976 resultados para Neptune (Planet)


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The existence of a new class of inclined periodic orbits of the collision restricted three-body problem is shown. The symmetric periodic solutions found are perturbations of elliptic kepler orbits and they exist only for special values of the inclination and are related to the motion of a satellite around an oblate planet

Relevância:

10.00% 10.00%

Publicador:

Resumo:

It is axiomatic that our planet is extensively inhabited by diverse micro-organisms such as bacteria, yet the absolute diversity of different bacterial species is widely held to be unknown. Different bacteria can be found from the depths of the oceans to the top of the mountains; even the air is more or less colonized by bacteria. Most bacteria are either harmless or even advantageous to human beings but there are also bacteria, which can cause severe infectious diseases or spoil the supplies intended for human consumption. Therefore, it is vitally important not only to be able to detect and enumerate bacteria but also to assess their viability and possible harmfulness. Whilst the growth of bacteria is remarkably fast under optimum conditions and easy to detect by cultural methods, most bacteria are believed to lie in stationary phase of growth in which the actual growth is ceased and thus bacteria may simply be undetectable by cultural techniques. Additionally, several injurious factors such as low and high temperature or deficiency of nutrients can turn bacteria into a viable but non-culturable state (VBNC) that cannot be detected by cultural methods. Thereby, various noncultural techniques developed for the assessment of bacterial viability and killing have widely been exploited in modern microbiology. However, only a few methods are suitable for kinetic measurements, which enable the real-time detection of bacterial growth and viability. The present study describes alternative methods for measuring bacterial viability and killing as well as detecting the effects of various antimicrobial agents on bacteria on a real-time basis. The suitability of bacterial (lux) and beetle (luc) luciferases as well as green fluorescent protein (GFP) to act as a marker of bacterial viability and cell growth was tested. In particular, a multiparameter microplate assay based on GFP-luciferase combination as well as a flow cytometric measurement based on GFP-PI combination were developed to perform divergent viability analyses. The results obtained suggest that the antimicrobial activities of various drugs against bacteria could be successfully measured using both of these methods. Specifically, the data reliability of flow cytometric viability analysis was notably improved as GFP was utilized in the assay. A fluoro-luminometric microplate assay enabled kinetic measurements, which significantly improved and accelerated the assessment of bacterial viability compared to more conventional viability assays such as plate counting. Moreover, the multiparameter assay made simultaneous detection of GFP fluorescence and luciferase bioluminescence possible and provided extensive information about multiple cellular parameters in single assay, thereby increasing the accuracy of the assessment of the kinetics of antimicrobial activities on target bacteria.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Master’s Thesis concentrates to means and challenges in international operations for a Finnish mobile application provider Small Planet Oy during its various company stages from founding till maturing and during macro economical phases between year 1998 and 2008. Small Planet has just celebrated its 10 year anniversary and is therefore quite an extraordinary company which has survived all the highs and lows during past ten years and which has operated in the market as long as the whole mobile application industry has existed. Master’s Thesis describes possibilities for a company’s internationalization with different entry modes like exporting, licensing, investment entry and co-operative operations which are suitable for a mobile application provider. Unsuitable entry modes like franchising or contract manufacturing are not explained. The goal has been to analyze Small Planet’s international operations and to make conclusions from the practical experiences. Analysis and conclusions shall help Small Planet in its international operations in the future and should give insight to other mobile application companies and their managers who are in the situation of planning their own international operations. Results show that the best ways for Small Planet to internationalize its operations has been the co-operation with a big domestic client and the co-operation with Finnish operator infrastructure providers which have complementary products with Small Planet. Through these co-operations Small Planet has got lot of new international clients. Same time financial risks and investment need for international operations have been low. Co-operative international sales can be the most efficient international entry mode for a mobile application provider.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Insects are the most diverse group of animals on the planet, comprising over 90% of all metazoan life forms, and have adapted to a wide diversity of ecosystems in nearly all environments. They have evolved highly sensitive chemical senses that are central to their interaction with their environment and to communication between individuals. Understanding the molecular bases of insect olfaction is therefore of great importance from both a basic and applied perspective. Odorant binding proteins (OBPs) are some of most abundant proteins found in insect olfactory organs, where they are the first component of the olfactory transduction cascade, carrying odorant molecules to the olfactory receptors. We carried out a search for OBPs in the genome of the parasitoid wasp Nasonia vitripennis and identified 90 sequences encoding putative OBPs. This is the largest OBP family so far reported in insects. We report unique features of the N. vitripennis OBPs, including the presence and evolutionary origin of a new subfamily of double-domain OBPs (consisting of two concatenated OBP domains), the loss of conserved cysteine residues and the expression of pseudogenes. This study also demonstrates the extremely dynamic evolution of the insect OBP family: (i) the number of different OBPs can vary greatly between species; (ii) the sequences are highly diverse, sometimes as a result of positive selection pressure with even the canonical cysteines being lost; (iii) new lineage specific domain arrangements can arise, such as the double domain OBP subfamily of wasps and mosquitoes.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Peer-reviewed

