bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic model for the effects of K fertilizer on crop growth, K‐uptake and soil‐K in arable cropping. 2. Field test of the model
Authors: Greenwood D. J. , Karpinets T. V. 
Published: February 2007

Abstract. The validity of the model described in Greenwood & Karpinets (1997) was tested against the results of single year, multi level K fertilizer experiments. Measurements of plant mass, %K in the plant and K activity ratio in soil had been made at harvest and at intervals during the growing season on spring wheat, summer cabbage and turnips. Reasonably good agreement was obtained between these measurements and simulated values when the two ‘crop’ parameters (defining the dependence of critical and maximum possible %K on plant mass) were adjusted for each crop. Also good agreement was generally obtained for plant weight and plant %K at harvest in less detailed experiments on 10 other crops. Values of the two ‘crop’ parameters for 12 of the crops were strongly correlated with one another suggesting that a single ‘crop’ parameter may be all that is required to define most inter‐species differences in plant‐K demand.Simulations with the model indicate that, in central England, no response of 10 crops to K fertilizer would be likely on soils containing more than 170 mg of 1 M ammonium nitrate extractable‐K/kg of soil and having clay contents of between 15 and 45%. Shortcomings of the model and opportunities for advance are discussed.A simplified version of the model runs on the Internet at: http://www.qpais.co.uk/moda‐djg/potass.htm
Fluxes of methane between landfills and the atmosphere: natural and engineered controls
Authors: Bogner J. , Meadows M. , Czepiel P. 
Published: February 2007

Abstract. Field measurement of landfill methane (CH4) emissions indicates natural variability spanning more than seven orders of magnitude, from less than 0.0004 to more than 4000 g/m2 per day. This wide range reflects net emissions resulting from production (methanogenesis), consumption (methanotrophic oxidation), and gaseous transport processes. The determination of an ‘average’ emission rate for a given field site requires sampling designs and statistical techniques which consider spatial and temporal variability. Moreover, particularly at sites with pumped gas recovery systems, it is possible for methanotrophic microorganisms in aerated cover soils to oxidize all of the CH4 from landfill sources below and, additionally, to oxidize CH4 diffusing into cover soils from atmospheric sources above. In such cases, a reversed soil gas concentration gradient is observed in shallow cover soils, indicating bidirectional diffusional transport to the depth of optimum CH4 oxidation. Rates of landfill CH4 oxidation from field and laboratory incubation studies range up to 166 g/m2 per day, among the highest for any natural setting, providing an effective natural control on net emissions. It has been shown that methanotrophs in landfill soils can adapt rapidly to elevated CH4 concentrations with increased rates of CH4 oxidation related to depth of oxygen penetration, soil moisture, and the nutrient status of the soil.Estimates of worldwide landfill CH4 emissions to the atmosphere have ranged from 9 to 70 Tg/y, differing mainly in assumed CH4 yields from estimated quantities of landfilled refuse. At highly controlled landfill sites in developed countries, landfill CH4 is often collected via vertical wells or horizontal collectors. Recovery of landfill CH4 through engineered systems can provide both environmental and energy benefits by mitigating subsurface migration, reducing surface emissions, and providing an alternative energy resource for industrial boiler use, on‐site electrical generation, or upgrading to a substitute natural gas. Manipulation of landfill cover soils to maximize their oxidation potential could provide a complementary strategy for controlling CH4 emissions, particularly at older sites where the CH4 concentration in landfill gas is too low for energy recovery or flaring. For the future, it is necessary to better quantify net emissions relative to rates of CH4 production, oxidation, and transport. Field measurements, manipulative studies, and model development are currently underway at various spatial scales in several countries
Double‐Wire Technique in Balloon‐Protected Carotid Artery Stenting
Authors: KAWARADA OSAMI , YOKOI YOSHIAKI , TAKEMOTO KAZUSHI , MORIOKA NOBUYUKI 
Published: February 2007

