Synthesis of ABA Tri-Block Co-Polymer Magnetopolymersomes via Electroporation for Potential Medical Application

The ABA tri-block copolymer poly(2-methyloxazoline)–poly(dimethylsiloxane)–poly(2-methyloxazoline) (PMOXA–PDMS–PMOXA) is known for its capacity to mimic a bilayer membrane in that it is able to form vesicular polymersome structures. For this reason, it is the subject of extensive research and enables the development of more robust, adaptable and biocompatible alternatives to natural liposomes for biomedical applications. However, the poor solubility of this polymer renders published methods for forming vesicles unreproducible, hindering research and development of these polymersomes. Here we present an adapted, simpler method for the production of PMOXA–PDMS–PMOXA polymersomes of a narrow polydispersity (45 ± 5.8 nm), via slow addition of aqueous solution to a new solvent/polymer mixture. We then magnetically functionalise these polymersomes to form magnetopolymersomes via in situ precipitation of iron-oxide magnetic nanoparticles (MNPs) within the PMOXA–PDMS–PMOXA polymersome core and membrane. This is achieved using electroporation to open pores within the membrane and to activate the formation of MNPs. The thick PMOXA–PDMS–PMOXA membrane is well known to be relatively non-permeable when compared to more commonly used di-block polymer membranes due a distinct difference in both size and chemistry and therefore very difficult to penetrate using standard biological methods. This paper presents for the first time the application of electroporation to an ABA tri-block polymersome membrane (PMOXA–PDMS–PMOXA) for intravesicular in situ precipitation of uniform MNPs (2.6 ± 0.5 nm). The electroporation process facilitates the transport of MNP reactants across the membrane yielding in situ precipitation of MNPs. Further to differences in length and chemistry, a tri-block polymersome membrane structure differs from a natural lipid or di-block polymer membrane and as such the application and effects of electroporation on this type of polymersome is entirely novel. A mechanism is hypothesised to explain the final structure and composition of these biomedically applicable tri-block magnetopolymersomes

Applying Task Force Recommendations on Integrating Science and Practice in Health Service Psychology Education

The proper role of research skills and training to conduct research in professional psychology education has been controversial throughout the history of the field. An extensive effort was undertaken recently to address that issue and identify ways the field might move forward in a more unified manner. In 2015, the American Psychological Association (APA) Board of Educational Affairs convened a task force to address one of the recommendations made by the Health Service Psychology Education Collaborative in 2013. That recommendation stated that the education and training of health service psychologists (HSPs) include an integrative approach to science and practice that incorporates scientific-mindedness, training in research skills, and goes well beyond merely “consuming” research findings. The task force subsequently developed recommendations related to the centrality of science competencies for HSPs and how these competencies extend beyond training in evidence-based practice. This article discusses the findings of the task force and the implications of its recommendations for education and training in HSP. The challenges and opportunities associated with implementing these recommendations in HSP graduate programs are examined

PLIF Visualization of Active Control of Hypersonic Boundary Layers Using Blowing

Planar laser-induced fluorescence (PLIF) imaging was used to visualize the boundary layer flow on a 1/3-scale Hyper-X forebody model. The boundary layer was perturbed by blowing out of orifices normal to the model surface. Two blowing orifice configurations were used: a spanwise row of 17-holes spaced at 1/8 inch, with diameters of 0.020 inches and a single-hole orifice with a diameter of 0.010 inches. The purpose of the study was to visualize and identify laminar and turbulent structures in the boundary layer and to make comparisons with previous phosphor thermography measurements of surface heating. Jet penetration and its influence on the boundary layer development was also examined as was the effect of a compression corner on downstream boundary layer transition. Based upon the acquired PLIF images, it was determined that global surface heating measurements obtained using the phosphor thermography technique provide an incomplete indicator of transitional and turbulent behavior of the corresponding boundary layer flow. Additionally, the PLIF images show a significant contribution towards transition from instabilities originating from the underexpanded jets. For this experiment, a nitric oxide/nitrogen mixture was seeded through the orifices, with nitric oxide (NO) serving as the fluorescing gas. The experiment was performed in the 31-inch Mach 10 Air Tunnel at NASA Langley Research Center

