bluuebunny/crossref_metadata_2025 huggingface dataset:
The biogeography of Gunnera L.: vicariance and dispersal
Authors: Wanntorp Livia , Wanntorp Hans‐Erik
Published: October 2010

Aim The genus Gunnera is distributed in South America, Africa and the Australasian region, a few species reaching Hawaii and southern Mexico in the North. A cladogram was used to (1) discuss the biogeography of Gunnera and (2) subsequently compare this biogeographical pattern with the geological history of continents and the patterns reported for other Southern Hemisphere organisms.

Location Africa, northern South America, southern South America, Tasmania, New Zealand, New Guinea/Malaya, Hawaii, North America, Antarctica.

Methods A phylogenetic analysis of twenty‐six species of Gunnera combining morphological characters and new as well as published sequences of the ITS region, rbcL and the rps16 intron, was used to interpret the biogeographical patterns in Gunnera. Vicariance was applied in the first place and dispersal was only assumed as a second best explanation.

Results The Uruguayan/Brazilian Gunnera herteri Osten (subgenus Ostenigunnera Mattfeld) is sister to the rest of the genus, followed sequentially upwards by the African G. perpensa L. (subgenus Gunnera), in turn sister to all other, American and Australasian, species. These are divided into two clades, one containing American/Hawaiian species, the other containing all Australasian species. Within the Australasian clade, G. macrophylla Blume (subgenus Pseudogunnera Schindler), occurring in New Guinea and Malaya, is sister to a clade including the species from New Zealand and Tasmania (subgenus Milligania Schindler). The southern South American subgenus Misandra Schindler is sister to a clade containing the remaining American, as well as the Hawaiian species (subgenus Panke Schindler). Within subgenus Panke, G. mexicana Brandegee, the only North American species in the genus, is sister to a clade wherein the Hawaiian species are basal to all south and central American taxa.

Main conclusions According to the cladogram, South America appears in two places, suggesting an historical explanation for northern South America to be separate from southern South America. Following a well‐known biogeographical pattern of vicariance, Africa is the sister area to the combined southern South America/Australasian clade. Within the Australasian clade, New Zealand is more closely related to New Guinea/Malaya than to southern South America, a pattern found in other plant cladograms, contradictory to some of the patterns supported by animal clades and by the geological hypothesis, respectively. The position of the Tasmanian G. cordifolia, nested within the New Zealand clade indicates dispersal of this species to Tasmania. The position of G. mexicana, the only North American species, as sister to the remaining species of subgenus Panke together with the subsequent sister relation between Hawaii and southern South America, may reflect a North American origin of Panke and a recolonization of South America from the north. This is in agreement with the early North American fossil record of Gunnera and the apparent young age of the South American clade.
Reconstructing the spread of invasive plants: taking into account biases associated with herbarium specimens
Authors: Delisle Fanny , Lavoie Claude , Jean Martin , Lachance Daniel
Published: October 2010

AimTo reconstruct the spread of invasive wetland species using herbarium specimens and to develop a method that accounts for the biases associated with this type of historical record.

LocationSouthern Québec.

MethodsThe temporal and spatial distribution of herbarium specimens of vascular plants was examined. Six invasive species that are mainly found in wetlands were compared with five native, non‐expanding hydrophytes. The cumulative number of locations was plotted against time to construct invasion curves. For native species, this ‘invasion curve’ indicates the spatiotemporal distribution of the sampling for herbarium specimens of wetland plants. It also represents the history of the state of knowledge of the distribution of native species. Deviation from the native species invasion curve can be used to describe the spread of invasive species. For every year on record, the cumulative number of locations of each exotic species was divided by the cumulative number of locations of all native species, and the proportions obtained were plotted against time. Periods of invasiveness were then delineated.

ResultsDuring the twentieth century, two periods of intensive herbarium specimen collection in Québec can be clearly distinguished, i.e. from 1930 to 1940 and from 1950 to 1985. Several periods of invasiveness were delineated forButomus umbellatusL. (1922–35),Hydrocharis morsus‐ranaeL. (1957–96),Lycopus europaeusL. (1963–2000),Lythrum salicariaL. (1890–1905, 1923–46),Phragmites australis(Cav.) Trin. ex Steudel (1963–84) andRorippa amphibia(L.) Bess. (1929–34, 1943–52, 1971–79).

Main conclusionsAccounting for sampling biases associated with herbarium specimens is important in order to objectively delineate periods of invasiveness for exotic species. The spread of wetland vascular plant species can be reconstructed using herbarium specimens, even when the phenomenon is rapid, but the reconstruction is certainly more accurate when the invasion occurred during an active sampling period. The highly variable sampling effort for herbarium specimens in Québec and in other regions strongly cautions against using herbarium data without correction procedures.
Integrating individual habitat choices and regional distribution of a biodiversity indicator and top predator
Authors: Sergio Fabrizio , Marchesi Luigi , Pedrini Paolo
Published: October 2010

Aim  Habitat selection studies have mainly focused on behavioural choices of individuals or on the habitat‐related regional distribution of a population, with little integration of the two approaches. This is despite the fact that traditional biogeography theory sees the geographical distribution of a species as the collective outcome of the adaptive habitat choices of individuals. Here, we integrate individual habitat choices with regional distribution through a bottom‐up Geographical Information System (GIS)‐based approach, by using a 9‐year data set on a large avian predator, the eagle owl (Bubo bubo L.). We further examine the potential population level and biodiversity consequences of this approach.

