Amberlite IRA 900 versus calcium alginate in immobilization of a novel,engineered β-fructofuranosidase for short-chain fructooligosaccharide synthesis from sucrose

The immobilization of β-fructofuranosidase for short-chain fructooligosaccharide (scFOS) synthesis holds the potential for a more efficient use of the biocatalyst. However, the choice of carrier and immobilization technique is a key to achieving that efficiency. In this study, calcium alginate (CA), Amberlite IRA 900 (AI900) and Dowex Marathon MSA (DMM) were tested as supports for immobilizing a novel engineered β-fructofuranosidase from Aspergillus japonicus for scFOS synthesis. Several immobilization parameters were estimated to ascertain the effectiveness of the carriers in immobilizing the enzyme. The performance of the immobilized biocatalysts are compared in terms of the yield of scFOS produced and reusability. The selection of carriers and reagents was motivated by the need to ensure safety of application in the production of food-grade products. The CA and AI900 both recorded impressive immobilization yields of 82 and 62%, respectively, while the DMM recorded 47%. Enzyme immobilizations on CA, AI900 and DMM showed activity recoveries of 23, 27, and 17%, respectively. The CA, AI900 immobilized and the free enzymes recorded their highest scFOS yields of 59, 53, and 61%, respectively. The AI900 immobilized enzyme produced a consistent scFOS yield and composition for 12 batch cycles but for the CA immobilized enzyme, only 6 batch cycles gave a consistent scFOS yield. In its first record of application in scFOS production, the AI900 anion exchange resin exhibited potential as an adequate carrier for industrial application with possible savings on cost of immobilization and reduced technical difficulty.     

Blood Selenium Associated with Health and Fertility in Norwegian Dairy Herds

A survey of blood selenium (Se) concentrations in Norwegian Red heifers and dry period cows was conducted to reveal possible association to management, feeding, health and fertility. Selenium contents were determined in 254 herd blood samples consisting of pooled samples from individual non-lactating animals from herds in 5 counties. The Se concentrations showed a normal distribution with mean 0.09 μg Se/g blood, with a standard deviation (SD) of 0.05, and ranged from 0.02 to 0.23 μg/g, with 50 % of the samples being between 0.06 and 0.11 μg/g. The herds with Se concentrations below 0.06 μg/g were smaller (21.4 ± 8.7 cow-years) than those with Se levels above 0.11 μg/g (27.5 ± 14.1 cow-years) (P < 0.01), but there were no differences in milk yield, incidence of replacement, proportion of animal culling, amount of concentrate or grass silage as percentage of energy consumption between the groups. Treatment registration records showed a tendency that more animals in the low Se herds were treated for all the diseases included in this investigation (64.8 animals per 100 cow-years) than those in the high Se herds (57.5 per 100 cow-years), while no such differences were revealed for individual disorders. There was, however, a significant difference in bulk milk somatic cell counts (BMSCC) between low and high Se herds, their values being 137 000 and 155 000 cells/ml, respectively. This difference was significantly influenced by herd size. Furthermore, a total of 4 916 lactations were analyzed from individual health and fertility recordings, including 2 934 first lactations and 1 982 later lactations. The present study revealed a reduced incidence of disease treatment with increased Se concentrations from 0.02 to 0.23 μg Se/g blood. In this regard, there seemed to be an optimum of 0.10 to 0.15 μg Se/g for all types of mastitis treatments summarized, and for treatment of retained placenta. Thus, herd Se concentrations below and above these values was connected with increased probability for sum mastitis and retained placenta, reflecting the effect of the quadratic term of Se. The cow (composite) milk somatic cell count (SCC) was lower in lactations from low Se herds than in high Se herds with a marked SCC increase in the Se concentration interval from 0.11–0.13 μg/g blood. In conclusion, heifers and dry period cows in Norway are low in blood Se content and there seems to be a positive association between increased blood Se concentration pre partum and decreased incidence of mastitis, ovarian cysts and anoestrus/silent oestrus post partum.     

Mobility of moose—comparing the effects of wolf predation risk,reproductive status,and seasonality

In a predator–prey system, prey species may adapt to the presence of predators with behavioral changes such as increased vigilance, shifting habitats, or changes in their mobility. In North America, moose (Alces alces) have shown behavioral adaptations to presence of predators, but such antipredator behavioral responses have not yet been found in Scandinavian moose in response to the recolonization of wolves (Canis lupus). We studied travel speed and direction of movement of GPS‐collared female moose (n = 26) in relation to spatiotemporal differences in wolf predation risk, reproductive status, and time of year. Travel speed was highest during the calving (May–July) and postcalving (August–October) seasons and was lower for females with calves than females without calves. Similarly, time of year and reproductive status affected the direction of movement, as more concentrated movement was observed for females with calves at heel, during the calving season. We did not find support for that wolf predation risk was an important factor affecting moose travel speed or direction of movement. Likely causal factors for the weak effect of wolf predation risk on mobility of moose include high moose‐to‐wolf ratio and intensive hunter harvest of the moose population during the past century.     

