Predictors of social distancing compliance in an Australian sample.

Pandemics are associated with high rates of morbidity and mortality, and the coronavirus disease (COVID-19) pandemic has been the most fatal coronavirus outbreak of the 21st century. To reduce person-to-person transmission, interventions such as social distancing have been recommended; however, it is anticipated that 80% compliance is required to control the outbreak. A questionnaire was used to assess the factors related to compliance with social distancing restrictions using a modified version of the Theory of Planned Behavior (TPB) that included participants' understanding of restrictions. The questionnaire included 18 vignettes (violating, non-violating and ambiguous) to assess participants' knowledge of the social distancing restrictions and intentions to violate them. Participants were also presented the social distancing restrictions relevant at the time of completion and they were asked to consider the restrictions when anticipating their behavior in the vignettes. In line with the predictions of the TPB, intentions to adhere to restrictions and perceived behavioral control predicted participants' self-reported behaviors. Further, attitudes (ATT) toward social distancing restrictions and knowledge of the restrictions predicted intentions to adhere to them. Public health messaging should aim to increase the understanding of the restrictions, e.g. through the use of example scenarios of permitted and prohibited behaviors. This would be particularly beneficial when changes are implemented to promote the understanding of the restrictions and positive ATT toward them.

Regime change in the recorder: Using Navier-Stokes modeling to design a better instrument.

Blowing a recorder at a low to moderate blowing speed with the toneholes all closed yields the lowest note in the range of the instrument. As the blowing speed is increased, the tone abruptly changes to the tone an octave higher. This "jump" in the frequency of the dominant spectral component of the tone is referred to as "regime change." Interestingly, in conversations with recorder players, several have mentioned that regime change seems to occur at a significantly lower blowing speed for bass recorders than for instruments that sound an octave or more higher. In this paper we study regime change in the recorder and use Navier-Stokes modeling to confirm and study differences in the behavior of different instruments in the recorder family. We show, using modeling, how the regime change threshold in a model of the bass recorder can be increased by changing the geometry in the vicinity of the labium. These results are then confirmed through experimental studies of real recorders with designs inspired by the modeling results. The insights gained from these results suggest new recorder designs that may produce instruments that in some respects are more playable than current instruments.

Navier-Stokes-based model of the clarinet.

A model of a single reed instrument is studied in which the reed is described as an Euler-Bernoulli beam, and the air flow through the instrument is calculated using the Navier-Stokes equations. The hypothetical instrument resembles a clarinet, but is smaller than a real clarinet to keep the numerical modeling feasible on available supercomputers. This article explores the conditions under which the frequency of the reed oscillations and the emitted sound are determined by the resonant frequency of the bore of the instrument. The effect of the contact between the reed and the player's lips is also studied, and quantitative results for the air density and pressure in the mouthpiece and throughout the instrument bore are also presented.

Enhanced Recovery After Surgery (ERAS) for gastrointestinal surgery, part 2: consensus statement for anaesthesia practice.

BACKGROUND: The present interdisciplinary consensus review proposes clinical considerations and recommendations for anaesthetic practice in patients undergoing gastrointestinal surgery with an Enhanced Recovery after Surgery (ERAS) programme. METHODS: Studies were selected with particular attention being paid to meta-analyses, randomized controlled trials and large prospective cohort studies. For each item of the perioperative treatment pathway, available English-language literature was examined and reviewed. The group reached a consensus recommendation after critical appraisal of the literature. RESULTS: This consensus statement demonstrates that anaesthesiologists control several preoperative, intraoperative and postoperative ERAS elements. Further research is needed to verify the strength of these recommendations. CONCLUSIONS: Based on the evidence available for each element of perioperative care pathways, the Enhanced Recovery After Surgery (ERAS®) Society presents a comprehensive consensus review, clinical considerations and recommendations for anaesthesia care in patients undergoing gastrointestinal surgery within an ERAS programme. This unified protocol facilitates involvement of anaesthesiologists in the implementation of the ERAS programmes and allows for comparison between centres and it eventually might facilitate the design of multi-institutional prospective and adequately powered randomized trials.

Chemiluminescent Probes for Imaging H2S in Living Animals.

Hydrogen sulphide (H2S) is an endogenous mediator of human health and disease, but precise measurement in living cells and animals remains a considerable challenge. We report the total chemical synthesis and characterization of three 1,2-dioxetane chemiluminescent reaction-based H2S probes, CHS-1, CHS-2, and CHS-3. Upon treatment with H2S at physiological pH, these probes display instantaneous light emission that is sustained for over an hour with high selectivity against other reactive sulphur, oxygen, and nitrogen species. Analysis of the phenol/phenolate equilibrium and atomic charges has provided a generally applicable predictive model to design improved chemiluminescent probes. The utility of these chemiluminescent reagents was demonstrated by applying CHS-3 to detect cellularly generated H2S using a multi-well plate reader and to image H2S in living mice using CCD camera technology.

