Showing 601 - 650 of 733 Items

Date: 2012-09-01

Creator: Laura A. Henry

Access: Open access

Prior to December 2011, instances of widespread collective mobilization were relatively rare in contemporary Russia. Russian citizens are more likely to engage in a different means of airing grievances: making an official complaint to the authorities. This article considers how complaint-making, as a variety of political participation, may contribute either to authoritarian resilience or to political liberalization. The political significance of complaints made to the Commissioner for Human Rights of the Russian Federation is examined. Since it is the broader political context that shapes the significance of complaints, in the absence of meaningful elections individualized appeals to the state are unlikely to promote democratic change, although they may allow for redress of individual rights violations. © 2012 The Regents of the University of California.

Date: 2015-03-17

Creator: E. Kim, F. Li, C. Chong, G. Theocharis, J., Yang, P. G. Kevrekidis

Access: Open access

In the present work, we experimentally implement, numerically compute with, and theoretically analyze a configuration in the form of a single column woodpile periodic structure. Our main finding is that a Hertzian, locally resonant, woodpile lattice offers a test bed for the formation of genuinely traveling waves composed of a strongly localized solitary wave on top of a small amplitude oscillatory tail. This type of wave, called a nanopteron, is not only motivated theoretically and numerically, but is also visualized experimentally by means of a laser Doppler vibrometer. This system can also be useful for manipulating stress waves at will, for example, to achieve strong attenuation and modulation of high-amplitude impacts without relying on damping in the system.

Date: 2014-11-26

Creator: Amitai Abramovitch, Hannah Reese, Douglas W. Woods, Alan Peterson, Thilo, Deckersbach, John Piacentini, Lawrence Scahill, Sabine Wilhelm

Access: Open access

The gold-standard measure of tic severity in tic disorders (TD), the Yale Global Tic Severity Scale (YGTSS), is a semistructured clinician-administered interview that can be time consuming and requires highly trained interviewers. Moreover, the YGTSS does not provide information regarding frequency and intensity of specific tics because all motor and all vocal tics are rated as a group. The aim of the present study is to describe and test the Adult Tic Questionnaire (ATQ), a measure for the assessment of tic severity in adults, and to report its preliminary psychometric properties. The ATQ is a brief self-report questionnaire that provides information regarding frequency, intensity, and severity of 27 specific tics. In addition, the ATQ produces total frequency, intensity, and severity scores for vocal and motor tics, as well as a global total tic severity score. Results showed that the ATQ demonstrated very good internal consistency and temporal stability. The total, vocal, and motor tic severity scales of the ATQ showed strong correlation with corresponding subscales of the YGTSS, indicating strong convergent validity. Weak correlations with measures of severity of obsessive-compulsive disorder and attention deficit/hyperactivity disorder, indicated strong discriminant validity. The ATQ, a promising measure for the assessment of tic severity in adults with TD, may be a valuable supplement to the current recommended assessment battery for TD. Furthermore, the ATQ enables clinicians and researchers to track changes in the frequency and intensity of specific tics, which is important given their complex and dynamic nature.

Date: 1996-11-20

Creator: Michael F. Palopoli, Andrew W. Davis, Chung I. Wu

Access: Open access

According to measures of molecular divergence, the three species of the Drosophila simulans clade are closely related to and essentially equidistant from each other. We introgressed 10% of the D. sechellia X chromosome into a pure D. simulans genetic background and found that males carrying this introgressed region were consistently fertile; in contrast, males carrying the same segment from D. mauritiana are sterile and suffer from incompatibilities at a minimum of four loci. Together with other recent results, these data suggest that D. simulans and D. sechellia are much more closely related to each other than either is to D. mauritiana. How can we reconcile the phylogeny inferred from the density of hybrid sterility genes with that inferred from molecular divergence? If the molecular phylogeny is correct, the discrepancy might be explained by uneven rates of functional evolution, resulting in the uneven accumulation of substitutions with corresponding negative effects in hybrids. If the functional phylogeny is correct, then low levels of gene flow across nascent species boundaries, particularly for loci not tightly linked to a hybrid sterility gene, may have erased the original pattern of lineage splitting. We propose tests that will allow us to discriminate between the hypotheses.

Date: 2021-08-01

Creator: Lea Takács, Samuel P. Putnam, František Bartoš, Pavel Cepický, Catherine, Monk

Access: Open access

Objective Cesarean section (CS) rates are rising rapidly around the world but no conclusive evidence has been obtained about the possible short- and long-term effects of CS on child behavior. We evaluated prospectively the association between CS and infant temperament across the first 9 postpartum months, controlling for indications for CS and investigating parity and infant sex as moderators. Methods The sample consisted of mothers and their healthy infants. Infant temperament was measured using the Infant Characteristics Questionnaire completed by the mothers at 6 weeks (n = 452) and 9 months (n = 258) postpartum. Mode of birth was classified into spontaneous vaginal birth (n = 347 for 6 weeks sample; 197 for 9 months sample), CS planned for medical reasons (n = 55; 28) and emergency CS (n = 50; 33). Results Multiple regression analysis revealed no main effects of birth mode, but showed a significant interaction between birth mode and parity indicating that emergency CS in firstborn infants was associated with more difficult temperament at 6 weeks. There were no significant associations between indications for CS and infant temperament, although breech presentation predicted difficult temperament at 9 months. Conclusion We largely failed to support the association between CS and infant temperament. Although our results suggest that emergency CS may be associated with temperament in firstborns, further research is needed to replicate this finding, preferably using observational measures to assess child temperament.