Location  The study was conducted in the Trento Region (central‐eastern Italian Alps) and in six other areas of the nearby Lombardia Region in the central Alps.

Methods  We used stepwise logistic regression to build a habitat suitability model discriminating between eagle owl territories and an equal number of random locations. The model was applied to the whole Trento region by means of a GIS so as to predict suitable habitat patches. The predicted regional distribution (presence–absence in 10‐km grid quadrats) was then compared with the observed one. Furthermore, we compared estimates of biodiversity in quadrats with and without eagle owls, so as to test whether the presence of this top predator may signal macro‐areas of high biodiversity.

Results  The logistic habitat suitability model showed that, compared with a random distribution, eagle owls selected low‐elevation breeding sites with high availability of prey‐rich habitats in their surroundings. Breeding performance increased with the availability of prey‐rich habitats, confirming the adaptiveness of the detected habitat choices. We applied the habitat suitability model to the 6200 km2 study region by means of a GIS and found a close fit between the observed and predicted regional distribution. Furthermore, population abundance was positively related to the availability of habitat defined as suitable by the above analyses. Finally, high biodiversity levels were associated with owl presence and with the amount of suitable owl habitat, demonstrating that modelling habitat suitability of a properly chosen indicator species may provide key conservation information at the wider ecosystem level.

Main conclusions  Our bottom‐up modelling approach may increase the conservation‐value of habitat selection models, by (1) predicting local and regional distribution, (2) estimating regional population size, (3) stimulating further hypothesis testing, (4) forecasting the population effects of future habitat loss and degradation and (5) aiding in the identification and prioritization of high‐biodiversity areas.
Relationships between land snail assemblage patterns and soil properties in temperate‐humid forest ecosystems
Authors: Martin Konrad , Sommer Michael
Published: October 2010

Aim The objectives were to (1) analyse the combined effects of soil pH, Ca content and soil moisture on total density and species richness of land snails in forest ecosystems, (2) explore relationships between the quantitative composition of snail assemblages and habitat characteristics, (3) investigate the relationships between soil pH and density of some of the most frequent species, and (4) compare the data with those from studies conducted in other temperate‐humid regions of Europe.

Location Study sites were selected from 15 landscape types including different lithologies within the area of Baden‐Württemberg (35,000 km2), SW Germany.

Methods Snails were recorded quantitatively from 83 study sites, with four plots representing a total of 0.25 m2per site. Topsoil samples from each site were analysed for pH, exchangeable Ca, and Ca content of carbonates. Three categories of soil moisture (dry, intermediate and wet) were established and defined according to the (climatic) water balance. Numbers of individuals and species were brought in relation to soil moisture and soil pH. Cluster analyses were conducted to identify groups of quantitatively similar snail species assemblages.

Results Topsoil pH (2.7–7.5) and soil Ca contents were closely correlated. On dry soils, total snail density and species richness are generally low and do not change with pH, but clearly increase with increasing pH on intermediate moisture soils and on wet soils. On the latter, numbers of individuals and species are generally much higher compared with intermediate moisture sites at the same value of soil pH. Changes of density in relation to soil pH vary between species. Depending on the species, density increases only in the lower or only in the higher range of pH, is not related to pH, or decreases with increasing pH. Furthermore, these patterns vary within the same species depending on the region. This became evident from comparisons with other studies, particularly between sites in SW Germany and southern Scandinavia. From cluster analyses, subgroups of snail assemblages of high quantitative similarity were identified. Group formation is explained by soil pH to some extent, and one subgroup showed a connection with coniferous woodland sites on acidic soils. No further environmental factors available from our data could explain the clustering of snail assemblages more detailed.

Main conclusions Soil moisture is the strongest determinant of snail density and species richness at undisturbed woodland sites, but effects of soil moisture and soil pH on these patterns are closely interrelated on intermediate moisture soils and wet soils. However, the quantitative species composition of the land snail assemblages is related to soil properties to a lower degree than snail density and species richness, and other habitat characteristics such as vegetation or litter quality, can be important for species dominance in addition.
Speciation centres and sustainable development
Authors: Salomon Marc
Published: October 2010

Biodiversity can be regarded as the result of the dynamic processes starting with speciation and ending with species extinction. Speciation urges populations of organisms within an already‐existing species to change as a consequence of ecological change. It can occur everywhere as the selective pressures causing it are randomly distributed (Dobzhansky et al., 1977, p. 4); hence, a need to promote a development policy that does not endanger these natural processes. This conservation concept addresses a global ecological policy and is different from the more classical concept of conservation based on the promotion of natural parks to preserve rare species and their direct habitats. The latter concept has the disadvantage to lead to the protection of limited surfaces, which cannot harbour most of speciation centres and leaves the rest of the world unprotected. Examples will illustrate the dangers faced by continental and insular speciation centres.
Diaphragmatic sulci and portal fissures
Authors: Macchi Veronica , Feltrin Giampietro , Parenti Anna , De Caro Raffaele
Published: October 2010

