The Role of Postoperative Radiotherapy in T4 Rectal Cancer with Synchronous Distant Metastasis

PURPOSE/OBJECTIVE(S)

Studieson the role of surgery and local treatment in M1 rectal cancer have been actively studied recently. However, there is still controversy because no significant results have been reported for local control. The purpose of this study was to analyze the local control rates of postoperative radiotherapy for tumor stage T4 in M1 rectal cancer.

MATERIALS/METHODS

We investigated local recurrence after surgery for M1 rectal cancer that was operated at Seoul St. Mary's Hospital between 1995 and 2021. Locoregional recurrence rates were compared in patients who received postoperative pelvic radiotherapy and those who did not. In addition, an analytical comparison was performed only for patients with T4 rectal cancer. Statistical analysis was performed using the log rank test, and a p-value of less than 0.05 was considered significant.

RESULTS

During the investigation period, a total of 206 patients underwent surgery for M1 rectal cancer. There were 55 patients with T4 tumor stage. Of the 55 patients, 11 patients received radiotherapy after surgery, and 44 patients received systemic treatment such as chemotherapy after surgery without radiotherapy. During a median follow-up of 22 months, locoregional recurrence occurred in 1 (RT group) and 25 (no RT group) patients, respectively. Log-rank analysis of locoregional recurrence showed a significant difference between the two groups (p- value = 0.008). Death occurred in 10 (RT group) and 38 (no RT group) patients, respectively. The 2-year locoregional recurrence free-survival rates were 45.5% and 53.0%, respectively, and there was no significant difference between the two groups in the log-rank analysis.

CONCLUSION

Pelvic radiotherapy could be expected to improve locoregional recurrence in stage T4 of rectal cancer with synchronous distant metastasis. It would be warranted to prove this in a large-scale prospective study.

Evaluation of Usefulness of Yeast-Based Biological Phantom and Preliminary Study for Verification of Hypoxic Effect of Flash Radiotherapy

PURPOSE/OBJECTIVE(S)

As a basic hypothesis for the effectiveness of flash radiation therapy, the effect of preserving normal tissue during flash radiation is due to the instantaneous chemical depletion of oxygen. A yeast-based biological phantom was created to verify the hypoxic effect of flash radiation therapy. A study to upgrade the previously developed X-Band LINAC to a flash irradiation mode is in progress, and a preceding study is conducted to evaluate the usefulness of a yeast-based biological phantom manufactured by analyzing the change in oxygen by irradiating a high dose in a general radiation therapy device.

MATERIALS/METHODS

Freeze-dried yeast sample (Saccharomyces cerevisiae, S288C) is activated and sub-cultured. For mass production of yeast samples, yeast culture medium is prepared by adding yeast colonies to the ypd medium. This study was conducted to verify the hypoxic effect among the biological mechanisms that occur during flash radiation therapy at the basic stage, and the oxygen concentration change during general radiation irradiation was measured in real time using a DO (Dissolved oxygen) meter and fiber optic sensor designed to do that. To prevent scatter, which is a concern during flash irradiation, the fiber form was used, and precise experiments are possible as a non-invasive oxygen concentration measurement method. Based on 10MV of general radiation therapy device, high-dose radiation of 500-10,000 cGy is irradiated to measure real-time oxygen concentration change.

RESULTS

As a result of irradiation with high-dose (500-10,000 cGy) radiation of general LINAC, it was confirmed that the oxygen concentration of the yeast culture medium decreased by 5.7-63.2%, and the usefulness of the biological phantom fabricated based on the yeast culture medium was evaluated.

CONCLUSION

Prior to the analysis of oxygen concentration change in yeast cells during X-Band LINAC flash irradiation, a preliminary study was conducted at a high dose in a general LINAC to obtain a significant result of oxygen concentration change and confirm the usefulness of the yeast-based biological phantom. Prior research was conducted and verified as a general irradiation experiment using a yeast-based biological phantom manufactured based on a DO meter and a fiber optic oxygen sensor. After irradiation with high-dose radiation, the oxygen concentration of the yeast culture medium was measured 5 times, and it was confirmed that there was a change in oxygen concentration of 5.7-63.2%, verifying the usefulness and stability of the biological phantom. The usefulness of the yeast-based biological phantom for high doses was confirmed, and it is expected that the usefulness of the biological phantom for flash radiation can be verified by additionally measuring the change in oxygen concentration of the biological phantom according to the high dose rate in the future.

