The Local Route of Administration of Dexamethasone in Impacted Mandibular Third Molar Surgery: A Systematic Review and Meta-analysis of Randomised Controlled Trials and a Critical Narrative Review on the Claimed Advantages of the Local Route

Introduction

The proponents of local route of Dexamethasone (DXM) administration for impacted mandibular 3rd molar (MM3) surgeries claim advantages over the traditional systemic routes. This systematic review and meta-analysis were aimed to determine whether the route of perioperative administration of DXM influences the inflammatory outcomes of MM3 surgeries.

Methodology

An electronic database search over a 25 year period of randomised trials of DXM in MM3 surgeries was conducted. The mean differences or standardised mean differences were extracted and pooled using the fixed or random-effects model.

Results

Of the sixteen selected trials, four were considered for a meta-analysis. There were no statistically significant differences in the inflammatory outcomes between the local and systemic routes of DXM.

Conclusion

The claimed advantages of the local route of DXM do not appear to be scientifically valid. Clinical trials supported with DXM plasma measurements are needed to confirm the absence of a systemic effect when DXM is administered locally.

Nonlinear Ringdown at the Black Hole Horizon

The gravitational waves emitted by a perturbed black hole ringing down are well described by damped sinusoids, whose frequencies are those of quasinormal modes. Typically, first-order black hole perturbation theory is used to calculate these frequencies. Recently, it was shown that second-order effects are necessary in binary black hole merger simulations to model the gravitational-wave signal observed by a distant observer. Here, we show that the horizon of a newly formed black hole after the head-on collision of two black holes also shows evidence of nonlinear modes. Specifically, we identify one quadratic mode for the l=2 shear data, and two quadratic ones for the l=4, 6 data in simulations with varying mass ratio and boost parameter. The quadratic mode amplitudes display a quadratic relationship with the amplitudes of the linear modes that generate them.

Multimode Quasinormal Spectrum from a Perturbed Black Hole

When two black holes merge, the late stage of gravitational wave emission is a superposition of exponentially damped sinusoids. According to the black hole no-hair theorem, this ringdown spectrum depends only on the mass and angular momentum of the final black hole. An observation of more than one ringdown mode can test this fundamental prediction of general relativity. Here, we provide strong observational evidence for a multimode black hole ringdown spectrum using the gravitational wave event GW190521, with a maximum Bayes factor of 56±1 (1σ uncertainty) preferring two fundamental modes over one. The dominant mode is the ℓ=m=2 harmonic, and the subdominant mode corresponds to the ℓ=m=3 harmonic. The amplitude of this mode relative to the dominant harmonic is estimated to be A_{330}/A_{220}=0.2_{-0.1}^{+0.2}. We estimate the redshifted mass and dimensionless spin of the final black hole as 330_{-40}^{+30}M_{⊙} and 0.86_{-0.11}^{+0.06}, respectively. We find that the final black hole is consistent with the no-hair theorem and constrain the fractional deviation from general relativity of the subdominant mode's frequency to be -0.01_{-0.09}^{+0.08}.

A study on H-score threshold for p16ink4a immunoperoxidase expression in squamous cell tumours of oral cavity

Background

Validity of various detection methods used are likely contributing factor to this wide variation of prevalence of HPV (0-73%) by using GP5/GP6/MY09/MY11 (L1) primer. PCR is a sensitive method but does not identify transcriptionally active High-risk Human papillomavirus and also does not indicate whether the virus is isolated from malignant tumour cells and non-neoplastic cells. P16ink4a Immunohistochemistry is a highly sensitive and Cost-effective surrogate marker for transcriptionally active high-risk HPV for oral cancer. Objective The aim of the present study was to evaluate the H-SCORE of p16 expression in the surface epithelial tumour sites of a large cohort of squamous cell carcinoma (SCC), severe dysplasia (SD). we sought to determine whether the p16 algorithm is reliable in Oral cavity SCC and severe dysplasia (SD).

Materials and Methods

This study used Immunohistochemistry in archival Formalin-fixed paraffin embedded specimens for assessment of p16 protein expression, cytoplasmic and nuclear staining intensity was categorized based on score (range, 0-3) and presence of tumour cell staining (0-100%).

Results

The majority of positive cases had low H-score of p16 staining except 3/161 (1.8%) cases of tongue SCC had positive for p16 with diffuse moderate staining with ≥2 scores. There were no significant differences in the distribution of demographic, exposure and histopathological characteristics between patients with and without P16 expression.

