bluuebunny/crossref_metadata_2025 huggingface dataset:
Places of Everyday Cosmopolitanisms: East European Construction Workers in London
Authors: Datta Ayona
Published: November 2008

I illustrate how cosmopolitanisms among East European construction workers in London are shaped by the localised spatial contexts in which encounters with difference take place. Their cosmopolitan attitudes and behaviours arise from both survival strategies and a taste for cultural goods, thus challenging the elite–working-class divide in current cosmopolitanism literature. Through semistructured interviews and participant photographs of twenty-four East European construction workers who have arrived in London since the European Union expansion in May 2004, I illustrate how these ‘new’ European citizens develop varying degrees and multitudes of cosmopolitanisms in everyday places such as building sites and shared houses. These cosmopolitanisms are shaped by their transnational histories, nationalistic sentiments, and access to social and cultural capital in specific localised contexts. Thus subjective perceptions of gendered, ethnic, and racial notions of ‘others’ that are carried across national boundaries are reinforced or challenged as their encounters with ‘others’ produce perceptions of marginalisation or empowerment in these places. Finally, I suggest that cosmopolitanism should be understood not simply through class but rather also through access to power and capital in everyday localised contexts.
Endogenous polyamines regulate cortical neuronal excitability by blocking voltage-gated Na+channels
Authors: Fleidervish Ilya A. , Libman Lior , Katz Efrat , Gutnick Michael J.
Published: November 2008

Because the excitable properties of neurons in the neocortex depend on the characteristics of voltage-gated Na+channels, factors which regulate those characteristics can fundamentally modify the dynamics of cortical circuits. Here, we report on a novel neuromodulatory mechanism that links the availability of Na+channels to metabolism of polyamines (PAs) in the cerebral cortex. Using single channel and whole-cell recordings, we found that products of PA metabolism, the ubiquitous aliphatic polycations spermine and spermidine, are endogenous blockers of Na+channels in layer 5 pyramidal cells. Because the blockade is activity-dependent, it is particularly effective against Na+channels which fail to inactivate rapidly and thus underlie the persistent Na+current. At the level of the local cortical circuit, pharmacological depletion of PAs led to increased spontaneous spiking and periods of hypersynchronous discharge. Our data suggest that changes in PA levels, whether associated with normal brain states or pathological conditions, profoundly modify Na+channel availability and thereby shape the integrative behavior of single neurons and neocortical circuits.
Memory traces in dynamical systems
Authors: Ganguli Surya , Huh Dongsung , Sompolinsky Haim
Published: November 2008

To perform nontrivial, real-time computations on a sensory input stream, biological systems must retain a short-term memory trace of their recent inputs. It has been proposed that generic high-dimensional dynamical systems could retain a memory trace for past inputs in their current state. This raises important questions about the fundamental limits of such memory traces and the properties required of dynamical systems to achieve these limits. We address these issues by applying Fisher information theory to dynamical systems driven by time-dependent signals corrupted by noise. We introduce the Fisher Memory Curve (FMC) as a measure of the signal-to-noise ratio (SNR) embedded in the dynamical state relative to the input SNR. The integrated FMC indicates the total memory capacity. We apply this theory to linear neuronal networks and show that the capacity of networks with normal connectivity matrices is exactly 1 and that of any network of N neurons is, at most, N. A nonnormal network achieving this bound is subject to stringent design constraints: It must have a hidden feedforward architecture that superlinearly amplifies its input for a time of order N, and the input connectivity must optimally match this architecture. The memory capacity of networks subject to saturating nonlinearities is further limited, and cannot exceed

N

. This limit can be realized by feedforward structures with divergent fan out that distributes the signal across neurons, thereby avoiding saturation. We illustrate the generality of the theory by showing that memory in fluid systems can be sustained by transient nonnormal amplification due to convective instability or the onset of turbulence.
Wnt signaling promotes AChR aggregation at the neuromuscular synapse in collaboration with agrin
Authors: Henriquez Juan P. , Webb Anna , Bence Matthew , Bildsoe Heidi , Sahores Macarena , Hughes Simon M. , Salinas Patricia C.
Published: November 2008

