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Extreme physiology

Daryl C Yang, Jennifer R Deuis, Daniel Dashevsky, James Dobson, Timothy N W Jackson, Andreas Brust, Bing Xie, Ivan Koludarov, Jordan Debono, Iwan Hendrikx, Wayne C Hodgson, Peter Josh, Amanda Nouwens, Gregory J Baillie, Timothy J C Bruxner, Paul F Alewood, Kelvin Kok Peng Lim, Nathaniel Frank, Irina Vetter, Bryan G Fry
Millions of years of evolution have fine-tuned the ability of venom peptides to rapidly incapacitate both prey and potential predators. Toxicofera reptiles are characterized by serous-secreting mandibular or maxillary glands with heightened levels of protein expression. These glands are the core anatomical components of the toxicoferan venom system, which exists in myriad points along an evolutionary continuum. Neofunctionalisation of toxins is facilitated by positive selection at functional hotspots on the ancestral protein and venom proteins have undergone dynamic diversification in helodermatid and varanid lizards as well as advanced snakes...
October 18, 2016: Toxins
Wei-Lin Wang, David Shechter
Chromatin, primarily a complex of DNA and histone proteins, is the physiological form of the genome. Chromatin is generally repressive for transcription and other information transactions that occur on DNA. A wealth of post-translational modifications on canonical histones and histone variants encode regulatory information to recruit or repel effector proteins on chromatin, promoting and further repressing transcription and thereby form the basis of epigenetic information. During metazoan oogenesis, large quantities of histone proteins are synthesized and stored in preparation for the rapid early cell cycles of development and to elicit maternal control of chromatin assembly pathways...
2016: International Journal of Developmental Biology
Michael A Mole, Shaun Rodrigues DÁraujo, Rudi J van Aarde, Duncan Mitchell, Andrea Fuller
Most of southern Africa's elephants inhabit environments where environmental temperatures exceed body temperature, but we do not know how elephants respond to such environments. We evaluated the relationships between apparent thermoregulatory behaviour and environmental, skin and core temperatures for tame savanna elephants (Loxodonta africana) that were free-ranging in the hot parts of the day, in their natural environment. Environmental temperature dictated elephant behaviour within a day, with potential consequences for fine-scale habitat selection, space use and foraging...
2016: Conservation Physiology
Valérie Bernard, Sakina Kherra, Bruno Francou, Jérôme Fagart, Say Viengchareun, Jérôme Guéchot, Asmahane Ladjouze, Anne Guiochon-Mantel, Kenneth S Korach, Nadine Binart, Marc Lombès, Sophie Christin-Maitre
CONTEXT: Estrogens influence many physiological processes in mammals, including reproduction. Estrogen peripheral actions are mainly mediated through estrogen receptors (ER) α and β, encoded by ESR1 and ESR2 genes, respectively. OBJECTIVE: To describe a family in which three members presented with estrogen insensitivity. DESIGN AND SETTING: Clinical evaluation, genetic and mutational analysis were performed in an academic medical center...
October 18, 2016: Journal of Clinical Endocrinology and Metabolism
Hye Yeon Koh, Hyun Park, Jun Hyuck Lee, Se Jong Han, Young Chang Sohn, Sung Gu Lee
Psychrobacter sp. PAMC 21119, isolated from Antarctic permafrost soil, grows and proliferates at subzero temperatures. However, its major mechanism of cold adaptation regulation remains poorly understood. We investigated the transcriptomic and proteomic responses of this species to cold temperatures by comparing profiles at -5°C and 20°C to understand how extreme microorganisms survive under subzero conditions. We found a total of 2,906 transcripts and 584 differentially expressed genes (≥ 2 fold, p <0...
October 17, 2016: Environmental Microbiology
Hari Bhupathi Krishnan, Alaa Alaswad, Nathan Wayne Oehrle, Jason Gillman
Legumes form symbiotic association with soil-dwelling bacteria collectively called rhizobia. This association results in the formation of nodules, unique plant-derived organs, within which the rhizobia are housed. Rhizobia encoded-nitrogenase facilitates the conversation of atmospheric nitrogen into ammonia, which is utilized by the plants for its growth and development. Fatty acids have been shown to play an important role in root nodule symbiosis. In this study, we have investigated the role of Stearoyl-Acyl Carrier Protein Desaturase- isoform C (SACPD-C), a soybean enzyme that catalyzes the conversion of stearic acid into oleic acid, which is expressed in developing seeds and in nitrogen fixing nodules...
