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Prediction and validation of mouse meiosis-essential genes based on spermatogenesis proteome dynamics [Research]

The molecular mechanism associated with mammalian meiosis has yet to be fully explored, and one of the main reasons for this lack of exploration is that some meiosis-essential genes are still unknown. The profiling of gene expression during spermatogenesis has been performed in previous studies, yet few studies have aimed to find new functional genes. Since there is a huge gap between the number of genes that are able to be quantified and the number of genes that can be characterized by phenotype screening in one assay, an efficient method to rank quantified genes according to phenotypic relevance is of great importance. We proposed to rank genes by the probability of their function in mammalian meiosis based on global protein abundance using machine learning. Here, nine types of germ cells focusing on continual substages of meiosis prophase I were isolated, and the corresponding proteomes were quantified by high-resolution mass spectrometry. By combining meiotic labels annotated from the MGI mouse knockout database and the spermatogenesis proteomics dataset, a supervised machine learning package, FuncProFinder, was developed to rank meiosis-essential candidates. Of the candidates whose functions were unannotated, four of ten genes with the top prediction scores, Zcwpw1, Tesmin, 1700102P08Rik and Kctd19, were validated as meiosis-essential genes by knockout mouse models. Therefore,  mammalian meiosis-essential genes could be efficiently predicted based on the protein abundance dataset, which provides a paradigm for other functional gene mining from a related abundance dataset.




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Proteomic analyses identify differentially expressed proteins and pathways between low-risk and high-risk subtypes of early-stage lung adenocarcinoma and their prognostic impacts [Research]

The histopathological subtype of lung adenocarcinoma (LUAD) is closely associated with prognosis. Micropapillary or solid predominant LUAD tends to relapse after surgery at an early stage, whereas lepidic pattern shows a favorable outcome. However, the molecular mechanism underlying this phenomenon remains unknown. Here, we recruited 31 lepidic predominant LUADs (LR: low-risk subtype group) and 28 micropapillary or solid predominant LUADs (HR: high-risk subtype group). Tissues of these cases were obtained and label-free quantitative proteomic and bioinformatic analyses were performed. Additionally, prognostic impact of targeted proteins was validated using The Cancer Genome Atlas databases (n=492) and tissue microarrays composed of early-stage LUADs (n=228). A total of 192 differentially expressed proteins were identified between tumor tissues of LR and HR and three clusters were identified via hierarchical clustering excluding eight proteins. Cluster 1 (65 proteins) showed a sequential decrease in expression from normal tissues to tumor tissues of LR and then to HR and was predominantly enriched in pathways such as tyrosine metabolism and ECM-receptor interaction, and increased matched mRNA expression of 18 proteins from this cluster predicted favorable prognosis. Cluster 2 (70 proteins) demonstrated a sequential increase in expression from normal tissues to tumor tissues of LR and then to HR and was mainly enriched in pathways such as extracellular organization, DNA replication and cell cycle, and high matched mRNA expression of 25 proteins indicated poor prognosis. Cluster 3 (49 proteins) showed high expression only in LR, with high matched mRNA expression of 20 proteins in this cluster indicating favorable prognosis. Furthermore, high expression of ERO1A and FEN1 at protein level predicted poor prognosis in early-stage LUAD, supporting the mRNA results. In conclusion, we discovered key differentially expressed proteins and pathways between low-risk and high-risk subtypes of early-stage LUAD. Some of these proteins could serve as potential biomarkers in prognostic evaluation.




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A proteomic approach to understand the clinical significance of acute myeloid leukemia-derived extracellular vesicles reflecting essential characteristics of leukemia [Research]

Extracellular vesicle (EV) proteins from acute myeloid leukemia (AML) cell lines were analyzed using mass spectrometry. The analyses identified 2450 proteins, including 461 differentially expressed proteins (290 upregulated and 171 downregulated). CD53 and CD47 were upregulated and were selected as candidate biomarkers. The association between survival of patients with AML and the expression levels of CD53 and CD47 at diagnosis was analyzed using mRNA expression data from The Cancer Genome Atlas database. Patients with higher expression levels showed significantly inferior survival than those with lower expression levels. Enzyme-linked immunosorbent assay results of the expression levels of CD53 and CD47 from EVs in the bone marrow of patients with AML at diagnosis and at the time of complete remission with induction chemotherapy revealed that patients with downregulated CD53 and CD47 expression appeared to relapse less frequently. Network model analysis of EV proteins revealed several upregulated kinases, including LYN, CSNK2A1, SYK, CSK, and PTK2B. The potential cytotoxicity of several clinically applicable drugs that inhibit these kinases was tested in AML cell lines. The drugs lowered the viability of AML cells. The collective data suggest that AML-derived EVs could reflect essential leukemia biology.




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A potential role for the Gsdf-eEF1{alpha} complex in inhibiting germ cell proliferation: A protein-interaction analysis in medaka (Oryzias latipes) from a proteomics perspective [Research]

Gonadal soma-derived factor (gsdf) has been demonstrated to be essential for testicular differentiation in medaka (Oryzias latipes). To understand the protein dynamics of Gsdf in spermatogenesis regulation, we used a His-tag "pull-down" assay coupled with shotgun LC-MS/MS to identify a group of potential interacting partners for Gsdf, which included cytoplasmic dynein light chain 2, eukaryotic polypeptide elongation factor 1 alpha (eEF1α), and actin filaments in mature medaka testis. As for the interaction with TGFβ-dynein being critical for spermatogonial division in Drosophila melanogaster, the physical interactions of Gsdf-dynein and Gsdf-eEF1α were identified through a yeast 2-hybrid (Y2H) screening of an adult testis cDNA library using Gsdf as bait, which were verified by a paired Y2H assay. Co-immunoprecipitation of Gsdf and eEF1α was defined in adult testes as supporting the requirement of a Gsdf and eEF1α interaction in testis development. Proteomics analysis (data are available via ProteomeXchange with identifier PXD022153) and ultrastrutural observations showed that Gsdf deficiency activated eEF1α-mediated protein synthesis and ribosomal biogenesis, which in turn led to the differentiation of undifferentiated germ cells. Thus, our results provide a framework and new insight into the coordination of a Gsdf (TGFβ and eEF1α complex in the basic processes of germ cell proliferation, transcriptional and translational control of sexual RNA which may be fundamentally conserved across phyla during sexual differentiation.




