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elevated carbon dioxide

Bong Nam Chung, Sang Wook Koh, Kyung San Choi, Jae Ho Joa, Chun Hwan Kim, Gopal Selvakumar
We determined the effects of atmospheric temperature (10-30 ± 2°C in 5°C increments) and carbon dioxide (CO2) levels (400 ± 50 ppm, 540 ± 50 ppm, and 940 ± 50 ppm) on the infection of Solanum tuberosum cv. Chubaek by Potato leafroll virus (PLRV). Below CO2 levels of 400 ± 50 ppm, the PLRV infection rate and RNA content in plant tissues increased as the temperature increased to 20 ± 2°C, but declined at higher temperatures. At high CO2 levels (940 ± 50 ppm), more plants were infected by PLRV at 30 ± 2°C than at 20 or 25 ± 2°C, whereas PLRV RNA content was unchanged in the 20-30 ± 2°C temperature range...
October 2017: Plant Pathology Journal
Christy M Dykstra, Spyros G Pavlostathis
Methanogenic bioelectrochemical systems (BESs), which convert carbon dioxide (CO2) directly to methane (CH4), promise to be an innovative technology for anaerobic digester biogas upgrading. Zero-valent iron (ZVI), which has previously been used to improve CH4 production in anaerobic digesters, has not been explored in methanogenic biocathodes. Thus, the objective of this study was to assess the effect of biocathode ZVI on BES performance at 1 and 2 g/L initial ZVI concentrations and at various cathode potentials (-0...
October 10, 2017: Environmental Science & Technology
Samad Ghaffari, Reza Hajizadeh, Leili Pourafkari, Behrouz Shokouhi, Arezou Tajlil, Sarvin Mazani, Hadiseh Kavandi, Hosein Ansari, Nader D Nader
We investigated the association between the levels of air pollutants and the number of daily admissions due to ST segment elevation myocardial infarction (STEMI) in a metropolitan in the northwest of Iran. Daily concentrations of common air pollutants were obtained for the greater city of Tabriz for a period of 2 years. These reports included sulfur dioxide (SO2), nitrogen dioxide (NO2), nitric oxide (NO), nitrogen byproducts (NOx), carbon monoxide (CO), ozone (O3), and particulate matters < 10 μm (PM10)...
October 4, 2017: Environmental Science and Pollution Research International
Peter C Raynor, Shannon Engelman, Darby Murphy, Gurumurthy Ramachandran, Jeffrey B Bender, Bruce H Alexander
OBJECTIVE: Evolving production practices in the swine industry may alter the working environment. This research characterized the influence of stall versus pen gestation housing and wet versus dry feed in finishing on air contaminant concentrations. METHODS: Eight-hour time-weighted ammonia, hydrogen sulfide, respirable dust, respirable endotoxin, and carbon dioxide concentrations and temperature were measured regularly at stationary locations throughout a year in a facility with parallel gestation stall and open pen housing and parallel finishing rooms using dry and wet feed delivery systems...
October 4, 2017: Journal of Agromedicine
Jingjin Yu, Ran Li, Ningli Fan, Zhimin Yang, Bingru Huang
Global climate changes involve elevated temperature and CO2 concentration, imposing significant impact on plant growth of various plant species. Elevated temperature exacerbates heat damages, but elevated CO2 has positive effects on promoting plant growth and heat tolerance. The objective of this study was to identify metabolic pathways affected by elevated CO2 conferring the improvement of heat tolerance in a C4 perennial grass species, bermudagrass (Cynodon dactylon Pers.). Plants were planted under either ambient CO2 concentration (400 μmol⋅mol(-1)) or elevated CO2 concentration (800 μmol⋅mol(-1)) and subjected to ambient temperature (30/25°C, day/night) or heat stress (45/40°C, day/night)...
2017: Frontiers in Plant Science
T E F Abbott, G Minto, A M Lee, R M Pearse, G L Ackland
Background: Elevated preoperative heart rate (HR) is associated with perioperative myocardial injury and death. In apparently healthy individuals, high resting HR is associated with development of cardiac failure. Given that patients with overt cardiac failure have poor perioperative outcomes, we hypothesized that subclinical cardiac failure, identified by cardiopulmonary exercise testing, was associated with elevated preoperative HR > 87 beats min -1 (HR > 87). Methods: This was a secondary analysis of an observational cohort study of surgical patients aged ≥45 yr...
July 1, 2017: British Journal of Anaesthesia
Chih-Cheng Chen, Chun-Yuh Yang
This study determined the association between fine particles (PM2.5) levels and hospital admissions for chest pain (CP) in Taipei, Taiwan. Hospital admissions for CP and ambient air pollution data for Taipei were obtained for the period 2009-2013. The relative risk of hospital admissions was estimated using a case-crossover approach, after controlling for weather variables, day of the week, seasonality, and long-term time trends. For single-pollutant models (without adjustment for other pollutants), increased frequency of CP admissions was significantly associated with PM2...