Date: 2013-09-27

Creator: Alexandra Pfister, Amy Johnson, Olaf Ellers, Hadley W. Horch

Access: Open access

Dendrite and axon growth and branching during development are regulated by a complex set of intracellular and external signals. However, the cues that maintain or influence adult neuronal morphology are less well understood. Injury and deafferentation tend to have negative effects on adult nervous systems. An interesting example of injury-induced compensatory growth is seen in the cricket, Gryllus bimaculatus. After unilateral loss of an ear in the adult cricket, auditory neurons within the central nervous system (CNS) sprout to compensate for the injury. Specifically, after being deafferented, ascending neurons (AN-1 and AN-2) send dendrites across the midline of the prothoracic ganglion where they receive input from auditory afferents that project through the contralateral auditory nerve (N5). Deafferentation also triggers contralateral N5 axonal growth. In this study, we quantified AN dendritic and N5 axonal growth at 30 h, as well as at 3, 5, 7, 14, and 20 days after deafferentation in adult crickets. Significant differences in the rates of dendritic growth between males and females were noted. In females, dendritic growth rates were non-linear; a rapid burst of dendritic extension in the first few days was followed by a plateau reached at 3 days after deafferentation. In males, however, dendritic growth rates were linear, with dendrites growing steadily over time and reaching lengths, on average, twice as long as in females. On the other hand, rates of N5 axonal growth showed no significant sexual dimorphism and were linear. Within each animal, the growth rates of dendrites and axons were not correlated, indicating that independent factors likely influence dendritic and axonal growth in response to injury in this system. Our findings provide a basis for future study of the cellular features that allow differing dendrite and axon growth patterns as well as sexually dimorphic dendritic growth in response to deafferentation. © 2013 Pfister, Johnson, Ellers and Horch.

Date: 2012-08-16

Creator: Jennifer W. Harden, Charles D. Koven, Chien Lu Ping, Gustaf Hugelius, A., David McGuire, Phillip Camill, Torre Jorgenson, Peter Kuhry, Gary J. Michaelson, Jonathan A. O'Donnell, Edward A.G. Schuur, Charles Tarnocai, Kristopher Johnson, Guido Grosse

Access: Open access

Deep soil profiles containing permafrost (Gelisols) were characterized for organic carbon (C) and total nitrogen (N) stocks to 3m depths. Using the Community Climate System Model (CCSM4) we calculate cumulative distributions of active layer thickness (ALT) under current and future climates. The difference in cumulative ALT distributions over time was multiplied by C and N contents of soil horizons in Gelisol suborders to calculate newly thawed C and N. Thawing ranged from 147 PgC with 10 PgN by 2050 (representative concentration pathway RCP scenario 4.5) to 436 PgC with 29 PgN by 2100 (RCP 8.5). Organic horizons that thaw are vulnerable to combustion, and all horizon types are vulnerable to shifts in hydrology and decomposition. The rates and extent of such losses are unknown and can be further constrained by linking field and modelling approaches. These changes have the potential for strong additional loading to our atmosphere, water resources, and ecosystems. © 2012. American Geophysical Union. All Rights Reserved.

Date: 2012-01-01

Creator: Zicheng Yu, D. W. Beilman, S. Frolking, G. M. MacDonald, N. T., Roulet, P. Camill, D. J. Charman

Access: Open access

Date: 2010-10-01

Creator: Hannah E. Reese, Richard J. McNally, Sadia Najmi, Nader Amir

Access: Open access

Cognitive theorists propose that attentional biases for threatening information play an important role in the development and maintenance of anxiety disorders. If attentional biases for threat figure in the maintenance of anxiety, then the experimental reduction of the bias for threat (attention training) should reduce anxiety. We randomly assigned 41 spider-fearful individuals to receive either attention training (n=20) or control procedures (n=21). We used a modified dot-probe discrimination paradigm with photographs of spiders and cows to train attention. Training reduced attentional bias for spiders, but only temporarily. Although both groups declined in spider fear and avoidance, reduction in attentional bias did not produce significantly greater symptom reduction in the training group than in the control group. However, reduction in attentional bias predicted reduction in self-reported fear for the training group. The reduction in attentional bias for threat may have been insufficiently robust to produce symptom reduction greater than that produced by exposure to a live spider and spider photographs alone. Alternatively, attention training may be an unsuitable intervention for spider fear. © 2010 Elsevier Ltd.

Date: 2019-07-17

Creator: Rachel J. Beane, Karen S. McNeal, R. Heather Macdonald

Access: Open access

What is the extent to which college and university geoscience faculty report using education practices that contribute to more inclusive learning environments and engage a diverse population of students? In the 2016 National Geoscience Faculty Survey, faculty answered questions about their practices in a specific introductory or major course they had taught in the previous two years, and about how they share and learn about the content and methods used in their teaching. Based on factor analysis, 22 of the survey questions divided into four categories associated with inclusive teaching practices: geoscientist representations, curricular choices, learning strategies, and career pathways. The self-reported use of practices across these four categories varies greatly, with some used by as many as 71% of faculty respondents whereas others by only 8%. These data provide new information on the current state of teaching practices in the geosciences with regard to inclusive practices, and establish a baseline to which responses from future surveys may be compared. Univariate general modeling combined with ANOVA tests on the responses to the questions shows that education practices differ based on variables such as teaching style, communication with colleagues, years of teaching experience, faculty type, institution type, class size, and course type (introductory or major). These differences suggest opportunities for focused geoscience faculty development around education practices that support the success of a diverse population of undergraduate students and the enhancement of inclusive learning environments in the geosciences.

Date: 2009-04-01

Creator: Rebecca Selden, Amy S. Johnson, Olaf Ellers

Access: Open access

Indirect predator-induced effects on growth, morphology and reproduction have been extensively studied in marine invertebrates but usually without consideration of size-specific effects and not at all in post-metamorphic echinoids. Urchins are an unusually good system, in which, to study size effects because individuals of various ages within one species span four orders of magnitude in weight while retaining a nearly isometric morphology. We tracked growth of urchins, Strongylocentrotus droebachiensis (0.013-161.385 g), in the presence or absence of waterborne cues from predatory Jonah crabs, Cancer borealis. We ran experiments at ambient temperatures, once for 4 weeks during summer and again, with a second set of urchins, for 22 weeks over winter. We used a scaled, cube-root transformation of weight for measuring size more precisely and for equalizing variance across sizes. Growth rate of the smallest urchins (summer: diameter; winter: diameter) decreased by 40-42% in response to crab cues. In contrast, growth rate of larger urchins was unaffected in the summer and increased in response to crab scent by 7% in the winter. At the end of the 22-week experiment, additional gonadal and skeletal variables were measured. Cue-exposed urchins developed heavier, thicker skeletons and smaller gonads, but no differences in spine length or jaw size. The differences depended on urchin size, suggesting that there are size-specific shifts in gonadal and somatic investment in urchins.