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Systematic identification of P. falciparum sporozoite membrane protein interactions reveals an essential role for the p24 complex in host infection [Research]

Sporozoites are a motile form of malaria-causing Plasmodium falciparum parasites that migrate from the site of transmission in the dermis through the bloodstream to invade hepatocytes. Sporozoites interact with many cells within the host, but the molecular identity of these interactions and their role in the pathology of malaria is poorly understood. Parasite proteins that are secreted and embedded within membranes are known to be important for these interactions, but our understanding of how they interact with each other to form functional complexes is largely unknown. Here, we compile a library of recombinant proteins representing the repertoire of cell surface and secreted proteins from the P. falciparum sporozoite and use an assay designed to detect extracellular interactions to systematically identify complexes. We identify three protein complexes including an interaction between two components of the p24 complex that is involved in the trafficking of glycosylphosphatidylinositol (GPI)-anchored proteins through the secretory pathway. Plasmodium parasites lacking either gene are strongly inhibited in the establishment of liver stage infections. These findings reveal an important role for the p24 complex in malaria pathogenesis and show that the library of recombinant proteins represents a valuable resource to investigate P. falciparum sporozoite biology.




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High-throughput and site-specific N-glycosylation analysis of human alpha-1-acid glycoprotein offers a great potential for new biomarker discovery [Research]

Alpha-1-acid glycoprotein (AGP) is an acute phase glycoprotein in blood, which is primarily synthetized in the liver and whose biological role is not completely understood. It consists of 45% carbohydrates that are present in the form of five N-linked complex glycans. AGP N-glycosylation was shown to be changed in many different diseases and some changes appear to be disease-specific, thus it has a great diagnostic and prognostic potential. However, AGP glycosylation was mainly analyzed in small cohorts and without detailed site-specific glycan information. Here, we developed a cost-effective method for a high-throughput and site-specific N-glycosylation LC-MS analysis of AGP which can be applied on large cohorts, aid in search for novel disease biomarkers and enable better understanding of AGP’s role and function in health and disease. The method does not require isolation of AGP with antibodies and affinity chromatography, but AGP is enriched by acid precipitation from 5 μl of bloodplasma in a 96 well format. After trypsinization, AGP glycopeptides are purified using a hydrophilic interaction chromatography based solid-phase extraction and analyzed by RP-LC-ESI-MS. We used our method to show for the first time that AGP N-glycan profile is stable in healthy individuals (14 individuals in 3 time points), which is a requirement for evaluation of its diagnostic potential. Furthermore, we tested our method on a population including individuals with registered hyperglycemia in critical illness (59 cases and 49 controls), which represents a significantly increased risk of developing type 2 diabetes. Individuals at higher risk of diabetes presented increased N-glycan branching on AGP’s second glycosylation site and lower sialylation of N-glycans on AGP’s third and AGP1’s fourth glycosylation site. Although this should be confirmed on a larger prospective cohort, it indicates that site-specific AGP N-glycan profile could help distinguish individuals who are at risk of type 2 diabetes.




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Moving Energy Initiative Learning Briefs

Moving Energy Initiative Learning Briefs Research paper sysadmin 29 March 2019

Drawing on experiences from Phase II of the MEI in Burkina Faso, Kenya and Jordan, these learning briefs highlight MEI’s approach to innovation, engagement with the private-sector and host communities, and gender-sensitive energy projects. The four learning papers are intended for practitioners and policymakers working in the humanitarian sector and host-country governments.

A shelf of energy appliances in a shop in Kakuma Town, Kenya. Photo credit: Gabriela Flores

Findings from Phase I of the Moving Energy Initiative (MEI) in 2015, published in the Chatham House research paper Heat, Light and Power for Refugees: Saving Lives, Reducing Costs, highlight the negative impacts of limited sustainable energy provision on the security of displaced populations. The paper also identified some of the challenges for energy programmes in this sector, such as the lack of robust data on energy access and the priorities of refugee populations.

In Phase II of the MEI, Practical Action led detailed research into the energy needs of refugees in Burkina Faso and Kenya. Chatham House analysed data on global refugee energy use in displacement contexts and produced an interactive map. Energy 4 Impact explored sustainable funding options, private-sector contract models and non-wood cooking concessions. The market development and low-carbon energy initiatives in Burkina Faso, Jordan and Kenya were managed by Practical Action and Energy 4 Impact, with the support of local partners. These partners represented the MEI at multiple conferences and events to share findings and advocate for the inclusion of displaced people in the sustainable energy agenda.

Drawing on experiences from Phase II of the MEI in Burkina Faso, Kenya and Jordan, these learning briefs highlight MEI’s approach to innovation, engagement with the private-sector and host communities, and gender-sensitive energy projects. The four learning papers are intended for practitioners and policymakers working in the humanitarian sector and host-country governments.




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The Chatham House Sustainable Laboratories Initiative: Prior Assessment Tool

The Chatham House Sustainable Laboratories Initiative: Prior Assessment Tool Other resource sysadmin 14 June 2019

Laboratories are critical for supporting effective infectious disease surveillance and outbreak response. This tool is meant to help structure a conversation between funding partners and recipient countries on how to most effectively establish or repurpose laboratories in low-resource environments.

