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Nucleobases are nitrogenous bases composed of monomers that are a major constituent of RNA and DNA, which are an essential part of any cellular life on the Earth. The search for nucleobases in the interstellar medium remains a major challenge, however, the recent detection of nucleobases in meteorite samples and laboratory synthesis in simulated analogue experiments have confirmed their abiotic origin and a possible route for their delivery to the Earth. Nevertheless, cellular life is based on the interacting network of complex structures, and there is substantial lack of information on the possible routes by which such ordered structures may be formed in the prebiotic environment. In the current study, we present the evidence for the synthesis of complex structures due to shock processing of nucleobases. The nucleobases were subjected to the reflected shock temperature of 3500–7000 K (estimated) and pressure of about 15–34 bar for over ~2 ms timescale. Under such extreme thermodynamic conditions, the nucleobases sample experiences superheating and subsequent cooling. Electron microscopic studies of shock processed residue show that nucleobases result in spontaneous formation of complex structures when subjected to extreme conditions of shock. These results suggest that impact shock processes might have contributed to the self-assembly of biologically relevant structures and the origin of life.
Diet is a modifiable risk factor for chronic disease and a potential modulator of telomere length (TL). The study aim was to investigate associations between diet quality and TL in Australian adults after a 12-week dietary intervention with an almond-enriched diet (AED). Participants (overweight/obese, 50–80 years) were randomised to an AED (n 62) or isoenergetic nut-free diet (NFD, n 62) for 12 weeks. Diet quality was assessed using a Dietary Guideline Index (DGI), applied to weighed food records, that consists of ten components reflecting adequacy, variety and quality of core food components and discretionary choices within the diet. TL was measured by quantitative PCR in samples of lymphocytes, neutrophils, and whole blood. There were no significant associations between DGI scores and TL at baseline. Diet quality improved with AED and decreased with NFD after 12 weeks (change from baseline AED + 9·8 %, NFD − 14·3 %; P < 0·001). TL increased in neutrophils (+9·6 bp, P = 0·009) and decreased in whole blood, to a trivial extent (–12·1 bp, P = 0·001), and was unchanged in lymphocytes. Changes did not differ between intervention groups. There were no significant relationships between changes in diet quality scores and changes in lymphocyte, neutrophil or whole blood TL. The inclusion of almonds in the diet improved diet quality scores but had no impact on TL mid-age to older Australian adults. Future studies should investigate the impact of more substantial dietary changes over longer periods of time.
Antisaccade tasks can be used to index cognitive control processes, e.g. attention, behavioral inhibition, working memory, and goal maintenance in people with brain disorders. Though diagnoses of schizophrenia (SZ), schizoaffective (SAD), and bipolar I with psychosis (BDP) are typically considered to be distinct entities, previous work shows patterns of cognitive deficits differing in degree, rather than in kind, across these syndromes.
Large samples of individuals with psychotic disorders were recruited through the Bipolar-Schizophrenia Network on Intermediate Phenotypes 2 (B-SNIP2) study. Anti- and pro-saccade task performances were evaluated in 189 people with SZ, 185 people with SAD, 96 people with BDP, and 279 healthy comparison participants. Logistic functions were fitted to each group's antisaccade speed-performance tradeoff patterns.
Psychosis groups had higher antisaccade error rates than the healthy group, with SZ and SAD participants committing 2 times as many errors, and BDP participants committing 1.5 times as many errors. Latencies on correctly performed antisaccade trials in SZ and SAD were longer than in healthy participants, although error trial latencies were preserved. Parameters of speed-performance tradeoff functions indicated that compared to the healthy group, SZ and SAD groups had optimal performance characterized by more errors, as well as less benefit from prolonged response latencies. Prosaccade metrics did not differ between groups.
With basic prosaccade mechanisms intact, the higher speed-performance tradeoff cost for antisaccade performance in psychosis cases indicates a deficit that is specific to the higher-order cognitive aspects of saccade generation.
Feeding difficulty is a known complication of congenital heart surgery. Despite this, there is a relative sparsity in the available data regarding risk factors, incidence, associated symptoms, and outcomes.
In this retrospective chart review, patients aged 0–18 years who underwent congenital heart surgery at a single institution between January and December, 2017 were reviewed. Patients with feeding difficulties before surgery, multiple surgeries, and potentially abnormal recurrent laryngeal nerve anatomy were excluded. Data collected included patient demographics, feeding outcomes, post-operative symptoms, flexible nasolaryngoscopy findings, and rates of readmission within a 1-year follow-up period. Multivariable regression analyses were performed to evaluate the risk of an alternative feeding plan at discharge and length of stay.
