bluuebunny/crossref_metadata_2025 huggingface dataset:
The Trace Metal Composition of Marine Phytoplankton
Authors: Twining Benjamin S. , Baines Stephen B.
Published: August 2012

Trace metals are required for numerous processes in phytoplankton and can influence the growth and structure of natural phytoplankton communities. The metal contents of phytoplankton reflect biochemical demands as well as environmental availability and influence the distribution of metals in the ocean. Metal quotas of natural populations can be assessed from analyses of individual cells or bulk particle assemblages or inferred from ratios of dissolved metals and macronutrients in the water column. Here, we review the available data from these approaches for temperate, equatorial, and Antarctic waters in the Pacific and Atlantic Oceans. The data show a generalized metal abundance ranking of Fe≈Zn>Mn≈Ni≈Cu≫Co≈Cd; however, there are notable differences between taxa and regions that inform our understanding of ocean metal biogeochemistry. Differences in the quotas estimated by the various techniques also provide information on metal behavior. Therefore, valuable information is lost when a single metal stoichiometry is assumed for all phytoplankton.
SSTR2 is the functionally dominant somatostatin receptor in human pancreatic β- and α-cells
Authors: Kailey Balrik , van de Bunt Martijn , Cheley Stephen , Johnson Paul R. , MacDonald Patrick E. , Gloyn Anna L. , Rorsman Patrik , Braun Matthias
Published: August 2012

Somatostatin-14 (SST) inhibits insulin and glucagon secretion by activating G protein-coupled somatostatin receptors (SSTRs), of which five isoforms exist (SSTR1–5). In mice, the effects on pancreatic β-cells are mediated by SSTR5, whereas α-cells express SSTR2. In both cell types, SSTR activation results in membrane hyperpolarization and suppression of exocytosis. Here, we examined the mechanisms by which SST inhibits secretion from human β- and α-cells and the SSTR isoforms mediating these effects. Quantitative PCR revealed high expression of SSTR2, with lower levels of SSTR1, SSTR3, and SSTR5, in human islets. Immunohistochemistry showed expression of SSTR2 in both β- and α-cells. SST application hyperpolarized human β-cells and inhibited action potential firing. The membrane hyperpolarization was unaffected by tolbutamide but antagonized by tertiapin-Q, a blocker of G protein-gated inwardly rectifying K+ channels (GIRK). The effect of SST was mimicked by an SSTR2-selective agonist, whereas a SSTR5 agonist was marginally effective. SST strongly (>70%) reduced depolarization-evoked exocytosis in both β- and α-cells. A slightly weaker inhibition was observed in both cell types after SSTR2 activation. SSTR3- and SSTR1-selective agonists moderately reduced the exocytotic responses in β- and α-cells, respectively, whereas SSTR4- and SSTR5-specific agonists were ineffective. SST also reduced voltage-gated P/Q-type Ca2+ currents in β-cells, but normalization of Ca2+ influx to control levels by prolonged depolarizations only partially restored exocytosis. We conclude that SST inhibits secretion from both human β- and α-cells by activating GIRK and suppressing electrical activity, reducing P/Q-type Ca2+ currents, and directly inhibiting exocytosis. These effects are mediated predominantly by SSTR2 in both cell types.
β-Adrenergic receptor stimulation increases surface NKCC2 expression in rat thick ascending limbs in a process inhibited by phosphodiesterase 4
Authors: Haque Mohammed Z. , Caceres Paulo S. , Ortiz Pablo A.
Published: August 2012

The thick ascending limb of the loop of Henle (THAL) reabsorbs ∼30% of the filtered NaCl in a process mediated by the apical Na-K-2Cl cotransporter NKCC2. Stimulation of β-adrenergic receptors in the THAL enhances NaCl reabsorption and increases intracellular cAMP. We found that intracellular cAMP stimulates NKCC2 trafficking to the apical membrane via protein kinase A (PKA). Several cAMP-specific phosphodiesterases (PDE) have been identified in rat THALs, and PDE4 decreases cAMP generated by β-adrenergic stimulation in other cells. However, it is not known whether β-adrenergic receptors activation stimulates NKCC2 trafficking. Thus we hypothesized that β-adrenergic receptor stimulation enhances THAL apical membrane NKCC2 expression via the PKA pathway and PDE4 blunts this effect. THAL suspensions were obtained from Sprague-Dawley rats, and surface NKCC2 expression was measured by surface biotinylation and Western blot. Incubation of THALs with the β-adrenergic receptor agonist isoproterenol at 0.5 and 1.0 μM increased surface NKCC2 by 17 ± 1 and 29 ± 5% respectively ( P < 0.05). Preventing cAMP degradation with 3-isobutyl-methylxanthine (IBMX; a nonselective phosphodiesterase inhibitor) enhanced isoproterenol-stimulated surface NKCC2 expression to 51 ± 7% ( P < 0.05 vs. isoproterenol). The β-adrenergic receptor antagonist propranolol or the PKA inhibitor H-89 completely blocked isoproterenol + IBMX-induced increase on surface NKCC2, while propranolol or H-89 alone had no effect. Selective inhibition of PDE4 with rolipram (20 μM) potentiated the effect of isoproterenol on surface NKCC2 and increased cAMP levels. We concluded that β-adrenergic receptor stimulation enhances surface NKCC2 expression in the THALs via PKA and PDE4 blunts this effect.
Motor learning reveals the existence of multiple codes for movement planning
Authors: Hudson Todd E. , Landy Michael S.
Published: August 2012

