Aerosol emissions from biomass burning are of specific interest over the globe due to their strong radiative impacts and climate implications. The present study examines the impact of paddy crop ...residue burning over northern India during the postmonsoon (October–November) season of 2012 on modification of aerosol properties, as well as the long‐range transport of smoke plumes, altitude characteristics, and affected areas via the synergy of ground‐based measurements and satellite observations. During this period, Moderate Resolution Imaging Spectroradiometer (MODIS) images show a thick smoke/hazy aerosol layer below 2–2.5 km in the atmosphere covering nearly the whole Indo‐Gangetic Plains (IGP). The air mass trajectories originating from the biomass‐burning source region over Punjab at 500 m reveal a potential aerosol transport pathway along the Ganges valley from west to east, resulting in a strong aerosol optical depth (AOD) gradient. Sometimes, depending upon the wind direction and meteorological conditions, the plumes also influence central India, the Arabian Sea, and the Bay of Bengal, thus contributing to Asian pollution outflow. The increased number of fire counts (Terra and Aqua MODIS data) is associated with severe aerosol‐laden atmospheres (AOD500 nm > 1.0) over six IGP locations, high values of Ångström exponent (>1.2), high particulate mass 2.5 (PM2.5) concentrations (>100–150 µgm−3), and enhanced Ozone Monitoring Instrument Aerosol Index gradient (~2.5) and NO2 concentrations (~6 × 1015 mol/cm2), indicating the dominance of smoke aerosols from agricultural crop residue burning. The aerosol size distribution is shifted toward the fine‐mode fraction, also exhibiting an increase in the radius of fine aerosols due to coagulation processes in a highly turbid environment. The spectral variation of the single‐scattering albedo reveals enhanced dominance of moderately absorbing aerosols, while the aerosol properties, modification, and mixing atmospheric processes differentiate along the IGP sites depending on the distance from the aerosol source, urban influence, and local characteristics.
Key Points
Satellite and ground‐based monitoring of agriculture fires in northern India
Transport pathways, smoke plume characteristics, and affected areas
Variation of aerosol loading as a function of distance from the source
To investigate the effects of copper (Cu), rice plant (Oryza sativa. L. var. MSE-9) was treated with different Cu concentrations (0, 10, 50 and 100μM) for 5 days in hydroponic condition. Gradual ...decrease in shoot and root growth was observed with the increase of Cu concentration and duration of treatment where maximum inhibition was recorded in root growth. Cu was readily absorbed by the plant though the maximum accumulation was found in root than shoot. Hydrogen peroxide (H2O2) production and lipid peroxidation were found increased with the elevated Cu concentration indicating excess Cu induced oxidative stress. Antioxidant enzymes superoxide dismutase (SOD), guaiacol peroxidase (GPX) and ascorbate peroxidase (APX) and glutathione reductase (GR) were effectively generated at the elevated concentrations of Cu though catalase (CAT) did not show significant variation with respect to control. Ascorbate (ASH), glutathione (GSH) and proline contents were also increased in all the Cu treated plants compared with the control. SOD isoenzyme was greatly affected by higher concentration of Cu and it was consistent with the changes of the activity assayed in solution. The present study confirmed that excess Cu inhibits growth, induced oxidative stress by inducing ROS formation while the stimulated antioxidative system appears adaptive response of rice plant against Cu induced oxidative stress. Moreover proline accumulation in Cu stress plant seems to provide additional defense against the oxidative stress.
► Excess Cu negatively affects growth of the rice plant. ► Damage was more severe in root than shoot. ► Excess Cu led to oxidative stress in rice plant by inducing ROS generation. ► The plant tolerated the oxidative stress by increasing antioxidant defense system. ► Increased level of proline also reflects its association in tolerating the stress.
Abstract On 2022 September 5, Parker Solar Probe (Parker) observed a large solar energetic particle (SEP) event at the unprecedented distance of only 15 R S from the Sun. The observations from the ...Integrated Science Investigation of the Sun (IS⊙IS) obtained over the course of this event are remarkably rich, and an overview is presented here. IS⊙IS is capable of measuring ions from 20 keV to over 100 MeV nuc −1 and electrons from 30 keV to 6 MeV; here, we primarily focus on the proton and helium measurements above 80 keV. Among the surprising results are evidence of inverse velocity dispersion at energies above 1 MeV during the onset of the event, a sharp decrease in the energetic particle intensities at all energies at the interplanetary shock crossing, and repeated short durations of highly anisotropic sunward flow. Many changes in the SEP intensities, anisotropy, and spectral steepness are coincident with solar wind structure boundaries identified using the Parker solar wind magnetic field and plasma data. However, there are significant changes that are not correlated with any clearly visible solar wind variation. The observations presented here serve as an introduction to a complex event with numerous opportunities for future, more in-depth studies.
