Alfvénic velocity spikes and rotational flows in the near-Sun solar wind.

The prediction of a supersonic solar wind1 was first confirmed by spacecraft near Earth2,3 and later by spacecraft at heliocentric distances as small as 62 solar radii4. These missions showed that plasma accelerates as it emerges from the corona, aided by unidentified processes that transport energy outwards from the Sun before depositing it in the wind. Alfvénic fluctuations are a promising candidate for such a process because they are seen in the corona and solar wind and contain considerable energy5-7. Magnetic tension forces the corona to co-rotate with the Sun, but any residual rotation far from the Sun reported until now has been much smaller than the amplitude of waves and deflections from interacting wind streams8. Here we report observations of solar-wind plasma at heliocentric distances of about 35 solar radii9-11, well within the distance at which stream interactions become important. We find that Alfvén waves organize into structured velocity spikes with duration of up to minutes, which are associated with propagating S-like bends in the magnetic-field lines. We detect an increasing rotational component to the flow velocity of the solar wind around the Sun, peaking at 35 to 50 kilometres per second-considerably above the amplitude of the waves. These flows exceed classical velocity predictions of a few kilometres per second, challenging models of circulation in the corona and calling into question our understanding of how stars lose angular momentum and spin down as they age12-14.

Insomnia, psychiatric disorders and suicidal ideation in a National Representative Sample of active Canadian Forces members.

BACKGROUND: Past research on the association between insomnia and suicidal ideation (SI) has produced mixed findings. The current study explored the relationship between insomnia, SI, and past-year mental health status among a large Canadian Forces (CF) sample. METHOD: Data was obtained from the 2013 Canadian Forces Mental Health Survey (CFMHS), and included a large representative sample of Canadian Regular Forces personnel (N = 6700). A series of univariate logistic regressions were conducted to test individual associations between past-year mental health status, insomnia, and potential confounds and SI. Mental health status included three groups: 0, 1, or two or more probable diagnoses of posttraumatic stress disorder (PTSD), major depressive disorder (MDD), generalized anxiety disorder (GAD), panic disorder (PD) and alcohol abuse/dependence. Stepwise multivariate logistic regression was used to assess the relationship between insomnia and SI with mental health status as a moderator. RESULTS: 40.8% of respondents reported experiencing insomnia. Both insomnia and number of mental health conditions incrementally increased the risk of SI. However, past-year mental health status was a significant moderator of this relationship, such that for CF personnel with either no (AOR = 1.61, 1.37-1.89) or only one past-year mental health condition (AOR = 1.39, 1.12-1.73), an incremental increase in insomnia was associated with an increased likelihood of SI. However, in personnel with two or more past-year mental health disorders, insomnia was no longer significantly associated with SI (AOR = 1.04, 0.81-1.33). CONCLUSIONS: Insomnia significantly increased the odds of SI, but only among individuals with no or one mental health condition. Findings highlight the importance of assessing insomnia among CF members in order to further suicide prevention efforts.

Effect of extended morning fasting upon ad libitum lunch intake and associated metabolic and hormonal responses in obese adults.

