2,923 research outputs found
Restoring Acipenser sturio L., 1758 in Europe: Lessons from the Acipenser oxyrinchus Mitchill, 1815 experience in North America
Acipenser sturio L., 1758 estuvo ampliamente distribuido y fue común en Europa, pero ahora persiste precariamente en estado silvestre sólo en poblaciones relictas. Su especie hermana, el morfológica y ecológicamente similar Acipenser oxyrinchus Mitchill, 1815, existe en el Atlántico norte occidental. Aunque ambas formas han padecido los mismos tres riesgos —sobrepesca, modificación del hábitat y contaminación— sus efectos netos han sido mucho mayores en A. sturio. Históricamente hubo, al menos, 35 poblaciones de A. oxyrinchus en América del Norte; su estado actual varía entre moderadamente abundante a posiblemente extirpado. Sin embargo, el interés por la conservación de A. oxyrinchus ha crecido importantemente durante las dos últimas décadas y se han dado grandes pasos hacia su recuperación. Las técnicas utilizadas han incluido inspecciones de información anecdótica, revisiones directas de las pescas, análisis genético detallado, mejora del cultivo en criadero, sueltas experimentales de juveniles producidos en criadero e investigación básica de la historia natural. Además, la gravedad de los bruscos declives frente a los repentinos aumentos de las pescas reunió la voluntad política para proteger a A. oxyrinchus de la pesca directa en las aguas estadounidenses por un periodo de hasta 40 años (aunque la captura ocasional continúa siendo un problema). Debido a que su tasa intrínseca de crecimiento es muy lenta, tendrán que pasar décadas antes de que poblaciones particulares sean de nuevo abundantes. No obstante, el futuro para A. oxyrinchus parece prometedor. A. sturio es tan escaso que cada ejemplar es precioso; así, es arriesgado experimentar con ellos. Pero dadas las similitudes entre las dos especies, los que pretenden recuperar A. sturio serían capaces de adaptar mucha de la información aprendida de los gestores de A. oxyrinchus.Acipenser sturio L., 1758 was once wide-ranging and common in Europe, but it now persists precariously in the wild only in relict populations. Its sister species, the morphologically and ecologically similar Acipenser oxyrinchus Mitchill, 1815, exists in the western North Atlantic. Although both forms have suffered from the same three liabilities -overharvest, habitat modification, and pollution- their net effects have been far greater for A. sturio. Historically, there were at least 35 populations of A. oxyrinchus in North America; their present statuses range from moderately abundant to possibly extirpated. However, interest in conservation of A. oxyrinchus has increased greatly over the past two decades and great strides have been made toward their restoration. Techniques used have included surveys of anecdotal information, directed fisheries surveys, comprehensive genetic analysis, hatchery culture improvements, experimental stockings of hatcheryproduced young, and fundamental life history research. Moreover, the seriousness of sharp declines in the face of suddenly enlarged fisheries mustered the political will to protect A. oxyrinchus from directed fisheries in U.S. waters for a period of up to 40 years (although by-catch remains a concern). Because their intrinsic rate of increase is very protracted, it will be decades before particular populations are once again abundant. Nonetheless, the future for A. oxyrinchus appears promising. A. sturio is so scarce that each specimen is precious; thus, it is risky to experiment with them. But given the similarities between the two species, those seeking to restore A. sturio should be able to adapt much of the information learned from managers of A. oxyrinchus.Instituto Español de Oceanografí
Instrument to collect fogwater for chemical analysis
An instrument is presented which collects large samples of ambient fogwater by impaction of droplets on a screen. The collection efficiency of the instrument is determined as a function of droplet size, and it is shown that fog droplets in the range 3–100-µm diameter are efficiently collected. No significant evaporation or condensation occurs at any stage of the collection process. Field testing indicates that samples collected are representative of the ambient fogwater. The instrument may easily be automated, and is suitable for use in routine air quality monitoring programs
Managing and Monitoring the Menopausal Body
This Essay explores how menopausal bodies are managed and monitored through both menopausal hormone therapy (MHT) and the burgeoning market for technology-driven menopause products and services. While each of these allegedly improves the menopause experience, a closer investigation reveals a more complex interaction of profit motives and traditional notions of gender identity. The Essay identifies problems with—and suggests some solutions for reforming—current practices of monitoring and managing the menopausal body.