Coordinate systems for movement planning are comprised of an anchor point (e.g., retinocentric coordinates) and a representation (encoding) of the desired movement. One of two representations is often assumed: a final-position code describing desired limb endpoint position and a vector code describing movement direction and extent. The existence of movement-planning systems using both representations is controversial. In our experiments, participants completed reaches grouped by target location (providing practice for a final-position code) and the same reaches grouped by movement vector (providing vector-code practice). Target-grouped reaches resulted in the isotropic (circular) distribution of errors predicted for position-coded reaches. The identical reaches grouped by vector resulted in error ellipses aligned with the reach direction, as predicted for vector-coded reaches. Manipulating only recent movement history to provide better learning for one or the other movement code, we provide definitive evidence that both movement representations are used in the identical task.
Fungal Infections: Their Diagnosis and Treatment in Transplant Recipients
Authors: Van Thiel David H. , George Magdalena , Moore Christopher M.
Published: August 2012

Systemic fungal infections typically occur in individuals who are seriously ill with recognized risk factors such as those frequently found in transplant recipients. Unfortunately, they are often diagnosed late, when the efficacy of the available treatments is low, often less than 50%, and the cost in terms of lives lost, hospital length of stay, and total hospital costs is substantially increased. The application of antifungal therapies associated with reported efficacy rates greater than 50% are those used prophylactically. When used prophylactically, these infections are reduced in greater than 95% of the expected cases. The choice of a prophylactic agent should be based upon its ease of administration, lack of adverse effects, reduced likelihood of potential drug interactions, and its efficacy in patients with established risk factors and comorbid disease processes that include renal, hepatic, and chronic pulmonary disease. The indications for the use of currently available antifungal agents, their adverse effects, drug interactions, ease of dosing, and applicability in patients with preexisting disease states, and especially in liver transplant recipients, are presented in this paper.
A Volume-Surface Integral Equation Solver for Radiation from Microstrip Antenna on Anisotropic Substrate
Authors: Ye Yuhuang , Yuan Jiade , Su Kaixiong
Published: August 2012

A volume-surface integral equation (VSIE) solver is presented for the calculation of electromagnetic radiation from arbitrary shaped microstrip antenna on anisotropic substrate. The method of moments (MoM) is used to convert the integral equation into a matrix equation, where the equivalent volume current and surface current are expanded into a finite series of SWG and RWG basis function, respectively. A simple strip model is incorporated in the VSIE to simplify the analysis of the probe-fed microstrip antenna. The present approach is sufficiently versatile in handling microstrip antenna with arbitrary shaped anisotropic dielectric substrate. Numerical results indicate the reliability and accuracy of the proposed method.
Management of Climatic Factors for Successful Silkworm (Bombyx moriL.) Crop and Higher Silk Production: A Review
Authors: Rahmathulla V. K.
Published: August 2012

The seasonal differences in the environmental components considerably affect the genotypic expression in the form of phenotypic output of silkworm crop such as cocoon weight, shell weight, and cocoon shell ratio. The variations in the environmental conditions day to day and season to season emphasize the need of management of temperature and relative humidity for sustainable cocoon production. The present review paper discuss in details about the role of temperature and humidity on growth and development of silkworm including recent studies on heat shock protein. Study also discusses the influence of air and light on silkworm development. In addition to this study emphasis on the role of various environmental factors on embryonic development of silkworm egg, nutritional indices of silkworm larva and reproductive potential of silkworm moth. The study also highlights about the care to be required during silkworm spinning and influence of temperature and humidity on post cocoon parameters of silkworm. The study included future strategies to be taken for the management climatic condition for successful cocoon crop. The paper covers 140 references connected with the topic.
Genetic Associations in Acquired Immune-Mediated Bone Marrow Failure Syndromes: Insights in Aplastic Anemia and Chronic Idiopathic Neutropenia
Authors: Mavroudi Irene , Papadaki Helen A.
Published: August 2012

Increasing interest on the field of autoimmune diseases has unveiled a plethora of genetic factors that predispose to these diseases. However, in immune-mediated bone marrow failure syndromes, such as acquired aplastic anemia and chronic idiopathic neutropenia, in which the pathophysiology results from a myelosuppressive bone marrow microenvironment mainly due to the presence of activated T lymphocytes, leading to the accelerated apoptotic death of the hematopoietic stem and progenitor cells, such genetic associations have been very limited. Various alleles and haplotypes of human leucocyte antigen (HLA) molecules have been implicated in the predisposition of developing the above diseases, as well as polymorphisms of inhibitory cytokines such as interferon-γ, tumor necrosis factor-α, and transforming growth factor-β1 along with polymorphisms on molecules of the immune system including the T-bet transcription factor and signal transducers and activators of transcription. In some cases, specific polymorphisms have been implicated in the outcome of treatment on those patients.
Autopsy Findings in Conjoined Twin with Single Heart and Single Liver
Authors: Asaranti Kar , Pranati Mohanty , Tushar Kar , Jagadish Behera , Susmita Behera , Amarendra Nayak
Published: August 2012

