Showing 1271 - 1280 of 3000 Items
Position effects influence transvection in drosophila melanogaster
Date: 2019-01-01
Creator: Thomas D. King
Justine E. Johnson
Jack R. Bateman
Access: Open access
- Transvection is an epigenetic phenomenon wherein regulatory elements communicate between different chromosomes in trans, and is thereby dependent upon the three-dimensional organization of the genome. Transvection is best understood in Drosophila, where homologous chromosomes are closely paired in most somatic nuclei, although similar phenomena have been observed in other species. Previous data have supported that the Drosophila genome is generally permissive to enhancer action in trans, a form of transvection where an enhancer on one homolog activates gene expression from a promoter on a paired homolog. However, the capacity of different genomic positions to influence the quantitative output of transvection has yet to be addressed. To investigate this question, we employed a transgenic system that assesses and compares enhancer action in cis and in trans at defined chromosomal locations. Using the strong synthetic eye-specific enhancer GMR, we show that loci supporting strong cis-expression tend to support robust enhancer action in trans, whereas locations with weaker cis-expression show reduced transvection in a fluorescent reporter assay. Our subsequent analysis is consistent with a model wherein the chromatin state of the transgenic insertion site is a primary determinant of the degree to which enhancer action in trans will be supported, whereas other factors such as locus-specific variation in somatic homolog pairing are of less importance in influencing position effects on transvection.
Exploring film language with a digital analysis tool: The case of kinolab
Date: 2021-01-01
Creator: Allison Cooper
Fernando Nascimento
David Francis
Access: Open access
- This article presents a case study of Kinolab, a digital platform for the analysis of narrative film language. It describes the need for a scholarly database of clips focusing on film language for cinema and media studies faculty and students, highlighting recent technological and legal advances that have created a favorable environment for this kind of digital humanities work. Discussion of the project is situated within the broader context of contemporary developments in moving image annotation and a discussion of the unique challenges posed by computationally-driven moving image analysis. The article also argues for a universally accepted data model for film language to facilitate the academic crowdsourcing of film clips and the sharing of research and resources across the Semantic Web.
Estimating the impact of Critical Habitat designation on the values of developed and undeveloped parcels (2nd version, current as of 7/29/2022)
Date: 2022-07-29
Creator: Saleh Mamun
Erik Nelson
Christoph Nolte
Access: Open access
- We use differences-in-differences (DD) estimators to measure the impact that Endangered Species Act (ESA)’s Critical Habitat (CH) rule had on developed and undeveloped parcel prices throughout the US between 2000 and 2019. In a national-level analysis we found that, on average, the price of parcels “treated” with CH were not statistically different than the prices of nearby parcels in listed species range space but not “treated” by CH. CH’s null impact on developed parcel prices is surprising given homeowner’s documented willingness to pay for property surrounded by protected open space. CH’s null impact on undeveloped parcel prices is surprising as previous research had indicated that the impact of CH on undeveloped parcel prices was negative due to the additional regulatory costs and development uncertainty the CH regulation imposes on land developers. When we used relevant subsets of CH areas to measure CH’s impact on parcel prices, we did occasionally find results that were consistent with expectations. We reach two conclusions. First, the impact of the economic impact of the CH rule, holding the impact of other ESA sections constant, cannot be reduced to a simple, consistent narrative. Second, CH’s relatively minor impact on parcel prices suggests that the rule does not have much regulatory “bite.”
Survey on Italian Studies & Digital Humanities
Date: 2016-08-18
Creator: Crystal Hall
Access: Open access
- A survey distributed in English and Italian to collect information about the intersection of the fields of Italian Studies and Digital Humanities. The goals are to describe the kinds of work being done by scholars in this space of intersection, identify successful professional pathways that combine methods or content from the two fields, and inform next steps for organizations that support this work. Results will be discussed at the Wellesley "State of the Discipline" event on October 1, 2016 and the MLA Roundtable on the topic, January 5, 2017. The survey is provided here in case other fields are interested in conducting similar work.
