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1.
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
2.
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
4.
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
5.
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
6.
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
7.
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
8.
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
9.
Nutr Cancer ; 67(5): 730-40, 2015.
Article in English | MEDLINE | ID: mdl-25880972

ABSTRACT

Grapes are one of the most consumed fruits in the world and are rich in polyphenols. Grape seed proanthocyanidins (GSP) have demonstrated chemopreventive and/or chemotherapeutic effects in various cancer cell cultures and animal models. The clinical efficacy of chemotherapy is often limited by its adverse effects. Several studies show that reactive oxygen species mediate the cardiotoxicity and neurotoxicity induced by various cancer chemotherapeutic agents. This implies that concomitant administration of antioxidants may prevent these adverse effects. The review was carried out in accordance with the PRISMA guidelines. An electronic search strategy in Medline and Embase databases was conducted. Of the 41 studies reviewed, 27 studied GSP while the remainder (14) studied grape seed or skin extracts (GSE). All the studies were published in English, except 2 in Chinese. A significant percentage (34%) of the studies we reviewed assessed the effect of GSE or GSP on cardiotoxicity induced by chemotherapy. Doxorubicin was the most common chemotherapeutic drug studied followed by cisplatin. Research studies that assessed the effect of GSE or GSP on radiation treatment accounted for 22% of the articles reviewed. GSE/GSP ameliorates some of the cytotoxic effects on normal cells/tissues induced by chemo/radiotherapy.


Subject(s)
Drug-Related Side Effects and Adverse Reactions/drug therapy , Grape Seed Extract/therapeutic use , Proanthocyanidins/therapeutic use , Radiation Injuries, Experimental/drug therapy , Animals , Drug Evaluation, Preclinical , Drug-Related Side Effects and Adverse Reactions/etiology , Mice , Radiation Injuries, Experimental/etiology , Rats , Rats, Sprague-Dawley , Rats, Wistar
11.
mBio ; 14(5): e0141523, 2023 Oct 31.
Article in English | MEDLINE | ID: mdl-37646528

ABSTRACT

IMPORTANCE: Understanding how natural selection has historically shaped the traits of microbial populations comprising host microbiomes would help predict how the functions of these microbes may continue to evolve over space and time. Numerous host-associated microbes have been found to adapt to their host, sometimes becoming obligate symbionts, whereas free-living microbes are best known to adapt to their surrounding environment. Our study assessed the selective pressures of both the host environment and the surrounding external environment in shaping the functional potential of host-associated bacteria. Despite residing within the resource-rich microbiome of their hosts, we demonstrate that host-associated heterotrophic bacteria show evidence of trait selection that matches the nutrient availability of their broader surrounding environment. These findings illustrate the complex mix of selective pressures that likely shape the present-day function of bacteria found inhabiting host microbiomes. Our study lends insight into the shifts in function that may occur as environments fluctuate over time.


Subject(s)
Microbiota , Bacteria/genetics
12.
J Integr Complement Med ; 29(2): 80-98, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36149678

ABSTRACT

Objectives: Complementary and alternative medicine (CAM) has become increasingly popular among cancer patients and is often used concomitantly with standard cancer therapies. Nonetheless, disclosure of CAM utilization by cancer patients to physicians, along with the provision of information on CAM therapies by physicians, is poor. This review explores the literature to synthesize existing information on communication about CAM usage, reasons for nondisclosure, and the clinical implications thereof. Methods: A search of medical literature published between December 1, 2009, and October 1, 2021 (last searched on April 18, 2022), on communications between physicians and cancer patients about CAM treatments was conducted through MEDLINE and EMBASE. Results were screened for inclusion, dually reviewed, and assessed using the QualSyst quality appraisal instrument. Findings were categorized and synthesized for review. Results: A total of 30 articles were located (n = 8721 total participants), which discussed elements related to patient disclosure of CAM use (n = 16), provider experiences or perceptions related to communication about CAM (n = 3), patterns of this communication (n = 6), and recommendations for effectively discussing CAM with cancer patients (n = 5). Reports indicate that nondisclosure is common throughout the cancer care spectrum. Factors influencing nondisclosure range from patient beliefs and attitudes about their provider, demographic characteristics, disease progression, physician-patient relationship, physician noninquiry, and type of CAM used; ultimately creating a gap in care that may have serious medical implications. Discussion: Many of the studies identified are small and confined to a single-center, hospital-network, or geographic setting, thereby limiting the applicability of findings and recommendations. Nonetheless, improving patient-physician communication is essential in delivering evidence-informed, patient-centered care and crucial for achieving patient satisfaction and positive health outcomes. The lack of adequate CAM dialogue about CAM use increases the risk of adverse interactions with conventional cancer treatments and results in missed opportunities for providers and patients to engage in vital information exchange. Future research and education are necessary to further identify barriers surrounding patient-provider communication about CAM treatments.


