A Survey of Satellite Communications System Vulnerabilities

The U.S. military’s increasing reliance on commercial and military communications satellites to enable widely-dispersed, mobile forces to communicate makes these space assets increasingly vulnerable to attack by adversaries. Attacks on these satellites could cause military communications to become unavailable at critical moments during a conflict. This research dissected a typical satellite communications system in order to provide an understanding of the possible attacker entry points into the system, to determine the vulnerabilities associated with each of these access points, and to analyze the possible impacts of these vulnerabilities to U.S. military operations. By understanding these vulnerabilities of U.S. communications satellite systems, methods can be developed to mitigate these threats and protect future systems. This research concluded that the satellite antenna is the most vulnerable component of the satellite communications system’s space segment. The antenna makes the satellite vulnerable to intentional attacks such as: RF jamming, spoofing, meaconing, and deliberate physical attack. The most vulnerable Earth segment component was found to be the Earth station network, which incorporates both Earth station and NOC vulnerabilities. Earth segment vulnerabilities include RF jamming, deliberate physical attack, and Internet connection vulnerabilities. The most vulnerable user segment components were found to be the SSPs and PoPs. SSPs are subject to the vulnerabilities of the services offered, the vulnerabilities of Internet connectivity, and the vulnerabilities associated with operating the VSAT central hub. PoPs are susceptible to the vulnerabilities of the PoP routers, the vulnerabilities of Internet and Intranet connectivity, and the vulnerabilities associated with cellular network access

Utility of Different Blood Pressure Measurement Components in Childhood to Predict Adult Carotid Intima-Media Thickness : The i3C Consortium Study

Childhood blood pressure (BP) levels predict adult subclinical atherosclerosis. However, the best childhood BP component for prediction has not been determined. This study comprised 5925 participants aged 3 to 18 years from 6 cohorts who were followed into adulthood (mean follow-up 25.8 +/- 6.2 years). Childhood BP was measured by using a standard mercury sphygmomanometer in all cohorts. Study-specific carotid intima-media thickness 90th percentile was used to define subclinical atherosclerosis. Per SD change in the predictor, childhood systolic BP (SBP; age- and sex-adjusted odds ratio [95% CI], 1.24 [1.13-1.37]), mean arterial pressure (1.10 [1.07-1.13]), and pulse pressure (1.15 [1.05-1.27]) were associated with increased adulthood intima-media thickness. In age- and sex-adjusted analyses, area under the receiver operating characteristic curves for SBP (C value [95% CI], 0.677 [0.657-0.704]) showed significantly improved prediction compared with diastolic BP (0.669 [0.646-0.693], P=0.006) or mean arterial pressure (0.674 [0.653-0.699], P=0.01). Pulse pressure provided a C value that was not different from SBP (0.676 [0.653-0.699], P=0.16). Combining different BP components did not improve prediction over SBP measurement alone. Based on the associations with adult carotid intima-media thickness, cut points for elevated SBP were 105 mmHg for 3- to 6-year-old boys, 108 mmHg for 3- to 6-year-old girls, 108 mmHg for 7- to 12-year-old boys, 106 mmHg for 7- to 12-year-old girls, 123 mmHg for 13- to 18-year-old boys, and 115 mmHg for 13- to 18-year-old girls. Our analyses suggest that several childhood BP measurement components are related to adulthood carotid intima-media thickness. Of these, SBP provided the best predictive ability.Peer reviewe

Cardiovascular risk factors before and during pregnancy: Does pregnancy unmask or initiate risk?

Objectives: To understand if pregnancy unmasks previously silent cardiovascular (CV) adverse factors, or initiates lasting injury.Methods: Pre-pregnancy and during pregnancy CV risk factors (blood pressure, fasting lipids, and glucose) from 296 women belonging to studies in the International Childhood Cardiovascular Cohort (i3C) Consortium, a group of studies assessing the relationship between child and adolescent CV risk factors and adult outcomes, were used. Correlation coefficients between the pre- and during pregnancy measures were calculated, and the mean difference between the measures was modeled with adjustment for age, body mass index, race, smoking, and study.Results: Measures were strongly correlated at pre- and during-pregnancy visits (p Conclusions: Pre- and during-pregnancy CV risk factors are moderately well correlated. This may indicate that susceptible women enter pregnancy with higher risk rather than pregnancy inducing new vascular or metabolic effects.</p

