Showing 1501 - 1510 of 2039 Items
Increasing forest loss worldwide from invasive pests requires new trade regulations
Date: 2014-10-01
Creator: Bitty A. Roy
Helen M. Alexander
Jennifer Davidson
Faith T. Campbell
Jeremy J., Burdon
Richard Sniezko
Clive Brasier
Access: Open access
- Loss of forests due to non-native invasive pests (including insects, nematodes, and pathogens) is a global phenomenon with profound population, community, ecosystem, and economic impacts. We review the magnitude of pest-associated forest loss worldwide and discuss the major ecological and evolutionary causes and consequences of these invasions. After compiling and analyzing a dataset of pest invasions from 21 countries, we show that the number of forest pest invasions recorded for a given country has a significant positive relationship with trade (as indicated by gross domestic product) and is not associated with the amount of forested land within that country. We recommend revisions to existing international protocols for preventing pest entry and proliferation, including prohibiting shipments of non-essential plants and plant products unless quarantined. Because invasions often originate from taxa that are scientifically described only after their introduction, current phytosanitary regulations - which target specific, already named organisms - Are ineffective.
FMRF-NH2-related neuropeptides in Biomphalaria spp., intermediate hosts for schistosomiasis: Precursor organization and immunohistochemical localization
Date: 2021-09-01
Creator: Solymar Rolón-Martínez
Mohamed R. Habib
Tamer A. Mansour
Manuel Díaz-Ríos
Joshua J.C., Rosenthal
Xiao Nong Zhou
Roger P. Croll
Mark W. Miller
Access: Open access
- Freshwater snails of the genus Biomphalaria serve as intermediate hosts for the digenetic trematode Schistosoma mansoni, the etiological agent for the most widespread form of intestinal schistosomiasis. As neuropeptide signaling in host snails can be altered by trematode infection, a neural transcriptomics approach was undertaken to identify peptide precursors in Biomphalaria glabrata, the major intermediate host for S. mansoni in the Western Hemisphere. Three transcripts that encode peptides belonging to the FMRF-NH2-related peptide (FaRP) family were identified in B. glabrata. One transcript encoded a precursor polypeptide (Bgl-FaRP1; 292 amino acids) that included eight copies of the tetrapeptide FMRF-NH2 and single copies of FIRF-NH2, FLRF-NH2, and pQFYRI-NH2. The second transcript encoded a precursor (Bgl-FaRP2; 347 amino acids) that comprised 14 copies of the heptapeptide GDPFLRF-NH2 and 1 copy of SKPYMRF-NH2. The precursor encoded by the third transcript (Bgl-FaRP3; 287 amino acids) recapitulated Bgl-FaRP2 but lacked the full SKPYMRF-NH2 peptide. The three precursors shared a common signal peptide, suggesting a genomic organization described previously in gastropods. Immunohistochemical studies were performed on the nervous systems of B. glabrata and B. alexandrina, a major intermediate host for S. mansoni in Egypt. FMRF-NH2-like immunoreactive (FMRF-NH2-li) neurons were located in regions of the central nervous system associated with reproduction, feeding, and cardiorespiration. Antisera raised against non-FMRF-NH2 peptides present in the tetrapeptide and heptapeptide precursors labeled independent subsets of the FMRF-NH2-li neurons. This study supports the participation of FMRF-NH2-related neuropeptides in the regulation of vital physiological and behavioral systems that are altered by parasitism in Biomphalaria.
Inclusive decays of B mesons to charmonium
Date: 1995-01-01
Creator: R. Balest
K. Cho
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
D. S. Crowcroft
P. S. Drell
D. J. Dumas
R. Ehrlich
P. Gaidarev
M. Garcia-Sciveres
B. Geiser
B. Gittelman
S. W. Gray
D. L. Hartill
B. K. Heltsley
S. Henderson
C. D. Jones
S. L. Jones
J. Kandaswamy
Access: Open access
- We have used the CLEO-II detector at the Cornell Electron Storage Ringe (CESR) to study the inclusive production of charmonium mesons in a sample of 2.15 million BB events. We find inclusive branching fractions of (1.120.040.06)% for BJ/X, (0.340.040.03)% for BX, and (0.400.060.04)% for Bc1X. We also find some evidence for the inclusive production of c2, and set an upper limit for the branching fraction of the inclusive decay BcX of 0.9% at 90% confidence level. Momentum spectra for inclusive J/, and c1 production are presented. These measurements are compared to theoretical calculations. © 1995 The American Physical Society.
Erratum: Context-dependent protein stabilization by methionine-to- leucine substitution shown in T4 lysozyme (Protein Science (November 3, 1998) 7:3 (772))
Date: 1998-01-01
Creator: L. A. Lipscomb
N. C. Gassner
S. D. Snow
A. M. Eldridge
W. A., Baase
D. L. Drew
B. W. Matthews
Access: Open access
Semileptonic branching fractions of charged and neutral B mesons
Date: 1994-01-01
Creator: M. Athanas
W. Brower
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
R. Balest
K. Cho
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
Access: Open access
- An examination of leptons in (4S) events tagged by reconstructed B meson decays yields semileptonic branching fractions of b-=(10.1±1.8±1. 5)% for charged and b0=(10.9±0.7±1.1)% for neutral B mesons. This is the first measurement for charged B mesons. Assuming equality of the charged and neutral semileptonic widths, the ratio b-b0=0.93±0.18±0.12 is equivalent to the ratio of lifetimes. © 1994 The American Physical Society.
