Sustainable Housing Dissertation Essay Example | Topics and Well Written Essays - 1000 words

Sustainable Housing Dissertation - Essay Example People in the United Kingdom have received many benefits from sustainable housing. The United Kingdom has developed numerous green and sustainable buildings. The paper first elaborates the concept of Green Home or Sustainable housing and the need for switching to sustainable housing is been discussed. The code of sustainable homes focuses on evaluating the homes in terms of the benchmark of Building Research Establishment’s Eco homes. Various types of sustainable constructions are mentioned in the research paper. Furthermore, the paper debates on various energy resources as well as material useful for sustainable constructions. Additionally, a discussion on the proper location for sustainable building, on the basis of different parameters, is included in the paper. There many types of sustainable housing mentioned in the paper. The paper offers specific examples of Eco friendly constructions in United Kingdom. On the basis of this discussion the paper concludes that the well-b eing of future generation should be taken into consideration by the construction industry. Key words: sustainable housing, low or zero carbon houses, eco homes, carbon emission. TABLE OF CONTENT Page No. Abstract....................

Development of Modern Middle East Essay Example for Free

Development of Modern Middle East Essay The purpose of this paper is to give a synopsis of the life history and work of Muhammad, son of Abdullah, the prophet of Islam. It will also seek to address the persecutions he underwent at the hands of his own clan. Muhammad was and remains one of the most influential people the world has ever seen. He was a mortal, illiterate man who has changed world history and left an indelible mark on the history books. He was the last of the prophets and one of the few with scriptures. The scripture (Qur’an) is one of the most read and revered books on the face of the earth. His work has over one billion followers worldwide comprising people from all races, social status, sex and age. He acknowledged every prophet before him and discriminated against none (Qur’an 2:285). He was a human rights champion. In this paper Quraysh and/or Mecca will mostly refer to unbelievers in Islamic monotheism at the time of Muhammad. MUHAMMAD: BIRTH and CHILDHOOD Muhammad the son of Abdullah and the grandson of Abdul Muttalib (leader of the Quraysh tribe and custodian of al-Ka’aba) is the prophet of the Islamic religion. Muhammad was born in Mecca in the year 570 c.e. which is also known as the Year of the Elephant. This is the year that Abrahah, the king of Abyssinia (modern day Ethiopia) sent a powerful force to destroy al-Ka’aba because he viewed al-Ka’aba as a rival since it was attracting more pilgrims than his newly constructed temple in Yemen. According to history, on approaching Mecca the lead elephant of Abrahah’s convoy refused to enter the city. Then birds filled the skies stoning the army with pebbles so much so that they had to retreat in defeat. Muhammad was a descendant of Abraham through his son Ishmael. His father Abdullah died few months before Muhammad’s birth. His mother Aminah sent him the countryside to be nursed and nurtured as was the custom in Arabia. It’s believed that the children learn the qualities of self-discipline, nobility, and freedom better in the countryside than in the urban areas. It also gave them the opportunities to be speakers of eloquent Arabic spoken by the Bedouin. Aminah did not have much money to pay for the care so most of the caregivers would not take Muhammad until she met Halimah a poor Bedouin woman who became Muhammad’s nurse. One day while playing with his child peers, two angels appeared to him in human form, laid him down, opened his chest and purified his heart. For fear of what might have happened next, Halimah and her husband Harith returned Muhammad to his mother. (Britannica) Aminah died when Muhammad was only six years old. His grandfather (Abdul Muttalib) took custody of him, then two years later Abdul Muttalib fell sick and suspected he may not survive the illness, so he asked his son Abu Talib to take charge of Muhammad. Abdul Muttalib had many sons some of whom were richer than Abu Talib but he was the kindest and most respectable among his brothers. Abu Talib treated him very well and respectfully. ADOLESCENT to MARRIAGE At a young age he joined Abu Talib’s caravan to Syria. On this Syrian trip a Christian monk (Bahira) saw the signs of prophethood on him, invited him and his uncle to dine with him. He saw the prophet seal on his back and told Abu Talib to protect him from the Jews and Christians because might kill him if they realize his was the foretold prophet to come after Jesus (Qur’an 61:6) And [mention] when Jesus, the son of Mary, said, O children of Israel, indeed I am the messenger of Allah to you confirming what came before me of the Torah and bringing good tidings of a messenger to come after me, whose name is Ahmad. But when he came to them with clear evidences, they said, This is obvious magic. Muhammad was said to be a young man of unusual physical beauty and generosity of character. He was revered in Mecca due to his sense of fairness and justice that people often went to him for arbitration, hence the title al-Amin (the Trusted One). His uncle Abu Talib recommended him to Khadija to work on her caravan. He did so well that Khadija retained his service and made him the head of her caravan and proposed marriage to him through her friend. They got married when Muhammad was twenty five years old and Khadija who was forty years old. During marriage they had two sons and four daughters. The two sons both died young and only Fatimah among the daughters grew up to have children of her own. At age thirty five, Muhammad took his cousin Ali who was five at the time into his household and raised him. He later gave his daughter Fatima to Ali in marriage and it was through this matrimony that his progeny came. (Britannica) All these time although an illiterate, he was not satisfied with the spiritual lives of the Meccans. He started retreating to the mountains for meditation. He has seen, heard, and dreamed of miraculous things and beings. He maintained in his mind that there must be a supernatural being somewhere who is responsible for all these creatures. (CARM) CALL to PROPHETHOOD Muhammad continued his daily retreat in the cave on the mountain. One day, generally believed to be the night of power (Laila tul Qadr) in Ramadan at age forty in the year 610 c.e. while in the cave on mount Hira, the archangel Gabriel appeared to him in human form and asked him to recite. Muhammad told the angel that he did not know how to read but Gabriel insisted he recite the name of thy Lord (Qur’an 96:1-5) â€Å"Read! In the name of your Lord (Cherisher and Sustainer), He who created — created man, out of a leech-like clot: Read! And your Lord is Most Bountiful. He who taught (the use of) the Pen, taught man that which he knew not.