Gas chromatographic analysis of curing smokes

Summary It is nowadays possible, by direct gas chromatography, to separate the components of smoke as their ether extracts. The use of a chromatograph equiped with an Argon ionization detector and a programmed temperature heated oven makes it possible to obtain results of a precision unknown up to now. But the problem remains still so the control of smoke curing operation will be made possible only when all the peaks of the chromatogram have been identified.

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Zusammenfassung Mit direkter Gaschromatographie kann man heute die Bestandteile des Gazes in Form ihrer aetherischen Auszüge trennen. Die Verwendung des Argon-Ionisationsdetektors und eines temperaturprogrammierten Säulenofens verleiht dem gaschromatographischen Verfahren eine bisher unerreichte Genauigkeit. Die Untersuchung auf diesem Gebiete sind jedoch nicht abgeschlossen. Die Anwendung dieses Verfahrens zur Kontrolle der Verdampfungsvorgänge kann erst vorgenommen werden, wenn sämtliche Chromatogrammspitzen identifiziert sind.

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Résumé Il est possible actuellement, à l'aide de la chromatographie directe, en phase gazeuse, de séparer les composants de la fumée sous forme de leurs extraits à l'éther. L'emploi de chromatographes munis de détecteurs d'ionisation à Argon et de fours colonne avec chauffage à température programmée permet d'obtenir des résultats d'une précision inconnue jusqu'ici. Le problème n'est cependant pas épuisé et l'application de cette méthode au contrôle des opérations de fumage ne pourrait s'effectuer qu'après l'identification complète de tous les pics du chromatogramme.

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with 3 figs.     

Effect of diets on growth and reproductive development of juvenile pikeperch, Stizostedion lucioperca (L.), reared under intensive culture conditions

Juvenile pikeperch 3.66 ± 0.23 cm total length (TL) and 0.32 ± 0.05 g were reared in water at 22 ± 0.5^°C and fed with live zooplankton or alternatively a commercial trout feed. Fish fed with dry diet grew faster and had higher condition factor than fish fed live zooplankton. Sex differentiation in pikeperch was visible at different stages of ontogenesis, but was related to the fish growth rate. The gonads offish that were 3.43-5.69 cm TL revealed undifferentiated characteristics. Clear indication of oogenesis in females was observed in pikeperch at 7.9 cm TL and 3.47 g, whereas evident spermatogenesis was not observed till the end of the experiment.     

An application of temperature mapping of horse's back for leisure horse‐rider‐matching

Leisure riding is a popular way of using horses however, unlike sport or racing horses, those are mostly not associated with one rider with high skills. Constant overload of equine musculoskeletal system causes pathologies, which are affecting horse mobility and decreases the horse‐rider communication. The aim was to propose the new scoring system of thermograph analysis as an aspect of differences in heat distributions on horseback before and after leisure ridings. The study was conducted on sixteen Polish warmblood horses, scanned with a non‐contact thermographic camera. Heat pattern of the thoracolumbar area was evaluated on thermograms taken before and after exercise. The criteria with point values for horse‐rider‐matching were created: heat points on the dorsal midline of saddle‐back contact area and degree of muscle unit overload. The results of thermograph analysis were compared with the results of a questionnaire on horse‐rider communication during riding in order to estimate the relevance of matching. The maximum score was obtained in 38.3% and 39.8% of combinations based on the thermograph analysis and questionnaire, respectively. Results of both scoring systems were strongly positive correlated (r = .937), demonstrating high sensitivity (61.72%) and specificity (90.23%) of the matching. The horse‐rider matching may improve horse comfort during leisure type of work.     

Meiotic gynogenesis affects the individual and gonadal development in sterlet Acipenser ruthenus

Larval growth and gonadal differentiation of gynogenetic sterlet Acipenser ruthenus were studied. The gynogenetic fish were produced by activation of albino sterlet eggs with UV‐irradiated sperm (collected from healthy coloration specimens), following by a heat shock of 34°C. Embryos were reared at 18.0 ± 0.5°C in a recirculation system and initially fed with Artemia sp. for 4 weeks and then fed with formulated feed. During the experiment, the length and weight of fish were recorded for the gynogenetic and control groups. Additionally, the analysis of gonadal sex differentiation was conducted with a 2‐week interval at 289, 303, 317, 331, 345 and 373 DPH. The mean body weight of the control group was significantly higher (p < .05) than the gynogenetic group only at 345 and 373 DPH, while the mean total body length was significantly higher at 331 and 345 DPH (p < .05). The gonad investigation was started at 289 DPH, and ~80% of females were found in the gynogenetic group during the trial period while the number of females and males was similar at 303, 331 and 373 DPH in the control group. The first symptoms of morphological differentiation appeared at 289 DPH, and the final shaping macroscopic structure of the gonad took place earlier in females than in males.     

