139 research outputs found
An integrated model for the assessment of global water resources ? Part 1: Input meteorological forcing and natural hydrological cycle modules
International audienceAn integrated global water resources model was developed consisting of six modules: land surface hydrology, river routing, crop growth, reservoir operation, environmental flow requirement estimation, and anthropogenic water withdrawal. It simulates both natural and anthropogenic water flow globally (excluding Antarctica) on a daily basis at a spatial resolution of 1°×1° (longitude and latitude). The simulation period is 10 years, from 1986 to 1995. This first part of the two-feature report describes the input meteorological forcing and natural hydrological cycle modules of the integrated model, namely the land surface hydrology module and the river routing module. The input meteorological forcing was provided by the second Global Soil Wetness Project (GSWP2), an international land surface modeling project. Several reported shortcomings of the forcing component were improved. The land surface hydrology module was developed based on a bucket type model that simulates energy and water balance on land surfaces. Simulated runoff was compared and validated with observation-based global runoff data sets and observed streamflow records at 32 major river gauging stations around the world. Mean annual runoff agreed well with earlier studies at global, continental, and continental zonal mean scales, indicating the validity of the input meteorological data and land surface hydrology module. In individual basins, the mean bias was less than ±20% in 14 of the 32 river basins and less than ±50% in 24 of the basins. The performance was similar to the best available precedent studies with closure of energy and water. The timing of the peak in streamflow and the shape of monthly hydrographs were well simulated in most of the river basins when large lakes or reservoirs did not affect them. The results indicate that the input meteorological forcing component and the land surface hydrology module provide a framework with which to assess global water resources, with the potential application to investigate the subannual variability in water resources. GSWP2 participants are encouraged to re-run their model using this newly developed meteorological forcing input, which is in identical format to the original GSWP2 forcing input
Immunosuppressants Tacrolimus and Sirolimus revert the cardiac antifibrotic properties of p38-MAPK inhibition in 3D-multicellular human iPSC-heart organoids
Immunosuppressive regimens after a heart transplant can hamper good therapeutic progressions in fibrosis. 京都大学プレスリリース. 2022-11-15.より本物の心臓に近い心臓オルガノイドによる薬剤の効果を評価するシステム --細胞間コミュニケーションを研究できるツールの開発--. 京都大学プレスリリース. 2022-11-21.Cardiac reactive fibrosis is a fibroblast-derived maladaptive process to tissue injury that exacerbates an uncontrolled deposition of large amounts of extracellular matrix (ECM) around cardiomyocytes and vascular cells, being recognized as a pathological entity of morbidity and mortality. Cardiac fibrosis is partially controlled through the sustained activation of TGF-β1 through IL-11 in fibroblasts. Yet, preclinical studies on fibrosis treatment require human physiological approaches due to the multicellular crosstalk between cells and tissues in the heart. Here, we leveraged an iPSC-derived multi-lineage human heart organoid (hHO) platform composed of different cardiac cell types to set the basis of a preclinical model for evaluating drug cardiotoxicity and assessing cardiac fibrosis phenotypes. We found that the inhibition of the p38-MAPK pathway significantly reduces COL1A1 depositions. Yet, concomitant treatment with organ-rejection immunosuppressant drugs Tacrolimus or Sirolimus reverts this effect, opening new questions on the clinical considerations of combined therapies in reducing fibrosis after organ transplantation
Illustrating a new global-scale approach to estimating potential reduction in fish species richness due to flow alteration
Changes in river discharge due to human activities and climate change would
affect the sustainability of freshwater ecosystems. To globally assess how
changes in river discharge will affect the future status of freshwater
ecosystems, global-scale hydrological simulations need to be connected with
a model to estimate the durability of freshwater ecosystems. However, the
development of this specific modelling combination for the global scale is
still in its infancy. In this study, two statistical methods are introduced
to link flow regimes to fish species richness (FSR): one is based on a
