547 research outputs found
Matching Subsequences in Trees
Given two rooted, labeled trees and the tree path subsequence problem
is to determine which paths in are subsequences of which paths in . Here
a path begins at the root and ends at a leaf. In this paper we propose this
problem as a useful query primitive for XML data, and provide new algorithms
improving the previously best known time and space bounds.Comment: Minor correction of typos, et
Jos tämä on onnellisinta ja parasta mitä maailmasta löytyy, aika huonolta näyttää:löytyä-verbin polysemiaa
Tiivistelmä. Tutkin pro gradu -työssäni löytyä-verbin polysemiaa eli monimerkityksisyyttä korpusaineiston pohjalta. Kuulemani ohjeen mukaan löytyä-verbin käyttö merkityksessä ’olla olemassa’ olisi norminvastaista, minkä myös tutkimani sanakirjat ja kielenhuollon oppaat vahvistavat. Arkihavaintojeni pohjalta muodostan löytyä-verbille kolme merkitystyyppiä, jotka ovat (i) ’jotain etsitään aktiivisesti’, (ii) ’jotain havaitaan sattumalta’ ja (iii) ’jotain on olemassa’. Tutkimuksessani selvitän, voiko löytyä-verbille hahmottaa lisäksi muita merkityksiä, mikä on löytyä-verbin keskeisin merkitystyyppi, miten löytyä-verbiä käytetään puhekielisessä internetkeskustelussa ja normitetussa sanoma- ja aikakauslehtikielessä ja onko käyttö eri kielenkäyttökonteksteissa erilaista.
Aineistoni muodostuvat Kielipankin Korp-palvelussa saatavilla olevista korpuksista "1990- ja 2000-luvun suomalaisia aikakaus- ja sanomalehtiä" sekä "Suomi24 2001–2017". Ensiksi mainittu korpus sisältää nimensä mukaisesti suomalaisia sanoma- ja aikakauslehtiä 1990- ja 2000-luvuilta ja toinen korpus koostuu internetkeskustelupalsta Suomi24:n keskusteluista vuosilta 2001–2017. Kerään satunnaisotannalla molemmista korpuksista 170 esimerkkiä, jolloin koko aineistoni koostuu yhteensä 340 esimerkistä.
Tutkimukseni nojautuu teorialtaan kognitiivisen semantiikan tutkimustraditioon. Menetelmänä käytän korpuspohjaista tutkimusmetodia. Analyysini jakautuu kahteen alalukuun, joissa käsittelen erikseen sanoma- ja aikakauslehtiaineistoni ja keskustelupalsta-aineistoni. Jaan esimerkit kolmeen edellä esiteltyyn ryhmään intuitioni perusteella. Esitän jokaisesta ryhmästä tyyppiesimerkkejä ja kerron, millä perusteella teen luokittelua. Paikoitellen pohdin tarkemminkin esimerkkilauseiden semantiikkaa.
Ensimmäisen tutkimuskysymykseni mukaan selvitän, millaisia merkityksiä löytyä-verbille voi hahmottaa. Jo ennen analyysin aloittamista nimesin kolme ryhmää, jotka esittelin edellä. Niiden lisäksi analyysin aikana vastaan ei tullut esimerkkejä, jotka eivät olisi sopineet mihinkään kolmesta ryhmästä, sen sijaan joidenkin esimerkkien sijoittaminen yksiselitteisesti vain yhteen ryhmään osoittautui vaikeaksi. Siispä voin todeta oman aineistoni valossa, että verbille löytyä voidaan hahmottaa ainakin kolme eri merkitystä, jotka ovat (i) ’jotain etsitään aktiivisesti’, (ii) ’jotain havaitaan sattumalta’ ja (iii) ’jotain on olemassa’. Verbin löytyä keskeisin merkitystyyppi on molemmissa aineistoissa ’jotain etsitään aktiivisesti’. Sekä sanoma- ja aikakauslehtiaineistossa että keskustelupalsta-aineistossa noin puolet esimerkeistä sijoittui mainittuun ryhmään. Yksi huomattavimmista eroista löytyä-verbin käytössä internetkeskustelun ja aikakaus- ja sanomalehtikielen välillä on ryhmän (ii) ’jotain havaitaan sattumalta’ suurempi koko lehtiaineistossa keskustelupalsta-aineistoon verrattuna. Kaiken kaikkiaan verbin löytyä käyttö ei kuitenkaan ole merkittävästi erilaista eri aineistoissani.