Diaphragmatic sulci in the superior surface of the liver were found in 40% of cases at autopsy. All sulci were located in the right lobe and in 47% they were multiple. In order to evaluate possible predisposing factors for these accessory sulci, their topography and characteristics were observed in unfixed livers; moreover, intravenous injections of radio‐opaque resins were performed in the portal and hepatic veins (HVs). After formalin fixation, the livers underwent CT and MR scans and a three‐dimensional (3D) elaboration of the images was performed. Radiological examination revealed a correspondence between the topography of the sulci and the course of the right and middle HVs and their main tributaries in 67%. The corrosion casts showed the location of the sulci at the level of the boundaries between the ramifications of the terminal branches of the portal triad, where the HVs are located, in 73%. These findings suggest that, rather than the action of ‘special’ or hypertrophied muscle bundles, the pressure exerted by the diaphragm as a whole may be responsible for the production of sulci at the level of weak zones, represented by the portal fissures, where the watershed superficial hepatic parenchyma, owing to the absence of all but the smallest vascular branches, exhibits a lower resistance to external pressure.
Retinol‐induced apoptosis in larval pancreas of Bufo bufo
Authors: Accordi F. , Chimenti C.
Published: October 2010

Tadpoles of Bufo bufo at the end of premetamorphosis were exposed to the action of retinol diluted in the rearing water at two concentrations: 20 and 40 µm, for 48 h. Assuming that retinol causes growth suppression by cell death induction, the TUNEL reaction for the detection of apoptotic cells was performed on paraffin sections of pancreas. The results showed that retinol induced a significant dose‐dependent increase of number of apoptotic cells with respect to controls, in which apoptosis was scarce. Electron microscopic observations of treated specimens showed that the effects of retinol mostly occurred on exocrine cells: condensed crescent‐shaped nuclear chromatin, dark cytoplasm with long projections; conversely, mitochondria and endoplasmic reticulum appeared unaffected.
The three‐dimensional architecture of the notochordal nucleus pulposus: novel observations on cell structures in the canine intervertebral disc
Authors: Hunter Christopher J. , Matyas John R. , Duncan Neil A.
Published: October 2010

Cells from the nucleus pulposus of young (< 2 years) and old (> 5 years) non‐chondrodystrophoid dogs were studied using routine histology, confocal laser scanning microscopy and transmission electron microscopy. The architecture of cell structures – from the tissue scale down to subcellular scale – was reported. Clusters of notochordal cells were observed in young nuclei pulposi, ranging from 10 to 426 cells each. These clusters resisted mechanical disruption and showed evidence of cell–cell signalling via gap junctions. Cells (30–40 µm in diameter) within the clusters had a physaliferous appearance, containing numerous large inclusions which ranged from 1 to 20 µm in diameter. The inclusions were surrounded by a dense actin cortex but were not contained by a lipid bilayer. The contents of the inclusions were determined not to be predominantly carbohydrate or neutral lipid as assessed by histochemical staining, but the exact composition of the contents remained uncertain. There were striking differences in the cell architecture of young vs. old nuclei pulposi, with a loss of both cell clusters and physaliferous cells during ageing. These observations demonstrate unique cell structures, which may influence our understanding of the differences between notochordal and chondrocytic cells in the nucleus pulposus. Such differences could have substantial impact upon how we think about development, degeneration and repair of the intervertebral disc.
Septation and separation within the outflow tract of the developing heart
Authors: Webb Sandra , Qayyum Sonia R. , Anderson Robert H. , Lamers Wouter H. , K. Richardson Michael
Published: October 2010

The developmental anatomy of the ventricular outlets and intrapericardial arterial trunks is a source of considerable confusion. First, major problems exist because of the multiple names and definitions used to describe this region of the heart as it develops. Second, there is no agreement on the boundaries of the described components, nor on the number of ridges or cushions to be found dividing the outflow tract, and the pattern of their fusion. Evidence is also lacking concerning the role of the fused cushions relative to that of the so‐called aortopulmonary septum in separating the intrapericardial components of the great arterial trunks. In this review, we discuss the existing problems, as we see them, in the context of developmental and postnatal morphology. We concentrate, in particular, on the changes in the nature of the wall of the outflow tract, which is initially myocardial throughout its length. Key features that, thus far, do not seem to have received appropriate attention are the origin, and mode of separation, of the intrapericardial portions of the arterial trunks, and the formation of the walls of the aortic and pulmonary valvar sinuses. Also as yet undetermined is the formation of the free‐standing muscular subpulmonary infundibulum, the mechanism of its separation from the aortic valvar sinuses, and its differentiation, if any, from the muscular ventricular outlet septum.
Vascular adaptations for heat conservation in the tail of Florida manatees (Trichechus manatus latirostris)
Authors: Rommel Sentiel A. , Caplan Heather
Published: October 2010

