bluuebunny/crossref_metadata_2025 huggingface dataset:
Multifrequency Impedance in the Assessment of Body Water Losses during Dialysis
Authors: De Lorenzo Antonino , Deurenberg Paul , Andreoli Angela , Sasso Guido F. , Palestini Massimo , Docimo Raffaella
Published: November 2008

Multifrequency bioelectrical impedance was used to predict changes in body water compartments during renal dialysis. Weight loss during dialysis was assumed to be water loss. Predicted total body water (TBW) from impedance after dialysis did not differ significantly from TBW determined by deuterium oxide dilution. However, the predicted change in TBW from bioelectrical impedance largely exceeded the observed weight (water) loss. The predicted change in extracellular water was slightly but significantly lower compared to the observed weight loss. The ratio of impedance at 1-100 kHz increased in all subjects during dialysis, and may be a simple tool to assess body water distribution.
Characterization and Control of Expression of Cell Surface Alkaline Phosphodiesterase I Activity in Rat Mesangial Glomerular Cells
Authors: Stefanovic Vladisav , Vlahovic Predrag , Ardaillou Raymond
Published: November 2008

Membrane-bound nucleotidases and phosphodiesterases are critical regulators of extracellular nucleic acid processing. We previously demonstrated that mesangial cell 5’-nucleotidase was an ectoenzyme, the expression of which was stimulated by macrophage-secreted products. We show in the present study that rat mesangial cell alkaline phosphodiesterase I is also an ectoenzyme characterized by a Km value of 0.41 mM and a Vmax of 20.8 nmol min-1 mg-1. Treatment of mesangial cells by dexamethasone increased alkaline phosphodiesterase I activity in a dose- and time-dependent manner. Maximal increase (×1.5) occurred after treatment with 1 µM dexamethasone for 5 days. Cycloheximide and RU 38486, a glucocorticoid receptor antagonist, suppressed the dexamethasone-induced increase in alkaline phosphodiesterase I activity. 5’-Nucleotidase activity was not modified by dexamethasone under similar conditions of study. In contrast with 5’-nucleotidase, alkaline phosphodiesterase I expression remained unchanged in the presence of macro-phage-conditioned medium or during cocultures of mesangial cells with macrophages. Interleukin-1, tumor necrosis factor, cyclic adenosine monophosphate and adenosine analogues also activated 5’-nucleotidase whereas they were inactive on alkaline phosphodiesterase I. These results suggest that extracellular DNA trapped in the mesangial area of the glomerular capillaries may be processed in part at the cell surface by alkaline phosphodiesterase 1 and that such an event may be regulated by glucocor-ticoids. They also show that alkaline phosphodiesterase I and 5’-nucleotidase obey a different regulation.
Dibutyryl Cyclic Adenosine Monophosphate Stimulates the Sodium Pump in Rabbit Renal Cortical Tubules
Authors: Beck Jon S. , Marsolais Mireille , Nöel Josette , Breton Sylvie , Laprade Raynald
Published: November 2008

The elevation in oxygen consumption (QO2) observed following addition of the sodium ionophore nystatin in suspensions of rabbit renal proximal tubules was significantly increased by 1 mM dibutyryl cyclic adenosine monophosphate (db-cAMP). The QO2 after subsequent addition of strophanthidin to block the sodium pump was unnaffected by db-cAMP. However, 10 µM forskolin in the presence of 100 µM IBMX had no significant effect on the QO2 observed following addition of either nystatin or strophanthidin. Nevertheless, we can conclude that db-cAMP does stimulate the sodium pump activity independently of sodium transport mechanisms in the rabbit renal proximal tubule.
Corticosterone Increases Na+-K+-ATPase Activity in Rat Cortical Collecting Ducts with Inhibition of 11β-Hydroxysteroid Dehydrogenase
Authors: Tsuganezawa Hirohiko , Hayashi Matsuhiko , Fujii Yoshiaki , Yamaji Yasuyoshi , Iyori Masahiro , Saruta Takao
Published: November 2008

To examine a physiological role of 11β-hydroxysteroid dehydrogenase (11OHSD) in the aldosterone target tissues, we measured Na+-K+-ATPase activity in the cortical collecting ducts (CCD) from adrenalectomized rats, which were treated with a physiological dose of corticosterone and/or carbenoxolone (an inhibitor of 11OHSD). The Na+-K+-ATPase activity in adrenalectomized rats was not significantly changed by either corticosterone alone or carbenoxolone alone, whereas its activity showed a significant increase only in the rats that received both corticosterone and carbenoxolone. In these rats, the plasma concentration of corticosterone was within the physiological range (10-6M) and the plasma carbenoxolone concentration was about 10-7M. Furthermore, the direct effect of carbenoxolone was examined in the microdissected CCD because it has been reported that carbenoxolone per se had an affinity for the aldosterone receptor. Na+K+-ATPase activity in the microdissected CCD was increased in a dose-dependent manner after a 3-hour incubation with carbenoxolone, and this effect was completely inhibited by canrenoic acid (an aldosterone antagonist). However, the minimal carbenoxolone concentration exerting a stimulatory effect was 10-6M, which is about 10 times higher than the plasma concentration of carbenoxolone in the in vivo treated rats. These results indicate that an inhibition of 11OHSD but not a direct action of carbenoxolone induces an increase in Na+-K+-ATPase activity, which is a well-known aldosterone effect in the CCD.
Cathepsin B and L in Isolated Proximal Tubular Segments during Acute and Chronic Proteinuria
Authors: Eisenberger Ute , Fels Lüder M. , Olbricht Christoph J. , Stolte Hilmar
Published: November 2008

