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Social media use in the United States has been steadily increasing over the past decade as various social media platforms have become the primary channel of online engagement for the American internet user. Today, Americans use social media to communicate with friends, family, and peers, access entertainment and education, engage in various business and commercial activities, and influence the lifestyles of consumers. As the spectrum of purposeful use of social media diversifies, this paper examines geographic patterns of social media adoption, diffusion, and utilization in U.S. counties. Alongside, the paper also examines demographic and socioeconomic determinants of purposeful social media utilization. Overall, the study sheds light on an important aspect of the contemporary digital divide in the United States. To examine purposeful social network and media use, the paper focuses on penetration of popular social media/networking platforms such as Facebook, Twitter, LinkedIn, Instagram, and YouTube in U.S. counties. The purpose of use of such platforms – to engage in e-communication, e-commerce, e-entertainment, e-health, and e-education are also examined through the dual lenses of geographic and socioeconomic variations. By borrowing from Adoption-Diffusion Theory (ADT) and Spatially Aware Technology Utilization Model (SATUM), the paper’s conceptual framework posits associations of 18 independent variables with 17 indicators of social media penetration and purposeful usage. Spatial patterns and disparities of social media penetration and purposeful use are analyzed and provide important clues about the geography of the social media digital divide. For example, social media penetration and purposeful use in counties in the U.S. rural south are found to rival counties in the Rocky Mountain States and in some cases exceed counties in urban metropolitan areas in the West- and East Coasts. The presence of spatial bias in social media penetration and use is also diagnosed using spatial autocorrelation analysis. This in turn influences the Ordinary Least Squares (OLS) regression-based analysis of socioeconomic, infrastructural, and social capital underpinnings. For a sample of 3,076 counties in the lower 48 states, leading determinants of purposeful social media use are found to be age structure, urbanization, race/ethnicity and professional, scientific, technical services and overall service sector occupations are found to influence social network access and purposeful use. These findings have important policy implications to broaden the reach and impacts of social media in the U.S. Overall, as the digital divide literature expands its focus from access to information and communication technologies (ICTs) to their actual use and ultimate impact, this study is unique due to its focus on purposeful use of social media. Sourcing data from a variety of public- and private sources, the study focuses on social media usage as well as access and sheds light on county-level disparities and their socioeconomic underpinnings. As purposeful internet use continues to diversify, the findings of this study can inform social media adoption, diffusion, and use policies in light of the COVID-19 pandemic to ensure that all Americans can participate and engage in online activities and derive benefits in an equitable way.

As attention in digital divide research shifts from internet access to its use, and subsequently its impacts, this paper examines purposeful uses of the internet for the US states in 2017 using data from the Digital Nation Data Explorer of the National Telecommunications and Information Administration (NTIA). The conceptual model posits relationships of a group of demographic, societal, economic, and social capital variables to purposeful internet use (PIU) dependent variables that reference spatial clustering. The research questions are examine spatial patterns of PIU in US states and associations of demographic, socio-economic, affordability, innovation, social capital and societal openness factors with PIU dependent variables. Methods employed include k-means cluster analysis, mapping, and Ordinary Least Squares (OLS) regression analysis. Findings reveal unique cluster-based spatial patterns of high and low PIU in regions of the nation. The regression associations indicate that leading factors influencing PIU are professional, managerial, science and arts occupation, age (an inverse effect), social capital (positive effect), selected racial/ethnicity factors, and societal openness, with differences between PIU indicators for e-communication, e-entertainment, e-education, e-commerce, e-health, and purposeful internet use for internet-of-things and location-based services. Policy implications of the findings are discussed. The study is novel due to its emphasis on purposeful uses representing a second-level digital divide, the spatial insights, and new empirical findings.

This study analyzes factors associated with availability and utilization of information and communication technologies (ICTs) for U.S. states. We construct an exploratory conceptual model of technology utilization in which eight dependent ICT availability and utilization factors are posited to be associated with fourteen independent socio-economic, demographic, innovation, social capital, and societal openness factors. Technology utilization variables are spatially analyzed to determine extent of agglomeration, and regression residuals are examined to eliminate spatial bias. Findings indicate social capital, education, societal openness, urbanization, and ethnicities are significantly associated with ICT utilization. We suggest important implications for policymakers at state and federal levels.

