Higher Dose Noninvasive Transcutaneous Auricular Vagus Nerve Stimulation Increases Feeding Volumes and White Matter Microstructural Complexity in Open-Label Study of Infants Slated for Gastrostomy Tube

OBJECTIVE

To determine whether transcutaneous auricular vagus nerve stimulation (taVNS) paired with twice daily bottle feeding increases the volume of oral feeds and white matter neuroplasticity in term-age-equivalent infants failing oral feeds and determined to need a gastrostomy tube.

STUDY DESIGN

In this prospective, open-label study, 21 infants received taVNS paired with 2 bottle feeds for 2 - 3 weeks (2x). We compared 1) increase oral feeding volumes with 2x taVNS and previously reported once daily taVNS (1x) to determine a dose response, 2) number of infants who attained full oral feeding volumes, and 3) diffusional kurtosis imaging and magnetic resonance spectroscopy before and after treatment by paired t tests.

RESULTS

All 2x taVNS treated infants significantly increased their feeding volumes compared with 10 days before treatment. Over 50% of 2x taVNS infants achieved full oral feeds but in a shorter time than 1x cohort (median 7 days [2x], 12.5 days [1x], P < .05). Infants attaining full oral feeds showed greater increase in radial kurtosis in the right corticospinal tract at the cerebellar peduncle and external capsule. Notably, 75% of infants of diabetic mothers failed full oral feeds, and their glutathione concentrations in the basal ganglia, a measure of central nervous system oxidative stress, were significantly associated with feeding outcome.

CONCLUSIONS

In infants with feeding difficulty, increasing the number of daily taVNS-paired feeding sessions to twice-daily significantly accelerates response time but not the overall response rate of treatment. taVNS was associated with white matter motor tract plasticity in infants able to attain full oral feeds.

TRIAL REGISTRATION

Clinicaltrials.gov (NCT04643808).

Impacts of commingling preconditioned and auction-derived beef calves on bovine respiratory disease related morbidity, mortality, and weight gain

Introduction

Stressors predisposing to bovine respiratory disease (BRD) upon arrival in the feedlot, include the ranch to feedlot transition and mixing cattle from multiple sources. Preconditioning (PC) reduces multiple stressors, but commingling PC and auction-derived (AD) calves in a feedlot may increase BRD risk. Our objective was to evaluate PC calf performance over the first 40 days in the feedlot and determine impacts of commingling with varying proportions of AD calves (25, 50, and 75%).

Methods

Calves were either preconditioned at one ranch (n = 250) or mixed-source and bought from a local auction (n = 250). At arrival, calves were assigned into 1 of 5 pens: 100 PC, 75 PC, 50 PC, 25 PC, and 0 PC, reflecting the percentage of PC calves in a 100-head pen.

Results

Over 40 days, morbidity in pen 100 PC was lower compared to 0 PC (24 vs. 50%, P &lt; 0.001) and varied in commingled pens, being highest (63%) in 25 PC and least (21%) in 50 PC (P &lt; 0.05). There were 3 AD deaths in 0 PC and 2 deaths in 25 PC. The AD calves in 0 PC were 3 times more likely to get BRD than PC calves in 100 PC; however, AD calves gained 0.49 kg/d more than PC calves (P &lt; 0.0001). Ignoring pen placement, AD calves were 2.76 times more likely to get BRD but gained 0.27 kg/d more than PC calves (P &lt; 0.0001). Commingling did not affect morbidity of PC (P = 0.5) or AD calves (P = 0.96), implying commingling did not affect health. Calves in 25 PC were 3.39 times more likely to get BRD than those in the 100 PC (P &lt; 0.001). Furthermore, 25 PC calves gained the most (1.08 kg/d), followed by 50 PC (0.62 kg/d) and 75 PC (0.61 kg/d), compared to 100 PC (P &lt; 0.05). Calf weight at arrival modified ADG (P &lt; 0.05).

Discussion

In conclusion, PC calves had lower morbidity over the first 40 days, irrespective of commingling. With larger variations in arrival weight, there was no advantage of PC for ADG in the first 40 days. The unknown weaning strategies and comparable arrival weights of AD calves may have contributed to greater ADG in AD calves.

Effects of feeding graded levels of camelina expeller meal up to 10% of dietary dry matter on production and milk fatty acid profiles in dairy cows

Eight Holstein cows were used in a replicated 4 × 4 Latin square design study to determine the effects of partially replacing canola meal (CM) with 5, 7.5 and 10% camelina expeller meal (CEM) on production and milk fatty acid profiles. Replacing CM with CEM did not affect feed intake and milk yield, but milk contents of fat and protein decreased linearly. Feeding increasing amounts of CEM linearly increased milk contents of C18:2n6, C18:3n3, cis-9, trans-11 CLA, trans-10, cis-12 CLA, and total CLA. Camelina expeller meal can be fed up to 10% of dietary DM without negatively affecting production and can increase milk contents of omega-3 fatty acids.

