3,350 research outputs found

    Coordination and Sustainability of River Observing Activities in the Arctic

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    To understand and respond to changes in the world’s northern regions, we need a coordinated system of long-term Arctic observations. River networks naturally integrate across landscapes and link the terrestrial and ocean domains. Changes in river discharge reflect changes in the terrestrial water balance, whereas changes in water chemistry are linked to changes in biogeochemical processes and water flow paths. Sustained measurements of river water discharge and water chemistry are therefore essential components of an Arctic observing network. As we strive to establish and sustain long-term observations in the Arctic, these two measurements must be coupled. Although river discharge and chemistry measurements are already coupled to some extent within national boundaries, this is not done in a consistent and coordinated fashion across the pan-Arctic domain. As a consequence, data quality and availability vary widely among regions. International coordination of river discharge and chemistry measurements in the Arctic would be greatly facilitated by formal commitments to maintain a set of core sites and associated measurements that are mutually agreed upon among pan-Arctic nations. Involvement of the agencies currently operating river discharge gauges around the Arctic and establishment of an overarching coordination entity to implement shared protocols, track data quality, and manage data streams would be essential in this endeavor. Focused studies addressing scale-dependent relationships between watershed characteristics and water chemistry, in-stream processes, and estuarine and coastal dynamics are also needed to support interpretation and application of Arctic river observing data as they relate to land and ocean change

    River Discharge: In State of the Climate in 2015.

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    River Discharge

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    In 2014, combined discharge from the eight largest Arctic rivers (2,487 km3) was 10% greater than average discharge for the period 1980-1989. Values for 2013 (2,282 km3) and 2012 (2,240 km3) were 1% greater than and 1% less than the 1980-1989 average, respectively. For the first seven months of 2015, the combined discharge for the six largest Eurasian Arctic rivers shows that peak discharge was 10% greater and five days earlier than the 1980-1989 average for those months

    ANTIBODY RESPONSE TO HOMOGRAFTS : VIII. RELATION OF MOUSE HEMAGGLUTININS AND CYTOTOXINS

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    Antigenic differences between certain inbred strains of mice which could not be revealed by hemagglutination techniques were readily disclosed by lymphocyte cytotoxicity. With an improved cytotoxicity test lymphotoxic titers were as high as 1:512 with non-hemagglutinating A anti CBA antisera. In other mouse strain combinations, a close parallel of both types of antibody activity was obtained. Though both activities were absorbed from antisera proportionally by erythrocytes and lymph node cells, 100 to 1000 times as many erythrocytes as lymphocytes were necessary to produce an equivalent reduction in antibody activity. These findings suggest that erythrocytes may possess only subthreshold quantities of certain antigens which are present in readily detectable levels on lymphocytes. Lymphocyte cytotoxicity therefore may assay a wider range of allogenic antigens than hemagglutination

    In the Fabric of Research: Racial and Gender Stereotypes in Survey Items Assessing Attitudes about Abortion

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    We investigated the content of survey items to assess whether and how racist and sexist stereotypes are woven into the fabric of research on attitudes about abortion in the United States. We collected and analyzed a comprehensive set of survey items (456 items from 80 studies) used in peer‐reviewed research published from 2008 to 2018 in representative and nonrepresentative studies of U.S. respondents. Our analysis was guided by historical narratives that have been influential in shaping representations of women and reproduction in the United States (e.g., the Moynihan Report). With this background, we developed three themes pertaining to how individuals’ attitudes about abortion are measured: we found that items rely on (1) moral, (2) sexual, and (3) financial evaluations of women seeking abortion care. These themes highlighted implicit and explicit judgments of women, including representations of them as unwilling to partner with men and as fiscally and sexually irresponsible. We argue that survey items meant to objectively assess abortion attitudes draw on negative racial and gender stereotypes and that these stereotypes then travel widely under the veneer of scientific objectivity. Critical methods, such as the item bank analysis described in this study, are crucial to discern how inequality, prejudice, and discrimination can be reproduced in the fabric of research methods. In our discussion, we offer suggestions for researchers to reduce these and related forms of bias in survey‐based abortion research.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155945/1/josi12367_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155945/2/josi12367.pd

    Intensity-noise properties of injection-locked lasers

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    We present experimental results that illustrate how laser intensity noise near the quantum-noise limit is transferred in an injection-locked cw Nd:(yttrium aluminum garnet) nonplanar ring-oscillator laser. We show that these results are in extremely good agreement with our quantum-mechanical model describing the injection locking process [T. C. Ralph, C. C. Harb, and H.-A. Bachor, Phys. Rev. A]. Three regions in the intensity-noise spectrum are identified and we show that different minimum noise levels exist in these regions. Finally, we show that the injection-locked laser can generate and preserve nonclassical states

