bluuebunny/crossref_metadata_2025 huggingface dataset:
The Use of External Transducers for Estimating Bone Strain at the Distal Tibia During Impact Activity
Authors: Edwards W. Brent , Ward Erin D. , Meardon Stacey A. , Derrick Timothy R.
Published: April 2009

Noninvasive methods for monitoring the in vivo loading environment of human bone are needed to determine osteogenic loading patterns that reduce the potential for bone injury. The purpose of this study was to determine whether the vertical ground reaction impact force (impact force) and leg acceleration could be used to estimate internal bone strain at the distal tibia during impact activity. Impact loading was delivered to the heels of human-cadaveric lower extremities. The effects of impact mass and contact velocity on peak bone strain, impact force, leg acceleration, and computed impact force (leg acceleration∗impact mass) were investigated. Regression analysis was used to predict bone strain from six different models. Apart from leg acceleration, all variables responded to impact loading similarly. Increasing impact mass resulted in increased bone strain, impact force, and computed impact force, but decreased leg acceleration. The best models for bone strain prediction included impact force and tibial cross-sectional area (R2=0.94), computed impact force and tibial cross-sectional area (R2=0.84), and leg acceleration and tibial cross-sectional area (R2=0.73). Results demonstrate that when attempting to estimate bone strain from external transducers some measure of bone strength must be considered. Although it is not recommended that the prediction equations developed in this study be used to predict bone strain in vivo, the strong relationship between bone strain, impact force, and computed impact force suggested that force platforms and leg accelerometers can be used for a surrogate measure of bone strain.
A Functional Role for Transposases in a Large Eukaryotic Genome
Authors: Nowacki Mariusz , Higgins Brian P. , Maquilan Genevieve M. , Swart Estienne C. , Doak Thomas G. , Landweber Laura F.
Published: April 2009

Editing the Genome

The ciliate
Oxytricha trifallax
has an unusual genome with the coding regions of genes (the exons) scattered through the genome. The exons are then somehow knitted together following transcription prior to their translation into proteins. As part of this process
Oxytricha
eliminates all transposable elements, stripping the genome down to 5% of the original germline DNA during development.

Nowacki
et al.

(p.
935
, published online 16 April) show that germline-limited transposases appear to be important for these large-scale DNA rearrangements.
Macrolichen communities in relation to soils and vegetation in the Noatak National Preserve, Alaska
Authors: Holt Emily A. , McCune Bruce , Neitlich Peter
Published: April 2009

Macrolichen community structure and its relation to environment in the Noatak National Preserve, Alaska, is described using a two-way stratified random sample. We found 201 macrolichen taxa. Two primary gradients in lichen species composition were related to substrate pH and vegetation physiognomy, grading from forests to high alpine communities. Site characteristics associated with the first community gradient are soil moisture and exposure. Both ends of this gradient, including protected forests and densely shrubby sites at one end and exposed, high elevation alpine sites at the other end, are relatively dry and well-drained. The mid-region of this gradient consists of mesic, lowland tundra habitats. The second gradient, related to substrate pH, is driven by the presence of Sphagnum moss contrasting with calcareous soils and bedrock. Combining these two gradients of lichen community composition, we found six groups of plots using two-way cluster analysis. Further, division of macrolichen species occurring in five or more plots yielded seven species groups, based on a combination of environmental factors and species distribution characteristics. This snapshot of macrolichen communities in Arctic Alaska serves as an important baseline for future comparisons to environments altered by changing climate and land use.
Balancing risks of disturbance from mountain pine beetle and western spruce budworm
Authors: Nealis V.G. , Noseworthy M.K. , Turnquist R. , Waring V.R.
Published: April 2009

The effect of removing lodgepole pine ( Pinus contorta Dougl. ex Loud.) and retaining Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) to reduce the risk of disturbance from mountain pine beetle ( Dendroctonus ponderosae Hopk.) in mixed conifer stands in southern British Columbia, Canada, on population processes influencing outbreaks of western spruce budworm ( Choristoneura occidentalis Free.) was evaluated in 10 paired (open vs. closed) field plots. Overall feeding damage to Douglas-fir was significantly, but only slightly, lower in open stands compared with closed stands. Although open plots tended to recruit more budworms, the losses resulting from the dispersal of spring-emerging budworms in search of feeding sites were significantly greater in open plots. The forest management benefits of these early season losses were mitigated, however, by more mortality of budworms from natural enemies, particularly diseases, in the closed plots during the budworm feeding period. These results are discussed in terms of compensating population processes and balancing objectives in forest pest management. In this case, selective harvesting of lodgepole pine as a mitigation strategy for the mountain pine beetle conserved the midterm timber supply potential represented by associated Douglas-fir even in the presence of an outbreak of the western spruce budworm.
A Mini Review of Traditional Chinese Medicine for the Treatment of Depression in China
Authors: Zhao Hui , Wan Xia , Chen Jia-Xu
Published: April 2009

