Effects of experience and opponents on pacing behavior and 2-km cycling performance of novice youths

Purpose: To study the pacing behavior and performance of novice youth exercisers in a controlled laboratory setting. Method: Ten healthy participants (seven male, three female, 15.8 ± 1.0 years) completed four, 2-km trials on a Velotron cycling ergometer. Visit 1 was a familiarization trial. Visits 2 to 4 involved the following conditions, in randomized order: no opponent (NO), a virtual opponent (starting slow and finishing fast) (OP-SLOWFAST), and a virtual opponent (starting fast and finishing slow) (OP-FASTSLOW). Repeated measurement ANOVAs (p < .05) were used to examine differences in both pacing behavior and also performance related to power output, finishing- and split times, and RPE between the four successive visits and the three conditions. Expected performance outcome was measured using a questionnaire. Results: Power output increased (F3,27 = 5.651, p = .004, η2p = .386) and finishing time decreased (F3,27 = 9.972, p .05). Conclusion: Performance was improved by an increase in experience after one visit, parallel with the ability to anticipate future workload

Molecular Aspects of Secretory Granule Exocytosis by Neurons and Endocrine Cells

Neuronal communication and endocrine signaling are fundamental for integrating the function of tissues and cells in the body. Hormones released by endocrine cells are transported to the target cells through the circulation. By contrast, transmitter release from neurons occurs at specialized intercellular junctions, the synapses. Nevertheless, the mechanisms by which signal molecules are synthesized, stored, and eventually secreted by neurons and endocrine cells are very similar. Neurons and endocrine cells have in common two different types of secretory organelles, indicating the presence of two distinct secretory pathways. The synaptic vesicles of neurons contain excitatory or inhibitory neurotransmitters, whereas the secretory granules (also referred to as dense core vesicles, because of their electron dense content) are filled with neuropeptides and amines. In endocrine cells, peptide hormones and amines predominate in secretory granules. The function and content of vesicles, which share antigens with synaptic vesicles, are unknown for most endocrine cells. However, in B cells of the pancreatic islet, these vesicles contain GABA, which may be involved in intrainsular signaling.' Exocytosis of both synaptic vesicles and secretory granules is controlled by cytoplasmic calcium. However, the precise mechanisms of the subsequent steps, such as docking of vesicles and fusion of their membranes with the plasma membrane, are still incompletely understood. This contribution summarizes recent observations that elucidate components in neurons and endocrine cells involved in exocytosis. Emphasis is put on the intracellular aspects of the release of secretory granules that recently have been analyzed in detail

Developing win-win solutions for virtual placements in informatics: The VALS case

The placements and internships are one of the main paths to get professional background and some skills for students, especially in areas like informatics and computer sciences. The European-funded VALS project tries to promote the virtual placements and establish a new initiative in virtual placements called Semester of Code. This initiative binds higher education institutions, students, companies, foundations and Open Source projects in order to create virtual placements and solve needs that they have in relation with those placements. This paper introduces some projects about virtual placements that other institutions and companies perform, also the paper describes the needs, opinions and considerations about the virtual placements for each stakeholder involved in the placements, to finally explain the design decisions and actions behind the Semester of Code, and how they are intended to get better virtual placements and successful results

Impact of colorectal cancer screening on survival after metachronous metastasis

Background: An increasing proportion of colorectal cancer (CRC) cases in Europe are detected by screening with faecal immunochemical testing (FIT). Previous studies showed that population screening with FIT leads to a decrease in CRC incidence and to detection at an earlier stage. However, approximately twenty percent of patients with CRC without metastases at initial diagnosis still develop metachronous metastases. We investigated the association between detection mode of the primary tumor and overall survival (OS) after metachronous metastasis in patients with CRC. Methods: Nationwide registry-based data was obtained of 794 patients who developed metachronous metastases after being diagnosed with stage I-III CRC between January and June 2015. With multivariable Cox PH regression modelling, we analyzed the (causal) association between detection mode of the primary tumor (FIT screen-detected versus non-screen-detected) and OS after metachronous metastasis while adjusting for potential confounders. Results: Median OS and five-year OS after metachronous metastasis were significantly higher for patients with screen-detected (n = 152) vs. non-screen-detected primary tumors (n = 642): 38.3 vs. 19.2 months, and 35.4% vs. 18.8%, respectively, p < 0.0001). After adjustment for potential confounders, the association between detection mode and OS after metachronous metastasis remained significant (HR 0.70 [95% CI 0.56–0.89]). Conclusions: Screen-detection of the primary tumor was independently associated with longer OS after metachronous metastasis. This may support the clinical utility of the population screening program and it shows the prognostic value of detection mode of the primary tumor once metachronous metastasis is diagnosed

Adjuvant chemotherapy in patients with clinically node-negative but pathologically node-positive rectal cancer in the Netherlands: A retrospective analysis

