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1.
Opt Express ; 27(15): 20567-20582, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31510148

RESUMO

The fabrication of hollow core microstructured fibers is significantly more complex than solid fibers due to the necessity to control the hollow microstructure with high precision during the draw. We present the first model that can recreate tubular anti-resonant hollow core fiber draws, and accurately predict the draw parameters and geometry of the fiber. The model was validated against two different experimental fiber draws and very good agreement was found. We identify a dynamic within the draw process that can lead to a premature and irreversible contact between neighboring capillaries inside the hot zone, and describe mitigating strategies. We then use the model to explore the tolerance of the draw process to unavoidable structural variations within the preform, and to study feasibility and limiting phenomena of increasing the produced yield. We discover that the aspect ratio of the capillaries used in the preform has a direct effect on the uniformity of drawn fibers. Starting from high precision preforms the model predicts that it could be possible to draw 100 km of fiber from a single meter of preform.

2.
Opt Express ; 27(17): 24072-24081, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31510301

RESUMO

We experimentally demonstrate a means to selectively enhance wavelength conversion of WDM channels on a 100 GHz grid exploiting nonlinear effects between the spatial modes of a few mode fiber. The selectivity of parametric gain is obtained by dispersion design of the fiber such that the inverse group velocity curves of the participating modes are parallel and their dispersion is suitably large. We describe both theoretically and experimentally the observed dependence of the idler gain profile on pump mode (quasi) degeneracy.

3.
J Clin Oncol ; : JCO1900354, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31465264

RESUMO

PURPOSE: Seasonal influenza vaccination is recommended for patients with cancer despite concerns of disease or treatment-associated immunosuppression. The objective of this study was to evaluate vaccine effectiveness (VE) against laboratory-confirmed influenza for patients with cancer. PATIENTS AND METHODS: We conducted an observational test-negative design study of previously diagnosed patients with cancer 18 years of age and older who underwent influenza testing during the 2010-2011 to 2015-2016 influenza seasons in Ontario, Canada. We linked individual-level cancer registry, respiratory virus testing, and health administrative data to identify the study population and outcomes. Vaccination status was determined from physician and pharmacist billing claims. We used multivariable logistic regression to estimate VE, adjusting for age, sex, rurality, income quintile, cancer characteristics, chemotherapy exposure, comorbidities, previous health care use, influenza season, and calendar time. RESULTS: We identified 26,463 patients with cancer who underwent influenza testing, with 4,320 test-positive cases (16%) and 11,783 (45%) vaccinated. Mean age was 70 years, 52% were male, mean time since diagnosis was 6 years, 69% had solid tumor malignancies, and 23% received active chemotherapy. VE against laboratory-confirmed influenza was 21% (95% CI, 15% to 26%), and VE against laboratory-confirmed influenza hospitalization was 20% (95% CI, 13% to 26%). For patients with solid tumor malignancies, VE was 25% (95% CI, 18% to 31%), compared with 8% (95% CI, -5% to 19%) for patients with hematologic malignancies (P = .015). Active chemotherapy usage did not significantly affect VE, especially among patients with solid tumor cancer. CONCLUSION: Our results support recommendations for influenza vaccination for patients with cancer. VE was decreased for patients with hematologic malignancies, and there was no significant difference in VE among patients with solid tumor cancer receiving active chemotherapy. Strategies to optimize influenza prevention among patients with cancer are warranted.

4.
Foot Ankle Int ; : 1071100719867942, 2019 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-31423824

RESUMO

BACKGROUND: The purpose of this article was to review the basic science pertaining to the harmful effects of cigarette smoke, summarize recent clinical outcome studies, and examine the benefits of smoking cessation and the efficacy of current smoking cessation strategies. METHODS: The literature concerning basic science, clinical outcomes, and smoking cessation was reviewed; over half (56%) of the 52 articles reviewed were published in the last 5 years. RESULTS: Smoking is associated with low bone mineral density, delayed fracture union, peri-implant bone loss, and implant failure. Orthopedic surgical patients who smoke have increased pain and lower overall patient satisfaction, along with significantly increased rates of wound healing complications. DISCUSSION/CONCLUSION: Active smoking is a significant modifiable risk factor and should be discontinued before foot and ankle surgery whenever possible. Orthopedic surgeons play an important role in educating patients on the effects of smoking and facilitating access to smoking cessation resources. LEVEL OF EVIDENCE: Level V, expert opinion.

