In Photosystem I (PS I) long-wavelength chlorophylls (LWC) of the core antenna are known to extend the spectral region up to 750 nm for absorbance of light that drives photochemistry. Here we present clear evidence that even far-red light with wavelengths beyond 800 nm, clearly outside the LWC absorption bands, can still induce photochemical charge separation in PS I throughout the full temperature range from 295 to 5 K. At room temperature, the photoaccumulation of P700+• was followed by the absorbance increase at 826 nm. At low temperatures (T < 100 K), the formation of P700+•FA/B–• was monitored by the characteristic EPR signals of P700+• and FA/B–• and by the characteristic light-minus-dark absorbance difference spectrum in the QY region.P700 oxidation was observed upon selective excitation at 754, 785, and 808 nm, using monomeric and trimeric PS I core complexes of Thermosynechococcus elongatus and Arthrospira platensis, which differ in the amount of LWC. The results show that the LWC cannot be responsible for the long-wavelength excitation-induced charge separation at low temperatures, where thermal uphill energy transfer is frozen out. Direct energy conversion of the excitation energy from the LWC to the primary radical pair, e.g., via a superexchange mechanism, is excluded, because no dependence on the content of LWC was observed. Therefore, it is concluded that electron transfer through PS I is induced by direct excitation of a proposed charge transfer (CT) state in the reaction center. A direct signature of this CT state is seen in absorbance spectra of concentrated PS I samples, which reveal a weak and featureless absorbance band extending beyond 800 nm, in addition to the well-known bands of LWC (C708, C719 and C740) in the range between 700 and 750 nm. The present findings suggest that nature can exploit CT states for extending the long wavelength limit in PSI even beyond that of LWC. Similar mechanisms may work in other photosynthetic systems and in chemical systems capable of photoinduced electron transfer processes in general.

Background Attention deficit/hyperactivity disorder (ADHD) has a negative impact on several domains of life. However, there is a shortage of evidence-based non-pharmacological treatments for adolescents with ADHD. A structured skills training group (SSTG) based on dialectical behaviour therapy (DBT) has been used in adult patients with ADHD with some promising results, although the treatment has not yet been adapted or evaluated for adolescents with ADHD. This study protocol describes how this treatment was adapted for an adolescent population and how the efficacy of the SSTG will be evaluated using a randomised controlled trial (RCT) design. Methods A sample of 184 adolescents (15–18 years of age) with a diagnosis of ADHD has been recruited from seven child and adolescent psychiatric outpatient units and randomised to either the SSTG or an active control group based on psychoeducation. Measures are conducted weekly during the treatment, as well as 2 weeks before treatment and 2 weeks and 6 months after treatment. The primary outcome measures are ADHD symptoms, functional impairment, quality of life and mindfulness. Secondary outcome measures are symptoms of comorbid psychopathology, perceived stress and sleep problems. This article describes the design, methods and analysis plan for evaluating the efficacy of the SSTG. Discussion The study will be the first RCT to examine the acceptability and efficacy of a SSTG based on DBT adapted for adolescents with ADHD. We believe that the study will extend the current knowledge base about psychological treatment for adolescents with ADHD. Trial registration ISRCTN registry ( ISRCTN17366720 ). Retrospectively registered May 112,016. Electronic supplementary material The online version of this article (10.1186/s12888-019-2133-4) contains supplementary material, which is available to authorized users.

Books on natural cataclysm, often climate-induced, are in vogue. Two books, Bruce Johansen's The Global Warming Combat Manual (Praeger, 2008) and Bill McGuire's Seven Years to Save the Planet (Weidenfeld & Nicolson, 2008), seek to make readers more environmentally aware. McGuire explains how our homes can be made more energy efficient and our holidays greener. He recommends draconian measures to reduce China's greenhouse-gas emissions, and highlights the battle over crops for biofuels and for food production. The Global Warming Combat Manual discusses climatedriven changes in US environmental policy and practice. By describing recent switches-the increasing use of wind power in Texas, for example-and emerging technologies and trends, Johansen lays out a range of solutions for minimizing climate change.

In many aerospace systems it is necessary to periodically transform vectors from a rotating Cartesian coordinate system to a reference Cartesian system. The transformation matrix is updated repeatedly through measurements and computations; however, since the corresponding computational algorithrn is not perfect, the resultant matrix is erroneous and quite often nonorthogonal. In order to correct the nonorthogonality error of the matrix, an orthogonalization process is used to obtain an estimate of the correct orthogonal transformation matrix. The estimate is defined as the orthogonal matrix which is the closest, in the Euclidean sense, to the erroneous one; that is, if XO is the erroneous transformation matrix, then the estimate X is that 3 X 3 matrix X which minimizes the Euclidean norm Abstract Polar decomposition of matrices is used here to investigate the convergence properties of iterative orthogonalization processes. lt is shown that, applying this decomposition, the investigation of a general iterative process of a certain form can be reduced to the investigation of a scalar iterative process which is simple. Three known iterative orthogonalization processes, which are special cases of the general process, are analyzed, their convergence rate (order) is determined, and their range of convergence is established in terms of the spectral radius of the modulus of the matrix which is being orthogonalyzed.subject to the constraint XtX -I= .(1b) Polar Decomposition of MatricesIn the ensuing discussion we make use of the following two theorems.Theorem 1: Every real matrix A can be represented in the formswhere R and R are positive semidefinite matrices and U, U are orthogonal matrices.The proof of this theorem is a special case of the proof given by Gantmacher [1 ] who shows thatR and R are known as the left and right moduli, respectively, of A.Theorem 2: Let Mr be the set ofall r X r ortho£onal matrices. For an arbitrary r X r matrix A let A = UR where U E Mr and R is a real positive semidefinite matrix. Then for any orthogonal matrix Q E M, 11 U-Al IE < IIQ -Al IE

We examined perceived stress and sleep problems in adolescent ADHD and whether this varies as a function of ADHD presentation and sex. Further, we mapped structural associations between ADHD symptoms, comorbid symptoms, perceived stress, and sleep problems. Participants were 306 adolescents aged 13–19 years (66.8% females, 193 had an ADHD diagnosis, 113 were controls). Parents rated ADHD symptoms, all other constructs were self-rated. Adolescents with ADHD had elevated levels of perceived stress and sleep problems. Girls with ADHD reported the highest levels of perceived stress. Emotional symptoms mediated the effect of inattention whereas conduct problems mediated the effect of hyperactivity/impulsivity on stress and sleep. Perceived stress and sleep problems should be considered when mapping ADHD-related problems. Comorbid symptoms are potential intervention targets that may increase treatment response.