memory functions of the prefrontal cortex

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I need to understand the memory functions of the prefrontal cortex

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JOURNALOFNEUROPHYSIOLOGY Vol. 6 1, No. 2. February 1989. Printed in U&4. Mnemonic Coding of Visual Space in the Monkey’s Dorsolateral Prefrontal Cortex SHINTARO FUNAHASHI, CHARLES J. BRUCE, AND PATRICIA S. GOLDMAN-RAKIC Section of Neuroanatomy, Yale University School of Medicine, New Haven, Connecticut 06510 SUMMARY AND CONCLUSIONS 1. An oculomotor delayed-response task was used to examine the spatial memory functions of neurons in primate prefrontal cortex. Monkeys were trained to fixate a central spot during a brief presentation (0.5 s) of a peripheral cue and throughout a subsequent delay period (l-6 s), and then, upon the extinction of the fixation target, to make a saccadic eye movement to where the cue had been presented. Cues were usually presented in one of eight different locations separated by 45O. This task thus requires monkeys to direct their gaze to the location of a remembered visual cue, controls the retinal coordinates of the visual cues, controls the monkey’s oculomotor behavior during the delay period, and also allows precise measurement of the timing and direction of the relevant behavioral responses. 2. Recordings were obtained from 288 neurons in the prefrontal cortex within and surrounding the principal sulcus (PS) while monkeys performed this task. An additional 31 neurons in the frontal eye fields (FEF) region within and near the anterior bank of the arcuate sulcus were also studied. 3. Of the 288 PS neurons, 170 exhibited task-related activity during at least one phase of this task and, of these, 87 showed significant excitation or inhibition of activity during the delay period relative to activity during the inter-trial interval. 4. Delay period activity was classified as div~tional for 79{0e601fc7fe3603dc36f9ca2f49ef4cd268b5950ef1bbcf1f795cc00e94cdd119} of these 87 neurons in that significant responses only occurred following cues located over a certain range of visual field directions and were weak or absent for other cue directions. The remaining 2 1{0e601fc7fe3603dc36f9ca2f49ef4cd268b5950ef1bbcf1f795cc00e94cdd119} were omnidirectional, i.e., showed comparable…

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What have been the experiences of the hospital/s in relation to: suspected medical device-related deaths, medical device –related injuries, and other medical device-related adverse events, and how were these addressed?

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Integrating theory and research needs assessment

The Safety Medical Devices Act of 1990 was enacted by Congress to increase the amount of information the Federal Drug Administration (FDA) and suppliers receive from users on malfunctions, adverse events, and critical problems with medical devices. Despite the regulation enacted, studies show that there has been widespread underreporting of such events. FDA reports explicitly noted that less than 1{0e601fc7fe3603dc36f9ca2f49ef4cd268b5950ef1bbcf1f795cc00e94cdd119} of device problems occurring in hospitals have been brought to their attention.

It was further found that the more serious the problem with the device, the less likely that it is reported. This indicates a large number of hospitals and other medical units have been advertently withholding such very significant information to proper government authorities. This could have been made because of fears that their hospitals may suffer the consequences, but to the detriment of the patients and the public.

The effects of withholding critical information will have adverse effects in the short and long terms. Suppliers may continue producing and gaining profits out of products and services that have been causing death and injuries to innocent people.Hospitals with sub-standard medical devices handled and operated by medical personnel and practitioners with sub-standard knowledge, skills, and competencies would continue to exist and gain profit, but at the same time continue destroying the lives and quality of family life of many.

Medical errors, also called “adverse events,” include missed and delayed diagnoses, mistakes during treatment, medication mistakes, delayed reporting of results, miscommunications during transfers and transitions in care, inadequate postoperative care, and mistaken identity. Patient safety also encompasses the concept of “reliability.” Reliability in health care is defined as patients getting the intended tests, medications, information, and procedures at the appropriate time and in accordance with their values and preferences. System-derived errors can occur when clinicians are tired after working long hours, stressed or cutting corners because they are in a hurry. Environmental factors like noise and lighting can distract clinicians. Mistakes also can be made because of a lack of standardized equipment and practices. For example, it is easy to understand how a patient can be administered the wrong medication if two different medicine vials look the same and the doctor is in a hurry when grabbing a medication. Providing clearly labeled, color-coded bottles or storing similar-looking vials in separate locations can help prevent mistakes like these from recurring (Patrick et al, 2008).

Research problem

This research project intends to determine the degree of compliance of the Patton – Fuller CommunityHospital with the Safe Medical Devices and policies and procedures in ensuring the safety of medical devices used.

The research questions are

1.What are the basic medical reporting requirements, policies, and procedures imposed by FDA on hospitals along the following?

Suspected medical device –related deaths

Medical device – related serious injuries

Other medical device-related adverse events

2.What have been the experiences of the hospital/s in relation to: suspected medical device-related deaths, medical device –related injuries, and other medical device-related adverse events, and how were these addressed?

3.How may the existing adverse – event reporting system of Patton – Fuller CommunityHospital be described along the aforementioned variables (Robbins & Coulter, 2002).

4.To what extent has the hospital been complying to the policies and procedures imposed by the FDA in accordance with:

1Medical Device Act of 1990,

2Medical devices amendments of 1992, and

3State-specific requirements?

