504 research outputs found
Time Varying Market Integration and Expected Rteurns in Emerging Markets
We use a simple model in which the expected returns in emerging markets depend on their systematic risk as measured by their beta relative to the world portfolio as well as on the level of integration in that market.The level of integration is a time-varying variable that depends on the market value of the assets that can be held by domestic investors only versus the market value of the assets that can be traded freely.Our empirical analysis for 30 emerging markets shows that there are strong effects of the level of integration or segmentation on the expected returns in emerging markets.The expected returns depend both on the level of segmentation of the emerging market itself and on the regional segmentation level.We also find that there is significant time-variation in the betas relative to the world portfolio because of the level of segmentation.For the composite index of the emerging markets we find an annual increase in beta of 0.09 due to decreased segmentation of the emerging markets in our sample period.In terms of expected returns the total effect on the composite index translates into an average decrease of 4.5 percent per annum.As predicted by our model, the noninvestable assets are more sensitive to the local and less to the regional level of segmentation than the investable assets.These conclusions do not change when using additional control variables. We do not find a clear pattern between volatility and segmentation, however.return on investment;economic integration;international financial markets;capital markets
An empirical analysis of the hedging effectiveness of currency futures
Existing research on the hedging effectiveness of currency futures assumes that futures positions are continuously adjusted. This is an unrealistic assumption in practice. In this paper we study the hedging effectiveness for futures positions which are not adjusted during the hedge period. For this purpose an out-of-sample approach is used. Three models are used to determine hedge ratios and hedging effectiveness. These are the minimum-variance model of Ederington (1979), the "-t model of Fishburn (1977), which is a model in which the disutility of a loss is minimized, and the Sharpe-ratio model of Howard and D'Antonio (1984, 1987). For the minimum-variance model and the "-t model it is found that the naively hedged positions yield a higher effectiveness than the unadjusted model-based hedged positions. For the Sharpe-ratio model it is found that both naively and model-based hedged positions lead to a lower hedging effectiveness than unhedged positionsCurrency;Hedging;Econometric Models;Futures;econometrics
Impactmeting : Greenportregio Boskoop als collectief agrarisch kennis- en innovatienetwerk
In het EFRO-project (Europees Fonds voor Regionale Ontwikkeling) Kennis & Innovatie Impuls Greenportregio Boskoop wordt gewerkt aan het realiseren van een efficiënt, doeltreffend en samenhangend kennis- en innovatiesysteem voor het stimuleren van kennisverbreding en kennisverspreiding en voor het stimuleren van innovatie in de boomteeltsector. Het project draagt bij aan de versterking van de Greenportregio Boskoop als bloeiend centrum voor kennis en innovatie. De stichting Greenport Boskoop is penvoerder van het EFRO-project. Om de effecten van de diverse kennis- en innovatieactiviteiten in de regio in beeld te kunnen brengen is als cofinancierend onderdeel van het EFRO-project binnen het T&U-onderzoeksthema (tuinbouw en uitgangsmaterialen) Methodieken Kennisoverdracht een impactmeting uitgevoerd. Dit thema wordt in opdracht van de topsector T&U uitgevoerd. De impactmeting is gebaseerd op 11 tafelinterviews en 5 telefonische interviews met verschillende groepen belanghebbenden. De impactmeting heeft geresulteerd in een overzicht van bereikte resultaten, verbeterpunten en suggesties voor toekomstige projecten om verdere ontwikkeling te realiseren. Kennis & Innovatie Impuls is een opbrengst van de Greenport Boskoop en is een van de vele activiteiten binnen deze Greenport. Voor de geïnterviewden was het soms lastig om een onderscheid te maken tussen de impact van het project Kennis & Innovatie Impuls en de impact van de Greenport Boskoop in generieke zin. Anderzijds blijkt daaruit ook de interactie tussen beiden. De impactmeting heeft laten zien dat vrijwel alle doelen uit het EFRO-werkplan gerealiseerd zijn, met uitzondering van de doelstelling om een vergrote uitstroom van gekwalificeerde vakkrachten uit het regulier beroepsonderwijs te krijgen voor de boomkwekerij in de regio. Uit de interviews blijkt dat dit vooral te maken had met de economische crisis waardoor er sprake was van een overschot aan arbeidskrachten in plaats van het in 2009 voorziene tekort
Eindrapportage: Verkenning en ontwikkeling innovatiethema Agrologistiek Greenport Boskoop