Acute and chronic proteinuria were studied in rats, using lysosomal cathepsin B and L as marker enzymes for tubular protein degradation. The activity of cathepsin B and L has been determined in microdissected segments S1, S2 and S3 of the proximal tubule by an ultramicroassay. Z-Phenylalanyl-arginine-7-amido-4-methylcoumarin served as a substrate. In normoproteinuric Sprague-Dawley rats, induction of acute unselective glomerular proteinuria with Adriamycin (5 mg/kg body weight) revealed a moderate activity increase of cathepsin B and L in the S2 segment, reaching 12.6 ± 5.6 versus 8.6 ± 4.2 pmol·mm-1·min-1 in controls. In contrast, Munich Wistar Frömter (MWF) rats, that are characterized by a genetically determined, chronically elevated glomerular protein excretion, showed a very high activity of cathepsin selectively in S2 of 25.0+12.1 pmol· mm-1 min-1. Acute proteinuria induced by Adriamycin in chronic proteinuric MWF rats could increase cathepsin activity in the S3 segment only, showing 12.0 ± 8.3 versus 6.8 ± 4.0 pmol-mm-1 min-1 in MWF control rats. In conclusion, chronically increased protein filtration changes the functional reserve capacity of the proximal tubule. While acutely induced glomerular proteinuria in normoproteinuric rats stimulates lysosomal proteolytic activity mainly in S2 segment, chronic proteinuric MWF rats may display already a maximally stimulated cathepsin activity in this segment probably due to long-term increased tubular protein load. In case of acute elevation of chronic proteinuria, the consecutive S3 segment shows increased lysosomal function for protein conservation.
Effects of Ipsilateral Denervation and Contralateral Ureteral Obstruction on Tubuloglomerular Feedback
Authors: Wilke W. Lee , Persson A. Erik G.
Published: November 2008

The effects of acute ipsilateral denervation (AID) and contralateral ureteral obstruction on tubuloglomerular feedback (TGF) was studied by micropuncture in rats. Denervation alone was associated with an increase in the TGF turning point, the tubular flow rate required for a half-maximal TGF response, but other TGF characteristics were not affected. Contralateral ureteral obstruction alone was also associated with an increased turning point, but contralateral obstruction had no effect on turning point, when AID was done prior to the obstruction. We conclude that renal nerves have a tonic modulating effect on TGF in anesthetized rats, and that renorenal reflexes are involved in the TGF resetting associated with acute contralateral ureteral obstruction.
Ifosfamide and Mesna: Effects on the Na/H Exchanger Activity in Renal Epithelial Cells in Culture (LLC-PK1)
Authors: Mohrmann Matthias , Küpper Nicola , Schönfeld Barbara , Brandis Matthias
Published: November 2008

Ifosfamide (IF) is an alkylating cytostatic with urotoxic and tubulotoxic side effects which may result in the development of Fanconi syndrome in children. While the urotoxicity of IF is effectively prevented by the uroprotective thiol compound sodium-2-mercaptoethanesulfonate (Mesna), tubulotoxicity of IF may occur even in the presence of Mesna and in the absence of any signs of urotoxicity. Using the renal tubular cell line LLC-PK1, we investigated whether there is a protective effect of Mesna or of its major dimeric metabolite Dimesna against metabolites of IF with respect to the Na/H exchanger activity. We tested the major IF metabolites 4-hydroperoxy-IF (4-OOH-IF), chloroacetaldehydc (CAA), and acrolein. All metabolites significantly inhibit the Na/H exchanger activity. Half-maximal inhibition of transport occurs at concentrations of 120 µmol/l (4-OOH-IF), 80 (CAA), and 60 µmol/l (acrolein) after 2 h of incubation. The onset of the inhibitory effect of all three metabolites is rapid. Complete inhibition of Na/H exchange by acrolein and CAA is present after a 6-hour exposure to 100 µmol/l of the respective metabolite, while 100 µmol/l 4-OOH-IF causes only 50% inhibition after 24 h of incubation. Dimesna, which the proximal tubular cell has to reduce to Mesna at the expense of intracellular glutathione before it exerts a uroprotective effect, has no protective effect in LLC-PK1 cells. Dimesna (0.3 mmol/l) displaces the dose-response curve for acrolein to the left, indicating an increased toxicity of the combination of acrolein plus Dimesna. Mesna (0.3 mmol/l) has a complete protective effect with respect to acrolein and CAA, while the protective effect versus 100 µmol/l of 4-OOH-IF is incomplete. We conclude that the function of the Na/H exchanger in LLC-PK1 cells is altered by metabolites of IF. The incomplete protection against the toxic effect of 4-OOH-IF by Mesna may explain the pathomechanism by which IF causes tubulotoxicity in the absence of urotoxicity.
Role of Renal Nerves in Volume Expansion in Chronic Hypoxic Rats
Authors: Chien Chiang-Ting , Fu Tsu-Ching , Wu Ming-Shieu , Chen Chau-Fong
Published: November 2008

