bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Sales Law
Authors: Huber Peter
Published: May 2019

The story of comparative law in the field of sales contracts is inextricably linked to Ernst Rabel. Rabel not only prepared the basis for any comparative study of the modern law of sales in his epochal treatise ‘Das Recht des Warenkaufs’, but also initiated the process of world-wide harmonization of the law of international sales. This process has not only led to one of the most important international conventions in the field of private law (the 1980 UN Convention on Contracts for the International Sale of Goods—CISG) but has also become a highly influential factor in the field of comparative sales law in the twentieth century. The article first outlines the most important projects in this area and their interaction with comparative law. It then goes on to discuss selected characteristic features of the law of sales which are interesting from a comparative point of view.
Comparative Property Law
Authors: Van Erp Sjef
Published: May 2019

The number of studies in comparative property law has recently been growing as a result of efforts to harmonize, or unify, certain aspects of property law in areas crucial for international business transactions. Increasing regional and global economic integration has led to a growing awareness that the divergence of legal rules may lead to inefficiency and raise transactions costs. In Europe the four economic freedoms (free movement of goods, persons, services, and capital), to which now should be added as a fifth freedeom the free movement of data, laid down in the Treaty on European Union and the Treaty on the Functioning of the European Union, have a growing influence on property law. Comparative property law, once considered to be fairly static, is turning into an increasingly dynamic field of law. This is to a considerable degree a consequence of European and global economic integration, and the resulting legal integration. The national property laws, whether belonging to the civilian or the common law tradition, will all be affected by this change.
Comparative Labour Law
Authors: Finkin Matthew W.
Published: May 2019

This article proceeds in four stages. First, it takes up the emergence of labour law and its comparative offspring as a discipline. Second, it provides a crude taxonomy of comparative labour law scholarship. Third, it treats the role comparativism has played in the development of national labour policy from the nineteenth century to the present. Fourth, and to come full circle, it situates the comparative study with respect to the contemporary quandary of labour law as a discipline. Comparative labour law was born fast upon the construction of labour law as a subject of instruction and academic study. Even from the beginning, however, it was far from clear what labour law was. Today, that question has recrudesced: labour law is a discipline in search of an identity and, to some, a future. Consequently, attention rightly turns first to the root of which comparative study is a branch.
Comparative Company Law
Authors: Hopt Klaus J.
Published: May 2019

Comparative company law starts with the rise of the modern company in the first half of the 19th century. Ever since the need for looking across the border was felt by legislators, lawyers, academics, judges and regulators. Most recently there has been a renewed interest in comparative company law, partly because of the emergence of European company law and partly because the corporate governance movement has sharpened the sense of competition with other countries. Comparative company law follows the close relations of company, capital market and banking law that exist today, in particular after the financial crisis. Comparative company law must also take notice of company self-regulation and the international code movement and is more and more influenced by economic considerations. The chapter concludes with perspectives for future research.
Comparative Constitutional Law
Authors: Tushnet Mark
Published: May 2019

This article examines the evolution of the field of comparative constitutional law and its relationship to politics and international rights; constitutionalism; constitutional foundings and transformations; constitutional structures; structures of judicial review; generic constitutional law; and national identity. Innumerable comparative studies address the ways in which different constitutions and constitutional systems deal with specific topics, such as privacy, free expression, and gender equality. However valuable such studies have been in bringing information about other constitutional systems to the attention of scholars versed in their own systems, their analytic payoff is sometimes questionable. Scholarship in comparative constitutional law is perhaps too often insufficiently sensitive to national differences that generate differences in domestic constitutional law. Or, put another way, that scholarship may too often rest on an implicit but insufficiently defended preference for the universalist approach to comparative legal study over the particularist one.
Comparative Administrative Law
Authors: Bell John S.
Published: May 2019

Comparative administrative law is a long-standing discipline. The study of other administrative law systems both in order to understand one’s own system better and to find models for improvement has been occurring for over 150 years. It is closely bound up with national institutions and traditions, as well as national constitutional values and ways of operating. Any comparative approach has to take full account of the institutional context in which a particular problem or procedure occurs and to ensure that full account of these nationally specific features is taken before any attempt is made to generalize or compare. This article describes the scope of the subject, the values served by administrative law, and influences shaping administrative law. It also compares the powers, organizations, and procedures of the administration, as well as legal redress.
Comparative Law and European Union Law
Authors: Jacobs Sir Francis
Published: May 2019

This chapter discusses three primary roles of comparative law in EU law. First, comparative law is used in the making and application of European law: for example, in the crafting and interpretation of European legislation and in the case law of the European Court of Justice. Second, European law has exerted a significant influence on other legal systems. A third role of comparative law relates to questions about the very nature of European law: how it is to be classified, or whether it is a novel form of ‘transnational law’. Civil and common law systems are also considered in relation to comparative law, along with the ‘components’ or ‘sources’ of European law: treaty provisions and constitutional principles, EU legislation, general principles of law, international law, and case law of the Court. The chapter concludes with an overview of the distinction between private law and public law, a comparison of EU and federal systems, and a survey of other transnational systems inspired by the European Union model.
Comparative Law and Human Rights
Authors: Besson Samantha
Published: May 2019

