bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECTS OF CONSTRAINTS ON BIPEDAL BALANCE CONTROL DURING STANDING
Authors: YANG C. , WU Q. , JOYCE G.
Published: January 2008

In this work, the effects of the gravity constraint, friction constraint, center of pressure (COP) constraint, and tip-over constraint on balance control of a simplified two-dimensional biped during standing are investigated. The bounds imposed on the control torque due to the constraints are first determined. Such control bounds have significant effects on designing balance control laws and can be used to predict the type of falls if the constraint is violated. It is found that there exists a critical angular velocity, above which, regardless of the control torque, the constraints will be violated. It is also found that the gravity constraint is the least important since it is always satisfied when the friction constraint is satisfied. For the biped under study, the friction constraint determines the critical angular velocity in most of the region around the upright position, while the COP constraint dictates the bounds of the control torque. Since the tip-over constraint is equivalent to the COP constraint as both feet are on the same level ground, it is concluded that the tip-over constraint is the most important when the magnitude of the angular velocity is below the critical value.
The Gataia Pleistocene lamproite: a new occurrence at the southeastern edge of the Pannonian Basin, Romania
Authors: Seghedi I. , Ntaflos T. , Pécskay Z.
Published: January 2008

The petrological identity of the lamproite occurrence situated
c
. 5 km south of Gătaia (Banat, western Romania), until now considered to be an alkali basalt, has been revealed by exploration drilling. This drilling programme pierced a slightly vesicular lava flow inside the Şumiga hill (198 m above sea level), revealing a sequence of vesicular lava intercalated with fallout scoria deposits. The isolated lamproite volcano, dated at 1.32±0.06 Ma (whole-rock K/Ar method), is situated at the southeastern margin of the Pannonian Basin and at the western margin of the South Carpathians, along an important NE–SW fault system. The lamproite magma erupted through flat-lying Miocene sedimentary rocks, which overlie older crystalline basement that experienced intense lithospheric deformation and orogeny during Cretaceous times. The lamproite is associated with contemporaneous volcanic activity that lies 50–150 km to the NNE, along the South Transylvanian fault system (Lucareţ alkali basalts, Uroiu shoshonites); these rocks, however, are not consanguineous, and derive from different mantle sources. There are, however, similarities to Oligocene lamproites from Serbia (Bogovina), generated on similar basement. The lamproite is fresh and has a slightly porphyritic texture with phenocrysts of high-Mg olivine and microphenocrysts of euhedral leucite in a glassy matrix. The matrix also contains microcrysts of olivine, armalcolite, apatite, sanidine, low Al-diopside, fluorine-bearing titanium phlogopite, fluorine-bearing amphibole and accessory chrome spinels. Ba-sulphate aggregates fill small vesicles. Very rare clots of corroded Al-phlogopite surrounded by secondary spinels are enclosed by leucite aggregates, suggesting formation during an earlier event. Major and trace element geochemistry and Sr and Nd isotopes show that the rock is a typical lamproite, close to the compositions of Leucite Hills and Gaussberg lamproites. The source for the Gătaia lamproite was probably a garnet harzburgite lithospheric mantle, metasomatized by alkaline mafic melts, most probably active at the Cretaceous–Palaeogene boundary. Metasomatism by alkaline melts is indicated by high abundances of incompatible trace elements, such as Ba, Sr, Rb and Zr. The Gătaia lamproite probably had a limited available source volume for melting that reflects the ambient thermal regime in the typical post-collisional tectonic setting active during Late Neogene to Quaternary time. Emplacement of this lamproite was probably a result of surface uplift and erosion at the base of the lithosphere, marking the collapse of the Alpine orogen.
Specific knockdown of m-calpain blocks myogenesis with cDNA deduced from the corresponding RNAi
Authors: Honda Michiyo , Masui Fujiko , Kanzawa Nobuyuki , Tsuchiya Takahide , Toyo-oka Teruhiko
Published: January 2008

Fusion of mononuclear myoblast to multinucleated myotubes is crucial for myogenesis. Both μ- and m-calpain are ubiquitously expressed in most cells and are particularly abundant in muscle cells. Knockout of calpain-1 (catalytic subunit of μ-calpain) induced moderate platelet dysaggregation, preserving the normal development and growth, although knockout of calpain-2 (m-calpain) is lethal in mice. Therefore, there should be muscle-specific function of m-calpain per se. Previous methods lack direct evidence for the involvement of m-calpain, because the specific inhibitor to m-calpain has not been developed yet and the inhibition was less potent. Here, we show that screened RNA interference (RNAi) specifically blocked the m-calpain expression by 95% at both the protein and the activity levels. After transfection of adenovirus vector-mediated cDNA corresponding to the RNAi-induced short hairpin RNA, m-calpain in C2C12myoblasts was knocked down with no compensatory overexpression of μ-calpain or calpain-3. The specific knockdown strongly inhibited the fusion to multinucleated myotubes. In addition, the knockdown modestly blocked ubiquitous effects, including cell migration, cell spreading, and alignment of central stress fiberlike structures. These results may indicate that m-calpain requiring millimolar Ca2+level for the full activation plays specific roles in myogenesis, independent of μ-calpain, and leave us challenging problems in the future.
Apical maxi-K (KCa1.1) channels mediate K+ secretion by the mouse submandibular exocrine gland
Authors: Nakamoto Tetsuji , Romanenko Victor G. , Takahashi Atsushi , Begenisich Ted , Melvin James E.
Published: January 2008

