Underwater channel estimation exploiting multipath feature morphology.

Real-time accurate channel estimation has been an ongoing challenge because of diverse oceanic events that cause rapid fluctuations of high-energy multipath activity across the delay spread. This work leverages current compressed sensing and sparse optimization techniques with topological signal processing to improve estimation time and localize channel estimation to salient parts of the delay spread. This work improves the estimation time by tracking the channel as a union of overlapping multipath and other scattering events, which are modeled as "feature braids" in the delay-time domain. A channel feature braid may be intuitively visualized as the topologically connected trajectory of a group of channel delay taps, which represent the support of dominant or persistent scattering events, e.g., surface bounce multipath scattering. We present algorithms that harness support-constrained mixed norm optimization techniques to track the evolving support of channel feature braids. We validate our channel feature tracking algorithm independently in experimental field data as well as BELLHOP channel simulations across a diversity of oceanic conditions. This work shows that braiding used in estimation can improve estimation time and track high-energy events that develop within the delay vs time channel representation.

An exploration of the impact of SARS-CoV-2 (COVID-19) restrictions on marginalised groups in the UK.

BACKGROUND: To contain the spread of COVID-19 within the UK over the past year, there have been a series of local and national lockdowns. These restrictions are likely to have impacted upon the health and well-being of marginalised groups who rely on now closed social and community support services to stay healthy. An understanding of the experiences of marginalised people is important; therefore, this study aimed to explore the impact of the COVID-19 restrictions on the health and well-being of marginalised groups in the UK. METHODS: In summer 2020, a rapid telephone survey was conducted by trained, trusted volunteers with 76 participants who were from marginalised groups. As part of this survey, 64 participants consented to describe their experience of lockdown. These case studies were thematically analysed to identify patterns of meaning. RESULTS: Findings indicate that lockdown led to the deterioration of health of participants, impacted adversely on their socio-economic positions and affected access to food and essential supplies. In addition, government public health messaging was considered confusing and inadequate. CONCLUSIONS: This study highlights the need for pathways into services which support marginalised groups to remain accessible during periods of restrictions and essential supplies and food to be mapped and protected for marginalised individuals within our local communities.

Language abnormality in deaf people with schizophrenia: a problem with classifiers.

INTRODUCTION: Although there is evidence for language abnormality in schizophrenia, few studies have examined sign language in deaf patients with the disorder. This is of potential interest because a hallmark of sign languages is their use of classifiers (semantic or entity classifiers), a reference-tracking device with few if any parallels in spoken languages. This study aimed to examine classifier production and comprehension in deaf signing adults with schizophrenia. METHOD: Fourteen profoundly deaf signing adults with schizophrenia and 35 age- and IQ-matched deaf healthy controls completed a battery of tests assessing classifier and noun comprehension and production. RESULTS: The patients showed poorer performance than the healthy controls on comprehension and production of both nouns and entity classifiers, with the deficit being most marked in the production of classifiers. Classifier production errors affected handshape rather than other parameters such as movement and location. CONCLUSIONS: The findings suggest that schizophrenia affects language production in deaf patients with schizophrenia in a unique way not seen in hearing patients.

Segmental spinal dysgenesis: a report of early surgical intervention and outcome in a 14-month-old child.

Segmental spinal dysgenesis is a rare spinal deformity that is the result of failure of formation resulting in some cases spondyloptosis and neurological dysfunction usually at the thoracolumbar junction. There is little known concerning surgical intervention and timing in these patients. The goal of this case report is to present a case involving 14 months old diagnosed with segmental spinal dysgenesis with stenosis at the thoracolumbar junction soon after birth, treated with definitive posterior spinal fusion and subsequent follow-up.

Standardised versus Individualised Parenteral Nutrition. Further Food for Thought.

