bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Comparison of Methods for Estimating the Determinant of High-Dimensional Covariance Matrix
Authors: Hu Zongliang , Dong Kai , Dai Wenlin , Tong Tiejun 
Published: September 2017

Abstract
The determinant of the covariance matrix for high-dimensional data plays an important role in statistical inference and decision. It has many real applications including statistical tests and information theory. Due to the statistical and computational challenges with high dimensionality, little work has been proposed in the literature for estimating the determinant of high-dimensional covariance matrix. In this paper, we estimate the determinant of the covariance matrix using some recent proposals for estimating high-dimensional covariance matrix. Specifically, we consider a total of eight covariance matrix estimation methods for comparison. Through extensive simulation studies, we explore and summarize some interesting comparison results among all compared methods. We also provide practical guidelines based on the sample size, the dimension, and the correlation of the data set for estimating the determinant of high-dimensional covariance matrix. Finally, from a perspective of the loss function, the comparison study in this paper may also serve as a proxy to assess the performance of the covariance matrix estimation.
A Linear “Microscope” for Interventions and Counterfactuals
Authors: Pearl Judea 
Published: September 2017

Abstract
This note illustrates, using simple examples, how causal questions of non-trivial character can be represented, analyzed and solved using linear analysis and path diagrams. By producing closed form solutions, linear analysis allows for swift assessment of how various features of the model impact the questions under investigation. We discuss conditions for identifying total and direct effects, representation and identification of counterfactual expressions, robustness to model misspecification, and generalization across populations.
Variability in /s/ among transgender speakers: Evidence for a socially grounded account of gender and sibilants
Authors: Zimman Lal 
Published: September 2017

AbstractSibilant consonants are well-established as resources for the negotiation of gender and sexuality, but the origin of these links is less clearly agreed upon. Some researchers have pointed to sex differentiation in the vocal anatomy as a potential cause for gender differences in /s/, though a review of the literature indicates that learned articulatory patterns play a critical role. This article focuses on the spectral qualities of /s/ among 15 English-speaking transgender men and transmasculine individuals. Because their early socialization and physiological development is not normatively aligned with their self-defined gender identities, trans people are well-positioned to illuminate the relative contribution of physiology and identity to the gendered voice. Two analyses are presented, one of which focuses on inter-speaker variation among all 15 participants, and the other of which compares one bilingual speaker’s productions of /s/ in English and Spanish. Together, these analyses demonstrate that sex category does not determine the gender-linked acoustic characteristics of /s/. Instead, a more complex, multidimensional framework for gender that distinguishes between gender assignment, role, identity, and presentation is necessary to account for the full range of gendered phonetic styles that speakers can employ and hence to understand the process through which gendered voices arise.
On the influence of coronal sibilants and stops on the perception of social meanings in Copenhagen Danish
Authors: Pharao Nicolai , Maegaard Marie 
Published: September 2017

AbstractPrevious studies have shown that the same sociolinguistic feature can be used as a sociolinguistic resource with different indexical potentials in different linguistic as well as social contexts. In this paper we present the results of a perceptual study of indexical meanings of fronted and palatalized variants of /t/ in combination with fronted /s/ in different registers of Copenhagen Danish. The data consist of responses to male speakers’ use of the two variants of /t/ in two different registers that we label “modern Copenhagen speech” and “street language.” Results show that the palatalized /t/ affects the indexicality of fronted /s/ with respect to perceived femininity and gayness when it occurs in “modern Copenhagen,” where fronted /s/ has previously been shown to index these traits. However, the variation has a different and less significant effect when occurring in “street language.” Furthermore, the effect is only found in “modern Copenhagen” if the speaker has not previously been heard to produce a fronted /s/. We discuss the implications for theories of the relation between features and clusters of features in listeners’ perceptions.
Tracing the indexicalization of the notion “Helsinki s”
Authors: Halonen Mia , Vaattovaara Johanna 
Published: September 2017

