Optimal experience and personal growth. Flow and the consolidation of place identity

This study examined the relationship between flow experience and place identity, based on eudaimonistic identity theory (EIT) which prioritizes self-defining activities as important for an individual's identification of his/her goals, values, beliefs, and interests corresponding to one's own identity development or enhancement. This study focuses on place identity, the identity's features relating to a person's relation with her/his place. The study is also based on flow theory, according to which some salient features of an activity experience are important for happiness and well-being. Questionnaire surveys on Italian and Greek residents focused on their perceived flow and place identity in relation to their own specific local place experiences. The overall findings revealed that flow experience occurring in one's own preferred place is widely reported as resulting from a range of self-defining activities, irrespective of gender or age, and it is positively and significantly associated with one's own place identity. Such findings provide the first quantitative evidence about the link between flow experienced during meaningfully located self-defining activities and identity experienced at the place level, similarly to the corresponding personal and social levels that had been previously already empirically tested. Results are also discussed in terms of their implications for EIT's understanding and enrichment, especially by its generalization from the traditional, personal identity level up to that of place identity. More generally, this study has implications for maintaining or enhancing one's own place identity, and therefore people place relations, by means of facilitating a person's flow experience within psychologically meaningful place

Liana litter decomposes faster than tree litter in a multispecies and multisite experiment

1. Lianas account for a small fraction of forest biomass, but their contribution to leaf or litter biomass and thus to food webs can be substantial. Globally liana exhibit fast life-history traits. Thus, liana litter may decompose faster than tree litter, and could enhance the decomposition of tree litter (complementarity effect). The differences in decomposition may also vary with mesofauna access or across forest communities. The contribution of these factors to nutrient biogeochemical cycling is poorly understood. 2. We examined the decomposition of litter of 20 liana and 20 tree species of three different tropical forest communities in southern China, over 1 year. (i) We incubated the litter in bags with coarse and fine mesh to distinguish mesofaunal and microfaunal effects. (ii) We used single-species litter bags to compare decomposition rates of lianas and trees, to test which functional traits best explained decomposition, and whether those traits differed between lianas and trees, and among forest types. (iv) We used mixed-species litter bags to test whether liana litter enhances decomposition in litter mixtures. (v) We evaluated how leaf litter nutrients decayed in relation to litter mass. 3. Litter decayed faster in coarse-mesh than fine-mesh bags, but there was no interaction effect with forest type or growth form. Liana litter decayed faster than tree litter in single-species bags with mesofauna access and in mixed bags (liana-only mix, tree-only mix) without mesofauna. Lianas had higher nitrogen content and specific leaf area and lower leaf dry matter content (LDMC) and toughness than trees. Decomposition rate was significantly negatively related to LDMC. Litter of evergreen broadleaved forest decomposed slower than that of other forest types. Liana litter did not enhance the decomposition of tree litter in mixtures. Liana litter released calcium slightly faster than trees. 4. Synthesis: Leaf litter decomposes faster for lianas than trees, despite high variability of traits and decomposition rates within each growth form and overlap between growth forms, and we found no evidence for the complementarity hypothesis. Our study sheds light on the potential role of lianas within brown food webs and their importance on terrestrial biogeochemistry

Restriction of HIV-1 Genotypes in Breast Milk Does Not Account for the Population Transmission Genetic Bottleneck That Occurs following Transmission

