bluuebunny/crossref_metadata_2025_split huggingface dataset:
Can arable field margins be managed to enhance their biodiversity, conservation and functional value for soil macrofauna?
Authors: Smith J. , Potts S. G. , Woodcock B. A. , Eggleton P. 
Published: November 2007

SummaryThe establishment of grassy strips at the margins of arable fields is an agri‐environment scheme that aims to provide resources for native flora and fauna and thus increase farmland biodiversity. These margins can be managed to target certain groups, such as farmland birds and pollinators, but the impact of such management on the soil fauna has been poorly studied. This study assessed the effect of seed mix and management on the biodiversity, conservation and functional value of field margins for soil macrofauna.Experimental margin plots were established in 2001 in a winter wheat field in Cambridgeshire, UK, using a factorial design of three seed mixes and three management practices [spring cut, herbicide application and soil disturbance (scarification)]. In spring and autumn 2005, soil cores taken from the margin plots and the crop were hand‐sorted for soil macrofauna. The Lumbricidae, Isopoda, Chilopoda, Diplopoda, Carabidae and Staphylinidae were identified to species and classified according to feeding type.Diversity in the field margins was generally higher than in the crop, with the Lumbricidae, Isopoda and Coleoptera having significantly more species and/or higher abundances in the margins. Within the margins, management had a significant effect on the soil macrofauna, with scarified plots containing lower abundances and fewer species of Isopods. The species composition of the scarified plots was similar to that of the crop.Scarification also reduced soil‐ and litter‐feeder abundances and predator species densities, although populations appeared to recover by the autumn, probably as a result of dispersal from neighbouring plots and boundary features. The implications of the responses of these feeding groups for ecosystem services are discussed.Synthesis and applications. This study shows that the management of agri‐environment schemes can significantly influence their value for soil macrofauna. In order to encourage the litter‐dwelling invertebrates that tend to be missing from arable systems, agri‐environment schemes should aim to minimize soil cultivation and develop a substantial surface litter layer. However, this may conflict with other aims of these schemes, such as enhancing floristic and pollinator diversity.
As the raven flies: using genetic data to infer the history of invasive common raven (Corvus corax) populations in the Mojave Desert
Authors: FLEISCHER ROBERT C. , BOARMAN WILLIAM I. , GONZALEZ ELENA G. , GODINEZ ALVARO , OMLAND KEVIN E. , YOUNG SARAH , HELGEN LAUREN , SYED GRACIA , MCINTOSH CARL E. 
Published: November 2007

AbstractCommon raven (Corvus corax) populations in Mojave Desert regions of southern California and Nevada have increased dramatically over the past five decades. This growth has been attributed to increased human development in the region, as ravens have a commensal relationship with humans and feed extensively at landfills and on road‐killed wildlife. Ravens, as a partially subsidized predator, also represent a problem for native desert wildlife, in particular threatened desert tortoises (Gopherus agassizii). However, it is unclear whether the more than 15‐fold population increase is due to in situ population growth or to immigration from adjacent regions where ravens have been historically common. Ravens were sampled for genetic analysis at several local sites within five major areas: the West Mojave Desert (California), East Mojave Desert (southern Nevada), southern coastal California, northern coastal California (Bay Area), and northern Nevada (Great Basin). Analyses of mtDNA control region sequences reveal an increased frequency of raven ‘Holarctic clade’ haplotypes from south to north inland, with ‘California clade’ haplotypes nearly fixed in the California populations. There was significant structuring among regions for mtDNA, with high FST values among sampling regions, especially between the Nevada and California samples. Analyses of eight microsatellite loci reveal a mostly similar pattern of regional population structure, with considerably smaller, but mostly significant, values. The greater mtDNA divergences may be due to lower female dispersal relative to males, lower Ne, or effects of high mutation rates on maximal values of FST. Analyses indicate recent population growth in the West Mojave Desert and a bottleneck in the northern California populations. While we cannot rule out in situ population growth as a factor, patterns of movement inferred from our data suggest that the increase in raven populations in the West Mojave Desert resulted from movements from southern California and the Central Valley. Ravens in the East Mojave Desert are more similar to ones from northern Nevada, indicating movement between those regions. If this interpretation of high gene flow into the Mojave Desert is correct, then efforts to manage raven numbers by local control may not be optimally effective.
Statistical issues on the analysis of change in follow‐up studies in dental research
Authors: Blance Andrew , Tu Yu‐Kang , Baelum Vibeke , Gilthorpe Mark S. 
Published: November 2007

