bluuebunny/crossref_metadata_2025 huggingface dataset:
LAMP‐2 Gene Expression in Peripheral Leukocytes Is Increased in Patients With Coronary Artery Disease
Authors: Wu Guanghua , Huang Jian , Wei Guanghe , Liu Lixin , Pang Shuchao , Yan Bo
Published: April 2011

Background:

Coronary artery disease (CAD) is a common complex disease that is caused by interaction between genetic and environmental factors. Accumulating evidence indicates that foam cells in the atherosclerotic plaques exhibit the characteristics of lysosomal storage diseases, namely lysosomal accumulation of indigested materials. In patients with lysosomal storage diseases, lysosomal accumulation of lipids and cholesterols in atherosclerotic plaque cells has been observed. However, the roles of lysosomal hydrolases and proteins in the pathogenesis of atherosclerosis and CAD remain unclear.

Hypothesis:

Lysosomal hydrolases and proteins may be involved in the pathogenesis of atherosclerosis and CAD by affecting lipid and cholesterol metabolism.

Methods:

Expression levels of LAMP‐2, a lysosomal membrane marker gene, in the peripheral leukocytes of CAD patients (n = 134) and age‐ and sex‐matched healthy controls (n = 80) were examined at transcription and protein levels with reverse transcriptase‐polymerase chain reaction and Western blot analyses, respectively. The results were compared between CAD patients and healthy controls.

Results:

LAMP‐2 gene expression and LAMp‐2 protein levels were significantly increased in the peripheral leukocytes of CAD patients, compared with healthy controls. Furthermore, multivariate logistic regression analyses revealed that CAD is significantly associated with LAMP‐2 gene expression levels (odds ratio [OR] 8.84, 95% confidence interval [CI]: 2.15–36.40, P = 0.003) or LAMP‐2 protein levels (OR 2.03, 95% CI: 1.15–3.59, P = 0.015).

Conclusions:

In CAD patients, LAMP‐2 gene expression in the peripheral leukocytes was significantly increased than were controls, which indicates lysosomal accumulation. These data suggest that insufficient lysosomal hydrolases and proteins may lead to abnormal lipid and cholesterol metabolism, which cause initiation and progression of atherosclerosis and CAD. © 2011 Wiley Periodicals, Inc.

This study was supported by National Science Foundation of China (No. 81070173) and Jining Medical College Affiliated Hospital. The authors have no other funding, financial relationships, or conflicts of interest to disclose.
Phosphorylated CXCR4 is associated with poor survival in adults with B‐acute lymphoblastic leukemia
Authors: Konoplev Sergej , Jorgensen Jeffrey L. , Thomas Deborah A. , Lin E , Burger Jan , Kantarjian Hagop M. , Andreeff Michael , Medeiros L. Jeffrey , Konopleva Marina
Published: March 2011

BACKGROUND:

CXC chemokine receptor 4 (CXCR4) is activated by phosphorylation (pCXCR4) and is essential for the migration of hematopoietic precursors to bone marrow. CXCR4 overexpression predicts a poor prognosis in patients with acute myeloid leukemia. Data regarding the prognostic impact of CXCR4 in patients with B‐acute lymphoblastic leukemia (B‐ALL) are sparse and limited to the pediatric population.

METHODS:

The authors analyzed CXCR4 and pCXCR4 expression in 54 adults with newly diagnosed B‐ALL. CXCR4 was assessed by flow cytometry (FC) and immunohistochemistry (IHC) using an anti‐CXCR4 antibody. pCXCR4 expression was assessed using an anti‐pCXCR4 antibody.

RESULTS:

The study group included 30 men and 24 women with a median age of 42 years (range, 17‐84 years). Philadelphia chromosome was present in 19 patients. The median follow‐up was 16 months (range, 17‐84 months). Forty‐nine patients had a complete response, and 12 patients relapsed with a median relapse free survival >120 weeks. Fifteen patients (28%) died with a median survival >125 weeks. CXCR4 detected by FC and IHC was highly correlated (P < .001). CXCR4 was not associated with clinical or laboratory findings or survival. In contrast, pCXCR4 was associated with higher leukocyte count (P = .006) and serum bilirubin level (P = .03). In multivariate analysis, pCXCR4 expression (P = .027), high serum creatinine level (P < .01), presence of the Philadelphia chromosome (P = .017), and late clinical response (P < .001) were associated with worse overall survival.

CONCLUSIONS:

The current results indicated that detection of the activated form of CXCR4, pCXCR4, provides independent prognostic information in adult patients with B‐ALL. Cancer 2011;. © 2011 American Cancer Society.
Localization of Cadm2a and Cadm3 proteins during development of the zebrafish nervous system
Authors: Hunter Paul R. , Nikolaou Nikolas , Odermatt Benjamin , Williams Philip R. , Drescher Uwe , Meyer Martin P.
Published: March 2011

