bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sulphide intrusion in eelgrass (Zostera marinaL.)
Authors: PEDERSEN O. , BINZER T. , BORUM J. 
Published: May 2004

ABSTRACTSudden events of seagrass die‐off have been suggested to be induced by invasion of the phytotoxin sulphide under environmental stress generating low oxygen supply in seagrass tissues. Laboratory experiments were conducted with eelgrass (Zostera marinaL.) to measure intra‐plant changes in oxygen and sulphide by means of microelectrodes at different oxygen concentrations in the water column. The objectives were to examine whether sulphide intrusion into seagrass tissues can be induced, to determine the role of plant oxygen status for sulphide intrusion and to determine how fast internal sulphide pools are depleted after internal oxygen supplies have been restored. Under conditions with oxygen partial pressures (pO2) above 7.4 kPa (> 35% of air saturation) within eelgrass rhizomes or meristematic tissues no intrusion of sulphide occurred in spite of high sediment concentrations of gaseous sulphide (> 1000 µm). Lack of sulphide intrusion at high internal pO2suggested that oxygen release from the roots ensured complete re‐oxidation of sulphide in the rhizosphere. Under oxygen stress, however, the experiments clearly demonstrated intrusion of sulphide in eelgrass rhizomes and meristematic tissues. Rates of sulphide intrusion were controlled by internal pO2, which in turn was controlled by water column oxygen concentrations. Maximum internal sulphide content reached 325 µmwhich by far exceeded the 1–10 µmknown to inhibit mitochondrial activity in eukaryotic cells. Sulphide and low levels of oxygen could coexist in the eelgrass tissues reflecting fast internal transport of sulphide and slow rates of sulphide re‐oxidation. Upon re‐establishment of high internal oxygen concentrations the depletion of the sulphide pool was slow (half‐life = 20–30 min) indicating, that sulphide re‐oxidation within the eelgrass tissue was not bacterially or enzymatically facilitated but occurred by simple chemical oxidation. The results of this study are consistent with the proposed detrimental role of sulphide intrusion in events of sudden seagrass die‐off.
A novel stress‐acclimation response in Spirodela punctata (Lemnaceae): 2,4,6‐trichlorophenol triggers an increase in the level of an extracellular peroxidase, capable of the oxidative dechlorination of this xenobiotic pollutant
Authors: JANSEN M. A. K. , HILL L. M. , THORNELEY R. N. F. 
Published: May 2004

ABSTRACTPeroxidases are haem‐containing enzymes capable of oxidizing a wide range of substrates. This article describes the presence of peroxidase activity in the growth medium of axenic Spirodela punctata (Lemnaceae) cultures. It was found that the release of extracellular peroxidase activity is specifically enhanced by phytotoxic, halogenated phenols but not by other abiotic stress‐factors, elicitors or plant metabolites. Based on the concentration dependence of 2,4,6‐trichlorophenol (TCP)‐enhanced peroxidase release, it is concluded that release is not simply a consequence of physiological damage, but rather requires metabolically healthy fronds. In vitro studies (UV/VIS spectroscopy and liquid chromatography/mass spectrometry) show that the extracellular duckweed peroxidase (SpEx), which was partially purified from Spirodela growth medium, is capable of catalysing the oxidative dechlorination of TCP with hydrogen peroxide as the electron acceptor. It is proposed that the ability of S. punctata to specifically sense environmentally persistent phytotoxic chlorophenols, and to respond by increasing extracellular levels of a peroxidase capable of catalysing their oxidative dechlorination, is part of the protection strategy of this aquatic plant against xenobiotic stress.
High light enhances the expression of low‐CO2‐inducible transcripts involved in the CO2‐concentrating mechanism in Synechocystis sp. PCC6803
Authors: MCGINN P. J. , PRICE G. D. , BADGER M. R. 
Published: May 2004