To systematically evaluate the effectiveness of Chinese herbal medicine for treating depression in China, the electronic medical database from China National Knowledge Infrastructure (CNKI) was searched using Chinese and the date is set, from 1st January 1994 to 1st August 2008. The 18 studies that met the entry criteria along with 1,260 randomized patients were included in this review. All studies with words like "randomization" or "quasi-randomization" in their abstracts were included, whether they used blinding or not. The results showed that the Chinese medicine treated group did not decrease the scores of the self-rating depression scale (-1.02, 95% CI -2.16 ~ 0.12, p = 0.08) and the scores of the Hamilton depression scale (-0.45, 95% CI -0.98 ~ 0.08, p = 0.10). The results showed there is no evidence to support that traditional Chinese medicine for depression has improved, which may be due to the low quality in all the trials. Therefore, more qualified, randomized controlled clinical trials are warranted to assure its efficacy.
Effects of Far Infrared Acupoint Stimulation on Autonomic Activity and Quality of Life in Hemodialysis Patients
Authors: Su Ling-Hwa , Wu Kwan-Dun , Lee Li-Shan , Wang Harrison , Liu Chi-Feng
Published: April 2009

Patients receiving regular hemodialysis sessions have been known to suffer from fatigue and depression. This experiment was designed to determine the effects of far infrared ray (FIR) stimulation on acupoints of patients suffering from renal failure who are receiving regular hemodialysis. Patients receiving long-term and regular hemodialysis who volunteered for this procedure were randomly selected to undergo either FIR or heat pad (HP) therapy to determine the impact of FIR treatment on these patients. Both the activities of the autonomic nervous system and changes in quality of life were measured before and after treatment to determine the effectiveness of the FIR treatment. Results from this study show that FIR therapy decreases both stress and fatigue levels of these patients. It also stimulates autonomic nervous system (ANS) activity in patients who are diagnosed with end-stage renal disease (ESRD) and are receiving regular hemodialysis (HD). Therefore, benefits of FIR stimulation on these patients are clearly demonstrated in this preliminary study.
Antioxidant Effect of Tianwang Buxin Pills A Traditional Chinese Medicine Formula: Double-Blind, Randomized Controlled Trial
Authors: Gim Gyeong Taek , Kim Hyung-Min , Kim Jiyoung , Kim Jongwoo , Whang Wei-Wan , Cho Seung-Hun
Published: April 2009

Reactive oxygen species (ROS) and their derivatives play important roles in the development of diseases such as, cardiovascular disease, ischemic disease, and aging. Much effort has been devoted to finding both an effective and non-toxic antioxidant traditional Chinese medicine (TCM) herbal formula. Tianwang Buxin Pills (TBPs) have been used in TCM to treat mild cognitive impairment and palpitations. Recently, research has revealed that TBPs are effective against oxidative stress and psychological stress in experimental studies. However, randomized controlled trials (RCT) are rare. This study was conducted to assess the antioxidative and anti-stress effects of TBPs by analyzing (determination) reactive oxygen metabolites (d-ROMs test) of the blood, the stress response inventory (SRI), and the Korean version of the WHO Quality of Life Scale Abbreviated Version (WHOQOL-BREF) in 39 healthy volunteers (Placebo group = 20, TBPs group = 19) before and after oral administration of TBPs for 4 weeks. However, d-ROMs test, SRI, and WHOQOL-BREF values did not differ significantly between the two groups. These results indicate that TBPs do not effectively restrain ROS or their derivatives.
Collateral Theory and Vascular Lesion Treatment
Authors: Wu Yiling
Published: April 2009

The correlation between the collateral system of traditional Chinese medicine (TCM) and the vascular system of Western medicine was approached and the conception of "Mai" was analyzed. It was pointed out that "Mai" is an independent viscera with certain structure, function, and characteristics in metabolism. Ancient TCM physicians basically share the same knowledge on the vascular system with biomedicine in terms of its anatomical structure, but the distinctive TCM theory on qi-blood correlation can enrich the contents of the vascular system. The concept of "collateral-vascular system disease" was proposed based on ancient TCM literature and a clinical epidemiology survey on 3,469 cases with arteriosclerosis, approached by common pathological steps. The pathogenesis of vessel collateral-vascular system disease was investigated according to collateral theory, which pointed out the treatment principle — unblocking the collateral. Research in the treatment of cardio-cerebrovascular disease with Tongxinluo capsules — a representative formula. The relative treatment prescriptions are beneficial for the treatment of blood vessel lesion under the guidance of collateral theory in TCM, improving prevention and treatment level of vascular and related diseases.
β Cell Protecting and Immunomodulatory Activities of Paecilomyces Hepiali Chen Mycelium in STZ Induced T1DM Mice
Authors: Xiang Ming , Tang Jing , Zou Xiao-Lei , Zhao Zeng-Yu , Wang Yun-Yang , Xie Sheng-Nan
Published: April 2009