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Tutkimuksen kohteena ovat äitiydelle tuotetut kulttuuriset odotukset, joita tarkastellaan kahdella yhteiskunnallisella keskustelufoorumilla. Tutkimuksessa tarkastellaan yhtäältä lastensuojelun perhetyössä toimivien ammattilaisten ja toisaalta median puhetta äitiydestä. Tutkimuksen tavoitteena on tehdä näkyväksi vaihtoehtoisia tapoja konstruoida äitiyttä hyvänä tai riittämättömänä sekä haastaa pohtimaan erilaisten tulkintojen perusteita ja seurauksia lastensuojelutyössä. Kulttuuriset, äitiyttä koskevat odotukset vaikuttavat myös siihen, miten äitiys henkilökohtaisella tasolla koetaan. Äitiyden kulttuurista määrittelyä analysoidaan kahdesta tekstiaineistosta. Yhtenä aineistona ovat Stakesissa vuonna 1999 toteutetun Perhetyöprojektin yhteydessä kerätyt, lastensuojelussa toimivien perhetyöammattilaisten ryhmäkeskustelut. Toisena aineistona on projektin ajankohtana ilmestyneistä suomalaisista naisten- ja perhelehdistä (Kotiliesi, Anna, Kaksplus) kerätyt äitien haastattelut. Tutkimuksessa kysytään 1) Mihin ammattilaisten äitejä koskeva huolipuhe kiinnittyy ja millaisia kulttuurisia äitiyden odotuksia se konstruoi? 2) Millaisia äitiyden odotuksia median äitihaastattelut konstruoivat? 3) Millaisen äitiyden odotushorisontin nämä puhekäytännöt yhdessä tuottavat? Analyysin teoreettis-metodologisina kulmakivinä ovat sosiaalinen konstruktionismi ja feministinen tietokäsitys. Analyysimenetelmänä on laadullinen, aineistojen ehdoilla etenevä, feministisesti ja kriittisesti sävyttynyt lukutapa, joka hyödyntää teemoittelun, diskurssianalyysin ja feministisen metodologian ideoita ja käsitteitä. Analysoitavana olevissa keskusteluissa äitiyttä konstruoidaan lapsen tarpeiden (ammattilaiset) ja naisen tarpeiden (media) näkökulmista. Ammattilaiset puhuvat tilanteista, joissa äitien toiminta rikkoo kulttuurista hyvän äidin kuvaa, vaarantaa lapsen hyvinvointia ja äitiyteen joudutaan puuttumaan ammatillisesti. Ammattilaisten tulkinnat kuvaavat taitavaa lapsen edun näkökulmasta tehtyä arviointia, jonka kiintopisteenä ovat äidit yksilöllisine ominaisuuksineen ja piirteineen. Ammatillisen huolipuheen keskiössä ovat äidin vuorovaikutussuhteet sekä äidin tunteet, käyttäytyminen ja asenteet. Riittävää äitiyttä konstruoi kodin luominen, kiintymyssuhteen rakentaminen ja lapsen ensisijaiseksi asettaminen. Sen sijaan vaikuttaa siltä, ettei äitiyden arviointia juurikaan tehdä suhteessa äidin muihin identiteetteihin tai äitiyden toteuttamisen kontekstiin. Paikoin ammattilaisten tulkinnat heijastavat myös stereotyyppisiä ja idealistisia odotuksia, joita vasten äitiyttä arvioidaan. Tällaiset piirteet voivat kertoa siitä, että äitien avuntarpeet jäävät lastensuojelutyössä kohtaamatta ja ymmärtämättä. Mediapuhe äitiydestä käydään naiseuden ja äitiyden mallien antamisen kontekstissa. Puheen keskiössä ovat mediajulkisuuteen päässeiden naisten äidiksi tuloon ja äitiyden toteuttamiseen liittyvät valinnat ja käyttäytyminen. Mediapuhe on puhetta kulttuuristen ja ammatillisten äitiyden odotusten rikkomisesta, uudelleen tulkinnasta ja niiden muovaamisesta itselle sopiviksi. Mediapuheessa hyvää äitiyttä konstruoi äidin itsenäisyys ja oma aika, sosiaalisen elämän rikkaus, ammatillinen identiteetti ja persoonalliset valinnat. Aineistojen kautta rakentuu moninaisten ja ristiriitaisten, äitejä eri suuntaan vetävien kulttuuristen odotusten kirjo. Odotukset jäsentyvät neljälle ulottuvuudelle: 1) lapselle omistautuva – itseään toteuttava, 2) emotionaalinen side – rationaalinen tehtävä, 3) odotuksia toteuttava – omaehtoinen, 4) itsenäinen - äitiyttä jakava. Äitiyden toteuttaminen kulttuurisesti ”oikein” on näiden odotusten välissä tasapainoilua. Ulottuvuuksien kautta esille tulevat kaksoisviestit voivat heikentää äitien itsetuntoa, tuottaa riittämättömyyden tunteita tai yllyttää suorittamaan äitiyttä. Myös äitiyden ammatillinen tukeminen edellyttää tasapainoilua, jottei äitejä idealisoida tai syyllistetä kulttuurisia odotuksia vasten.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Existe un número elevado de sectores de la sociedad que identifican los beneficios ofrecidos por el ecosistema del manglar así como la interacción entre ellos y el bienestar humano. Aún así, los servicios ecosistémicos (ESs) ofrecidos por la naturaleza son poco visibles y reconocidos legislativamente. Se puede observar que el manglar es uno de los ecosistemas más productivos del planeta. Tienen gran importancia tanto económica, social, ambiental como cultural, pero en las últimas décadas se ha hecho más notable una degradación progresiva debida, en gran parte, a la cría de camarón en cautividad, la camaronicultura. Por esta causa, se observa que la legislación y las políticas que pretenden gestionar estos ecosistemas, no actúan en consecuencia al no imponer ciertas medidas necesarias para esta vital protección, ni considera la importancia de los ecosistemas para la vida de las comunidades tradicionales que dependen de sus servicios para sobrevivir. Por ello es necesario producir un conocimiento sobre ESs a partir de la percepción por parte de la comunidad y que la comunidad se implique en la resolución de esta problemática, ya sea en la toma de decisiones o mediante