Reduced bone mineral density in men after heart transplantation

Heart transplantation is associated with rapid bone loss and an increased prevalence and incidence of fractures. The aim of the present study was to compare the bone mineral density (BMD) of 30 heart transplant (HT) recipients to that of 31 chronic heart failure (CHF) patients waiting for transplantation and to determine their biochemical markers of bone resorption and hormone levels. The BMD of lumbar spine and proximal femur was determined by dual-energy X-ray absorptiometry. Anteroposterior and lateral radiographs of the thoracic and lumbar spine were also obtained. The mean age of the two groups did not differ significantly. Mean time of transplantation was 25.4 ± 21.1 months (6 to 88 months). Except for the albumin levels, which were significantly higher, and magnesium levels, which were significantly lower in HT patients when compared to CHF patients, all other biochemical parameters and hormone levels were within the normal range and similar in the two groups. Both groups had lower BMD of the spine and proximal femur compared to young healthy adults. However, the mean BMD of HT patients was significantly lower than in CHF patients at all sites studied. Bone mass did not correlate with time after transplantation or cumulative dose of cyclosporine A. There was a negative correlation between BMD and the cumulative dose of prednisone. These data suggest that bone loss occurs in HT patients mainly due to the use of corticosteroids and that in 30% of the patients it can be present before transplantation. It seems that cyclosporine A may also play a role in this loss.

Design of Personalization of Massive Open Online Courses

Massive Open Online Courses have been in the center of attention in the recent years. However, the main problem of all online learning environments is their lack of personalization according to the learners’ knowledge, learning styles and other learning preferences. This research explores the parameters and features used for personalization in the literature and based on them, evaluates to see how well the current MOOC platforms have been personalized. Then, proposes a design framework for personalization of MOOC platforms that fulfills most of the personalization parameters in the literature including the learning style as well as personalization features. The result of an assessment made for the proposed design framework shows that the framework well supports personalization of MOOCs.

Age effects on the pharmacokinetics of tityustoxin from Tityus serrulatus scorpion venom in rats

The pharmacokinetics of scorpion venom and its toxins has been investigated in experimental models using adult animals, although, severe scorpion accidents are associated more frequently with children. We compared the effect of age on the pharmacokinetics of tityustoxin, one of the most active principles of Tityus serrulatus venom, in young male/female rats (21-22 days old, N = 5-8) and in adult male rats (150-160 days old, N = 5-8). Tityustoxin (6 µg) labeled with 99mTechnetium was administered subcutaneously to young and adult rats. The plasma concentration vs time data were subjected to non-compartmental pharmacokinetic analysis to obtain estimates of various pharmacokinetic parameters such as total body clearance (CL/F), distribution volume (Vd/F), area under the curve (AUC), and mean residence time. The data were analyzed with and without considering body weight. The data without correction for body weight showed a higher Cmax (62.30 ± 7.07 vs 12.71 ± 2.11 ng/ml, P < 0.05) and AUC (296.49 ± 21.09 vs 55.96 ± 5.41 ng h-1 ml-1, P < 0.05) and lower Tmax (0.64 ± 0.19 vs 2.44 ± 0.49 h, P < 0.05) in young rats. Furthermore, Vd/F (0.15 vs 0.42 l/kg) and CL/F (0.02 ± 0.001 vs 0.11 ± 0.01 l h-1 kg-1, P < 0.05) were lower in young rats. However, when the data were reanalyzed taking body weight into consideration, the Cmax (40.43 ± 3.25 vs 78.21 ± 11.23 ng kg-1 ml-1, P < 0.05) and AUC (182.27 ± 11.74 vs 344.62 ± 32.11 ng h-1 ml-1, P < 0.05) were lower in young rats. The clearance (0.03 ± 0.002 vs 0.02 ± 0.002 l h-1 kg-1, P < 0.05) and Vd/F (0.210 vs 0.067 l/kg) were higher in young rats. The raw data (not adjusted for body weight) strongly suggest that age plays a pivotal role in the disposition of tityustoxin. Furthermore, our results also indicate that the differences in the severity of symptoms observed in children and adults after scorpion envenomation can be explained in part by differences in the pharmacokinetics of the toxin.

