925 research outputs found
Impact of global warming on the energetics of lower tropospheric ultra-long waves and the Indian summer monsoon
Analyses of 60 years (1949–2008) of monthly energetics of the zonal waves derived from NCEP/NCAR
data indicate that ultra-long waves (waves 1 and 2) dominate the spectrum of lower tropospheric zonal
waves during monsoon season (June–September). Westerlies over the Indian subcontinent are a source
of energy to wave 1. Two oceanic anticyclones, one over Pacific and the other over Atlantic are sources
of energy to wave 2. These two waves are inversely correlated. Climatology of the energetics of ultralong
waves for the two epochs 1949–1978 (CLP1) and 1979–2008 (CLP2) of 30 years indicates that the
intensity of wave 1 has decreased by about 33% whereas the intensity of wave 2 has increased by about
27%. Northward transport of sensible heat during CLP1 changes to southward during CLP2. Larger
generation of zonal mean Available Potential Energy (APE) during CLP2 indicates more heating. A
larger conversion of kinetic energy (KE) of wave 1 into APE of wave 1 leads to weakening of wave 1
during CLP2. In case of wave 2, lower rate of conversion of KE to APE leads to stronger wave 2 during
CLP2
An Efficient, Green Chemical Synthesis of the Malaria\ud Drug, Piperaquine
To provide a robust, efficient synthesis of the malaria drug piperaquine for potential use in resource-poor settings. We used in-process analytical technologies (IPAT; HPLC) and a program of experiments to develop a synthesis of piperaquine that avoids the presence of a toxic impurity in the API and is optimized for overall yield and operational simplicity. A green-chemical synthesis of piperaquine is described that proceeds in 92 – 93 % overall yield. The chemistry is robust and provides very pure piperaquine tetraphosphate salt (> 99.5 %). The overall process utilizes modest amounts (about 8 kg/kg) of 2-propanol and ethyl acetate as the only organic materials not incorporated into the API; roughly 60 % of this waste can be recycled into the production process. This process also completely avoids the formation of a toxic impurity commonly seen in piperaquine that is otherwise difficult to remove. An efficient synthesis of piperaquine is described that may be useful for application in resource-poor settings as a means of expanding access to and reducing the cost of ACTs
Characterizing the Entities in Harmful Memes: Who is the Hero, the Villain, the Victim?
Memes can sway people's opinions over social media as they combine visual and
textual information in an easy-to-consume manner. Since memes instantly turn
viral, it becomes crucial to infer their intent and potentially associated
harmfulness to take timely measures as needed. A common problem associated with
meme comprehension lies in detecting the entities referenced and characterizing
the role of each of these entities. Here, we aim to understand whether the meme
glorifies, vilifies, or victimizes each entity it refers to. To this end, we
address the task of role identification of entities in harmful memes, i.e.,
detecting who is the 'hero', the 'villain', and the 'victim' in the meme, if
any. We utilize HVVMemes - a memes dataset on US Politics and Covid-19 memes,
released recently as part of the CONSTRAINT@ACL-2022 shared-task. It contains
memes, entities referenced, and their associated roles: hero, villain, victim,
and other. We further design VECTOR (Visual-semantic role dEteCToR), a robust
multi-modal framework for the task, which integrates entity-based contextual
information in the multi-modal representation and compare it to several
standard unimodal (text-only or image-only) or multi-modal (image+text) models.
