Titin is a nucleolar protein in neurons

Titin is the largest protein produced by living cells and its function as a molecular spring in striated muscle is well characterized (1, 2). Here we demonstrate that titin isoforms in the same size range as found in muscle are prominent neuronal proteins in both the central and peripheral nervous systems, including motor neurons in the spinal cord and brain. Within these neurons, titin localizes to the dense fibrillar component of the nucleolus, the site of ribosomal RNA biogenesis and modification, and a critical site of dysfunction in neurodegenerative disease (3-5). Additionally, we show that the levels of both titin mRNA and protein are altered in the spinal cord of SOD1G93A mice, a commonly used model of amyotrophic lateral sclerosis, indicating that titin mediated nucleolar events may in fact contribute to the pathobiology of disease.

Memory support training and lifestyle modifications to promote healthy aging in persons at risk for Alzheimer's disease: a digital application supported intervention (Brain Boosters)

BACKGROUND

Evidence-based interventions to protect against cognitive decline among older adults at risk for Alzheimer's disease and related dementias (ADRD) are urgently needed. Rehabilitation approaches to support memory and behavioral/lifestyle interventions are recognized as promising strategies for preserving or improving cognitive health, although few previous interventions have combined both approaches. This paper describes the protocol of the Brain Boosters intervention, which synergistically combines training in compensatory and healthy lifestyle behaviors and supports implementation and tracking of new behaviors with a digital application.

METHODS

The study utilizes a single-site, single-blinded, randomized controlled design to compare a structured lifestyle and compensatory aid intervention to an education-only self-guided intervention. We plan to enroll 225 community-dwelling adults (25% from underrepresented groups) aged 65 + who endorse subjective cognitive decline (SCD) and low baseline levels of healthy lifestyle behaviors. Both interventions will be administered in group format, consisting of 15 two-hour classes that occur weekly for ten weeks and taper to bi-monthly and monthly, for an intervention duration of 6 months. Participants in both interventions will receive education about a variety of memory support strategies and healthy lifestyle behaviors, focusing on physical and cognitive activity and stress management. The structured intervention will also receive support in adopting new behaviors and tracking set goals aided by the Electronic Memory and Management Aid (EMMA) digital application. Primary outcomes include global cognition (composite of memory, attention, and executive function tests) and everyday function (Everyday Cognition Questionnaire). Data will be collected at baseline and outcome visits, at approximately 6, 12, and 18 months. Qualitative interviews, self-report surveys (e.g., indicators of self-determination, health literacy) and EMMA data metrics will also be used to identify what components of the intervention are most effective and for whom they work.

DISCUSSION

Successful project completion will provide valuable information about how individuals with SCD respond to a compensation and preventative lifestyle intervention assisted by a digital application, including an understanding of factors that may impact outcomes, treatment uptake, and adherence. The work will also inform development, scaling, and personalization of future interventions that can delay disability in individuals at risk for ADRD.

TRIAL REGISTRATION

ClinicalTrials.gov. (NCT05027789, posted 8/30/2021).

Gut Microbiota to Microglia: Microbiome Influences Neurodevelopment in the CNS

The brain is traditionally viewed as an immunologically privileged site; however, there are known to be multiple resident immune cells that influence the CNS environment and are reactive to extra-CNS signaling. Microglia are an important component of this system, which influences early neurodevelopment in addition to modulating inflammation and regenerative responses to injury and infection. Microglia are influenced by gut microbiome-derived metabolites, both as part of their normal function and potentially in pathological patterns that may induce neurodevelopmental disabilities or behavioral changes. This review aims to summarize the mounting evidence indicating that, not only is the Gut-Brain axis mediated by metabolites and microglia throughout an organism's lifetime, but it is also influenced prenatally by maternal microbiome and diet, which holds implications for both early neuropathology and neurodevelopment.

A protocol for a cluster randomized trial of care delivery models to improve the quality of smoking cessation and shared decision making for lung cancer screening

BACKGROUND

Patients eligible for lung cancer screening (LCS) are those at high risk of lung cancer due to their smoking histories and age. While screening for LCS is effective in lowering lung cancer mortality, primary care providers are challenged to meet beneficiary eligibility for LCS from the Centers for Medicare & Medicaid Services, including a patient counseling and shared decision-making (SDM) visit with the use of patient decision aid(s) prior to screening.

METHODS

We will use an effectiveness-implementation type I hybrid design to: 1) identify effective, scalable smoking cessation counseling and SDM interventions that are consistent with recommendations, can be delivered on the same platform, and are implemented in real-world clinical settings; 2) examine barriers and facilitators of implementing the two approaches to delivering smoking cessation and SDM for LCS; and 3) determine the economic implications of implementation by assessing the healthcare resources required to increase smoking cessation for the two approaches by delivering smoking cessation within the context of LCS. Providers from different healthcare organizations will be randomized to usual care (providers delivering smoking cessation and SDM on site) vs. centralized care (smoking cessation and SDM delivered remotely by trained counselors). The primary trial outcomes will include smoking abstinence at 12-weeks and knowledge about LCS measured at 1-week after baseline.

CONCLUSION

This study will provide important new evidence about the effectiveness and feasibility of a novel care delivery model for addressing the leading cause of lung cancer deaths and supporting high-quality decisions about LCS.

CLINICALTRIALS

GOV PROTOCOL REGISTRATION

NCT04200534 TRIAL REGISTRATION: ClinicalTrials.govNCT04200534.

The influence of frailty on outcomes for older adults admitted to hospital with benign biliary disease: a single-centre, observational cohort study

INTRODUCTION

The prevalence and complications of biliary disease increase with age. Frailty has been associated with adverse outcomes in the hospital setting. We describe the prevalence of frailty in older patients hospitalised with benign biliary disease and its association with duration of hospital stay, and 90-day and 1-year mortality.

