12 resultados para powerful owl

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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It has been proposed that gonadotropins and/or gonadotropin releasing hormone (GnRH) could be involved in the pathophysiology of the side effects after spaying in bitches, such as urinary incontinence and an increased production of a woolly undercoat. In order to provide tools to investigate the role of these hormones in dogs we developed immunohistochemical techniques and real-time RT-PCR to study whether GnRH-, LH-, and FSH-receptors exist in canine skin and urinary bladder. Tissue samples from the skin of the flank region and the ventral midline of the urinary bladder from euthanised dogs were examined. We were able to quantify mRNA expression of GnRH-, FSH-, and LH-receptors in canine skin and bladder biopsies with a high primer efficacy. Immunohistochemical studies showed that GnRH-, FSH-, and LH-receptors are expressed in vessel walls, the epidermis, the hair follicle and in sebaceous and sweat glands in canine skin and in transitional epithelium, and smooth muscle tissue in the urinary bladder. Our data provide the fundamentals to examine the distribution of FSH-, LH-, and GnRH-receptors in canine skin and urinary bladder and to assess gene activity at the transcriptional level by real-time RT-PCR.

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Current theory proposes that nestlings beg to signal hunger level to parents honestly, or that siblings compete by escalating begging to attract the attention of parents. Although begging is assumed to be directed at parents, barn owl (Tyto alba) nestlings vocalize in the presence but also in the absence of the parents. Applying the theory of asymmetrical contests we experimentally tested three predictions of the novel hypothesis that in the absence of the parents siblings vocally settle contests over prey items to be delivered next by a parent. This 'sibling negotiation hypothesis' proposes that offspring use each others begging vocalization as a source of information about their relative willingness to contest the next prey item delivered. In line with the hypothesis we found that (i) a nestling barn owl refrains from vocalization when a rival is more hungry, but (ii) escalates once the rival has been fed by a parent, and (iii) nestlings refrain from and escalate vocalization in experimentally enlarged and reduced broods, respectively. Thus, when parents are not at the nest a nestling vocally refrains when the value of the next delivered prey item will be higher for its nest-mates. These findings are the exact opposite of what current models predict for begging calls produced in the presence of the parents. [References: 20]

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Ophioluxin, a potent platelet agonist, was purified from the venom of Ophiophagus hannah (King cobra). Under nonreducing conditions it has a mass of 85 kDa, similar to convulxin, and on reduction gives two subunits with masses of 16 and 17 kDa, slightly larger than those of convulxin. The N-terminal sequences of both subunits are very similar to those of convulxin and other C-type lectins. Ophioluxin induces a pattern of tyrosine-phosphorylated proteins in platelets like that caused by convulxin, when using appropriate concentrations based on aggregation response, because it is about 2-4 times more powerful as agonist than the latter. Ophioluxin and convulxin induce [Ca(2+)](i) elevation both in platelets and in Dami megakaryocytic cells, and each of these C-type lectins desensitizes responses to the other. Convulxin agglutinates fixed platelets at 2 microg/ml, whereas ophioluxin does not, even at 80 microg/ml. Ophioluxin resembles convulxin more than echicetin or alboaggregin B because polyclonal anti-ophioluxin antibodies recognize both ophioluxin and convulxin, but not echicetin, and platelets adhere to and spread on ophioluxin- or convulxin-precoated surfaces in the same way that is clearly different from their behavior on an alboaggregin B surface. Immobilized ophioluxin was used to isolate the glycoprotein VI-Fcgamma complex from resting platelets, which also contained Fyn, Lyn, Syk, LAT, and SLP76. Ophioluxin is the first multiheterodimeric, convulxin-like snake C-type lectin, as well as the first platelet agonist, to be described from the Elapidae snake family.

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We have investigated genetic parentage in a Swiss population of tawny owls (Strix aluco). To this end, we performed genetic analysis for six polymorphic loci of 49 avian microsatellite loci tested for cross-species amplification. We found one extra-pair young out of 137 (0.7%) nestlings in 37 families (2.7%). There was no intra-specific brood parasitism. Our results are in accordance with previous findings for other raptors and owls that genetic monogamy is the rule. Female tawny owls cannot raise offspring without a substantial contribution by their mates. Hence one favoured hypothesis is that high paternal investment in reproduction selects for behaviour that prevents cuckoldry.

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PURPOSE: We assessed the efficacy of extracorporeal shock wave lithotripsy (ESWL, Dornier Medical Systems, Inc., Marietta, Georgia) for distal ureteral calculi with the HM3 (Dornier Medical Systems, Inc.) lithotriptor. MATERIALS AND METHODS: A total of 585 consecutive patients with distal ureteral calculi were treated with ESWL using an unmodified HM3 lithotriptor. Of these patients 67 referred for treatment only for whom no followup was available were excluded from further analysis. The remaining 518 cases were followed until they were radiologically documented to be stone-free or considered treatment failures. Before ESWL additional procedures were performed in 144 patients, including stone push back, ureteral catheter or Double-J (Medical Engineering Corp., New York, New York) stent placement, percutaneous nephrostomy, ureteral endoscopic maneuvers or stone basket manipulation. A total of 374 patients needed no preliminary treatment before ESWL. RESULTS: Of the 518 patients 469 (91%) were successfully treated with 1 ESWL session, while 49 (9%) needed 2 or 3. Manipulation after ESWL was performed in 22 cases, including stent placement, percutaneous nephrostomy, ureteral endoscopic stone removal and a stone basket procedure. On day 1 after ESWL 327 patients (63%) were stone-free, 158 (30%) had less than 5 mm. fragments and 33 (7%) had more than 5 mm. fragments. At 3 months the stone-free rate increased to 97%. CONCLUSIONS: These data show that ESWL for distal ureteral calculi with the powerful unmodified HM3 lithotriptor has a high success rate with a low rate of minimally traumatic manipulations before and after intervention. Results in terms of the re-treatment and stone-free rates are superior to those of any other second or third generation lithotriptor and comparable to the results of the best ureteroscopic series.

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Previous research has shown that power increases focus on the main goal when distractor information is present. As a result, high-power people have been described as goal-focused. In real life, one typically wants to pursue multiple goals at the same time. There is a lack of research on how power affects how people deal with situations in which multiple important goals are present. To address this question, 158 participants were primed with high or low power or assigned to a control condition, and were asked to perform a dual-goal task with three difficulty levels. We hypothesized and found that high-power primed people prioritize when confronted with a multiple-goal situation. More specifically, when task demands were relatively low, power had no effect; participants generally pursued multiple goals in parallel. However, when task demands were high, the participants in the high-power condition focused on a single goal whereas participants in the low-power condition continued using a dual-task strategy. This study extends existing power theories and research in the domain of goal pursuit.