Our experimental results show that our proposed model achieves an improvement
of 4% over the best baseline and 1% over the best competing stand-alone
submission from the shared-task. Besides divulging an extensive experimental
setup with comparative analyses, we finally highlight the challenges
encountered in addressing the complex task of semantic role labeling within
memes.Comment: Accepted at EACL 2023 (Main Track). 9 Pages (main content),
Limitations, Ethical Considerations + 4 Pages (Refs.) + Appendix; 8 Figures;
5 Tables; Paper ID: 80
A methodology pruning the search space of six compiler transformations by addressing them together as one problem and by exploiting the hardware architecture details
Today’s compilers have a plethora of optimizations-transformations to choose from, and the correct choice, order as well parameters of transformations have a significant/large impact on performance; choosing the correct order and parameters of optimizations has been a long standing problem in compilation research, which until now remains unsolved; the separate sub-problems optimization gives a different schedule/binary for each sub-problem and these schedules cannot coexist, as by refining one degrades the other. Researchers try to solve this problem by using iterative compilation techniques but the search space is so big that it cannot be searched even by using modern supercomputers. Moreover, compiler transformations do not take into account the hardware architecture details and data reuse in an efficient way. In this paper, a new iterative compilation methodology is presented which reduces the search space of six compiler transformations by addressing the above problems; the search space is reduced by many orders of magnitude and thus an efficient solution is now capable to be found. The transformations are the following: loop tiling (including the number of the levels of tiling), loop unroll, register allocation, scalar replacement, loop interchange and data array layouts. The search space is reduced (a) by addressing the aforementioned transformations together as one problem and not separately, (b) by taking into account the custom hardware architecture details (e.g., cache size and associativity) and algorithm characteristics (e.g., data reuse). The proposed methodology has been evaluated over iterative compilation and gcc/icc compilers, on both embedded and general purpose processors; it achieves significant performance gains at many orders of magnitude lower compilation time
Regression Analysis of Wetting Characteristics for Different Random Surface Roughness of Polydimethylsiloxane Using Sandpapers
This is the author accepted manuscript. The final version is available on open access from Elsevier via the DOI in this recordData Availability Statement:
The data that support the findings of this study are available from the corresponding author upon reasonable request.This paper studies various wetting characteristics on different surfaces of Polydimethylsiloxane (PDMS) polymer. The random roughness of the surface is engineered by using sandpapers to introduce different order of hydrophobic properties to understand the temporal evolution of drying droplets. We develop statistical models to predict temporal evolution of the base diameter, height, surface, and contact angle of drying droplets with varying grit size or surface roughness. Five different robust polynomial regression models have been compared for the prediction of three dependent variables - base diameter, height, and surface of drying droplets for random rough surfaces. In a nutshell, we here identify the best statistical model to capture the dynamics of drying droplets on hydrophobic surfaces of random roughness characteristics.SERB, IndiaEuropean Regional Development Fund (ERDF
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Continuing mortality of vultures in India associated with illegal veterinary use of diclofenac and a potential threat from nimesulide
AbstractThe collapse of South Asia's Gyps vulture populations is attributable to the veterinary use of the non-steroidal anti-inflammatory drug (NSAID) diclofenac. Vultures died after feeding on carcasses of recently-medicated animals. The governments of India, Nepal and Pakistan banned the veterinary use of diclofenac in 2006. We analysed results of 62 necropsies and 48 NSAID assays of liver and/or kidney for vultures of five species found dead in India between 2000 and 2012. Visceral gout and diclofenac were detected in vultures from nine states and three species: Gyps bengalensis, Gyps indicus and Gyps himalayensis. Visceral gout was found in every vulture carcass in which a measurable level of diclofenac was detected. Meloxicam, an NSAID of low toxicity to vultures, was found in two vultures and nimesulide in five vultures. Nimesulide at elevated tissue concentrations was associated with visceral gout in four of these cases, always without diclofenac, suggesting that nimesulide may have similar toxic effects to those of diclofenac. Residues of meloxicam on its own were never associated with visceral gout. The proportion of Gyps vultures found dead in the wild in India with measurable levels of diclofenac in their tissues showed a modest and non-significant decline since the ban on the veterinary use of diclofenac. The prevalence of visceral gout declined less, probably because some cases of visceral gout from 2008 onwards were associated with nimesulide rather than diclofenac. Veterinary use of nimesulide is a potential threat to the recovery of vulture populations.Financial support and assistance for the project from the Director, Indian Veterinary Research Institute (IVRI), the UK Government’s Darwin Initiative and the Royal Society for the Protection of Birds is gratefully acknowledged.This is the accepted manuscript. The final version is available from Cambridge University Press via http://dx.doi.org/10.1017/S003060531500037