Löytyä-verbiä tai sen polysemiaa ei ole tässä laajuudessa aiemmin tutkittu, ja siten tutkielmani tuokin esille uutta tietoa löytyä-verbistä todellisissa kielenkäyttötilanteissa ja tarkentaa ja täydentää sille annettuja sanakirjamerkityksiä. Aikaisemmin norminvastaisena pidetty käyttö eksistentiaalisessa merkityksessä on molemmissa aineistoissani vahvasti edustettuna, ja voi ollakin, että ohje vältettävästä käytöstä on väljentynyt nykyisissä kielenhuollon linjauksissa
Stabilization of Ge-rich defect complexes originating from E centers in Si1- xGex:P
Thermal evolution of vacancy complexes was studied in P-doped ([P]=10 exp 18 cm exp −3) proton irradiated Si1−xGex with Ge contents of 10%, 20%, and 30% in the range of 250–350 °C using positron annihilation spectroscopy. The radiation damage recovers in the course of anneals but the final state differs from that in as-grown samples indicating the presence of small Ge clusters in the samples, contrary to the initially random Ge distribution. The activation energy for the annealing process was estimated to be 1.4±0.3 eV and attributed to the dissociation energy of the vacancy-phosphorus-germanium (V-P-Ge) complex.Peer reviewe
Effects of intensified silviculture on timber production and its economic profitability in boreal Norway spruce and Scots pine stands under changing climatic conditions
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Effects of Initial Age Structure of Managed Norway Spruce Forest Area on Net Climate Impact of Using Forest Biomass for Energy
We investigated how the initial age structure of a managed, middle boreal (62A degrees N), Norway spruce-dominated (Picea abies L. Karst.) forest area affects the net climate impact of using forest biomass for energy. The model-based analysis used a gap-type forest ecosystem model linked to a life cycle assessment (LCA) tool. The net climate impact of energy biomass refers to the difference in annual net CO2 exchange between the biosystem using forest biomass (logging residues from final felling) and the fossil (reference) system using coal. In the simulations over the 80-year period, the alternative initial age structures of the forest areas were (i) skewed to the right (dominated by young stands), (ii) normally distributed (dominated by middle-aged stands), (iii) skewed to the left (dominated by mature stands), and (iv) evenly distributed (same share of different age classes). The effects of management on net climate impacts were studied using current recommendations as a baseline with a fixed rotation period of 80 years. In alternative management scenarios, the volume of the growing stock was maintained 20% higher over the rotation compared to the baseline, and/or nitrogen fertilization was used to enhance carbon sequestration. According to the results, the initial age structure of the forest area affected largely the net climate impact of using energy biomass over time. An initially right-skewed age structure produced the highest climate benefits over the 80-year simulation period, in contrast to the left-skewed age structure. Furthermore, management that enhanced carbon sequestration increased the potential of energy biomass to replace coal, reducing CO2 emissions and enhancing climate change mitigation.Peer reviewe
Renal Tumor Invasion Depth and Diameter are the Two Most Accurate Anatomical Features Regarding the Choice of Radical Versus Partial Nephrectomy
Background and Aims: To evaluate simple tumor characteristics (renal tumor diameter and parenchymal invasion depth) compared with more complex classifications, that is, Renal Tumor Invasion Index (RTII) and Preoperative Aspects and Dimensions Used for an Anatomical classification, in predicting the type of nephrectomy (radical vs partial) performed. Material and Methods: A total of 915 patients who had undergone either partial nephrectomy (n=388, 42%) or radical nephrectomy (n=527, 58%) were identified from the Helsinki University Hospital kidney tumor database between 1 January 2006 and 31 December 2014. Tumor maximum diameter and depth of invasion into the parenchyma were estimated from computed tomography or magnetic resonance imaging images and compared with Preoperative Aspects and Dimensions Used for an Anatomical and Renal Tumor Invasion Index. Logistic regression and receiver operating curves were used to compare the parameters at predicting the type of nephrectomy. Results and conclusion: All the anatomical variables of receiver operating curve/area under the curve analyses were significant predictors for the type of nephrectomy. Parenchymal invasion (area under the curve 0.91; 95% confidence interval, 0.89-0.93), RTII (area under the curve 0.91; 95% confidence interval, 0.89-0.93), and diameter (area under the curve 0.91; 95% confidence interval, 0.89-0.93) performed significantly better than Preoperative Aspects and Dimensions Used for an Anatomical classification (area under the curve 0.88; 95% confidence interval, 0.85-0.89). In multivariable analysis, invasion depth was the best predictor of nephrectomy type (percentage correct, 85.6%). Addition of one anatomic parameter into the model of non-anatomical cofactors improved the accuracy of the model significantly, but the addition of more parameters did not. Parenchymal invasion depth and tumor diameter are the most accurate anatomical features for predicting the nephrectomy type. All potential anatomical classification systems should be tested against these two simple characteristics.Peer reviewe
Differences in branch characteristics of Scots pine (Pinus sylvestris L.) genetic entries grown at different spacing
• We studied the differences in branch characteristics along the stems of six different
genetic entries of 20 year old Scots pines (Pinus sylvestris L.) grown at
different spacing (current stand density range 2000–4000 trees ha−1) in central
Finland. Furthermore, we studied the phenotypic correlations between yield, wood density
traits and branch characteristics. All the genetic entries had Kanerva pine (plus tree
S1101) as a father tree, whereas the mother tree represented Finnish plus trees from
southern, central and northern Finland.