Parenteral Nutrition may be prescribed as a standard PN (SPN) formulation or as an individualised PN (IPN) formulation. SPN may have advantages in terms of rapid availability, less prescription errors, decreased risk of infection and cost savings but IPN, specifically tailored to an infants needs, may achieve better outcomes in terms of nutrient intake and weight gain. The aim of our study was to determine if VLBW infants in our NICU benefited from receiving IPN over currently available SPN solutions. Our findings were that VLBW infants prescribed IPN received significantly more amino acid (28%), glucose (6%), energy (11%) and calcium (8%) from the aqueous phase of PN than had they received a similar volume of SPN. The benefits were seen over all the days for which PN was administered. In conclusion, IPN was found to offer significant benefits to our VLBW infants. Modifications to currently available SPN would result in better SPN formulations. Our study also supported the recent recommendation to reduce the calcium:phosphate ratio in PN solutions to avoid early hypophosphataemia.

Imaging of gunshot injuries in a west Dublin teaching hospital--a ten year review.

There has been an increase in gun-related crime in Ireland over the last decade to gangland violence, especially in west Dublin. This places a burden on hospital services not previously encountered. The aim of this study was to examine the demographics of gunshot: injuries presenting to a Dublin teaching hospital, and the impact on radiology over a ten year period. A total of 65 gunshot injuries were seen. Mortality for high velocity wounds was much higher (10/23, 43%) than for low-velocity shotgun injuries (2/34, 6%).

Association of pain catastrophizing with labor pain and analgesia consumption in obstetrical patients.

INTRODUCTION: Pain catastrophizing is an exaggerated negative orientation to painful stimuli which in obstetric patients is associated with fear of overwhelming labor pain and negative pain-related outcomes. This study aimed to quantitatively examine the association of pain catastrophizing with maternal labor pain outcomes. METHODS: We conducted a prospective observational study of women admitted for a vaginal trial of labor. Subjects completed the 13-item Pain Catastrophizing scale (PCS) questionnaire (scored 0 to 52, higher scores representing greater catastrophizing). Pain was assessed at baseline and at request for neuraxial labor analgesia. Labor and postpartum pain intensity was assessed as the average area under the pain intensity by time curve. Pain at request for analgesia, labor pain, postpartum pain, analgesic consumption, and quality of recovery was compared between high (PCS ≥ 17) and low catastrophizing groups. RESULTS: Data from 138/157 (88%) subjects were included in the analysis. Median (IQR) pain scores at request for analgesia were 9 (8,10) and 8 (6,9), a difference of 1 (95% CI 0 to 2.5, P = 0.008) in high-catastrophizing and in low-catastrophizing groups, respectively. Adjusted pain during labor, postpartum pain and opioid analgesic use were not significantly different. High-catastrophizers reported less comfort, ability to mobilize and less control during hospitalization. Post-discharge there were no differences in pain or analgesic use. CONCLUSION: We did not observe greater labor or post-delivery pain or increased analgesic use in high-catastrophizing parturients. High catastrophizers reported greater pain when requesting analgesia, which is consistent with the role of catastrophizing in intensifying the experience of pain.

Transapical balloon dilation of cor triatriatum sinister in a cat.

A hybrid surgical approach was utilized to address cor triatriatum sinister in a 10-month-old castrated male domestic shorthair cat. Prior to surgery, open-mouth breathing occurred with exertion. The procedure was guided by transesophageal echocardiography and fluoroscopy. A minithoracotomy was performed, and the left atrial membrane was accessed via an introducer placed through the left ventricular apex. Sequential balloon dilations were performed, and the mean transmembrane gradient under anesthesia was reduced from 16 mmHg to 2.23 mmHg. Four months after surgery, the transmembrane mean gradient remained lower than prior to intervention. The cat tolerated surgery well and remains free of clinical signs nine months after surgery.

Palliation of abdominal aortic aneurysms in the endovascular era.

