Constraints on cosmic strings from the LIGO-Virgo gravitational-wave detectors

Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs from cosmic microwave background measurements and pulsar timing data. In particular, if the size of loops is given by the gravitational backreaction scale, we place upper limits on the string tension Gμ below 10(-8) in some regions of the cosmic string parameter space.

Near-self-imaging cavity for three-mode optoacoustic parametric amplifiers using silicon microresonators

Three-mode optoacoustic parametric amplifiers (OAPAs), in which a pair of photon modes are strongly coupled to an acoustic mode, provide a general platform for investigating self-cooling, parametric instability and very sensitive transducers. Their realization requires an optical cavity with tunable transverse modes and a high quality-factor mirror resonator. This paper presents the design of a table-top OAPA based on a near-self-imaging cavity design, using a silicon torsional microresonator. The design achieves a tuning coefficient for the optical mode spacing of 2.46  MHz/mm. This allows tuning of the mode spacing between amplification and self-cooling regimes of the OAPA device. Based on demonstrated resonator parameters (frequencies ∼400  kHz and quality-factors ∼7.5×10(5) we predict that the OAPA can achieve parametric instability with 1.6 μW of input power and mode cooling by a factor of 1.9×10(4) with 30 mW of input power.

Effects of river morphology, hydraulic gradients, and sediment deposition on water exchange and oxygen dynamics in salmonid redds

Fine sediment decreasing gravel permeability and oxygen supply to incubating salmonid embryos, is often considered the main contributing factor for the observed decline of salmonid populations. However, oxygen supply to salmonid embryos also depends on hydraulic conditions driving water flow through the redd. A more generalized perspective is needed to better understand the constraints on successful salmonid incubation in the many heavily modified fluvial ecosystems of the Northern Hemisphere. The effects of hydraulic gradients, riverbed and redd morphology as well as fine sediment deposition on dissolved oxygen (DO) and water exchange was studied in 18 artificial redds at three sites along a modified river. Fifty percent of the redds in the two downstream sites were lost during high flow events, while redd loss at the upstream site was substantially lower (8%). This pattern was likely related to increasing flood heights from up- to downstream. Specific water infiltration rates (q) and DO were highly dynamic and driven on multiple temporal and spatial scales. Temporally, the high permeability of the redd gravel and the typical pit-tail structure of the new built redds, leading to high DO, disappeared within a month, when fine sediment had infiltrated and the redd structure was leveled. On the scale of hours to days, DO concentrations and q increased during high flows, but decreased during the falling limb of the water level, most likely related to exfiltration of oxygen depleted groundwater or hyporheic water. DO concentrations also decreased under prolonged base flow conditions, when increased infiltration of silt and clay particles clogged the riverbed and reduced q. Spatially, artificial log steps affected fine sediment infiltration, q and interstitial DO in the redds. The results demonstrate that multiple factors have to be considered for successful river management in salmonid streams, including riverbed structure and local and regional hydrogeological conditions.

External cavity enhancement of picosecond pulses with 28,000 cavity finesse

We report on the first demonstration, to the best of our knowledge, of the locking of a Fabry-Perot cavity with a finesse of 28,000 in the pulsed regime. The system is based on a stable picosecond oscillator, an ultrastable cavity with high-reflection mirrors, and an all-numerical feedback system that allows efficient and independent control of the repetition rate and the pulse to pulse carrier-to-envelop phase drift (CEP). We show that the carrier to envelop phase can have a dramatic effect even for pulses with hundreds of cycles. Moreover, we have succeeded in unambiguously measuring the CEP of a 2 ps pulse train. Finally, we discuss the potential of our findings to reach the MW average power level stored in an external cavity enhancement architecture.

Prism adaptation and neck muscle vibration in healthy individuals: are two methods better than one?