Copyright: Getty Images/ER Productions Limited

Introduction

Laboratories are critical for supporting effective infectious disease surveillance and outbreak response, and lack of adequate laboratory capacity is a global challenge. As part of global health security initiatives, cooperative threat reduction efforts and international development programmes, sophisticated laboratories have been provided to mitigate biological threats and bolster a country’s capacity for detection, diagnosis and storage of high-consequence pathogens. Very often, these use the assumptions, standards and templates applied in high-income countries. However, it can be difficult or even impossible to sustain these facilities in low-resource environments. There can sometimes be limited local technical capacity and capability, which can result in a high reliance on imported expertise, skills, equipment and other resources. Sustainability can therefore be hard to achieve. In addition, when a funding partner withdraws, the laboratories can become disused, foundering without the trained personnel and financial resources to sustain them.

To help address this situation, a proposal gaining increasing support internationally is to adopt an approach based on a local risk assessment, whereby laboratories are appropriately and optimally tailored to the local risks and to the resources available, both in the short and longer term, without compromising biosafety and biosecurity.

A Chatham House workshop was convened in Abuja, Nigeria, in 2018 to explore what West African countries would find most appropriate in terms of building laboratory capacity, what the main challenges have been so far, and what needs to be done to improve the sustainability of laboratories in the region. It emerged that there was a need for a more structured conversation between the funding partner and recipient country early in the process – prior to embarking on the detailed planning phase for the establishment or repurposing of a laboratory. This should involve careful consideration and an assessment of existing and planned capacity, needs and contextual issues, together with proposals for how to address the issues revealed, so that any ensuing laboratory demonstrably supports the national strategy and therefore flourishes.

The purpose of this tool

This tool aims to provide a structure for such a conversation. Developed in close collaboration with international experts and West African stakeholders, it seeks to increase local ownership and help partners ensure they have given due attention to all the relevant aspects, including risks and benefits, that need to be considered at an early stage. It should provide clarity on what is needed and improve the sustainability of any laboratory project that might result from the discussions. The tool can be applied when a new laboratory is being considered, or when an existing laboratory is to be repurposed or strengthened. It is also appropriate for use with public health, veterinary and environmental laboratories. Although the tool was developed in the context of high-consequence pathogens in Africa, it is anticipated that it will find global application.

It should support recipient countries to take stock of their capacities and capabilities, identify gaps, conduct an analysis of their needs and to develop the business case that can assist in seeking the necessary political and financial support for the laboratory. Meanwhile, it should facilitate the process of due diligence for the funding partner and provide a better understanding of what the recipient country perspective and realities are, and what the scale and nature of any investment might be.




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A human cancer cell line initiates DNA replication normally in the absence of ORC5 and ORC2 proteins [DNA and Chromosomes]

The origin recognition complex (ORC), composed of six subunits, ORC1–6, binds to origins of replication as a ring-shaped heterohexameric ATPase that is believed to be essential to recruit and load MCM2–7, the minichromosome maintenance protein complex, around DNA and initiate DNA replication. We previously reported the creation of viable cancer cell lines that lacked detectable ORC1 or ORC2 protein without a reduction in the number of origins firing. Here, using CRISPR-Cas9–mediated mutations, we report that human HCT116 colon cancer cells also survive when ORC5 protein expression is abolished via a mutation in the initiator ATG of the ORC5 gene. Even if an internal methionine is used to produce an undetectable, N terminally deleted ORC5, the protein would lack 80% of the AAA+ ATPase domain, including the Walker A motif. The ORC5-depleted cells show normal chromatin binding of MCM2–7 and initiate replication from a similar number of origins as WT cells. In addition, we introduced a second mutation in ORC2 in the ORC5 mutant cells, rendering both ORC5 and ORC2 proteins undetectable in the same cells and destabilizing the ORC1, ORC3, and ORC4 proteins. Yet the double mutant cells grow, recruit MCM2–7 normally to chromatin, and initiate DNA replication with normal number of origins. Thus, in these selected cancer cells, either a crippled ORC lacking ORC2 and ORC5 and present at minimal levels on the chromatin can recruit and load enough MCM2–7 to initiate DNA replication, or human cell lines can sometimes recruit MCM2–7 to origins independent of ORC.




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Correction: Functional domain and motif analyses of androgen receptor coregulator ARA70 and its differential expression in prostate cancer. [Additions and Corrections]

VOLUME 279 (2004) PAGES 33438–33446For Fig. 1B, the second, third, and fifth panels were mistakenly duplicated during article preparation as no yeast colonies were observed in these conditions. The corrected images are presented in the revised Fig. 1B. This correction does not affect the results or conclusions of the work. The authors apologize for the error.jbc;295/50/17382/F1F1F1Figure 1B.




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How Influential Is China in Zimbabwe?

How Influential Is China in Zimbabwe? Expert comment sysadmin 20 November 2017

A trip to Beijing by Zimbabwe’s military chief was a ‘normal military exchange’, China’s foreign ministry said after the army seized power in Harare. Alex Vines examines the extent of China’s influence in Zimbabwe.

Xi Jinping arrives to a guard of honour in Harare in 2015. Photo: Getty Images.

The news that General Constantino Chiwenga had visited China only a few days before the military takeover in Zimbabwe was a coincidence that did not go unnoticed. There was also speculation after China said it was closely watching developments, but stopped short of condemning President Robert Mugabe’s apparent removal from power.

China is Zimbabwe’s fourth-largest trading partner and its largest source of investment - with stakes worth many billions of pounds in everything from agriculture to construction. Zimbabwe is the dependent partner - with China providing the largest market for its exports and much needed support to its fragile economy.

China’s relations with Zimbabwe are deep, starting during the Rhodesian Bush War. Robert Mugabe failed in 1979 to get Soviet backing, so turned to China, which provided his guerrilla fighters with weapons and training. Both countries formally established diplomatic relations at Zimbabwean independence in 1980 and Mugabe visited Beijing as prime minister the following year. He has been a regular visitor since.

For years, Zimbabwe’s officials have tried to play off China against the West, advocating the country’s ‘Look East’ strategy, particularly following the introduction of EU sanctions in 2002. Indeed, a decade ago, Mugabe told a packed rally at the Chinese-built national sports stadium in Harare: ‘We have turned east, where the sun rises, and given our back to the west, where the sun sets.’

