Miracle-dz/UniFAR-FTUs huggingface dataset:
DISTRIBUTION OF INTRACELLULAR NITROGEN IN MARINE MICROALGAE: BASIS FOR THE CALCULATION OF SPECIFIC NITROGEN‐TO‐PROTEIN CONVERSION FACTORS

The utilization of nitrogen‐to‐protein conversion factors (N‐Prot factors) is a widely accepted and practical way to determine total protein content. The accuracy of protein determination depends on the establishment of specific N‐Prot factors, since the conventional factor of 6.25 may be unsuitable for all species. This study was designed to determine the concentrations of the main nitrogenous compounds and to establish N‐Prot factors specific for the following marine microalgae: Chlorella minutissima, Dunaliella tertiolecta, Hillea sp. , Isochrysis galbana, Nannochloropsis oculata, Phaeodactylum tricornutum, Prorocentrum minimum, Skeletonema costatum, Synechococcus subsalsus, and Tetraselmis gracilis. Cultures were maintained under a 12‐h photoperiod (300 μmol photons·m−2·s−1) at temperatures of 20.0°± 1.0° C (dark) to 23.0°± 2.0° C (light) in Walne’s culture medium without additional external carbon sources. The distribution of intracellular nitrogen was studied by determining total nitrogen (TN, by CHN [carbon, hydrogen, and nitrogen] analysis), protein N (PN, by analysis of total amino acids), and nonprotein N (NPN, determined by analysis of DNA, RNA, chlorophylls (chl) a,b, and c, and intracellular inorganic nitrogen—NO3−, NO2−, and NH3+ NH4+) in logarithmic and stationary growth phases of cultures. Variations occurred in both accumulation and distribution of PN and NPN among the species, as well as in each species during the different growth phases. Inorganic nitrogen compounds were observed to be the most important NPN source (from 6.4 ± 0.1% to 41.8 ± 4.2% of total N) in all species (except D. tertiolecta), followed by nucleic acids (from 0.8 ± 0.1% to 26.1 ± 2.4% of TN) and chlorophylls (from 0.2 ± 0.0% to 3.1 ± 0.3% of TN). Total amino acid residues ranged from 63.1 ± 4.6% up to 88.1 ± 11.2% of TN, which is in agreement with the presence of high NPN concentrations. N‐Prot factors are proposed for each growth phase in the studied species, based on the ratio of amino acid residues to TN, establishing specific N‐prot factors ranging from 3.60 ± 0.27 to 4.99 ± 0.64. The mean N‐Prot factor for all species/growth phases was 4.58 ± 0.11. The present study shows that the use of the traditional factor 6.25 is not suitable for these marine microalgae, and possibly for other species, because it overestimates their actual protein content.
Potency of Bacillus thuringiensis and Bacillus subtilis against the cotton leafworm, Spodoptera littoralis (Bosid.) Larvae

The biological activities of two species of bacteria isolated from soil of cotton fields identified as Bacillus subtilis strain NRC313 (BS NRC313) and Bacillus thuringiensis strain NRC335 (BT NRC335) were evaluated against the third larval instar of the cotton leafworm, Spodoptera littoralis (Boisd.). The different entomopathogenic bacteria of BS NRC313and BT NRC335 contained 10 × 108 cell/ml, and caused mortality of 100 and 97.3% for the above mentioned strains, respectively. Concentrations of 2.5 × 108 to 10 × 108 cell/ml of strains BS NRC313 and BT NRC335 were applied to the larvae: LC50 were 3.3 × 108 and 3.9 × 108 cell/ml respectively. The influence of exposure to toxin concentrations manifested in terms of decreasing the adult emergence and prolongation of the generation period. The percentage of larvae that survived and succeeded to pupate increased by decreasing the concentration. The longevity of adult emergence that resulted from larvae treated with Bacillus subtilis were 6.0 ± 0.51 and 9.0 ± 0.63 days at 5 × 108 and 2.5 × 108 cell/ml, respectively compared with 9.8 ± 0.47 in control. The results indicated that Bacillus subtilis was more potent than Bacillus thuringiensis. Field applications of B. thuringiensis, B. subtilis and Reldan achieved 55.6, 67.4 and 89.4% reduction of the cotton leafworm larvae Spodoptera littoralis in clover plants under field conditions.
Reversible Enzyme Inhibition–Based Biosensors: Applications and Analytical Improvement Through Diagnostic Inhibition

