bluuebunny/crossref_metadata_2025 huggingface dataset:
Genomics and Proteomics of Pulmonary Vascular Disease
Authors: Geraci Mark , Meyrick Barbara
Published: January 2011

Study of RNA and proteins in cells of both normal and diseased tissues is providing researchers with new knowledge of disease pathologies. While still in its early stages, high‐throughput expression analysis is improving our understanding of the pathogenesis of pulmonary arterial hypertension (PAH). While many studies have used microarray and proteomic analyses as “hypothesis‐generating” tools, the technologies also have potential to identify and quantify biomarkers of disease. To date, many of the published studies have examined gene expression profiles of tissue biopsies, others have utilized cells from peripheral blood. Microarray technology has been employed successfully in the investigation of a diverse array of human diseases. The potential of high‐throughput expression analysis to improve our understanding of the pathogenesis of PAH is highlighted in this review. Proteomic studies of PAH and pulmonary vascular diseases in general have been little utilized thus far. To date, such studies are few and no consistent biomarker has emerged from studies of either plasma or blood cells from idiopathic pulmonary arterial hypertension (IPAH) patients. The studies of both lung tissue and lymphocytes are perhaps more revealing and suggest that changes in the cytoskeletal machinery may play a role in the pathogenesis of idiopathic pulmonary arterial hypertension. The oncology literature has demonstrated the utility of gene microarray analysis to predict important outcomes such as response to therapy and survival. It is likely that in the near future, gene microarrays and proteomic analyses will also be employed in a pharmacogenomics approach in PAH, helping to identify the most appropriate therapies for individual patients. © 2011 American Physiological Society.
Compr Physiol
1:467‐483, 2011.
Three novel improved CMOS C‐multipliers
Authors: Aguado‐Ruiz Jesus , Lopez‐Martin Antonio J. , Ramirez‐Angulo Jaime
Published: January 2011

Three novel improved CMOS capacitance scaling schemes are presented and compared with some conventional schemes. The novel topologies that use a modified second‐generation current conveyor, an improved cascode current mirror and an OTA with two outputs connected in current steering configuration provide higher values ofQand better frequency responses than conventional structures using basic current mirror schemes, as the simple current mirror or cascode current mirrors. Simulation results and some measurements of a chip prototype are presented. Copyright © 2011 John Wiley & Sons, Ltd.
Copper(II) and Zinc(II) Complexes with a Photoactive Bridging Ligand Based on Carbazole: Synthesis, Structures, Electronic and Magnetic Properties
Authors: Spielberg Eike T. , Plass Winfried
Published: January 2011

The synthesis of the new Schiff base ligand N‐(4‐methoxyphenyl)‐3,4‐bis(salicylidenimino)carbazole (H2SalCarbOMe) is described. It readily reacts with copper(II) andzinc(II) ions to form metallacycles of the general formula [M2(SalCarbOMe)2] (M = Cu, Zn). Their structures are determined by X‐ray crystallography and show significant differences for the coordination at the metal ion with a nearly tetrahedral arrangement for ZnII, but a considerable distortion towards square‐planar geometry for CuII. This in turn leads to substantial differences for the dihedral angles observed between the salicylidene and carbazole moieties. As a consequence different arrangements in the unit cell are observed, which becomes particularly obvious when the additional solvent molecules of crystallization are considered. For the ZnII compound this leads to the incorporation of a chloroform and a methanol molecule in fixed positions, whereas in the structure of the CuII compound a higher number of solvent molecules (chloroform, methanol, and water) in highly disordered crystallographic positions is observed. The optical and magnetic properties have been characterized for both complexes. They both show two band fluorescence in the visible region with emission maxima at 531 and 586 nm for the ZnII compound and 488 and 580 nm in the CuII complex. The electronic properties have been further elucidated by quantum chemical calculations. For the two copper(II) ions an antiferromagnetic interaction through the carbazole bridging ligand with an exchange coupling constant of J = –3.1 cm–1 is observed. ESR spectroscopy reveals a rhombic signal with g values [gx, gy, gz] = [2.057, 2.125, 2.200] consistent with the distorted coordination geometry around the copper(II) ions.
Synthesis and NMR Binding Studies towards Rational Design of a Series of Electron‐Withdrawing Diamide Receptors/Organocatalysts
Authors: Kinsella Michael , Duggan Patrick G. , Muldoon Jimmy , Eccles Kevin S. , Lawrence Simon E. , Lennon Claire M.
Published: January 2011

A related series of bisamides have been evaluated for rational correlation between anion complexation and organocatalysis: remarkable enhancement of hydrogen bonding to anions was observed along with significant increases in catalytic activity in the Baylis–Hillman reaction. In addition, X‐ray crystallography showed a large degree of pre‐organisation was observed in one receptor by incorporation of bis(trifluoromethyl)aniline groups along with a thioamide functionality. A novel bifunctional amide/N‐acylsulfonamide within the series gave the best catalytic profile.
Preoperative ultrasonographic tumor characteristics as a predictive factor of tumor stage in papillary thyroid carcinoma
Authors: Kim Sang Soo , Lee Byung‐Joo , Lee Jin‐Choon , Kim Seong‐Jang , Lee Soo Hyung , Jeon Yun Kyung , Kim Bo Hyun , Kim Yong‐Ki , Kim In‐Joo
Published: January 2011

Background

The purpose of this study was to evaluate the usefulness of tumor characteristics on ultrasonography for predicting the pathologic stage of papillary thyroid carcinoma.