The exocrine salivary glands of mammals secrete K+ by an unknown pathway that has been associated with HCO3− efflux. However, the present studies found that K+ secretion in the mouse submandibular gland did not require HCO3−, demonstrating that neither K+/HCO3− cotransport nor K+/H+ exchange mechanisms were involved. Because HCO3− did not appear to participate in this process, we tested whether a K channel is required. Indeed, K+ secretion was inhibited >75% in mice with a null mutation in the maxi-K, Ca2+-activated K channel (KCa1.1) but was unchanged in mice lacking the intermediate-conductance IKCa1 channel (KCa3.1). Moreover, paxilline, a specific maxi-K channel blocker, dramatically reduced the K+ concentration in submandibular saliva. The K+ concentration of saliva is well known to be flow rate dependent, the K+ concentration increasing as the flow decreases. The flow rate dependence of K+ secretion was nearly eliminated in K Ca 1.1 null mice, suggesting an important role for KCa1.1 channels in this process as well. Importantly, a maxi-K-like current had not been previously detected in duct cells, the theoretical site of K+ secretion, but we found that KCa1.1 channels localized to the apical membranes of both striated and excretory duct cells, but not granular duct cells, using immunohistochemistry. Consistent with this latter observation, maxi-K currents were not detected in granular duct cells. Taken together, these results demonstrate that the secretion of K+ requires and is likely mediated by KCa1.1 potassium channels localized to the apical membranes of striated and excretory duct cells in the mouse submandibular exocrine gland.
TNF-α/cycloheximide-induced apoptosis in intestinal epithelial cells requires Rac1-regulated reactive oxygen species
Authors: Jin Shi , Ray Ramesh M. , Johnson Leonard R.
Published: January 2008

Previously we have shown that both Rac1 and c-Jun NH2-terminal kinase (JNK1/2) are key proapoptotic molecules in tumor necrosis factor (TNF)-α/cycloheximide (CHX)-induced apoptosis in intestinal epithelial cells, whereas the role of reactive oxygen species (ROS) in apoptosis is unclear. The present studies tested the hypothesis that Rac1-mediated ROS production is involved in TNF-α-induced apoptosis. In this study, we showed that TNF-α/CHX-induced ROS production and hydrogen peroxide (H2O2)-induced oxidative stress increased apoptosis. Inhibition of Rac1 by a specific inhibitor NSC23766 prevented TNF-α-induced ROS production. The antioxidant, N-acetylcysteine (NAC), or rotenone (Rot), the mitochondrial electron transport chain inhibitor, attenuated mitochondrial ROS production and apoptosis. Rot also prevented JNK1/2 activation during apoptosis. Inhibition of Rac1 by expression of dominant negative Rac1 decreased TNF-α-induced mitochondrial ROS production. Moreover, TNF-α-induced cytosolic ROS production was inhibited by Rac1 inhibition, diphenyleneiodonium (DPI, an inhibitor of NADPH oxidase), and NAC. In addition, DPI inhibited TNF-α-induced apoptosis as judged by morphological changes, DNA fragmentation, and JNK1/2 activation. Mitochondrial membrane potential change is Rac1 or cytosolic ROS dependent. Lastly, all ROS inhibitors inhibited caspase-3 activity. Thus these results indicate that TNF-α-induced apoptosis requires Rac1-dependent ROS production in intestinal epithelial cells.
Sympathetic nerve activity in the superior cervical ganglia increases in response to imposed increases in arterial pressure
Authors: Cassaglia Priscila A. , Griffiths Robert I. , Walker Adrian M.
Published: January 2008

Sympathetic vasoconstriction of cerebral vessels has been proposed to be a protective mechanism for the brain, limiting cerebral perfusion and microcirculatory pressure during transient increases in arterial pressure. To furnish direct neural evidence for this proposition, we aimed to develop a method for recording cerebral sympathetic nerve activity (SNA) from the superior cervical ganglion (SCG). We hypothesized that SNA recorded from the SCG increases during imposed hypertension, but not during hypotension. Lambs ( n = 11) were anesthetized (α-chloralose, 20 mg·kg−1·h−1) and ventilated. SNA was measured using 25-μm tungsten microelectrodes inserted into the SCG. Arterial blood pressure (AP) was pharmacologically raised (adrenaline, phenylephrine, or ANG II, 1–50 μg/kg iv), mechanically raised (intravascular balloon in the thoracic aorta), or lowered (sodium nitroprusside, 1–50 μg/kg iv). In response to adrenaline ( n = 10), mean AP increased 135 ± 10% from baseline (mean ± SE), and the RMS value of SNA (Square Root of the Mean of the Squares, SNARMS) increased 255 ± 120%. In response to mechanically induced hypertension, mean AP increased 43 ± 3%, and SNARMS increased 53 ± 13%. Generally, (9 of 10 animals), SNARMS did not increase, as AP was lowered with sodium nitroprusside. Using a new model for direct recording of cerebral SNA from the SCG, we have demonstrated that SNA increases in response to large induced rises, but not falls, in AP. These findings furnish direct support for the proposed protective role for sympathetic nerves in the cerebral circulation.
Novel regulatory function for NHERF-1 in Npt2a transcription
Authors: Khundmiri Syed Jalal , Ahmad Aamir , Bennett Ryan Everett , Weinman Edward J. , Steplock Deborah , Cole Judith , Baumann Patrick D. , Lewis John , Singh Saurabh , Clark Barbara J. , Lederer Eleanor D.
Published: January 2008