Studies involving therapeutic combinations reveal an important benefit in the rehabilitation of neglect patients when compared to single therapies. In light of these observations our present work examines, in healthy individuals, sensorimotor and cognitive after-effects of prism adaptation and neck muscle vibration applied individually or simultaneously. We explored sensorimotor after-effects on visuo-manual open-loop pointing, visual and proprioceptive straight-ahead estimations. We assessed cognitive after-effects on the line bisection task. Fifty-four healthy participants were divided into six groups designated according to the exposure procedure used with each: 'Prism' (P) group; 'Vibration with a sensation of body rotation' (Vb) group; 'Vibration with a move illusion of the LED' (Vl) group; 'Association with a sensation of body rotation' (Ab) group; 'Association with a move illusion of the LED' (Al) group; and 'Control' (C) group. The main findings showed that prism adaptation applied alone or combined with vibration showed significant adaptation in visuo-manual open-loop pointing, visual straight-ahead and proprioceptive straight-ahead. Vibration alone produced significant after-effects on proprioceptive straight-ahead estimation in the Vl group. Furthermore all groups (except C group) showed a rightward neglect-like bias in line bisection following the training procedure. This is the first demonstration of cognitive after-effects following neck muscle vibration in healthy individuals. The simultaneous application of both methods did not produce significant greater after-effects than prism adaptation alone in both sensorimotor and cognitive tasks. These results are discussed in terms of transfer of sensorimotor plasticity to spatial cognition in healthy individuals.

Activity of Drill® lozenges on the main microorganisms responsible for upper respiratory tract infections

OBJECTIVES

The treatment of sore throat, considered to be essentially due to viral infection, does not require the use of antibiotics. The recommended treatment is therefore based on the use of topical anaesthetics and antiseptics. Throat lozenges play a leading role in topical treatment by allowing immediate, massive and persistent release of the active molecule at the site of infection. The objective of this study was to demonstrate the short-term and long-term in vitro antimicrobial efficacy of Drill(®) lozenges in relation to the main pathogens responsible for upper respiratory tract infections.

MATERIAL AND METHOD

The bactericidal and virucidal activity in relation to the main microorganisms responsible for upper respiratory tract infections, including the H1N1 influenza virus, was evaluated after short (5 minutes) and long (3h) contact times, according to a methodology complying with European standards for the evaluation of chemical antiseptics and disinfectants. In parallel, the global antibacterial activity was determined on 30 strains representative of the resident flora by determination of maximum inhibitory dilutions (MID) and maximum bactericidal dilutions (MBD).

RESULTS

Drill(®) lozenges presented an antibacterial activity inducing significant (>90%) destruction of the main upper respiratory tract pathogens after a 5-minute contact time at high concentration and after a 3-hour contact time after dilution. Drill(®) lozenges also exerted an antiviral activity inducing 2 log (99%) destruction of the H1N1 virus after a 5-min contact time at high concentration, with maintenance of this activity after dilution (3h). A homogeneous antibacterial activity was observed on the resident flora.

CONCLUSION

These in vitro tests confirm the value of chlorhexidine lozenges in the treatment of upper respiratory tract infections such as sore throat.

Phase I trial of gemcitabine combined with capecitabine and erlotinib in advanced pancreatic cancer: a clinical and pharmacological study

BACKGROUND

The aim of this phase I trial was to define the maximum tolerated dose (MTD), the dose-limiting toxicity (DLT) and the recommended dose of erlotinib combined with capecitabine and gemcitabine in the treatment of advanced pancreatic cancer (APC).

METHODS

Gemcitabine was administered intravenously at 1,000 mg/m(2)/week (days 1, 8 and 15) and oral capecitabine from day 1 to day 21 at 1,660 mg/m(2)/day. Oral erlotinib was administered daily continuously at escalating doses (28-day cycle). Dose levels (DLs) 1, 2, 3 and 4 were 50, 75, 100 and 125 mg/day, respectively. Pharmacokinetic analysis of the three drugs was performed in the first cycle.

RESULTS

Nineteen patients were enrolled. At the MTD (DL4; 125 mg/day erlotinib), 100% of patients developed DLT consisting of grade 4 febrile neutropenia and nonhematological grade 3 events (vomiting, diarrhea, stomatitis, rash). The most common toxicities, regardless of grade, were neutropenia, anemia, rash and diarrhea. Erlotinib systemic exposure was significantly related to the administered dose. Of note, toxicity was significantly associated with elevated systemic exposure of capecitabine anabolites.

CONCLUSION

When combined concurrently with 1,000 mg/m(2)/week gemcitabine and 1,660 mg/m(2)/day capecitabine, erlotinib can be administered safely at a daily dose of 100 mg in APC patients.

