Mali učenici otkrivaju svoje strategije učenja

A 10 year-old child can develop partial language awareness of the foreign language he/she is learning. The study presents the resultsof interviews following a test in reading and writing. With this procedure children have an opportunity to evaluate their own performance and, in so doing, are taught how to control the learning process. This leads to learner autonomy

Upotreba pitanja u razrednom govoru

The question is the most frequently used move in classroom discourse. Its role is more for checking knowledge than seeking information. The teachet-\u27s role status gives him the right to choose both the topic of conversation and the person to be questioned - the learner, so in classroom dialogue we find a close correlation between role-relationship and verbal behaviour. The leamer is not only obliged to answer the question but he must give the answer the teacher expects from him. Questions in classroom dialogue therefore carrya large part of command force in themselves. In the paper the classroom questions are analysed on a corpus of French lessons carried out in a number of Zagreb primary and secondary schools. It is shown that the classroom questions have various functions: they can ask for information but they can also transmit information; on the other hand, assertions can also contain interrogation. The role relations also reveal some psychological components, such as irony as the manifestation of the teacheľs subjective attitude towards a message or a leamer. In comparison with natural dialogue, the classroom dialogue mostly shows didactic goals i.e. the focus on the correct form of the utterance more than on its content, as well as the absence of the learnefs personal opinion in the utterance

Učim francuski jezik

The present research investigates the 10 year old leame1s`way of thinking about the procedures they use when learning a foreign language. It evaluates children\u27s awareness concerning listening, speaking, reading and writing. Two questionnaires were used aiming to show at what activities children show a more analytical or a more synthetical way of thinking. The results have been analysed and discussed

Die Wirkung von Amitrol auf den Feinbau junger Chloroplasten

Growing plants of Zea mays, Phaseolus vulgaris, Elodea canadensis, Elodea densa and Wolffia arrhiza were treated with 10-4 to 10-2M solutions of amitrole and investigated by light and electron microscopy at different intervals after chlorosis appeared in the leaves. It has been shown that only those plastids were affected by amitrole which were in the stage of differentiation during the treatment. In addition to changes already known the light microscope revealed characteristic crystals of carotenoids in damaged plastids. In the electron microscope considerable changes in the ultrastructure have been found. Instead of normal grana there appear long lamellae stuck together. Some of them show a clear striation (period: 12—13 nm) in cross section. In plane sections this striation has been shown to be identical with hexagonally arranged globular particles (diameter 7—8 nm). The possible relations of this structure to the molecular organisation of the normal thylakoids and other details are discussed.Mlade biljke (Zea mays, Phaseolus vulgaris, Elodea canadensis, Elodea densa i Wolffia arrhiza) tretirane su 10-4 do 10-2M otopinama ami- trola te istražene svjetlosnim i elektronskim mikroskopom u različitim vremenskim razmacima nakon što se pojavila kloroza. Pokazalo se da su djelovanjem amitrola promijenjeni samo oni klo- roplasti koji su se u vrijeme tretmana nalazili u stadiju diferencijacije. Pored već poznatih promjena svjetlosnim mikroskopom zapaženi su u oštećenim kloroplastima karakteristični kristali karotenoida. U elektronskom mikroskopu primijećene su u kloroplastima znatne promjene. Umjesto normalnih grana pojavljuju se duge slijepljene lamele, od kojih neke pokazuju u presjeku jasno pruganje (perioda: 12—13 nm). U plošno prerezanim takvim lamelama to se pruganje pokazalo identičnim s heksagonalnim rasporedom globularnih čestica promjera 7—8 nm. Diskutirane su moguće veze te strukture s makromolekularnom organizacijom normalnih tilakoida i druge pojedinosti.Junge Pflanzen von Zea mays, Phaseolus vulgaris, Elodea canadensis, Elodea densa und Wolffia arrhiza wurden mit 10-4 bis 10-2 M Lösungen von Amitrol behandelt und nach dem Auftreten der Chlorose in verschiedenen Zeitabschnitten lichmikroskopisch und elektronenmikroskopisch untersucht. Die vorliegenden Untersuchungen haben gezeigt, dass nur jene Plasti- den angegriffen werden, die sich während der Behandlung im Stadium der Differenzierung befinden. Neben den bereits bekannten Veränderungen konnten im Lichtmikroskop in geschädigten Chloroplasten charakteristische Carotinoid-Kristalle festgestellt werden. Das Elektronenmikroskop zeigte wesentliche Veränderungen im Feinbau der Plastiden. Statt der normalen Grana erscheinen lange zusammengeklebte Lamellen. Einige dieser Lamellen zeigen im Schnitt eine feine Streifung (Periode 12 — 13 nm). An flachgeschnittenen Lamellen sieht man, dass diese Streifung durch Überlagerung von hexagonal angeordneten kugelförmingen Teilchen (Durchmesser 7 —8 nm) zustande kommt. Die möglichen Beziehungen dieser Struktur zur makromolekularen Organisation der normalen Thylakoiden und andere Einzelheiten werden diskutiert