METHODS

We performed a retrospective cohort study of patients aged 75 years and over admitted with acute biliary disease between 17 September 2014 and 20 March 2017. Clinical Frailty Scale (CFS) score was recorded on admission.

RESULTS

We included 200 patients with a median age of 82 (75-99) years, 60% were female; 154 (77%) were independent for personal activities of daily living (ADLs) and 99 (49.5%) for instrumental ADLs. Cholecystitis was the most common diagnosis (43%) followed by cholangitis (36%) and pancreatitis (21%). Ninety-nine patients were non frail (NF; CFS 1-4) and 101 were frail (F; CFS 5-9). Some 104 patients received medical treatment only. Surgery was more common in NF patients (11% vs F 2%), percutaneous drainage more frequently performed in F patients (15% vs NF 5%) and endoscopic cholangiopancreatography was similar in both groups (F 32% vs NF 31%). Frailty was associated with worse clinical outcomes in F vs NF: functional deconditioning (34% vs 11%), increased care level (19% vs 3%), length of stay (12 vs 7 days), 90-day mortality (8% vs 3%) and 1-year mortality (48% vs 24%).

CONCLUSIONS

Half of patients in our cohort were frail and spent longer in hospital, were less likely to undergo surgery and were less likely to remain alive at 1 year after discharge.

Intraoperative Code Blue: Improving Teamwork and Code Response Through Interprofessional, In Situ Simulation

INTRODUCTION

An intraoperative cardiac arrest requires perioperative teams to be equipped with the technical skills, nontechnical skills, and confidence to provide the best resuscitative measures for the patient. In situ simulation (simulation conducted in health professionals' work environment, such as a patient care unit, and not in an off-site location) has the potential to improve team performance. The research team assessed the effects of in situ simulation on code response, teamwork, communication, and comfort in intraoperative resuscitations.

METHODS

This study included seven interprofessional teams consisting of RNs, anesthesiologists, surgical technologists, and patient care technicians working in the operating room of a community hospital in New Jersey. The hour-long interdisciplinary simulation training sessions consisted of a code blue scenario run twice; both times video recorded, retrospectively reviewed, and compared to each other. Technical skills were measured by "time-to-tasks"; nontechnical skills were assessed using the Team Emergency Assessment Measure (TEAM) instrument. Self-reported comfort in skills was collected before the simulation program and after completion of the training.

RESULTS

A total of 21 perioperative nurses, 7 anesthesiologists, 7 surgical technologists, and 4 patient care technicians participated from January to April 2021. There was a significant (p < 0.05) decrease in time to compressions (by 14 seconds, 53.5% improvement) and in time to defibrillation (by 49 seconds) between the two simulations. Significant improvements were noted in confidence levels of certain CPR-related technical skills. There were statistically significant improvements in TEAM scores in the two teams that performed lowest in the pre-debrief simulation (p < 0.05).

CONCLUSION

In the operative setting, where time and space for training are limited, in situ simulation training was associated with improvement in technical skills of individuals and teams, with significantly improved teamwork in teams that required the most training. The long-term effects of such training and its effects on patient outcomes require additional research.

Imaging Breast Microcalcifications Using Dark-Field Signal in Propagation-Based Phase-Contrast Tomography

Breast microcalcifications are an important primary radiological indicator of breast cancer. However, microcalcification classification and diagnosis may be still challenging for radiologists due to limitations of the standard 2D mammography technique, including spatial and contrast resolution. In this study, we propose an approach to improve the detection of microcalcifications in propagation-based phase-contrast X-ray computed tomography of breast tissues. Five fresh mastectomies containing microcalcifications were scanned at different X-ray energies and radiation doses using synchrotron radiation. Both bright-field (i.e. conventional phase-retrieved images) and dark-field images were extracted from the same data sets using different image processing methods. A quantitative analysis was performed in terms of visibility and contrast-to-noise ratio of microcalcifications. The results show that while the signal-to-noise and the contrast-to-noise ratios are lower, the visibility of the microcalcifications is more than two times higher in the dark-field images compared to the bright-field images. Dark-field images have also provided more accurate information about the size and shape of the microcalcifications.

Data registration for multi-method qualification of additive manufactured components

This work refines surface registration methods for metrological datasets to improve the multi-method qualification accuracy of additively manufactured (AM) lattices. Datasets acquired from X-ray computed tomography and a coordinate measurement machine of an AM lattice were aligned using derived geometry datum features based on a theoretical supplemental surface definition, which has been established in recent draft standards, but has had limited examination using complex AM structures. A refined sampling registration approach for lattice geometry based on spatially-dependent subsampling is derived and shown to statistically decrease variation between measurement sources. This importance of well-defined sampling practice and definition is highlighted. The applicability of this approach for multi-method qualification of complex AM parts is discussed. This work lays the foundation of utilizing specifications under consideration in a new standard with possible verification techniques that can be employed.

