Demonstration of event position reconstruction based on diffusion in the NEXT-white detector

Noble element time projection chambers are a leading technology for rare event detection in physics, such as for dark matter and neutrinoless double beta decay searches. Time projection chambers typically assign event position in the drift direction using the relative timing of prompt scintillation and delayed charge collection signals, allowing for reconstruction of an absolute position in the drift direction. In this paper, alternate methods for assigning event drift distance via quantification of electron diffusion in a pure high pressure xenon gas time projection chamber are explored. Data from the NEXT-White detector demonstrate the ability to achieve good position assignment accuracy for both high- and low-energy events. Using point-like energy deposits from 83mKr calibration electron captures (E ∼ 45  keV), the position of origin of low-energy events is determined to 2 cm precision with bias < 1 mm. A convolutional neural network approach is then used to quantify diffusion for longer tracks (E ≥ 1.5  MeV), from radiogenic electrons, yielding a precision of 3 cm on the event barycenter. The precision achieved with these methods indicates the feasibility energy calibrations of better than 1% FWHM at Qββ in pure xenon, as well as the potential for event fiducialization in large future detectors using an alternate method that does not rely on primary scintillation.

206 EXPLORING THE RELATIONSHIP BETWEEN LONELINESS, FRAILTY, AND HEALTHCARE UTILISATION IN IRELAND’S OLDER ADULTS DURING THE COVID-19 PANDEMIC

Background

The COVID-19 pandemic has disproportionately affected older adults, both in morbidity and mortality¹. The effects of the pandemic go beyond contracting the SARS-CoV-2 virus, leading to devastating consequences, particularly for individuals over the age of 60. In Ireland, isolation in older adults was exacerbated by cocooning measures and geographical limitations. The purpose of this study was to explore the relationship between loneliness, frailty, and the utilisation of health services in a sample of sexagenarians in Ireland.

Methods

Adults aged 60–70 attending COVID-19 vaccine appointments at a Level 3 Hospital in Ireland (n = 75) were invited to participate in a 36-item questionnaire. Participants reported demographic information and questions regarding physical well-being, healthcare utilisation, lifestyle and behaviours, and impact of vaccination. The survey also included three validated questionnaires: PRISMA-7 for frailty, SARC-F for sarcopenia, and the UCLA 3-Item Loneliness Scale (UCLA-3ILS).

Results

Of the 75 survey respondents, the mean age was 63.2. 72% (n = 54) identified as female. 28% (n = 21) reported that they had been cocooning during the past year. While 84% (n = 63) of respondents reported that they cancelled routine medical appointments during the pandemic, none reported avoiding attending hospital. Five respondents met the criteria for frailty and four were identified as probable sarcopenic. There was no significant difference (p = 0.64) in mean scores on the UCLA 3-ILS between frail and non-frail individuals. Persons identified as sarcopenic were more likely to have higher scores on the UCLA-3ILS (p = 0.0005).

Conclusion

This research highlights the multifaceted relationship between frailty, loneliness, and healthcare utilisation among Irish adults ages 60–70 during the COVID-19 pandemic. Future research in program, policy, and intervention development for at-risk older adults, particularly those who are frail, sarcopenic, and/or lonely, can work to reduce associated negative outcomes.

Reference

1. Kang S-J and Jung, SI. (2020). Age-Related Morbidity and Mortality among Patients with COVID-19. Infect Chemother., 52(2): 154–164.

Pre-treatment of C57BL6/J mice with the TLR4 agonist monophosphoryl lipid A prevents LPS-induced sickness behaviors and elevations in dorsal hippocampus interleukin-1β, independent of interleukin-4 expression

Peripheral administration of lipopolysaccharide (LPS) elevates production of pro-inflammatory cytokines, and motivates the expression of sickness behaviors. In this study, we tested the ability of an LPS-derived adjuvant, monophosphoryl lipid A (MPLA), to prevent LPS-induced sickness behaviors in a burrowing paradigm. Testing occurred over a three-day period. Animals received a single injection of either MPLA or saline the first two days of testing. On day three, animals received either LPS or saline. Tissue from the dorsal hippocampus was collected for qRT-PCR to assess expression of IL-1β and IL-4. Results indicate that, during the pre-treatment phase, administration of MPLA induces an immune response sufficient to trigger sickness behaviors. However, we observed that animals pre-treated with MPLA for two days were resistant to LPS-induced sickness behaviors on day three. Results from the qRT-PCR analysis indicated that LPS-treated animals pre-treated with MPLA expressed significantly less IL-1β compared to LPS-treated animals pre-treated with saline. However, we did not observe a significant difference in IL-4 expression between groups. Therefore, results indicate that under the given parameters of the study, MPLA pre-treatment protects against LPS-induced sickness behaviors, at least in part, by decreasing expression of the pro-inflammatory cytokine IL-1β.

A pilot clinical trial of oral pentosan polysulfate and oral hydroxyzine in patients with interstitial cystitis

PURPOSE

This pilot study was designed to evaluate the feasibility of a multicenter, randomized, clinical trial in interstitial cystitis (IC). Secondary objectives were to evaluate the safety and efficacy of oral pentosan polysulfate sodium (PPS), hydroxyzine, and the combination to consider their use in a larger randomized clinical trial.

