| 1. |
- Anton, Sylvia, et al.
(författare)
-
Developmental changes in the structure and function of the central olfactory system in gregarious and solitary desert locusts
- 2002
-
Ingår i: Microscopy Research and Technique. - : Wiley. - 1059-910X .- 1097-0029. ; 56:4, s. 281-291
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Desert locusts are guided by olfactory cues in different behavioural contexts. In order to understand the basis for the variable olfactory guided behaviour displayed by different developmental stages and by solitary and gregarious locusts, we investigated their central olfactory system with neuroanatomical and neurophysiological methods. The primary olfactory centre of the brain, the antennal lobe (AL), increases in size during development due to an increased number and size of glomeruli. These glomeruli are innervated by a constant number of projection neurons that display increased dendritic arborizations during the development of the locust. The anatomical parameters do not differ between gregarious and solitary locusts, In parallel with the observed neuroanatomical changes, neurophysiological changes in response spectra and response specificity of AL neurons were found. During development, the percentage of neurons responding specifically to aggregation pheromone components decreases, whereas an increase in both pheromone-generalists and plant-pheromone generalist neurons is observed. The percentage of neurons responding to green leaf volatiles, however, remains constant. A decrease in the number of nymph blend-specific neurons was also observed. Our data show that anatomical and physiological properties of the AL and its neurons to a large extent reflect the changes in olfactory guided behaviour during development and between phases. The majority of our results are also in accordance with findings that the number of olfactory receptor neurons increases during development, resulting in increasing convergence on AL neurons.
|
|
| 2. |
|
|
| 3. |
- Henrik Ullsten, N., et al.
(författare)
-
Extruded high quality materials from wheat gluten
- 2010
-
Ingår i: Polymers from Renewable Resources. - : SAGE Publications. - 2041-2479 .- 2045-1377. ; 1:4, s. 173-186
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, we report that the addition of ammonium hydroxide (NH4OH)significantly enhance the properties of extruded WG-based materials. The grainystructure disappeared and the extrudate became more uniform and glossy. Thebarrier properties improved and the oxygen permeability at dry conditions was aslow as that for a number of petroleum-based plastics (poly(ethylene terephthalateand polyamide 66). The protein structure in this material was extensivelyaggregated, which improved the strength and stiffness; there was a ca 4-foldincrease in maximum stress compared to that of the NH4OH-free samples. Theprotein solubility decreased to almost zero. Even a severe sonication treatmentin sodium dodecyl sulphate (SDS) did not increase the solubility. The only typeof protein that it was possible to extract was the 'thermo-resistant' w-gliadinslacking disulfide-bonds. Our result provides new opportunities to develop a WGbasedfilm extrudate for potential use as e.g. a renewable barrier layer in foodand non-food laminate packagings.
|
|
| 4. |
- Ignell, Rickard, et al.
(författare)
-
Presynaptic peptidergic modulation of olfactory receptor neurons in Drosophila.
- 2009
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 106:31, s. 13070-13075
-
Tidskriftsartikel (refereegranskat)abstract
- The role of classical neurotransmitters in the transfer and processing of olfactory information is well established in many organisms. Neuropeptide action, however, is largely unexplored in any peripheral olfactory system. A subpopulation of local interneurons (LNs) in the Drosophila antannal lobe is peptidergic, expressing Drosophila tachykinins (DTKs). We show here that olfactory receptor neurons (ORNs) express the DTK receptor (DTKR). Using two-photon microscopy, we found that DTK applied to the antennal lobe suppresses presynaptic calcium and synaptic transmission in the ORNs. Furthermore, reduction of DTKR expression in ORNs by targeted RNA interference eliminates presynaptic suppression and alters olfactory behaviors. We detect opposite behavioral phenotypes after reduction and over expression of DTKR in ORNs. Our findings suggest a presynaptic inhibitory feedback to ORNs from peptidergic LNs in the antennal lobe.
|
|
| 5. |
- Kuktaite, Ramune, et al.
