Western scrub-jays anticipate future needs independently of their current motivational state

Planning for the future has been considered to be a uniquely human trait [1-3]. However, recent studies challenge this hypothesis by showing that food-caching Western scrub-jays (Aphelocoma californica) can relate their previous experience as thieves to the possibility of future cache theft by another bird [4], are sensitive to the state of their caches at recovery ([5] and S. De Kort, S.P.C.C., D. Alexis, A.D., and N.S.C., unpublished data), and can plan for tomorrow's breakfast [6]. Although these results suggest that scrub-jays are capable of future planning, the degree to which these birds act independently of their current motivational state is a matter of contention. The Bischof-K?hler hypothesis [1] holds that nonhuman animals cannot anticipate and act toward the satisfaction of a future need not currently experienced or cued by their present motivational state. Using specific satiety to control for the jays' current and future motivational states, here we specifically test this hypothesis by dissociating current and future motivational states. We report that Western scrub-jays anticipate the recovery of their caches, as well as their own future needs, by acting independently of their current motivational state and immediate needs. The fact that the birds act in favor of a future need as opposed to the current one challenges the hypothesis that this ability is unique to humans.     

Use of cryopreserved transiently transfected cells in high-throughput pregnane X receptor transactivation assay

Cryopreserved, transiently transfected HepG2 cells were compared to freshly transfected HepG2 cells for use in a pregnane X receptor (PXR) transactivation assay. Assay performance was similar for both cell preparations; however, cryopreserved cells demonstrated less interassay variation. Validation with drugs of different PXR activation potencies and efficacies demonstrated an excellent correlation (r(2) > 0.95) between cryopreserved and fresh cells. Cryopreservation did not change the effect of known CYP3A4 inducers that have poor cell permeability, indicating that cryopreservation had little effect on membrane permeability. In addition, cryopreserved HepG2 cells did not exhibit enhanced susceptibility to cytotoxic compounds compared to transiently transfected control cells. The use of cryopreserved cells enables this assay to run with enhanced efficiency.     

Compounds from silicones alter enzyme activity in curing barnacle glue and model enzymes

Background

Attachment strength of fouling organisms on silicone coatings is low. We hypothesized that low attachment strength on silicones is, in part, due to the interaction of surface available components with natural glues. Components could alter curing of glues through bulk changes or specifically through altered enzyme activity.

Methodology/Principal Findings

GC-MS analysis of silicone coatings showed surface-available siloxanes when the coatings were gently rubbed with a cotton swab for 15 seconds or given a 30 second rinse with methanol. Mixtures of compounds were found on 2 commercial and 8 model silicone coatings. The hypothesis that silicone components alter glue curing enzymes was tested with curing barnacle glue and with commercial enzymes. In our model, barnacle glue curing involves trypsin-like serine protease(s), which activate enzymes and structural proteins, and a transglutaminase which cross-links glue proteins. Transglutaminase activity was significantly altered upon exposure of curing glue from individual barnacles to silicone eluates. Activity of purified trypsin and, to a greater extent, transglutaminase was significantly altered by relevant concentrations of silicone polymer constituents.

Conclusions/Significance

Surface-associated silicone compounds can disrupt glue curing and alter enzyme properties. Altered curing of natural glues has potential in fouling management.     

FEMORAL NECK FRACTURES IN THE AGED

Clinical data were reviewed on 99 patients with 102 fractures of the femoral neck on the Orthopedic Service of the San Diego County General Hospital. All were elderly. Twenty-one were dead within two month of the time the fracture was reduced and 36 within a year. In 14 cases the fracture was impacted or undisplaced; there was only one of these in which the fracture did not unite following treatment, and that was for iatrogenic reasons. Sixty-one per cent of the displaced fractures healed; only 32 per cent of the total number of patients with displaced femoral neck fractures walked again.     

A New and Practical Oral Contraceptive Agent: Norethindrone with Mestranol

The usefulness of a new oral contraceptive compound containing norethindrone 5 mg. and mestranol 0.075 mg. (Ortho-Novum) was studied. One hundred and seventeen private patients used this preparation for a total of 998 menstrual cycles. There were no pregnancies. Side effects were minimal and caused few (11 patients) to discontinue use. The most significant of these was weight gain and a premenstrual tension syndrome including nausea, breakthrough bleeding and skin effects. Other symptoms were minor and easily controlled. Instruction in use of the preparation is easy. Patient acceptance is excellent. Possible masculinizing effects, liver damage, or harmful effects on the uterus were checked specifically by laboratory evaluation; no significant abnormal findings were noted.This appears to be an effective oral contraceptive which is well accepted by the patient and which produced no serious side effects as used in this study.