Human Immunodeficiency Virus Screening: Knowledge, Attitudes, Perceived Norms, and Control Beliefs of Advanced Practice Registered Nurses in Colorado

The purpose of this evidence-based practice project was to increase the knowledge base to address the barriers preventing routine screening of the human immunodeficiency virus (HIV). The project consisted of a statewide survey to assess the knowledge, attitudes, perceived norms, control beliefs, barriers, and facilitators of advanced practice registered nurses (APRNs) across Colorado. A statewide assessment is important in the state of Colorado because APRNs are the primary providers in many rural areas. There were 66 responses to the survey. Knowledge of the Centers for Disease Control and Prevention (CDC; 2018) guideline for HIV screening was lacking. About one-third of the APRNs did not know the CDC guideline applied to all patients age 13 to 64 and was not just for high risk groups of which the Black/African American race and healthcare workers were not. The APRNs were influenced by actions of other APRNs but did not screen per CDC guidelines for many reasons. Although the APRNs were confident in HIV screening, they wanted resources for where they could get more information and where to send patients who might have a positive HIV test. This project provided the basis for future education interventions that could utilize a pre/post survey with an educational session either in the rural setting or via webinar

Fluorescence Visualization of Hypersonic Flow Past Triangular and Rectangular Boundary-layer Trips

Planar laser-induced fluorescence (PLIF) flow visualization has been used to investigate the hypersonic flow of air over surface protrusions that are sized to force laminar-to-turbulent boundary layer transition. These trips were selected to simulate protruding Space Shuttle Orbiter heat shield gap-filler material. Experiments were performed in the NASA Langley Research Center 31-Inch Mach 10 Air Wind Tunnel, which is an electrically-heated, blowdown facility. Two-mm high by 8-mm wide triangular and rectangular trips were attached to a flat plate and were oriented at an angle of 45 degrees with respect to the oncoming flow. Upstream of these trips, nitric oxide (NO) was seeded into the boundary layer. PLIF visualization of this NO allowed observation of both laminar and turbulent boundary layer flow downstream of the trips for varying flow conditions as the flat plate angle of attack was varied. By varying the angle of attack, the Mach number above the boundary layer was varied between 4.2 and 9.8, according to analytical oblique-shock calculations. Computational Fluid Dynamics (CFD) simulations of the flowfield with a laminar boundary layer were also performed to better understand the flow environment. The PLIF images of the tripped boundary layer flow were compared to a case with no trip for which the flow remained laminar over the entire angle-of-attack range studied. Qualitative agreement is found between the present observed transition measurements and a previous experimental roughness-induced transition database determined by other means, which is used by the shuttle return-to-flight program

The window period of NEUROGENIN3 during human gestation

The basic helix-loop-helix transcription factor, NEUROG3, is critical in causing endocrine commitment from a progenitor cell population in the developing pancreas. In human, NEUROG3 has been detected from 8 weeks postconception (wpc). However, the profile of its production and when it ceases to be detected is unknown. In this study we have defined the profile of NEUROG3 detection in the developing pancreas to give insight into when NEUROG3- dependent endocrine commitment is possible in the human fetus. Immunohistochemistry allowed counting of cells with positively stained nuclei from 7 wpc through to term. mRNA was also isolated from sections of human fetal pancreas and NEUROG3 transcription analyzed by quantitative reverse transcription and polymerase chain reaction. NEUROG3 was detected as expected at 8 wpc. The number of NEUROG3-positive cells increased to peak levels between 10 wpc and 14 wpc. It declined at and after 18 wpc such that it was not detected in human fetal pancreas at 35-41 wpc. Analysis of NEUROG3 transcription corroborated this profile by demonstrating very low levels of transcript at 35-41 wpc, more than 10-fold lower than levels at 12-16 wpc. These data define the appearance, peak and subsequent disappearance of the critical transcription factor, NEUROG3, in human fetal pancreas for the first time. By inference, the window for pancreatic endocrine differentiation via NEUROG3 action opens at 8 wpc and closes between 21 and 35 wpc