Acute effects of radiation treatment to submental muscles on burrowing and swallowing behaviors in a rat model

Swallowing impairments are a major complication of radiation treatment for oropharyngeal cancers, influencing oral intake and quality of life. The timing and functional consequences of radiation treatment on the swallowing process is not clearly understood. A rodent radiation injury model was used to investigate the onset of oral and pharyngeal dysfunctions in deglutition related to radiation treatment. This study tested the hypothesis that (Wall et al., 2013) alterations in normal biting, licking, and swallowing performance would be measurable following 64Gy of fractionated radiation to the submental muscles; and (Kotz et al., 2004) radiation will affect the animal’s general well-being as measured via burrowing activity. Seven rats received radiation using a clinical linear accelerator given in 8 fractions of 8Gy and another seven animals received sham anesthesia only treatment. Swallowing bolus transit/size was assessed via videofluoroscopy, tongue movement during drinking was measured via an electrical lick sensor, and biting was analyzed from acoustic recordings of a vermicelli pasta test. Burrowing activity was measured by the amount of gravel substrate displaced within a container. Measurements were taken at baseline, during treatment (1–4 weeks), and after completion of treatment (weeks 5 & 6). Decreases in licking frequency and increases in inter-lick interval were observed 5- and 6-weeks post-treatment. Significant decreases in burrowing performance, swallowing frequency, and inter-swallow interval were observed starting the last week of treatment and continuing up to 2-weeks after completion. Results suggest that tongue dysfunction is one of the first treatment related feeding problems to present immediately after the completion of radiation to the submental muscles.

Measuring High-Order Phonon Correlations in an Optomechanical Resonator

We use single photon detectors to probe the motional state of a superfluid ^{4}He resonator of mass ∼1  ng. The arrival times of Stokes and anti-Stokes photons (scattered by the resonator's acoustic mode) are used to measure the resonator's phonon coherences up to the fourth order. By postselecting on photon detection events, we also measure coherences in the resonator when ≤3 phonons have been added or subtracted. These measurements are found to be consistent with predictions that assume the acoustic mode to be in thermal equilibrium with a bath through a Markovian coupling.

Hospital and community care costs for people newly diagnosed of living with HIV in London, UK

This study of people newly diagnosed of living with HIV (ND-PLHIV) calculated the use, cost and outcome of HIV services at a London HIV centre. ND-PLHIV were followed July 2017-October 2018. Hospital data included inpatient days (IP), outpatient (OP), dayward (DW) visits, tests and procedures, and anti-retroviral drugs (ARVs). Community services were recorded in daily diaries. Mean per patient-year (MPPY) use was multiplied by unit costs. 13.6 MPPY (95%CI 12.4-14.9) OP visits, 0.4 MPPY (95%CI 0.1-0.7) IP days, 0.09 MPPY (95%CI 0.01-0.2) DW visits and 4.6 MPPY community services (95%CI 3.4-5.8). Total annual costs per patient-year (CPPY) was £11,483 (95%CI £10,369-12,597): ARVs comprised 63% and community services 2%. White participants used fewer hospital and more community services compared with minority ethnic community (MEC) participants. Costs for White ND-PLHIV was £10,778 CPPY (95%CI £9629-11,928); £13,214 (95%CI £10,656-15,772) for MEC ND-PLHIV (p < 0.06). Annual costs were inversely related to CD4 count at entry (r = -5.58, p = 0.02); mean CD4 count was 476 cells/mm³ (95%CI 422-531) versus 373 cells/mm³ (95%CI 320-425) for White and MEC participants respectively (p = 0.03). Annual costs for ND-PLHIV with CD4 ≤ 350 cells/mm³ was £2478 PPY higher compared with CD4 count >350 cells/mm³ (p = 0.04).

A highly virulent variant of HIV-1 circulating in the Netherlands

We discovered a highly virulent variant of subtype-B HIV-1 in the Netherlands. One hundred nine individuals with this variant had a 0.54 to 0.74 log₁₀ increase (i.e., a ~3.5-fold to 5.5-fold increase) in viral load compared with, and exhibited CD4 cell decline twice as fast as, 6604 individuals with other subtype-B strains. Without treatment, advanced HIV-CD4 cell counts below 350 cells per cubic millimeter, with long-term clinical consequences-is expected to be reached, on average, 9 months after diagnosis for individuals in their thirties with this variant. Age, sex, suspected mode of transmission, and place of birth for the aforementioned 109 individuals were typical for HIV-positive people in the Netherlands, which suggests that the increased virulence is attributable to the viral strain. Genetic sequence analysis suggests that this variant arose in the 1990s from de novo mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence.

K-2 principal knowledge (not leadership) matters for dyslexia intervention

Kindergarten through second-grade elementary schools that best serve students with dyslexia have principals who are knowledgeable about dyslexia and understand the best practices for providing intervention for students with dyslexia. In this study, three styles of leadership were examined to understand the implication that leadership has on intervention for dyslexia: transformational, instructional, and integrated leadership. However, many students in elementary schools have difficulty learning to read despite good leadership by the principal, with 5-20% of students being diagnosed with dyslexia. While these students need phonetic, multisensory intervention to build necessary reading skills, this study found that many principals lack knowledge of this specialized instruction. The purpose of this research was to explore variables that determine the school-based level of appropriate intervention for students with dyslexia. A questionnaire assessing leadership skills, knowledge, and beliefs about dyslexia, preparation in reading disorders and/or dyslexia received from degree programs and professional development, and services provided to students with dyslexia was given to K-2 principals serving in schools across the United States. Results indicated that regardless of leadership style, principals who have greater knowledge and more correct beliefs about dyslexia provide more appropriate school-based services for students with dyslexia. Eight detailed K-2 principal/practitioner recommendations are included based upon this key finding.

Computerised decision support in veterinary medicine, exemplified in a canine idiopathic epilepsy care pathway

Computerised decision support is of emerging and increasing importance in human medicine, but as yet has not been thoroughly applied or evaluated in veterinary medicine. In this essay, the authors report on the first example of a veterinary care pathway, a specific form of computerised decision support, which guides clinicians through a clinical workflow and incorporates individual patient data to inform patient-specific decision recommendations. The veterinary care pathway was designed using consensus statements and specialist neurologist opinion to create a decision support tool concerning canine idiopathic epilepsy. The authors evaluated the care pathway by comparing 35 clinical decisions made by referral clinicians in historical cases of idiopathic epilepsy to decisions recommended by the care pathway when presented with the same clinical case. Their results show that in 77.1% (95% confidence interval [59.9, 89.6]) of cases the care pathway recommended a decision that was the same or similar to a specialist neurologist's decision. Whilst further studies are needed to explore the potential use of such technology in clinical practice, the authors believe this first application provides great promise of a new and alternative method of clinical decision support.

