Factors affecting the dormancy and germination of bleeding heart [Lamprocapnos spectabilis (L.) Fukuhara] seeds

Information on the optimal conditions to promote the germination of Lamprocapnos spectabilis (L.) Fukuhara seeds is limited; consequently, this study was conducted to establish the requirements to break seed dormancy and promote germination. The selected seeds had morphophysiological dormancy and had not begun embryo development. To study the dormancy breaking and embryo development processes, seeds were subjected to constant or changing temperature treatments during moist stratification. High temperature and humidity resulted in vigorous embryo growth, with the longest embryos occurring after 1 month of incubation at 20 °C. At 4 °C, the seeds required incubation period of at least 3 months to germinate. Embryo growth and germination were higher with changing high and low temperatures than under a constant temperature, and changing temperatures also considerably changed the endogenous hormone levels, embryo development and germination. Bioactive gibberellin (GA) content was higher in seeds incubated at 20 °C for 1 month, then at 4 °C for 2 months. The content of endogenous abscisic acid in seeds subjected to the same treatment decreased by 97.6% compared with that of the untreated seeds. Embryo growth and seed germination require changing high and low temperatures; however, exogenous GA₃ could substitute for high temperatures, as it also causes accelerated germination. In this study, the seeds of L. spectabilis were identified as an intermediate simple type, a sub-level of morphophysiologically dormant seeds.

A Simple Scoring Algorithm That Predicts Abscesses in Adults with Community-Onset Klebsiella pneumoniae Bacteremia: Hypermucoviscosity Matters

Introduction

Klebsiella pneumoniae is a pathogen commonly found in community-onset bacteremia. It causes an invasive syndrome that is frequently presented by metastatic infections and abscesses elsewhere and that is necessary for surgical or drainage intervention. To achieve a scoring algorithm to identify patients with community-onset K. pneumoniae bacteremia (CoKPB) who are at risk for abscess occurrences, a retrospective cohort study consisting of adults with CoKPB was conducted.

Methods

A 6-year cohort study consisting of adults having community-onset monomicrobial K. pneumoniae bacteremia was conducted. In addition to clinical variables collected from medical records, the hypermucoviscosity (HMV)-related gene (rmpA and magA) and an HMV phenotype were integrated into the proposed scoring algorithm.

Results

Of the 258 eligible adults, only 79 (30.6%) had abscesses related to bacteremia. Besides the presence of magA (ie, capsular serotype K1) and the HMV-phenotype, five clinical predictors were significantly associated with abscesses in a multivariate analysis: male gender, comorbidities with diabetes mellitus or neurological disorders, recent chemotherapy, and high c-reactive protein levels. Together, these predictors were used to calculate the CoKPB abscess score. Based on the scoring algorithm, a cut-off value of +2 yielded the high sensitivity (93.7%) and the acceptable specificity (50.8%); the area under the ROC curve was 0.83.

Conclusion

A simple scoring algorithm that has substantial sensitivity and satisfactory specificity was proposed and the importance of the HMV phenotype or capsular K1 serotype was emphasized. The proposed predictive model needs external validation, but this scoring algorithm might be convenient and useful for clinicians.

Impact of climate change on disaster events in metropolitan cities -trend of disasters reported by Taiwan national medical response and preparedness system

BACKGROUND

Taiwan is geographically located in a zone that is vulnerable to earthquakes, typhoons, floods, and landslide hazards and has experienced various disasters. Six Regional Emergency Medical Operation Centers (REMOCs) are integrated and administered by the Ministry of Health and Welfare (MOHW) to be responsible for emergency situations during disastrous events, such as the emission of chemical toxicants, traffic accidents, industrial materials containment, and typhoons.

OBJECTIVE

To analyze events reported by the six REMOCs during the 2014 to 2018 for the government policy reference.

