Miracle-dz/UniFAR-FTUs huggingface dataset:
Evolutionary Potential of (β/α)8-Barrels: In Vitro Enhancement of a “New” Reaction in the Enolase Superfamily†

The repertoire of reactions in the mechanistically diverse enolase superfamily is the result of divergent evolution that conserved enolization of a carboxylate anion substrate but allowed different overall reactions using different substrates. Details of the pathways for the natural evolutionary process are unknown, but the events reasonably involve (1) incremental increases in the level of the “new” reaction that would provide a selective advantage and (2) an accompanying loss of the “old” reaction catalyzed by the progenitor. In an effort to better understand the molecular processes of divergent evolution, the D297G mutant of the l-Ala-d/l-Glu epimerase (AEE) from Escherichia coli was designed so that it could bind the substrate for the o-succinylbenzoate synthase (OSBS) reaction and, as a result, catalyze that reaction [Schmidt, D. M. Z. , Mundorff, E. C. , Dojka, M. , Bermudez, E. , Ness, J. E. , Govindarajan, S. , Babbitt, P. C. , Minshull, J., and Gerlt, J. A. (2003) Biochemistry 42, 8387−8393]. The AEE pr.
Yield of common bean cultivars under semi‐arid conditions in eastern Ethiopia

In a 14-year period common bean cultivar Mexican-142 gave higher yields (2313 kg/ha) than Awash-1 (2042 kg/ha) and Brown speckled (2263 kg/ha). Seed yield was positively correlated with rainfall over the whole season and with rainfall in September, time of flowering and podding. Copyright © 2006 John Wiley & Sons, Ltd
Quality of plant products from organic agriculture

During the last decade, consumers' trust in food quality has decreased drastically, mainly because of growing ecological awareness and several food scandals (e.g. BSE, dioxins, bacterial contamination). It has been found that intensive conventional agriculture can introduce contaminants into the food chain. Consumers have started to look for safer and better controlled foods produced in more environmentally friendly, authentic and local systems. Organically produced foods are widely believed to satisfy the above demands, leading to lower environmental impacts and higher nutritive values. So far, studies have partly confirmed this opinion. Organic crops contain fewer nitrates, nitrites and pesticide residues but, as a rule, more dry matter, vitamin C, phenolic compounds, essential amino acids and total sugars than conventional crops. Organic crops also contain statistically more mineral compounds and usually have better sensory and long-term storage qualities. However, there are also some negatives: plants cultivated in organic systems generally have 20% lower yields than conventionally produced crops. Several important problems need to be addressed in the coming years: environmental, bacterial and fungal contamination of organic crops and, the most essential issue, the impact of organic food consumption on animal and human health. Copyright © 2007 Society of Chemical Industry
Intraguild interactions between the predator Macrolophus pygmaeus and the parasitoid Eretmocerus mundus, natural enemies of Bemisia tabaci

Abstract The native parasitoid Eretmocerus mundus Mercet and the predator Macrolophus pygmaeus Rambur are widely used to control Bemisia tabaci (Gennadius) in Mediterranean tomato greenhouses. An optimal biological control strategy for B. tabaci should take into account intraguild interactions between these natural enemies. In this study, predator's prey preferences and prey consumption were studied when offered different parasitoid and whitefly stages. The effect of the host plant on the adults of both natural enemies was also examined. M. pygmaeus preferred to consume B. tabaci over E. mundus when immature stages and adults of B. tabaci and E. mundus were offered. They consumed a larger amount of healthy B. tabaci nymphs and adults than of parasitised nymphs or E. mundus adults. The predator M. pygmaeus interfered with the reproduction of E. mundus females on cotton but not on tomato. However, B. tabaci nymphal mortality on tomato associated with parasitoid host feeding was also lower when the adult parasitoids coexisted with the predators. The joint release of M. pygmaeus and E. mundus adults did not increase the control of the whitefly B. tabaci.
Long-Term Monitoring of Endangered Laysan Ducks: Index Validation and Population Estimates 1998–2012

Abstract Monitoring endangered wildlife is essential to assessing management or recovery objectives and learning about population status. We tested assumptions of a population index for endangered Laysan duck (or teal; Anas laysanensis) monitored using mark–resight methods on Laysan Island, Hawai'i. We marked 723 Laysan ducks between 1998 and 2009 and identified seasonal surveys through 2012 that met accuracy and precision criteria for estimating population abundance. Our results provide a 15-y time series of seasonal population estimates at Laysan Island. We found differences in detection among seasons and how observed counts related to population estimates. The highest counts and the strongest relationship between count and population estimates occurred in autumn (September–November). The best autumn surveys yielded population abundance estimates that ranged from 674 (95% CI = 619–730) in 2003 to 339 (95% CI = 265–413) in 2012. A population decline of 42% was observed between 2010 and 2012 after consecu.
Altitudinal decline of body size in a Tibetan frog

