A family resemblance approach to the nature of science for science education

Although there is universal consensus both in the science education literature and in the science standards documents to the effect that students should learn not only the content of science but also its nature, there is little agreement about what that nature is. This led many science educators to adopt what is sometimes called “the consensus view” about the nature of science (NOS), whose goal is to teach students only those characteristics of science on which there is wide consensus. This is an attractive view, but it has some shortcomings and weaknesses. In this article we present and defend an alternative approach based on the notion of family resemblance. We argue that the family resemblance approach is superior to the consensus view in several ways, which we discuss in some detail

Povezanost protočne citometrije s drugim kliničkim i patohistološkim parametrima u bolesnica s neuroendokrinim duktalnim karcinomom dojke

Aims. The aim of the study was to determine cellular ploidy of invasive ductal breast carcinoma with neuroendocrine (NE) differentiation and its share in certain phases of the cell cycle. It was also aimed at assessing the relationship of the cell cycle profile with other clinical and histopathological features. Methods. The study was carried out in 80 patients with invasive ductal breast cancer, and classified as breast carcinoma with NE differentiation according to their histopathological parameters. The patients underwent treatment at the University Hospital for Tumors, Zagreb, Croatia during the period January 1 to December 31, 1992. Data about patients’ age, estrogen and progesterone receptor concentration, cancer size, and treatment modality were retrospectively collected from their case histories. Paraffin blocks were used for immunohistochemical and histochemical analysis and flow cytometric analysis of the tumor cell cycle. Neuroendocrine tumor diagnosis was made using Grimelius and immunohistochemical staining including neuron-specific enolase (NSE), chromogranin A and synaptophysin. Results. Analysis by flow cytometry detected 27 tumors (33.8%) with DNA diploidy showing proliferative activity lower than 20%, and 53 tumors (66.2%) with DNA aneuploidy, tetraploidy and/or DNA diploidy with proliferative activity over 20%. Progesterone receptor concentration in DNA-diploid tumors was significantly higher that in DNA-aneuploid, tetraploid tumors and tumors with proliferative activity of ≥20% (p<0.001). Concentration of estrogen receptors, age, histological grade, tumor size, Grimelius staining and immnohistochemical markers did not significantly differ between the groups. Conclusion. Data collected in our study show a higher mean concentration of progesterone receptors in the group of diploid tumors and tumors with low proliferative activity. In consideration with the above criterium, other pathological and clinical parameters did not show any significant difference relative to both tumor ploidy and its proliferative activity. For final conclusion on the clinical significance of neuroendocrine differentiation in breast cancer further studies that would include monitoring of the course and outcome of the disease are required.Ciljevi. Cilj našeg istraživanja bio je odrediti ploidnost stanica kod invazivnih duktalnih karcinoma dojke s neuroendokrinom (NE) diferencijacijom i njihov udio u pojedinim fazama staničnog ciklusa. Također se htjelo utvrditi povezanost profila staničnog ciklusa s drugim kliničkim i patohistološkim značajkama. Metode. Istraživanje je provedeno na 80 bolesnica s duktalnim invazivnim karcinomom dojke koji su prema patohistološkim parametrima svrstani u karcinome dojke s NE diferencijacijom. Bolesnice su liječene u razdoblju od 01.01. do 31.12.1992. godine na Klinici za tumore u Zagrebu. Podaci o dobi bolesnica, koncentraciji estrogenskih i progesteronskih receptora, veličini karcinoma, te načinu liječenja dobiveni su retrospektivno iz povijesti bolesti. Parafinski blokovi upotrijebljeni su za imunohistokemijsku i histokemijsku analizu te analizu staničnog ciklusa tumorskih stanica protočnom citometrijom. Dijagnoze neuroendokrinih tumora postavljene su na temelju bojenja po Grimeliusu te imunohistokemijskih bojenja uključujući neuron-specifičnu enolazu (NSE), kromogranin A i sinaptofizin. Rezultati. Protočnom citometrijom kod 27 tumora (33.8%) nađena je DNA diploidija i visina proliferativne aktivnosti manja od 20%, dok su DNA aneuploidija, tetraploidija i/ili DNA diploidija s proliferativnom aktivnošću većom od 20% nađene kod 53 tumora (66.2%). Koncentracija progesteronskih receptora u DNA-diploidnim tumorima bila je značajno viša nego kod DNA-aneuploidnih, tetraploidnih i tumora s proliferativnom aktivnošću ≥20% tumora (p<0.001). Koncentracija estrogenskih receptora, dob, histološki stupanj, veličina tumora, bojanje po Grimeliusu te imunohistokemijski markeri nisu se značajno razlikovali u ove dvije skupine. Zaključak. Podaci iz našeg istraživanja upućuju na veću prosječnu koncentraciju progesteronskih receptora u skupini diploidnih tumora i tumora s niskom proliferativnom aktivnošću. Prema navedenom kriteriju drugi patološki i klinički parametri nisu pokazali značajnu razliku u odnosu na ploidnost i proliferativnu aktivnost. Za donošenje konačnog zaključka o kliničkoj važnosti neuroendokrine diferencijacije kod karcinoma dojke potrebno je provesti istraživanja koja bi uključila praćenje tijeka i ishoda bolesti

