scholarly journals Competing hypotheses, ordination and pollen preservation: Landscape impacts of Norse landnám in southern Greenland

2017 ◽  
Vol 236 ◽  
pp. 1-11 ◽  
Author(s):  
Paul M. Ledger ◽  
Kevin J. Edwards ◽  
J. Edward Schofield
2019 ◽  
Author(s):  
Colin Vize ◽  
Donald Lynam ◽  
Katherine Collison ◽  
Josh Miller

As research on the Dark Triad (DT; the interrelated constructs of Machiavellianism, narcissism, and psychopathy) has accumulated, a subset of this research has focused on explicating what traits may account for the overlap among the DT members. Various candidate traits have been investigated, with evidence supporting several of them including Antagonism (vs. Agreeableness), Honesty-Humility, and Callousness and Interpersonal Manipulation (the latter two as a set). The present study sought to test the leading candidates against one another in their ability to account for the shared variance among the DT members. Using a pre-registered analytical plan, we found that Agreeableness (as measured by the IPIP-NEO-120), Honesty-Humility from the HEXACO, and the SRP-III subscales of Callous Affect and Interpersonal Manipulation accounted for all or nearly all of the shared variance among the DT members. BFI-based measures of Agreeableness (BFI and BFI-2) accounted for notably less variance in most cases. The results were consistent across two large samples (Ns of 627 and 628), and across various DT measurement approaches. We argue that the most parsimonious explanation for findings on the core of the DT is that such traits all fall under the umbrella of Antagonism.


SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A11-A11
Author(s):  
Joel Raymond ◽  
Nicholas Everett ◽  
Anand Gururajan ◽  
Michael Bowen

Abstract Introduction Oxytocin is a versatile hypothalamic neuropeptide involved in diverse neurobehavioural processes. Since oxytocin can elicit anxiolytic and serenic effects, one could hypothesise that oxytocin should prime the brain for sleep and promote hypnogenesis. However, based on the social salience hypothesis—that oxytocin promotes prosocial behaviour and directs attention toward social stimuli—one could also posit that oxytocin should promote wakefulness. At present, little research has comprehensively characterised the effect of oxytocin on sleep-wake behaviour and no explanation to reconcile these two seemingly competing hypotheses has been proposed. Methods This study investigated the effects of oxytocin on sleep-wake outcomes using radiotelemetry-based polysomnography in adult male and female Wistar rats. Oxytocin was administered via the intraperitoneal (IP; 0.1, 0.3 and 1 mg/kg) and intranasal (IN; 0.06, 1, 3 mg/kg) routes. Caffeine (IP and IN; 10 mg/kg) was also administered as a wake-promoting positive control. Additionally, pre-treatment with the oxytocin receptor (OTR) antagonist L-368,899 (IP; 5 mg/kg) and vasopressin 1a receptor (V1aR) antagonist SR49059 (IP; 1 mg/kg) followed by oxytocin (IP; 1 mg/kg) was conducted to determine which receptor(s) mediated sleep-wake effects of oxytocin. Results In both male and female rats, IP oxytocin produced dose-dependent effects on sleep-wake behaviour. Specifically, oxytocin initially promoted quiescent wakefulness (a restful but conscious state) at the cost of reducing both active wakefulness and sleep. Throughout the 1.5-hour period post-administration, oxytocin delayed REM sleep onset and reduced the proportion of both NREM and REM sleep. Conversely, IN oxytocin did not significantly alter any sleep-wake parameters at any dose tested. Caffeine demonstrated wake-promoting effects under both the IP and IN routes of administration. The involvement of OTR and V1aR binding in oxytocin-induced effects on sleep-wake outcomes will be discussed. Conclusion These findings appear to reconcile the two competing hypotheses: in rats, IP oxytocin appears to promote a state of quiescent wakefulness—one of calm and rest, but also of conscious responsivity to environmental stimuli. IN oxytocin demonstrated little to no effect on sleep-wake behaviour, which is a crucial finding given the escalating use of IN oxytocin as a therapeutic for conditions with comorbid disordered sleep. Support (if any) None.