The Seasonal Flux and Fate of Dissolved Organic Carbon Through Bacterioplankton in the Western North Atlantic

The oceans teem with heterotrophic bacterioplankton that play an appreciable role in the uptake of dissolved organic carbon (DOC) derived from phytoplankton net primary production (NPP). As such, bacterioplankton carbon demand (BCD), or gross heterotrophic production, represents a major carbon pathway that influences the seasonal accumulation of DOC in the surface ocean and, subsequently, the potential vertical or horizontal export of seasonally accumulated DOC. Here, we examine the contributions of bacterioplankton and DOM to ecological and biogeochemical carbon flow pathways, including those of the microbial loop and the biological carbon pump, in the Western North Atlantic Ocean (∼39-54°N along ∼40°W) over a composite annual phytoplankton bloom cycle. Combining field observations with data collected from corresponding DOC remineralization experiments, we estimate the efficiency at which bacterioplankton utilize DOC, demonstrate seasonality in the fraction of NPP that supports BCD, and provide evidence for shifts in the bioavailability and persistence of the seasonally accumulated DOC. Our results indicate that while the portion of DOC flux through bacterioplankton relative to NPP increased as seasons transitioned from high to low productivity, there was a fraction of the DOM production that accumulated and persisted. This persistent DOM is potentially an important pool of organic carbon available for export to the deep ocean via convective mixing, thus representing an important export term of the biological carbon pump.

513 THE INFLUENCE OF FRAILTY ON OUTCOMES FOR OLDER ADULTS ADMITTED TO HOSPITAL WITH BENIGN BILIARY AND PANCREATIC DISEASE

Introduction

The prevalence and complications of biliary disease increase with age. We describe the prevalence of frailty in older patients hospitalised with benign biliary and pancreatic disease and establish its association with mortality and duration of hospital stay.

Methods

Prospective observational cohort study of patients aged 75 years and over admitted with a diagnosis of acute biliary disease to a surgical hospital unit between 17/09/2014 and 20/03/2017. Clinical Frailty Scale (CFS) score was recorded on admission.

Results

We included 200 patients with a median age of 82 (75–99), 60% females, 89% lived in their homes, 154 (77%) were independent for personal and 99 (49.5%) for instrumental ADLs, 95% mobilised independently, 17.5% had memory impairment and 8% low mood. Acute cholecystitis was the most common diagnosis (43%) followed by acute cholangitis (36%) and acute pancreatitis (21%). 99 patients were non-frail (NF = CFS 1–4) and 101 were frail (F = CFS ≥5). 104 patients received medical treatment only. Surgery was more common in non-frail (F 2% vs. NF 11%), percutaneous drainage more frequently carried out in frail patients (15% vs. NF 5%) and endoscopic cholangiopancreatography (ERCP) was similar in both groups (F 32%vs. NF 31%). Frailty was associated with worse clinical outcomes in F vs. NF: functional deconditioning (34% vs. 11%), increased care level (19% vs 3%), length of stay (12 vs. 7 days), 90-day (8% vs. 3%) and 1 year-mortality (48% vs. 24%).

Conclusion

Half of patients in our cohort of older adults hospitalised with acute biliary disease were frail. Higher scores of frailty are associated with increased mortality. Compared with non-frail patients, individuals living with frailty were less likely to undergo surgical treatment, spent longer in hospital and were less likely to remain alive at 12 months after hospital discharge.

472 A PILOT COLORECTAL AND GERIATRIC MEDICINE (CGM) CLINIC FOR OLDER, FRAIL PATIENTS REFERRED VIA A 2 WEEK WAIT PATHWAY

Introduction

The two week wait (2ww) colorectal referral pathway was introduced to expedite referrals where cancer is suspected, facilitating prompt diagnosis +/− intervention. Older frail patients are referred via this 2ww pathway even when invasive testing and intervention may not be appropriate. These patients may benefit more from holistic assessment than a universally surgical approach. A Colorectal and Geriatric Medicine (CGM) 2ww referral clinic was piloted, delivered by an urgent referral colorectal specialist nurse and an advanced clinical practitioner in geriatric medicine.

Method

Patients &gt;65 years with a Clinical Frailty Scale (CFS) score of 5 or more at referral were directed to the CGM clinic. A telephone consultation was undertaken, incorporating both 2ww assessment and aspects of comprehensive geriatric assessment.

Results

42-patients were reviewed in the clinic. Mean age was 86.1 years and mean CFS 6. 12-patients underwent CT, and 2 CT virtual colonoscopy. No patients underwent endoscopic investigation and 28-patients declined any investigation. Of those who underwent investigation, no cancers were identified. 1 patient was referred on for endosocpic mucosal resection of polyps. 5-patients had severe diverticular disease, which accounted for their symptoms. Medication recommendations were made for 30-patients, some of which led to symptom cessation. Onward referrals were made to a community geriatrician, diabetes and continence teams, and palliative care specialists. 9-patients were identified as meeting criteria for advance care planning. This was commenced during the consultation and communicated back to the referring clinician for further action.

Conclusion

Older, frail patients are often not able, nor wish to undergo, invasive investigations but should not be disadvantaged or delayed in their pathway. Further work is needed to determine the most appropriate referral pathway for this group of patients. Holistic assessment that leads to improvement in symptoms and future planning may not be achievable through a solely surgical assessment.