linear relationship between FSR and mean river discharge (hereafter, FSR-MAD
method), and the other is based on a multi-linear relationship between FSR
and ecologically relevant flow indices involving several other flow
characteristics and mean river discharge (FSR-FLVAR method). The FSR-MAD
method has been used previously in global simulation studies. The FSR-FLVAR
method is newly introduced here. These statistical methods for estimating
FSR were combined with a set of global river discharge simulations to
evaluate the potential impact of climate-change-induced flow alterations on
FSR changes. Generally, future reductions in FSR with the FSR-FLVAR method
are greater and much more scattered than with the FSR-MAD method. In arid
regions, both methods indicate reductions in FSR because mean discharge is
projected to decrease from past to future, although the magnitude of
reductions in FSR is different between the two methods. In contrast, in
heavy-snow regions a large reduction in FSR is shown by the FSR-FLVAR method
due to increases in the frequency of low and high flows. Although further
research is clearly needed to conclude which method is more appropriate,
this study demonstrates that the FSR-FLVAR method could produce considerably
different results when assessing the global role of flow alterations in
changing freshwater ecosystems
The effects of annual precipitation and mean air temperature on annual runoff in global forest regions
Abstract Changing trends in runoff and water balance under a warming atmosphere are a major subject of interest in recent climatic and hydrological research. Forest basins represent the most complex systems including critical hydrological processes. In this study, we investigate the relationship between annual total runoff (Q), precipitation (P), and mean temperature (T) using observed data collected from 829 (forest) site years around the world. It is shown that the strong linear relationship between annual P and Q is a function of mean T. By empirically perturbing observed annual Q and P with T, a set of ΔQ-zero lines are derived for different mean T. To evaluate the extent to which the future changes in annual P and T alter Q, the future projections of ΔP and ΔT under a warming scenario (A1B) from five coupled AOGCMs (Atmosphere-Ocean General Circulation Models) are compared with the empirical ΔQ-zero lines derived in this study. It is found that five AOGCMs show different distributions with respect to the ΔQ-zero lines, which can be attributed to the contrasting dominant sensitivities of various influencing factors to water balance partitioning among models. The knowledge gained in this empirical study is helpful to predict water resources changes under changing climate as well as to interpret hydrologic simulations in AOGCM future projections. Climatic Chang
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Flood risk and climate change: global and regional perspectives
A holistic perspective on changing rainfall-driven flood risk is provided for the late 20th and early 21st centuries. Economic losses from floods have greatly increased, principally driven by the expanding exposure of assets at risk. It has not been possible to attribute rain-generated peak streamflow trends to anthropogenic climate change over the past several decades. Projected increases in the frequency and intensity of heavy rainfall, based on climate models, should contribute to increases in precipitation-generated local flooding (e.g. flash flooding and urban flooding). This article assesses the literature included in the IPCC SREX report and new literature published since, and includes an assessment of changes in flood risk in seven of the regions considered in the recent IPCC SREX report-Africa, Asia, Central and South America, Europe, North America, Oceania and Polar regions. Also considering newer publications, this article is consistent with the recent IPCC SREX assessment finding that the impacts of climate change on flood characteristics are highly sensitive to the detailed nature of those changes and that presently we have only low confidence1 in numerical projections of changes in flood magnitude or frequency resulting from climate change
A gross anatomical study of the styloid process of the temporal bone in Japanese cadavers
Background: The incidence of an elongated styloid process (SP) and average length and diameter of SP have not been reported using Japanese cadavers. Data on the female-to-male ratio of an elongated SP vary. We calculated the average length and diameter of SP in Japanese cadavers and compared SP lengths between sexes.
