Ten New Insights in Climate Science 2023/2024

Non-technical summary: We identify a set of essential recent advances in climate change research with high policy relevance, across natural and social sciences: (1) looming inevitability and implications of overshooting the 1.5°C warming limit, (2) urgent need for a rapid and managed fossil fuel phase-out, (3) challenges for scaling carbon dioxide removal, (4) uncertainties regarding the future contribution of natural carbon sinks, (5) intertwinedness of the crises of biodiversity loss and climate change, (6) compound events, (7) mountain glacier loss, (8) human immobility in the face of climate risks, (9) adaptation justice, and (10) just transitions in food systems. Technical summary The IPCC Assessment Reports offer the scientific foundation for international climate negotiations and constitute an unmatched resource for climate change researchers. However, the assessment cycles take multiple years. As a contribution to cross- and interdisciplinary understanding across diverse climate change research communities, we have streamlined an annual process to identify and synthesise essential research advances. We collected input from experts on different fields using an online questionnaire and prioritised a set of ten key research insights with high policy relevance. This year we focus on: (1) looming overshoot of the 1.5°C warming limit, (2) urgency of phasing-out fossil fuels, (3) challenges for scaling carbon dioxide removal, (4) uncertainties regarding the future of natural carbon sinks, (5) need for join governance of biodiversity loss and climate change, (6) advances in the science of compound events, (7) mountain glacier loss, (8) human immobility in the face of climate risks, (9) adaptation justice, and (10) just transitions in food systems. We first present a succinct account of these Insights, reflect on their policy implications, and offer an integrated set of policy relevant messages. This science synthesis and science communication effort is also the basis for a report targeted to policymakers as a contribution to elevate climate science every year, in time for the UNFCCC COP. Social media summary We highlight recent and policy-relevant advances in climate change research - with input from more than 200 experts 1. © 2023 Cambridge University Press. All rights reserved. There are 78 total authors to this piece. We have listed the first twelve. The available download is the accepted manuscript

Genome-wide association study for type 2 diabetes in Indians identifies a new susceptibility locus at 2q21.

Indians undergoing socioeconomic and lifestyle transitions will be maximally affected by epidemic of type 2 diabetes (T2D). We conducted a two-stage genome-wide association study of T2D in 12,535 Indians, a less explored but high-risk group. We identified a new type 2 diabetes-associated locus at 2q21, with the lead signal being rs6723108 (odds ratio 1.31; P = 3.32 × 10⁻⁹). Imputation analysis refined the signal to rs998451 (odds ratio 1.56; P = 6.3 × 10⁻¹²) within TMEM163 that encodes a probable vesicular transporter in nerve terminals. TMEM163 variants also showed association with decreased fasting plasma insulin and homeostatic model assessment of insulin resistance, indicating a plausible effect through impaired insulin secretion. The 2q21 region also harbors RAB3GAP1 and ACMSD; those are involved in neurologic disorders. Forty-nine of 56 previously reported signals showed consistency in direction with similar effect sizes in Indians and previous studies, and 25 of them were also associated (P < 0.05). Known loci and the newly identified 2q21 locus altogether explained 7.65% variance in the risk of T2D in Indians. Our study suggests that common susceptibility variants for T2D are largely the same across populations, but also reveals a population-specific locus and provides further insights into genetic architecture and etiology of T2D

Common variants in CLDN2 and MORC4 genes confer disease susceptibility in patients with chronic pancreatitis

A recent Genome-wide Association Study (GWAS) identified association with variants in X-linked CLDN2 and MORC4 and PRSS1-PRSS2 loci with Chronic Pancreatitis (CP) in North American patients of European ancestry. We selected 9 variants from the reported GWAS and replicated the association with CP in Indian patients by genotyping 1807 unrelated Indians of Indo-European ethnicity, including 519 patients with CP and 1288 controls. The etiology of CP was idiopathic in 83.62% and alcoholic in 16.38% of 519 patients. Our study confirmed a significant association of 2 variants in CLDN2 gene (rs4409525—OR 1.71, P = 1.38 x 10-09; rs12008279—OR 1.56, P = 1.53 x 10-04) and 2 variants in MORC4 gene (rs12688220—OR 1.72, P = 9.20 x 10-09; rs6622126—OR 1.75, P = 4.04x10-05) in Indian patients with CP. We also found significant association at PRSS1-PRSS2 locus (OR 0.60; P = 9.92 x 10-06) and SAMD12-TNFRSF11B (OR 0.49, 95% CI [0.31–0.78], P = 0.0027). A variant in the gene MORC4 (rs12688220) showed significant interaction with alcohol (OR for homozygous and heterozygous risk allele -14.62 and 1.51 respectively, P = 0.0068) suggesting gene-environment interaction. A combined analysis of the genes CLDN2 and MORC4 based on an effective risk allele score revealed a higher percentage of individuals homozygous for the risk allele in CP cases with 5.09 fold enhanced risk in individuals with 7 or more effective risk alleles compared with individuals with 3 or less risk alleles (P = 1.88 x 10-14). Genetic variants in CLDN2 and MORC4 genes were associated with CP in Indian patients