Adsorption trajectories of nonspherical particles at liquid interfaces

The adsorption of colloidal particles at liquid interfaces is of great importance scientifically and industrially, but the dynamics of the adsorption process is still poorly understood. In this paper we use a Langevin model to study the adsorption dynamics of ellipsoidal colloids at a liquid interface. Interfacial deformations are included by coupling our Langevin dynamics to a finite element model while transient contact line pinning due to nanoscale defects on the particle surface is encoded into our model by renormalizing particle friction coefficients and using dynamic contact angles relevant to the adsorption timescale. Our simple model reproduces the monotonic variation of particle orientation with time that is observed experimentally and is also able to quantitatively model the adsorption dynamics for some experimental ellipsoidal systems but not others. However, even for the latter case, our model accurately captures the adsorption trajectory (i.e., particle orientation versus height) of the particles. Our study clarifies the subtle interplay between capillary, viscous, and contact line forces in determining the wetting dynamics of micron-scale objects, allowing us to design more efficient assembly processes for complex particles at liquid interfaces.

Tolerability of four-drug antiretroviral combination therapy in primary HIV-1 infection

Objectives

Rapid initiation of antiretroviral therapy (ART) is important for individuals with high baseline viral loads, such as in primary HIV‐1 infection (PHI). Four‐drug regimens are sometimes considered; however, data are lacking on tolerability. We aimed to evaluate the tolerability of four‐drug regimens used in the Research in Viral Eradication of HIV‐1 Reservoirs (RIVER) study.

Methods

At enrolment, ART‐naïve adult participants or those newly commenced on ART were initiated or intensified to four‐drug regimens within 4 weeks of PHI. Rapid start was defined as pre‐confirmation or ≤ 7 days of confirmed diagnosis. Primary and secondary outcomes were patient‐reported adherence measured by 7‐day recall and regimen switches between enrolment and randomization, respectively.

Results

Overall, 54 men were included: 72.2% were of white ethnicity, with a median age of 32 years old, 42.6% had a viral load of ≥ 100 000 HIV‐1 RNA copies/mL, and in 92.6% sex with men was the mode of acquisition of HIV‐1. Twenty (37%) started a four‐drug regimen and 34 (63%) were intensified. Rapid ART initiation occurred in 28%, 100% started in ≤ 4 weeks. By weeks 4, 12, and 24, 37.0%, 69.0%, and 94.0% were undetectable (viral load < 50 copies/mL), respectively. Adherence rates of 100% at weeks 4, 12, 22 and 24 were reported in 88.9%, 87.0%, 82.4% and 94.1% of participants, respectively. Five individuals switched to three drugs, four changed their regimen constituents, and two switched post‐randomization.

Conclusions

Overall, four‐drug regimens were well tolerated and had high levels of adherence. Whilst their benefit over three‐drug regimens is lacking, our findings should provide reassurance if a temporarily intensified regimen is clinically indicated to help facilitate treatment.

Rapid photoacclimation during episodic deep mixing augments the biological carbon pump

Episodic deep mixing events are one component of the biological carbon pump that physically transports organic carbon into the mesopelagic. Episodic deep mixing also disrupts summertime thermal stratification thereby changing the light field and nutrient concentrations available for phytoplankton growth. Phytoplankton survival and growth below the mixed layer following restratification depends on how rapidly cells can employ a variety of photoacclimation processes in response to the environmental changes. To compare the relative timescales of summertime episodic deep mixing events with the timescales of phytoplankton photoacclimation processes, we first analyzed autonomous float data to survey the frequency and magnitude of deep mixing events in the western North Atlantic Ocean. Next, we simulated a sustained deep mixing event in the laboratory and measured rates of acclimation processes ranging from light harvesting to growth in a model diatom and green alga. In both algae increases in chlorophyll (Chl) were coupled to growth, but growth of the green alga lagged the diatom by about a day. In float profiles, significant increases in Chl and phytoplankton carbon (C _phyto) were detected below the mixed layer following episodic deep mixing events. These events pose a previously unrecognized source of new production below the mixed layer that can significantly boost the amount of carbon available for export to the deep ocean.

Mental Well-Being in UK Higher Education During Covid-19: Do Students Trust Universities and the Government?

This paper draws upon the concept of recreancy to examine the mental well-being of university students during the Covid-19 pandemic. Briefly, recreancy is loss of societal trust that results when institutional actors can no longer be counted on to perform their responsibilities. Our study of mental well-being and recreancy focuses on the role of universities and government regulators within the education sector. We surveyed 600 UK students attending 161 different public higher education providers in October 2020 during a time when many UK students were isolated in their residences and engaged in online learning. We assessed student well-being using the Short Warwick-Edinburgh Mental Well-being Scale (scored 7–35) and found the mean score to be 19.9 [95% confidence interval (CI) 19.6, 20.2]. This level of well-being indicates that a significant proportion of UK students face low levels of mental well-being. Structural equation modeling (SEM) analysis indicates that high recreancy—measured as a low trust in universities and the government—is associated with low levels of mental well-being across the student sample. While these findings are suggestive, they are also important and we suggest that government and university leaders should not only work to increase food and housing security during the Covid-19 pandemic, but also consider how to combat various sector trends that might intensify recreancy.

