We identified and characterised the deep red state (DRS), an optically-absorbing charge transfer state of PSII, which lies at lower energy than P680, in the red algae Cyanidioschyzon merolae by means of low temperature absorption and magnetic circular dichroism spectroscopies. The photoactive DRS has been previously studied in PSII of the higher plant Spinacia oleracea, and in the cyanobacterium Thermosynechococcus vulcanus. We found the DRS in PSII of C. merolae has similar spectral properties. Treatment of PSII with dithionite leads to reduction of cytochrome (cyt) b559 and the PsbV-based cyt c550 as well as the disassembly of the oxygen-evolving complex. Whereas the overall visible absorption spectrum of PSII was little affected, the DRS absorption in the reduced sample was no longer seen. This bleaching of the DRS is discussed in terms of a corresponding lack of a DRS feature in D1D2/cyt b559 reaction centre preparations of PSII., J. Langley, J. Morton, R. Purchase, L. Tian, L. Shen, G. Han, J.-R. Shen, E. Krausz., and Obsahuje bibliografické odkazy
Current debates on the nature of explanatory understanding have converged on the idea that at least one of the core components of understanding is inferential. Philosophers have characterized the inferential dimension of understanding as consisting of several related cognitive abilities to grasp a given explanation and the nexus of complementing explanations to which it belongs. Whilst analyses of both the subjective epistemic abilities related to grasping and objective features of the inferential links within explanations have received much attention, both within theories of explanation and in the literature on understanding, the criteria for evaluating the specific structure and organization of explanatory clusters or nexuses have received much less attention. Nevertheless, two notable exceptions stand out—Khalifa’s characterization of an explanatory nexus and theories of explanatory unification. I take Khalifa’s ideas, together with the basic criteria of successful explanatory unification, as my starting point. To both, I make some corrections and additions, in order to arrive at a more robust notion of an explanatory nexus and ultimately show that its structural properties and the inter-explanatory relations it contains are relevant to the resulting understanding. I propose to represent such nexuses as directed graph trees and show that some of their properties can be related to the degree of understanding that such nested explanatory structures can offer. I will further illustrate these ideas by a case study on an eco-logical theory of predation.
Very high pressure is required to generate hard faeces - 5-10 atmospheres. This is much more than can be supplied by the mechanical force from the muscular wall of the colon. Osmotic pressure (at least 200 mOsm) can generate the necessary suction forces required to consolidate faeces. The colon has a hypertonic absórbate (net above plasma - 500 mOsm) in uiuo. Fluorescence imaging of perifused rat descending colonic mucosa shows high steady state Na+ concentrations (600 mM) in the intercryptal extracellular space and low [Na + ] present in the crypt lumen. This [Na + ] distribution generates an osmotic pressure gradient across the crypt luminal wall resulting in a fluid inflow into the crypt lumen. Direct observation using confocal fluorescence microscopy of FITC dextran (mol. wt. 10 000) shows that there is concentration polarisation of the dextran in the upper 30 % of the crypt lumen. The time course and steady state distribution of concentration polarisation of fluorescent dyes within the crypt lumen permit an estimation of the fluid convection rate along the length of the crypt lumen. This is sufficient to account for the majority of fluid absorption by the colon. Observation of the suction force on agarose gels by rat descending colon in vivo shows that the colon generates up to 4 000 cm H2O suction pressure on the stiff gels, this is accompanied by a hypertonic absórbate from the gels of 800 mOsm. Disruption of the colonic musoca by bile salts reduces the suction pressure to about 40 cm H2O.
Slurs are both derogatory and offensive, and they are said to exhibit “derogatory force” and “offensiveness.” Almost all theories of slurs, except the truth-conditional content theory and the invocational content theory, conflate these two features and use “derogatory force” and “offensiveness” interchangeably. This paper defends and explains the distinction between slurs’ derogatory force and offensiveness by fulfilling three goals. First, it distinguishes between slurs’ being derogatory and their being offensive with four arguments. For instance, ‘Monday’, a slur in the Bostonian argot, is used to secretly derogate African Americans without causing offense. Second, this paper points out that many theories of slurs run into problems because they conflate derogatory force with offensiveness. For example, the prohibition theory’s account of offensiveness in terms of prohibitions struggles to explain why ‘Monday’ is derogatory when it is not a prohibited word in English. Third, this paper offers a new explanation of this distinction from the perspective of a speech act theory of slurs; derogatory force is different from offensiveness because they arise from two different kinds of speech acts that slurs are used to perform, i.e., the illocutionary act of derogation and the perlocutionary act of offending. This new explanation avoids the problems faced by other theories.