This work was designed to study the significance of the renal nerves in chronic hypoxic (high-altitude; HA) rats after saline loading. Female Wistar rats (200-290 g) under sodium pentobarbital (40 mg/kg i.p.) anesthesia were used in these experiments. Hypoxia was induced by placing the rats in an altitude chamber (5,500 m) for 4 weeks. Both the renal efferent nervous activity (RENA) and the renal afferent nervous activity (RANA) were recorded simultaneously throughout the experimental period. It was found that the responses of RENA and RANA to an intravenous saline infusion (10 ml, 10 min) were significantly different between the sea level (SL) control and HA rats. In SL rats, a depression of RENA was found; the depressed RENA had not recovered 80 min after cessation of the saline infusion. In HA rats, an initially depressed RENA was also found; however, it returned to the control level within 10 min following the cessation of saline infusion. RANA enhanced twice a few minutes after saline loading in SL rats; however, the changes of RANA in HA rats were not significant. In both groups of rats, whether renally denervated or intact, the amount of excretory urine and sodium after saline loading was unchanged. The renal norepinephrine levels were also measured by a high-pressure liquid chromatography system in both groups of rats, and it was found that the renal norepinephrine content of the HA rats was significantly higher than in the SL rats. From these results, it was concluded that the renal nervous response to volume expansion is different in anesthetized chronic hypoxic rats; however, in spite of the impaired renal nervous activity, other regulatory systems still work successfully to maintain the renal function at a steady state.
P2U-Purinergic Receptor Activation Mediates Inhibition of cAMP Accumulation in Cultured Renal Mesangial Cells
Authors: Schulze-Lohoff Eckhard , Bitzer Markus , Ogilvie Adaling , Sterzel Ralf Bernd
Published: November 2008

Extracellular ATP has been reported to exert mitogenic and contractile effects on cultured renal mesangial cells (MCs). Since it is possible that these actions involve changes in the cAMP second messenger system, we examined the effect of extracellular nucleotides on the accumulation of cAMP in rat MCs. ATP, UTP and adenosine 5’-0-(3-thio)triphosphate (ATPΓS) (100 µM) had no significant effects on baseline cAMP levels, but inhibited forskolin-stimulated accumulation of cAMP by 21-75% in the presence of the phosphodiesterase inhibitor 3-isobutyl-l-methylxanthine (IBMX). Maximal inhibitory effects were observed at 100 µM of ATPΓS with a threshold dose of 1 µM. ATPΓS, ATP and UTP were the most potent inhibitors indicating stimulation of the P2u receptor. The P2x agonists adenosine 5’-(Α,Β-methylene) triphosphate and adenosine 5’-(Β,Γ-methylene) triphosphate, and the P2y agonist 2-methylthio-ATP did not affect cAMP accumulation. Treatment with the P2 receptor antagonist suramin (200 µM) reduced the inhibition by 58%. The inhibitory effects of the nucleotides were significantly attenuated by preincubation with pertussis toxin (10-100 ng/ml). Inhibition of phospholipase C and protein kinase C did not prevent the inhibitory effect of the nucleotides. Inhibitors of forskolin-stimulated cAMP accumulation had different effects on DNA synthesis in cultured MCs as measured by 3H-thymidine uptake at 48 h: ATP, ATPΓS and the inhibitor of adenylyl cyclase, SQ 22536, stimulated DNA synthesis in MCs, while UTP showed no significant mitogenic effect. Agents which increased baseline levels of intracellular cAMP (forskolin, IBMX, dibutyryl-cAMP) significantly diminished DNA synthesis in MCs. The results indicate that the P2u-purinergic receptor mediates inhibition of forskolin-induced cAMP accumulation which is likely due to inhibition of adenylyl cyclase. This effect appears to be partially mediated by PTX-sensitive G proteins. While the increase in cAMP accumulation is anti-mitogenic, inhibition of cAMP accumulation by P2u receptors is not correlated with MC growth control. Thus, additional mechanisms other than inhibition of cAMP accumulation by P2u receptors are likely to be involved in the mitogenesis of extracellular ATP.
Pyrene Fluorescence: A Potential Tool for Estimation of Short-Range Lateral Mobility in Membranes of Living Renal Epithelial Cells
Authors: Ando Yasuhiro , Asano Yasushi , Le Grimellec Christian
Published: November 2008

The excimer-to-monomer (E/M) fluorescence ratio of pyrene (p) and its derivatives has been found to correlate with membrane fluidity. We explored the possible use of this method in living renal epithelial cells. In Modin-Darby canine kidney cells, successful fluorescent labeling was obtained with p-cholesterol, p-trimethylammonium (TMA), p-sulfonamidethyl-TMA, p-buty-rate, p-propanoate or p-dodecanoate. Among them, the labeling with p-cholesterol was most stable. The whole cell cholesterol content did not significantly increase after loading p-cholesterol and the probe incorporated was not degraded. The E/M ratio changed reproducibly and significantly by temperature change, a standard method to alter membrane fluidity. Thus, the E/M ratio of p-cholesterol fluorescence is suggested to be a potential parameter of membrane fluidity in living renal epithelial cells and might be useful in investigating the relationship between the physical state of the membrane and epithelial function.
Effect of rh-GMCSF and rh-GCSF on Oxygen Free Radical Production by Human Neutrophils and Blood Monocyte-Derived Human Macrophages
Authors: Al-Shammary F.J. , Al-Zamel Faten , El-Shewemi S. , Soliman R.
Published: November 2008