Lessons on Evolution from the Study of Edaphic Specialization

Plants adapted to special soil types are ideal for investigating evolutionary processes, including maintenance of intraspecific variation, adaptation, reproductive isolation, ecotypic differentiation, and the tempo and mode of speciation. Common garden and reciprocal transplant approaches show that both local adaptation and phenotypic plasticity contribute to edaphic (soil-related) specialization. Edaphic specialists evolve rapidly and repeatedly in some lineages, offering opportunities to investigate parallel evolution, a process less commonly documented in plants than in animals. Adaptations to soil features are often under the control of major genes and they frequently have direct or indirect effects on genes that contribute to reproductive isolation. Both reduced competitiveness and greater susceptibility to herbivory have been documented among some edaphic specialists when grown in ‘normal’ soils, suggesting that a high physiological cost of tolerance may result in strong divergent selection across soil boundaries. Interactions with microbes, herbivores, and pollinators influence soil specialization either by directly enhancing tolerance to extremes in soil conditions or by reducing gene flow between divergent populations. Climate change may further restrict the distribution of edaphic specialists due to increased competition from other taxa or, expand their ranges, if preadaptations to drought or other abiotic stressors render them more competitive under a novel climate.     

Long-term platinum retention after treatment with cisplatin and oxaliplatin

Background  

The aim of this study was to evaluate long-term platinum retention in patients treated with cisplatin and oxaliplatin.     

Anadromy,potamodromy and residency in brown trout Salmo trutta: the role of genes and the environment

Brown trout Salmo trutta is endemic to Europe, western Asia and north-western Africa; it is a prominent member of freshwater and coastal marine fish faunas. The species shows two resident (river-resident, lake-resident) and three main facultative migratory life histories (downstream–upstream within a river system, fluvial–adfluvial potamodromous; to and from a lake, lacustrine–adfluvial (inlet) or allacustrine (outlet) potamodromous; to and from the sea, anadromous). River-residency v. migration is a balance between enhanced feeding and thus growth advantages of migration to a particular habitat v. the costs of potentially greater mortality and energy expenditure. Fluvial–adfluvial migration usually has less feeding improvement, but less mortality risk, than lacustrine–adfluvial or allacustrine and anadromous, but the latter vary among catchments as to which is favoured. Indirect evidence suggests that around 50% of the variability in S. trutta migration v. residency, among individuals within a population, is due to genetic variance. This dichotomous decision can best be explained by the threshold-trait model of quantitative genetics. Thus, an individual's physiological condition (e.g., energy status) as regulated by environmental factors, genes and non-genetic parental effects, acts as the cue. The magnitude of this cue relative to a genetically predetermined individual threshold, governs whether it will migrate or sexually mature as a river-resident. This decision threshold occurs early in life and, if the choice is to migrate, a second threshold probably follows determining the age and timing of migration. Migration destination (mainstem river, lake, or sea) also appears to be genetically programmed. Decisions to migrate and ultimate destination result in a number of subsequent consequential changes such as parr–smolt transformation, sexual maturity and return migration. Strong associations with one or a few genes have been found for most aspects of the migratory syndrome and indirect evidence supports genetic involvement in all parts. Thus, migratory and resident life histories potentially evolve as a result of natural and anthropogenic environmental changes, which alter relative survival and reproduction. Knowledge of genetic determinants of the various components of migration in S. trutta lags substantially behind that of Oncorhynchus mykiss and other salmonines. Identification of genetic markers linked to migration components and especially to the migration–residency decision, is a prerequisite for facilitating detailed empirical studies. In order to predict effectively, through modelling, the effects of environmental changes, quantification of the relative fitness of different migratory traits and of their heritabilities, across a range of environmental conditions, is also urgently required in the face of the increasing pace of such changes.     

Alteration of the N-glycome of bovine milk glycoproteins during early lactation

Milk provides nutritional, immunological and developmental components for newborns. Whereas identification of such components has been performed by targeting proteins and free oligosaccharides, structural and functional analyses of the N-glycome of milk glycoproteins are scarce. In this study, we investigated, for the first time, the alterations of the bovine milk N-glycome during early lactation (1 day, 1, 2, 3 and 4 weeks postpartum), characterizing more than 80 N-glycans. The glycomic profile of colostrum on day 1 after calving differed substantially from that in other periods during early lactation. The proteins in colostrum obtained 1 day postpartum were more highly sialylated than milk samples obtained at other time points, and the N-glycolylneuraminic acid (Neu5Gc)/N-acetylneuraminic acid (Neu5Ac) ratio was significantly higher on day 1, showing a gradual decline with time. In order to dissect the N-glycome of colostrum, alterations of the N-glycosylation profile of major bovine milk proteins during the early lactation stage were elucidated, revealing that the alteration is largely attributable to qualitative and quantitative N-glycosylation changes of IgG, the major glycoprotein in colostrum. Furthermore, by preparing and analyzing IgGs in which the N-glycan structure and subtypes were well characterized, we found that the interaction between IgG and FcRn was not affected by the structure of the N-glycans attached to IgG. We also found that bovine FcRn binds IgG(2) better than IgG(1) , strongly suggesting that the role of FcRn in the bovine mammary gland is to recycle IgG(2) from the udder to blood, rather than to secrete IgG(1) into colostrum.     