† The appearance of Gabriel to Muhammad confirmed his call to prophethood which also marked the beginning of Islam, and added another important chapter to Arab and world history. Among the first converts to Islam were his beloved wife Khadija, Ali his cousin and later son-in-law, and his friend Abu Bakr. The words that Gabriel taught him became the first verses (Ayat) of the scriptures (Koran) which later developed to one hundred and fourteen chapters arranged from the longest to the shortest except the opening chapter (al-Fatiha) which is short. The Qur’an was revealed in a period of twenty three years (610-632 c.e), the first thirteen years in Mecca and last ten in Medina. Although not arranged in chronological order, the shorter chapters are the early revelations. The Qur’an is one of the most revered and read books on earth today. It is the most sacred book for the Muslims; they believe it is God’s own words (the original copy in heaven) and that Muhammad is the last of the prophets hence the other title the â€Å"Seal.† In this case Muhammad and the Qur’an are both completely beyond criticism (reprimand) in the Islamic world. The Muslims will go any length to defend both regardless of the consequences. (Britannica) EARLY DAYS of ISLAM and PERSECUTIONS For the first three years Islam had about forty followers (Muslims). Muhammad and the Muslims faced a lot of persecutions at the hands of Mecca pagans, who viewed the new faith as a threat to their polytheistic lives, and the religions of their forefathers. He was still preaching in private even after three years. He preached a lot about kindness to the poor and the weak (women and children), equality of races, equality of men and women before God. Muslims started gaining ground slowly but surely. Since Mecca frequently had visitors, the elders feared that the new faith might quickly spread if strangers started accepting it, so they had to hatch a plan to stop the spread. They continue to defend their religion but offered little new to the challenge Islam brought to them. Abu Lahab (Muhammad’s uncle) and Abu Sufyan gathered eloquent poets from the tribes and started a propaganda war. The poets coined choice phrases and recited well-crafted verses to ridicule Muhammad and call into doubt the veracity of his beliefs. Muslim converts with poetic skill began to construct rebuttals and soon there were dueling poets all over the city. People began approaching the once highly respected Muhammad in the streets shoving and asking him to perform miracles (predict market prices, turn mountains into gold, make angels appear, and etc.) like the earlier prophets did. Many Qur’an verses came down to him to answer the many challenges he faced and those that question the authenticity of the Qur’an. Muhammad frequently reminded them that he was just a mortal man and the Qur’an was his miracle. Another thing that puzzled the opponents was that Muhammad was not a poet, and his sudden eloquence and verbosity was inexplicable. The Meccans admitted to the fact that Qur’anic verses were nice to listen to and its contents were impassioned and appealing. Some clan elders began sitting outside Muhammad’s window at night to hear him reciting his beautiful verses. They enjoyed the verses and knew that those verses could not have come from even the best poet let alone an illiterate man. This continued until they shamed each other into stopping because that will mean they are encouraging Muhammad and admitting that he was on the right path. (Emerick Yahiya) He continued (Qur’an 7:194-198) speaking against asking idols for help even though the idols could not see, hear, speak, or protect themselves. These Qur’anic verses made idol worship look foolish. These assertions did not settle well with the Quraysh, so they approached Abu Talib (head of the Banu Hasim) and asked him to stop Muhammad or relinquish his protection of him so they could take care of him because he attacks their religion which was Abu Talib’s too. Abu Talib knew that to take care of him meant they wanted kill Muhammad. Remembering the promise he made to his father to protect Muhammad he politely told the clan elders that he would continue to extend his clan’s protection to Muhammad. Muhammad was preaching that slaves were equal to their masters at a time when slavery was at its height in Arabia. This alarmed the Quraysh leaders which prompted them to reason with Abu Talib for the second time, they took along an able-bodied young man (Umarah) to be Abu Talib’s adopted son in exchange for Muhammad. Abu Talib strongly rejected the offer. Meanwhile Muhammad continued his preaching and people continue converting to Islam. (Emerick Yahiya) The Quraysh elders tried a third time to reason with Abu Talib only this with an ultimatum and that was â€Å"Stop Muhammad or we will fight him and you.† Abu Talib did not want to cause trouble for his clan, called Muhammad to a private meeting and said to him â€Å"Save me and save yourself.† Muhammad politely responded his uncle by saying â€Å"Uncle by Allah, if they put the sun in my right hand and the moon in my left and ordered me to give up this cause, I would never do it until either Allah has vindicated me or I perish in the attempt.† When the response was conveyed to the clan leaders, they ordered redoubling of efforts to persecute Muslims. Abu Talib assured him of his unflinching support no matter what he preached and called the Banu Hashim and Banu Abdul Muttalib clans to swear to an oath to protect Muhammad. The Quraysh then sent Utbah, a conciliatory Arab leader to Muhammad asking him to stop preaching his religion or at least make accommodation for idol worshipping, then the Meccans would compensate him whatever he wished. Muhammad recited Chapter 32 of the Qur’an, which outlines the truth of monotheism, Allah’s purpose for creation, and the way He chooses prophets to convey His message of salvation. Utbah was convinced that Muhammad was not crazy and that he should be left alone. Persecution of Muslims then increased to an alarming rate. Muslims were tortured, starved, left to die in hot desert sands, and even murdered. MIGRATION to MEDINA (HIJRA) Due to the persistent persecutions from the people of Mecca, Muhammad accepted the invitation from Yathrib (modern day Medina) to be the head of the city and arbitrator for the warring factions. He could also have freedom to practice and preach about his faith. He migrated to in the year 622 c.e. with his family and some followers. When he was leaving his house Muhammad recited (Qur’an 36:9) â€Å"We have covered them so they cannot see,† he slipped out passing unnoticed by the men assigned to kill