Experimental Studies on the Carboxymethylation of Arrowroot Starch in Isopropanol‐Water Media

The reaction between granular arrowroot starch and sodium monochloroacetate (SMCA) in isopropanol‐water mixtures has been studied in a systematic way using experimental design strategies. The effect of six factors, i.e. the theoretical degree of substitution (DS_t), reaction time, weight fraction of water in the mixture, NaOH/SMCA ratio, temperature and weight fraction of starch on three responses, i.e. the degree of substitution (DS), the conversion of SMCA and the selectivity of SMCA towards carboxymethyl starch, has been determined in a systematic manner. Granular carboxymethyl arrowroot starch with a maximum DS of 1.4 could be prepared in a singlestep procedure. The results are compared with data obtained for potato starch. Similar trends for all responses were observed, suggesting close similarities between the chemical composition and the topochemistry of granular arrowroot‐ and potato‐starch.     

Food reinforcement, the dopamine D? receptor genotype, and energy intake in obese and nonobese humans: Erratum.

Reports an error in "Food reinforcement, the dopamine D? receptor genotype, and energy intake in obese and nonobese humans" by Leonard H. Epstein, Jennifer L. Temple, Brad J. Neaderhiser, Robbert J. Salis, Richard W. Erbe and John J. Leddy (Behavioral Neuroscience, 2007[Oct], Vol 121[5], 877-886). In the original article, the n values (and corresponding percentages) for the number of people with the A1/A1 & A1/A2 and A2/A2 genotypes were reversed in Table 2. The corrected table appears in the erratum, with the revised numbers appearing in bold font. (The following abstract of the original article appeared in record 2007-13974-007.) The authors measured food reinforcement, polymorphisms of the dopamine D? receptor (DRD?) and dopamine transporter (DAT1) genes, and laboratory energy intake in 29 obese and 45 nonobese humans 18-40 years old. Food reinforcement was greater in obese than in nonobese individuals, especially in obese individuals with the TaqI A1 allele. Energy intake was greater for individuals high in food reinforcement and greatest in those high in food reinforcement with the TaqI A1 allele. No effect of the DAT1 genotype was observed. These data show that individual differences in food reinforcement may be important for obesity and that the DRD? genotype may interact with food reinforcement to influence energy intake. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The performance of the Amoeba distributed operating system

Amoeba is a capability-based distributed operating system designed for high-performance interactions between clients and servers using the well-known RPC model. The paper starts out by describing the architecture of the Amoeba system, which is typified by specialized components such as workstations, several services, a processor pool, and gateways that connect other Amoeba systems transparently over wide-area networks. Next the RPC interface is described. The paper presents performance measurements of the Amoeba RPC on unloaded and loaded systems. The time to perform the simplest RPC between two user processes has been measured to be 1-4 ms. Compared to SUN 3/50's RPC, Amoeba has one ninth of the delay, and over three times the throughput. Finally we describe the Amoeba file server. The Amoeba file server is so fast that it is limited by the communication bandwidth. To the best of our knowledge this is the fastest file server yet reported in the literature for this class of hardware.     

Drought Governance in Transition: a Case Study of the Meuse River Basin in the Netherlands

Water Resources Management - The Netherlands is internationally renowned for its flood risk management, but three consecutive dry years between 2018–2020 fuelled the debate on how to deal...     

Chemical Solution Deposition of Epitaxial La1−x (Ca, Sr) x MnO3 Thin Films

We report on the epitaxial growth of magnetoresistive La_0.7Ca_0.3MnO₃ and La_0.7Sr_0.3MnO₃ thin films by chemical solution deposition. Thin films were prepared by spin-coating of single-crystal LaAlO₃ (100) substrates with precursor solutions of different concentrations and crystallized at 850°C. The structure of the thin film was found to be influenced by the concentration of the spin-coating solution. The thin film structure and epitaxy was clearly improved by reducing the concentration of the precursor solution. All thin films displayed excellent electrical properties such as a low resistivity and very high metal-insulator transition temperatures T _MI .     