MATERIALS AND METHODS

A 2 x 2 factorial study design was used to evaluate PPS and hydroxyzine. Participants met the National Institutes of Health-National Institute for Diabetes and Digestive and Kidney Diseases criteria for IC and reported at least moderate pain and frequency for a minimum of 6 months before study entry. The primary end point was a patient reported global response assessment. Secondary end points included validated symptom indexes and patient reports of pain, urgency and frequency. The target sample size was 136 participants recruited during 10 months.

RESULTS

A total of 121 (89% of goal) participants were randomized over 18 months and 79% provided complete followup data. The response rate for hydroxyzine was 31% for those treated and 20% for those not treated (p = 0.26). A nonsignificant trend was seen in the PPS treatment groups (34%) as compared to no PPS (18%, p = 0.064). There were no treatment differences for any of the secondary end points. Adverse events were mostly minor and similar to those in previous reports.

CONCLUSIONS

The low global response rates for PPS and hydroxyzine suggest that neither provided benefit for the majority of patients with IC. This trial demonstrated the feasibility of conducting a multicenter randomized clinical trial in IC using uniform procedures and outcomes. However, slow recruitment underscored the difficulties of evaluating commonly available IC drugs.

Intraoperative lower extremity reflex muscle activity as an adjunct to conventional somatosensory-evoked potentials and descending neurogenic monitoring in idiopathic scoliosis

STUDY DESIGN

Lower extremity polysynaptic reflexes and descending neurogenic motor and ascending somatosensory activity were recorded.

OBJECTIVE

Two cases are presented to illustrate the intraoperative use of lower extremity reflex recordings for detecting compromise of spinal cord function.

SUMMARY OF BACKGROUND DATA

Lower extremity reflex processing can be used to measure integrated spinal cord activity, whereas descending neurogenic and ascending somatosensory potentials measure only long tract function.

METHODS

Eight channels of lower extremity polysynaptic reflex activity were recorded simultaneously after unilateral lower extremity mixed nerve stimulation. Sequential descending neurogenic and ascending somatosensory activity was recorded simultaneously with reflex recordings.

RESULTS

In these two patients with idiopathic scoliosis, intraoperative reflexes changed before descending neurogenic and before ascending somatosensory activity changed. High-amplitude synchronous persistent reflex activity correlated with a postoperative neurologic deficit. Low-amplitude asynchronous transient reflex activity was not associated with a postoperative neurologic deficit.

CONCLUSION

Intraoperative lower extremity reflex changes are more sensitive to spinal cord compromise than are changes in long tract function. Lower extremity polysynaptic reflexes monitor the integrated activity of the spinal cord that is responsible for the control of complex motor behavior.

Intraoperative long-latency reflex activity in idiopathic scoliosis demonstrates abnormal central processing. A possible cause of idiopathic scoliosis

Segmental reflex regulation in 37 patients with idiopathic scoliosis and 8 patients with nonidiopathic scoliosis was studied by recording evoked reflex muscle potentials from four muscle groups in each lower extremity during partial neuromuscular blockade. Effects on reflex activity mediated through descending systems arising in the brain stem were investigated by recording from proximal-distal and flexor-extensor muscles. Ipsilateral and contralateral long-latency complex polysynaptic activity was present in all 37 patients with idiopathic scoliosis. This reflex activity was absent in eight nonidiopathic scoliosis patients. Long-latency reflex activity may represent segmental disinhibition. The presence of long-latency reflex activity in patients with idiopathic scoliosis and the absence of this activity in nonidiopathic scoliosis patients with curves of equal magnitude demonstrates that the curve per se is not responsible for the activity. This would imply that abnormal reflex processing may play a role in the development of the spinal deformity in patients with idiopathic scoliosis.

Cognitive strategies of university athletes

Thirty-six college basketball players and skiers, both men and women, were interviewed about their use of cognitive processes to prepare themselves for competition. The interviews examined cognitive techniques for enhancing motor skills and developing competitive strategies. During the interviews the subjects engaged in some of their cognitive preparation strategies and then described the details of these experiences. All athletes reported that the use of cognitive strategies enhanced their performance. Their imagery was rich, detailed, and multisensory. An average of three sensory modalities were present in the imagery. Vision, kinesthesis, and touch were the most common sensory experiences reported, but audition, taste, and smell were also experienced by some athletes. Strong affective states, especially confidence and satisfaction, accompanied the imagery. Individual differences in the imagery used by the athletes were also found and may be related to individual differences in the athletes' cognitive styles.

Preliminary experience with a method of quadricepsplasty in recurrent subluxation of the patella

Nineteen knees were treated for recurrent subluxation or dislocation of the patella by lateral and distal transfer of the vastus medialis with or without release of the lateral retinaculum. Fifty-eight per cent has good or excellent and 42 per cent had poor results after a mean follow-up of twenty-nine months. The factors that predisposed to failure were genu valgum greater than 15 degrees and, to a lesser extent, palpable synovitis associated with symptomatic chondromalacia patellae.