bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sediment waves in a modern high‐energy glacilacustrine environment
Authors: GILBERT ROBERT , CROOKSHANKS SARAH 
Published: August 2008

AbstractA 4·7 km2 field of sediment waves occurs in front of the Slims River delta in Kluane Lake, the largest lake in the Yukon Territory. Slims River heads in the Kaskawulsh Glacier, part of the St Elias Ice Field and discharges up to 400 m3 s−1 of water with suspended sediment concentrations of up to 7 g l−1. The 19 km long sandur of Slims River was created in the past 400 years since Kaskawulsh Glacier advanced and dammed the lake and the sandur has advanced into Kluane Lake at an average rate of 48 m a−1. However, this rate is decreasing as flow is diverted from Slims River because of the retreat of the Kaskawulsh Glacier. The sandur and a road constructed on the delta remove coarse‐grained sediment, so the river delivers dominantly mud to the lake. Inflow during summer generates quasi‐continuous turbidity currents with velocities up to 0·6 m s−1. The front of the delta consists of a plane surface sloping lakeward at 0·0188 (1·08°). A field of sediment waves averaging 130 m in length and 2·3 m in amplitude has developed on this surface. Slopes on the waves vary from −0·067 (−3·83°, i.e. sloping in the opposite direction to the regional slope) to 0·135 (7·69°). The internal structure of the sediment waves, as documented by seismic profiling, shows that sedimentation on the stoss portion of the wave averages 2·7 times that on the lee portion. Rates of sediment accumulation in the wave field are about 0·3 m a−1, so these lacustrine waves have formed in a much shorter period of time (less than 200 years) and are advancing upslope towards the delta much more quickly (1 to 2 m a−1) than typical marine sediment waves. These waves formed on the flat surface of the lake floor, apparently in the absence of pre‐existing forms, and they are altered and destroyed as the wave field advances and the characteristics of the turbidity currents change.
Vertical gradational variability of fines deposited in a gravel framework
Authors: GIBSON STANFORD , ABRAHAM DAVID , HEATH RONALD , SCHOELLHAMER DAVID 
Published: August 2008

AbstractVertical gradational structures develop as sand infiltrates into static gravel beds. Understanding the vertical distribution of interstitial sand deposits will improve predictions of ecological suitability and hyporheic hydrodynamics. A series of flume experiments was performed to investigate fine infiltration processes. Four sand distributions were introduced into flows over gravel beds. After each experiment, bed cores were extracted and analysed in vertical layers to examine the gradational trends with depth. Vertical trends of fine content were highly sensitive to the relative grain‐size distributions of the gravel bed and the introduced sand. For experiments with d15gravel/d85sand ratios 15·4 and larger unimpeded static percolation was observed, where sand filled the voids relatively uniformly from the bottom of the gravel layer to the top. Experiments with ratios 10·6 and smaller bridged. Sand clogged a thin layer of gravel pores near the bed surface, precluding subsequent infiltration. Interstitial sand deposits fined with depth of penetration for all experiments which was the result of three distinct but overlapping processes. (i) Granular sorting: As particles fell through the substrate, smaller material preferentially passed through the voids deeper into the gravel. (ii) Bed‐load sorting: Size segregation occurs in the wake of the leading bed form as smaller particles saltate further and settle first. (iii) Hydraulic sorting: Smaller sand was transported preferentially as suspended load filling the deep voids of the furthest flume positions downstream. Finally, when the experiments that formed a bridge layer were replicated with higher bed shear stresses, less interstitial sand deposition was observed. Higher shear stresses transported coarse particles downstream more efficiently causing bridge layers to form earlier and allowing less time for suspended load to settle into the deeper substrate pores before the pathways were closed.
Bovine papillomaviruses: their role in the aetiology of cutaneous tumours of bovids and equids
Authors: Nasir Lubna , Campo M Saveria 
Published: August 2008