Three-hundred and twenty-six patients met the inclusion criteria for this study. Seventy-two (22.09%) were discharged with a feeding tube and 70 (97.22%) of this subgroup were younger than 12 months at the time of surgery. Variables that increased the risk of being discharged with a feeding tube included patient age, The Society of Thoracic Surgeons–European Association for Cardio-Thoracic Surgery score, procedure group, aspiration, and reflux. Speech-language pathology was the most frequently utilised consulting service for patients discharged with feeding tubes (90.28%) while other services were not frequently consulted. The median length of stay was increased from 4 to 10 days for patients who required an enteral feeding tube at discharge.
Multidisciplinary management protocol and interventions should be developed and standardised to improve feeding outcomes following congenital heart surgery.
Clinical trials are a fundamental tool in evaluating the safety and efficacy of new drugs, medical devices, and health system interventions. Clinical trial visits generally involve eligibility assessment, enrollment, intervention administration, data collection, and follow-up, with many of these steps performed during face-to-face visits between participants and the investigative team. Social distancing, which emerged as one of the mainstay strategies for reducing the spread of SARS-CoV-2, has presented a challenge to the traditional model of clinical trial conduct, causing many research teams to halt all in-person contacts except for life-saving research. Nonetheless, clinical research has continued during the pandemic because study teams adapted quickly, turning to virtual visits and other similar methods to complete critical research activities. The purpose of this special communication is to document this rapid transition to virtual methodologies at Clinical and Translational Science Awards hubs and highlight important considerations for future development. Looking beyond the pandemic, we envision that a hybrid approach, which implements remote activities when feasible but also maintains in-person activities as necessary, will be adopted more widely for clinical trials. There will always be a need for in-person aspects of clinical research, but future study designs will need to incorporate remote capabilities.
Water-filled boreholes in cold ice refreeze in hours to days, and prior attempts to keep them open with antifreeze resulted in a plug of slush effectively freezing the hole even faster. Thus, antifreeze as a method to stabilize hot-water boreholes has largely been abandoned. In the hot-point drilling case, no external water is added to the hole during drilling, so earlier antifreeze injection is possible while the drill continues melting downward. Here, we use a cylindrical Stefan model to explore slush formation within the parameter space representative of hot-point drilling. We find that earlier injection timing creates an opportunity to avoid slush entirely by injecting sufficient antifreeze to dissolve the hole past the drilled radius. As in the case of hot-water drilling, the alternative is to force mixing in the hole after antifreeze injection to ensure that ice refreezes onto the borehole wall instead of within the solution as slush.
With human influences driving populations of apex predators into decline, more information is required on how factors affect species at national and global scales. However, camera-trap studies are seldom executed at a broad spatial scale. We demonstrate how uniting fine-scale studies and utilizing camera-trap data of non-target species is an effective approach for broadscale assessments through a case study of the brown hyaena Parahyaena brunnea. We collated camera-trap data from 25 protected and unprotected sites across South Africa into the largest detection/non-detection dataset collected on the brown hyaena, and investigated the influence of biological and anthropogenic factors on brown hyaena occupancy. Spatial autocorrelation had a significant effect on the data, and was corrected using a Bayesian Gibbs sampler. We show that brown hyaena occupancy is driven by specific co-occurring apex predator species and human disturbance. The relative abundance of spotted hyaenas Crocuta crocuta and people on foot had a negative effect on brown hyaena occupancy, whereas the relative abundance of leopards Panthera pardus and vehicles had a positive influence. We estimated that brown hyaenas occur across 66% of the surveyed camera-trap station sites. Occupancy varied geographically, with lower estimates in eastern and southern South Africa. Our findings suggest that brown hyaena conservation is dependent upon a multi-species approach focussed on implementing conservation policies that better facilitate coexistence between people and hyaenas. We also validate the conservation value of pooling fine-scale datasets and utilizing bycatch data to examine species trends at broad spatial scales.