Although Florida manatees (Trichechus manatus latirostris) have relatively low basal metabolic rates for aquatic mammals of their size, they maintain normal mammalian core temperatures. We describe vascular structures in the manatee tail that permit countercurrent heat exchange (CCHE) to conserve thermal energy. Approximately 1000 arteries juxtaposed to 2000 veins are found at the cranial end of the caudal vascular bundle (CVB); these numbers decrease caudally, but the 1 : 2 ratio of arteries to veins persists. Arterial walls are relatively thin when compared to those previously described in vascular countercurrent heat exchangers in cetaceans. It is assumed that CCHE in the CVB helps manatees to maintain core temperatures. Activity in warm water, however, mandates a mechanism that prevents elevated core temperatures. The tail could transfer heat to the environment if arterial blood delivered to the skin were warmer than the surrounding water; unfortunately, CCHE prevents this heat transfer. We describe deep caudal veins that provide a collateral venous return from the tail. This return, which is physically outside the CVB, reduces the venous volume within the bundle and allows arterial expansion and increased arterial supply to the skin, and thus helps prevent elevated core temperatures.
Effects of sex hormones on the development of giant lysosomes in the proximal tubules of DBA/2Cr mouse kidney
Authors: Yabuki Akira , Suzuki Syusaku , Matsumoto Mitsuharu , Nishinakagawa Hayao
Published: October 2010

The DBA/2Cr mouse strain is characterized by giant lysosomes that are located in the proximal convoluted tubules of males and in the proximal straight tubules of females. In the present study, we used light microscopy and electron microscopy to investigate the effects of sex hormones on the development of these giant lysosomes. In the proximal convoluted tubules of males, giant lysosomes (large vacuolar structures observed under light microscopy) disappeared after orchiectomy but reappeared after testosterone treatment. No changes were observed after ovariectomy or estradiol treatment. In the proximal straight tubules of females, giant lysosomes (periodic acid Schiff‐positive giant granules observed under light microscopy) disappeared after ovariectomy but reappeared after estradiol treatment. After orchiectomy and testosterone treatment, the giant lysosomes did not appear. However, a number of small lysosomes (smaller than a nucleus), which were periodic acid Schiff‐positive, increased after orchiectomy and decreased after testosterone treatment. These findings suggest that lysosomes in DBA/2Cr mice are regulated by testosterone or estradiol as follows: (1) in the proximal convoluted tubules, the development of lysosomes is stimulated by testosterone but not by estradiol; (2) in the proximal straight tubules, development of lysosomes is stimulated by estradiol and inhibited by testosterone.
Differential expression of type XII collagen in developing chicken metatarsal tendons
Authors: Zhang Guiyun , Young Blanche B. , Birk David E.
Published: October 2010

Type XII collagen is a fibril‐associated collagen with multiple functional domains. The purpose of this work was to determine its role in regulating tendon matrix assembly. The temporal and spatial expression patterns of both collagen and mRNA were analysed in developing chicken metatarsal tendons using immunofluorescence microscopy, in situ hybridization and real‐time quantitative PCR. Temporally, type XII collagen was present during all stages of development (day 14‐hatch). However, spatially, type XII collagen expression shifted from the entire tendon at day 14, when the tendon is immature and fascicles are not well developed, to the interfacial matrix (endotendinium) associated with developing fascicles. This shift was obvious beginning at day 17, becoming prominent at day 19. Associated with this shift was a gradual decrease in type XII collagen reactivity in the tendon proper (non‐sheath). By hatching, the reactivity was sequestered almost exclusively to the sheaths with some reactivity remaining at the fibroblast–matrix interface within the fascicle. In situ hybridization indicated that fibroblasts in the tendon expressed type XII collagen mRNA homogeneously at day 14. However, by hatching, when the tendon matures, type XII collagen is restricted primarily to the sheath cells. Quantitative PCR analyses, of NC3 splice variants, demonstrated highest expression levels for the short splice variant mRNA at days 14–17, followed by a significant decrease at day 19 with levels remaining constant to adult. Long variant mRNA expression was highest at day 14 then decreased and was constant from day 17 to adult. These changing patterns may be related to the spatial shift in type XII collagen expression to the sheaths. Differential temporal and spatial expression patterns indicate that type XII collagen functions to integrate the developing tendon matrices and fascicles into a functional unit.
Effects of detailed information about dissection on intentions to bequeath bodies for use in teaching and research
Authors: Greene J. R. T.
Published: October 2010

Almost all UK medical schools teach anatomy using human bodies that have been bequeathed specifically for the purpose. Persons intending to make this most generous gift should be fully informed about how their body will be used. If detailed descriptions of dissection reduce the number of bequests, then this traditional and effective approach to anatomy teaching will have to change. To determine what effect detailed information has on intentions to bequeath, the Department of Anatomy at Bristol University sent all 139 people who asked for information, between July and December 2001, a description of dissection that included the statement ‘Anatomical examination requires that bodies be dissected (taken apart) so that the fine detail of internal structures can be seen. Organs, such as the heart, lungs and brain, are often removed from the body to allow for more detailed study.’ Views were sought by questionnaire (response rate 88%). Ninety‐nine per cent of respondents intended to bequeath their body and 88% would allow it to be used in research or teaching with the department to make the final decision. Thus the provision of detailed information about dissection should not reduce the number of bequests and this mechanism could, subject to law, make bodies available for research as well as for teaching.
Preservation of three‐dimensional capillary structure in frog muscle during aestivation
Authors: Hudson Nicholas J. , Franklin Craig E.
Published: October 2010