Date: 2008-09-04

Creator: Richard J. McNally, Hannah E. Reese

Access: Open access

Experimental psychopathologists have used cognitive psychology paradigms to elucidate information-processing biases in the anxiety disorders. A vast literature now suggests that patients with anxiety disorders are characterized by an attentional bias for threatening information and a bias toward threatening interpretations of ambiguous information. A memory bias favoring recall of threatening information occurs in panic disorder, but rarely in other anxiety disorders. New treatments involving the experimental modification of cognitive biases are promising.

Date: 2021-04-01

Creator: Bruce D. Kohorn, Jacob Dexter-Meldrum, Frances D.H. Zorensky, Salem Chabout, Gregory, Mouille, Susan Kohorn

Access: Open access

The cellulose-and pectin-rich plant cell wall defines cell structure, mediates defense against pathogens, and facilitates plant cell adhesion. An adhesion mutant screen of Arabidopsis hypocotyls identified a new allele of QUASIMODO2 (QUA2), a gene required for pectin accumulation and whose mutants have reduced pectin content and adhesion defects. A suppressor of qua2 was also isolated and describes a null allele of SABRE (SAB), which encodes a previously described plasma membrane protein required for longitudinal cellular expansion that organizes the tubulin cytoskeleton. sab mutants have increased pectin content, increased levels of expression of pectin methylesterases and extensins, and reduced cell surface area relative to qua2 and Wild Type, con-tributing to a restoration of cell adhesion.

Date: 1994-01-01

Creator: A. S. Johnson, M. A.R. Koehl

Access: Open access

Date: 2020-02-12

Creator: Rachel J. Beane, Ellen R. Altermatt, Ellen R. Iverson, R. Heather Macdonald

Access: Open access

The National Association of Geoscience Teachers’ Workshop for Early Career Geoscience Faculty: Teaching, Research, and Managing One’s Career has been offered annually since 1999. The five-day workshop with accompanying web resources employs a “whole faculty” approach to support geoscience faculty members during their transition into academic careers. More than 1,000 faculty members (53% female, 47% male) have attended the national workshop; 52% from doctoral-granting institutions, 15% master’s, 28% bachelor’s, and 5% associates. Evidence-based instructional practices are shared and modeled during workshop sessions. Situated learning theory grounds the workshop design and promotes the development of a community of practice. Examination of the 2016 National Geoscience Faculty Survey data using univariate analyses of covariance (ANCOVAs) showed that workshop alumni report spending more class time on student activities, questions, and discussion than faculty members who did not participate in the workshop, particularly on small group discussions or think-pair-share and in-class exercises (for introductory courses p < .05; for majors courses p < .001). Workshop alumni also were more likely than faculty who did not participate to report feeling part of a geoscience community that shares their goals, philosophy, and values for geoscience education (p < .01), more likely to report that interactions with this community help them to become better educators (p < .001), and more likely to attend talks on teaching methods or science education (p < .001). Although causality cannot be established without random assignment, these findings are consistent with the hypothesis that this discipline-based workshop with its holistic approach is effective at promoting evidence-based teaching strategies and a community of practice.

Date: 2000-01-01

Creator: Holly A. Leddy, Amy S. Johnson

Access: Open access

The podia of sea urchins function in locomotion, adhesion, feeding, and respiration; but different podia on a single urchin are often specialized to one or more of these tasks. We examined the morphology and material properties of podia of the green sea urchin, Strongylocentrotus droebachiensis, to determine whether, despite apparent similarities, they achieve functional specialization along the oral-aboral axis through the differentiation of distinct mechanical properties. We found that oral podia, which are used primarily for locomotion and adhesion, are stronger and thicker than aboral podia, which are used primarily for capturing drift material and as a respiratory surface. The functional role of ambital podia is more ambiguous; however, they are longer and are extended at a lower strain rate than other podial types. They are also stronger and stiffer than aboral podia. In addition, all podia become stronger and stiffer when extended at faster strain rates, in some cases by nearly an order of magnitude for an order of magnitude change in strain rate. This strain-rate dependence implies that resistance to rapid loading such as that imposed by waves is high compared to resistance to slower, self-imposed loads. Thus, the serially arranged podia of S. droebachiensis are functionally specialized along an oral-aboral axis by differences in their morphology and mechanical properties.

Date: 2010-09-06

Creator: Thomas Pietraho

Access: Open access

A conjecture of Bonnafé, Geck, Iancu, and Lam parametrizes Kazhdan-Lusztig left cells for unequal-parameter Hecke algebras in type Bn by families of standard domino tableaux of arbitrary rank. Relying on a family of properties outlined by Lusztig and the recent work of Bonnafé, we verify the conjecture and describe the structure of each cell as a module for the underlying Weyl group. © 2010 by The Editorial Board of the Nagoya Mathematical Journal.

Date: 1975-01-01

Creator: William H. Barker

Access: Open access

Let G be a connected semisimple Lie group with finite center and K a maximal compact subgroup. Denote (i) Harish-Chandra's Schwartz spaces by Cp(G)(0

Date: 2021-04-01

Creator: Christopher Chong, Yifan Wang, Donovan Maréchal, Efstathios G. Charalampidis, Miguel, Molerón, Alejandro J. Martínez

Access: Open access

We conduct an extensive study of nonlinear localized modes (NLMs), which are temporally periodic and spatially localized structures, in a two-dimensional array of repelling magnets. In our experiments, we arrange a lattice in a hexagonal configuration with a light-mass defect, and we harmonically drive the center of the chain with a tunable excitation frequency, amplitude, and angle. We use a damped, driven variant of a vector Fermi-Pasta-Ulam-Tsingou lattice to model our experimental setup. Despite the idealized nature of this model, we obtain good qualitative agreement between theory and experiments for a variety of dynamical behaviors. We find that the spatial decay is direction-dependent and that drive amplitudes along fundamental displacement axes lead to nonlinear resonant peaks in frequency continuations that are similar to those that occur in one-dimensional damped, driven lattices. However, we observe numerically that driving along other directions results in asymmetric NLMs that bifurcate from the main solution branch, which consists of symmetric NLMs. We also demonstrate both experimentally and numerically that solutions that appear to be time-quasiperiodic bifurcate from the branch of symmetric time-periodic NLMs.