ABSTRACTThe relative abundances of key gene transcripts encoding proteins involved in inducible inorganic carbon (Ci) transport in the cyanobacterium Synechocystis PCC6803 were quantified by real‐time reverse‐transcriptase‐polymerase chain reaction under conditions of varying Ci and light levels. Significant increases in CO2‐concentrating mechanism (CCM)‐related transcript abundance were observed only in cells aerated with CO2‐free air for 30 min in the light, but not in the dark, relative to illuminated cells grown at high CO2 levels (high‐Ci cells). Cells were incubated under precisely defined conditions in a cuvette attached to a mass spectrometer to allow for the measurement of photosynthetic gas exchange rates, [Ci] and [O2], in combination with quantitative analysis of transcripts. Under conditions of increasing irradiance and low [Ci], or under conditions of decreasing [Ci] at constant irradiance, the abundances of cmpA (encoding part of the BCT1 HCO3– transporter), ndhF3 (encoding subunit of high‐affinity CO2 uptake system) and sbtA (encoding Na+‐dependent HCO3– transporter) transcripts tended to increase, relative to illuminated cells grown at high‐CO2. The cmpA transcript appeared to be less responsive to decreasing [Ci] than either ndhF3 or sbtA. The induction of cmpA and ndhF3 transcripts was completely inhibited by 10 µm 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea (DCMU) compared to untreated control cells. This inhibitor had no effect on sbtA expression. In the presence of 2,6‐dichlorobenzoquinone (DCBQ), the expression of the cmpA transcript tracked the apparent rate of O2 evolution from photosystem II closely as the irradiance was increased, reaching maximum levels of expression approximately 16‐fold higher than control cells. Under the same conditions, the ndhF3 transcript increased by two‐ to three‐fold, whereas the sbtA transcript did not respond to this treatment. The regulation of CCM induction in this strain is discussed in relation to current hypotheses on the sensing of Ci limitation.
Environmental regulation of photosynthetic metabolism in the amphibious sedge Eleocharis baldwinii and comparisons with related species
Authors: UENO O. 
Published: May 2004

ABSTRACTThe amphibious leafless sedge, Eleocharis baldwinii, expresses C4 characteristics in the terrestrial form and intermediate characteristics between C3 and C4 photosynthesis in the submerged form. This study examined the immunocytochemical localization of C3 and C4 enzymes in culms of the two forms to elucidate the regulatory mechanism of photosynthetic metabolism and compared the activities and amounts of C3 and C4 enzymes with those in other Eleocharis species, E. vivipara and E. retroflexa, which show C4 characteristics on land but C3 and C4 characteristics under water. The terrestrial form of E. baldwinii exhibited a C4‐like pattern of enzyme localization. The submerged form exhibited a modified anatomy with well‐developed mesophyll cells and small Kranz cells. The C4 enzyme levels declined conspicuously in outer mesophyll cells adjacent to the epidermis, whereas Rubisco levels increased throughout the mesophyll in the submerged form. These results suggest that intermediate photosynthesis between C3 and C4 photosynthesis in the submerged form results from the predominant operation of the C3 pathway in the outer mesophyll cells and the C4 pathway in both the inner mesophyll and Kranz cells. Differences in the degree of C4 expression in terrestrial forms of Eleocharis species may cause the differences in the expression of photosynthetic modes under water.
Sites of actin filament initiation and reorganization in cold‐treated tobacco cells
Authors: POKORNÁ J. , SCHWARZEROVÁ K. , ZELENKOVÁ S. , PETRÁŠEK J. , JANOTOVÁ I. , ČAPKOVÁ V. , OPATRNÝ Z. 
Published: May 2004

