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Among animals, humans stand out in their consummate propensity to self-induce altered states of mind. Archaeology, history and ethnography show these activities have taken place since the beginnings of civilization, yet their role in the emergence and evolution of the human mind itself remains debatable. The means through which modern humans actively alter their experience of self and reality frequently depend on psychoactive substances, but it is uncertain whether psychedelics or other drugs were part of the ecology or culture of pre-human ancestors. Moreover, (nonhuman) great apes in captivity are currently being retired from medical research, rendering comparative approaches thus far impracticable. Here, we circumvent this limitation by harnessing the breadth of publicly available YouTube data to show that apes engage in rope spinning during solitary play. When spinning, the apes achieved speeds sufficient to alter self-perception and situational awareness that were comparable to those tapped for transcendent experiences in humans (e.g. Sufi whirling), and the number of revolutions spun predicted behavioural evidence for dizziness. Thus, spinning serves as a self-sufficient means of changing body-mind responsiveness in hominids. A proclivity for such experiences is shared between humans and great apes, and provides an entry point for the comparative study of the mechanisms, functions, and adaptive value of altered states of mind in human evolution.

In humans, individuals’ social setting determines which and how language is acquired. Social seclusion experiments show that sociality also guides vocal development in songbirds and marmoset monkeys, but absence of similar great ape data has been interpreted as support to saltational notions for language origin, even if such laboratorial protocols are unethical with great apes. Here we characterize the repertoire entropy of orangutan individuals and show that in the wild, different degrees of sociality across populations are associated with different ‘vocal personalities’ in the form of distinct regimes of alarm call variants. In high-density populations, individuals are vocally more original and acoustically unpredictable but new call variants are short lived, whereas individuals in low-density populations are more conformative and acoustically consistent but also exhibit more complex call repertoires. Findings provide non-invasive evidence that sociality predicts vocal phenotype in a wild great ape. They prove false hypotheses that discredit great apes as having hardwired vocal development programmes and non-plastic vocal behaviour. Social settings mould vocal output in hominids besides humans.

Background Survival benefit from low tidal volume (VT) ventilation (LTVV) has been demonstrated for patients with acute respiratory distress syndrome (ARDS), and patients not having ARDS could also benefit from this strategy. Organizational factors may play a role on adherence to LTVV. The present study aimed to identify organizational factors with an independent association with adherence to LTVV. Methods Secondary analysis of the database of a multicenter two-phase study (prospective cohort followed by a cluster-randomized trial) performed in 118 Brazilian intensive care units. Patients under mechanical ventilation at day 2 were included. LTVV was defined as a VT ≤ 8 ml/kg PBW on the second day of ventilation. Data on the type and number of beds of the hospital, teaching status, nursing, respiratory therapists and physician staffing, use of structured checklist, and presence of protocols were tested. A multivariable mixed-effect model was used to assess the association between organizational factors and adherence to LTVV. Results The study included 5719 patients; 3340 (58%) patients received LTVV. A greater number of hospital beds (absolute difference 7.43% [95% confidence interval 0.61–14.24%]; p = 0.038), use of structured checklist during multidisciplinary rounds (5.10% [0.55–9.81%]; p = 0.030), and presence of at least one nurse per 10 patients during all shifts (17.24% [0.85–33.60%]; p = 0.045) were the only three factors that had an independent association with adherence to LTVV. Conclusions Number of hospital beds, use of a structured checklist during multidisciplinary rounds, and nurse staffing are organizational factors associated with adherence to LTVV. These findings shed light on organizational factors that may improve ventilation in critically ill patients.

The presence of eosinophils in the cerebrospinal fluid (CSF) should always be considered abnormal. This study aimed to evaluate the causes of eosinophils in the CSF of patients who are HIV positive and HIV negative. This is the first study of eosinophils in the CSF of patients who are HIV-positive. This was a retrospective study of CSF reports from 1996 to 2005, patients were selected based on the presence of eosinophils in the CSF. We analyzed 20,008 CSF reports; eosinophils were present in 5%. The median and interquartile range (IQR) of eosinophils was 2% (1%, 4%). Eosinophilic meningitis (CSF eosinophils ≥ 10%) was present in 12% of the samples. The main etiologies were infectious diseases as follows: neurocysticercosis, Cryptococcus sp. meningitis, and acute bacterial meningitis. In HIV-positive cases, all causes were by infectious disease, the main pathogen being Cryptococcus sp. The probability of neurocysticercosis in a patient from an endemic region who is HIV-negative and has CSF eosinophils more than 10% was five times higher compared to a person without eosinophilic meningitis. There was a weak positive correlation between CSF eosinophils and increased serum eosinophils. Among the HIV-negative cases, the most frequent non-infectious causes were cerebrovascular syndromes, of these hemorrhage (91.5%). In the HIV-positive group, there were no cases of non-infectious cerebral disease. CSF eosinophils are suggestive of disease. The causes must be investigated, considering the most prevalent infectious diseases in the region.