Date: 2012-01-01

Creator: Bruce D. Kohorn, Susan L. Kohorn, Tanya Todorova, Gillian Baptiste, Kevin, Stansky, Meghan McCullough

Access: Open access

The plant cell wall is composed of a matrix of cellulose fibers, flexible pectin polymers, and an array of assorted carbohydrates and proteins. The receptor-like Wall-Associated Kinases (WAKs) of Arabidopsis bind pectin in the wall, and are necessary both for cell expansion during development and for a response to pathogens and wounding. Mitogen Activated Protein Kinases (MPKs) form a major signaling link between cell surface receptors and both transcriptional and enzyme regulation in eukaryotes, and Arabidopsis MPK6 and MPK3 indeed have important roles in development and the response to stress and pathogens. A dominant allele of WAK2 requires kinase activity and activates a stress response that includes an increased ROS accumulation and the up-regulation of numerous genes involved in pathogen resistance, wounding, and cell wall biogenesis. This dominant allele requires a functional pectin binding and kinase domain, indicating that it is engaged in a WAK signaling pathway. A null mutant of the major plasma membrane ROS-producing enzyme complex, rbohd/f does not suppress the WAK2cTAP-induced phenotype. A mpk6, but not a mpk3, null allele is able to suppress the effects of this dominant WAK2 mutation, thus distinguishing MPK3 and MPK6, whose activity previously was thought to be redundant. Pectin activation of gene expression is abated in a wak2-null, but is tempered by the WAK-dominant allele that induces elevated basal stress-related transcript levels. The results suggest a mechanism in which changes to the cell wall can lead to a large change in cellular responses and help to explain how pathogens and wounding can have general effects on growth. The Author 2011. Published by the Molecular Plant Shanghai Editorial Office in association with Oxford University Press on behalf of CSPB and IPPE, SIBS, CAS.2011 © The Author 2011. Published by the Molecular Plant Shanghai Editorial Office in association with Oxford University Press on behalf of CSPB and IPPE, SIBS, CAS.

Date: 2015-12-01

Creator: Melanie Stein, Jennifer Taback, Peter Wong

Access: Open access

Let τd(q) denote the group whose Cayley graph with respect to a particular generating set is the Diestel-Leader graph DLd(q), as described by Bartholdi, Neuhauser and Woess. We compute both Aut(τd(q)) and Out(τd(q)) for d ≥ 2, and apply our results to count twisted conjugacy classes in these groups when d ≥ 3. Specifically, we show that when d ≥ 3, the groups τd(q) have property R∞, that is, every automorphism has an infinite number of twisted conjugacy classes. In contrast, when d = 2 the lamplighter groups τ2(q) = Lq = Zq Z have property R∞ if and only if (q, 6)≠1.

Date: 2014-12-01

Creator: Anja Wartenberg, Jörg Linde, Ronny Martin, Maria Schreiner, Fabian, Horn, Ilse D. Jacobsen, Sabrina Jenull, Thomas Wolf, Karl Kuchler, Reinhard Guthke, Oliver Kurzai, Anja Forche, Christophe d'Enfert, Sascha Brunke, Bernhard Hube

Access: Open access

Following antifungal treatment, Candida albicans, and other human pathogenic fungi can undergo microevolution, which leads to the emergence of drug resistance. However, the capacity for microevolutionary adaptation of fungi goes beyond the development of resistance against antifungals. Here we used an experimental microevolution approach to show that one of the central pathogenicity mechanisms of C. albicans, the yeast-to-hyphae transition, can be subject to experimental evolution. The C. albicans cph1Δ/efg1Δ mutant is nonfilamentous, as central signaling pathways linking environmental cues to hyphal formation are disrupted. We subjected this mutant to constant selection pressure in the hostile environment of the macrophage phagosome. In a comparatively short time-frame, the mutant evolved the ability to escape macrophages by filamentation. In addition, the evolved mutant exhibited hyper-virulence in a murine infection model and an altered cell wall composition compared to the cph1Δ/efg1Δ strain. Moreover, the transcriptional regulation of hyphae-associated, and other pathogenicity-related genes became re-responsive to environmental cues in the evolved strain. We went on to identify the causative missense mutation via whole genome- and transcriptome-sequencing: a single nucleotide exchange took place within SSN3 that encodes a component of the Cdk8 module of the Mediator complex, which links transcription factors with the general transcription machinery. This mutation was responsible for the reconnection of the hyphal growth program with environmental signals in the evolved strain and was sufficient to bypass Efg1/Cph1-dependent filamentation. These data demonstrate that even central transcriptional networks can be remodeled very quickly under appropriate selection pressure.

Date: 2005-01-01

Creator: A.B. Levy

Access: Open access

Date: 2018-03-01

Creator: S. E. Kingston, P. Martino, M. Melendy, F. A. Reed, D. B., Carlon

Access: Open access

A key component to understanding the evolutionary response to a changing climate is linking underlying genetic variation to phenotypic variation in stress response. Here, we use a genome-wide association approach (GWAS) to understand the genetic architecture of calcification rates under simulated climate stress. We take advantage of the genomic gradient across the blue mussel hybrid zone (Mytilus edulis and Mytilus trossulus) in the Gulf of Maine (GOM) to link genetic variation with variance in calcification rates in response to simulated climate change. Falling calcium carbonate saturation states are predicted to negatively impact many marine organisms that build calcium carbonate shells – like blue mussels. We sampled wild mussels and measured net calcification phenotypes after exposing mussels to a ‘climate change’ common garden, where we raised temperature by 3°C, decreased pH by 0.2 units and limited food supply by filtering out planktonic particles >5 μm, compared to ambient GOM conditions in the summer. This climate change exposure greatly increased phenotypic variation in net calcification rates compared to ambient conditions. We then used regression models to link the phenotypic variation with over 170 000 single nucleotide polymorphism loci (SNPs) generated by genotype by sequencing to identify genomic locations associated with calcification phenotype, and estimate heritability and architecture of the trait. We identified at least one of potentially 2–10 genomic regions responsible for 30% of the phenotypic variation in calcification rates that are potential targets of natural selection by climate change. Our simulations suggest a power of 13.7% with our study's average effective sample size of 118 individuals and rare alleles, but a power of >90% when effective sample size is 900.