him. He left his cousin Ali to sleep in his house. Upon arrival at Yathrib, he and his companions were welcomed with loud cry of delight; a chorus of girls sang a welcome song for them. From that day Yathrib was renamed Medina (city of the prophet). The migration is known as Hijra which also marked the beginning of the Islamic calendar. (CARM) Islam started growing rapidly as a dominant political force in Medina and Muhammad assumed the role of a de facto head of state. Both men and women (including but not limited to Safiya bint Abdul Muttalib, Asma bint Abu Bakr, and Fatima bint Muhammad) played important roles as activists and teachers to make a homeland for Islamic monotheism a reality. Many women began to vigorously support the new movement, for Islam presented a great leap forward in both women’s rights and status. Islam was now going through radical changes. The changes included opposition to idolatry, improving personal morality, establishing personal relationship with God, and regulations for public and social life. The Qur’an laid new rules for the conduct of business and commerce, the compulsory 2.5% welfare tax (Zakat) from annual savings to be given for the benefit of the poor and needy. Fasting (abstinence from worldly pleasure during daylight) in the month of Ramadan was established. The five daily prayers were now held in congregation in the mosque. (Mission Islam) With the arrival of Sawdah and marriage to Aisha, Muhammad started to establish a stable household in Medina. Sawdah was a widow of ********* and one of the early converts to Islam. She got married to Muhammad after the demise of Khadija. She was said to be a very kind and humorous woman. Aisha may have been twelve years or so at the time. She lived in her own apartment by the mosque and spent her leisure entertaining visitors and walking the streets of Medina. Aisha was a quick learner and soon became a sought-after teacher on Islamic issues as the years progressed. Sawdah also had her own apartment and did not encroach upon Aisha’s domain. She took the inexperienced Aisha under her wing and guided her in her role as a wife. (Inter-Islam) WARS against DISBELIEVERS Muhammad and his followers fought many wars against Islam’s foes from Mecca, Jews and the tribes. The first of the great wars was the â€Å"Battle of Badr.† The Muslims were outnumbered by Meccans almost three to one. The Meccan army was headed by Abu Jahl a staunch enemy of Islam and the person of Muhammad. The Meccans lost their camp and its wealth and supplies, and about fifty men including Abu Jahl and many other leaders who died in the war. The Muslims took about seventy Meccans prisoner. The Muslims had fourteen casualties. Muhammad announced that Allah’s help allowed them to win (Qur’an 8:9 and 8:17). While the Muslims continued to celebrate their win in Medina, the Meccans were humiliated by the Battle of Badr at home and wanted to revenge. This will mean a change of events for the Muslims (Qur’an 3:140) â€Å"If a wound hath touched you, be sure a similar wound hath touched the others. Such days (of varying fortunes) We give to men and men by turns: that Allah may know those that believe, and that He may take to Himself from your ranks Martyr-witnesses (to Truth). And Allah loveth not those that do wrong†. This leads to the Battle of Uhud. The Meccans used the proceeds from Abu Sufyan’s great caravan to procure weapons for next campaign against Muslims. They had three thousand well-armed fighters divided into three massive columns. The women’s group was led by Hind, Abu Sufyan’s wife who vowed not to mourn the deaths of her father, brother and uncles, and also promised not to sleep with her husband until she had her vengeance against the Muslims. Abu Sufyan trying to convince his wife of his own bravery also promised not to bathe until he defeated Muhammad. Many women decided to come along to encourage their husbands and fathers and watch the battle. Hind, Abu Sufyan’s wife stated â€Å"We will indeed accompany the army and no one can stand in our way or force us back into our homes, if the women were present at the Day of Badr soldiers running away would not have happened.† At the head of each Meccan regiment were men who wanted to see Muhammad dead. Among them were Khalid ibn al-Walid famous Meccan cavalry general who wanted glory and accolades. Abu Sufyan and his brother-in-law Ikhrimah, the son of Abu Jahl were seeking blood to fight for glory. The women made it clear that if their men struck down the enemy they would be embraced and w0uld spread rugs for them. If you turn your backs we will avoid you and we will never come back to sleep with you. (pbs.org) The Prophet instructed fifty archers to protect the Muslims backs and not to move from their posts until they saw the Muslims entering the enemy camp, if the Muslims were being beaten they should still stay at their posts and avoid trying to help so that the enemy could not come behind them. However, the archers left their posts allowing the enemy the chance to get behind them which caused the Muslims to be overwhelmed by the much larger enemy (Qur’an 8:27-28) â€Å"O you who have believed, do not betray Allah and the Messenger or betray your trusts while you know [the consequence]. But when he came to it, he was called, Blessed is whoever is at the fire and whoever is around it. And exalted is Allah, Lord of the worlds.† The Prophet himself got struck by a thrown rock that knocked one of his teeth off and he fell to the ground. He was quickly surrounded by Muslims to protect him from the charging Meccans. The Prophet tried to get up but fell into a pit, Ali and another man lifted him out of the pit. The Muslims suffered about seventy casualties and many others were severely wounded, and the Meccans lost hundreds. However, the Muslims admitted defeat because of high number of casualties and wounded including the prophet with regard to the size of their army . The Meccan women led by Hind enraged by their near defeat began to mutilate and deface the fallen Muslims. They cut off noses and ears and made them ornaments or necklaces moving over dead bodies like ghouls. Hind found Hamza’s dead body, ripped open his chest and chewed on his liver, fulfilling her vow. Hamza was Muhammad’s uncle and the one who killed Abu Jahl, the father of Hind. Hamza was killed by a slave whom Hind promised to set free if he killed Hamza. (Emerick Yahiya) After the battle of Uhud the Muslims position in Medina was precarious and the hypocrites capitalized on this situation to strengthen their position. Most of the tribes were now emboldened since they realize that the Muslims were not invincible. Many times, Muslims who were sent on missions got massacred and this brought about a lot of sadness among surviving compatriots. Muhammad explained the change in their fortunes as God’s way of testing their resolve and