Subject(s)
Complementary Therapies , Neoplasms , Physicians , Humans , Communication , Neoplasms/therapy , Physician-Patient Relations
13.
Am J Infect Control ; 51(2): 194-198, 2023 Feb.
Article in English | MEDLINE | ID: mdl-35659562

ABSTRACT

BACKGROUND: We analyzed the qualitative fit test results of the filtering facepiece respirators (FFRs) used at our institution to determine their performance and utility. METHODS: We retrospectively analyzed 12,582 qualitative fit testing results for several FFR models among 8,809 health care workers (HCWs). RESULTS: The overall failure rate for HCWs was 15.2%. Nearly one-third (2933/8809, 33.3%) had multiple FFRs fit tested. HCW sex was a statistically significant indicator of fit testing failure (χ2 = 29.9, df = 1, P < .001), with women having a 44% higher likelihood (OR, 1.4; 95% CI: 1.27-1.65) than men. There were statistically significant differences in the failure rate across FFRs (Fig 4, F[5, 12475] = 8.4, P < .001). Fluidshield 46867S had a significantly higher failure rate (49%) than the 3M 1860 (P = .012), 3M 1860S (P < .001), 3M 8210 (P < .001), and Safelife (P < .001) FFRs. CONCLUSIONS: There was a large degree of variation in fit testing results for the FFRs tested. Although we were unable to find an FFR that fit more than 95% of the HCWs successfully, we identified poorly functioning FFRs that can help our institution with decision-making and budgeting for acquisition and stocking appropriate FFRs.


Subject(s)
Occupational Exposure , Respiratory Protective Devices , Male , Humans , Female , N95 Respirators , Retrospective Studies , Ventilators, Mechanical
14.
Cureus ; 14(11): e31779, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36569698

ABSTRACT

Background It has been shown that the incidence of venous air embolism and venous carbon dioxide (CO2) embolism is high during endoscopic retrograde cholangiopancreatography (ERCP). We examined insufflating gas flow and maximum pressure produced by three types of commonly used endoscopes because we could not readily locate technical data for endoscope gas flow and maximum emitted pressure in the manufacturer's manuals. Methods We tested the Olympus GIF-Q180 used for esophagogastroduodenoscopy, the CF-Q180 used for colonoscopy, and the TJF-Q180 used for ERCP (Olympus America Inc., Center Valley, Pennsylvania). Under three different clinical gas insufflation scenarios, we measured in vitro maximum gas pressure transduced from a closed space created at the endoscope tip in a worst-case scenario analysis. Results We showed that it is readily possible to generate a pressure (>5-30 times normal central venous pressure) in the air space at the tip of all three endoscopes when insufflation is activated and the gas egress is limited. Conclusions These findings shed additional light on in vivo occurrences of gas embolism during gastrointestinal endoscopy. We postulate that in addition to using exclusively CO2 as the insufflating gas, the risk of gas embolism can be further diminished by regulating insufflating gas pressure at the tip of endoscopes.

15.
Transl Oncol ; 25: 101484, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35944413

ABSTRACT

INTRODUCTION: The Exceptional Responders Initiative (ERI) at the National Cancer Institute attempts to correlate unusually good outcomes in patients with cancer with genetic targets in tumors and the therapies the patients received. It is not known if other factors might contribute to exceptional responses or outcomes. We explored aspects of the medical history, lifestyle changes, complementary and alternative medicine (CAM) use and communication between health care practitioners and patients who experienced an exceptional response following cancer treatment. METHODS: All subjects whose case was submitted to the ERI were eligible to participate in the survey. A 121-question survey questionnaire was developed to assess aspects of the subject's past medical history, lifestyle (e.g., diet, exercise, spirituality) and use of CAM. RESULTS: Thirty subjects completed and returned the questionnaire from approximately 88 patients invited to participate (approximate response rate = 34%). Approximately 68% were female and 32% were male. Fifty percent of subjects changed their diet after their cancer diagnosis. Eighteen patients (60%) reported using a CAM therapy (not including oral vitamins/minerals or spiritual practices) during their Exceptional Response (ER). CONCLUSION: Multiple factors, including features of the tumor itself, the patient, or the environment, could affect tumor response or patient survival, either solely or in combination with the treatments received. Many patients use other medications, change their diet or physical activity or use CAM interventions after their cancer diagnosis. Investigators attempting to understand the exceptional response phenomenon should acquire rich data sets of their subjects that include information about these factors.

