The influence of doping on flash sintering condition in SrTi1–xFexO3–δ

The innovative flash sintering process raised a great interest in the past few years due to its applicability in various engineering fields and the interesting scientific questions it evokes. This technique could be beneficial in many applications since it reduces the time and cost of the sintering process. Joule heating can explain the sudden temperature rise of the sample, which enhances the rate of grain boundary diffusion. However, for a given material the temperature of the sample remains lower than the temperature at conventional sintering. Although Joule heating is a significant phenomenon, it is proposed that lattice defects and their transport properties are also influenced by the applied field and can play an important role in the flash sintering process. In this work, iron doped SrTiO3, was chosen as a model material to examine the influence of dopants on the threshold conditions of flash sintering (i.e., temperature and applied electric field). SrTiO3 has been flash-sintered before at different furnace temperatures and electric fields. [1,2] Additionally, it is a simple cubic perovskite and its defect chemistry is well defined in the dilute dopant case. The threshold conditions of five different SrTi1-xFexO3-δ samples (x=0, 0.1, 0.5, 1, 3) indicate that the furnace temperature decreases when doping is increased. This result can be explained both by the increase of the electric conductivity that affects directly the Joule heating; and by the existence of added ionic defects in the lattice. In a doped semiconductor, extrinsic defects can be compensated electronically and by self-compensation (native ionic defects). The analysis of point defect concentration was done using the doping factor concept. The doping factor, f, is defined by the ratio between the electron concentration after introducing a dopant and the electron concentration at a reference state. Substituting the new electron concentration in the mass action relations of all the defects yields new values for their concentrations in the doped material, expressed by the same factor f. [3] The flash sintering setup is assembled in a dilatometer, utilizing its ability to measure shrinkage in-situ. [4] AC measurements are performed before applying the field and after the sintering has been terminated. DC Electrical field is applied to the electrodes at both edges of the sample via source meters to achieve maximum voltage of 600 V with limited current of 100 mA

The effect of environmental conditions on the physiological response during a stand-up paddle surfing session

Stand Up Paddleboard (SUP) surfing entails riding breaking waves and maneuvering the board on the wave face in a similar manner to traditional surfing. Despite some scientific investigations on SUP, little is known about SUP surfing. The aim of this study was to investigate the physiological response during SUP surfing sessions and to determine how various environmental conditions can influence this response. Heart rate (HR) of an experienced male SUP surfer aged 43 was recorded for 14.9 h during ten surfing sessions and synced with on board video footage to enable the examination of the effect of different surfing modes and weather conditions on exercise intensity. Results indicated that the SUP surfer’s HR was above 70% of HRmax during 85% of each session, with the greatest heart rates found during falls off the board (~85% HRmax) and while paddling back to the peak (~83% HRmax). Total time surfing a wave was less than 5%, with the majority of time spent paddling back into position. Wind speed positively correlated with HR (r = 0.75, p < 0.05) and wave height negatively correlated with wave caching frequency (r = 0.73, p < 0.05). The results highlight the aerobic fitness for SUP surfing, where wave riding, paddling back to the peak, and falls appear to be associated with the greatest cardiovascular demand and demonstrate that environmental conditions can have an effect on the physiological response during SUP surfing sessions

