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Michael D Mann

Publications and source records attributed to Michael D Mann.

9 recordsLinked to original sources
PubMed2007

Verification of IACUC approval and the just-in-time PHS grant process.

Public Health Service Policy requires institutional animal care and use committees (IACUCs) to review and approve the animal care and use aspects of grant proposals submitted for funding. Initially, submission of verification of approval was required with submission of the proposal; however, in 2002, a ''just-in-time'' (JIT) process was begun to allow submission when it appeared that the proposal would be in the fundable range. After 3 yr, no evaluation of JIT and its impact on the IACUC has been published. An online survey designed by the authors to determine this impact is described. Invitations to participate in the survey were sent to 1002 IACUC chairs and administrators, and responses were received from 168. Surprisingly, 30% of respondents indicated that they did not review grant proposals at all. The majority of those respondents reported that they rely on principal investigator assurance that approved IACUC protocols match grant proposals. In the authors' experience, this procedure is not safe 23% of the time, and several respondents described the same experience. Most respondents indicated that they use JIT whenever possible for all investigators. Of those who reviewed grant proposals, most indicated that each review consumes 20 to 29 min, and most respondents indicated that the granting agency does not allow enough time for a JIT verification to complete a de novo submission and review of a protocol. Instead, the protocol must have been submitted and reviewed prior to the JIT request. Respondents indicated that there is considerable uncertainty about what the granting agency would do when an IACUC requires changes in a protocol during the JIT process.

Animal Care Committees↗
PubMed2006

Application of gold catalyst for mercury oxidation by chlorine.

This paper discusses a recent study of mercury catalytic oxidation by chlorinating reagents. Gold was chosen as the catalyst because of its reluctance to chemisorb some gases such as O2, NO, H2O, and SO2. This property, as demonstrated in this study, is instrumental to mercury oxidation by circumventing some undesired inhibitory reactions such as OH + NO + M --> HONO + M and OH + SO2 + M --> HOSO2 + M, which were recognized under homogeneous situations at high temperatures. In comparison to Cl2, HCl showed weak oxidizing capability but appreciable inhibition in mercury oxidation by Cl2, probably through the competition of active sites with Cl2. Overall, the mercury catalytic oxidation by Cl2 on gold catalyst surfaces was viable, reaching 40-60% in this study under temperatures of 448-498 K, where the thermal decomposition of formed Hg2+ was effectively avoided.

Catalysis↗
PubMed2006

Effects of sulfur dioxide and nitric oxide on mercury oxidation and reduction under homogeneous conditions.

This paper is particularly related to elemental mercury (Hg0) oxidation and divalent mercury (Hg2+) reduction under simulated flue gas conditions in the presence of nitric oxide (NO) and sulfur dioxide (SO2). As a powerful oxidant and chlorinating reagent, Cl2 has the potential for Hg oxidation. However, the detailed mechanism for the interactions, especially among chlorine (Cl)-containing species, SO2, NO, as well as H2O, remains ambiguous. Research described in this paper therefore focused on the impacts of SO2 and NO on Hg0 oxidation and Hg2+ reduction with the intent of unraveling unrecognized interactions among Cl species, SO2, and NO most importantly in the presence of H2O. The experimental results demonstrated that SO2 and NO had pronounced inhibitory effects on Hg0 oxidation at high temperatures when H2O was also present in the gas blend. Such a demonstration was further confirmed by the reduction of Hg2+ back into its elemental form. Data revealed that SO2 and NO were capable of promoting homogeneous reduction of Hg2+ to Hg0 with H2O being present. However, the above inhibition or promotion disappeared under homogeneous conditions when H2O was removed from the gas blend.

Air Pollutants↗
PubMed2004

Prolonged gastric emptying half-time and gastric hypomotility after drug overdose.

A prospective study was undertaken to determine if gastric motility and emptying are altered by the ingestion of overdoses of tricyclic antidepressants, acetaminophen, opioid-acetaminophen mixtures, carbamazepine or phenytoin. Gastric scintigraphy was used to measure gastric emptying half-time and assess gastric motility in 104 patients at initial presentation and again at follow-up (n = 85). Patients were imaged for 5 hours after being given 20 MBq of 99mTc tin colloid to drink. Drug serum levels were measured on all patients at initial presentation and at follow-up. We observed markedly prolonged gastric emptying half-times and severe hypomotility at initial presentation compared with follow-up in the vast majority of patients, except for a small group of patients with phenytoin poisoning. Twelve patients had gastric emptying half-times of over 300 minutes, a further 14 had half-times of over 200 minutes and 21 others had half-times of over 120 minutes. Poisoning is associated with hypomotility and a marked delay in gastric emptying that could influence the clinical course and patient management. These abnormalities may not be due to a direct effect of the ingested drug and factors such as stress may play a role.

Acetaminophen↗
PubMed2004

Should IACUCs review scientific merit of animal research projects?

Whether IACUCs should review animal research protocols for scientific merit is not addressed in the federal regulations, resulting in ongoing confusion on the subject. The authors examine this issue, discuss the pros and cons, suggest how IACUCs can go about reviewing protocols for scientific merit, and question what effect recent changes in regulations will have on this issue.

Animal Care Committees↗
PubMed2003

Brain-body size relations in grasshopper mice.

Cranial volumes were measured on museum specimens of two species of grasshopper mice, Onychomys leucogaster brevicaudus and Onychomys torridus pulcher. These were compared with body weights and body lengths, as recorded on the museum tags. On average, females were heavier and slightly longer than males, but they had smaller cranial volumes by about 3%. Statistically, the differences were marginally significant (with no difference in body length for one species), but the pattern of differences was the same in both species, and therefore probably real. This casts suspicion on the common notion that a larger body size requires a larger brain. It also questions the real meaning of encephalization quotients.

Animals↗