| 1. |
- Hollander, Johan, et al.
(författare)
-
Genital divergence in sympatric sister snails.
- 2013
-
Ingår i: Journal of evolutionary biology. - : Wiley. - 1420-9101 .- 1010-061X. ; 26:1, s. 210-215
-
Tidskriftsartikel (refereegranskat)abstract
- A pattern of greater divergence in mating traits between sister-species pairs with overlapping ranges than between allopatric species pairs is expected if reinforcement commonly contributes to speciation. Few large-scale comparative analyses have addressed this prediction, especially for genital form. Here, we show that penial morphology follows the predicted pattern in 40 robustly identified sister-species pairs in the marine gastropod subfamily Littorininae. Further work is needed to exclude other processes that may contribute to genital divergence between sympatric species, but the clear pattern we observe strongly suggests a role for genital form in reproductive isolation in this large clade.
|
|
| 2. |
- Lawal, Najeem, 1974-
(författare)
-
Memory Synthesis for FPGA Implementation of Real-Time Video Processing Systems
- 2006
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, both a method and a tool to enable efficient memory synthesis for real-time video processing systems on field programmable logic array are presented. In real-time video processing system (RTVPS), a set of operations are repetitively performed on every image frame in a video stream. These operations are usually computationally intensive and, depending on the video resolution, can also be very data transfer dominated. These operations, which often require data from several consecutive frames and many rows of data within each frame, must be performed accurately and under real-time constraints as the results greatly affect the accuracy of application. Application domains of these systems include object recognition, object tracking and surveillance. Developments in field programmable gate array (FPGA) have been the motivation for choosing them as the platform for implementing RTVPS. Essential logic resources required in RTVPS operation are currently available optimized and embedded in modern FPGAs. One such resource is the embedded memory used for data buffering during real-time video processing. Each data buffer corresponds to a row of pixels in a video frame, which is allocated using a synthesis tool that performs the mapping of buffers to embedded memories. This approach has been investigated and proven to be inefficient. An efficient alternative employing resource sharing and allocation width pipelining will be discussed in this thesis. A method for the optimal use of these embedded memories and, additionally, a tool supporting automatic generation of hardware descriptions language (HDL) codes for the synthesis of the memories according to the developed method are the main focus of this thesis. This method consists of the memory architecture, allocation and addressing. The central objective of this method is the optimal use of embedded memories in the process of buffering data on-chip for an RVTPS operation. The developed software tool is an environment for generating HDL codes implementing the memory sub-components. The tool integrates with the Interface and Memory Modelling (IMEM) tools in such a way that the IMEM’s output - the memory requirements of a RTVPS - is imported and processed in order to generate the HDL codes. IMEM is based on the philosophy that the memory requirements of an RTVPS can be modelled and synthesized separately from the development of the core RTVPS algorithm thus freeing the designer to focus on the development of the algorithm while relying on IMEM for the implementation of memory sub-components.
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
- Agius, Maria, 1981-
(författare)
-
Åberopande av nödläge inom folkrätten
- 2008
-
Ingår i: Svensk Juristtidning. - Stockholm : Svensk juristtidning. - 0039-6591. ; , s. 133-145
-
Tidskriftsartikel (refereegranskat)abstract
- Den moderna folkrätten har ett utstuderat system för ansvarsutkrävande när en stat svikit de plikter man åtagit sig i förhållande till andra stater. Inom statsansvarsrätten finns dock ett antal ansvarsfrihetsgrunder. En av de mer kontroversiella är den s.k. nödlägesinvändningen. Nödläge har kommit upp i ett antal intressanta internationella rättsfall under de senaste decennierna, bl.a. rörande åtgärder för att skydda miljön, humanitära interventioner och internationell terroristbekämpning. Trots att det fortfarande är ett kontroversiellt institut är det tydligt att stater under vissa omständigheter undgår ansvar för folkrättsbrott om de handlat av nöd. Frågan som diskuteras här är huruvida möjligheten att avvika från internationella åtaganden med hänvisning till ett nödläge kan vara skadlig för den internationella rättens utveckling. Staters tillit till internationella rättsregimer kan skadas och deras benägenhet att reglera sina mellanhavanden i traktatsform minska. Nödlägesinstitutet är dock starkt kringskuret i internationell praxis. Vidare medför det inte att beteendet är att anse som i sig lagligt. Nödläge kan därför i vissa avseenden utan större fara för den internationella rättsordningen utgöra en nödvändig säkerhetsventil.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
- Barrantes, Alejandro, et al.
