Internal tsunamigenesis and ocean mixing driven by glacier calving in Antarctica.

Ocean mixing around Antarctica exerts key influences on glacier dynamics and ice shelf retreats, sea ice, and marine productivity, thus affecting global sea level and climate. The conventional paradigm is that this is dominated by winds, tides, and buoyancy forcing. Direct observations from the Antarctic Peninsula demonstrate that glacier calving triggers internal tsunamis, the breaking of which drives vigorous mixing. Being widespread and frequent, these internal tsunamis are at least comparable to winds, and much more important than tides, in driving regional shelf mixing. They are likely relevant everywhere that marine-terminating glaciers calve, including Greenland and across the Arctic. Calving frequency may change with higher ocean temperatures, suggesting possible shifts to internal tsunamigenesis and mixing in a warming climate.

The unquantified mass loss of Northern Hemisphere marine-terminating glaciers from 2000-2020.

In the Northern Hemisphere, ~1500 glaciers, accounting for 28% of glacierized area outside the Greenland Ice Sheet, terminate in the ocean. Glacier mass loss at their ice-ocean interface, known as frontal ablation, has not yet been comprehensively quantified. Here, we estimate decadal frontal ablation from measurements of ice discharge and terminus position change from 2000 to 2020. We bias-correct and cross-validate estimates and uncertainties using independent sources. Frontal ablation of marine-terminating glaciers contributed an average of 44.47 ± 6.23 Gt a-1 of ice to the ocean from 2000 to 2010, and 51.98 ± 4.62 Gt a-1 from 2010 to 2020. Ice discharge from 2000 to 2020 was equivalent to 2.10 ± 0.22 mm of sea-level rise and comprised approximately 79% of frontal ablation, with the remainder from terminus retreat. Near-coastal areas most impacted include Austfonna, Svalbard, and central Severnaya Zemlya, the Russian Arctic, and a few Alaskan fjords.

Pivot to Telehealth: Narrative Reflections on Circle of Security Parenting Groups during COVID-19.

In response to COVID-19 hygiene and physical distancing restrictions, our service rapidly shifted to delivering Circle of Security-Parenting™ (COS-P) groups via telehealth. In this article we report the perspectives and experiences of the group facilitator and the parents who received the intervention during the COVID-19 pandemic. We use semi-structured, qualitative interviews to explore the advantages, challenges, and positive impacts of the online parenting group from the perspectives of the group leader and the five group participants. Participants' narrative reflections show that they were satisfied with the convenient and engaging online delivery of the program and would recommend it to other parents. Parents reported significant improvements in their parenting and greater awareness of their strengths and struggles. The online delivery of COS-P resulted in more efficient service delivery, greater attendance rates, and adherence to the model. The stressors on the experienced facilitator, due to the abrupt transition and multiple technical and communication challenges, may have been mitigated by supervisor and collegial support, as well as careful preparation for herself and the participants. Future research should investigate the effectiveness of online versus face-to-face delivery of the intervention, including what works for whom.

Arctic corridors and northern voices project: Methods for community-based participatory mapping for low impact shipping corridors in Arctic Canada.

Documenting Inuit and local knowledge is critical to its consideration within policy discussions around Arctic shipping; especially considering the rapid increase in ship traffic due to reductions in sea ice and climate change. We present our unique community-based research approach which incorporated youth training, participatory mapping, qualitative focus group discussions, and verification exercises to document Inuit communities' perspectives in Arctic Canada about Low Impact Shipping Corridors. These qualitative activities provided appropriate context and understanding around community-created maps, community-identified opportunities, concerns, and recommendations, and the policy relevance and feasibility of recommendations posed. Three activity phases were employed; 1) before engaging in in-community research, 2) during in-community research, and 3) after completing in-community research. Spatial and non-spatial data were analyzed using ArcGIS® and NVivo software, respectively. These methods and observations can inform future research initiatives, particularly transdisciplinary teams, including those involving southern-based (early career) researchers, working in Inuit Nunangat.•Methods presented here ensured that scientific processes and outputs were robust and rigorous and research was conducted in a respectful, reciprocal manner.•Only through the collaborative efforts of a transdisciplinary team could scientific rigour be attained and respect be afforded.•The approach can be easily applied to document community members' perspectives on local priorities.

