Causes And Effects Of Drought Stress Environmental Sciences Essay

Causes And Effects Of Drought Stress Environmental Sciences Essay Drought can be defined as the absence of rainfall and water or irrigation for a period of time sufficient to deplete soil moisture and injure plants (Plantlifeonline.net, 2007). In short, drought is a period of time without rainfall. The drought is one of the most serious global issues for agriculture field and need to harsh precaution need to be taken immediately. Four-tenths of the worlds agricultural land lies in arid or semi-arid regions especially in Africa. Meanwhile, drought stress is defined as effects of some period of plants that involve plant water relationships. According to Farooq et al. (2008) drought stress reduces and decreases the size of plants leaf, extension of stem and proliferation of roots that disturbs plant water relations and reduces water-use efficiency. While ForestryNepal(n.d.) defined that drought stress occurs when the available water in the soil is reduced and  atmospheric conditions cause continuous loss of water by transpiration or  evaporation. Drought stress tolerance can be found in almost all plants but its extent varies  from species to species and even within species. It is characterized by  reduction of water content, diminished leaf water potential and turgor loss, closure,  nutrient metabolism and growth promoters. Plants display a variety of physiological and biochemical responses at cellular and whole organism levels towards prevailing drought stress, thus making it a complex phenomenon. Based on Bishop(n.d) report, many variables play a part in reaching drought conditions, these include lack of natural rainfall, types of soil, air temperature, humidity, conditions of wind, exposure of sun, and also plant type or root depth that increase pant water loss. Drought stress can affect the growth of plants in various ways. One of the effects is the priming on seed performance of several plants due to lack of natural rainfall. For example of plant that can be affected from this problem is Canola plant (Brassica napus L.). Based on the report of Mohammadi and Amiri(2010) , Canola plant is one of the most important oil seed crops which its production has been notably extended during recent years in Iran and due to lack of rainfall at planting time and the seeds are common planted in seedbeds having unfavorable moisture. The drought stress is responsible for both inhibition and delayed seed germination and seedling establishment of Canola. Consequently, this stress adversely affects growth and development of crop and also results into low Canola yield. There is a decrease in water uptake both during imbibition and seedling establishment under this stress condition. Tutorvista(n.d.) stated that imbibitions process is the phenomenon of adsorption of water by the solid particles of a substance without forming a solution. Furthermore, inhibition of radicle also occurs due to the effect of stress condition. The inhibition emergence is mainly because of a decrease in water potential gradient between the external environment and the seeds. In addition, the seed priming has been successfully proved and demonstrated to improve germination and emergence in seeds of many crops and plants, especially under stress conditions. The seed priming is a technique that starts the germination process in the lab or plant. Moreover, the basic chemical reactions or framework for the seed to germinate and for the process to occur efficiently in the lab or plant, high moisture and ideal temperature condition are needed (Hariss, n.d.). Secondly is that the drought stress can affects the photosynthetic rate and leaf gas exchange of plants. Siddique et al. (1998) reported that, drought stress effects on photosynthetic rate and leaf gas exchange characteristics. The experiment had been done to four wheat (Triticum aestivum L.) cultivars which were evaluated under semi-controlled conditions. According to Siddiques observation, four cultivars which were Kanchan, Sonalika, Kalyansona, and C306, grown in pots and were subjected to four levels of water stress. However, cultivars that showed the highest photosynthesis rates both at vegetative and at anthesis among others is the Kalyansona. They had concluded that the exposure of plants to drought stress led to noticeable decrease in photosynthesis rate, stomatal conductance and mesophyll conductance and a concomitant increase in intercellular CO2 concentration. The plants that were subjected to drought at the early vegetative stage displayed similar physiological characters subsequently under well-watered conditions as compared with control. Therefore, the photosynthesis rates decreased with decrease in stomatal conductance, but a weak relationship between them implied that non-stomatal limitations to photosynthesis might have been in operation. The involvement of CO2 concentration and assimilation was described in Farooq et al. (2008) report. The CO2  assimilation by the leaves is reduced mainly by the closure of the stomata, damaged the membrane and disturbed activity of various enzymes in the plants, especially those of O2  fixation and adenosine triphosphate(ATP) synthesis. Moreover, the enhancement of metabolite flux through the photorespiratory pathway had increased the oxidative load on the tissues as both processes generate reactive oxygen species. The damage and injury caused by reactive oxygen species to biological macromolecules under drought stress is among the major deterrents to growth.