METHODS

Data were collected from injured and death toll reports provided by local designated hospitals in the emergency medical reporting system. Disaster events were categorized into three categories: natural disaster (NDs), disasters associated with technology (DTs), and disasters associated with security/violence/others (DSVOs). The three categories were further subdivided into sub-categories. Variables considered for trend analyses included the number of wounded and deaths, event characteristics, date/time, and triage. The frequency of disaster events among the six REMOCs was compared using the chi-square test. We used the global information system (GIS) to describe the distribution of events in Taiwan metropolitan cities. The α-level was set at 0.05.

RESULTS

Of 580 events during the study period, the distribution of disaster characteristics in the jurisdictions of the six REMOCs were different. The majority of disaster events were DTs (64.5%), followed by NDs (24.5%) and DSVOs (11.0%). Events for the three disaster categories in the six REMOCs were different (χ²-test, p < 0.001). Furthermore, for the Taipei branch (Northern Taiwan), other NDs, especially heatwaves and cold spells, were most reported in New Taipei City (92.2%) and showed an increasing annual trend; for the Kaohsiung branch (Southern Taiwan), DT events were the most reported, especially in Kaohsiung City; and for the Taichung branch (Central Taiwan), DSVOs were the most reported, especially in Taichung City.

CONCLUSION

Our data revealed that extreme weather precautions reported in the Taipei branch were increasing. Disaster characteristics were different in each metropolitan city. Upgrading the ability to respond to natural disasters is ineluctable.

Randomly Hopping Majorana Fermions in the Diluted Kitaev System α-Ru_{0.8}Ir_{0.2}Cl_{3}

dc and ac magnetic susceptibility, magnetization, specific heat, and Raman scattering measurements are combined to probe low-lying spin excitations in α-Ru_{1-x}Ir_{x}Cl_{3} (x≈0.2), which realizes a disordered spin liquid. At intermediate energies (ℏω>3  meV), Raman spectroscopy evidences linearly ω-dependent Majorana-like excitations, obeying Fermi statistics. This points to robustness of a Kitaev paramagnetic state under spin vacancies. At low energies below 3 meV, we observe power-law dependences and quantum-critical-like scalings of the thermodynamic quantities, implying the presence of a weakly divergent low-energy density of states. This scaling phenomenology is interpreted in terms of the random hoppings of Majorana fermions. Our results demonstrate an emergent hierarchy of spin excitations in a diluted Kitaev honeycomb system subject to spin vacancies and bond randomness.

Definitive Cefazolin Therapy for Stabilized Adults with Community-Onset Escherichia coli, Klebsiella Species, and Proteus mirabilis Bacteremia: MIC Matters

Background: Cefazolin is in vitro active against wild isolates of Escherichia coli, Klebsiella species, and Proteus mirabilis (EKP), but clinical evidence supporting the contemporary susceptibility breakpoint issued by the Clinical and Laboratory Standards Institute (CLSI) are limited. Methods: Between 2010 and 2015, adults with monomicrobial community-onset EKP bacteremia with definitive cefazolin treatment (DCT) at two hospitals were analyzed. Cefazolin minimum inhibitory concentrations (MICs) were correlated with clinical outcomes, including primary (treatment failure of DCT) and secondary (30-day mortality after bacteremia onset, recurrent bacteremia, and mortality within 90 days after the end of DCT) outcomes. Results: Overall, 466 bacteremic episodes, including 340 (76.2%) episodes due to E. coli, 90 (20.2%) Klebsiella species, and 16 (3.6%) P. mirabilis isolates, were analyzed. The mean age of these patients was 67.8 years and female-predominated (68.4%). A crude 15- and 30-day mortality rate was 0.7% and 2.2%, respectively, and 11.2% experienced treatment failure of DCT. A significant linear-by-linear association of cefazolin MICs, with the rate of treatment failure, 30-day crude mortality, recurrent bacteremia or 90-day mortality after the DCT was present (all γ = 1.00, p = 0.01). After adjustment, the significant impact of cefazolin MIC breakpoint on treatment failure and 30-day crude mortality was most evident in 2 mg/L (>2 mg/L vs. ≤2 mg/L; adjusted hazard ratio, 3.69 and 4.79; p < 0.001 and 0.02, respectively). Conclusion: For stabilized patients with community-onset EKP bacteremia after appropriate empirical antimicrobial therapy, cefazolin might be recommended as a definitive therapy for cefazolin-susceptible EKP bacteremia, based on the contemporary CLSI breakpoint.

