Prokaryotic assemblages and metagenomes in pelagic zones of the South China Sea

Background: Prokaryotic microbes, the most abundant organisms in the ocean, are remarkably diverse. Despite numerous studies of marine prokaryotes, the zonation of their communities in pelagic zones has been poorly delineated. By exploiting the persistent stratification of the South China Sea (SCS), we performed a 2-year, large spatial scale (10, 100, 1000, and 3000 m) survey, which included a pilot study in 2006 and comprehensive sampling in 2007, to investigate the biological zonation of bacteria and archaea using 16S rRNA tag and shotgun metagenome sequencing. Results: Alphaproteobacteria dominated the bacterial community in the surface SCS, where the abundance of Betaproteobacteria was seemingly associated with climatic activity. Gammaproteobacteria thrived in the deep SCS, where a noticeable amount of Cyanobacteria were also detected. Marine Groups II and III Euryarchaeota were predominant in the archaeal communities in the surface and deep SCS, respectively. Bacterial diversity was higher than archaeal diversity at all sampling depths in the SCS, and peaked at mid-depths, agreeing with the diversity pattern found in global water columns. Metagenomic analysis not only showed differential %GC values and genome sizes between the surface and deep SCS, but also demonstrated depth-dependent metabolic potentials, such as cobalamin biosynthesis at 10 m, osmoregulation at 100 m, signal transduction at 1000 m, and plasmid and phage replication at 3000 m. When compared with other oceans, urease at 10 m and both exonuclease and permease at 3000 m were more abundant in the SCS. Finally, enriched genes associated with nutrient assimilation in the sea surface and transposase in the deep-sea metagenomes exemplified the functional zonation in global oceans. Conclusions: Prokaryotic communities in the SCS stratified with depth, with maximal bacterial diversity at mid-depth, in accordance with global water columns. The SCS had functional zonation among depths and endemically enriched metabolic potentials at the study site, in contrast to other oceans

Taking people to water instead of taking water to people: changes in Ghana's rural water sector

The paper highlights key issues emerging from a “conversion programme”, the Accompanying Measures Eastern Region (AMER) Project, during which over 150 hand-pumps previously centrally-managed and maintained by government (the 3000 Wells Project), were transferred to rural communities for ownership and management (COM). Implementation was carried out in the Eastern Region of Ghana between 1996 and 2001. To ease the burden on communities to make the transition “transfer-friendly”, communities could pay 50% of arrears owed over six months for the rest to be written off, local residents were trained for maintenance of facilities and there was free rehabilitation of the hand-pumps. Even though some challenges were encountered, there were interesting findings such as the long time it takes for COM to take root in rural communities towards sustainability, the need to make alternative arrangements for maintenance of facilities and the complex relationships between socio-cultural configurations and payment of arrears

Anaerobic microbial communities and their potential for bioenergy production in heavily biodegraded petroleum reservoirs

Most of the oil in low temperature, non‐uplifted reservoirs is biodegraded due to millions of years of microbial activity, including via methanogenesis from crude oil. To evaluate stimulating additional methanogenesis in already heavily biodegraded oil reservoirs, oil sands samples were amended with nutrients and electron acceptors, but oil sands bitumen was the only organic substrate. Methane production was monitored for over 3000 days. Methanogenesis was observed in duplicate microcosms that were unamended, amended with sulfate or that were initially oxic, however methanogenesis was not observed in nitrate‐amended controls. The highest rate of methane production was 0.15 μmol CH4 g−1 oil d−1, orders of magnitude lower than other reports of methanogenesis from lighter crude oils. Methanogenic Archaea and several potential syntrophic bacterial partners were detected following the incubations. GC–MS and FTICR–MS revealed no significant bitumen alteration for any specific compound or compound class, suggesting that the very slow methanogenesis observed was coupled to bitumen biodegradation in an unspecific manner. After 3000 days, methanogenic communities were amended with benzoate resulting in methanogenesis rates that were 110‐fold greater. This suggests that oil‐to‐methane conversion is limited by the recalcitrant nature of oil sands bitumen, not the microbial communities resident in heavy oil reservoirs

Responding to the Victorian Bushfires: What Role for Philanthropy?

In February 2009, due to record temperatures and a prolonged heatwave, several firestorms merged and raged across the state of Victoria, culminating in Australia's worst natural disaster in recorded history. The fires were catastrophic, covering over 400,000 hectares and leaving behind over 200 fatalities, hundreds injured, and over 7,000 homeless

“I just want to be skinny.”: A content analysis of tweets expressing eating disorder symptoms

