Wildland Fire Emission Sampling at Fishlake National Forest, Utah Using an Unmanned Aircraft System.

Emissions from a stand replacement prescribed burn were sampled using an unmanned aircraft system (UAS, or "drone") in Fishlake National Forest, Utah, U.S.A. Sixteen flights over three days in June 2019 provided emission factors for a broad range of compounds including carbon monoxide (CO), carbon dioxide (CO2), nitric oxide (NO), nitrogen oxide (NO2), particulate matter < 2.5 microns in diameter (PM2.5), volatile organic compounds (VOCs) including carbonyls, black carbon, and elemental/organic carbon. To our knowledge, this is the first UAS-based emission sampling for a fire of this magnitude, including both slash pile and crown fires resulting in wildfire-like conditions. The burns consisted of drip torch ignitions as well as ground-mobile and aerial helicopter ignitions of large stands comprising over 1,000 ha, allowing for comparison of same-species emission factors burned under different conditions. The use of a UAS for emission sampling minimizes risk to personnel and equipment, allowing flexibility in sampling location and ensuring capture of representative, fresh smoke constituents. PM2.5 emission factors varied 5-fold and, like most pollutants, varied inversely with combustion efficiency resulting in lower emission factors from the slash piles than the crown fires.

Single centre experience of bilateral gracilis flap perineal reconstruction following extra-levator abdominoperineal excision.

AIM: A variety of tissue flaps have been described for the closure of perineal wounds following abdominoperineal excision of the rectum (APE) or exenteration for locally advanced/recurrent rectal cancer and salvage surgery for anal cancer. The aim of this study was to demonstrate the utility of the bilateral pedicled gracilis muscle flaps (BPGMFs) as a reconstruction option in these patients. This is of particular benefit when using a laparoscopic approach for the abdominal component of the operation, avoiding disruption of the abdominal wall and risk of herniation with other reconstruction options, e.g. vertical rectus abdominis myocutaneous flaps. METHOD: This is a retrospective single centre case series of patients who underwent reconstruction of perineal defects using BPGMFs using a novel weave technique, from January 2008 to August 2017. RESULTS: There were 25 patients (16 female), with a median follow-up of 19 months (3-102). The indications for BPGMFs were cancer resection (21) and perineal hernia (4). The median length of stay was 14 days (6-60). All-cause mortality was 36% within the follow-up period. A healed perineal wound was achieved in 72% of patients within 30 days (84% of patients received neoadjuvant chemoradiotherapy). The overall donor site complication rate was 20% (including infection, dehiscence, numbness, haematoma and seroma) and 28% for the perineal site (including infection, dehiscence and prolapse). CONCLUSIONS: BPGMFs provide an important option for reconstruction of the perineum particularly with a minimally invasive approach or with two stomas.

Closure of the perineal defect after abdominoperineal excision for rectal adenocarcinoma - ACPGBI Position Statement.

BACKGROUND: Perineal wound morbidity is common following abdominoperineal excision of the rectum (APE). There is no consensus on the optimum perineal reconstruction method after APE, and in particular 'extra-levator APE' (ELAPE). METHODS: A systematic review of the PubMed, Embase and Cochrane databases was performed. This position statement formulated clinical questions and graded the evidence to make recommendations. RESULTS: Perineal wound complications may be higher following ELAPE compared to 'conventional APE (cAPE)' however there is insufficient evidence to recommend cAPE over ELAPE with regards to the impact upon perineal wound healing. The majority of cAPE studies have used primary closure with varying complication rates reported. Where concerns regarding perineal wound healing exist, myocutaneous flap closure may be considered as an alternative method. There is minimal available evidence on perineal mesh reconstruction following cAPE. Primary closure, mesh use and myocutaneous flap reconstruction following ELAPE has been reported although variations in definitions and low-quality of available evidence limit comparison. There is insufficient evidence to recommend one particular method of perineal closure after ELAPE. Primary perineal closure is likely to have a higher risk of perineal herniation. Myocutaneous flaps and biological mesh have been effectively used in ELAPE closure. There is insufficient evidence to support one particular type of flap or mesh. Perineal wound complication rates are significantly increased when neo-adjuvant radiotherapy is delivered, regardless of surgical technique. There is no evidence that laparoscopy reduces APE perineal wound complications. CONCLUSION: This position statement updates clinicians on current evidence around perineal closure after APE surgery.

Effect of sodium molybdate supplementation on high concentrations of Cu in liver of yearling bulls.

