Tradeoff breaking as a model of evolutionary transitions in individuality and limits of the fitness-decoupling metaphor

Evolutionary transitions in individuality (ETIs) involve the formation of Darwinian collectives from Darwinian particles. The transition from cells to multicellular life is a prime example. During an ETI, collectives become units of selection in their own right. However, the underlying processes are poorly understood. One observation used to identify the completion of an ETI is an increase in collective-level performance accompanied by a decrease in particle-level performance, for example measured by growth rate. This seemingly counterintuitive dynamic has been referred to as fitness decoupling and has been used to interpret both models and experimental data. Extending and unifying results from the literature, we show that fitness of particles and collectives can never decouple because calculations of fitness performed over appropriate and equivalent time intervals are necessarily the same provided the population reaches a stable collective size distribution. By way of solution, we draw attention to the value of mechanistic approaches that emphasise traits, and tradeoffs among traits, as opposed to fitness. This trait-based approach is sufficient to capture dynamics that underpin evolutionary transitions. In addition, drawing upon both experimental and theoretical studies, we show that while early stages of transitions might often involve tradeoffs among particle traits, later-and critical-stages are likely to involve the rupture of such tradeoffs. Thus, when observed in the context of ETIs, tradeoff-breaking events stand as a useful marker of these transitions

MM and subMM molecular line observations of the southwest lobe of L1551: Evidence of a shell structure

Observations have been made of the southwest outflow lobe of L1551 in several millimeter and submillimeter molecular lines. Maps have been made in the J=3-2 and J=2-1 transitions of CO over areas of 7.5 by 2.5 arc minutes and 5 by 5 arc minutes respectively at UKIRT. More detailed maps have also been made in the J=2-1 CO transition over an area of about 6 by 3.5 arc minutes at the NRAO 12m telescope. Additional observations of the J=4-3 transitions of HCN, HCO(+) abd H(13)CO(+) were made at selected positions. The HC(+) J=4-3 transition was detected at several positions along the outflow axis and at the position of IRS 5. Similarly the HCN J=4-3 transition was detected at the position of IRS 5 and also at a position close to HH29. However, the J=4-3 transition of H(13)CO(+) was bit detected at the position of IRS 5 even through it was observed at the position close to HH29 with a peak corrected antenna temperature of 0.23K at a V(LSR) of 1 km s(-1). The detection of the J=4-3 transitions of both HCO(+) and H(13)CO(+) close to the position of HH29 suggest the presence of very dense gas in this region. LVG analysis of the various molecular lines observed give a kinetic temperature between 10 and 15K and a density from 10(5) to 10(6) cm(-3) at the position of IRS 5 at the ambient cloud velocity. At the position close to HH29 LVG analysis of the CO observations gives a density between 10(3) and 10(4) cm(-3) at a kinetic temperature of 25k for a V(LSR) of 0 km s(-1). To the southwest of HH29 there is a large decrease in both the linewidth and intensity of CO emission. This may be due to the interaction between the outflow and a dense clump of gas which gives rise to HH29. The maps of the CO J=3-2 and CO J=2-1 emission integrated in 3.25 km s intervals show the shell structure postulated by Snell and Schloerb (1985)

Exact and semiclassical approach to a class of singular integral operators arising in fluid mechanics and quantum field theory

A class of singular integral operators, encompassing two physically relevant cases arising in perturbative QCD and in classical fluid dynamics, is presented and analyzed. It is shown that three special values of the parameters allow for an exact eigenfunction expansion; these can be associated to Riemannian symmetric spaces of rank one with positive, negative or vanishing curvature. For all other cases an accurate semiclassical approximation is derived, based on the identification of the operators with a peculiar Schroedinger-like operator.Comment: 12 pages, 1 figure, amslatex, bibtex (added missing label eq.11

Exploring a Plant-Diversity Hypothesis to Explain Helminth Prevalence in Northern Bobwhite in Texas