Members of the Cadm/SynCAM/Necl/IGSF/TSLC family of cell adhesion molecules are known to have diverse functions during development of the nervous system, but information regarding their role during central nervous system (CNS) development in vivo is scarce. The rapid development of a relatively simple nervous system in larval zebrafish makes them a highly tractable model organism for studying gene function during nervous system development. An essential prerequisite for functional studies is a description of protein localization. To address this we have generated subtype‐specific antibodies to two members of the zebrafish cell adhesion molecule family: cadm2a and cadm3. Using these novel antibodies we show that cadm3 and cadm2a are expressed throughout the nervous system of larval stage zebrafish. Particularly striking, and largely nonoverlapping expression of cadm2a and cadm3 is observed in the developing retina and spinal cord. Using in vitro binding assays we show that cadm2a and cadm3 bind heterophilically and preferentially to cadm1 and cadm4, respectively. These binding preferences are very similar to those seen for tetrapod Cadms but our study of protein localization suggests novel and diverse functions of cadms during nervous system development. J. Comp. Neurol. 519:2252–2270, 2011. © 2011 Wiley‐Liss, Inc.
Paternal experience suppresses adult neurogenesis without altering hippocampal function in Peromyscus californicus
Authors: Glasper Erica R. , Kozorovitskiy Yevgenia , Pavlic Ashley , Gould Elizabeth
Published: March 2011

Paternal care is rare among mammals, occurring in ≈6% of species. California mice (Peromyscus californicus) are unusual; fathers participate extensively in raising their young and display the same components of parental care as mothers, with the exception of nursing. Parenting is a complex experience, having stressful and enriching aspects. The hippocampus is sensitive to experience and responds to both stress and environmental enrichment with changes in structure and function. In rats, where females care exclusively for offspring, parenting is associated with suppressed hippocampal adult neurogenesis. Since this effect has been causally linked to lactation, it is unlikely that fathers would show a similar change. To investigate this issue, we examined adult neurogenesis in the hippocampus of California mouse fathers compared to males without pups and observed reduced adult neurogenesis. Similar effects were found in California mouse mothers. Next, we investigated whether behaviors linked to the hippocampus, namely, object recognition and novelty‐suppressed feeding, were altered in fathers, and observed no substantial changes. During caregiving, suppressed adult neurogenesis does not appear to be related to changes in behaviors associated with the hippocampus, although it is possible that there are other effects on hippocampal function. function. J. Comp. Neurol. 519:2271–2281, 2011. © 2011 Wiley‐Liss, Inc.
Spatiotemporal distribution of tenascin‐R in the developing human cerebral cortex parallels neuronal migration
Authors: El Ayachi Ikbale , Fernandez Carla , Baeza Nathalie , De Paula André Maues , Pesheva Penka , Figarella‐Branger Dominique
Published: March 2011

Tenascin‐R is an extracellular matrix glycoprotein that is restricted to the central nervous system, where it acts as a multifunctional and versatile molecule. We report spatial and temporal distribution of tenascin‐R in the developing human cerebral cortex for the first time. At 7.5 gestational weeks (GW), tenascin‐R was expressed in a restricted area of the basal telencephalon. At 9.5 and 11 GW, it showed a unique double band expression pattern that delineated the boundaries of the future cortical plate. From 14 to 30 GW, tenascin‐R labeling extended to the whole cortex from the deep layers toward the marginal zone with an inside‐to‐outside progression pattern reminiscent of neuronal migration. Moreover, tenascin‐R labeling initially appeared in the form of thin, straight, or slightly tortuous intercellular processes directed toward the surface in parallel with the axis of neuronal migration. At the end of pregnancy and at adulthood, diffuse and homogeneous immunolabeling of the whole cortex thickness was observed. The striatum and thalamus were faintly positive for TNR as early as 14 GW, and this positivity intensified with brain maturation. At all developmental stages, the germinative zone, the corpus callosum, the anterior commissure, and the internal capsule appeared clearly negative for tenascin‐R immunostaining whereas the adjacent parenchyma was immunopositive. Our results show that tenascin‐R expression is tightly regulated in a spatiotemporal manner during brain development, especially cortical plate formation. Its pattern of expression suggests a role for tenascin‐R in corticogenesis. J. Comp. Neurol. 519:2379–2389, 2011. © 2011 Wiley‐Liss, Inc.
Close correlation between the birth date of purkinje cells and the longitudinal compartmentalization of the mouse adult cerebellum
Authors: Namba Kazunori , Sugihara Izumi , Hashimoto Mitsuhiro
Published: March 2011

The adult cerebellum is organized into longitudinal compartments that are revealed by specific axonal projections (olivocerebellar and corticonuclear projections). These compartments in the adult cerebellum are closely correlated with the striped expression of zebrin II (aldolase C), a late‐onset marker of Purkinje cells. Similarly, the embryonic cerebellum is organized into longitudinal compartments that are revealed by striped expression of other genes (early‐onset markers). The cerebellar compartments are thought to be the basic and functional subdivisions of the cerebellum. However, the relationship between the embryonic (early‐onset) and the adult (late‐onset) compartments has remained unknown, because the pattern of the embryonic compartments is distinct from that of the adult compartments. To examine this issue, we labeled Purkinje cells (PCs) born at embryonic day (E) 10.5, E11.5, and E12.5 by using an adenoviral vector and traced their fated positions in the adult cerebellum. By comparing the striped distribution of each cohort of birth date‐related PCs with the striped pattern of zebrin II immunoreactivity (zebrin II bands) in the entire adult cerebellum, we found that the striped distribution of PCs correlated strikingly with zebrin II bands. Generally, a single early‐onset compartment was transformed directly into a single late‐onset compartment. Therefore, our observation also indicated the close correlation between the compartments formed by birth date‐related PCs and olivocerebellar projections. Furthermore, we found that the cerebellum was composed of three units showing lateral‐to‐medial developmental gradients, as revealed by the birth dates of PCs. The results suggest that PC birth dates play an important role in organizing cerebellar compartmentalization. J. Comp. Neurol. 519:2594–2614, 2011. © 2011 Wiley‐Liss, Inc.
Gas Exchange Consequences of Left Heart Failure
Authors: Robertson H. Thomas
Published: April 2011

