigrantes o el racismo entre la sociedad, mientras que en el primer corpus la integración era una labor del inmigrante y el racismo era un tema incómodo. En el segundo corpus también encontramos la queja más clara hacia el uso de centros de detención en la isla. En el primer corpus, aunque algunos autores manifestaban su disconformidad con las condiciones en las cuales los inmigrantes vivían dentro de los centros de detención, todos asumían que tener dichos centros era una medida necesaria. Esta especie de consenso social y político acerca del uso de centros de detención se consigue mediante el empleo de herramientas discursivas que representen la inmigración como una amenaza de la cual hay que protegerse (negative other-presentation Van Dijk, 2000:221; 2006:738). En resumen, podemos decir que este trabajo muestra una progresión en el discurso de inmigración en Malta hacia una representación más positiva y amable del inmigrante y de la inmigración. Aunque las limitaciones de este estudio hacen imposible establecer una relación única y directa entre los cambios experimentados por el periódico y el cambio léxico sugerido por la Associated Press, lo cierto es que la descriminalización de los inmigrantes a nivel léxico (mediante la supresión de términos como “ilegal” o “detenidos”) ha influido de manera positiva en el tono y la forma en que este periódico se refiere al fenómeno social de la inmigración

The Roles of Phenotypic Plasticity and Plant-Microbe Interactions in the Evolution of Complex Traits in Boechera stricta

All organisms live in complex habitats that shape the course of their evolution by altering the phenotype expressed by a given genotype (a phenomenon known as phenotypic plasticity) and simultaneously by determining the evolutionary fitness of that phenotype. In some cases, phenotypic evolution may alter the environment experienced by future generations. This dissertation describes how genetic and environmental variation act synergistically to affect the evolution of glucosinolate defensive chemistry and flowering time in Boechera stricta, a wild perennial herb. I focus particularly on plant-associated microbes as a part of the plant’s environment that may alter trait evolution and in turn be affected by the evolution of those traits. In the first chapter I measure glucosinolate production and reproductive fitness of over 1,500 plants grown in common gardens in four diverse natural habitats, to describe how patterns of plasticity and natural selection intersect and may influence glucosinolate evolution. I detected extensive genetic variation for glucosinolate plasticity and determined that plasticity may aid colonization of new habitats by moving phenotypes in the same direction as natural selection. In the second chapter I conduct a greenhouse experiment to test whether naturally-occurring soil microbial communities contributed to the differences in phenotype and selection that I observed in the field experiment. I found that soil microbes cause plasticity of flowering time but not glucosinolate production, and that they may contribute to natural selection on both traits; thus, non-pathogenic plant-associated microbes are an environmental feature that could shape plant evolution. In the third chapter, I combine a multi-year, multi-habitat field experiment with high-throughput amplicon sequencing to determine whether B. stricta-associated microbial communities are shaped by plant genetic variation. I found that plant genotype predicts the diversity and composition of leaf-dwelling bacterial communities, but not root-associated bacterial communities. Furthermore, patterns of host genetic control over associated bacteria were largely site-dependent, indicating an important role for genotype-by-environment interactions in microbiome assembly. Together, my results suggest that soil microbes influence the evolution of plant functional traits and, because they are sensitive to plant genetic variation, this trait evolution may alter the microbial neighborhood of future B. stricta generations. Complex patterns of plasticity, selection, and symbiosis in natural habitats may impact the evolution of glucosinolate profiles in Boechera stricta.

The Evolution of Chimpanzee Sanctuaries in the United States

Chimpanzees are native only to the jungles of equatorial Africa, but for the last hundred years, they have also lived in captivity in the United States, most commonly in biomedical research laboratories, but also at Air Force bases for experiments for the space program, at accredited and unaccredited zoos, at circuses, as performers in Hollywood and even in private homes and backyards as pets. But that has been gradually evolving over the last few decades, as more and more chimpanzees move to newly-established chimpanzee sanctuaries. That transition was already underway even before the announcement by the National Institutes of Health (NIH) last year that it will retire all of its remaining chimpanzees from labs to sanctuaries. By thoroughly examining the evolution of these sanctuaries leading up to that seminal decision, along with the many challenges they face, including money, medical care, conflicting philosophies on the treatment of animals and the pitfalls that have led other sanctuaries to the brink of ruin, we can take away a better understanding of why chimpanzee sanctuaries are needed and why caretakers of other animal species are now looking to the chimpanzee sanctuary movement as a model to show how animals can be cared for in retirement.

