bluuebunny/crossref_metadata_2025 huggingface dataset:
Meta‐synthesis of presence in nursing
Authors: Finfgeld‐Connett Deborah
Published: July 2006

Aim. This paper reports a meta‐synthesis of the concept of presence.

Background. Presence is a complex concept that is vague and poorly defined. It is often confused with other concepts such as caring, empathy, therapeutic use of self, support and nurturance. Adding to this confusion is the fact that presence has been fragmented into numerous types, used indiscriminately and combined with other concepts such as caring.

Method. The nursing literature was searched using thecinahl, Dissertation Abstracts and Missouri Bibliographic Information User System databases and the keywords presence, concept analysis, qualitative studies, grounded theory, phenomenology and ethnography. The reference lists of the sources were also scrutinized. Four linguistic concept analyses and 14 qualitative studies of presence were identified and a meta‐analysis was conducting using these.

Findings. Presence is an interpersonal process that is characterized by sensitivity, holism, intimacy, vulnerability and adaptation to unique circumstances. It consists of a process in which patients demonstrate a need for and openness to presence. In turn, nurses must be willing to enact presence and practice within an environment that is conducive to it. Nurses must also possess personal and professional maturity and base their practice on moral principles of commitment and respect for individual differences. The process results in enhanced mental well‐being for nurses and patients and improved physical well‐being for patients. In keeping with the nature of a process, the consequences of presence go on to influence its future enactment.

Conclusion. Advanced concept analysis methods should be used to further explicate presence and differentiate it from other nursing constructs. Until this is done, scholars are cautioned against parsing the term and combining it with vaguely defined nursing concepts such as caring. Researchers are urged to consider how presence can be preserved using tele‐health technology and in time‐sensitive healthcare settings.
Development of the combined assessment of residential environments (CARE) profiles
Authors: Faulkner Mark , Davies Sue , Nolan Mike , Brown‐Wilson Christine
Published: July 2006

Aim.  This paper reports the development and initial testing of the combined assessment of residential environments (CARE) profiles, which identify the frequency of positive events over a specified time based on the perceptions of residents, relatives and staff in care home settings.

Background.  Despite the well‐known benefits of positive events for subjective well‐being, little is known about the nature of positive events experienced by residents, relatives and staff in care homes. There is also a dearth of tools capable of systematically evaluating how frequently these events occur in this context.

Methods.  The CARE profiles were developed and tested between February 2004 and June 2005 with a combined sample of 372 residents, relatives and staff drawn from 11 care homes. An Event Frequency Approach was adopted to create three questionnaires (residents, relatives and staff), each containing 30 consensually valid positive events. The thematic content of these events was balanced for each questionnaire using the Senses Framework as a theoretical model. Once completed, the CARE profiles were tested in four care homes.

Results.  Test data from the CARE profiles were used to produce a bar chart showing median frequencies of positive events experienced by residents, relatives and staff during the timeframe in question (e.g. 1 month). These profiles were shown to be internally consistent, with alpha scores ranging from 0·70 to 0·89 for residents, 0·91 to 0·94 for relatives and 0·78 to 0·92 for staff.

Conclusion.  We envisage that feedback from the CARE profiles will both reinforce good care home practice and identify areas for change based on the experiences of all major stakeholders. However, further development of the profiles is needed if the experiences of cognitively impaired residents are to be included in the assessment process.
Odour‐mediated long‐range avoidance of interspecific competition by a solitary endoparasitoid: a time‐saving foraging strategy
Authors: TAMÒ CRISTINA , ROELFSTRA LISE‐LORE , GUILLAUME SUZANNE , TURLINGS TED C. J.
Published: July 2006

In studies on optimal foraging strategies, long‐range decisions in the pursuit of resource are rarely considered. This is also the case for sympatric parasitoids, which may be confronted with the decision to accept or reject host larvae that are already parasitized by a competing species. They can be expected to reject already parasitized hosts if it is likely that they will lose the resulting intrinsic competition. However, examples of such interspecific host discrimination are rare.

We propose that parasitoids that are not egg‐limited should reject inferior hosts only if it saves them time, and that this will be achieved mainly when the parasitoids are able to detect competitors from a distance. We tested this hypothesis using the sympatric parasitoids Cotesia marginiventris (Cresson) and Campoletis sonorensis (Cameron).

C. sonorensis was found to be the superior intrinsic competitor but, upon contact with a host larva, both wasps readily accepted hosts that had already been parasitized by the other species. However, in an olfactometer experiment, C. marginiventris females were found to strongly avoid the odour of their superior competitor.

These results are in accordance with a time optimization scenario, whereby the inferior competitor accepts competition if it costs only an egg, but avoids competition if it may save time that can be allocated to the search for more profitable hosts.

Models on host discrimination strategies in parasitoids had not yet considered discrimination from a distance. Long‐range foraging decisions can also be expected for other organisms that have to choose between resources of varying suitability and profitability.
Spatial variation in resistance and virulence in the host–pathogen system Salix triandra–Melampsora amygdalinae
Authors: NIEMI LENA , WENNSTRÖM ANDERS , HJÄLTÉN JOAKIM , WALDMANN PATRIK , ERICSON LARS
Published: July 2006

Host–pathogen interactions in isolated populations may result in the adaptation of pathogens to local hosts. However, results of earlier studies of local adaptation in plant–pathogen systems have been contradictory and it has been suggested that specific, species characteristics, for example distribution, dispersal and the degree of pathogen dependence on the host, are important for the outcome of host–pathogen interactions. In addition, the scale of the study may influence whether or not local adaptation is found.

