bluuebunny/crossref_metadata_2025_split huggingface dataset:
Image processing techniques to quantify microprojections on outer corneal epithelial cells
Authors: Julio Gemma , Merindano Ma Dolores , Canals Marc , Ralló Miquel 
Published: May 2008

AbstractIt is widely accepted that cellular microprojections (microvilli and/or microplicae) of the corneal surface are essential to maintain the functionality of the tissue. To date, the characterization of these vital structures has been made by analysing scanning or transmission electron microscopy images of the cornea by methods that are intrinsically subjective and imprecise (qualitative or semiquantitative methods). In the present study, numerical data concerning three microprojection features were obtained by an automated method and analysed to establish which of them showed less variability. We propose that the most stable microprojection characteristic would be a useful sign in early detection of epithelial damage or disease. With this aim, the scanning electron microscopy images of 220 corneal epithelial cells of nine rabbits were subjected to several image processing techniques to quantify microprojection density, microprojection average size and surface covered by microprojections (SCM). We then assessed the reliability of the methods used and performed a statistical analysis of the data. Our results show that the thresholding process, the basis of all image processing techniques used in this work, is highly reliable in separating microprojections from the rest of the cell membrane. Assessment of histogram information from thresholded images is a good method to quantify SCM. Amongst the three studied variables, SCM was the most stable (with a coefficient of variation of 15.24%), as 89.09% of the sample cells had SCM values ≥ 40%. We also found that the variability of SCM was mainly due to intercellular differences (the cell factor contribution represented 88.78% of the total variation in the analysed cell areas). Further studies are required to elucidate how healthy corneas maintain high SCM values.
Cranial performance in the Komodo dragon (Varanus komodoensis) as revealed by high‐resolution 3‐D finite element analysis
Authors: Moreno Karen , Wroe Stephen , Clausen Philip , McHenry Colin , D’Amore Domenic C. , Rayfield Emily J. , Cunningham Eleanor 
Published: May 2008

AbstractThe Komodo dragon (Varanus komodoensis) displays a unique hold and pull‐feeding technique. Its delicate ‘space‐frame’ skull morphology differs greatly from that apparent in most living large prey specialists and is suggestive of a high degree of optimization, wherein use of materials is minimized. Here, using high‐resolution finite element modelling based on dissection and in vivo bite and pull data, we present results detailing the mechanical performance of the giant lizard's skull. Unlike most modern predators, V. komodoensis applies minimal input from the jaw muscles when butchering prey. Instead it uses series of actions controlled by postcranial muscles. A particularly interesting feature of the performance of the skull is that it reveals considerably lower overall stress when these additional extrinsic forces are added to those of the jaw adductors. This remarkable reduction in stress in response to additional force is facilitated by both internal and external bone anatomy. Functional correlations obtained from these analyses also provide a solid basis for the interpretation of feeding ecology in extinct species, including dinosaurs and sabre‐tooth cats, with which V. komodoensis shares various cranial and dental characteristics.
The presence and absence of prosencephalic cell groups relaying striatal information to the medial and lateral thalamus in tenrec
Authors: Künzle Heinz 
Published: May 2008

AbstractAlthough there are remarkable differences regarding the output organization of basal ganglia between mammals and non‐mammals, mammalian species with poorly differentiated brain have scarcely been investigated in this respect. The aim of the present study was to identify the pallidal neurons giving rise to thalamic projections in the Madagascar lesser hedgehog tenrec (Afrotheria). Following tracer injections into the thalamus, retrogradely labelled neurons were found in the depth of the olfactory tubercle (particularly the hilus of the Callejal islands and the insula magna), in subdivisions of the diagonal band complex, the peripeduncular region and the thalamic reticular nucleus. No labelled cells were seen in the globus pallidus. Pallidal neurons were tentatively identified on the basis of their striatal afferents revealed hodologically using anterograde axonal tracer substances and immunohistochemically with antibodies against enkephalin and substance P. The data showed that the tenrec's medial thalamus received prominent projections from ventral pallidal cells as well as from a few neurons within and ventral to the cerebral peduncle. The only regions projecting to the lateral thalamus appeared to be the thalamic reticular nucleus (RTh) and the dorsal peripeduncular nucleus (PpD). On the basis of immunohistochemical data and the topography of its thalamic projections, the PpD was considered to be an equivalent to the pregeniculate nucleus in other mammals. There was no evidence of entopeduncular (internal pallidal) neurons being present within the RTh/PpD complex, neuropils of which did not stain for enkephalin and substance P. The ventrolateral portion of RTh, the only region eventually receiving a striatal input, projected to the caudolateral rather than the rostrolateral thalamus. Thus, the striatopallidal output organization in the tenrec appeared similar, in many respects, to the output organization in non‐mammals. This paper considers the failure to identify entopeduncular neurons projecting to the rostrolateral thalamus in a mammal with a little differentiated cerebral cortex, and also stresses the discrepancy between this absence and the presence of a distinct external pallidal segment (globus pallidus).
Immunohistochemical distribution of regulatory peptides in the human fetal adenohypophysis
Authors: Reyes R. , Valladares F. , Gutiérrez R. , González M. , Bello A. R. 
Published: May 2008