Methods

We evaluated 354 patients who underwent surgery for papillary thyroid carcinoma (≤2 cm). We analyzed the preoperative ultrasonography findings such as tumor size, shape, margin, echogenicity, calcification, vascularity, and contact with the capsule.

Results

Tumor size, echogenicity, and contact with the capsule were predictive for the presence of extrathyroid extension. Size and echogenicity were significantly associated with central lymph node metastasis in the multivariate analysis. Some ultrasonography characteristics such as round shape, well‐defined margin, and isoechoic echogenicity were negative predictive factors for extrathyroid extension and central lymph node metastasis.

Conclusion

Preoperative tumor characteristics on ultrasonography correlated with several prognostic factors for papillary thyroid carcinoma and may serve as preoperative supplementary markers for determining the optimal extent of surgery. © 2011 Wiley Periodicals, Inc. Head Neck, 2011
Adult hippocampal glucocorticoid receptor expression and dentate synaptic plasticity correlate with maternal care received by individuals early in life
Authors: van Hasselt Felisa N. , Cornelisse Sandra , Yuan Zhang Tie , Meaney Michael J. , Velzing Els H. , Krugers Harm J. , Joëls Marian
Published: January 2011

Maternal care in mammals is the prevailing environmental influence during perinatal development. The adult rat offspring of mothers exhibiting increased levels of pup licking/grooming (LG; High LG mothers), compared to those reared by Low LG dams, show increased hippocampal glucocorticoid receptor expression, complex dendritic tree structure, and an enhanced capacity for synaptic potentiation. However, these data were derived from studies using the total amount of maternal care directed toward the entire litter, thus ignoring possible within‐litter variation. We show that the amount of LG received by individual pups within a litter varies considerably. Therefore, we questioned if the amount of LG received by individual pups correlates with and thus putatively predicts later hippocampal structure and function. To this end, LG‐scores were determined during the first postnatal week for all pups in 32 litters and correlated with neuroendocrine and hippocampal parameters in young‐adulthood. Pup LG‐score positively correlated with the glucocorticoid receptor mRNA expression in the adult hippocampus. Moreover, the ability to induce synaptic potentiation in the dentate gyrus in vitro was enhanced in animals with high LG‐scores. Structural plasticity correlated less reliably with LG‐scores early in life and differed between sexes. Male offspring with high LG‐scores displayed fewer newborn neurons, higher brain derived neurotrophic factor expression and tended to have more complex granule cell dendritic trees. We conclude that even moderate variations in early life environment have a major impact on adult hippocampal function. This principle could provide a mechanistic basis for individual differences in susceptibility to psychopathology. © 2011 Wiley Periodicals, Inc.
Sprouty2 and ‐4 regulate axon outgrowth by hippocampal neurons
Authors: Hausott Barbara , Vallant Natalie , Schlick Bettina , Auer Maria , Nimmervoll Benedikt , Obermair Gerald J. , Schwarzer Christoph , Dai Fangping , Brand‐Saberi Beate , Klimaschewski Lars
Published: January 2011

Sprouty proteins act as negative feedback inhibitors of fibroblast growth factor (FGF) signaling. FGFs belong to the neurotrophic factors and are involved in axonal growth during development and repair. We investigated the expression of Sprouty isoforms in hippocampal neurons as well as the regulation of Sprouty2 and ‐4 during development and their role in axon growth. Sprouty2 and ‐4 were located in the nucleus, the cytoplasm, in dendrites, and axons of hippocampal neurons concentrated in growth cones. During development in vivo and differentiation in vitro, expression of Sprouty2 and ‐4 was gradually downregulated in hippocampal neurons. Between 5 and 24 days in culture expression of both Sprouty isoforms was reduced by 70%. In vivo expression of Sprouty2 was reduced by 79% and of Sprouty4 by 93% on postnatal day 14 compared to embryonic day 16.5. Downregulation of Sprouty2 and ‐4 by shRNAs strongly promoted elongative axon growth by cultured hippocampal neurons, which was further increased by FGF‐2 treatment. In addition, FGF‐2 reduced expression of Sprouty2 by 33% and of Sprouty4 by 44%. Together, our results imply that Sprouty2 and ‐4 are downregulated in the hippocampus during postnatal brain development and that they can act as regulators of developmental axon growth. © 2011 Wiley Periodicals, Inc.
Drebrin A expression is altered after pilocarpine‐induced seizures: Time course of changes is consistent for a role in the integrity and stability of dendritic spines of hippocampal granule cells
Authors: Sbai Oualid , Khrestchatisky Michel , Esclapez Monique , Ferhat Lotfi
Published: January 2011

