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1.
Proc Natl Acad Sci U S A ; 116(6): 2138-2145, 2019 02 05.
Article in English | MEDLINE | ID: mdl-30659144

ABSTRACT

Reactive nitrogen oxides (NOy; NOy = NO + NO2 + HONO) decrease air quality and impact radiative forcing, yet the factors responsible for their emission from nonpoint sources (i.e., soils) remain poorly understood. We investigated the factors that control the production of aerobic NOy in forest soils using molecular techniques, process-based assays, and inhibitor experiments. We subsequently used these data to identify hotspots for gas emissions across forests of the eastern United States. Here, we show that nitrogen oxide soil emissions are mediated by microbial community structure (e.g., ammonium oxidizer abundances), soil chemical characteristics (pH and C:N), and nitrogen (N) transformation rates (net nitrification). We find that, while nitrification rates are controlled primarily by chemoautotrophic ammonia-oxidizing archaea (AOA), the production of NOy is mediated in large part by chemoautotrophic ammonia-oxidizing bacteria (AOB). Variation in nitrification rates and nitrogen oxide emissions tracked variation in forest communities, as stands dominated by arbuscular mycorrhizal (AM) trees had greater N transformation rates and NOy fluxes than stands dominated by ectomycorrhizal (ECM) trees. Given mapped distributions of AM and ECM trees from 78,000 forest inventory plots, we estimate that broadleaf forests of the Midwest and the eastern United States as well as the Mississippi River corridor may be considered hotspots of biogenic NOy emissions. Together, our results greatly improve our understanding of NOy fluxes from forests, which should lead to improved predictions about the atmospheric consequences of tree species shifts owing to land management and climate change.


Subject(s)
Ecosystem , Environmental Microbiology , Forests , Microbiota , Reactive Nitrogen Species , Soil , Geography , Metabolic Networks and Pathways , Nitric Oxide/metabolism , Nitrification , Oxidation-Reduction
2.
Curr Opin Anaesthesiol ; 35(4): 493-501, 2022 Aug 01.
Article in English | MEDLINE | ID: mdl-35787534

ABSTRACT

PURPOSE OF REVIEW: Nonoperating room anesthesia (NORA) procedures have expanded in number, variety, and complexity. NORA involves all age groups, including frail older adults and patients often considered too sick to tolerate traditional surgical interventions. Postoperative pulmonary complications are a significant source of adverse events in the perioperative setting. We present a review focused on preventing pulmonary complications in the interventional NORA setting. RECENT FINDINGS: NORA locations should function as independent, autonomous ambulatory units. We discuss a strategic plan involving a thorough preoperative evaluation of patients, including recognizing high-risk patients and their anesthetic management. Finally, we offer guidance on the challenges of conducting sedation and anesthesia in patients with coronavirus disease 2019 (COVID-19) or a history of COVID-19. SUMMARY: The demands on the interventional NORA anesthesia team are increasing. Strategic planning, checklists, consistent staffing assignments, and scheduled safety drills are valuable tools to improve patient safety. In addition, through quality improvement initiatives and reporting, NORA anesthetists can achieve reductions in periprocedural pulmonary complications.


Subject(s)
Anesthesia , Anesthesiology , Anesthetics , COVID-19 , Aged , Anesthesia/methods , Anesthetics/adverse effects , Humans , Patient Safety
3.
Glob Chang Biol ; 2020 Dec 15.
Article in English | MEDLINE | ID: mdl-33319480