ciertas actividades o acciones que puedan denunciar estas prácticas insostenibles. Frente a este contexto, este trabajo fue realizado a partir de la información obtenida en la comunidad de Curral Velho (Ceará, Brasil), con el objetivo de realizar un estudio sobre los ESs proveídos por los manglares a partir de la percepción de la comunidad para demostrar la importancia que éstos tienen para el bienestar de los habitantes de la comunidad que se benefician. Los resultados fueron alcanzados a partir de una combinación de metodologías sociales que hacen posible la participación por parte de los habitantes: free listing, encuestas de valoración, grupos focales y observación participante. En la aplicación de estos métodos fueron identificados nuevos ESs de carácter psicológico por los pescadores/as de la pesca artesanal. Por lo que se concluye que es importante tener en cuenta la opinión de las comunidades adyacentes para preservar los flujos ecosistémicos que proporciona el manglar.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The cycle of fossil fuels as an energy source for mankind is approaching its end. Finite resources, coupled with greenhouse gas, have led to an increased effort in the search for alternative renewable energy sources. Brazil has a leading position, due to a 46% participation of renewable sources in its primary energy supply, compared to the global average of 12%. The expansion of the renewable sources in Brazil depends on medium and long term planning, and a large volume of investments. The present financial crisis will have major effects in the energy market. Despite a negative initial impact, it is expected that the rearrangement of the financial system will ultimately lead to an expansion in the use of renewable energy sources. Brazil is a tropical country, with the largest biodiversity in our planet and excellent conditions to expand the use of all forms of renewable sources.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Planet transformations caused by human intervention in the last 200 years are largely due to chemical impact. Therefore, this study aimed to identify and analyze the environmental perception of undergraduate students and lecturers in the Chemistry course of the Federal University of Lavras, accounting for the topics "Environmental Definition" and "Relationship between Chemistry and Environment". Two thematic axes for discussion were proposed using theories of Social Representation and Environmental Complexity, with the aim of stimulating the conservationist reasoning and actions. Such axes were proposed to give support to the education of chemists at the undergraduate level.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Heavy metals and pesticides are usually associated with the main problems humankind has created in the natural environment. However, compounds with characteristics of essential macronutrients are causing serious environmental changes that could intensify, compromising the diversity of life on the planet. This is the case of nitrogen compounds, produced by industrial processes for use in intensive agriculture in addition to those unwittingly produced from human activities, available in excess in the environment. These compounds warrant greater attention from researchers in various fields of knowledge and public agencies for environmental control, toward minimizing their availability in the environment, thereby returning conditions closer to the natural environmental balance of the planet.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The marine environment is certainly one of the most complex systems to study, not only because of the challenges posed by the nature of the waters, but especially due to the interactions of physical, chemical and biological processes that control the cycles of the elements. Together with analytical chemists, oceanographers have been making a great effort in the advancement of knowledge of the distribution patterns of trace elements and processes that determine their biogeochemical cycles and influences on the climate of the planet. The international academic community is now in prime position to perform the first study on a global scale for observation of trace elements and their isotopes in the marine environment (GEOTRACES) and to evaluate the effects of major global changes associated with the influences of megacities distributed around the globe. This action can only be performed due to the development of highly sensitive detection methods and the use of clean sampling and handling techniques, together with a joint international program working toward the clear objective of expanding the frontiers of the biogeochemistry of the oceans and related topics, including climate change issues and ocean acidification associated with alterations in the carbon cycle. It is expected that the oceanographic data produced this coming decade will allow a better understanding of biogeochemical cycles, and especially the assessment of changes in trace elements and contaminants in the oceans due to anthropogenic influences, as well as its effects on ecosystems and climate. Computational models are to be constructed to simulate the conditions and