75%-efficiency blue generation from an intracavity PPKTP frequency doubler

We report on a high-efficiency 461 nm blue light conversion from an external cavity-enhanced second-harmonic generation of a 922 nm diode laser with a quasi-phase-matched KTP crystal (PPKTP). By choosing a long crystal (LC=20 mm) and twice looser focusing (w0=43 $\mu$m) than the "optimal" one, thermal lensing effects due to the blue power absorption are minimized while still maintaining near-optimal conversion efficiency. A stable blue power of 234 mW with a net conversion efficiency of eta=75% at an input mode-matched power of 310 mW is obtained. The intra-cavity measurements of the conversion efficiency and temperature tuning bandwidth yield an accurate value d33(461 nm)=15 pm/V for KTP and provide a stringent validation of some recently published linear and thermo-optic dispersion data of KTP

Comparison of insulin detemir and insulin glargine in a Basal-Bolus regimen, with insulin aspart as the mealtime insulin, in patients with type 1 diabetes: A 52-week, multinational, randomized, open-label, parallel-group, treat-to-target noninferiority trial

Objective: The primary study objective was to determine whether insulin detemir (detemir) was noninferior to insulin glargine (glargine) as the basal insulin in a basal-bolus regimen, with insulin aspart as the mealtime insulin, in terms of glycemic control at the end of 52 weeks in patients with type I diabetes mellitus (T1DM). Methods: This multinational, open-label, parallel-group, treat-to-target, noninferiority trial enrolled patients aged >= 18 years who had had T1DM for at least 12 months, had been taking a basal-bolus insulin regimen for at least 3 months, and had a glycosylated hemoglobin (HbA(1c)) value <= 11.0% at screening. Patients were randomized in a 2:1 ratio to receive either detemir or glargine for 52 weeks. The basal insulin was initially administered once daily (in the evening) in both groups; if patients in the detemir group were achieving the plasma glucose (PG) target before breakfast but not before dinner, they were switched to twice-daily administration. Glargine was administered once daily throughout the trial, according to its approved labeling. Each patient attended 13 study visits and received 16 scheduled telephone calls from the trial site. The primary efficacy end point was glycemic control (HbA(1c)) after 52 weeks of treatment. Secondary end points included the number of patients achieving an HbAlc value <= 7.0%, with or without a major hypoglycemic episode in the last month of treatment; fasting PG (FPG); within-patient variation in self-monitored plasma glucose (SMPG) before breakfast and dinner; and 10-point SMPG profiles. The noninferiority margin was 0.4%, consistent with US Food and Drug Administration guidelines. Results: Four hundred forty-three patients (mean [SD] age, 42 [12] years; body mass index, 26.5 [4.0] kg/m(2); duration of diabetes, 17.2 [11.4] years; HbA(1c), 8.1% [1.1%]) received study treatment. After 52 weeks, the estimated mean HbA(1c) did not differ significantly between the detemir and glargine groups (7.57% and 7.56%, respectively; mean difference, 0.01%; 95% CI -0.13 to 0.16), consistent with the noninferiority of detemir to glargine. The corresponding estimated changes in HbA(1c) were -0.53% and -0.54%. In the 90 patients who completed the trial on once-dally detemir and the 173 patients who completed the trial on twice-daily detemir, the estimated changes in HbA(1c) were-0.49% and -0.58%, respectively. After 52 weeks, there were no significant differences in the proportions of those receiving detemir and glargine who achieved an HbA(1c) value <= 7.0% without major hypo-glycemia (31.9% and 28.9%, respectively). In addition, there were no significant differences in estimated mean FPG (8.58 and 8.81 rnmol/L; mean difference, -0.23 mmol/L; 95% CI, -1.04 to 0.58) or in basal insulin doses. The basal insulin dose was numerically higher in patients receiving detemir twice rather than once daily (0.47 vs 0.33 U/kg, respectively). The relative risks for total and nocturnal hypoglycemia with detemir versus glargine were 0.94 and 1.12, respectively (both, P = NS). Six patients (2.0%) randomized to the detemir group and 4 (2.7%) randomized to the glargine group withdrew due to adverse events. Conclusions: During 52 weeks of basal-bolus therapy in patients with T1DM, detemir was noninferior to glargine in terms of overall glycemic control (HbA(1c)). When used according to the approved labeling, detemir and glargine did not differ in tolerability or in terms of the occurrence of hypoglycemia. (Clin Ther. 2009; 31:2086-2097) (C) 2009 Excerpta Medica Inc

