Should I stay or should I go? How activity synchronization affects fission decisions

Group-living animals need to deal with conflicting interests to maintain cohesion. When the costs of doing so outweigh the benefits, the group may (temporarily) split into two or more subgroups. Conflicting interests can concern what activity to pursue or the direction of travel. Temporary group separation is a common feature in species with a high degree of fission–fusion dynamics. We investigated the role activity synchronization played in fission decisions in a spider monkey group living in the Otoch Ma'ax Yetel Kooh Nature Reserve, Yucatan, Mexico. For 21 months, we recorded every fission event occurring in the followed subgroup, as well as the subgroup activity. We classified the activity as ‘synchronized’ when at least 75% of subgroup members performed the same activity (resting, foraging, socializing or travelling); otherwise, we classified it as ‘non-synchronized’. We found that fission events occurred more often when the activity was non-synchronized. In addition, when the activity was synchronized, fission events occurred more often when spider monkeys were travelling than when they were engaged in other subgroup activities. Our findings highlight the role of conflicting interests over the activity to pursue and travel direction in fission decisions.

Variation in Plasma Levels of TRAF2 Protein During Development of Squamous Cell Carcinoma of the Oral Tongue

As early detection is crucial for improvement of cancer prognosis, we searched for biomarkers in plasma from individuals who later developed squamous cell carcinoma of the oral tongue (SCCOT) as well as in patients with an already established SCCOT. Levels of 261 proteins related to inflammation and/or tumor processes were measured using the proximity extension assay (PEA) in 179 plasma samples (42 collected before diagnosis of SCCOT with 81 matched controls; 28 collected at diagnosis of SCCOT with 28 matched controls). Statistical modeling tools principal component analysis (PCA) and orthogonal partial least square - discriminant analysis (OPLS-DA) were applied to provide insights into separations between groups. PCA models failed to achieve group separation of SCCOT patients from controls based on protein levels in samples taken prior to diagnosis or at the time of diagnosis. For pre-diagnostic samples and their controls, no significant OPLS-DA model was identified. Potentials for separating pre-diagnostic samples collected up to five years before diagnosis (n = 15) from matched controls (n = 28) were seen in four proteins. For diagnostic samples and controls, the OPLS-DA model indicated that 21 proteins were important for group separation. TNF receptor associated factor 2 (TRAF2), decreased in pre-diagnostic plasma (< 5 years) but increased at diagnosis, was the only protein showing altered levels before and at diagnosis of SCCOT (p-value < 0.05). Taken together, changes in plasma protein profiles at diagnosis were evident, but not reliably detectable in pre-diagnostic samples taken before clinical signs of tumor development. Variation in protein levels during cancer development poses a challenge for the identification of biomarkers that could predict SCCOT development.

Circulating Metabolomics Suggest Neutropenic Fever As a Metabolic Derangement Related to Intestinal Tissue Damage and Gut Dysbiosis

Introduction: Despite antibiotic prophylaxis, most patients with acute myeloid leukemia (AML) develop neutropenic fever (NF) during intensive chemotherapy, suggesting a non-infectious etiology in many cases. In addition, escalated antibiotics used to treat NF increase the risk of Clostridioides difficile infection, promote pathogen colonization, prolong hospitalization, and increase healthcare costs. More effective prevention of NF, preferably using non-antibiotic approaches, is needed. We hypothesized that a longitudinal analysis of the circulating metabolome may reveal novel aspects of NF pathogenesis and identify potential targets for new preventative interventions. Methods: We analyzed 128 longitudinal serum samples from 17 intensively treated adult patients with AML between hospital admission and day 28 of chemotherapy. Samples were collected between 6-8 AM every Mon and Thu. Samples were subjected to ultrahigh performance liquid chromatography-tandem mass spectrometry. Results: All patients developed NF. A total of 1,031 metabolites were identified. Principal components analysis of the circulating metabolome could not resolve individual patients (Fig. 1a). In contrast, pre- vs. post-NF samples were partially clustered (Fig. 1b), suggesting a metabolomic shift associated with NF. After correcting for false discovery, 26 and 27 metabolites were higher in pre- and post-NF samples, respectively (q<0.05, |log fold-change| >1; Fig. 1c). The most significant metabolite that was different between post- and pre-NF samples was citrulline, with a mean concentration ratio of 0.65 between the two groups (q<10-5, Fig. 1c). Citrulline is a known biomarker for total enterocyte mass and its lower levels in post-NF samples indicate intestinal tissue damage as a potential etiology for NF. Another notable metabolite was 3-indoxyl sulfate (3-IS), a tryptophan metabolite and biomarker of gut microbiota diversity and clostridia abundance. 3-IS levels also decreased in post-NF (post vs. pre ratio: 0.45, q=0.02; Fig. 1c), suggesting a protective role for commensal microbiota against NF. Indoles act via the aryl hydrocarbon receptor to repair the intestinal epithelial barrier. Sparse partial least squares discriminant analysis (sPLS-DA) further improved group separation (Fig. 1d). Significantly altered metabolites in the first analysis along with the top 50 metabolites in sPLS-DA were fed into a random forest which generated the final list of 47 metabolites with largest contributions to group separation, including 3-IS and several citrulline metabolites (top 10 metabolites in Table 1). The most frequent metabolites on this list were those in amino acid (n = 17) and lipid (n = 14, including a secondary bile acid) pathways. Conclusions: This first-time analysis of the circulating metabolome in AML patients with NF suggests NF as a metabolic derangement rather than an infectious event in many patients. Augmenting the intestinal epithelium and maintaining a commensal clostridia-rich gut microbiome may help prevent NF. In addition, our list of altered metabolites introduces an unexplored niche for the development of novel, non-antibiotic-based approaches to prevent NF. Figure 1 Figure 1. Disclosures Holtan: Incyte: Consultancy, Research Funding; Generon: Consultancy. Weisdorf: Fate Therapeutics: Research Funding; Incyte: Research Funding.