ABSTRACTCytoskeletal proteins assemble into dynamic polymers that play many roles in nuclear and cell division, signal transduction, and determination of cell shape and polarity. The distribution and dynamics of microtubules (MTs) and actin filaments (AFs) are determined, among other factors, by the location of their nucleation sites. Whereas the sites of microtubule nucleation in plants are known to be located under the plasma membrane and on the nuclear envelope during interphase, there is a striking lack of information about nucleation sites of AFs. In the studies reported herein, low temperature (0 °C) was used to de‐polymerize AFs and MTs in tobacco BY‐2 (Nicotiana tabacum L.) cells at interphase. The extent of de‐polymerization of cytoskeletal filaments in interphase cells during cold treatment and the subcellular distribution of nucleation sites during subsequent recovery at 25 °C were monitored by means of fluorescence microscopy. The results show that AFs re‐polymerized rapidly from sites located in the cortical region and on the nuclear envelope, similarly to the initiation sites of MTs. In contrast to MTs, however, complete reconstitution of AFs was preceded by the formation of transient actin structures including actin dots, rods, and filaments with a dotted signal. Immunoblotting of soluble and sedimentable protein fractions showed no changes in the relative amounts of free and membrane‐bound actin or tubulin.
The Effects of Density on the Learned Recognition of Heterospecific Alarm Cues
Authors: Pollock Michael S. , Chivers Douglas P. 
Published: May 2004

AbstractNumerous species, both aquatic and terrestrial, use alarm cues to mediate predation risk. These cues may be either intentionally or inadvertently released, and may be received by either conspecifics or heterospecifics. In aquatic systems, alarm cues are often chemical in nature and are released when an organism is disturbed or damaged by a predator. In some cases the recognition of alarm cues from conspecifics, or closely related heterospecifics, is innate, while the recognition of alarm cues from distantly related species must be learned. Many studies have documented the use of heterospecific alarm cues, but few have explored the manner in which these cues come to be recognized as an indication of predation. In the current study, we examined the fathead minnow (Pimephales promelas)/brook stickleback (Culaea inconstans) alarm system. We tested the effect of density on the ability of minnows to learn to recognize stickleback alarm cues as a threat. We hypothesized that the ability of minnows to learn to recognize stickleback alarm cues should increase with increasing stickleback density because there would be more opportunity for minnows to associate the heterospecific alarm cue with the threat. To test this hypothesis we stocked minnows into large outdoor pools with no stickleback, low numbers of stickleback, or high numbers of stickleback. All pools contained a predator (pike, Esox lucius) known to the minnows. Following a 14 d conditioning period, minnows were tested for a response to skin extract from stickleback, minnow, and an unknown heterospecific (swordtail, Xiphophorus helleri). Minnows from pools with large numbers of stickleback learned to respond to stickleback alarm cues while minnows from pools with low numbers of stickleback, or no stickleback, did not.
Female Preferences for Sailfin and Body Size in the Sailfin Molly, Poecilia latipinna
Authors: MacLaren R. David , Rowland William J. , Morgan Nicole 
Published: May 2004

AbstractWe tested the mating preference of female sailfin mollies (Poecilia latipinna) by presenting them with pairs of dummy males differing in: (I) sailfin and body size together (holding sailfin : body size ratio constant); (II) body size alone (holding sailfin size constant); (III) sailfin size alone (holding body size constant); and (IV) sailfin : body size ratio (holding total lateral projection area constant). Females spent more time near dummies of greater sailfin or greater body size. The preference functions based on the first three sets of stimuli showed a similar pattern: the preference between any two simultaneously presented dummies increased with the magnitude of the discrepancy in lateral projection area (LPA) between them. However, when LPA was held constant in expt (IV), neither body size, sailfin size, nor any particular dummy (i.e. any particular sailfin + body size combination) was preferred. These findings suggest that increased LPA is more stimulating to sexually receptive females and that females consequently prefer larger males. The sailfin may therefore have evolved as a way for males to exploit this sensory bias and appear larger to prospective mates.
Medication management by graduate nurses: Before, during and following medication administration
Authors: Manias Elizabeth , Aitken Robyn , Dunning Trisha 
Published: May 2004

