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.

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.

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.

Removal of congo red using activated carbon and its regeneration

Activated carbon is used for the removal of colored toxic congo red dye. The effects of different operating conditions like, initial dye concentration, contact time, pH and temperature are studied for adsorption of congo red by a known amount of activated carbon (1.0g/L) under stirred batch condition. The zero point of charge of the activated carbon is found about 6.6. About 90% dye is removed for initial concentration of 50 and 100mg/L, it is about 80% at pH 7.0. Maximum adsorption (about 100%) of dye is observed at pH 2.0 for the concentration range studied here. Freundlich isotherm is found to fit the equilibrium data more adequately. Pseudo second order kinetic model explain successfully the kinetic data. The surfactant enhanced carbon regeneration (SECR) technique using both cationic and anionic surfactants is adopted for the regeneration of spent carbon by desorbing the dye. A kinetic model for dye desorption from the commercial activated carbon (CAC) is also proposed. Anionic surfactants show better performance than the cationic ones. Efficiency of dye desorption using surfactants is also compared with the desorption using pH change.

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.

Effects of insertion conditions on tissue strain and vascular damage during neuroprosthetic device insertion

Long-term integration of neuroprosthetic devices is challenged by reactive responses that compromise the brain-device interface. The contribution of physical insertion parameters to immediate damage is not well described. We have developed an ex vivo preparation to capture real-time images of tissue deformation during device insertion using thick tissue slices from rat brains prepared with fluorescently labeled vasculature. Qualitative and quantitative assessments of damage were made for insertions using devices with different tip shapes inserted at different speeds. Direct damage to the vasculature included severing, rupturing and dragging, and was often observed several hundred micrometers from the insertion site. Slower insertions generally resulted in more vascular damage. Cortical surface features greatly affected insertion success; insertions attempted through pial blood vessels resulted in severe tissue compression. Automated image analysis techniques were developed to quantify tissue deformation and calculate mean effective strain. Quantitative measures demonstrated that, within the range of experimental conditions studied, faster insertion of sharp devices resulted in lower mean effective strain. Variability within each insertion condition indicates that multiple biological factors may influence insertion success. Multiple biological factors may contribute to tissue distortion, thus a wide variability was observed among insertions made under the same conditions.

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.

Prostate cancer specific integrin alphavbeta3 modulates bone metastatic growth and tissue remodeling

The management of pain and morbidity due to the spreading and growth of cancer within bone remains to be a paramount problem in clinical care. Cancer cells actively transform bone, however, the molecular requirements and mechanisms of this process remain unclear. This study shows that functional modulation of the alphavbeta3 integrin receptor in prostate cancer cells is required for progression within bone and determines tumor-induced bone tissue transformation. Using histology and quantitative microCT analysis, we show that alphavbeta3 integrin is required not only for tumor growth within the bone but for tumor-induced bone gain, a response resembling bone lesions in prostate cancer patients. Expression of normal, fully functional alphavbeta3 enabled tumor growth in bone (incidence: 4/4), whereas alphavbeta3 (-), inactive or constitutively active mutants of alphavbeta3 did not (incidence: 0/4, 0/6 and 1/7, respectively) within a 35-day-period. This response appeared to be bone-specific in comparison to the subcutis where tumor incidence was greater than 60% for all groups. Interestingly, bone residing prostate cancer cells expressing normal or dis-regulated alphavbeta3 (either inactive of constitutively active), but not those lacking beta3 promoted bone gain or afforded protection from bone loss in the presence or absence of histologically detectable tumor 35 days following implantation. As bone is replete with ligands for beta3 integrin, we next demonstrated that alphavbeta3 integrin activation on tumor cells is essential for the recognition of key bone-specific matrix proteins. As a result, prostate cancer cells expressing fully functional but not dis-regulated alphavbeta3 integrin are able to control their own adherence and migration to bone matrix, functions that facilitate tumor growth and control bone lesion development.

Avena sativa (Oat), a potential neutraceutical and therapeutic agent: an overview

The aim of the present review article is to summarize the available information related to the availability, production, chemical composition, pharmacological activity, and traditional uses of Avena sativa to highlight its potential to contribute to human health. Oats are now cultivated worldwide and form an important dietary staple for the people in number of countries. Several varieties of oats are available. It is a rich source of protein, contains a number of important minerals, lipids, β-glucan, a mixed-linkage polysaccharide, which forms an important part of oat dietary fiber, and also contains various other phytoconstituents like avenanthramides, an indole alkaloid-gramine, flavonoids, flavonolignans, triterpenoid saponins, sterols, and tocols. Traditionally oats have been in use since long and are considered as stimulant, antispasmodic, antitumor, diuretic, and neurotonic. Oat possesses different pharmacological activities like antioxidant, anti-inflammatory, wound healing, immunomodulatory, antidiabetic, anticholesterolaemic, etc. A wide spectrum of biological activities indicates that oat is a potential therapeutic agent.

Resistance in series model for micellar enhanced ultrafiltration of eosin dye

A study has been performed to quantify the extent of flux decline during micellar enhanced ultrafiltration (MEUF) of an acid dye (eosin red) using hexadecyl (cetyl) pyridinium chloride as the cationic surfactant. Effects of the operating conditions, e.g., transmembrane pressure drop and feed-surfactant-to-dye ratio, on the permeate flux profile and observed retention have been investigated in an unstirred batch ultrafiltration (UF) cell. A simple resistance-in-series model has been used to quantify the flux decline. From the flux decline history, it has been found that the membrane permeability decreases rapidly due to reversible pore blocking and further flux decline is caused by the growth of a gel-type layer over the membrane surface. The different resistances and growth kinetics of the gel layer have been investigated as functions of the operating conditions.

