Showing papers by "University of Rhode Island published in 2012"
Dalhousie University1, University of Saskatchewan2, University of Rhode Island3, Sewanee: The University of the South4, Natural History Museum5, New York State Department of Health6, University of British Columbia7, Kaiserslautern University of Technology8, Charles University in Prague9, University of Guelph10, Le Moyne College11, Georgia College & State University12, University of Colorado Boulder13, University of Geneva14, Edinburgh Napier University15, University of Arkansas16, Saint Petersburg State University17
TL;DR: This revision of the classification of eukaryotes retains an emphasis on the protists and incorporates changes since 2005 that have resolved nodes and branches in phylogenetic trees.
Abstract: This revision of the classification of eukaryotes, which updates that of Adl et al. [J. Eukaryot. Microbiol. 52 (2005) 399], retains an emphasis on the protists and incorporates changes since 2005 that have resolved nodes and branches in phylogenetic trees. Whereas the previous revision was successful in re-introducing name stability to the classification, this revision provides a classification for lineages that were then still unresolved. The supergroups have withstood phylogenetic hypothesis testing with some modifications, but despite some progress, problematic nodes at the base of the eukaryotic tree still remain to be statistically resolved. Looking forward, subsequent transformations to our understanding of the diversity of life will be from the discovery of novel lineages in previously under-sampled areas and from environmental genomic information.
1,414 citations
Plant Genome Mapping Laboratory1, Iowa State University2, Joint Genome Institute3, Commonwealth Scientific and Industrial Research Organisation4, Mississippi State University5, Brigham Young University6, Agricultural Research Service7, University of Rhode Island8, Federal University of Rio de Janeiro9, J. Craig Venter Institute10, Northeast Normal University11, University of California, Davis12, Bayer13, University of Georgia14, North Carolina State University15, Empresa Brasileira de Pesquisa Agropecuária16, Cotton Incorporated17, National Institute for Biotechnology and Genetic Engineering18, West Virginia State University19, Hebrew University of Jerusalem20, Texas A&M University21, Central Institute for Cotton Research22, Texas Tech University23, Nanjing Agricultural University24
TL;DR: It is shown that an abrupt five- to sixfold ploidy increase approximately 60 million years (Myr) ago, and allopolyploidy reuniting divergent Gossypium genomes approximately 1–2 Myr ago, conferred about 30–36-fold duplication of ancestral angiosperm genes in elite cottons, genetic complexity equalled only by Brassica among sequenced angiosperms.
Abstract: Polyploidy often confers emergent properties, such as the higher fibre productivity and quality of tetraploid cottons than diploid cottons bred for the same environments. Here we show that an abrupt five- to sixfold ploidy increase approximately 60 million years (Myr) ago, and allopolyploidy reuniting divergent Gossypium genomes approximately 1-2 Myr ago, conferred about 30-36-fold duplication of ancestral angiosperm (flowering plant) genes in elite cottons (Gossypium hirsutum and Gossypium barbadense), genetic complexity equalled only by Brassica among sequenced angiosperms. Nascent fibre evolution, before allopolyploidy, is elucidated by comparison of spinnable-fibred Gossypium herbaceum A and non-spinnable Gossypium longicalyx F genomes to one another and the outgroup D genome of non-spinnable Gossypium raimondii. The sequence of a G. hirsutum A(t)D(t) (in which 't' indicates tetraploid) cultivar reveals many non-reciprocal DNA exchanges between subgenomes that may have contributed to phenotypic innovation and/or other emergent properties such as ecological adaptation by polyploids. Most DNA-level novelty in G. hirsutum recombines alleles from the D-genome progenitor native to its New World habitat and the Old World A-genome progenitor in which spinnable fibre evolved. Coordinated expression changes in proximal groups of functionally distinct genes, including a nuclear mitochondrial DNA block, may account for clusters of cotton-fibre quantitative trait loci affecting diverse traits. Opportunities abound for dissecting emergent properties of other polyploids, particularly angiosperms, by comparison to diploid progenitors and outgroups.
1,015 citations
TL;DR: This work shows that total microbial cell abundance in subseafloor sediment varies between sites by ca.
