Learning from erroneous models using SCYDynamics

Dynamic phenomena are common in science education. Students can learn about such system dynamic processes through model based learning activities. This paper describes a study on the effects of a learning from erroneous models approach using the learning environment SCYDynamics. The study compared three conditions. Two experimental conditions where students had to correct errors in a model were contrasted to working with a correct model. The experimental conditions differed on whether or not the students had to detect the errors before correcting them. Results indicate that this approach enhanced students’ model testing and revising activities. Furthermore this approach was found to have a beneficial effect on learning common errors. Contrary to expectations this approach showed no learning effect on domain knowledge acquisition. The discussion further elaborates on improvements that might enhance this learning from erroneous model approac

Finding out how they find it out: an empirical analysis of inquiry learners' need for support

Inquiry learning environments increasingly incorporate modelling facilities for students to articulate their research hypotheses and (acquired) domain knowledge. This study compared performance success and scientific reasoning of university students with high prior knowledge (n=11), students from senior high-school (n=10), and junior high-school (n=10) with intermediate and low prior knowledge respectively, in order to reveal domain novice's need for support in such environments. Results indicated that the scientific reasoning of both groups of high-school students was comparable to that of the experts. As high-school students achieved significantly lower performance success scores, their expert-like behaviour was rather ineffective; qualitative analyses substantiated this conclusion. Based on these findings, implications for supporting domain novices in inquiry learning environments are advanced

Scaffolding learning by modelling: The effects of partially worked-out models

Creating executable computer models is a potentially powerful approach to science learning. Learning by modelling is also challenging because students can easily get overwhelmed by the inherent complexities of the task. This study investigated whether offering partially worked-out models can facilitate students’ modelling practices and promote learning. Partially worked-out models were expected to aid model construction by revealing the overall structure of the model, and thus enabling student to create better models and learn from the experience. This assumption was tested in high school biology classes where students modelled the human glucose-insulin regulatory system. Students either received support in the form of a partial model that outlined the basic structure of the glucose-insulin system (PM condition; n = 26), an extended partial model that also contained a set of variables students could use to complete the model (PM+ condition; n = 21), or no support (control condition; n = 23). Results showed a significant knowledge increase from pretest to posttest in all conditions. Consistent with expectations, knowledge gains were higher in the two partial model conditions than in the control condition. Students in both partial model conditions also ran their model more often to check its accuracy, and eventually built better models than students from the control condition. Comparison between the PM and PM+ conditions showed that more extensive support further increased knowledge acquisition, model quality, and model testing activities. Based on these findings, it was concluded that partial solutions can support learning by modelling, and that offering both a structure of a model and a list of variables yields the best result

Coexpression of Kit and the receptors for erythropoietin, interleukin 6 and GM-CSF on hemopoietic cells

The detection of functional growth factor (GF) receptors on subpopulations of hemopoietic cells may provide a further dissection of immature cell subsets. Since little information is available about coexpression of different GF receptors at the level of single hemopoietic cells, we studied the feasibility of simultaneous cell staining with a combination of biotin- and digoxigenin-labeled GFs for flow cytometric detection of functional receptors. Using this methodology, coexpression of Kit and receptors for erythropoietin (EPO), interleukin 6 (IL-6), and GM-CSF on hemopoietic cells was studied by triple-staining of rhesus monkey bone marrow (BM) cells with labeled GFs and antibodies against other cell surface markers. Most of the immature, CD34+2 cells were Kit+ but did not display detectable levels of EPO-receptors (EPO-Rs) or GM-CSF-R. Approximately 60% of these CD34+2/Kit+ cells coexpressed the IL-6-R, demonstrating that immature cells are heterogeneous with respect to IL-6-R expression. Maturation of monomyeloid progenitors, as demonstrated by decreasing CD34 and increasing CD11b expression, is accompanied by a decline of Kit and an increase in GM-CSF-R expression in such a way that Kit+/GM-CSF-R+ cells are hardly detectable. IL-6-R expression is maintained or even increased during monomyeloid differentiation. IL-6-R and GM-CSF-R were not identified on most CD71+2 cells, which indicated that these receptors are probably not expressed during erythroid differentiation. Together with previous results, our data show that both Kit and CD71 are upregulated with erythroid commitment of immature progenitors. Upon further differentiation, Kit+/EPO-R-cells lose CD34 and acquire EPO-R. Maturing erythroid cells eventually lose CD71 and Kit expression but retain the EPO-R. In conclusion, this approach enables further characterization of the specificity of GFs for different bone marrow subpopulations. Apart from insight into the differentiation stages on which individual GFs may act, information about receptor coexpression may be used to identify individual cells that can respond to multiple GFs, and allows for further characterization of the regulation of lineage-specific differentiation