Abstract The present review reports the research carried out during past 9 years on biosensors based on reversible enzyme inhibition for determination of drugs, pollutants, and toxic compounds. Applications in food, environmental, and pharmaceutical fields are also reported. Special attention is paid to the optimization of parameters such as enzyme immobilization, substrate concentration, and incubation time. On the basis of the studies reviewed here, it is our view that enzyme inhibition–based biosensors have been shown to be useful analytical tools.
Changes in the expression of αv integrins in oral squamous cell carcinomas

Integrins are cell surface adhesion molecules that regulate normal cellular interactions; aberrant integrin expression is believed to play a role in tumour invasion and metastasis. The alpha v subunit is capable of forming heterodimers with several beta subunits but not all the heterodimers expressed in oral epithelium have been investigated. We have examined the distribution of alpha v integrins in normal buccal mucosa and seventeen oral squamous cell carcinomas. Antibodies to the alpha v subunit and alpha v beta 5 heterodimer stained normal epithelium, with strong expression in the basal layers and weaker staining in the more superficial layers. The beta 3 and beta 6 subunits were not expressed in normal epithelium. Anti-alpha v and anti-alpha v beta 5 antibodies stained all the squamous cell carcinomas, but the pattern of expression was variable both within and between tumours. Poorly differentiated tumours showed the weakest staining and often had areas showing loss of expression. beta 6 was expressed in all of the carcinomas, indicating new expression of the alpha v beta 6 integrin in malignant oral epithelium. These results suggest that alterations in alpha v integrins may contribute to the behaviour of malignant epithelium and that alpha v beta 6 expression may play a role in tumour progression.
Effect of trace elements and vitamins on the growth of Methanosarcina barkeri

Growth of Methanosarcina barkeri on methanol as energy source was found to be dependent on cobalt and molybdenum. In the presence of 10−6 M Co and 5 × 10−7M Mo optimal growth occurred. Furthermore it could be demonstrated that nickel and selenium each in a concentration of 10−7 M stimulated the growth of this methanogenic bacterium while the following elements tested in the range of 10−7 M to 10−3 had no influence: B, Cr, Cu, Mn, Pb. The requirement of Co and Ni for optimal growth are in accordance with the results that the cells contain the Co containing corrinoid Factor III (0.1 – 0.2 mg 5-hydroxylbenzimidazolylcyanocobamide per g wet cells) and Factor F430, a nickel component. Studies on the vitamin dependency of M. barkeri showed that this strain needs only the vitamin riboflavin for the growth in a defined medium. Under these conditions a cell density of 2.6 g dry cells/l could be obtained in a fed batch culture.
SHORT CHAIN FATTY ACID INHIBITION OF RAT BRAIN Na‐K ADENOSINE TRIPHOSPHATASEI

Abstract— The possibility was considered that the sleep‐like state seen after injection of short chain fatty acids salts into animals is a result of inhibition of the sodium‐potassium activated ATPase. Tris salts of short chain fatty acids inhibited brain Na‐K ATPase activity in vitro at concentrations similar to intravenous levels causing narcosis in vivo. The inhibition depended on the logarithm of the concentration of a given acid. The concentration of acid anion which caused 50 per cent inhibition of the enzyme system (I50) was determined for straight and branched chain acids with 4–12 carbon atoms per molecule. The log of I50 concentrations plotted against the number of carbon atoms in the molecule gave a straight line; the inhibitory capacity of an acid increased by a factor of 2·3 for each ‐CH2‐ added to the carbon chain.
Comparative and functional leaf anatomy of selected Alstroemeriaceae of mainly Chilean origin

