Miracle-dz/UniFAR-FTUs huggingface dataset:
Consequences of Wheat Breeding on Nitrogen and Phosphorus Yield, Grain Nitrogen and Phosphorus Concentration and Associated Traits

Abstract Several studies have analysed the effects of wheat breeding on dry matter accumulation and partitioning, but little has been done to understand the effects on nutrient economies. The objective of this study was to identify the changes produced by wheat breeding in the economy of nitrogen and phosphorus under field conditions. Two experiments were carried out with seven genotypes (including a commercial hybrid) representing different eras of plant breeding. Wheat breeding has increased grain nitrogen and phosphorus yield but total absorbed nutrients have not shown any trend during this century. The main attribute closely related to the increase in grain nitrogen and phosphorus yields was their harvest indices. The higher nutrient partitioning in the newer cultivars was associated with lower grain nitrogen and phosphorus concentrations in their grains. Therefore, there was a negative effect of genetic improvement in grain nitrogen and phosphorus concentrations. The main cause for the decreased concentration of these nutrients in the grains of the modern cultivars appeared to be a dilution by an even more increased dry matter partitioning. It is suggested that future breeding should be aimed to select for higher nitrogen uptake as a way to increase the level of this nutrient in grain.
Regulation Mechanisms of Stomatal Oscillation

Abstract: Stomata function as the gates between the plant and the atmospheric environment. Stomatal movement, including stomatal opening and closing, controls CO2 absorption as the raw material for photosynthesis and water loss through transpiration. How to reduce water loss and maintain enough CO2 absorption has been an interesting research topic for some time. Simple stomatal opening may elevate CO2 absorption, but, in the meantime, promote the water loss, whereas simple closing of stomatal pores may reduce both water loss and CO2 absorption, resulting in impairment of plant photosynthesis. Both processes are not economical to the plant. As a special rhythmic stomatal movement that usually occurs at smaller stomatal apertures, stomatal oscillation can keep CO2 absorption at a sufficient level and reduce water loss at the same time, suggesting a potential improvement in water use efficiency. Stomatal oscillation is usually found after a sudden change in one environmental factor in relatively constant environments. Many environmental stimuli can induce stomatal oscillation. It appears that, at the physiological level, feedback controls are involved in stomatal oscillation. At the cellular level, possibly two different patterns exist: (i) a quicker responsive pattern; and (ii) a slower response. Both involve water potential changes and water channel regulation, but the mechanisms of regulation of the two patterns are different. Some evidence suggests that the regulation of water channels may play a vital and primary role in stomatal oscillation. The present review summarizes studies on stomatal oscillation and concludes with some discussion regarding the mechanisms of regulation of stomatal oscillation. (Managing editor: Wei WANG)
Temporal changes in release rates and quality of lobster (Homarus americanus) feeding attractants from herring (Clupea hareng us) baits

Primary amine release rates of various herring preparations (frozen, fresh, and 20% salt) were determined over a 45h period in order to evaluate characteristic chemical‐release profiles of baits for lobsters (Homarus americanus). Over the first 5.5h, salted herring had high but declining amine release rates. A similar, less pronounced pattern of amine release was observed for frozen herring while that of fresh herring remained stable and low. After 12h, the release rates of all preparations were equivalent and low. A behavioral bioassay of post‐larval lobsters was used to determine the level of directed food‐search response to frozen and salted herring leachates collected over the 45h period and adjusted to equimolar amine concentrations. No differences in attractiveness among the two bait types were observed at any one time of leaching. Attractants were confined to polar, primary amine containing fractions. There was, however, a decrease in response to the leachates with time suggesting that decay advers.
Antimutagenic Polyphenols in African Foods

Abstract The major problem with cancer is the ability of cancer cells to infiltrate surrounding tissue (invasion) or to spread to distant organs (metastasis), thereby decreasing the patient’s survival. One of the first steps in the process of metastasis is local spreading or invasion from the primary tumour and certain Ca2+ -binding proteins of the S100 family eg, S100A4 and S100P, can induce a metastatic phenotype and enhance cell migration and invasion. Both S100A4 and S100P are expressed at elevated levels in several forms of cancer including breast, pancreatic, prostate, colon, ovary, oesophagus and lung cancer. Initially, we introduced a series of deletion mutants on the S100A4 protein by truncation of the C-terminal region. The S100A4 open-reading-frame cloned into an expression vector was subjected to site-directed mutagenesis to create the mutations, either by deletion or by substitution. These mutant proteins, when expressed in cells, conferred reduced metastasis, invasion and migration-inducing .
Why are there no Viviparous Birds?