INTRODUCTION: Accurate clinical staging of rectal cancer is hampered by suboptimal sensitivity of MRI in the detection of regional lymph node metastases. Consequently, some patients may be understaged and have been withheld neoadjuvant (chemo)radiotherapy in retrospect. Although Dutch guidelines do not advocate adjuvant chemotherapy (ACT) in rectal cancer, some of these clinically understaged patients receive ACT according to local policy. We aim to assess the benefit of ACT in these patients. METHODS: Population-based data from patients with clinically node-negative (cN0) but pathologically node-positive (pN+) rectal cancer that underwent total mesorectal excision (TME) without neoadjuvant treatment between 2008 and 2018 were obtained from the Netherlands Cancer Registry. Missing data were handled by multiple imputation. Stabilised inverse probability treatment weighting (sIPTW) was used to balance clinical characteristics. Overall survival (OS) was compared in ACT and non-ACT patients. RESULTS: Of 34,724 patients, 13,861 had cN0 disease of whom 3016 were pN+ (21.8%). 1466 (48.6%) of these patients underwent upfront TME and were included. Median follow-up was 84 months (95% confidence interval [CI] 76-97) versus 79 months (95% CI 77-81) in patients that did (n = 290, 19.8%) and did not (n = 1176, 80.2%) receive ACT, respectively. After sIPTW adjustment, ACT was associated with improved OS (hazard ratio 0.70; 95% CI 0.49-0.99; p = 0.04). The estimated 5-year OS rate was 74.2% versus 65.3%, respectively. CONCLUSION: In this population-based cohort of patients with cN0 but pN+ rectal cancer who underwent upfront TME, ACT was associated with a significant OS benefit. These data support to discuss ACT in this population

Citric acid wastewater as electron donor for biological sulfate reduction

Citrate-containing wastewater is used as electron donor for sulfate reduction in a biological treatment plant for the removal of sulfate. The pathway of citrate conversion coupled to sulfate reduction and the microorganisms involved were investigated. Citrate was not a direct electron donor for the sulfate-reducing bacteria. Instead, citrate was fermented to mainly acetate and formate. These fermentation products served as electron donors for the sulfate-reducing bacteria. Sulfate reduction activities of the reactor biomass with acetate and formate were sufficiently high to explain the sulfate reduction rates that are required for the process. Two citrate-fermenting bacteria were isolated. Strain R210 was closest related to Trichococcus pasteurii (99.5% ribosomal RNA (rRNA) gene sequence similarity). The closest relative of strain S101 was Veillonella montepellierensis with an rRNA gene sequence similarity of 96.7%. Both strains had a complementary substrate range

Localization of ABCG5 and ABCG8 proteins in human liver, gall bladder and intestine

BACKGROUND: The molecular mechanisms that regulate the entry of dietary sterols into the body and their removal via hepatobiliary secretion are now beginning to be defined. These processes are specifically disrupted in the rare autosomal recessive disease, Sitosterolemia (MIM 210250). Mutations in either, but not both, of two genes ABCG5 or ABCG8, comprising the STSL locus, are now known to cause this disease and their protein products are proposed to function as heterodimers. Under normal circumstances cholesterol, but not non-cholesterol sterols, is preferentially absorbed from the diet. Additionally, any small amounts of non-cholesterol sterols that are absorbed are rapidly taken up by the liver and preferentially excreted into bile. Based upon the defects in sitosterolemia, ABCG5 and ABCG8 serve specifically to exclude non-cholesterol sterol entry at the intestinal level and are involved in sterol excretion at the hepatobiliary level. METHODS: Here we report the biochemical and immuno-localization of ABCG5 and ABCG8 in human liver, gallbladder and intestine using cell fractionation and immunohistochemical analyses. RESULTS: We raised peptide antibodies against ABCG5 and ABCG8 proteins. Using human liver samples, cell fractionation studies showed both proteins are found in membrane fractions, but they did not co-localize with caveolin-rafts, ER, Golgi or mitochondrial markers. Although their distribution in the sub-fractions was similar, they were not completely contiguous. Immunohistochemical analyses showed that while both proteins were readily detectable in the liver, ABCG5 was found predominately lining canalicular membranes, whereas ABCG8 was found in association with bile duct epithelia. At the cellular level, ABCG5 appeared to be apically expressed, whereas ABCG8 had a more diffuse expression pattern. Both ABCG5 and ABCG8 appeared to localize apically as shown by co-localization with MRP2. The distribution patterns of ABCG5 and ABCG8 in the gallbladder were very similar to each other. In the small intestine both ABCG5 and ABCG8 appear to line the brush border. However, at the level of the enterocyte, the cellular distribution patterns of ABCG5 and ABCG8 differed, such that ABCG5 was more diffuse, but ABCG8 was principally apical. Using standard deglycosylation methods, ABCG5 and ABCG8 do not appear to be glycosylated, suggesting a difference between human and mouse proteins. CONCLUSION: We report the distribution patterns of ABCG5 and ABCG8 in human tissues. Cell fractionation studies showed that both proteins co-fractionated in general, but could also be found independent of each other. As predicted, they are expressed apically in both intestine and liver, although their intracellular expression patterns are not completely congruent. These studies support the concept of heterodimerization of ABCG5 and ABCG8, but also support the notion that these proteins may have an independent function

Signatures of Selection in the Genomes of Commercial and Non-Commercial Chicken Breeds

Identifying genomics regions that are affected by selection is important to understand the domestication and selection history of the domesticated chicken, as well as understanding molecular pathways underlying phenotypic traits and breeding goals. While whole-genome approaches, either high-density SNP chips or massively parallel sequencing, have been successfully applied to identify evidence for selective sweeps in chicken, it has been difficult to distinguish patterns of selection and stochastic and breed specific effects. Here we present a study to identify selective sweeps in a large number of chicken breeds (67 in total) using a high-density (58 K) SNP chip. We analyzed commercial chickens representing all major breeding goals. In addition, we analyzed non-commercial chicken diversity for almost all recognized traditional Dutch breeds and a selection of representative breeds from China. Based on their shared history or breeding goal we in silico grouped the breeds into 14 breed groups. We identified 396 chromosomal regions that show suggestive evidence of selection in at least one breed group with 26 of these regions showing strong evidence of selection. Of these 26 regions, 13 were previously described and 13 yield new candidate genes for performance traits in chicken. Our approach demonstrates the strength of including many different populations with similar, and breed groups with different selection histories to reduce stochastic effects based on single populations