julilili42/papers huggingface dataset:
Immersed solutions of Plateau's problem for piecewise smooth boundary curves with small total curvature
2022-03-13

We provide a new proof of the classical result that any closed rectifiable Jordan curve Gamma in space being piecewise of class C^2 bounds at least one immersed minimal surface of disc-type, under the additional assumption that the total curvature of Gamma is smaller than 6*Pi. In contrast to the methods due to Osserman, Gulliver and Alt, our proof relies on a polygonal approximation technique, using the existence of immersed solutions of Plateau's problem for polygonal boundary curves, provided by the first author's accomplishment of Garnier's ideas.
Semistability of restricted tangent bundles and a question of I. Biswas
2022-03-13

Let M be a complex projective manifold with the property that for any compact Riemann surface C and holomorphic map f: C -&gt; M the pullback of the tangent bundle of M is semistable. We prove that in this case M is a curve or a finite etale quotient of an abelian variety answering a conjecture of I. Biswas.
Maximizing the Total Resolution of Graphs
2022-03-13

A major factor affecting the readability of a graph drawing is its resolution. In the graph drawing literature, the resolution of a drawing is either measured based on the angles formed by consecutive edges incident to a common node (angular resolution) or by the angles formed at edge crossings (crossing resolution). In this paper, we evaluate both by introducing the notion of "total resolution", that is, the minimum of the angular and crossing resolution. To the best of our knowledge, this is the first time where the problem of maximizing the total resolution of a drawing is studied. The main contribution of the paper consists of drawings of asymptotically optimal total resolution for complete graphs (circular drawings) and for complete bipartite graphs (2-layered drawings). In addition, we present and experimentally evaluate a force-directed based algorithm that constructs drawings of large total resolution.
Propagators in lattice Coulomb gauge and confinement mechanisms
2022-03-13

We discuss the gluon propagator in 3- and 4-dimensional Yang-Mills theories in Coulomb gauge and compare it with the corresponding Landau gauge propagator, showing that for both the relevant IR mass scale coincides. We also report preliminary results on Coulomb gauge ghost form factor and quark propagators and give a comment on the gluon propagator's strong coupling limit.
4U 0115+63: phase lags and cyclotron resonant scattering
2022-03-13

High mass X-ray binaries are among the brightest objects of our Galaxy in the high energy domain (0.1-100 keV). Despite our relatively good knowledge of their basic emission mechanisms, the complex problem of understanding their time and energy dependent X-ray emission is not completely solved. In this paper, we study the energy dependent pulse profiles of the high mass X-ray binary pulsar 4U 0115+63 to investigate how they are affected by cyclotron resonant scattering. We analyze archival BeppoSAX and RXTE observations performed during the giant outburst of the source which occurred in 1999. We exploit a cross correlation technique to compare the pulse profiles in different energy ranges and develop a relativistic ray-tracing model to interpret our findings. We also study the phase dependency of the cyclotron absorption features by performing phase resolved spectroscopy. The pulse profiles of 4U 0115+63 displayed clear "phase-lags" at energies close to those of the cyclotron absorption features that characterize the X-ray emission of the source. We reproduce qualitatively this phenomenon by assuming an energy dependent beaming of the emission from the column surface and verify that our model is also compatible with the results of phase resolved spectral analysis. We showed that cyclotron resonant scattering affects the pulse profile formation mechanisms in a complex way, which necessitates both improvements in the modeling and the study of other sources to be better understood.
The role of Mie scattering in the seeding of matter-wave superradiance
2022-03-13

Matter-wave superradiance is based on the interplay between ultracold atoms coherently organized in momentum space and a backscattered wave. Here, we show that this mechanism may be triggered by Mie scattering from the atomic cloud. We show how the laser light populates the modes of the cloud, and thus imprints a phase gradient on the excited atomic dipoles. The interference with the atoms in the ground state results in a grating, that in turn generates coherent emission, contributing to the backward light wave onset. The atomic recoil 'halos' created by the scattered light exhibit a strong anisotropy, in contrast to single-atom scattering.
Black holes in galaxies: Environmental impact on gravitational-wave generation and propagation
2022-03-14

