bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential translocation of paraquat in paraquat‐resistant populations of Hordeum leporinum
Authors: PRESTON C , SOAR C J , HIDAYAT I , GREENFIELD K M , POWLES S B 
Published: July 2005

SummaryTwo populations of Hordeum leporinum have evolved resistance to paraquat within a small area in central Tasmania, Australia. One population (THL1) was more than 80‐fold resistant to paraquat when treated in winter, compared with a susceptible population (THL4) collected nearby, whereas the other population (THL2) was only 19‐fold resistant. Translocation of paraquat was examined in all three populations at warm and cool temperature regimes. Herbicide was applied to a basal section of the second leaf of plants kept in the dark and translocation measured after 16 h of dark and during a subsequent light period. Paraquat absorption into the treated leaf was uniformly high in susceptible and resistant populations, with >93% of the applied herbicide absorbed within 16 h in the dark at both temperatures. Translocation of paraquat out of the treated leaf was low in the dark, with <4% of the herbicide translocated to the remainder of the plant. More herbicide was translocated out of the treated leaves in susceptible plants in the dark, compared with resistant plants at both temperature regimes and more paraquat was translocated at warmer temperatures. Extensive basipetal translocation of paraquat to the rest of the plant occurred in susceptible plants following exposure of the treated plants to light. However, basipetal translocation was much reduced in resistant plants in the light and corresponded to the degree of resistance. Resistance to paraquat in H. leporinum is the result of reduced translocation of paraquat out of the treated leaves.
Increased density and spatial uniformity increase weed suppression by spring wheat
Authors: OLSEN J , KRISTENSEN L , WEINER J , GRIEPENTROG HW 
Published: July 2005

SummaryIt has been hypothesized that increased crop density and spatial uniformity can increase weed suppression and thereby play a role in weed management. Field experiments were performed over 2 years to investigate the effects of the density and spatial arrangement of spring wheat (Triticum aestivum) on weed biomass and wheat yield in weed‐infested fields. We used three crop spatial patterns (normal rows, random and uniform) and three densities (204, 449 and 721 seeds m−2), plus a fourth density (1000 seeds m−2) in the random pattern. Increased crop density reduced weed biomass in all three patterns. Weed biomass was lower and crop biomass higher in wheat sown in the random and uniform patterns than in normal rows in both years. At 449 seeds m−2, weed biomass was 38% lower in the uniform and 27% lower in the random pattern than in rows. There was evidence of decreasing grain yield due to intraspecific competition only at 1000 seeds m−2. The results not only confirm that increasing density and increasing crop spatial uniformity increase the suppression of weeds, but also suggest that a very high degree of spatial uniformity may not be necessary to achieve a major increase in weed suppression by cereal crops. Rows represent a very high degree of spatial aggregation. Decreasing this aggregation increased weed suppression almost as much as sowing the crop in a highly uniform spatial pattern. While the random pattern produced as much crop biomass and suppressed weeds almost as well as the uniform pattern, the uniform pattern gave the highest yield.
Germination ecology, emergence and host detection in Cuscuta campestris
Authors: BENVENUTI S , DINELLI G , BONETTI A , CATIZONE P 
Published: July 2005

SummaryTrials were carried out to study the germination and dormancy of Cuscuta campestris Y. (dodder) seeds and factors influencing the success of early parasitisation of sugarbeet. Primary dormancy can be removed by seed scarification. Germination was negligible at 10°C and optimal at 30°C, while it was not influenced by light. Seed burial induced a cycle of induction and breaking of secondary dormancy. Seedling emergence was inversely proportional to the depth of seed burial and only seed buried within 5 cm of the soil surface emerged. Storage of C. campestris seeds in a laboratory for 12 years resulted in the loss of primary dormancy, enabling the germination of all viable seeds. Host infection (i.e. protrusion of parasite haustoria from host tissue) was heavily influenced by host growth stage. Tropism towards a host was due to the perception of light transmitted by green parts of sugarbeet plants. Insertion of a transparent glass sheet between host leaves and parasite seedlings did not modify this response. This phototropism permitted Cuscuta to identify host plants with high chlorophyll content as a function of the lower red/far red ratio of transmitted light.
Factors affecting the efficacy of acrolein in irrigation channels in southern Argentina
Authors: BENTIVEGNA D J , FERNÁNDEZ O A 
Published: July 2005