A Quality Improvement Initiative to Decrease Time to Analgesia in Patients With Sickle Cell and Vaso-Occlusive Crisis: A Population With Disparities in Treatment

Introduction: Vaso-occlusive crises (VOCs) are the leading cause of emergency department (ED) visits and hospitalizations in patients with sickle cell disease (SCD). Timely administration of analgesia, within 60 minutes of patient registration, is the standard of care for SCD patients with VOCs. Patients with VOCs have longer times to initial analgesia compared to similar painful conditions. The primary aim of the project is to have 75% of patients with VOCs receive initial analgesia within 60 minutes of being registered, the current recommended time frame from the National Heart, Lung, and Blood Institute (NHLBI).

Methods: A multi-disciplinary team used quality improvement (QI) methodology to develop a plan involving multiple Plan-Do-Study-Act (PDSA) cycles. A rapid evaluation process was employed which included notification of a patient with a VOC being placed in a room, rapid evaluation by all team members and use of an electronic order set.

Results: The aim was met 72% of the time during our intervention period, compared to 17% pre-intervention. Average time to initial analgesia was decreased from 61 minutes to 42 minutes (p-value < 0.001), while time to disposition was also decreased when time goals were achieved.

Conclusion: Using a rapid evaluation process we were able to decrease time to initial analgesia in a patient population that has previously experienced delays in care and decrease overall time to disposition.

PSVIII-B-4 Differences in Bull Prolificacy and Offspring Body Performance in Western Canadian Multi-Sire Commercial Herds

Beef cattle producers employing multi-sire natural mating systems expect superior breeding and production performance from the bulls. The bulls that sire more healthy calves are more economical considering that the annual maintenance cost for each bull could exceed $2000. Industry benchmarks on bull prolificacy and the production performance of their offspring will enable producers to make better selection and culling decisions. This 3-yr study evaluated 2,130 calves from 62 bulls and 1, 869 cows to assess bull prolificacy and calf production performance in multi-sire breeding pastures – VS (VS1, VS2), OS, CF, KF, DIF, and DEF across Alberta Canada. Calves were matched to bulls using DNA paternity analysis. Prolificacy was assessed among bulls engaged in breeding activities year-over-year. Percentage calves assigned to each sire from sire-progeny matches were assessed within sites over consecutive years (VS1: 11.5 - 46.34%, VS2: 4 - 75%, OS: 2 - 17%, CF: 6 - 33%, KF: 5 - 38%, DIF: 3 - 26%, DEF: 16 - 62%). The differences in body and growth performance of calves were analyzed with linear mixed models. The average birth weight of calves varied by sires (p &lt; 0.05) in VS1 (39.92kg – 42.74kg; P &lt; 0.05), OS (34.09kg–39.49kg), CF (35.72-40.27kg) but not in VS2 (36.35 – 38.02kg; P &gt; 0.05). Similarly, the average calf weaning weights among sires did not differ in VS1 (309.44 – 316.77kg; P = 0.33) but were different (P &lt; 0.05) in OS (219.25 - 236.36kg), CF (216 -243 kg) and KF (178 - 232kg). Differences were also observed in calves' average daily body gain among sires in VS1 (0.93 – 1.14 kg d-1; P &lt; 0.0001). Verifying the sires of calves in multi-sire herds will enable beef producers to make effective management and economic decisions. Measuring the production performance of calves from different bulls is important for the beef industry's profitability and sustainability.

A Comprehensive Review of Vagus Nerve Stimulation for Depression

OBJECTIVES

Vagus nerve stimulation (VNS) is reemerging as an exciting form of brain stimulation, due in part to the development of its noninvasive counterpart transcutaneous auricular VNS. As the field grows, it is important to understand where VNS emerged from, including its history and the studies that were conducted over the past four decades. Here, we offer a comprehensive review of the history of VNS in the treatment of major depression.

MATERIALS AND METHODS

Using PubMed, we reviewed the history of VNS and aggregated the literature into a narrative review of four key VNS epochs: 1) early invention and development of VNS, 2) path to Food and Drug Administration (FDA) approval for depression, 3) refinement of VNS treatment parameters, and 4) neuroimaging of VNS.

RESULTS

VNS was described in the literature in the early 1900s; however, gained traction in the 1980s as Zabara and colleagues developed an implantable neurocybernetic prosthesis to treat epilepsy. As epilepsy trials proceed in the 1990s, promising mood effects emerged and were studied, ultimately leading to the approval of VNS for depression in 2005. Since then, there have been advances in understanding the mechanism of action. Imaging techniques like functional magnetic resonance imaging and positron emission tomography further aid in understanding direct brain effects of VNS.

CONCLUSIONS

The mood effects of VNS were discovered from clinical trials investigating the use of VNS for reducing seizures in epileptic patients. Since then, VNS has gone on to be FDA approved for depression. The field of VNS is growing, and as noninvasive VNS quickly advances, it is important to consider a historical perspective to develop future brain stimulation therapies.

Evaluating Applicant Perceptions of the Impact of Social Media on the 2020-2021 Residency Application Cycle Occurring During the COVID-19 Pandemic: Survey Study

BACKGROUND

Due to challenges related to the COVID-19 pandemic, residency programs in the United States conducted virtual interviews during the 2020-2021 application season. As a result, programs and applicants may have relied more heavily on social media-based communication and dissemination of information.

