Miracle-dz/UniFAR-FTUs huggingface dataset:
GROWTH RATE VARIATION IN THE N:P REQUIREMENT RATIO OF PHYTOPLANKTON 1

Theoretical considerations predict that the cell N:P ratio at transition from nitrogen limitation to phosphorus limitation of phytoplankton growth (critical ratio, Rc) varies, as a function of population growth rate. This prediction is confirmed by experimental, data from the literature along with new experimental data for the marine, prymnesiophyte Pavlova lutheri (Droop) Green. Rc passes through a maximum at intermediate growth rates for the three phytoplankton species for which data, are available, but there is significant interspecific variability in its value. There is no theoretical or experimental evidence to support the idea that the ratio of subsistence N and P cell quotas is equal to Rc over the range of growth rates, or that the subsistence quota ratio equals the ratio of the N and P cell quotas minus a storage fraction. Examination of N:P composition ratios can be used to determine which nutrient is limiting, but cannot be used to determine relative growth rates or competitive advantage between species limited by the same nutrient. Growth rates are determined by environmental conditions and by the cell quota of the limiting nutrient, without reference to the cell quota of the non‐limiting nutrient.
Mechanical differences between free-standing and supported wheat plants, Triticum aestivum L

The effect of wind sway on the mechanical characteristics of the anchorage roots and the stem was investigated in mature winter wheat (Triticum aestivumL., cv. Hereward). Wheat plants were field-grown, either supported by a frame, which prevented wind sway, or unsupported (free-standing) and the morphology and mechanical properties of the stems and the anchorage, ‘coronal ’, roots were measured. Wind sway had little influence on either the stem height or ear weight of the plants but did affect the mechanical properties of the stem. Stems of supported plants were weaker and more flexible than the stems of free-standing plants. There were also differences in the anchorage systems between the treatments: supported plants had just under half as many ‘coronal ’ anchorage roots as the free-standing plants. This reduced the anchorage strength of supported plants by a third. These differences in mechanical structure meant that the free-standing plants were more resistant to stem buckling and more resistant to anchorage failure. However, considering the difference in the need for mechanical strength in plants from the two regimes, these differences were small. This suggests that wheat has inherent mechanical integrity and, as a monocotyledon with no secondary thickening, it differs little structurally between environments.
ESTIMATING NET PRIMARY PRODUCTION FROM MEASUREMENTS MADE ON SOIL ORGANIC MATTER

A model for the turnover of organic matter in soil, ROTHC-26.3, can be used to calculate how much organic C needs to enter a soil annually in order to maintain a specified stock of soil organic C. The annual return of organic C thus calculated, plus the amount of organic C removed annually from the site by harvesting, burning, etc., provides an estimate of the Net Primary Production (NPP) of that site, averaged over many years. The new method was used to calculate NPP for two adjacent savanna sites in the Nairobi National Park in Kenya, one grazed and one not, and for a dry Miombo woodland site in Zambia. Both the Kenyan and Zambian sites are taken to be at equilibrium, with soil organic C levels at steady state. Soils from the three sites were analyzed by layer for organic C, 814C, 813C, soil microbial biomass C, total N, pH, and clay content. Radiocarbon measurements were >100% modern in the surface layers (0-15 cm) of the Kenyan soils (both Vertisols) and in all three layers (0-15, 15-30 and 30-50 cm) of the Zambian soil (an Oxisol), presumably because of 14C coming from the testing of thermonuclear bombs. The 15-30 cm layer of the Kenyan soils dated at -500 yr and the 30-50 cm layer at -900 yr. The 14C data were consistent with the presence of a small inert fraction of organic C that accounted for an increasing proportion of total organic C with increasing soil depth. The 13C data indicated that the Kenyan soils had developed under C4 vegetation, whereas the Zambian soils had developed under vegetation dominated by C3 plants. From these results the annual input of C to soil from the ungrazed Kenyan site was calculated to be 388 g C.m-2-yr-l, to the grazed site 380 g C.m-2.yr-l, and to the Zambian soil 373 g C.m-2.yr-'. Taking the loss of C from the Kenyan sites by burning to be 40 g C.m-2.yr-l, the mean NPP for both Kenyan sites is 424 g C.m-2.yr-'. This value for NPP is compatible with earlier estimates of NPP by botanical methods from the same site in Kenya. Wood- taking is thought to be minimal in the protected Zambian woodland, so that here the annual input of C to the soil can be taken as the NPP without great error. This new method provides a long-term, integrated measure of NPP that should complement and enhance productivity measurements made by harvest methods over shorter periods.
Habitat use by the inland carpet python (Morelia spilota metcalfei: Pythonidae): Seasonal relationships with habitat structure and prey distribution in a rural landscape