Materials and methods: Twenty-seven sides (right and left of bodies) in males and 51 sides in females were analyzed. Measurements were obtained from the inferior external acoustic meatus to the distal tip of the SP. SP diameters at the proximal base, midpoint, and distal tip were measured. SP >30 mm was considered elongated. We used Welch’s t-test for the statistical analysis. Fisher’s exact two-tailed test was also performed to analyze the female-to-male elongation ratio. A p-value <0.05 was considered statistically significant.
Results: SP elongation prevalence was 29.5% in our sample. The average full length was 27.04±7.88 mm overall; the average diameters were 5.41±1.77 mm at the proximal base and 2.21±1.22 mm at the distal tip. The average SP measurement was 26.81±5.92 mm in males and 27.16±8.79 mm in females (p=0.74). The female-to-male ratio of SP elongation was 1:2 (p=0.041). Females had longer full lengths of non-elongated SPs than males (p=0.004). Males had wider diameters at the proximal base of elongated SPs than females (p=0.017).
Conclusions: The average length of SP was 27.04 mm in the Japanese population and about 30% of the Japanese presented SP≥30 mm. Male had significantly higher rate than female among the SP≥30 mm, and female had significantly longer SPs than male among the SP<30 mm. Anatomically, the SP gets narrow as distally goes. Our anatomical findings would be beneficial to creating treatment plans, diagnosis, and surgery
GLACE: the global land–atmosphere coupling experiment. Part I: overview
Permission to place copies of these works on this server has been provided by the American Meteorological Society (AMS). The AMS does not guarantee that the copies provided here are accurate copies of the published work. © Copyright 2006 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108, as revised by P.L. 94-553) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form on servers, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. Additional details are provided in the AMS Copyright Policy, available on the AMS Web site located at (http://www.ametsoc.org/AMS) or from the AMS at 617-227-2425 or [email protected] Global Land–Atmosphere Coupling Experiment (GLACE) is a model intercomparison study focusing on a typically neglected yet critical element of numerical weather and climate modeling: land–atmosphere coupling strength, or the degree to which anomalies in land surface state (e.g., soil moisture) can affect rainfall generation and other atmospheric processes. The 12 AGCM groups participating in GLACE performed a series of simple numerical experiments that allow the objective quantification of this element for boreal summer. The derived coupling strengths vary widely. Some similarity, however, is found in the spatial patterns generated by the models, with enough similarity to pinpoint multimodel “hot spots” of land–atmosphere coupling. For boreal summer, such hot spots for precipitation and temperature are found over large regions of Africa, central North America, and India; a hot spot for temperature is also found over eastern China. The design of the GLACE simulations are described in full detail so that any interested modeling group can repeat them easily and thereby place their model’s coupling strength within the broad range of those documented here
向精神薬服用患者の突然死症例におけるカリウムイオンチャネルに関する分子生物学的解析:QT延長症候群関連遺伝子の多型が危険因子となり得るか?
Psychotropic drugs can pose the risk of acquired long QT syndrome (LQTS). Unexpected autopsy-negative sudden death in patients taking psychotropic drugs may be associated with prolonged QT intervals and life-threatening arrhythmias. We analyzed genes that encode for cardiac ion channels and potentially associated with LQTS, examining specifically the potassium channel genes KCNQ1 and KCNH2 in 10 cases of sudden death involving patients administered psychotropic medication in which autopsy findings identified no clear cause of death. We amplified and sequenced all exons of KCNQ1 and KCNH2, identifying G643S, missense polymorphism in KCNQ1, in 6 of the 10 cases. A study analysis indicated that only 11% of 381 healthy Japanese individuals carry this polymorphism. Reports of previous functional analyses indicate that the G643S polymorphism in the KCNQ1 potassium channel protein causes mild IKs channel dysfunction. Our present study suggests that administering psychotropic drug therapy to individuals carrying the G643S polymorphism may heighten the risk of prolonged QT intervals and life-threatening arrhythmias. Thus, screening for the G643S polymorphism before prescribing psychotropic drugs may help reduce the risk of unexpected sudden death2013博士(歯学)松本歯科大
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