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Evaluation of prognostic biomarkers in meningiomas and their clinical implications in settings with limited resources
No full textBackground
The 5th edition of the World Health Organization (WHO) Central Nervous System (CNS) tumor classification for meningiomas acknowledges the clinical relevance of genomic profiling studies and emphasizes the importance of incorporating molecular information alongside histopathological features, leading to more accurate diagnoses and improved patient care.
Methods
We analyzed 206 meningioma samples (108 histological grade 1, 89 grade 2, and 9 grade 3) to study pTERT mutations, CDKN2A/B homozygous deletion, loss of H3K27me3, and p16 expression. The association of these molecular markers with survival outcomes was also assessed.
Results
pTERT mutation was found in 4.85% of cases, predominantly occurring in histological grade 2 (11.24%), while none of the histological grade 1 or 3 meningiomas exhibited this mutation. CDKN2A/B gene deletion was absent in grade 1 and detected in 2.24% of grade2, and 33.3% of histological grade 3 cases. There was a significant increase in loss of H3K27me3 with higher tumor grades, while p16 loss was observed in over 50% of cases across all histological grades. The presence of pTERT mutation and CDKN2A/B homozygous deletion resulted in the reclassification of 5.33% (11/206) of meningiomas as integrated grade 3. pTERT mutation and CDKN2A/B deletion, emerged as prognostically relevant markers, showing significant differences in progression-free survival (PFS) between integrated grade 3 and histological grade 2 meningiomas (P = .0002).
Conclusions
pTERT mutations are the most clinically relevant genetic alterations in meningiomas. Routine testing for pTERT mutations can identify high-risk cases of histologically grade 2 meningiomas, providing crucial prognostic information for treatment planning. CDKN2A/B alteration is rare and not cost-effective in assessing meningiomas. Immunohistochemical assessment of p16 and H3K27me3 expression lacks significant prognostic value. Assessment of pTERT mutations offers a cost-effective and valuable diagnostic tool for meningiomas
Forensic Elemental Analysis of Five Rupee and One Pound Coin with EDXRF Technique
No full textEnergy dispersive X-ray Fluorescence (EDXRF) technique using synchrotron radiation has been employed for elemental analysis of one pound and five rupees coins of two different countries- the UK and India. Total number of 12 coins - 4 one pound and 8 five rupees coin were analysed. A Peltier cooled Vortex solid state detector (SII Nano Technology, USA) having energy resolution of 138 eV at 5.96 keV X-rays was employed for the present analysis. A Peltier cooled Vortex solid state detector (SII Nano Technology, USA) having energy resolution of 138 eV at 5.96 keV X-rays was employed for the present analysis. The investigations were carried out to determine the similarities between the elemental composition and structure of coins. The major elements Cu, Ni, Fe, Cr and traces of two elements Mn and Mo were found during analysis. One of the elements i.e. Cu was found as primary major element in most of the coins. Two other elements Fe and Cr are also found as major element in 2 five rupees coins. Fe was generally considered as cheap metal composition in comparison to Cu. Besides these traces of Mo, S, Ca and Si were also observed whose compositional amount found very low (below 1%). The present study confirms the favorable economic conditions of two countries during their minting time. The XRF spectra and graphical representation of elemental concentration also helps to identify the similarities in structure and composition of coins. Results of present analysis of different types of coins are found in good agreement with standard composition and also with each other. The EDXRF analysis shows its effectiveness in forensic science without alteration of precious samples. Forensic analysis of such coins using Synchrotron radiation is very helpful in archeological study
The paradox of thermal vs. non-thermal effects in plasmonic photocatalysis
No full textThe debate surrounding the roles of thermal and non-thermal pathways in plasmonic catalysis has captured the attention of researchers and sparked vibrant discussions within the scientific community. In this review, we embark on a thorough exploration of this intriguing discourse, starting from fundamental principles and culminating in a detailed understanding of the divergent viewpoints. We probe into the core of the debate by elucidating the behavior of excited charge carriers in illuminated plasmonic nanostructures, which serves as the foundation for the two opposing schools of thought. We present the key arguments and evidence put forth by proponents of both the non-thermal and thermal pathways, providing a perspective on their respective positions. Beyond the theoretical divide, we discussed the evolving methodologies used to unravel