AbstractEarlier research has concluded that there is a strong symbolic relationship between Helsinki as a place and non-standard /s/ pronunciation. This phenomenon is likewise in continuous evidence in the Finnish media and social media. The notion of “Helsinki s” has become a folk linguistic fact although it lacks a clear linguistic correlate or even status as a linguistic fact. The only sibilant of the Finnish language is officially a voiceless alveolar, while the “Helsinki s” is most often discussed as “hissing”, “sharp” or “fronted”. However, according to recent research based on listening tasks, any /s/ may be designated and discussed as a “Helsinki s” if the speaker is regarded as a Helsinki speaker according to other criteria. The present article seeks to trace a development path to illustrate the layered semiotic processes that has led Finnish society to construct “Helsinki s”. In exploring the indexicalization process of this folk notion, the article focuses in particular on the origins and the circumstances under which /s/ pronunciation started to gain social recognition in Finnish society. The ideological link between the socially meaningful /s/ pronunciation and Helsinki is traced back to the early industrialization and urbanization era and (media) discourses of Helsinki in the late 19th century. The present-day associations and the 150-year path of “Helsinki s” are discussed.
On the history of radical-final palatalization in Romanian conjugation: the interaction of phonetic phenomena with non-phonetic
Authors: Elson Mark J. 
Published: September 2017

AbstractThis paper examines the reflexes in Romanian conjugation of Proto-Romance palatalization in radical-final position, i.e., the final consonant of lexical morphemes. It offers an explanation for instances of the absence of the expected reflex, which is relatively frequent in palatalization via the palatal glide as opposed to palatalization via front vowels. It considers both phonetic and non-phonetic factors, including, in its consideration of the present tense, the possibility of Slavic influence, arguing that contact within the Balkan Sprachbund provides an explanation, otherwise unavailable, of the distribution of radical-final palatalization in that paradigm. In view of the likelihood of such influence, it concludes with a general discussion of morphological interference in situations of language contact, a type of interference – as opposed to lexical, derivational, and syntactic interference – which some have questioned.
Assessment of Compaction Quality Based on Two Index Parameters from Roller-Integrated Compaction Measurements
Authors: Nie Z.-H. , Jiao T. , Wang X. , Qiu T. 
Published: September 2017

Abstract
The average degree and uniformity of compaction are two important aspects of continuous compaction control. This paper presents the development and assessment of two new indices for evaluating the average degree and uniformity of field compaction. The proposed index δ accounts for measured compaction values and their corresponding area. The proposed index R relates to the spatial distribution of undercompacted areas. In situ compaction data collected from five subgrade sections are used to assess the applicability of the proposed indices. The results show that the combination of δ and R is capable of comprehensively evaluating field compaction quality. It is found that δ &lt; 1 % and R &gt; 0.5 can be used as the acceptance criteria for average degree of compaction and spatial uniformity of compaction, respectively.
Weak Higher-Order Interactions in Macroscopic Functional Networks of the Resting Brain
Authors: Huang Xuhui , Xu Kaibin , Chu Congying , Jiang Tianzi , Yu Shan 
Published: September 2017

Interactions among different brain regions are usually examined through functional connectivity (FC) analysis, which is exclusively based on measuring pairwise correlations in activities. However, interactions beyond the pairwise level, that is, higher-order interactions (HOIs), are vital in understanding the behavior of many complex systems. So far, whether HOIs exist among brain regions and how they can affect the brain's activities remains largely elusive. To address these issues, here, we analyzed blood oxygenation level-dependent (BOLD) signals recorded from six typical macroscopic functional networks of the brain in 100 human subjects (46 males and 54 females) during the resting state. Through examining the binarized BOLD signals, we found that HOIs within and across individual networks were both very weak regardless of the network size, topology, degree of spatial proximity, spatial scales, and whether the global signal was regressed. To investigate the potential mechanisms underlying the weak HOIs, we analyzed the dynamics of a network model and also found that HOIs were generally weak within a wide range of key parameters provided that the overall dynamic feature of the model was similar to the empirical data and it was operating close to a linear fluctuation regime. Our results suggest that weak HOI may be a general property of brain's macroscopic functional networks, which implies the dominance of pairwise interactions in shaping brain activities at such a scale and warrants the validity of widely used pairwise-based FC approaches.SIGNIFICANCE STATEMENTTo explain how activities of different brain areas are coordinated through interactions is essential to revealing the mechanisms underlying various brain functions. Traditionally, such an interaction structure is commonly studied using pairwise-based functional network analyses. It is unclear whether the interactions beyond the pairwise level (higher-order interactions or HOIs) play any role in this process. Here, we show that HOIs are generally weak in macroscopic brain networks. We also suggest a possible dynamical mechanism that may underlie this phenomenon. These results provide plausible explanation for the effectiveness of widely used pairwise-based approaches in analyzing brain networks. More importantly, it reveals a previously unknown, simple organization of the brain's macroscopic functional systems.
It's easier to get along with the quiet neighbours
Authors: Hurst Laurence D 
Published: September 2017

