On the importance of balancing selection in plants

This is the peer reviewed version of the following article: Delph, L. F. and Kelly, J. K. (2014), On the importance of balancing selection in plants. New Phytol, 201: 45–56. doi:10.1111/nph.12441, which has been published in final form at http://doi.org/10.1111/nph.12441. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Balancing selection refers to a variety of selective regimes that maintain advantageous genetic diversity within populations. We review the history of the ideas regarding the types of selection that maintain such polymorphism in flowering plants, notably heterozygote advantage, negative frequency-dependent selection, and spatial heterogeneity. One shared feature of these mechanisms is that whether an allele is beneficial or detrimental is conditional on its frequency in the population. We highlight examples of balancing selection on a variety of discrete traits. These include the well-referenced case of self-incompatibility and recent evidence from species with nuclear-cytoplasmic gynodioecy, both of which exhibit trans-specific polymorphism, a hallmark of balancing selection. We also discuss and give examples of how spatial heterogeneity in particular, which is often thought unlikely to allow protected polymorphism, can maintain genetic variation in plants (which are rooted in place) as a result of microhabitat selection. Lastly, we discuss limitations of the protected polymorphism concept for quantitative traits, where selection can inflate the genetic variance without maintaining specific alleles indefinitely. We conclude that while discrete-morph variation provides the most unambiguous cases of protected polymorphism, they represent only a fraction of the balancing selection at work in plants

Influential Article Review - Evaluation of the Quality of Health Services: Comparative Analysis of the Groups of Patients

This paper examines healthcare. We present insights from a highly influential paper. Here are the highlights from this paper: The purpose of this study is to examine the effects of healthcare service quality (HEALTHQUAL) measurement items. First, the proposed measurement items for HEALTHQUAL were tested using data collected from a hospital in South Korea with more than 500 beds. The data set included 365 patients and 232 public respondents. ANOVA and t-tests were used to perform a comparative analysis of HEALTHQUAL measurement items among three patient treatment groups (inpatients, outpatients, and family members of patients in the emergency room) and between the patient and general public groups. The results indicated significant differences among measurement items of HEALTHQUAL depending on the type of patient treatment, while there were no significant differences among measurement items of HEALTHQUAL between patients and the public. For our overseas readers, we then present the insights from this paper in Spanish, French, Portuguese, and German

Adolescent drinking, social identity, and parenting for safety : Perspectives from Australian adolescents and parents

We explored young people and parents' views on adolescent drinking and safety in the locations where drinking may occur. Focus groups with adolescents and parents showed that many believed adolescent drinking and drunkenness is normative. Younger adolescents had more negative views of adolescent drinkers than their older peers. Adolescent drinking occurred in private settings and parents made decisions about allowing their adolescent children to attend social events based on the level of safety attributed to the location. If adolescent drinking was likely then home was the preferred location as it provided scope for risk minimisation. Positive portrayals of non-drinking adolescents and information to assist parents' decision-making are needed

Postmenopausal Women With Greater Paracardial Fat Have More Coronary Artery Calcification Than Premenopausal Women: The Study of Women's Health Across the Nation (SWAN) Cardiovascular Fat Ancillary Study.

BackgroundVolumes of paracardial adipose tissue (PAT) and epicardial adipose tissue (EAT) are greater after menopause. Interestingly, PAT but not EAT is associated with estradiol decline, suggesting a potential role of menopause in PAT accumulation. We assessed whether volumes of heart fat depot (EAT and PAT) were associated with coronary artery calcification (CAC) in women at midlife and whether these associations were modified by menopausal status and estradiol levels.Methods and resultsEAT and PAT volumes and CAC were measured using electron beam computed tomography scans. CAC was evaluated as (1) the presence of CAC (CAC Agatston score ≥10) and (2) the extent of any CAC (log CAC Agatston score >0). The study included 478 women aged 50.9 years (58% pre- or early perimenopausal, 10% late perimenopausal, and 32% postmenopausal). EAT was significantly associated with CAC measures, and these associations were not modified by menopausal status or estradiol. In contrast, associations between PAT and CAC measures were modified by menopausal status (interaction-P≤0.01). Independent of study covariates including other adiposity measures, each 1-SD unit increase in log PAT was associated with 102% higher risk of CAC presence (P=0.04) and an 80% increase in CAC extent (P=0.008) in postmenopausal women compared with pre- or early perimenopausal women. Additional adjustment for estradiol and hormone therapy attenuated these differences. Moreover, the association between PAT and CAC extent was stronger in women with lower estradiol levels (interaction P=0.004).ConclusionsThe findings suggest that PAT is a potential menopause-specific coronary artery disease risk marker, supporting the need to monitor and target this fat depot for intervention in women at midlife