Call control allows an organism to produce an acoustic signal irrespective of its own underlying emotional state. It is thus a prerequisite to “higher” abilities, such as call imitation, innovation and the use of arbitrary or deceptive calls, and therefore to speech. However, among primates, call control is presumed to be greatly confined to humans (Seyfarth and Cheney 2008). Consequently, there is little agreement about its evolutionary precursors (Christiansen and Kirby 2003). Essentially two major models and lines of evidence have been proposed; speech evolved (1) as an extension of acoustic communication in non-human primates (e.g. Seyfarth et al.1980; Slocombe and Zuberbuhler 2005; Arnold and Zuberbuhler 2006; Wich et al.2009) or (2) from non-human primate gestural communication (e.g. Rizzolatti and Arbib 1998; Corballis 2003; Arbib Michael et al. 2008). These models have been seen as mutually exclusive or as sequential accounts in which calls replace gestures (Brown et al. 1999), however, both face limitations concerning the emergence of call control in our evolutionary lineage. Did call control derive from an essentially emotional call use, or from an essentially voluntary gesture use, as that of non-human primates? The acoustic model needs to explain how a fundamentally close-ended acoustic system became open-ended (i.e. with limitless number of elements; alike speech). The gestural model needs to clarify the behaviors and respective functional advantages that allowed a shift (or “translation”) from an open-ended gestural system to an open-ended acoustic system.

The trans-Sialidase from Trypanosoma cruzi (TcTS) might be a key enzyme in search of new and more effective anti-Trypanosoma cruzi agents. In this report, molecular docking and quantum mechanical/molecular mechanical (QM/MM) molecular dynamics (MD) simulations were employed to determine the binding mode of the three TcTS inhibitors, two quinolinones derivatives (DHQ and THQ) and DANA. The results show that the sulfone group from THQ plays an important role in the protein-inhibitor interactions. In addition, a detailed analysis of the interactions of these inhibitors with key residues inside the binding pocket of TcTS has been carried out using AM1/MM. The residues Asp59, Asp247, Arg35, Arg245, and Arg314 are appointed as key residues to affinity energy of the complexes studied. Finally, the B3LYP/MM and AM1/MM methods were used to calculate global interaction energy, in order to understand the potential of these inhibitors. Among the inhibitors studied, THQ is confirmed as the most efficient one for inhibiting TcTS.

Corynebacterium pseudotuberculosis is a facultatively intracellular Gram-positive bacterium that causes caseous lymphadenitis, principally in sheep and goats, though sometimes in other species of animals, leading to considerable economic losses. This pathogen has a TCS known as PhoPR, which consists of a sensory histidine kinase protein (PhoR) and an intracellular response regulator protein (PhoP). This system is involved in the regulation of proteins present in various processes, including virulence. The regulation is activated by PhoP protein phosphorylation, an event that requires a magnesium (Mg(2+)) ion. Here we describe the 3D structure of the regulatory response protein (PhoP) of C. pseudotuberculosis through molecular modeling by homology. The model generated provides the first structural information on a full-length member of the OmpR/PhoP subfamily. Classical molecular dynamics was used to investigate the stability of the model. In addition, we used quantum mechanical/molecular mechanical techniques to perform (internal, potential) energy optimizations to determine the interaction energy between the Mg(2+) ion and the structure of the PhoP protein. Analysis of the interaction energy residue by residue shows that Asp-16 and Asp-59 play an important role in the protein-Mg(2+) ion interactions. These results may be useful for the future development of a new vaccine against tuberculosis based on genetic attenuation via a point mutation that results in the polar residue Asp-16 and/or Asp-59 being replaced with a nonpolar residue in the DNA-binding domain of PhoP of C. pseudotuberculosis.

The capacity of nonhuman primates to actively modify the acoustic structure of existing sounds or vocalizations in their repertoire appears limited. Several studies have reported population or community differences in the acoustical structure of nonhuman primate long distance calls and have suggested vocal learning as a mechanism for explaining such variation. In addition, recent studies on great apes have indicated that there are repertoire differences between populations. Some populations have sounds in their repertoire that others have not. These differences have also been suggested to be the result of vocal learning. On yet another level great apes can, after extensive human training, also learn some species atypical vocalizations. Here we show a new aspect of great ape vocal learning by providing data that an orangutan has spontaneously (without any training) acquired a human whistle and can modulate the duration and number of whistles to copy a human model. This might indicate that the learning capacities of great apes in the auditory domain might be more flexible than hitherto assumed.

Researchers have documented individual vocal recognition in several primate species but do not know whether the changes in acoustical parameters that might occur over distance influence the informational content of a call that relates to individuality. Accordingly, we performed playback experiments using male orangutan long-distance calls (long calls) and rerecorded them at increasing distances from the source. We aimed to determine 1) which acoustical parameters changed over distance and 2) whether the percentage of calls that a discriminant analyses would assign to the correct individual would change over distance. High-frequency harmonics were attenuated and lost with increasing distance, but other parameters did not change. The percentage of calls assigned to the correct individual did not change over distance, indicating that even though there are some acoustical changes over distance the opportunity for other individuals to recognize the caller remains similar until ≤300 m, which was the maximum distance at which we rerecorded calls. Extending similar experiments to other primate species and other taxa, while subsequently conducting experiments to assess whether individual discrimination by receivers is indeed based on relatively stable acoustical parameters, would forward our understanding of acoustic communication.