Date: 2020-12-01

Creator: J. Joe Hull, Melissa A. Stefanek, Patsy S. Dickinson, Andrew E. Christie

Access: Open access

Over the past decade, many new peptide families have been identified via in silico analyses of genomic and transcriptomic datasets. While various molecular and biochemical methods have confirmed the existence of some of these new groups, others remain in silico discoveries of computationally assembled sequences only. An example of the latter are the CCRFamides, named for the predicted presence of two pairs of disulfide bonded cysteine residues and an amidated arginine-phenylalanine carboxyl-terminus in family members, which have been identified from annelid, molluscan, and arthropod genomes/transcriptomes, but for which no precursor protein-encoding cDNAs have been cloned. Using routine transcriptome mining methods, we identified four Homarus americanus (American lobster) CCRFamide transcripts that share high sequence identity across the predicted open reading frames but more limited conservation in their 5′ terminal ends, suggesting the Homarus gene undergoes alternative splicing. RT-PCR profiling using primers designed to amplify an internal fragment common to all of the transcripts revealed expression in the supraoesophageal ganglion (brain), eyestalk ganglia, and cardiac ganglion. Variant specific profiling revealed a similar profile for variant 1, eyestalk ganglia specific expression of variant 2, and an absence of variant 3 expression in the cDNAs examined. The broad distribution of CCRFamide transcript expression in the H. americanus nervous system suggests a potential role as a locally released and/or circulating neuropeptide. This is the first report of the cloning of a CCRFamide-encoding cDNA from any species, and as such, provides the first non-in silico support for the existence of this invertebrate peptide family.

Date: 2019-10-01

Creator: Patsy S. Dickinson, Heidi M. Samuel, Elizabeth A. Stemmler, Andrew E. Christie

Access: Open access

The SIFamides are a broadly conserved arthropod peptide family characterized by the C-terminal motif –SIFamide. In decapod crustaceans, two isoforms of SIFamide are known, GYRKPPFNGSIFamide (Gly1-SIFamide), which is nearly ubiquitously conserved in the order, and VYRKPPFNGSIFamide (Val1-SIFamide), known only from members of the astacidean genus Homarus. While much work has focused on the identification of SIFamide isoforms in decapods, there are few direct demonstrations of physiological function for members of the peptide family in this taxon. Here, we assessed the effects of Gly1- and Val1-SIFamide on the cardiac neuromuscular system of two closely related species of Cancer crab, Cancer borealis and Cancer irroratus. In each species, both peptides were cardioactive, with identical, dose-dependent effects elicited by both isoforms in a given species. Threshold concentrations for bioactivity are in the range typically associated with hormonal delivery, i.e., 10−9 to 10−8 M. Interestingly, and quite surprisingly, while the predicted effects of SIFamide on cardiac output are similar in both C. borealis and C. irroratus, frequency effects predominate in C. borealis, while amplitude effects predominate in C. irroratus. These findings suggest that, while SIFamide is likely to increase cardiac output in both crabs, the mechanism through which this is achieved is different in the two species. Immunohistochemical/mass spectrometric data suggest that SIFamide is delivered to the heart hormonally rather than locally, with the source of hormonal release being midgut epithelial endocrine cells in both Cancer species. If so, midgut-derived SIFamide may function as a regulator of cardiac output during the process of digestion.

Date: 2020-12-01

Creator: Andrew E. Christie, Cindy D. Rivera, Catherine M. Call, Patsy S. Dickinson, Elizabeth A., Stemmler, J. Joe Hull

Access: Open access

Over the past decade, in silico genome and transcriptome mining has led to the identification of many new crustacean peptide families, including the agatoxin-like peptides (ALPs), a group named for their structural similarity to agatoxin, a spider venom component. Here, analysis of publicly accessible transcriptomes was used to expand our understanding of crustacean ALPs. Specifically, transcriptome mining was used to investigate the phylogenetic/structural conservation, tissue localization, and putative functions of ALPs in decapod species. Transcripts encoding putative ALP precursors were identified from one or more members of the Penaeoidea (penaeid shrimp), Sergestoidea (sergestid shrimps), Caridea (caridean shrimp), Astacidea (clawed lobsters and freshwater crayfish), Achelata (spiny/slipper lobsters), and Brachyura (true crabs), suggesting a broad, and perhaps ubiquitous, conservation of ALPs in decapods. Comparison of the predicted mature structures of decapod ALPs revealed high levels of amino acid conservation, including eight identically conserved cysteine residues that presumably allow for the formation of four identically positioned disulfide bridges. All decapod ALPs are predicted to have amidated carboxyl-terminals. Two isoforms of ALP appear to be present in most decapod species, one 44 amino acids long and the other 42 amino acids in length, both likely generated by alternative splicing of a single gene. In carideans, a gene or terminal exon duplication appears to have occurred, with alternative splicing producing four ALPs, two 44 and two 42 amino acid isoforms. The identification of ALP precursor-encoding transcripts in nervous system-specific transcriptomes (e.g., Homarus americanus brain, eyestalk ganglia, and cardiac ganglion assemblies, finding confirmed using RT-PCR) suggests that members of this peptide family may serve as locally-released and/or hormonally-delivered neuromodulators in decapods. Their detection in testis- and hepatopancreas-specific transcriptomes suggests that members of the ALP family may also play roles in male reproduction and innate immunity/detoxification.

Date: 2020-06-01

Creator: Andrew E. Christie, J. Joe Hull, Patsy S. Dickinson

Access: Open access

Gap junctions are physical channels that connect adjacent cells, permitting the flow of small molecules/ions between the cytoplasms of the coupled units. Innexin/innexin-like proteins are responsible for the formation of invertebrate gap junctions. Within the nervous system, gap junctions often function as electrical synapses, providing a means for coordinating activity among electrically coupled neurons. While some gap junctions allow the bidirectional flow of small molecules/ions between coupled cells, others permit flow in one direction only or preferentially. The complement of innexins present in a gap junction determines its specific properties. Thus, understanding innexin diversity is key for understanding the full potential of electrical coupling in a species/system. The decapod crustacean cardiac ganglion (CG), which controls cardiac muscle contractions, is a simple pattern-generating neural network with extensive electrical coupling among its circuit elements. In the lobster, Homarus americanus, prior work suggested that the adult neuronal innexin complement consists of six innexins (Homam-Inx1-4 and Homam-Inx6-7). Here, using a H. americanus CG-specific transcriptome, we explored innexin complement in this portion of the lobster nervous system. With the exception of Homam-Inx4, all of the previously described innexins appear to be expressed in the H. americanus CG. In addition, transcripts encoding seven novel putative innexins (Homam-Inx8-14) were identified, four (Homam-Inx8-11) having multiple splice variants, e.g., six for Homam-Inx8. Collectively, these data indicate that the innexin complement of the lobster nervous system in general, and the CG specifically, is likely significantly greater than previously reported, suggesting the possibility of expanded gap junction diversity and function in H. americanus.