The current work describes two new species of Gyrodactylus von Nordmann, 1832 collected from pipefish Syngnathus scovelli (Evermann et Kendall) and Syngnathus typhle L. during two separate gyrodactylosis episodes on fish held in a public aquarium located in northern Italy. The gyrodactylids collected from the skin, fins and gills of pipefish were subjected to a morphological analysis of the attachment hooks and the morphometric data were compared to the four species of Gyrodactylus previously described from syngnathid hosts, namely G. eyipayipi Vaughan, Christison, Hansen et Shinn, 2010, G. pisculentus Williams, Kritsky, Dunnigan, Lash et Klein, 2008, G. shorti Holliman, 1963 and G. syngnathi Appleby, 1996. Principal components analysis (PCA) of the morphological data indicated six clusters; two discrete groups among the specimens taken from the pipefish held in the Italian aquarium and four further groups representing G. eyipayipi, G. pisculentus, G. shorti and G. syngnathi. Molecular sequences of the ribosomal internal transcribed spacers (ITS1 and ITS2) and the 5.8S gene for the new species considered here were then compared with those available for other species in GenBank. The comparison did not reveal any identical match, supporting the morphological analysis that Gyrodactylus corleonis sp. n. from S. typhle and Gyrodactylus neretum sp. n. from S. scovelli represent distinct species. Both G. corleonis and G. neretum possess robust hamuli, marginal hook blades that curve smoothly from their sickle base to a point beyond the toe and, ventral bars with a broad median portion and a reduced membrane. Gyrodactylus corleonis, however, can be distinguished on the basis of its heart-shaped ventral bar; G. neretum has a 1:2 hamulus point:shaft ratio and a rectangular-shaped ventral bar. A redescription of the haptoral hard parts of the four species previously recorded on pipefish is also presented.
The NKCA and KVCA small-aperture (~ 90 m) seismic arrays in western Bohemia represent the second deployment of this type in the Czech Republic. The arrays have a regular triangular geometric configuration with high gain three-component seismographs in each corner of the triangle. This allows very weak local earthquakes to be detected with a high degree of precision and, thereby, substantially enhances the results of the pre-existing local seismic network (WEBNET). This paper reports on the pilot measurement period. It summarises the final configuration of the arrays and compares the derived results. The measured data have been analysed using the DP/EP system developed by NORSAR. This incorporates several array techniques such as beamforming, f-k analysis, and the cross-correlation method. It has been shown that during the study period, the levels of seismic activity recorded by the seismic arrays were up to fifteen times greater than the levels recorded by the pre-existing seismic network., Jaroslav Štrunc and Milan Brož., and Obsahuje bibliografii
The aim of the present study was to determine the optimal initial tension, i.e. initial stretch for rat coronary artery when using the multi-wire myograph system. We used the normalization procedure to mimic physiological conditions and to stretch the coronary arterial segments to normalized internal circumference (IC 1 ). It is determined the internal circumference when the vessel relaxed under a transmural pressure of 100 mm Hg (IC 100 ), and the IC 1 is calculated by multiplying the IC 100 by a factor k. The impact of different factor k on the initial stretch and agonist- induced tension of coronary arteries were investigated. The results showed that the maximal agonist-induced tension was achieved at the factor k value of 0.90 and the initial stretch tension was given 1.16±0.04 mN/mm. The most appropriate factor k value was 0.90-0.95 and the most appropriate initial tension was 1.16-1.52 mN/mm. Th e equilibration time of the coronary artery segments should be at least 1.0 h. In the same optimal initial tension, the agonist-induced tension increased as equilibration time lengthened., N.-N. Ping ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
One of four Hoplobatrachus occipitalis (Günther, 1859) frogs received from Niger, West Africa was heavily infected with Lankesterella blood and pre-erythrocytic stages. Infected blood and tissues from this frog were force-fed to the remaining three frogs. Two survived to necropsy on days 14 and 27 post-feeding and were found to be infected with gamogonic and oogonic stages, respectively. The source of infection is inconclusive, as a natural origin cannot be excluded. Microgamont, macrogamont, oocyst and sporozoite structure and fine structure are described and found to conform in general, but not in detail, to previous descriptions. Gamonts and oocysts occurred predominantly in the liver and spleen. Walled sporulating oocysts were situated within macrophage centres. Oocysts yielded a progeny of 32 sporozoites. Pre-erythrocytic sporozoites developed within expanded inclusions, within their host cell, from which they massively invaded the liver and spleen, and to a lesser extent the lungs and kidneys. Sporozoites occurred in a parasitophorous vacuole in the erythrocytes. Conspecificity with Lankesterella dicroglossi Paperna et Ogara, 1996 reported from the same host species in Kenya remains uncertain due to several structural and developmental differences.