BACKGROUND. Breast milk transmission of HIV-1 remains a major route of pediatric infection. Defining the characteristics of viral variants to which breastfeeding infants are exposed is important for understanding the genetic bottleneck that occurs in the majority of mother-to-child transmissions. The blood-milk epithelial barrier markedly restricts the quantity of HIV-1 in breast milk, even in the absence of antiretroviral drugs. The basis of this restriction and the genetic relationship between breast milk and blood variants are not well established. METHODOLOGY/PRINCIPAL FINDINGS. We compared 356 HIV-1 subtype C gp160 envelope (env) gene sequences from the plasma and breast milk of 13 breastfeeding women. A trend towards lower viral population diversity and divergence in breast milk was observed, potentially indicative of clonal expansion within the breast. No differences in potential N-linked glycosylation site numbers or in gp160 variable loop amino acid lengths were identified. Genetic compartmentalization was evident in only one out of six subjects in whom contemporaneously obtained samples were studied. However, in samples that were collected 10 or more days apart, six of seven subjects were classified as having compartmentalized viral populations, highlighting the necessity of contemporaneous sampling for genetic compartmentalization studies. We found evidence of CXCR4 co-receptor using viruses in breast milk and blood in nine out of the thirteen subjects, but no evidence of preferential localization of these variants in either tissue. CONCLUSIONS/SIGNIFICANCE. Despite marked restriction of HIV-1 quantities in milk, our data indicate intermixing of virus between blood and breast milk. Thus, we found no evidence that a restriction in viral genotype diversity in breast milk accounts for the genetic bottleneck observed following transmission. In addition, our results highlight the rapidity of HIV-1 env evolution and the importance of sample timing in analyses of gene flow.National Institute of Child Health and Human Development; National Institutes of Health (R01 HD 39611, R01 HD 40777); International Maternal Pediatric Adolescent AIDS Clinical Trials Group (U01 AI068632-01); National Institutes of Health Cellular, Biochemical; Molecular Sciences Training Program Grant (T 32 067587

Geochemistry and mineralogy of the phonolite lava lake, Erebus volcano, Antarctica: 1972–2004 and comparison with older lavas

Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Volcanology and Geothermal Research 177 (2008): 589-605, doi:10.1016/j.jvolgeores.2007.11.025.Mount Erebus, Antarctica, is a large (3794 m) alkaline open-conduit stratovolcano that hosts a vigorously convecting and persistently degassing lake of anorthoclase phonolite magma. The composition of the lake was investigated by analyzing glass and mineral compositions in lava bombs erupted between 1972 and 2004. Matrix glass, titanomagnetite, olivine, clinopyroxene, and fluor-apatite compositions are invariant and show that the magmatic temperature (~1000°C) and oxygen fugacity (ΔlogFMQ = -0.9) have been stable. Large temperature variations at the lake surface (ca. 400 - 500°C) are not reflected in mineral compositions. Anorthoclase phenocrysts up to 10 cm in length feature a restricted compositional range (An10.3-22.9Ab62.8-68.1Or11.4-27.2) with complex textural and compositional zoning. Anorthoclase textures and compositions indicate crystallization occurs at low degrees of effective undercooling. We propose shallow water exsolution causes crystallization to occur and shallow convection repeats this process multiple times, yielding extremely large anorthoclase crystals. Minor variations in eruptive activity from 1972 to 2004 are decoupled from magma compositions. The variations probably relate to changes in conduit geometry within the volcano and/or variable input of CO2-rich volatiles into the upper-level magma chamber from deeper in the system. Eleven bulk samples of phonolite lava from the summit plateau that range in age from 0 ± 4 ka to 17 ± 8 ka were analyzed for major and trace elements. Small compositional variations are controlled by anorthoclase content. The lavas are indistinguishable from modern bulk lava bomb compositions and demonstrate that Erebus volcano has been erupting lava and tephra from the summit region with the same bulk composition for ~17 ka.The work at Erebus volcano and the continued operation of the Mount Erebus Volcano Observatory is supported by grants (OPP-0229305, ANT-0538414) from the Office of Polar Programs, National Science Foundation

Breast milk and in utero transmission of HIV-1 select for envelope variants with unique molecular signatures

Additional file 5: Figure S5. Representative CD4 infectivity curves using Affinofile cells for IUT (top) and BMT (bottom) maternal–infant pairs. Affinofile cells were induced to generate a 100-fold range of CD4 surface density (ABS/cell) and infected with 2000 IU pseudotyped virus. Percent infection was measured as the percent luciferase relative to infected and maximally induced Affinofile cells. Data shown are representative curves among 3–4 experimental replicates

