cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Supplementary information from Earlier colony arrival but no trend in hatching timing in two congeneric seabirds (Uria spp.) across the North Atlantic
Creators: name: Merkel, Benjamin
name: Descamps, Sébastien
name: Yoccoz, Nigel G.
name: Jóhannis Danielsen
name: Daunt, Francis
name: Erikstad, Kjell E.
name: Ezhov, Aleksey V.
name: Grémillet, David
name: Gavrilo, Maria
name: Svein-Håkon Lorentsen
name: Reiertsen, Tone K.
name: Steen, Harald
name: Systad, Geir H.
name: Þórarinsson, Þorkell Lindberg
name: Wanless, Sarah
name: Strøm, Hallvard
Publisher: name: The Royal Society
Year: 2019
Subjects: subject: Ecology
subject: FOS: Biological sciences
subject: 60801 Animal Behaviour

description: A global analysis recently showed that seabird breeding phenology (as the timing of egg-laying and hatching) does not, on average, respond to temperature changes or advance with time (Keogan et al. 2018 Nat. Clim. Change 8, 313–318). This group, the most threatened of all birds, is therefore prone to spatio-temporal mismatches with their food resources. Yet, other aspects of the breeding phenology may also have marked incidence on breeding success, such as the arrival date of adults at the breeding site following winter migration. Here, we used a large tracking dataset of two congeneric seabirds breeding in 14 colonies across 18° latitudes, to show that arrival date at the colony was highly variable between colonies and species (ranging 80 days) and advanced 1.4 days/year while timing of egg-laying remained unchanged, resulting in an increasing pre-laying duration between 2009 and 2018. Thus, we demonstrate that potentially not all components of seabird breeding phenology are insensitive to changing environmental conditions.
Supplemental Material from Rapid and positive responses of plants to lower precipitation predictability.
Creators: name: Martí March-Salas
name: Kleunen, Mark Van
name: Fitze, Patrick S.
Publisher: name: The Royal Society
Year: 2019
Subjects: subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: Environmental Science
subject: Ecology

description: Current climate change is characterized by an increase in weather variability, which includes altered means, variance and predictability of weather parameters, and which may affect an organism's ecology and evolution. Few studies have experimentally manipulated the variability of weather parameters, and very little is known about the effects of changes in the intrinsic predictability of weather parameters on living organisms. Here, we experimentally tested the effects of differences in intrinsic precipitation-predictability on two herbaceous plants (Onobrychis viciifolia and Papaver rhoeas). Lower precipitation-predictability led to phenological advance and to an increase in reproductive success, and population growth. Both species exhibited rapid transgenerational responses in phenology and fitness-related traits across four generations that mitigated most effects of precipitation-predictability on fitness proxies of ancestors. Transgenerational responses appeared to be the result of changes in phenotypic plasticity rather than local adaptation. They mainly existed with respect to conditions prevailing during early, but not during late growth, suggesting that responses to differences in predictability during late growth might be more difficult. The results show that lower short-term predictability of precipitation positively affected fitness, rapid transgenerational responses existed and different time scales of predictability (short-term, seasonal and transgenerational predictability) may affect organisms differently. This shows that the time scale of predictability should be considered in evolutionary and ecological theories, and in assessments of the consequences of climate change.
A simple and robust method for partially matched samples using the p -values pooling approach
Creators: name: Huang, Bo
name: Kuan, Pei Fen
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2013

description: This paper focuses on statistical analyses in scenarios where some samples from the matched pairs design are missing, resulting in partially matched samples. Motivated by the idea of meta-analysis, we recast the partially matched samples as coming from two experimental designs, and propose a simple yet robust approach based on the weighted Z-test to integrate the p-values computed from these two designs. We show that the proposed approach achieves better operating characteristics in simulations and a case study, compared to existing methods for partially matched samples.
Reproduction and population dynamics of Perinereis cultrifera (Polychaeta: Nereididae) of the Atlantic coast, El Jadida, Morocco
Creators: name: ROUHI, Abdelali
name: SIF, Jamila
name: GILLET, Patrick
name: DEUTSCH, Bruno
Publisher: name: Station Biologique de Roscoff (SBR)
Year: 2008

description: Perinereis cultrifera (Grube, 1840) is a common species along the Atlantic coast of El Jadida (Morocco). Field
 investigations of the reproduction and population dynamics were carried out from November 2003 to October 2004.
 Monthly samples were taken in the intertidal zone at low tide. The reproduction is of atokous type, the laying took place
 from April until the end of May and the females can contain up to 4947 eggs. The annual average biomass (dry weight) of
 the population was B = 9.4 g.m-2, with an annual production P = 21.5 g.m-2 and a ratio P/B = 2.3 year-1. The algorithm EM
 was used for the separation of the cohort.
Reuse of Digital Heritage in the Library, Today and Tomorrow. The Case of the National Library of Netherlands
Creators: name: Wilms, Lotte
Publisher: name: Zenodo
Year: 2016
Subjects: digital scholarship
digital humanities
cultural heritage
digitisation

