327 research outputs found
The emergence of performance trade-offs during local adaptation: insights from experimental evolution
Environmental heterogeneity is considered a general explanation for phenotypic diversification, particularly when heterogeneity causes populations to diverge via local adaptation. Performance trade-offs, such as those stemming from antagonistic pleiotropy, are thought to contribute to the maintenance of diversity in this scenario. Specifically, alleles that promote adaptation in one environment are expected to promote maladaptation in alternative environments. Contrary to this expectation, however, alleles that underlie locally adaptive traits often fail to exhibit fitness costs in alternative environments. Here, we attempt to explain this paradox by reviewing the results of experimental evolution studies, including a new one of our own, that examined the evolution of trade-offs during adaptation to homogeneous versus heterogeneous environments. We propose that when pleiotropic effects vary, whether or not trade-offs emerge among diverging populations will depend critically on ecology. For example, adaptation to a locally homogeneous environment is more likely to occur by alleles that are antagonistically pleiotropic than adaptation to a locally heterogeneous environment, simply because selection is blind to costs associated with environments that are not experienced locally. Our literature review confirmed the resulting prediction that performance trade-offs were more likely to evolve during selection in homogeneous than heterogeneous environments. The nature of the environmental heterogeneity (spatial versus temporal) and the length of the experiment also contributed in predictable ways to the likelihood that performance trade-offs evolved
A Look Back, A Path Forward: Moving Toward Diversity and Inclusion in Cardiovascular Society Presidents
Despite the number of female cardiologists increasing over time, women comprise only <15% of practicing cardiologists worldwide. Women cardiologists are less likely to be full professors, receive research funding, or have a registered clinical trial. Although there has been an increase in women authors of cardiovascular scientific publications over the past 40 years, women are still less likely to be first or senior authors, and they are underrepresented on cardiovascular journal editorial boards. It is well known that women hold few departmental leadership positions in medicine—they are less often cardiology division chiefs or fellowship program directors, and this holds true even in specialties that are female dominated. Additionally, there is a dearth of women and men from diverse backgrounds. Black people comprise 13% of the U.S. population but represent only 2% of cardiologists. Black cardiologists are underrepresented in leadership roles, as well as at the level of full professor. Similarly, only 2% of practicing cardiologists are Hispanic or Latino, and Indigenous people are underrepresented in both medicine and cardiology
Influência de práticas culturais e da resistência genética na intensidade do cancro da haste e produção de soja no Cerrado
Os efeitos de práticas culturais e resistência genética na intensidade ao cancro-da-haste da soja (Diaporthe phaseolorum f.sp. meridionalis - Dpm) foram examinados na safra 1995-96 em áreas de produção comercial, que haviam sido severamente atacadas na safra anterior (1994-95). Um experimento investigou os efeitos de cultivo mínimo (MT) e do plantio direto (NT) no desenvolvimento da doença e produtividade das cultivares FT-Cristalina e FT-Seriema. Em outro experimento, semeado em plantio direto, estudou-se o efeito da densidade de plantas (8, 15, 21 e 36 plantas/m) no desenvolvimento da doença e produtividade das cvs. FT-Cristalina (suscetivel), FT- 101 (moderadamente resistente) e FT-104 (resistente). Incidência e severidade da doença foram menores em NT do que em MT. A produtividade aumentou no sistema NT (23% para ‘FT-Cristalina’ e 14% para ‘FT-Seriema’), comparada com as produtividades em MT. As curvas de progresso da doença foram melhor descritas pelos mo- delos de Gompertz e logístico. A severidade do cancro aumentou pro- porcionalmente ao aumento das densidades de plantio nas cvs. suscetível e moderadamente resistente. No final do ciclo, 100% das plantas da cv. FT-Cristalina estavam infetadas por Dpm, em todas as densidades de plantio. Níveis intermediários de doença foram observa- dos na cv. FT-101, enquanto apenas níveis muito baixos de doença ocorreram na cv. FT-104. Estabeleceu-se uma correlação negativa entre severidade de cancro-da-haste e produção. Algumas das práticas estudadas demonstraram potential para aplicação direta no controle da doença, e poderiam ser combinadas considerando-se seus