This review explores the pathophysiology of gas exchange abnormalities arising consequent to either acute or chronic elevation of pulmonary venous pressures. The initial experimental studies of acute pulmonary edema outlined the sequence of events from lymphatic congestion with edema fluid to frank alveolar flooding and its resultant hypoxemia. Clinical studies of acute heart failure (HF) suggested that hypoxemia was associated only with the final stage of alveolar flooding. However, in patients with chronic heart failure and normal oxygenation, hypoxemia could be produced by the administration of potent pulmonary vasodilators, suggesting that hypoxic pulmonary vasoconstriction is an important reflex for these patients. Patients with chronic left HF commonly manifest a reduced diffusing capacity, an abnormality that appears to be a consequence of chronic elevation of left atrial pressure. That reduction in diffusing capacity does not appear to be primarily attributable to increases in lung water but is improved by any sustained treatment that improves overall cardiac function. Patients with heart failure may also manifest an abnormally elevated

during exercise, and that exercise ventilation abnormality arises as a consequence of both alveolar hyperventilation and elevated physiologic dead space. That elevated exercise

in an HF patient has proven to be a powerful predictor of an adverse outcome and hence it has received sustained attention in the HF literature. At least three of the classes of drugs used to treat HF will normalize the exercise

, suggesting that the excessive ventilation response may be linked to elevated sympathetic activity. © 2011 American Physiological Society.
Compr Physiol
1:621‐634, 2011.
Inert Gas Transport in Blood and Tissues
Authors: Baker A. Barry , Farmery Andrew D.
Published: April 2011

This article establishes the basic mathematical models and the principles and assumptions used for inert gas transfer within body tissues—first, for a single compartment model and then for a multicompartment model. From these, and other more complex mathematical models, the transport of inert gases between lungs, blood, and other tissues is derived and compared to known experimental studies in both animals and humans. Some aspects of airway and lung transfer are particularly important to the uptake and elimination of inert gases, and these aspects of gas transport in tissues are briefly described. The most frequently used inert gases are those that are administered in anesthesia, and the specific issues relating to the uptake, transport, and elimination of these gases and vapors are dealt with in some detail showing how their transfer depends on various physical and chemical attributes, particularly their solubilities in blood and different tissues. Absorption characteristics of inert gases from within gas cavities or tissue bubbles are described, and the effects other inhaled gas mixtures have on the composition of these gas cavities are discussed. Very brief consideration is given to the effects of hyper‐ and hypobaric conditions on inert gas transport. © 2011 American Physiological Society.Compr Physiol1:569‐592, 2011.
Mechanotransduction
Authors: Tschumperlin Daniel J.
Published: April 2011

Physical forces are central players in development and morphogenesis, provide an ever‐present backdrop influencing physiological functions, and contribute to a variety of pathologies. Mechanotransduction encompasses the rich variety of ways in which cells and tissues convert cues from their physical environment into biochemical signals. These cues include tensile, compressive and shear stresses, and the stiffness or elastic modulus of the tissues in which cells reside. This article focuses on the proximal events that lead directly from a change in physical state to a change in cell‐signaling state. A large body of evidence demonstrates a prominent role for the extracellular matrix, the intracellular cytoskeleton, and the cell matrix adhesions that link these networks in transduction of the mechanical environment. Recent work emphasizes the important role of physical unfolding or conformational changes in proteins induced by mechanical loading, with examples identified both within the focal adhesion complex at the cell‐matrix interface and in extracellular matrix proteins themselves. Beyond these adhesion and matrix‐based mechanisms, classical and new mechanisms of mechanotransduction reside in stretch‐activated ion channels, the coupling of physical forces to interstitial autocrine and paracrine signaling, force‐induced activation of extracellular proteins, and physical effects directly transmitted to the cell's nucleus. Rapid progress is leading to detailed delineation of molecular mechanisms by which the physical environment shapes cellular signaling events, opening up avenues for exploring how mechanotransduction pathways are integrated into physiological and pathophysiological cellular and tissue processes. © 2011 American Physiological Society.Compr Physiol1:1057‐1073, 2011.
Complexity and Emergent Phenomena
Authors: Suki Béla , Bates Jason H.T. , Frey Urs
Published: April 2011

Complex biological systems operate under non‐equilibrium conditions and exhibit emergent properties associated with correlated spatial and temporal structures. These properties may be individually unpredictable, but tend to be governed by power‐law probability distributions and/or correlation. This article reviews the concepts that are invoked in the treatment of complex systems through a wide range of respiratory‐related examples. Following a brief historical overview, some of the tools to characterize structural variabilities and temporal fluctuations associated with complex systems are introduced. By invoking the concept of percolation, the notion of multiscale behavior and related modeling issues are discussed. Spatial complexity is then examined in the airway and parenchymal structures with implications for gas exchange followed by a short glimpse of complexity at the cellular and subcellular network levels. Variability and complexity in the time domain are then reviewed in relation to temporal fluctuations in airway function. Next, an attempt is given to link spatial and temporal complexities through examples of airway opening and lung tissue viscoelasticity. Specific examples of possible and more direct clinical implications are also offered through examples of optimal future treatment of fibrosis, exacerbation risk prediction in asthma, and a novel method in mechanical ventilation. Finally, the potential role of the science of complexity in the future of physiology, biology, and medicine is discussed. © 2011 American Physiological Society.Compr Physiol1:995‐1029, 2011.
Mechanics of the Nucleus
Authors: Lammerding Jan
Published: April 2011

