Convergence, Hemiplasy, and Correlated Evolution Impact Morphological Diversity Related to a Web-Less Lifestyle in the Two-Clawed Spiders

Traits that independently evolve many times are important for testing hypotheses about correlated evolution and understanding the forces shaping biodiversity. However, population genetics processes can cause hemiplasies (traits determined by genes whose topologies do not match the species tree), leading to a false impression of convergence (homoplasy) and potentially misleading inferences of correlated evolution. Discerning between homoplasies and hemiplasies can be important in cases of rapid radiations and clades with many gene tree incongruences. Here, focusing on two-clawed spiders (Dionycha) and close relatives, we evaluate if the observed distribution of characters related to a web-less lifestyle could be better explained as synapomorphies, homoplasies, or hemiplasies. We find that, although there are several convergences, hemiplasies are also sometimes probable. We discuss how these hemiplasies could affect inferences about correlation and causal relationship of traits. Understanding when and where in the tree of life hemiplasy could have happened is important, preventing false inference of convergent evolution. Furthermore, this understanding can provide alternative hypotheses that can be tested with independent data. Using traits related to the climbing ability of spiders we show that, when hemiplasy is unlikely, adequate model testing can be used to better understand correlated evolution, and propose hypotheses to be tested using controlled behavioral and mechanical experiments.Fil: Azevedo, Guilherme H. F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Bougie, Tierney. San Diego State University; Estados UnidosFil: Carboni, Martín Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Hedin, Marshal. San Diego State University; Estados UnidosFil: Ramirez, Martin Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

Effects of dimethyl sulfoxide on the globally ischemic heart: Possible general relevance to hypothermic organ preservation

Isolated perfused rabbit hearts were made globally ischemic for 2 hr, then reperfused. For 5 min before and after ischemia hearts were perfused with hypothermic (20 or 27 [deg]C), hypoxic, substrate-free cardioplegic solutions, some of which contained 70 mM dimethyl sulfoxide. Postischemic ventricular pressure development, spontaneous heart rate, coronary flow, lactate dehydrogenase release, tissue Ca2+ content, and in vitro mitochondrial oxidative phosphorylation were used to evaluate the protective effects of the various solutions. Aside from the expected observations that cold cardioplegia lessens ischemic damage, we found that dimethyl sulfoxide gave no indication that it exacerbated ischemic damage or lessened the protection afforded by cardioplegia. We also found that, compared to values measured in comparable drug-free treated hearts, dimethyl sulfoxide significantly improved mitochondrial State 3 respiratory rates, respiratory control, and oxidative phosphorylation rates, and essentially prevented mitochondrial changes due to ischemia and reperfusion. We propose that dimethyl sulfoxide may act as a "scavenger" of cytotoxic free radicals, many of which are known to be generated by mitochondria during reoxygenation. Since hypoxia, ischemia, and reoxygenation are common accompaniments of most organ preservation protocols, we suggest that low concentrations of dimethyl sulfoxide might serve as a useful adjunct to organ preservation in the nonfrozen state, when cryoprotective concentrations are not needed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24063/1/0000315.pd

Discovery of a Dust Sorting Process on Boulders Near the Reiner Gamma Swirl on the Moon

In a database of lunar fractured boulders (Rüsch & Bickel, 2023, https://doi.org/10.3847/psj/acd1ef), we found boulders with reflectance features dissimilar to previously known morphologies. We performed a photo-geologic investigation and determined that the features correspond to a dust mantling on top of boulders with a unique photometric behavior. We next performed a photometric model inversion on the dust mantling using Bayesian inference sampling. Modeling indicates that the dust photometric anomaly is most likely due to a reduced opposition effect, whereas the single scattering albedo is not significantly different from that of the nearby background regolith. This implies a different structure of the dust mantling relative to the normal regolith. We identified and discussed several potential processes to explain the development of such soil. None of these mechanisms can entirely explain the multitude of observational constraints unless evoking anomalous boulder properties. Further study of these boulders can shed light on the workings of a natural dust sorting process potentially involving dust dynamics, a magnetic field, and electrostatic dust transport. The presence of these boulders appears to be limited to the Reiner K crater near the Reiner Gamma magnetic and photometric anomaly. This close spatial relationship further highlights that poorly understood processes occur in this specific region of the Moon

Comparison of three video laryngoscopy devices to direct laryngoscopy for intubating obese patients: a randomized controlled trial