September 28, 2017: Journal of Toxicology and Environmental Health. Part A
Agnieszka Wanag, Paulina Rokicka, Ewelina Kusiak-Nejman, Joanna Kapica-Kozar, Rafał J Wrobel, Agata Markowska-Szczupak, Antoni W Morawski
In this paper, the antibacterial activity of titanium dioxide modified with reduced graphene oxide (rGO) was presented. TiO2/rGO photocatalysts were prepared by the hydrothermal method under elevated pressure at 180°C and heated at 100°C in Ar flow. The obtained photocatalysts were characterized by means of XRD, FTIR/DRS, UV-vis/DR, Raman spectroscopy and scanning electron microscopy (SEM). The carbon content was also examined. FTIR/DRS and Raman analysis confirmed the presence of rGO in the TiO2 structure, suggesting a successful modification...
September 22, 2017: Ecotoxicology and Environmental Safety
Gordon T Ober, Carol S Thornber
Coastal ecosystems are subjected to global and local environmental stressors, including increased atmospheric carbon dioxide (CO2) (and subsequent ocean acidification) and nutrient loading. Here, we tested how two common macroalgal species in the Northwest Atlantic (Ulva spp. and Fucus vesiculosus Linneaus) respond to the combination of increased CO2 and nutrient loading. We utilized two levels of pCO2 with two levels of nutrients in a full factorial design, testing the growth rates and tissue quality of Ulva and Fucus grown for 21 days in monoculture and biculture...
September 12, 2017: Marine Environmental Research
Michael M Tymko, Thijs P Kerstens, Kevin W Wildfong, Philip N Ainslie
In addition to increasing sympathetic nervous activity, blood pressure, and cerebral blood flow (CBF), the cold pressor test (CPT) stimulates pain receptors, which may increase ventilation above metabolic demand; this response likely reduces the partial pressure of end-tidal carbon dioxide (PET CO2 ), and will attenuate elevations in CBF. We hypothesized: (1) CPT would elicit hyperventilation, effectively lowering PET CO2 ; (2) the CBF response will be elevated during an isocapnic (controlled PET CO2 ), compared to a poikilocapnic CPT (uncontrolled PET CO2 ); (3) In response to CPT, the common carotid artery (CCA) will vasodilatate, while the internal carotid artery (ICA) will remain unchanged to help regulate CBF...
September 19, 2017: Experimental Physiology
Alaina G C Macdonald, Stéphanie L Bourgon, Rupert Palme, Stephen P Miller, Yuri R Montanholi
Liver abscesses constitute a prominent concern regarding animal health and profitability of the beef industry. Our objective was to evaluate potential biliary and blood indicators of liver abscesses. Twenty-nine beef bulls (initially averaging 356±70.5 kg and 253±30 days of age) were fed a high-concentrate diet during a performance test of 112 days, during which blood was collected at nine time points spaced 0.5-13 days apart within 56 days before slaughter. At the abattoir, blood and bile were collected and livers were inspected for liver abscesses...
2017: Veterinary Record Open
Ashleigh R Currie, Karen Tait, Helen Parry, Beatriz de Francisco-Mora, Natalie Hicks, A Mark Osborn, Steve Widdicombe, Henrik Stahl
Marine ecosystems are exposed to a range of human-induced climate stressors, in particular changing carbonate chemistry and elevated sea surface temperatures as a consequence of climate change. More research effort is needed to reduce uncertainties about the effects of global-scale warming and acidification for benthic microbial communities, which drive sedimentary biogeochemical cycles. In this research, mesocosm experiments were set up using muddy and sandy coastal sediments to investigate the independent and interactive effects of elevated carbon dioxide concentrations (750 ppm CO2) and elevated temperature (ambient +4°C) on the abundance of taxonomic and functional microbial genes...
2017: Frontiers in Microbiology
Om Lata Bhagat, Chhaya Kharya, Ashok Jaryal, Kishore Kumar Deepak
BACKGROUND & OBJECTIVES: Breathing exercises are believed to modulate the cardiovascular oscillations in the body. To assess the validity of the assumption and understand the underlying mechanism, the key autonomic regulatory parameters such as heart rate variability (HRV), blood pressure variability (BPV) and baroreflex sensitivity (BRS) were recorded during controlled slow yogic breathing. Alternate nostril breathing (ANB) was selected as the yogic manoeuvre. METHODS: Twelve healthy volunteers (age 30±3...