description: Reuse of digital heritage in the library, today and tomorrow; The case of the National Library of the Netherlands The Koninklijke Bibliotheek (KB), National Library of the Netherlands is a research library with a broad collection in the fields of Dutch history, culture and society, and as a national library collects and stores all (digital) publications that appear in the Netherlands, as well as a part of the international publications about the Netherlands. The KB has planned to have digitised and OCRed its entire collection of books, periodicals and newspapers from 1470 onward by the year 2030. Already in 2016, about 15% of this enormous task was completed, either by the KB itself or via public-private partnerships as Google Books and ProQuest. Over 20 million book-, newspaper- and magazine papers are currently available via the search portal www.delpher.nl. The KB is one of the major hubs of the Digital Heritage Network that have recently published the National Digital Heritage Strategy. The library also hosts a Digital Humanities team, aimed to support research of the digitised collection in bulk. In the two years that this team operates in the international Digital Humanities field, a great deal of experience has been gathered in making the digital collection available for (research) communities. This presentation will present the activities that the Koninklijke Bibliotheek undertakes with regards to reuse, how they fit in the framework of the National Digital Heritage Strategy and what we aim to achieve with this network.
description: Keynote for the 4th 4th Conference on Heritage Libraries The Lives and New Lives of Heritage: Reuse and the Future
A new species of the genus Arhodeoporus (Acari: Halacaridae) from Zanzibar, Tanzania
Creators: name: CHATTERJEE, Tapas
name: PEIC, Vladimir
name: DE TROCH, Marleen
Publisher: name: Station Biologique de Roscoff (SBR)
Year: 2008

description: Arhodeoporus tanzanicus sp. nov. is described on the basis of the specimens collected from Pingwe, the east
 coast of Zanzibar, Tanzania. This is the first record of the genus from Tanzania. This species is a member of the longirostris
 group and characterized by dorsal seta-5 posterior to the anterior gland pore on posterior dorsal plate (PD), anterior margin
 of PD truncate, ocular plate with long tail surpassing the level of anterior gland pore on PD, rostrum longer than gnatho-
 somal base, tip of rostrum extending to basal part of fourth palpal segment, bipectinate setae on tibiae I-IV: 0-2-1-1.
Baryon states with hidden charm in the extended local hidden gauge approach
Creators: name: Uchino, T.
name: Liang, Wei-Hong
name: Oset, E.
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The s-wave interaction of $\bar{D} Λ_c, \bar{D} Σ_c, \bar{D} Λ_c, \bar{D}{}^* Σ_c$ and $\bar{D}Σ^*_c, \bar{D}{}^*Σ^*_c$, is studied within a unitary coupled channels scheme with the extended local hidden gauge approach. In addition to the Weinberg-Tomozawa term, several additional diagrams via the pion-exchange are also taken into account as box potentials. Furthermore, in order to implement the full coupled channels calculation, some of the box potentials which mix the vector-baryon and pseudoscalar-baryon sectors are extended to construct the effective transition potentials. As a result, we have observed six possible states in several angular momenta. Four of them correspond to two pairs of admixture states, two of $\bar{D}Σ_c$ - $\bar{D}{}^*Σ_c$ with $J^P = 1/2^-$, and two of $\bar{D}Σ^*_c$ - $\bar{D}{}^*Σ^*_c$ with $J^P = 3/2^-$. Moreover, we find a $\bar{D}{}^* Σ_c$ resonance which couples to the $\bar{D}Λ_c$ channel and one spin degenerated bound state of $\bar{D}{}^*Σ^*_c$ with $J^P = 1/2^-, 5/2^-$.
description: 24 pages, 6 figures
Induction of larval metamorphosis, survival and growth of early juveniles of the burrowing echinoid Echinocardium cordatum (Echinodermata)
Creators: name: NUNES, Cristina De Amaral P.
name: JANGOUX, Michel
Publisher: name: Station Biologique de Roscoff (SBR)
Year: 2008