Conclusion

The present study demonstrated that p16 expression is a reliable HPV marker in the lateral border of the tongue with tonsil involvement but no other sites of the oral cavity. Further p16 IHC detection is required in large cohort of all sites of tongue squamous cell carcinoma studies to validate the marker of HPV.

Seeing is believing: the impact of RB on nuclear organization

The retinoblastoma tumor suppressor (RB) prevents G1 to S cell cycle transition by inhibiting E2F activity. This function requires that RB remains un- or underphosphorylated (the so-called active forms of RB). Recently, we showed that active forms of RB cause widespread changes in nuclear architecture that are visible under a microscope. These phenotypes did not correlate with cell cycle arrest or repression of the E2F transcriptional program, but appeared later, and were associated with the appearance of autophagy or in IMR-90 cells with senescence markers. In this perspective, we describe the relative timing of these RB-induced events and discuss the mechanisms that may underlie RB-induced chromatin dispersion. We consider the relationship between RB-induced dispersion, autophagy, and senescence and the potential connection between dispersion and cell cycle exit.

INFECTIOUS COMPLICATIONS IN COMPOUND MANDIBULAR FRACTURES UNDERGOING A DELAYED SURGICAL INTERVENTION - A PROSPECTIVE OBSERVATIONAL STUDY

The aim of this prospective study was to analyse if a delay in the time from injury to definitive surgical intervention of open reduction and internal fixation (ORIF) of compound mandibular fractures predisposed to an increase in postoperative infectious complications. ORIF beyond 72 hours from injury was considered to be delayed intervention. Postoperative surgical site infections (SSI) and non-infectious complications (NIC) were recorded. The Mann-Whitney U test was used to compare the delay in ORIF with SSI. The chi squared test/Fisher's exact test was used to find the association of the infectious complication status with predetermined risk factors. Eighty-three patients underwent a delayed ORIF with a median (range) of 8 (4-19) days. SSI was documented in eight patients (9.6%) and could be managed as outpatient medical and surgical intervention. Two patients needed repeat surgical intervention due to non-union of the fracture. The median (range) time to ORIF was 6.5 (5-12) days in patients who developed SSI; the Mann-Whitney U test did not show a statistically significant association between delayed ORIF and SSI (p = 0.7). The univariate analysis did not establish a significant relationship between SSI and predetermined risk factors. The delay to definitive surgical intervention was not observed to be an independent attributing factor in postoperative infectious complications of compound mandibular fractures.

Active RB causes visible changes in nuclear organization

RB restricts G1/S progression by inhibiting E2F. Here, we show that sustained expression of active RB, and prolonged G1 arrest, causes visible changes in chromosome architecture that are not directly associated with E2F inhibition. Using FISH probes against two euchromatin RB-associated regions, two heterochromatin domains that lack RB-bound loci, and two whole-chromosome probes, we found that constitutively active RB (ΔCDK-RB) promoted a more diffuse, dispersed, and scattered chromatin organization. These changes were RB dependent, were driven by specific isoforms of monophosphorylated RB, and required known RB-associated activities. ΔCDK-RB altered physical interactions between RB-bound genomic loci, but the RB-induced changes in chromosome architecture were unaffected by dominant-negative DP1. The RB-induced changes appeared to be widespread and influenced chromosome localization within nuclei. Gene expression profiles revealed that the dispersion phenotype was associated with an increased autophagy response. We infer that, after cell cycle arrest, RB acts through noncanonical mechanisms to significantly change nuclear organization, and this reorganization correlates with transitions in cellular state.

News from Horizons in Binary Black Hole Mergers

In a binary black hole merger, it is known that the inspiral portion of the waveform corresponds to two distinct horizons orbiting each other and that the merger and ringdown signals correspond to the final horizon being formed and settling down to equilibrium. However, we still lack a detailed understanding of the relation between the horizon geometry in these three regimes and the observed waveform. Here we show that the well-known inspiral chirp waveform has a clear counterpart on black hole horizons, namely, the shear of the outgoing null rays at the horizon. We demonstrate that the shear behaves very much like a compact binary coalescence waveform with increasing frequency and amplitude. Furthermore, the parameters of the system estimated from the horizon agree with those estimated from the waveform. This implies that even though black hole horizons are causally disconnected from us, assuming general relativity to be true, we can potentially infer some of their detailed properties from gravitational wave observations.

Do preoperative glycosylated hemoglobin (HbA1C) and random blood glucose levels predict wound healing complications following exodontia in type 2 diabetes mellitus patients?-a prospective observational study

BACKGROUND

Many dental surgeons consider a type 2 diabetic patient to be at higher risk for wound healing complications following exodontia. Random blood glucose (RBG) and glycosylated hemoglobin (HbA1C) values help the surgeon determine the glycemic control and assess if the patient can undergo the surgical procedure.

