40 research outputs found

    Dual Valorization of Lignin as a Versatile and Renewable Matrix for Enzyme Immobilization and (Flow) Bioprocess Engineering

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    Lignin has emerged as an attractive alternative in the search for more eco-friendly and less costly materials for enzyme immobi- lization. In this work, the terephthalic aldehyde-stabilization of lignin is carried out during its extraction to develop a series of functionalized lignins with a range of reactive groups (epoxy, amine, aldehyde, metal chelates). This expands the immobiliza- tion to a pool of enzymes (carboxylase, dehydrogenase, trans- aminase) by different binding chemistries, affording immobiliza- tion yields of 64–100%. As a proof of concept, a ω- transaminase reversibly immobilized on polyethyleneimine- lignin is integrated in a packed-bed reactor. The stability of the immobilized biocatalyst is tested in continuous-flow deamina- tion reactions and maintains the same conversion for 100 cycles. These results outperform previous stability tests carried out with the enzyme covalently immobilized on methacrylic resins, with the advantage that the reversibility of the immobilized enzyme allows recycling and reuse of lignin beyond the enzyme inactivation. Additionally, an in-line system also based on lignin is added into the downstream process to separate the reaction products by catch-and-release. These results demonstrate a fully closed-loop sustainable flow- biocatalytic system based exclusively on lignin

    Age and skill bias of trade liberalisation? : heterogeneous employment effects of EU Eastern Enlargement

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    This study analyses the 2004 Eastern Enlargement to the European Union to obtain evidence on the employment effects of an increase in trade liberalisation. The Enlargement is thought to generate a trade-induced demand shock with no (or only limited) supply effects. Besides the variation over time induced by the Enlargement, identification of the effects is based on a Melitz (2003) type productivity term to differentiate firms by the extent of exposure to the demand shock. The idea is that the effects of the demand shock should be driven by differences in firm-level productivity from the period before the new member countries actually entered the EU. German linked employer-employee data allow to observe the relation of initial establishment productivity with employment changes over a long panel from 1995 to 2009. The estimates show that the Enlargement had a negative effect on establishment-level employment growth, which is driven by increased worker separations and increased job destruction. Besides the overall employment effect, the study focuses on effect heterogeneity across age and skill groups of the workforce. These estimates point to a skill bias in the effect of the Enlargement that disadvantages low- and medium-skilled workers in terms of higher worker separation and job destruction. In addition, lowskilled workers suffer fewer accessions by firms, where against medium-skilled workers enjoy increased accessions and creation of new jobs. Besides this indication for a skill bias, there are no clear indications that point to an age bias in the employment effect of the Eastern Enlargement

    Congenital and childhood atrioventricular blocks: pathophysiology and contemporary management

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    Atrioventricular block is classified as congeni- tal if diagnosed in utero, at birth, or within the first month of life. The pathophysiological process is believed to be due to immune-mediated injury of the conduction system, which occurs as a result of transplacental pas- sage of maternal anti-SSA/Ro-SSB/La antibodies. Childhood atrioventricular block is therefore diagnosed between the first month and the 18th year of life. Genetic variants in multiple genes have been described to date in the pathogenesis of inherited progressive car- diac conduction disorders. Indications and techniques of cardiac pacing have also evolved to allow safe perma- nent cardiac pacing in almost all patients, including those with structural heart abnormalities

    The Decline of Early Retirement Pathways in the Netherlands: An Empirical Analysis for the Health Care Sector

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    Early retirement schemes and disability insurance in the Netherlands have both been reformed during the past decades. The reforms have increased incentives to continue working and have decreased the substitution between early retirement and disability. This study investigates the impact of the reforms on labour market exit probabilities. We use administrative data for workers in the Dutch health care sector between 1999 and 2006. We estimate a multinomial Logit model for transitions out of the labour force. The empirical results suggest that the reforms have been effective, as the labour market participation rate of the elderly has increased. The concept of substitute pathways into retirement seems less relevant today as the results confirm that disability insurance is closed off as an early retirement exit route

    The Efficiency and Equity of the Tax and Transfer System in France

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    Taxes and cash transfers reduce income inequality more in France than elsewhere in the OECD, because of the large size of the flows involved. But the system is complex overall. Its effectiveness could be enhanced in many ways, for example so as to achieve the same amount of redistribution at lower cost. This Working Paper relates to the 2013 OECD Economic Review of France (www.oecd.org/eco/surveys/France).http://deepblue.lib.umich.edu/bitstream/2027.42/133065/1/wp1047.pd

    Prediksi Kenaikan atau Penurunan Indeks Pasar Keuangan Indonesia dengan Menggunakan Bayesian Network

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    Investasi saham pada pasar keuangan dilakukan untuk meningkatkan aset pada masa depan. Dalam melakukan investasi harus mempertimbangkan hasil yang akan didapatkan atau biasa disebut return. Setiap investor akan berusaha mendapatkan return semaksimal mungkin dari investasi yang dilakukannya. Oleh karena itu, perlu dilakukan prediksi perubahan kenaikan atau penurunan pada pasar saham. Beberapa metode untuk membuat prediksi adalah Bayesian Network dan Algoritma Naive Bayes. Pada Tugas Akhir ini, dilakukan pemodelan jaringan sektor-sektor pasar keuangan Indonesia dengan menggunakan Bayesian Network, lalu melakukan prediksi berdasarkan kenaikan atau penurunan harga penutupan dari tiap sektor. Metode yang digunakan adalah menggunakan Algoritma Naive Bayes Diskrit dan Kontinu. Setelah itu, menentukan metode yang terbaik untuk perhitungan prediksi dengan melihat tingkat akurasi dari setiap metode dengan confusion matrix. Sektor pasar keuangan yang digunakan yaitu nilai tukar USD/IDR, IHSG, dan Obligasi. Perhitungan dilakukan berdasarkan ketergantungan antara nilai tukar USD/IDR terhadap IHSG, dan nilai tukar USD/IDR terhadap Obligasi. Metode Naive Bayes Diskrit menunjukan hasil yang lebih akurat dengan akurasi sebesar 84% untuk IHSG dan 76% untuk Obligasi. Sedangkan perhitungan dengan metode Naive Bayes Kontinu memiliki akurasi sebesar 52% untuk IHSG dan 48% untuk Obligasi. Sektor nilai tukar USD/IDR lebih mempengaruhi IHSG, karena tingkat akurasi yang diperoleh IHSG lebih tinggi dibandingkan dengan Obligasi
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