The role of unit evaluation, learning and culture dimensions related to student cognitive style in hypermedia learning

Recent developments in learning technologies such as hypermedia are\ud becoming widespread and offer significant contributions to improving the delivery\ud of learning and teaching materials. A key factor in the development of hypermedia\ud learning systems is cognitive style (CS) as it relates to users‟ information\ud processing habits, representing individual users‟ typical modes of perceiving,\ud thinking, remembering and problem solving.\ud \ud \ud \ud \ud A total of 97 students from Australian (45) and Malaysian (52) universities\ud participated in a survey. Five types of predictor variables were investigated with\ud the CS: (i) three learning dimensions; (ii) five culture dimensions; (iii) evaluation\ud of units; (iv) demographics of students; and (v) country in which students studied.\ud Both multiple regression models and tree-based regression were used to analyse\ud the direct effect of the five types of predictor variables, and the interactions within\ud each type of predictor variable. When comparing both models, tree-based\ud regression outperformed the generalized linear model in this study. The research\ud findings indicate that unit evaluation is the primary variable to determine students‟\ud CS. A secondary variable is learning dimension and, among the three dimensions,\ud only nonlinear learning and learner control dimensions have an effect on students‟\ud CS. The last variable is culture and, among the five culture dimensions, only\ud power distance, long term orientation, and individualism have effects on students‟\ud CS. Neither demographics nor country have an effect on students‟ CS.\ud These overall findings suggest that traditional unit evaluation, students‟\ud preference for learning dimensions (such as linear vs non-linear), level of learner\ud control and culture orientation must be taken into consideration in order to enrich\ud students‟ quality of education. This enrichment includes motivating students to\ud acquire subject matter through individualized instruction when designing,\ud developing and delivering educational resources

Asymmetrically interacting spreading dynamics on complex layered networks

The spread of disease through a physical-contact network and the spread of information about the disease on a communication network are two intimately related dynamical processes. We investigate the asymmetrical interplay between the two types of spreading dynamics, each occurring on its own layer, by focusing on the two fundamental quantities underlying any spreading process: epidemic threshold and the final infection ratio. We find that an epidemic outbreak on the contact layer can induce an outbreak on the communication layer, and information spreading can effectively raise the epidemic threshold. When structural correlation exists between the two layers, the information threshold remains unchanged but the epidemic threshold can be enhanced, making the contact layer more resilient to epidemic outbreak. We develop a physical theory to understand the intricate interplay between the two types of spreading dynamics.Comment: 29 pages, 14 figure