description: Recruitment in most marine invertebrates depends on the larval supply and the success of metamorphosis as well
 as on the growth and survival of the early juveniles. These two aspects of the early-life history of the burrowing echinoid
 Echinocardium cordatum have been investigated in the laboratory. Seven natural substrata were tested with competent
 larvae to assess their metamorphosis inducing capacity. Sediment (the natural substratum inhabited by the echinoids) - har-
 bouring or not conspecific adults - was the most effective inductor, with nearly 100% metamorphosis. Cleaned sediment
 was much less inducing, indicating that associated microbes and/or organic matter might be the cues responsible for the
 starting of metamorphosis. Coralline algae were the second most inductive substratum (50-64% metamorphosis), while
 biofilm, detritic particles and green macroalgae (Enteromorpha sp.) were significantly less effective. A 47d survey of the
 survival and growth of early juvenile E. cordatum in sediment with various grain sizes (very coarse, coarse, medium, fine
 and silty) was undertaken. Survival was the highest in the medium grain sand, although the obtained differences among the
 five sediment types were not statistically significant. During the first month, growth was significantly faster in the finer
 sediments (fine and silt), but at the end of the experiment all sediment types were equivalent in terms of sizes reached by
 the juveniles. The results indicate that neither the competent larvae nor the juveniles appear to be very specific in terms of
 sediment type, suggesting that other factors (e.g., mortality or migration) would determine the distribution and abundance
 of adult populations.
THE GENERA OPHELIA AND AMPELISCA OF THE ROSCOFF REGION - EXAMPLES OF ALLOTOPY AND SYNTOPY IN MARINE COMMUNITIES OF THE LOOSE SUBSTRATUM
Creators: name: Dauvin, J. C.
name: Bellansantini, D.
name: Bellan, G.
Publisher: name: Station Biologique de Roscoff (SBR)
Year: 1993

description: The concepts of sympatry and allopatry. of syntopy and allotopy. are the basis of the relationship between systematics and ecology. In the Roscoff region (French coasts off the British Channel). Ampelisca (amphipoda) are present in syntopy ; nine species live in the subtidal muddy sands of the Bay of Morlaix. while five species of Ophelia (polychaeta) occur in four distinct intertidal and subtidal biotopes (fine to coarse sands). Differences in reproductive strategies, food preferences or microhabitat requirements (notably ''volume of life''), have often been used to explain such patterns of distribution. However we suggest that an alternative strategy may be one of evolutionary strategies related to population levels. The syntopic distribution of a genus is not a chance level. Dense populations of Ampelisca were wiped out by the oil spill from the ''Amoco Cadiz'' in 1978 but they re-appeared within 10 years of this pollution event, in spite of even though amphipods lack a free swimming larval stage, and the distance of non-perturbed populations of Ampelisca allowing the recolonisation.
Detection of basepair mismatches in DNA using graphene based nanopore device
Creators: name: Kundu, Sourav
name: Karmakar, S. N.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We present an unique way to detect basepair mismatches in DNA leading to different epigenetic disorder by the method of nanopore sequencing. Based on a tight-binding formulation of graphene nanopore based device, using Greens function approach we measure the changes in the electronic transport properties of the device as we translocate a double-stranded DNA through the nanopore embeded in a zigzag graphene nanoribbon. In the present work we not only successfully detect the usual AT and GC pairs, but also a set of possible mismatches in the complementary base-pairing without any ambiguity. Our investigation shows that this device can also be used for reliable sequential detection of other biomolecules.
description: Accepted in Nanotechnology, 12 pages, 7 figures
An information criterion for marginal structural models
Creators: name: Brookhart, M. Alan
name: Platt, Robert W.
name: Westreich, Daniel
name: Cole, Stephen R.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2013

description: Marginal structural models were developed as a semiparametric alternative to the G-computation formula to estimate causal effects of exposures. In practice, these models are often specified using parametric regression models. As such, the usual conventions regarding regression model specification apply. This paper outlines strategies for marginal structural model specification, and considerations for the functional form of the exposure metric in the final structural model. We propose a quasi-likelihood information criterion adapted from use in generalized estimating equations. We evaluate the properties of our proposed information criterion using a limited simulation study. We illustrate our approach using two empirical examples. In the first example, we use data from a randomized breastfeeding promotion trial to estimate the effect of breastfeeding duration on infant weight at one year. In the second example, we use data from two prospective cohorts studies to estimate the effect of highly active antiretroviral therapy on CD4 count in an observational cohort of HIV-infected men and women. The marginal structural model specified should reflect the scientific question being addressed, but can also assist in exploration of other plausible and closely related questions. In marginal structural models, as in any regression setting, correct inference depends on correct model specification. Our proposed information criterion provides a formal method for comparing model fit for different specifications.
Concentration of pathogenic bacteria and trace metals in bivalve mollusk Anadara granosa (Bivalvia: Arcidae) harvested from East Java Coast, Indonesia
Creators: name: SOEGIANTO, Agoes
name: SUPRIYANTO, Agus
Publisher: name: Station Biologique de Roscoff (SBR)
Year: 2008

description: A study to evaluate the level of Escherichia coli, Salmonella and trace metals in bivalves Anadara granosa col-
 lected from East Java Coast has been conducted. The results showed that all stations demonstrated undetectable values of
 Salmonella in bivalve tissues. In contrast, the Escherichia coli values in bivalves ranged from undetectable level to 4800
 MPN.100 g-1. Measurement for lead of all samples of bivalves from all sampling sites was always below the detection limit
 of 0.0405 mg.kg-1. The concentrations of cadmium in bivalves highly varied from 1.234 to 2.404 mg.kg-1, and mercury
 levels were between < 0.0014 and 0.048 mg.kg-1. Escherichia coli level in bivalves from some locations evaluated
 exceeded the acceptable limit for shellfish for human consumption. This study reported that the concentrations of lead and
 mercury in Anadara granosa was below the range acceptable for consumption. However, the concentrations of cadmium
 in bivalves harvested from some locations of East Java Coast were higher than the maximum acceptable limit for
 consumption.
Elisabetta Fiorini ved. Mazzanti a Luigi Ridolfi (22 giugno 1852)
Creators: name: Fiorini Mazzanti, Elisabetta
name: Ridolfi, Luigi
Publisher: name: Zenodo
Year: 2023
Subjects: Accademia dei Georgofili
Fiorini Mazzanti, Elisabetta
Ridolfi, Luigi
Lettera
Letter
Carteggio
Correspondence
Donne
Scienziate
Pregiudizi
1852