Squamate reptiles are significant components of woodland vertebrate communities in eastern Australia, but their ecology is poorly understood. We investigated seasonal variation in habitat use by the Inland Carpet Python, Morelia spilota metcalfei Wells and Wellington (Pythonidae), a threatened snake that inhabits the woodland environments of the Murray-Darling Basin. Nine pythons were radiotracked within and near the Mount Meg Flora and Fauna Reserve in north-eastern Victoria to investigate how habitat structure and prey distribution (namely, that of the European Rabbit, Oryctolagus cuniculus L. (Leporidae)) influenced seasonal movement patterns. Data were analysed over three spatial scales to allow firm interpretations regarding resource selection. Pythons exhibited distinct seasonal trends in habitat use. During the cooler spring months, snakes chose warm, well-insulated microhabitats, primarily rocky outcrops on north- and north-west-facing hillsides. Pythons moved widely during the summer months, apparently in search of prey. Snake localities could be readily linked to rabbit distribution at this time. Specifically, snakes moved to more open, disturbed habitats that contained a high density of rabbits, and consistently selected microhabitats in close proximity to rabbit burrows. In autumn, habitat use was transitional, as snakes progressively returned to the rocky hillsides where they overwintered. Thus, trends in habitat use were influenced by the snakes' thermoregulatory and foraging strategies. Careful management of specific habitats and feral prey populations is required to conserve populations of this endangered snake.
Vagus Nerve Versus Helicobacter pylori : New View on Old Secrets of Gastroduodenal Pathology

Despite the long history of research on etiology and pathogenesis of gastroduodenal pathology, there are still a lot of unclear points in this field. Identification of Helicobacter pylori has been widely considered to be a major breakthrough in pathophysiology of gastroduodenal diseases. However, Helicobacter pylori infection, as a host-pathogen interaction, involves bidirectional cross-talk and requires assessment not only in terms of Helicobacter pylori virulence, but the immune reactivity of the host too. One of the major tasks of mucosal immunity is to discriminate between dangerous and harmless antigens, and it depends on neuroimmune cross-talk, which is orchestrated in gastroduodenal area by vagus nerve. In this review, we propose to recall and assess the role of the vagus nerve in the gastroduodenal homeostasis maintenance and anti-Helicobacter pylori fight, focusing on Helicobacter pylori-gastric mucosa-vagus nerve interaction. The following issues are discussed in this review: 1) Vagus nerve regulation of mucins production as a key element of gastrointestinal barrier against Helicobacter pylori colonization; 2) Virulence factors of Helicobacter pylori and cytoprotective effects of vagus nerve; 3) Peculiarities of Helicobacter pylori -induced innate immunity response, involving host cytokine network activation, and vagus nerve effects, realized through cholinergic anti-inflammatory pathway; 4) Modulation of maturation and activity of dendritic cells by Helicobacter pylori and acetylcholine; and 5) Alteration of adaptive immunity during Helicobacter pylori infection and role of acetylcholine. The structural and immune homeostasis of gastroduodenal area can be affected not only by Helicobacter pylori virulence factors, but
The insoluble cell wall polysaccharides of strawberries during the later stages of ripening and after preservation and storage under commercial conditions

Preparations containing the insoluble cell wall have been isolated from two varieties of strawberries at three stages during the ripening of the fruit and at intervals during 40 weeks' storage of fruit preserved under commercial conditions by (a) freezing, (b) sul-phiting or (c) canning. The component anhydro-sugars and ester groups making up the polysaccharide fraction of the preparations were determined. The results obtained suggest that marked changes in the texture of the strawberries occurring at various stages of the investigation were not accompanied by large changes in the composition of the insoluble cell wall polysaccharides.
Are you calling me primitive?