AbstractWe have studied here the cellular distribution of several regulatory peptides in hormone‐producing cells of the human pituitary during the fetal period. Immunohistochemistry was used to show the expression of several regulatory peptides, namely Angiotensin‐II, Neurotensin and Galanin, at successive gestational stages and their co‐localization with hormones in the human fetal adenohypophysis. Somatotrophs, gonadotrophs and thyrotrophs were differentiated earliest. At gestational week 9, Angiotensin‐II immunoreactivity was co‐localized only with growth hormone immunoreactivity in somatotrophs, one of the first hormone‐producing cells to differentiate. This co‐localization remained until week 37. Neurotensin immunoreactivity was present in gonadotrophs and thyrotrophs in week 23, after FSH and TSH hormone differentiation. Galanin immunoreactivity was present in all hormone‐producing cell types except corticotrophs. The different pro‐opiomelanocortin‐derived peptides were detected at different stages of gestation and adrenocorticotrophic hormone immunoreaction was the last to be detected. Our results show an interesting relationship between regulatory peptides and hormones during human fetal development, which could imply that these peptides play a regulatory role in the development of pituitary function.
Calibration of estimated biting forces in domestic canids: comparison of post‐mortem and in vivo measurements
Authors: Ellis Jennifer Lynn , Thomason Jeffrey J. , Kebreab Ermias , France James 
Published: May 2008

AbstractEstimates of biting forces are widely used in paleontological and comparative studies of feeding mechanics and performance, and are usually derived from lever models based on measurements made on the skull that are relevant to the mechanics of the masticatory system. Owing to assumptions and unmeasurable errors in their estimation, such values are used comparatively rather than as absolute estimates. The purpose of this paper was to provide calibration of post‐mortem calculated bite force estimates by comparing them to in vivo forces derived from a sample of 20 domestic dogs (Canis familiaris) during muscle stimulation under general anaesthesia. Two lever models previously described in the literature were used to estimate post‐mortem values, and regression analysis was also performed to derive best‐fit equations against a number of morphometric measurements on the skull. The ranges of observed forces in vivo were 147–946 N at the canine, and 524–3417 N at the second molar. The lever models substantially underestimated these forces, giving mean values between 39% and 61% of the observed means. Predictability was considerably improved by removing the linear bias and deviation of the regression slope from unity with an adjustment equation. Best‐fit statistical models developed on these animals performed considerably better (calculated means within 0.54% of observed means) and included easily measureable variables such as bodyweight, dimensions of the temporalis fossa and out‐lever from the jaw joint to the biting tooth. These data should lead to more accurate absolute, rather than relative, estimates of biting forces for other extant and fossil canids, and other carnivorans by extrapolation.
Redistribution and loss of soil organic carbon by overland flow under various soil management practices on the Chinese Loess Plateau
Authors: Jin K. , Cornelis W. M. , Schiette W. , Lu J. J. , Buysse T. , Baert G. , Wu H. J. , Yao Y. , Cai D. X. , Jin J. Y. , De Neve S. , Hartmann R. , Gabriels D. 
Published: May 2008

