Does Facial Resemblance Enhance Cooperation?

Facial self-resemblance has been proposed to serve as a kinship cue that facilitates cooperation between kin. In the present study, facial resemblance was manipulated by morphing stimulus faces with the participants'' own faces or control faces (resulting in self-resemblant or other-resemblant composite faces). A norming study showed that the perceived degree of kinship was higher for the participants and the self-resemblant composite faces than for actual first-degree relatives. Effects of facial self-resemblance on trust and cooperation were tested in a paradigm that has proven to be sensitive to facial trustworthiness, facial likability, and facial expression. First, participants played a cooperation game in which the composite faces were shown. Then, likability ratings were assessed. In a source memory test, participants were required to identify old and new faces, and were asked to remember whether the faces belonged to cooperators or cheaters in the cooperation game. Old-new recognition was enhanced for self-resemblant faces in comparison to other-resemblant faces. However, facial self-resemblance had no effects on the degree of cooperation in the cooperation game, on the emotional evaluation of the faces as reflected in the likability judgments, and on the expectation that a face belonged to a cooperator rather than to a cheater. Therefore, the present results are clearly inconsistent with the assumption of an evolved kin recognition module built into the human face recognition system.     

Spectral trees as a robust annotation tool in LC–MS based metabolomics

The identification of large series of metabolites detectable by mass spectrometry (MS) in crude extracts is a challenging task. In order to test and apply the so-called multistage mass spectrometry (MS ⁿ ) spectral tree approach as tool in metabolite identification in complex sample extracts, we firstly performed liquid chromatography (LC) with online electrospray ionization (ESI)?CMS ⁿ , using crude extracts from both tomato fruit and Arabidopsis leaf. Secondly, the extracts were automatically fractionated by a NanoMate LC-fraction collector/injection robot (Advion) and selected LC-fractions were subsequently analyzed using nanospray-direct infusion to generate offline in-depth MS ⁿ spectral trees at high mass resolution. Characterization and subsequent annotation of metabolites was achieved by detailed analysis of the MS ⁿ spectral trees, thereby focusing on two major plant secondary metabolite classes: phenolics and glucosinolates. Following this approach, we were able to discriminate all selected flavonoid glycosides, based on their unique MS ⁿ fragmentation patterns in either negative or positive ionization mode. As a proof of principle, we report here 127 annotated metabolites in the tomato and Arabidopsis extracts, including 21 novel metabolites. Our results indicate that online LC?CMS ⁿ fragmentation in combination with databases of in-depth spectral trees generated offline can provide a fast and reliable characterization and annotation of metabolites present in complex crude extracts such as those from plants.     

Bio-samtools: Ruby bindings for SAMtools, a library for accessing BAM files containing high-throughput sequence alignments

ABSTRACT: BACKGROUND: The SAMtools utilities comprise a very useful and widely used suite of software for manipulating files and alignments in the SAM and BAM format, used in a wide range of genetic analyses. The SAMtools utilities are implemented in C and provide an API for programmatic access, to help make this functionality available to programmers wishing to develop in the high level Ruby language we have developed bio-samtools, a Ruby binding to the SAMtools library. RESULTS: The utility of SAMtools is encapsulated in 3 main classes, Bio::DB::Sam, representing the alignment files and providing access to the data in them, Bio::DB::Alignment, representing the individual read alignments inside the files and Bio::DB::Pileup, representing the summarised nucleotides of reads over a single point in the nucleotide sequence to which the reads are aligned. CONCLUSIONS: bio-samtools is a flexible and easy to use interface that programmers of many levels of experience can use to access the information in the popular and common SAM/BAM format.     

Gain, preservation, and loss of a group 1a coronavirus accessory glycoprotein

Coronaviruses are positive-strand RNA viruses of extraordinary genetic complexity and diversity. In addition to a common set of genes for replicase and structural proteins, each coronavirus may carry multiple group-specific genes apparently acquired through relatively recent heterologous recombination events. Here we describe an accessory gene, ORF3, unique to canine coronavirus type I (CCoV-I) and characterize its product, glycoprotein gp3. Whereas ORF3 is conserved in CCoV-I, only remnants remain in CCoV-II and CCoV-II-derived porcine and feline coronaviruses. Our findings provide insight into the evolutionary history of coronavirus group 1a and into the dynamics of gain and loss of accessory genes.     