This chapter discusses the boundaries, the authority, and the methods of comparative human rights law (CHRL). It first explains what comparing human rights means and how it developed historically, along with some distinctions between subfields of CHRL, before considering the transnational consensus method, how it works, and how it relates to some of the general methods of comparative law. It goes on to examine the authority of and the justifications for the authority of CHRL, the democratic objection to the legitimacy of CHRL, and selected issues in CHRL. In particular, it analyzes three potential solutions to the problem of securing the universal scope of CHRL: the turn to quantitative methods in CHRL, the development of (trans-)regional human rights comparison, and generalizing CHRL to all universal human rights treaty bodies. In conclusion, the chapter argues that, unlike other areas of domestic and even international law, human rights law amounts to a necessarily comparative project, i.e. a law-making enterprise in which comparative law is not only interesting, but is required and in which it should not only amount to a piecemeal and retail practice, but to a systematic and universal one.
Development of Comparative Law in Great Britain
Authors: Cairns John W.
Published: May 2019

Comparative law developed in Great Britain in the second half of the nineteenth century. The discipline focused mainly on imperial problems of foreign law and the assimilation of the laws of the different dominions of the Empire. Despite an interest in evolutionary jurisprudence, British scholars generally did not view the discipline as involving a search for universal principles. Through the twentieth century, there was a tendency to focus on comparison of the common law with the civil law, especially that of France. The discipline started to be significant in the universities with the expansion of legal education after the Second World War. Some aspects of the discipline developed into more anthropological studies, others remained more traditionally academic, while British membership of the European Economic Community (EEC) and more global pressures engendered interest in issues such as legal transplants and mixed systems, even if British scholars have traditionally been sceptical of unification of laws as an aim.
Neodavidsonianism in Semantics and Syntax
Authors: Lohndal Terje
Published: May 2019

This chapter discusses the impact and development of Donald Davidson’s original proposal that there is an event variable in the logical forms that encode meaning in natural languages. Originally, Davidson was concerned with adjuncts and their entailments, but this chapter demonstrates how these insights were extended to apply to thematic arguments. It is argued that there is a family of Neodavidsonian proposals that all have in common that they argue for Neodavidsonian logical forms. However, they differ substantially in how they derive these logical forms, notably in what assumptions they make concerning the syntactic structure that serves as an input to the semantic interpretation. The chapter provides an overview of some of the different approaches, closing by defending a view that can be viewed as a natural consequence of the original insight due to Davidson: not only event predicates, but also argument predicates are linked together by way of conjunction.
Adjectives and Event Structure
Authors: Baglini Rebekah , Kennedy Christopher
Published: May 2019

This chapter investigates the relationship between adjectives and event structure by looking at properties of deverbal adjectives and deadjectival verbs. Although simple adjectives are not eventive, they nevertheless play an important role in matters of event structure, both in the way that they influence the eventive properties of verbs that they are derivationally related to, and in the way that an understanding of the scalar properties of adjectival meaning informs theorizing about eventive meanings. Although often considered in isolation, we show that adjectival gradability and verbal aspect are intimately related scalar phenomena. The structural properties of an adjectival scale determine the aspectual class of a derived event predicate. Similarly, the aspectual structure of a verb phrase constrains the scale structure of an adjectival participle. Our discussion focuses primarily on degree-based approaches to these phenomena, but we also consider alternative approaches based in a more articulated ontology for states.
Lexicalization Patterns
Authors: Levin Beth , Hovav Malka Rappaport
Published: May 2019

This chapter surveys accounts of systematic cross-linguistic differences in the distribution of conceptual components across the constituents of clauses describing the same event. These differences are embodied in Talmy’s seminal V(erb)-framed vs. S(atellite)-framed typology, first applied to directed motion events. Subsequent work supports this typology by showing that other properties of a language cluster with its motion event description type, but also reveals that the empirical landscape is more complex than a two-way typology can capture. A fuller account requires determining the grammatical factors underpinning the typological patterns. We review current accounts which derive these patterns by attributing them to: (i) differences in properties of a language’s lexical items and generalizations concerning the structure of its lexicon and (ii) differences in compositional mechanisms. The chapter also considers Manner/Result Complementarity, a constraint on the conceptual content encoded in the basic components of a verb’s meaning, in the context of lexicalization patterns.
Secondary Predication
Authors: Rapoport Tova
Published: May 2019

