Analysis of endocytosis at eisosomes

The yeast plasma membrane contains at least three microdomains – membrane compartment containing Pma1 (MCP), membrane compartment containing TORC2 (MCT) and membrane compartment containing Can1 (MCC). Eisosomes underlie the MCC domain defined by the marker protein arginine permease (Can1). Eisosomes are large protein assemblies composed of Pil1 and Lsp1 proteins, of which Pil1 is essential for plasma membrane organization. We found that the uncharacterized AAA-ATPase protein Yta6 dynamically colocalizes with eisosomes. Yta6 physically interacts with eisosome components, specifically with Pil1. In PIL1 deletion cells, Yta6 is unable to localize normally to the plasma membrane. Yta6 foci colocalize with the intermediates of FM4-64 on the plasma membrane. The number of these intermediates is increased upon overexpression of Yta6. Overexpressed Yta6 is also able to rescue the defects of endocytosis in cells devoid of amphiphysins. Together rescue experiments and colocalization of a protein cargo Hxt3 with eisosomes suggest that Yta6 likely plays a role in endocytosis at eisosomes. To identify genes whose products function together with eisosome components, we independently carried out a genetic interaction study (epistatic mini array profile) which revealed the protein Emp70. EMP70 showed the strongest correlation in genetic profile with PIL1. Emp70 localizes to a subset of eisosomes in addition to its localization in endosomes and vacuoles. We found eisosomes are required for normal numbers of Emp70 plasma membrane foci. Deletion of Emp70 misdirected endosomal protein Kex2 to vacuole, implicating its essential role in maintaining the architecture of the endosomal compartment. In summary, Yta6 likely plays a role in initiation of endocytosis at eisosomes and Emp70 during intracellular trafficking from plasma membrane to vacuole

Tri-band millimetre-wave antenna for body-centric networks

This paper presents design of a tri-band slotted patch antenna operating at millimetre-wave frequencies of 28 GHz, 38 GHz and 61 GHz. The proposed antenna carries an overall size of 5.1mm×5mm×0.254mm employing a single layer, slotted patch structure combining L- and F-shaped slots. It is excited by a single-feed microstrip line. The antenna is tested in free space as well as in wearable configurations and results show that it offers a good impedance matching, sufficient -10 dB bandwidth and wide radiation coverage at the three bands of interest effectively countering the effects of human body presence. It achieves a peak gain of 7.2 dBi in off-body and 8.3 dBi in on-body configuration. Minimum efficiency values are observed to be 85% in off-body while 54% in on-body scenarios. A comparative analysis with published relevant work shows that the proposed antenna is inexpensive, easy to integrate and works efficiently in tri-band wearable and implantable arrangements. These features make it a good candidate for current and future applications of Body-centric Networks operating at millimetre-wave ranges

The Implicit Association Test in health professions education: A meta-narrative review

Introduction: Implicit bias is a growing area of interest among educators. Educational strategies used to elicit awareness of implicit biases commonly include the Implicit Association Test (IAT). Although the topic of implicit bias is gaining increased attention, emerging critique of the IAT suggests the need to subject its use to greater theoretical and empirical scrutiny. Methods: The authors employed a meta-narrative synthesis to review existing research on the use of the IAT in health professions education. Four databases were searched using key terms yielding 1151 titles. After title, abstract and full-text screening, 38 articles were chosen for inclusion. Coding and analysis of articles sought a meaningful synthesis of educational approaches relating to the IAT, and the assumptions and theoretical positions that informed these approaches. Results: Distinct, yet complementary, meta-narratives were found in the literature. The dominant perspective utilizes the IAT as a metric of implicit bias to evaluate the success of an educational activity. A contrasting narrative describes the IAT as a tool to promote awareness while triggering discussion and reflection. Discussion: Whether used as a tool to measure bias, raise awareness or trigger reflection, the use of the IAT provokes tension between distinct meta-narratives, posing a challenge to educators. Curriculum designers should consider the premise behind the IAT before using it, and be prepared to address potential reactions from learners such as defensiveness or criticism. Overall, findings suggest that educational approaches regarding implicit bias require critical reflexivity regarding assumptions, values and theoretical positioning related to the IAT

Job Monitoring in an Interactive Grid Analysis Environment

The grid is emerging as a great computational resource but its dynamic behavior makes the Grid environment unpredictable. Systems and networks can fail, and the introduction of more users can result in resource starvation. Once a job has been submitted for execution on the grid, monitoring becomes essential for a user to see that the job is completed in an efficient way, and to detect any problems that occur while the job is running. In current environments once a user submits a job he loses direct control over the job and the system behaves like a batch system: the user submits the job and later gets a result back. The only information a user can obtain about a job is whether it is scheduled, running, cancelled or finished. Today users are becoming increasingly interested in such analysis grid environments in which they can check the progress of the job, obtain intermediate results, terminate the job based on the progress of job or intermediate results, steer the job to other nodes to achieve better performance and check the resources consumed by the job. In order to fulfill their requirements of interactivity a mechanism is needed that can provide the user with real time access to information about different attributes of a job. In this paper we present the design of a Job Monitoring Service, a web service that will provide interactive remote job monitoring by allowing users to access different attributes of a job once it has been submitted to the interactive Grid Analysis Environment

Rejuvenation of brain, liver and muscle by simultaneous pharmacological modulation of two signaling determinants, that change in opposite directions with age.

