Student Questioning:what does questioning reveal about prior knowledge, historical reasoning and affect?

Students ask historical questions when they are engaged in historical reasoning and trying to understand a particular historical phenomenon. Student questioning can be regarded as the engine and a destination of historical reasoning. This study is aimed at deeper insight into thinking processes underlying students’ historical questions using a general model of questioning and a domain-specific model of historical reasoning. Thirty-three secondary school students were instructed to read a text and underline striking text segments. At the point of underlining, students were asked to verbalize their thoughts. In our protocol analysis we focused on the questions students spontaneously asked while verbalizing their prior knowledge, reasoning, and feelings. It appeared that in half of the 251 analyzed fragments (episodes) students verbalized an extent of historical reasoning and expressed feelings. Questions were mostly asked when students expressed a knowledge deficit, but spontaneous questions were also present in episodes with historical reasoning and episodes with affective responses. All components, activating prior knowledge, realizing a knowledge deficit, historical reasoning and experiencing affective thoughts, help students to ask their questions and help them to process the introduction into a historical topic

Orthostatic Hypotension and the Long-Term Risk of Dementia: A Population-Based Study

Background: Orthostatic hypotension (OH) is a common cause of transient cerebral hypoperfusion in the population. Cerebral hypoperfusion is widely implicated in cognitive impairment, but whether OH contributes to cognitive decline and dementia is uncertain. We aimed to determine the association between OH and the risk of developing dementia in the general population. Methods and Findings: Between 4 October 1989 and 17 June 1993, we assessed OH in non-demented, stroke-free participants of the population-based Rotterdam Study. OH was defined as a ≥20 mm Hg drop in systolic blood pressure (SBP) or ≥10 mm Hg drop in diastolic blood pressure (DBP) within 3 min from postural change. We furthermore calculated within participant variability in SBP related to postural change, expressed as coefficient of variation. Follow-up for dementia was conducted until 1 January 2014. We determined the risk of dementia in relation to OH and SBP variability, using a Cox regression model, adjusted for age; sex; smoking status; alcohol intake; SBP; DBP; cholesterol:high-density lipoprotein ratio; diabetes; body mass index; use of antihypertensive, lipid-lowering, or anticholinergic medication; and apolipoprotein E genotype. Finally, we explored whether associations varied according to compensatory increase in heart rate. Among 6,204 participants (mean ± standard deviation [SD] age 68.5 ± 8.6 y, 59.7% female) with a median follow-up of 15.3 y, 1,176 developed dementia, of whom 935 (79.5%) had Alzheimer disease and 95 (8.1%) had vascular dementia. OH was associated with an increased risk of dementia (adjusted hazard ratio [aHR] 1.15, 95% CI 1.00–1.34, p = 0.05), which was similar for Alzheimer disease and vascular dementia. Similarly, greater SBP variability with postural change was associated with an increased risk of dementia (aHR per SD increase 1.08, 95% CI 1.01–1.16, p = 0.02), which was similar when excluding those who fulfilled the formal criteria for OH (aHR 1.08, 95% CI 1.00–1.17, p = 0.06). The risk of dementia was particularly increased in those with OH who lacked a compensatory increase in heart rate (within lowest quartile of heart rate response: aHR 1.39, 95% CI 1.04–1.85, p-interaction = 0.05). Limitations of this study include potential residual confounding despite rigorous adjustments, and potentially limited generalisability to populations not of European descent. Conclusions: In this population predominantly of European descent, OH was associated with an increase in long-term risk of dementia

Structural and biophysical characterization of the tandem substrate-binding domains of the ABC importer GlnPQ

The ATP-binding cassette transporter GlnPQ is an essential uptake system that transports glutamine, glutamic acid and asparagine in Gram-positive bacteria. It features two extra-cytoplasmic substrate-binding domains (SBDs) that are linked in tandem to the transmembrane domain of the transporter. The two SBDs differ in their ligand specificities, binding affinities and their distance to the transmembrane domain. Here, we elucidate the effects of the tandem arrangement of the domains on the biochemical, biophysical and structural properties of the protein. For this, we determined the crystal structure of the ligand-free tandem SBD1-2 protein from Lactococcus lactis in the absence of the transporter and compared the tandem to the isolated SBDs. We also used isothermal titration calorimetry to determine the ligand-binding affinity of the SBDs and single-molecule Förster resonance energy transfer (smFRET) to relate ligand binding to conformational changes in each of the domains of the tandem. We show that substrate binding and conformational changes are not notably affected by the presence of the adjoining domain in the wild-type protein, and changes only occur when the linker between the domains is shortened. In a proof-of-concept experiment, we combine smFRET with protein-induced fluorescence enhancement (PIFE–FRET) and show that a decrease in SBD linker length is observed as a linear increase in donor-brightness for SBD2 while we can still monitor the conformational states (open/closed) of SBD1. These results demonstrate the feasibility of PIFE–FRET to monitor protein–protein interactions and conformational states simultaneously

