993 resultados para 3D direct-write
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P>1. Entomopathogenic nematodes can function as indirect defence for plants that are attacked by root herbivores. By releasing volatile organic compounds (VOCs), plants signal the presence of host insects and thereby attract nematodes.2. Nonetheless, how roots deploy indirect defences, how indirect defences relate to direct defences, and the ecological consequences of root defence allocation for herbivores and plant biomass are essentially unknown.3. We investigate a natural below-ground tritrophic system, involving common milkweed, a specialist root-boring beetle and entomopathogenic nematodes, and asked whether there is a negative genetic correlation between direct defences (root cardenolides) and indirect defences (emission of volatiles in the roots and nematode attraction), and between constitutive and inducible defences.4. Volatiles of roots were analysed using two distinct sampling methods. First, we collected emissions from living Asclepias syriaca roots by dynamic headspace sampling. This method showed that attacked A. syriaca plants emit five times higher levels of volatiles than control plants. Secondly, we used a solid phase micro-extraction (SPME) method to sample the full pool of volatiles in roots for genetic correlations of volatile biosynthesis.5. Field experiments showed that entomopathogenic nematodes prevent the loss of biomass to root herbivory. Additionally, suppression of root herbivores was mediated directly by cardenolides and indirectly by the attraction of nematodes. Genetic families of plants with high cardenolides benefited less from nematodes compared to low-cardenolide families, suggesting that direct and indirect defences may be redundant. Although constitutive and induced root defences traded off within each strategy (for both direct and indirect defence, cardenolides and VOCs, respectively), we found no trade-off between the two strategies.6. Synthesis. Constitutive expression and inducibility of defences may trade off because of resource limitation or because they are redundant. Direct and indirect defences do not trade off, likely because they may not share a limiting resource and because independently they may promote defence across the patchiness of herbivore attack and nematode presence in the field. Indeed, some redundancy in strategies may be necessary to increase effective defence, but for each strategy, an economy of deployment reduces overall costs.
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Patient-specific simulations of the hemodynamics in intracranial aneurysms can be constructed by using image-based vascular models and CFD techniques. This work evaluates the impact of the choice of imaging technique on these simulations
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This paper presents a new registration algorithm, called Temporal Di eomorphic Free Form Deformation (TDFFD), and its application to motion and strain quanti cation from a sequence of 3D ultrasound (US) images. The originality of our approach resides in enforcing time consistency by representing the 4D velocity eld as the sum of continuous spatiotemporal B-Spline kernels. The spatiotemporal displacement eld is then recovered through forward Eulerian integration of the non-stationary velocity eld. The strain tensor iscomputed locally using the spatial derivatives of the reconstructed displacement eld. The energy functional considered in this paper weighs two terms: the image similarity and a regularization term. The image similarity metric is the sum of squared di erences between the intensities of each frame and a reference one. Any frame in the sequence can be chosen as reference. The regularization term is based on theincompressibility of myocardial tissue. TDFFD was compared to pairwise 3D FFD and 3D+t FFD, bothon displacement and velocity elds, on a set of synthetic 3D US images with di erent noise levels. TDFFDshowed increased robustness to noise compared to these two state-of-the-art algorithms. TDFFD also proved to be more resistant to a reduced temporal resolution when decimating this synthetic sequence. Finally, this synthetic dataset was used to determine optimal settings of the TDFFD algorithm. Subsequently, TDFFDwas applied to a database of cardiac 3D US images of the left ventricle acquired from 9 healthy volunteers and 13 patients treated by Cardiac Resynchronization Therapy (CRT). On healthy cases, uniform strain patterns were observed over all myocardial segments, as physiologically expected. On all CRT patients, theimprovement in synchrony of regional longitudinal strain correlated with CRT clinical outcome as quanti ed by the reduction of end-systolic left ventricular volume at follow-up (6 and 12 months), showing the potential of the proposed algorithm for the assessment of CRT.