AbstractBovine papillomavirus (BPV) is perhaps the most extensively studied animal papillomavirus. In cattle BPVs induce benign tumours of cutaneous or mucosal epithelia, called papillomas or warts. Cattle papillomas are benign tumours and generally regress without eliciting any serious clinical problems in the host, but occasionally persist and provide the focus for malignant transformation to squamous cell carcinoma, as in the case of cancer of the urinary bladder and cancer of the upper alimentary canal. BPV is the only papillomavirus that jumps species: the virus also infects equids, and gives rise to fibroblastic tumours called sarcoids. Sarcoids very rarely regress, more often they persist and can be locally aggressive. These tumours are the most common dermatological tumour of equids worldwide.The purpose of this review is to discuss the biology of BPV, the biology of bovine tumours and equine sarcoids, and present the current understanding of BPV in tumour pathogenesis in its natural host, cattle, and in its heterologous host, equids. Finally, the use of anti‐BPV vaccines as a therapy for equine sarcoids will be discussed. Only limited information on the clinical or pathological aspects of either bovine or equine tumours will be provided as this subject has been extensively addressed previously.
The efficacy of commercially available veterinary diets recommended for dogs with atopic dermatitis
Authors: Glos Katharina , Linek Monika , Loewenstein Christine , Mayer Ursula , Mueller Ralf S. 
Published: August 2008

AbstractThe classical treatments for dogs with atopic dermatitis have traditionally been oral antipruritic drugs, allergen‐specific immunotherapy and topical therapy. Fifty dogs with atopic dermatitis were included in this multicentred, double‐blinded, randomized study to compare clinical response to an 8‐week period of feeding one of three commercial veterinary foods marketed for dogs with atopic dermatitis (diets A–C) or a widely distributed supermarket food (diet D). Atopic dermatitis was diagnosed using Willemse's criteria and through the exclusion of differential diagnoses. Fourteen dogs were assigned to diet A and 12 dogs each to diet B, C or D. Flea and tick control using a monthly fipronil spot‐on product was administered for a minimum of 4 weeks prior to inclusion in the study and during the study period. Evaluations were made monthly. These included lesion scores, using an established scoring system (canine atopic dermatitis extent and severity index, CADESI‐03) and owner evaluation of pruritus level using a visual analogue scale. After 8 weeks on the new diets, there was a significant improvement in CADESI and pruritus scores with diet B (Wilcoxon test,P = 0.043 and pairedt‐test,P = 0.012, respectively), in pruritus scores with diet A (pairedt‐test,P = 0.019) and in CADESI scores with diet D (Wilcoxon test,P = 0.037). No significant changes were detected with diet C. Based on the results of this study, in addition to the conventional therapies, changing the diet of dogs with atopic dermatitis may be a useful adjunctive therapeutic measure.
Cutaneous pythiosis in a nontravelled California horse
Authors: White Stephen D. , Ghoddusi Majid , Grooters Amy M. , Jones Kathryn 
Published: August 2008

AbstractAn 18‐year‐old Arabian mare was examined with a large mass on the left hind pastern and fetlock. The mare was located in the Central Valley of northern California, and had never been out of the state. Routine histopathological processing and examination of biopsy samples from the mass showed several hyphal organisms that were delineated with a silver stain. Using immunohistochemistry the organism was diagnosed as Pythium insidiosum. The owner declined debulking surgery, and despite treatment with an immunotherapeutic vaccine, the horse's condition deteriorated leading to euthanasia.
Microbiological and histopathological features of canine acral lick dermatitis
Authors: Shumaker A.K. , Angus J.C. , Coyner K.S. , Loeffler D.G. , Rankin S.C. , Lewis T.P. 
Published: August 2008

