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Competition among pollen or sperm (gametic selection) can cause evolution. Mating systems shape the intensity of gametic selection by determining the competitors involved, which can in turn cause the mating system itself to evolve. We model the bidirectional relationship between gametic selection and mating systems, focusing on variation in female mating frequency (monandry-polyandry) and self-fertilisation (selfing-outcrossing). First, we find that monandry and selfing both reduce the efficiency of gametic selection in removing deleterious alleles. This means that selfing can increase mutation load, in contrast to cases without gametic selection where selfing purges deleterious mutations and decreases mutation load. Second, we explore how mating systems evolve via their effect on gametic selection. By manipulating gametic selection, polyandry can evolve to increase the fitness of the offspring produced. However, this indirect advantage of post-copulatory sexual selection is weak and is likely to be overwhelmed by any direct fitness effects of mating systems. Nevertheless, gametic selection can be potentially decisive for selfing evolution because it significantly reduces inbreeding depression, which favours selfing. Thus, the presence of gametic selection could be a key factor driving selfing evolution.

Metastatic melanoma is associated with a poor prognosis and understanding the genetic features of metastases may enable better treatment strategies. Here, the authors analyse multiple metastases from individual patients finding high levels of heterogeneity in metastases from different organs.

Sex determination is remarkably dynamic; many taxa display shifts in the location of sex-determining loci or the evolution of entirely new sex-determining systems. Predominant theories for why we observe such transitions generally conclude that novel sex-determining systems are favoured by selection if they equalise the sex ratio or increase linkage with a locus that experiences different selection in males versus females. We use population genetic models to extend these theories in two ways: (1) We consider the dynamics of loci very tightly linked to the ancestral sex-determining loci, e.g., within the nonrecombining region of the ancestral sex chromosomes. Variation at such loci can favour the spread of new sex-determining systems in which the heterogametic sex changes (XY to ZW or ZW to XY) and the new sex-determining region is less closely linked (or even unlinked) to the locus under selection. (2) We consider selection upon haploid genotypes either during gametic competition (e.g., pollen competition) or meiosis (i.e., nonmendelian segregation), which can cause the zygotic sex ratio to become biased. Haploid selection can drive transitions between sex-determining systems without requiring selection to act differently in diploid males versus females. With haploid selection, we find that transitions between male and female heterogamety can evolve so that linkage with the sex-determining locus is either strengthened or weakened. Furthermore, we find that sex ratio biases may increase or decrease with the spread of new sex chromosomes, which implies that transitions between sex-determining systems cannot be simply predicted by selection to equalise the sex ratio. In fact, under many conditions, we find that transitions in sex determination are favoured equally strongly in cases in which the sex ratio bias increases or decreases. Overall, our models predict that sex determination systems should be highly dynamic, particularly when haploid selection is present, consistent with the evolutionary lability of this trait in many taxa.

Lower extremity injuries account for over 50% of pedestrian orthopedic injuries in car-to-pedestrian collisions. Pedestrian finite element models are useful tools for studying pedestrian safety, but current models use simplified knee models that exclude potentially important stabilizing knee components. The effect of these stabilizing components in pedestrian impacts is currently unknown. The goal of this study was to develop a detailed lower-extremity model to investigate the effect of these stabilizing components on pedestrian biomechanics. In this study the Global Human Body Model Consortium male 50th percentile pedestrian model lower body was updated to include various stabilizing knee components, enhance geometric anatomical accuracy of previously modeled soft tissue structures, and update hard and soft tissue material models. The original and updated models were compared across 13 validation tests and the updated model reported significantly (p = 0.01) larger CORA scores (0.73 ± 0.15) than the original model (0.56 ± 0.20). To investigate the effect of the new stabilizing knee components the updated model had its stabilizing components severed. The severed and intact models were impacted by the EuroNCAP SUV and family car models at 30 and 40 km/h. The intact and severed models reported nearly identical head impact times, wrap around distances, and lower-extremity injury outcomes in all four impacts, but the stabilizing components reduced the varus knee angle of the secondarily impacted leg by up to 4.9°. The stabilizing components may prevent secondary impacted leg injuries in lower intensity impacts but overall had little effect on pedestrian biomechanical outcomes. [ABSTRACT FROM AUTHOR]

This article examines a distinct trend in illustrated editions of the Heptaméron , which date back to 1698 but become increasingly common starting in the 1860s. Whereas illustrated Heptamérons from the second half of the nineteenth century tend to foreground displays of passion in the nouvelles and foster a nostalgic vision of France's medieval past, around the turn of the twentieth century, they go in a direction that specialists of Marguerite might find surprising. The collection could not be considered pornographic or even obscene by today's standards or those of its time, and if Marguerite foregrounds erotic desire, it is because it is an indelible part of the postlapsarian human condition. However, erotic desire becomes an end in and of itself in illustrated Heptamérons beginning with the fin de siècle. From this point on, the majority of illustrated Heptamérons may be classified as erotica: material designed to provide sexual stimulation but accompanied by more or less lofty artistic ambitions and marketed to wealthy men with bibliophilic inclinations. In other words, there exists alongside the tradition of scholarly editions of the Heptaméron a tradition in which the collection essentially becomes high-class pornography. I will consider what these illustrated editions teach us about erotica in the late nineteenth and early twentieth centuries, as well as about how Marguerite's magnum opus has been understood and received outside of academia. [ABSTRACT FROM AUTHOR]

