To examine the effects of environmentally realistic fipronil concentrations on estuarine ecosystems, replicated mesocosms containing intact marsh plots and seawater were exposed to three treatments ...of fipronil (150, 355, and 5000
ng/L) and a Control. Juvenile fish (
Cyprinidon variegatus), juvenile clams (
Mercenaria mercenaria), oysters (
Crassostrea virginica), and grass shrimp (
Palaemonetes pugio) were added prior to fipronil in an effort to quantify survival, growth, and the persistence of toxicity during the planned 28-day exposure. Results indicated that there were no fipronil-associated effects on the clams, oysters, or fish. Shrimp were sensitive to the highest two concentrations (40% survival at 355
ng/L and 0% survival at 5000
ng/L). Additionally, the highest fipronil treatment (5000
ng/L) was toxic to shrimp for 6 weeks post dose. These results suggest that fipronil may impact shrimp populations at low concentrations and further use in coastal areas should be carefully assessed.
This study investigated the concentrations and potential toxicity of polycyclic aromatic hydrocarbons (PAHs) associated with highway runoff into adjacent estuarine wetlands from road segments ...representing three levels of average daily traffic (ADT): low (<5,000 ADT), moderate (10,000-15,000 ADT), and high use (>25,000 ADT) based on SC Department of Transportation data. Sediments from three estuarine wetland habitats (tidal creeks, Spartina marsh, and mud flats) adjacent to these road segments were sampled to represent nine highway use class/habitat type combinations. Surficial sediments were collected at 3, 25, and 50 meters from the upland/wetland interface along transects established perpendicular to the road at each site, with additional samples taken from the road berm. Average PAH concentrations, representing 25 compounds, ranged from 3.9 to 11,000 ng/g dry weight. Berm samples had significantly greater total PAH concentrations than samples taken in any of the wetland habitats. Average total PAH concentrations decreased with increasing distance from the road berm within the wetland habitats sampled, but the differences were not statistically significant. Average total PAH concentrations also were not significantly different among the wetland habitats compared. Analysis of PAH profiles indicated that the PAH source was dominated by pyrogenic combustion products rather than from petrogenic sources. This, combined with the presence of dibenzothio-phene, which is a tire oxidation product, indicated that the primary source of PAHs was related to vehicles. Two sites with total PAH concentrations exceeding published bioeffects levels were resampled for bioassay tests using the amphipod Ampelisca verrilli, the polychaete Streblospio benedicti, and the clam, Mercenaria mercenaria, with the first two assays conducted under UV lighting since previous studies had demonstrated enhanced UV toxicity of PAHs for these species. No toxicity was observed in the amphipod or polychaete assays. Toxicity was observed in the juvenile clam assay at one site, possibly due to the combined effects of PAHs and other contaminants present.
Abstract
We present a strongly interacting quadruple system associated with the K2 target EPIC 220204960. The K2 target itself is a Kp = 12.7-mag star at Teff ≃ 6100 K, which we designate as ‘B-N’ ...(blue northerly image). The host of the quadruple system, however, is a Kp ≃ 17-mag star with a composite M-star spectrum, which we designate as ‘R-S’ (red southerly image). With a 3.2-arcsec separation and similar radial velocities and photometric distances, ‘B-N’ is likely physically associated with ‘R-S’, making this a quintuple system, but that is incidental to our main claim of a strongly interacting quadruple system in ‘R-S’. The two binaries in ‘R-S’ have orbital periods of 13.27 and 14.41 d, respectively, and each has an inclination angle of ≳89°. From our analysis of radial-velocity (RV) measurements, and of the photometric light curve, we conclude that all four stars are very similar with masses close to 0.4 M⊙. Both of the binaries exhibit significant eclipse-timing variations where those of the primary and secondary eclipses ‘diverge’ by 0.05 d over the course of the 80-d observations. Via a systematic set of numerical simulations of quadruple systems consisting of two interacting binaries, we conclude that the outer orbital period is very likely to be between 300 and 500 d. If sufficient time is devoted to RV studies of this faint target, the outer orbit should be measurable within a year.
Propofol is an intravenous sedative hypnotic agent which rapidly and reliably causes loss of consciousness. It is also associated with a quick and 'smooth' recovery, which distinguishes it from many ...of the more traditional anaesthetic regimens. Like other intravenous agents, propofol is both a cardiovascular and a respiratory depressant; however, the risk of these effects can be lessened by appropriate dosage adjustment or patient management. Anaphylaxis with propofol is rare. Propofol anaesthesia in day case surgery is consistently associated with a quicker early recovery than other intravenous agents and the more traditional anaesthetic regimens. Savings in time to discharge were more variable compared with these regimens, although propofol was commonly associated with less post-operative nausea and vomiting in this period. In the future, the relative benefits of propofol compared with the newer volatile agents (desflurane and sevoflurane) and propofol/volatile agent combinations need to be examined in this clinical setting. There is now clinical experience with propofol in major surgical procedures including cardiac and neurosurgery. Propofol has also been investigated as a sedative accompanying regional or local anaesthesia for diagnostic and therapeutic procedures, and in other clinical settings (ophthalmic surgery, cardioversion and electroconvulsive therapy). The unique antiemetic, antiepileptic and antipruritic effects of propofol may further broaden its appeal. As a result of its favourable recovery profile, propofol holds a central place in day case surgery anaesthesia. Accumulating clinical experience in cardiac and neurosurgery suggests that the full potential of propofol has yet to be realised.