OBJECTIVES

The purpose of this study was to analyze if preoperative HbA1C and RBG testing could predict the risk of wound healing and infectious complications in type 2 DM patients undergoing exodontia in an office setting.

METHODS

This prospective observational study included 133 type 2 diabetic patients and age- and gender-matched non-diabetic patients undergoing exodontia. Preoperative HbA1C values and random blood glucose levels were obtained for patients in both groups. Wound healing and infectious complications and additional interventions performed were recorded.

RESULTS

Duration of diabetes ranged from 1 to 25 years. 80.5% of diabetics were treated with oral hypoglycemics. A vast majority of patients in both groups underwent extraction of only a single tooth. There was no significant difference in non-infectious complications between the two groups. The absolute risk of infectious complications in diabetics was 10.5% compared to a 6.8% risk among the control group. Age, RBG values, HbA1C, duration of DM, and number and nature of exodontia performed did not show any statistical significance.

CONCLUSION

This study observed a slight, but not statistically significant increase in the risk of infectious complications in type 2 DM patients undergoing exodontia. Surgical site infections were amenable to surgical drainage with or without oral antibiotics on an outpatient basis with favorable healing outcomes.

CLINICAL RELEVANCE

The RBG and HbA1C values were not significantly associated with risk of infectious complications. Resorting to prophylactic antibiotics and warning about possible adverse healing for routine exodontia in type 2 DM patients is unnecessary.

Retraction of Orbital Soft Tissue During Orbital Surgery: A Technical Note

Introduction

Orbital fractures may be either isolated or part of midface fractures. These injuries may cause disruption of the orbital walls and herniation or entrapment of orbital contents resulting in enophthalmos or diplopia.

Methods

Surgical exploration of the orbit is the definitive mode of management of such injuries. A common problem encountered during such exploration is the prolapse of orbital soft tissues which hamper the visualization of the defects.

Conclusion

Here, we suggest an adjunct to the orbital retractors in control prolapsing soft tissues.

Interior of a Binary Black Hole Merger

We find strong numerical evidence for a new phenomenon in a binary black hole spacetime, namely, the merger of marginally outer trapped surfaces (MOTSs). By simulating the head-on collision of two nonspinning unequal mass black holes, we observe that the MOTS associated with the final black hole merges with the two initially disjoint surfaces corresponding to the two initial black holes. This yields a connected sequence of MOTSs interpolating between the initial and final state all the way through the nonlinear binary black hole merger process. In addition, we show the existence of a MOTS with self-intersections formed immediately after the merger. This scenario now allows us to track physical quantities (such as mass, angular momentum, higher multipoles, and fluxes) across the merger, which can be potentially compared with the gravitational wave signal in the wave zone, and with observations by gravitational wave detectors. This also suggests a possibility of proving the Penrose inequality mathematically for generic astrophysical binary back hole configurations.

Comparative Evaluation of IV Paracetamol Versus IV Dexmedetomidine in Inpatient Oral and Maxillofacial Surgery: A Double-Blinded Randomized Controlled Study

Purpose

Reconstructive surgeries following fractures in the maxillofacial region often involve considerable bone manipulation, and paracetamol is a commonly used analgesic medication in both intraoperative and postoperative periods. Dexmedetomidine, an alpha-2 adrenoceptor agonist, has both sedative and analgesic properties with minimal cardiorespiratory effects and has been used primarily for its sedative properties in oral and maxillofacial surgery.

Aims and Objectives

To compare the intraoperative analgesic requirements among patients undergoing oral and maxillofacial surgery who receive IV paracetamol versus IV dexmedetomidine. The time to requirement for the first postoperative analgesic dose and safety and adverse events of both medications were also assessed.

Patients and Methods

In total, 64 patients needing primary reconstructive surgery for facial fractures were recruited and divided into two groups for this double-blinded study. Patients were randomized to receive a preinduction dose of either IV paracetamol 1 g (Group P) or IV dexmedetomidine 1 µg/kg (Group D). Sedation scores (Ramsay sedation scale), maximal interincisal distance and pain scores at maximal mouth opening (visual analogue scale) were assessed in both groups just prior to and after the administration of the study drugs. After induction, Group P and Group D received a maintenance dose of normal saline and dexmedetomidine (0.5 µg/kg/h) during the intraoperative period, respectively. Standard noninvasive cardiorespiratory monitoring was done for the entire duration of surgery. Following extubation, postoperative pain scores and the time to request for first analgesic dose in either group were recorded.