An evolutionary epigenetic clock in plants

Molecular clocks are the basis for dating the divergence between lineages over macroevolutionary timescales (~105 to 108 years). However, classical DNA-based clocks tick too slowly to inform us about the recent past. Here, we demonstrate that stochastic DNA methylation changes at a subset of cytosines in plant genomes display a clocklike behavior. This "epimutation clock" is orders of magnitude faster than DNA-based clocks and enables phylogenetic explorations on a scale of years to centuries. We show experimentally that epimutation clocks recapitulate known topologies and branching times of intraspecies phylogenetic trees in the self-fertilizing plant Arabidopsis thaliana and the clonal seagrass Zostera marina, which represent two major modes of plant reproduction. This discovery will open new possibilities for high-resolution temporal studies of plant biodiversity.

Water in the terrestrial planet-forming zone of the PDS 70 disk

Terrestrial and sub-Neptune planets are expected to form in the inner (less than 10 AU) regions of protoplanetary disks1. Water plays a key role in their formation2-4, although it is yet unclear whether water molecules are formed in situ or transported from the outer disk5,6. So far Spitzer Space Telescope observations have only provided water luminosity upper limits for dust-depleted inner disks7, similar to PDS 70, the first system with direct confirmation of protoplanet presence8,9. Here we report JWST observations of PDS 70, a benchmark target to search for water in a disk hosting a large (approximately 54 AU) planet-carved gap separating an inner and outer disk10,11. Our findings show water in the inner disk of PDS 70. This implies that potential terrestrial planets forming therein have access to a water reservoir. The column densities of water vapour suggest in-situ formation via a reaction sequence involving O, H2 and/or OH, and survival through water self-shielding5. This is also supported by the presence of CO2 emission, another molecule sensitive to ultraviolet photodissociation. Dust shielding, and replenishment of both gas and small dust from the outer disk, may also play a role in sustaining the water reservoir12. Our observations also reveal a strong variability of the mid-infrared spectral energy distribution, pointing to a change of inner disk geometry.

An evolutionary epigenetic clock in plants

Molecular clocks are the basis for dating the divergence between lineages over macro-evolutionary timescales (~10 5 -10 8 years). However, classical DNA-based clocks tick too slowly to inform us about the recent past. Here, we demonstrate that stochastic DNA methylation changes at a subset of cytosines in plant genomes possess a clock-like behavior. This 'epimutation-clock' is orders of magnitude faster than DNA-based clocks and enables phylogenetic explorations on a scale of years to centuries. We show experimentally that epimutation-clocks recapitulate known topologies and branching times of intra-species phylogenetic trees in the selfing plant A. thaliana and the clonal seagrass Z. marina , which represent two major modes of plant reproduction. This discovery will open new possibilities for high-resolution temporal studies of plant biodiversity.

Oral Candida Predicts Streptococcus mutans Emergence in Underserved US Infants

Despite the cariogenic role of Candida suggested from recent studies, oral Candida acquisition in children at high risk for early childhood caries (ECC) and its association with cariogenic bacteria Streptococcus mutans remain unclear. Although ECC disproportionately afflicts socioeconomically disadvantaged and racial-minority children, microbiological studies focusing on the underserved group are scarce. Our prospective cohort study examined the oral colonization of Candida and S. mutans among 101 infants exclusively from a low-income and racial-minority background in the first year of life. The Cox hazard proportional model was fitted to assess factors associated with the time to event of the emergence of oral Candida and S. mutans. Oral Candida colonization started as early as 1 wk among 13% of infants, increased to 40% by 2 mo, escalated to 48% by 6 mo, and remained the same level until 12 mo. S. mutans in saliva was detected among 20% infants by 12 mo. The emergence of S. mutans by year 1 was 3.5 times higher (hazard ratio [HR], 3.5; confidence interval [CI], 1.1-11.3) in infants who had early colonization of oral Candida compared to those who were free of oral Candida (P = 0.04) and 3 times higher (HR, 3.0; CI, 1.3-6.9) among infants whose mother had more than 3 decayed teeth (P = 0.01), even after adjusting demographics, feeding, mother's education, and employment status. Infants' salivary S. mutans abundance was positively correlated with infants' Candida albicans (P < 0.01) and Candida krusei levels (P < 0.05). Infants' oral colonization of C. albicans was positively associated with mother's oral C. albicans carriage and education (P < 0.01) but negatively associated with mother's employment status (P = 0.01). Future studies are warranted to examine whether oral Candida modulates the oral bacterial community as a whole to become cariogenic during the onset and progression of ECC, which could lead to developing novel ECC predictive and preventive strategies from a fungal perspective.

