scholarly journals Media Influences on Social Outcomes: The Impact of MTV’s 16 and Pregnant on Teen Childbearing

2015 ◽  
Vol 105 (12) ◽  
pp. 3597-3632 ◽  
Author(s):  
Melissa S. Kearney ◽  
Phillip B. Levine

This paper explores the impact of the introduction of the widely viewed MTV reality show 16 and Pregnant on teen childbearing. Our main analysis relates geographic variation in changes in teen childbearing rates to viewership of the show. We implement an instrumental variables (IV ) strategy using local area MTV ratings data from a pre-period to predict local area 16 and Pregnant ratings. The results imply that this show led to a 4.3 percent reduction in teen births. An examination of Google Trends and Twitter data suggest that the show led to increased interest in contraceptive use and abortion. (JEL D12, J13, J16, L82, Z13)

Author(s):  
Matthew E. Souther

Researchers disagree about the impact of board independence on firm value. The disagreement generally stems from the endogenous nature of board appointments. I add new evidence to this discussion by using a sample of closed-end funds to document the value-enhancing effects of independent boards. Using cross-sectional, difference-in-differences, and instrumental variables techniques, I address these endogeneity concerns and find consistent evidence that board independence is associated with higher firm value.


2017 ◽  
Vol 5 (4) ◽  
pp. 658-667 ◽  
Author(s):  
Ian Askew ◽  
Michelle Weinberger ◽  
Aisha Dasgupta ◽  
Jacqueline Darroch ◽  
Ellen Smith ◽  
...  

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 693
Author(s):  
Kvitoslava Obelovska ◽  
Olga Panova ◽  
Vincent Karovič

The performance of Wireless Local Area Network (WLAN) is highly dependent on the processes that are implemented in the Medium Access Control (MAC) sublayer regulated by the IEEE 802.11 standard. In turn, various parameters affect the performance of the MAC sublayer, the most important of which is the number of stations in the network and the offered load. With the massive growth of multimedia traffic, research of the network performance depending on traffic types is relevant. In this paper, we present the impact of a high-/low-priority traffic ratio on WLAN performance with different numbers of access categories. The simulation results show different impact of high-/low-priority traffic ratio on the performance of the MAC sublayer of wireless LANs depending on different network-sizes and on network conditions. Performance of the large network with two access categories and with the prevalent high-priority traffic is significantly higher than in the case of using four categories on the MAC sublayer. This allows us to conclude that the performance improvement of the large network with the prevalent high-priority traffic can be achieved by an adaptive adjustment of the access categories number on the MAC sublayer.


2021 ◽  
Author(s):  
Hamza Ben Hamadi ◽  
said ghnimi ◽  
Lassaad Latrach ◽  
Philippe Benech ◽  
Ali Gharsallah

Abstract This paper presents the design, simulation and fabrication of a miniaturized wearable dual-band antenna on a semi-flex substrate; she is operable at 2.45/5.8 GHz for wireless local area network applications. The electrical and radiation characteristics of this proposed antenna were obtained by means of a technical of insertion of a slot to tune the operating frequencies. To study the impact of the electromagnetic radiation of the structure of the human body, it is necessary to minimize the back radiation towards the user. Therefore, in this work, a multi-band artificial magnetic conductor (AMC) was placed directly above a dual-band planar inverted F antenna to achieve a miniaturization with excellent radiation performance. The simulation results were designed and simulated using Studio commercial software (CST). A good agreement was achieved between the results of simulation and the experimental. The Comparison of measurement results indicates that the gain improved from 1,84 dB to 3,8 dB, in the lower band, and from 2,4 dB to 4,1 in the upper band, when the antenna is backed by the AMC plane. The front-to-back ratio of the AMC backed PIFA antenna was also enhanced. Then, to ensure that the proposed AMC is harmless to the human body, this prototype was placed on three-layer human tissue cubic model. It was observed that the through inclusion of plane AMC, the peak specific absorption rate (SAR) decreased to 1,45 and 1,1 W/kg at 2,45 and 5.8 GHz, respectively (a reduction of around 3,7 W/kg, compared with an antenna without (AMC).


Author(s):  
Zhanibek Meiirkhanuly ◽  
Jacek A. Koziel ◽  
Baitong Chen ◽  
Andrzej Białowiec ◽  
Myeongseong Lee ◽  
...  

