bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling and modal analysis of seismic vibrator baseplate
Authors: Wei Zhouhong 
Published: May 2009

ABSTRACTThe vibroseis method must be extended to its limits as the search for oil and gas continues on land. To successfully improve vibroseis data quality, it is crucial to evaluate each element in the vibroseis data acquisition system and ensure that the contribution from each element is successful. Vibroseis systems depend greatly upon the ability of vibrators to generate synchronous, repeatable ground‐force sweeps over a broad frequency range. This requires that the reaction mass and the baseplate of the vibrator move as rigid bodies. However, rigid‐body motion is not completely true for high‐ frequency vibrations, especially for the vibrator baseplate. In order to accurately understand the motion of the vibrator baseplate, a finite element analysis model of the vibrator baseplate and the coupled ground has been developed. This model is useful for simulating the vibrator baseplate dynamics, evaluating the impact of the baseplate on the coupled ground and vibrator baseplate design. Model data demonstrate that the vibrator baseplate and its stilt structure are subject to six significant resonant frequencies in the range of 10–80 Hz. Due to the low rigidity of the baseplate, the baseplate stilt structure experiences severe rocking motions at lower frequencies and the baseplate pad experiences severe flexing motions at higher frequencies. Flexing motions cause partial decoupling, which gives rise to increased levels of harmonic distortion and less useable signal energy. In general, the baseplate pad suffers more bending and flexing motions at high frequencies than low frequencies, leading less efficiency in transmitting the useable energy into the ground.
Putting the ‘theory’ back into grounded theory: guidelines for grounded theory studies in information systems
Authors: Urquhart Cathy , Lehmann Hans , Myers Michael D. 
Published: May 2009

AbstractOver the past decade, there has been increasing interest in the use of grounded theory in information systems research. Grounded theory is a qualitative research method that seeks to develop theory that is grounded in data systematically gathered and analysed. The purpose of this paper is to suggest guidelines for grounded theory studies in information systems. Our guidelines are based on a framework for theorizing in grounded theory studies that focuses on conceptualization and theory scope. Our hope is that the guidelines will help to raise the quality and aspirations of grounded theory studies in information systems.
Missed nursing care: a concept analysis
Authors: Kalisch Beatrice J. , Landstrom Gay L. , Hinshaw Ada Sue 
Published: May 2009

AbstractTitle.  Missed nursing care: a concept analysis. Aim.  This paper is a report of the analysis of the concept of missed nursing care.Background.  According to patient safety literature, missed nursing care is an error of omission. This concept has been conspicuously absent in quality and patient safety literature, with individual aspects of nursing care left undone given only occasional mention.Method.  An 8‐step method of concept analysis – select concept, determine purpose, identify uses, define attributes, identify model case, describe related and contrary cases, identify antecedents and consequences and define empirical referents – was used to examine the concept of missed nursing care. The sources for the analysis were identified by systematic searches of the World Wide Web, MEDLINE, CINAHL and reference lists of related journal articles with a timeline of 1970 to April 2008.Findings.  Missed nursing care, conceptualized within the Missed Nursing Care Model, is defined as any aspect of required patient care that is omitted (either in part or in whole) or delayed. Various attribute categories reported by nurses in acute care settings contribute to missed nursing care: (1) antecedents that catalyse the need for a decision about priorities; (2) elements of the nursing process and (3) internal perceptions and values of the nurse. Multiple elements in the nursing environment and internal to nurses influence whether needed nursing care is provided.Conclusion.  Missed care as conceptualized within the Missed Care Model is a universal phenomenon. The concept is expected to occur across all cultures and countries, thus being international in scope.
Metabolomic analysis reveals a common pattern of metabolic re‐programming during invasion of three host plant species by Magnaporthe grisea
Authors: Parker David , Beckmann Manfred , Zubair Hassan , Enot David P. , Caracuel‐Rios Zaira , Overy David P. , Snowdon Stuart , Talbot Nicholas J. , Draper John 
Published: May 2009