The research purpose is to identify the correlates of technology utilization for the world and major world regions, while screening for spatial bias. Conceptual theory is induced which posits that levels of technological utilization are based on social, economic, government, and societal openness factors, while recognizing that geographic proximity can be influential for this utilization; the model's endogenous factors are posited to account for proximity. Regression findings worldwide for broadband internet subscribers indicate that the important correlates are tertiary education and innovation capacity. The disaggregated findings provide a more refined view. For Europe, significant determinants are judicial independence and innovation capacity, while for Asia they are tertiary education, foreign direct investment, and innovation capacity. For combined Africa–Latin America, higher education, press freedom, and foreign direct investment are most significant. The empirical findings lead to a more complex theoretical model that distinguishes determinants for developed and developing nations. The study suggests that a nation's governmental policies be tailored to the distinctive factors that apply for that nation's developed or developing region and/or its continental region. For planners and policy makers, the study suggests that use of spatial analysis can contribute to greater understanding and more accurate investigation of digital divides.

This study of the digital divide within Japan utilizes data from the country's 47 prefectures for multivariate and spatial analysis of distributions of information and communication technology (ICT) variables. The paper constructs an exploratory conceptual model of technology utilization and expenditures in Japan, induced from prior literature. Ten dependent ICT utilization and expenditure factors are posited to be related to 12 independent demographic, economic, infrastructure, education, innovation and openness factors. The relationship of the independent to dependent factors is moderated by analysis of spatial patterns of technology utilization to examine proximities and reduce spatial bias. Based on the model, a multivariate analysis identifies correlates of the nation's digital divide, including patents registered by Japanese citizens, newspaper circulation, students and pupils per capita, household expenditures on education, rural/urban status, and Japan's aged population structure which has wide generational gaps. Spatial clusters and outliers of ICTs in prefectures are analyzed, with attention to their policy impacts. Findings suggest modifications to the conceptual model. Implications of findings for the country's official national technology planning policies are considered and recommendations made to expand them. Conceptual model for ICT factors in Japan is induced from literature and tested.Japan's cluster regions for ICT factors are statistically identified and characterized.Regression analysis gives correlates for ICT factors in Japan's prefecturesRegional ICT policies are proposed to supplement Japan's official national policies.Geospatial methods control for spatial autocorrelation of regression error terms.

