Trace of Arsenic Essays - Natural Environment, Food And Drink, Water

Trace of Arsenic Rice is a dietary staple, especially those of certain cultures. A variety of baby foods and formulas contain arsenic, which can be harm young children because of their underdeveloped brains and bodies. High-end organic formulas and baby foods contain high levels of arsenic. Developed humans are also affected. Levels of arsenic in rice have been linked to the genetic damage in humans and can increase the risk of cancer. Arsenic mixes into organic or inorganic compounds by seeping into water supplies, traveling through the wind, or spreading through industrial use. Evidence of Harm There have been multiple health outbreaks in areas including Bangladesh and Antofagasta. These outbreaks have been led to arsenic contaminated wells which people use for drinking water. Those exposed to the drinking water in Antofagasta had higher rates of bladder and lung cancer. Arsenic caused many deaths among Antofagastans age 30 and older. Arsenic is one of the most toxic substances and has caused health effects. The Rice Connection Andrew Meharg was studying the environmental effects of arsenic in Bangladesh when a student noted that rice was being irrigated with vast quantities of arsenic-contaminated water. Rice is a dietary staple. It is used for rice flour, malt, bran, pasta, noodles, breakfast cereals, cereal bars, crackers, rice cakes and more. Rice plants took up inorganic arsenic from water and soil with dismaying efficiency: at 10 times the rate of other grains. Health Food Surprise In 2008, Meharg reported that arsenic in baby rice cereal sold in the U.K. exceeded safety levels set for drinking water by both the U.S. and the European Union. The Dartmouth researchers realized that all kinds of baby formulas and foods contained rice; many were thickened with rice starch. Although the teams initial tests found barely a trace of arsenic in baby formula and pureed baby food, later tests showed that two organic toddler formulas contained up to 60 ppb of arsenic (adjusted for dilution) six times the EPA safety limit for water. Labels on the formula canisters told why: They were sweetened with organic brown rice syrup, considered a healthy alternative to corn syrup. And while brown rice syrup is rare in baby foods, it is common in crackers, cereals, snack bars, energy bars and many products marketed as health foods. The Risks of Imported Food Almost 15 percent of foods consumed in the U.S. come from outside the country. penetration from overseas is so vast and complex that a single product might contain ingredients from multiple countries, a fact you would never discern from labeling on the food itself. Its risky. Every food factory in the U.S. is supposed to undergo rigorous inspection. Once imported foods reach our shores, they enter the distribution chain with little fanfare and scrutiny; some argue they are barely vetted at all. Instead, by and large, problems come to light when Americans get sick. Part of the problem is the lack of resources we ourselves direct to food from abroad: The FDA has a minuscule team of some 1,500 inspectors devoted to food imports, a workforce too small to screen more than a tiny fraction of the food that arrives at U.S. ports each year for microbial pathogens or other disease-causing contaminants Underwater Robots Patrol the Red Tide of Harmful Algal Blooms Concentrations of algae in our oceans and lakes have long bloomed naturally, but climate change and fertilizer runoff from farms have exacerbated the situation in recent years. The outcome: algal blooms so massive that ecosystems turn into dead zones, resource-poor realms inhospitable to other life. The most dangerous of the blooms, called harmful algal blooms, or HABs, are often reddish in color, leading observers to call them red tides. The dangers are as ominous as the name. Some of the algae, or phytoplankton, manufacture saxitoxin, a poison so devastating it is the underlying cause of paralytic shellfish poisoning, an often-lethal reaction to shellfish that are storing toxic algal cells. This January, two people in Malaysia died after eating cockles tainted with the stuff. Other phytoplankton produce domoic acid, a neurotoxin that kills people, birds and marine mammals snacking on contaminated fish and shellfish. . The fight against red tides may be taking place one algal and shellfish species at a time. Elsewhere in