BACKGROUND/OBJECTIVES: Breakfast omission is positively associated with obesity and increased risk of disease. However, little is known about the acute effects of extended morning fasting upon subsequent energy intake and associated metabolic/regulatory factors in obese adults. SUBJECTS/METHODS: In a randomised cross-over design, 24 obese men (n=8) and women (n=16) extended their overnight fast by omitting breakfast consumption or ingesting a typical carbohydrate-rich breakfast of 2183±393 kJ (521±94 kcal), before an ad libitum pasta lunch 3 h later. Blood samples were obtained throughout the day until 3 h post lunch and analysed for hormones implicated in appetite regulation, along with metabolic outcomes and subjective appetite measures. RESULTS: Lunch intake was unaffected by extended morning fasting (difference=218 kJ, 95% confidence interval -54 kJ, 490 kJ; P=0.1) resulting in lower total intake in the fasting trial (difference=-1964 kJ, 95% confidence interval -1645 kJ, -2281 kJ; P<0.01). Systemic concentrations of peptide tyrosine-tyrosine and leptin were lower during the afternoon following morning fasting (P⩽0.06). Plasma-acylated ghrelin concentrations were also lower following the ad libitum lunch in the fasting trial (P<0.05) but this effect was not apparent for total ghrelin (P⩾0.1). Serum insulin concentrations were greater throughout the afternoon in the fasting trial (P=0.05), with plasma glucose also greater 1 h after lunch (P<0.01). Extended morning fasting did not result in greater appetite ratings after lunch, with some tendency for lower appetite 3 h post lunch (P=0.09). CONCLUSIONS: We demonstrate for the first time that, in obese adults, extended morning fasting does not cause compensatory intake during an ad libitum lunch nor does it increase appetite during the afternoon. Morning fasting reduced satiety hormone responses to a subsequent lunch meal but counterintuitively also reduced concentrations of the appetite-stimulating hormone-acylated ghrelin during the afternoon relative to lunch consumed after breakfast.

A strong, highly-tilted interstellar magnetic field near the Solar System.

Magnetic fields play an important (sometimes dominant) role in the evolution of gas clouds in the Galaxy, but the strength and orientation of the field in the interstellar medium near the heliosphere has been poorly constrained. Previous estimates of the field strength range from 1.8-2.5 microG and the field was thought to be parallel to the Galactic plane or inclined by 38-60 degrees (ref. 2) or 60-90 degrees (ref. 3) to this plane. These estimates relied either on indirect observational inferences or modelling in which the interstellar neutral hydrogen was not taken into account. Here we report measurements of the deflection of the solar wind plasma flows in the heliosheath to determine the magnetic field strength and orientation in the interstellar medium. We find that the field strength in the local interstellar medium is 3.7-5.5 microG. The field is tilted approximately 20-30 degrees from the interstellar medium flow direction (resulting from the peculiar motion of the Sun in the Galaxy) and is at an angle of about 30 degrees from the Galactic plane. We conclude that the interstellar medium field is turbulent or has a distortion in the solar vicinity.

Magnetic fields at the solar wind termination shock.

A transition between the supersonic solar wind and the subsonic heliosheath was observed by Voyager 1, but the expected termination shock was not seen owing to a gap in the telemetry. Here we report observations of the magnetic field structure and dynamics of the termination shock, made by Voyager 2 on 31 August-1 September 2007 at a distance of 83.7 au from the Sun (1 au is the Earth-Sun distance). A single crossing of the shock was expected, with a boundary that was stable on a timescale of several days. But the data reveal a complex, rippled, quasi-perpendicular supercritical magnetohydrodynamic shock of moderate strength undergoing reformation on a scale of a few hours. The observed structure suggests the importance of ionized interstellar atoms ('pickup protons') at the shock.

Telehealth experiences in Canadian veterans: associations, strengths and barriers to care during the COVID-19 pandemic.

INTRODUCTION: Identifying barriers to care in veteran populations is critical, as veterans face increased social isolation, relationship strains and financial insecurities. For Canadian veterans experiencing barriers to accessing healthcare, telehealth may be a promising alternative with comparable effectiveness to in-person services; however, the potential benefits and limitations of telehealth require further examination to determine its long-term utility, and to inform health policy and planning. The goal of the present research was to identify predictors and barriers to telehealth usage in Canadian veterans in the context of the COVID-19 pandemic. METHODS: Data were drawn from baseline data of a longitudinal survey examining the psychological functioning of Canadian veterans during the COVID-19 pandemic. Participants were 1144 Canadian veterans aged 18-93 years (Mage=56.24, SD=12.92; 77.4% men). We assessed reported telehealth use (ie, for mental healthcare, physical healthcare), healthcare access (ie, difficulty accessing care, avoidance of care) and mental health and stress since the beginning of the COVID-19 pandemic, sociodemographic variables and open-ended responses about telehealth experiences. RESULTS: Findings suggest that sociodemographic factors and previous telehealth use were significantly associated with telehealth use during the COVID-19 pandemic. Qualitative evidence highlighted both the benefits (eg, reducing barriers of access) and drawbacks (eg, not all services can be delivered) of telehealth services. CONCLUSIONS: This paper provided a deeper understanding of Canadian veterans' experiences with accessing telehealth care during the COVID-19 pandemic. While for some, the use of telehealth mitigated perceived barriers (eg, safety concerns of leaving home), others felt that not all health services could be appropriately carried out through telehealth. Altogether, findings support the use of telehealth services in increasing care accessibility for Canadian veterans. Continued use of quality telehealth services may be a valuable form of care that extends the reach of healthcare professionals.