The evolution of public–private partnership in Ireland: a sustainable pathway?

Ireland is a latecomer to Public Private Partnership (PPP) having only adopted it in 1998. Prior to the credit crisis, Ireland followed the UK model with PPPs being implemented in transport, education, housing/urban regeneration and water/wastewater. Having stalled during the credit crisis, PPP has been reactivated recently with the domestic infrastructure stimulus programme . The focus of this paper is on Ireland as a younger participant in PPP and the nexus between adoption patterns and sustainability characteristics of Irish PPP. Using document analysis and exploratory interviews, the paper examines the reasons for Ireland’s interest in PPP which cannot be attributed to economic rationales alone. We consider three explanations: voluntary adoption – where the UK model was closely followed as part of a domestic modernisation agenda; coercive adoption – where PPP policy was forced upon public sector organisations; and institutional isomorphism – where institutional creation and change around PPP was promoted to help public sector organisations gain institutional legitimacy. We find evidence of all three patterns with coercive adoption becoming more relevant in recent years, which is likely to affect sustainability adversely unless incentives for voluntary adoption are strengthened and institutional capacity building is boosted.

Cognitive Component Skills of Reading Comprehension in Developing Readers

Die Fähigkeit, geschriebene Texte zu verstehen, d.h. eine kohärente mentale Repräsentation von Textinhalten zu erstellen, ist eine notwendige Voraussetzung für eine erfolgreiche schulische und außerschulische Entwicklung. Es ist daher ein zentrales Anliegen des Bildungssystems Leseschwierigkeiten frühzeitig zu diagnostizieren und mithilfe zielgerichteter Interventionsprogramme zu fördern. Dies erfordert ein umfassendes Wissen über die kognitiven Teilprozesse, die dem Leseverstehen zugrunde liegen, ihre Zusammenhänge und ihre Entwicklung. Die vorliegende Dissertation soll zu einem umfassenden Verständnis über das Leseverstehen beitragen, indem sie eine Auswahl offener Fragestellungen experimentell untersucht. Studie 1 untersucht inwieweit phonologische Rekodier- und orthographische Dekodierfertigkeiten zum Satz- und Textverstehen beitragen und wie sich beide Fertigkeiten bei deutschen Grundschüler(inne)n von der 2. bis zur 4. Klasse entwickeln. Die Ergebnisse legen nahe, dass beide Fertigkeiten signifikante und eigenständige Beiträge zum Leseverstehen leisten und dass sich ihr relativer Beitrag über die Klassenstufen hinweg nicht verändert. Darüber hinaus zeigt sich, dass bereits deutsche Zweitklässler(innen) den Großteil geschriebener Wörter in altersgerechten Texten über orthographische Vergleichsprozesse erkennen. Nichtsdestotrotz nutzen deutsche Grundschulkinder offenbar kontinuierlich phonologische Informationen, um die visuelle Worterkennung zu optimieren. Studie 2 erweitert die bisherige empirische Forschung zu einem der bekanntesten Modelle des Leseverstehens—der Simple View of Reading (SVR, Gough & Tunmer, 1986). Die Studie überprüft die SVR (Reading comprehension = Decoding x Comprehension) mithilfe optimierter und methodisch stringenter Maße der Modellkonstituenten und überprüft ihre Generalisierbarkeit für deutsche Dritt- und Viertklässler(innen). Studie 2 zeigt, dass die SVR einer methodisch stringenten Überprüfung nicht standhält und nicht ohne Weiteres auf deutsche Dritt- und Viertklässler(innen) generalisiert werden kann. Es wurden nur schwache Belege für eine multiplikative Verknüpfung von Dekodier- (D) und Hörverstehensfertigkeiten (C) gefunden. Der Umstand, dass ein beachtlicher Teil der Varianz im Leseverstehen (R) nicht durch D und C aufgeklärt werden konnte, deutet darauf hin, dass das Modell nicht vollständig ist und ggf. durch weitere Komponenten ergänzt werden muss. Studie 3 untersucht die Verarbeitung positiv-kausaler und negativ-kausaler Kohärenzrelationen bei deutschen Erst- bis Viertklässler(inne)n und Erwachsenen im Lese- und Hörverstehen. In Übereinstimmung mit dem Cumulative Cognitive Complexity-Ansatz (Evers-Vermeul & Sanders, 2009; Spooren & Sanders, 2008) zeigt Studie 3, dass die Verarbeitung negativ-kausaler Kohärenzrelationen und Konnektoren kognitiv aufwändiger ist als die Verarbeitung positiv-kausaler Relationen. Darüber hinaus entwickelt sich das Verstehen beider Kohärenzrelationen noch über die Grundschulzeit hinweg und ist für negativ-kausale Relationen am Ende der vierten Klasse noch nicht abgeschlossen. Studie 4 zeigt und diskutiert die Nützlichkeit prozess-orientierter Lesetests wie ProDi- L (Richter et al., in press), die individuelle Unterschiede in den kognitiven Teilfertigkeiten des Leseverstehens selektiv erfassen. Hierzu wird exemplarisch die Konstruktvalidität des ProDi-L-Subtests ‚Syntaktische Integration’ nachgewiesen. Mittels explanatorischer Item- Repsonse-Modelle wird gezeigt, dass der Test Fertigkeiten syntaktischer Integration separat erfasst und Kinder mit defizitären syntaktischen Fertigkeiten identifizieren kann. Die berichteten Befunde tragen zu einem umfassenden Verständnis der kognitiven Teilfertigkeiten des Leseverstehens bei, das für eine optimale Gestaltung des Leseunterrichts, für das Erstellen von Lernmaterialien, Leseinstruktionen und Lehrbüchern unerlässlich ist. Darüber hinaus stellt es die Grundlage für eine sinnvolle Diagnose individueller Leseschwierigkeiten und für die Konzeption adaptiver und zielgerichteter Interventionsprogramme zur Förderung des Leseverstehens bei schwachen Leser(inne)n dar.