Sauders 2003 Essay Example

Sauders 2003 Essay Example Sauders 2003 Essay Sauders 2003 Essay Saunders et al. 2003, p. 83 -The Research Process â€Å"Onion† Having defined the research question and the overall research design for this study, the next step is to discuss the design in more detail: the research philosophy, the research approach and research strategies used. Much literature is available on research philosophies, approaches and strategies. Saunders et al. (2003) define the socalled research process ‘onion’, consisting of five different layers, as in Figure 2-3. Part 2 As approaches in the different layers have dependencies, they suggest a research design should be developed from the top down, starting with the outside layer [adopting a research RESEARCH DESIGN philosophy] and thereafter peeling away each layer until the fifth layer is reached [defining data collection methods]. This approach, also suggested by Remenyi et al. (2000), is used in this study. Part 3 A positivistic philosophy aims at the derivation of laws or law-like gen eralizations similar to those in the physical and natural sciences (Remenyi et al. 000, p. 32). Quantitative research allows researchers to familiarize themselves with the problem or concept to be studied. The emphasis is on facts and causes of behaviour (Bogdan and Biklen 1988), with the information in the form of numbers that can be quantified, and summarized using a mathematical process for analysing the numeric data and expressing the final result in statistical terminology (Charles 1995). Part 4 The realistic philosophy shares two features with a positivism philosophy: a belief that the natural and the social sciences should apply the same kinds of approach to the collection of data and to explanation, and a commitment to the view that there is an external reality to which scientist direct their attention (Bryman 2001). Saunders et al. 2003, p. 83 The Research Process â€Å"Onion†

Benifits and Disadvantages of Coaching PowerPoint Presentation

Benifits and Disadvantages of Coaching - PowerPoint Presentation Example Knowledge gets transferred from one individual to another through the process of coaching. It is partly different from teaching in that in coaching, the tutor essentially adopts such a behavior that makes him/her the role model for the learners whereas in the course of learning, the tutor just has more knowledge about the subject as compared to the learners. He/she may not at all be involved in the subject of discussion. All that matters is the conveyance of knowledge to the learners whereas in coaching, the coach essentially tells the followers how to do a certain task. It involves display of certain characteristics that are consistent with the demand of the subject of discussion. Therefore, a coach assumes the responsibility to behave and act professionally so that he/she may rationally decide what to deliver when, how and how much. The same professionalism is inculcated in the followers as they accede to the instructions of the coach. Coaching provides the learners with an opportu nity to identify their weaknesses and discover their strengths with the guidance of the coach. Coaching is a coherent process whose various stages are sensibly linked to each other. In the initial stage of coaching, the coach tells the followers what is expected of them once they master a certain art.

Are there any reasons, beyond the purely aesthetic, for us to be Essay

Are there any reasons, beyond the purely aesthetic, for us to be interested in the sounds of animals - Essay Example There are also arguments by Rothenberg (2013) that opine humans got their notion of dance, rhythm and synchronisation from insect sounds that have surrounded them through millions of years of evolution. Essentially, animal and insect sounds have shaped human sounds. He claims that the sound of insects has acted as a soundtrack for humanity in its entire history and presently, the sounds insects and animals produce are inextricably linked with humanity. From this perspective, this paper will research on the relationship and answer the question â€Å"are there any reasons, beyond the purely aesthetic, for us to be interested in the sounds of animals?† Sound can either be audible or inaudible to the human ear. Inaudible sound is further categorised as infrasound (those below 20 hertz) and ultrasounds (those above 20 kilohertz). The human inner ear has a spiral sheet on which sound plucks synonymously to the way guitar strings are plucked and fires the brain cells that constitute the hearing parts of the brain. When the firing pattern is varied, different cell ensembles are excited and the sounds associated to past experiences, thoughts and feelings. Animal sound is natural in the sense that they are generated by the animals in their normal soundscape (Seyfarth, Cheney & Fischer, 2010). Apart from humankind having the unique ability to understand or identify with the needs most animals, listening to their sounds is one of the key ways of understanding such needs (Rothenberg, 2013). This can also be viewed from the perspective that humans know relatively little on other creatures’ sensory world but, apart from visually, they can interact with them by listening to the sounds they make. Most of the sounds and the vocalizations animals produce are specialised for communication with other animals belonging to the same species. In mammals, sound is produced in the vocal chords (larynx) while birds use a special organ known as the syrinx to produce their songs.