In mammals, prolonged immobilization of the limbs can result in a loss of capillary tortuosity, resulting in skeletal muscle haemorrhaging if rapid remobilization is permitted. In this study, we examined the effect of 4 months’ immobilization on semimembranosus capillary structure in the Green‐striped burrowing frog, Cyclorana alboguttata. C. alboguttata routinely aestivates as part of a physiological strategy to avoid desiccation in semi‐arid environments and, in this capacity, the hindlimbs of C. alboguttata are immobilized in a cocoon for months at a time. We found that 4 months’ aestivation had no effect on three‐dimensional capillary structure in the semimembranosus muscle and that capillary tortuosity is preserved in immobilized C. alboguttata. The preservation of capillary structure in the hindlimb muscles of C. alboguttata in part accounts for their remarkable ability to emerge with a fully competent locomotor system after prolonged immobilization.
The number of cells expressing dopamine D2 receptor mRNA in rat brain caudate putamen is higher in oestrus
Authors: Uršič Matjaž , Bavdek Srdan V. , Zabavnik Jelka
Published: October 2010

Dopamine D2 receptors (D2‐Rs) in the central nervous system are involved in the control of locomotion, cognition, emotion and neuroendocrine secretion. The intensity of cellular responses to specific stimuli is dependent on the concentration of dopamine or its agonist, and the availability, as well as the concentration, of all the other components of the signalling pathway in the cell, including the receptors. Many factors can influence the level of mRNA encoding the receptors. In order to study the changes in the level of expression of the D2‐R mRNA in the brain of female rats at different stages of the oestrous cycle, we used a quantitative in situ hybridization technique. Four groups of animals were analysed: rats in prooestrus (POE), oestrus (OE), dioestrus 1 (DOE1) and dioestrus 2 (DOE2). A 35S‐labelled riboprobe was transcribed in vitro from the 1.5‐kb D2‐R cDNA. The caudate putamen of the rats, which shows the highest level of expression of D2‐R mRNA in the brain, was examined. The number of silver grains per cell, representing hybridization of riboprobe, and the number of cells expressing the D2‐R mRNA, were counted with the computer‐assisted image analysis system Lucia‐M. Our results show that the expression of the D2‐R mRNA in the lateral striatum varies during the oestrous cycle, with the highest expression measured during DOE2. The number of cells expressing the D2‐R mRNA also changes during the different phases, with the highest number being detected in OE. This indicates that during OE more cells transcribe the D2‐R mRNA. The results suggest that the variations in the concentration of the D2‐R mRNA in the caudate putamen of the rat brain at different stages of the reproductive cycle are caused by the combination of variable expression of the mRNA per cell and different number of the cells that express the mRNA.
Structure of the pelvic and penile urethra – relationship with the ducts of the sex accessory glands of the Mongolian gerbil (Meriones unguiculatus)
Authors: Pinheiro P. F. F. , Almeida C. C. D. , Segatelli T. M. , Martinez M. , Padovani C. R. , Martinez F. E.
Published: October 2010

The urethra is the main place of entry for sexually transmitted pathogens. However, there is little literature on the morphology of the urogenital system, principally the urethra and ducts of the sex accessory glands. The Mongolian gerbil is an insectivorous, herbivorous and monogamous rodent with nocturnal habits; it has been used successfully as a laboratory animal since the 1960s. Therefore, the objective of the present paper was to describe the structure and ultrastructure of the urethra and its relations to the ducts of the accessory sex glands of the Mongolian gerbil (Meriones unguiculatus), contributing to the understanding of the reproductive biology of the rodent and aiming to provide data for future experimental studies. Conventional techniques of light and scanning electron microscopy were utilized. The urethra and ducts of the accessory sex glands are similar to those of the albino rat and the mouse. However, there is variation in drainage type among accessory sex glands for the inner urethra. The ducts of the seminal vesicle, the ductus deferens, drain their contents independently into the ampullary duct that opens in the urethra. The ducts of the prostate, coagulating and bulbourethral glands drain their contents independently into the urethra.
Detomidine‐Propofol Anesthesia for Abdominal Surgery in Horses
Authors: Matthews Nora S. , Hartsfield Sandee M. , Hague Brent , Carroll Gwen L. , Short Charles E.
Published: October 2010

Objective—To evaluate propofol for induction and maintenance of anesthesia, after detomidine premedication, in horses undergoing abdominal surgery for creation of an experimental intestinal adhesion model.

Study Design—Prospective study.

Animals—Twelve horses (424 ± 81 kg) from 1 to 20 years of age (5 females, 7 males).

