Adaptive dual-comb spectroscopy in the green region

Dual-comb spectroscopy is extended to the visible spectral range with a set-up based on two frequency-doubled femtosecond ytterbium-doped fiber lasers. The dense rovibronic spectrum of iodine around 19240 cm-1 is recorded within 12 ms at Doppler-limited resolution with a simple scheme that only uses free-running femtosecond lasers

Raman-induced Kerr-effect dual-comb spectroscopy

We report on the first demonstration of nonlinear dual-frequency-comb spectroscopy. In multi-heterodyne femtosecond Raman-induced Kerr-effect spectroscopy, the Raman gain resulting from the coherent excitation of molecular vibrations by a spectrally-narrow pump is imprinted onto the femtosecond laser frequency comb probe spectrum. The birefringence signal induced by the nonlinear interaction of these beams and the sample is heterodyned against a frequency comb local oscillator with a repetition frequency slightly different from that of the comb probe. Such time-domain interference provides multiplex access to the phase and amplitude Raman spectra over a broad spectral bandwidth within a short measurement time. Experimental demonstration, at a spectral resolution of 200 GHz, a measurement time of 293 {\mu}s and a sensitivity of 10^-6, is given on liquid samples exhibiting a C-H stretch Raman shift.Comment: 7 pages, 4 figure

Precision spectroscopy of the 3s-3p fine structure doublet in Mg+

We apply a recently demonstrated method for precision spectroscopy on strong transitions in trapped ions to measure both fine structure components of the 3s-3p transition in 24-Mg+ and 26-Mg+. We deduce absolute frequency reference data for transition frequencies, isotope shifts and fine structure splittings that are in particular useful for comparison with quasar absorption spectra, which test possible space-time variations of the fine structure constant. The measurement accuracy improves previous literature values, when existing, by more than two orders of magnitude

Energy Expenditure and Cost during Walking after Stroke: A Systematic Review

OBJECTIVES: To systematically review the evidence to determine energy expenditure (EE) in volume of oxygen uptake (V̇O2) (mL/kg/min) and energy cost in oxygen uptake per meter walked (V̇O2/walking speed; mL/kg/m) during walking poststroke and how it compares with healthy controls; and to determine how applicable current exercise prescription guidelines are to stroke survivors. DATA SOURCES: Cochrane Central Register of Controlled Trials, MEDLINE, Embase, and CINAHL were searched on October 9, 2014, using search terms related to stroke and EE. Additionally, we screened reference lists of eligible studies. STUDY SELECTION: Two independent reviewers screened titles and abstracts of 2115 identified references. After screening the full text of 144 potentially eligible studies, we included 29 studies (stroke survivors: n=501, healthy controls: n=123), including participants with confirmed stroke and a measure of V̇O2 during walking using breath-by-breath analysis. Studies with (9 studies) and without (20 studies) a healthy control group were included. DATA EXTRACTION: Two reviewers independently extracted data using a standard template, including patient characteristics, outcome data, and study methods. DATA SYNTHESIS: Mean age of stroke survivors was 57 years (range, 40-67y). Poststroke EE was highly variable across studies and could not be pooled because of high heterogeneity. EE during steady-state overground walking at matched speeds was significantly higher in stroke survivors than healthy controls (mean difference in V̇O2, 4.06 mL/kg/min; 95% confidence interval [CI], 2.21-5.91; 1 study; n=26); there was no significant group difference at self-selected speeds. Energy cost during steady-state overground walking was higher in stroke survivors at both self-selected (mean difference, .47 mL/kg/m; 95% CI, .29-.66; 2 studies; n=38) and matched speeds compared with healthy controls (mean difference, .27 mL/kg/m; 95% CI, .03-.51; 1 study; n=26). CONCLUSIONS: Stroke survivors expend more energy during walking than healthy controls. Low-intensity exercise as described in guidelines might be at a moderate intensity level for stroke survivors; there is a need for stroke-specific exercise guidelines

The Ni-II, Hg-II and Cu-II complexes of 12-membered-ring mixed-donor macrocycles

The structures of diaqua(1,7-dioxa-4-thia-10-azacyclododecane)nickel dinitrate, [Ni(C8H17NO2S)(H2O)(2)](NO3)(2), (I), bis(nitrato-O,O')(1,4,7-trioxa-10-azacyclododecane)mercury, [Hg(NO3)(2)(C8H17NO3)], (II), and aqua(nitrato-O)(1-oxa-4,7,10-triazacyclododecane)copper nitrate, [Cu(NO3)(C8H19N3O)(H2O)]NO3, (III), reveal each macrocycle binding in a tetradentate manner. The conformations of the ligands in (I) and (III) are the same and distinct from that identified for (II). These differences are in agreement with molecular-mechanics predictions of ligand conformation as a function of metal-ion size

An Early Mobilization Protocol Successfully Delivers More and Earlier Therapy to Acute Stroke Patients: Further Results From Phase II of AVERT.