We argue that local adaptation of the pathogen to the host can be expected in a system where: (i) the pathogen is host‐specific with a short generation time compared with the host; (ii) populations are isolated, allowing localized evolution to occur; and (iii) the study is performed on a geographical scale exceeding the maximum dispersal range of the interacting species.

To test these predictions we examined the within‐ and among‐population variation in resistance and virulence of the plant–pathogen system Salix triandra–Melampsora amygdalinae. The pathogen occurs throughout the whole distribution range of the host, and the area of interest consists of highly isolated, small natural populations.

Resistance and virulence differed both within and between populations and all clones showed a unique resistance pattern. We conclude that M. amygdalinae is locally adapted to the host S. triandra as all pathogen populations have a higher probability of infecting sympatric than allopatric hosts. Furthermore, high resistance in the host population was accompanied by a high virulence in the pathogen population, suggesting that high resistance levels in a host population may select for more virulent pathogen populations, or vice versa.

The nature of host–pathogen interactions differs among systems, and the dynamics of the interaction between S. triandra and M. amygdalinae is governed by characteristics that have resulted in the evolution of local adaptation.

Thus, when studying local adaptation of pathogens to their hosts it is important to consider the biology, as well as the scale of dispersal and spatial distribution of both host and pathogen.
Plant species and functional group effects on abiotic and microbial soil properties and plant–soil feedback responses in two grasslands
Authors: BEZEMER T. MARTIJN , LAWSON CLARE S. , HEDLUND KATARINA , EDWARDS ANDREW R. , BROOK ALEX J. , IGUAL JOSÉ M. , MORTIMER SIMON R. , VAN DER PUTTEN WIM H.
Published: July 2006

Plant species differ in their capacity to influence soil organic matter, soil nutrient availability and the composition of soil microbial communities. Their influences on soil properties result in net positive or negative feedback effects, which influence plant performance and plant community composition.

For two grassland systems, one on a sandy soil in the Netherlands and one on a chalk soil in the United Kingdom, we investigated how individual plant species grown in monocultures changed abiotic and biotic soil conditions. Then, we determined feedback effects of these soils to plants of the same or different species. Feedback effects were analysed at the level of plant species and plant taxonomic groups (grasses vs. forbs).

In the sandy soils, plant species differed in their effects on soil chemical properties, in particular potassium levels, but PLFA (phospholipid fatty acid) signatures of the soil microbial community did not differ between plant species. The effects of soil chemical properties were even greater when grasses and forbs were compared, especially because potassium levels were lower in grass monocultures.

In the chalk soil, there were no effects of plant species on soil chemical properties, but PLFA profiles differed significantly between soils from different monocultures. PLFA profiles differed between species, rather than between grasses and forbs.

In the feedback experiment, all plant species in sandy soils grew less vigorously in soils conditioned by grasses than in soils conditioned by forbs. These effects correlated significantly with soil chemical properties. None of the seven plant species showed significant differences between performance in soil conditioned by the same vs. other plant species.

In the chalk soil, Sanguisorba minor and in particular Briza media performed best in soil collected from conspecifics, while Bromus erectus performed best in soil from heterospecifics. There was no distinctive pattern between soils collected from forb and grass monocultures, and plant performance could not be related to soil chemical properties or PLFA signatures.

Our study shows that mechanisms of plant–soil feedback can depend on plant species, plant taxonomic (or functional) groups and site‐specific differences in abiotic and biotic soil properties. Understanding how plant species can influence their rhizosphere, and how other plant species respond to these changes, will greatly enhance our understanding of the functioning and stability of ecosystems.
Intact forests provide only weak resistance to a shade‐tolerant invasive Norway maple (Acer platanoides L.)
Authors: MARTIN PATRICK H. , MARKS PETER L.
Published: July 2006

Intact, closed canopied forests appear highly resistant to exotic plant invasions, but there are few experimental studies of this observation. To test this issue and explore the conditions that foster resistance, we experimentally added Norway maple (Acer platanoides L.) seeds to intact forests for 3 years and monitored emergence, survivorship and height growth for 5 years.

Seed additions (250 seeds−1 m2) were replicated in situ in combinations of light (deep shade vs. small gaps), soil fertility (NO3 and pH), and variation in soil moisture as influenced by topography (hill slopes vs. flat areas at slope bases) in five eastern deciduous forests in central New York and southern Connecticut. We then parameterized a model with this data to project long‐term rates of sapling recruitment.

Seedlings had high survival and low growth rates in the deep shade, suggesting that this species readily forms a seedling bank in intact forests. By age 5, annual survivorship reached 93% in deep shade and 98% in small gaps. Median seedling heights were ≤ 10 cm in all treatments after 5 years, though the largest seedlings were markedly taller in gaps. Mean year 5 densities of all experimental seedlings (ages 3–5 years) were 14 seedlings−1 m2 (± 2.4 SE) in the shade and 19 seedlings−1 m2 (± 3.5 SE) in small gaps.