Updated View on the Relation of the Pineal Gland to Autism Spectrum Disorders

Identification of the biological features of autism is essential for designing an efficient treatment and for prevention of the disorder. Though the subject of extensive research, the neurophysiological features of autism remain unclear. One of the proposed biological causes of autism is malfunction of the pineal gland and deficiency of its principal hormone, melatonin. The main function of melatonin is to link and synchronize the body's homeostasis processes to the circadian and seasonal rhythms, and to regulate the sleep-wake cycle. Therefore, pineal dysfunction has been implicated based on the common observation of low melatonin levels and sleep disorders associated with autism. In this perspective, we highlight several recent findings that support the hypothesis of pineal gland/melatonin involvement in autism. Another common symptom of autism is abnormal neuroplasticity, such as cortical overgrowth and dendritic spine dysgenesis. Here, we synthesize recent information and speculate on the possibility that this abnormal neuroplasticity is caused by hyperactivity of endogenous N,N-dimethyltryptamine (DMT). The pineal gland was proposed as the source of DMT in the brain and therefore, our assumption is that besides melatonin deficiency, pineal dysfunction might also play a part in the development of autism through abnormal metabolism of DMT. We hope that this manuscript will encourage future research of the DMT hypothesis and reexamination of several observations that were previously attributed to other factors, to see if they could be related to pineal gland/melatonin malfunction. Such research could contribute to the development of autism treatment by exogenous melatonin and monitored light exposure

Assessment of Various Anesthetic Agents on Octopus vulgaris Paralarvae

European Directive 2010/63 addresses the welfare of cephalopod species used in scientific projects under European jurisdiction and covers experimental procedures likely to cause pain, suffering, distress, or lasting harm. These procedures require authorization from the National Competent Authorities. In aquaculture research, some procedures require the temporary immobilization of individuals to allow for measuring body parameters (i.e., weight, sex, gonad condition, and others), avoiding any damage. This study compares three anesthetics used on common octopus, Octopus vulgaris, paralarvae to reach a state of sedation. The anesthetics were tested for their effects at different concentrations: magnesium chloride (6.8, 13.6, 20.4, and 27.4 g/L), ethanol (8, 10, and 12 mL/L), and clove oil (0.2, 0.3, and 0.4 g/L). Three variables were monitored: induction, recovery, and stressful behavior of paralarvae during treatments. Significant differences were found between anesthetics, both in the induction and recovery time, and between concentrations of the same anesthetic. The shortest times of induction and recovery corresponded to ethanol at low concentrations, 10 mL/L (20±1 sec) and 8 mL/L (19±2 sec), respectively. Clove oil at 0.2 g/L was the slowest to reach sedation (340±7 sec). Magnesium chloride at 20.4 g/L showed longer recovery times (554±201 sec) with increasing concentrations. Octopus paralarvae showed adverse behavior only under clove oil treatments, whose use is therefore considered inadmissible. This study shows that ethanol at 10 mL/L may be suitable as a reliable anesthetic for octopus paralarvae, diminishing the induction and recovery time without showing any stressful behavior.En prensa0,83

Policy Brief: UNSCR 1325: The Challenges of Framing Women’s Rights as a Security Matter

While UN Security Council Resolution (UNSCR) 1325 has certainly increased awareness among international actors about women’s and gender issues in armed conflict, opened new spaces for dialogue and partnerships from global to local levels, and even created opportunities for new resources for women’s rights, successes remain limited and notably inconsistent. To understand some of these shortcomings and think creatively about how to move the women, peace and security agenda forward, it is essential to understand the conceptual assumptions underscoring UNSCR 1325

The Current State of Cephalopod Science and Perspectives on the Most Critical Challenges Ahead From Three Early-Career Researchers

International audienceHere, three researchers who have recently embarked on careers in cephalopod biology discuss the current state of the field and offer their hopes for the future. Seven major topics are explored genetics, aquaculture, climate change, welfare, behavior, cognition, and neurobiology. Recent developments in each of these fields are reviewed and the potential of emerging technologies to address specific gaps in knowledge about cephalopods are discussed. Throughout, the authors highlight specific challenges that merit particular focus in the near-term. This review and prospectus is also intended to suggest some concrete near-term goals to cephalopod researchers and inspire those working outside the field to consider the revelatory potential of these remarkable creatures