Date: 1982-11-11

Creator: Bruce D. Kohorn, Peter M.m. Rae

Access: Open access

Tandem repeats of ribosomal RNA transcription units in Drosophila melanogaster are separated by a nontranscribed spacer that is comprised in part of serial repeats of a 0.24 kb sequence. DNA sequence analysis shows that such repeats are imperfect copies of a region that includes the site of in vivo rRNA transcription initiation (ca. -240 to +30). Subclones of the rDNA spacer that are copies of the sequence extending from -34 through the initiation site support detectable in vitro transcription in a mixture involving a Drosophila cell-free extract, but accurate in vitro transcription is considerably enhanced when a nontranscribed spacer template includes a copy of the sequence extending upstream of -34. From a comparison of the sequence and transcription template-effectiveness of various rDNA subclones, we infer that a major promoter of RNA polymerase I activity lies between -150 and -30 in the rDNA nontranscribed spacer. The nontranscribed spacer copies of the initiation region are less effective templates for transcription than is the region of in vivo initiation and there are differences between spacer repeates and the authentic sequence downstream of -240 that may account for this. © 1982 IRL Press Limited.

Date: 1995-06-01

Creator: F. Montes de Oca, M. L. Zeeman

Access: Open access

We generalise and unify some recent results about extinction in nth-order nonautonomous competitive Lotka-Volterra systems. For each r ≤ n, we show that if the coefficients are continuous, bounded by strictly positive constants, and satisfy certain inequalities, then any solution with strictly positive initial values has the property that n - r of its components vanish, whilst the remaining r components asymptotically approach a canonical solution of an r-dimensional restricted system. In other words, r of the species being modeled survive whilst the remaining n - r are driven to extinction. © 1995 Academic Press, Inc.

Date: 2011-12-01

Creator: Azer Akhmedov, Melanie Stein, Jennifer Taback

Access: Open access

We produce a sequence of markings Sk of Thompson's group F within the space Gn of all marked n-generator groups so that the sequence (F, Sk) converges to the free group on n generators, for n ≥ 3. In addition, we give presentations for the limits of some other natural (convergent) sequences of markings to consider on F within G3, including (F, {x0, x1, xn}) and (F, {x0, x1, x0n}) © 2011 Springer Science+Business Media B.V.

Date: 2005-09-22

Creator: Sean Cleary, Jennifer Taback

Access: Open access

We explore the geometry of the Cayley graphs of the lamplighter groups and a wide range of wreath products. We show that these groups have dead end elements of arbitrary depth with respect to their natural generating sets. An element w in a group G with finite generating set X is a dead end element if no geodesic ray from the identity to w in the Cayley graph Γ(G, X) can be extended past w. Additionally, we describe some non-convex behaviour of paths between elements in these Cayley graphs and seesaw words, which are potential obstructions to these graphs satisfying the k-fellow traveller property. © The Author 2005. Published by Oxford University Press. All rights reserved.

Date: 2009-12-01

Creator: Bruce D. Kohorn, Susan Johansen, Akira Shishido, Tanya Todorova, Rhysly, Martinez, Elita Defeo, Pablo Obregon

Access: Open access

The angiosperm extracellular matrix, or cell wall, is composed of a complex array of cellulose, hemicelluose, pectins and proteins, the modification and regulated synthesis of which are essential for cell growth and division. The wall associated kinases (WAKs) are receptor-like proteins that have an extracellular domain that bind pectins, the more flexible portion of the extracellular matrix, and are required for cell expansion as they have a role in regulating cellular solute concentrations. We show here that both recombinant WAK1 and WAK2 bind pectin in vitro. In protoplasts pectins activate, in a WAK2-dependent fashion, the transcription of vacuolar invertase, and a wak2 mutant alters the normal pectin regulation of mitogen-activated protein kinases. Microarray analysis shows that WAK2 is required for the pectin activation of numerous genes in protoplasts, many of which are involved in cell wall biogenesis. Thus, WAK2 plays a major role in signaling a diverse array of cellular events in response to pectin in the extracellular matrix. © 2009 Blackwell Publishing Ltd.

Date: 2000-01-01

Creator: B. D. Kohorn

Access: Open access

Date: 1990-01-01

Creator: Bruce D. Kohorn

Access: Open access

Eukaryotic light harvesting proteins (LHCPs) bind pigments and assemble into complexes (LHCs) that channel light energy into photosynthetic reaction centers. The structures of several prokaryotic LHCPs are known and histidines are important for the binding of the associated pigments. It has been difficult to predict how the eukaryotic LHCPs associate with pigments as the structure of the major LHCP of photosystem II is not yet known. While each LHCPII binds approximately 13 chlorophylls the protein contains only three histidines, one in each putative transmembrane helix. Experiments that use isolated pea (Pisum sativum L.) chloroplasts and mutant LHCPII synthesized in vitro show that the substitution of either an alanine or an arginine for each histidine residue inhibits some aspect of LHCII assembly. The histidine of the first membrane helix, but not the second or third, may be involved in the transport across the chloroplast envelope. No histidine alone is essential for the insertion of LHCP into thylakoid membranes, yet arginine substitutions are more inhibitory than those of alanine. The histidine replacements have their most pronounced effect on the assembly of LHCP into LHCII.

Date: 2019-01-01

Creator: Christopher Chong, Andre Foehr, Efstathios G. Charalampidis, Panayotis G. Kevrekidis, Chiara, Daraio

Access: Open access

In this article, the existence, stability and bifurcation structure of time-periodic solutions (including ones that also have the property of spatial localization, i.e., breathers) are studied in an array of cantilevers that have magnetic tips. The repelling magnetic tips are responsible for the intersite nonlinearity of the system, whereas the cantilevers are responsible for the onsite (potentially nonlinear) force. The relevant model is of the mixed Fermi-Pasta-Ulam-Tsingou and Klein-Gordon type with both damping and driving. In the case of base excitation, we provide experimental results to validate the model. In particular, we identify regions of bistability in the model and in the experiment, which agree with minimal tuning of the system parameters. We carry out additional numerical explorations in order to contrast the base excitation problem with the boundary excitation problem and the problem with a single mass defect. We find that the base excitation problem is more stable than the boundary excitation problem and that breathers are possible in the defect system. The effect of an onsite nonlinearity is also considered, where it is shown that bistability is possible for both softening and hardening cubic nonlinearities.