Geographic variation in mean body size along latitudinal and altitudinal gradients is a commonplace occurrence, but little is known about the relative importance of different factors underlying this clinal variation in ectothermic animals. We investigated altitudinal variation in mean body size, age and growth rate in Nanorana parkeri, a ranid exhibiting the highest altitudinal distribution range on the Tibetan plateau. Data collected from six populations covering an altitudinal span of 3800–4700 m showed that the mean body size declined with increasing altitude, and hence, the data conformed to converse Bergmann's rule. Frogs from high-altitude populations exhibited delayed metamorphosis and sexual maturity and had greater average age but lower growth rate than frogs from low-altitude populations. Thus, the proximate reason for the altitudinal decline in mean body size – despite of increased average age towards high altitudes – is likely be the reduction of growth rate at high-altitude localities. We discuss the possibility that physiological advantages provided by small body and egg size could be adaptive in the extreme high-altitude environments characterized by low oxygen supply.
Desempenho de frangos de corte alimentados com diferentes níveis de farelo de canola

The objective of this experiment was to determine the best level of substitution of soybean meal by canola meal in rations for broilers. Five levels of substitution of soybean meal by canola meal were compared: 0, 10, 20, 30, and 40%. Twelve hundred one-day Ross chicks were used, grouped by sex and weight. Animals were fed rations with 22% of crude protein and 3000kcal ME/kg from 0 to 21 days, 20% of crude protein and 3100kcal ME/kg from 22 to 35 days, and 18% of crude protein and 3150 kcal ME/kg from 36 to 42 days. Feed consumption was reduced from 0 to 21 days and from 36 to 42 days when higher amounts of canola meal were used in the diets. A reduction in weight gain of the broilers was observed only from 0 to 21 days. Feed conversion was improved from 0 to 21 days and from 22 to 35 days. Canola meal can participate in diets for broilers from 22 to 42 days of age in quantities up to 40% of the amount of the soybean meal used.
Histopathological findings after sea bass (Dicentrarhus labrax L.) exposure to extracellular products of Photobacterium damsela subsp. piscicida produced in vivo

Groups of sea bass (Dicentrarhus labrax L.) were surgically implanted in the abdominal cavity with dialysis tubing of different pore size containing either live Photobacterium damsela subsp. piscicida cells or sterile phosphate-buffered saline, in order to grow the pathogen in vivo. During the course of the experiment mortalities, not due to microbial infection, occurred, that prompted the use of histology in order to identify the lesions caused by molecules released from the dialysis bags during in vivo growth of the pathogen. Collected tissues from moribund fish were processed for light microscopy. Fish implanted with the 2 kD molecular weight cut-off (MWCO) bags suffered very minor histological changes whereas fish with 12 kD MWCO membranes showed severe lesions varying upon the time post operation. Moreover, inflammatory cells appeared in all tissues from fish implanted with 12 kD MWCO especially 48 h after infection. Spleen, liver, intestine and gills showed necrotic changes appearing 60 h post infection. Since no bacteria were isolated after microbiological sampling of tissue, the inflammatory-necrotic changes observed in the tissues were attributed to the toxicity of extracellular products.
Inhibitory Effect of Sulfides on Browning of Apple Slice

ネギ属の野菜を切ったり磨砕したりする時に生成するスルフィド類がリンゴ切片の褐変に及ぼす影響を調べた. 500mlのポリプロピレン袋に新鮮なリンゴ切片と10μlのジメチルトリスルフィドを入れておくとリンゴ切片は褐変せず, また, すでに褐変したリンゴ切片の色を白色化した. リンゴ切片とジメチルトリスルフィドを一緒に包装しておくとメタンチオールが生成し, そのメタンチオールによって褐変が抑制されることを見出した. ジメチルジスルフィドの場合は褐変を中程度に抑制し, 少しづつメタンチオールを生成した. 一方, ジメチルスルフィドはリンゴ切片の褐変を抑制せず, メタンチオールも生成しなかった. これらの結果から, トリスルフィド, ジスルフィドによるリンゴ切片の褐変抑制は, 大部分がリンゴとこれらのスルフィドから生成するメタンチオールの作用であり, モノスルフィドはメタンチオール生成の基質となり得ないと考えられた.
Development of colon‐targeted albendazole‐β‐cyclodextrin‐complex drug delivery systems

