Pluto and its Satellites from the New Horizons Spacecraft

Pluto and its Satellites from the New Horizons Spacecraft CAROLINE MOORE AbstractThe New Horizons spacecraft has provided the first close-up study of Pluto and its satellites. Much more analysis is required of the data but the early findings have revolutionised our understanding of the Pluto system. Discoveries such as the complexity of Plutos surface, the current geological activity, the atmospheric hazes, lower-than-predicted escape rate and the largest known glacier in the solar system were completely unexpected. Plutos moon Charon has surprised with its dark red polar cap and tectonic belt and data from the smaller moons supports the hypothesis that they were formed out of the remnants from the collision that formed the Pluto-Charon binary. Introduction Since its discovery in 1930, with a semi-major axis of 39.5AU, Pluto has been considered an icy oddity. Beyond the realm of the gas giants, Pluto did not fit into any known solar system architecture until 1992 when the existence of the Kuiper Belt (30-50AU from the Sun) was confirmed by the discovery of the first Kuiper Belt object (KBO). Now more than 1,000 KBOs have been identified, including five dwarf planets, and it is estimated that more than 100,000 objects larger than 100km orbit the sun within the belt. Its believed that the Kuiper Belt contains leftover remnants from the beginning of the solar system and that sending the New Horizons mission to explore Pluto, its moons and other KBOs would provide valuable insights into the formation of the solar system. The fastest spacecraft ever launched, New Horizons started its mission on 19 January 2006 and flew past Jupiter in February 2007 for a gravity boost which reduced journey time to Pluto by four years. It conducted a six-month-long reconnaissance flyby study of Pluto and its moons in summer 2015, culminating with the closest approach to Pluto on 14 July 2015. As well as the first mission to an ice dwarf planet, New Horizons is also the first mission since Voyager in the 1970s to an unexplored planet. The official NASA science goals for the Pluto-system exploration element of the New Horizons mission were prioritised into three categories: required, important and desired. A key goal was mapping the surfaces of Pluto and Charon with an average resolution of one kilometre (the best the Hubble Space Telescope can do is a 500km resolution) and mapping the surface composition of the various geological regions of the two bodies. Another key goal was determining the composition, structure and escape rate of Plutos atmosphere. The lower priority goals include measurement of surface temperature and a search for additional satellites or rings around Pluto. The full list of science goals appears in Appendix 1. The seven instruments on New Horizons were selected to meet these science goals. They are the most capable suite of instruments ever launched on a first reconnaissance mission to an unexplored planet (now dwarf-planet). They include an imaging spectrometer to probe atmospheric composition and planet structure; a visible and infrared camera to obtain high-resolution colour maps and surface composition maps; a long-range telescopic camera for high-resolution surface images; particle spectrometers to measure charged particles in and around Plutos atmosphere; a detector to measure masses of space-dust particles; and two copies of a radio science experiment to examine atmospheric structure, surface thermal properties and planet mass. The seven instruments are listed in Appendix 2. Although considerably more work needs to be done to analyse the data received from New Horizons it is now clear that all NASAs science objectives have been met. On 14 July 2016, the anniversary of the fly-by in 2015, NASA published Principal Investigator, Alan Sterns, top ten discoveries so far from the Pluto element of the mission. They range from the unexpected complexity of Pluto and its moons to the lower than predicted escape velocity, and the ten have been used as a focus for this dissertation. The geology of Pluto Prior to New Horizons, the best images of Plutos surface were obtained from the Hubble Space Telescope. A colour map released in 2010 isnt sharp enough to show any features, such as craters or mountains, but does show a degree of complexity and variegation with white, dark-orange and charcoal-black terrain. However, the evidence revealed by New Horizons of current geological activity was completely unexpected and the variety of landscapes on Pluto is also much greater than expected. Hummocky cratered uplands, washboard terrain (expanses of parallel ridges and troughs), chaotic blocky mountains, cellular and non-cellular nitrogen ice plains, pitted hummocky nitrogen ice plains and rugged dark highlands all feature. A prominent feature of the encounter hemisphere (EH) is Sputnik Planum (SP), an 870,000km ² oval-shaped plain on the left side of the heart-shaped Tombaugh Regio. SP is most likely composed of volatile ices Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡, CO and CHà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¾ and is the largest known glacier in the solar system. Computer simulations have been produced to show that the surface of SP is covered with icy, churning, convective cells which recycle their surfaces every 500,000 years. The modest internal heat of Pluto causes great blobs of solid nitrogen to rise up, then cool and sink back down. This helps explain why no impact craters have been observed on SP which has a crater retention age of no greater than 10 million years. Pluto and its largest satellite Charon are both tidally locked which means that one hemisphere of Pluto is locked facing one hemisphere of Charon. They both spin and orbit in 6.4 days. Data from New Horizons shows that SP is almost exactly opposite Charon: the chance of this happening randomly is 5%. It is proposed that a subsurface ocean exists under SP and that over millions of years the planet has spun around, aligning the subsurface ocean and SP above it, almost exactly opposite the line connecting Pluto and Charon. Along the west margin of SP there extends for hundreds of kilometres a discontinuous chain of mountains consisting of discrete angular blocks with apparently random orientations and sizes up to 40km across and 5km high (calculated by shadow length). Prior to New Horizons it was known that Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡, CO and CHà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¾ ices existed on the surface of Pluto, but once the images of these mountains were viewed it became clear that these ices could not support such high elevations and therefore water ices must be present. This has now been confirmed spectroscopically by New Horizons. Because water ice is buoyant with respect to N2 and CO ice, some small blocks can be carried along by convective or advective motions and larger blocks can be undermined, shifted and rotated. Because of this its possible, if the solid Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡/CO ice is sufficiently deep, that some of the smaller mountains observed may be floating within the plains, although the elevation of the l argest mountains on the western margin of SP suggests that they are most likely grounded on the basement. It is not known why there are no mountainous terrains at the eastern edge of SP. At a few locations at the eastern boundary of SP and the pitted uplands, smooth materials connect with SP along the floors of troughs 1.5 to 6km wide. High-phase imaging of the southernmost of these systems has shown clearly visible medial flow lines within the troughs, with the ice in the troughs sloping at an angle of 2-3 degrees over 50km. This implies glacial-like flow of the plains material into SP. At present it is unknown if the flowing ice carved the troughs. Cthulhu Regio (CR) is a large dark area ranging from ~ 15 °N to 20 ° S and bordering TR at 160 °E and stretching almost halfway around the planet to 20 °E . The region, comprised of a variety of geographical terrains, is covered by a thin dark mantle likely to be deposits of atmospheric Tholin. Tholin is a hydrocarbon formed by the action of sunlight on the methane in Plutos atmosphere. The methane molecules link together in progressively longer chains and as they get heavier they form a haze which eventually settles to the surface. Two broad quasicircular mounds, south of SP, might have an origin involving cryovolcanism. The smaller, Wright Mons, is 3-4km high and ~150km across, with a central depression at its summit at least 5km deep with a rim showing concentric fabric. The larger, Piccard Mons, is similar but reaches ~6 km high and 225km across. If their origin is cryovolcanic it would entail materials much stronger than Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡ ice. There are features on the EH which suggest prolonged tectonic activity. Numerous belts of aligned troughs and scarps, that can reach several hundred kilometres in length and several kilometres high, are often observed to cut across pre-existing landforms as well as branch into each other and these have been interpreted as extensional fractures in varying stages of degradation. The differing fault trends and states of degradation suggest several deformation episodes and prolonged tectonic activity. The great length of individual faults on Pluto, their scarp steepness and spectral evidence strongly suggest a thick water-ice lithosphere rather than a thin one or one made of any of Plutos volatile ices. Pluto displays a wide variety of crater morphologies and sizes vary from ~ 0.5 to 250km, not including any possible ancient basin underlying SP. Crater densities vary widely, from heavily cratered portions of CR to the apparently un-cratered SP. From the total cumulative crater size-frequency distribution its been concluded that Plutos surface, as a whole, dates back nearly to the time of the end of Late Heavy Bombardment (LHB)- perhaps 4 billion years ago. On the EH only the eastern portion of CR appears to approach the saturation crater densities expected of a terrain that has survived from the LHB itself. In contrast the water-ice mountains and the mounds mentioned previously are very young and no craters, down to a diameter of 2km, have been detected on SP. This implies a model crater retention age of no greater than 10 million years for SP and possibly much less. The atmosphere of Pluto A major goal of the new Horizons mission was to explore and characterise the structure and composition of Plutos atmosphere. Much more work is required to fully analyse the data obtained, but already understanding of Plutos atmosphere has been revolutionised. Ground based stellar occultation had shown an atmosphere around Pluto composed primarily of Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡ with trace amounts of CHà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¾, CO and HCN, with complex surface interaction and an uncertain surface pressure of ~3-60 ÃŽÂ ¼bar and a warm stratosphere at ~100K above a much colder surface (38-55K). The New Horizons trajectory allowed near simultaneous radio (using REX) and solar (using ALICE) occultations. The spacecraft passed almost diametrically behind Pluto, as viewed from Earth, with ingress near the centre of the anti-Charon hemisphere and egress near the centre of the Charon facing hemisphere. The atmospheric structure at altitudes 0 to 50km was retrieved from REX. A strong temperature inversion at both ingress and egress was found for altitudes below ~20km, consistent with measurements taken from Earth. However new evidence of horizontal variations in temperature was discovered from two notable differences between the REX profiles at entry and exit. First, the temperature inversion at entry is greater than that at exit; the derived mean vertical gradient in the lowest 10km of the inversion is 6.4  ± 0.9 Kkmà ¢Ã‚ Ã‚ »Ãƒâ€šÃ‚ ¹ at entry but only 3.4  ± 0.9 Kkmà ¢Ã‚ Ã‚ »Ãƒâ€šÃ‚ ¹ at exit. Second, the temperature inversion at entry ends abruptly at an alti tude of ~4km, marking the top of a distinctive boundary layer. The temperature inversion at exit, however, appears to extend all the way to the surface, with no evidence for a boundary layer at this location. These differences in temperature structure cannot be accounted for by night-time radiative cooling or daytime solar heating within the atmosphere because the radiative constant of Plutos atmosphere is approximately 700 Pluto days. From REX data, surface pressure has been estimated at 11  ±1 ÃŽÂ ¼bar at entry and 10  ± 1 ÃŽÂ ¼bar at exit. Analysis of stellar occultation data from 2012 and 2013 yielded essentially the same result indicating that the mass of Plutos atmosphere has not changed significantly in recent years. REX data shows that at occultation exit, temperature adjacent to the surface is 45  ± 3K: this may be indicative of a surface material less volatile that Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡ ice