17 resultados para natural service

em Helda - Digital Repository of University of Helsinki


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Natural products constitute an important source of new drugs. The bioavailability of the drugs depends on their absorption, distribution, metabolism and elimination. To achieve good bioavailability, the drug must be soluble in water, stable in the gastrointestinal tract and palatable. Binding proteins may improve the solubility of drug compounds, masking unwanted properties, such as bad taste, bitterness or toxicity, transporting or protecting these compounds during processing and storage. The focus of this thesis was to study the interactions, including ligand binding and the effect of pH and temperature, of bovine and reindeer β-lactoglobulin (βLG) with such compounds as retinoids, phenolic compounds as well as with compounds from plant extracts, and to investigate the transport properties of the βLG-ligand complex. To examine the binding interactions of different ligands to βLG, new methods were developed. The fluorescence binding method for the evaluation of ligand binding to βLG was miniaturized from a quartz cell to a 96-well plate. A method of ultrafiltration sampling combined with high-performance liquid chromatography was developed to assess the binding of compounds from extracts. The interactions of phenolic compounds or retinoids and βLG were investigated using the 96-well plate method. The majority of flavones, flavonols, flavanones and isoflavones and all of the retinoids included were shown to bind to bovine and reindeer βLG. Phenolic compounds, contrary to retinol, were not released at acidic pH. Those results suggest that βLG may have more binding sites, probably also on the surface of βLG. An extract from Camellia sinensis (L.) O. Kunze (black tea), Urtica dioica L. (nettle) and Piper nigrum (black pepper) were used to evaluate whether βLG could bind compounds from plant extracts. Piperine from P. nigrum was found to bind tightly and rutin from U. dioica weakly to βLG. No components from C. sinensis bound to βLG in our experiment. The uptake and membrane permeation of bovine and reindeer βLG, free and bound with retinol, palmitic acid and cholesterol, were investigated using Caco-2 cell monolayers. Both bovine and reindeer βLG were able to cross the Caco-2 cell membrane. Free and βLG-bound retinol and palmitic acid were transported equally, whereas cholesterol could not cross the Caco-2 cell monolayer free or bound to βLG. Our results showed that βLG can bind different natural product compounds, but cannot enhance transport of retinol, palmitic acid or cholesterol through Caco-2 cells. Despite this, βLG, as a water-soluble binding protein, may improve the solubility of natural compounds, possibly protecting them from early degradation and transporting some of them through the stomach. Furthermore, it may decrease their bad or bitter taste during oral administration of drugs or in food preparations. βLG can also enhance or decrease the health benefits of herbal teas and food preparations by binding compounds from extracts.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Kirjallisuuden- ja kulttuurintutkimus on viimeisten kolmen vuosikymmenen aikana tullut yhä enenevässä määrin tietoiseksi tieteen ja taiteen suhteen monimutkaisesta luonteesta. Nykyään näiden kahden kulttuurin tutkimus muodostaa oman kenttänsä, jolla niiden suhdetta tarkastellaan ennen kaikkea dynaamisena vuorovaikutuksena, joka heijastaa kulttuurimme kieltä, arvoja ja ideologisia sisältöjä. Toisin kuin aiemmat näkemykset, jotka pitävät tiedettä ja taidetta toisilleen enemmän tai vähemmän vastakkaisina pyrkimyksinä, nykytutkimus lähtee oletuksesta, jonka mukaan ne ovat kulttuurillisesti rakentuneita diskursseja, jotka kohtaavat usein samankaltaisia todellisuuden mallintamiseen liittyviä ongelmia, vaikka niiden käyttämät metodit eroavatkin toisistaan. Väitöskirjani keskittyy yllä mainitun suhteen osa-alueista popularisoidun tietokirjallisuuden (muun muassa Paul Davies, James Gleick ja Richard Dawkins) käyttämän kielen ja luonnontieteistä ideoita ammentavan kaunokirjallisuuden (muun muassa Jeanette Winterson, Tom Stoppard ja Richard Powers) hyödyntämien keinojen tarkasteluun nojautuen yli 30 teoksen kattavaa aineistoa koskevaan tyylin ja teemojen tekstianalyysiin. Populaarin tietokirjallisuuden osalta tarkoituksenani on osoittaa, että sen käyttämä kieli rakentuu huomattavassa määrin sellaisille rakenteille, jotka tarjoavat mahdollisuuden esittää todellisuutta koskevia argumentteja mahdollisimman vakuuttavalla tavalla. Tässä tehtävässä monilla klassisen retoriikan määrittelemillä kuvioilla on tärkeä rooli, koska ne auttavat liittämään sanotun sisällön ja muodon tiukasti toisiinsa: retoristen kuvioiden käyttö ei näin ollen edusta pelkkää tyylikeinoa, vaan se myös usein kiteyttää argumenttien taustalla olevat tieteenfilosofiset olettamukset ja auttaa vakiinnuttamaan argumentoinnin logiikan. Koska monet aikaisemmin ilmestyneistä tutkimuksista ovat keskittyneet pelkästään metaforan rooliin tieteellisissä argumenteissa, tämä väitöskirja pyrkii laajentamaan tutkimuskenttää