| 1. |
- Karlström, Gunnar, et al.
(author)
-
MOLCAS : a program package for computational chemistry
- 2003
-
In: Computational materials science. - 0927-0256 .- 1879-0801. ; 28:2, s. 222-239
-
Journal article (peer-reviewed)abstract
- The program system MOLCAS is a package for calculations of electronic and structural properties of molecular systems in gas, liquid, or solid phase. It contains a number of modern quantum chemical methods for studies of the electronic structure in ground and excited electronic states. A macromolecular environment can be modeled by a combination of quantum chemistry and molecular mechanics. It is further possible to describe a crystalline material using model potentials. Solvent effects can be treated using continuum models or by combining quantum chemical calculations with molecular dynamics or Monte-Carlo simulations. MOLCAS is especially adapted to treat systems with a complex electronic structure, where the simplest quantum chemical models do not work. These features together with the inclusion of relativistic effects makes it possible to treat with good accuracy systems including atoms from the entire periodic system. MOLCAS has effective methods for geometry optimization of equilibria, transition states, conical intersections, etc. This facilitates studies of excited state energy surfaces, spectroscopy, and photochemical processes.
|
|
| 2. |
- Arner, Anders, et al.
(author)
-
Calcium transients and the effect of a photolytically released calcium chelator during electrically induced contractions in rabbit rectococcygeus smooth muscle
- 1998
-
In: Biophysical Journal. - 1542-0086 .- 0006-3495. ; 75:4, s. 1895-1903
-
Journal article (peer-reviewed)abstract
- Intracellular Ca2+ was determined with the fura-2 technique during electrically induced contractions in the rabbit rectococcygeus smooth muscle at 22 degreesC. The muscles were electrically activated to give short, reproducible contractions. Intracellular [Ca2+] increased during activation; the increase in [Ca2+] preceded force development by approximately 2 s. After cessation of stimulation Ca2+ fell, preceding the fall in force by approximately 4 s. The fluorescence properties of fura-2 were determined with time-resolved spectroscopy using synchrotron light at the MAX-storage ring, Lund, Sweden. The fluorescence decay of free fura-2 was best described by two exponential decays (time constants approximately 0.5 and 1.5 ns) at low Ca2+ (pCa 9). At high Ca2+ (pCa 4.5), fluorescence decay became slower and could be fitted by one exponential decay (1.9 ns). Time-resolved anisotropy of free fura-2 was characteristic of free rotational motion (correlation time 0.3 ns). Motion of fura-2 could be markedly inhibited by high concentrations of creatine kinase. Time-resolved spectroscopy measurements of muscle fibers loaded with fura-2 showed that the fluorescence lifetime of the probe was longer, suggesting an influence of the chemical environment. Anisotropy measurements revealed, however, that the probe was mobile in the cells. The Ca2+-dependence of contraction and relaxation was studied using a photolabile calcium chelator, diazo-2, which could be loaded into the muscle cells in a similar manner as fura-2. Photolysis of diazo-2 leads to an increase in its Ca2+-affinity and a fall in free Ca2+. When muscles that had been loaded with diazo-2 were illuminated with UV light flashes during the rising phase of contraction, the rate of contraction became slower, suggesting a close relation between intracellular Ca2+ and the cross-bridge interaction. In contrast, photolysis during relaxation did not influence the rate of force decay, suggesting that relaxation of these contractions is not determined by the rate of Ca2+ removal or due to an increased Ca2+ sensitivity, but instead is limited by other processes such as deactivation by dephosphorylation or detachment of tension-bearing cross-bridges, possibly regulated by thin filament systems.
|
|
| 3. |
- Fritz, Örjan, et al.
(author)
-
Bjurkärr – en småländsk bokskog med unika lavar och svampar.
- 2014
-
In: Svensk Botanisk Tidskrift. - 0039-646X. ; 108:3–4, s. 2-18
-
Journal article (peer-reviewed)abstract
- The old beech forest (250–300 yr) at Bjurkärr (core area 30 ha) in the province of Småland, S Sweden, was surveyed for epiphytic lichens of conservation concern in 1993–94. Several rare red-listed lichens were recorded, many with large populations. In 2011 the most endangered lichens were resurveyed due to the incorporation of Bjurkärr in the forthcoming national park of Lake Åsnen. Most species of the 1993–94 survey were rediscovered, whereas some apparently had vanished as a result of substrate decomposition. In addition, ten more red-listed lichens were recorded in 2011, e.g., Arthonia arthonioides and Collema fragrans. We also recorded Biatora ligni-mollis, not previously reported from Sweden. In all, 39 red-listed lichens are currently known from the area. Few areas in Sweden host such a large number of red-listed epiphytic lichens. In addition, the wood-inhabiting fungi on beech logs and snags were surveyed in 2011. The content of dead wood was high. A large number of red-listed or otherwise interesting wood-inhabiting fungi were recorded, e.g., Hericium erinaceus. Eleven fungal indicator species for valuable beech forests in Europe were recorded, the highest number for any Swedish beech forest. Factors explaining the high number of species of conservation concern include the long continuity of old, often slow-growing and damaged trees, the favourable geographical position in south Sweden, the suitable microclimate caused by the large neighboring lake and the exemption from modern forestry.
