Collagen gels are widely used in experiments on cell mechanics because they mimic the extracellular matrix in physiological conditions. Collagen gels are often characterized by their bulk rheology; however, variations in the collagen fiber microstructure and cell adhesion forces cause the mechanical properties to be inhomogeneous at the cellular scale....
The data is a JSON format file containing the position, velocity, and fish identifier data for 300 golden shiners in a shallow (depth of 4.5 to 5 cm) rectangular water tank (2.1 by 1.2 meters). There are 5000 individual frames (samples of position and velocity) corresponding to video taken at...
Tuna management in the Western and Central Pacific (WCP) is complicated given the dynamic and sometimes conflicting interests of participating countries and actors exploiting the tuna resource in the region. Pacific Island Countries (PICs) through the Fisheries Forum Agency (FFA) and the Parties to the Nauru Agreement (PNA) have developed a...
We use the NCEP/NCAR Reanalysis (NCEP)
and the MPI/ECHAM5 general circulation model to drive
the RegCM3 regional climate model to assess the ability of
the models to reproduce the spatiotemporal aspects of the
Pacific-North American teleconnection (PNA) pattern.
Composite anomalies of the NCEP-driven RegCM3 simulations
for 1982–2000 indicate that the...
In this thesis I present the results of a comprehensive assessment of the Pacific-North American (PNA) teleconnection pattern in general circulation models (GCMs) and a regional climate model (RCM). The PNA teleconnection pattern is a quasi-stationary wave field over the North Pacific and North America that has long been recognized...
In the Pacific Ocean, the total catch of skipjack tuna has been increasing rapidly. Then, eight of Polynesian, Melanesian, and Micronesian countries (PNA countries) have concluded a cooperative management of tuna fisheries. Although those countries do not catch a large amount by themselves, the main migrating area is included in...
Phytophthora infestans is a destructive plant pathogen best known
for causing the disease that triggered the Irish potato famine and
remains the most costly potato pathogen to manage worldwide.
Identification of P. infestan’s elusive center of origin is critical to
understanding the mechanisms of repeated global emergence of
this pathogen....
Tuna fisheries provides an important source of income, foreign exchange and employment for many Pacific Island States. It is also seen as a major avenue for industrial development by most Pacific Island States. The Law of the Sea Convention, while recognising the rights of coastal States to manage and develop...
The Western Central Pacific Fishery Commission (WCPFC) was inaugurated in 2004 after a preparatory process which commenced in 1996. Scientific advice is that skipjack stocks are in good condition, but bigeye and yellowfin stocks are being exploited too heavily and reductions of effort are needed to avoid overfishing. Compared to...
A high-spectral resolution laser-excited molecular fluorescence
system was developed that utilizes a pulsed supersonic expansion to
simplify the fluorescence excitation spectra of large, gas-phase
aromatic molecules diluted in an excess of a monatomic gas. A
microcomputer was used to control and synchronize the instrumental
components, which included a Chromatix CMX-4...
Spectrometric detection systems for gas chromatography
(GC) based on gas phase ultraviolet absorbance
and fluorescence measurements have been developed and
evaluated in this research. Polynuclear aromatic compounds
(PNAs) are selectively detected by these systems.
Limits of detection for PNAs range from 4 ng to 90 ng
for absorbance determinations, and...
The high accumulation rate and negligible amount of melt at Eclipse Icefield (3017 m) in the Saint Elias Range of Yukon, Canada, allows for the preservation of a high-resolution isotopic and glaciochemical records valuable for reconstruction of climatic variables. Each of the three Eclipse ice cores have a well-constrained depth–age...
Cold-season storms are responsible for generating most of the snow that accumulates in mountainous watersheds across the western United States, but with overwhelming evidence of warming temperature trends, this seasonal snowpack is at risk for melt, The vast majority of snow trend studies utilize undifferentiated air temperature records – these...