Objectives: To evaluate the safety and efficacy of a double‐wire technique in carotid artery stenting (CAS) with a distal occlusion balloon system, PercuSurge GuardWire.
Methods: Fifty‐one consecutive patients with 53 de novo lesions were scheduled to undergo balloon‐protected CAS with the “double‐wire technique,” the use of two wires, one for independent predilatation and the other for stent implantation.
Results: Fifty consecutive patients underwent a total of 52 balloon‐protected CAS except for 1 patient with one lesion that could not be accessed. The use of a 1.5‐mm coronary balloon was necessary in only 2 cases (3.8%) to let the PercuSurge GuardWire cross critically stenotic lesions. The placement of the PercuSurge GuardWire into the internal carotid artery was successful in all cases. Technical success was obtained in all cases. Fifty lesions (96.2%) were treated with one inflation of the distal occlusion balloon during the entire procedure consisting of predilatation, stent implantation, and aspiration, and among them three lesions (5.8%) required postdilatation. The mean occlusion time of cerebral blood flow for 50 lesions was 266 ± 37 seconds. Out of 50 procedures, 45 (90.0%) had occlusion times of 300 seconds or less. Neurological intolerance requiring intravenous anesthesia was seen in 4 cases (7.7%) and periprocedural neurological complication in 2 cases (3.8%).
Conclusions: The “double‐wire technique” is safe and effective for the shortening of occlusion time during predilatation, stent implantation, and aspiration, leading to satisfactory technical and clinical outcomes, in most cases. This technique should be considered for balloon‐protected CAS using the PercuSurge GuardWire.
Optimal supplier testing and tolerance strategies for genetically modified (GM) wheat
Authors: Wilson William W. , Dahl Bruce L. , Jabs Eric 
Published: February 2007

AbstractA stochastic optimization model was developed to determine optimal testing strategies, costs, and risks for dual marketing of genetically modified (GM) and non‐GM wheat in an export supply chain. The optimal testing strategy is derived that minimizes disutility of additional system costs due to testing and quality loss. Cost components were estimated including those related to testing, quality loss, and a risk premium to induce shippers to undertake dual marketing as opposed to handling only non‐GM crops. Uncertainties were incorporated for adventitious presence and commingling, variety declaration, and test accuracy. Sensitivities were performed for effects of variety risks and declaration, penalty differentials, buyer tolerances, risk aversion, and GM adoption. Results indicate testing and segregation can be performed at a relatively low cost and risk to buyers.
Economic implications of alternative mill mud management options in the Australian sugar industry
Authors: Qureshi Muhammad E. , Qureshi Sumaira E. , Wegener Malcolm K. 
Published: February 2007

AbstractSugar mills produce a range of byproducts during the process of extracting sugar from cane. Mill mud is one of the byproducts produced in significant volume. The practice of spreading mill mud onto cane fields close by the mill has been the primary means of disposing of mill mud for many years. The continued application of mill mud at high rates, without appropriate recognition of its nutrient content, the soil condition, crop nutrient requirements, slope of the land, or proximity of application sites to environmentally sensitive areas has raised a number of concerns in recent years, including overfertilization, heavy‐metal contamination, leaching, and offsite impacts from drainage to waterways. This study develops a regional mathematical programming model to determine optimal rates of mill mud application for various soil types and distances from the mill in the Mackay region in central Queensland, Australia. The optimal application rate of mill mud varies according to soil type and by distance from the mill. Lower rates of mill mud application are economically desirable at greater distances from the mill. However, when the cost of mill mud application is shared between growers and the mill operator, the optimal application rates are reduced at some locations while increasing at others.
Effect of limbal explant orientation on the histology, phenotype, ultrastructure and barrier function of cultured limbal epithelial cells
Authors: Raeder Sten , Utheim Tor Paaske , Utheim Øygunn Aass , Cai Yiqing , Roald Borghild , Lyberg Torstein , Kjeldsen‐Kragh Jens , Ramstad Hanne , Messelt Edvard , Nicolaissen Bjørn 
Published: February 2007

Abstract.Purpose:  To compare the histology, phenotype, ultrastructure and barrier function of cultured limbal epithelial cells using two explant culture protocols.Methods:  Epithelial cells were cultured for 16 days from limbal explants, positioned with either the stromal side (stromal group) or the epithelial side (epithelial group) on intact amniotic membranes. The cultured epithelium (n = 56) was examined using light microscopy, immunohistochemistry for K3, Cx43, ABCG2 and p63 expression, Western blot analysis of ΔNp63α, transmission electron microscopy, a horseradish peroxidase (HRP) permeability assay and scanning electron microscopy.Results:  The epithelial group demonstrated a significantly higher expression of p63‐positive cells (85.7 ± 4.2%) than the stromal group (75.3 ± 8.9%), and Western blots showed a stronger band of ΔNp63α. K3 and ABCG2 were not detected in either group, whereas Cx43 displayed moderate immunostaining in the suprabasal layer. The number of cell layers, the desmosome number and the undulation length in the epithelial group were not significantly different from those in the stromal group. In both groups, HRP accumulated on the apical surface of the superficial cells, and scanning electron microscopy demonstrated tightly apposed superficial cells.Conclusions:  Our findings indicate that limbal explants positioned epithelial side down may give rise to cultured epithelia with higher expression of p63 and ΔNp63α.
Clinical, social and psychosocial factors associated with self‐rated oral health in Brazilian adolescents
Authors: Pattussi Marcos P. , Olinto Maria Teresa Anselmo , Hardy Rebecca , Sheiham Aubrey 
Published: February 2007