AbstractObjective:  To provide an overview to the problems in study design and associated analyses of follow‐up studies in dental research, particularly addressing three issues: treatment‐baselineinteractions; statistical power; and nonrandomization.Background:  Our previous work has shown that many studies purport an interacion between change (from baseline) and baseline values, which is often based on inappropriate statistical analyses. A priori power calculations are essential for randomized controlled trials (RCTs), but in the pre‐test/post‐test RCT design it is not well known to dental researchers that the choice of statistical method affects power, and that power is affected by treatment‐baseline interactions. A common (good) practice in the analysis of RCT data is to adjust for baseline outcome values using ancova, thereby increasing statistical power. However, an important requirement for ancova is there to be no interaction between the groups and baseline outcome (i.e. effective randomization); the patient‐selection process should not cause differences in mean baseline values across groups. This assumption is often violated for nonrandomized (observational) studies and the use of ancova is thus problematic, potentially giving biased estimates, invoking Lord's paradox and leading to difficulties in the interpretation of results.Methods:  Baseline interaction issues can be overcome by use of statistical methods; not widely practiced in dental research: Oldham's method and multilevel modelling; the latter is preferred for its greater flexibility to deal with more than one follow‐up occasion as well as additional covariates To illustrate these three key issues, hypothetical examples are considered from the fields of periodontology, orthodontics, and oral implantology.Conclusion:  Caution needs to be exercised when considering the design and analysis of follow‐up studies. ancova is generally inappropriate for nonrandomized studies and causal inferences from observational data should be avoided.
Optimization of Acetylene Black Conductive Additive and Polyvinylidene Difluoride Composition for High Power Rechargeable Lithium-Ion Cells
Authors: Liu Gao , Zheng Honghe , Battaglia Vince , Simens Amanda S. , Minor Andrew M. , Song Xiangyun 
Published: November 2007

Fundamental electrochemical methods were applied to study the effect of the acetylene black (AB) conductive additive and the polyvinylidene difluoride (PVDF) polymer binder on the performance of high-power designed rechargeable lithium ion cells. A systematic study of the AB/PVDF long-range electronic conductivity at different ratios is performed using four-point	probe direct current tests and the results reported. There is	a wide range of AB/PVDF ratios that satisfy the long-range electronic conductivity requirement of the lithium-ion cathode electrode; however, a significant cell power performance improvement is observed at small AB/PVDF composition ratios	that are far from the long-range conductivity optimum of 0.8 to 1. Electrochemical impedance spectroscopy and the hybrid power pulse characterization tests indicate that the impedance decreases significantly with increase in binder content. We believe the higher binder contents lead to a more cohesive conductive carbon particle network that results in better overall all local electronic conductivity on the active	material surface and hence reduced charge transfer impedance.
Physisorption of Hydrogen on Boron-Containing Carbon (B/C) Material Prepared by Organoborane Precursor
Authors: Chung T. C. M. , Chen Wei , Zhang Zhicheng 
Published: November 2007

This paper discusses the synthesis of boron substituted carbon (B/C) materials by pyrolysis of two organic and polymeric precursors, which are prepared by chloroboration of phenylene acetylene and phenyl diacetylene, respectively. Some of the	resulting B/C materials were evaluated in hydrogen physisorption from ambient to low temperatures under various hydrogen pressures. Evidently, through the precursor design it is possible to transform some B atoms in the precursor into B/C material by pyrolysis. Despite the dense structure (without significant porosity by SEM and BET), the B/C material with 1.6 wt% B content shows hydrogen absorption 0.7 and 2.15 wt% at 25	and -78 oC, respectively, under 1300 psi hydrogen pressure. The adsorption-desorption cycles were repeated many times without any detectable change. Apparently, the empty p-orbital in the substituted B atom increases the binding energy of hydrogen to the B/C surface of graphitic platelet , which is reversible by pressure and ambient temperature.
Fermentation, Phlogiston and Matter Theory: Chemistry and Natural Philosophy in Georg Ernst Stahl's Zymotechnia Fundamentalis
Authors: Chang Ku-Ming 
Published: November 2007