In Situ Estimates of Net Primary Production in the Western North Atlantic With Argo Profiling Floats

The ¹⁴C incubation method for net primary production (NPP) has limited spatial/temporal resolution, while satellite approaches cannot provide direct information at depth. With chlorophyll-a and backscatter measurements from BGC-Argo floats, we quantified year-round NPP in the western North Atlantic Ocean using both the Carbon-based Productivity Model (CbPM) and Photoacclimation Productivity Model (PPM). Comparison with NPP profiles from ¹⁴C incubation measurements showed advantages and limitations of both models. CbPM reproduced the magnitude of NPP in most cases. However, in the summer the CbPM-based NPP had a large peak in the subsurface, which was an artifact from the subsurface chlorophyll maximum caused by photoacclimation. PPM avoided the artifacts from photoacclimation, but the magnitude of PPM-derived NPP was smaller than the ¹⁴C result. Different NPP distribution patterns along a North-South transect in the Western North Atlantic Ocean were observed, including higher winter NPP/lower summer NPP in the south, timing differences in NPP seasonal phenology, and different NPP depth distribution patterns in the summer months. Using a 6-months record of concurrent oxygen and bio-optical measurements from two Argo floats, we also demonstrated the ability of Argo floats to obtain estimates of the net community production to NPP ratio, ranging from 0.3 in July to -1.0 in December 2016. Our results highlight the utility of float bio-optical profiles and indicate that environmental conditions (e.g., light availability, nutrient supply) are major factors controlling the seasonality and spatial (horizontal and vertical) distributions of NPP in the western North Atlantic Ocean.

Combined HIV Adolescent Prevention Study (CHAPS): comparison of HIV pre-exposure prophylaxis regimens for adolescents in sub-Saharan Africa-study protocol for a mixed-methods study including a randomised controlled trial

BACKGROUND

HIV remains a major public health issue, especially in Eastern and Southern Africa. Pre-exposure prophylaxis is highly effective when adhered to, but its effectiveness is limited by cost, user acceptability and uptake. The cost of a non-inferiority phase III trial is likely to be prohibitive, and thus, it is essential to select the best possible drug, dose and schedule in advance. The aim of this study, the Combined HIV Adolescent PrEP and Prevention Study (CHAPS), is to investigate the drug, dose and schedule of pre-exposure prophylaxis (PrEP) required for the protection against HIV and the acceptability of PrEP amongst young people in sub-Saharan Africa, and hence to inform the choice of intervention for future phase III PrEP studies and to improve strategies for PrEP implementation.

METHODS

We propose a mixed-methods study amongst young people aged 13-24 years. The first component consists of qualitative research to identify the barriers and motivators towards the uptake of PrEP amongst young people in South Africa, Uganda and Zimbabwe. The second component is a randomised clinical trial (ClinicalTrials.gov NCT03986970, June 2019) using a novel ex vivo HIV challenge method to investigate the optimal PrEP treatment (FTC-TDF vs FTC-TAF), dose and schedule. We will recruit 144 amongst HIV-negative uncircumcised men aged 13-24 years from voluntary male medical circumcision clinics in two sites (South Africa and Uganda) and randomise them into one of nine arms. One group will receive no PrEP prior to surgery; the other arms will receive either FTC-TDF or FTC-TAF, over 1 or 2 days, and with the final dose given either 6 or 20 h prior to surgery. We will conduct an ex vivo HIV challenge on their resected foreskin tissue.

DISCUSSION

This study will provide both qualitative and quantitative results to help decide the optimum drug, dose and schedule for a future phase III trial of PrEP. The study will also provide crucial information on successful strategies for providing PrEP to young people in sub-Saharan Africa.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03986970 . Registered on 14 June 2019.

Integrating connectivity theory within watershed modelling part II: Application and evaluating structural and functional connectivity

Integrating connectivity theory within watershed modelling is one solution to overcome spatial and temporal shortcomings of sediment transport prediction, and Part I and II of these companion papers advance this overall goal. In Part II of these companion papers, we investigate sediment flux via connectivity formula discretized over many catchments and then integrated via sediment routing; and we advance model evaluation technology by using hysteresis of sensor data. Model evaluation with hysteresis indices provides nearly a 100% increase in model statistics. Hysteresis loop evaluation shows a shift from near linear behavior at low to moderate events and then clock-wise loops for larger events indicating the importance of proximal sediment sources. Catchment-scale sediment flux varies as function of the probability of timing and extent of connectivity of an individual catchment. Watershed-scale sediment flux shows self-similarity for the main stem of the river channel as the 181 catchments are integrated moving down gradient. Sediment flux varies from event-to-event as a function of the most sensitive connected pathways, including ephemeral gullies and roadside ditches in this basin. These sensitive pathways contribute disproportionately large amounts to overall sediment yield regardless of the total rainfall depth. Prediction requires the connectivity formula, erosion formula and sediment routing formula; and the probability of connectivity alone was a poor predictor for sediment transport. The result highlights the importance of coupling connectivity simulations with sediment transport formula, and our method provides one such approach.

Integrating connectivity theory within watershed modelling part I: Model formulation and investigating the timing of sediment connectivity

Integrating connectivity theory within watershed modelling is one solution to overcome spatial and temporal shortcomings of sediment transport prediction, and Part I and II of these companion papers advance this overall goal. In Part I of these companion papers, we present the theoretical development of probability of connectivity formula considering connectivity's magnitude, extent, timing and continuity that can be applied to watershed modelling. Model inputs include a high resolution digital elevation model, hydrologic watershed variability, and field connectivity assessments. We use the model to investigate the dependence of the probability of connected timing and spatial connectivity on sediment transport predictors. Results show the spatial patterns of connectivity depend on both structural and functional characteristics of the catchment, such as hillslope gradient, upstream contributing area, soil texture, and stream network configuration (structural) and soil moisture content and runoff generation (functional). Spatial connectivity changes from catchment-to-catchment as a function of soil type and drainage area; and it varies from event-to-event as a function of runoff depth and soil moisture conditions. The most sensitive connected pathways provide the stencil for the probability of connectivity, and pathways connected from smaller hydrologic events are consistently reconnected and built upon during larger hydrologic events. Surprisingly, we find the probability of connected timing only depends on structural characteristics of catchments, which are considered static over the timescales analyzed herein. The timing of connectivity does not statistically depend on functional characteristics, which relaxes the parameterization across events of different magnitudes. This result occurs because the pathway stencil accumulates sediment from adjacent soils as flow intensity increases, but this does not statistically shift the frequency distribution.

