Marginal Analysis Research Articles

Sports and Nutrition: A Scientometric Review

Sports nutrition, a dynamic field, benefits competitive athletes. This study examines its evolution through Scopus and Web of Science trends. The authors employed ScientoPy software to analyse various publications, prominent sports (and) nutrition research areas, (pro)active authors in the field, keywords, popular sources, and institutional information. This study exploited the data reconciliation, cluster mapping, webmetric, and scientometric methodologies to analyse 1527 individual entries from the Scopus and Web of Science databases. These databases revealed that the most popular subject matters in the field were "sports nutrition" and "sport Science," with "sports nutrition" having the most 'keynoted' word in most nutrition and dietetics journals since 2019. "Muscle" is the second most popular subject matter in sports and nutrition, demonstrating its reputation in this study area, also experiencing a meteoric rise in popularity since 2019. Our findings showed the top five most popular keywords that gained traction (on a marginal analysis base) were "Sports nutrition," "Exercise," "Sports performance," "Nutrition," and "Dietary supplements." The study's contribution to sports and nutrition is that it grants readers and future researchers a spectrum of past and current sports nutrition trends. Also, the analysis from the study will help future researchers forecast potential industry trends.

Fasting plasma glucose level and in-hospital cardiac arrest in patients with acute coronary syndrome: findings from the CCC-ACS project

Background The prognosis of patients with coronary artery disease is adversely affected by elevated fasting plasma glucose (FPG) levels. However, the relationship between FPG levels and in-hospital cardiac arrest (IHCA) remains unclear. Objectives The objective of this study was to investigate the association between FPG levels and IHCA in patients diagnosed with acute coronary syndrome (ACS). Methods Data from a total of 31,726 ACS patients fitted with inclusion and exclusion criteria across 241 hospitals in the Improving Care for Cardiovascular Disease in China-ACS project from November 2014 to July 2019 were collected. Different logistic regression models were utilized to examine the associations of FPG levels with IHCA. Sensitivity analyses were then conducted to assess the robustness of the findings. Marginal effect analyses were also employed to evaluate the impact of different therapies. Results A total of 335 cases of IHCA and 293 in-hospital mortality were recorded throughout the study. A non-linear relationship between FPG levels and IHCA was identified after adjusting for the covariates. Specifically, a significant association was found between elevated FPG levels (≥6.1 mmol/L) and an increased risk of IHCA. These findings remained consistent across different subgroup analyses including both the diabetic and non-diabetic patients. Additionally, the marginal effect analyses revealed that percutaneous coronary intervention could lower the high FPG-related risk. Conclusions The study findings showed a positive correlation between FPG levels and a higher incidence of IHCA, irrespective of the presence of diabetes.

ANALISIS SALURAN PEMASARAN LADA PUTIH DI DESA AIR GEGAS KECAMATAN AIR GEGAS KABUPATEN BANGKA SELATAN

This research aims to: (1) determine pepper marketing channels (2) calculate pepper marketing margin (3) calculate pepper farmer share (4) analyze pepper marketing efficiency in Air Gegas Village. The research method used in this research is the survey method. The sampling technique used snowball sampling and the number of samples was 10 farmers and 2 trader collectors. The data collection methods used were interviews, observation and questionnaires. The data analysis method uses qualitative analysis, marketing margin analysis, farmer share analysis and marketing efficiency analysis. The research results show that 1) the marketing channels for pepper in Air Gegas Village are indirect selling and collecting traders as intermediaries. 2). The average marketing margin for pepper in Air Gegas Village is Rp. 4,500/kg. 3). The average farmer share of pepper in Air Gegas Village is 96.4%. 4). The average pepper marketing efficiency in Air Gegas Village is 1.83%.