Higher education is associated with a lower risk of dementia after a stroke or TIA

__Background:__ Higher education is associated with a lower risk of dementia, possibly because of a higher tolerance to subclinical neurodegenerative pathology. Whether higher education also protects against dementia after clinical stroke or transient ischemic attack (TIA) remains unknown. __Methods:__ Within the population-based Rotterdam Study, 12,561 participants free of stroke, TIA and dementia were followed for occurrence of stroke, TIA and dementia. Across the levels of education, associations of incident stroke or TIA with subsequent development of dementia and differences in cognitive decline following stroke or TIA were investigated. __Results:__ During 124,862 person-years, 1,463 persons suffered a stroke or TIA, 1,158 persons developed dementia, of whom 186 developed dementia after stroke or TIA. Risk of dementia after a stroke or TIA, compared to no stroke or TIA, was highest in the low education category (hazards ratio [HR] 1.46, 95% CI 1.18-1.81) followed by intermediate education category (HR 1.36, 95% CI 1.03-1.81). No significant association was observed in the high education category (HR 0.62, 95% CI 0.25-1.54). In gender stratified analyses, decrease in risk of dementia with increasing education was significant only in men. __Conclusion:__ Higher education is associated with a lower risk of dementia after stroke or TIA, particularly in men, which might be explained by a higher cognitive reserve

Butyrate oxidation attenuates the butyrate-induced improvement of insulin sensitivity in myotubes

Skeletal muscle insulin resistance is a key pathophysiological process that precedes the development of type 2 diabetes. Whereas an overload of long-chain fatty acids can induce muscle insulin resistance, butyrate, a short -chain fatty acid (SCFA) produced from dietary fibre fermentation, prevents it. This preventive role of butyrate has been attributed to histone deacetylase (HDAC)-mediated transcription regulation and activation of mito-chondrial fatty-acid oxidation. Here we address the interplay between butyrate and the long-chain fatty acid palmitate and investigate how transcription, signalling and metabolism are integrated to result in the butyrate -induced skeletal muscle metabolism remodelling. Butyrate enhanced insulin sensitivity in palmitate-treated, insulin-resistant C2C12 cells, as shown by elevated insulin receptor 1 (IRS1) and pAKT protein levels and Slc2a4 (GLUT4) mRNA, which led to a higher glycolytic capacity. Long-chain fatty-acid oxidation capacity and other functional respiration parameters were not affected. Butyrate did upregulate mitochondrial proteins involved in its own oxidation, as well as concentrations of butyrylcarnitine and hydroyxybutyrylcarnitine. By knocking down the gene encoding medium-chain 3-ketoacyl-CoA thiolase (MCKAT, Acaa2), butyrate oxidation was inhibited, which amplified the effects of the SCFA on insulin sensitivity and glycolysis. This response was associated with enhanced HDAC inhibition, based on histone 3 acetylation levels. Butyrate enhances insulin sensitivity and induces glycolysis, without the requirement of upregulated long-chain fatty acid oxidation. Butyrate catabolism functions as an escape valve that attenuates HDAC inhibition. Thus, inhibition of butyrate oxidation indirectly prevents insulin resistance and stimulates glycolytic flux in myotubes treated with butyrate, most likely via an HDAC-dependent mechanism.Diabetes mellitus: pathophysiological changes and therap

Plasma amyloid-β40 in relation to subclinical atherosclerosis and cardiovascular disease: A population-based study.

