bluuebunny/crossref_metadata_2025 huggingface dataset:
Impacts of climate, management and nitrogen deposition on the dynamics of lowland heathland
Authors: Britton Andrea J. , Pakeman Robin J. , Carey Pete D. , Marrs Rob H.
Published: February 2007

Abstract.The design of a cell‐based spatial simulation model of heathland vegetation dynamics including the impacts of rainfall, nitrogen deposition and management is described. The model includes aspects of life history, colonization and seed dispersal forCalluna vulgarisandDeschampsia flexuosa, a common heathland grass. The interactive effects of rainfall, nitrogen deposition and management by cutting or rotovating on vegetation dynamics, and particularly relative cover ofCallunaandDeschampsiaare investigated. Management by cutting or rotovating resulted in more stable vegetation dynamics, with pureCallunastands being persistent in the longer term andDeschampsiaexpanding more slowly when management was imposed. Cutting and rotovating management interacted differently with rainfall and nitrogen deposition. A smaller management interval was required to maintain highCallunacover by cutting when rainfall was low. More frequent cutting was also required under conditions of high nitrogen deposition. This effect was greatest in simulations with moderate to high rainfall. The outcome of management by rotovating was little affected by rainfall or nitrogen deposition. It is concluded that heathlands that experience varying climates may show different responses to nitrogen deposition and management. This variation should be taken into account when defining critical loads or designing management prescriptions.
GIS‐analysis of tree‐line elevation in the Swiss Alps suggests no exposure effect
Authors: Paulsen Jens , Körner Christian
Published: February 2007

Abstract. Counter intuition, an analysis of tree‐line position across the Swiss Alps based on a geographical information system (GIS) with a spatial resolution of 100 m (2.5 million points) revealed no difference in climatic tree‐line altitude with slope exposure. Through step wise discrimination procedures our analysis accounts for anthropogenic tree‐line depression. Any land cover bias affects the frequency of GIS‐points corresponding to tree‐line forests rather than the mean elevation of such points, captured by our analysis. We explain this phenomenon (1) by the absence of significant drought effects in the Alps (no disadvantages for southwest slopes), (2) by the fact that tree tops, unlike low stature vegetation, do not profit from greater radiation warming on south slopes during the growing season but are thermally coupled to free air circulation, and (3) by preliminary data for root zone temperatures during the growing season, which do not differ between south and north slopes, as long as the soil is screened by a closed forest canopy. The overall difference in season length and snow cover, often seen between south and north slopes, does not seem to affect tree‐line position but explains greater natural forest fragmentation on north slopes. It is this greater fragmentation and patchiness (avalanche tracks, snow beds etc.) which seem to have nourished the idea of a generally lower limit of tree growth and tree lines at northern slopes. These results are in line with a recently developed theory, which suggests that tree‐line elevations in humid climates correspond to similar isotherms, irrespective of latitude and thus, season length.
Effects of seed dispersal on Juniperus communis recruitment on a Mediterranean mountain
Authors: García Daniel
Published: February 2007

Abstract. The recruitment of the relict shrub Juniperus communis on a mountain in SE Spain was studied during the period 1994–1998. The main objective was to determine both the quantitative and qualitative effects of bird dispersal on seedling establishment. Seed removal by birds, seed rain, post‐dispersal seed predation, germination, and seedling emergence and survival were analysed in different microhabitats. Birds removed 53 ‐ 89% of the seeds produced by plants. Seed rain was spatially irregular as most seeds accumulated near stones used by birds as perches and below mother plants while a few seeds were dropped in wet meadows and open ground areas. Post‐dispersal seed predation by rodents affected < 10% of dispersed seeds but varied significantly among microhabitats. Only 3.6 ‐ 5.5% of dispersed seeds appeared viable, as many seeds had aborted or showed wasp damage. Seeds germinated in the second and third springs after sowing, reaching a germination percentage of 36%. Seedling emergence was concentrated in wet meadows. Seedling mortality was high (75–80%), but significantly lower in wet meadows, the only microhabitat where seedlings could escape from summer drought, the main mortality cause. Seed abortion, germination and seedling mortality proved to be the main regeneration constraints of J. communis on Mediterranean mountains. Birds exerted a strong demographic effect, although their qualitative effect was limited by abiotic factors which caused the pattern of seed rain to differ from the final pattern of recruitment between microhabitats.
Spatial analysis of structural and tree‐ring related parameters in a timberline forest in the Italian Alps
Authors: Carrer Marco , Urbinati Carlo
Published: February 2007

Abstract.We investigated the variability in spatial pattern of some structural, dendrochronological and dendroclimatological features of a mixedLarix decidua‐Pinus cembraforest at the timberline in the eastern Italian Alps at fine geographical and temporal scales. Forest structure variables such as stem diameter, tree height, age and tree‐ring related parameters (yearly growth index, mean sensitivity, first order autocorrelation and some dendroclimatic variables) have been compared at various scale levels. We observed that most of the variables show positive autocorrelated structures due to both forest dynamics and fine‐scale driving forces, probably related to microrelief. Spatial structure of yearly indexed radial growth appears sensitive to extreme climatic events. Secondary succession after past disturbances drives the forest towards a structure governed by a gap regeneration dynamics that seems to ensure the different requirements of the two main tree species present. Small spatial scale studies of forest structures, especially if integrated to dendro‐ecological data, seem an efficient tool to assess the disturbance regime and species sensitivity to environmental change.
Demography of three dominant sedges under contrasting grazing regimes in the High Arctic
Authors: Tolvanen Anne , Schroderus Jyrki , Henry Gregory H.R.
Published: February 2007

