As part of statistical disclosure control National Statistical Offices can only deliver confidential data being sufficiently protected meeting national legislation. When releasing confidential ...microdata to users, data holders usually apply what are called anonymisation methods to the data. In order to fulfil the privacy requirements, it is possible to measure the level of privacy of some confidential data file by simulating potential data intrusion scenarios matching publicly or commercially available data with the entire set of confidential data, both sharing a non-empty set of variables (quasi-identifiers). According to real world microdata, incompatibility between data sets and not unique combinations of quasi-identifiers are very likely. In this situation, it is nearly impossible to decide whether or not two records refer to the same underlying statistical unit. Even a successful assignment of records may be a fruitless disclosure attempt, if a rationale data intruder would keep distance from that match. The paper lines out that disclosure risks estimated thus far are overrated in the sense that revealed information is always a combination of both, systematically derived results and non-negligible random assignment.
Catechins are the major group of bioactive flavanols in green tea and cacao. 17 glucansucrase-active strains were identified from a set of 41 lactic acid bacteria, which were able to glucosylate ...(+)-catechin in a non-natural acceptor reaction. In total cell free extracts of 12 Leuconostoc and 5 Weissella strains were active on catechin and also 8 cell fractions exhibited catechin glucosylation activity. Six enzymes were selected for further evaluation and enriched up to 37 fold in yields of at least 40%. Glucansucrase of L. citreum DSM 5577 was the most efficient biocatalyst for (+)-catechin transformation with conversions of >40% after 24 h. NMR analysis of the major reaction product confirmed the (+)-catechin-4′-O-α-d-glucoside. Only L. kimchi B-65337 produced a second catechin monoglucoside. Four out of six glucansucrases glucosylated esculetin and all enzymes were active on haematoxylin. Glucansucrases of L. citreum DSM 5577, L. kimchi B-65337 and W. beninensis DSM 22752 were the best suited biocatalysts with conversions of >30% for esculetin and >60% for haematoxylin. W. beninensis DSM 22752 glucansucrase produced 89% haematoxylin glucosides without process optimization. L. kimchi B-65337 and W. beninensis DSM 22752 synthesized >40% diglucosides with the bifunctional haematoxylin. NMR analysis of the purified esculetin products confirmed formation of the 6-O-α-d- and 7-O-α-d-glucosides. Also two haematoxylin monoglucosides were identified as the 9-O-α-d- and 3-O-α-d-glucosides.
Due to their pronounced bioactivity and limited availability from natural resources, metabolites of the soft coral Pseudopterogorgia elisabethae, such as erogorgiaene and the pseudopterosines, ...represent important target molecules for chemical synthesis. We have now developed a particularly short and efficient route towards these marine diterpenes exploiting an operationally convenient enantioselective cobalt‐catalyzed hydrovinylation as the chirogenic step. Other noteworthy C−C bond forming transformations include diastereoselective Lewis acid‐mediated cyclizations, a Suzuki coupling and a carbonyl ene reaction. Starting from 4‐methyl‐styrene the anti‐tubercular agent (+)‐erogorgiaene (>98 % ee) was prepared in only 7 steps with 46 % overall yield. In addition, the synthesis of the pseudopterosin A aglycone was achieved in 12 steps with 30 % overall yield and, surprisingly, was found to exhibit a similar anti‐inflammatory activity (inhibition of LPS‐induced NF‐κB activation) as a natural mixture of pseudopterosins A−D or iso‐pseudopterosin A, prepared by β‐D‐xylosylation of the synthetic aglycone.
Applied metal catalysis: Exploiting a practical protocol for the asymmetric hydrovinylation of stryrenes in the opening move, the stereoselective total synthesis of bioactive constituents of the soft coral pseudopterogorgia elisabethae was efficiently achieved in sequence of metal‐mediated steps to provide sufficient material for further biological investigations.
Twelve Leuconostoc and seven Weissella strains with extracellular glucansucrase activity were obtained from an analysis of 41 lactic acid bacteria. Culture supernatants of all glucansucrase positive ...strains catalyzed the glycosylation of caffeic acid with sucrose as donor substrate. Eighteen enzymes produced one major peak, which was identified as caffeic acid-4′-O-α-D-monoglucoside by LC-MS and NMR spectroscopy. Only W. beninensis DSM 22752 formed significant amounts of the corresponding 3´-O-α-D-monoglucoside. The Weissella strain and five Leuconostoc strains with high glycosylation activity were selected for further studies. All glucansucrases catalyzed the glycosylation of the catechol protocatechuic acid, a side-chain truncated analogue of caffeic acid. The Leuconostoc enzymes displayed a preference for the 4′-O-α-D isomer, while the DSM 22752 glucansucrase also produced the protocatechuic acid-3′-O-α-D-monoglucoside. Lower activities with non-catecholic caffeic acid derivatives and no activity with mono-methylated caffeic acid were observed with all glucansucrases. Time-course analyses confirmed that glucansucrase from L. citreum DSM 5577 was the most efficient biocatalyst for catechol glucosylation with yields of up to 74% caffeic acid glucosides after 24 h. The enzyme displayed a high regio-preference for the 4′-O-α-d-isomer and formed less than 10% oligoglucosides. Gel electrophoretic analysis and activity staining of the PEG-enriched enzyme showed a single protein band with a molecular mass of 171 kDa. The DSM 5577 glucansucrase was tolerant against the co-solvents dimethyl sulfoxide and ethanol. Kinetic analysis revealed a KM of 27.6 mM for caffeic acid and 31 mM for sucrose with kcat values of 131 s−1 and 438 s−1.
