620 research outputs found
Adverse outcome pathway and risks of anticoagulant rodenticides to predatory wildlife
Despite a long history of successful use, routine application of some anticoagulant rodenticides (ARs) may be at a crossroad due to new regulatory guidelines intended to mitigate risk. An adverse outcome pathway for ARs was developed to identify information gaps and end points to assess the effectiveness of regulations. This framework describes chemical properties of ARs, established macromolecular interactions by inhibition of vitamin K epoxide reductase, cellular responses including altered clotting factor processing and coagulopathy, organ level effects such as hemorrhage, organism responses with linkages to reduced fitness and mortality, and potential consequences to predator populations. Risk assessments have led to restrictions affecting use of some second-generation ARs (SGARs) in North America. While the European regulatory community highlighted significant or unacceptable risk of ARs to nontarget wildlife, use of SGARs in most EU member states remains authorized due to public health concerns and the absence of safe alternatives. For purposes of conservation and restoration of island habitats, SGARs remain a mainstay for eradication of invasive species. There are significant data gaps related to exposure pathways, comparative species sensitivity, consequences of sublethal effects, potential hazards of greater AR residues in genetically resistant prey, effects of low-level exposure to multiple rodenticides, and quantitative data on the magnitude of nontarget wildlife mortality
Chesapeake Bay Fish–Osprey (\u3ci\u3ePandion Haliaetus\u3c/i\u3e) Food Chain: Evaluation Of Contaminant Exposure And Genetic Damage
From 2011 to 2013, a large-scale ecotoxicological study was conducted in several Chesapeake Bay (USA) tributaries (Susquehanna River and flats, the Back, Baltimore Harbor/Patapsco Rivers, Anacostia/ middle Potomac, Elizabeth and James Rivers) and Poplar Island as a mid-Bay reference site. Osprey (Pandion haliaetus) diet and the transfer of contaminants from fish to osprey eggs were evaluated. The most bioaccumulative compounds (biomagnification factor\u3e5) included p,p’-dichlorodiphenyldichloroethylene (DDE), total polychlorinated biphenyls (PCBs), total polybrominated diphenyl ethers (PBDEs), and bromodiphenyl ether (BDE) congeners 47, 99, 100, and 154. This analysis suggested that alternative brominated flame retardants and other compounds (methoxytriclosan) are not appreciably biomagnifying. A multivariate analysis of similarity indicated that major differences in patterns among study sites were driven by PCB congeners 105, 128, 156, 170/190, and 189, and PBDE congeners 99 and 209. An integrative
redundancy analysis showed that osprey eggs from Baltimore Harbor/Patapsco River and the Elizabeth River had high residues of PCBs and p,p’-DDE, with PBDEs making a substantial contribution to overall halogenated contamination on the Susquehanna and Anacostia/middle Potomac Rivers. The redundancy analysis also suggested a potential relation between PBDE residues in osprey eggs and oxidative DNA damage in nestling blood samples. The results also indicate that there is no longer a discernible relation between halogenated contaminants in osprey eggs and their reproductive success in Chesapeake Bay. Osprey populations are thriving in much of the Chesapeake, with productivity rates exceeding those required to sustain a stable population
Understanding the Relationships between Tourists’ Emotional Experiences, Perceived Overall Image, Satisfaction, and Intention to Recommend
The purpose of this study is to empirically test an integrative model linking tourists' emotional experiences, perceived overall image, satisfaction, and intention to recommend. The model was tested using data collected from domestic tourists visiting Sardinia, Italy. Results show that tourists' emotional experiences act as antecedents of perceived overall image and satisfaction evaluations. In addition, overall image has a positive influence on tourist satisfaction and intention to recommend. The study expands current theorizations by examining the merits of emotions in tourist behavior models. From a practical perspective, the study offers important implications for destination marketers
Optical codeword demodulation with error rates below standard quantum limit using a conditional nulling receiver
The quantum states of two laser pulses---coherent states---are never mutually
orthogonal, making perfect discrimination impossible. Even so, coherent states
can achieve the ultimate quantum limit for capacity of a classical channel, the
Holevo capacity. Attaining this requires the receiver to make joint-detection