Povezanost protočne citometrije s drugim kliničkim i patohistološkim parametrima u bolesnica s neuroendokrinim duktalnim karcinomom dojke

Aims. The aim of the study was to determine cellular ploidy of invasive ductal breast carcinoma with neuroendocrine (NE) differentiation and its share in certain phases of the cell cycle. It was also aimed at assessing the relationship of the cell cycle profile with other clinical and histopathological features. Methods. The study was carried out in 80 patients with invasive ductal breast cancer, and classified as breast carcinoma with NE differentiation according to their histopathological parameters. The patients underwent treatment at the University Hospital for Tumors, Zagreb, Croatia during the period January 1 to December 31, 1992. Data about patients’ age, estrogen and progesterone receptor concentration, cancer size, and treatment modality were retrospectively collected from their case histories. Paraffin blocks were used for immunohistochemical and histochemical analysis and flow cytometric analysis of the tumor cell cycle. Neuroendocrine tumor diagnosis was made using Grimelius and immunohistochemical staining including neuron-specific enolase (NSE), chromogranin A and synaptophysin. Results. Analysis by flow cytometry detected 27 tumors (33.8%) with DNA diploidy showing proliferative activity lower than 20%, and 53 tumors (66.2%) with DNA aneuploidy, tetraploidy and/or DNA diploidy with proliferative activity over 20%. Progesterone receptor concentration in DNA-diploid tumors was significantly higher that in DNA-aneuploid, tetraploid tumors and tumors with proliferative activity of ≥20% (p<0.001). Concentration of estrogen receptors, age, histological grade, tumor size, Grimelius staining and immnohistochemical markers did not significantly differ between the groups. Conclusion. Data collected in our study show a higher mean concentration of progesterone receptors in the group of diploid tumors and tumors with low proliferative activity. In consideration with the above criterium, other pathological and clinical parameters did not show any significant difference relative to both tumor ploidy and its proliferative activity. For final conclusion on the clinical significance of neuroendocrine differentiation in breast cancer further studies that would include monitoring of the course and outcome of the disease are required.Ciljevi. Cilj našeg istraživanja bio je odrediti ploidnost stanica kod invazivnih duktalnih karcinoma dojke s neuroendokrinom (NE) diferencijacijom i njihov udio u pojedinim fazama staničnog ciklusa. Također se htjelo utvrditi povezanost profila staničnog ciklusa s drugim kliničkim i patohistološkim značajkama. Metode. Istraživanje je provedeno na 80 bolesnica s duktalnim invazivnim karcinomom dojke koji su prema patohistološkim parametrima svrstani u karcinome dojke s NE diferencijacijom. Bolesnice su liječene u razdoblju od 01.01. do 31.12.1992. godine na Klinici za tumore u Zagrebu. Podaci o dobi bolesnica, koncentraciji estrogenskih i progesteronskih receptora, veličini karcinoma, te načinu liječenja dobiveni su retrospektivno iz povijesti bolesti. Parafinski blokovi upotrijebljeni su za imunohistokemijsku i histokemijsku analizu te analizu staničnog ciklusa tumorskih stanica protočnom citometrijom. Dijagnoze neuroendokrinih tumora postavljene su na temelju bojenja po Grimeliusu te imunohistokemijskih bojenja uključujući neuron-specifičnu enolazu (NSE), kromogranin A i sinaptofizin. Rezultati. Protočnom citometrijom kod 27 tumora (33.8%) nađena je DNA diploidija i visina proliferativne aktivnosti manja od 20%, dok su DNA aneuploidija, tetraploidija i/ili DNA diploidija s proliferativnom aktivnošću većom od 20% nađene kod 53 tumora (66.2%). Koncentracija progesteronskih receptora u DNA-diploidnim tumorima bila je značajno viša nego kod DNA-aneuploidnih, tetraploidnih i tumora s proliferativnom aktivnošću ≥20% tumora (p<0.001). Koncentracija estrogenskih receptora, dob, histološki stupanj, veličina tumora, bojanje po Grimeliusu te imunohistokemijski markeri nisu se značajno razlikovali u ove dvije skupine. Zaključak. Podaci iz našeg istraživanja upućuju na veću prosječnu koncentraciju progesteronskih receptora u skupini diploidnih tumora i tumora s niskom proliferativnom aktivnošću. Prema navedenom kriteriju drugi patološki i klinički parametri nisu pokazali značajnu razliku u odnosu na ploidnost i proliferativnu aktivnost. Za donošenje konačnog zaključka o kliničkoj važnosti neuroendokrine diferencijacije kod karcinoma dojke potrebno je provesti istraživanja koja bi uključila praćenje tijeka i ishoda bolesti

Pubertal timing and breast density in young women: a prospective cohort study.