Childhood BMI and Fasting Glucose and Insulin Predict Adult Type 2 Diabetes: The International Childhood Cardiovascular Cohort (i3C) Consortium

OBJECTIVE To examine childhood BMI, fasting glucose, and insulin in relation to incident adult type 2 diabetes mellitus (T2DM). RESEARCH DESIGN AND METHODS We used data from the International Childhood Cardiovascular Cohort (i3C) Consortium. Data included childhood (age 3-19 years) measurements obtained during the 1970s-1990s; a health questionnaire, including self-report of adult T2DM (occurrence age, medication use) obtained at mean age 40 years; and a medical diagnosis registry (Finland). RESULTS The sample included 6,738 participants. Of these, 436 (6.5%) reported onset of T2DM between ages 20 and 59 (mean 40.8) years, and 86% of them reported use of a confirmed antidiabetic medication. BMI and glucose (age and sex standardized) were associated with incident T2DM after adjustment for cohort, country, sex, race, age, and calendar year of measurement. Increasing levels of childhood BMI and glucose were related to an incrementally increased risk of T2DM beginning at age 30 years, beginning at cut points CONCLUSIONS Childhood BMI and glucose are predictors of adult T2DM at levels previously considered to be within the normal range. These easy-to-apply measurements are appealing from a clinical perspective. Fasting insulin has the potential to be an additional predictor.</div

Childhood age and associations between childhood metabolic syndrome and adult risk for metabolic syndrome, type 2 diabetes mellitus and carotid intima media thickness: The international childhood cardiovascular cohort consortium

Background There is paucity of knowledge concerning the specific age in youth when the associations of metabolic syndrome (MetS) begin to be operative. Thus, we investigated the relation of age to the associations of childhood MetS with adult MetS, type 2 diabetes mellitus and high carotid intima‐media thickness.Methods and Results Five thousand eight‐hundred three participants were analyzed in 4 cohort studies (Cardiovascular Risk in Young Finns, Bogalusa Heart Study, Princeton Lipid Research Study, Insulin Study). International cutoffs and previously used 75th percentile cutoffs were used for children to define MetS and its components. Mean follow‐up period was 22.3 years. Logistic regression was used to calculate risk ratios and 95% confidence intervals. Childhood MetS and overweight were associated with over 2.4‐fold risk for adult MetS from the age of 5 years onward. Risk for type 2 diabetes mellitus was increased from the age of 8 (risk ratio, 2.6–4.1; 95% confidence interval, 1.35–6.76 and 1.12–7.24, respectively) onward for the 2 childhood MetS criteria based on international cut‐off values and for childhood overweight. Risk for high carotid intima‐media thickness was significant at ages 11 to 18 years in relation to childhood MetS or overweight (risk ratio, 2.44–4.22; 95% confidence interval, 1.55–3.55 and 2.55–5.66, respectively). Continuous childhood MetS score was associated with adult MetS from the age of 5, with type 2 diabetes mellitus from the age of 14 and with high carotid intima‐media thickness from the age of 11 years onward.Conclusions Adult MetS was predicted by MetS in childhood beginning at age 5. However, adult type 2 diabetes mellitus and subclinical atherosclerosis were not predicted by childhood data until after age 8. Body mass index measurement alone at the same age points provided similar findings.</p

Childhood/Adolescent Smoking and Adult Smoking and Cessation: The International Childhood Cardiovascular Cohort (i3C) Consortium

BACKGROUND: Despite declining US adolescent smoking prevalence from 40% among 12th graders in 1995 to around 10% in 2018, adolescent smoking is still a significant problem. Using the International Childhood Cardiovascular Cohort (i3C) Consortium, which includes 7 international cohorts recruited in childhood and followed into adulthood, the present study was designed to confirm the important relation between adolescent smoking and daily adult smoking and present new data on adult smoking into the forties and comparison of smoking in the United States, Finland, and Australia. METHODS AND RESULTS: Childhood smoking experience during ages 6 to 19 in the 1970s and 1980s was classifiable in 6687 i3C participants who also provided smoking status in their twenties and forties through 2011-2018. Prevalence of daily smoking in their twenties was directly related to degree of smoking during adolescence and inversely related to the age at which that smoking experience occurred (P trend, < 0.001). Similar patterns were observed for prediction of smoking during age forties. Among the 2465 smokers in their twenties, cessation by their forties was generally inverse to degree of smoking in ages 6 to 19 (P trend, <0.001). Prevalence of smoking during adolescence and adulthood was similar among US, Finnish, and Australian participants. CONCLUSIONS: These long--term follow--up data show that smoking intensity increased throughout adolescence. Prevalence of adult smoking and cessation by the forties were both correlated with levels of childhood smoking intensity. These data lend support to preventive strategies designed to reduce, delay, or eliminate any youth access to cigarettes