Blue carbon gains from glacial retreat along Antarctic fjords: What should we expect?

Rising atmospheric CO2 is intensifying climate change but it is also driving global and particularly polar greening. However, most blue carbon sinks (that held by marine organisms) are shrinking, which is important as these are hotspots of genuine carbon sequestration. Polar blue carbon increases with losses of marine ice over high latitude continental shelf areas. Marine ice (sea ice, ice shelf and glacier retreat) losses generate a valuable negative feedback on climate change. Blue carbon change with sea ice and ice shelf losses has been estimated, but not how blue carbon responds to glacier retreat along fjords. We derive a testable estimate of glacier retreat driven blue carbon gains by investigating three fjords in the West Antarctic Peninsula (WAP). We started by multiplying ~40 year mean glacier retreat rates by the number of retreating WAP fjords and their time of exposure. We multiplied this area by regional zoobenthic carbon means from existing datasets to suggest that WAP fjords generate 3,130 tonnes of new zoobenthic carbon per year (t zC/year) and sequester >780 t zC/year. We tested this by capture and analysis of 204 high resolution seabed images along emerging WAP fjords. Biota within these images were identified to density per 13 functional groups. Mean stored carbon per individual was assigned from literature values to give a stored zoobenthic Carbon per area, which was multiplied up by area of fjord exposed over time, which increased the estimate to 4,536 t zC/year. The purpose of this study was to establish a testable estimate of blue carbon change caused by glacier retreat along Antarctic fjords and thus to establish its relative importance compared to polar and other carbon sinks.

Hypertensive disorders during pregnancy are associated with reduced severe intraventricular hemorrhage in very-low-birth-weight infants.

OBJECTIVE: To determine differences in severe intraventricular hemorrhage (IVH) between very-low-birth-weight (≤1500 g, VLBW) infants born to mothers with and without hypertensive disorders (HD). DESIGN/METHODS: Retrospective analysis from the Optum Neonatal Database. The primary outcome of interest was severe IVH (grade 3 or 4). Secondary outcomes included other neonatal morbidities, mortality, and length of hospitalization. Outcomes were compared between VLBW infants born to mothers with and without HD. RESULTS: A total of 5456 infants met inclusion criteria. After multivariable regression analysis, risks of severe IVH and bronchopulmonary dysplasia (BPD) were lower ([OR 0.42, 95% CI 0.33-0.89, p = 0.01] and [OR 0.75, 95% CI 0.58-0.97, p = 0.03], respectively) and median length of hospitalization was decreased in the HD group (49 versus 61 days, p < 0.001). CONCLUSIONS: VLBW infants born to mothers with HD have a decreased risk of severe IVH, BPD, and a shorter duration of hospitalization.

Maternal breast milk feeding and length of treatment in infants with neonatal abstinence syndrome.

OBJECTIVE: The objective of this study is to assess whether infants with neonatal abstinence syndrome (NAS), who receive maternal breast milk (BM), have shorter pharmacological treatment durations and lengths of stay compared with formula-fed infants. STUDY DESIGN: Retrospective data analysis from Optum Neonatal Database for infants born between 1 January 2010 and 21 November 2016, who received treatment for NAS. Clinical characteristics and outcomes were compared between infants who received any amount of BM and those exclusively formula-fed. RESULT: Infants (1738) were analyzed. Median length of pharmacological treatment was significantly lower in infants who received any BM (14 days) compared with "no BM" group (17 days, p = 0.04). Similarly, median length of hospitalization was significantly reduced in "any BM" group (19 days vs. 20 days), which remained significant after adjustment for confounders (p = 0.01). There was no difference in hospital re-admission rates. CONCLUSION: Feeding any BM to infants with NAS was associated with both decreased lengths of pharmacological treatment and hospital stay compared with exclusively formula-fed infants.

Atmospheric forcing of rapid marine-terminating glacier retreat in the Canadian Arctic Archipelago.

