SOLWEIG 1.0 – Modelling spatial variations of 3D radiant fluxes and mean radiant temperature in complex urban settings

The mean radiant temperature, T_mrt, which sums up all shortwave and longwave radiation fluxes (both direct and reflected) to which the human body is exposed is one of the key meteorological parameters governing human energy balance and the thermal comfort of man. In this paper, a new radiation model (SOLWEIG 1.0), which simulates spatial variations of 3D radiation fluxes and T_mrt in complex urban settings, is presented. The T_mrt is derived by modelling shortwave and longwave radiation fluxes in six directions (upward, downward and from the four cardinal points) and angular factors. The model requires a limited number of inputs, such as direct, diffuse and global shortwave radiation, air temperature, relative humidity, urban geometry and geographical information (latitude, longitude and elevation). The model was evaluated using 7 days of integral radiation measurements at two sites with different building geometries – a large square and a small courtyard in Göteborg, Sweden (57°N) – across different seasons and in various weather conditions. The evaluation reveals good agreement between modelled and measured values of T_mrt, with an overall good correspondence of R ²?=?0.94, (p?相似文献   

High occurrence of red-listed bryophytes and lichens in mature managed forests in boreal Sweden

Successful biodiversity conservation needs to be based on reliable data regarding the distribution and abundance of species. Red Lists summarize the status of rare and declining species. Here we present the first detailed survey (10 m × 10 m resolution) of nationally red-listed bryophytes and lichens at stand level in boreal forests. 30 managed forest production stands in boreal Sweden, soon to be harvested, were surveyed in detail regarding red-listed bryophytes and lichens. On the 180 ha totally investigated, 33 red-listed species were found, representing 35% of all forest red-listed bryophytes and lichens so far recorded from this part of Sweden. The mean number of red-listed species per stand was 10 and varied between 5 and 16. Excluding three species which were so common that, given the time-limit, it was not possible to record all of their occurrences, there were on average 6 number of observations ha⁻¹. The presence and density exceed those earlier found in ‘key habitats’, defined as hot-spots for red-listed species. Almost all observations were made on trees, with 48% on living trees and 52% on dead. Altitude, area and stem volume explained 67% of the red-list species density. The results highlight the importance of unprotected areas for rare and declining species and point to a hitherto unacknowledged high biodiversity value of mature managed boreal forest stands, shaped by a less intense forestry than today's. It also raises questions regarding the use of red-listed species to identify areas of importance to biodiversity. Objective and systematic surveys of red-listed species in the forest landscape, including younger stands, are urgent.Der erfolgreiche Schutz der Biodiversität muss auf verlässlichen Daten über die Verbreitung und Abundanz der Arten basieren. Rote Listen fassen den Status seltener und abnehmender Arten zusammen. Hier präsentieren wir die erste detaillierte Erfassung (10 m × 10 m Auflösung) von Bryophyten und Flechten der nationalen Rote Liste auf Bestandsniveau in borealen Wäldern. Im borealen Schweden wurden in 30 bewirtschafteten Produktionswälder, die bald geerntet werden sollen, die Bryophyten und Flechten der Roten Liste im Detail erfasst. Auf den insgesamt untersuchten 180 ha wurden 33 Arten der Roten Liste gefunden, die 35% aller Wald-Bryophyten und-Flechten der Roten Liste repräsentieren, die bisher in diesem Teil Schwedens erfasst wurden. Die mittlere Anzahl derRote-Liste-Arten pro Bestand war 10 und variierte zwischen 5 und 16. Unter Ausschluss von drei Arten, die so gewöhnlich waren, dass es bei dem gegebenen Zeitlimit nicht möglich war alle ihre Vorkommen zu erfassen, gab es im Durchschnitt 6 Beobachtungen ha⁻¹. Vorkommen und Dichten übertrafen die früher in “Schlüsselhabitaten” gefundenen, die als ‘hot spots’ bezeichnet werden. Fast alle Beobachtungen wurden auf Bäumen gemacht, mit 48% auf lebenden und 52% auf toten Bäumen. Die Höhe, das Gebiet und das Stammvolumen erklärten 67% der Dichte der Rote-Liste-Arten. Die Ergebnisse heben die Wichtigkeit nicht-geschützter Gebiete für seltene und abnehmende Arten hervor und weisen auf einen bisher nicht wahrgenommenen hohen Biodiversitätswert von alten bewirtschafteten borealen Waldbeständen hin, die von einer weniger intensiven Forstwirtschaft als der heutigen geformt wurden. Es stellen sich ebenso Fragen, die die Verwendung der Rote-Liste-Arten betreffen, um für die Biodiversität wichtige Gebiete zu identifizieren. Objektive und systematische Erfassungen der Rote-Liste-Arten in Waldlandschaften inklusive der jüngeren Bestände sind dringend.     