We used a pathophysiological model of temporal lobe epilepsy induced by pilocarpine in adult rats in order to assess the in vivo role of drebrin A (DA), one of the major regulators of F‐actin. This model displays a dynamic reorganization of the glutamatergic network including neo‐spinogenesis, morphogenesis, and neo‐synaptogenesis associated with an aberrant sprouting of granule cell axons in the dentate gyrus (DG). This reactive plasticity contributes in dentate granule‐cell hyperexcitability that could lead to the emergence of recurrent spontaneous seizures. We investigated the hippocampal DA expression changes in pilocarpine animals using immunohistochemical, Western blot, and in situ hybridization analyses. We showed that DA immunoreactivity was decreased in the inner molecular layer (IML) and in the hilus (H) of the DG, at latent stage, when spinogenesis and morphogenesis occur. Western blot analysis confirmed these overall hippocampal decreases of DA protein expression. At chronic stage, when newly formed glutamatergic synapses are being established, the levels of immunolabeling for DA in the H and the IML were similar to control rats. This recovery is likely due to the increase of DA mRNA in perikarya of hilar and granule cells. Interestingly, our data showed that the changes pattern of labeling for Bassoon, a specific marker for presynaptic active zone, in the IML of pilocarpine‐treated animals paralleled those found for DA at all time points examined. Furthermore, our double and triple immunofluorescence studies showed that the recovery in DA levels in the IML occurred within the dendritic spines involved in glutamatergic active synapses of presumed granule cells. Altogether, our results indicate that in vivo DA is not critical for spinogenesis and morphogenesis but instead is consistent with an involvement in synaptic structural integrity, stabilization, and function. Thus, DA appears as a novel modulator of reactive synaptic plasticity associated with epilepsy. © 2011 Wiley Periodicals, Inc.
Differential involvement of protein synthesis and actin rearrangement in the reacquisition of contextual fear conditioning
Authors: Motanis Helen , Maroun Mouna
Published: January 2011

Extinction learning is associated with a decline of the conditioned fear response (CR). However, re‐exposure to the unconditioned stimulus (US, shock) is associated with the return of the fear response. This study aimed to study the role of protein synthesis and actin rearrangement in the CA1 hippocampal subregion and the basolateral amygdala (BLA) in acquisition and reacquisition of contextual fear conditioning. To that end, we trained rats on contextual fear conditioning and extinction, and on the last extinction training session we reconditioned the animals by re‐exposure to the US. Immediately after, rats were microinfused with the protein synthesis inhibitor anisomycin or the actin rearrangement inhibitor cytochalasin D into either the BLA or the CA1. The results of this study show differential involvement of anisomycin and cytochalasin D in the acquisition and reacquisition of contextual fear conditioning. Specifically, while the microinfusion of anisomycin into the BLA or the CA1 immediately after reconditioning of fear did not inhibit the return of fear, the microinfusion of cytochalsin D into either the BLA or the CA1 attenuated fear responses. Interestingly, the initial acquisition of contextual fear memory is dependent on intra‐BLA and CA1 protein synthesis and cytoskeletal rearrangement, since the microinfusion of these drugs blocked the formation of long‐term fear memory. The results suggest that the two processes of acquisition and reacquisition of fear are not identical and they engage different mechanisms. © 2011 Wiley Periodicals, Inc.
2010: A Small Space Odyssey with Luminescent Molecules
Authors: de Silva A. Prasanna
Published: January 2011

The road to molecular logic and computation in Belfast, Northern Ireland started with chemical sensors in Colombo, Sri Lanka. This journey is mapped out with reference to design principles, such as those for luminescent PET (photoinduced electron transfer) sensing. Applications such as those for blood electrolyte diagnostics, “lab‐on‐a‐molecule” systems, and molecular computational identification (MCID) are also met along the way.
A structural equation model of perievent panic and posttraumatic stress disorder after a community disaster
Authors: Adams Richard E. , Boscarino Joseph A.
Published: January 2011

Studies suggest that perievent panic attacks are predictive of future posttraumatic stress disorder (PTSD). Using a population of New York City residents interviewed after the World Trade Center Disaster, the authors measured event exposure, perievent panic, potential confounding, mediating variables, and PTSD. When they estimated a structural equation model, with other stressor events, psychological resources, and Year 1 and Year 2 PTSD as latent variables and adjusted for confounders, the association between perievent panic and Year 2 PTSD was not significant. Results revealed that perievent panic was predictive of Year 1 PTSD, but not Year 2 PTSD. Year 2 stressors and Year 2 psychosocial resources were the best predictors of Year 2 PTSD.
Lard‐based fats healthier than lard: Enzymatic synthesis, physicochemical properties and applications
Authors: Cheong Ling‐Zhi , Xu Xuebing
Published: January 2011

Lard has long been deemed superior to vegetable oils for culinary purposes due to its exceptional properties such as wide plastic range and special flavor values. Nevertheless, its usage over the years has seen a marked decrease due to awareness of its negative nutritional values such as high calorific content (see below) and saturated fatty acids. This paper looks into the possibilities of producing healthier lard‐based fats through “green” biocatalysis methods with particular attention given to the technical challenges of the process and their possible solutions. Alterations in physicochemical properties and application practicability of the modified lard‐based fats are also carefully elucidated.
Immunomonitoring of nuclear factor of activated T cells-regulated gene expression
Authors: Zahn Alexandra , Schott Nadja , Hinz Ulf , Stremmel Wolfgang , Schmidt Jan , Ganten Tom , Gotthardt Daniel , Meuer Stefan , Zeier Martin , Giese Thomas , Sommerer Claudia
Published: January 2011