Aging reduces the primary humoral response and the in vitro cytokine production in mice

Aging is accompanied by a decrease in several physiological functions that make older individuals less responsive to environmental challenges. In the present study, we analyzed the immune response of female BALB/c mice (N = 6) of different ages (from 2 to 96 weeks) and identified significant age-related alterations. Immunization with hapten-protein (trinitrophenyl-bovine serum albumin) conjugates resulted in lower antibody levels in the primary and secondary responses of old mice (72 weeks old). Moreover, young mice (2, 16, and 32 weeks old) maintained specific antibodies in their sera for longer periods after primary immunization than did old mice. However, a secondary challenge efficiently induced memory in old mice, as shown by the increased antibody levels in their sera. The number of CD4+ and CD8+ T cells in the spleen increased until 8 weeks of age but there was no change in the CD4+/CD8+ ratio with aging. Splenic T cells from old mice that had or had not been immunized were less responsive to concanavalin-A and showed reduced cytokine production compared to young mice (IL-2: 57-127 vs 367-1104 pg/mL, IFN-g: 2344-12,836 vs 752-23,106 pg/mL and IL-10: 393-2172 vs 105-2869 pg/mL in old and young mice, respectively). These data suggest that there are significant changes in the organization of the immune system throughout life. However, the relevance of these alterations for the functioning of the immune system is unknown.

Kirkkoherrojen osaamisen johtamisen kehittäminen. Case: Lappeenrannan seurakuntayhtymä

Tässä pro gradu -tutkielmassa tarkastellaan osaamisen johtamista Lappeenrannan seurakuntayhtymässä kirkkoherrojen näkökulmasta. Tutkimuksen tavoitteena on selvittää, miten kirkkoherrojen osaamisen johtamista voidaan kehittää. Tutkielmassa tarkastellaan kirkkoherrojen roolia ja tehtäviä sekä käytössä olevia osaamisen kehittämisen menetelmiä. Lisäksi paneudutaan osaamisen johtamisen haasteisiin ja hengellisen työn erityispiirteisiin. Tutkimus toteutettiin kvalitatiivisena tapaustutkimuksena. Tutkimuksen empiirinen aineisto kerättiin haastattelemalla Lappeenrannan seurakuntayhtymän kaikkia viittä kirkkoherraa. Tutkimuksen tulosten perusteella voidaan havaita, että osaamisen johtaminen ei seurakuntayhtymässä ole kovin suunnitelmallista tai pitkäjänteistä. Tulevaisuuden haasteina nähdään etenkin kirkon yhteiskunnallisen aseman muuttuminen ja jäsenmäärän väheneminen. Suurimpana osaamisen johtamiseen liittyvänä haasteena kirkkoherrat kokevat ajan puutteen. Kirkkoherrojen näkemyksissä omasta roolistaan osaamisen johtamisessa korostuvat kokonaisuuksien hallinta, yleisten suuntaviivojen määrittely ja yhteisen suunnan selkiyttäminen. Osaamisen kehittämisen menetelmiä on käytössä monia, mutta pääpaino on keskusteluissa ja palavereissa sekä koulutuksissa. Hengellisen työn erityispiirteinä nähdään kirkon erityinen arvomaailma sekä uskon henkilökohtainen ja intiimi olemus. Osaaminen tulisi seurakuntayhtymässä ottaa tietoiseksi johtamisen kohteeksi. Kirkkoherrat voivat kehittää omaa osaamisen johtamistaan parantamalla tietoisuutta esimiehen eri rooleista ja tehtäväkentistä. Erityisesti yksilöiden oppimisen tukemiseen ja oppimista edistävän ilmapiirin luomiseen tulisi tulevaisuudessa kiinnittää huomiota. Osaamisen kehittämisen menetelmistä suositeltavia ovat etenkin erilaiset työssä oppimisen keinot.