The anti-hyperglycemic and immunomodulatory activities of the ethanol extract from Paecilomyces Hepiali Chen (PHC), a Chinese medicine, were investigated in streptozotocin-induced type 1 diabetic (T1DM) mice. Male Balb/c mice, which were i.p. injected with streptozotocin (STZ, 50 mg/kg, for 5 consecutive days) on Day 7, were orally administered saline (the normal control and diabetic control group), Metformin (60 mg/kg, b.w., positive group), or the extract (100 mg/kg, b.w., PHC prevention group) from Day 1 to Day 28, Mice i.p. injected with streptozotocin (STZ, 50 mg/kg, b.w.) for 5 consecutive days prior to PHC treatment (100 mg/kg, b.w.) were used as the PHC treatment group. The effects of PHC on postprandial blood glucose concentrations, plasmatic insulin levels, morphology of pancreatic β cells and CD4+ T cells proliferation after 28-day treatment were monitored. Results showed that PHC administered 6 days before STZ induction of diabetes in mice significantly decreased blood glucose level (p < 0.01). An increase of insulin level was also observed as compared to those in the diabetic control group (p < 0.01). In addition, fewer inflammatory cells infiltrated the pancreatic islet and fewer β cells death by apoptosis within the inflamed islets were observed. More importantly, the CD4+ T cell proliferation was remarkably attenuated ex vivo in mice preventively treated with PHC (p < 0.01). In comparison to the PHC prevention group, no significant hypoglycemia, changes of insulin level and β cell protection were observed in mice treated with PHC after STZ administration. Our findings demonstrated that preventive administration of PHC protected β cells from apoptosis in type 1 diabetes induced by STZ, and the underlying mechanism may be involved in suppressing CD4+ T cells reaction, reducing inflammatory cells infiltration and protecting beta cell apoptosis in pancreatic islet.
Anti-Edema Effects of Brown Seaweed (Undaria pinnatifida) Extract on Phorbol 12-Myristate 13-Acetate-Induced Mouse Ear Inflammation
Authors: Khan Mohammed Nurul Absar , Yoon Seung-Je , Choi Jae-Suk , Park Nam Gyu , Lee Hyung-Ho , Cho Ji-Young , Hong Yong-Ki
Published: April 2009

The brown seaweed Undaria pinnatifida (Harvey) Suringar is used in traditional medicine to treat fever, urination problems, lumps and swelling, and as a dietary supplement for post-childbirth women. We examined the anti-inflammatory activities of the seaweed. The methanol extract of the seaweed was active against mouse ear edema induced by phorbol myristate acetate (PMA), with an IC50 of 10.3 mg/ml. The extract reduced the edema to a half-maximal level when applied at the concentration of 40 mg/ml within 3 hours before or 2 hours after application of PMA. Extract taken from the blade section of the seaweed demonstrated the highest activity. The Northern form of U. pinnatifida was more active than the Southern form. In the analgesic test, the methanol extract suppressed the acetic acid-induced writhing response, with an IC50 of 0.48 g/kg body weight. The extract also demonstrated antipyretic activity in yeast-induced hyperthermic mice. Activity-related constituents were arachidonic, eicosapentaenoic, and stearidonic acids.
Protective Effects of Natrii Sulfas on Cerebral Focal Ischemia Induced by MCAO in Rats
Authors: Sohn Youngjoo , Kang Ho Chang , Kim Kon Sik , Park Sun-Min , Sohn Nak-Won , Jung Hyuk-Sang , Kim Sung-Hoon
Published: April 2009

This study examined the effect of Natrii sulfas, a treatment for stroke patients suffering constipation in Oriental medicine, on the physiological indices and brain edema of rats. Brain edema was induced by a middle cerebral artery occlusion (MCAO), Natrii sulfas was administered after the MCAO. At 3, 6, 15, 24, and 48 hours after reperfusion, the physiological indices such as the fecal weight, urine volume and water content in the stools were assessed. The edema index was measured 48 hours after reperfusion. At 48 hours, the expressions of iNOS, MMP9, VEGF, GFAP, Bax, Bcl-2, c-Fos, and HSP72 positive astrocytes were observed on the brain tissues by immunohistochemistry. Natrii sulfas significantly improved the decrease in fecal weight, urine volume and water content in the stool caused by the ischemic insult (p < 0.05) and attenuated the brain edema caused by the ischemia insult (p < 0.05). Natrii sulfas significantly down-regulated iNOS and MMP9 expressions and attenuated the astrocyte swelling due to brain edema in the penumbra of the cerebral cortex of MCAO rats. Natrii sulfas reduced the excess Bax and HSP72 expressions in ischemic brain, which was statistically significant in the penumbra of the cerebral cortex but not in the caudate putamen. These results suggest Natrii sulfas has a protective effect on ischemia-induced brain edema and improves the physiological symptoms.
Effect of Total Glucosides of Paeony on the Expression of Nephrin in the Kidneys from Diabetic Rats
Authors: Zhang Pei , Zhang Jing-Jing , Su Jing , Qi Xiang-Ming , Wu Yong-Gui , Shen Ji-Jia
Published: April 2009

Total glucosides of paeony (TGP), extracted from the traditional Chinese herb root of Paeonia lactiflora pall, have been shown to have a therapeutic role in experimental diabetic nephropathy including albuminuria. Recent investigation has identified nephrin, a podocyte-specific transmembrane protein, as a key regulator in the pathogenesis of diabetic albuminuria. The aim of this study was to investigate whether TGP can attenuate albuminuria through prevention of nephrin loss in the experimental diabetic nephropathy. Fifty male Munich-Wistar rats were obtained from the Experimental Animal Center of Anhui Medical University. These rats were divided into 5 groups (n = 10); normal group, control diabetic group, and 3 TGP treated diabetic groups at different concentrations. Diabetes was induced by streptozotocin, and TGP (50, 100, 200 mg/kg) was orally administered to the 3 TGP treated diabetic groups once a day for 8 weeks, respectively. Blood glucose and 24 hour urinary albumin excretion rate (AER) were measured. The expressions of nephrin, tumor necrosis factor-α (TNF-α), NF-κB p65 and 3-nitrotyrosine (3-NT) protein were determined by immunoinfluorescence or Western blot analysis in the kidneys. Elevated AER was markedly attenuated by TGP treatment in diabetic rats. There was a finely dotted linear epithelial staining of nephrin in normal group glomeruli. In contrast, the staining of glomeruli from untreated diabetic rats was attenuated, more diapersed, and clustered. This diabetic-induced loss of glomerular nephrin expression was prevented in a large degree in TGP-treated diabetic rats. Western blot analysis showed that the expression of nephrin protein was reduced in the kidneys of diabetic rats, but significantly increased in the TGP treatment groups. The expressions of TNF-α, NF-κB p65 and 3-NT protein were significantly increased in the kidneys of diabetic rats, which were all significantly inhibited by TGP treatment. Our results showed that TGP could decrease AER in diabetic rat, and that its mechanism may be at least partly correlated with upregulation of the expression of nephrin in the kidney.
Study on Pretreatment of FPS-1 in Rats with Hepatic Ischemia-Reperfusion Injury
Authors: Lin Shiqing , Liu Kexuan , Wu Weikang , Chen Chao , Wang Zhi , Zhang Xuanhong
Published: April 2009