Results

The time taken to perform the surgery was comparable in both groups. There was a significant difference between the groups in visual analogue scores and interincisal distance after the bolus dose (p < 0.05). Systolic and diastolic blood pressure was significantly lower in Group D at around 150 and 175 min of surgery. While the intraoperative fentanyl consumption was comparable in both groups, the time to request for the first analgesic dose in the postoperative period was significantly delayed in Group P (p < 0.05). No adverse cardiopulmonary events were observed in either group.

Conclusion

The intraoperative anesthetic and analgesic requirements and hemodynamic stability were comparable in IV paracetamol and dexmedetomidine groups. Dexmedetomidine did not confer any enhanced analgesia effect in the postoperative period. More research examining the role of dexmedetomidine for longer duration inpatient oral and maxillofacial surgery is needed.

Clinical Trial Number

http://ClinicalTrials.gov (No. CTRI/2017/08/009468).

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.

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.

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.

Efficacy of Neurectomy of Peripheral Branches of the Trigeminal Nerve in Trigeminal Neuralgia: A Critical Review of the Literature

Introduction

Of the many chronic painful conditions, trigeminal neuralgia (TN) affecting the orofacial region needs the particular attention of physicians and surgeons, especially those specialising in the maxillofacial region. Treatment protocols for the management of classic TN include pharmacology and surgical intervention. Oral and maxillofacial surgeons have traditionally employed the peripheral neurectomy in the surgical management of TN. This review aims to evaluate the efficacy of peripheral neurectomy in the management of TN with regard to (a) the relief of symptoms in comparison with standard neurosurgical procedures and (b) the duration of pain relief and complications observed compared to standard neurosurgical procedures.

Methods

The review of the literature was done according to PRISMA guidelines and included randomised controlled trials, reviews and prospective clinical studies involving surgical procedures for the management of TN. The primary outcomes evaluated were (a) initial relief of pain, (b) duration of relief of pain, (c) complications observed with ablative procedures and (d) recurrence of symptoms. A total of 43 studies fulfilled the inclusion criteria.

Results

In a total of 7913 patients from the 43 studies, central procedures were found to have best results for both quality and duration of pain relief. Percutaneous and peripheral procedures were associated with increased recurrence rates. The consolidated rates of complication for peripheral, percutaneous and central procedures were 39.46, 65.42 and 10.41%, respectively. The use of peripheral neurectomy alone in the management of classic TN was observed in 10 studies.

Conclusion

Peripheral neurectomy in TN is associated with lesser quality of pain relief in comparison with central neurosurgical procedures. It also provides only short- to medium-term pain relief. Most studies with the use of peripheral neurectomy involved only a small group of patients with short follow-up periods. Oral and maxillofacial surgeons must not consider the peripheral neurectomy as the first surgical option in the management of classic TN. Long-term results can be achieved better with appropriate central neurosurgical procedures and pharmacotherapy.

GW170817: Implications for the Stochastic Gravitational-Wave Background from Compact Binary Coalescences

The LIGO Scientific and Virgo Collaborations have announced the event GW170817, the first detection of gravitational waves from the coalescence of two neutron stars. The merger rate of binary neutron stars estimated from this event suggests that distant, unresolvable binary neutron stars create a significant astrophysical stochastic gravitational-wave background. The binary neutron star component will add to the contribution from binary black holes, increasing the amplitude of the total astrophysical background relative to previous expectations. In the Advanced LIGO-Virgo frequency band most sensitive to stochastic backgrounds (near 25 Hz), we predict a total astrophysical background with amplitude Ω_{GW}(f=25  Hz)=1.8_{-1.3}^{+2.7}×10^{-9} with 90% confidence, compared with Ω_{GW}(f=25  Hz)=1.1_{-0.7}^{+1.2}×10^{-9} from binary black holes alone. Assuming the most probable rate for compact binary mergers, we find that the total background may be detectable with a signal-to-noise-ratio of 3 after 40 months of total observation time, based on the expected timeline for Advanced LIGO and Virgo to reach their design sensitivity.

First Search for Nontensorial Gravitational Waves from Known Pulsars

We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper limits for scalar and vector strains, finding values comparable in magnitude to previously published limits for tensor strain. Our results may be translated into constraints on specific alternative theories of gravity.