Beneficial effects of early empirical administration of appropriate antimicrobials on survival and defervescence in adults with community-onset bacteremia

Background

Bloodstream infections are associated with high morbidity and mortality, both of which contribute substantially to healthcare costs. The effects of early administration of appropriate antimicrobials on the prognosis and timing of defervescence of bacteremic patients remain under debate.

Methods

In a 6-year retrospective, multicenter cohort, adults with community-onset bacteremia at the emergency departments (EDs) were analyzed. The period from ED arrival to appropriate antimicrobial administration and that from appropriate antimicrobial administration to defervescence was regarded as the time-to-appropriate antibiotic (TtAa) and time-to-defervescence (TtD), respectively. The primary study outcome was 30-day mortality after ED arrival. The effects of TtAa on 30-day mortality and delayed defervescence were examined after adjustment for independent predictors of mortality, which were recognized by a multivariate regression analysis.

Results

Of the total 3194 patients, a TtAa-related trend in the 30-day crude (γ = 0.919, P = 0.01) and sepsis-related (γ = 0.909, P = 0.01) mortality rate was evidenced. Each hour of TtAa delay was associated with an average increase in the 30-day crude mortality rate of 0.3% (adjusted odds ratio [AOR], 1.003; P < 0.001) in the entire cohort and 0.4% (AOR, 1.004; P < 0.001) in critically ill patients, respectively, after adjustment of independent predictors of 30-day crude mortality. Of 2469 febrile patients, a TtAa-related trend in the TtD (γ = 0.965, P = 0.002) was exhibited. Each hour of TtAa delay was associated with an average 0.7% increase (AOR, 1.007; P < 0.001) in delayed defervescence (TtD of ≥ 7 days) after adjustment of independent determinants of delayed defervescence. Notably, the adverse impact of the inappropriateness of empirical antimicrobial therapy (TtAa > 24 h) on the TtD was noted, regardless of bacteremia severity, bacteremia sources, or causative microorganisms.

Conclusions

The delay in the TtAa was associated with an increasing risk of delayed defervescence and 30-day mortality for adults with community-onset bacteremia, especially for critically ill patients. Thus, for severe bacteremia episodes, early administration of appropriate empirical antimicrobials should be recommended.

Definitive Cefazolin Treatment for Community-Onset Enterobacteriaceae Bacteremia Based on the Contemporary CLSI Breakpoint: Clinical Experience of a Medical Center in Southern Taiwan