description: Lettera di ringraziamento di Elisabetta Fiorini Mazzanti a Luigi Ridolfi per la nomina ad accademico corrispondente del 22 giugno 1852. Segnatura dell’unità documentale: Archivio storico dell’Accademia dei Georgofili, Carteggio, Busta 31, 2769. Natura: manoscritto. Consistenza: cc. 2
description: Digitalizzato come parte della Mostra virtuale: Riconoscere il merito, superare i pregiudizi: scienziate ai Georgofili (1753-1911). https://www.georgofili.it/contenuti/riconoscere-il-merito-superare-i-pregiudizi-scienziate-ai-georgofili-1753-1911-mostra-in-rete/11369
Digital Scholarship at the Koninklijke Bibliotheek
Creators: name: Wilms, Lotte
name: Claeyssens, Steven
Publisher: name: Zenodo
Year: 2015
Subjects: digital scholarship
digital humanities
cultural heritage
kb lab

description: The National Library of the Netherlands (KB) is an active partner in national and international cooperative efforts to develop new knowledge and technology. With this poster, we wish to showcase what the KB can offer researchers in the field of Digital Humanities. We will present our digitised data sets, current research projects and the services of the KB Research Lab that was launched at DHBenelux 2014. The KB has planned to have digitised and OCRed its entire collection of books, periodicals and newspapers from 1470 onward by the year 2030. Already in 2013, 10% of this enormous task was completed, resulting in 73 million digitised pages, either from the KB itself or via public-private partnerships as Google Books and ProQuest. Over 1 million books, newspapers and magazines are currently available via the search portal www.delpher.nl. Next to this, most of these data sets are freely available for research purposes and we welcome and encourage experiments and new applications. The virtual KB Research Lab shows some of such applications and invites researchers to experiment with our data, new technologies and innovative prototypes. The KB also collaborates with researchers in research projects or (junior) fellowships to learn from their research in order to improve the services we provide for Digital Humanists. This poster will present the various data sets that the KB has available for research, the activities we undertake to work together with scholars in research projects and the services that we offer those who wish to work with our material.
description: Abstract also available here; http://dhbenelux.org/wp-content/uploads/2015/04/08.pdf
Supplemental Material from Rapid and positive responses of plants to lower precipitation predictability
Creators: name: Martí March-Salas
name: Kleunen, Mark Van
name: Fitze, Patrick S.
Publisher: name: The Royal Society
Year: 2019
Subjects: subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: Environmental Science
subject: Ecology

description: Current climate change is characterized by an increase in weather variability, which includes altered means, variance and predictability of weather parameters, and which may affect an organism's ecology and evolution. Few studies experimentally manipulated the variability of weather parameters, and very little is known about the effects of changes in the intrinsic predictability of weather parameters on living organisms. Here, we experimentally tested the effects of differences in intrinsic precipitation-predictability on two herbaceous plants (Onobrychis viciifolia and Papaver rhoeas). Lower precipitation-predictability led to phenological advance and to an increase in reproductive success, and population growth. Both species exhibited rapid transgenerational responses in phenology and fitness-related traits across four generations that mitigated most effects of precipitation-predictability on fitness proxies of ancestors. Transgenerational responses appeared to be the result of changes in phenotypic plasticity rather than local adaptation. They mainly existed with respect to conditions prevailing during early, but not during late growth, suggesting that responses to differences in predictability during late growth might be more difficult. The results show that lower short-term predictability of precipitation positively affected fitness, rapid transgenerational responses existed and different time scales of predictability (short-term, seasonal and transgenerational predictability) may affect organisms differently. This shows that the time scale of predictability should be considered in evolutionary and ecological theories, and in assessments of the consequences of climate change.
TEMPORAL DYNAMICS AND SECONDARY PRODUCTION OF MELINNA-PALMATA GRUBE, 1870 IN THE BAY OF SANTANDER (NORTHERN SPAIN)
Creators: name: Lastra, M.
name: Sanchezmata, A.
name: Palacio, J.
name: Mora, J.
Publisher: name: Station Biologique de Roscoff (SBR)
Year: 1993