While seedlings colonized in all conditions, resistance to invasion varied markedly; resistance was highest in deeply shaded, acidic conditions (pH < 4.5). Small gaps initially promoted invasion, but by age 4 shade survivorship rates were equivalent to gaps. Higher soil pH (especially > 6) also significantly increased survivorship, particularly in deep shade. Shading's main effect was to suppress height growth. Overall, the model predicted impressive sapling recruitment; even in deeply shaded, acidic conditions, approximately 1% of seeds emerge and survive to become saplings.

Intact forests only weakly resisted A. platanoides colonization, but strongly suppressed its rate of invasion. As such, the frequency of disturbance, though ultimately unnecessary for A. platanoides invasions, will strongly influence its near‐term invasiveness. Dispersal limitation and slow stand dynamics appear to be the primary constraints on its current distribution.
A Population of Non‐Luteinising Hormone/Non‐Adrenocorticotrophic Hormone‐Positive Cells in the Male Rat Anterior Pituitary Responds Mitotically to Both Gonadectomy and Adrenalectomy
Authors: Nolan L. A. , Levy A.
Published: July 2006

The male rat anterior pituitary responds highly reproducibly to specific hormonal stimuli in terms of the extent and timing of mitotic and apoptotic (trophic) activity. The principal objective of the present study was to define the contribution of hormonally identifiable cells to the trophic responses to bilateral gonadectomy and bilateral adrenalectomy. The patterns of pituitary mitotic responses to adrenalectomy and gonadectomy are similar in amplitude and duration. When adrenalectomy and gonadectomy are combined, the amplitude of the pituitary mitotic response is unchanged. That is, the trophic stimuli are not additive. Dexamethasone‐induced apoptosis in nascent cells is amplified not only by recent adrenalectomy, but also, and to an almost identical extent, by gonadectomy. Combining adrenalectomy and gonadectomy does not further enhance the size of the apoptotically‐responsive cell population. Dual bromodeoxyuridine and adrenocorticotrophic hormone (ACTH) or luteinising hormone (LH) immunolabelling showed that more than 95% of all dividing cells are not and do not become positive for either of these hormones during the period of peak mitotic response. Following adrenalectomy, most newly‐formed ACTH cells are derived from differentiation of pre‐existing hormonally undifferentiated cells. Despite an overall increase in mitotic activity, there is no measurable increase in the number of LH immunopositive cells after gonadectomy. The nonadditive pituitary mitotic and apoptotic responses to adrenalectomy and gonadectomy strongly suggest that the same progenitor cell population responds mitotically to both. This weakens the prevailing view that hormonally identifiable cells with specific trophic profiles contribute significantly to pituitary cell subpopulation revision.
Pituitary Transcription Factors: From Congenital Deficiencies to Gene Therapy
Authors: Quentien M. H. , Barlier A. , Franc J. L. , Pellegrini I. , Brue T. , Enjalbert A.
Published: July 2006

Despite the existence of interspecies phenotypic variability, animal models have yielded valuable insights into human pituitary diseases. Studies on Snell and Jackson mice known to have growth hormone, prolactin and thyroid‐stimulating hormone deficiencies involving the hypoplastic pituitary gland have led to identifying alterations of the pituitary specific POU homeodomain Pit‐1 transcription factor gene. The human phenotype associated with rare mutations in this gene was found to be similar to that of these mice mutants. Terminal differentiation of lactotroph cells and direct regulation of the prolactin gene both require interactions between Pit‐1 and cell type specific partners, including panpituitary transcriptional regulators such as Pitx1 and Pitx2. Synergistic activation of the prolactin promoter by Pitx factors and Pit‐1 is involved not only in basal condition, but also in responsiveness to forskolin, thyrotrophin‐releasing‐hormone and epidermal growth factor. In corticotroph cells, Pitx1 interacts with Tpit. Tpit mutations have turned out to be the main molecular cause of neonatal isolated adrenocorticotrophin deficiency. This finding supports the idea that Tpit plays an essential role in the differentiation of the pro‐opiomelanocortin pituitary lineage. The effects of Pit‐1 are not restricted to hormone gene regulation because this factor also contributes to cell division and protects the cell from programmed cell death. Lentiviral vectors expressing a Pit‐1 dominant negative mutant induced time‐ and dose‐dependent cell death in somatotroph and lactotroph adenomas in vitro. Gene transfer by lentiviral vectors should provide a promising step towards developing an efficient specific therapeutic approach by which a gene therapy programme for treating human pituitary adenomas could be based.
Estimates of relatedness in groups of humpback whales (Megaptera novaeangliae) on two wintering grounds of the Southern Hemisphere
Authors: POMILLA CRISTINA , ROSENBAUM HOWARD C.
Published: July 2006