Assignment-Oppression-Race, Class.And Gender in United States Coursework

Assignment-Oppression-Race, Class.And Gender in United States - Coursework Example The oppressed are treated cruelly and unjustly by those who have authority over them. For example, the poor continue to be oppressed as they have no means of getting out of their predicament. Tatum (2010) defines racism as a system of advantage based on race. Based on their color, the blacks are considered inferior than the whites due to racial prejudice. They are considered as not able to achieve much of the superior race of whites have been able to achieve hence are discriminated in all aspects; they cannot get good jobs, housing, and education among other aspects. Furthermore, the whites claim their privileges and advantages are biological in nature hence not racist; it is not their fault that they are advantaged. The blacks are blamed for their predicament in most cases as they are stereotyped as not willing to improve themselves and lack initiative. According to Hubbard (2010), human sexuality is not natural but a social construction in which children are socialized from birth. Traditionally, family roles were divided according to gender type. Some roles like hunting were solely for men while others like kitchen work was reserved for women and men were regarded as superior than women. Sexism is therefore the belief that one sex (male) is superior to the other (female) hence has the right to dominate almost all aspects of life. Women are discriminated against based on their sex due to gender stereotyping. For example, even with more women acquiring similar education levels as men, women still get absorbed in the lowly paid service sector while men join highly paid sectors such as engineering. Classism refers to the differences that exist between different groups in the society such that the dominant group oppresses the lower classes (Mantiosis 2010). He asserts that the society is divided into the wealthy class, middle class and the poor and acknowledges the fact that a wide gap exists between the rich and the poor in America contrary to a

