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Fluorescence depolarization studies of heteroatom-doped CDs

In this work, we exploited time-resolved fluorescence polarization anisotropy (TRFA) to characterize un-doped and doped carbon dots (CDs). The rotational correlation time related to the size of the particle through classical Stokes-Einstein-Debye equation. The TRFA technique applied in this study achieves picoseconds time resolution, which approximately corresponds to the particle size determinati

Conclusions about turbulent exchange coefficients from model studies

Turbulent exchange coefficients are studied by field experiments and by mathematical models. The field experiments give a horizontal diffusivity of about 200 em'/s- The vertical exchange coefficient departs on the wind and is about 10 em'/s. Il has a maximum value a few metres below the surface and lends to fall to molecular values in the thermocline. Only where the thermocline is in contact with

Dynamic ratiometric imaging of cytosolic free Ca2+ in skeletal muscle cells using 340/385-nm light-emitting diode illuminators

Calcium-sensitive fluorescent indicators fall broadly into two categories, ratiometric (dual-wavelength) or single-wavelength indicators based on their response to a calcium elevation. Ratiometric indicators shift either their excitation or their emission wavelengths in response to calcium, allowing the concentration of intracellular calcium to be determined from the ratio of fluorescence emission

Spectral and kinetic effects accompanying the assembly of core complexes of Rhodobacter sphaeroides

In the present work, spectral and kinetic changes accompanying the assembly of the light-harvesting 1 (LH1) complex with the reaction center (RC) complex into monomeric RC-LH1 and dimeric RC-LH1-PufX core complexes of the photosynthetic purple bacterium Rhodobacter sphaeroides are systematically studied over the temperature range of 4.5–300 K. The samples were interrogated with a combination of op

Dimerization of core complexes as an efficient strategy for energy trapping in Rhodobacter sphaeroides

In the purple phototrophic bacterium Rhodobacter sphaeroides, light harvesting LH2 complexes transfer absorbed solar energy to RC-LH1-PufX core complexes, which are mainly found in the dimeric state. Many other purple phototrophs have monomeric core complexes and the basis for requiring dimeric cores is not fully established, so we analysed strains of Rba. sphaeroides that contain either native di

What Caregivers Like the Most (and Least) About Cognitive Behavioral Therapy for Youth Anxiety: A Mixed Methods Approach

Cognitive behavioral therapy (CBT) is an efficacious therapy for youth anxiety disorders. Caregivers are key stakeholders in youth therapy, and their feedback on treatment can help to inform intervention personalization. This mixed-methods study applied a systematic inductive thematic analysis to identify themes among most- and least-liked CBT features reported by caregivers using open-ended respo

Efficiency of light harvesting in a photosynthetic bacterium adapted to different levels of light

In this study, we use the photosynthetic purple bacterium Rhodobacter sphaeroides to find out how the acclimation of photosynthetic apparatus to growth conditions influences the rates of energy migration toward the reaction center traps and the efficiency of charge separation at the reaction centers. To answer these questions we measured the spectral and picosecond kinetic fluorescence responses a

Transparent electrode patterning using laser ablation for in-plane switching liquid crystal display

Transparent indium tin oxides (ITO) electrodes were patterned using flash lamp pumped Q-switched Nd: YAG laser ablation technique. The Optical microscopy, atomic force microscopy and energy dispersive x-ray spectrum along with scanning electron microscope analysis shows the depth and width of the ablated area and the elements available in the ablated area. In-plane switching liquid crystal display

Snowmelt estimated from energy budget studies

The snowmelt at a point is estimated through a simplified energy budget. From the energy equation a degree-day method is derived. The rate of snowmelt isfound as a constant multiplied by the temperature excess over an equilibrium temperature which depends on solar radiation.The snowmelt events in Kiruna (3 years) and LuleH (4 years) are analysed utilizing energy balance computations and the degree

Wind induced circulation in lakes

In most lakes the wind is the most important flow generating mechanism. In this paper the problem of wind generated circulation - directly wind induced currents and seiches - in small lakes is reviewed. Many field observations are presented and discussed. In the thermocline and the hypolimnion forced seiche currents are shown to dominate the directly induced wind currents. Different kind of non-co

Evaporation from a snow cover : Discussion and review of measurements

Possible evaporation rates from a snow surface with respect to available energy and vapour pressure deficit in the air are discussed. In literature reported measurements and measurements carried out at the University of Luleå are analysed. It is found that for northern areas the total amount of evaporation during the whole snow covered season amounts only to 10–20 mm.Different formulas for estimat

Advantages of binary stochastic synapses for hardware spiking neural networks with realistic memristors

Hardware implementing spiking neural networks (SNNs) has the potential to provide transformative gains in energy efficiency and throughput for energy-restricted machine-learning tasks. This is enabled by large arrays of memristive synapse devices that can be realized by various emerging memory technologies. But in practice, the performance of such hardware is limited by non-ideal features of the m

The importance of refreezing on the diurnal snowmelt cycle

A method for including night-time refreezing of the top layer of a snowpack in the degree-day method for computing daily snowmelt rates is presented. It is found that during days of large diurnal temperature variations the daily melt is more determined by the day-time conditions than by the daily mean conditions. Applications are made to an open area and a forested area. The refreezing-degree-day

Ground- and meltwater in the snowmelt induced runoff

The snowmelt runoff process from small basins is discussed. A differentiation is made between overland flow in the snowpack and groundwater flow induced by infiltrating meltwater. The effect of variations of the snowmelt intensity on streamflow is studied. It is shown that the runoff is high from the first day of snowmelt runoff if the streamflow is caused by overland flow, and that there are pron

Ett utile dulci för ungdom : Ungdomens bibliotek som bokserie och förlagssatsning

The Swedish publishing house Svensk läraretidnings förlag published the extensive book series Barnbiblioteket Saga (the Children’s Library Saga) between 1899 and 1970. In this article, the publisher’s less extensive book series Ungdomens bibliotek (the Library of Youth) is analysed as an example of the marketing techniques that the publishing house used to reach different target groups. The articl

Inference and reconstruction of the heimdallarchaeial ancestry of eukaryotes

In the ongoing debates about eukaryogenesis-the series of evolutionary events leading to the emergence of the eukaryotic cell from prokaryotic ancestors-members of the Asgard archaea play a key part as the closest archaeal relatives of eukaryotes 1. However, the nature and phylogenetic identity of the last common ancestor of Asgard archaea and eukaryotes remain unresolved 2-4. Here we analyse dist

Percolation of meltwater through a snowpack

The hydraulics of meltwater percolation through a snowpack is analyzed in some detail. An implicit numerical model is used for determining the meltwater movement. The effect of freezing fronts of the free liquid water in the snowpack is evaluated. It is shown that even after a moderately cold night, it takes several hours of snowmelt before the snowpack again reaches its irreducible liquid content