Unveiling the Limits of Learned Local Search Heuristics: Are You the Mightiest of the Meek?

In recent years, combining neural networks with local search heuristics has become popular in the field of combinatorial optimization. Despite its considerable computational demands, this approach has exhibited promising outcomes with minimal manual engineering. However, we have identified three critical limitations in the empirical evaluation of these integration attempts. Firstly, instances with moderate complexity and weak baselines pose a challenge in accurately evaluating the effectiveness of learning-based approaches. Secondly, the absence of an ablation study makes it difficult to quantify and attribute improvements accurately to the deep learning architecture. Lastly, the generalization of learned heuristics across diverse distributions remains underexplored. In this study, we conduct a comprehensive investigation into these identified limitations. Surprisingly, we demonstrate that a simple learned heuristic based on Tabu Search surpasses state-of-the-art (SOTA) learned heuristics in terms of performance and generalizability. Our findings challenge prevailing assumptions and open up exciting avenues for future research and innovation in combinatorial optimization

AstroSat observation of rapid Type-I thermonuclear burst from the low mass X-ray binary GX 3+1

We report the results of an observation of low mass X-ray binary GX 3+1 with {\it AstroSat}'s Large Area X-ray Proportional Counter (LAXPC) and Soft X-ray Telescope (SXT) instruments on-board for the first time. We have detected one Type-1 thermonuclear burst ($\sim$ 15 s) present in the LAXPC 20 light curve, with a double peak feature at higher energies and our study of the hardness-intensity diagram reveals that the source was in a soft banana state. The pre-burst emission could be described well by a thermally Comptonised model component. The burst spectra is modelled adopting a time-resolved spectroscopic method using a single color blackbody model added to the pre-burst model, to monitor the parametric changes as the burst decays. Based on our time-resolved spectroscopy, we claim that the detected burst is a photospheric radius expansion (PRE) burst. During the PRE phase, the blackbody flux is found to be approximately constant at an averaged value $\sim$ 2.56 in $10^{-8}$ ergs s$^{-1}$ cm$^{-2}$ units. On the basis of literature survey, we infer that \textit{AstroSat}/LAXPC 20 has detected a burst from GX 3+1 after more than a decade which is also a PRE one. Utilising the burst parameters obtained, we provide a new estimation to the source distance, which is $\sim$ 9.3 $\pm$ 0.4 kpc, calculated for an isotropic burst emission. Finally, we discuss and compare our findings with the published literature reports.Comment: 14 pages, 10 figures, accepted for publication in The Journal of Astrophysics and Astronom

Non-zero θ13\theta_{13}, CP-violation and Neutrinoless Double Beta Decay for Neutrino Mixing in the A4×Z2×Z2′A_4\times Z_2\times Z_2^\prime Flavor Symmetry Model

We study the modification of the Altarelli-Feruglio $A_4$ flavor symmetry model by adding three singlet flavons $\xi'$, $\xi''$ and $\rho$ and the model is augmented with extra $Z_2\times Z_2^ \prime$ symmetry to prevent the unwanted terms in our study. The addition of these three flavons lead to two higher order corrections in the form of two perturbation parameters $\epsilon$ and $\epsilon^\prime$. These corrections yield the deviation from exact tri-bimaximal (TBM) neutrino mixing pattern by producing a non-zero $\theta_{13}$ and other neutrino oscillation parameters which are consistent with the latest experimental data. In both the corrections, the neutrino masses are generated via Weinberg operator. The analysis of the perturbation parameters $\epsilon$ and $\epsilon^\prime$, shows that normal hierarchy (NH) and inverted hierarchy (IH) for $\epsilon$ does not change much. However, as the values of $\epsilon^\prime$ increases, $\theta_{23}$ occupies the lower octant for NH case. We further investigate the neutrinoless double beta decay parmeter $m_{\beta\beta}$ using the parameter space of the model for both normal and inverted hierarchies of neutrino masses.Comment: 19 pages, 6 figures, 3 table

Genome-wide Analysis of the Host Intracellular Network that Regulates Survival of Mycobacterium tuberculosis

SummaryWe performed a genome-wide siRNA screen to identify host factors that regulated pathogen load in human macrophages infected with a virulent strain of Mycobacterium tuberculosis. Iterative rounds of confirmation, followed by validation, identified 275 such molecules that were all found to functionally associate with each other through a dense network of interactions. This network then yielded to a molecular description of the host cell functional modules that were both engaged and perturbed by the pathogen. Importantly, a subscreen against a panel of field isolates revealed that the molecular composition of the host interface varied with both genotype and the phenotypic properties of the pathogen. An analysis of these differences, however, permitted identification of those host factors that were invariantly involved, regardless of the diversification in adaptive mechanisms employed by the pathogen. Interestingly, these factors were found to predominantly function through the regulation of autophagy