Methods—Horses were premedicated with detomidine (0.015 mg/kg IV) 20 to 25 minutes before induction, and a propofol bolus (2 mg/kg IV) was administered for induction. Propofol infusion (0.2 mg/kg/min IV) was used to maintain anesthesia. The infusion rate was adjusted to maintain an acceptable anesthetic plane as determined by muscle relaxation, occular signs, response to surgery, and cardiopulmonary responses. Oxygen (15 L/min) was insufflated through an endotracheal tube as necessary to maintain the SpO2greater than 90%. Systolic (SAP), mean (MAP), and diastolic (DAP) arterial pressures, heart rate (HR), electrocardiogram (ECG), respiratory rate (RR), SpO2(via pulse oximetry), and nasal temperature were recorded at 15 minute intervals, before premedication and after induction of anesthesia. Arterial blood gas samples were collected at the same times. Objective data are reported as mean (±SD); subjective data are reported as medians (range).

Results—Propofol (2.0 mg/kg IV) induced anesthesia (mean bolus time, 85 sec) within 24 sec (±22 sec) after the bolus was completed. Induction was good in 10 horses; 2 horses showed signs of excitement and these two inductions were not smooth. Propofol infusion (0.18 mg/kg/min ± 0.04) was used to maintain anesthesia for 61 ± 19 minutes with the horses in dorsal recumbency. Mean SAP, DAP, and MAP increased significantly over time from 131 to 148, 89 to 101, and 105 to 121 mm Hg, respectively. Mean HR varied over time from 43 to 45 beats/min, whereas mean RR increased significantly over anesthesia time from 4 to 6 breaths/min. Mean arterial pH decreased from a baseline of 7.41 ± 0.07 to 7.30 ± 0.05 at 15 minutes of anesthesia, then increased towards baseline values. Mean Paco2values increased during anesthesia, ranging from 47 to 61 mm Hg whereas PaO2values decreased from baseline (97 ± 20 mm Hg), ranging from 42 to 57 mm Hg. Muscle relaxation was good and no horses moved during surgery: Recovery was good in 9 horses and acceptable in 3; mean recovery time was 67 ± 29 minutes with 2.4 ± 2.4 attempts necessary for the horses to stand.

Conclusions—Detomidine‐propofol anesthesia in horses in dorsal recumbency was associated with little cardiovascular depression, but hypoxemia and respiratory depression occurred and some excitement was seen on induction.

Clinical Relevance—Detomidine‐propofol anesthesia is not recommended for surgical procedures in horses if dorsal recumbency is necessary and supplemental oxygen is not available (eg, field anesthesia).
The Association of Propofol Usage With Postoperative Wound Infection Rate in Clean Wounds: A Retrospective Study
Authors: Heldmann Eileen , Brown Dorothy Cimino , Shofer Frances
Published: October 2010

Objective—To determine if the use of propofol influences the postoperative infection rate of clean surgical wounds in dogs and cats.

Study Design—Retrospective study.

Sample Population—863 dogs and cats undergoing clean surgical procedures.

Methods—Medical and anesthetic records of surgical cases used as part of a previously described epidemiologic study on postoperative wound infection rates were reviewed. The records of all animals with clean surgical wounds were reviewed to determine if propofol had been used for anesthetic induction or maintenance during the procedure. To determine the effect of propofol use on wound infection rate, data were analyzed using Fisher's exact test, followed by multiple logistic regression to adjust for various factors, including surgery time, time from clipping to surgery, antibiotic usage, coexisting distant infection, endocrine disease, and the use of immunosuppressive drugs in the perioperative period.

Results and Conclusions—Of 863 dogs and cats with clean surgical wounds, 46 received propofol as part of the anesthetic protocol. A total of 6 of 46 animals (13%) receiving propofol developed postoperative wound infections, compared with 33 of 817 animals (4%) not receiving propofol (P= .014; % difference = 9%; 95% CI = 0.5% to 24%). Adjusting for all other factors evaluated, animals receiving propofol were 3.8 times more likely to develop postoperative wound infections compared to animals not given propofol (95% CI = 1.5–9.9).

Clinical Implications—Propofol is a lipid‐based emulsion capable of supporting microbial growth. Administration of a potentially contaminated solution may contribute to surgical wound infection or other patient morbidity or mortality. Strict aseptic technique in the preparation of the solution and prompt disposal of unused drug are imperative to curtail the potential for extrinsic contamination.
Persistent Frenulum of the Epiglottis in Four Foals
Authors: Yarbrough Tom B. , Voss ED , Herrgesell Eric J. , Shaw Michelle
Published: October 2010

Objective— To report the clinical signs and management of 4 foals with persistent frenulum of the epiglottis.

Study Design— Case report.

Animals— Four newborn foals.

Methods— Foals were admitted with a complaint of oronasal reflux after nursing. Variable systemic signs of aspiration pneumonia were evident. Nasal endoscopy confirmed persistent dorsal displacement of the soft palate. Persistent frenulum of the epiglottis, confirmed by oral endoscopic examination, was transected.