The in vitro effect of recombinant human granulocyte-macrophage colony stimulating factor (rh-GMCSF) and recombinant human granulocyte colony stimulating factor (rh-GCSF) on oxygen free radical (OFR) generation by human neutrophils and blood monocytes derived human macrophages stimulated with phorbol myristate acetate was investigated and compared. The production of OFR by neutrophils and macrophages was time dependent, and the maximum release of OFR by neutrophils and macrophages was measured 90 and 180 min after stimulation with phorbol myristate acetate, respectively. The priming effects or rh-GMCSF and rh-GCSF on OFR production by human neutrophils and macrophages was dose dependent. The maximum generation of OFR by neutrophils occurred when primed with 1,000 U/ml of rh-GMCSF and reached 2.383+0.191 nmol/l05 neutrophils/90 min as compared with 1.072 ± 0.113 nmol/l05 neutrophils/90 min in the unprimed controls. This represents a 122.20% increase in OFR generation (p < 0.001). However, the percentage of maximum increase in OFR production was 57.84 when neutrophils were primed with a concentration of 5,000 U of rh-GCSF/ml. In 72-hour-old human macrophages, much higher levels of OFR production as compared with neutrophils were measured following stimulation with phorbol myristate acetate. The maximum generation of OFR was measured in macrophages primed for 45 min with 500 U/ ml of rh-GMCSF. These cells produced 8.960 ± 2.075 nmol/5×104 macrophage/180 min as compared with 4.563+1.773 nmol/5×104 unprimed macrophages/180 min (p < 0.001). In macrophages primed with rh-GCSF, however, the maximum OFR production was induced by a dose of 5,000 U/ml and reached 6.902+1.463 nmol/5× 104 macrophages/180 min as compared with 4.563 ± 1.773 nmol/5×104 macrophages/180 min in the unprimed controls (p < 0.05). In conclusion, the priming effect of rh-GMCSF on OFR generation by human macrophages and neutrophils was more potent than that of rh-GCSF, both in the extent of augmentation and in the dose required to produce maximum OFR generation.
Ultrapure Polymerized Bovine Hemoglobin Improves Structural and Functional Integrity of the Isolated Perfused Rat Kidney
Authors: Willinger Christian C. , Schramek Herbert , Pfaller Kristian , Joannidis Michael , Deetjen Peter , Pfaller Walter
Published: November 2008

Since it became evident that organ dysfunctions after acute hemolysis are not induced by hemoglobin per se, but by stroma-contaminated hemoglobin, solutions of ultrapure stroma-free hemoglobins were regarded to be possible substitutes for blood in transfusion medicine. We tested one of the recently developed modified bovine hemoglobins (Ultrapure polymerized bovine hemoglobin 1; UPPBHb1) in the isolated perfused rat kidney (IPRK) model, using a recirculating system. Control kidneys were perfused with a substrate-enriched Ringer solution containing hydroxyethyl starch (HES) to produce isoncotic conditions. In the experimental group HES was substituted in part by UPPBHb1 (34 g/l). For determination of functional parameters, the kidneys were perfused for 180 min. A separate set of kidneys of both groups was perfusion fixed after 80 min of perfusion which is the period of optimal function. Light and electron microscopic analysis revealed major alterations only for the outer medulla of HES kidneys. Only these suffered from a considerable extent of proximal tubular S3 damage, exhibiting condensed tubular epithelia. In the inner stripe of the outer medulla, which is the zone of greatest sensitivity to damage in the isolated perfused kidney, severe hydropic degeneration, cell detachment, and necrotic destruction of the medullary thick ascending limb were seen in the HES-perfused group, too. In the UPPBHb1 group, the medullary thick ascending limb was well preserved, and S3 showed only a minor degree of damage. UPPBHB1 kidneys were further characterized by the occurrence of intracapillary and interstitial precipitates of UPPBHb1 in inner stripe of the outer medulla and inner medulla. The glomerular filtration rate was significantly higher in UPPBHb1-perfused kidneys (870 ± 80 vs. 630 ± 55 µl/min/g kidney weight for HES). Absolute reabsorption of sodium paralleled the behavior of the glomerular filtration rate. The values for renal perfusate flow and urinary flow rate did not differ significantly between both groups. Renal autoregulation was better preserved in UPPBHb1-perfused kidneys (74 ± 6% of full autoregulatory response) than in HES-perfused controls (42 ± 4%). Our results suggest that perfusion of isolated rat kidneys with UPPBHb1 improves kidney function and morphology, providing better oxygenation than in control kidneys. UPPBHb1 does not exert additional nephrotoxic effects on the IPRK that will exceed the noxious potential of the method itself. Thus, it must be concluded that UPPBHb1 may be an oxyphoretic blood substitute with nephroprotective characteristics when compared with nonoxyphoretic substitutes. At least, UPPBHb1 seems to be a promising candidate as oxyphoretic additive to perfusates for the IPRK model.
Nodular Morphea
Authors: Kauer F. , Simon J.C. , Sticherling M.
Published: November 2008