This chapter examines the thematic and aspectual properties of two constructions of secondary predication, resultatives and depictives. The thematic and aspectual constraints on the two types of secondary predicate and their hosts are detailed, as are the semantic constraints on the relation between the main verb and each of the secondary predicate types and the structural representation of these relations. The final sections focus on the issue of the argument or adjunct status of the different types of depictive and resultative (such as true versus false resultative) predicates, the role of each type in the event structure representation, and the possibility of distinguishing between secondary predicates and certain adverbial types. As noted by the studies reviewed in this chapter, an examination of secondary predicate constructions sheds light on properties of verb and adjective types, the characterization of argument versus adjunct, and the thematic and aspectual underpinnings of event structure.
Inner Aspect Crosslinguistically
Authors: deMena Travis Lisa
Published: May 2019

This chapter explores the nature of Inner Aspect by investigating non-culminating accomplishments languages. In these languages, the unmarked way of saying ‘x killed y’ does not entail that y is dead. Intriguingly, in many of these languages, the morphology needed to encode entailment brings with it other meanings such as extra effort, nonintentionality, suddenness. First, a syntactic account of the role of this morpheme posits a morphologically realized endpoint in Inner Aspect within the predicate. Then this account is compared to an alternate view that concentrates on the semantics of the construction and the modal meaning of the morpheme. Finally, it is argued that phonological evidence must also be taken into consideration in any further study. The goal of the chapter is not to provide any solution, but to raise awareness of the relevant issues.
Coherence Relations
Authors: Kehler Andrew
Published: May 2019

Mentation does not proceed via the pursuit of random paths of thought, but instead by way of connections among ideas that are guided by certain types of associative principles. Since a primary function of language is to evoke thoughts in the minds of interlocutors, it is unsurprising that we would find evidence that these associative principles are at play in the manner in which language is structured and interpreted. This chapter provides a brief survey into some of the respects in which this is the case at the discourse and lexical levels. The data argue for a rich notion of event structure that makes crucial reference to different types of association, and illustrate how the importance of event structure in linguistic theory goes beyond merely accounting for the representation of events and the semantics of the words used to express them.
Tense and Aspect in Discourse Representation Theory
Authors: Kamp Hans
Published: May 2019

This chapter is about the treatment of tense and aspect in Discourse Representation Theory. The focus is on the role that different tense forms and other sentence constituents with temporal and/or aspectual meaning components have on the interpretation of sentence sequences: how the occurrence of such a constituent in a sentence links its interpretation temporally or aspectually to that of the sentence of sentences preceding it. The concern on the discourse linking role of tenses and other sentence constituents led to DRT in the first place, with its architecture that is geared to deal with the systematic properties of incremental discourse interpretation. Novel about the chapter is its discussion of the distinction between temporal cross-sentential discourse links that are fully determined by the choice of tense forms alone and those which also rely on world knowledge and discourse relations. DRT work on sentence- and word-internal structure is not discussed.
Form-Independent Meaning Representation for Eventualities
Authors: Steedman Mark
Published: May 2019

Linguists and philosophers since Aristotle have attempted to reduce natural language semantics in general, and the semantics of eventualities in particular, to a ‘language of mind’, expressed in terms of various collections of underlying language-independent primitive concepts. While such systems have proved insightful enough to suggest that such a universal conceptual representation is in some sense psychologically real, the primitive relations proposed, based on oppositions like agent-patient, event-state, etc., have remained incompletely convincing. This chapter proposes that the primitive concepts of the language of mind are ‘hidden’, or latent, and must be discovered automatically by detecting consistent patterns of entailment in the vast amounts of text that are made available by the internet using automatic syntactic parsers and machine learning to mine a form- and language-independent semantic representation language for natural language semantics. The representations involved combine a distributional representation of ambiguity with a language of logical form.
Event Composition and Event Individuation
Authors: Truswell Robert
Published: May 2019

This chapter explores a consequence of Davidson’s (1967) foundational hypothesis that events are in some nontrivial way similar to individuals: just as an individual can form part of a larger individual, an event can form part of a larger event. This implies that events may be composed of multiple smaller events. The chapter addresses two related questions: First, what are the logical underpinnings of the relationship between events and their parts? Second, how do we recognize, or individuate, events? Both of these are addressed through the lens of parallels with the domain of individuals. With respect to the first, the chapter summarizes foundational work by Link and others on mereological relations between events and individuals. With respect to the second, it proposes that events can be individuated in different ways, depending on whether they are perceived as purely physical, as intentional, or other.
Force Dynamics
Authors: Copley Bridget
Published: May 2019