5.
MBio ; 10(4)2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31387903

RESUMO

Global atmospheric loading of the climate-active gas nitrous oxide (N2O) continues to increase. A significant proportion of anthropogenic N2O emissions arises from microbial transformation of nitrogen-based fertilizers during denitrification, making microbial N2O emissions a key target for greenhouse gas reduction strategies. The genetic, physiological, and environmental regulation of microbially mediated N2O flux is poorly understood and therefore represents a critical knowledge gap in the development of successful mitigation approaches. We have previously mapped the transcriptional landscape of the model soil-denitrifying bacterium Paracoccus denitrificans Here, we show that a single bacterial small RNA (sRNA) can control the denitrification rate of P. denitrificans by stalling denitrification at nitrite reduction to limit production of downstream pathway intermediates and N2O emissions. Overexpression of sRNA-29 downregulates nitrite reductase and limits NO and N2O production by cells. RNA sequencing (RNA-seq) analysis revealed 53 genes that are controlled by sRNA-29, one of which is a previously uncharacterized GntR-type transcriptional regulator. Overexpression of this regulator phenocopies sRNA-29 overexpression and allows us to propose a model whereby sRNA-29 enhances levels of the regulator to repress denitrification under appropriate conditions. Our identification of a new regulatory pathway controlling the core denitrification pathway in bacteria highlights the current chasm in knowledge regarding genetic regulation of this pivotal biogeochemical process, which needs to be closed to support future biological and chemical N2O mitigation strategies.IMPORTANCE N2O is an important greenhouse gas and a major cause of ozone depletion. Denitrifying bacteria play vital roles in the production and consumption of N2O in many environments. Complete denitrification consists of the conversion of a soluble N-oxyanion, nitrate (NO3 -), to an inert gaseous N-oxide, dinitrogen (N2). Incomplete denitrification can occur if conditions are prohibitive, for example, under conditions of low soil copper concentrations, leading to emission of N2O rather than N2 Although enzymatically well characterized, the genetic drivers that regulate denitrification in response to environmental and physiological cues are not fully understood. This study identified a new regulatory sRNA-based control mechanism for denitrification in the model denitrifying bacterium P. denitrificans Overexpression of this sRNA slows the rate of denitrification. This report highlights that there are gaps in understanding the regulation of this important pathway which need to be filled if strategies for N2O mitigation can be rationally and carefully developed.

6.
Ann Surg Oncol ; 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31372868

RESUMO

BACKGROUND: Concern persists regarding percutaneous core needle biopsy (CNB) of a potentially malignant lesion of the retroperitoneum due to the perceived risk of immediate complications and adverse oncologic outcomes, including needle tract seeding (NTS). OBJECTIVE: The aim of this study was to evaluate the incidence of (1) early complications and (2) NTS following CNB of suspected retroperitoneal sarcoma (RPS). METHODS: Patients who underwent CNB of an RP mass with pre-biopsy suspicion of sarcoma were identified from a prospective database at two centers: (1) Princess Margaret Cancer Centre/Mount Sinai Hospital, Toronto (2009-2015); and (2) The Ottawa Hospital (1999-2015). Early complications, including bleeding, pain, infection, and organ injury, were recorded. Instances of NTS were identified from long-term follow-up of patients who underwent resection of primary RPS at these two centers after initial CNB (1996-2013). RESULTS: Of 358 percutaneous CNBs of suspected RPS performed over the study period, 7 (2.0%) resulted in minor bleeding with no transfusion, 3 (0.8%) resulted in significant pain, 1 (0.3%) resulted in unplanned admission to hospital for observation, and 1 (0.3%) resulted in a pneumothorax. There were no infections. In 203 patients who underwent resection of RPS following CNB, crude cumulative local recurrence was 24% at 5 years. At a median follow-up of 44 months, there was one case of NTS (approximately 0.5%). CONCLUSION: This large bi-institutional experience with CNB of an RP mass demonstrates that both the early complication rate and the incidence of NTS are very low. Physicians and patients can be reassured that the benefits of CNB in diagnosing sarcoma and determining its histologic subtype and grade far outweigh the risks.