SummaryGrowth of the submerged weed Potamogeton pectinatus L. is a major problem in the irrigation channels located in the Lower Valley of the Colorado River (39°10′–39°55′S; 62°05′–63°55′W) in Argentina. Previous studies indicate that weed control with acrolein is effective in reducing submerged plant biomass. In this study, we evaluated the influence of some variables affecting acrolein and its dissipation in water. Three main parameters, acrolein dosage, the height of the plants and the velocity of water contributed to 80% of the reduction of the submerged weed biomass. Water flow and concentration of the chemical explained 68% of the factors influencing the dissipation of the herbicide. Water velocity, electrical conductivity, pH and the duration of application have a secondary effect in the dissipation process. The constant rate of dissipation (K) was 0.235 L h−1 (SD ±0.125), implying that the chemical will disappear from the system in <24 h. As a practical guideline for the control of mature, dense stands of P. pectinatus within the irrigation system under study, the following conditions are advisable: flow volumes of 500 L s−1 or higher, water velocity of 0.42 m s−1 or more and c. 6.5 mg L−1 concentration of acrolein for at least a 11‐h period.
Interspecific Social Interactions and Breeding Success of the FrogRana latastei: A Field Study
Authors: Ficetola Gentile Francesco , Bernardi Fiorenza De 
Published: July 2005

AbstractInterspecific reproductive interference can affect fitness‐related breeding performance, thus influencing fitness and distribution of populations. Laboratory studies demonstrated the social interference ofRana dalmatinamales onR. latasteibreeding females: the presence of heterospecific males reduced the percentage of viable embryos inR. latasteieggs. Here, we tested if the negative effects ofR. dalmatinamales onR. latasteireproductive success occur in field conditions. We compared the percentage of viable embryos of eggs laid in field conditions from populations whereR. latasteibreeds alone with the percentage of viable embryos of populations whereR. latasteicohabits withR. dalmatina. We did not find any significant difference in percentage of viable embryos betweenR. latasteipopulations syntopic and allotopic withR. dalmatina, nor a relationship between the relative abundance of heterospecifics and reproductive success. In natural conditions, the presence of heterospecific males does not seem to interfere with the reproductive success ofR. latastei. The experimental procedure may influence the interaction among individuals. Therefore, we suggest to validate on natural populations the results of experiments dealing with complex interactions.
Sensory Systems and Spatial Memory in the Fruit BatRousettus aegyptiacus
Authors: Holland Richard A. , Winter Paul , Waters Dean A. 
Published: July 2005

AbstractThe megachiropteran fruit batRousettus aegyptiacusis able to orient and navigate using both vision and echolocation. These two sensory systems have different environmental constraints however, echolocation being relatively short range when compared with vision. Despite this difference, an experiment testing their memory of a perch location demonstrates that once the location of a perch is learnedR. aegyptiacusis not influenced by the movement of local landmark cues in the vicinity of the perch under either light or dark conditions. Thus despite the differing constraints of vision and echolocation, this suggests a place is remembered as a location in space and not by associations with landmarks in the vicinity. A decrease in initial performance when the task was repeated in the dark suggested the possibility that a memory of a location learned using vision does not generalize to echolocation.
Ultrastructure de la spermiogenèse et du spermatozoïde de Loimosina wikoni et affinités phylétiques des Loimoidae (Plathelminthes, Monogenea, Monopisthocotylea)
Authors: JUSTINE JEAN‐LOU , MATTEI XAVIER 
Published: July 2005