Stem respiration and carbon dioxide efflux of young <Emphasis Type="Italic">Populus deltoides</Emphasis> trees in relation to temperature and xylem carbon dioxide concentration

Oxidative respiration is strongly temperature driven. However, in woody stems, efflux of CO₂ to the atmosphere (E _A), commonly used to estimate the rate of respiration (R _S), and stem temperature (T _st) have often been poorly correlated, which we hypothesized was due to transport of respired CO₂ in xylem sap, especially under high rates of sap flow (f _s). To test this, we measured E _A, T _st, f _s and xylem sap CO₂ concentrations ([CO₂*]) in 3-year-old Populus deltoides trees under different weather conditions (sunny and rainy days) in autumn. We also calculated R _S by mass balance as the sum of both outward and internal CO₂ fluxes and hypothesized that R _S would correlate better with T _st than E _A. We found that E _A sometimes correlated well with T _st, but not on sunny mornings and afternoons or on rainy days. When the temperature effect on E _A was accounted for, a clear positive relationship between E _A and xylem [CO₂*] was found. [CO₂*] varied diurnally and increased substantially at night and during periods of rain. Changes in [CO₂*] were related to changes in f _s but not T _st. We conclude that changes in both respiration and internal CO₂ transport altered E _A. The dominant component flux of R _S was E _A. However, on a 24-h basis, the internal transport flux represented 9–18% and 3–7% of R _S on sunny and rainy days, respectively, indicating that the contribution of stem respiration to forest C balance may be larger than previously estimated based on E _A measurements. Unexpectedly, the relationship between R _S and T _st was sometimes weak in two of the three trees. We conclude that in addition to temperature, other factors such as water deficits or substrate availability exert control on the rate of stem respiration so that simple temperature functions are not sufficient to predict stem respiration.     

Dimers of light-harvesting complex 2 from Rhodobacter sphaeroides characterized in reconstituted 2D crystals with atomic force microscopy

Microscopic and light spectroscopic investigations on the supramolecular architecture of bacterial photosynthetic membranes have revealed the photosynthetic protein complexes to be arranged in a densely packed energy-transducing network. Protein packing may play a determining role in the formation of functional photosynthetic domains and membrane curvature. To further investigate in detail the packing effects of like-protein photosynthetic complexes, we report an atomic force microscopy investigation on artificially created 2D crystals of the peripheral photosynthetic light-harvesting complexes 2 (LH2's) from the bacterium Rhodobacter sphaeroides. Instead of the usually observed one or two different crystallization lattices for one specific preparation protocol, we find seven different packing lattices. The most abundant crystal types all show a tilting of LH2. Most surprisingly, although LH2 is a monomeric protein complex in vivo, we find an LH2 dimer packing motif. We further characterize two different dimer configurations: in type 1, the LH2's are tilted inwards, and in type 2, they are tilted outwards. Closer inspection of the lattices surrounding the LH2 dimers indicates their close resemblance to those LH2's that constitute a lattice of zig-zagging LH2's. In addition, analyses of the tilt of the LH2's within the zig-zag lattice and that observed within the dimers corroborate their similar packing motifs. The type 2 dimer configuration exhibits a tilt that, in the absence of up-down packing, could bend the lipid bilayer, leading to the strong curvature of the LH2 domains as observed in Rhodobacter sphaeroides photosynthetic membranes in vivo.     

Landscape composition and spatial prediction of alveolar echinococcosis in southern Ningxia, China

Background

Alveolar echinococcosis (AE) presents a serious public health challenge within China. Mass screening ultrasound surveys can detect pre-symptomatic AE, but targeting areas identified from hospital records is inefficient regarding AE. Prediction of undetected or emerging hotspots would increase detection rates. Voles and lemmings of the subfamily Arvicolinae are important intermediate hosts in sylvatic transmission systems. Their populations reach high densities in productive grasslands where food and cover are abundant. Habitat availability is thought to affect arvicoline population dynamic patterns and definitive host–intermediate host interactions. Arvicoline habitat correlates with AE prevalence in Western Europe and southern Gansu Province, China.

Methods and Findings

Xiji County, Ningxia Hui Autonomous Region, borders southern Gansu. The aims of this study were to map AE prevalence across Xiji and test arvicoline habitat as a predictor. Land cover was mapped using remotely sensed (Landsat) imagery. Infection status of 3,205 individuals screened in 2002–2003 was related, using generalised additive mixed models, to covariates: gender; farming; ethnicity; dog ownership; water source; and areal cover of mountain pasture and lowland pasture. A Markov random field modelled additional spatial variation and uncertainty. Mountain pasture and lowland pasture were associated with below and above average AE prevalence, respectively.