Functional analysis of EGFR using a conditional allele

Epidermal growth factory receptor (EGFR) is a member of the ERBB family of tyrosine kinase receptors, which includes ERBB2, ERBB3 and ERBB4. EGFR signaling is complicated and involved in a variety of cellular processes, including proliferation, differentiation, migration, adhesion and anti-apoptosis. EGFR has been studied using gene targeting to investigate the in vivo role of the receptor. Constitutional knockout of Egfr in mice results in placental defects with mice dying pre- or perinatally depending on the genetic backgroud. All Egfr null mice that survive to term eventually develop neurodegeneration that is primarily restricted to the cortex and olfactory bulb. Because the existing knockout models are unable to distinguish the cell lineage(s) (ie neuron, astrocyte or both) that depend on EGFR signaling for survival, and also result in pre- or peritnatal lethality limiting the ability to study the role of EGFR in physiological functions or diseases of adults in vivo, thus the generation of an Egfr conditional allele is necessary to overcome this limitation. Herein gene targeting was used in combination with the Cre/loxp system to generate an Egfr conditional allele. This allele was used to develop tissue-specific deletion of EGFR to explore its function in the central nervous system in order to understand the mechanism by which loss of EGFR results in neurodegeneration. After the Egfr conditional allele (Egfrtm1Dwt) was generated, the Egfrtm1Dwt and Egfr[superscript delta], which is generated by Cre-mediated excision in the Egfrtm1Dwt, were characterized showing that the Egfrtm1Dwt possesses wildtype activity and can be inactivated tissue-specially, and the Egfr[superscript delta] is a null allele. To investigate the underlying mechanism responsible for neurodegeneration of Egfr null mice, three Cre transgenic lines expressed in the embryonic epiblast (Sox2-Cre) or neuroprogenitor cells (Nestin-Cre and hGFAP-Cre) were crossed with mice carrying the Egfrtm1Dwt conditional allele to generate Egfrtm1Dwt/tm1Dwt, Sox2-Cre (as well as Nestin-Cre or hGFAP-Cre) mice. Egfrtm1Dwt/tm1Dwt mice also carrying Sox2-Cre or Nestin-Cre displayed neurodegeneration in the cortex, olfactory bulb and areas surrounding lateral ventricle including corpus callosum, the fimbria of the hippocampus and subventricular zone (SVZ) and rostral extension (RE). These results were consistent with the phenotype of Egfr null mice. Conversely, Egfrtm1Dwt/tm1Dwt, hGFAP-Cre mice showed no damage within the brain. To locate differences in the distribution of Cre expression in the brain that leads to different phenotypes in the brain between Egfrtm1Dwt/tm1Dwt, Nestin-Cre and Egfrtm1Dwt/tm1Dwt, hGFAP-Cre mice, Nestin-Cre and hGFAP-Cre mice were crossed with the ROSA26-lacZ reporter mice (R26R). Results indicated that the hGFAP-Cre line expresses Cre in the progenitors of the cortex, olfactory bulb, SVZ, RE and rostral migratory stream (RMS) but unlike Nestin-Cre not the choroid plexus, despite the lack of neurodegeneration in Egfrtm1Dwt/tm1Dwt, hGFAP-Cre mice. These results suggest that neuronal or astrocytic death in the absence of EGFR signaling is a secondary effect, possibly mediated by the choroid plexus

Prostatic Relaxation Induced by Loperamide Is Reduced in Spontaneously Hypertensive Rats

This paper shows a new finding about the decrease of relaxative response to loperamide in prostate of spontaneously hypertensive rats (SHR) as compare to normal rats (WKY). Authors demonstrated the reduction of ATP-sensitive potassium channels is resposible for this change using immunoblotting analysis and the decrease of action induced by diazoxide. This view is not mentioned before and is the first one reporting this result

Awake chronic mouse model of targeted pial vessel occlusion via photothrombosis

Animal models of stroke are used extensively to study the mechanisms involved in the acute and chronic phases of recovery following stroke. A translatable animal model that closely mimics the mechanisms of a human stroke is essential in understanding recovery processes as well as developing therapies that improve functional outcomes. We describe a photothrombosis stroke model that is capable of targeting a single distal pial branch of the middle cerebral artery with minimal damage to the surrounding parenchyma in awake head-fixed mice. Mice are implanted with chronic cranial windows above one hemisphere of the brain that allow optical access to study recovery mechanisms for over a month following occlusion. Additionally, we study the effect of laser spot size used for occlusion and demonstrate that a spot size with small axial and lateral resolution has the advantage of minimizing unwanted photodamage while still monitoring macroscopic changes to cerebral blood flow during photothrombosis. We show that temporally guiding illumination using real-time feedback of blood flow dynamics also minimized unwanted photodamage to the vascular network. Finally, through quantifiable behavior deficits and chronic imaging we show that this model can be used to study recovery mechanisms or the effects of therapeutics longitudinally.R01 EB021018 - NIBIB NIH HHS; R01 MH111359 - NIMH NIH HHS; R01 NS108472 - NINDS NIH HHSPublished versio

Extended π-conjugated pyrene derivatives: structural, photophysical and electrochemical properties