ABSTRACT

Volatile nitrogen oxides (N2 O, NO, NO2 , HONO, …) can negatively impact climate, air quality, and human health. Using soils collected from temperate forests across the eastern United States, we show microbial communities involved in nitrogen (N) cycling are structured, in large part, by the composition of overstory trees, leading to predictable N-cycling syndromes, with consequences for emissions of volatile nitrogen oxides to air. Trees associating with arbuscular mycorrhizal (AM) fungi promote soil microbial communities with higher N-cycle potential and activity, relative to microbial communities in soils dominated by trees associating with ectomycorrhizal (ECM) fungi. Metagenomic analysis and gene expression studies reveal a 5 and 3.5 times greater estimated N-cycle gene and transcript copy numbers, respectively, in AM relative to ECM soil. Furthermore, we observe a 60% linear decrease in volatile reactive nitrogen gas flux (NOy  ≡ NO, NO2 , HONO) as ECM tree abundance increases. Compared to oxic conditions, gas flux potential of N2 O and NO increase significantly under anoxic conditions for AM soil (30- and 120-fold increase), but not ECM soil-likely owing to small concentrations of available substrate ( NO 3 - ) in ECM soil. Linear mixed effects modeling shows that ECM tree abundance, microbial process rates, and geographic location are primarily responsible for variation in peak potential NOy flux. Given that nearly all tree species associate with either AM or ECM fungi, our results indicate that the consequences of tree species shifts associated with global change may have predictable consequences for soil N cycling.

4.
Pain Med ; 21(10): 2336-2347, 2020 10 01.
Article in English | MEDLINE | ID: mdl-32895703

ABSTRACT

OBJECTIVE: Recent studies suggest that sensory phenotyping may provide critical information for the diagnosis and management of patients with chronic neuropathic pain (NP). However, many formal quantitative sensory testing (QST) paradigms require expensive equipment, a dedicated location, and substantial time commitments on the part of patient and examiner, highlighting the need for a convenient and portable "bedside" QST battery. We developed and tested a bedside QST battery in a sample of patients with chronic NP. METHODS: Participants (N = 51) attended two in-person visits over approximately two weeks, during which they underwent QST using both laboratory-based equipment and simple, easily accessible bedside tools. Participants also completed questionnaires about their daily pain and NP symptoms. RESULTS: Test-retest reliability estimates were highly statistically significant and did not differ between bedside (mean r = 0.60) and laboratory-based (mean r = 0.72) QST. Bedside QST variables and corresponding laboratory-based QST variables were highly correlated, suggesting adequate criterion validity for the bedside tests. CONCLUSIONS: Results from the present study may have important implications for the sensory phenotyping and subsequent management of patients with chronic NP. Implementation of a protocol that uses inexpensive, portable, and convenient tools may allow for the application of QST in variety of clinical settings and advance NP research.


Subject(s)
Neuralgia , Pain Threshold , Boston , Humans , Neuralgia/diagnosis , Pain Measurement , Reproducibility of Results
5.
Mol Ecol ; 28(17): 3994-4011, 2019 09.
Article in English | MEDLINE | ID: mdl-31344288

ABSTRACT

Intraspecific niche divergence is an important driver of species range, population abundance and impacts on ecosystem functions. Genetic changes are the primary focus when studying intraspecific divergence; however, the role of ecological interactions, particularly host-microbiome symbioses, is receiving increased attention. The relative importance of these evolutionary and ecological mechanisms has seen only limited evaluation. To address this question, we used Microcystis aeruginosa, the globally distributed cyanobacterium that dominates freshwater harmful algal blooms. These blooms have been increasing in occurrence and intensity worldwide, causing major economic and ecological damages. We evaluated 46 isolates of M. aeruginosa and their microbiomes, collected from 14 lakes in Michigan, USA, that vary over 20-fold in phosphorus levels, the primary limiting nutrient in freshwater systems. Genomes of M. aeruginosa diverged along this phosphorus gradient in genomic architecture and protein functions. Fitness in low-phosphorus lakes corresponded with additional shifts within M. aeruginosa including genome-wide reductions in nitrogen use, an expansion of phosphorus assimilation genes and an alternative life history strategy of nonclonal colony formation. In addition to host shifts, despite culturing in common-garden conditions, host-microbiomes diverged along the gradient in taxonomy, but converged in function with evidence of metabolic interdependence between the host and its microbiome. Divergence corresponded with a physiological trade-off between fitness in low-phosphorus environments and growth rate in phosphorus-rich conditions. Co-occurrence of genotypes adapted to different nutrient environments in phosphorus-rich lakes may have critical implications for understanding how M. aeruginosa blooms persist after initial nutrient depletion. Ultimately, we demonstrate that the intertwined effects of genome evolution, host life history strategy and ecological interactions between a host and its microbiome correspond with an intraspecific niche shift with important implications for whole ecosystem function.


