Since antiquity, the she-wolf has served as the potent symbol of Rome. For more than two thousand years, the legendary animal that rescued Romulus and Remus has been the subject of historical and ...political accounts, literary treatments in poetry and prose, and visual representations in every medium. In She-Wolf: The Story of a Roman Icon, Cristina Mazzoni examines the evolution of the she-wolf as a symbol in western history, art, and literature, from antiquity to contemporary times. Used, for example, as an icon of Roman imperial power, papal authority, and the distance between the present and the past, the she-wolf has also served as an allegory for greed, good politics, excessive female sexuality, and, most recently, modern, multi-cultural Rome. Mazzoni engagingly analyzes the various role guises of the she-wolf over time in the first comprehensive study in any language on this subject.
This paper proposes an innovative tuning approach for fuzzy control systems (CSs) with a reduced parametric sensitivity using the Grey Wolf Optimizer (GWO) algorithm. The CSs consist of servo system ...processes controlled by Takagi-Sugeno-Kang proportional-integral fuzzy controllers (TSK PI-FCs). The process models have second-order dynamics with an integral component, variable parameters, a saturation, and dead-zone static nonlinearity. The sensitivity analysis employs output sensitivity functions of the sensitivity models defined with respect to the parametric variations of the processes. The GWO algorithm is used in solving the optimization problems, where the objective functions include the output sensitivity functions. GWO's motivation is based on its low-computational cost. The tuning approach is validated in an experimental case study of a position control for a laboratory nonlinear servo system, and TSK PI-FCs with a reduced process small time constant sensitivity are offered.
Long-standing myths exist about the origins of wolf–coyote hybrids and related Canis species in Ontario. Specifically, there is a perceived controversy whether they are the product of natural ...hybridization that occurred between wolves and coyotes in the wild during the last century or the descendants of animals that escaped or were released from captive colonies or controlled breeding experiments. We review the relevant evidence and conclude that captive colonies and controlled breeding experiments were unlikely to have played any role in the origins of wolf–coyote hybrids and related Canis species in Ontario.
ABSTRACT We present a new empirical prescription for the mass-loss rates of carbon- and oxygen-sequence Wolf-Rayet stars as a function of their luminosity, surface chemical composition, and initial ...metallicity. The new prescription is based on results of detailed spectral analyses of WC and WO stars and improves the often applied Nugis and Lamers relation. We find that the mass-loss rates of WC and WO stars (with X = 0 and Y 0.98) can be expressed as (L/L ) + 0.44 log Y + 0.25 log (ZFe/ZFe, ). This relation is based on mass-loss determinations that assume a volume-filling factor of 0.1, but the prescription can easily be scaled to account for other volume-filling factors. The residual of the fit is = 0.06 dex. We investigated whether the relation can also describe the mass loss of hydrogen-free WN stars and showed that it can when an adjustment of the metallicity dependence ( ) is applied. Compared to that of Nugis and Lamers, is less sensitive to the luminosity and the surface abundance, implying a stronger mass loss of massive stars in their late stages of evolution. The modest metallicity dependence implies that if WC or WO stars are formed in metal-deficient environments, their mass-loss rates are higher than currently anticipated. These effects may result in the formation of a larger number of SNe Ic and fewer black holes and may favor the production of superluminous SNe Ic through interaction with C- and O-rich circumstellar material or dense stellar wind.
The grey wolf (
Canis lupus
) is one of the most widely distributed mammals in which a variety of distinct populations have been described. However, given their currently fragmented distribution and ...recent history of human-induced population decline, little is known about the events that led to their differentiation. Based on the analysis of whole canid genomes, we examined the divergence times between Southern European wolf populations and their ancient demographic history. We found that all present-day Eurasian wolves share a common ancestor
ca
36 000 years ago, supporting the hypothesis that all extant wolves derive from a single population that subsequently expanded after the Last Glacial Maximum. We also estimated that the currently isolated European populations of the Iberian Peninsula, Italy and the Dinarics-Balkans diverged very closely in time,
ca
10 500 years ago, and maintained negligible gene flow ever since. This indicates that the current genetic and morphological distinctiveness of Iberian and Italian wolves can be attributed to their isolation dating back to the end of the Pleistocene, predating the recent human-induced extinction of wolves in Central Europe by several millennia.
