Physiological effects of arginine vasotocin and mesotocin in cockerels

1. The effects of continuous infusion of 0.1, 1.0 and 10.0 mU/min/kg body weight of arginine vasotocin (AVT) or mesotocin (MT) on cardiovascular and thermoregulatory responses, on plasma osmolality and ionic composition and on plasma concentrations of AVT, MT, prolactin and aldosterone, were investigated in conscious White Leghorn cockerels.

2. Neither of the peptides, at any dose, affected cardiovascular functions, plasma ions and osmolality. Infusion of MT at the rate of 10 mU/min/kg body weight increased respiratory rate. Both peptides at doses of 1 and 10 mU/min/kg reduced the temperatures of the comb and shank but had no effect on the skin and cloaca.

3. Doses of 0.1 and 1.0 mU MT/mu/kg reduced plasma aldosterone and at 10 mU/min/kg increased plasma AVT. At any given dose MT had no effect on plasma prolactin. AVT at 0.1 and 1.0 mU/min/kg of AVT reduced plasma MT. AVT at 1.0 mU/min/kg increased plasma prolactin and at 10 mU/min/kg reduced plasma aldosterone.

4. During saline infusion, plasma MT was positively correlated with plasma AVT and negatively correlated with respiratory rate and cloacal temperature. Plasma AVT showed a positive correlation with plasma MT and aldosterone and a negative correlation with respiratory rate and skin temperature.

5. During saline infusion, there was no significant correlation between cardiovascular functions, or plasma osmolality and ionic composition and plasma MT or AVT.

6. The present study suggests that interrelationships between circulating concentrations of AVT and MT do exist and that AVT affects     

五种微卫星DNA标记在肉牛群体中的研究

选择了分布在牛的4条染色体上的5个微卫星DNA标记IDVGA-2,IDVGA-27,IDVGA-46,IDVGA-55及TGLA-44,分析其在所供牛群体中的多态分布情况。结果表明,每个位点的等位基因个数及多态信息含量值分别为12/0.82,5/0.58,8/0.70,6/0.57和11/0.86。全部标记经半同胞家系检验,均符合孟德尔遗传规律。     

Phage sensitivity in relation to pathogenicity and virulence of the cotton bacterial blight pathogen of Sudan

At least two pathotypes of Xanthomonas campestris pv. malvacearum are now known to exist in Sudan. The pre-Barakat (race 1) and post-Barakat (race 2) pathogens have been shown to exhibit different host specificity. The former is pathogenic and highly aggressive on only cultivars with no resistance genes or with the B₂ and/or B₃ resistance factors, while the latter can infect the B₆ cultivars also. Race 2 in Sudan, which was previously reported to infect all the standard differentials, produced milder angular leaf spot symptoms and occasionally restricted vein infection. Moreover, it exhibited reduced growth in planta compared with race 1.
Bacteriophage studies revealed that the two races are quite distinct in their phage sensitivity. Race 1 can be lysed by only three, or rarely four, of the six phages used for typing, while race 2 is sensitive to all of them. The present study suggests that phage 7 may be the type-determining phage for race 2. Race 2 strain mutants resistant to phage 3 or 4 were found to be sensitive to phage 7 and pathogenic to both Acala and Barakat, although showing marked attenuation of virulence. However, mutants resistant to phage 2 or 7 were insensitive to all the phages and although they retained their pathogenicity to Acala, they either lost the ability to infect Barakat or produced a hypersensitive reaction. The resistance of all mutants was found to be due to failure to adsorb the homologous phage, indicating a change in the cell wall. The association of this with the attenuation of virulence suggests that bacterial wall components may function as virulence determinants in Xanthomonas campestris pv. malvacearum.     

Effect of a single injection of gonadotropin-releasing hormone (GnRH) and human chorionic gonadotropin (hCG) on testicular blood flow measured by color doppler ultrasonography in male Shiba goats

Although color Doppler ultrasonography has been used to evaluate testicular blood flow in many species, very little has been done in goat. Eight male Shiba goats were exposed to a single intramuscular injection of either gonadotropin-releasing hormone (GnRH group; 1 µg/kg BW) or human chorionic gonadotropin (hCG group; 25 IU/kg BW). Plasma testosterone (T), estradiol (E2) and inhibin (INH) were measured just before (0 hr) and at different intervals post injection by radioimmunoassay. Testis volume (TV) and Doppler indices, such as resistive index (RI) and pulsatility index (PI) of the supratesticular artery, were measured by B-mode and color Doppler ultrasonography, respectively. The results indicated an increase in testicular blood flow in both groups, as RI and PI decreased significantly (P<0.05), but this increase was significant higher and earlier in hCG group (1 hr) than in the GnRH group (2 hr). A high correlation was found for RI and PI with both T (RI, r= −0.862; PI, r= −0.707) and INH in the GnRH group (RI, r=0.661; PI, r=0.701). However, a significant (P<0.05) correlation was found between E2 and both RI (r= −0.610) and PI (r= −0.763) in hCG group. In addition, TV significantly increased and was highly correlated with RI in both groups (GnRH, r= −0.718; hCG, r= −0.779). In conclusion, hCG and GnRH may improve testicular blood flow and TV in Shiba goats.     

