Proposal for gravitational-wave detection beyond the standard quantum limit through EPR entanglement

The Standard Quantum Limit in continuous monitoring of a system is given by the trade-off of shot noise and back-action noise. In gravitational-wave detectors, such as Advanced LIGO, both contributions can simultaneously be squeezed in a broad frequency band by injecting a spectrum of squeezed vacuum states with a frequency-dependent squeeze angle. This approach requires setting up an additional long base-line, low-loss filter cavity in a vacuum system at the detector's site. Here, we show that the need for such a filter cavity can be eliminated, by exploiting EPR-entangled signal and idler beams. By harnessing their mutual quantum correlations and the difference in the way each beam propagates in the interferometer, we can engineer the input signal beam to have the appropriate frequency dependent conditional squeezing once the out-going idler beam is detected. Our proposal is appropriate for all future gravitational-wave detectors for achieving sensitivities beyond the Standard Quantum Limit.Comment: 16 pages, 7 figure

All-sky search for gravitational-wave bursts in the second joint LIGO-Virgo run

We present results from a search for gravitational-wave bursts in the data collected by the LIGO and Virgo detectors between July 7, 2009 and October 20, 2010: data are analyzed when at least two of the three LIGO-Virgo detectors are in coincident operation, with a total observation time of 207 days. The analysis searches for transients of duration < 1 s over the frequency band 64-5000 Hz, without other assumptions on the signal waveform, polarization, direction or occurrence time. All identified events are consistent with the expected accidental background. We set frequentist upper limits on the rate of gravitational-wave bursts by combining this search with the previous LIGO-Virgo search on the data collected between November 2005 and October 2007. The upper limit on the rate of strong gravitational-wave bursts at the Earth is 1.3 events per year at 90% confidence. We also present upper limits on source rate density per year and Mpc^3 for sample populations of standard-candle sources. As in the previous joint run, typical sensitivities of the search in terms of the root-sum-squared strain amplitude for these waveforms lie in the range 5 10^-22 Hz^-1/2 to 1 10^-20 Hz^-1/2. The combination of the two joint runs entails the most sensitive all-sky search for generic gravitational-wave bursts and synthesizes the results achieved by the initial generation of interferometric detectors.Comment: 15 pages, 7 figures: data for plots and archived public version at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=70814&version=19, see also the public announcement at http://www.ligo.org/science/Publication-S6BurstAllSky

Gender differences and effects of acute and chronic oxytocin on social interaction in mice

This journal supplement has title: Abstracts of the 3rd Biennial Conference of the Schizophrenia International Research SocietyBACKGROUND: Understanding emotion from others is an essential ability for the healthy development of all mammals. Anomalies in emotion processing are associated with developmental disorders such as schizophrenia and autism. Oxytocin is a nine amino-acid peptide (nonapeptide) hormone. It is well-known for its role in lactation and parturition, but it also has a key role in social recognition. Oxytocin has been suggested as a potential therapy in neurodevelopmental disorders such as schizophrenia and autism spectrum, however direct experimental investigation of the action of oxytocin is still limited. The aim of the present study was to explore acute and chronic dose-related effects of oxytocin on social interaction activity in male and female mice. METHODS: 8 week old adult C57BL/6N mice were obtained from the Laboratory Animal Unit at The University of Hong Kong. The experimental protocol was approved by the Committee on the Use of Live Animals for teaching and Research, University of Hong Kong (CULATR case NO: 2152-10). In the chronic administration group, a single injection of 10ug/kg, 100ug/kg, or 1000ug/kg oxytocin (Sigam-Aldrich) was given subcutaneously once a week for two weeks as part of a larger study on chronic effects of oxytocin. Social interaction test was conducted one week after the last oxytocin exposure. Mice received oxytocin injection 30min before test. In the acute administration group, another batch of mice was tested in the same way without previous exposure to oxytocin. Additional untreated mice received saline injection 30min before the social interaction test and were included as controls. The social interaction test conducted followed standard protocols in our lab. An experimental mouse paired with a “neutral” stimulus mouse from the same gender are tested together and scored as a single unit. The mice are put in opposite corners of the arena facing away from each other before the start of the 10-min social interaction test. Mice social interaction times were scored manually. RESULTS: In the control group, the male mice had longer social interaction time with strangers than female mice (P<0.05). In the oxytocin acute administration group, the social interaction time was increased with the increasing oxytocin doses in the female mice (P<0.05). There was a significant linear relationship between social interaction time and oxytocin doses. However, the oxytocin dose-effect curve showed an inverted U shape in the male mice. Both 100ug/kg and 1000ug/kg oxytocin increased social interaction activity in the male mice, but the maximal effect was obtained at 100ug/kg of oxytocin administration. In the oxytocin chronic administration, previous oxytocin exposures increased social interaction time in the female mice for all doses of oxytocin (P<0.05). The oxytocin dose-effect curve for the male mice in the chronic administration group had a similar inverted U shape as the acute administration, with the peak effect at 100ug/kg oxytocin administration (P<0.05). DISCUSSION: The social interaction measure in C57BL/6N mice is gender dependent. Male and female mice also have different responses to acute and chronic administration of oxytocin. Therefore, gender differences need to be carefully considered for further investigations into the utility of oxytocin.The 3rd Biennial Conference of the Schizophrenia International Research Society (SIRS), Florence, Italy, 14-18 April 2012. In Schizophrenia Research, 2012, p. S361, poster no. 22