Abstract: The global geographic distribution of subseafloor sedimentary microbes and the cause(s) of that distribution are largely unexplored. Here, we show that total microbial cell abundance in subseafloor sediment varies between sites by ca. five orders of magnitude. This variation is strongly correlated with mean sedimentation rate and distance from land. Based on these correlations, we estimate global subseafloor sedimentary microbial abundance to be 2.9⋅1029 cells [corresponding to 4.1 petagram (Pg) C and ∼0.6% of Earth’s total living biomass]. This estimate of subseafloor sedimentary microbial abundance is roughly equal to previous estimates of total microbial abundance in seawater and total microbial abundance in soil. It is much lower than previous estimates of subseafloor sedimentary microbial abundance. In consequence, we estimate Earth’s total number of microbes and total living biomass to be, respectively, 50–78% and 10–45% lower than previous estimates.
791 citations
TL;DR: A high-order adaptive time-stepping TVD solver for the fully nonlinear Boussinesq model of Chen (2006), extended to include moving reference level as in Kennedy et al. (2001).
486 citations
TL;DR: In this paper, the economic value of oyster reef services, excluding oyster harvesting, is estimated to be between $5500 and $99,000 per hectare per year and reefs recover their median restoration costs in 2-14 years.
Abstract: Valuation of ecosystem services can provide evidence of the importance of sustaining and enhancing those resources and the ecosystems that provide them. Long appreciated only as a commercial source of oysters, oyster reefs are now acknowledged for the other services they provide, such as enhancing water quality and stabilizing shorelines. We develop a framework to assess the value of these services. We conservatively estimate that the economic value of oyster reef services, excluding oyster harvesting, is between $5500 and $99,000 per hectare per year and that reefs recover their median restoration costs in 2–14 years. In contrast, when oyster reefs are subjected to destructive oyster harvesting, they do not recover the costs of restoration. Shoreline stabilization is the most valuable potential service, although this value varies greatly by reef location. Quantifying the economic values of ecosystem services provides guidance about when oyster reef restoration is a good use of funds.
450 citations
Journal Article•
28 Oct 2012TL;DR: A comprehensive review of the literature was conducted with findings consistently indicating academic deficits associated with ADHD in college students, with limited studies limited by lack of controlled investigations, use of small samples, and lack of confirmation of diagnostic status.
Abstract: Approximately 2 to 8% of the college population reports clinically significant levels of ADHD symptomatology and at least 25% of college students with disabilities are diagnosed with ADHD. A comprehensive review of the literature was conducted with findings consistently indicating academic deficits associated with ADHD in college students. It is less clear whether this disorder significantly impacts social, psychological, and neuropsychological functioning. Although several self- and parent-report measures have been developed for this population, very few studies of assessment methods have been conducted. Similarly, no controlled studies of psychopharmacological, psychosocial, or educational interventions have been completed in samples of college students with ADHD. Non-prescribed use (i.e., diversion) of stimulant medication is a growing problem with approximately 7% of college students reporting this behavior. Studies, to date, are limited by lack of controlled investigations, use of small samples, and lack of confirmation of diagnostic status. Comprehensive and methodologically sound investigations are needed, especially regarding treatment, to promote the success of students with ADHD in higher education settings.
377 citations
Rutgers University1, Sungkyunkwan University2, Bigelow Laboratory For Ocean Sciences3, University of Düsseldorf4, University of Cologne5, University of Rhode Island6, Canadian Institute for Advanced Research7, University of New Brunswick8, Université de Montréal9, Martin Luther University of Halle-Wittenberg10, Max F. Perutz Laboratories11, Colorado School of Mines12, Centre national de la recherche scientifique13, University of Provence14, University of Freiburg15, University of Iowa16, University of British Columbia17, University of California, Berkeley18
TL;DR: Draft genome and transcriptome data from the basally diverging alga Cyanophora paradoxa are analyzed and provide evidence for a single origin of the primary plastid in the eukaryote supergroup Plantae.
Abstract: The primary endosymbiotic origin of the plastid in eukaryotes more than 1 billion years ago led to the evolution of algae and plants. We analyzed draft genome and transcriptome data from the basally diverging alga Cyanophora paradoxa and provide evidence for a single origin of the primary plastid in the eukaryote supergroup Plantae. C. paradoxa retains ancestral features of starch biosynthesis, fermentation, and plastid protein translocation common to plants and algae but lacks typical eukaryotic light-harvesting complex proteins. Traces of an ancient link to parasites such as Chlamydiae were found in the genomes of C. paradoxa and other Plantae. Apparently, Chlamydia-like bacteria donated genes that allow export of photosynthate from the plastid and its polymerization into storage polysaccharide in the cytosol.