7.
Ecology ; : e02863, 2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31398280

RESUMO

In 2014 a DNA-based phylogenetic study confirming the paraphyly of the grass subtribe Sporobolinae proposed the creation of a large monophyletic genus Sporobolus, including (among others) species previously included in the genera Spartina, Calamovilfa, and Sporobolus. Spartina species have contributed substantially (and continue contributing) to our knowledge in multiple disciplines, including ecology, evolutionary biology, molecular biology, biogeography, experimental ecology, biological invasions, environmental management, restoration ecology, history, economics, and sociology. There is no rationale so compelling to subsume the name Spartina as a subgenus that could rival the striking, global iconic history and use of the name Spartina for over 200 years. We do not agree with the subjective arguments underlying the proposal to change Spartina to Sporobolus. We understand the importance of both the objective phylogenetic insights and of the subjective formalized nomenclature and hope that by opening this debate we will encourage positive feedback that will strengthen taxonomic decisions with an interdisciplinary perspective. We consider that the strongly distinct, monophyletic clade Spartina should simply and efficiently be treated as the genus Spartina. This article is protected by copyright. All rights reserved.

8.
Epidemiology ; 2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31430266

RESUMO

BACKGROUND: When a water pipe breaks, contaminants can enter the drinking water system and cause waterborne illnesses such as acute gastrointestinal illness. In May 2010, a major water pipe broke near Boston, Massachusetts, and a boil water order was issued to nearly two million residents. METHODS: Using a case-crossover study design, we examined the association between the water pipe break and subsequent emergency department visits for acute gastrointestinal illness. We identified cases of illness according to ICD-9-CM diagnosis codes and selected control dates two weeks before and after each case. We estimated the risk of visiting the emergency department during the 0-3 and 4-7 days following the water pipe break using conditional logistic regression models. RESULTS: Our analysis included 5,726 emergency department visits for acute gastrointestinal illness from 3 April 2010 through 5 June 2010. Overall, there was a 1.3-fold increased odds for visiting the emergency department for acute gastrointestinal illness during the 0-3 days after the water pipe break (Odds Ratio, OR=1.3; 95% Confidence Interval, CI: 1.1-1.4) compared to referent dates selected two weeks before and after. During the 4-7 days after the break, the association diminished overall (OR=1.1; 95% CI: 0.96-1.2). However, in communities over 12 miles from the break, the 4-7 day association was elevated (OR= 1.4; 95% CI: 1.1-1.8). CONCLUSION: This study suggests that a major water pipe break was associated with emergency department visits for acute gastrointestinal illness, particularly during the 0-3 days after the break, when a boil water order was in effect.

9.
J Expo Sci Environ Epidemiol ; 29(5): 732, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31171829

RESUMO

A correction to this paper has been published and can be accessed via link at the top of the paper.

10.
Occup Environ Med ; 76(8): 511-518, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31167952

RESUMO

OBJECTIVES: Uranium miners in Príbram, Czech Republic were exposed to low and moderate levels of radon gas and other hazards. It is unknown whether these hazards increase the risk of mortality or cancer incidence when compared with the general Czech population. METHODS: A cohort of 16 434 male underground miners employed underground for at least 1 year between 1946 and 1976, and alive and residing in the Czech Republic in 1977, were followed for mortality and cancer incidence through 1992. We compared observed deaths and cancer incidence to expectation based on Czech rates. Standardised mortality ratios (SMRs), standardised incidence ratios (SIRs) and causal mortality ratios were calculated. RESULTS: Underground workers in the Príbram mines had higher rates of death than expected due to all causes (SMR=1.23, 95% CI 1.20 to 1.27), all cancers (SMR=1.52, 95% CI 1.44 to 1.60), lung cancer (SMR=2.12, 95% CI 1.96 to 2.28) and extrathoracic cancer (SMR=1.41, 95% CI 1.15 to 1.77). Similar excess was observed in cancer incidence analyses, with the addition of stomach cancer (SIR=1.37, 95% CI 1.11 to 1.63), liver cancer (SIR=1.70, 95% CI 1.16 to 2.25) and rectal cancer (SIR=1.41, 95% CI 1.16 to 1.66). The SIR was elevated for all leukaemias (SIR=1.51, 95% CI 1.08 to 2.07) and for lymphatic and haematopoietic cancers combined (SIR=1.31, 95% CI 1.05 to 1.61), but results for specific subtypes were imprecise. Deaths due to hazardous mining conditions resulted in 0.33 person-years of life lost per miner. CONCLUSIONS: Occupational exposure to the Príbram mines resulted in excess cancers at several sites, including sites previously linked to radon and uranium exposure. Incidence analyses showed relative excess of several additional cancer subtypes.