Abstract. Tiller demography of Carex aquatilis ssp. stans, Carex membranacea, and Eriophorum angustifolium ssp. triste was investigated in ungrazed and grazed high arctic vegetation on central Ellesmere Island, Canada. Tiller birth, growth, flowering and death were studied from excavated clonal fragments, and tiller density and biomass were studied from excavated turfs. Five life‐cycle stages were determined: dormant buds, juvenile, mature, flowering and dead tillers. A stage‐based transition matrix model was developed to estimate the long‐term dynamics of the sedge populations and to compare life‐history strategies between ungrazed and grazed populations. Short‐term and retrospective models, based on the growth during the sampling year and during the lifetime of the clonal fragments, respectively, were compared to see how well the short‐term model can describe demography of long‐lived plants. According to the short‐term model, tiller populations were decreasing (λ < 1 except for C. membranacea), whereas the retrospective model indicated that the tiller populations were increasing. Tiller population growth rates did not differ between ungrazed and grazed habitats. Nevertheless, the similar growth rates may be obtained by balanced differences in the vital rates between plants of the two habitats. The plants in the ungrazed habitat tended to remain in their current life‐cycle stage, whereas plants in the grazed habitat moved quickly to the next stage and died earlier. C. aquatilis ssp. stans appears to gain a competitive advantage over the other species under intensive grazing, as indicated by the higher tiller density and greater below‐ground biomass in grazed vegetation. The greater amount of below‐ground biomass apparently buffers C. aquatilis ssp. stans against grazing better than the other species.
Choosing the best similarity index when performing fuzzy set ordination on binary data
Authors: Boyce Richard L. , Ellison Paula C.
Published: February 2007

Abstract. Fuzzy set ordination (FSO) may be used with either abundance data or binary (presence/absence) data. FSO requires a similarity index that returns values between 0 and 1. Many indices will do so, but their suitability for FSO has not been tested. Nine binary indices were evaluated in this study. Simulated plant community data sets were generated with COMPAS; they contained five levels of β‐diversity, two levels of qualitative noise, and two sampling arrangements (regular or random) along one gradient. Indices were evaluated with rank and linear correlations between the apparent ecological gradient positions generated by FSO and actual gradient positions; the abilities of the best‐performing indices to minimize the curlover effect were also compared. All indices performed best at intermediate levels of β‐diversity and with regular sampling. Five indices had consistently higher rank and linear correlations (Baroni‐Urbani & Buser, Jaccard, Kulczynski, Ochiai and Sørensen), whereas four were consistently lower (Faith, Russell & Rao, Rogers & Tanimoto and Simple Matching). There were no significant differences in curlover among the five best indices. A step‐across algorithm, a flexible shortest path adjustment, improved correlations and reduced curlover for the five best indices at higher β‐diversity levels. We recommend that one of the five best‐performing similarity indices be used with FSO on binary data; a flexible shortest path adjustment should also be employed at higher β‐diversities when possible.
Effect of flooding and draw‐down disturbance on germination from a seashore meadow seed bank
Authors: Jutila Heli M.
Published: February 2007

Abstract. The objective of this study was to investigate the effects of flooding and draw‐down on the germination from the coastal grassland seed banks and to determine whether the effect of flooding varies between the delta and the seashore. Seed bank samples were collected from three shore transects in SW Finland, two on the shore of the Baltic Sea and one on the delta of River Kokemäenjoki. Samples were germinated in non‐flooded and flooded conditions for over a month, after which both treatments were maintained in non‐flooded conditions. A total of 9267 seedlings of 47 species germinated and mean density of seeds in the soil was ca. 84 000/m2. Most of the seedlings were monocots (98%) and perennials (98%). Ca. 30–40% of the species found in the above‐ground vegetation had a seed bank including the majority of the most abundant species. The number of seeds and species richness increased as the organic layer became thicker. The organic layer was thicker in the seashore samples and the seed bank was significantly larger than in the delta. The flooding and draw‐down treatment significantly increased the number of germinating seedlings in the seashore and also increased species richness in two transects, one in the delta and the other in the seashore. Two species, Schoenoplectus tabernaemontani and Typha latifolia, had significantly higher germination in the flooded treatment than in the non‐flooded. Apparently, many species in these coastal grasslands have adapted to flood disturbance and for seeds of some species flooding may work as a positive signal, possibly breaking dormancy.
Hohokam Political Ecology and Vulnerability: Comments on Waters and Ravesloot
Authors: Ensor Bradley E. , Ensor Marisa O. , Vries Gregory W. De
Published: February 2007

Waters and Ravesloot (2001) test the assumption that natural river channel change caused periods of Hohokam cultural reorganization. However, they conclude that channel changes did not correlate with all periods and areas of significant cultural changes and that landscape alone cannot explain Hohokam transformations. An anthropological perspective on political ecology and disasters can explain why environmental processes and events differentially impact societies, differentially impact societies diachronically and differentially impact social groups within societies. We suggest that this perspective may explain the variability described by Waters and Ravesloot.
Consolidation and Hierarchy: Chiefdom Variability in the Mississippian Southeast
Authors: Beck Robin A.
Published: February 2007

