Thermomyces lanuginosus lipase in the liquid-crystalline phases of aqueous phytantriol: X-ray diffraction and vibrational spectroscopic studies

The influence of Thermomyces lanuginosus lipase (TLL) on the phase behaviour of liquid-crystalline phases of aqueous phytantriol as well as conformational changes of TLL entrapped in the cubic Q230 phase have been studied by small angle X-ray diffraction (SAXD), FT-Raman, and FT-IR techniques. It was found that the lipidic Q230 phase is able to accommodate up to 10 wt.% of TLL, and the temperature of phase transition to the inverted hexagonal phase H(II) increases indicating stabilizing effect of the protein. FT-Raman analysis of Trp amino acid marker band W3 revealed that the average rotation angle around the C3-Cbeta bond of four Trp residues of TLL in the Q230 phase increases. Reasoning from available TLL crystallographic data, this result is explained by structural transition of entrapped protein to so-called "open" and more related to the enzymatically-active conformation. TLL secondary structure analysis by amide I and amide III vibrational bands showed that content of alpha-helixes does not change, while a part of beta-sheet structures transforms to less ordered elements upon incorporation of protein into the Q230 phase of aqueous phytantriol.     

Characterization of cellulosic fibers and fabrics by sorption/desorption

Three cellulosic substrates: lyocell (CLY), viscose (CV), and modal (CMD) in the form of fibers and fabrics were subjected to wet/dry or wash/dry treatments. The accessibility of untreated and treated substrates to water and iodine was investigated using dynamic water-vapor sorption, moisture retention, and iodine sorption methods, to study the influence of treatments on sorption-desorption hysteresis, fraction of moisture sorbed as a monomolecular layer, water retention, and iodine sorption. It was found that the sorption properties of untreated and treated substrates differed with sorbate type as well as substrate type and form.     

Delayed luminescence of Prorocentrum minimum under controlled conditions

Delayed luminescence (DL), also termed delayed fluorescence or delayed light emission, is the phenomenon of long-lived light emission by plants and cyanobacteria after being illuminated with light and put into darkness. Culture growth of three Prorocentrum minimum strains was studied with DL measurements. DL decay kinetics was measured from 1–60 s after a pulse of white light. The strains used were from the Adriatic Sea (PmK), from Chesapeake Bay, USA (D5), and from the Baltic Sea (BAL), cultured at salinity of 32, 16, and 8 (practical salinity scale), respectively. The strains differed in cell size and chlorophyll a content (PmK > D5 > BAL), as well as in DL parameters. The DL results were compared to standard measurements of culture density and carbon content (calculated from biovolumes). DL decay curves had a specific peak, which changed with culture growth and showed more similarities between the strains PmK and D5. The DL intensity increased with cell density and carbon content in a two-stage process, corresponding to the lag and exponential phases of growth. DL intensity was best correlated with carbon content irrespective of strain and is proposed as an estimate of biomass and for differentiating between lag and exponential phases of growth.     

Dynamics of dissolved and particulate organic carbon in a saline and semiarid stream of southeast Spain (Chicamo stream)

Annual variations in the concentration of dissolved (DOC) and particulate organic carbon (CPOC = Coarse; FPOC = Fine; UPOC = Ultrafine) were studied in a 100 m-reach of the Chicamo stream, an intermittent saline stream in southeast Spain. DOC represented the most important fraction of organic carbon flowing in the Chicamo stream (>98%), with concentrations of about 1.7 mgC l^–1 during most of the year, reaching 2.5 mgC l^–1 in summer. One high flow episode during a rain storm in winter was characterized by a considerably increased concentration of DOC (9.4 mgC l^–1). CPOC was the dominant POC fraction. Positive and significant correlations were found for DOC and discharge, which support the idea of allochthonous inputs due to floods. There was no significant correlation between POC and discharge. No significant correlations were found for DOC or POC with the physico-chemical parameters measured, while a negative significant correlation was found between DOC and temperature. The export of total organic carbon from the drainage basin of the Chicamo stream was low (6.2 × 10^–4 gC m^–2 yr^–1) and typical of streams in arid and semi-arid regions. The results of a Principal Component Analysis defined three different phases. The first consisted of short periods, during which floods provide pulses of allochthonous organic carbon and nutrients, the second a dry phase (summer), defined by biotic interactions, during which the stream could acts as a `sink' of organic matter, and the third and final phase which is characterised by hydrological stability.     