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Malignant melanoma, the deadliest form of skin cancer, is characterized by a predominant mutation in the BRAF gene. Drugs that target tumours carrying this mutation have recently entered the clinic. Accordingly, patients are routinely screened for mutations in this gene to determine whether they can benefit from this type of treatment. The current gold standard for mutation screening uses real-time polymerase chain reaction and sequencing methods. Here we show that an assay based on microcantilever arrays can detect the mutation nanomechanically without amplification in total RNA samples isolated from melanoma cells. The assay is based on a BRAF-specific oligonucleotide probe. We detected mutant BRAF at a concentration of 500 pM in a 50-fold excess of the wild-type sequence. The method was able to distinguish melanoma cells carrying the mutation from wild-type cells using as little as 20 ng µl(-1) of RNA material, without prior PCR amplification and use of labels.
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PURPOSE: To investigate magnetization transfer (MT) effects as a new source of contrast for imaging and tracking of peripheral foot nerves. MATERIALS AND METHODS: Two sets of 3D spoiled gradient-echo images acquired with and without a saturation pulse were used to generate MT ratio (MTR) maps of 260 μm in-plane resolution for eight volunteers at 3T. Scan parameters were adjusted to minimize signal loss due to T2 dephasing, and a dedicated coil was used to improve the inherently low signal-to-noise ratio of small voxels. Resulting MTR values in foot nerves were compared with those in surrounding muscle tissue. RESULTS: Average MTR values for muscle (45.5 ± 1.4%) and nerve (21.4 ± 3.1%) were significantly different (P < 0.0001). In general, the difference in MTR values was sufficiently large to allow for intensity-based segmentation and tracking of foot nerves in individual subjects. This procedure was termed MT-based 3D visualization. CONCLUSION: The MTR serves as a new source of contrast for imaging of peripheral foot nerves and provides a means for high spatial resolution tracking of these structures. The proposed methodology is directly applicable on standard clinical MR scanners and could be applied to systemic pathologies, such as diabetes.
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The subject of this study is the use of direct cinema style in documentary film. The main purpose of this thesis was to the research the ways in which direct cinema style attempts to show and achieve truth in documentary films. The following questions were posed: Is it possible to depict reality in a documentary film; how does the choice of using this style affect the final documentary? The essential purpose of this study was to try to see whether the direct cinema style works when trying to achieve truth in a documentary film. This work consints of two elements, the theoretical part and the short documentary. The theoretical part deals with the history, the truth, and the direct cinema- style in documentaries. The theoretical information of direct cinema has been used when making the short documentary. In the documentary Tuloaula 2 I have studied the way in which using direct cinema -style works in practise. The documentary has followed as strictly as possible the direct cinema style. I was the director, the cameraman and the editor of my documentary film. In the documentary film Tuloaula 2 it appeared that the direct cinema style works best when filming everyday life. By using this style it is easy for the director to observe and leave his own persona in the background. The strength in using the direct cinema style is that it enables the viewer to build his/her own impression on the subject. Even though the direct cinema style aims to achieve objectivity the director has to make numerous subjective choices during both the filming and the editing process. These subjective choices automatically effect the "truth" of the documentary film. The difficulty in a direct cinema style is the large amount of material. This often leads to a long editing phase, which is not often possible in the busy production schedules. The direct cinema style is not at its best when shooting people who are passive because their attention often focuses too much on the camera. In general, the best way to make a documentary film would be to use many documentary styles in one film and not to srictly concentrate on only one style.
