Quantum key distribution with higher-order alphabets using spatially-encoded qudits

We propose and demonstrate a quantum key distribution scheme in higher-order $d$-dimensional alphabets using spatial degrees of freedom of photons. Our implementation allows for the transmission of 4.56 bits per sifted photon, while providing improved security: an intercept-resend attack on all photons would induce an error rate of 0.47. Using our system, it should be possible to send more than a byte of information per sifted photon.Comment: 4 pages, 5 figures. Replaced with published versio

Semi-quantitative analysis of bulk chondritic material using X-Ray fluorescence spectroscopy

73rd Annual Meeting of the Meteoritical-Society, New York, NY, July 26-30, 2010International audienceSynchrotron radiation X-ray fluorescence (SR-XRF) is a method of choice to analyze fragile, unique meteoritic samples, requiring no sample preparation. It is a nondestructive, multielemental, quantitative method, easily coupled to diffraction and speciation for a detailed sample characterization. The composition of samples thicker than a few microns is however difficult to obtain due to the high attenuation of the characteristic X-rays resulting in non-detection of low-Z elements (Z≤ 14)

Biodegradation and distribution of crude oil sampled at Fourchon Beach

This study was developed to determine the distribution and fate of crude oil spilled from the Deepwater Horizon oil rig starting on April 24, 2010. Crude oil from this spill contaminated portions of Fourchon Beach, Louisiana which was the study site for this thesis. Understanding the fate processes that affect crude oil once it’s released is important because the compounds that comprise oil can be hazardous to humans and wildlife. Composite and small surface residual ball (SSRB) samples were collected from the supratidal zone of Fourchon Beach and analyzed for PAHs and alkanes. Alkane concentrations decreased significantly over time, while PAH concentrations demonstrated little to no signs of degradation. High dynamic resolution images of the sampling areas from the supratidal zone were analyzed for distribution of oil using advanced image processing and 16 of the 36 sampling areas had a 1% or greater coverage of oil. The oil coverage data based on image analysis was tested for statistical normality, log normality, and gamma distribution. The data failed both the normality and log normality tests, but passed the gamma distribution test resulting in a mean of 3.2% and 0.6% and standard error of 1.1% and 0.2% in Zones 3 and 2 respectively. SSRB, buried oil, and tarball samples were collected from the intertidal zone of Fourchon Beach. SSRB concentrations from the intertidal zone showed minor decrease over 4 months of sampling. However, total PAHs and total alkanes in SSRBs from intertidal zone were significantly lower when compared against SSRBs in the supratidal zone. Buried oil samples collected closest to the shoreline and those taken on the later sampling dates had a lower concentration of PAHs and alkanes than those collected at earlier sampling dates and further away from the shoreline. Tarball samples collected in the intertidal zone demonstrated decreasing concentrations of PAHs and alkanes over the course of the sampling dates. These results indicate that degradation of crude oil at Fourchon Beach is occurring, but future sampling needs to occur at Fourchon Beach to determine the long term impacts of the oil deposited there

Implications of in situ calcification for photosynthesis in a ~3.3 Ga-old microbial biofilm from the Barberton greenstone belt, South Africa

International audienceTiming the appearance of photosynthetic microorganisms is crucial to understanding the evolution of life on Earth. The ability of the biosphere to use sunlight as a source of energy (photoautotrophy) would have been essential for increasing biomass and for increasing the biogeochemical capacity of all prokaryotes across the range of redox reactions that support life. Typical proxies for photosynthesis in the rock record include features, such as a mat-like, laminated morphology (stratiform, domical, conical) often associated with bulk geochemical signatures, such as calcification, and a fractionated carbon isotope signature. However, to date, in situ, calcification related to photosynthesis has not been demonstrated in the oldest known microbial mats. We here use in situ nanometer-scale techniques to investigate the structural and compositional architecture in a 3.3 billion-year (Ga) old microbial biofilm from the Barberton greenstone belt, thus documenting in situ calcification that was most likely related to anoxygenic photosynthesis. The Josefsdal Chert Microbial Biofilm (JCMB) formed in a littoral (photic) environment. It is characterised by a distinct vertical structural and compositional organisation. The lower part is calcified in situ by aragonite, progressing upwards into uncalcified kerogen characterised by up to 1% sulphur, followed by an upper layer that contains intact filaments at the surface. Crystallites of pseudomorphed pyrite are also associated with the biofilm suggesting calcification related to the activity of heterotrophic sulphur reducing bacteria. In this anoxygenic, nutrient-limited environment, the carbon required by the sulphur reducing bacteria could only have been produced by photoautotrophy. We conclude that the Josfsdal Chert Microbial Biofilm was formed by a consortium of anoxygenic microorganisms, including photosynthesisers and sulphur reducing bacteria