Explaining variability among Mississippian period (A.D. 1000-1600) chiefdoms has become a key research aim for archaeologists in the southeastern United States. One type of variability, in which simple and complex chiefdoms are distinguished by the number of levels of regional hierarchy, has dominated chiefdom research in this part of the world. The simple-complex chiefdom model is less applicable to the Mississippian Southeast, however, as there is little empirical evidence that chiefdoms here varied along this quantitative dimension. This article offers a qualitative model in which regional hierarchies are distinguished by the manner in which authority is ceded or delegated between an apical or regional chief and constituent, community-level leaders; chiefly power may be ceded from local-level leaders upward to the regional chief or delegated from the regional chief downward to local leaders. This apical-constituent model addresses variation in the administrative structures of chiefdoms: it is not a chiefdom typology. The model is used to contrast two Mississippian polities, Moundville in west-central Alabama and Powers Fort in southeastern Missouri, and illustrates variability in the process by which local communities were integrated into regional institutions.
Calibrated Radiocarbon Dating at Keatley Creek: The Chronology of Occupation at a Complex Hunter-Gatherer Village
Authors: Prentiss William C. , Lenert Michael , Foor Thomas A. , Goodale Nathan B. , Schlegel Trinity
Published: February 2007

This paper provides an analysis of radiocarbon dates acquired during earlier and recent field seasons at the Keatley Creek site, southern British Columbia. Results indicate that early occupations predating 1900 cal. B.P. occurred, but were not likely associated with population aggregation and large housepits. The aggregated village appears to have emerged by approximately 1700 cal. B.P. and was abandoned at approximately 800 cal. B.P. A break in the occupational sequence is recognized at 1450-1350 cal. B.P. and one other short break may have occurred shortly after 1250 cal. B.P. Peak socioeconomic complexity appears to have been achieved between 1350 and 800 cal B.P. Climatic warming may have provided a selective environment favoring population aggregation and intensification during this time. The final abandonment of the Keatley Creek village appears to have been part of a regional phenomenon suggesting the possibility that climatic factors were important in this case as well.
The Sourcing and Interpretation of Cahokia-Style Figurines in the Trans-Mississippi South and Southeast
Authors: Emerson Thomas E. , Hughes Randall E. , Hynes Mary R. , Wisseman Sarah U.
Published: February 2007

Exchange of preciosities is often considered an integral factor in the emergence of Mississippian chiefdoms, and the rise of Cahokia has been linked to such long-distance trade. We know that Cahokia was the center of production for large flint clay figurines and effigy pipes (Emerson and Hughes 2000). Similar Cahokia-style figures have been found in the Trans-Mississippi South and the Southeast. We investigated the material used.to make these figures using a newly developed nondestructive PIMA SP™ spectroscopic technology to identify the stone and to determine their source location. These analyses proved that the figures were made of Missouri flint clay from quarries near St. Louis. We submit that Cahokia was the twelfth-century source for the production of these Cahokia-style figures. Outside of Cahokia the flint clay figures were primarily found in Caddoan mortuaries, reinforcing earlier evidence of a strong Cahokia-Caddoan connection. The available chronological and contextual information indicates the flint clay figures left Cahokia after it began to decline in the late thirteenth-century, through various mechanisms of extra-local exchange rather than as part of any systematic prestige-goods network. The association of these highly symbolic figures with Cahokia allows us to reevaluate the indigenous iconography and propose that many of the themes (e.g., fertility and warfare) that later appear in Eastern Woodlands native cosmology such as the Southeastern Ceremonial Complex were first codified here in the twelfth-century.
Three Ounces of Sea Shells and One Fish Bone do not a Coastal Migration Make
Authors: Turner Christy G.
Published: February 2007

The suggestion by Jones et al. (2002) that a terminal Pleistocene-early Holocene California site contains evidence for a separate coastal migration into the New World is challenged. The authors ignore the fact that some 100 or more generations passed since the initial New World colonization event(s) and the occupation of their site (Cross Creek), during which time many cultural changes could be expected, including post-big-game-hunting coastal adaptations throughout the Americas. Moreover, the amount of food refuse is so minuscule that inferring the exact nature of the initial Cross Creek economy is doubtful at best. The recovered chipped stone artifacts have no diagnostic value for economic function or ecological correlation, and the grinding stones suggest more seed than sea exploitation. Lastly, what is known about the biological origins, variation, and microevolution of Native Americans does not support a direct coastal migration from Siberia to California.
Source Attribution and the Utilization of Obsidian in the Maya Area
Authors: Moholy-Nagy Hattula
Published: February 2007

Assignment by instrument of Maya obsidian artifacts to geological sources has demonstrated the presence of several sources and variations in their distribution over time and space. Of special interest is the minor, but long-standing, presence of green and gray obsidian from Central Mexico. More attributions of large, carefully selected samples are necessary to continue the considerable progress already achieved in understanding Maya obsidian procurement and use. However, assignment by visual means is not an appropriate method for the Maya area because of the range of optical characteristics exhibited by gray Guatemalan and Central Mexican obsidians, some of which are common to several geological sources. Moreover, the determination of obsidian sources must not be considered an end in itself. Combining source results with behavioral typology and archaeological data can further our understanding of obsidian procurement and use in past cultural context. Finally, it would be helpful if analysts reported trace element composition in a standardized manner, so that archaeologists can easily compare the results from different laboratories.
Nohoch Ek Revisited: The Minor Center as Manor
Authors: Taschek Jennifer T. , Ball Joseph W.
Published: February 2007