Careful consideration of menopause brings this Essay into ongoing conversations about theorizing beyond the gender binary and stereotypical notions of femininity. Purveyors of both MHT and menopause-related digital products and services appeal to mostly cisgender women by emphasizing ideas of youthfulness, attractiveness, and sexual desirability. We locate these profit seekers within “menopause capitalism,” the marketing and selling of menopause-related products through messages that celebrate autonomy, community, or femininity from entities that are, at their core, commercial enterprises
Managing and Monitoring the Menopausal Body
This Essay explores how menopausal bodies are managed and monitored in contemporary U.S. culture. The focus is on two distinct aspects of that management and monitoring: menopausal hormone therapy (MHT) and the burgeoning market for technology-driven menopause products and services. While each of these allegedly improves the menopause experience, a closer investigation reveals a more complex interaction of profit motives and traditional notions of gender identity. The Essay identifies problems with current medical and business practices and suggests a role for law in destigmatizing menopause, ensuring availability and safety of MHT, and enhancing privacy for users of menopause-oriented apps and digital services
Careful consideration of menopause brings this Essay into ongoing conversations about theorizing beyond the gender binary and stereotypical notions of femininity. Purveyors of both MHT and menopause-related digital products and services appeal to mostly cisgender women by emphasizing ideas of youthfulness, attractiveness, and sexual desirability. We locate these profit seekers within “menopause capitalism,” the marketing and selling of menopause-related products through messages that celebrate autonomy, community, or femininity from entities that are, at their core, commercial enterprises
Contextualizing Menopause in the Law
“It is horrendous, but then it’s magnificent,” says one character about menopause in an episode of the 2019 Netflix comedy Fleabag. Her younger interlocutor is incredulous at this proclamation. That younger character, and even the audience, may be somewhat taken aback by this frank discussion. After all, menopause is not a subject that is commonly discussed, let alone praised. Whether among friends, acquaintances, or colleagues (fictional or not), silence about menopause is more likely the norm. This is true in the law, too. The law mostly ignores menopause.
The law’s silence about menopause is linked to a broader cultural silence about the inevitable consequences of the aging process. It is also linked to longstanding silence and stigma around the menstrual cycle. A growing menstrual advocacy movement, however, has begun to chip away at stigmas and shame surrounding menstruation, in the course of pursuing policy and legal changes that make menstrual products more affordable and available. This Article imagines a role for the law in addressing challenges faced by those transitioning to menopause, whether in the workplace or beyond.
In order to explore how the law should ensure that menopause is not an obstacle to full participation in public life by all people, this Article situates its discussion of menopause in a broader context: the socio-legal treatment of pregnancy, breastfeeding, and menstruation. By viewing the four reproduction-associated conditions or processes together, rather than in silos, it is possible to discern a hierarchy of favorable treatment, with breastfeeding and pregnancy at the top, trailed by menstruation, and with menopause at the bottom. The Article also highlights a connective thread across these processes, which is that the law’s abnormal/normal binary maps uneasily onto each of them.
Ultimately, the Article argues that the law should move beyond individual one-off accommodations for “abnormal” manifestations of these conditions and instead recognize the broad spectrum of what can be considered “normal” experiences. Such an approach challenges the abnormal/normal dichotomy and is necessarily part of a larger scholarly dialogue that challenges binary thinking about gender and disability. By chipping away at the stigma surrounding menopause, this Article seeks for menopause a socio-legal solicitude equal to the one that exists for breastfeeding and pregnancy and that is beginning to emerge for menstruation
The H_2SO_4-HNO_3-NH_3 System at High Humidities and in Fogs: 1. Spatial and Temporal Patterns in the San Joaquin Valley of California
