Frequency-Dependent Squeezed Vacuum Source for the Advanced Virgo Gravitational-Wave Detector.

In this Letter, we present the design and performance of the frequency-dependent squeezed vacuum source that will be used for the broadband quantum noise reduction of the Advanced Virgo Plus gravitational-wave detector in the upcoming observation run. The frequency-dependent squeezed field is generated by a phase rotation of a frequency-independent squeezed state through a 285 m long, high-finesse, near-detuned optical resonator. With about 8.5 dB of generated squeezing, up to 5.6 dB of quantum noise suppression has been measured at high frequency while close to the filter cavity resonance frequency, the intracavity losses limit this value to about 2 dB. Frequency-dependent squeezing is produced with a rotation frequency stability of about 6 Hz rms, which is maintained over the long term. The achieved results fulfill the frequency dependent squeezed vacuum source requirements for Advanced Virgo Plus. With the current squeezing source, considering also the estimated squeezing degradation induced by the interferometer, we expect a reduction of the quantum shot noise and radiation pressure noise of up to 4.5 dB and 2 dB, respectively.

A rare case of collodion baby with ophthalmic involvement.

BACKGROUND: Ichthyosis is an infrequent clinical entity worldwide (1:300,000 births). When diagnosed in a newborn, two forms can be identified: collodion baby and its most severe form, harlequin fetus or maligna keratoma. In both cases, clinical manifestations are thick and hard skin with deep splits. The splits are more prominent in the flexion areas. CASE: We report a case of a 4- day-old baby who was referred to JNMC Eye OPD by the Pediatric Department of the JNMC. He was having severe bilateral ectropion of the upper lids and chemosis of conjuntiva, without corneal involvement. There was distortion of the pinna and peeling of the skin, more over the chest around the neck region and over the flexor aspect of limbs. CONCLUSION: Management of collodion baby requires a multi-disciplinary approach.

Presbyopia and its anatomical and physiological variants.

AIM: To study the various ocular anatomical and physiological parameters in presbyopia. MATERIALS AND METHODS: We studied the various ocular anatomical and physiological parameters like corneal curvature (keratometry readings: K1 and K2), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and axial length (AL) in 100 presbyopic patients between 35 - 55 years of age. The patients were divided into two age groups: I (35 ± 44 years) and II (45-55 yrs). ACD, AL and LT were measured using an Ascan. CCT was measured with ultrasonic pachymetry. RESULTS: The CCT decreased (BE), LT increased and ACD decreased (RE) significantly with increasing age (p less than 0.05). There was no significant difference in males and females. Nearly 3/4th of the total increase in lens thickness was responsible for the decrease in the anterior chamber depth and the rest, 1/4th , goes posteriorly. Corneal curvature and AL showed no significant change with age. CONCLUSIONS: The mean of CCT decreased significantly with advancing age. As age increased, the mean value of lens thickness increased and anterior chamber depth decreased. Nearly 3/4th of total increase in LT was anteriorly, decreasing the ACD. Corneal curvature and AL has no relation with age.

Accommodation: its relation to refractive errors, amblyopia and biometric parameters.

AIM: To study accommodation in relation to different refractive errors, amblyopia and to measure the anatomical changes in the accommodating eye MATERIALS AND METHODS: We studied the amplitude of accommodation (AA) in 150 patients in the age group 11 ± 30 years which included emmetropes, myopes, hypermetropes and hypermetropic amblyopes using the Royal Air Force (RAF) rule. The anterior chamber depth (ACD), axial length (AxL) and lens thickness (LT) changes during accommodation were measured using an A-scan. Myopes and hypermetropes were further divided based on the amount of refractive error : less than 2D, 2 -4D and greater than 4D. RESULTS: Corrected low myopes had the highest accommodation amplitude (p less than 0.05) followed by emmetropes. Corrected hypermetropes were found to have the lowest amplitude of accommodation (p less than 0.05). The amblyopic eye had a significantly low AA compared to the non-amblyopic eye (p less than 0.05). ACD decreased (p less than 0.05) and LT increased (p less than 0.05) during accommodation. The AxL increase was maximum in myopes (p less than 0.05) followed by hypermetropes but the change was not significant in hypermetropes (p greater than 0.05). CONCLUSION: The amblyopic eye has low amplitudes of accommodation proving the benefit of near adds in amblyopic patients. Prolonged near work might induce myopia in susceptible eyes by increasing the axial length.

HLA and bone marrow transplant donor search strategies.

Searching for a family donor other than an HLA identical sibling can be successful. The chance of finding an identical or one antigen mismatched family donor can be calculated with a computer program, so this may help in the decision making whether to perform extended family typing or not. Extended family donors are often better matched rather than unrelated donors. The reason is that they have at least one haplotype genetically identical to the patient, and that there may be some higher match grade for the minor histocompatibility antigens. Sometimes extended family donor could be the only donor for the patient. Ethical considerations have to be taken into account and extended family donors should be volunteer donors.

Effect of centrally administered insulin on blood glucose levels in dogs.

The effects of minimal doses of insulin administered by intracerebroventricular (ICV) and intracisternal (IC) routes in mongrel dogs, on peripheral blood glucose level (BGL) have been studied. The dose of 0.1 U of insulin was found to be the minimal dose. This dose produced an immediate short lived hyperglycaemia followed by a marked and sustained hypoglycaemia. Both the effects were not observed in spinal cord transected-vagosympathectomised animals. The immediate hyperglycaemic effect was not observed in adrenalectomised animals whereas the subsequent hypoglycaemic effect did not appear only when the liver was removed. In an attempt to identify the precise site of action in the central nervous system (CNS), The cerebellomedullary angles were found to be the most sensitive sites for the action of locally applied insulin. It is suggested that insulin on central administration causes a rise in the BGL by an action on the adrenal glands and subsequently causes a marked fall in BGL by an action on the liver through some nerve fibers.