because a surface covered in Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡ ice would have a temperature of 37.0K to remain in vapour pressure equilibrium with the measured surface pressure of Pluto. At occultation entry, close to the region SP, the mean temperature in the lowest 4km above the surface is 37  ± 3K close to the saturation temperature of Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡. It is suggested that this layer of cold air could arise directly from sublimation of the Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡ ices in SP. Calculations have shown that it would take approximately two years for downward heat conduction in the overlying temperature inversion to establish and an inversion that extends to the ground. So the observed boundary layer would have vanished on this timescale without the resupply of cold Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡: further confirmation of SP as a sublimation source. Models indicate that photochemistry in Plutos upper atmosphere is similar to that of Titan and Triton. Methane is processed into heavier hydrocarbons by far-ultraviolet sunlight and also solar Lyman ÃŽÂ ± photons. The solar occultation results show that the upper atmosphere is much colder than previously thought. The observed Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡ opacity at high altitudes was lower than expected. The absorption of sunlight in the 57-64nm wavelength range by Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡ at high altitudes (850 to 1400km) constrains the temperature of the upper atmosphere to be approximately 70K. The mechanisms by which Plutos upper atmosphere is being cooled are not yet understood. The existence and complexity of Plutos hazes, as detected by LORRI and MVIC, was unexpected. Extensive, optically thin hazes extend to altitudes of >200km. Distinct layers are present which vary with altitude but are contiguous for over 1000km. In the highest resolution images from MVIC about 20 haze layers are resolved. The haze is unexpectedly blue, suggesting a composition of very small particles thought to be tholin-like in composition from the scattering properties observed. The layers in the haze are possibly the result of internal gravity waves driven by sublimation forcing orographic forcing. Pluto has a much lower than predicted escape rate. Prior to New Horizons the escape rate to space of Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡ was calculated to be in the region of 2.8 x 10 ²Ãƒ ¢Ã‚ Ã‚ · molecules sà ¢Ã‚ Ã‚ »Ãƒâ€šÃ‚ ¹ based on estimates of Plutos surface pressure and radius, as well as CHà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¾ and CO mixing ratios. However these calculations did not take into account the cooling of the upper atmosphere. Its now calculated that the escape rate for Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡ is 1 x 10 ²Ãƒâ€šÃ‚ ³ molecules sà ¢Ã‚ Ã‚ »Ãƒâ€šÃ‚ ¹. The escape rate calculated for CHà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¾ is 5 x 10 ²Ãƒ ¢Ã‚ Ã‚ µ molecules sà ¢Ã‚ Ã‚ »Ãƒâ€šÃ‚ ¹ which is much closer to estimates prior to New Horizons and also 500 times faster than that of Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡. If these rates for Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡ and CHà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¾ are stable over a single Pluto orbit and over the age of the solar system, the equivalent thickness of Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡ and CHà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¾ surf ace ice lost to space would be approx. 6cm and 28m respectively. This relatively small amount of Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡ loss is consistent with an undetected Charon atmosphere but appears to be inconsistent with the erosional features seen on Plutos surface. This suggests that Nà ¢Ã¢â‚¬Å¡Ã¢â‚¬Å¡ escapes in the past may have been occasionally higher. The loss of methane is a suggested origin for Charons north polar red colour, involving varnishing of the winter poles over millions of years through cold-trapping and polymerisation of escaping hydrocarbons from Pluto. Charon The EH of Charon has two prominent features: a tectonic belt of ridges and canyons in the equatorial region and a dark reddish cap to the North pole. The tectonic belt is more than 200km wide in places and consists of scarps, ridges and troughs which are almost parallel. There are two long, narrow, steep-sided depressions (chasmata). Serenity Chasma is >50km wide and ~5km deep and Mandjet Chasma reaches ~7km deep. Both chasmata are similar to extensional rifts visible on several mid-sized icy satellites such as Saturns Tethys. Its assumed that the tectonic belt is the result of substantial, aligned tectonic extension of Charons icy crust. The fact that several large craters are visible on the chasmata implies that the extension is geologically old. North of the tectonic belt there is rugged, cratered terrain. Mountains of 20km can be seen in the limb profiles. The crater density at large sizes on the northern terrain implies a surface age older than ~4 billion years. The Northern hemisphere is capped by dark reddish region named Mordor Macula (MM), the extent of which does not correlate with any specific terrain boundary or geological feature. Layer This is an unusual feature because polar caps on other bodies tend to be bright, not dark, due to some kind of reflective ice or frost. Because the red-stained areas of Pluto look similar to MM it was originally thought that they might have similar origin. Its now known that Plutos red-staining is due to atmospheric tholins and since Charon has no atmosphere the origin could not be the same. Its now proposed that the tholins on Charon are made from methane escaping from near-by Pluto. The methane sticks to the winter pole where the temperature is lowest and the ultraviolet light rec eived at night is sufficient to start to link the methane molecules together. As daytime comes, the molecules are heavy enough to remain on the surface and sunlight completes the process of polymerisation to form tholins. South of the tectonic belt the surface is smoother, comprised of seemingly continuous plains named Vulcan Planum. Tectonic resurfacing is one possible origin of these plains. Areas of relatively low crater density and at least one pancake-shaped unit might imply cryovolcanic resurfacing. The spatial distribution of tectonic features across Charon is not consistent with the types of patterns predicted from tidal or de-spinning stresses. This may point to Charon having had an ancient subsurface ocean that subsequently froze producing the extensional features and possibly allowing the eruption of cryovolcanic magmas. The small moons of Pluto When the New Horizons mission was green-lighted only the dwarf planets Pluto and Charon were known. Then in 2005 the two small moons Nix and Hydra were discovered by the Hubble Space Telescope, followed by the even smaller moons, Kerberos and Styx, in 2011 and 2012 respectively. It had been expected that New Horizons would detect additional satellites but no other moons larger than approx. 