Cisplatin-docetaxel induction plus concurrent 3-D conformal radiotherapy and weekly chemotherapy for locally advanced non-small cell lung cancer patients: a phase II trial

Concurrent chemoradiotherapy (CHRT) is the standard of care for unresectable locally advanced stage III non-small cell lung cancer. However, the optimal combination remains unclear. The aim of this study was to evaluate the efficacy of 2 induction chemotherapy cycles (days 1 and 22) with docetaxel 75 mg/m(2) and cisplatin 75 mg/m(2) followed by concurrent chemotherapy (weekly docetaxel-cisplatin, 20 mg/m(2)) and 3-D conformal radiotherapy for 6 weeks (66 Gy/5 fractions per week/2 Gy per fraction). The primary endpoint was the response rate. Secondary objectives were toxicity, time to progression, and overall survival. Forty-four patients were included and 40 were eligible. The mean age was 60.5 years (range 40.7-72.1), and 75% had stage IIIB disease. Six patients underwent complete R0 resection including 2 pathologic complete responses after a planned intermediate evaluation. Thirty-three patients completed CHRT. The objective response rate was 65% (95% CI 50.2-79.8). Grade 3-4 hematologic and digestive toxicities were observed mainly during the induction phase. Grade 3 esophagitis (5%) was experienced during CHRT. With a median follow-up of 38.7 months, the median progression-free survival was 28.3 months (95% CI 11.0-35.0) and the median survival rate was 31.4 months. Cisplatin-docetaxel induction followed by concurrent 3-D conformal radiotherapy and weekly chemotherapy is a feasible protocol associated with a promising response rate and acceptable toxicity.

Diagnosis and management of melanoma with regional lymph node metastases: a population-based study in France

BACKGROUND

Stage III melanoma represents a borderline situation regarding the potential curability of this potentially aggressive cancer and consequently, regional lymph node metastases (RLNM) are a major challenge for melanoma management.

OBJECTIVE

To describe the management of melanoma with RLNM as practised in France in 2008 and compare results with previous data from 2004, considering that new French recommendations were published in 2005.

METHODS

Retrospective population-based study in five regions of France totalling 8.3 million inhabitants, targeting all incident cases of RLNM diagnosed in 2008. Questionnaires were mailed to physicians to identify cases and collect data, with verification by cancer registries for cases diagnosed concomitantly with the primary tumour using sentinel lymph node biopsies (SLNB).

RESULTS

Data were collected for 101 patients in 2008, and compared to 89 cases treated in 2004. Palpation by a dermatologist was the most common circumstance of diagnosis of RLNM in 2008 (36%), followed by SLNB (29%), self-palpation by the patient (16%) and lymph node ultrasonography (6%), without significant modification from 2004. After lymphadenectomy an adjuvant therapy was proposed in 62% of cases, mainly consisting in high-dose interferon (HD-IFN) (80%). Overall, HD-IFN was proposed in 49% of cases, but effectively started in only 40% of cases after being proposed, and prematurely withdrawn in 28%, showing major changes as compared with 2004 (33%, 77% and 67%, respectively, P < 0.05). Adjuvant chemotherapy was not proposed to any patients in 2008, compared to 29% in 2004. Surveillance procedures included medical imaging less often in 2008 (76%) than in 2004 (92%) (P = 0.004), but more often included FDG-PET (23% vs. 12%, P = 0.09).

CONCLUSION

Overall, actual practice was in accordance with French recommendations. The main developments from 2004 to 2008 were the disappearance of adjuvant chemotherapies and a more accurate selection of patients for adjuvant interferon.

OS060. Exercise training promotes placental growth and development in an animal model of preeclampsia superimposed on chronic hypertension

INTRODUCTION

Chronic hypertension is an important risk factor for preeclampsia, increasing the prevalence of the disease to 15-25% in pregnant women. Unfortunately there are no known treatments for this disease aside from inducing delivery of the fetus. Nonetheless, several studies have found exercise training to have a protective effect on the risk of developing preeclampsia.

OBJECTIVES

To determine the mechanisms implicated in the preventive effect of exercise training on preeclampsia, by focusing on the placenta.

METHODS

Double transgenic mice, overexpressing both human renin and angiotensinogen (R(+)/A(+)), were used to investigate the effect of exercise training on an animal model of preeclampsia superimposed on chronic hypertension. Mice were placed in cages with free access to an exercise wheel 4 weeks prior to and during pregnancy. At gestational day 18, mice were sacrificed and their organs were collected. Real time PCR and Western Blot were performed to evaluate placental genes and proteins, respectively. Circulating sFlt-1(soluble Fms-like tyrosine kinase-1) levels were investigated by ELISA. Placental alterations were assessed by histology and immunohistochemistry, while blood pressure was measured by radiotelemetry.

