How Speededness of a Reasoning Test and the Complexity of Mental Speed Tasks Influence the Relation between Mental Speed and Reasoning Ability.

Although previous research has consistently reported a positive association between mental speed and reasoning ability, it remains unclear whether the magnitude of this association depends on whether the reasoning test is administered with or without a time limit. In addition, it is unknown how mental speed task complexity affects the mental speed-reasoning association when the effects of time limitations in the reasoning test (labeled "speededness") are controlled for. The present study examined these questions in a sample of 200 participants who completed the time-limited Culture Fair Test (CFT) and a Hick task with three levels of complexity to measure mental speed. Results showed that the latent correlation between mental speed and reasoning was slightly lower when the effect of speededness in reasoning was statistically controlled for. However, for both controlled and uncontrolled reasoning, the correlation with mental speed was of medium size and statistically significant. When reasoning was controlled for the effects of speededness, only complexity-related mental speed aspects were correlated with reasoning, whereas basic mental speed aspects were correlated with the speededness factor and unrelated to reasoning. These findings demonstrate that time limitations in reasoning tests and complexity in mental speed tasks affect the magnitude of the mental speed-reasoning association

Photoinduced host-to-guest electron transfer in a self-assembled coordination cage

A [Pd2L4] coordination cage, assembled from electron-rich phenothiazine-based ligands and encapsulating an electron-deficient anthraquinone-based disulfonate guest, is reported. Upon excitation at 400 nm, transient absorption spectroscopy unveils photoinduced electron transfer from the host's chromophores to the guest, as indicated by characteristic spectral features assigned to the oxidized donor and reduced acceptor. The structure of the host–guest complex was characterized by NMR spectroscopy, mass spectrometry and single-crystal X-ray analysis. Spectroelectrochemical experiments and DFT calculations both agree with the proposed light-induced charge separation. A kinetic analysis of the involved charge transfer channels reveals, besides a guest-independent LMCT path, 44% efficiency for the host–guest charge transfer (HGCT)

Should we design extended or straightforward questions for small stock when records are unavailable?

Data from two closely related questions in a survey on rabbits is analyzed in order to determine whether results from these two groups of questions would yield similar results about numbers of rabbits kept by a household. One question seeks a straightforward answer about numbers of rabbits kept while the other group of questions breaks the question into several questions seeking numbers of rabbits disaggregated by sex and age. This is prompted by the fact that record keeping is not a very common undertaking in a small holder agricultural setting in Kenya and that in their absence, farmers may not recall precisely how many rabbits they own unless a headcount is performed. A paired sample t test is implemented to detect any significant under-reporting of rabbit numbers based on numbers from the straightforward question which we hypothesize would yield numbers far less than what is on the farm. The results show that such under-reporting is not serious enough. The conclusion is that between the two question modes implemented in the survey, the straightforward question is suitable as it is time saving when the survey data required does not include numbers disaggregated by sex or age of rabbits

Should we design extended or straightforward questions for small stock when records are unavailable?

Data from two closely related questions in a survey on rabbits is analyzed in order to determine whether results from these two groups of questions would yield similar results about numbers of rabbits kept by a household. One question seeks a straightforward answer about numbers of rabbits kept while the other group of questions breaks the question into several questions seeking numbers of rabbits disaggregated by sex and age. This is prompted by the fact that record keeping is not a very common undertaking in a small holder agricultural setting in Kenya and that in their absence, farmers may not recall precisely how many rabbits they own unless a headcount is performed. A paired sample t test is implemented to detect any significant under-reporting of rabbit numbers based on numbers from the straightforward question which we hypothesize would yield numbers far less than what is on the farm. The results show that such under-reporting is not serious enough. The conclusion is that between the two question modes implemented in the survey, the straightforward question is suitable as it is time saving when the survey data required does not include numbers disaggregated by sex or age of rabbits

Per-arnt-sim (PAS) domain-containing protein kinase is downregulated in human islets in type 2 diabetes and regulates glucagon secretion.

AIMS/HYPOTHESIS: We assessed whether per-arnt-sim (PAS) domain-containing protein kinase (PASK) is involved in the regulation of glucagon secretion. METHODS: mRNA levels were measured in islets by quantitative PCR and in pancreatic beta cells obtained by laser capture microdissection. Glucose tolerance, plasma hormone levels and islet hormone secretion were analysed in C57BL/6 Pask homozygote knockout mice (Pask-/-) and control littermates. Alpha-TC1-9 cells, human islets or cultured E13.5 rat pancreatic epithelia were transduced with anti-Pask or control small interfering RNAs, or with adenoviruses encoding enhanced green fluorescent protein or PASK. RESULTS: PASK expression was significantly lower in islets from human type 2 diabetic than control participants. PASK mRNA was present in alpha and beta cells from mouse islets. In Pask-/- mice, fasted blood glucose and plasma glucagon levels were 25 ± 5% and 50 ± 8% (mean ± SE) higher, respectively, than in control mice. At inhibitory glucose concentrations (10 mmol/l), islets from Pask-/- mice secreted 2.04 ± 0.2-fold (p < 0.01) more glucagon and 2.63 ± 0.3-fold (p < 0.01) less insulin than wild-type islets. Glucose failed to inhibit glucagon secretion from PASK-depleted alpha-TC1-9 cells, whereas PASK overexpression inhibited glucagon secretion from these cells and human islets. Extracellular insulin (20 nmol/l) inhibited glucagon secretion from control and PASK-deficient alpha-TC1-9 cells. PASK-depleted alpha-TC1-9 cells and pancreatic embryonic explants displayed increased expression of the preproglucagon (Gcg) and AMP-activated protein kinase (AMPK)-alpha2 (Prkaa2) genes, implying a possible role for AMPK-alpha2 downstream of PASK in the control of glucagon gene expression and release. CONCLUSIONS/INTERPRETATION: PASK is involved in the regulation of glucagon secretion by glucose and may be a useful target for the treatment of type 2 diabetes