1.7km in diameter are present at orbital radii between 5,000 and 80,000km. The general hypothesis is that Pluto and its satellites were produced by the collision of Pluto with a similar Kuiper Belt object and it was hoped that New Horizons would provide information on whether this was the case. Several findings have helped to reinforce this hypothesis. First, the small moons are highly elongated, suggesting they formed and grew by the agglomeration of small objects, but, due to their size, their gravity was not sufficient to pull the material into a spherical shape. Indeed, from New Horizons images Kerberos appears to have a double-lobed shape suggesting the merger of two bodies. The shapes are consistent with the hypothesis that they all formed in the remnant disk produced by the collision that formed the Pluto-Charon binary. Second, it has been found that all four satellites have high geometric albedos, ranging from 0.56  ± 0.05 to 0.83  ± 0.08. In contrast, the majority of small KBOs have geometric albedo of ~ 0.1. This is further evidence that the moons were formed from the remnant disk rather than being captured gravitationally from the general Kuiper Belt population. Third, 11 craterlike features have been identified on Nix, and 3 craterlike features on Hydra. Crater densities have been calculated which exceed the values found on the older regions of Pluto and Charon and suggest that the surfaces of Nix and Hydra date back to at least 4 billion years ago. This fact again supports the formation hypothesis. From the high surface albedo of the moons, its strongly suggested that, like Charon, they are covered with water ice. Unlike Pluto and Charon, which rotate synchronously, the small moons are not synchronous and rotate much faster than expected with rotation periods ranging from 0.43 days to 5.31  ± 0.10. In addition, the rotational poles of the small moons are almost at right angles to the common rotational poles of Pluto and Charon. These rotation speeds and axes have not been observed in other regular satellite systems and imply that tidal spinning has not played a major role in the moons rotational histories. A future study will determine whether chaos has played a part.

Competition is Great, but not Perfect :: essays papers

Competition is Great, but not Perfect In the United States today, the economy is one of the most important things to stabilize and maintain. The economy is this capitalistic nation in a way. As the economy has gone over the many years, so has the country. A good example of that is the Great Depression; everyone in the United States was doing great with the Bull Run of the market and the abundance of jobs. Then things started to change for the worst; the economy fell out with the great crash of the bare stock market and along did the people. Everything crumbled like stale bread, including people lives and families. Not until businesses rebuilt themselves and competition returned that the economy finally turned around. The country and the people, upon whose backs’ it rests finally, turned around also, pulling out of the Great Depression and returning this nation to its greatness. In the article â€Å"Competition is Great Game Plan, but not Perfect,† the author M. Ray Perryman states that the economy is doing well due to the competition between companies and firms as the title might indicate (Perryman 1). Although he states that the competition which fuels our economy has problems, like creating monopolies and companies that dominate markets, identifying them early and becoming aware of them we will be able to keep our economy on the path that it is on (1). Mr. Perryman supports this claim by using such strategies as common sense in his reasonability, relevance, and confidence by using his own voice in this successful essay. In speaking to the American public through his article, Mr. Perryman uses the rhetorical strategy of common sense and reasonability when he states such things as, â€Å"It (competition) lowers prices, enhances consumer choice, promotes innovation and forces us to use our scarce resources very efficiently† (1). This strategy works for him in because it makes a lot of sense that competition would do these things for us. Companies competing for business must always try to undercut the opponent’s prices and costs, with this more choices will be created. Another example of Perryman’s use of the common sense rhetorical strategy is when he states, â€Å"The information and technology revolution of today, which I believe to be in its infancy, is creating a wider gap between the ‘haves’ and ‘have nots’ and is likely to eliminate or greatly reduce the need for many relatively unskilled occupation (and more than a few skilled ones) over the nex t few years† (2).

Essay --

"Your father will be undergoing a triple bypass surgery. There a few minutes left before the procedure takes place and he is sent to the operating room." I could hear the doctor’s footsteps walking away rapidly. Was this real? I pinched myself to make sure of it. How could I be around the people I loved most yet feel so broken and alone? At that moment the strong scent of my father’s favorite Oscar De La Renta cologne was the only thing I could smell while holding his hand. Laying so lifeless, weak and in pain, my father looked at me while tears trickled down onto his soft cheeks. All night, the aroma followed me as a shadow everywhere I went. Starting to take in the smell, I slowly began enjoying it and the comfort it brought me. As I waited anxiously, I was preparing myself for the worse. Hours passed and nothing, just a silent hospital and a closed door with no sign of anyone. Yet, the only thing there in the air surrounding me was the scent of the cologne and it wou ld be for the next few hours, days and weeks of the emotional journey ahead of me. Being a first generation Amer...