ABSTRACT
We present the JWST cycle 1 53.8 h medium program FRESCO, short for ‘First Reionization Epoch Spectroscopically Complete Observations’. FRESCO covers 62 arcmin2 in each of the two ...GOODS/CANDELS fields for a total area of 124 arcmin2 exploiting JWST’s powerful new grism spectroscopic capabilities at near-infrared wavelengths. By obtaining ∼2 h deep NIRCam/grism observations with the F444W filter, FRESCO yields unprecedented spectra at R ∼ 1600 covering 3.8–5.0 µm for most galaxies in the NIRCam field of view. This setup enables emission line measurements over most of cosmic history, from strong PAH lines at z ∼ 0.2–0.5, to Pa α and Pa β at z ∼ 1–3, He i and S iii at z ∼ 2.5–4.5, H α and N ii at z ∼ 5–6.5, up to O iii and H β for z ∼ 7–9 galaxies. FRESCO’s grism observations provide total line fluxes for accurately estimating galaxy stellar masses and calibrating slit-loss corrections of NIRSpec/MSA spectra in the same field. Additionally, FRESCO results in a mosaic of F182M, F210M, and F444W imaging in the same fields to a depth of ∼28.2 mag (5σ in 0${_{.}^{\prime\prime}}$32 diameter apertures). Here, we describe the overall survey design and the key science goals that can be addressed with FRESCO. We also highlight several, early science results, including: spectroscopic redshifts of Lyman break galaxies that were identified almost 20 yr ago, the discovery of broad-line active galactic nuclei at z > 4, and resolved Pa α maps of galaxies at z ∼ 1.4. These results demonstrate the enormous power for serendipitous discovery of NIRCam/grism observations.
Background
Physical activity may be beneficial for cognition but mechanisms are unclear. We examined the association between objectively assessed physical activity and brain volume, with a focus on ...the hippocampus region.
Methods
We used data from UK Biobank (n = 5272; aged 55.4 ± 7.5 years; 45.6% men) collected through 2013–2016. Participants wore the Axivity AX3 wrist‐worn triaxial accelerometer for 7 days to assess habitual physical activity. Structural magnetic resonance imaging was performed using a standard Siemens Skyra 3T running VD13A SP4 to obtain images of the brain.
Results
There was an association between physical activity (per SD increase) and grey matter volume after adjustment for a range of covariates, although this association was only detected in older adults (>60 years old). We also observed associations of physical activity with both left (B = 0.52, 95% CI, 0.01, 1.03; P = 0.046) and right hippocampal volume (B = 0.59, 95% CI, 0.08, 1.10; P = 0.024) in covariate‐adjusted models.
Conclusion
In summary, physical activity may play a role in the prevention of neurodegenerative diseases.
The diketopyrrolopyrrole-based copolymers PDPP-BBT and TDPP-BBT were synthesized and used as a donor for bulk heterojunction photovoltaic devices. The photophysical properties of these polymers ...showed absorption in the range 500−600 nm with a maximum peak around 563 nm, while TDPP-BBT showed broadband absorption in the range 620 − 800 nm with a peak around 656 nm. The power conversion efficiencies (PCE) of the polymer solar cells based on these copolymers and 6,6-phenyl C61 butyric acid methyl ester (PCBM) were 0.68% (as cast PDPP-BBT:PCBM), 1.51% (annealed PDPP-BBT:PCBM), 1.57% (as cast TDPP-BBT:PCBM), and 2.78% (annealed TDPP-BBT:PCBM), under illumination of AM 1.5 (100 mW/cm2). The higher PCE for TDPP-BBT-based polymer solar cells has been attributed to the low band gap of this copolymer as compared to PDPP-BBT, which increases the numbers of photogenerated excitons and corresponding photocurrent of the device. These results indicate that PDPP-BBT and TDPP-BBT act as excellent electron donors for bulk heterojunction devices.
We report that the power conversion efficiency (PCE) of the bulk heterojunction organic photovoltaic device based on poly(3-hexylthiophene):6,6-phenyl–C
61–butyric acid methyl ester (P3HT:PCBM) blend ...was improved by incorporating a small molecule
SM having absorption band in the longer wavelength region.
SM is a small molecule containing thienothiadiazole central unit with terminal cyanovinylene 4-nitrophenyl at both sides, which were connected to the central unit via a thiophene ring. The combination of
SM with P3HT and PCBM allows not only a broad band absorption up to longer wavelength, but also tuning the inter-energy level leading to a higher short circuit current (
J
sc) and open circuit voltage (
V
oc). The device based on the as cast P3HT:PCBM:
SM exhibits a PCE of 3.69%, which is higher than the device based on P3HT:PCBM and
SM:PCBM blends. The overall PCE of the device based on thermally annealed blend is further improved up to 4.1%. The improvement of the PCE has been attributed to a better charge transport in the device, due to the increased crystallinity of the blend through thermal annealing.
The photovoltaic device based on P3HT:PCBM:SM ternary blend shows power conversion efficiency of 3.69%, which is further improved to 4.1% after thermal annealing.