RESULTS

Sedentary R(+)/A(+) mice presented with significantly greater placental pathology, which was normalized with exercise training. This was characterized by a normalization of cytokeratin and histone H3 protein expression, thereby restoring placental development, specifically looking at trophoblasts and trophoblast giant cells, respectively. This exercise training effect appears to normalize placental growth primarily by promoting angiogenesis and development. Indeed, a pro-angiogenic shift could be detected which was characterized by an increase in placental growth factor gene expression, along with a decrease in sFlt-1 gene expression, which produced a decrease in circulating sFlt-1. Sedentary R(+)/A(+) mice also presented with a significant increase in VEGF protein, which was significantly decreased with exercise. Of interest, since it has been observed to be decreased with preeclampsia, insulin regulated aminopeptidase (IRAP) gene expression was significantly increased in the trained transgenic mice. Finally, exercise training prevented the increase in blood pressure normally observed at the end of gestation in sedentary R(+)A(+) mice.

CONCLUSION

Exercise training both before and during gestation appears to promote placental growth and development by producing a pro-angiogenic placental environment. Put together, along with the lack in blood pressure increase, these factors may be responsible for preventing the development of preeclampsia in our animal model of preeclampsia superimposed on chronic hypertension. Identifying the mechanisms implicated in exercise-induced preeclampsia risk reduction will be critical to improve preeclampsia prophylaxis.

Temporal dynamics of incoherent waves in noninstantaneous response nonlinear Kerr media

We consider the temporal evolution of an incoherent optical wave that propagates in a noninstantaneous response nonlinear medium, such as single mode optical fibers. In contrast with the expected Raman-like spectral redshift due to a delayed nonlinear response, we show that a highly noninstantaneous response leads to a genuine modulational instability of the incoherent optical wave. We derive a Vlasov-like kinetic equation that provides a detailed description of this process of incoherent modulational instability in the temporal domain.

Experimental phase-space-based optical amplification of scar modes

Wave billiards which are chaotic in the geometrical limit are known to support nongeneric spatially localized modes called scar modes. The interaction of the scar modes with gain has been recently investigated in optics in microcavity lasers and vertical-cavity surface-emitting lasers. Exploiting the localization properties of scar modes in their wave-analogous phase-space representation, we report experimental results of scar mode selection by gain in a doped D-shaped optical fiber.

Directional limits on persistent gravitational waves using LIGO S5 science data

The gravitational-wave (GW) sky may include nearby pointlike sources as well as stochastic backgrounds. We perform two directional searches for persistent GWs using data from the LIGO S5 science run: one optimized for pointlike sources and one for arbitrary extended sources. Finding no evidence to support the detection of GWs, we present 90% confidence level (C.L.) upper-limit maps of GW strain power with typical values between 2-20×10(-50)  strain(2) Hz(-1) and 5-35×10(-49)  strain(2) Hz(-1) sr(-1) for pointlike and extended sources, respectively. The latter result is the first of its kind. We also set 90% C.L. limits on the narrow-band root-mean-square GW strain from interesting targets including Sco X-1, SN 1987A and the Galactic center as low as ≈7×10(-25) in the most sensitive frequency range near 160 Hz.

Emergence of spectral incoherent solitons through supercontinuum generation in a photonic crystal fiber

We report an experimental and numerical study of the spontaneous emergence of spectral incoherent solitons through supercontinuum generation in a two zero-dispersion wavelengths photonic crystal fiber. By using a simple experimental setup, we show that the highly nonlinear regime of supercontinuum generation is characterized by the emergence of a spectral incoherent soliton in the low-frequency edge of the supercontinuum spectrum. We show that a transition occurs from the discrete spectral incoherent soliton to its continuous counterpart as the power of the laser is increased. Contrary to conventional solitons, spectral incoherent solitons do not exhibit a confinement in the space-time domain, but solely in the frequency domain. These incoherent structures owe their existence to the noninstantaneous nature of the nonlinear Raman effect and, more specifically, to the causality property underlying the Raman response function.

A phase I study of UFT-oral vinorelbine in metastatic breast cancer

BACKGROUND

Despite current treatment options, metastatic breast cancer (MBC) remains essentially incurable, requiring research on new drugs or combinations to improve survival and quality of life.

PATIENTS AND METHODS

This phase I study was designed to define the maximum-tolerated dose (MTD), dose-limiting toxicity (DLT) and recommended dose of all-oral tegafur-uracil (UFT)/folinic acid combined with vinorelbine as chemotherapy for MBC. Starting doses were 40 mg/m(2)/week of oral vinorelbine administered continuously and 250 mg/m(2)/day of UFT plus 90 mg/day of folinic acid from day 1 to day 28, followed by a 1-week rest period.