Dissolved organic matter (DOM) in the oceans is one of the largest pools of reduced carbon on Earth, comparable in size to the atmospheric CO₂ reservoir. A vast number of compounds are present in DOM, and they play important roles in all major element cycles, contribute to the storage of...
The most diverse marine ecosystems, coral reefs, depend upon a functional symbiosis between a cnidarian animal host (the coral) and intracellular photosynthetic dinoflagellate algae. The molecular and cellular mechanisms underlying this endosymbiosis are not well understood, in part because of the difficulties of experimental work with corals. The small sea...
Identifying the ecological and evolutionary mechanisms that determine biological diversity is a central question in ecology. In microbial ecology, phylogenetic diversity is an increasingly common and relevant means of quantifying community diversity, particularly given the challenges in defining unambiguous species units from environmental sequence data. We explore patterns of phylogenetic...
Radiation damage caused by fission fragments to metal surfaces is an important research topic. Thin titanium foils were irradiated with a continuous wave beam of 132 MeV ¹³²Xe+²⁹ at the current intensity of 2 pnA. Pre- and post-irradiated surface topologies were investigated using atomic force microscopy and the observed defects...
Climate change, combined with population growth, is expected to exacerbate water scarcity globally. In the Columbia River basin (CRB), streamflow is managed for multiple objectives with a network of dams and reservoirs distributed throughout the basin that may mitigate climate change effects on water scarcity. This study quantified trends in...
Since 1958 when Alfred C. Redfield (1) recognized the similarity between the ratios of elements in living biomass and those dissolved in the surrounding seawater, we have understood that microorganisms largely control the concentrations, distribution, and molecular makeup of nutritional resources in the ocean. The primary elemental ingredients for life,...
Microstructure changes in uranium and uranium/metal alloys due to radiation damage are of great interest in nuclear science and engineering. Titanium has attracted attention because of its similarity to Zr. It has been proposed for use in the second generation of fusion reactors due to its resistance to radiation-induced swelling....
Using national crop and livestock production records from 1961–2003 and satellite-derived data on pasture greenness from 1982–2003 we show that the productivity of crops, livestock, and pastures in Africa is predictably associated with the El Niño Southern Oscillation and the North Atlantic Oscillation. The causal relations of these results are...
The concept of nature as capital is gaining visibility in policies and practices in both the public and private sectors. This change is due to an improved ability to assess and value ecosystem services, as well as to a growing recognition of the potential of an ecosystem services approach to...
Influenza A incidence peaks during winter in temperate regions. The basis for this pronounced seasonality is not understood, nor is it well documented how influenza A transmission principally occurs. Previous studies indicate that relative humidity (RH) affects both influenza virus transmission (IVT) and influenza virus survival (IVS). Here, we reanalyze...
Marine bacteria from the SAR11 clade (class Alphaproteobacteria), specifically strains
HTCC1062 and HTCC7211, were characterized according to a polyphasic taxonomic approach.
Maximum cell densities and growth rates at various temperatures, salinities, and pH’s were
analyzed. Strains HTCC1062 and HTCC7211 were observed as having different growth
optimums. On the basis of...
Wind-driven coastal ocean upwelling supplies nutrients to the
euphotic zone near the coast. Nutrients fuel the growth of phytoplankton,
the base of a very productive coastal marine ecosystem
[Pauly D, Christensen V (1995) Nature 374:255–257]. Because
nutrient supply and phytoplankton biomass in shelf waters are
highly sensitive to variation in...
Identifying the ecological and evolutionary mechanisms that determine biological diversity is a central question in ecology. In microbial ecology, phylogenetic diversity is an increasingly common and relevant means of quantifying community diversity, particularly given the challenges in defining unambiguous species units from environmental sequence data. We explore patterns of phylogenetic...