A Short Analytical Paper of Abraham Lincoln’s “a House Divided” Essay

The House Divided Speech was addressed by Abraham Lincoln on June 1958. He delivered the speech upon his acceptance of Illinois Republican Party’s nomination as the senator of the state. Thus the speech became a very important launching campaign for his success in politics thus giving him a national limelight that saw him in the elections to the presidency in 1860.The speech primarily addressed on the issue of slavery in America. Abraham Lincoln delivered his speech aimed at establishing his strong beliefs towards the acts of slavery. The speech was also meant to point out a differentiating factor of beliefs from Stephen Douglas and the rest of the top governmental officials who seemed to practice corruption in their transactions. According to Abraham Lincoln, â€Å"A House divided against itself cannot stand†. This was the major crucial theme of Abraham Lincoln’s speech. From this important statement,Licoln meant that the American nation could not in whatever terms or state face a positive survival phase when it was composed of a state of half-slavery and half-free. He meant that only one of those two states could only exist. Thus his bold statement was that he expected that the division that existed had to cease so as to embrace success and good governance. Lincoln’s speech helped rouse to the people of America the recognition of the extent to which slavery had gone. Lincoln’s speech is still relevant in this 21st century in that even today, each nation should embrace unity in all its undertakings whether political, social and economic. He believed that the ideals of a nation with freedom for all could not have a chance of coexistence whether socially, morally or in legal terms under one nation. Thus slavery should either be accepted among all people or be universally denied. A universal truth is clearly bears a clear significance from Lincoln’s statement to the extent that such a statement even pervades a lot of importance to the modern society and even the governments in power today. Such relevance can be clearly seen in the experiences in Sudan. Continued irreconcilable differences in culture and religion against the people of Sudan saw Southern Sudan seceding to become the republic of South Sudan. Such success for secession bears credit from the prophetic work of Abraham Lincoln. A division had always existed between the people from Northern Sudan who were associated with Muslim religion and the people from the Southern Sudan who were associated with Christianity. This scenario bred a situation of ethnic and cultural differences between the two states to the extent where secession could be avoided. Even today, the American nation is still faced with challenging political divisions and differences especially between the parties of the Republicans and the Democrats. The unwillingness of the two parties to arise to compromised solutions has always been evident in most of the major recent crises facing the nation. Clear evidence is the recent crisis on the debt ceiling where the Republicans were on the favor of maintaining cuts on spending as opposed to the Democrats who were advocating for an increase in taxes so as to increase revenue collection in the country. Further differences saw a compromised situation of debt ceiling being arrived at as the solution. This led to the country facing an economic disaster as a result of the oppositions from the two strong political parties. In the recent world, the institution of marriage can be compared to the speech of Abraham Lincoln. Marriage is a union of two people who are bound to each other by law. Division is prone to occur in a marriage situation in case of a divorce. For the married partners to embrace endured togetherness and unity in their marriage, they must appreciate common interests of concerns in their practices. In case one of the partners dissent from the unity and togetherness set up, the marriage is susceptible to division brought about by breaking of the legal bonds that hold the marriage partnership in unison. Continued lack of an amicable compromised solution between the two conflicting partners will thus lead to separation. Continued separation will see the two partners seek a divorce in a court of law and the marriage will fail completely. Most marriages nowadays are failing as a result of continued disagreements of interests between the married couple. As per words of Lincoln that a divide house cannot stand, thus the divided marriage partnership cannot even endure survival thus it breaks up. Even today, divisions in groups have been as a result of continued differences among the uniting groups. Humans have a tendency to incline towards the protection of their interest’s aid favors of their perceived groups. Such favourism makes them advocate fully for their interests posing a challenging opposing side to the interests of their unperceived groups. Many nations today are faced with such opposing groups having differing interests and ideals. People advocating for similar ideals tend to create strong ties of loyalty and even alliances creating a boundary to the opposing group or alliance. The existence of the two opposing groups as a whole sees each group maintain conflicting interests. Continued disagreement leads to one group conquer the other resulting to a failing side and a winning side. Ultimately such results create division in the nations. Thus, Abraham Lincoln’s works from the speech â€Å"A House Divided† bears a lot of significance and relevance in our modern world.

Mehta Daryush PhD Thesis Proposal FINAL

Dimmitt D. Delivery, PhD, University of South Carolina, whose areas of expertise are in the acoustic analysis of voice and the development of laryngeal high-speed videophones. The proposal, which is enclosed, was favorably received by the Committee, and we approved the scientific content and proposed work as being suitable for a PhD thesis. All of the above members of the Committee have agreed to serve on the Thesis Committee. Sincerely, Joseph S. Propeller Thesis Committee Chair Robert E. Hillman, PhD Thesis Co-Supervisor Once: Thesis Proposal Supervisor Agreements Reader Agreement Thomas F.Squattier, Sad PhD Thesis Committee Members 1 . Joseph S. Propeller, PhD (Chair) a. Title: Senior Research Scientist, Speech Communication Group, Research Laboratory of Electronics, Massachusetts Institute of Technology b. Major Discipline: Sensory-motor control of speech production c. Justification: Dry. Propeller fills the role of Chair as a non-supervisor and senior researcher at MIT. Dry. Per keel offers a wide knowledge range from voice and speech production to speech acoustics and motor involvement in pathological speakers. 2. Robert. E. Hillman, PhD (Co-Supervisor) a.Title: Co-Director/Research Director, Center for Laryngeal Surgery and Voice Rehabilitation, Massachusetts General Hospital; Associate Professor, Harvard Medical School; Faculty of Harvard-MIT Program in Speech and Hearing Bioscience and Technology b. Major Discipline: Voice function assessment c. Justification: Dry. Hillman is co-adviser and supports the clinical aspects Of the thesis project. The proposed research calls for data collection in the voice clinic and assessment of the voice production mechanisms and acoustic characteristics of human subjects. Subjects will be selected and evaluated under Dry.Hillman supervision. 