Background: HM is a rare, severe form of migraine with aura, characterised by motor weakness and strongly influenced by genetic factors affecting the brain. While pathogenic variants in CACNA1A, ATP1A2, and SCN1A genes have been implicated in familial HM, approximately 75% of cases lack known pathogenic variants in these genes, suggesting a more complex genetic basis. Methods: To advance our understanding of HM, we applied a variant prioritisation approach using whole-exome sequencing (WES) data from patients referred for HM diagnosis (n = 184) and utilised PathVar, a bioinformatics pipeline designed to identify pathogenic variants. Our analysis incorporated two strategies for association testing: (1) PathVar-identified single nucleotide variants (SNVs) and (2) PathVar SNVs combined with missense and rare variants. Principal component analysis (PCA) was performed to adjust for ancestral and other unknown differences between cases and controls. Results: Our results reveal a sequential reduction in the number of genes significantly associated with HM, from 20 in the first strategy to 11 in the second, which highlights the unique contribution of PathVar SNVs to the genetic architecture of HM. PathVar SNVs were more distinctive in the case cohort, suggesting a closer link to the functional changes underlying HM compared to controls. Notably, novel genes, such as SLC38A10, GCOM1, and NXPH2, which were previously not implicated in HM, are now associated with the disorder, advancing our understanding of its genetic basis. Conclusions: By prioritising PathVar SNVs, we identified a broader set of genes potentially contributing to HM. Given that HM is a rare condition, our findings, utilising a sample size of 184, represent a unique contribution to the field. This iterative analysis demonstrates that integrating diverse variant schemes provides a more comprehensive view of the genetic factors driving HM.

Post-traumatic stress disorder (PTSD) is a psychiatric disorder that frequently co-occurs with pain disorders including migraine. There are proposed biological, genetic and environmental factors associated with both PTSD and migraine suggesting shared etiology. Genome-Wide Association Studies (GWAS) have been used to identify genomic risk loci associated with various disorders and to investigate genetic overlap between traits. There is a significant genetic correlation between PTSD and migraine with no evidence of a causal relationship that could be attributed to pleiotropy. Cross-disorder genetic analyses were applied to investigate the genetic overlap and causal associations using GWAS summary statistics of PTSD (n = 214408), migraine (n = 873341) and 23 medication use traits (n = 78808-305913) including anti-depressants, anti-migraine preparations and beta-blocking agents. Across the entire genome, anti-thrombotic agents had a significant and negative genetic correlation with PTSD (rG = -0.2, P FDR = 0.032) and a positive genetic correlation with migraine (rG = 0.26, P FDR = 2.23 x 10-8). PTSD showed significant genetic correlation with 11 other medication use traits including beta blocking agents (rG = -0.11, P FDR = 0.034). Of the 2495 genomic regions tested, PTSD showed significant local genetic correlation with 12 medication use traits at 43 loci; while migraine showed significant genetic correlation with only anti-inflammatory agents and anti-rheumatic products at locus 12:57522282-57607142 (DAB1) (P < 2 x 10-5). The genetic liability to PTSD had a causal effect on increased risk of using pain medication such as opioids (β ivw = 0.59, P = 5.21 x 10-5) while the genetic liability to migraine had a causal effect on the increased risk of using anti-thrombotic agents (β ivw = 0.59, P = 1.69 x 10-7). The genes in the genomic regions shared between PTSD and medication use traits were enriched in neural-related pathways such as neuron development, neurogenesis and protein kinase activity. These results provide further insight into the genetically controlled biological and environmental factors underlying the shared etiology between PTSD and migraine. The identified biomarkers can be used as a basis for investigation as potential drug targets for both disorders. These findings are significant for drug re-purposing and treatment of PTSD and migraine using monotherapy.