Copper antimony sulfide thin films for visible to near infrared photodetector applications

Ternary chalcostibite copper antimony sulfide (CuSbS₂) is an emerging semiconductor material having applications in photovoltaics, energy storage and optoelectronics due to its high absorption coefficient, suitable bandgap, and it consists of non-toxic and earth abundant elements. CuSbS₂ thin films are prepared by combining chemical bath deposition (antimony sulfide (Sb₂S₃)) and thermal evaporation (copper (Cu)) followed by a heat treatment and their application as visible to near infrared photodetectors is reported. Crystalline structure, elemental composition, chemical state, morphology and optoelectronic properties of the films were characterized by various techniques. The effect of three different Cu thicknesses (CAS 20, CAS 30 and CAS 40 nm) on the photodetection properties are evaluated under illumination using light emitting diodes (LEDs) and a laser. The photodetectors fabricated are successfully tested under different wavelengths, power densities and applied voltage and their photoresponse cyclic stability for each wavelength of illumination was recorded. From the sensitivity calculations, the sample with 20 nm Cu thickness (CAS 20) showed higher detection sensitivity for visible to near infrared wavelengths. Better responsivity results were obtained for CAS 40 because of its improved crystallinity and phase purity. Photodetector properties such as sensitivity and responsivity are evaluated for all the samples. These results are beneficial for cost effective and environment friendly photodetectors and optoelectronic devices based on CuSbS₂ thin films.

Copper antimony sulfide (CuSbS₂) thin films for visible to near infrared photodetection

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and [Formula: see text] credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5-[Formula: see text] requires at least three detectors of sensitivity within a factor of [Formula: see text] of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral

On August 17, 2017 at 12∶41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio of 32.4 and a false-alarm-rate estimate of less than one per 8.0×10^{4}  years. We infer the component masses of the binary to be between 0.86 and 2.26  M_{⊙}, in agreement with masses of known neutron stars. Restricting the component spins to the range inferred in binary neutron stars, we find the component masses to be in the range 1.17-1.60  M_{⊙}, with the total mass of the system 2.74_{-0.01}^{+0.04}M_{⊙}. The source was localized within a sky region of 28  deg^{2} (90% probability) and had a luminosity distance of 40_{-14}^{+8}  Mpc, the closest and most precisely localized gravitational-wave signal yet. The association with the γ-ray burst GRB 170817A, detected by Fermi-GBM 1.7 s after the coalescence, corroborates the hypothesis of a neutron star merger and provides the first direct evidence of a link between these mergers and short γ-ray bursts. Subsequent identification of transient counterparts across the electromagnetic spectrum in the same location further supports the interpretation of this event as a neutron star merger. This unprecedented joint gravitational and electromagnetic observation provides insight into astrophysics, dense matter, gravitation, and cosmology.

GW170814: A Three-Detector Observation of Gravitational Waves from a Binary Black Hole Coalescence

On August 14, 2017 at 10∶30:43 UTC, the Advanced Virgo detector and the two Advanced LIGO detectors coherently observed a transient gravitational-wave signal produced by the coalescence of two stellar mass black holes, with a false-alarm rate of ≲1 in 27 000 years. The signal was observed with a three-detector network matched-filter signal-to-noise ratio of 18. The inferred masses of the initial black holes are 30.5_{-3.0}^{+5.7}M_{⊙} and 25.3_{-4.2}^{+2.8}M_{⊙} (at the 90% credible level). The luminosity distance of the source is 540_{-210}^{+130}  Mpc, corresponding to a redshift of z=0.11_{-0.04}^{+0.03}. A network of three detectors improves the sky localization of the source, reducing the area of the 90% credible region from 1160   deg^{2} using only the two LIGO detectors to 60  deg^{2} using all three detectors. For the first time, we can test the nature of gravitational-wave polarizations from the antenna response of the LIGO-Virgo network, thus enabling a new class of phenomenological tests of gravity.

GW170104: Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2

We describe the observation of GW170104, a gravitational-wave signal produced by the coalescence of a pair of stellar-mass black holes. The signal was measured on January 4, 2017 at 10∶11:58.6 UTC by the twin advanced detectors of the Laser Interferometer Gravitational-Wave Observatory during their second observing run, with a network signal-to-noise ratio of 13 and a false alarm rate less than 1 in 70 000 years. The inferred component black hole masses are 31.2_{-6.0}^{+8.4}M_{⊙} and 19.4_{-5.9}^{+5.3}M_{⊙} (at the 90% credible level). The black hole spins are best constrained through measurement of the effective inspiral spin parameter, a mass-weighted combination of the spin components perpendicular to the orbital plane, χ_{eff}=-0.12_{-0.30}^{+0.21}. This result implies that spin configurations with both component spins positively aligned with the orbital angular momentum are disfavored. The source luminosity distance is 880_{-390}^{+450}  Mpc corresponding to a redshift of z=0.18_{-0.07}^{+0.08}. We constrain the magnitude of modifications to the gravitational-wave dispersion relation and perform null tests of general relativity. Assuming that gravitons are dispersed in vacuum like massive particles, we bound the graviton mass to m_{g}≤7.7×10^{-23}  eV/c^{2}. In all cases, we find that GW170104 is consistent with general relativity.