372 citations
National Oceanography Centre, Southampton1, Texas A&M University2, Tohoku University3, University of Bristol4, Ocean Drilling Program5, University of California, Davis6, University of Leicester7, Stockholm University8, University of Paris9, University College London10, University of New Orleans11, University of Florida12, Goethe University Frankfurt13, University of California, Santa Cruz14, National Institute of Oceanography, India15, Imperial College London16, University of Birmingham17, Cardiff University18, Lamont–Doherty Earth Observatory19, University of Münster20, Hokkaido University21, Leibniz Institute of Marine Sciences22, Shimane University23, University of Kiel24, Indiana University of Pennsylvania25, Japan Agency for Marine-Earth Science and Technology26, Ibaraki University27, Kōchi University28, Rice University29, University of Michigan30, University of Otago31, University of Louisiana at Lafayette32, University of Rhode Island33, Spanish National Research Council34, University of South Carolina35, Pennsylvania State University36, Utrecht University37, Pusan National University38, Tongji University39, University of Leeds40, University of Bremen41, University of Hawaii at Manoa42, National Institute of Advanced Industrial Science and Technology43
TL;DR: A carbonate accumulation record that covers the past 53 million years from a depth transect in the equatorial Pacific Ocean is presented and large superimposed fluctuations in carbonate compensation depth are found during the middle and late Eocene.
Abstract: Atmospheric carbon dioxide concentrations and climate are regulated on geological timescales by the balance between carbon input from volcanic and metamorphic outgassing and its removal by weathering feedbacks; these feedbacks involve the erosion of silicate rocks and organic-carbon-bearing rocks. The integrated effect of these processes is reflected in the calcium carbonate compensation depth, which is the oceanic depth at which calcium carbonate is dissolved. Here we present a carbonate accumulation record that covers the past 53 million years from a depth transect in the equatorial Pacific Ocean. The carbonate compensation depth tracks long-term ocean cooling, deepening from 3.0-3.5 kilometres during the early Cenozoic (approximately 55 million years ago) to 4.6 kilometres at present, consistent with an overall Cenozoic increase in weathering. We find large superimposed fluctuations in carbonate compensation depth during the middle and late Eocene. Using Earth system models, we identify changes in weathering and the mode of organic-carbon delivery as two key processes to explain these large-scale Eocene fluctuations of the carbonate compensation depth.
322 citations
01 Jan 2012
TL;DR: This chapter describes the Gaussian random process, the subject of this chapter, which has many important properties that have been inherited from those of the N-dimensional Gaussian PDF, which was discussed in Section 14.3.
Abstract: There are several types of random processes that have found wide application because of their realistic physical modeling yet relative mathematical simplicity. In this and the next two chapters we describe these important random processes. They are the Gaussian random process, the subject of this chapter; the Poisson random process, described in Chapter 21; and the Markov chain, described in Chapter 22. Concentrating now on the Gaussian random process, we will see that it has many important properties. These properties have been inherited from those of the N-dimensional Gaussian PDF, which was discussed in Section 14.3.
314 citations
TL;DR: A new approach is applied—the d:l-amino-acid model—to quantify the distributions and turnover times of living microbial biomass, endospores and microbial necromass, as well as to determine their role in the sub-seafloor carbon budget.
Abstract: Two decades of scientific ocean drilling have demonstrated widespread microbial life in deep sub-seafloor sediment, and surprisingly high microbial-cell numbers. Despite the ubiquity of life in the deep biosphere, the large community sizes and the low energy fluxes in this vast buried ecosystem are not yet understood. It is not known whether organisms of the deep biosphere are specifically adapted to extremely low energy fluxes or whether most of the observed cells are in a dormant, spore-like state. Here we apply a new approach--the D:L-amino-acid model--to quantify the distributions and turnover times of living microbial biomass, endospores and microbial necromass, as well as to determine their role in the sub-seafloor carbon budget. The approach combines sensitive analyses of unique bacterial markers (muramic acid and D-amino acids) and the bacterial endospore marker, dipicolinic acid, with racemization dynamics of stereo-isomeric amino acids. Endospores are as abundant as vegetative cells and microbial activity is extremely low, leading to microbial biomass turnover times of hundreds to thousands of years. We infer from model calculations that biomass production is sustained by organic carbon deposited from the surface photosynthetic world millions of years ago and that microbial necromass is recycled over timescales of hundreds of thousands of years.
296 citations
TL;DR: In this article, the performance of silicon thin film electrodes was investigated in the presence of anode solid electrolyte interphase (SEI) forming additives, such as Vinylene Carbonate (VC), flouroethylene carbonate (FEC), and lithium difluorooxalatoborate (LiFOB), which improved the cycling efficiency and capacity retention of cells.