Wnt proteins regulate the formation of central synapses by stimulating synaptic assembly, but their role at the vertebrate neuromuscular junction (NMJ) is unclear. Wnt3 is expressed by lateral motoneurons of the spinal cord during the period of motoneuron-muscle innervation. Using gain- and loss-of-function studies in the chick wing, we demonstrate that Wnt signaling is necessary for the formation of acetylcholine receptor (AChR) clusters without affecting muscle growth. Similarly, diaphragms from
Dishevelled-1
mutant mice with deficiency in Wnt signaling exhibit defects in cluster distribution. In cultured myotubes, Wnt3 increases the number and size of AChR clusters induced by agrin, a nerve-derived signal critical for NMJ development. Wnt3 does not signal through the canonical Wnt pathway to induce cluster formation. Instead, Wnt3 induces the rapid formation of unstable AChR micro-clusters through activation of Rac1, which aggregate into large clusters only in the presence of agrin. Our data reveal a role for Wnts in post-synaptic assembly at the vertebrate NMJ by enhancing agrin function through Rac1 activation.
The nature of the lymphopenic environment dictates protective function of homeostatic-memory CD8
+
T cells
Authors: Hamilton Sara E. , Jameson Stephen C.
Published: November 2008

A functional memory T cell pool is critical for resistance to pathogen reinfection. Lymphopenia produces memory-like CD8
+
T cells through homeostatic proliferation, and such “HP-memory” cells can control lethal bacterial infections similarly to conventional, antigen-experienced, memory T cells. These 2 pathways for memory T cell generation are quite distinct. We show here, however, that similar factors are required for production of protective memory CD8 T cells via both homeostatic and conventional pathways. Induction of protective HP-memory CD8 T cells requires CD4
+
T cell “help,” which we show is antigen nonspecific yet requires CD40L–CD40 interactions with host cells. The functional competence of HP-memory CD8 T cells also requires release of endogenous bacterial components (which follows irradiation-induced lymphopenia), potentially mimicking the role of adjuvants in conventional immune responses. Lymphopenic environments lacking these key factors support similar CD8 T cell homeostatic proliferation and the acquisition of memory phenotype, yet the HP-memory cells generated are defective in pathogen elimination. These findings suggest unexpected parallels in the requirements for generating protective memory CD8 T cells by distinct pathways, and they suggest ways to bolster immune competence during recovery from lymphopenia.
Transmitter-receptor mismatch in GABAergic synapses in the absence of activity
Authors: Cesa Roberta , Morando Laura , Strata Piergiorgio
Published: November 2008

Competition among different axons to reach the somatodendritic region of the target neuron is an important event during development to achieve the final architecture typical of the mature brain. Trasmitter-receptor matching is a critical step for the signaling between neurons. In the cerebellar cortex, there is a persistent competition between the two glutamatergic inputs, the parallel fibers and the climbing fibers, for the innervation of the Purkinje cells. The activity of the latter input is necessary to maintain its own synaptic contacts on the proximal dendritic domain and to confine the parallel fibers in the distal one. Here, we show that climbing fiber activity also limits the distribution of the GABAergic input in the proximal domain. In addition, blocking the activity by tetrodotoxin infusion in Wistar rat cerebellum, a synapse made by GABAergic terminals onto the recently formed Purkinje cell spines appear in the proximal dendrites. The density of GABAergic terminals is increased, and unexpected double symmetric/asymmetric postsynaptic densities add to the typical symmetric phenotype of the GABAergic shaft synapses. Moreover, glutamate receptors appear in these ectopic synapses even in the absence of glutamate transmitter inside the presynaptic terminal and close to GABA receptors. These results suggest that the Purkinje cell has an intrinsic tendency to develop postsynaptic assemblies of excitatory types, including glutamate receptors, over the entire dendritic territory. GABA receptors are induced in these assemblies when contacted by GABAergic terminals, thus leading to the formation of hybrid synapses.
CP1-dependent partitioning of pretransfer and posttransfer editing in leucyl-tRNA synthetase
Authors: Boniecki Michal T. , Vu Michael T. , Betha Aswini K. , Martinis Susan A.
Published: November 2008

Mistranslation is toxic to bacterial and mammalian cells and can lead to neurodegeneration in the mouse. Mistranslation is caused by the attachment of the wrong amino acid to a specific tRNA. Many aminoacyl-tRNA synthetases have an editing activity that deacylates the mischarged amino acid before capture by the elongation factor and transport to the ribosome. For class I tRNA synthetases, the editing activity is encoded by the CP1 domain, which is distinct from the active site for aminoacylation. What is not clear is whether the enzymes also have an editing activity that is separable from CP1. A point mutation in CP1 of class I leucyl-tRNA synthetase inactivates deacylase activity and produces misacylated tRNA. In contrast, although deletion of the entire CP1 domain also disabled the deacylase activity, the deletion-bearing enzyme produced no mischarged tRNA. Further investigation showed that a second tRNA-dependent activity prevented misacylation and is intrinsic to the active site for aminoacylation.
Interaction of brefeldin A-inhibited guanine nucleotide-exchange protein (BIG) 1 and kinesin motor protein KIF21A
Authors: Shen Xiaoyan , Meza-Carmen Victor , Puxeddu Ermanno , Wang Guanghui , Moss Joel , Vaughan Martha
Published: November 2008