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microbes. Proceedings of the
National Academy of Sciences, 112(27), 8356-8361.
doi:10.1073/pnas
Genome-enabled mycology is a rapidly expanding field that is characterized by the pervasive use of genome-scale data and associated computational tools in all aspects of fungal biology. Genome-enabled mycology is integrative and often requires teams of researchers with diverse skills in organismal mycology, bioinformatics and molecular biology. This issue of...
The dynamics of the Min-protein system help Escherichia coli regulate the process of cell division by identifying the center of the cell. While this system exhibits robust bipolar oscillations in wild-type cell shapes, recent experiments have shown that when the cells are mechanically deformed into wide, flattened out, irregular shapes,...
Litter decomposition is a keystone ecosystem process impacting nutrient cycling and productivity, soil properties, and the terrestrial carbon (C) balance, but the factors regulating decomposition rate are still poorly understood. Traditional models assume that the rate is controlled by litter quality, relying on parameters such as lignin content as predictors....
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.
doi:10.1073/pnas.1508945112
10.1073/pnas.1508945112
National Academy of Sciences
Version of Record
More than US$21 billion is spent annually on biodiversity conservation. Despite their importance for preventing or slowing extinctions and preserving biodiversity, conservation interventions are rarely assessed systematically for their global impact. Islands house a disproportionately higher amount of biodiversity compared with mainlands, much of which is highly threatened with extinction....
We show that the vegetation canopy of the Amazon rainforest is
highly sensitive to changes in precipitation patterns and that
reduction in rainfall since 2000 has diminished vegetation greenness
across large parts of Amazonia. Large-scale directional
declines in vegetation greenness may indicate decreases in carbon
uptake and substantial changes in...
Knowledge of cloud and precipitation formation processes remains
incomplete, yet global precipitation is predominantly produced by
clouds containing the ice phase. Ice first forms in clouds warmer
than −36 °C on particles termed ice nuclei. We combine observations
from field studies over a 14-year period, from a variety of
locations...
Cells in three-dimensional (3D) environments exhibit very different biochemical and biophysical phenotypes compared to the behavior of cells in two-dimensional (2D) environments. As an important biomechanical measurement, 2D traction force microscopy can not be directly extended into 3D cases. In order to quantitatively characterize the contraction field, we have developed...
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Science 111: 2241–
2246 doi: 10.1073/pnas.1315606111
5. Paszek MJ, Zahir N, Johnson KR, Lakins JN
Ocean deoxygenation is predicted to increase in severity over the next few decades, posing a threat to marine life and fishing economies. Improved predictions of ocean deoxygenation depend on a better understanding of the biogeochemical mechanisms that underly this process. Within the realm of biogeochemical mechanisms, this project specifically investigated...
This dissertation uses manipulative experiments to explore amphibian-Bd infection dynamics. Although there has been almost two decades research since the discovery of Bd, many questions still remain regarding what conditions mediate chytridiomycosis virulence. My research shows how certain host and pathogen factors can influence disease virulence. Identifying how host and...
Oceanic iron (Fe) fertilization experiments have advanced the understanding of how Fe regulates biological productivity and air–sea carbon dioxide (CO₂) exchange. However, little is known about the production and consumption of halocarbons and other gases as a result of Fe addition. Besides metabolizing inorganic carbon, marine microorganisms produce and consume...
During the Deepwater Horizon oil well blowout in the Gulf of Mexico, the application of 7 million liters of chemical dispersants aimed to stimulate microbial crude oil degradation by increasing the bioavailability of oil compounds. However, the effects of dispersants on oil biodegradation rates are debated. In laboratory experiments, we...
Small RNAs, including microRNAs (miRNAs), small interfering RNAs
(siRNAs), and trans-acting siRNAs (tasiRNAs), control gene expression
and epigenetic regulation. Although the roles of miRNAs and
siRNAs have been extensively studied, their expression diversity
and evolution in closely related species and interspecific hybrids
are poorly understood. Here, we show comprehensive analyses...
