Periodic polynomial regression analysis of urban driving characteristics

ArticleUrban driving characteristics with a focus on energy consumption have been tested in Riga on three main city streets with inflexible coordinated traffic lights control. The aim of this article is to investigate periodic polynomial regression analysis method to analyse car urban driving parameters’ change during weekday twenty-four hours to assess the influence of vehicle technologies on energy consumption in city driving, to map the energy demand on Riga city main street sections and to evaluate the traffic lights control on flow energetic characteristics. The tests have been done using GPS and OBD data loggers on a test car repetitively driven along a preplanned route at around-the-clock hours. A regression analysis using periodic polynomials was developed and applied to evaluate the traffic flow characteristics with a given time shift. It was concluded that using polynomial regression function, the polynomial order has to be at least seven although a visual conformation of good regression line to the measured data has to be checked especially with lower orders. To evaluate the traffic conditions at a given 20 minutes to one hour shift the application of regression function is limited for the periods with fast changing traffic flow, especially after the end of rush hours when the usability of regression line for the given data has to be checked individually for tested street sections

Valor de la Resonancia Nuclear Magnética en Ortopedia Oncológica

Presentamos nuestra experiencia preliminar sobre la utilidad diagnóstica de la Resonancia Nuclear Magnética (RM) en la evaluación pre- y postoperatoria de pacientes con tumores musculoesqueléticos. Se han revisado 21 pacientes con tumores caracterizados histológicamente. Del total, 10 casos eran sarcomas de partes blandas, 7 correspondían a tumores óseos y 4 eran metástasis óseas o recidivas locales. Las imágenes se obtuvieron mediante un sistema de RM de campo medio provisto de un imán superconductor operando a 0.5 Teslas. En todos los casos se obtuvieron imágenes T1 y T2, en los planos axial y coronal. Como norma se objetivó un excelente contraste entre la señal de la lesión y la de las estructuras normales adyacentes. Sólo en un caso, un osteosarcoma del extremo proximal del peroné, las imágenes de extensión a partes blandas vecinas resultaron ser negativas en la exploración quirúrgica. El análisis de los cambios de intensidad de la señal no permitieron distinguir la especificidad tisular del tumor, ni diferenciar lesiones benignas y malignas. En nuestra experiencia, la RM nos ha permitido un mejor diagnóstico anatómico de la extensión tumoral, facilitándonos la planificación quirúrgica que requieren las modernas técnicas reconstructivas en ortopedia oncológica.The preliminary experience using Magnetic Resonance imaging for pre- and post-operative assessment of orthopaedic oncologic patients is hereby reported. Twenty-one patients with histologically characterized bone and soft tissue tumors have been reviewed. Seventeen patients had primary musculoskeletal neoplasia: 10 had soft tissue sarcomas and 7 bone tumors. The remained 4 patients consisted of bone metastasis or local racidive. Magnetic resonance images were acquired using a superconductive magnet operating at 0.5 Tesla. T1- and T2-weighted transaxial and coronal images were obtained in all cases. An excellent contrast between the signal of the lesion and the normal adjacent structures was usually obtained. Only in one osteosarcoma of the proximal fibula, an extraosseous extension was presumed but not found during surgical resection. Changes in image intensity did not permit to identify tumor tissue specificity neither distinguish between benign and malignat lesions. In our experience, Magnetic Resonance shows a great advantage in order to determine tumor anatomical extension, providing a useful information for the surgical planning required by current reconstructive techniques in orthopaedic oncology

Self-injury in youths who lost a parent to cancer: nationwide study of the impact of family-related and health-care-related factors.

