We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Optimal nutrition supply to the developing foetus is paramount in achieving appropriate foetal growth and development. The Australian dietary guidelines advise about the amounts and types of foods for pregnancy(1). However, previous studies in reproductive aged women(2) and in pregnant women(3) showed suboptimal adherence to dietary recommendations. There is no evidence on the experience of sourcing nor uptake of the dietary guidelines among pregnant women. The aim of this study is to qualitatively explore women’s knowledge and understanding of nutrition information for pregnancy, including the current Australian dietary guidelines for pregnancy. Twelve pregnant women were recruited from a longitudinal study from the first through third trimester of pregnancy. Purposive sampling was adopted with an intention to recruit for diverse health information seeking habits. Semi-structured interviews were conducted with women at different trimesters, transcribed verbatim, and analysed thematically. Three themes were generated regarding information sourcing, uptake and evaluation. (i) Women had limited knowledge about the pregnancy dietary guidelines, leaving them to source pregnancy related nutrition information elsewhere. (ii) Women described other healthy eating advice that contributed to confusion and potential incompatibility with their dietary beliefs and lifestyle practices. (iii) Women shared that they were capable of seeking and evaluating the identified dietary advice, but the inconsistency across information sources contributed to over-cautious behaviour and dietary restrictions. Our findings suggest there is a general lack of awareness of the official dietary guidelines for pregnancy. To optimise pregnancy nutritional intake, efforts should be made to increase utilisation of the Australian dietary guidelines for pregnancy and to support uptake of dietary advice among pregnant women.
We examine a variant of ultimatum bargaining in which principals may delegate their proposal decision to agents hired from a competitive market. Contrary to several prior studies, we find that when principals must use agents, the resulting proposals are significantly higher than when principals make proposals themselves. In reconciling our results with prior findings, we conclude that both the rejection power afforded to responders and the structure of principal-agent contracts can play significant roles in the nature of outcomes under delegated bargaining.
People of Chinese ethnicity develop type 2 diabetes mellitus (T2DM) at a younger age and lower body mass index (BMI) than their Caucasian counterparts. Furthermore, Chinese migrants to Westernised countries have an increased risk of metabolic diseases compared to those in their country of origin(1,2). We propose that this increased risk is due to a greater manifestation of metabolic abnormalities in response to altered diet and lifestyle behaviours. Although fasting lipaemia and glycaemia are commonly used to predict risk of CVD and T2DM, assessment of impaired postprandial metabolism has been found to be a more sensitive indicator of risk(3). We hypothesised that Chinese migrants, at risk of T2DM, exhibit impaired postprandial lipid and lipoprotein metabolism compared to Australian-born Caucasian counterparts. Chinese and Caucasian adults at risk of T2DM were recruited to the study in which postprandial lipaemia and glycaemia were monitored following consumption of a high fat and high carbohydrate breakfast meal followed by a mixed, lunch meal. In a nonrandomised acute crossover trial, 15 adults (n = 8 Chinese and n = 7 Caucasian) aged ≥ 18 and ≤ 65 years at risk of T2DM (AUSDRISK score > 12 (median = 14.0, IQR = 3.0)), attended two postprandial test days separated by ≥ 7-day washout period. Test breakfast meals were isocaloric (3.6 MJ), high fat (46% energy from fat, 46% energy from carbohydrates) or high carbohydrate (74% E carbohydrates, 17.5% E fat). Blood samples were collected at baseline (fasting), 180 min and 360 min after consumption of the breakfast meal. The lunch meal (3.7 MJ, 18% E fat, 76% E carbohydrates) was consumed 240 min after baseline. Samples were analysed for lipaemia and glycaemia. Additionally, chylomicron-rich, and VLDL-rich lipoprotein fractions were isolated by sequential ultracentrifugation and chylomicron particle number (apolipoprotein (apo) B48), triacylglycerol (TAG), and total cholesterol were assessed in these fractions. Data were analysed using a mixed between-within-subject analysis of variance. There were no differences in age, and baseline anthropometric measures between groups, apart from the Chinese group exhibiting significantly lower waist circumference and BMI compared to the Caucasian group. There were no differences between groups in blood measures, apart from a higher total- and LDL-cholesterol concentration in the Caucasian compared to the Chinese group (P<0.05). Despite identical fasting TAG concentrations, the Chinese group, compared with the Caucasian group exhibited significantly elevated serum TAG and chylomicron-apo-B48 concentrations at 360 min following both test meals (P<0.01). All other postprandial measures were not different between groups. These findings show that despite having identical or improved fasting glycaemia and lipid profile, the Chinese group exhibited impaired postprandial lipid metabolism which may contributes to their increased risk of metabolic diseases.
