Comparing The Slavery Of Frederick Douglass And Harriot...

Giselle Cervantes Professor Baughn History 11 23 October 2017 Slave Narratives Slavery was something cruel and unhuman that many of our brothers and sisters endured. For many years colored men, woman, and children did not have much to live with. The description of the two different narratives of Frederick Douglass and Harriot Jacobs are quite distinct, yet so alike in through their experiences as slaves. A similarity between Douglass and Jacobs narratives was that they both described their childhood and horrible things they had to witness, which lead to the loss of innocence at a young age. At the beginning of Douglass he tells us that children are typically taken away from their mothers at a young age. They only saw each other at†¦show more content†¦Douglass was young when he found his identity through his escape from Baltimore to Massachusetts. Jacobs, on the other hand, became trapped in her community, family, and domesticity. She was â€Å"domestic† where she worked, as well as a slave with children. Jacobs expressed, Slavery is bad for men but it is far more terrible for women. Jacobs’s narrative was explicit and frightening for herself and for the woman of her time because of the involvement with her master’s forced sexual interactions. Jacobs’s narrative is the sexual exploitation that she and all other woman who were slaves at the time had to face and endure. In comparison to Douglass, Jacobs was determined to fight for her freedom. Although, Douglass showed his audience â€Å"how a slave became a man† by being in a physical fight with a superior, Jacobs’s gender demonstrated a different perspective. She was pregnant with the child of a white man when she was fifteen and believed that it would encourage her master to sell her and her child. Once she was became mother with â€Å"ties to life,† her concern for her children had taken over her own self-interest. Throughout Jacobs narrative, she is not only looking for freedom but a home to prot ect her children. The impact of gender roles on their attempt to gain freedom was similar. Jacobs spent a lot of her time as a slave fighting for freedom by being â€Å"domestic† and protecting her children because

Isolated Chloroplasts Bad Example Free Essays

Light Reactions in Isolated Chloroplasts Racquel Currie University of Minnesota Minneapolis, Minnesota Hypothesis If isolated chloroplasts are boiled, the enzymes that occur in photosynthesis are disrupted and the DCIP will not reduce. Chloroplasts are a type of plastid found within the plant they are the basis of photosynthesis. Without photosynthesis there would be no life on earth. We will write a custom essay sample on Isolated Chloroplasts Bad Example or any similar topic only for you Order Now Photosynthesis takes the energy from sunlight and coverts it into a chemical energy that can be used by the plant. Isolating chloroplast is a way to separate plastids in order to study the details of the single cell. Isolating the chloroplast helps better understand the functions and helps determine if the isolated chloroplasts are adequate to complete photosynthesis. Biological activity will be determined by using a dye, dichlorophenolindophenol (DCIP), as a final electron acceptor. Using spectrophotometry, the reduction of DCIP will be measured to follow the dye from an oxidized (DCIP) to a reduced state (DCIPH2) as it accepts electrons from photosystem I (1). Boiling affects the Materials and Methods In order to isolate the chloroplasts, the process had to have been completed rapidly in subdued light. When the solutions were not being used they were stored on ice. Ten spinach leaves were rinsed and deveined. They were then placed over ice and chopped with a razor. After, the spinach was placed between eight layers of cheesecloth to squeeze all the liquid derived from the spinach. The liquid was then diluted by adding 20mL of homogenizing buffer (HB). The solution was added to a pre-cooled conical centrifuge tube, and was then centrifuged at 1000 x g for one minute. After, the solution was transferred to another pre-cooled centrifuge tube and was centrifuged at 3000 x g for one minute. Centrifugation resulted in the deposition of a green pellet on the wall of the centrifuge tube near the surface of the liquid (2). This green pellet, together with the green liquid, was separated from the more dense material that had been deposited at the bottom of the tube (2). The supernatant was decanted, and the pellet was re-suspended in 10 mL of HB. The final centrifuged process occurred at 3000 x g for one minute. After the final centrifuge the supernatant was poured off and discarded. The isolated chloroplasts were re-suspended and mixed with 10ML of suspension solution (SS). After this process to isolate the chloroplast it was stored on ice and was stable for two to four hours. After the isolation of chloroplasts the question was asked if boiled chloroplast would reduce DCIP reaction mixture, and would this affect the activity of electrons from photosystem 1. 0. 