BACKGROUND: Self-injury, a manifestation of severe psychological distress, is increased in cancer-bereaved youths. Little is known about the potential influence on the risk for self-injury of factors that could be clinically relevant to and modifiable by the health-care professionals involved in the care of the dying parent. METHODS: In a nationwide population-based anonymous study, 622 (73.1%) youths (aged 18-26) who, 6 to 9 years earlier at ages 13 to 16, had lost a parent to cancer answered study-specific questions about self-injury and factors related to the family and parental health care. RESULTS: Univariable analyses showed that the risk for self-injury was increased among cancer-bereaved youths who reported poor family cohesion the years before (relative risk [RR], 3.4, 95% confidence interval [CI], 2.5-4.6) and after the loss (RR, 3.3, 95% CI, 2.4-4.4), distrust in the health care provided to the dying parent (RR, 1.7, 95% CI, 1.2-2.4), perceiving poor health-care efforts to cure the parent (RR 1.5, 95% CI, 1.1-2.1) and poor efforts to prevent suffering (RR, 1.6, 95% CI, 1.1-2.4), that at least one of their parents had been depressed or had troubles in life (RR, 1.5, CI, 1.1-2.1) and believing 3 days before the loss that the treatment would probably cure the parent (RR, 1.6, CI, 1.1-2.3). In the total multivariable models, only poor family cohesion before and after the loss remained statistically significantly associated with self-injury. CONCLUSION: Poor family cohesion before and after the loss of a parent to cancer is associated with an increased risk of self-injury in teenage children

Teenagers want to be told when a parent's death is near: A nationwide study of cancer-bereaved youths' opinions and experiences.

BACKGROUND: We aimed to investigate cancer-bereaved youths' opinions and experiences of being told about a parent's imminent death from cancer and of barriers to this communication. MATERIAL AND METHODS: This nationwide population-based survey included 622/851 (73%) youths (aged 18-26) who at age 13-16, 6-9 years earlier had lost a parent to cancer. RESULTS: In total 595 of 610 (98%) of the participants stated that teenage children should be informed when the parent's death was imminent (i.e. a matter of hours or days, not weeks). 59% stated that they themselves had been told this, 37% by the parents, 7% by parents and healthcare professionals together and 8% by professionals only. Frequent reasons for why the teenager and parents did not talk about imminent death before loss were that one (n=106) or both (n=25) of the parents together with the teenage child had pretended that the illness was not that serious, or that none of the parents had been aware that death was imminent (n=80). Up to a couple of hours before the loss, 43% of participants had not realized that death was imminent. CONCLUSION: In this population-based study virtually all youth who at ages 13-16 had lost a parent to cancer afterwards stated that teenagers should be told when loss is near, i.e. a matter of hours or days, not weeks. Many stated that they had not been given this information and few were informed by professionals, with implications for future improvements in end-of-life care of patients with teenage children

Bone defects following curettage do not necessarily need augmentation: A retrospective study of 146 patients

Background and purpose The natural pattern of bone healing in large bony defects following curettage alone as treatment of benign bone tumors around the knee is not well reported. We analyzed the outcome in 146 patients

Modified Ginstling–Brounshtein model for wet precipitation synthesis of hydroxyapatite: analytical and experimental study

Hydroxyapatite is the main mineral component in bones and teeth, thus being an important material in bone tissue engineering, e.g., for replacement and elimination of defects. Hydroxyapatite is widely used in real-life applications due to excellent biocompatibility and bioactivity. Wet precipitation synthesis of hydroxyapatite is limited by diffusivity. Hence, choice of a diffusion model becomes critical. The purpose of this work is three-fold. It experimentally validates the use of Ginstling–Brounshtein model for hydroxyapatite synthesis. It determines the effect of Ca(OH)2 concentration on the kinetics and reports a modified model to account for this phenomenon. It reports obtained kinetic constants that describe hydroxyapatite synthesis. Methods: Particle size was determined using scanning electron microscopy and digital microscopy. Conversion kinetics were monitored using powder X-ray diffraction. Results: Experimental validation was provided. Furthermore, the process was found dependent on the calcium hydroxide concentration and the model was modified to account for this phenomenon. Kinetic constants describing the synthesis of hydroxyapatite were obtained and reported. Conclusions: The model was well consistent with the experimental data and can be used for describing synthesis of hydroxyapatite for various suspension concentrations