Observer rating scales are necessary to evaluate the risk of suicide because individuals at risk for suicide are often unwilling to seek help on their own. Reliability and validity were evaluated for the newly developed Suicide Screening Questionnaire-Observer Rating (SSQ-OR).
Methods:
Preliminary items were assessed by 251 experts online and 25 questions were selected. 328 individuals at high-risk and 661 controls from 12 Crisis Response Centers and 5 university counseling centers were recruited to complete SSQ-OR, Beck Scale for Suicide Ideation (BSSI) and Patient Health Questionnaire-9 (PHQ-9). In a 6 months follow-up, we reached out to 176 participants to ask whether they had experienced a suicidal thought, plan, or attempt since the baseline assessment. Cronbach's 慣, Mann-Whitney U test, Spearman's correlation, factor analyses, Receiver operating characteristic (ROC) analysis and logistic regression analysis were used to verify the SSQ-OR.
Results:
Structural validity was supported by a two-factor solution using exploratory and confirmatory factor analyses. Excellent model fit indices for the two-factor structure using exploratory factor analysis were confirmed (RMSEA = 0.033, TLI = 0.980, CFI = 0.983). The SSQ-OR demonstrated strong internal consistency. The concurrent validity based on the correlations with other self-reported indicators of suicidal potential-BSSI and PHQ-9- revealed substantial relationships. The high-risk group was effectively characterized by a cut-off point of 4, with a sensitivity of 0.73 and a specificity of 0.79. The SSQ-OR scores were significant predictors of suicidal thoughts and behaviors within 6 months.
Conclusions:
The SSQ-OR exhibits sound psychometric properties, and could be used as a complement to a self-report or clinical-administered scale to screen suicide risk comprehensively.
The focus on social determinants of health (SDOH) and their impact on health outcomes is evident in U.S. federal actions by Centers for Medicare & Medicaid Services and Office of National Coordinator for Health Information Technology. The disproportionate impact of COVID-19 on minorities and communities of color heightened awareness of health inequities and the need for more robust SDOH data collection. Four Clinical and Translational Science Award (CTSA) hubs comprising the Texas Regional CTSA Consortium (TRCC) undertook an inventory to understand what contextual-level SDOH datasets are offered centrally and which individual-level SDOH are collected in structured fields in each electronic health record (EHR) system potentially for all patients.
Methods:
Hub teams identified American Community Survey (ACS) datasets available via their enterprise data warehouses for research. Each hub’s EHR analyst team identified structured fields available in their EHR for SDOH using a collection instrument based on a 2021 PCORnet survey and conducted an SDOH field completion rate analysis.
Results:
One hub offered ACS datasets centrally. All hubs collected eleven SDOH elements in structured EHR fields. Two collected Homeless and Veteran statuses. Completeness at four hubs was 80%–98%: Ethnicity, Race; < 10%: Education, Financial Strain, Food Insecurity, Housing Security/Stability, Interpersonal Violence, Social Isolation, Stress, Transportation.
Conclusion:
Completeness levels for SDOH data in EHR at TRCC hubs varied and were low for most measures. Multiple system-level discussions may be necessary to increase standardized SDOH EHR-based data collection and harmonization to drive effective value-based care, health disparities research, translational interventions, and evidence-based policy.
Over a quarter of U.S. children have at least one immigrant parent. Mental health disparities in children need to be assessed to better identify disproportionate burdens and promote health equity.
Objectives
To assess the associations between race, ethnicity, and parent-child nativity, and mental health conditions in the U.S.