This chapter examines the semantics of force dynamics, from its cognitive linguistic origins to recent formal approaches. Force dynamics proves to be a fruitful addition to the ontology, allowing natural representations of the distinction between energy and change, interactions within and between events, and ceteris paribus effects, among other phenomena. This makes force dynamics useful, perhaps even indispensable, for a full understanding of event structure and related domains such as aspect, modality, and inference. A debate is just getting underway on how to formally represent forces in ways that are faithful to morphosyntax, compositional semantics, and conceptual plausibility. It may be that lexical-conceptual representations of forces differ from functional (grammaticalized) representations of forces.
Diverse taxa of zooplankton inhabit hypoxic waters during both day and night in a temperate eutrophic lake
Authors: Nolan Sean , Bollens Stephen M , Rollwagen-Bollens Gretchen
Published: May 2019

As the frequency and intensity of hypoxic events increase in both fresh and marine waters, understanding the ecological effects of hypoxia becomes more important. The extant literature reports varying effects of hypolimnetic hypoxia on the vertical distribution and diel vertical migration (DVM) of zooplankton, with some but not all taxa reported to avoid hypoxic waters. We studied the vertical distribution and DVM of diverse zooplankton taxa throughout three seasons over 2 years (2014 and 2015) in Lacamas Lake, WA, USA. We observed hypoxia (<2 mg L−1 dissolved oxygen) in the hypolimnion of Lacamas Lake during five of six sampling periods, with zooplankton populations often exhibiting ‘h-metric’ values (defined as the proportion of a zooplankton population residing within hypoxic waters) ranged from 0.14 to 1.00, with an overall mean of h = 0.66. Moreover, we observed a lack of DVM in most zooplankton taxa on most occasions. Our findings indicate both community-level and taxon-specific zooplankton tolerances to hypoxia, although the exact mechanisms at play remain to be fully elucidated. Nevertheless, the common residency in hypoxic waters and the lack of DVM by diverse zooplankton taxa that we observed likely have implications for food web dynamics in Lacamas Lake and other water bodies.
Statistical Modeling of Distribution Patterns: A Markov Random Field Implementation and Its Application on Areas of Endemism
Authors: Salinas Nelson R , Wheeler Ward C
Published: May 2019

A statistical framework to infer areas of endemism from geographic distributions is proposed. This novel method is based on hidden Markov random fields (HMRFs), a type of undirected graph model commonly used in computer vision. This framework assumes areas of endemism are the states of the hidden layer of the model, whereas taxon distributions are emitted values in the observed layer. Taxon distributions are associated to the observed layer through a clustering procedure based on the extent of overlap. Observations are emitted by the hidden layer according to a Gaussian distribution, whereas the joint distribution of the hidden layer follows a Potts model. State and parameter inference of the maximum a posteriori configuration is performed through a modified version of the expectation-maximization algorithm. The optimal number of areas of endemism in the data set is estimated through the pseudolikelihood information criterion, a model selection procedure that uses an approximation to likelihood. The performance of the new algorithm was assessed on simulated data, and compared with the most popular methods for delimitation of areas of endemism: biotic element analysis, parsimony analysis of endemism, and endemicity analysis. HMRFs efficiently recovered the true pattern across a wide range of uncertainty values. The performance was also examined on empirical data: South African weevils (Sciobius) and Central American ground beetles and funnel-web tarantulas (Carabidae and Dipluridae, respectively). HMRFs uncovered six areas of endemism from the weevil data set, whereas eight were estimated for the Central American arthropods (compared with 3–5 and 3–14 from the other methods, respectively).
A Phosphate-Dependent Requirement for Transcription Factors IPD3 and IPD3L During Arbuscular Mycorrhizal Symbiosis in Medicago truncatula
Authors: Lindsay Penelope L. , Williams Brandon N. , MacLean Allyson , Harrison Maria J.
Published: May 2019

During arbuscular mycorrhizal (AM) symbiosis, activation of a symbiosis signaling pathway induces gene expression necessary for accommodation of AM fungi. Here, we focus on pathway components Medicago truncatula INTERACTING PROTEIN OF DOES NOT MAKE INFECTIONS 3 (IPD3) and IPD3 LIKE (IPD3L), which are potential orthologs of Lotus japonicus CYCLOPS, a transcriptional regulator essential for AM symbiosis. In the double mutant ipd3 ipd3l, hyphal entry through the epidermis and overall colonization levels are reduced relative to the wild type but fully developed arbuscules are present in the cortex. In comparison with the wild type, colonization of ipd3 ipd3l is acutely sensitive to higher phosphate levels in the growth medium, with a disproportionate decrease in epidermal penetration, overall colonization, and symbiotic gene expression. When constitutively expressed in ipd3 ipd3l, an autoactive DOES NOT MAKE INFECTIONS 3 induces the expression of transcriptional regulators REDUCED ARBUSCULAR MYCORRHIZA 1 and REQUIRED for ARBUSCULE DEVELOPMENT 1, providing a possible avenue for arbuscule development in the absence of IPD3 and IPD3L. An increased sensitivity of ipd3 ipd3l to GA3 suggests an involvement of DELLA. The data reveal partial redundancy in the symbiosis signaling pathway, which may ensure robust signaling in low-phosphorus environments, while IPD3 and IPD3L maintain signaling in higher-phosphorus environments. The latter may buffer the pathway from short-term variation in phosphorus levels encountered by roots during growth in heterogeneous soil environments.
Low Genetic Diversity Suggests the Recent Introduction of Dogwood Powdery Mildew to North America
Authors: Wyman Christopher R. , Hadziabdic Denita , Boggess Sarah L. , Rinehart Timothy A. , Windham Alan S. , Wadl Phillip A. , Trigiano Robert N.
Published: May 2019