The peptidyl nucleoside blasticidin S (BS) isolated from Streptomyces griseochromogenes was the first non-mercurial fungicide used on a large scale to prevent rice blast. In the biosynthesis of BS, leucylblasticidin S (LBS) was suggested as the penultimate metabolite with 20-fold less inhibitory activity than the final product BS. Incomplete conversion...
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Academy of Sciences of the United States of
America 100, 1541‐1546, doi:10.1073/pnas.0337542100 (2003
Iron (Fe) and copper (Cu) are essential cofactors for microbial metalloenzymes, but little is known about the metalloenyzme inventory of anaerobic marine microbial communities despite their importance to the nitrogen cycle. We compared dissolved O₂ , NO₃⁻, NO₂⁻, Fe and Cu concentrations with nucleic acid sequences encoding Fe and Cu-binding...
Summertime wind stress along the coast of the northwestern United States typically exhibits intraseasonal oscillations (ISOs) with periods from ≈15 to 40 days, as well as fluctuations on the 2- to 6-day “weather-band” and 1-day diurnal time scales. Coastal upwelling of cool, nutrient-rich water is driven by extended periods of...
The Younger Dryas cold interval represents a time when much of the Northern Hemisphere cooled from ≈12.9 to 11.5 kiloyears B.P. The cause of this event, which has long been viewed as the canonical example of abrupt climate change, was initially attributed to the routing of freshwater to the St....
A previous study showed that ammonia oxidation by the Thaumarchaeota Nitrosopumilus maritimus (group 1.1a) was resistant
to concentrations of the C₈ 1-alkyne, octyne, which completely inhibits activity by ammonia-oxidizing bacteria. In this study, the
inhibitory effects of octyne and other C₂ to C₁₀ 1-alkynes were evaluated on the nitrite production...
Well-functioning food webs are fundamental for sustaining rivers as ecosystems and maintaining associated aquatic and terrestrial communities. The current emphasis on restoring habitat structure-without explicitly considering food webs-has been less successful than hoped in terms of enhancing the status of targeted species and often overlooks important constraints on ecologically effective...
Despite progressive policies and continued advances in ocean management, numerous shifts associated with global changes have been observed in marine ecosystems in recent years, including warming, ocean acidification, and deoxygenation. As global change accelerates, science is needed to inform evidence-based management strategies for continued ecosystem services. Resilience management, in which...
The Amazon rainforest is a critical hotspot for bio-diversity, and plays an essential role in global carbon, water and energy fluxes and the earth's climate. Our ability to project the role of vegetation carbon feedbacks on future climate critically depends upon our understanding of this tropical ecosystem, its tolerance to...
Anthozoa-class red fluorescent proteins (RFPs) are frequently used as biological markers, with far-red (lambda(em) similar to 600-700 nm) emitting variants sought for whole-animal imaging because biological tissues are more permeable to light in this range. A barrier to the use of naturally occurring RFP variants as molecular markers is that...
Submersible exploration of the Samoan hotspot revealed a new, 300-m-tall, volcanic cone, named Nafanua, in the summit crater of Vailulu’u seamount. Nafanua grew from the 1,000-m-deep crater floor in <4 years and could reach the sea surface within decades. Vents fill Vailulu’u crater with a thick suspension of particulates and...
Transacting siRNA (tasiRNA) biogenesis in Arabidopsis is initiated
by microRNA (miRNA) –guided cleavage of primary transcripts. In
the case of TAS3 tasiRNA formation, ARGONAUTE7 (AGO7)–
miR390 complexes interact with primary transcripts at two sites,
resulting in recruitment of RNA-DEPENDENT RNA POLYMERASE6
for dsRNA biosynthesis. An extensive screen for Arabidopsis mutants...
Neurospora crassa has been for decades a principal model for filamentous
fungal genetics and physiology as well as for understanding
the mechanism of circadian clocks. Eukaryotic fungal and animal
clocks comprise transcription-translation-based feedback loops that
control rhythmic transcription of a substantial fraction of these transcriptomes,
yielding the changes in protein...