Scleroderma may present as being strictly limited to the skin, as in morphea, or within a multiorgan disease, as in systemic sclerosis. Accordingly, cutaneous manifestations vary clinically. In nodular or keloidal scleroderma, patients develop lesions that are clinically indistinguishable from a keloid; however, the histopathological findings are more variable. We describe a 16-year-old girl with morpheic lesions for 3–4 years and additional development of keloidal nodules within these lesions. The histological examination revealed a hypertrophic scar besides morphea.
Protection of Minority Communities in Kosovo: Legally Ahead of European Standards—Practically Still a Long Way to Go
Authors: Lantschner Emma
Published: November 2008

In this article, the author analyzes the legislative framework for the protection of minority communities in Kosovo, as it has developed from the periods before and after the declaration of independence, and its implementation in practice. She focuses in her study on four major issues: non-discrimination, education for minority communities, the use of languages, and effective participation, including issues of decentralization. The author comes to the following conclusions. First, in each field, quite advanced laws exist that in many respects are perfectly in line or even way ahead of the standards applied in other European countries. But implementation has been lacking so far. Second, on the institutional side, the author draws attention to the multitude of national (and international) actors dealing with minority issues, risking thereby an uncoordinated approach to minority issues and a failure to mainstream such matters. And, third, the reluctance of the Serb community to cooperate with the Kosovar authorities has further been identified as highly problematic, because true reconciliation requires a willingness to participate in interethnic cooperation.
Understanding the Effects of Nonstraightforward Communication in Organizational Discourse
Authors: Kline Susan L. , Simunich Bethany , Weber Heath
Published: November 2008

Two experiments ( n = 605) utilize equivocal communication theory to understand the effects of nonstraightforward communication in organizational discourse, specifically in initial spokesperson responses to organizational crises. In a first experiment, young adults rated equivocal and nonequivocal spokesperson responses to corporate crisis situations that either contained or did not contain an avoidance-avoidance goal conflict. As predicted, equivocal messages were both viewed as appropriate messages to use and associated with two measures of corporate reputation in avoidance-avoidance situations. By contrast, nonequivocal messages were viewed as more appropriate to use and associated with corporate reputation in non—avoidance-avoidance situations. Experiment 2 essentially replicated these findings and showed that the effect of nonequivocal and equivocal messages on perceived corporate reputation is partially mediated by how well the messages are perceived to handle goal conflicts in crisis situations.
Multiple Maximum Exposure Rates in Computerized Adaptive Testing
Authors: Barrada Juan Ramón , Veldkamp Bernard P. , Olea Julio
Published: November 2008

Computerized adaptive testing is subject to security problems, as the item bank content remains operative over long periods and administration time is flexible for examinees. Spreading the content of a part of the item bank could lead to an overestimation of the examinees' trait level. The most common way of reducing this risk is to impose a maximum exposure rate (rmax) that no item should exceed. Several methods have been proposed with this aim. All of these methods establish a single value of rmax throughout the test. This study presents a new method, the multiple-rmax method, that defines as many values of rmax as the number of items presented in the test. In this way, it is possible to impose a high degree of randomness in item selection at the beginning of the test, leaving the administration of items with the best psychometric properties to the moment when the trait level estimation is most accurate. The implementation of the multiple-r max method is described and is tested in simulated item banks and in an operative bank. Compared with a single maximum exposure method, the new method has a more balanced usage of the item bank and delays the possible distortion of trait estimation due to security problems, with either no or only slight decrements of measurement accuracy.
XRD and Thermal Characteristic Studies of Conducting Polymers
Authors: Hota P.R. , Parida R.K. , Das S.C.
Published: November 2008

Polyaniline (PANI) and substituted polyaniline (SPANI) have been synthesized. Their structure has been confirmed from UV-Vis, Fourier-Transform Infra Red (FTIR), and 1H Nuclear Magnetic Resonance (NMR) spectral studies. Their physicochemical properties are also studied. The electrical dc conductivity of the reported polymers are also measured by a four-probe technique. A fully computerized Lotus package method has been applied for the thermogravimetric studies. The kinetics of degradation mechanism and energy of activation for each degradation have been reported. Thermogravimetric analysis of the polymers show 50% decomposition over a temperature range of 600°C. XRD results show the values of 2θ within the range of 25—27° confirming the best order polymer subchains and also their crystalline character.
Failure Analysis of Laminated Composite Plates with Two Parallel Pin-loaded Holes
Authors: Ataş Akin , Arslan Nurettin , Sen Faruk
Published: November 2008

The aim of this study is to research the failure loads and failure modes of laminated woven-glass—polyester composite plates with two parallel circular holes, which are subjected to traction forces by two rigid pins. The failure behavior of two parallel pin-loaded composite plates has been observed both experimentally and numerically with different geometries and fiber orientations. While the plate width to hole diameter ratio (W/D) was held constant; the distance from the free edge of the plate to hole diameter ratio (E/D) was changed from 1 to 5, and the distance between two parallel holes to hole diameter ratio (M/D) was varied from 2 to 5. Two different ply rientations were also investigated as [0°]8 and [0°2=60° 2/]s. In a numerical study, a three-dimensional finite element method (FEM) was used with the assistance of a LUSAS 13.6 finite element analysis program. Good agreement has been shown between experimental and numerical results.
Experimental Evaluation of Co-Infusion as a Viable Method for In-Mold Coating of Composite Components
Authors: Solomon Fouad A. , Okoli Okenwa I.
Published: November 2008