Over the last half-century, Maya archaeologists have variously identified “minor centers” as small-scale ceremonial or administrative centers, elite residential compounds, dower houses, manor houses, astronomical stations or markers, and boundary markers. Arguments for these identifications have ranged from simple assertions to elaborate analyses. What has emerged most clearly is that, as with any form of monolithic type, the “minor center” category—based in this case on relative size—represents something of a functionally mixed hodgepodge. Such architectural complexes in fact served and represented a multiplicity of as yet incompletely appreciated sociocultural functions and roles. We examine one such center, Nohoch Ek, and its likely role within the Late to Terminal Classic social landscape of the upper Belize Valley, based on investigations carried out by the authors in 1985, and by Michael Coe and William Coe in 1949. The study combines in-depth artifactual, depositional, and contextual analyses of an extensive body of data that was recovered using strategically placed purposive stripping and sampling trenches. We conclude that Classic period Nohoch Ek looked and functioned very much like a medieval European agricultural manor.
The Organization of Staple Crop Production at K'axob, Belize
Authors: Henderson Hope
Published: February 2007

This study examines variability in size, staple crop production, and wealth among households in the community of K'axob, Belize, from the ninth century B.C. until the ninth century A.D. Staple crop consumption and production are reconstructed from stable bone isotopes of 25 adults from 21 households. The formation of larger corporate households is documented from the spatial layout of 62 residences. Wealth differentiation is reconstructed by comparing architectural and ritual elements from 69 households. The formation of larger corporate households, the diversification of staple crop production, and the emergence of interhousehold wealth differentiation beginning in the fourth century B.C. coincided with the emergence of regional elites. However, changes in household size and staple crop production should be understood in terms of the high degree of continuity in the local agrarian economy. These findings suggest that elite political strategies had repercussions for the ways farming households managed staple crop production but that elites did not directly control production. The study also expands on current models of complex society that question the degree to which political elites directly managed the agrarian economy.
Städtebau as Imperial Culture: Camillo Sitte's Urban Plan for Ljubljana
Authors: Herscher Andrew
Published: February 2007

Camillo Sitte's planning work has rarely been examined as anything other than an application of the theory laid out in his treatise, City Planning According to Artistic Principles (1899). However, Sitte's theoretical precepts alone do not account for the transnational geography of his practice. Sitte's work as a planner developed around the distinction between Vienna, the imperial capital, where he was never able to influence urban development, and the empire's predominantly Slavic provinces, where almost all of his projects were commissioned. Focusing on the preparation of Sitte's plan for Ljubljana in 1895, this essay relates the theoretical formulation and practical application of city planning to two dynamics that dominated late-nineteenth-century Austro-German liberal culture: the appropriation of humanist Italian culture by scientific art and architectural history, and the redeployment of that culture as professional expertise in a putatively uncultured eastern Europe.
Local Elites and the Reformation of Late Intermediate Period Sociopolitical and Economic Organization in Nasca, Peru
Authors: Conlee Christina A.
Published: February 2007

The Late Intermediate Period (A.D. 1000–1476) was a time between empires in the Andes when many regional groups reorganized and gained power. In the Nasca drainage this period has often been misrepresented, in part due to a focus on earlier cultural developments that were considerably different. Recent research attempts to provide a clearer picture of this time period by investigating sociopolitical and economic organization, and in particular the nature of local elites. Regional settlement patterns reveal that during this period population in the drainage was at its height with increased aggregation at town-size settlements. Excavations at the small village site of Pajonal Alto have identified local elites through variations in architecture and material culture. Evidence from Pajonal Alto reveals that there was a reformation of society in the Late Intermediate Period and local elites were no longer primarily associated with ceremonial centers but instead were present at every level of the settlement hierarchy. Elites obtained and maintained power in a variety of ways including participation in the production of utilitarian items, exchange, feasting, and community/exclusive ritual. Instead of integration through communal ritual on a regional level during certain times of the year, integration was based on a large network of local elites who had power that was wielded on a day-to-day basis.
Indigenous Ware or Spanish Import? The Case of Indígena Ware and Approaches to Power in Colonial Mexico
Authors: Rodríguez-Alegría Enrique , Neff Hector , Glascock Michael D.
Published: February 2007

For the last two decades, archaeologists have believed that a ceramic type known as Indígena Ware was an imitation of European majolica, produced by colonial Nahuas in Mexico City for lower-class Spanish families. Ideas surrounding the production and consumption of Indígena Ware, as well as majolica in general, have been based on the concepts of Spanish domination and indigenous acculturation. These ideas emphasize European interests in displaying high-value imports to obtain distinction along racial and class lines, and fail to consider indigenous strategies for obtaining power through craft production and display. We begin by critically evaluating the stylistic, iconographic, and technical evidence archaeologists have used to suggest that Indígena Ware was an indigenous product. We present the results from neutron activation analysis of 250 ceramic sherds indicating that Indígena Ware forms its own compositional group, different from Aztec pottery and Spanish majolica, and suggest that Indígena Ware is most likely a Spanish import. The problems this ware presents for classification reveal the limitations of locating power exclusively in the hands of the Spanish and point to ways in which we could overcome this theoretical problem for the study of colonialism in Mexico.
Transcutaneous ultrasonographic evaluation of gastric distension with fluid in horses
Authors: Lores Marcos , Stryhn Henrik , McDuffee Laurie , Rose Patricia , Muirhead Tammy
Published: February 2007

Objective—To develop a transcutaneous ultrasonography (TUS) method for measuring the location of the stomach during various levels of fluid distension and evaluate any correlation between gastric fluid distension and stomach position.