Abstract –  Objective:  The objective of this study is to investigate the main social, psychosocial and clinical factors associated with poor self‐rated oral health in adolescents.Methods:  A cross‐sectional survey was carried out in two cities of the Distrito Federal, Brazil. Data were collected by clinical examinations and by self‐administered questionnaires from 1302 adolescents aged 14‐ 15 years in 39 schools. Data analysis was carried out using a Poisson regression model taking into account the cluster sample.Results:  Adjusting for social, psychosocial and clinical factors, results showed that poor self‐rated oral health was significantly associated (P < 0.001) with sex (males) [prevalence ratio (PR) = 0.8, 95% confidence interval (95% CI): 0.7–0.9]; low social class (PR =1.4, 95% CI: 1.2–1.6); poor self‐rated general health (PR = 2.6, 95% CI: 2.3–3.1); mouth appearance (PR = 1.9, 95% CI: 1.6–2.2) and with presence of untreated dental decay (PR = 1.4, 95% CI: 1.3–1.6).Conclusions:  The single question on self‐rated oral health appears to be a simple and easy way to collect dental health information in adolescents. Assessment and understanding of self‐rated oral health should take into account social, psychosocial and oral factors.
Melatonin, Cortisol, Prolactin, and Calcitonin Secretion in Primary Hyperparathyroidism Before After Surgery
Authors: Brismar K. , Werner S. , Bucht E. , Wetterberg L. 
Published: February 2007

The aim of the present study was to determine the diurnal secretion of melatonin, cortisol, prolactin, calcitonin during chronic parathyroid hormone‐dependent hypercalcemia. Eight women, aged 40–76 years, with primary hyperparathyroidism (PHPT) were studied before after surgical removal of a parathyroid adenoma. The hormone concentrations in blood were determined at 08, 12, 16, 22, 02, 04, 06 h. Concomitantly, the excretion of melatonin cortisol in urine between 07–19 h 19–07 h, the clearance of calcium creatinine were measured.Nyctohemeral serum prolactin calcitonin were unaffected by moderate parathyroid hormone‐dependent hypercalcemia. In contrast, serum cortisol melatonin were significantly higher during active disease than after surgical cure. Mean 24‐h variation of serum cortisol was 349 ± 34 nmol/liter vs. 223 ± 17 nmol/liter mean serum melatonin was 0.13 ± 0.04 nmol/liter vs. 0.06 ± 0.02 nmol/liter. Endogenous creatinine clearance was similar before after surgery, while the clearance of melatonin cortisol significantly increased after surgery, indicating an increased tubular reabsorption of both hormones during active disease. Fasting morning glucose concentrations were also significantly decreased after successful surgery, 6.1 ± 0.6 vs. 5.2 ± 0.5 mmol/liter. It is suggested that the relative hypercortisolism may be the cause of the glucose intolerance in primary hyperparathyroidism.Three to 4 months after surgical cure the serum melatonin levels were significantly lower than those seen in age‐matched controls, indicating a melatonin insufficiency in patients successfully treated for PHPT. The meaning of this finding is not yet understood but might be of importance in the development of primary hyperparathyroidism.
Quantitative Cytological Analysis of Functional Changes in Adrenomedullary Chromaffin Cells in Normal, Sham‐Operated, and Pinealectomized Rats in Relation to Time‐of‐day: II. Nuclear‐Cytoplasmic Ratio, Nuclear Size, and Pars Granulosa of Nucleolus
Authors: Kachi T. , Banerji T. K. , Quay W. B. 
Published: February 2007