these mechanisms. We discuss the use of Arrhenius equations and their variations, shedding light on the ensuing debates about their applicability. Our review emphasizes the significance of localized surface plasmon resonance (LSPR), investigating its role in collective charge oscillations and the decay dynamics that influence catalytic processes. We also talked about the nuances of activation energy, exploring its relationship with the nonlinearity of temperature and light intensity dependence on reaction rates. Additionally, we address the intricacies of catalyst surface temperature measurements and their implications in understanding light-triggered reaction dynamics. The review further discusses wavelength-dependent reaction rates, kinetic isotope effects, and competitive electron transfer reactions, offering an all-inclusive view of the field. This review not only maps the current landscape of plasmonic photocatalysis but also facilitates future explorations and innovations to unlock the full potential of plasmon-mediated catalysis, where synergistic approaches could lead to different vistas in chemical transformations
Experimental evolution induced by maternal post-copulatory factors in drosophila
No full textExperimental evolution is a powerful approach to study the mechanisms underlying the adaptation of selected characters under the conditions chosen in the laboratory. Drosophila melanogaster is a species frequently used to investigate the experimental evolution of characters, especially those related to reproduction. Recent intra-generational studies showed that cis-vaccenyl acetate (cVa), a sex pheromone transferred with bacteria on eggs by females either 1 day (D1) or 5 days (D5) after copulation, differentially affected the behavior and pheromone release in adult males emerging from these eggs. Here, we extended this finding to determine whether this alternative egg exposure repeated over many generations could affect a larger set of reproduction-related characters in both sexes. To test the repetitive effects of maternal D1 or D5 post-copulatory factors, we carried out an experimental selection procedure consisting of exposing eggs during 40 successive generations to D1 or D5 maternal post-copulatory factors. We compared cVa and cuticular pheromones, courtship and mating behaviors, and fecundity at different generations in flies of D1 and D5 lines. Based on findings obtained at earlier generations, we also determined survival, bacterial composition and gene expression in adults. Some of these complex traits significantly diverged between D1 and D5 lines indicating that maternal post-copulatory factors transmitted to eggs can influence adult life history traits
Divergence and convergence in epiphytic and endophytic phyllosphere bacterial communities of rice landraces
No full textPhyllosphere-associated microbes can significantly alter host plant fitness, with distinct functions provided by bacteria inhabiting the epiphytic (external surface) vs endophytic niches (internal leaf tissue). Hence, it is important to understand the assembly and stability of these phyllosphere communities, especially in field conditions. Broadly, epiphytic communities should encounter more environmental fluctuations and frequent immigration, whereas endophytic microbiota should face stronger host selection. As a result, we expect greater variability in epiphytic than endophytic communities. We analyzed the structure and stability of leaf phyllosphere microbiota of four traditionally cultivated rice landraces and one commercial variety from northeast India grown in the field for 3 consecutive years, supplemented with opportunistic sampling of eight other landraces. Epiphytic and endophytic bacterial communities shared dominant core genera such as Methylobacterium and Sphingomonas. Consistent with an overall strong environmental effect, both communities varied more across sampling years than across host landraces. Seeds sampled from a focal landrace did not support vertical transmission of phyllosphere bacteria, suggesting that both types of communities are assembled anew each generation. Despite these points of convergence, epiphytic communities had distinct composition and significantly higher microbial load and were more rich, diverse, modular, and unstable than endophytic communities. Finally, focused sampling of one landrace across developmental stages showed that the divergence between the two types of communities arose primarily at the flowering stage. Thus, our results show both convergent and divergent patterns of community assembly and composition in distinct phyllosphere niches in rice, identifying key bacterial genera and host developmental stages that may aid agricultural interventions to increase rice yield
Environment seen from infinite geodesics in Liouville Quantum Gravity