AIM: To determine the impact of sodium molybdate treatment, given weekly, on concentrations of Cu in liver, activity of liver enzymes, and weight gain over 4 weeks, in yearling bulls with elevated concentrations of Cu in liver. METHODS: The study was carried on two commercial grazing farms in the Otago region of New Zealand in yearling Friesian bulls (n=150 on Farm A and n=49 on Farm B) with mean concentration of Cu in liver >3,000 µmol/kg fresh weight. On Day 0, all animals were weighed and half were systematically allocated to treatment with sodium molybdate (3 mg/kg liveweight on Farm A and 7 mg/kg liveweight on Farm B); the remainder received no treatment (Control). Sodium molybdate was given as a drench weekly for 4 weeks and all animals were weighed again on Day 28. Ten animals on each farm (five from each treatment group) were systematically selected for blood sampling and liver biopsies on Days 0 and 28. Samples were analysed for concentrations of Cu in plasma, vitamin B12 in serum, activities of γ-glutamyl transferase, aspartate aminotransferase and glutamate dehydrogenase in serum, and concentrations of Cu and vitamin B12 in liver. Separate multivariable linear models were used to compare the change in outcome variables between Days 0 and 28 between bulls that had been drenched with sodium molybdate or not. RESULTS: On Farm A, mean concentrations of Cu in liver on Day 28, as a percentage of concentrations on Day 0, for the control group was 55 (95% CI=40-73)% and for the treatment group was 73 (95% CI=43-111)%. On Farm B, the equivalent mean for the control group was 75 (95% CI=42-131)% and for the treatment group was 85 (95% CI=38-134)%. The multivariable linear models indicated that the changes in concentrations of Cu in liver, activities of liver enzymes and weight gain between Days 0 and 28 did not differ between the bulls treated or not with sodium molybdate (p>0.18). CONCLUSIONS AND CLINICAL RELEVANCE: Treatment with sodium molybdate in one bolus at weekly intervals for 4 weeks did not affect concentrations of Cu in liver, activity of liver enzymes or weight gain in animals with high concentrations of Cu liver on two farms.

Lubricin/proteoglycan 4 increases in both experimental and naturally occurring equine osteoarthritis.

OBJECTIVE: The goals of this study were (1) to quantify proteoglycan 4 (PRG4) gene expression; (2) to assess lubricin immunostaining; and (3) to measure synovial fluid lubricin concentrations in clinical and experimental models of equine carpal osteoarthritis (OA). DESIGN: Lubricin synovial fluid concentrations and cartilage and synovial membrane PRG4 expression were analyzed in research horses undergoing experimental OA induction (n = 8) and in equine clinical patients with carpal OA (n = 58). Lubricin concentrations were measured using a custom sandwich enzyme-linked immunosorbent assay, and PRG4 expression was quantified using qRT-PCR. Lubricin immunostaining was assessed in synovial membrane and osteochondral sections in the experimental model. RESULTS: Lubricin concentrations increased in synovial fluid following induction of OA, peaking at 21 days post-operatively in OA joints vs sham-operated controls (331 ± 69 µg/mL vs 110 ± 19 µg/mL, P = 0.001). Lubricin concentrations also increased in horses with naturally occurring OA as compared to control joints (152 ± 32 µg/mL vs 68 ± 4 µg/mL, P = 0.003). Synovial membrane PRG4 expression increased nearly 2-fold in naturally occurring OA (P = 0.003), whereas cartilage PRG4 expression decreased 2.5-fold (P = 0.025). Lubricin immunostaining was more pronounced in synovial membrane from OA joints as compared to controls, with intense lubricin localization to sites of cartilage damage. CONCLUSIONS: Although PRG4 gene expression decreases in OA cartilage, synovial membrane PRG4 expression, synovial fluid lubricin concentrations and lubricin immunostaining all increase in an equine OA model. Lubricin may be elevated to protect joints from post-traumatic OA.

Longitudinal instability of the forearm.

The Essex Lopresti lesion is a rare triad of injury to the radial head, interosseous membrane of the forearm and distal radio-ulnar joint, which results in longitudinal instability of the radius. If unrecognized this leads to chronic pain and disability which is difficult to salvage. Early recognition and appropriate treatment is therefore desirable to prevent long-term problems. The aim of this article is to review the pathoanatomy of longitudinal radius instability and use the existing literature and authors' experience to provide recommendations for recognition and treatment of acute and chronic forearm instability, including description of the author's technique for interosseous membrane reconstruction.

Magnetars: the physics behind observations. A review.

