Sub-pm/Hz\mathrm{\mathbf{\sqrt{\rm Hz}}} non-reciprocal noise in the LISA backlink fiber

The future space-based gravitational wave detector Laser Interferometer Space Antenna (LISA) requires bidirectional exchange of light between its two optical benches on board of each of its three satellites. The current baseline foresees a polarization-maintaining single-mode fiber for this backlink connection. Phase changes which are common in both directions do not enter the science measurement, but differential ("non-reciprocal") phase fluctuations directly do and must thus be guaranteed to be small enough. We have built a setup consisting of a Zerodur$^{\rm TM}$ baseplate with fused silica components attached to it using hydroxide-catalysis bonding and demonstrated the reciprocity of a polarization-maintaining single-mode fiber at the 1 pm/$\sqrt{\textrm{Hz}}$ level as is required for LISA. We used balanced detection to reduce the influence of parasitic optical beams on the reciprocity measurement and a fiber length stabilization to avoid nonlinear effects in our phase measurement system (phase meter). For LISA, a different phase meter is planned to be used that does not show this nonlinearity. We corrected the influence of beam angle changes and temperature changes on the reciprocity measurement in post-processing

Measurement of the non-reciprocal phase noise of a polarization maintaining single-mode optical fiber

Polarization maintaining single-mode optical fibers are key components in the interferometry of the Laser Interferometer Space Antenna (LISA). LISA's measurement principle relies on the availability of space qualified fibers of this type which influence the phase of light with a wavelength of 1064 nm passing in opposite directions through them with differences smaller than 6 prad/. We present a measurement scheme suitable to sense these non-reciprocal phase changes, as well as results obtained using this setup on samples of commercially available fibers. The experimental setup for the fiber characterization consists of a quasi-monolithic interferometer which constitutes a representative cut-out of the local interferometry on-board LISA concerning the fiber. Several noise sources are identified and improvements to the setup are presented to overcome them. The noise level achieved using this setup is between approximately 40 prad/ and 400 prad/ in the frequency range between 1 mHz and 1 Hz. It is also verified that this noise level is limited by the setup and not introduced by the fiber.DLR/50 OQ 060

The end-to-end testbed of the Optical Metrology System on-board LISA Pathfinder

LISA Pathfinder is a technology demonstration mission for the Laser Interferometer Space Antenna (LISA). The main experiment on-board LISA Pathfinder is the so-called LISA Technology Package (LTP) which has the aim to measure the differential acceleration between two free-falling test masses with an accuracy of 3x10^(-14) ms^(-2)/sqrt[Hz] between 1 mHz and 30 mHz. This measurement is performed interferometrically by the Optical Metrology System (OMS) on-board LISA Pathfinder. In this paper we present the development of an experimental end-to-end testbed of the entire OMS. It includes the interferometer and its sub-units, the interferometer back-end which is a phasemeter and the processing of the phasemeter output data. Furthermore, 3-axes piezo actuated mirrors are used instead of the free-falling test masses for the characterisation of the dynamic behaviour of the system and some parts of the Drag-free and Attitude Control System (DFACS) which controls the test masses and the satellite. The end-to-end testbed includes all parts of the LTP that can reasonably be tested on earth without free-falling test masses. At its present status it consists mainly of breadboard components. Some of those have already been replaced by Engineering Models of the LTP experiment. In the next steps, further Engineering Models and Flight Models will also be inserted in this testbed and tested against well characterised breadboard components. The presented testbed is an important reference for the unit tests and can also be used for validation of the on-board experiment during the mission

CURRENT GENETIC COUNSELING PRACTICE FOLLOWING POSITIVE NON-INVASIVE PRENATAL TESTING FOR SEX CHROMOSOME ABNORMALITIES

The purpose of this study was to describe current prenatal and pediatric genetic counseling practice following a non-invasive prenatal testing (NIPT) result positive for a sex chromosome abnormality (SCA). The positive predictive value for SCA with NIPT is lower than seen for Trisomy 21 due to natural loss of the X chromosome from maternal cells during aging, confined placental mosaicism, and undiagnosed maternal sex chromosome abnormality. Except for 45,X, individuals with SCA usually have no ultrasound or postnatal findings. This makes follow-up for unresolved positive NIPT necessary; however, there are currently no clinical guidelines. This study used a prospective anonymous questionnaire to survey 176 prenatal and pediatric genetic counselors. Greater than 70% of pediatric respondents and \u3e80% of prenatal respondents were somewhat or extremely comfortable counseling patients about SCAs. However, prenatal respondents in the field for45,X (p88%) and anatomy ultrasound (~90%), but the percent consistently offering maternal karyotype (22-52%) and postnatal evaluation (28-87%) varied. Maternal karyotype was offered more often when NIPT was positive for 45,X or 47,XXX and patients had normal diagnostic testing (p72%) but the percent offering maternal karyotype (6-46%) varied widely. With the current inconsistencies, many newborns with undiagnosed SCAs who could benefit from growth hormone therapy, early intervention, and/or targeted surveillance may be missed. There is a need for professional guidelines to help improve clinical care for patients with NIPT results positive for SCAs