Helminths, in particular eyeworms (Oxyspirura petrowi), may be a factor influencing northern bobwhite (Colinus virginianus; hereafter, bobwhite) populations in Texas, USA. Mean eyeworm prevalence in Texas appears to be greater in the Rolling Plains (55.1%) than the Rio Grande Plains (16.4%), a pattern generally attributed to possible differences in the occurrence of insects, the intermediate hosts of eyeworms. We explored an alternative hypothesis centered on plant diversity. Many plants possess phytochemicals with anthelmintic properties. Because wild animals suffering from parasitic infestations are capable of self-medicating via diet selection, organisms foraging in diverse communities may be expected to possess lower parasite levels. We predicted that plant diversity would be greater and bobwhite diet more diverse in the Rio Grande Plains than the Rolling Plains, which in turn would potentially expose bobwhites to more plants with anthelmintic properties and therefore result in lower parasite prevalence. We conducted a literature review of plant diversity, anthelmintic plants, and bobwhite diet in Texas to explore this hypothesis. Our results indicated that 1) plant diversity was higher (24–96%), 2) the number of anthelmintic plants greater (33%), and 3) bobwhite diet more diverse (120%) in the Rio Grande Plains compared to the Rolling Plains. We documented a mean (± standard error) eyeworm prevalence of 16.4 ± 7.27% in the Rio Grande Plains (n = 4 sites) and 55.05 ± 2.93% in the Rolling Plains (n = 20 sites). The mean cecal-worm prevalence was documented at 74.8 ± 18.21% in the Rio Grande Plains (n = 5 sites) and 79.79 ± 2.12% in the Rolling Plains (n = 19 sites). Regarding plant diversity, the Rio Grande Plains contained more potential anthelmintic plants (n = 96 species) than the Rolling Plains (n = 72 species). In cross-referencing these plants with the bobwhite diet, we found that 23 plants with possible anthelmintic properties had been documented in the bobwhite diet in the Rio Grande Plains, whereas only 17 such plants were documented in the bobwhite diet in the Rolling Plains. Our study provides circumstantial evidence for the plant-diversity hypothesis and warrants experimental testing

Examining the potential clinical value of curcumin in the prevention and diagnosis of Alzheimer\u27s disease

Curcumin derived from turmeric is well documented for its anti-carcinogenic, antioxidant and anti-inflammatory properties. Recent studies show that curcumin also possesses neuroprotective and cognitive-enhancing properties that may help delay or prevent neurodegenerative diseases, including Alzheimer’s disease (AD). Currently, clinical diagnosis of AD is onerous, and it is primarily based on the exclusion of other causes of dementia. In addition, phase III clinical trials of potential treatments have mostly failed, leaving disease-modifying interventions elusive. AD can be characterised neuropathologically by the deposition of extracellular β amyloid (Aβ) plaques and intracellular accumulation of tau-containing neurofibrillary tangles. Disruptions in Aβ metabolism/clearance contribute to AD pathogenesis. In vitro studies have shown that Aβ metabolism is altered by curcumin, and animal studies report that curcumin may influence brain function and the development of dementia, because of its antioxidant and anti-inflammatory properties, as well as its ability to influence Aβ metabolism. However, clinical studies of curcumin have revealed limited effects to date, most likely because of curcumin’s relatively low solubility and bioavailability, and because of selection of cohorts with diagnosed AD, in whom there is already major neuropathology. However, the fresh approach of targeting early AD pathology (by treating healthy, pre-clinical and mild cognitive impairment-stage cohorts) combined with new curcumin formulations that increase bioavailability is renewing optimism concerning curcumin-based therapy. The aim of this paper is to review the current evidence supporting an association between curcumin and modulation of AD pathology, including in vitro and in vivo studies. We also review the use of curcumin in emerging retinal imaging technology, as a fluorochrome for AD diagnostics

CO J = 3-2 and J = 2-1 spectroscopy and mapping of ten high velocity molecular outflow sources

The authors have mapped high velocity outflows associated with the sources K3-50, CRL 2591, W3, S88, NGC 2264, NGC 2024, S140, G 35.2-0.74, NGC 1333 (HH 7-11), and NGC 1333 (IRAS 1) in the J = 2-1 and J = 3-2 transitions of CO. The line core and wing excitation properties are discussed in detail, and an approximate relation dv/dr ≅ 2.5×10-4n (H2)3/2km s-1 pc-1 determined, whereby most of the nebulae appear to depart considerably from the régime of free-fall collapse, or thermal, turbulent, and rotational stability

Stranded research? Leading finance journals are silent on climate change

Finance research has shaped the modern financial system, influencing investors and market participants directly through research findings and indirectly through teaching and training programmes. Climate change presents major risks to the global financial system as well as new opportunities for investors. Is climate finance an important topic in finance research? We systematically analyse the content of 20,725 articles published in the leading 21 finance journals between January 1998 and June 2015. We find that only 12 articles (0.06%) are related in some way to climate finance. The three elite finance journals (Journal of Finance, Journal of Financial Economics and Review of Financial Studies) did not publish a single article related to climate finance over the 17.5-year period. We repeat our analysis across a sample of 29 elite business journals spanning accounting, economics, management, marketing and operations research, as well as finance. We find a similar dearth of published climate finance research. We consider four possible explanations for this failure of top finance and business journals to engage with climate finance as a research topic. These include methodological constraints and editorial policies. We conclude by arguing why it is critical for climate-related research to be given greater attention and prominence in finance journals