This article presents a set of extended π-conjugated pyrene derivatives, namely 1,3-di(arylethynyl)-7-tert-butylpyrenes, which were synthesized by a Pd-catalyzed Sonogashira coupling reaction of 1,3-dibromo-7-tert-butylpyrenes with the corresponding arylethynyl group in good yields. Despite the presence of the tert-butyl group located at the 7-position of pyrene, X-ray crystallographic analyses show that the planarity of the Y-shaped molecules still exhibits strong face-to-face π-π stacking in the solid state; all of the compounds exhibit blue or green emission with high quantum yields (QYs) in dichloromethane. DFT calculations and electrochemistry revealed that this category of compound possesses hole-transporting characteristics. In addition, with strong electron-donating (-N(CH₃)₂) or electron-withdrawing (-CHO) groups in 2 d or 2 f, these molecules displayed efficient intramolecular charge-transfer (ICT) emissions with solvatochromic shifts from blue to yellow (green) on increasing the solvent polarity. Furthermore, the compounds 2 d and 2 f possess strong CT characteristics

Factors Predicting Emotional Cue-Responding Behaviors of Nurses in Taiwan: An Observational Study

Objective Responding to emotional cues is an essential element of therapeutic communication. The purpose of this study is to examine nurses' competence of responding to emotional cues (CRE) and related factors while interacting with standardized patients with cancer. Methods This is an exploratory and predictive correlational study. A convenience sample of registered nurses who have passed the probationary period in southern Taiwan was recruited to participate in 15-minute videotaped interviews with standardized patients. The Medical Interview Aural Rating Scale was used to describe standardized patients' emotional cues and to measure nurses' CRE. The State-Trait Anxiety Inventory was used to evaluate nurses' anxiety level before the conversation. We used descriptive statistics to describe the data and stepwise regression to examine the predictors of nurses' CRE. Results A total of 110 nurses participated in the study. Regardless of the emotional cue level, participants predominately responded to cues with inappropriate distancing strategies. Prior formal communication training, practice unit, length of nursing practice, and educational level together explain 36.3% variances of the nurses' CRE. Conclusions This study is the first to explore factors related to Taiwanese nurses' CRE. Compared to nurses in other countries, Taiwanese nurses tended to respond to patients' emotional cues with more inappropriate strategies. We also identified significant predictors of CRE that show the importance of communication training. Future research and education programs are needed to enhance nurses' CRE and to advocate for emotion-focused communication

The local environment of Dy3+in selenium-rich chalcogenide glasses

The environment of Dy3+ is investigated when it is added as DyCl3 or Dy foil into two base glasses, Ge16.5As19−xGaxSe64.5, where x = 3 or 10 at%, at doping levels between 0 and 3000 parts per million by weight (ppmw) Dy3+. Extended X-ray Absorption Fine Structure demonstrates the glasses doped with Dy foil, or less than 1000 ppmw Dy3+ as DyCl3, contain Dy ions that are fully incorporated into the glass network and are coordinated by 7–8 Se atoms. However, when the DyCl3 dopant is present in concentrations ≥1000 ppmw Dy3+ the environment is dominated by Dy–Cl bonds. Furthermore, these Dy–Cl environments are nanocrystalline, retaining chemical order beyond the first coordination shell. By comparison with XRD and FTIR results, we report that the presence of α-Ga2Se3 crystallites in the glass, and the increased optical scattering in the fibres, are both related to the presence of DyCl3 crystallites

Malignant mesenchymal tumor with leiomyosarcoma, rhabdomyosarcoma, chondrosarcoma, and osteosarcoma differentiation: case report and literature review

A case of malignant mesenchymoma of the bladder containing leiomyosarcoma, rhabdomyosarcoma, chondrosarcoma, osteosarcoma, and myxomatous components is described. The primary pedunculated tumor measuring 14 × 13 × 7 cm and weighing 343 g arose from the left trigone of the bladder and was treated by total cystectomy. The histogenesis of malignant mesenchymomas and their optimal management strategy and prognosis remain uncertain. Herein, we present the fifth case of malignant mesenchymoma of the urinary bladder to be reported in the literature, which presented five unrelated differentiated tissues more than did previously reported cases