SummaryThe mechanisms by which biotrophic and hemi‐biotrophic fungal pathogens simultaneously subdue plant defences and sequester host nutrients are poorly understood. Using metabolite fingerprinting, we show that Magnaporthe grisea, the causal agent of rice blast disease, dynamically re‐programmes host metabolism during plant colonization. Identical patterns of metabolic change occurred during M. grisea infections in barley, rice and Brachypodium distachyon. Targeted metabolite profiling by GC‐MS confirmed the modulation of a conserved set of metabolites. In pre‐symptomatic tissues, malate and polyamines accumulated, rather than being utilized to generate defensive reactive oxygen species, and the levels of metabolites associated with amelioration of redox stress in various cellular compartments increased dramatically. The activity of NADP‐malic enzyme and generation of reactive oxygen species were localized to pathogen penetration sites, and both appeared to be suppressed in compatible interactions. Early diversion of the shikimate pathway to produce quinate was observed, as well as accumulation of non‐polymerized lignin precursors. These data are consistent with modulation of defensive phenylpropanoid metabolism by M. grisea and the inability of susceptible hosts to mount a hypersensitive reaction or produce lignified papillae (both involving reactive oxygen species) to restrict pathogen invasion. Rapid proliferation of M. grisea hyphae in plant tissue after 3 days was associated with accelerated nutrient acquisition and utilization by the pathogen. Conversion of photoassimilate into mannitol and glycerol for carbon sequestration and osmolyte production appear to drive hyphal growth. Taken together, our results suggest that fungal pathogens deploy a common metabolic re‐programming strategy in diverse host species to suppress plant defence and colonize plant tissue.
The HD‐ZIP IV transcription factor OCL4 is necessary for trichome patterning and anther development in maize
Authors: Vernoud Vanessa , Laigle Guillaume , Rozier Frédérique , Meeley Robert B. , Perez Pascual , Rogowsky Peter M. 
Published: May 2009

SummaryAmong the genes controlling the differentiation and maintenance of epidermal cell fate are members of the HD‐ZIP IV class family of plant‐specific transcription factors, most of which are specifically expressed in the epidermis of tissues. Here, we report the functional analysis of the maize HD‐ZIP IV gene OCL4 (outer cell layer 4) via the phenotypic analysis of two insertional mutants, and of OCL4‐RNAi transgenic plants. In all three materials, the macrohairs, one of the three types of trichomes present on adult maize leaf blades, developed ectopically at the margin of juvenile and adult leaves. Consistent with this phenotype, OCL4 is expressed in the epidermis of the leaf blade, with a maximum at the margin of young leaf primordia. Expression of OCL4 in the model plant Arabidopsis under the control of the GLABRA2 (GL2) promoter, a member of the Arabidopsis HD‐ZIP IV family involved in trichome differentiation, did not complement the gl2‐1 mutant, but instead aggravated its phenotype. The construct also caused a glabrous appearance of rosette leaves in transformed control plants of the Ler ecotype, suggesting that OCL4 inhibits trichome development both in maize and Arabidopsis. Furthermore, insertional mutants showed a partial male sterility that is likely to result from the presence of an extra subepidermal cell layer with endothecium characteristics in the anther wall. Interestingly, the epidermis‐specific OCL4 expression in immature anthers was restricted to the region of the anther locule where the extra cell layer differentiated. Taken together these results suggest that OCL4 inhibits trichome development and influences division and/or differentiation of the anther cell wall.
Defect in non‐yellow coloring 3, an α/β hydrolase‐fold family protein, causes a stay‐green phenotype during leaf senescence in rice
Authors: Morita Ryouhei , Sato Yutaka , Masuda Yu , Nishimura Minoru , Kusaba Makoto 
Published: May 2009