Discourse and interest in the digital divide research community is steadily shifting beyond access and adoption to utilization, impact, and outcomes of information and communications technologies (ICTs), particularly the internet. In the United States, studies and surveys conducted by the National Telecommunications and Information Administration (NTIA) indicate increase in internet use in every corner of the country over the last two decades. However, recent surveys on ICT use indicate significant disparities in dimensions of internet use. For example Americans’ use of the internet to pursue e-education, e-health, e-commerce, e-entertainment, and telecommuting has varied significantly – longitudinally as well as geographically. Additionally, internet use habits are rapidly expanding, providing new insights into the emerging internet of things, wearable technologies, and new forms of social media usage. As novel technologies and lifestyles emerge, analysis of new disparities and dimensions of the “usage digital divide” stemming from social, economic, societal, and environmental factors becomes important. This research examines spatial clusters, geographic disparities, and socio-economic dimensions of existing and emerging dimensions of internet use among the 50 U.S. states. We adapt the Spatially Aware Technology Utilization Model (SATUM) for internet use by positing associations of 20 independent demographic, economic, infrastructural, affordability, innovation, societal openness, and social capital variables with 17 indicators of internet use spanning e-education, e-commerce, e-health, e-education, telecommuting, and emerging forms of internet use. Data on the 17 indicators of internet use are sourced from the July 2015 CPS Supplement on internet use from the U.S. Census. Data on traditional independent correlates are sourced from the same Supplement, U.S. Census of Population, U.S. Economic Census, while data on societal openness, social capital, infrastructure correlates are collected from George Mason University’ Mercatus Center, FCC’s National Broadband Map initiative, and noted political scientist Robert Putnam’s publicly available data on civic engagement. First, descriptive mapping provides important visual cues about patterns of internet use in U.S. states. Subsequently, K-means cluster analysis of multiple internet use-related factors is conducted to determine agglomerations of states that are most similar in patterns of internet use and outcomes. Subsequently, statistically significant “hotspots” and “coldspots” of internet use and outcomes among U.S. states are identified, followed by spatial autocorrelation analysis of various dimensions of internet usage. A-priori diagnosis of spatial autocorrelation is critical to understand and possibly account for the presence of spatial bias while examining social, economic, societal, and environmental underpinnings of internet usage. Regression residuals are mapped and examined for spatial autocorrelation. Systematic examination of rapidly evolving dimensions of internet use among U.S. states distinguishes this work. Novelties include thorough analysis of disparities stemming from geography, results showing socio-economic, infrastructural, affordability, civic engagement, and societal openness determinants of the internet “usage digital divide,” and longitudinal analysis of change dimensions. A methodological novelty is diagnosis of spatial autocorrelation of internet use, largely ignored in digital divide literature. Left undiagnosed, this can potentially bias regression-based associations of independent variables associated with internet usage. Finally, the findings of this work have critical policy implications at a time when expanding and stimulating greater variety and intensity of internet use and impacts are well-recognized as aspirations of state and federal policies.

Prominent K K ¯ resonances observed in the in-flight annihilation of p ¯ p into K + K − π 0 include f 2 ( 1270 ) , f 0 ( 1500 ) , f 2 ′ ( 1525 ) , ϕ ( 1680 ) / ρ ( 1700 ) and a state at 1750 MeV / c 2 consistent with f 0 ( 1710 ) . The reaction cross sections σ ( p ¯ p → X ( K + K − ) π 0 ) are obtained by means of a partial wave analysis. When these are combined with known K K ¯ partial widths, the resulting production rates of presumably non- n n ¯ states, X = f 0 ( 1710 ) and f 2 ′ ( 1525 ) , are found to be suppressed by an order of magnitude compared to f 0 ( 1500 ) and f 2 ( 1270 ) , respectively.

A new application of spatial analysis is developed and applied to study the international twin metropolitan region of Tijuana, Mexico, and San Diego, California. Information on 16 variables from the US and Mexican censuses are merged in a common framework. A two-stage cluster analysis is applied to small area samples to determine metropolitan zones with common sets of characteristics. The results of the cluster analysis are spatially mapped and analyzed. This is done for all 16 variables, as well as for four variable groups that are determined through literature review and experience, and for an alternative set of variable groups derived from the data. The extent of commonality, defined as the similarity between socioeconomic and demographic profiles of the population in the San Diego–Tijuana region, is examined through the development of a commonality index that is determined by the extent of cluster overlap on both sides of the border. The findings are interpreted with respect to the research literature. The methods can be applied within academic research or in the planning of border cities having consistent data sets on both sides.

This paper analyzes socioeconomic influences on technological levels for 164 counties in the United States. The conceptual framework is that social and economic dimensions impact the sizes of technology sectors in counties, i.e. technology does not develop by itself but in concert with pre-disposing characteristics of the environment. Based on correlation and regression analyses, the findings reveal that nationally in the US, factors that are important correlates of technology sectors are professional/scientific/technical services workforce, other services workforce, household income, federal grant funds, college education, and ethnicity. The study reveals a large range in technology levels across the nation. There are distinctive influences for counties in ''sunbelt'' versus ''traditional'' subsamples, and in ''high-tech'' versus ''low-tech'' subsamples. The findings are discussed in terms of relevant academic and policy literature. The paper implies that certain ''indirect'' steps can be taken by national, state, and local governments to reduce the digital divide.