AbstractField rainfall simulations with intensities of 85 and 170 mm/h were conducted in 2002 and 2005 on a 15‐m long slope on a loess soil in Luoyang, Henan Province, P. R. China to study the effects of different soil management practices on the redistribution and loss of soil organic carbon (SOC) by runoff and soil erosion. Field plots under winter wheat (Triticum aestivumL.) were set up in 2001 and included the following soil management practices: subsoiling with mulch (SSM), no‐till with mulch (NTM), reduced tillage (RT) and conventional tillage control (CT). The results showed that SOC for topsoil (0–20 cm) increased in the NTM and SSM plots when compared with results from 2002 and 2005. For all treatments, SOC in the lower part of the plots was higher in 2005 than in 2002. The values from the upper parts of the plots were only lower in 2005 compared with the overall values for 2002 for RT and CT. The enrichment ratio of organic carbon (ERoc) in runoff sediment varied from 1.01 to 2.24 with a mean of 1.25. During the simulated rainfall events, ERocwas initially high and then reduced after a short period to reach a steady value at the end of the event, always remaining ≥1. The change in SOC loss rate was more dependent on the sediment loss rate than on the changes in SOC concentration in the sediment. The best results in terms of a reduction in soil and SOC loss were obtained with NTM: no runoff and hence no soil and SOC loss were observed. SOC losses observed for SSM were on average only 4% of those observed for CT. RT resulted in 71% SOC loss compared with CT although the runoff reduction was not pronounced. For farmers, SSM and NTM are the best alternatives in terms of SOC conservation. NTM has the additional advantage that it requires less labour and is more beneficial from economic and environmental perspectives.
An evaluation of furrows for managing soil and water loss from a shallow Alfisol under simulated rainfall
Authors: Mishra P. K. , Vasudeva Reddy Ch. , Satish Kumar U. 
Published: May 2008

AbstractFurrows are widely used in rainfed areas of semi‐arid India for soil and water conservation. The orientation of furrows, either down or across slope, and their spacing influence the effectiveness of furrows as soil and water conservation measures. We evaluated treatments with furrows aligned down and across 3% sloping land at spacings of 90, 60 and 30 cm under simulated rainfall intensities of 80 and 100 mm/h on a shallow Alfisol. A bare plot without any furrows was considered as a control. A large (24 m × 3 m) rainfall simulator developed at the Central Research Institute for Dryland Agriculture (CRIDA), Hyderabad, was used for this controlled study. Run‐off was measured by a calibrated tipping bucket run‐off recorder. The effects of the treatments on peak flow rate (L/s), sediment loss with run‐off water (kg/ha/mm), peak sediment concentration (g/L), run‐off (per cent rainfall) and time to peak (min) were investigated. When compared with the control (no furrows), across slope furrowing with 60‐ and 30‐cm spacing reduced sediment yields by 19.9 and 21.3 kg/ha/mm of run‐off, respectively, under a rainfall intensity of 80 mm/h and 24 and 25.3 kg/ha/mm of run‐off, respectively, under a rainfall intensity of 100 mm/h. For the control, sediment loss was 50.72 kg/ha/mm run‐off and 56.68 kg/ha/mm run‐off for rainfall intensities of 80 and 100 mm/h, respectively. Similar trends were recorded from observations of peak flow, time to peak and peak sediment concentration. Run‐off hydrographs demonstrated the conservation value of across slope furrowing by delaying run‐off initiation, reducing run‐off and slowly releasing the run‐off after the cessation of rainfall. The results show that furrow orientation has major effects on reducing run‐off, whereas furrow spacing has insignificant effects.
Deinking paper fibre application to agricultural land: soil quality enhancer or copper polluter?
Authors: Tandy S. , Williamson J. C. , Nason M. A. , Healey J. R. , Jones D. L. 
Published: May 2008

AbstractShort‐fibre paper residuals (deinking paper fibre (DPF) or paper mill sludge) represents a major waste formed during the processing of recycled paper and is known to contain significant quantities of copper. It is often spread onto agricultural land to help increase soil pH and improve structure by adding soil organic matter (SOM). A number of agricultural sites in England and Wales that had received large and repeated applications were sampled to investigate the long‐term effects of this practice on soil quality and plant copper content. We found that the composition of DPF waste has changed significantly between 1999 and 2006 with concentrations of Cu increasing and organic matter content declining. Whilst repeated additions of DPF to agricultural land always increased soil Cu, an associated increase in SOM was not always apparent. There was no link between SOM and bioavailable Cu nor between soil bioavailable Cu and plant Cu. In contrast to previous reports, our findings indicate that improvement in soil quality following the long‐term application of DPF was site‐specific and in some cases it may have reduced soil quality rather than enhanced it.
Soil loss tolerance values for different physiographic regions of Central India
Authors: Lakaria Brij Lal , Biswas H. , Mandal D. 
Published: May 2008

