436 research outputs found
Student Perception of a Visual Novel for Fostering Science Process Skills
In undergraduate science education, emphasis is often placed on teaching subject matter rather than science process skills (e.g., critical thinking, problem solving). Although important to scientific training, these skills are often not taught because science educators do not feel equipped to teach them. We therefore present a case-scenario activity that aims to facilitate the development of science process skills. This activity, which takes the form of a visual novel, asks students to generate hypotheses for the seemingly odd events that are described in the story. We implemented this activity in a science-process-focused course. Upon completion of the activity, we asked students to submit a written response to the prompt: “What are you taking away from the activity?” In this exploratory study, we conducted a qualitative analysis of these written responses to ascertain whether meaningful codes and themes related to science process would arise from this open-ended prompt. Based on student responses, four main themes emerged: scientific inquiry, student satisfaction, flexibility, and collaboration. These results demonstrated the activity was both enjoyable, and it successfully enabled students to apply science process skills. We offer this activity in anticipation it will provide educators with a tool to include these skills in their classes
A study protocol to investigate the relationship between dietary fibre intake and fermentation, colon cell turnover, global protein acetylation and early carcinogenesis: the FACT study
Background: A number of studies, notably EPIC, have shown a descrease in colorectal cancer risk associated with increased fibre consumption. Whilst the underlying mechanisms are likely to be multifactorial, production of the short-chain fatty-acid butyrate fro butyratye is frequently cited as a major potential contributor to the effect. Butyrate inhibits histone deacetylases, which work on a wide range of proteins over and above histones. We therefore hypothesized that alterations in the acetylated proteome may be associated with a cancer risk phenotype in the colorectal mucosa, and that such alterations are candidate biomarkers for effectiveness of fibre interventions in cancer prevention.
Methods an design: There are two principal arms to this study: (i) a cross-sectional study (FACT OBS) of 90 subjects recruited from gastroenterology clinics and; (ii) an intervention trial in 40 subjects with an 8 week high fibre intervention. In both studies the principal goal is to investigate a link between fibre intake, SCFA production and global protein acetylation. The primary measure is level of faecal butyrate, which it is hoped will be elevated by moving subjects to a high fibre diet. Fibre intakes will be estimated in the cross-sectional group using the EPIC Food Frequency Questionnaire. Subsidiary measures of the effect of butyrate on colon mucosal function and precancerous phenotype will include measures of apoptosis, apoptotic regulators cell cycle and cell division.
Discussion: This study will provide a new level of mechanistic data on alterations in the functional proteome in response to the colon microenvironment which may underwrite the observed cancer preventive effect of fibre. The study may yield novel candidate biomarkers of fibre fermentation and colon mucosal function
Phase phonon spectrum and melting in a quantum rotor model with diagonal disorder
We study the zero-temperature () quantum rotor model with on-site
disorder in the charging energy. Such a model may serve as an idealized
Hamiltonian for an array of Josephson-coupled small superconducting grains, or
superfluid He in a disordered environment. In the approximation of
small-amplitude phase fluctuations, the Hamiltonian maps onto a system of
coupled harmonic oscillators with on-site disorder. We study the effects of
disorder in this harmonic regime, using the coherent potential approximation
(CPA), obtaining the density of states and the lifetimes of the spin-wave-like
excitations for several choices of the parameters which characterize the
disorder. Finally, we estimate the parameters characterizing the
quantum melting of the phase order, using a suitable Lindemann criterion.Comment: 8 pages, 5 figures. To be published in Phys. Rev. B. Minor change
Multifunctional Properties of Chicken Embryonic Prenatal Mesenchymal Stem Cells- Pluripotency, Plasticity, and Tumor Suppression
The chick embryo represents an accessible and economical in vivo model, which has long been used in developmental biology, gene expression analysis, and loss/gain of function experiments. In the present study, we assessed and characterized bone marrow derived mesenchymal stem cells from prenatal day 13 chicken embryos (chBMMSCs) and determined some novel properties. After assessing the mesenchymal stem cell (MSC) properties of these cells by the presence of their signature markers (CD 44, CD 73, CD 90, CD 105, and vimentin), we ascertained a very broad spectrum of multipotentiality as these MSCs not only differentiated into the classic tri-lineages of MSCs but also into ectodermal, endodermal, and mesodermal lineages such as neuron, hepatocyte, islet cell, and cardiac. In addition to wide plasticity, we detected the presence of several pluripotent markers such as Oct4, Sox2, and Nanog. This is the first study characterizing prenatal chBMMSCs and their ability to not only differentiate into mesenchymal lineages but also into all the germ cell layer lineages. Furthermore, our studies indicate that prenatal chBMMSCs derived from the chick provide an excellent model for multi-lineage development studies because of their broad plasticity and faithful reproduction of MSC traits as seen in the human. Here, we also present evidence for the first time that media derived from prenatal chBMMSC cultures have an anti-tumorigenic, anti-migratory, and pro-apoptotic effect on human tumors cells acting through the Wnt-ß-catenin pathway. These data confirm that chBMMSCs are enriched with factors in their secretome that are able to destroy tumor cells. This suggests a commonality of properties of MSCs across species between human and chicken
Spintronics: Fundamentals and applications
Spintronics, or spin electronics, involves the study of active control and
manipulation of spin degrees of freedom in solid-state systems. This article
reviews the current status of this subject, including both recent advances and
well-established results. The primary focus is on the basic physical principles
underlying the generation of carrier spin polarization, spin dynamics, and
spin-polarized transport in semiconductors and metals. Spin transport differs
from charge transport in that spin is a nonconserved quantity in solids due to
spin-orbit and hyperfine coupling. The authors discuss in detail spin
decoherence mechanisms in metals and semiconductors. Various theories of spin
injection and spin-polarized transport are applied to hybrid structures
relevant to spin-based devices and fundamental studies of materials properties.