OBJECTIVES: To establish outcome of patients with abdominal aortic aneurysm (AAA) deemed unfit for repair. DESIGN: Retrospective non-randomised study. MATERIALS AND METHODS: Identification of males with >5.5 cm or females with >5.0 cm AAA turned down for elective repair between 01/01/2006-24/07/2009 from a prospective database. Comorbidities, reasons for non-intervention, aneurysm size, survival, use of CPEX (cardio-pulmonary exercise) testing and cause of death were analysed. Although well-established at the time, patients unfit for open operation were not considered for endovascular repair. RESULTS: Seventy two patients were unsuitable for AAA repair. Aneurysm size ranged from 5.3 cm to 12 cm. Functional status, comorbidity and patient preference determined decision to palliate. Sixty percent of patients were alive at study close. Aneurysm rupture was cause of death in 46%. CPEX testing was performed in 54%, whose mortality was 28%, vs. 54% in the non-CPEX group (P < 0.05). Median survival of patients with 5.1-6.0 cm AAA was 44 months and 11% died of rupture. Between 6.1 and 7.0 cm median survival was 26 months and 20% died of rupture. However, with >7 cm aneurysms, survival was 6 months and 43% ruptured. CONCLUSION: Under half the deaths in our comorbid cohort were due to rupture. However, decision to palliate may be revisited as risk-benefit ratio changes with aneurysm expansion.

Flashbulb memories in patients with temporal lobe epilepsy.

PURPOSE: Flashbulb memories (FMs) are vivid and stable autobiographical memories associated with learning surprising news of high emotional impact. Patients with temporal lobe epilepsy (TLE) can have autobiographical memory deficits. This is the first investigation of FMs in TLE applying a consistency measure of FM quality controlling for confabulation. METHOD: A sample of 12 patients with TLE and a matched group of 15 healthy controls (HCs) were tested on an FM test including a retest procedure. Scores of FM consistency were obtained by comparing answers across both testing occasions. RESULTS: In patients with TLE, FM consistency scores were significantly lower than in HCs. Exploratory subgroup analyses revealed FM deficits in both patients with left TLE and patients with right TLE compared with HCs. CONCLUSION: The present study indicates that the FMs of patients with TLE are less consistent than those of healthy control subjects. Future investigations with larger samples are desirable, especially regarding separate analyses of patients with left TLE and patients with right TLE.

Teaching Junior Medical Officers safe and effective prescribing.

Medication errors are an iatrogenic threat to patient safety, and recently graduated Junior Medical Officers (JMOs) are a common source of these errors. A ward-based, physician-led, small-group interactive teaching session was developed to improve JMOs competence in prescribing. The ability of JMOs to detect problems in mock medication charts before and after the teaching session was assessed, with the majority improving after the intervention, a result sustained on re-testing later in the year. The teaching sessions were well received by JMOs.

Virtual airway simulation to improve dexterity among novices performing fibreoptic intubation.

We developed a virtual reality software application (iLarynx) using built-in accelerometer properties of the iPhone(®) or iPad(®) (Apple Inc., Cupertino, CA, USA) that mimics hand movements for the performance of fibreoptic skills. Twenty novice medical students were randomly assigned to virtual airway training with the iLarynx software or no additional training. Eight out of the 10 subjects in the standard training group had at least one failed (> 120 s) attempt compared with two out of the 10 participants in the iLarynx group (p = 0.01). There were a total of 24 failed attempts in the standard training group and four in the iLarynx group (p < 0.005). Cusum analysis demonstrated continued group improvement in the iLarynx, but not in the standard training group. Virtual airway simulation using freely available software on a smartphone/tablet device improves dexterity among novices performing upper airway endoscopy.

A survey of United States obstetric anesthesiologists' perceived value of obstetric anesthesiology fellowship.