Magnetars are the strongest magnets in the present universe and the combination of extreme magnetic field, gravity and density makes them unique laboratories to probe current physical theories (from quantum electrodynamics to general relativity) in the strong field limit. Magnetars are observed as peculiar, burst-active x-ray pulsars, the anomalous x-ray pulsars (AXPs) and the soft gamma repeaters (SGRs); the latter emitted also three 'giant flares', extremely powerful events during which luminosities can reach up to 10(47) erg s(-1) for about one second. The last five years have witnessed an explosion in magnetar research which has led, among other things, to the discovery of transient, or 'outbursting', and 'low-field' magnetars. Substantial progress has been made also on the theoretical side. Quite detailed models for explaining the magnetars' persistent x-ray emission, the properties of the bursts, the flux evolution in transient sources have been developed and confronted with observations. New insight on neutron star asteroseismology has been gained through improved models of magnetar oscillations. The long-debated issue of magnetic field decay in neutron stars has been addressed, and its importance recognized in relation to the evolution of magnetars and to the links among magnetars and other families of isolated neutron stars. The aim of this paper is to present a comprehensive overview in which the observational results are discussed in the light of the most up-to-date theoretical models and their implications. This addresses not only the particular case of magnetar sources, but the more fundamental issue of how physics in strong magnetic fields can be constrained by the observations of these unique sources.

Direct observation of the coherent nuclear response after the absorption of a photon.

How molecules convert light energy to perform a specific transformation is a fundamental question in photophysics. Ultrafast spectroscopy reveals the kinetics associated with electronic energy flow, but little is known about how absorbed photon energy drives nuclear motion. Here we used ultrabroadband transient absorption spectroscopy to monitor coherent vibrational energy flow after photoexcitation of the retinal chromophore. In the proton pump bacteriorhodopsin, we observed coherent activation of hydrogen-out-of-plane wagging and backbone torsional modes that were replaced by unreactive coordinates in the solution environment, concomitant with a deactivation of the reactive relaxation pathway.

Firing patterns in a conductance-based neuron model: bifurcation, phase diagram, and chaos.

Responding to various stimuli, some neurons either remain resting or can fire several distinct patterns of action potentials, such as spiking, bursting, subthreshold oscillations, and chaotic firing. In particular, Wilson's conductance-based neocortical neuron model, derived from the Hodgkin-Huxley model, is explored to understand underlying mechanisms of the firing patterns. Phase diagrams describing boundaries between the domains of different firing patterns are obtained via extensive numerical computations. The boundaries are further studied by standard instability analyses, which demonstrates that the chaotic neural firing could develop via period-doubling and/or period- adding cascades. Sequences of the firing patterns often observed in many neural experiments are also discussed in the phase diagram framework developed. Our results lay the groundwork for wider use of the model, especially for incorporating it into neural field modeling of the brain.

Long-term follow-up of bilateral gracilis reconstruction following extra-levator abdominoperineal excision.

INTRODUCTION: Colorectal operations such as an extra-levator abdominoperineal (elAPE) excision for locally advanced or recurrent cancer create a significant perineal tissue deficit. Options for perineal reconstruction include bilateral pedicled gracilis muscle flaps (BPGMF). Fashioning the gracili into a 'weave' creates a muscular sling that supports pelvic contents and is a novel technique. Our series reports the outcomes of the BPGMF in 50 patients undergoing surgery for pelvic cancer. METHOD: This is a retrospective, single-centre study of patients undergoing reconstruction of perineal defects using BPGMF. All surgeries took place between January 2008 and February 2021. The primary outcome measured was perineal wound healing. The secondary outcomes measured were complications of surgical sites and length of hospital stay (short term), flap integrity on follow-up imaging and functional outcomes (long term). RESULTS: Fifty patients underwent perineal reconstruction using BPGMF (26 males). The median age was 62 years. The 30-day mortality was 2% (n = 1). The average follow-up period was 2 years. Complete perineal wound healing was 86% (42/49) at outpatient follow-up. Complication rates for the donor site and reconstructed site were 14% and 22%, respectively. Complications included infection (2% donor site, 12% perineum), haematoma (4% donor site), dehiscence (2% donor site, 4% perineum) and seroma (3% donor site, 2% perineum). CONCLUSION: BPGMF offers a reliable and technically simple muscle flap to reconstruct large perineal defects. The muscle flap integrity appears maintained on follow-up imaging despite a lack of flap monitoring tools. This cohort had minimal functional impairment following BPGMF.

Pyrocarbon proximal interphalangeal joint arthroplasty: minimum two-year follow-up.