Substrate preference and phosphatidylinositol monophosphate inhibition of the catalytic domain of the PAS kinase PASKIN

The PAS domain serine/threonine kinase PASKIN, or PAS kinase, links energy flux and protein synthesis in yeast, regulates glycogen synthesis and protein translation in mammals, and might be involved in insulin regulation in the pancreas. According to the current model, binding of a putative ligand to the PAS domain disinhibits the kinase domain, leading to PASKIN autophosphorylation and increased kinase activity. Up to date, only synthetic but no endogenous PASKIN ligands have been reported. Here, we identified a number of novel PASKIN kinase targets, including ribosomal protein S6. Together with our previous identification of eukaryotic translation elongation factor eEF1A1, this suggests a role for PASKIN in the regulation of mammalian protein translation. While searching for endogenous PASKIN ligands, we found that various phospholipids can bind PASKIN and stimulate its autophosphorylation. Interestingly, strongest binding and autophosphorylation was achieved with monophosphorylated phosphatidylinositols. However, stimulated PASKIN autophosphorylation did not correlate with ribosomal protein S6 and eEF1A1 target phosphorylation. Whereas autophosphorylation was enhanced by monophosphorylated phosphatidylinositols, di- and triphosphorylated phosphatidylinositols inhibited autophosphorylation. In contrast, target phosphorylation was always inhibited, with highest efficiency of di- and tri-phosphorylated phosphatidylinositols. Since phosphatidylinositol monophosphates were found to interact with the kinase rather than with the PAS domain, these data suggest a multi-ligand regulation of PASKIN activity, including a still unknown PAS domain binding/activating ligand and kinase domain binding modulatory phosphatidylinositol phosphates

Speed- and accuracy-related measures of an intelligence test are differentially predicted by the speed and accuracy measures of a cognitive task

Raw scores on time-limited multiple-choice intelligence tests are determined by incorrect responses and missing answers. Both these error types were previously found to be negatively related to each other. Individual differences in the emphasis on speed or accuracy can explain this finding. But even though individual differences in the emphasis on speed or accuracy have been identified not only in intelligence tests but also in cognitive tasks, little is known about their interplay. Therefore the aim of the present study was to investigate to what degree speed- and accuracy-related performance scores of an intelligence test can be predicted by speed and accuracy measures of cognitive tasks, respectively. For this purpose, 200 participants completed Cattell's Culture Fair Intelligence Test (CFT 20-R) and performed the Swaps Task, an experimental cognitive task. To investigate the interplay between the speed and the accuracy measures of both kinds of task, a latent variable approach was used. Overall, the emphasis on speed or accuracy was not systematically related to the intelligence score. However, closer inspection of the data revealed that reaction times, but not errors rates, in the Swaps Task predicted the number of not-reached items as an indicator of speed in the CFT 20-R. At the same time, error rates, but not reaction times, in the Swaps Task predicted incorrect responses as an indicator of accuracy in the CFT 20-R. Taken together, speed- and accuracy-related performance scores of an intelligence test were predicted by speed and accuracy measures of a cognitive task, respectively. Most important, however, the finding that the emphasis on speed or accuracy was not significantly related to intelligence scores clearly indicated that this emphasis does not interfere with the validity of the intelligence test

The development of inductive reasoning under consideration of the effect due to test speededness

Measures of inductive reasoning are frequently used as proxy of a child’s cognitive develop-ment. Unfortunately, a reasoning scale might be affected by speededness introduced by li-mited testing time. As a result, the scale might be heterogeneous and its correlation with age is hard to interpret. Here we investigated the development of inductive reasoning when a possible bias by the effect of speededness is controlled for. In 250 children, ranging in age from 8;0 to 12;8 years, inductive reasoning assessed with the Culture Fair Test 20-R (CFT 20-R) increased with age. The effect of speededness was identified in all four CFT 20-R sub-test and was also related to age indicating increasing processing speed with higher age. After controlling for the effect of speededness, the relation between age and inductive rea-soning was still observed but substantially decreased. Consequences of these results for the description of inductive reasoning data obtained with time-limited tests and for develop-mental studies on the interplay between age, inductive reasoning and speed of information processing are discussed.scussed