measurements on long codeword blocks, optical implementations of which remain
unknown. We report the first experimental demonstration of a joint-detection
receiver, demodulating quaternary pulse-position-modulation (PPM) codewords at
a word error rate of up to 40% (2.2 dB) below that attained with
direct-detection, the largest error-rate improvement over the standard quantum
limit reported to date. This is accomplished with a conditional nulling
receiver, which uses optimized-amplitude coherent pulse nulling, single photon
detection and quantum feedforward. We further show how this translates into
coding complexity improvements for practical PPM systems, such as in deep-space
communication. We anticipate our experiment to motivate future work towards
building Holevo-capacity-achieving joint-detection receivers.Comment: 6 pages, 4 figure
Chesapeake Bay Fish–Osprey (\u3ci\u3ePandion Haliaetus\u3c/i\u3e) Food Chain: Evaluation Of Contaminant Exposure And Genetic Damage
From 2011 to 2013, a large-scale ecotoxicological study was conducted in several Chesapeake Bay (USA) tributaries (Susquehanna River and flats, the Back, Baltimore Harbor/Patapsco Rivers, Anacostia/ middle Potomac, Elizabeth and James Rivers) and Poplar Island as a mid-Bay reference site. Osprey (Pandion haliaetus) diet and the transfer of contaminants from fish to osprey eggs were evaluated. The most bioaccumulative compounds (biomagnification factor\u3e5) included p,p’-dichlorodiphenyldichloroethylene (DDE), total polychlorinated biphenyls (PCBs), total polybrominated diphenyl ethers (PBDEs), and bromodiphenyl ether (BDE) congeners 47, 99, 100, and 154. This analysis suggested that alternative brominated flame retardants and other compounds (methoxytriclosan) are not appreciably biomagnifying. A multivariate analysis of similarity indicated that major differences in patterns among study sites were driven by PCB congeners 105, 128, 156, 170/190, and 189, and PBDE congeners 99 and 209. An integrative
redundancy analysis showed that osprey eggs from Baltimore Harbor/Patapsco River and the Elizabeth River had high residues of PCBs and p,p’-DDE, with PBDEs making a substantial contribution to overall halogenated contamination on the Susquehanna and Anacostia/middle Potomac Rivers. The redundancy analysis also suggested a potential relation between PBDE residues in osprey eggs and oxidative DNA damage in nestling blood samples. The results also indicate that there is no longer a discernible relation between halogenated contaminants in osprey eggs and their reproductive success in Chesapeake Bay. Osprey populations are thriving in much of the Chesapeake, with productivity rates exceeding those required to sustain a stable population
HLA-Identical Sibling Allogeneic Transplants versus Chemotherapy in Acute Myelogenous Leukemia with t(8;21) in First Complete Remission: Collaborative Study between the German AML Intergroup and CIBMTR
AbstractWe studied the role of HLA-matched sibling hematopoietic cell transplantation (HCT) in treating t(8;21) acute myelogenous leukemia (AML) in first remission. Outcomes of 118 patients receiving HCT and reported to the Center for International Blood and Marrow Transplant Research were compared with 132 similar patients receiving chemotherapy selected from 8 German AML Intergroup multicenter trials. Characteristics of the cohorts were similar except that chemotherapy recipients were significantly older. To adjust for time to treatment bias, outcomes were compared using left-truncated Cox regression models. Transplants were associated with higher treatment-related mortality (TRM; relative risk [RR] 6.76, 95% confidence interval [CI] 2.95-15.45, P < .001), lower relapse (RR 0.47, 95% CI 0.25-0.85, P = .01), and similar relapse-free survival (P = .2). Loss of sex chromosomes (LOS) in addition to t(8;21) had a negative impact on overall survival (OS) in patients receiving chemotherapy. Patients without LOS experienced shorter survival after HCT comparing to chemotherapy (RR 3.05, P = .02), whereas patients with LOS had similar survival regardless of postremission therapy. In both cohorts, white blood cell count (WBC) at diagnosis >25 × 109/L was associated with a higher relapse risk (RR = 2.09, P = .03), lower relapse-free (RR = 1.9, P = .008), and OS (RR = 1.91, P = .01). In this cohort of patients with t(8;21) AML, HCT did not improve OS, because reduction of relapse was offset by high TRM. In the group without LOS, survival after chemotherapy was far superior to HCT. These results suggest that patients with t(8;21) AML without poor prognostic factors have higher rates of survival after chemotherapy as a post remission therapy compared to HCT
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