1 mL of chloroplast was measured with a pipette into a tube and then suspended in boiling water for one minute. A spectrometer was used and set to 0 (set at 600nm). There was also a control used, which was chloroplast that went through the same methods as above, although it did not get boiled (heated). The control was measured by the spectrometer and the treated (boiled) sample was measured immediately after the boiling process. The control and treatment was then exposed to bright light for 15 second intervals. After each interval the color density was measured by the spectrometer. This process continued until there was no change in the color density. Results Figure 1 Figure 2 Discussion DCIP was used as a marker to indicate if the photosynthesis was still taking place in the isolated chloroplasts after boiling. The DCIP replaced the NAPD enzyme. The hypothesis, if isolated chloroplasts are boiled, the enzymes that occur in photosynthesis are disrupted and the DCIP will not reduce was shown to be true based on the results of figure one and two. Where as the control’s color density did decrease with the exposed light intervals. Literature Cited 1. K. Sami Nichols Light reactions in isolated chloroplasts Lab 2. C. RALPH STOCKING. Chloroplast Isolation in non-aqueous media. Plant Physiology 56-60. http://www. ncbi. nlm. nih. gov/pmc/articles/PMC541142/pdf/plntphys00351-0065. pdf 3. Paul Armond Heat-induced changes of chlorophyll fluorescence in isolated chloroplasts and related heat-damage at the pigment level. Carnegie Institution of Washington http://www. sciencedirect. com/science/article/pii/000527287890138X 4. Eric Tuan The Effect of Light Conditions and Boiling on the Rate of Photosynthesis by Isolated Chloroplasts http://www. grochbiology. org/aplabwriteupexample. htm How to cite Isolated Chloroplasts Bad Example, Papers

Relationship between Flock Size & Vigilance Time-Free-Samples

Question: Discuss about the Relationship between flock size and vigilance time. Answer: Introduction: The living organisms surviving in groups has many advantages, one of them is that when in groups they need to spend less time in vigilance and thus can allocate percent of time in foraging and other essential behaviours (Beauchamp 2015). Evidential studies have reported that in many foraging birds and mammals, there exists negative correlation in between the size of the group and vigilance known as group size effect. The effect of detection or the many eye hypotheses explains this inversely proportional relationship (Li et al. 2012). According to the many eyes hypothesis, the increased number of eyes can detect a predator more easily and hence the individuals reduces their self vigilance and gains from the members of the other group as because the predator have the tendency to predate one prey at a time during their time of attack (Beauchamp 2013). This shows that the time for conducting other activities increases when in a group of larger size. Thus the foraging efficiency increases with time (Golabek, Ridley and Radford 2012). The many eyes hypothesis relates that vigilance plays an important role in detection of predators and thus is known as predation effect. Hypothetical view: It has been seen that several birds in flocks benefits through foraging. The flocking tendency helps them to avoid predator either by dilution effect or by confusion them explained through many-eyes hypothesis (Zoratto et al. 2014). It has been made evident in some of the cases that even the vigilance of the individual declines, the whole vigilance of the flock increases. This type of relationship observed in the vigilance level and size of the group is considered as an advantage while surviving in flocks (Olson et al. 2015). This observation based idea is sometimes correlated with the selfish herd hypothesis. According to this hypothesis, the animals and the birds present on edges try to secure position in the middle of the flock (Pincock 2012). This hypothesis was observed in the macropid marsupial and in mixed sparrow flocks, in which the spatial distance affected the vigilance between the members of the flocks. Vigilance: Behavioural studies on columbid wild laughing dove had shown that groups with larger size had more chance in detecting any possible threat approaching towards them as compared with the groups with smaller size (Forshaw 2015). Based on this study, it was found that the information must be transmitted quickly within the members of the flocks in order to make the group size effective. As the foraging decreases the individual efficiency in vigilance as seen in birds, the size of the group is thought to influence the benefits and the individual costs (Marshall et al. 2012). Hence, the foraging by flock can decline the risk of predation during enhancing the intake of food. Some studies alternately show no such reduction in the individual vigilance with the increase in the size of the group. Vigilance is considered as the primary function in the protection of anti-predation (Fichtel 2012). Other factors that influence the rate of vigilance are various competitions such as interference compe tition and scramble, covering distance in concern, the age, gender, dominating status and observer proximity. Vigilance is said to be positioned towards predator and conspecifics eventually (Jayne 2014). Hence, the other components of behaviour and spatial factors of flocks are investigated that will suggest new vigilance effect. Studies on varied vigilance based on spatial positioning in flock showed that individuals present in the peripheral region spends more percent of time in comparison to the individuals present in the central position in vigilance (Darrah 2013). This type of effect is known as the edge effect and explains that the individuals present in the periphery have higher risk to get exposed to predation and acts as defender in providing prevention to the central placed individuals. In this study we will investigate how the size of flocks affect the foraging behaviour in an individual with varying size of the flocks and in which the vigilance also varies with the flock size. Thus in order to study whether the rate of foraging increases in flocks with larger size, we need to examine the relationship effect between the flock size and vigilance behaviour. We took the Australian Wood Ducks as the model system to determine the flock size effecting both