Abstract: The cycling performance of silicon thin film electrodes was investigated in the presence of anode solid electrolyte interphase (SEI) forming additives. Incorporation of vinylene carbonate (VC), flouroethylene carbonate (FEC), and lithium difluorooxalatoborate (LiFOB) improve the cycling efficiency and capacity retention of cells. Ex-situ surface analysis of the silicon anodes after cycling indicates that incorporation of the additives changes the structure of the SEI. Additives decrease the concentration of LiF on the anode surface consistent with inhibition of LiPF6 decomposition. The changes in surface structure correlate with improved cycling performance.
TL;DR: Data demonstrate that diatom P deficiency results in changes in cellular P allocation through polyphosphate production, increased P transport, a switch to utilization of dissolved organic P through increased production of metalloenzymes, and a remodeling of the cell surface through production of sulfolipids.
Abstract: Phosphorus (P) is a critical driver of phytoplankton growth and ecosystem function in the ocean. Diatoms are an abundant class of marine phytoplankton that are responsible for significant amounts of primary production. With the control they exert on the oceanic carbon cycle, there have been a number of studies focused on how diatoms respond to limiting macro and micronutrients such as iron and nitrogen. However, diatom physiological responses to P deficiency are poorly understood. Here, we couple deep sequencing of transcript tags and quantitative proteomics to analyze the diatom Thalassiosira pseudonana grown under P-replete and P-deficient conditions. A total of 318 transcripts were differentially regulated with a false discovery rate of <0.05, and a total of 136 proteins were differentially abundant (p<0.05). Significant changes in the abundance of transcripts and proteins were observed and coordinated for multiple biochemical pathways, including glycolysis and translation. Patterns in transcript and protein abundance were also linked to physiological changes in cellular P distributions, and enzyme activities. These data demonstrate that diatom P deficiency results in changes in cellular P allocation through polyphosphate production, increased P transport, a switch to utilization of dissolved organic P through increased production of metalloenzymes, and a remodeling of the cell surface through production of sulfolipids. Together, these findings reveal that T. pseudonana has evolved a sophisticated response to P deficiency involving multiple biochemical strategies that are likely critical to its ability to respond to variations in environmental P availability.
TL;DR: Polyethylene (PE)-water equilibrium partitioning constants, K(PEw), were reviewed for trace hydrophobic organic contaminants (HOCs) and a critical review of diffusivities in PE suggests that best results are obtained when using the film-stacking method.
Abstract: Polyethylene (PE)-water equilibrium partitioning constants, KPEw, were reviewed for trace hydrophobic organic contaminants (HOCs). Relative standard deviations were <30% for phenanthrene, anthracene, fluoranthene, and pyrene implying excellent reproducibility of KPEw across laboratories and PE sources. Averaged KPEw values of various HOCs were best correlated with aqueous solubility, logCwsat(L): logKPEw = −0.99(±0.029)logCwsat(L) + 2.39(±0.096) (r2 = 0.92, SE = 0.35, n = 100). For 80% of analytes, this equation predicted logKPEw within a factor of 2. A first-order estimation of KPEw can be obtained assuming constant solubility of the compounds in the PE, such that the variation in Cwsat(L) determines the differences in KPEw. For PE samplers, KPEw values do not change with the thickness of the PE sampler. The influence of temperature on KPEw seems dominated by solubility-changes of the compound in water, not in PE. The effect of salt is rather well understood, using a Schetschenow-style approach. The air-...
TL;DR: Evidence is presented that challenges the importance of pelvic morphology and mechanics in the evolution of human gestation and altriciality and suggests that limits to maternal metabolism are the primary constraints on human gestation length and fetal growth.
Abstract: The classic anthropological hypothesis known as the “obstetrical dilemma” is a well-known explanation for human altriciality, a condition that has significant implications for human social and behavioral evolution. The hypothesis holds that antagonistic selection for a large neonatal brain and a narrow, bipedal-adapted birth canal poses a problem for childbirth; the hominin “solution” is to truncate gestation, resulting in an altricial neonate. This explanation for human altriciality based on pelvic constraints persists despite data linking human life history to that of other species. Here, we present evidence that challenges the importance of pelvic morphology and mechanics in the evolution of human gestation and altriciality. Instead, our analyses suggest that limits to maternal metabolism are the primary constraints on human gestation length and fetal growth. Although pelvic remodeling and encephalization during hominin evolution contributed to the present parturitional difficulty, there is little evidence that pelvic constraints have altered the timing of birth.