Mohs Micrographic Surgery: A Brief Overview

AbstractMohs micrographic surgery (MMS) is a tissue-sparing skin cancer resection technique that involves 100% margin analysis. This procedure is performed in the outpatient setting under local anesthesia by dermatologic surgeons who act as both the surgeon and the pathologist. The technique allows for prompt reconstruction immediately after cancer clearance and offers the highest cure rate for many skin malignancies, including basal and squamous cell carcinoma, as well as more rare tumors. Mohs surgery effectively ensures cancer clearance while minimizing defect size and optimizing cosmetic and functional outcomes for patients. Herein we will discuss the evolution, procedure, and indications of MMS.

Economic effects of priority setting in healthcare: a scoping review of current evidence

ObjectivesStudy objective was to map the current literature on the economic effects of priority setting at the system level in healthcare.DesignThe study was conducted as a scoping review.Data sourcesScopus electronic database was searched in June 2023.Eligibility criteriaWe included peer-reviewed articles published 1 January 2020–1 January 2023. All study designs that contained empirical evidence on the financial effects or opportunity costs of healthcare priority setting were included excluding disease, condition, treatment, or patient group-specific studies.Data extraction and synthesisTwo independent researchers screened the articles, and two additional researchers reviewed the full texts and extracted data. We used Joanna Briggs Institute checklists to assess the quality of qualitative, quasi-experimental and economic evaluations and the mixed methods appraisal tool for the mixed method studies. Synthesis was done qualitatively and through descriptive statistics.Results8869 articles were screened and 15 fulfilled the inclusion criteria. The most common study focus was health technology assessment (7/15). Other contexts were opportunity costs, effects of programme budgeting and marginal analysis, and disinvestment initiatives. Priority setting activities analysed in the studies did not achieve cost savings or cost containment (4/15) or have mixed findings at best (8/15). Only five studies found some indication of cost savings, cost containment or increased efficiency. Also, many of the studies consider costs only indirectly or qualitatively.ConclusionsAll in all, there is very little research addressing the pressing question of whether explicit priority setting and priority-setting methods can support cost containment on a health service system level (regional or national). There is limited evidence of the economic effects of priority setting.

Social risk assessment of the transition from internal combustion engine vehicles to electric vehicles: Material supply chains in China, Japan, and South Korea

In order to reduce carbon emissions, the production of internal combustion engine vehicles (ICEVs) is being transitioned to the production of electric vehicles (EVs). However, the social unsustainability of this process needs further testing. This study explored the social risk characteristics of the transition from ICEVs to EVs based on the Social Hotspots Database (SHDB), combining with the Social Life Cycle Assessment (SLCA) and the Marginal Analysis Method (MAM). Here, we revealed the differences in social risks in the material supply chains between China, Japan, and South Korea, which may create incentives for 100 % supply concentration in a hypothetical game. In terms of social risk, common substitution trends in the iron‑aluminum sector and synergy patterns in the copper-rubber sector were observed in the three countries. As a key factor influencing social risks, cost factor may change, and cost changes due to transition were mainly influenced by production adjustments and sourcing differences, reflecting differences in production capacity trends. This study makes it possible to consider ICEVs and EVs as two endpoints for transition activity in a SLCA exercise and provides valuable insights focusing on transition, aiding in material selection for future product design and underscoring the importance of proactive consideration of social sustainability indices.

The Role of Sorghum in Enhancing Food Security Among Smallholder Farmers in Makueni County, Kenya