The nucleus is the distinguishing feature of eukaryotic cells. Until recently, it was often considered simply as a unique compartment containing the genetic information of the cell and associated machinery, without much attention to its structure and mechanical properties. This article provides compelling examples that illustrate how specific nuclear structures are associated with important cellular functions, and how defects in nuclear mechanics can cause a multitude of human diseases. During differentiation, embryonic stem cells modify their nuclear envelope composition and chromatin structure, resulting in stiffer nuclei that reflect decreased transcriptional plasticity. In contrast, neutrophils have evolved characteristic lobulated nuclei that increase their physical plasticity, enabling passage through narrow tissue spaces in their response to inflammation. Research on diverse cell types further demonstrates how induced nuclear deformations during cellular compression or stretch can modulate cellular function. Pathological examples of disturbed nuclear mechanics include the many diseases caused by mutations in the nuclear envelope proteins lamin A/C and associated proteins, as well as cancer cells that are often characterized by abnormal nuclear morphology. In this article, we will focus on determining the functional relationship between nuclear mechanics and cellular (dys‐)function, describing the molecular changes associated with physiological and pathological examples, the resulting defects in nuclear mechanics, and the effects on cellular function. New insights into the close relationship between nuclear mechanics and cellular organization and function will yield a better understanding of normal biology and will offer new clues into therapeutic approaches to the various diseases associated with defective nuclear mechanics. © 2011 American Physiological Society.Compr Physiol1:783‐807, 2011.
Regulation of Mitochondrial Biogenesis and GLUT4 Expression by Exercise
Authors: Holloszy John O.
Published: April 2011

Endurance exercise training can induce large increases mitochondria and the GLUT4 isoform of the glucose transporter in skeletal muscle. For a long time after the discovery in the 1960s that exercise results in an increase in muscle mitochondria, there was no progress in elucidation of the mechanisms involved. The reason for this lack of progress was that nothing was known regarding how expression of the genes‐encoding mitochondrial proteins is coordinately regulated. This situation changed rapidly after discovery of transcription factors that control transcription of genes‐encoding mitochondrial proteins and, most importantly, the discovery of peroxisome proliferator‐gamma coactivator‐1α (PGC‐1α). This transcription coactivator binds to and activates transcription factors that regulate transcription of genes‐encoding mitochondrial proteins. Thus, PGC‐1α activates and coordinates mitochondrial biogenesis. It is now known that exercise rapidly activates and induces increased expression of PGC‐1α. The exercise‐generated signals that lead to PGC‐1α activation and increased expression are the increases in cytosolic Ca2+and decreases in ATP and creatine phosphate (∼P). Ca2+mediates its effect by activating CAMKII, while the decrease in ∼P mediates its effect via activation of AMPK. Expression of the GLUT4 isoform of the glucose transporter is regulated in parallel with mitochondrial biogenesis via the same signaling pathways. This review describes what is known regarding the regulation of mitochondrial biogenesis and GLUT4 expression by exercise. A major component of this review deals with the physiological and metabolic consequences of the exercise‐induced increase in mitochondria and GLUT4. © 2011 American Physiological Society.Compr Physiol1:921‐940, 2011.
Molecular Physiology of the Medullary Collecting Duct
Authors: Fenton Robert A. , Praetorius Jeppe
Published: April 2011

The mammalian kidney is responsible for a multitude of homeostatic functions, which are mediated by both structural and functional diversity along the renal tubule. In this article, we focus on the major functions of the terminal portion of the renal tubule, the medullary collecting duct system. The role of the medullary collecting ducts in determining the composition of the final urine through controlled water, sodium, chloride, potassium and urea reabsorption, ammonia transport, and acid‐base homeostasis is discussed. The molecular identity of the major channels and transporters that contribute to medullary collecting duct function are described in detail, including; aquaporins, urea transporters, the epithelial sodium channel (ENaC), the Na,K‐ATPase, H‐ATPase, Rh glycoproteins, and sodium bicarbonate transporters. Knowledge gained from studies in knockout mice is also discussed. © 2011 American Physiological Society.Compr Physiol1:1031‐1056, 2011.
Floating zone growth of eutectic Srn+1RunO3n+1 crystals
Authors: Fittipaldi R. , Granata V. , Vecchione A.
Published: April 2011

A novel route to engineer Sr2RuO4/Sr3Ru2O7 and Sr3Ru2O7/Sr4Ru3O10 natural junctions has been successfully pursued by eutectic solidification in a double‐mirror optical floating zone furnace in the flux feeding floating zone configuration with Ru self‐flux. The synthesis procedure of the polycrystalline rod is found to be a critical factor for the crystal growth. Both eutectic systems grow in the [100] direction and cleave in the a –b plane as the single phase crystals. Extensive XRD and SEM studies show that the nature of the eutectic solidification enables the displacement of the two phases in an ordered lamellar pattern piling up along the crystallographic c‐axis. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Solvothermal synthesis of ZnS[C2H4(NH2)2]0.5 nanosheets
Authors: Mosca R. , Ferro P. , Calestani D. , Nasi L. , Besagni T. , Licci F.
Published: April 2011