16.
Cancer Invest ; 29(10): 655-67, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22085269

ABSTRACT

The risk-benefit ratio for concurrent use of dietary antioxidants with chemotherapy or radiation therapy is a controversial topic. In this review, the medical literature on concurrent antioxidant use with chemotherapy or radiotherapy was assessed and further steps for generating evidence-based guidelines are suggested. The clinical cancer research community should cooperate and focus new studies on the use of a specific combination of antioxidant and chemotherapy or radiotherapy, and determine optimal doses for a specific cancer setting. Mechanistic studies on the interaction between antioxidants and conventional cancer therapy could lead to novel biomarkers for assessing dose adequacy.


Subject(s)
Antioxidants/administration & dosage , Evidence-Based Practice , Neoplasms/therapy , Practice Guidelines as Topic , Acetylcysteine/administration & dosage , Glutathione/administration & dosage , Humans , Vitamin E/administration & dosage
19.
Integr Cancer Ther ; 20: 15347354211066081, 2021.
Article in English | MEDLINE | ID: mdl-34923872

ABSTRACT

BACKGROUND: Complementary and alternative medicine (CAM) is often used by cancer patients and survivors in the US. Many people turn to the internet as their first source of information. Health information seeking through the internet can be useful for patients to gain a better understanding of specific CAM treatments to discuss with their healthcare team, but only if the information is comprehensive, high quality, and reliable. The aim of this article is to examine the content, writing/vetting processes, and visibility of cancer CAM online informational resources. METHODS: Online CAM resources were identified by Google and PubMed searches, literature reviews, and through sources listed on various websites. The websites were analyzed through a modified online health information evaluation tool, DISCERN (score range = 1-5). The website's features relevant to the quality assessment were described. RESULTS: Eleven CAM websites were chosen for analysis. The DISCERN analysis showed a range of quality scores from 3.6 to 4.9. Lower DISCERN scores were generally due to deficiencies in describing the writing, editing, and updating processes. A lack of transparency with authorship and references was commonly present. CONCLUSION: Cancer patients interested in CAM need unbiased, evidence-based, reliable, high-quality, easily accessible educational materials. Individuals should use the guidelines followed in this analysis (including DISCERN and Medline Plus) to find reliable sources. Website developers can use CAM Cancer (NAFKAM), Beyond Conventional Cancer Therapies, Memorial Sloan Kettering Cancer Center, breastcancer.org, Office of Dietary Supplements, National Center for Complementary and Integrative Health, and Cancer.gov as models for trustworthy content.


Subject(s)
Breast Neoplasms , Complementary Therapies , Internet , Female , Humans , Information Seeking Behavior , Survivors
20.
Water Res ; 202: 117434, 2021 Sep 01.
Article in English | MEDLINE | ID: mdl-34388474

ABSTRACT

Despite massive financial investment in mitigation, eutrophication remains a major water quality problem and management priority. Eutrophication science-well established for lakes-is not as well developed for rivers, and scientific understanding of how rivers respond to eutrophication management is far more limited. Long-term data are required to evaluate progress, but such datasets are relatively rare for rivers. We analyzed 23 years of water quality data for the Charles River, a major urban river system in the northeastern U.S.A., to examine nutrient and phytoplankton biomass (chl-a) responses to decades of phosphorus (P) management. Using the more novel and robust approach of quantile regression, we identified statistically and ecologically significant declines in both total phosphorus (TP) and chl-a over time, but only for middle percentiles. Statistically high concentrations of TP and chl-a persist-the segments of the data of greatest concern to managers and the public-and yet this critical result is concealed by statistical tests often employed in eutrophication studies that only evaluate mean changes. TP, temperature, precipitation, and river segment jointly explain the most chl-a variation observed at the decadal scale. Spatial variation is also considerable: despite a significant decline in TP, the impounded lower river exhibits no long-term trend in chl-a and continues to experience annual blooms of harmful cyanobacteria-a lagging response comparable to that of a recovering eutrophic lake. Despite long-term successes in reducing P, chl-a, and cyanobacteria in the Charles River system, we did not detect any significant, long-term change in the attainment of statutory compliance, illustrating the protracted and complex nature of the river's response. Our analysis demonstrates the need for high-frequency, long-term water quality data to evaluate the progress of eutrophication management in urban rivers, and the utility of quantile regression for detecting critical trends in the occurrence of statistically low-frequency but ecologically high-impact events, including blooms of harmful cyanobacteria.


Subject(s)
Environmental Monitoring , Rivers , China , Chlorophyll A , Eutrophication , Lakes , Nitrogen/analysis , Phosphorus/analysis
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