Legislative Constitutional Interpretation

The standard method of estimating the value of travel time variability for use in policy appraisal is to estimate the parameters of a reduced-form utility function, where some measure of travel time variability (such as the standard deviation) is included. A problem with this approach is that the obtained valuation will in general depend on the standardized travel time distribution, and hence cannot be transferred from one context to another. A recently suggested remedy for this problem has been to estimate a scheduling model, which in theory is transferrable, and use the implied reduced-form to derive valuations for use in appraisal. In this paper we estimate both a scheduling model and the implied reduced-form model, using stated choice data. The valuation of travel time variability implied by the scheduling model turns out to be substantially smaller than what is obtained from a reduced-form model estimated on the same sample. The results suggest that the scheduling model does not capture all of the disutility arising from travel time variability. Hence, although it can be shown that scheduling and reduced-form models are theoretically equivalent, that hypothesized equivalence is not reflected in the empirical evidence. We speculate that the derivation of reduced-form models from an underlying scheduling model omits two essential features: first, the notion of an exogenously fixed “preferred arrival time” neglects the fact that most activities can be rescheduled given full information about the travel times in advance, and second, disutility may be derived from uncertainty as such, in the form of anxiety, decisions costs or costs for having contingency plans. We also report our estimates of the valuation of travel time variability for public transit trips, for use in applied appraisal

Revisiting remyelination: Towards a consensus on the regeneration of CNS myelin.

The biology of CNS remyelination has attracted considerable interest in recent years because of its translational potential to yield regenerative therapies for the treatment of chronic and progressive demyelinating diseases such as multiple sclerosis (MS). Critical to devising myelin regenerative therapies is a detailed understanding of how remyelination occurs. The accepted dogma, based on animal studies, has been that the myelin sheaths of remyelination are made by oligodendrocytes newly generated from adult oligodendrocyte progenitor cells in a classical regenerative process of progenitor migration, proliferation and differentiation. However, recent human and a growing number of animal studies have revealed a second mode of remyelination in which mature oligodendrocytes surviving within an area of demyelination are able to regenerate new myelin sheaths. This discovery, while opening up new opportunities for therapeutic remyelination, has also raised the question of whether there are fundamental differences in myelin regeneration between humans and some of the species in which experimental remyelination studies are conducted. Here we review how this second mode of remyelination can be integrated into a wider and revised framework for understanding remyelination in which apparent species differences can be reconciled but that also raises important questions for future research.We thank Sarah Neely, University of Edinburgh, for generating the schematic figure. Work in the Franklin lab is supported by UK Multiple Sclerosis Society, the Adelson Medical ResearchFoundation, and a core support grant from the Wellcome and MRC to the Wellcome-MedicalResearch Council Cambridge Stem Cell Institute. , in the Frisen lab by Swedish Research Council, the Swedish Cancer Society, the Swedish Foundation for Strategic Research, Knutoch Alice Wallenbergs Stiftelse and the ERC, and in the Lyons lab by the Wellcome Trust, the UK Multiple Sclerosis Society, the MRC, and Biogen

Revision and complication rates in 654 Exeter total hip replacements, with a maximum follow-up of 20 years.

Background: Iceland's geographical isolation with a stable and small population gives a rare opportunity for follow-up studies of medical interventions. Total hip replacements (THR) have been done at FSA Central Hospital in Akureyri, Iceland since 1982 with the Exeter hip implant being in use from the beginning. Methods: Hospital records for all patients operated on with THR between 1982 and the end of 1999 were reviewed and the patients were followed until the end of 2001. Information was gathered regarding the indication for primary surgery, the reason for revision if needed, as well as that of any complications. Survival statistics were used to calculate the cumulative revision rate. Results: The mean age at primary THR was 68.4 years for males and 68.8 years for females. 654 primary THRs were done; of which 571 (87 %) were due to osteoarthritis. 37 of the primary arthroplasties had been revised before the end of year 2001. Conclusion: We have in this unique 2-20 year study of 654 THRs with no loss to follow-up for the patients, found revision rates that conform with the large Swedish THR registry. Complication rates in general are in agreement with that reported for other comparable patient groups, while infection rates appear lower

Estimating forest structure in a tropical forest using field measurements, a synthetic model and discrete return lidar data