Chronic kidney disease (CKD) is a multifactorial condition driven by diverse etiologies that lead to a gradual loss of kidney function. Although genome-wide association studies (GWAS) have identified numerous genetic loci linked to CKD, a large portion of its genetic basis remains unexplained. This knowledge gap may partly arise from the reliance on single biomarkers, such as estimated glomerular filtration rate (eGFR), to assess kidney function. To address this limitation, we developed and applied a novel multi-phenotype approach, combinatorial Principal Component Analysis (cPCA), to better understand the complex genetic architecture of CKD. Using UK Biobank dataset (n = 337,112), we analyzed 21 CKD-related phenotypes, generating over 2 million composite phenotypes (CPs) through cPCA. Nearly 50,000 of these CPs demonstrated significantly higher classification power for clinical CKD compared to individual biomarkers. The top-ranked CP—a combination of albumin, cystatin C, eGFR, gamma-glutamyltransferase, HbA1c, low-density lipoprotein, and microalbuminuria, achieved an AUC of 0.878 (95% CI: 0.873–0.882), significantly outperforming eGFR alone (AUC: 0.830, 95% CI: 0.825–0.835). Genetic association analysis of the ~ 50,000 high-performing CPs identified all major eGFR-associated loci, except for the SH2B3 locus rs3184504, a loss-of-function variant, which was uniquely identified in CPs (p = 3.1 × 10 -56 ) but not in eGFR within the same sample size. In addition, SH2B3 locus showed strong evidence of colocalization with eGFR, supporting its role in kidney function. These results highlight the power of the multi-phenotype cPCA approach in understanding the genetic basis of CKD, with potential applications to other complex diseases.

Introduction Pain is common in cancer patients, particularly in the advanced stage of the disease with more than 70% prevalence. Despite research regarding cancer pain management, clinicians’ ability to predict and manage patient pain remains a significant challenge. Patients and Methods This sub-study of a prospective, open label, dose individualization study, investigated how selected single nucleotide polymorphisms (SNPs) in the KCNJ6, ARRB2, and BDNF genes may affect fentanyl dose requirements and response. Fifty-six adult inpatients or outpatients of oncology and pallateive care services who met the eligibility criteria were recruited Administration of transdermal fentanyl was monitored, and participant characteristics (age, height, weight, type of cancer, liver and renal function, fentanyl dose) and pain scores (numerical rating scale) recorded. SNP genotyping was conducted using pyrosequencing ( KCNJ6 and BDNF ) and TaqMan assays ( ARRB2 ). Statistical analysis included patient characteristics, observed and expected genotype frequencies, genotype and fentanyl dose/pain score, along with categories of low (≤3.0/10) or high (>3.0/10) pain scores and low (≤50 mcg/hr) or high fentanyl doses (>50 mcg/hr). Results The median fentanyl dose administered was 50 mcg/hr, with a range of 12 to 300 mcg/hr, with the mean pain score 3.0/10.0 (SD:2.3). No association was found between patient characteristics, fentanyl dose, and pain score ( P -values >0.05) in the European and Asian population. No association was found for KCNJ6 (rs2070995), ARRB2 (rs34230287, rs3786047, rs1045280, rs2036657), and BDNF (rs7934165, rs10835210, rs1491850) in relation to dose and pain score. Conclusion These results may show no association between the SNPs examined in KCNJ6 , ARRB2, and BDNF with fentanyl dose or response in the population of the study, as this was the case for the subgroups of the population we were able to divide individuals in based on allele groups. This evidence may enhance existing studies, driving the ongoing advancement and refinement of gene-drug dosing guidelines.

Stem cell therapies hold promise in addressing the burden of neurodegenerative diseases with human embryonic neural stem cells (hNSC-H9s) and bone marrow-derived human mesenchymal stem cells (hMSCs) as viable candidates. The induction of hMSC neurospheres (hMSC-IN) generate a more lineage-restricted common neural progenitor-like cell population, potentially tunable by heparan sulfate proteoglycans (HSPGs). We examined CpG (5mC) site methylation patterns using Illumina Infinium 850K EPIC arrays in hNSC-H9, hMSCs and hMSC-IN cultures with HSPG agonist heparin at early and late phases of growth. We identified key regulatory CpG sites in syndecans (SDC2; SDC4) that potentially regulate gene expression in monolayers. Unique hMSC-IN hypomethylation in glypicans (GPC3; GPC4) underscore their significance in neural lineages with Sulfatase 1 and 2 (SULF1 & 2) CpG methylation changes potentially driving the neurogenic shift. hMSC-INs methylation levels at SULF1 CpG sites and SULF2:cg25401628 were more closely aligned with hNSC-H9 cells than with hMSCs. We further suggest SOX2 regulation governed by lcSOX2-Overall Transcript (lncSOX2-OT) methylation changes with preferential activation of ENO2 over other neuronal markers within hMSC-INs. Our findings illuminate epigenetic dynamics governing neural lineage commitment of hMSC-INs offering insights for targeted mechanisms for regenerative medicine and therapeutic strategies.