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Context. Being the most numerous and oldest stars in the galaxy, M dwarfs are objects of great interest for exoplanet searches. The presence of molecules in their atmosphere complicates our ...understanding of their atmospheric properties. But great advances have recently been made in the modeling of M dwarfs due to the revision of solar abundances. Aims. We aim to determine stellar parameters of M dwarfs using high resolution spectra (R ∼ 90 000) simultaneously in the visible and the near-infrared. The high resolution spectra and broad wavelength coverage provide an unique opportunity to understand the onset of dust and cloud formation at cool temperatures. Furthermore, this study will help in understanding the physical processes which occur in a cool atmospheres, particularly, the redistribution of energy from the optical to the near-infrared. Methods. The stellar parameters of M dwarfs in our sample have been determined by comparing the high resolution spectra both in the optical and in the near-infrared simultaneously observed by CARMENES with the synthetic spectra obtained from the BT-Settl model atmosphere. The detailed spectral synthesis of these observed spectra both in the optical and in the near-infrared helps to understand the missing continuum opacity. Results. For the first time, we derive fundamental stellar parameters of M dwarfs using the high resolution optical and near-infrared spectra simultaneously. We determine Teff, log g and M/H for 292 M dwarfs of spectral type M0 to M9, where the formation of dust and clouds are important. The derived Teff for the sample ranges from 2300 to 4000 K, values of log g ranges from 4.5 ≤ logg ≤ 5.5 and the resulting metallicity ranges from −0.5 ≤ M/H ≤ +0.5. We have also explored the possible differences in Teff, log g and M/H by comparing them with other studies of the same sample of M dwarfs.
Abnormal P-terminal force in lead V1 (PTFV1) is associated with an increased risk of heart failure, stroke, atrial fibrillation, and death.
Our goal was to explore associations of left ventricular ...(LV) diffuse fibrosis with left atrial (LA) function and electrocardiographic (ECG) measures of LA electrical activity.
Patients without atrial fibrillation (n = 91; mean age 59.5 years; 61.5% men; 65.9% white) with structural heart disease (spatial QRS-T angle ≥105° and/or Selvester QRS score ≥5 on ECG) but LV ejection fraction >35% underwent clinical evaluation, cardiac magnetic resonance, and resting ECG. LA function indices were obtained by multimodality tissue tracking using 2- and 4-chamber long-axis images. T1 mapping and late gadolinium enhancement were used to assess diffuse LV fibrosis and presence of scar. P-prime in V1 amplitude (PPaV1) and duration (PPdV1), averaged P-wave-duration, PR interval, and P-wave axis were automatically measured using 12 SLTM algorithm. PTFV1 was calculated as a product of PPaV1 and PPdV1.
In linear regression after adjustment for demographic characteristics, body mass index, maximum LA volume index, presence of scar, and LV mass index, each decile increase in LV interstitial fibrosis was associated with 0.76 mV*ms increase in negative abnormal PTFV1 (95% confidence interval CI -1.42 to -0.09; P = .025), 15.3 ms prolongation of PPdV1 (95% CI 6.9 to 23.8; P = .001) and 5.4 ms prolongation of averaged P-duration (95% CI 0.9-10.0; P = .020). LV fibrosis did not affect LA function. PPaV1 and PTFV1 were associated with an increase in LA volumes and decrease in LA emptying fraction and LA reservoir function.
LV interstitial fibrosis is associated with abnormal PTFV1, prolonged PPdV1, and P-duration, but does not affect LA function.
Melting glaciers are mostly associated with formation of proglacial lakes and the expansion of existing glacial lakes in Himalayan region. These expanding glacial lakes can induce the risk of glacial ...outburst floods that pose a great potential threat to natural resources and human lives. In Sikkim Himalaya, South Lhonak lake (SLL) (5200 masl) is rapidly expanding over the few decades due to the ongoing glacier melting. We recorded that the lake size increased from 0.20 ± 0.020 to 1.31 ± 0.001 km
2
with the length change of 1.6 km during the period from 1976 to 2016. The average rate of expansion was recorded of 0.027 km
2
per year; however, it increased drastically since 2000. The in situ
-
based bathymetric study of SLL showed that the storage volume was 65.81 ± 2.5 million m
3
and maximum and average depths were 131 ± 2.5 and 67.05 ± 2.5 m, respectively. We observed that the substantial calving of ice bodies during the melting seasons and partly from the melting of North Lhonak glacier and flow of the Lhonak lake have contributed in expansion of SLL. We have also proposed an empirical equation of volume–area relationship to calculate the storage capacity of similar moraine-dammed glacial lakes in the Himalaya. In addition, we have suggested effective precautionary and mitigation measures to minimize the risk of GLOFs in future. The present study provides vital inputs for hydrodynamic modelling for flood simulation of potentially vulnerable lakes and to formulate the effective strategies in disaster risk reduction and mitigation plan in minimizing the threat of GLOFs.
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