There is increasing concern about online communities that promote eating disorder (ED) behaviors through messages and/or images that encourage a “thin ideal” (i.e., promotion of thinness as attractive) and harmful weight loss/weight control practices. The purpose of this paper is to assess the content of body image and ED-related content on Twitter and provide a deeper understanding of EDs that may be used for future studies and online-based interventions. Tweets containing ED or body image-related keywords were collected from January 1-January 31, 2015 (N = 28,642). A random sample (n = 3000) was assessed for expressions of behaviors that align with subscales of the Eating Disorder Examination (EDE) 16.0. Demographic characteristics were inferred using a social media analytics company. The comprehensive research that we conducted indicated that 2,584 of the 3,000 tweets were ED-related; 65% expressed a preoccupation with body shape, 13% displayed issues related to food/eating/calories, and 4% expressed placing a high level of importance on body weight. Most tweets were sent by girls (90%) who were ≤19 years old (77%). Our findings stress a need to better understand if and how ED-related content on social media can be used for targeting prevention and intervention messages towards those who are in-need and could potentially benefit from these efforts.</div

The Response of Consumption in Russian Households to Economic Shocks

This paper examines the extent to which consumption in Russian households responds to exogenous income shocks. During the time period studied in this paper (1994 - 1998), Russia experienced two major economic crises. Both featured extreme movements in the real ruble-dollar exchange rate. The price of oil, which is typically thought to have a strong effect on the Russian economy, was also quite volatile during this time period. This paper exploits these large changes in oil prices and exchange rates, as well as community-level variations in wage and pension arrears, to identify exogenous shocks to household income. Using representative panel data on urban households from the Russian Longitudinal Monitoring Survey, I find that a household which experiences an exogenous shock of 10% of its total income changes both its food and total non-durable expenditure by 7-11%. Most evidence indicates that these shocks are transitory in nature and thus the traditional Life Cycle/Permanent Income Hypothesis model is firmly rejected as describing the behavior of Russian households. Additional results indicate that changes in household savings are negatively related to exogenous income shocks, with this relationship strongest for low wealth households. Only models of consumption which include precautionary savings motives can explain why poorer households both reduce their consumption and increase their savings in response to an exogenous decline in income.http://deepblue.lib.umich.edu/bitstream/2027.42/39796/3/wp412.pd

Community-based Immunization Strategies for Epidemic Control

Understanding the epidemic dynamics, and finding out efficient techniques to control it, is a challenging issue. A lot of research has been done on targeted immunization strategies, exploiting various global network topological properties. However, in practice, information about the global structure of the contact network may not be available. Therefore, immunization strategies that can deal with a limited knowledge of the network structure are required. In this paper, we propose targeted immunization strategies that require information only at the community level. Results of our investigations on the SIR epidemiological model, using a realistic synthetic benchmark with controlled community structure, show that the community structure plays an important role in the epidemic dynamics. An extensive comparative evaluation demonstrates that the proposed strategies are as efficient as the most influential global centrality based immunization strategies, despite the fact that they use a limited amount of information. Furthermore, they outperform alternative local strategies, which are agnostic about the network structure, and make decisions based on random walks.Comment: 6 pages, 7 figure

Ancient China and its Eurasian Neighbors: Artifacts, Identity, and Death in the Frontier, 3000-700 BCE

This volume examines the role of objects in the region north of early dynastic state centers, at the intersection of Ancient China and Eurasia, a large area that stretches from Xinjiang to the China Sea, from c.3000 BCE to the mid-eighth century BCE. This area was a frontier, an ambiguous space that lay at the margins of direct political control by the metropolitan states, where local and colonial ideas and practices were reconstructed transculturally. These identities were often merged and displayed in material culture. Types of objects, styles, and iconography were often hybrids or new to the region, as were the tomb assemblages in which they were deposited and found. Patrons commissioned objects that marked a symbolic vision of place and person and that could mobilize support, legitimize rule, and bind people together. Through close examination of key artifacts, this book untangles the considerable changes in political structure and cultural makeup of ancient Chinese states and their northern neighbors.https://cupola.gettysburg.edu/books/1138/thumbnail.jp

Characterization of Navassa National Wildlife Refuge: A preliminary report for NF-06-05 (NOAA ship "Nancy Foster", April 18-30, 2006)

Navassa is a small, undeveloped island in the Windward Passage between Jamaica and Haiti. It was designated a National Wildlife Refuge under the jurisdiction of the U.S. Fish and Wildlife Service in 1999, but the remote location makes management and enforcement challenging, and the area is regularly fished by artisanal fishermen from Haiti. In April 2006, the NOAA Center for Coastal Fisheries and Habitat Research conducted a research cruise to Navassa. The cruise produced the first high-resolution multibeam bathymetry for the area, which will facilitate habitat mapping and assist in refuge management. A major emphasis of the cruise was to study the impact of Haitian fishing gear on benthic habitats and fish communities; however, in 10 days on station only one small boat was observed with five fishermen and seven traps. Fifteen monitoring stations were established to characterize fish and benthic communities along the deep (28-34 m) shelf, as these areas have been largely unstudied by previous cruises. The fish communities included numerous squirrelfishes, triggerfishes, and parrotfishes. Snappers and grouper were also present but no small individuals were observed. Similarly, conch surveys indicated the population was in low abundance and was heavily skewed towards adults. Analysis of the benthic photoquadrats is currently underway. Other cruise activities included installation of a temperature logger network, sample collection for stable isotope analyses to examine trophic structure, and drop camera surveys to ground-truth habitat maps and overhead imagery. (PDF contains 58 pages