ZnS(en)0.5 complex (en=ethylenediamine) can be synthesized by solvothermal route as thin sheet‐like crystals using en as the single solvent. We studied the influence of the main synthesis parameters (i.e. temperature, pressure, time, reactant type and concentration) on the compound crystallization kinetics to achieve control on shape and dimensions of the ZnS(en)0.5 nanoplatelets. We achieved a significant reduction of the platelet dimensions, while maintaining acceptable yield, by using a single piece of metal zinc as the Zn2+ source. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pulse current generator for driving tubular field emission lamp based on DCM flyback converter
Authors: Lin Chang‐Hua , Wang Chien‐Ming , Hung Min‐Hsuan , Lu Ying
Published: April 2011

This paper proposes a pulse current generator operated in discontinuous conduction mode for driving a tubular field emission lamp (TFEL). The proposed system based on flyback topology can provide pulse power driving to eliminate the temperature rise and arcing phenomenon caused by the traditional constant voltage driving. Therefore, both the lighting efficiency and lamp lifespan are improved. In this paper, an equivalent model of the TFEL is constructed to exhibit its capacitive characteristics. Moreover, the circuit configuration and each operation mode in a switching cycle are also described. And then a complete design considerations and mathematical model are discussed in detail. All the experimental results agree with the computer simulations to verify the theoretical predictions. Copyright © 2011 John Wiley & Sons, Ltd.
Rank‐based dynamic frequency hopping without strict coordination in IEEE 802.22 WRAN system
Authors: Kinoshita Harumasa , Tachibana Takuji , Sugimoto Kenji
Published: April 2011

In IEEE 802.22 wireless regional area networks (WRAN), it is indispensable to prevent the in‐use channel from interfering with incumbent services such as digital TV. To achieve this end, in this paper, we propose a dynamic frequency hopping based on rank accounting. In this method, a base station utilizes a ranking database where a rank of a channel which is used frequently is high. Each base station uses an idle channel whose rank is the highest based on the database, and hence this can reduce the number of channels which are used for the data transmission. Moreover, the proposed method performs interference avoidance processes. The proposed method does not require a strict coordination for base stations. We evaluate the performance of the proposed method with simulation. Numerical examples show that the failure probability of the channel switching for the proposed method is smaller than that for the conventional random method. It is also shown that the number of channels that are used for the data transmission can be reduced by using the proposed method. Finally, we investigate the performance of the proposed method in some situations. Copyright © 2011 John Wiley & Sons, Ltd.
Evaluation of ecohydrologic model parsimony at local and regional scales in a semiarid grassland ecosystem
Authors: Istanbulluoglu Erkan , Wang Tiejun , Wedin David A.
Published: March 2011

In this study, a zero‐dimensional land surface model based on a vertically averaged representation of soil moisture in the root‐zone is coupled with grass dynamics represented by live and dead biomass pools. Five variants of the model combined the different time steps (daily vs interstorm), representations of potential evapotranspiration (PET), and constant versus variable water use efficiency (WUE). Model results were compared with field observations of soil moisture, live and dead biomass, and leaf area index (LAI) from a long‐term experiment in the Nebraska Sand Hills (NSH), USA. Results show that the simplest model configuration using a constant WUE term, PET represented from a cosine function, and an inter‐storm model time step can capture grass dynamics nearly as well as daily model simulations with variable WUE. The model is then applied across the NSH to investigate the performance of the model across a climate gradient, and identify parameters that can be calibrated to improve regional predictions. For this purpose a senescence parameter that controls the decay of live aboveground vegetation is further calibrated at 14 different locations across NSH. Model calibrations revealed the dependence of the senescence parameter to regional variations in annual precipitation. Relating the senescence coefficient to annual precipitation using an empirical equation improved the model predictions at the regional scale, and revealed a strong climatic control on grass LAI. Finally, the model is tested against some existing empirical equations that relate annual grassland productivity to annual precipitation and evapotranspiration. Copyright © 2011 John Wiley & Sons, Ltd.
Role of NKG2D and its ligands in the anti‐infectious activity of Vγ9Vδ2 T cells against intracellular bacteria
Authors: Bessoles Stéphanie , Ni Ming , Garcia‐Jimenez Sara , Sanchez Françoise , Lafont Virginie
Published: March 2011

Human Vγ9Vδ2 T cells play a crucial role in early immune response to intracellular pathogens. Their number is drastically increased in the peripheral blood of patients during the acute phase of brucellosis. In vitro, Vγ9Vδ2 T cells exhibit strong cytolytic activity against Brucella‐infected cells and impair intracellular growth of Brucella suis in autologous macrophages. Vγ9Vδ2 T cells use cell contact‐dependent mechanisms such as the release of lytic granules and Fas‐mediated signals to lyse infected macrophages and decrease the development of intracellular Brucella. Although the involvement of the T‐cell receptor (TCR) in the triggering of these responses is known, other surface receptors can modulate Vγ9Vδ2 T‐cell response. In this study, we have investigated a potential role of NKG2D and its ligands in the anti‐infectious activity of human Vγ9Vδ2 T cells against B. suis. We show that the recruitment of NKG2D by its ligands is sufficient to induce cytokine production and the release of lytic granules through PI3K‐dependent pathways, but can also increase the TCR‐triggered responses of Vγ9Vδ2 T cells. We also demonstrate that the interaction between NKG2D and its main ligand expressed on Brucella‐infected macrophages, UL16‐binding protein 1 (ULBP1), is involved in the inhibition of bacterium development. Altogether, these results suggest a direct contribution of NKG2D and its ligands to the anti‐infectious activity of Vγ9Vδ2 T cells.
Spectroscopic, Electrochemical, and DFT Studies of Oxo‐Centered Triruthenium Cluster Complexes with a Bis(tridentate) Triazine Ligand
Authors: Dai Feng‐Rong , Wu Yu‐Hui , Zhang Li‐Yi , Li Bin , Shi Lin‐Xi , Chen Zhong‐Ning
Published: April 2011