This work assessed the viability of co-infusing a thermoset resin and liquid coating formulations for the in-mold coating of composite components manufactured by the resin infusion between double tooling (RIDFT) process. Material trade studies conducted to resolve the compatibility issues of the separation layer and coating material were successful. The modifications of the RIDFT—IMC assembly succeeded in eliminating the risk of premature fiber wetting during coating material infusion. Experiments were conducted to determine the best manufacturing conditions for production of a viable RIDFT—IMC component. The results indicate that reducing the coating exposure to heat yielded in improved surface characteristics. Microstructural examination further confirmed that the coating did not infiltrate the fiber—resin interface.
Effect of Multi-walled Carbon Nanotubes on Mechanical Properties of Feldspar Filled Polypropylene Composites
Authors: Ansari M.N.M. , Ismail H. , Zein S.H.S.
Published: November 2008

In this study, the effect of multi-walled carbon nanotube (MWCNT) reinforcement on mechanical and morphological properties of MWCNT reinforced feldspar/polypropylene composites was investigated. The composites were compounded in a Polydrive Thermo Haake R600 internal mixer at 180°C and at 50 rpm of rotor speed. Polyethylene co-acrylic acid (PEAA) was used as a processing aid in this study. The structure and dimensions of the MWCNTs were characterized using a transmission electron microscope (TEM). The tensile strength, elongation at break, Young’s modulus, flexural strength, flexural modulus, and impact strength increased with the addition of 0.1 wt% of MWCNT. The morphology and degree of dispersion of the MWCNTs in the feldspar/PP composites at different MWCNT loading was investigated using scanning electron microscopy (SEM). Results indicate that MWCNTs are well distributed and dispersed in feldspar/PP composites particularly at low filler loading, i.e., 0.1 wt%.
Characterization of Mechanical Behavior of Metallic and Non-metallic Particulate Filled Epoxy Matrix Composites
Authors: Bhagyashekar M.S. , Rao R.M.V.G.K.
Published: November 2008

Studies were carried out on RT cure epoxy (LY556+HY951) composite system comprised of metallic and non-metallic fillers. The results of the studies carried out on composites with three distinctly different particulate fillers, representing ductile (Cu and Al), brittle (SiC), and soft (Gr) type of materials regarding the mechanical properties, showed that the tensile and flexural strength of the particulate composites degraded with filler loading, whereas the modulus (both tensile and flexural) of the composites increased with the filler loading for the range of filler contents considered (10—40 wt%). The compression strength of all the composites increased to a maximum up to a filler loading of 30% and then decreased beyond this value, with the SiC-Ep composites exhibiting the highest improvement in the compression strength.
Geometrical Correction to the Elastic Stiffness of Particulate Composites
Authors: Lim Teik-Cheng
Published: November 2008

A geometrical correction to previous models for the elastic modulus of particulate composites is proposed in this article in a closed-form analytical expression. By comparing the geometrically corrected models (which adopt spherical particulates) to previous models (which employ cubic particulates) a set of correction factors and functions are extracted. The correction factors modify the influence of filler volume fraction while the correction functions describe the effect of filler—matrix boundary shape to the overall composite modulus. With the aid of geometrical correction, the validity, or otherwise, of earlier models are discussed with reference to previous experimental data and are elucidated through their representative volume element’s assumed boundary conditions. These correction parameters allow the practitioner to easily incorporate geometrical correction to previously known models.
Curing Characteristics and Mechanical Properties of Hybrid Palm Ash/Silica/Natural Rubber Composites
Authors: Ismail H. , Haw F.S.
Published: November 2008

Hybrid palm ash/silica/natural rubber composites were prepared using a laboratory-sized two roll mill. The effects of partial replacement of palm ash by silica on curing characteristics, mechanical properties, and morphology of hybrid palm ash/silica/natural rubber composites were investigated. Compared to the control composite (30 phr of palm ash), increasing the silica in the weight ratio of silica/palm ash increases the scorch time and cure time, the maximum and minimum torques, and enhances the rubber—filler interaction, tensile strength, tensile modulus, and fatigue life. However the incorporation of palm ash also exhibits the beneficial effects by shorter curing time of hybrid palm ash/silica/natural rubber composites.
Constructions of Work Among Adolescents in Transition
Authors: Ferrari Lea , Nota Laura , Soresi Salvatore , Blustein David L. , Murphy Kerri A. , Kenna Alexandra C.
Published: November 2008

To analyze the conception of work and its relationship with the various indices of progress in career development, we administered a structured, open-ended questionnaire that explored beliefs about working among a sample of Italian high school students considering university options. Using both quantitative and qualitative methods, we found that the majority of students considered work as a means to an end; a smaller proportion of students viewed work as a source of psychological satisfaction. The quantitative analyses revealed that students who considered more than one dimension of work in their internal constructions tended to rely on more adaptive means of career decision making. The results are discussed in light of previous research and current perspectives in career development theory.
Sensitivity and specificity of the Modified Checklist for Autism in Toddlers and the Social Communication Questionnaire in preschoolers suspected of having pervasive developmental disorders
Authors: Snow Anne V. , Lecavalier Luc
Published: November 2008