AbstractIn India, a single soil loss tolerance (T) value of 11.2 Mg/ha is by default used for formulating land restoration strategies for all soil types, climates and vegetation covers. However, this single ‘T’ value does not represent a true picture of soil loss tolerance under all land uses. The objective of our study was to develop adjusted ‘T’ values for Central India using soil infiltration rate, bulk density, total organic carbon, erodibility and soil pH. Soil state was defined using a quantitative model involving different soil functions which were used to convert soil parameters to a 0 to 1 scale. The normalized values were then multiplied by appropriate weighing factors based on relative importance and sensitivity analysis of each indicator. Based on overall assessment, each soil mapping unit was categorized into soil groups I, II or III. A general guideline of USDA – Natural Resource Conservation Service (USDA‐NRCS) was followed to calculate soil loss tolerance for each soil group using effective soil depth. Adjusted ‘T’ values for Central India ranged from 2.5 to 12.5 Mg/ha compared with a default value of 11.2 Mg/ha. Use of these values for soil mapping units will improve conservation planning and assist with planning the development of sustainable agriculture.
Asthma Pharmacotherapy Prescribing in the Ambulatory Population of the United States: Evidence of Nonadherence to National Guidelines and Implications for Elderly People
Authors: Navaratnam Prakash , Jayawant Sujata S. , Pedersen Craig A. , Balkrishnan Rajesh 
Published: May 2008

OBJECTIVES: To examine the level of physician adherence to the Expert Panel Report 2 (EPR‐2) pharmacotherapy guidelines of the asthma population, specifically in the elderly ambulatory patient population of the United States.DESIGN: Retrospective cross‐sectional study using a national survey.SETTING: National Ambulatory Medical Care Survey data of U.S. elderly patients from 1998 through 2004.PARTICIPANTS: The weighted population sample size was 82,020,318 patients. There were 1,540 observations in this study (preweighted sample size) and 96 strata, with 446 population sampling units (PSUs). There were 11,868,340 patients that were elderly, and they accounted for 14.5% of the overall population sampled.MEASUREMENTS: Specific patient demographic variables, physician demographic variables, and information about asthma medications prescribed were extracted from the data set and analyzed. Descriptive statistics for the patient demographic, physician demographic, and asthma pharmacotherapy variables were generated. A series of logistic regression models were created, with the choice of asthma pharmacotherapy agent used as the dependent variable and patient and physician demographic variables as the independent variables.RESULTS: A major finding was that physicians were not adherent to the National Asthma Education and Prevention Program EPR‐2 asthma pharmacotherapy guidelines. Another finding was that, although elderly patients (aged ≥65) were exposed to more‐stable patterns of care, they were less likely to be prescribed controller medications, long‐acting bronchodilators (LABAs), combinations of inhaled corticosteroids and LABAs, and short‐acting beta agonists than patients aged 35 to 64.CONCLUSION: A more‐concerted effort needs to be undertaken to improve physician adherence to the EPR‐2 guidelines, especially in prescribing asthma pharmacotherapy to elderly patients.
Effects of the Location of Myocardial Infarction on the Spectral Characteristics of Ventricular Fibrillation
Authors: SÁNCHEZ‐MUÑOZ JUAN J. , ROJO‐ÁLVAREZ JOSÉ L. , GARCÍA‐ALBEROLA ARCADIO , EVERSS ESTRELLA , REQUENA‐CARRIÓN JESÚS , ORTIZ MERCEDES , ALONSO‐ATIENZA FELIPE , VALDÉS‐CHAVARRI MARIANO 
Published: May 2008