Animals—6 adult horses.

Procedures—Known volumes of water were administered in 2 trials. In trial 1, the stomach was evaluated prior to and after the administration of 2, 4, and 6 L of water. In trial 2, the stomach was evaluated after administration of 6, 8, 10, and 12 L of water. The TUS was performed at the 7th through 16th left intercostal spaces (ICSs). For each volume of water, an image was captured at the most dorsal point in each ICS where the dorsolateral aspect of the stomach wall was viewed. The distance between this point and a horizontal line drawn on the skin at the level of the elbow joint was measured. The measurements at all ICSs were used to estimate the gastric wall height at ICS 12, which was subsequently evaluated for statistical association with volume administered.

Results—Significant correlation between the estimated height of the stomach wall at ICS 12 and the volume of fluid administered was detected. A regression equation to estimate gastric fluid volume when initial values for gastric wall height (cm) at ICS 12 and fluid volume (L) are known was developed.

Conclusions and Clinical Relevance—Results suggested that use of TUS for gastric fluid volume estimation is a potentially useful technique.
Evaluation of the repeatability of rhinomanometry and its use in assessing transnasal resistance and pressure in dogs
Authors: Wiestner Thomas S. , Koch Daniel A. , Nad Natascha , Balli Aaron , Roos Malgorzata , Weilenmann Richard , Michel Erika , Arnold Susanna
Published: February 2007

Objective—To evaluate a modified posterior rhinomanometric method for clinical application in dogs.

Animals—15 healthy Beagles and 8 Bulldogs (4 healthy and 4 with respiratory problems).

Procedures—Rhinomanometry was performed 3 times within a 15-minute period in anesthetized dogs.Transnasal pressure (PNA) and nasal resistance (RNA) were determined by use of artificial airflow (adjusted for body weight) for inspiration (PNAin and RNAin, respectively) and expiration (PNAout and RNAout). Procedures were repeated for the Beagles 7 days later.

Results—For the Beagles, mean ± SD of PNAin for both days (0.162 ± 0.042 kPa) was significantly lower than PNAout (0.183 ± 0.053 kPa). Similarly, RNAin (1.47 ± 0.41 kPa/[L/s]) was significantly lower than RNAout (1.64 ± 0.46 kPa/[L/s]). Pairwise comparison of values for PNA and RNA for the 2 days revealed no significant difference. Repeatability of the method (estimated as within-day variation) for RNA was ± 0.19 kPa/(L/s), whereas variation between the days was ± 0.36 kPa/(L/s) for RNAin and ± 0.44 kPa/(L/s) for RNAout. The 4 clinically normal Bulldogs had RNA values ranging from 1.69 to 3.48 kPa/(L/s), whereas in the 4 Bulldogs with respiratory problems, RNA ranged from 9.83 to 20.27 kPa/(L/s).

Conclusions and Clinical Relevance—RNA is inversely dependent on body size and nonlinearly associated with airflow. We propose that RNA in dogs should be determined for airflows standardized on the basis of body size. The PNA and RNA in Beagles can be measured with sufficient repeatability for clinical use and nasal obstructions are detectable.
Subtotal penile amputation and preputial urethrostomy in a dog
Authors: Pavletic Michael M. , O'Bell Susan A.
Published: February 2007

Case Description—A 6-year-old castrated male Shih Tzu was evaluated because of intermittent bleeding during urination.

Clinical Findings—Necrosis of the cranial portion of the penile shaft extended distally from the preputial fornix. Penile necrosis secondary to strangulation from paraphimosis was diagnosed.

Treatment and Outcome—A midline preputiotomy incision was used to expose the penile shaft; amputation was performed caudal to the preputial fornix. The terminal portion of the urethra was anastomosed to the preputial mucosa, which allowed the dog to urinate through the preputial orifice.

Clinical Relevance—Unlike the more conventional urethrostomy procedures performed in dogs, preputial urethrostomy eliminates the potential for local skin irritation during urination. Preputial urethrostomy is also easier to perform in those dogs in which penile amputation is required adjacent to the preputial fornix. A release incision cranial to the prepuce can be used to facilitate caudal displacement of the preputial mucosa, which facilitates urethral anastomosis to this structure. A midline preputiotomy incision provided excellent exposure of the penile shaft for this surgical procedure.
Comparative study of layered tetravalent metal phosphates containing various first-row divalent metals. Synthesis, crystalline structure
Authors: Szirtes László , Riess László , Megyeri János , Kuzmann Ernõ
Published: February 2007