11.
Vaccine ; 37(31): 4392-4400, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31221563

RESUMO

BACKGROUND: Linking data on laboratory specimens collected during clinical practice with health administrative data permits highly powered vaccine effectiveness (VE) studies to be conducted at relatively low cost, but bias from using convenience samples is a concern. We evaluated the validity of using such data for estimating VE. METHODS: We created the Flu and Other Respiratory Viruses Research (FOREVER) Cohort by linking individual-level data on respiratory virus laboratory tests, hospitalizations, emergency department visits, and physician services. For community-dwelling adults aged > 65 years, we assessed the presence and magnitude of information and selection biases, generated VE estimates under various conditions, and compared our VE estimates with those from other studies. RESULTS: We included 65,648 unique testing episodes obtained from 54,434 individuals during the 2010-11 to 2015-16 influenza seasons. To examine information bias, we found the proportion testing positive for influenza for patients with unknown interval from illness onset to specimen collection was more similar to patients for whom illness onset date was ≤ 7 days before specimen collection than to patients for whom illness onset was > 7 days before specimen collection. To assess the presence of selection bias, we found the likelihood of influenza testing was comparable between vaccinated and unvaccinated individuals, although the adjusted odds ratios were significantly greater than 1 for some healthcare settings and during some influenza seasons. Over 6 seasons, VE estimates ranged between 36% (95%CI, 27-44%) in 2010-11 and 5% (95%CI, -2, 11%) in 2014-15. VE estimates were similar under a range of conditions, but were consistently higher when accounting for misclassification of vaccination status through a quantitative sensitivity analysis. VE estimates from the FOREVER Cohort were comparable to those from other studies. CONCLUSIONS: Routinely collected laboratory and health administrative data contained in the FOREVER Cohort can be used to estimate influenza VE in community-dwelling older adults.

12.
Clin Ther ; 41(6): 1020-1028, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31084993

RESUMO

PURPOSE: The purpose of this study was to investigate potential differences by sex in the demographic and clinical characteristics of patients treated utilizing a sepsis electronic bundle order set. Risk factors for in-hospital mortality were also assessed. METHODS: Data on patients in whom the sepsis order set was initiated in the emergency department over a 16-month period were entered into the hospital database. Data were analyzed for differences by sex in demographic and clinical factors, treatment modalities, and in-hospital mortality. The Bonferroni correction was applied to account for multiple comparisons; α was set at 0.006 for sex differences. FINDINGS: A total of 2204 patients were included. Male and female cohorts were similar with regard to a variety of demographic and clinical factors, including age, Emergency Severity Index (ESI) levels 1 and 2, time to disposition, appropriateness of antibiotics, and total fluids given by weight. The ESI is an assessment score ranging from 1 to 5 (1 is emergent). There were modest differences in the source of infection (genitourinary was 4% more common in women; P = 0.03) and mode of arrival (men were 4% more likely to arrive by ambulance; P = 0.03). These differences did not achieve our predefined α of 0.006 when the Bonferroni correction was applied. Factors associated with in-hospital mortality were advanced age, arrival by ambulance, and an ESI level of 1 or 2 (all, P < 0.01). IMPLICATIONS: Women were more likely to have a genitourinary cause of sepsis and less likely to arrive by ambulance. Risk factors of in-hospital mortality were older age, arrival by ambulance, and an ESI level of 1 or 2, but not sex.

