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1.
Minh Thac Nguyen Ryan Denniston Hien Thi Thu Nguyen Tuan Anh Hoang Hana Ross Anthony D. So 《PloS one》2014,9(1)
Illicit trade carries the potential to magnify existing tobacco-related health care costs through increased availability of untaxed and inexpensive cigarettes. What is known with respect to the magnitude of illicit trade for Vietnam is produced primarily by the industry, and methodologies are typically opaque. Independent assessment of the illicit cigarette trade in Vietnam is vital to tobacco control policy. This paper measures the magnitude of illicit cigarette trade for Vietnam between 1998 and 2010 using two methods, discrepancies between legitimate domestic cigarette sales and domestic tobacco consumption estimated from surveys, and trade discrepancies as recorded by Vietnam and trade partners. The results indicate that Vietnam likely experienced net smuggling in during the period studied. With the inclusion of adjustments for survey respondent under-reporting, inward illicit trade likely occurred in three of the four years for which surveys were available. Discrepancies in trade records indicate that the value of smuggled cigarettes into Vietnam ranges from $100 million to $300 million between 2000 and 2010 and that these cigarettes primarily originate in Singapore, Hong Kong, Macao, Malaysia, and Australia. Notable differences in trends over time exist between the two methods, but by comparison, the industry estimates consistently place the magnitude of illicit trade at the upper bounds of what this study shows. The unavailability of annual, survey-based estimates of consumption may obscure the true, annual trend over time. Second, as surveys changed over time, estimates relying on them may be inconsistent with one another. Finally, these two methods measure different components of illicit trade, specifically consumption of illicit cigarettes regardless of origin and smuggling of cigarettes into a particular market. However, absent a gold standard, comparisons of different approaches to illicit trade measurement serve efforts to refine and improve measurement approaches and estimates. 相似文献
2.
Cytochrome b561 spectral changes associated with electron transfer in chromaffin-vesicle ghosts 总被引:1,自引:0,他引:1
The involvement of cytochrome b561, an integral membrane protein, in electron transfer across chromaffin-vesicle membranes is confirmed by changes in its redox state observed as changes in the absorption spectrum occurring during electron transfer. In ascorbate-loaded chromaffin-vesicle ghosts, cytochrome b561 is nearly completely reduced and exhibits an absorption maximum at 561 nm. When ferricyanide is added to a suspension of these ghosts, the cytochrome becomes oxidized as indicated by the disappearance of the 561 nm absorption. If a small amount of ferricyanide is added, it becomes completely reduced by electron transfer from intravesicular ascorbate. When this happens, cytochrome b561 returns to its reduced state. If an excess of ferricyanide is added, the intravesicular ascorbate becomes exhausted and the cytochrome b561 remains oxidized. The spectrum of these absorbance changes correlates with the difference spectrum (reduced-oxidized) of cytochrome b561. Cytochrome b561 becomes transiently oxidized when ascorbate oxidase is added to a suspension of ascorbate-loaded ghosts. Since dehydroascorbate does not oxidize cytochrome b561, it is likely that oxidation is caused by semidehydroascorbate generated by ascorbate oxidase acting on free ascorbate. This suggests that cytochrome b561 can reduce semidehydroascorbate and supports the hypothesis that the function of cytochrome b561 in vivo is to transfer electrons into chromaffin vesicles to reduce internal semidehydroascorbate to ascorbate. 相似文献
3.
W. Kelley Thomas J. T. Vida Linda M. Frisse Manuel Mundo James G. Baldwin 《Journal of nematology》1997,29(3):250-254
To effectively integrate DNA sequence analysis and classical nematode taxonomy, we must be able to obtain DNA sequences from formalin-fixed specimens. Microdissected sections of nematodes were removed from specimens fixed in formalin, using standard protocols and without destroying morphological features. The fixed sections provided sufficient template for multiple polymerase chain reaction-based DNA sequence analyses. 相似文献
4.
Petronela Weisová Ujval Anilkumar Caitriona Ryan Caoimhín G. Concannon Jochen H.M. Prehn Manus W. Ward 《BBA》2012,1817(5):744-753
The preconditioning response conferred by a mild uncoupling of the mitochondrial membrane potential (Δψm) has been attributed to altered reactive oxygen species (ROS) production and mitochondrial Ca2 + uptake within the cells. Here we have explored if altered cellular energetics in response to a mild mitochondrial uncoupling stimulus may also contribute to the protection. The addition of 100 nM FCCP for 30 min to cerebellar granule neurons (CGNs) induced a transient depolarization of the Δψm, that was sufficient to significantly reduce CGN vulnerability to the excitotoxic stimulus, glutamate. On investigation, the mild mitochondrial ‘uncoupling’ stimulus resulted in a significant increase in the plasma membrane levels of the glucose transporter isoform 3, with a hyperpolarisation of Δψm and increased cellular ATP levels also evident following the washout of FCCP. Furthermore, the phosphorylation state of AMP-activated protein kinase (AMPK) (Thr 172) was increased within 5 min of the uncoupling stimulus and elevated up to 1 h after washout. Significantly, the physiological changes and protection evident after the mild uncoupling stimulus were lost in CGNs when AMPK activity was inhibited. This study identifies an additional mechanism through which protection is mediated upon mild mitochondrial uncoupling: it implicates increased AMPK signalling and an adaptive shift in energy metabolism as mediators of the preconditioning response associated with FCCP-induced mild mitochondrial uncoupling. 相似文献
5.