Fabrication, Characterization and Assessment of Polymeric Nanoparticles as a Nanomedicine Approach for Paclitaxel Delivery for Enhanced Cancer Treatment

The effectiveness of paclitaxel as a cancer treatment is widely recognized. However, its solubility issue can be addressed by blending it with ethanol and Cremophor EL, a product marketed under the trade name Taxol. Nevertheless, to enhance the anticancer efficacy of Cremophor EL and reduce adverse effects, alternative delivery methods and strategies must be explored. The objective of this work was to synthesize PLGA nanoparticles (PNF) loaded with paclitaxel and evaluate a number of characteristics, including in vitro drug release, drug loading, polydispersity index, zeta potential, and particle size. Finding the best formulation, PNF4, based on its in vitro drug release properties, was the main goal of the study. The surface morphology of PNF4 was then investigated by means of scanning and transmission electron microscopy after that (SEM and TEM). The delivery method follows the Korsmeyer-Peppas model, according to analysis of the in vitro drug release kinetics, indicating a "Fickian diffusion" mechanism. Furthermore, the in vitro cytotoxicity assessment demonstrated that the PNF4 formulation exhibited superior cytotoxicity compared to free paclitaxel

Revealing nature of GRB 210205A, ZTF21aaeyldq (AT2021any), and follow-up observations with the 4K×\times4K CCD Imager+3.6m DOT

Optical follow-up observations of optical afterglows of gamma-ray bursts are crucial to probe the geometry of outflows, emission mechanisms, energetics, and burst environments. We performed the follow-up observations of GRB 210205A and ZTF21aaeyldq (AT2021any) using the 3.6m Devasthal Optical Telescope (DOT) around one day after the burst to deeper limits due to the longitudinal advantage of the place. This paper presents our analysis of the two objects using data from other collaborative facilities, i.e., 2.2m Calar Alto Astronomical Observatory (CAHA) and other archival data. Our analysis suggests that GRB 210205A is a potential dark burst once compared with the X-ray afterglow data. Also, comparing results with other known and well-studied dark GRBs samples indicate that the reason for the optical darkness of GRB 210205A could either be intrinsic faintness or a high redshift event. Based on our analysis, we also found that ZTF21aaeyldq is the third known orphan afterglow with a measured redshift except for ZTF20aajnksq (AT2020blt) and ZTF19abvizsw (AT2019pim). The multiwavelength afterglow modelling of ZTF21aaeyldq using the afterglowpy package demands a forward shock model for an ISM-like ambient medium with a rather wider jet opening angle. We determine circumburst density of $n_{0}$ = 0.87 cm$^{-3}$, kinetic energy $E_{k}$ = 3.80 $\times 10^{52}$ erg and the afterglow modelling also indicates that ZTF21aaeyldq is observed on-axis ($\theta_{obs} < \theta_{core}$) and a gamma-ray counterpart was missed by GRBs satellites. Our results emphasize that the 3.6m DOT has a unique capability for deep follow-up observations of similar and other new transients for deeper observations as a part of time-domain astronomy in the future.Comment: Accepted for Special Issue of Journal of Astrophysics and Astronomy, 2022, Astrophysical jets and observational facilities: National perspective, 05 -09 April 2021, ARIES Nainita

Effect of fermented bamboo shoot on the quality and shelf life of nuggets prepared from desi spent hen

Aim: An investigation was carried out to prepare nuggets from the relatively tough and fibrous meat of desi spent hen using fermented bamboo shoot as a phytopreservative in order to enhance the physico-chemical, microbiological and keeping quality of the nuggets. Materials and Methods: Lean meat of desi spent hen was minced and blended along with other non-meat ingredients and fermented bamboo shoot @10%. The emulsion was filled in metallic moulds and steam cooked and cut into pieces. Ready-toeat nuggets thus prepared were packed in sterilized LDPE zip bags and stored at 4&#177;1&#176;C up-to 15 days for quality evaluation. Emulsion stability (%), cooking yield (%), a and proximate composition were studied on the day of preparation, while estimation of pH, TBA values, microbial load and sensory evaluation were carried out at 5 days interval and up-to 15th day of storage. Results: The emulsion stability (%), cooking yield (%), moisture (%), crude protein (%) and total ash (%) of FBS treated nuggets differed significantly (p<0.01) from the control products. Storage studies revealed significantly lower (p<0.01) pH, TBA value, total plate count, psychrophillic count and counts for yeast and moulds in FBS treated nuggets in comparison to control products. Both control and treated nuggets exhibited gradual loss of panel ratings during the storage period (4&#177;1&#176;C for 15 days), however, nuggets containing fermented bamboo shoot revealed significantly higher (p<0.01) mean sensory scores in terms of flavour, texture, juiciness and overall acceptability. Conclusion: Nuggets with better physico-chemical and shelf life can be prepared with incorporation of fermented bamboo shoot @10% (w/w) to the nugget emulsion. [Vet World 2013; 6(7.000): 419-423