Human domination of the global water cycle absent from depictions and perceptions

International audienceHuman water use, climate change and land conversion have created a water crisis for billions of individuals and many ecosystems worldwide. Global water stocks and fluxes are estimated empirically and with computer models, but this information is conveyed to policymakers and researchers through water cycle diagrams. Here we compiled a synthesis of the global water cycle, which we compared with 464 water cycle diagrams from around the world. Although human freshwater appropriation now equals half of global river discharge, only 15% of the water cycle diagrams depicted human interaction with water. Only 2% of the diagrams showed climate change or water pollution—two of the central causes of the global water crisis—which effectively conveys a false sense of water security. A single catchment was depicted in 95% of the diagrams, which precludes the representation of teleconnections such as ocean–land interactions and continental moisture recycling. These inaccuracies correspond with specific dimensions of water mismanagement, which suggest that flaws in water diagrams reflect and reinforce the misunderstanding of global hydrology by policymakers, researchers and the public. Correct depictions of the water cycle will not solve the global water crisis, but reconceiving this symbol is an important step towards equitable water governance, sustainable development and planetary thinking in the Anthropocene

Assessing changes in global fire regimes

PAGES, Past Global Changes, is funded by the Swiss Academy of Sciences and the Chinese Academy of Sciences and supported in kind by the University of Bern, Switzerland. Financial support was provided by the U.S. National Science Foundation award numbers 1916565, EAR-2011439, and EAR-2012123. Additional support was provided by the Utah Department of Natural Resources Watershed Restoration Initiative. SSS was supported by Brigham Young University Graduate Studies. MS was supported by National Science Centre, Poland (grant no. 2018/31/B/ST10/02498 and 2021/41/B/ST10/00060). JCA was supported by the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No 101026211. PF contributed within the framework of the FCT-funded project no. UIDB/04033/2020. SGAF acknowledges support from Trond Mohn Stiftelse (TMS) and University of Bergen for the startup grant ‘TMS2022STG03’. JMP participation in this research was supported by the Forest Research Centre, a research unit funded by Fundação para a Ciência e a Tecnologia I.P. (FCT), Portugal (UIDB/00239/2020). A.-LD acknowledge PAGES, PICS CNRS 06484 project, CNRS-INSU, Région Nouvelle-Aquitaine, University of Bordeaux DRI and INQUA for workshop support.Background The global human footprint has fundamentally altered wildfire regimes, creating serious consequences for human health, biodiversity, and climate. However, it remains difficult to project how long-term interactions among land use, management, and climate change will affect fire behavior, representing a key knowledge gap for sustainable management. We used expert assessment to combine opinions about past and future fire regimes from 99 wildfire researchers. We asked for quantitative and qualitative assessments of the frequency, type, and implications of fire regime change from the beginning of the Holocene through the year 2300. Results Respondents indicated some direct human influence on wildfire since at least ~ 12,000 years BP, though natural climate variability remained the dominant driver of fire regime change until around 5,000 years BP, for most study regions. Responses suggested a ten-fold increase in the frequency of fire regime change during the last 250 years compared with the rest of the Holocene, corresponding first with the intensification and extensification of land use and later with anthropogenic climate change. Looking to the future, fire regimes were predicted to intensify, with increases in frequency, severity, and size in all biomes except grassland ecosystems. Fire regimes showed different climate sensitivities across biomes, but the likelihood of fire regime change increased with higher warming scenarios for all biomes. Biodiversity, carbon storage, and other ecosystem services were predicted to decrease for most biomes under higher emission scenarios. We present recommendations for adaptation and mitigation under emerging fire regimes, while recognizing that management options are constrained under higher emission scenarios. Conclusion The influence of humans on wildfire regimes has increased over the last two centuries. The perspective gained from past fires should be considered in land and fire management strategies, but novel fire behavior is likely given the unprecedented human disruption of plant communities, climate, and other factors. Future fire regimes are likely to degrade key ecosystem services, unless climate change is aggressively mitigated. Expert assessment complements empirical data and modeling, providing a broader perspective of fire science to inform decision making and future research priorities.Peer reviewe

Class-AB Square-Root Domain Filters Based on the Floating

In this paper a new approach for design of class-AB current-mode square-root domain filters based on the electronically simulated translinear loop principle is presented. FG-MOS transistors that operate in strong inverted saturation region are employed for implementation of translinear loop circuit. The filter achieves immunity to body effect, low circuit complexity, large input dynamic range, and also works in low voltage compared to those reported before. With supply voltage 1.2V a dynamic range of 46dB at 1% THD is achieved. Simulation results by HSPICE confirm the validity of the proposed design technique and show high performance of the filter

Evaluating the drinking waters microbial flora of reverse osmosis treatment systems in kashan city during summer and autumn (2015)