This study was designed to determine whether FPS-1, the water-soluble polysaccharide isolated from fuzi, protected against hepatic damage in hepatic ischemia-reperfusion injury in rats, and its mechanism. SD rats were subjected to 60 min of hepatic ischemia, followed by 120 min reperfusion. FPS-1 (160 mg/kg/day) was administered orally for 5 days before ischemia-reperfusion injury in treatment group. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and albumin (ALB) were assayed to evaluate liver functions. Liver samples were taken for histological examination and determination of malondialdehyde (MDA), superoxide dismutase (SOD), that catalase (CAT) in liver. Na+- K+-ATPase and Ca2+-ATPase in mitochondria were measured with colorimetry method. Morphological changes were also investigated by using both light microscopy and electron microscopy (EM). In addition, apoptosis and oncosis were detected by Annexin V-FITC/PI immunofluorescent flow cytometry analysis. Serum AST and ALT levels were elevated in groups exposed to ischemia-reperfusion (p < 0.05). Ischemia-reperfusion caused a marked increase in MDA level, and significant decreases in hepatic SOD and CAT (p < 0.05). Na+- K+-ATPase and Ca2+-ATPase were reduced in ischemia-reperfusion groups compared to the sham group (p < 0.05). Oncosis and apoptosis were also observed in ischemia-reperfusion groups. Pretreatment with FPS-1 reversed all these biochemical parameters as well as histological alterations, evidently by increased SOD, CAT, reduced MDA and histological scores compared to the model group (p < 0.05). FPS-1 could attenuate the necrotic states by the detection of immunofluorescent flow cytometry analysis. Pretreatment with FPS-1 reduced hepatic ischemia-reperfusion injury through its potent antioxidative effects and attenuation of necrotic states.
Uncaria rhynchophyllaandRhynchophyllineInhibit c-Jun N-Terminal Kinase Phosphorylation and Nuclear Factor-κB Activity in Kainic Acid-Treated Rats
Authors: Hsieh Ching-Liang , Ho Tin-Yun , Su Shan-Yu , Lo Wan-Yu , Liu Chung-Hsiang , Tang Nou-Ying
Published: April 2009

Our previous studies have shown that Uncaria rhynchophylla (UR) can reduce epileptic seizures. We hypothesized that UR and its major component rhynchophylline (RH), reduce epileptic seizures in rats treated with kainic acid (KA) by inhibiting nuclear factor-κB (NF-κB) and activator-protein-1 (AP-1) activity, and by eliminating superoxide anions. Therefore, the level of superoxide anions and the DNA binding activities of NF-κB and AP-1 were measured. Sprague-Dawley (SD) rats were pre-treated with UR (1.0 g/kg, i.p.), RH (0.25 mg/kg, i.p.), or valproic acid (VA, 250 mg/kg, i.p.) for 3 days and then KA was administered intra-peritoneal (i.p.). The results indicated that UR, RH, and VA can reduce epileptic seizures and the level of superoxide anions in the blood. Furthermore, KA was demonstrated to induce the DNA binding activities of NF-κB and AP-1. However, these inductions were inhibited by pre-treatment with UR, RH, or VA for 3 days. Moreover, UR and RH were shown to be involved in the suppression of c-Jun N-terminal kinase (JNK) phosphorylation. This study suggested that UR and RH have antiepileptic effects in KA-induced seizures and are associated with the regulation of the innate immune system via a reduction in the level of superoxide anions, JNK phosphorylation, and NF-κB activation.
SYNCHRONOUS-TO-ASYNCHRONOUS CONVERSION OF CRYPTOGRAPHIC CIRCUITS
Authors: CASSIA RICARDO F. , ALVES VLADIMIR C. , BESNARD FEDERICO G.-D. , FRANÇA FELIPE M. G.
Published: April 2009

This paper introduces a novel method for the conversion of synchronous cryptographic circuits into equivalent asynchronous ones. The new method is based on ASERT (Asynchronous Scheduling by Edge Reversal Timing), a fully decentralized timing signaling and synchronization algorithm. From a synthesizable HDL code, an asynchronous timing network, made from standard cells libraries, is generated in order to replace the clock tree of the target circuit. ASERT works with matched delays, local clocks or any equivalent way of determining, statically or dynamically, the operating time of each functional unit. Synchronous to asynchronous conversion of three different cryptographic circuits, including the fully synthesized netlists of AES, Reed-Solomon decoder, and RSA cipher cores, are presented.
670-nA CMOS OTA FOR AMLCD COLUMN DRIVER
Authors: PENNISI SALVATORE , DI FAZIO SALVATORE , SIGNORELLI TIZIANA , PULVIRENTI FRANCESCO
Published: April 2009