sincerity. (Qur’an 2:15 5-156). The Jews who had signed treaties with the Prophet broke the terms of the treaties and they were exiled from Medina. The Jews incited other tribes and Mecca to go to war with Muslims to wipe out Islam. The tribes and Meccans made up an army of about ten thousand fighters to attack the Muslims. The Prophet and other Muslims dug a trench at the south entrance of the city to protect Medina from the menacingly large army attack, since the other side was Mount Uhud and the back was the Jewish fortresses. The army arrived but could not enter the city of Medina so they laid siege for three weeks. This was called the siege of Medina or Battle of the Trench. This was a difficult time for Muslims because their food supply was running out and their Jewish neighbors (Banu Qurayza) had cut the food supply. However, after about three weeks in the cold desert nights the army started feeling weary. One night a raging winter storm befell the army, and the weather was so harsh that they decided to leave. (Emerick Yahiya) CONQUEST of MECCA and PASSING of the PROPHET Despite all the troubles Muslims faced, Islam was steadily growing. In the year 628 c.e the Muslims and the Quraysh signed the treaty of Hudaybiyah, and the Muslims defeated the Jews at the battle of Khaybar. In the year 629 Muhammad led a lesser pilgrimage to Mecca and Khalid ibn Walid converted to Islam. In the year 630 c.e the prophet marched unto Mecca with over ten thousand followers. They faced very little resistance from the Meccans. The prophet and the Muslims destroyed and removed all the idols that filled al Ka’aba and established prayers in the place. Abu Sufyan the last strongest Quraysh leader converted to Islam. (Emerick Yahiya) In the year 632 c.e the prophet went to Mecca with over one hundred thousand followers to perform farewell pilgrimage (hajj). This was to be his last hajj and this was where gave the farewell sermon (address), which reads O People, lend me an attentive ear, for I dont know whether, after this year, I shall ever be amongst you again. Therefore listen to what I am saying to you carefully and TAKE THIS WORDS TO THOSE WHO COULD NOT BE PRESENT HERE TODAY. O People, just as you regard this month, this day, and this city as Sacred, so regard the life and property of every Muslim as a sacred trust. Return the goods entrusted to you to their rightful owners. Hurt no one so that no one may hurt you. Remember that you will indeed meet your LORD, and that HE will indeed reckon your deeds. ALLAH has forbidden you to take usury (Interest), therefore all interest obligation shall henceforth be waived Beware of Satan, for your safety of your religion. He has lost all hope that he will ever be able to lead you astray in big things, so beware of following him in small things. O People, it is true that you have certain rights with regard to your women, but they also have right over you. If they abide by your right then to them belongs the right to be fed and clothed in kindness. Do treat your women well and be kind to them for they are your partners and committed helpers. And it is your right that they do not make friends with any one of whom you do not approve, as well as never to commit adultery. O People, listen to me in earnest, worship ALLAH, say your five daily prayers (Salah), fast during the month of Ramadan, and give your wealth in Zakat. Perform Hajj if you can afford to. You know that every Muslim is the brother of another Muslim. YOU ARE ALL EQUAL. NOBODY HAS SUPERIORITY OVER OTHER EXCEPT BY PIETY AND GOOD ACTION. Remember, one day you will appear before ALLAH and answer for your deeds. So beware, do not astray from the path of righteousness after I am gone. O People, NO PROPHET OR APOSTLE WILL COME AFTER ME AND NO NEW FAITH WILL BE BORN. Reason well, therefore, O People, and understand my words which I convey to you. I leave behind me two things, the QURAN and my example, the SUNNAH and if you follow these you will never go astray. All those who listen to me shall pass on my words to others and those to others again; and may the last ones understand my words better than those who listen to me directly. BE MY WITNESS O ALLAH THAT I HAVE CONVEYED YOUR MESSAGE TO YOUR PEOPLE. After the prophet concluded his final sermons the following qur’anic (ayat) verse was revealed to him (Quran 5:3) â€Å"This day have I perfected your religion for you, completed My Grace upon you, and have chosen Islam for you as your religion.† Muhammad died in the year 632 c.e. after a short illness two years after he conquered Mecca and destroyed the idols in al-Ka’aba. He was buried at Medina in the Mosque (Masjid Nabawi). â€Å"There is no forcing anyone into this way of life. Truth stands clear in the from error† (Qur’an 2:256) Sources Gelvin James L, (2011) The Modern Middle East- A History, Oxford University Press, New York Emerick Yahiya, (2002) The Life and Work of Muhammad, Alpha Books, Indianapolis Britannica Online Encyclopaedia- Muhammad (The Prophet of Islam). Retrieved on September 23, 2012 www.britannica.com/EBchecked/topic/396226/Muhammad PBS-islam: Empire of Faith-Profiles-Muhammad. Retrieved on September 25, 2012 www.pbs.org/empires/islam/profilesMuhammad.html Christian Apologetics and Research Ministry (CARM). Retrieved on September 30, 2012 http://www.carm.org/muhammad Inter-Islam Home. Retrieved on October 12, 2012 www.inter-islam.org/Biographies Mission Islam. Retrieved on October 15, 2012 www.missionislam.com/knowledge/zakat.htm

Assembly of Functional Cellulolytic Enzymes

Assembly of Functional Cellulolytic Enzymes In the present study, we reported the assembly of functional cellulolytic enzymes using a synthetic, cell-surface engineered yeast consortium. Trichoderma reesei endoglucanase II (EGII) and cellobiohydrolase II (CBHII) and Aspergillus aculeatus ÃŽ ²-glucosidase I (BGLI) were displayed as fusion proteins with the AGA2p C-terminus of a-agglutinin on the cell surface of the diploid yeast strain Saccharomyces. cerevisiae Y5. The immobilization of each enzyme on the cell surface was confirmed by immunofluorescence microscopy. This type of yeast consortium allowed convenient optimization of ethanol production by adjusting the combination ratios of each cell type for inducing synergy in cellulose hydrolysis. Next, the direct ethanol fermentation from steam-exploded corn stover was investigated. The optimized cellulase-displaying consortium produced 20.4 g/l ethanol from 48.4 g cellulose per liter after 72 h in the presence of a small amount of cellulase reagent (0.9 FPU/ml). These findings suggested the feasibility of the cellulase-displaying yeast consortium for simultaneous saccharification and fermentation. Currently, many technological barriers exist with respect to the economical production of ethanol from lignocellulosic biomasses [1]. In the process of hydrolyzing cellulose