The Political Economy of Information Provision in Developing Democracies

Thesis (Ph.D.)--University of Washington, 2016-07

THE ROLE OF DYNAMIC CAPABILITIES IN THE INTERNATIONALIZATION OF MEDIUM SIZED FINNISH MANUFACTURING FIRMS - A case for Sormat Oy

A rapidly changing business environment has necessitated most small and medium sized enterprises with international ambitions to reconsider their sources of competitive advantage. To survive in the face of a changing business environment, firms should utilize their dynamic organizational capabilities as well as their internationalization capabilities. Firms develop a competitive advantage if they can exploit their unique organizational competences in a new or foreign market and also if they can acquire new capabilities as a result of engaging in foreign markets. The acquired capabilities from foreign locations enhance the existing capability portfolio of a firm with a desire to internationalize. The study combined the research streams of SME organizational dynamic capability and internationalization capability to build a complete picture on the existing knowledge. An intensive case study was used for empirically testing the theoretical framework of the study and compared with the literature on various organizational capability factors and internationalization capabilities. Sormay Oy was selected because it is a successful medium sized company operating in Finland in the manufacturing industry which has a high international profile. In addition, it has sufficient rate of growth in sales that warrants it to engage internationally in matters such as, acquisitions, joint ventures and partnerships. The key findings of the study suggests that, medium sized manufacturing firms have a set of core competences arising from their organizational capabilities which were identified to be employee know how and relationship with stakeholders which aid the firm in its quest for attaining competitive advantage, ensuring production flexibility and gaining benefits present in a network. In addition, internationalization capabilities were identified under both the RAT test and CAT test whereby the primary findings suggests that, firms that outperform their competitors produce products that meet specific customer and country requirements, foresee the pitfalls of imitation brought about by the foreign local companies and members of a particular network through joint ventures, acquisitions or partnerships as well as those firms that are capable to acquire new capabilities in the foreign markets and successfully use these acquired capabilities to enhance or renew their capability portfolio for their competitive advantage. Additional significant findings under internationalization capabilities were discovered whereby, Sormay Oy was able to develop a new market space for its products despite the difficult institutional environment present in Russia.