The importance of epigenetic factors in ischemic stroke has become increasingly prominent. Despite this growing interest, comprehensive bibliometric analyses addressing relationships between epigenetic modification and ischemic stroke are still scarce. This study utilizes a range of bibliometric tools to methodically evaluate research advancements, detect key trends, and delineate both historical and emerging research trajectories in this area. By examining 47 pertinent publications from the Web of Science Core Collection up to July 31, 2024, the present analysis uncovers a consistent rise in global research efforts focused on epigenetics and ischemic stroke. Analyses of co-citation and bibliographic coupling reveal significant research clusters that correspond with current thematic trends. Additionally, scientific mapping and citation burst analyses provide insights into the evolving research landscape and highlight emerging areas of interest. These results emphasize the growing role of epigenetics in understanding the mechanisms of ischemic stroke and developing targeted therapeutic approaches.

Iron imbalance poses significant health risks, necessitating a comprehensive understanding of the proteins involved in iron homeostasis. This thesis focuses on identifying novel genes involved in the regulation of Ferroportin, the sole iron exporter protein. Using non-biased genome-wide CRISPR-Cas9 screening technologies, several potential regulators of Ferroportin were identified. Further investigation using siRNA gene silencing methodologies and CRISPR-Cas9 mediated gene knockout elucidated the potential roles of four novel genes in Ferroportin modulation. Additionally, a surprising link between peroxisomes and Ferroportin regulation was uncovered. These findings offer promising avenues for understanding and treating iron-related disorders.

Sirtuins (SIRTs), nicotine adenine dinucleotide (+)-dependent histone deacetylases, have emerged as critical regulators in many signalling pathways involved in a wide range of biological processes. Currently, seven mammalian SIRTs have been characterized and are found across a number of cellular compartments. There has been considerable interest in the role of SIRTs in the brain due to their role in a plethora of metabolic- and age-related diseases, including their involvement in learning and memory function in physiological and pathophysiological conditions. Although cognitive function declines over the course of healthy ageing, neurological disorders including Alzheimer’s disease (AD) can be associated with progressive cognitive impairments. This review aimed to report and integrate recent advances in the understanding of the role of SIRTs in cognitive function and dysfunction in the context of AD. We have also reviewed the use of selective and/or natural SIRT activators as potential therapeutic agents and/or adjuvants for AD.

Migraine is a common neurological disorder with large burden in terms of disability for individuals and costs for society. Accurate diagnosis and effective treatments remain priorities. Understanding the genetic factors that contribute to migraine risk and symptom manifestation could improve individual management. Migraine has a strong genetic basis that includes both monogenic and polygenic forms. Some distinct, rare, familial migraine subtypes are caused by pathogenic variants in genes involved in ion transport and neurotransmitter release, suggesting an underlying vulnerability of the excitatory-inhibitory balance in the brain, which might be exacerbated by disruption of homoeostasis and lead to migraine. For more prevalent migraine subtypes, genetic studies have identified many susceptibility loci, implicating genes involved in both neuronal and vascular pathways. Genetic factors can also reveal the nature of relationships between migraine and its associated biomarkers and comorbidities and could potentially be used to identify new therapeutic targets and predict treatment response.