The absence of viviparity in birds is typically explained by invoking morphological or physiological factors putatively incompatible with live-bearing reproduction. Examining these factors in terms of falsifiable predictions and underlying assumptions, we suggest that no single avian feature is known to be inherently incompatible with viviparous production of small clutches and that the absence of the live-bearing mode is a consequence of the lack of selection for the intermediate evolutionary stage of egg retention. Birds have achieved most of the advantages that potentially could accrue from egg retention and viviparity by such specializations as endothermy, egg incubation, nest construction, uricotelism, shell pigmentation, parental care, altricial hatchlings, albumen provision, and calcareous eggshells. A theoretical model is presented in support of our contention that the costs of egg retention associated with decreased fecundity, increased maternal mortality, and decreased paternal investment outweigh the potential benefits for most birds.
Dicing with death: predator inspection behaviour in minnow shoals

When shoaling minnows encounter a stalking pike, fish leave the shoal, approach the potential predator and then usually halt briefly before returning to the group. This behaviour, termed predator inspection, has been reported from encounters with both real and model pike. A description of inspection behaviour is given using data from experiments with a model pike made to approach foraging minnows with a standardised stalk. Evidence is presented that inspecting fish assess the risks involved. Individual minnows which have carried out an inspection visit to the predator model exhibit changes in behaviour on return which are contingent upon the state of the model, demonstrating that information is gained. Other fish change their behaviour after an inspector returns to the group, suggesting that information about the threat is transferred among the shoal. Possible costs of predator inspection behaviour may balance these benefits of knowledge, but require further investigation.
Can herbivore‐induced plant volatiles inform predatory insect about the most suitable stage of its prey?

The leaf beetle Plagiodera versicolora (Coleoptera: Chrysomelidae) is a specialist herbivore, all of whose mobile stages feed on the leaves of salicaceous plants. Both the larval and adult stages of the ladybird Aiolocaria hexaspilota (Coleoptera: Coccinellidae) are dominant natural enemies of the larvae of the leaf beetle. To clarify the role of plant volatiles in prey‐finding behaviour of A. hexaspilota, the olfactory responses of the ladybird in a Y‐tube olfactometer are studied. The ladybird adults show no preference for willow plants Salix eriocarpa that are infested by leaf beetle adults (nonprey) over that for intact plants but move more to the willow plants infested by leaf beetle larvae (prey) than to intact plants. Moreover, ladybird larvae show no preference for willow plants infested by leaf beetle larvae or adults over intact plants. Using gas chromatography‐mass spectrometry, six volatile compounds are released in larger amounts in the headspace of willow plants infested by leaf beetle larvae than in the headspace of willow plants infested by leaf beetle adults. In addition, the total amount of volatiles emitted from willow plants that are either intact or infested by leaf beetle adults is much smaller than that from willow plants infested by leaf beetle larvae. These results indicate that volatiles from S. eriocarpa infested by P. versicolora inform A. hexaspilota adults about the presence of the most suitable stage of their prey, whereas A. hexaspilota larvae do not use such information.
Uso de imagens de radar para o cálculo da produção primária de plantas aquáticas nas várzeas da Amazônia