Cornus florida (flowering dogwood) is a popular understory tree endemic to the eastern hardwood forests of the United States. In 1996, dogwood powdery mildew caused by Erysiphe pulchra, an obligate biotrophic fungus of large bracted dogwoods, reached epidemic levels throughout the C. florida growing region. In the late 1990s, both sexual and asexual stages of E. pulchra were regularly observed; thereafter, the sexual stage was found less frequently. We examined the genetic diversity and population structure of 167 E. pulchra samples on C. florida leaves using 15 microsatellite loci. Samples were organized into two separate collection zone data sets, separated as eight zones and two zones, for the subsequent analysis of microsatellite allele length data. Clone correction analysis reduced the sample size to 90 multilocus haplotypes. Our study indicated low genetic diversity, a lack of definitive population structure, low genetic distance among multilocus haplotypes, and significant linkage disequilibrium among zones. Evidence of a population bottleneck was also detected. The results of our study indicated a high probability that E. pulchra reproduces predominately via asexual conidia and lend support to the hypothesis that E. pulchra is an exotic pathogen to North America.

[Formula: see text] Copyright © 2019 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .
PDEparams: Parameter fitting toolbox for partial differential equations in Python
Authors: Parra-Rojas César , Hernandez-Vargas Esteban A.
Published: May 2019

Motivation

Partial differential equations (PDEs) is a well-established and powerful tool to simulate multi-cellular biological systems. However, available free tools for validation against data are not established. ThePDEparamsmodule provides flexible functionality in Python for parameter estimation in PDE models.

Results

ThePDEparamsmodule provides a flexible interface and readily accommodates different parameter analysis tools in PDE models such as computation of likelihood profiles, and parametric boot-strapping, along with direct visualisation of the results. To our knowledge, it is the first open, freely available tool for parameter fitting of PDE models.

Availability and implementation

ThePDEparamsmodule is distributed under the MIT license. The source code, usage instructions and step-by-step examples are freely available on GitHub atgithub.com/systemsmedicine/PDE_params.

Contact

vargas@fias.uni-frankfurt.de
Size- and sex-specific predation on dung flies by amphibian and arthropod predators – size match matters
Authors: Blanckenhorn Wolf U. , Cozzi Gabriele , Jäggli Gregory , Busso Juan Pablo
Published: May 2019

Because predator-prey interactions in nature are multifarious, linking phenomenological predation rates to the underlying behavioural or ecological mechanisms is challenging. Size- and sex-specific predation has been implicated as a major selective force keeping animals small, affecting the evolution of body size and sexual size dimorphism. We experimentally assessed predation by various amphibian (frogs and toads) and arthropod predators (bugs, flies, spiders) on three species of dung flies with similar ecology but contrasting body sizes, sexual size dimorphism and coloration. Predators were offered a size range of flies in single- or mixed-sex groups. As expected based on optimal foraging theory, some anurans (e.g.Bufo bufo) selected larger prey, thus selecting against large body size of the flies, while others (Bombina variagataandRana esculenta) showed no such pattern. Small juvenileRana temporariametamorphs, in contrast, preferred small flies, as did all arthropod predators, a pattern that can be explained by larger prey being better at escaping. The more mobile males were not eaten more frequently or faster than the cryptic females, even when conspicuously colored. Predation rates on flies in mixed groups permitting mating activity were not higher, contrary to expectation, nor was predation generally sex-specific. We conclude that the size-selectivity of predators, and hence the viability selection pattern exerted on their prey, depends foremost on the relative body sizes of the two in a continuous fashion. Sex-specific predation by single predators appears to contribute little to sexual dimorphism. Therefore, the mechanistic study of predation requires integration of both the predator’s and the prey’s perspectives, and phenomenological field studies of predation remain indispensable.
Tissue-specific Genome Editing in vivo by MicroRNA-repressible Anti-CRISPR Proteins
Authors: Lee Jooyoung , Mou Haiwei , Ibraheim Raed , Liang Shun-Qing , Xue Wen , Sontheimer Erik
Published: May 2019