A systematic characterization of the atmospheric H_2SO_4-HNO_3-NH_3 system was conducted in the fog water, the aerosol, and the gas phase at a network of sites in the San Joaquin Valley of California. Spatial patterns of concentrations were established that reflect the distribution of SO_2, NO_x, and NH_3 emissions within the valley. The concept of atmospheric alkalinity was introduced to interpret these concentrations in terms of the buffering capacity of the atmosphere with respect to inputs of strong acids. Regions of predominantly acidic and alkaline fog water were identified. Fog water was found to be alkaline in most of the valley, but small changes in emission budgets could lead to widespread acid fog. An extended stagnation episode was studied in detail: progressive accumulation of H_2SO_4-HNO_3-NH_3 species was documented over the course of the episode and interpreted in terms of production and removal mechanisms. Secondary production of strong acids H_2SO_4 and HNO_3 under stagnant conditions resulted in a complete titration of available alkalinity at the sites farthest from NH_3 sources. A steady SO_2 conversion rate of 0.4–1.1% h^(−1) was estimated in the stagnant mixed layer under overcast conditions and was attributed to nonphotochemical heterogeneous processes. Removal of SO_2 was enhanced in fog, compared to nonfoggy conditions. Conversion of NO_x to HNO_3 slowed down during the stagnation episode because of reduced photochemical activity; fog did not appear to enhance conversion of NO_x. Decreases in total HNO_3 concentrations were observed upon acidification of the atmosphere and were attributed to displacement of NO_3− by H_2SO_4 in the aerosol, followed by rapid deposition of HNO_3(g). The occurrence of fog was associated with general decreases of aerosol concentrations due to enhanced removal by deposition
Fogwater chemistry in an urban atmosphere
Analyses of fogwater collected by inertial impaction in the Los Angeles basin and the San Joaquin Valley indicated unusually high concentrations of major and minor ions. The dominant ions measured were NO_3^−, SO_4^(2−), NH_4^+, and H^+. Nitrate exceeded sulfate on an equivalent basis by a factor of 2.5 in the central and coastal regions of the Los Angeles basin but was approximately equal in the eastern Los Angeles basin and the San Joaquin Valley. Maximum observed values for NH_4^+, NO_3^−, and SO_4^(2−) were 10.0, 12.0, and 5.0, meq 1^(−1), while the lowest p;H observed was 2.2. Iron and lead concentrations of over 0.1 mM and 0.01 mM, respectively, were observed. High concentrations of chemical components in fog appeared to correlate well with the occurrence of smog events. Concentrations in fogwater were also affected by the physical processes of condensation and evaporation. Light, dissipating fogs routinely showed the highest concentrations
The H_2SO_4-HNO_3-NH_3 System at High Humidities and in Fogs: 2. Comparison of Field Data With Thermodynamic Calculations
Concentrations of HNO_3(g) and NH_3(g) determined in the field were compared to predictions from aerosol equilibrium models. The products of HNO_3(g) and NH_3(g) concentrations measured under cool and humid nonfoggy conditions agreed in magnitude with predictions from a comprehensive thermodynamic model for the atmospheric H_2SO_4-HNO_3-NH_3-H_2O system. Observed concentrations of NH_3(g) in fogs were generally consistent with those predicted at equilibrium with fog water, but important discrepancies were noted in some cases. These discrepancies may be due to fluctuations in fog water composition over the course of sample collection or to the sampling of nonfoggy pockets of air present within the fog. Detectable concentrations of HNO_3(g) (up to 23 neq m^(−3)) were often found in fogs with pH 5 were below the detection limit of 4–8 neq m^(−3)
Characterization of Reactants Reaction Mechanisms and Reaction Products Leading to Extreme Acid Rain and Acid Aerosol Conditions in Southern California
Analyses of fogwater collected by inertial impaction in the Los Angeles basin and the San Joaquin Valley indicated unusually high concentrations of major and minor ions. The dominant ions measured were NO_3^-, SO_4^(2-), NH_4^+ and H^+ Nitrate exceeded sulfate on an equivalent basis by a factor of 2.5 in the central and coastal regions of the Los Angeles basin, but was approximately equal in the eastern Los Angeles basin and the San Joaquin Valley. Maximum observed values for NH_4^+, NO_3^- and SO_4^(2-) were 10., 12., and 5. meq L^(-1), while the lowest pH observed was 2.2. Iron and lead concentrations over 0.1 mM and 0.01 mM, respectively, were observed. High concentrations of chemical components in fog appeared to correlate well with the occurrence of smog events. Concentrations in fogwater were also affected by the physical processes of condensation and evaporation. Light, dissipating fogs routinely showed the highest concentrations.
The chemistry of urban fog has been modelled using a hybrid kinetic and equilibrium computer code. Extreme acidity found in Southern California fog may be due either to condensation and growth on acidic condensation nuclei or in situ S(IV) oxidation. Important oxidants of S(IV) were found
to be O_2 as catalyzed by Fe(III) and Mn(II), H_2)_2 and 0_3. formation of hydroxymethane sulfonate ion (HMSA) via the nucleophilic addition of HSO_3^-to CH_2 CH_2O(ℓ) significantly increased the droplet capacity for S(IV) but did not slow down the net S(IV) oxidation rate leading to fog acidification. Gas phase nitric acid, ammonia and hydrogen peroxide were scavenged efficiently, although aqueous phase hydrogen peroxide was depleted rapidly by reduction with S(IV). Nitrate production in the aqueous phase was found to be dominated by HNO_3 gas phase scavenging. Major aqueous-phase species concentrations were controlled primarily by condensation, evaporation, and pH
- …