Modification of commercial poly-lactide for extrusion coated food packaging applications

Poly-L-lactide (PLLA) is a widely used sustainable and biodegradable alternative to replace synthetic non-degradable plastic materials in the packaging industry. Conversely, its processing properties are not always optimal, e.g. insufficient melt strength at higher temperatures (necessary in extrusion coating processes). This thesis reports on research to improve properties of commercial PLLA grade (3051D from NatureWorks), to satisfy and extend end-use applications, such as food packaging by blending with modified PLLA. Adjustment of the processability by chain branching of commercial poly-L-lactide initiated by peroxide was evaluated. Several well-defined branched structures with four arms (sPLLA) were synthesized using pentaerythritol as a tetra-functional initiator. Finally, several block copolymers consisting of polyethylene glycol and PLLA (i.e. PEGLA) were produced to obtain a well extruded material with improved heat sealing properties. Reactive extrusion of poly-L-lactide was carried out in the presence of 0.1, 0.3 and 0.5 wt% of various peroxides [tert-butyl-peroxybenzoate (TBPB), 2,5-dimethyl-2,5-(tert-butylperoxy)-hexane (Lupersol 101; LOL1) and benzoyl peroxide (BPO)] at 190C. The peroxide-treated PLLAs showed increased complex viscosity and storage modulus at lower frequencies, indicating the formation of branched/cross linked architectures. The material property changes were dependent on the peroxide, and the used peroxide concentration. Gel fraction analysis showed that the peroxides, afforded different gel contents, and especially 0.5 wt% peroxide, produced both an extremely high molar mass, and a cross linked structure, not perhaps well suited for e.g. further use in a blending step. The thermal behavior was somewhat unexpected as the materials prepared with 0.5 wt% peroxide showed the highest ability for crystallization and cold crystallization, despite substantial cross linking. The peroxide-modified PLLA, i.e. PLLA melt extruded with 0.3 wt% of TBPB and LOL1 and 0.5 wt% BPO was added to linear PLLA in ratios of 5, 15 and 30 wt%. All blends showed increased zero shear viscosity, elastic nature (storage modulus) and shear sensitivity. All blends remained amorphous, though the ability of annealing was improved slightly. Extrusion coating on paperboard was conducted with PLLA, and peroxide-modified PLLA blends (90:10). All blends were processable, but only PLLA with 0.3 wt% of LOL1 afforded a smooth high quality surface with improved line speed. Adhesion levels between fiber and plastic, as well as heat seal performance were marginally reduced compared with pure 3051D. The water vapor transmission measurements (WVTR) of the blends containing LOL1 showed acceptable levels, only slightly lower than for comparable PLLA 3051D. A series of four-arm star-shaped poly-L-lactide (sPLLA) with different branch length was synthesized by ring opening polymerization (ROP) of L-lactide using pentaerythritol as initiator and stannous octoate as catalyst. The star-shaped polymers were further blended with its linear resin and studied for their melt flow and thermal properties. Blends containing 30 wt% of sPLLA with low molecular weight (30 wt%; Mwtotal: 2500 g mol-1 and 15000 g mol-1) showed lower zero shear viscosity and significantly increased shear thinning, while at the same time slightly increased crystallization of the blend. However, the amount of crystallization increased significantly with the higher molecular weight sPLLA, therefore the star-shaped structure may play a role as nucleating agent. PLLA-polyethylene glycol–PLLA triblock copolymers (PEGLA) with different PLLA block length were synthesized and their applicability as blends with linear PLLA (3051D NatureWorks) was investigated with the intention of improving heat-seal and adhesion properties of extrusion-coated paperboard. PLLA-PEG-PLLA was obtained by ring opening polymerization (ROP) of L-lactide using PEG (molecular weight 6000 g mol-1) as an initiator, and stannous octoate as catalyst. The structures of the PEGLAs were characterized by proton nuclear magnetic resonance spectroscopy (1H-NMR). The melt flow and thermal properties of all PEGLAs and their blends were evaluated using dynamic rheology, and differential scanning calorimeter (DSC). All blends containing 30 wt% of PEGLAs showed slightly higher zero shear viscosity, higher shear thinning and increased melt elasticity (based on tan delta). Nevertheless, no significant changes in thermal properties were distinguished. High molecular weight PEGLAs were used in extrusion coating line with 3051D without problems.

