5 resultados para 289
em Helda - Digital Repository of University of Helsinki
Resumo:
Tutkimuksen tavoitteet Tutkimuksen teoreettinen osa esittelee yhteiskunnallisten hankkeiden arvottamiseen liittyvää koti- ja ulkomaista kirjallisuutta. Empiirinen osa tutkii Savonlinnasta poimitun metsätilaotoksen avulla maiseman- ja luonnonhoidon aiheuttamia taloudellisia vaikutuksia tilojen metsänomistajille sekä vertaa näitä tuloksia haastattelututkimuksesta saatuihin vastauksiin maksuhalukkuudesta monimuotoisuuden hyväksi. Lähdeaineisto Metsämaiseman- ja luonnonhoidon aiheuttamia taloudellisia vaikutuksia tutkittaessa case-aineistona käytettiin keskeisen Saimaan Pihlajaveden saaristoalueen 24 tilaa, joiden omistajat olivat tilanneet Etelä-Savon metsäkeskukselta uudentyyppisen maiseman- ja luonnonhoidon arvot huomioivan metsäsuunnitelman. Samalla aineistolla suoritettiin myös metsänomistajien haastattelu, jonka avulla selvitettiin metsänomistajien maksuhalukkuutta monimuotoisuudesta ja maisemamansuojelusta. Lisäksi kysyttiin mielipiteitä nykyisistä metsänhoitosuosituksista ja alueelle kaavailluista luonnonsuojeluhankkeista. Aineiston käsittely Taloudellisia vaikutuksia tutkittaessa maisema- ja luontoarvoja korostavaa metsäsuunnitelmalaskelmaa verrattiin maksimaaliseen puuntuotantoon tähtäävään metsäsuunnitelmaan. Näiden kahden vaihtoehtoisten laskelman välinen erotus tulkittiin monimuotoisuuden turvaamisen metsälötason puuntuotannolliseksi vaikutukseksi. Vastaavasti haastatteluosuudessa metsänomistajilta kysyttiin, kuinka paljon he olisivat valmiita luopumaan metsätuloistaan monimuotoisuuden edistämiseksi. Maksuhalukkuutta tutkittaessa käytettiin contingent valuation -menetelmää. Tulokset Siirtyminen ns. perinteisestä metsänkäsittelystä maiseman- ja luonnonhoidon huomioivaan metsänkäsittelyyn pienentää metsästä saatavia nettotuloja ensimmäisen kymmenvuotiskauden aikana 36 % eli 289 mk/ha vuosittain. Vastaavasti metsänomistajien maksuhalukkuus monimutoisuuden edistämisestä oli 5,3 % metsätuloista, joka on rahassa 18 mk/ha vuosittain. Nettotulojen merkittävä pieneneminen selittyy kohteen arvokkailla maisema-arvoilla ja ekologisten elinympäristöjen runsaalla lukumäärällä. Tulosten tilastollista luotettavuutta ei otoksen pienuuden vuoksi voitu tarkastella. Avainsanat: metsämaiseman- ja luonnonhoito, metsätulot, maksuhalukkuus, monimuotoisuus, Pihlajaveden saaristo
Resumo:
The greatest effect on reducing mortality in breast cancer comes from the detection and treatment of invasive cancer when it is as small as possible. Although mammography screening is known to be effective, observer errors are frequent and false-negative cancers can be found in retrospective studies of prior mammograms. In the year 2001, 67 women with 69 surgically proven cancers detected at screening in the Mammography Centre of Helsinki University Hospital had previous mammograms as well. These mammograms were analyzed by an experienced screening radiologist, who found that 36 lesions were already visible in previous screening rounds. CAD (Second Look v. 4.01) detected 23 of these missed lesions. Eight readers with different kinds of experience with mammography screening read the films of 200 women with and without CAD. These films included 35 of those missed lesions and 16 screen-detected cancers. CAD sensitivity was 70.6% and specificity 15.8%. Use of CAD lengthened the mean time spent for readings but did not significantly affect readers sensitivities or specificities. Therefore the use of applied version of CAD (Second Look v. 4.01) is questionable. Because none of those eight readers found exactly same cancers, two reading methods were compared: summarized independent reading (at least a single cancer-positive opinion within the group considered decisive) and conference consensus reading (the cancer-positive opinion of the reader majority was considered decisive). The greatest sensitivity of 74.5% was achieved when the independent readings of 4 best-performing readers were summarized. Overall the summarized independent readings were more sensitive than conference consensus readings (64.7% vs. 43.1%) while there was far less difference in mean specificities (92.4% vs. 97.7%). After detecting suspicious lesion, the radiologist has to decide what is the most accurate, fast, and cost-effective means of further work-up. The feasibility of FNAC and CNB in the diagnosis of breast lesions was compared in non-randomised, retrospective study of 580 (503 malignant) breast lesions of 572 patients. The absolute sensitivity for CNB was better than for FNAC, 96% (206/214) vs. 67% (194/289) (p < 0.0001). An additional needle biopsy or surgical biopsy was performed for 93 and 62 patients with FNAC, but for only 2 and 33 patients with CNB. The frequent need of supplement biopsies and unnecessary axillary operations due to false-positive findings made FNAC (294 ) more expensive than CNB (223 ), and because the advantage of quick analysis vanishes during the overall diagnostic and referral process, it is recommendable to use CNB as initial biopsy method.