Long-term calcineurin inhibitor (CNI) treatment can cause serious side effects in liver allograft recipients. An optimal risk-to-benefit ratio for CNI blood levels has not been established. Pharmacodynamic drug monitoring through the measurement of the CNI biological activity, that is, the expression of nuclear factor of activated T cells (NFAT)-regulated genes, seems to be a promising approach. The residual gene expression (RGE) of NFAT-regulated genes 2 and 1.5 hours after cyclosporine A (CsA) and tacrolimus (FK-506) intake was measured in 100 liver allograft recipients with 1 or more years of follow-up post-transplantation. The mean RGE in all patients was 62% ± 33%. A significant negative correlation between the CsA (P < 0.0001, r = -0.8026) and FK-506 peak levels (P < 0.0001, r = -0.6982) and the RGE of all NFAT-regulated genes was observed. Clinical reliability was proven too. In conclusion, the data presented in this pilot study reveal the applicability of the pharmacodynamic monitoring of CNI efficacy in liver allograft recipients. To confirm the advantage of individualized pharmacodynamic drug monitoring over pharmacokinetic drug monitoring with respect to clinical outcomes, controlled, prospective studies are needed.
Liver Transpl, 2011. © 2011 AASLD.
A single-center experience with biliary reconstruction in retransplantation: Duct-to-duct or roux-en-Y choledochojejunostomy
Authors: Sibulesky Lena , Heckman Michael G. , Perry Dana K. , Taner Burcin C. , Willingham Darrin L. , Nguyen Justin H.
Published: January 2011

Retransplantation is the only therapy for patients who have a failing liver graft, and it can be technically challenging. Although duct-to-duct (DD) biliary reconstruction is considered standard in deceased donor orthotopic whole organ liver transplantation, Roux-en-Y (RY) choledochojejunostomy is preferred by most for biliary reconstruction in retransplantation. We performed a retrospective review of 128 patients who underwent retransplantation after a first transplant with DD biliary construction. Of these 128 patients, 83 had DD biliary reconstructions, and 45 had RY biliary reconstructions. Log-rank tests were used to compare the complication rates between the DD and RY groups, whereas multivariate Cox proportional hazards models were used to compare patient and graft survival between the groups. The median Model for End-Stage Liver Disease score at retransplantation was significantly higher in the DD group (27 versus 21, P = 0.005). The median length of follow-up was 3.3 years. The biliary complication rates were 7% and 11% in the DD group and 10% and 10% in the RY group 30 days and 1 year after retransplantation, respectively (P = 0.73). The rates of primary graft nonfunction complications, hepatic artery thrombosis complications, and reoperation did not differ significantly between groups (all P ≥ 0.37). In comparison with RY reconstruction, there was no evidence of a difference in patient survival (relative risk = 0.79, P = 0.47) or graft survival (relative risk = 0.94, P = 0.85) for patients with DD reconstruction in multivariate analysis. In conclusion, our results provide evidence that DD biliary reconstruction is feasible in liver retransplantation without increased rates of biliary complications or compromised patient and graft survival. Further studies with larger sample sizes are needed. Liver Transpl 710-716, 2011. © 2011 AASLD.
Noninvasive diagnosis of acute cellular rejection in liver transplant recipients: A proteomic signature validated by enzyme-linked immunosorbent assay
Authors: Massoud Omar , Heimbach Julie , Viker Kimberly , Krishnan Anuradha , Poterucha John , Sanchez William , Watt Kymberly , Wiesner Russell , Charlton Michael
Published: January 2011

The diagnosis of acute cellular rejection (ACR) requires liver biopsy with its attendant expense and risk. Our first aim was to prospectively determine in an exploratory analysis whether there is a serum proteome signature associated with histologically confirmed ACR. Our second aim was to use simpler and faster enzyme-linked immunosorbent assay (ELISA)-based assays for proteins identified as differentially abundant in the proteomic analysis to identify patients with ACR in a separate validation cohort. We used sequential high-abundance protein depletion and isobaric tag for relative and absolute quantitation liquid chromatography–tandem mass spectrometry to characterize the serum proteome in serum samples of patients with or without ACR. Seven of the 41 proteins identified as differentially abundant [serum amyloid A, complement component 4 (C4), fibrinogen, complement component 1q (C1q), complement component 3, heat shock protein 60 (HSP60), and HSP70] could be measured with ELISA-based assays in a validation cohort consisting of patients with ACR (n = 25) and patients without ACR (n = 21). The mean alanine aminotransferase (ALT) levels in patients with ACR and in patients without ACR were 198 ± 27 and 153 ± 34 U/L, respectively. Among the 7 proteins for which ELISA assays were available, C4 and C1q were both independent predictors of ACR. C4 had the greatest predictivity for differentiating patients with or without ACR. A C4 level ≤ 0.31 g/L had a sensitivity of 97%, a specificity of 62%, a positive predictive value of 74%, and a negative predictive value of 94%. A C4 level ≤ 0.31 g/L and an ALT level ≥ 70 IU/mL together had a sensitivity of 96%, a specificity of 81%, a positive predictive value of 86%, and a negative predictive value of 94%. In summary, in this exploratory analysis, serum C4 and ALT levels were highly predictive of ACR in liver transplant recipients. Confirmation in a prospective, larger, and diverse population is needed. Liver Transpl 17:723-732, 2011. © 2011 AASLD.
Decellularized liver matrix as a carrier for the transplantation of human fetal and primary hepatocytes in mice a
Authors: Zhou Ping , Lessa Nataly , Estrada Daniel C. , Severson Ella B. , Lingala Shilpa , Zern Mark A. , Nolta Jan A. , Wu Jian
Published: January 2011