Dysfunction in ion channels or processes involved in maintaining ionic homeostasis is thought to lower the threshold for cortical spreading depression (CSD), and plays a role in susceptibility to associated neurological disorders, including pathogenesis of a migraine. Rare pathogenic variants in specific ion channels have been implicated in monogenic migraine subtypes. In this study, we further examined the channelopathic nature of a migraine through the analysis of common genetic variants in three selected ion channel or transporter genes: SLC4A4, SLC1A3, and CHRNA4. Using the Agena MassARRAY platform, 28 single-nucleotide polymorphisms (SNPs) across the three candidate genes were genotyped in a case–control cohort comprised of 182 migraine cases and 179 matched controls. Initial results identified significant associations between migraine and rs3776578 (p = 0.04) and rs16903247 (p = 0.05) genotypes within the SLC1A3 gene, which encodes the EAAT1 glutamate transporter. These SNPs were subsequently genotyped in an independent cohort of 258 migraine cases and 290 controls using a high-resolution melt assay, and association testing supported the replication of initial findings—rs3776578 (p = 0.0041) and rs16903247 (p = 0.0127). The polymorphisms are in linkage disequilibrium and localise within a putative intronic enhancer region of SLC1A3. The minor alleles of both SNPs show a protective effect on migraine risk, which may be conferred via influencing the expression of SLC1A3.

Hemiplegic migraine (HM) is a rare and debilitating neurological condition with a strong genetic basis. Advances in whole exome sequencing (WES) have improved the diagnosis and treatment of HM. Candidate gene studies have identified mutations in ion channel genes including CACNA1A, ATP1A2 and SCN1A that cause HM. However, approximately 75% of HM patients are negative for these mutations, indicating there are other genes involved in disease causation. An exome-wide investigation of HM genes using WES has not yet been performed for a large HM cohort.

Migraine is a severe, debilitating neurovascular disorder. Hemiplegic migraine (HM) is a rare and debilitating neurological condition with a strong genetic basis. Sequencing technologies have improved the diagnosis and our understanding of the molecular pathophysiology of HM. Linkage analysis and sequencing studies in HM families have identified pathogenic variants in ion channels and related genes, including CACNA1A, ATP1A2, and SCN1A, that cause HM. However, approximately 75% of HM patients are negative for these mutations, indicating there are other genes involved in disease causation. In this review, we explored our current understanding of the genetics of HM. The evidence presented herein summarises the current knowledge of the genetics of HM, which can be expanded further to explain the remaining heritability of this debilitating condition. Innovative bioinformatics and computational strategies to cover the entire genetic spectrum of HM are also discussed in this review.

Cancer pain is the most feared symptom at end of life. Methadone has advantages over other opioids but is associated with significant variability in clinical response, making dosing challenging in practice. OPRM1 is the most studied pharmacogene associated with the pharmacodynamics of opioids, however reports on the association of the A118G polymorphism on opioid dose requirements are conflicting, with no reports including methadone as the primary intervention. This association study on OPRM1 A118G and response to methadone for pain management, includes a review of this genetic factor’s role in inter-patient variability. Fifty-four adult patients with advanced cancer were recruited in a prospective, multi-centre, open label dose individualization study. Patient characteristics were not shown to influence methadone response, and no significant associations were observed for methadone dose or pain score. The findings of our review of association studies for OPRM1 A118G in advanced cancer pain demonstrate the importance of taking ancestry into account. While our sample size was small, our results were consistent with European populations, but in contrast to studies in Chinese patients, where carriers of the A118G polymorphism were associated with higher opioid dose requirements. Pharmacogenetic studies in palliative care are challenging, continued contribution will support future genotype-based drug dosing guidelines.