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potential. Proceedings
of the National Academy of Sciences, 111(48), 16995-17002.
doi:10.1073/pnas
The most diverse marine ecosystems, coral reefs, depend upon a functional symbiosis between a cnidarian animal host (the coral) and intracellular photosynthetic dinoflagellate algae. The molecular and cellular mechanisms underlying this endosymbiosis are not well understood, in part because of the difficulties of experimental work with corals. The small sea...
Our experiments aimed to investigate responses of the marine cyanobacteria Prochlorococcus and Synechococcus to toxic arsenic species, such as arsenate, and to understand cellular mechanisms that contribute to arsenic tolerance. We used two strains of Prochlorococcus, a high-light adapted MED4 and low-light adapted MIT9313, both axenic, for cultivation experiments. For...
Climate variability and change are considerably important for a wide range of human activities and natural ecosystems. Climate science has made major advances during the last two decades, yet climate information is neither routinely useful for nor used in planning. What is needed is a mechanism, a national climate service...
The cycloundecapeptide cyclosporin A (CsA) was first isolated from the insect-pathogenic fungus Tolypocladium inflatum for its antifungal activity and later developed as an immunosuppressant drug. However, the full biosynthetic mechanism of CsA remains unknown and has puzzled researchers for decades. In this study, the biosynthetic gene cluster is suggested to...
Previous studies of coral viruses have employed either microscopy or metagenomics, but few have attempted to comprehensively link the presence of a virus-like particle (VLP) to a genomic sequence. We conducted transmission electron microscopy imaging and virome analysis in tandem to characterize the most conspicuous viral types found within the...
Novel broad-spectrum antimicrobials are a critical component of a strategy for combating antibiotic-resistant pathogens. In this
study, we explored the activity of the broad-spectrum antiviral compound ST-669 for activity against different intracellular bacteria
and began a characterization of its mechanism of antimicrobial action. ST-669 inhibits the growth of three different...
These first measurements of specific surface area (SSA)
of bulk samples of subsurface marine basalts were undertaken
to determine the potential area available for microbial
colonization. SSA ranged from 0.3 to 52 m2/g of basalt
with the lowest value coming from pillow basalt and the
highest value from breccia. The...
Estrogen (E2) is essential for multiple physiological effects in females, ensuring maximum reproductive fitness and maintaining skeletal homeostasis. E2 has been shown to stimulate cancellous bone formation via activation of estrogen receptor alpha (ERα), an effect widely accepted to be mediated directly at bone. A recent landmark study by Herber...
The aim of this study was to evaluate the effects of intranasally administered oxytocin on the sociability of adult, neutered, male and female shelter cats, as measured by proximity-seeking behavior and meow vocalizations. Two local Humane Societies were sampled in this study. The shelter cats were randomly assigned to one...
Methane (CH₄) is a valuable fuel, constituting 70–95% of natural gas, and a potent
greenhouse gas. Release of CH₄ into the atmosphere contributes to climate change.
Biological CH₄ production or methanogenesis is mostly performed by methanogens, a
group of strictly anaerobic archaea. The direct substrates for methanogenesis are H₂
plus...
Prostate cancer is one of the most prevalent types of cancer in the U.S. and is among the leading causes of death in men of all races. One predictor of advanced prostate cancer and aggressive tumor behavior is the overexpression of the histone methyl transferase EZH2.
EZH2 functions in the...
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:10.1073/pnas.1933744100.
3. Cavalli G. EZH2 Goes Solo. Science. 2012;338(6113):1430–1431. doi:10.1126
Prostate cancer is one of the most prevalent types of cancer in the U.S. and is among the leading causes of death in men of all races. One predictor of advanced prostate cancer and aggressive tumor behavior is the overexpression of the histone methyl transferase EZH2.
EZH2 functions in the...
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epithelial cells. Proc. Natl. Acad. Sci. 2003;100(20):11606–11611. doi:10.1073/pnas.1933744100.