Why are neighbouring genes co‐expressed at the RNA level? While it is tempting to think that this is to enable coordination of functionally related proteins, analysis of human proteomics data by Rappsilber and colleagues (Kustatscher et al, ) suggests this is the exception not the rule. Rather it might either be just something that happens or, in some instances, an epiphenomenon of coordination of expression to enable reduced gene expression noise.
Adolescencia digitalizada: una mirada desde la pedagogía.
Authors: Mariño Fernández Raquel , Rial Sánchez Antonio 
Published: September 2017

El trabajo que se presenta a continuación surge de la reflexión que desde el Área de la Didáctica y la Pedagogía nos suscitan los resultados aportados por la reciente investigación realizada por las profesoras Delia Crovi (UNAM) y Luz Mª Garay (UPN), México, sobre la juventud universitaria y el uso que hacen de las redes sociales en siete universidades de dicho país. En la investigación Jóvenes y Cultura Digital. Nuevos escenarios de interacción social, se aplicaron 1,548 cuestionarios a estudiantes de educación pública y privada, de nivel medio superior y superior, con el fin de identificar y sistematizar las características de los procesos de interacción, participación y habilidades digitales que despliegan los jóvenes estudiantes al usar redes digitales. A la vista de los resultados obtenidos se arrojan nuevos retos educativos que permitan integrar estas herramientas tecnológicas en las esferas del saber, pero con un enfoque didáctico y pedagógico que nos permita transformar estas competencias digitales en competencias del saber, saber ser, saber hacer y saber estar. O lo que es lo mismo, enseñarles a transformar información en conocimiento
Filamentation Involves Two Overlapping, but Distinct, Programs of Filamentation in the Pathogenic Fungus Candida albicans
Authors: Azadmanesh Jahaun , Gowen Austin M , Creger Paul E , Schafer Nichole D , Blankenship Jill R 
Published: September 2017

Abstract
The ability of the human pathogenic fungus Candida albicans to switch between yeast-like and filamentous forms of growth has long been linked to pathogenesis. Numerous environmental conditions, including growth at high temperatures, nutrient limitation, and exposure to serum, can trigger this morphological switch and are frequently used in in vitro models to identify genes with roles in filamentation. Previous work has suggested that differences exist between the various in vitro models both in the genetic requirements for filamentation and transcriptional responses to distinct filamentation-inducing media, but these differences had not been analyzed in detail. We compared 10 in vitro models for filamentation and found broad genetic and transcriptomic differences between model systems. The comparative analysis enabled the discovery of novel media-independent genetic requirements for filamentation as well as a core filamentation transcriptional profile. Our data also suggest that the physical environment drives distinct programs of filamentation in C. albicans, which has significant implications for filamentation in vivo.
Inference of Distribution of Fitness Effects and Proportion of Adaptive Substitutions from Polymorphism Data
Authors: Tataru Paula , Mollion Maéva , Glémin Sylvain , Bataillon Thomas 
Published: September 2017