A transconductance operational amplifier specifically optimized for a switched-capacitor LCD column driver is presented. It exploits MOS transistors in subthreshold region and dissipates 670 nA at DC. Despite this extremely low quiescent current value, the amplifier exhibits a DC gain of about 80 dB, and a gain-bandwidth product and phase margin around 2 MHz and 70°, with a load capacitance of 500 fF. Besides, working in class AB, the solution provides a slew rate equal to 27 V/μs. With exception of the DC gain, these performances represent an improvement with respect to comparable solutions, and are obtained while halving the area occupation.
ANALYSIS OF CAROTID ARTERIAL DOPPLER SIGNALS USING STFT AND WIGNER–VILLE DISTRIBUTION (WVD)
Authors: AMINA MELLE SEDDIK , FETHI M. BEREKSI REGUIG
Published: April 2009

The study presented in this paper is concerned with the analysis of the ultrasound Doppler signal of the carotid arteries in the time-frequency domain using the short time Fourier transform (STFT) and the Wigner–Ville distribution (WVD). This study is carried out in order to investigate the behavior of the spectral broadening index (SBI) derived from spectra obtained using these methods. The variations in the shape of the Doppler power spectra as a function of time are presented in the form of sonograms in order to determine the degree of primitive carotid artery stenosis. The obtained results show a qualitative improvement in the appearance of the sonograms generated using the WVD over the STFT. However, despite this qualitative improvement the WVD suffers from some drawbacks: the presence of the cross terms which are primarily due to its quadratic nature. The application of the Choi–Williams distribution (CWD) in this analysis shows a noticeable reduction of these cross terms, improving therefore the quality of the sonograms. From these generated sonograms, the ultrasound frequency envelopes are extracted. The maximum and the mean frequencies in these envelopes are used to determine the SBI. The magnitude of the CWD-SBI is significantly greater than that of the STFT-SBI. In addition, there is a correlation between the SBIs obtained using the STFT and the CWD and the degree of severity of stenosis measured by 2D Doppler imaging.
THE EFFECTS OF PARALLEL AND SERIES ELASTIC COMPONENTS ON THE ACTIVE CAT SOLEUS FORCE-LENGTH RELATIONSHIP
Authors: RODE CHRISTIAN , SIEBERT TOBIAS , HERZOG WALTER , BLICKHAN REINHARD
Published: April 2009

Typically, active muscle force is calculated by subtracting measured passive force from measured total force for corresponding whole muscle lengths (standard method). From a mechanical point of view, this requires a parallel elastic component (PEC) that is arranged in parallel to both the series elastic component (SEC) and the contractile component (CC). From a morphological point of view, however, the PEC should be rather in parallel to the CC, and both in series to the SEC (model [CC]). In this study, we investigated the differences in active muscle force estimated with these two different approaches and their impact on the interpretation of experiments. We measured passive forces without stimulation and total forces during supramaximal stimulation of six cat soleus muscles in end-held isometric contractions from lengths near active insufficiency to lengths close to inducing stretch damage. The active forces estimated with model [CC] reach about 10% higher maximum isometric forces and reveal about 10% longer optimal lengths of the CC compared to the standard method. Model choice affects the interpretation of the physiological working range and residual force enhancement. The active force-length relationships of the contractile component determined with model [CC] agree better with the theoretical sarcomere force-length relationship.
EFFECT OF THERMAL DAMAGE ON COMPRESSIVE BEHAVIOR OF SKIN TISSUE
Authors: XU F. , LU T. J. , SEFFEN K. A.
Published: April 2009

Biothermomechanics of skin tissue is highly interdisciplinary, involving bioheat transfer, burn damage, biomechanics and physiology. Characterization of the thermomechanical behavior of skin tissue is of great importance and can contribute to a variety of medical applications. However, few studies have attempted to address the influence of heat induced thermal damage on the mechanical properties of skin tissue. This paper presents the compressive behavior of pigskin at different thermal damage levels and discusses the possible mechanisms of thermal damage–dependent compressive behavior of skin. The results demonstrate that skin stiffness decreases with increasing thermal damage degree and there exists strain rate sensitivity at different damage levels, caused mainly by hydration changes.
Transpulmonary passage of99mTc macroaggregated albumin in healthy humans at rest and during maximal exercise
Authors: Lovering Andrew T. , Haverkamp Hans C. , Romer Lee M. , Hokanson John S. , Eldridge Marlowe W.
Published: April 2009

