ABSTRACT
A new window to observing individual stars and other small sources at cosmological distances was opened recently, with the detection of several caustic-crossing events in galaxy cluster ...fields. Many more such events are expected soon from dedicated campaigns with the Hubble Space Telescope and the James Webb Space Telescope. These events can not only teach us about the lensed sources themselves, such as individual high-redshift stars, star clusters, or accretion discs, but through their light curves they also hold information about the point-mass function of the lens, and thus, potentially, the composition of dark matter. We present here a simple method for simulating light curves of such events, i.e. the change in apparent magnitude of the source as it sweeps over the net of caustics generated by microlenses embedded around the critical region of the lens. The method is recursive and so any reasonably sized small source can be accommodated, down to sub-solar scales, in principle. We compare the method, which we dub Adaptive Boundary Method, with other common methods such as simple inverse ray shooting, and demonstrate that it is significantly more efficient and accurate in the small-source and high-magnification regime of interest. A python version of the code is made publicly available in an open-source fashion for simulating future events.
ABSTRACT
We discuss the gravitational lensing of gravitational wave (GW) signals from coalescing binaries. We delineate the regime where wave effects are significant from the regime where geometric ...limit can be used. Further, we focus on the effect of microlensing and the combined effect of strong lensing and microlensing. We find that microlensing combined with strong lensing can introduce time varying phase shift in the signal and hence can lead to detectable differences in the signal observed for different images produced by strong lensing. This, coupled with the coarse localization of signal source in the sky for GW detections, can make it difficult to identify the common origin of signal corresponding to different images and use observables like time delay. In case we can reliably identify corresponding images, microlensing of individual images can be used as a tool to constrain properties of microlenses. Sources of gravitational waves can undergo microlensing due to lenses in the disc/halo of the Galaxy, or due to lenses in an intervening galaxy even in absence of strong lensing. In general the probability for this is small with one exception: extragalactic sources of GWs that lie in the galactic plane are highly likely to be microlensed. Wave effects are extremely important for such cases. In case of detections of such sources with low signal-to-noise ratio, the uncertainty of occurrence of microlensing or otherwise introduces an additional uncertainty in the parameters of the source.
ABSTRACT
With increasing sensitivities of the current ground-based gravitational wave (GW) detectors, the prospects of detecting a strongly lensed GW signal are going to be high in the coming years. ...When such a signal passes through an intervening lensing galaxy or galaxy cluster, the embedded stellar mass microlenses lead to interference patterns in the signal that may leave observable signatures. In this work, we present an extensive study of these wave effects in the Laser Interferometer Gravitational Wave Observatory/Virgo frequency band (10–104 Hz) due to the presence of the microlens population in galaxy scale lenses for the first time. We consider a wide range of strong lensing (macro) magnifications and the corresponding surface microlens densities found in lensing galaxies and use them to generate realizations of the amplification factor. The methodologies for simulating amplification curves for both types of images (minima and saddle points) are also discussed. We then study how microlensing is broadly affected by the parameters like macro-magnifications, stellar densities, the initial mass function, types of images, and microlens distribution around the source. In general, with increasing macro-magnification values, the effects of microlensing become increasingly significant regardless of other parameters. Mismatch analysis between the lensed and the unlensed GW waveforms from chirping binaries suggests that, while inferring the source parameters, microlensing cannot be neglected for macro-magnification ≳15. Furthermore, for extremely high macro-magnifications ≳100, the mismatch can even exceed $5{{\ \rm per\ cent}}$, which can result in both a missed detection and, consequently, a missed lensed signal.