Group formation in humpback whales has been described in relation to different components of the migratory cycle, yet it is debated whether such groups represent real social bonding or ephemeral aggregations. Cooperative behaviours are exhibited during feeding activities, and it has been suggested that males may cooperate during competition for mates. Since most cooperative behaviours are expected to originate among kin, genetic relatedness represents a critical variable in the understanding of any social phenomenon, especially when cooperation cannot be confirmed unequivocally. Using an approach combining multi‐locus microsatellite genotyping and several genetic relatedness estimators, we analyzed whale associations for two different wintering grounds in the Southern Hemisphere. The analyses included 648 whales sampled from 292 groups off the coast of Gabon and Northeast Madagascar, and screened for eleven microsatellite loci. Through simulations, we assessed the performance of three pairwise relatedness estimators. The individuals were molecularly sexed and their associations were investigated in the context of sex and group type. No significant association among relatives was found with the exception of mother–offspring pairs, supporting previous indications of extended maternal care. The analysis from the Gabon population also suggests that related males may avoid each other during competitive activities. Our results demonstrate that if cooperative behaviours occur on wintering grounds they are not favoured by kin selection.
Farmers’ use of wild relative and sexual reproduction in a vegetatively propagated crop. The case of yam in Benin
Authors: SCARCELLI N. , TOSTAIN S. , VIGOUROUX Y. , AGBANGLA C. , DAÏNOU O. , PHAM J.‐L.
Published: July 2006

The impact of traditional farmers’ management on genetic diversity of vegetatively propagated crops is poorly documented. In this study, we analysed the impact of ennoblement of spontaneous yams, an original traditional farmers’ practice, on the genetic diversity of yam (Dioscorea sp.) in Benin. We used 11 microsatellite markers on yam tubers from a small village in northern Benin and demonstrated that wild × cultivated hybrids are spontaneously formed. Many of the spontaneous yams collected by farmers from surrounding savannah areas for ennoblement were shown to be of wild and hybrid genotypes. Moreover, we demonstrated that some yam varieties have a wild or hybrid signature. Lastly, we performed a broader ranging genetic analysis on yam material from throughout Benin and showed that this practice is used in different ecological and ethno‐linguistic regions. Through this practice, farmers create new varieties with new genetic combinations via sexual reproduction of wild and cultivated yams. This system, whereby a sexual cycle and asexual propagation are mixed, ensures potential large‐scale cultivation of the best genotypes while preserving the potential for future adaptation.
A novel high‐throughput genetic screen for stress‐responsive mutants of Arabidopsis thaliana reveals new loci involving stress responses
Authors: Rama Devi S. , Chen Xi , Oliver David J. , Xiang Chengbin
Published: July 2006

Activation sequence‐1 (as‐1) cognate promoter elements are widespread in the promoters of plant defense‐related genes as well as in plant pathogen promoters, and may play important roles in the activation of defense‐related genes. The as‐1‐type elements are highly responsive to multiple stress stimuli such as jasmonic acid (JA), salicylic acid (SA), H2O2, xenobiotics and heavy metals, and therefore provide a unique opportunity for identifying additional signaling components and cross‐talk points in the various signaling networks. A single as‐1‐type cis‐element‐driven GUS reporter Arabidopsis line responsive to JA, SA, H2O2, xenobiotics and heavy metals was constructed for mutagenesis. A large‐scale T‐DNA mutagenesis has been conducted in the reporter background, and an efficient high‐throughput mutant screen was established for isolating mutants with altered responses to the stress chemicals. A number of mutants with altered stress responses were obtained, some of which appear to identify new components in the as‐1‐based signal transduction pathways. We characterized a mutant (Δ8L4) with a T‐DNA insertion in the coding sequence of the gene At4g24275. The as‐1‐regulated gene expression and GUS reporter gene expression were altered in the Δ8L4 mutant, but there was no change in the expression of genes lacking as‐1 elements in their promoters. The phenotype observed with the Δ8L4 mutant was further verified using RNAi plants for At4g24275 (8L4‐RNAi), suggesting the feasibility of use of this high‐throughput mutant screening in isolating stress‐signaling mutants.
Diverse phosphoregulatory mechanisms controlling cyclin‐dependent kinase‐activating kinases in Arabidopsis
Authors: Shimotohno Akie , Ohno Ryoko , Bisova Katerina , Sakaguchi Norihiro , Huang Jirong , Koncz Csaba , Uchimiya Hirofumi , Umeda Masaaki
Published: July 2006

For the full activation of cyclin‐dependent kinases (CDKs), not only cyclin binding but also phosphorylation of a threonine (Thr) residue within the T‐loop is required. This phosphorylation is catalyzed by CDK‐activating kinases (CAKs). In Arabidopsis three D‐type CDK genes (CDKD;1–CDKD;3) encode vertebrate‐type CAK orthologues, of which CDKD;2 exhibits high phosphorylation activity towards the carboxy‐terminal domain (CTD) of the largest subunit of RNA polymerase II. Here, we show that CDKD;2 forms a stable complex with cyclin H and is downregulated by the phosphorylation of the ATP‐binding site by WEE1 kinase. A knockout mutant of CDKD;3, which has a higher CDK kinase activity, displayed no defect in plant development. Instead, another type of CAK – CDKF;1 – exhibited significant activity towards CDKA;1 in Arabidopsis root protoplasts, and the activity was dependent on the T‐loop phosphorylation of CDKF;1. We propose that two distinct types of CAK, namely CDKF;1 and CDKD;2, play a major role in CDK and CTD phosphorylation, respectively, in Arabidopsis.
A simple in vitro RNA editing assay for chloroplast transcripts using fluorescent dideoxynucleotides: distinct types of sequence elements required for editing of ndh transcripts
Authors: Sasaki Tadamasa , Yukawa Yasushi , Wakasugi Tatsuya , Yamada Kyoji , Sugiura Masahiro
Published: July 2006