Subject(s)
Evolution, Molecular , Genome , Harmful Algal Bloom , Microbiota/genetics , Microcystis/genetics , Genetic Variation , Microcystis/growth & development , Microcystis/isolation & purification , Microcystis/physiology , Phylogeny
6.
Opt Express ; 27(3): 2962-2974, 2019 Feb 04.
Article in English | MEDLINE | ID: mdl-30732325

ABSTRACT

We propose using piecewise parabolic phase modulation of the seed laser for suppressing stimulated Brillouin scattering (SBS) in a fiber amplifier. Simulations are run with a 9 m passive fiber. Compared with random phase modulation and 0-π pseudo-random phase modulation, the piecewise parabolic phase waveform yields a higher SBS threshold per unit bandwidth. If the bandwidth is defined as the range of frequencies containing 85% of the total power, the threshold for parabolic phase modulation is 1.4 times higher than the threshold for the five- or seven-bit pseudo-random modulation format. If the bandwidth is defined more tightly, e.g., the range of frequencies containing 95% of the total power, the threshold for parabolic phase modulation is three times higher. For both cases, achieving a bandwidth of 1.5 GHz requires a maximum phase shift of ~30 radians. All of the waveforms are compared on the basis of the bandwidth required of the phase moduator. The coherence functions are calculated in order to compare their suitability for coherent combining.

8.
Environ Manage ; 64(3): 258-271, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31359094

ABSTRACT

The transport and processing of nutrients and organic matter in streams are important functions that influence the condition of watersheds and downstream ecosystems. In this study, we investigated the effects of streambed sediment removal on biogeochemical cycling in Fawn River, a gravel-bottomed river in Indiana, U.S.A. We measured stream metabolism as well as nitrogen (N) and phosphorus (P) retention in both restored and unrestored reaches of Fawn River to examine how sediment removal affected multiple biogeochemical functions at the reach scale. We also assessed the properties of restored and unrestored streambed sediments to elucidate potential mechanisms driving observed reach-scale differences. We found that sediment removal led to lower rates of primary productivity and ecosystem respiration in the restored reach, likely due to macrophyte removal and potentially due to changes to sediment organic matter quality. We found minimal differences in N and P retention, suggesting that these processes are controlled at larger spatial or temporal scales than were examined in this study. Denitrification enzyme activity was lower in sediments from the restored reach compared to the unrestored reach, suggesting that restoration may have decreased N removal. Our results indicate that most near-term changes in biogeochemical function following restoration could be attributed to macrophyte removal, although effects from sediment removal may emerge over longer timescales.


Subject(s)
Ecosystem , Rivers , Geologic Sediments , Indiana , Nitrogen , Phosphorus
9.
Curr Opin Anaesthesiol ; 32(4): 480-487, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31219872

ABSTRACT

PURPOSE OF REVIEW: The first computer-assisted personalized sedation (CAPS) device was developed to address the growing demand for routine endoscopy procedures in the United States in the early 2000s. This review will describe the environment that gave rise to CAPS and summarize the design of that first device. It will then discuss the market forces that led to the fall of CAPS, with sales of the device ending 2 years after commercialization. RECENT FINDINGS: CAPS was initially conceived as a means to enable proceduralists to administer conscious sedation with propofol safely. In the nearly 20 years since its conception, the expectations of patients and proceduralists for endoscopy sedation, have evolved from conscious sedation to deep. Due to the increased risk inherent in deep sedation, future CAPS devices should be tools for anesthesiologists, not proceduralists. SUMMARY: Over $2 billion are spent annually for anesthesia services in routine endoscopic procedures for low-risk patients; a spending rate that is not sustainable. CAPS, in an 'anesthesia oversight' model similar to medical supervision, has a future as a cost-efficient means for anesthesia services to provide sedation in endoscopy and other nonoperating room venues. Anesthesiologists should work with medical device companies and payers to develop a CAPS 'anesthesia oversight' model.