Adrenaline(A)‐ and noradrenaline(N)‐cells in the adrenal medulla of nonoperated (NO), sham‐operated (SO), and pinealectomized (PX) male rats (n = 125) were investigated by quantitative electron and light microscopy. Animals were killed at eight time points during a standardized 24‐h, light‐dark (12:12) cycle 14 days after surgery. Nuclear‐cytoplasmic (N/P) ratios, diameters of nuclei, and the frequency of nucleoli showing a large amount of pars granulosa (granulated nucleoli), were the primary characteristics studied.Major findings include the following: 1) The frequency of low N/P ratios over a 24‐h period tended to be higher in PX animals than in controls in A‐cells, as shown in large cell profiles (P < 0.02); but such a tendency was not apparent in N‐cells. Daily mean nuclear diameters were similar among the three experimental groups. 2) The 24‐h changing pattern of phase relations in the frequency of low N/P ratio and nuclear size differed between A‐ and N‐cells in NO and SO but not in PX animals. 3) The frequency of granulated nucleoli in A‐cells was much higher in PX animals than in NO and SO animals throughout a 24‐h period (P < 0.018), especially from the late light to early dark phase (P < 0.003), and higher in A‐cells than in N‐cells generally (P < 0.0009). Pinealectomy thus caused increases in the cytoplasm and in the pars granulosa of the nucleolus in many A‐cells; changes in N‐cells were less apparent. This suggest a disturbed balance and coordination between A‐ and N‐cell systems of adrenal medulla following pinealectomy.
Melatonin Inhibits Mitotic Activity of Adrenocortical Cells In Vivo and in Organ Culture
Authors: Sewerynek Ewa , Lewiński Andrzej 
Published: February 2007

The goal of this study was to examine the effects of melatonin, as well as those of melatonin and corticotropin (1–24 adrenocorticotropic hormone (ACTH); Synac‐then Depot) administered together, on the mitotic activity of adrenocortical cells in male and female mice. Melatonin was given subcutaneously once daily, in late‐afternoon injections (between 16: 00 and 18: 00) in doses of 1 μg, 10 μg, and 100 μg, and ACTH in a dose of 0. 1 mg (10 U) daily for 10 days. Additionally, the highest dose of melatonin (100 μg daily) was administered together with ACTH. The metaphase‐arrest technique using colchicine as a stathmokinetic agent was employed in the study. Melatonin, in all the examined doses, significantly decreased mean mitotic activity rate (MMAR) of the adrenal cortex in both male and female mice. Moreover, in a dose of 100 μg, melatonin suppressed the mitogenic effect of ACTH on the adrenal cortex.Furthermore, the present study investigated the effects of melatonin (5 × 10−7M), N‐acetylserotonin (NAC‐5HT) (5 × 10−7M), and ACTH (250 mU/ml or 1,000 mU/ml) alone as well as the effect of ACTH (250 mU/ml) applied jointly with melatonin on the mitotic activity of adrenocortical cells in rat adrenal explants incubated in vitro. Both pineal indoleamines (melatonin and NAc‐5HT) significantly decreased the MMARs of adrenocortical cells. Corticotropin, as well as ACTH and melatonin applied together, also reduced the MMAR of adrenocortical cells.The present data suggest that melatonin may be directly involved in the inhibitory control of adrenocortical cell proliferation.
Influence of pineal indoleamines on the mitotic activity of gastric and colonic mucosa epithelial cells in the rat: Interaction with omeprazole
Authors: Lewiński A. , Rybicka I. , Wajs E. , Szkudliński M. , Pawlikowski M. 
Published: February 2007

Lewinski A, Rybicka I, Wajs E, Szkudlinski M, Pawlikowski M. Influence of pineal indoleamines on the mitotic activity of gastric and colonic mucosa epithelial cells in the rat: Interaction with omeprazole. J Pineal Res 1991:10:104‐108.Abstract:We have investigated the effects of melatonin (Mel) and N‐acetylserotonin (NAc‐5HT) on the mitotic activity of gastric and colonic mucosa in adult male rats under basal conditions and after an administration of omeprazole (OM) (H+, K+‐ATPase inhibitor). The metaphase‐arrest technique was applied in the study. Additionally, serum gastrin levels were measured by RIA method in the OM‐treated group and in respective polyethyleneglycol (PEG)‐administered controls. We have found that: 1) OM‐treatment increased serum gastrin levels in rats; 2) OM enhanced the mitotic activity of the colonic mucosa cells, although, unexpectedly, it did not exert such an effect on the gastric mucosa cells; 3) Mel suppressed the OM‐induced increase of the colonic epithelium cell proliferation, while NAc‐5HT failed to reveal that action: 4) NAc‐5HT decreased the proliferation of gastric mucosa epithelial cells. The value of the mean mitotic activity rate (MMAR) of gastric mucosa after Mel‐treatment also decreased, but that change was not statistically significant. The obtained data are in compliance with previous results from our laboratory concerning the inhibitory effect of pineal indoleamines on the jejunal epithelium mitotic activity. The stimulatory effect of OM on the proliferation of colonic epithelium is probably mediated by OM‐induced hypergastrinaemia. The possibility of Mel interaction with intestinal gastrin receptors (a structural similarity occurs between Mel and benzotript, a specific gastrin receptor antagonist), as well as of the opposite effects of Mel and gastrin on intracellular cAMP content in the gut, are considered in the discussion of results.
Nor epinephrine induces Ca2+ release from intracellular stores in rat pinealocytes
Authors: Sáez Juan C. , Moreno Alonso P. , Spray David C. 
Published: February 2007