description: A Melinna palmata population, settled on sedimentologically stable bottoms rich in silt and clay fraction and organic matter, has been studied in Santander Bay. The population dynamics was studied in terms of a bimodal cohort that receives juvenils continously between april and november. An AFDW production of 2,92 gr/m2 . year and a P/B ratio of 2,86 was found. The therorical growth rate, obtained from animal maximum size, set a lifespan of 2,5 years. Temporal dynamics of this species (biomass and density) shows high variability.
Are Gestational Age, Birth Weight, and Birth Length Indicators of Favorable Fetal Growth Conditions? A Structural Equation Analysis of Filipino Infants
Creators: name: Noble, Mark D.
name: Adair, Linda S.
name: Bollen, Kenneth A.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2013

description: The fetal origin hypothesis emphasizes the life-long health impacts of prenatal conditions. Birth weight, birth length, and gestational age are indicators of the fetal environment. However, these variables often have missing data and are subject to random and systematic errors caused by delays in measurement, differences in measurement instruments, and human error. With data from the Cebu (Philippines) Longitudinal Health and Nutrition Survey, we use structural equation models (SEMs), to explore random and systematic errors in these birth outcome measures, to analyze how maternal characteristics relate to birth outcomes, and to take account of missing data. We assess whether birth weight, birth length, and gestational age are influenced by a single latent variable that we call Favorable Fetal Growth Conditions (FFGC) and if so, which variable is most closely related to FFGC. We find that a model with FFGC as a latent variable fits as well as a less parsimonious model that has birth weight, birth length, and gestational age as distinct individual variables. We also demonstrate that birth weight is more reliably measured than is gestational age. FFGC were significantly influenced by taller maternal stature, better nutritional stores indexed by maternal arm fat and muscle area during pregnancy, higher birth order, avoidance of smoking and maternal age 20-35 years. Effects of maternal characteristics on newborn weight, length and gestational age were largely indirect, operating through FFCG.
Bayesian inference for multivariate meta-analysis Box-Cox transformation models for individual patient data with applications to evaluation of cholesterol-lowering drugs
Creators: name: Shah, Arvind K.
name: Chen, Ming-Hui
name: Kim, Sungduk
name: Ibrahim, Joseph G.
name: Lin, Jianxin
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2013

description: In this paper, we propose a class of Box-Cox transformation regression models with multidimensional random effects for analyzing multivariate responses for individual patient data (IPD) in meta-analysis. Our modeling formulation uses a multivariate normal response meta-analysis model with multivariate random effects, in which each response is allowed to have its own Box-Cox transformation. Prior distributions are specified for the Box-Cox transformation parameters as well as the regression coefficients in this complex model, and the Deviance Information Criterion (DIC) is used to select the best transformation model. Since the model is quite complex, a novel Monte Carlo Markov chain (MCMC) sampling scheme is developed to sample from the joint posterior of the parameters. This model is motivated by a very rich dataset comprising 26 clinical trials involving cholesterol lowering drugs where the goal is to jointly model the three dimensional response consisting of Low Density Lipoprotein Cholesterol (LDL-C), High Density Lipoprotein Cholesterol (HDL-C), and Triglycerides (TG) (LDL-C, HDL-C, TG). Since the joint distribution of (LDL-C, HDL-C, TG) is not multivariate normal and in fact quite skewed, a Box-Cox transformation is needed to achieve normality. In the clinical literature, these three variables are usually analyzed univariately: however, a multivariate approach would be more appropriate since these variables are correlated with each other. A detailed analysis of these data is carried out using the proposed methodology.
Bayesian modeling and inference for clinical trials with partial retrieved data following dropout
Creators: name: Chen, Ming-Hui
name: Chen, Qingxia
name: Ohlssen, David
name: Ibrahim, Joseph G.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2013

description: In randomized clinical trials, it is common that patients may stop taking their assigned treatments and then switch to a standard treatment (standard of care available to the patient) but not the treatments under investigation. While the availability of limited retrieved data on patients who switch to standard treatment, called off-protocol data, could be highly valuable in assessing the associated treatment effect with the experimental therapy, it leads to a complex data structure requiring the development of models that link the information of per-protocol data with the off-protocol data. In this paper, we develop a novel Bayesian method to jointly model longitudinal treatment measurements under various dropout scenarios. Specifically, we propose a multivariate normal mixed-effects model for repeated measurements from the assigned treatments and the standard treatment, a multivariate logistic regression model for those stopping the assigned treatments, logistic regression models for those starting a standard treatment off protocol, and a conditional multivariate logistic regression model for completely withdrawing from the study. We assume that withdrawing from the study is non-ignorable but intermittent missingness is assumed to be at random. Various properties of the proposed model are examined. An efficient Markov chain Monte Carlo sampling algorithm is developed. A real data set from a clinical trial is analyzed in detail via the proposed method.
Change-point models to estimate the limit of detection
Creators: name: May, Ryan C.
name: Hudgens, Michael G.
name: Chu, Haitao
name: Lees, Abigail C.
name: Ibrahim, Joseph G.
name: Margolis, David M.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2013

