Epizootic rabbit enteropathy. Study of early phenomena with fresh inoculum and attempt at inactivation

[EN] Using 180 35-day-old SPF rabbits, this study used the effectiveness of bacitracin as a tool for acquiring more information on the various phases of ERE, in particular during the hours inoculation. Five groups of animals were used, including 3 treatments with Bacivet S(R) (bacitracin) at different times from inoculation, with the standard inoculum TEC3. Three parameters were studied: growth, mortality and stomach noises (borborygmi). A significant fall in growth rate was observed during the first 18 hours following the inoculation in all the inoculated groups, both medicated and not medicated. Treatment with bacitracin eliminated mortality and borborygmi, but not the initial fall in growth rate. Treatment starting 18 hours after inoculation is less effective during the acute phase than the preventive treatment. With a preventive treatment interrupted as soon as 18 hours after inoculation, a delay of several days was observed before the appearance of the disease (fall in growth rate, manifestation of borborygmi) and total mortality was reduced. Very few pathogens can explain this early fall in growth rate. Bacitracin is an antibiotic which offers good control of the disease, and probably of the pathogen but not of the physio-pathological disturbances in the first few hours. The intervention of an exogenic toxin in the first hours of contamination seems likely. Borborygmi are important criteria. The intensity and/or frequency could be used as semi-quantitative criteria to characterize the disease and for the prognosis. In a simultaneous trial, a group was contaminated with the same inoculum, heated for 10 min at 55°C, in order to obtain more information on the type of pathogen involved in the etiology of ERE. This treatment did not modify the virulence of the inoculum.This research received financial help from the Ministry for Agriculture of France (DGAL - ITAVI).Coudert, P.; Licois, D. (2005). Epizootic rabbit enteropathy. Study of early phenomena with fresh inoculum and attempt at inactivation. World Rabbit Science. 13. doi:10.4995/wrs.2005.515SWORD1

Subjectivity in bio-logging science: do logged data mislead?

Logging of data using animal-attached archival units (bio-logging) involves potential sources of subjectivity that are reviewed in the present paper. Subjectivity may be the result of technical limitations of which the selection of the correct sampling frequency is particularly critical. Mistakes or aberrant data can also result from transitory defaults in the loggers functioning. Similarly, the use of purpose-written software to pre-process logged data before analysis is another step during which substantial modification of the raw data can occur. Apart from technical limitations, bio-logging devices are also known to modify the behaviour of the animal studied. Finally, arbitrary conclusions can eventually be drawn out from the \u27visual\u27 analysis of logged-data. The second part of this review proposes a non-exhaustive list of precautions so as to enhance objectivity in bio-logging approach. Among these precautions, assessment of the impact that data-logger may have on the animal, appropriate calibrations (for example for transformation of the raw measurements into useable variables) and multi-data sampling are useful steps in bio-logging utilization

Subjectivity in bio-logging: do logged data mislead?

Logging of data using animal-attached archival units (bio-logging) involves potential sources of subjectivity that are reviewed in the present paper. Subjectivity may be the result of technical limitations of which the selection of the correct sampling frequency is particularly critical. Mistakes or aberrant data can also result from transitory defaults in the loggers functioning. Similarly, the use of purpose-written software to pre-process logged data before analysis is another step during which substantial modification of the raw data can occur. Apart from technical limitations, bio-logging devices are also known to modify the behaviour of the animal studied. Finally, arbitrary conclusions can eventually be drawn out from the ‘visual’ analysis of logged-data. The second part of this review proposes a nonexhaustive list of precautions so as to enhance objectivity in bio-logging approach. Among these precautions, assessment of the impact that data-logger may have on the animal, appropriate calibrations (for example for transformation of the raw measurements into useable variables) and multi-data sampling are useful steps in bio-logging utilization

Patterns of energy acquisition by penguins: benefits of alternating short and long foraging trips.