PURPOSE: To report the outcome and complications from pyrocarbon proximal interphalangeal (PIP) joint arthroplasty at a minimum of 2 years of follow-up. METHODS: A retrospective case review was performed on 72 patients with an average age of 57 years, and a total of 97 pyrocarbon PIP joint arthroplasties. Patient demographics, diagnosis, implant revisions, and other repeat surgeries were recorded. Subjective outcome was evaluated at latest follow-up with the Disabilities of the Arm, Shoulder, and Hand score; Patient Evaluation Measure; and visual analog scores of pain, satisfaction, and appearance. Objective outcomes included PIP joint range of motion, grip strength, and radiographic assessment of alignment and loosening. RESULTS: The principal diagnosis was primary osteoarthritis in 43 patients(60%), posttraumatic arthritis in 14 (19%), rheumatoid arthritis in 9 (13%), and psoriatic arthritis in 6 (8%). The average follow-up was 60 months (range, 24-108 mo). Twenty-two of 97 digits (23%) had repeat surgery without revision, and 13 digits (13%) had revision at an average of 15 months. There were no significant differences in preoperative and postoperative range of motion. The average Disabilities of the Arm, Shoulder, and Hand score was 22, and the average pain score was zero. Implant migration and loosening was observed but was not related to clinical outcome or revision. CONCLUSIONS: The survival of pyrocarbon PIP joint arthroplasty was 85% (83 of 97) at 5 years of follow-up, with high patient satisfaction. Patients should be advised that the procedure achieves good relief of pain but does not improve range of motion. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Treatment of acute distal biceps tendon ruptures - A survey of the British Elbow and Shoulder Society surgical membership.

Background: Acute distal biceps tendon ruptures result in weakness and deformity. While in other jurisdictions the rate of surgical repair has outpaced rises in incidence, UK practice for distal biceps tendon ruptures is unknown. The aim of this survey was to characterise current UK clinical practice. Methods: An online survey was sent to the surgeon members of the British Elbow and Shoulder Society. Questions covered respondent demographics, clinical decision making, surgical experience and willingness to be involved in future research. Results: A total of 242 surgeons responded; 99% undertook acute distal biceps tendon repairs with 83% repairing at least half of all distal biceps tendon ruptures, and 84% of surgeons would have their own, hypothetical, acute distal biceps tendon rupture repaired in their dominant arm and 67% for their non-dominant arm. Patient age, occupation and restoration of strength were the commonest factors underpinning a recommendation of surgical fixation. Most surgeons (87%) supported a national trial to study operative and non-operative treatments. Conclusions: UK upper limb surgeons currently advise surgical repair of acute distal biceps tendon ruptures for the majority of their patients. This is despite a paucity of evidence to support improved outcomes following surgical, rather than non-operative, management. There is a clear need for robust clinical evaluation in this area.

Spontaneous cerebral embolisation in asymptomatic and recently symptomatic patients with TIA/Minor stroke.

OBJECTIVES: Spontaneous embolisation (SE) detected using Transcranial Doppler (TCD) after a Transient Ischaemic Attack (TIA)/Minor stroke is an independent predictor of recurrent stroke. There are, however limited data on the differential prevalence of SE in the first few days/weeks after onset of symptoms. METHOD: 156 consecutive patients (symptomatic n = 123, asymptomatic n = 33) underwent Carotid Endarterectomy (CEA) during an 18 month period and had an accessible window permitting 30 min of pre-operative TCD monitoring. A prospective study was conducted with assessors blinded to clinical status. RESULTS: Spontaneous embolisation was detected in 31 symptomatic patients (25%) of which 1/1 (100%), 14/35 (40%), 8/37 (22%) and in 8/50 (16%) patients presented within 48 h, 3-7 days, 8-14 days and >14 days respectively from the index clinical event. SE occurred in only 6% of asymptomatic patients. Out of 31 symptomatic patients with SE, seven (22.6%) suffered recurrent cerebrovascular events following admission as opposed to 11/92 patients (11.9%) who had no evidence of spontaneous embolisation after admission (OR 2.2 (95% CI 0.8-6.1))(P = 0.2) CONCLUSION: Patients presenting for CEA in the hyperacute period after onset of TIA/Minor stroke have a high incidence of SE. Patients with SE had a 23% risk of recurrent cerebrovascular events. These data support the current drive towards expedited CEA in recently symptomatic patients.

Fetal immunization of baboons induces a fetal-specific antibody response.

