Ghent University

About: Ghent University is a education organization based out in Ghent, Belgium. It is known for research contribution in the topics: Population & Context (language use). The organization has 36170 authors who have published 111042 publications receiving 3774501 citations. The organization is also known as: UGent & University of Ghent.

Comparison of overweight and obesity prevalence in school-aged youth from 34 countries and their relationships with physical activity and dietary patterns

Abstract: The purposes of this systematic review were to present and compare recent estimates of the prevalence of overweight and obesity in school-aged youth from 34 countries and to examine associations between overweight and selected dietary and physical activity patterns. Data consisted of a cross-sectional survey of 137 593 youth (10-16 years) from the 34 (primarily European) participating countries of the 2001-2002 Health Behaviour in School-Aged Children Study. The prevalence of overweight and obesity was determined based on self-reported height and weight and the international child body mass index standards. Logistic regression was employed to examine associations between overweight status with selected dietary and physical activity patterns. The two countries with the highest prevalence of overweight (pre-obese + obese) and obese youth were Malta (25.4% and 7.9%) and the United States (25.1% and 6.8%) while the two countries with the lowest prevalence were Lithuania (5.1% and 0.4%) and Latvia (5.9% and 0.5%). Overweight and obesity prevalence was particularly high in countries located in North America, Great Britain, and south-western Europe. Within most countries physical activity levels were lower and television viewing times were higher in overweight compared to normal weight youth. In 91% of the countries examined, the frequency of sweets intake was lower in overweight than normal weight youth. Overweight status was not associated with the intake of fruits, vegetables, and soft drinks or time spent on the computer. In conclusion, the adolescent obesity epidemic is a global issue. Increasing physical activity participation and decreasing television viewing should be the focus of strategies aimed at preventing and treating overweight and obesity in youth.

Complete nitrification by a single microorganism

Abstract: Nitrification is a two-step process where ammonia is first oxidized to nitrite by ammonia-oxidizing bacteria and/or archaea, and subsequently to nitrate by nitrite-oxidizing bacteria. Already described by Winogradsky in 18901, this division of labour between the two functional groups is a generally accepted characteristic of the biogeochemical nitrogen cycle2. Complete oxidation of ammonia to nitrate in one organism (complete ammonia oxidation; comammox) is energetically feasible, and it was postulated that this process could occur under conditions selecting for species with lower growth rates but higher growth yields than canonical ammonia-oxidizing microorganisms3. Still, organisms catalysing this process have not yet been discovered. Here we report the enrichment and initial characterization of two Nitrospira species that encode all the enzymes necessary for ammonia oxidation via nitrite to nitrate in their genomes, and indeed completely oxidize ammonium to nitrate to conserve energy. Their ammonia monooxygenase (AMO) enzymes are phylogenetically distinct from currently identified AMOs, rendering recent acquisition by horizontal gene transfer from known ammonia-oxidizing microorganisms unlikely. We also found highly similar amoA sequences (encoding the AMO subunit A) in public sequence databases, which were apparently misclassified as methane monooxygenases. This recognition of a novel amoA sequence group will lead to an improved understanding of the environmental abundance and distribution of ammonia-oxidizing microorganisms. Furthermore, the discovery of the long-sought-after comammox process will change our perception of the nitrogen cycle.

Basic psychological need satisfaction, need frustration, and need strength across four cultures

Abstract: The present study investigated whether satis- faction and frustration of the psychological needs for autonomy, relatedness, and competence, as identified within Basic Psychological Need Theory (BPNT; Deci and Ryan, Psychol Inquiry 11:227-268, 2000; Ryan and Deci, Psychol Inquiry 11:319-338, 2000), contributes to participants' well-being and ill-being, regardless of their cultural back- ground and interpersonal differences in need strength, as indexed by either need valuation (i.e., the stated importance of the need to the person) or need desire (i.e., the desire to get a need met). In Study 1, involving late adolescents from Belgium and China (total N = 685; Mean age = 17 years), autonomy and competence satisfaction had unique associations with well-being and individual differences in need valuation did not moderate these associations. Study 2 involved participants from four culturally diverse nations (Belgium, China, USA, and Peru; total N = 1,051; Mean age = 20 years). Results provided evidence for the mea- surement equivalence of an adapted scale tapping into both need satisfaction and need frustration. Satisfaction of each of the three needs was found to contribute uniquely to the prediction of well-being, whereas frustration of each of the three needs contributed uniquely to the prediction of ill- being. Consistent with Study 1, the effects of need satis- faction and need frustration were found to be equivalent across the four countries and were not moderated by indi- vidual differences in the desire for need satisfaction. These findings underscore BPNT's universality claim, which states that the satisfaction of basic needs for autonomy, relatedness, and competence represent essential nutrients for optimal functioning across cultures and across individ- ual differences in need strength.

Application of a suite of 16S rRNA-specific oligonucleotide probes designed to investigate bacteria of the phylum cytophaga-flavobacter-bacteroides in the natural environment.

Abstract: We designed a panel of four 16S rRNA-targeted oligonucleotide probes specific for bacteria of the phylum cytophaga-flavobacter-bacteroides (CFB). Probes CF319a and CF319b are targeted to members of the flavobacteria-cytophaga group and the genus Porphyromonas, whereas probe BAC303 has a target region characteristic for the genera Prevotella and Bacteroides within the bacteroides group. The probe FFE8b was developed for species-specific hybridizations with Flavobacterium ferrugineum. All probes were designed by computer-assisted sequence analysis and compared to all currently accessible 16S and 23S rRNA sequences. The oligonucleotides were further evaluated by whole-cell and non-radioactive dot-blot hybridization against reference strains of the CFB phylum and other major lineages of Bacteria. The newly developed probes were used together with other higher-order probes to analyse the structure and community composition in complex environments. In activated sludge samples, members of the flavobacteria-cytophaga group were revealed by in situ hybridization as important constituents of sludge flocs and characteristic colonizers of filamentous bacteria. By application of fluorescent probe BAC303, members of the genera Bacteroides and Prevotella could be visualized without prior cultivation as an important part of the human faecal microflora.