October 17, 2016: Molecular Plant-microbe Interactions: MPMI
Christoph Zinner, David Morales-Alamo, Niels Ørtenblad, Filip J Larsen, Tomas A Schiffer, Sarah J Willis, Miriam Gelabert-Rebato, Mario Perez-Valera, Robert Boushel, Jose A L Calbet, Hans-Christer Holmberg
To elucidate the mechanisms underlying the differences in adaptation of arm and leg muscles to sprint training, over a period of 11 days 16 untrained men performed six sessions of 4-6 × 30-s all-out sprints (SIT) with the legs and arms, separately, with a 1-h interval of recovery. Limb-specific VO2peak, sprint performance (two 30-s Wingate tests with 4-min recovery), muscle efficiency and time-trial performance (TT, 5-min all-out) were assessed and biopsies from the m. vastus lateralis and m. triceps brachii taken before and after training...
2016: Frontiers in Physiology
A E Hoban, R D Moloney, A V Golubeva, K A McVey Neufeld, O O'Sullivan, E Patterson, C Stanton, T G Dinan, G Clarke, J F Cryan
Gut microbiota colonization is a key event for host physiology that occurs early in life. Disruption of this process leads to altered brain development which ultimately manifests as changes in brain function and behaviour in adulthood. Studies using germ-free mice highlight the extreme impact on brain health that results from life without commensal microbes, however the impact of microbiota disturbances occurring in adulthood is less studied. To this end, we depleted the gut microbiota of 10-week-old male Sprague Dawley rats via chronic antibiotic treatment...
October 11, 2016: Neuroscience
Ricardo Zorron, Alcides Branco, Jose Sampaio, Claudia Bothe, Tido Junghans, Gyurdzhan Rasim, Johann Pratschke, Safak Guel-Klein
BACKGROUND: The anatomical and physiological changes after Roux-en-Y gastric bypass for morbid obesity can lead to severe hyperinsulinemic hypoglycemia with neuroglycopenia in a small percentage of patients. The exact physiologic mechanism is not completely understood. Surgical reversal to the original anatomy and distal or total pancreatectomy are current therapeutic options to reverse the hypoglycemic effect, with substantial associated morbidity. Our group reports a pilot clinical series of a novel surgical technique using one-anastomosis jejunal interposition with gastric remnant resection (Branco-Zorron Switch)...
October 13, 2016: Obesity Surgery
C Belvedere, A Ensini, M d'Amato, P Barbadoro, A Leardini
PURPOSE: Physiological elongation and orientation of patellar tendon fibres are among the scopes of total knee arthroplasty, but little is known in the three dimensions. The study aims to assess in vitro these variations at the intact and replaced knee, with and without patellar resurfacing. It was hypothesised that fibre patterns differ before and after prosthesis implantation, and between specific prosthesis designs. It was also expected that patellar resurfacing would affect relevant results...
October 13, 2016: Knee Surgery, Sports Traumatology, Arthroscopy: Official Journal of the ESSKA
Kathryn R Klement, Ellen M Lee, James K Ambler, Sarah A Hanson, Evelyn Comber, David Wietting, Michael F Wagner, Valerie R Burns, Bert Cutler, Nadine Cutler, Elwood Reid, Brad J Sagarin
Participation in extreme rituals (e.g., fire-walking, body-piercing) has been documented throughout history. Motivations for such physically intense activities include religious devotion, sensation-seeking and social bonding. The present study aims to explore an extreme ritual within the context of bondage/discipline, dominance/submission and sadism/masochism (BDSM): the 'Dance of Souls', a 160-person ritual involving temporary piercings with weights or hooks attached and dancing to music provided by drummers...
October 14, 2016: Culture, Health & Sexuality
Margarida Rocheta, João L Coito, Miguel J N Ramos, Luísa Carvalho, Jörg D Becker, Pablo Carbonell-Bejerano, Sara Amâncio
BACKGROUND: Predicted climate changes announce an increase of extreme environmental conditions including drought and excessive heat and light in classical viticultural regions. Thus, understanding how grapevine responds to these conditions and how different genotypes can adapt, is crucial for informed decisions on accurate viticultural actions. Global transcriptome analyses are useful for this purpose as the response to these abiotic stresses involves the interplay of complex and diverse cascades of physiological, cellular and molecular events...
October 12, 2016: BMC Plant Biology
Joshua R Hancock, Sean P Place
As we move into the Anthropocene, organisms inhabiting marine environments will continue to face growing challenges associated with changes in ocean pH (ocean acidification), dissolved oxygen (dead zones) and temperature. These factors, in combination with naturally variable environments such as the rocky intertidal zone, may create extreme physiological challenges for organisms that are already performing near their biological limits. Although numerous studies have examined the impacts of climate-related stressors on intertidal animals, little is known about the underlying physiological mechanisms driving adaptation to ocean acidification and how this may alter organism interactions, particularly in marine vertebrates...