Edistyneen oppijan suomen konstruktiopiirteitä korpusvetoisesti: avainrakenneanalyysi

Ensikielen jälkeen opittavan kielen tutkimusta ja suomi toisena kielenä alaa sen osana ovat koko niiden olemassaolon ajan hallinneet samat peruskysymykset: millaista oppiminen on eri vaiheissa ja eri ympäristöissä, sekä mikä oppimisessa on yleistä ja toisaalta mikä riippuu opittavasta kielestä ja oppijoiden kielitaustasta. Sähköisten oppijankielen tutkimusaineistojen eli korpusten lisääntymisen myötä tutkijat voivat aiempaa helpommin tutkia näitä ilmiöitä määrällisesti ja tarkastella oppijankielen sisäistä vaihtelua ja sen suhdetta tyypilliseen ensikieliseen kielenkäyttöön kielen eri osa-alueilla käyttöpohjaisesti eli todelliseen kielenkäyttöön pohjautuen. Tekninen kehitys on tuonut mukanaan aineisto- eli korpusvetoisuuden kaltaisia uusia tapoja lähestyä tutkimusaineistoa, jolloin tyypillisiä tutkimuskysymyksiä ”Miksi?” ja ”Miten?” edeltää kysymys: ”Mikä?”. Tässä väitöskirjassa tarkastellaan edistyneiden suomenoppijoiden kirjoitettua akateemista kieltä ja suhteutetaan suomen oppimiselle ominaisia seikkoja käyttöpohjaisen mallin perusolettamuksiin. Aineisto on suomea toisena kielenä käyttävien opiskelijoiden tenttivastauksia, ja se on osa Edistyneiden suomenoppijoiden korpusta. Tutkimus on osin metodologinen, sillä väitöskirjassa esitellään ja siinä sovelletaan uutta korpusvetoista avainrakenneanalyysi-menetelmää, jonka avulla aineistoa lähestytään ilman hypoteeseja siitä, mitkä kielen ilmiöt ovat ominaisia edistyneelle oppijansuomelle. Tutkimus kuuluu kieliopin tutkimuksen piiriin, ja se nojaa kognitiivisen konstruktiokieliopin ajatukseen abstraktiudeltaan vaihtelevista konstruktioista kielijärjestelmän perusyksiköinä. Tulokset puoltavat menetelmän sovellettavuutta kielen oppimisen tutkimukseen, sillä sen avulla kyettiin tunnistamaan konstruktioita, jotka erottavat edistyneitä oppijoita ensikielisistä kirjoittajista (esim. modaaliset verbiketjut), eri ensikieliä puhuvia suomenoppijoita (esim. konjunktiot) sekä konstruktioita, joiden käyttö muuttuu ajan kuluessa (esim. preteriti ja preesens). Monet havaitut erot ovat akateemisen kirjoittamisen erityispiirteitä, mikä tukee ajatusta kielen käyttö- ja kontekstikohtaisesta oppimisesta. Tuloksia voidaan yhtäältä soveltaa akateemisen kielitaidon opetuksessa. Toisaalta menetelmää voidaan käyttää kielenoppimisen tutkimuksen ohella uusien näkökulmien kartoittamiseksi erilaisten tai eri-ikäisten tekstien tyypillisten ominaisuuksien ja erojen tutkimuksessa.

Functionalisation of spruce O-acetyl-galactoglucomannans for barrier and composite applications