SummaryChlorophyll degradation is an important phenomenon in the senescence process. It is necessary for the degradation of certain chlorophyll–protein complexes and thylakoid membranes during leaf senescence. Mutants retaining greenness during leaf senescence are known as ‘stay‐green’ mutants. Non‐functional type stay‐green mutants, which possess defects in chlorophyll degradation, retain greenness but not leaf functionality during senescence. Here, we report a new stay‐green mutant in rice, nyc3. nyc3 retained a higher chlorophyll a and chlorophyll b content than the wild‐type but showed a decrease in other senescence parameters during dark incubation, suggesting that it is a non‐functional stay‐green mutant. In addition, a small amount of pheophytin a, a chlorophyll a‐derivative without Mg2+ ions in its tetrapyrrole ring, accumulated in the senescent leaves of nyc3. nyc3 shows a similar but weaker phenotype to stay green (sgr), another non‐functional stay‐green mutant in rice. The chlorophyll content of nyc3 sgr double mutants at the late stage of leaf senescence was also similar to that of sgr. Linkage analysis revealed that NYC3 is located near the centromere region of chromosome 6. Map‐based cloning of genes near the centromere is very difficult because of the low recombination rate; however, we overcame this problem by using ionizing radiation‐induced mutant alleles harboring deletions of hundreds of kilobases. Thus, it was revealed that NYC3 encodes a plastid‐localizing α/β hydrolase‐fold family protein with an esterase/lipase motif. The possible function of NYC3 in the regulation of chlorophyll degradation is discussed.
Relationship of Birth Weight with the Size, Number and Proportion of Fibres in the Pig Semitendinosus Muscle
Authors: Tristán F. , Rivero M. A. , Albors O. L. , Ramis G. , Vázquez J. M. , Martínez M. , Martínez J. S. , Gil F. 
Published: May 2009

SummaryThe objective of this study was to determine the relationship between body weight and the size, number and proportion of muscle fibre types in the pig semitendinosus muscle at birth. Based on weight at birth, 68 specimens selected from 21 different litters from the same farm were allotted in two equal groups (G1 and G2). G1 included 34 piglets ≤1.1 kg and G2 34 pigs ≥2 kg. Fifteen piglets per group were killed at birth and the remaining 19 piglets in each group were reared until weaning (21 days) and post‐weaning (67 days). The weight and total cross‐sectional area of the semitendinosus muscle were recorded at birth. Then, type I and type II fibres from the superficial portion of the muscle were identified according to histochemistry and immunohistochemistry techniques and percentages, average size of each fibre type, and the total number of muscle fibres were estimated by morphometry. Birth weight in G1 was 54.74% lower than that in G2. Correspondingly, the total cross‐sectional area of the semitendinosus, as well as the size and number of muscle fibres, was significantly lower in G1 (P < 0.001). Weight at birth still influenced weights at weaning and post‐weaning, hence it was 43.17% and 28.38% lower respectively in G1. It is concluded that pig weight at birth is associated with muscle cellularity of the semitendinosus muscle of pig, which may influence the postnatal muscle growth and final size of muscle fibres and meat quality.
Anti‐Predator Signals as Advertisements: Evidence in White‐Throated Magpie‐Jays
Authors: Ellis Jesse M. S. 
Published: May 2009

AbstractCalls and displays elicited by predators usually function as alarms or to inform predators of their detection. However, predator encounters may afford some individuals the opportunity to demonstrate quality or signal their availability. Here, I report on a class of vocal signals produced in predator‐elicited displays that share many characteristics with sexually selected song. White‐throated magpie‐jays (Calocitta formosa) display at low‐threat predators while producing ‘loud display calls’ (LDCs). I use this term because the calls occur primarily in two display contexts (see below) though occasionally in other contexts as well. Such calls and displays are primarily produced by males, and also occur in one other context, at dawn. Playback experiments showed that despite being elicited by predators, males were more likely than females to respond to LDCs, and more likely to respond when their mate was fertile. Over 134 different call types were produced in over 200 displays by 34 males; the largest minimum repertoire size was 67. Presentations of taxidermic raptor mounts elicited some LDCs, but fewer calls and lower diversity than at dawn or in predator approach displays. The male bias and high diversity suggest that LDCs are an outcome of intersexual selection, while their elicitation by predators suggests an alarm function. I propose that male magpie‐jays use predator encounters as opportunities to advertise their presence and availability as mates; they use LDCs as songs. Such a communication system seems to have been favored by the unusual social system of magpie‐jays, in which female groups defend territories and males have little opportunity to defend resources for mate attraction, forcing them to advertise when females are paying the most attention, during predator encounters.
What Does Mutual Grooming Tell Us About Why Chimpanzees Groom?
Authors: Fedurek Pawel , Dunbar Robin I. M. ,   for the British Academy Centenary Research Project
Published: May 2009