This study assessed the psychometric properties of the Modified Checklist for Autism in Toddlers (M—CHAT) and the Social Communication Questionnaire (SCQ) in a sample of preschool children referred for possible pervasive developmental disorders (PDDs). The sample consisted of 82 children between the ages of 18 and 70 months (54 with a PDD diagnosis and 28 with non-PDD diagnoses). M—CHAT scores were analyzed for 56 children aged 18—48 months old and SCQ scores were analyzed for 65 children aged 30—70 months old. Optimal sensitivity and specificity were achieved using the cutoff score of any three items on the M—CHAT and lowering the cutoff score of the SCQ. The diagnostic agreement of both instruments was also compared in an overlapping subsample of 39 children aged 30—48 months. Overall, the M—CHAT and SCQ appear to more accurately classify children with PDDs who have lower intellectual and adaptive functioning.
Spontaneous imitation by children with autism during a repetitive musical play routine
Authors: Stephens Carolyn E.
Published: November 2008

Joint-attention-type intervention strategies have been identified as effective scaffolds for increasing social engagement in children with autism. Imitating children with autism within child-led social routines has increased children's attention and active participation in social interaction. The current study expands on this research by establishing a musical social milieu using repetitive imitation routines for four children with autism. Results were evaluated using an MPD across three behaviors and four children with an ABAB reversal for one child. Children increased spontaneous imitation of the researcher's models after being imitated with only social reinforcement for increased imitation. However, experimental control was weakened with carry-over effects for two children and failure to fully replicate results across participants and behaviors. The accumulation of evidence from varied studies, despite some mixed results, encourages further study into the effects of imitating children with autism to increase spontaneous social engagement.
Underreporting of external cause codes in the Finnish Hospital Discharge Register
Authors: Lunetta Philippe , Impinen Antti , Lounamaa Anne
Published: November 2008

Background: Hospital discharge data (HDD) represent one of the most valuable information sources for injury prevention and control. Objectives: To investigate external code of injury (E-code) underreporting in the Finnish National Hospital Discharge Register from 1 January 1987 to 31 December 2004. Material and methods: HDD for discharges with an injury as the main diagnosis were extracted from the FNHDR. The selection was made using codes for nature of injury (1987—1995, ICD-9; 1996—2004, ICD-10). The proportion of injury discharges with a missing E-code was examined by sex, age, hospital districts, type of hospital, duration of hospitalization, and nature of injury. Results: In 432,549 (23.1%) of the recorded 1,868,519 discharges, an E-code was missing. The proportion of the discharges with a missing E-code varied among the above variables. During the period 1987—2004, the overall E-code underreporting decreased from 18.0% to 12.8%. The introduction of the ICD-10 in 1996 was followed by a dramatic increase (up to 57.5% of all discharges) in E-code underreporting. Conclusions: More attention ought to be dedicated to teaching and periodic training on the use of E-codes. Educational activities should specifically target the medical doctors, who, in Finland, are responsible for assigning the E-codes.
Parents' and teachers' communication about HIV and sex in relation to the timing of sexual initiation among young adolescents in Tanzania
Authors: Kawai Kosuke , Kaaya Sylvia F. , Kajula Lusajo , Mbwambo Jessie , Kilonzo Gad P. , Fawzi Wafaie W.
Published: November 2008

Aims: Early sexual debut is associated with increased HIV risk among young adolescents in sub-Saharan Africa. Our study examines parents' and teachers' communication about sexual matters in relation to the timing of sexual initiation among students aged 12—14 years old in Dar es Salaam, Tanzania. Methods: Virgin primary school students were followed prospectively for 6 months to assess sexual initiation. Socio-demographic, psychosocial, and behavioural factors were assessed with a structured questionnaire. Univariate and multivariate logistic regression analyses were performed. Results: Of 2477 adolescents, 26.9% of students reported communicating about HIV and sex with parents and 35.6% communicated with teachers. Communication with teachers about HIV and sex was associated with delayed sexual initiation among adolescents after adjusting for potential confounding factors (OR=0.59, 95%CI=0.40—0.89, p=0.01). However, parental communication was not associated with the timing of sexual initiation. The perception that most peers are sexually active was a significant predictor of early sexual debut (test for linear trend, p=0.002). Students who do not live with a biological mother were marginally more likely to initiate sex compared to those who live with a biological mother (OR=1.39, 95%CI=0.97—1.99, p=0.08). Conclusions: Teachers can play an effective role in discussing HIV and sex with young adolescents. Our study highlights the necessity of responsible adults discussing sexual matters with young adolescents in sub-Saharan Africa. More research is required to better understand the role of parental communication about sexual matters and strategies for improving the quality of parental communication.
Hopelessness — novel facet of the metabolic syndrome in men
Authors: Valtonen Maarit , Laaksonen David E. , Tolmunen Tommi , Nyyssönen Kristiina , Viinamäki Heimo , Kauhanen Jussi , Niskanen Leo
Published: November 2008