In Loimosina, during spermiogenesis, the zone of differentiation of the spermatid contains two centrioles continued as two 9 +‘1’axonemes. One of the axonemes lengthens and will become the principal axoneme of the spermatozoon. The other axoneme is as long as the first one at the beginning of spermiogenesis, but is shorter in the mature sperm cell. The spermatozoon consists of several regions: (a) at the anterior end, the centriolar derivative of the principal axoneme; (b) a short region which shows cortical microtubules coinciding with external ornamentations; (c) a long uniflagellate region, with mitochondrion; (d) a biflagellate region containing the anterior slender part of the nucleus; (e) the posterior part of the nucleus, with no accompanying cytoplasmic organelles. Spermiogenesis and sperm structure in Loimosina differ from what is known in all other described monogeneans, excepting the monocotylid Heterocofyle to which they show close resemblances. However, the alteration of the second axoneme is more complete in Heterocofyle than in Loimosina. Comparative study of spermiogenesis and sperm ultrastructure thus shows an interesting coincidence with classical phylogenies of the monogeneans, in which the families Loimoidae and Monocotylidae are closely related.Chez Loimosina, pendant la spermiogenèse, la zone de différenciation de la spermatide contient deux centrioles prolongés par deux axonemes de type 9 +‘1′. L'un des axonemes s'allonge et deviendra l'axonème principal du spermatozoïde mûr. Le deuxième axontme est aussi long que le premier au début de la spermiogenèse, mais il est plus court dans le spermatozoïde mûr. Le spermatozoïde comprend: (a) à l'avant, le dérivé centriolaire de l'axonème principal; (b) une courte région contenant quelques microtubules corticaw longitudinaux coincidant avec des omementations extramembranaires; (c) une longue région miflagellée avec mitochondrie; (d) une région biflagellée contenant La partie antérieure effilée du noyau; (e) la région postérieure du noyau, sans organites cytoplasmiques accompagnateurs. La spermiogenèse et la structure du spermatozoïde de Loimosina sont différentes de ce qui est connu chez tous les autres Monogènes décrits, excepté le Monocotylidae Heterocofyle auquel elles ressemblent beaucoup. Toutefois, l'altération du deuxième axonème est moins complète chez Loimosina que chez Heterocotyle. L'étude comparée des spermatozoïdes et des spermiogenèses montre une bonne coincidence avec les phylogenèses classiques, dans lesquelles les familles Loimoidae et Monocotylidae sont proches.
Structures comparées du système reproducteur de quelques nématodes marins Sphaerolaimidae
Authors: GOURBAULT NICOLE 
Published: July 2005

Description détaillée des structures génitales de Sphaerolaimus hirsutus. En comparaison, une grande similitude morphologique se retrouve chez les mâles de cinq autres espèces du même genre. Chez les femelles, en revanche, à un schéma général commun, viennent s'adjoindre des caractères spécifiques renforçant les coupures taxonomiques au sein de la famille; ceux‐ci sont essentiellement liés au stockage du sperme.The structure of the reproductive system of Sphaerolaimus hirsutus is described in detail. Comparatively, in males of five congeneric species a significant morphological similarity has been found. In contrast, in corresponding females a common basic structure is present, together with additional specific features. These differing traits are in accordance with the previously established taxonomic divisions in the family; most of these features are in connection with female sperm storage.
Ecdysial cleavage lines of acariform mites (Arachnida, Acari)
Authors: NORTON ROY A. , KETHLEY JOHN B. 
Published: July 2005