processes of the modern oceans and to allow predictions. The environmental changes arising from human activity since the 18th century (also called the Anthropocene) have made the Earth System even more complex. Anthropogenic activities have altered both terrestrial and marine ecosystems, and the legacy of these impacts in the oceans include: a) pollution of the marine environment by solid waste, including plastics; b) pollution by chemical and medical (including those for veterinary use) substances such as hormones, antibiotics, legal and illegal drugs, leading to possible endocrine disruption of marine organisms; and c) ocean acidification, the collateral effect of anthropogenic emissions of CO2 into the atmosphere, irreversible in the human life time scale. Unfortunately, the anthropogenic alteration of the hydrosphere due to inputs of plastics, metal, hydrocarbons, contaminants of emerging concern and even with formerly "exotic" trace elements, such us rare earth elements is likely to accelerate in the near future. These emerging contaminants would likely soon present difficulties for studies in pristine environments. All this knowledge brings with it a great responsibility: helping to envisage viable adaptation and mitigation solutions to the problems identified. The greatest challenge faced by Brazil is currently to create a framework project to develop education, science and technology applied to oceanography and related areas. This framework would strengthen the present working groups and enhance capacity building, allowing a broader Brazilian participation in joint international actions and scientific programs. Recently, the establishment of the National Institutes of Science and Technology (INCTs) for marine science, and the creation of the National Institute of Oceanographic and Hydrological Research represent an exemplary start. However, the participation of the Brazilian academic community in the latest assaults on the frontier of chemical oceanography is extremely limited, largely due to: i. absence of physical infrastructure for the preparation and processing of field samples at ultra-trace level; ii. limited access to oceanographic cruises, due to the small number of Brazilian vessels and/or absence of "clean" laboratories on board; iii. restricted international cooperation; iv. limited analytical capacity of Brazilian institutions for the analysis of trace elements in seawater; v. high cost of ultrapure reagents associated with processing a large number of samples, and vi. lack of qualified technical staff. Advances in knowledge, analytic capabilities and the increasing availability of analytical resources available today offer favorable conditions for chemical oceanography to grow. The Brazilian academic community is maturing and willing to play a role in strengthening the marine science research programs by connecting them with educational and technological initiatives in order to preserve the oceans and to promote the development of society.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The usage of the non-wood pulps in furnishes for various paper grades is the real alternative for substitution of wood fibres in the papermaking. This is especially important now, when the prices for wood are increasing and forest resources are depleting in many regions of our planet. However, there are several problems associated with utilization of such pulps. In terms of the papermaking process one of the main problems is the poor dewatering of the non-wood pulps. This problem can be partially solved by means of retention aids. In the literature part were described technological features of the non-wood pulps as the raw materials for paper production. Moreover, overviews of the retention chemicals and methods for retention measurement were done; special attention was paid to the mechanisms of retention and drainage. Finally, factors affecting on the drainage and retention of non-wood pulps were considered holistically. Particular emphasis was put on the possibility of enzyme treatment for drainage improvement. It was stated that retention aids can significantly improve dewatering of non-wood pulps. In the experimental part the goal was to investigate influence of various microparticle retention aids on the drainage, retention and formation of furnish containing wheat straw pulp, obtained by novel pulping process (Formico™Fib). The parallel test were performed with reference furnish containing only wood pulps. It was found that Bentonite-CPAM retention aid can significantly improve drainage and retention; however formation seems be suffer from such additives. It was stated that performance of the Silica-Starch retention aid significantly depends on the starch dosing sequence and wet-end conditions; this system have shown better formation than other tested retention aids. Silica-CPAM retention aid have provided comparable results in retention and drainage with Bentonite-CPAM, while Silica-starch did not improve dewatering and yielded in lowest filler retention among other aids. Ultimately, optimal dosages for the tested retention chemicals have been suggested.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Kirjallisuusarvostelu