4E10-Resistant HIV-1 Isolated from Four Subjects with Rare Membrane-Proximal External Region Polymorphisms

Human antibody 4E10 targets the highly conserved membrane-proximal external region (MPER) of the HIV-1 transmembrane glycoprotein, gp41, and has extraordinarily broad neutralizing activity. It is considered by many to be a prototype for vaccine development. In this study, we describe four subjects infected with viruses carrying rare MPER polymorphisms associated with resistance to 4E10 neutralization. In one case resistant virus carrying a W680G substitution was transmitted from mother to infant. We used site-directed mutagenesis to demonstrate that the W680G substitution is necessary for conferring the 4E10-resistant phenotype, but that it is not sufficient to transfer the phenotype to a 4E10-sensitive Env. Our third subject carried Envs with a W680R substitution causing variable resistance to 4E10, indicating that residues outside the MPER are required to confer the phenotype. A fourth subject possessed a F673L substitution previously associated with 4E10 resistance. For all three subjects with W680 polymorphisms, we observed additional residues in the MPER that co-varied with position 680 and preserved charged distributions across this region. Our data provide important caveats for vaccine development targeting the MPER. Naturally occurring Env variants described in our study also represent unique tools for probing the structure-function of HIV-1 envelope

Genomic characterization of chronic lymphocytic leukemia (CLL) in radiation-exposed Chornobyl cleanup workers

Background Chronic lymphocytic leukemia (CLL) was the predominant leukemia in a recent study of Chornobyl cleanup workers from Ukraine exposed to radiation (UR-CLL). Radiation risks of CLL significantly increased with increasing bone marrow radiation doses. Current analysis aimed to clarify whether the increased risks were due to radiation or to genetic mutations in the Ukrainian population. Methods A detailed characterization of the genomic landscape was performed in a unique sample of 16 UR-CLL patients and age- and sex-matched unexposed general population Ukrainian-CLL (UN-CLL) and Western-CLL (W-CLL) patients (n = 28 and 100, respectively). Results Mutations in telomere-maintenance pathway genes POT1 and ATM were more frequent in UR-CLL compared to UN-CLL and W-CLL (both p < 0.05). No significant enrichment in copy-number abnormalities at del13q14, del11q, del17p or trisomy12 was identified in UR-CLL compared to other groups. Type of work performed in the Chornobyl zone, age at exposure and at diagnosis, calendar time, and Rai stage were significant predictors of total genetic lesions (all p < 0.05). Tumor telomere length was significantly longer in UR-CLL than in UN-CLL (p = 0.009) and was associated with the POT1 mutation and survival. Conclusions No significant enrichment in copy-number abnormalities at CLL-associated genes was identified in UR-CLL compared to other groups. The novel associations between radiation exposure, telomere maintenance and CLL prognosis identified in this unique case series provide suggestive, though limited data and merit further investigation

J/psi suppression at forward rapidity in Au+Au collisions at sqrt(s_NN)=39 and 62.4 GeV

We present measurements of the J/psi invariant yields in sqrt(s_NN)=39 and 62.4 GeV Au+Au collisions at forward rapidity (1.2<|y|<2.2). Invariant yields are presented as a function of both collision centrality and transverse momentum. Nuclear modifications are obtained for central relative to peripheral Au+Au collisions (R_CP) and for various centrality selections in Au+Au relative to scaled p+p cross sections obtained from other measurements (R_AA). The observed suppression patterns at 39 and 62.4 GeV are quite similar to those previously measured at 200 GeV. This similar suppression presents a challenge to theoretical models that contain various competing mechanisms with different energy dependencies, some of which cause suppression and others enhancement.Comment: 365 authors, 10 pages, 11 figures, 4 tables. Submitted to Phys. Rev. C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm