Leg tegumental glands and male rubbing behavior at leks inPolistes Dominulus (Hymenoptera: Vespidae)

1991 ◽  
Vol 4 (4) ◽  
pp. 449-462 ◽  
Author(s):  
Laura Beani ◽  
Carlo Calloni
Keyword(s):  
Author(s):  
Moisés Gonzálvez ◽  
Carlos Martínez-Carrasco ◽  
Marcos Moleón

AbstractHigh infection risk is often associated with aggregations of animals around attractive resources. Here, we explore the behavior of potential hosts of non-trophically transmitted parasites at mesocarnivore carcass sites. We used videos recorded by camera traps at 56 red fox (Vulpes vulpes) carcasses and 10 carcasses of other wild carnivore species in three areas of southeastern Spain. Scavenging species, especially wild canids, mustelids and viverrids, showed more frequent rubbing behavior at carcass sites than non-scavenging and domestic species, suggesting that they could be exposed to a higher potential infection risk. The red fox was the species that most frequently contacted carcasses and marked and rubbed carcass sites. Foxes contacted heterospecific carcasses more frequently and earlier than conspecific ones and, when close contact occurred, it was more likely to be observed at heterospecific carcasses. This suggests that foxes avoid contact with the type of carcass and time period that have the greatest risk as a source of parasites. Overall, non-trophic behaviors of higher infection risk were mainly associated with visitor-carcass contact and visitor contact with feces and urine, rather than direct contact between visitors. Moreover, contact events between scavengers and carnivore carcasses were far more frequent than consumption events, which suggests that scavenger behavior is more constrained by the risk of acquiring meat-borne parasites than non-trophically transmitted parasites. This study contributes to filling key gaps in understanding the role of carrion in the landscape of disgust, which may be especially relevant in the current global context of emerging and re-emerging pathogens. Graphical abstract


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247964
Author(s):  
Andrea T. Morehouse ◽  
Anne E. Loosen ◽  
Tabitha A. Graves ◽  
Mark S. Boyce

Several species of bears are known to rub deliberately against trees and other objects, but little is known about why bears rub. Patterns in rubbing behavior of male and female brown bears (Ursus arctos) suggest that scent marking via rubbing functions to communicate among potential mates or competitors. Using DNA from bear hairs collected from rub objects in southwestern Alberta from 2011–2014 and existing DNA datasets from Montana and southeastern British Columbia, we determined sex and individual identity of each bear detected. Using these data, we completed a parentage analysis. From the parentage analysis and detection data, we determined the number of offspring, mates, unique rub objects where an individual was detected, and sampling occasions during which an individual was detected for each brown bear identified through our sampling methods. Using a Poisson regression, we found a positive relationship between bear rubbing behavior and reproductive success; both male and female bears with a greater number of mates and a greater number of offspring were detected at more rub objects and during more occasions. Our results suggest a fitness component to bear rubbing, indicate that rubbing is adaptive, and provide insight into a poorly understood behaviour.


2021 ◽  
Author(s):  
Timo Heitmann ◽  
Ole Geisen ◽  
Lisa Hühn ◽  
Oliver Munz ◽  
Andreas Bardenhagen

Abstract Laser Powder Bed Fusion (L-PBF) enables the production of complex metallic parts. Processes using pulsed wave (PW) laser radiation have been proven to be well suited to build thin-walled honeycomb structures. However, the behavior of these structures under load conditions remains mostly unexplored. The objective of this paper is to characterize L-PBF produced honeycombs by investigating their rub and leakage performance. A pulse modulated process based on previous studies is optimized for productivity and used to build L-PBF test samples out of Inconel 625 (IN625). The honeycomb cell geometry is adjusted for improved printability of the overhanging walls. Repeatable L-PBF production of honeycombs with a wall thickness of about 100 μm is confirmed. Conventionally manufactured honeycomb samples out of sheet metal are tested as reference. The rub experiments cover radial incursion rates of up to 0.5 mm/s and relative velocities of up to 165 ms−1 at incursion depths (ID) between 0.5 and 2.0 mm. Lower incursion forces are observed for the L-PBF components, with a higher degree of abrasion. The leakage tests examine the mass flow rate for pressure ratios between 1.05 and 2.0 at constant gap size and constant back pressure. The L-PBF honeycomb seals show a higher mass flow rate, with the slightly larger cell size and higher surface roughness appearing to be the main influencing factors. Overall, improved rubbing behavior and 10 % higher leakage than the conventional probes demonstrate the applicability of L-PBF for honeycomb sealing systems. Future performance improvements through dedicated L-PBF designs can be expected.