This study aimed to characterize the risk of people living with HIV (PLHIV) in the UK progressing to pre-specified HIV-associated comorbidities, compared with matched, HIV-negative controls. Primary and secondary care records from the Clinical Practice Research Datalink (CPRD) and linked Hospital Episode Statistics (HES) were used to identify PLHIV, and a matched cohort from the HIV-negative population. Kaplan Meier curves and Cox proportional hazard models were used to evaluate the risk of developing comorbidities including central nervous system (CNS) disorders, end-stage renal disease, osteoporosis, diabetes, cardiovascular disease (CVD), hypertension, stroke and cancer. A total of 2945 PLHIV were matched to a cohort of 5890 HIV-negative controls. PLHIV demonstrated an increased hazard ratio (HR) for time to development of incident sleep disorders, depression, osteoporosis, stroke, cancer and renal disease when compared with their matched HIV-negative control. The HRs for anxiety, hypertension, diabetes and CVD were not significantly increased. PLHIV in the UK were at a higher risk of developing a number of comorbid conditions, highlighting the need for regular attendance of health reviews such as the annual health reviews recommended by the British HIV Associations (BHIVA) quality standard for care, which are currently not uniformly conducted. [ABSTRACT FROM AUTHOR]

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Cette étude propose de réévaluer la Comédie de Mont-de-Marsan, chef-d'œuvre du théâtre profane de Marguerite de Navarre, en se concentrant moins sur le contenu idéologique de la pièce que sur son vocabulaire et son interpellation du spectateur. En traçant le champ lexical du jugement à travers les personnages de la Supersticieuse et la Sage, elle démontre la façon dont la Comédie met en scène l'interdiction biblique de juger son prochain et la difficulté d'obéir à cette interdiction. Le jugement se révèle réflexif: en jugeant le comportement des autres ou même en leur reprochant ce jugement, la Supersticieuse et la Sage se condamnent et témoignent de l'incapacité de l'être humain à gagner le salut par l'adhésion à la doctrine. Le spectateur, invité à juger dès le début de la pièce, est amené à se voir dans ces personnages et à reconnaître sa propre tendance pécheresse à juger. [ABSTRACT FROM AUTHOR]

Rules governing superannuation investments are made with respect to investment-specific risks, rather than overall portfolio risks. In particular, legislation prohibits borrowing except in specific circumstances and on a non-recourse basis. We model the distribution of leveraged portfolio outcomes for a representative investor, accounting for their age-earnings profile, differing taxation of dividends, capital gains and franking credits, and the volatility of equity returns and interest rates. With explicit portfolio modelling, there is no need to categorize specific investments as ‘too risky’ on a stand-alone basis. We show that leverage is likely to enhance retirement outcomes for investors with low risk aversion. [ABSTRACT FROM AUTHOR]

The formation of an Fe(III) precipitate (plaque) on the surface of aquatic plant roots may provide a means of attenuation and external exclusion of metals. Presently, the mechanisms of metal(loid) sequestration at the root surface are unresolved. Accordingly, we investigated the mechanisms of Fe and As attenuation and association on the roots of two common aquatic plant species, Phalaris arundinacea (reed canarygrass) and Typhalatifolia (cattail) using X-ray absorption spectroscopy and X-ray fluorescence microtomography. Iron plaque of both P. arundinacea and T. latifoliaconsist predominantly of hydrated iron oxides (ferrihydrite) with lesser amounts of goethite and minor levels of siderite. Typha latifolia, however, differs from P. arundinacea by having a significant contribution from lepidocrocite as well as a greater proportion of crystalline minerals. Coexistence of goethite and lepidocrocite suggests the presence of chemically diverse microenvironments at the root surface. Arsenic exists as a combination of two sorbed As species, being comprised predominantly of arsenate- (∼82%) with lesser amounts (∼18%) of As-(III)-iron (hydr)oxide complexes. Furthermore, both spatial and temporal correlations between As and Fe on the root surfaces were observed. While the iron (hydr)oxide deposits form a continuous surficial rind around the root, As exists in isolated regions on the exterior and interior of the root. Root surface-associated As generally corresponds to regions of enhanced Fe levels and may therefore occur as a direct consequence of Fe phase heterogeneity and preferential As sorption reactions., Organismic and Evolutionary Biology

The article presents a lesson plan which analyzes the stanza three of the poem "The Star-Spangled Banner," by Francis Scott Key.