Background: The location of the myocardial infarction (MI) might modify the spectral characteristics of ventricular fibrillation (VF) in humans.
Objective: To evaluate the effect of the location of the infarcted area on the spectral parameters of VF.
Methods: Patients with chronic MI (29 anterior, 32 inferior) and induced VF during cardioverter defibrillator implant were retrospectively studied. Dominant frequency (fd), organization index (OI), and power of the harmonic peaks were calculated in the device‐stored electrograms (EGM) during sinus rhythm (SR) and VF.
Results: The fd of the VF was not affected by the left ventricular ejection fraction (LVEF) or the MI location (anterior: 4.54 ± 0.74 Hz, inferior: 4.77 ± 0.48 Hz, n.s.). The OI was also similar in both groups. However, in patients with inferior MIs, normalized peak power at fd was higher (118.3 ± 18.5 vs 100.6 ± 28.2, P < 0.01) and the normalized peak power of the harmonics was lower than in the anterior MI group. The analysis of EGM during SR showed similar results. The size of the necrotic area and its distance to the recording electrode might partially explain these results.
Conclusion: In our series, the spectral characteristics of the EGMs during VF showed significant differences depending on the MI localization. A higher fraction of energy (in the low‐frequency region) was seen in inferior MIs, whereas the peak power at the harmonics increased in anterior MIs. A similar effect was seen during SR and VF, suggesting that it is caused by local electrophysiology abnormalities induced by the MI rather than by different intrinsic characteristics of the VF.
Time Course of Effects of Cardiac Resynchronization Therapy in Chronic Heart Failure: Benefits in Patients with Preserved Exercise Capacity
Authors: PIEPOLI MASSIMO F , VILLANI GIOVANNI Q , CORRÀ UGO , ASCHIERI DANIELA , RUSTICALI GUIDO 
Published: May 2008

Objectives: To assess in patients with chronic heart failure the effect of cardiac resynchronization therapy (CRT) over 12 months' follow‐up the time course of the changes in functional and neurohormonal indices and to identify responders to CRT.
Methods: Eighty‐nine patients (74.1 ± 1 years, left ventricular ejection fraction [LVEF] < 35%), QRS complex duration >150 ms, in stable New York Heart Association (NYHA) class III or IV on optimal medical treatment were prospectively randomized either in a control (n = 45) or CRT (n = 44) group and underwent clinical evaluation, cardiopulmonary exercise testing (CPET), 2D‐Echo, heart rate variability (HRV), carotid baroreflex (BRS), and BNP assessments before and at 6‐ and 12‐month follow‐up.
Results: In the CRT group, improvement of cardiac indices and BNP concentration were evident at medium term (over 6 months) follow‐up, and these changes persisted on a longer term (12 months) (all P < 0.05). Instead CPET indices and NYHA class improved after 12 months associated with restoration of HRV and BRS (all P < 0.05). We identified 26 responders to CRT according to changes in LVEF and diameters. Responders presented less depressed hemodynamic (LVEF 25 ± 1.0 vs 22 ± 0.1%), functional (peak VO2 10.2 ± 0.2 vs 6.9 ± 0.3 ml/kg/min), and neurohormonal indices (HRV 203.6 ± 15.7 vs 147.6 ± 10.ms, BRS 4.9 ± 0.2 vs 3.6 ± 0.3 ms/mmHg) (all P < 0.05). In the multivariate analysis, peak VO2 was the strongest predictor of responders.
Conclusions: Improvement in functional status is associated with restoration of neurohormonal reflex control at medium term. Less depressed functional status (peak VO2) was the strongest predictor of responders to CRT.
Does Size Really Matter? A Comparison of the Riata Lead Family Based on Size and Its Relation to Performance
Authors: CORBISIERO RAFFAELE , ARMBRUSTER REBECCA 
Published: May 2008

Background:Recently, the performance and safety of smaller diameter implantable cardioverter defibrillator (ICD)leads has been questioned. The purpose of this analysis was to determine the impact of size on lead performance and perforation rates by comparing the performance of 7 French (7F) and 8 French (8F) leads with similar design characteristics implanted by a single operator.Methods:Patients implanted with a Riata 1580 (8F) or 7000 (7F) series leads (St. Jude Medical, Sylmar, CA, USA) over a 2‐year period were evaluated to compare performance and perforation rates.Results:There were 357 Riata 8F leads and 357 Riata 7F leads implanted in 714 patients. Follow‐up ranged from 1 to 24 months. The 8F leads were implanted in the right ventricular apex more often than were 7F leads (129 or 37% vs 72 or 20%, P < 0.0001). Oversensing that did not result in therapy occurred in 2 pts (0.56%) with 8F leads and 1 pt. (0.28%) with a 7F lead (P = 0.56). Oversensing with therapy occurred once in both groups (0.28%, P = NS). One perforation occurred in each group (0.28%, P = NS). Both occurred in leads that were implanted in the right ventricular apex (P = 0.02).Conclusions:The performance of St. Jude Medical 7F and 8F Riata leads was similar. The incidence of lead‐related adverse events was within or below the low end of published acceptable ranges for ICD lead perforation and sensing anomalies. Perforations were less likely to occur in leads that were implanted in nonapical positions.