According to the various difficulties of Distillation desalination system,currently the membrane technology such as Reverse Osmosis (RO) is more useful. High concentration of dissolve solids in supplying water resources in Kashan caused a bad taste and reduced the consumer�s desire for using such water,and often they used treated water in a way that at the conducting time of this study,20 centers treated the water by RO method in the city. Therefore,this study evaluated the microbial flora of produced drinking water of RO treatment system in Kashan city during summer and autumn 2015. In this study the census method have used and the sampling have done from all the RO water treatment centers of the city. Three input,output and after storage,samples have taken. The evaluation of the temperature,residual chlorine,TDS,the storage time,and RO membrane operation time in samples have done. The HPC test has done on the samples in the laboratory and the positive plates have identified in terms of bacterial spices. The tests have repeated in four months of the year from July to October. The results showed 95 residual chlorine in the input samples and the HPC test for these samples showed no contamination. The sample contamination after treatment and the tank were 8 and 15 respectively. In addition,the most contamination level have related to September,which the samples temperature in this month reach its highest level. The Pearson coefficient results showed that there was a significant relation between the Heterotroph colonies number and the residual chlorine and temperature parameters,which was consistent with Karami et al. in Kermanshah and Dobaradaran et al. in Esfahan studies. In addition,there was a significant relation between the Heterotroph colonies number and storage time and RO membrane operation time. © 2016,International Journal of Pharmacy and Technology. All rights reserved

The effects of ultrasound on BBB integration in ischemic brain injury model

Background: Ultrasound (US) has been used in neuroprotection after cerebral ischemia, however the mechanism of action remains unclearly. We have previously shown the protective effect of ultrasound on infarction volume and brain edema in ischemic brain injured at normothermic condition. Ultrasound may also amplify the effect of fibrinolytic medications in thrombolysis process .We have also shown that hyperthermia can exacerbate cerebral ischemic injury and that the efficacy of tissue plasminogen activator (tPA) is reduced in the presence of hyperthermia. In this study, the effects of US alone or in combination with tPA on brain ischemic injury were evaluated.Methods: Focal ischemic brain injury was induced by emblazing a pre-formed clot into the middle cerebral artery in rats. Principally, we examined whether US can reduce the perfusion deficits and, the damage of blood- brain barrier (BBB) in the ischemic injured brain. There are two series of experiments at this study .in the first series, animals were randomly assigned to four groups (n=7 per group) as follows: 1-control (saline), 2-US (1W/cm2, 10 duty cycle ), 3- US+high- tPA (1W/cm2, 10 duty cycle +20 mg/kg) and 4- high -tPA (20 mg/kg). We also examined the effects of US and tPA on BBB integrity after ischemic injury. The animals were assigned into four groups (n=7 per group), treatment is the same as above. BBB permeability was assessed by the Evans blue (EB) extravasations method at 8 h after MCA occlusion. BBB permeability was evaluated by fluorescent detection of extravagated Evans blue dye and Perfusion deficits were analyzed using an Evans blue staining procedure. The perfused microvessels in the brain were visualized using fluorescent microscopy. Areas of perfusion deficits in the brain were traced, calculated and expressed in mm2.Results: The results showed that US improved neurological deficits significantly (p<0.05). The administration of US significantly decreased perfusion deficits and BBB permeability. In the control set, for the US+high tPA, high tPA only and US only groups, the mean perfusion deficits (±SD) were 14.32±3.15, 7.03±4.08, 5.92±1.90 and 9.14±3.37 mm2, respectively, 8 h after MCA occlusion (P<0.05).Conclusions: These studies suggest that US is protective in a rat embolic model of stroke due to decreased perfusion deficits

Effects of neurosurgery on hemodynamic parameters

Background: General anesthesia could be accompanied by changes in hemodynamic parameters (arterial blood pressure, heart rate, rhythm, central venous pressure, and venous blood pressure) that would result in altered intracranial pressure. In deep anesthesia the brain perfusion is dependent on blood pressure. The present study was conducted to determine the effects of neurosurgery on hemodynamic parameters in Naghavi Hospital in Kashan. Materials and methods: This quasi-experimental study was performed on 112 patients. Systolic and diastolic blood pressure, and cardiac rhythm and rate were measured. Then the influence of sex, age, type of operation, duration of surgery and patient’s position on aforementioned parameters were evaluated. Results: The study population included 70 males and 42 females, most of whom aged ≥ 40 years. Hemodynamic changes were more apparent among males. Meanwhile, age of ≥ 40 years, spinal surgery, prone position, and operations of more than 2-hour duration were associated with greater hemodynamic changes. Changes in systolic and diastolic blood pressure during induction was significantly differed regarding the duration of operation and patient’s position. Conclusion: Hemodynamic changes are common in neurosurgical operations. These are different according to the type and duration of surgery and patient’s position. Further studies are highly recommended