ABSTRACT This work studies microlensing effects in strongly lensed gravitational wave (GW) signals corresponding to global minima images in galaxy-scale lenses. We find that stellar microlenses alone ...are unable to introduce noticeable wave effects in the global minima GW signals at strong lensing magnification $( {\mu})\lt 50$ with match value between unlensed and lensed GW signals being above ${\sim }99.5~{{\ \rm per \, cent}}$ in ${\sim }90~{{\ \rm per \, cent}}$ of systems implying that GW signals corresponding to global minima can be treated as reference signal to determine the amount of microlensing in other strongly lensed counterparts. Since the stellar microlenses introduce negligible wave effects in global minima, they can be used to probe the intermediate-mass black hole (IMBH) lenses in the galaxy lens. We show that the presence of an IMBH lens with mass in the range $50,10^3~{\rm M_\odot }$ such that the global minima lies within five Einstein radius of it, the microlensing effects at $f\lt 10^2$ Hz are mainly determined by the IMBH lens for ${\mu} \lt 50$. Assuming that a typical strong lensing magnification of 3.8 and high enough signal-to-noise ratio (in the range ${\simeq }10, 30$) to detect the microlensing effect in GW signals corresponding to global minima, with non-detection of IMBH-led microlensing effects in ${\simeq }15~({\simeq }150)$ lensed GW signals, we can rule out dark matter fraction $\gt 10~{{\ \rm per \, cent}}~(\gt 1~{{\ \rm per \, cent}})$ made of IMBH population inside galaxy lenses with mass values $\gt 150~{\rm M_\odot }$ with ${\sim }$90 per cent confidence. Although we have specifically used IMBHs as an example, the same analysis applies to any subhalo (or compact objects) with lensing masses (i.e. the total mass inside Einstein radius) satisfying the above criterion.
The oral cavity of human contains bacteria that are critical for maintaining the homeostasis of the body. External stressors such as high altitude (HA) and low oxygen affect the human gut, skin and ...oral microbiome. However, compared to the human gut and skin microbiome, studies demonstrating the impact of altitude on human oral microbiota are currently scarce. Alterations in the oral microbiome have been reported to be associated with various periodontal diseases. In light of the increased occurrence of HA oral health related problems, the effect of HA on the oral salivary microbiome was investigated. We conducted a pilot study in 16 male subjects at two different heights i.e., H1 (210 m) and H2 (4420 m). Total of 31 saliva samples,16 at H1 and 15 at H2 were analyzed by utilizing the 16S rRNA high-throughput sequencing, to explore the relationship between the HA environment and salivary microbiota. The preliminary results suggesting that, the most abundant microbiome at the phylum level are: Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria. Interestingly, 11 genera were identified at the both heights with different relative abundances. In addition, the salivary microbiome was more diverse at H1 compared to H2 as demonstrated by decreased alpha diversity. Further, predicted functional results indicate that microbial metabolic profiles significantly decreased at H2 as compared to H1, including two major metabolic pathways involving carbohydrates, and amino acids. Our findings show that HA induces shifts in the composition and structure of human oral microbiota which can affect host health homeostasis.
Abstract
We study the spatially resolved stellar populations of 444 galaxies at 0.3 <
z
< 6.0 in two clusters (WHL 0137–08 and MACS 0647+70) and a blank field, combining imaging data from the Hubble ...Space Telescope and JWST to perform spatially resolved spectral energy distribution (SED) modeling using
piXedfit
. The high spatial resolution of the imaging data combined with magnification from gravitational lensing in the cluster fields allows us to resolve a large fraction of our galaxies (109) to subkiloparsec scales. At redshifts around cosmic noon and higher (2.5 ≲
z
≲ 6.0), we find mass-doubling times to be independent of radius, inferred from flat specific star formation rate (sSFR) radial profiles and similarities between the half-mass and half-SFR radii. At lower redshifts (1.5 ≲
z
≲ 2.5), a significant fraction of our star-forming galaxies shows evidence for nuclear starbursts, inferred from a centrally elevated sSFR and a much smaller half-SFR radius compared to the half-mass radius. At later epochs, we find more galaxies suppress star formation in their centers but are still actively forming stars in the disk. Overall, these trends point toward a picture of inside-out galaxy growth consistent with theoretical models and simulations. We also observe a tight relationship between the central mass surface density and global stellar mass with ∼0.38 dex scatter. Our analysis demonstrates the potential of spatially resolved SED analysis with JWST data. Future analysis with larger samples will be able to further explore the assembly of galaxy mass and the growth of their structures.