Boldenone, boldione, and milk replacers in the diet of veal calves: the effects of phytosterol content on the urinary excretion of boldenone metabolites

Twenty-six veal calves were split into two groups and fed two milk replacers with a different content of phytosterols for 26 days; then, 14 calves (7 animals from each diet) were kept as controls and 12 calves (6 per diet) received daily, per os, a combination of 17beta-boldenone (17beta-Bol) and androsta-1,4-dien-3,17-dione (ADD) for 38 days. The urinary elimination of 17 alpha-/17beta-boldenone conjugates (17 alpha/beta-Bol) and androsta-1,4-dien-3,17-dione (ADD) was followed by liquid chromatography-tandem mass spectrometry from all of the animals until slaughtering. In urine from treated animals, 17 alpha-Bol concentrations, despite a great variability, were greater than 17beta-Bol, both detected always as conjugates. At days 1, 2, and 3, the mean urine concentration of 17 alpha-Bol was higher than 12 ng/mL. A remarkable decrease was observed during the following days, but the 17 alpha-Bol concentration was still higher than the attention level of 2 ng/mL in 58% of the samples; the concentration of 17beta-Bol was around the action level of 1 ng/mL; two days after treatment withdrawal, no 17beta-Bol was detected in the urine. In urine from control animals, the 17 alpha-Bol concentration was strictly related to the phytosterol content of the diet, while, in urine from treated animals, the much higher 17 alpha-Bol levels were not modified by the production from diet precursors. The results confirmed that a 17 alpha-Bol level higher than 2 ng/mL should be considered as evidence of suspected illegal treatment and that the urinary excretion of 17beta-Bol is due to exogenous administration of 17beta-Bol. The discontinuous rate of elimination of both 17 alpha- and 17beta-Bol, despite the daily administration of 17beta-Bol plus ADD, indicates the necessity for further research to detect other urinary boldenone metabolites to strength surveillance strategy.     

Reconstructing the history of the sand tiger shark (Carcharias taurus) in the Mediterranean Sea

1. Sharks are globally exposed to several anthropogenic threats, which, in many cases, have severely reduced their distribution and have impacted populations. In the Mediterranean Sea, because of its long history of exploitation and the relatively short span of scientific monitoring, reconstructing shark baselines is challenging. Many vulnerable species declined in population abundance and geographic distribution before it was possible to adequately track these changes. Consequently, for many of these species, current conservation assessments are now suffering from a severe case of shifting baseline syndrome, whereby their historical occurrence in the area is questioned.
2. The sand tiger shark (Carcharias taurus) is one of these cases. Characterized by high philopatry, restricted home range, and low interchange between populations, its Mediterranean population may have been severely impacted by the high historical fishing pressure in the region before scientific monitoring began.
3. In this study, the history of the abundance and distribution of C. taurus in the Mediterranean Sea was reconstructed through a comprehensive search of occurrence records in the literature and in museum collections. Between 1810 and 2008, 31 occurrence records and 54 publications provided information on the presence of the species in the area. These records were sparse but systematic over time and indicated occurrence hot spots in the south‐western Mediterranean Sea and in the eastern Adriatic Sea.
4. The presence of ten sightings of juveniles from a total of 18 sightings with length information suggested local parturition. Habitat and extinction models indicate that the area has suitable oceanographic conditions for the occurrence of the species and that the species cannot be considered extinct in the Mediterranean Sea. Our study suggests that there is still hope for the recovery of the species and underlines the crucial role of historical investigations to reconstruct the history of large elasmobranchs in the Mediterranean Sea.

     

Actor-Network-Theory perspective on a forestry decision support system design

Use of decision support systems (DSS) has thus far been framed as a social process of adoption or technical process of usability. We analyze the development of a DSS as a process of institutionalization of new as well as drift of existing practices. We write an Actor-Network-Theory (ANT) account, i.e. an interpretive study, that follows the traces left by both human and non-human actors (e.g. technology, methodologies, etc.) to understand how a DSS development project institutionalizes DSS technology in several forest management organizations in the German state of Rheinland Pfalz. The research has an innovative value since it uses ANT in the design of a DSS, hence affecting it, while commonly ANT has been used to understand why networks work or do not. Moreover, we use a new technology (PREZI^TM, www.prezi.com) for the visualization of the whole actor network coherent to the ANT methodology, i.e. “keeping the social flat.” As a result, the development of the ANT account proposed in the present paper, even if still partial, supports the design of new technologies being introduced in current practice and generates an important learning effect thanks to the underpinning interpretative approach.