Eprinomectin (MK-397 or 4″-epi-acetylamino-4″-deoxy-avermectin B
1) is a novel avermectin selected for development as a topical endectocide for all cattle, including lactating dairy cows. Herein, we ...show its anthelmintic, insecticidal and miticidal activity. To determine its anthelmintic capabilities, eprinomectin was tested topically on Jersey calves at 0.08, 0.2, or 0.5 mg kg
−1 in a probe formulation against experimental infections of adult
Haemonchus placei, Ostertagia ostertagi, Trichostrongylus axei, T. colubriformis, Cooperia oncophora, C. punctata, Nematodirus helvetianus,
Oesophagostomum radiatum and
Dictyocaulus viviparus. Eprinomectin removed ≥99% and ≥98% of the adult stage of every species at the 0.5 and 0.2 mg kg
−1 dosage levels, respectively. The lowest dosage (0.08 mg kg
−1) produced maximal or near maximal efficacy against most of the adult endoparasites with the exception of
T. colubriformis (87%) and
C. oncophora (88%). In a separate test, eprinomectin was evaluated topically against the immature stages of these species at the same dosages. Results showed ≥99% and ≥98% removal of the immature stages of each species at the 0.5 and 0.2 mg kg
−1 dosage levels, respectively. The 0.08 mg kg
−1 dosage maintained ≥97% efficacy against 6 species with reduced activity against
H. placei (42%) and
N. helvetianus (66%). For ectoparasites, eprinomectin was tested topically at 0.16, 0.24, 0.32 or 0.5 mg kg
−1 on mixed breed cattle naturally infested with the sucking louse,
Linognathus vituli. Complete elimination of lice at all dosages was observed by day 14. Topical delivery of eprinomectin at 0.16, 0.24, 0.32 or 0.5 mg kg
−1 to Holstein calves experimentally challenged with horn fly,
Haematobia irritans, produced 100% efficacy to challenge by week 2 post-treatment in all dosage groups and 94% and 99% efficacy to challenge at the 0.32 and 0.5 mg kg
−1 dosage groups, respectively, at week 4. Topical delivery of eprinomectin at 0.16, 0.24 or 0.5 mg kg
−1 to Deutsches Fleckvieh cattle infested with mange mites,
Chorioptes bovis, produced ≥95% control at all dosage levels by day 14 post-treatment and was maintained at or near this efficacious level for the 6-week duration of the trial. No adverse reaction was observed in any animal in any of these tests. In summary, these experimental data indicate that eprinomectin is an excellent broad-spectrum endectocide for cattle and is suitable for topical delivery.
Transport accounts for 24% of global CO2 emissions from fossil fuels. Governments face challenges in developing feasible and equitable mitigation strategies to reduce energy consumption and manage ...the transition to low-carbon transport systems. To meet the local and global transport emission reduction targets, policymakers need more realistic/sophisticated future projections of transport demand to better understand the speed and depth of the actions required to mitigate greenhouse gas emissions. In this paper, we argue that the lack of access to high-quality data on the current and historical travel demand and interdisciplinary research hinders transport planning and sustainable transitions toward low-carbon transport futures. We call for a greater interdisciplinary collaboration agenda across open data, data science, behaviour modelling, and policy analysis. These advancemets can reduce some of the major uncertainties and contribute to evidence-based solutions toward improving the sustainability performance of future transport systems. The paper also points to some needed efforts and directions to provide robust insights to policymakers. We provide examples of how these efforts could benefit from the International Transport Energy Modeling Open Data project and open science interdisciplinary collaborations.
Aromatase and COX-2 expression in human breast cancers Brodie, A.M.H; Lu, Q; Long, B.J ...