AbstractGrooming might be a resource that is offered in exchange for some benefit (e.g. access to a feeding site or coalitionary support) or it might be a mechanism for building and servicing social relationships, whose function, in turn, is to facilitate the exchange of resources and services. Bi‐directional (or simultaneous mutual) grooming is unusually common among chimpanzees (though rare in other primates) and we suggest that this might be because it is an especially strong indicator of social bonding. Because the bonding role of bi‐directional grooming offers substantially different predictions from the interpretation offered by the models based on reciprocal altruism (RA), we use a critical tests methodology (i.e. tests that unequivocally support one hypothesis at the expense of the other) to differentiate between the bonding and RA hypotheses. We use data on the dynamics of grooming interactions from a captive group of chimpanzees (Pan troglodytes) to show that dominant individuals tolerated the individuals with whom they performed bi‐directional grooming more than they did those who typically provided them unidirectional grooming. Dominants rejected and terminated grooming sessions more often with the individuals who provided them with mostly unidirectional grooming than with those with whom they groomed bi‐directionally. In addition, animals engaged in bi‐directional grooming more often with both relatives and those with whom they were often in proximity. These results support the bonding model of mutually reciprocated grooming at the expense of the RA model, and suggest that, at least in chimpanzees, simultaneous mutual grooming may play a particularly important role in social bonding.
Who is Calling? Intraspecific Call Variation in the Aromobatid Frog Allobates femoralis
Authors: Gasser Herbert , Amézquita Adolfo , Hödl Walter 
Published: May 2009

AbstractMany territorial species respond less aggressively to familiar neighbours than to unfamiliar floating strangers based on individual differences in acoustic signals. This form of social recognition, termed neighbour–stranger discrimination (NSD) or dear‐enemy phenomenon has been reported so far from three anuran species. To investigate the potential of auditory signal features to convey information on sender’s identity, we determined patterns of within‐male and between‐male variability in the advertisement call of the aromobatid frog Allobates femoralis. We examined 285 calls from 19 males to assess those call properties showing sufficient and reliable inter‐individual differences to function as possible recognition cues. Beside calls per call bout and call rate, all other examined call properties were more variable among males than within males. Generally, temporal call features showed higher between‐ and within‐male variability ratios than spectral properties and contributed mostly to distinguish individual males in the discriminant‐function analysis. Mean classification success of 64.9% correctly assigned calls to individual males is mainly attributable to three temporal call properties (duration of note 1 and 4, note repetition rate). Altogether, our results suggest that there is sufficient variation in the advertisement call to discriminate statistically among individual males. However, assessed call differences between A. femoralis males were rather small, suggesting that potential NSD might be based either on a combination of call features or even on the whole pattern of individual call variation instead on single call properties. Habituation–discrimination experiments in the field using modified playback signals to test for differential behavioural responses are required to confirm this hypothesis.
Response of BITS (a benthic index based on taxonomic sufficiency) to water and sedimentary variables and comparison with other indices in three Adriatic lagoons
Authors: Munari Cristina , Manini Elena , Pusceddu Antonio , Danovaro Roberto , Mistri Michele 
Published: May 2009