We have demonstrated that 50-μm-diameter arteriovenous pathways exist in isolated, healthy human and baboon lungs, ventilated and perfused under physiological pressures. These findings have been confirmed and extended by demonstrating the passage of 25-μm microspheres through the lungs of exercising dogs, but not at rest. Determination of blood flow through these large-diameter intrapulmonary arteriovenous pathways would be an important first step to establish a physiological role for these vessels. Currently, we sought to estimate blood flow through these arteriovenous pathways using technetium-99m (99mTc)-labeled macroaggregated albumin (MAA) in healthy humans at rest and during maximal treadmill exercise. We hypothesized that the percentage of99mTc MAA able to traverse the pulmonary circulation (%transpulmonary passage) would increase during exercise. Seven male subjects without patent foramen ovale were injected with99mTc MAA at rest on 1 day and during maximal treadmill exercise on a separate day (>6 days). Within 5 min after injection, subjects began whole body imaging in the supine position. Six of the seven subjects showed an increase in transpulmonary passage of MAA with maximal exercise. Using two separate analysis methods, percent transpulmonary passage significantly increased with exercise from baseline to absolute values of 1.2 ± 0.8% ( P = 0.008) and 1.3 ± 1.0% ( P = 0.016), respectively (means ± SD; paired t-test). We conclude that MAA may be traversing the pulmonary circulation via large-diameter intrapulmonary arteriovenous conduits in healthy humans during exercise. Recruitment of these pathways may divert blood flow away from pulmonary capillaries during exercise and compromise the lung's function as a biological filter.
Multiphoton Imaging of Renal Regulatory Mechanisms
Authors: Peti-Peterdi János , Toma Ildikó , Sipos Arnold , Vargas Sarah L.
Published: April 2009

Most physiological functions of the kidneys, including the clearance of metabolic waste products, maintenance of body fluid, electrolyte homeostasis, and blood pressure, are achieved by complex interactions between multiple renal cell types and previously inaccessible structures in many organ parts that have been difficult to study. Multiphoton fluorescence microscopy offers a state-of-the-art imaging technique for deep optical sectioning of living tissues and organs with minimal deleterious effects. Dynamic regulatory processes and multiple functions in the intact kidney can be quantitatively visualized in real time, noninvasively, and with submicron resolution. This article reviews innovative multiphoton imaging technologies and their applications that provided the most complex, immediate, and dynamic portrayal of renal function—clearly depicting as well as analyzing the components and mechanisms involved in renal (patho)physiology.
Erythrocytes: Oxygen Sensors and Modulators of Vascular Tone
Authors: Ellsworth Mary L. , Ellis Christopher G. , Goldman Daniel , Stephenson Alan H. , Dietrich Hans H. , Sprague Randy S.
Published: April 2009

Through oxygen-dependent release of the vasodilator ATP, the mobile erythrocyte plays a fundamental role in matching microvascular oxygen supply with local tissue oxygen demand. Signal transduction within the erythrocyte and microvessels as well as feedback mechanisms controlling ATP release have been described. Our understanding of the impact of this novel control mechanism will rely on the integration of in vivo experiments and computational models.
AKAP-Scaffolding Proteins and Regulation of Cardiac Physiology
Authors: Mauban J. R. H. , O’Donnell M. , Warrier S. , Manni S. , Bond M.
Published: April 2009

A kinase anchoring proteins (AKAPs) compose a growing list of diverse but functionally related proteins defined by their ability to bind to the regulatory subunit of protein kinase A. AKAPs perform an integral role in the spatiotemporal modulation of a multitude of cellular signaling pathways. This review highlights the extensive role of AKAPs in cardiac excitation/contraction coupling and cardiac physiology. The literature shows that particular AKAPs are involved in cardiac Ca2+influx, release, reuptake, and myocyte repolarization. Studies have also suggested roles for AKAPs in cardiac remodeling. Transgenic studies show functional effects of AKAPs, not only in the cardiovascular system but in other organ systems as well.
Re-expression of Locomotor Function After Partial Spinal Cord Injury
Authors: Rossignol S. , Barrière G. , Alluin O. , Frigon A.
Published: April 2009

After a complete spinal section, quadruped mammals (cats, rats, and mice) can generally regain hindlimb locomotion on a treadmill because the spinal cord below the lesion can express locomotion through a neural circuitry termed the central pattern generator (CPG). In this review, we propose that the spinal CPG also plays a crucial role in the locomotor recovery after incomplete spinal cord injury.
The Attractors of the Common Differential Operator Are Determined by Hyperbolic and Lacunary Functions
Authors: Bayer Wolf
Published: April 2009

For analytic functions, we investigate the limit behavior of the sequence
of their derivatives by means of Taylor series, the attractors are
characterized by ω‐limit sets. We describe four different classes of functions,
with empty, finite, countable, and uncountable attractors. The paper reveals that Erdelyiés hyperbolic functions of higher order and lacunary functions play an important role for orderly or chaotic behavior. Examples are given for the sake of confirmation.
Technological Capabilities of Automotive Firms in Indonesia and Malaysia
Authors: Rasiah Rajah
Published: April 2009

This paper examines differences in technological capabilities and the statistical relationships in a sample of automotive firms in Indonesia and Malaysia. The results show that firms in Indonesia, which has a liberalized trade regime, enjoyed higher human resource, process technology, and research and development (R&D) capabilities than firms in Malaysia, which has protected trading policies. Statistical relationships largely support theoretical arguments about R&D and the explanatory variable of foreign ownership in Indonesia where the relationship between the two is significant and negative. Foreign ownership was negatively correlated with human resource and positively correlated with process technology in Malaysia. The overall results show that there is a need to increase external competition and human capital supply for automotive firms in Malaysia to raise their technological capabilities.
Mass Murder at School and Cumulative Strain
Authors: Levin Jack , Madfis Eric
Published: April 2009