AbstractThe purpose of this study was to investigate microbiological and histopathological features of canine acral lick dermatitis (ALD). Microbial characteristics of ALD are poorly described in current literature. If infection is recognized, antimicrobial selection is usually empirical, based on appearance, cytology or surface culture, rather than deep tissue culture. It was hypothesized that cultures obtained from deep tissue would yield different results than predicted by surface culture and cytology, and that isolates from ALD have unpredictable susceptibility patterns showing resistance to antibiotics routinely administered for canine pyoderma. Biopsies were obtained from 31 lesions and submitted for aerobic, anaerobic and fungal culture, and histopathological evaluation. Surface aerobic culture and susceptibility and cytology were obtained for comparison in 22 dogs. Skin scrapings and dermatophyte culture were performed. Bacteria were isolated in 30 of 31 cases.Staphylococcus intermediuswas isolated in 58% of deep cultures. Twenty per cent of deep isolates were methicillin‐resistantStaphylococcusspecies. Forty‐eight per cent of cases yielded organisms defined as multidrug resistant on deep culture. Only 57% and 55% of bacteria isolated from tissue culture were sensitive to amoxicillin‐clavulanic acid and cefazolin, respectively. Cytology and superficial cultures did not correlate well with deep cultures. Surface culture predicted deep tissue isolates in eight of 22 cases. Microsporum gypseum was isolated from one dog. Histopathological features included acanthosis, follicular elongation, lymphoplasmacytic dermal inflammation, folliculitis, furunculosis, perihidradenitis, hidradenitis and vertical streaking fibrosis. Lesions associated with ALD warrant tissue bacterial cultures as the majority of cases yielded positive growth of bacteria differing from superficial culture and often resistant to empirical drugs.
PRECLINICAL STUDY: Acute and chronic cannabinoid treatment differentially affects recognition memory and social behavior in pubertal and adult rats
Authors: Schneider Miriam , Schömig Edgar , Leweke F. Markus 
Published: August 2008

ABSTRACTAlthough cannabis belongs to the most widely used drugs among adolescents, little is known about its acute and lasting neurobehavioral effects during critical developmental periods. In the present study we investigated acute and long‐term behavioral effects of the cannabinoid agonist WIN 55,212‐2 (WIN) in pubertal and adult rats. Chronic WIN (1.2 mg/kg)/vehicle treatment was extended over 25 days throughout puberty, from postnatal day (pd) 40 to pd 65, or for a similar time period in adult rats (> pd 80). All animals were tested at three time points for object/social recognition memory, social interaction and spontaneous social behavior. First, acute cannabinoid effects were investigated directly after the first injection. Additionally, behavioral performance was retested 24 hours and 15 days after cessation of WIN treatment. Chronic pubertal WIN treatment induced persistent object/social recognition deficits, indicating a general impairment in short‐term information processing. Lasting disturbances in social behavior, social play and self‐grooming were also found. Furthermore, behavioral deficits seen after acute WIN administration were more pronounced in pubertal than in adult rats. These results confirm our recent findings that chronic pubertal cannabinoid treatment leads to lasting behavioral alterations in adulthood, and they show that acute cannabinoid administration induces more severe behavioral deficits in pubertal rats than in mature animals. We therefore conclude that an immature brain is more susceptible to the acute and chronic effects of exogenous cannabinoids than an adult organism, which might be explained by an overactive endocannabinoid system and concomittant maturational disturbances in further neurotransmitter systems during pubertal development.
REVIEW: The systems view in addiction research
Authors: Gebicke‐Haerter Peter J. , Tretter Felix 
Published: August 2008

ABSTRACTThe wealth of information accessible on the molecular level after completion of sequencing of the human and other genomes and in conjunction with new high‐throughput technologies like microarrays has paved the way for research on whole systems rather than on single components. Here we describe exemplarily the construction of a rather complex molecular network involved in alcohol addiction by using information from DNA‐microarray studies in alcohol‐dependent animals. In this network, haemoglobin downregulation in different parts of the brain reward system plays a central role in affecting synaptic plasticity, circadian rhythmicity and opioid receptors. Furthermore, we discuss the dynamic aspect of biological systems with respect to repeated and intermittent drug intake. This aspect can best be captured by the allostatic model on the molecular level. Using a molecular oscillator model where levels of oscillations are changed by repetitive drug administration, changes in set point adjustment are described that underlay allostatic shifts in drug reinforcement processes.
Hemiclonal analysis reveals significant genetic, environmental and genotype × environment effects on sperm size in Drosophila melanogaster
Authors: MORROW E. H. , LEIJON A. , MEERUPATI A. 
Published: August 2008