AbstractThe European Water Framework Directive (WFD, 2000/60/EC) recommends the development of biotic indices for assessing the ecological quality status of water bodies. The Benthic Index based on Taxonomic Sufficiency (BITS) was specifically developed for lagoonal systems, according to the tolerant/opportunistic approach. Macrobenthic data, variables indicative of eutrophication and variables indicative of sedimentary organic matter quality were collected during 18 surveys carried out between 2004 and 2005 in three Adriatic coastal lagoons (Venice Lagoon, Sacca di Goro, Lesina Lagoon). The relationship between environmental variables and biotic indices (AMBI, BENTIX, BITS, BOPA and FINE) was tested using multivariate analyses. Indices based on species classification level appeared to relate better with the variables describing organic matter quality, whereas BITS, which is based on family classification level, seemed related to eutrophication indicative variables, such as sulphide, ammonium, dissolved oxygen and orthophosphate concentrations. The BITS approach reduces the costs associated with sorting and identification of organisms. Providing a rapid assessment of ecological quality, and producing an ecologically relevant classification, BITS seems a promising tool for monitoring programs of Adriatic lagoonal ecosystems. Its sensitivity in reflecting the field conditions elsewhere, however, remains to be assessed.
Histological and Immunohistochemical Characterization of Equine Anovulatory Haemorrhagic Follicles (AHFs)
Authors: Ellenberger C , Müller K , Schoon H‐A , Wilsher S , Allen WR 
Published: May 2009

ContentsAnovulatory haemorrhagic follicles (AHFs) are often the reason for ovulation failure in the mare. As the underlying factors that lead to AHF development are not well understood, it was of interest to investigate the vascularization of AHFs compared with normal follicles and corpora lutea (controls). In the present study, the ovarian cell populations investigated immunohistochemically included granulosa and luteal cells as well as various vascular structures. None of these cell types showed differences in the expression of vascular endothelial growth factor A (VEGF‐A) between control ovaries containing normal follicles and corpora lutea and ovaries with AHFs. In contrast, a considerable reduction in the proportion of Flk‐1‐expressing cells, together with a decreased intensity of staining, was apparent in the AHFs. This greatly reduced expression of Flk‐1 in the luteinized cells and the vascular structures of AHFs may lead to a distinct decrease in the potential pro‐angiogenic activity of VEGF‐A in these structures compared with the situation in normal follicles and corpora lutea. Furthermore, the authors suspect that the distinct expression of angiopoietin2 and VEGF‐A seen in the cells within the inner fibrous layers of the AHFs was caused by hypoxia resulting from deficient vascularization, as suggested by the irregularity of the capillaries present in the luteinized wall of the AHF. In addition, whereas LH‐receptor (LH‐R) expression occurred uniformly in all stages of development of the corpora lutea in normal control ovaries, there was highly variable labelling for LH‐R in all the AHFs examined, thereby indicating a possible numerical deficiency of LH‐receptors in AHFs. The authors concluded that, despite the apparent expression of sufficient VEGF‐A in the AHFs allows ovulation and corpus luteum formation, a relative lack of receptor, Flk‐1, effects the pro‐angiogenic activity of VEGF‐A which could be a reason for ovulation failure associated with AHF formation.
Effect of eCG or eCG Plus hCG on Oestrus Expression and Ovulation in Prepubertal Gilts
Authors: Manjarin R , Cassar G , Sprecher DJ , Friendship RM , Dominguez JC , Kirkwood RN 
Published: May 2009

ContentsTo meet weekly breeding targets, it is occasionally necessary to inject exogenous gonadotrophins to induce oestrus in prepubertal gilts. However, the gilt oestrus response to equine chorionic gonadotrophin (eCG) either alone or in combination with human chorionic gonadotrophin (hCG) can be unpredictable. The objective of the present study was to examine possible reasons for this unpredictability. Prepubertal gilts (90 kg and 153 days of age, n = 109) received an injection of either 600 IU eCG or a combination of 400 IU eCG and 200 IU hCG (PG600), or were non‐injected controls, and were then exposed to a mature boar for 15 min daily for 7 days for oestrus detection. At the time of injection, real‐time ultrasound revealed that the gilt ovaries had primarily 1–2 mm follicles. Blood samples were obtained at time of hormone injection (day 0) and at days 3, 7 and 10 for assay of serum progesterone concentrations. The oestrus responses by 7 days were15.5%, 73.3% and 0%, for eCG, PG600, and control gilts, respectively (p < 0.001). The oestrus response improved (p < 0.05) with increasing body weight. Based on circulating progesterone levels, all oestrous gilts ovulated except for four of the PG600 gilts. Failure to express oestrus in PG600 gilts was not associated with a premature rise in progesterone.