Disruptions of Meanings in Kate Chopin’s “Desiree’s Baby”

Despite its brevity Kate Chopin’s â€Å"Desiree’s Baby† offers a rich account of the disruptions of meaning within literary texts. Such disruptions were achieved by Chopin through the use of Desiree Aubigny. The possibility of such is evident if one considers that Desiree Aubigny [as the main protagonist] enabled a more complex understanding of the meanings embedded within the concepts of race, sex, and class. In lieu of this, what follows is an analysis of Desiree Aubigny in Kate Chopin’s â€Å"Desiree’s Baby†. In this drama of misinterpretations, Desiree undermines certainty about the ability to read signs [e. . skin color] as clear evidence about how to categorize people. The disruption culminates when Desiree, whom everyone considers white, has a baby boy who looks partly black. When she is rejected by her husband, Armand, she takes the infant, disappears into the bayou, and does not return. Armand later finds out, however, that he himsel f is black, on his mother's side. This, though unintentional has devastated him by means of these two surprises, one concerning her supposed race and one concerning his own. In order to fully understand this, it is necessary to present an analysis of how the story unfolds. The story takes place in an antebellum Creole community ruled by institutions based on apparently clear dualities [master over slave, white over black, and man over woman]. Complacently deciphering the unruffled surface of this symbolic system, the characters feel confident that they know who belongs in which category and what signifies membership in each category. It is important to note that within the story the aforementioned dualities parallel each other as critiques of their hierarchical structures. Within this system of race, sex, and class, the most complacent representative is Armand Aubigny. Confident that he is a white, a male, and a master, he feels in control of the system. However, such confidence will later be challenged by his wife Desiree. In order to understand how his wife challenged the hierarchical representation of signification [and hence that of meaning], we must take a closer look at the surprises that Armand encounters. The tale begins with a flashback about Desiree’s childhood and courtship. She was a foundling adopted by childless Madame and Monsieur Valmonde. Like a queen and king in a fairy tale, they were delighted by her mysterious arrival and named her Desiree. It is important to note that Desiree means â€Å"the wished-for one† or â€Å"the desired one†. Desiree in this sense was depicted like a fairy-tale princess who â€Å"grew to be beautiful and gentle, affectionate and sincere,-the idol of Valmonde† (Chopin, 1995, p. 160). When she grew up, she was noticed by Armand, the dashing owner of a nearby plantation. He fell in love immediately and married her. She â€Å"loved him desperately. When he frowned she trembled, but loved him. When he smiled, she asked no greater blessing of God† (Chopin, 1995, p. 162). They were not to live happily ever after, however. Thus occurs the initial subversion of meaning resulting from the reversal of the accustomed â€Å"happy ending† that usually concludes such fairy tales. It is important to note that the short story initially started with the depiction of the figures [Desiree and Armand] in such a fashion as that of fairy tale figures despite of such an initial description and depiction of their situation, the ending [or rather the later parts of the story] shows that such an ending as that which is warranted by such stories which takes the aforementioned form [fairy tale stories] was to be subverted within the aforementioned tale. Soon after the story proper opens, Armand meets with the first surprise. He, other people, and finally Desiree see something unusual in her infant son's appearance. She asks her husband what it means, and he replies, â€Å"It means . . . that the child is not white; it means that you are not white† (Chopin, 1995, p. 163). Desiree writes Madame Valmonde a letter pleading that her adoptive mother deny Armand's accusation. The older woman cannot do so but asks Desiree to come home with her baby. When Armand tells his wife he wants her to go, she takes the child and disappears forever into the bayou. Thus, Armand's first surprise comes when he interprets his baby's appearance to mean that the child and its mother are not white. What seemed white now seems black. Desiree, with the child she has brought Armand, has apparently uncovered a weakness in her husband's ability to decipher the symbols around him. Ironically, Desiree's power comes from the fact that she seems malleable. Into an established, ostensibly secure system, she came as a child apparently without a past. As a wild card, to those around her the girl appeared blank, or appeared to possess nonthreatening traits such as submissiveness. Desiree seemed to invite projection [as Madame Valmonde’s desired child, Armand’s desired wife]. Both [Madame Valmonde and Armand], however, deceived themselves into believing they could safely project their desires onto Desiree, the undifferentiated blank slate. Actually, however, her blankness should be read as a warning about the fragility of representation. One aspect of Desiree’s blankness is her initial namelessness. As a foundling, she has lost her original last name and has received one that is hers only by adoption. Even foundlings usually receive a first name of their own, but in a sense, Desiree also lacks that, for her first name merely reflects others individuals’ desires. In addition, namelessness has a particularly female cast in this society, since women, including Desiree, lose their last name at marriage. Namelessness connotes not only femaleness but also blackness in antebellum society, where white masters can deprive black slaves of their names. Although Desiree’s namelessness literally results only from her status as a foundling and a married woman, her lack of a name could serve figuratively as a warning to Armand that she might be black. Concerning sex, race, and class, Desiree upsets systems of meaning but-by failing to connect the personal with the political-stops short of attacking hierarchical power structures. Disruption of meaning could lead to, and may be necessary for, political disruption, but Desiree does not take the political step. Instead of attacking the meaningfulness of racial difference as a criterion for human rights, Desiree takes a more limited step as she reveals that racial difference is more difficult to detect than is commonly supposed [e. g. through physical traits]. In this view, suffering can result if people classify each other too hastily or if, having finished the sorting process, people treat their inferiors cruelly. However, the system of racial difference, with its built-in hierarchy, persists. In this system, superiority is still meaningful; the only difficulty lies in detecting it. The importance of Chopin’s aforementioned story is thereby evident if one considers that it presents three reasons [unconsciousness, negativeness, and lack of solidarity] to help explain why Desiree does reveal her society's lack of knowledge but fails to change its ideological values, much less its actual power hierarchies. She poses so little threat to the dominant power structures that she holds a relatively privileged position for most of her life. Yet subversiveness need not be bound so tightly to traits such as unconsciousness that makes it self-limiting. Desiree’s existence as enabling the subversion of meaning must thereby be taken seriously if one is to consider that Chopin through the aforementioned character and her story enabled to show that explicit meanings although necessary are not sufficient means for understanding the underlying conditions implicit in existence. In a sense, Desiree serves as a reminder for individuals to continually consider what lies beneath the implicit assumptions that generates meanings [and hence stereotypes or modes of classification] within society.