Enabling Group-Based Learning in Teacher Education: A Case Study of Student Experience

“Teacher education ill prepares pre-service teachers for the classroom.” Research conducted in a teacher education program at Edith Cowan University (ECU) responded to this criticism. This longitudinal case study selected group work (i.e., group-based learning) to investigate the quality of its teacher education program. Phase one explored teacher educators\u27 perceptions of group-based learning. Phase two explored preservice teachers\u27 perceptions and experience of group-based learning. This phase used student ‘voice’ (i.e., through focus groups, confirmed field notes, summary sheets) to convey their ideas and experiences when studying in a group and/or implementing group-based learning in the classroom. This paper discusses phase two findings which show the importance of consistency and coherence in understanding group-based learning principles and practices, and the broad ‘conditions’ and ‘actions’ that enable meaningful learning. The research has enabled ECU teacher educators to enhance the quality of the teacher education program

The validity and utility of violence risk assessment tools to predict patient violence in acute care settings: An integrative literature review

To examine risk assessment tools to predict patient violence in acute care settings. An integrative review of the literature. Five electronic databases – CINAHL Plus, MEDLINE, OVID, PsycINFO, and Web of Science were searched between 2000 and 2018. The reference list of articles was also inspected manually. The PICOS framework was used to refine the inclusion and exclusion of the literature, and the PRISMA statement guided the search strategy to systematically present findings. Forty-one studies were retained for review. Three studies developed or tested tools to measure patient violence in general acute care settings, and two described the primary and secondary development of tools in emergency departments. The remaining studies reported on risk assessment tools that were developed or tested in psychiatric inpatient settings. In total, 16 violence risk assessment tools were identified. Thirteen of them were developed to assess the risk of violence in psychiatric patients. Two of them were found to be accurate and reliable to predict violence in acute psychiatric facilities and have practical utility for general acute care settings. Two assessment tools were developed and administered in general acute care, and one was developed to predict patient violence in emergency departments. There is no single, user-friendly, standardized evidence-based tool available for predicting violence in general acute care hospitals. Some were found to be accurate in assessing violence in psychiatric inpatients and have potential for use in general acute care, require further testing to assess their validity and reliability

Enabling Group-Based Learning in Teacher Education: A Case Study of Student Experience

“Teacher education ill prepares pre-service teachers for the classroom.” Research conducted in a teacher education program at Edith Cowan University (ECU) responded to this criticism. This longitudinal case study selected group work (i.e., group-based learning) to investigate the quality of its teacher education program. Phase one explored teacher educators\u27 perceptions of group-based learning. Phase two explored pre-service teachers\u27 perceptions and experience of group-based learning. This phase used student ‘voice’ (i.e., through focus groups, confirmed field notes, summary sheets) to convey their ideas and experiences when studying in a group and/or implementing group-based learning in the classroom. This paper discusses phase two findings which show the importance of consistency and coherence in understanding group-based learning principles and practices, and the broad ‘conditions’ and ‘actions’ that enable meaningful learning. The research has enabled ECU teacher educators to enhance the quality of the teacher education program

