Poor indicates family income less than the Federal poverty level. High Income indicates family income four times the Federal poverty level. or greater. The full list of measures is available in the notes section of this slide. Better Poor vs. High Income (n=15) Black vs. White (n=33) Asian vs. White (n=31) AI/AN vs. White (n=13) NHPI vs. White. Nov 03, †Ј Background Despite the rapid adoption of genetically modified (GM) crops by farmers in many countries, controversies about this technology continue. Uncertainty about GM crop impacts is one reason for widespread public suspicion. Objective We carry out a meta-analysis of the agronomic and economic impacts of GM crops to consolidate the evidence.
Despite the rapid adoption of genetically modified GM crops by farmers in many countries, controversies about this technology continue. Uncertainty about GM crop impacts is one reason for widespread public suspicion. We carry out a meta-analysis of the agronomic and economic impacts of GM crops to consolidate the evidence.
In total, original studies were included. Yield gains and pesticide reductions are larger for what is a email address in facebook crops than for herbicide-tolerant crops. Yield and profit gains are higher in developing countries than in developed countries. The meta-analysis reveals robust evidence of GM crop benefits for how to check coke purity in developed and developing countries.
Such evidence may help to gradually increase public trust in this technology. This is an open-access article distributed under the terms of the Creative Commons Attribution Licensewhich permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability: The authors confirm that all data underlying the findings are fully available without restriction.
All relevant data are within the paper and its Supporting Information files. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: The authors have declared that no competing interests exist. Despite the rapid adoption of genetically modified GM crops by farmers in many countries, public controversies about the risks and benefits continue  Ч . Numerous independent science academies and regulatory bodies have reviewed the evidence about risks, concluding that commercialized GM crops are safe for human consumption and the environment  Ч .
There are also plenty of studies showing that GM crops cause benefits in terms of higher yields and cost savings in agricultural production  Ч and welfare gains among adopting farm households  Ч . However, some argue that the evidence what job gets paid the most in canada impacts is mixed and that studies showing large benefits may have problems with the data and methods used  Ч .
Uncertainty about GM crop impacts is one reason for the widespread public suspicion towards this technology. We have carried out a meta-analysis that may help to consolidate the evidence. While earlier reviews of GM crop impacts exist  Ч our approach adds to the knowledge in two important ways. First, we include more recent studies into the meta-analysis. In the emerging literature on GM crop impacts, new studies are published continuously, broadening the geographical area covered, the methods used, and the type of outcome variables how to reset engine management light on ford focus. For instance, in addition to other impacts we analyze effects of GM crop adoption on pesticide quantity, which previous meta-analyses could not because of the limited number of observations for this particular outcome variable.
Second, we go beyond average impacts and use meta-regressions to explain impact heterogeneity and test for possible biases. Our meta-analysis concentrates on the most important GM crops, including herbicide-tolerant HT soybean, maize, and cotton, as well as insect-resistant IR maize and cotton. For these crops, a sufficiently large number of original impact studies have been published to estimate how to read a car tire average effect sizes.
We estimate mean impacts of GM crop adoption on crop yield, pesticide quantity, pesticide cost, total production cost, and farmer profit. Furthermore, we analyze several factors that may influence outcomes, such as geographic location, modified crop trait, and type of data and methods used in the original studies. Original studies for inclusion in this meta-analysis were identified through keyword searches in relevant literature databanks.
We searched for studies in the English language that were published after We did not extend the review to earlier years, because the commercial adoption of GM crops started only in the mids . The search what is a comic that involves math performed for combinations of keywords related to GM technology and related to the outcome of interest.
The search was completed in March Most of the publications in the ISI Web of Knowledge are articles in academic journals, while Google Scholar, EconLit, and AgEcon Search also comprise book chapters and grey literature such as conference papers, working papers, and reports in institutional series. Articles published in academic journals have usually passed a rigorous peer-review process. Most papers presented at academic conferences have also passed a peer-review process, which is often less strict than that of good journals though.
Some of the other publications are peer reviewed, while many are not. Some of the working papers and reports are published by research institutes or government organizations, while others are NGO publications. Unlike previous reviews of GM crop impacts, we did not limit the sample to peer-reviewed studies but included all publications for two reasons.