Among mites the ancestral ecdysial cleavage line, or line of dehiscence (a), is inferred by outgroup comparison to be prodehiscent: U‐shaped, passing around the front of the mite just above the insertions of the appendages, such that the mite ecloses anteriorly. From preserved and living individuals and exuviae, we found prodehiscence (or its slight variations) to be widespread in Acariformes. It appears to be pervasive in endeostigmatic mites, eupodine Prostigmata, and basal taxa in the Oribatida (Enarthronota, Palaeosomata); it is dominant in cleutherengone Prostigmata and is present in at least one anystine family (Caeculidae).Three general modes of dehiscence are considered to be derived within acariform mites. (1)Merodehiscenceis a transverse splitting of the dorsal cuticle at or near the juncture of proterosoma and hysterosoma; it evolved separately in thrcc groups of Prostigmata (Tetranychidae, an undefined subgroup within Cheylctidae, and active instars of Parasitengona) and in a genus of Astigmata (Histiogaster). (2)Trarnsdehiscenceis a transverse splitting of the dorsal hysterosomal cuticle anterior to the opisthosomal glands; it occurs in middle‐derivative oribatid mites (the paraphyletic Desmonomata), and new observations show it to be widespread in Astigmata, lending support to the hypothesis that the latter group evolved from within Desmonomata. (3)Circumdehiscenceis a circumferential splitting of the hysterosomal cuticle that may be incomplete anteriorly; it has long been known to characterize the monophyletic oribatid taxon Brachypylina, but it is convergent with a similar dehiscence in an unrelated family, Lohmanniidae. Transdehiscent and circumdehiscent mites eclose posteriorly.Astigmata exhibit the greatest variety of modes of dehiscence, including the three derived modes and a probable reversal to prodehiscence in Algophagidae. Furthermore, heteromorphic deutonymphs (hypopi) may ecdyse differently from other immature instars of the same species.
The preoral cavity of lower Hymenoptera (Insecta): comparative morphology and phylogenetic significance
Authors: VILHELMSEN LARS 
Published: July 2005

The skeletal and muscular morphology of the preoral cavity, including the labrum, hypopharynx and labium, was examined in the imago in representatives of all the ‘symphytan’ families as well as the apocritan families Stephanidae, Megalyridae and Trigonalyidae.Xyelidae have complex modifications for masticating pollen, remarkably similiar to those of primitive Lepidoptera. These modifications, collectively termed the triturating basket complex, include an asymmetrical distal epipharyngeal wall with a microtrichial brush and an enlarged infrabuccal pouch with heavy cuticular armature that interacts with the mandibles during feeding. There were striking structural differences between the two subfamilies of Xyelidae in the ligular region; the reduced glossa and clubshaped paraglossae of Macroxyelinae resembles those of primitive Lepidoptera, while the well developed, flattened glossa and paraglossae in Xyelidae are similiar to those of most other ‘Symphyta’.A putative transformation series, leading from a relatively large labrum with unsclerotised distal epipharyngeal wall lying anterior to the mandibles, as seen in Xyelidae and enthredinoidea, to a small and heavily sclerotised labrum and distal epipharyngeal wall lying posterior to the mandibles, as seen in ‘Siricoidea’, Orussidae and the Apocrita, was revealed. These modifications may be adaptations to enable the adult of the families pupating in wood to emerge from the pupal chamber.The Anaxyelidae, Orussidae and Apocrita have similiar configurations of the glossa and nsertions of the ventral premental adductors. This indicates a close affinity of the Anaxyelidae to Orussidae + Apocrita, a hypothesis that is in conflict with other character systems. The Orussidae and Stephanidae share a unique condition in the development of a pair of large apodemes attached to the labrum; this renders the groundplan state of the labrum in the Apocrita uncertain.Twentyfive characters were defined in an attempt to eludicate the ‘Symphyta’–Apocrita transition. A numerical cladistic analysis of the characters was undertaken, resulting in 522 minimum length trees. The characters are also discussed with reference to a cladogram which resulted from an analysis of the characters derived from the present study and a survey of characters from literature.
Modeling Color Properties of Tiled Displays
Authors: Majumder Aditi , Gopi M. 
Published: July 2005

AbstractThe concept of tiled displays can be successful only if such displays are made to look like a single display perceptually. The two issues that need to be solved to achieve this goal are geometric correction and color seamlessness of images spanning across tiles. Geometric correction algorithms borrow pin‐hole camera models to model projector display geometry. In this paper, we introduce an abstract modeling function that describes the color seen by a viewer when displayed by a display device.Though this function can be used to model color displayed by any common display device, in this paper, we use it to model color in multiprojector display systems. We use the model to explain the reasons for different types of color variations in a multiprojector display, to compare different color correction algorithms, and to derive such algorithms directly from the model.
Dual Marching Cubes: Primal Contouring of Dual Grids
Authors: Schaefer Scott , Warren Joe 
Published: July 2005