To explain the genesis of mass murder committed by students at their schools, the authors propose a five-stage sequential model in which several criminological theories (strain theory, control theory, and routine activities theory) are brought to bear collectively to demonstrate their cumulative effect. These stages are as follows: chronic strain, uncontrolled strain, acute strain, the planning stage, and the massacre. Long-term frustrations (chronic strains) experienced early in life or in adolescence lead to social isolation, and the resultant lack of prosocial support systems (uncontrolled strain) in turn allows a short-term negative event (acute strain), be it real or imagined, to be particularly devastating. As such, the acute strain initiates a planning stage, wherein a mass killing is fantasized about as a masculine solution to regain lost feelings of control, and actions are taken to ensure the fantasy can become reality. The planning process concludes in a massacre facilitated by weapons that enable mass destruction in schoolrooms and campuses, where students are closely packed together. Based on this analysis, prevention strategies are suggested.
The Economic Effects of Business to Business Internet Activity
Authors: Brookes Martin , Wahhaj Zaki
Published: April 2009

This article argues that an effective way to analyse the macroeconomic effects of business-to-business electronic commerce is to regard it as a decline in the cost of information to producers. Calculations based on input-output tables and the IMF's Multimod macroeconomic model show that current estimates of such savings translate into about a 5 per cent long-run increase in output in the major industrialised economies. In the medium term, although the deflationary effects of the shock would provide greater room to central banks to keep interest rates low, the simulation results also hint at short-term inflation risks if current demand outstrips supply in anticipation of higher future incomes.
A Long View of the UK Business Cycle
Authors: Chadha Jagjit S. , Nolan Charles
Published: April 2009

We outline a number of ‘stylised’ facts on the UK business cycle obtained from analysis of the long-run UK annual dataset. The findings are to some extent standard. Consumption and investment are pro-cyclical, with productivity playing a dominant role in explaining business cycle fluctuations at all horizons. Money neutrality obtains over the long run but there is clear evidence of non-neutrality over the short run, particularly at the business cycle frequencies. Business cycle relationships with the external sector via the real exchange rate and current account are notable. Postwar, the price level is counter-cyclical and real wages are pro-cyclical, as are nominal interest rates. Modern general equilibrium macroeconomic models capture many of these patterns.
Associations of Future Expectations, Negative Friends, and Academic Achievement in High-Achieving African American Adolescents
Authors: Cunningham Michael , Corprew Charles S. , Becker Jonathan E.
Published: April 2009

The relations of future expectations (general and academic) to academic outcomes were examined in a sample of 129 African American high-achieving adolescents (majority female participants, n = 92). This study was interested in the multidimensional nature of future expectations. Results from the study confirm the hypothesis that academic future expectations accounted for more variance in the relation to academic outcomes than general future expectations. In addition, the results suggest that the association of academic future expectations to grade point average lessens in the presence of negative friends. Suggestions for future research are offered.
Study of process/structure/property relationships in friction stir welded thin sheet Al–Cu–Li alloy
Authors: Shukla A. K. , Baeslack W. A.
Published: April 2009

Microstructure evolution in friction stir welds produced in artificially aged Al–4Cu–1Li–0·36Mg–0·14Zr–0·28Ag alloy over a range of process parameters was studied using transmission electron microscopy. Process parameters did not have a major effect on the weld microstructure and mechanical properties. The stir zone exhibited an appreciable decrease in hardness relative to the unaffected base metal due to dissolution of T1 and θ′ precipitates. The heat affected zone exhibited almost complete dissolution of θ′ precipitates and partial dissolution of T1 precipitates. The effect of process conditions on T1 precipitate density in the heat affected zone was studied and it was found that dissolution was experienced at lower tool rotation speed to traverse rate ratios, while welds produced at higher tool rotation speed to traverse rate ratios experienced both dissolution and growth of T1 precipitates. The results obtained on this thin sheet aluminium alloy were compared to those of friction stir welds produced in thicker sections of the same alloy.
Influence of clamping on distortion of welded S355 T-joints
Authors: Schenk T. , Richardson I. M. , Kraska M. , Ohnimus S.
Published: April 2009

Welding almost always leads to some distortion of a structure due to its strongly time dependent and localised heat input. This distortion is usually undesirable and causes problems related to alignment and fit-up tolerances with adjacent structures. Considerable research has been carried out on different mitigation methods to reduce distortion to manageable levels; however, most of this has been for a single, simple set of clamping conditions. In practice, clamping is often required and the choice of restraint conditions and subsequent influence on distortion should be explored. This paper examines gas metal arc welds made on S355 T-joints under different clamping conditions. Measured welding temperatures and subsequent part distortions are shown for two different clamping conditions and compared to simulations. The interaction of the clamps and the workpiece due to the material reaction is examined by recording the transient clamping force. It is shown that the clamping condition strongly affects the welding distortion amplitude and might even alter the distortion mode.
Effects of weld preheat temperature and heat input on type IV failure
Authors: Francis J. A. , Cantin G. M. D. , Mazur W. , Bhadeshia H. K. D. H.
Published: April 2009

Type IV cracking refers to the premature failure of a welded joint due to an enhanced rate of creep void formation in the fine grained or intercritically annealed heat affected zone. A great deal of research effort has been directed at understanding the underlying mechanisms for this type of failure, but most have approached the problem from a metallurgical standpoint, and comparatively little effort has been directed at understanding the effects of welding variables. Here the effects of parameters such as the preheat temperature and heat input on the tendency for type IV failure in 9–12%Cr steels have been quantitatively estimated. These calculations have subsequently been verified experimentally to form the first systematic study of welding parameters on type IV cracking. The joint geometry and preheat temperature have been found to ameliorate type IV failures, while the effect of heat input is less significant.
Model based optimisation of friction stir welding processes
Authors: Liao T. W. , Daftardar S.
Published: April 2009

