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Age is a consistent predictor of poor outcome following traumatic brain injury (TBI). Although the elderly population has one of the highest rates of TBI-related hospitalization and death, few preclinical studies have attempted to model and treat TBI in the aged population. Recent studies have indicated that nicotinamide (NAM), a soluble B-group vitamin, improved functional recovery in experimental models of TBI in young animals. The purpose of the present study was to examine the preclinical efficacy of NAM in middle-aged rats. Groups of middle-aged (14-month-old) rats were assigned to NAM (500 mg/kg or 50 mg/kg) or saline alone (1 mL/kg) treatment conditions, and received unilateral cortical contusion injuries (CCI) and injections at 1 h and 24 h following injury. The animals were tested on a variety of tasks to assess vestibulomotor (tapered beam) and cognitive performance (reference and working memory in the Morris water maze), and were evaluated for lesion size, blood-brain barrier compromise, astrocytic activation, and edema formation. In summary, the preclinical efficacy of NAM as a treatment following CCI in middle-aged rats differs from that previously documented in younger rats; while treatment with 50 mg/kg NAM appeared to have no effect, the 500-mg/kg dose worsened performance in middle-aged animals. Histological indicators demonstrated more nuanced group differences, indicating that NAM may positively impact some of the cellular cascades following injury, but were not substantial enough to improve functional recovery. These findings emphasize the need to examine potential treatments for TBI utilizing non-standard populations, and may explain why so many treatments have failed in clinical trials.

Data from seven research resource flocks across Australia were combined to provide accurate estimates of genetic correlations among production traits in Merino sheep. The flocks represented contemporary Australian Merino fine, medium and broad wool strains over the past 30 years. Over 110,000 records were available for analysis for each of the major wool traits, and 50,000 records for reproduction and growth traits with over 2700 sires and 25,000 dams. Individual models developed from the single trait analyses were extended to the various combinations of two-trait models to obtain genetic correlations among six wool traits [clean fleece weight (CFW), greasy fleece weight, fibre diameter (FD), yield, coefficient of variation of fibre diameter and standard deviation of fibre diameter], four growth traits [birth weight, weaning weight, yearling weight (YWT), and hogget weight] and four reproduction traits [fertility, litter size, lambs born per ewe joined, lambs weaned per ewe joined (LW/EJ)]. This study has provided for the first time a comprehensive matrix of genetic correlations among these 14 wool, growth and reproduction traits. The large size of the data set has also provided estimates with very low standard errors. A moderate positive genetic correlation was observed between CFW and FD (0.29 +/- 0.02). YWT was positively correlated with CFW (0.23 +/- 0.04), FD (0.17 +/- 0.04) and LWEJ (0.58 +/- 0.06), while LW/EJ was negatively correlated with CFW (-0.26 +/- 0.05) and positively correlated with FD (0.06 +/- 0.04) and LS (0.68 +/- 0.04). These genetic correlations, together with the estimates of heritability and other parameters provide the basis for more accurate prediction of outcomes in complex sheep-breeding programmes designed to improve several traits.

Conventional methods have long been used to record electroretinograms (ERGs) from the surface of the lateral eye of Limulus, the horseshoe crab. But, using these methods, the convexity of this eye has sometimes led to electrode problems that deterred acceptance of the validity of unexpected and unfamiliar phenomena. To deal with the electrode problem, a new gel/bellows cup electrode has been devised which was created from a small bellows suction cup. Coated with a recording gel and positioned by a massive apparatus arrangement, it maintains a secure connection to the convexity of the lateral eye for many days without requiring any attention after its placement. This new electrode has now been used for thousands of hours of ERG research during which crabs have often been left undisturbed in the apparatus for many days. This new method has revealed the existence of a novel low-frequency phenomenon demonstrated by the occurrence of noise-like fluctuations in successive ERGs. The frequency of these fluctuations is low relative to the properties of the ERG itself. Several converging tests of this new electrode system indicated that this new phenomenon is not an artifact but rather a genuine expression of endogenous bioelectric events.

Samples were taken from the duodenum of young pigs via indwelling catheters after ingestion of liquid meals. They had been deprived of feed and water overnight. Samples were taken every minute for 15 min and then at 20, 25, 30, 40, 50, and 60 min. After ingestion of hypertonic glucose solutions, duodenal osmolality rose rapidly to maximal levels within 10-15 min when osmoconcentrations were as follows: for 10% glucose, 480 mosmol/kg H2O; for 20%, 680; and for 40%, 1,200. After 5% glucose, osmolality was about 280 mosmol/kg H2O and did not change appreciably during the hour. Water ingestion caused a fall to 60 mosmol/kg H2O at 3 min and then a slow recovery. Ingestion of glucose-in-milk solutions gave similar but slightly higher values. When the glucose-in-water or -milk solutions were ingested just before a meal of feed pellets, meal size was depressed proportional to glucose concentration.