15 research outputs found

    Late vertebral side effects in long-term survivors of irradiated childhood brain tumor

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    Purpose: Long-term side effects of the treatments are common in survivors of irradiated pediatric brain tumors. Ionizing radiation in combination with surgery and chemotherapy during childhood may reduce vertebral height and bone mineral density (BMD), and cause growth failure. The aim of this study was to evaluate the late consequences of tumor treatments on vertebrae in survivors of childhood brain tumors.Methods: 72 adult survivors (mean age 27.8 years, standard deviation 6.7) of irradiated childhood brain tumor were studied by spinal magnetic resonance imaging (MRI) for vertebral abnormalities from the national cohort of Finland. Patients were treated in five university hospitals in Finland between the years 1970 and 2008. Subject height and weight were measured and body mass index (BMI) was calculated. The morphology and height/ depth ratio of the vertebrae in the middle of the kyphotic thoracic curvature (Th8) and lumbar lordosis (L3) were examined. Vertebrae were analyzed by Genant's semiquantative (SQ) method and spinal deformity index (SDI) was calculated. BMD was measured by using dual X-ray absorptiometry.Results: 4.2% (3/72) of the patients had undiagnosed asymptomatic vertebral fracture and 5.6% (4/72) of patients had radiation- induced decreased vertebral body height. Male patients had flatter vertebrae compared with females. Patient age at the time of irradiation, BMI and irradiation area correlated to vertebral morphology differentially in males and females. BMD had no association with the vertebral shape. Patients who had received craniospinal irradiation were shorter than the general population.Conclusion: Childhood brain tumor survivors had a high number of vertebral abnormalities in young adulthood. Irradiation was associated with abnormal vertebral morphology and compromised final height. Male gender may predispose vertebrae to the side effects of irradiation.</div

    Coordinated Spectrum Allocation and Coexistence Management in CBRS-SAS Wireless Networks

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    Since the introduction of the idea of cognitive radio, various approaches towards spectrum sharing have been considered, for example, the Licensed Shared Access (LSA), which is considered in Europe, or Citizens Broadband Radio Service (CBRS) with Spectrum Access System (SAS) regulated by the US. This paper deals with the problem of coordinated resource allocation among a set of available base stations. A detailed defnition of the problem is provided, followed by a discussion on a set of heuristics proposed for solving the problem. Four solutions are presented that are based on existing standards as well as on the approaches described in the literature. Next, new multi-selection (multi-choice) algorithm is proposed and discussed in detail. The main problem is divided in two subproblems, which are solved by using graph theorem and analytical description. The performance of the proposed solutions is analyzed in various scenarios. Finally, a trade-off between power allocation and frequency use is provided. All challenges identifed during the investigation of the problem are presented

    Trial of Spectrum Sharing in 2.3GHz Band for Two Types of PMSE Equipment and Mobile Network

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    This paper presents a trial on sharing spectrum between different actors in a flexible manner in 2.3 GHz band. Trial demonstrates a flexible use of shared spectrum providing means for the broadcasters and other Programme Making and Special Events (PMSE) stakeholders to gradually upgrade their equipment towards LTE/5G radio based equipment

    Body mass index trajectories from birth to midlife and vertebral dimensions in midlife:the Northern Finland Birth Cohort 1966 study

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    Abstract Vertebral fracture risk is higher among individuals with small vertebral dimensions. Obesity is a global health problem and may also contribute to bone size and fracture risk. In this work we report the association between life course body mass index (BMI) and vertebral cross‐sectional area (CSA) in midlife. The Northern Finland Birth Cohort 1966 study with its 46‐year follow‐up provided the material for this study. A subsample of 780 individuals had attended lumbar magnetic resonance imaging (MRI) at the age of 46 years, and had records of objectively measured BMI from the ages of 0, 7, 15, 31, and 46 years. Of these, MRI‐derived data on vertebral size was available for 682 individuals. We identified latent lifelong BMI trajectories by performing latent class growth modeling (LCGM) on the BMI data, and then used sex‐stratified linear regression models to compare the identified trajectory groups in terms of midlife vertebral CSA. Gestational age, education years, adult height, lifelong physical activity, lifelong smoking history, and adulthood diet were assessed as potential confounders. Three distinct trajectory groups (“stable slim,” “stable average,” and “early onset overweight”) were identified among both sexes. Comparisons to the stable slim trajectory revealed that vertebral CSA was significantly (p &lt; 0.001) larger among the stable average and early onset overweight trajectories (69.8 and 118.6 mm² larger among men, 57.7 and 106.1 mm² larger among women, respectively). We conclude that lifelong BMI has a positive association with midlife vertebral size among both sexes. Future studies should characterize the mediating factors of this association