Data are presented on antiproton neutron annihilation at rest into ωπ − π 0 taken with the Crystal Barrel detector at LEAR (CERN) using a liquid deuterium target. The partial wave analysis shows evidence for at least two ωπ vector resonances above the ρ (770) ground-state. Possible evidence for a third ρ ′ state with a mass around 1180 MeV is discussed. The results are compared to model dependent predictions concerning the nature of the ρ ′ states.

Annihilation of antiprotons and protons at rest into neutral particles has been studied with the Crystal Barrel detector at LEAR. Annihilation frequencies are determined for final states containing π 0 , η , η ′ and ω mesons using a liquid and a room temperature, 12 bar, gaseous hydrogen target. Including annihilation frequencies for production of neutral kaons from other experiments, the identified reactions for annihilation in liquid hydrogen add up to a branching fraction of (3.56±0.28)% per annihilation compared to the frequency of (3.50±0.30)% with which we observe the all-neutral decay modes inclusively. Since the exclusive final states are normalized to the Crystal Barrel measurement of the π 0 π 0 branching ratio, the latter result is strongly supported by this present study.

Measurements of two-body branching ratios for p p annihilations at rest in liquid and gaseous (12 ρ STP ) hydrogen are reported. Channels studied are p p →π 0 π 0 ,π 0 η , K 0 S K 0 L , K + K − . The branching ratio for the π 0 π 0 channel in liquid H 2 is measured to be ( 6.14±0.40)×10 −4 . The results are compared with those from other experiments. The fraction of P-state annihilation for a range of target densities from 0.002 ρ STP to liquid H 2 is determined. Values obtained include 0.11±0.02 in liquid H 2 and 0.48±0.04 in 12 ρ STP H 2 gas.

ϱ′-states have been studied in several decay modes observed in data on pd annihilation at rest with the Crystal Barrel detector at LEAR. A comparison between the experimental results and theoretical calculations gives hints about the nature of the ϱ′ states.

The rho mass, width and line shape in p(over)-bar-p annihilation at rest into pi(+)pi(-)pi(0)

Data are presented on the reaction pbar-p -> omega-omega-pizero at rest from the Crystal Barrel detector. These data identify a strong signal due to f2(1565) -> omega-omega. The relative production from initial pbar-p states 3P2, 3P1 and 1S0 is well determined from omega-omega decay angular correlations; P-state annihilation dominates strongly. A combined fit is made with data on pbar-p -> 3pizero at rest, where f2(1565) -> pizero-pizero is observed.

A partial wave analysis is presented of two high-statistics data samples of protonium annihilation into π 0 π 0 η in liquid and 12 atm gaseous hydrogen. The contributions from the 1 S 0 , 3 P 1 and 3 P 2 initial atomic fine structure states to the two data sets are different. The change of their fractional contributions when going from liquid to gaseous H 2 as calculated in a cascade model is imposed in fitting the data. Thus the uncertainty in the fraction of S-state and P-state capture is minimized. Both data sets allow a description with a common set of resonances and resonance parameters. The inclusion of a π η P-wave in the fit gives supportive evidence for the ρ (1405) , with parameters compatible with previous findings.

With antiprotons stopped in liquid deuterium, the p n annihilation channel π−π0η was studied using a final sample of 52 576 events obtained for a spectator proton momentum q q quantum numbers IG=1−, JPC=1−+. The extracted Breit-Wigner resonance parameters are m=(1400±20±20) MeV/c2 and Γ=(310±50+50−30) MeV/c2.