Density Properties of Sets

Dr. H. L. Smith in a paper which has not been published as yet 3hows that by starting with a general function satisfying Caratheoacry\u27s first two postulates on an outer measure function, it is possible to construct a function which satisfies all four postulates. In this dissertation we have stuuied some of the characteristics o of this.function, principally those which are of use in deriving our‘theorems on density. We have set up three general density functions, and nave succeeded in showing- tnat for the most general of these, it is true thac the Smith measure of the set at which the upper density is less tnan 1, and the one at which the lower density is greater than 1, is zero. We have also established tnat under certain circumstances there is a definite relation between this function and the density function defined by Besicovitch. Considerable attention nas been devotee to certain fundamental geometric theorems, which have led us to a generalized form of tne Vitali tneorem. We have also uerived a set of sufficient conditions for the validity of this theorem, including the one for the Smith function

Interferometry for a space-based gravitational wave observatory : reciprocity of an optical fiber

[no abstract

Energetic efficiency of infant formulae: a review

Breast-fed and formula-fed infants differ in terms of nutrient intake, growth, and metabolic and endocrine responses. The energetic efficiency, i.e. the weight or length gain per 100 kcal of energy intake, of breast-fed infants is about 11% higher than the energetic efficiency of formula-fed infants. Only limited data is available on the influence of formula composition on the energetic efficiency of infant formulae. We conducted a review of controlled trials to identify the impact of the macronutrient composition of infant formulae on energetic efficiency. An electronic literature search was conducted in February 2014. Intervention trials that investigated the effect of an infant formula with a modified macronutrient composition and reported the weight, length, and nutritional intake of apparently healthy, term, fully formula-fed infants with a normal weight were included. Thirteen trials met the inclusion criteria. The results showed no effect of the total content of energy, carbohydrate, protein, or fat on energetic efficiency. In contrast, small increasing effects of higher glycemic carbohydrates on energetic efficiency were identified. Improved fat absorption via the use of palmitic acid at the sn-2 ester position of triacylglycerol increased the energetic efficiency by 11%. The quality of formula protein, specifically an increased whey-to-casein ratio, an increased α-lactalbumin content, or a higher tryptophan content increased the energetic efficiency by about 13%. We conclude that fat absorption and protein quality have the potential to modulate energetic efficiency and may contribute to the observed differences in growth and metabolism between breast-fed and formula-fed infants.</jats:p

Phospholipid Species in Newborn and 4 Month Old Infants after Consumption of Different Formulas or Breast Milk

INTRODUCTION:Arachidonic acid (AA) and docosahexaenoic acid (DHA) are important long-chain polyunsaturated fatty acids for neuronal and cognitive development and are ingredients of infant formulae that are recommended but there is no evidence based minimal supplementation level available. The aim of this analysis was to investigate the effect of supplemented AA and DHA on phospholipid metabolism. METHODS:Plasma samples of a randomized, double-blind infant feeding trial were used for the analyses of phospholipid species by flow-injection mass spectrometry. Healthy term infants consumed isoenergetic formulae (intervention formula with equal amounts of AA and DHA-IF, control formula without additional AA and DHA-CF) from the first month of life until the age of 120 days. A group of breast milk (BM) -fed infants was followed as a reference. RESULTS:The plasma profile detected in newborns was different from 4 month old infants, irrespective of study group. Most relevant changes were seen in higher level of LPC16:1, LPC20:4, PC32:1, PC34:1 and PC36:4 and lower level of LPC18:0, LPC18:2, PC32:2, PC36:2 and several ether-linked phosphatidylcholines in newborns. The sum of all AA and DHA species at 4 month old infants in the CF group showed level of 40% (AA) and 51% (DHA) of newborns. The supplemented amount of DHA resulted in phospholipid level comparable to BM infants, but AA phospholipids were lower than in BM infants. Interestingly, relative contribution of DHA was higher in ether-linked phosphatidylcholines in CF fed infants, but IF and BM fed infants showed higher overall ether-linked phosphatidylcholines levels. CONCLUSION:In conclusion, we have shown that infant plasma phospholipid profile changes remarkably from newborn over time and is dependent on the dietary fatty acid composition. A supplementation of an infant formula with AA and DHA resulted in increased related phospholipid species