J. Kelley Bentley Peter W. Reed 《Biochimica et Biophysica Acta (BBA)/General Subjects》1981,678(2):238-244
All of the common cytochalasins activate superoxide anion release and exocytosis of β-N-acetylglucosaminidase and lysozyme from guinea-pig polymorphonuclear leukocytes (neutrophils) incubated in a buffered sucrose medium. Half-maximal activation of both processes is produced by approx. 2 μM cytochalasin A, C >μM cytochalasin B ? 4–5 μM cytochalasin D, E. While maximal rates of O2? release and extents of exocytosis require extracellular calcium (1–2 mM), replacing sucrose with monovalent cation chlorides is inhibitory to neutrophil activation by cytochalasins. Na+, K+ or choline inhibited either cytochalasin B- or E-stimulated O2? production with IC50 values of 5–10 mM and inhibition occurs whether Cl?, NO3? or SCN? is the anion added with Na+ or K+. Release of β-N-acetylglucosaminidase in control or cytochalasin B-stimulated cells is inhibited by NaCl (IC50 ≈ 10 mM), while cytochalasin E-stimulated exocytosis is reduced less and K+ or choline chloride are ineffective in inhibiting either cytochalasin B- or E-stimulated exocytosis. Release of β-glucuronidase, myeloperoxidase or acid phosphatase from neutrophils incubated in buffered sucrose is not stimulated by cytochalasin B. Stimulation of either O2? or β-N-acetylglucosaminidase release by low concentrations of cytochalasin A is followed by inhibition of each at higher concentrations. It appears that all cytochalasins can activate both NAD(P)H oxidase and selective degranulation of neutrophils incubated in salt-restricted media and that differential inhibition of these two processes by monovalent cations and/or anions is produced at some step(s) subsequent to cytochalasin interaction with the cell. 相似文献
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8.
Stefan Schoombie Janine Schoombie Christiaan W. Brink Kim L. Stevens Christopher W. Jones Michelle M. Risi Peter G. Ryan 《Journal of Field Ornithology》2019,90(4):361-372
The use of miniaturized video cameras to study the at‐sea behavior of flying seabirds has increased in recent years. These cameras allow researchers to record several behaviors that were not previously possible to observe. However, video recorders produce large amounts of data and videos can often be time‐consuming to analyze. We present a new technique using open‐source software to extract bank angles from bird‐borne video footage. Bank angle is a key facet of dynamic soaring, which allows albatrosses and petrels to efficiently search vast areas of ocean for food. Miniaturized video cameras were deployed on 28 Wandering Albatrosses (Diomedea exulans) on Marion Island (one of the two Prince Edward Islands) from 2016 to 2018. The OpenCV library for the Python programming language was used to extract the angle of the horizon relative to the bird’s body (= bank angle) from footage when the birds were flying using a series of steps focused on edge detection. The extracted angles were not significantly different from angles measured manually by three independent observers, thus being a valid method to measure bank angles. Image quality, high wind speeds, and sunlight all influenced the accuracy of angle estimates, but post‐processing eliminated most of these errors. Birds flew most often with cross‐winds (58%) and tailwinds (39%), resulting in skewed distributions of bank angles when birds turned into the wind more often. Higher wind speeds resulted in extreme bank angles (maximum observed was 94°). We present a novel method for measuring postural data from seabirds that can be used to describe the fine‐scale movements of the dynamic‐soaring cycle. Birds appeared to alter their bank angle in response to varying wind conditions to counter wind drift associated with the prevailing westerly winds in the Southern Ocean. These data, in combination with fine‐scale positional data, may lead to new insights into dynamic‐soaring flight. 相似文献
9.
10.
Matthew Westover Jared Baxter Rick Baxter Casey Day Ryan Jensen Steve Petersen Randy Larsen 《PloS one》2016,11(5)
Greater sage-grouse populations have decreased steadily since European settlement in western North America. Reduced availability of brood-rearing habitat has been identified as a limiting factor for many populations. We used radio-telemetry to acquire locations of sage-grouse broods from 1998 to 2012 in Strawberry Valley, Utah. Using these locations and remotely-sensed NAIP (National Agricultural Imagery Program) imagery, we 1) determined which characteristics of brood-rearing habitat could be used in widely available, high resolution imagery 2) assessed the spatial extent at which sage-grouse selected brood-rearing habitat, and 3) created a predictive habitat model to identify areas of preferred brood-rearing habitat. We used AIC model selection to evaluate support for a list of variables derived from remotely-sensed imagery. We examined the relationship of these explanatory variables at three spatial extents (45, 200, and 795 meter radii). Our top model included 10 variables (percent shrub, percent grass, percent tree, percent paved road, percent riparian, meters of sage/tree edge, meters of riparian/tree edge, distance to tree, distance to transmission lines, and distance to permanent structures). Variables from each spatial extent were represented in our top model with the majority being associated with the larger (795 meter) spatial extent. When applied to our study area, our top model predicted 75% of naïve brood locations suggesting reasonable success using this method and widely available NAIP imagery. We encourage application of our methodology to other sage-grouse populations and species of conservation concern. 相似文献