Fast pyrolysis of lignins
Date: 2010-08-01
Creator: Sedat H. Beis
Saikrishna Mukkamala
Nathan Hill
Jincy Joseph
Cirila, Baker
Bruce Jensen
Elizabeth A. Stemmler
M. Clayton Wheeler
Brian G. Frederick
Access: Open access
- Three lignins: Indulin AT, Lignoboost™, and Acetocell lignin, were characterized and pyrolyzed in a continuous-fed fast pyrolysis process. The physical and chemical properties of the lignins included chemical composition, heat content, ash, and water content. The distributed activation energy model (DAEM) was used to describe the pyrolysis of each lignin. Activation energy distributions of each lignin were quite different and generally covered a broad range of energies, typically found in lignins. Process yields for initial continuous-fed fast pyrolysis experiments are reported. Bio-oil yield was low, ranging from 16 to 22%. Under the fast pyrolysis conditions used, the Indulin AT and Lignoboost™ lignin yielded slightly more liquid product than the Acetocell lignin. Lignin kinetic parameters and chemical composition vary considerably and fast pyrolysis processes must be specified for each type of lignin.
Why we write (nuclear) history
Date: 2017-09-01
Creator: David K. Hecht
Access: Open access
- Nuclear history always compels. Scholars (and readers) can immerse themselves in the existential threat posed by the atomic bomb and its successor weapons, the tantalizing prospect of carbon-free energy, or the study of a natural phenomenon deeply at odds with our everyday experience of the world. There is thus always something profound at stake when we write nuclear historyÂ-Â be it physical, economic or intellectual. And while it may seem that the end of the Cold War should have diminished the academic attention accorded to the subject, it actually just allowed the historiography to evolve. To the wealth of technical and political studies that once dominated nuclear history, we can now add a host of excellent cultural, environmental, literary and transnational studies. Those of us who entered the field shortly after the break-up of the Soviet Union have been able to follow these developments first-hand, from the initial uncertainty of where nuclear history would go without its original raison d'être to seeing the possibilities opened up in a post-Cold War world. The books under review here provide important and timely additions to this historiography. Luis A. Campos's Radium and the Secret Life provides a rigorous and compelling account of the uses of radium in early twentieth-century biology; Timothy J. Jorgensen's Strange Glow: The Story of Radiation offers an accessible and illuminating analysis of the benefits and risks of radiation. The books also make for a fascinating juxtaposition. They complement each other well, but also contain some intriguing differences that allow us to reflect on the nature of nuclear history in the early twenty-first century.
Sexual reproduction is more prevalent in continental landscapes in the expanding arctic shrub, Salix glauca
Date: 2019-12-01
Creator: David A. Watts
Vladimir Douhovnikoff
Eric Post
Access: Open access
- The recent expansion of arctic deciduous shrubs has been well documented across a range of habitats, but the phenomenon is not universal. Their spread is often associated with increases in temperature and other abiotic factors, while variation in habitat moisture and herbivory can mediate the location and rate of this rise in abundance. Much less is known about the mode of increase of arctic shrubs. For one such shrub, Salix glauca, we used microsatellite markers to assess the prevalence of clonal growth (i.e. vegetative spread) and sexual reproduction (i.e. recruitment from seed) at sites with maritime and continental climates and differing in the density of large herbivores. We sampled individuals in plots reflecting the spatial scale of expansion in locations where S. glauca recently increased in abundance. The 400 samples collected across the four sites comprised 310 genotypes. Though evidence of sexual recruitment was common across all sites, coastal sites contained both more and larger clonal genotypes. While we expected soil conditions would be influential, the factors that best predicted the likelihood of clonality, genet size and vascular plant cover, suggest the light environment is of primary importance. Furthermore, in spite of the large distances between sites, there was no suggestion of genetic differentiation into distinct populations. These results indicate that differences in climate and herbivory can influence not only where and how extensively deciduous shrubs spread, but how they are likely to do so. We suggest future research integrating how mode of increase is associated with the rate of spread will advance projections of change in arctic ecosystems.
