Photon echo without a free induction decay in a double-Lambda system

We have characterized a novel photon-echo pulse sequence for a double-$\Lambda$ type energy level system where the input and rephasing transitions are different to the applied $\pi$-pulses. We show that despite having imperfect $\pi$-pulses (associated with large coherent emission due to free induction decay), the noise added is only 0.019$\pm$0.001 relative to the shot noise in the spectral mode of the echo. Using this echo pulse sequence in the `rephased amplified spontaneous emission' (RASE) scheme \cite{Ledingham2010} will allow for generation of entangled photon pairs that are in different frequency, temporal, and potentially spatial modes to any bright driving fields. The coherence and efficiency properties of this sequence were characterized in a Pr:YSO crystal

Non-classical photon streams using rephased amplified spontaneous emission

We present a fully quantum mechanical treatment of optically rephased photon echoes. These echoes exhibit noise due to amplified spontaneous emission, however this noise can be seen as a consequence of the entanglement between the atoms and the output light. With a rephasing pulse one can get an "echo" of the amplified spontaneous emission, leading to light with nonclassical correlations at points separated in time, which is of interest in the context of building wide bandwidth quantum repeaters. We also suggest a wideband version of DLCZ protocol based on the same ideas.Comment: 5 pages, 4 figures. Added section

Perancangan Daur Ulang Cd Bekas Menjadi Produk Baru Beserta Media Promosinya

Jaman sekarang CD mulai tidak dibutuhkan lagi oleh masyarakat karena ukuran CD yang cukup besar dan kapasitas file yang terlalu kecil. Masyarakat cenderung memilih flashdisk daripada CD karena ukuran kecil tetapi kapasitas file yang lebih besar. Hal ini menyebabkan CD dibuang sia-sia dan menambah pencemaran sampah. Daur ulang merupakan salah satu cara untuk mengatasi permasalahan tersebut. CD bekas dapat didesain dan dibuat menjadi suatu karya yang lebih berguna dan menarik, seperti hiasan-hiasan interior yang terlihat berkelas dan minimalis

Integrating local knowledge and forest surveys to assess Lantana camara impacts on indigenous species recruitment in Mazeppa Bay, South Africa

Invasive alien species have variable impacts on peoples’ livelihoods, plant communities and species at the local scale. Local people often have deeper insights into and experiences of these impacts than can be measured by scientific surveys. Here we examine the impacts of Lantana camara on the recruitment of indigenous forest species, many of which are used by local people. We integrate findings from conversations with elderly respondents with standard ecological surveys. Both sources of information indicate that the increasing presence of Lantana suppresses the number and species richness of recruits of indigenous forest species, which may retard forest succession. Dense thickets of Lantana also restricted access to non-timber forest products and species of cultural significance. The origin and date of the Lantana introduction in the area was identified by respondents as the 1960s and it escaped into the wild in the early 1970s. These findings can be incorporated into locally based management considerations

Experimental realization of light with time separated correlations by rephasing amplified spontaneous emission

Amplified spontaneous emission is a common noise source in active optical systems, it is generally seen as being an incoherent process. Here we excite an ensemble of rare earth ion dopants in a solid with a {\pi}-pulse, resulting in amplified spontaneous emission. The application of a second {\pi}-pulse leads to a coherent echo of the amplified spontaneous emission that is correlated in both amplitude and phase. For small optical thicknesses, we see evidence that the amplified spontaneous emission and its echo are entangled.Comment: 6 pages, 5 figures, the supplementary information pdf was uploaded with latex source files. This version accepted for publication in PR

Primate-specific evolution of noncoding element insertion into PLA2G4C and human preterm birth