Methods
Data were from the 2016-2019 National Survey of Children’s Health (n=114,476 children aged 3-17 years), a nationwide, cross-sectional survey. Outcome variables included three mental health conditions (depression, anxiety, and behavior or conduct problems) reported by the parent/guardian. Additional measures included questions about healthcare access and use, demographics, and nine household challenge adverse childhood experiences (ACEs) used to quantify a total ACE score (0-9). Information on nativity was used to define immigrant generation (1st, 2nd, and 3rd+). Weighted logistic regression was used to assess the associations between race/ethnicity (Asian, Black, Hispanic, White, and Other), household generation, and outcome variables, among children who reported access to or utilized health services, adjusting for demographics. Multiple imputation was used to handle missing data.
Results
Asian, Black, Hispanic, and White 3rd+ generation children had increased odds of depression compared to their 1st generation counterparts, same as among White, 2nd generation children. Race/ethnicity was not associated with depression among 1st and 3rd+ generation children, but Asian, Black, and Hispanic children had lower odds of depression compared to White children among 2nd generation children. Asian, Black, Hispanic, and Other-race 3rd+ generation children had increased odds of anxiety compared to their 1st generation counterparts, with similar findings also observed for Black and Other-race 2nd generation children. Being racial/ethnic minorities was generally associated with decreased odds of anxiety among 1st and 2nd generation children compared to White children from the respective generations. Asian, Black, Hispanic, and Other-race 3rd+ generation children had increased odds of behavior/conduct problems compared to their 1st generation counterparts. The observed associations remained significant after adjusting for the modified ACE score.
Conclusions
We found significant differences in several mental health conditions in children by parent-child nativity, race, and ethnicity that could not be explained by demographics, childhood adversity, and healthcare access and use. Lower odds of mental health conditions among minority children could represent differences due to factors such as differential reporting, and higher odds of mental health conditions, including in third- and higher generation children, need further investigation to develop approaches to promote mental health equity.
Depression and anxiety are common and highly comorbid, and their comorbidity is associated with poorer outcomes posing clinical and public health concerns. We evaluated the polygenic contribution to comorbid depression and anxiety, and to each in isolation.
Methods
Diagnostic codes were extracted from electronic health records for four biobanks [N = 177 865 including 138 632 European (77.9%), 25 612 African (14.4%), and 13 621 Hispanic (7.7%) ancestry participants]. The outcome was a four-level variable representing the depression/anxiety diagnosis group: neither, depression-only, anxiety-only, and comorbid. Multinomial regression was used to test for association of depression and anxiety polygenic risk scores (PRSs) with the outcome while adjusting for principal components of ancestry.
Results
In total, 132 960 patients had neither diagnosis (74.8%), 16 092 depression-only (9.0%), 13 098 anxiety-only (7.4%), and 16 584 comorbid (9.3%). In the European meta-analysis across biobanks, both PRSs were higher in each diagnosis group compared to controls. Notably, depression-PRS (OR 1.20 per s.d. increase in PRS; 95% CI 1.18–1.23) and anxiety-PRS (OR 1.07; 95% CI 1.05–1.09) had the largest effect when the comorbid group was compared with controls. Furthermore, the depression-PRS was significantly higher in the comorbid group than the depression-only group (OR 1.09; 95% CI 1.06–1.12) and the anxiety-only group (OR 1.15; 95% CI 1.11–1.19) and was significantly higher in the depression-only group than the anxiety-only group (OR 1.06; 95% CI 1.02–1.09), showing a genetic risk gradient across the conditions and the comorbidity.
Conclusions
This study suggests that depression and anxiety have partially independent genetic liabilities and the genetic vulnerabilities to depression and anxiety make distinct contributions to comorbid depression and anxiety.
This study primarily assessed ENT surgical trainees’ preferences for the qualities of disposable and reusable fibre-optic nasendoscopes. Secondary aims included eliciting trainees’ views on ENT surgery and climate change, and creating a single-centre per-use cost analysis for disposable and reusable fibre-optic nasendoscopes.
Methods
A cross-sectional study was formulated. An online survey consisting of multiple-choice and Likert-scale questions was distributed nationally. Cost analysis was performed using 2021–2022 data from the host institution.
Results
Twenty-four trainees responded. Data on disposable fibre-optic nasendoscopes showed no difference in overall satisfaction (p = 0.244). Reusable fibre-optic nasendoscopes had a lower cost per use compared with disposable nasendoscopes at 5 years (4.7 per cent reduction) and 10 years (7.1 per cent reduction). Of the trainees, 79.2 per cent were supportive of climate-friendly initiatives within ENT surgery, and 25 per cent felt supported by their departments.
