Transfer of microorganisms from dry surface biofilms and the influence of long survival under conditions of poor nutrition and moisture on the virulence of Staphylococcus aureus.

BACKGROUND: Biofilms on dry hospital surfaces can enhance the persistence of microorganisms on dry harsh clinical surfaces and can potentially act as reservoirs of infectious agents on contaminated surfaces. AIM: This study was conducted to quantify the transfer of viable Staphylococcus aureus cells from dry biofilms through touching and to investigate the impact of nutrient and moisture deprivation on virulence levels in S. aureus. METHODS: Dry biofilms of S. aureus ATCC 25923 and a defective biofilm-forming ability mutant, S. aureus 1132 were formed in 24 well plates under optimised conditions mimicking dry biofilm formation on clinical surfaces. Microbial cell transfer was induced through the touching of the dry biofilms, which were quantified on nutrient agar. To investigate the impact of nutrient and moisture deprivation on virulence levels, dry and standard biofilms as well as planktonic cells of S. aureus ATCC 25923 were inoculated into Galleria mellonella and their kill rates compared. FINDINGS & CONCLUSION: Results of this study showed that viable cells from dry biofilms of S. aureus ATCC 25923 were significantly more virulent and readily transferrable from dry biofilms through a touch test, therefore representing a greater risk of infection. The biofilm-forming capability of S. aureus strains had no significant impact on their transferability with more cells transferring when biofilm surfaces were wet. These findings indicate that dry biofilms on hospital surfaces may serve as a reservoir for the dissemination of pathogenic microorganisms in hospitals, thus highlighting the importance of regular cleaning and adequate disinfection of hospital surfaces.

Problems most concerning to parents of children with ADHD and emotional dysregulation in a randomized controlled trial of multinutrients: MADDY secondary analysis.

OBJECTIVE: With dual focus on structured, objective quantification of parent observations of child's behavior and identifying behaviors most amenable to change, this report examines Parent Target Problems (PTP) as a secondary outcome in a randomized clinical trial (RCT) of children with attention-deficit/ hyperactivity disorder (ADHD) in which one primary outcome, Clinical Global Impression-Improvement, showed a significant advantage of multinutrients over placebo and the other, Likert-type parent ratings, showed significant improvement in both groups, without significant difference between them. METHOD: In a multisite 8-week RCT of broad-spectrum micronutrients ("multinutrients"), parents of children ages 6-12 (N = 126, 73% male, 88% white) with ADHD and emotional dysregulation nominated their child's most concerning problem(s) at baseline and quantified them by frequency, duration, impairment, and consequences. At subsequent visits, parents re-quantified the problem(s). Blinded child psychiatrists independently reviewed the PTPs and rated change at two timepoints compared to baseline. PTPs were grouped into 9 categories. Mean ratings were compared between active and placebo groups and explored by category. RESULTS: By week 8, a significant separation favored multinutrients: 38% of the multinutrient group were "definitely improved" or better, compared to 25% of the placebo group, and ratings of "no change" or "worse" occurred in 35% with placebo versus 23% with multinutrients (p = 0.04). Inattention (72.2%) and emotional dysregulation (69.1%) were the most frequently reported PTP categories. Inattention and internalizing symptoms improved more with multinutrients than placebo (p = 0.01, d = 0.55; p = 0.03, d = 0.80, respectively). The multinutrient advantage was not significant for 7 other symptoms, including hyperactivity/impulsivity, aggression, autistic symptoms, or emotional dysregulation/irritable oppositionality. CONCLUSIONS: This secondary analysis found that the multinutrients, compared to placebo, were associated with improvements in parental concerns overall, and in two domains specifically: inattention and internalizing symptoms (anxiety/depression), but not in seven domains: hyperactivity/impulsivity, aggression, autistic symptoms or physiological symptoms, peer relationships or emotional dysregulation/irritable oppositionality.

Adapting, restarting, and terminating a randomised control trial for people with cystic fibrosis: Reflections on the impact of the COVID-19 pandemic upon research in a clinical population.