Oncolytic H-1 Parvovirus Hijacks Galectin-1 to Enter Cancer Cells
Clinical studies in glioblastoma and pancreatic carcinoma patients strongly support the further development of H-1 protoparvovirus (H-1PV)-based anticancer therapies. The identification of cellular factors involved in the H-1PV life cycle may provide the knowledge to improve H-1PV anticancer potential. Recently, we showed that sialylated laminins mediate H-1PV attachment at the cell membrane. In this study, we revealed that H-1PV also interacts at the cell surface with galectin-1 and uses this glycoprotein to enter cancer cells. Indeed, knockdown/out of LGALS1, the gene encoding galectin-1, strongly decreases the ability of H-1PV to infect and kill cancer cells. This ability is rescued by the re-introduction of LGALS1 into cancer cells. Pre-treatment with lactose, which is able to bind to galectins and modulate their cellular functions, decreased H-1PV infectivity in a dose dependent manner. In silico analysis reveals that LGALS1 is overexpressed in various tumours including glioblastoma and pancreatic carcinoma. We show by immunohistochemistry analysis of 122 glioblastoma biopsies that galectin-1 protein levels vary between tumours, with levels in recurrent glioblastoma higher than those in primary tumours or normal tissues. We also find a direct correlation between LGALS1 transcript levels and H-1PV oncolytic activity in 53 cancer cell lines from different tumour origins. Strikingly, the addition of purified galectin-1 sensitises poorly susceptible GBM cell lines to H-1PV killing activity by rescuing cell entry. Together, these findings demonstrate that galectin-1 is a crucial determinant of the H-1PV life cycle.publishedVersio
Crystal structure of 4-({(1E,2E)-3-[3-(4-fluorophenyl)- 1-isopropyl-1H-indol-2-yl]allylidene}amino)-1H- 1,2,4-triazole-5(4H)-thione
The asymmetric unit of the titled compound, C22H20FN5S, comprises two
independent molecules (A and B), both of which have a trans conformation with
respect to the methene C C [1.342 (2) and 1.335 (2) A ° ] and the acyclic N C
[1.283 (2) and 1.281 (2) A ° ] bonds. In molecule A, the triazole ring makes
dihedral angles of 55.01 (12) and 18.17 (9)� with the benzene and indole rings,
respectively. The corresponding dihedral angles for molecule B are 54.54 (11)
and 14.60 (10)�, respectively. In the crystal, molecules are consolidated into –A–
B–A–B– chains along [010] via N—H� � �N hydrogen bonds. The chains are
further linked into layers parallel to the ac plane via �–� interactions involving
inversion-related triazole rings [centroid–centroid distances = 3.3436 (11)–
3.4792 (13) A ° ]
INSPECT: Investigating Supply Chain and Cyber-Physical Security of Battery Systems
Battery-operated applications have been ubiquitous all over the world ranging from power-intensive electric cars down to low-power smart terminals and embedded devices. Meanwhile, serious incidents around batteries such as swelling, fire, and explosion have been witnessed, which resulted in horribly huge financial and even life loss. People used to attribute such aftermaths to unintentional design mistakes or insufficient quality inspection of original battery manufacturers. However, this is not fair anymore today given the convoluted battery supply chain and the extended cyber-physical attack surface of battery management systems (BMS). In this paper, we will focus on the authenticity and assurance of prevalent (Li-ion) battery instances. We look into battery authenticity by modeling the contemporary battery supply chain and discussing practical concerns such as rewrapping and recycling in-depth at each stage. As for battery assurance, we consider emerging attack vectors that can compromise the confidentiality, integrity, and availability of the microelectronic BMS. Besides, real-world attack examples are highlighted to reflect the capabilities of advanced adversaries. Moreover, promising countermeasures regarding the detection and avoidance of threats on both battery authenticity and assurance are presented, such that researchers will gain insights into how the problem could be addressed/alleviated. We also provide our perspectives on the vulnerabilities of battery systems and their consequent impacts as well as our point of view on potential countermeasure techniques
Rapidly Decaying Supernova 2010X: A Candidate ".Ia" Explosion
We present the discovery, photometric and spectroscopic follow-up
observations of SN 2010X (PTF 10bhp). This supernova decays exponentially with
tau_d=5 days, and rivals the current recordholder in speed, SN 2002bj. SN 2010X
peaks at M_r=-17mag and has mean velocities of 10,000 km/s. Our light curve
modeling suggests a radioactivity powered event and an ejecta mass of 0.16
Msun. If powered by Nickel, we show that the Nickel mass must be very small
(0.02 Msun) and that the supernova quickly becomes optically thin to
gamma-rays. Our spectral modeling suggests that SN 2010X and SN 2002bj have
similar chemical compositions and that one of Aluminum or Helium is present. If
Aluminum is present, we speculate that this may be an accretion induced
collapse of an O-Ne-Mg white dwarf. If Helium is present, all observables of SN
2010X are consistent with being a thermonuclear Helium shell detonation on a
white dwarf, a ".Ia" explosion. With the 1-day dynamic-cadence experiment on
the Palomar Transient Factory, we expect to annually discover a few such
events.Comment: 6 pages, 5 figures; Minor Changes; Note correction in Fig 4 caption;
published by ApJ
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