The transition metal forms of α-zirconium-. titanium-, and hafnium phosphates were prepared by ion exchange method. Their structure was investigated by X-ray powder diffraction (XRPD) method. It was found that the transition metal containing phosphates have the same layered structure as the pristine tetravalent metal phosphates, except for the increase of interlayer distance from 7.6 Å to ∼9.5 Å. As a result of the incorporation of transition metals in the layers, the c-axis is increased from ∼15 Å to ∼20 Å (in the case of titanium phosphate to ∼25 Å). All other parameters (a, b and β °) are practically unchanged.
Voltammetric quantitation at the mercury electrode of the anticholinergic drug flavoxate hydrochloride in bulk and in a pharmaceutical formulation
Authors: Ghoneim M.M. , El-Attar M.A. , Razeq S.A.
Published: February 2007

Flavoxate hydrochloride, 2-piperidinoethyl 3-methyl-4-oxo-2-phenyl-4-H-chromene-8-carboxylate, is a smooth muscle antispasmodic. Its electrochemical behavior was studied at the mercury electrode in buffered solutions containing 30% (v/v) methanol using dc-polarography, differential-pulse polarography, cyclic voltammetry, and linear sweep-and square-wave adsorptive stripping voltammetry. Sensitive and precise procedures were developed for determination of bulk flavoxate hydrochloride and in the pharmaceutical formulation Genurin® S.F, without sample pretreatment or extraction. Limits of quantitation (LOQ) of 1 × 10−5, 5 × 10−6, 1 × 10−8 and 1 × 10−9 M flavoxate hydrochloride were achieved by dc-polarography, differential-pulse polarography, linear sweep and square-wave adsorptive stripping voltammetric, respectively.
A theoretical investigation on the isomerism and the NMR properties of thiosemicarbazones
Authors: Nuwan De Silva N. , Albu Titus
Published: February 2007

Hybrid density functional theory calculations at the mPW1PW91/6-31+G(d,p) level of theory have been used to investigate the optimized structures and other molecular properties of five different series of thiosemicarbazones. The investigated compounds were obtained from acenaphthenequinone, isatin and its derivatives, and alloxan. The focus of the study is the isomerism and the NMR characterization of these thiosemicarbazones. It was found that only one isomer is expected for thiosemicarbazones and methylthiosemicarbazones, while for dimethylthiosemicarbazones, two isomers are possible. All investigated thiosemicarbazones exhibit a hydrazinic proton that is highly deshielded and resonates far downfield in the proton NMR spectra. This proton is a part of a characteristic sixmembered ring, and its NMR properties are a result of its strong, intermolecular hydrogen bond. The relationships between the calculated 1H and 13C NMR chemical shifts and various geometric parameters are reported.
Effects of Exogenous Oxytocin on Embryonic Survival in Cows
Authors: Yildiz A. , Erisir Z.
Published: February 2007

The aim of this study was to evaluate the effect of oxytocin on embryonic survival in dairy cows. Pregnancy was verified using the early pregnancy factor (EPF) activity on Day 4 after artificial insemination (AI). Pregnant cows were randomly allotted to two groups: treated (n = 8) and control (n = 8). Oxytocin (100 IU, 5 ml, DIF Turkey) was administered twice daily by intravenous injections to treated cows and sterile saline (5 ml) to control cows immediately before milking on days 4 to 7 after AI. Blood samples were taken via jugular vein every day from day 4 to 8 and every other day until Day 20 following insemination to evaluate the effect of oxytocin on embryonic survival. The embryonic loss was diagnosed in 3 of the 8 cows treated with oxytocin, and embryonic survival rate was 62.5% in this group versus 87.5% in controls. Short cycles occurred in 37.5% of oxytocin-treated cows. At the same time their serum progesterone concentrations rose more slowly than in controls. It was concluded that cows administered oxytocin on days 4 to 7 after insemination are at a higher risk of pregnancy loss.
Gastric Helicobacter-like Organisms in Stray Cats
Authors: Erginsoy S. D. , Sözmen M. , Özcan K.
Published: February 2007

Ten adult domestic shorthaired stray cats (Felis catus) were investigated for the presence and localization of different species of gastric Helicobacter-like organisms (GHLOs) using Warthin-Starry silver staining, immunohistochemistry and transmission electron microscopy (TEM); the severity and distribution of lesions in different regions of the stomach were assessed in HE-stained sections. GHLOs were present in all areas of the stomach in all of 10 cats. Three morphologically different types of spiral-shaped bacteria were demonstrated; in silver-stained sections, H. pylori like organisms (HPLO) were easily differentiated from other GHLOs. Eight of the cats had H. heilmannii-like organisms (HHLOs) and one cat had HPLO. Mixed H. heilmannii and H. felis infection was seen in only one cat. GHLO infection was associated with a mild to severe gastritis in 8 of 10 cats. GHLOs colonized the cardia, corpus and antrum in similar density. The most striking histopathological changes consisted of accumulation of lymphocytes and neutrophilic granulocytes, fibrosis of the lamina propria mucosae, lymphoid follicles and lymphocytic infiltrates. There was no obvious relation between the degree of colonization by GHLOs and the extent of histopathological changes. GHLOs were present on the mucosal surface, in the lumen of gastric glands, and in the cytoplasm of parietal cells. These findings indicate that immunohistochemistry and silver staining are useful for detecting GHLO infections, particularly with different Helicobacter species present. Stray cats are frequently colonized by HHLOs without any significant correlation between the degree of infection and gastritis score; in contrast HPLOs and HFLOs infections are not very common.
Nitrite Toxicity to Danio Rerio: Effects of Fish Age and Chloride Concentrations
Authors: Voslářová E. , Pištěková V. , Svobodová Z.
Published: February 2007