BACKGROUND:Earlier age at onset of pubertal events and longer intervals between them (tempo) have been associated with increased breast cancer risk. It is unknown whether the timing and tempo of puberty are associated with adult breast density, which could mediate the increased risk. METHODS:From 1988 to 1997, girls participating in the Dietary Intervention Study in Children (DISC) were clinically assessed annually between ages 8 and 17 years for Tanner stages of breast development (thelarche) and pubic hair (pubarche), and onset of menses (menarche) was self-reported. In 2006-2008, 182 participants then aged 25-29 years had their percent dense breast volume (%DBV) measured by magnetic resonance imaging. Multivariable, linear mixed-effects regression models adjusted for reproductive factors, demographics, and body size were used to evaluate associations of age and tempo of puberty events with %DBV. RESULTS:The mean (standard deviation) and range of %DBV were 27.6 (20.5) and 0.2-86.1. Age at thelarche was negatively associated with %DBV (p trend = 0.04), while pubertal tempo between thelarche and menarche was positively associated with %DBV (p trend = 0.007). %DBV was 40% higher in women whose thelarche-to-menarche tempo was 2.9 years or longer (geometric mean (95%CI) = 21.8% (18.2-26.2%)) compared to women whose thelarche-to-menarche tempo was less than 1.6 years (geometric mean (95%CI) = 15.6% (13.9-17.5%)). CONCLUSIONS:Our results suggest that a slower pubertal tempo, i.e., greater number of months between thelarche and menarche, is associated with higher percent breast density in young women. Future research should examine whether breast density mediates the association between slower tempo and increased breast cancer risk

Physical Activity Research in Nursing

Purpose: To present exemplars of physical activity research in nursing, illustrate the importance of physical activity research across the lifespan, and recommend directions for theory development and research. Methods: Studies of physical activity and exercise currently being conducted by nurse investigators were reported and critiqued by attendees of the Midwest Nursing Research Society 2000 Preconference session entitled “Promoting Physical Activity Among Diverse Groups Across the Health Continuum.” Physical activity and exercise literature during the past decade was reviewed. Databases searched included Medline, CINAHL, Wilson, and ERIC. Findings: Investigators have emphasized the need to evaluate the effects of theory-based physical activity interventions designed to alter key correlates of physical activity identified through descriptive research. Conclusions: Regular physical activity is necessary for health promotion and disease prevention for all populations. Continued research in this important area of health behavior is critical to identify the most effective interventions to increase physical activity among diverse populations

Assessment of the effects of sulfate and nitrate on the temporal evolution of Klebsiella oxytoca and Staphylococcus aureus abundance under shaking conditions, in aquatic microcosm