description: In many biological and environmental studies, measured data is subject to a limit of detection. The limit of detection is generally defined as the lowest concentration of analyte that can be differentiated from a blank sample with some certainty. Data falling below the limit of detection is left-censored, falling below a level that is easily quantified by a measuring device. A great deal of interest lies in estimating the limit of detection for a particular measurement device. In this paper we propose a change-point model to estimate the limit of detection using data from an experiment with known analyte concentrations. Estimation of the limit of detection proceeds by a two-stage maximum likelihood method. Extensions are considered that allow for censored measurements and data from multiple experiments. A simulation study is conducted demonstrating that in some settings the change-point model provides less biased estimates of the limit of detection than conventional methods. The proposed method is then applied to data from an HIV pilot study.
Kappa statistic for clustered dichotomous responses from physicians and patients
Creators: name: Cai, Jianwen
name: Sheridan, Stacey L.
name: Kang, Chaeryon
name: Monaco, Jane
name: Qaqish, Bahjat
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2013

description: The bootstrap method for estimating the standard error of the kappa statistic in the presence of clustered data is evaluated. Such data arise, for example, in assessing agreement between physicians and their patients regarding their understanding of the physician-patient interaction and discussions. We propose a computationally efficient procedure for generating correlated dichotomous responses for physicians and assigned patients for simulation studies. The simulation result demonstrates that the proposed bootstrap method produces better estimate of the standard error and better coverage performance compared to the asymptotic standard error estimate that ignores dependence among patients within physicians with at least a moderately large number of clusters. An example of an application to a coronary heart disease prevention study is presented.
Sample size estimation in educational intervention trials with subgroup heterogeneity in only one arm
Creators: name: Cai, Jianwen
name: Zhao, Yingqi
name: Esserman, Denise
name: Tang, Yiyun
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2013

description: We present closed form sample size and power formulas motivated by the study of a psycho-social intervention in which the experimental group has the intervention delivered in teaching subgroups while the control group receives usual care. This situation is different from the usual clustered randomized trial since subgroup heterogeneity only exists in one arm. We take this modification into consideration and present formulas for the situation in which we compare a continuous outcome at both a single point in time and longitudinally over time. In addition, we present the optimal combination of parameters such as the number of subgroups and number of time points for minimizing sample size and maximizing power subject to constraints such as the maximum number of measurements that can be taken (i.e. a proxy for cost).
Leaders do not look back, or do they?
Creators: name: Gorban, Alexander N.
name: Jarman, Nick
name: Steur, Erik
name: van Leeuwen, Cees
name: Tyukin, Ivan
Publisher: name: arXiv
Year: 2015
Subjects: subject: Dynamical Systems (math.DS)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 34A30, 34D06, 34D45, 92B20, 92B25

description: We study the effect of adding to a directed chain of interconnected systems a directed feedback from the last element in the chain to the first. The problem is closely related to the fundamental question of how a change in network topology may influence the behavior of coupled systems. We begin the analysis by investigating a simple linear system. The matrix that specifies the system dynamics is the transpose of the network Laplacian matrix, which codes the connectivity of the network. Our analysis shows that for any nonzero complex eigenvalue $λ$ of this matrix, the following inequality holds: $\frac{|\Im λ|}{|\Re λ|} \leq \cot\fracπ{n}$. This bound is sharp, as it becomes an equality for an eigenvalue of a simple directed cycle with uniform interaction weights. The latter has the slowest decay of oscillations among all other network configurations with the same number of states. The result is generalized to directed rings and chains of identical nonlinear oscillators. For directed rings, a lower bound $σ_c$ for the connection strengths that guarantees asymptotic synchronization is found to follow a similar pattern: $σ_c=\frac{1}{1-\cos\left( 2π/n\right)} $. Numerical analysis revealed that, depending on the network size $n$, multiple dynamic regimes co-exist in the state space of the system. In addition to the fully synchronous state a rotating wave solution occurs. The effect is observed in networks exceeding a certain critical size. The emergence of a rotating wave highlights the importance of long chains and loops in networks of oscillators: the larger the size of chains and loops, the more sensitive the network dynamics becomes to removal or addition of a single connection.
A marginalized zero-inflated Poisson regression model with overall exposure effects
Creators: name: Preisser, John S.
name: Long, D. Leann
name: Herring, Amy H.
name: Golin, Carol E.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: The zero-inflated Poisson (ZIP) regression model is often employed in public health research to examine the relationships between exposures of interest and a count outcome exhibiting many zeros, in excess of the amount expected under sampling from a Poisson distribution. The regression coefficients of the ZIP model have latent class interpretations, which correspond to a susceptible subpopulation at risk for the condition with counts generated from a Poisson distribution and a non-susceptible subpopulation that provide the extra or excess zeros. The ZIP model parameters, however, are not well suited for inference targeted at marginal means, specifically, in quantifying the effect of an explanatory variable in the overall mixture population. We develop a marginalized ZIP model approach for independent responses to model the population mean count directly, allowing straightforward inference for overall exposure effects and empirical robust variance estimation for overall log incidence density ratios. Through simulation studies, the performance of maximum likelihood estimation of the marginalized ZIP model is assessed and compared to other methods of estimating overall exposure effects. The marginalized ZIP model is applied to a recent study of a motivational interviewing-based safer sex counseling intervention, designed to reduce unprotected sexual act counts.
On an integrable magnetic geodesic flow on the two-torus
Creators: name: Taimanov, I. A.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Dynamical Systems (math.DS)
subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics

description: We completely integrate the magnetic geodesic flow on a flat two-torus with the magnetic field $F = \cos (x) dx \wedge dy$ and describe all contractible periodic magnetic geodesics. It is shown that there are no such geodesics for energy $E \geq 1/2$, for $E< 1/2$ simple periodic magnetic geodesics form two $S^1$-families for which the (fixed energy) action functional is positive and therefore there are no periodic magnetic geodesics for which the action functional is negative.
description: 18 pages
Assessing model fit in joint models of longitudinal and survival data with applications to cancer clinical trials
Creators: name: Chen, Ming-Hui
name: Boye, Mark E.
name: Wang, Ping
name: Zhang, Danjie
name: Shen, Wei
name: Ibrahim, Joseph G.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: Joint models for longitudinaland survival data now have along history of being used in clinical trials or other studies in which the goal is to assess a treatment effect while accounting for longitudinal assessments such as patient-reported outcomes or tumor response. Compared to using survival data alone,the joint modeling of survival and longitudinal data allows for estimation of direct and indirect treatment effects, thereby resulting in improved efficacy assessment. Although global fit indices such as AIC or BIC can be used to rank joint models, these measures do not provide separate assessments of each component of the joint model. In this paper, we develop a novel decomposition of AIC and BIC (i.e., AIC = AICLong + AICSurv|Long and BIC = BICLong + BICSurv|Long) that allows us to assess the fit of each component of the joint model, and in particular to assess the fit of the longitudinal component of the model and the survival component separately. Based on this decomposition, we then propose ΔAICSurv and ΔBICSurv to determine the importance and contribution of the longitudinal data to the model fit of the survival data. Moreover, this decomposition, along with ΔAICSurv and ΔBICSurv, is also quite useful in comparing, for example, trajectory-based joint models and shared parameter joint models and deciding which type of model best fits the survival data. We examine a detailed case study in mesothelioma to apply our proposed methodology along with an extensive set of simulation studies.
Bayesian sequential meta-analysis design in evaluating cardiovascular risk in a new antidiabetic drug development program: Bayesian Meta-experimental Design
Creators: name: Amy Xia, H.
name: Chen, Ming-Hui
name: Ibrahim, Joseph G.
name: Hennessey, Violeta
name: Liu, Thomas
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: Recently, the Center for Drug Evaluation and Research at the Food and Drug Administration (FDA) released a guidance that makes recommendations about how to demonstrate that a new antidiabetic therapy to treat Type 2 diabetes is not associated with an unacceptable increase in cardiovascular risk. One of the recommendations from the guidance is that Phase II and III trials should be appropriately designed and conducted so that a meta-analysis can be performed. In addition, the guidance implies that a sequential meta-analysis strategy could be adopted. That is, the initial meta-analysis could aim at demonstrating the upper bound of a 95% confidence interval (CI) for the estimated hazard ratio to be < 1.8 for the purpose of enabling a new drug application (NDA) or a biologics license application (BLA). Subsequently after the marketing authorization, a final meta-analysis would need to show the upper bound to be < 1.3. In this context, we develop a new Bayesian sequential meta-analysis approach using survival regression models to assess whether the size of a clinical development program is adequate to evaluate a particular safety endpoint. We propose a Bayesian sample size determination methodology for sequential meta-analysis clinical trial design with a focus on controlling the familywise Type I error rate and power. The partial borrowing power prior is used to incorporate the historical survival meta-data into the Bayesian design. Various properties of the proposed methodology are examined and simulation-based computational algorithms are developed to generate predictive data at various interim analyses, sample from the posterior distributions, and compute various quantities such as the power and the Type I error in the Bayesian sequential meta-analysis trial design. The proposed methodology is applied to the design of a hypothetical antidiabetic drug development program for evaluating cardiovascular risk.
T-matrix in discrete oscillator representation
Creators: name: Vasilevsky, V. S.
name: Soloha-Klymchak, M. D.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Nuclear Theory (nucl-th)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate T-matrix for bound and continuous-spectrum states in the discrete oscillator representation. The investigation is carried out for a model problem - the particle in the field of a central potential. A system of linear equations is derived to determine the coefficients of the T-matrix expansion in the oscillator functions. We selected four potentials (Gaussian, exponential, Yukawa, and square-well ones) to demonstrate peculiarities of the T-matrix and its dependence on the potential shape. We also study how the T-matrix expansion coefficients depend on the parameters of the oscillator basis such as the oscillator length and the number of basis functions involved in calculations.
description: 12 pages, 12 figures, UJP style file provided
Pairing of Fermions with Unequal Effective Charges in an Artificial Magnetic Field
Creators: name: Ünal, F. Nur
name: Oktel, M. Ö.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Artificial magnetic fields (AMFs) created for ultra cold systems depend sensitively on the internal structure of the atoms. In a mixture, each component experiences a different AMF depending on its internal state. This enables the study of Bardeen-Cooper-Schrieffer pairing of fermions with unequal effective charges. In this Letter, we investigate the superconducting (SC) transition of a system formed by such pairs as a function of field strength. We consider a homogeneous two-component Fermi gas of unequal effective charges but equal densities with attractive interactions. We find that the phase diagram is altered drastically compared to the usual balanced charge case. First, for some AMFs there is no SC transition and isolated SC phases are formed, reflecting the discrete Landau level (LL) structure. SC phases become reentrant both in AMF and temperature. For extremely high fields where both components are confined to their lowest LLs, the effect of the charge imbalance is suppressed. Charge asymmetry reduces the critical temperature even in the low-field semiclassical regime. We discuss a pair breaking mechanism due to the unequal Lorentz forces acting on the components of the Cooper pairs to identify the underlying physics.
description: 5 pages, 2 figures, the version published in PRL
Paul Malone - Cutting Dollfuss Up To Size: Political Cartooning and the Rise of Austro-Fascism
Creators: name: Malone, Paul
Publisher: name: University of the Arts London
Year: 2020
Subjects: subject: 199999 Studies in the Creative Arts and Writing not elsewhere classified
subject: FOS: Arts (arts, history of arts, performing arts, music)