AbstractWe present a method for contouring an implicit function using a grid topologically dual to structured grids such as octrees. By aligning the vertices of the dual grid with the features of the implicit function, we are able to reproduce thin features of the extracted surface without excessive subdivision required by methods such as Marching Cubes or Dual Contouring. Dual Marching Cubes produces a crack‐free, adaptive polygonalization of the surface that reproduces sharp features. Our approach maintains the advantage of using structured grids for operations such as CSG while being able to conform to the relevant features of the implicit function yielding much sparser polygonalizations than has been possible using structured grids.
Generalized two‐sample U‐statistics for clustered data
Authors: Lee Mei‐Ling Ting , Dehling Herold G. 
Published: July 2005

In this paper we investigate two‐sample U‐statistics in the case of clusters of repeated measurements observed on individuals from independent populations. The observations on the i‐th individual in the first population are denoted by , 1 ≤ i ≤ m, and those on the k‐th individual in the second population are denoted by , 1 ≤ k ≤ n. Given the kernel φ(x, y), we define the generalized two‐sample U‐statistic by
image
We derive the asymptotic distribution of Um,n for large sample sizes. As an application we study the generalized Mann–Whitney–Wilcoxon rank sum test for clustered data.
Book Notes
Authors: Carter‐Boone La Shonda 
Published: July 2005

John D. Donahue, Making Washington Work: Tales of Innovation in the Federal Government.Bryan C. Hassel, The Charter School Challenge: Avoiding the Pitfalls, Fulfilling the Promise.Joseph Losco and Brian L. Fife (Eds.), Higher Education in Transition: The Challenges of the New Millennium.Toni Marzotto, Vicky Moshier Burnor, and Gordon Scott Bonham, The Evolution of Public Policy: Cars and the Environment.Gregory E. McAvoy, Controlling Technocracy: Citizen Rationality and the Nimby Syndrome.Kant Pate1 and Mark E. Rushefsky, Health Care Politics and Policy in America.Kevin Theakston, (Ed.), Bureaucrats and Leadership.
Identification of Novel Human Hepatitis E Virus (HEV) Isolates and Determination of the Seroprevalence of HEV in Korea
Authors: Ahn Jeong-min , Kang Sang-Gyun , Lee Deog-Yong , Shin Sung Jae , Yoo Han Sang 
Published: July 2005

ABSTRACT
Hepatitis E virus (HEV) was originally identified as the causative agent of enterically transmitted non-A, non-B hepatitis. Recently, HEV isolates were subsequently identified in humans and swine in many countries, including Korea. Also, public concerns regarding HEV as a potential zoonotic agent have been increasing. Therefore, we attempted to identify HEV from Korean sera and compare the nucleotide sequences with those of previously identified HEV isolates from other countries. In our study, viral RNA was purified from 568 human sera collected from different regions of Korea. Nested PCR and reverse transcriptase PCR were developed based on the nucleotide sequences of open reading frame 2 (ORF 2) of U.S. and Japanese HEV isolates from humans and Korean HEV isolates from swine. After amplification of the HEV ORF 2 gene from 14 serum samples that were collected mainly from rural areas (2.64% prevalence of HEV viremia), the gene was cloned and sequenced. The isolates were classified into seven different strains, all of which belonged to genotype III. The human isolates we identified were closely related to three Korean swine isolates, with 99.2 to 92.9% nucleotide sequence homology. Our isolates were also related to the Japanese and U.S. HEV isolates, with 99.6 to 97.9% amino acid sequence homology. Human sera were collected from 361 individuals from community health centers and medical colleges. With respect to seroprevalence, 11.9% of the Korean population had anti-HEV immunoglobulin G (IgG). In individuals ranging in age from 40 to over 60 years, the prevalence of anti-HEV IgG was demonstrated by a seroprevalence of almost 15%, especially among populations in rural areas. This is the first report on the identification of human HEV in Korea. Overall, this study demonstrates that subclinical HEV infections may prevail in human populations in Korea and that there is a strong possibility that HEV is a zoonotic agent.