Sapindus emarginatus Vahl (Sapindaceae) also known as 'Indian Soap nut' is significantly important for saponin content in its fruits. However, its current population in India is heavily fragmented ...due to a lack of sustainable harvesting practices. Moreover, changing climatic regimes may further limit its distribution and possibly compromise the survival of the species in nature. The aim of the present study was to: predict the future distribution range of S. emarginatus; identify the bioclimatic variables limiting this distribution and to evaluate its adaptive fitness and genomic resilience towards these variables. To determine future species distribution range and identify limiting bioclimatic variables, we applied two different ecological niche models (ENMs; BioClim and MaxEnt) on real occurrence data (n = 88 locations). The adaptive fitness of the species was evaluated by quantifying the genetic variability with AFLP markers and marker-environmental associations, using AFLP-associated Bayesian statistics. We found 77% overlap between the baseline (2030) and predicted (2100) species distribution ranges, which were primarily determined by maximum temperature (T
) and mean annual precipitation (MAP). The T
and MAP contributed 43.1% and 27.1%, respectively to ENM model prediction. Furthermore, AFLP loci significantly associated with bioclimatic variables, and T
and MAP represent the lowest proportion (6.15%), confirming to the severe response of the species genome towards these variables. Nevertheless, the very low Linkage disequilibrium (LD) in these loci (4.54%) suggests that the current sensitivity to T
and MAP is subject to change during recombination. Moreover, a combination of high heterozygosity (0.40-0.43) and high within-population variability (91.63 ± 0.31%) confirmed high adaptive fitness to maintain reproductive success. Therefore, the current populations of S. emarginatus have substantial genomic resilience towards future climate change, albeit significant conservation efforts (including mass multiplication) are warranted to avoid future deleterious impacts of inbreeding depression on the fragmented populations.
Background: Laryngoscopy and endotracheal intubation have been associated with marked hemodynamic responses and hazards. This study was undertaken with the purpose to compare the intubating ...conditions when the suitable time for intubation was judged by either clinical assessment or train-of-four monitoring.
Methods: 60 patients without any difficult airway predictors, posted for surgery under general anaesthesia, were randomised into two groups. In Group A patients, the trachea was intubated after train of four counts became zero in adductor pollicis muscle, whereas in Group B patients, intubation was done after clinically judging jaw muscle relaxation. The primary objective was to compare Intubating conditions and mean duration of time between the administration of a neuromuscular blocker and endotracheal intubation. The secondary objectives included number of attempts, changes in hemodynamic parameters. Results were analysed by the Analysis of variance and chi-square tests.
Results: In all Group A patients excellent and good intubating conditions were observed, whereas 25 out of 30 patients (83%) in Group B showed excellent and good intubation conditions. The mean time required for intubation was significantly longer in Group A compared to Group B (369 ± 79 s vs. 191 ± 5 s). HR and mean arterial pressure were significantly higher in Group B as compared to Group A after laryngoscopy and tracheal intubation (P < 0.05).
Conclusion: Better intubating conditions and more haemodynamic stability are seen after attaining complete relaxation of laryngeal muscles, as detected by neuromuscular monitoring of adductor pollicis muscle.
Reverse osmosis (RO) is known for the economic dewatering of dairy streams without any change in phase. At the household level, surplus milk is fermented and churned to obtain butter, which is ...subsequently heated to obtain clarified milk fat (ghee). The production of 1 kg ghee generates 15–20 kg sour buttermilk (SBM) as a by-product that is mostly drained. This causes a loss of milk solids and environmental pollution. The processing, preservation and valorization of SBM are quite challenging because of its low total solids (TS) and pH, poor heat stability and limited shelf life. This investigation aimed to transform SBM into a novel dried dairy ingredient. SBM was thermized, filtered, defatted and concentrated at 35 ± 1 °C, employing RO up to 3.62× (12.86%). The RO concentrate was subsequently converted into sour buttermilk powder (SBMP) by employing spray drying. SBMP was further characterized for its physicochemical, reconstitution and functional properties; rheological and morphological characteristics; and amino acid and fatty acid profiling, along with FTIR and XRD spectra. SBMP was “instant soluble-3 s” and exhibited excellent emulsion stability (80.70%), water binding capacity (4.34 g/g of protein), flowability (28.36°) and antioxidant properties. In nutshell, a process was developed for the valorization of sour buttermilk to a novel dairy ingredient by employing reverse osmosis and a spray-drying process.
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