description: Cutting Dollfuss Up To Size: Political Cartooning and the Rise of Austro-Fascism
 Between the World Wars, Vienna’s newspapers stretched across the political spectrum; many regularly contained biting political cartoons. By the early 1930s, such cartoons focussed on Dr. Engelbert Dollfuss, who quickly rose within the conservative Christian Social Party to the Chancellorship in May 1932. Left-wing papers were particularly critical of Dollfuss, whose conservative-nationalist-fascist coalition had such a razor-thin majority that he was increasingly forced to work against parliament in order to enforce austerity measures to cope with the Depression. Because Dollfuss stood less than five feet tall, it was common to caricature him as a tiny, infantilized incompetent. The situation changed in March 1933, however, when Dollfuss found an excuse to sideline parliament and rule by decree; and even more following the four-day civil war of February 1934, when he abolished political parties and established a dictatorship. Those papers that were not closed down or nationalized came to terms, and portrayals of Dollfuss became more positive: now he became first an adult-sized champion of social justice against German Nazism, and then an assassinated martyr for the Austrian cause. The developments in the depiction of Dollfuss echo the contemporary increasing constraints on democracy and the propagandization of the media in the last years of the republic.
Joint modeling of longitudinal and survival data with missing and left-censored time-varying covariates
Creators: name: May, Ryan C.
name: Cole, Stephen R.
name: Ibrahim, Joseph G.
name: Chu, Haitao
name: Chen, Qingxia
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2014

description: We propose a joint model for longitudinal and survival data with time-varying covariates subject to detection limits and intermittent missingness at random (MAR). The model is motivated by data from the Multicenter AIDS Cohort Study (MACS), in which HIV+ subjects have viral load and CD4 cell count measured at repeated visits along with survival data. We model the longitudinal component using a normal linear mixed model, modeling the trajectory of CD4 cell count by regressing on viral load and other covariates. The viral load data are subject to both left-censoring due to detection limits (17%) and intermittent missingness (27%). The survival component of the joint model is a Cox model with time-dependent covariates for death due to AIDS. The longitudinal and survival models are linked using the trajectory function of the linear mixed model. A Bayesian analysis is conducted on the MACS data using the proposed joint model. The proposed method is shown to improve the precision of estimates when compared to alternative methods.
Review of Poeobius meseres Heath, 1930 (Polychaeta: Flabelligeridae)
Creators: name: SALAZAR-VALLEJO, Sergio I.
Publisher: name: Station Biologique de Roscoff (SBR)
Year: 2008

description: The taxonomic position of the holopelagic polychaete Poeobius meseres Heath, 1930 has shifted from being an
 independent family or order, towards becoming a member of the Flabelligeridae by using molecular methods. There are a
 series of problems about the morphological features for the species and genus, and all materials available were studied
 trying to improve our understanding of their taxonomic placement. There seems to be at least two morphological patterns
 regarding the arrangement of branchial filaments and in the relative rugosity of the tunic and egg size. The holotype can-
 not be employed to solve this because it has its anterior end invaginated; consequently, it is suggested to make additional
 collections and redescriptions based upon better materials to clarify this problem.