Obesity during childhood is associated with higher cancer mortality rate during adulthood: the i3C Consortium

Background: In high-income countries, cancer is the leading cause of death among middle-aged adults. Prospective data on the effects of childhood risk exposures on subsequent cancer mortality are scarce. Methods: We examined whether childhood body mass index (BMI), blood pressure, glucose and lipid levels were associated with adult cancer mortality, using data from 21,012 children enrolled aged 3-19 years in seven prospective cohort studies from the U.S., Australia, and Finland that have followed participants from childhood into adulthood. Cancer mortality (cancer as a primary or secondary cause of death) was captured using registries. Results: 354 cancer deaths occurred over the follow-up. In age-, sex, and cohort-adjusted analyses, childhood BMI (Hazard ratio [HR], 1.13; 95% confidence interval [CI] 1.03-1.24 per 1-SD increase) and childhood glucose (HR 1.22; 95%CI 1.01-1.47 per 1-SD increase), were associated with subsequent cancer mortality. In a multivariable analysis adjusted for age, sex, cohort, and childhood measures of fasting glucose, total cholesterol, triglycerides, and systolic blood pressure, childhood BMI remained as an independent predictor of subsequent cancer mortality (HR, 1.24; 95%CI, 1.03-1.49). The association of childhood BMI and subsequent cancer mortality persisted after adjustment for adulthood BMI (HR for childhood BMI, 1.35; 95%CI 1.12-1.63). Conclusions: Higher childhood BMI was independently associated with increased overall cancer mortality.</p

Non-HDL Cholesterol Levels in Childhood and Carotid Intima-Media Thickness in Adulthood

BACKGROUND: Elevated non–high-density lipoprotein cholesterol (HDL-C) levels are used to identify children at increased cardiovascular risk, but the use of non–HDL-C in childhood to predict atherosclerosis is unclear. We examined whether the National Heart, Lung, and Blood Institute classification of youth non–HDL-C status predicts high common carotid artery intima-media thickness in adulthood.METHODS: We analyzed data from 4 prospective cohorts among 4582 children aged 3 to 19 years who were remeasured as adults (mean follow-up of 26 years). Non–HDL-C status in youth and adulthood was classified according to cut points of the National Heart, Lung, and Blood Institute and the National Cholesterol Education Program Adult Treatment Panel III. High carotid intima-media thickness (cIMT) in adulthood was defined as at or above the study visit-, age-, sex-, race-, and cohort-specific 90th percentile of intima-media thickness.RESULTS: In a log-binomial regression analysis adjusted with age at baseline, sex, cohort, length of follow-up, baseline BMI, and systolic blood pressure, children with dyslipidemic non–HDL-C were at increased risk of high cIMT in adulthood (relative risk [RR], 1.29; 95% confidence interval [CI], 1.07–1.55). Compared with the persistent normal group, the persistent dyslipidemia group (RR, 1.80; 95% CI, 1.37–2.37) and incident dyslipidemia (normal to dyslipidemia) groups (RR, 1.45; 95% CI, 1.07–1.96) had increased risk of high cIMT in adulthood, but the risk was attenuated for the resolution (dyslipidemia to normal) group (RR, 1.17; 95% CI, 0.97–1.41).CONCLUSIONS: Dyslipidemic non–HDL-C levels predict youth at risk for developing high cIMT in adulthood. Those who resolve their non–HDL-C dyslipidemia by adulthood have normalized risk of developing high cIMT in adulthood.</div

Utility of Different Blood Pressure Measurement Components in Childhood to Predict Adult Carotid Intima-Media Thickness