Chronic kidney disease (CKD) is a complex condition with diverse underlying causes that lead to a progressive decline in kidney function. Genome-wide association studies (GWASs) have identified numerous genetic loci associated with CKD, yet much of the genetic basis remains unexplained. Part of the reason is that most GWASs have only assessed kidney function via single biomarkers such as estimated glomerular filtration rate (eGFR). This study employs a novel multi-phenotype approach, combinatorial Principal Component Analysis (cPCA), to better understand the genetic architecture of CKD. Utilizing a discovery cohort of white British individuals from the UK Biobank (n=337,112), we analyzed 21 CKD-related phenotypes using cPCA to generate over 2 million composite phenotypes (CPs). More than 46,000 CPs demonstrated superior performance in classifying clinical CKD compared to any single biomarker, and those CPs were most frequently comprised of eGFR, cystatin C, HbA1c, microalbuminuria, albumin, and LDL. GWASs of the top 1,000 CPs revealed seven novel genetic loci, with CST3 and SH2B3 successfully replicated in an independent Irish cohort (n=11,106). Notably, the index SNP of the SH2B3 gene, which encodes a regulator in immune responses and cytokine signaling, is a loss-of-function variant with a combined beta of -0.046 and a p-value of 3.1E-56. These results highlight the effectiveness of a multi-phenotype approach in GWASs and implicate a novel functional variant in SH2B3 in CKD phenotypes. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement NKT has been supported by a QUT postgraduate scholarship. AJM has been supported by a Queensland Health Advancing Clinical Research Fellowship. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This research has been conducted using the UK Biobank Resource under Application Number 60111. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The summary statistics are publicly available in Figshare repository at https://doi.org/10.6084/m9.figshare.26122540.v1.

Sirtuins (SIRTs), nicotine adenine dinucleotide (+)-dependent histone deacetylases, have emerged as critical regulators in many signalling pathways involved in a wide range of biological processes. Currently, seven mammalian SIRTs have been characterized and are found across a number of cellular compartments. There has been considerable interest in the role of SIRTs in the brain due to their role in a plethora of metabolic- and age-related diseases, including their involvement in learning and memory function in physiological and pathophysiological conditions. Although cognitive function declines over the course of healthy ageing, neurological disorders including Alzheimer's disease (AD) can be associated with progressive cognitive impairments. This review aimed to report and integrate recent advances in the understanding of the role of SIRTs in cognitive function and dysfunction in the context of AD. We have also reviewed the use of selective and/or natural SIRT activators as potential therapeutic agents and/or adjuvants for AD.

The exponential growth of next-generation sequencing (NGS) data requires innovative bioinformatics approaches to unravel the genetic underpinnings of diseases. Hemiplegic migraine (HM), a debilitating neurological disorder with a genetic basis, is one such condition that warrants further investigation. Notably, the genetic heterogeneity of HM is underscored by the fact that approximately two-thirds of patients lack pathogenic variants in the known causal ion channel genes. In this context, we have developed PathVar, a novel bioinformatics algorithm that harnesses publicly available tools and software for pathogenic variant discovery in NGS data. PathVar integrates a suite of tools, including HaplotypeCaller from the Genome Analysis Toolkit (GATK) for variant calling, Variant Effect Predictor (VEP) and ANNOVAR for variant annotation, and TAPES for assigning the American College of Medical Genetics and Genomics (ACMG) pathogenicity labels. Applying PathVar to whole exome sequencing data from 184 HM patients, we detected 648 variants that are probably pathogenic in multiple patients. Moreover, we have identified several candidate genes for HM, many of which cluster around the Rho GTPases pathway. Future research can leverage PathVar to generate high quality, candidate pathogenic variants, which may enhance our understanding of HM and other complex diseases.

BACKGROUND AND AIMS:Cerebral small vessel diseases (CSVDs) are a set of conditions that affect the small blood vessels in the brain and can cause severe neurological pathologies such as stroke and vascular dementia. The most common monogenic CSVD is cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) which is caused by mutations in NOTCH3. However, only 15-20% of CADASIL cases referred for genetic testing have pathogenic mutations in NOTCH3. We hypothesise that other monogenic causes of CSVD may be causing a CADASIL-like CSVD phenotype. METHODS:To test this, we performed whole exome sequencing for 50 individuals suspected of having CADASIL, but did not exhibit a disease-causing mutation in NOTCH3, and applied targeted analysis of all monogenic forms of CSVD. RESULTS:This analysis identified three mutations affecting the Collagen type IV genes in three individuals likely to be causative of CSVD. CONCLUSIONS:This suggests that screening for all monogenic forms of CSVD when one monogenic form is clinically suspected may improve diagnosis in clinically suspected monogenic CSVD. However, despite these findings, the majority of NOTCH3 negative CSVD cases did not have candidate mutations in known CSVD genes, suggesting that additional genetic factors contributing to the disease are yet to be identified.