Thoracoomphalopagus is the commonest type of conjoined twin where the bodies are fused from upper chest to lower chest. The autopsy done can help counsil the parents for further pregnancies and determine the prognosis depending upon the type of cardiac anomaly by Seo classification when detected antenatally. We describe the detail pathological autopsy of such a case with single heart and single liver. A detail autopsy was done on the twin fetus. The twins shared a single heart and sometimes the liver and part of digestive system. The combined weight was 4.1 KG. Both were full-term male babies joined from below the nipple till umbilicus. Autopsy in conjoined twins helps in deciding the type of fusion of the body and also of the heart and great vessels. It can help in counseling parents about future pregnancies that there is no chance of recurrence of this abnormality and no need to be scared.
An Iterative Algorithm for the Generalized Reflexive Solutions of the Generalized Coupled Sylvester Matrix Equations
Authors: Yin Feng , Huang Guang-Xin
Published: August 2012

An iterative algorithm is constructed to solve the generalized coupled Sylvester matrix equations (AXB − CYD, EXF − GYH) = (M, N), which includes Sylvester and Lyapunov matrix equations as special cases, over generalized reflexive matrices X and Y. When the matrix equations are consistent, for any initial generalized reflexive matrix pair [X1, Y1], the generalized reflexive solutions can be obtained by the iterative algorithm within finite iterative steps in the absence of round‐off errors, and the least Frobenius norm generalized reflexive solutions can be obtained by choosing a special kind of initial matrix pair. The unique optimal approximation generalized reflexive solution pair to a given matrix pair [X0, Y0] in Frobenius norm can be derived by finding the least‐norm generalized reflexive solution pair of a new corresponding generalized coupled Sylvester matrix equation pair , where . Several numerical examples are given to show the effectiveness of the presented iterative algorithm.
Interference of Selected Palmer Amaranth (Amaranthus palmeri) Biotypes in Soybean (Glycine max)
Authors: Chandi Aman , Jordan David L. , York Alan C. , Milla-Lewis Susana R. , Burton James D. , Culpepper A. Stanley , Whitaker Jared R.
Published: August 2012

Palmer amaranth (Amaranthus palmeriS. Wats.) has become difficult to control in row crops due to selection for biotypes that are no longer controlled by acetolactate synthase inhibiting herbicides and/or glyphosate. Early season interference in soybean [Glycine max(L.) Merr.] for 40 days after emergence by three glyphosate-resistant (GR) and three glyphosate-susceptible (GS) Palmer amaranth biotypes from Georgia and North Carolina was compared in the greenhouse. A field experiment over 2 years compared season-long interference of these biotypes in soybean. The six Palmer amaranth biotypes reduced soybean height similarly in the greenhouse but did not affect soybean height in the field. Reduction in soybean fresh weight and dry weight in the greenhouse; and soybean yield in the field varied by Palmer amaranth biotypes. Soybean yield was reduced 21% by Palmer amaranth at the established field density of 0.37 plant m−2. When Palmer amaranth biotypes were grouped by response to glyphosate, the GS group reduced fresh weight, dry weight, and yield of soybean more than the GR group. The results indicate a possible small competitive disadvantage associated with glyphosate resistance, but observed differences among biotypes might also be associated with characteristics within and among biotypes other than glyphosate resistance.
Xenograft Enriched with Autologous Bone Marrow in Inlay Reconstructions: A Tomographic and Histomorphometric Study in Rabbit Calvaria
Authors: de Oliveira e Silva Marcelo , Pelegrine André Antonio , Alves Pinheiro da Silva Alexandre , Manhães Júnior Luiz Roberto , de Mello e Oliveira Rafael , Gaiba França Silvana , Aloise Antonio Carlos , Ferreira Lydia Masako
Published: August 2012

Objective. The aim of this study was to evaluate the bone healing after the usage of a scaffold enriched with bone marrow.Study Design. Ten rabbits were divided into 2 groups of 5 animals. Bilateral 12 mm diameter defects were created in the parietal bones. In control group Bio-Oss were inserted in both defects and, in experimental group, Bio-Oss enriched with autologous bone marrow were inserted in both defects. In these two groups, one of the calvarial defects was covered with Bio-Gide. The rabbits were sacrified 8 weeks after surgery and both CT and histomorphometric analysis were done.Results. The CT showed a lower remaining defect area in the experimental group covered with Bio-Gide when compared with control group, with and without Bio-Gide. The histomorphometrics showed no difference between groups regarding the non-vital mineralized tissue area. For vital mineralized tissue area, the experimental group covered with Bio-Gide obtained a higher percentage area when compared with control group, with and without Bio-Gide. For non-mineralized tissue area, the experimental group covered with Bio-Gide obtained a lower percentage area when compared with control group, with and without Bio-Gide.Conclusion. Both autologous bone marrow and membrane can contribute to the enhancement of bone healing.
A Note on the Regularity Criterion of Weak Solutions of Navier‐Stokes Equations in Lorentz Space
Authors: Yin Xunwu
Published: August 2012

This paper is concerned with the regularity of Leray weak solutions to the 3D Navier‐Stokes equations in Lorentz space. It is proved that the weak solution is regular if the horizontal velocity denoted by satisfies The result is obvious and improved that of Dong and Chen (2008) on the Lebesgue space.
Effect of Minor Alloying Elements on the Corrosion Behavior of Fe40Al in NaCl-KCl Molten Salts
Authors: Salinas G. , Gonzalez-Rodriguez J. G. , Porcayo-Calderon J. , Salinas-Bravo V. M. , Espinoza-Medina M. A.
Published: August 2012