Lampreys are animals without bones or jaws, and yet they are prototype vertebrates. Related to hagfishes, the lampreys are cartilaginous fish with sucker-like mouths and are 550–450 million years old. These two groups comprise the agnathans and are reminiscent of Pikaia gracilens , the Cambrian fossil believed to be close to the first vertebrate. Despite lampreys and hagfish lacking bone and tooth enamel or other hard parts, they are still surprisingly well preserved in the fossil record. However, as a result of a paucity of fossils, the phylogeny of these groups is controversial and incomplete. Current evolutionary evidence suggests that hagfishes preceded the lampreys, with all three extant lamprey families coming from a common ancestor. The southern lamprey, Geotria australis , spends the first 4–5 years of its life in freshwater streams of southern hemisphere lands including Australia, New Zealand, South Africa, and South America. During this time, its eyes are only poorly developed. Although usually thought of as parasites, lampreys actually begin life as filter feeders, feasting mainly on detritus and unicellular algae. During …
Recent progress in the discovery of Akt inhibitors as anticancer agents

Akt, also referred to as protein kinase B (PKB) or Related to A and C (RAC), is one of the major direct downstream targets of phosphoinositide 3-kinase (PI3K). As it plays a central role in promoting cancer cell proliferation and survival through a growing list of key substrates, intense efforts are underway to find inhibitors of Akt for the treatment of cancer. Discovery of potent and novel inhibitors of Akt has been facilitated greatly by the availability of the X-ray structure of the active form of Akt and by its structural similarity with other serine/threonine kinases. In this review, new Akt inhibitors for the treatment of cancer are comprehensively reviewed, with emphasis on small molecule inhibitors that bind to the ATP-binding site, allosteric sites and the PH domains. Inhibitors of pseudosubstrates and antisense oligonucleotides, as well as Akt inhibitors with unknown mechanism of actions, are also reviewed. Results of clinical trials of several Akt drug candidates are briefly discussed. A brief summary of Akt structure and regulation and the evidences supporting Akt as a cancer target is provided as well. The patent literature is surveyed through July 2007.
Isolation and HPLC-TLC Analysis of the Major Flavonoids from Astragalus aitosensis

The identities of the isolated glycosides were established before and after partial or complete hydrolysis on the basis of their chromatographic behaviour and by HPLC analysis. Hydrolyses of the glycosides on TLC plates (Kiesel gel Flow rate: 1.Omllmin; temperature: 25°C; detection: 335nm; injection volume: 20 tl. The external standard method was used for the calibration curves of the main flavonoid aglycones and glycosides.
The success or failure of strains of Trifolium subterraneum L. in a Mediterranean environment

Five field experiments, three of which extended over a 9-year period, are described. Success or failure was assessed on a relative basis in three competitive situations, in each of which associated volunteer annuals were present. These situations were: (1) single-strain swards, (2) single-strain swards in association with an "indicator" strain at low initial density, and (3) mixed swards of several strains. The results support the hypothesis that the main determinant of success or failure of a strain of T. subterraneum in a mixed pasture is the seed-producing capacity of that strain when grown in ungrazed pure swards. More importantly, the form of the relationship between relative success and seed yield was shown to differ for each of the three competitive situations. Relative success was also related to "maturity grading" (a measure of earliness of flowering) since seed yield and maturity grading were themselves strongly related. However, partial regression analysis indicated no significant effects of maturity grading independent of seed yield. The importance of three further possible determinants of success or failure – seed size, petiole length, and hardseededness – is discussed. No evidence for their importance is adduced, except in the case of hardseededness under low rainfall conditions. Natural selection in multiple-strain swards is also discussed, and the need for further studies on factors associated with success or failure of closely related genotypes is emphasized.
Otolith growth and age estimation in the European hake