Subject(s)
Conscious Sedation/instrumentation , Deep Sedation/instrumentation , Drug Therapy, Computer-Assisted/instrumentation , Hypnotics and Sedatives/administration & dosage , Conscious Sedation/economics , Conscious Sedation/trends , Cost-Benefit Analysis , Deep Sedation/economics , Deep Sedation/trends , Drug Therapy, Computer-Assisted/economics , Drug Therapy, Computer-Assisted/trends , Endoscopy/adverse effects , Humans , Pain, Procedural/etiology , Pain, Procedural/prevention & control , United States
10.
Scand J Med Sci Sports ; 28(12): 2505-2514, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30203865

ABSTRACT

OBJECTIVE: To determine if serum S100B increases similarly as a result of playing American football compared to exercise alone. METHODS: Serum S100B was measured in division III collegiate football players before and after every home game during a single football season. Serum S100B was also measured before and after subjects walked on a treadmill for 30 minutes at a leisurely pace, ran on a treadmill while wearing and not wearing a football helmet at 6 mph for 8 minutes, and performed low-, moderate-, or high-intensity resistance exercise. RESULTS: Serum S100B increased significantly (P < 0.05) when subjects played in a football game, ran on a treadmill, or performed moderate-intensity resistance exercise. Pre-game serum S100B did not accumulate throughout the football season in any of the players (P > 0.05). The increase in serum S100B during football games was moderately and significantly correlated with both the number of hits (R2  = 0.407) and the number of plays (R2  = 0.484) that each player experienced (P < 0.001). Post-game serum S100B was greater in football players who played more than 50 plays compared to those players who played <50 plays, subjects who exercised on a treadmill, or subjects performing resistance exercise (P < 0.05). CONCLUSION: It is unclear if the higher S100B concentration in football players playing at least 50 plays was caused by exercise or hits. Therefore, if serum S100B is to be used as a biomarker of impacts, and possible brain injury in sport, exercise time and intensity should be taken into account as confounding variables.


Subject(s)
Football/physiology , Running/physiology , S100 Calcium Binding Protein beta Subunit/blood , Weight Lifting/physiology , Humans , Male , Young Adult
11.
Regul Toxicol Pharmacol ; 97: 24-32, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29885342

ABSTRACT

Medical device biocompatibility testing is used to evaluate the risk of adverse effects on tissues from exposure to leachates/extracts. A battery of tests is typically recommended in accordance with regulatory standards to determine if the device is biocompatible. In vitro cytotoxicity, a key element of the standards, is a required endpoint for all types of medical devices. Each validated cytotoxicity method has different methodology and acceptance criteria that could influence the selection of a specific test. In addition, some guidances are more specific than others as to the recommended test methods. For example, the International Organization for Standardization (ISO1) cites preference for quantitative methods (e.g., tetrazolium (MTT/XTT), neutral red (NR), or colony formation assays (CFA)) over qualitative methods (e.g., elution, agar overlay/diffusion, or direct), while a recent ISO standard for contact lens/lens care solutions specifically requires a qualitative direct test. Qualitative methods are described in United States Pharmacopeia (USP) while quantitative CFAs are listed in Japan guidance. The aim of this review is to compare the methodologies such as test article preparation, test conditions, and criteria for six cytotoxicity methods recommended in regulatory standards in order to inform decisions on which method(s) to select during the medical device safety evaluation.