Environmental impact associated with odor and gaseous emissions from animal manure is one of the challenges for communities, farmers, and regulatory agencies. Microbe-based manure additives treatments are marketed and used by farmers for mitigation of emissions. However, their performance is difficult to assess objectively. Thus, comprehensive, practical, and low-cost treatments are still in demand. We have been advancing such treatments based on physicochemical principles. The objective of this research was to test the effect of the surficial application of a thin layer (¼"; 6.3 mm) of biochar on the mitigation of gaseous emissions (as the percent reduction, % R) from swine manure. Two types of biochar were tested: highly alkaline and porous (HAP) biochar made from corn stover and red oak (RO), both with different pH and morphology. Three 30-day trials were conducted with a layer of HAP and RO (2.0 & 1.65 kg∙m-2, respectively) applied on manure surface, and emissions of ammonia (NH3), hydrogen sulfide (H2S), greenhouse gases (GHG), and odorous volatile organic compounds (VOCs) were measured. The manure and biochar type and properties had an impact on the mitigation effect and its duration. RO significantly reduced NH3 (19-39%) and p-cresol (66-78%). H2S was mitigated (16~23%), but not significantly for all trials. Significant (66~78%) reductions for p-cresol were observed for all trials. The phenolic VOCs had relatively high % R in most trials but not significantly for all trials. HAP reduced NH3 (4~21%) and H2S (2~22%), but not significantly for all trials. Significant % R for p-cresol (91~97%) and skatole (74~95%) were observed for all trials. The % R for phenol and indole ranged from (60~99%) & (29~94%) but was not significant for all trials. The impact on GHGs, isobutyric acid, and the odor was mixed with some mitigation and generation effects. However, larger-scale experiments are needed to understand how biochar properties and the dose and frequency of application can be optimized to mitigate odor and gaseous emissions from swine manure. The lessons learned can also be applicable to surficial biochar treatment of gaseous emissions from other waste and area sources.


2020 ◽  
Vol 55 (1) ◽  
pp. 24-32
Author(s):  
Mária Demjanovičová

Local companies from different areas that are successful on social networks were chosen for the survey. The aim of the article is to identify the company's corporate values and their impact on the results of marketing communication as well as to find the attributes that are used in such successful companies and to make generalization of them. Several local companies do not invest a lot of money in marketing, but their results on social networks are comparable or even better than the ones of corporations managed by social networking agencies. What is the essence of their success and how it impacts the value of the company? The paper describes perceived value of entrepreneurs from small local companies through quality methods of research – personal interview and theoretical basis in this field. This data allowed to prepare a research, which shows four interest areas of the perceived value in small companies. The companies were selected from Slovakia, from among small and medium companies in local area in May 2019. In the research seventeen companies were involved and the main objective of the research was to gain as much information as possible about companies value and the value perceived by entrepreneurs. For this reason personal interview was used. The research result can bring parameters of perceived value in first step and later can provide a helpful model of managing value and the steps for understanding and creating the value of local company.


2018 ◽  
Vol 3 (2) ◽  
pp. 137-150
Author(s):  
Bijaya Mani Devkota

  Fertility has an important role for demographic transition and total fertility rate (TFR) which is one component measurements of fertility. Absences of complete and reliable data, a large number of indirect techniques have been developed to estimate demographic parameters. Some of these techniques are based on stable population theory and others are regression equations between the dependent variables, the TFR and the independent variables, the socio economic as well as demographic variables. The unwanted or unintended pregnancies can be avoided through the use of contraceptives; it becomes very important to estimate the births averted or pregnancies stopped by use of contraception. Though there is increase in the use of contraception, still many couples do not use contraception in spite of the fact that they require to use contraception. To satisfy this unmet need of contraception is one of the policy targets of national population policy for population stabilization. In this study, 12862 married females between 15-49 years of age, whose marital duration is more than 5 years, have been taken to study the distribution on different background characteristics and their behavior. Firstly, a regression study was done to know the impact on contraceptive use and further multivariate study has been carried out to know the effect of background characteristics and behavior on absence of birth five years jointly at different sub division. This method is based on the relationship between the Total fertility rate (TFR) and contraceptive prevalence rate (CPR).By using this modified estimate of TFR, birth averted for different area. The variables are CPR that about 71.4 percent variation in TFR can be explained by the first regression approach. The second is based on the relationship between total fertility rate (TFR) and Additive combination of CPR and proportion of currently married females having open birth interval (NPV) explained about 82percent of the variation in TFR. The findings revealed that the TFR calculated by the present method are quite close to the observed values of the TFR. Estimates of births averted and the percent change in births in the absence of contraception, based on the two methods are fairly consistent.


2014 ◽  
Vol 651-653 ◽  
pp. 2394-2397
Author(s):  
Ya Feng ◽  
Dong Liang Cui ◽  
Jun Mei Yang ◽  
Chao He

Extreme programming and the UNIVAC computer, while unproven in theory, have not until recently been considered private. In this position paper, we argue the study of superblocks, which embodies the essential principles of artificial intelligence. We describe an algorithm for virtual modalities, demonstrating that lambda calculus and local-area networks can interact to answer this challenge.


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