AbstractThis paper examines Georg Ernst Stahl's first book, the Zymotechnia Fundamentalis, in the context of contemporary natural philosophy and the author's career. I argue that the Zymotechnia was a mechanical theory of fermentation written consciously against the influential "fermentational program" of Joan Baptista van Helmont and especially Thomas Willis. Stahl's theory of fermentation introduced his first conception of phlogiston, which was in part a corpuscular transformation of the Paracelsian sulphur principle. Meanwhile some assumptions underlying this theory, such as the composition of matter, the absolute passivity of matter and the "passions" of sulphur, reveal the combined scholastic and mechanistic character of Stahl's natural philosophy. In the conclusion I show that Stahl's theory of fermentation undermined the old fermentational program and paved the way for his dualist vitalism.
Locke, Bacon and Natural History
Authors: Anstey Peter R. 
Published: November 2007

AbstractThis paper argues that the construction of natural histories, as advocated by Francis Bacon, played a central role in John Locke's conception of method in natural philosophy. It presents new evidence in support of John Yolton's claim that "the emphasis upon compiling natural histories of bodies ... was the chief aspect of the Royal Society's programme that attracted Locke, and from which we need to understand his science of nature". Locke's exposure to the natural philosophy of Robert Boyle, the medical philosophy of Thomas Sydenham, his interest in travel literature and his conception of the division of the sciences are examined. From this survey, a cumulative case is presented which establishes, independently of an in-depth exegesis of his Essay Concerning Human Understanding, the central role for Locke of the construction of natural histories in natural philosophy.
Clinical Evaluation of Vascoray (Sodium Iothalamate 26%/Methylglucamine Iothalamate 52%)—a New Contrast Medium
Authors: Marshall T.R. 
Published: November 2007

A clinical comparison and use of a new salt mixture of iothalamate—Vascoray (sodium iothalamate 26%/methylglucamine iothalamate 52%)—with Conray (methylglucamine iothalamate 60%), Conray-400 (sodium iothalamate, 66.8%), Hypaque-M 75% (sodium diatrizoate 25%/methylglucamine diatrizoate 50%) and Angio-Conray (sodium iothalamate 80%) has been carried out. The sodium solutions were found to produce more major and minor side effects, to have the lowest viscosity, and be more irritating to the myocardium, cerebral circulation, and spinal cord. The methylglucamine solutions had fewer side effects, but a greater viscosity for a similar iodine content. A combination of the sodium and methylglucamine salts of iothalamate and diatrizoate produced fewer side effects in the procedures compared, Table III. The iothalamate compound produced fewer side effects than the diatrizoate compound, Table III. Vascoray is a sterile solution of 400 mg of organically bound iodine per ml (40% iodine). Each ml contains 260 mg of sodium and 520 mg of methylglu camine as mixed salts of iothalamic acid and not more than 0.15 mg sodium biphosphate as a buffer. This compound was formulated because of the increas ing need for an agent with fewer major and minor side effects for aortography and angiocardiography. It has a viscosity of 14.0 centipoises at 25°C, and 9.0 centipoises at 37.5°C. The intravenous LD 50 (mice) for methylglucamine iothalamate 60% is 17,000 mg/kg; sodium iothalamate 66.8% is 19,000 mg/kg; sodium iothalamate 26%/ methylglucamine iothalamate 52% is 18,000 mg/kg; and sodium iothalamate 80% is 21,000 mg/kg, Table I. Hayes2 has reported that all standardized toxic ity studies comparing iothalamate preparations and diatrizoate preparations proved the iothalamate preparations to be less toxic than the diatrizoate prepa rations as regards neurotoxicity, nephrotoxicity and cardiopulmonary toxicity. Gensini3 has suggested that the methylglucamine salt may be safer than the sodium salt in the coronary arteries, myocardium and spinal cord tissues. So dium salts are more toxic to the spinal cord, coronary arteries and myocardium than the methylglucamine salts. Methylglucamine salts are generally accepted as less toxic than sodium salts; however, they have a higher viscosity than sodium solutions. The combination of the two salts reduced the side effects while maintaining adequate flow rates, since the sodium solution has a lower viscosity and faster flow rate. This new agent combines the low toxicity-high viscosity of methylglucamine iothalamate with somewhat higher toxicity-lower viscosity of sodium iothalamate.
Pathophysiology of Capillary Circulation: Raynaud's Disease
Authors: Arnot R.S. , Boroda C. , Peacock J.H. 
Published: November 2007