OBJECTIVE

We sought to determine social media's impact on residency applicants during an entirely virtual application cycle.

METHODS

An anonymous electronic survey was distributed to 465 eligible 2021 Match applicants at 4 University of California Schools of Medicine in the United States.

RESULTS

A total of 72 participants (15.5% of eligible respondents), applying to 16 specialties, responded. Of those who responded, 53% (n=38) reported following prospective residency accounts on social media, and 89% (n=34) of those respondents were positively or negatively influenced by these accounts. The top three digital methods by which applicants sought information about residency programs included the program website, digital conversations with residents and fellows of that program, and Instagram. Among respondents, 53% (n=38) attended virtual information sessions for prospective programs. A minority of applicants (n=19, 26%) adjusted the number of programs they applied to based on information found on social media, with most (n=14, 74%) increasing the number of programs to which they applied. Survey respondents ranked social media's effectiveness in allowing applicants to learn about programs at 6.7 (SD 2.1) on a visual analogue scale from 1-10. Most applicants (n=61, 86%) felt that programs should use social media in future application cycles even if they are nonvirtual.

CONCLUSIONS

Social media appears to be an important tool for resident recruitment. Future studies should seek more information on its effect on later parts of the application cycle and the Match.

Improved Perceptions of Education and Wellness Among General Surgery Residents and Faculty After the Implementation of Outpatient Scribes

BACKGROUND

Recent studies have revealed a high rate of burnout among general surgery (GS) residents. Efforts to design and implement interventions to mitigate fatigue in surgical trainees are critical. Our aim was to assess the educational and wellness impact of outpatient scribe utilization at an academic GS residency program.

METHODS

Electronic surveys were sent to 38 GS residents and 15 faculties who used outpatient scribes for at least 12 months. Questions were scored on a 5-point Likert scale with answers of "Strongly agree" or "Agree" representing affirmative responses.

RESULTS

Thirty residents and 14 faculty completed the survey, resulting in an 83% overall response rate. Twenty-eight (93%) residents and 12 (86%) faculty believed that scribes decrease the daily workload of trainees. Twenty-seven (90%) residents felt that scribes allow them more time to focus on patient care and improve the quality of their surgical education. Ninety-three percent of residents (n = 28) and faculty (n = 13) believed that scribes enhance resident well-being. Twenty-four (80%) residents reported that scribes help improve adherence to duty hour restrictions. Twenty-five (83%) residents believed that utilizing scribes is an effective fatigue mitigation strategy for surgical training programs.

CONCLUSION

Our findings demonstrate that the implementation of an outpatient scribe program at an academic GS residency program may enhance resident education and wellness.

Protein-, polymer-, and silica-based luminescent nanomaterial probes for super resolution microscopy: a review

Super resolution microscopy was developed to overcome the Abbe diffraction limit, which effects conventional optical microscopy, in order to study the smaller components of biological systems. In recent years nanomaterials have been explored as luminescent probes for super resolution microscopy, as many have advantages over traditional fluorescent dye molecules. This review will summarize several different types of nanomaterial probes, covering quantum dots, carbon dots, and dye doped nanoparticles. For the purposes of this review the term "nanoparticle" will be limited to polymer-based, protein-based, and silica-based nanoparticles, including core-shell structured nanoparticles. Luminescent nanomaterials have shown promise as super-resolution probes, and continued research in this area will yield new advances in both materials science and biochemical microscopy at the nanometer scale.

Vomiting in Pediatric Patients

Audience

This classic team-based learning activity is specifically designed for emergency medicine bound medical students and junior residents; however, general pediatrics residents and general medical students may also benefit from this activity. Senior residents and fellows felt that the cases were too basic for them but enjoyed acting as facilitators.

Introduction/Background

Vomiting is a common chief complaint in pediatric patients seen in the Emergency Department. 1-3 Presentations include acute, chronic, and cyclic vomiting, with underlying etiologies such as toxin injection, emotional disturbances, and movement disequilibrium. 1 By understanding these various pathways, it is helpful for physicians to distinguish between gastrointestinal and non-gastrointestinal causes of vomiting. 1 Most cases of vomiting in the pediatric population are self-limiting and require only supportive treatment; however, physicians must be able to recognize red flags associated with vomiting that warrant further evaluation. 1,3 This task may be challenging for medical students and residents in emergency medicine and those with infrequent exposure to pediatric patients. Therefore, this team-based learning activity was developed to help junior learners in differentiating non-emergent and emergent cases of pediatric vomiting. This activity aids learners in formulating a differential based on age, history, and characteristics of vomiting. We also review specific causes of pediatric vomiting that physicians cannot miss including intussusception, pyloric stenosis, malrotation, intestinal atresia, and intracranial pathology.

Educational Objectives

By the end of this TBL session, learners should be able to:Identify red flag symptoms that should prompt referral for urgent intervention by GI or surgical specialists.Recognize how chronicity of the vomiting can alter the differential diagnosisDescribe the varying pathways that can cause nausea and vomiting.Determine the necessity of imaging tests to confirm and possibly treat various causes of vomiting.Interpret imaging studies associated with specific causes of vomiting.