Inter-relationships among alternative definitions of feed efficiency in grazing lactating dairy cows

peer-reviewedInternational interest in feed efficiency, and in particular energy intake and residual energy intake (REI), is intensifying due to a greater global demand for animal-derived protein and energy sources. Feed efficiency is a trait of economic importance, and yet is overlooked in national dairy cow breeding goals. This is due primarily to a lack of accurate data on commercial animals, but also a lack of clarity on the most appropriate definition of the feed intake and utilization complex. The objective of the present study was to derive alternative definitions of energetic efficiency in grazing lactating dairy cows and to quantify the inter-relationships among these alternative definitions. Net energy intake (NEI) from pasture and concentrate intake was estimated up to 8 times per lactation for 2,693 lactations from 1,412 Holstein-Friesian cows. Energy values of feed were based on the French Net Energy system where 1 UFL is the net energy requirements for lactation equivalent of 1 kg of air-dry barley. A total of 8,183 individual feed intake measurements were available. Energy balance was defined as the difference between NEI and energy expenditure. Efficiency traits were either ratio-based or residual-based; the latter were derived from least squares regression models. Residual energy intake was defined as NEI minus predicted energy to fulfill the requirements for the various energy sinks. The energy sinks (e.g., NEL, metabolic live weight) and additional contributors to energy kinetics (e.g., live weight loss) combined, explained 59% of the variation in NEI, implying that REI represented 41% of the variance in total NEI. The most efficient 10% of test-day records, as defined by REI (n = 709), on average were associated with a 7.59 UFL/d less NEI (average NEI of the entire population was 16.23 UFL/d) than the least efficient 10% of test-day records based on REI (n = 709). Additionally, the most efficient 10% of test-day records, as defined by REI, were associated with superior energy conversion efficiency (ECE, i.e., NEL divided by NEI; ECE = 0.55) compared with the least efficient 10% of test-day records (ECE = 0.33). Moreover, REI was positively correlated with energy balance, implying that more negative REI animals (i.e., deemed more efficient) are expected to be, on average, in greater negative energy balance. Many of the correlations among the 14 defined efficiency traits differed from unity, implying that each trait is measuring a different aspect of efficiency.The authors gratefully acknowledge funding from the Irish Department of Agriculture, Food and Marine (Dublin, Ireland) Research Stimulus Fund project GENCOST, and funding from the Marie Curie project International Research Staff Exchange Scheme SEQSE

TIME-DEPENDENCE OF DISTAL-TO-PROXIMAL HIPPOCAMPAL NEURODEGENERATION PRODUCED BY N-METHYL-D-ASPARTATE RECEPTOR ACTIVATION

Excitotoxicity is the overexcitation of neurons due to the excessive activation of excitatory amino acid receptors and is thought to be involved in many neurodegenerative states. The manner in which the neuron breaks down during excitotoxicity is still unclear. The current study used the organotypic hippocampal slice culture model to examine the time-dependent loss of the synaptic vesicular protein synaptophysin and the loss of N-methyl-D-aspartate (NMDA) receptor NR1 subunit availability following an excitotoxic insult (20 μM NMDA) to provide a better understanding of the topographical nature of neuronal death following NMDA receptor activation. Significant NMDA-induced cytotoxicity in the CA1 region of the hippocampus (as measured by propidium iodide uptake) was evident early (15 minutes after exposure) while significant loss of the NR1 subunit and synaptophysin was found at later timepoints (72 and 24 hours, respectively), suggesting delayed downregulation or degradation in axons and dendrites as compared to the soma. The addition of the competitive NMDA receptor antagonist 2-amino-7-phosphonovaleric acid (APV) significantly attenuated all NMDA-induced effects. These results suggest that NR1 and synaptophysin levels as measured by immunoreactivity are not reliable indicators of early cell death