efeitos aditivos.Field experiments were conducted in the 1995-96 soybean (Glycine max) growing season to evaluate the effects of cultural practices and host genetic resistance on the intensity of soybean stem canker, caused by Diaporthe phaseolorum f.sp. meridionalis (Dpm). Experiments were conducted in a commercial field severely infected in the previous (1994-95) season. In one study, minimum tillage (MT) and no-tillage (NT) cropping systems were investigated for their effects on disease development and on plant yields in cvs. FT- Cristalina (susceptible) and FT-Seriema (moderately resistant). Another study evaluated the effects of plant densities (8, 15, 21 and 36 plants/m) on disease development in cvs. FT-Cristalina, FT-101 (moderately resistant) and FT-104 (resistant). Disease incidence and severity were consistently lower in NT than in MT, and plant yields were increased by 23% and 14% in the NT system for the susceptible and moderately resistant cultivars, respectively, compared to the yields in the MT system. The Gompertz and Logistic models described well the disease progress curves in all situations. For both susceptible and moderately resistant cultivars, disease severity increased proportionately to the increase in plant densities. At the end of the season, 100% of the plants of cv. FT-Cristalina were infected by Dpm, at all plant densities. Disease levels on cv. FT-101 were intermediate while only very low disease levels were recorded on cv. FT-104. There was a consistent negative correlation between stem canker severity and yield. Some practices demonstrated potential for direct application in disease control, and could be combined considering their additive effects
Clinical Profiles, Outcomes, and Sex Differences of Patients With STEMI: Findings From the NORIN-STEMI Registry
Background: Low- and middle-income countries account for most of the global burden of coronary artery disease. There is a paucity of data regarding epidemiology and outcomes for ST-segment elevation myocardial infarction (STEMI) patients in these regions. Objectives: The authors studied the contemporary characteristics, practice patterns, outcomes, and sex differences in patients with STEMI in India. Methods: NORIN-STEMI (North India ST-Segment Elevation Myocardial Infarction Registry) is an investigator-initiated prospective cohort study of patients presenting with STEMI at tertiary medical centers in North India. Results: Of 3,635 participants, 16% were female patients, one-third were <50 years of age, 53% had a history of smoking, 29% hypertension, and 24% diabetes. The median time from symptom onset to coronary angiography was 71 hours; the majority (93%) presented first to a non-percutaneous coronary intervention (PCI)-capable facility. Almost all received aspirin, statin, P2Y12 inhibitors, and heparin on presentation; 66% were treated with PCI (98% femoral access) and 13% received fibrinolytics. The left ventricular ejection fraction was <40% in 46% of patients. The 30-day and 1-year mortality rates were 9% and 11%, respectively. Compared with male patients, female patients were less likely to receive PCI (62% vs 73%; P < 0.0001) and had a more than 2-fold greater 1-year mortality (22% vs 9%; adjusted HR: 2.1; 95% CI: 1.7-2.7; P <0.001). Conclusions: In this contemporary registry of patients with STEMI in India, female patients were less likely to receive PCI after STEMI and had a higher 1-year mortality compared with male patients. These findings have important public health implications, and further efforts are required to reduce these gaps
Physics of Solar Prominences: I - Spectral Diagnostics and Non-LTE Modelling
This review paper outlines background information and covers recent advances
made via the analysis of spectra and images of prominence plasma and the
increased sophistication of non-LTE (ie when there is a departure from Local
Thermodynamic Equilibrium) radiative transfer models. We first describe the
spectral inversion techniques that have been used to infer the plasma
parameters important for the general properties of the prominence plasma in
both its cool core and the hotter prominence-corona transition region. We also
review studies devoted to the observation of bulk motions of the prominence
plasma and to the determination of prominence mass. However, a simple inversion
of spectroscopic data usually fails when the lines become optically thick at
certain wavelengths. Therefore, complex non-LTE models become necessary. We
thus present the basics of non-LTE radiative transfer theory and the associated
multi-level radiative transfer problems. The main results of one- and
two-dimensional models of the prominences and their fine-structures are
presented. We then discuss the energy balance in various prominence models.