Background: Habitual physical activity (PA) and exercise form a cornerstone of the management of cystic fibrosis (CF), a genetically inherited pulmonary and digestive condition - whereby telehealth platforms have been proposed as a mechanism to engage remotely people with CF in PA and exercise. Methods: To test this, in early 2020, the 'ActivOnline: Physical Activity in Cystic Fibrosis Trial' (ActiOn PACT) randomised control trial was established to examine whether an online intervention was effective at increasing PA in adolescents and adults with CF. Results: The emergence of the COVID-19 pandemic in 2020 forced this trial to be paused and modified, with the adoption of online recruitment and remote assessment of outcome measures. Despite such adaptations in accord with frameworks developed by the National Institute for Health Research, this trial failed to recruit and was subsequently terminated. Conclusions: This article details the authors reflections upon the proposed reasons for lack of recruitment, including improved technology and medications for people with CF, and contextualises this finding in relation to the wider issue of non-reporting of trial results in clinical research.

Macrocyclic Copper(II) Complexes as Catalysts for Electrochemically Mediated Atom Transfer.

Copper-catalyzed electrochemical atom transfer radical addition (eATRA) is a new method for the creation of new C-C bonds under mild conditions. In this work, we have explored the reactivity of an analogous series of N4 macrocyclic CuII complexes as eATRA precatalysts, which are primed by reduction to their monovalent oxidation state. These complexes were fully characterized structurally, spectroscopically, and electrochemically. A spectrum of radical activation reactivity was found across the series [CuI(Me4cyclen)(NCMe)]+ (Me4cyclen = 1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane), [CuI(Me4cyclam)(NCMe)]+ (Me4cyclam = 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane), and [CuI(Me2py2clen)(NCMe)]+ (Me2py2clen = 3,7-dimethyl-3,7-diaza-1,5(2,6)-dipyridinacyclo-octaphane). The rate of radical production by [Cu(Me2py2clen)(NCMe)]+ was modest, but rapid radical capture to form the organocopper complex [CuI(Me2py2clen)(CH2CN)] led to a dramatic acceleration in catalysis, greater than seen in any comparable Cu complex, but this led to rapid radical self-termination instead of radical addition.

Numerical computation of temperature on steel and an insulator with simulation compared to experimental data.

In this report, we are computing the temperature from the heat equation for a disk of a given thickness. A laser beam of Gaussian profile is assumed at the surface of a circular sample. Prediction of temperature for a laser pulse with a Gaussian profile is shown for a circular symmetry. Temperature distributions are performed analytically and numerically for a power with a Gaussian profile at different depths from the surface. In the previous computation the laser beam was assumed to be small compared to the disk's radius. The calculations performed are useful to predict the proper spacing between marks during a laser procedure. Computations of the temperature for a beam spot size much larger than the sample dimensions are also shown for a modulated laser beam. The computation of temperature for the modulated laser beam is also compared to experimental data points obtained on bone.

Machine learning identifies cell-free DNA 5-hydroxymethylation biomarkers that detect occult colorectal cancer in PLCO Screening Trial subjects.

Background: Colorectal cancer (CRC) is a leading cause of cancer-related mortality, and CRC detection through screening improves survival rates. A promising avenue to improve patient screening compliance is the development of minimally-invasive liquid biopsy assays that target CRC biomarkers on circulating cell-free DNA (cfDNA) in peripheral plasma. In this report, we identify cfDNA biomarker candidate genes bearing the epigenetic mark 5-hydroxymethylcytosine (5hmC) that diagnose occult CRC up to 36 months prior to clinical diagnosis using the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial samples. Methods: Archived PLCO Trial plasma samples containing cfDNA were obtained from the National Cancer Institute (NCI) biorepositories. Study subjects included those who were diagnosed with CRC within 36 months of blood collection (i.e., case, n = 201) and those who were not diagnosed with any cancer during an average of 16.3 years of follow-up (i.e., controls, n = 402). Following the extraction of 3 - 8 ng cfDNA from less than 300 microliters plasma, we employed the sensitive 5hmC-Seal chemical labeling approach, followed by next-generation sequencing (NGS). We then conducted association studies and machine-learning modeling to analyze the genome-wide 5hmC profiles within training and validation groups that were randomly selected at a 2:1 ratio. Results: Despite the technical challenges associated with the PLCO samples (e.g., limited plasma volumes, low cfDNA amounts, and long archival times), robust genome-wide 5hmC profiles were successfully obtained from these samples. Association analyses using the Cox proportional hazards models suggested several epigenetic pathways relevant to CRC development distinguishing cases from controls. A weighted Cox model, comprised of 32-associated gene bodies, showed predictive detection value for CRC as early as 24-36 months prior to overt tumor presentation, and a trend for increased predictive power was observed for blood samples collected closer to CRC diagnosis. Notably, the 5hmC-based predictive model showed comparable performance regardless of sex and self-reported race/ethnicity, and significantly outperformed risk factors such as age and obesity according to BMI (body mass index). Additionally, further improvement of predictive performance was achieved by combining the 5hmC-based model and risk factors for CRC. Conclusions: An assay of 5hmC epigenetic signals on cfDNA revealed candidate biomarkers with the potential to predict CRC occurrence despite the absence of clinical symptoms or the availability of effective predictors. Developing a minimally-invasive clinical assay that detects 5hmC-modified biomarkers holds promise for improving early CRC detection and ultimately patient survival through higher compliance screening and earlier intervention. Future investigation to expand this strategy to prospectively collected samples is warranted.