INTRODUCTION: Subspecialty training in obstetric anesthesiology is associated with improved patient outcomes and reduced anesthesia-related morbidity and mortality. Despite this, the demand for fellowship-trained obstetric anesthesiologists far exceeds the supply. This survey study aimed to evaluate the perceived value of obstetric anesthesiology subspecialty training on career trajectory, job satisfaction, quality of life, and job autonomy. METHODS: After Institutional Review Board approval, we conducted a cross-sectional study of fellowship-trained obstetric anesthesiologists in the United States of America. In March and April 2022, program directors of obstetric anesthesiology fellowships distributed an electronic survey link containing 29 multiple-choice questions to their program alumni. Survey content included respondent demographic characteristics, practice models, career information, and perceived value of an obstetric anesthesiology fellowship. RESULTS: We surveyed 217/502 (43%) fellowship-trained obstetric anesthesiologists with a response rate of 158/217 (73%). Most worked in urban, academic, and level IV perinatal health centers. The majority believed an obstetric anesthesiology fellowship was "extremely beneficial" (77%), enhanced quality of life (84%), improved the quality of patient care (99%), and was influential in helping obtain their first post-training job (86%). The perceived value of the fellowship included an enhanced career trajectory, a sense of purpose, improved job satisfaction, a sense of work community, lower burnout, involvement in maternal health initiatives, increased mentorship, and departmental leadership. CONCLUSION: In this survey study, fellowship-trained obstetric anesthesiologists perceived a positive impact of fellowship training on career trajectory, job protection and autonomy, quality of life, and job satisfaction. This information may be meaningful to trainees considering pursuing a fellowship and a career in obstetric anesthesiology.

The non-classical ArsR-family repressor PyeR (PA4354) modulates biofilm formation in Pseudomonas aeruginosa.

PyeR (PA4354) is a novel member of the ArsR family of transcriptional regulators and modulates biofilm formation in Pseudomonas aeruginosa. Characterization of this regulator showed that it has negative autoregulatory properties and binds to a palindromic motif conserved among PyeR orthologues. These characteristics are in line with classical ArsR-family regulators, as is the fact that PyeR is part of an operon structure (pyeR-pyeM-xenB). However, PyeR also exhibits some atypical features in comparison with classical members of the ArsR family, as it does not harbour metal-binding motifs and does not appear to be involved in metal perception or resistance. Hence, PyeR belongs to a subgroup of non-classical ArsR-family regulators and is the second ArsR regulator shown to be involved in biofilm formation.

Systemic metoclopramide to prevent postoperative nausea and vomiting: a meta-analysis without Fujii's studies.

Previous evidence suggested that 10 mg systemic metoclopramide is not effective to prevent postoperative nausea and/or vomiting (PONV) in patients receiving general anaesthesia. However, the evidence included data with questioned validity by the author Yoshitaka Fujii. The objective of the current study was to examine the effect of a systemic dose of 10 mg metoclopramide to prevent PONV. This quantitative systematic review was performed according to the PRISMA guidelines. A wide search was performed to identify randomized clinical trials that evaluated systemic 10 mg metoclopramide as a prophylactic agent to reduce PONV. Meta-analysis was performed using a random-effect model. Thirty trials evaluating the effect of 10 mg systemic metoclopramide in 3328 subjects on PONV outcomes were included. Metoclopramide reduced the incidence of 24 h PONV compared with control, odds ratio (OR) [95% confidence interval (CI)] of 0.58 (0.43-0.78), number needed to treat (NNT)=7.8. When evaluated as separate outcomes, metoclopramide also decreased the incidence of nausea over 24 h, OR (95% CI) of 0.51 (0.38-0.68), NNT=7.1, and vomiting over 24 h, OR (95% CI) of 0.51 (0.40-0.66), NNT=8.3. A post hoc analysis examining three studies with questioned validity performed by the author Yoshitaka Fujii that would meet criteria for inclusion in the current study did not demonstrate a significant benefit of metoclopramide compared with control on the incidence of 24 h PONV. Our findings suggest that metoclopramide 10 mg i.v. is effective to prevent PONV in patients having surgical procedures under general anaesthesia. Metoclopramide seems to be a reasonable agent to prevent PONV.

The association between allogeneic perioperative blood transfusion on tumour recurrence and survival in patients with advanced ovarian cancer.