into soluble sugars, multiple cellulases including endoglucanase (EG), cellobiohydrolase (CBH), and ÃŽ ²-glucosidase (BGL) are required [2]. Consolidated bioprocessing (CBP), which combines enzyme production, hydrolysis, and fermentation in one step, is a promising strategy for effective ethanol production from lignocellulosic materials. Saccharomyces cerevisiae is the traditional microorganism used for ethanol production, but it is unable to utilize cellulosic materials and a saccharification process is required prior to fermentation to produce glucose [3-4]. Numerous attempts have been made to engineer S. cerevisiae strains to express cellulases by cell surface engineering for direct ethanol production from cellulose, and although various bifunctional or trifunctional cellulose-degrading strains have been const ructed, the efficiency of cellulose degradation has not been sufficiently improved [5-9]. It would appear that co-expression of all cellulolytic enzymes in a single cell resulted in relatively low expression levels of cellulases, which may have been due to the heavy metabolic burden and potential jamming of the secretion machinery [6,7,10]. Therefore, in this study, we adapted a new strategy of performing simultaneous saccharification and fermentation with a synthetically engineered yeast consortium having the desired properties of cellulolytic ability and ethanol production to reduce the metabolic burden. The development of a diploid yeast strain is another promising strategy for improving expression levels of heterologous genes and enhancing the fermentation performance of S. cerevisiae. Because diploid strains have better growth ability as well as stress tolerances compared with haploid strains, they are particularly suited for industrial applications. Previously, our group reported on the construction of an à Ã‚ °-agglutinin expression system for genetic immobilization ÃŽ ²-glucosidase I on the cell surface of S. cerevisiae Y5 (Patent No: ZL200810222897.7, CGMCC2660). This diploid robust yeast strain possessed many advantages, such as higher ethanol yield, higher resistance to ethanol, and higher physiological tolerance to inhibitors present in lignocellulosic hydrolysates. Here, we report on our efforts to demonstrate the assembly of functional cellulolytic enzymes using a synthetic yeast consortium. In this study, we demonstrated the feasibility of constructing a novel cell surface engineered diploid yeast consortium for direct ethanol production from phosphoric acid swollen cellulose (PASC) and steam-exploded corn stover (CS), an important step toward direct ethanol production from insoluble cellulosic materials. The strains and plasmids used in this study are summarized in Table S1. Saccharomyces cerevisiae Y5 used for the yeast cell surface display of the cellulolytic enzymes was a newly developed diploid strain in our laboratory. E. coli Top 10 was used as the host strain for recombinant DNA manipulation. T. reesei was purchased from CICC (China Center of Industrial Culture Collection). E. coli transformants were grown in Luria-Bertani medium (1% tryptone, 0.5% yeast extract and 1% NaCl, pH 7.0) supplemented with 100 ug/ml of ampicillin. S. cerevisiae Y5 transformants were selected and maintained on Geneticin plates (1% yeast extract, 2% peptone and 2% glucose supplemented with 600 ug/ml Geneticin) at 30 °C , were induced in YPG (1% yeast extract, 2% peptone, and 2% galactose) at 20 °C. The fermentation medium was composed of 10 g/l yeast extract, 20 g/l polypeptone and 10 g/l PASC as the sole carbon source. The à ¯Ã‚ ¬Ã‚ lamentous fungus T. reesei was cultured in potato dextrose aga r medium (2% potato extract, 2% glucose) at 27 °C. The cDNA was synthesized from mRNA by using the First-Strand cDNA synthesis kit (Fermentas). Unless otherwise indicated, all chemicals, media components and supplements were of analytical grade standard and obtained from Sigma-Aldrich (St. Louis, MO, USA). All restriction enzymes were purchased from New England BioLabs (Ltd. Beijing). Primers used for plasmid construction are provided in Table S2. Plasmid pAGA1 for over-expression of the AGA1 gene and plasmid pBGLI for cell surface display BGLI were constructed previously [11]. Plasmid pEGII for cell surface expression of the EGII (egl2) was constructed as follows. The 1194 bp DNA fragment encoding the egl2 gene without its native secretion signal was amplià ¯Ã‚ ¬Ã‚ ed with the à ¯Ã‚ ¬Ã‚ rst-strand cDNA prepared from T. reesei as the template using primer pairs egl2-For/Rev, this DNA fragment was introduced into the yeast display vector pYD1(Invitrogen) with Kpn I/BamH I. MAT terminator was amplified from pYD1 by using primer pairs MAT-For/Rev and then digested with BamH I/EcoR I to create plasmid pYD1-egl2MAT. The KanR fragment was obtained from plasmid YIP5-KanR by two-step cloning. First, the DNA fragment containing ADH promoter and KanR ORF was amplified from YIP5-KanR by PCR using the KanR-For/Rev primers and inserted into EcoR I/Apa I site of plasmid pYD1-egl2MAT; next, the ADH terminator digested with Bgl II/Nde I was also introduced into pYD1-egl2MAT. The resulting plasmid was named pEGII. For displaying the T. reesei CBHII gene (cbh2) in S. cer evisiae Y5, plasmid pCBHII was created. A 1344 bp gene fragment coding for the mature region of the CBHII was amplià ¯Ã‚ ¬Ã‚ ed using primers cbh2-For/Rev-KT and introduced into plasmid pEGII digested with Kpn I/BamH I for replacing egl2 to form pCBHII (Figure 1). Transformation of S. cerevisiae Y5 was carried out using the lithium acetate method [12]. The plasmid pAGA1 was linearized by Apa I for chromosome integration. The plasmid pYD1 was transformed into S. cerevisiae Y5 as a negative control. S. cerevisiae Y5 clones transformed with different plasmids (strain Y5/pYD1 contained plasmids pAGA1 and pYD1, strain Y5/EGII contained plasmids pAGA1 and pEGII, strain Y5/CBHII contained plasmids pAGA1 and pCBHII) were selected and maintained on Geneticin(G418) plates. Immunofluorescence microscopy was performed as described previously [13]. Immunostaining was performed as follows. Induced recombinant yeast cells expressing cellulases were harvested by centrifugation at 6000 rpm for 5 min and washed with phosphate-buffered saline (PBS). As the primary antibody, mouse anti-Xpress tag antibody (Invitrogen, R910-25) for EGII and CBHII was used at dilution rates of 1:1000. As the second antibody, Fuorescein (FITC)-conjugated goat anti-mouse IgG(H+L) (Jackson, 115-095-003) was used at dilution rate 1:200. Cells and the anti-body were incubated at room temperature. After washing the cell–antibody complex with PBS twice, cellular localizations of the cellulases were observed under a fluorescence microscope. Yeast strains Y5 and Y5/pYD1were used as control. Yeast cells were induced in YPG medium for 48 h at 20 ºC and harvested by centrifugation