Understanding the bias of mobile location data across spatial scales and over time: A comprehensive analysis of SafeGraph data in the United States.

Mobile location data has emerged as a valuable data source for studying human mobility patterns in various contexts, including virus spreading, urban planning, and hazard evacuation. However, these data are often anonymized overviews derived from a panel of traced mobile devices, and the representativeness of these panels is not well documented. Without a clear understanding of the data representativeness, the interpretations of research based on mobile location data may be questionable. This article presents a comprehensive examination of the potential biases associated with mobile location data using SafeGraph Patterns data in the United States as a case study. The research rigorously scrutinizes and documents the bias from multiple dimensions, including spatial, temporal, urbanization, demographic, and socioeconomic, over a five-year period from 2018 to 2022 across diverse geographic levels, including state, county, census tract, and census block group. Our analysis of the SafeGraph Patterns dataset revealed an average sampling rate of 7.5% with notable temporal dynamics, geographic disparities, and urban-rural differences. The number of sampled devices was strongly correlated with the census population at the county level over the five years for both urban (r > 0.97) and rural counties (r > 0.91), but less so at the census tract and block group levels. We observed minor sampling biases among groups such as gender, age, and moderate-income, with biases typically ranging from -0.05 to +0.05. However, minority groups such as Hispanic populations, low-income households, and individuals with low levels of education generally exhibited higher levels of underrepresentation bias that varied over space, time, urbanization, and across geographic levels. These findings provide important insights for future studies that utilize SafeGraph data or other mobile location datasets, highlighting the need to thoroughly evaluate the spatiotemporal dynamics of the bias across spatial scales when employing such data sources.

Influence of root canal fillings on longevity of direct and indirect restorations placed within the General Dental Services in England and Wales.

AIM: To consider the survival of restorations in root filled and non-root filled teeth. METHODS: A data set was established consisting of patients, 18 years or older. For each patient on the database with a tooth restored with a direct or indirect restoration with or without a root filling, the subsequent history of intervention on that tooth was consulted, and the next date of intervention, if any could be found in the data set, was obtained. Thus a data set was created of restored teeth and whether they have also received root fillings, with the dates of restoration and root filling placement and the dates, if any, of re-intervention. Modified Kaplan-Meier statistical analysis was used to quantify the distribution of time to intervention. RESULTS: Data for over 80,000 different adult patients were analysed, of whom 46% were male and 54% female. A total of 538,967 restoration placements were obtained from the data over a period of 11 years, of which 30,073 were root fillings. CONCLUSIONS: Examination of the survival of restorations in teeth with and without root canal fillings indicated that those with root canal fillings have shorter intervals before re-intervention than teeth without root fillings. Restorations on root canal treated anterior teeth with post and cores had the lowest survival time.

[Giant bronchogenic cyst in a newborn infant]. / Kyste bronchogénique géant du nouveau-né.

A 12 hour old newborn suffering from respiratory distress was found to have a well defined opaque mass in the right lung. The mass was well tolerated up the 33rd day of life when he developed acute respiratory distress, the upper respiratory tract being flooded with secretions. Chest X ray showed that the mass had disappeared and that there was a large cystic structure instead. A bronchogenic cyst was excised successfully from the right middle lobe. The early clinical manifestations of this bronchogenic cyst and the radiologic findings are discussed.

[Enteropathic acrodermatitis treated with zinc sulfate]. / Acrodermatitis enteropathica traitée par le sulfate de zinc.

A six month old baby with acrodermatitis enteropathica was treated successfully up to the age of 2 1/2 years with oral zinc sulphate, 100 mg daily. No complications were seen but there were two relapses. The first was at the age of 15 months when the dose of zinc sulphate was reduced to 50 mg daily and the second at 20 months when the zinc was stopped by mistake.

[Bone scan in the diagnosis of infectious osteoarthritis (author's transl)]. / Intérêt de la scintigraphie pour le diagnostic des infections ostéo-articulaires.

Bone scan with Technetium 99m is harmless method of evaluation of skeletal lesions. It is safe in pediatrics age group and it can be used in early diagnosis of infectious osteoarthritis. Bone scan differentiate osteomyelitis from cellulitis, and also it may help in diagnosis of subclinical involvement of rheumatoid arthritis, benign and malignant bone tumors, stress fractures and periositis. We report results of bone scan in 30 pediatric patients as follows: osteomyelitis 9 cases, cellulitis 4 cases, infectious arthritis 4 cases, tuberculous osteoarthritis 2 cases, rheumatoid arthritis 2 cases, and other different diseases 9 cases.

[Papillon-Lefèvre syndrome and recurrent infections]. / Syndrôme de Papillon-Lefèvre et infections récurrentes.

Seven cases of Papillon-Lefevre syndrome are described, 4 children and their mother with two other relatives on the mother's side. An immune defect was suspected because six of the seven had a history of severe pyogenic infections, but the results of the tests were not the same in the three individuals tested. In one patient no immune defect was detected but in the other two the response of lymphocytes to candida and to streptokinase and streptodornase was reduced.

[Diffuse cutaneous vasculitis disclosing acute lymphoblastic leukemia]. / Vascularite cutanée diffuse révélatrice d'une leucémie lymphoblastique aigüe.

Biopsy of skin for etiologic evaluation of generalized erythematous eruptions in a 4 1/2 years old child, starting four months ago, led to diagnosis of acute lymphoblastic leukemia. Leukocyte counts five and eight weeks and four months after appearance of eruptions were normal and no blasts were found. A leukocyte count performed simultaneously with biopsy of skin also showed few (less than 10%) blasts. Histologic examination of skin revealed two types of pathologic lesions: a perivascular cuffing of lymphoblasts and a leukocytoclastic type of small vessel vasculitis in other parts. This type of vasculitis which have been reported in association with chronic lymphocytic and hairy cell leukemias, is uncommon in acute lymphoblastic leukemia.

[Acute hemiplegia due to cerebral artery occlusion in children. Apropos of 9 cases]. / Hémiplégie aiguë par l'occlusion des artères cérébrales chez l'enfant. A propos de neuf observations.

The cerebral arterial occlusion was observed from nine patients aged from 2,5 to 12 years old, between 37 children with acute acquired hemiplegia. The thrombosis had an embolic origin in three cases of cardiopathy. Six patients had primary arterial occlusion, but all these patients were febrile and the onset of hemiplegia was accompanied by seizures in five cases. The site of arterial was demonstrated by the angiography in eight cases: cervical internal carotide in one case of cardiomyopathy, intracranial portion of the internal carotide in four cases, middle and anterior cerebral artery in three cases. The regression of hemiplegia was observed in all but one case of atrial myxoma. The autopsy of this patient revealed renal and hemispheric cerebral arterial thrombosis with myxoma embolus.

[Thromboangiitis obliterans and distal gangrene in a 5-year-old child]. / Thromboangéite oblitérante et gangrène distale chez un enfant de 5 ans.

Distal gangrene associated with arterial hypertension but without systemic manifestations or muco-cutaneous eruptions was noted in a 5 years old child. Gangrene first appeared in toes and then in fingers. Progression in a 7 months period led to bilateral midleg amputation and amputation of several fingers. Angiography revealed complete obliteration of popliteal and humeral arteries by thrombi and histologic examination of amputated material showed organized thrombi with phlebothrombosis and without vasculitis. Biopsies of liver, lung, kidneys and skin were unremarkable and immunofluorescence studies with various antisera were negative. Also no contributing factor or etiologic agents were found, similarities to adult type Buerger's disease are striking. Vasodilators were of no help and bilateral lumbar and cervical sympathectomy could only demarcate the already present gangrene.