University of Rhode Island1, Dalhousie University2, Federal Fluminense University3, University of Massachusetts Dartmouth4, University of Minnesota5, University of Concepción6, University of Manchester7, University of British Columbia8, McGill University9, Academia Sinica10, ETH Zurich11, University of Basel12, University of Bordeaux13, University of California, Santa Cruz14, University of Hamburg15, University of Victoria16, Oklahoma State University–Stillwater17, Oregon State University18, University of Kiel19, Stanford University20, Hokkaido University21, Rutgers University22, University of South Carolina23, Xiamen University24
TL;DR: In this paper, a >100 point comparison of sediment trap and surface sedimentary nitrogen isotope values demonstrates that, at sites located off of the continental margins, an increase in sediment 15N/14N occurs during early burial, likely at the seafloor.
Abstract: Key Points: Use of sedimentary nitrogen isotopes is examined; On average, sediment 15N/14N increases approx. 2 per mil during early burial; Isotopic alteration scales with water depth
Abstract:
Nitrogen isotopes are an important tool for evaluating past biogeochemical cycling from the paleoceanographic record. However, bulk sedimentary nitrogen isotope ratios, which can be determined routinely and at minimal cost, may be altered during burial and early sedimentary diagenesis, particularly outside of continental margin settings. The causes and detailed mechanisms of isotopic alteration are still under investigation. Case studies of the Mediterranean and South China Seas underscore the complexities of investigating isotopic alteration. In an effort to evaluate the evidence for alteration of the sedimentary N isotopic signal and try to quantify the net effect, we have compiled and compared data demonstrating alteration from the published literature. A >100 point comparison of sediment trap and surface sedimentary nitrogen isotope values demonstrates that, at sites located off of the continental margins, an increase in sediment 15N/14N occurs during early burial, likely at the seafloor. The extent of isotopic alteration appears to be a function of water depth. Depth-related differences in oxygen exposure time at the seafloor are likely the dominant control on the extent of N isotopic alteration. Moreover, the compiled data suggest that the degree of alteration is likely to be uniform through time at most sites so that bulk sedimentary isotope records likely provide a good means for evaluating relative changes in the global N cycle.
TL;DR: In this paper, the authors applied high-throughput computational methods to rapidly explore thousands of possible MOFs, given a library of starting materials, in the context of Xe/Kr separation.
Abstract: Metal–organic frameworks (MOFs) are porous crystals with the potential to improve many industrial gas separation processes Because there is a practically unlimited number of different MOFs, which vary in their pore geometry and chemical composition, it is challenging to find the best MOF for a given application Here, we applied high-throughput computational methods to rapidly explore thousands of possible MOFs, given a library of starting materials, in the context of Xe/Kr separation We generated over 137 000 structurally diverse hypothetical MOFs from a library of chemical building blocks and screened them for Xe/Kr separation For each MOF, we calculated geometric properties via Delaunay tessellation and predicted thermodynamic Xe/Kr adsorption behavior via multicomponent grand canonical Monte Carlo simulations Specifically, we calculated the pore limiting diameter, largest cavity diameter, accessible void volume, as well as xenon and krypton adsorption at 10, 50 and 10 bar at 273 K From these data we show that MOFs with pores just large enough to fit a single xenon atom, and having morphologies resembling tubes of uniform width, are ideal for Xe/Kr separation Finally, we compare our generated MOFs to several known structures (IRMOF-1, HKUST-1, ZIF-8, Pd-MOF, & MOF-505) and conclude that significantly improved materials remain to be synthesized All crystal structure files are freely available for download and browsing in an online database
TL;DR: In this article, the authors measured olivine-hosted melt inclusions from a single eruption of Agrigan volcano, Marianas, in order to test the influence of differentiation processes vs. source conditions on the Fe{sup 3+}/{Sigma}Fe ratio, a proxy for system oxygen fugacity.
TL;DR: This paper presents the detailed design architecture and its associated learning algorithm to explain how effective learning and optimization can be achieved in this new ADP architecture and test the performance both on the cart-pole balancing task and the triple-link inverted pendulum balancing task.
TL;DR: A semistochastic implementation of the power method to compute, for very large matrices, the dominant eigenvalue and expectation values involving the corresponding eigenvector using the Monte Carlo method.