The resupinate leaves of 16 species of Alstroemeriaceae were examined using light- and scanning electron microscopy. The leaf anatomy is described for all of the species, that of the petiole and stem for selected species. The mesophyll consists of chlorenchyma and includes idioblasts that contain raphides. Dorsiventral, isolateral or isobilateral leaf types were observed. Petioles are always isolateral. Two epidermal types are commonly observed: type I contains jigsaw puzzle-like intercostal cells and longitudinally elongated cells above the veins; type II contains only longitudinally elongated cells, usually longer, above the veins. Some species have an epidermis which differs from the main types. All species show adaptation to resupination by having an inverted anatomy. Due to the twist of the leaves, adaxial indicates the lower surface and abaxial the upper. Stomata are found on both surfaces. Palisade cells, when they occur, are always on the abaxial surface. Most species are mesomorphic in spite of the dry environments in which they grow; a few show xeromorphic features. The leaves are compared and discussed with relation to ecological conditions. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society, 2002, 140, 261−272.
Proposed Empirical Standard Weight Equation for Brook Chub Squalius lucumonis

Abstract Relative weight (Wr ) is an index of condition that enables evaluation of the well-being of fish by comparing the actual weight of a specimen with the ideal weight of a specimen of the same species and the same length that is in good physiological condition (i.e., the standard weight [Ws ]). This index was primarily developed to assess the status of sport fishes. Recently, however, many authors have encouraged the use of this index as a fisheries assessment tool for nongame species as well, especially those that are endangered or threatened. Length and weight data on brook chub Squalius lucumonis, an Italian endemic species listed as endangered by the International Union for the Conservation of Nature, were collected across its area of distribution and used to compute a standard weight (Ws ) equation by means of the empirical percentile method. The Ws equation thus obtained (log10 Ws = –7.75 + 5.75 log10[total length {TL}] – 0.66 [log10TL]2; TL range of application = 90–210 mm) was not biased by .
Life History Studies on the Genus Trillium (Liliaceae) I. Reproductive Biology of Four Japanese Species

Four Japanese Trillium (Liliaceae) species which are representative perennial herbs of the temperate deciduous forests—Trillium kamtschaticum (2x), T. apetalon (4x), T. tschonoskii (4x) and T. smallii (6x)—were studied for their reproductive characteristics, e.g., patterns of reproductive resource allocation and reproductive output. In spite of the differences in ploidy levels (from 2x to 6x), all four species showed very similar reproductive traits. It became evident that in response to the increase in reproductive allocation to total reproductive organs (RA), the number of seeds produced per plant (PN) clearly increased. This trend is well in accord with the relationship found in four North American species and also several temperate woodland perennial herbs which occur in closed, stable and predictable environments, and possess typical xenogamous breeding systems. Although there is no conspicuous trend between ploidy levels and PN, one of the significant differences noted in this study was in seed weight, which ranged from 2.93 mg in diploids, to 3.42–3.45 mg in tetraploids, and to 4.47 mg in hexaploids.
Correlates and Fitness Consequences of Natal Dispersal in Swainson's Hawks

Abstract. Natal dispersal is an important, yet often poorly studied, process in population ecology. Natal dispersal can affect population structure and individual fitness. We examined correlates of natal dispersal distances of a population of Swainson's Hawk (Buteo swainsoni) in northern California that has been monitored from 1979 to 2010. We examined the effects of sex, number of offspring fledged, population density, primary productivity around a nest site, and annual trends on dispersal from the natal site to the breeding site of individuals recruited into the breeding population. Female Swainson's Hawks dispersed farther than males. Natal dispersal was negatively correlated with primary productivity and was positively correlated with population density around the nest site. We found no correlation between natal dispersal distance and lifetime reproductive success of those individuals recruited into the breeding population, indicating no fitness costs of increased dispersal. We examined the potential genetic contributions to dispersal distance by examining differences in dispersal distance between full siblings. We found that the dispersal difference between siblings was significantly more similar than would be expected by chance. However, we detected no relationships between paternal or maternal natal dispersal distances and natal dispersal of offspring, although sample sizes were limited. We conclude that observed similarities in siblings' natal dispersal distance were likely a result of similarities in unmeasured environmental variables rather than of a genetic mechanism of natal dispersal. Perinatal conditions seemed to have significant effects on distances offspring dispersed, but increased natal dispersal had no apparent consequences on fitness.
Factors determining the severity of epidemics of Mycosphaerella graminicola (Septoria tritici) on winter wheat in the UK