Fluorescencijska hibridizacija in situ (FISH) u detekciji kromosomskih oštećenja nastalih kao posljedica profesionalne izloženosti ionizirajućem zračenju

For more than two decades, chromosome aberration analysis has been used in biomonitoring of occupational and environmental exposure to ionising radiation. Chromosome aberration analysis is a method used to detect unstable aberrations in the lymphocytes of irradiated personnel. In turn, stable chromosome aberrations that arise some time after exposure are detected using the multicolour fluorescence in situ hybridisation. This is a technique which dyes each pair of chromosomes with different colour. Due to the dynamics of unstable aberration formation, chromosome aberration analysis is more suitable for genome damage assessment of recent exposures. On the other hand, fluorescence in situ hybridisation gives information on chromosome instability caused by long-time occupational exposure to ionising radiation. Considering the high cost of fluorescence in situ hybridisation and the uncertainty of the result, it should be used in biodosimetry only when it is absolutely necessary.Posljednjih dvadesetak godina analiza kromosomskih aberacija rabi se kao glavna citogenetička tehnika u biodozimetriji osoba profesionalno izloženih zračenju. Metoda omogućava utvrđivanje prisutnosti nestabilnih tipova oštećenja u limfocitima ozračenih osoba. Međutim, njome nije moguće istodobno utvrditi i prisutnost stabilnih tipova oštećenja kao što su translokacije. U tu svrhu potrebno se koristiti višebojnom fluorescencijskom hibridizacijom in situ (mFISH) kojom je moguće svaki par kromosoma obojiti drugom bojom. Zbog same dinamike nastanka nestabilnih kromosomskih oštećenja analiza kromosomskih aberacija, kao citogenetička tehnika, prikladnija je za procjenu genomskih oštećenja u kratkom vremenu nakon ozračivanja, dok bi FISH mogao naći primjenu u detekciji stabilnih oštećenja genoma koja nastaju kao posljedica dugotrajne profesionalne izloženosti zračenju. Međutim, zbog visokih troškova same tehnike i zahtjevnosti njezine izvedbe, FISH kao tehnika u biodozimetriji rabila bi se samo u slučajevima kada podatke o stupnju oštećenja genoma nije moguće dobiti primjenom ni jedne druge citogenetičke tehnike

Glucose transporters in the mammalian blood cells

Glucose is the main source of metabolic energy for various cellular functions, and thus plays a central role in supporting intermediary metabolism and cellular homeostasis. Since plasma membrane is impermeable to glucose, its cellular uptake is mediated by two distinct processes via specific glucose transporter proteins that belong to the family of solute carriers (SLC); the SLC2 family members, GLUTs (glucose transporters), are sodium-independent facilitators of the glucose transport, whereas the SLC5 family members, SGLTs (sodium and glucose transporters) mediate the secondary-active sodium- glucose cotransport. Until now, 14 GLUTs and 12 SGLTs isoforms have been identified in humans of which 5 GLUTs and none SGLTs were detected in the mammalian blood cells. Detailed physiological function, precise mechanism of transport, substrates affinity, exact three-dimensional structures, and a precise tissue distribution of most GLUTs in various mammalian organs, including blood, have been poorly explored. In this review we will focus on GLUTs in the mammalian blood cells, where the data on their expression and functional roles are contradictory or largely missing. Since many GLUTs are associated with diabetes, and are up-regulated in cancers, it is undoubtedly important to further investigate GLUTs expression in different organs/tissues, including the blood cells. Understanding the complexity of glucose homeostasis that includes knowledge about tissue distribution and function of GLUTs, as well as the signaling pathways that regulate glucose metabolism, may help to develop new therapeutic strategies to target specific diseases, such as diabetes mellitus, some autoimmunity diseases, and cancer