AbstractSpermatozoa are the most diverse of all animal cells. Variation in size alone is enormous and yet there are still no clear evolutionary explanations that can account for such diversity. The basic genetics of sperm form is also poorly understood, although sperm size is known to have a strong genetic component. Here, using hemiclonal analysis of Drosophila melanogaster, we demonstrate that there is not only a significant additive genetic component contributing to phenotypic variation in sperm length but also a significant environmental effect. Furthermore, the plasticity of sperm size has a significant genetic component to it (a genotype × environment interaction). A genotype × environment interaction could contribute to the maintenance of the substantial genetic variation in this trait and thereby explain the persistent inter‐male differences in sperm size seen in numerous taxa. We suggest that the low conditional dependence and high heritability but low evolvability (the coefficient of additive genetic variation) of sperm length is more consistent with a history of stabilizing selection rather than either sexual selection or strong directional selection.
Selection for cuticular melanism reveals immune function and life‐history trade‐offs inSpodoptera littoralis
Authors: COTTER S. C. , MYATT J. P. , BENSKIN C. M. H. , WILSON K. 
Published: August 2008

AbstractSeveral insect species show an increase in cuticular melanism in response to high densities. In some species, there is evidence that this melanism is correlated with an up‐regulation of certain immune system components, particularly phenoloxidase (PO) activity, and with the down‐regulation of lysozyme activity, suggesting a trade‐off between the two traits. As melanism has a genetic component, we selected both melanic and nonmelanic lines of the phase‐polyphenic lepidopteran,Spodoptera littoralis, in order to test for a causative genetic link between melanism, PO activity and lysozyme activity, and to establish if there are any life‐history costs associated with the melanic response. We found that, in fact, melanic lines had lower PO activity and higher lysozyme activity than nonmelanic lines, confirming a genetic trade‐off between the two immune responses, but also indicating a genetic trade‐off between melanism and PO activity. In addition, we found that lines with high PO activity had slower development rates suggesting that investment in PO, rather than in melanism, is costly.
Establishing a perimeter position: speciation around the Indian Ocean Basin
Authors: VOELKER G. , OUTLAW R. K. 
Published: August 2008

AbstractHistorical biological interactions among peripheral landmasses on the periphery of the Indian Ocean Basin (IOB) are generally poorly understood. While interactions based on early Gondwanan vicariance have been used to explain present day lineage distributions, several recent studies have instead inferred dispersal across the IOB. This inference is often advanced because lineages under study have species inhabiting IOB islands. Here we examine the roles of continental vicariance vs. trans‐IOB dispersal in the distribution of an avian genus found around the perimeter of the IOB. A molecular phylogeny does reveal evidence of a relationship that would require the inference of trans‐IOB dispersal between eastern Africa and Sri Lanka. However, molecular clock data, ancestral area analyses and paleoclimatic reconstructions suggest that vicariance related to tropical forest expansion and retraction is more likely to have facilitated African–Asian interchange, with an initial colonization of Africa from Asia quickly followed by a recolonization of Asia. Subsequent dispersal from Asia to Sri Lanka and islands east of the Sunda Shelf are inferred; these latter islands were colonized in a stepping‐stone fashion that culminated in colonization of the Sunda Shelf, and a recolonization of mainland Asia. We propose that circum‐IOB distributions, which post‐date early Gondwanan breakup, are most likely the result of continent‐based vicariant events, particularly those events related to large‐scale habitat alterations, and not trans‐IOB dispersals.
Body size evolution in Mesozoic birds: little evidence for Cope’s rule
Authors: BUTLER R. J. , GOSWAMI A. 
Published: August 2008

