Reviewing ecopsychology research: exploring five databases and considering the future

This brief article aims to provide an overview of the current dispersal of the term ecopsychology within the academic literature. It summarizes the results found when entering the term ecopsychology into five academic databases. The numbers of hits are discussed and comparisons are made with other related terms. The results are further broken down to provide a snapshot of the type of material referred to in these searches. A more detailed inspection of the material referenced in journal articles is undertaken. Here, popular outlets and dates of publication are highlighted. A final search for articles that report original research data directly associated with ecopsychology is also reported. Possible reasons for the low yield and the implications of this are highlighted along with suggested pathways forward

Structures and functions of carotenoids bound to reaction centers from purple photosynthetic bacteria

The photoprotective function of 15,15'-cis-carotenoids bound to the photosynthetic reaction centers (RCs) of purple bacteria has been studied using carotenoids reconstituted into carotenoidless RCs from Rhodobacter sphaeroides strain R26.1. The triplet-energy level of the carotenoid has been proposed to affect the quenching of the triplet state of special-pair bacteriochlorophyll (P). This was investigated using microsecond flash photolysis to detect the carotenoid triplets as a function of the number of conjugated double bonds, n. The carotenoid triplet signals were extracted by using singular-value decomposition (SVD) of the huge matrices data, and were confirmed for those having n = 8 to 11. This interpretation assumes that the reconstituted carotenoids occupy the same binding site in the RC. We have been able to confirm this assumption using X-ray crystallography to determine the structures of carotenoidless, wild-type carotenoid-containing, and 3,4-dihydro-spheroidene-reconstituted RCs. The X-ray study also emphasized the importance of the methoxy group of the carotenoids for binding to the RCs. Electroabsorption (Stark) spectroscopy was used to investigate the effect of the carotenoid on the electrostatic field around P. This electrostatic field changed by 10 % in the presence of the carotenoid

Characterisation of a pucBA deletion mutant from Rhodopseudomonas palustris lacking all but the pucBAd genes

Rhodopseudomonas palustris is a species of purple photosynthetic bacteria that has a multigene family of puc genes that encode the alpha and beta apoproteins, which form the LH2 complexes. A genetic dissection strategy has been adopted in order to try and understand which spectroscopic form of LH2 these different genes produce. This paper presents a characterisation of one of the deletion mutants generated in this program, the pucBAd only mutant. This mutant produces an unusual spectroscopic form of LH2 that only has a single large NIR absorption band at 800 nm. Spectroscopic and pigment analyses on this complex suggest that it has basically a similar overall structure as that of the wild-type HL LH2 complex. The mutant has the unique phenotype where the mutant LH2 complex is only produced when cells are grown at LL. At HL the mutant only produces the LH1-RC core complex

Phonon-induced decoherence for a quantum dot spin qubit operated by Raman passage

We study single-qubit gates performed via stimulated Raman adiabatic passage (STIRAP) on a spin qubit implemented in a quantum dot system in the presence of phonons. We analyze the interplay of various kinds of errors resulting from the carrier-phonon interaction as well as from quantum jumps related to nonadiabaticity and calculate the fidelity as a function of the pulse parameters. We give quantitative estimates for an InAs/GaAs system and identify the parameter values for which the error is considerably minimized, even to values below $10^{-4}$ per operation.Comment: Final version; considerable extensions; 18 pages, 7 figure

9. Comparison between conventional simulator planning and conformal 3-D planning for cervical cancer teletherapy

The using of simulator planning based on bony landmarks for pelvic irradiation of cervix cancer is associated with a risk in a geographical miss, which may be generated by inadequate knowledge of the individual anatomy. 3D treatment planning system let us know an individual topography of pelvic organs, enables to mark a PTV and it allows more adequate coverage.PurposeThe aim of this study was to evaluate a benefit resulting from 3D treatment planning for teletherapy of cervical cancer.Material and methodIn our study on 15 patients with cervical carcinoma in the stage IIIB simulator planning of, box” technique was performed. Next we defined the PTV in 3D-planning system and compared the dose distribution, obtained with both methods, in the target volumes and organs at risk using dose-volume histograms.ResultsIn 4 of 15 patients the encompassment of the PTV by the treated volume was inadequate in case of simulator planning. The treated volumes based on 3D-planning were 8% smaller than volumes based on simulator planning. The treated volume/planning target volume ratio was 1,64 for simulator planning and 1,50 for 3D planning. 3D-planning system resulted in a reduction of the irradiated bladder volume (−12%) and the bowel volume (−9%). The bladder and bowel volumes in treated volumes depended on bladder fillings.ConclusionsImplementation of 3D treatment planning system in teletherapy of cervical cancer helps to avoid a geographical miss, to reduce both the treated volume and the doses delivered to organs at risk