Several lines of evidence show that sodium/hydrogen exchanger regulatory factor 1 (NHERF-1) regulates the expression and activity of the type IIa sodium-dependent phosphate transporter (Npt2a) in renal proximal tubules. We have previously demonstrated that expression of a COOH-terminal ezrin binding domain-deficient NHERF-1 in opossum kidney (OK) cells decreased expression of Npt2a in apical membranes but did not affect responses to parathyroid hormone. We hypothesized that NHERF-1 regulates apical membrane expression of Npt2a in renal proximal tubule cells. To address this hypothesis, we compared regulation of Npt2a expression and function in NHERF-deficient OK cells (OK-H) and wild-type cells (OK-WT). In OK-H cells, phosphate uptake and expression of Npt2a protein in apical membranes were significantly lower than in OK-WT cells. Transient transfection of green fluorescent protein-tagged Npt2a cDNA into OK-H cells resulted in aberrant localization of an Npt2a fragment to the cytosol but not to the apical membrane. OK-H cells also exhibited a marked decrease in Npt2a mRNA expression. As demonstrated by luciferase assay, Npt2a promoter activity was significantly decreased in OK-H cells compared with that shown in OK-WT cells. Transfection of OK-H cells with human NHERF-1 restored Npt2a expression at both the protein and mRNA levels and regulation by parathyroid hormone. Expression of NHERF-1 constructs with mutations in the PDZ domains or the ezrin binding domain in OK-H cells suggested that the PDZ2 domain is critical for apical translocation of Npt2a and for expression at the mRNA level. Our data demonstrate for the first time that NHERF-1 regulates Npt2a transcription and membrane insertion.
Pulmonary edema after competitive breath-hold diving
Authors: Linér Mats H. , Andersson Johan P. A.
Published: January 2008

During an international breath-hold diving competition, 19 of the participating divers volunteered for the present study, aimed at elucidating possible symptoms and signs of pulmonary edema after deep dives. Measurements included dynamic spirometry and pulse oximetry, and chest auscultation was performed on those with the most severe symptoms. After deep dives (25–75 m), 12 of the divers had signs of pulmonary edema. None had any symptoms or signs after shallow pool dives. For the whole group of 19 divers, average reductions in forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1) were −9 and −12%, respectively, after deep dives compared with after pool dives. In addition, the average reduction in arterial oxygen saturation (SaO2) was −4% after the deep dives. In six divers, respiratory symptoms (including dyspnea, cough, fatigue, substernal chest pain or discomfort, and hemoptysis) were associated with aggravated deteriorations in the physiological variables (FVC: −16%; FEV1: −27%; SaO2: −11%). This is the first study showing reduced spirometric performance and arterial hypoxemia as consequences of deep breath-hold diving, and we suggest that the observed changes are caused by diving-induced pulmonary edema. From the results of the present study, it must be concluded that the great depths reached by these elite apnea divers are associated with a risk of pulmonary edema.
The Effects of Microstimulation of the Dorsomedial Frontal Cortex on Saccade Latency
Authors: Yang Shun-nan , Heinen Stephen J. , Missal Marcus
Published: January 2008

Neural regions in the dorsomedial frontal cortex (DMFC), including the supplementary eye field (SEF) and the presupplementary motor area (pre-SMA), are likely candidates for generating top-down control of saccade target selection. To investigate this, we applied electrical microstimulation to these structures while saccades were being planned to visual targets. Stimulation administered to superficial and lateral DMFC sites that were within or close to the SEF delayed ipsilateral and facilitated contralateral saccades. Facilitation was limited to saccades made toward targets in a narrow, contralateral movement field that had endpoints consistent with the goal of evoked saccades. Facilitation occurred with current delivered before target onset and delay with current applied after this time. Stimulation at deeper, medial sites that encompassed the pre-SMA resulted in mostly bilateral delay. The amount of delay at these sites was usually greater for ipsilateral saccades and increased with current amplitude. Changes in saccade latency were not accompanied by altered endpoint, trajectory, or peak velocity. The spatial specificity of SEF stimulation in inducing latency changes suggests that the SEF participates in selecting saccade goals. The less specific delay with pre-SMA stimulation suggests that it is involved in postponing visually guided saccades, thus likely permitting other oculomotor structures to select saccade goals.
Differential Neurotrophic Regulation of Sodium and Calcium Channels in an Adult Sympathetic Neuron
Authors: Ford Christopher P. , Wong Kenneth V. , Lu Van B. , Posse de Chaves Elena , Smith Peter A.
Published: January 2008