Results— After surgery, all foals had the epiglottis positioned normally, dorsal to the soft palate. Clinical signs of oronasal reflux resolved by the second nursing attempt in 3 foals, whereas this was difficult to assess in one foal that was nursed intermittently because of the mares behavior. This foal died 2 days later. The other 3 foals have had normal epiglottic function for 2–4 years.

Conclusions— Persistent frenulum of the epiglottis should be considered in foals with oronasal reflux from birth. With appropriate medical and surgical management the prognosis for resolution should be good.
Free-fall in a uniform gravitational field in noncommutative quantum mechanics
Authors: Castello-Branco K. H. C. , Martins A. G.
Published: October 2010

We study the free-fall of a quantum particle in the context of noncommutative quantum mechanics (NCQM). Assuming noncommutativity of the canonical type between the coordinates of a two-dimensional configuration space, we consider a neutral particle trapped in a gravitational well and exactly solve the energy eigenvalue problem. By resorting to experimental data from the GRANIT experiment, in which the first energy levels of freely falling quantum ultracold neutrons were determined, we impose an upper-bound on the noncommutativity parameter. We also investigate the time of flight of a quantum particle moving in a uniform gravitational field in NCQM. This is related to the weak equivalence principle. As we consider stationary, energy eigenstates, i.e., delocalized states, the time of flight must be measured by a quantum clock, suitably coupled to the particle. By considering the clock as a small perturbation, we solve the (stationary) scattering problem associated and show that the time of flight is equal to the classical result, when the measurement is made far from the turning point. This result is interpreted as an extension of the equivalence principle to the realm of NCQM.
Charge exchange recombination detection of low-Z and medium-Z impurities in the extreme UV using a digital lock-in technique
Authors: Brooks N. H. , Burrell K. H. , Isler R. C. , Meyer O. , Pablant N. A.
Published: October 2010

More sensitive detection of charge exchange recombination lines from low-Z elements, and first-time detection from the medium-Z elements nickel and copper, has been achieved in DIII-D plasmas with a digital lock-in technique. That portion of the extreme UV spectrum varying synchronously in time with the square-wave modulation of a high energy, neutral heating beam is extracted by forming a scalar product of a correlation function with the data record of each pixel in the linear array detector. The usual, dense array of collisionally excited, metallic lines from the tokamak plasma is strongly suppressed, leaving only a sparse spectrum of lines dominated by charge exchange recombination transitions from fully stripped, low-Z elements. In plasmas with high metal content, charge exchange recombination lines from the Li-like ions of nickel and copper have been positively identified.
The influence of composition and natural aging on clustering during preaging in Al–Mg–Si alloys
Authors: Torsæter M. , Hasting H. S. , Lefebvre W. , Marioara C. D. , Walmsley J. C. , Andersen S. J. , Holmestad R.
Published: October 2010

This work provides a detailed atom probe tomography study of clustering in the Al–Mg–Si system. Focus is on separating and understanding the influence of natural aging, preaging, and alloy composition on the clustering behavior of solute atoms. Two dilute alloys with the same total solute content have been studied, one Mg-rich and one Si-rich. The detrimental effect of natural aging for these alloys is investigated by comparing directly preaged samples to samples stored at room temperature before the preaging treatment. Clusters were identified in the atom probe datasets by the maximum separation method employing heuristically determined input parameters. It was found that seven days of intermediate natural aging gave a five times lower number density of clusters as compared to direct preaging for both alloy types. The clusters were of comparable size but their compositions depended on heat treatment history. Preaging promoted the formation of clusters with an Mg:Si ratio close to 1 in both alloys, while natural aging produced clusters with Mg:Si ratios more similar to those of the alloys.
Benchmarking NMR indirect nuclear spin-spin coupling constants: SOPPA, SOPPA(CC2), and SOPPA(CCSD) versus CCSD
Authors: Kjær Hanna , Sauer Stephan P. A. , Kongsted Jacob
Published: October 2010

Accurate calculations of NMR indirect nuclear spin-spin coupling constants require especially optimized basis sets and correlated wave function methods such as CCSD or SOPPA(CCSD). Both methods scale as N6, where N is the number of orbitals, which prevents routine applications to molecules with more than 10–15 nonhydrogen atoms. We have therefore developed a modification of the SOPPA(CCSD) method in which the CCSD singles and doubles amplitudes are replaced by CC2 singles and doubles amplitudes. This new method, called SOPPA(CC2), scales only as N5, like the original SOPPA-method. The performance of the SOPPA(CC2) method for the calculation of indirect nuclear spin-spin coupling constants is compared to SOPPA and SOPPA(CCSD) employing a set of benchmark molecules. We also investigate the basis set dependence by employing three different basis sets optimized for spin-spin coupling constants, namely the HuzIV-su4, ccJ-pVTZ, and ccJ-pVQZ basis sets. The results of the corresponding CCSD calculations are used as a theoretical reference.
Effects of chamber pressure variation on the grid temperature in an inertial electrostatic confinement device
Authors: Murali S. Krupakar , Emmert G. A. , Santarius J. F. , Kulcinski G. L.
Published: October 2010