Adsorption of CO on a Platinum (111) surface - a study within a four-component relativistic density functional approach

We report on results of a theoretical study of the adsorption process of a single carbon oxide molecule on a Platinum (111) surface. A four-component relativistic density functional method was applied to account for a proper description of the strong relativistic effects. A limited number of atoms in the framework of a cluster approach is used to describe the surface. Different adsorption sites are investigated. We found that CO is preferably adsorbed at the top position.Comment: 23 Pages with 4 figure

Influence of subunit structure on the oligomerization state of light harvesting complexes: a free energy calculation study

Light harvesting complexes 2 (LH2) from Rhodospirillum (Rs.) molischianum and Rhodopseudomonas (Rps.) acidophila form ring complexes out of eight or nine identical subunits, respectively. Here, we investigate computationally what factors govern the different ring sizes. Starting from the crystal structure geometries, we embed two subunits of each species into their native lipid-bilayer/water environment. Using molecular dynamics simulations with umbrella sampling and steered molecular dynamics, we probe the free energy profiles along two reaction coordinates, the angle and the distance between two subunits. We find that two subunits prefer to arrange at distinctly different angles, depending on the species, at about 42.5 deg for Rs. molischianum and at about 38.5 deg for Rps. acidophila, which is likely to be an important factor contributing to the assembly into different ring sizes. Our calculations suggest a key role of surface contacts within the transmembrane domain in constraining these angles, whereas the strongest interactions stabilizing the subunit dimers are found in the C-, and to a lesser extent, N-terminal domains. The presented computational approach provides a promising starting point to investigate the factors contributing to the assembly of protein complexes, in particular if combined with modeling of genetic variants.Comment: 28 pages, 7 figures, LaTeX2e - requires elsart.cls (included), submitted to Chemical Physic

Zeros and the functional equation of the quadrilateral zeta function

In this paper, we show that all real zeros of the bilateral Hurwitz zeta function $Z(s,a):=\zeta (s,a) + \zeta (s,1-a)$ with $1/4 \le a \le 1/2$ are on only the non-positive even integers exactly same as in the case of $(2^s-1) \zeta (s)$. We also prove that all real zeros of the bilateral periodic zeta function $P(s,a):={\rm{Li}}_s (e^{2\pi ia}) + {\rm{Li}}_s (e^{2\pi i(1-a)})$ with $1/4 \le a \le 1/2$ are on only the negative even integers just like $\zeta (s)$. Moreover, we show that all real zeros of the quadrilateral zeta function $Q(s,a):=Z(s,a) + P(s,a)$ with $1/4 \le a \le 1/2$ are on only the negative even integers. On the other hand, we prove that $Z(s,a)$, $P(s,a)$ and $Q(s,a)$ have at least one real zero in $(0,1)$ when $0<a<1/2$ is sufficiently small. The complex zeros of these zeta functions are also discussed when $1/4 \le a \le 1/2$ is rational or transcendental. As a corollary, we show that $Q(s,a)$ with rational $1/4 < a < 1/3$ or $1/3 < a < 1/2$ does not satisfy the analogue of the Riemann hypothesis even though $Q(s,a)$ satisfies the functional equation that appeared in Hamburger's or Hecke's theorem and all real zeros of $Q(s,a)$ are located at only the negative even integers again as in the case of $\zeta (s)$.Comment: 12 pages. We changed the title. Some typos are correcte

The native architecture of a photosynthetic membrane

In photosynthesis, the harvesting of solar energy and its subsequent conversion into a stable charge separation are dependent upon an interconnected macromolecular network of membrane-associated chlorophyll–protein complexes. Although the detailed structure of each complex has been determined, the size and organization of this network are unknown. Here we show the use of atomic force microscopy to directly reveal a native bacterial photosynthetic membrane. This first view of any multi-component membrane shows the relative positions and associations of the photosynthetic complexes and reveals crucial new features of the organization of the network: we found that the membrane is divided into specialized domains each with a different network organization and in which one type of complex predominates. Two types of organization were found for the peripheral light-harvesting LH2 complex. In the first, groups of 10–20 molecules of LH2 form light-capture domains that interconnect linear arrays of dimers of core reaction centre (RC)–light-harvesting 1 (RC–LH1–PufX) complexes; in the second they were found outside these arrays in larger clusters. The LH1 complex is ideally positioned to function as an energy collection hub, temporarily storing it before transfer to the RC where photochemistry occurs: the elegant economy of the photosynthetic membrane is demonstrated by the close packing of these linear arrays, which are often only separated by narrow 'energy conduits' of LH2 just two or three complexes wide