A area da planicie de inundacao da Amazonia e estimada em 300 000km2 e sua produtividade primaria em 1,17 x 1014 g C yr-1. Deste total de area e produtividade, estimativas sugerem que 43% e 62%, respectivamente, sao atribuidos as plantas aquaticas. Estas estimativas variam de acordo com o pulso de inundacao. Por exemplo, durante o periodo de seca as plantas terrestres (herbaceas) geralmente ocupam areas que apresentam plantas aquaticas na cheia. A area e a produtividade destes ecossistemas sao informacoes essenciais para a compreensao da dinâmica biogeoquimica da Amazonia. Imagens de satelites (radar) combinadas com amostragem de campo foram utilizadas para estimar a biomassa e mapear a area de cobertura de plantas aquaticas emergentes para calcular a producao primaria de plantas aquaticas na varzea do baixo Amazonas. A combinacao de bandas C e L forneceu a melhor correlacao (r=0,82) e um ponto de saturacao de biomassa intermediario (620 gm-2) para estimar biomassa aerea. O metodo de segmentacao e classificacao por regiao foi utilizado para classificar combinacoes de bandas C e L para cada periodo de nivel de agua, e forneceu uma precisao de mapeamento maior que 95% para determinacao espacial de areas cobertas por plantas aquaticas. Combinando a distribuicao espacial de plantas aquaticas, o modelo para estimativa de biomassa aerea e a porcentagem de biomassa submersa, estimou-se espacialmente uma producao primaria liquida anual de 1.9x1012 g C yr-1 (±28%) para as plantas aquaticas em uma area de 394km2.
Influence des conditions de culture préalables et de la présence du gène rpoS pour la survie de Salmonella typhimurium en eau de mer exposée à la lumière solaire

The effect of sunlight exposure on Salmonella typhimurium isogenic strains harboring an rpoS gene functional (rpoS+) or not functional (rpoS) was investigated in microcosms of sterile sea water at 20 °C. The two strains rapidly lost their ability to produce colonies on solid culture media. The detrimental action of sunlight was more important when the salinity of sea water increased. The survival of stationary phase cells was influenced by RpoS. Bacteria grown in media with high salinity or osmolarity and transferred to sea water in stationary phase were more resistant to irradiation than those grown in media with low salinity. Prior growth under oxidative (0.2 mmol/L of H2O2) or amino acid starved (minimal medium) conditions did not modify the survival of either strain when they were exposed to sunlight. Bacteria were more resistant when cells were incubated in sea water in the dark prior to being exposed to sunlight. The resistance to sunlight irradiation was also greater in clones of both strains isol.
Defence, growth and nutrient allocation in the tropical shrub Bauhinia brevipes (Leguminosae)

Herbivory in natural communities can be high, reducing the growth and reproduction of individual plants. To diminish the impact of herbivores, plants use a variety of defensive mechanisms. It is now recognized that the plant world is characterized by a proliferation of secondary metabolites, but models of the evolution of defence strategies assume that plants are constrained by finite resources, and that defences are costly. In the pre- sent study, the relationships between defence, growth and nutrient concentration in Bauhinia brevipes Vog. (Leguminosae) in south-eastern Brazil were investigated. Patterns of herbivory and defence were examined for 170 B. brevipes individuals in 1997 and 1998. Leaf age influenced tannin concentration and herbivore attack on B. brevipes. Mature leaves had higher concentrations of tannins than young leaves, and young leaves were approxi- mately 60% more likely to be attacked than mature leaves. Carbon and nitrogen content explained 36% of the variation in the percentage of attacked leaves in B. brevipes (y = 16.29 - 0.31 C + 0.25 N; r 2 = 0.36; F = 9.56; P < 0.0001). Tannins acted as defensive compounds on B. brevipes leaves against free-feeding herbivores, but no clear pattern was observed against galling herbivores. The amounts of nitrogen, carbon, potassium, and aluminium explained approximately 69% of the variation in tannin concentration on B. brevipes leaves (y = 0.62 - 0.16 N - 0.36 K - 0.26 Al + 0.74 C; r 2 = 0.69; F = 21.18; P < 0.0001). We found an inverse relationship between shoot growth rates and tannin concentration in B. brevipes, indicating that the production of tannins may be costly, therefore offering some evidence for the trade-off hypothesis. Nevertheless, the weak relationship observed between herbi- vore damage and tannin concentration indicates that other factors are also involved with herbivore pressure.
Hardening, abscisic acid, proline and freezing resistance in two winter wheat varieties