    Effect of early life physical growth on midlife vertebral dimensions:the Northern Finland Birth Cohort 1966 study

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    Abstract Small vertebral size is an independent risk factor for osteoporotic vertebral fractures. Physical growth in early life is related to bone health in later life, but the relationship of early growth versus vertebral size has been inconclusively studied. Utilizing the Northern Finland Birth Cohort 1966 with a 47-year follow-up, we investigated how physical growth in early life is associated with midlife vertebral dimensions. We obtained several physical growth parameters of 1) birth (gestational age, length, weight, BMI), 2) infancy and childhood (peak height velocity (PHV), peak weight velocity (PWV), adiposity peak (AP), adiposity rebound (AR)), and 3) puberty (BMI at growth spurt take-off (TO), PHV, height change). We also studied 4) the ages at which AP, AR, pubertal TO and pubertal PHV occurred. The outcome variable, vertebral cross-sectional area (CSA), was obtained from magnetic resonance imaging scans at the mean age of 46.7 years (n = 517). Sex-stratified linear regression analyses were used with adjustments for gestational age, smoking, and education. Birth length/weight/BMI, and adult height/weight/BMI were also used as covariates, depending on the model. According to our results, birth weight (p ≤ 0.006) and infant PWV (p ≤ 0.001) were positively associated with midlife vertebral CSA among both sexes. Length/height variables were associated with vertebral size only before including adult height in the models, and became non-significant thereafter. Among women, BMIs at birth, AP, AR, and pubertal TO were positively associated with midlife vertebral CSA (p &lt; 0.05), whereas among men, only high BMI at AR was associated with large vertebral size (p = 0.028). Gestational age and timing of growth were not associated with future vertebral CSA. We conclude that early life weight gain is positively associated with midlife vertebral CSA, and suggest that adult height may mediate the effect of height gain on vertebral size

    Licensed shared access field trial and a testbed for satellite-terrestrial communication including research directions for 5G and beyond

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    SummaryThis paper describes a licensed shared access (LSA) testbed and field trials using a live network. The testbed includes real 4G base stations and up to 1000 virtual base stations, in the spectrum sharing scenario between satellite and cellular systems. The trials focus on 5G pioneer bands 3.4–3.8 GHz and 24.25–27.5 GHz where a satellite system is operating in the downlink direction and a cellular system is accessing the same band. The designed testbed supports both frequency bands. The performance evaluation concerns evacuation and frequency change times using different types of base stations in 3.6 GHz, that is, how fast the system relinquishes the shared band to the primary user and continues transmission using another band. We show that our LSA system is scalable and able to support large number of base stations. In addition, we investigate how satellite systems could reuse International Mobile Telecommunication (IMT) bands to offer enhanced satellite communication services for land, maritime, and aeronautical applications. Preliminary simulations and analysis confirm the possibility to reuse IMT spectrum for satellite systems without causing harmful interference to the terrestrial system

    Late vertebral side effects in long-term survivors of irradiated childhood brain tumor

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    Purpose Long-term side effects of the treatments are common in survivors of irradiated pediatric brain tumors. Ionizing radiation in combination with surgery and chemotherapy during childhood may reduce vertebral height and bone mineral density (BMD), and cause growth failure. The aim of this study was to evaluate the late consequences of tumor treatments on vertebrae in survivors of childhood brain tumors. Methods 72 adult survivors (mean age 27.8 years, standard deviation 6.7) of irradiated childhood brain tumor were studied by spinal magnetic resonance imaging (MRI) for vertebral abnormalities from the national cohort of Finland. Patients were treated in five university hospitals in Finland between the years 1970 and 2008. Subject height and weight were measured and body mass index (BMI) was calculated. The morphology and height/ depth ratio of the vertebrae in the middle of the kyphotic thoracic curvature (Th8) and lumbar lordosis (L3) were examined. Vertebrae were analyzed by Genant's semiquantative (SQ) method and spinal deformity index (SDI) was calculated. BMD was measured by using dual X-ray absorptiometry. Results 4.2% (3/72) of the patients had undiagnosed asymptomatic vertebral fracture and 5.6% (4/72) of patients had radiation- induced decreased vertebral body height. Male patients had flatter vertebrae compared with females. Patient age at the time of irradiation, BMI and irradiation area correlated to vertebral morphology differentially in males and females. BMD had no association with the vertebral shape. Patients who had received craniospinal irradiation were shorter than the general population. Conclusion Childhood brain tumor survivors had a high number of vertebral abnormalities in young adulthood. Irradiation was associated with abnormal vertebral morphology and compromised final height. Male gender may predispose vertebrae to the side effects of irradiation.Peer reviewe
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