The internal sulcal rings in Merluccius merluccius otoliths cannot be considered as annuli. In the absence of a strong seasonal Zeitgeber, hake otoliths in the Mediterranean did not lay down an interpretable ring pattern that would be useful for age determination. A total of 484 sagittal otoliths from specimens ranging between 6 and 94 cm LT was studied in monthly samples from the Gulf of Lions in 1989‐1990. Transverse, burnt otolith sections was analysed with an image analysis system using enhanced and filtered images and using a fast Fourier transform (FFT) function to avoid subjectivity in ring interpretation. The otolith radius‐fish length relationship showed allometric growth and sexual dimorphism. The ring pattern was consistent for the sulcal rings in both sexes. Changes in the marginal increment showed the formation of multiple sulcal rings, of both environmental and physiological origin. The ring pattern depended on the sex and sexual activity. 1998 The Fisheries Society of the British Isles
Produtividade, qualidade dos frutos e estado nutricional de plantas de pepino, cultivadas em hidroponia, em função das fontes de nutrientes

Yield, fruit quality and nutritional status of cucumber plants cultivated in nutrient solutions, prepared with different nutrient sources, were evaluated. The experiment was carried out in greenhouse, being evaluated two groups of nutrient sources, to compose the nutritive solutions of vegetative growth and two groups to compose the nutritive solutions for fructification. The four treatments were disposed in the randomized blocks design with five replications. The nutritive solutions for vegetative growth were composed of 8; 2; 4; 2; 1 and 1 mmol L-1 of N, P, K, Ca, Mg and S and 35; 19; 21; 4; 0.9 and 0,7 mmol L-1 of Fe, Mn, B, Zn, Cu and Mo, respectively. The nutritive solutions for fructification were composed of 12; 3; 8.6; 3; 1.5; and 1.5 mmol L-1 of N, P, K, Ca, Mg and S, and 59; 28; 31; 4; 1.3; and 0.7 mmol L-1 of Fe, Mn, B, Zn, Cu and Mo, respectively. The phosphorus sources were KH2PO4 and H3PO4. This variation implied in the use of NaNO3, CaCl2 and KCl in the treatments 1 and 2; 3 and 4; and 2 and 4. Aodai cultivar seedlings, 21 days after sowing date (10 cm length), were grown in plastic recipient with 8.6 L of capacity, using a spacing of 0.40 x 0.70 m. Yield, fruit quality and plants nutritional status were evaluated, as well as the partition of Ca, Mg and K in the fruit. There were no significant differences between treatments. The average yield was 3.46 kg plant-1, crop cycle of 87 days corresponding to an average yield of 123 t ha-1 when considering the adopted spacing. Concentration of N, P, K, Ca, Mg and S in the leaves were 4.33; 0.77; 4.07; 6.20; 1.42; and 1.63 dag kg-1, respectively. Concentration of Fe, Mn and Cu in the leaves were 288; 960; and 13 mg kg-1, respectively. The partition pattern of Ca, Mg and K in the fruits was not constant during the evaluation.
Enzymes of cardiac energy metabolism in Amazonian teleosts and the fresh‐water stingray (Potamotrygon hystrix)

The maximal in vitro activity of key enzymes of energy metabolism was determined in heart from three Amazonian teleosts, matrincha (Brycon cephalus), acara acu (Astronaotus ocellatus) and tambaqui (Collossoma macropomum), as well as an elasmobranch, the fresh-water stingray (Potamotrygon hystrix). All species are obligate water breathers. Hearts of Amazonian teleosts have activity levels of the glycolytic enzymes hexokinase (HK), phosphofructokinase (PFG), pyruvate kinase (PK), and lactate dehydrogenase (LDH) similar to north temperate and Antarctic species when comparisons are made within the usual body temperature range. In contrast, activity level of enzymes required for aerobic oxidation of fatty acids, citrate synthase (CS), carnitine palmitoyl transferase (CPT), and 3-hydroxyacyl CoA dehydrogenase (HOAD) were all substantially lower in the Amazonian teleosts compared to other teleosts. The enzyme profile suggests that 1) activity levels of enzymes of carbohydrate metabolism are conserved over a wide range of body temperatures, and 2) Amazonian teleosts have a much greater reliance upon anaerobic metabolism from glucose than aerobic metabolism to sustain energy production. The heart of fresh-water stingray has high levels of CS, HK, PFK, and PK, implying an aerobic metabolism which is glucose based. In contrast to marine elasmobranchs, the fresh-water stingray has detectable levels of CPT and HOAD, suggestive of a capacity for low-level fatty acid catabolism. As such, the inability of muscle of marine elasmobranchs to utilize fatty acids as an energy source may not be common feature of all elasmobranchs. © 1996 Wiley-Liss, Inc.
Seed removal and survival in Asiatic black bear Ursus thibetanus faeces: effect of rodents as secondary seed dispersers