Subject(s)
Biocompatible Materials/pharmacology , Equipment Safety , Materials Testing , Animals , Cell Survival/drug effects , Humans
12.
Proc Natl Acad Sci U S A ; 112(42): 13045-50, 2015 Oct 20.
Article in English | MEDLINE | ID: mdl-26438866

ABSTRACT

Despite significant advances in the treatment of Hodgkin's lymphoma (HL), a significant proportion of patients will not respond or will subsequently relapse. We identified CD25, the IL-2 receptor alpha subunit, as a favorable target for systemic radioimmunotherapy of HL. The scientific basis for the clinical trial was that, although most normal cells with exception of Treg cells do not express CD25, it is expressed by a minority of Reed-Sternberg cells and by most polyclonal T cells rosetting around Reed-Sternberg cells. Forty-six patients with refractory and relapsed HL were evaluated with up to seven i.v. infusions of the radiolabeled anti-CD25 antibody (90)Y-daclizumab. (90)Y provides strong ß emissions that kill tumor cells at a distance by a crossfire effect. In 46 evaluable HL patients treated with (90)Y-daclizumab there were 14 complete responses and nine partial responses; 14 patients had stable disease, and nine progressed. Responses were observed both in patients whose Reed-Sternberg cells expressed CD25 and in those whose neoplastic cells were CD25(-) provided that associated rosetting T cells expressed CD25. As assessed using phosphorylated H2AX (γ-H2AX) as a bioindicator of the effects of radiation exposure, predominantly nonmalignant cells in the tumor microenvironment manifested DNA damage, as reflected by increased expression of γ-H2AX. Toxicities were transient bone-marrow suppression and myelodysplastic syndrome in six patients who had not been evaluated with bone-marrow karyotype analyses before therapy. In conclusion, repeated (90)Y-daclizumab infusions directed predominantly toward nonmalignant T cells rosetting around Reed-Sternberg cells provided meaningful therapy for select HL patients.


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Hodgkin Disease/drug therapy , Immunoglobulin G/therapeutic use , Interleukin-2 Receptor alpha Subunit/immunology , Yttrium Radioisotopes/chemistry , Adult , Aged , Antibodies, Monoclonal, Humanized/chemistry , Antibodies, Monoclonal, Humanized/immunology , Daclizumab , Female , Hodgkin Disease/immunology , Humans , Immunoglobulin G/chemistry , Immunoglobulin G/immunology , Male , Middle Aged , Phosphorylation , Recurrence , Young Adult
13.
Clim Res ; 76(1): 17-39, 2018.
Article in English | MEDLINE | ID: mdl-33154611

ABSTRACT

This study presents results of the Agricultural Model Intercomparison and Improvement Project (AgMIP) Coordinated Global and Regional Assessments (CGRA) of +1.5° and +2.0°C global warming above pre-industrial conditions. This first CGRA application provides multi-discipline, multi-scale, and multi-model perspectives to elucidate major challenges for the agricultural sector caused by direct biophysical impacts of climate changes as well as ramifications of associated mitigation strategies. Agriculture in both target climate stabilizations is characterized by differential impacts across regions and farming systems, with tropical maize Zea mays experiencing the largest losses, while soy Glycine max mostly benefits. The result is upward pressure on prices and area expansion for maize and wheat Triticum aestivum, while soy prices and area decline (results for rice Oryza sativa are mixed). An example global mitigation strategy encouraging bioenergy expansion is more disruptive to land use and crop prices than the climate change impacts alone, even in the +2.0°C scenario which has a larger climate signal and lower mitigation requirement than the +1.5°C scenario. Coordinated assessments reveal that direct biophysical and economic impacts can be substantially larger for regional farming systems than global production changes. Regional farmers can buffer negative effects or take advantage of new opportunities via mitigation incentives and farm management technologies. Primary uncertainties in the CGRA framework include the extent of CO2 benefits for diverse agricultural systems in crop models, as simulations without CO2 benefits show widespread production losses that raise prices and expand agricultural area.