for 5 min at 6000 rpm, washed with distilled water. BGLI activity of strain Y5/BGLI was measured using à ¯Ã‚ Ã‚ ²-nitrophenyl-ÃŽ ²-D-glucopyranoside as the substrate according to a previously described method [14]. Endoglucanase and cellobiohydrolase activities were determined by hydrolysis of carboxymethyl cellulose (CMC) and phosphoric acid swollen cellulose (PASC), respectively. PASC was prepared from Avicel PH-101 (Fluka Chemie GmbH, Buchs, Switzerland) as amorphous cellulose. The cell pellet was resuspended in a reaction mixture of 1% CMC or 1% PASC in 50 mM sodium acetate buffer (pH 5.0) with the optical density at 600 nm adjusted to 1.0. After a reaction at 50 ºC for 30 min, the activities were determined by DNS method [15]. One unit of enzyme activity was defined as the amount of enzyme released 1 ÃŽ ¼mol reducing sugar from the substrate per minute. The abilities of the engineered yeast consortium (Y5/EGII + Y5/CBHII + Y5/BGLI) to fermentation ethanol from PASC and steam-exploded corn stover were investigated. The steam-exploded corn stover used in this study was provided by Henan Tian Guan Group Co., Ltd (Nanyang, Henan, China). The raw material was chopped to 2-3 cm size and treated in a steam-exploded vessel at 2.0 MPa for 5 min. The pretreated feedstock was dried at room temperature and directly used as a substrate without washing. The moisture content of the substrate was 8%. The composition of materials was quantitatively analyzed following the NREL Laboratory Analytical Procedure NREL/TP-510-42618 (Structural carbohydrates and lignin) (Sluiter et al., 2008)[16], as shown in Table 3. An enzyme mixture composed of equal amounts of cellulase (Sigma-Aldrich, St. Louis, MO) and ÃŽ ²-glucosidase (Sigma-Aldrich) was used. Yeast cells harboring different surface-display plasmid for EGII, CBHII, or BGLI, were grown in YPD medium a nd then transferred to YPG medium for 48 h at 20 ºC to express cellulase. Cells collected by centrifugation at 5000 rpm for 5 min at 4 ºC, washed with distilled water twice, and mixed in the adjustable ratio to a total initial cell concentration of 30 g/l wet weight to form the functional consortium. Ethanol fermentation proceeded at 30 ºC with 90 rpm in 250 ml Erlenmeyer flasks. 1ml samples of the fermentation broth were taken periodically and stored at -4 ºC until they were analyzed for sugar and ethanol content. The total sugar was determined by the phenol-sulfuric acid method [17]. Glucose was measured by HPLC (model 1260, Agilent Technologies) equipped with a Hi-Plex H column 300 mm Ãâ€" 7.7 mm) and a refractory index (RI) detector. Samples were run at a temperature of 60 ºC and a mobile phase of 5 mM sulfuric acid at a flow rate of 0.6 ml/min. Ethanol analysis was carried out using GC (model 7890A, Agilent Technologies) equipped with a flame ionization detector and a HJ-PEG column. Samples were run under the following conditions: column oven at 120 ºC, front injection port at 200 ºC, with N2 as the carrier gas at a flow rate of 4 ml/min. The expression plasmids pEGII and pCBHII (Fig. 1) were transformed into the yeast S.cerevisiae Y5 strains, respectively. All of recombinant yeast strains had a pAGA1 plasmid for integrating AGA1 into the chromosome, and the resultant transformants were designated strains Y5/EGII and Y5/CBHII (Table S1). Upon galactose induction, the proteins were expected to be secreted and interact with the Aga1p and Aga2p anchor system by using the glycosylphosphatidylinositol (GPI) anchor linked to the cell surface. To confirm displaying of EGII and CBHII on the yeast cell surface, immunofluorescence labeling of the cells was carried out using mouse anti-Xpress IgG antibody as the primary antibody. The green fluorescence of Fuorescein (FITC)-conjugated goat anti-mouse IgG was observed for strains Y5/EGII and Y5/CBHII (Fig. 2), indicating that EGII and CBHII were displayed on the cell surface, respectively. The cells harboring the control plasmids were hardly labeled with mouse anti-Xpress IgG(Fig. 2). These results suggested that two types of cellulase were successfully expressed on the cell surface of S. cerevisiae Y5 strain. As shown in Table 1, EGII, CBHII and BGLI activities were detected in the pellet fraction of strain Y5/EGII, Y5/CBHII and Y5/BGLI, respectively. The strain Y5/CBHII and strain Y5/EGII showed moderate CBHII and EGII activity (1.14 U/OD600 and 1.27 U/OD600, respectively). The BGLI activity of strain Y5/BGLI cells was relatively low, which was only 0.72 U/OD600. No enzyme activity was detected in the culture supernatant (data not shown), and the control strain without displayed enzymes exhibited less than 0.1 U/OD600 of enzyme activity. These results clearly indicated that active enzymes were displayed on the cell surface without leakage into the culture medium. Ethanol fermentation from 10 g amorphous cellulose per liter was performed using a cell combination system consisted of three cellulase-displaying yeast populations. Cells displaying EGII, CBHII and BGLI were mixed in various ratios and the produced ethanol from PASC were measured. S.cerevisiae Y5 without displayed enzymes was the control strain. A mixture of cells with EGII: CBHII: BGLI ratio of 2:1:1 produced the highest amount of ethanol (1.76 g/l) after 84 h; the yield (in grams of ethanol produced per gram of consumed reducing sugar) was 0.42 g/g (Fig. 3). A mixture of cells composed of an equal amount of each cell type produced 0.68 g/l ethanol after 84 h (Figure 3), indicating about 1.6-fold improvement of ethanol production by optimizing the cell ratio. However, a large portion of the substrate (the amount of residual sugar after 84 h hydrolysis of 10 g/l PASC was 5.5 g/l, and the sugar consumption rate was 43.3%) remained after 96 h without being hydrolyzed because the cellu lase activities displaying on cell surface were not enough for complete cellulose digestion. Simultaneous saccharification and fermentation of steam-exploded corn stover (CS) as a sole carbon source was conducted for the cellulase-displaying yeast consortium of the optimized ratio 2:1:1 in the presence of commercial cellulase (Sigma-Aldrich, St. Louis, MO) with different enzyme loadings (0, 0.3, 0.6, 0.9, 1.2, 1.5 FPU/ml). A mixture of cells was incubated in 100 ml of YP medium (20 g/l peptone, 10 g/l yeast extract) for 1 h to remove residual carbon source, and then resuspended in YP-CS medium (YP medium containing 100 g/l steam-exploded corn stover, corresponding to 48.4g cellulose per liter). As shown in Fig. 4, in the presence of 0, 0.3, 0.6, 0.9, 1.2 and 1.5 FPU/ml cellulase, 34.49, 18.71, 7.03, 2.11, 1.98, and 1.23 g/l of residual cellulose remained after 84h, respectively. Addition of 0.9 FPU/ml cellulase enabled utilization of 92.3% of the initial cellulose (Figure 4). The cellulose hydrolyzed by cellulase-displaying yeast consortium with an additional 0.9 