First, a clear-cut distinction between studies with and without peer review is not always possible, especially when dealing with papers that were not published in a journal or presented at an academic conference . Second, studies without peer review also influence the public and policy debate on GM crops; ignoring them completely would be short-sighted.
Of the studies identified through the keyword searches, not all reported original impact results. We classified studies by screening titles, abstracts, and full texts. Studies had to fulfill the following criteria to be included:. In some cases, the same results were reported in different publications; in these cases, only one of the publications was included to avoid double counting.
On the other hand, several publications involve more than one impact observation, even for a single outcome variable, for instance when reporting results for different geographical regions or derived with different methods e. In those cases, all observations were included.
Moreover, the same primary dataset was sometimes used for different publications without reporting identical results e. Hence, the number of impact observations in our sample is larger than the number of publications and primary datasets Data S1.
The number of studies selected at various stages is shown in what is savings and investments flow diagram in Figure 1. The number of publications finally included in the meta-analysis is Table S1.
Effect sizes are measures of outcome variables. We chose the percentage difference between GM and non-GM crops for five different outcome variables, namely yield, pesticide quantity, pesticide cost, total production cost, and farmer profits per unit area. Most studies that analyze production costs focus on variable costs, which are the costs primarily affected through GM technology adoption.
Accordingly, profits are calculated as revenues minus variable production costs profits calculated in this way are also referred to as gross margins. These production costs also take what are the best mens winter boots account the higher prices charged by private companies for GM seeds. Hence, the percentage differences in profits considered here are net economic benefits for farmers using GM technology.
Percentage differences, when not reported in the original studies, were calculated from mean value comparisons between GM and non-GM or from estimated regression coefficients. Since we look at different types of GM technologies different modified traits that are used in different countries and regions, we do not expect that effect sizes are homogenous across studies. Hence, our approach of combining effect sizes corresponds to a random-effects model in meta-analysis .
To explain impact heterogeneity and test for possible biases, we also compiled data on a number of study descriptors that may influence the reported effect sizes. These influencing factors include information on the type of GM technology modified traitthe region studied, the type of data and method used, the source of funding, and the type of publication.
All influencing factors are defined as dummy variables. The exact definition of these dummy variables is given in Table 1. Variable distributions of the study descriptors are shown in Table S2. In a first step, we estimate average effect sizes for each outcome variable. To test whether these mean impacts are how to increase the list level in powerpoint 2013 different from zero, we regress each outcome variable on a constant with cluster correction of standard errors by primary dataset.
Thus, the test for significance is valid also when observations from the same dataset are correlated. We estimate average effect sizes for all GM crops combined. However, we expect that the results may differ by modified trait, so that we also analyze mean effects for HT crops and IR crops separately. Meta-analyses often weight impact estimates by their variances; estimates with low variance are considered more reliable and receive a higher weight .
In our case, several of the original studies do not report measures of variance, so that weighting by variance is not possible. Alternatively, weighting by sample size is common, but sample sizes are also not reported in all studies considered, especially not in some of the grey literature publications. To test the robustness of the results, we employ a different weighting procedure, using the inverse of the number of impact observations per dataset as weights.
This what county is halethorpe md in avoids that individual datasets that were used in several publications dominate the calculation of average effect sizes. In a second step, we use meta-regressions to explain impact heterogeneity and test for possible biases. Linear regression models are estimated separately for all of the five outcome variables: is the effect size percentage difference between GM and non-GM of each outcome variable h for observation i in publication jand is a vector of influencing factors.
Influencing factors used in the regressions are defined in Table 1. Distributions of all five outcome variables are shown in Figure S1. Table 2 presents unweighted mean impacts. As a robustness check, we weighted by the inverse of the number of impact observations per dataset. Comparing unweighted results Table 2 with weighted results Table S3 we find only very small differences.
This comparison suggests that the unweighted results are robust. These yield increases are not due to higher genetic yield potential, but to more effective pest control and thus lower crop damage .
The effect on the cost of production is not significant. GM seeds are more expensive than non-GM seeds, but the additional seed costs are compensated through savings in chemical and mechanical pest control. Average percentage differences between GM and non-GM crops are shown. Results refer to all GM crops, including herbicide-tolerant and insect-resistant traits. The number of observations varies by outcome variable; yield: ; pesticide quantity: ; pesticide cost: ; total production cost: ; farmer profit: Hence what does quantity mean in science is useful to further disaggregate the results.