Hemiplegic migraine (HM) is a rare subtype of migraine with aura. Given that causal missense mutations in the voltage-gated calcium channel α1A subunit gene CACNA1A have been identified in a subset of HM patients, we investigated whether HM patients without a mutation have an increased burden of such variants in the “CACNA1x gene family”. Whole exome sequencing data of an Australian cohort of unrelated HM patients (n = 184), along with public data from gnomAD, as controls, was used to assess the burden of missense variants in CACNA1x genes. We performed both a variant and a subject burden test. We found a significant burden for the number of variants in CACNA1E (p = 1.3 × 10−4), CACNA1H (p < 2.2 × 10−16) and CACNA1I (p < 2.2 × 10−16). There was also a significant burden of subjects with missense variants in CACNA1E (p = 6.2 × 10−3), CACNA1H (p < 2.2 × 10−16) and CACNA1I (p < 2.2 × 10−16). Both the number of variants and number of subjects were replicated for CACNA1H (p = 3.5 × 10−8; p = 0.012) and CACNA1I (p = 0.019, p = 0.044), respectively, in a Dutch clinical HM cohort (n = 32), albeit that CACNA1I did not remain significant after multiple testing correction. Our data suggest that HM, in the absence of a single causal mutation, is a complex trait, in which an increased burden of missense variants in CACNA1H and CACNA1I may contribute to the risk of disease.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a condition caused by mutations in NOTCH3 and results in a phenotype characterised by recurrent strokes, vascular dementia and migraines. Whilst a genetic basis for the disease is known, the molecular mechanisms underpinning the pathology of CADASIL are still yet to be determined. Studies conducted at the Genomics Research Centre (GRC) have also identified that only 15-23% of individuals clinically suspected of CADASIL have mutations in NOTCH3. Based on this, whole exome sequencing was used to identify novel genetic variants for CADASIL-like cerebral small-vessel disease (CSVD). Analysis of functionally important variants in 50 individuals was investigated using overrepresentation tests in Gene ontology software to identify biological processes that are potentially affected in this group of patients. Further investigation of the genes in these processes was completed using the TRAPD software to identify if there is an increased number (burden) of mutations that are associated with CADASIL-like pathology. Results from this study identified that cell-cell adhesion genes were positively overrepresented in the PANTHER GO-slim database. TRAPD burden testing identified n = 15 genes that had a higher number of rare (MAF < 0.001) and predicted functionally relevant (SIFT < 0.05, PolyPhen > 0.8) mutations compared to the gnomAD v2.1.1 exome control dataset. Furthermore, these results identified ARVCF, GPR17, PTPRS, and CELSR1 as novel candidate genes in CADASIL-related pathology. This study identified a novel process that may be playing a role in the vascular damage related to CADASIL-related CSVD and implicated n = 15 genes in playing a role in the disease.

Errors in ancestry prediction for historical military casework result in soldiers unable to be interred to the country they fought and died for. Australian WWII soldiers with varying degrees of European and Asian heritage are expected in the remains recovered in the Asia-Pacific, representing the greatest risk of error for Unrecovered War Casualties-Army (UWC-A). Previous research using the Ghaiyed population-specific panel (GPSP), on a modern British sample, demonstrated less variation in family-level admixture compared to four global ancestry panels. This suggested that the targeting of specific populations of interest may improve accuracy, although an evaluation using a sample of WWII-era European-Australians (W2A) with varying degrees of family-level admixture was required. This paper outlines the development of an ancestry prediction strategy using a W2A sample (non-admixed), and simulation of 4,000 genotypes representing Australian pedigrees with one Japanese ancestor (great-great-grandparent, great-grand-parent, grandparent, and parent). All great-great-grandparent to grandparent profiles were accurately predicted as W2A individuals, and although admixture at the parent level could not be resolved, no profiles were incorrectly assigned Japanese ancestry. The GPSP provided more informative predictions in contrast with the mitochondrial DNA/Y-chromosome lineage approach currently used by UWC-A as the GPSP provides an approximately 75% improvement.