In some seabirds, foraging trips have been defined as either long or short, with the length of time spent traveling to the foraging area apparently a critical feature in determining foraging trip length. Using logger technology, together with complimentary data from published studies, we investigated traveling and foraging times in 18 free-living Adélie Penguins Pygoscelis adeliae, which were foraging for chicks. Most deep, foraging dives were distributed around the center of the foraging trip. This central tendency was particularly apparent if the cumulative amount of undulations in the depth profile (indicative of prey capture) was considered during deep dives; values started to increase before 20.9% and ceased after 67.2% of the dives had occurred. This concentration of the feeding activity in the middle of the foraging trip indicates that birds traveled to and from a prey patch whose location varied little over the birds' trips. These data form the basis for a simple model that uses traveling and foraging times together with projected rates of prey ingestion and chick and adult gastric emptying to determine that there are occasions when, to optimize rates of prey ingestion while at sea for both adults and chicks, birds should conduct foraging trips of bimodal lengths

Two-photon double ionization of neon using an intense attosecond pulse train

We present the first demonstration of two-photon double ionization of neon using an intense extreme ultraviolet (XUV) attosecond pulse train (APT) in a photon energy regime where both direct and sequential mechanisms are allowed. For an APT generated through high-order harmonic generation (HHG) in argon we achieve a total pulse energy close to 1 $\mu$J, a central energy of 35 eV and a total bandwidth of $\sim30$ eV. The APT is focused by broadband optics in a neon gas target to an intensity of $3\cdot10^{12}$W$\cdot$cm$^{-2}$. By tuning the photon energy across the threshold for the sequential process the double ionization signal can be turned on and off, indicating that the two-photon double ionization predominantly occurs through a sequential process. The demonstrated performance opens up possibilities for future XUV-XUV pump-probe experiments with attosecond temporal resolution in a photon energy range where it is possible to unravel the dynamics behind direct vs. sequential double ionization and the associated electron correlation effects

Foraging areas of king penguins (Aptenodytes patagonicus) breeding at Possession Island in the Southern Indian Ocean

Between January and March 1994 and between January and June 1995 we used Global Location Sensors(GLS) to determine the feeding areas of King Penguins Aptenodytes patagonicus breeding at Possession Island, Crozet Archipalago. In both years, the preferred feeding area during summer was located about 300 km south of the island, being slightly more distant in 1995. Mean foraging trip duration was 5.7±1.1 days (n = 6) during summer 1994 and 8.9±3.7 days (n = 9) during summer 1995, respectively. During summer the travelling speed of the King Penguins studied was highest at the first and last days of the foraging trip (c. 8 km/h). During the middle days of foraging trips travelling speeds were much lower (< 5 km/h). In early winter, between late April and mid-June 1995, two King Penguins equipped with GLSs executed foraging trips with durations of 53 and 59 days, respectively. Both birds travelled beyond 60°S with maximum distances to the colony of 1600 and 1800 km, respectively, and total distances covered of about 5000 km. The winter trips were characterized by alternating periods of higher and lower distances covered, indicating a highly variable feeding success at different localities. The relationships between foraging trip duration (days) and maximum distance to the colony (km) and total distance covered (km) were calculated to be maximum distance = 210 + 27 d and total distance = 340 + 85 d

Production et morbidité des lapines reproductrices: étude comparative de quatre génotypes

Sur un cheptel de 223 lapines de 4 génotypes (CA = Californien, NZ = Néo-Zélandais Blanc et leurs croisements réciproques), sont analysés sur une année la fonte du cheptel, l'évolution de l'état sanitaire et leurs relations avec la production. Les conditions expérimentales sont caractérisées par une prophylaxie hygiénique rigoureuse et l'absence de prophylaxie médicale et de traitement. Après un an, deux tiers des femelles ont disparu. Cela est dû pour moitié à la mortalité qui survient sur des femelles en bon état sanitaire global et à l'élimination, due à l'apparition de phénomènes irréversibles : torticolis, mammites, cachexie. A côté de ces symptômes, 2 phénomènes morbides ont entraîné peu d'élimination : les rhinites et maux de pattes. Ils apparaissent à des moments différents de la carrière des femelles mais tous deux évoluent avec leur stade physiologique : aggravation lorsqu'elles sont allaitantes et gestantes et amendement lorsqu'elles sont uniquement allaitantes jusqu'à 10 jours après la mise bas. Il apparaît des différences de comportement sanitaire entre génotypes : comparativement aux CA, les 3 génotypes ayant un parent NZ ont en commun un taux de mortalité plus faible et une cause principale d'élimination non spécifique (cachexie). A l'inverse, comparativement aux NZ, les 3 génotypes