time required in foraging and also competition level. We examined that whether increase in the group size positively affected in decreasing the risk of predation and hence helps in gaining more time in foraging or the increase in competition decreases the predation risk. The species mentioned in this discussion are the Australian Wood Duck, Chenonetta jubata, a grazer by nature spending more than 30% of whole day in grazing with frequent bouts (Ndlovu Hockey and Cumming 2017.). These birds are distributed in Australia, involving Tasmania too. The habitat of Australian Wood Duck is open woodlands with grasslands, pastures usually flooded and the bay coast. They inhabit the dams with farmland with sewage ponds and urban parks. These birds prefer foraging on lands. These birds are usually found in flocks ranging in between 100 to 2000 individuals in flock (Murray et al. 2013). The feeding habit includes grasses, herbs, grains and sometimes insects. These are found to forage in shallow water or grasslands. we will analyse that the vigilance by an individual decreases depending on the size of the group by predicting that increased in group size would increase the time required for foraging purpose with increased competition. Finally, we enhanced the fact that, the overall rate of intakes would increase with increased time for foraging till there is no such negative impact of competition interference on successful foraging. The size of the flock is found to be related with seasonal factors, disperse while breeding and congregates after breeding (Camacho 2012). All the above stated factors will be analysed by taking the Australian Wood Duck as the model system. Methodologies: The site under study: The study was performed in a shallow grassland taking Australian Wood Ducks as the model for studying the vigilance effect with respect to time. The vegetation of the area is mostly composed of grasses and some trees. In the dry season, from July to August, the observations and recording data corresponding the foraging activities was done in the morning time. The estimation of the population density was done by noting the individual count per flock that encountered in various regions in the study area. The flocks when discovered, the individuals were chosen randomly from the centre and the edge of flock when the size of the flock exceeded two. The individuals were positioned in the middle of there was one bird in between the individual in focus and the flock edge. But if no individuals were found in between the flock edge and the one in focal region, the individual was positioned in the edge. The recordings were made by the use of 10x25 binoculars with 5 minutes time interval with th e help of the focal-animal sampling methodology (Schlacher Nielsen and Weston 2013). The data collected were related to size of the group, scanning rate and the total duration in vigilance. The varying distances between the individuals, shifting the position and behavioural duration such as interactions, resting and foraging were also recorded. The behavioural scanning was recorded whenever an individual from the flock raised head from a horizontally marked line of the body. The individual distance was marked according a relative position of a tree which was noted as the marker. Observations: The size of the group was recorded at the beginning of the study and if the group size got altered due to any kind of dispersal, that observation session was ended, with the start of a new session. The foraging activity of the individuals was, walking with head-down and searching, thereby probing and substrate handling that covered most of the time in observing. This time was obtained by subtracting the time taken in doing other tasks from the time recorded in total observation. Findings: In the area under study, six animals/ha with 150 flocks of wood duck was recorded. The sample of the flocks varied from individual foragers to the wood duck groups comprising up to 20 individuals. The rate of scanning and the time taken in vigilance were noted respectively. The results were negatively correlated between the rate of scanning and the size of the flock. Sane correlation was found between the vigilance of the individual and the size of the flock. The time for foraging showed a mean value of 28030 (N=150) which corresponded to the size of the flock. The geometry of the flock and the average distance in cm were also recorded. It was found that only 28% of the individuals shifted among the flocks whereas 68% of the individuals shifted to the corner from the edge and 32% shifted to the edge from the centre position. The time of scanning, the time expenditure in vigilating and time of foraging was significantly related in between the individuals in the peripheral and in the c entre. More than 93% of observed time was due to foraging. Low aggression rate should no effect in between the group size and aggressive behaviour. It was found that as the group size increased, the aggression also increased. Discussion: Based on other relevant research studies, it was found in this study that the vigilance in individual reduced with the increased in size of the flock in Australian Wood Duck (Fernndez-Juricic 2012). The incorporation of the left out time in the activities concerning the foraging was noted due to the reduced time in individual vigilance. The reduced distance recorded among the members of the flock can be linked with conspecifics vigilance. This action can improve the responding towards predators which is possible due to fast mode of information transmission among the flockmates. The vigilance of this type can be demonstrated by peripheral vision, as the birds with head-down are capable of detecting threats though in