Despite the frequency of Raynaud's disease in cold climates, the etiology of the condition remains uncertain. This report reviews the literature since Raynaud's original description and Lewis and Pickering's addition to the concept, and several recent observations which add to our understanding of the disease are discussed. We investigated the effect of posture and a vasodilator drug on the digital capillary circulation; digital blood flow increases as the body moves from a recumbent, through a sitting, to an upright position. Bradilan, a vasodilator drug, increases the circulation in the recumbent and sitting positions, but has no effect in standing patients, despite symptomatic relief.
Exercise Tests in Patients With Severe Angina Pectoris: An Angiographic Correlation
Authors: Eshchar Y. , Yahini J.H. , Atlas P. , Kishon Y. , Deutsch V. , Neufeld H.N. 
Published: November 2007

Graded submaximal ergometric tests were performed on 60 patients who suffered from clinically severe angina pectoris, and the results were correlated with their coronary angiograms. The test was positive in 44, negative in 9, and undetermined in 7 patients (defined as failure to reach the target heart rate without ischemic ST changes). Among patients with positive tests, 42 (95%) had obstruction of one to three coronary vessels. Among patients with negative tests, only 3 had significant coronary disease (sensitivity 93%). While all patients suffered clinically from severe "angina pectoris," 8 (15%) had insignificant CAD, and among them 6 had a negative and 2 a false-positive exercise response (specificity 75%). Although ST depression was a good indicator of CAD, its degree did not parallel the severity of the lesions. The peak heart rate on exercise of patients with ischemic ST changes was lower than their target heart rate, suggesting that the heart rate at which ST changes occur constitutes in itself a good indicator of severity. Among the 7 patients with undetermined tests, CAD was found in 6. In these patients the absence of ST changes may be ascribed to extensive myocardial fibrosis, and the only clue to CAD resides in the negative chronotropic response to exercise. Although exercise testing does not always distinguish between normal and CAD patients, it nevertheless constitutes a valuable noninvasive technique for the detection of the high-risk patients.
Reactive Hyperemia in Patients With Intermittent Claudication, and Correlation With Other Diagnostic Methods
Authors: Clement Denis L. , Brugmans J. 
Published: November 2007

The value of blood flow measurements was evaluated in 16 patients with in termittent claudication and in 17 healthy sex and age-matched volunteers. Limb volume was recorded with an ECG-triggered venous occlusion ple thysmograph (Periflow, Janssen), and the flow values were automatically plotted on a second channel. Resting blood flow was similar in both groups, but all the parameters from the reactive hyperemia curve in the claudication group were significantly different from those in the control group.6 The present data are preliminary in this respect. In most patients visual inspection of the curve allows differentiation of nor mal and abnormal. Variability of the flow parameters is found to be small; the time-to-peak flow varies the most, but gives at the same time the largest differ ent results in both groups. Finally, there is a positive correlation between rest ing blood flow, peak blood flow, and walking distance. The present results sug gest that flow measurements provide valuable and objective information about the degree of functional distress caused by obliterative vascular diseases in the limbs.
Mitral Valve Prolapse: Whiplike Motion of the Posterior Mitral Leaflet Detected by Two-Dimensional Echocardiography
Authors: Kounis Nicholas G. 
Published: November 2007