Two varieties of winter wheat (Triticum aestivum L.) differing in freezing resistance (“Holme” from Sweden, freezing resistant, and “Amandus” from Germany, less freezing resistant) were hardened for five weeks by gradually reducing the day/night temperature from 20°C/15°C during the first week to 2° C/0° C during the fifth week and the photoperiod from 15 to 9 h. This treatment increased the freezing resistance of both varieties in comparison to unhardened control plants. Hardening caused an increase in osmolarity of cell sap and in the levels of proline and abscisic acid (ABA). Increase in osmolarity preceded the increase in ABA level, and proline levels increased later than ABA levels. Holme had higher values of osmolarity as well as higher levels of ABA and proline. but the differences between the two varieties were significant only for proline. Since the pressure potential remained constant or increased slightly during the hardening period, it is suggested that the accumulation of ABA is due to the hardening process and not to simple water stress caused by cold-induced inhibition of water uptake by the root. Spraying hardened plants with 10−4 M ABA 24 h before a freezing test increased freezing resistance in both varieties, but did not obliterate the differences in freezing resistance between the two varieties. Spraying hardened plants with an aqueous proline solution (10%, w/v) was without effect on freezing resistance. It is concluded that the hardening procedure causes an accumulation of ABA in winter wheat leaves and that ABA is involved in the chain of events leading to freezing resistance.
Enzyme thermostabilization by bovine serum albumin and other proteins: evidence for hydrophobic interactions

BSA stabilizes Streptococcus thermophilus beta‐galactosidase against thermal inactivation and binds to the active enzyme subunits formed on heating. The mechanism of interaction and stabilization, however, is unknown, and it was investigated using different proteins. The results show that several proteins increased the enzyme half‐life (t 1/2) at 64 degrees C in the presence of the substrate lactose. The best stabilizers were BSA (9‐fold) and casein (6‐fold). There was a significant correlation between enzyme half‐life (t 1/2) and surface hydrophobicity of the proteins (So), of the form t 1/2 varies; is directly proportional to S0.5o. The surface hydrophobicity of the enzyme increased upon heating, while that of BSA declined. Heating enzyme and BSA together caused a net loss in surface hydrophobicity, indicating hydrophobic interactions, but there was no change in the absence of heating. Stabilization of the enzyme by BSA was markedly affected by chaotropic and kosmotropic salts. Stabilization was increased by 1 M Na2SO4 and reduced by 1 M NaBr; 1 M NaCl had little effect. None of the three salts increased the stability of the enzyme itself, indicating that the effect was on the enzyme‐protein interaction. The results indicate that BSA stabilized the enzyme by hydrophobic interactions with the heated enzyme and that surface hydrophobicity is a major determinant of the extent of stabilization by a protein.
Pyruvate dehydrogenase complex and acetyl-CoA carboxylase in pea root plastids: their characterization and role in modulating glycolytic carbon flow to fatty acid biosynthesis

The pyruvate dehydrogenase complex (PDC) and acetyl-CoA carboxylase (ACC, EC 6.4.1.2) have been characterized in pea root plastids. PDC activity was optimum in the presence of 1.0 mM pyruvate, 1.5 mM NAD + , 0.1 mM CoA, 0.1 mM TPP, 5 mM MgCI2, 3.0 mM cysteine-HCI, and 0.1 M Tricine (pH 8.0) and represents approximately 47% of the total cellular activity. ACC activity was greatest in the presence of 1.0 mM acetyl-CoA, 4 mM NaHC03, 3 mM ATP, 10 mM MgCI2, 2.5 mM dithiothreito l, and 100 mM Tricine (pH 8.0). Both enzymes were stimulated by reduced sutphydryl reagents and inhibited by sulphydryl inhibitors. ACC was also inhibited by malonyl-CoA while PDC was inhibited by both malonyl-CoA and NADH. Both enzymes were stimulated by DHAP and UDP-galactose while ACC was also stimulated by PEP and F1,6P. Palmitic acid and oleic acid both inhibited ACC, but had essentially no effect on PDC. Palmitoyl-CoA inhibited both enzymes while PA and Lyso-PA inhibited PDC, but stimulated ACC. The results presented support the hypothesis that PDC and ACC function in a co-ordinated fashion to promote glycolytic carbon flow to fatty acid biosynthesis in pea root plastids.
The Latitudinal Gradient in Geographical Range: How so Many Species Coexist in the Tropics