Sex-specific natural selection on SNPs in Silene latifolia

Selection that acts in a sex-specific manner causes the evolution of sexual dimorphism. Sex-specific phenotypic selection has been demonstrated in many taxa and can be in the same direction in the two sexes (differing only in magnitude), limited to one sex, or in opposing directions (antagonistic). Attempts to detect the signal of sex-specific selection from genomic data have confronted numerous difficulties. These challenges highlight the utility of “direct approaches,” in which fitness is predicted from individual genotype within each sex. Here, we directly measured selection on Single Nucleotide Polymorphisms (SNPs) in a natural population of the sexually dimorphic, dioecious plant, Silene latifolia. We measured flowering phenotypes, estimated fitness over one reproductive season, as well as survival to the next year, and genotyped all adults and a subset of their offspring for SNPs across the genome. We found that while phenotypic selection was congruent (fitness covaried similarly with flowering traits in both sexes), SNPs showed clear evidence for sex-specific selection. SNP-level selection was particularly strong in males and may involve an important gametic component (e.g., pollen competition). While the most significant SNPs under selection in males differed from those under selection in females, paternity selection showed a highly polygenic tradeoff with female survival. Alleles that increased male mating success tended to reduce female survival, indicating sexual antagonism at the genomic level. Perhaps most importantly, this experiment demonstrates that selection within natural populations can be strong enough to measure sex-specific fitness effects of individual loci

Intrathecal enzyme replacement for Hurler syndrome: biomarker association with neurocognitive outcomes.

PurposeAbnormalities in cerebrospinal fluid (CSF) have been reported in Hurler syndrome, a fatal neurodegenerative lysosomal disorder. While no biomarker has predicted neurocognitive response to treatment, one of these abnormalities, glycosaminoglycan nonreducing ends (NREs), holds promise to monitor therapeutic efficacy. A trial of intrathecal enzyme replacement therapy (ERT) added to standard treatment enabled tracking of CSF abnormalities, including NREs. We evaluated safety, biomarker response, and neurocognitive correlates of change.MethodsIn addition to intravenous ERT and hematopoietic cell transplantation, patients (N = 24) received intrathecal ERT at four peritransplant time points; CSF was evaluated at each point. Neurocognitive functioning was quantified at baseline, 1 year, and 2 years posttransplant. Changes in CSF biomarkers and neurocognitive function were evaluated for an association.ResultsOver treatment, there were significant decreases in CSF opening pressure, biomarkers of disease activity, and markers of inflammation. Percent decrease in NRE from pretreatment to final intrathecal dose posttransplant was positively associated with percent change in neurocognitive score from pretreatment to 2 years posttransplant.ConclusionIntrathecal ERT was safe and, in combination with standard treatment, was associated with reductions in CSF abnormalities. Critically, we report evidence of a link between a biomarker treatment response and neurocognitive outcome in Hurler syndrome

Museums, games, and historical imagination: student responses to a games-based experience at the Australian National Maritime Museum

Digital games feature prominently in discussions concerning the ways museums might reimagine themselves—and best serve their audiences—in an increasingly digital age. Questions are increasingly asked about the opportunities various games might provide to foster historical imagination, and, in this process, contribute to the curation, construction and dissemination of knowledge: goals central to the work of modern museums. This paper reports on the experiences and perceptions of three groups of year 9 students (aged 14-15) as they engaged with one purpose built digital game—called The Voyage— at the Australian National Maritime Museum in 2015. The researchers sought students’ feedback on the strengths, weakness and possibilities associated with using games in museum contexts (rather than at home, or at school). In presenting students’ perspectives and their associated recommendations, the paper provides vital end-user input into considerations about how museums might maximize the potential of digital games, to enhance historical awareness and understanding, build links to formal curriculum, and strengthen partnerships between schools and museums

Space Shuttle Orbiter Structures and Mechanisms

The Space Shuttle Orbiter has performed exceptionally well over its 30 years of flight experience. Among the many factors behind this success were robust, yet carefully monitored, structural and mechanical systems. From highlighting key aspects of the design to illustrating lessons learned from the operation of this complex system, this paper will attempt to educate the reader on why some subsystems operated flawlessly and why specific vulnerabilities were exposed in others. Specific areas to be covered will be the following: high level configuration overview, primary and secondary structure, mechanical systems ranging from landing gear to the docking system, and windows

The role of human milk nutrients in preventing necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is an intestinal disease that primarily impacts preterm infants. The pathophysiology of NEC involves a complex interplay of factors that result in a deleterious immune response, injury to the intestinal mucosa, and in its most severe form, irreversible intestinal necrosis. Treatments for NEC remain limited, but one of the most effective preventative strategies for NEC is the provision of breast milk feeds. In this review, we discuss mechanisms by which bioactive nutrients in breast milk impact neonatal intestinal physiology and the development of NEC. We also review experimental models of NEC that have been used to study the role of breast milk components in disease pathophysiology. These models are necessary to accelerate mechanistic research and improve outcomes for neonates with NEC