Comparion of In Seach of Respect by Philippe Bourgous and...

In search of Respect by Philippe Bourgois and Shatteing Silence by Begona Aretxaga, are extremely great books which focus around similar themes. In this review both books will be separately analyzed and compared with one another. The content of shattering silence is pretty straight forward. The book contains issues on equality between genders and ethnicities as well. Shattering silence takes place in Ireland. Both In search of respect and shattering silence are set up with similar themes yet have different backgrounds, people and races. Begoà ±a Aretxaga reviews the problems and promise of feminist change in Northern Ireland with the start of the â€Å"Troubles† in the start of the 1969 civil rights movement. She views the kinship of power and†¦show more content†¦Aretxaga adds not only to anthropology and feminist studies but also to research on ethnic and social conflict by showing the gendered constitution of political violence. She goes further by asserting that violence affects men and women differently by arguing that the manners in which violence is gendered are not fixed but constantly shifting, depending on the likelihood of history, social class, and ethnic identity. In search of respect analyzes the social marginalization of Puerto Ricans living in East Harlem, New York City, USA. The friendship made with Philippe and the drug dealers were fundamental to the book’s nature; the very personal things that the subjects reveal to Bourgois make it extremely honest and give you a full picture for what exactly is happening and their reasoning behind their actions. Bourgois sets out his themes ,Gender inequalities, Kinship, through transcripts, backgrounds, life stories, and black and white images while explaining his own emotions and thoughts. His honesty and the transcripts especially, which include background noises such as gun shots are important to the books achievement as he leaves nothing out and lets you fully saturate yourse lf into the situations he is in. He says: â€Å"I refuse to ignore or minimize the social misery I witnessed, because that would make me complicitous with oppression† (p. 12)