Epidemics of disease caused by Septoria tritici were studied in detail in 11 crops of winter wheat cv. Longbow over 4 years. Serious damage to the uppermost two leaf layers was caused by splash-borne infection from lower in the crop early in the life of the leaves, followed by one or rarely two cycles of multiplication within a leaf layer. Infection conditions rarely limited damage, even in a dry year; the timing and, to a lesser extent, amount of initial inoculum movement to an upper leaf layer was of greater importance. Timing of initial infection was determined by when rain splash occurred in relation to emergence of a leaf layer. Occurrence of infections soon after a leaf layer started to emerge allowed more time for multiplication of disease within that layer. These infections tended to be more severe because the leaves were closer to inoculum sources within the crop. Slight differences in phenology between locations explain why initially random disease distributions sometimes become aggregated. Early-sown crops are at greater risk because they mature more slowly, allowing more disease multiplication and better transfer between leaf layers.
Strategies of bivalent formation in allopolyploid plants

Allopolyploids constitute a large proportion of flowering plant species. They are the product of natural or synthetic hybridization between related diploid species or genera, and therefore contain three or more sets of chromosomes which are structurally and genetically different. Many allopolyploids are highly fertile and show disomic inheritance, because chiasma formation at first metaphase of meiosis is restricted to homologous chromosomes only. Observations of synaptonemal complexes during meiotic prophase have shown that the diploidization of these species can be achieved in several ways depending upon the synaptic behaviour of chromosomes and the strict localization of chiasmata. These strategies of bivalent formation are described and compared in several allopolyploid species, with particular emphasis upon the relative importance of structural and genotypic components of the process.
Colonization of Inland Lakes in the Great Lakes Region by Rainbow Smelt, Osmerus mordax: Their Freshwater Niche and Effects on Indigenous Fishes

Rainbow smelt, Osmerus mordax, have colonized numerous inland lakes in eastern North America, primarily as a result of introductions by humans. Smelt often establish large populations in these lakes and influence indigenous fishes both directly (predation) and indirectly (competition). Smelt have a eurythermal life history, which results in spatial segregation of their larvae, juvenile, and adults, and are omnivorous feeders, eating a range of food types from zooplankton to fish. As a result, smelt interact strongly with a wide spectrum of prey and predator species. Effects on other species are mediated via food web interactions resulting in recruitment and growth changes in some species and redirection of energy flow and storage. Species most often affected are cold-water and cool-water species whose niches are most similar to juvenile and adult smelt. Increased growth rates of Atlantic salmon (Salmo salar) and lake trout (Salvelinus namaycush) and recruitment failure of lake whitefish (Coregonus clupeaf.
Functional genetic analysis of Arabidopsis thaliana SYNC1 in Lotus corniculatus super-growing roots using the FOX gene-hunting system

To analyze the function of SYNC1, an Arabidopsis asparaginyl-tRNA synthetase gene, the FOX-hunting system using super-growing roots (SR) from the legume species Lotus corniculatus was employed. One transformed line, FSL#121, was compared to parental SR and to an SR line harboring the empty vector (Control), all of which were grown in vivo using vermiculite pots. The level of several free amino acids was higher in FSL#121 than SR. Concomitantly, FSL#121 had a distinct phenotype of greater shoot length, stem diameter and shoot fresh weight compared with SR. Also, the root length, root diameter and fresh root weight were greater in FSL#121 than SR. Furthermore, the greater number of nodules in FSL#121 increased the nitrogen fixation activity per whole plant. Therefore, SYNC1 overexpression caused distinct changes in plant growth, increased the number of root nodules, and may be involved in increasing the amount of free amino acids, especially asparagine.
Environmental regulation of α-haemolysin expression in Escherichia coli

Abstract The effect of osmolarity, temperature and anaerobiosis on the expression of Escherichia coli α-haemolysin was investigated. Low osmolarity of the culture medium, growth at high temperature (37°C) and anaerobiosis increase haemolysin production in E. coli cells harbouring the haemolytic plasmid pHly152 as well as in haemolytic strains isolated from urinary-tract infections.
A comparison of bird communities in the anthropogenic and natural-tree fall gaps of a reduced-impact logged subtropical forest in Bolivia