Leadership and decision-making practices in public versus private universities in Pakistan

The goal of this study is to examine differences in leadership and decision-making practices in public and private universities in Pakistan, with a focus on transformational leadership (TL) and participative decision-making (PDM). We conducted semi-structured interviews with 46 deans and heads of department from two public and two private universities in Pakistan. Our findings indicate that leadership and decision-making practices are different in public and private universities. While differences were observed in all six types of TL-behaviour, the following three approaches emerged to be crucial in both public and private universities: (1) articulating a vision, (2) fostering the acceptance of group goals, and (3) high-performance expectations. In terms of PDM, deans and heads of department in public and private universities adopt a collaborative approach. However, on a practical level this approach is limited to teacher- and student-related matters. Overall, our findings suggest that the leadership and decision-making practices in Pakistani public and private universities are transformational and participative in nature

“I am a young immigrant woman doing physics and on top of that I am Muslim”:Identities, intersections, and negotiations

Framed within intersectionality and using science identity as a unit of analysis, in this single case study I explore the barriers, difficulties, and conflicts that Amina, a young Muslim woman, immigrant in Western Europe confronted throughout her trajectory in physics and the ways in which her multiple identities intersected. The main sources of data consisted of three long biographical interviews, which were analyzed through a constant comparative method. The analysis of the data provided insights into how intrapersonal, interpersonal, sociocultural factors, alongside a myriad of experiences nurtured Amina's intersectional identities and what this may mean for Muslim women's participation in physics. The findings are summarized in two main assertions: (a) Amina was confronted with various barriers across her journey in physics with the intersection of religion and gender being the major barrier to her perceived recognition due to cultural expectations, sociopolitical factors, and negative stereotypes and (b) Amina's social class, religion, gender performance, and ethnic status positioned her as Other in various places throughout her trajectory in physics, and consequently hindered her sense of belonging. These findings suggest the urgency and importance of: (a) examining the intersection of science identity with other identities, especially, religion, gender, and ethnicity for the purpose of extrapolating a more comprehensive understanding of how minoritized groups participate in science; (b) rethinking recognition through an explicit intersectionality lens across various geographical and sociopolitical contexts; and (c) transforming physics into a diverse world where multiple ways of being are recognized, where minoritized groups will not have to compartmentalize parts of their identities to exist, and where they can perform their authentic and intersectional identities

Plasma high‐density lipoprotein cargo is altered in Alzheimer's disease and is associated with regional brain volume

Cholesterol levels have been repeatedly linked to Alzheimer's Disease (AD), suggesting that high levels could be detrimental, but this effect is likely attributed to Low-Density Lipoprotein (LDL) cholesterol. On the other hand, High-Density Lipoproteins (HDL) cholesterol levels have been associated with reduced brain amyloidosis and improved cognitive function. However, recent findings have suggested that HDL-functionality, which depends upon the HDL-cargo proteins associated with HDL, rather than HDL levels, appears to be the key factor, suggesting a quality over quantity status. In this report, we have assessed the HDL-cargo (Cholesterol, ApoA-I, ApoA-II, ApoC-I, ApoC-III, ApoD, ApoE, ApoH, ApoJ, CRP, and SAA) in stable healthy control (HC), healthy controls who will convert to MCI/AD (HC-Conv) and AD patients (AD). Compared to HC we observed an increased cholesterol/ApoA-I ratio in AD and HC-Conv, as well as an increased ApoD/ApoA-I ratio and a decreased ApoA-II/ApoA-I ratio in AD. Higher cholesterol/ApoA-I ratio was also associated with lower cortical grey matter volume and higher ventricular volume, while higher ApoA-II/ApoA-I and ApoJ/ApoA-I ratios were associated with greater cortical grey matter volume (and for ApoA-II also with greater hippocampal volume) and smaller ventricular volume. Additionally, in a clinical status-independent manner, the ApoE/ApoA-I ratio was significantly lower in APOE ε4 carriers and lowest in APOE ε4 homozygous. Together, these data indicate that in AD patients the composition of HDL is altered, which may affect HDL functionality, and such changes are associated with altered regional brain volumetric data