Field-free orientation of CO molecules by femtosecond two-color laser fields

We report the first experimental observation of nonadiabatic field-free orientation of a heteronuclear diatomic molecule (CO) induced by an intense two-color (800 and 400 nm) femtosecond laser field. We monitor orientation by measuring fragment ion angular distributions after Coulomb explosion with an 800 nm pulse. The orientation of the molecules is controlled by the relative phase of the two-color field. The results are compared to quantum mechanical rigid rotor calculations. The demonstrated method can be applied to study molecular frame dynamics under field-free conditions in conjunction with a variety of spectroscopy methods, such as high-harmonic generation, electron diffraction, and molecular frame photoelectron emission.

Elliptic flow of charged particles in Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sqrt[S(NN)] =2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2<p t<5.0 GeV/c. The elliptic flow signal v₂, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ± 0.002(stat) ± 0.003(syst) in the 40%-50% centrality class. The differential elliptic flow v₂ p t reaches a maximum of 0.2 near p t =3 GeV/c. Compared to RHIC Au-Au collisions at sqrt[S(NN)] 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.

IL-1 beta and IL-6 induce hyperplasia and hypertrophy of cultured guinea pig airway smooth muscle cells

Guinea pig airway smooth muscle (ASM) cells were maintained in a primary tissue culture (passages 1-3). Cells were exposed to human recombinant interleukin-1 beta (IL-1 beta; 20-100 pg/ml) or interleukin-6 (IL-6; 1-4 ng/ml) in the presence of indomethacin (1 microgram/ml) for up to 5 days. Proliferation of ASM cells was assessed with two techniques, direct counting of cells with a hemacytometer and [3H]thymidine incorporation corrected for total protein content. Hypertrophy of ASM cells was assessed by [3H]leucine incorporation (evaluation of protein synthesis), determination of total DNA content, DNA content per cell, and protein content per cell. We observed that the exposure of ASM cells to human recombinant IL-1 beta or IL-6, in all studied concentrations, significantly increased the number of cells as well as [3H]thymidine incorporation into ASM cells. We also found that exposure of ASM to these two cytokines increased [3H]leucine incorporation into the ASM cells and increased protein content and DNA content per single cell. These changes were also concentration dependent. We conclude that the two proinflammatory cytokines, IL-1 beta and IL-6, which are present in asthmatic lungs, increased the proliferation of ASM cells (hyperplasia) as well as their overall size and size of their nuclei, as measured by biochemical markers. These findings are compatible with the presence of ASM hypertrophy.

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.

Centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV

The centrality dependence of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of 2 from peripheral (70%-80%) to central (0%-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.

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.

Higher harmonic anisotropic flow measurements of charged particles in Pb-Pb collisions at sqrt(s(NN)) = 2.76 TeV

We report on the first measurement of the triangular v3, quadrangular v4, and pentagonal v5 charged particle flow in Pb-Pb collisions at sqrt(s(NN)) = 2.76  TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy and its fluctuations, which provides strong constraints on its origin. In the most central events, where the elliptic flow v2 and v3 have similar magnitude, a double peaked structure in the two-particle azimuthal correlations is observed, which is often interpreted as a Mach cone response to fast partons. We show that this structure can be naturally explained from the measured anisotropic flow Fourier coefficients.

Immune response of children who develop persistent diarrhea following rotavirus infection

A prospective study was conducted with Bangladeshi children with rotavirus (RV) diarrhea to assess whether nutritional and clinical parameters, RV serotypes, levels of interleukin-10 (IL-10), tumor necrosis factor alpha (TNF-alpha), and gamma interferon (IFN-gamma), and RV-specific antibody titers in plasma and stool were associated with the development of persistent diarrhea. Children with watery diarrhea for 6 to 8 days, selected from the Dhaka Hospital of the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), were enrolled in the study and monitored until diarrhea improved. Children were classified as having acute diarrhea (AD) if diarrhea resolved within 14 days of onset and as having persistent diarrhea (PD) if diarrhea persisted for more than 14 days after onset. Uninfected, control children (n = 13) from the Nutrition Follow-Up Unit of ICDDR,B were also enrolled. Of the 149 children with diarrhea enrolled, 29 had diarrhea with RV alone, of which 19 had AD and 10 developed PD. Samples of stool and blood were collected from all children on enrollment. Stool samples were collected again from children when they developed PD. Of the 10 children who had an initial RV infection and then developed PD, only one had persistent RV infection. Plasma levels of IL-10 and TNF-alpha were higher in children with diarrhea compared to uninfected controls but were similar in children with AD and PD. Plasma IFN-gamma levels were higher in children who developed PD than in those with AD (P = 0.008) or uninfected controls (P = 0.001). In stools, the levels of TNF-alpha, the only cytokine detected, were similar in the three groups of children. RV-specific immunoglobulin G (IgG) titers in plasma were higher in uninfected children than in those with AD (P < 0.001) or PD (P = 0.024) but titers were similar in children with AD and PD. RV-specific IgA titers in plasma and stool were similar in the three groups of children. From all observed parameters, only elevated plasma IFN-gamma levels were associated with subsequent development of PD. However, a larger sample size is necessary to substantiate this observation.

Ion-energy dependence of asymmetric dissociation of D2 by a two-color laser field

Two-color (800 and 400 nm) short (45 fs) linearly polarized pulses are used to ionize and dissociate D2 into a neutral deuterium atom and a deuteron. The yields and energies of the ions are measured left and right along the polarization vector. As the relative phase of the two colors is varied, strong yield asymmetries are found in the ion-energy regions traditionally identified as bond softening, above-threshold dissociation and rescattering. The asymmetries in these regions are quite different. A model based on the dynamic coupling by the laser field of the gerade and ungerade states in the molecular ion accounts for many of the observed features.