We investigated the fate of seeds of five tree species hill cherry Prunus jamasakura, Korean hill cherry P. verecunda, Japanese bird cherry P. grayana, giant dogwood Swida controversa and crimson glory vine Vitis coignetiae in the faeces of the Asiatic black bear Ursus thibetanus in a temperate forest in central Japan. Clarifying the fate of seeds dispersed by endozoochorous seed dispersers will enhance assessments of their roles as primary seed dispersers. We established several experimental treatments in the field. Each faeces sample was covered by cages with different mesh sizes which limited accessibility by animals (NM: no mesh, SM: 1 mm mesh and MM: 10 mm mesh). We examined whether seed removal varied among tree species and between mesh-size treatments from 2004 to 2007 (N = 625 samples). We set up an automatic camera trap 1.5 m above the ground at all NM treatments. In the NM treatments, the number of seeds of all tree species decreased immediately after the faeces were set. In June of the following year, < 1% of the seeds from any species remained in the vicinity of the faeces. However, we found 3.0-13.2% intact seeds of all species in the soil below the faeces, as well as within a 10-m radius around the faeces. In the NM treatments, most seed removals were observed within four days after the faeces were set. For all tree species in the MM treatment, most of the seeds were present on the surface of the soil, and 1-2% of the seeds germinated at the location where faeces were set. In the SM treatment, none of the seeds from any of the tree species disappeared and germinated. We took a total of 415 photographs at the NM sites, 97.8% of which were of rodents either holding or eating seeds. Many of the seeds contained in the bear faeces were removed and eaten by rodents. However, 2.1-5.1% of the seeds survived and germinated, which implies that rodents may also act as secondary seed dispersers.
SILICON METABOLISM IN DIATOMS: IMPLICATIONS FOR GROWTH 

Diatoms are the world's largest contributors to biosilicification and are one of the predominant contributors to global carbon fixation. Silicon is a major limiting nutrient for diatom growth and hence is a controlling factor in primary productivity. Because our understanding of the cellular metabolism of silicon is limited, we are not fully knowledgeable about intracellular factors that may affect diatom productivity in the oceans. The goal of this review is to present an overview of silicon metabolism in diatoms and to identify areas for future research.
Lipid oxidation inhibiting capacities of blackseed essential oil and rosemary extract

Lipid oxidation is the main deterioration process that occurs in vegetable oils containing lipid molecules with polyunsaturation. The aim of the present study was to investigate the possible effects of blackseed (Nigella sativa L.) essential oil (BEO) and rosemary (Rosmarinus officinalis L.) extract (RE) on stabilization of sunflower oil under accelerated storage conditions. RE was obtained by soxhlet extraction using methanol, whereas BEO was hydrodistilled from the blackseed extract obtained by extraction using petroleum ether (b.p. 40–60°C). The results indicate that both extracts stabilize sunflower oil to a certain extent, the extent being greater with RE than with BEO based on measurements of peroxide value, p-anisidine value, amount of nonoxidized linoleic acid in saponified oil samples by HPLC-DAD, concentration of conjugated diene hydroperoxide, and UV light absorption. The oil stabilizing effect of BEO against lipid oxidation, especially at concentrations of 0.06 and 0.1 g/100 g oil was found to increase as the temperature increased, according to principal component analysis results. Based on its strong lipid oxidation inhibiting capacity, RE can be used as a potential natural extract for stabilizing sunflower oil against oxidation. BEO, at carefully selected concentrations, can be suggested as an alternative supplement of plant origin for improving oil stabilization. Practical applications: Sunflower oil is a widely used vegetable oil for cooking and frying, and has a high linoleic acid content of about 40–70%. Here we show that sunflower oil can be stabilized by adding rosemary and blackseed extracts. The treatment can be useful especially in applications which require heating the oil to high temperatures.