Abstract: We introduce a semistochastic implementation of the power method to compute, for very large matrices, the dominant eigenvalue and expectation values involving the corresponding eigenvector. The method is semistochastic in that the matrix multiplication is partially implemented numerically exactly and partially stochastically with respect to expectationvalues only. Compared to a fully stochastic method, the semistochastic approach significantly reduces the computational time required to obtain the eigenvalue to a specified statistical uncertainty. This is demonstrated by the application of the semistochastic quantum Monte Carlo method to systems with a sign problem: the fermion Hubbard model and the carbon dimer. Introduction.—Consider the computation of the domi- nant eigenvalue of an NN matrix, with N so large that the matrix cannot be stored. Transformation methods can- not be used in this case, but one can still proceed with the power method, also known as the projection method, as long as one can compute and store the result of multi- plication of an arbitrary vector by the matrix. When, for sufficiently large N, this is no longer feasible, Monte Carlo methods can be used to represent stochastically both the vector and multiplication by the matrix. This suffices to implement the power method to compute the dominant eigenvalue and averages involving its corresponding eigenvector. In this Letter, we propose a hybrid method consisting of numerically exact representation and multiplication in a small deterministic subspace, complemented by stochastic treatment of the rest of the space. This semistochastic projection method combines the advantages of both approaches: it greatly reduces the statistical uncertainty of averages relative to purely stochastic projection while allowing N to be large. These advantages are realized if one succeeds in choosing a deterministic subspace that carries a substantial fraction of the total spectral weight of the dominant eigenstate. Semistochastic projection has numerous potential applications: transfer matrix (1) and quantum Monte Carlo (QMC) (2-4) calculations, respectively for classical statistical mechanical and quantum mechanical systems, and the calculation of subdominant eigenvalues (5).
02 Sep 2012
TL;DR: These prospective, longitudinal findings demonstrate diminished prematurity effects at adolescence in peer friendship behavior and reveal interpersonal dyadic processes that are important to peer group affiliation and other areas of competence.
Abstract: Close friendships become important at middle-school age and are unexplored in adolescents born prematurely. The study aimed to characterize friendship behaviors of formerly preterm infants at age 12 and explore similarities and differences between preterm and full-term peers on dyadic friendship types. From the full sample of N=186, one hundred sixty-six 12-year-old adolescents (40 born full term, 126 born preterm) invited a close friend to a 1.5 hour videotaped laboratory play session. Twenty adolescents were unable to participate due to scheduling conflicts or developmental disability. Characteristic friendship behaviors were identified by Q-sort followed by Q-factoring analysis. Friendship duration, age, and contact differed between the full-term and preterm groups but friendship activities, behaviors, and quality were similar despite school service use. Three Q-factors, leadership, distancing, and mutual playfulness, were most characteristic of all dyads, regardless of prematurity. These prospective, longitudinal findings demonstrate diminished prematurity effects at adolescence in peer friendship behavior and reveal interpersonal dyadic processes that are important to peer group affiliation and other areas of competence.
TL;DR: In social work, evidence-based practice (EBP) is increasingly embraced as a decision-making process that incorporates the best available evidence about effective treatments given client values and pre-existing evidence.
Abstract: Social work is increasingly embracing evidence-based practice (EBP) as a decision-making process that incorporates the best available evidence about effective treatments given client values and pre...
TL;DR: Modeling showed that the rate of respiration of specific carbon decreased as a function of sediment depth, that is, its age, indicating that aerobic metabolism can persist in deep marine sediments and indicated that the community size is controlled by the rates of carbon oxidation and thereby by the low available energy flux.
Abstract: Living microbes have been discovered many meters into marine sediments. On a cruise in the North Pacific Gyre, Roy et al. (p. [922][1]) discovered that oxygen occurred for tens of meters into the sediment. The bacteria living in these sediments were respiring the oxygen but at a slower rate than the supply of organic material dropping out of the water column, allowing these ancient deep marine sediments to remain oxygenated. Modeling showed that the rate of respiration of specific carbon decreased as a function of sediment depth, that is, its age. Thus aerobic metabolism can persist in deep marine sediments.
[1]: /lookup/doi/10.1126/science.1219424
TL;DR: The combined results show that the ultra-oligotrophic SPG harbors a hitherto unknown heterotrophic diazotrophic community, clearly distinct from other oceanic gyres previously visited.