Date: 2007-03-01

Creator: Sean Cleary, Jennifer Taback

Access: Open access

Rotation distance measures the difference in shape between binary trees of the same size by counting the minimum number of rotations needed to transform one tree to the other. We describe several types of rotation distance where restrictions are put on the locations where rotations are permitted, and provide upper bounds on distances between trees with a fixed number of nodes with respect to several families of these restrictions. These bounds are sharp in a certain asymptotic sense and are obtained by relating each restricted rotation distance to the word length of elements of Thompson's group F with respect to different generating sets, including both finite and infinite generating sets. © World Scientific Publishing Company.

Date: 2012-05-01

Creator: Florence F. Sun, Justine E. Johnson, Martin P. Zeidler, Jack R. Bateman

Access: Open access

Balancer chromosomes are critical tools for Drosophila genetics. Many useful transgenes are inserted onto balancers using a random and inefficient process. Here we describe balancer chromosomes that can be directly targeted with transgenes of interest via recombinase-mediated cassette exchange (RMCE). ©2012 Sun et al.

Date: 2016-01-27

Creator: V. Douhovnikoff, S. H. Taylor, E. L.G. Hazelton, C. M. Smith, J., O'Brien

Access: Open access

The fitness costs of reproduction by clonal growth can include a limited ability to adapt to environmental and temporal heterogeneity. Paradoxically, some facultatively clonal species are not only able to survive, but colonize, thrive and expand in heterogeneous environments. This is likely due to the capacity for acclimation (sensu stricto) that compensates for the fitness costs and complements the ecological advantages of clonality. Introduced Phragmites australis demonstrates great phenotypic plasticity in response to temperature, nutrient availability, geographic gradient, water depths, habitat fertility, atmospheric CO2, interspecific competition and intraspecific competition for light. However, no in situ comparative subspecies studies have explored the difference in plasticity between the non-invasive native lineage and the highly invasive introduced lineage. Clonality of the native and introduced lineages makes it possible to control for genetic variation, making P. australis a unique system for the comparative study of plasticity. Using previously identified clonal genotypes, we investigated differences in their phenotypic plasticity through measurements of the lengths and densities of stomata on both the abaxial (lower) and adaxial (upper) surfaces of leaves, and synthesized these measurements to estimate impacts on maximum stomatal conductance to water (gwmax). Results demonstrated that at three marsh sites, invasive lineages have consistently greater gwmax than their native congeners, as a result of greater stomatal densities and smaller stomata. Our analysis also suggests that phenotypic plasticity, determined as within-genotype variation in gwmax, of the invasive lineage is similar to, or exceeds, that shown by the native lineage.

Date: 2011-08-01

Creator: Kimberly A. Tice, D. B. Carlon

Access: Open access

Genome scans have identified candidate regions of the genome undergoing selection in a wide variety of organisms, yet have rarely been applied to broadly dispersing marine organisms experiencing divergent selection pressures, where high recombination rates can reduce the extent of linkage disequilibrium (LD) and the ability to detect genomic regions under selection. The broadly dispersing periwinkle Echinolittorina hawaiiensis exhibits a heritable shell sculpture polymorphism that is correlated with environmental variation. To elucidate the genetic basis of phenotypic variation, a genome scan using over 1000 AFLP loci was conducted on smooth and sculptured snails from divergent habitats at four replicate sites. Approximately 5% of loci were identified as outliers with Dfdist, whereas no outliers were identified by BayeScan. Closer examination of the Dfdist outliers supported the conclusion that these loci were false positives. These results highlight the importance of controlling for Type I error using multiple outlier detection approaches, multitest corrections and replicate population comparisons. Assuming shell phenotypes have a genetic basis, our failure to detect outliers suggests that the life history of the target species needs to be considered when designing a genome scan. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

Date: 2007-01-01

Creator: Nadia V. Celis Salgado, Fanny Buitrago

Access: Open access

Date: 2013-04-24

Creator: Jack R. Bateman, Michael F. Palopoli, Sarah T. Dale, Jennifer E. Stauffer, Anita L., Shah, Justine E. Johnson, Conor W. Walsh, Hanna Flaten, Christine M. Parsons

Access: Open access

Site-specific recombinases (SSRs) are valuable tools for manipulating genomes. In Drosophila, thousands of transgenic insertions carrying SSR recognition sites have been distributed throughout the genome by several large-scale projects. Here we describe a method with the potential to use these insertions to make custom alterations to the Drosophila genome in vivo. Specifically, by employing recombineering techniques and a dual recombinase-mediated cassette exchange strategy based on the phiC31 integrase and FLP recombinase, we show that a large genomic segment that lies between two SSR recognition-site insertions can be "captured" as a target cassette and exchanged for a sequence that was engineered in bacterial cells. We demonstrate this approach by targeting a 50-kb segment spanning the tsh gene, replacing the existing segment with corresponding recombineered sequences through simple and efficient manipulations. Given the high density of SSR recognition-site insertions in Drosophila, our method affords a straightforward and highly efficient approach to explore gene function in situ for a substantial portion of the Drosophila genome. © 2013 by the Genetics Society of America.

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.

Date: 2024-01-01

Creator: Mary Alta Rogalski, Elizabeth S Baker, Clara M Benadon

Access: Open access

Increasing application of road deicing agents (e.g., NaCl) has caused widespread salinization of freshwater environments. Chronic exposure to toxic NaCl levels can impact freshwater biota at genome to ecosystem scales, yet the degree of harm caused by road salt pollution is likely to vary among habitats and populations. The background ion chemistry of freshwater environments may strongly impact NaCl toxicity, with greater harm occurring in ion-poor, soft water conditions. In addition, populations exposed to salinization may evolve increased NaCl tolerance. Notably, if organisms are adapted to their natal lake water chemistry, toxicity responses may also vary among populations in a given test medium. We examined how this evolutionary and environmental context may interact in shaping NaCl toxicity with a pair of laboratory reciprocal transplant toxicity experiments, using natural populations of the water flea Daphnia ambigua from three lakes differing in ion availability. The lake water environment strongly influenced NaCl toxicity in both trials. NaCl greatly reduced reproduction and r in lake water from a low-ion/ calcium-poor environment compared with water from both a calcium-rich lake and an ion-rich coastal lake. Daphnia from this coastal lake were most robust to the effects of NaCl. A significant population x environment interaction shaped survival in both trials, suggesting that local adaptation to the test waters used contributed to toxicity responses. Our findings that the lake water environment, adaptation to that environment, and adaptation to a focal contaminant may shape toxicity demonstrate the importance of considering environmental and biological complexity in mitigating pollution impacts.