RNA editing is found in various transcripts from land plant chloroplasts. In tobacco chloroplasts, C‐to‐U conversion occurs at 36 specific sites including two sites identified in this work. Our RNA editing assay system using chloroplast extracts facilitated biochemical analyses of editing reactions but required mRNAs labeled with 32P at specific sites. Here, we have improved the in vitro system using fluorescence‐labeled chain terminators, ddGTP and ddATP, and have measured the editing activity at 19 sites in ndh transcripts. Editing activities varied from site to site. It has been reported that one editing site in ndhA mRNAs is present in spinach but absent in tobacco, but a corresponding editing capacity had been found in vivo in tobacco using biolistic transformation. We confirmed biochemically the existence of this activity in tobacco extracts. Using the non‐radioactive assay, we examined sequences essential for editing within a 50‐nt mRNA region encompassing an editing site. Editing of the ndhB‐2 site requires a short sequence in front of the editing site, while that of the ndhF mRNA requires two separate regions, a sequence surrounding the editing site and a 5′ distal sequence. These results suggest that distinct editing mechanisms are present in chloroplasts.
Mycosphaerella species associated with leaf disease of Eucalyptus globulus in Ethiopia
Authors: Gezahgne Alemu , Roux J. , Hunter G. C. , Wingfield M. J.
Published: July 2006

Eucalyptus spp. are among the most widely planted exotic trees in Ethiopia. Several damaging leaf pathogens are known from Eucalyptus spp. worldwide. Of these, Mycosphaerella spp. are among the most important, causing the disease known as Mycosphaerella leaf disease (MLD). Characteristic symptoms of MLD include leaf spot, premature defoliation, shoot and twig dieback. Recent disease surveys conducted in Ethiopian Eucalyptus plantations have revealed disease symptoms similar to those caused by Mycosphaerella spp. These symptoms were restricted to E. globulus trees growing in several localities in south, south western and western Ethiopia. The aim of this study was to identify the fungi associated with this disease. This was achieved by examining ascospore germination patterns, anamorph associations and sequence data from the Internal Transcribed Spacer (ITS) region of the rRNA operon, for representative isolates. Several different ascospore germination patterns were observed, suggesting that more than one species of Mycosphaerella is responsible for MLD on E. globulus in Ethiopia. Analysis of sequence data showed that three Mycosphaerella spp., M. marksii, M. nubilosa and M. parva were present. This is the first report of these three species from Ethiopia and represents a valuable basis on which to build further studies in the region.
Polymorphism and chromosomal localization of the porcine signal transducer and activator of transcription 5B gene (STAT5B)
Authors: Ballester M. , Sardina M.T. , Folch J.M.
Published: July 2006

Signal transducers and activators of transcription (STATs) are a family of transcription factors. STAT5A and 5B are two highly related proteins encoded by two distinct genes. Transgenic knockout mice studies have indicated the importance of STAT5 proteins for the regulation of both lactation and growth performance. Moreover, different studies determine the role of STAT5 proteins in the modulation of adipocyte function. In this study, we sequenced one fragment of STAT5B gene from animals of six breeds (Duroc, Iberian, Landrace, Large White, Piétrain and Meishan) to identify genetic variants. A G/A single nucleotide polymorphism in intron 14 creates a polymorphic PstI restriction site and was genotyped by polymerase chain reaction restriction fragment length polymorphism in the six breeds. Allele G was only present in Large White, Piétrain and Meishan populations, detecting only G allele in this last pig breed. The STAT5B gene was located by radiation hybrid mapping to porcine chromosome 12, within the confidence interval for the fatty acid composition quantitative trait loci, previously identified in an Iberian × Landrace cross.
Strategy for applying genome‐wide selection in dairy cattle
Authors: Schaeffer L.R.
Published: July 2006

Animals can be genotyped for thousands of single nucleotide polymorphisms (SNPs) at one time, where the SNPs are located at roughly 1‐cM intervals throughout the genome. For each contiguous pair of SNPs there are four possible haplotypes that could be inherited from the sire. The effects of each interval on a trait can be estimated for all intervals simultaneously in a model where interval effects are random factors. Given the estimated effects of each haplotype for every interval in the genome, and given an animal's genotype, a ‘genomic’ estimated breeding value is obtained by summing the estimated effects for that genotype. The accuracy of that estimator of breeding values is around 80%. Because the genomic estimated breeding values can be calculated at birth, and because it has a high accuracy, a strategy that utilizes these advantages was compared with a traditional progeny testing strategy under a typical Canadian‐like dairy cattle situation. Costs of proving bulls were reduced by 92% and genetic change was increased by a factor of 2. Genome‐wide selection may become a popular tool for genetic improvement in livestock.
Effect of supplemental yeast culture and sodium bicarbonate on ruminal fermentation and blood variables in rams
Authors: Galıp Nurten
Published: July 2006