Tropical forests are huge reservoirs of terrestrial carbon and are experiencing rapid degradation and deforestation. Understanding forest structure proves vital in accurately estimating both forest biomass and also the natural disturbances and remote sensing is an essential method for quantification of forest properties and structure in the tropics. Our objective is to examine canopy vegetation profiles formulated from discrete return LIght Detection And Ranging (lidar) data and examine their usefulness in estimating forest structural parameters measured during a field campaign. We developed a modeling procedure that utilized hypothetical stand characteristics to examine lidar profiles. In essence, this is a simple method to further enhance shape characteristics from the lidar profile. In this paper we report the results comparing field data collected at La Selva, Costa Rica (10° 26′ N, 83° 59′ W) and forest structure and parameters calculated from vegetation height profiles and forest structural modeling. We developed multiple regression models for each measured forest biometric property using forward stepwise variable selection that used Bayesian information criteria (BIC) as selection criteria. Among measures of forest structure, ranging from tree lateral density, diameter at breast height, and crown geometry, we found strong relationships with lidar canopy vegetation profile parameters. Metrics developed from lidar that were indicators of height of canopy were not significant in estimating plot biomass (p-value = 0.31, r2 = 0.17), but parameters from our synthetic forest model were found to be significant for estimating many of the forest structural properties, such as mean trunk diameter (p-value = 0.004, r2 = 0.51) and tree density (p-value = 0.002, r2 = 0.43). We were also able to develop a significant model relating lidar profiles to basal area (p-value = 0.003, r2 = 0.43). Use of the full lidar profile provided additional avenues for the prediction of field based forest measure parameters. Our synthetic canopy model provides a novel method for examining lidar metrics by developing a look-up table of profiles that determine profile shape, depth, and height. We suggest that the use of metrics indicating canopy height derived from lidar are limited in understanding biomass in a forest with little variation across the landscape and that there are many parameters that may be gleaned by lidar data that inform on forest biometric properties

SIKAP PENERBIT CETAK DI KOTA SURABAYA DALAM PELAKSANAAN KEWAJIBAN SEBAGAI WAJIB SIMPAN KARYA DITINJAU BERDASARKAN DIMENSINYA

Sikap adalah bentuk evaluasi atau reaksi perasaan seseorang terhadap suatu obyek yang dapat berbentuk perasaan mendukung atau memihak (favorable), maupun perasaan tidak mendukung atau tidak memihak (unfavorable). Terdapat tiga dimensi sikap,yakni dimensi kognitif, dimensi afektif dan dimensi konatif. Kewajiban penerbit adalah menyerahkan sample karya tiap kali mengeluarkan terbitan terbaru sejumlah 2 buah kepada Perpustakaan Nasional dan 1 buah kepada Perpustakaan Daerah. Penelitian ini berfokus pada dimensi sikap penerbit cetak di Kota Surabaya yang bertujuan untuk mengetahui bagaimana sikap pimpinan tiap penerbit tersebut, apakah mendukung atau tidak mendukung kewajiban tersebut. Penelitian ini menggunakan metode kuantitatif deskriptif. Penelitian ini menggunakan teknik interview,penyebaran kuesioner dan observasi kepada responden untuk mendapatkan data. Hasil dari penelitian ini adalah pimpinan tiap penerbit cetak di Kota Surabaya mendukung kewajiban penyerah-simpanan sample karya berdasarkan dimensi kognitif, dimensi afektif dan dimensi konatif

Revision and complication rates in 654 Exeter total hip replacements, with a maximum follow-up of 20 years.

To access full text version of this article. Please click on the hyperlink "View/open" at the bottom of this pageBACKGROUND: Iceland's geographical isolation with a stable and small population gives a rare opportunity for follow-up studies of medical interventions. Total hip replacements (THR) have been done at FSA Central Hospital in Akureyri, Iceland since 1982 with the Exeter hip implant being in use from the beginning. METHODS: Hospital records for all patients operated on with THR between 1982 and the end of 1999 were reviewed and the patients were followed until the end of 2001. Information was gathered regarding the indication for primary surgery, the reason for revision if needed, as well as that of any complications. Survival statistics were used to calculate the cumulative revision rate. RESULTS: The mean age at primary THR was 68.4 years for males and 68.8 years for females. 654 primary THRs were done; of which 571 (87 %) were due to osteoarthritis. 37 of the primary arthroplasties had been revised before the end of year 2001. CONCLUSION: We have in this unique 2-20 year study of 654 THRs with no loss to follow-up for the patients, found revision rates that conform with the large Swedish THR registry. Complication rates in general are in agreement with that reported for other comparable patient groups, while infection rates appear lower