Author(s):  
Lilly Rohlfs ◽  
Katja Müller ◽  
Thomas Stach

Abstract Purpose A ventral heart positioned posterior to the branchial basket and equipped with a pericardium is homologous in tunicates and their sister group, the craniates, yet the tunicate model organism Ciona intestinalis features a pericardial body, a structure peculiar to few ascidian species. Here, we set out to distinguish between two competing hypotheses regarding the function of the pericardial body found in the literature: (H1) The pericardial body performs a role in the removal of dysfunctional myocardial cells, and (H2) it is a specialized niche of the immune system involved in defense against parasites. Methods We used histological techniques, transmission electron microscopy, and PCR-based gene sequencing to investigate whether individual ascidians parasitized with apicomplexan protists show signs of infections within the pericardial body. Results In individuals of C. intestinalis from the German North Sea infested with apicomplexan protists, the pericardial body contains numerous myocardial cells in various stages of degeneration while no remnants of parasitic cells could be identified. Conclusion Thus, we conclude that H2—the pericardial body is a specialized niche of the immune system involved in defense against parasites—can be refuted. Rather, our observations support H1, the hypothesis that the pericardial body performs a role in the removal of dysfunctional myocardial cells.


1997 ◽  
Vol 1 (1) ◽  
pp. 175-189
Author(s):  
Yongkyun Chung

The purpose of this study is to investigate the significance of the labor hoarding phenomenon in explaining the SRIRL paradox, or procyclical productivity. Accordingly previous work in these areas is particularly important. First, the direct measurement of labor hoarding shows how prominent the labor hoarding phenomenon is in various industries. Second, evidences of SRIRL at business cycle frequencies are mixed. Third, recent literature on labor hoarding tests indicates that labor hoarding is an indispensible ingredient to explain SRIRL or procyclical productivity among competing hypotheses.


Nematology ◽  
2003 ◽  
Vol 5 (5) ◽  
pp. 699-711 ◽  
Author(s):  
Peter Mullin ◽  
Timothy Harris ◽  
Thomas Powers

AbstractThe systematic position of Campydora Cobb, 1920, which possesses many unique morphological features, especially in pharyngeal structure and stomatal armature, has long been a matter of uncertainty with the 'position of the Campydorinae' (containing only Campydora) being questionable. A review of the morphology of C. demonstrans, the only nominal species of Campydora concluded that the species warranted placement as the sole member of a monotypic suborder, Campydorina, in the order Dorylaimida. Others placed Campydorina in the order Enoplida. We conducted phylogenetic analyses, using 18s small subunit ribosomal DNA sequences generated from a number of taxa in the subclasses Enoplia and Dorylaimia, to evaluate these competing hypotheses. Although precise taxonomic placement of the genus Campydora and the identity of its closest living relatives is in need of further investigation, our analyses, under maximum parsimony, distance, and maximum likelihood criteria, unambiguously indicate that Campydora shares a common, more recent, ancestry with genera such as Alaimus, Pontonema, Tripyla and Ironus (Enoplida), rather than with any members of Dorylaimida, Mononchida or Triplonchida.


2019 ◽  
Vol 306 ◽  
pp. 71-80
Author(s):  
Michał Boroń ◽  
◽  
Anna Brągoszewska ◽  

The source of DNA in a stain is never known with full certainty despite the fact that the evidential profile may match a DNA profile of a given person from the population. The statistical methods, including the likelihood ratio (LR) allow estimating the evidential power of the obtained result and assessing the ratio of the odds between competing hypotheses as to the origin of a DNA profile or mixture. Therefore using analyses based on probabilistic methods seems to be logically justified and allows reducing the subjectivism of interpretation of results. Thorough knowledge and understanding of the principles of operation and limitations of the tools used for statistical interpretation of the results of biological traces analyses in forensics is the key stage that precedes the formulation of conclusions. The process of checking the efficiency of LRmix Studio software as well as reliability and repeatability of results involved single profiles and mixtures from two and three persons. 1971 comparisons with referential profiles were performed. The correctness of generated conditional probabilities was determined and the limits, i.e. drop-outs number in the evidential profile whose exceeding might bring about false LR values were identified.


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