April 2017: Indian Journal of Medical Research
Piotr Trębicki, Beatriz Dáder, Simone Vassiliadis, Alberto Fereres
Carbon dioxide (CO2 ) is the main anthropogenic gas which has drastically increased since the industrial revolution, and current concentrations are projected to double by the end of this century. As a consequence, elevated CO2 is expected to alter the earths' climate, increase global temperatures and change weather patterns. This is likely to have both direct and indirect impacts on plants, insect pests, plant pathogens and their distribution, and is therefore problematic for the security of future food production...
August 26, 2017: Insect Science
Daniel M Amos, Mary-Ellen Donnelly, Pattanasak Teeratchanan, Craig L Bull, Andrzej Falenty, Werner F Kuhs, Andreas Hermann, John S Loveday
We present full in situ structural solutions of carbon dioxide hydrate-II and hydrogen hydrate C0 at elevated pressures using neutron and X-ray diffraction. We find both hydrates adopt a common water network structure. The structure exhibits several features not previously found in hydrates; most notably it is chiral and has large open spiral channels along which the guest molecules are free to move. It has a network that is unrelated to any experimentally known ice, silica, or zeolite network but is instead related to two Zintl compounds...
August 30, 2017: Journal of Physical Chemistry Letters
C-Elisa Schaum, Samuel Barton, Elvire Bestion, Angus Buckling, Bernardo Garcia-Carreras, Paula Lopez, Chris Lowe, Samraat Pawar, Nicholas Smirnoff, Mark Trimmer, Gabriel Yvon-Durocher
Phytoplankton photosynthesis is a critical flux in the carbon cycle, accounting for approximately 40% of the carbon dioxide fixed globally on an annual basis and fuelling the productivity of aquatic food webs. However, rapid evolutionary responses of phytoplankton to warming remain largely unexplored, particularly outside the laboratory, where multiple selection pressures can modify adaptation to environmental change. Here, we use a decade-long experiment in outdoor mesocosms to investigate mechanisms of adaptation to warming (+4 °C above ambient temperature) in the green alga Chlamydomonas reinhardtii, in naturally assembled communities...
March 20, 2017: Nature ecology & evolution
Xin Li, Lan Zhang, Golam Jalal Ahammed, Zhi-Xin Li, Ji-Peng Wei, Chen Shen, Peng Yan, Li-Ping Zhang, Wen-Yan Han
Rising CO2 concentration, a driving force of climate change, is impacting global food security by affecting plant physiology. Nevertheless, the effects of elevated CO2 on primary and secondary metabolism in tea plants (Camellia sinensis L.) still remain largely unknown. Here we showed that exposure of tea plants to elevated CO2 (800 µmol mol(-1) for 24 d) remarkably improved both photosynthesis and respiration in tea leaves. Furthermore, elevated CO2 increased the concentrations of soluble sugar, starch and total carbon, but decreased the total nitrogen concentration, resulting in an increased carbon to nitrogen ratio in tea leaves...
August 11, 2017: Scientific Reports
K K McLauchlan, L M Gerhart, J J Battles, J M Craine, A J Elmore, P E Higuera, M C Mack, B E McNeil, D M Nelson, N Pederson, S S Perakis
Forests cover 30% of the terrestrial Earth surface and are a major component of the global carbon (C) cycle. Humans have doubled the amount of global reactive nitrogen (N), increasing deposition of N onto forests worldwide. However, other global changes-especially climate change and elevated atmospheric carbon dioxide concentrations-are increasing demand for N, the element limiting primary productivity in temperate forests, which could be reducing N availability. To determine the long-term, integrated effects of global changes on forest N cycling, we measured stable N isotopes in wood, a proxy for N supply relative to demand, on large spatial and temporal scales across the continental U...
August 10, 2017: Scientific Reports
Sisi Geng, Bing Yu, Ning Zhu, Craig Dufresne, Sixue Chen
Stomatal guard cell response to various stimuli is an important process that balances plant carbon dioxide (CO2) uptake and water transpiration. Elevated CO2 induces stomatal closure, while low CO2 promotes stomatal opening. The signaling process of elevated CO2 induced stomatal closure has been extensively studied in recent years. However, the mechanism of low CO2 induced stomatal opening is not fully understood. Here we report metabolomic and proteomic responses of Brassica napus guard cells to low CO2 using hyphenated mass spectrometry technologies...
2017: Frontiers in Molecular Biosciences
Laura E Morris, Daniela Flück, Philip N Ainslie, Ali M McManus
Physiological responses to hypoxia in children are incompletely understood. We aimed to characterize cerebrovascular and ventilatory responses to normobaric hypoxia in girls and women. Ten healthy girls (9.9 ± 1.7 years; mean ± SD; Tanner stage 1 and 2) and their mothers (43.9 ± 3.5 years) participated. Internal carotid (ICA) and vertebral artery (VA) velocity, diameter and flow (Duplex ultrasound) was recorded pre- and post-1 h of hypoxic exposure (FIO2 = 0.126;~4000 m) in a normobaric chamber...
August 2017: Physiological Reports
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