The effect of blood donation frequency and gender on ...



The effect of blood donation frequency and gender on physiological response to blood loss

Stephanie Melton and Jessica Ochoa

Department of Biological Science

Saddleback College

Mission Viejo, CA 92692

The human body has several physiological compensation mechanisms for blood loss.  A change in blood pressure is one such mechanism.  A blood donor loses approximately ten percent of total blood volume when donating blood.  Ten percent is a blood volume significant enough to stimulate compensation mechanisms. This study was conducted to test the hypothesis that there is a significant difference between the pre- and post-donation blood pressures in first-time donors, compared to frequent donors.  The objective of the study was to evaluate if donors physiologically adapt to blood loss if blood loss occurred frequently.  The study took pre- and post-blood donation blood pressures from thirty frequent donors and thirty first-time donors.  Our results indicate that there is not a significant difference in the change in systolic and diastolic blood pressures pre- and post- donation in frequent donors compared to first-time donors. (unpaired t-test, two-tailed, p>0.05) These results suggest that frequent donors do not adapt to blood loss. Also within this study frequent male donors were compared to frequent female donors and first time male donors were compared to first time female donors. The study found that there was no significant difference in the body’s physiological response that correlates to gender.

Introduction

The human body contains, on average, five pints of blood (Velasquez, 1987).  Blood is an essential bodily fluid that is comprised of hematocrit, or red blood cells, and plasma.  The red blood cells contain the hemoglobin protein that carries oxygen to organs and muscles and aids in the removal of carbon dioxide. Each hemoglobin contains a heme groups, to which iron binds.  This iron is the binding site for oxygen (Franchini, 2008).  The circulation of blood throughout the body is maintained by heart rate, cardiac output, and blood pressure.  Cardiac output and blood pressure are monitored by baroreceptors in the aortic arch and carotid arteries.  Baroreceptors detect the amount and the pressure of blood passing through the aorta and carotid arteries during each heart beat (Mancia, 1986). Baroreceptors are also responsible for moderating heart rate in response to changes in blood pressure (Parati, 218).

Whole blood donation involves the removal of 500 mL of blood (hematocrit and plasma) from the donor.  This volume corresponds to a reduction of approximately 10 percent of total blood volume (Velasquez, 1987).  With the loss of hematocrit, approximately 225-250 mg of heme is removed (Salonen, 446).  Consequently, the concentration of oxygen in the body is reduced (Meyers, 1997).  The loss of oxygen, if severe enough, will decrease tissue perfusion, which will eventually lead to cellular hypoxia, organ damage, and death (Peng, 2005).

 When a subject loses blood (hemorrhage), the body initiates several neurohumoral compensation feedback mechanisms.  Some mechanisms are immediate; others are slow-acting, long-term mechanisms (Haberthur, 2003).  The volume of blood lost directly corresponds to the severity of the compensation. During a minor amount of blood loss, physiological compensation is not noticeable.  However, when blood loss is around 10 percent, such as with blood donation, several compensatory mechanisms occur in the body. 

The immediate mechanisms are initiated by the baroreceptors. When the baroreceptors in the aortic arch and carotid arteries detect a reduced blood volume, signals are sent from the sympathetic nervous system causing heart rate to increase, arteriole beds in muscle and skin to constrict, and veins to constrict (McGuill, 1989).  The combination of these three responses is effective in the maintenance of arterial pressure, venous return to the heart, and cardiac output (McGuill, 1989). This ensures organs and tissues remain adequately perfused.  With a blood loss volume greater than 10 percent, a subject would suffer significant decrease in blood pressure and cardiac output, as well as tachycardia, and further arteriolar constriction (McGuill, 1989).

The long term mechanisms function to replace the lost blood volume.  These responses include the secretion of antidiruetic hormone and the activation of renin-angiotensin aldosterone hormone system (McGuill, 1989).  These hormones function in the kidneys to reduce the amount of fluid lost in urine through the re-absorption of fluids.  This re-absorption of fluid increases blood pressure by increasing the volume of fluid in the body (McGuill, 1989). 

Another long-term response is the release of erythropoietin by the kidneys to stimulate the production of new red blood cells (Salonen, 1998).  Approximately eight weeks recovery time is required between blood donations.  This recovery time allows the blood volume that was removed to be replenished by the production of new red blood cells.