The transplantation of primary hepatocytes has been shown to augment the function of damaged livers and to bridge patients to liver transplantation. However, primary hepatocytes often have low levels of engraftment and survive for only a short time after transplantation. To explore the potential benefits of using decellularized liver matrix (DLM) as a carrier for hepatocyte transplantation, DLM from whole mouse livers was generated. Human fetal hepatocytes immortalized by telomerase reconstitution (FH-hTERTs) or primary human hepatocytes were infused into the DLM, which was then implanted into the omenta of immunodeficient nonobese diabetic/severe combined immunodeficient/interleukin-2 receptor γ-deficient mice or nonobese diabetic/severe combined immunodeficient/mucopolysaccharidosis type VII mice. The removal of endogenous cellular components and the preservation of the extracellular matrix proteins and vasculature were demonstrated in the resulting DLM. Bioluminescent imaging revealed that FH-hTERTs transduced with a lentiviral vector expressing firefly luciferase survived in the DLM for 8 weeks after peritoneal implantation, whereas the luciferase signal from FH-hTERTs rapidly declined in control mice 3 to 4 weeks after transplantation via splenic injection or omental implantation after Matrigel encapsulation. Furthermore, primary human hepatocytes that were reconstituted in the DLM not only survived 6 weeks after transplantation but also maintained their function, as demonstrated by messenger RNA levels of albumin and cytochrome P450 (CYP) subtypes (CYP3A4, CYP2C9, and CYP1A1) similar to the levels in freshly isolated human primary hepatocytes (hPHs). In contrast, when hPHs were transplanted into mice via splenic injection, they failed to express CYP3A4, although they expressed albumin. In conclusion, DLM provides an excellent environment for long-term survival and maintenance of the hepatocyte phenotype after transplantation.
Liver Transpl, 2011. © 2011 AASLD.
Antiglycative and neuroprotective activity of colon‐derived polyphenol catabolites
Authors: Verzelloni Elena , Pellacani Claudia , Tagliazucchi Davide , Tagliaferri Sara , Calani Luca , Costa Lucio G. , Brighenti Furio , Borges Gina , Crozier Alan , Conte Angela , Del Rio Daniele
Published: January 2011

Scope: Dietary flavonoids and allied phenolic compounds are thought to be beneficial in the control of diabetes and its complications, because of their ability to inhibit oxidative stress, protein glycation and to act as neuroprotectants. Following ingestion by humans, polyphenolic compounds entering the large intestine undergo extensive metabolism by interaction with colonic microbiota and it is metabolites and catabolites of the parent compounds that enter the circulatory system. The aim of this study was to investigate the inhibitory activity of some colonic microbiota‐derived polyphenol catabolites against advanced glycation endproducts formation in vitro and to determine their ability, at physiological concentrations, to counteract mild oxidative stress of cultured human neuron cells.

Methods and results: This study demonstrated that ellagitannin‐derived catabolites (urolithins and pyrogallol) are the most effective antiglycative agents, whereas chlorogenic acid‐derived catabolites (dihydrocaffeic acid, dihydroferulic acid and feruloylglycine) were most effective in combination in protecting neuronal cells in a conservative in vitro experimental model.

Conclusion: Some polyphenolic catabolites, generated in vivo in the colon, were able in vitro to counteract two key features of diabetic complications, i.e. protein glycation and neurodegeneration. These observations could lead to a better control of these events, which are usually correlated with hyperglycemia.
Maternal cardiac function in normal twin pregnancy: a longitudinal study
Authors: Kuleva M. , Youssef A. , Maroni E. , Contro E. , Pilu G. , Rizzo N. , Pelusi G. , Ghi T.
Published: January 2011

Objective

To investigate maternal cardiac function in a cohort of uncomplicated twin gestations assessed longitudinally.

Methods

Women with twin pregnancies were enrolled prospectively and underwent serial maternal echocardiography at 20–23 weeks, 26–29 weeks and 30–33 weeks of gestation. Patients were excluded if any of these complications occurred after recruitment: delivery < 34 weeks; pre‐eclampsia or gestational hypertension; small‐for‐gestational age neonates (birth weight of one or both twins < 5th centile for gestational age). Cardiac findings were compared with those obtained at the same gestational age periods in a group of singleton gestations.