Density-dependent mating behaviors reduce male mating harassment in locusts

Male mating harassment may occur when females and males do not have the same mating objectives. Communal animals need to manage the costs of male mating harassment. Here, we demonstrate how desert locusts in dense populations reduce such conflicts through behaviors. In transient populations (of solitarious morphology but gregarious behavior), we found that nongravid females occupied separate sites far from males and were not mating, whereas males aggregated on open ground (leks), waiting for gravid females to enter the lekking sites. Once a male mounted a gravid female, no other males attacked the pair; mating pairs were thereby protected during the vulnerable time of oviposition. In comparison, solitarious locusts displayed a balanced sex ratio in low-density populations, and females mated irrespective of their ovarian state. Our results indicate that the mating behaviors of desert locusts are density dependent and that sex-biased behavioral group separation may minimize the costs of male mating harassment and competition.

Extracting Robust Biomarkers From Multichannel EEG Time Series Using Nonlinear Dimensionality Reduction Applied to Ordinal Pattern Statistics and Spectral Quantities

In this study, ordinal pattern analysis and classical frequency-based EEG analysis methods are used to differentiate between EEGs of different age groups as well as individuals. As characteristic features, functional connectivity as well as single-channel measures in both the time and frequency domain are considered. We compare the separation power of each feature set after nonlinear dimensionality reduction using t-distributed stochastic neighbor embedding and demonstrate that ordinal pattern-based measures yield results comparable to frequency-based measures applied to preprocessed data, and outperform them if applied to raw data. Our analysis yields no significant differences in performance between single-channel features and functional connectivity features regarding the question of age group separation.

El conocimiento de la adolescencia y su implicación en la práctica docente.

Knowing the adolescent is necessary in every teaching practice. We cannot see the student and the adolescent as if they were two different boxes in which we must fill them with knowledge, as if they were two entities isolated from each other. By knowing the students' individuality, we can identify a series of individual, family, social, attitudinal factors etc., which will give us many tools to improve our work in the classroom. Emotional and psychological changes, the search for personal identity, acceptance in a group, separation from parents, among other situations, are important aspects for the development of adolescence. That is why in this article it offers an analysis on adolescence, to know the changes that students present in this stage, as well as factors of individual, family and social order that will influence the student remarkably; and finally, a series of points to consider in our teaching process as the result of this analysis.

Vavilovia formosa rhizobia symbionts belong to Rhizobium leguminosarum bv. viciae species, but form a separate group within it

Ecological isolation, group separation of hkg and sym genes, along with the results of the sterile tube test demonstrate that symbionts of V. formosa belong to R. leguminosarum bv. viciae species, but form a separate group within it.

Instrumental neutron activation analysis of lanthanides and coexisting elements in monazite samples and group separation using synthesized inorganic ion exchangers

Samples of Egyptian monazite ore obtained from black sand of Abu-Khashaba, Rashied (Rosetta) area on the Mediterranean Sea coast were analyzed for some lanthanides and coexisting elements using instrumental neutron activation analysis (INAA). The analyses were carried out qualitatively and quantitatively for the elements Ce, Nd, Eu, Gd, Tb, Yb and Sc, La as well as the accompanying elements Co, Cr, Fe, Hf, Nb, Zn, Zr in addition to the actinides Th and U; whereas after relatively longer decay time the following lanthanide elements were analyzed: Ce, Nd, Eu, Gd, Tb, Yb and Sc, beside the accompanying elements Co, Cr, Fe, Hf, Nb, Zn, Zr and Th. Two certified reference materials (CRM) were used in this study. For sorption studies, radioactive isotopes 141Ce, 160Tb, 169Yb, 95Zr, 181Hf, and 95Nb were prepared by neutron irradiation to trace the adsorption behaviors of their corresponding elements under certain conditions. Furthermore, radiochemical separation of the analyzed elements in the irradiated monazite samples in sulfuric acid solutions was carried out. Ion exchange technique was applied under static and dynamic conditions and the employed inorganic ion exchangers were locally synthesized and characterized using FT-IR and scanning electron microscopy (SEM) tools. Good group separation of the analyzed lanthanide elements from the accompanying elements was achieved.

Hydroxyl Group Separation Distances in Anti-Freeze Compounds and Their Effects on Ice Nucleation

Since the discovery of biological antifreeze glycoproteins (AFGPs), which can inhibit ice nucleation, there has been considerable interest in understanding their mechanisms and mimicking them in synthetic polymers. In this study, we used molecular dynamics simulations of modified polyvinyl alcohol (PVA) compounds to show that the hydroxyl (OH) group distance is a key factor in whether certain compounds promote or inhibit ice nucleation. A hydroxyl distance smaller than ~2.8 Å but greater than ~7.1 Å in modified PVA (MPVA) compounds was associated with the promotion of ice nucleation, while a hydroxyl group separation distance of approximately ~5.0 Å was correlated with a delay in ice nucleation, owing to changes in the energy of the system. Thus, these results may help explain some of the mechanisms of current known anti-freeze compounds and may have implications for designing new anti-freeze compounds in the future.