|
|
| 4. |
|
|
| 5. |
- Olsson, Ola, et al.
(author)
-
Variability of patch type preferences in relation to resource availability and breeding success in a bird
- 2001
-
In: Oecologia. - : Springer Science and Business Media LLC. - 1432-1939 .- 0029-8549. ; 127:3, s. 435-443
-
Journal article (peer-reviewed)abstract
- This paper investigates how variability in partial foraging preferences for patch types can be used as a behavioral indicator of the energetic value of that patch type, and of overall food availability in the territory. The species studied was the lesser spotted woodpecker (Dendrocopos minor) and the patch types it uses are four groups of tree species (oak Quercus robur, birch Betula pendula, B. pubescens, alder Alnus glutinosa, and lime Tilia cordata), in which it feeds upon wood-living insect larvae. We partition the variation in foraging preferences into three scales. Firstly, within territories, the foraging preference for a tree species group was positively related to the prey density in that species group. That is, the preferences measure the patch types' energetic profit-abilities. This result should be general in cases like the present, where the costs of using different alternatives do not differ substantially. It may therefore be the preferred behavioral indicator in determining the relative benefits associated with different alternatives. Secondly, between the seven years of study, much of the variation in tree species group preferences was attributable to measured fluctuations in the density of one important prey species (Argyresthia goedarthella, Argyresthidae, Lepidoptera), which occurred in some years on birch, in others on alder, and in one year was virtually absent. Thus, in concordance with the previous result, the values of these tree species groups fluctuated between years according to prey density. Thirdly, between territories, we found that the preference for one tree species, lime, was higher in areas where it was more abundant. We attribute this to the fact that the density (per patch) of at least one important prey species (Stenostola dubia, Cerambycidae, Coleoptera) on lime increased with the abundance of its host tree species in the territory. That is, the overall food availability was higher in territories where lime was more common. Hence, the preference for lime estimates overall food availability. This conclusion is strengthened by two additional facts: the preference for lime correlates positively (1) with the average giving-up density of food, which has previously been shown to estimate overall food availability in the territories, and (2) with reproductive success, at least during the early stages of reproduction.
|
|
| 6. |
- Sjuve, Rolf, et al.
(author)
-
Increased expression of non-muscle myosin heavy chain-B in connective tissue cells of hypertrophic rat urinary bladder
- 2001
-
In: Cell and Tissue Research. - : Springer Science and Business Media LLC. - 1432-0878 .- 0302-766X. ; 304:2, s. 271-278
-
Journal article (peer-reviewed)abstract
- Expression of the non-muscle myosin heavy chain-B (NM-MHC-B, also denoted as the embryonic smooth muscle myosin heavy chain, SMemb) was examined in rat urinary bladder during growth in response to a partial urinary outflow obstruction. Following obstruction, the weight of the urinary bladder increased more than five-fold within 10 days. Immunohistochemistry with a polyclonal antiserum against the C-terminal sequence of NM-MHC-B revealed very few NM-MHC-B immunoreactive cells in the control urinary bladders. In hypertrophic bladders, the number of NM-MHC-B immunoreactive cells markedly increased. The majority of such cells were found in the interstitium surrounding smooth muscle bundles and also in the subserosal and submucosal layers. Western blot analysis showed that the NM-MHC-B expression was transient; the content of NM-MHC-B immunoreactive material had doubled 10 days after obstruction and then declined towards the control level after 6 weeks. Immunohistochemistry revealed co-localization of NM-MHC-B and vimentin within the same cells. NM-MHC-B did not co-localize with smooth muscle actin, suggesting that the source of NM-MHC-B is not a de-differentiated smooth muscle cell or myofibroblast but a non-muscle cell possibly reacting to tissue distension or stress. The NM-MHC-B-positive cells could have a role in the production of extracellular matrix and growth factors or be involved in modulation of spontaneous contractile activity.
|
|