No full textFirst passage percolation (FPP) on Zd or Rd is a canonical model of a random metric space where the standard Euclidean geometry is distorted by random noise. Of central interest is the length and the geometry of the geodesic, the shortest path between points. Since the latter, owing to its length minimization, traverses through atypically low values of the underlying noise variables, it is an important problem to quantify the disparity between the environment rooted at a point on the geodesic and the typical one. We investigate this in the context of γ-Liouville quantum gravity (LQG) (where γ∈(0,2) is a parameter)—a random Riemannian surface induced on the complex plane by the random metric tensor e2γh/dγ,(dx2+dy2), where h is the whole plane, properly centered, Gaussian Free Field (GFF), and dγ is the associated dimension. We consider the unique infinite geodesic Γ from the origin, parametrized by the logarithm of its chemical length, and show that, for an almost sure realization of h, the distributions of the appropriately scaled field and the induced metric on a ball, rooted at a point “uniformly” sampled on Γ, converge to deterministic measures on the space of generalized functions and continuous metrics on the unit disk, respectively. Moreover, toward a better understanding of the limiting objects living on the unit disk, we show that they are singular with respect to their typical counterparts but become absolutely continuous away from the origin. Our arguments rely on unearthing a regeneration structure with fast decay of correlation in the geodesic owing to coalescence and the domain Markov property of the GFF. While there have been significant recent advances around this question for stochastic planar growth models in the Kardar–Parisi–Zhang universality class, the present work initiates this research program in the context of LQG
Plant defence mechanism in honeydew-mediated plant-Hemiptera-ant interactions and ecosystem sustainability: a review
No full textThe nature and outcome of various population interactions in an ecosystem significantly contribute to its stability. Any shift in frequency and abundance of such interactions including the density of the interacting species, can lead to cascading effects that may destabilize an otherwise balanced self-sustaining ecosystem. Inter-species interaction mediated by hemipteran honeydew is an example of mutualistic association that may provide indirect defence to the host plant. Such associations have been studied extensively due to their ubiquitous nature. Understanding these interactions from ecological and evolutionary perspectives is crucial for unravelling the complexities of mutualistic relationships in the context of communities and ecosystems, that might provide vital clues for sustainable ecosystem management. The plant–Hemiptera–ant association is impacted by several biotic and abiotic factors, varies in time and space, and exhibits context dependency as the outcome varies with environmental conditions where the interaction occurs. A comprehensive review of various dimensions of this complex association has not been attempted so far. Therefore, besides presenting an up-to-date status of research on this complex tripartite interaction among plants, Hemiptera, and ants, the present review examines the ecological costs and benefits for each interacting partner. The key milestones achieved in this emerging field of ecological research during the past five decades have been discussed with a network analysis of authors. The review also identifies a few research gaps, and suggests future research areas to gain deep insight into different dimensions of this association, which in turn might help developing effectivestrategies towards sustainable ecosystem management
Assessing the past and future dynamics of the Asian summer monsoon: Insights from palaeomonsoon synthesis and CMIP6 data
No full texthe Asian summer monsoon is one of the active synoptic scale weather phenomena, and has significant socioeconomic implications. A vast population relies on the associated precipitation, mostly dominating the agricultural practices of the region. Therefore, it is essential to assess past behavior to understand the present, including future projections. We used palaeomonsoon precipitation synthesis and Coupled Model Intercomparison Project Phase 6 (CMIP6) data to interactively show the dynamics and changes in the summer monsoon for the Asian region throughout the past millennium behavior to understand the present and future projections. In this study, we precisely analyzed and quantified the dynamics of summer precipitation variation throughout the last millennium (LM; 850–1849 CE) at an annual resolution, in which the major climatic events were the Medieval Warm Period (MWP; 900–1300 CE) and Little Ice Age (LIA; 1500–1850 CE). We also analyzed the historical or base climate (HC; 1850–2014 CE) and future monsoons (FM; 2015–2100 CE) using CMIP6 SSP2–4.5 and SSP5–8.5, to project the summer monsoon for Asia and the Indian subcontinent. The findings are encouraging, showing slightly increased precipitation during the MCA and low precipitation