Improving the Quality of Oral and Maxillofacial Surgical Notes in an Indian Public Sector Hospital in Accordance with the Royal College of Surgeons Guidelines: A Completed Audit Loop Study

AIM

Proper and adequate documentation in operation notes is a basic tool of clinical practice with medical and legal implications. An audit was done to ascertain if oral and maxillofacial surgery operative notes in an Indian public sector hospital adhered to the guidelines published by the Royal College of Surgeons England.

METHODS

Fifty randomly selected operative notes were evaluated against the guidelines by RCS England with regards to the essential generic components of an operation note. Additional criteria relevant to oral and Maxillofacial Surgery were also evaluated. Changes were introduced in the form of Oral and Maxillofacial Surgery specific consent forms, diagram sheets and a computerized operation note proforma containing all essential and additional criteria along with prefilled template of operative findings. Re-audit of 50 randomly selected operation notes was performed after a 6 month period.

RESULTS

In the 1st audit cycle, excellent documentation ranging from 94 to 100 % was seen in 9 essential criteria. Unsatisfactory documentation was observed in criteria like assistant name, date of surgery. Most consent forms contained abbreviations and some did not provide all details. Additional criteria specific to Oral and Maxillofacial Surgery scored poorly. In the 2nd Audit for loop completion, excellent documentation was seen in almost all essential and additional criteria. Mean percentage of data point inclusion improved from 84.6 to 98.4 % (0.001< P value <0.005). The use of abbreviations was seen in only 6 notes.

CONCLUSION

Regular audits are now considered a mandatory quality improvement process that seeks to improve patient care and outcomes. To the best of our knowledge, this is the first completed audit on operation notes documentation in Oral and Maxillofacial Surgery from India. The introduction of a computerized operation note proforma showed excellent improvement in operation note documentation. Surgeons can follow the RCS guidelines to ensure standardization of operation notes.

Brain dynamics based automated epileptic seizure detection

We developed and tested a seizure detection algorithm based on two measures of nonlinear and linear dynamics, that is, the adaptive short-term maximum Lyapunov exponent (ASTLmax) and the adaptive Teager energy (ATE). The algorithm was tested on long-term (0.5-11.7 days) continuous EEG recordings from five patients (3 with intracranial and 2 with scalp EEG) with a total of 56 seizures, producing a mean sensitivity of 91% and mean specificity of 0.14 false positives per hour. The developed seizure detection algorithm is data-adaptive, training-free, and patient-independent.

Automated MRI Volumetric Analysis in Patients with Rasmussen Syndrome

BACKGROUND AND PURPOSE

Rasmussen syndrome, also known as Rasmussen encephalitis, is typically associated with volume loss of the affected hemisphere of the brain. Our aim was to apply automated quantitative volumetric MR imaging analyses to patients diagnosed with Rasmussen encephalitis, to determine the predictive value of lobar volumetric measures and to assess regional atrophy differences as well as monitor disease progression by using these measures.

MATERIALS AND METHODS

Nineteen patients (42 scans) with diagnosed Rasmussen encephalitis were studied. We used 2 control groups: one with 42 age- and sex-matched healthy subjects and the other with 42 epileptic patients without Rasmussen encephalitis with the same disease duration as patients with Rasmussen encephalitis. Volumetric analysis was performed on T1-weighted images by using BrainSuite. Ratios of volumes from the affected hemisphere divided by those from the unaffected hemisphere were used as input to a logistic regression classifier, which was trained to discriminate patients from controls. Using the classifier, we compared the predictive accuracy of all the volumetric measures. These ratios were used to further assess regional atrophy differences and correlate with epilepsy duration.

RESULTS

Interhemispheric and frontal lobe ratios had the best prediction accuracy for separating patients with Rasmussen encephalitis from healthy controls and patient controls without Rasmussen encephalitis. The insula showed significantly more atrophy compared with all the other cortical regions. Patients with longitudinal scans showed progressive volume loss in the affected hemisphere. Atrophy of the frontal lobe and insula correlated significantly with epilepsy duration.