The hot corrosion behavior of Fe40Al intermetallic alloyed with Ag, Cu, Li, and Ni (1–5 at.%) in NaCl-KCl (1 : 1 M) at 670°C, typical of waste gasification environments, has been evaluated by using polarization curves and weight loss techniques and compared with a 304-type stainless steel. Both gravimetric and electrochemical techniques showed that all different Fe40Al-base alloys have a much higher corrosion resistance than that for stainless steel. Among the different Fe40Al-based alloys, the corrosion rate was very similar among each other, but it was evident that the addition of Li decreased their corrosion rate whereas all the other elements increased it. Results have been explained in terms of the formation and stability of an external, protective Al2O3layer.
The Relationship between Secondary Structure and Biodegradation Behavior of Silk Fibroin Scaffolds
Authors: Hu Yongpei , Zhang Qin , You Renchuan , Wang Lingshuang , Li Mingzhong
Published: August 2012

Silk fibroin has a unique and useful combination of properties, including good biocompatibility and excellent mechanical performance. These features provided early clues to the utility of regenerated silk fibroin as a scaffold/matrix for tissue engineering. The silk fibroin scaffolds used for tissue engineering should degrade at a rate that matches the tissue growth rate. The relationship between secondary structure and biodegradation behavior of silk fibroin scaffolds was investigated in this study. Scaffolds with different secondary structure were prepared by controlling the freezing temperature and by treatment with carbodiimide or ethanol. The quantitative proportions of each secondary structure were obtained by Fourier transform infrared spectroscopy (FTIR), and each sample was then degradedin vitrowith collagenase IA for 18 days. The results show that a high content ofβ-sheet structure leads to a low degradation rate. The random coil region in the silk fibroin material is degraded, whereas the crystal region remains stable and the amount ofβ-sheet structure increases during incubation. The results demonstrate that it is possible to control the degradation rate of a silk fibroin scaffold by controlling the content ofβ-sheet structure.
Activation Detection on fMRI Time Series Using Hidden Markov Model
Authors: Duan Rong , Man Hong
Published: August 2012

This paper introduces two unsupervised learning methods for analyzing functional magnetic resonance imaging (fMRI) data
based on hidden Markov model (HMM). HMM approach is focused on capturing the first-order statistical evolution among the samples of a voxel time series, and it can provide a complimentary perspective of the BOLD signals. Two-state HMM is created for each voxel, and the model parameters are estimated from the voxel time series and the stimulus paradigm. Two different activation detection methods are presented in this paper. The first method is based on the likelihood and likelihood-ratio test, in which an additional Gaussian model is used to enhance the contrast of the HMM likelihood map. The second method is based on certain distance measures between the two state distributions, in which the most likely HMM state sequence is estimated through the Viterbi algorithm. The distance between the on-state and off-state distributions is measured either through a t-test, or using the Kullback-Leibler distance (KLD). Experimental results on both normal subject and brain tumor subject are presented. HMM approach appears to be more robust in detecting the supplemental active voxels comparing with SPM, especially for brain tumor subject.
Predictors of Immunosuppressive Regulatory T Lymphocytes in Healthy Women
Authors: Hampras Shalaka S. , Nesline Mary , Wallace Paul K. , Odunsi Kunle , Furlani Nicholas , Davis Warren , Moysich Kirsten B.
Published: August 2012

Immunosuppressive regulatory T (Treg) cells play an important role in antitumor immunity, self-tolerance, transplantation tolerance, and attenuation of allergic response. Higher proportion of Treg cells has been observed in peripheral blood of cancer cases compared to controls. Little is known about potential epidemiological predictors of Treg cell levels in healthy individuals. We conducted a cross-sectional study including 75 healthy women, between 20 and 80 years of age, who participated in the Data Bank and BioRepository (DBBR) program at Roswell Park Cancer Institute (RPCI), Buffalo, NY, USA. Peripheral blood levels of CD4+CD25+FOXP3+Treg cells were measured using flow cytometric analysis. A range of risk factors was evaluated using Wilcoxon Rank-Sum test, Kruskal-Wallis test, and linear regression. Age, smoking, medications for treatment of osteoporosis, postmenopausal status, body mass index (BMI), and hormone replacement therapy (HRT) were found to be significant positive predictors of Treg cell levels in peripheral blood (P≤0.05). Higher education, exercise, age at first birth, oral contraceptives, and use of Ibuprofen were found be significant (P<0.05) negative predictors of Treg levels. Thus, various epidemiological risk factors might explain interindividual variation in immune response to pathological conditions, including cancer.
Duodenal Tumor Presenting as Acquired Hemophilia in an 88-Year-Old Woman: A Clinical Case and Review of the Literature
Authors: Murray Nigel P. , Moncada Juan Carlos , Moran Marcelo
Published: August 2012

Acquired hemophilia is a rare disease, presenting with severe hemorrhage, we present a case caused by a duodenal tumor, the clinical management, ethical implications, treatment recommendations, and a review of the literature.
Peyronie’s Disease: Still a Surgical Disease
Authors: Martinez Daniel , Ercole Cesar E. , Hakky Tariq S. , Kramer Andrew , Carrion Rafael
Published: August 2012

Peyronie’s Disease (PD) remains a challenging and clinically significant morbid condition. Since its first description by François Gigot de la Peyronie, much of the treatment for PD remains nonstandardized. PD is characterized by the formation of fibrous plaques at the level of the tunica albuginea. Clinical manifestations include morphologic changes, such as curvatures and hourglass deformities. Here, we review the common surgical techniques for the management of patients with PD.
An Economic Hybrid J2 Analytical Orbit Propagator Program Based on SARIMA Models
Authors: San-Juan Juan Félix , San-Martín Montserrat , Pérez Iván
Published: August 2012

We present a new economic hybrid analytical orbit propagator program based on SARIMA models, which approximates to a 4 × 4 tesseral analytical theory for a Quasi‐Spot satellite. The J2 perturbation is described by a first‐order closed‐form analytical theory, whereas the effects produced by the higher orders of J2 and the perturbation of the rest of zonal and tesseral harmonic coefficients are modelled by SARIMA models. Time series analysis is a useful statistical prediction tool, which allows building a model for making future predictions based on the study of past observations. The combination of the analytical techniques and time series analysis allows an increase in accuracy without significant loss in efficiency of the new propagators, as a consequence of modelling higher‐order terms and other perturbations are not taken into account in the analytical theory.
Association between Urinary N-Acetyl-Beta-D-Glucosaminidase and Microalbuminuria in Diabetic Black Africans
Authors: Udomah Francis Patrick , Ekpenyong Ekrikpo Udeme , Effa Emmanuel , Salako Babatunde , Arije Ayodeji , Kadiri Solomon
Published: August 2012

Diabetes mellitus is the commonest cause of ESRD worldwide and third most common cause in Nigeria. Recent reports from Nigeria indicate the prevalence of diabetic nephropathy as an aetiology of ESRD is increasing necessitating early diagnosis of diabetic nephropathy. We measured the urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG), NAG/creatinine ratio, urinary protein-creatinine ratio and calculated eGFR in 30 recently diagnosed nonhypertensive diabetics and 67 controls. The age and sex distribution, systolic blood pressure, serum and urinary creatinine were similar for both groups. There was higher urinary excretion of NAG (304 versus 184 μmol/h/L,P<0.001) and NAG/creatinine ratio (21.2 versus 15.7 μmol/h/L/mmolCr,P<0.001) in the diabetics than controls. There was a strong correlation between NAG/creatinine ratio and albumin/creatinine ratio (r=0.74,P<0.001). A multivariate linear regression model showed a significant linear relationship between NAG/creatinine ratio and albumin/creatinine ratio after adjusting for the effect of blood pressure, age, sex, and serum creatinine. The strong association found between albumin/creatinine ratio and NAG/creatinine ratio perhaps indicates the need for further investigation of the clinical utility of NAG/creatinine ratio as a screening tool for early nephropathy in African diabetics.
Osteoarthritis of the Wrist STT Joint and Radiocarpal Joint
Authors: Wollstein Ronit , Clavijo Julio , Gilula Louis A.
Published: August 2012

Our understanding of wrist osteoarthritis (OA) lags behind that of other joints, possibly due to the complexity of wrist biomechanics and the importance of ligamentous forces in the function of the wrist. Scaphotrapeziotrapezoidal (STT) OA is common, but its role in wrist clinical pathology and biomechanics is unclear. We identified the prevalence of radiographic STT joint OA in our hand clinic population and defined the relationship between STT and radiocarpal OA in wrist radiographs. One hundred consecutive wrist clinical and radiographic exams were retrospectively reviewed. Radiographs were evaluated for the presence and stage of OA. The mean age was 61.3 (14.5) years. The radiographic occurrence of STT joint OA was 59% and of radiocarpal (RC) OA was 29%. Radiographic STT and RC joint OA were inversely related. Tenderness over the STT joint in physical exam was not associated with OA in the STT or other joints. STT OA in our series was not related to wrist pain. These findings support the discrepancy between radiographic and cadaver findings and clinically significant OA in this joint. The inverse relationship between STT and RC OA, as seen in scapholunate advanced collapse (SLAC) wrist, requires further biomechanical study.
Unintended Pregnancy and Abortion Access in the United States
Authors: Medoff Marshall H.
Published: August 2012

This study examines the relationship between state restrictive abortion laws and the incidence of unintended pregnancy. Using 2006 data about pregnancy intentions, the empirical results found that no Medicaid funding, mandatory counseling laws, two-visit laws, and antiabortion attitudes have no significant effect on the unintended pregnancy rate, unwanted pregnancy rate, unintended pregnancy ratio, or the unwanted pregnancy ratio. Parental involvement laws have a significantly negative effect on the unintended and unwanted pregnancy rates and ratios. This latter result suggests that parental involvement laws alter teen minors' risky sexual activity and that behavioral modification has a cumulative effect on the pregnancy avoidance behavior of adult women of childbearing age. The empirical results remain robust even after controlling for regional effects, outliers, and the two different types of parental involvement laws.
A Stochastic Dynamic Model of Computer Viruses
Authors: Zhang Chunming , Zhao Yun , Wu Yingjiang , Deng Shuwen
Published: August 2012

A stochastic computer virus spread model is proposed and its dynamic behavior is fully investigated. Specifically, we prove the existence and uniqueness of positive solutions, and the stability of the virus‐free equilibrium and viral equilibrium by constructing Lyapunov functions and applying Ito′s formula. Some numerical simulations are finally given to illustrate our main results.
Evolving Model for the Complex Traffic and Transportation Network Considering Self‐Growth Situation
Authors: Zhang Wei , Xu Di
Published: August 2012