Optimal application of compressive palatal stents following mesiodens removal in pediatric patients: A Randomized Controlled Trial

Background

There is no scientific evidence supporting the choice of a palatal stent in patients who underwent removal of an impacted supernumerary tooth. We aimed to investigate the effects of palatal stents in patients who underwent supernumerary tooth removal through a palatal approach and to suggest the optimal stent thickness and material.

Material and Methods

We recruited 144 patients who underwent extraction of a supernumerary tooth between the maxillary anterior teeth. Subjects were assigned to a control group (CG) or one of four compressive palatal stent groups (CPSGs) classified by the thickness and material of the thermoplastic acrylic stent used. Palatal gingival swelling and objective indices (healing, oral hygiene, gingival, and plaque) were evaluated before surgery and on postoperative days (PODs) 3, 7, and 14; pain/discomfort and the Child Oral Health Impact Profile (COHIP) were assessed as subjective indices of the effects of the stent.

Results

The CPSGs showed faster healing than did the CG on PODs 7 (P<0.001) and 14 (P=0.043); swelling was measured by 1.64±0.88 mm and 4.52±0.39 mm, respectively. Although swelling was least in the 4-mm hard group (0.92±0.33 mm), the difference compared with that in the 2-mm hard group (1.01±0.18 mm) was not significant (P=0.077). The CPSGs showed better COHIP (P<0.001-0.036) and pain scores (P<0.001) than did the CG on PODs 1-3.

Conclusions

Compressive palatal stents reduce discomfort by decreasing pain and alleviating swelling. Although a stent is effective regardless of its thickness and material, 2-mm hard stents maximized such positive effects with minimal discomfort.

Key words:Supernumerary tooth, tooth Extraction, postoperative care, oral Health, pediatric dentistry.

Altered distributions in circulating follicular helper and follicular regulatory T cells accountable for imbalanced cytokine production in multiple sclerosis

Follicular T helper (Tfh) and regulatory (Tfr) cells are distinct subsets of CD4+ T lymphocytes, regulating humoral immune responses in the germinal center. It is widely accepted that dysregulated Tfh and Tfr cells are associated with autoimmunity. In this study, we evaluated the frequencies of circulating chemokine receptor (CXCR)5+ programmed cell death 1 (PD-1+ ) Tfh (cTfh) and CXCR5+ PD-1+ forkhead box protein 3 (FoxP3+ ) CD25+ Tfr (cTfr) cells, and their corresponding cytokines from the peripheral blood mononuclear cells of 28 patients with relapsing-remitting multiple sclerosis (MS) and 16 age- and sex-matched healthy controls (HC). Subsets of cTfh cells by Th1- and Th17-related surface markers (CXCR3 and CCR6) were also evaluated. We found that the frequency of cTfh cells was significantly higher in MS patients compared to that of HC. Conversely, the frequency of cTfr cells was lower in MS patients than that of HC. Interleukin (IL)-21-producing cTfh cells were significantly increased in MS patients, while IL-10-secreting cTfr cells were lower in MS patients compared to levels in HC. Among cTfh cells, cTfh17.1 cells were the major subtypes that were significantly increased in MS patients compared to HC, with the frequency of IL-21-secreting cells being the highest. These results suggest that an imbalanced distribution of cTfh and cTfr exist in MS patients, which contributes to the reciprocally altered IL-21 and IL-10 production.