CONCLUSIONS

Automated quantitative volumetric analysis provides accurate separation of patients with Rasmussen encephalitis from healthy controls and epileptic patients without Rasmussen encephalitis, and thus may assist the diagnosis of Rasmussen encephalitis. Volumetric analysis could also be included as part of follow-up for patients with Rasmussen encephalitis to assess disease progression.

Dynamic and Stable Cohesins Regulate Synaptonemal Complex Assembly and Chromosome Segregation

Assembly of the synaptonemal complex (SC) in Drosophila depends on two independent pathways defined by the chromosome axis proteins C(2)M and ORD. Because C(2)M encodes a Kleisin-like protein and ORD is required for sister-chromatid cohesion, we tested the hypothesis that these two SC assembly pathways depend on two cohesin complexes. Through single- and double-mutant analysis to study the mitotic cohesion proteins Stromalin (SA) and Nipped-B (SCC2) in meiosis, we provide evidence that there are at least two meiosis-specific cohesin complexes. One complex depends on C(2)M, SA, and Nipped-B. Despite the presence of mitotic cohesins SA and Nipped-B, this pathway has only a minor role in meiotic sister-centromere cohesion and is primarily required for homolog interactions. C(2)M is continuously incorporated into pachytene chromosomes even though SC assembly is complete. In contrast, the second complex, which depends on meiosis-specific proteins SOLO, SUNN, and ORD is required for sister-chromatid cohesion, localizes to the centromeres and is not incorporated during prophase. Our results show that the two cohesin complexes have unique functions and are regulated differently. Multiple cohesin complexes may provide the diversity of activities required by the meiotic cell. For example, a dynamic complex may allow the chromosomes to regulate meiotic recombination, and a stable complex may be required for sister-chromatid cohesion.

Characterization of transient noise in Advanced LIGO relevant to gravitational wave signal GW150914

On September 14, 2015, a gravitational wave signal from a coalescing black hole binary system was observed by the Advanced LIGO detectors. This paper describes the transient noise backgrounds used to determine the significance of the event (designated GW150914) and presents the results of investigations into potential correlated or uncorrelated sources of transient noise in the detectors around the time of the event. The detectors were operating nominally at the time of GW150914. We have ruled out environmental influences and non-Gaussian instrument noise at either LIGO detector as the cause of the observed gravitational wave signal.

GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence

We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5σ. The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 Hz, and reached a peak gravitational strain of 3.4_{-0.9}^{+0.7}×10^{-22}. The inferred source-frame initial black hole masses are 14.2_{-3.7}^{+8.3}M_{⊙} and 7.5_{-2.3}^{+2.3}M_{⊙}, and the final black hole mass is 20.8_{-1.7}^{+6.1}M_{⊙}. We find that at least one of the component black holes has spin greater than 0.2. This source is located at a luminosity distance of 440_{-190}^{+180}  Mpc corresponding to a redshift of 0.09_{-0.04}^{+0.03}. All uncertainties define a 90% credible interval. This second gravitational-wave observation provides improved constraints on stellar populations and on deviations from general relativity.

Properties of the Binary Black Hole Merger GW150914

On September 14, 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected a gravitational-wave transient (GW150914); we characterize the properties of the source and its parameters. The data around the time of the event were analyzed coherently across the LIGO network using a suite of accurate waveform models that describe gravitational waves from a compact binary system in general relativity. GW150914 was produced by a nearly equal mass binary black hole of masses 36_{-4}^{+5}M_{⊙} and 29_{-4}^{+4}M_{⊙}; for each parameter we report the median value and the range of the 90% credible interval. The dimensionless spin magnitude of the more massive black hole is bound to be <0.7 (at 90% probability). The luminosity distance to the source is 410_{-180}^{+160}  Mpc, corresponding to a redshift 0.09_{-0.04}^{+0.03} assuming standard cosmology. The source location is constrained to an annulus section of 610  deg^{2}, primarily in the southern hemisphere. The binary merges into a black hole of mass 62_{-4}^{+4}M_{⊙} and spin 0.67_{-0.07}^{+0.05}. This black hole is significantly more massive than any other inferred from electromagnetic observations in the stellar-mass regime.

GW150914: First results from the search for binary black hole coalescence with Advanced LIGO

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) simultaneously observed the binary black hole merger GW150914. We report the results of a matched-filter search using relativistic models of compact-object binaries that recovered GW150914 as the most significant event during the coincident observations between the two LIGO detectors from September 12 to October 20, 2015. GW150914 was observed with a matched filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203000 years, equivalent to a significance greater than 5.1 σ.

