In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Context: Objective analysis of surgical skill is necessary. A novel method of assessment using simple error analysis in synthetic models is examined for construct validity.', 'Two examination protocols were devised using synthetic models. These contained either a purpose made error or were representative of good surgical practice. Protocol one contained models of skin closure and minor operations. Protocol two in addition more complex procedures. Face validity was established by the approval of senior surgeons. Junior surgeons were recruited to undertake the assessment. A p value of less than 0.05 was deemed to be significant.', 'Eighty-nine surgeons were recruited. Both protocol one and two were able to discriminate between groups at statistically significant levels.\Question: Is the surgical error examination a novel method for objective technical knowledge assessment?
Construct validity has been established by showing that error analysis is able to distinguish surgeons with varying levels of experience.

Context: To compare rates of undertriage and overtriage of six ambulance dispatch protocols for the presenting complaint of nontraumatic abdominal pain, and to identify the optimal protocol.', 'Retrospective prehospital and emergency department chart review to classify patients\' conditions as "emergency" or "nonemergency." Utility analysis was used to identify the preferred protocol and monetary cost-effectiveness analysis to identify the least expensive protocol.', 'County emergency medical services (EMS) system with five receiving hospitals serving a mainly urban population of approximately 350,000.', 'Records of 902 patients who called 911 for nontraumatic abdominal pain were reviewed; patients not transported were excluded. Twenty-seven county EMS medical directors completed questionnaires.', 'Six ambulance dispatch protocols for nontraumatic abdominal pain were developed: indiscriminate-dispatch, four selective protocols, and no-dispatch. A dichotomous classification system was derived prospectively from the prehospital and medical records of patients who had activated the EMS system before the study period to define "emergency" and "nonemergency" conditions associated with nontraumatic abdominal pain. Emergency criteria identified patients with conditions requiring medical treatment within 1 hour. Reviewers determined, for each patient, whether an ambulance would have been dispatched by each of the protocols. Undertriage and overtriage rates were calculated for each protocol. County EMS medical directors assigned utility values to four potential outcomes of ambulance dispatch by the direct scaling method. The outcomes comprised correct and incorrect decisions to dispatch ambulances to patients with and without emergencies. The protocols were compared by decision analysis. A cost analysis was also performed, using an estimated marginal cost per transport of $302. Sensitivity analysis demonstrated the effect of varying the cost of an undertriage error and the cost per response. Of the 788 patients included in the study, 7.8% had conditions defined as emergencies. The four selective ambulance dispatch protocols had overtriage rates ranging from 10% to 51% and undertriage rates of 4% to 7%. None of the protocols was proven superior on the basis of the medical directors\' assignment of utility values. The marginal cost of dispatching advanced life support ambulances to all patients with this complaint was $3,838 per emergency.\Question: Do comparison of ambulance dispatch protocols for nontraumatic abdominal pain?
The majority of patients with nontraumatic abdominal pain who requested ambulance transport during the study period did not have conditions that were classified as emergencies. In the study model, if an undertriage error costs more than $3,674, indiscriminate ambulance dispatch is the least expensive protocol, and if an undertriage error costs less than $3,674, no ambulance dispatch is the least expensive strategy.

Context: Changes in vascular permeability are well-known and important consequences of cerebral ischemia. The development of edema and of petechial hemorrhage is connected to altered vascular integrity. A major part in microvascular integrity is played by the basal lamina.', 'The fates of the basal lamina components laminin, fibronectin, and type IV collagen during middle cerebral artery occlusion (2 hours, n = 3) and occlusion (3 hours) with reperfusion (1 hour, n = 3; 4 hours, n = 3; and 24 hours, n = 4) were evaluated in the nonhuman primate. Specific monoclonal antibodies against these components were used. The number and size distribution of the microvessels in each specimen were determined by video-imaging microscopy, and the relative fluorescence intensity of laminin was semiquantified by laser confocal microscopy. Basal lamina antigen presentations were compared by double-stain immunofluorescence histochemistry.', 'The number of microvascular structures defined by the presence of each basal lamina antigen decreased significantly up to 24 hours of reperfusion (P < .0001). The ratio of laminin-containing vessels between the ischemic and nonischemic territories decreased significantly from control (0.98 +/- 0.04) to 2 hours of ischemia (0.83 +/- 0.09) and 1 hour (0.79 +/- 0.08), 4 hours (0.77 +/- 0.06), and 24 hours of reperfusion (0.55 +/- 0.07). The ratio of fibronectin (cellular) and of collagen (IV)-containing vessels decreased from 0.98 +/- 0.04 to 0.75 +/- 0.1 and from 1.02 +/- 0.03 to 0.57 +/- 0.1, respectively. Mean laminin fluorescence intensity decreased from 76.1 +/- 6.0 U (controls) to 52.0 +/- 14.6 U (24 hours of reperfusion; P < .001).\Question: Do microvascular basal lamina antigens disappear during cerebral ischemia and reperfusion?

The significant parallel losses of three basal lamina components, both in number and intensity, contribute to loss of microvascular integrity. These phenomena may be important for understanding cell extravasation and the hemorrhagic consequences of acute stroke.