CRISPR-Cas systems are bacterial adaptive immune pathways that have revolutionized biotechnology and biomedical applications. Despite the potential for human therapeutic development, there are many hurdles that must be overcome before its use in clinical settings. Some clinical safety concerns arise from persistent activity of Cas9 after the desired editing is complete, or from editing activity in unintended cell types or tissues upon in vivo delivery [e.g. by adeno-associated viruses (AAV)]. Although tissue-specific promoters and serotypes with tissue tropisms can be used, suitably compact promoters are not always available for desired cell types, and AAV tissue tropisms are not absolute. To reinforce tissue-specific editing, we exploited anti-CRISPR proteins (Acrs), which are proteins evolved as countermeasures against CRISPR immunity. To inhibit Cas9 in all ancillary tissues without compromising editing in the target tissue, we established a flexible platform in which an Acr transgene is repressed by endogenous, tissue-specific microRNAs (miRNAs). We demonstrate that miRNAs regulate the expression of an Acr transgene bearing miRNA-binding sites in its 3’ UTR, and control subsequent genome editing outcomes in a cell-type specific manner. We also show that the strategy is applicable to multiple Cas9 orthologs and their respective Acrs. Furthermore, we demonstrate that in vivo delivery of Cas9 and Acrs that are targeted for repression by liver-specific miR-122 allow editing in the liver while Acrs devoid of miRNA regulation prevent Cas9 activity. This strategy provides additional safeguards against off-tissue genome editing by confining Cas9 activity to selected cell types.
Dietary restriction improves fitness of ageing parents but reduces fitness of their offspring
Authors: Mautz Brian S. , Lind Martin I. , Maklakov Alexei A.
Published: May 2019

Dietary restriction (DR) is a well-established intervention to extend lifespan across taxa. Recent studies suggest that DR-driven lifespan extension can be cost-free, calling into question a central tenant of the evolutionary theory of ageing. Nevertheless, boosting parental longevity can reduce offspring fitness. Such intergenerational trade-offs are often ignored but can account for the ‘missing costs’ of longevity. Here, we use the nematode Caenorhabditis remanei to test for effects of DR by fasting on fitness of females and their offspring. Females deprived of food for six days indeed had increased fecundity, survival and stress resistance after re-exposure to food compared to their counterparts with constant food access. However, offspring of DR mothers had reduced early and lifetime fecundity, slower growth rate, and smaller body size at sexual maturity. These findings support the direct trade-off between investment in soma and gametes challenging the hypothesis that increased somatic maintenance and impaired reproduction can be decoupled.
Patterned substrates modulate growth and dynamics of 3D cellular systems
Authors: Fanous Michael J. , Li Yanfen , Kandel Mikhail E. , Kilian Kristopher A. , Popescu Gabriel
Published: May 2019

The development of 3D cellular architectures during development and pathological processes involves intricate migratory patterns that are modulated by genetics and the surrounding microenvironment. The substrate composition of cell cultures has been demonstrated to influence growth, proliferation, and migration in 2D. Here we study the growth and dynamics of mouse embryonic fibroblast (MEF) cultures patterned in a tissue sheet which then exhibits 3D growth. Using gradient light interference microscopy (GLIM), a label-free quantitative phase imaging approach, we explored the influence of geometry on cell growth patterns and rotational dynamics. We apply, for the first time to our knowledge, dispersion-relation phase spectroscopy (DPS) in polar coordinates to generate the radial and rotational cell mass-transport. Our data show that cells cultured on engineered substrates undergo rotational transport in a radially independent manner and exhibit faster vertical growth than the control, unpatterned cells. The use of GLIM and polar DPS provides a novel quantitative approach to studying the effects of spatially patterned substrates on cell motility and growth.
Assembly Mechanisms of Neotropical Butterfly Communities Along an Environmental Gradient
Authors: Checa María F. , Donoso David , Levy Elisa , Mena Sebastián , Rodriguez Jaqueline , Willmott Keith
Published: May 2019

Our goal was to test the hypothesis that assembly processes that limit species similarity (i.e., competition) predominantly occur in more ‘stable’ abiotic environments, whereas habitat filtering (i.e., habitat characteristics) is a major driver of community composition within more variable environments at regional (e.g., aseasonal vs seasonal forests) and local scales (e.g., understory vs. canopy). A combined approach of phylogenetic- and functional trait-based analyses using forewing length and aspect ratio as traits, were used to this hypothesis.

A 3-year survey was carried out at three sites (i.e., wet, transition and dry forests) across a climatic gradient in western Ecuador. Transition and dry forests were considered as seasonal, whereas wet forest were considered aseasonal. Butterflies were sampled using traps baited with rotting banana and prawn every two months from Nov 2010 to Sep 2013. Traps were set up at two heights, in the understory and canopy. DNA was extracted to sequence the barcode’ section of the mitochondrial gene cytochrome oxidase 1 (COI) for phylogenetic analyses. Measurements of morphological traits, forewing length and aspect ratio were done using digital photographs of specimens.

