Caffeine addiction and determinants of caffeine consumption among health care providers: a descriptive national study.

OBJECTIVE: Caffeine is the most commonly used psychostimulant compound with a long history of worldwide consumption. Consuming low to moderate doses of caffeine is generally safe and quite beneficial; however, several clinical studies show that high doses could be toxic.  Additionally, caffeine users can become dependent on the drug and find themselves unable to reduce consumption despite impending and recurrent health problems associated with continued use. This study was conducted to explore the prevalence, determinants, and positive and negative effects of caffeine consumption among governmental health care providers (HCPs) who were caffeine users. It aims to determine the frequency of caffeine dependence and addiction in the Kingdom of Saudi Arabia (KSA) in January 2020. SUBJECTS AND METHODS: This cross-sectional study recruited 600 randomly selected HCPs from all regions of KSA, who fulfilled the selection criteria through a self-administrated, online-validated questionnaire composed of three main parts using the DSM-IV to diagnose dependence and probable addiction. RESULTS: The majority of the studied HCPs were females (67.8%), nonsmokers (82.0%), and Saudis (80.5%), with a mean age of 35 years. According to the DSM-IV, the prevalence of caffeine consumption was 94.3%. Caffeine dependence was reported in 270 (47.7%), while 345 (60.9%) were diagnosed as addicts. The most commonly consumed caffeine-containing substances were coffee and its variants/types (70%), tea (59%), and chocolate (52%), with each person spending about 220 SR per week on them. The main reported adverse effects, in descending order, were sleep disturbances, stomach problems, and cardiac symptoms. The most positive effects reported of caffeine consumption were feeling active, alert, confident, and happy. These findings were significantly affected by sex, occupation, and general health. CONCLUSIONS: Caffeine use, dependence, and addiction are common among government HCPs in KSA. Caffeine has both positive and negative effects on this population and further research is necessary to better understand the long-term consequences of caffeine consumption.

Hybrid spiral-dynamic bacteria-chemotaxis algorithm with application to control two-wheeled machines.

This paper presents the implementation of the hybrid spiral-dynamic bacteria-chemotaxis (HSDBC) approach to control two different configurations of a two-wheeled vehicle. The HSDBC is a combination of bacterial chemotaxis used in bacterial forging algorithm (BFA) and the spiral-dynamic algorithm (SDA). BFA provides a good exploration strategy due to the chemotaxis approach. However, it endures an oscillation problem near the end of the search process when using a large step size. Conversely; for a small step size, it affords better exploitation and accuracy with slower convergence. SDA provides better stability when approaching an optimum point and has faster convergence speed. This may cause the search agents to get trapped into local optima which results in low accurate solution. HSDBC exploits the chemotactic strategy of BFA and fitness accuracy and convergence speed of SDA so as to overcome the problems associated with both the SDA and BFA algorithms alone. The HSDBC thus developed is evaluated in optimizing the performance and energy consumption of two highly nonlinear platforms, namely single and double inverted pendulum-like vehicles with an extended rod. Comparative results with BFA and SDA show that the proposed algorithm is able to result in better performance of the highly nonlinear systems.

Validation study of the s classification for melanoma patients with positive sentinel nodes: the Montreal experience.

BACKGROUND: Standard of care is to perform a complete lymph node dissection (CLND) in melanoma patients with positive sentinel lymph nodes (SLNs). However, less than 20% will have metastases in non-SLNs. The S classification was described to predict the non-SLN status, hoping to identify a subset of patients who can be spared the CLND. We tried to validate the feasibility and usefulness of this classification. MATERIALS AND METHODS: We performed a retrospective chart review. All melanoma cases between 1996 and 2006 were included, and 359 patients with SLN biopsies were identified. All pathology slides were reviewed with an emphasis on the S classification. RESULTS: There were 365 SLN biopsies performed. A total of 82 patients (22.8%) had positive SLNs, while 277 patients (77.2%) had negative SLNs. There were 22 patients classified as SI, 18 as SII, 37 as SIII, and 5 were unclassified. On CLND, only 10 patients (12.2%) had positive non-SLNs. None of these were classified as SI while 2 patients (11%) were classified as SII and 8 (22%) as SIII. The S category was found to be a predictor of non-SLN status, and this reached statistical significance (P = 0.044). On univariate analysis, only an increasing Breslow depth and ulceration were predictive of a non-SI status. CONCLUSION: Our results suggest that the S classification is easily feasible and predicts the status of non-SLNs. No patient with SI status was found to have additional non-SLN positive nodes. A larger-scale, prospective trial should be done to confirm these results and possibly spare patients the morbidity of CLND with a positive SLN.