Crystal Barrel data are presented on p−p → ηπ0π0π0 at rest in liquid hydrogen and also in gaseous hydrogen at 12 bar. Annihilation from the initial 3P0 state relative to 3P2 is stronger in liquid than in gas by a factor 2.46 ± 0.15, in fair agreement with a prediction by Batty. There is a definite peak due to η(1440). Liquid data determine its mass as M = 1413 MeV, Γ = 49 ± 8 MeV. The mass is, however, lower in gas than in liquid by 12 ± 3 MeV; we attribute this mass shift to interference with broad background amplitudes. The η (1440) decays dominantly to ησ: BR [a0(980)π,a0 → ηπ]/BR[ησ] = 0.4 ± 0.2. However, there is strong destructive interference between these two decay modes. There is also a strong, broad ηππ component with JPC = 0−+, consistent with an earlier analysis proposing a very wide η(1800) resonance; it contributes 31% of the ηπ0π0π0 branching ratio in liquid. At the highest ηππ masses, there are definite 2−+ and l++ signals, but we cannot establish precise resonance masses or widths. There is also evidence for the production of f2 (1565), decaying to a2 (1320)π.

The π 0 momentum dependence of the decay η → π + π − π 0 has been measured with the Crystal Barrel detector. The analysis is based on 3230 events. The results of this independent measurement are compared to new chiral perturbation theory calculations and previous measurements.

The decay p p ( at rest ) → K L o K ± π ∓ π o , studied on a sample of more than 14000 events, is found to proceed dominantly via two-body channels containing resonances with open strangeness. Contributions from K 1 (1270) K and K 1 (1400) K , branching into the successive K1-decay modes, and from K ∗ K ∗ , K ∗ ( K π) s and (Kπ) s ( K π) s are extracted by means of a partial-wave analysis which accounts well for the data and also allows a search for weak contributions from other (Kππ) and from ( K K π ) resonances. Striking asymmetries between the charged and the neutral kaonic resonances give evidence for interfering isospin 0 and 1 annihilation amplitudes.

The annihilation channel p p →K + K − π 0 in liquid hydrogen at rest has been studied with the Crystal Barrel detector at LEAR. The measured branching ratio is: BR ( p p → K + K − π 0 )=(2.37±0.15)×10 −3 . A partial wave analysis shows that this reaction is dominated by the π (K K ) S , K K ∗ (892) and π φ (1020) intermediate states. Weak signals are observed for π a 2 (1320), π f 2 (1270), π f 2 ′(1525) and K(Kπ) S . A satisfactory description of the Dalitz plot requires the introduction of π (K K ) P intermediate states with at least one pole.

We have measured the branching ratio for the radiative decay ω → ηγ with ω mesons produced in antiproton-proton annihilation at rest into π0ω and ηω. Taking into account ϱ - ω mixing we find a branching ratio B(ω → ηγ) = (6.6 ± 1.7) × 10−4, in accord with the constructive interference solution in other experiments. The upper-limit for the direct radiative decay ω → 3γ is 1.9 × 10−4 at 95% confidence level.

The π + π − invariant mass distribution produced in p p annihilation at rest and recoiling against η mesons exhibits large interference between the amplitudes for ϱη and ωη production. The interference can be quantitatively described within the framework of ϱ-ω interference. We find full coherence between the ϱω-ωη production amplitudes and a vanishing relative production phase. The implications of this result for p p annihilation dynamics are discussed.

Processes and measures of convergence for population matrices are considered based on additive norms other than the eigen-norm. Prior results on natural and spectral converges measures for population matrices [1] are shown to be partly valid for an arbitrarily weighted norm termed the W-norm. Special cases of imprimitive population matrices are analyzed for applicability of results on stability and convergence measures. These include the truncated case that includes post-fertile age groups and periodic cases, i.e., ones in which fertility occurs periodically across age groups.

A partial wave analysis of pp → π0π0η′ has been performed using the η′ → π0π0η and η′ → γγ decay modes. The data are dominated by an η′ recoiling against the (ππ) S-wave. In addition, α2 (1320) → η′π0 is needed. There is evidence for contributions from α0(1450) → η′π0. The branching ratio of α0(1450) → η′π0 with respect to ηπ0 is consistent with the prediction of SU(3).

Staffing, planning, and management control of information systems in the private not-for-profit (or nonprofit) sector are studied, based on a survey of symphony organizations in the United States and Canada. A conceptual model of information systems for charitable nonprofits is presented which emphasizes staffing, planning, and control. Empirical results for symphony orchestras reveal low IS funding, weaknesses in IS staffing, heavy dependence on outside expertise, low levels of IS training, inadequate IS planning and control, and moderate IS satisfaction. The model is tested empirically and found to be largely valid. A model modification is suggested in assessing the factor of IS satisfaction.