Albendazole, a drug for the treatment of gastrointestinal nematode infection, is variably and erratically absorbed from the gastrointestinal tract after oral administration. The present study was aimed at developing matrix tablets of albendazole using guar gum as carrier for colon targeting in order to provide an effective and safe therapy for helminthiasis. To improve its bioavailability, the formation of inclusion complexes of albendazole with β‐cyclodextrins was investigated. Matrix tablets of albendazole–β‐cyclodextrin complex were prepared by the wet granulation method using guar gum as matrix carrier in various proportions: 20% (SAC‐20), 30% (SAC‐30), and 40% (SAC‐40). A high‐performance liquid chromatography–ultraviolet method was developed to quantitate albendazole using mebendazole as internal standard at 254 nm. The granules were compressed using 12‐mm round, flat, and plain punches. Tablets were evaluated for various physical characteristics such as thickness, hardness, and drug content uniformity. The matrix tablets were subjected to in vitro drug release studies in 0.1 N HCl (2 h), pH 7.4 Sorensen's phosphate buffer (3 h) and simulated colonic fluids. The SAC‐30 released 67.7±1.9% of albendazole in the presence of rat caecal contents, whereas in the control study the formulation released only 29.7±0.2% of albendazole. A significant difference (P<0.001) was observed at 24 h in the amount of albendazole released from SAC‐30 when compared to the dissolution study without rat caecal contents. The study shows that the release of albendazole in the physiological environment of colon is due to the microbial degradation of guar gum compression‐coated tablets in the presence of rat caecal contents. Stability studies were carried out at 40°C/75% relative humidity for 6 months to assess their long‐term (2 years) stability. No change either in their physical appearance or in drug content was observed. Drug Dev. Res. 65:76–83, 2005. © 2005 Wiley‐Liss, Inc.
Dark energy in five-dimensional Brans-Dicke cosmology with dimensional reduction

We explore a 5D Brans-Dicke scalar cosmology by conjecturing that the four-dimensional Hubble parameter varies as H = eφ s , e ∈ R and s is some unknown power index and that the extra-dimensions compactify as the visible dimensions expand as b(t) ≈ ax (t) , x ∈ R − . We mainly discuss the case x = −1. For critical values of e close to unity, it was observed that the acceleration of the universe occurs at redshift close to z = 0.8 which indicates that in our model, accelerated expansion of the universe began only recently. Several interesting points are revealed and discussed in some detail.
Theoretical Aspects of Cursorial Adaptations in Dinosaurs

A theoretical review of the physical constraints on cursorial animals provides a list of the morphological correlates of superior running ability, with emphasis on osteological features. This list includes the following adaptations: relatively long limbs; small forelimbs (bipeds only); freely rotating scapula (quadrupeds only); hinge-like joints; short and massive proximal limb elements; long and slender distal limb elements; radius-ulna and tibia-fibula which are reduced to single elements; manus and pes with pronounced median symmetery; digitigrade to unguligrade stance; interlocked or fused metapodials; reduced or lost inner and outer digits, and snap ligaments sometimes present. These adaptations are ubiquitous among phylogenetically diverse animals which run and may be regarded as inevitable in any cursor. Theoretical arguments predict a lower speed potential for very large and very small animals, and this conclusion is supported by empirical data which point to an optimum body mass of about 50 kg for a cursor. By utilizing these findings and a system of four levels of running ability (graviportal, mediportal, subcursorial, cursorial), it is possible to evaluate the running potential of dinosaurs. Quadrupedal dinosaurs had fewer cursorial features than bipeds, and large bipeds had fewer than small bipeds. Sauropods and stegosaurs were graviportal; ankylosaurs and large ceratopsians were low to intermediate grade mediportal; prosauropods were high-grade mediportal; large ornithopods were subcursorial; and large theropods were subcursorial to cursorial. Small ceratopsians were dynamic bipeds and were high-grade subcursorial. Small bipedal ornithischians and small theropods were cursorial and were the fastest of the dinosaurs, but were probably not as fast as the best modern runners.
Hybrids in Marsupial Research

Many species from the superfamily Macropodoidea hybridise in captivity despite chromosomal and/or morphological differences. Details of such hybrids were collected from the literature or by personal communications from researchers or breeders of macropods. A Table of known hybrids and notes on their fertilities is presented, which includes the chromosome numbers and differences in gross and C-banded karyotypes of each parental species. Also included in the table are the numbers of proteins known to differ in electrophoretic mobility between each pair of parental species, and the number of proteins which are polymorphic in either of the two parental species. This table, therefore, can be used in gene mapping studies for assessing which hybrids carry suitable chromosomal and genetic markers and might be fertile. Four different interspecific crosses have already been reported as fertile, and artificial methods of increasing fertility could increase the likelihood of producing fertile hybrids. Moreover, the variety of hybrids and their different degrees of fertility show that they are potentially valuable for studying the effects of genic and chromosomal heterozygosity on growth and development, meiotic processes and spermatogenesis.
Kernel Number Determination in Maize