It has been approved that the scale‐free feature exists in various complex networks, such as the internet, the cell or the biological networks. In order to analyze the influence of the self‐growth phenomenon during the growth on the structure of traffic and transportation network, we formulated an evolving model. Based on the evolving model, we prove in mathematics that, even that the self‐growth situation happened, the traffic and transportation network owns the scale‐free feature due to that the node degree follows a power‐law distribution. A real traffic and transportation network, China domestic airline network is tested to consolidate our conclusions. We find that the airline network has a node degree distribution equivalent to the power‐law of which the estimated scaling parameter is about 3.0. Moreover the standard error of the estimated scaling parameter changes according to the self‐growth probability. Our findings could provide useful information for determining the optimal structure or status of the traffic and transportation network.
Absence of Multiple Sclerosis and Demyelinating Diseases among Lacandonians, a Pure Amerindian Ethnic Group in Mexico
Authors: Flores Jose , González Silvia , Morales Ximena , Yescas Petra , Ochoa Adriana , Corona Teresa
Published: August 2012

Multiple Sclerosis (MS) is a highly polymorphic disease characterized by different neurologic signs and symptoms. In MS, racial and genetic factors may play an important role in the geographic distribution of this disease. Studies have reported the presence of several protective alleles against the development of autoimmune disorders. In the case of MS, however, they help define MS as a complex disease, and confirm the importance of environmental agents as an independent variable not associated with ethnicity. We carried out an on-site epidemiological study to confirm the absence of MS or NMO among Lacandonians, a pure Amerindian ethnic group in Mexico. We administered a structured interview to 5,372 Lacandonians to assess by family background any clinical data consistent with the presence of a prior demyelinating event. Every participating subject underwent a comprehensive neurological examination by a group of three members of the research team with experience in the diagnosis and treatment of demyelinating disorders to detect clinical signs compatible with a demyelinating disease. We did not find any clinical signs compatible with multiple sclerosis among study participants.
Both Acute and Chronic Placental Inflammation Are Overrepresented in Term Stillbirths: A Case-Control Study
Authors: Hulthén Varli Ingela , Petersson Karin , Kublickas Marius , Papadogiannakis Nikos
Published: August 2012

Objective. To elucidate differences in the frequency and severity of acute chorioamnionitis (CAM) and chronic villitis in placentas from stillborns compared with liveborns at term and to evaluate other risk factors and placental findings.Design. Case-control study.Setting. All delivery wards in major Stockholm area.Population or Sample. Placentas from stillborn/case (n=126) and liveborn/control (n=273) neonates were prospectively collected between 2002 and 2005.Methods. CAM was assessed on a three-grade scale based on the presence and distribution of polymorphonuclear leucocytes in the chorion/amnion. The presence of vasculitis and funisitis was recorded separately. Chronic villitis was diagnosed by the presence of mononuclear cells in the villous stroma. Relevant clinical data were collected from a specially constructed, web-based database. The statistic analyses were performed using multivariable logistic regression.Results. CAM (especially severe, AOR: 7.39 CI: 3.05–17.95), villous immaturity (AOR: 7.17 CI: 2.66–19.33), villitis (<1 % AOR: 4.31 CI: 1.16–15.98; ≥1 %, AOR: 3.87 CI: 1.38–10.83), SGA (AOR: 7.52 CI: 3.06–18.48), and BMI>24.9(AOR: 2.06 CI: 1.21–3.51) were all connected to an elevated risk of term stillbirth.Conclusions. We found that CAM, chronic villitis, villous immaturity, SGA, and maternal overweight, but not vasculitis or funisitis are independently associated with risk for stillbirth at term.
Projectile Nose Mass Abrasion of High-Speed Penetration into Concrete
Authors: Wu Haijun , Qian Fei , Huang Fenglei , Wang Yinan
Published: August 2012

Based on the dynamic spherical cavity expansion theory of concrete and the analysis of experimental data, a mass abrasion model of projectile considering the hardness of aggregates, the relative strength of target and projectile, and the initial impact velocity is constructed in this paper. Furthermore, the effect of mass abrasion on the penetration depth of projectile and the influence of hardness of aggregates and strength of projectile on penetration depth and mass loss are also analyzed. The results show that, for the ogive-nose projectile with the CRH of 3 and aspect ratio of 7 penetrating the concrete of 35 MPa, the “rigid-body penetration” model is available when the initial impact velocity is lower than 800 m/s. However, when the initial impact velocity is higher than 800 m/s, the “deforming/eroding body penetration” model should be adopted. Through theoretical analysis and numerical calculation, the results indicate that the initial impact velocity is the most important factor of mass abrasion. The hardness of aggregates and the strength of projectile are also significant factors. But relatively speaking, the sensitivity of strength of projectile to mass abrasion is higher, which indicates that the effect of projectile material on mass abrasion is more dramatic than the hardness of aggregates.
Parents’ Readiness to Change Affects BMI Reduction Outcomes in Adolescents with Polycystic Ovary Syndrome
Authors: Jakubowski Karen P. , Black Jessica J. , El Nokali Nermeen E. , Belendiuk Katherine A. , Hannon Tamara S. , Arslanian Silva A. , Rofey Dana L.
Published: August 2012