Wageningen UR heeft onder de vlag van het onderzoeksthema T&U Kennis, innovatie en HCA (BO-09) samen met de Stichting Greenport Boskoop een verkenning uitgevoerd naar de ontwikkeling van het innovatiethema Agrologistiek (als pilot) voor het kennis- en innovatiesysteem van de Greenport Boskoop
Suspended sediment fluxes in an Indonesian river draining a rainforested basin subject to land cover change
Forest clearing for reasons of timber production, open pit mining and the establishment of oil palm plantations generally results in excessively high sediment loads in the tropics. The increasing sediment fluxes pose a threat to coastal marine ecosystems such as coral reefs. This study presents observations of suspended sediment fluxes in the Berau river (Indonesia), which debouches into a coastal ocean that can be considered the preeminent center of coral diversity. The Berau is an example of a small river draining a mountainous, relatively pristine basin that receives abundant rainfall. Flow velocity was measured over a large part of the river width at a station under the influence of tides, using a Horizontal Acoustic Doppler Current Profiler (HADCP). Surrogate measurements of suspended sediment concentration were taken with an Optical Backscatter Sensor (OBS). Tidally averaged suspended sediment concentration increases with river discharge, implying that the tidally averaged suspended sediment flux increases non-linearly with river discharge. Averaged over the 6.5 weeks observations covered by the benchmark survey, the tidally averaged suspended sediment flux was estimated at 2 Mt y-1. Considering the wet conditions during the observation period, this figure may be considered as an upper limit of the yearly averaged flux. This flux is significantly smaller than what could have been expected from the characteristics of the catchment. The consequences of ongoing clearing of rainforest were explored using a plot scale erosion model. When rainforest, which still covered 50–60 % of the basin in 2007, is converted to production land, soil loss is expected to increase with a factor between 10 and 100. If this soil loss is transported seaward as suspended sediment, the increase in suspended sediment flux in the Berau river would impose a severe sediment stress on the global hotspot of coral reef diversity. The impact of land cover changes will largely depend on the degree in which the Berau estuary acts as a sediment tra
Tussenrapportage Kennis- en innovatiesystemen in de Greenportregio's : eerste resultaten monitoringstudie
In deze tussenrapportage staan de tussentijdse (eerste) resultaten beschreven van de monitoringstudie naar de totstandkoming van regionale kennis- en innovatiesysteem binnen de zeven Greenportregio’s: Noord- Holland Noord, Aalsmeer, Duin- en Bollenstreek, Westland-Oostland, Betuwse Bloem, Venlo en Boskoop. Deze rapportage moet dan ook worden gelezen als een tussenproduct, als work in progress, van de respectievelijke regioprojecten die onder het onderzoeksthema T&U Methodieken Kennisoverdracht zijn uitgevoerd. Hierin zijn de resultaten van de eerste monitoringsfase beschreven. Deze rapportage en de volgende tussenproducten van de onderzoeksfasen, zullen uiteindelijk worden bewerkt tot het beoogde formele eindrapport
Plant programmed cell death, ethylene and flower senescence
Programmed cell death (PCD) applies to cell death that is part of the normal life of multicellular organisms. PCD is found throughout the animal and plant kingdoms; it is an active process in which a cell suicide pathway is activated resulting in controlled disassembly of the cell. Most cases of PCD described in animal systems take the form of apoptosis, a cell death process characterised by specific features such as cell shrinkage, blebbing of the plasma membrane, condensation and fragmentation of the nucleus and internucleosomal cleavage of DNA. The final stage of apoptosis is the fragmentation of the cell into cellular debris-containing vesicles called `apoptotic bodies` that are being phagocytosed by other cells. A specific class of cell death- associated cystein proteases (caspases) has been identified. Generally, apoptotic cell death involves a sequence of caspase activation events in which initiator caspases activate down-stream executioner caspases that process a variety of target proteins eventually leading to the apoptotic phenotype. The occurrence of hallmarks of animal apoptosis was studied in tomato cells treated with the anticancer drug and inducer of apoptosis, camptothecin (cpt). It was shown that cpt-induced cell death is accompanied by nuclear condensation, the appearance of TUNEL-positive nuclei, DNA laddering and formation of DNA-containing (apoptotic) bodies and was greatly inhibited by inhibitors of animal caspases. Together the results indicate that cpt induced a cell death pathway with similarities to caspase-mediated (apoptotic) cell death in animal systems. We used cpt-treated cells to study the possible involvement of ethylene in cell death. Treatment of the cells with relatively high concentrations of ethylene did not have any effect on viability of the cells. However, when ethylene was applied in combination with cpt, a significant increase in cell death was observed as compared to cpt treatment alone. Experiments with inhibitors of ethylene production or ethylene action showed that ethylene is an essential factor mediating cpt-induced cell death. Flower senescence is accompanied by rapid death of large numbers of cells. In situ DNA degradation was studied in gypsophila petals using TUNEL. We showed that TUNEL positive nuclei appear well before the onset of the increase in ethylene production and visible signs of senescence. The role of PCD in flower senescence is discussed