analysoimalla myös toisenlaisten kuvioiden käyttöä. Osoitan myös, että retoristen kuvioiden käyttö muodostaa yhtymäkohdan tieteellisiä ideoita hyödyntävään kaunokirjallisuuteen. Siinä missä popularisoitu tiede käyttää retoriikkaa vahvistaakseen sekä argumentatiivisia että kaunokirjallisia ominaisuuksiaan, kuvaa tällainen sanataide tiedettä tavoilla, jotka usein heijastelevat tietokirjallisuuden kielellisiä rakenteita. Toisaalta on myös mahdollista nähdä, miten kaunokirjallisuuden keinot heijastuvat popularisoidun tieteen kerrontatapoihin ja kieleen todistaen kahden kulttuurin dynaamisesta vuorovaikutuksesta. Nykyaikaisen populaaritieteen retoristen elementtien ja kaunokirjallisuuden keinojen vertailu näyttää lisäksi, kuinka tiede ja taide osallistuvat keskusteluun kulttuurimme tiettyjen peruskäsitteiden kuten identiteetin, tiedon ja ajan merkityksestä. Tällä tavoin on mahdollista nähdä, että molemmat ovat perustavanlaatuisia osia merkityksenantoprosessissa, jonka kautta niin tieteelliset ideat kuin ihmiselämän suuret kysymyksetkin saavat kulttuurillisesti rakentuneen merkityksensä.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Although the principle of equal access to medically justified treatment has been promoted by official health policies in many Western health care systems, practices do not completely meet policy targets. Waiting times for elective surgery vary between patient groups and regions, and growing problems in the availability of services threaten equal access to treatment. Waiting times have come to the attention of decision-makers, and several policy initiatives have been introduced to ensure the availability of care within a reasonable time. In Finland, for example, the treatment guarantee came into force in 2005. However, no consensus exists on optimal waiting time for different patient groups. The purpose of this multi-centre randomized controlled trial was to analyse health-related quality of life, pain and physical function in total hip or knee replacement patients during the waiting time and to evaluate whether the waiting time is associated with patients health outcomes at admission. This study also assessed whether the length of waiting time is associated with social and health services utilization in patients awaiting total hip or knee replacement. In addition, patients health-related quality of life was compared with that of the general population. Consecutive patients with a need for a primary total hip or knee replacement due to osteoarthritis were placed on the waiting list between August 2002 and November 2003. Patients were randomly assigned to a short waiting time (maximum 3 months) or a non-fixed waiting time (waiting time not fixed in advance, instead the patient followed the hospitals routine practice). Patients health-related quality of life was measured upon being placed on the waiting list and again at hospital admission using the generic 15D instrument. Pain and physical function were evaluated using the self-report Harris Hip Score for hip patients and a scale modified from the Knee Society Clinical Rating System for knee patients. Utilization measures were the use of home health care, rehabilitation and social services, physician visits and inpatient care. Health and social services use was low in both waiting time groups. The most common services used while waiting were rehabilitation services and informal care, including unpaid care provided by relatives, neighbours and volunteers. Although patients suffered from clear restrictions in usual activities and physical functioning, they seemed primarily to lean on informal care and personal networks instead of professional care. While longer waiting time did not result in poorer health-related quality of life at admission and use of services during the waiting time was similar to that at the time of placement on the list, there is likely to be higher costs of waiting by people who wait longer simply because they are using services for a longer period. In economic terms, this would represent a negative impact of waiting. Only a few reports have been published of the health-related quality of life of patients awaiting total hip or knee replacement. These findings demonstrate that, in addition to physical dimensions of health, patients suffered from restrictions in psychological well-being such as depression, distress and reduced vitality. This raises the question of how to support patients who suffer from psychological distress during the waiting time and how to develop strategies to improve patients initiatives to reduce symptoms and the burden of waiting. Key words: waiting time, total hip replacement, total knee replacement, health-related quality of life, randomized controlled trial, outcome assessment, social service, utilization of health services