China’s military engagement also deepened during Zimbabwe’s ‘Look East’ era. Significant purchases were made, including Hongdu JL-8 jet aircraft, JF-17 Thunder fighter aircraft, vehicles, radar and weapons. However, following a controversy about a shipment of arms in 2008, Beijing decided to list Zimbabwe for ‘limited level’ military trading.

Despite Zimbabwe’s efforts, the ‘Look East’ strategy did not bring the investment flood hoped for and a decade later, in August 2015, Mugabe openly asked for Western re-engagement in his ‘state of the nation’ address.

Now, the reality is that increasingly Chinese and Western interests - particularly those of the UK - have become aligned. Not far from each other in the outer suburbs of Harare, two of the biggest embassies in Zimbabwe are the British and the Chinese. As other embassies scaled down or closed, Beijing’s expanded. Whereas British diplomats were well connected with business, civil society and opposition figures, the Chinese invested in ‘technical support’ of the party of government Zanu-PF, including state security and the presidency. When it came to Zanu-PF politics and factionalism, Chinese diplomats were well connected and insightful and, like their Western colleagues, concerned about stability, a better investment climate and adherence to the rule of law.

President Xi Jinping visited Zimbabwe in 2015 and President Mugabe visited Beijing in January 2017. In public, the Chinese leader said his country is willing to encourage capable companies to invest in Zimbabwe. But in private, the message was that there would be no more loans until Zimbabwe stabilized its economy.

In 2016 trade between the two countries amounted to $1.1 billion, with China the biggest buyer of Zimbabwean tobacco and also importing cotton and various minerals. In return Zimbabwe imported electronics, clothing and other finished products. Chinese state construction firms have also been active, building infrastructure including Zimbabwe’s $100 million National Defence College. And last year China agreed to finance a new 650-seat parliament in Harare.

But Chinese diplomats and many businesses are waiting for better days in Zimbabwe. Some companies have found the investment climate challenging - being burned on diamonds, for example - and have looked for alternative markets. A couple of weeks ago I was in China, attending a meeting on China-Africa relations and Zimbabwe was not mentioned once. Unlike Ethiopia, Sudan, or Angola that are strategic partners, or big markets like Nigeria, Kenya and South Africa, Zimbabwe is far from being Beijing’s new priority.

So, Beijing’s interest is in a better investment climate in Zimbabwe. A clear transitional arrangement resulting in elections for a legitimate government in Harare is as much in Beijing’s interest as London’s.

The ‘Look East’ and the ‘Re-engagement with the West’ strategies have not brought about the confidence and investment that Zimbabwe needs. What Zimbabwe requires is stable and accountable government - then investors from Asia, America and Europe will seriously consider that Zimbabwe has an investment future. This was the message that Mugabe received in Beijing in January. And the one which Zimbabwe’s military chief also was given last week.

This article was originally published by BBC News.




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Mine Action in Angola: Clearing the Legacies of Conflict to Harness the Potential of Peace

Mine Action in Angola: Clearing the Legacies of Conflict to Harness the Potential of Peace Other resource sysadmin 14 June 2019

This publication draws on and updates the briefing note published following a meeting of the All- Party Parliamentary Group (APPG) on Angola on 26 April 2017. It also incorporates insights from a Chatham House Africa Programme conference session on the legacies of the Angolan Civil War, held on 23 March 2018; and draws on the Africa Programme’s research into conservation-driven development models in Southern Africa.

A mine clearance specialist in Angola preparing equipment used to look for unexploded ordnance, May 2012. Photo: Eye Ubiquitous/Contributor/Getty Images.

Almost two decades after the end of its civil war, Angola remains one of the most heavily landmine-contaminated countries in the world. The Angolan government has committed to clearing its landmines by 2025, and there is constructive collaboration between the government and mine clearing agencies in this endeavour, but the target will be achievable only if a decline in funding from international donors is reversed. International funding for mine clearance in Angola fell by more than 80 per cent between 2005 and 2017, and this sharp drop in external support has compounded the impact on domestic funding for national clearance efforts as a result of the downturn in prices for Angola’s main export commodities.

The national mine action agency, the Comissão Nacional Intersectorial de Desminagem e Assistência Humanitária (CNIDAH), is supported by the Mines Advisory Group (MAG), Norwegian People’s Aid (NPA) and the HALO Trust. By 2017, 15 years after the end of the civil war, these organizations had collectively helped clear 56 per cent of known landmine-contaminated land. State-led demining has focused principally on clearing areas designated for infrastructure projects. Now, it is critical that humanitarian demining in largely agricultural and conservation areas is prioritized to bring to an end the daily threat to Angola’s rural poor – as well as to the country’s livestock and wildlife – of injury or death as a result of landmine accidents.

Angola has some of the world’s most important remaining wilderness, including the tributary system for the unique Okavango Delta, and the country has the potential to host one of the most diverse wildlife populations on the continent. However, the presence of landmines and other remnants of the civil war render large areas of the country unsafe both for wildlife and for the local people, whose ability to derive a sustainable livelihood from their natural environment is fundamental to its protection.

Wildlife and tourism provide important economic opportunities for diversification beyond an oil-dominated economy. Critically, Angola’s economic diversification and development objectives can only be achieved if the landmines that prohibit access to land for agriculture, mining, tourism and wildlife are cleared.

There are economic opportunities for released land in the most heavily mined provinces of Cuando Cubango and Moxico. Already, some new funding for mine action in Angola, if upscaled or matched by international donors, could be transformative for its people, and for the conservation of the region’s vital biodiversity.




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SGLT-2 inhibitors for diabetes may help prevent dementia, study finds




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The road to COP27: In conversation with US Special Presidential Envoy for Climate John Kerry

The road to COP27: In conversation with US Special Presidential Envoy for Climate John Kerry 27 October 2022 — 3:00PM TO 4:00PM Anonymous (not verified) 20 October 2022 Chatham House and Online

What will progress on climate change look like at COP27?