Brefeldin A-inhibited guanine nucleotide-exchange protein (BIG) 1 activates human ADP-ribosylation factor (ARF) 1 and 3 by accelerating the replacement of ARF-bound GDP with GTP to initiate recruitment of coat proteins for membrane vesicle formation. Liquid chromatography MS/MS analysis of peptides from proteins that co-precipitated with BIG1 antibodies identified “kinesin family member 21A” (KIF21A), a plus-end-directed motor protein that moves cargo on microtubules away from the microtubule-organizing center. Reciprocal immunoprecipitation (IP) of endogenous proteins and microscopically apparent overlap of immunoreactive BIG1 with overexpressed GFP-KIF21A in the perinuclear region were consistent with an interaction of KIF21A–BIG1. Overexpression of full-length KIF21A and BIG1 and their fragments in HEK293 cells followed by reciprocal IP revealed that the C-terminal tail of KIF21A, with seven WD-40 repeats, may interact with structure in the C-terminal region of BIG1. Interfering with cyclic activation and inactivation of ARF1 by overexpressing constitutively active ARF1(Q71L) or dominant inactive ARF1(T31N) altered the distribution of BIG1 as well as its interaction with KIF21A. A requirement for ARF1 was confirmed by its selective depletion with siRNA. Unlike disruption of microtubules with nocodazole, selective inhibition of transport by depletion of KIF21A with specific siRNA altered BIG1 distribution without changing that of intrinsic Golgi membrane proteins. These newly recognized interactions of BIG1 and KIF21A should enable us to understand better the mechanisms through which, acting together, they may integrate local events in membrane trafficking with longer-range transport processes and to relate those processes to the diverse signaling and scaffold functions of BIG1.
Role of nitric oxide signaling components in differentiation of embryonic stem cells into myocardial cells
Authors: Mujoo Kalpana , Sharin Vladislav G. , Bryan Nathan S. , Krumenacker Joshua S. , Sloan Courtney , Parveen Shanaz , Nikonoff Lubov E. , Kots Alexander Y. , Murad Ferid
Published: November 2008

Nitric oxide (NO) is involved in number of physiological and pathological events. Our previous studies demonstrated a differential expression of NO signaling components in mouse and human ES cells. Here, we demonstrate the effect of NO donors and soluble guanylyl cyclase (sGC) activators in differentiation of ES cells into myocardial cells. Our results with mouse and human ES cells demonstrate an increase in Nkx2.5 and myosin light chain (MLC2) mRNA expression on exposure of cells to NO donors and a decrease in mRNA expression of both cardiac-specific genes with nonspecific NOS inhibitor and a concomitant increase and decrease in the mRNA levels of sGC α
1
subunit. Although sGC activators alone exhibited an increase in mRNA expression of cardiac genes (MLC2 and Nkx2.5), robust inductions of mRNA and protein expression of marker genes were observed when NO donors and sGC activators were combined. Measurement of NO metabolites revealed an increase in the nitrite levels in the conditioned media and cell lysates on exposure of cells to the different concentrations of NO donors. cGMP analysis in undifferentiated stem cells revealed a lack of stimulation with NO donors. Differentiated cells however, acquired the ability to be stimulated by NO donors. Although, 3-(4-amino-5-cyclopropylpyrimidin-2-yl)-1-(2-fluorobenzyl)-1H-pyrazolo [3,4-b]pyridine (BAY 41-2272) alone was able to stimulate cGMP accumulation, the combination of NO donors and BAY 41-2272 stimulated cGMP levels more than either of the agents separately. These studies demonstrate that cGMP-mediated NO signaling plays an important role in the differentiation of ES cells into myocardial cells.
The mini‐resectoscope: A new instrument for office hysteroscopic surgery
Authors: PAPALAMPROS PANOS , GAMBADAURO PIETRO , PAPADOPOULOS NIKOLAOS , POLYZOS DIMITRIS , CHAPMAN LYNNE , MAGOS ADAM
Published: November 2008