Transcriptome Analysis of the Octopus vulgaris Central Nervous System

Background: Cephalopoda are a class of Mollusca species found in all the world's oceans. They are an important model organism in neurobiology. Unfortunately, the lack of neuronal molecular sequences, such as ESTs, transcriptomic or genomic information, has limited the development of molecular neurobiology research in this unique model organism. Results: With high-throughput Illumina Solexa sequencing technology, we have generated 59,859 high quality sequences from 12,918,391 paired-end reads. Using BLASTx/BLASTn, 12,227 contigs have blast hits in the Swissprot, NR protein database and NT nucleotide database with E-value cutoff 1e(-5). The comparison between the Octopus vulgaris central nervous system (CNS) library and the Aplysia californica/Lymnaea stagnalis CNS ESTs library yielded 5.93%/13.45% of O. vulgaris sequences with significant matches (1e(-5)) using BLASTn/tBLASTx. Meanwhile the hit percentage of the recently published Schistocerca gregaria, Tilapia or Hirudo medicinalis CNS library to the O. vulgaris CNS library is 21.03%-46.19%. We constructed the Phylogenetic tree using two genes related to CNS function, Synaptotagmin-7 and Synaptophysin. Lastly, we demonstrated that O. vulgaris may have a vertebrate-like Blood-Brain Barrier based on bioinformatic analysis. Conclusion: This study provides a mass of molecular information that will contribute to further molecular biology research on O. vulgaris. In our presentation of the first CNS transcriptome analysis of O. vulgaris, we hope to accelerate the study of functional molecular neurobiology and comparative evolutionary biology.National fund for oceanography research in Public Interest [201005013]; National Key Technology RD Program [2011BAD13

Enriched Environment Increases PCNA and PARP1 Levels in Octopus vulgaris Central Nervous System: First Evidence of Adult Neurogenesis in Lophotrochozoa

Organisms showing a complex and centralized nervous system, such as teleosts, amphibians, reptiles, birds and mammals, and among invertebrates, crustaceans and insects, can adjust their behavior according to the environmental challenges. Proliferation, differentiation, migration, and axonal and dendritic development of newborn neurons take place in brain areas where structural plasticity, involved in learning, memory, and sensory stimuli integration, occurs. Octopus vulgaris has a complex and centralized nervous system, located between the eyes, with a hierarchical organization. It is considered the most "intelligent" invertebrate for its advanced cognitive capabilities, as learning and memory, and its sophisticated behaviors. The experimental data obtained by immunohistochemistry and western blot assay using proliferating cell nuclear antigen and poli (ADP-ribose) polymerase 1 as marker of cell proliferation and synaptogenesis, respectively, revealed cell proliferation in areas of brain involved in learning, memory, and sensory stimuli integration. Furthermore, we showed how enriched environmental conditions affect adult neurogenesis

I Know My Neighbour: Individual Recognition in Octopus vulgaris

Background: Little is known about individual recognition (IR) in octopuses, although they have been abundantly studied for their sophisticated behaviour and learning capacities. Indeed, the ability of octopuses to recognise conspecifics is suggested by a number of clues emerging from both laboratory studies (where they appear to form and maintain dominance hierarchies) and field observations (octopuses of neighbouring dens display little agonism between each other). To fill this gap in knowledge, we investigated the behaviour of 24 size-matched pairs of Octopus vulgaris in laboratory conditions. Methodology/Principal Findings: The experimental design was composed of 3 phases: Phase 1 (acclimatization): 12 ‘‘sightallowed’’ (and 12 ‘‘isolated’’) pairs were maintained for 3 days in contiguous tanks separated by a transparent (and opaque) partition to allow (and block) the vision of the conspecific; Phase 2 (cohabitation): members of each pair (both sight-allowed and isolated) were transferred into an experimental tank and were allowed to interact for 15 min every day for 3 consecutive days; Phase 3 (test): each pair (both sight-allowed and isolated) was subject to a switch of an octopus to form pairs composed of either familiar (‘‘sham switches’’) or unfamiliar conspecifics (‘‘real switches’’). Longer latencies (i.e. the time elapsed from the first interaction) and fewer physical contacts in the familiar pairs as opposed to the unfamiliar pairs were used as proxies for recognition. Conclusions: Octopuses appear able to recognise conspecifics and to remember the individual previously met for at leas