Experimental work is reviewed with the emphasis on projected applications, in
which external electric and magnetic fields and illumination by light will be
used to control spin and charge dynamics to create new functionalities not
feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes
from the published versio
Factors associated with tocolytic hospitalizations in Taiwan: evidence from a population-based and longitudinal study from 1997 to 2004
<p>Abstract</p> <p>Background</p> <p>The use of tocolytic hospitalization in antenatal care is controversial and worthy of more research. We investigated individual, institutional, and area factors that affect the use of tocolytic hospitalizations in Taiwan where fertility has rapidly declined.</p> <p>Methods</p> <p>Longitudinal data from the 1996 to 2004 National Health Insurance Research Database in Taiwan were used to identify tocolytic hospitalizations. The probit model was used to estimate factors associated with tocolytic hospitalizations.</p> <p>Results</p> <p>The decline in fertility was significantly associated with the probability of tocolytic hospitalizations. Several physician and institutional factors-including physician's age, hospital ownership, accreditation status, bed size, and teaching status-were also significantly correlated to the dependent variables.</p> <p>Conclusions</p> <p>The provision of inpatient tocolysis is influenced not only by clinical considerations but also by physician, institutional, and area factors unrelated to clinical need. Fertility declines in Taiwan may have led obstetricians/gynecologists to provide more tocolysis to make up for their lost income. If the explanation is further validated, reimbursement policies may need to be reviewed to correct for overuse of inpatient tocolysis. The correlation could also be explained by the increasing use of artificial reproductive technologies and higher social value of newborns. In addition, the physician and institutional variations observed in the study indicate potential misuse of inpatient tocolysis that warrant further investigation.</p
Presenilin Controls CBP Levels in the Adult Drosophila Central Nervous System
Background: Dominant mutations in both human Presenilin (Psn) genes have been correlated with the formation of amyloid plaques and development of familial early-onset Alzheimer’s disease (AD). However, a definitive mechanism whereby plaque formation causes the pathology of familial and sporadic forms of AD has remained elusive. Recent discoveries of several substrates for Psn protease activity have sparked alternative hypotheses for the pathophysiology underlying AD. CBP (CREB-binding protein) is a haplo-insufficient transcriptional co-activator with histone acetly-transferase (HAT) activity that has been proposed to be a downstream target of Psn signaling. Individuals with altered CBP have cognitive deficits that have been linked to several neurological disorders. Methodology/Principal Findings: Using a transgenic RNA-interference strategy to selectively silence CBP, Psn, and Notch in adult Drosophila, we provide evidence for the first time that Psn is required for normal CBP levels and for maintaining specific global acetylations at lysine 8 of histone 4 (H4K8ac) in the central nervous system (CNS). In addition, flies conditionally compromised for the adult-expression of CBP display an altered geotaxis behavior that may reflect a neurological defect. Conclusions/Significance: Our data support a model in which Psn regulates CBP levels in the adult fly brain in a manner that is independent of Notch signaling. Although we do not understand the molecular mechanism underlying th
Polymeric drift control adjuvants for agricultural spraying
The movement of a pesticide or herbicide to an off-target site during agricultural spraying can cause injury to wildlife, plants and contamination of surface water. This phenomenon is known as spray drift and can be controlled by spraying during favorable environmental conditions, and by using low drift nozzles and drift control adjuvants (DCAs). Polymeric DCAs are the most common type of DCA and function by increasing the droplet size produced during spraying. There are, however, two main drawbacks of polymeric DCAs; they are prone to mechanical degradation during spraying which reduces their performance and they can produce oversized drops which reduces the efficacy of the spray. In this trend article, existing DCA technology is reviewed including the mechanism through which they function. This then provides a platform for the discussion of novel polymeric architectures which have currently not been applied in DCA formulations
Technology transfer model for Austrian higher education institutions
The aim of this paper is to present the findings of a PhD research (Heinzl 2007, Unpublished PhD Thesis) conducted on the Universities of Applied Sciences in Austria. Four of the models that emerge from this research are: Generic Technology Transfer Model (Sect. 5.1); Idiosyncrasies Model for the Austrian Universities of Applied Sciences (Sect. 5.2); Idiosyncrasies-Technology Transfer Effects Model (Sect. 5.3); Idiosyncrasies-Technology Transfer Cumulated Effects Model (Sect. 5.3). The primary and secondary research methods employed for this study are: literature survey, focus groups, participant observation, and interviews. The findings of the research contribute to a conceptual design of a technology transfer system which aims to enhance the higher education institutions' technology transfer performance. © 2012 Springer Science+Business Media, LLC
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