Vibronic coupling explains the ultrafast carotenoid-to-bacteriochlorophyll energy transfer in natural and artificial light harvesters

The initial energy transfer in photosynthesis occurs between the light-harvesting pigments and on ultrafast timescales. We analyze the carotenoid to bacteriochlorophyll energy transfer in LH2 Marichromatium purpuratum as well as in an artificial light-harvesting dyad system by using transient grating and two-dimensional electronic spectroscopy with 10 fs time resolution. We find that F\"orster-type models reproduce the experimentally observed 60 fs transfer times, but overestimate coupling constants, which leads to a disagreement with both linear absorption and electronic 2D-spectra. We show that a vibronic model, which treats carotenoid vibrations on both electronic ground and excited state as part of the system's Hamiltonian, reproduces all measured quantities. Importantly, the vibronic model presented here can explain the fast energy transfer rates with only moderate coupling constants, which are in agreement with structure based calculations. Counterintuitively, the vibrational levels on the carotenoid electronic ground state play a central role in the excited state population transfer to bacteriochlorophyll as the resonance between the donor-acceptor energy gap and vibrational ground state energies is the physical basis of the ultrafast energy transfer rates in these systems

Ultrafast depolarization of the fluorescence in a conjugated polymer

The effect of the extent of pi electron conjugation on the primary photophysics in semiconducting polymers is reported. A rapid depolarization of photoluminescence and transient absorption, which indicates a reorientation of the transition dipole moment by similar to 30 degrees on a sub-100 fs time scale, is observed in the fully conjugated polymer poly[2-(2'-ethylhexyloxy)-5-methoxy-1,4-phenylenevinylene] (MEH-PPV). In contrast, partially conjugated polymers exhibit a much slower depolarization. The results reveal rapid changes of exciton delocalization in the fully conjugated MEH-PPV driven by structural relaxation

FindFoci: a focus detection algorithm with automated parameter training that closely matches human assignments, reduces human inconsistencies and increases speed of analysis

Accurate and reproducible quantification of the accumulation of proteins into foci in cells is essential for data interpretation and for biological inferences. To improve reproducibility, much emphasis has been placed on the preparation of samples, but less attention has been given to reporting and standardizing the quantification of foci. The current standard to quantitate foci in open-source software is to manually determine a range of parameters based on the outcome of one or a few representative images and then apply the parameter combination to the analysis of a larger dataset. Here, we demonstrate the power and utility of using machine learning to train a new algorithm (FindFoci) to determine optimal parameters. FindFoci closely matches human assignments and allows rapid automated exploration of parameter space. Thus, individuals can train the algorithm to mirror their own assignments and then automate focus counting using the same parameters across a large number of images. Using the training algorithm to match human assignments of foci, we demonstrate that applying an optimal parameter combination from a single image is not broadly applicable to analysis of other images scored by the same experimenter or by other experimenters. Our analysis thus reveals wide variation in human assignment of foci and their quantification. To overcome this, we developed training on multiple images, which reduces the inconsistency of using a single or a few images to set parameters for focus detection. FindFoci is provided as an open-source plugin for ImageJ

Subjective evaluation of the environmental quality in China's industrial corridors.

Based on 270 questionnaire surveys in 8 cities of 5 industrial corridors in China, this study aims to examine the effects of industry construction on the evaluation of environmental pollution, natural environment, built environment, personal perception and development and policy. The results show that the evaluations on environmental pollution and landscape design are both below the medium level, but the evaluations of the living comfort and safety are both above the medium level. Further analysis, females usually give lower evaluation scores than males, and age and health situations are negatively related to the evaluation results; People indicate a great desire to reduce the environmental pollution and protect the natural environment. Moreover, the landscape was analysed using colour extraction techniques based on video recording, there are significant correlations between industrial pixel ratio and evaluation results of air quality, vegetation pixel ratio and evaluation results of river water quality, and public facilities pixel ratio and evaluation results of comfort levels