This paper proposes a model based approach for the optimisation of friction stir welding processes. The proposed approach starts with building a model of the process. For this study, the thermal model developed by Chao and his associate for friction stir welding of AA 2195-T8 is replicated using Fluent. Once developed, the thermal model is then used to simulate the process. Two surrogate models, one linear and one non-linear, are constructed to relate three process parameters with maximum temperature at a selected location, using the simulation data generated by the thermal model. A constrained optimisation model is next formulated, which is eventually solved by five population based metaheuristrics to find the optimal solutions for the studied friction stir welding process. The optimal solutions are primarily constrained by the lower bound of the temperature. The lower this lower bound temperature is the higher travel speed can go. The linear surrogate model results in a slightly better optimal solution than the non-linear model when the temperature constraint is loose and the converse is true when the temperature constraint is tight. Comparing all five metaheuristics, differential evolution has the best performance, followed by particle swarm optimisation, ant colony optimisation, genetic algorithm, and lastly harmony search.
Welding distortion investigation in fillet welded joint and structure based on iterative substructure method
Authors: Wang R. , Zhang J. X. , Liu C. , Serizawa H. , Murakawa H.
Published: April 2009

In this paper, prediction and controlling angular distortion in fillet welded joint and structure were investigated. First, two methods to reduce angular distortion in fillet welded joint were investigated by experimental and numerical analysis. One was to apply a constant external force in-process and the other was rigid clamping. In numerical analysis, a new in-house finite element code has been developed based on the idea of iterative substructure method (ISM) to calculate welding distortion in rational time. During experimental analysis, the constant external force was designed and applied in-process to reduce angular distortion of fillet welded joint. The results showed that the distortion can be efficiently predicted by ISM, which were in good agreement with the experimental ones. Applying constant external force in process was a more effective method to reduce distortion than using rigid clamping. In addition, with a constant load distance from weld bead, the locations of the applied constant external force and rigid clamping along the longitudinal direction (welding direction) have little influence on the magnitude of welding angular distortion. Finally, the angular distortion of a large fillet welded structure was predicted with ISM and also controlled with applying a constant external force based on the simulation results of the fillet welded joint.
On mechanism of fatigue fracture in interstitial free steel sheet
Authors: Majumdar S. , Bhattacharjee D. , Ray K. K.
Published: April 2009

The mechanism of fatigue fracture in an interstitial free steel sheet has been studied. The process can be divided into four regimes:

(i) the fatigue crack initiates on the specimen surface, from the mesocracks along the grain boundaries in stage I

(ii) propagates mostly in an opening mode through grain boundaries in stage II

(iii) propagates through microscopic striations and transverse intergranular cracking briefly in stage III

(iv) the crack path changes from flat to slant along with through thickness necking and it propagates to failure through discrete crack jumps in stage IV. The crack jumps are associated with crack progression marks (CPMs), the spacing of which increases exponentially from few micrometres to few hundred micrometres with crack length.
Microstructures and precipitation behaviour of cryomilled Al–Zn–Mg–Cu–Mn powders
Authors: Cai Y. H. , Cui H. , Zhang J. S.
Published: April 2009

Supersaturated Al–Zn–Mg–Cu–Mn alloy powder was fabricated by rapidly solidification and cryomilling methods. The microstructures and its evolution of the as cryomilled powders during subsequent processing were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that both of diffraction peak shift and broadening are occurred because of dissolution of large numbers of alloying elements into α-Al matrix after cryomilling. The only equilibrium phase precipitated from supersaturated α-Al is η (MgZn2) phase when annealing temperature is below 350°C. No metastable Mn containing precipitate is found when annealing temperature is below 350°C or at 350°C for a short time. When the powder is heated at 350°C for a long time or a high temperature above 350°C, the nano scaled stable Al6Mn particles with a uniform distribution precipitates directly from α-Al matrix, however, transition Mn containing phase is not detected by both XRD and SEM methods.
Recrystallisation processes in cold rolled low carbon steel strip containing different starting microstructures
Authors: Xu W. , Ferry M.
Published: April 2009

The effect of initial microstructure [acicular ferrite (AF); polygonal ferrite (PF); fine polygonal ferrite (FPF); bainite (B)] on the recrystallisation behaviour of cold rolled low carbon (LC) steel strip was investigated. Steel strip samples of 2 mm thickness were heat treated to produce FPF, PF, AF and B. The resulting materials, together with a twin roll cast LC strip containing predominantly acicular ferrite (SC), were cold rolled to 50, 70 and 90% reduction and annealed for various times in the temperature range 580–680°C. The evolution of microstructure during rolling and recrystallisation was studied by optical microscopy, electron backscatter diffraction in SEM and TEM. The initial microstructure was found to have a substantial influence on the annealing behaviour. Recrystallisation was structure dependent with the rate of recrystallisation shown as FPF>B>PF>AF>SC during annealing at temperatures in the range 580–680°C. Both partly and fully recrystallised materials exhibited approximately lognormal grain size distributions with the PF and B having the largest and smallest average grain sizes and standard deviations and the smallest and largest skewness respectively.