Multivessel coronary artery spasm.

Coronary spasm is increasingly recognised as an important aetiological mechanism causing myocardial ischaemia. Occasionally cases present with evidence of ST segment elevation myocardial infarction, usually secondary to spasm confined to a solitary coronary artery. We present the rare and life-threatening case of severe coronary spasm afflicting all three major epicardial arteries simultaneously. It describes the difficult emergency scenario and ongoing management dilemmas encountered by physicians confronted with multivessel coronary spasm. Moreover we discuss the malignant prognosis associated with this ailment and describe the potential insights provided by cardiac magnetic resonance imaging that might identify those at greatest risk after the index event.

Observations of the Outer Heliosphere, Heliosheath, and Interstellar Medium.

The Voyager spacecraft have left the heliosphere and entered the interstellar medium, making the first observations of the termination shock, heliosheath, and heliopause. New Horizons is observing the solar wind in the outer heliosphere and making the first direct observations of solar wind pickup ions. This paper reviews the observations of the solar wind plasma and magnetic fields throughout the heliosphere and in the interstellar medium.

Shocks in the Very Local Interstellar Medium.

Large-scale disturbances generated by the Sun's dynamics first propagate through the heliosphere, influence the heliosphere's outer boundaries, and then traverse and modify the very local interstellar medium (VLISM). The existence of shocks in the VLISM was initially suggested by Voyager observations of the 2-3 kHz radio emissions in the heliosphere. A couple of decades later, both Voyagers crossed the definitive edge of our heliosphere and became the first ever spacecraft to sample interstellar space. Since Voyager 1's entrance into the VLISM, it sampled electron plasma oscillation events that indirectly measure the medium's density, increasing as it moves further away from the heliopause. Some of the observed electron oscillation events in the VLISM were associated with the local heliospheric shock waves. The observed VLISM shocks were very different than heliospheric shocks. They were very weak and broad, and the usual dissipation via wave-particle interactions could not explain their structure. Estimates of the dissipation associated with the collisionality show that collisions can determine the VLISM shock structure. According to theory and models, the existence of a bow shock or wave in front of our heliosphere is still an open question as there are no direct observations yet. This paper reviews the outstanding observations recently made by the Voyager 1 and 2 spacecraft, and our current understanding of the properties of shocks/waves in the VLISM. We present some of the most exciting open questions related to the VLISM and shock waves that should be addressed in the future.

The Early History of Heliospheric Science and the Spacecraft That Made It Possible.

Our understanding of the interaction of the large-scale heliosphere with the local interstellar medium (LISM) has undergone a profound change since the very earliest analyses of the problem. In part, the revisions have been a consequence of ever-improving and widening observational results, especially those that identified the entrance of interstellar material and gas into the heliosphere. Accompanying these observations was the identification of the basic underlying physics of how neutral interstellar gas and interstellar charged particles of different energies, up to and including interstellar dust grains, interacted with the temporal flows and electromagnetic fields of the heliosphere. The incorporation of these various basic effects into global models of the interaction, whether focused on neutral interstellar gas and pickup ions, energetic particles such as anomalous and galactic cosmic rays, or magnetic fields and large-scale flows, has profoundly changed our view of how the heliosphere and LISM interact. This article presents a brief history of the conceptual and observation evolution of our understanding of the interaction of the heliosphere with the local interstellar medium, up until approximately 1996.