Cefazolin is traditionally active against Escherichia coli, Klebsiella species, and Proteus mirabilis (EKP) isolates. The Clinical and Laboratory Standards Institute (CLSI) has twice updated cefazolin susceptibility breakpoints for EKP since 2010, but its role in the definitive treatment of cefazolin-susceptible EKP bacteremia remains debated. To assess its efficacy as a definitive agent, the 8-year cohort study consisted of 941 adults with monomicrobial cefazolin-susceptible EKP bacteremia, based on the CLSI criteria issued in 2019, was retrospectively established in a medical center. Based on the definitive antimicrobial prescription, eligible patients were categorized into the cefazolin (399 patients, 42.4%) and broader-spectrum antibiotic (BSA) (542, 57.6%) groups. Initially, fewer proportions of patients with fatal comorbidities (the McCabe classification) and the critical illness (a Pitt bacteremia score ≥4) at the onset and day 3 of the bacteremia episode were found in the cefazolin group, compared to the BSA group. After propensity-score matching, no significant difference of patient proportions between the cefazolin (345 patients) and BSA (345) groups was observed, in terms of the elderly, types and severity of comorbidities, bacteremia severity at the onset and day 3, major bacteremia sources, and the 15-day and 30-day crude mortality. In early outcomes, lengths of time to defervescence, intravenous (IV) antimicrobial administration, and hospitalization were similar in the two matched groups; lower costs of IV antimicrobial administration were observed in the cefazolin group. Notably, for late outcomes, lower proportions of post-treatment infections caused by antimicrobial-resistant pathogens (ARPs) and post-treatment mortality rates were evidenced in the cefazolin group. Conclusively, cefazolin is definitively efficacious and cost-effective for adults with community-onset cefazolin-susceptible EKP bacteremia in this one-center study, compared to BSAs. However, a prospective multicenter study should be conducted for external validation with other communities.

Search for Subsolar Mass Ultracompact Binaries in Advanced LIGO's Second Observing Run

We present a search for subsolar mass ultracompact objects in data obtained during Advanced LIGO's second observing run. In contrast to a previous search of Advanced LIGO data from the first observing run, this search includes the effects of component spin on the gravitational waveform. We identify no viable gravitational-wave candidates consistent with subsolar mass ultracompact binaries with at least one component between 0.2  M_{⊙}-1.0  M_{⊙}. We use the null result to constrain the binary merger rate of (0.2  M_{⊙}, 0.2  M_{⊙}) binaries to be less than 3.7×10^{5}  Gpc^{-3} yr^{-1} and the binary merger rate of (1.0  M_{⊙}, 1.0  M_{⊙}) binaries to be less than 5.2×10^{3}  Gpc^{-3} yr^{-1}. Subsolar mass ultracompact objects are not expected to form via known stellar evolution channels, though it has been suggested that primordial density fluctuations or particle dark matter with cooling mechanisms and/or nuclear interactions could form black holes with subsolar masses. Assuming a particular primordial black hole (PBH) formation model, we constrain a population of merging 0.2  M_{⊙} black holes to account for less than 16% of the dark matter density and a population of merging 1.0  M_{⊙} black holes to account for less than 2% of the dark matter density. We discuss how constraints on the merger rate and dark matter fraction may be extended to arbitrary black hole population models that predict subsolar mass binaries.

Timing of follow-up blood cultures for community-onset bacteremia

Bacteremia is associated with high morbidity and mortality, but the utility and optimal timing of follow-up blood cultures (FUBCs) remain undefined. To assess the optimal timing of FUBCs related to appropriate antibiotic therapy (AAT), adults with community-onset bacteremia and FUBCs after bacteremia onset were retrospectively studied during the 6-year period in two hospitals. Based on the time gap between the initiation of AAT and FUBC sampling, 1,247 eligible patients were categorized as FUBCs prior to AAT (65 patients, 5.2%), 0–3 days (202, 16.2%), 3.1–6 days (470, 37.7%), 6.1–9 days (299, 24.0%), and ≥9 days (211, 16.9%) after AAT. The prognostic impact of the growth of the same bacteria in FUBCs on 30-day mortality was evidenced only in patients with FUBCs at 3.1–6 days after AAT (adjusted odds ratio [AOR], 3.75; P < 0.001), not in those with FUBCs prior to AAT (AOR, 2.86; P = 0.25), 0–3 days (AOR, 0.39; P = 0.08), 6.1–9 days (AOR, 2.19; P = 0.32), and ≥9 days (AOR, 0.41; P = 0.41) of AAT, after adjusting independent factors of 30-day mortality recognized by the multivariable regression in each category. Conclusively, persistent bacteremia in FUBCs added prognostic significance in the management of adults with community-onset bacteremia after 3.1–6 days of AAT.