With global attention zeroing in on COP27, policymakers and world leaders will meet in Egypt to take the next step in the fight against the climate crisis. The planet is on course to warm well beyond 1.5°C and climate hazards are increasing our exposure to climate risk. Violent and unpredictable weather events increasingly leave devastation among communities, particularly in vulnerable countries.

At the same time, the ripple effects of the conflict in Ukraine will have wide-ranging economic, social and geopolitical consequences for years to come. Whilst some finance is being made available, more is needed to properly address the damage caused by climate change and fund the transition to net zero worldwide. These challenges have become more acute as the world grapples with a growing energy crisis, the war in Ukraine and a troubling economic outlook.

Joined by US Special Presidential Envoy for Climate John Kerry, the following questions are considered:

  • Is ‘1.5 degrees’ still on track?

  • How can countries better collaborate to move to net zero faster?

  • How can we achieve progress on adaptation, climate finance, and loss and damage?

As with all members events, questions from the audience drive the conversation.

Read the transcript. 




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Improving 18F-FDG PET Quantification Through a Spatial Normalization Method

Quantification of 18F-FDG PET images is useful for accurate diagnosis and evaluation of various brain diseases, including brain tumors, epilepsy, dementia, and Parkinson disease. However, accurate quantification of 18F-FDG PET images requires matched 3-dimensional T1 MRI scans of the same individuals to provide detailed information on brain anatomy. In this paper, we propose a transfer learning approach to adapt a pretrained deep neural network model from amyloid PET to spatially normalize 18F-FDG PET images without the need for 3-dimensional MRI. Methods: The proposed method is based on a deep learning model for automatic spatial normalization of 18F-FDG brain PET images, which was developed by fine-tuning a pretrained model for amyloid PET using only 103 18F-FDG PET and MR images. After training, the algorithm was tested on 65 internal and 78 external test sets. All T1 MR images with a 1-mm isotropic voxel size were processed with FreeSurfer software to provide cortical segmentation maps used to extract a ground-truth regional SUV ratio using cerebellar gray matter as a reference region. These values were compared with those from spatial normalization-based quantification methods using the proposed method and statistical parametric mapping software. Results: The proposed method showed superior spatial normalization compared with statistical parametric mapping, as evidenced by increased normalized mutual information and better size and shape matching in PET images. Quantitative evaluation revealed a consistently higher SUV ratio correlation and intraclass correlation coefficients for the proposed method across various brain regions in both internal and external datasets. The remarkably good correlation and intraclass correlation coefficient values of the proposed method for the external dataset are noteworthy, considering the dataset’s different ethnic distribution and the use of different PET scanners and image reconstruction algorithms. Conclusion: This study successfully applied transfer learning to a deep neural network for 18F-FDG PET spatial normalization, demonstrating its resource efficiency and improved performance. This highlights the efficacy of transfer learning, which requires a smaller number of datasets than does the original network training, thus increasing the potential for broader use of deep learning–based brain PET spatial normalization techniques for various clinical and research radiotracers.




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Dual Somatostatin Receptor/18F-FDG PET/CT Imaging in Patients with Well-Differentiated, Grade 2 and 3 Gastroenteropancreatic Neuroendocrine Tumors

Our purpose was to prospectively assess the distribution of NETPET scores in well-differentiated (WD) grade 2 and 3 gastroenteropancreatic (GEP) neuroendocrine tumors (NETs) and to determine the impact of the NETPET score on clinical management. Methods: This single-arm, institutional ethics review board–approved prospective study included 40 patients with histologically proven WD GEP NETs. 68Ga-DOTATATE PET and 18F-FDG PET were performed within 21 d of each other. NETPET scores were evaluated qualitatively by 2 reviewers, with up to 10 marker lesions selected for each patient. The quantitative parameters that were evaluated included marker lesion SUVmax for each tracer; 18F-FDG/68Ga-DOTATATE SUVmax ratios; functional tumor volume (FTV) and metabolic tumor volume (MTV) on 68Ga-DOTATATE and 18F-FDG PET, respectively; and FTV/MTV ratios. The treatment plan before and after 18F-FDG PET was recorded. Results: There were 22 men and 18 women (mean age, 60.8 y) with grade 2 (n = 24) or grade 3 (n = 16) tumors and a mean Ki-67 index of 16.1%. NETPET scores of P0, P1, P2A, P2B, P3B, P4B, and P5 were documented in 2 (5%), 5 (12.5%), 5 (12.5%) 20 (50%), 2 (5%), 4 (10%), and 2 (5%) patients, respectively. No association was found between the SUVmax of target lesions on 68Ga-DOTATATE and the SUVmax of target lesions on 18F-FDG PET (P = 0.505). 18F-FDG/68Ga-DOTATATE SUVmax ratios were significantly lower for patients with low (P1–P2) primary NETPET scores than for those with high (P3–P5) primary NETPET scores (mean ± SD, 0.20 ± 0.13 and 1.68 ± 1.44, respectively; P < 0.001). MTV on 18F-FDG PET was significantly lower for low primary NETPET scores than for high ones (mean ± SD, 464 ± 601 cm3 and 66 ± 114 cm3, respectively; P = 0.005). A change in the type of management was observed in 42.5% of patients after 18F-FDG PET, with the most common being a change from systemic therapy to peptide receptor radionuclide therapy and from debulking surgery to systemic therapy. Conclusion: There was a heterogeneous distribution of NETPET scores in patients with WD grade 2 and 3 GEP NETs, with more than 1 in 5 patients having a high NETPET score and a frequent change in management after 18F-FDG PET. Quantitative parameters including 18F-FDG/68Ga-DOTATATE SUVmax ratios in target lesions and FTV/MTV ratios can discriminate between patients with high and low NETPET scores.