Adult neuronal phenotype is maintained, at least in part, by the sensitivity of individual neurons to a specific selection of neurotrophic factors and the availability of such factors in the neurons' environment. Nerve growth factor (NGF) increases the functional expression of Na+channel currents ( INa) and both N- and L-type Ca2+currents ( ICa,Nand ICa,L) in adult bullfrog sympathetic ganglion (BFSG) B-neurons. The effects of NGF on ICainvolve the mitogen-activated protein kinase (MAPK) pathway. Prolonged exposure to the ganglionic neurotransmitter luteinizing hormone releasing hormone (LHRH) also increases ICa,Nbut the transduction mechanism remains to be elucidated as does the transduction mechanism for NGF regulation of Na+channels. We therefore exposed cultured BFSG B-neurons to chicken II LHRH (0.45 μM; 6–9 days) or to NGF (200 ng/ml; 9–10 days) and used whole cell recording, immunoblot analysis, and ras or rap-1 pulldown assays to study effects of various inhibitors and activators of transduction pathways. We found that 1) LHRH signals via ras-MAPK to increase ICa,N, 2) this effect is mediated via protein kinase C-β (PKC-β-ΙΙ), 3) protein kinase A (PKA) is necessary but not sufficient to effect transduction, 4) NGF signals via phosphatidylinositol 3-kinase (PI3K) to increase INa, and 5) long-term exposure to LHRH fails to affect INa. Thus downstream signaling from LHRH has access to the ras-MAPK pathway but not to the PI3K pathway. This allows for differential retrograde and anterograde neurotrophic regulation of sodium and calcium channels in an adult sympathetic neuron.
Level Dependence of Contextual Modulation in Auditory Cortex
Authors: Scholl Ben , Gao Xiang , Wehr Michael
Published: January 2008

Responses of cortical neurons to sensory stimuli within their receptive fields can be profoundly altered by the stimulus context. In visual and somatosensory cortex, contextual interactions have been shown to change sign from facilitation to suppression depending on stimulus strength. Contextual modulation of high-contrast stimuli tends to be suppressive, but for low-contrast stimuli tends to be facilitative. This trade-off may optimize contextual integration by cortical cells and has been suggested to be a general feature of cortical processing, but it remains unknown whether a similar phenomenon occurs in auditory cortex. Here we used whole cell and single-unit recordings to investigate how contextual interactions in auditory cortical neurons depend on the relative intensity of masker and probe stimuli in a two-tone stimulus paradigm. We tested the hypothesis that relatively low-level probes should show facilitation, whereas relatively high-level probes should show suppression. We found that contextual interactions were primarily suppressive across all probe levels, and that relatively low-level probes were subject to stronger suppression than high-level probes. These results were virtually identical for spiking and subthreshold responses. This suggests that, unlike visual cortical neurons, auditory cortical neurons show maximal suppression rather than facilitation for relatively weak stimuli.
The Effectiveness of “Two-Week” Referrals for Suspected Bone and Soft Tissue Sarcoma
Authors: Malik A. , Wigney L. , Murray S. , Gerrand C. H.
Published: January 2008

The two-week wait” target introduced in 2000 requires that patients with suspected cancer referred by general practitioners should be seen within two weeks. We reviewed patients who had been referred under this standard to the North of England Bone and Soft Tissue Tumour Service, to determine if the referral guidelines had been followed, and what proportion of patients referred under the guideline had malignant tumours. 40 patients were referred under the guideline between January 2004 and December 2005. Ten of these patients (2548%) had malignant tumours, compared with 243 of 507 (48%) of those referred from other sources. In 9 of the 40 cases, the patient did not meet the criteria for urgent referral. Although this target has focussed attention on shortening the time to diagnosis and treatment, prioritising patients referred from general practitioners has the potential to disadvantage those with malignant tumours referred from other sources.
Liquid‐Liquid Interfacial Transport of Nanoparticles
Authors: Machunsky Stefanie , Peuker Urs Alexander
Published: January 2008

The study presents the transfer of nanoparticles from the aqueous phase to the second nonmiscible nonaqueous liquid phase. The transfer is based on the sedimentation of the dispersed particles through a liquid‐liquid interface. First, the colloidal aqueous dispersion is destabilised to flocculate the particles. The agglomeration is reversible and the flocs are large enough to sediment in a centrifugal field. The aqueous dispersion is laminated above the receiving organic liquid phase. When the particles start to penetrate into the liquid‐liquid interface, the particle surface is covered with the stabilising surfactant. The sorption of the surfactant onto the surface of the primary particles leads to the disintegration of the flocs. This phase transfer process allows for a very low surfactant concentration within the receiving organic liquid, which is important for further application, that is, synthesis for polymer‐nanocomposite materials. Furthermore, the phase transfer of the nanoparticles shows a high efficiency up to 100% yield. The particle size within the organosol corresponds to the primary particle size of the nanoparticles.
High-Resolution Movement EEG Classification
Authors: Štastný Jakub , Sovka Pavel
Published: January 2008

The aim of the contribution is to analyze possibilities of high-resolution movement classification using human EEG. For this purpose, a database of the EEG recorded during right-thumb and little-finger fast flexion movements of the experimental subjects was created. The statistical analysis of the EEG was done on the subject's basis instead of the commonly used grand averaging. Statistically significant differences between the EEG accompanying movements of both fingers were found, extending the results of other so far published works. The classifier based on hidden Markov models was able to distinguish between movement and resting states (classification score of 94–100%), but it was unable to recognize the type of the movement. This is caused by the large fraction of other (nonmovement related) EEG activities in the recorded signals. A classification method based on advanced EEG signal denoising is being currently developed to overcome this problem.
Can Magnetic Monopoles and Massive Photons Coexist in the Framework of the Same Classical Theory?
Authors: Cafaro C. , Capozziello S. , Corda Ch. , Ali S. A.
Published: January 2008