Conclusion
Trainees’ satisfaction with disposable and reusable fibre-optic nasendoscopes is similar. Cost analysis favours reusable fibre-optic nasendoscopes in the long term at the host institution. Empowering departments and trainees to pursue climate-friendly initiatives should be encouraged.
The building of online atomic and molecular databases for astrophysics and for other research fields started with the beginning of the internet. These databases have encompassed different forms: databases of individual research groups exposing their own data, databases providing collected data from the refereed literature, databases providing evaluated compilations, databases providing repositories for individuals to deposit their data, and so on. They were, and are, the replacement for literature compilations with the goal of providing more complete and in particular easily accessible data services to the users communities. Such initiatives involve not only scientific work on the data, but also the characterization of data, which comes with the “standardization” of metadata and of the relations between metadata, as recently developed in different communities. This contribution aims at providing a representative overview of the atomic and molecular databases ecosystem, which is available to the astrophysical community and addresses different issues linked to the use and management of data and databases. The information provided in this paper is related to the keynote lecture “Atomic and Molecular Databases: Open Science for better science and a sustainable world” whose slides can be found at DOI : doi.org/10.5281/zenodo.6979352 on the Zenodo repository connected to the “cb5-labastro” Zenodo Community (https://zenodo.org/communities/cb5-labastro).
This study aimed to assess the effectiveness of an ENT simulation course for equipping foundation doctors with core ENT skills in preparation for an ENT senior house officer post.
Method
A total of 41 foundation doctors in the East of England participated in our two-part simulation course. Pre- and post-course surveys, consisting of Likert scales and a Dundee Ready Educational Environment Measure, were sent to assess confidence in core ENT skills and acceptability of course format.
Results
Post-simulation, confidence improved in all core ENT skills taught (p < 0.001), along with confidence and preparedness to work as an ENT senior house officer (p < 0.001). Overall course median Dundee Ready Educational Environment Measure score was 48, and 100 per cent of participants would recommend this course to colleagues.
Conclusion
Simulation improves foundation doctors’ confidence in core ENT skills and increases preparedness for working as an ENT senior house officer. Guidance on core ENT skills requirements should be made available to improve uniformity amongst ENT simulation courses.
Opposition control of artificially initiated turbulent spots in a laminar boundary layer was carried out in a low-turbulence wind tunnel with the aim to delay transition to turbulence by modifying the turbulent structure within the turbulent spots. The timing and duration of control, which was carried out using wall-normal jets from a spanwise slot, were pre-determined based on the baseline measurements of the transitional boundary layer. The results indicated that the high-speed region of the turbulent spots was cancelled by opposition control, which was replaced by a carpet of low-speed fluid. The application of the variable-interval time-averaging technique on the velocity fluctuation signals demonstrated a reduction in both the burst duration and intensity within the turbulent spots, but the burst frequency was increased.
OBJECTIVES/GOALS: The host immune response during sepsis is now recognized to have anti-inflammatory pathophysiology. We aim to determine whether mitochondrial dysfunction of leukocytes predicts which critically ill septic patients develop immune paralysis and to identify differences in cellular metabolites between patients with and without immune paralysis. METHODS/STUDY POPULATION: Critically ill septic and control adult patients were recruited from one of 6 ICUs in a single-center tertiary care academic hospital. After enrollment, peripheral blood mononuclear cells (PBMCs) were isolated from a tube of whole blood on day 0-1 after ICU admission. Flow cytometry to quantify monocyte HLA-DR was performed to determine whether patients were immune paralyzed or not. Mitochondrial functional assays of PBMCs were performed with inhibitors of the electron transport chain to assess for differences in oxidative phosphorylation and glycolysis utilization. Metabolic profiling of cell pellets was performed to evaluate for specific metabolites and pathways associated with immune paralyzed patients. RESULTS/ANTICIPATED RESULTS: A total of 101 patients were recruited, including 62 control and 39 septic patients. 81 patients had immune paralysis status available for analysis. 52% of all recruited subjects were immune paralyzed. Of these, 58% were controls and 75% were septic. Immune paralyzed septic and control patients showed features of reduced utilization of oxidative phosphorylation (ox phos) including reduced basal respiration, ATP production and maximal respiration compared with non-immune paralyzed septic and control patients. Immune paralyzed septic patients showed diminished glycolysis utilization compared with septic non-immune paralyzed patients. Finally, cellular kynurenine and quinolinate levels were low in both immune paralyzed control and septic patients compared with non-immune paralyzed patients. DISCUSSION/SIGNIFICANCE: The PBMCs of immune paralyzed septic patients show evidence of mitochondrial dysfunction, with reduced ox phos and glycolysis utilization. Low levels of kynurenine and quinolinate, metabolite precursors to NAD+, in immune paralyzed patients may signal key deficiencies and targetable therapeutic avenues for reversal of an immune paralyzed state.
