| 3151. |
- Brydegaard, Mikkel, et al.
(författare)
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Can the narrow red bands of dragonflies be used to perceive wing interference patterns?
- 2018
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 8:11, s. 5369-5384
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Tidskriftsartikel (refereegranskat)abstract
- Despite numerous studies of selection on position and number of spectral vision bands, explanations to the function of narrow spectral bands are lacking. We investigate dragonflies (Odonata), which have the narrowest spectral bands reported, in order to investigate what features these narrow spectral bands may be used to perceive. We address whether it is likely that narrow red bands can be used to identify conspecifics by the optical signature from wing interference patterns (WIPs). We investigate the optical signatures of Odonata wings using hyperspectral imaging, laser profiling, ellipsometry, polarimetric modulation spectroscopy, and laser radar experiments. Based on results, we estimate the prospects for Odonata perception of WIPs to identify conspecifics in the spectral, spatial, intensity, polarization, angular, and temporal domains. We find six lines of evidence consistent with an ability to perceive WIPs. First, the wing membrane thickness of the studied Odonata is 2.3 μm, coinciding with the maximal thickness perceivable by the reported bandwidth. Second, flat wings imply that WIPs persist from whole wings, which can be seen at a distance. Third, WIPs constitute a major brightness in the visual environment only second after the solar disk. Fourth, WIPs exhibit high degree of polarization and polarization vision coincides with frontal narrow red bands in Odonata. Fifth, the angular light incidence on the Odonata composite eye provides all prerequisites for direct assessment of the refractive index which is associated with age. Sixth, WIPs from conspecifics in flight make a significant contribution even to the fundamental wingbeat frequency within the flicker fusion bandwidth of Odonata vision. We conclude that it is likely that WIPs can be perceived by the narrow red bands found in some Odonata species and propose future behavioral and electrophysiological tests of this hypothesis.
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| 3152. |
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| 3153. |
- Brännström, Pär A
(författare)
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Visual ecology of insect superposition eyes
- 1999
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the superposition compound eye each rhabdom (light sensitive unit) receives light through many ommatidial facets, while in the apposition compound eye every rhabdom receives light from a single facet. The superposition design increases photon capture, which is an advantage in dark environments. Despite their advantage in dim light, superposition eyes can sometimes be found in insects that live in brighter habitats. The aim of this thesis is to study visual adaptations in insects with superposition eyes. Animals with different lifestyles and activity patterns have been selected for this study. A more general theoretical analysis of the design of superposition eyes is also included in this thesis. The dorsal eyes of male mayflies (family Baetidae) are used only to detect females flying against the sky. Male mayflies that swarm in open habitats where a large portion of the sky is visible, have eyes with large fields of view but with a poor resolution. Other species swarm in forests, and have highly resolved tubular eyes with narrow fields of view that match the visible patches of sky. The elephant hawkmoth (Deilephila elpenor) has superposition eyes adapted for hovering in front of flowers while collecting nectar at night. The eye possesses smooth regional differences. The largest apertures, highest sensitivities and the largest binocular overlap are found in the anterio-ventral region of the eye with which they fixate flowers while feeding. They also have the poorest anatomical resolution in this region. The tiger beetle Cicindela hybrida has an eye that is optimised for visual hunting in a flat environment. It has an apposition eye during the day with a pronounced visual streak (horizontal acute zone) that forms a binocular acute zone at the front of the eye. The eye design matches their hunting behaviour and includes tilting of the head to fixate prey. The tropical tiger beetle Odontocheila chrysis, a close relative of Cicindela hybrida, lives in dark forest habitats and has superposition eyes both during the day and at night and no pronounced regional differences. The bright habitat of Cicindela has resulted in the evolution of apposition eyes, which permit pronounced regional differences, while in Odontocheila superposition eyes provide optimal vision in a dark environment but with limited possibilities for regional differences. Data from real eyes were compared to computer models to asses the basic principles and constraints in superposition eye design. We found several basic assumptions about superposition eye design to be incorrect: (1) the incident and exit angles in each optical unit are not equal for all angles, (2) the focal plane is not always located at half the radius of the whole eye, and (3) spherical aberration is not a major limitation to resolution in superposition eyes. The main conclusion of this analysis is that selection for design tolerance is an overlooked evolutionary force.
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| 3154. |
- Brännäs, Eva, et al.
(författare)
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Distinguishing Arctic charr with different stress coping styles by visual screening of spottiness - reliability and consistency over time
- 2016
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Ingår i: Journal of Zoology. - : Wiley. - 0952-8369 .- 1469-7998. ; 300, s. 213-220
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Tidskriftsartikel (refereegranskat)abstract
- The salmonid fish Arctic charr Salvelinus alpinus shows pronounced individual variation in skin colouration and density of carotenoid-based spots. It has earlier been shown that spot density is a heritable trait, and may be used as an indicator of stress coping style in Arctic charr. Individuals with few spots tend to be more aggressive and less responsive to stress (proactive) than those with many spots (reactive). Here, we evaluate the potential of grading individuals into proactive and reactive individuals by the density of light-coloured spots. This non-invasive method would be useful for selective breeding and to reduce within-treatment variation in biological research. Our aim was to investigate stability of spot density over time and to compare methods to estimate spottiness on Arctic charr, using photographs as well as live fish. The consistency of spot density was significant over a period of 8months, but with stronger correlations between September and December than between May and September. Also, repeatability of spot number was higher between the two last months than when including May. The spots were more stable on the left than the right side, thus, it is more reliable to estimate spottiness on the left side. There was a significant relationship between the ratio of spotted area (rsa) from automated image analysis and number of spots from visual counts. Both methods fitted well into a visual grading into three categories (few, medium and many spots). In another test, a large number of live fish were visually categorized according to spot density. The previous validation process, in combination with a significant family effect showed that large numbers of fish can be effectively graded.