3. Cavalli G
Prostate cancer is one of the most prevalent types of cancer in the U.S. and is among the leading causes of death in men of all races. One predictor of advanced prostate cancer and aggressive tumor behavior is the overexpression of the histone methyl transferase EZH2.
EZH2 functions in the...
Full Text:
:10.1073/pnas.1933744100.
3. Cavalli G. EZH2 Goes Solo. Science. 2012;338(6113):1430–1431. doi:10.1126
Prostate cancer is one of the most prevalent types of cancer in the U.S. and is among the leading causes of death in men of all races. One predictor of advanced prostate cancer and aggressive tumor behavior is the overexpression of the histone methyl transferase EZH2.
EZH2 functions in the...
Full Text:
epithelial cells. Proc. Natl. Acad. Sci. 2003;100(20):11606–11611. doi:10.1073/pnas.1933744100.
3. Cavalli G
Many ecologists and environmental scientists witnessing the scale of current environmental change are becoming increasingly alarmed about how humanity is pushing the boundaries of the Earth’s systems beyond sustainable levels. The world urgently needs global society to redirect itself toward a more sustainable future: one that moves intergenerational equity and...
Microglia and reactive astrocytes accumulate in the spinal cord of rats expressing the Amyotrophic lateral sclerosis (ALS)-linked SOD1ᴳ⁹³ᴬ mutation. We previously reported that the rapid progression of paralysis in ALS rats is associated with the appearance of prolifer- ative astrocyte-like cells that surround motor neurons. These cells, designated as Aberrant...
Deciphering the evolution of global climate from the end of the Last Glacial Maximum approximately 19 ka to the early Holocene 11 ka presents an outstanding opportunity for understanding the transient response of Earth's climate system to external and internal forcings. During this interval of global warming, the decay of...
Seasonality and drought in Amazon rainforests have been controversially discussed in the literature, partially due to a limited ability of current remote sensing techniques to detect its impacts on tropical vegetation. We use a multi-angle remote sensing approach to determine changes in vegetation structure from differences in directional scattering (anisotropy)...
The global terrestrial carbon sink offsets one-third of the world’s fossil fuel emissions, but the strength of this sink is highly sensitive to large-scale extreme events. In 2012, the contiguous United States experienced exceptionally warm temperatures and the most severe drought since the Dust Bowl era of the 1930s, resulting...
Pseudomonas syringae are plant pathogenic bacteria that cause disease by rapidly multiplying within the aboveground tissues of host plants. Growth of P. syringae within plant host tissues requires the disarmament of host immune defenses that limit microbial growth. To combat host defenses, P. syringae deploys a type III secretion system...
Autoinduction (AI), the response to self-produced chemical signals,
is widespread in the bacterial world. This process controls
vastly different target functions, such as luminescence, nutrient
acquisition, and biofilm formation, in different ways and integrates
additional environmental and physiological cues. This diversity
raises questions about unifying principles that underlie all
AI...
In eukaryotes, ARGONAUTE proteins (AGOs) associate with microRNAs (miRNAs), short
interfering RNAs (siRNAs), and other classes of small RNAs to regulate target RNA or target
loci. Viral infection in plants induces a potent and highly specific antiviral RNA silencing
response characterized by the formation of virus-derived siRNAs. Arabidopsis thaliana has...
Twenty years ago, the creation of a new scientific program, the Partnership for Interdisciplinary Studies of Coastal Oceans (PISCO), funded by the Packard Foundation, provided the opportunity to integrate—from the outset—research, monitoring, and outreach to the public, policymakers, and managers. PISCO’s outreach efforts were initially focused primarily on sharing scientific...
Many bacteria possess cell density-dependent quorum-sensing (QS) systems that often regulate cooperative secretions involved
in host-microbe or microbe-microbe interactions. These secretions, or “public goods,” are frequently coregulated by stress and
starvation responses. Here we provide a physiological rationale for such regulatory complexity in the opportunistic pathogen
Pseudomonas aeruginosa. Using minimal-medium...