The impact of the implementation of a mobile stroke unit on a stroke cohort

BACKGROUND

Mobile stroke units (MSUs), specialized ambulances with a built-in computed tomography (CT) scanner and telemedicine connected stroke team, have been on the rise in recent years largely due to the 'time is brain' concept. We aim to report our initial experience since establishing our MSU, the first unit in the Tri-state area, and assess its impact on the stroke standards of care timeline.

METHODS

We conducted a retrospective analysis of a prospectively maintained database of all MSU dispatched cases from August 2019 to March 2020.

RESULTS

Of 195 MSU responses, 101 were treated and transported by the MSU. The mean time (hr:mm) of dispatch to scene arrival was 0:07+0:03, scene arrival to CT start was 0:10+0:03, CT start to teleneuro start was 0:05+0:03, teleneuro start to scene departure was 0:06+0:05, scene departure to hospital arrival was 0:12+0:06, and hospital arrival to arterial puncture was 2:59+1:01. The mean time of dispatch to arterial puncture was 3:34+1:02. The mean teleneuro consult duration was 0:04+0:02. The mean time of last know well (LKW) to tPA administration was 1:28+0:48 with 4 (57.1 %) patients receiving tPA within 60 min of LKW and 5 (71.4 %) patients receiving tPA within 90 min. The mean time of dispatch to tPA was 0:37+0:09 and scene arrival to tPA administration was 0:28+0:07.

CONCLUSION

MSUs may expedite each step along the stroke standards of care. In theory, this should drastically improve functional outcomes. However, the impact on functional outcomes or reductions in stroke-related morbidity is still unknown.

An Infant Sonicguide Intervention Program for a Child with a Visual Disability

The purpose of the study reported here was to teach a preschool child with a visual impairment and significant developmental delay to reach out and locate objects systematically and accurately from a sitting position and to locate and move toward given objects in the environment using the Infant Sonicguide. Although the child achieved the first goal, time constraints prevented him from reaching the second goal.

Quantification of nitrate fate in a karst conduit using stable isotopes and numerical modeling

Nitrate (NO₃⁻) fate estimates in turbulent karst pathways are lacking due, in part, to the difficulty of accessing remote subsurface environments. To address this knowledge and methodological gap, we collected NO₃⁻, δ¹⁵N_NO3, and δ¹⁸O_NO3 data for 65 consecutive days, during a low-flow period, from within a phreatic conduit and its terminal end-point, a spring used for drinking water. To simulate nitrogen (N) fate within the karst conduit, the authors developed a numerical model of NO₃⁻ isotope dynamics. During low-flow, data show an increase in NO₃⁻ (from 1.78 to 1.87 mg N L^-1; p < 10^-4) coincident with a decrease in δ¹⁵N_NO3 (from 7.7 to 6.8‰; p < 10^-3) as material flows from within the conduit to the spring. Modeling results indicate that the nitrification of isotopically-lighter ammonium (δ¹⁵N_NH4) acts as a mechanism for an increase in NO₃⁻ that coincides with a decrease in δ¹⁵N_NO3. Further, numerical modeling assists with quantifying isotopic overprinting of nitrification on denitrification (i.e., coincident NO₃⁻ production during removal) by constraining the rates of the two processes. Modeled denitrification fluxes within the karst conduit (67.0 ± 19.0 mg N m^-2 d^-1) are an order-of-magnitude greater than laminar ground water pathways (1-10 mg N m^-2 d^-1) and an order-of-magnitude less than surface water systems (100-1000 mg N m^-2 d^-1). In this way, karst conduits are a unique interface of the processes and gradients that control both surface and ground water end-points. This study shows the efficacy of ambient N stable isotope data to reflect N transformations in subsurface karst and highlights the usefulness of stable isotopes to assist with water quality numerical modeling in karst. Lastly, we provide a rare, if not unique, estimate of N fate in subsurface conduits and provide a counterpoint to the paradigm that karst conduits are conservative source-to-sink conveyors.

Enzymatic-Ultraviolet Method for Measuring Lactose in Milk: Collaborative Study

Collaborators in 8 dairy and food industry laboratories performed one lactose determination on each of 8 unknown samples of milk, lowfat milk, or skim milk, as 3 pairs of blind duplicates. Two known samples were provided to gain experience prior to analysis of the unknown samples. All of the above samples were also analyzed for lactose content by the official AOAC gravimetric method (16.507) by a commercial laboratory. From the overall mean of results on all samples, determinations by the enzymatic method averaged 0.49% lower than by the AOAC method. This difference was significant by the t-test (P = 0.05), which indicated a lack of agreement between the compared methods in determining lactose content. Standard deviations were similar for the 3 sets of blind duplicates which ranged between 3.67 and 4.55% lactose content. F-values revealed that variations between means obtained by laboratories differed significantly as compared with variations within laboratory means. The method has been adopted official first action.