The aim of the present study was to compare the acute nitrite toxicity for Danio rerio at the age of 20-25 days (larval stage) and 2-3 months (juvenile stage) at various chloride concentrations. The semistatic method according to OECD 203 was used in the tests. The 96hLC50 NO2- value was 386.00 ± 29.75 mg l-1 (D. rerio aged 20-25 days), and 242.41 ± 13.67 mg l-1 (D. rerio aged 2-3 months), respectively, at 19 mg Cl- l-1 in diluting water. We observed an increase in 96hLC50 NO2- in D. rerio of both developmental stages following an increase in Cl- concentration in diluting water. A comparison between the 96hLC50 NO2- determined for D. rerio aged 20-25 days and those aged 2-3 months at different chloride concentrations in diluting water (19; 50; 100 mg l-1) showed a highly significant increase (p < 0.01) in the 96hLC50 NO2- for the younger fish at all chloride concentrations. An exponential relationship between 96hLC50 NO2- values and chloride concentrations in diluting water (I = 0.849) was demonstrated in D. rerio aged 20-25 days while a logarithmical relationship (I = 0.856) was observed in D. rerio aged 2-3 months.
Early Mobilization in a Removable Cast Compared with Immobilization in a Cast after Operative Treatment of Ankle Fractures: A Prospective Randomized Study
Authors: Vioreanu Mihai , Dudeney Sean , Hurson Brian , Kelly Eamon , O'Rourke Kieran , Quinlan William
Published: February 2007

Background: The aim of operative treatment for ankle fractures is to allow early movement after internal fixation. The hypothesis of this study was that early mobilization would improve functional recovery in patients after surgery for ankle fractures. Methods: In a prospective randomized controlled study, 66 consecutive patients with ankle fractures that required open reduction and internal fixation (ORIF) were assigned to one of two postoperative regimens: immobilization in a nonweightbearing below-knee cast or early mobilization in a removable cast. Four patients were excluded from the study, leaving 62 for review. Results: Patients who had early mobilization in a removable cast had higher functional scores (Olerud-Molander and AOFAS) at 9 and 12 weeks postoperatively. They also returned to work earlier (67 days) compared with those treated in nonweightbearing below-knee cast (95 days), p < 0.05. There was no statistical difference in Quality of Life (SF-36 Questionnaire) at 6 months between the two groups. We had an approximately 10% postoperative infection trend (one superficial and two deep) in the early mobilization group. Conclusion: Despite the overall short-term benefit of early mobilization, we had three patients in the early mobilization group who had wound complications. Both the surgeon and patient should be aware of the higher risk of wound complications associated with this treatment, and thus the accelerated rehabilitation protocol should be individualized.
Chronic Lateral Instability: Arthroscopic Findings and Long-Term Results
Authors: Ferkel Richard D. , Chams Roger N.
Published: February 2007

Background: A wide variety of procedures have been described to treat chronic lateral ankle instability. Nonanatomic procedures sacrifice normal tissue and can restrict motion. Anatomic reconstruction of the anterior talofibular and calcaneofibular ligaments, supplemented by reefing of the exstensor retinaculum (modified Broström procedure) provides good long-term stability with minimal drawbacks. Methods: Twenty-one patients had arthroscopic evaluation followed by the Gould modification of the Broström procedure. All patients filled out a detailed questionnaire, including the American Orthopaedic Foot and Ankle Society Ankle/Hindfoot Score, Modified Weber Score, and Hamilton Score at an average of 60 months after surgery. All patients were re-examined, and 14 had stress radiographs for comparison with the preoperative films. Results: Ninety-five percent of the patients (20 of 21) had associated intra-articular problems. The mean score for the Modified Weber Score was 96; for the Ankle/Hindfoot Score, 97; and for the Hamilton score, 100% good and excellent results. All 14 patients recorded a side-to-side difference of less than 3 degrees on their postoperative stress radiographs. Conclusions: A high percentage of patients with lateral ankle instability have intra-articular pathology. Excellent results can be expected in patients with ankle instability who undergo arthroscopic treatment of associated intra-articular pathology and the modified Broström procedure.
Highly Efficient Orange and Green Solid‐State Light‐Emitting Electrochemical Cells Based on Cationic IrIII Complexes with Enhanced Steric Hindrance
Authors: Su H.‐C. , Fang F.‐C. , Hwu T.‐Y. , Hsieh H.‐H. , Chen H.‐F. , Lee G.‐H. , Peng S.‐M. , Wong K.‐T. , Wu C.‐C.
Published: February 2007

