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A viewpoint: Why chlorophyll a?

Chlorophyll a (Chl a) serves a dual role in oxygenic photosynthesis: in light harvesting as well as in converting energy of absorbed photons to chemical energy. No other Chl is as omnipresent in oxygenic photosynthesis as is Chl a, and this is particularly true if we include Chl a2, (=[8-vinyl]-Chl a), which occurs in Prochlorococcus, as a type of Chl a. One exception to this near universal patter

Escherichia coli P fimbriae utilize the Toll-like receptor 4 pathway for cell activation

Fimbriae mediate bacterial attachment to host cells and provide a mechanism for tissue attack. They activate a host response by delivery of microbial products such as lipopolysaccharide (LPS) or through direct fimbriae-dependent signalling mechanisms. By coupling to glycosphingolipid (GSL) receptors, P fimbriae trigger cytokine responses in CD14 negative host cells. Here we show that P fimbriae ut

The t+n+n system and 5H

The one-proton knockout channel from 6He (240 MeV/u) impinging on a carbon target has been investigated. The triton fragments originating from this channel were detected in coincidence with the two neutrons. A broad structure, peaked at 3 MeV above the t+2n threshold, is observed in the t+n+n-relative energy spectrum. It is shown that this structure is mainly due to a I(pi)=1/2(+) resonance as exp

Possible association between the androgen receptor gene and autism spectrum disorder

Autism is a highly heritable disorder but the specific genes involved remain largely unknown. The higher prevalence of autism in men than in women, in conjunction with a number of other observations, has led to the suggestion that prenatal brain exposure to androgens may be of importance for the development of this condition. Prompted by this hypothesis, we investigated the potential influence of

The mitochondrial external NADPH dehydrogenase modulates the leaf NADPH/NADP+ ratio in transgenic Nicotiana sylvestris

Plant mitochondria contain alternative external NAD(P)H dehydrogenases, which oxidise cytosolic NADH or NADPH and reduce ubiquinone without inherent linkage to proton pumping and ATP production. In potato, St-NDB1 is an external Ca2+-dependent NADPH dehydrogenase. The physiological function of this enzyme was investigated in homozygous Nicotiana sylvestris lines overexpressing St-ndb1 and co-suppr

Differential regulation of mnp2, a new manganese peroxidase-encoding gene from the ligninolytic fungus Trametes versicolor PRL 572

A peroxidase-encoding gene, mnp2, and its corresponding cDNA were characterized from the white-rot basidiomycete Trametes versicolor PRL 572. We used quantitative reverse transcriptase-mediated PCR to identify mnp2 transcripts in nutrient-limited stationary cultures. Although mnp2 lacks upstream metal response elements (MREs), addition of MnSO4 to cultures increased mnp2 transcript levels 250-fold

Strategies Applied by Women in Coping With ad-hoc Demands for Unauthorized User Fees During Pregnancy and Childbirth. A Focus Group Study From Angola.

Our aim in this study was to explore women's responses to reported ad-hoc demands for unauthorized user fees during pregnancy and childbirth in Luanda, Angola. Ten focus group discussions were conducted and data were analysed using grounded theory. Women were found to apply six strategies as they "endeavored to cope with demands for unauthorized user fees" (core category): (i) blowing the whistle,

Picosecond X-ray diffraction studies of laser-excited acoustic phonons in InSb

We have employed time-resolved X-ray diffraction with picosecond temporal resolution to measure the time-dependent rocking curves of laser-irradiated asymmetrically cut single InSb crystals. Coherent acoustic phonons were excited in the crystals by irradiation with 800-nm, 100-fs laser pulses at irradiances between 0.25 and 12 mJ/cm(2). The induced time-dependent strain profiles (corresponding to

Visual sensitivity in the crepuscular owl butterfly Caligo memnon and the diurnal blue morpho Morpho peleides: a clue to explain the evolution of nocturnal apposition eyes?

Insects active in dim light, such as moths and many beetles, normally have superposition compound eyes to increase photon capture. But there are nocturnal and crepuscular insects - such as some species of bees, wasps and butterflies - that have apposition compound eyes. These are likely to have adaptations - including large eye and facet size and coarsened spatial and temporal resolution - that im

Type 1 diabetes risk analysis on dried blood spot samples from population-based newborns: design and feasibility of an unselected case-control study

Development of type 1 diabetes mellitus (T1D) may be triggered pre- or perinatally by multiple factors. Identifying new predisposing T1D markers or combinations of markers in a large, well-characterised case-control collection may be important for future T1D prevention. The present work describes the design and feasibility of a large and unselected case-control study, which will define and evaluat

Enhanced concentration of COMP (cartilage oligomeric matrix protein) in osteochondral fractures from racing Thoroughbreds

The aim of the present study was to correlate the levels of COMP and aggrecan as indicators of tissue damage, in synovial fluid (sf) from carpal joints of acutely lame racehorses, with macroscopical lesions of articular cartilage (OA). osteochondral fractures and ligament tears found at arthroscopy. Sixty-three lame horses [49 Standardbred trotters (STB) and 14 Thoroughbreds (TB)] in conventional

Inhibition of cerebrospinal fluid formation by omeprazole

Omeprazole, a specific inhibitor of H(+)-K(+)-activated ATPase, gave a dose-dependent inhibition of CSF production as determined by cerebroventriculocisternal perfusions in the rabbit. The reduction was 35% when the perfusate concentration of omeprazole was 10(-6) M and 25% after an intravenous dose of 0.2 mg/kg of omeprazole, respectively. A similarly substituted benzimidazol (H178/42) without H(

Rewritable Reference Attributed Grammars

This paper presents an object-oriented technique for rewriting abstract syntax trees in order to simplify compilation. The technique, Rewritable Reference Attributed Grammars (ReRAGs), is completely declarative and supports both rewrites and computations by means of attributes. We have implemented ReRAGs in our aspect-oriented compiler compiler tool JastAdd II. Our largest application is a complet

Total Parenteral Nutrition Causes Circumferential Intestinal Atrophy, Remodeling of the Intestinal Wall, and Redistribution of Eosinophils in the Rat Gastrointestinal Tract.

Total parenteral nutrition (TPN) is held to cause intestinal atrophy and weaken mechanical and immunological barriers. To monitor the degree of atrophy caused by TPN, female Sprague-Dawley rats were, for 8 days, maintained on TPN (n = 6) and compared to identically housed controls given food and water ad libitum (n = 6). Specimens from jejunum, ileum, and colon were taken for histology and morphom

Calculation of EPR g tensors for transition-metal complexes based on multiconfigurational perturbation theory (CASPT2)

The computation of the electronic g tensor by two multireference methods is presented and applied to a selection of molecules including CN, BO, AIO, GaO, InO, ZnH, ZnF, O-2, H2O+, O-3(-), and H2CO+ (group A) as well as TiF3, CuCl42-, Cu(NH3)(4)(2+) and a series of d(1)-MOX4n- compounds, with M = V Cr, Mo, Tc, W, Re and X = F Cl, Br (group B). Two approaches are considered, namely, one in which spi

Heart rate variability and intima media thickness

Increased activity in the sympathetic nervous system is part of the physiological stress response and is expressed in the heart rate variability (HRV). The objective of this study was to examine associations of HRV and intima media thickness (IMT). In 2002, satisfactory measurements of HRV of 78 voluntary participants were made, both during a stress test and during sleep. IMT in 2002 and the progr