Proving Actionable Racial Disparity Under the California Racial Justice Act

Racial disparity is a fact of the United States criminal justice system, but under the Supreme Court’s holding in McCleskey v. Kemp, racial disparities—even sizable, statistically significant disparities—do not establish an equal protection violation without a showing of “purposeful discrimination.” The California Racial Justice Act (CRJA), enacted in 2020 and further amended in 2022, introduced a first-of-its-kind test for actionable racial disparity even in the absence of a showing of intent, allowing for relief when the “totality of the evidence demonstrates a significant difference” in charging, conviction, or sentencing across racial groups when compared to those who are “similarly situated” and who have engaged in “similar conduct.” Though the CRJA was enacted over two years ago, two obstacles have made its promised remedies exist largely only on paper: confusion about how to apply its new test and a lack of access to the data needed to demonstrate a significant difference. This Article attempts to overcome these obstacles by exploring and interpreting the “significant difference” test and by analyzing a database of disparities that enables controls for criminal history and geography (similarly situated) and overlapping elements (similar conduct) based on comprehensive data from the California Department of Justice. This Article also presents two case studies that demonstrate how defendants might establish an initial showing of significant difference sufficient to successfully move for discovery

Test bed control center design concept for Tank Waste Retrieval Manipulator Systems

This paper describes the design concept for the control center for the Single Shell Tank Waste Retrieval Manipulator System test bed and the design process behind the concept. The design concept supports all phases of the test bed mission, including technology demonstration, comprehensive system testing, and comparative evaluation for further development and refinement of the TWRMS for field operations

Decreased brain venous vasculature visibility on susceptibility-weighted imaging venography in patients with multiple sclerosis is related to chronic cerebrospinal venous insufficiency.

BACKGROUND: The potential pathogenesis between the presence and severity of chronic cerebrospinal venous insufficiency (CCSVI) and its relation to clinical and imaging outcomes in brain parenchyma of multiple sclerosis (MS) patients has not yet been elucidated. The aim of the study was to investigate the relationship between CCSVI, and altered brain parenchyma venous vasculature visibility (VVV) on susceptibility-weighted imaging (SWI) in patients with MS and in sex- and age-matched healthy controls (HC). METHODS: 59 MS patients, 41 relapsing-remitting and 18 secondary-progressive, and 33 HC were imaged on a 3T GE scanner using pre- and post-contrast SWI venography. The presence and severity of CCSVI was determined using extra-cranial and trans-cranial Doppler criteria. Apparent total venous volume (ATVV), venous intracranial fraction (VIF) and average distance-from-vein (DFV) were calculated for various vein mean diameter categories: .9 mm. RESULTS: CCSVI criteria were fulfilled in 79.7% of MS patients and 18.2% of HC (p < .0001). Patients with MS showed decreased overall ATVV, ATVV of veins with a diameter < .3 mm, and increased DFV compared to HC (all p < .0001). Subjects diagnosed with CCSVI had significantly increased DFV (p < .0001), decreased overall ATVV and ATVV of veins with a diameter < .3 mm (p < .003) compared to subjects without CCSVI. The severity of CCSVI was significantly related to decreased VVV in MS (p < .0001) on pre- and post-contrast SWI, but not in HC. CONCLUSIONS: MS patients with higher number of venous stenoses, indicative of CCSVI severity, showed significantly decreased venous vasculature in the brain parenchyma. The pathogenesis of these findings has to be further investigated, but they suggest that reduced metabolism and morphological changes of venous vasculature may be taking place in patients with MS

Quantitative differential proteomics of yeast extracellular matrix: there is more to it than meets the eye