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aeruginosa. Proc. Natl. Acad. Sci.
U. S. A. 96:13904 –13909. http://dx.doi.org/10.1073/pnas.96.24.13904.
16
To stabilize cellular integrity in the face of environmental perturbations, most bacteria, including cyanobacteria, synthesize and
maintain a strong, flexible, three-dimensional peptidoglycan lattice. Anabaena sp. strain PCC 7120 is a filamentous cyanobacterium
capable of differentiating morphologically distinct nitrogen-fixing heterocyst cells in a periodic pattern. While heterocyst
development has been shown...
BACKGROUND: Triticum monococcum (2n) is a close ancestor of T. urartu, the A-genome progenitor of cultivated hexaploid
wheat, and is therefore a useful model for the study of components regulating photomorphogenesis in diploid wheat. In
order to develop genetic and genomic resources for such a study, we constructed genome-wide transcriptomes...
To detect and avoid illegal logging of valuable tree species, identification methods for the origin of timber are necessary. We used next-generation sequencing to identify chloroplast genome regions that differentiate the origin of white oaks from the three continents; Asia, Europe, and North America. By using the chloroplast genome of...
While there has been growing interest in the gut microbiome in recent years, it remains unclear whether closely related species and strains have similar or distinct functional roles and if organisms capable of both aerobic and anaerobic growth do so simultaneously. To investigate these questions, we implemented a high-throughput mass...
Epidemics of infectious diseases often occur in predictable limit cycles. Theory suggests these cycles can be disrupted by high amplitude seasonal fluctuations in transmission rates, resulting in deterministic chaos. However, persistent deterministic chaos has never been observed, in part because sufficiently large oscillations in transmission rates are uncommon. Where they...
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. National Acad Sciences;
2012; 109: 20425–20430. doi: 10.1073/pnas.1208772109 PMID: 23184969
10. Łuksza M
An increase in anthropogenic activities since the industrial revolution, primarily due to burning of fossil fuels and changes in land cover, has resulted in a steady increase in the global mean atmospheric CO2 concentrations. While there is unequivocal scientific evidence on global warming and its multidimensional impacts on natural and...
Measurements that link surface conditions and climate can provide critical information on important biospheric changes occurring in the Earth system. As the direct driving force of energy and water fluxes at the surface-atmosphere interface, land surface temperature (LST) provides information on physical processes of land-cover change and energy-balance changes that...
Members of Gram-positive Actinobacteria cause economically important diseases to plants. Within the Rhodococcus genus,
some members can cause growth deformities and persist as pathogens on a wide range of host plants. The current model
predicts that phytopathogenic isolates require a cluster of three loci present on a linear plasmid, with...
Ammonia oxidation is the first and rate-limiting step in nitrification and is dominated by two distinct groups of microorganisms in soil: ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB). AOA are often more abundant than AOB and dominate activity in acid soils. The mechanism of ammonia oxidation under acidic conditions has...
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Sci U S A
108:21206 –21211. http://dx.doi.org/10.1073/pnas.1109000108.
5. Booth MS, Stark JM
Recent warnings from scientists suggest there is limited time to enact policies to avert wide‐ranging ecological and social damage from climate change. In the United States, discussions about comprehensive national policies to avert climate change have begun, with “Green New Deal” proposals and climate plans put forth by members of...
Microbial communities in Arctic coastal lagoons drive biogeochemical cycles at the terrestrial-marine interface and help to determine the fate and form of resources like nitrogen (N) and carbon (C) as they are delivered to the Arctic Ocean. Though rising rates of primary production in the Arctic Ocean are well-characterized, the...
The oceans are one of humanity’s greatest resources, providing food, raw materials, livelihoods, and protection. More than 3 billion people around the world rely on marine life as a source of protein as well as their livelihood. Seafood is one of the highest traded commodities globally and many major cities...