Oxo‐centered triruthenium–acetate complexes with a tridentate or bis(tridentate) triazine ligand have been prepared by the reaction of [Ru3O(OAc)6(py)2(CH3OH)]+ ([1]+) with a triazine ligand [3‐(2‐pyridyl)‐1,2,4‐triazine (pytz), 3‐(2‐pyrimidinyl)‐1,2,4‐triazine (pmtz), or 5,5′,6,6′‐tetramethyl‐3,3′‐bi‐1,2,4‐triazine (bdmt)]. The dimeric complex [{Ru3O(OAc)5(py)2}2(μ4‐pmtz)]2+ ([5]2+), an intercluster mixed‐valence complex ([Ru3III,III,II‐pmtz‐Ru3III,III,III]2+) containing an asymmetric bis(tridentate) pmtz ligands involved in both μ‐η1(N),η2(N,N) and orthometalated μ‐η1(C),η2(N,N) bonding modes, was prepared by substitution of a bridging acetate in the parent Ru3O(OAc)6 cluster core. Chemical or electrochemical reduction or oxidation of [5]2+ gave one‐electron reduced product [5a]+ or oxidized species [5b]3+, respectively. It is demonstrated that substitution of the bridging acetate by a triazine ligand has a remarkable impact on the electronic and redox characteristics of the triruthenium cluster derivatives. Electrochemical, UV/Vis/NIR spectra, and DFT computational studies demonstrated that there is a distinct cluster–cluster interaction between the two triruthenium cluster moieties across an asymmetric bridging bis(tridentate) triazine in the dimeric triruthenium cluster complex [5]2+.
Direct numerical simulation of electrokinetic translocation of a cylindrical particle through a nanopore using a Poisson–Boltzmann approach
Authors: Ai Ye , Qian Shizhi
Published: March 2011

Nanopore‐based sensing of single molecules is based on a detectable change in the ionic current arising from the electrokinetic translocation of individual nanoparticles through a nanopore. In this study, we propose a continuum‐based model to investigate the dynamic electrokinetic translocation of a cylindrical nanoparticle through a nanopore and the corresponding ionic current response. It is the first time to simultaneously solve the Poisson–Boltzmann equation for the ionic concentrations and the electric field contributed by the surface charges of the nanopore and the nanoparticle, the Laplace equation for the externally applied electric field, and the modified Stokes equations for the flow field using an arbitrary Lagrangian–Eulerian method. Current blockade due to the particle translocation is predicted when the electric double layers (EDLs) of the particle and the nanopore are not overlapped, which is in qualitative agreement with existing experimental observations. Effects due to the electric field intensity imposed, the EDL thickness, the nanopore's surface charge, the particle's initial orientation and lateral offset from the nanopore's centerline on the particle translocation including both translation and rotation, and the ionic current response are comprehensively investigated. Under a relatively low electric field imposed, the particle experiences a significant rotation and a lateral movement. However, the particle is aligned with its longest axis parallel to the local electric field very quickly due to the dielectrophoretic effect when the external electric field is relatively high.
Preinvasive colorectal lesion transcriptomes correlate with endoscopic morphology (polypoid vs. nonpolypoid)
Authors: Cattaneo Elisa , Laczko Endre , Buffoli Federico , Zorzi Fausto , Bianco Maria Antonia , Menigatti Mirco , Bartosova Zdena , Haider Ritva , Helmchen Birgit , Sabates‐Bellver Jacob , Tiwari Amit , Jiricny Josef , Marra Giancarlo
Published: April 2011

Improved colonoscopy is revealing precancerous lesions that were frequently missed in the past, and ∼30% of those detected today have nonpolypoid morphologies ranging from slightly raised to depressed. To characterize these lesions molecularly, we assessed transcription of 23,768 genes in 42 precancerous lesions (25 slightly elevated nonpolypoid and 17 pedunculated polypoid), each with corresponding samples of normal mucosa. Nonpolypoid versus polypoid morphology explained most gene expression variance among samples; histology, size, and degree of dysplasia were also linked to specific patterns. Expression changes in polypoid lesions frequently affected cell‐cycling pathways, whereas cell‐survival dysregulation predominated in nonpolypoid lesions. The latter also displayed fewer and less dramatic expression changes than polypoid lesions. Paradigmatic of this trend was progressive loss through the normal > nonpolypoid > polypoid > cancer sequence of TMIGD1 mRNA and protein. This finding, along with TMIGD1 protein expression patterns in tissues and cell lines, suggests that TMIGD1 might be associated with intestinal‐cell differentiation. We conclude that molecular dysregulation in slightly elevated, nonpolypoid, precancerous colorectal lesions may be somewhat less severe than that observed in classic adenomatous polyps.
Developing channel and floodplain dimensions with limited data: a case study in the Amazon Basin
Authors: Beighley R. Edward , Gummadi Venkat
Published: March 2011