In the wake of climate change and prevailing food insecurity, there has been increased attention on crops that can withstand harsh climatic conditions and have the potential to sustain livelihoods. Sorghum (<i>Sorghum bicolor)</i> is among the cereal crops with the potential to address these unprecedented challenges. It grows in arid and semi-arid regions characterized by unpredictable weather patterns, rising poverty levels, and food insecurity. In Kenya, sorghum ranks third in terms of production and importance. Nevertheless, there is prevailing food insecurity in Makueni County, where sorghum thrives well. Hence, the purpose of this study was to assess the role of sorghum in enhancing food security among smallholder farmers by establishing the potential factors influencing sorghum production and income from sorghum. A multistage sampling method was used to select a sample of 96 respondents. Data analysis involved the use of multiple linear regression model and gross margin analysis. The results indicated that experience, household size, and extension service influence sorghum production positively, while distance to all-weather roads and off-farm income have a negative effect. Gross margin results revealed sorghum is a profitable enterprise with an average net farm income of about 10,760 KES per acre. This suggests that sorghum production improves the income of sorghum-producing households and consequently enhances food security. The study, therefore, proposes strategies such as developing appropriate training facilities and strengthening extension services to boost sorghum production and thus promote food security among smallholder farmers. Furthermore, national and county governments should develop efficient road networks and provide incentives to sorghum producers to enhance access to services and markets, and foster specialization in sorghum enterprise.

ECONOMIC ANALYSIS OF MILLET PRODUCTION IN JERE LOCAL GOVERNMENT AREA, BORNO STATE, NIGERIA.

This research was carried out to determine the profitability of millet production in Jere local Government area of Borno state. Random sampling technique was adopted in this research through which data was collected from ninety (90) farms with the aid of a well-structured questionnaire. Data was analysed using descriptive statistics, gross margin analysis and production functions. Result indicated that 58.9% of respondents were in their economically active age group, majority (76.7%) of the farmers were male, 66.7% were married, while 42.2% had farming experience of between 21 – 30 years in millet production and it was revealed that farms were on a small-scale basis. Result further showed that millet production was profitable with gross margin and net farm income of N29,743.18 and N12,868.00 per hectare respectively. Regression model estimated revealed that double-log was the lead equation with R2 of 68.5%. Also, land, labour and agrochemical had significant impact on the level of millet output at P<0.01 level of probability and F-ratio 35.212. Estimated efficiency ratios showed that land; labour and fertilizer were under-utilised, while agrochemical was over utilised. Return to scale gave a value of 1.27 which implies that millet production was in stage 1 of the production region. It can be concluded that millet production in the study area is profitably. The study recommends that farmers should employ more land; labour and fertilizer, while the use of agrochemical should be cut down in order to improved millet production output for profit maximization.

Financial Determinants of Adoption of Agricultural Technologies in Irish Potato Production in Ol Kalou Sub County, Kenya: Application of Multinomial Logistic Regression

Irish potato is a significant source of food and income for many households worldwide. The demand for the crop has steadily increased around the globe. Kenyan Irish potato farmers have the potential to produce about 30 tonnes per Ha. However, small-scale Irish farmers in the country realize low output ranging from 4-8 tonnes per Ha due to limited uptake of agricultural technologies. This study aimed to analyze the financial factors influencing the uptake of agricultural technologies in Irish potato production in Ol Kalou Sub County. The agricultural technologies under investigation were chemical fertilizer, certified seeds, fungicides, and farm machinery. Production and innovation diffusion theories guided the study. Descriptive cross-sectional research design was used to obtain data from a study population of 21,942 smallholder Irish potato farmers in Ol Kalou Sub County. A multiple-stage sampling technique was employed to give a sample size of 385 respondents small scale Irish potato farmers, where data was collected through a semi-structured questionnaire. Data collected was analyzed using multinomial logistic regression through SPSS version 28 and STATA version 17. The model indicated that off-farm income, access to credit, and production risk had a positive and significant influence on adopting agricultural technologies. Conversely, production cost had a negative and significant influence on the adoption of agricultural technologies, while the availability of subsidies had no significant influence. The Marginal effect analysis showed that the availability of off-farm income increased adoption by 22.00%, the increase in credit increased adoption by 2.00%, the availability of mitigation measures of production risk increased adoption by 19.00%, while the increase in production cost decreased adoption by 7.00%. The study concluded that off-farm income, credit facilities, production risk and cost of production influence the adoption of agricultural technologies. The study recommended that the government should develop policy regulations such as diversification of income, grants that reduce production costs, credit incentives, and crop insurance.