AbstractThe purpose of the present study was to explore graduate nurses’ perceptions of their medication management activities in the acute care context. A qualitative research design with a semistructured interview schedule was used to elicit information from participants. The sampling population consisted of graduate nurses involved in direct patient care in medical and surgical wards of a Melbourne metropolitan teaching hospital, completing a graduate nurse program. Twelve graduate nurses participated in the interviews. Two major themes emerged: (i) monitoring medications and (ii) interventions for patient care. The findings indicate that graduate nurses are required to address several facets of the medication management role in their daily practice. It is pertinent to examine ward dynamics to ensure that graduate nurses have ready access to experienced health care professionals. Through collegial support, graduate nurses should also be encouraged to critically examine the different possibilities when making clinical judgments about monitoring patient medications.
Parents’ experiences of asthma: Process from chaos to coping
Authors: Trollvik Anne , Severinsson Elisabeth 
Published: May 2004

AbstractThe aim of the present qualitative study was to describe nine parents’ everyday experiences of living with a child suffering from asthma. Data were collected by means of in‐depth interviews and phenomenological content analysis. Four main themes emerged: feelings of uncertainty, helplessness and guilt; the need for support and help from healthcare professionals; adaptation to everyday life; and the development of coping strategies. In addition, two subthemes; trying out and seeking information, emerged. Trying out was found to be an important strategy for parents in managing the illness. In encounters with healthcare professionals, parents felt that they were not respected and that their competence was questioned. In conclusion, this study emphasizes the importance of a mutual dialogue between healthcare professionals and parents to enable the parents to develop the competence necessary to care for their child.
Together we are heard: Effectiveness of daily ‘language’ groups in a community preschool
Authors: Hodge Telêri , Downie Jill 
Published: May 2004

AbstractStrong oral language skills are a prerequisite for successful literacy and there is a strong interdependence between oral language acquisition and emergent literacy development. Ramifications of this are that children with language impairments are at great risk for difficulties in learning to read and write, with problems often persisting throughout the school years into adulthood. The Together we are heard program involved improving each child's oral language skills through group sessions facilitated by a speech pathologist on a daily basis at preschool. The aim of the present research was to determine the effectiveness of the program to identify the best way to assist children to develop appropriate language skills. The study showed that the children improved significantly in all four levels of the Preschool Language Assessment Inventory (PLAI). Importantly, the program was effective for both genders and there was no difference in the success of Indigenous children when compared to their European counterparts. There is a strong recommendation for further research and to expand such programs, particularly in areas that target children from impoverished and deprived environmental backgrounds.
Hand dermatitis among female nursing students in tropical Australia
Authors: Smith Derek R. , Leggat Peter A. 
Published: May 2004

AbstractAlthough hand dermatitis is known to affect nursing students worldwide, the prevalence among their Australian counterparts has not been elucidated and the relative contribution of tropical environments is unclear. Therefore, we conducted the first investigation of hand dermatitis among 232 female, undergraduate nurses in tropical Australia using a previously validated methodology. Hand dermatitis prevalence rose from 10.8% in the first year to 27.4% by the third year and averaged 18.5% across all three grades. Pre‐existing atopic dermatitis caused a 7.8‐fold risk increase during logistic regression analysis (odds ratio [OR] 7.8, 95% confidence interval [CI] 3.0–21.1, P < 0.0001). Overall, this study suggests that hand dermatitis is less common among tropical Australian nursing students than their counterparts around the world. The identification of atopic dermatitis as a hand dermatitis risk factor was, however, consistent with previous research conducted in non‐tropical areas.
Assessments and nursing care for right brain‐damaged stroke patients: Focusing on neglect and related symptoms
Authors: Ohshima Hiroko , Murashima Sachiyo , Takahashi Ryutaro 
Published: May 2004