Addressing moral injury in the military.

Moral injury is a relatively new, but increasingly studied, construct in the field of mental health, particularly in relation to current and ex-serving military personnel. Moral injury refers to the enduring psychosocial, spiritual or ethical harms that can result from exposure to high-stakes events that strongly clash with one's moral beliefs. There is a pressing need for further research to advance understanding of the nature of moral injury; its relationship to mental disorders such as posttraumatic stress disorder and depression; triggering events and underpinning mechanisms; and prevalence, prevention and treatment. In the meantime, military leaders have an immediate need for guidance on how moral injury should be addressed and, where possible, prevented. Such guidance should be theoretically sound, evidence-informed and ethically responsible. Further, the implementation of any practice change based on the guidance should contribute to the advancement of science through robust evaluation. This paper draws together current research on moral injury, best-practice approaches in the adjacent field of psychological resilience, and principles of effective implementation and evaluation. This research is combined with the military and veteran mental health expertise of the authors to provide guidance on the design, implementation and evaluation of moral injury interventions in the military. The paper discusses relevant training in military ethical practice, as well as the key roles leaders have in creating cohesive teams and having frank discussions about the moral and ethical challenges that military personnel face.

Plasma observations near uranus: initial results from voyager 2.

Extensive measurements of low-energy positive ions and electrons in the vicinity of Uranus have revealed a fully developed magnetosphere. The magnetospheric plasma has a warm component with a temperature of 4 to 50 electron volts and a peak density of roughly 2 protons per cubic centimeter, and a hot component, with a temperature of a few kiloelectron volts and a peak density of roughly 0.1 proton per cubic centimeter. The warm component is observed both inside and outside of L = 5, whereas the hot component is excluded from the region inside of that L shell. Possible sources of the plasma in the magnetosphere are the extended hydrogen corona, the solar wind, and the ionosphere. The Uranian moons do not appear to be a significant plasma source. The boundary of the hot plasma component at L = 5 may be associated either with Miranda or with the inner limit of a deeply penetrating, solar wind-driven magnetospheric convection system. The Voyager 2 spacecraft repeatedly encountered the plasma sheet in the magnetotail at locations that are consistent with a geometric model for the plasma sheet similar to that at Earth.

Plasma observations near neptune: initial results from voyager 2.

The plasma science experiment on Voyager 2 made observations of the plasma environment in Neptune's magnetosphere and in the surrounding solar wind. Because of the large tilt of the magnetic dipole and fortuitous timing, Voyager entered Neptune's magnetosphere through the cusp region, the first cusp observations at an outer planet. Thus the transition from the magnetosheath to the magnetosphere observed by Voyager 2 was not sharp but rather appeared as a gradual decrease in plasma density and temperature. The maximum plasma density observed in the magnetosphere is inferred to be 1.4 per cubic centimeter (the exact value depends on the composition), the smallest observed by Voyager in any magnetosphere. The plasma has at least two components; light ions (mass, 1 to 5) and heavy ions (mass, 10 to 40), but more precise species identification is not yet available. Most of the plasma is concentrated in a plasma sheet or plasma torus and near closest approach to the planet. A likely source of the heavy ions is Triton's atmosphere or ionosphere, whereas the light ions probably escape from Neptune. The large tilt of Neptune's magnetic dipole produces a dynamic magnetosphere that changes configuration every 16 hours as the planet rotates.

The dancing heart.

A woman with palliative breast cancer presents with dyspnoea and is noted to have an unusual electrocardiogram, with an alternating electrical axis observed. Subsequent echocardiogram demonstrates the classical findings of a large pericardial effusion causing 'electrical alternans' aptly illustrating why this rare phenomenon occurs.

Management of necrotizing tracheostomy infections.