14.
Curr Opin Anaesthesiol ; 31(4): 463-468, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29870424

ABSTRACT

PURPOSE OF REVIEW: In an era where healthcare costs are being heavily scrutinized, every expenditure is reviewed for medical necessity. Multiple national gastroenterology societies have issued statements regarding whether an anesthesiologist is necessary for routine colonoscopies in American Society of Anesthesiologist (ASA) 1 and 2 patients. RECENT FINDINGS: A large percentage of patients are undergoing screening colonoscopy without any sedation at all, which would not require an independent practitioner to administer medications. Advances in technique and technology are making colonoscopies less stimulating. Advantages to administering sedation, including propofol, have been seen even when not administered under the direction of an anesthesiologist and complications seem to be rare. The additional cost of having monitored anesthesia care appears to be a driving factor in whether a patient receives it or not. SUMMARY: A large multiinstitutional randomized control trial would be necessary to rule out potential confounders and to determine whether there is a safety benefit or detriment to having anesthesiologist-directed care in the setting of routine colonoscopies in ASA 1 and 2 patients. Further discussion would be necessary regarding what the monetary value of that effect is if a small difference were to be detected.


Subject(s)
Anesthesia/statistics & numerical data , Anesthesiologists/statistics & numerical data , Colonoscopy/adverse effects , Early Detection of Cancer/adverse effects , Mass Screening/adverse effects , Anesthesia/economics , Anesthesia/methods , Colonoscopy/economics , Colonoscopy/methods , Colonoscopy/standards , Colorectal Neoplasms/diagnosis , Early Detection of Cancer/economics , Early Detection of Cancer/methods , Gastroenterology/economics , Gastroenterology/methods , Gastroenterology/standards , Health Expenditures , Humans , Insurance, Health, Reimbursement/standards , Mass Screening/economics , Mass Screening/methods , Mass Screening/organization & administration , Patient Safety , Patient Satisfaction , Practice Guidelines as Topic , United States
15.
Ecol Appl ; 27(5): 1657-1665, 2017 07.
Article in English | MEDLINE | ID: mdl-28401624

ABSTRACT

Climate change is driving large changes in the spatial and temporal distributions of species, with significant consequences for individual populations. Community- and ecosystem-level implications of altered species distributions may be complex and challenging to anticipate due to the cascading effects of disrupted interactions among species, which may exhibit threshold responses to extreme climatic events. Toxic, bloom-forming cyanobacteria like Microcystis are expected to increase worldwide with climate change, due in part to their high temperature optima for growth. In addition, invasive zebra mussels (Dreissena polymorpha) have caused an increase in Microcystis aeruginosa, a species typically associated with eutrophication, in low-nutrient lakes. We conducted a 13-yr study of a M. aeruginosa population in a low-nutrient lake invaded by zebra mussels. In 10 of the 13 years, there was a significant positive relationship between M. aeruginosa biomass and accumulated degree days, which are projected to increase with climate change. In contrast, Microcystis biomass was up to an order of magnitude lower than predicted by the above relationship during the other three years, including the warmest in the data set, following repeated heat-induced mass mortality of D. polymorpha. Thus, the positive relationship between Microcystis biomass and temperature was negated when its facilitating species was suppressed during a series of exceptionally warm summers. Predicting the net response of a species to climate change may therefore require, at minimum, quantification of responses of both the focal species and species that strongly interact with it over sufficiently long time periods to encompass the full range of climatic variability. Our results could not have been predicted from existing data on the short-term responses of these two interacting species to increased temperature.