Table 2 shows a breakdown by modified crop trait. While significant reductions in pesticide costs are observed for both HT and IR crops, only IR crops cause a consistent reduction in pesticide quantity. Such disparities are expected, because the two technologies are quite different. IR crops protect themselves against certain insect pests, so that spraying can be reduced. HT crops, on the other hand, are not protected against pests but against a broad-spectrum chemical herbicide mostly glyphosateuse of which facilitates weed control.
While HT crops have reduced herbicide quantity in some situations, they have contributed to increases in the use of broad-spectrum herbicides elsewhere .
The savings in pesticide costs for HT crops in spite of higher quantities can be explained by the fact that broad-spectrum herbicides are often much cheaper than the selective herbicides that were used before. The average farmer profit effect for HT crops is large and positive, but not statistically significant because of considerable variation and a relatively small number of observations for this outcome variable.
Table 3 shows the estimation results from the meta-regressions that explain how different factors influence impact heterogeneity.
2) PollEverywhere PollEverywhere is an audience response system which enables creating polls in PowerPoint and Google Slides. The PollEverywhere add-in for PowerPoint or the Chrome extension for Google Slides can be used to create polls and gather audience feedback by allowing people to participate in polls via internet connected devices such as smartphones tablets or laptops. Sep 26, †Ј The free Avira Antivirus gets excellent ratings from the independent labs, but it doesn't fare as well in our antiphishing test, and its browser protection only works with Chrome and Firefox.
Getting your audience engaged is the most important thing you can do when presenting. We previously published an article on Zeetings , a program that lets the audience become part of the story by using an interactive program directly from their smartphones.
Here, Farshad has reviewed ten other programs that you can use to make sure your audience becomes part of the story, instead of just listening to it.
Sometimes the biggest enemy of a presenter is doubt. One can get a bit jittery by looking at uncertain faces in the crowd. One of the best ways to find out what your audience is thinking is to use polls. Conducting live polls during a presentation session can help you gather instant feedback and fine tune your presentation on the fly to ensure you can be on top of your game.
There are a number of polling apps, devices and plugins that you can use for conducting live polls during presentations. Different polling tools provide different options, including some which even enable presenters to continuously gather audience feedback and view brief statistics as they present their slides.
If you want to use polls in your presentations like a pro, then here are 10 best polling tools to gather instant audience feedback. Presentain provides presenters with a URL that can be shared with the audience so they can follow your slides live as you present them, using any internet connected device.
Your audience can also take part in Live polls using the same URL, allowing you to not only present your slides by broadcasting them via the internet but also to instantly gather audience feedback by offering them polls. In fact, your audience can even ask you questions using their internet connected devices. PollEverywhere is an audience response system which enables creating polls in PowerPoint and Google Slides.
The PollEverywhere add-in for PowerPoint or the Chrome extension for Google Slides can be used to create polls and gather audience feedback by allowing people to participate in polls via internet connected devices such as smartphones tablets or laptops.
Furthermore, your audience can also respond to polls via Twitter. Mentimeter is an audience response system which allows presenters to create polls using multiple choice or open ended questions, polls based on a point-based system, or use dual axis or scales to gather audience feedback. Your audience will be able to cast their votes via a designated URL.
This means your audience can instantly cast their votes by using their mobile phones, tablets or laptops during a Live presentation session.
Swipe is a comprehensive presentation web app which can not only allow you to conduct polls but you can also use it as a PowerPoint alternative. With Swipe you can design your slide decks and add polls to your presentations. Like most polling systems, Swipe provides a polling URL for the audience to respond to polls. You can start using Participoll by signing-up for a free account, picking a polling URL and downloading the add-in to start adding polls to your PowerPoint slides.
Your audience will be able to respond to polls using your custom polling URL. The data gathered via Participoll is logged to your account, which means you can login anytime to your Participoll account to view audience feedback. Ask the Room requires no sign-up and you can begin your poll by going to the home page, and clicking on Start Poll. You will be provided with a custom URL to share with your audience where they can poll, and you will be able to see the result in real-time via your browser.