during the LIA in Asia. Moreover, the average summer monsoon daily rainfall remained 6.398 ± 0.634 and 6.310 ± 0.649 mm/d for the MCA and LIA, respectively, indicating a relatively slight variation in the summer monsoon precipitation during these climatic phases. In addition, for the twenty-first century, the CIMP6 projection shows increased summer monsoon precipitation over Asia, particularly in the northeast region. Further, the CMIP6 projections for SSP2–4.5 shows 6.457 ± 0.658 mm/d, and for SSP5–8.5 is 6.686 ± 0.837 mm/d for the twenty-first century. Furthermore, the results of Empirical Orthogonal Functions (EOFs) analysis suggest that the monsoon system may become more intense in some regions, whereas other regions may experience reduced precipitation in the Asia-Pacific region, with a regionally heterogeneous rise in heavy rainfall and high moisture throughout most of Asia. Orography, evaporation, moisture content, and circulation all affect the severity of precipitation in addition to fine-scale surface moisture feedback. The findings show that it is essential to consider both the past and the future to accurately estimate local and regional-scale susceptibility to climate change. Moreover, the synthesis of past data and analysis of future projections of the monsoon will provide a basis for reducing the unpredictability of future climate models
Projected energy and hydrological budgets over the Indus River Basin under a CORDEX-SA regional climate model framework
No full textThe Indus River is one of the largest transboundary rivers in Asia originating from Tibet autonomous region of China. This supplies water to the great plains of Punjab, significantly influencing agricultural productivity and shaping the socioeconomic conditions of the region's inhabitants. The present study investigates the potential impact of climate change on the water resources of the Indus River Basin (IRB). The study utilized the output from a regional climate model, REMO, to examine the projected change in energy and hydrological budget at 1.5, 2 specific warming levels and at the end of the century over IRB under three different representative concentration pathways (RCPs). The projected rise in the temperature from the historical period to the end of the century (both summer and winter) can be attributed to the increase in net downward energy flux compared to net upward energy flux. In the mid-century, the downward longwave radiation flux (sensible and latent heat flux) plays a dominant role in determining the surface energy balance during winter (summer). While, the combined impact of the energy components becomes more dominant at the end of the century for both seasons. Rainfall is projected to increase in the mountains of the upper Indus basin and gradually decline on the plains of the lower Indus basin till the end of the century. The projected decline in water storage over the plains of IRB can be attributed to the combination of declining rainfall and increasing evaporation. This will exert significant pressure on agriculture, industry and more importantly on the potable water supply. The IRB is found to be highly susceptible to climate extremes such as floods and drought. Climate change information is crucial for policy planners, governance, decision-makers, management authorities, etc. as it enables the implementation of better management practices, Additionally, it provides both short-term and long-term goals for a mitigation-based approach to reduce the impact of climate chang
Optimal site selection for the geomagnetic measurements at Hanle Observatory in Ladakh, India: Insights from magnetic campaign survey
No full textThe Himalayas are a region of geomagnetic importance, as they impact the geomagnetic field of Earth and space weather, as it is one of the largest mountain belts in the world. Due to its huge mass, it may influence the dynamics of the Earth’s core, the primary source of the geomagnetic field. In Indian longitudes, the mean location of the solar quiet (Sq) focus lies in latitudes closer to the Hanle region. Therefore, monitoring the magnetic field in the Hanle region is important. Ideally, a zero magnetic gradient or low magnetic gradient of the order of a few nT/m or less is preferred; this low gradient helps reduce the effects of local magnetic variations. Hence, to establish a continuous geomagnetic observation setup, a magnetic survey was conducted at Hanle, Ladakh, to identify the location of the low magnetic gradient. From the magnetic survey, the eastern part of the selected hillock was identified that has the least magnetic gradient. After checking other logistics, the chosen site is suitable for setting magnetic field observations. The proposed magnetic observatory at Hanle will be useful for studies related to unusual space weather phenomena, such as the citing of Auroras (of 22–23 April 2023 and 10–11 May 2024) in the Ladakh region, geomagnetic field monitoring in low-mid transitional regions, or magnetic exploration