This paper examines tourism in Mexico. The research questions concern the long term role of the Mexican federal government in developing and stimulating tourism, the extent of tourism dependency of Mexico on the United States, and the extent of regional differences in tourism within Mexico. The method is simple economic trend analysis. The research results are illustrated by a case study of a leading Mexican hotel chain. Findings are interpreted in terms of world systems theory. The paper shows that Mexican tourism has a large variety of forms and is tied to processes of globalization.

Although the ketogenic diet has existed for over 75 years, the exact mechanism of action is still unknown. In 1921, R.M. Wilder, MD theorized that the ketosis and acidosis resulting from minimal caloric intake produced an anticonvulsant effect. Since then, other investigators have validated the efficacy of the ketogenic diet and it has become a more common therapy for children with intractable seizures. The classic ketogenic diet involves an initial period of starvation that is followed by a diet consisting of a 3:1 or 4:1 ratio of fat grams to grams of carbohydrate and protein. The purpose of the fasting phase is to stimulate ketogenisis and to initiate hunger which will encourage the child to consume the diet. Studies have shown that during the fasting period, children can become hypoglycemic and too ketotic. At least one death has been reported during the fasting period of the diet. Medication levels are often unstable during fasting which can cause nausea, vomiting and irritability. For these reasons the ketogenic diet is started at our facility without the traditional fasting phase. On the morning of admission to the hospital, the child is allowed to eat his/her usual breakfast at home (omitting concentrated sweets). Upon admission to the hospital the child is fed ketogenic meals totaling l/3 rd of his/her total daily caloric diet goal. On day 2 of admission the child is fed 2/3rds of his/her total daily caloric goal. Full calories are provided on day 3. The medical charts of eleven consecutive children were reviewed and the highest level of urine ketones registered for each of the three days was recorded. Ketone levels were measured with urinalysis reagent strips and indicated as negative/trace/small/moderate/large. By day 3 100% ( 11) of the children had registered large urine ketones on 2 or more readings. We feel our practice has allowed a smooth transition to the ketogenic diet while minimizing hypoglycemia, excessive ketosis, nausea, and inpatient hospital days.

It is estimated that thousands of megawatts of electricity could be generated from the geothermal fluids which underlie agricultural fields in Imperial County, California. Many potential environmental problems appear generally controllable. The possible inter-relationships between geothermal development and subsidence, seismicity, and water availability are, however, difficult to predict, and evaluation must await long-termed, commercial-sized operations. County population will interact with energy development through employment, geographical distribution, and interaction with the larger Mexican labor pool. Exportation of the bulk of the generated electricity, however, will limit the local socio-economic impact. County residents favor geothermal development at a ratio of almost 9:1. Thirteen policy recommendations applicable to other KGRA'S in the western U.S. include: the desirability of positive public opinion, the encouragement of on-line electrical power at an early stage in the development process, the importance of determining economic-technological exploitation feasibility, and the influences of local, state, and federal regulations.

A case history of a patient with metastatic renal cell carcinoma who had been asymptomatic is presented. The report emphasizes the need for consideration of any lesion in the maxillofacial region, as it may be the first definitive sign of a primary cancer.

This paper examines the sociodemographic factors affecting interregional migration to Baja California Norte between 1900 and 1980. Historical analyses reveal that migration patterns to Baja were influenced by: (1) political push and pull, i.e., the Bracero Program, (2) the proximity to the United States, and (3) demographic factors, e.g., distance among states and population size of state of origin. Our analysis suggests that the Bracero Program was the instigator of the larger flows of migration to Baja during its time. The program also caused some disruption of the usual distance regulator of Baja migration streams. The importance of the Bracero Program was further accentuated by the finding that flows to Baja subsequent to the program have returned to a distance-determined migration model.