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Opinnäytteeni teososana on 3D-Kalevala projektinimellä tunnetun animaation partikkeliefektit. Tarkastelen tarkemmin elokuvan Lumi-, Kylä-, Paja- ja Luola-kohtauksia. 3D-Kalevala on tietokoneella tehty animaatio, joka kertoo Suomen kansalliseepoksen Kalevalan päähenkilöstä Väinämöisestä. Elokuvassa vanha Väinämöinen muistelee nuoruutensa tapahtumia. 3D-Kalevala-projekti käynnistettiin vuonna 2003, mutta sen alkuperäiset tekijät eivät saaneet sitä valmiiksi, ja projektin teko keskeytettiin vuonna 2005. Vuoden 2006 keväällä projektiin perustettiin uusi kahden verkkoviestinnän opiskelijan projektiryhmä, jonka tehtävänä oli saada elokuva valmiiksi vuoden 2007 kevääseen mennessä. Kun aloitimme projektin tekemisen, olin kolmiulotteisessa mallinnuksessa aloittelija. Tästä johtuen opinnäytteen kirjallinen osa on opas aloittelijoille partikkelien maailmaan. Selvitän raportissani miten elokuvan partikkeliefektit rakennettiin, mitä niiden tekeminen minulta vaati ja miten ne loppujen lopuksi mielestäni onnistuivat. Elokuvan efektit tehtiin 3D Studio Max-ohjelman versiolla 6.0, ja tämän takia kirjoitankin efektien rakentamisesta kyseisen ohjelman keinoin. Projektin suuruuden vuoksi molemmat tekijät pääsivät tekemään monenlaisia töitä, mutta päävastuualueet olivat selvät. Minun osani oli tehdä elokuvaan efektejä. Partikkeliefektit ovat proseduraalisia efektejä, joiden avulla on mahdollista tehdä aidon näköisiä luonnonilmiöitä, kuten tulta, savua, kipinöitä ja veden roiskeita. Koska partikkeliefektit mallintavat reaalimaailman ilmiöitä, on tekijän hyvä olla kiinnostunut selvittämään ilmiöiden käyttäytymistä luonnossa. Raportoin myös projektin aikana huomaamistani hyvistä tavoista opiskella itsenäisesti partikkelien rakentamiseen käytettyjä tekniikoita. On hyvä lukea 3D Studio Maxin tasokasta käyttöohjesovellusta, tutustua Internetissä löytyviin 3D-aiheisiin foorumeihin, käydä aiheesta tutoriaaleja läpi sekä tutustua ohjelman ominaisuuksiin kokeilemalla ja tutkimalla itsenäisesti. Elokuvan efektit onnistuivat mielestäni kiitettävästi ottaen huomioon lähtötasoni. Löysin tapoja kehittää itseäni ja helppoja keinoja toteuttaa realistista jälkeä efektien rakentamisessa. Toivon, että raportistani olisi jollekin 3D-partikkeliefekteistä kiinnostuneelle hyötyä.
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Opinnäytetyöni aiheena on keskeytyneen uusmediatuotannon jatkaminen. Monimuototyön työosana toteutettiin 7-minuuttinen 3D animaatio, joka kertoo Suomen kansalliseepoksen Kalevalan taruhahmosta Väinämöisestä, muistelemassa menneitä. Projekti käynnistettiin alun perin vuonna 2003, mutta resurssien vähetessä se keskeytyi vuoden 2005 loppupuolella. Keväällä 2006 projekti käynnistettiin uuden projektiryhmän voimin, jossa olin itse mukana vastaten muun muassa tuotannonohjauksesta ja hahmoanimoinneista. Uusi projektiryhmä oli henkilöstöresursseiltaan pieni, joten vastuualueet olivat monipuolisia. Keskeytyneen projektin jatkamisen ja haltuunoton haasteellisuus sai minut kiinnostumaan tutkia aihetta tarkemmin. Tuotannonohjaajana vastasin hyvin pitkälle tuotannon uudesta käynnistämisestä ja projektin saattamisesta vihdoin loppuun. Keskeytyneen projektin haltuunotto oli tilanteena kaikille uusi, mikä heijastui vaikeuksina uudelleen käynnistettyyn tuotantoon. Raportin tarkoituksena ei ole olla projektinhallinnallinen käsikirja, sillä käsittelen vain tämän projektin jatkolle oleellisina pidettyjä asioita. Projekti toivottavasti kuitenkin antaa kuvan huolellisen projektinhallinnan ja onnistuneen tuotannonohjauksen tärkeydestä. Jokainen keskeytynyt projekti ei ole aina välttämättä elvytettävissä - ainakaan alkuperäisessä muodossaan. Projektin jatkamista tulisi katsoa aina tapauskohtaisesti. Keskeytymiseen on useimmiten syynsä, joten ongelmien selvittäminen ja niihin puuttuminen on tärkeää ennen jatkopäätöksen tekemistä. Myös projektityöskentelytavat kehittyvät ja pohdin työssäni uusien projektinhallintatapojen, kuten wikien käyttöä projektinhallinnan työkaluna ja projektiyhteisön välistä viestintää edistävänä työkaluna.