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The immune system has to recognize and destroy abnormal or infected cells to maintain homeostasis. Natural killer (NK) cells directly recognize and kill transformed or virus-infected cells without prior sensitization. We have studied both virus-infected and tumor cells in order to identify the target structures involved in triggering NK activity. Mouse/human cell hybrids containing various human chromosomes were used as targets. The human chromosome responsible for activating NK cell killing was identified to chromosome number 6. The results suggest that activated NK cells recognize ligands that are encoded on human chromosome 6. We showed that the ligand on the target cell side was intercellular adhesion molecule 2 (ICAM-2). There was no difference in the level of expression of ICAM-2, however, but a drastic difference was seen in the distribution of the molecule: ICAM-2 was evenly distributed on the surface of the NK-resistant cells, but almost totally redistributed to the tip of uropods, bud-like extensions, which were absent from the parental cells. Interestingly, the gene coding for cytoskeletal linker protein ezrin has been localized to human chromosome 6, and there was a colocalization of ezrin and ICAM-2 in the uropods. Furthermore, the transfected human ezrin into NK cell-resistant cells induced uropod formation, ICAM-2 and ezrin redistribution to newly formed uropods, and sensitized target cells to NK cell killing. These data reveal a novel form of NK cell recognition: target structures are already present on normal cells; they become detectable only after abnormal redistribution into hot spots on the target cell membrane. NK cells are central players in the defence against virus infections. They inhibit the spread of infection, allowing time for specific immune responses to develop. The virus-proteins that directly activate human NK cell killing are largely unknown. We studied the sensitivity of virus-specific early proteins of Semliki Forest virus (SFV) to NK killing. The viral non-structural proteins (nsP1-4) translated early in the virus cycle were transfected in NK-resistant cells. Viral early gene nsP1 alone efficiently sensitized target cells to NK activity, and the tight membrane association of nsP1 seems to be critical in the triggering of NK killing. NsP1 protein colocalized with (redistributed) ezrin in filopodia-like structures to which the NK cells were bound. The results suggest that also in viral infections NK cells react to rapid changes in membrane topography. Based on the results of this thesis, a new model of target cell recognition of NK cells can be suggested: reorganization of the cytoskeleton induces alterations in cell surface topography, and this new pattern of surface molecules is recognized as "altered-self".

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Conservation and sustainable management of tropical forests needs a holistic approach: in addition to ecological concerns, socio-economic issues including cultural aspects must be taken into consideration. An ability to adapt practices is a key to successful collaborative natural resource management. Achieving this requires local participation and understanding of local conceptions of the environment. This study examined these issues in the context of northern Thailand. Northern uplands are the home of much of the remaining natural forest in Thailand and several ethnic minority groups commonly referred to as hill tribes. The overall purpose of this study was to grasp a regional view of an ethnically diverse forested area and to elicit prospects to develop community forestry for conservation purposes and for securing people s livelihood. Conservation was a central goal of management as the forests in the area were largely designated as protected. The aim was to study local perceptions, objectives, values and practices of forest management, under the umbrella of the concept environmental literacy, as well as the effects of forest policy on community management goals and activities. Environmental literacy refers to holistic understanding of the environment. It was used as a tool to examine people s views, interests, knowledge and motivation associated to forests. The material for this study was gathered in six villages in Chiang Mai Province. Three minority groups were included in the study, the Karen, Hmong and Lawa, and also the Thai. Household and focus group interviews were conducted in the villages. In addition, officials at district, regional and national levels, workers of non-governmental organisations, and academics were interviewed, and some data were gathered from the students of a local school. The results showed that motivation for protecting the forests existed among each ethnic group studied. This was a result of culture and traditions evolved in the forest environment but also of a need to adapt to a changed situation and environment and to outside pressures. The consequences of deforestation were widely agreed on in the villages, and the impact of socio-economic changes on the forests and livelihood was also recognised. The forest was regarded as a source of livelihood providing land, products and services essential to the people inhabiting rural uplands. Traditions, fire control, cooperation, reforestation, separation of protected and utilisable areas, and rules were viewed as central for conservation. For the villagers, however, conservation meant sustainable use, whereas the government has tended to prefer strict restrictions on forest resource use. Thus, conflicts had arisen. Between communities, cooperation was more dominant than conflict. The results indicated that the heterogeneity of forest dwellers, although it has to be recognised, should not be overemphasised: ethnic diversity can be considered as no major obstacle for successful community forestry. Collaborative management is particularly important in protected areas in order to meet the conservation goals while providing opportunities for livelihood. Forest management needs more positive incentives and increased dialogue.