Informed development of a multi-species biofilm in chronic obstructive pulmonary disease.

Recent evidence indicates that microbial biofilm aggregates inhabit the lungs of COPD patients and actively contribute towards chronic colonization and repeat infections. However, there are no contextually relevant complex biofilm models for COPD research. In this study, a meta-analysis of the lung microbiome in COPD was used to inform development of an optimized biofilm model composed of genera highly associated with COPD. Bioinformatic analysis showed that although diversity matrices of COPD microbiomes were similar to healthy controls, and internal compositions made it possible to accurately differentiate between these cohorts (AUC = 0.939). Genera that best defined these patients included Haemophilus, Moraxella and Streptococcus. Many studies fail to account for fungi; therefore, Candida albicans was included in the creation of an interkingdom biofilm model. These organisms formed a biofilm capable of tolerating high concentrations of antimicrobial therapies with no significant reductions in viability. However, combined therapies of antibiotics and an antifungal resulted in significant reductions in viable cells throughout the biofilm (p < 0.05). This biofilm model is representative of the COPD lung microbiome and results from in vitro antimicrobial challenge experiments indicate that targeting both bacteria and fungi in these interkingdom communities will be required for more positive clinical outcomes.

Process evaluation of school-based high-intensity interval training interventions for children and adolescents: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Several systematic reviews have been published to investigate the effectiveness of high-intensity interval training (HIIT) in schools. However, there has been limited attention given to understanding the functioning of the intervention processes, which is of paramount importance for interpreting and translating the intervention effectiveness. The aim of this systematic review is to determine the extent to which process evaluation is measured in school-based HIIT interventions and to explore the effects of process evaluation and intervention characteristics on cardiorespiratory fitness (CRF), body composition, muscular strength, and blood pressure. METHODS: A comprehensive search was conducted in SPORT Discus (EBSCOhost), Web of Science, Scopus, Medline (Ovid) and Cochrane Central Register of Controlled Trials. The extent to which process evaluation is measured was narratively reported, alongside with the guidance of process evaluation of complex interventions by UK Medical Research Council. Meta-analyses and meta-regressions were conducted to determine the effects of process evaluation and intervention characteristics to the intervention outcomes. RESULTS: The literature search identified 77 studies reporting on 45 school-based HIIT interventions. In total, five interventions reported process evaluation in a section or in a separate study, and only one intervention adopted a process evaluation framework. On average, 6 out of 12 process evaluation measures were reported in all interventions. Subgroup analyses did not indicate any beneficial treatment effects for studies with process evaluation group, whereas all pooled data and studies without process evaluation group showed significant improvement for CRF and body composition. CONCLUSION: Process evaluation is frequently omitted in the literature of school-based HIIT in children and adolescents. Although reporting of process evaluation measures may not directly associate with better intervention outcomes, it allows accurate interpretation of intervention outcomes, thereby enhancing the generalisability and dissemination of the interventions.

Testing the intrinsic mechanisms driving the dynamics of Ross River Virus across Australia.