Carbon Nanotubes for Nano-particle Field Extraction Thruster

Carbon Nanotubes for Nano-particle Field Extraction Thruster Using carbon nanotubes as propellant for nano-particle field extraction thrusters Stefan Seuleanu Introduction Carbon nanotubes have been a research focus for more than two decades due to their unique physical properties and have been used so far in a variety of appli- cations. A possible application of carbon nanotubes is their use as propellant for an electric propulsion prototype, the nano-particle field extraction thruster (nanoFET). The nanoFET accelerates and ejects conductive particles in order to provide thrust1 . Its main advantage over other electric propulsion systems, such as ion or arcjet thrusters, is its variable specific impulse and thrust, while maintaining a high internal efficiency1 . Theoretically, the nanoFET propulsion system can be used for a large range of orbital and deep space exploration sit- uations, offering the possibility of decoupling the spacecraft design from the propulsion system4 . However, to date, nanoFETs have not been researched ex- tensively and much of the experimental work is still to be expected. This paper will investigate the possibility of using carbon nanotubes as nanoFET propel- lant by considering their relevant physical properties. By understanding how the nano-particle field extraction thruster works,this account also motivates the use of carbon nanotubes as propellant, despite their current high price. Properties and characteristics of CNTs Firstly, it is important to understand the relevant characteristics that make CNTs desirable for the nanoFET propulsion system. A carbon nanotube is a tubular/cylindrical structure that can be visualized as a wrapped sheet of graphene (one atom thick, two dimensional carbon based hexagonal lattice). Their size is typically a couple of nanometers in diameter and can span many micrometers in length. Carbon nanotubes can be single-walled (SWNTs) or multi-walled (MWNTs). These two characteristics will determine their aspect ratio (ratio between length and diameter), which is generally very high. As will be explained later on, the aspect ratio is a determinant factor that influences the nanoFET performance2,3 . The geometric structure of the nanotube determines its electrical properties. Based on the chiral vector (n,m), illustrated below, there are three main types of CNTs: zigzag, armchair and chiral. When n − m is a multiple of three, then the CNT is metallic, and semiconducting otherwise. Due to their geometry, armchair CNTs are always metallic, while the other types can be metallic only with the right choice of (n,m). Because there is no exact way to synthesize carbon nanotubes of only one geometry, as expected, generally one third of the synthesized CNTs are metallic and the rest are semiconducting 2,3 . Figure 1: CNT type depends on the chiral vector2 . Regarding the nanoFETs, the desired CNTs are the metallic type which implies the necessity for prior sorting before use. Moreover, the synthesized CNTs can contain geometrical †defects† that can be manipulated to improve the thruster’s performance3 . Due to the fact that the CNTs’ structure/geometry minimizes the collisions between conducting electrons, the resulting metallic tubes are highly conductive. Another characteristic is determined by the strong carbon bonds that allow high current to flow at low resistivity. This properties will become relevant when explaining the charging stage of the nanoFET 2,3 . The stages of a nanoFET The acceleration of a particle by a nanoFET can be divided into several stages. By assuming that the particles have been already sorted for the desired thrust, the first stage is the transportation of the particles to the charging pad. The transportation of the particles can be achieved either trough a dielectric fluid or through back pressure, hence the difference between wet nanoFETs and dry nanoFETs. For the purpose of this paper only the wet nanoFETs will be con- sidered, as the research done into dry nanoFETs has so far been minimal. The transportation liquid used for the proof-of-concept tests was silicon oil. After the particle is transported to the charging pad, the next stage is the charging process . Here the conductive particle is electrostatically charged to a desired level 5,6,8 . Figure 2: Single nanoFET emission channel cross section5 The next phase is the lift-off and extraction, which represents the application of an electric field, a potential bias between the electrode and the acceleration gates, such that the particle leaves the charging pad and moves upwards towards the liquid’s surface. At the surface, the particle must overcome the surface tension and get extracted from the liquid. After the extraction, the next stage is the acceleration of the particle trough several stacked gates. The gates have alternating insulating and conductive layers, each providing in theory an electric potential of 1000V, leading to a total of 10,000V potential that accelerates a particle to approximately 10km/s. The particle is finally ejected out of the nanoFET and thrust is produced5,6,7 . Particle behavior in nanoFETs In order to understand the behavior of the particle in a gravitational setting compared to a micro-gravitational setting, it is important to identify the forces that act on the particle at different stages in the nanoFET. The four main forces acting on a particle in a gravitational setting are the electrostatic force, the buoyant force, gravitational force and the drag force. As the cylindrical particle is transported to the charging pad, the liquid provides a horizontal inertial force. This horizontal inertial force is assumed to be low and therefore ignored in the calculations. After the nanoparticles are transported to the charging pad (electrode), they are electrostatically charged; thus contact with the electrode is necessary. If the contact is horizontal, along the length, then the charge of the particle is described by6 .: q0,cy−h = 2Ï€rlÃŽ µl El However if the contact is at either ends, so the particle is vertical on the electrode, the charge is the following6 .: l2 q0,cy−v = Ï€ ln( 2l ÃŽ µl El When the cylindrical particle is vertical on the charging pad, it gains more charge and it also requires less electric field to move upwards, as seen in the figure below6 . Figure 3: Vertically vs horizontal oriented particles a) ratio of acquired particle charge; b) ratio of required lift-off electric field6 In order to orient a particle from horizontal to vertical on the charging pad, an intense electric field focused only at one of the particle’s ends is applied. The fabrication defects that are usually present at the ends of CNTs may help to change the orientation of the particle on the electrode, requiring less electric field to create a moment that rotates the CNTs vertically. Additionally to the gravitational force, while still on the charging pad, the particle has to overcome the adhesion and electric image force in order to achieve vertical lift-off5,6 . After the particle leaves the charging pad, it has to move vertically trough the viscous liquid to the liquid surface. Therefore, the adhesion force and the electric image are no longer present; however the drag force now slows the particle’s movement. For a cylindrical particle the formula for the fluid drag used in the nanoFET calculations is given by6 : 2π µl lv D = ln( l ) + 0.193 While moving through the liquid, the particle loses charge as described by q(t) = q0 exp(− t ), where Ï„ = ÃŽ µl 5,6 . Because the particle moves fast through Ï„ ÏÆ'l the liquid, the charged loss is overall assumed to be negligible. Generally, the particle’s equation of motion is described by6 : dv (mp + K ml ) dt = q(t)El − D + Fbuoyant − W. The above equation also takes in account the added mass that is accelerated with the particle where K is a coefficient that depends on the geometry of the particle, while mp is the mass of the particle and ml is the mass of the liquid. In a laboratory gravitational environment the gravitational forces are minimal compared to the dominant drag and electrostatic forces. In a micro-gravitational environment the gravitational force and the buoyant force can be neglected5,6 . Performance and particle size For characterizing the performance of the nanoFET electric propulsion system, the space industry uses specific impulse and thrust-to-power ratio as indica- tors of performance. The specific impulse is the impulse delivered per unit of propellant consumed. In order to achieve a certain thrust, the systems that have higher specific impulse consume less propellant than the ones with lower specific impulse. For the nanoFET system the specific impulse increases as the charge-to-mass ratio of the particle increases. Thurst-to-power ratio describes the amount of thrust outputted for a specific power provided4,6 . 