5.How may the findings be used by FDA in further reviewing its Safe Medical Devices Act and in further improving the effectiveness of the implementation of the corresponding policies, procedures, and processes?

Hypothesis

1.There is a significant difference between the degree of compliance to Medical Device Reporting imposed by FDA and the extent of compliance of hospitals, particularly, Patton – FullerCommunity Hospital.

Significance of the study

1.Protect Patients and families. The results of the study may help the hospital to improve its services and be careful in the use of its medical devices.

2.Benefit hospital management and administration. This study would reveal some loopholes in their operations, particularly in the implementation of policies and procedures in relation to the use of their medical devices.

3.Benefit medical device suppliers. The adverse discovered through this study will be important feedback that would be used in further improving the products

4.Benefit the government. This research could help the government in monitoring and evaluating the implementation of the Safe Medical Devices Act of 1990, including its amendments.

How would this misclassification affect the estimate of the causal effect of statin on mortality?

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There are 6 questions to be answered after reading an article. It’s about epidemiologic study designs.

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Reading the article in the following website and answer the six questions below:
http://aulafarmacologica.com/wp-content/uploads/2012/11/Las-Estatinas-Reducen-la-Mortalidad-por-C{0e601fc7fe3603dc36f9ca2f49ef4cd268b5950ef1bbcf1f795cc00e94cdd119}C3{0e601fc7fe3603dc36f9ca2f49ef4cd268b5950ef1bbcf1f795cc00e94cdd119}A1ncer-2012.pdfhttp://aulafarmacologica.com/wp-content/uploads/2012/11/Las-Estatinas-Reducen-la-Mortalidad-por-C{0e601fc7fe3603dc36f9ca2f49ef4cd268b5950ef1bbcf1f795cc00e94cdd119}C3{0e601fc7fe3603dc36f9ca2f49ef4cd268b5950ef1bbcf1f795cc00e94cdd119}A1ncer-2012.pdf
1. Statin use information was obtained from prescriptions filled at Danish pharmacies. However, no information was available on whether individuals took the medicine they were prescribed. Could this lead to exposure misclassification / measurement error? Would the error be differential or non-differential? Independent from the outcome or dependent? How would this misclassification affect the estimate of the causal effect of statin on mortality?
2. Page 1794, second column. The authors describe that, in addition to the main analysis including all individuals with cancer, they also performed a matched analysis, selecting 3 non-statin users for each statin user matched for sex, age at cancer diagnosis, year of diagnosis, and cancer type. Did this matching increase exchangeability between statin users and never users? Explain your answer using the information provided in Table 1.
3. In page 1796, first column, Statistical analysis. “Multivariable Cox models were adjusted for age, …, and size of residential area”. What is the purpose of adjusting for these variables?
4. Briefly explain whether the following conditions for identifiability of effects are achieved and how (e.g. in the study design, in the analysis; and if in the design or in the analysis, how exactly, etc.):
a. Positivity ;
b. Consistency ;
c. Exchangeability .
5. The Figure in page 1800 presents results for different stratified analysis. Using the information in the figure, describe the association between statin use and mortality by presence of ‘chemotherapy’. Would your qualitative assessment of the interacion have been different if instead of hazard ratios the figure had used rate…

Bias in Epidemiologic Research

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Bias in Epidemiologic Research

For the following study descriptions, describe potential bias(es) most likely to be present. Indicate how the bias would affect the measure of association (would it be underestimated, overestimated or unchanged):

1. A cohort study was designed to look at the association of pesticides and the occurrence of childhood leukemia. Children living in rural areas were followed and leukemia rates were compared between those children living in areas with high and low pesticide exposure.

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Bias in Epidemiologic Research

For the following study descriptions, describe potential bias(es) most likely to be present. Indicate how the bias would affect the measure of association (would it be underestimated, overestimated or unchanged):

1. A cohort study was designed to look at the association of pesticides and the occurrence of childhood leukemia. Children living in rural areas were followed and leukemia rates were compared between those children living in areas with high and low pesticide exposure. Pesticide exposure was considered high if it was over 20 “units” and low if it was under 20 “units.” The method used to quantify pesticide exposure was accurate to within +/- 12 units.

2. Persons diagnosed as HIV positive or negative were interviewed about their number of lifetime sexual partners. The interviews occurred after they were told their HIV status.

3. A cohort study looked at the association of exposure to PCBs in the workplace and the occurrence of cancer over 20 years. At the 10-year follow-up, 15{0e601fc7fe3603dc36f9ca2f49ef4cd268b5950ef1bbcf1f795cc00e94cdd119} of the original participants could not be located to assess their disease status.

4. In a clinical trial of a new drug, the intervention group received the medicine and outcomes were assessed by a doctor working for the pharmaceutical company. The placebo group received the placebo and outcomes were assessed by a doctor from the local community hospital.

ollow-up, 15{0e601fc7fe3603dc36f9ca2f49ef4cd268b5950ef1bbcf1f795cc00e94cdd119} of the original participants could not be located to assess their disease status.

4. In a clinical trial of a new drug, the intervention group received the medicine and outcomes were assessed by a doctor working for the pharmaceutical company. The placebo group received the placebo and outcomes were assessed by a doctor from the local community hospital.

ng in rural areas were followed and leukemia rates were compared between those children living in areas with high and low pesticide exposure. Pesticide exposure was considered high if it was over 20 “units”…