BACKGROUND AND AIMS We aimed to determine associations of plasma amyloid-β40 (Aβ40) with subclinical atherosclerosis and risk of atherosclerotic cardiovascular disease (ASCVD) in the general population. METHODS Between 2002 and 2005, plasma Aβ40 was measured by single molecule array (SiMoA®) in 3879 participants of the population-based Rotterdam Study (mean age: 71 years, 61% female). Subclinical atherosclerosis was quantified as computed tomography-assessed calcification volumes. We determined the association of Aβ40 with calcification volumes and clinical ASCVD event risk, and repeated the analyses for ASCVD in a replication cohort of 1467 individuals. RESULTS Higher levels of Aβ40 were associated with increased volumes of calcification in the coronary arteries and to a lesser extent extracranial carotid arteries, independent of traditional cardiovascular risk factors. Of all 3879 participants, 748 developed ASCVD during a median 9.7 years of follow-up. In age- and sex-adjusted models, higher Aβ40 predisposed to a minor increase in ASCVD risk (HR [95%CI]: 1.11[1.02-1.21] per 1-SD increase in Aβ40), driven by coronary heart disease (HR: 1.17[1.05-1.29]) rather than stroke (HR: 1.04[0.93-1.16]). However, excess risk of clinical outcomes was largely explained by baseline differences in cardiovascular risk factors and attenuated after further adjustment (for ASCVD- HR: 1.05[0.96-1.15] and for CHD- HR: 1.08[0.96-1.20]). Results were similar in the replication cohort, with highest risk estimates for CHD (HR: 1.24[1.04-1.48]) in age- and sex-adjusted models, attenuated after adjustment for cardiovascular risk factors (HR: 1.15[0.96-1.39]). CONCLUSIONS In this population-based study, higher plasma amyloid-β40 is associated with subclinical atherosclerosis, but not risk of first-ever ASCVD after accounting for traditional cardiovascular risk factors

Connected Growth: developing a framework to drive inclusive growth across a city-region

This ‘in perspective’ piece addresses the (re-)positioning of civil society within new structures of city-region governance within Greater Manchester (GM). This follows on from the processes of devolution, which have given the Greater Manchester City-Region (GMCR) a number of new powers. UK devolution, to date, has been largely focused upon engendering agglomerated economic growth at the city-region scale. Within GMCR, devolution for economic development has sat alongside the devolution of health and social care (unlike any other city-region in the UK) as well. Based on stakeholder mapping and semi-structured interviews with key actors operating across the GMCR, the paper illustrates how this has created a number of significant tensions and opportunities for civil society actors, as they have sought to contest a shifting governance framework. The paper, therefore, calls for future research to carefully consider how civil society groups are grappling with devolution; both contesting and responding to devolution. This is timely given the shifting policy and political discourse towards the need to deliver more socially-inclusive city-regions

Impaired Very-Low-Density Lipoprotein catabolism links hypoglycemia to hypertriglyceridemia in Glycogen Storage Disease type Ia

International audiencePrevention of hypertriglyceridemia is one of the biomedical targets in Glycogen Storage Disease type Ia (GSD Ia) patients, yet it is unclear how hypoglycemia links to plasma triglyceride (TG) levels. We analyzed whole-body TG metabolism in normoglycemic (fed) and hypoglycemic (fasted) hepatocyte-specific glucose-6-phosphatase deficient (L-G6pc-/- ) mice. De novo fatty acid synthesis contributed substantially to hepatic TG accumulation in normoglycemic L-G6pc-/- mice. In hypoglycemic conditions, enhanced adipose tissue lipolysis was the main driver of liver steatosis, supported by elevated free fatty acid concentrations in GSD Ia mice and GSD Ia patients. Plasma very-low-density lipoprotein (VLDL) levels were increased in GSD Ia patients and in normoglycemic L-G6pc-/- mice, and further elevated in hypoglycemic L-G6pc-/- mice. VLDL-TG secretion rates were doubled in normo- and hypoglycemic L-G6pc-/- mice, while VLDL-TG catabolism was selectively inhibited in hypoglycemic L-G6pc-/- mice. In conclusion, fasting-induced hypoglycemia in L-G6pc-/- mice promotes adipose tissue lipolysis and arrests VLDL catabolism. This mechanism likely contributes to aggravated liver steatosis and dyslipidemia in GSD Ia patients with poor glycemic control and may explain clinical heterogeneity in hypertriglyceridemia between GSD Ia patients

Cowpox Virus Transmission from Rats to Monkeys, the Netherlands

We report an outbreak of cowpox virus among monkeys at a sanctuary for exotic animals. Serologic analysis and polymerase chain reaction were performed on blood and swab samples from different rodent species trapped at the sanctuary during the outbreak. Sequence comparison and serologic results showed that brown rats (Rattus norvegicus) transmitted the virus to monkeys