Decompression illness in goats following simulated submarine escape: 1993-2006.

The United Kingdom Ministry of Defence commissioned work to define the relationship between the internal pressure of a distressed submarine (DISSUB), the depth from which escape is made and the risk of decompression illness (DCI). The program of work used an animal model (goat) to define these risks and this paper reports the incidence and type of DCI observed. A total of 748 pressure exposures comprising saturation only, escape only or saturation followed by escape were conducted in the submarine escape simulator between 1993 and 2006. The DCI following saturation exposures was predominantly limb pain, whereas following escape exposures the DCI predominantly involved the central nervous system and was fast in onset. There was no strong relationship between the risk of DCI and the range of escape depths investigated. The risk of DCI incurred from escape following saturation was greater than that obtained by combining the risks for the independent saturation only, and escape only, exposures. The output from this program of work has led to improved advice on the safety of submarine escape.

Submarine tower escape decompression sickness risk estimation.

Actions to enhance survival in a distressed submarine (DISSUB) scenario may be guided in part by knowledge of the likely risk of decompression sickness (DCS) should the crew attempt tower escape. A mathematical model for DCS risk estimation has been calibrated against DCS outcome data from 3,738 exposures of either men or goats to raised pressure. Body mass was used to scale DCS risk. The calibration data included more than 1,000 actual or simulated submarine escape exposures and no exposures with substantial staged decompression. Cases of pulmonary barotrauma were removed from the calibration data. The calibrated model was used to estimate the likelihood of DCS occurrence following submarine escape from the United Kingdom Royal Navy tower escape system. Where internal DISSUB pressure remains at - 0.1 MPa, escape from DISSUB depths < 200 meters is estimated to have DCS risk < 6%. Saturation at raised DISSUB pressure markedly increases risk, with > 60% DCS risk predicted for a 200-meter escape from saturation at 0.21 MPa. Using the calibrated model to predict DCS for direct ascent from saturation gives similar risk estimates to other published models.

Submarine 'safe to escape' studies in man.

The Royal Navy requires reliable advice on the safe limits of escape from a distressed submarine (DISSUB). Flooding in a DISSUB may cause a rise in ambient pressure, increasing the risk of decompression sickness (DCS) and decreasing the maximum depth from which it is safe to escape. The aim of this study was to investigate the pressure/depth limits to escape following saturation at raised ambient pressure. Exposure to saturation pressures up to 1.6 bar (a) (160 kPa) (n = 38); escapes from depths down to 120 meters of sea water (msw) (n = 254) and a combination of saturation followed by escape (n = 90) was carried out in the QinetiQ Submarine Escape Simulator, Alverstoke, United Kingdom. Doppler ultrasound monitoring was used to judge the severity of decompression stress. The trials confirmed the previously untested advice, in the Guardbook, that if a DISSUB was lying at a depth of 90 msw, then it was safe to escape when the pressure in the DISSUB was 1.5 bar (a), but also indicated that this advice may be overly conservative. This study demonstrated that the upper DISSUB saturation pressure limit to safe escape from 90 msw was 1.6 bar (a), resulting in two cases of DCS.

A simple scoring system for risk-stratifying rectal cancer patients prior to radical resection.

BACKGROUND: Various predictors of perioperative risk for patients with rectal cancer undergoing radical resection have been well described, but no simple scoring system for surgeons to estimate this risk currently exists. The objective of this study was to develop a system for more accurate preoperative evaluations of competing risks and more informed shared decision-making with patients diagnosed with rectal cancer. METHODS: The National Surgical Quality Improvement Program-Participant Use Data File for 2005-2011 was used to retrospectively identify patients undergoing radical resection for rectal cancer. A forward-stepwise multivariable logistic regression model was used to create a dynamic scoring system to preoperatively estimate a patient's risk of major complications. RESULTS: A total of 6,847 patients met study inclusion criteria. Thirteen risk factors were identified, and using these predictive variables, a scoring system was derived to stratify major complication risk after radical resection. CONCLUSIONS: The risk of a major complication after radical resection for rectal cancer is dependent on multiple preoperative variables. This study provides surgeons with a simple but effective tool for estimating major complication risk in rectal cancer patients prior to radical resection. This risk-stratification score serves as a patient-centered resource for discussing perioperative risks and assisting with the shared decision-making of operative planning.

Is follow-up CT imaging of the chest and abdomen necessary after preoperative neoadjuvant therapy in rectal cancer patients without evidence of metastatic disease at diagnosis?