Construction costs, chemical composition and payback time of high- and low-irradiance leaves

The effect of irradiance on leaf construction costs, chemical composition, and on the payback time of leaves was investigated. To enable more generalized conclusions, three different systems were studied: top and the most-shaded leaves of 10 adult tree species in a European mixed forest, top leaves of sub-dominant trees of two evergreen species growing in small gaps or below the canopy in an Amazonian rainforest, and plants of six herbaceous and four woody species grown hydroponically at low or high irradiance in growth cabinets. Daily photon irradiance varied 3-6-fold between low- and high-light leaves. Specific leaf area (SLA) was 30-130% higher at low light. Construction costs, on the other hand, were 1-5% lower for low-irradiance leaves, mainly because low-irradiance leaves had lower concentrations of soluble phenolics. Photosynthetic capacity and respiration, expressed per unit leaf mass, were hardly different for the low- and high-light leaves. Estimates of payback times of the high-irradiance leaves ranged from 2-4 d in the growth cabinets, to 15-20 d for the adult tree species in the European forest. Low-irradiance leaves had payback times that were 2-3 times larger, ranging from 4 d in the growth cabinets to 20-80 d at the most shaded part of the canopy of the mixed forest. In all cases, estimated payback times were less than half the life span of the leaves, suggesting that even at time-integrated irradiances lower than 5% of the total seasonal value, investment in leaves is still fruitful from a carbon-economy point of view. A sensitivity analysis showed that increased SLA of low-irradiance leaves was the main factor constraining payback times. Acclimation in the other five factors determining payback time, namely construction costs, photosynthetic capacity per unit leaf mass, respiration per unit leaf mass, apparent quantum yield, and curvature of the photosynthetic light-response-curve, were unimportant when the observed variation in each factor was examine

Muscle mass, muscle strength and mortality in kidney transplant recipients:results of the TransplantLines Biobank and Cohort Study

Background: Survival of kidney transplant recipients (KTR) is low compared with the general population. Low muscle mass and muscle strength may contribute to lower survival, but practical measures of muscle status suitable for routine care have not been evaluated for their association with long-term survival and their relation with each other in a large cohort of KTR. Methods: Data of outpatient KTR ≥ 1 year post-transplantation, included in the TransplantLines Biobank and Cohort Study (ClinicalTrials.gov Identifier: NCT03272841), were used. Muscle mass was determined as appendicular skeletal muscle mass indexed for height2 (ASMI) through bio-electrical impedance analysis (BIA), and by 24-h urinary creatinine excretion rate indexed for height2 (CERI). Muscle strength was determined by hand grip strength indexed for height2 (HGSI). Secondary analyses were performed using parameters not indexed for height2. Cox proportional hazards models were used to investigate the associations between muscle mass and muscle strength and all-cause mortality, both in univariable and multivariable models with adjustment for potential confounders, including age, sex, body mass index (BMI), estimated glomerular filtration rate (eGFR) and proteinuria. Results: We included 741 KTR (62% male, age 55 ± 13 years, BMI 27.3 ± 4.6 kg/m2), of which 62 (8%) died during a median [interquartile range] follow-up of 3.0 [2.3–5.7] years. Compared with patients who survived, patients who died had similar ASMI (7.0 ± 1.0 vs. 7.0 ± 1.0 kg/m2; P = 0.57), lower CERI (4.2 ± 1.1 vs. 3.5 ± 0.9 mmol/24 h/m2; P &lt; 0.001) and lower HGSI (12.6 ± 3.3 vs. 10.4 ± 2.8 kg/m2; P &lt; 0.001). We observed no association between ASMI and all-cause mortality (HR 0.93 per SD increase; 95% confidence interval [CI] [0.72, 1.19]; P = 0.54), whereas CERI and HGSI were significantly associated with mortality, independent of potential confounders (HR 0.57 per SD increase; 95% CI [0.44, 0.81]; P = 0.002 and HR 0.47 per SD increase; 95% CI [0.33, 0.68]; P &lt; 0.001, respectively), and associations of CERI and HGSI with mortality remained independent of each other (HR 0.68 per SD increase; 95% CI [0.47, 0.98]; P = 0.04 and HR 0.53 per SD increase; 95% CI [0.36, 0.76]; P = 0.001, respectively). Similar associations were found for unindexed parameters. Conclusions: Higher muscle mass assessed by creatinine excretion rate and higher muscle strength assessed by hand grip strength are complementary in their association with lower risk of all-cause mortality in KTR. Muscle mass assessed by BIA is not associated with mortality. Routine assessment using both 24-h urine samples and hand grip strength is recommended, to potentially target interdisciplinary interventions for KTR at risk for poor survival to improve muscle status.</p