Metabolic light absorption, scattering, and emission (MetaLASE) microscopy.

Optical imaging of metabolism can provide key information about health and disease progression in cells and tissues; however, current methods have lacked gold-standard information about histological structure. Conversely, histology and virtual histology methods have lacked metabolic contrast. Here, we present metabolic light absorption, scattering, and emission (MetaLASE) microscopy, which rapidly provides a virtual histology and optical metabolic readout simultaneously. Hematoxylin-like nucleic contrast and eosin-like cytoplasmic contrast are obtained using photoacoustic remote sensing and ultraviolet reflectance microscopy, respectively. The same ultraviolet source excites endogenous Nicotinamide adenine dinucleotide (phosphate), flavin adenine dinucleotide, and collagen autofluorescence, providing a map of optical redox ratios to visualize metabolic variations including in areas of invasive carcinoma. Benign chronic inflammation and glands also are seen to exhibit hypermetabolism. MetaLASE microscopy offers promise for future applications in intraoperative margin analysis and in research applications where greater insights into metabolic activity could be correlated with cell and tissue types.

TARGETING RESIDUAL CANCER FROM THE INVASIVE MARGIN OF GLIOBLASTOMA USING COMPUTATIONAL TOOLKITS

Abstract AIMS Infiltrative margin GBM, as a proxy for residual disease post-surgery, can be identified by 5-aminolevulininc acid (5ALA) to facilitate the discovery of uniquely expressed or upregulated molecular pathways. Complementary bioinformatics approaches offer reproducible ways to enable interoperability of heterogenous data sources towards identification of therapeutic targets associated with GBM infiltration. METHOD RNA-seq primary tumour data was first categorised as: 5ALA+ (infiltrative margin) vs tumour core and 5ALA+ vs 5ALA- (reactive brain). Two levels of filtration (genes with adjusted p-value <0.05; degree of fold change with log2>1.5) were applied to genes, creating two separate gene lists. Cross-referencing gene lists identified transcripts upregulated in both 5ALA+ vs core and 5ALA+ vs 5ALA-. This candidate gene list was inputted into STRING to generate an uncurated protein-protein interaction (PPI) network, which returned a significant PPI enrichment p-value to confirm network connectivity, and next inputted into Metascape to elucidate biological processes associated with tumour infiltration. RESULTS Of 141 upregulated 5ALA+ genes TCP10L3, HELT, MGAM, ALOX5 and FOXI1 exhibited the greatest fold change. The most prevalent 5ALA+ biological processes were primitive streak formation, disaccharide metabolic process and sodium ion transmembrane transport. LOC157273, LINC00200, LINC00656, LOC285626 and LINC01568 were identified as long non-coding RNAs (lncRNA) most abundant in the infiltrative margin of GBM relative to tumour core and reactive brain. Regulatory associations between candidate 5ALA+ lncRNA and genes, and in silico drug repurposing via molecular docking, are being investigated. CONCLUSION The plasticity of GBM warrants analysis of the GBM infiltrative margin via computational toolkits to enhance understanding of upregulated molecular pathways, functionally associated with an invasive phenotype.

Contextual Factors Predictive of Social-Emotional Functioning Among Children of Mothers With and Without Low Intellectual Functioning

This study used Future of Families Child and Wellbeing Study data to examine community, family, and maternal predictors of social-emotional outcomes for kindergarten-aged children of mothers with and without low intellectual functioning. Multivariate analysis of variance and multivariate regression explored relationships between maternal intellectual functioning, covariates, and outcomes. As poverty was an important covariate, predictive of outcomes, marginal analysis was used to understand the interaction between poverty and intellectual functioning on each of the outcomes. Children whose mothers had low intellectual functioning had poorer outcomes than their peers regarding positive, anxious/depressed, and withdrawn behaviors regardless of poverty level. This research supports prioritizing these children for early social-emotional education as they enter elementary school, as well as prioritizing their families for supportive interventions in community-based settings.