Results

A group of 20 uncomplicated twin gestations was obtained for analysis and 10 singleton pregnancies were then selected as controls. At each visit, mean ± SD cardiac output (CO) was significantly higher in twins than in singletons (6.55 ± 0.82 vs 5.62 ± 0.82 L/min, P = 0.007 at 20–23 weeks; 7.31 ± 0.74 vs 6.39 ± 0.74 L/min, P = 0.003 at 26–29 weeks; 7.50 ± 0.89 vs 6.68 ± 0.65 L/min, P = 0.015 at 30–33 weeks), whereas total vascular resistance (TVR) was lower (1005 ± 137 vs 1179 ± 199 dynes × s/cm5, P = 0.009 at 20–23 weeks; 924 ± 100 vs 1070 ± 138 dynes × s/cm5, P = 0.003 at 26–29 weeks; 929 ± 96 vs 1031 ± 122 dynes × s/cm5, P = 0.018 at 30–33 weeks). In both twins and singletons, CO showed a significant increase while TVR decreased significantly throughout the assessed pregnancy time period.

Conclusion

In twin gestation, maternal cardiac function apparently undergoes more profound changes compared with in singleton gestation, as testified by higher CO and lower TVR values at each stage of pregnancy starting from the mid‐trimester. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.
DFR: an efficient directional flooding‐based routing protocol in underwater sensor networks
Authors: Shin Dongseung , Hwang Daeyoup , Kim Dongkyun
Published: January 2011

Unlike terrestrial sensor networks, underwater sensor networks (UWSNs) have salient features such as a long propagation delay, narrow bandwidth, and high packet loss over links. Hence, path setup‐based routing protocols proposed for terrestrial sensor networks are not applicable because a large latency of the path establishment is observed, and packet delivery is not reliable in UWSNs. Even though routing protocols such as VBF (vector based forwarding) and HHVBF (hop‐by‐hop VBF) were introduced for UWSNs, their performance in terms of reliability deteriorates at high packet loss. In this paper, we therefore propose a directional flooding‐based routing protocol, called DFR, in order to achieve reliable packet delivery. DFR performs a so‐called controlled flooding, where DFR changes the number of nodes which participate in forwarding a packet according to their link quality. When a forwarding node has poor link quality to its neighbor nodes geographically advancing toward the sink, DFR allows more nodes to participate in forwarding the packet. Otherwise, a few nodes are enough to forward the packet reliably. In addition, we identify two types of void problems which can occur during the controlled flooding and introduce their corresponding solutions. Our simulation study using ns‐2 simulator proves that DFR is more suitable for UWSNs, especially when links are prone to packet loss. Copyright © 2011 John Wiley & Sons, Ltd.
Educational technology, reimagined
Authors: Eisenberg Michael
Published: January 2011

“Educational technology” is often equated in the popular imagination with “computers in the schools.” But technology is much more than merely computers, and education is much more than mere schooling. The landscape of child‐accessible technologies is blossoming in all sorts of directions: tools for communication, for physical construction and fabrication, and for human‐computer interaction. These new systems and artifacts allow educational designers to think much more creatively about when and where learning takes place in children's lives, both within and outside the classroom.
Augmenting your own reality: Student authoring of science‐based augmented reality games
Authors: Klopfer Eric , Sheldon Josh
Published: January 2011

Augmented Reality (AR) simulations superimpose a virtual overlay of data and interactions onto a real‐world context. The simulation engine at the heart of this technology is built to afford elements of game play that support explorations and learning in students' natural context—their own community and surroundings. In one of the more recent games, TimeLab 2100, players role‐play citizens of the early 22nd century when global climate change is out of control. Through AR, they see their community as it might be nearly one hundred years in the future. TimeLab and other similar AR games balance location specificity and portability—they are games that are tied to a location and games that are movable from place to place. Focusing students on developing their own AR games provides the best of both virtual and physical worlds: a more portable solution that deeply connects young people to their own surroundings. A series of initiatives has focused on technical and pedagogical solutions to supporting students authoring their own games.
Improving operational performance by influencing shopfloor behavior via performance management practices
Authors: de Leeuw Sander , van den Berg Jeroen P.
Published: January 2011

It is generally believed that companies applying performance management practices outperform those that do not measure and manage their performance. Studies examining the link between performance management and performance improvement implicitly assume that performance management affects behavior of individuals in an organization, which then facilitates the achievement of organizational goals. This study takes a step towards understanding this implicit assumption. We investigate how performance management practices relate to improvement in performance by influencing behavior of individuals. We focus on operational performance management, i.e. the definition and use of performance measures on the shopfloor in production and distribution. We use a survey among 102 companies to identify the relations between performance management practices, shopfloor behavior and improvement in performance. We identified three independent clusters of operator behavior that positively correlate with performance improvement: “Understanding”, “Motivation” and “Focus on Improvement”. We show that 17 out of the 20 performance management practices found in literature have a significant and positive relation with one or more clusters of operator behavior. We furthermore found that there is a positive correlation between the number of performance management practices applied and performance improvement, suggesting that it is not only which practices are applied but also how many. Recommendations emerging from this study enable managers to identify which behavioral changes are desired to improve performance and to select those performance management practices that positively influence the desired behavior.
ENHANCING WATER PRODUCTIVITY FOR POVERTY ALLEVIATION: ROLE OF CAPITALS AND INSTITUTIONS IN THE GANGA BASIN
Authors: CLEMENT FLORIANE , HAILESLASSIE AMARE , ISHAQ SABA , BLÜMMEL MICHAEL , MURTY M. V. R , SAMAD MADAR , DEY SANJIIB , DAS HIMANGSHU , KHAN M. A.
Published: January 2011