Effect of 17 α-methyltestosterone on gonadal differentiation in pikeperch, Stizostedion lucioperca L.

Morphological and histological studies demonstrated that 17 α-methyltestosterone (MT) affects sex differentiation and can be used to control the phenotypic sex of pikeperch. Stizostedion lucioperca L. Treatment (for 21 days) of pikeperch (initially 2.2 g wet weight) with MT at 30 mg kg^-1 diet induced germ cells inversion in approximately 46.67% of individuals (although 96.67% of the fish were classified as males). An increase in treatment duration (60 and 90 mg kg^-1) increased the percentage of female, intersex and sterile fish. Slower growth rates of all the fish treated with MT in comparison to the control groups were demonstrated. However, no significant differences in conditions and mortalities between the MT treated fish and controls were observed.     

Induction of Out-of-Season Spawning of Pikeperch, Sander Lucioperca (L.)

Pikeperch were induced to spawn 3 months prior to the natural spawning period through photothermal and hormonal stimulation. Females (five specimens in each group) were stimulated with injection of human chorionic gonadotropin (hCG) once (200 IU kg^–1), twice (200 IU kg^–1, second dose after 48 h–400 IU kg^–1) or three times (200 IU kg^–1, after 24 h–200 IU kg^–1 and after another 24 h–200 IU kg^–1). The control group was injected once with 0.9% NaCl. The males were stimulated with a single hormone dose of 200 IU kg^–1. Eggs were obtained from all the hormonally treated fish. None of the control group females, which were only stimulated photothermally, ovulated any eggs. The time of ovulation was 66–71 h following the first injection, and the eggs viability until the eyed stage (from 71.5 to 77.5%) did not depend on the number of hormone doses (P > 0.05). The out-of-season spawning method described in this paper could be used to provide pikeperch larvae for intensive culture systems (recirculating water systems) before natural spawning season and to produce larger-sized pikeperch fingerlings for stocking.     

Characterization of Gelatinolytic Activity in Seminal Plasma of Some Teleost Fish

Gelatin-containing SDS-PAGE combined with the incubation of gels in buffers containing protease inhibitors was performed for the visualization and characterization of proteolytic activity in teleost fish seminal plasma. To demonstrate the class of detected enzymes we used serine protease inhibitor – benzamidine or EDTA which inhibits metalloproteases activity. Additionally the effects of calcium ions on protease activity were investigated. Multiple gelatinolytic activities in seminal plasma of 10 teleost fish species from three orders (Cypriniformes, Salmoniformes, Perciformes) were found. Most proteases were either stimulated by Ca²⁺ and inhibited by EDTA or inhibited by benzamidine. This suggests that metalloproteases and serine proteases are major gelatinolytic proteases of fish seminal plasma. In cyprinid species we found a common profile of two gelatinolytic activities; the first band (60–66 kDa) belonged to metalloproteases, and the second one (76–81 kDa) belonged to serine proteases. Other bands were also visible and they represented mostly serine protease activity. Species from the Salmoniformes order showed a similarity in metalloproteases with molecular weights of about 64 and 75 kDa. Salmonid species also had similar serine proteases with molecular weights of about 102 and 165 kDa. In European grayling seminal plasma we found metalloproteases with molecular weight of 51, 57, 64, 70 kDa and two serine proteases activities of 35 and 125 kDa. Percid species had metalloproteases activities of 53 and 63 kDa and serine protease activity of 100 kDa. Protease of other, presently unknown classes were also found in seminal plasma of asp, chub, European grayling and pikeperch. The physiological role of seminal plasma proteases is still unknown.     

The effect of 11 β-hydroxyandrostenedione on pikeperch Stizostedion lucioperca (L.)

Oral administration of 11 β-hydroxyandrostenedione was used to sex inverse juvenile Stizostedion lucioperca (L.) reared under intensive culture conditions. Androgen was mixed into the commercial trout food in the following doses: 0, 30, 60 and 90 mg kg^?1 diet. Administration (for 21 days) of 60 mg 11 β-hydroxyandrostenedione kg^?1 of the diet produced 93% males and 7% bisexual fish. In hormone-treated groups, no morphological changes were observed in the liver. No significant differences were observed in growth or in the hepatosomatic index between the androgen-treated groups and the control group.