Inversion Recovery Ultrashort TE MR Imaging of Myelin is Significantly Correlated with Disability in Patients with Multiple Sclerosis

BACKGROUND AND PURPOSE

MR imaging has been widely used for the noninvasive evaluation of MS. Although clinical MR imaging sequences are highly effective in showing focal macroscopic tissue abnormalities in the brains of patients with MS, they are not specific to myelin and correlate poorly with disability. We investigated direct imaging of myelin using a 2D adiabatic inversion recovery ultrashort TE sequence to determine its value in assessing disability in MS.

MATERIALS AND METHODS

The 2D inversion recovery ultrashort TE sequence was evaluated in 14 healthy volunteers and 31 patients with MS. MPRAGE and T2-FLAIR images were acquired for comparison. Advanced Normalization Tools were used to correlate inversion recovery ultrashort TE, MPRAGE, and T2-FLAIR images with disability assessed by the Expanded Disability Status Scale.

RESULTS

Weak correlations were observed between normal-appearing white matter volume (R = -0.03, P = .88), lesion load (R = 0.22, P = .24), and age (R = 0.14, P = .44), and disability. The MPRAGE signal in normal-appearing white matter showed a weak correlation with age (R = -0.10, P = .49) and disability (R = -0.19, P = .31). The T2-FLAIR signal in normal-appearing white matter showed a weak correlation with age (R = 0.01, P = .93) and disability (R = 0.13, P = .49). The inversion recovery ultrashort TE signal was significantly negatively correlated with age (R = -0.38, P = .009) and disability (R = -0.44; P = .01).

CONCLUSIONS

Direct imaging of myelin correlates with disability in patients with MS better than indirect imaging of long-T2 water in WM using conventional clinical sequences.

0971 Mother’s Parenting Style As A Moderator In The Relationship Between Temperament And Sleep Problems In Children With Obesity

Introduction

Based on past studies, a child’s temperament and parenting style greatly affect a child’s sleep. However, there are limited studies that have investigated how parenting styles and a child’s temperament interact and affect the child’s sleep in obese children. Thus, this study investigated parenting styles as a moderator in the relationship between temperament and sleep in obese children.

Methods

Seventy-seven obese children (male=66.2%, average BMI = 27.35±2.78) participated in the study. The mean age of the participants was 10.82(± 1.00) years. The primary caregiver (mother) of the participants completed the Junior Temperament and Character Inventory (J-TCI), and Parents as Social Context Questionnaire (K-PSCQ), and Children’s Sleep Habits Questionnaire (CSHQ). Among the different subscales, only Novelty Seeking (NS) and Reward Dependence (RD) were used for analysis among Junior Temperament and Character Inventory (J-TCI) components.

Results

In this sample, 66 children (85.7%) reported significant levels of sleep problems based on the CSHQ. Novelty seeking (NS) and reward dependence (RD) significantly predicted sleep problems (B=-.771, p&lt;.05, B=-.683, p&lt;.01). Additionally, mother’s negative parenting style moderated the relationship between NS and the child’s sleep problem [B=.03, 95% CI=.007, .049] and the relationship between RD and the child’s sleep problem [B=.031, 95% CI=.013, .049]. The more negative mother’s parenting style, the higher the child’s NS or RD scores had a negative effect on sleep.

Conclusion

The results of this study show that obese children experience high levels of sleep disturbance. Additionally, the mother’s negative parenting style moderated the relationship between temperament and sleep problems in obese children. The results suggest that sleep interventions for obese children should include the mother, especially in children with high novelty seeking and reward dependence.

Support

This work was supported by Korea Centers for Disease Control and Prevention & Korea National Research Institute of Health (2019020660E-00)

Observation of two types of charge-density-wave orders in superconducting La2-xSrxCuO4

The discovery of charge- and spin-density-wave (CDW/SDW) orders in superconducting cuprates has altered our perspective on the nature of high-temperature superconductivity (SC). However, it has proven difficult to fully elucidate the relationship between the density wave orders and SC. Here, using resonant soft X-ray scattering, we study the archetypal cuprate La_2-xSr_xCuO₄ (LSCO) over a broad doping range. We reveal the existence of two types of CDW orders in LSCO, namely CDW stripe order and CDW short-range order (SRO). While the CDW-SRO is suppressed by SC, it is partially transformed into the CDW stripe order with developing SDW stripe order near the superconducting T_c. These findings indicate that the stripe orders and SC are inhomogeneously distributed in the superconducting CuO₂ planes of LSCO. This further suggests a new perspective on the putative pair-density-wave order that coexists with SC, SDW, and CDW orders.