Abstract We studied bird community composition and abundance within four vegetation and disturbance categories located within selectively logged and unlogged forest in a Bolivian subtropical lowland forestry concession. The logged forest was subject to reduced-impact logging between 1 and 4 years prior to our study. The four categories were: 1) ‘gap’ points possessing natural or anthropogenic tree-fall gaps; 2) ‘target’ points with one of five commercial tree species of harvestable size; 3) ‘future’ points possessing a commercial tree below harvestable size and 4) ‘non-target’ points not possessing harvestable tree species. The bird community composition of logging gaps significantly differed from that found within natural tree-fall gaps in the unlogged forest P< 0.05. Species richness was higher in natural tree-fall gaps than in anthropogenic gaps. Furthermore, a higher proportion of disturbance sensitive species were associated with natural-tree fall gaps, whereas a higher proportion of disturbance tolerant species were associated with anthropogenic gaps. No significant difference was detected in the bird community composition for the other three vegetation categories surveyed. We discuss the conservation and silvicultural repercussions of these results.
Modelo metacognitivo del estudiante para la generación de cursos personalizados

En muchos de los estudiantes se observa un marcado desconocimiento de los procesos cognitivos, afectivos y metacognitivos implicados en el aprendizaje significativo. En este trabajo se propone la utilizacion de un modelo metacognitivo del estudiante para conocer sus fortalezas y debilidades, por medio del cual se puede obtener un perfil metacognitivo que sirve como base para el diseno de cursos personalizados en sistemas de educacion basados en Internet. Se presentan los resultados obtenidos al aplicar este modelo en una escuela de nivel superior. El modelo propuesto esta respaldo por instrumentos que han comprobado su confiabilidad y son reconocidos y aceptados a nivel internacional. La intencion de esta investigacion es proponer una herramienta de facil aplicacion en las escuelas para mejorar el desempeno del estudiante al personalizar los contenidos educativos de los cursos en funcion del grado de desarrollo de sus habilidades metacognitivas. In many of the students a marked ignorance of their cognitive, affective and metacognitive processes involved in meaningful learning is observed. In this paper the use of a metacognitive student model is proposed to understand their strengths and weaknesses, through which you can get a metacognitive profile that serves as the basis for the design of custom courses in web-based education systems. The results of applying thismodel at a university are presented. The proposed model is support by instruments that have proven their reliability and are recognized andinternationally accepted. The purpose of this research is to propose a tool for easy implementation in schools toimprove student performance by personalizing the educational content of the courses in the degree of development of their metacognitive skills.
Scanning Electron Microscope Studies of Pollen of Cereals and other Grasses

Abstract Various authors disagree about the identification of cereal pollen based on phase contrast studies. Pollen of the common cereals and some wild grasses of a similar size range were examined with a scanning electron microscope. The pollen grains of Hordeum, Secale, Triticum monococcum, Agropyron, Ammophila, Elymus and Glyceria species have a scabrate sculpture of varying coarseness. The pollen of other Triticum species and Avena have an areolate sculpture.
EFFECT OF NITROGEN SUPPLY ON NITROGEN CONTENT AND GROWTH RATE OF JUVENILE MACROCYSTIS PYRIFERA (PHAEOPHYTA) SPOROPHYTES 1

The effect of nitrogen supply on nitrogen content and growth rate of juvenile Macrocystis pyrifera (L.) C. A. Agardh sporophytes was studied in two types of experiments: growth in continuously flowing mixtures of deep (nutrient‐rich) and surface (nutrient‐poor) seawater, and growth in batch cultures with alternate 7–10 day periods in deep and surface water. In the continuous flow experiments, the nitrogen content of the plants increased with the increased concentration of nitrate in the seawater. In the batch culture experiments, a lag period of 3–7 days often occurred before changes in the nitrogen supply were reflected in corresponding changes in the nitrogen content of the plants. Growth rates were a linear function of tissue nitrogen which varied between 1–3% dry weight. Saturation of growth rate as a function of tissue nitrogen did not occur, although tissue nitrogen levels did saturate as a function of external nitrate supply. Juvenile M. pyrifera sporophytes do not appear to “store” nitrogen. Total nitrogen varies from 1–6% dry weight in Laminariales and Fucales, but only some species of Laminaria appear to accumulate large pools of “surplus” nitrogen.