The Eating Assessment in Toddlers FFQ (EAT FFQ) has been shown to have good reliability and comparative validity for ranking nutrient intakes in young children. With the addition of food items (n 4), we aimed to re-assess the validity of the EAT FFQ and estimate calibration factors in a sub-sample of children (n 97) participating in the Growing Up Milk – Lite (GUMLi) randomised control trial (2015–2017). Participants completed the ninety-nine-item GUMLi EAT FFQ and record-assisted 24-h recalls (24HR) on two occasions. Energy and nutrient intakes were assessed at months 9 and 12 post-randomisation and calibration factors calculated to determine predicted estimates from the GUMLi EAT FFQ. Validity was assessed using Pearson correlation coefficients, weighted kappa (κ) and exact quartile categorisation. Calibration was calculated using linear regression models on 24HR, adjusted for sex and treatment group. Nutrient intakes were significantly correlated between the GUMLi EAT FFQ and 24HR at both time points. Energy-adjusted, de-attenuated Pearson correlations ranged from 0·3 (fibre) to 0·8 (Fe) at 9 months and from 0·3 (Ca) to 0·7 (Fe) at 12 months. Weighted κ for the quartiles ranged from 0·2 (Zn) to 0·6 (Fe) at 9 months and from 0·1 (total fat) to 0·5 (Fe) at 12 months. Exact agreement ranged from 30 to 74 %. Calibration factors predicted up to 56 % of the variation in the 24HR at 9 months and 44 % at 12 months. The GUMLi EAT FFQ remained a useful tool for ranking nutrient intakes with similar estimated validity compared with other FFQ used in children under 2 years.
There has been scant exploration of the social and emotional wellbeing (SEWB) of young Indigenous populations that identify as LGBTQA+ (Lesbian, Gay, Bisexual, Transgender, Queer/Questioning, Asexual +). Given the vulnerability of this cohort living in Western settler colonial societies, wider investigation is called for to respond to their needs, experiences and aspirations. This paper summarizes existing research on the topic highlighting the lack of scholarship on the intersection of youth, Indigeneity, LGBTQA+ and SEWB. The paper takes a holistic approach to provide a global perspective that draws on an emerging body of literature and research driven by Indigenous scholars in settler colonial societies. The paper points to the importance of understanding converging colonial influences and ongoing contemporary elements, such as racism and marginalization that impact on young Indigenous LGBTQA+ wellbeing.
Emergency Medical Services (EMS) systems have developed protocols for prehospital activation of the cardiac catheterization laboratory for patients with suspected ST-elevation myocardial infarction (STEMI) to decrease first-medical-contact-to-balloon time (FMC2B). The rate of “false positive” prehospital activations is high. In order to decrease this rate and expedite care for patients with true STEMI, the American Heart Association (AHA; Dallas, Texas USA) developed the Mission Lifeline PreAct STEMI algorithm, which was implemented in Los Angeles County (LAC; California USA) in 2015. The hypothesis of this study was that implementation of the PreAct algorithm would increase the positive predictive value (PPV) of prehospital activation.
This is an observational pre-/post-study of the effect of the implementation of the PreAct algorithm for patients with suspected STEMI transported to one of five STEMI Receiving Centers (SRCs) within the LAC Regional System. The primary outcome was the PPV of cardiac catheterization laboratory activation for percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG). The secondary outcome was FMC2B.
A total of 1,877 patients were analyzed for the primary outcome in the pre-intervention period and 405 patients in the post-intervention period. There was an overall decrease in cardiac catheterization laboratory activations, from 67% in the pre-intervention period to 49% in the post-intervention period (95% CI for the difference, -14% to -22%). The overall rate of cardiac catheterization declined in post-intervention period as compared the pre-intervention period, from 34% to 30% (95% CI, for the difference -7.6% to 0.4%), but actually increased for subjects who had activation (48% versus 58%; 95% CI, 4.6%-15.0%). Implementation of the PreAct algorithm was associated with an increase in the PPV of activation for PCI or CABG from 37.9% to 48.6%. The overall odds ratio (OR) associated with the intervention was 1.4 (95% CI, 1.1-1.8). The effect of the intervention was to decrease variability between medical centers. There was no associated change in average FMC2B.
The implementation of the PreAct algorithm in the LAC EMS system was associated with an overall increase in the PPV of cardiac catheterization laboratory activation.
Registry-based trials have emerged as a potentially cost-saving study methodology. Early estimates of cost savings, however, conflated the benefits associated with registry utilisation and those associated with other aspects of pragmatic trial designs, which might not all be as broadly applicable. In this study, we sought to build a practical tool that investigators could use across disciplines to estimate the ranges of potential cost differences associated with implementing registry-based trials versus standard clinical trials.
We built simulation Markov models to compare unique costs associated with data acquisition, cleaning, and linkage under a registry-based trial design versus a standard clinical trial. We conducted one-way, two-way, and probabilistic sensitivity analyses, varying study characteristics over broad ranges, to determine thresholds at which investigators might optimally select each trial design.
Registry-based trials were more cost effective than standard clinical trials 98.6% of the time. Data-related cost savings ranged from $4300 to $600,000 with variation in study characteristics. Cost differences were most reactive to the number of patients in a study, the number of data elements per patient available in a registry, and the speed with which research coordinators could manually abstract data. Registry incorporation resulted in cost savings when as few as 3768 independent data elements were available and when manual data abstraction took as little as 3.4 seconds per data field.