Most chemicals in natural aquatic media can be assimilated by bacteria. The impact of various environmental conditions on this microbial process is not always clear. This study aimed at investigating changes in the abundance of Klebsiella oxytoca and Staphylococcus aureus under different shaking conditions, in aquatic microcosms containing nitrate and sulfate. Sodium chloride solution (8.5 g NaCl•L-1), and nitrate and sulfate solutions (0.005, 0.05, 0.5 and 5 g•L-1) containing bacteria were supplemented with tryptic peptone at a final concentration of 10 g•L-1. The solutions were incubated under shaking conditions (300, 350 and 400 rev•min-1). Bacteriological analyses were performed hourly over a 6-h period. During the first 3 h of incubation, results showed that the highest values of the apparent cell growth rates (CAGRs) with K2SO4 in pure cultures, at a shaking speed 400 rev•min-1, were 0.656 h-1 for S. aureus, and 0.364 h-1 for K. oxytoca. In mixed culture, the CAGR was 0.235 h-1 for S. aureus, and 0.388 h-1 for K. oxytoca, both recorded at 300 rev•min-1. With KNO3 in pure culture solutions, the CAGR was 0.353 h-1 for S. aureus at 300 rev•min-1, and 0.367 h-1 for K. oxytoca at 350 rev•min-1. In mixed culture it was 0.454 h-1 for S. aureus and 0.393 h-1 for K. oxytoca, both recorded at 350 rev•min-1. The highest value of the apparent cell inhibition rate (CAIR) for S. aureus was 0.520 h-1 in K2SO4 (5 g•L-1, 400 rev•min-1), and 0.115 h-1 in KNO3 (5 g•L-1, 300 rev•min-1). For K. oxytoca, it was 0.07 h-1 in K2SO4 in pure culture (0.05 g•L-1, 300 rev•min-1), and 0.044 h-1 in mixed culture (0.05 g•L-1, 350 rev•min-1). In KNO3 it was 0.239 h-1 in mixed culture (5 g•L-1, 300 rev•min-1). The growth and inhibition potentials of different microbial species were impacted by the chemical concentrations and the movement speeds.L’impact de diverses conditions environnementales sur l’assimilation bactérienne dans l’eau, des composés chimiques est peu connu. La présente étude a visé l’évaluation de la dynamique d’abondance de Klebsiella oxytoca et Staphylococcus aureus sous diverses conditions, en milieu aquatique microcosme contenant du sulfate ou nitrate. Des solutions du NaCl (8,5 g•L-1), sulfate et nitrate (0,005, 0,05, 0,5 et 5 g•L-1) contenant des cellules ont été enrichies à la peptone trypsique (concentration finale 10 g•L-1), puis incubées sous conditions dynamiques (300, 350 et 400 tr•min-1). Les analyses bactériologiques ont été effectuées pendant 6 h. Il ressort qu’au cours des trois premières heures d'incubation, le taux de croissance cellulaire apparent (TCCA) le plus élevé en culture pure, contenant du K2SO4, est de 0,656 h-1 pour S. aureus, et 0,364 h-1 pour K. oxytoca, enregistrés à 400 tr•min-1. En culture mixte, il est de 0,235 h-1 pour S. aureus, et 0,388 h-1 pour K. oxytoca, enregistrés à 300 tr•min-1. Avec du KNO3, en culture pure, le TCCA est de 0,353 h-1 pour S. aureus à 300 tr•min-1, et 0,367 h-1 à 350 tr•min-1 pour K. oxytoka. En culture mixte, il est de 0,454 h-1 pour S. aureus et 0,393 h-1 pour K. oxytoca, enregistrés à 350 tr•min-1. Le taux d’inhibition cellulaire apparent (TICA) le plus élevé de S. aureus est de 0,520 h-1 en présence du K2SO4 (5 g•L-1, 400 tr•min-1), et 0,115 h-1 en présence de KNO3 (5 g•L-1, 300 tr•min-1). Pour K. oxytoca, il est de 0,07 h-1 avec du K2SO4 en culture pure (0,05 g•L-1, 300 tr•min-1), et 0,044 h-1 en culture mixte (0,05 g•L-1, 350 tr•min-1). Avec du KNO3, il est de 0,239 h-1 en culture mixte (5 g•L-1, 300 tr•min-1). La croissance et l’inhibition des microorganismes sont affectées par les concentrations en sels et la vitesse de mouvements du milieu

Contrasting effects of environmental change factors on the radial growth of co-occurring European beech and fir trees across Europe

Under predicted climate change, silver fir (Abies alba) and European beech (Fagus sylvatica) are the most likely replacement species for the more heat- and drought-sensitive monocultures of Norway spruce (Picea abies) planted across large parts of continental Europe. Our current understanding of the climate-related adaptation potential of fir and beech mixtures is, however, limited. Here we compile and analyse 2855 tree-ring width (TRW) series from 17 mixed beech-fir forest sites in five European countries. Dendroecological techniques that combine various detrending methods with an application of documented environmental change trends reveal wide variation of radial growth between fir and beech across space and time. Coincidental with peak SO2 emissions, the growth of silver fir declined between 1950 and 1980 at most sites, whereas beech growth increased during this period. Correspondent to a significant warming trend from 1990–2010, average beech growth declined, but silver fir growth increased. Our observations of long-term growth trends support the replacement of spruce monocultures with multi-species mixtures that have demonstrated a higher tolerance of environmental changes

Constructivism: Defense or a Continual Critical Appraisal – A Response to Gil-Pérez et al.

Abstract. This commentary is a critical appraisal of Gil-Pérez et al.’s (2002) conceptualization of constructivism. It is argued that the following aspects of their presentation are problematic: (a) Although the role of controversy is recognized, the authors implicitly subscribe to a Kuhnian perspective of ‘normal’ science; (b) Authors fail to recognize the importance of von Glasersfeld’s contribution to the understanding of constructivism in science education; (c) The fact that it is not possible to implement a constructivist pedagogy without a constructivist epistemology has been ignored; and (d) Failure to recognize that the metaphor of the ‘student as a developing scientist’ facilitates teaching strategies as students are confronted with alternative/rival/conflicting ideas. Finally, we have shown that constructivism in science education is going through a process of continual critical appraisals