Practice Speaking French Every Day

Daily French practice is a must since its only by practicing and using your French that youll be able to develop fluency, which occurs slowly over time. Aside from talking in French class and reading French books, there are a number of other ways you can incorporate French into your daily life. The basic premise is to use French whenever and wherever you can. Some of these ideas might sound silly, but the point is to demonstrate how you can easily introduce French into everyday situations. Thinking about French every day will help you learn how to think in French, which is a key element of fluency. You want your brain to go straight from seeing something to a French image, instead of going from object to English thought to French thought. Your brain will eventually process French faster, which facilitates fluency.   Fill your home and office with French Things Surround yourself with French things.  Make French labels for your furniture, appliances, and walls; buy or create French posters, and use a French calendar. French first Make French the first thing you see when you connect to the Internet. Set a high-quality French entity, such as  easy French news on Radio France Internationale, as your browsers default  homepage. Practice Your French If you know other people who speak French, practice with them whenever you can. Dont let speaking anxiety hold you back. For example, you and your roommate can declare Mondays and Fridays French day and communicate only in French all day. When you go out to a restaurant with your spouse, pretend youre in Paris and speak French to each other.   French Lists Need to make a shopping list or a to-do list? Do them in French. If the other people you live with speak French, write notes to them in French. Shopping in French When you go shopping, practice French with yourself.  For instance, count out your apples or your cans of tuna fish in French, look at prices and imagine how to say them in French. Routine French Think in French while performing routine actions. When walking to the refrigerator, think Jai soif or Quest-ce que je vais manger  ? Consider the conjugations of se brosser while brushing your teeth and hair. State the French name of each item of clothing as you put it on or take it off. Vocabulary Building Keep a notebook handy so that you can write down new words and keep track of ones you need to look up. This can also be part of a French journal or language scrapbook. French Internet If you use Windows, you can set your computer to display menus and dialogs in French. Mots flà ©chà ©s (Crosswords) Print out free mots flà ©chà ©s  and see how well you do. How Students Themselves Practice Speaking French Lets look at some of the great ideas students themselves have  for practicing spoken French. The following comments were taken from a French learning forum:   I challenge myself by picking a few objects around me and playing I spy with myself or others around me who also speak French. For example, I see an umbrella. Using circumlocution, I describe the item without using any of the words, such as pluie (rain), to give it away.  Because Im so self-conscious about speaking French, I find myself speaking it to my mother, who speaks no French. A live person allows me to put myself out there and I can practice my pronunciation without feeling so uncomfortable. Speaking to someone live forces me to form the word order in my mind along with the pronunciation. Ill say it out loud in her presence, then switch over to English so that she can understand me.I make sure to find things in French that really interest me so that it doesnt feel like school. The Internet is a great source because there are so many avenues to explore. I read reviews of things Im interested in, like books and movies. I go to French language message boards that deal with sub jects Im interested in. Ive also started a journal which is slow going but fun because I get to write about whatever Im interested in.I have books on tape in French and I listen to them while driving. I also have a teddy bear that a French friend gave me. When you press his jaws, paws or stomach he says things like Je mendors...Bonne nuit, or Aà ¯e  ! Ça fait mal; his left paw says Bonjour. Every morning, I touch his paw, he says Bonjour and I proceed to tell him, in French, my plans for the day. It gets me in the mood for French for the remainder of the day.  I try to skim the French newspaper Le Monde on the Web several times a week. If I have time, Ill read one of the articles out loud, which is difficult because the stories are written in fairly sophisticated written French, not in the style of a newscast. Occasionally, I play their aural stories. And I get daily and weekly horoscopes in French from Yahoo. They usually have a lot current French expressions in them.I lis ten to a series of Hachette pronunciation tapes, Phonà ©tique, in the background. I try to do the exercises, but they sometimes are very difficult even when I can give them my full attention, and its easy to get frustrated. If the International Film Channel or the Sundance Channel is showing a movie Ive already seen, Ill try to keep that on in the background to see if I can pick up the French.  I often try to think of the French equivalent of something and articulate it, but Im often worried about speaking in phony French and  making mistakes, which would be easy to do since I havent studied French in quite some time. Were these ideas promising? If any seemed useful, try them yourself. The more you practice, the more youll train your brain to think in French. And over time, that leads to fluency.  Bonne chance.