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Establishment of Pinus kesiya Roy. ex Gord. plantations in Thailand began in the 1960s by the Royal Forest Department. The aim was to reforest abandoned swidden areas and grasslands in order to reduce erosion and to produce timber and fuel wood. Today there are about 150, 000 ha of P. kesiya plantations in northern Thailand. Most of these plantations cannot be harvested due to a national logging ban. Previous studies have suggested that Pinus kesiya plantations posses a capability as a foster environment for native broadleaved tree species, but little is known about the extent of regeneration in these plantations. The general aim of the study was to clarify the extent of forest regeneration and interactions behind it in Pinus kesiya plantations of the Ping River basin, northern Thailand. Based on the results of this study and previous literature, forest management proposals were produced for the area studied. In four different pine plantation areas, a total of seven plantations were assessed using systematic data collection with clustered circular sample plots. Vegetation and environmental data were statistically analysed, so as to recognise the key factors affecting regeneration. Regeneration had occurred in all plantations studied. Regeneration of broadleaved trees was negatively affected by forest fire and canopy coverage. A high basal area of mature broadleaved trees affected the regeneration process positively. Forest fire disturbance had a strong effect also on plantation structure and species composition. Because of an unclear future forest management setting as regards forest laws in Thailand, a management system that enables various future utilisation possibilities and emphasises local participation is recommended for P. kesiya watershed platations of northern Thailand.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This thesis studies the use of natural resources for leisure time activities. The method used is Material Input per Service Unit (MIPS method). Leisure time has an increasing effect on the material flows of households, and that way has a bigger pressure on the environment. The most popular way of spending spare time in Finland is to watch TV and to listen to music or radio. Regardless of these, this thesis takes a closer look at boating, playing a musical instrument and visiting a theatre and tries to quantify their material flows. MIPS calculations of this thesis are case-studies and do not tell the whole truth about the hobbies. The aim was to have an overview about the magnitude of the activities. In the boating calculations, inside the system boundaries there are the boat itself, transport of the boat, outboard motor, gasoline consumption of the outboard motor, travelling to and from the harbour, and the harbour infrastructure. Calculations of playing a music instrument consider the instrument itself, music school and its maintenance, and travelling to the school. In the case of theatre the included things are theatre house and its maintenance, decor and costumes of the plays, transport of the decor, and travelling of the audience. The results of this thesis suggest that the biggest material flow of boating comes from travelling to and from the harbour and from the harbour infrastructure. The gasoline consumption of the outboard motor also makes a difference. One hour of boating with a rowing boat consumes 1 kg of abiotic materials. Boating with an outboard motorboat consumes astonishing 113 kg of abiotic resources. Visiting a music lesson for one hour consumes 9 kg of abiotic resources when travelling there by bus. One hour in a theatre play consumes 17 kg of abiotic materials when travelling by bus. Transport has a significant role on the resource consumption of leisure time activities.