Location and interseasonal variation in flowering, propagule setting and propagule size in mangroves species of the family Rhizophoraceae

Three species of mangroves, Rhizophora stylosa, Rhizophora mangle (synonym R. samoensis) and Bruguiera gymnorhiza in the family Rhizophoraceae were studied to understand the flowering pattern, propagule development and the propagule size at maturity prior to dispersal from the mother plant. The study was conducted in the Wet and the Dry zones over two seasons in Viti Levu, the Main Island of Fiji. The flower number, number of propagules and propagule size at maturity were significantly different among three species and within species in the Dry and the Wet zones. Only 1–2% of total flowers in each species became mature propagules. This percentage was significantly lower in the Dry zone for all three species. Rhizophora stylosa produced the biggest size of propagules followed by Rhizophora mangle and Bruguiera gymnorhiza. Relatively longer and heavier propagules were recorded in the Wet zone and shorter and lighter in the Dry zone. Inter-seasonal differences were not significant for these characters. This could be mainly due to almost similar amount of rainfall, relative humidity and temperature regimes over two seasons within each zone.     

Physiological interaction model of sunflower plant with its nutrient medium during ontogenesis

A study was conducted with sunflower plants (Helianthus annuus, L.) cv. Peredovik in field experiments, one of which included 9 NPK-fertilizer treatments. The intensity of uptake,i.e. the quantity (mg) of nutrient taken up for the accumulation of 1 g dry matter/day, the concentrations of all essential elements in the plant organ tissues and their distribution among above-ground organs, by stages of development, were investigated. The results have revealed the inherent physiological system responsible for the uptake intensity of individual elements, as well as the simultaneous uptake and distribution of all essential elements of the root nutrition by the shoots, throughout the life cycle of the plant.     

Record performances at the Boston Marathon: Biometeorological factors

Air temperature and relative humidity have long been suspected of affecting the performance of marathon runners. Though these factors are important in their extremes, we show that other factors are even more indicative of race performances. Performances of the top 3 finishers in the last 30 Boston Marathons were correlated with hourly meteorological data for each race day. These 90 individual performances were classified as: record breaking performances (31), average performances (35), and unusually slow performances (24). The factors that help predict record breaking and unusually slow performances are: (i) wet bulb temperature, (ii) percent sky cover, and (iii) presence or absence of a light precipitation. Record breaking performances are characterized by a wet bulb temperature of <7.8°C, and 100% sky cover. A light drizzle is also conducive to better performances. On the other hand, unusually low performances are accompanied by a wet bulb temperature of >7.8°C, and a sky cover of 50% or less. No light, precipitation was recorded on any of the unusually slow race days. A graphic analysis clearly shows these relationships to exist. In addition, a multiple regression analysis confirms the importance of these variables. The authors advise that these are reliable predictors; however, when considering marathon races held in various geographical regions and differing climatic regimes, the exact numerical thresholds used here may not apply.     

Global diversity of springtails (Collembola; Hexapoda) in freshwater

Water-dependency appeared independently in several clades of the class Collembola, which is basically of terrestrial origin according to recent phylogenetic analyses. Though moderately diversified (less than 8,000 species), Collembola are among the most numerous terrestrial arthropods in wetland communities, with a small number of species living on the surface of water. Many species are dependent on water-saturated atmosphere of caves, and on snow or ice in high mountains. A total of 525 water-dependent species have been recognized, of which 103 are linked to free freshwaters and 109 to anchialine or marine waters. Many interstitial species are also dependent to an unknown extent on water saturation in the deep layers of the soil. The numbers provided here are underestimates, as Collembola are extremely poorly known outside the Holarctis, and the ecology of described species usually not documented. However, a general biogeographical pattern is emerging from available data. The most remarkable feature is that about 15% of the fauna is water-dependent in the holarctic region, compared to 4% in the tropics and southern hemisphere. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. Guest editors: E. V. Balian, C. Lévêque, H. Segers & K. Martens Freshwater Animal Diversity Assessment     

Genetic and allelopathic differences between populations of daisy fleabane Erigeron annuus (L.) Pers. (Asteraceae) from disturbed and stable habitats

The interactions between invasive plants and their habitats may vary at different phases of the invasion process and depend on the phenotypic plasticity or local adaptations of each species. In this study, we investigated whether habitat changes during the invasion process are related to variations in the physiological traits (allelopathic properties) and genetic differentiation of daisy fleabane (Erigeron annuus (L.) Pers.). E. annuus is a winter annual invasive species that originated in North America and is now distributed throughout Europe. Genetic and genotypic diversity analyses were performed for 37 populations of E. annuus based on inter simple sequence repeat (ISSR) polymorphisms. In total, 684 plants were analyzed; 342 were from stable habitats and 342 were from disturbed habitats. The genetic differences among the populations from the different habitats were studied using a Bayesian cluster analysis and an analysis of molecular variance (AMOVA) and by calculating the genetic and genotypic diversity parameters. A germination test using the juglone index was employed to examine the potential allelopathic properties of the plants from the different habitats. Bayesian cluster analysis, AMOVA and allelopathic effects evaluation revealed differences in the allelopathic potential and genetic structure of the E. annuus populations from the disturbed and stable habitats. This differentiation of populations could be associated with founder effects or with different selection pressures among habitats.