The increasing use of energy, food, and materials by the growing population in the world is leading to the situation where alternative solutions from renewable carbon resources are sought after. The growing use of plastics depends on the raw-oil production while oil refining are politically governed and required for the polymer manufacturing is not sustainable in terms of carbon footprint. The amount of packaging is also increasing. Packaging is not only utilising cardboard and paper, but also plastics. The synthetic petroleum-derived plastics and inner-coatings in food packaging can be substituted with polymeric material from the renewable resources. The trees in Finnish forests constitute a huge resource, which ought to be utilised more effectively than it is today. One underutilised component of the forests is the wood-derived hemicelluloses, although Spruce Oacetyl-galactoglucomannans (GGMs) have previously shown high potential for material applications and can be recovered in large scale. Hemicelluloses are hydrophilic in their native state, which restrains the use of them for food packaging as non-dry item. To cope with this challenge, we intended to make GGMs more hydrophobic or amphiphilic by chemical grafting and consequently with the focus of using them for barrier applications. Methods of esterification with anhydrides and cationic etherification with a trimethyl ammonium moiety were established. A method of controlled synthesis to obtain the desired properties by the means of altering temperature, reaction time, the quantity of the reagent, and even the solvent for purification of the products was developed. Numerous analytical tools, such as NMR, FTIR, SEC-MALLS/RI, MALDI-TOF-MS, RP-HPLC and polyelectrolyte titration were used to evaluate the products from different perspectives and to acquire parallel proofs of their chemical structure. Modified GGMs with different degree of substitution and the correlating level of hydrophobicity was applied as coatings on cartonboard and on nanofibrillated cellulose-GGM films to exhibit barrier functionality. The water dispersibility in processing was maintained with GGM esters with low DS. The use of chemically functionalised GGM was evaluated for the use as barriers against water, oxygen and grease for the food packaging purposes. The results show undoubtedly that GGM derivatives exhibit high potential to function as a barrier material in food packaging.

Näkökulmia 3D-tulostuksen opetukseen ja koulutukseen

Additive manufacturing, or 3D printing, is globally one of most interesting area in developing of manufacturing technologies. This technology is suitable for fabrication off industrial products and it interests actors in fields of computer sciences, economics, medical sciences and design&arts. Additive manufacturing is often referred as third industrial revolution: first revolution was invention of steam engines in 18th century and second was industrial revolution started by Henry Ford in 1920s. Companies should be able to test suitability of their products for additive manufacturing and 3D printing but also how much better products could be when products are totally re-designed so that all potential of this new technology can be utilized. This is where education has its importance; new generations who enter working life should be educated to know of additive manufacturing and 3D printing, its advantages but also of it limits. There has to be also possibility to educate industry and people already working there, so that industrial implementation could be done successfully. This is especially very valid for Finland. Education is strongly needed so that Finnish industry can maintain its competence in global markets. Role of education is extremely important when a new technology is industrially implemented. Additive manufacturing and 3D printing offers freedom to design new products, production and generally ways of doing things. Development, planning and execution of education for additive manufacturing and 3D printing is challenging as this area develops very fast. New innovations are coming almost every month. Planning of education for additive manufacturing and 3D printing requires collection pieces of data from various of sources. Additive manufacturing and 3D printing industry and its development has to be followed frequently, and material for additive manufacturing and 3D printing has to be renewed frequently.

Liiketoimintayksikön materiaalihallinnan nykytila ja sen tehostaminen materiaalien suoratoimituksilla

Tutkimuksen tarkoituksena on tutkia kansainvälisesti toimivan konserniyrityksen yhden liiketoimintayksikön materiaalinhallinnan ja siihen liittyvien toimintojen nykytilaa. Lisäksi tutkimuksessa selvitetään, miten materiaalinhallintaa varastoinnin osalta voidaan kehittää suoratoimitusmallin periaatetta hyödyntäen ja mitä säästöpotentiaaleja tämän kaltaiseen malliin liittyy kohdeorganisaation toimintaympäristö huomioiden. Tutkimuksen teoriaosion lähdeaineisto koostuu materiaalinhallinnan perusteosten lisäksi tieteellisistä artikkelijulkaisuista. Käytännönosuuden aineisto pohjautuu kohdeorganisaatiossa käytyihin keskusteluihin, tuotannonohjausjärjestelmästä saatuun tietoon ja omiin havaintoihin. Nykytilanteen analyysissä selvisi, että kohdeorganisaation varastointiin liittyy tehostamispotentiaalia erityisesti tila-, käsittely, ja työkustannusten osalta. Kohdeorganisaation varastoinnin tehostamista tutkittiin suoratoimitusmallin avulla. Suoratoimitusmallissa materiaalit eivät kierrä kohdeorganisaation pitämän välivaraston kautta, vaan ne toimitetaan toimittajan tiloista suoraan tuotannon välittömään tarpeeseen. Mallin avulla voidaan jakaa toimittajien kanssa sellaisia resursseja, joita molempien toiminta vaatii ja täten vapauttaa nykyistä varastointitilaa ja keventää sisäisen logistiikan kuormaa. Suoratoimitusmallin liittyvien hyötyjen kannalta on oleellista, että malliin valitaan sellaiset materiaalit, jotka sisältävät eniten potentiaalia niin säästö- kuin soveltuvuusnäkökulmasta. Valittujen kriteerien avulla kohdeorganisaation hankkimista materiaaleista löydettiin joukko materiaaleja, joiden avulla pystyttiin osoittamaan, että suoratoimitusmallin avulla on mahdollista saavuttaa kustannussäätöjä varastoinnin osalta.

