Changing Pre-school Children's Conceptions of the Day/Night Cycle Changer les Conceptions d'Enfants d'Age Prescolaire sur le Phenomene du Cercle 'Jour-Nuit' Cambiar las Concepciones de los Ninos Preescolares en el Ciclo Dia/Noche     

N. Valanides  F. Gritsi  M. Kampeza  K. Ravanis 《International Journal of Early Years Education》2000,8(1):27-39

A semi-structured interview was individually administered to 33 children aged 5-6. The interview raised questions about the shapes of the Sun and the Earth as well as the cause of the day/night cycle. A teaching intervention designed to teach pre-school age children these concepts was then implemented with groups of 6-7 children. The intervention's effectiveness was consequently evaluated (after 2 weeks) using an interview similar to that conducted prior to the intervention. The results of the study showed that the majority of children readily accepted certain aspects of the scientific explanations of the day/night cycle. Specifically, the majority accepted that the Sun and the Earth are separate spherical objects, but fewer children attributed the day/night cycle to rotation of the Earth on its axis. Most seemed puzzled by the simultaneous movements of the Earth around the Sun and around its axis. Educational and research implications are discussed. Une semi-directive interview individuelle etait administree a 33 enfants de 5 a 6 ans. L'interview contenait des questions sur le scheme du soleil et de la terre et aussi sur la cause du cercle 'jour-nuit'. Une intervention didactique etait apres introduite aux groups de 6-7 enfants et ses resultats etaient finalement evalues, en utilisant la meme interview, deux semaines apres l'intervention. Les resultats de cet etude montrent que la majorite d'enfants ont accepte certains aspects des points de vue scientifiques concernant le cercle 'jour-nuit'. Plus specifiquement, la plupart d'enfants ont accepte que les schemes du soleil et de la terre ressemblaient a une sphere, mais moins d'enfants ont attribue le cercle 'jour-nuit' a la rotation de la terre autour du soi-meme. Quelques enfants n'ont pas developpe les correctes conceptions et c'etait apparent qu'ils avaient des difficultes a comprendre les mouvements simultanes de la terre autour du soleil et du soi-meme. Se administro individualmente una entrevista semiestructurada a 33 ninos de edades comprendidas entre los 5 y 6 anos. La entrevista incluja cuestiones sobre formas del sol y de la tierra y tambien la causa del ciclo dia/noche. Luego se introdujo una intervencion didactica a grupos de 6-7 ninos de edad preescolar para ensenarles estos conceptos. La efectividad de la intervencion file evaluada 2 semanas mas tarde, con una entrevista parecida a la realizada antes de la intervencion. Los resultados del estudjo mostraron que la mayoria de los ninos aceptaban facilmente ciertos aspectos de las explicaciones cientificas del ciclo dia/noche. Mas especialmente, la mayoria aceptaba que el sol y la tierra eran objetos esfericos diferentes, pero menos ninos atribuian el hecho de que el ciclo dia/noche se relacionara con la rotacion de la tierra alrededor de sil eje. Muchos parecian sorprenderse con los movimientos simultaneos de la tierra alrededor del sol y alrededor de si misma. Se discuten las implicaciones educativas y de investigacion.  相似文献   

Detection of tubercular antibody and antigen in sera of bone and joint tuberculosis     

J. Pramanik  A. N. Lodam  C. M. Badole  M. V. R. Reddy  K. R. Patond  B. C. Harinath 《Indian journal of clinical biochemistry : IJCB》2000,15(1):22-28

Trichloroacetic acid (TCA) solubilized and DEAE fractionatedMycobacterium tuberculosis H₃₇Ra excretory-secretory (ES) antigen viz., Mtb EST DE1 and affinity purified goat antibodies to the TCA solubilized ES antigen (Mtb EST) were explored in detecting tubercular antibody and antigen respectively in sera of bone and joint tuberculosis by indirect and sandwich ELISA. Out of total 36 bone & joint tuberculosis cases, tubercular antibody was detected by indirect ELISA in 30 patients (sensitivity 83%), while circulating tubercular antigen was detected by sandwich ELISA in 27 patients (sensitivity 75%). Out of 34 non tubercular disease control cases, 10 patients showed positive reaction for antibody while only 4 patients showed positive reaction for antigen. In another group of 34 healthy subjects who were screened, 4 individuals showed positive reaction for tubercular antibody and 2 cases for antigen. This study shows that antigen detection assay using affinity purified anti Mtb EST antigen antibody is superior with overall specificity of 91% as compared to antibody detection assay with 75% specificity in bone & joint tuberculosis.  相似文献   