Educational Methods

Classic Team Based Learning (cTBL).

Research Methods

Learners and instructors provided verbal feedback after the session in a large group format. Learners were specifically asked if they felt the session was education, relevant, high-yield and level appropriate. One instructor provided written feedback to the cases as well.

Results

Overall learners and instructors found the session to be engaging, informative and educational. Learners felt that the session was level appropriate for medical students and junior residents. As a result of feedback from the session, several of the iRAT/gRAT questions were adjusted and the group application cases were re-written and implemented.

Discussion

Overall, the educational content and delivery was effective. This session was presented to a group of emergency medicine students, interns and residents. Learners were divided into smaller groups, and each group had a variety of level of learners, including pediatric emergency medicine fellows, present. The fellows, while not necessary to the delivery of the TBL, were extremely helpful in aiding the residents during the session. The final debriefing and answer review were essential to ensure that learners met all educational objectives and fully understood the materials.

Topics

Pediatric vomiting, intussusception, pyloric stenosis, intestinal atresia, malrotation, gastroesophageal reflux disease, superior mesenteric artery (SMA) syndrome, hyperemesis.

Adult cavernous haemangioma of the vocal cords with a unique presentation of acute respiratory distress: a case report

Laryngeal haemangiomas can commonly be seen in children, and first-line treatment is usually propranolol. However, in adults, cavernous haemangioma of the vocal cord(s) is an extremely rare condition - with this being the only published adult case presenting with acute respiratory distress - the mainstay of treatment is surgical excision under microlaryngoscopy. Presentation in adults can be unpredictable, but primarily consists of hoarseness which can be associated with, dyspnoea, dysphagia, and haemoptysis - and in one documented case stenosis of the aero-digestive tract led to death. Due to these airway difficulties, surgery can often prove challenging. In this study, we explore the unusual case of a previously well 71-year-old gentleman presenting to the Emergency Department, with worsening shortness of breath as his primary complaint. Uniquely, in this case, an awake fibre-optic intubation was undertaken to manage the difficult airway and a microlaryngoscopy was performed. A 20x10x15mm lesion was excised, which had characteristics in keeping with a cavernous haemangioma on microscopic examination.

Data Resource: population level family justice administrative data with opportunities for data linkage

INTRODUCTION

Although there has been considerable progress in the use of administrative data for applied health research, the family justice field lags behind. Better use of administrative data are essential to enhance understanding of how the family justice system is working, as well as the characteristics of, and outcomes for, children and families. The Family Justice Data Partnership (FJDP) supports this aim through analyses of core family justice and linked datasets in the SAIL Databank (Secure Anonymised Information Linkage). Cafcass Cymru provide expert advice for children involved in family court proceedings in Wales, ensuring decisions are made in the best interests of the child. We provide an overview of Cafcass Cymru data. We also describe and illustrate linkage to administrative datasets within SAIL.

METHODS

Cafcass Cymru data was transferred to SAIL using a standardised approach to provide de-identified data with Anonymised Linking Fields (ALF) for successfully matched records. Three cohorts were created: all individuals involved in family court applications; all individuals with an ALF allowing subsequent health data linkage; and all individuals with a Residential Anonymised Linking Field (RALF) enabling area-level deprivation analysis.

RESULTS

Cafcass Cymru application data are available for child protection matters (public law, range 2011-2019, n=12,745), and child arrangement disputes (private law, range 2005-2019, n=52,023). An 80% data linkage match rate was achieved. 40% had hospital admissions within two years pre or post application; 54% had emergency department attendances and 61% had outpatient appointments. Individuals were more likely to reside in deprived areas regardless of law type.

CONCLUSION

Cafcass Cymru data can be accessed through the SAIL Databank. The FJDP will continue to enhance research opportunities for all to better understand the family justice system, and outcomes for those involved, such as health and wellbeing for children and family members.

Transcutaneous Auricular Vagus Nerve Stimulation-Paired Rehabilitation for Oromotor Feeding Problems in Newborns: An Open-Label Pilot Study

Neonates born premature or who suffer brain injury at birth often have oral feeding dysfunction and do not meet oral intake requirements needed for discharge. Low oral intake volumes result in extended stays in the hospital (>2 months) and can lead to surgical implant and explant of a gastrostomy tube (G-tube). Prior work suggests pairing vagus nerve stimulation (VNS) with motor activity accelerates functional improvements after stroke, and transcutaneous auricular VNS (taVNS) has emerged as promising noninvasive form of VNS. Pairing taVNS with bottle-feeding rehabilitation may improve oromotor coordination and lead to improved oral intake volumes, ultimately avoiding the need for G-tube placement. We investigated whether taVNS paired with oromotor rehabilitation is tolerable and safe and facilitates motor learning in infants who have failed oral feeding. We enrolled 14 infants [11 premature and 3 hypoxic-ischemic encephalopathy (HIE)] who were slated for G-tube placement in a prospective, open-label study of taVNS-paired rehabilitation to increase feeding volumes. Once-daily taVNS was delivered to the left tragus during bottle feeding for 2 weeks, with optional extension. The primary outcome was attainment of oral feeding volumes and weight gain adequate for discharge without G-tube while also monitoring discomfort and heart rate (HR) as safety outcomes. We observed no adverse events related to stimulation, and stimulation-induced HR reductions were transient and safe and likely confirmed vagal engagement. Eight of 14 participants (57%) achieved adequate feeding volumes for discharge without G-tube (mean treatment length: 16 ± 6 days). We observed significant increases in feeding volume trajectories in responders compared with pre-stimulation (p < 0.05). taVNS-paired feeding rehabilitation appears safe and may improve oral feeding in infants with oromotor dyscoordination, increasing the rate of discharge without G-tube, warranting larger controlled trials.