Aims: Recent studies have shown that lack of hope is linked to cardiovascular morbidity and mortality. Little is known, however, about the relationship of hopelessness and the metabolic syndrome. The aim of this study is to examine the association of hopelessness and the metabolic syndrome. Methods: This cross-sectional study examines the relationship between hopelessness and the metabolic syndrome as defined by the National Cholesterol Education Program in a population-based cohort of 1743 non-diabetic men aged 42, 48, 54 and 60 years old at baseline (1984—89). Hopelessness was measured by one's expectations about the future and reaching goals. Results: In simple age-adjusted univariate analyses the prevalence of the metabolic syndrome, many of its components and other cardiovascular risk factors were more common in men with higher levels of hopelessness. In a logistic regression model adjusted for age, smoking, alcohol consumption, cardiovascular disease, adult socioeconomic status and physical activity, men in the highest third were 2.1 (95% CI 1.3—3.2) times more likely to have the metabolic syndrome than those in the lowest third. After further adjusting for body mass index and elevated depressive symptoms the respective figures were 1.9 (95% CI 1.2—3.1) and 2.1 (95% CI 1.4—3.4). Conclusions: Hopelessness was strongly associated with the metabolic syndrome in these middle-aged men, independent of other depressive symptoms and traditional cardiovascular risk factors. These findings suggest that hopelessness is very closely related to the metabolic syndrome. Therefore lifestyle management of the metabolic syndrome should also take into account patients' expectations more thoroughly than hitherto acknowledged.
Long-term fiscal implications of subsidizing in-vitro fertilization in Sweden: A lifetime tax perspective
Authors: Svensson Anders , Connolly Mark , Gallo Federico , Hägglund Leif
Published: November 2008

Aims: In Sweden approximately 3% of annual births are conceived using assisted reproductive technologies (ART). In light of increasing use of ART in Sweden we estimate the lifetime future tax revenues of a child conceived by in-vitro fertilization (IVF) to establish whether public subsidy of IVF represents sound fiscal policy. Methods: A modified generational accounting model was developed to calculate the net present value (NPV) of average investment costs required to achieve an IVF-conceived child. The model simulates direct lifetime financial interactions between the child and the Swedish government. Within the model we assume average direct financial transfers are made to the individual (eg, child allowance, education, health care, pension, etc). In return, the individual transfers resources to the government through taxation based on anticipated average earnings. The difference between direct transfers and gross taxes paid equals the net-tax contribution. Individual tax contributions were held constant in the model. Results: Based on average life-expectancy an individual born in 2005 will pay an undiscounted 32.5 million SEK in taxes to the Swedish government and receive 20.9 million SEK in direct financial transfers over their lifetime. When these figures are discounted and IVF costs are included in the analysis we obtain a lifetime NPV of 254,000 SEK with a break-even point at age 41 (the age of achieving a positive NPV) for an individual conceived through IVF. Conclusions: Based on results presented here we conclude that State-funded IVF in Sweden does not negatively impact the long run fiscal budget. Conversely, over an average lifetime an IVF offspring returns a positive net value to the State.
Time trends in sleep-onset difficulties among Norwegian adolescents: 1983—2005
Authors: Pallesen Ståle , Hetland Jørn , Sivertsen Børge , Samdal Oddrun , Torsheim Torbjørn , Nordhus Inger Hilde
Published: November 2008

Aims: To investigate trend data in the prevalence of sleep-onset difficulties among Norwegian adolescents covering the age groups 11, 13 and 15 years. Methods: Data were based on the Health Behaviour in School-aged Children — A WHO Cross-National Survey (HBSC) — and were collected on six occasions between 1983 and 2005. At each point in time data were obtained from representative samples comprising between 3402 and 5026 adolescents. Results: The prevalence of sleep-onset difficulties was higher among 11-year-old students compared to the 13- and 15-year-olds. Girls reported a higher prevalence than boys. A logistic regression analysis showed that the prevalence of sleep-onset difficulties overall had increased significantly since 1983, which constituted the reference year. When the analysis was broken down by age and gender, the same tendency was found in all groups. Conclusions: The prevalence of sleep-onset difficulties among adolescents has increased during the last decades. This development gives reason for concern and should receive more attention from teachers, parents and health professionals.
Costs of heart disease and risk behaviour: Implications for expenditure on prevention
Authors: Kruse Marie , Davidsen Michael , Madsen Mette , Gyrd-Hansen Dorte , Sørensen Jan
Published: November 2008

Aims: The objective of this paper is firstly to estimate the healthcare costs attributable to heart disease in Denmark using recently available data for 2002—05. Secondly, to estimate the attributable healthcare costs of lifestyle risk factors among heart patients, in order to inform decision making about prevention programmes specifically targeting patients with heart disease. Methods: For a cohort consisting of participants in a national representative health interview survey, register-based information about hospital diagnosis was used to identify patients with heart disease. Healthcare consumption during 2002— 05 among individuals developing heart disease during 2002—05 was compared with individuals free of heart disease. Healthcare costs attributable to heart disease were estimated by linear regression with adjustment for confounding factors. The attributable costs of excess drinking, physical inactivity and smoking among future heart patients were estimated with the same method. Results: Individuals with heart disease cost the healthcare system on average 3195 (p<0.0001) per person-year more than individuals without heart disease. The attributable cost of unhealthy lifestyle factors among individuals at risk of heart disease was about 11%—16% of the attributable cost of heart disease. Conclusions: Heart disease incurs significant additional costs to the healthcare sector, and more so if heart patients have a history of leading an unhealthy life. Consequently, strategies to prevent or cease unhealthy lifestyle may not only result in cost savings due to avoided heart disease. Additional cost savings may be obtained because heart patients who prior to the disease led a more healthy life consume fewer healthcare resources.