GW150914: First results from the search for binary black hole coalescence with Advanced LIGO

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) simultaneously observed the binary black hole merger GW150914. We report the results of a matched-filter search using relativistic models of compact-object binaries that recovered GW150914 as the most significant event during the coincident observations between the two LIGO detectors from September 12 to October 20, 2015. GW150914 was observed with a matched filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203000 years, equivalent to a significance greater than 5.1 σ.

Tests of General Relativity with GW150914

The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following the peak of GW150914 are consistent with the least-damped quasinormal mode inferred from the mass and spin of the remnant black hole. By using waveform models that allow for parametrized general-relativity violations during the inspiral and merger phases, we perform quantitative tests on the gravitational-wave phase in the dynamical regime and we determine the first empirical bounds on several high-order post-Newtonian coefficients. We constrain the graviton Compton wavelength, assuming that gravitons are dispersed in vacuum in the same way as particles with mass, obtaining a 90%-confidence lower bound of 10^{13}  km. In conclusion, within our statistical uncertainties, we find no evidence for violations of general relativity in the genuinely strong-field regime of gravity.

Observation of Gravitational Waves from a Binary Black Hole Merger

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410(-180)(+160)  Mpc corresponding to a redshift z=0.09(-0.04)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M⊙ and 29(-4)(+4)M⊙, and the final black hole mass is 62(-4)(+4)M⊙, with 3.0(-0.5)(+0.5)M⊙c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

Prospects for Observing and Localizing Gravitational-Wave Transients with Advanced LIGO and Advanced Virgo

We present a possible observing scenario for the Advanced LIGO and Advanced Virgo gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We determine the expected sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron-star systems, which are considered the most promising for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and 90% credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5 deg2 to 20 deg2 will require at least three detectors of sensitivity within a factor of ∼ 2 of each other and with a broad frequency bandwidth. Should the third LIGO detector be relocated to India as expected, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

Major Histocompatibility Complex Class II Dextramers: New Tools for the Detection of antigen-Specific, CD4 T Cells in Basic and Clinical Research

The advent of major histocompatibility complex (MHC) tetramer technology has been a major contribution to T cell immunology, because tetramer reagents permit detection of antigen-specific T cells at the single-cell level in heterogeneous populations by flow cytometry. However, unlike MHC class I tetramers, the utility of MHC class II tetramers has been less frequently reported. MHC class II tetramers can be used successfully to enumerate the frequencies of antigen-specific CD4 T cells in cells activated in vitro, but their use for ex vivo analyses continues to be a problem, due in part to their activation dependency for binding with T cells. To circumvent this problem, we recently reported the creation of a new generation of reagents called MHC class II dextramers, which were found to be superior to their counterparts. In this review, we discuss the utility of class II dextramers vis-a-vis tetramers, with respect to their specificity and sensitivity, including potential applications and limitations.

Sisters unbound is required for meiotic centromeric cohesion in Drosophila melanogaster

Regular meiotic chromosome segregation requires sister centromeres to mono-orient (orient to the same pole) during the first meiotic division (meiosis I) when homologous chromosomes segregate, and to bi-orient (orient to opposite poles) during the second meiotic division (meiosis II) when sister chromatids segregate. Both orientation patterns require cohesion between sister centromeres, which is established during meiotic DNA replication and persists until anaphase of meiosis II. Meiotic cohesion is mediated by a conserved four-protein complex called cohesin that includes two structural maintenance of chromosomes (SMC) subunits (SMC1 and SMC3) and two non-SMC subunits. In Drosophila melanogaster, however, the meiotic cohesion apparatus has not been fully characterized and the non-SMC subunits have not been identified. We have identified a novel Drosophila gene called sisters unbound (sunn), which is required for stable sister chromatid cohesion throughout meiosis. sunn mutations disrupt centromere cohesion during prophase I and cause high frequencies of non-disjunction (NDJ) at both meiotic divisions in both sexes. SUNN co-localizes at centromeres with the cohesion proteins SMC1 and SOLO in both sexes and is necessary for the recruitment of both proteins to centromeres. Although SUNN lacks sequence homology to cohesins, bioinformatic analysis indicates that SUNN may be a structural homolog of the non-SMC cohesin subunit stromalin (SA), suggesting that SUNN may serve as a meiosis-specific cohesin subunit. In conclusion, our data show that SUNN is an essential meiosis-specific Drosophila cohesion protein.