FPU/ml cellulase was nearly the same as that by control strain S.cerevisiae Y5 with an additional 1.5 FPU/ml. These results indicate that cellulases displayed on the yeast cell surface improve hydrolysis of cellulose, although their activities were lower than commercial enzymes. Furthermore, using the optimized cell combination system, the relationship between the amount of added cellulase and final ethanol concentration was investigated. As shown in Fig. 5, in the presence of 0.9 FPU/ml cellulase, the cellulase-displaying consortium produced 20.4 g/l ethanol after 72 h, which was similar to the value (20.9 g/l) obtained by control strain in the presence of 1.5 FPU/ml cellulase (Table 2). Notably, as the ethanol yield reached 86% of the theoretical yield with 0.9 FPU/ml cellulase, the cell-surface engineered system enabled a reduction in the amount of added commercial cellulase. Hydrolysis of crystalline cellulose to glucose requires the sequential reactions of three groups of cellulases: endoglucanase, cellobiohydrolase, and ÃŽ ²-glucosidase. CBP is a one-step process where all steps occur in a single reactor and a single microorganism or microbial consortium converts pretreated biomass to ethanol with no additional commercial enzymes. The key challenge of CBP lies in choosing the optimal host to directly convert lignocellulosic materials to ethanol. In recent years, several researchers have been engaged in co-displaying multiple cellulases in a single cell for direct conversion of cellulose to ethanol [18-21]. However, the enzyme activity can be limited because of the metabolic burden [22]. Furthermore, it is difficult to control the surface expression level of each enzyme for optimal ethanol fermentation. Apiwatanapiwat et al., constructed the engineered yeast strain NBRC-5Es that co-displayed two types of amylolytic enzymes, two types of cellulolytic enz ymes (T. reesei EGII and CBHII), and A. aculeatus BGLI on the cell surface. The NBRC-5Es strain produced 1.04 g/l ethanol from 8.44 g/l of the acid-treated Avicel after 48 h of fermentation and resulted in a large portion of the substrate remaining without being hydrolyzed by the enzymes. In this study, instead of co-displaying all the enzymes in one cell, we developed a cellulase-displaying yeast consortium consisting of three types of yeast cells, each displaying different cellulases. This method allows for convenient optimization of ethanol production by adjusting the combination ratio of each cell type for inducing a synergy in cellulose hydrolysis. Diploidization is also a promising strategy for enhancing the fermentation ability of S. cerevisiae. Because polyploid yeast strains, including diploid strains, have higher cell growth rates, cell yields, and tolerances to various stresses compared with haploid strains, they are particularly suited for industrial application. Therefore, to generate an efficient â€Å"whole-cell biocatalyst† yeast strain related to cellulosic ethanol production, we selected S. cerevisiae Y5, a robust diploid strain, as the host cell based on its fermentation and inhibitor tolerance properties [23-24]. We first explored the possibility of ethanol fermentation from PASC by using the surface-immobilized yeast consortium (Y5/EGII+Y5/CBHII+Y5/BGLI). A mixture of cells at the optimized EGII: CBHII: BGLI ratio of 2:1:1 produced 1.6-fold more ethanol (1.76 g/l) than cells composed of an equal amount of each cell type. Next, the fermentation performance of yeast consortium using steam-exploded CS as the sole carbon source was further investigated. The optimized cellulase-displaying consortium produced 20.4 g/l ethanol from 48.4 g cellulose per liter after 72 h in the presence of a small amount of cellulase reagent (0.9 FPU/ml), suggesting the feasibility of the cellulase-displaying yeast consortium for simultaneous saccharification and fermentation. Although several studies have been carried out on establishing a cell-displaying yeast consortium [25-27], few reports of direct ethanol fermentation from pretreated lignocellulosic material have been published. The combined cell system describ ed here could become the basis for the eventual direct ethanol production from insoluble cellulosic materials.

Good and Evil in Good Country People Essay example -- people

Good and Evil in Good Country People  Ã‚     Ã‚   In "Good Country People" by Flannery O'Connor, the masked truth is reflected unequivocally through the reality in the story, its equal counterpart. For every good or evil thing, there is an antagonist or opposing force. Each character has a duplicate personality mirrored in someone else in the story. In the story, the names and personalities of the characters clash. The name is the mask covering the personality, which is representative of the reality aspect of each character. When Mrs. Hopewell named her daughter Joy, she was hoping for all the joy that comes with raising a child and watching the child develop a life of its own. What Mrs. Hopewell received was a disabled daughter who lived miserably at home and was the antithesis of everything her mother believed. The name Hulga is also a mask. When Joy changed her name to Hulga, Mrs. Hopewell had made up her mind that Joy "had thought and thought until she hit upon the ugliest name in any language" (O'Connor 299). Although Joy-Hulga chose the name because of its "ugly sound" and how well it suited her, she "secretly desired an inner self that was beautifully unique" (Bloom 99). The name Manley, the Bible salesman, has similar implications. The name Manley includes the word "man," but he is constantly revealed through his child-like acts such as his mumbling "was like the sleepy fretting of a child" (O'Connor 307). O'Connor also refers to him as having sweet breath like a child's and his "kisses were sticky like a child's" (307). The beginning of the story, "Good Country People," is misleading. At first, the story points to Mrs. Freeman and Manley Pointer as being good country people. According to Mrs. Hopewell t... ... the story. Flannery O'Connor portrayed both the good and the evil side of human nature. She also explored religious issues that are prevalent in today's society. The struggle between good and evil and real and hidden truths build the foundations for "Good Country People." Works Cited Bloom, Harold, ed. Flannery O'Connor. New York: Chelsea, 1986. Humphries, Jefferson. The Otherness Within: Gnostic Readings in Marcel Proust, Flannery O'Connor, and Francois Villion. Baton Rouge: Louisiana State UP, 1983. May, John R. The Pruning Word: The Parables of Flannery O'Connor. Notre Dame, IN: U of Notre Dame P, 1976. O'Connor, Flannery. "Good Country People." Literature: Reading, Fiction, Poetry, Drama, and the Essay. 3rd ed. Ed. Robert DiYanni. New York: McGraw-Hill, 1994. 297-310. Walters, Dorothy. Flannery O'Connor. New York: Twayne, 1973.   