It is well known that one cannot construct a self-consistent quantum field theory describing the nonrelativistic electromagnetic interaction mediated by massive photons between a point-like electric charge and a magnetic monopole. We show that, indeed, this inconsistency arises in the classical theory itself. No semiclassic approximation or limiting procedure forℏ→0is used. As a result, the string attached to the monopole emerges as visible also if finite-range electromagnetic interactions are considered in classical framework.
Mechanism of the Anti-inflammatory Effect of Curcumin: PPAR-γActivation
Authors: Jacob Asha , Wu Rongqian , Zhou Mian , Wang Ping
Published: January 2008

Curcumin, the phytochemical component in turmeric, is used as a dietary spice and a topical ointment for the treatment of inflammation in India for centuries. Curcumin (diferuloylmethane) is relatively insoluble in water, but dissolves in acetone, dimethylsulphoxide, and ethanol. Commercial grade curcumin contains 10–20% curcuminoids, desmethoxycurcumin, and bisdesmethoxycurcumin and they are as effective as pure curcumin. Based on a number of clinical studies in carcinogenesis, a daily oral dose of 3.6 g curcumin has been efficacious for colorectal cancer and advocates its advancement into Phase II clinical studies. In addition to the anticancer effects, curcumin has been effective against a variety of disease conditions in both in vitro and in vivo preclinical studies. The present review highlights the importance of curcumin as an anti-inflammatory agent and suggests that the beneficial effect of curcumin is mediated by the upregulation of peroxisome proliferator-activated receptor-γ(PPAR-γ) activation.
Provider Knowledge, Attitudes, and Practices regarding Obstetric and Postsurgical Gynecologic Infections Due to Group AStreptococcusand Other Infectious Agents
Authors: Van Beneden Chris A. , Hicks Lauri A. , Riley Laura E. , Schulkin Jay
Published: January 2008

Background. Knowledge, attitudes, and practices of obstetricians and gynecologists regarding the Centers for Disease Control and Prevention (CDC) recommendations for prevention of healthcare-associated group A streptococcal (GAS) infections as well as general management of pregnancy-related and postpartum infections are unknown.Methods. Questionnaires were sent to 1300 members of the American College of Obstetricians and Gynecologists.Results. Overall, 53% of providers responded. Postpartum and postsurgical infections occurred in 3% and 7% of patients, respectively. Only 14% of clinicians routinely obtain diagnostic specimens for postpartum infections; providers collecting specimens determined the microbial etiology in 28%. Microbiologic diagnoses were confirmed in 20% of postsurgical cases. Approximately 13% and 15% of postpartum and postsurgical infections for which diagnoses were confirmed were attributed to GAS, respectively. Over 70% of clinicians were unaware of CDC recommendations.Conclusions. Postpartum and postsurgical infections are common. Providing empiric treatment without attaining diagnostic cultures represents a missed opportunity for potential prevention of diseases such as severe GAS infections.
Composition Operators and Multiplication Operators on Weighted Spaces of Analytic Functions
Authors: Manhas J. S.
Published: January 2008

LetVbe an arbitrary system of weights on an open connected subsetGofℂN(N≥1)and letB(E)be the Banach algebra of all bounded linear operators on a Banach spaceE. LetHVb(G,E)andHV0(G,E)be the weighted locally convex spaces of vector-valued analytic functions. In this survey, we present a development of the theory of multiplication operators and composition operators from classical spaces of analytic functionsH(G)to the weighted spaces of analytic functionsHVb(G,E)andHV0(G,E).
On Some Analytic Functions Defined by a Multiplier Transformation
Authors: Noor Khalida Inayat
Published: January 2008

We introduce and study a new class of analytic functions defined in the unit disc using a certain multiplier transformation. Some inclusion results and other interesting properties of this class are investigated.
PPAR Gamma: Coordinating Metabolic and Immune Contributions to Female Fertility
Authors: Minge Cadence E. , Robker Rebecca L. , Norman Robert J.
Published: January 2008

Peroxisome proliferator‐activated receptor gamma (PPARG) regulates cellular functions such as adipogenesis and immune cell activation. However, new information has indicated additional roles of PPARG directing the cyclic changes that occur within ovarian tissue of female mammals, including those that facilitate the release of oocytes each estrous cycle. In addition to ovarian PPARG expression and function, many PPARG actions within adipocytes and macrophages have additional direct and indirect implications for ovarian function and female fertility. This encompasses the regulation of lipid uptake and transport, insulin sensitivity, glucose metabolism, and the regulation of inflammatory mediator synthesis and release. This review discusses the developing links between PPARG activity and female reproductive function, and highlights several mechanisms that may facilitate such a relationship.
Placental Implications of Peroxisome Proliferator‐Activated Receptors in Gestation and Parturition
Authors: Borel Valerie , Gallot Denis , Marceau Geoffroy , Sapin Vincent , Blanchon Loïc
Published: January 2008