Background: Phase 3 COMET trial (NCT02782741) compares avalglucosidase alfa (n=51) with alglucosidase alfa (n=49) in treatment-naïve LOPD. Methods: Primary objective: determine avalglucosidase alfa effect on respiratory muscle function. Secondary/other objectives include: avalglucosidase alfa effect on functional endurance, inspiratory/expiratory muscle strength, lower/upper extremity muscle strength, motor function, health-related quality of life, safety. Results: At Week 49, change (LSmean±SE) from baseline in upright forced vital capacity %predicted was greater with avalglucosidase alfa (2.89%±0.88%) versus alglucosidase alfa (0.46%±0.93%)(absolute difference+2.43%). The primary objective, achieving statistical non-inferiority (p=0.0074), was met. Superiority testing was borderline significant (p=0.0626). Week 49 change from baseline in 6-minute walk test was 30.01-meters greater for avalglucosidase alfa (32.21±9.93m) versus alglucosidase alfa (2.19±10.40m). Positive results for avalglucosidase alfa were seen for all secondary/other efficacy endpoints. Treatment-emergent adverse events (AEs) occurred in 86.3% of avalglucosidase alfa-treated and 91.8% of alglucosidase alfa-treated participants. Five participants withdrew, 4 for AEs, all on alglucosidase alfa. Serious AEs occurred in 8 avalglucosidase alfa-treated and 12 alglucosidase alfa-treated participants. IgG antidrug antibody responses were similar in both. High titers and neutralizing antibodies were more common for alglucosidase alfa. Conclusions: Results demonstrate improvements in clinically meaningful outcome measures and a more favorable safety profile with avalglucosidase alfa versus alglucosidase alfa. Funding: Sanofi Genzyme
The success of any clinical research team is dependent on hiring individuals with the experience and skill set needed for a specific research project. Strategies to improve the ability of human resource (HR) recruiters to screen and advance qualified candidates for a project will result in improved initiation and execution of the project.
Objective/Goals:
HR recruiters play a critical role in matching research applicants to the posted job descriptions and presenting a list of top candidates to the PI/hiring manager for interview and hiring consideration.
Methods/Study Population:
Creating guidelines to screen for applicant qualification based on resumes when clinical research positions have multiple levels of expertise required is a complex process of discovery, moving from subjective rationale for rating individual resumes to a more structured less biased evaluation process. To improve the hiring process of the research workforce, we successfully developed guidelines for categorizing research coordinator applications by level from beginner to advanced.
Results/Anticipated Results:
Through guideline development, we provide a framework to reduce bias and improve the matching of applicant resumes to job levels for improved selection of top candidates to advance for interviewing. Improved applicant to job matching offers an advantage to reduce hiring time, anticipate training needs, and shorten the timeline to active project engagement. These guidelines can form the basis for initial screening and ultimately matching individual qualities to project-specific needs.
Sedentary behaviour is potentially a modifiable risk factor for depression and anxiety disorders, but findings have been inconsistent.
Objectives
To assess associations of sedentary behavior with depression and anxiety symptoms and estimate the impact of replacing daily time spent in sedentary behaviors with sleep, light, or moderate-to-vigorous physical activity, using novel compositional data analysis methods.
Methods
Prospective cohort study in with 60,235 UK Biobank participants (mean age: 56; 56% female). Exposure was baseline daily movement behaviours (accelerometer-assessed sedentary behaviour, physical activity, and self-reported total sleep). Outcomes were depression and anxiety symptoms (Patient Health Questionnaire-9 and Generalised Anxiety Disorders-7) at follow up.