The latitudinal gradient in species richness is paralleled by a latitudinal gradient in geographical-range size called Rapoport's rule. It is suggested that the greater annual range of climatic conditions to which individuals in high-latitude environments are exposed relative to what low-latitude organisms face has favored the evolution of broad climatic tolerances in high-latitude species. This broad tolerance of individuals from high latitudes has led to wider latitudinal extent in the geographical range of high-latitude species than of lower-latitude species. The existence of Rapoport's rule suggests yet another way of looking at the latitudinal gradient in species richness. If low-latitude species typically have narrower environmental tolerances than high-latitude species, then equal dispersal abilities in the two groups would place more tropical organisms out of their preferred habitat than higher-latitude species out of their preferred habitat. It is hypothesized that a larger number of "accidentals" (i.e., species that are poorly suited for the habitat) occur in tropical assemblages. The constant input of these accidentals artificially inflates species numbers and inhibits competitive exclusion.
Protein Identification and Quantification by Mass Spectrometry-Based Analysis: Applications in Plant-Pathogen Interactions Studies

Mass spectrometry (MS) has become an essential technology for proteomics applications in biological sciences. Advances in this technique have been possible owing to improvements in MS instrumentation, new experimental strategies in sample preparation, and development of bioinformatics tools for data analyses. In recent years, complementary strategies to the classical two-dimensional gel electrophoresis approaches (2-DE) have been developed. These techniques are based on multidimensional peptide separation coupled to tandem MS (also referred as “second generation proteomics”), enabling protein expression analysis and high throughput protein identification studies. New methods such as Multidimensional Protein Identification Technology (MudPIT) and stable isotope labeling of protein/peptide samples (either by chemical, metabolic, or enzymatic methods), among others, are powerful tools for large-scale studies on characterization and expression of proteins in complex biological systems. Hence, these techniques can be very useful in the study of plant-pathogen interactions, aiding to detect and characterize both plant proteins concerned in defense reactions and pathogen proteins involved in pathogenicity and/or virulence. But these techniques have been implemented in these biological systems just recently. We will examine here how MS-based proteomics approaches are helping to better understand the multifaceted phenomena underlying plant-pathogen interactions.
Fishery Responses to Habitat Restoration in Lake Tohopekaliga, Florida

Abstract During the 1987 drawdown of Lake Tohopekaliga, 19 km of degraded littoral zone were restored when approximately 165,000 m3 of sediments were removed. Electrofishing data from 1988 and 1989 indicated median catch per effort for largemouth bass Micropterus salmoides, redear sunfish Lepomis microlophus, and forage fish was significantly greater in restored sites than in nonrestored sites. Median catch-per-effort values in restored sites also were higher for bluegill Lepomis macrochirus, but the differences were statistically significant only in 1988. Sampling in shallow water with Wegener rings in 1988 indicated that age-0 largemouth bass and other sport fish were more abundant in restored sites than control sites. Sport fish reproduction was reduced in restored sites during 1989 and could not be detected in control sites. We conclude that in Lake Tohopekaliga, an extreme drawdown coupled with mechanical removal of organic sediments from the littoral zone provided an immediate positive fisheries res.
Examining the factors influencing leaf disease intensity of Kalopanax septemlobus (Thunb. ex Murray) Koidzumi (Araliaceae) over multiple spatial scales: from the individual, forest stand, to the regions in the Japanese Archipelago

We investigated leaf disease intensity of Kalopanax septemlobus (prickly castor oil tree) caused by the parasitic fungus Mycosphaerella acanthopanacis, in thirty natural host populations in the Japanese Archipelago. The disease intensity observed for individual trees were analyzed using a generalized additive model as a function of tree size, tree density, climatic terms and spatial trend surface. Individual tree size and conspecific tree density were shown to have significant negative and positive effects on disease intensity, respectively. The findings suggest that the probability of disease infection is partly determined by dispersal of infection agents (ascospores) from the fallen leaves on the ground, which can be enhanced by aggregation of host trees in a forest stand. Regional-scale spatial bias was also present in disease intensity; the populations in northern Japan and southern Kyushu were more severely infected by the fungus than those in southwestern Honshu and Shikoku. Regional variation of disease intensity was explained by both climatic factors and a trend surface term, with a latitudinal cline detected, which increases towards the north. Further research should be conducted in order to understand all of the factors generating the latitudinal cline detected in this study.