Abstract: Oceanic subtropical gyres are considered biological deserts because of the extremely low availability of nutrients and thus minimum productivities. The major source of nutrient nitrogen in these ecosystems is N2-fixation. The South Pacific Gyre (SPG) is the largest ocean gyre in the world, but measurements of N2-fixation therein, or identification of microorganisms involved, are scarce. In the 2006/2007 austral summer, we investigated nitrogen and carbon assimilation at 11 stations throughout the SPG. In the ultra-oligotrophic waters of the SPG, the chlorophyll maxima reached as deep as 200 m. Surface primary production seemed limited by nitrogen, as dissolved inorganic carbon uptake was stimulated upon additions of 15N-labeled ammonium and leucine in our incubation experiments. N2-fixation was detectable throughout the upper 200 m at most stations, with rates ranging from 0.001 to 0.19 nM N h−1. N2-fixation in the SPG may account for the production of 8–20% of global oceanic new nitrogen. Interestingly, comparable 15N2-fixation rates were measured under light and dark conditions. Meanwhile, phylogenetic analyses for the functional gene biomarker nifH and its transcripts could not detect any common photoautotrophic diazotrophs, such as, Trichodesmium, but a prevalence of γ-proteobacteria and the unicellular photoheterotrophic Group A cyanobacteria. The dominance of these likely heterotrophic diazotrophs was further verified by quantitative PCR. Hence, our combined results show that the ultra-oligotrophic SPG harbors a hitherto unknown heterotrophic diazotrophic community, clearly distinct from other oceanic gyres previously visited.
Rhode Island Hospital1, University of Puerto Rico2, University of Rhode Island3, University of Delaware4, University of Connecticut5, University of California, Los Angeles6, Texas Christian University7, Temple University8, University of Kentucky9, Arizona State University10, National Development and Research Institutes11
TL;DR: Addressing inadequate knowledge and negative attitudes about MAT may increase its adoption, but better linkages to community pharmacotherapy during the reentry period might overcome other issues, including security, liability, staffing, and regulatory concerns.
Abstract: Medication-assisted treatment (MAT) is underutilized in the treatment of drug-dependent, criminal justice populations. This study surveyed criminal justice agencies affiliated with the Criminal Justice Drug Abuse Treatment Studies (CJ-DATS) to assess use of MAT and factors influencing use of MAT. A convenience sample (N = 50) of criminal justice agency respondents (e.g., jails, prisons, parole/probation, and drug courts) completed a survey on MAT practices and attitudes. Pregnant women and individuals experiencing withdrawal were most likely to receive MAT for opiate dependence in jail or prison, whereas those reentering the community from jail or prison were the least likely to receive MAT. Factors influencing use of MAT included criminal justice preferences for drug-free treatment, limited knowledge of the benefits of MAT, security concerns, regulations prohibiting use of MAT for certain agencies, and lack of qualified medical staff. Differences across agency type in the factors influencing use and perceptions of MAT were also examined. MAT use is largely limited to detoxification and maintenance of pregnant women in criminal justice settings. Use of MAT during the community reentry period is minimal. Addressing inadequate knowledge and negative attitudes about MAT may increase its adoption, but better linkages to community pharmacotherapy during the reentry period might overcome other issues, including security, liability, staffing, and regulatory concerns. The CJ-DATS collaborative MAT implementation study to address inadequate knowledge, attitudes, and linkage will be described.
TL;DR: In this article, the authors quantified the charge lost per unit surface area of a silicon electrode due to the formation of a solid-electrolyte-interphase (SEI) layer during initial lithiation, and the species that constitute this layer were identified.
TL;DR: It is demonstrated that the anti-bacterial performance of AgNPs at selected natural water conditions decreases in the presence of dissolved natural organic matter or divalent ions, such as humic acid and calcium carbonate.
TL;DR: It is discussed how PRN structure and its system-level properties could determine both individual performance and patterns of physiological evolution, as well as how evolutionary change is constrained by interactions within PRNs.
Abstract: Ecological and evolutionary physiology has traditionally focused on one aspect of physiology at a time. Here, we discuss the implications of considering physiological regulatory networks (PRNs) as integrated wholes, a perspective that reveals novel roles for physiology in organismal ecology and evolution. For example, evolutionary response to changes in resource abundance might be constrained by the role of dietary micronutrients in immune response regulation, given a particular pathogen environment. Because many physiological components impact more than one process, organismal homeostasis is maintained, individual fitness is determined and evolutionary change is constrained (or facilitated) by interactions within PRNs. We discuss how PRN structure and its system-level properties could determine both individual performance and patterns of physiological evolution.
TL;DR: Subsequent to Roux-en-Y gastric bypass, patients display markedly changed eating behaviour and meal patterns, which may lead to sustained weight loss.