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Sexual behaviour does not reflect HIV-1 prevalence differences: a comparison study of Zimbabwe and Tanzania

Background Substantial heterogeneity in HIV prevalence has been observed within sub-Saharan Africa. It is not clear which factors can explain these differences. Our aim was to identify risk factors that could explain the large differences in HIV-1 prevalence among pregnant women in Harare, Zimbabwe, and Moshi, Tanzania. Methods Cross-sectional data from a two-centre study that enrolled pregnant women in Harare (N = 691) and Moshi (N = 2654) was used. Consenting women were interviewed about their socio-demographic background and sexual behaviour, and tested for presence of sexually transmitted infections and reproductive tract infections. Prevalence distribution of risk factors for HIV acquisition and spread were compared between the two areas. Results The prevalence of HIV-1 among pregnant women was 26% in Zimbabwe and 7% in Tanzania. The HIV prevalence in both countries rises constantly with age up to the 25-30 year age group. After that, it continues to rise among Zimbabwean women, while it drops for Tanzanian women. Risky sexual behaviour was more prominent among Tanzanians than Zimbabweans. Mobility and such infections as HSV-2, trichomoniasis and bacterial vaginosis were more prevalent among Zimbabweans than Tanzanians. Reported male partner circumcision rates between the two countries were widely different, but the effect of male circumcision on HIV prevalence was not apparent within the populations. Conclusions The higher HIV-1 prevalence among pregnant women in Zimbabwe compared with Tanzania cannot be explained by differences in risky sexual behaviour: all risk factors tested for in our study were higher for Tanzania than Zimbabwe. Non-sexual transmission of HIV might have played an important role in variation of HIV prevalence. Male circumcision rates and mobility could contribute to the rate and extent of spread of HIV in the two countries

Review of recent experimental progresses in Foundations of Quantum Mechanics and Quantum Information obtained in Parametric Down Conversion Experiments at IENGF

We review some recent experimental progresses concerning Foundations of Quantum Mechanics and Quantum Information obtained in Quantum Optics Laboratory "Carlo Novero" at IENGF. More in details, after a short presentation of our polarization entangled photons source (based on precise superposition of two Type I PDC emission) and of the results obtained with it, we describe an innovative double slit experiment where two degenerate photons produced by PDC are sent each to a specific slit. Beyond representing an interesting example of relation between visibility of interference and "welcher weg" knowledge, this configuration has been suggested for testing de Broglie-Bohm theory against Standard Quantum Mechanics. Our results perfectly fit SQM results, but disagree with dBB predictions. Then, we discuss a recent experiment addressed to clarify the issue of which wave-particle observables are really to be considered when discussing wave particle duality. This experiments realises the Agarwal et al. theoretical proposal, overcoming limitations of a former experiment. Finally, we hint to the realization of a high-intensity high-spectral-selected PDC source to be used for quantum information studies

Regulatory objectivity in action: Mild cognitive impairment and the collective production of uncertainty

In this paper, we investigate recent changes in the definition and approach to Alzheimer’s disease brought about by growing clinical, therapeutic and regulatory interest in the prodromal or preclinical aspects of this condition. In the last decade, there has been an increased interest in the biomolecular and epidemiological characterization of pre-clinical dementia. It is argued that early diagnosis of dementia, and particularly of Alzheimer‘s disease, will facilitate the prevention of dementing processes and lower the prevalence of the condition in the general population. The search for a diagnostic category or biomarker that would serve this purpose is an ongoing but problematic endeavour for research and clinical communities in this area. In this paper, we explore how clinical and research actors, in collaboration with regulatory institutions and pharmaceutical companies, come to frame these domains as uncertainties and how they re-deploy uncertainty in the ‘collective production’ of new diagnostic conventions and bioclinical standards. While drawing as background on ethnographic, documentary and interview data, the paper proposes an in-depth, contextual analysis of the proceedings of an international meeting organized by the Peripheral and Central Nervous System Drug Advisory Committee of the US Food and Drug Administration to discuss whether or not a particular diagnostic convention — mild cognitive impairment — exists and how best it ought to be studied. Based on this analysis we argue that the deployment of uncertainty is reflexively implicated in bioclinical collectives’ search for rules and conventions, and furthermore that the collective production of uncertainty is central to the ‘knowledge machinery’ of regulatory objectivity