We introduce a family of solutions of Einstein's gravity minimally coupled to\\nan anisotropic fluid, describing asymptotically flat black holes with "hair"\\nand a regular horizon. These spacetimes can describe the geometry of galaxies\\nharboring supermassive black holes, and are extensions of Einstein clusters to\\ninclude horizons. They are useful to constrain the environment surrounding\\nastrophysical black holes, using electromagnetic or gravitational-wave\\nobservations. We compute the main properties of the geometry, including the\\ncorrections to the ringdown stage induced by the external matter and fluxes by\\norbiting particles. The leading order effect to these corrections is a\\ngravitational-redshift, but gravitational-wave propagation is affected by the\\ngalactic potential in a nontrivial way, and may be characterized with future\\nobservatories.\\n
Realizing Distance-Selective Interactions in a Rydberg-Dressed Atom Array
2022-03-14

Measurement-based quantum computing relies on the rapid creation of large-scale entanglement in a register of stable qubits. Atomic arrays are well suited to store quantum information, and entanglement can be created using highly-excited Rydberg states. Typically, isolating pairs during gate operation is difficult because Rydberg interactions feature long tails at large distances. Here, we engineer distance-selective interactions that are strongly peaked in distance through off-resonant laser coupling of molecular potentials between Rydberg atom pairs. Employing quantum gas microscopy, we verify the dressed interactions by observing correlated phase evolution using many-body Ramsey interferometry. We identify atom loss and coupling to continuum modes as a limitation of our present scheme and outline paths to mitigate these effects, paving the way towards the creation of large-scale entanglement.
Multimode Vibrational Strong Coupling of Methyl Salicylate to a Fabry−Perot Microcavity
2022-03-14

The strong coupling of an IR-active molecular transition with an optical mode of the cavity results in vibrational polaritons, which opens a new way to control chemical reactivity via confined electromagnetic fields of the cavity. In this study, we design a voltage-tunable open microcavity and we show the formation of multiple vibrational polaritons in methyl salicylate. A Rabi splitting and polariton anticrossing behavior is observed when the cavity mode hybridizes with the C═O stretching vibration of methyl salicylate. Furthermore, the proposed theoretical model based on coupled harmonic oscillators reveals that the absorption of uncoupled molecules must also be considered to model the experimental spectra properly and that simultaneous coupling of multiple molecular vibrations to the same cavity mode has a significant influence on the transmission spectral profile.
The impact of the cyanobacterial carbon‐regulator protein SbtB and of the second messengers cAMP and c‐di‐AMP on CO2‐dependent gene expression
2022-03-14

Summary The amount of inorganic carbon (C i ) fluctuates in aquatic environments. Cyanobacteria evolved a C i ‐concentrating mechanism (CCM) that is regulated at different levels. The regulator SbtB binds to the second messengers cAMP or c‐di‐AMP and is involved in acclimation to low C i (LC) in Synechocystis sp. PCC 6803. Here, we investigated the role of SbtB and of associated second messengers at different C i conditions. The transcriptome of wild‐type (WT) Synechocystis and the Δ sbtB mutant were compared with Δ cya1 , a mutant defective in cAMP production, and Δ dacA , a mutant defective in generating c‐di‐AMP. A defined subset of LC‐regulated genes in the WT was already changed in Δ sbtB under high C i (HC) conditions. This response of Δ sbtB correlated with a diminished induction of many CCM‐associated genes after LC shift in this mutant. The Δ cya1 mutant showed less deviation from WT, whereas Δ dacA induced CCM‐associated genes under HC. Metabolome analysis also revealed differences between the strains, whereby Δ sbtB showed slower accumulation of 2‐phosphoglycolate and Δ dacA differences among amino acids compared to WT. Collectively, these results indicate that SbtB regulates a subset of LC acclimation genes while c‐di‐AMP and especially cAMP appear to have a lesser impact on gene expression under different C i availabilities.
Gefitinib-Tamoxifen Hybrid Ligands as Potent Agents against Triple-Negative Breast Cancer
2022-03-14