lower rates as compared to vigilant birds (Edwards et al. 2013). The distance can be another factor between the members of the flocks that affects the rate of vigilance. In relating the risk of predation, the position of the flock plays an important role and has direct effect in the rate of vigilance. The amount of time spends by the individuals in vigilance purpose and foraging was related to their position among the flock. The individuals of Wood Duck birds at the edges functioned as more vigilant than the individuals in the middle (Beauchamp 2015). It was found that the individuals in the middle of the flock took more time during foraging as compared to the individuals in the edge of flock. Various studies revealed that the individuals preferred the central position as explained in the selfish herd hypothesis (Pincock 2012). This tendency can be due to the feeling of being protective in the middle of the flock by the individuals present in the peripheral region of the flock. This helps the centred individuals with the benefit of spending less amount of time in vigilance and gaining more time in foraging purpose. It can predict that due to a pre-es tablished hierarchy in grouping, the frequency by which the positional shifting occurs is lowered. Taking this prediction into consideration, it can be said that social organizing occurs by gaining benefit being in the central position of flock and hence are occupied by the dominating individuals. Due to this differences in the behaviour can be expected in allocating the time during vigilance and other activities such as foraging. The results have suggested that though there are low aggression rates, still there lies a relation between the size of the flock and the aggressive behaviour. This relationship indicates the interference effect that influences the rate of vigilance. Hence, it can be said that the individuals need to direct the vigilance towards the potential predators and also to the other members of the flock (Beauchamp 2015). However, more data are required to understand the effect of the size of group as the aggression was observed in rare case. Thus, it can concluded that the size of the group significantly affect the vigilance and the main force for driving the effect of the group size and trade-off found in the case between the foraging and vigilance is the pressure created due to predation. Scramble competition is also found to play a crucial role in effecting the size of the groups (Clutton?Brock and Janson 2012). The increased scramble intensity with decreased vigilance is found to be related with increase in group size References: Beauchamp, G., 2013.Social predation: how group living benefits predators and prey. Elsevier. Camacho, C., 2012. Variations in flocking behaviour from core to peripheral regions of a bird species distribution range.Acta ethologica,15(1), pp.153-158. Clutton?Brock, T. and Janson, C., 2012. Primate socioecology at the crossroads: past, present, and future.Evolutionary Anthropology: Issues, News, and Reviews,21(4), pp.136-150. Darrah, A., 2013.Ecology and flock-following behavior of the wedge-billed woodcreeper in Eastern Ecuador. University of Arkansas. Edwards, A.M., Best, E.C., Blomberg, S.P. and Goldizen, A.W., 2013. Individual traits influence vigilance in wild female eastern grey kangaroos.Australian Journal of Zoology,61(4), pp.332-341. Fernndez-Juricic, E., 2012. Sensory basis of vigilance behavior in birds: synthesis and future prospects.Behavioural processes,89(2), pp.143-152. Fichtel, C., 2012. Predation.The evolution of primate societies. University of Chicago Press, Chicago, pp.169-194. Forshaw, J., 2015.Pigeons and doves in Australia. CSIRO PUBLISHING. Golabek, K.A., Ridley, A.R. and Radford, A.N., 2012. Food availability affects strength of seasonal territorial behaviour in a cooperatively breeding bird.Animal Behaviour,83(3), pp.613-619. Jayne, K., 2014. Challenges faced by foraging Eastern grey squirrels, Sciurus carolinensis: competition, pilferage and predation risks. Li, C., Jiang, Z., Li, L., Li, Z., Fang, H., Li, C. and Beauchamp, G., 2012. Effects of reproductive status, social rank, sex and group size on vigilance patterns in Przewalski's gazelle.Plos one,7(2), p.e32607. Marshall, H.H., Carter, A.J., Rowcliffe, J.M. and Cowlishaw, G., 2012. Linking social foraging behaviour with individual time budgets and emergent group-level phenomena.Animal Behaviour,84(6), pp.1295-1305. Mdahlem.net. (2017).Cite a Website - Cite This For Me. [online] Available at: https://www.mdahlem.net/img/ozbirds/2/wooduck_2033_big.jpg [Accessed 22 Aug. 2017]. Murray, C.G., Kasel, S., Loyn, R.H., Hepworth, G. and Hamilton, A.J., 2013. Waterbird use of artificial wetlands in an Australian urban landscape.Hydrobiologia,716(1), pp.131-146. Ndlovu, M., Hockey, P.A. and Cumming, G.S., 2017. Geographic variation in factors that influence timing of moult and breeding in waterfowl.Zoology. Olson, R.S., Haley, P.B., Dyer, F.C. and Adami, C., 2015. Exploring the evolution of a trade-off between vigilance and foraging in group-living organisms.Royal Society open science,2(9), p.150135. Pincock, C., 2012. Mathematical models of biological patterns: Lessons from Hamiltons selfish herd.Biology Philosophy,27(4), pp.481-496. Schlacher, T.A., Nielsen, T. and Weston, M.A., 2013. Human recreation alters behaviour profiles of non-breeding birds on open-coast sandy shores.Estuarine, Coastal and Shelf Science,118, pp.31-42. Zoratto, F., Manzari, L., Oddi, L., Pinxten, R., Eens, M., Santucci, D., Alleva, E. and Carere, C., 2014. Behavioural response of European starlings exposed to video playback of conspecific flocks: effect of social context and predator threat.Behavioural processes,103, pp.269-277.