A trial was conducted to evaluate the effect of sodium bicarbonate (BC) and Saccharomyces cerevisiae, live yeast culture (yea sacc1026, YS) on ruminal fermentation and blood variables. Four Kivircik rams with ruminal cannula were used in a Latin square design, during 27‐day periods (20 days for adaptation and 7 days for collection). They received 0 (control group), 5 g/day (i.e. 25 × 109 CFU) of YS or 10 g/day of sodium BC or 10 g/day of BC and 5 g/day of YS (BC + YS) (treatment groups). The cultures and sodium BC were added to the ration in a grain mix. The ration consisted of 70% grain mix and 30% lucerne hay. Rumen contents were collected before and 3 h and 6 h after morning feeding on days 1 and 7 in each collection period and were analyzed. Blood samples were also collected on the same days. Ruminal pH at 3 h (p ≤ 0.1) and 6 h (p ≤ 0.05) after feeding were higher when rams were fed BC and BC + YS than when they were fed CG and YS. Addition of YS to the diet did not modify the proportions of the different protozoa types; only Diplodinium at 0 h tended to be lower (p < 0.1) when rams were fed YS, BC and BC + YS than when they were fed CG. Plasma sodium value decreased by YS and BC + YS. Other biochemical and haematological variables were not affected by treatments. Also total volatile fatty acid, NH3‐N concentrations and protozoa counts in the ruminal fluid were not affected by treatments.
Effects of copper, zinc and selenium status on performance and health in commercial dairy and beef herds: retrospective study
Authors: Enjalbert F. , Lebreton P. , Salat O.
Published: July 2006

A retrospective study using analysis of plasma copper and zinc, and erythrocyte glutathione peroxidase from 2 080 dairy and beef cow herds was conducted to evaluate the relationship between trace‐element status and production, reproduction and health in cows and their calves. Classification of the herd status as deficient, marginal, low‐adequate or high‐adequate was based on the lower tercile of individual values. Odds ratios for each disorder in herds were calculated by multivariable stepwise logistic regression. Inadequate copper status was not associated with adult disorders, but was an important risk factor for poor calf performance or health. Selenium deficient status was associated with most studied disorders in cows, and both deficient and marginal herd status were strongly associated with poor health of calves, particularly with increased risks of myopathy and infectious diseases. Zinc insufficiency was strongly associated with low milk production and impaired locomotion in dairy herds, and was also associated with diarrhoea and poor growth in calves. Because a low‐adequate status increased the risk of many disorders in adults and calves, we propose to classify herds as deficient and marginal when the lower terciles of plasma zinc concentration are below 12 and between 12 and 14 μmol/l respectively.
Neurotensin antagonist acutely and robustly attenuates locomotion that accompanies stimulation of a neurotensin‐containing pathway from rostrobasal forebrain to the ventral tegmental area
Authors: Reynolds Sheila M. , Geisler Stefanie , Bérod Anne , Zahm Daniel S.
Published: July 2006

Neurotensin exerts complex effects on the mesolimbic dopamine system that alter motivation and contribute to neuroadaptations associated with psychostimulant drug administration. Activation of abundant neurotensin receptors in the ventral tegmental area (VTA) enhances dopamine neuron activity and associated release of dopamine in the nucleus accumbens (Acb) and cortex. In view of recent anatomical studies demonstrating that 70% of all neurotensin‐containing neurons projecting to the VTA occupy the lateral preoptic area–rostral lateral hypothalamus (LPH) and lateral part of the medial preoptic area (MPOA), the present study examined functionality in the LPH–MPOA neurotensinergic pathway in the rat. Disinhibition (resulting ultimately in stimulation‐like effects) of LPH–MPOA neurons with microinjected bicuculline (50 or 100 ng in 0.25 µL) produced locomotor activation that was considerably attenuated by systemic administration of the neurotensin antagonist SR 142948 A (0.03 and 0.1 mg/kg). In contrast, locomotion elicited in this manner was completely blocked by SR 142948 A infused directly into the VTA (5.0 and 15.0 ng in 0.25 µL). Baseline locomotion was unaffected by systemic or intra‐VTA administration of SR 142948 A and LPH–MPOA‐elicited locomotion was unaffected by infusion of SR 142948 A into the substantia nigra pars compacta and sites rostral and dorsal to the VTA. Locomotion was not elicited by infusions of bicuculline into the lateral hypothalamus at sites caudal to the LPH–MPOA, where neurotensin neurons projecting to the VTA are fewer. The results demonstrate the capacity of a neurotensin‐containing pathway from LPH–MPOA to VTA to modulate locomotion. This pathway may be important in linking hippocampal and mesolimbic mechanisms in normal behaviour and drug addiction.
Altered emotional behavioral responses in mice lacking brain‐type fatty acid‐binding protein gene
Authors: Owada Yuji , Abdelwahab Soha Abdelkawi , Kitanaka Noriko , Sakagami Hiroyuki , Takano Hiroshi , Sugitani Yoshinobu , Sugawara Minoru , Kawashima Hiroshi , Kiso Yoshinobu , Mobarakeh Jalal Izadi , Yanai Kazuhiko , Kaneko Kenya , Sasaki Hiroshi , Kato Hiroshi , Saino‐Saito Sachiko , Matsumoto Nozomu , Akaike Norio , Noda Tetsuo , Kondo Hisatake
Published: July 2006