Several studies have been conducted to evaluate the effect of acute blood loss on blood pressure and mean arterial pressure (MAP). (What exactly is MAP?)One study found that acute loss of blood resulted in a slight decrease in systolic blood pressure and no change in diastolic blood pressure post blood donation in hypertensive subjects (Velasquez, 1987).  A separate study found that hemorrhage resulted in a sympathetic nervous system response (i.e., increase heart rate and blood pressure) (Haberthur, 2003).

This study was conducted to evaluate the effects of blood loss on systolic and diastolic blood pressure, heart rate, and mean arterial pressure. Whole blood donors were the participants.  The purpose of the study was to determine if people physiologically adapt to blood loss if the body is subjected to the stress of hemorrhage frequently. Such adaptations would include a lessened increase in heart rate, less arteriolar and venous constriction, and a lessened increase in blood pressure. This study focused on changes in pre- and post-donation systolic and diastolic blood pressures, heart rate, and MAP.  The hypothesis being tested is that there is a significant difference between the pre- and post-donation blood pressures, heart rate, and MAP in first-time donors compared to frequent donors.   

Materials and Methods

The study subjects consisted of blood donors at various American Red Cross donation centers throughout Orange County, California.  The subjects were divided into two groups depending on the frequency of blood donation.  Frequent donors were classified as donors who donate blood three or more times a year.  First-time donors were donors who had not previously donated blood.  The subjects were further divided into two based on sex, male and female.  The two data groups consisted of frequent donors and first-time donors.  Other variables affecting heart health were not taken into consideration.  Since the only factor being evaluated is the change in blood pressure, heart rate, and mean arterial pressure due to blood loss, any extraneous health conditions were not considered to significantly influence the data.  The data groups consisted of 30 first time donors and 30 frequent donors.  Of these, half were male and half were female.  Overall the prediction was there would be a reduced change in the pre- and post-donation for frequent donors compared to first-time donors.  Specifically, it was predicted that frequent donors would have a smaller decrease in blood pressure than first time donors.  The change in heart rate was predicted to smaller in frequent donors than first time donors.  The drop expected in mean arterial pressure was predicted to be less in frequent donors than first time donors. 

Data were collected from October 15, 2009 to November 6, 2009.  Each donor was asked the frequency of blood donation to categorize the subject in the correct data group.  The sex of the donor was also recorded.  Using a sphygmomanometer and stethoscope, the subject’s blood pressures were taken auscultatively before and after donating blood.  Heart rate was palpated at the wrist before and after donation as well.  Mean arterial pressure was calculated from the blood pressures using the equation: MAP=[(2D)+S]/3, where D equals diastolic blood pressure and S equals systolic blood pressure.

[pic]

Where D equals diastolic blood pressure and S equals systolic blood pressure. (You could probably leave it as you had it, but I think this looks a bit sharper)

The collected data were statistically analyzed using Excel software (Microsoft Corporation, Redmond, Washington) to determine if there was a significant difference in pre- and post- donation systolic and diastolic blood pressures, heart rate, and mean arterial pressures between the first time donors and frequent donors and between males and females.  The first statistical test, a paired F-test with variances, was used to determine if there were unequal variances between the data groups.  The F-test was followed with a two-tailed, unpaired T-test.  The T-test was used to determine if a significant difference exists between the pre- and post-donation systolic and diastolic blood pressures, heart rate, and mean arterial pressure of frequent and first-time blood donors.  T-tests will also be performed to determine if there is a significant difference between males and females for all data collected. (Delete space between p and parenthesis) ( p0.05) (Figure 2). (Consistency – In your figures your results are to the hundredth place; while in the results portion they are to the tens place.)

Your Y-axis label is also difficult to read

[pic] 

 Figure 1. Mean change in systolic blood pressure versus frequency of donation.  The mean change in systolic blood pressure for frequent donors was a drop of 1.73±1.3 mmHG (±SEM), N=11.  The mean change in systolic blood pressure for first-time donors was a drop of 2.27±1.7 mmHG (±SEM), N=11.  Mean change in systolic blood pressure was not significantly different between frequent and first-time donors (p>0.05, two-tailed, unpaired t-test). 