Context. It is now well established that the majority of massive stars reside in multiple systems. However, the effect of multiplicity is not sufficiently understood, resulting in a plethora of ...uncertainties about the end stages of massive-star evolution. In order to investigate these uncertainties, it is useful to study massive stars just before their demise. Classical Wolf-Rayet stars represent the final end stages of stars at the upper-mass end. The multiplicity fraction of these stars was reported to be ∼0.4 in the Galaxy but no correction for observational biases has been attempted. Aims. The aim of this study is to conduct a homogeneous radial-velocity survey of a magnitude-limited (V ≤ 12) sample of Galactic Wolf-Rayet stars to derive their bias-corrected multiplicity properties. The present paper focuses on 12 northern Galactic carbon-rich (WC) Wolf-Rayet stars observable with the 1.2 m Mercator telescope on the island of La Palma. Methods. We homogeneously measured relative radial velocities (RVs) for carbon-rich Wolf-Rayet stars using cross-correlation. Variations in the derived RVs were used to flag binary candidates. We investigated probable orbital configurations and provide a first correction of observational biases through Monte-Carlo simulations. Results. Of the 12 northern Galactic WC stars in our sample, seven show peak-to-peak RV variations larger than 10 km s−1, which we adopt as our detection threshold. This results in an observed spectroscopic multiplicity fraction of 0.58 with a binomial error of 0.14. In our campaign, we find a clear lack of short-period (P < ∼100 d), indicating that a large number of Galactic WC binaries likely reside in long-period systems. Finally, our simulations show that at the 10% significance level, the intrinsic multiplicity fraction of the Galactic WC population is at least 0.72.
Wolf-Hirschhorn syndrome (WHS) is a developmental disorder attributed to a partial deletion on the short arm of chromosome 4. WHS patients suffer from oral manifestations including cleft lip and ...palate (CLP), hypodontia, and taurodontism. Wolf-Hirschhorn syndrome candidate 1 gene (WHSC1) is a H3K36-specific methyltransferase that is deleted in every reported case of WHS. Mutation in this gene also results in tooth anomalies in patients. However, the correlation between genetic abnormalities and the tooth anomalies has remained controversial. In our study, we aimed to clarify the role of WHSC1 in tooth development. We profiled the Whsc1 expression pattern during mouse incisor and molar development by immunofluorescence staining and found Whsc1 expression is reduced as tooth development proceeds. Using RT-qPCR, Western blot, ChIP and luciferase assays, we determined that Whsc1 and Pitx2, the initial transcription factor involved in tooth development, positively and reciprocally regulate each other through their gene promoters. MicroRNAs are known to regulate gene expression post-transcriptionally during development. We previously reported miR-23a/b and miR-24-1/2 were highly expressed in the mature tooth germ. Interestingly, we demonstrate here that these two miRs directly target Whsc1 and repress its expression. Additionally, this miR cluster is also negatively regulated by Pitx2. We show the expression of these two miRs and Whsc1 are inversely correlated during mouse mandibular development. Taken together, our results provide new insights into the potential role of Whsc1 in regulating tooth development and a possible molecular mechanism underlying the dental defects in WHS.
Since Hirschhorn's description in 1961, the history and chronology of the clinical, cytogenetic, and molecular characterization of Wolf-Hirschhorn syndrome (WHS) elegantly demonstrates the remarkable ...advances in genetic technology over the last six decades that have paralleled the delineation of the phenotype. After mention in the Human Chromosome Newsletter of a child with a visible deletion of the top of a B chromosome group, 4-5, Hirschhorn and colleagues companioned their report with that of Wolf et al. in Humangenetik in 1965, and the condition was recognized and named. The 1960-1970s witnessed the description of many of the now classic chromosome disorders, including WHS, while HRB allowed for the recognition of chromosome syndromes with smaller deletions/duplications. FISH probes, developed in the next two decades, enabled the characterization of the critical region of WHS and improved clinical diagnosis with subtelomeric probes. Cytogenomic microarray in the early-mid 2000s led to both improved diagnosis of WHS patients and documentation of microdeletions of <5 megabases, helping to characterize the critical regions for specific component phenotypes (e.g., seizures, face). Recently exome sequencing technology has led to the discovery of WHS patients with WHSC1 loss of function variants, displaying some cardinal features of the phenotype (face, growth, and developmental delay).
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