To fully elucidate the relationship between density wave orders and superconductivity in high-T_c cuprates remains difficult. Here, the authors reveal two types of charge-density-wave orders and their intertwined relationship with spin-density-wave order and superconductivity in La_2-xSr_xCuO_4.

Erratum: Observation of D^{0} Meson Nuclear Modifications in Au+Au Collisions at sqrt[s_{NN}]=200 GeV [Phys. Rev. Lett. 113, 142301 (2014)]

This corrects the article DOI: 10.1103/PhysRevLett.113.142301.

Mutations in LZTR1 drive human disease by dysregulating RAS ubiquitination

The leucine zipper-like transcriptional regulator 1 (LZTR1) protein, an adaptor for cullin 3 (CUL3) ubiquitin ligase complex, is implicated in human disease, yet its mechanism of action remains unknown. We found that Lztr1 haploinsufficiency in mice recapitulates Noonan syndrome phenotypes, whereas LZTR1 loss in Schwann cells drives dedifferentiation and proliferation. By trapping LZTR1 complexes from intact mammalian cells, we identified the guanosine triphosphatase RAS as a substrate for the LZTR1-CUL3 complex. Ubiquitome analysis showed that loss of Lztr1 abrogated Ras ubiquitination at lysine-170. LZTR1-mediated ubiquitination inhibited RAS signaling by attenuating its association with the membrane. Disease-associated LZTR1 mutations disrupted either LZTR1-CUL3 complex formation or its interaction with RAS proteins. RAS regulation by LZTR1-mediated ubiquitination provides an explanation for the role of LZTR1 in human disease.

Correlates of toenail selenium and its cross-sectional association with metabolic syndrome

BACKGROUND

The present study aimed to identify independent correlates of toenail selenium levels and to examine the association between toenail selenium levels and metabolic syndrome in Korean adults.

METHODS

Cross-sectional analysis was conducted using baseline data from the Trace Element Study of Korean Adults in the Yeungnam area, an ongoing cohort study of Korean adults over the age of 35 years. The baseline survey consisted of questionnaires on demographics, lifestyle characteristics and medical information. Dietary information was obtained through a validated semi-quantitative food frequency questionnaire. Toenail selenium levels were quantified using neutron activation analysis. Biomarkers associated with metabolic syndrome were obtained from biennial medical check-ups.

RESULTS

In the multivariable-adjusted analyses, independent lifestyle and dietary correlates of higher selenium levels were alcohol drinking (4.62% higher than nondrinking) and egg intake (0.43% higher per weekly serving), whereas current smoking (5.42% lower than nonsmoking) and vegetable consumption (0.05% lower per weekly serving) were associated with lower toenail selenium levels. In the multivariable adjusted logistic regression, no significant association was observed between toenail selenium levels and metabolic syndrome (odds ratio = 1.33, 95% confidence interval = 0.58-3.05).

CONCLUSIONS

Multiple lifestyle and dietary factors influenced toenail selenium levels, although no meaningful association was observed between toenail selenium levels and metabolic syndrome in Korean adults. Future prospective large-scale cohort studies are required to determine whether there is a causal relationship between selenium levels and metabolic syndrome in Korean adults.

Femtosecond electron-phonon lock-in by photoemission and x-ray free-electron laser

The interactions that lead to the emergence of superconductivity in iron-based materials remain a subject of debate. It has been suggested that electron-electron correlations enhance electron-phonon coupling in iron selenide (FeSe) and related pnictides, but direct experimental verification has been lacking. Here we show that the electron-phonon coupling strength in FeSe can be quantified by combining two time-domain experiments into a "coherent lock-in" measurement in the terahertz regime. X-ray diffraction tracks the light-induced femtosecond coherent lattice motion at a single phonon frequency, and photoemission monitors the subsequent coherent changes in the electronic band structure. Comparison with theory reveals a strong enhancement of the coupling strength in FeSe owing to correlation effects. Given that the electron-phonon coupling affects superconductivity exponentially, this enhancement highlights the importance of the cooperative interplay between electron-electron and electron-phonon interactions.

