9,068 research outputs found
Clonal analysis of meningococci during a 26 year period prior to the introduction of meningococcal serogroup C vaccines
Meningococcal disease remains a public health burden in the UK and elsewhere. Invasive Neisseria meningitidis, isolated in Scotland between 1972 and 1998, were characterised retrospectively to examine the serogroup and clonal structure of the circulating population. 2607 isolates causing invasive disease were available for serogroup and MLST analysis whilst 2517 were available for multilocus sequence typing (MLST) analysis only. Serogroup distribution changed from year to year but serogroups B and C were dominant throughout. Serogroup B was dominant throughout the 1970s and early 1980s until serogroup C became dominant during the mid-1980s. The increase in serogroup C was not associated with one particular sequence type (ST) but was associated with a number of STs, including ST-8, ST-11, ST-206 and ST-334. This is in contrast to the increase in serogroup C disease seen in the 1990s that was due to expansion of the ST-11 clonal complex. While there was considerable diversity among the isolates (309 different STs among the 2607 isolates), a large proportion of isolates (59.9%) were associated with only 10 STs. These data highlight meningococcal diversity over time and the need for ongoing surveillance during the introduction of new meningococcal vaccines
Surveillance and Elimination of Bacteriophage Contamination in an Industrial Fermentation Process
Commercial fermentation processes are often vulnerable to bacteriophage due to the lack of genetic diversity and use of high cell density cultures. Bacteriophage infections in these fermentations can have adverse impacts on operability of the production facility and product quality and prevent recovery of valuable bioproducts in the downstream process. Prevention strategies have been developed and optimized through feedback from bacteriophage diagnostic tests, which inform improvements to process design for elimination of entry points, as well as modification of the biocatalyst to reduce or eliminate bacteriophage virulence. In this chapter, we provide case studies for successful elimination of bacteriophage virulence via host modifications, including bacteriophage binding-site modifications on the outer membrane of an Escherichia coli production host, used for commercial manufacture of 1,3-propanediol, as well as application of CRISPR-associated protein 9 (Cas9) for bacteriophage immunity. Finally, we report application of bacteriophage diagnostic methods to fully characterize and eliminate bacteriophage entry points in a commercial fermentation process
Indian nurses in the United Kingdom: a two-phase study of the expatriate-host country national relationship
It is well established that expatriates need support from host country nationals (HCNs) to successfully adjust in their new location, and subsequently perform well on their jobs. Drawing on a sample of 149 Indian nurses in the United Kingdom, this two-phase study illustrates how expatriate-HCN interactions unfold over time (two years). To do this, we draw upon social identity theory and show that effective expatriate-HCN relationship building (i.e., perceived categorization and perceived values similarity) lead to HCN support and, subsequently, expatriate adjustment.
Results confirmed that perceptions of categorization and value similarity significantly impacted HCN willingness to offer support. We also find that expatriate age, education level, and time spent in the host country significantly impact adjustment. We discuss theoretical and practical implications and offer suggestions for future research
Development of virtual ophthalmic surgical skills training
Background:
This study aims to assess whether ophthalmic surgical skills can be taught successfully online to a diverse international and interprofessional student group.
Methods:
Mixed methods study involving 20 students and 5 instructors.
Each student completed a pre-session and post-session questionnaire to assess their perceptions regarding online instruction. Changes in questionnaire responses were analysed using Wilcoxon signed rank (SPSS 25). Semi-structured interviews were conducted to assess instructor perceptions towards virtual surgical skills teaching. Thematic analysis was undertaken using NVivo 12.0 software.
Results:
There was a 100% completion rate of pre- and post-session questionnaires.
Prior to the session, lack of instructor supervision and inability to provide constructive feedback were emergent themes from students. Pre-session concerns regarding online delivery: 40% of students thought their view of skills demonstration would be negatively impacted, 60% their level of supervision and 55% their interaction with instructors. Following the session 10%, 15% and 5% held this view respectively. All students were ‘satisfied’ or ‘very satisfied’ regarding the ‘Surgeon’s View’ camera angle as well as the use of breakout rooms. 75% perceived an improvement in their confidence in instrument handling, 80% in cable knot tying and 70% in suture tying.
Overall student rating for the virtual surgical skills session was 8.85 (±1.19) out of 10 (10 being most satisfied).
Conclusions:
We demonstrate that successful delivery of a virtual ophthalmic surgical skills course is feasible. We were able to widen accessibility and participation through virtual delivery, which has future implications for ophthalmic surgical teaching and its reach
Design of an Automatic Traffic Control System with Real Time Vehicle Density Analysis
Growth in developing countries forcefully leads their roads becoming increasingly congested thus bringing traffic to a standstill. There are two major measures that can address this issue viz. manual and automatic approaches. Because of its inefficiency, manual approach is not considered under the preview of this study and the automatic approach, which is the focus of this study, can further be classified into two viz. timer based and density based approaches. Timer based approaches are primarily static in nature and hence cannot consider real time requirements. Incorporating Density analysis on to the problem under preview adds dynamism to the solution and in the proposed study, traffic signals are controlled by considering real time density of vehicles on each roads. After capturing real time images and performing appropriate preprocessing, density of vehicles are measured using Canny Edge detection approach; which is used as a parameter for later decision making. Considering density parameters alone may lead to starvation to certain roads and here in the proposed study, authors consider a weight factor to propose a better solution. A prototype was developed using Arduino mega 2560 board, Webcams and Airplane 9g Mini Servo - SG-90 and led lights and it was observed that the efficacy of the proposed system is higher while comparing it to other prevailing methods
A method for the preparation of cooked-peeled-frozen prawns
Several consignments of cooked-peeled-frozen prawns exported from India were rejected last year due to high total plate count (TPC) at 30°C. The specified temperature of incubation for TPC in our country is 37°C. Hence the effect of incubation at 30 and 37°C on TPC was studied. It is seen that the count is higher on incubation at 30°C. A method for production of cooked-peeled-frozen prawns conforming to the specification for TPC at 30°C is standardized and is reported. It consists of recooking the cooked-peeled prawns followed by packing and freezing without further contamination. The method minimizes batch to batch or sample to sample variation in TPC
Raman scattering mediated by neighboring molecules
Raman scattering is most commonly associated with a change in vibrational state within individual molecules, the corresponding frequency shift in the scattered light affording a key way of identifying material structures. In theories where both matter and light are treated quantum mechanically, the fundamental scattering process is represented as the concurrent annihilation of a photon from one radiation mode and creation of another in a different mode. Developing this quantum electrodynamical formulation, the focus of the present work is on the spectroscopic consequences of electrodynamic coupling between neighboring molecules or other kinds of optical center. To encompass these nanoscale interactions, through which the molecular states evolve under the dual influence of the input light and local fields, this work identifies and determines two major mechanisms for each of which different selection rules apply. The constituent optical centers are considered to be chemically different and held in a fixed orientation with respect to each other, either as two components of a larger molecule or a molecular assembly that can undergo free rotation in a fluid medium or as parts of a larger, solid material. The two centers are considered to be separated beyond wavefunction overlap but close enough together to fall within an optical near-field limit, which leads to high inverse power dependences on their local separation. In this investigation, individual centers undergo a Stokes transition, whilst each neighbor of a different species remains in its original electronic and vibrational state. Analogous principles are applicable for the anti-Stokes case. The analysis concludes by considering the experimental consequences of applying this spectroscopic interpretation to fluid media; explicitly, the selection rules and the impact of pressure on the radiant intensity of this process
- …