1 q 1 T 2 mp 1 Isp = 0 (2Vo p ) 2 ; = ( ) 2 P Vo q Moreover, the internal efficiency is given by4,6 : 1 T ÃŽ ·int = 2 g0 P Isp There are several factors that can influence the performance or the mode of operation of the nanoFET. First of all, the horizontal inertial force that the particle gains from the transportation liquid is assumed to be negligible. How- ever, this is not necessarily the case and further research needs to be conducted in order to determine its influence. Another important factor is the presence of Taylor cones and surface instability when a high electric field is present near the liquid’s surface. These cones can eject droplets and reduce the performance of the nanoFET. In order to mitigate the surface instability and the ejection of droplets, an experiment has been done to analyze how different particle shapes influence the minimum electric field needed for the extraction process. The ex- periment consists of various vacuum electric fields applied to spherical 800 µm and cylindrical 300 µm diameter and 1.5mm length aluminium particles with a total silicon oil fluid gap of 12 .7mm. As seen in the figure below, cylindrical particles can be extracted before the Taylor cones form5,6,7, . Figure 4: Taylor cone formation and particle extraction6 Furthermore, further study into the charge-to-mass ratio revealed that, for cylindrical particles, charge-to-mass ratio increases as aspect ratio increases. Therefore, at large aspect ratios, the needed extraction electric field decreases as seen in the following figure. For this reason increasing the aspect ratio of the particles increases in turn the Isp and the overall internal efficiency6 . A good candidate for further research are the CNTs due to their cylindrical Figure 5: Cylindrical particles’ vacuum extraction field simulations6 shape, high aspect ratio, good charge-to-mass ratio and fast charging. By choos- ing different CNT sizes to be used with variable gate potentials, the nanoFETs’ Isp range is theoretically very large compared to other electric propulsion sys- tem such as ion thrusters or hall thrusters. Similarly, the thrust-to-power varies greatly, which offers the flexibility of using the same propulsion system for mul- tiple missions or to perform unplanned trajectory changes at a low propellant expense. These are theoretically achieved while maintaining a high internal efficiency that is usually above 85%. For the following CNTs: nanoFET par- ticle1 16nm diameter, 3 µm length; nanoFET particle2 4nm diameter, 3 µm length; nanoFET particle3 1nm diameter, 3 µm length, the expected Isp and Thrust-to-Power ratio is illustrated4,5 . Figure 6: Thrust-to-power ratio for large specific impulse range4 Figure 7: Internal efficiency for large specific impulse range4 Discussion Apart from the large specific impulse range at high internal efficiency that pro- vides great flexibility to design a multitude of mission phases based on just one propulsion system and to accommodate for unforeseen scenarios, the nanoFETs have other important advantages over other electric propulsion system, such as potential longer operational lifetime, their geometric scalability and the fact that the system is highly integrated. The longer operational lifetime is due to the fact that the CNT particles or any other conductive particles are charged electro- statically and not ionized which eliminates the need for cathodes and eliminates charge exchange collisions that are the main lifetime reduction factors5,6 . However, there are still a multitude of challenges ahead until a fully functional prototype will be achieved. First of all, the experiments done so far that demon- strated particle transportation, charging and lift-off were conducted using mi- crometer size particles such a s Aluminum, Titanium and Indium. Although theoretically the CNTs can greatly increase the performance, no nano-size par- ticles have been experimentally used so far. Experimenting at the nanoscale might sometime reveal new problems that were not present at the micron level. Also, it is generally desirable that a quantitative experimental analysis is done in order to understand how a multitude of particles with different character- istics perform. In this way it could be determined what particle shows the most promise, although CNTs have a strong theoretical advantage mainly due to their charge-to-mass ratio. Another important factor to investigate is how the charging process changes as the size of the particle decreases to the several nanometers; the main concerns being conductivity and the contact area with the electrode. Furthermore, an investigation should also be conducted regard- ing the transportation liquid. So far, it is uncertain if a fully dielectric liquid is always desired over a slightly conductive liquid. Moreover, different liquids should be tested in order to experimentally understand how the viscosity of the liquid influences the space charge current5,6,7,8 . Finally, from an academic point of view it would be desirable that both the theoretical and experimental papers are published in a peer-reviewed journal. Conclusion Overall, the nanoFET propulsion system shows great promise due to its high specific impulse range and inherent scalability. Although it is a new concept, the most important processes such as particle transportation and charging have been already demonstrated. However, there are still a multitude of experiments that need to be conducted in order to fully understand the behavior of the system under a wide range of factors. Another interesting prospect for the nanoFET technology is their possible use , not only in the space industry, but also in medicine. The nanoFET technology can also be used to accelerate particles and inject them through cellular walls to deliver drugs. For these reasons, the nanoFET technology is an exciting and potentially rewarding research subject. References 1. Gohardani O, Elola CM, Elizetxea C. Potential and prospective imple- mentation of carbon nanotubes on next generation aircraft and space vehicles: A review of current and expected applications in aerospace sciences. July 2014. Elsevier. Progress in Aerospace Sciences 70 (2014): 42-68, ISSN 0376-0421, http://dx.doi.org/10.1016/j.paerosci.2014.05.002. 2. Loiseau A, Launois P, Petit P, Roche S, Salvetat JP. Understanding Car- bon Nanotubes. 2006. Springer. ISBN-I3-978-3-540-26922-9. 3. Dresselhaus MS, Dresselhaus G, Avouris P. Carbon Nanotubes: Synthesis, Structure, Properties, and Applications. 2001. Springer. ISBN 3-540-41086-4. 4. Liu TM, Musinski LD, et al. Nanoparticle Electric Propulsion for Space Exploration. 2007. American Institute of Aeronautics and Astronautics. Re- trieved from: http://pepl.engin.umich.edu/pdf/STAIF2 007.pdf on1stof J une2015. 5. Liu TM, Musinski LD, et al. Nanoparticle Electric Propulsion: Experi- mental Results. 2007. American Institute of Aeronautics and Astronautics. Retrieved from: http://deepblue.lib.umich.edu/bitstream/handle/2027.42/76874/AIAA-2006-4803- 539.pdf ?sequence=1 on 1st of June 2015. 6. Liu TM, Musinski LD, et al. Theoretical Aspects of Nanoparticle Electric Propulsion. 2006. American Institute of Aeronautics and Astronautics.Retrieved from: http://pepl.engin.umich.edu/pdf/AIAA-2006-4335.pdf on on 1st of June 2015. 7. Liu TM, Musinski LD, et al. Developmental Progress of the Nanopar- ticle Field Extraction Thruster. 2008.American Institute of Aeronautics and Astronautics. Retrieved from: http://www.umich.edu/ peplweb/pdf/AIAA- 2008-5096.pdf on 1st of June 2015. 8. Liu TM, Musinski L, Gilchrist B, Gallimore A. Electrostatic charging of micro- and nano-particles for use with highly energetic applications. 2008. Elsevier. Journal of Electrostatics. doi:10.1016/j.elstat.2008.11.001