Evaluating the application of the dual path platform VetTB test for badgers (Meles meles) in the test and vaccinate or remove (TVR) wildlife research intervention project in Northern Ireland

European badgers (Meles meles) are accepted as a wildlife reservoir host for Mycobacterium bovis, which causes bovine tuberculosis (bTB) in the British Isles. The objective of this study was to evaluate the use of Dual Path Platform (DPP) VetTB test (Chembio Diagnostic Systems Inc., Medford, NY, USA) within a Test and Vaccinate or Remove (TVR) wildlife research intervention project. Blood samples were collected from 456 individual badgers, trapped in 2015 and 2016, and tested in the field with DPP VetTB test using whole blood. Additionally, whole blood and serum samples were taken to the laboratory for further DPP VetTB testing and for gamma interferon (IFN-γ) testing. Swabs were taken from the oropharynx and trachea and submitted for bacteriological culture as were swabs from wounds, if present. Field DPP VetTB test positive badgers were euthanised and underwent post-mortem examination and bTB confirmatory testing. The results demonstrated that the test performed as well in the field using whole blood as DPP Vet TB tests in the laboratory using sera or whole blood, and as well as other established tests for M. bovis. Visual assessment of the DPP VetTB test using serum under laboratory conditions showed a high degree of consistency between raters. Using a relative gold standard (parallel interpretation of IFN-γ assay and oropharyngeal/tracheal sample/culture), sensitivity estimates for the DPP VetTB test using sera and whole blood were 0.5 (95%CI 0.34-0.66) and 0.42 (95%CI 0.24-0.66), respectively. Specificity estimates were 0.95 (95%CI 0.93-0.97) for sera and 0.89 (95%CI 0.86-0.92) for whole blood. Parallel interpretation of Band 1 (MPB83) and Band 2 (CFP-10/ESAT-6) of the DPP VetTB test was not superior to interpretation of Band 1 only. The results give confidence in the reliability and reproducibility of the DPP VetTB test for badgers under field conditions and therefore it is considered appropriate for use in a badger bTB control campaign.

Design and validation of a closed-loop, motor-activated auricular vagus nerve stimulation (MAAVNS) system for neurorehabilitation

BACKGROUND

Studies have found that pairing vagus nerve stimulation (VNS) with motor activity accelerates cortical reorganization. This synchronous pairing may enhance motor recovery.

OBJECTIVE

To develop and validate a motor-activated auricular vagus nerve stimulation (MAAVNS) system as a potential neurorehabilitation tool.

METHODS

We created MAAVNS and validated its function as part of an ongoing clinical trial investigating whether taVNS-paired rehabilitation enhances oromotor learning. We compared 3 different MAAVNS EMG electrode configurations in 3 neonates. The active lead was placed over the buccinator muscle. Reference lead placements were orbital, temporal or frontal.

RESULTS

The frontal reference lead produced the highest sensitivity (0.87 ± 0.07 (n = 8)) and specificity (0.64 ± 0.13 (n = 8)). Oral sucking reliably triggers MAAVNS stimulation with high confidence.

CONCLUSION

EMG electrodes placed on target orofacial muscles can effectively trigger taVNS stimuli in infants in a closed loop fashion.

Core Size does not Affect Blinking Behavior of Dye-Doped Ag@SiO2 Core-Shell Nanoparticles for Super-Resolution Microscopy

Dye-doped nanoparticles have been investigated as bright, luminescent labels for super-resolution microscopy via localization methods. One key factor in super-resolution is the size of the luminescent label, which in some cases results in a frame shift between the label target and the label itself. Ag@SiO₂ core–shell nanoparticles, doped with organic fluorophores, have shown promise as super-resolution labels. One key aspect of these nanoparticles is that they blink under certain conditions, allowing super-resolution localization with a single excitation source in aqueous solution. In this work, we investigated the effects of both the Ag core and the silica (SiO₂) shell on the self-blinking properties of these nanoparticles. Both core size and shell thickness were manipulated by altering the reaction time to determine core and shell effects on photoblinking. Size and shell thickness were investigated individually under both dry and hydrated conditions and were then doped with a 1 mM solution of Rhodamine 110 for analysis. We observed that the cores themselves are weakly luminescent and are responsible for the blinking observed in the fully-synthesized metal-enhanced fluorescence nanoparticles. There was no statistically significant difference in photoblinking behavior—both intensity and duty cycle—with decreasing core size. This observation was used to synthesize smaller nanoparticles ranging from approximately 93 nm to 110 nm as measured using dynamic light scattering. The blinking particles were localized via super-resolution microscopy and show single particle self-blinking behavior. As the core size did not impact blinking performance or intensity, the nanoparticles can instead be tuned for optimal size without sacrificing luminescence properties.