Oxygen restriction of neonate mouse elevates HIF-1α, IL-6,NF-κb and caspase-3 protein levels: possible relationship to neurodevelopmental disorders

This journal supplement has title: Abstracts of the 3rd Biennial Conference of the Schizophrenia International Research SocietyBACKGROUND: The etiological and biological mechanisms of neuropsychiatric disorders, such asschizophrenia and autism, are incompletely understood. Albeit genetic plays a major role in disease pathogenesis, about 20-30% of causation is estimated to be non-genetic or environmental. Human epidemiological studies have provided strong evidence that prenatal and/or perinatal exposure to various environmental insults, like obstetric complications, increased risk for later development of schizophrenia/autism. Animal models of obstetric complications in form of perinatal hypoxia have reliably demonstrated that a brief period of severe and acute hypoxia/ ischemia can initiate the causal sequences leading to neuronal death in otherwise healthy animals, while inappropriate activation of the apoptotic programme accounts for at least part of the cell death seen after transient hypoxia-ischemia. In attempt to delineate the possible effects of obstetric complications to the etiology of the neurodevelopmental disorders, like schizophrenia/autism, mouse model of perinatal hypoxia was used to determine whether inflammation and apoptosis are involved in the diseases pathogenesis. The expression of transcription factors, HIF-1α and NF-κB, inflammatory mediator, IL-6, and apoptotic protein, caspase-3 in the prefrontal cortex (PFC) of neonatal hypoxic mice were examined. METHODS: C57BL/6N mice were used. On postnatal day (PD) 7, mice pups were subjected to normobaric hypoxia (exposed to air mixture of 8% O2, 0.03% CO2,balance N2) versus air (exposed to air mixture of 20% O2, 0.03% CO2, balance N2) for 120 min. Following a 10 min recovery period in air, pups were returned and raised by their dam until weaning on PD21. Mice on PD84 (early adulthood) were sacrificed. The protein expression level of PFC were analysed by Western Blot and ELISA kit (Enzyme-Linked ImmunoSorbent Assay). RESULTS: We found increased expression levels of HIF-1α, NFκB and caspase-3 in the hypoxia induced mice when compared with the age-matched normoxic controls. We also found that level of IL-6 was increased in brain homogenate but not in the serum. DISCUSSION: These data suggest that obstetric complications in the form of perinatal hypoxia may lead to inflammation and apoptosis, which may contribute to increase risk of neurodevelopmental disorders such as schizophrenia/autism.The 3rd Biennial Conference of the Schizophrenia International Research Society (SIRS), Florence, Italy, 14-18 April 2012. In Schizophrenia Research, 2012, v. 136 suppl. 1, p. S190, poster no. 1

Maternal immune activation in the early or late pregnancy leads to the different behavioral abnormalities of the adult offspring relevant to the schizophrenia