Probing Interstellar Dust with Infrared Echoes from the Cas A Supernova

We present the analysis of an IRS 5-38 {\mu}m spectrum and MIPS photometric measurements of an infrared echo near the Cassiopeia A supernova remnant observed with the Spitzer Space Telescope. We have modeled the recorded echo accounting for PAHs, quantum-heated carbon and silicate grains, as well as thermal carbon and silicate particles. Using the fact that optical light echo spectroscopy has established that Cas A originated from a type IIb supernova explosion showing an optical spectrum remarkably similar to the prototypical type IIb SN 1993J, we use the latter to construct template data input for our simulations. We are then able to reproduce the recorded infrared echo spectrum by combining the emission of dust heated by the UV burst produced at the shock breakout after the core-collapse and dust heated by optical light emitted near the visual maximum of the supernova light curve, where the UV burst and optical light curve characteristics are based on SN 1993J. We find a mean density of \sim680 H cm^{-3} for the echo region, with a size of a few light years across. We also find evidence of dust processing in the form of a lack of small PAHs with less than \sim300 carbon atoms, consistent with a scenario of PAHs destruction by the UV burst via photodissociation at the estimated distance of the echo region from Cas A. Furthermore, our simulations suggest that the weak 11 {\mu}m features of our recorded infrared echo spectrum are consistent with a strong dehydrogenated state of the PAHs. This exploratory study highlights the potential of investigating dust processing in the interstellar medium through infrared echoes.Comment: 16 pages, 14 figures, accepted for publication in the Astrophysical Journa

Ultra-stable clock laser system development towards space applications

International audienceThe increasing performance of optical lattice clocks has made them attractive for scientific applications in space and thus has pushed the development of their components including the interrogation lasers of the clock transitions towards being suitable for space, which amongst others requires making them more power efficient, radiation hardened, smaller, lighter as well as more mechanically stable. Here we present the development towards a space-compatible interrogation laser system for a strontium lattice clock constructed within the Space Optical Clock (SOC2) project where we have concentrated on mechanical rigidity and size. The laser reaches a fractional frequency instability of 7.9 × 10−16 at 300 ms averaging time. The laser system uses a single extended cavity diode laser that gives enough power for interrogating the atoms, frequency comparison by a frequency comb and diagnostics. It includes fibre link stabilisation to the atomic package and to the comb. The optics module containing the laser has dimensions 60 × 45 × 8 cm3; and the ultra-stable reference cavity used for frequency stabilisation with its vacuum system takes 30 × 30 × 30 cm3. The acceleration sensitivities in three orthogonal directions of the cavity are 3.6 × 10−10/g, 5.8 × 10−10/g and 3.1 × 10−10/g, where g ≈ 9.8 m/s2 is the standard gravitational acceleration

Oral supplementation of healthy adults with 2'-O-fucosyllactose and lacto-N-neotetraose is well tolerated and shifts the intestinal microbiota