Dye-doped nanoparticles have been investigated as bright, luminescent labels for super-resolution microscopy via localization methods.

Comparison of manual and semi-automatic registration in augmented reality image-guided liver surgery: a clinical feasibility study

BACKGROUND

The laparoscopic approach to liver resection may reduce morbidity and hospital stay. However, uptake has been slow due to concerns about patient safety and oncological radicality. Image guidance systems may improve patient safety by enabling 3D visualisation of critical intra- and extrahepatic structures. Current systems suffer from non-intuitive visualisation and a complicated setup process. A novel image guidance system (SmartLiver), offering augmented reality visualisation and semi-automatic registration has been developed to address these issues. A clinical feasibility study evaluated the performance and usability of SmartLiver with either manual or semi-automatic registration.

METHODS

Intraoperative image guidance data were recorded and analysed in patients undergoing laparoscopic liver resection or cancer staging. Stereoscopic surface reconstruction and iterative closest point matching facilitated semi-automatic registration. The primary endpoint was defined as successful registration as determined by the operating surgeon. Secondary endpoints were system usability as assessed by a surgeon questionnaire and comparison of manual vs. semi-automatic registration accuracy. Since SmartLiver is still in development no attempt was made to evaluate its impact on perioperative outcomes.

RESULTS

The primary endpoint was achieved in 16 out of 18 patients. Initially semi-automatic registration failed because the IGS could not distinguish the liver surface from surrounding structures. Implementation of a deep learning algorithm enabled the IGS to overcome this issue and facilitate semi-automatic registration. Mean registration accuracy was 10.9 ± 4.2 mm (manual) vs. 13.9 ± 4.4 mm (semi-automatic) (Mean difference - 3 mm; p = 0.158). Surgeon feedback was positive about IGS handling and improved intraoperative orientation but also highlighted the need for a simpler setup process and better integration with laparoscopic ultrasound.

CONCLUSION

The technical feasibility of using SmartLiver intraoperatively has been demonstrated. With further improvements semi-automatic registration may enhance user friendliness and workflow of SmartLiver. Manual and semi-automatic registration accuracy were comparable but evaluation on a larger patient cohort is required to confirm these findings.

Longitudinal dynamics of herd-level Mycobacterium bovis MLVA type surveillance in cattle in Northern Ireland 2003-2016

Investigating genetically-structured diversity in pathogen populations over time is important to better understand disease maintenance and spread. Herd-level surveillance of Mycobacterium bovis genotypes (multi-locus VNTR analysis types, MLVA types) from all culture-confirmed bovine tuberculosis (TB) herd cases was undertaken in Northern Ireland (NI), generating an unparalleled, longitudinal, population-level 14-year survey for this pathogen. Across this population, 295 genetically-distinct M. bovis MLVA types were identified in the 19,717 M. bovis isolates surveyed. Of these, the most frequent was MLVA type 002 (23.0%); 151 MLVA types were represented more than once, in groups ranging from 2 to 4438 isolates. Only 23 MLVA types were isolated in all 14 years. Investigating inter-annual frequency of M. bovis MLVA types, examples of statistically-significant expansions (MLVA types 002, 004, 006, 009 and 027), contractions (MLVA types 001, 007 and 011) and maintenance (MLVA types 003 and 005) were disclosed, during a period of fluctuating bovine TB herd-level incidence at the NI scale. The fixed period frequency distribution of MLVA types remained highly right-skewed. Novel VNTR copy number variant MLVA types (N = 242; an average of 17 per annum) were identified throughout the survey. The MLVA type distribution in the landscape was not random; MLVA types showed statistically-significant geographical localization and strong spatial associations with Divisional Veterinary Office (DVO) regions. There was also evidence of differential risk of particular MLVA types across breeds (Holstein/Friesian vs. other), age-class, and sex and some evidence of an association between the number of animals testing positive for bovine TB during the disclosing test and particular MLVA types, although there was substantial variation.

A Profile of the SAIL Databank on the UK Secure Research Platform

BACKGROUND

The Secure Anonymised Information Linkage (SAIL) Databank is a national data safe haven of de identified datasets principally about the population of Wales, made available in anonymised form to researchers across the world. It was established to enable the vast arrays of data collected about individuals in the course of health and other public service delivery to be made available to answer important questions that could not otherwise be addressed without prohibitive effort. The SAIL Databank is the bedrock of other funded centres relying on the data for research.