2016: Conservation Physiology
Farron L McIntee, Patrizia Giannoni, Steven Blais, George Sommer, Thomas A Neubert, Agueda Rostagno, Jorge Ghiso
Amyloid β (Aβ) is the major constituent of the brain deposits found in parenchymal plaques and cerebral blood vessels of patients with Alzheimer's disease (AD). Several lines of investigation support the notion that synaptic pathology, one of the strongest correlates to cognitive impairment, is related to the progressive accumulation of neurotoxic Aβ oligomers. Since the process of oligomerization/fibrillization is concentration-dependent, it is highly reliant on the homeostatic mechanisms that regulate the steady state levels of Aβ influencing the delicate balance between rate of synthesis, dynamics of aggregation, and clearance kinetics...
2016: Frontiers in Aging Neuroscience
Vicente Javier Clemente-Suárez, José Juan Robles-Pérez, Jesús Fernández-Lucas
Parachute jump is an extreme activity that elicits an intense stress response that affects jumpers' body systems being able to put them at risk. The present research analysed modifications in blood oxygen saturation (BOS), heart rate (HR), cortisol, glucose, lactate, creatine kinase (CK), muscles strength, cortical arousal, autonomic modulation, pistol magazine reload time (PMRT) and state anxiety before and after an automatic open parachute jump in 38 male Spanish soldiers (25.6 ± 5.9 years). A MANOVA with samples as a fixed factor and Effect Size (ES) were conducted...
October 11, 2016: Journal of Sports Sciences
Lee McMichael, Daniel Edson, David Mayer, Alice Broos, Steven Kopp, Joanne Meers, Hume Field
Bats of the genus Pteropus (Pteropodidae), colloquially known as flying foxes, are recognized as the natural reservoir of Hendra virus, a zoonotic paramyxovirus responsible for mortality in horses and humans. Some previous studies have suggested that physiologic and ecologic factors promote Hendra virus infection in flying foxes, and by extension, spillover to horses and humans. However, the impact of Hendra virus infection on relevant physiologic biomarkers in flying foxes has not been measured. Over 12 mo in eastern Australia, we captured and sampled 446 individual black flying foxes ( Pteropus alecto ), a putative primary reservoir host species, and measured a suite of hematologic, plasma biochemistry, and urinary biomarkers...
October 10, 2016: Journal of Wildlife Diseases
Pascale Gisquet-Verrier, Daniel Tolédano, Claire Le Dorze
Post-traumatic stress disorder (PTSD) and addiction to drugs of abuse are two common diseases, showing high comorbidity rates. This review presents a number of evidence showing similarities between these two pathologies, especially the hyper-responsiveness to environmental cues inducing a reactivation of the target memory leading either to re-experiencing (PTSD), or drug craving. Accordingly, PTSD and addiction to drug of abuse might by considered as memory pathologies, underlined by the same physiological process...
September 15, 2016: Thérapie
Stéphane Blanc, Yannis Michalakis
The effect of environmental factors on the efficiency of plant virus transmission is extremely difficult to predict, because they obviously impact concomitantly multiple steps of the complex three-way plant-virus-vector interaction. This review summarizes the diversity of the relationship between plants, viruses and insect vectors, and highlights the numerous phases of this process that can be altered by the virus in ways that can potentially enhance its transmission success. Many of the reported cases are often considered to be possible viral manipulations acting through modifications of the physiology of the host plant, indirectly reaching to the insect vector...
August 2016: Current Opinion in Insect Science
Aline Amérand, Hélène Mortelette, Marc Belhomme, Christine Moisan
Silvering, the last metamorphosis in the eel life cycle induces morphological and physiological modifications in yellow eels (sedentary stage). It pre-adapts them to cope with the extreme conditions they will encounter during their 6000-km spawning migration. A previous study showed that silver eels are able to cope with reactive oxygen species (ROS) over-production linked to an increase in aerobic metabolism during sustained swimming, but the question remains as to whether this mechanism is associated with silvering...
October 4, 2016: Respiratory Physiology & Neurobiology
Yuko Fukata, Norihiko Yokoi, Yuri Miyazaki, Masaki Fukata
Physiological functioning of the brain requires fine-tuned synaptic transmission, and its dysfunction causes various brain disorders such as autism, dementia, and epilepsy. It is therefore extremely important to identify and characterize key regulators of synaptic function. In particular, disease-related synaptic proteins, such as autism-related neurexin-neuroligin and psychiatric disorder-related NMDA receptor, have attracted considerable attention. Recent basic and clinical research has highlighted critical roles of a ligand-receptor complex, LGI1-ADAM22, in synaptic transmission and brain function, as mutations in the LGI1 gene cause autosomal dominant lateral temporal lobe epilepsy and autoantibodies to LGI1 cause limbic encephalitis which is characterized by memory loss and seizures...
October 4, 2016: Neuroscience Research
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