The concept of water productivity (WP) or ‘more crop per drop’ has been revived recently in international water debates. Its application has notably been extended from single crops to mixed farming systems, integrating both crops and livestock, with the wider objective of reducing poverty. Using evidence from the Ganga Basin, India, we discuss the relevance of this concept as a tool to guide interventions for livelihood improvement and poverty alleviation. We argue that WP studies would benefit from greater attention to the role of capitals, inequities and institutions. Firstly, it is crucial to acknowledge the heterogeneity of capitals and capabilities of farmers to make changes in their farming systems and practices and avoid one-fix-all interventions. Identifying pre-existing inequities in water access within and among communities will support better targeting of poor communities. WP interventions can either reinforce or reduce inter-household inequities within communities. We stress the need for assessment of institutional impacts of WP interventions on water access and development.
The future of animal production: improving productivity and sustainability
Authors: HUME D. A. , WHITELAW C. B. A. , ARCHIBALD A. L.
Published: January 2011

The challenge for the next 50 years is to increase the productivity of major livestock species to address the food needs of the world, while at the same time minimizing the environmental impact. The present review presents an optimistic view of this challenge. The completion of genome sequences, and high-density analytical tools to map genetic markers, allows for whole-genome selection programmes based on linkage disequilibrium for a wide spectrum of traits, simultaneously. In turn, it will be possible to redefine genetic prediction based on allele sharing, rather than pedigree relationships and to make breeding value predictions early in the life of the peak sire. Selection will be applied to a much wider range of traits, including those that are directed towards environmental or adaptive outcomes. In parallel, reproductive technologies will continue to advance to allow acceleration of genetic selection, probably including recombinationin vitro.Transgenesis and/or mutagenesis will be applied to introduce new genetic variation or desired phenotypes. Traditional livestock systems will continue to evolve towards more intensive integrated farming modes that control inputs and outputs to minimize the impact and improve efficiency. The challenges of the next 50 years can certainly be met, but only if governments reverse the long-term disinvestment in agricultural research.
Insurgency redux: Writings on Thailand's ongoing southern war
Authors: Askew Marc
Published: January 2011

Comprehending the origins, dynamics and solutions to the ongoing violence in southern Thailand's Muslim majority border provinces has proved to be a challenge, not only to successive Thai governments and security forces but also to scholars and other investigators. Insurgent-instigated attacks, now paralleled by and intertwined with more opportunistic forms of violence, have afflicted the border region for nearly seven years (as of late 2010), with no sign of ultimate abatement, despite a considerable investment of resources by the Thai state. Arguably under-reported by the world media, this conflict has nonetheless attracted its fair share of parachute journalism and superficial reportage by instant-experts, single-issue rights advocates, wide-eyed postgraduate researchers and assorted cranks. Many of them have been ensnared by local ‘fixers’ with their own agendas. Despite some notable exceptions, much academic research effort in the region itself has been hit-and-run. As Duncan McCargo emphasises: ‘this is a messy, awkward, in-your-face conflict’ (p. 188) — as such it demands a comparable ‘in-your-face’ and sustained field-based research effort, which, as he rightly notes, has been sadly lacking.
Complexity of spatial and temporal trends in metal concentrations in macroinvertebrate biomonitor species in the Severn Estuary and Bristol Channel
Authors: Bird David J. , Duquesne Sabine , Hoeksema Steeg D. , Langston William J. , Potter Ian C.
Published: January 2011

Cadmium, chromium, copper, nickel, lead and zinc concentrations in the bivalve molluscMacoma balthicaand the polychaete annelidsHediste diversicolorandArenicola marinawere measured, during winter and summer, at sites throughout the Severn Estuary and Bristol Channel. The mean concentration of each metal inA. marinawas greater in the lower Severn Estuary than in the far less contaminated outer Bristol Channel and the concentration of a given metal,e.g.Cr, in a species occasionally peaked at a site, reflecting local metal contamination. The concentrations of each metal in each of these biomonitor species almost invariably differed significantly among sites and often seasons and there were sometimes interactions between site and season. This indicates that the various factors that determine the concentration of a metal in a species operate in a complex manner and that their individual effects can vary among sites and/or seasons. The rank order of each metal concentration in each species at a site within the estuary frequently did not match the sequence for the concentration of that metal measured in the sediment at that site at the same time. This lack of correspondence is likely to be due, at least in part, to one or both of the following: (1) variations in the bioavailability of certain metals among sites due to differences in such features as the metal-binding properties of the sediments; (2) the effects of the constant transport and redistribution of the sediments and thus also of their associated trace metals by the very strong tidal action that characterizes the Severn Estuary. This would mean that single time measurements do not accurately reflect the overall trace metal environment to which the biomonitor organism had been exposed in the weeks/months prior to sampling. Marked differences in the concentrations of certain metals,e.g.Cu and Zn, in co-occurring biomarker species could frequently be related to differences between the ability of these species to regulate certain metals. Non-metric multi-dimensional scaling ordination and associated tests emphasize that the relationships between the concentrations of the various metals differed markedly among species and between sites and seasons in individual species and elucidated which metals contributed most to those differences. If the proposed scheme for harnessing tidal power in the Severn Estuary proceeds, the data in this paper provide a baseline for assessing the impact of such major changes on the bioavailability of trace metals in this estuary. This information will also be invaluable for predicting the changes likely to occur in other estuaries that become subjected to major structural changes.
Genetic manipulation of Neospora caninum to express the bradyzoite-specific protein NcSAG4 in tachyzoites
Authors: MARUGÁN-HERNÁNDEZ V. , ORTEGA-MORA L. M. , AGUADO-MARTÍNEZ A. , ÁLVAREZ-GARCÍA G.
Published: January 2011