13.
Am J Ind Med ; 62(6): 471-477, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31087402

RESUMO

BACKGROUND: While asbestos has long been known to cause mesothelioma, quantitative exposure-response data on the relation of mesothelioma risk and exposure to chrysotile asbestos are sparse. METHODS: Quantitative relationships of mortality from mesothelioma and pleural cancer were investigated in an established cohort of 5397 asbestos textile manufacturing workers in North Carolina, USA. Eligible workers were those employed between 1950 and 1973 with mortality follow-up through 2003. Individual exposure to chrysotile fibres was estimated on the basis of 3420 air samples covering the entire study period linked to work history records. Exposure coefficients adjusted for age, race, and time-related covariates were estimated by Poisson regression. RESULTS: Positive, statistically significant associations were observed between mortality from all pleural cancer (including mesothelioma) and time since first exposure (TSFE) to asbestos (rate ratio [RR], 1.19; 95% confidence interval [CI], 1.06-1.34 per year), duration of exposure, and cumulative asbestos fibre exposure (RR, 1.15; 95% CI, 1.04-1.28 per 100 f-years/mL; 10-year lag). Analyses of the shape of exposure-response functions suggested a linear relationship with TSFE and a less-than-linear relationship with cumulative exposure. Restricting the analysis to years when mesothelioma was coded as a unique cause of death yielded stronger but less precise associations. CONCLUSIONS: These observations support with quantitative data the conclusion that chrysotile causes mesothelioma and encourage exposure-response analyses of mesothelioma in other cohorts exposed to chrysotile.

14.
Am J Ind Med ; 62(7): 568-579, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31104330

RESUMO

BACKGROUND: Use of worker's compensation (WC) as payer underestimates work-related (WR) injuries. We evaluated three methods to identify WR injuries: WC as payer, ICD-9-CM work-status codes E000.0/E000.1, and other ICD-9-CM external cause codes. METHODS: We identified injury-related emergency department visits from North Carolina's syndromic surveillance system (2010-2013). Characteristics were compared by indicator. We manually reviewed 800 admission notes to confirm if the visit was WR or non-WR; WR keywords from the review were applied to all visits. RESULTS: 133 156 injury-related visits (age, 16 years or older) were identified: WC = 69%, work-status codes = 18%, other ICD-9-CM codes = 13%. Among manually reviewed visits: few visits identified by WC (0.3%) or work-status codes (2%) were non-WR, while 12% of other ICD-9-CM code identified visits were non-WR; 53%, 46%, and 31% of visits identified by WC, work-status codes, and other ICD-9-CM codes were WR, respectively. CONCLUSIONS: Findings support use of WC and work-status codes to capture WR injuries; other ICD-9-CM codes should be used with caution or in combination with other indicators.

15.
Environ Int ; 127: 764-772, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31029031

RESUMO

BACKGROUND: Occupational exposure to animal production is associated with chronic bronchitis symptoms; however, few studies consider associations with chronic obstructive pulmonary disease (COPD). We estimated associations between animal production activities and prevalence of self-reported COPD among farmers in the Agricultural Health Study. METHODS: During a 2005-2010 interview, farmers self-reported information about: their operations (i.e., size, type, number of animals, insecticide use), respiratory symptoms, and COPD diagnoses (i.e., COPD, chronic bronchitis, emphysema). Operations were classified as small or medium/large based on regulatory definitions. Farmers were classified as having a COPD diagnosis, chronic bronchitis symptoms (cough and phlegm for ≥3 months during 2 consecutive years), or both. Polytomous logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI). RESULTS: Of 22,491 participating farmers (median age: 59 years), 922 (4%) reported a COPD diagnosis only, 254 (1%) reported a diagnosis and symptoms, and 962 (4%) reported symptoms only. Compared to raising no commercial animals, raising animals on a medium/large operation was positively associated with chronic bronchitis symptoms with (OR: 1.59; 95% CI: 1.16, 2.18) and without a diagnosis (OR: 1.69; 95% CI: 1.42, 2.01). Ever use of multiple organophosphates, carbaryl, lindane, and permethrin were positively associated with chronic bronchitis symptoms. CONCLUSION: Animal production work, including insecticide use, was positively associated with chronic bronchitis symptoms; but not consistently with COPD diagnosis alone. Our results support the need for further investigation into the role of animal production-related exposures in the etiology of COPD and better respiratory protection for agricultural workers.