Journal of steroid biochemistry and molecular biology,
12/2001, Letnik:
79, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
We have investigated aromatase and the inducible cyclooxygenase COX-2 expression using immunocytochemistry in tumors of a series of patients with advanced breast cancer treated with aromatase ...inhibitors. Aromatase was expressed in 58/102 breast cancers. This is similar to the percentage previously reported for aromatase activity. Interestingly, aromatase was expressed in a variety of cell types, including tumor, stromal, adipose, and endothelial cells. Since prostaglandin E
2 is known to regulate aromatase gene expression and is the product of COX-2, an enzyme frequently overexpressed in tumors, immunocytochemistry was performed on the tissue sections using a polyclonal antibody to COX-2. Aromatase was strongly correlated (
P<0.001) with COX-2 expression. These results suggest that PGE
2 produced by COX-2 in the tumor may be important in stimulating estrogen synthesis in the tumor and surrounding tissue. No correlation was observed between aromatase or COX-2 expression and the response of the patients to aromatase inhibitor treatment. However, only 13 patients responded. Nine of these patients were aromatase positive. Although similar to responses in other studies, this low response rate to second line treatment suggests that tumors of most patients were no longer sensitive to the effects of estrogen. Recent clinical studies suggest that greater responses occur when aromatase inhibitors are used as first line treatment. In the intratumoral aromatase mouse model, expression of aromatase in tumors is highly correlated with increased tumor growth. First line treatment with letrozole was effective in all animals treated and was more effective than tamoxifen in suppressing tumor growth. Letrozole was also effective in tumors failing to respond to tamoxifen, consistent with clinical findings. In addition, the duration of response was significantly longer with the aromatase inhibitor than with tamoxifen, suggesting that aromatase inhibitors may offer better control of tumor growth than this antiestrogen.
PURPOSEThis study aimed to determine if preexisting respiratory muscle fatigue (RMF) alters motoneuronal output, locomotor muscle fatigue, and cycling performance.
METHODSEight trained male cyclists ...performed 5-km cycling time trials after a resistive breathing task that induced RMF and under control conditions (CON). Motoneuronal output was estimated using vastus lateralis surface electromyography, and locomotor muscle fatigue was quantified as the change in potentiated quadriceps twitch force from preexercise to postexercise.
RESULTSTime to complete the time trial was 1.9% ± 0.9% longer in RMF compared with CON (P < 0.001). Estimated motoneuronal output was lower in RMF compared with CON during 1 km (45% ± 11% vs 53% ± 13%, P = 0.004) and 2 km (45% ± 14% vs 51% ± 14%, P = 0.008), but was not different thereafter. Ventilation was lower in RMF compared with CON during 1 km (114 ± 19 vs 135 ± 24 L·min, P = 0.003) and 2 km (136 ± 23 vs 152 ± 31 L·min, P = 0.009); however, ratings of dyspnea were similar. After the 5-km time trial, locomotor muscle fatigue was attenuated in RMF compared with CON (−22% ± 6%, vs −28% ± 7%, P = 0.02).
CONCLUSIONSAlterations to dyspnea for a given ventilation seem to have constrained power output during cycling exercise, thereby limiting the development of locomotor muscle fatigue. These findings indicate that the respiratory system is an integral component in a global feedback loop that regulates exercise performance and the development of locomotor muscle fatigue.
A multiyear study in the C-111 canal system and associated sites in Florida Bay was undertaken to determine the potential pesticide risk that exists in South Florida. After the examination of ...extensive pesticide concentration data in surface water, tissues, and semipermeable membrane devices (SPMDs), canal contamination seems to be derived from the extensive agricultural production that drains into the C-111 canal. The results of this study indicate that runoff from agricultural processes led to quantifiable pesticide residues in both canal and bay surface water, which occasionally exceeded current water quality criteria. The major pesticide of concern was endosulfan, which was detected at 100% of the sites sampled. Endosulfan exposure did not cause any acute effects in fish and crustaceans deployed in field bioassays. Chronic effects were observed in copepods, clams, and oysters but could not be attributed to endosulfan exposure. The decision to alter the C-111 canal flow and allow increased freshwater flow into the adjacent Everglades National Park may result in discharges of pesticides into the Everglades. Continued monitoring in this area is needed during this change in flow regime. Keywords: Endosulfan; Florida Bay; South Florida; semipermeable membrane devices; oysters; copepods; clams
Fecal pollution may adversely impact water quality in coastal ecosystems. The goal of this study was to determine whether cattle were a source of fecal pollution in a South Carolina watershed. ...Surface water samples were collected in June 2002 and February through March 2003 in closed shellfish harvesting waters of Toogoodoo Creek in Charleston County, SC. Fecal coliform concentrations in 70 % of the water samples taken for this study exceeded shellfish harvesting water standards. Ribotyping was performed in order to identify animal sources contributing to elevated fecal coliform levels.
Escherichia coli
isolates (
n
= 253) from surface water samples were ribotyped and compared to a ribotype library developed from known sources of fecal material. Ribotypes from water samples that matched library ribotypes with 90 % maximum similarity or better were assigned to that source. Less than half of the unknown isolates (38 %) matched with library isolates. About half (53 %) of the matched ribotypes were assigned to cattle isolates and 43 % to raccoon. Ribotyping almost exclusively identified animal sources. While these results indicate that runoff from cattle farms was a likely source of fecal pollution in the watershed, wildlife also contributed. Given the small size of the library, ribotyping was moderately useful for determining the impact of adjacent cattle farms on Toogoodoo Creek. Increasing the number and diversity of the wildlife sources from the area would likely increase the usefulness of the method.
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