Neonates face a high risk of infection because of the immaturity of their immune systems. Although the transplacental transfer of maternal antibodies to the fetus may convey improved postnatal immunity, this transfer occurs late in gestation and may fail to prevent in utero infection. Both fetal immunization and in utero exposure to antigen can result in a state of immunologic tolerance in the neonate. Tolerance induction of fetal and premature infant lymphocytes has become a paradigm for neonatal responsiveness. However, fetal IgM responses have been demonstrated to maternal immunization with tetanus toxoid and to congenital infections such as rubella, toxoplasma, cytomegalovirus and human immunodeficiency virus. Moreover, 1-week-old infants can respond to standard pediatric vaccination, and neonates immunized with polysaccharide antigens do not develop immunologic tolerance. Here, direct immunization of the baboon fetus with recombinant hepatitis B surface antigen produced a specific fetal IgG antibody response. No specific maternal antibody response was detected, eliminating the possibility of vertical antibody transmission to the fetus. Some infants also responded to later vaccinations with hepatitis B surface antigen, indicating that no immunological tolerance was induced by prior fetal immunization. These results characterize the ability of the fetal immune system to respond to in utero vaccination. We demonstrate that active fetal immunization can serve as a safe and efficient vaccination strategy for the fetus and neonate.

The long-term strength of Europe and its implications for plate-forming processes.

Field-based geological studies show that continental deformation preferentially occurs in young tectonic provinces rather than in old cratons. This partitioning of deformation suggests that the cratons are stronger than surrounding younger Phanerozoic provinces. However, although Archaean and Phanerozoic lithosphere differ in their thickness and composition, their relative strength is a matter of much debate. One proxy of strength is the effective elastic thickness of the lithosphere, Te. Unfortunately, spatial variations in Te are not well understood, as different methods yield different results. The differences are most apparent in cratons, where the 'Bouguer coherence' method yields large Te values (> 60 km) whereas the 'free-air admittance' method yields low values (< 25 km). Here we present estimates of the variability of Te in Europe using both methods. We show that when they are consistently formulated, both methods yield comparable Te values that correlate with geology, and that the strength of old lithosphere (> or = 1.5 Gyr old) is much larger (mean Te > 60 km) than that of younger lithosphere (mean Te < 30 km). We propose that this strength difference reflects changes in lithospheric plate structure (thickness, geothermal gradient and composition) that result from mantle temperature and volatile content decrease through Earth's history.

Pathological femoral fracture caused by primary bone tumour: a population-based study.

This population-based study aimed to analyse the demographic, clinical and histological features of patients with a malignant primary bone tumour of the femur presenting with a pathological fracture. Eighty-four patients were identified from a prospectively gathered national tumour database between 1960 and 2004. Demographic data, presenting features, tumour location, histological diagnosis, treatment, local recurrence, metastasis and survival data were gathered. An estimate of the annual incidence was obtained using population data from the General Register Office and was 0.4 per million population per annum. The mean age was 56 years (range 4-87 years) with a bimodal distribution and 46% were men or boys. Forty-one percent of patients presented with a history of trauma. The average duration of symptoms before presentation was 1-3 months. The most common histological diagnoses were osteosarcoma (14 patients) and Paget's sarcoma (12 patients). The local recurrence rate was 38% and the overall five-year survival was 22%. The prognosis was made worse by local tumour recurrence, the development of metastasis and age at diagnosis greater than 21 years. Limb salvage surgery did not alter the prognosis. Patients who present with pathological fracture of a primary malignant bone tumour, carry a poor prognosis in all tumour types and no improvement in survival was identified over the period of the study.

The conformation of acetylcholine at its target site in the membrane-embedded nicotinic acetylcholine receptor.

The conformation of the neurotransmitter acetylcholine bound to the fully functional nicotinic acetylcholine receptor embedded in its native membrane environment has been characterized by using frequency-selective recoupling solid-state NMR. Six dipolar couplings among five resolved (13)C-labeled atoms of acetylcholine were measured. Bound acetylcholine adopts a bent conformation characterized with a quaternary ammonium-to-carbonyl distance of 5.1 A. In this conformation, and with its orientation constrained to that previously determined by us, the acetylcholine could be docked satisfactorily in the agonist pocket of the agonist-bound, but not the agonist-free, crystal structure of a soluble acetylcholine-binding protein from Lymnaea stagnali. The quaternary ammonium group of the acetylcholine was determined to be within 3.9 A of five aromatic residues and its acetyl group close to residues C187/188 of the principle and residue L112 of the complementary subunit. The observed >C O chemical shift is consistent with H bonding to the nicotinic acetylcholine receptor residues gammaY116 and deltaT119 that are homologous to L112 in the soluble acetylcholine-binding protein.