Differential effects of inappropriate empirical antibiotic therapy in adults with community-onset gram-positive and gram-negative aerobe bacteremia

Bacteremia is associated with high morbidity and mortality, which contribute substantially to health care costs. A beneficial influence of appropriate empirical antimicrobial therapy (EAT) on patient outcome is evidenced; However, the evidence highlighting a comparison of clinical manifestations and of the effects of inappropriate EAT between Gram-positive and Gram-negative bacteremia is insufficient. In a retrospective 6-year cohort study, the total 2053 adults (Gram-positive, 566; Gram-negative 1487) presenting with community-onset monomicrobial aerobes bacteremia were recruited. Inappropriate EAT was defined as the first dose of an appropriate antimicrobial agent not being administered within the first 24 h after blood cultures were drawn. Although the bacteremia severity (a Pitt bacteremia score) at onset, comorbidity severity (the McCabe-Johnson classification), and 28-day mortality rate were similar in the two groups. Furthermore, after adjustment of independent predictors of 28-day mortality respectively recognized by the multivariate regression model in Gram-negative and Gram-positive groups, the Kaplan-Meier curve and Cox regression analysis revealed a significant difference (adjust odds ratio [AOR], 2.68; P < 0.001) between appropriate and inappropriate EAT in the Gram-negative group, but not in the Gram-positive group (AOR, 1.54; P = 0.06). Conclusively, patients with Gram-positive and Gram-negative bacteremia exhibited the similar presentation in bacteremia severity, but a greater impact of inappropriate EAT on survival of patients with Gram-negative aerobe bacteremia was evidenced.

Clinical Benefit of Empiric High-Dose Levofloxacin Therapy for Adults With Community-onset Enterobacteriaceae Bacteremia

PURPOSE

Levofloxacin is commonly prescribed to treat varied community-acquired gram-negative infections; knowledge of the therapeutic efficacies of high-dose (HD) administration is helpful to improve patient care.

METHODS

In this 6-year cohort, adults with community-onset Enterobacteriaceae bacteremia were retrospectively studied in 2 hospitals. To overcome the confounding factors in the dosage choice of empiric administration, patients receiving empiric intravenous HD (750 mg/d) therapy were matched with those receiving the conventional dose (CD; 500 mg/d) by using individual propensity scores, calculated by the independent predictors of 30-day crude mortality.

FINDINGS

Initially, more patients with critical illness (Pitt bacteremia score [PBS] ≥4) at bacteremia onset and comorbid malignancies and the higher 15- and 30-day mortality rate were recorded in 136 patients receiving HD therapy, compared to 103 receiving CD therapy. After appropriate matching, differences in patient demographic and clinical characteristics between the HD (n = 103) and CD (n = 103) groups were nonsignificant. Consequently, crude mortality rates at 3, 15, or 30 days after onset of bacteremia did not differ. However, the period of time to defervescence, total intravenous antimicrobial administration, and hospital stay was shorter in the HD group than in the CD group. Similarly, regardless if patients had more critical illness (PBS ≥2) or stabilized illness (PBS <2), the advantage of empiric HD therapy on defervescence remained significant. Within 60 days after discontinuation of intravenous levofloxacin therapy, the proportion of recurrent bacteremia, posttreatment overall infections, and posttreatment crude mortality was similar between the HD and CD groups.

IMPLICATIONS

For adults with community-onset Enterobacteriaceae bacteremia, empiric administration of HD levofloxacin was as effective as CD levofloxacin in reducing mortality and, notably, led to more rapid defervescence compared with CD administration.

Tests of General Relativity with GW170817

The recent discovery by Advanced LIGO and Advanced Virgo of a gravitational wave signal from a binary neutron star inspiral has enabled tests of general relativity (GR) with this new type of source. This source, for the first time, permits tests of strong-field dynamics of compact binaries in the presence of matter. In this Letter, we place constraints on the dipole radiation and possible deviations from GR in the post-Newtonian coefficients that govern the inspiral regime. Bounds on modified dispersion of gravitational waves are obtained; in combination with information from the observed electromagnetic counterpart we can also constrain effects due to large extra dimensions. Finally, the polarization content of the gravitational wave signal is studied. The results of all tests performed here show good agreement with GR.