OBJECTIVE: To evaluate the association between perioperative blood transfusion on the recurrence and survival of patient with advanced ovarian cancer. BACKGROUND: Cytoreductive surgery for ovarian cancer can be an extensive procedure often requiring allogeneic blood transfusions. Blood transfusions can have detrimental effects on immune function which can lead to a decrease in the organism ability to detect and destroy metastasis. METHODS: The study was a retrospective cohort investigation. Patients with advanced ovarian cancer (stage III) undergoing cytoreductive surgery were stratified by the need for perioperative blood transfusion. Allogeneic transfusions were non-leucodepleted. Primary outcome included time to recurrence and survival. Data were extracted from the gynaecology oncology database at Northwestern University. Times to event outcomes were evaluated by constructing Kaplan-Meyer curves and Cox regression. RESULTS: The charts of 136 subjects were evaluated. Seventy-six received blood transfusion. Median [95% confidence interval (CI)] time to recurrence for the non-transfusion group was longer, i.e. 17 (6-27) months, compared to 11 (8-14) months for the transfused group (P = 0.03). Median (95% CI) survival following surgery was longer in the non-transfused group, i.e. 58 (43-73) months, compared to 36 (28-44) months for the transfused group (P = 0.04). Cox regression showed that transfused subjects had shorter median times to recurrence and mortality after adjusting for age and tumour grade. CONCLUSIONS: There is an association between ovarian cancer recurrence and allogeneic perioperative blood transfusion in patients with advanced ovarian cancer undergoing cytoreductive surgery. These findings may have important implications in the perioperative management of those patients.

Critical limb ischaemia in the time of COVID-19: establishing ambulatory service provision.

INTRODUCTION: The coronavirus disease 2019 (COVID-19) pandemic enforced changes to healthcare services at a pace and extent not seen previously in the NHS. The Royal Devon and Exeter provides regional vascular surgery services. A consultant-led urgent 'hot clinic' was established, providing patients with ambulatory care. We aim to describe the service for critical limb ischaemia (CLI) before and during the COVID-19 pandemic, and evaluate this against recommended best practice. METHODS: Retrospective review of electronic databases and records of patients with CLI during a non-COVID vs COVID-19 period. Primary outcome measures were those established by guidance from the Vascular Society of Great Britain and Ireland. RESULTS: Non-COVID vs COVID-19: total patients n=97 vs 96, of which CLI patients n=29 vs 21. Median length of stay 15 vs 0 days (p<0.001); median time from referral to specialist review 0 vs 3 days (p<0.001); multidisciplinary team meeting (MDT) recorded 3% vs 29%; median time to intervention 6 vs 8 days; conservative management 52% vs 67%; endovascular 28% vs 10%; open surgery 21% vs 24%; 30-day survival 79% vs 76%. CONCLUSION: COVID-19 imposed a major change to the service for patients with CLI with a focus on ambulatory care pathways for diagnosis and intervention. We observe a significant reduction in overall length of stay with no clinically significant change in time to consultant review, time to imaging, overall management strategy or outcomes. The results of this study show that patients with CLI can be managed safely and effectively on an ambulatory basis in accordance with established best practice.

Mice lacking neutrophil elastase reveal impaired host defense against gram negative bacterial sepsis.

Neutrophil elastase (NE) is a potent serine proteinase whose expression is limited to a narrow window during myeloid development. In neutrophils, NE is stored in azurophil granules along with other serine proteinases (cathepsin G, proteinase 3 and azurocidin) at concentrations exceeding 5 mM. As a result of its capacity to efficiently degrade extracellular matrix, NE has been implicated in a variety of destructive diseases. Indeed, while much interest has focused on the pathologic effects of this enzyme, little is known regarding its normal physiologic function(s). Because previous in vitro data have shown that NE exhibits antibacterial activity, we investigated the role of NE in host defense against bacteria. Generating strains of mice deficient in NE (NE-/-) by targeted mutagenesis, we show that NE-/- mice are more susceptible than their normal littermates to sepsis and death following intraperitoneal infection with Gram negative (Klebsiella pneumoniae and Escherichia coli) but not Gram positive (Staphylococcus aureus) bacteria. Our data indicate that neutrophils migrate normally to sites of infection in the absence of NE, but that NE is required for maximal intracellular killing of Gram negative bacteria by neutrophils.