Large-scale movement within the voltage-sensor paddle of a potassium channel-support for a helical-screw motion

The size of the movement and the molecular identity of the moving parts of the voltage sensor of a voltage-gated ion channel are debated. In the helical-screw model, the positively charged fourth transmembrane segment S4 slides and rotates along negative counter charges in S2 and S3, while in the paddle model, S4 carries the extracellular part of S3 (S3b) as a cargo. Here, we show that S4 slides 16-26 A along S3b. We introduced pairs of cysteines in S4 and S3b of the Shaker K channel to make disulfide bonds. Residue 325 in S3b makes close and state-dependent contacts with a long stretch of residues in S4. A disulfide bond between 325 and 360 was formed in the closed state, while a bond between 325 and 366 was formed in the open state. These data are not compatible with the voltage-sensor paddle model, but support the helical-screw model.     

Morphology and morphometry of the reproductive organs in prepubertal and postpubertal male pigs exposed to di(2-ethylhexyl) phthalate before puberty: Precocious development of bulbourethral glands

In a split-litter design experiment, male piglets were exposed orally three times weekly to 300mg/kg of di(2-ethylhexyl) phthalate (DEHP) or placebo between three and seven weeks of age. The effects on the reproductive organs were examined immediately after the exposure at seven weeks of age in one sub-group, and postpuberally at nine months of age in the other. Morphological features of testes were unaffected at either age group; there were no differences (p>0.05) between the treatments in number of Sertoli cells (as identified by immunostaining with GATA-4 antibodies), percent area of Leydig cells (as detected by 3beta-hydroxysteroid dehydrogenase histochemistry), or incidence of germinal epithelial lesions (histopathology of H&E-stained (hematoxylin and eosin) sections). Three of the seven DEHP-treated animals in seven-week-old group had bulbourethral glands at a stage of maturation far more advanced than that of controls. While there were no obvious differences in the cellular composition between the treatment groups in nine-month-old animals, the bulbourethral glands were heavier (p<0.05) in DEHP-treated boars. Collectively, these features indicate that adolescent exposure to DEHP induces precocious maturity of bulbourethral glands in pigs with persistent effects lasting into adulthood.     

The mitochondrial external NADPH dehydrogenase modulates the leaf NADPH/NADP+ ratio in transgenic Nicotiana sylvestris

Plant mitochondria contain alternative external NAD(P)H dehydrogenases,which oxidize cytosolic NADH or NADPH and reduce ubiquinonewithout inherent linkage to proton pumping and ATP production.In potato, St-NDB1 is an external Ca²⁺-dependent NADPH dehydrogenase.The physiological function of this enzyme was investigated inhomozygous Nicotiana sylvestris lines overexpressing St-ndb1and co-suppressing St-ndb1 and an N. sylvestris ndb1. In leafmitochondria isolated from the overexpressor lines, higher activityof alternative oxidase (AOX) was detected. However, the AOXinduction was substantially weaker than in the complex I-deficientCMSII mutant, previously shown to contain elevated amounts ofNAD(P)H dehydrogenases and AOX. An aox1b and an aox2 gene wereup-regulated in CMSII, but only aox1b showed a response, albeitsmaller, in the transgenic lines, indicating differences inAOX activation between the genotypes. As in CMSII, the increaseof AOX in the overexpressing lines was not due to a generaloxidative stress. The lines overexpressing St-ndb1 had consistentlylowered leaf NADPH/NADP⁺ ratios in the light and variably decreasedlevels in darkness, but unchanged NADH/NAD⁺ ratios. CMSII insteadhad similar NADPH/NADP⁺ and lower NADH/NAD⁺ ratios than thewild type. These results demonstrate that St-NDB1 is able tomodulate the cellular balance of NADPH and NADP⁺ at least inthe day and that reduction of NADP(H) and NAD(H) is independentlycontrolled. Similar growth rates, chloroplast malate dehydrogenaseactivation and xanthophyll ratios indicate that the change inreduction does not communicate to the chloroplast, and thatthe cell tolerates significant changes in NADP(H) reductionwithout deleterious effects.     

Vra4 congenic rats with allelic differences in the class II transactivator gene display altered susceptibility to experimental autoimmune encephalomyelitis