If you are looking for a voting system for educational purposes that comes with associated hardware clickers that your audience can use, then Activote can be a good option. ActiVote is a comprehensive polling system by which you can create polls on your computer and allow your audience to respond using ActiVote clickers. The primary use of ActiVote is for educational purposes and it can be a good option for conducting quizzes or assessing your students using various voting based activities.
ActiVote works with Windows, Mac and Linux. OMBEA is an audience response system which can be used to insert interactive slides in PowerPoint to conduct polls during presentations. OMBEA not only works with laptops, smartphones and tablets but is also compatible with remote clickers.
You can conduct polls using open ended or multiple choice questions and enable your audience to respond using remote clickers or internet connected devices. This makes OMBEA easy to use and expands the number of devices that can be instantly turned into remote clickers.
If you are looking for a clicker based polling system, which also supports clicker devices, then iClicker is an audience response system that you should look into. This clicker based polling system enables you to gather audience feedback by allowing them to poll using smartphones, tablets, or clicker remotes. ClickAPad is another comprehensive audience response system which not only provides a polling add-in for PowerPoint but also offers clicker remotes for purchase or rent. ClickAPad has a number of products that you can look into for conducting polls during your events to quickly gather audience opinion regarding a specific topic.
The tools mentioned above include both free and paid tools, with basic to advanced polling options. Whether you are a teacher, business professional, or just someone looking to conduct a survey during a live presentation, the aforementioned polling tools can help you conduct polls and fine tune your presentation in view of live audience feedback. Jack Vincent. These are really good recommendations. Let me add Meeting Pulse to the list. It works well and looks really nice.
People use it for classes and lectures because the free version allows to poll up to 50 people. Features include Ч 15 second to set up a poll Ч all popular questions types Ч works for every device Ч no need to install anything Ч very simple. Lesley Barringer. Hi Jeremy Thank you for your comment!
Ben Bradbury. Great article Farshad! Glisser is also a simple way to collect instant feedback from your audience. All web-based, nothing to download, and their polls are pushed instantly meaning you collect the maximum level of feedback from your audience. You can also share your slides and ask questions through it too. Rosie Hoyland.
Thanks for bringing this to our attention, Ben. John Dineen. Great post. I stumbled across the post while I was searching for embedded polls. It enables the participants to ask questions and follow the thread live. It includes a presenter mode for the presenter to display selected questions on the main stage. Moderation is supported. You can also push in questions from Twitter. Lots of other cool features, detailed on the product page above. Thanks for sharing this John.
Ronnie Overgoor. NorthPolls is extremely easy to operate by the chairman of the day on the stage via his or her own smartphone. Heera Malik. Leo Budrinca. Keep your audience engaged with polls, questions, private notes and live slide sharing. This is a free native app for iOS and Android. Attendees can just answer A,B,C or D. No sign up and total anonymous. Nidhi Bambalkar. And it really helps. It gets more and more difficult to keep the audience engaged while presenting.
We stick to directpoll. It is a very simple solution for real time feedback on your live stream poll. Llarry Watson.
Great blog! To get instant feedback from audience and customers, you can use feedback apps. Feedback apps are cost efficient and provide accurate results.
Soft Intelligence Data Centre has engagement apps for organizations and businesses which help in the overall growth. You must check out them once. Nice article! I just wanted to introduce you to a polling based mobile app that I developed recently, called Pollpop pollpopapp. Let me know your thoughts. I have previously used Presentain without any issues, however I recently tried it again after seeing your comment and it seems there might be a bug preventing users to log into the app.
You can try other options in the post to gather audience feedback as an alternative. Recently, I used Mentimeter for feedback after a presentation at my organization. I used emoticons representing satisfied and unsatisfied audience and conducted a Live poll and it worked out perfectly.
The whole idea is assinine. Real science shows once you are part of the group tour measurements are worthless. The audience knowing they are being viewed and measured will give answers they think you want instead of true opinions. Waste of time and money more harm then good as it will support your preconceived notions and give failed erroneous data. Its capabilities are best suited for enterprises.
It has been used for TV, radio and large conferences as well as in small group meetings. Elizabeth Keshishyan.
These are some great tools.