Childhood blood pressure (BP) levels predict adult subclinical atherosclerosis. However, the best childhood BP component for prediction has not been determined. This study comprised 5925 participants aged 3 to 18 years from 6 cohorts who were followed into adulthood (mean follow-up 25.8±6.2 years). Childhood BP was measured by using a standard mercury sphygmomanometer in all cohorts. Study-specific carotid intima-media thickness ≥90th percentile was used to define subclinical atherosclerosis. Per SD change in the predictor, childhood systolic BP (SBP; age- and sex-adjusted odds ratio [95% CI], 1.24 [1.13–1.37]), mean arterial pressure (1.10 [1.07–1.13]), and pulse pressure (1.15 [1.05–1.27]) were associated with increased adulthood intima-media thickness. In age- and sex-adjusted analyses, area under the receiver operating characteristic curves for SBP (C value [95% CI], 0.677 [0.657–0.704]) showed significantly improved prediction compared with diastolic BP (0.669 [0.646–0.693], P=0.006) or mean arterial pressure (0.674 [0.653–0.699], P=0.01). Pulse pressure provided a C value that was not different from SBP (0.676 [0.653–0.699], P=0.16). Combining different BP components did not improve prediction over SBP measurement alone. Based on the associations with adult carotid intima-media thickness, cut points for elevated SBP were 105 mm Hg for 3- to 6-year-old boys, 108 mm Hg for 3- to 6-year-old girls, 108 mm Hg for 7- to 12-year-old boys, 106 mm Hg for 7- to 12-year-old girls, 123 mm Hg for 13- to 18-year-old boys, and 115 mm Hg for 13- to 18-year-old girls. Our analyses suggest that several childhood BP measurement components are related to adulthood carotid intima-media thickness. Of these, SBP provided the best predictive ability.</p

Childhood Cardiovascular Risk Factors and Adult Cardiovascular Events

BACKGROUND Childhood cardiovascular risk factors predict subclinical adult cardiovascular disease, but links to clinical events are unclear. METHODS In a prospective cohort study involving participants in the International Childhood Cardiovascular Cohort (i3C) Consortium, we evaluated whether childhood risk factors (at the ages of 3 to 19 years) were associated with cardiovascular events in adulthood after a mean follow-up of 35 years. Body-mass index, systolic blood pressure, total cholesterol level, triglyceride level, and youth smoking were analyzed with the use of i3C-derived age- and sex-specific z scores and with a combined-risk z score that was calculated as the unweighted mean of the five risk z scores. An algebraically comparable adult combined-risk z score (before any cardiovascular event) was analyzed jointly with the childhood risk factors. Study outcomes were fatal cardiovascular events and fatal or nonfatal cardiovascular events, and analyses were performed after multiple imputation with the use of proportional-hazards regression. RESULTS In the analysis of 319 fatal cardiovascular events that occurred among 38,589 participants (49.7% male and 15.0% Black; mean [±SD] age at childhood visits, 11.8±3.1 years), the hazard ratios for a fatal cardiovascular event in adulthood ranged from 1.30 (95% confidence interval [CI], 1.14 to 1.47) per unit increase in the z score for total cholesterol level to 1.61 (95% CI, 1.21 to 2.13) for youth smoking (yes vs. no). The hazard ratio for a fatal cardiovascular event with respect to the combined-risk z score was 2.71 (95% CI, 2.23 to 3.29) per unit increase. The hazard ratios and their 95% confidence intervals in the analyses of fatal cardiovascular events were similar to those in the analyses of 779 fatal or nonfatal cardiovascular events that occurred among 20,656 participants who could be evaluated for this outcome. In the analysis of 115 fatal cardiovascular events that occurred in a subgroup of 13,401 participants (31.0±5.6 years of age at the adult measurement) who had data on adult risk factors, the adjusted hazard ratio with respect to the childhood combined-risk z score was 3.54 (95% CI, 2.57 to 4.87) per unit increase, and the mutually adjusted hazard ratio with respect to the change in the combined-risk z score from childhood to adulthood was 2.88 (95% CI, 2.06 to 4.05) per unit increase. The results were similar in the analysis of 524 fatal or nonfatal cardiovascular events. CONCLUSIONS In this prospective cohort study, childhood risk factors and the change in the combined-risk z score between childhood and adulthood were associated with cardiovascular events in midlife.publishedVersionPeer reviewe