The Canadian Arctic Archipelago contains >300 glaciers that terminate in the ocean, but little is known about changes in their frontal positions in response to recent changes in the ocean-climate system. Here, we examine changes in glacier frontal positions since the 1950s and investigate the relative influence of oceanic temperature versus atmospheric temperature. Over 94% of glaciers retreated between 1958 and 2015, with a region-wide trend of gradual retreat before ~2000, followed by a fivefold increase in retreat rates up to 2015. Retreat patterns show no correlation with changes in subsurface ocean temperatures, in clear contrast to the dominance of ocean forcing in western Greenland and elsewhere. Rather, significant correlations with surface melt indicate that increased atmospheric temperature has been the primary driver of the acceleration in marine-terminating glacier frontal retreat in this region.

Adverse effects of small for gestational age differ by gestational week among very preterm infants.

OBJECTIVE: To characterise the excess risk for death, grade 3-4 intraventricular haemorrhage (IVH), bronchopulmonary dysplasia (BPD) and stage 3-5 retinopathy of prematurity independently associated with birth small for gestational age (SGA) among very preterm infants, stratified by completed weeks of gestation. METHODS: Retrospective cohort study using the Optum Neonatal Database. Study infants were born <32 weeks gestation without severe congenital anomalies. SGA was defined as a birth weight <10th percentile. The excess outcome risk independently associated with SGA birth among SGA babies was assessed using adjusted risk differences (aRDs). RESULTS: Of 6708 infants sampled from 717 US hospitals, 743 (11.1%) were SGA. SGA compared with non-SGA infants experienced higher unadjusted rates of each study outcome except grade 3-4 IVH among survivors. The excess risk independently associated with SGA birth varied by outcome and gestational age. The highest aRD for death (0.27; 95% CI 0.13 to 0.40) occurred among infants born at 24 weeks gestation and declined as gestational age increased. In contrast, the peak aRDs for BPD among survivors (0.32; 95% CI 0.20 to 0.44) and the composites of death or BPD (0.35; 95% CI 0.24 to 0.46) and death or major morbidity (0.35; 95% CI 0.24 to 0.45) occurred at 27 weeks gestation. The risk-adjusted probability of dying or developing one or more of the evaluated morbidities among SGA infants was similar to that of non-SGA infants born approximately 2-3 weeks less mature. CONCLUSION: The excess risk for neonatal morbidity and mortality associated with being born SGA varies by adverse outcome and gestational age.

Association between early antibiotic exposure and bronchopulmonary dysplasia or death.

OBJECTIVE: To characterize the independent association between antibiotic exposure in the first week of life and the risk of bronchopulmonary dysplasia (BPD) or death among very preterm infants without culture-confirmed sepsis. METHODS: Retrospective cohort study using the Optum Neonatal Database. Infants without culture-confirmed sepsis born less than 1500 g and less than 32 weeks gestation between 1/2010 and 11/2016 were included. The independent association between antibiotic therapy during the first week of life and BPD or death prior to 36 weeks postmenstrual age (PMA) was assessed by multivariable logistic regression. RESULTS: Of 4950 infants, 3946 (79.7%) received antibiotics during the first week of life. Rates of BPD or death (41.5% vs. 31.1%, p < 0.001) and the two individual outcomes were significantly higher among antibiotic treated infants. After adjusting for potential confounding variables, antibiotic use in the first week of life was not associated with increased risk of BPD or death (OR 0.96, 95% CI [0.76,1.21]) or BPD among survivors (OR 0.86, 95% CI [0.67,1.09]). Antibiotic use was associated with increased risk of death prior to 36 weeks PMA (OR 3.01, 95% CI [1.59,5.71]), however, secondary analyses suggested this association may be confounded by unmeasured illness severity. CONCLUSIONS: Antibiotic exposure in the first week of life among preterm infants without culture-confirmed sepsis was not independently associated with increased risk of BPD or death.

PATIENT AND PUBLIC INVOLVEMENT IN EARLY AWARENESS AND ALERT ACTIVITIES: AN EXAMPLE FROM THE UNITED KINGDOM.