The placenta is a transitory structure indispensable for the proper development of the embryo and fetus during mammalian gestation. Like other members of the nuclear receptor family, the peroxisome proliferator‐activated receptors
(PPARs) are known to be involved in the physiological and pathological events occurring during the placentation.
This placental involvement has been recently reviewed focusing on the early stages of placental development (implantation and invasion, etc.), mouse PPARs knockout phenotypes, and cytotrophoblast physiology. In this
review, we describe the placental involvement of PPARs (e.g., fat transport and metabolism, etc.) during the late stages of
gestation and in the amniotic membranes, highlighting their roles in the inflammation process (e.g., chorioamnionitis), metabolic disorders (e.g., diabetes), and parturition.
On Fault Detection in Linear Discrete‐Time, Periodic, and Sampled‐Data Systems
Authors: Zhang P. , Ding S. X.
Published: January 2008

This paper gives a review of some standard fault‐detection (FD) problem
formulations in discrete linear time‐invariant systems and the available solutions. Based on it, recent development of FD in periodic systems and sampled‐data systems is reviewed and presented. The focus in this paper is on the robustness and sensitivity issues in designing model‐based FD systems.
Reflection and Transmission of Micropolar Elastic Waves at an Imperfect Boundary
Authors: Kumar Rajneesh , Sharma Nidhi , Ram Paras
Published: January 2008

A problem concerning with the reflection and transmission of micropolar elastic plane waves at an imperfect interface between two homogeneous, isotropic micropolar elastic half‐spaces of different micropolar elastic properties has been investigated. The expressions for the reflection and transmission coefficients which are the ratios of the amplitudes of reflected and transmitted waves to the amplitude of incident waves are obtained for an imperfect boundary and deduced for normal couple stiffness, transverse couple stiffness, transverse force stiffness and welded contact. Numerical calculations have been performed for amplitude ratios of various reflected and transmitted waves. The variations of amplitude ratios with angle of incident wave have been depicted graphically. Some special cases have also been deduced from the present investigation. It is found that the amplitude ratios of reflected and transmitted waves are affected by the stiffness and micropolarity of the media.
Temperature Distribution Modeling of Friction Stir Spot Welding of AA 6061‐T6 Using Finite Element Technique
Authors: Sathiya P. , Siva Shanmugam N. , Ramesh T. , Murugavel R.
Published: January 2008

Friction stir welding (FSW), a process that involves joining of metals without fusion of filler materials. It is used already in routine, as well as critical application for the joining of structural components made of Aluminum and its alloys. Indeed it has been convincingly demonstrated that the process results in strong and ductile joints, some times in systems, which have proved difficult using conventional welding techniques. The process is most suitable for components that are flat & long (plates & sheets) but it can be adapted for pipes, hollow sections and positional welding. The welds are created by the combined action of frictional heating and mechanical deformation, due to a rotating tool. Recently, a new technology called friction stir spot welding (FSSW) has been developed that has a several advantages over the electric resistance welding process widely used in automotive industry in terms of weld quality and process efficiency. This welding technology involves a process similar to FSW, except that, instead of moving the tool along the weld seam, the tool only indents the parts, which are placed on top of each other. The conditions under which the deposition process in FSSW is successful are not fully understood. However, it is known that only under specific thermo‐mechanical conditions does a weld formation occur. The objective of the present work is to analyze the primary conditions under which the cavity behind the tool is filled. For this, a fully coupled thermo‐mechanical three‐dimensional FE model has been developed in ABAQUS/Explicit using the adaptive meshing scheme and the Johnson‐Cook material law. The contact forces are modeled by Coulomb’s law of friction, making the contact condition highly solution dependent. Temperature graph in the radial direction as well as stress, strain plots are presented.
Modeling of Deformations of Photolithographic Objects
Authors: Touati A. , Corbel S. , Corriou J.P.
Published: January 2008

Photolithography allows the fabrication of a solid polymer object through polymerization of a monomer resin by means of a laser source guided according to the data of computer aided design. However, one drawback of this method is the inaccuracy of the dimensions of the objects related to the shrinkage phenomenon which depends on the polymerization, on the laser flux and on the used sweeping procedure. In this paper, the deformation of an isolated voxel (elementary volume) or a voxel interacting with its neighbor is described. This simulation is based on a kinetic model that takes into account the gel effect and a model of volumetric variation due to the difference of the length of the bonds between the monomer and polymer molecules.
Estimating Rain Rates from Tipping-Bucket Rain Gauge Measurements
Authors: Wang Jianxin , Fisher Brad L. , Wolff David B.
Published: January 2008

This paper describes the cubic spline–based operational system for the generation of the Tropical Rainfall Measuring Mission (TRMM) 1-min rain-rate product 2A-56 from tipping-bucket (TB) gauge measurements. A simulated TB gauge from a Joss–Waldvogel disdrometer is employed to evaluate the errors of the TB rain-rate estimation. These errors are very sensitive to the time scale of rain rates. One-minute rain rates suffer substantial errors, especially at low rain rates. When 1-min rain rates are averaged over 4–7-min intervals or longer, the errors dramatically reduce. Estimated lower rain rates are sensitive to the event definition whereas the higher rates are not. The median relative absolute errors are about 22% and 32% for 1-min rain rates higher and lower than 3 mm h−1, respectively. These errors decrease to 5% and 14% when rain rates are used at the 7-min scale. The radar reflectivity–rain-rate distributions drawn from the large amount of 7-min rain rates and radar reflectivity data are mostly insensitive to the event definition. The time shift due to inaccurate clocks can also cause rain-rate estimation errors, which increase with the shifted time length. Finally, some recommendations are proposed for possible improvements of rainfall measurements and rain-rate estimations.
Housing Aspirations of Southern Appalachian Families1
Authors: Montgomery James E. , McCabe Gracia S.
Published: January 2008

