Anesthesia of male axis deer (Axis axis): evaluation of thiafentanil, medetomidine, and ketamine versus medetomidine and ketamine.

Thiafentanil oxalate, previously known as A-3080, is a synthetic opioid used for chemical immobilization of a variety of nondomestic hoofstock species. This study compared the combination of thiafentanil oxalate, medetomidine, and ketamine (TMK; 0.09 +/- 0.02 mg/kg, 0.01 +/- 0.003 mg/kg, and 1.36 +/- 0.33 mg/kg, respectively) with the combination of medetomidine and ketamine (MK; 0.09 +/- 0.02 mg/kg and 3.48 +/- 0.55 mg/kg, respectively) for anesthetization of 17 captive male axis deer (Axis axis) for vasectomy. Nine deer received TMK and eight deer received MK via projectile syringe during the months of January and February, 2005. Mean induction and arousal times, vital signs, and arterial blood gas values were monitored and compared. All animals received supplemental oxygen during the surgical procedure. Animals receiving TMK were reversed with naltrexone (100 mg/mg thiafentanil) and atipamazole (5 mg/mg medetomidine). Animals receiving MK were reversed with atipamazole (5 mg/mg medetomidine). Two MK animals and three TMK animals required supplementation with ketamine i.v. immediately upon handling. Six of the nine animals immobilized with TMK required intubation for positive-pressure ventilation. Two of these six animals also required isoflurane to maintain anesthesia. Mean induction time was 3.5 +/- 2.0 min in the TMK group, and 9.8 +/- 6.7 min in the MK group. Despite shorter mean induction times, animals anesthetized with TMK experienced unpredictable inductions, apnea, muscle rigidity, limb movement, and significant respiratory and metabolic lactic acidosis. MK resulted in smoother inductions, better respiratory function, and less adverse metabolic disturbances, and thus was considered superior to TMK for anesthesia in captive axis deer at the dosages tested.     

Invasive slug populations (Arion vulgaris) as potential vectors for Clostridium botulinum

Background

Norwegian meadows, including those for silage production, are recently found heavily invaded by the slug Arion vulgaris in exposed areas. As a consequence, large numbers of slugs might contaminate grass silage and cause a possible threat to animal feed quality and safety. It is well known that silage contaminated by mammalian or avian carcasses can lead to severe outbreaks of botulism among livestock. Invertebrates, especially fly-larvae (Diptera), are considered important in the transfer of Clostridium botulinum type C and its toxins among birds in wetlands. C. botulinum form highly resistant spores that could easily be consumed by the slugs during feeding. This study aimed to determine whether Arion vulgaris could hold viable C. botulinum and enrich them, which is essential knowledge for assessing the risk of botulism from slug-contaminated silage. Slug carcasses, slug feces and live slugs were tested by a quantitative real-time PCR (qPCR) method after being fed ≅ 5.8 × 10⁴ CFU C. botulinum type C spores/slug.

Results

Low amounts of C. botulinum were detected by qPCR in six of 21 slug carcasses with an even spread throughout the 17 day long experiment. Declining amounts of C. botulinum were excreted in slug feces up to day four after the inoculated feed was given. C. botulinum was only quantified the first two days in the sampling of live slugs. The viability of C. botulinum was confirmed for all three sample types (slug carcasses, slug feces and live slugs) by visible growth in enrichment media combined with obtaining a higher quantification cycle (Cq) value than from the non-enriched samples.

Conclusions

Neither dead nor live invasive Arion vulgaris slugs were shown to enrich Clostridium botulinum containing the neurotoxin type C gene in this study. Slugs excreted viable C. botulinum in their feces up to day four, but in rapidly decreasing numbers. Arion vulgaris appear not to support enrichment of C. botulinum type C.     

Using 1-Hz GPS data to measure deformations caused by the Denali fault earthquake

The 3 November 2002 moment magnitude 7.9 Denali fault earthquake generated large, permanent surface displacements in Alaska and large-amplitude surface waves throughout western North America. We find good agreement between strong ground-motion records integrated to displacement and 1-hertz Global Positioning System (GPS) position estimates collected approximately 140 kilometers from the earthquake epicenter. One-hertz GPS receivers also detected seismic surface waves 750 to 3800 kilometers from the epicenter, whereas these waves saturated many of the seismic instruments in the same region. High-frequency GPS increases the dynamic range and frequency bandwidth of ground-motion observations, providing another tool for studying earthquake processes.     

Roles for mating and environment in C. elegans sex determination

In Caenorhabditis elegans the two sexes, hermaphrodites and males, are thought to be irreversibly determined at fertilization by the ratio of X chromosomes to sets of autosomes: XX embryos develop as hermaphrodites and XO embryos as males. We show instead that both sex and genotype of C. elegans can be altered postembryonically and that this flexibility requires sexual reproduction. When grown in specific bacterial metabolites, some XX larvae generated by mating males and hermaphrodites develop as males and lose one X chromosome. However, XX larvae produced by hermaphrodite self-fertilization show no such changes. We propose that sexual reproduction increases developmental flexibility of progeny, allowing for better adaptation to changing environments.