Segregation of biomass in cyclic anaerobic/aerobic granular sludge allows the enrichment of anaerobic ammonium oxidizing bacteria at low temperatures

A cyclic anaerobic/aerobic bubble column reactor was run for 420 days to study the competition for nitrite between nitrite oxidizing bacteria (NOB) and anaerobic ammonium oxidizing bacteria (Anammox) at low temperatures. An anaerobic feeding period with nitrite and ammonium in the influent followed by an aerated period was applied resulting in a biomass specific conversion rate of 0.18 ± 0.02 [gN(2) - N · gVSS(-1)· day(-1)] when the dissolved oxygen concentration was maintained at 1.0 mgO(2) · L(-1). An increase in white granules was observed in the reactor which were mainly located at the top of the settled sludge bed, whereas red granules were located at the bottom. FISH, activity tests, and qPCR techniques revealed that red biomass was dominated by Anammox bacteria and white granules by NOB. Granules from the top of the sludge bed were smaller and therefore had a higher aerobic volume fraction, a lower density, and consequently a slower settling rate. Sludge was manually removed from the top of the settled sludge bed to selectively remove NOB which resulted in an increased overall biomass specific N-conversion rate of 0.32 ± 0.02 [gN(2) - N · gVSS(-1) · day(-1)]. Biomass segregation in granular sludge reactors gives an extra opportunity to select for specific microbial groups by applying a different SRT for different microbial groups.     

Synthesis of Stable NAD+ Mimics as Inhibitors for the Legionella pneumophila Phosphoribosyl Ubiquitylating Enzyme SdeC

Stable NAD⁺ analogues carrying single atom substitutions in either the furanose ring or the nicotinamide part have proven their value as inhibitors for NAD⁺-consuming enzymes. To investigate the potential of such compounds to inhibit the adenosine diphosphate ribosyl (ADPr) transferase activity of the Legionella SdeC enzyme, we prepared three NAD⁺ analogues, namely carbanicotinamide adenosine dinucleotide (c-NAD⁺), thionicotinamide adenosine dinucleotide (S-NAD⁺) and benzamide adenosine dinucleotide (BAD). We optimized the chemical synthesis of thionicotinamide riboside and for the first time used an enzymatic approach to convert all three ribosides into the corresponding NAD⁺ mimics. We thus expanded the known scope of substrates for the NRK1/NMNAT1 enzyme combination by turning all three modified ribosides into NAD⁺ analogues in a scalable manner. We then compared the three NAD⁺ mimics side-by-side in a single assay for enzyme inhibition on Legionella effector enzyme SdeC. The class of SidE enzymes to which SdeC belongs was recently identified to be important in bacterial virulence, and we found SdeC to be inhibited by S-NAD⁺ and BAD with IC₅₀ values of 28 and 39 μM, respectively.     

Spousal support and changes in distress over time in couples coping with cancer: The role of personal control.

This longitudinal study has examined the associations between perceived supportive and unsupportive spousal behavior and changes in distress in couples coping with cancer. We tested whether people relatively low in their sense of personal control were more responsive to spousal supportive and unsupportive behavior than were people relatively high in personal control. Patients with colorectal cancer and their partners (n = 70) completed questionnaires at two assessment points: 3 (at baseline) and 9 months (at follow-up) after the diagnosis. We assessed perceived spousal supportive (SSL) and unsupportive (SSL-N) behavior, sense of personal control (Pearlin & Schooler's Mastery), and depressive symptoms (CES-D) in both patients and partners. Multilevel analysis (MLwiN) was used to examine changes in distress over time in a dyadic context. Patients and partners who perceived more spousal support reported less distress over time, but this only applied to those relatively low in personal control. Moreover, partners who perceived more unsupportive spousal behavior reported more distress, again only if they were relatively low in personal control. Patients and partners relatively high in personal control reported relatively low levels of distress, regardless of spousal behavior. In conclusion, people relatively low in personal control may be more adversely affected by unsupportive behavior and benefit more from supportive behavior than people relatively high in personal control. (PsycINFO Database Record (c) 2011 APA, all rights reserved)