It Pays to Be Bumpy: Drag Reducing Armor in the Pacific Spiny Lumpsucker, Eumicrotremus orbis.

Armor is a multipurpose set of structures that has evolved independently at least 30 times in fishes. In addition to providing protection, armor can manipulate flow, increase camouflage, and be sexually dimorphic. There are potential tradeoffs in armor function: increased impact resistance may come at the cost of maneuvering ability; and ornate armor may offer visual or protective advantages, but could incur excess drag. Pacific spiny lumpsuckers (Eumicrotremus orbis) are covered in rows of odontic, cone-shaped armor whorls, protecting the fish from wave driven impacts and the threat of predation. We are interested in measuring the effects of lumpsucker armor on the hydrodynamic forces on the fish. Bigger lumpsuckers have larger and more complex armor, which may incur a greater hydrodynamic cost. In addition to their protective armor, lumpsuckers have evolved a ventral adhesive disc, allowing them to remain stationary in their environment. We hypothesize a tradeoff between the armor and adhesion: little fish prioritize suction, while big fish prioritize protection. Using micro-CT, we compared armor volume to disc area over lumpsucker development and built 3D models to measure changes in drag over ontogeny. We found that drag and drag coefficients decrease with greater armor coverage and vary consistently with orientation. Adhesive disc area is isometric but safety factor increases with size, allowing larger fish to remain attached in higher flows than smaller fish.

Delayed inhibition of Nogo-A does not alter injury-induced axonal sprouting but enhances recovery of cognitive function following experimental traumatic brain injury in rats.

Traumatic brain injury causes long-term neurological motor and cognitive deficits, often with limited recovery. The inability of CNS axons to regenerate following traumatic brain injury may be due, in part, to inhibitory molecules associated with myelin. One of these myelin-associated proteins, Nogo-A, inhibits neurite outgrowth in vitro, and inhibition of Nogo-A in vivo enhances axonal outgrowth and sprouting and improves outcome following experimental CNS insults. However, the involvement of Nogo-A in the neurobehavioral deficits observed in experimental traumatic brain injury remains unknown and was evaluated in the present study using the 11C7 monoclonal antibody against Nogo-A. Anesthetized, male Sprague-Dawley rats were subjected to either lateral fluid percussion brain injury of moderate severity (2.5-2.6 atm) or sham injury. Beginning 24 h post-injury, monoclonal antibody 11C7 (n=17 injured, n=6 shams included) or control Ab (IgG) (n=16 injured, n=5 shams included) was infused at a rate of 5 microl/h over 14 days into the ipsilateral ventricle using osmotic minipumps connected to an implanted cannula. Rats were assessed up to 4 weeks post-injury using tests for neurological motor function (composite neuroscore, and sensorimotor test of adhesive paper removal) and, at 4 weeks, cognition was assessed using the Morris water maze. Hippocampal CA3 pyramidal neuron damage and corticospinal tract sprouting, using an anterograde tracer (biotinylated dextran amine), were also evaluated. Brain injury significantly increased sprouting from the uninjured corticospinal tract but treatment with monoclonal antibody 11C7 did not further increase the extent of sprouting nor did it alter the extent of CA3 cell damage. Animals treated with 11C7 showed no improvement in neurologic motor deficits but did show significantly improved cognitive function at 4 weeks post-injury when compared with brain-injured, IgG-treated animals. To our knowledge, the present findings are the first to suggest that (1) traumatic brain injury induces axonal sprouting in the corticospinal tract and this sprouting may be independent of myelin-associated inhibitory factors and (2) that post-traumatic inhibition of Nogo-A may promote cognitive recovery unrelated to sprouting in the corticospinal tract or neuroprotective effects on hippocampal cell loss following experimental traumatic brain injury.

Seasonal transmission of Fasciola hepatica to cattle in northwestern United States.

Sentinel steers were placed with 3 beef herds on irrigated pastures in southern Idaho for 1-month periods from May until November 1982 to determine the transmission pattern of Fasciola hepatica. Transmission was found to increase through the pasture season, reaching a peak during November. Overwintering of metacercariae or snail-borne stages was not found to contribute to infections in the year under study. A variety of species of Lymnaea were found to be available in southern Idaho as potential intermediate hosts. The enzyme-linked immunosorbent assay was found to be a good serologic indicator of light infections with F hepatica. The serum gamma-glutamyltransferase activity was not diagnostically significant when the degree of fluke infection was low.

Pilferage of controlled substances in hospitals.

The incidence of pilferage of controlled substances and the systems of monitoring and surveillance of controlled substances in hospitals were studied. A questionnaire was mailed to a random samples of 285 pharmacy directors in short-term medical and surgical hospitals nationwide. Of the 162 respondents, 103 (64%) reported at least one documented or suspected case of pilferage in the past year. These 103 hospitals reported 352 separate incidence of controlled substances theft involving 11,285 dosage units. Drug diversion occurred in 76% of the hospitals with more than 100 beds and in only 28% of the hospitals with less than 100 beds. Nurses were implicated in 69% of the incidents; pharmacists and pharmacy technicians in 12%; housekeeping personnel in 4.7%; unit-ward clerks in 3.5%; and physicians in 2.4%. These incidents most frequency involved: meperidine, morphine, cocaine, oxycodone, hydromorphone, propoxyphene, pentazocine, diazepam, and codeine products. Larger hospitals, those with more frequent inventory audits, those that disperse controlled substances throughout their drug stock, and those that have more pharmacy personnel involved in the distribution of controlled substances all had a relatively higher incidence of pilferage. It was concluded that a substantial amount of pilferage of controlled substances occurs in hospitals and that more stringent methods of control and surveillance are needed.