2008 ◽  
Vol 70 (2) ◽  
pp. 161-168 ◽  
Author(s):  
H. Meunier ◽  
O. Petit ◽  
J.-l. Deneubourg

Wear ◽  
2018 ◽  
Vol 410-411 ◽  
pp. 25-33 ◽  
Author(s):  
Weihai Xue ◽  
Siyang Gao ◽  
Deli Duan ◽  
Jiaping Zhang ◽  
Yang Liu ◽  
...  

2016 ◽  
Vol 71 (7-8) ◽  
pp. 209-214 ◽  
Author(s):  
Juliane C. Silva ◽  
Larissa A.R.O. Macedo ◽  
Grasielly R. Souza ◽  
Raimundo G. Oliveira-Junior ◽  
Sarah R.G. Lima-Saraiva ◽  
...  

Abstract Annona vepretorum Mart. (Annonaceae) is a species popularly known in Brazil as “araticum” and “pinha da Caatinga”. We have evaluated the antinociceptive effects of A. vepretorum in formalin-, capsaicin-, and glutamate-induced orofacial nociception in mice. Male Swiss mice were pretreated with either saline (p.o.), A. vepretorum ethanol extract (Av-EtOH 25, 50 and 100 mg/kg, p.o.), or morphine (10 mg/kg, i.p.), before formalin, capsaicin, or glutamate was injected into the right upper lip. Pre-treatment with Av-EtOH at all doses produced a reduction in face-rubbing behavior induced by formalin in both phases, and these pre-treatments also produced a significant antinociceptive effect in the capsaicin and glutamate tests. Pre-treatment with naloxone (1.5 mg/kg, i.p.) did not reverse the antinociceptive activity of the extract at the dose of 100 mg/kg in the first phase of this test. Our results suggest that Av-EtOH might be useful in the treatment of orofacial pain.


Author(s):  
Ulrich Rathmann ◽  
Sven Olmes ◽  
Alex Simeon

Performance and efficiency optimization is one of the major tasks in the turbo machinery industry. Therefore efforts for scientific and technical improvements focus on optimization and reduction of losses. Secondary losses are of major interest because of their parasitic character related to stage efficiency and power output. One of these losses is over tip leakage of blades. Common practice is a minimization of this clearance with abrasive/abradable combinations. With this technique the blade tip (abrasive material) can rub into its counterpart (heat-shield, abradable material on casings or liners) and therefore minimize the operating tip-clearance. This technology is well established in compressor and turbine engineering since many years [1]. Field experience shows that abrasive/abradable systems do not always work as intended. In some cases rubbing conditions are reversed so that the intended abradable cuts into the abrasive. Any benefit on operating tip-clearance will then be minor at best or even negative. Rubbing behavior is difficult to predict, especially for new materials or geometries where no experience is available. In close cooperation with the University of Applied Sciences Rapperswil (Switzerland), ALSTOM has developed a test rig that allows simulating engine-operating conditions and therefore evaluate abrasive/abradable combinations before actual implementation into an engine. The rig is designed to reproduce circumferential velocities and incursion rates that are typical for gas turbine engines in the compressor as well as in the turbine. Forces and temperatures are measured as quantitative data, visual appearance and metallographic condition of test specimens are recorded as qualitative data that allow a more detailed assessment of material combinations and operating conditions. This paper describes the design of a high-speed wear rig facility to test single blade and fully shrouded rub configurations. In addition the validation of the test rig against real engine experience and knowledge is shown.


2002 ◽  
Vol 46 (6) ◽  
pp. 924-925 ◽  
Author(s):  
Maria DeJoseph ◽  
R.S.L. Taylor ◽  
Mary Baker ◽  
Manuel Aregullin

PLoS ONE ◽  
2010 ◽  
Vol 5 (2) ◽  
pp. e8957 ◽  
Author(s):  
Olivier Roux ◽  
Johan Billen ◽  
Jérôme Orivel ◽  
Alain Dejean

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