Oligosaccharyltransferase: the central enzyme of N-linked protein glycosylation

Abtract: N-linked glycosylation is one of the most abundant modifications of proteins in eukaryotic organisms. In the central reaction of the pathway, oligosaccharyltransferase (OST), a multimeric complex located at the membrane of the endoplasmic reticulum, transfers a preassembled oligosaccharide to selected asparagine residues within the consensus sequence asparagine-X-serine/threonine. Due to the high substrate specificity of OST, alterations in the biosynthesis of the oligosaccharide substrate result in the hypoglycosylation of many different proteins and a multitude of symptoms observed in the family of congenital disorders of glycosylation (CDG) type I. This review covers our knowledge of human OST and describes enzyme composition. The Stt3 subunit of OST harbors the catalytic center of the enzyme, but the function of the other, highly conserved, subunits are less well defined. Some components seem to be involved in the recognition and utilization of glycosylation sites in specific glycoproteins. Indeed, mutations in the subunit paralogs N33/Tusc3 and IAP do not yield the pleiotropic phenotypes typical for CDG type I but specifically result in nonsyndromic mental retardation, suggesting that the oxidoreductase activity of these subunits is required for glycosylation of a subset of proteins essential for brain developmen

Low Energy Availability and Carbohydrate Intake in Competitive Adolescent Sport Climbers

Competitive adolescent sport climbers are reported to keep very low energy intake in order to achieve the highest possible strength-to-mass ratio required for their sport. Long term low energy availability (< 30 kcal/kg fat free mass/day) is known to have a detrimental effect on health and performance. Due to the potential severity of the consequences and the lack of the data on specific population, our aim was to assess energy availability and dietary intake of 27 members of the Slovenian Youth Climbing Team (13–18 years of age). Three-day food and activity records, questionnaires and anthropometric measurements were used to determine participants’ energy availability, nutritional intake, avoidance of food groups and selected health history. Average energy availability in climbers was 27.5 ± 9.8 kcal/kg fat free mass/day and 63% of participants failed to meet the recommended 30 kcal/kg fat free mass/day. Their average carbohydrate (4.3 ± 1.3 g/kg body mass/day), calcium (780 ± 300 mg/day) and vitamin D (2.6 ± 2.3 µg/day) intake were also too low. Average protein intake was in recommended range, but 56% of participants did not meet the minimum recommended limit. Iron intake was too low in females (10 ± 5 mg/day; target 15 mg/day). Only 15% of participants reported not avoiding any food groups. The menstrual dysfunction was detected in five female climbers (36%); all had energy availability < 30 kcal/kg fat free mass/day. We recommend nutritional education of climbers, their coaches, and parents as well as regular individual nutritional assessment of competitive adolescent sport climbers

Coverage Bias in European Telephone Surveys: Developments of Landline and Mobile Phone Coverage across Countries and over Time

With the decrease of landline phones in the last decade, telephone survey methodologists face a new challenge to overcome coverage bias. In this study we investigate coverage error for telephone surveys in Europe over time and compare two situations: classical surveys that rely on landline only with surveys that also include mobile phones. We analyzed Eurobarometer data, which are collected by means of face-to-face interviews and contain information on ownership of landline and mobile phones. We show that for the period 2000-2009, time has a significant effect on both mobile phone penetration and coverage bias. In addition, the countries’ development significantly affects the pace of these changes

Coverage Bias in European Telephone Surveys: Developments of Landline and Mobile Phone Coverage across Countries and over Time

With the decrease of landline phones in the last decade, telephone survey methodologists face a new challenge to overcome coverage bias. In this study we investigate coverage error for telephone surveys in Europe over time and compare two situations: classical surveys that rely on landline only with surveys that also include mobile phones. We analyzed Eurobarometer data, which are collected by means of face-to-face interviews and contain information on ownership of landline and mobile phones. We show that for the period 2000-2009, time has a significant effect on both mobile phone penetration and coverage bias. In addition, the countries’ development significantly affects the pace of these changes

Optimal layout proposal of technological workplaces at a small mechanical engineering company