The mechanisms driving dynamics of many epidemiologically important mosquito-borne pathogens are complex, involving combinations of vector and host factors (e.g., species composition and life-history traits), and factors associated with transmission and reporting. Understanding which intrinsic mechanisms contribute most to observed disease dynamics is important, yet often poorly understood. Ross River virus (RRV) is Australia's most important mosquito-borne disease, with variable transmission dynamics across geographic regions. We used deterministic ordinary differential equation models to test mechanisms driving RRV dynamics across major epidemic centers in Brisbane, Darwin, Mandurah, Mildura, Gippsland, Renmark, Murray Bridge, and Coorong. We considered models with up to two vector species (Aedes vigilax, Culex annulirostris, Aedes camptorhynchus, Culex globocoxitus), two reservoir hosts (macropods, possums), seasonal transmission effects, and transmission parameters. We fit models against long-term RRV surveillance data (1991-2017) and used Akaike Information Criterion to select important mechanisms. The combination of two vector species, two reservoir hosts, and seasonal transmission effects explained RRV dynamics best across sites. Estimated vector-human transmission rate (average ß = 8.04x10-4per vector per day) was similar despite different dynamics. Models estimate 43% underreporting of RRV infections. Findings enhance understanding of RRV transmission mechanisms, provide disease parameter estimates which can be used to guide future research into public health improvements and offer a basis to evaluate mitigation practices.

The (±)-5-Aza[1.0]triblattane Skeleton via Azetine Cycloaddition.

The first synthesis of the 5-aza[1.0]triblattane skeleton was achieved through a [4 + 2] cycloaddition approach using a suitably protected azetine and cyclopentadiene. A series of azetines were synthesized to explore both stability and suitable N-protection. The key step following cycloaddition utilized a noninitiated protonated aminyl radical cyclization to install the final 5-azatriblattane bond, but it was found to be considerably more unstable than the 6-aza isomer under acidic conditions.

Validation and Calibration for Embedding Rating of Perceived Exertion Into High-Intensity Interval Exercise in Adolescents: A Lab-Based Study.

PURPOSE: Rating of perceived exertion (RPE) is a convenient and cost-effective tool that can be used to monitor high-intensity interval exercise (HIIE). However, no methodological study has demonstrated the validity of RPE in this context. Therefore, the aim of this study was to validate and calibrate RPE for monitoring HIIE in adolescents. METHODS: RPE, heart rate (HR), and oxygen uptake (V˙O2) data were retrospectively extracted from 3 lab-based crossover studies, with a pooled sample size of 45 adolescents, performing either cycling-based or running-based HIIE sessions. Within-participant correlations were calculated for RPE-HR and RPE-V˙O2, and receiver operator characteristic curve analysis was used to establish RPE cut points. RESULTS: The results showed that RPE-HR demonstrated acceptable criterion validity (r = .53-.74, P < .01), while RPE-V˙O2 had poor validity (r = .40-.48, P < .01), except for HIIE at 100% peak power (r = .59, P < .01). RPE cut points of 4 and 5 were established in corresponding to HR/V˙O2 based thresholds. CONCLUSION: RPE has some utility in evaluating intensity during lab-based running or cycling HIIE in adolescents. Future studies should expand the validation and calibration of RPE for prescribing and monitoring HIIE in children and adolescents in field-based contexts.

The effect of the Mid-Day Meal programme on the longitudinal physical growth from childhood to adolescence in India.

The study aims to examine the effect of the world's largest school-feeding programme, the Mid-Day Meal (MDM) programme, on the changes in the underweight prevalence among school-children in India. Data from the Indian Human Development Survey (IHDS) Rounds 1 (2004-05) and 2 (2011-12) were utilized. The sample included individual-level information of children aged 6 to 9 years in IHDS-1 who then turned 13 to 16 years in IHDS-2. The sample was categorised into four groups based on their MDM consumption history (Group 1: no MDM support in IHDS-1 and IHDS-2, Group 2: MDM support in IHDS-1, Group 3: MDM support in IHDS-2, Group 4: persistent MDM support in IHDS-1 and IHDS-2). The dependent variable was underweight status as defined by the World Health Organisation Child Growth Standards Body Mass Index for age (BMI Z-score) < -2 SD of the median. Bivariate analysis was used to examine the prevalence of underweight and establish associations between underweight status and socio-demographic characteristics. Logistic regression was performed to assess the strength of the association of socio-demographic characteristics and MDM consumption patterns with underweight across poor and non-poor asset groups. The findings suggest that early and persistent MDM support among respondents reduced the likelihood of low BMI Z-scores compared to those without MDM support. Respondents from the poor asset group who received MDM support in at least one of the two survey rounds had higher odds of being underweight in comparison with those who did not receive MDM support at all. Girls and adolescents residing in the Eastern region of India were less likely to be underweight. The study shows that the MDM programme was effective in reducing the rate of underweight among school children. However, continuous programme upscaling with a special focus on children from poor households will significantly benefit India's school-aged children.