Complex symbioses between animal or plant hosts and their associated microbiotas can involve thousands of species and millions of genes. Because of the number of interacting partners, it is often impractical to study all organisms or genes in these host-microbe symbioses individually. Yet new phylogenetic predictive methods can use the...
Cnidarians and their symbiotic dinoflagellates form a productive mutualism that shapes marine environments. In this symbiosis, dinoflagellate species from the family Symbiodiniacea reside within cnidarian host gastrodermal cells and provide the host with photosynthetically fixed carbon in exchange for host metabolites. This nutritional exchange allows both partners to thrive in...
The intensity and scale of wildfires has increased throughout the Pacific Northwest in recent decades, especially within the last decade, destroying vast amounts of valuable resources and assets. This trend is predicted to remain or even magnify due climate change, growing population, increased housing density. Furthermore, the associated stress of...
Copper and iron are essential micronutrients that are required by marine primary producers for a variety of metabolic processes. Over 99% of both copper and iron are bound within organic complexes in the marine environment, however the molecular identity of many of these complexes remains unknown. The speciation of these...
Viruses were defined as one of the two principal types of organisms
in the biosphere, namely, as capsid-encoding organisms in
contrast to ribosome-encoding organisms, i.e., all cellular life
forms. Structurally similar, apparently homologous capsids are
present in a huge variety of icosahedral viruses that infect bacteria,
archaea, and eukaryotes. These...
Successful host cell colonization by the Q fever pathogen, Coxiella burnetii, requires translocation of effector proteins into
the host cytosol by a Dot/Icm type 4B secretion system (T4BSS). In Legionella pneumophila, the two-component system (TCS)
PmrAB regulates the Dot/Icm T4BSS and several additional physiological processes associated with pathogenesis. Because PmrA...
I researched depictions of dragons in several works of modern literature to conceptualize what a dragon looks like and how they generally function in popular media. From there, I researched several key characteristics of dragons to see how they work with science’s current understanding. I looked into size and scaling,...
Plasmid transformation of chlamydiae has created new opportunities to investigate host–microbe interactions during chlamydial infections; however, there are still limitations. Plasmid transformation requires a replicon derived from the native Chlamydia plasmid, and these transformations are species-specific. We explored the utility of a broad host-range plasmid, pBBR1MCS-4, to transform chlamydiae, with...
Magnetic materials can be used in modern soft robotics as a method for external stimulus actuation and motion control. By combining aspects of biology and mechanics, devices are fabricated to create a structure capable of complex movement. Applications that these devices are subject to can be broken down into four...
Marine microbes exhibit highly varied, often non-spherical shapes that have functional significance for essential processes, including nutrient acquisition and sinking rates. There is a surprising absence of data, however, on how cell shape affects grazing, which is crucial for predicting the fate of oceanic carbon. We used synthetic spherical and...
Many populations consist of individuals that differ substantially in their diets. Quantification of the magnitude and temporal consistency of such intraspecific diet variation is needed to understand its importance, but the extent to which different approaches for doing so reflect instantaneous vs. time-aggregated measures of individual diets may bias inferences....
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diversification and
dietary specialization in sea otters. Proc. Natl. Acad. Sci. 105:560-565. doi:
10.1073/pnas
The ongoing retreat of glaciers globally is one of the clearest manifestations of recent global warming associated with rising greenhouse gas concentrations. By comparison, the importance of greenhouse gases in driving glacier retreat during the most recent deglaciation, the last major interval of global warming, is unclear due to uncertainties...
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the National
Academy of Sciences 111, 15296-15303, doi:10.1073/pnas.1411762111 (2014).
4 Fenton, C
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Perchlorate is a common aquatic contaminant that has long been known to affect thyroid function in vertebrates, including humans. More recently perchlorate has been shown...
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Academy of Sciences of the
United States of America. 2007; 104(43):16958–63. doi: 10.1073/pnas.0609932104