(författare)
-
Structure and Morphology of Wheat Gluten Films : From Polymeric Protein Aggregates toward Superstructure Arrangements
- 2011
-
Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 12:5, s. 1438-1448
-
Tidskriftsartikel (refereegranskat)abstract
- Evaluation of structure and morphology of extruded wheat gluten (WG) films showed WG protein assemblies elucidated on a range of length scales from nano (4.4 angstrom and 9 to 10 angstrom, up to 70 angstrom) to micro (10 mu m). The presence of NaOH in WG films induced a tetragonal structure with unit cell parameters, a = 51.85 angstrom and c = 40.65 angstrom, whereas NH4OH resulted in a bidimensional hexagonal close-packed (HCP) structure with a lattice parameter of 70 angstrom. In the WG films with NH4OH, a highly polymerized protein pattern with intimately mixed glutenins and gliadins bounded through SH/SS interchange reactions was found. A large content of beta-sheet structures was also found in these films, and the film structure was oriented in the extrusion direction. In conclusion, this study highlights complexities of the supramolecular structures and conformations of wheat gluten polymeric proteins in biofilms not previously reported for biobased materials.
|
|
| 6. |
- Mode, R. Ignell, et al.
(författare)
-
Fathers' perception of information received during their infants' stay at a neonatal intensive care unit
- 2014
-
Ingår i: Sexual & Reproductive HealthCare. - : Elsevier BV. - 1877-5756 .- 1877-5764. ; 5:3, s. 131-136
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: To explore fathers' perception of information received during their infants' care at a neonatal intensive care unit (NICU). Methods: An inductive, qualitative and descriptive study. Eight fathers in two units were interviewed. The infants' gestational age at birth ranged between 23 and 36 weeks. Data were collected through semi-structured, individual interviews and were analyzed by qualitative content analysis. Results: Three categories were identified: perception of information, perception of the source of information, and circumstances influencing the perception of information. Information had an important impact; comprehensible and adequate information increased the fathers' knowledge, which generated a sense of control. Early information about the infant's care was particularly important and positively affected father and infant bonding. Conclusion and practical implications: Ensuring a high quality of information is an important task for NICU staff. Fathers' perception of the quality of information depended on the contents of the information and how it was conveyed. Comprehensible information at the onset of the infant's hospital stay increased the fathers' sense of security, and made them feel in control. It is important that the staff strive to identify what information the father requires, and prevent situations when fathers feel uncertainty about what the staff expect from them.
|
|
| 7. |
|
|
| 8. |
- Winther, Åsa M E, et al.
(författare)
-
Peptidergic signaling in the antennal lobe modulates olfaction
- 2007
-
Ingår i: 20th European Drosophila Research Coference.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The dtk gene in Drosophila encodes five different neuropeptides designated Drosophila tachykinins (DTK 1-5) that are expressed in about 100 neurons in the brain. Two tachykinin receptors (DTKR and NKD) have been identified in Drosophila. Specific neurons of the antennal lobe (AL), the primary center for olfactory processing in the Drosophila brain, express DTKs and the receptor DTKR. The DTKs are colocalized with the inhibitory transmitter GABA in many of the local interneurons (LNs) of the AL. We have investigated the roles of DTKs and DTKR in olfactory behavior by interfering with DTK signaling. By employing the Gal4/UAS system we have directed overexpression or knock-down (using RNAi) of peptides or receptor to different neuron types of the AL. Olfactory behavior was tested in a trap-assay based on a choice of odorant or control. We tested flies with DTK deficiency in two different partly overlapping populations of LNs. We also tested flies that are virtually DTK null (driving the RNAi construct with the pan-neural elav-Gal4). DTK deficient flies were less attracted to some of the odors tested. To study the role of the DTKR we used Gal4 lines that drive expression in olfactory receptor neurons (ORNs), LNs and in projection neurons to overexpress (OE) or down-regulate the receptor. DTKR-OE in the ORNs resulted in flies more repelled (or less attracted) to some of the odors tested. DTKR-OE in a subpopulation of the LNs produced flies with the same behavioral phenotype. Flies with DTKR deficiency in the ORNs and LNs were more attracted to odors. Our results suggest that DTKs and DTKR are involved in the modulation of the response to odors at the levels of ORNs and LNs, possibly by modulating the inhibitory activity of GABA.
|
|