(författare)
-
Influence of pH on the build-up of poly-L-lysine/heparin multilayers
- 2012
-
Ingår i: Journal of Colloid and Interface Science. - : Elsevier. - 0021-9797 .- 1095-7103. ; 388:1, s. 191-200
-
Tidskriftsartikel (refereegranskat)abstract
- The effect of pH on the build-up-of polyelectrolyte multilayers, PEMs, composed by poly-L-lysine and heparin onto two different substrates, silica and gold, has been studied by means of ellispmetry and quartz crystal microbalance with dissipation, QCM-D. Ellipsometry results indicate that the dry mass grows exponentially with the number of layers, and that this amount is larger as the pH values are raised. From QCM-D data the viscoelastic properties of the multilayered structure have been obtained. These data reflect that PEMs become more viscoelastic as the pH values are increased for silica substrates, while for gold the highest viscoelastic behavior is obtained at neutral pH and the elastic behavior becomes dominant as the pH is further increased or decreased. By combining these two surface techniques it has been also possible to determine the solvent content in the multilayers and reach a deeper understanding of the internal structure.
|
|
| 9. |
- Barrantes, Alejandro, et al.
(författare)
-
Poly-L-lysine/heparin multilayer coatings prevent blood protein adsorption
- 2017
-
Ingår i: Journal of Colloid and Interface Science. - : Elsevier. - 0021-9797 .- 1095-7103. ; 485, s. 288-295
-
Tidskriftsartikel (refereegranskat)abstract
- The adsorption of blood proteins, serum albumin (BSA), immunoglobulin G (IgG) and fibrinogen (FGN), onto model SiO2 planar surfaces coated with poly-L-lysine/heparin multilayers (PLL/HEP) has been investigated by means of ellipsometry and quartz crystal microbalance with dissipation. Aiming at the development of low fouling coatings, this study has been focused on the effects that the number of layers and the type of polyelectrolyte present on the topmost layer have on the adsorption of these proteins. The three proteins interact with PLL-ended coatings whereas HEP-ended coatings prevent the adsorption of both BSA and IgG and induce a decrease in the adsorbed amount of FGN, down to 0.4 mg/m(2) for three bilayers, as the number of PLL/HEP bilayers increases. These results suggest that heparin-ended multilayers prevent protein adsorption, which is an indicative of good blood compatibility. As a consequence we propose that PLL/HEP coatings could be used for the development of vascular medical devices. (C) 2016 Elsevier Inc. All rights reserved.
|
|
| 10. |
- Barras, Christine, et al.
(författare)
-
Experimental calibration of manganese incorporation in foraminiferal calcite
- 2018
-
Ingår i: Geochimica et Cosmochimica Acta. - : Elsevier BV. - 0016-7037. ; 237, s. 49-64
-
Tidskriftsartikel (refereegranskat)abstract
- In the context of recent climate change and increased anthropogenic activities in coastal areas, which both may have a negative impact on dissolved oxygen concentration, there is an increased interest to better understand the mechanisms and evolution leading to hypoxia in marine environments. The development of well calibrated proxies is crucial to obtain reliable environmental reconstructions of past oxygen content and of historical development of hypoxia. Manganese is a redox element of interest for this purpose because manganese oxides are reduced to soluble Mn2+ in oxygen-depleted conditions, which can be incorporated in biogenic calcite. The Mn/Ca ratio in benthic foraminiferal calcite is therefore a promising proxy to reconstruct past oxygen variations. In this study, we calibrate this proxy by measuring (with Laser Ablation ICP-MS) the Mn/Ca ratio of benthic foraminifera calcified under controlled conditions in laboratory experiments. Two benthic foraminiferal species (Ammonia tepida and Bulimina marginata) calcified in 4 different dissolved manganese concentrations (from 2.4 to 595 µmol L−1) corresponding to in situ Mn concentrations encountered in bottom and/or pore waters in low oxygen marine environments. There is a statistically significant positive linear correlation (R2 > 0.9) between Mn/Cacalcite and Mn/Caseawater. However, the two species show different partitioning coefficients (DMn of 0.086 and 0.621, for A. tepida and B. marginata, respectively), although they calcified in exactly the same stable conditions. These results highlight a strong species specific effect on Mn incorporation, which is probably due to different biological controls during biomineralisation processes. There is also ontogenetic variability (determined through a comparison of successive chambers) that is different between the two species and also varies as a function of the dissolved Mn concentration. A conceptual model is proposed to explain these data.
|
|