Finally, we outline the outstanding observational and theoretical questions,
and the directions for future progress in our understanding of solar
prominences.Comment: 96 pages, 37 figures, Space Science Reviews. Some figures may have a
better resolution in the published version. New version reflects minor
changes brought after proof editin
System Size and Energy Dependence of Jet-Induced Hadron Pair Correlation Shapes in Cu+Cu and Au+Au Collisions at sqrt(s_NN) = 200 and 62.4 GeV
We present azimuthal angle correlations of intermediate transverse momentum
(1-4 GeV/c) hadrons from {dijets} in Cu+Cu and Au+Au collisions at sqrt(s_NN) =
62.4 and 200 GeV. The away-side dijet induced azimuthal correlation is
broadened, non-Gaussian, and peaked away from \Delta\phi=\pi in central and
semi-central collisions in all the systems. The broadening and peak location
are found to depend upon the number of participants in the collision, but not
on the collision energy or beam nuclei. These results are consistent with sound
or shock wave models, but pose challenges to Cherenkov gluon radiation models.Comment: 464 authors from 60 institutions, 6 pages, 3 figures, 2 tables.
Submitted to Physical Review Letters. Plain text data tables for the points
plotted in figures for this and previous PHENIX publications are (or will be)
publicly available at http://www.phenix.bnl.gov/papers.htm
Prospects for Studies of Stellar Evolution and Stellar Death in the JWST Era
I review the prospects for studies of the advanced evolutionary stages of
low-, intermediate- and high-mass stars by the JWST and concurrent facilities,
with particular emphasis on how they may help elucidate the dominant
contributors to the interstellar dust component of galaxies. Observations
extending from the mid-infrared to the submillimeter can help quantify the
heavy element and dust species inputs to galaxies from AGB stars. JWST's MIRI
mid-infrared instrument will be so sensitive that observations of the dust
emission from individual intergalactic AGB stars and planetary nebulae in the
Virgo Cluster will be feasible. The Herschel Space Observatory will enable the
last largely unexplored spectral region, the far-IR to the submillimeter, to be
surveyed for new lines and dust features, while SOFIA will cover the wavelength
gap between JWST and Herschel, a spectral region containing important fine
structure lines, together with key water-ice and crystalline silicate bands.
Spitzer has significantly increased the number of Type II supernovae that have
been surveyed for early-epoch dust formation but reliable quantification of the
dust contributions from massive star supernovae of Type II, Type Ib and Type Ic
to low- and high-redshift galaxies should come from JWST MIRI observations,
which will be able to probe a volume over 1000 times larger than Spitzer.Comment: 24 pages, 19 figures. To appear in `Astrophysics in the Next Decade:
JWST and Concurrent Facilities' (JWST Conference Proceedings), edited by H.
A. Thronson, M. Stiavelli and A. G. G. M. Tielens; Springer Series:
Astrophysics and Space Science Proceeding
Comment on Spracklandus Hoser, 2009 (Reptilia, Serpentes, ELAPIDAE): request for confirmation of the availability of the generic name and for the nomenclatural validation of the journal in which it was published
Primordial Nucleosynthesis for the New Cosmology: Determining Uncertainties and Examining Concordance
Big bang nucleosynthesis (BBN) and the cosmic microwave background (CMB) have
a long history together in the standard cosmology. The general concordance
between the predicted and observed light element abundances provides a direct
probe of the universal baryon density. Recent CMB anisotropy measurements,
particularly the observations performed by the WMAP satellite, examine this
concordance by independently measuring the cosmic baryon density. Key to this
test of concordance is a quantitative understanding of the uncertainties in the
BBN light element abundance predictions. These uncertainties are dominated by
systematic errors in nuclear cross sections. We critically analyze the cross
section data, producing representations that describe this data and its
uncertainties, taking into account the correlations among data, and explicitly
treating the systematic errors between data sets. Using these updated nuclear
inputs, we compute the new BBN abundance predictions, and quantitatively
examine their concordance with observations. Depending on what deuterium
observations are adopted, one gets the following constraints on the baryon
density: OmegaBh^2=0.0229\pm0.0013 or OmegaBh^2 = 0.0216^{+0.0020}_{-0.0021} at
68% confidence, fixing N_{\nu,eff}=3.0. Concerns over systematics in helium and
lithium observations limit the confidence constraints based on this data
provide. With new nuclear cross section data, light element abundance
observations and the ever increasing resolution of the CMB anisotropy, tighter
constraints can be placed on nuclear and particle astrophysics. ABRIDGEDComment: 54 pages, 20 figures, 5 tables v2: reflects PRD version minor changes
to text and reference
- …