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Financial markets play an important role in an economy performing various functions like mobilizing and pooling savings, producing information about investment opportunities, screening and monitoring investments, implementation of corporate governance, diversification and management of risk. These functions influence saving rates, investment decisions, technological innovation and, therefore, have important implications for welfare. In my PhD dissertation I examine the interplay of financial and product markets by looking at different channels through which financial markets may influence an economy.My dissertation consists of four chapters. The first chapter is a co-authored work with Martin Strieborny, a PhD student from the University of Lausanne. The second chapter is a co-authored work with Melise Jaud, a PhD student from the Paris School of Economics. The third chapter is co-authored with both Melise Jaud and Martin Strieborny. The last chapter of my PhD dissertation is a single author paper.Chapter 1 of my PhD thesis analyzes the effect of financial development on growth of contract intensive industries. These industries intensively use intermediate inputs that neither can be sold on organized exchange, nor are reference-priced (Levchenko, 2007; Nunn, 2007). A typical example of a contract intensive industry would be an industry where an upstream supplier has to make investments in order to customize a product for needs of a downstream buyer. After the investment is made and the product is adjusted, the buyer may refuse to meet a commitment and trigger ex post renegotiation. Since the product is customized to the buyer's needs, the supplier cannot sell the product to a different buyer at the original price. This is referred in the literature as the holdup problem. As a consequence, the individually rational suppliers will underinvest into relationship-specific assets, hurting the downstream firms with negative consequences for aggregate growth. The standard way to mitigate the hold up problem is to write a binding contract and to rely on the legal enforcement by the state. However, even the most effective contract enforcement might fail to protect the supplier in tough times when the buyer lacks a reliable source of external financing. This suggests the potential role of financial intermediaries, banks in particular, in mitigating the incomplete contract problem. First, financial products like letters of credit and letters of guarantee can substantially decrease a risk and transaction costs of parties. Second, a bank loan can serve as a signal about a buyer's true financial situation, an upstream firm will be more willing undertake relationship-specific investment knowing that the business partner is creditworthy and will abstain from myopic behavior (Fama, 1985; von Thadden, 1995). Therefore, a well-developed financial (especially banking) system should disproportionately benefit contract intensive industries.The empirical test confirms this hypothesis. Indeed, contract intensive industries seem to grow faster in countries with a well developed financial system. Furthermore, this effect comes from a more developed banking sector rather than from a deeper stock market. These results are reaffirmed examining the effect of US bank deregulation on the growth of contract intensive industries in different states. Beyond an overall pro-growth effect, the bank deregulation seems to disproportionately benefit the industries requiring relationship-specific investments from their suppliers.Chapter 2 of my PhD focuses on the role of the financial sector in promoting exports of developing countries. In particular, it investigates how credit constraints affect the ability of firms operating in agri-food sectors of developing countries to keep exporting to foreign markets.Trade in high-value agri-food products from developing countries has expanded enormously over the last two decades offering opportunities for development. However, trade in agri-food is governed by a growing array of standards. Sanitary and Phytosanitary standards (SPS) and technical regulations impose additional sunk, fixed and operating costs along the firms' export life. Such costs may be detrimental to firms' survival, "pricing out" producers that cannot comply. The existence of these costs suggests a potential role of credit constraints in shaping the duration of trade relationships on foreign markets. A well-developed financial system provides the funds to exporters necessary to adjust production processes in order to meet quality and quantity requirements in foreign markets and to maintain long-standing trade relationships. The products with higher needs for financing should benefit the most from a well functioning financial system. This differential effect calls for a difference-in-difference approach initially proposed by Rajan and Zingales (1998). As a proxy for demand for financing of agri-food products, the sanitary risk index developed by Jaud et al. (2009) is used. The empirical literature on standards and norms show high costs of compliance, both variable and fixed, for high-value food products (Garcia-Martinez and Poole, 2004; Maskus et al., 2005). The sanitary risk index reflects the propensity of products to fail health and safety controls on the European Union (EU) market. Given the high costs of compliance, the sanitary risk index captures the demand for external financing to comply with such regulations.The prediction is empirically tested examining the export survival