Background: Saccharomyces cerevisiae multicellular communities are sustained by a scaffolding extracellular matrix, which provides spatial organization, and nutrient and water availability, and ensures group survival. According to this tissue-like biology, the yeast extracellular matrix (yECM) is analogous to the higher Eukaryotes counterpart for its polysaccharide and proteinaceous nature. Few works focused on yeast biofilms, identifying the flocculin Flo11 and several members of the HSP70 in the extracellular space. Molecular composition of the yECM, is therefore mostly unknown. The homologue of yeast Gup1 protein in high Eukaryotes (HHATL) acts as a regulator of Hedgehog signal secretion, therefore interfering in morphogenesis and cell-cell communication through the ECM, which mediates but is also regulated by this signalling pathway. In yeast, the deletion of GUP1 was associated with a vast number of diverse phenotypes including the cellular differentiation that accompanies biofilm formation. Methods: S. cerevisiae W303-1A wt strain and gup1Δ mutant were used as previously described to generate biofilmlike mats in YPDa from which the yECM proteome was extracted. The proteome from extracellular medium from batch liquid growing cultures was used as control for yECM-only secreted proteins. Proteins were separated by SDS-PAGE and 2DE. Identification was performed by HPLC, LC-MS/MS and MALDI-TOF/TOF. The protein expression comparison between the two strains was done by DIGE, and analysed by DeCyder Extended Data Analysis that included Principal Component Analysis and Hierarchical Cluster Analysis. Results: The proteome of S. cerevisiae yECM from biofilm-like mats was purified and analysed by Nano LC-MS/MS, 2D Difference Gel Electrophoresis (DIGE), and MALDI-TOF/TOF. Two strains were compared, wild type and the mutant defective in GUP1. As controls for the identification of the yECM-only proteins, the proteome from liquid batch cultures was also identified. Proteins were grouped into distinct functional classes, mostly Metabolism, Protein Fate/Remodelling and Cell Rescue and Defence mechanisms, standing out the presence of heat shock chaperones, metalloproteinases, broad signalling cross-talkers and other putative signalling proteins. The data has been deposited to the ProteomeXchange with identifier PXD001133.Conclusions: yECM, as the mammalian counterpart, emerges as highly proteinaceous. As in higher Eukaryotes ECM, numerous proteins that could allow dynamic remodelling, and signalling events to occur in/and via yECM were identified. Importantly, large sets of enzymes encompassing full antagonistic metabolic pathways, suggest that mats develop into two metabolically distinct populations, suggesting that either extensive moonlighting or actual metabolism occurs extracellularly. The gup1Δ showed abnormally loose ECM texture. Accordingly, the correspondent differences in proteome unveiled acetic and citric acid producing enzymes as putative players in structural integrity maintenance.This work was funded by the Marie Curie Initial Training Network GLYCOPHARM (PITN-GA-2012-317297), and by national funds from FCT I.P. through the strategic funding UID/BIA/04050/2013. Fábio Faria-Oliveira was supported by a PhD scholarship (SFRH/BD/45368/2008) from FCT (Fundação para a Ciência e a Tecnologia). We thank David Caceres and Montserrat MartinezGomariz from the Unidad de Proteómica, Universidad Complutense de Madrid – Parque Científico de Madrid, Spain for excellent technical assistance in the successful implementation of all proteomics procedures including peptide identification, and Joana Tulha from the CBMA, Universidade do Minho, Portugal, for helping with the SDS-PAGE experiments, and the tedious and laborious ECM extraction procedures. The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium, via the PRIDE partner repository, with the dataset identifier PXD001133. We would like to thank the PRIDE team for all the help and support during the submission process.info:eu-repo/semantics/publishedVersio

Large magnetoresistance and magnetocaloric effect above 70 K in Gd2Co2Al, Gd2Co2Ga and Gd7Rh3

The electrical resistivity, magnetization and heat-capacity behavior of the Gd-based compounds, Gd2Co2Al, Gd2Co2Ga and Gd7Rh3, ordering magnetically at TC= 78 K, TC= 76 K and TN= 140 K have been investigated as a function of temperature and magnetic field. All these compounds are found to show large magnetoresistance (with a negative sign) in the paramagnetic state at rather high temperatures with the magnitude peaking at respective magnetic ordering temperatures. There is a corresponding behavior in the magnetocaloric effect as inferred from the entropy derived from these data.Comment: Phys. Rev. 65 (2005) 49