State business: gender, sex and marriage in Tajikistan

This article examines the relation of the state to masculinity and sexuality by way of an exploration of the sexual problems of a young man and his wife in Tajikistan at the end of the Soviet era. It suggests that the regime’s inattention to this kind of issue was bound up with the importance to the state of projecting appropriate versions of masculinity. It further posits the idea that the continued refusal of the independent Tajik state to offer appropriate treatments for sexual dysfunction is consistent with the image of modernity President Rahmon wishes to present to the world. The article shows that as masculinity discursively occupies the superior gender position, with men expected to dominate, the state is itself impotent to respond when they are, in fact, unable to do so in sexual practice. However, the myth of male dominance persists to the point that it may prevent women from seeing beyond their subordination and finding mutually beneficial solutions in their familial and sexual relationships

Is assertive community treatment coercive?

Background: Assertive community treatment (ACT) has become one of the cornerstones of care for people with serious mental illnesses. ACT is usually conceptualized as incorporating a multidisciplinary team approach, active and persistent attempts to engage clients, direct provision of comprehensive health and social care, and in-vivo and out-of-hours working. In addition, the service is ongoing, not time-limited, and has a low practitioner-to-client ratio (usually 1:10). However, ACT is not without its critics, many of them focused on the use of "coercive" techniques with ACT patients 12. At one end of the spectrum are those opponents of ACT who contend, "ACT is largely a euphemistic label for coercion." Despite substantial interest in the coercive aspects of ACT, no studies have focused specifically on understanding the phenomenology of the use and experience of leverage in ACT. Methods: Staff and patients of 4 ACT teams in Manhattan were recruited to participate in focus groups exploring their experiences with and opinions about the use of leverage in ACT. A total of 21 patients and 24 staff members participated with group size ranging from 10 to 12 members. Results: With only one exception, patients said uniformly that they did not believe that their ACT team was coercive or went too far in pressuring them to comply with treatment. ACT staff seemed more aware of the dangers of engaging in coercive behavior. Hence, they indicated a need to "keep each other in check." Conclusion: This preliminary series of focus groups with patients and staff members of ACT programs revealed little evidence from either set of participants of significant use of leverage or perceptions of coercion. Instead both patients and staff reported that supporting patients and building relationships with them were the preferred mechanisms for promoting treatment goals. This study suggests that ACT is not an intrinsically coercive model for the delivery of mental health services

Esophageal atresia: data from a national cohort

PURPOSE: A prospective national register was established in 2008 to record all new cases of live-birth newborns with esophageal atresia (EA). This epidemiological survey was recommended as part of a national rare diseases plan. METHODS: All 38 national centers treating EA participated by completing for each patient at first discharge a questionnaire validated by a national committee of experts. Data were centralized by the national reference center for esophageal anomalies. Quantitative and qualitative analyses were performed, with P-values of less than 0.05 considered statistically significant. Results of the 2008-2009 data collection are presented in this report. RESULTS: Three hundred seven new living cases of EA were recorded between January 1, 2008, and December 31, 2009. The male/female sex ratio was 1.3, and the live-birth prevalence of EA was 1.8 per 10,000 births. Major characteristics were comparable to those reported in the literature. Survival was 95%, and no correlation with caseload was noted. CONCLUSIONS: Epidemiologic surveys of congenital anomalies such as EA, which is a rare disease, provide valuable data for public health authorities and fulfill one important mission of reference centers. When compared with previous epidemiological data, this national population-based registry suggests that the incidence of EA remains stable