Contrast-Enhanced Digital Mammography for the Diagnosis and Determination of Extent of Disease in Invasive Lobular Carcinoma: Our Experience and Literature Review.

Contrast-enhanced imaging, including magnetic resonance imaging and, more recently, contrast-enhanced digital mammography (CEM), is indicated for the precise diagnosis of invasive lobular carcinoma (ILC). The aim of our study was to further validate the use of CEM for evaluation of extent of disease in ILC cases, with digital breast tomosynthesis (DBT) as an adjunct. A retrospective, institutional review board approved study was conducted in a tertiary medical center. All CEM examinations performed on ILC patients between 2017 and 2023 were reread by 2 dedicated breast radiologists. Clinical data and pathology reports were retrieved from electronic medical records. The longest diameter of the enhancing lesion was correlated to pathology findings. In addition, for each case, the readers provided brief commentary on the added value of DBT. Twenty-four CEM examinations were evaluated. The subjects in the study cohort were on average older than expected for ILC patients (74 vs 63 years) and were unable to undergo breast magnetic resonance imaging due to advanced age and comorbidities. Three subjects were treated with neoadjuvant therapy and thus were excluded from the correlation to pathology analysis. Enhancing lesions, ranging from 4-75 mm, strongly correlated to pathology results, with statistical significance. This was demonstrated for mass and nonmass lesions (r = 0.94, P < 0.001 and r = 0.99, P = 0.002, respectively). For most lesions (17/24, 71%), readers remarked that the addition of DBT allowed for improved characterization of lesion margins, mainly detecting architectural distortion. When compared with the pathology findings, ILC was accurately diagnosed and assessed using CEM. The addition of DBT was reported by the interpreting radiologists as a valuable adjunct for margin analysis.

Which socio-economic groups benefit most from public health expenditure in Senegal? A dynamic benefit incidence analysis

Despite efforts to enhance public investment in Senegal’s health sector, the equitable distribution of benefits between socioeconomic groups remains largely unexplored. To address this gap, our study examines the progressive (or regressive) nature of public health expenditure. Utilizing data from the latest survey on household living conditions (2018–2019) in conjunction with administrative data on health expenditure from the same period (provided by the Ministry of Health of Senegal), we performed a benefit incidence analysis. This entailed segmenting the population by poverty quintiles and subsequently estimating how each group utilized and benefitted from public health expenditure, according to level of care and geographical location. Additionally, we performed a marginal benefit analysis to discern the impact of an increase in public health expenditure on various socioeconomic groups. Our findings unveil a pro-rich distribution of benefits at both primary healthcare and hospital levels, observable both at national and regional levels. Moreover, disparities in the distribution of resource allocation between Senegal's 14 administrative regions were observed. Ultimately, our results indicate that under prevailing conditions, increasing public health expenditure would not yield a pro-poor distribution of benefits. Therefore, our research underscores the imperative of better targeting populations for greater equity between regions and social groups.

A systematic scoping review exploring variation in practice in specimen mammography for Intraoperative Margin Analysis in Breast Conserving Surgery and the role of artificial intelligence in optimising diagnostic accuracy

PurposeSpecimen Mammography (SM) is commonly used in Breast Conserving Surgery (BCS) for intraoperative margin analysis. A systematic scoping review was conducted to identify sources of methodological variation in Specimen Mammography Interpretation (SMI) and assess the role of Artificial Intelligence (AI) techniques to optimise Diagnostic Accuracy (DA). MethodsEmbase, Pubmed, Cochrane and web of science databases were searched. Studies were included if SM was used for margin analysis for BCS with reported DA compared with pathological margin status and data extracted. Results1242 unique studies were identified, of which 40 were included. 39/40 studies did not utilise AI for SMI, with 4 studies comparing 2 relevant techniques, giving 43 non-AI study arms for analysis. There was wide variation in SM techniques, including number of views and location of SM. Specialist performing SMI in usual clinical practice was surgeon (13/39 studies;33 %), radiologist(s) (16/39;41 %), surgeon and radiologist (3/39;8 %) or not stated (7/39;18 %) which differed from the study specialist in 15/39 (38 %) of studies. Diagnostic accuracy in studies ranged from sensitivity 19–91.7 % and specificity 25–100 %. ConclusionsThere is marked variation in current techniques used for SM for intraoperative margin analysis with correspondingly disparate DA. Only 1 study applied AI to SMI, and we identify how AI could optimise SMI and a template for future work to apply AI techniques to SMI, reduce unwarranted variation and optimise DA.