Date: 2016-09-21

Creator: Cathy M. Trudinger, Paul J. Fraser, David M. Etheridge, William T. Sturges, Martin K. Vollmer, Matt Rigby, Patricia Martinerie, Jens Mühle, David R. Worton, Paul B. Krummel, L. Paul Steele, Benjamin R. Miller, Johannes Laube, Francis S. Mani, Peter J. Rayner, Christina M. Harth, Emmanuel Witrant, Thomas Blunier, Jakob Schwander, Simon O'Doherty, Mark Battle

Access: Open access

Perfluorocarbons (PFCs) are very potent and long-lived greenhouse gases in the atmosphere, released predominantly during aluminium production and semiconductor manufacture. They have been targeted for emission controls under the United Nations Framework Convention on Climate Change. Here we present the first continuous records of the atmospheric abundance of CF4 (PFC-14), C2F6 (PFC-116) and C3F8 (PFC-218) from 1800 to 2014. The records are derived from high-precision measurements of PFCs in air extracted from polar firn or ice at six sites (DE08, DE08-2, DSSW20K, EDML, NEEM and South Pole) and air archive tanks and atmospheric air sampled from both hemispheres. We take account of the age characteristics of the firn and ice core air samples and demonstrate excellent consistency between the ice core, firn and atmospheric measurements. We present an inversion for global emissions from 1900 to 2014. We also formulate the inversion to directly infer emission factors for PFC emissions due to aluminium production prior to the 1980s. We show that 19th century atmospheric levels, before significant anthropogenic influence, were stable at 34.1 ± 0.3 ppt for CF4 and below detection limits of 0.002 and 0.01 ppt for C2F6 and C3F8, respectively. We find a significant peak in CF4 and C2F6 emissions around 1940, most likely due to the high demand for aluminium during World War II, for example for construction of aircraft, but these emissions were nevertheless much lower than in recent years. The PFC emission factors for aluminium production in the early 20th century were significantly higher than today but have decreased since then due to improvements and better control of the smelting process. Mitigation efforts have led to decreases in emissions from peaks in 1980 (CF4) or early-to-mid-2000s (C2F6 and C3F8) despite the continued increase in global aluminium production; however, these decreases in emissions appear to have recently halted. We see a temporary reduction of around 15 % in CF4 emissions in 2009, presumably associated with the impact of the global financial crisis on aluminium and semiconductor production.

Date: 2017-12-15

Creator: Kenneth A. Dennison, Thomas W. Baumgarte

Access: Open access

Trumpet geometries play an important role in numerical simulations of black hole spacetimes, which are usually performed under the assumption of asymptotic flatness. Our Universe is not asymptotically flat, however, which has motivated numerical studies of black holes in asymptotically de Sitter spacetimes. We derive analytical expressions for trumpet geometries in Schwarzschild-de Sitter spacetimes by first generalizing the static maximal trumpet slicing of the Schwarzschild spacetime to static constant mean curvature trumpet slicings of Schwarzschild-de Sitter spacetimes. We then switch to a comoving isotropic radial coordinate which results in a coordinate system analogous to McVittie coordinates. At large distances from the black hole the resulting metric asymptotes to a Friedmann-Lemaître-Robertson-Walker metric with an exponentially-expanding scale factor. While McVittie coordinates have another asymptotically de Sitter end as the radial coordinate goes to zero, so that they generalize the notion of a "wormhole" geometry, our new coordinates approach a horizon-penetrating trumpet geometry in the same limit. Our analytical expressions clarify the role of time-dependence, boundary conditions and coordinate conditions for trumpet slices in a cosmological context, and provide a useful test for black hole simulations in asymptotically de Sitter spacetimes.

Date: 2006-01-01

Creator: J.A. Faber, T.W. Baumgarte, S.L. Shapiro, K. Taniguchi

Access: Open access

Date: 2004-01-01

Creator: I.A. Morrison, T.W. Baumgarte, S.L. Shapiro

Access: Open access

Date: 1992-01-01

Creator: R. Ammar, P. Baringer, D. Coppage, R. Davis, M., Kelly, N. Kwak, H. Lam, S. Ro, Y. Kubota, M. Lattery, J. K. Nelson, D. Perticone, R. Poling, S. Schrenk, R. Wang, M. S. Alam, I. J. Kim, B. Nemati, V. Romero, C. R. Sun, P. N. Wang, M. M. Zoeller, G. Crawford, R. Fulton, K. K. Gan, H. Kagan, R. Kass, J. Lee, R. Malchow, F. Morrow, M. K. Sung

Access: Open access

Using data accumulated by the CLEO I detector operating at the Cornell Electron Storage Ring, we have measured the ratio R=( e» e ) 1 where " 1 is the decay rate to final states with one charged particle. We find R=0.2231 0.0044 0.0073 where the first error is statistical and the second is systematic. Together with the measured topological one-charged-particle branching fraction, this yields the branching fraction of the lepton to electrons, Be=0.192 0.004 0.006. © 1992 The American Physical Society.

Date: 1990-01-01

Creator: P. Avery, D. Besson, L. Garren, J. Yelton, K., Kinoshita, F. M. Pipkin, M. Procario, Richard Wilson, J. Wolinski, D. Xiao, Y. Zhu, R. Ammar, P. Baringer, D. Coppage, R. Davis, P. Haas, M. Kelly, N. Kwak, Ha Lam, S. Ro, Y. Kubota, J. K. Nelson, D. Perticone, R. Poling, R. Fulton, T. Jensen, D. R. Johnson, H. Kagan, R. Kass, F. Morrow, J. Whitmore

Access: Open access

We report a measurement of polarization in the two-body decay c+, in nonresonant e+e- interactions from data taken with the CLEO detector. Using these data we have determined the parity-violating asymmetry decay parameter c to be -1.0-0.0+0.4. We see no evidence for significant c+ polarization. © 1990 The American Physical Society.