[pic]

 

Figure 2. Mean change in diastolic blood pressure versus frequency of donation.  The mean change in blood pressure for frequent donors was a drop of 0.82 ±1.4 mmHG (±SEM), N=11.  The mean change in blood pressure for first-time donors was a drop of 3.32±2.2 (±SEM), N=11.  Mean change in systolic blood pressure was not significantly different for frequent donors and first-time donors (p>0.05, two-tailed, unpaired t-test). 

The results of the two-tailed, unpaired T-test for pre- and post-donation heart rate between frequent and first time donors indicated that there was not a significant difference, (T-test assuming unequal variances, t=-0.41, df=40, and p>0.05) (Figure 3). 

[pic]

Figure 3. Mean change in heart rate versus frequency of donation.  The mean change in heart rate for frequent donors was an increase of 2.18±2.3 BPM (±SEM), N=11.  The mean change in heart rate for first-time donors was an increase of 3.36±1.8 BMP (±SEM), N=11.  Mean change in heart rate was not significantly different for frequent donors and first-time donors (p>0.05, two-tailed, unpaired t-test). 

   [pic]

The results of the two-tailed, unpaired T-test for pre- and post-donation MAP between frequent and first time donors indicated that there was not a significant difference, (T-test assuming unequal variances, t=-0.89, df=38, and p>0.05) (Figure 4). 

 

 

 

 

 

 [pic]

Figure 4. Mean change in mean arterial pressure versus frequency of donation.  The mean change in MAP for frequent donors was a decrease of 1.18±1.2 mmHG (±SEM), N=11.  The mean change in MAP for first-time donors was a decrease of 2.97±1.6 mmHG (±SEM), N=11.  Mean change in heart rate was not significantly different for frequent donors and first-time donors (p>0.05, two-tailed, unpaired t-test). 

The second set of statistical tests ran were comparing systolic and diastolic blood pressure, heart rate, and MAP for male and females.  For frequent male and female donors, there was no significant difference in the systolic (T-test assuming unequal variances, t=0.61, df=17, and p>0.05) (Figure 5) or diastolic blood pressures (T-test assuming unequal variances, t=-0.19, df=17, and p>0.05) (Figure 6). For first time male and female donors, there was also no significant difference in the systolic (T-test assuming unequal variances, t=-0.16, df=20, and p>0.05) (Figure 7) or diastolic blood pressures (T-test assuming unequal variances, t=-0.92, df=18, and p>0.05) (Figure 8). 

 [pic]

[pic]Figure 5. Mean change in systolic blood pressure versus gender for frequent donors.  The mean change in systolic blood pressure for frequent male donors was a decrease of 1.09±1.4 mmHG (±SEM), N=11.  The mean change in systolic blood pressure for frequent female donors was a decrease of 2.73±2.3 mmHG (±SEM), N=11.  Mean change in systolic blood pressure was not significantly different for frequent donors and first-time donors (p>0.05, two-tailed, unpaired t-test). 

 

 

 

 

 

 [pic]

 Figure 6. Mean change in systolic blood pressure versus gender for first time donors.  The mean change in systolic blood pressure for frequent male donors was a decrease of 2.55±2.5mmHG (±SEM), N=11.  The mean change in systolic blood pressure for first time female donors was a decrease of 2.00±2.4mmHG (±SEM), N=11.  Mean change in systolic blood presssure was not significantly different for frequent donors and first-time donors (p>0.05, two-tailed, unpaired t-test). 

  

 The results of the two-tailed, unpaired T-test for pre- and post-donation diastolic blood pressure between frequent male and female donors indicated that there was not a significant difference, (T-test assuming unequal variances, t=-0.19, df=17, and p>0.05) (Figure 7).    The results for first time male and female donors also indicated there was not a significant difference (T-test assuming unequal variance, t=-092, df=18, and p>0.05) (Figure 8).

[pic]

Figure 7. Mean change in diastolic blood pressure versus gender for frequent donors.  The mean change in diastolic blood pressure for frequent male donors was a decrease of 1.09±2.5mmHG (±SEM), N=11.  The mean change in diastolic blood pressure for frequent female donors was a decrease of 0.55±1.5mmHG (±SEM), N=11.  Mean change in systolic blood pressure was not significantly different for frequent donors and first-time donors (p>0.05, two-tailed, unpaired t-test).