Visual pathology reports for communication of final margin status in laryngeal cancer surgery

BackgroundPositive margins are frequently observed in total laryngectomy (TL) specimens. Effective communication of margin sampling sites and final margin status between surgeons and pathologists is crucial. In this study, we evaluate the utility of multimedia visual pathology reports to facilitate interdisciplinary discussion of margin status in laryngeal cancer surgery. MethodsEx vivo laryngeal cancer surgical specimens were three-dimensional (3D) scanned before standard of care pathological analysis. Using computer-aided design software, the 3D model was annotated to reflect inking, sectioning, and margin sampling sites, generating a visual pathology report. These reports were distributed to head and neck surgeons and pathologists postoperatively. ResultsFifteen laryngeal cancer surgical specimens were 3D scanned and virtually annotated from January 2022 to December 2023. Most specimens (73.3%) were squamous cell carcinomas (SCCs). Among the cases, 26.7% had final positive surgical margins, whereas 13.3% had close margins, defined as <5 mm. The visual pathology report demonstrated sites of close or positive margins on the 3D specimens and was used to facilitate postoperative communication between surgeons and pathologists in 85.7% of these cases. Visual pathology reports were presented in multidisciplinary tumor board discussions (20%), email correspondences (13.3%), and teleconferences (6.7%), and were referenced in the final written pathology reports (26.7%). Conclusions3D scanning and virtual annotation of laryngeal cancer specimens for the creation of visual pathology reports is an innovative approach for postoperative pathology documentation, margin analysis, and surgeon–pathologist communication.

Analysis of safety margin for pump-turbine “S” characteristics of Pumped-storage Power Stations

Abstract The pump-turbine is the “heart” of Pumped-storage Power Stations, and the “S” characteristics is an inherent characteristic of the routine Francis pump-turbine unit, which is an important factor affecting the safe and stable operation of the unit. There are three main methods for conducting research on the “S” characteristics: model testing, on-site testing, and CFD numerical simulation calculation. Based on the theoretical research of CFD numerical simulation calculation, this article compares and analyzes the results of model testing and on-site testing for specific practical cases, studies the differences between these two methods, and provides suggestions for the reasonable value of safety margin in the “S” area of the pump-turbine based on engineering practice, providing reference for the design of new or renovated power stations and the hydraulic optimization of pump-turbines.

Long-Term Outcomes of Pneumatic Balloon Dilation versus Peroral Endoscopic Myotomy in Type I and II Achalasia Patients: A Propensity Score-Matched Analysis

Peroral esophageal myotomy (POEM) shows higher efficacy than pneumatic balloon dilation (PBD) for type I and II achalasia over 2 years. However, long-term durability beyond 5 years remains under investigated. This study aimed to assess the long-term efficacy of PBD versus POEM. This retrospective comparative study examined treatment-naïve achalasia patients who underwent either PBD or POEM. Cohort balance was achieved through propensity score (PS) matching based on age, sex, Eckardt's score, and Charlson's comorbidity index. The primary outcome was the time-to-second intervention. Secondary outcomes included treatment failure, Eckardt's score, number of intervention sessions, weight gain, and adverse events. Of the 127 patients, 67 underwent PBD and 60 underwent POEM, with an average follow-up of 7 years (IQR 5-10 years). After PS matching, 100 patients with 1:1 matching were included in the analysis. Baseline characteristics, including clinical, endoscopic, and manometric attributes, were comparable between groups. The POEM group had a significantly longer time-to-second intervention than the PBD group (hazard ratio 0.139, 95% CI 0.048-0.405) and underwent more endoscopic sessions (p< 0.001 by linear marginal model analysis) within the first 2 years. Beyond 2 years, subsequent interventions were comparable between groups. There were no differences in the Eckardt score or weight gain. Hospital stays were shorter in the PBD group (2 vs. 4 days; p < 0.001). POEM patients had more adverse events, including perforation. POEM demonstrated greater long-term durability than PBD, but PBD was associated with shorter hospital stays and fewer adverse events.