Neospora caninum is an apicomplexan parasite and the aetiological agent of bovine neosporosis, one of the main causes of reproductive failure worldwide. We have generated 2 independent transgenic knock-in clones, Nc-1SAG4c1.1 and Nc-1SAG4c2.1, that express the bradyzoite stage-specific protein NcSAG4 in the tachyzoite stage. These clones have similar growth rates in vitro as the wild-type (WT) strain Nc-1. Studies in a cerebral mouse model of infection revealed a slightly lower rate of detection of the transgenic strains in brains during the chronic phase of infection. However, a pregnant mouse model of infection revealed a reduction in the virulence of the Nc-1SAG4c1.1 strain despite the same tachyzoite expression of NcSAG4 and a similar anti-NcSAG4 response displayed by mice inoculated with Nc-1 SAG4c1.1 or Nc-1 SAG4c2.1 parasites. This behaviour may be related to the reduced ability of the Nc-1SAG4c1.1 parasites to invade host cells, which was observed in in vitro assays. The apparent reduction in persistence and the high growth rate of the transgenic strains, together with their constitutive expression of the protein NcSAG4, may be useful features for future immunoprophylaxis trials based on a safe live attenuated vaccine.
A low-cost approach for self-calibration of climbing robots
Authors: Tavakoli Mahmoud , Marques Lino , de Almeida Aníbal T.
Published: January 2011

High accuracy is usually difficult to obtain with a robotic arm installed on a mobile base, since the errors of the base are transferred to the manipulator. This paper proposes a method to address this problem through integration of a self-calibration algorithm and low-cost sensors. The self-calibration algorithm might be repeated several times during execution of a mission by the robot and is only based on the internal sensors of the robot, meaning that external observers or reference point transceivers (e.g., ultrasonic transceivers) are not used. The proposed self-calibration system was implemented on a pole climbing robot and effectively improved the positioning accuracy of the climbing arm.
A self-replicating programmable constructor in a kinematic simulation environment
Authors: Stevens William M
Published: January 2011

Cellular automata can model the information processing aspects of a self-replicating programmable constructing system (SRPC), but these models do not contain any notion of material parts and are poor at modelling features of a system that depend upon the motion and connectivity of its components. Physical systems with thousands of parts have the disadvantage that they are time consuming to develop. To overcome these limitations, a simulation environment is presented at a level of abstraction that models motion and connectivity. An SRPC which takes a disorganised collection of parts as its input has been implemented in this environment.
Planning to fold multiple objects from a single self-folding sheet
Authors: An Byoungkwon , Benbernou Nadia , Demaine Erik D. , Rus Daniela
Published: January 2011

This paper considers planning and control algorithms that enable a programmable sheet to realize different shapes by autonomous folding. Prior work on self-reconfiguring machines has considered modular systems in which independent units coordinate with their neighbors to realize a desired shape. A key limitation in these prior systems is the typically many operations to make and break connections with neighbors, which lead to brittle performance. We seek to mitigate these difficulties through the unique concept of self-folding origami with a universal fixed set of hinges. This approach exploits a single sheet composed of interconnected triangular sections. The sheet is able to fold into a set of predetermined shapes using embedded actuation.

We describe the planning algorithms underlying these self-folding sheets, forming a new family of reconfigurable robots that fold themselves into origami by actuating edges to fold by desired angles at desired times. Given a flat sheet, the set of hinges, and a desired folded state for the sheet, the algorithms (1) plan a continuous folding motion into the desired state, (2) discretize this motion into a practicable sequence of phases, (3) overlay these patterns and factor the steps into a minimum set of groups, and (4) automatically plan the location of actuators and threads on the sheet for implementing the shape-formation control.
Multiple teachers: multiple gains?
Authors: Haddon Elizabeth
Published: January 2011

This paper explores the concept of instrumental/vocal learning when studying the same instrument or voice with more than one concurrent teacher. In this context, teachers may be working as a team, or one or both teachers may not know of the other's contribution to a student's learning. Qualitative data from music students and teachers at the University of York sheds some light on this often hidden learning context. This paper examines students’ reasons for studying with more than one teacher; their views on negotiating teacher demands; teacher–student–teacher dynamics; and assessment of the success of this context for learning. Teachers’ views are considered through discussion of their attitudes to this context, and their evaluation of its effect on their teaching. Findings suggest that although there may be problems for students regarding issues of teacher loyalty and dealing with conflicting advice, there are also many benefits including exposure to a greater range of musical and technical ideas and added pedagogical insight. There are also potential benefits for teachers if they are working as a team.