Phytoplankton Growth and Productivity in the Western North Atlantic: Observations of Regional Variability From the NAAMES Field Campaigns

The ability to quantify spatio-temporal variability in phytoplankton growth and productivity is essential to improving our understanding of global carbon dynamics and trophic energy flow. Satellite-based observations offered the first opportunity to estimate depth-integrated net primary production (NPP) at a global scale, but early modeling approaches could not effectively address variability in algal physiology, particularly the effects of photoacclimation on changes in cellular chlorophyll. Here, a previously developed photoacclimation model was used to derive depth-resolved estimates of phytoplankton division rate (μ) and NPP. The new approach predicts NPP values that closely match discrete measurements of 14C-based NPP and effectively captured both spatial and temporal variability observed during the four field campaigns of the North Atlantic Aerosols and Marine Ecosystems Study (NAAMES). We observed favorable growth conditions for phytoplankton throughout the annual cycle in the subtropical western North Atlantic. As a result, high rates of μ are sustained year-round resulting in a strong coupling between growth and loss processes and a more moderate spring bloom compared to the high-latitude subarctic region. Considerable light limitation was observed in the subarctic province during the winter, which resulted in divergent growth dynamics, stronger decoupling from grazing pressure and a taxonomically distinct phytoplankton community. This study demonstrates how detailed knowledge of phytoplankton division rate furthers our understanding of global carbon cycling by providing insight into the resulting influence on phytoplankton taxonomy and the loss processes that dictate the fate of fixed carbon.

Propagation-based x-ray phase-contrast tomography of mastectomy samples using synchrotron radiation

PURPOSE

Propagation-based phase-contrast computed tomography (PB-CT) is a method for three-dimensional x-ray imaging that utilizes refraction, as well as absorption, of x rays in the tissues to increase the signal-to-noise ratio (SNR) in the resultant images, in comparison with equivalent conventional absorption-only x-ray tomography (CT). Importantly, the higher SNR is achieved without sacrificing spatial resolution or increasing the radiation dose delivered to the imaged tissues. The present work has been carried out in the context of the current development of a breast CT imaging facility at the Australian Synchrotron.

METHODS

Seven unfixed complete mastectomy samples with and without breast cancer lesions have been imaged using absorption-only CT and PB-CT techniques under controlled experimental conditions. The radiation doses delivered to the mastectomy samples during the scans were comparable to those approved for mammographic screening. Physical characteristics of the reconstructed images, such as spatial resolution and SNR, have been measured and compared with the results of the radiological quality assessment of the complete absorption CT and PB-CT image stacks.

RESULTS

Despite the presence of some image artefacts, the PB-CT images have outperformed comparable absorption CT images collected at the same radiation dose, in terms of both the measured objective image characteristics and the radiological image scores. The outcomes of these experiments are shown to be consistent with predictions of the theory of PB-CT imaging and previous reported experimental studies of this imaging modality.

CONCLUSIONS

The results presented in this paper demonstrate that PB-CT holds a high potential for improving on the quality and diagnostic value of images obtained using existing medical x-ray technologies, such as mammography and digital breast tomosynthesis (DBT). If implemented at suitable synchrotron imaging facilities, PB-CT can be used to complement existing imaging modalities, leading to more accurate breast cancer diagnosis.

Changing trends in mortality in systemic lupus erythematosus? An analysis of SLE inpatient mortality at University Hospital Coventry and Warwickshire NHS Trust from 2007 to 2016

The aim of this study was to determine the causes of mortality in patients with systemic lupus erythematosus (SLE) at the University Hospital Coventry and Warwickshire (UHCW) NHS Trust over a 10 year period. This was a retrospective study of patients who had died in UHCW NHS Trust between 2007 and 2016, where SLE or lupus was mentioned on the death certificate. Ethics approval was obtained from the Research and Development. We identified 22 patients out of 1979 admissions with SLE who had died during the period between 2007 and 2016, 7 of these patients were under 50 years of age. The leading cause of death was infection with pneumococcus being associated with two deaths. Active disease was associated with younger age at death. Median age at death was 58.5 years, with median duration of disease of 14.5 years. Constitutional and mucocutaneous features were the most common items scoring on disease activity, seen in 68.2% and 45.45%, respectively. We identified three patients with biopsy proven lupus nephritis and one patient with CNS lupus. Surprisingly, none of the patients died because of vascular problems. The study suggests a changing trend in SLE mortality with none of the deaths in this cohort being due to cardiovascular or cerebrovascular disease. Infection continues to be the biggest reason for mortality in this cohort and greater emphasis is needed on vaccination for preventable infections like pneumococcus.

Flow cytometric methodology for the detection of de novo human T-cell leukemia virus -1 infection in vitro: A tool to study novel infection inhibitors

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MT-2 cells express more Tax, gp46 and p19 than HUT102′s.

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HUT78 cells express higher levels of the HTLV-1 permissive receptors neuropilin and GLUT-1 than CEM or JURKAT.

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Irradiation does not eliminate all MT-2 donor cells in HTLV-1 co-culture protocols.

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Flow cytometry and Lt-4 anti-tax antibody can detect de novo HTLV-1 infection at early time points.

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Cytochalasin B and sodium valproate inhibit HTLV-1 infection at early time points.

Methodology to detect and study de novo human T-cell leukemia virus (HTLV)-1 infection is required to further our knowledge of the viruses’ mechanisms of infection and to study potential therapeutic interventions. Whilst methodology currently exists, utilisation of an anti-Tax antibody to detect de novo Tax expression in permissive cells labelled with cell tracker allowing for the detection by flow cytometry of new infection after co-culture with donor cell lines productively infected with HTLV-1 is an alternative strategy. Using this methodology, we have been able to detect de novo infection of the T cell line HUT78 following co-culture with the productively infected HTLV-1 donor cell line MT-2 and to confirm that infection can be effectively blocked with well characterised infection inhibitors. This methodology will benefit experimental studies examining HTLV infection in vitro and may aid identification of therapeutic agents that block this process.