Registries offer important resources for investigators. When available, their broad incorporation may help the scientific community reduce the costs of clinical investigation. We offer here a practical tool for investigators to assess potential costs savings.
The need for experimental traumatic brain injury (TBI) models comes from the drive to better understand TBI pathophysiology in order to improve outcome. Models are surrogates for human pathology, they can be cellular (in vitro) or whole organism (in vivo). Although no model can entirely replace the need for human studies, the use of cell cultures and animals offer unique advantages. There is uniformity of subjects, and the same injury can be repeatedly recreated. They allow for the creation of simple or complex injuries, whilst offering the ability to investigate global or focal change(s) from minutes to days following the insult, and there are no recruitment or loss of follow-up issues. The greatest advantages are possibly the ability to perform multiple and invasive sampling of tissues, measure fatal end points and trial widest range of drug doses which is precluded in clinical studies.
There is limited knowledge of how individuals reflect on their involuntary admission.
To investigate, at one year after an involuntary admission,
(i) peoples perception of the necessity of their involuntary admission
(ii) the enduring impact on the relationship with their family, consultant psychiatrist and employment prospects
(iii) readmission rates to hospital and risk factors for readmission.
People that were admitted involuntarily over a 15 month period were re-interviewed at one year following discharge.
Sixty eight people were re-interviewed at one year and this resulted in a follow-up rate of 84%. Prior to discharge, 72% of people reported that their involuntary admission had been necessary however this reduced to 60% after one year. Over one third of people changed their views and the majority of these patients reflected negatively towards their involuntary admission.
One quarter of people continued to experience a negative impact on the relationship with a family member and their consultant psychiatrist one year after an involuntary admission, while 13% reported a positive impact. A similar proportion perceived that it had negative consequences in their employment.
Within one year, 43% of all patients involuntarily admitted in the study period were readmitted to hospital and half of these admissions were involuntary. Involuntary readmission was associated with a sealing over recovery style.
Peoples’ perception of the necessity of their involuntary admissions changes significantly over time. Involuntary admissions can have a lasting negative impact on the relationship with family members and treating consultant psychiatrist.
Despite the scientific evidence, most families of people with schizophrenia in Europe never receive a carer education programme. We evaluated whether a carer education course delivered by telepsychiatry was as effective as a carer education course delivered in situ.
We delivered the carer education course for schizophrenia simultaneously to a carers group in rural north west Ireland (remote) via three ISDN lines and live to a carers group in a city (host). We compared knowledge gains using the Knowledge Questionnaire before and after each course.
Fifty-six carers of people with schizophrenia participated in the trial. At baseline, participants at the remote and host centers did not differ in terms of knowledge about schizophrenia. After the course, carers at both centers improved significantly and the knowledge gains between groups were equivalent at 6 weeks.
Telepsychiatry can deliver effective carer education programmes about schizophrenia and may provide one solution to bridging the chasm between scientific evidence and clinical reality.
We sought to establish if a brief psychoeducational intervention for relatives is effective in improving relatives’ knowledge about schizophrenia and reducing rehospitalization. We evaluated 101 relatives of 55 patients with schizophrenia before and after an 8-week psychoeducational group using a self-report method. We also conducted a matched case-control study of the effects on rehospitalisation for 28 of these patients. We calculated the number of hospital days for each index case and control in the 1 and 2 years before and after the intervention.
Relatives made significant gains in their knowledge about schizophrenia, particularly about medication. Patients whose relatives attended the group had significantly fewer days in hospital and days per admission compared to controls in the year after the programme but the effect waned in the second year after the intervention. Controls were almost four times more likely to be readmitted at 2 years than cases. Median time to readmission was significantly longer in cases compared to controls. We conclude that a psychoeducational group, which is valued by carers, is effective in increasing their knowledge about schizophrenia as well as reducing and forestalling the rehospitalization of their affected relatives. Such programmes deliver what carers frequently request in a cost-effective manner.
There is evidence that psycho-education courses for caregivers of individuals with schizophrenia improve the short-term outcome of the condition. However, most of the outcome studies are limited to two-year follow-up.
Materials and methods
This study is a five-year retrospective case-control follow-up of an original cohort of 63 patients and their 101 caregivers who completed a six-week Caregiver Psycho-education Programme (CPP) for schizophrenia and psychosis between 2002 and 2005, and 60 controls, matched for age, gender and severity of their psychotic illness.