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tutkielmassa tarkastellaan liikuntaharrastusten luonnonvarojen kulutusta MIPS (material input per service unit, suom. materiaalipanos palvelusuoritetta kohden) -menetelmällä. MIPS-menetelmä perustuu ekotehokkuusajatteluun ja sen tavoitteena on suhteuttaa tuotteen tai palvelun elinkaaren aikainen luonnonvarojen kulutus siitä saatavaan palveluun. Tässä tutkimuksessa tarkastellaan liikuntaharrastusten materiaalivirtoja erilaisissa liikuntapaikoissa yhden henkilön harrastetuntia kohden. Tarkasteltavia liikuntapaikkoja ovat kevyen liikenteen väylä, kuntorata, liikuntasali ja -halli, jäähalli, uimahalli, kuntokeskus sekä lämmitetty ja lämmittämätön tekonurmikenttä. Tutkielman laskelmat perustuvat pääosin tapaustutkimuksiin suomalaisista liikuntapaikoista. Laskelmissa on huomioitu liikuntapaikalle matkustaminen, liikuntapaikan rakentaminen sekä sen ylläpito ja käyttö. Tarkasteltujen liikuntaharrastusten abioottisten luonnonvarojen kulutus vaihteli 1,7 28 kg:n välillä yhden henkilön harrastetuntia kohden. Abioottisten luonnonvarojen kulutukseen vaikutti eniten liikuntapaikalle matkustaminen. Tarkastelluista liikuntaharrastuksista eniten abioottisia luonnonvaroja ja ilmaa kulutti uimahallissa uiminen. Kuntoradoilla ja kevyen liikenteen väylillä harrastettavien ulkoilulajien MIPS-luvut olivat alhaisimmat. Liikuntaharrastukset erosivat toisistaan eniten veden kulutuksessa, jonka MIPS-luvut vaihtelivat 40 ja 1400 kg:n välillä. Korkein veden MIPS-luku oli jäähallissa tapahtuvalla liikunnalla. Ilman kulutus liikuntaharrastuksissa oli 0,1 6,2 kg harrastetuntia kohden. Tulosten perusteella liikuntaharrastusten luonnonvarojen kulutusta voitaisiin tehokkaimmin vähentää kulkemalla liikuntapaikalle henkilöauton sijaan julkisilla kulkuneuvoilla ja hyödyntämällä lähiympäristön tarjoamia liikuntapaikkoja. Myös liikuntapaikkojen kävijämäärien maksimoiminen on tärkeää harrastetunnille kohdistuvien materiaalivirtojen pienentämiseksi. Tutkielma on toteutettu osana FIN-MIPS Kotitalous tutkimushanketta.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper both documentary and natural proxy data have been used to improve the accuracy of palaeoclimatic knowledge in Finland since the 18th century. Early meteorological observations from Turku (1748-1800) were analyzed first as a potential source of climate variability. The reliability of the calculated mean temperatures was evaluated by comparing them with those of contemporary temperature records from Stockholm, St. Petersburg and Uppsala. The resulting monthly, seasonal and yearly mean temperatures from 1748 to 1800 were compared with the present day mean values (1961-1990): the comparison suggests that the winters of the period 1749-1800 were 0.8 ºC colder than today, while the summers were 0.4 ºC warmer. Over the same period, springs were 0.9 ºC and autumns 0.1 ºC colder than today. Despite their uncertainties when compared with modern meteorological data, early temperature measurements offer direct and daily information about the weather for all months of the year, in contrast with other proxies. Secondly, early meteorological observations from Tornio (1737-1749) and Ylitornio (1792-1838) were used to study the temporal behaviour of the climate-tree growth relationship during the past three centuries in northern Finland. Analyses showed that the correlations between ring widths and mid-summer (July) temperatures did not vary significantly as a function of time. Early (June) and late summer (August) mean temperatures were secondary to mid-summer temperatures in controlling the radial growth. According the dataset used, there was no clear signature of temporally reduced sensitivity of Scots pine ring widths to mid-summer temperatures over the periods of early and modern meteorological observations. Thirdly, plant phenological data with tree-rings from south-west Finland since 1750 were examined as a palaeoclimate indicator. The information from the fragmentary, partly overlapping, partly nonsystematically biased plant phenological records of 14 different phenomena were combined into one continuous time series of phenological indices. The indices were found to be reliable indicators of the February to June temperature variations. In contrast, there was no correlation between the phenological indices and the precipitation data. Moreover, the correlations between the studied tree-rings and spring temperatures varied as a function of time and hence, their use in palaeoclimate reconstruction is questionable. The use of present tree-ring datasets for palaeoclimate purposes may become possible after the application of more sophisticated calibration methods. Climate variability since the 18th century is perhaps best seen in the fourth paper study of the multiproxy spring temperature reconstruction of south-west Finland. With the help of transfer functions, an attempt has been made to utilize both documentary and natural proxies. The reconstruction was verified with statistics showing a high degree of validity between the reconstructed and observed temperatures. According to the proxies and modern meteorological observations from Turku, springs have become warmer and have featured a warming trend since around the 1850s. Over the period of 1750 to around 1850, springs featured larger multidecadal low-frequency variability, as well as a smaller range of annual temperature variations. The coldest springtimes occurred around the 1840s and 1850s and the first decade of the 19th century. Particularly warm periods occurred in the 1760s, 1790s, 1820s, 1930s, 1970s and from 1987 onwards, although in this period cold springs occurred, such as the springs of 1994 and 1996. On the basis of the available material, long-term temperature changes have been related to changes in the atmospheric circulation, such as the North Atlantic Oscillation (February-June).