Thirty-four patients with symptoms suggesting mitral valve prolapse were evaluated by M-mode echocardiography, real time, two-dimensional, phased array echocardiography, and cardiac catheterization. Ten of these patients had unequivocal evidence of mitral valve prolapse during cardiac catheterization. This diagnosis was established initially by M-mode and two-dimensional echo cardiographic techniques. A characteristic "whiplike" motion of the posterior mitral leaflet was seen in 7 patients. The posterior mitral leaflet was moving successively toward the left atrium and left ventricle during the cardiac cycle. Arching of one or both mitral leaflets was also seen in patients with mitral valve prolapse during two-dimen sional echocardiography. Two-dimensional echocardiography significantly en hances the mitral valve prolapse evaluation, but further experience and better techniques are necessary to explain many of the signs associated with this ab normality.
Blood Fluidity as a Consequence of Red Cell Fluidity: Flow Properties of Blood and Flow Behavior of Blood in Vascular Diseases
Authors: Schmid-Schönbein H. , Rieger H. , Fischer T. 
Published: November 2007

Blood is known to be an extremely non-Newtonian material, the fluidity (or reciprocal of viscosity) of which can vary in vivo between that of plasma alone and zero, that is, the total lack of fluidity in the absence of coagulation. The fluidity of blood under high driving pressures and in small blood vessels is un usually high when compared to that of all other known suspensions or emul sions. The high fluidity of blood is caused by the fluidity of the red cells, which adapt to the forces of flow and participate in flow much like fluid droplets. When subjected to high forces the blood behaves dynamically like an emulsion of extremely low viscosity. In the absence of adequate flow forces, the erythro cytes are aggregated into rouleaux and rouleaux networks, which render to blood the properties of a reticulated suspension. Under these flow conditions, the fluidity of blood strongly decreases if the hematocrit value is normal or slightly elevated. If the flow forces fall below a critical level, the fluidity ap proaches zero, under which conditions the flow of blood ceases altogether (de spite the presence of residual driving pressures). The fluidity of blood is further jeopardized by an enhanced tendency to aggregation and biochemical erythro cyte rigidification, for example, by lactacidosis, hyperosmolarity, or loss of ATP. However, an actual loss of fluidity under these conditions occurs only if the biochemical changes are strictly associated with a drop in driving pressures (locally or generally). Restitution of blood fluidity can be achieved most simply by isovolumic he modilution, by defibrinogating agents, or by drugs that protect against rigid ifying effects of acidosis or other biochemical sequelae of stagnation anoxia.
The Thoracic Outlet Syndrome: An Assessment of 20 Cases with Regard to New Clinical and Electromyographic Findings
Authors: Glassenberg Myron 
Published: November 2007

Twenty patients with a clinically documented thoracic outlet syndrome were studied with regard to their clinical and electromyographic findings. Certain vascular as well as neurologic signs were noted to be prominent, particularly the presence of a supraclavicular bruit as well as reproduction of the patient's symptomatology while doing the thoracic outlet stress test. Other findings such as interossei weakness, ulnar nerve hypalgesia, supracla vicular tenderness to deep palpation, and reproduction of the patient's symptomatology via bilateral shoulder opposition were noted to be present. Classical maneuvers used to diagnose the thoracic outlet syndrome were compared and the thoracic outlet stress test was shown to be the best clinical test available at the present time. In addition, electromyographic studies were done which showed abnormalities in only 55% of the cases when using multiple parameters that have been described in the literature recently. A new nerve conduction procedure was described here in which nerve conductions over the ulnar nerves were obtained in the thoracic outlet stress position and found, in a few cases, to show a reduction in amplitude of the evoked potential obtained at the hypothenar eminence. In addition, some findings suggestive of cervical radiculopathy were noted in the cases studied and several possible explanations for this were discussed.