OBJECTIVES: The aim of this study is to report on the experiences, benefits, and challenges of patient and public involvement and engagement (PPIE) from a publicly funded early awareness and alert (EAA) system in the United Kingdom. METHODS: Using email, telephone, a Web site portal, Twitter and focus groups, patients and the public were involved and engaged in the recognized stages of an EAA system: identification, filtration, prioritization, early assessment, and dissemination. RESULTS: Approaches for PPIE were successfully integrated into all aspects of the National Institute for Health Research Horizon Scanning Research and Intelligence Centre's EAA system. Input into identification activities was not as beneficial as involvement in prioritization and early assessment. Patients gave useful insight into the Centre's Web site and engaging patients using Twitter has enabled the Centre to disseminate outputs to a wider audience. CONCLUSIONS: EAA systems should consider involving and engaging with patients and the public in identification, prioritization, and assessment of emerging health technologies where practicable. Further research is required to examine the value and impact of PPIE in EAA activities and in the early development of health technologies.

Car Seat Tolerance Screening in the Neonatal Intensive Care Unit: Failure Rates, Risk Factors, and Adverse Outcomes.

OBJECTIVE: To characterize the epidemiology of Car Seat Tolerance Screening (CSTS) failure and the association between test failure and all-cause 30-day postdischarge mortality or hospital readmission in a large, multicenter cohort of preterm infants receiving neonatal intensive care. STUDY DESIGN: This retrospective cohort study used the prospectively collected Optum Neonatal Database. Study infants were born at <37 weeks of gestation between 2010 and 2016. We identified independent predictors of CSTS failure and calculated the risk-adjusted odds of all-cause 30-day mortality or hospital readmission associated with test failure. RESULTS: Of 7899 infants cared for in 788 hospitals, 334 (4.2%) failed initial CSTS. Greater postmenstrual age at testing and African American race were independently associated with decreased failure risk. Any treatment with an antacid medication, concurrent use of caffeine or supplemental oxygen, and a history of failing a trial off respiratory support were associated with increased failure risk. The mean adjusted post-CSTS duration of hospitalization was 3.1 days longer (95% CI, 2.7-3.6) among the infants who failed the initial screening. Rates of 30-day all-cause mortality or readmission were higher among infants who failed the CSTS (2.4% vs 1.0%; P = .03); however, the difference was not significant after confounder adjustment (OR, 0.38; 95% CI, 0.11-1.31). CONCLUSION: CSTS failure was associated with longer post-test hospitalization but no difference in the risk-adjusted odds for 30-day mortality or hospital readmission. Whether CSTS failure unnecessarily prolongs hospitalization or results in appropriate care that prevents adverse postdischarge outcomes is unknown. Further research is needed to address this knowledge gap.

Putative Auditory-Evoked Neurophonic Measurements Using a Novel Signal Processing Technique: A Pilot Case Study.

With changes to cochlear implant candidacy and improvements in surgical technique, there is a need for accurate intraoperative assessment of low-frequency hearing thresholds during cochlear implantation. In electrocochleography, onset compound action potentials (CAPs) typically allow estimation of auditory threshold for frequencies above 1 kHz, but they are less accurate at lower frequencies. Auditory nerve neurophonic (ANN) waveforms, on the other hand, may overcome this limitation by allowing phase-locked neural activity to be tracked during a prolonged low-frequency stimulus rather than just at its onset (Henry, 1995). Lichtenhan et al. (2013) have used their auditory nerve overlapped waveform (ANOW) technique to measure these potentials from the round windows of cats and guinea pigs, and reported that in guinea pigs these potentials originate in the cochlear apex for stimuli below 70 dB SPL (Lichtenhan et al., 2014). Human intraoperative round window neurophonic measurements have been reported by Choudhury et al. (2012). We have done the same in hearing impaired awake participants, and present here the results of a pilot study in which we recorded responses evoked by 360, 525, and 725 Hz tone bursts from the cochlear promontory of one participant. We also present a modification to the existing measurement technique which halves recording time, extracting the auditory neurophonic by recording a single averaged waveform, and then subtracting from it a 180° group-delayed version of itself, rather than using alternating condensation and rarefaction sound stimuli. We cannot conclude that the waveforms we measured were purely neural responses originating from the apex of the cochlea: as with all neurophonic measurement procedures, the neural responses of interest cannot be separated from higher harmonics of the cochlear microphonic without forward masking, regardless of electrode location, stimuli or post-processing algorithm. In conclusion, the extraction of putative neurophonic waveforms can easily be incorporated into existing electrocochleographic measurement paradigms, but at this stage such measurements should be interpreted with caution.