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•Nineteen glucansucrase positive Leuconostoc and Weissella strains accepted caffeic acid.•Caffeic acid-4′-O-α-D-monoglucoside was the main product.•Novel glucosides of structural analogues umbellic and protocatechuic acid were discovered.•Purified glucansucrase of L. citreum DSM 5577 produced caffeic acid glucosides in 74% yield.•The solvent tolerant enzyme possessed a KM of 27.6 mM and a kcat of 131 s−1.
Does insurance provision reduce entrepreneurs' effort to avoid business failure? We exploit unique features of the voluntary Danish unemployment insurance (UI) scheme, that is available to the ...self-employed. Using a large sample of self-employed individuals, we estimate the causal effect of insurance choice on the probability to become unemployed. Identification of the insurance choice comes from eligibility conditions for an early retirement plan, accessible only to UI members. We find that those who are insured are 2 percentage points more likely to become unemployed subsequently compared with the uninsured, however only 0.6 percentage points are caused by moral hazard.
Neuraminidase, a key enzyme responsible for influenza virus propagation, has been used as a template for selective synthesis of small subsets of its own inhibitors from theoretically highly diverse ...dynamic combinatorial libraries. We show that the library building blocks, aldehydes and amines, form significant amounts of the library components resulting from their coupling by reductive amination only in the presence of the enzyme. The target amplifies the best hits at least 120-fold. The dynamic libraries synthesized and screened in such an in vitro virtual mode form the components that possess high inhibitory activity, as confirmed by enzyme assays with independently synthesized individual compounds.
Compensatory inter vivos gifts Hochguertel, Stefan; Ohlsson, Henry
Journal of applied econometrics (Chichester, England),
September/October 2009, Letnik:
24, Številka:
6
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Parents' transfer motives are important for understanding, e.g., macroeconomics, income (re)distribution, savings, and public finance. Using data from six biennial waves of the Health and Retirement ...Study 1992-2002, we estimate censored regression models with nested multilevel error components. First, we interpret our findings that inter vivos transfers from parents to children are gifts, rather than temporary help to overcome liquidity constraints. Second, inter vivos gifts are compensatory in the sense that lifetime poorer children will receive higher transfers than their lifetime richer siblings. Third, inter vivos gifts do not, however, make up the entire difference in lifetime incomes.
New and potent inhibitors of neuraminidase, a key enzyme in the influenza virus activity, have been discovered in dynamic combinatorial libraries based on ketones and amines as building blocks. ...Selective synthesis of a number of inhibitors among multiple theoretically possible combinations of building blocks is driven by the presence of the target enzyme.
Precautionary motives and portfolio decisions Hochguertel, Stefan
Journal of applied econometrics (Chichester, England),
January/February 2003, Letnik:
18, Številka:
1
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This paper studies the empirical relevance of precautionary and other motives for household portfolio behaviour using recent panel data from the Netherlands. Dutch households' portfolios exhibit low ...degrees of risk taking and diversification. It is possible that this is the outcome of a rational, precautionary response to unavoidable exposure to background risk (stemming from the labour market or health conditions, etc.). We consider as alternative explanations liquidity needs and habits. The endogenous variable is the fraction of clearly safe in total financial assets at the household level. Parametric and semi-parametric censored regression models for pooled cross-sections and random and fixed effects models for panel data show that both heteroscedasticity and unobserved heterogeneity are of major importance in the data. With subjective indicators of income uncertainty we find a limited role for precautionary motives.
This paper analyzes the ownership dynamics of stocks and mutual funds, using representative household panel data, the Dutch CentER Savings Survey 1993-1998. A bivariate dynamic binary-choice model is ...introduced, allowing for interactions between the two types of assets. We find that unobserved heterogeneity and state dependence play a large role for both types of assets. The positive relation between ownership of one type in one period and the other type in the next period is explained by correlated unobserved heterogeneity. A negative statedependence effect of lagged ownership of stocks on ownership of mutual funds is found, which can be explained by the costs of shifting funds across the two forms of stockholding.
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