The impact of scheduling on the implementation of the new Ontario curriculum: teachers' perceptions /

This qualitative study explored secondary teachers' perceptions of scheduling in relation to pedagogy, curriculum, and observation of student learning. Its objective was to determine the best way to organize the scheduling for the delivery of Ontario's new 4-year curriculum. Six participants were chosen. Two were teaching in a semestered timetable, 1 in a traditional timetable, and 3 had experience in both schedules. Participants related a pressure cooker "lived experience" with weaker students in the semester system experiencing a particularly harsh environment. The inadequate amount of time for review in content-heavy courses, gap scheduling problems, catch-up difficulties for students missing classes, and the fast pace of semestering are identified as factors negatively impacting on these students. Government testing adds to the pressure by shifting teachers' time and attention in the classroom from deeper learning to a superficial coverage of material, from curriculum as lived to curriculum as text to be covered. Scheduling choice should be available in public education to accommodate the needs of all students. Curriculum guidelines need to be revamped to reflect the content that teachers believe is necessary for a successful course delivery. Applied level courses need to be developed for students who are not academically inferior but learn differently.

A study on the role of the parent in educational decision making from the perspective of parents and teachers

ADeweyan (1916) democratic theoty ofeducation called for the participation ofall citizens in deliberating important educational issues to improve overall student learning. Thus, the move to include parents in educational decision making can be considered to be rooted in democratic principles. To gain greater insight into the issue ofparent involvement in educational decision making, one elementary school was studied and a triangulization method was employed in an attempt to clarify the important issues surrolUlding the move to include parents in the governance ofschools. The three methods to gain information included surveys, interviews, and documentation ofsignificant school events and related work. All ofthe parents and teachers ofthe school were surveyed, 10 parents and 6teachers were interviewed, and related school events were recorded. The survey design was modeled on the Parent Involvement Questionnaire (PIQ) created and reported on by Chavkin and Williams (1987). The results ofthe surveys were used as a guide for the interview questions. An interview outline was developed based on Seidman's (1991) open-ended approach and Patton's (1980) standardized open-ended interview style in which parents and teachers were asked about their experiences and opinions on anmnber ofparent involvement issues. Parents and teachers in this school indicated agreater interest in becoming more aware ofeducational issues such as school budget and school discipline policies. Although the parents indicated agreater interest in school matters and the teachers indicated awillingness to include parents in school matters, both the parents and teachers in this study perceived the role ofthe parent as advisory, not decision making. It was concluded that to ensure ameaningful and functional role for parellts as tlleir p811icipatioll ill educational matters evolves, SCllools must have a clear vision ofthe primary goal ofall schools, namely, to foster and nourish democratic citizens for ademocratic society (Glickman, 1993). Furthennore, intentional practices such as Purkey's (ad) 5-P Relay approach, based on a democratic theory and practice of education, will have to be employed in order to give parents an authentic voice in educational matters and provide an avenue for parents to acquire the necessary skills and lmowledge needed to do so. As schools, school boards, and the Ministry ofEducation implement parent involvement guidelines and policies, developmental needs ofeach school need to be considered to ensure the employment ofdemocratic practices not authoritarian mandates. Parent interest and involvement, at whatever level, should be an important element in the overall move to make schools part ofthe democratic society they were meant to be.