Abstract: Little is known about eating behaviour and meal pattern subsequent to Roux-en-Y gastric bypass (RYGB), knowledge important for the nutritional care process. The objective of the study was to obtain basic information of how meal size, eating rate, meal frequency and eating behaviour change upon the RYGB surgery. Voluntary chosen meal size and eating rate were measured in a longitudinal, within subject, cohort study of 43 patients, 31 women and 12 men, age 42.6 (s.d. 9.7) years, body mass index (BMI) 44.5 (4.9) kg m−2. Thirty-one non-obese subjects, 37.8 (13.6) years, BMI 23.7 (2.7) kg m−2 served as a reference group. All subjects completed a meal pattern questionnaire and the Three-Factor Eating Questionnaire (TFEQ-R21). Six weeks postoperatively meal size was 42% of the preoperative meal size, (P<0.001). After 1 and 2 years, meal size increased but was still lower than preoperative size 57% (P<0.001) and 66% (P<0.001), respectively. Mean meal duration was constant before and after surgery. Mean eating rate measured as amount consumed food per minute was 45% of preoperative eating rate 6 weeks postoperatively (P<0.001). After 1 and 2 years, eating rate increased to 65% (P<0.001) and 72% (P<0.001), respectively, of preoperative rate. Number of meals per day increased from 4.9 (95% confidence interval, 4.4,5.4) preoperatively to 6 weeks: 5.2 (4.9,5.6), (not significant), 1 year 5.8 (5.5,6.1), (P=0.003), and 2 years 5.4 (5.1,5.7), (not significant). Emotional and uncontrolled eating were significantly decreased postoperatively, (both P<0.001 at all-time points), while cognitive restraint was only transiently increased 6 weeks postoperatively (P=0.011). Subsequent to RYGB, patients display markedly changed eating behaviour and meal patterns, which may lead to sustained weight loss.
TL;DR: In this article, the authors proposed a direct solar thermal collector that harnesses the localized surface plasmon of metallic nanoparticles suspended in water, where four types of gold-nanoshell particles were blended in the aquatic solution.
Abstract: The present study reports a novel concept of a direct solar thermal collector that harnesses the localized surface plasmon of metallic nanoparticles suspended in water. At the plasmon resonance frequency, the absorption and scattering from the nanoparticle can be greatly enhanced via the coupling of the incident radiation with the collective motion of electrons in metal. However, the surface plasmon induces strong absorption with a sharp peak due to its resonant nature, which is not desirable for broad-band solar absorption. In order to achieve the broad-band absorption, we propose a direct solar thermal collector that has four types of gold-nanoshell particles blended in the aquatic solution. Numerical simulations based on the Monte Carlo algorithm and finite element analysis have shown that the use of blended plasmonic nanofluids can significantly enhance the solar collector efficiency with an extremely low particle concentration (e.g., approximately 70% for a 0.05% particle volume fraction). The low particle concentration ensures that nanoparticles do not significantly alter the flow characteristics of nanofluids inside the solar collector. The results obtained from this study will facilitate the development of highly efficient solar thermal collectors using plasmonic nanofluids. [DOI: 10.1115/1.4005756]
TL;DR: The role of nuclear factor erythoid 2–related factor 2 (Nrf2) in the pathogenesis of hepatic steatosis, insulin resistance, obesity, and type 2 diabetes is determined and Keap1 and Nrf2 impact HFD-induced obesity is determined.
Abstract: The study herein determined the role of nuclear factor erythoid 2–related factor 2 (Nrf2) in the pathogenesis of hepatic steatosis, insulin resistance, obesity, and type 2 diabetes. Lepob/ob-Keap1-knockdown (KD) mice, which have increased Nrf2 activity, were generated. Markers of obesity and type 2 diabetes were measured in C57Bl/6J, Keap1-KD, Lepob/ob, and Lepob/ob-Keap1-KD mice. Lepob/ob-Keap1-KD mice exhibited less lipid accumulation, smaller adipocytes, decreased food intake, and reduced lipogenic gene expression. Enhanced Nrf2 activity impaired insulin signaling, prolonged hyperglycemia in response to glucose challenge, and induced insulin resistance in Lepob/ob background. Nrf2 augmented hepatic steatosis and increased lipid deposition in liver. Next, C57Bl/6J and Keap1-KD mice were fed a high-fat diet (HFD) to determine whether Keap1 and Nrf2 impact HFD-induced obesity. HFD-induced obesity and lipid accumulation in white adipose tissue was decreased in Keap1-KD mice. Nrf2 activation via Keap1-KD or sulforaphane suppressed hormone-induced differentiation and decreased peroxisome proliferator–activated receptor-γ, CCAAT/enhancer–binding protein α, and fatty acid–binding protein 4 expression in mouse embryonic fibroblasts. Constitutive Nrf2 activation inhibited lipid accumulation in white adipose tissue, suppressed adipogenesis, induced insulin resistance and glucose intolerance, and increased hepatic steatosis in Lepob/ob mice.