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| 3155. |
- Bräutigam, Lars, et al.
(författare)
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Localized Expression of Urocortin Genes in the Developing Zebrafish rain
- 2010
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Ingår i: Journal of Comparative Neurology. - : Wiley. - 0021-9967 .- 1096-9861. ; 518:15, s. 2978-2995
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Tidskriftsartikel (refereegranskat)abstract
- The corticotropin-releasing hormone (CRH) family consists of four aralogous genes, CRH and urocortins (UCNs) 1, 2, and 3. In a previous tudy, we analyzed CRH in the teleost model organism zebrafish and its ranscript distribution in the embryonic brain. Here, we describe ull-length cDNAs encoding urotensin 1 (UTS1), the teleost UCN1 rtholog, and UCN3 of zebrafish. Major expression sites of uts1 in adult ebrafish are the caudal neurosecretory system and brain. By using T-PCR analysis, we show that uts1 mRNA is also present in ovary, aternally contributed to the embryo, and expressed throughout embryonic evelopment. Expression of ucn3 mRNA was detected in a range of adult issues and during developmental stages from 24 hours post fertilization nward. Analysis of spatial transcript distributions by whole-mount in itu hybridization revealed limited forebrain expression of uts1 and cn3 during early development. Small numbers of uts1-synthesizing eurons were found in subpallium, hypothalamus, and posterior iencephalon, whereas ucn3-positive cells were restricted to elencephalon and retina. The brainstem was the main site of uts1 and cn3 synthesis in the embryonic brain. uts1 Expression was confined to he midbrain tegmentum; distinct hindbrain cell groups, including locus oeruleus and Mauthner neurons; and the spinal cord. ucn3 Expression was ocalized to the optic tectum, serotonergic raphe, and distinct hombomeric cell clusters. The prominent expression of uts1 and ucn3 in rainstem is consistent with proposed roles of CRH-related peptides in tress-induced modulation of locomotor activity through monoaminergic rainstem neuromodulatory systems. J. Comp. Neurol. 518:2978-2995, 2010.
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| 3156. |
- Buddington, KK, et al.
(författare)
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A non-terminal surgical procedure for chronic collection of exocrine pancreatic secretions from unrestrained dogs (Canis familiaris)
- 2002
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Ingår i: Contemporary Topics in Laboratory Animal Science. - 1060-0558. ; 41:1, s. 31-37
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Tidskriftsartikel (refereegranskat)abstract
- The ability of dogs to adaptively modulate secretion by the exocrine pancreas to match changes in the amounts and sources of macronutrients is poorly understood. We evaluated the use of re-entrant pancreatic catheters as a non-terminal, temporary approach for the chronic collection of exocrine pancreatic secretion using unrestrained dogs fed diets differing in composition. Re-entrant catheters were surgically placed in the accessory pancreatic duct of two adult mongrel dogs. Secretions were collected for 40 days, during which the dogs were fed three diets with different amounts and sources of macronutrients. The volume of secretion was recorded, protein content was measured, and the activities of trypsin, chymotrypsin, amylase, and lipase were assayed. Inter-dog variation was detected for the volume of secretion (ml/h) but not for protein content (mg/ml) or activities (U/ml) of the enzymes. The volume and composition of the secretion differed among diets. The responses were delayed about 4 days, were transient, and did not coincide with the changes in diet composition. We found that the re-entrant catheters were suitable for studying the exocrine pancreatic secretion of dogs. Our findings were inconclusive about the influence of diet but suggested that adult dogs have a limited and nonspecific response of pancreatic secretion.
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| 3157. |
- Buddington, RK, et al.
(författare)
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Absorption of alpha-ketoglutarate by the gastrointestinal tract of pigs
- 2004
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Ingår i: Comparative Biochemistry and Physiology A. - : Elsevier BV. - 1531-4332. ; 138:2, s. 215-220
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Tidskriftsartikel (refereegranskat)abstract
- Only a small percentage of alpha-ketoglutarate (AKG) administered lumenally to pigs appears in the portal circulation. This has been attributed to mucosal metabolism, and possibly by limited absorption. Although transporters for di- and tricarboxylic acids, which includes the sodium-dependent transporter NaDC-1, have been detected in the small intestine, correlations with functional assays are lacking. Therefore, intact tissues from three regions of the small intestine, stomach, and colon of weaned pigs were used to measure rates of AKG absorption. Western analysis was used to detect NaDC-1 in the three regions of small intestine. Rates of AKG absorption were highest in the small intestine, lowest in the colon, and intermediate in the stomach. Immunoreactive NaDC-1 was detected in the small intestine and this coincided with a component of AKG absorption that was inhibited by AKG and succinate. In contrast, absorption of AKG was inhibitable by unlabeled AKG, but not succinate, in the stomach, and by neither in the colon. Feeding studies indicated that the amounts of AKG that might be included in practical diets for pigs would not (1) upregulate rates of AKG absorption or (2) exceed estimated capacities of the small intestine to absorb AKG. The present findings indicate that the efficacy of AKG as an alternative metabolic fuel for enterocytes to spare dietary amino acids is not limited by absorption.