Bladder stone formation on permanent suture material ten years after laparoscopic high uterosacral ligament suspension

The present authors describe an uncommon case of iatrogenic bladder stone formation in a patient who underwent surgery for pelvic organ prolapse. A female patient who underwent high uterosacral ligament suspension ten years ago presented with pyuria and irritable bladder symptoms that did not respond to treatment. She had not experienced any specific urinary symptoms during the previous ten years. Patient evaluation revealed bladder stone formation on the non-absorbable suture material used during the previous operation. Cystoscopy during the previous operation did not find the suture material, and the suture knot that was tied extravesically during the operation was found inside the bladder. These strongly suggest delayed migration and rotation of the'suture knot after surgery rather than direct penetration of the bladder during operation. Delayed suture migration is a long-term complication that clinicians should consider in a patient who suffers from recurrent urinary symptoms after pelvic surgery around the bladder.

Observation of Orbital Order in the Half-Filled 4f Gd Compound

Half-filled electron systems, even with the maximized spin angular moment, have been given little attention because of their zero-orbital angular moment according to Hund's rule. Nevertheless, there are several measurements that show evidence of a nonzero orbital moment as well as spin-orbit coupling. Here we report for the first time the orbital order in a half-filled 4f-electron system GdB_{4}, using the resonant soft x-ray scattering at Gd M_{4,5}-edges. Furthermore, we discovered that the development of this orbital order is strongly coupled with the antiferromagnetic spin order. These results clearly demonstrate that even in half-filled electron systems the orbital angular moment can be an important parameter to describe material properties, and may provide significant opportunities for tailoring new correlated electron systems.

Linoleic acid salt with ultrapure soft water as an antibacterial combination against dermato-pathogenic Staphylococcus spp

AIMS

Skin colonization of Staphylococcus spp. critically affects the severity of dermatitis in humans and animals. We examined different types of fatty acid salts for their antibacterial activity against Staphylococcus spp. when used in ultrapure soft water (UPSW). We also evaluated their therapeutic effect on a spontaneous canine model of dermatitis.

METHODS AND RESULTS

UPSW, in which Ca(++) and Mg(++) were replaced with Na(+) , was generated using a water softener with cation-exchange resin. Staphylococcus aureus (Staph. aureus), Staphylococcus intermedius (Staph. intermedius), and Staphylococcus pseudintermedius (Staph. pseudintermedius) were incubated with various fatty acid salts in distilled water (DW) or UPSW and the number of bacteria was counted. Among the fatty acids, oleic acid salt and linoleic acid (LA) salt reduced the number of these bacteria. Also, UPSW enhanced the antibacterial effect of LA on Staph. spp. In spontaneously developed itchy dermatitis in companion dogs, shampoo treatment with liquid soap containing 10% LA in UPSW improved skin conditions.

CONCLUSIONS

LA salt showed antibacterial activity against Staph. spp. Treatment with soap containing LA with UPSW reduced clinical conditions in dogs with dermatitis.

SIGNIFICANCE AND IMPACT OF THE STUDY

Because colonization of Staph. spp. on the skin exacerbates dermatitis, the use of LA-containing soap in UPSW may reduce unpleasant clinical symptoms of the skin.

Discovery of pathogenic variants in a large Korean cohort of inherited muscular disorders

Inherited muscular disorders (IMDs) are clinically and genetically heterogeneous genetic disorders. We investigated the mutational spectrum and genotype-phenotype correlations in Korean patients with IMD. We developed a targeted panel of 69 known IMD genes and recruited a total of 209 Korean patients with IMD. Targeted capture sequencing identified 994 different variants. Among them, 98 variants were classified as pathogenic/likely pathogenic variants; 38 were novel variations. A total of 39 patients had the pathogenic/likely pathogenic variants. Among them, 75 (36%) patients were genetically confirmed, and 18 (9%) patients had one heterozygous variant of recessive myopathy. However, two genetically confirmed patients had an additional heterozygous variant of another recessive myopathy. Four patients with one heterozygous variant of a recessive myopathy showed different phenotypes, compared with the known phenotype of the identified gene. The major causative genes of Korean patients with IMDs were DMD (19 patients), COL6A1 (9), DYSF (9), GNE (7), LMNA (7), CAPN3 (6), and RYR1 (5). This study showed the mutational and clinical spectra in Korean patients with IMD and confirmed the usefulness of strategies utilizing targeted sequencing.