Brain‐type fatty acid‐binding protein (B‐FABP) belongs to a family of intracellular lipid‐binding proteins. B‐FABP exhibits a binding affinity to long‐chain fatty acids (FAs) whose effects on brain functions including development, emotion, learning and memory have been proposed. B‐FABP is localized in the ventricular germinal cells in embryonic brain and astrocytes in developing and mature brain of rodents. In the present study we generated the mouse harboring a null mutation in the B‐FABP gene and studied its phenotype. B‐FABP mutant mice exhibited the enhanced anxiety and increased fear memory as well as the decreased content of docosahexaenoic acid (DHA) in their brain during the neonatal period without detection of any histological changes in the brain. In the adult brain, B‐FABP was localized more numerously to the astrocytes in the amygdala and septal area than to those in the hippocampal area. Analysis of FA content in the amygdala of adult brain revealed that arachidonic and palmitic acids increased significantly in the mutant mice compared with wild‐type. Furthermore, the response of N‐methyl‐d‐aspartate receptor‐mediated current to DHA in isolated neurons from B‐FABP mutant brain was significantly decreased compared with that of wild‐type, while no significant differences were detected in behavioral responses related to the spatial learning/memory or in the hippocampal long‐term potentiation. These data indicate that B‐FABP is crucially involved in the fear memory and anxiety through its binding with FAs and/or its own direct effects on pertinent metabolism/signaling of FAs.
Progesterone reverses the spatial memory enhancements initiated by tonic and cyclic oestrogen therapy in middle‐aged ovariectomized female rats
Authors: Bimonte‐Nelson Heather A. , Francis Kevin R. , Umphlet Claudia D. , Granholm Ann‐Charlotte
Published: July 2006

While some research has indicated that ovarian hormone therapy (HT) benefits memory and decreases risk of Alzheimer's disease in menopausal women, several newer studies have shown null or detrimental effects. Despite the null and negative cognitive findings, the numerous studies showing positive effects beg the question of what factors determine whether HT acts as a neuroprotectant or a risk factor for brain functioning. Using middle‐aged female rats, we directly compared six HTs. We evaluated the effects of ovariectomy, tonic low‐dose, tonic high‐dose and biweekly cyclic estradiol treatment, as well as whether progesterone altered the effectiveness of any one of these oestrogen regimens. Animals were tested on spatial and complex cued (intramaze patterns) reference memory using variants of the Morris maze. The tonic low‐dose and cyclic estradiol treatments improved spatial performance, while the addition of progesterone reversed these beneficial cognitive effects of estradiol. Additionally, all groups learned to locate the platform on the cued task; however, an egocentric circling strategy was used with sham ovary‐intact and hormone‐replacement groups showing the most efficient search strategy. Although the question of memory retention 8 weeks after the first cognitive assessment was addressed, a large number of animals died between the first and second test, rendering the retest uninterpretable for many group comparisons. Specifically, both doses of tonic estradiol dramatically increased the number of deaths during the 17‐week experiment, while the cyclic estradiol treatment did not. Progesterone decreased the number of deaths due to tonic estradiol treatment. Our findings suggest that the dose of estradiol replacement as well as the presence of progesterone influences the cognitive outcome of estradiol treatment. Further, there appears to be a dissociation between HT effects on cognition and mortality rates.
Selective rapid eye movement sleep deprivation impairs the maintenance of long‐term potentiation in the rat hippocampus
Authors: Ishikawa Akinori , Kanayama Yasuyo , Matsumura Hideki , Tsuchimochi Hirotsugu , Ishida Yoshiyuki , Nakamura Shoji
Published: July 2006

Rapid eye movement (REM) sleep deprivation (RSD) is known to impair learning and memory. Previous studies have demonstrated that RSD induces an impairment of hippocampal long‐term potentiation (LTP). In most of these studies, RSD was set up prior to LTP induction. In this work, we focused on RSD after LTP induction. We investigated the effect of RSD for 24–48 h after induction of LTP in the dentate gyrus on LTP maintenance and whether a REM rebound after 48 h RSD affected LTP. RSD rats were deprived of REM sleep by stroking their backs using a brush, whereas control rats were allowed to sleep freely. Another control group of rats was awoken during non‐REM sleep (NRS) under the same conditions (NRS group). REM‐deprived rats displayed a faster decay of population spike amplitudes compared with the control and NRS groups over a 24‐h recording time. After 48 h RSD, there was no difference in the population spike amplitudes before or after 4 h of release from RSD. These results suggest that REM sleep after LTP induction in the dentate gyrus plays an essential role in LTP maintenance, whereas a REM rebound does not restore the RSD‐induced impairment of LTP.
Dynamics of narrow‐band EEG phase effects in the passive auditory oddball task
Authors: Barry Robert J. , Rushby Jacqueline A. , Smith Janette L. , Clarke Adam R. , Croft Rodney J.
Published: July 2006