Background. Outpatient hysteroscopy has become well‐established for the investigation abnormal uterine bleeding. Although “See and Treat” clinics have been widely introduced, the types of procedures offered are limited, and many patients with intrauterine pathology continue to be admitted as in‐patients for hysteroscopic surgery. We wanted to investigate the feasibility and acceptability of surgery for small intrauterine lesions without the need for general anesthesia by using a miniature resectoscope. Methods. This was a prospective observational study on 30 women with abnormal uterine bleeding associated with endometrial polyps or small (<3 cm) type 0 or 1 submucous fibroids. Hysteroscopic polypectomy (n = 26) or myomectomy (n = 4) was carried out using a 16 Fr gauge mini‐resectoscope. Results. Ten procedures were carried out in the outpatient clinic and 20 in the operating theatre. Sixteen procedures were done without any anaesthesia and 14 after intra‐cervical local anesthetic injections. The polyps and fibroids ranged in size from 1 to 5 cm, and all procedures took less than 15 minutes from the time the vagina was instrumented to the end of surgery. All procedures were completed successfully and were well tolerated with little discomfort. There were no complications. Conclusions. The mini‐resectoscope appears to be an efficient and acceptable instrument for hysteroscopic surgery and can be used without general anesthesia for minor procedure such as polypectomy and the resection of small submucous fibroids.
Maternal–neonatal amino acid blood levels in relation to the mode of delivery
Authors: SCHULPIS KLEOPATRA H. , VLACHOS GEORGE D. , PAPAKONSTANTINOU EVANGELOS D. , KARIKAS GEORGE A. , VLACHOS DIMITRIOS G. , ROMA ELEFTHERIA , ANTSAKLIS ARIS , PAPASSOTIRIOU IOANNIS , TSAKIRIS STYLIANOS
Published: November 2008

Objective. To investigate the effect of the mode of delivery on maternal–neonatal amino acid levels as high blood levels of some amino acids are implicated with endurance exercise. Design. Comparative study. Sample. Thirty women in normal pregnancy divided into two groups: Group A (n = 15) with normal labor and vaginal delivery and group B (n = 15) with scheduled cesarean section. Material and methods. Blood was obtained from the mothers pre‐ versus post‐delivery as well as from the umbilical cord. Routine laboratory tests (liver enzymes, muscle enzyme, etc.) and the amino acid blood levels were measured with a clinical chemistry analyzer and tandem mass spectrometry methods, respectively. Results. Routine laboratory tests and the amino acid blood levels were similar in the two groups of mothers pre‐delivery. Total antioxidant status levels were reduced, whereas the branched‐chain amino acids (BCAAs) and alanine levels were remarkably elevated in the sera of group A post – delivery, whereas they remained unaltered in group B at the same time of study. The mentioned BCAAs and alanine levels were higher in the umbilical cord blood of group A than those in group B. The rest of the amino acids were similar. Conclusions. The increased BCAAs and alanine blood levels in mothers of group A may be related to uterine and skeletal muscle contractions during the vaginal delivery process and the high levels in the umbilical cord blood of their neonates may mirror those of the mothers. The elevation of BCAAs both in mothers of group A and their neonates may exclude or minimize tyrosine and tryptophane levels from entry in the brain resulting in decreased biogenic amine and increased prolactin production in the central nervous system of these mothers and their infants.
Are Retinal Microvascular Caliber Changes Associated with Severity of Coronary Artery Disease in Symptomatic Cardiac Patients?
Authors: KREIS ANDREAS JOSEF , NGUYEN THANH TAN , WANG JIE JIN , ROGERS SOPHIE , AL‐FIADH ALI , FREEMAN MELANIE , WONG TIEN YIN , FAROUQUE H.M. OMAR
Published: November 2008

Objectives: Recent population‐based studies have shown that retinal vascular caliber may predict the risk of clinical coronary artery disease (CAD) events. Whether this association is related to macro‐ or microvascular mechanisms remains unknown. We investigated the relationship of retinal vascular caliber with severity and extent of CAD in symptomatic cardiac patients.

Materials and Methods: Overall, 98 patients attending diagnostic coronary angiography were recruited. Coronary angiography was used to assess for the severity and extent of CAD. Digital retinal photography was performed immediately prior to cardiac catheterization, and retinal vascular caliber was measured from these photographs by using a computer program and summarized as central retinal arteriolar (CRAE) and venular (CRVE) equivalents.

Results: Retinal arteriolar and venular calibers were not associated with increasing severity of CAD, as assessed by Leaman scores (CRAE/CRVE: P for trend=0.17/0.57), presence of clinically significant CAD (CRAE/CRVE: P=0.35/0.32), or number of diseased vessels (CRAE/CRVE: P for trend=0.18/0.69).