The purposes of this study were to: (1) characterize specific dimensions of life styles in Southern Appalachia, (2) describe current housing conditions, and (3) examine housing aspirations of samples of rural and urban families of the region. In 1969 interviews were conducted with 274 rural and 227 urban families who lived in low‐income areas of Southwest Virginia. In the analysis, answers to questions developed around 10 housing characteristics were used to construct a suburban modern/mountain traditional summed scale. Findings suggest that for the most part the mountain respondents desired new or relatively new single‐family houses with modern equipment, quite similar to houses desired by mainstream Americans. We concluded that the respondents had relatively high aspirations but that implementation had been constrained by low income and lack of education.
Relationship of Decision Styles and Self‐Actualization1
Authors: Price Dorothy Z.
Published: January 2008

This study focused on exploration of a possible relationship between psychological health (as measured by level of self‐actualization) and the actual style involved in decision making. Forty three‐member family groups were studied, using questionnaires and tape recordings, while they were involved in a simulated family situation, including three separate decision situations. Examination of the results suggested the existence of two separate decision styles: a traditional approach which appeared to be utilized by “normal” and low self‐actualizing people, and a second approach which was utilized by those who ranked high in self‐actualization scores. The decision styles utilized indicated that more attention should be paid, in all decision groups, to the effects of decision making on the individuals involved. It may be that decision‐making style can, in itself, have a positive or negative effect on individual growth and development, and may offer a way for families to foster growth of all individuals while simultaneously solving specific problems.
Manifest Anxiety in Economically Deprived Children in Rural Appalachia
Authors: Southworth Lois E. , Albert Zoe E. , Gravatt Arthur E.
Published: January 2008

The purposes of this study were to obtain data on the Children's Manifest Anxiety Scale (CMAS) administered to children in an Appalachian area, to compare these data with appropriate studies reported in the literature for other groups of children in the United States, and to discuss results in terms of child‐rearing practices.

The CMAS was administered to 176 fifth and sixth grade children from families of low socioeconomic level in a rural Appalachian area of East Tennessee. Mean scores were higher than for most groups of middle‐class Midwest children reported in the literature, especially for fifth grade girls, but were commensurate with reported scores of children from a Southeastern area, black children, and a psychiatric outpatient group in Minnesota. Results of an item analysis and chi‐square analysis of sex differences were compared with a St. Louis study. Findings are discussed in terms of child‐rearing practices in Appalachia since reports of cross‐cultural CMAS studies have stressed this aspect when reporting comparative data.
Neutrophil-selective CD18 silencing using RNA interference in vivo
Authors: Cullere Xavier , Lauterbach Michael , Tsuboi Naotake , Mayadas Tanya N.
Published: January 2008

Tissue-specific silencing of genes may be used for genetic engineering in mice and has possible therapeutic applications in humans. Current strategies in mice rely on Cre/loxP technology requiring the generation of multiple transgenic lines and breeding strategies. Here, we describe the selective silencing of CD18, a leukocyte-specific integrin in neutrophils using a micro RNA (miRNA) strategy that requires the generation of one transgenic line. CD18-specific miRNA hairpin driven by the myeloid specific human MRP8 promoter resulted in the generation of transgenic lines with 75% to 95% reduction in CD18 protein levels in neutrophils and monocytes. Minimal decreases in T cells and a partial diminution in macrophages were observed. Neutrophil CD18 silencing resulted in neutrophilia, splenomegaly, and significant defects in neutrophil trafficking with the degree of alterations correlating with the extent of CD18 silencing. Thus, our data demonstrate the utility of using miRNA approaches to silence genes in neutrophils, which are terminally differentiated cells with a short half-life that largely precludes their genetic manipulation in vitro. Furthermore, the mouse models provide a valuable tool to examine the contribution of CD18 on neutrophils to leukocyte adhesion deficiency type I (LAD-I), a complex inherited disorder in which reduced or absent CD18 expression in multiple leukocyte subsets leads to impaired innate and adaptive immune responses.
Specific regions within the embryonic midbrain and cerebellum require different levels of FGF signaling during development
Authors: Basson M. Albert , Echevarria Diego , Petersen Ahn Christina , Sudarov Anamaria , Joyner Alexandra L. , Mason Ivor J. , Martinez Salvador , Martin Gail R.
Published: January 2008