Evidence suggests that the component frequencies of the electroencephalogram (EEG) are dynamically adjusted to provide particular brain states at stimulus occurrence, and that these facilitate cortical processing of the stimulus. We examined relationships between stimulus intensity, the phase of narrow‐band EEG activity at stimulus onset, and the resultant event‐related potentials (ERPs) in a passive auditory oddball task, using a novel conceptualization of orthogonal phase effects (cortical negativity vs. positivity, negative driving vs. positive driving, waxing vs. waning). EEG responses to the standard stimuli (50 vs. 80 dB, varied between subjects) were analysed. Prestimulus narrow‐band EEG activity (in 1‐Hz bands from 1 to 13 Hz) at Cz was assessed for each trial by digital filtering. For each frequency, the cycle at stimulus onset was used to sort trials into four phases, for which ERPs were derived from both the filtered and unfiltered EEG activity at Fz, Cz and Pz. Preferred brain states at various frequencies were indicated by 16–34% differential occurrence within the orthogonal phase dimensions explored. The preferred states were associated with smaller N1, N2 and N3, larger P2 and P3, shorter N1, P2, N2 and P3 latencies, and some intensity effects. These effects reflected the operation of three separate phase‐influenced mechanisms, involving anticipatory potentials and prestimulus/poststimulus amplitudes in various EEG frequencies. Results indicate that, even in paradigms with a slightly varying interstimulus interval, brain dynamics provide preferred brain states at the moment of stimulus presentation, which differentially affect the EEG correlates of stimulus processing.
Cholinergic modulation of response properties and orientation tuning of neurons in primary visual cortex of anaesthetized Marmoset monkeys
Authors: Zinke W. , Roberts M. J. , Guo K. , McDonald J. S. , Robertson R. , Thiele A.
Published: July 2006

Cortical processing is strongly influenced by the actions of neuromodulators such as acetylcholine (ACh). Early studies in anaesthetized cats argued that acetylcholine can cause a sharpening of orientation tuning functions and an improvement of the signal‐to‐noise ratio (SNR) of neuronal responses in primary visual cortex (V1). Recent in vitro studies have demonstrated that acetylcholine reduces the efficacy of feedback and intracortical connections via the activation of muscarinic receptors, and increases the efficacy of feed‐forward connections via the activation of nicotinic receptors. If orientation tuning is mediated or enhanced by intracortical connections, high levels of acetylcholine should diminish orientation tuning. Here we investigate the effects of acetylcholine on orientation tuning and neuronal responsiveness in anaesthetized marmoset monkeys. We found that acetylcholine caused a broadening of the orientation tuning in the majority of cells, while tuning functions became sharper in only a minority of cells. Moreover, acetylcholine generally facilitated neuronal responses, but neither improved signal‐to‐noise ratio, nor reduced trial‐to‐trial firing rate variance systematically. Acetylcholine did however, reduce variability of spike occurrences within spike trains. We discuss these findings in the context of dynamic control of feed‐forward and lateral/feedback connectivity by acetylcholine.
Expression of Drosophila BarH1‐H2 homeoproteins in developing dopaminergic cells and segmental nerve a (SNa) motoneurons
Authors: Garces Alain , Bogdanik Laurent , Thor Stefan , Carroll Patrick
Published: July 2006

Barh1/h2 genes encode two related homeobox transcription factors (B‐H1 and B‐H2) previously shown to play essential roles in the formation and specification of the distal leg segments and in retinal neurogenesis. Here we describe the restricted expression pattern of the B‐H1/‐H2 homeoprotein within the embryonic ventral nerve cord of Drosophila. We show that B‐H1/‐H2 are specifically expressed in a subset of dopaminergic neurons, namely the unpaired ventral midline dopaminergic neuron, and in a subpopulation of laterally projecting motoneurons, i.e. the five motoneurons forming the segmental nerve a (SNa) branch. Using the GAL4–UAS system we show that B‐H1/‐H2Gal4 in combination with a membrane‐targeted enhanced green fluorescent protein reporter line provides a powerful genetic tool reproducibly to label SNa motoneuron projections and terminals at the periphery, and their dendritic tree in the ventral nerve cord. Thus, the highly restricted expression pattern of the B‐H1/‐H2 homeoproteins and notably the related Gal4 driver represent powerful genetic tools to identify and study genes that control axon guidance, synaptogenesis or dendritic arborization within a small subpopulation of motoneurons identifiable from embryogenesis to late larval stages.
Substantia nigra pars compacta is critical to both the acquisition and expression of learned orienting of rats
Authors: El‐Amamy Heather , Holland Peter C.
Published: July 2006

Novel events produce characteristic orienting responses (ORs), which typically habituate rapidly with repeated stimulus presentation. However, they may re‐emerge if those stimuli become predictors of biologically significant events. This acquisition of conditioned ORs may reflect a broader range of enhancements in top‐down attentional processing of cues that predict important consequences. Previous research from this laboratory showed that a neural circuit that includes the amygdala central nucleus (CeA), substantia nigra pars compacta (SNc) and dorsolateral striatum (DLS) is essential for the learning and expression of one example of conditioned orienting, the rearing of rats to visual stimuli paired with food. Other studies showed that the CeA is critical to the acquisition of these conditioned ORs, but not their expression, and that normal DLS function is required for the expression of previously acquired conditioned ORs, but not for learning itself. The experiments reported here considered the roles of the SNc in conditioned orienting by examining the effects of transient inactivation of the SNc during the acquisition of new associations and during the expression of previous learning. SNc function was critical to both the acquisition and expression of conditioned ORs but not to the display of unconditioned ORs or the learning and expression of conditioned responses directed to the food source. Together with our previous findings, these results suggest that the SNc is trained by the CeA during learning and maintains acquired information so that it may modulate DLS sensory‐motor function at the time of action.