• Spacing affected all yield traits, wood density and living branch characteristics such
as relative average branch diameter and relative cumulative branch area
(p < 0.05). As a comparison, genetic entry affected height,
while origin group (southern, central and northern ones) affected most of the studied
traits. Regardless of spacing, the northern origin had, on average, the largest stem
diameter and highest wood density, while the central one was the tallest one. Furthermore,
average branch diameter along the stem was affected by branch age, origin group and
spacing, while average branch angle was affected by branch age and genetic entry
(p < 0.05).
• In general the average branch size could be decreased especially in lower tree canopy
by denser spacing during the early phase of the rotation, but only at the expense of tree
growth. Correspondingly differences between origins are mainly related to their
differences in stem growth
Local and global behaviour of nonlinear equations with natural growth terms
This paper concerns a study of the pointwise behaviour of positive solutions
to certain quasi-linear elliptic equations with natural growth terms, under
minimal regularity assumptions on the underlying coefficients. Our primary
results consist of optimal pointwise estimates for positive solutions of such
equations in terms of two local Wolff's potentials.Comment: In memory of Professor Nigel Kalto
Removal of proteinase K resistant alpha Syn species does not correlate with cell survival in a virus vector-based Parkinson's disease mouse model
Parkinson's disease (PD) is characterized by degeneration of nigrostriatal dopaminergic neurons and accumu-lation of alpha-synuclein (alpha Syn) as Lewy bodies. Currently, there is no disease-modifying therapy available for PD. We have shown that a small molecular inhibitor for prolyl oligopeptidase (PREP), KYP-2047, relieves alpha Syn-induced toxicity in various PD models by inducing autophagy and preventing alpha Syn aggregation. In this study, we wanted to study the effects of PREP inhibition on different alpha Syn species by using cell culture and in vivo models.We used Neuro2A cells with transient alpha Syn overexpression and oxidative stress or proteasomal inhibition -induced alpha Syn aggregation to assess the effect of KYP-2047 on soluble alpha Syn oligomers and on cell viability. Here, the levels of soluble alpha Syn were measured by using ELISA, and the impact of KYP-2047 was compared to anle138b, nilotinib and deferiprone. To evaluate the effect of KYP-2047 on alpha Syn fibrillization in vivo, we used unilateral nigral AAV1/2-A53T-alpha Syn mouse model, where the KYP-2047 treatment was initiated two-or four -weeks post injection.KYP-2047 and anle138b protected cells from alpha Syn toxicity but interestingly, KYP-2047 did not reduce soluble alpha Syn oligomers. In AAV-A53T-alpha Syn mouse model, KYP-2047 reduced significantly proteinase K-resistant alpha Syn oligomers and oxidative damage related to alpha Syn aggregation. However, the KYP-2047 treatment that was initiated at the time of symptom onset, failed to protect the nigrostriatal dopaminergic neurons. Our results emphasize the importance of whole alpha Syn aggregation process in the pathology of PD and raise an important question about the forms of alpha Syn that are reasonable targets for PD drug therapy.Peer reviewe
Riesz and Wolff potentials and elliptic equations in variable exponent weak Lebesgue spaces
We prove optimal integrability results for solutions of the p(x)-Laplace equation in the scale of (weak) Lebesgue spaces.
To obtain this, we show that variable exponent Riesz and Wolff potentials map L1 to variable exponent weak Lebesgue spaces
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