Background: The optimal physical therapy dose in acute stroke care is unknown. The authors hypothesized that physical therapy would be significantly different between treatment arms in a trial of very early and frequent mobilization (VEM) and that immobility-related adverse events would be associated with therapy dose. Methods: This study was a single-blind, multicenter, randomized control trial. Patients admitted to a stroke unit <24 hours of stroke randomized to standard care (SC) or intervention, SC plus additional early out-of-bed therapy (VEM). Timing, amount, and type of therapy recorded throughout the trial. Adverse events were recorded to 3 months. Results: A total of 71 patients (SC n = 33, VEM n = 38) received 788 therapy sessions in the first 2 weeks of stroke. Schedule (hours to first mobilization, dose per day, frequency and session duration) and nature (percentage out-of-bed activity) of therapy differed significantly between groups (P ≤ .001 for all components). Mobilization was earlier, happened on average 3 times per day in those receiving VEM, with the proportion of out-of-bed activity double in VEM session (median SC 42.5%, VEM 85.5%). SC consisted of 17 minutes of occupational and physiotherapy per day and was the same between groups. Number of immobility-related adverse events 3 months poststroke was not associated with therapy dose or frequency. Conclusions: The authors detailed usual care and intervention therapy provided to patients from admission to 14 days after stroke. The therapy schedule was markedly different in the intervention arm, but whether this schedule reduces complications or improves outcome is unknown

Pesticide seed treatments containing neonicotinoids have limited effect on soil microbial community structure under different tillage regimes

Pesticide seed treatments (PST) which contain fungicides and insecticides are commonly used in agriculture; however, little is known about their effect on soil microbial communities and soil health. Neonicotinoids – controversial insecticides which are common in PST – have received criticism due to potential non-target effects. While fungal pathogens need to be moderated, PST have the potential to disturb broader fungal communities which could lead to reduced nutrient cycling and poor soil health. Given the broad use of PST, their effect on soil fungi needs to be studied within the context of other agricultural management practices. For example, tillage regimes can result in distinct fungal communities which may respond differently to PST. An experimental site was established in 2013 with a corn-soy rotation under three tillage treatments: Full-till, Strip-till, and No-till. Since 2016, seeds with or without PST (fungicides and insecticides) were planted under each tillage regime in a fully factorial design. In 2018, bulk soil was collected from within rows while soy was growing. A range of soil physicochemical variables were measured, and soil function was determined with substrate-induced respiration and enzyme assays. DNA was extracted from soil and the ITS region was sequenced to determine fungal community structure and diversity. While tillage significantly affected fungal community structure (p \u3c 0.01), there was no effect of PST on either community structure (p = 0.59) or diversity (p = 0.52). This indicates that PST does not affect bulk soil fungal communities; however, they may have an impact at different temporal or spatial scales than those studied here. Across all treatments, fungal community structure correlated with soil water holding capacity (rs = 0.23, p = 0.04) and electrical conductivity (rs = 0.26, p = 0.01). Despite not finding an effect of PST on fungal communities, we did find that PST increased potentially mineralizable nitrogen under no-till and shifted community level physiological profiles determined by substrate-induced respiration. These results suggest that while PST can affect certain aspects of soil health, there are no clear effects on the soil fungal community

The 2010 ILSO-ISRU Field Test at Mauna Kea, Hawaii: Results from the Miniaturised Mossbauer Spectrometers Mimos II and Mimos IIA

For the advanced Moessbauer instrument MIMOS IIA, the new detector technologies and electronic components increase sensitivity and performance significantly. In combination with the high energy resolution of the SDD it is possible to perform X-ray fluorescence analysis simultaneously to Moessbauer spectroscopy. In addition to the Fe-mineralogy, information on the sample's elemental composition will be gathered. The ISRU 2010 field campaign demonstrated that in-situ Moessbauer spectroscopy is an effective tool for both science and feedstock exploration and process monitoring. Engineering tests showed that a compact nickel metal hydride battery provided sufficient power for over 12 hr of continuous operation for the MIMOS instruments

Angular Forces Around Transition Metals in Biomolecules

Quantum-mechanical analysis based on an exact sum rule is used to extract an semiclassical angle-dependent energy function for transition metal ions in biomolecules. The angular dependence is simple but different from existing classical potentials. Comparison of predicted energies with a computer-generated database shows that the semiclassical energy function is remarkably accurate, and that its angular dependence is optimal.Comment: Tex file plus 4 postscript figure