917 research outputs found

    Mimicry and ultrastructural analogy between the semi-aquatic grasshopper Paulinia acuminata (Orthoptera: Pauliniidae) and its foodplant, the water-fern Salvinia auriculata (Filicatae: Salviniaceae)

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    The semi-aquatic grasshopper Paulinia acuminata is mimetically protected by a striking similarity to its foodplant, the floating fern Salvinia auriculata. A SEM study of the cuticula of young grasshopper nymphs and the Salvinia leaf surface reveals a similar ultrastructure of epicuticular waxes which makes both organisms extremely water repellent

    Conservative treatment of an acute compartment syndrome of the thigh

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    Compartment syndromes of the thigh after blunt trauma without any fracture are rare. Most surgeons recommend operative treatment. There are different rules for compartment syndromes of the thigh in young athletes after blunt trauma compared to compartment syndromes at other locations [(1) the large volume of the quadriceps muscle, (2) its relatively elastic fascia, (3) the direct proximal contact to the hip muscles which allows extravasation of fluid out of the compartment)]. We present a case of conservative treatment of elevated intra-compartmental pressure (ICP) of the anterior thigh after blunt trauma and the follow-up until return to sport. Conservative treatment of a compartment syndrome of the thigh after blunt trauma in a young patient without fracture or vascular damage was successful without short-term sequelae. Recovery of muscle strength is delayed but return to sport is possible. Depending on the severity the diagnosis and follow-up with ICP measurements and MRI is necessary. There is a very good chance for excellent outcome without any risk of surgery. However, a long healing time is possibl

    Pre-Harvest Sprouting Tolerance in 36 Bread Wheat Genotypes

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    Pre-harvest sprouting (PHS), promoted by rainfall during crop maturity, is a high problem in many wheat-producing regions of the world. Considering its importance in Brazil, 36 national and international varieties and advanced lines of wheat were evaluated for their tolerance to PHS. For this purpose, two experiments were conducted over three years. Seed pericarp rupture was used as an indicator of the beginning of germination. The data were analyzed using analysis of variance, the Scott-Knott test, and the Lin and Binns method. The wide range of germination percentage values allowed the genotypes to be classified as tolerant (in experiment 1 - ND 674 and Grandin*2/RL 4137 and experiment 2 - Frontana and Grandin) and moderately tolerant (Alsen, CD 114, and Milan/3/Attila//Fang 69/CIMMYT 3 in Experiment 1; Avante, BRS 177, IAC 5-MaringĂĄ, Onix, OR 1, RL 4137, and Rubi in Experiment 2). Because tolerance to PHS is under genetic control and can be improved through breeding programs, the challenge for wheat breeders is to combine increased PHS tolerance with other requirements to meet market demands

    Analysis of preharvest sprouting in three Brazilian wheat populations.

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    The objective of this work was to evaluate the possibility of obtaining recombinant inbred wheat lines more resistant to preharvest sprouting, independently of colour genes, in three red-grained Brazilian wheat populations. The results showed statistical significance among lines within all populations, which presented a normal distribution and transgressive segregation for preharvest sprouting. The normal distribution of the lines from all red-grained populations suggests that sprouting, excluding the genes expressing seed coat pigmentation, is, probably, controlled by many genes. These findings also indicate that it may be possible to improve resistance to preharvest sprouting, independently of the colour genes

    Hunter-gatherer children’s object play and tool use: An ethnohistorical analysis

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    Learning to use, make, and modify tools is key to our species’ success. Researchers have hypothesized that play with objects may have a foundational role in the ontogeny of tool use and, over evolutionary timescales, in cumulative technological innovation. Yet, there are few systematic studies investigating children’s interactions with objects outside the post-industrialized West. Here, we survey the ethnohistorical record to uncover cross-cultural trends regarding hunter-gatherer children’s use of objects during play and instrumental activities. Our dataset, consisting of 434 observations of children’s toys and tools from 54 hunter-gatherer societies, reveals several salient trends: Most objects in our dataset are used in play. Children readily manufacture their own toys, such as dolls and shelters. Most of the objects that children interact with are constructed from multiple materials. Most of the objects in our dataset are full-sized or miniature versions of adult tools, reflecting learning for adult roles. Children also engage with objects related to child culture, primarily during play. Taken together, our findings show that hunter-gatherer children grow up playing, making, and learning with objects

    Twenty six years of wheat breeding activities at IAPAR.

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    The description of the IAPAR wheat breeding program in its 26 th years of existence aims at presenting its major achievements giving an idea of the program size, breeding objectives and methodology. A germplasm flow chart will show the steps by which the populations have to follow starting either from crosses or from introductions until an advanced inbred line can be evaluated and elected as a new cultivar. A list of 23 wheat cultivars released by the program along with their pedigrees is presented as a special contribution. From the recent developed cultivars, data on grain yield, agronomic characteristics, technological quality and kernel properties are presented. The pedigree description for IAPAR 53 and the development of IPR 85 are presented in some detail. New biotechnological tools to help wheat breeding become more efficient are discussed

    Studying the kinetic parameters of BaTi5O11 by using the thermoluminescence technique

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    The present study discusses the thermoluminescence (TL) characteristics of monoclinic barium titanate (BaTi5O11) which is chemically prepared using the sol–gel technique. The crystallinity is confirmed by X-ray diffraction, and the oxidation state of each element, morphology, and particle size of the prepared powder are chemically probed by different spectroscopic tools including X-ray Photoelectron Spectroscopy and Energy dispersive X-Ray spectroscopy. The sample is irradiated by a beta (ÎČ)-source with different applied doses in the range of 1.1––385 Gy. The kinetic parameters which correspond to the charge carrier traps were determined. The analysis methods indicated that the TL glow curve of BaTi5O11 consists of 6 overlapped peaks corresponding to 6 electron traps. The values for the trap depth are found to be in the range 0.94–1.40 eV and the TL glow peaks are located between 380.4 and 560.5 K. The study confirms the potential of BaTi5O11 for ÎČ-dosimetry

    New information on the Havelte Group site Ahrenshöft LA 58 D (Nordfriesland, Germany) - Preliminary results of the 2008 fieldwork

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    Late Glacial processes of human colonisation, adaptation and development represent a large field of study with a wide range of approaches. With respect to the archaeological succession from the classic Hamburgian to the Havelte Group, studies on the latter are still rare in Northern Germany. This paper aims to contribute to the chronological and archaeological characterization of the Havelte Group by presenting some new results from the Ahrenshöft LA 58 D site. Located in a micro-region rich in Late Glacial occupations, especially of the Hamburgian, the site was the subject of excavation in 1995. Questions regarding the homogeneity and chronological attribution of the site had been raised, leading to further fieldwork in 2008. This included palynological, micro-tephra and soil micromorphology analyses, which were partly supplemented by samples collected in 2009. The preliminary results presented here confirm the absence of indications of archaeological heterogeneity and, despite taphonomic difficulties, seem to confirm a recent age for the occupation, after the early Late Glacial Interstadial and within the Havelte Group
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