Anticancer drug conjugates may benefit from simultaneous action at two targets potentially overcoming the drawbacks of current cancer treatment, such as insufficient efficacy, high toxicity, and development of resistance. Compared to a combination of two single-target drugs, they may offer an advantage of pharmacokinetic simplicity and fewer drug-drug interactions. Here, we report a series of compounds connecting tamoxifen or endoxifen with the EGFR-inhibitor gefitinib via a covalent linkage. These hybrid ligands retain both ER antagonist activity and EGFR inhibition. The most potent analogues exhibited single-digit nanomolar activities at both targets. The amide-linked endoxifen-gefitinib drug conjugates <b>17b</b> and <b>17c</b> demonstrated the most favorable anti-cancer profile in cellular viability assays on MCF7, MDA-MB-231, MDA-MB-468, and BT-549 breast cancer cells. Most importantly, in TNBC cells <b>17b</b> and <b>17c</b> displayed nanomolar IC<sub>50</sub>-values (380 nM - 970 nM) and were superior in their anti-cancer activity compared to their control compounds and combinations thereof.
Mechanical Forces Govern Interactions of Host Cells with Intracellular Bacterial Pathogens
2022-03-14

To combat infectious diseases, it is important to understand how host cells interact with bacterial pathogens. Signals conveyed from pathogen to host, and vice versa, may be either chemical or mechanical.
Effect and Mechanisms of Antibacterial Peptide Fraction from Mucus of C. aspersum against Escherichia coli NBIMCC 8785
2022-03-14

Peptides isolated from the mucus of Cornu aspersum could be prototypes for antibiotics against pathogenic bacteria. Information regarding the mechanisms, effective concentration, and methods of application is an important tool for therapeutic, financial, and ecological regulation and a holistic approach to medical treatment. A peptide fraction with MW &lt; 10 kDa was analyzed by MALDI-TOF-TOF using AutoflexTM III. The strain Escherichia coli NBIMCC 8785 (18 h and 48 h culture) was used. The changes in bacterial structure and metabolic activity were investigated by SEM, fluorescent, and digital image analysis. This peptide fraction had high inhibitory effects in surface and deep inoculations of E. coli of 1990.00 and 136.13 mm2/mgPr/μMol, respectively, in the samples. Thus, it would be effective in the treatment of infections involving bacterial biofilms and homogenous cells. Various deformations of the bacteria and inhibition of its metabolism were discovered and illustrated. The data on the mechanisms of impact of the peptides permitted the formulation of an algorithm for the treatment of infections depending on the phase of their development. The decrease in the therapeutic concentrations will be more sparing to the environment and will lead to a decrease in the cost of the treatment.
Midazolam at Low Nanomolar Concentrations Affects Long-term Potentiation and Synaptic Transmission Predominantly via the α1–γ-Aminobutyric Acid Type A Receptor Subunit in Mice
2022-03-14

Background Midazolam amplifies synaptic inhibition via different γ-aminobutyric acid type A (GABA A ) receptor subtypes defined by the presence of α 1 -, α 2 -, α 3 -, or α 5 -subunits in the channel complex. Midazolam blocks long-term potentiation and produces postoperative amnesia. The aims of this study were to identify the GABA A receptor subtypes targeted by midazolam responsible for affecting CA1 long-term potentiation and synaptic inhibition in neocortical neurons. Methods The effects of midazolam on hippocampal CA1 long-term potentiation were studied in acutely prepared brain slices of male and female mice. Positive allosteric modulation on GABA A receptor–mediated miniature inhibitory postsynaptic currents was investigated in organotypic slice cultures of the mouse neocortex. In both experiments, wild-type mice and GABA A receptor knock-in mouse lines were compared in which α 1 -, α 5 -, α 1/2/3 -, α 1/3/5 - and α 2/3/5 -GABA A receptor subtypes had been rendered benzodiazepine-insensitive. Results Midazolam (10 nM) completely blocked long-term potentiation (mean ± SD, midazolam, 98 ± 11%, n = 14/8 slices/mice vs . control 156 ± 19%, n = 20/12; P &lt; 0.001). Experiments in slices of α 1 -, α 5 -, α 1/2/3 -, α 1/3/5 -, and α 2/3/5 –knock-in mice revealed a dominant role for the α 1 -GABA A receptor subtype in the long-term potentiation suppressing effect. In slices from wild-type mice, midazolam increased (mean ± SD) charge transfer of miniature synaptic events concentration-dependently (50 nM: 172 ± 71% [n = 10/6] vs . 500 nM: 236 ± 54% [n = 6/6]; P = 0.041). In α 2/3/5 –knock-in mice, charge transfer of miniature synaptic events did not further enhance when applying 500 nM midazolam (50 nM: 171 ± 62% [n = 8/6] vs . 500 nM: 175 ± 62% [n = 6/6]; P = 0.454), indicating two different binding affinities for midazolam to α 2/3/5 - and α 1 -subunits. Conclusions These results demonstrate a predominant role of α 1 -GABA A receptors in the actions of midazolam at low nanomolar concentrations. At higher concentrations, midazolam also enhances other GABA A receptor subtypes. α 1 -GABA A receptors may already contribute at sedative doses to the phenomenon of postoperative amnesia that has been reported after midazolam administration. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New
Palaeoecological Implications of Lower-Middle Triassic Stromatolites and Microbe-Metazoan Build-Ups in the Germanic Basin: Insights into the Aftermath of the Permian–Triassic Crisis
2022-03-14