16.
J Emerg Med ; 57(1): 114-117, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31027991

RESUMO

BACKGROUND: Efficacy of medical student substance use interventions in the emergency department (ED) setting remains unstudied. OBJECTIVE: In this pilot study, we set out to determine whether medical students could perform a brief motivational interview for substance use in the ED. METHODS: At two hospitals, medical students utilized motivational interviewing skills taught by their medical school curriculum and administered a substance use intervention to ED patients who met the study definition of unhealthy substance use. RESULTS: In 6 weeks, medical students gave a brief intervention to 102 subjects. The mean age of the subjects was 46.9 (standard deviation 15.6) years. The majority, 86 (86.3%) identified as white. Fifty-four (52.9%) identified as male. Eighty of 102 (78.4%) participants completed a phone follow-up assessment. Of the 69 smokers, 11 (15.9%) reported attempting to quit or quitting completely. Of the 33 with high-risk alcohol use, 11 (33.3%) were abstaining completely from alcohol use and an additional 12 (36.4%) reported a decrease in alcohol daily consumption (measured in drinks per day). Warm hand-off success for street drugs or at-risk alcohol use was 13.6% for those who received an intervention. CONCLUSIONS: It is feasible for medical students to perform a substance use intervention in the ED setting. Medical student contributions as a part of the team response to this public health crisis provide an opportunity for further discussion and research.

17.
Biol Rev Camb Philos Soc ; 94(4): 1477-1501, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30974048

RESUMO

Non-native tree (NNT) species have been transported worldwide to create or enhance services that are fundamental for human well-being, such as timber provision, erosion control or ornamental value; yet NNTs can also produce undesired effects, such as fire proneness or pollen allergenicity. Despite the variety of effects that NNTs have on multiple ecosystem services, a global quantitative assessment of their costs and benefits is still lacking. Such information is critical for decision-making, management and sustainable exploitation of NNTs. We present here a global assessment of NNT effects on the three main categories of ecosystem services, including regulating (RES), provisioning (PES) and cultural services (CES), and on an ecosystem disservice (EDS), i.e. pollen allergenicity. By searching the scientific literature, country forestry reports, and social media, we compiled a global data set of 1683 case studies from over 125 NNT species, covering 44 countries, all continents but Antarctica, and seven biomes. Using different meta-analysis techniques, we found that, while NNTs increase most RES (e.g. climate regulation, soil erosion control, fertility and formation), they decrease PES (e.g. NNTs contribute less than native trees to global timber provision). Also, they have different effects on CES (e.g. increase aesthetic values but decrease scientific interest), and no effect on the EDS considered. NNT effects on each ecosystem (dis)service showed a strong context dependency, varying across NNT types, biomes and socio-economic conditions. For instance, some RES are increased more by NNTs able to fix atmospheric nitrogen, and when the ecosystem is located in low-latitude biomes; some CES are increased more by NNTs in less-wealthy countries or in countries with higher gross domestic products. The effects of NNTs on several ecosystem (dis)services exhibited some synergies (e.g. among soil fertility, soil formation and climate regulation or between aesthetic values and pollen allergenicity), but also trade-offs (e.g. between fire regulation and soil erosion control). Our analyses provide a quantitative understanding of the complex synergies, trade-offs and context dependencies involved for the effects of NNTs that is essential for attaining a sustained provision of ecosystem services.