The vertical distribution of N and K uptake in relation to root distribution and root uptake capacity in mature Quercus robur, Fagus sylvatica and Picea abies stands

We have measured the uptake capacity of nitrogen (N) and potassium (K) from different soil depths by injecting ¹⁵N and caesium (Cs; as an analogue to K) at 5 and 50 cm soil depth and analysing the recovery of these markers in foliage and buds. The study was performed in monocultures of 40-year-old pedunculate oak (Quercus robur), European beech (Fagus sylvatica) and Norway spruce (Picea abies (L.) Karst.) located at an experimental site in Palsgård, Denmark. The markers were injected as a solution through plastic tubes around 20 trees of each species at either 5 or 50 cm soil depth in June 2003. After 65 days foliage and buds were harvested and the concentrations of ¹⁵N and Cs analysed. The recovery of ¹⁵N in the foliage and buds tended to be higher from 5 than 50 cm soil depth in oak whereas they where similar in spruce and beech after compensation for differences in immobilization of ¹⁵N in the soil. In oak more Cs was recovered from 5 than from 50 cm soil depth whereas in beech and spruce no difference could be detected. Out of the three investigated tree species, oak was found to have the lowest capacity to take up Cs at 50 cm soil depth compared to 5 cm soil depth also after compensating for differences in discrimination against Cs by the roots. The uptake capacity from 50 cm soil depth compared with 5 cm was higher than expected from the root distribution except for K in oak, which can probably be explained by a considerable overlap of the uptake zones around the roots and mycorrhizal hyphae in the topsoil. The study also shows that fine roots at different soil depths with different physiological properties can influence the nutrient uptake of trees. Estimates of fine root distribution alone may thus not reflect the nutrient uptake capacity of trees with sufficient accuracy. Our study shows that deep-rooted trees such as oak may have lower nutrient uptake capacity at deeper soil layers than more shallow-rooted trees such as spruce, as we found no evidence that deep-rooted trees obtained proportionally more nutrients from deeper soil layers. This has implications for models of nutrient cycling in forest ecosystems that use the distribution of roots as the sole criterion for predicting uptake of nutrients from different soil depths.     

A lateral-displacement flume for fish behavior and stranding studies during simulated pulsed flows

In regulated rivers, fluctuating water depths associated with pulsed discharges may strand small fish in side channels and pools. Quantitative assessments of stranded fish are difficult in field studies (e.g., due to unknown effects of avian and terrestrial vertebrate predators). To assess such lateral displacement and stranding on juvenile stream fishes, we designed, constructed, and tested (with three species) a 2 × 1-m, lateral-displacement flume. The flume featured a main channel that never drained and a raised, wide “floodplain” channel that alternately flooded, with a simulated pulse, and became dewatered. The floodplain contained four pools, with different shapes and draining capacities, in which fish could become stranded as the water level subsided. Fish-stranding rates (8%) in this relatively compact laboratory flume, after exposure to simulated pulsed stream flows, were comparable to those observed in past investigations using larger, artificial streams.     

Informing conservation by identifying range shift patterns across breeding habitats and migration strategies

A species distribution combines the resources and climatic tolerances that allow an individual or population to persist. As these conditions change, one mechanism to maintain favorable resources is for an organism to shift its range. Much of the research examining range shifts has focused on dynamic distribution boundaries wheras the role of species breeding habitat or migration strategies on shift tendencies has received less attention. We expand on previous research by using a large suite of avian species (i.e., 277), analyzing observed abundance-weighted average latitudes, and categorizing species by breeding environment and migration strategy. We used the North American Breeding Bird Survey dataset to address two questions: (1) Has the center of observed abundance for individual species shifted latitudinally? (2) Is there a relationship between migration strategy or breeding habitat and range shifts? Results indicate the majority of species have experienced poleward range shifts over the last 43 years, and birds breeding in all habitat showed trends of poleward shift but only those species breeding in scrub-shrub and grassland environments were different from zero. Additionally, species that are short distance migrants are experiencing significant poleward shifts while Neotropical and permanent residents had shifts that were not different from zero. Our findings do support the general trend expected from climate driven changes (i.e., > 52 % shifting poleward), however, the proportion of species exhibiting equatorial shifts (24 %) or no significant shifts (23 %) illustrates the complex interplay between land cover, climate, species interactions, and other forces that can interact to influence breeding ranges over time. Regardless of the mechanisms driving range shifts, our findings emphasize the need for connecting and expanding habitats for those species experiencing range shifts. This research describes the patterns of breeding birds through central North America and we encourage future research to focus on the mechanisms driving these patterns.