251 research outputs found
First Finding of Succulence and C4/CAM-Cycling Photosynthesis in a Grass: Ecophysiology of Spinifex littoreus in Coastal Regions of Taiwan
Spinifex littoreus (Brum. f.) Merr. is a halophytic grass that is distributed on coastal sand dunes in Taiwan (and throughout Southeast Asia). This study is the first report of leaf succulence in a grass, with 64 % of the leaf cross-sectional area occupied by water-storage parenchyma (hydrenchyma). Leaf water content, saturated water content and mesophyll succulence indices were also similar to other reported succulent plants. In addition to the previous report of C4 photosynthesis, the current study found diel acid fluctuation and nocturnal stomatal closure, which indicates CAM photosynthesis (in a CAM-cycling form), thus indicating that S. littoreus is a grass with C4/CAM-cycling photosynthesis. This finding is the first report of any grass with CAM photosynthesis of any kind. The presence of CAM acid fluctuation was found to be associated with exposed areas and at the edges of plant colonies. Also, the presence of CAM acid fluctuation in some populations was not consistent across years, and was not correlated with temperature or precipitation differences. Photosynthetic rates among populations varied, which might either be the result of different environmental conditions, or genotypic variability among populations throughout Taiwan. This study comprises the first report of a succulent grass, and the first report of C4/CAM-cycling photosynthetic pathway in monocots. This plant may have an important prospect as a model organism for studying the regulation and evolutionary history of C4 and CAM photosynthesis, as well as the potential value for experimental breeding programs, improving drought and salt tolerance in cereal crops
Flow network controlled shape transformation of a thin membrane through differential fluid storage and surface expansion
The mechanical properties of a thin, planar material, perfused by an embedded
flow network, can be changed locally and globally by the fluid transport and
storage, resulting in small or large-scale deformation, such as out-of-plane
buckling. Fluid absorption and storage eventually cause the material to locally
swell. Different parts can hydrate and swell unevenly, prompting a differential
expansion of the surface. In order to computationally study the hydraulically
induced differential swelling and buckling of such a membrane, we develop a
network model that describes both the membrane shape and fluid movement,
coupling mechanics with hydrodynamics. We simulate the time-dependent fluid
distribution in the flow network based on a spatially explicit resistor network
model with local fluid-storage capacitance. The shape of the surface is modeled
by a spring network produced by a tethered mesh discretization, in which local
bond rest lengths are adjusted instantaneously according to associated local
fluid content in the capacitors in a quasi-static way. We investigate the
effects of various designs of the flow network, including overall hydraulic
traits (resistance and capacitance) and hierarchical architecture (arrangement
of major and minor veins), on the specific dynamics of membrane shape
transformation. To quantify these effects, we explore the correlation between
local Gaussian curvature and relative stored fluid content in each hierarchy by
using linear regression, which reveals that stronger correlations could be
induced by less densely connected major veins. This flow-controlled mechanism
of shape transformation was inspired by the blooming of flowers through the
unfolding of petals. It can potentially offer insights for other reversible
motions observed in plants induced by differential turgor and water transport
through the xylem vessels, as well as engineering applications
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Grass Evolutionary Lineages Can Be Identified Using Hyperspectral Leaf Reflectance
Abstract:
Hyperspectral remote sensing has the potential to map numerous attributes of the Earth’s surface, including spatial patterns of biological diversity. Grasslands are one of the largest biomes on Earth. Accurate mapping of grassland biodiversity relies on spectral discrimination of endmembers of species or plant functional types. We focused on spectral separation of grass lineages that dominate global grassy biomes: Andropogoneae (C4), Chloridoideae (C4), and Pooideae (C3). We examined leaf reflectance spectra (350–2,500 nm) from 43 grass species representing these grass lineages from four representative grassland sites in the Great Plains region of North America. We assessed the utility of leaf reflectance data for classification of grass species into three major lineages and by collection site. Classifications had very high accuracy (94%) that were robust to site differences in species and environment. We also show an information loss using multispectral sensors, that is, classification accuracy of grass lineages using spectral bands provided by current multispectral satellites is much lower (accuracy of 85.2% and 61.3% using Sentinel 2 and Landsat 8 bands, respectively). Our results suggest that hyperspectral data have an exciting potential for mapping grass functional types as informed by phylogeny. Leaf‐level hyperspectral separability of grass lineages is consistent with the potential increase in biodiversity and functional information content from the next generation of satellite‐based spectrometers
Nordamnacanthal potentiates the cytotoxic effects of tamoxifen in human breast cancer cells
Tamoxifen (TAM) is the mainline drug treatment for breast cancer, despite its side effects and the development of resistance. As an alternative approach, in the present study a novel combination therapy was established through combining TAM with nordamnacanthal (NDAM) in order to investigate the additive effect of these drugs in MCF-7 human breast cancer cells. A significant dose-dependent reduction in cell viability and an increase in apoptosis were observed in the MCF-7 cells cotreated with TAM and NDAM compared with the untreated control cells or the cells treated with TAM and NDAM alone (P<0.05). The cytotoxic influence of the combination of TAM and NDAM was found to be two-fold that of the individual agents. Annexin V/propidium iodide double-staining revealed the typical nuclear features of apoptosis. Furthermore, an increase in the proportion of apoptotic, Annexin V-positive cells was observed with the combination therapy. Moreover, this apoptotic induction was associated with a collapse of the mitochondrial membrane potential and the generation of reactive oxygen species. To the best of our knowledge, the findings of the present study are the first to suggest that combining TAM with NDAM may be a potential combination therapy for the treatment of breast cancer and may have the potential to minimize or eliminate the side effects associated with high doses of TAM
Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC
This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing
Disease burden and related medical costs of rotavirus infections in Taiwan
BACKGROUND: The disease burden and associated medical costs of rotavirus infections in inpatient and outpatient sectors in Taiwan were examined in anticipation of the availability of new rotavirus vaccines. METHODS: The yearly national case number and medical costs for all for inpatients and outpatients with acute gastroenteritis (AGE) were extracted from the Bureau of National Health Insurance database in Taiwan according to ICD-9-CM codes. A retrospective study was also performed using records of children with AGE seen at three hospitals in Taiwan in 2001 to identify laboratory confirmed rotavirus infection cases. The annual incidence and related medical costs of AGE due to rotavirus infection were then estimated. RESULTS: Children <5 years old comprised 83.6% of inpatient and 62.0% of outpatient pediatric AGE cases in Taiwan in 2001. Rotavirus was the most common agent detected among AGE patients in this age group in the three hospitals, and was detected in 32.9% (221/672) of inpatient and 24% (23/96) of outpatient stool specimens tested for microbial etiologies. An estimated 277,400 to 624,892 cases of rotavirus infections sought medical care in Taiwan in 2001, equaling one in 2 to 5 children <5 years old required medical care due to rotavirus infection. The incidence of hospitalization due to rotavirus infections was 1,528–1,997/100,000 for children <5 years old. The total associated medical costs due to rotavirus infection were estimated at US $10–16 millions in Taiwan in 2001. Although the per-capita medical cost of rotavirus infection was lower in Taiwan than in the United States or Hong Kong, the personal economic burden was similar among the three places when normalized for gross national incomes per capita. CONCLUSION: Infections caused by rotavirus constitute an important human and economic burden among young children in Taiwan. A safe and effective vaccine is urgently needed
RRM adjacent TARDBP mutations disrupt RNA binding and enhance TDP-43 proteinopathy
Amyotrophic lateral sclerosis (ALS) presents with focal muscle weakness due to motor neuron degeneration that becomes generalized,leading to death from respiratory failure within 3–5 years from symptom onset. Despite the heterogeneity of aetiology, TDP- 43 proteinopathy is a common pathological feature that is observed in 495% of ALS and tau-negative frontotemporal dementia(FTD) cases. TDP-43 is a DNA/RNA-binding protein that in ALS and FTD translocates from being predominantly nuclear to formdetergent-resistant, hyperphosphorylated aggregates in the cytoplasm of affected neurons and glia. Mutations in TARDBP accountfor 1–4% of all ALS cases and almost all arise in the low complexity C-terminal domain that does not affect RNA binding andprocessing. Here we report an ALS/FTD kindred with a novel K181E TDP-43 mutation that is located in close proximity to the RRM1 domain. To offer predictive gene testing to at-risk family members, we undertook a series of functional studies to characterizethe properties of the mutation. Spectroscopy studies of the K181E protein revealed no evidence of significant misfolding.Although it is unable to bind to or splice RNA, it forms abundant aggregates in transfected cells. We extended our study to includeother ALS-linked mutations adjacent to the RRM domains that also disrupt RNA binding and greatly enhance TDP-43 aggregation,forming detergent-resistant and hyperphosphorylated inclusions. Lastly, we demonstrate that K181E binds to, and sequesters, wild-type TDP-43 within nuclear and cytoplasmic inclusions. Thus, we demonstrate that TDP-43 mutations that disrupt RNAbinding greatly enhance aggregation and are likely to be pathogenic as they promote wild-type TDP-43 to mislocalize andaggregate acting in a dominant-negative manner. This study highlights the importance of RNA binding to maintain TDP-43solubility and the role of TDP-43 aggregation in disease pathogenesis
Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults
Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We
estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from
1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories.
Methods We used data from 3663 population-based studies with 222 million participants that measured height and
weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate
trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children
and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the
individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For schoolaged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference)
and obesity (BMI >2 SD above the median).
Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in
11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed
changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and
140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of
underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and
countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior
probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse
was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of
thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a
posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%)
with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and
obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for
both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such
as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged
children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls
in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and
42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents,
the increases in double burden were driven by increases in obesity, and decreases in double burden by declining
underweight or thinness.
Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an
increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy
nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of
underweight while curbing and reversing the increase in obesit
Use of anticoagulants and antiplatelet agents in stable outpatients with coronary artery disease and atrial fibrillation. International CLARIFY registry
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