This journal supplement has title: Abstracts of the 3rd Biennial Conference of the Schizophrenia International Research SocietyBACKGROUND: Maternal infection increases the risk for schizophrenia in the offspring suggests that the maternal immune system plays a key role in the psychopathology of schizophrenia. In a mouse model, maternal immune activation (MIA) by injection of polyriboinosinic-polyribocytidilic acid (polyI:C) is known to precipitate a wide spectrum of behavioral, cognitive, and pharmacological abnormalities in adult offspring. PolyI:C leads to the pronounced production of pro-inflammatory cytokines. Specifically, the relative expression of cytokines in the fetal brains in response to maternal immune challenge may be an indirect mechanism by which MIA can alter fetal development. Our previous findings suggested that PolyI:C exposed earliest in gestation caused extensive deficit of integrity of fronto-striatallimbic circuits. Also, the early but not late prenatal immune challenge disrupts sensorimotor gating in adulthood in our study. In the present study, PolyI:C challenge on the early and late gestation was used as animal model of schizophrenia and immune responses in pregnant mice were assessed. In addition, locomotor activity, fear conditioning and pharmacological responses were evaluated in their adult offspring which relate with the different phenotypes in schizophrenia. METHODS: Pregnant mice were treated with saline or PolyI:C (5mg/kg, vol. of injection 5ml/kg) at gestation day 9 and day 17. Levels of inflammatory cytokines (interleukin 6: IL 6, IL 10, and tumor necrosis factor α: TNFα) were measured in serum of pregnant mice after 1hr PolyI:C challenge. The mice of adult offspring (CON=10, GD9 PolyIC=4, GD17 PolyIC=6) were injected with saline and returned to the open field for 30 min. Then, they were injected with D-amphetamine before being returned back to the open field for 90 min. Fear conditioning protocol: On the training day, mice (GD9 SAL=7, GD9 PolyIC=10; GD17 SAL+GD9 SAL=8, GD17 PolyIC=6) were placed into conditioning chamber for 6 min habituation, followed by 3 paired clicker (CS, 30 sec, 4Hz, 80 dB) and footshock (US, 2 sec, 0.5mA). After the final clicker/shock pairing in the chamber, mice continually stayed in the chamber for the extra 2 mins. Then context and cued test were measured after training for 24 hr and 48 hr. RESULTS: After 1hr exposure to PolyI:C markedly increased the serum protein levels of IL-6, IL-10 and TNF α in both gestation day condition compared to saline injection. One-way ANOVA showed a significant group difference in cytokine protein levels: IL 6: F(2,9)=6.254, p<0.05; IL 10: F(2,9)=51.430, p<0.0001; TNFα: F(2,9)=5.107, p<0.05. Post hoc comparisons were conducted showed that IL6 level in GD9 showed significant difference compared to control, TNFα level in GD17 showed significant higher compared to control, IL10 level showed significant increased in both GD9 and GD17 compared to control. The offspring of GD9 showed significant hyperactivity compared to control after saline injection, p<0.0001. Both GD9 and GD17 expressed the hypersensitive to amphetamine challenge compared to control: GD9, p<0.0001; GD17, p<0.05. Interestingly, GD9 MIA mice showed normal fear learning and memory. However, GD17 showed deficit of context test which is sensitive to hippocampal function. DISCUSSION: Present studies show that the time of MIA critically determines the pattern of behavioral abnormalities which may be indirectly caused by cytokine responses. PolyIC injection on GD9 increased locomotor activities and induced more sensitivity to amphetamine challenge which may relate with prenatal IL 6 immune response. GD17 but not GD9 showed deficit of context dependent fear memory.The 3rd Biennial Conference of the Schizophrenia International Research Society (SIRS), Florence, Italy, 14-18 April 2012. In Schizophrenia Research, 2012, v. 136 suppl. 1, p. S191-S192, poster no. 2

Can prenatal supplementation of Omega-3 prevent the early prodrome of schizophrenia in adolescence in a mouse model?

Poster no. 174Link_to_subscribed_fulltex

Gender-dependent differences in the neural responses to fear acquisition: a voxel-based Diffusion Tensor Imaging (DTI) Study

Poster no. 2

X-linked tspyi2deficit mouse is associated with a phenotype of schizophrenia

Poster no. 19Link_to_subscribed_fulltex

Altered protein expression of rat prefrontal cortex following perinatal asphyxia: implications of schizophrenia and autism

Poster Presentation - 03 PTM II: Glycosylation, Glycation, Oxidation: no. POS-03-088The Conference program's website is located at http://www.hupo.org/2013/contents/program.htm