Fauna en terreinkenmerken van bos; een studie naar de relatie tussen terreinkenmerken en de geschiktheid van bos als habitat voor een aantal diersoorten
In dit rapport wordt een methode beschreven waarmee de geschiktheid van het bos als habitat voor verschillende diersoorten kan worden bepaald op basis van de terreinkenmerken van het bos. De methode is gebaseerd op HSI-modellen. Er zijn 10 terreinkenmerken gebruikt om de habitatgeschiktheid te bepalen. Naast het onderdeel dat de habitatgeschiktheid van bos aangeeft, is er een onderdeel toegevoegd dat de bosbeheerder informatie geeft over de soorten die in het bos voor kunnen voorkomen op basis van de ligging en grootte van het bos. Voor zes diergroepen is de relatie tussen de terreinkenmerken en de habitatgeschiktheid weergegeven
The post-venous thromboembolism functional status scale: from call to action to application in research, extension to COVID-19 patients, and its use in clinical practice
A broad spectrum of long-term sequelae may be present in venous thromboembolism (VTE) survivors, affecting their quality of life and functioning. To monitor recovery and improve the prognosis of patients with persistent functional limitations, the development of a new outcome measure that could better capture the consequences of VTE was an unmet need. Starting as a call to action, the Post-VTE Functional Status (PVFS) scale was developed to meet this need. The PVFS scale is an easy-to-use clinical tool to measure and quantify functional outcomes after VTE by focusing on key aspects of daily life. As the scale was considered useful in coronavirus disease 2019 (COVID-19) patients as well, the Post-COVID-19 Functional Status (PCFS) scale was introduced early in the pandemic after slight adaptation. The scale has been well incorporated into both the VTE and COVID-19 research communities, contributing to the shift of focus toward patient-relevant functional outcomes. Psychometric properties have been evaluated, mainly for the PCFS scale but recently also for the PVFS scale, including validation studies of translations, showing adequate validity and reliability. In addition to serving as outcome measure in studies, guidelines and position papers recommend using the PVFS and PCFS scale in clinical practice. As broad use of the PVFS and PCFS scale in clinical practice is valuable to capture what matters most to patients, widespread implementation is a crucial next step. In this review, we discuss the development of the PVFS scale and introduction in VTE and COVID-19 care, the incorporation of the scale in research, and its application in clinical practice.Thrombosis and Hemostasi
Suspended sediment load in the tidal zone of an Indonesian river
Forest clearing for reasons of timber production, open pit mining and the establishment of oil palm plantations generally results in excessively high sediment loads in tropical rivers. The increasing sediment loads pose a threat to coastal marine ecosystems, such as coral reefs. This study presents observations of suspended sediment loads in the Berau River (Kalimantan, Indonesia), which debouches into a coastal ocean that is a preeminent center of coral diversity. The Berau River is relatively small and drains a mountainous, still relatively pristine basin that receives abundant rainfall. In the tidal zone of the Berau River, flow velocity was measured over a large part of the river width using a horizontal acoustic Doppler current profiler (HADCP). Surrogate measurements of suspended sediment concentration were taken with an optical backscatter sensor (OBS). Averaged over the 6.5 weeks covered by the benchmark survey period, the suspended sediment load was estimated at 2 Mt yr-1. Based on rainfall-runoff modeling though, the river discharge peak during the survey was supposed to be moderate and the yearly averaged suspended sediment load is most likely somewhat higher than 2 Mt yr-1. The consequences of ongoing clearing of rainforest were explored using a plot-scale erosion model. When rainforest, which still covered 50–60% of the basin in 2007, is converted to production land, soil loss is expected to increase with a factor between 10 and 100. If this soil loss is transported seaward as suspended sediment, the increase in suspended sediment load in the Berau River would impose a severe stress on this global hotspot of coral reef diversity
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