Molecular biology and immunology of fungal allergens     

Viswanath P. Kurup  Banani Banerjee  Kevin J. Kelly  Jordan N. Fink 《Indian journal of clinical biochemistry : IJCB》2000,15(1):31-42

Fungi are non-chlorophyllus microorganisms, which constitutes the main source of outdoor and indoor allergens. The antigens present in the spores and fragments of hyphae induce allergic responses in sensitized patients. The frequently recognized fungi associated with asthma include Alternaria, Cladosporium, Aspergillus, and Penicillium. With the advent of molecular biology techniques a number of fungal genes encoding relevant allergens have been cloned and the expressed allergens purified and characterized. In this review, we have presented the recent developments, where recombinant allergens have been used in the precise diagnosis of fungal allergy. We have also discussed the role played by these allergens and the T- and B-cell epitopes in the immune mechanism in fungal allergy.  相似文献   

New age adjuvants and delivery systems for subunit vaccines     

Sridevi Kurella  Monika Manocha  Leenu Sabhnani  Beena Thomas  D. N. Rao 《Indian journal of clinical biochemistry : IJCB》2000,15(1):83-100

The dramatic advancements in the field of vaccinology has led to the formulation of chemically well defined vaccines composed of synthetic peptides and recombinant proteins derived from the immunologically dominant regions of the pathogens. Though these subunit vaccines are safer compared to the traditional vaccines they are known to be poorly immunogenic. This necessitates the use of adjuvants to enhance the immunogenicity of these vaccine formulations. The most common adjuvant for human use is alum. Research in the past has focused on the development of systemic immunity using conventional immunization protocols. In the present are, the emphasis is on the development and formulation of alternative adjuvants and delivery systems in generating systemic as well as mucosal immunity. This review mainly focuses on a variety of adjuvants (particulate as well as non-particulate) used with protective antigens of HIV, malaria, plague, leprosy using modified delivery vehicles. The experience of our laboratory and other researchers in this field clearly proves that these new age adjuvants and delivery systems undoubtedly generate enhanced immune response-both humoral and cell mediated. The choice of antigens, the nature of adjuvant used and the mode of delivery employed have a profound effect on the type of immune response generated. Besides the quantity, the quality of the antibodies generated also play a vital role in protection against these diseases. Some of the adjuvants and delivery systems used promoted high titre and affinity antibodies, which were shown to be cytophilic in nature, an important criteria in providing protection to the host. Thus the studies on these adjuvants/delivery systems with respect to various infectious diseases indicate their active role in efficient modulation of immune response along with safety and permissibility.  相似文献   

A test strip for the estimation of urea in serum     

Hemant Kumar  Ashok Kumar  Poonam Kumari  N. B. Tulsani 《Indian journal of clinical biochemistry : IJCB》2000,15(2):124-127

We have developed a biostrip for determination of urea in serum. The test strip is based on enzymatic assay where urease has been immobilized on the chromatographic paper along with chromogen, phenol red. The chromogen is easily soluble in water and does not require other components for the color change. Serum urea reacts with urease and water to liberate ammonia and carbon dioxide. The liberated ammonia changes the pH of the reaction medium, which is monitored by the chromogen phenol red. A single step working reagent strip has been developed and the reaction is completed within 50 seconds at room temperature. With this test strip urea concentration is measured in serum as low as 0.15 g/L. The speed and convenience of determining urea in serum by this strip instantly makes it well suited for individuals, physicians and emergency centres.  相似文献   

Assessment of oxidative stress and effect of antioxidant supplementation during radiotherapy in carcinoma of upper digestive tract     