[pic]

[pic]Figure 8. Mean change in diastolic blood pressure versus gender for first time donors.  The mean change in diastolic blood pressure for frequent male donors was a decrease of 5.27±3.4mmHG (±SEM), N=11.  The mean change in diastolic blood pressure for frequent female donors was a decrease of 01.36±2.5mmHG (±SEM), N=11.  Mean change in systolic blood pressure was not significantly different for frequent donors and first-time donors (p>0.05, two-tailed, unpaired t-test). 

Heart rate also showed no significant difference between frequent male donors and frequent female donors and between first time male donors and first time female donors. The results of the t-test for pre- and post-donation heart rate in frequent male and female donors indicated there was no significant difference (T-test assuming unequal variances, t=-1.31, df=15, and p>0.05) (Figure 9) nor in first time donors (T-test assuming equal variances, t=-1.07, df=17, and p>0.05) (Figure 10). 

[pic]

Figure 9. Mean change in heart rate versus gender for frequent donors.  The mean change in heart rate for frequent male donors was a decrease of 0.18±4.0mmHG (±SEM), N=11.  The mean change in heart rate for frequent female donors was an increase of 4.91±2.1mmHG (±SEM), N=11.  Mean change in heart rate was not significantly different for frequent male donors and frequent female donors (p>0.05, two-tailed, unpaired t-test). 

 

 

 

 

 

 

 

[pic]

Figure 10. Mean change in heart rate versus gender for first time donors.  The mean change in heart rate for first time male donors was an increase of 1.45±1.9mmHG (±SEM), N=11.  The mean change in heart rate for first time female donors was an increase of 5.27±3.0mmHG (±SEM), N=11.  Mean change in heart rate was not significantly different for first time male donors and first time female donors (p>0.05, two-tailed, unpaired t-test). 

Mean arterial pressure also showed no significant difference between frequent male donors and frequent female donors, nor between first time male donors and first time female donors.  The results of the t-test for pre- and post-donation MAP in frequent male and female donors indicated there was no significant difference (T-test assuming unequal variances, t=0.09, df=18, and p>0.05) (Figure 11). In first time donors, the t-test indicated there was no significant difference (T-test assuming unequal variances, t=-0.83, df=18, and p>0.05) (Figure 12). 

[pic]  

 [pic]

Figure 11. Mean change in MAP versus gender for frequent donors.  The mean change in MAP for frequent male donors was a decrease of 1.06±1.9mmHG (±SEM), N=11.  The mean change in heart rate for frequent female donors was a decrease of 1.28±2.7mmHG (±SEM), N=11.  Mean change in heart rate was not significantly different for frequent male donors and frequent female donors (p>0.05, two-tailed, unpaired t-test).

[pic] 

 

 

 

 

 

 

 [pic]

Figure 12. Mean change in MAP versus gender for first time donors.  The mean change in MAP for first time male donors was a decrease of 4.35±2.7mmHG (±SEM), N=11.  The mean change in heart rate for first time female donors was a decrease of 1.58±1.9mmHG (±SEM), N=11.  Mean change in MAP was not significantly different for frequent male donors and frequent female donors (p>0.05, two-tailed, unpaired t-test). 

Discussion

Our results indicate that there is not a significant difference between the pre- and post-donation systolic and diastolic blood pressures, heart rate, or MAP for frequent donors and first-time donors.  Additionally, there is not a significant difference between pre- and post-donation systolic and diastolic blood pressures, heart rate, or MAP for males and females.  These findings indicates that no matter how often a person experiences blood loss and the despite different genders, the body does not physiologically adapt to respond to the effects of blood loss faster.  Based on this result, the hypothesis and prediction of this study are not supported.

As previously discussed, the loss of blood during donation is enough to cause physiologic responses in a body. One such response is a lower blood pressure (McGuill, 1989).  Another physiological response is the activation of the baroreceptor response to changes in blood pressure.  With a decrease in blood pressure, the baroreceptors would send a signal to cause the heart to beat faster (Parati, 218).  If adaptation were occurring as a result of frequent blood loss, then the baroreceptors would reset to compensate for the changes in blood pressure.  With the frequent lowering of blood pressure, the baroreceptors would reset the response threshold to the lower blood pressure.  However, a previous study found that baroreceptor reflex sensitivity does not change as blood pressure values change (Parati, 219). In fact, baroreceptor mechanisms may only account up to 25% of the overall changes in blood pressure (Mancia, 152). Therefore, blood pressure changes are much more susceptible to physical activity and emotions.