Measurement of Benzo(a)pyrene in PM10 Collected in New Delhi

Polyaromatic hydrocarbons (PAH) are the compound which consists of multiple benzene rings bonded in straight, groups or angular forms. They are also found in atmospheric aerosols. In the atmosphere, they can be emitted primarily as a result of incomplete combustion of natural sources (fossil fuels, forest fires, smoke etc.) or anthropogenic sources (coal burning, vehicular emissions, smoke, etc.) or secondarily by atmospheric processes. Depending on the anthropogenic sources, PAHs may occur in significant concentration in urban and industrial ambient air, i.e., bounded with particulate matter (PM). A particle whose aerodynamic diameter is <= 10 mu m is called PM10. Benzo(a)pyrene (BaP) is among the most toxic and carcinogenic PAHs. Both PM10 and BaP are among the 12 criteria pollutants listed in Indian National Ambient Air Quality Standards (NAAQS). In this paper, BaP concentration in PM10 collected in a representative site of New Delhi was studied during the year 2014-2015. The average concentration of BaP is varied from 0.04 to 25.7 ng m(-3). The uncertainty components in measurements were also estimated along with statistical analysis. The most significant uncertainty component is the purity of the BaP standard which has the highest uncertainty contribution as 77%

Low rank and sparsity constrained method for identifying overlapping functional brain networks.

Analysis of functional magnetic resonance imaging (fMRI) data has revealed that brain regions can be grouped into functional brain networks (fBNs) or communities. A community in fMRI analysis signifies a group of brain regions coupled functionally with one another. In neuroimaging, functional connectivity (FC) measure can be utilized to quantify such functionally connected regions for disease diagnosis and hence, signifies the need of devising novel FC estimation methods. In this paper, we propose a novel method of learning FC by constraining its rank and the sum of non-zero coefficients. The underlying idea is that fBNs are sparse and can be embedded in a relatively lower dimension space. In addition, we propose to extract overlapping networks. In many instances, communities are characterized as combinations of disjoint brain regions, although recent studies indicate that brain regions may participate in more than one community. In this paper, large-scale overlapping fBNs are identified on resting state fMRI data by employing non-negative matrix factorization. Our findings support the existence of overlapping brain networks

GLACIOLOGY AN INTERESTING AND ADVENTUROUS CAREER

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Langerhans cell histiocytosis: An enigmatic disease

Abstract Background: Langerhans cell histiocytosis (LCH) is a poorly understood disease with heterogeneous clinical presentation ranging from unifocal bony involvement to disseminated disease with life-threatening complications. Materials and Methods: The clinical profile, laboratory findings, treatment, and long-term outcome were retrieved from maintained medical records from January 2006 to January 2016 and were retrospectively analyzed. The extent of the disease was classified as per the LCH-III trial of “The Histiocyte Society.” The assessment and categorization of treatment response followed LCH III trial definitions. Results: A total of 28 children with LCH were diagnosed. The age ranged between 5 months and 9 years, with a mean of 3½ years. The M: F ratio was 3:1. Single system, unifocal and multifocal bone diseases were seen in nine (32.1%) and two (7.1%) cases, respectively. Disseminated disease without risk organ involvement was seen in six (21.1%), whereas disseminated disease with risk organ involvement was seen in 11 (39.3%) cases. The most common presentation was bony involvement (19 [67.8%]), out of which 16 (88.8%) had skull involvement. During follow-up, 17 (60.7%) were in complete remission though five (17.8%) of them relapsed, but achieved second remission. Two (7.1%) were lost to follow-up. Six (21.4%) had progressive disease of which four expired and two abandoned treatment. Two (10.7%) refused the initiation of treatment. Conclusion: A better understanding of the disease, early suspicion, and diagnosis can improve the outcome of patients with LCH

Adaptation to climate change induced water stress in major glacierized mountain regions

Mountains are a critical source of water. Cryospheric and hydrological changes in combination with socio-economic development are threatening downstream water security triggering the need for effective adaptation responses. Here, we present a global systematic review (83 peer-reviewed articles) that assesses different water-related stressors and the adaptation responses to manage water stress in major glaciated mountain regions. Globally, agriculture (42%), tourism (12%), hydropower (8%) and health and safety (4%) are among the main sectors affected by hydrological and cryospheric changes . A broad set of adaptation measures has already been implemented in the world’s mountain regions. We find that globally the most commonly used adaptation practices correspond to the improvement of water storage infrastructure (13%), green infrastructure (9.5%), agricultural practices (17%), water governance and policies (21%), disaster risk reduction (9.5%) and economic diversification (10%). Successful implementation of adaptation measures is limited by reduced stakeholder capacities, collaboration and financial resources, and policies and development. To overcome these limitations, funding for climate change adaptation and development programmes in mountains and trust-building measures such as shared stakeholder activities need to be strengthened. Local awareness raising of both, the adverse effects of climate change and potentially positive implications of specific adaptation measures can help to support successful adaptation