International volunteers at a Costa Rican organic farm : sheepish volunteers, proud tourists and unwitting developers

This thesis analyzes the practices and experiences of two groups of Canadian volunteers who visited the organic fanning and "alternative development" project ofFinca la Flor (FLF) in central Costa Rica. Using both participant observation and in-depth interviews with volunteers and other people involved with FLF, I examine volunteers' understandings of their involvement with the fann. I argue that three discursive fonnations are instrumental in shaping this particular volunteering encounter. Specifically, interpretation of these Canadian volunteers' experiences inspires the argument that the emerging practice of international volunteering (or voluntourism) exists at the intersection of discourses of development, volunteering and tourism, all of which both reflect and maintain problematic North-South relationships. The analysis shows that in spite ofFLF's construction as an (alternative / sustainable) international-development project, and in spite of volunteers' initial conceptualization of their trip as "volunteering," volunteers tend to act and describe their time at FLF in ways that look more like tourism than like volunteer labor or international development. Likewise, although FLF claims to principally be focused on alternative development, and merely to open up this authentic development space to volunteers for their participation, the organization in both practice and discourse seems primarily to construct a tourist experience and cater to the needs of foreigners as tourists. Discourses of development and volunteering do infonn the practices offann personnel and volunteers at FLF, but they become subordinated to the more dominant discourse of tourism as the volunteers' and fann management's ideals of development and volunteering capitulate to become focused on satisfying volunteers' (perceived or "real") touristic desires. The FLF participants I studied may have entered the encounter as volunteers, but they departed the site having been tourists.

The vocation of responsibility : a conceptual analysis of a modern idea

Please consult the paper edition of this thesis to read. It is available on the 5th Floor of the Library at Call Number: Z 9999 P55 N48 2004

The Role of Experience in the Organization and Refinement of Face Space

Adults code faces in reference to category-specific norms that represent the different face categories encountered in the environment (e.g., race, age). Reliance on such norm-based coding appears to aid recognition, but few studies have examined the development of separable prototypes and the way in which experience influences the refinement of the coding dimensions associated with different face categories. The present dissertation was thus designed to investigate the organization and refinement of face space and the role of experience in shaping sensitivity to its underlying dimensions. In Study 1, I demonstrated that face space is organized with regard to norms that reflect face categories that are both visually and socially distinct. These results provide an indication of the types of category-specific prototypes that can conceivably exist in face space. Study 2 was designed to investigate whether children rely on category-specific prototypes and the extent to which experience facilitates the development of separable norms. I demonstrated that unlike adults and older children, 5-year-olds rely on a relatively undifferentiated face space, even for categories with which they receive ample experience. These results suggest that the dimensions of face space undergo significant refinement throughout childhood; 5 years of experience with a face category is not sufficient to facilitate the development of separable norms. In Studies 3 through 5, I examined how early and continuous exposure to young adult faces may optimize the face processing system for the dimensions of young relative to older adult faces. In Study 3, I found evidence for a young adult bias in attentional allocation among young and older adults. However, whereas young adults showed an own-age recognition advantage, older adults exhibited comparable recognition for young and older faces. These results suggest that despite the significant experience that older adults have with older faces, the early and continuous exposure they received with young faces continues to influence their recognition, perhaps because face space is optimized for young faces. In Studies 4 and 5, I examined whether sensitivity to deviations from the norm is superior for young relative to older adult faces. I used normality/attractiveness judgments as a measure of this sensitivity; to examine whether biases were specific to norm-based coding, I asked participants to discriminate between the same faces. Both young and older adults were more accurate when tested with young relative to older faces—but only when judging normality. Like adults, 3- and 7-year-olds were more accurate in judging the attractiveness of young faces; however, unlike adults, this bias extended to the discrimination task. Thus by 3 years of age children are more sensitive to differences among young relative to older faces, suggesting that young children's perceptual system is more finely tuned for young than older adult faces. Collectively, the results of this dissertation help elucidate the development of category-specific norms and clarify the role of experience in shaping sensitivity to the dimensions of face space.