3. Thomas F. Squattier, Sad (Co-Supervisor) a. Title: Senior Member of Technical Staff, MIT Lincoln Laboratory; Faculty of Harvard Program in Speech and Hearing Bioscience and Tech nology b. Major Discipline: Speech signal processing c. Justification: Dry. Squattier is co-adviser and supports the signal processing aspects of the proposed research. Dry. Squatter's work includes the speech signal processing using multimode analysis, and this work especially relates to the proposed research on characterizing vocal fold vibratory asymmetries from multimode sensor measurements. 4.Dimmitt D. Delivery, PhD (Reader) a. Title: Associate Professor, Department of Communication Sciences and Disorders, University of South Carolina; Director, USC Voice and Speech Laboratory b. Major Discipline: Voice acoustics and laryngeal high-speed videophones c. Justification: Dry. Delivery's areas of expertise are in the acoustic analysis of voice and laryngeal high-speed videophones. Dry. Delivery is a world-leader in the development of high-speed video camera technology for clinical voice assessment. Massachusetts Institute of Technology Harvard-MIT Division of Health Sciences and Te chnologySpeech and Hearing Bioscience and Technology Program proposal for Thesis Research in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Title: Investigating the impact of in vivo human vocal fold vibratory asymmetries: Co-variations among measures from laryngeal high-speed videophones, acoustic voice analysis, and auditory-perceptual voice assessment of sustained vowel phonated Submitted by: Darkish Meat 70 pacific street, Apt 516 Cambridge, MA 02139 Signature: Subtract: Signal Processing Date of Submission: Expected Date of Completion: November 25, 2008 July 2009Thesis Co-supervisors: Location of Research: Center for Laryngeal Surgery and Voice Rehabilitation, Massachusetts General Hospital Abstract: Voice specialists make critical diagnostic, medical, therapeutic, and surgical decisions by coupling visual observations Of vocal fold tissue motion with auditory-perceptual assessments of voice quality. The details of the relationship between vocal fold tissue motion and the acoustic voice signal are not fully understood, and there is recent evidence that the acoustic impact of visual judgments of vibratory asymmetry may be overestimated during clinical voice assessment.A series of three descriptive studies is proposed to systematically describe the co-variations among measures of vocal fold vibratory asymmetries and visual-perceptual judgments, acoustic voice properties, and therapeutically ratings. First, recent findings describing co-variations be;en subjective visual judgments and basic objective measures of vocal fold vibratory asymmetry in subjects with and without vocal pathologies will be validated with automated algorithms.After replicating these results, image-based measures will be further refined to consider additional dimensions in the left-right and anterior-posterior planes f the images. Second, it is proposed to apply the developed objective measures of asymmetry to voice data from a new subject population with vocal pathologies that will be evaluated using a state-of-the-art system for laryngeal high-speed videophones. The new system will enable the validation Of hypothesized relationships between vocal fold vibratory asymmetry measures and objective acoustic voice measures at unprecedented temporal resolution.Preliminary work has revealed mild co-variations between average values of vocal fold vibratory asymmetry and traditional acoustic perturbation assure, and new acoustic correlates of vocal fold vibratory asymmetries will be explored using knowledge of their effects on voice production. Third, an initial study is proposed to characterize the influences of vocal fold vibratory asymmetry on the auditory perception of voice quality. This study more directly addresses the clinical reality that voices are assessed by relating vocal fold tissue vibratory patterns to the voice quality of a patient during a standard examination.Voice specialists make critical diagnostic, medical, therapeuti c, and surgical decisions based on coupling visual observations of vocal fold tissue motion With auditory-perceptual assessments of voice quality (Zestiest et al. , 2007). While clinical experiences indicate that this approach is generally valid, it is inherently limited to case-by-case observations, and the details of the relationship be;en vocal fold tissue action and the acoustic voice signal are not fully understood.Recent evidence indicates that visual judgments of vocal fold vibratory patterns may not adequately reflect changes in objective measures of the acoustic signal (Haven et al. , 2003). Furthermore, â€Å"[t]he anecdotal reports and stroboscopic findings of a prevalent typical amount of asymmetry cause a concern, in that it may indicate an increase in overreactions of laryngeal pathology' (Shaw and Delivery, 2008).The overall goal of this project is to better understand the relationship between vocal fold tissue motion and the acoustic characteristics f the glottal vo icing source so that clinical methods for assessing voice production can be improved. This work is made possible by recent advances in high-speed digital imaging, which provides adequate sampling for detailed intra- and inter-cycle comparisons between vocal fold tissue motion and the concomitant acoustic voice waveform.A series of three descriptive studies is proposed to systematically describe the co-variations among traditional and more advanced measures of vocal fold vibratory asymmetry and their impact on visual judgments, acoustic voice properties, and auditory-perceptual tings. First, it is proposed to replicate and improve upon recent findings describing co-variations between subjective visual judgments and basic objective measures of left-right vocal fold vibratory asymmetry in subjects with and without vocal pathologies (Bonham et al. , AAA; Bonham et al. Bibb). After validating the baseline co-variations with more automatic algorithms for computing left-right asymmetry, th e image-based measures will be further developed and optimized based on the visual judgments Of vocal fold vibratory asymmetry in both the left-right and anterior-posterior dimensions. Second, the developed objective measures of asymmetry will be applied to voice data from a new subject population exhibiting vocal pathologies who will be evaluated using a state-of-the-art system for laryngeal high-speed videophones.The new system will allow for the validation of hypothesized relationships between vocal fold vibratory asymmetry measures and objective acoustic voice measures at unprecedented temporal resolution. Preliminary work has revealed mild cavitations between overall values of vocal fold vibratory asymmetry measures and traditional acoustic perturbation measures. Acoustic correlates of vocal fold vibratory symmetries will be explored using knowledge of their effects on voice production. Third, an initial study is proposed to characterize the influences of vocal fold vibratory a symmetry on the auditory perception of voice quality.This study more directly addresses the clinical reality that voices are assessed by relating vocal fold tissue vibratory patterns to the voice quality of a patient during a standard stroboscopic examination. 