This research builds on the concept of hydraulic geometry and presents a methodology for estimating bankfull discharge and the hydraulic geometry coefficients and exponents for a station using limited data; only stage‐discharge and Landsat imagery. The approach is implemented using 82 streamflow gauging locations in the Amazon Basin. Using the estimated values for the hydraulic geometry relations, bankfull discharge, discharge data above bankfull and upstream drainage area at each site, relationships for estimating channel and floodplain characteristics as a function of drainage area are developed. Specifically, this research provides relationships for estimating bankfull discharge, bankfull depth, bankfull width, and floodplain width as a function of upstream drainage area in the Amazon Basin intended for providing reasonable cross‐section estimates for large scale hydraulic routing models. The derived relationships are also combined with a high resolution drainage network to develop relationships for estimating cumulative upstream channel lengths and surface areas as a function of the specified minimum channel width ranging from 2 m to 1 km (i.e. threshold drainage areas ranging from 1 to 431,000 km2). At the finest resolution (i.e. all channels greater than 2 m or a threshold area of 1 km2), the Amazon Basin contains approximately 4.4 million kilometers of channels with a combined surface area of 59,700 km2. The intended use of these relationships is for partitioning total floodable area (channels versus lakes and floodplain lakes) obtained from remote sensing for biogeochemical applications (e.g. quantifying CO2 evasion in the Amazon Basin). Copyright © 2011 John Wiley & Sons, Ltd.
Sources and fate of chiral organochlorine pesticides in western U.S. National Park ecosystems
Authors: Genualdi Susan A , Hageman Kimberly J , Ackerman Luke K , Usenko Sascha , Massey Simonich Staci L
Published: April 2011

The enantiomer fractions (EFs) of alpha-hexachlorocyclohexane (α-HCH), cis-, trans-, and oxychlordane, and heptachlor epoxide were measured in 73 snow, fish, and sediment samples collected from remote lake catchments, over a wide range of latitudes, in seven western U.S. National Parks/Preserves to investigate their sources, fate, accumulation and biotransformation in these ecosystems. The present study is novel because these lakes had no inflow or outflow, and the measurement of chiral organochlorine pesticides (OCPs) EFs in snowpack from these lake catchments provided a better understanding of the OCP sources in the western United States, whereas their measurement in fish and sediment provided a better understanding of their biotic transformations within the lake catchments. Nonracemic α-HCH was measured in seasonal snowpack collected from continental U.S. National Parks, and racemic α-HCH was measured in seasonal snowpack collected from the Alaskan parks, suggesting the influence of regional sources to the continental U.S. parks and long-range sources to the Alaskan parks. The α-HCH EFs measured in trout collected from the lake catchments were similar to the α-HCH EFs measured in seasonal snowpack collected from the same lake catchments, suggesting that these fish did not biotransform α-HCH enantioselectively. Racemic cis-chlordane was measured in seasonal snowpack and sediment collected from Sequoia, indicating that it had not undergone significant enantioselective biotransformation in urban soils since its use as a termiticide in the surrounding urban areas. However, nonracemic cis-chlordane was measured in seasonal snowpack and sediments from the Rocky Mountains, suggesting that cis-chlordane does undergo enantioselective biotransformation in agricultural soils. The trout from these lakes showed preferential biotransformation of the (+)-enantiomer of cis-chlordane and the (−)-enantiomer of trans-chlordane. Environ. Toxicol. Chem. 2011; 30:1533–1538. © 2011 SETAC
Juvenile green frog (Rana clamitans) predatory ability not affected by exposure to carbaryl at different times during larval development
Authors: Davis Melanie J , Kleinhenz Peter , Boone Michelle D
Published: April 2011

Larval exposure to pesticides can occur at different times during development and can negatively impact amphibian fitness. We examined the effects of larval green frog (Rana clamitans) exposure to carbaryl at 2, 4, 8, or 16 weeks of development on juvenile predatory ability. We did not find evidence that predatory ability was affected by exposure to carbaryl, which suggests that carbaryl does not have latent effects on the predatory performance of green frogs in subsequent life stages. Environ. Toxicol. Chem. 2011; 30:1618–1620. © 2011 SETAC
An efficient low‐dissipative WENO filter scheme
Authors: Kang Lei , Lee Chun‐Hian
Published: April 2011

This paper presents a simple and efficient procedure developed for tracing discontinuities in flow fields. Numerical experiments are carried out to test the new sensor coupled with the associated nonlinear WENO dissipation filter developed to suppress the numerical dissipation. The tests show that, for a problem containing shocks and vortices, the implementation of the new sensor and an optimized WENO scheme can obtain a stable and highly resolved solution. The numerical experiments demonstrated that the new filter scheme performs efficiently both in parallel and serial running for one‐dimensional inviscid flow problems. Direct numerical simulation of a Mach 5 turbulent boundary layer over a flat plate was carried out to demonstrate the applicability of the scheme to the DNS practices. Copyright © 2011 John Wiley & Sons, Ltd.
Ganz schön turbulent …
Authors: Czarske Jürgen W.
Published: March 2011

Messtechnik: Ein neuartiges Verfahren erfasst mikroskopische und makroskopische Strömungen berührunglos und hoch präzise. Der „Laser‐Doppler‐Geschwindigkeitsprofilsensor”︁ hat enormes Anwendungspotenzial für Wissenschaft und Technik.
Entscheidung mit Köpfchen
Authors: Weber Bernd
Published: March 2011