APPROACH

SAIL is a data repository surrounded by a suite of physical, technical and procedural control measures embodying a proportionate privacy-by-design governance model, informed by public engagement, to safeguard the data and facilitate data utility. SAIL operates on the UK Secure Research Platform (SeRP), which is a customisable technology and analysis platform. Researchers access anonymised data via this secure research environment, from which results can be released following scrutiny for disclosure risk. SAIL data are being used in multiple research areas to evaluate the impact of health and social exposures and policy interventions.

DISCUSSION

Lessons learned and their applications include: managing evolving legislative and regulatory requirements; employing multiple, tiered security mechanisms; working hard to increase analytical capacity efficiency; and developing a multi-faceted programme of public engagement. Further work includes: incorporating new data types; enabling alternative means of data access; and developing further efficiencies across our operations.

CONCLUSION

SAIL represents an ongoing programme of work to develop and maintain an extensive, whole population data resource for research. Its privacy-by-design model and UK SeRP technology have received international acclaim, and we continually endeavour to demonstrate trustworthiness to support data provider assurance and public acceptability in data use. We strive for further improvement and continue a mutual learning process with our contemporaries in this rapidly developing field.

Evaluation of the BAX® System for Detection of Salmonella in Selected Foods: Collaborative Study

A multilaboratory study was conducted to compare the automated BAX® System to the standard cultural methods for detection of Salmonella in selected foods. Five food types—frankfurters, raw ground beef, mozzarella cheese, raw frozen tilapia fish, and orange juice—at 3 inoculation levels, were analyzed by each method. A sixth food type, raw ground chicken, was tested using 3 naturally contaminated lots. A total of 16 laboratories representing government and industry participated. In this study, 1386 samples were analyzed, of which 1188 were paired samples and 198 were unpaired samples. Of the 1188 paired samples, 461 were positive by both methods and 404 were negative by both methods. Thirty-seven samples were positive by the BAX System but negative by the standard reference method, and 11 samples were positive by standard cultural method and negative by the BAX System. Of the 198 unpaired samples, 106 were positive by the BAX System and 60 were positive by the standard cultural method. A Chi square analysis of each of the 6 food types, at the 3 inoculation levels tested, was performed. For all foods, the BAX System demonstrated results comparable to those of the standard reference methods based on the Chi square results.

Modulation and study of photoblinking behavior in dye doped silver-silica core-shell nanoparticles for localization super-resolution microscopy

Blinking of fluorescent nanoparticles is a compelling phenomenon with widely debated mechanisms. The ability to inhibit or control blinking is important for applications in the field of optical, semiconductor and fluorescent imaging. Self-blinking nanomaterials are also attractive labels for localization-based super-resolution microscopy. In this work, we have synthesized silver core silica nanoparticles (Ag@SiO2) doped with Rhodamine 110 and studied the parameters that affect blinking. We found that under nitrogen rich conditions the nanoparticles shifted towards higher duty cycles. Also, it was found that hydrated nanoparticles showed a less drastic response to nitrogen rich conditions as compared to dried nanoparticles, indicating that surrounding matrix played a role in the response of nanoparticles to molecular oxygen. Further, the blinking is not a multi-body phenomena, super-resolution localization combined with intensity histogram analysis confirmed that single particles are emitting.

TM3-4 The effect of acetazolamide on intracranial pressure: primary study with prolonged continuous intracranial pressure monitoring

Objectives

Acetazolamide has frequently been used as a first-line treatment for idiopathic Intracranial Hypertension (IIH) and other disorders which lead to a non-acute rise in intracranial pressure (ICP). The effect of acetazolamide has been observed through lumbar puncture, however the effect of acetazolamide on ICP has not been studied in continuous ICP measurement.

Design

A retrospective study of a prospectively built ICP database

Subjects

All patients with continuous ICP monitoring demonstrating 24 hours on and 24 hours off acetazolamide were included in the study.

Methods

Patients median ICP and median pulse amplitude over 24 hour monitoring period on and off Diamox was assessed.

Results

12 patients (9F, 3M) underwent ICP monitoring with data collected during the same admission. 8 patients had IIH, 1 Chiari Malformation, 3 new diagnostic ICP procedures. 10 patients saw a reduction in ICP while on acetazolamide. Overall, patients experienced a Median reduction of 1.14 mmHg (Mean 1.16 mmHg, Range 4.24 to −4.445 mmHg). Patients (n9) who were on ≥1 g of acetazolamide per day experienced a median reduction in ICP of 1.595 mmHg (Mean 1.91 mmHg, Range 4.24–0.5 mmHg).

Conclusions

Our data suggests acetazolamide can reduce ICP quickly following commencement, however this reduction was relatively small. The effect seems greater with a higher dose. Larger numbers of patients are required to gain a greater understanding into the significance of acetazolamide on ICP, particularly the affect at larger doses.

P102 Shunting slit ventricles: a comparison of the parieto-occipital vs frontal approach

Objectives

Slit ventricles can be a challenging target during shunt catheter insertion. Traditionally, the frontal approach has been considered optimal. At this centre, routine use of electromagnetic (EM) stereotatic guidance (StealthTM, Medtronic) has enabled a parieto-occipital burr hole approach to the frontal horns. We compare shunt placement and revisions required for patients with slit ventricles who had shunts inserted via a parieto-occipital (P-O) approach vs. frontal shunt.