Subject(s)
Climate Change , Dreissena/physiology , Hot Temperature , Lakes , Microcystis/physiology , Animals , Eutrophication , Introduced Species , Michigan
16.
Arch Sex Behav ; 46(5): 1503-1515, 2017 Jul.
Article in English | MEDLINE | ID: mdl-27571743

ABSTRACT

In recent years, issues surrounding transgender have garnered media and legal attention, contributing to rapidly shifting views on gender in the U.S. Yet, there is a paucity of data-driven studies on the public's views of transgender identity. This study reports the development and validation of the Transgender Attitudes and Beliefs Scale (TABS). After constructing an initial 96-item pool from consulting experts and existing scales, Phase 1 of the study was launched, involving an exploratory factor analysis of 48 items. The initial factor analysis with 295 participants revealed three factors across 33 items-16 items on interpersonal comfort, 11 on sex/gender beliefs, and 6 on human value. The internal consistency of each factor was high-α = .97 for Factor 1, α = .95 for Factor 2, and α = .94 for Factor 3. A confirmatory factor analysis was conducted in the second phase with an independent sample consisting of 238 participants. The Attitudes Toward Transgender Individual Scale and the Genderism and Transphobia Scale were also included to test for convergent validity, and the Rosenberg Self-Esteem Scale and the short form of the Marlowe-Crowne Social Desirability Scale were utilized to test discriminant validity. Both of the data collection phases employed MTurk, a form of online sampling with increased diversity compared to college student samples and more generalizability to the general U.S. POPULATION: TABS represents an addition to the literature in its ability to capture a more nuanced conceptualization of transgender attitude not found in previous scales.


Subject(s)
Attitude , Gender Identity , Sexual Behavior/psychology , Transgender Persons/psychology , Adolescent , Adult , Aged , Factor Analysis, Statistical , Female , Humans , Male , Middle Aged , Religion , Reproducibility of Results , Surveys and Questionnaires
17.
Appl Opt ; 56(3): B116-B122, 2017 Jan 20.
Article in English | MEDLINE | ID: mdl-28157874

ABSTRACT

In a high power fiber amplifier, a frequency-chirped seed interrupts the coherent interaction between the laser and Stokes waves, raising the threshold for stimulated Brillouin scattering (SBS). Moving the external mirror of a vertical cavity surface-emitting diode laser 0.2 µm in 10 µs can yield a frequency chirp of 5×1017 Hz/s at a nearly constant output power. Opto-electronic feedback loops can linearize the chirp, and stabilize the output power. The linear variation of phase with time allows multiple amplifiers to be coherently combined using a frequency shifter to compensate for static and dynamic path length differences. The seed bandwidth, as seen by the counter-propagating SBS, also increases linearly with fiber length, resulting in a nearly-length-independent SBS threshold. Experimental results at the 1.6 kW level with a 19 m delivery fiber are presented. A numerical simulation is also presented.

18.
Environ Microbiol ; 18(4): 1212-26, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26631909

ABSTRACT

Despite their homogeneous appearance, aquatic systems harbour heterogeneous habitats resulting from nutrient gradients, suspended particulate matter and stratification. Recent reports suggest phylogenetically conserved habitat preferences among bacterioplankton, particularly for particle-associated (PA) and free-living (FL) habitats. Here, we show that independent of lake nutrient level and layer, PA and FL abundance-weighted bacterial community composition (BCC) differed and that inter-lake BCC varied more for PA than for FL fractions. In low-nutrient lakes, BCC differences between PA and FL fractions were larger than those between lake layers. The reverse was true for high-nutrient lakes. Nutrient level affected BCC more in hypolimnia than in epilimnia, likely due to hypolimnetic hypoxia in high-nutrient lakes. In line with previous reports, we observed within-phylum operational taxonomic unit (OTU) habitat preference conservation, although not for all phyla, including the phylum with the highest average relative abundance across all habitats (Bacteroidetes). Consistent phylum-level habitat preferences may indicate that the functional traits that underpin ecological adaptation of freshwater bacteria to lake habitats can be phylogenetically conserved, although the levels of conservation are phylum dependent. Resolving taxa preferences for freshwater habitats sets the stage for identification of traits that underpin habitat specialization and associated functional traits that influence differences in biogeochemical cycling across freshwater lake habitats.