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Association Between CA 15-3 and 18F-FDG PET/CT Findings in Recurrent Breast Cancer Patients at a Tertiary Referral Hospital in Kenya

The tumor marker cancer antigen 15-3 (CA 15-3) is that most commonly used to monitor metastatic breast cancer during active therapy and surveillance for disease recurrence after treatment. The association of CA 15-3 and 18F-FDG PET/CT findings can be considered complementary, since any significant rise may indicate the presence of disease and imaging is able to map the tumor sites. Although current guidelines do not recommend the routine performance of CA 15-3 in asymptomatic patients being followed up after definitive breast cancer treatment, most oncologists perform serial assessment of the tumor markers as part of routine follow-up of patients. The aim of this study was to evaluate the correlation between CA 15-3 levels and 18F-FDG PET/CT scan findings in patients with recurrent breast cancer. Methods: This was a cross-sectional study with data collected retrospectively. Patients being evaluated for breast cancer recurrence with 18F-FDG PET/CT imaging and CA 15-3 level were included. Evaluation of the association between CA 15-3 levels and 18F-FDG PET/CT scan findings was then done. Results: In total, 154 cases were included in this study; 62 patients had recurrence (positive) on the 18F-FDG PET/CT scans, whereas 92 patients had normal (negative) findings on follow-up 18F-FDG PET/CT scans. There was an association between CA 15-3 levels and the presence or absence of recurrence on 18F-FDG PET/CT scans, with 84.4% (27/32) of patients who had elevated CA 15-3 levels having disease recurrence on 18F-FDG PET/CT and 84.4% (27/32) of patients who had elevated CA 15-3 levels having disease recurrence on 18F-FDG PET/CT as well as a correlation with the burden of metastases. Most patients with disease recurrence on 18F-FDG PET/CT, however, had normal CA 15-3 levels. Conclusion: Higher CA 15-3 levels correlate with breast cancer recurrence on 18F-FDG PET/CT as well as with burden of metastasis. Notably, CA 15-3 levels within the reference range do not exclude breast cancer disease recurrence since more than half of patients with recurrence had normal CA 15-3 levels. 18F-FDG PET/CT should therefore be considered in patients with suspected breast cancer recurrence but normal CA 15-3 levels.




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Mexico 'anxious' on eve of U.S. presidential election

Officials in Mexico and across Latin America are anxiously watching the outcome of Tuesday's U.S. Presidential contest in light of GOP candidate Donald Trump's campaign promise to "deport 11 million criminal aliens."




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U.S. stocks surge in early trading after presidential election

The Dow Jones Industrial Average and the S&P 500 hit new highs in early trading on Wednesday as former President Donald Trump claimed victory in Tuesday's presidential election over Kamala Harris.




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Federal Reserve to announce potential rate cut decision Thursday

Prognosticators anticipate the Federal Reserve on Thursday will announce a second rate cut after lowering the federal lending rate by 0.5% in September.




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Haitian Prime Minister Garry Conille fired by transitional council

Haiti's ruling transitional council has fired Prime Minister Garry Conille, six months after the doctor and former UNICEF Latin America head was appointed to lead the troubled nation.




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Celestial AI Acquires Rockley Photonics Patent Portfolio, Strengthening Photonic Fabric IP

SANTA CLARA, Calif., Oct. 22, 2024 — Celestial AI today announced the acquisition of silicon photonics intellectual property from Rockley Photonics, including worldwide issued and pending patents. The combination of Celestial […]

The post Celestial AI Acquires Rockley Photonics Patent Portfolio, Strengthening Photonic Fabric IP appeared first on HPCwire.




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U.S., Slovenian military officials discuss joint response to potential threats

As U.S. and Slovenian troops wrapped up a joint exercise, military officials from both countries met to discuss their response to potential threats, the Air Force said Wednesday.




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Why IT Must Have an Influential Role in Strategic Decisions About Sustainability

In this era, expansion in digital infrastructure capacity is inevitable. Parallel to this, climate change consciousness is also rising, making sustainability a mandatory part of the organization’s functioning. As computing […]

The post Why IT Must Have an Influential Role in Strategic Decisions About Sustainability appeared first on HPCwire.




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Sylabs Highlights Confidential Computing in HPC at SC24 BoF Session

ATLANTA, Nov. 12, 2024 — Sylabs, in collaboration with Sandia National Laboratories, will host a Birds of a Feather (BoF) session at SC24 titled Integrating Confidential Computing into High-Performance Cloud Workflows. […]

The post Sylabs Highlights Confidential Computing in HPC at SC24 BoF Session appeared first on HPCwire.




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Asthma Drug Still Being Prescribed to Kids Despite Potential Mental Health Risks

The allergy and asthma drug montelukast, also known as Singulair, can cause psychiatric side effects—and researchers aren’t sure why




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Excessive daytime sleepiness can lead to dementia, study indicates

Experiencing excessive daytime sleepiness as an older adult can spell dire consequences that ultimately may lead to full-blown dementia, according to a new study funded by the National Institute on Aging.





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CENTCOM strikes Iran-backed militia targets in Syria after rockets launched at U.S. forces

The U.S. military conducted retaliatory airstrikes Tuesday in Syria, targeting facilities of Iran-backed militias following rockets launched at U.S. forces in the Middle Eastern country.




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China's Shenzhou-19 crew arrives at Tiangong space station

A new trio of Chinese astronauts reached the Tiangong space station on Wednesday, starting a handover from the current crew already on the orbiting laboratory.




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The Activity That Cuts Dementia Risk By 90%

Study of women over 50 suggests how to cut dementia risk by 90 percent.




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The ‘Flavodiet’ Could Slash Your Dementia Risk By 30% (M)

A study reveals how six simple food additions could dramatically lower your dementia risk.




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Deval Patrick, Obama Education Ally, Announces Presidential Run

A businessman, Patrick served two terms as governor of Massachusetts and has credited education with his own dramatic rise to success.