Dose ranging study on the effect of preoperative dexamethasone on postoperative quality of recovery and opioid consumption after ambulatory gynaecological surgery.

BACKGROUND: Glucocorticoids are commonly administered before ambulatory surgery, although their effects on quality of recovery are not well characterized. The purpose of this study was to evaluate the dose-dependent effects of dexamethasone on patient recovery using the Quality of Recovery 40 questionnaire (QoR-40) after ambulatory surgery. METHODS: This prospective, double-blind trial studied 106 female subjects undergoing outpatient gynaecological laparoscopy. Subjects were randomized to receive saline, dexamethasone 0.05 mg kg(-1) or dexamethasone 0.1 mg kg(-1) before induction. The primary outcome was global QoR-40 at 24 h. Postoperative pain, analgesic consumption, side-effects, and discharge time were also evaluated. RESULTS: Global median (IQR) QoR-40 after dexamethasone 0.1 mg kg(-1) 193 (192-195) was greater than dexamethasone 0.05 mg kg(-1) 179 (175-185) (P=0.004) or saline, 171 (160-182) (P<0.005). Median (IQR) morphine equivalents administered before discharge were 2.7 (0-6.3) mg after dexamethasone 0.1 mg kg(-1) compared with 5.3 (2.4-8.8) mg and 5.3 (2.7-7.8) mg after dexamethasone 0.05 mg kg(-1) and saline (P=0.02). Time to meet discharge criteria was 30 min shorter after dexamethasone 0.1 mg kg(-1) compared with saline (P=0.005). At 24 h, subjects receiving dexamethasone 0.1 mg kg(-1) had consumed less opioid analgesics, reported less sore throat, muscle pain, confusion, difficulty in falling asleep, and nausea compared with dexamethasone 0.05 mg kg(-1) and saline. CONCLUSIONS: Dexamethasone demonstrated dose-dependent effects on quality of recovery. Dexamethasone 0.1 mg kg(-1) reduced opioid consumption compared with dexamethasone 0.05 mg kg(-1), which may be beneficial for improving recovery after ambulatory gynaecological surgery.

Determination of residual antiplatelet activity of clopidogrel before neuraxial injections.

BACKGROUND: Guidelines recommend discontinuation of clopidogrel for 7 days before a neuraxial injection, while other directives suggest that 5 days might be adequate. We examined the time course of antiplatelet activity after clopidogrel discontinuation in patients undergoing epidural injections. METHODS: Thirteen patients were studied at baseline, 3, 5, and 7 days after discontinuation of clopidogrel. P(2)Y(12) determinations were performed using the VerifyNow(®) assay (Accumetrics, San Diego, CA, USA), and clot closure times with stimulation by collagen/epinephrine and collagen/adenosine diphosphate using the PFA-100(®) (Platelet Function Analyzer, Siemens Diagnostics, Deerfield, IL, USA). Repeated-measures ANOVA was used to evaluate P(2)Y(12) platelet reaction units, PFA-100 closure times, and per cent P(2)Y(12) inhibition values. Wilcoxon's signed-rank test was used to compare the frequencies of ≥30%, 11-29%, and ≤10% platelet inhibition between the baseline and subsequent sampling points after discontinuation of clopidogrel. RESULTS: On day 3 after clopidogrel discontinuation, two subjects had ≥30%, seven subjects had 11-29%, and four subjects had ≤10% platelet inhibition; the corresponding numbers were 0, 3, and 10 subjects on day 5 (P=0.04). There were no differences between the ≥30%, 11-29%, and <10% platelet inhibition groups between days 5 and 7 (0, 0, and 13 subjects, P=1.0). PFA-ADP closure times were normal throughout the study period except in one patient. CONCLUSIONS: These findings support the recommendation that discontinuation of clopidogrel for 5 days allows >70% of platelet function and might be adequate before a neuraxial injection is performed.