18.
Chemosphere ; 227: 34-42, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30981968

RESUMO

Solid waste and leachate samples from bench-scale anaerobic bioreactors and flushing bioreactors (FBs), containing mature waste were characterized using Fourier Transform Infrared Spectroscopy (FTIR) to provide a better understanding of the changes in waste characteristics when waste transitions from mature to stabilized. Humic acid (HA) extracted from mature waste and waste removed from the FBs were characterized using FTIR and 13C nuclear magnetic resonance. FBs were operated under three different treatment scenarios (flushing with clean water, recirculation of leachate treated by chemical oxidation, and recirculation of leachate treated by chemical oxidation with waste aeration. FTIR spectra of FB waste and leachate supported the stabilization of waste that occurred after the additional treatment. There was a shift in the dominance of organic to inorganic functional groups when compared to changes in conventional parameters that aligned with published values on waste stability. HA extracted from the mature waste were dominated by aliphatic carbon and aromatic carbon was less intense. Treatment by flushing resulted in a decrease in aliphatic carbon and an increase in aromatic carbon. HA extracted from reactors with oxidized leachate recirculation and aeration decreased in aliphatic carbon content, with minimal change in aromatic carbon. Therefore, the additional treatment did not result in an increase in the reactivity potential of the HA which aligns with FTIR and principal component analysis. Results suggest that spectroscopic techniques could be used to assess the stability of waste samples as opposed to more time-consuming analyses.


Assuntos
Eliminação de Resíduos/métodos , Resíduos Sólidos/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise , Reatores Biológicos , Análise de Fourier , Substâncias Húmicas/análise
19.
Environ Health Perspect ; 127(4): 47006, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31009265

RESUMO

BACKGROUND: Although styrene is an established neurotoxicant at occupational exposure levels, its neurotoxicity has not been characterized in relation to general population exposures. Further, occupational research to date has focused on central nervous system impairment. OBJECTIVE: We assessed styrene-associated differences in sensory and motor function among Gulf coast residents. METHODS: We used 2011 National Air Toxics Assessment estimates of ambient styrene to determine exposure levels for 2,956 nondiabetic Gulf state residents enrolled in the Gulf Long-term Follow-up Study, and additionally measured blood styrene concentration in a subset of participants 1 to 2 y after enrollment ([Formula: see text]). Participants completed an enrollment telephone interview and a comprehensive test battery to assess sensory and motor function during a clinical follow-up exam 2 to 4 y later. Detailed covariate information was ascertained at enrollment via telephone interview. We used multivariate linear regression to estimate continuous differences in sensory and motor function, and log-binomial regression to estimate prevalence ratios for dichotomous outcomes. We estimated associations of both ambient and blood styrene exposures with sensory and motor function, independently for five unique tests. RESULTS: Those participants in the highest 25% vs. lowest 75% of ambient exposure and those in the highest 10% vs. lowest 90% of blood styrene had slightly diminished visual contrast sensitivity. Mean vibrotactile thresholds were lower among those in the highest vs. lowest quartile of ambient styrene and the highest 10% vs. lowest 90% of blood styrene ([Formula: see text] log microns; 95% CI: [Formula: see text], [Formula: see text] and [Formula: see text] log microns; 95% CI: [Formula: see text], [Formula: see text], respectively). The highest vs. lowest quartile of ambient styrene was associated with significantly poorer postural stability, and (unexpectedly) with significantly greater grip strength. DISCUSSION: We observed associations between higher styrene exposure and poorer visual, sensory, and vestibular function, though we did not detect associations with reduced voluntary motor system performance. Associations were more consistent for ambient exposures, but we also found notable associations with measured blood styrene. https://doi.org/10.1289/EHP3954.

20.
Proc Biol Sci ; 286(1897): 20182477, 2019 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-30963833

RESUMO

Biological invasions are on the rise globally. To reduce future invasions, it is imperative to determine the naturalization potential of species. Until now, screening approaches have relied largely on species-specific functional feature data. Such information is, however, time-consuming and expensive to collect, thwarting the screening of large numbers of potential invaders. We propose to resolve such data limitations by developing indicators of establishment success of alien species that can be readily derived from open-access databases. These indicators describe key features of successfully established aliens, including estimates of potential range size, niche overlap with human-disturbed environments, and proxies of species traits related to their palaeoinvasions and local dominance capacities. We demonstrate the utility of this new approach by applying it to two large and highly invasive plant groups: Australian acacias and eucalypts. Our results show that these indicators robustly predict establishment successes and failures in each clade independently, and that they can cross-predict establishment in these two clades. Interestingly, the indicator identified as most important was species potential range size on Earth, a variable too rarely considered as a predictor. By successfully identifying key features that predispose Australian plants to naturalize, we provide an objective and cost-effective protocol for flagging high-risk introductions.

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