The Role of Speckle-Tracking Echocardiography in Predicting Mortality and Morbidity in Patients With Congenital Heart Disease: A Systematic Review and Meta-analysis.

BACKGROUND: Speckle-tracking echocardiography (STE) is now routinely included in cardiac evaluations, but its role in predicting mortality and morbidity in congenital heart disease (CHD) is not well described. We conducted a systematic review to evaluate the prognostic value of STE in patients with CHD. METHODS: The EMBASE, Medline, Web of Science, Scopus, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched from inception to January 2023 for terms related to all CHD, STE, and prognosis. Meta-analysis of association of right ventricle and left ventricle strain (RV Sl and LV Sl, respectively) with major adverse cardiovascular events (MACEs) was performed in atrial switch transposition of the great arteries (asTGA)/congenitally corrected TGA (ccTGA), tetralogy of Fallot (ToF), and congenital aortic stenosis (cAS)/bicuspid aortic valve (BAV). P-value combination analysis was additionally performed for all CHD groups. RESULTS: A total of 33 studies (30 cohorts, n = 8,619 patients, children, and adults) were included. Meta-analysis showed the following parameters as being associated with MACE: RV Sl in asTGA/ccTGA (hazard ratio [HR] = 1.1/%; CI, [1.03; 1.18]), RV Sl and LV Sl in ToF (HR = 1.14/%; CI, [1.03; 1.26] and HR = 1.14/%; CI, [1.08; 1.2], respectively), and LV Sl in cAS/BAV (HR = 1.19/%; CI, [1.15; 1.23]). The RV Sl and strain rate were associated with outcomes also in single ventricle/hypoplastic left heart syndrome (at all palliation stages except before Norwood stage 1) and LV Sl in Ebstein's anomaly. CONCLUSIONS: This systematic review and meta-analysis showed that biventricular strain and strain rate were associated with outcomes in a variety of CHD, highlighting the need for updated recommendations on the use of STE in the current guidelines, specific to disease types.

Parental recommendations and exercise attitudes in congenital hearts.

BACKGROUND: Children and young people with CHD benefit from regular physical activity. Parents are reported as facilitators and barriers to their children's physical activity. The aim of this study was to explore parental factors, child factors, and their clinical experience on physical activity participation in young people with CHD. METHODS: An online questionnaire was co-developed with parents (n = 3) who have children with CHD. The survey was then distributed in the United Kingdom by social media and CHD networks, between October 2021 and February 2022. Data were analysed using mixed methods. RESULTS: Eighty-three parents/guardians responded (94% mothers). Young people with CHD were 7.3 ± 5.0 years old (range 0-20 years; 53% female) and 84% performed activity. Parental participation in activity (X2(1) = 6.9, P < 0.05) and perceiving activity as important for their child were positively associated with activity (Fisher's Exact, P < 0.05). Some parents (∼15%) were unsure of the safety of activity, and most (∼70%) were unsure where to access further information about activity. Fifty-two parents (72%) had never received activity advice in clinic, and of the 20 who received advice, 10 said it was inconsistent. Qualitative analysis produced the theme "Knowledge is power and comfort." Parents described not knowing what activity was appropriate or the impact of it on their child. CONCLUSION: Parental participation and attitudes towards activity potentially influence their child's activity. A large proportion of young people performed activity despite a lack and inconsistency of activity advice offered by CHD clinics. Young people with CHD would benefit from activity advice with their families in clinics.

Cardiopulmonary Exercise Testing Provides Prognostic Information in Advanced Cystic Fibrosis Lung Disease.