Abstract
The distribution of fitness effects (DFE) encompasses the fraction of deleterious, neutral, and beneficial mutations. It conditions the evolutionary trajectory of populations, as well as the rate of adaptive molecular evolution (α). Inferring DFE and α from patterns of polymorphism, as given through the site frequency spectrum (SFS) and divergence data, has been a longstanding goal of evolutionary genetics. A widespread assumption shared by previous inference methods is that beneficial mutations only contribute negligibly to the polymorphism data. Hence, a DFE comprising only deleterious mutations tends to be estimated from SFS data, and α is then predicted by contrasting the SFS with divergence data from an outgroup. We develop a hierarchical probabilistic framework that extends previous methods to infer DFE and α from polymorphism data alone. We use extensive simulations to examine the performance of our method. While an outgroup is still needed to obtain an unfolded SFS, we show that both a DFE, comprising both deleterious and beneficial mutations, and α can be inferred without using divergence data. We also show that not accounting for the contribution of beneficial mutations to polymorphism data leads to substantially biased estimates of the DFE and α. We compare our framework with one of the most widely used inference methods available and apply it on a recently published chimpanzee exome data set.
Las formas de apoyo educativo al estudiantado con discapacidad o con necesidades educativas en la Universidad Nacional de Costa Rica y sus implicaciones en su formación profesional
Authors: Fontana  Hernández Angélica , Vargas Dengo Marie Claire 
Published: September 2017

Este artículo presenta las formas de apoyo educativo a la población estudiantil en condición de discapacidad o con necesidades educativas en el ámbito universitario y sus implicaciones en su formación profesional según los resultados obtenidos en el Proyecto (FIDA) Percepciones y realidades en la atención de las necesidades educativas: propuesta de desarrollo profesional y su implementación en la Universidad Nacional (código 0524-10) del año 2012 al 2015. En este estudio participaron 191 estudiantes (76 hombres y 115 mujeres) matriculados en distintas carreras de las sedes de la UNA (Central, Brunca y Chorotega) y 427 personal académico (181 hombres y 246 mujeres). La metodología responde al enfoque cualitativo y se realizaron 15 talleres con estudiantes y 65 entrevistas individuales para recabar sus apreciaciones. Se determinó que solo una parte del estudiantado recibe atención individual (dentro y fuera de las sesiones de clase) y en ocasiones tutorías (en Inglés, Matemática y Química) por parte del personal académico de la institución en la sede Central. En la evaluación, se les facilita mayor tiempo para la realización de las pruebas e instrucciones individuales durante la misma; asimismo para elaborar trabajos de investigación. Un aspecto que se destaca, es que la mayoría del estudiantado de las Sedes Regionales de la UNA expresó que su opinión no es tomada en cuenta por el personal académico para determinar y aplicar los ajustes en la metodología ni la evaluación de los cursos que imparten. Mientras que en la Sede Central, la mayor parte del grupo conversan con el personal académico para definir por lo menos un tipo ajuste o apoyo educativo.
Anatomical and morphological aspects of papillae, epithelium, muscles, and glands of rats’ tongue: Light, scanning, and transmission electron microscopic study
Authors: Davydova Ludmila , Tkach Gennadii , Tymoshenko Alexey , Moskalenko Alexey , Sikora Vitalii , Kyptenko Ludmila , Lyndin Mykola , Muravskyi Dmytro , Maksymova Olena , Suchonos Olga 
Published: September 2017

Purpose
The purpose of this paper is to describe the research results of the morphological structure of white laboratory rats’ tongue at the macro-, micro-, and ultrastructural levels by scanning, light, and transmission electron microscopy.

Results
Our results show that the tongue of these rats has a number of unique morphological features that are different from the tongue of other rodents consequently to allow identifying their species-specific features.