    Coordination and Sustainability of River Observing Activities in the Arctic

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    To understand and respond to changes in the world’s northern regions, we need a coordinated system of long-term Arctic observations. River networks naturally integrate across landscapes and link the terrestrial and ocean domains. Changes in river discharge reflect changes in the terrestrial water balance, whereas changes in water chemistry are linked to changes in biogeochemical processes and water flow paths. Sustained measurements of river water discharge and water chemistry are therefore essential components of an Arctic observing network. As we strive to establish and sustain long-term observations in the Arctic, these two measurements must be coupled. Although river discharge and chemistry measurements are already coupled to some extent within national boundaries, this is not done in a consistent and coordinated fashion across the pan-Arctic domain. As a consequence, data quality and availability vary widely among regions. International coordination of river discharge and chemistry measurements in the Arctic would be greatly facilitated by formal commitments to maintain a set of core sites and associated measurements that are mutually agreed upon among pan-Arctic nations. Involvement of the agencies currently operating river discharge gauges around the Arctic and establishment of an overarching coordination entity to implement shared protocols, track data quality, and manage data streams would be essential in this endeavor. Focused studies addressing scale-dependent relationships between watershed characteristics and water chemistry, in-stream processes, and estuarine and coastal dynamics are also needed to support interpretation and application of Arctic river observing data as they relate to land and ocean change.Pour comprendre les changements qui s’opĂšrent dans les rĂ©gions nordiques du monde et y rĂ©agir, nous devons nous doter d’un systĂšme coordonnĂ© d’observation Ă  long terme dans l’Arctique. Les rĂ©seaux fluviaux s’intĂšgrent naturellement dans les paysages et relient le domaine terrestre au domaine ocĂ©anique. Les changements qui s’exercent dans les rĂ©seaux fluviaux sont le reflet des changements dans l’équilibre hydrique terrestre, tandis que les changements qui s’exercent sur l’hydrochimie sont liĂ©s aux changements caractĂ©risant les processus biogĂ©ochimiques et les parcours d’écoulement de l’eau. Par consĂ©quent, un rĂ©seau d’observation arctique devrait essentiellement ĂȘtre assorti de mesures durables d’évacuation des eaux fluviales et d’hydrochimie. Au moment oĂč nous nous efforçons d’établir et de soutenir des observations Ă  long terme dans l’Arctique, ces deux types de mesures doivent ĂȘtre suivies en parallĂšle. Bien que les mesures de l’évacuation fluviale et les mesures chimiques soient dĂ©jĂ , dans une certaine mesure, suivies en parallĂšle Ă  l’intĂ©rieur des frontiĂšres nationales, cela ne se fait pas de maniĂšre uniforme et coordonnĂ©e Ă  la grandeur du domaine panarctique, et en consĂ©quence, la qualitĂ© et la disponi­bilitĂ© des donnĂ©es varient beaucoup d’une rĂ©gion Ă  l’autre. La coordination internationale des mesures d’évacuation fluviale et chimiques dans l’Arctique serait grandement facilitĂ©e par l’existence d’engagements officiels visant Ă  maintenir une sĂ©rie d’emplacements fondamentaux et de mesures connexes fixĂ©es par entente mutuelle au sein des nations panarctiques. La partic­ipation des agences qui gĂšrent les manomĂštres d’évacuation fluviale dans l’Arctique et l’établissement d’une entitĂ© de coordi­nation gĂ©nĂ©rale mettant en oeuvre des protocoles partagĂ©s, vĂ©rifiant la qualitĂ© des donnĂ©es et gĂ©rant les flux de donnĂ©es seraient Ă©galement essentiels. Des Ă©tudes ciblĂ©es portant sur les relations influencĂ©es par l’échelle entre les caractĂ©ristiques du bassin hydrographique et l’hydrochimie, sur les processus s’opĂ©rant Ă  l’intĂ©rieur des cours d’eau et sur la dynamique des estuaires et des rives s’avĂšrent Ă©galement nĂ©cessaires pour Ă©tayer l’interprĂ©tation et l’application des donnĂ©es d’observation fluviale de l’Arctique en matiĂšre de changement terrestre et ocĂ©anique

    Pico-strain multiplexed fiber optic sensor array operating down to infra-sonic frequencies

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    An integrated sensor system is presented which displays passive long range operation to 100 km at pico-strain (pΔ) sensitivity to low frequencies (4 Hz) in wavelength division multiplexed operation with negligible cross-talk (better than −75 dB). This has been achieved by prestabilizing and multiplexing all interrogation lasers for the sensor array to a single optical frequency reference. This single frequency reference allows each laser to be locked to an arbitrary wavelength and independently tuned, while maintaining suppression of laser frequency noise. With appropriate packaging, such a multiplexed strain sensing system can form the core of a low frequency accelerometer or hydrophone array

    The Politics of Teen Women’s Sexuality: Public Policy and the Adolescent Female Body

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    Teen women\u27s sexual and reproductive lives are shaped by laws and public policies that expand or constrict their educational and health supports. Most adolescents depend substantially on the public sector to help support their healthy sexual development and to protect them from sexual violence, disease, and pregnancy. Thus, it is critical to examine the ways in which public policies concerning young women\u27s sexualities have been forged within religious and moralizing discourses. The explicit pairing of law and religious ideology has transformed the role of law and public policy in young women\u27s lives from a supportive function to one that censures young women for their sexual behavior. As educational, social service, and health supports for youth are scaled back in the name of small government or neoliberal reform, the adverse consequences of sexual behavior are described as if they are natural. As a consequence, the etiology of these consequences is erased. Young women, especially young women of color and poor women, end up shouldering a heavy burden for engaging in sexual activity—activity that they engaged in by choice or by coercion
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