Following the end-Permian crisis, microbialites were ubiquitous worldwide. For instance, Triassic deposits in the Germanic Basin provide a rich record of stromatolites as well as of microbe-metazoan build-ups with nonspicular demosponges. Despite their palaeoecological significance, however, all of these microbialites have only rarely been studied. This study aims to fill this gap by examining and comparing microbialites from the Upper Buntsandstein (Olenekian, Lower Triassic) and the lower Middle Muschelkalk (Anisian, Middle Triassic) in Germany. By combining analytical petrography (optical microscopy, micro X-ray fluorescence, and Raman spectroscopy) and geochemistry (δ13Ccarb, δ18Ocarb), we show that all the studied microbialites formed in slightly evaporitic environments. Olenekian deposits in the Jena area and Anisian strata at Werbach contain stromatolites. Anisian successions at Hardheim, in contrast, host microbe-metazoan build-ups. Thus, the key difference is the absence or presence of nonspicular demosponges in microbialites. It is plausible that microbes and nonspicular demosponges had a mutualistic relationship, and it is tempting to speculate that the investigated microbial-metazoan build-ups reflect an ancient evolutionary and ecological association. The widespread occurrence of microbialites (e.g., stromatolites/microbe-metazoan build-ups) after the catastrophe may have resulted from suppressed ecological competition and the presence of vacant ecological niches. The distribution of stromatolites and/or microbe-metazoan build-ups might have been controlled by subtle differences in salinity and water depth, the latter influencing hydrodynamic processes and nutrient supply down to the microscale. To obtain a more complete picture of the distribution of such build-ups in the earth’s history, more fossil records need to be (re)investigated. For the time being, environmental and taphonomic studies of modern nonspicular demosponges are urgently required.
PotN represents a novel energy‐state sensing PII subfamily, occurring in firmicutes
2022-03-14

PII proteins are signal processor proteins that regulate the cellular metabolism of Bacteria, Archea and plant chloroplasts typically in response to the cellular nitrogen status. Here, we report the first biochemical characterization of a novel PII‐like protein PotN from Lentilactobacillus hilgardii . PotN is encoded in an operon together with the potABCD genes, encoding the ABC transporter for spermidine/putrescine. Like canonical PII proteins, the native PotN has a trimeric structure and competitively binds ATP and ADP, but it does not bind 2‐oxoglutarate. Immunoprecipitation and pull‐down experiments revealed that PotN is associated in vivo with the transcriptional regulator GlnR and the beta‐subunit of pyruvate/2‐oxoglutarate/acetoin dehydrogenase AcoB. Moreover, in vitro assays revealed that the ATPase domain of PotA also is able to interact with PotN. Interaction analyses demonstrated that PotN preferentially associates with PotA in the ADP state, whereas it binds to GlnR at elevated ATP levels. This suggests that PotN regulates the transport of polyamines and GlnR‐dependent gene expression in response to the energy availability for the cell.
Religion, Alchemy, and Medicine in South India
2022-03-14