Highly efficient orange and green emission from single‐layered solid‐state light‐emitting electrochemical cells based on cationic transition‐metal complexes [Ir(ppy)2sb]PF6 and [Ir(dFppy)2sb]PF6 (where ppy is 2‐phenylpyridine, dFppy is 2‐(2,4‐difluorophenyl)pyridine, and sb is 4,5‐diaza‐9,9′‐spirobifluorene) is reported. Photoluminescence measurements show highly retained quantum yields for [Ir(ppy)2sb]PF6 and [Ir(dFppy)2 sb]PF6 in neat films (compared with quantum yields of these complexes dispersed in m‐bis(N‐carbazolyl)benzene films). The spiroconfigured sb ligands effectively enhance the steric hindrance of the complexes and reduce the self‐quenching effect. The devices that use single‐layered neat films of [Ir(ppy)2sb]PF6 and [Ir(dFppy)2sb]PF6 achieve high peak external quantum efficiencies and power efficiencies of 7.1 % and 22.6 lm W–1) at 2.5 V, and 7.1 % and 26.2 lm W–1 at 2.8 V, respectively. These efficiencies are among the highest reported for solid‐state light‐emitting electrochemical cells, and indicate that cationic transition‐metal complexes containing ligands with good steric hindrance are excellent candidates for highly efficient solid‐state electrochemical cells.
Formation of a Ground‐State Charge‐Transfer Complex in Polyfluorene//[6,6]‐Phenyl‐C61 Butyric Acid Methyl Ester (PCBM) Blend Films and Its Role in the Function of Polymer/PCBM Solar Cells
Authors: Benson‐Smith J. J. , Goris L. , Vandewal K. , Haenen K. , Manca J. V. , Vanderzande D. , Bradley D. D. C. , Nelson J.
Published: February 2007

Evidence is presented for the formation of a weak ground‐state charge‐transfer complex in the blend films of poly[9,9‐dioctylfluorene‐co‐N‐(4‐methoxyphenyl)diphenylamine] polymer (TFMO) and [6,6]‐phenyl‐C61 butyric acid methyl ester (PCBM), using photothermal deflection spectroscopy (PDS) and photoluminescence (PL) spectroscopy. Comparison of this polymer blend with other polyfluorene polymer/PCBM blends shows that the appearance of this ground‐state charge‐transfer complex is correlated to the ionization potential of the polymer, but not to the optical gap of the polymer or the surface morphology of the blend film. Moreover, the polymer/PCBM blend films in which this charge‐transfer complex is observed also exhibit efficient photocurrent generation in photovoltaic devices, suggesting that the charge‐transfer complex may be involved in charge separation. Possible mechanisms for this charge‐transfer state formation are discussed as well as the significance of this finding to the understanding and optimization of polymer blend solar cells.
Replication and Coating of Silica Templates by Hydrothermal Carbonization
Authors: Titirici M.‐M. , Thomas A. , Antonietti M.
Published: February 2007

Hierarchical carbon materials with functional groups residing at the surface are prepared for the first time by using nanostructured silica materials as templates in combination with hydrothermal carbonization at mild temperatures (180 °C). Different carbon morphologies (e.g., macroporous casts, hollow spheres, carbon nanoparticles, and mesoporous microspheres) can be obtained by simply altering the polarity of the silica surface. The surface functionality and hydrophilicity of the resulting materials are assessed by Fourier transform IR spectroscopy, X‐ray photoelectron analysis, and water porosimetry. Raman spectroscopy and X‐ray diffraction measurements show that the materials are of the carbon‐black type, similar to charcoal.
Atomistic Study of a CaTiO3‐Based Mixed Conductor: Defects, Nanoscale Clusters, and Oxide‐Ion Migration
Authors: Mather G. C. , Islam M. S. , Figueiredo F. M.
Published: February 2007

Mixed oxide‐ion and electronic conductivity can be exploited in dense ceramic membranes for controlled oxygen separation as a means of producing pure oxygen or integrating with catalytic oxidation. Atomistic simulation has been used to probe the energetics of defects, dopant‐vacancy association, nanoscale cluster formation, and oxide‐ion transport in mixed‐conducting CaTiO3. The most favorable energetics for trivalent dopant substitution on the Ti site are found for Mn3+ and Sc3+. Dopant‐vacancy association is predicted for pair clusters and neutral trimers. Low binding energies are found for Sc3+ in accordance with the high oxide‐ion conductivity of Sc‐doped CaTiO3. The preferred location for Fe4+ is in a hexacoordinated site, which supports experimental evidence that Fe4+ promotes the termination of defect chains and increases disorder. A higher oxide‐ion migration energy for a vacancy mechanism is predicted along a pathway adjacent to an Fe3+ ion rather than Fe4+ and Ti4+, consistent with the higher observed activation energies for ionic transport in reduced CaTi(Fe)O3–δ.
Photochemical Formation of Au/Cu Bimetallic Nanoparticles with Different Shapes and Sizes in a Poly(vinyl alcohol) Film
Authors: Sakamoto M. , Tachikawa T. , Fujitsuka M. , Majima T.
Published: February 2007

Metal nanoparticle (NP)–polymer nanocomposite thin films are attractive for applications in various devices. Since bimetallic NPs provide additional opportunities for tuning the physical properties of the NP components, the development of bimetallic NP nanocomposite thin films should lead to further enhancements of various applications. Au/Cu bimetallic NPs are fabricated in a poly(vinyl alcohol) (PVA) film using a photochemical process. Interestingly, different sizes and shapes of Au/Cu bimetallic NPs are formed in the PVA film, resulting in a uniquely patterned nanocomposite structure. It is determined that the different formation and growth mechanisms of NPs inside and outside the UV‐light irradiation spot leads to the differences in size and shape.