Background The onset of birth in humans, like other apes, differs from non-primate mammals in its endocrine physiology. We hypothesize that higher primate-specific gene evolution may lead to these differences and target genes involved in human preterm birth, an area of global health significance. Methods We performed a comparative genomics screen of highly conserved noncoding elements and identified PLA2G4C, a phospholipase A isoform involved in prostaglandin biosynthesis as human accelerated. To examine whether this gene demonstrating primate-specific evolution was associated with birth timing, we genotyped and analyzed 8 common single nucleotide polymorphisms (SNPs) in PLA2G4C in US Hispanic (n = 73 preterm, 292 control), US White (n = 147 preterm, 157 control) and US Black (n = 79 preterm, 166 control) mothers. Results Detailed structural and phylogenic analysis of PLA2G4C suggested a short genomic element within the gene duplicated from a paralogous highly conserved element on chromosome 1 specifically in primates. SNPs rs8110925 and rs2307276 in US Hispanics and rs11564620 in US Whites were significant after correcting for multiple tests (p < 0.006). Additionally, rs11564620 (Thr360Pro) was associated with increased metabolite levels of the prostaglandin thromboxane in healthy individuals (p = 0.02), suggesting this variant may affect PLA2G4C activity. Conclusions Our findings suggest that variation in PLA2G4C may influence preterm birth risk by increasing levels of prostaglandins, which are known to regulate labor.Children’s Discovery InstituteMarch of Dimes Birth Defects FoundationNational Institute of General Medical Sciences (U.S.) (grant T32 GM081739)Washington University (Saint Louis, Mo.) (Mr. and Mrs. Spencer T. Olin Fellowship for Women in Graduate Study)Sigrid Jusélius FoundationSigne and Anne Gyllenberg FoundationAcademy of FinlandVanderbilt University (Turner-Hazinski grant award

Portal vein thrombosis associated with psoriasis: a case report

BACKGROUND: Psoriasis is no longer viewed as an isolated dermatological ailment and instead is considered a systemic disease. The extension of this spectrum has heightened the known risk of morbidity and mortality due to the involvement of cardiovascular system and the risk of venous thrombosis. A number of cases have reported the increased occurrence of deep vein thrombosis and pulmonary embolism in the background of psoriasis, however portal vein thrombosis has not been reported to date. We report an index case of chronic portal vein thrombosis in a diagnosed patient with psoriasis. CASE PRESENTATION: A 67-year-old South-Asian female previously diagnosed and treated for psoriasis presented with a four month history of abdominal pain associated with abdominal distension. Clinical examination revealed an enlarged spleen and free fluid in the abdomen. Imaging with ultrasonography and computed tomography of the abdomen revealed features compatible with chronic portal vein thrombosis with cavernous transformation. CONCLUSION: This case highlights the importance of having clinical awareness of occurrence of thrombosis in patients with psoriasis. Typical symptoms favoring thrombosis should prompt thorough investigation to exclude this rare yet possible complication in patients with psoriasis, including that of portal vein thrombosis. Prophylaxis with anticoagulation still lacks strength of evidence to be justified in psoriasis. The exact pathogenesis of venous thromboembolism in psoriasis is still unexplained and further studies are needed to clarify the causal association

Devising a Responsible Framework for Air Quality Sensor Placement

A major challenge faced when developing smart, sustainable urban environments is the reduction of air pollutants that adversely impact citizens' health. The UK has implemented strategies such as clean air zones (CAZs) coupled with the use of sensor technologies to monitor the changes in these pollutant concentrations while simultaneously reducing them over time. Consequently, this poses important concerns: how much consideration has been given to the positioning of these sensors, and are the citizens the focal point of this decision-making process? In this paper, we seek to address these concerns by introducing a framework which responsibly positions air pollution sensors based on three conjoined tenets: 1) sensors should equitably cover areas of varying deprivations faced by citizens, 2) sensors should cover areas that have dense concentrations of specified parameters of interest which directly impact its citizens' health, behavioural practices and other factors, and 3) sensor coverage should be maximised across the expanse of the city. After laying the foundation of our algorithm, we then demonstrate that sensors can be positioned in a responsible manner that upholds the aforementioned objectives using geospatial data for the city of Hull, one of the most deprived areas of England