Energy coupling and surge wave superposition of upstream series double surge tanks of pumped storage power station

Pumped storage power station with surge tank is common, and surge wave superposition can cause more dangerous water levels. This paper aims to study the energy coupling and surge wave superposition of upstream series double surge tanks of pumped storage power station. Firstly, the simulation model of pumped storage power station based on method of characteristics is established. Combined operating conditions are illuminated. Then, surge wave control strategies coupling gravitational search algorithm, relative objective proximity and marginal analysis principle are designed. Coupling control domains are determined to perform surge wave superposition analyses under single objective and multi-objective. Finally, the energy coupling and conversion mechanisms are revealed. The results show that the coupling control domains of combined operating conditions with same initial operating condition are the same. Control domains for undamped and damped systems contain two and three sub control domains, respectively. Based on energy conversion mechanisms between discharges and water levels, the number of discharge superposition points of pipelines affects energy coupling strength by changing coupling oscillations of water levels in surge tanks, which is related to the pipeline parameters, surge tank parameters and system damping. Energy coupling affects surge wave superposition by changing the actual control water level.

Marginal stability analyses for thermochemical convection and its implications for the dynamics of continental lithosphere and core–mantle boundary regions

SUMMARY Significant compositional differences may exist in the lithospheric mantle and above the core–mantle boundary (CMB) relative to the ambient mantle. The intrinsic density differences may affect the development of thermal boundary layer (TBL) instabilities associated with lithospheric delamination and formation of thermochemical plumes. In this study, we explored the instability of two-layer thermochemical fluid using two different techniques: marginal stability analysis with a propagator-matrix method and finite element modelling. We investigated both the instabilities in lithospheric mantle (i.e. lithospheric instability) and the mantle above the CMB (i.e. plume-forming instability) using a background temperature Tbg(z) with the TBL. For lithospheric instability, we found that two-layer fluid with free-slip boundary conditions mainly undergoes the same three different convective modes (i.e. two oscillatory convection modes and one layered convection regime) as that with no-slip boundary conditions reported in Jaupart et al. However, with free-slip boundary conditions, the transitions between these convection modes occur at larger values of buoyancy number B. Free-slip boundary conditions lead to smaller critical Rayleigh number Rac, but larger convective wavelength and oscillation frequency ωc, compared with those with no-slip boundary conditions. Our numerical modelling results demonstrate that Rac and ωc predicted from the classical marginal stability analyses using Tbg(z) with TBL temperature may have significant errors when the oscillatory period is comparable with or larger than the timescale of lithospheric thermal diffusion that causes Tbg(z) to vary with time significantly. In this case, using a more gently sloped background temperature profile ignoring the TBL temperature, the stability analysis predicts more accurate stability conditions, thus presenting an effective remedy to the stability analysis. For plume-forming instability, because of the reduced viscosity in the hot and compositionally dense bottom layer, the transition to the layered convection occurs at significantly smaller B values, and in the oscillatory convection regime, Rac is larger but ωc is smaller, compared with those for lithospheric instability. Finally, our study provides a successful benchmark of numerical models of thermochemical convection by comparing Rac and ωc from numerical models with those from the marginal stability analysis.