Incorporating Patient and Caregiver Experiences Into Cardiovascular Clinical Trial Design.

Patient centeredness is a concept that is increasingly being viewed as essential for clinical research. A core principle involves a comprehensive assessment and integration of patient and caregiver perspectives into trial design. Importantly, this involves more than just soliciting feedback. Patients and caregivers are now considered vital members of the study team, even serving as coinvestigators who may help to conceive, plan, and develop the study; continue to direct the day-to-day conduct of the study; and fully participate in the dissemination of the study results. The Patient-Centered Outcomes Research Institute offers substantial funding to support this approach, but getting started, particularly at institutions that lack a robust community engagement infrastructure, can be daunting. In this Special Communication, successful methods that have been used by researchers to engage patients, caregivers, and the broader health care community in the research process are outlined, and examples of currently funded studies that have fully engaged key stakeholders are described. Although trials are designed to assess efficacy and effectiveness and inform future implementation and dissemination, this Special Communication emphasizes methods to ensure trial results are relevant to and understood by the individuals and groups that they are intended to impact. Critical next steps in this new research approach are also discussed. In doing so, this will inspire future cardiovascular research that evaluates not only traditional end points, such as mortality and readmission, but also emphasizes true patient-centered outcomes, including quality of life, knowledge and satisfaction, caregiver burden, time tradeoffs, and out-of-pocket costs.

Appointment of racial/ethnic minority directors: Ethnic matching or visibility threat?

The purpose of this study is to identify the industry and community-level compositional factors that influence the appointment of racial/ethnic minorities to corporate boards. We derived hypotheses from two theoretical perspectives: ethnic matching and visibility threat. Our analysis relied on data from seventy-three Standard & Poor's 500 companies between 1980 and 2000. We find important differences between and among racial/ethnic groups in terms of the mechanisms that shape board appointments. Consistent with the ethnic matching perspective, we find that the representation of Black and Hispanic board directors is strongly predicted by the racial/ethnic composition of the industry's labor force. Contrary to the visibility threat perspective, however, we find that the appointment of Asian directors is strongly predicted by the ethnic composition of the community where the firm is located.

Diversity begets diversity? The effects of board composition on the appointment and success of women CEOs.

Previous research on the effects of leadership diversity on firm outcomes has produced inconsistent and inconclusive findings. While some scholars argue that diversity increases organizational equity and enhances performance, others argue that diversity increases conflict, reduces cooperation and harms performance. This study tests the impact of a variety of compositional factors on firm outcomes. Specifically, we analyze whether and how board composition affects the advancement and mobility of women CEOs and firm performance. Our analysis relies on a unique data set of all Chief Executive Officers (CEOs) and Board of Directors (BODs) in Fortune 500 companies over a ten-year period. We find a marginally significant positive relationship between board diversity and the likelihood of a woman being appointed CEO. We further find that board diversity significantly and positively influences the post-promotion success of women CEOs. Our findings suggest that board composition is critical for the appointment and success of women CEOs, and increasing board diversity should be central to any organizational diversity efforts.

Outcomes in mild acute ischemic stroke treated with intravenous thrombolysis: a retrospective analysis of the Get With the Guidelines-Stroke registry.