A total of 6466 specimens representing 142 species of Nymphalidae were recorded. Based on phylogenetic- and trait-based analyses, we rejected the hypothesis that assembly processes that limit species similarity (i.e., competition) are likely to predominantly occur in more ‘stable’ abiotic environments, whereas habitat filtering can be a major driver of community composition within more variable environments at regional (i.e., aseasonal forest vs seasonal forests) and local scales (i.e., understory vs. canopy). My study of assembly mechanisms revealed the opposite pattern, with stronger evidence for the action of ecological filters in the assembly of butterfly communities from the wet aseasonal forests, and competition likely to be a major assembly process within dry seasonal forests. The present study therefore provided new insights into community assembly mechanisms in one of the richest butterfly faunas worldwide.
Medial entorhinal cortex activates in a traveling wave
Authors: Hernández-Pérez J.J. , Cooper K.W. , Newman E.L.
Published: May 2019

Traveling waves of cortical activity are hypothesized to organize cortical information processing and support interregional communication. Yet, it remains unknown whether interacting areas exhibit the matched traveling waves necessary to support this hypothesized form of interaction. Here, we show that the strongly-interacting medial entorhinal cortex (MEC) and hippocampus exhibit matched traveling waves. We demonstrate that both the field potential and spiking in the MEC exhibit prominent 6-12 Hz ‘theta’ traveling waves matching those of the hippocampus. The theta phase shifts observed along the MEC were accounted for largely by variation in waveform asymmetry. From this, we hypothesize that that gradients in local physiology underlie both the generation of MEC traveling waves and the functional variations observed previously across the MEC.
Comparing low-pass sequencing and genotyping for trait mapping in pharmacogenetics
Authors: Wasik Kaja , Berisa Tomaz , Pickrell Joseph K. , Li Jeremiah H. , Fraser Dana J. , King Karen , Cox Charles
Published: May 2019

Low pass sequencing has been proposed as a cost-effective alternative to genotyping arrays to identify genetic variants that influence multifactorial traits in humans. For common diseases this typically has required both large sample sizes and comprehensive variant discovery. Genotyping arrays are also routinely used to perform pharmacogenetic (PGx) experiments where sample sizes are likely to be significantly smaller, but clinically relevant effect sizes likely to be larger. To assess how low pass sequencing would compare to array based genotyping for PGx we compared a low-pass assay (in which 1× coverage or less of a target genome is sequenced) along with software for genotype imputation to standard approaches. We sequenced 79 individuals to 1× genome coverage and genotyped the same samples on the Affymetrix Axiom Biobank Precision Medicine Research Array (PMRA). We then down-sampled the sequencing data to 0.8×, 0.6×, and 0.4× coverage, and performed imputation. Both the genotype data and the sequencing data were further used to impute human leukocyte antigen (HLA) genotypes for all samples. We compared the sequencing data and the genotyping array data in terms of four metrics: overall concordance, concordance at single nucleotide polymorphisms in pharmacogenetics-related genes, concordance in imputed HLA genotypes, and imputation r2. Overall concordance between the two assays ranged from 98.2% (for 0.4× coverage sequencing) to 99.2% (for 1× coverage sequencing), with qualitatively similar numbers for the subsets of variants most important in pharmacogenetics. At common single nucleotide polymorphisms (SNPs), the mean imputation r2from the genotyping array was 90%, which was comparable to the imputation r2from 0.4× coverage sequencing, while the mean imputation r2from 1× sequencing data was 96%. These results indicate that low-pass sequencing to a depth above 0.4× coverage attains higher power for trait mapping when compared to the PMRA.
Kinetic characteristics of propofol-induced inhibition of electron-transfer chain and fatty acid oxidation in human and rodent skeletal and cardiac muscles
Authors: Urban Tomáš , Waldauf Petr , Krajčová Adéla , Jiroutková Kateřina , Halačová Milada , Džupa Valér , Janoušek Libor , Pokorná Eva , Duška František
Published: May 2019

Introduction

Propofol causes a profound inhibition of fatty acid oxidation (FAO) and reduces spare electron transfer chain (ETC) capacity in a range of human and rodent cells and tissues – a feature that might be related to the pathogenesis of Propofol Infusion Syndrome. We aimed to explore the mechanism of propofol-induced alteration of bioenergetic pathways by describing its kinetic characteristics.

Methods

We obtained samples of skeletal and cardiac muscle from Wistar rat (n=3) and human subjects: vastus lateralis from hip surgery patients (n=11) and myocardium from brain-dead organ donors (n=10). We assessed mitochondrial functional indices using standard SUIT protocol and high resolution respirometry in fresh tissue homogenates with or without short-term exposure to a range of propofol concentration (2.5-100 μg/ml). After finding concentrations of propofol causing partial inhibition of a particular pathways, we used that concentration to construct kinetic curves by plotting oxygen flux against substrate concentration during its stepwise titration in the presence or absence of propofol. By spectrophotometry we also measured the influence of the same propofol concentrations on the activity of isolated respiratory complexes.