Ruxolitinib for the treatment of myelofibrosis: its clinical potential

Ruxolitinib is an orally bioavailable, selective Janus kinase (JAK) 1 and 2 inhibitor approved for the treatment of myelofibrosis (MF), a bone marrow disease in which the JAK pathway is dysregulated, leading to impaired hematopoiesis and immune function. By inhibiting JAK1 and JAK2, ruxolitinib modulates cytokine-stimulated intracellular signaling. In a phase II clinical trial in patients with MF, ruxolitinib recipients exhibited durable reductions in spleen size, reductions in circulating pro-inflammatory cytokines, improvements in physical activity, weight gain, and alleviation of symptoms (including constitutional symptoms) in patients with and without JAK2 mutation. These findings were confirmed by two phase III clinical MF studies, in which a greater proportion of ruxolitinib recipients achieved a spleen volume reduction of ≥35% from baseline at week 24, compared with placebo in one study (41.9% versus 0.7%; P < 0.0001) and with best available therapy in the other (31.9% versus 0%; P < 0.0001). Alleviation of MF symptoms and improvements in quality of life were also significantly greater in ruxolitinib recipients. Overall survival of patients treated with ruxolitinib was significantly longer than of those receiving the placebo. Owing to risks of potentially serious adverse effects, eg, myelosuppression, ruxolitinib should be used under close physician supervision. Longer follow-up of the phase III MF studies is needed to reach firm conclusions regarding ruxolitinib’s capacity to modify the natural disease course

Efficacy of HUMN criteria for scoring the micronucleus assay in human lymphocytes exposed to a low concentration of p, p, -DDT

The cytokinesis-block micronucleus (CBMN) assay is one of the standard cytogenetic tools employed to assess chromosomal damage subsequent to exposure to genotoxic/cytotoxic agents, and is widely applicable to plant, animal and human cells. In the present study, the CBMN assay was used to assess the baseline damage in binuclear human peripheral blood lymphocytes exposed to 25 microg/L p, p'-DDT for 1, 2, 24, and 48 h by measuring the frequency of micronuclei, nucleoplasmic bridges and nuclear buds. These new scoring criteria facilitated the detection of different types of clastogenic and aneugenic effects induced by this type of pollutant. With these criteria, CBMN can also be used to measure nucleoplasmic bridges which are considered to be consequences of chromosome rearrangements and nuclear buds which are biomarkers of altered gene amplification and gene dosage. The total number of micronuclei observed in binuclear human peripheral blood lymphocytes of the exposed samples (ranging from 32 to 47) was significantly greater (P < 0.05) than that detected in the unexposed (0 time) control sample, where the total number of micronuclei was 7. The number of nucleoplasmic bridges and nuclear buds obtained after 24 and 48 h was also significantly (P < 0.05) greater in the samples treated with p, p'-DDT than in the unexposed control samples. Thus, our results confirmed the usefulness of the new criteria applicable for the CBMN assay employed in measuring the DNA damage and its role of a sensitive cytogenetic biomarker

Procjena citogenetičkih oštećenja u medicinskog osoblja profesionalno izloženog niskim dozama ionizirajućeg zračenja na odjelima nuklearne medicine