Environmental issues in russia
Date: 2008-12-01
Creator: Laura A. Henry
Vladimir Douhovnikoff
Access: Open access
- This review examines the literature available on the state of the environment and environmental protection in the Russian Federation. As the largest country on Earth, rich in natural resources and biodiversity, Russia's problems and policies have global consequences. Environmental quality and management are influenced by the legacy of Soviet economic planning and authoritarian governance, as well as by Russia's post-Soviet economic recession and current strategies of economic development. Russia achieved a reduction in some pollutants owing to the collapse of industrial production in the 1990s, but many environmental indicators suggest growing degradation. Russia has signed on to a number of international environmental agreements, but its record on implementation is mixed, and it discourages environmental activism. Scholarship on the Russian environment is a limited, but growing, field, constrained by challenges of data availability, yet it offers great potential for testing scientific and social scientific hypotheses. ©2008 by Annual Reviews.
Study of the five-charged-pion decay of the τ lepton
Date: 1994-01-01
Creator: D. Gibaut
K. Kinoshita
B. Barish
M. Chadha
S., Chan
D. F. Cowen
G. Eigen
J. S. Miller
C. O'Grady
J. Urheim
A. J. Weinstein
D. Acosta
M. Athanas
G. Masek
H. P. Paar
J. Gronberg
R. Kutschke
S. Menary
R. J. Morrison
S. Nakanishi
H. N. Nelson
T. K. Nelson
C. Qiao
J. D. Richman
A. Ryd
H. Tajima
D. Sperka
M. S. Witherell
M. Procario
R. Balest
K. Cho
Access: Open access
- The branching fractions for the five-charged-particle decays of the τ lepton have been measured in e+e- annihilations using the CLEO II detector at the Cornell Electron Storage Ring. Assuming all charged particles to be pions, the results are B(3π-2π+0 neutrals ντ)=(0.097±0. 005±0.011)%, B(3π-2π+ντ)=(0.077±0.005 ±0.009)%, B(3π-2π+π0ντ)=(0.019±0.004±0.004) %, and B(3π-2π+2π0ντ)<0.011% at the 90% C.L. B(3π-2π-π0ντ) is measured for the first time by exclusive π0 reconstruction. The results are compared with the predictions from the partially conserved-axial-current and conserved-vector-current hypotheses assuming isospin invariance. © 1994 The American Physical Society.
Observation of inclusive B decays to the charmed baryons c++ and c0
Date: 1994-01-01
Creator: M. Procario
R. Balest
K. Cho
M. Daoudi
W. T., Ford
D. R. Johnson
K. Lingel
M. Lohner
P. Rankin
J. G. Smith
J. P. Alexander
C. Bebek
K. Berkelman
K. Bloom
T. E. Browder
D. G. Cassel
H. A. Cho
D. M. Coffman
P. S. Drell
R. Ehrlich
R. S. Galik
M. Garcia-Sciveres
B. Geiser
B. Gittelman
S. W. Gray
D. L. Hartill
B. K. Heltsley
C. D. Jones
S. L. Jones
J. Kandaswamy
N. Katayama
Access: Open access
- Using data collected in the region of the γ(4S) resonance with the CLEO II detector operating at the Cornell Electron Storage Ring, we report on evidence for the production of ++ and c0 baryons in B decays, with c→Λc+π. This observation is based on 77±19 c++ and 76±21 c0 candidates from B decays. We find the product branching fractions B(B̄→cX)B(Λc+→pK-π+) for c=c++, c0, and c+ to be (2.1 ± 0.8 ± 0.7) × 10-4, (2.3 ± 0.8 ± 0.7) × 10-4, and less than 4.8 × 10-4 at 90% confidence level, respectively. A study of the c++ and c0 momentum spectra indicates that B decays to two-body final states with c are suppressed. © 1994 The American Physical Society.