RESULTS

Ten patients were included. Eight were evaluable for toxicity and antitumor response. The second dose level was shown to be the MTD. At this dose, 2 out of 5 patients receiving oral vinorelbine at 40 mg/m(2)/week and UFT at 300 mg/m(2)/day developed DLT consisting of grade 3 asthenia and grade 3 nausea despite standard prophylaxis. Other toxicities were grade 1 diarrhea and anemia. There were no treatment-related deaths.

CONCLUSIONS

The recommended dose for this combination seems to be the first dose level. A stable response was observed for 6 patients (average 33 weeks). This combination appears to be well-tolerated and offers an alternative to intravenous chemotherapy.

A state observer for the Virgo inverted pendulum

We report an application of Kalman filtering to the inverted pendulum (IP) of the Virgo gravitational wave interferometer. Using subspace method system identification techniques, we calculated a linear mechanical model of Virgo IP from experimental transfer functions. We then developed a Kalman filter, based on the obtained state space representation, that estimates from open loop time domain data, the state variables of the system. This allows the observation (and eventually control) of every resonance mode of the IP mechanical structure independently.

Toward a new generation of low-loss mirrors for the advanced gravitational waves interferometers

The new generation of advanced interferometer needs fused silica mirrors having better optical and mechanical properties. This Letter describes the way to reduce the ion beam sputtering coating absorption at 1064 nm and to improve the layer thickness uniformity in order to coat two large mirrors (diameter 35 cm) at the same time.

Prevalence and Burden of at-Risk Criteria of Psychosis and Help-Seeking Behaviour - a Population Survey

Objective

In the discussion of the inclusion of an at-risk syndrome of psychosis in DSM-V, the validity of current at-risk criteria had been questioned based on studies reporting much higher prevalence rates of psychotic-like experiences in general population samples (GPS) compared to psychotic disorders. Thus the 3-month prevalence of at-risk criteria and symptoms in GPS, age 16–35, was assessed by trained clinicians in telephone interviews using established standardized assessments.

Methods

Of 85 enrolled persons, 60 persons (70.5%) participated, two of them met exclusion criteria (psychosis, language problems). The 22 psychopathological at-risk symptoms were assessed for their occurrence and severity within the three months prior to the telephone interview using the

(i)

Results

Only one person (1.7%) fulfilled ‘attenuated psychotic symptoms’ (APS)-criteria according to SIPS. At 1.7%, the 3-month prevalence of at-risk criteria was rather low; at 20.7%, the prevalence of sub-threshold at-risk symptoms, however, was much higher. Yet the presence of these sub-threshold symptoms was already associated with lower psychosocial functioning and with psychiatric axis I diagnoses.

Manifestation of Hamiltonian monodromy in nonlinear wave systems

We show that the concept of dynamical monodromy plays a natural fundamental role in the spatiotemporal dynamics of counterpropagating nonlinear wave systems. By means of an adiabatic change of the boundary conditions imposed to the wave system, we show that Hamiltonian monodromy manifests itself through the spontaneous formation of a topological phase singularity (2π- or π-phase defect) in the nonlinear waves. This manifestation of dynamical Hamiltonian monodromy is illustrated by generic nonlinear wave models. In particular, we predict that its measurement can be realized in a direct way in the framework of a nonlinear optics experiment.

A computational model of the primary auditory neuron activity

Sound translation into neural message at the first auditory synapse is of prime importance for providing organism with sound environment. Here, we compiled experimental features of the primary auditory neurons into a computational model, composed of two distinct compartments (i.e., afferent bouton and axon). Simulation of the model closely reproduces the whole biophysical properties of both excitatory post-synaptic currents and action potentials firing. This simple model provides a powerful tool to understand the synaptic disorders on the sound neural coding at the first auditory synapse.

In-vacuum Faraday isolation remote tuning

In-vacuum Faraday isolators (FIs) are used in gravitational wave interferometers to prevent the disturbance caused by light reflected back to the input port from the interferometer itself. The efficiency of the optical isolation is becoming more critical with the increase of laser input power. An in-vacuum FI, used in a gravitational wave experiment (Virgo), has a 20 mm clear aperture and is illuminated by an almost 20 W incoming beam, having a diameter of about 5 mm. When going in vacuum at 10(-6) mbar, a degradation of the isolation exceeding 10 dB was observed. A remotely controlled system using a motorized lambda=2 waveplate inserted between the first polarizer and the Faraday rotator has proven its capability to restore the optical isolation to a value close to the one set up in air.