AIM: Patients with rectal cancer often undergo multiple CT scans prior to surgical resection. We propose that in patients with locally advanced rectal cancer without evidence of metastatic disease at presentation, CT imaging of the chest and abdomen after preoperative neoadjuvant therapy does not change clinical information or surgical management. METHOD: An institutional review board-approved medical record review identified patients with contrast enhanced CT of the chest, abdomen and pelvis alone or in conjunction with (18)F-fluoro-2-deoxy-d-glucose/positron emission tomography imaging for staging of rectal cancer prior to and after neoadjuvant therapy. Eighty-eight patients were included in the study. Scans were reviewed for the presence of metastatic disease on initial and follow-up imaging prior to surgical resection. RESULTS: Seventy-six (86%) of 88 patients had no evidence of metastasis at presentation. None of these patients developed metastatic disease after neoadjuvant therapy. Twelve (14%) had metastases at presentation. No study patient developed metastatic disease in a new organ. CONCLUSION: Imaging after preoperative neoadjuvant therapy in rectal cancer does not change the designation of metastatic disease. Patients with locally advanced rectal adenocarcinoma without evidence of metastases may not benefit from repeat imaging of the chest and abdomen after neoadjuvant therapy.

Guidelines for perioperative care in elective rectal/pelvic surgery: Enhanced Recovery After Surgery (ERAS®) Society recommendations.

BACKGROUND: This review aims to present a consensus for optimal perioperative care in rectal/pelvic surgery, and to provide graded recommendations for items for an evidenced-based enhanced recovery protocol. METHODS: Studies were selected with particular attention paid to meta-analyses, randomized controlled trials and large prospective cohorts. For each item of the perioperative treatment pathway, available English-language literature was examined, reviewed and graded. A consensus recommendation was reached after critical appraisal of the literature by the group. RESULTS: For most of the protocol items, recommendations are based on good-quality trials or meta-analyses of good-quality trials (evidence grade: high or moderate). CONCLUSIONS: Based on the evidence available for each item of the multimodal perioperative care pathway, the Enhanced Recovery After Surgery (ERAS) Society, European Society for Clinical Nutrition and Metabolism (ESPEN) and International Association for Surgical Metabolism and Nutrition (IASMEN) present a comprehensive evidence-based consensus review of perioperative care for rectal surgery.

Successful lung retransplantation after extended use of extracorporeal membrane oxygenation as a bridge.

Redo lung transplantation remains a major clinical challenge and its indication for patients with early allograft dysfunction is difficult to determine. We report a case of potentially fatal early allograft dysfunction owing to possible acute cellular rejection after single lung transplantation in a patient who underwent redo double lung transplantation after successful use of extracorporeal membrane oxygenation as a bridge, which resulted in a successful outcome.

Effects of the AMPA receptor modulator S 18986 on measures of cognition and oxidative stress in aged rats.

RATIONALE: Development of cognitive-enhancing drugs that delay or halt mild cognitive impairment progression to Alzheimer's disease would be of great benefit. OBJECTIVES: The aim of this study was to examine the ability of (S)-2,3-dihydro-[3,4]-cyclopentano-1,2,4-benzothiadiazine-1,1-dioxide (S 18986), a positive allosteric modulator of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, to improve behavioral performance and alleviate age-related deficits in oxidative stress status in the prelimbic cortex and hippocampus. MATERIALS AND METHODS: Daily administration of S 18986 (0.1, 0.3, and 1.0 mg/kg) or vehicle was given to separate groups of male rats starting at 12 months of age. Additionally, daily vehicle administration was given to a group of rats starting at 3 months of age. Four months after initiation of drug administration, rats were trained and tested in an operant-delayed alternation task and a reinforcer devaluation task. Upon completion of testing, oxidative stress status was assessed in the prelimbic cortex and hippocampus. RESULTS: S 18986 dose-dependently altered responses in the reinforcer devaluation task such that aged rats came to resemble young rats. There were no age or drug effects in the operant-delayed alternation task. Levels of the lipid peroxidation product 4-hydroxy-nonenal (HNE) were increased, and Cu/Zn-superoxide dismutase (SOD) levels were decreased in prelimbic cortex in aged rats, changes that were reversed by S 18986. Similarly, age-related increases in hippocampal HNE levels were prevented by S 18986. CONCLUSIONS: Positive modulation of AMPA receptor activity may be a therapeutic approach to halt or slow progression of mild cognitive impairment via improvement in oxidative stress status in the hippocampus and prelimbic cortex.

Isolation of oligodendrocyte-like cells from human umbilical cord blood.