Management of three patients with necrotizing tracheostomy infections resulting in tracheal dissolution was reviewed with respect to presentation, cause, and management. Loss of tracheal substance led to difficulty in ventilation because of a large air leak. The stomal area cavitated in two patients, denuding the right common carotid artery in one. Purulent peristomal drainage was present in all three patients. Common factors of possible etiologic significance included necrotizing polymicrobial gram-negative tracheobronchial infections caused by Pseudomonas, Enterobacter, and Klebsiella species. Also of possible importance were suture fixation of the appliance, history of neurologic injury, and closure of the incision. Immediate therapy consisted of oral intubation for ventilatory purposes and a regimen of hourly application of 1% neomycin dressings. Seven to 21 days were necessary to allow formation of sufficient granulation tissue to support replacement of the tracheostomy appliance for continued mechanical ventilation. Once spontaneous ventilation was possible, a Montgomery T-tube was inserted for long-term tracheal stenting prior to reconstruction. The two patients treated by tracheal stenting are long-term survivors. Avoidance of suture fixation of the appliance, aggressive treatment of bronchopulmonary infection, and adequate stomal toilet may help to avoid this devastating complication.

Closed aortic valvotomy and simultaneous correction of associated anomalies in infants.

A small infant with severe congenital aortic stenosis presents a difficult therapeutic problem. Both operative and nonoperative treatment are hazardous--especially when other cardiovascular anomalies are present. This report describes a simple, effective technique for dilating the stenotic aortic valve and simultaneously repairing certain associated defects. The procedure has been used successfully in 3 infants with a postoperative follow-up of 6 months to 4 years. There were no deaths, and the functional results have been excellent. This technique is presented as an alternative to the more hazardous approach to open valvotomy and/or stage correction of associated anomalies.

Prophylactic antibiotics in the treatment of penetrating chest wounds. A prospective double-blind study.

Considerable controversy exists as to whether or not antibiotics should be administered "prophylactically" to patients with penetrating chest trauma. No prospective study of this problem has been reported. Therefore, 75 patients with isolated, penetrating chest injury were randomized prospectively in a double-blind study. Group A patients (38 patients) were given 300 mg. of clindamycin phosphate every 6 hours, beginning with admission and lasting until 1 day following chest tube removal or for 5 days, whichever was shorter. Group B patients (37 patients) were given a placebo on the same schedule. The patients' hospital course, fever, white blood count, culture data, and roentgenograms were recorded serially. Clindamycin-treated patients had a significantly lower incidence of radiographic pneumonia, less fever, and a lower incidence of positive pleural and wound cultures. They acquired empyema less frequently, required fewer operations, and had a shorter period of hospitalization. Antibiotics may be useful, therefore, as adjunctive therapy in the management of penetrating chest trauma.

Fatal air embolism following gunshot wound of the lung.

Air embolism following penetrating lung trauma has been reported infrequently and its existence is questioned. A death resulting from air embolism following a high-velocity gunshot wound is presented. Appropriate treatment and preventive measures are discussed.

Peritoneal mesothelioma in a male pseudohermaphrodite with asymmetrical gonadal differentiation.

A diffuse peritoneal mesothelioma occurring in a patient with male pseudohermaphroditism and asymmetrical gonadal differentiation (mixed gonadal dysgenesis) is described. Malignancies of mesodermal origin, usually derivatives of the urogenital ridge, appear to occur with increased frequency in male pseudohermaphrodites. This appears to be the first reported instance of a mesothelioma in a male pseudohermaphrodite with mixed gonadal dysgenesis. The clinical and pathologic features of this tumor, including the electron microscopic findings, are presented.

Arterial injuries with lower extremity fracture.

Review of the records of 41 patients with lower extremity fractures associated with major arterial injuries disclosed that femoral artery injuries were consistently repaired with excellent results and no amputations. Diagnostic delay contributed to an 18% amputation rate following popliteal artery disruption. When arteries distal to the popliteal trifurcation were completely disrupted, a 25% rate of long-term good results was obtained.