Validation of MEDS score in predicting short-term mortality of adults with community-onset bacteremia

BACKGROUND

The Mortality in Emergency Department Sepsis (MEDS) score can be used to stratify ED patients with suspected infections according to mortality risk. However, it has yet to be externally validated for patients having bloodstream infections.

METHODS

We retrospectively computed clinical information for the MEDS score, Pitt bacteremia score (PBS), Charlson comorbidity index (CCI), and McCabe-Jackson comorbid classification (MJCC) for adults with community-onset bacteremia. The MEDS score was validated by the comparisons with the following scoring systems: the PBS, CCI, MJCC, PBS plus MJCC, and PBS plus CCI. We evaluated goodness-of-fit statistics and c-statistics as measures of model calibration and discrimination, respectively.

RESULTS

Of 2328 adults, a good calibration for 28-day crude mortality was obtained only in the MEDS score and PBS plus MJCC; a higher c-statistic (0.870, P < 0.001) were achieved by the MEDS score, compared to the PBS, CCI MJCC, PBS plus MJCC, and PBS plus CCI. A high c-statistic was observed in two combinative scoring system: the PBS plus CCI (0.855, P < 0.001) and PBS plus MJCC (0.843, P < 0.001). According to the Kaplan-Meier curves, 28-day crude mortality significantly differed between patients with scores equal to or higher than selected cutoff values and those with scores lower than selected cutoff values: 10 in the MEDS score and 5 in the PBS plus MJCC, respectively.

CONCLUSION

The MEDS score is an excellent predictor of short-term outcomes in patients with community-onset bacteremia because it provides estimates with higher calibration and discrimination than those of the other scoring systems.

Exotic Low-Energy Excitations Emergent in the Random Kitaev Magnet Cu_{2}IrO_{3}

We report on magnetization M(H), dc and ac magnetic susceptibility χ(T), specific heat C_{m}(T) and muon spin relaxation (μSR) measurements of the Kitaev honeycomb iridate Cu_{2}IrO_{3} with quenched disorder. In spite of the chemical disorders, we find no indication of spin glass down to 260 mK from the C_{m}(T) and μSR data. Furthermore, a persistent spin dynamics observed by the zero-field muon spin relaxation evidences an absence of static magnetism. The remarkable observation is a scaling relation of χ[H,T] and M[H,T] in H/T with the scaling exponent α=0.26-0.28, expected from bond randomness. However, C_{m}[H,T]/T disobeys the predicted universal scaling law, pointing towards the presence of additional low-lying excitations on the background of bond-disordered spin liquid. Our results signify a many-faceted impact of quenched disorder in a Kitaev spin system due to its peculiar bond character.

Effect of probiotics on fecal excretion, colonization in internal organs and immune gene expression in the ileum of laying hens challenged with Salmonella Enteritidis