IMPORTANCE: Mild strokes have been poorly represented in thrombolytic trials and only a few series have reported outcomes after treatment with intravenous (IV) recombinant tissue plasminogen activator (rtPA) after mild stroke. OBJECTIVE: To report treatment complications and short-term outcomes in patients with mild stroke who have received treatment with IV rtPA. DESIGN, SETTING, AND PARTICIPANTS: Retrospective analysis of patients treated in the emergency department of hospitals that use the Get With the Guidelines-Stroke registry, a prospectively collected quality improvement registry used by hospitals across the United States. Patients were those admitted between May 1, 2010, and October 1, 2012, with acute ischemic stroke within 4.5 hours from symptom onset and a baseline National Institutes of Health Stroke Scale score of 5 or less. Univariable and multivariable analyses were performed to identify factors independently associated with discharge outcomes and treatment complications. INTERVENTION: Intravenous rtPA. MAIN OUTCOMES AND MEASURES: Treatment complications included symptomatic intracranial hemorrhage, life-threatening or serious systemic hemorrhage, other serious complications, and undetermined complications. The short-term outcomes analyzed were in-hospital mortality, discharge to home, independent ambulation at discharge, and length of stay. RESULTS: Among 33,995 patients who arrived within 4.5 hours of symptom onset and were treated with IV rtPA, 7621 (22.4%) had a National Institutes of Health Stroke Scale score of 5 or less and 5910 had complete data for analysis. Treatment complications were infrequent: symptomatic intracranial hemorrhage, 1.8%; life-threatening or serious systemic hemorrhage, 0.2%; other serious complications, 1.8%; and complications of undetermined cause, 2.4%. Mortality was low (1.3%), but at discharge 30.3% could not ambulate independently, 29.4% could not go directly home, and 73.0% had a length of stay of 3 days or longer. Worse short-term outcomes were seen in older patients, African American patients, diabetic patients, and those who arrived by ambulance, after hours, or with a higher National Institutes of Health Stroke Scale score. CONCLUSIONS AND RELEVANCE: Many patients with ischemic stroke treated with IV rtPA have a mild stroke. Symptomatic intracranial hemorrhage is infrequent, but approximately 30% of these patients are unable to return directly home or ambulate independently at discharge. Additional studies are needed to identify strategies to improve the outcomes in patients with mild stroke who receive thrombolysis.

Acoustic impedance rhinometry (AIR): a technique for monitoring dynamic changes in nasal congestion.

We describe a simple and inexpensive method for monitoring nasal air flow resistance using measurement of the small-signal acoustic input impedance of the nasal passage, similar to the audiological measurement of ear drum compliance with acoustic tympanometry. The method requires generation of a fixed sinusoidal volume-velocity stimulus using ear-bud speakers, and an electret microphone to monitor the resultant pressure fluctuation in the nasal passage. Both are coupled to the nose via high impedance silastic tubing and a small plastic nose insert. The acoustic impedance is monitored in real-time using a laptop soundcard and custom-written software developed in LabView 7.0 (National Instruments). The compact, lightweight equipment and fast time resolution lends the technique to research into the small and rapid reflexive changes in nasal resistance caused by environmental and local neurological influences. The acoustic impedance rhinometry technique has the potential to be developed for use in a clinical setting, where the need exists for a simple and inexpensive objective nasal resistance measurement technique.

Rotation of the eyes (not the head) potentiates the postauricular muscle response.

OBJECTIVE: The authors investigated how eye and head rotation modulate the human postauricular muscle response (PAMR), to determine the optimal strategy for potentiating the PAMR, or minimizing it to reduce contamination of small neurogenic responses. DESIGN: The authors recorded the PAMR evoked by binaural bipolar clicks (50 dB SL, 360 µsec per phase with 53-msec interval) from behind the right ear of 12 normally hearing adults, and attempted to enhance it with (a) voluntary ear contraction alone, (b) head rotation alone (with the eyes forward-directed and tracking a target attached to the head), or (c) by lateral eye movement alone (toward the right measurement side, with the head facing forward). RESULTS: When the head alone was rotated with eyes fixed relative to the head, the PAMR increased only slightly in some subjects, as did the ongoing electromyography (EMG) (probably due to EMG activity from nearby neck muscles). On returning the head to the forward control position, the PAMR dropped rapidly to control amplitudes. When the eyes alone were rotated, both the EMG and the PAMR increased markedly in most subjects, and returning the eyes to their control position produced a gradual return to control amplitudes. Voluntary PAM contraction (in those subjects who could accomplish it) increased the EMG tone and the PAMR amplitude concomitantly, with vigorous voluntary PAM contraction saturating the PAMR but not the EMG. CONCLUSION: Head rotation alone was not effective in potentiating the PAMR when lateral eye movement relative to the head was avoided during the head rotation maneuver. When lateral eye movement was controlled appropriately, the PAMR could be potentiated reliably, or reliably avoided when recording smaller neurogenic responses. If head rotation was used to optimize the PAMR without explicit control of eye movement, a false impression of variability was produced.