Patients whose caregivers learned more from the six-week psycho-education course had a significantly longer time to relapse (P = 0.04) and a significantly shorter length of stay during their first relapse (P < 0.05). Patients whose caregivers attended the six-week psycho-education course (regardless of how much the caregivers learned) had a significantly better outcome than controls. This included a significantly smaller number of relapses (P < 0.01), longer time to relapse (P < 0.01), shorter length of stay during their first relapse (P < 0.01) and smaller number of bed days over five years (P < 0.01). The odds ratio of controls relapsing, although insignificant at one year, was 4.13 (1.85–9.21) at five years. Outcome was not affected by either the numbers of caregivers attending for each patient, or caregiver gender.
Discussion and conclusions
This study, which is among the first to examine outcome over five years, supports the efficacy of psycho-education for caregivers in improving outcome for patients. Caregivers should be encouraged to take up psycho-education where it is available.
In a RCT of family psychoeducation, 47 carers of 34 patients were allocated to one of three groups; Multifamily Group Psychoeducation, Solution Focussed Group Therapy or Treatment as Usual. Carers in both the MFGP intervention and the SFGP arm demonstrated greater knowledge and reduction in burden than those in the TAU arm.
Impaired insight is commonly seen in psychosis and some studies have proposed that is a biologically based deficit. Support for this view comes from the excess of neurological soft signs (NSS) observed in patients with psychoses and their neural correlates which demonstrate a degree of overlap with the regions of interest implicated in neuroimaging studies of insight. The aim was to examine the relationship between NSS and insight in a sample of 241 first-episode psychosis patients.
Total scores and subscale scores from three insight measures and two NSS scales were correlated in addition to factors representing overall insight and NSS which we created using principal component analysis.
There were only four significant associations when we controlled for symptoms. “Softer” Condensed Neurological Evaluation (CNE) signs were associated with our overall insight factor (r = 0.19, P = 0.02), with total Birchwood (r = −0.24, P<0.01), and the Birchwood subscales; recognition of mental illness (r = −0.24, P<0.01) and need for treatment (r = −0.18, P = 0.02). Total Neurological Evaluation Scale (NES) and recognition of the achieved effects of medication were also weakly correlated (r = 0.14, P = 0.04).
This study does not support a direct link between neurological dysfunction and insight in psychosis. Our understanding of insight as a concept remains in its infancy.
Neuregulin1 (Nrg1) is a candidate gene linked to schizophrenia. Cleavage of Nrg1 full-length (Nrg1-FL) precursor protein by BACE1 mediates activation of erbB receptors and triggers a cascade of downstream signalling events that lead to activation of GABA, NMDA, and nicotinic receptors. Studies with BACE1 knock out mouse models have demonstrated impaired Nrg1-/ErbB signalling leads to SZ-like phenotypes that can be rescued by antipsychotics.
We analysed frontal cortex brain tissue of schizophrenia (SZ) and healthy control (HC) subjects for expression of BACE1, Nrg1-FL and Nrg1 cleaved fragment.
To explore the possible mis-cleavage of Nrg1 by BACE1 in SZ as this may disrupt some neuronal circuits in the brain and trigger schizophrenia.
Samples from Brodmann area 6 region (40 SZ and 20 HC) were homogenized with TRIzol and proteins were analysed by western blotting. Also samples were analysed for RNA integrity and 18 SZ and 20 HC with high RIN were selected for qRT-PCR study.
About 50% decrease in Nrg1 C-terminal fragment (CTF) was observed in the SZ group compared to the HC group (p < 0.001). A strong correlation between Nrg-FL and BACE1 was observed (r = 0.82, P < 0.001). Results of qRT-PCR showed a significant increase in the expression of BACE1-432 splice variant in SZ compared to HC (P = 0.005). A strong inverse correlation was found between BACE1 activity and 432/501 BACE1 splice variants expression.
Our results suggest that altered expression of BACE1 and decreased cleavage of Nrg1 are associated with SZ.
Purpose: Although school-age children learn most new word meanings from surrounding context, the joint roles of language ability and executive function (EF) in the word learning process remain unclear. This study examined children's acquisition of word meanings from context in relation to oral language ability and three EF skills (working memory, inhibitory control, and cognitive flexibility). Method: Typically developing school-age children completed measures of language and EF, then read and listened to short stories containing unfamiliar target words. A multiple-choice pretest–posttest measure assessed children's target word knowledge gains. Results: Regression analyses showed that language and cognitive flexibility were both related to word knowledge gains; each skill assumed greater importance among children with relative weakness in the other skill. Conclusion: Language ability and cognitive flexibility may each play a direct role in contextual word learning among school-age children, with children naturally relying on one skill if the other is weaker.