2,943 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

    A new species of Conoryctella (Mammalia: Taeniodonta) from the Paleocene of the San Juan Basin, New Mexico, and a revision of the genus

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    Specimens from Paleocene strata of the Nacimiento Formation in Kutz Canyon, San Juan Basin, New Mexico, add to our knowledge of the poorly known taeniodont genus Conoryctella Gazin, 1939 and provide evidence for its taxonomic revision. C. dragonensis Gazin, 1939 is only known with certainty from its type specimen from the Dragon local fauna, North Horn Formation in east-central Utah, although a poorly preserved maxillary fragment and canine of uncertain provenance from the San Juan Basin, New Mexico, may pertain to this taxon. C. pattersoni, new species, differs from C. dragonensis in its smaller size, less molariform P4 and relatively narrow upper molars. It is known from: dental remains from the Dragon local fauna previously referred to C. dragonensis by Gazin (1939, 1941); dental remains from Torrejonian strata in Kutz Canyon referred by Wilson (1956, p. 82) to conoryctine, n. gen. and sp. ; and newly discovered dental and postcranial remains from a horizon in Kutz Canyon that, based on magnetostratigraphy (Tomida and Butler, 1980), is temporally equivalent to the Dragon local fauna. The occurrences of Conoryctella in the San Juan Basin extend the geographic range of the genus and also extend its time-stratigraphic range into a typical Torrejonian horizon. These extensions further reduce the distinctiveness of the Dragon local fauna, supporting recent arguments that the Dragon local fauna should be considered early Torrejonian in age

    A Guide to the Kenya National Archives

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    The Guide is a compilation of 6 sections accessing approximately 157 microfilm reels of documents within the collection of the Kenya National Archives.https://surface.syr.edu/books/1005/thumbnail.jp

    A Guide to the Kenya National Archives to the Microfilms of the Provincial and District Annual Reports, Record Books, and Handing-Over Reports; Miscellaneous Correspondence; and Intelligence Reports

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    The Guide is a compilation of 6 sections accessing approximately 157 microfilm reels of documents within the collection of the Kenya National Archives. Documents in the collection include archival material of the British colonial government in Kenya up to the mid 1960’s. For more information, refer to the Kenya National Archives subject guide.https://surface.syr.edu/archiveguidekenya/1000/thumbnail.jp

    A Guide to the Kenya National Archives to the Microfilms of the Provincial and District Annual Reports, Record Books, and Handing-Over Reports; Miscellaneous Correspondence; and Intelligence Reports

    Get PDF
    The Guide is a compilation of 6 sections accessing approximately 157 microfilm reels of documents within the collection of the Kenya National Archives

    Light exercise heart rate on-kinetics: a comparison of data fitted with sigmoidal and exponential functions and the impact of fitness and exercise intensity

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    This study examined the suitability of sigmoidal (SIG) and exponential (EXP) functions for modeling HR kinetics at the onset of a 5‐min low‐intensity cycling ergometer exercise test (5MT). The effects of training status, absolute and relative workloads, and high versus low workloads on the accuracy and reliability of these functions were also examined. Untrained participants (UTabs; n = 13) performed 5MTs at 100W. One group of trained participants (n = 10) also performed 5MTs at 100W (ETabs). Another group of trained participants (n = 9) performed 5MTs at 45% and 60% max (ET45 and ET60, respectively). SIG and EXP functions were fitted to HR data from 5MTs. A 30‐s lead‐in time was included when fitting SIG functions. Functions were compared using the standard error of the regression (SER), and test‐retest reliability of curve parameters. SER for EXP functions was significantly lower than for SIG functions across all groups. When residuals from the 30‐s lead‐in time were omitted, EXP functions only outperformed SIG functions in ET60 (EXP, 2.7 ± 1.2 beats·min−1; SIG, 3.1 ± 1.1 beats·min−1: P \u3c 0.05). Goodness of fit and test–retest reliability of curve parameters were best in ET60 and comparatively poor in UTabs. Overall, goodness of fit and test–retest reliability of curve parameters favored functions fitted to 5MTs performed by trained participants at a high and relative workload, while functions fitted to data from untrained participants exercising at a low and absolute workload were less accurate and reliable

    Topological generation of simple algebraic groups

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    Let GG be a simple algebraic group over an algebraically closed field and let XX be an irreducible subvariety of GrG^r with r2r \geqslant 2. In this paper, we consider the general problem of determining if there exists a tuple (x1,,xr)X(x_1, \ldots, x_r) \in X such that x1,,xr\langle x_1, \ldots, x_r \rangle is Zariski dense in GG. We are primarily interested in the case where X=C1××CrX = C_1 \times \cdots \times C_r and each CiC_i is a conjugacy class of GG comprising elements of prime order modulo the center of GG. In this setting, our main theorem gives a complete solution to the problem when GG is a symplectic or orthogonal group. By combining our results with earlier work on linear and exceptional groups, this gives a complete solution for all simple algebraic groups. We also present several applications. For example, we use our main theorem to show that many faithful representations of symplectic and orthogonal groups are generically free. We also establish new asymptotic results on the probabilistic generation of finite simple groups by pairs of prime order elements, completing a line of research initiated by Liebeck and Shalev over 25 years ago.Comment: 69 pages; to appear in J. Eur. Math. Soc. (JEMS
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