Showing 3421 - 3430 of 5713 Items
Investigating the Role of Heterochromatin Protein 1 (HP1) in the Formation of Chromosome Compartments Access to this record is restricted to members of the Bowdoin community. Log in here to view.
- Restriction End Date: 2025-06-01
Date: 2020-01-01
Creator: Diego Andres Villamarin
Access: Access restricted to the Bowdoin Community
Effects of stochasticity on the length and behaviour of ecological transients
Date: 2021-07-01
Creator: Alan Hastings, Karen C. Abbott, Kim Cuddington, Tessa B. Francis, Ying Cheng, Lai, Andrew Morozov
Access: Open access
- There is a growing recognition that ecological systems can spend extended periods of time far away from an asymptotic state, and that ecological understanding will therefore require a deeper appreciation for how long ecological transients arise. Recent work has defined classes of deterministic mechanisms that can lead to long transients. Given the ubiquity of stochasticity in ecological systems, a similar systematic treatment of transients that includes the influence of stochasticity is important. Stochasticity can of course promote the appearance of transient dynamics by preventing systems from settling permanently near their asymptotic state, but stochasticity also interacts with deterministic features to create qualitatively new dynamics. As such, stochasticity may shorten, extend or fundamentally change a system's transient dynamics. Here, we describe a general framework that is developing for understanding the range of possible outcomes when random processes impact the dynamics of ecological systems over realistic time scales. We emphasize that we can understand the ways in which stochasticity can either extend or reduce the lifetime of transients by studying the interactions between the stochastic and deterministic processes present, and we summarize both the current state of knowledge and avenues for future advances.
Species identification based on a semi-diagnostic marker: Evaluation of a simple conchological test for distinguishing blue mussels Mytilus edulis L. And M. trossulus Gould
Date: 2021-07-01
Creator: Vadim Khaitov, Julia Marchenko, Marina Katolikova, Risto Väinölä, Sarah E., Kingston, David B. Carlon, Michael Gantsevich, Petr Strelkov
Access: Open access
- Cryptic and hybridizing species may lack diagnostic taxonomic characters leaving researchers with semi-diagnostic ones. Identification based on such characters is probabilistic, the probability of correct identification depending on the species composition in a mixed population. Here we test the possibilities of applying a semi-diagnostic conchological character for distinguishing two cryptic species of blue mussels, Mytilus edulis and M. trossulus. These ecologically, stratigraphically and economically important molluscs co-occur and hybridize in many areas of the North Atlantic and the neighboring Arctic. Any cues for distinguishing them in sympatry without genotyping would save much research effort. Recently these species have been shown to statistically differ in the White Sea, where a simple character of the shell was used to distinguish two mussel morphotypes. In this paper, we analyzed the associations between morphotypes and species-specific genotypes based on an abundant material from the waters of the Kola Peninsula (White Sea, Barents Sea) and a more limited material from Norway, the Baltic Sea, Scotland and the Gulf of Maine. The performance of the “morphotype test” for species identification was formally evaluated using approaches from evidence-based medicine. Interspecific differences in the morphotype frequencies were ubiquitous and unidirectional, but their scale varied geographically (from 75% in the White Sea to 15% in the Baltic Sea). In addition, salinity-related variation of this character within M. edulis was revealed in the Arctic Barents Sea. For every studied region, we established relationships between the proportions of the morphotypes in the populations as well as between the proportions of the morphotypes in samples and the probabilities of mussels of different morphotypes being M. trossulus and M. edulis. We provide recommendations for the application of the morphotype test to mussels from unstudied contact zones and note that they may apply equally well to other taxa identified by semi-diagnostic traits.
Bowdoin College - Medical School of Maine Catalogue (1908-1909)
Date: 1909-01-01
Access: Open access
- Bowdoin College Bulletin no. 19
Bowdoin College Catalogue (1915-1916)
Date: 1916-01-01
Access: Open access
- Bowdoin College Bulletin no. 62
Atmospheric measurements of the terrestrial O2 : CO2 exchange ratio of a midlatitude forest
Date: 2019-07-10
Creator: Mark O. Battle, J. William Munger, Margaret Conley, Eric Sofen, Rebecca, Perry, Ryan Hart, Zane Davis, Jacob Scheckman, Jayme Woogerd, Karina Graeter, Samuel Seekins, Sasha David, John Carpenter
Access: Open access
- Measurements of atmospheric O2 have been used to quantify large-scale fluxes of carbon between the oceans, atmosphere and land since 1992 (Keeling and Shertz, 1992). With time, datasets have grown and estimates of fluxes have become more precise, but a key uncertainty in these calculations is the exchange ratio of O2 and CO2 associated with the net land carbon sink (B). We present measurements of atmospheric O2 and CO2 collected over a 6-year period from a mixed deciduous forest in central Massachusetts, USA (42.537 N, 72.171 W). Using a differential fuel-cellbased instrument for O2 and a nondispersive infrared analyzer for CO2, we analyzed airstreams collected within and 5m above the forest canopy. Averaged over the entire period of record, we find these two species covary with a slope of -1:081±0:007 mol of O2 per mole of CO2 (the mean and standard error of 6 h periods). If we limit the data to values collected on summer days within the canopy, the slope is -1:03±0:01. These are the conditions in which biotic influences are most likely to dominate. This result is significantly different from the value of -1.1 widely used in O2-based calculations of the global carbon budget, suggesting the need for a deeper understanding of the exchange ratios of the various fluxes and pools comprising the net sink.
Inclusive decay B→ηX
Date: 1996-01-01
Creator: Y. Kubota, M. Lattery, M. Momayezi, J. K. Nelson, S., Patton, R. Poling, V. Savinov, S. Schrenk, R. Wang, M. S. Alam, I. J. Kim, Z. Ling, A. H. Mahmood, J. J. O’Neill, H. Severini, C. R. Sun, F. Wappler, G. Crawford, C. M. Daubenmier, R. Fulton, D. Fujino, K. K. Gan, K. Honscheid, H. Kagan, R. Kass, J. Lee, M. Sung, C. White, A. Wolf, M. M. Zoeller, F. Butler
Access: Open access
- Using data samples taken at the Υ(4S) resonance and nearby continuum e+e- annihilation with the CLEO-II detector at CESR, we have measured the inclusive branching fraction B(B→ηX)=(17.6±1.1±1.2)%, and the momentum distribution of the η mesons from B meson decay. The η yield cannot be explained as arising solely from the decay of intermediate charmed mesons. © 1996 The American Physical Society.
Exclusive hadronic B decays to charm and charmonium final states
Date: 1994-01-01
Creator: M. S. Alam, I. J. Kim, B. Nemati, J. J. ONeill, H., Severini, C. R. Sun, M. M. Zoeller, G. Crawford, C. M. Daubenmier, R. Fulton, D. Fujino, K. K. Gan, K. Honscheid, H. Kagan, R. Kass, J. Lee, R. Malchow, F. Morrow, Y. Skovpen, M. Sung, C. White, F. Butler, X. Fu, G. Kalbfleisch, W. R. Ross, P. Skubic, J. Snow, P. L. Wang, M. Wood, D. N. Brown, J. Fast
Access: Open access
- We have fully reconstructed decays of both B»0 and B- mesons into final states containing either D, D*, D**, , or c1 mesons. This allows us to obtain new results on many physics topics including branching ratios, tests of the factorization hypothesis, color suppression, resonant substructure, and the B - B»0 mass difference. © 1994 The American Physical Society.