Conclusions
Our findings have shown the features of the tongue structure of white laboratory rats at micro-, macro-, and ultrascopic levels. The data analysis revealed that mucous membrane of the tongue contains a large number of papillae, such as fungiform, filiform, foliate, vallate, and multifilamentary papillae. Each has a different shape, size, and location. The tongue’s morphological feature consists of three types of filiform papillae, well-developed foliate and multifilamentary papillae, as well as one large and similar smaller circumvallate papillae. The muscle of the tongue contains a large number of mitochondria of different shapes and sizes. However, we have received data for a complete picture of structure of this organ that will be useful in further experimental and morphological studies of the white laboratory rats.
A Clinical and Biological Guide for Understanding Chemotherapy-Induced Alopecia and Its Prevention
Authors: Dunnill Christopher John , Al-Tameemi Wafaa , Collett Andrew , Haslam Iain Stuart , Georgopoulos Nikolaos Theodoros 
Published: September 2017

Abstract

Chemotherapy-induced alopecia (CIA) is the most visibly distressing side effect of commonly administered chemotherapeutic agents. Because psychological health has huge relevance to lifestyle, diet, and self-esteem, it is important for clinicians to fully appreciate the psychological burden that CIA can place on patients. Here, for the first time to our knowledge, we provide a comprehensive review encompassing the molecular characteristics of the human hair follicle (HF), how different anticancer agents damage the HF to cause CIA, and subsequent HF pathophysiology, and we assess known and emerging prevention modalities that have aimed to reduce or prevent CIA. We argue that, at present, scalp cooling is the only safe and U.S. Food and Drug Administration-cleared modality available, and we highlight the extensive available clinical and experimental (biological) evidence for its efficacy. The likelihood of a patient that uses scalp cooling during chemotherapy maintaining enough hair to not require a wig is approximately 50%. This is despite different types of chemotherapy regimens, patient-specific differences, and possible lack of staff experience in effectively delivering scalp cooling. The increased use of scalp cooling and an understanding of how to deliver it most effectively to patients has enormous potential to ease the psychological burden of CIA, until other, more efficacious, equally safe treatments become available.

Implications for Practice
Chemotherapy-induced alopecia (CIA) represents perhaps the most distressing side effect of chemotherapeutic agents and is of huge concern to the majority of patients. Scalp cooling is currently the only safe option to combat CIA. Clinical and biological evidence suggests improvements can be made, including efficacy in delivering adequately low temperature to the scalp and patient-specific cap design. The increased use of scalp cooling, an understanding of how to deliver it most effectively, and biological evidence-based approaches to improve its efficacy have enormous potential to ease the psychological burden of CIA, as this could lead to improvements in treatment and patient quality-of-life.
Deflating the shale gas potential of South Africa’s Main Karoo basin
Authors: De Kock Michiel O. , Beukes Nicolas J. , Adeniyi Elijah O. , Cole Doug , Götz Annette E. , Geel Claire , Ossa Frantz-Gerard 
Published: September 2017

The Main Karoo basin has been identified as a potential source of shale gas (i.e. natural gas that can be extracted via the process of hydraulic stimulation or ‘fracking’). Current resource estimates of 0.4–11x109 m3 (13–390 Tcf) are speculatively based on carbonaceous shale thickness, area, depth, thermal maturity and, most of all, the total organic carbon content of specifically the Ecca Group’s Whitehill Formation with a thickness of more than 30 m. These estimates were made without any measurements on the actual available gas content of the shale. Such measurements were recently conducted on samples from two boreholes and are reported here. These measurements indicate that there is little to no desorbed and residual gas, despite high total organic carbon values. In addition, vitrinite reflectance and illite crystallinity of unweathered shale material reveal the Ecca Group to be metamorphosed and overmature. Organic carbon in the shale is largely unbound to hydrogen, and little hydrocarbon generation potential remains. These findings led to the conclusion that the lowest of the existing resource estimates, namely 0.4x109 m3 (13 Tcf), may be the most realistic. However, such low estimates still represent a large resource with developmental potential for the South African petroleum industry. To be economically viable, the resource would be required to be confined to a small, well-delineated ‘sweet spot’ area in the vast southern area of the basin. It is acknowledged that the drill cores we investigated fall outside of currently identified sweet spots and these areas should be targets for further scientific drilling projects.

Significance:

This is the first report of direct measurements of the actual gas contents of southern Karoo basin shales.
The findings reveal carbon content of shales to be dominated by overmature organic matter.
The results demonstrate a much reduced potential shale gas resource presented by the Whitehill Formation.