Biodiversity, productivity, and the spatial insurance hypothesis revisited

Accelerating rates of biodiversity loss have led ecologists to explore the effects of species richness on ecosystem functioning and the flow of ecosystem services. One explanation of the relationship between biodiversity and ecosystem functioning lies in the spatial insurance hypothesis, which centers on the idea that productivity and stability increase with biodiversity in a temporally varying, spatially heterogeneous environment. However, there has been little work on the impact of dispersal where environmental risk are more or less spatially correlated, or where dispersal rates are variable. In this paper, we extend the original Loreau model to consider stochastic temporal variation in resource availability, which we refer to as "environmental risk", and heterogeneity in species dispersal rates. We find that asynchronies across communities and species provide community-level stabilizing effects on productivity, despite varying levels of species richness. Although intermediate dispersal rates play a role in mitigating risk, they are less effective in insuring productivity against global (metacommunity-level) than local (individual community-level) risks. These results are particularly interesting given the emergence of global sources of risk such as climate change or the closer integration of world markets. Our results offer deeper insights into the Loreau model and new perspectives on the effectiveness of spatial insurance in the face of environmental risks

The impact of land use effects in infrastructure appraisal

When benefits of proposed infrastructure investments are forecasted, residential location is usually treated as fixed, since very few operational transport models are able to forecast residential relocation. It has been argued that this may constitute a source of serious error or bias when evaluating and comparing the benefits of proposed infrastructure investments. We use a stylized simulation model of a metropolitan region to compare calculated benefits for a large number of infrastructure investments with and without taking changes in residential location into account. In particular, we explore the changes in project selection when assembling an optimal project portfolio under a budget constraint. The simulation model includes endogenous land prices and demand for residential land, heterogeneous preferences and wage offers across residents, and spillover mechanisms which affect wage rates in zones. The model is calibrated to generate realistic travel patterns and demand elasticities. Our results indicate that ignoring residential relocation has a small but appreciable effect on the selected project portfolio, but only a very small effect on achieved total benefits

Floresta Ombrófila Densa Altomontana: aspectos florísticos e estruturais de diferentes trechos na Serra do Mar, PR.

The floristic and the structure of the Upper Montane Rain Forest, on five different mountains, along Serra do Mar, PR, were evaluated. Primary fragments, always above 1.250 m above sea level, were measured, with 10 rectangular samples (5 x 10m) (GBH > 10 cm) for each site. There were registered 55 species (36 gen., 24 fam.). Including other author’s data, it was possible to reveal that Ilex microdonta is the most important species, followed by Drimys brasiliensis, Ocotea catharinensis, Blepharocalyx salicifolius and Gordonia fruticosa. It was observed the high arborous density, with more than 4.490 trees per hectare, which configures a single stratum, and medium height of 4 m. On cluster analysis the best results were obtained by using the Importance Value. The minor stand similarity was registered among the sites on “morro do Araçatuba” (1.610 m) and “morro do Vigia” (1.280 m), indicating that the altitude factor has a powerful influence on this aspect. Although the Jaccard´s index for all the sites revealed that despite of the structure significant differences, in relation to the floristic all of these were considered similar.Foram avaliadas a florística e a estrutura da Floresta Ombrófila Densa Altomontana, em cinco diferentes montanhas, ao longo da Serra do Mar, PR. Trechos primários, sempre acima dos 1.250 m, foram mensurados, com dez parcelas retangulares (5x10 m), em cada local. Foram registradas 55 espécies arbóreas, 36 gêneros e 24 famílias. Incluíndo dados de outros autores, foi possível revelar que Ilex microdonta é a espécie mais importante, seguida por Drimys brasiliensis, Ocotea catharinensis, Blepharocalyx salicifolius e Gordonia fruticosa. Constatou-se a elevada densidade arbórea, até 4.490 árvores por hectare (PAP > 10 cm), formando um estrato único, com altura média de 4 m. Na análise de agrupamentos, os melhores resultados foram obtidos adotando-se a variável Valor de Importância. A menor similaridade estrutural foi registrada entre os trechos dos morros Araçatuba (1.610 m s.n.m.) e Vigia (1.280 m s.n.m.), indicando que o fator altitude exerce grande influência nesse aspecto. Contudo, verificou-se, com base no índice de Jaccard, que, floristicamente, todos os trechos são similares, embora ocorram diferenças estruturais importantes entre eles