Resumo:
Background: The incidence of all forms of congenital heart defects is 0.75%. For patients with congenital heart defects, life-expectancy has improved with new treatment modalities. Structural heart defects may require surgical or catheter treatment which may be corrective or palliative. Even those with corrective therapy need regular follow-up due to residual lesions, late sequelae, and possible complications after interventions. Aims: The aim of this thesis was to evaluate cardiac function before and after treatment for volume overload of the right ventricle (RV) caused by atrial septal defect (ASD), volume overload of the left ventricle (LV) caused by patent ductus arteriosus (PDA), and pressure overload of the LV caused by coarctation of the aorta (CoA), and to evaluate cardiac function in patients with Mulibrey nanism. Methods: In Study I, of the 24 children with ASD, 7 underwent surgical correction and 17 percutaneous occlusion of ASD. Study II had 33 patients with PDA undergoing percutaneous occlusion. In Study III, 28 patients with CoA underwent either surgical correction or percutaneous balloon dilatation of CoA. Study IV comprised 26 children with Mulibrey nanism. A total of 76 healthy voluntary children were examined as a control group. In each study, controls were matched to patients. All patients and controls underwent clinical cardiovascular examinations, two-dimensional (2D) and three-dimensional (3D) echocardiographic examinations, and blood sampling for measurement of natriuretic peptides prior to the intervention and twice or three times thereafter. Control children were examined once by 2D and 3D echocardiography. M-mode echocardiography was performed from the parasternal long axis view directed by 2D echocardiography. The left atrium-to-aorta (LA/Ao) ratio was calculated as an index of LA size. The end-diastolic and end-systolic dimensions of LV as well as the end-diastolic thicknesses of the interventricular septum and LV posterior wall were measured. LV volumes, and the fractional shortening (FS) and ejection fraction (EF) as indices of contractility were then calculated, and the z scores of LV dimensions determined. Diastolic function of LV was estimated from the mitral inflow signal obtained by Doppler echocardiography. In three-dimensional echocardiography, time-volume curves were used to determine end-diastolic and end-systolic volumes, stroke volume, and EF. Diastolic and systolic function of LV was estimated from the calculated first derivatives of these curves. Results: (I): In all children with ASD, during the one-year follow-up, the z score of the RV end-diastolic diameter decreased and that of LV increased. However, dilatation of RV did not resolve entirely during the follow-up in either treatment group. In addition, the size of LV increased more slowly in the surgical subgroup but reached control levels in both groups. Concentrations of natriuretic peptides in patients treated percutaneously increased during the first month after ASD closure and normalized thereafter, but in patients treated surgically, they remained higher than in controls. (II): In the PDA group, at baseline, the end-diastolic diameter of LV measured over 2SD in 5 of 33 patients. The median N-terminal pro-brain natriuretic peptide (proBNP) concentration before closure measured 72 ng/l in the control group and 141 ng/l in the PDA group (P = 0.001) and 6 months after closure measured 78.5 ng/l (P = NS). Patients differed from control subjects in indices of LV diastolic and systolic function at baseline, but by the end of follow-up, all these differences had disappeared. Even in the subgroup of patients with normal-sized LV at baseline, the LV end-diastolic volume decreased significantly during follow-up. (III): Before repair, the size and wall thickness of LV were higher in patients with CoA than in controls. Systolic blood pressure measured a median 123 mm Hg in patients before repair (P < 0.001) and 103 mm Hg one year thereafter, and 101 mm Hg in controls. The diameter of the coarctation segment measured a median 3.0 mm at baseline, and 7.9 at the 12-month (P = 0.006) follow-up. Thicknesses of the interventricular septum and posterior wall of the LV decreased after repair but increased to the initial level one year thereafter. The velocity time integrals of mitral inflow increased, but no changes were evident in LV