As previously discussed, heart rate increases due to the baroreceptor response. Our results indicate that there was no significant difference for frequent donors and first time donors. If adaptation occurred, then the heart rate for frequent donors would be lower than the heart rate for first time donors since it would take first time donors a longer time to recuperate.

Mean arterial pressure (MAP) which is calculated from systolic pressure and diastolic pressure showed no significant difference between frequent donors and first time donors. MAP is the mean blood pressure over one heartbeat (This description of MAP is left out of the intro, maybe you should add it). Since there was no significant difference between systolic and diastolic pressures pre and post donation for frequent and first time donors it follows that there would be no significant difference in the blood pressure of one heat beat. The physiological responses in first time donors and frequent donors are not significantly different.

If the body were adapting to a reduced blood volume, the physiological response would have been a smaller change in systolic and diastolic blood pressure in the subjects who donated more frequently.  However, this finding was not the result of the present study.  Therefore, this study is suggestive that people do not adapt physiologically to blood loss regardless of frequency of occurrence.

Another form of adaptation is evolutionary adaptation.  Evolutionary adaptation (i.e., natural selection) is the genetic success of traits that allows a species to be better adapted to the environment.  Blood donation is a voluntary activity and therefore, is not an environmental stress to which a species must adapt in order to survive.  Since natural selection is the mechanism of adaptation for a species and blood donation is not an environmental stress, it follows that humans are not inclined to adapt to blood loss.

The findings of this study also indicate that both frequent and first-time donors should be monitored after donating blood.  The loss of blood can cause a donor to feel light headed or to have a syncopal episode.  Since both frequent and first-time donors sustain changes in blood pressure, both types of donors should be kept and monitored for a period of time after donation, to ensure there will not be an adverse reaction.

Further investigation should be conducted to verify these results.  Additional studies should consist of a larger sample size.  Alternative studies could include a comparison of the blood pressure recovery times to pre-donation levels for frequent versus first-time donors.  Although the instantaneous change in blood pressure is larger for frequent donors, a difference in the time for post donation blood pressure of frequent and first-time donors to return to the pre-donation blood pressure could be an indicator of adaptation.  Additionally, as mentioned in the introduction, several physiological effects result from blood loss.  This study determined that there is not a significant difference in pre- and post-donation blood pressures for frequent and first-time donors.  However, further investigation is required to determine if adaptation is occurring with regard to the other blood loss compensatory responses, such as heart rate, arteriolar constriction, and vasoconstriction. 

Acknowledgements

   The authors wish to thank Kimberly Bursk, R.N. and the staff at the American Red Cross donor centers.  Ms. Bursk was instrumental in assisting with the collection of data and the completion of this study.   

Literature Cited

Franchini, M., Targher, G., Montagnana, M., Lippi, G.  Iron and thrombosis.  Annals of Hematology 87 (#): 167-173. 

Haberthur, C., Schachinger, H., Seeberger, M., Gysi, C.S. Effect of Non-Hypotensive on Plasma Catecholamine Levels and Cardiovascular Variability in Man. Clinical Physiology and Functional Imaging 23 (#):159-165.

Jawan, B., Cheng, Y.F., Tseng, C.C., Chen, Y.S., Wang, C.C., Huang, T.L., Eng, H.L., Liu, P.P., Chiu, K.W., Wang, S.H., Lin, C.C., Lin, T.S., Liu, Y.W., Chen, C.L. 2005. Effect of Autologous Blood Donation on the Central Venous Pressure, Blood Loss and Blood Transfusion During Living Donor Left Hepatectomy. World Journal of Gastroenterology 11 (#): 4233-4236.

Mancia, G., Parati, G., Pomidossi, G., Casadei, R., Casadei, R., Di Rienzo, M., Zanchetti, A. 1986. Arterial Baroreflexes and Blood Pressure and Heart Rate Variabilities in Humans. Hypertension 8 (#): 147-153.

McGuill, M. W., Rowan, A. N. 1989.  Biological Effects of Blood Loss: Implications for Sampling Volumes and Techniques.  ILAR Journal Online 31 (#):  . 

Meyers, D. G., Strickland, D., Maloley, P. A., Seburg, J., Wilson, J. E., McManus, B. F.  1997.  Possible association of a reduction in cardiovascular events with blood donation 78 (#): 188-193. 