Results

We found that human muscle and cardiac tissues are more sensitive to propofol-mediated inhibition of bioenergetic pathways than rats tissue. In human homogenates, palmitoyl carnitine-driven respiration was inhibited at much lower concentrations of propofol than that required for a reduction of ETC capacity, suggesting FAO inhibition mechanism different from downstream limitation or carnitine-palmitoyl transferase-1 inhibition. Inhibition of Complex I was characterised by more marked reduction of Vmax, in keeping with non-competitive nature of the inhibition and the pattern was similar to the inhibition of Complex II or ETC capacity. There was no inhibition of Complex IV nor increased leak through inner mitochondrial membrane with up to 100 μg/ml of propofol. If measured in isolation by spectrophotometry, propofol 10 μg/ml did not affect the activity of any respiratory complexes.

Conclusion

In human skeletal and heart muscle homogenates, propofol in concentrations that are achieved in propofol-anaesthetized patients, causes a direct inhibition of fatty acid oxidation, in addition to inhibiting flux of electrons through inner mitochondrial membrane. The inhibition is more marked in human as compared to rodent tissues.
A competence-regulated toxin-antitoxin system inHaemophilus influenzae
Authors: Black Hailey Findlay , Mastromatteo Scott , Sinha Sunita , Ehrlich Rachel L. , Nislow Corey , Mell Joshua Chang , Redfield Rosemary J.
Published: May 2019

Natural competence allows bacteria to respond to environmental and nutritional cues by taking up free DNA from their surroundings, thus gaining both nutrients and genetic information. In the Gram-negative bacteriumHaemophilus influenzae, the genes needed for DNA uptake are induced by the CRP andSxytranscription factors in response to lack of preferred carbon sources and nucleotide precursors. Here we show that one of these genes,HI0659, encodes the antitoxin of a competence-regulated toxin-antitoxin operon (‘toxTA’), likely acquired by horizontal gene transfer from aStreptococcusspecies. Deletion of the putative toxin(HI0660)restores uptake to the antitoxin mutant. The fulltoxTAoperon was present in only 17 of the 181 strains we examined; complete deletion was seen in 22 strains and deletions removing parts of the toxin gene in 142 others. In addition to the expected Sxy-and CRP-dependent-competence promoter,HI0659/660transcript analysis using RNA-seq identified an internal antitoxin-repressed promoter whose transcription starts withintoxTand will yield nonfunctional protein. We propose that the most likely effect of unopposed toxin expression is non-specific cleavage of mRNAs and arrest or death of competent cells in the culture. Although the high frequency oftoxTandtoxTAdeletions suggests that this competence-regulated toxin-antitoxin system may be mildly deleterious, it could also facilitate downregulation of protein synthesis and recycling of nucleotides under starvation conditions. Although our analyses were focused on the effects oftoxTA, the RNA-seq dataset will be a useful resource for further investigations into competence regulation.

ABBREVIATED SUMMARY

The competence regulon ofHaemophilus influenzaeincludes an unprecedented toxin/antitoxin gene pair. When not opposed by antitoxin, the toxin completely prevents DNA uptake but causes only very minor decreases in cell growth and competence gene expression. The TA gene pair was acquired by horizontal gene transfer, and the toxin gene has undergone repeated deletions in other strains.
Perceived managerial and leadership effectiveness in Mexico and the USA
Authors: Ruiz Carlos Enrique , Hamlin Bob
Published: May 2019

Purpose

The purpose of this study was to compare the perceptions of Mexican and US employees about effective and ineffective managerial behaviour.

Design/methodology/approach

A qualitative multiple cross-case comparative analysis of findings obtained from two past emic replication studies of observed effective and ineffective managerial behaviour carried out in Mexico and the USA respectively was conducted.

Findings

Notwithstanding the significant cultural variances between Mexico and the USA underlined by various cross-cultural studies, the findings suggest that Mexican and US employees perceive effective and ineffective managerial behaviour in a very similar manner.

Research limitations/implications

While the results of the study suggest that culture may not play a significant role in the way people perceive managerial and leadership effectiveness, the authors suggest that more replication studies with larger and more balanced gender samples using different methods need to be performed in both countries.

Practical implications

The findings of the study may be relevant for human resource development professionals in both countries when providing training to expatriates for international assignments. Reinforcing the set of managerial practices that are perceived as effective in these two countries and emphasizing those practices that may be particular to Mexico and the USA respectively, could lead to an improvement in the performance of Mexican executives managing in the USA and US executives managing in Mexico.

Originality/value

This paper compares managerial behavioural effectiveness between Mexico and the USA.