Diplomová práce je zaměřena na technologické projektování v malém podniku ENGITEC Motosport s.r.o. V první teoretické části práce je podrobně toto téma popsáno a rozebráno jak z hlediska ekonomického, tak i technického. V další části je popsán současný stav firmy potažmo výrobní haly i s ohledem na současné dispoziční řešení. V následujících kapitolách je vybrána typická součást v podobě pístu, který firma vyrábí a jsou navrženy tři různé varianty výroby pístu. Poté je vybrána jedna z nich, k níž jsou vztaženy veškeré kapacitní propočty. V závěrečné části práce je navrženo vhodné finální dispoziční řešení haly a nechybí ani technicko-ekonomické zhodnocení nejvýhodnější varianty.This master´s thesis is focused on technological designing in a small company ENGITEC Motosport s.r.o. In first theoretical part of the thesis is this subject described in detail and analyzed in terms of economic and technical aspect. Next part describes the current state of the company and the production hall as well with keep on its current layout. In the following chapters is chosen piston-shaped component, which is manufactured by the company and three different variants of the piston production. Then one of them is selected, to which all related capacities calculations are made. In the final part of the thesis is proposed the relevant final layout of the hall and there is also the technical-economic evaluation of the most relevant variant included. Key words

DRUGAČIJI SAT POVIJESTI: »IGRAM ULOGU, POVJESNIČAR SAM!«

Učitelji postajemo svjesni važnosti igre uloga na nastavi povijesti tek kada je izvodimo. Radi se o snažnoj aktivaciji misaonih procesa koja u učenicima pobuđuju zanimanje i na taj način stečeno znanje učenik ne zaboravlja. Simulacija odnosno igranje uloga na nastavi povijesti može se izvoditi od prvih nastavnih sadržaja u 6. razredu i sigurna sam da izvrsno služi u nastavnim sadržajima učenika. Uz pomoć ove vrste iskustvene situacije, učenici će lako osvijestiti povijesnu temu, možda je lakše naučiti i shvatiti posljedicu događaja/situacije u odabranom prostoru i vremenu. Ne samo da povezuje učenike, često opušta i monotonu atmosferu koja je najveći inhibitor učeničke znatiželje. Igra uloga kod učenika potiče najviše misaone procese i pomaže da se nastavno gradivo internalizira. Ne smijemo zaboraviti činjenicu da je u ovoj vrsti nastavne metode učenik aktivni sudionik procesa učenja, što u njemu pobuđuje dodatnu motivaciju za rad. Igranje uloga pokazalo se učinkovitim sredstvom poučavanja povijesti među mojim učenicima, a u ovom članku predstavljam nekoliko scenarija za nastavne teme kod kojih je moguća primjena takve metode učenja

PRAKTIČNI PRIMJERI OBILJEŽAVANJA MEĐUNARODNOG DANA SJEĆANJA NA HOLOKAUST U OSNOVNOJ ŠKOLI

Obilježavanje Međunarodnog dana sjećanja na holokaust zapravo je važan podsjetnik za učenike osnovnih škola, koji polako postaju odrasli mladi ljudi. Podizanje svijesti o važnoj prekretnici u ljudskoj povijesti počinje odgovarajućim obrazovanjem. Obilježavanjem možemo pomoći da se takve grozote više nikada ne ponove. Pri tome učitelji, kao prenositelji informacija, imaju vrlo važnu ulogu, jer je antisemitizam (kao dio kurikuluma) također uključen u nastavni plan i program osnovne škole, točnije u program 9. razreda. Kod današnje generacije učenika devetih razreda možemo zapaziti slabljenje empatije, emocija i razumijevanja ovih užasnih događanja, pa im je ovu nastavnu temu potrebno približiti kroz povijesne izvore iz prve ruke, točnije kroz osobna svjedočanstva, jer se učenici lakše poistovjećuju s ljudima koji su to zaista doživjeli odnosno stvarnim likovima. Viša razina razumijevanja može se postići zahvaljujući slikama i filmovima snimljenim na temelju svjedočanstava. Stoga svake godine izrađujemo tzv. leptire nade i šaljemo ih u svijet. Pritom ističem kritičnost učenika i vrednovanje ovog povijesnog problema. Mnogi učenici također zaplaču i postanu svjesni strahota nacizma. Veliki naglasak stavljam na stigmatizaciju ovog povijesnog problema, jer učitelji ne smiju dozvoliti da tako nešto potone u zaborav. Antisemitizam je problem 20. stoljeća koji se ne smije izostaviti iz odgoja i obrazovanja djece