The gut microbiota has been established as an important player influencing many aspects of human physiology. Breast milk, the first diet for an infant, contains human milk oligosaccharides (HMO) that shape the infant's gut microbiota by selectively stimulating the growth of specific bacteria, especially bifidobacteria. In addition to their bifidogenic activity, the ability of HMO to modulate immune function and the gut barrier makes them prime candidates to restore a beneficial microbiota in dysbiotic adults and provide health benefits. We conducted a parallel, double-blind, randomised, placebo-controlled, HMO-supplementation study in 100 healthy, adult volunteers, consuming chemically produced 2'-O-fucosyllactose (2'FL) and/or lacto-N-neotetraose (LNnT) at various daily doses and mixes or placebo for 2 weeks. All participants completed the study without premature discontinuation. Supplementation of 2'FL and LNnT at daily doses up to 20 g was shown to be safe and well tolerated, as assessed using the gastrointestinal symptoms rating scale. 16S rRNA sequencing analysis showed that HMO supplementation specifically modified the adult gut microbiota with the primary impact being substantial increases in relative abundance of Actinobacteria and Bifidobacterium in particular and a reduction in relative abundance of Firmicutes and Proteobacteria. This study provides the first set of data on safety, tolerance and impact of HMO on the adult gut microbiota. Collectively, the results from this study show that supplementing the diet with HMO is a valuable strategy to shape the human gut microbiota and specifically promote the growth of beneficial bifidobacteria

Emergent dynamic chirality in a thermally driven artificial spin ratchet

Modern nanofabrication techniques have opened the possibility to create novel functional materials, whose properties transcend those of their constituent elements. In particular, tuning the magnetostatic interactions in geometrically frustrated arrangements of nanoelements called artificial spin ice1, 2 can lead to specific collective behaviour3, including emergent magnetic monopoles4, 5, charge screening6, 7 and transport8, 9, as well as magnonic response10, 11, 12. Here, we demonstrate a spin-ice-based active material in which energy is converted into unidirectional dynamics. Using X-ray photoemission electron microscopy we show that the collective rotation of the average magnetization proceeds in a unique sense during thermal relaxation. Our simulations demonstrate that this emergent chiral behaviour is driven by the topology of the magnetostatic field at the edges of the nanomagnet array, resulting in an asymmetric energy landscape. In addition, a bias field can be used to modify the sense of rotation of the average magnetization. This opens the possibility of implementing a magnetic Brownian ratchet13, 14, which may find applications in novel nanoscale devices, such as magnetic nanomotors, actuators, sensors or memory cells

Public service innovation and multiple institutional logics: the case of hybrid social enterprise providers of health and wellbeing

Public sector organisations are confronted with growing health and social care needs in combination with severe resource constraints, prompting interest in innovative responses to such challenges. Public service and social innovation is poorly understood, particularly where innovators must navigate between the norms, practices and logics of public, private and civil society sectors. We contribute to the understanding of how innovating hybrid organisations are able to creatively combine co-existing logics. Case study evidence from newly established social enterprise providers of health and wellbeing services in England is utilised to examine how innovations are shaped by (i) an incumbent state or public sector logic, and two ‘challenger’ logics relating to (ii) the market and increasing competition; and (iii) civil society, emphasising social value and democratic engagement with employees and service users. The analysis shows how a more fluid and creative interplay of logics can be observed in relation to specific strategies and practices. Within organisations, these strategies relate to the empowerment of staff to be creative, financial management, and knowledge sharing and protection. The interplay of logics shaping social innovation is also found in relationships with key stakeholders, notably public sector funders, service users and service delivery partners. Implications are drawn for innovation in public services and hybrid organisations more broadly

Operator Product Expansion and Quark-Hadron Duality: Facts and Riddles

We review the status of the practical operator product expansion (OPE), when applied to two-point correlators of QCD currents which interpolate to mesonic resonances, in view of the violations of local quark-hadron duality. Covered topics are: a mini-review of mesonic QCD sum rules in vacuum, at finite temperature, or at finite baryon density, a comparison of model calculations of current-current correlation functions in 2D and 4D with the OPE expression, a discussion of meson distribution amplitudes in the light of nonperturbatively nonlocal modifications of the OPE, and a reorganization of the OPE which (partially) resums powers of covariant derivatives.Comment: now 68 pages, 29 figures (1 figure added), habilitation thesis, mild restructuring, typos corrected, about 30 references and corresponding text added, version to be published in Prog. Part. Nucl. Phy