AbstractThe purpose of present study was to identify the behavioural characteristics and examine assessments of nursing care among right brain‐damaged stroke patients with neglect within 1 year following initial onset. Characteristics related to higher cerebral dysfunction were extracted and patient grouping was attempted through cognition (Mini‐Mental State Examination) and physical function (Barthel Index) plots. The characteristics and implications for nursing care for each group were analyzed. Twelve patients were classified into four groups using cognitive‐physical function evaluations together with subjective and objective data associated with neglect. ‘Neglect’ has been regarded as a disorder of spatial perception. However, the characteristics observed in Group 2 suggest that ‘neglect’ may have another facet, manifesting as disorders in perceiving continuous spatio‐temporal changes of an action and comprehending the context of a situation. In these patients, although ‘by calling attention’ is the conventional care, more appropriate care should be provided based on an assessment of cognitive‐physical function and spatio‐temporal recognition of an action.
Living with Huntington's disease: Need for supportive care
Authors: Dawson Sky , Kristjanson Linda J. , Toye Christine M. , Flett Penny 
Published: May 2004

AbstractHuntington's disease is a genetic, neurological disorder characterized by mid‐life onset, involuntary movements, cognitive decline, behavioral disturbance, and inexorable progression. The impact of Huntington's disease is devastating for individuals and their families as it is a disease with a long trajectory; many young people are aware that they may develop the illness for years before there are obvious symptoms. There is therefore ample opportunity to plan and choreograph the care and supportive services for people with Huntington's disease and their families. The present study was conducted to explore the needs for palliative (supportive) care service provision of people with Huntington's disease and their families/informal carers. Six people with the disease, 19 informal carers and seven health care workers with specialized knowledge took part in individual, semistructured interviews, which were analyzed thematically. Themes were: (i) adjusting to the impact of the illness; (ii) surviving the search for essential information; (iii) gathering practical support from many sources; (iv) bolstering the spirit; (v) choreographing individual care and; (vi) fearing the future. Our findings demonstrate that palliative care services for people with Huntington's disease and their informal carers need to provide expert psychological and practical support and perhaps most importantly, be flexible, adequately planned and choreographed.
Ethical concerns: Comparison of values from two cultures
Authors: Wros Peggy L. , Doutrich Dawn , Izumi Shigeko 
Published: May 2004

AbstractThe present study was a secondary analysis of data from two phenomenological studies of nurses in the USA and Japan. The study incorporated hermeneutics and feminist methodologies to answer the following questions. Are there common values and ethical concerns and values within the nursing cultures of Japan and the USA? What are some commonalities and differences between Japanese nurses’ ethical concerns and those of American nurses? Findings indicated that nurses from the USA and Japan share common values and ethical concerns as professional nurses, including competence, respect for the patient as a person, responsibility, relationship and connection, importance of the family, caring, good death, comfort, truth‐telling, understanding the patient/situation, and anticipatory care. Although ethical concerns are similar, related background meanings and actions often look different between cultures; truth‐telling is described as an example. Nurses in each country also hold unique values not found in the nursing practice of the other country. Understanding these commonalities and differences is critical for the development of global nursing ethics.
Impact of in‐depth interviews on the interviewer: Roller coaster ride
Authors: Beale Barbara , Cole Rose , Hillege Sharon , McMaster Rose , Nagy Sue 
Published: May 2004

AbstractThe authors investigated the experiences of parents with children/adult children in metropolitan Sydney, Australia who were living with, or had recovered from, an eating disorder. During regular team meetings, the research assistant who conducted the interviews had described her reactions which led the research team to investigate her experience in more depth. The aim of the present paper was to explore the impact on the research assistant who conducted 22 in‐depth interviews with the parents. One of the members of the research team interviewed the research assistant to elicit her reactions. The interview was content analyzed and the following themes were identified: (i) appreciation of an egalitarian model of research; (ii) the emotions expressed by the research assistant; (iii) making sense of the inexplicable and (iv) reflections and comparison to her own life role. The research team would like to advance the theory that the adoption of a formal debriefing mechanism be integrated into the qualitative research process.