1. 2 Thesis proposal structure This thesis proposal is organized as follows. First, Section 2 outlines the three specific aims and associated hypotheses of the proposed investigation, along tit a timeline of goals. Section 3 continues with background information on voice production mechanisms and reviews relevant research studies characterizing vocal fold vibratory asymmetries and the acoustic voice signal.Section 4 introduces work that investigated the co-variations between a preliminary measure of vocal fold vibratory asymmetry and traditional acoustic perturbation measures. Section 5 follows with the research design and methods for the three studies proposed. F-anally, Section 6 concludes with information regarding the use of humans as subjects in these studies. 2 Specific Aims A series of three studies is proposed to investigate the influence of vocal fold vibratory asymmetries on the acoustic voice signal.Specific aims and associated hypotheses of these studies are detailed below. 2. 1 Aim 1: Investigate co-variations between visual judgments of vocal fold vibratory' asymmetry and objective measures of vocal fold vibratory asymmetry in subjects with and without vocal pathologies Aim 1 proposes to validate and improve upon recent findings describing co- variations between subjective visual judgments and objective image-based measures of left-right vocal fold vibratory asymmetry in a subject population thou vocal pathologies.The recent findings have documented moderate correlations between visual-perceptual ratings and a basic objective measure of vibratory asymmetry of the left and right vocal folds (Bonham et al. , AAA). Completely automated image-based measures of asymmetry will be developed to rep licate the published co-variations with visual ratings on the same data. After validating the automated algorithms for computing asymmetry measures, the image-based measures will be refined and optimized with respect to the peculiarities judgment data to improve pond the baseline co-variations in subject populations with and without vocal pathologies.It is hypothesized that the new image-based measures of vocal fold vibratory asymmetry will co-vary with visual asymmetry judgments to a higher degree than previous image-based measure because of the ability to capture and integrate more temporal and spatial information from the image data. Acoustic voice signal in subjects with vocal pathologies Aim 2 proposes to apply the developed objective measures of asymmetry to voice data collected from a new subject population with vocal pathologies hat will be evaluated using a statute-the-art system for laryngeal high-speed videophones.The system will allow the validation of hypothesized relat ionships between vocal fold vibratory measures and objective acoustic voice 8 measures, on an average and frame-by-frame basis. Preliminary work has revealed mild co-variations between average values of vocal fold vibratory asymmetry and traditional acoustic perturbation measures (jitter, shimmer, and harmonics-to-noise ratio). As a result, these measures will be applied to a larger subject population and explore new acoustic correlates of vocal fold vibratory asymmetries using knowledge of voice production mechanisms.

Argumentative Essay: Should Organs Be Sold or Donated Essay

For over centuries mankind have been suffering from organ failure. Even since before B.C., the organ transplant is widespread (History.com Staff, 2012). As a result of the improvements of this procedure to be more safer and ubiquitous, nowadays there are less patients with transplant rejection. It is a known fact that people are more likely to need a transplant than donating bodily parts. The British Government highlights an average of 18 people die each day waiting for transplants that cannot take place because of the organ shortage. Unfortunately, this number is increasing (Clark and Clark, 2013). 90% of the UK citizens believe in organ donation but only 30% of this number had actually taken action by registering for organ donation (Clark and Clark, 2013). It is proven that in general, the system in most nations fails to decrease the number of people who are on the waiting list, suffering each day. Therefore, the government should take precautions in trying new developments in order to change this situation. Currently, there is a debate on whether organs should be donated or legalizing organ selling. This essay would give a close look between the pros and cons of both sides, showing that a well regulated organ trade might work more efficiently than the other. All of the religions support living or deceased organ donation and even sometimes encourage people while some of them leaves the decision to individuals (NHS Blood and Transport, 2005). The reasons for most religions to accept the idea of organ donation are: 1) it will help the recipient with positive assurance 2) it does not cause damage to the donor 3) the donor can donate the organ or tissue willingly and without commercial profit. (Budiani and Shibly, 2006). According to these reasons, a compromise can be seen with some ethical compensations for donation in order to find a benefit for the patient. Pope John Paul II indicates †buying and selling human organs violates the dignity if the human.† (Friedman and Friedman, 2006). When it has been looked closely in more patients interest, it can be seen a support has been given to donation; however, because of the moral issue of giving a price to human body, the same support cannot be given for legalizing the trade and finding a matching donor for people in a  shorter period of time. Despite the fact that there is a significant increase in organ donors, the number of people are on the list is rising with a bigger proportion which indicates that a patient on the waiting list will wait longer than it used to be (Cohen, 2006). For a person who is fighting a problem with malfunctioning an organ, every second is important. These people are constantly in pain and every passing second red uces their chances (Friedman and Friedman, 2006)†¦ Every religion is against leaving people in misery for such a long time while the pain can be eased. Selling organs would take less time to find a compatible donor and patients would spend less time in misery. For example, patients with kidney failure are suffering everyday while they are trying to live with dialysis. It causes not only physical and psychological pain but also economical obstacles (Peers, 2007). The thought of people with financial means further exploiting underprivileged people and leaving them suffering is rather unethical. It brings out the possibility of poor man can experience injustice in the future