The aim of this study was to provide data on genetic hazards associated with occupational exposure to low doses of ionising radiation in nuclear medicine departments. The DNA damage in peripheral blood lymphocytes of medical staff was assessed using the chromosome aberration test. Altogether 120 subjects (60 exposed and 60 controls) participated in the study. The exposed subjects showed significantly higher frequencies of chromosome aberrations than controls. Significant inter-individual differences in DNA damage within the exposed population indicate different genome sensitivity. Age and sex were not confounding factors, while smoking increased DNA damage only in control subjects. This study suggests that chronic exposure to low doses of ionising radiation in nuclear medicine departments causes cytogenetic damage. For this reason, exposed medical personnel should minimise radiation exposure wherever possible. Our results also point to the significance of biological indicators, which provide information about the actual risk for the radiation-exposed individuals.Ionizirajuće zračenje izaziva različita oštećenja u živim stanicama, čija je pojava ovisna o dozi kojoj su stanice izložene, apsorbiranoj dozi, trajanju izloženosti te osjetljivosti tkiva. Osoblje profesionalno izloženo zračenju pod povećanim je rizikom od štetnih učinaka ionizirajućeg zračenja samo u slučajevima nepoštivanja propisa sigurnosti pri radu. Dugogodišnja profesionalna izloženost zračenju za posljedicu može imati zloćudne bolesti (rak) i genske mutacije. Unatoč intenzivnim istraživanjima, genetska oštećenja proizašla iz izloženosti osoblja ionizirajućem zračenju još nisu potpuno razjašnjena, a posebice ona proizašla iz izloženosti niskim dozama. Cilj ovog istraživanja bio je proučiti genetska oštećenja nastala pod utjecajem profesionalne izloženosti niskim dozama ionizirajućeg zračenja u osoblja zaposlenog na odjelima nuklearne medicine. Procjena oštećenja DNA u limfocitima periferne krvi izloženoga medicinskog osoblja provedena je s pomoću testa analize kromosomskih aberacija. Istraživanje je obuhvatilo ukupno 120 ispitanika (60 izloženih i 60 kontrolnih). U izloženih ispitanika utvrđena je statistički značajno povišena učestalost kromosomskih aberacija u usporedbi s kontrolnom skupinom. Unutar izložene skupine uočene su i značajne interindividualne razlike u razini oštećenja DNA, koje upućuju na različitu genetsku osjetljivost. Dob i spol ispitanika nisu značajnije utjecali na razinu oštećenja genoma, a navika pušenja utjecala je na porast razine oštećenja DNA samo u ispitanika kontrolne skupine. Na osnovi dobivenih rezultata vidljivo je da kronična profesionalna izloženost niskim dozama ionizirajućeg zračenja na odjelima nuklearne medicine izaziva genotoksična oštećenja u limfocitima periferne krvi medicinskog osoblja. Kako bi se izbjegli potencijalni genotoksični učinci, izloženost medicinskog osoblja, kad god je to moguće, treba smanjiti na najmanju moguću razinu. Dobiveni rezultati također naglašavaju važnost primjene bioloških indikatora koji pružaju niz informacija o stvarnom i trenutačnom riziku za izložene ispitanike koji se ne mogu dobiti iz fizikalne dozimetrije

Glucose transporters in the mammalian blood cells

Glucose is the main source of metabolic energy for various cellular functions, and thus plays a central role in supporting intermediary metabolism and cellular homeostasis. Since plasma membrane is impermeable to glucose, its cellular uptake is mediated by two distinct processes via specific glucose transporter proteins that belong to the family of solute carriers (SLC); the SLC2 family members, GLUTs (glucose transporters), are sodium-independent facilitators of the glucose transport, whereas the SLC5 family members, SGLTs (sodium and glucose transporters) mediate the secondary-active sodium- glucose cotransport. Until now, 14 GLUTs and 12 SGLTs isoforms have been identified in humans of which 5 GLUTs and none SGLTs were detected in the mammalian blood cells. Detailed physiological function, precise mechanism of transport, substrates affinity, exact three-dimensional structures, and a precise tissue distribution of most GLUTs in various mammalian organs, including blood, have been poorly explored. In this review we will focus on GLUTs in the mammalian blood cells, where the data on their expression and functional roles are contradictory or largely missing. Since many GLUTs are associated with diabetes, and are up-regulated in cancers, it is undoubtedly important to further investigate GLUTs expression in different organs/tissues, including the blood cells. Understanding the complexity of glucose homeostasis that includes knowledge about tissue distribution and function of GLUTs, as well as the signaling pathways that regulate glucose metabolism, may help to develop new therapeutic strategies to target specific diseases, such as diabetes mellitus, some autoimmunity diseases, and cancer