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.

Measurement of the Transverse Single-Spin Asymmetry in p^{↑}+p→W^{±}/Z^{0} at RHIC

We present the measurement of the transverse single-spin asymmetry of weak boson production in transversely polarized proton-proton collisions at sqrt[s]=500  GeV by the STAR experiment at RHIC. The measured observable is sensitive to the Sivers function, one of the transverse-momentum-dependent parton distribution functions, which is predicted to have the opposite sign in proton-proton collisions from that observed in deep inelastic lepton-proton scattering. These data provide the first experimental investigation of the nonuniversality of the Sivers function, fundamental to our understanding of QCD.

GW150914: Implications for the Stochastic Gravitational-Wave Background from Binary Black Holes

The LIGO detection of the gravitational wave transient GW150914, from the inspiral and merger of two black holes with masses ≳30M_{⊙}, suggests a population of binary black holes with relatively high mass. This observation implies that the stochastic gravitational-wave background from binary black holes, created from the incoherent superposition of all the merging binaries in the Universe, could be higher than previously expected. Using the properties of GW150914, we estimate the energy density of such a background from binary black holes. In the most sensitive part of the Advanced LIGO and Advanced Virgo band for stochastic backgrounds (near 25 Hz), we predict Ω_{GW}(f=25  Hz)=1.1_{-0.9}^{+2.7}×10^{-9} with 90% confidence. This prediction is robustly demonstrated for a variety of formation scenarios with different parameters. The differences between models are small compared to the statistical uncertainty arising from the currently poorly constrained local coalescence rate. We conclude that this background is potentially measurable by the Advanced LIGO and Advanced Virgo detectors operating at their projected final sensitivity.

GW150914: The Advanced LIGO Detectors in the Era of First Discoveries

Following a major upgrade, the two advanced detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) held their first observation run between September 2015 and January 2016. With a strain sensitivity of 10^{-23}/sqrt[Hz] at 100 Hz, the product of observable volume and measurement time exceeded that of all previous runs within the first 16 days of coincident observation. On September 14, 2015, the Advanced LIGO detectors observed a transient gravitational-wave signal determined to be the coalescence of two black holes [B. P. Abbott et al., Phys. Rev. Lett. 116, 061102 (2016)], launching the era of gravitational-wave astronomy. The event, GW150914, was observed with a combined signal-to-noise ratio of 24 in coincidence by the two detectors. Here, we present the main features of the detectors that enabled this observation. At full sensitivity, the Advanced LIGO detectors are designed to deliver another factor of 3 improvement in the signal-to-noise ratio for binary black hole systems similar in mass to GW150914.

Beam Energy Dependence of the Third Harmonic of Azimuthal Correlations in Au+Au Collisions at RHIC

We present results from a harmonic decomposition of two-particle azimuthal correlations measured with the STAR detector in Au+Au collisions for energies ranging from sqrt[s_{NN}]=7.7 to 200 GeV. The third harmonic v_{3}^{2}{2}=⟨cos3(ϕ_{1}-ϕ_{2})⟩, where ϕ_{1}-ϕ_{2} is the angular difference in azimuth, is studied as a function of the pseudorapidity difference between particle pairs Δη=η_{1}-η_{2}. Nonzero v_{3}^{2}{2} is directly related to the previously observed large-Δη narrow-Δϕ ridge correlations and has been shown in models to be sensitive to the existence of a low viscosity quark gluon plasma phase. For sufficiently central collisions, v_{3}^{2}{2} persist down to an energy of 7.7 GeV, suggesting that quark gluon plasma may be created even in these low energy collisions. In peripheral collisions at these low energies, however, v_{3}^{2}{2} is consistent with zero. When scaled by the pseudorapidity density of charged-particle multiplicity per participating nucleon pair, v_{3}^{2}{2} for central collisions shows a minimum near sqrt[s_{NN}]=20  GeV.