due to lack of organs with a chance of not gaining enough money they predicted they would. Certain patients may suffer from fatigue and other debilitating symptoms associated with patients with only one functioning kidney. This means people’s health would be in danger for a minor benefit (Ang, 2007). Even though this might cause a problem in the future for the people who sell their bodily parts, the black markets are still currently available. The same complication might come up to the surface although it is illegal and it has been highly regulated (Scheve,2008). It is almost impossible to fully exterminate this black marketing but making it legal and giving the control of this trade to licensed professionals to evaluate donor-patient compatibility will help taking the organs and tissues out without any safety risk for the donor (Peers, 2012). It is an undeniable fact that if there is a market, the majority would want to profit while saving someone else’s life. However, the waiting list will not disappear but according to the predictions, it will surely reduce the number of people on the list. Additionally making this as a legal trade, it would prevent desperate patients from being cheated or from paying more money than they might have to when possessing from the black market (Peers, 2012). Iran proves these provisions. Even though it’s system have been criticised by many experts, their system works under the  state’s regulation and non-profit organisations as CASKP and the Charity Foundation for Special Diseases which facilitate the process by helping the trade and are checking the eligibility as well as ensuring a fair commerce (Dehghan, 2012). Many will protest that an organ market will lead to exploitation and unfair advantages for the rich and powerful. People are only considering the benefits of rich people would get. But these are the characteristics of the current illicit organ trade (Gregory, 2011). Living people can donate part of the lung, liver, intestines, or pancreas. Even though there is some financial pressure on people who wants to sell their organs, in the end it is a choice which has been given by free will. It would improve the financial stability of many. The wealthy would not be the only ones benefitting (Libertarian Jew,2013). To conclude, due to the length of this essay only major aspects of both sides can be considered. Donation would be more ethical and fair compared to selling but sometimes in order to save a patient’s life only medical ethics can be fallowed. During this essay, the ethical issues which refuses the legalization of trade market was actually due to religious beliefs. The medical ethics would be only giving the best treatment and health care to the general public. Selling would also decrease the poverty and the misery of donor-recipient respectively. If it is controlled a trading market might give benefits to both sides. REFERENCES: Ang, A (20 March 2007) Selling One’s Organs: The Pros and Cons, Retrieved from: http://voices.yahoo.com/selling-ones-organs-pros-cons-243748.html [Accessed at 2 March 2014] Budiani, D. Shibly, O. (October 2006) Islam, Organ Transplants, and Organs Trafficking in the Muslim World: Paving a Path for Solutions, Retrieved from: cofs.org/home/wp-content/uploads/2012/06/Budiani_and_Shibley.doc [Accessed at 1 April 2014] Clark, M. Clark, T. (13 June 2013) Selling Your Organs: Should it be Legal? Do You Own Yourself?, Retrieved from: http://www.forbes.com/sites/marciaclark/2013/06/13/selling-your-organs-should-it-be-legal-do-you-own-yourself/ [Accessed at 2 March 2014] Cohen, E. (June 2006) Organ Transplantation: Defining The Ethical and Policy Issues, Retrieved from:https://bioethicsarchive.georgetown.edu/pcbe/background/staff_cohen.html [Accessed at 1 April 2014] Dehghan, S.K. (27 May 2012) Kidneys for sale: poor Iranians compete to sell their organs, Retrieved from: http://www.theguardian.com/world/2012/may/27/iran-legal-trade-kidney [Accessed at 28 March 2014] Friedman, E.A. Friedman, A.L. (15 February 2006) Payment for donor kidneys: Pros and cons, Retrieved from: http://www.nature.com/ki/journal/v69/n6/full/5000262a.html [Accessed at 17 March 2014] Gregory, A. (9 November 2011) Why Legalizing Organ Sales Would Help to Save Lives, End Violence, Retrieved from: http://www.theatlantic.com/health/archive/2011/11/why-legalizing-organ-sales-would-help-to-save-lives-end-violence/248114/ [Accessed at 17 March 2014] History.com Staff (21 February 2012) Organ Transplants: A Brief History, Retrieved from: http://www.history.com/news/organ-transplants-a-brief-history [Accessed at 2 March 2014] Libertarian Jew (17 April 2013) Making a Case for Legalizing a Market in Human Organ Sales, Retrieved from: http://libertarianjew.blogspot.co.uk/2013/04/making-case-for-legalizing-market-in.html [Accessed at 17 March 2014] NHS Blood and Transport (February 2005) General leaflet on religious viewpoints, Retrieved from: http://www.organdonation.nhs.uk/how_to_bec ome_a_donor/religious_perspectives/index.asp [Accessed at 24 March 2014] Peers, R. (16 November 2012) Pro/Con Selling Organs, Retrieved from: http://prezi.com/ujelpfbdbe5u/procon-selling-organs/ [Accessed at 2 March 2014] Scheve, T. (7 May 2008) How Organ Donation Works, Retrieved from: http://health.howstuffworks.com/medicine/modern-treatments/organ-donation.htm [Accessed at 28 March 2014]

The Influences of Culture On Learning and Assessment Among Native Article

The Influences of Culture On Learning and Assessment Among Native American Students - Article Example The author cites information from the national data sources regarding the achievement of the Native American students, and he discusses the principles of assessment and the cultural aspects of assessment. He further uses personal experience to assist others in the reflection of cultural aspects of assessment. Assessment information, data gathered nationally on Native America and educational research is seriously limited. There is a lot to be learned about the Native Americans and other minority students’ assessment and external influences such as environment, context, perspectives culture, and attitudes. Priorities differ in different societies and they influence what the children learn and take as important; there is plenty of opinions and limited research that support this argument. The author concludes by giving several considerations that have to be taken into account in the assessment of a Native American student. An example of such a consideration is the language of inst ruction and the language of home. The article is important because it provides information about the culturally-based curriculum for the Native American students. Three points of relevance; (a) it provides limelight into the present assessment of native students, (b) it attempts to show that the current assessment may be biased because it fails to take into account the influence of culture on the understanding of the world, variety of intelligence we possess, the learning context and the individual’s experiences and, (c) few studies have shown that culturally-based curriculum actually increases the achievement of native students.