Subject(s)
Aquatic Organisms/genetics , Bacteria/genetics , Lakes/microbiology , Plankton/microbiology , Bacteria/classification , Ecosystem , Phylogeny , RNA, Ribosomal, 16S/genetics , Water Microbiology
19.
Water Environ Res ; 88(7): 602-10, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27329056

ABSTRACT

In North Carolina (NC), biosolids land application rates governed by crop nitrogen (N) requirements typically surpass crop phosphorus (P) needs, increasing surface water pollution potential. The NC Department of Environmental Quality (NCDEQ) is considering P-based biosolids application guidelines for some nutrient-impaired watersheds using the P Loss Assessment Tool (PLAT), but important biosolids information is lacking: total P (TP), water-extractable P (WEP), and percent water-extractable P (PWEP). In each of three seasons, we sampled 28 biosolids from 26 participating water resource recovery facilities (WRRFs) and analyzed for TP, WEP, and percent dry matter (DM), from which PWEP and nonsoluble P were calculated. Based on descriptive statistics and an online survey of treatment processes, biosolids were divided into Class A-alkaline, Class A-heat, Class B-slurry, and Class B-cake. The average TP in Class A alkaline stabilized biosolids was more than five times less than the average of the other biosolids, 5.0 vs. 26.6 g/kg, respectively. Averaged over biosolids, WEP and PWEP were 1.4 g/kg and 5.0%, respectively. Stabilization processes appeared to reduce WEP substantially, so biosolids potential soluble-P loss is low. Our data will allow PLAT to be used for biosolids P-loss risk assessments.


Subject(s)
Phosphorus/analysis , Waste Disposal, Fluid , Wastewater/analysis , Water Pollutants, Chemical/analysis , Solubility
20.
Ann Surg Oncol ; 22(3): 866-73, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25326397

ABSTRACT

BACKGROUND: Locally advanced breast cancer (LABC) poses complex management issues due to failure of response to chemotherapy and progression to local complications such as skin erosion, superinfection, and lymphedema. Most cell line and animal models are not adequate to study LABC. METHODS: A patient-derived xenograft (IOWA-1T) from a patient with LABC was characterized for expression profile, short tandem repeat profile, oncogenic mutations, xenograft growth, and response to therapy. RESULTS: Short tandem repeat profile authenticated the cell line as derived from a human woman. The primary tumor and derived xenografts were weakly estrogen receptor alpha positive (<5%), progesterone receptor negative, and HER2 nonamplified. Expression array profile compared to MCF-7 and BT-549 cell lines indicate that IOWA-1T was more closely related to basal breast cancer. IOWA-1T harbors a homozygous R248Q mutation of the TP53 gene; in vitro invasion assay was comparable to BT-549 and greater than MCF-7. IOWA-1T xenografts developed palpable tumors in 9.6 ± 1.6 days, compared to 49 ± 13 days for parallel experiments with BT-20 cells (p < 0.002). Tumor xenografts became locally advanced, growing to >2 cm in 21.6 ± 2 days, characterized by skin erosion necessitating euthanasia. The SUMO inhibitor anacardic acid inhibited the outgrowth of IOWA-1T xenografts, while doxorubicin had no effect on tumorigenesis. CONCLUSIONS: IOWA-1T is a novel cell line with an expression pattern consistent with basal breast cancer. Xenografts recapitulated LABC and provide a novel model for testing therapeutic drugs that may be effective in cases resistant to conventional chemotherapy.


Subject(s)
Biomarkers, Tumor/genetics , Breast Neoplasms/pathology , Carcinoma, Ductal, Breast/pathology , Disease Models, Animal , Gene Expression Profiling , Animals , Biomarkers, Tumor/metabolism , Blotting, Western , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Carcinoma, Ductal, Breast/genetics , Carcinoma, Ductal, Breast/metabolism , Cell Proliferation , Female , Flow Cytometry , Fluorescent Antibody Technique , Humans , Mice , Mice, Nude , Oligonucleotide Array Sequence Analysis , RNA, Messenger/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
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