Results
Replacing 60 minutes of sedentary behaviour with light activity, moderate-to-vigorous activity, and sleep was associated with lower depression symptom scores by 1·3% (95%CI, 0·4%-2·1%), 12·5% (95%CI, 11·4%-13·5%), and 7·6% (95%CI, 6·9%-8·4%), and lower odds of depression by 0·95 (95%CI, 0·94-0·96), 0·75 (95%CI, 0·74-0·76), and 0·90 (95%CI, 0·90-0·91) at follow-up. Replacing 60 minutes of sedentary behaviour with moderate-to-vigorous activity and sleep was associated with lower anxiety symptom scores by 6·6% (95%CI, 5·5%-7·6%) and 4·5% (95%CI, 3·7%-5·2%), and lower odds of meeting the threshold for an anxiety disorder by 0·90 (95%CI, 0·89-0·90) and 0·97 (95%CI, 0·96-0·97) at follow-up. However, replacing 60 minutes of sedentary behaviour with light activity was associated with higher anxiety symptom scores by 4·5% (95%CI, 3·7%-5·3%) and higher odds of an anxiety disorder by 1·07 (95%CI, 1·06-1·08).
Conclusions
Sedentary behaviour is a risk factor for increased depression and anxiety symptoms in adults, but different replacement activities differentially influence mental health.
Opium tincture (OT) is widely used for opioid substitution treatment (OST) in Iran.
Objectives
To determine if OT is a safe and effective medication for OST.
Methods
Opium Trial was a multicenter, double‐blind, noninferiority randomized controlled trial, with 204 participants with opioid dependence in Iran. Participants were then randomized to OT or methadone arms with an allocation ratio of 1:1 and were followed for 12 weeks. The primary outcome was retention in treatment, compared between the two groups using both intention-To-Treat (ITT) and Per-Protocol (PP) analyses.
Results
A total of 70 participants (IT: 68.6%, PP: 69.3%) in methadone arm and 61 participants (ITT: 59.8%, PP: 60.4%) in OT arm remained in the treatment. The relative retention rate was 1.15 (0.97, 1.36) in both analyses in favour of methadone. A total of 46 out of 152 (30.3%) participants in OT arm and 83 out of 168 (49.4%) participants in methadone arm reported opioid use outside the treatment. The difference in these two proportions (OT - methadone) was 19%: (10%, 28%) in favour of OT. The proportion of patients with adverse events were not different between the two arms (P = 0.06). There was no serious AE in OT arm.
Conclusions
Opium tincture is a clinically effective and safe medication, but this study could not conclude if it was as equally effective as methadone in retaining participants in treatment, but it showed that OT was superior to methadone in reducing opioid use outside the treatment.
This study aimed to analyse if there were any associations between patulous Eustachian tube occurrence and climatic factors and seasonality.
Methods
The correlation between the monthly average number of patients diagnosed with patulous Eustachian tube and climatic factors in Seoul, Korea, from January 2010 to December 2016, was statistically analysed using national data sets.
Results
The relative risk for patulous Eustachian tube occurrence according to season was significantly higher in summer and autumn, and lower in winter than in spring (relative risk (95 per cent confidence interval): 1.334 (1.267–1.404), 1.219 (1.157–1.285) and 0.889 (0.840–0.941) for summer, autumn and winter, respectively). Temperature, atmospheric pressure and relative humidity had a moderate positive (r = 0.648), negative (r = –0.601) and positive (r = 0.492) correlation with the number of patulous Eustachian tube cases, respectively.
Conclusion
The number of patulous Eustachian tube cases was highest in summer and increased in proportion to changes in temperature and humidity, which could be due to physiological changes caused by climatic factors or diet trends.
An experimental investigation was carried out in a low-turbulence wind tunnel to study the early development of artificially initiated turbulent spots in a laminar boundary layer over a flat plate. The reproducibility of the experiments allowed us to observe fine structural details that have not been observed previously. Initial velocity disturbances quickly developed into hairpin-like structures that multiplied downstream, which increased the width, length and height of the incipient turbulent spots. Only those disturbances that were greater than a threshold value developed into turbulent spots while the others decayed. The rate of development was also affected by the duration of the initial disturbances. We found that the behaviour of turbulence generation within a turbulent spot is similar to the burst events in the turbulent boundary layer, where ejection events are followed by sweep events.