of different agri-food products from firms operating in Ghana, Mali, Malawi, Senegal and Tanzania. The results suggest that agri-food products that require more financing to keep up with food safety regulation of the destination market, indeed sustain longer in foreign market, when they are exported from countries with better developed financial markets.Chapter 3 analyzes the link between financial markets and efficiency of resource allocation in an economy. Producing and exporting products inconsistent with a country's factor endowments constitutes a serious misallocation of funds, which undermines competitiveness of the economy and inhibits its long term growth. In this chapter, inefficient exporting patterns are analyzed through the lens of the agency theories from the corporate finance literature. Managers may pursue projects with negative net present values because their perquisites or even their job might depend on them. Exporting activities are particularly prone to this problem. Business related to foreign markets involves both high levels of additional spending and strong incentives for managers to overinvest. Rational managers might have incentives to push for exports that use country's scarce factors which is suboptimal from a social point of view. Export subsidies might further skew the incentives towards inefficient exporting. Management can divert the export subsidies into investments promoting inefficient exporting.Corporate finance literature stresses the disciplining role of outside debt in counteracting the internal pressures to divert such "free cash flow" into unprofitable investments. Managers can lose both their reputation and the control of "their" firm if the unpaid external debt triggers a bankruptcy procedure. The threat of possible failure to satisfy debt service payments pushes the managers toward an efficient use of available resources (Jensen, 1986; Stulz, 1990; Hart and Moore, 1995). The main sources of debt financing in the most countries are banks. The disciplining role of banks might be especially important in the countries suffering from insufficient judicial quality. Banks, in pursuing their rights, rely on comparatively simple legal interventions that can be implemented even by mediocre courts. In addition to their disciplining role, banks can promote efficient exporting patterns in a more direct way by relaxing credit constraints of producers, through screening, identifying and investing in the most profitable investment projects. Therefore, a well-developed domestic financial system, and particular banking system, would help to push a country's exports towards products congruent with its comparative advantage.This prediction is tested looking at the survival of different product categories exported to US market. Products are identified according to the Euclidian distance between their revealed factor intensity and the country's factor endowments. The results suggest that products suffering from a comparative disadvantage (labour-intensive products from capital-abundant countries) survive less on the competitive US market. This pattern is stronger if the exporting country has a well-developed banking system. Thus, a strong banking sector promotes exports consistent with a country comparative advantage.Chapter 4 of my PhD thesis further examines the role of financial markets in fostering efficient resource allocation in an economy. In particular, the allocative efficiency hypothesis is investigated in the context of equity market liberalization.Many empirical studies document a positive and significant effect of financial liberalization on growth (Levchenko et al. 2009; Quinn and Toyoda 2009; Bekaert et al., 2005). However, the decrease in the cost of capital and the associated growth in investment appears rather modest in comparison to the large GDP growth effect (Bekaert and Harvey, 2005; Henry, 2000, 2003). Therefore, financial liberalization may have a positive impact on growth through its effect on the allocation of funds across firms and sectors.Free access to international capital markets allows the largest and most profitable domestic firms to borrow funds in foreign markets (Rajan and Zingales, 2003). As domestic banks loose some of their best clients, they reoptimize their lending practices seeking new clients among small and younger industrial firms. These firms are likely to be more risky than large and established companies. Screening of customers becomes prevalent as the return to screening rises. Banks, ceteris paribus, tend to focus on firms operating in comparative-advantage sectors because they are better risks. Firms in comparative-disadvantage sectors finding it harder to finance their entry into or survival in export markets either exit or refrain from entering export markets. On aggregate, one should therefore expect to see less entry, more exit, and shorter survival on export markets in those sectors after financial liberalization.The paper investigates the effect of financial liberalization on a country's export pattern by comparing the dynamics of entry and exit of different products in a country export portfolio before and after financial liberalization.The results suggest that products that lie far from the country's comparative advantage set tend to disappear relatively faster from the country's export portfolio following the liberalization of financial markets. In other words, financial liberalization tends to rebalance the composition of a country's export portfolio towards the products that intensively use the economy's abundant factors.