Ob im Autosalon oder vor dem Kühlregal: Überall hat der Mensch die Qual der Wahl. Was geschieht in seinem Gehirn, wenn er diese oder jene Alternative wählt? Mit bildgebenden Verfahren will die Neuroökonomie die biologischen Grundlagen des Verhaltens besser verstehen.
Gleich und gleich gesellt sich gern
Authors: Küppers Brigitte
Published: March 2011

Erst schauten sie der Natur auf die Finger, dann synthetisierten sie nach deren Vorbild Ketten von Molekülen, die alle dieselbe Länge und Struktur haben und sich sogar selbst vervielfältigen können. Nun legen Polymerchemiker damit die Grundlagen für neue interessante Werkstoffe.
Study of Methanol‐tolerant Oxygen Reduction Reaction at Pt–Bi/C Bimetallic Nanostructured Catalysts
Authors: Remona A. M. , Phani K. L. N.
Published: April 2011

The nanostructured platinum–bismuth catalysts supported on carbon (Pt3Bi/C, PtBi/C and PtBi3/C) were synthesised by reducing the aqueous metal ions using sodium borohydride (NaBH4) in presence of a microemulsion. The amount of metal loading on carbon support was found to be 10 wt.‐%. The catalyst materials were characterised by X‐ray diffraction (XRD), X‐ray fluorescence (XRF), transmission electron microscope (TEM) and electroanalytical techniques. The Pt3Bi/C, PtBi/C and PtBi3/C catalysts showed higher methanol tolerance, catalytic activity for oxygen reduction reaction (ORR) than Pt/C of same metal loading. The electrochemical stability of these nano‐sized catalyst materials for methanol tolerance was investigated by repetitive cycling in the potential range of –250 to 150 mVMSE. Bi presents an interesting system to have a control over the activity of the surface for MOR and ORR. All Pt–Bi/C catalysts exhibited higher mass activities for oxygen reduction (1–1.5 times) than Pt/C. It was found that PtBi/C catalyst exhibits better methanol‐tolerance than the other catalysts.
Hippocampal morphology in lithium and non‐lithium‐treated bipolar I disorder patients, non‐bipolar co‐twins, and control twins
Authors: van Erp Theo G.M. , Thompson Paul M. , Kieseppä Tuula , Bearden Carrie E. , Marino Alexandria C. , Hoftman Gil D. , Haukka Jari , Partonen Timo , Huttunen Matti , Kaprio Jaakko , Lönnqvist Jouko , Poutanen Veli‐Pekka , Toga Arthur W. , Cannon Tyrone D.
Published: March 2011

Background: Bipolar I disorder is a highly heritable psychiatric illness with undetermined predisposing genetic and environmental risk factors. We examined familial contributions to hippocampal morphology in bipolar disorder, using a population‐based twin cohort design. Methods: We acquired high‐resolution brain MRI scans from 18 adult patients with bipolar I disorder [BPI; mean age 45.6 ± 8.69 (SD); 10 lithium‐treated], 14 non‐bipolar co‐twins, and 32 demographically matched healthy comparison twins. We used three‐dimensional radial distance mapping techniques to visualize hippocampal shape differences between groups. Results: Lithium‐treated BPI patients had significantly larger global hippocampal volume compared to both healthy controls (9%) and non‐bipolar co‐twins (12%), and trend‐level larger volumes relative to non‐lithium‐treated BPI patients (8%). In contrast, hippocampal volumes in non‐lithium‐treated BPI patients did not differ from those of non‐bipolar co‐twins and control twins. 3D surface maps revealed thicker hippocampi in lithium‐treated BPI probands compared with control twins across the entire anterior‐to‐posterior extent of the cornu ammonis (CA1 and 2) regions, and the anterior part of the subiculum. Unexpectedly, co‐twins also showed significantly thicker hippocampi compared with control twins in regions that partially overlapped those showing effects in the lithium treated BPI probands. Conclusions: These findings suggest that regionally thickened hippocampi in bipolar I disorder may be partly due to familial factors and partly due to lithium‐induced neurotrophy, neurogenesis, or neuroprotection. Unlike schizophrenia, hippocampal alterations in co‐twins of bipolar I disorder probands are likely to manifest as subtle volume excess rather than deficit, perhaps indicating protective rather than risk effects. Hum Brain Mapp, 2012. © 2011 Wiley Periodicals, Inc.
The gene expression profile of unstimulated dendritic cells can be used as a predictor of function
Authors: Liu Wai M. , Dennis Jayne L. , Fowler Daniel W. , Dalgleish Angus G.
Published: March 2011

Dendritic cells (DCs) represent a subset of professional antigen presenting cell (APC) whose role is to elicit immune responses against harmful antigens. They have been used in DC vaccines to stimulate the immune system to kill cancer cells. However, successes in clinical trials have been limited, which may be attributed to a lack of appreciation of the quality of DCs used. In the present study, whole human genome microarrays were used to examine alterations in gene expression of monocyte‐derived DCs after stimulation with supernatants derived from tumours. Our primary aim was to investigate the possibility of a gene signature for DCs that could be used to forecast responsiveness to tumour stimuli. Results showed that DCs are divided into two groups based on their ability to increase costimulatory markers and to trigger T‐cell responses. The gene profiles of the immature DCs from these two groups were distinct, with particular divergence in genes from the interleukin (IL) 8 and thrombospondin‐1 hubs. A subpanel of genes was identified, whose signature of expression was capable of predicting DC‐stimulatory capacity. Overall, these studies have highlighted a gene‐based screen that predicts DC function, which could be used to guide DC‐vaccine trials.