Rationale: Cardiopulmonary exercise testing (CPET) provides prognostic information in cystic fibrosis (CF); however, its prognostic value for patients with advanced CF lung disease is unknown. Objectives: To determine the prognostic value of CPET on the risk of death or lung transplant (LTX) within 2 years. Methods: We retrospectively collected data from 20 CF centers in Asia, Australia, Europe, and North America on patients with a forced expiratory volume in 1 second (FEV1) ⩽ 40% predicted who performed a cycle ergometer CPET between January 2008 and December 2017. Time to death/LTX was analyzed using mixed Cox proportional hazards regression. Conditional inference trees were modeled to identify subgroups with increased risk of death/LTX. Results: In total, 174 patients (FEV1, 30.9% ± 5.8% predicted) were included. Forty-four patients (25.5%) died or underwent LTX. Cox regression analysis adjusted for age, sex, and FEV1 revealed percentage predicted peak oxygen uptake ([Formula: see text]o2peak) and peak work rate (Wpeak) as significant predictors of death/LTX: adjusted hazard ratios per each additional 10% predicted were 0.60 (95% confidence interval, 0.43-0.90; P = 0.008) and 0.60 (0.48-0.82; P < 0.001). Tree-structured regression models, including a set of 11 prognostic factors for survival, identified Wpeak to be most strongly associated with 2-year risk of death/LTX. Probability of death/LTX was 45.2% for those with a Wpeak ⩽ 49.2% predicted versus 10.9% for those with a Wpeak > 49.2% predicted (P < 0.001). Conclusions: CPET provides prognostic information in advanced CF lung disease, and Wpeak appears to be a promising marker for LTX referral and candidate selection.

9-Azahomocubane.

Homocubane, a highly strained cage hydrocarbon, contains two very different positions for the introduction of a nitrogen atom into the skeleton, e. g., a position 1 exchange results in a tertiary amine whereas position 9 yields a secondary amine. Herein reported is the synthesis of 9-azahomocubane along with associated structural characterization, physical property analysis and chemical reactivity. Not only is 9-azahomocubane readily synthesized, and found to be stable as predicted, the basicity of the secondary amine was observed to be significantly lower than the structurally related azabicyclo[2.2.1]heptane, although similar to 1-azahomocubane.

seco-1-Azacubane-2-carboxylic Acid: Derivative Scope and Comparative Biological Evaluation.

The unusual and sterically constrained amino acid, seco-1-azacubane-2-carboxylic acid, was incorporated into a range of bioactive chemical templates, including enalaprilat, perindoprilat, endomorphin-2 and isoniazid, and subjected to biological testing. The endomorphin-2 derivative displayed increased activity at the δ opioid receptor, but a loss in activity was observed in the other cases, although human normal cell line evaluation suggests limited cytotoxic effects.

The discovery of a data-driven causal diagram of sport participation in children and adolescents with heart disease: a pilot study.

The interventions aimed at improving the levels of physical activity (PA) in children and adolescents diagnosed with heart disease did not produce the expected outcomes. Safe participation in sport activities proposed based on actual recommendations could be a solution to promote PA in this population. The aims of this study were to discover a causal diagram of sport participation in children and youth with heart disease and establish the factors that affect and are affected thereof through the use of questionnaires. Furthermore, the study aims to qualitatively assess the reliability of the constructed diagram in comparison with existing medical knowledge. The Greedy Fast Causal Inference method was employed to conduct a data-driven search of the directed acyclic graph that represents the causal relationships within the provided observational data. This causal discovery was performed using the Tetrad software. The analysis involved a cohort of 121 Caucasian patients (50 females) diagnosed with heart disease. The age range of the patients included in the study was 8-17 years. The study findings indicate that the participants engaged in sports presented significantly higher values of health-related quality of life (QoL) and motives for participating in physical and leisure activities. Age appears to be a cause of sport participation. Sport participation appears to be a cause of participation in physical education classes, which in turn appears to be a cause of higher enjoyment. Higher enjoyment appears to be a cause of other motives for participating in physical and leisure activities, as well as a higher score in terms of physical health. The causal diagram provided a graphical representation of the causal relationship between sport participation and better QoL with potential confounders for children and adolescents with heart disease that nearly coincided with the existing literature. Clinical trials should be designed to validate clinical utility of the presented causal diagram.