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The aim of this study was to compare the diagnostic efficiency of plain film and spiral CT examinations with 3D reconstructions of 42 tibial plateau fractures and to assess the accuracy of these two techniques in the pre-operative surgical plan in 22 cases. Forty-two tibial plateau fractures were examined with plain film (anteroposterior, lateral, two obliques) and spiral CT with surface-shaded-display 3D reconstructions. The Swiss AO-ASIF classification system of bone fracture from Muller was used. In 22 cases the surgical plans and the sequence of reconstruction of the fragments were prospectively determined with both techniques, successively, and then correlated with the surgical reports and post-operative plain film. The fractures were underestimated with plain film in 18 of 42 cases (43%). Due to the spiral CT 3D reconstructions, and precise pre-operative information, the surgical plans based on plain film were modified and adjusted in 13 cases among 22 (59%). Spiral CT 3D reconstructions give a better and more accurate demonstration of the tibial plateau fracture and allows a more precise pre-operative surgical plan.
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Quantitative research that aimed to identify the mean total cost (MTC) of connecting, maintaining and disconnecting patient-controlled analgesia pump (PCA) in the management of pain. The non-probabilistic sample corresponded to the observation of 81 procedures in 17 units of the Central Institute of the Clinics Hospital, Faculty of Medicine, University of Sao Paulo. We calculated the MTC multiplying by the time spent by nurses at a unit cost of direct labor, adding the cost of materials and medications/solutions. The MTC of connecting was R$ 107.91; maintenance R$ 110.55 and disconnecting R$ 4.94. The results found will subsidize discussions about the need to transfer money from the Unified Health System to hospitals units that perform this technique of analgesic therapy and it will contribute to the cost management aimed at making efficient and effective decision-making in the allocation of available resources.
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Hyperammonemic disorders in pediatric patients lead to poorly understood irreversible effects on the developing brain that may be life-threatening. We showed previously that some of these NH4+-induced irreversible effects might be due to impairment of axonal growth that can be protected under ammonium exposure by creatine co-treatment. The aim of the present work was thus to analyse how the genes of arginine:glycine amidinotransferase (AGAT) and guanidinoacetate methyltransferase (GAMT), allowing creatine synthesis, as well as of the creatine transporter SLC6A8, allowing creatine uptake into cells, are regulated in rat brain cells under NH4+ exposure. Reaggregated brain cell three-dimensional cultures exposed to NH4Cl were used as an experimental model of hyperammonemia in the developing central nervous system (CNS). We show here that NH4+ exposure differentially alters AGAT, GAMT and SLC6A8 regulation, in terms of both gene expression and protein activity, in a cell type-specific manner. In particular, we demonstrate that NH4+ exposure decreases both creatine and its synthesis intermediate, guanidinoacetate, in brain cells, probably through the inhibition of AGAT enzymatic activity. Our work also suggests that oligodendrocytes are major actors in the brain in terms of creatine synthesis, trafficking and uptake, which might be affected by hyperammonemia. Finally, we show that NH4+ exposure induces SLC6A8 in astrocytes. This suggests that hyperammonemia increases blood-brain barrier permeability for creatine. This is normally limited due to the absence of SLC6A8 from the astrocyte feet lining microcapillary endothelial cells, and thus creatine supplementation may protect the developing CNS of hyperammonemic patients.
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Background: To compare treatment outcomes of a cognitive-behavioral long-term (CBT-L) and short-term (CBT-S) treatment for binge eating disorder (BED) in a non-randomized comparison and to identify moderators of treatment outcome. Methods: 76 female patients with BED participated in the study: 40 in CBT-L and 36 in CBT-S. Outcome values were compared at the end of the active treatment phase (16 sessions for CBT-L, 8 sessions for CBT-S) and at 12-month follow-up. Results: Both treatments produced significant reductions in binge eating. At the end of active treatment, but not at the end of follow-up, effects of primary outcomes (e.g. remission from binge eating, EDE shape concern) were better for CBT-L than for CBT-S. Dropout rates were significantly higher in CBT-L (35%) than in CBT-S (14%). Moderator analyses revealed that treatment efficacy for rapid responders and individuals exhibiting high scores on the mixed dietary negative affect subtype differed between the CBT-L and CBT-S with respect to objective binges, restraint eating and eating concern. Conclusion: Findings suggest that CBT in general represents an effective treatment for BED, but that subgroups of patients might profit more from a prolonged treatment. Short, lessintensive CBT treatments could nevertheless be a viable option in the treatment of BED.