Sáez JC, Moreno AP, Spray DC. Nor epinephrine induces Ca 2+ release from intracellular stores in rat pinealocytes. J. Pineal Res. 1994: 16: 57–64.AbstractIn rat pinealocytes, an increase in intracellular Ca2+ concentration ([Ca2+]i) due to Ca2+ influx in response to nor epinephrine (NE) is a well recognized event involved in regulating several metabolic functions. Since NE also stimulates the metabolism of phosphatidyl inositols in rat pineal gland, it is conceivable that Ca2+ release from intracellular stores also contributes to the NE‐induced increase in [Ca2+]i. In this communication, we report that in rat pinealocytes loaded with fura‐2, a Ca2+ indicator, NE induced a transient increase in [Ca2+]i that preceded the known Ca2+ influx. This novel [Ca2+]i response to NE was detected in pinealocytes bathed with Ca2+‐free saline and prevented by TMB‐8, a blocker of Ca2+ release from intracellular stores, supporting the notion that the transient NE‐induced Ca2+ response was due to Ca2+ release from intracellular stores. In addition, after an extended exposure to NE a new addition of this neurotransmitter did not elicit the phasic Ca2+ response, and application of increasing amounts of NE induced a Ca2+ response that was progressively smaller, suggesting desensitization. Thus, NE is proposed to increase [Ca2+]i in rat pinealocytes by two mechanisms: (1) phasic release from intracellular stores and (2) tonic influx through a mechanism activated by larger applications of NE than required to evoke the phasic release.
Impact of light pulses on 6‐sulphatoxymelatonin rhythms in rats
Authors: Away David J. Ken , Rowe Shawn A. 
Published: February 2007

Kennaway DJ, Rowe SA. Impact of light pulses on 6‐sulphatoxymelatonin rhythms in rats. J. Pineal Res. 1994: 16: 65–72.AbstractThe acute and residual entraining effects of a 15 min pulse of light on rat pineal function in individual animals were investigated using the excretion rate of the melatonin metabolite, 6‐sulphatoxymelatonin, as an index of melatonin production. In animals maintained in a 12‐hr L: 12‐hr D photoperiod (lights off 1800), 15 min light exposure at 2000 had no significant effect on the metabolite rhythm. Light pulses at 2200 (i. e., after the onset of excretion) decreased the melatonin metabolite excretion rate for 3 hr, after which the excretion rate increased to normal. In contrast, pulses at 2400 and 0200 suppressed 6‐sulphatoxymelatonin for the rest of the night such that total excretion was 58 ± 8% and 66 ± 6% of the amount excreted on the night before the pulse. A light pulse at 0400 had no significant effect on the 6‐sulphatoxymelatonin excretion when compared with the first night collection. When the 6‐sulphatoxymelatonin rhythm was assessed on the night following light pulses at 2000 and 0400, the onset of metabolite excretion was unaffected (0.2 ± 0.75‐hr advance and 0.75 ± 0.15‐hr delay, respectively). In contrast, pulses at 2200, 2400, and 0200 resulted in significant delays in the onset of 2. 4 ± 0.2‐hr, 1.5 ± 0. 1‐hr, and 2.1 ± 0.3‐hr, respectively (P < 0.05). The offset of metabolite excretion was not significantly affected by a prior light pulse, except in animals receiving light treatment at 0400 when the offset was advanced by 1.5 ± 0.3 hr. In an associated experiment, the effect of constant darkness during the day after a 2200 light pulse was compared with our standard condition of light exposure from 0900 to 1800. The phase delay provoked by the light pulse was similar in both conditions (2.9 ± 0.4 hr and 2.2 ± 0.2 hr delays, respectively; P > 0.05). These results confirm the differential responsiveness of the pineal gland to light pulses during the night, both in terms of the acute suppression of melatonin production and the subsequent entraining effect of the melatonin rhythm, which had previously been assessed indirectly by serration‐N‐acetyltransferase (NAT) determinations.