Mitochondrial genotype influences the response to cold stress in the European green crab, Carcinus maenas
Date: 2019-01-01
Creator: Aidan F. Coyle
Erin R. Voss
Carolyn K. Tepolt
David B. Carlon
Access: Open access
- Hybrid zones provide natural experiments in recombination within and between genomes that may have strong effects on organismal fitness. On the East Coast of North America, two distinct lineages of the European green crab (Carcinus maenas) have been introduced in the last two centuries. These two lineages with putatively different adaptive properties have hybridized along the coast of the eastern Gulf of Maine, producing new nuclear and mitochondrial combinations that show clinal variation correlated with water temperature. To test the hypothesis that mitochondrial or nuclear genes have effects on thermal tolerance, we first measured the response to cold stress in crabs collected throughout the hybrid zone, then sequenced the mitochondrial CO1 gene and two nuclear single nucleotide polymorphisms (SNPs) representative of nuclear genetic lineage. Mitochondrial haplotype had a strong association with the ability of crabs to right themselves at 4.5°C that was sex specific: haplotypes originally from northern Europe gave male crabs an advantage while there was no haplotype effect on righting in female crabs. By contrast, the two nuclear SNPs that were significant outliers in a comparison between northern and southern C. maenas populations had no effect on righting response at low temperature. These results add C. maenas to the shortlist of ectotherms in which mitochondrial variation has been shown to affect thermal tolerance, and suggest that natural selection is shaping the structure of the hybrid zone across the Gulf of Maine. Our limited genomic sampling does not eliminate the strong possibility that mito-nuclear co-adaptation may play a role in the differences in thermal phenotypes documented here. Linkage between mitochondrial genotype and thermal tolerance suggests a role for local adaptation in promoting the spread of invasive populations of C. maenas around the world.
From Left to Right? White Evangelical Politicization, GOP Incorporation, and the Effect of Party Affiliation on Group Opinion Change
Date: 2013-05-01
Creator: Devon B Shapiro
Access: Open access
- While most white evangelicals in America have advocated moral, cultural, and social conservatism since the Founding, the group’s fiscal and social welfare preferences have been more volatile. Early 20th century evangelicals tended to be socially conservative, fiscally liberal, and, to the extent that they were politicized, mostly Democratic partisans. Since that time, not only have white evangelicals abandoned the Democratic Party, but also they have largely become fiscal and social welfare conservatives. I attempt to explain that transformation. I first examine the dynamics of white evangelical politicization and GOP incorporation, providing social and historical context to the political and partisan calculations of white evangelicals since the 1970s. Further, I propose a party affiliation effect that helps to explain white evangelical fiscal and social welfare conservatism. This effect asserts that partisanship penetrates individual conceptions of political issues. In the case of white evangelicals, I argue that the group affiliated with the GOP largely on the basis of socio-moral issues and concerns. Partly as a result of that affiliation, group opinion on fiscal policy began to drift to the right, toward the Republican Party status quo. Consistent with this claim, I provide longitudinal analyses of ANES and GSS data that shed light on the timing of opinion changes. As we would expect, white evangelical opinion on economic issues was closer to Democratic partisans during the 1960s and moved moved toward Republicans during the 1980s-1990s.
Bodies, Memories, Ghosts, and Objects or Telling a Memory
Date: 2023-01-01
Creator: Natsumi Lynne Meyer
Access: Open access
- I think it started in December 2017, when my Mama sent me to Japan to take care of my grandparents, Baba and Jiji, alone. I had been to Japan almost every year since I was eleven years old, and several times before that too, but this was my first time without Mama. When Mama was there, Japan was filtered through her. I could poke bits of myself through her editing and approval. I could read street signs because of the way she read them, and I could understand my grandparents’ sighs from the timbre of her translation. That December, though, I had to see and hear alone. The tiny shakes in Baba’s legs and the indentation in Jiji’s forehead from when he fell down the stairs crystallized in my memory, and I had to write about it. This project includes a series of creative nonfiction and fiction pieces centered around telling my family stories. Writing from interviews, observations, and generational memories, I weave together these story fragments to discuss Asian American identity and immigration, WWII trauma, aging, and inheritance.
Wall-associated kinases are expressed throughout plant development and are required for cell expansion
Date: 2001-01-01
Creator: T. A. Wagner
B. D. Kohorn
Access: Open access
- The mechanism by which events in the angiosperm cell wall are communicated to the cytoplasm is not well characterized. A family of five Arabidopsis wall-associated kinases (WAKs) have the potential to provide a physical and signaling continuum between the cell wall and the cytoplasm. The WAKs have an active cytoplasmic protein kinase domain, span the plasma membrane, and contain an N terminus that binds the cell wall. We show here that WAKs are expressed at organ junctions, in shoot and root apical meristems, in expanding leaves, and in response to wall disturbances. Leaves expressing an antisense WAK gene have reduced WAK protein levels and exhibit a loss of cell expansion. WAKs are covalently bound to pectin in the cell wall, providing evidence that the binding of a structural carbohydrate by a receptor-like kinase may have significance in the control of cell expansion.
Surface symmetries and PSL2(p)
Date: 2007-05-01
Creator: Murad Özaydin
Charlotte Simmons
Jennifer Taback
Access: Open access
- We classify, up to conjugacy, all orientation-preserving actions of PSL2(p) on closed connected orientable surfaces with spherical quotients. This classification is valid in the topological, PL, smooth, conformal, geometric and algebraic categories and is related to the Inverse Galois Problem. © 2006 American Mathematical Society.