Inertial electrostatic confinement fusion devices are compact sources of neutrons, protons, electrons, and x rays. Such sources have many applications. Improving the efficiency of the device also increases the applications of this device. Hence a thorough understanding of the operation of this device is needed. In this paper, we study the effect of chamber pressure on the temperature of the cathode. Experimentally, the grid temperature decreases as the chamber pressure increases; numerical simulations suggest that this is caused by the reduction of the hot ion current to the cathode as the pressure increases for constant power supply current. Such an understanding further supports the conclusion that the asymmetric heating of the cathode can be decreased by homogenizing the ion flow around the cathode.
The geometrical-optics law of reflection for electromagnetic waves in magnetically confined plasmas: Specular reflection of rays at the last closed flux surface
Authors: Bizarro João P. S.
Published: October 2010

Within the geometrical-optics approximation, it is shown that the reflection of rays describing the propagation of electromagnetic waves in fusion-grade, magnetically confined plasmas and impinging on the last closed flux surface, or plasma surface, is necessarily specular or mirror-like. More precisely, the component of the wave vector tangential to that surface does not change, whereas the component normal to it reverses its sign while keeping its magnitude. The well-known law of reflection, stating that the angle of incidence equals that of reflection, is thus generalized to anisotropic media.
Fast magnetic reconnection in three-dimensional magnetohydrodynamics simulations
Authors: Pang Bijia , Pen Ue-Li , Vishniac Ethan T.
Published: October 2010

A constructive numerical example of fast magnetic reconnection in a three-dimensional periodic box is presented. Reconnection is initiated by a strong, localized perturbation to the field lines. The solution is intrinsically three-dimensional and its gross properties do not depend on the details of the simulations. ∼30% of the magnetic energy is released in an event which lasts about one Alfven time, but only after a delay during which the field lines evolve into a critical configuration. The physical picture of the process is presented. The reconnection regions are dynamical and mutually interacting. In the comoving frame of these regions, reconnection occurs through a x-like point, analogous to Petschek reconnection. The dynamics appear to be driven by global flows, not local processes.
Development of in-vessel components of the microfission chamber for ITER
Authors: Ishikawa M. , Kondoh T. , Ookawa K. , Fujita K. , Yamauchi M. , Hayakawa A. , Nishitani T. , Kusama Y.
Published: October 2010

Microfission chambers (MFCs) will measure the total neutron source strength in ITER. The MFCs will be installed behind blanket modules in the vacuum vessel (VV). Triaxial mineral insulated (MI) cables will carry signals from the MFCs. The joint connecting triaxial MI cables in the VV must be considered because the MFCs and the MI cables will be installed separately at different times. Vacuum tight triaxial connector of the MI cable has been designed and a prototype has been constructed. Performance tests indicate that the connector can be applied to the ITER environment. A small bending-radius test of the MI cable indicates no observed damage at a curvature radius of 100 mm.
Stress-dependent susceptibility of Galfenol and application to force sensing
Authors: Evans P. G. , Dapino M. J.
Published: October 2010

A sensing principle, operating regime, and composition range are identified for force sensing with Galfenol alloys. Magnetization measurements of Fe79.1Ga20.9 and Fe81.6Ga18.4 are performed under applied magnetic field at constant stress. Stress-dependent, linear regions with negligible hysteresis are observed in the Fe79.1Ga20.9 sample over a large range of fields and stresses, for which an analytic model for unbiased loops is formulated. Similar regions are observed in the Fe81.6Ga18.4 sample, with a more limited stress and field range. The small signal operating regime (small in field, not in stress) centered about zero magnetic field is particularly advantageous because in this regime there is no observable hysteresis, since the magnetization process occurs by domain rotation only. The measurements and model show that in this region the susceptibility of Fe79.1Ga20.9 is more sensitive to stress (owing to a significantly lower fourth-order anisotropy constant) with only a small reduction in the saturation magnetization and magnetostriction as compared to Fe81.6Ga18.4. For force sensing, these results suggest the use of Galfenol with an ideal Ga content in the range of 19–22 at. % in which a small, positive fourth-order anisotropy constant is obtained, though in this composition range the magnetostriction is sacrificed.
Correlation between excitation temperature and electron temperature with two groups of electron energy distributions
Authors: Park Hoyong , You S. J. , Choe Wonho
Published: October 2010

The relationship between the electron excitation temperature (Texc) determined by optical emission spectroscopy and the electron temperature (Te) using a rf-compensated Langmuir probe was investigated in argon capacitively coupled plasmas. In the experiment performed at the gas pressure range of 30 mTorr to 1 Torr and the rf power range of 5–37 W, the electron energy probability function (EEPF) obtained from the probe current versus voltage characteristic curve showed two energy groups of electrons. The measured EEPF demonstrated that the electron energy distribution changed from Druyvesteyn to single Maxwellian as the discharge current was increased and from bi-Maxwellian to Druyvesteyn as the pressure was increased. As a result, Texc showed a tendency identical to that of Te of the high energy part of electrons as pressure and rf power were varied. This suggests that electron temperature can be determined from the measured Texc through a calibration experiment by which the ratio between electron and excitation temperatures is measured.