dimensions or contractility. During follow-up, serum levels of natriuretic peptides decreased correlating with diastolic and systolic indices of LV function in 2D and 3D echocardiography. (IV): In 2D echocardiography, the interventricular septum and LV posterior wall were thicker, and velocity time integrals of mitral inflow shorter in patients with Mulibrey nanism than in controls. In 3D echocardiography, LV end-diastolic volume measured a median 51.9 (range 33.3 to 73.4) ml/m² in patients and 59.7 (range 37.6 to 87.6) ml/m² in controls (P = 0.040), and serum levels of ANPN and proBNP a median 0.54 (range 0.04 to 4.7) nmol/l and 289 (range 18 to 9170) ng/l, in patients and 0.28 (range 0.09 to 0.72) nmol/l (P < 0.001) and 54 (range 26 to 139) ng/l (P < 0.001) in controls. They correlated with several indices of diastolic LV function. Conclusions (I): During the one-year follow-up after the ASD closure, RV size decreased but did not normalize in all patients. The size of the LV normalized after ASD closure but the increase in LV size was slower in patients treated surgically than in those treated with the percutaneous technique. Serum levels of ANPN and proBNP were elevated prior to ASD closure but decreased thereafter to control levels in patients treated with the percutaneous technique but not in those treated surgically. (II): Changes in LV volume and function caused by PDA disappeared by 6 months after percutaneous closure. Even the children with normal-sized LV benefited from the procedure. (III): After repair of CoA, the RV size and the velocity time integrals of mitral inflow increased, and serum levels of natriuretic peptides decreased. Patients need close follow-up, despite cessation of LV pressure overload, since LV hypertrophy persisted even in normotensive patients with normal growth of the coarctation segment. (IV): In children with Mulibrey nanism, the LV wall was hypertrophied, with myocardial restriction and impairment of LV function. Significant correlations appeared between indices of LV function, size of the left atrium, and levels of natriuretic peptides, indicating that measurement of serum levels of natriuretic peptides can be used in the clinical follow-up of this patient group despite its dependence on loading conditions.
Resumo:
This article reports on a cross-sectional case study of a large construction project in which Electronic document management (EDM) was used. Attitudes towards EDM from the perspective of individual end users were investigated. Responses from a survey were combined with data from system usage log files to obtain an overview of attitudes prevalent in different user segments of the total population of 334 users. The survey was followed by semi-structured interviews with representative users. A strong majority of users from all segments of the project group considered EDM as a valuable aid in their work processes, despite certain functional limitations of the system used and the complexity of the information mass. Based on the study a model describing the key factors affecting end user EDM adoption is proposed. The model draws on insight from earlier studies of EDM enabled projects and theoretical frameworks on technology acceptance and success of information systems, as well as the insights gained from the case study.
Resumo:
Acquisitions are a central component of corporate strategy. They contribute to competitive advantage by offering possibilities for both cost reductions and for revenue enhancements. However, many acquisition benefits cannot be realized without a successful integration of the acquiring and the acquired firms. Previous research shows that national and organizational culture can play a major role in determining the integration outcomes. Therefore, the overall aim of the thesis is to map out and illustrate the impact mechanisms of cultural factors in post-acquisition integration in order to explain the cultural aspects of acquisitions. This study has three main contributions. First, the study shows that international and domestic acquisitions differ concerning both strategic and cultural fit. Second, the findings highlight the importance of acculturation and cultural integration in determining post-acquisition outcomes. Finally, the study uncovers several impact mechanisms that shed light to the contradictory results related to cultural differences in previous research.