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| 3158. |
- Buffington, Matthew L, et al.
(författare)
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A Revision of Zaeucoila Ashmead (Hymenoptera, Figitidae), Parasitoids of Agromyzidae (Diptera): New Species, Identity, Distribution, and Hosts
- 2017
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Ingår i: Proceedings of the Entomological Society of Washington. - : Entomological Society of Washington. - 0013-8797. ; 119:3, s. 317-397
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Tidskriftsartikel (refereegranskat)abstract
- The eucoiline genus Zaeucoila Ashmead is revised. Following a re- evaluation combining previously published phylogenetic data and new specimens, Agrostocynips D ́ıaz is synonymized with Zaeucoila. All species included in Zaeucoila are systematically treated, and now amounts to twelve, seven of which are described as new here: Zaeucoila bitiburculata new species, Z. fidalgoii new species, Z. infuscata new species, Z. johnsonii new species, Z. lignys new species, Z. normae new species, Z. patera new species. The following new combinations are proposed and species redescribed: Zaeucoila grenadensis (Ashmead), new combination; Z. robusta (Ashmead), new combination; Z. flavipes (Ashmead), new combination. Agrostocynips diastrophi (Ashmead), Agrostocynips clavatus D ́ıaz, and Agrostocynips enneatoma (D ́ıaz) are new synonyms of Zaeucoila robusta. Zaeucoila incompleta (Kieffer), Z. triangu- lifera Kieffer, and Z. unicarinata Ashmead are redescribed. Zaeucoila is an unusual genus of Zaeucoilini in its wide distribution area: it can be found from southern Argentina well into the eastern United States and southern Canada; no other zaeucoiline genus shows such a pattern. Host records and geographic data for Zaeucoila are brought up to date, as well as a key to species. Zeucoila are primary parasitoids of Agromyzidae, including Liriomyza trifolii and other species that are notable economic pests of agriculture. Tropideucoila fulvonotata (Kieffer) is transferred to Marthiella (new combination).
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| 3159. |
- Buffington, Matthew L, et al.
(författare)
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Redescription of Ganaspis brasiliensis (Ihering, 1905), new combiantion, (Hymenoptera: Figitidae) a natural enemy of the invasive Drosophila suzukii (Matsumura, 1931) (Diptera: Drosophilidae)
- 2016
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Ingår i: Proceedings of the Entomological Society of Washington. - : Entomological Society of Washington. - 0013-8797. ; 118:1, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- The new combination of Ganaspis brasiliensis (Ihering, 1905) is proposed, and the species is redescribed from historical specimens taken in the Neotropical Region as well as more recent specimens reared from Drosophila suzukii Matsumura, 1931 in South Korea. Drosophila suzukii, otherwise known as the spotted-wing Drosophila, is a major pest of soft fruits the world over, and the search for effective natural enemies of this fly are ongoing. Though not parasitoids of D. suzukii, we also propose the following new combinations: Dieucoila brasiliensis (Kieffer, 1909), new combination, and Dieucoila brasiliana (Weld, 1952), new combination. After summarizing all known species of Eucoilinae with the specific epithet ‘brasiliensis’, we encourage future researchers to avoid this name in order prevent nomenclatural confusion.
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| 3160. |
- Buffington, Matthew L, et al.
(författare)
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The description of Garudella Buffington and Forshage, new genus (Hymenoptera: Figitidae: Eucoilinae)
- 2014
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Ingår i: Proceedings of the Entomological Society of Washington. - : Entomological Society of Washington. - 0013-8797. ; 116:3, s. 225-242
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Tidskriftsartikel (refereegranskat)abstract
- Garudella, a remarkable new genus of eucoiline wasp is described from Thailand, Laos, and the Republic of Congo. Four new species of Garudella are described as well: G. acothonaspis, G. afrotropica, G. algo, and G. alicae. Several autapomorphies distinguish this genus from other eucoiline genera: a distinctly protracted and broadened pronotal plate; a massive, posteriorly protruding prop- odeum; reduced posterior rim of metapleuron; reduced scutellar foveae and lack of lateral bar “windows”; and a generally reduced scutellar plate. In addition, the posterior of the head has a distinctly curved occipital impression, resulting in the cuticle surrounding the foramen magnum to be extruded into a neck-like process. The biology of Garudella is unknown, but based on phylogenetic inference from morphology, the presumed host could be a cyclorrhaphous Diptera in a saprophagous environment.
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