Parati, G., Di Rienzo, M., Bertiniere, G., Pomidossi, G., Casadei, R., Groppelli, A., Pedotti, A., Zanchetti, A, and Mancia, G.  1988.  Evaluation of the baroreceptor-heart rate reflext by 24-hour intra-arterial blood pressure monitoring in humans.  Hypertension 12 (#): 214-222. 

Peckerman, A., LaManca, J., Qureishi, B., Dahl, K., Golfetti, R., Yamamoto, Y., Natelson, B.  2003.  Baroceptor Reflext and Integrative Street Responses in Chronic Fatigue Syndrome.  Psychosomatic Medicine 65 (#): 889-895. 

Peng, T.C., Liao, K.W., Lai, H.L., Chao, Y.F.C., Chang, F.M., Harn., H., Lee, R.P. 2006. The Physiological Changes of Cumulative Hemorrhagic Shock in Conscious Rats. Journal of Biomedical Science 13 (#): 385-394.

Salonen, J., Toumainen, T., Salonen, R., Lakka, T., Nyyssonen, K. 1998. Donation of blood is associated with reduced risk of myocardial infarction.  American Journal of Epidemiology 148 (#): 445-451. 

Schadt, J.C., Hasser, E., M. 2005.  Hemodynamic effects of blood loss during a passive response to a stressor in the conscious rabbit.  American Journal of Physiology – Regulatory, Integrative and Comparative Physiology 286 (#): R373-R380. 

Sesso, H.D., Stampfer, M.J., Rosner, B., Hennekens, C.H., Gaziano, J.M., Manson, J.E., Glynn, R.J. 2000. Systolic and Diastolic Blood Pressure, Pulse Pressure, and Mean Arterial Pressure as Predictors of Cadiovascular Disease Risk in Men. Hypertension 36 (#): 801-807.

Velasquez, M.T., Menitove, J.E., Skelton, M.M., Cowley, A.W. 1987.  Hormonal responses and blood pressure maintenance in normal and hypertensive subjects during acute blood loss.  Hypertension 9 (#): 423-428. 

**I see the volume # for each of your sources, but not the edition number which should be in parenthesis; for example:

Pausas, Juli G., Keeley, Jon E. (2009). A Burning Story: The Role of Fire in the History of Life. Bioscience. 59(7), 593-601, 9. Retrieved from .

Review Form

Department of Biological Sciences

Saddleback College, Mission Viejo, CA 92692

Author (s): Stephanie Melton and Jessica Ochoa

Title: The effect of blood donation frequency and gender on physiological response to blood loss

Summary

Summarize the paper succinctly and dispassionately. Do not criticize here, just show that you understood the paper.

This paper was comparing first time donors and frequent donors with several different hypotheses. The first hypothesis tested was comparing the change in systolic blood pressure (bp) in frequent and first time donors. The second hypothesis tested was change in diastolic bp in frequent and first time donors. The third hypothesis tested was change in heart rate (hr) when compared to frequent and first time donors. The fourth hypothesis tested was the change in mean arterial pressure (MAP). The fifth hypothesis being tested was change in systolic bp compared genders of frequent donors. The sixth hypothesis tested was the change in systolic bp compared genders of first time donors. The seventh hypothesis tested was the change in diastolic bp compared genders of frequent donors. The eighth hypothesis tested was the change in diastolic bp compared genders of first time donors. The ninth hypothesis tested was the change in hr comparing genders of frequent donors. The tenth hypothesis tested was the change in hr comparing genders of first time donors. The eleventh hypothesis being tested was the change in MAP comparing the genders of frequent donors. The twelfth hypothesis was comparing the change in MAP comparing the genders of first time donors. In all the hypothesizes tested there was no difference.

General Comments

Generally explain the paper’s strengths and weaknesses and whether they are serious, or important to our current state of knowledge.

- Is MAP for all subjects or just an individual? I saw in the methods and materials that you had 30 first-time donors and 30 frequent donors. In your stats your sample size was N=11. Were you not able to use all 30? Why?

- This paper was written very well. Great sources and for the most part had good info about everything. I think though that this paper was a little longer than it needed to be. There we a lot of tests done just to show there were no differences.

Technical Criticism

Review technical issues, organization and clarity. Provide a table of typographical errors, grammatical errors, and minor textual problems. It's not the reviewer's job to copy Edit the paper, mark the manuscript.

X This paper was a final version This paper was a rough draft

[pic]

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download