A study was conducted to evaluate the supplementation of probiotics on Salmonella colonization in the ceca and various internal organs as well as immune response in laying hens challenged with Salmonella enterica serovar Enteritidis (SE). Thirty-two 46-wk-old White Leghorns (W-36) were housed individually in wired laying cages under 16L:8D lighting schedule. Hens were challenged individually with nalidixic acid resistant Salmonella Enteritidis (SENAR) after which time they were grouped into four treatments: T1 = SENAR unchallenged control, T2 = SENAR challenged control, T3 = SENAR challenged + 0.05% probiotics (Lactobacillus plantarum), and T4 = SENAR challenged + 0.1% probiotics. All hens, including T1, were euthanized and sampled for the liver with gall bladder (L/GB), ileum, ovary, spleen, and ceca on 7-days post-infection (dpi). Fecal screening was performed on individual hens at both 3 and 6 dpi. No difference was detected between the treatments in cecal SENAR enumeration, and the mean log 10 cfu/gm of SENAR in the ceca was 3.7 for all three treatments. The prevalence of SENAR was lowest for ovary in all treatments and was highest in the spleen. However, there were no significant differences among the treatments in the internal organs. There was no significant difference in the fecal shedding among the treatments on either 3 or 6 dpi, with incidence of positive feces higher at 3 dpi compared to 6 dpi (100 vs. 70% to 80%). SENAR challenge resulted in significant upregulation (P < 0.05) of interleukin (IL)-1β, 6, 10, interferon gamma (IFN-γ), and toll-like receptor (TLR)-4 mRNA expression. Highest level of probiotics resulted in a significant decrease in IFN-γ and elevation of IL-6 and IL-10 gene expression in the ileum. However, IL-1B and TLR-4 gene expression were not different from the SENAR challenge control. This study reveals that there was important regulation of immune genes by probiotics supplementation.

Constraining the p-Mode-g-Mode Tidal Instability with GW170817

We analyze the impact of a proposed tidal instability coupling p modes and g modes within neutron stars on GW170817. This nonresonant instability transfers energy from the orbit of the binary to internal modes of the stars, accelerating the gravitational-wave driven inspiral. We model the impact of this instability on the phasing of the gravitational wave signal using three parameters per star: an overall amplitude, a saturation frequency, and a spectral index. Incorporating these additional parameters, we compute the Bayes factor (lnB_{!pg}^{pg}) comparing our p-g model to a standard one. We find that the observed signal is consistent with waveform models that neglect p-g effects, with lnB_{!pg}^{pg}=0.03_{-0.58}^{+0.70} (maximum a posteriori and 90% credible region). By injecting simulated signals that do not include p-g effects and recovering them with the p-g model, we show that there is a ≃50% probability of obtaining similar lnB_{!pg}^{pg} even when p-g effects are absent. We find that the p-g amplitude for 1.4  M_{⊙} neutron stars is constrained to less than a few tenths of the theoretical maximum, with maxima a posteriori near one-tenth this maximum and p-g saturation frequency ∼70  Hz. This suggests that there are less than a few hundred excited modes, assuming they all saturate by wave breaking. For comparison, theoretical upper bounds suggest ≲10^{3} modes saturate by wave breaking. Thus, the measured constraints only rule out extreme values of the p-g parameters. They also imply that the instability dissipates ≲10^{51}  erg over the entire inspiral, i.e., less than a few percent of the energy radiated as gravitational waves.

P77 Type II PEG fractures: collar or no collar

Objectives

Type 2 peg fractures are known to have low fusion rates but most are elderly with comorbidities and not fit for surgery. Increasingly, clinicians want to stop using hard collars due to its complications, but with little supporting evidence. We aim to provide data to add to this debate.

Design

Single centre cohort study.

Subjects

145 consecutive patients referred to a Major Trauma Centre as type 2 peg fracture.

Methods

All patients referred with a suspected peg fracture between March 2015 and December 2017 were included. All imaging were assessed and case notes reviewed for patient demographics, fracture management, complications and outcomes.

Results

102 cases were peg fractures (mean age=80 years). 92 (90.2%) were managed conservatively with a hard collar (mean of 87 days). 37% developed symptoms from the collar, namely pain, stiffness and non-tolerance. Bony union was achieved in only 39.1% of patients with increasing age being an independent risk factor (p<0.001). Of the 56 patients who did not have bony union, there were no reported symptoms and 90% were discharged without a collar. 2 patients were offered but declined fixation and neither reported any on-going symptoms.

Conclusions

This study adds to the body of evidence that fusion rates are low, and collar complications are not insignificant when type 2 peg fractures are treated in a hard collar. However, outcomes are good regardless of union, potentially rendering the collar unnecessary. We aim to conduct a randomised prospective study to further investigate.