Free College Admissions Essays: Responding to Future Challenges :: College Admissions Essays

Responding to Future Challenges    As the world grows so do our challenges. Not only are our problems growing in number but they are also growing in complexity. There is scarcely a day that goes by when I don't hear about some new problem that will soon threaten us all. While some of these problems such as El Nino, earthquakes, and other natural disasters cannot be stopped -- there are other challenges such as the spread of racial hatred, rising risk of disease spread, and the growing levels of civil unrest throughout much of the world which threaten many lives everyday. Most of the future's challenges will only be made possible if all people, regardless of race, color, or nationality, attempt to work together for a stronger world. There are many ways in which I believe that I can help society meet this future challenge of coming together as a united world.    While I was an exchange student, I saw the world from a different point of view. For the first time, I realized that the people of the world have so many similarities in comparison to the few and insignificant differences. To make the people of the world unite would merely take time in convincing people of the world that we are all in pursuit of the same basic goals. All that it would take to show that this could be done is two different cultures to unite and then the rest of the world what can come by the strength all gain by coming together.    I believe that I can help in solving some of the barriers that hold us back from completing the task that we all desire which is unity. I served as a miniature version of a diplomat when I was an exchange student. I helped people in another country see that we all have common goals and I also helped sever the bonds to racial hatred by providing them insight into the American way of thinking and they did likewise for me. I have done everything to help sever these ancient bonds and will continue to do so in the future as I feel I am called to do.    Many suffer problems on a much less grandiose scale. Although these problems may not seem to be as big as world peace or global warming, they are however present.