On the indistinguishability of Raman photons

We provide a theoretical framework to study the effect of dephasing on the quantum indistinguishability of single photons emitted from a coherently driven cavity QED $\Lambda$-system. We show that with a large excited-state detuning, the photon indistinguishability can be drastically improved provided that the fluctuation rate of the noise source affecting the excited state is fast compared with the photon emission rate. In some cases a spectral filter is required to realize this improvement, but the cost in efficiency can be made small.Comment: 18 pages, 3 figures, final versio

Flat Dielectric Grating Reflectors with High Focusing Power

Sub-wavelength dielectric gratings (SWG) have emerged recently as a promising alternative to distributed-Bragg-reflection (DBR) dielectric stacks for broadband, high-reflectivity filtering applications. A SWG structure composed of a single dielectric layer with the appropriate patterning can sometimes perform as well as thirty or forty dielectric DBR layers, while providing new functionalities such as polarization control and near-field amplification. In this paper, we introduce a remarkable property of grating mirrors that cannot be realized by their DBR counterpart: we show that a non-periodic patterning of the grating surface can give full control over the phase front of reflected light while maintaining a high reflectivity. This new feature of dielectric gratings could have a substantial impact on a number of applications that depend on low-cost, compact optical components, from laser cavities to CD/DVD read/write heads.Comment: submitted to Nature Photonic

Orthogonal translation enables heterologous ribosome engineering in E. coli

The ribosome represents a promising avenue for synthetic biology, but its complexity and essentiality have hindered significant engineering efforts. Heterologous ribosomes, comprising rRNAs and r-proteins derived from different microorganisms, may offer opportunities for novel translational functions. Such heterologous ribosomes have previously been evaluated in E. coli via complementation of a genomic ribosome deficiency, but this method fails to guide the engineering of refractory ribosomes. Here, we implement orthogonal ribosome binding site (RBS):antiRBS pairs, in which engineered ribosomes are directed to researcher-defined transcripts, to inform requirements for heterologous ribosome functionality. We discover that optimized rRNA processing and supplementation with cognate r-proteins enhances heterologous ribosome function for rRNAs derived from organisms with ≥76.1% 16S rRNA identity to E. coli. Additionally, some heterologous ribosomes undergo reduced subunit exchange with E. coli-derived subunits. Cumulatively, this work provides a general framework for heterologous ribosome engineering in living cells

PENGEMBANGAN PROGRAM INTERVENSI DINI BERSUMBERDAYA KELUARGA PADA ANAK CEREBRAL PALSY DENGAN HAMBATAN KOMUNIKASI

Penelitian ini dilatarbelakangi oleh kurangnya pemahaman, penerimaan, dan sikap orang tua terhadap hambatan yang dihadapi anak. Hal ini berdampak pada kemampuan keluarga dalam memberikan layanan intervensi dini di rumah. Tujuan dari penelitian ini adalah untuk merumuskan program intervensi dini bersumber daya keluarga yang akan menjadi pedoman orang tua dalam melaksanakan intervensi. Penelitian ini menggunakan pendekatan kualitatif dengan metode deskriptif. Subjek dalam penelitian ini adalah satu keluarga yang memiliki anak Cerebral Palsy dengan hambatan komunikasi di Ciamis. Teknik pengumpulan data yang digunakan adalah observasi, wawancara, dan studi dokumentasi. Hasil penelitian menunjukkan bahwa: 1) anak memiliki hambatan komunikasi yang pencapaian perkembangan komunikasi verbalnya setara dengan anak usia 2-3 tahun dan usia kalender saat ini 5 tahun. 2) rendahnya tingkat pemahaman orangtua terhadap hambatan anak. 3). Rumusan program intervensi dini bersumber daya keluarga ini berdasarkan kondisi objektif serta kebutuhan keluarga dan anak. 4). tingkat pemahaman orang tua mengenai hambatan anak meningkat serta terjadi perubahan sikap dan perilaku orang tua kepada anak;--- The study was motivated by the lack of understanding, acceptance as well as the attitude of the parents toward their child’s obstacles. It somehow has an impact on family’s capacity to give early intervention support at home. This study was aimed at formulating an early intervention program to the child. The study used descriptive qualitative method involving a single family having a child suffering from Cerebral Palsy causing communication barrier at Ciamis. The techniques used in collecting the data were observations, interviews, and document analysis. The study revealed several findings as follows: 1) the child had communication barrier which made her communication verbal developmental stage was equal to 2-3 years old children. 2) The lack of understanding, acceptance and attitude of the parents toward their child’s communication barrier as well as the support in delivering early intervention at home. 3) The early intervention family-based program’s formulation was based on the objective condition as well as the needs’ of both the child and the parents. 4) The level understanding parents of the barriers to child increase and a change in attitudes and behavior of parents to child

Coherent Population Trapping of Single Spins in Diamond Under Optical Excitation

Coherent population trapping is demonstrated in single nitrogen-vacancy centers in diamond under optical excitation. For sufficient excitation power, the fluorescence intensity drops almost to the background level when the laser modulation frequency matches the 2.88 GHz splitting of the ground states. The results are well described theoretically by a four-level model, allowing the relative transition strengths to be determined for individual centers. The results show that all-optical control of single spins is possible in diamond.Comment: minor correction

A semiconductor source of triggered entangled photon pairs?

The realisation of a triggered entangled photon source will be of great importance in quantum information, including for quantum key distribution and quantum computation. We show here that: 1) the source reported in ``A semiconductor source of triggered entangled photon pairs''[1. Stevenson et al., Nature 439, 179 (2006)]} is not entangled; 2) the entanglement indicators used in Ref. 1 are inappropriate, relying on assumptions invalidated by their own data; and 3) even after simulating subtraction of the significant quantity of background noise, their source has insignificant entanglement.Comment: 5 pages in pre-print format, 1 tabl

Entanglement on mixed stabilizer states: normal forms and reduction procedures

Published versio

Quality and Safety Aspects of Infant Nutrition

Quality and safety aspects of infant nutrition are of key importance for child health, but oftentimes they do not get much attention by health care professionals whose interest tends to focus on functional benefits of early nutrition. Unbalanced diets and harmful food components induce particularly high risks for untoward effects in infants because of their rapid growth, high nutrient needs, and their typical dependence on only one or few foods during the first months of life. The concepts, standards and practices that relate to infant food quality and safety were discussed at a scientific workshop organized by the Child Health Foundation and the Early Nutrition Academy jointly with the European Society for Paediatric Gastroenterology, Hepatology and Nutrition, and a summary is provided here. The participants reviewed past and current issues on quality and safety, the role of different stakeholders, and recommendations to avert future issues. It was concluded that a high level of quality and safety is currently achieved, but this is no reason for complacency. The food industry carries the primary responsibility for the safety and suitability of their products, including the quality of composition, raw materials and production processes. Introduction of new or modified products should be preceded by a thorough science based review of suitability and safety by an independent authority. Food safety events should be managed on an international basis. Global collaboration of food producers, food-safety authorities, paediatricians and scientists is needed to efficiently exchange information and to best protect public health. Copyright (C) 2012 S. Karger AG, Base