Design

Retrospective cohort.

Subjects

Patients with slit ventricles and a ventricular shunt inserted using EM guidance between 2012–2018.

Methods

Slit ventricles were defined as <3 mm (widest). Outcome measures included placement accuary and survival using Kaplan-Meier curve.

Results

82 patients (77F:5M) aged 34.9±10.8 years (mean ±SD) had shunts inserted for IIH (n=63), chiari/syrinx (n=8), congenital hydrocephalus (n=10), pseudomeningocoele (n=1). 35 had primary P-O shunts and 46 had frontal shunts. Overall, 94% of cases had the catheter tip sitting in the frontal horn. The P-O approach was just as accurate as the frontal approach. Eight P-O shunts and 9 frontal shunts required revision over a 60 month periods. There was no significant different in shunt survival between the two approaches (p=0.99).

Conclusions

EM guided placement has enabled the P-O approach to be as safe and with equivalent survival to frontal approach. The accuracy of shunt placement between the two approaches was equivocal.

Investigation of the Reaction Pathways of Biomass-Derived Oxygenate Conversion into Monoalcohols in Supercritical Methanol with CuMgAl-Mixed-Metal Oxide

Reaction pathways for the conversion of cellulose into C₂ -C₆ monoalcohols by supercritical methanol depolymerization and hydrodeoxygenation (SCM-DHDO) over a CuMgAl oxide catalyst have been elucidated using a range of model compounds. SCM-DHDO of intermediate oxygenates including glycerol, methyl lactate, and 1,2-ethanediol produces similar products as those produced from the SCM-DHDO of cellulose. The pathway to C₂ -C₆ monoalcohols occurs through rapid C-C coupling reactions between methanol and diols followed by C-C scission between vicinal alcohol groups to produce two monoalcohols. Methyl-branched monoalcohols are produced through a methyl shift in a secondary diol followed by dehydration. Esters are produced by dehydrogenative coupling between an adsorbed methoxy and a primary alcohol. Both dehydrogenation to a ketone and esterification to a methyl ester are in equilibrium with the corresponding alcohol and were reversible. Dehydration of diols is the slowest observed reaction and not a main pathway to monoalcohols. SCM-DHDO of glucose, dihydroxyacetone, and cellulose all produced similar high molecular weight species indicating that condensation of intermediates can produce undesired side products.

Relationship between residual feed intake and radiated heat loss using infrared thermography in young beef bulls

Residual feed intake (RFI) has been used to select metabolically efficient cattle in beef breeding programs, particularly for sire selection. Adoption of genetic selection using RFI has been limited due to the cost and difficulty of measuring individual feed intake. An alternative method of predicting RFI is to measure radiated heat loss using infrared thermography (IRT) as previous studies have shown promise using this technique to predict metabolic efficiency in mature cows, heifers, and growing bulls. The objective of this study was to explore use of IRT to predict RFI in growing beef bulls. Sixty bulls in each of two years were fed either a forage-based or a grain-based ration. Eye (Ey) and cheek (Ck) surface temperatures were measured using infrared images of the head collected on 16 and 14 sample days in Years 1 and 2, respectively, using a FLIR S60 camera. In Year 2, infrared images were collected continuously using a within-pen FLIR A310 camera system. Bulls were grouped into low, medium and high classes based on ± 0.5 standard deviations of backfat adjusted residual feed intake (RFI_Fat); RFI_Fat values ranged from - 2.27 to + 2.61 kg DM day^-1 (mean=0.0; SD=0.61). Sample day Ey and Ck temperatures were pooled and an average temperature was calculated for individual bulls. Average Ey and Ck temperatures measured using the FLIR S60 and the within-pen camera did not differ significantly across low, medium and high RFI groups (P > 0.05). Temperature deviations associated with extremes in ambient temperature (placing animals outside their thermoneutral zone) or underlying subclinical health problems could bias results in IRT measurements and RFI ranking. Standardization of IRT data and the conditions during measurement is necessary to more accurately assess its potential use to predict RFI.

Energy utilization in cattle with steady state and non-steady state methods: the importance of thermal neutrality

The efficiency by which animals utilize dietary energy is fundamental to the cost of production for protein of animal origin and to the carbon footprint an animal industry has. Hence, the development of cost effective methodology for determining these measurements of efficiency is important. The objective of the present study was to investigate the use of infrared thermography in a rapid, non-steady state method for measuring energy loss in cattle. Data from 241 yearling bulls and steers as well as heifers and mature cows are presented. Infrared images were collected following a 24h feed withdrawal period. The infrared thermal response in these animals was significantly ranked (P < 0.03) with conventional measurements of feed efficiency using residual feed intake values for animals demonstrated to be within a thermal neutral zone. When animals were not within a thermal neutral zone there was no significant ranking. The data suggests that the use of a non-steady state approach using infrared thermography for identifying metabolic efficiency in animals may be a more rapid and less expensive method for identifying differences in energy utilization. The data also demonstrates the importance of maintaining thermal neutrality when measuring metabolic efficiency irrespective of the methodology.