Maize (Zea mays L.) grain yield is closely associated with kernel number at harvest. This yield component is a function of the physiological condition of the crop at a critical period bracketing silking. The objectives of this study were to analyze for that critical period by assessing (i) the relationship between final kernel number and plant or crop growth rate, (ii) the partitioning of dry matter to reproductive structures, and (iii) the effect of duration of this period on kernel set. Kernel number (per plant and per unit area) and growth rates of crops, plants, and ears were measured in 12 field experiments conducted at Balcarce, Argentina, from 1989 to 1996 with hybrid Dekalb 636. Experimental sources of variation included shading, plant density, sowing date, and night temperature. Shading and night temperature treatments were established during a 31-d period bracketing silking. In one of the density experiments, plant growth rate was estimated for individual plants by means of a non-destructive methodology based on correlations between dry matter and morphometric measurements. The relationship between kernel number per plant and plant growth rate was curvilinear with threshold values of approximately 1 g d⁻¹ for kernel set and 6 g d⁻¹ for prolificacy. At high and at low plant growth rates during the period bracketing silking, Dekalb 636 set a low number of kernels per unit of plant growth rate. This effect was explained by limited partitioning of biomass to reproductive structures during that period. When duration of the critical period for kernel set was considered by expressing plant growth rate in thermal units, a better estimation of kernel number per plant was obtained. This work was supported by Instituto Nacional de Tecnologia Agropecuaria (INTA); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET); Facultad de Ciencias Agrarias Univ. Nac. de Mar del Plata; Fundacion Antorchas; and Dekalb Argentina S.A. C. Vega held a scholarship from CIC (Comision de Investigaciones Cientificas de la Provincia de Buenos Aires)
Differences between symmetric and asymmetric facilitation matter: exploring the interplay between modes of positive and negative plant interactions

Facilitation (positive interaction) has received increasing attention in plant ecology over the last decade. Just as for competition, distinguishing different modes of facilitation (mutualistic, commensal or even antagonistic) may be crucial. We therefore introduce the new concept of symmetric versus asymmetric facilitation and present a generic individual‐based zone‐of‐influence model. The model simultaneously implements different modes of both facilitation and competition among individual plants via their overlapping zone of influence. Because we consider facilitation modes as a continuum related to environmental context, we integrated this concept with the stress‐gradient hypothesis (SGH) by exploring differences in spatial pattern formation in self‐thinning plants along a stress gradient in our model. The interplay among modes of interaction creates distinctly varied spatial patterns along stress gradients. When competition was symmetric, symmetric facilitation (mutualism) consistently led to plant aggregation along stress gradients. However, asymmetric facilitation (commensalism) produces plant aggregation only under more benign conditions but tends to intensify local competition and spatial segregation when conditions are harsh. When competition was completely asymmetric, different modes of facilitation contributed little to spatial aggregation. Symmetric facilitation significantly increased survival at the severe end of the stress gradient, which supports the claim of the SGH that facilitation should have generally positive net effects on plants under high stress levels. Asymmetric facilitation, however, was found to increase survival only under intermediate stress conditions, which contradicts the current predictions of the SGH. Synthesis. Our modelling study demonstrates that the interplay between modes of facilitation and competition affects different aspects of plant populations and communities, implying context‐dependent outcomes and consequences. The explicit consideration of the modes and mechanisms of interactions (both facilitation and competition) and the nature of stress factors will help to extend the framework of the SGH and foster research on facilitation in plant ecology.
The population dynamics of plants

Long-term studies of plant populations are reviewed, and their dynamics summarized in three categories. Many short-lived plants have ephemeral, pulsed dynamics lasting only a single generation, with recruitment determined almost entirely by germination biology and by the frequency and intensity of disturbance. Such populations are not amenable to traditional population models. At the other extreme, some long-lived plants have such protracted tenancy of their microsites that it is impossible to establish what pattern of dynamics (if any) their populations exhibit. A relatively small number of species show what we would traditionally regard as population dynamics at a given point in space (i.e. reasonably predictable trajectories that can be modelled by N t+1 = f ( N t )). A major difficulty in generalizing about plant dynamics is that the majority of species are successional; their recruitment depends upon the death, through senescence or disturbance, of the dominant plants. Where we do have data spanning several generations, it is clear that: (i) the populations are regulated by density dependent processes; (ii) in contrast to some animal populations, numbers appear to vary less from year to year in places where mean density is higher, and less from place to place in years when mean density is high than when density is low; (iii) few, if any, plant populations show persistent cyclic or chaotic dynamics, but (iv) there are several robust generalizations that stem from the immobility and phenotypic plasticity of plants (the law of constant yield; self-thinning rules, etc.). These generalizations are analysed in the context of simple theoretical models of plant dynamics, and the patterns observed in long-term studies are compared with similar data from animal populations. Two important shortcomings of traditional plant demography are emphasized; (i) the dearth of simple manipulative experiments on such issues as seed limitation, and (ii) the tendency to locate study plots around existing mature individuals (the omission of ‘empty quadrats’ may introduce serious bias into the estimation of plant recruitment rates).