Soma Gupta  K. K. Singh  V. J. Vyas  V. N. Chaturvedi  M. V. R. Reddy  B. C. Harinath 《Indian journal of clinical biochemistry : IJCB》2000,15(1):52-55

Oxidative stress was studied by estimating plasma levels of malondialdehyde (MDA), beta carotene, vitamin E and erythrocytic superoxide dismutase(E-SOD) activity in 50 cases of carcinoma of upper digestive tract which included carcinoma of oral cavity, pharynx and oesophagus. While plasma MDA level was found to be increased (3.5±1.0 nmole/ml), a significant decrease in beta carotene (81.2±14.5mg%), vitamin E (8.5±1.1 mg/L) level and E-SOD activity (657.0±80.6 U/G Hb) were observed in carcinoma of upper digestive tract. Patients were treated with radiotherapy which itself was toxic enough and produced its deleterious effects by generation of reactive oxygen species (ROS). As antioxdiants can detoxify ROS, beneficial effect if any, of antioxidant administration during radiotherapy was studied in two groups of patients, group A (n=5, supplemented with antioxidants) and group B (n=5, without antioxidant supplementation). Plasma MDA level was found to be elevated in both the groups but the increase in group B was significant, compared to pretreatment level. Further, body weight was found to be significantly decreased in group B patients, which was maintained in group A patients. Moreover, group A patients showed significant elevation in beta carotene concentration, thus showing beneficial effect of administration of antioxidants during radiotherapy without disturbing the desirable therapeutic effect of radiotherapy.  相似文献   

Philosophical foundations of quantum field theory   总被引：1，自引：0，他引：1  

Huggett  N 《The British journal for the philosophy of science》2000,51(4):617-637

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Information and its value to health workers in rural Uganda: a qualitative perspective*     

Maria G. N. Musoke 《Health information and libraries journal》2000,17(4):194-202

A study was conducted in 1998/99 to investigate the accessibility and use of information by health workers in rural Uganda. Data were collected qualitatively using semi‐structured interviews. As a qualitative study, it focused in‐depth on a relatively small sample of health workers selected purposefully. Different categories of health workers were interviewed. Data were analysed using a grounded theory approach. In this paper, two main categories that emerged from the data will be discussed, namely: value of information and constraints. Information was valuable in clinical work, information dissemination, decision making, administration and detection. Constraints to effective information use included the quality and relevance of the information as well as the difficulties of sometimes putting theory into practice. Finally, the concepts that emerged from the analysis of the use of information pointed directly to the information needs of the health workers studied, which shows that information was valuable in meeting those needs. Some implications of the study and areas for further research are highlighted.  相似文献   

The angiogenetic effect of intramuscular administration of b-FGF and a-FGF on cardiac muscle: the influence of exercise on muscle angiogenesis     

Efthimiadou A  Asimakopoulos B  Nikolettos N  Giatromanolaki A  Sivridis E  Lialiaris TS  Papachristou DN  Kontoleon E 《Journal of sports sciences》2006,24(8):849-854

Although angiogenetic therapy using recombinant growth factors holds much hope for the treatment of ischaemic diseases, there are still many unanswered questions, including the method of administration, the correct dose of these factors, and the duration of the therapeutic approach. Exercise has also been suggested to induce neovascularizaiton in muscles. We evaluated the angiogenetic effects of the intramuscular administration of basic-fibroblast growth factor (b-FGF) and acidic-fibroblast growth factor (a-FGF) in rat heart, compared with rats who exercised daily. In conclusion, both the intramuscular administration of b-FGF and exercise increased significantly angiogenesis in the heart in contrast to the intramuscular administration of a-FGF, which was ineffective.  相似文献   

Space victualling     

N.W Pirie 《Endeavour》1980,4(2):74-77

Victualling in space differs fundamentally from victualling on land or at sea because there is little chance of foraging or of finding local sources of oxygen and water, and all metabolic products have to be carefully collected even if they will ultimately be jettisoned. The need for a deliberate policy for coping with carbon dioxide, faeces, and urine leads naturally, to schemes for recycling. Entropy is increased when food is metabolised: energy will have to be expended for even partial restoration of the status quo.  相似文献