Siddha traditions are a pan-Indian phenomenon, as we know from David White's seminal study, The Alchemical Body: Siddha Traditions in Medieval India (1996).1The term siddha has been applied to several groups or unorthodox sects practicing tantra, yoga, and alchemy with the objective of attaining perfection and immortality, existing during various periods but culminating after the twelfth century CE.2Among these, the Tamil siddha school had its early origins around the eighth century CE, when Tirumūlar composed the Tirumantiram, a composition that laid out a variant of the Tamil siddha tradition.The Tirumantiram's 3,000 verses describe the esoteric principles of awakening the "serpent power" (kuṇḍalinī), ways of uniting with the god Śiva and attaining immortality through yogic discipline.3This indicates that the Tamil siddha tradition is closely related to Vajrayāna Buddhism, Śaivite tantra, bhakti, Haṭhayoga, and Indian alchemical traditions.4Significantly, Tamil siddha traditions are today seen as the source of inspiration for and origin of siddha medicine, the medical practice and system officially recognized by the Indian government under its Ministry of AYUSH.5 Despite a wide range of sources, however, scholarly volumes dedicated to Tamil siddha traditions and siddha medicine are still rare.In particular, 1 This special issue and the workshop from which its papers have originated have been funded by the DFG (Deutsche Forschungsgemeinschaft) and are part of the work conducted by the SFB 1070 "ResourceCultures" and its subproject C06 titled "The ResourceComplex Health and Body using the Example of Unani Medicine in South India." 2 White 1996, 2;Little 2003, 14. 3 Wittich 2022. 4 Shulman 1991, 55; Little 2003.5 AYUSH is the acronym for the Ministry of Ayurveda, Yoga, Naturopathy, Unani, Siddha, and Homeopathy, whose mission is the development, education, research, and dissemination of indigenous alternative medicine systems in India.
Green lubricants production from Nile tilapia waste and prediction of physical properties through molecular dynamics simulations
2022-03-14

Abstract Fish farming is a worldwide growing activity and a large amount of residues is produced in this process. The present work describes a cleaner and sustainable way to produce new lubricants from fish waste oil. Oil extracted from the Nile tilapia ( Oreochromis niloticus ) viscera was utilized as raw material to produce basic oil for lubricants. The products were synthesized by esterification with polyols, trimethylolpropane (TMP) and pentaerythritol (PE), using p‐toluenesulfonic acid (p‐TSA) as catalyst. The synthesized esters were characterized by infrared (IR) and nuclear magnetic resonance (NMR). Computational methods were used to predict the physical characteristics of the material. In addition, the main physicochemical properties were evaluated, as well as the thermal behavior and toxicity of the products against Artemia salina . The synthesized esters showed high viscosity indexes (VI &gt; 150) and viscosities that fit the degree of application ISO‐46 and 150. Molecular dynamics simulations indicated that at room temperature the lubricants Tilapia fatty acid ‐ trimethylolpropane ester (T‐TMPE) and Tilapia fatty acid ‐ pentaerythritol ester (T‐PEE) are in liquid and gel states, respectively, confirming the experimental data. The products did not present toxicity against A. salina . In this research, we reinforce the potential of using tilapia oil from waste to produce green lubricants as a strategy to reduce damage to the environment, as well as the use of computational methods that collaborate to predict physical properties of lubricants.
Predictors of the Success of Natural Regeneration in a Himalayan Treeline Ecotone
2022-03-14

The sensitivity and response of climatic treelines in the Himalayas to climate change is still being debated. Regeneration of tree species in the treeline ecotone is considered a sensitivity indicator and thus of great scientific interest. The aim of this study is to detect predictor variables for regeneration densities of the major tree species in central Himalayan treeline ecotones (Abies spectabilis, Betula utilis, Rhododendron campanulatum), analysing five development stages from seedling to mature tree. We applied negative binomial generalized linear models with predictors selected from a wide range of soil, topography, climate and stand characteristic variables. We found considerably varying predictors across the tree species and their stages of development. Soil conditions, topography and climate, as well as competing and facilitating tree species, had high predictive power for population densities. These predictors were clearly species- and development stage-specific. Predictors’ spatial- and development-specific heterogeneity induce a high degree of complexity and diversify any potentially linear response of tree population densities and treeline position to changing climatic conditions.
Mercurial Medicines
2022-03-14

Abstract Using ethnographic data, this article suggests that the therapeutic use of various mercury compounds in siddha medicine has so far not decreased despite international regulation of the substance and discussions surrounding the safety of mercury. Siddha practitioners portray mercury as central to their therapeutics. The article demonstrates this for different contexts, including the preparation of mercuric medicines; the production of mercury amulets; and recent research studies on mercury-based siddha drugs, targeting, for instance, dementia-related syndromes. Contextualizing siddha mercurial procedures and preparations through interlinking therapeutic, historical, and global frames underscores the fact that mercury use in siddha medicine today derives from alchemical traditions, but also transcends them. It is embedded in political contexts of science and healthcare in India, as it answers to concerns about safety and toxicity and at the same time takes center stage in negotiating siddha medical specialty and alterity vis-à-vis other medical practices, most notably ayurveda.