BACKGROUND: As human umbilical cord blood (UCB) is known to be a rich source of progenitor cells, the prospect of isolating a subset of these cells that could differentiate into cells of non-hematopoietic lineages suggests a therapeutic use for patients with inherited lysosomal and peroxisomal storage diseases currently treated with UCB transplantation. METHODS: Oligodendrocyte-like cells were isolated from UCB by density-gradient centrifugation and expanded using selective media. We then characterized this population of cells using standard immunohistochemical staining methods for neural cell proteins and polymerase chain reaction (PCR) to detect RNA sequences for myelin basic protein (MBP). We also developed a functional assay demonstrating myelination of neurons in vitro. RESULTS: Cells with oligodendrocyte-like morphology were reproducibly cultured ex vivo from fresh human UCB. Cells stained positively for multiple oligodendria cell markers (O1, MBP and CNPase) via immunohistochemical staining and flow cytometry. PCR confirmed the presence of MBP and CNPase mRNA. A further in vitro functional assay demonstrated the myelination of mature neuronal cells from the brain of a myelin-deficient murine model co-cultured with the oligodendrocyte-like cells. DISCUSSION: After human UCB transplant, donor-derived cells have been noted to migrate to the brain over time. Although is not known whether these cells solely deliver enzyme replacement or a subset engrafts and differentiates into mature neural cells, the clinical improvements noted in these patients suggest a potential role for targeted cellular therapy. Oligodendrocyte-like cells isolated ex vivo and expanded from human UCB could provide a potential cellular therapy for patients with demyelinating or dismyelinating diseases.

Assessing radiation-associated mutational risk to the germline: repetitive DNA sequences as mutational targets and biomarkers.

This review assesses recent data on mutational risk to the germline after radiation exposure obtained by molecular analysis of tandemly repeated DNA loci (TRDLs): minisatellites in humans and expanded simple tandem repeats in mice. Some studies, particularly those including exposure to internal emitters, indicate that TRDL mutation can be used as a marker of human radiation exposure; most human studies, however, are negative. Although mouse studies have suggested that TRDL mutation analysis may be more widely applicable in biomonitoring, there are important differences between the structure of mouse and human TRDLs. Mutational mechanisms probably differ between the two species, and so care should be taken in predicting effects in humans from mouse data. In mice and humans, TRDL mutations are largely untargeted with only limited evidence of dose dependence. Transgenerational mutation has been observed in mice but not in humans, but the mechanisms driving such mutation transmission are unknown. Some minisatellite variants are associated with human diseases and may affect gene transcription, but causal relationships have not yet been established. It is concluded that at present the TRDL mutation data do not warrant a dramatic revision of germline or cancer risk estimates for radiation.

The role of homologous recombination repair in the formation of chromosome aberrations.

The repair of DNA double strand breaks by homologous recombination can occur by at least two pathways: a Rad51-dependent pathway that is predominantly error free, and a Rad51-independent pathway (single strand annealing, SSA) that is error prone. In theory, chromosome exchanges can result from (mis)repair by either pathway. Both repair pathways will involve a search for homologous sequence, leading to co-localization of chromatin. Genes involved in homologous recombination repair (HRR) have now been successfully knocked out in mice and the role of HRR in the formation of chromosome exchanges, particularly after ionising radiation, is discussed in the light of new evidence.

The effect of breathing hyperoxic gas during simulated submarine escape on venous gas emboli and decompression illness.

Raised internal pressure in a distressed submarine rapidly increases the risk of decompression sickness (DCS) following submarine escape. The hypothesis that breathing a hyperoxic gas during escape may reduce the risk of DCS was tested using goats. Shallow air saturation and simulated submarine escape dives were carried out either singularly or in combination (saturation, escape, or saturation followed by escape) using air or 60% / 40% oxygen (O2) / nitrogen (N2) mixture as breathing gas during the escapes. Post-surfacing, animals were observed for signs of DCI and O2 toxicity. Precordial Doppler ultrasound was used to score venous gas emboli (VGE) using the Kisman Masurel (KM) scale. Following escape from 2.5 MPa, the rate at which VGE disappeared in the hyperoxic group (n = 8) was significantly faster(p < 0.05) than the air group (n = 7). One case of pulmonary barotrauma with arterial gas embolism occurred in the air group, but no cases of DCS were observed. After saturation at 0.18 MPa followed by escape from 2.5 MPa, DCS occurred in four of 15 animals in the air group and in two of 16 animals in the hyperoxic group. The rate of disappearance of VGE was significantly faster (p < 0.01) in the hyperoxic group. O2 toxicity was not discernible in any of the animals.

A community based, patient-centred, longitudinal medical curriculum.

The School of Rural Health is an initiative of the Australian Commonwealth Government, the University of New South Wales, Australia, and the Greater Murray Area Health Service. The school was established in February 2000 to facilitate the recruitment of doctors to and their retention in rural areas. The school is responsible for providing an education program for half of the three-year clinical component of the six-year undergraduate course. This article outlines the educational philosophies and methodologies employed in the development of a community-based, patient-centred, longitudinal approach to medical education. Although developed for and delivered in a rural setting, the curriculum could easily be adapted for implementation in an urban setting. The article presents a synopsis of experiences during the initial implementation of the curriculum, and it provides recommendations for future developments.