Virilization Due to Androgen Hypersecretion in a Patient with Ovarian Leydig Cell Tumor: Diagnostic and Psychosocial Implications

Virilisasi akibat kelebihan hormon androgen yang terjadi pada wanita akan menimbulkan tanda-tanda seperti pembesaran klitoris, perubahan suara, tumbuhnya rambut di wajah dan tubuh yang menjadi ciri khas laki-laki. Virilisasi yang disebabkan oleh tumor ovarium tidak lebih dari 0,5% dari seluruh penyebab. Kami melaporkan kasus virilisasi akibat tumor sel Leydig pada ovarium kiri wanita usia 36 tahun. Kesalahan interpretasi, informasi medis yang saling bertentangan dan saran dari dokter sebelumnya membuat kebingungan dari pasien tersebut. Kami melakukan evaluasi diagnostik yang meliputi gambaran klinik, hormon, pencitraan, pemeriksaan patologi, molekuler serta pemeriksaan psikologi. Pemeriksaan hormon menunjukkan kadar testosteron yang sangat tinggi. Adanya tumor pada ovarium terdeteksi dari pemeriksaan laparoskopi. Biopsi pada ovarium kiri dilakukan oleh karena pasien menolak dilakukan pengangkatan ovarium. Hasil pemeriksaan patologi menunjukkan tumor sel Leydig tanpa adanya tanda keganasan. Pengelolaan menjadi kurang optimal karena faktor sosial budaya yang menghambat walaupun telah dilakukan konseling secara mendalam. Tumor sel Leydig pada ovarium dicurigai apabila terjadi virilisasi pada wanita usia reproduktif disertai peningkatan hormon androgen, massa ovarium pada pemeriksaan pencitraan dan dibuktikan dengan hasil biopsi. Hal ini penting sebelum memberikan saran maupun pengobatan kepada pasien. Kata kunci: diagnostik work up, virilisasi, sel tumor Leydig. ABSTRACT Virilization due to hyperandrogenism in women causes male signs and symptoms such as swelling of the clitoris, deepening of the voice, facial hair and increase in body hair. Virilization is caused by less than 0.5% of all ovarian tumors. Here we report a case of virilizing Leydig cell tumor of the left ovary in a 36 year old woman. Misinterpretation of symptoms, conflicting medical information and advice from previous doctors had confused the patient. We performed a diagnostic evaluation including clinical, hormonal parameters, imaging, anatomical pathology examinations, and psychological assessment. Blood analysis showed a high testosterone level. The presence of an ovarian tumor was confirmed by laparoscopy. Since the patient refused ovariectomy, a biopsy of the left ovary was performed. Pathology showed a Leydig cell tumor without histological signs of malignancy. In spite of extensive explanation and psychological counseling, cultural barriers prevented appropriate treatment. An ovarian Leydig cell tumor should always be considered for a woman in the reproductive age with symptoms of virilization. The diagnosis is suspected on the basis of an ovarian mass on examination and further investigation and should be proven by biopsy. Key words: diagnostic work up, virilization, Leydig cell tumor