We hypothesize that altered intensities of a few morphogenic pathways account for most/all the phenotypes of aging. Investigating this has revealed a novel approach to rejuvenate multiple mammalian tissues by defined pharmacology. Specifically, we pursued the simultaneous youthful in vivo calibration of two determinants: TGF-beta which activates ALK5/pSmad 2,3 and goes up with age, and oxytocin (OT) which activates MAPK and diminishes with age. The dose of Alk5 inhibitor (Alk5i) was reduced by 10-fold and the duration of treatment was shortened (to minimize overt skewing of cell-signaling pathways), yet the positive outcomes were broadened, as compared with our previous studies. Alk5i plus OT quickly and robustly enhanced neurogenesis, reduced neuro-inflammation, improved cognitive performance, and rejuvenated livers and muscle in old mice. Interestingly, the combination also diminished the numbers of cells that express the CDK inhibitor and marker of senescence p16 in vivo. Summarily, simultaneously re-normalizing two pathways that change with age in opposite ways (up vs. down) synergistically reverses multiple symptoms of aging

In vitro activity of immunosuppressive drugs against Plasmodium falciparum

Background Solid organ transplant recipients are particularly vulnerable for infectious diseases due to prolonged immunosuppressive treatment. Residents of endemic regions and travellers may be exposed to malaria and may, therefore, require prolonged antimalarial chemoprophylaxis. The hypothesis of this study was that certain immunosuppressive drugs may exert clinically relevant anti- malarial activity. It was therefore designed to assess the intrinsic anti- malarial activity of everolimus, mycophenolic acid, and rapamycin against Plasmodium falciparum in an in vitro model. Methods Three laboratory adapted clones of P. falciparum and two isolates were used to assess the potential of mycophenolic acid, rapamycin and everolimus to inhibit in vitro growth of P. falciparum. The standard histidine rich protein 2 assay was employed and inhibitory drug concentrations (IC) were computed by non-linear regression analysis. Results All drugs were associated with complete inhibition of P. falciparum growth in in vitro assays. Mycophenolic acid demonstrated IC50 and IC90 values of 5.4 μmol/L and 15.3 μmol/L. Rapamycin inhibited P. falciparum growth at 7.2 μmol/L (IC50) and 12.5 μmol/L (IC90), respectively. Finally, everolimus displayed IC50 and IC90 values of 6.2 μmol/L and 11.5 μmol/L. There was no difference in in vitro activity against chloroquine sensitive or chloroquine resistant parasites. Conclusions All immunosuppressive drugs evaluated in this in vitro study demonstrated activity against P. falciparum. Inhibitory concentrations of mycophenolic acid are within clinically achievable plasma concentrations when used in solid organ transplant recipients. Further in vivo evaluation of mycophenolic acid either alone or in combination regimens may prove promising for the concomitant prevention of P. falciparum in solid organ transplant recipients living or travelling in malaria endemic regions

Analysis and monitoring of single HaCaT cells using volumetric Raman mapping and machine learning

No explorer reached a pole without a map, no chef served a meal without tasting, and no surgeon implants untested devices. Higher accuracy maps, more sensitive taste buds, and more rigorous tests increase confidence in positive outcomes. Biomedical manufacturing necessitates rigour, whether developing drugs or creating bioengineered tissues [1]–[4]. By designing a dynamic environment that supports mammalian cells during experiments within a Raman spectroscope, this project provides a platform that more closely replicates in vivo conditions. The platform also adds the opportunity to automate the adaptation of the cell culture environment, alongside spectral monitoring of cells with machine learning and three-dimensional Raman mapping, called volumetric Raman mapping (VRM). Previous research highlighted key areas for refinement, like a structured approach for shading Raman maps [5], [6], and the collection of VRM [7]. Refining VRM shading and collection was the initial focus, k-means directed shading for vibrational spectroscopy map shading was developed in Chapter 3 and exploration of depth distortion and VRM calibration (Chapter 4). “Cage” scaffolds, designed using the findings from Chapter 4 were then utilised to influence cell behaviour by varying the number of cage beams to change the scaffold porosity. Altering the porosity facilitated spectroscopy investigation into previously observed changes in cell biology alteration in response to porous scaffolds [8]. VRM visualised changed single human keratinocyte (HaCaT) cell morphology, providing a complementary technique for machine learning classification. Increased technical rigour justified progression onto in-situ flow chamber for Raman spectroscopy development in Chapter 6, using a Psoriasis (dithranol-HaCaT) model on unfixed cells. K-means-directed shading and principal component analysis (PCA) revealed HaCaT cell adaptations aligning with previous publications [5] and earlier thesis sections. The k-means-directed Raman maps and PCA score plots verified the drug-supplying capacity of the flow chamber, justifying future investigation into VRM and machine learning for monitoring single cells within the flow chamber

A stable TiO2_{2}–graphene nanocomposite anode with high rate capability for lithium-ion batteries

A rapid microwave hydrothermal process is adopted for the synthesis of titanium dioxide and reduced graphene oxide nanocomposites as high-performance anode materials for Li-ion batteries. With the assistance of hydrazine hydrate as a reducing agent, graphene oxide was reduced while TiO$_{2}$ nanoparticles were grown in situ on the nanosheets to obtain the nanocomposite material. The morphology of the nanocomposite obtained consisted of TiO$_{2}$ particles with a size of ∼100 nm, uniformly distributed on the reduced graphene oxide nanosheets. The as-prepared TiO$_{2}$–graphene nanocomposite was able to deliver a capacity of 250 mA h g−1 ± 5% at 0.2C for more than 200 cycles with remarkably stable cycle life during the Li+ insertion/extraction process. In terms of high rate capability performance, the nanocomposite delivered discharge capacity of ca. 100 mA h g−1 with >99% coulombic efficiency at C-rates of up to 20C. The enhanced electrochemical performance of the material in terms of high rate capability and cycling stability indicates that the as-developed TiO$_{2}$–rGO nanocomposites are promising electrode materials for future Li-ion batteries