Search for Subsolar-Mass Ultracompact Binaries in Advanced LIGO's First Observing Run

We present the first Advanced LIGO and Advanced Virgo search for ultracompact binary systems with component masses between 0.2  M_{⊙}-1.0  M_{⊙} using data taken between September 12, 2015 and January 19, 2016. We find no viable gravitational wave candidates. Our null result constrains the coalescence rate of monochromatic (delta function) distributions of nonspinning (0.2  M_{⊙}, 0.2  M_{⊙}) ultracompact binaries to be less than 1.0×10^{6}  Gpc^{-3}  yr^{-1} and the coalescence rate of a similar distribution of (1.0  M_{⊙}, 1.0  M_{⊙}) ultracompact binaries to be less than 1.9×10^{4}  Gpc^{-3}  yr^{-1} (at 90% confidence). Neither black holes nor neutron stars are expected to form below ∼1  M_{⊙} through conventional stellar evolution, though it has been proposed that similarly low mass black holes could be formed primordially through density fluctuations in the early Universe and contribute to the dark matter density. The interpretation of our constraints in the primordial black hole dark matter paradigm is highly model dependent; however, under a particular primordial black hole binary formation scenario we constrain monochromatic primordial black hole populations of 0.2  M_{⊙} to be less than 33% of the total dark matter density and monochromatic populations of 1.0  M_{⊙} to be less than 5% of the dark matter density. The latter strengthens the presently placed bounds from microlensing surveys of massive compact halo objects (MACHOs) provided by the MACHO and EROS Collaborations.

Effects of Fabric Counts and Weave Designs on the Properties of Laminated Woven Kenaf/Carbon Fibre Reinforced Epoxy Hybrid Composites

The effects of different fabric materials namely weave designs (plain and satin) and fabric counts (5 × 5 and 6 × 6) on the properties of laminated woven kenaf/carbon fibre reinforced epoxy hybrid composites were evaluated. The hybrid composites were fabricated from two types of fabric, i.e., woven kenaf that was made from a yarn of 500tex and carbon fibre, by using vacuum infusion technique and epoxy resin as matrix. The panels were tested for tensile, flexural, and impact strengths. The results have revealed that plain fabric is more suitable than satin fabric for obtaining high tensile and impact strengths. Using a fabric count of 5 × 5 has generated composites that are significantly higher in flexural modulus as compared to 6 × 6 which may be attributed to their structure and design. The scanned electron micrographs of the fractured surfaces of the composites demonstrated that plain woven fabric composites had better adhesion properties than satin woven fabric composites, as indicated by the presence of notably lower amount of fibre pull out.

GW170817: Measurements of Neutron Star Radii and Equation of State

On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were neutron stars that are described by the same equation of state and have spins within the range observed in Galactic binary neutron stars. Our analysis employs two methods: the use of equation-of-state-insensitive relations between various macroscopic properties of the neutron stars and the use of an efficient parametrization of the defining function p(ρ) of the equation of state itself. From the LIGO and Virgo data alone and the first method, we measure the two neutron star radii as R_{1}=10.8_{-1.7}^{+2.0}  km for the heavier star and R_{2}=10.7_{-1.5}^{+2.1}  km for the lighter star at the 90% credible level. If we additionally require that the equation of state supports neutron stars with masses larger than 1.97  M_{⊙} as required from electromagnetic observations and employ the equation-of-state parametrization, we further constrain R_{1}=11.9_{-1.4}^{+1.4}  km and R_{2}=11.9_{-1.4}^{+1.4}  km at the 90% credible level. Finally, we obtain constraints on p(ρ) at supranuclear densities, with pressure at twice nuclear saturation density measured at 3.5_{-1.7}^{+2.7}×10^{34}  dyn cm^{-2} at the 90% level.