AbstractCope’s rule, the tendency towards evolutionary increases in body size, is a long‐standing macroevolutionary generalization that has the potential to provide insights into directionality in evolution; however, both the definition and identification of Cope’s rule are controversial and problematic. A recent study [J. Evol. Biol. 21 (2008) 618] examined body size evolution in Mesozoic birds, and claimed to have identified evidence of Cope’s rule occurring as a result of among‐lineage species sorting. We here reassess the results of this study, and additionally carry out novel analyses testing for within‐lineage patterns in body size evolution in Mesozoic birds. We demonstrate that the nonphylogenetic methods used by this previous study cannot distinguish between among‐ and within‐lineage processes, and that statistical support for their results and conclusions is extremely weak. Our ancestor–descendant within‐lineage analyses explicitly incorporate recent phylogenetic hypotheses and find little compelling evidence for Cope’s rule. Cope’s rule is not supported in Mesozoic birds by the available data, and body size evolution currently provides no insights into avian survivorship through the Cretaceous–Paleogene mass extinction.
Mutants with aberrant numbers of gametic cells shed new light on old questions
Authors: Moll C. , Nielsen N. , Groß‐Hardt R. 
Published: August 2008

AbstractIn contrast to animals, plant gametes form in distinct haploid generations, termed gametophytes. The female gametophyte of Arabidopsis consists of two gametic cells, the egg and central cell, which are flanked by accessory cells. The gametic cells differ with respect to morphology, molecular attributes and, importantly, their fate: whereas the egg cell, upon fertilisation, gives rise to the embryo, the central cell forms the endosperm. To ensure correct endosperm formation, not only the egg cell but also the central cell has to fuse with a sperm cell. The respective sperm cell pair is delivered by a single pollen tube. In some plant species, the two male gametes appear to express a different bias towards the female gametes. Such a preference consequently determines their respective contribution to either embryo or endosperm development. In Arabidopsis and many other species the sperm cells are indistinguishable and it has been discussed whether they possess an inherent preference for either of the female gametes. The recent isolation of mutants that form an aberrant number of either male or female gametes stimulates discussion, albeit with different results. Furthermore, some data indicate that the central cell is competent to initiate endosperm formation without a paternal contribution. These data support the theory that the endosperm is of gametophytic rather than sporophytic origin.
How patients and nurses experience the acute care psychiatric environment
Authors: Shattell Mona M. , Andes Melanie , Thomas Sandra P. 
Published: August 2008

How patients and nurses experience the acute care psychiatric environment The concept of the therapeutic milieu was developed when patients’ hospitalizations were long, medications were few, and one‐to‐one nurse–patient interactions were the norm. However, it is not clear how the notion of ‘therapeutic milieu’ is experienced in American acute psychiatric environments today. This phenomenological study explored the experience of patients and nurses in an acute care psychiatric unit in the USA, by asking them, ‘What stands out to you about this psychiatric hospital environment?’ Three figural themes emerged, contextualized by time, which was a source of stress to both groups: for patients there was boredom, and for nurses, pressure and chaos. Although they shared some themes, nurses and patients experienced them differently. For instance, nurses felt caged‐in by the Plexiglas‐enclosed nursing station, and patients felt caged‐in by the locked doors of the unit. The findings from this US study do not support the existence of the therapeutic milieu as described in the literature. Furthermore, although the nurse–patient relationship was yearned for by nurses, it was nearly absent from patients’ descriptions. The caring experienced by patients was mainly derived from interactions with other patients.
Negotiating clinical knowledge: a field study of psychiatric nurses’ everyday communication
Authors: Buus Niels 
Published: August 2008

Negotiating clinical knowledge: a field study of psychiatric nurses’ everyday communication Nursing practices at psychiatric hospitals have changed significantly over the last decades. In this paper, everyday nursing practices were interpreted in light of these institutional changes. The objective was to examine how mental health nurses’ production of clinical knowledge was influenced by the particular social relations on hospital wards. Empirical data stemming from an extended fieldwork at two Danish psychiatric hospital wards were interpreted using interactionistic theory and the metaphor: ‘the game of clinical knowledge’. The results indicated that the nurses’ production of clinical knowledge was highly dependent on the individual nurses’ practical ability to participate in the game. Furthermore, the nurses colluded in their mutual communication to enable the collective display and sense of knowing that protected them against explicit signs of uncertainty about the clinic. The game of clinical knowledge influenced processes of clinical decision‐making among the nurses as the game added to a distorted widening of a ‘fictional distance’ between patients and the representations produced by the nurses.