Enhanced Formal Communications Project

————————————————- ————————————————- Memorandum TO:Accountants FROM:—– SUBJECT:Changes to SAS 115 DATE:September 30, 2011 ————————————————- Overview The American Institute of Certified Public Accountants (AICPA) was founded in 1887, the AICPA represents the AICPA represents all Certified Public Accounts (CPA) nationally regarding rules and regulations and also serves as advocate to public interest groups and other professional organizations. The AICPA develops standards regulations, educates its members on various directions, monitors and enforces compliance and ethical standards. Statement of Accounting Standards (SAS No. 115) was issued by the Auditing Standards Board (ASB); became effective for audit of financial statement for period ending on or after December 15, 2009. SAS 115 supersedes SAS 112 that had some weaknesses in its terminology, definitions and guidance for evaluating deficiencies. Benefits of the New Requirements The new requirement will establish standards rules and provides guidance on communicating matters related to your organization’s internal control over financial reporting identified on the next audit of financial statements * SAS 115 will prevent, detect and correct misstatements on a timely basis * It will provide reasonable assurance about your achievement and objectives with regard to the reliability of financial reporting effectiveness and efficiency of operations, and compliance with the new laws and regulations. Communication Upon completion of the audit, our firm will provide you with a management letter identifying the findings. * Our firm will still continue to monitor progress on all previous existing deficiencies or weaknesses from previous years. * All communications pertaining to deficiencies or weaknesses will be made available within 60 days following the completion of the report. * Our firm will provide a management letter of â€Å"no findings† for your records if no deficiencies are found. Audit is not a punishment, but in a process mechanism to help organizations have zero findings on their financial statement regardless of the size of the organization. While requirements to report in writing all deficiencies or weaknesses may take more time, it will ensure for better communication and awareness. SAS 115 allows our firm to gain insightful information to better serve you in the future and help you improve internal control by eliminating deficiencies. We thank you for continuing trust in our firm for the past three 3 years and our staff is available to answer or walk through any process that might seem challenging with the new regulations. We will schedule a meeting with the members of your finance team to go over these regulations two weeks prior to our audit scheduled date. References Anderson, B. (2007, June). The Management Letter After SAS 112. Retrieved from http://www. allbusiness. com/professional-services/accounting-tax-auditing/8900335-1. html Beichler, V. (2009, March). Communicating Internal Control-Related Matters in SAS No. 115. Tennessee CPA Journal. Retrieved from http://www. tncpa. org/journal/articles/communicatinginternal. pdf AICPA, (2010, September). Employee Benefit Plan Audit Quality Center. Statement of Auditing Standards (SAS) No. 115 Communicating Internal Control Related

How Does ACT Superscoring Affect Your Test Strategy

How Does ACT Superscoring Affect Your Test Strategy SAT / ACT Prep Online Guides and Tips Many colleges now use Superscoring for ACT scores as well as SAT scores. It’s important to know whether the schools where you’re planning to apply use Superscoring and how you can take advantage of this policy to demonstrate your best performance on the ACT. In this article I’ll give a brief overview of Superscoring and tell you what it means for you in terms of your testing plan. What is ACT Superscoring? ACT Superscoring is when colleges calculate your highest possible composite ACT score based on subscores from several different tests.They will take your highest ever score from each section and then average those scores together to arrive at a new composite score that represents your best performance. This chart shows how it might work across three test dates: English Math Reading Science Composite Test 1 30 28 31 20 27 Test 2 32 25 30 28 29 Test 3 29 23 35 25 28 Superscore 32 28 35 28 31 As you can see, this student’s composite Superscore was higher than any of the composite ACT scores for individual test dates because Superscoring combined all of the highest subscores. Superscoring benefits colleges because it puts them higher up in the rankings in terms of average scores of their admitted students.It also benefits you! If you do poorly on a section on one test date, it won’t affect you with colleges who use Superscoring, as long as you get a higher score for that section on another test date. Check the websites for the colleges where you plan on applying to see if they use Superscoring for the ACT, or take a look at this list that we’ve compiled of Superscoring schools. There are now nearly 100 schools that superscore the ACT! What Does This Mean for You? Superscoring should affect your studying strategy and registration timing for the ACT. Here are a couple of pieces of advice that you should follow if the colleges where you're planning on applying use Superscoring. Start Testing Early Superscoring means that you should definitely plan to take the ACT for the first time early in your junior year so that you can have enough time to improve your scores.If you don’t do as well on the first test, it will give you the opportunity to learn from your mistakes, and those lower scores won’t count in the long run after you take the test again. If you score very well on one section but don’t do well on one or two other sections, that means that you can focus your studying for future tests on your weak sections and not worry too much about the section you aced.Colleges will still incorporate the first score into your Superscore if it’s the best one you ever end up getting for the section. Take a look at these ACT test dates for the upcoming fall if you’re heading into your junior year so you can plan ahead. Take the ACT More than Once As a follow-up to the previous point, Superscoring definitely means you should plan on taking the ACT more than once (unless you reach your target score on the first try!). Taking the test two or three times means that you are likely to improve at least some of your subscores from test to test, especially if you put significant time into studying between test dates.Even if you manage to improve just one of your scores, that higher number is the one that will count for your Superscore. Practice Focused Studying This is probably the most essential takeaway from Superscoring.If you take the ACT and are unsatisfied with one or two of your section scores, you can direct all of your energy towards studying for those subject areas on future tests.Once you get a section score that you are happy with, you won’t have to worry about that part of the test in the future because that score (or potentially an even higher one) will become a part of your Superscore no matter what happens on the next test. The really great thing about Superscoring is that it means you can focus completely on improving weaker section scores and not worry about preventing already great section scores from decreasing. This book smells amazing. And I'm learning so much. Don’t Get Stressed! You should always take each test date seriously (you paid to register, after all), but Superscoring can take away a lot of unnecessary anxiety.Doing poorly on one test doesn’t mean you won't get into your top choice school. If you completely screw up a section of the test on one date but do well on another section, that’s also ok. With Superscoring, that one high subsection score means the time you spent taking the test was still worthwhile, and you can work on doing better on the section you bombed next time! Overview Superscoring for the ACT means that schools will calculate your best composite score by averaging all of your highest subscores across the tests you send them.Superscoring is great for you and for colleges because it reduces stress, lets you show your best possible scores, and allows schools to rise in the rankings in terms of average test scores. If you’re applying to schools that Superscore the ACT, you should: Start testing early Take the test more than once Practice focused studying Not freak out! Follow all of this advice, and you’ll be on your way to a SUPER Superscore! What's Next? Want more details about how exactly the ACT is scored? Read this articlefor an in-depth description. If you're not sure whether you should take the ACT again, take a look at this guide to help you decide. If you're trying to figure out when to take the ACT, read our guide to figure out the best test date for your circumstances.