Conclusions

Low values of the normalised difference vegetation index indicated sub-optimality of lowland pasture for grassland arvicolines. Unlike other known endemic areas, grassland arvicolines probably did not provide the principal reservoir for Echinococcus multilocularis in Xiji. This result is consistent with recent small mammal surveys reporting low arvicoline densities and high densities of hamsters, pikas and jerboas, all suitable intermediate hosts for E. multilocularis, in reforested lowland pasture. The risk of re-emergence is discussed. We recommend extending monitoring to: southern Haiyuan County, where predicted prevalence was high; southern Xiji County, where prediction uncertainty was high; and monitoring small mammal community dynamics and the infection status of dogs.     

Peters Plus syndrome is a new congenital disorder of glycosylation and involves defective Omicron-glycosylation of thrombospondin type 1 repeats

Peters Plus syndrome is an autosomal recessive disorder characterized by anterior eye chamber defects, disproportionate short stature, developmental delay, and cleft lip and/or palate. It is caused by splice site mutations in what was thought to be a beta1,3-galactosyltransferase-like gene (B3GALTL). Recently, we and others found this gene to encode a beta1,3-glucosyltransferase involved in the synthesis of the disaccharide Glc-beta1,3-Fuc-Omicron-that occurs on thrombospondin type 1 repeats of many biologically important proteins. No functional tests have been performed to date on the presumed glycosylation defect in Peters Plus syndrome. We have established a sensitive immunopurification-mass spectrometry method, using multiple reaction monitoring, to analyze Omicron-fucosyl glycans. It was used to compare the reporter protein properdin from Peters Plus patients with that from control heterozygous relatives. In properdin from patients, we could not detect the Glc-beta1,3-Fuc-Omicron-disaccharide, and we only found Fuc-Omicron-at all four Omicron-fucosylation sites. In contrast, properdin from heterozygous relatives and a healthy volunteer carried the Glc-beta1,3-Fuc-Omicron-disaccharide. These data firmly establish Peters Plus syndrome as a new congenital disorder of glycosylation.     

Photosynthetic, Physiological and Biochemical Responses of Tomato Plants to Polyethylene Glycol-Induced Water Deficit

Polyethylene glycol （PEG 6000）-induced water deficit causes physiological as well as biochemical changes in plants. The present study reports on the results of such changes in hydroponically grown tomato plants （Lycopersicon esculentum Mill. cv. Nikita）. Plants were subjected to moderate and severe levels of water stress （i.e. water potentials in the nutrient solution of- 0.51 and -1.22 MPa, respectively）. Water stress markedly affected the parameters of gas exchange. Net photosynthetic rate （Pn） decreased with the induction of water stress. Accordingly, a decrease in the transpiration rate （E） was observed. The ratio of both （Pn/E） resulted in a decrease in water use efficiency. One of the possible reasons for the reduction in Pn is structural damage to the thylakoids, which affects the photosynthetic transport of electrons. This was indicated by an increase in non-photochemical quenching and a reduction in the quantum yield of photosystem Ⅱ. Furthermore, a decrease in both leaf water potential and leaf osmotic potential was observed, which resulted in a significant osmotic adjustment during stress conditions. Analysis of the physiological responses was complemented with a study on changes in proline content. In stressed plants, a 10-fold increase in proline content was detected compared with control plants. It is clear that water stress tolerance is the result of a cumulative action of various physiological and biochemical processes, all of which were affected by PEG 6000-induced water stress.     

Brca2 (XRCC11) Deficiency Results in Radioresistant DNA Synthesis and a Higher Frequency of Spontaneous Deletions

We show here that the radiosensitive Chinese hamster cell mutant (V-C8) of group XRCC11 is defective in the breast cancer susceptibility gene Brca2. The very complex phenotype of V-C8 cells is complemented by a single human chromosome 13 providing the BRCA2 gene, as well as by the murine Brca2 gene. The Brca2 deficiency in V-C8 cells causes hypersensitivity to various DNA-damaging agents with an extreme sensitivity toward interstrand DNA cross-linking agents. Furthermore, V-C8 cells show radioresistant DNA synthesis after ionizing radiation, suggesting that Brca2 deficiency affects cell cycle checkpoint regulation. In addition, V-C8 cells display tremendous chromosomal instability and a high frequency of abnormal centrosomes. The mutation spectrum at the hprt locus showed that the majority of spontaneous mutations in V-C8 cells are deletions, in contrast to wild-type V79 cells. A mechanistic explanation for the genome instability phenotype of Brca2-deficient cells is provided by the observation that the nuclear localization of the central DNA repair protein in homologous recombination, Rad51, is reduced in V-C8 cells.