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High Court Backs Oklahoma Tribe's Reservation Status, With Potential School Implications

The U.S. Supreme Court ruled that a large swath of land in Oklahoma is still an American Indian reservation, a decision that may have ramifications for education.




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Lawsuits Defy Arizona Initiative Taxing Wealthy for Schools

Two lawsuits were filed Monday challenging a proposition that Arizona voters approved to impose an additional 3.5% tax on individuals earning above $250,000 to pay school teacher salaries and training.




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Whitmer may extend partial shutdown of schools, businesses




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High Court Blocks Electronic-Signature Gathering for Idaho Education Initiative

The U.S. Supreme Court blocked an injunction that had allowed a group backing an Idaho education spending measure to collect electronic signatures because of the coronavirus pandemic.




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Washington State Teachers Strike Over Salary Negotiations

Teachers in seven districts are striking for higher pay—and Seattle may be next.




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DeVos Appoints New Leader of African-American Education Initiative

Terris Todd, a former teacher and school administrator in the Battle Creek, Mich., schools, is the ethnic vice chair of the Michigan Republican Party.




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Whitmer may extend partial shutdown of schools, businesses




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Intraneuronal beta-Amyloid Aggregates, Neurodegeneration, and Neuron Loss in Transgenic Mice with Five Familial Alzheimer's Disease Mutations: Potential Factors in Amyloid Plaque Formation

Holly Oakley
Oct 4, 2006; 26:10129-10140
Neurobiology of Disease




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Sequential Activation of Lateral Hypothalamic Neuronal Populations during Feeding and Their Assembly by Gamma Oscillations

Mahsa Altafi
Oct 23, 2024; 44:e0518242024-e0518242024
Systems/Circuits




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Intraneuronal beta-Amyloid Aggregates, Neurodegeneration, and Neuron Loss in Transgenic Mice with Five Familial Alzheimer's Disease Mutations: Potential Factors in Amyloid Plaque Formation

Holly Oakley
Oct 4, 2006; 26:10129-10140
Neurobiology of Disease




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TRIM46 Is Required for Microtubule Fasciculation In Vivo But Not Axon Specification or Axon Initial Segment Formation

Vertebrate nervous systems use the axon initial segment (AIS) to initiate action potentials and maintain neuronal polarity. The microtubule-associated protein tripartite motif containing 46 (TRIM46) was reported to regulate axon specification, AIS assembly, and neuronal polarity through the bundling, or fasciculation, of microtubules in the proximal axon. However, these claims are based on TRIM46 knockdown in cultured neurons. To investigate TRIM46 function in vivo, we examined male and female TRIM46 knock-out mice. Contrary to previous reports, we find that TRIM46 is dispensable for axon specification and AIS formation. TRIM46 knock-out mice are viable, have normal behavior, and have normal brain structure. Thus, TRIM46 is not required for AIS formation, axon specification, or nervous system function. However, we confirm that TRIM46 is required for microtubule fasciculation. We also show TRIM46 enrichment in the first ~100 μm of axon occurs independently of ankyrinG (AnkG) in vivo, although AnkG is required to restrict TRIM46 only to the AIS. Our results highlight the need for further investigation of the mechanisms by which the AIS and microtubules interact to shape neuronal structure and function.




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Sequential Activation of Lateral Hypothalamic Neuronal Populations during Feeding and Their Assembly by Gamma Oscillations

Neural circuits supporting innate behaviors, such as feeding, exploration, and social interaction, intermingle in the lateral hypothalamus (LH). Although previous studies have shown that individual LH neurons change their firing relative to the baseline during one or more behaviors, the firing rate dynamics of LH populations within behavioral episodes and the coordination of behavior-related LH populations remain largely unknown. Here, using unsupervised graph-based clustering of LH neurons firing rate dynamics in freely behaving male mice, we identified distinct populations of cells whose activity corresponds to feeding, specific times during feeding bouts, or other innate behaviors—social interaction and novel object exploration. Feeding-related cells fired together with a higher probability during slow and fast gamma oscillations (30–60 and 60–90 Hz) than during nonrhythmic epochs. In contrast, the cofiring of neurons signaling other behaviors than feeding was overall similar between slow gamma and nonrhythmic epochs but increased during fast gamma oscillations. These results reveal a neural organization of ethological hierarchies in the LH and point to behavior-specific motivational systems, the dysfunction of which may contribute to mental disorders.




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Distinct Neuron Types Contribute to Hybrid Auditory Spatial Coding

Neural decoding is a tool for understanding how activities from a population of neurons inside the brain relate to the outside world and for engineering applications such as brain–machine interfaces. However, neural decoding studies mainly focused on different decoding algorithms rather than different neuron types which could use different coding strategies. In this study, we used two-photon calcium imaging to assess three auditory spatial decoders (space map, opponent channel, and population pattern) in excitatory and inhibitory neurons in the dorsal inferior colliculus of male and female mice. Our findings revealed a clustering of excitatory neurons that prefer similar interaural level difference (ILD), the primary spatial cues in mice, while inhibitory neurons showed random local ILD organization. We found that inhibitory neurons displayed lower decoding variability under the opponent channel decoder, while excitatory neurons achieved higher decoding accuracy under the space map and population pattern decoders. Further analysis revealed that the inhibitory neurons’ preference for ILD off the midline and the excitatory neurons’ heterogeneous ILD tuning account for their decoding differences. Additionally, we discovered a sharper ILD tuning in the inhibitory neurons. Our computational model, linking this to increased presynaptic inhibitory inputs, was corroborated using monaural and binaural stimuli. Overall, this study provides experimental and computational insight into how excitatory and inhibitory neurons uniquely contribute to the coding of sound locations.