Prospective midbrain and cerebellum formation are coordinated by FGF ligands produced by the isthmic organizer. Previous studies have suggested that midbrain and cerebellum development require different levels of FGF signaling. However, little is known about the extent to which specific regions within these two parts of the brain differ in their requirement for FGF signaling during embryogenesis. Here, we have explored the effects of inhibiting FGF signaling within the embryonic mouse midbrain (mesencephalon)and cerebellum (rhombomere 1) by misexpressing sprouty2 (Spry2) from an early stage. We show that such Spry2 misexpression moderately reduces FGF signaling, and that this reduction causes cell death in the anterior mesencephalon, the region furthest from the source of FGF ligands. Interestingly, the remaining mesencephalon cells develop into anterior midbrain, indicating that a low level of FGF signaling is sufficient to promote only anterior midbrain development. Spry2 misexpression also affects development of the vermis, the part of the cerebellum that spans the midline. We found that, whereas misexpression of Spry2 alone caused loss of the anterior vermis, reducing FGF signaling further, by decreasing Fgf8 gene dose, resulted in loss of the entire vermis. Our data suggest that cell death is not responsible for vermis loss, but rather that it fails to develop because reducing FGF signaling perturbs the balance between vermis and roof plate development in rhombomere 1. We suggest a molecular explanation for this phenomenon by providing evidence that FGF signaling functions to inhibit the BMP signaling that promotes roof plate development.
AKT signaling promotes derivation of embryonic germ cells from primordial germ cells
Authors: Kimura Tohru , Tomooka Maya , Yamano Noriko , Murayama Kazushige , Matoba Shogo , Umehara Hiroki , Kanai Yoshiakira , Nakano Toru
Published: January 2008

Primordial germ cells (PGCs) are embryonic germ cell precursors. Although the developmental potency of PGCs is restricted to the germ lineage, PGCs can acquire pluripotency, as verified by the in vitro establishment of embryonic germ (EG) cells and the in vivo production of testicular teratomas. PGC-specific inactivation of PTEN, which is a lipid phosphatase antagonizing phosphoinositide-3 kinase (PI3K), enhances both EG cell production and testicular teratoma formation. Here, we analyzed the effect of the serine/threonine kinase AKT, one of the major downstream effectors of PI3K, on the developmental potency of PGCs. We used transgenic mice that expressed an AKT-MER fusion protein, the kinase activity of which could be regulated by the ligand of modified estrogen receptor (MER), 4-hydroxytamoxifen. We found that hyperactivation of AKT signaling in PGCs at the proliferative phase dramatically augmented the efficiency of EG cell establishment. Furthermore,AKT signaling activation substituted to some extent for the effects of bFGF,an essential growth factor for EG cell establishment. By contrast, AKT activation had no effect on germ cells that were in mitotic arrest or that began meiosis at a later embryonic stage. In the transgenic PGCs, AKT activation induced phosphorylation of GSK3, which inhibits its kinase activity; enhanced the stability and nuclear localization of MDM2; and suppressed p53 phosphorylation, which is required for its activation. The p53 deficiency, but not GSK3 inhibition, recapitulated the effects of AKT hyperactivation on EG cell derivation, suggesting that p53 is one of the crucial downstream targets of the PI3K/AKT signal and that GSK3 is not.
Cytokinins induce sporulation inDictyostelium
Authors: Anjard Christophe , Loomis William F.
Published: January 2008

The social amoeba Dictyostelium discoideum diverged from the line leading to animals shortly after the separation of plants and animals but it retained characteristics of both kingdoms. A GABAB-like receptor and a peptide, SDF-2, with homologs found only in animals, control sporulation, while cytokinins, which act as hormones in plants, keep spores dormant. When SDF-2 binds its receptor DhkA, it reduces the activity of the cAMP phosphodiesterase RegA such that cAMP levels can increase. It has been proposed that the cytokinin discadenine also produces in an increase in cAMP but acts through a different histidine kinase, DhkB. We have found that discadenine and its precursor, isopentenyl adenine, not only maintain spore dormancy but also initiate rapid encapsulation independently of the SDF-2 signal transduction pathway. DhkB and the adenylyl cyclase of late development, AcrA, are members of two component signal transduction families and both are required to transduce the cytokinin signal. As expected, strains lacking the isopentenyl-transferase enzyme chiefly responsible for cytokinin synthesis are defective in sporulation. It appears that SDF-2 and cytokinins are secreted during late development to trigger signal transduction pathways that lead to an increase in the activity of the camp-dependent protein kinase,PKA, which triggers rapid encapsulation as well as ensuring spore dormancy.
Reducing Diagnostic Errors in Musculoskeletal Trauma by Reviewing Non-Admission Orthopaedic Referrals in the Next-Day Trauma Meeting
Authors: Sharma H , Bhagat S , Gaine WJ
Published: January 2008

INTRODUCTION

Diagnostic errors in orthopaedics are usually caused by missing a fracture or misreading radiographs. The aim of this study was to document the pick-up rate of the wrong diagnoses by reviewing X-rays and casualty notes in the next-day trauma meeting.

PATIENTS AND METHODS

The casualty notes and radiographs of 503 patients were prospectively reviewed in the daily trauma meeting between August 2002 and December 2002 in a district general hospital. The relevant data were collected and analysed by a single assessor.

RESULTS

The false positive rate for making an orthopaedic diagnosis was 12.6% (i.e.) diagnosing a fracture, when none existed). The false negative (missing) rate was 4%, while 2.4% incidental findings were missed, or at least not documented, after reading the X-rays. There were 7.8% wrong diagnoses made. The majority of the patients were seen by the senior house officers.

CONCLUSIONS

The medicolegal significance of false negative diagnosis is obviously greater. In a busy emergency department, where a large number of patients are seen, there is a greater risk. This study shows the importance in a small-to-medium sized accident and emergency unit as well, where there is no senior cover available out-of-hours for final radiological interpretation. A morning trauma meeting which covers reviewing admitted patients as well as non-admission orthopaedic referrals has an effective risk management solution to early detection of missed and wrong diagnoses.