The evolution of imperfect mimicry in hoverflies

Ideas about the evolution of imperfect mimicry are reviewed. Their relevance to the colours patterns of hoverflies (Diptera, Syrphidae) are discussed in detail. Most if not all of the hoverflies labelled as mimetic actually are mimics. The apparently poor nature of their resemblance does not prevent them from obtaining at least some protection from suitably experienced birds. Mimicry is a dominant theme of this very large family of Diptera, with at least a quarter of all species in Europe being mimetic. Hoverfly mimics fall into three major groups according to their models, involving bumblebees, honeybees and social wasps. There are striking differences in the general levels of mimetic fidelity and relative abundances of the three groups, with accurate mimicry, low abundance and polymorphism characterizing the bumblebee mimics: more than half of all the species of bumblebee mimics are polymorphic. Mimics of social wasps tend to be poor mimics, have high relative abundance, and polymorphism is completely absent. Bumblebee models fall into a small number of Muellerian mimicry rings which are very different between the Palaearctic and Nearctic regions. Social wasps and associated models form one large Muellerian complex. Together with honeybees, these complexes probably form real clusters of forms as perceived by many birds. All three groups of syrphid mimics contain both good and poor mimics; some mimics are remarkably accurate, and have close morphological and behavioural resemblance. At least some apparently 'poor' mimetic resemblances may be much closer in birds' perception than we imagine, and more work needs to be done on this. Bumblebees are the least noxious and wasps the most noxious of the three main model groups. The basis of noxiousness is different, with bumblebees being classified as non-food, whereas honeybees and wasps are nasty-tasting and (rarely) stinging. The distribution of mimicry is exactly what would be expected from this ordering, with polymorphic and accurate forms being a key feature of mimics of the least noxious models, while highly noxious models have poor-quality mimicry. Even if the high abundance of many syrphid mimics relative to their models is a recent artefact of man-made environmental change, this does not preclude these species from being mimics. It seems unlikely that bird predation actually controls the populations of adult syrphids. Being rare relative to a model may have promoted or accelerated the evolution of perfect mimicry: theoretically this might account for the pattern of rare good mimics and abundant poor ones, but the idea is intrinsically unlikely. Many mimics seem to have hour-to-hour abundances related to those of their models, presumably as a result of behavioural convergence. We need to know much more about the psychology of birds as predators. There are at least four processes that need elucidating: (a) learning about the noxiousness of models; (b) the erasing of that learning through contact with mimics (extinction, or learned forgetting); (c) forgetting; (d) deliberate risk-taking and the physiological states that promote it. Johnston's (2002) model of the stabilization of imperfect mimicry by kin selection is unlikely to account for the colour patterns of hoverflies. Sherratt's (2002) model of the influence of multiple models potentially accounts for all the patterns of hoverfly mimicry, and is the most promising avenue for testing.

Survey of veterinery drug residues, environmental contaminants and mycotoxins of cultured shirmp in Iran

Economical achievement of optimal growth in developing countries may lead to sustainable poverty reduction. Agricultural activities play an important role in economy and human being welfare, which leads to establishment of food security and quality. Aquaculture products in developing countries share 51.4 percent of total agricultural production and 241 percent in developed countries. Therefore undoubtedly food production by means of quality and quantity has to be increased .The history of shrimp production goes back to 500 years ago. Today 50 countries of the world produce shrimp. In Islamic Republic of Iran shrimp production started since 1992 in the coastal region of Persian Gulf. The shrimp culture farms can be classified in to 4 different categories; extensive, semi-extensive, intensive and super intensive. Global ecological maintenance is one of the major concerns of authorities Human manipulation of nature is the most destructive activity. Industrial sewage leakage in to the rivers and water sources is a big issue that causes reduction in the aquatic population. Heavy metals have an inhibitory effect in the production and growth of sea life. Human intake of food treated with anti-microbial cause's allergy, hypersensitivity and develops microbial resistance. Organochlorine compounds contamination may found in hepatopancreatic tissue of aquatic products, Arsenic may transfer to man via plant and animal product contamination.