Presentation of Ag bound to MHC class II (MHC II) molecules to CD4+ T cells is a key event in adaptive immune responses. Genetic differences in MHC II expression in the rat CNS were recently positioned to allelic variability in the CIITA gene (Mhc2ta), located within the Vra4 locus on rat chromosome 10. In this study, we have examined reciprocal Vra4-congenic strains on the DA and PVGav1 backgrounds, respectively. After experimental nerve injury the strain-specific MHC II expression on microglia was reversed in the congenic strains. Similar findings were obtained after intraparenchymal injection of IFN-gamma in the brain. Expression of MHC class II was also lower on B cells and dendritic cells from the DA.PVGav1-Vra4- congenic strain compared with DA rats after in vitro stimulation with IFN-gamma. We next explored whether Vra4 may affect the outcome of experimental autoimmune disease. In experimental autoimmune encephalomyelitis induced by immunization with myelin oligodendrocyte glycoprotein, DA.PVGav1-Vra4 rats displayed a lower disease incidence and milder disease course compared with DA, whereas both PVGav1 and PVGav1.DA-Vra4 rats were completely protected. These results demonstrate that naturally occurring allelic differences in Mhc2ta have profound effects on the quantity of MHC II expression in the CNS and on immune cells and that this genetic variability also modulates susceptibility to autoimmune neuroinflammation.     

gesp: A computer program for modelling genetic effective population size,inbreeding and divergence in substructured populations

The genetically effective population size (N_e) is of key importance for quantifying rates of inbreeding and genetic drift and is often used in conservation management to set targets for genetic viability. The concept was developed for single, isolated populations and the mathematical means for analysing the expected N_e in complex, subdivided populations have previously not been available. We recently developed such analytical theory and central parts of that work have now been incorporated into a freely available software tool presented here. gesp (Genetic Effective population size, inbreeding and divergence in Substructured Populations) is R‐based and designed to model short‐ and long‐term patterns of genetic differentiation and effective population size of subdivided populations. The algorithms performed by gesp allow exact computation of global and local inbreeding and eigenvalue effective population size, predictions of genetic divergence among populations (G_ST) as well as departures from random mating (F_IS, F_IT) while varying (i) subpopulation census and effective size, separately or including trend of the global population size, (ii) rate and direction of migration between all pairs of subpopulations, (iii) degree of relatedness and divergence among subpopulations, (iv) ploidy (haploid or diploid) and (v) degree of selfing. Here, we describe gesp and exemplify its use in conservation genetics modelling.     

Cyp3a11 is not essential for the formation of murine bile acids

Humans and mice differ substantially in their bile acid profiles as mice in addition to cholic acid (CA) predominantly synthesize 6β-hydroxylated muricholic acids (MCAs) whereas humans produces chenodeoxycholic acid (CDCA) and CA as primary bile acids. Identifying the gene performing 6β-hydroxylation would be useful for ‘humanizing’ the bile acid profile in mice for studies of the interaction between bile acids, gut microbiota, and host metabolism. We investigated the formation of MCAs in primary murine hepatocytes and found that αMCA is synthesized from CDCA and βMCA from UDCA. It is commonly assumed that the P450-enzyme CYP3A11 catalyzes 6β-hydroxylation of bile acids, thus we hypothesized that mice without the Cyp3a11 gene would lack MCAs. To test this hypothesis, we analyzed bile acid profiles in Cyp3a deficient mice, which lack 7 genes in the Cyp3a gene cluster including Cyp3a11, and compared them with wild-type littermate controls. Bile acid composition in liver, gallbladder, caecum and serum from Cyp3a knock out mice and wild-type littermate controls was analyzed with UPLC-MS/MS and revealed no major differences in bile acid composition. We conclude that Cyp3a11 is not necessary for 6β-hydroxylation and the formation of MCAs.     

S4 charges move close to residues in the pore domain during activation in a K channel.

Voltage-gated ion channels respond to changes in the transmembrane voltage by opening or closing their ion conducting pore. The positively charged fourth transmembrane segment (S4) has been identified as the main voltage sensor, but the mechanisms of coupling between the voltage sensor and the gates are still unknown. Obtaining information about the location and the exact motion of S4 is an important step toward an understanding of these coupling mechanisms. In previous studies we have shown that the extracellular end of S4 is located close to segment 5 (S5). The purpose of the present study is to estimate the location of S4 charges in both resting and activated states. We measured the modification rates by differently charged methanethiosulfonate regents of two residues in the extracellular end of S5 in the Shaker K channel (418C and 419C). When S4 moves to its activated state, the modification rate by the negatively charged sodium (2-sulfonatoethyl) methanethiosulfonate (MTSES(-)) increases significantly more than the modification rate by the positively charged [2-(trimethylammonium)ethyl] methanethiosulfonate, bromide (MTSET(+)). This indicates that the positive S4 charges are moving close to 418C and 419C in S5 during activation. Neutralization of the most external charge of S4 (R362), shows that R362 in its activated state electrostatically affects the environment at 418C by 19 mV. In contrast, R362 in its resting state has no effect on 418C. This suggests that, during activation of the channel, R362 moves from a position far away (>20 A) to a position close (8 A) to 418C. Despite its close approach to E418, a residue shown to be important in slow inactivation, R362 has no effect on slow inactivation or the recovery from slow inactivation. This refutes previous models for slow inactivation with an electrostatic S4-to-gate coupling. Instead, we propose a model with an allosteric mechanism for the S4-to-gate coupling.