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Dopamine and Norepinephrine Differentially Mediate the Exploration-Exploitation Tradeoff

Dopamine (DA) and norepinephrine (NE) have been repeatedly implicated in neuropsychiatric vulnerability, in part via their roles in mediating the decision-making processes. Although two neuromodulators share a synthesis pathway and are coactivated under states of arousal, they engage in distinct circuits and modulatory roles. However, the specific role of each neuromodulator in decision-making, in particular the exploration–exploitation tradeoff, remains unclear. Revealing how each neuromodulator contributes to exploration–exploitation tradeoff is important in guiding mechanistic hypotheses emerging from computational psychiatric approaches. To understand the differences and overlaps of the roles of these two catecholamine systems in regulating exploration, a direct comparison using the same dynamic decision-making task is needed. Here, we ran male and female mice in a restless two-armed bandit task, which encourages both exploration and exploitation. We systemically administered a nonselective DA antagonist (flupenthixol), a nonselective DA agonist (apomorphine), a NE beta-receptor antagonist (propranolol), and a NE beta-receptor agonist (isoproterenol) and examined changes in exploration within subjects across sessions. We found a bidirectional modulatory effect of dopamine on exploration. Increasing dopamine activity decreased exploration and decreasing dopamine activity increased exploration. The modulatory effect of beta-noradrenergic receptor activity on exploration was mediated by sex. Reinforcement learning model parameters suggested that dopamine modulation affected exploration via decision noise and norepinephrine modulation affected exploration via sensitivity to outcome. Together, these findings suggested that the mechanisms that govern the exploration–exploitation transition are sensitive to changes in both catecholamine functions and revealed differential roles for NE and DA in mediating exploration.




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Differential Encoding of Two-Tone Harmonics in the Male and Female Mouse Auditory Cortex

Harmonics are an integral part of music, speech, and vocalizations of animals. Since the rest of the auditory environment is primarily made up of nonharmonic sounds, the auditory system needs to perceptually separate the above two kinds of sounds. In mice, harmonics, generally with two-tone components (two-tone harmonic complexes, TTHCs), form an important component of vocal communication. Communication by pups during isolation from the mother and by adult males during courtship elicits typical behaviors in female mice—dams and adult courting females, respectively. Our study shows that the processing of TTHC is specialized in mice providing neural basis for perceptual differences between tones and TTHCs and also nonharmonic sounds. Investigation of responses in the primary auditory cortex (Au1) from in vivo extracellular recordings and two-photon Ca2+ imaging of excitatory and inhibitory neurons to TTHCs exhibit enhancement, suppression, or no-effect with respect to tones. Irrespective of neuron type, harmonic enhancement is maximized, and suppression is minimized when the fundamental frequencies (F0) match the neuron's best fundamental frequency (BF0). Sex-specific processing of TTHC is evident from differences in the distributions of neurons’ best frequency (BF) and best fundamental frequency (BF0) in single units, differences in harmonic suppressed cases re-BF0, independent of neuron types, and from pairwise noise correlations among excitatory and parvalbumin inhibitory interneurons. Furthermore, TTHCs elicit a higher response compared with two-tone nonharmonics in females, but not in males. Thus, our study shows specialized neural processing of TTHCs over tones and nonharmonics, highlighting local network specialization among different neuronal types.




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Anterior Olfactory Cortices Differentially Transform Bottom-Up Odor Signals to Produce Inverse Top-Down Outputs

Odor information arrives first in the main olfactory bulb and is then broadcasted to the olfactory cortices and striatum. Downstream regions have unique cellular and connectivity architectures that may generate different coding patterns to the same odors. To reveal region-specific response features, tuning and decoding of single-unit populations, we recorded responses to the same odors under the same conditions across regions, namely, the main olfactory bulb (MOB), the anterior olfactory nucleus (AON), the anterior piriform cortex (aPC), and the olfactory tubercle of the ventral striatum (OT), of awake male mice. We focused on chemically closely related aldehydes that still create distinct percepts. The MOB had the highest decoding accuracy for aldehydes and was the only region encoding chemical similarity. The MOB had the highest fraction of inhibited responses and narrowly tuned odor-excited responses in terms of timing and odor selectivity. Downstream, the interconnected AON and aPC differed in their response patterns to the same stimuli. While odor-excited responses dominated the AON, the aPC had a comparably high fraction of odor-inhibited responses. Both cortices share a main output target that is the MOB. This prompted us to test if the two regions convey also different net outputs. Aldehydes activated AON terminals in the MOB as a bulk signal but inhibited those from the aPC. The differential cortical projection responses generalized to complex odors. In summary, olfactory regions reveal specialized features in their encoding with AON and aPC differing in their local computations, thereby generating inverse net centrifugal and intercortical outputs.




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G-Protein Signaling in Alzheimer's Disease: Spatial Expression Validation of Semi-supervised Deep Learning-Based Computational Framework

Systemic study of pathogenic pathways and interrelationships underlying genes associated with Alzheimer's disease (AD) facilitates the identification of new targets for effective treatments. Recently available large-scale multiomics datasets provide opportunities to use computational approaches for such studies. Here, we devised a novel disease gene identification (digID) computational framework that consists of a semi-supervised deep learning classifier to predict AD-associated genes and a protein–protein interaction (PPI) network-based analysis to prioritize the importance of these predicted genes in AD. digID predicted 1,529 AD-associated genes and revealed potentially new AD molecular mechanisms and therapeutic targets including GNAI1 and GNB1, two G-protein subunits that regulate cell signaling, and KNG1, an upstream modulator of CDC42 small G-protein signaling and mediator of inflammation and candidate coregulator of amyloid precursor protein (APP). Analysis of mRNA expression validated their dysregulation in AD brains but further revealed the significant spatial patterns in different brain regions as well as among different subregions of the frontal cortex and hippocampi. Super-resolution STochastic Optical Reconstruction Microscopy (STORM) further demonstrated their subcellular colocalization and molecular interactions with APP in a transgenic mouse model of both sexes with AD-like mutations. These studies support the predictions made by digID while highlighting the importance of concurrent biological validation of computationally identified gene clusters as potential new AD therapeutic targets.