Evidence supports the importance of parental involvement for youth’s ability to manage weight. This study utilized the stages of change (SOC) model to assess readiness to change weight control behaviors as well as the predictive value of SOC in determining BMI outcomes in forty adolescent-parent dyads (mean adolescent age = 15 ± 1.84 (13–20), BMI = 37 ± 8.60; 70% white) participating in a weight management intervention for adolescent females with polycystic ovary syndrome (PCOS). Adolescents and parents completed a questionnaire assessing their SOC for the following four weight control domains: increasing dietary portion control, increasing fruit and vegetable consumption, decreasing dietary fat, and increasing usual physical activity. Linear regression analyses indicated that adolescent change in total SOC from baseline to treatment completion was not predictive of adolescent change in BMI from baseline to treatment completion. However, parent change in total SOC from baseline to treatment completion was predictive of adolescent change in BMI, (t(24) = 2.15,p=0.043). Findings support future research which carefully assesses adolescent and parent SOC and potentially develops interventions targeting adolescent and parental readiness to adopt healthy lifestyle goals.
Placement of Hemodialysis Catheters with a Technical, Functional, and Anatomical Viewpoint
Authors: Aydin Zeki , Gursu Meltem , Uzun Sami , Karadag Serhat , Tatli Emel , Sumnu Abdullah , Ozturk Savas , Kazancioglu Rumeyza
Published: August 2012

Aims. Vascular access is of prime importance for hemodialysis patients. We aimed to study early complications of hemodialysis catheters placed in different central veins in patients with acute or chronic renal failure with or without ultrasound (US ) guidance.Material and Methods. Patients who were admitted to our unit between March 2008 and December 2010 with need for vascular access have been included. 908 patients were examined for their demographic parameters, primary renal disease, and indication for catheterization, type and location of the catheter, implantation technique, and acute complications.Results. The mean age of the patients was 60.6 ± 16.0 years. 643 (70.8 %) of the catheters were temporary while 265 (29.2%) were permanent. 684 catheters were inserted to internal jugular veins, 213 to femoral, and 11 to subclavian veins. Arterial puncture occurred in 88 (9.7%) among which 13 had resultant subcutaneous hematoma. No patient had lung trauma and there had been no need for removal of the catheter or a surgical intervention for complications. US guidance in jugular vein and experience of operator decreased arterial puncture rate.Conclusion. US-guided replacement of catheter to internal jugular vein would decrease complication rate. Referral to invasive nephrologists may decrease use of subclavian vein. Experience improves complication rates even under US guidance.
Apical Ballooning Syndrome (Takotsubo Cardiomyopathy) after Permanent Dual-Chamber Pacemaker Implantation
Authors: Gardini Armando , Fracassi Francesco , Boldi Emiliano , Albiero Remo
Published: August 2012

Apical ballooning syndrome, also called takotsubo cardiomyopathy, has been recently reported. It may mimic acute myocardial infarction and is typically observed in postmenopausal women after stressful events. A 75-year-old female after permanent dual chamber pacemaker implant complained of chest pain with repolarization alterations suggesting acute myocardial ischemia. Echocardiography showed a left ventricle with akinesia of the apical portions and reduced global systolic function. The patient was treated with antithrombotic agents and intravenous nitrates. No coronary lesions were found at angiography. At ventriculography, a typical takotsubo-like shape of the left ventricle was observed. The clinical and echocardiographic picture normalized at discharge.
Analysis of an SEIS Epidemic Model with a Changing Delitescence
Authors: Wang Jinghai
Published: August 2012

An SEIS epidemic model with a
changing delitescence is studied. The disease‐free equilibrium and
the endemic equilibrium of the model are studied as well. It is
shown that the disease‐free equilibrium is globally stable under
suitable conditions. Moreover, we also show that the unique endemic
equilibrium of the system is globally asymptotically stable under
certain conditions.
Existence of Unbounded Solutions for a Third‐Order Boundary Value Problem on Infinite Intervals
Authors: Lian Hairong , Zhao Junfang
Published: August 2012

We generalize the unbounded upper and lower solution method
to a third‐order ordinary differential equation on the half line subject to the Sturm‐Liouville
boundary conditions. By using such techniques and the Schäuder fixed point theorem, some
criteria are presented for the existence of solutions and positive ones to the problem discussed.
Enhancement of Lipid Extraction from Marine Microalga,ScenedesmusAssociated with High-Pressure Homogenization Process
Authors: Cho Seok-Cheol , Choi Woon-Yong , Oh Sung-Ho , Lee Choon-Geun , Seo Yong-Chang , Kim Ji-Seon , Song Chi-Ho , Kim Ga-Vin , Lee Shin-Young , Kang Do-Hyung , Lee Hyeon-Yong
Published: August 2012

Marine microalga,Scenedesmussp., which is known to be suitable for biodiesel production because of its high lipid content, was subjected to the conventional Folch method of lipid extraction combined with high-pressure homogenization pretreatment process at 1200 psi and 35°C. Algal lipid yield was about 24.9% through this process, whereas only 19.8% lipid can be obtained by following a conventional lipid extraction procedure using the solvent, chloroform : methanol (2 : 1, v/v). Present approach requires 30 min process time and a moderate working temperature of 35°C as compared to the conventional extraction method which usually requires >5 hrs and 65°C temperature. It was found that this combined extraction process followed second-order reaction kinetics, which means most of the cellular lipids were extracted during initial periods of extraction, mostly within 30 min. In contrast, during the conventional extraction process, the cellular lipids were slowly and continuously extracted for >5 hrs by following first-order kinetics. Confocal and scanning electron microscopy revealed altered texture of algal biomass pretreated with high-pressure homogenization. These results clearly demonstrate that the Folch method coupled with high-pressure homogenization pretreatment can easily destruct the rigid cell walls of microalgae and release the intact lipids, with minimized extraction time and temperature, both of which are essential for maintaining good quality of the lipids for biodiesel production.
Effect of Sertraline on Uremic Pruritus Improvement in ESRD Patients
Authors: Shakiba Mansor , Sanadgol Hoshang , Azmoude Hamid Reza , Mashhadi Mohamad Ali , Sharifi Hassan
Published: August 2012

Background. Although uremic pruritus is a common and upsetting problem of chronic kidney disease, there is no approved treatment for it. This study was undertaken to find the efficiency of sertraline as a possible treatment for uremic pruritus.Methods. 19 ESRD patients under hemodialysis with severe chronic pruritus were randomly selected to participate in this before-after clinical trial. Before and after starting treatment with sertraline, a detailed pruritus history was obtained and pruritus graded by the 30-item inventory of pruritus that patients based on priorities grade allocated to 3 classes. Subjects were treated with sertraline 50 mg oral daily for four months, with monthly assessments of pruritus symptoms.Results. Before treatment with sertraline, the grade of pruritus in 9 (47.4%) patients was moderate and severe in 10 (52.6%) patients. After treatment, grade of pruritus in 11 (57.8%) patients was weak, 6 (31.5%) have moderate and only 2 (10.7%) patients have severe pruritus. Of 10 patients with severe pruritus, 5 (50%) patients experiencing weak pruritus, and 4 (40%) patients have moderate pruritus after treatment. Based on Wilcoxon signed-rank test, the difference between the grade of pruritus before and after treatment with sertraline was significant (P=0.001).Conclusions. Although no definitive recommendation can be made regarding treatment of uremic pruritus, we found an increased antipruritic effect of sertraline in ESRD patients.
Molecular Regulation of the Mitochondrial F1Fo-ATPsynthase: Physiological and Pathological Significance of the Inhibitory Factor 1 (IF1)
Authors: Faccenda Danilo , Campanella Michelangelo
Published: August 2012

In mammals, the mitochondrial F1Fo-ATPsynthase sets out the energy homeostasis by producing the bulk of cellular ATP. As for every enzyme, the laws of thermodynamics command it; however, it is privileged to have a dedicated molecular regulator that controls its rotation. This is the so-called ATPase Inhibitory Factor 1 (IF1) that blocks its reversal to avoid the consumption of cellular ATP when the enzyme acts as an ATP hydrolase. Recent evidence has also demonstrated that IF1may control the alignment of the enzyme along the mitochondrial inner membrane, thus increasing the interest for the molecule. We conceived this review to outline the fundamental knowledge of the F1Fo-ATPsynthase and link it to the molecular mechanisms by which IF1regulates its way of function, with the ultimate goal to highlight this as an important and possibly unique means to control this indispensable enzyme in both physiological and pathological settings.
Hematopoietic Stem Cell Transplantation for Systemic Lupus Erythematosus
Authors: Marmont du Haut Champ Alberto M.
Published: August 2012

Two streams of research are at the origin of the utilization of hematopoietic stem cell transplantation (HSCT) for severe autoimmune diseases (SADs). The allogeneic approach came from experimental studies on lupus mice, besides clinical results in coincidental diseases. The autologous procedure was encouraged by researches on experimental neurological and rheumatic disorders. At present the number of allogeneic HSCT performed for human SADs can be estimated to not over 100 patients, and the results are not greatly encouraging, considering the significant transplant-related mortality (TRM) and the occasional development of a new autoimmune disorder and/or relapses notwithstanding full donor chimerism. Autologous HSCT for refractory SLE has become a major target. Severe cases have been salvaged, TRM is low and diminishing, and prolonged clinical remissions are obtainable. Two types of immune resetting have been established, “re-education” and regulatory T cell (Tregs) normalization. Allogeneic HSCT for SLE seems best indicated for patients with disease complicated by an oncohematologic malignancy. Autologous HSCT is a powerful salvage therapy for otherwise intractable SLE. The duration of remission in uncertain, but a favorable response to previously inactive treatments is a generally constant feature. The comparison with new biological agents, or the combination of both, are to be ascertained.
Glycemic Control after Total Pancreatectomy for Intraductal Papillary Mucinous Neoplasm: An Exploratory Study
Authors: Jamil Laith H. , Chindris Ana M. , Gill Kanwar R. S. , Scimeca Daniela , Stauffer John A. , Heckman Michael G. , Meek Shon E. , Nguyen Justin H. , Asbun Horacio J. , Raimondo Massimo , Woodward Timothy A. , Wallace Michael B.
Published: August 2012

Background. Glycemic control following total pancreatectomy (TP) has been thought to be difficult to manage. Diffuse intraductal papillary mucinous neoplasm (IPMN) is a potentially curable precursor to pancreatic adenocarcinoma, best treated by TP. Objective. Compare glycemic control in patients undergoing TP for IPMN to patients with type 1 diabetes mellitus (DM). Design/Setting. Retrospective cohort. Outcome Measure. Hemoglobin A1C(HbA1C) at 6, 12, 18, and 24 months after TP. In the control group, baseline was defined as 6 months prior to the first HbA1c measure. Results. Mean HgbA1C at each point of interest was similar between TP and type I DM patients (6 months (7.5% versus 7.7%, P=0.52), 12 months (7.3% versus 8.0%, P=0.081), 18 months (7.7% and 7.6%, P=0.64), and at 24 months (7.3% versus 7.8%, P=0.10)). Seven TP patients (50%) experienced a hypoglycemic event compared to 65 type 1 DM patients (65%, P=0.38). Limitations. Small number of TP patients, retrospective design, lack of long-termfollowup. Conclusion. This suggests that glycemic control following TP for IPMNcan be well managed, similar to type 1 DM patients. Fear of DM following TP for IPMN should not preclude surgery when TP is indicated.