Conclusions: Retinal vascular caliber changes are not associated with the severity of obstructive CAD in symptomatic patients. These data suggest that the association of retinal vascular caliber with clinical CAD seen in epidemiological studies may not be applicable to clinical symptomatic patients and may be related to microvascular, rather than macrovascular, mechanisms.
Them-AAA Protease Processes CytochromecPeroxidase Preferentially at the Inner Boundary Membrane of Mitochondria
Authors: Suppanz Ida E. , Wurm Christian A. , Wenzel Dirk , Jakobs Stefan
Published: November 2008

The m-AAA protease is a conserved hetero-oligomeric complex in the inner membrane of mitochondria. Recent evidence suggests a compartmentalization of the contiguous mitochondrial inner membrane into an inner boundary membrane (IBM) and a cristae membrane (CM). However, little is known about the functional differences of these subdomains. We have analyzed the localizations of the m-AAA protease and its substrate cytochrome c peroxidase (Ccp1) within yeast mitochondria using live cell fluorescence microscopy and quantitative immunoelectron microscopy. We find that the m-AAA protease is preferentially localized in the IBM. Likewise, the membrane-anchored precursor form of Ccp1 accumulates in the IBM of mitochondria lacking a functional m-AAA protease. Only upon proteolytic cleavage the mature form mCcp1 moves into the cristae space. These findings suggest that protein quality control and proteolytic activation exerted by the m-AAA protease take place preferentially in the IBM pointing to significant functional differences between the IBM and the CM.
Dynein-2 Affects the Regulation of Ciliary Length but Is Not Required for Ciliogenesis inTetrahymena thermophila
Authors: Rajagopalan Vidyalakshmi , Subramanian Aswati , Wilkes David E. , Pennock David G. , Asai David J.
Published: November 2008

Eukaryotic cilia and flagella are assembled and maintained by the bidirectional intraflagellar transport (IFT). Studies in alga, nematode, and mouse have shown that the heavy chain (Dyh2) and the light intermediate chain (D2LIC) of the cytoplasmic dynein-2 complex are essential for retrograde intraflagellar transport. In these organisms, disruption of either dynein-2 component results in short cilia/flagella with bulbous tips in which excess IFT particles have accumulated. In Tetrahymena, the expression of the DYH2 and D2LIC genes increases during reciliation, consistent with their roles in IFT. However, the targeted elimination of either DYH2 or D2LIC gene resulted in only a mild phenotype. Both knockout cell lines assembled motile cilia, but the cilia were of more variable lengths and less numerous than wild-type controls. Electron microscopy revealed normally shaped cilia with no swelling and no obvious accumulations of material in the distal ciliary tip. These results demonstrate that dynein-2 contributes to the regulation of ciliary length but is not required for ciliogenesis in Tetrahymena.
Sterols Are Mainly in the Cytoplasmic Leaflet of the Plasma Membrane and the Endocytic Recycling Compartment in CHO Cells
Authors: Mondal Mousumi , Mesmin Bruno , Mukherjee Sushmita , Maxfield Frederick R.
Published: November 2008

The transbilayer distribution of many lipids in the plasma membrane and in endocytic compartments is asymmetric, and this has important consequences for signaling and membrane physical properties. The transbilayer distribution of cholesterol in these membranes is not properly established. Using the fluorescent sterols, dehydroergosterol and cholestatrienol, and a variety of fluorescence quenchers, we studied the transbilayer distribution of sterols in the plasma membrane (PM) and the endocytic recycling compartment (ERC) of a CHO cell line. A membrane impermeant quencher, 2,4,6-trinitrobenzene sulfonic acid, or lipid-based quenchers that are restricted to the exofacial leaflet of the plasma membrane only reduce the fluorescence intensity of these sterols in the plasma membrane by 15–32%. When the same quenchers have access to both leaflets, they quench 70–80% of the sterol fluorescence. Sterol fluorescence in the ERC is also quenched efficiently in the permeabilized cells. In microinjection experiments, delivery of quenchers into the cytosol efficiently quenched the fluorescent sterols associated with the PM and with the ERC. Quantitative analysis indicates that 60–70% of the PM sterol is in the cytoplasmic leaflet. This means that cholesterol constitutes ∼40 mol% of cytoplasmic leaflet lipids, which may have important implications for intracellular cholesterol transport and membrane domain formation.
A practical method for exact computation of subtree prune and regraft distance
Authors: Wu Yufeng
Published: November 2008

Motivation: Subtree prune and regraft (SPR) is one kind of tree rearrangements that has seen applications in solving several computational biology problems. The minimum number of rooted SPR (rSPR) operations needed to transform one rooted binary tree to another is called the rSPR distance between the two trees. Computing the rSPR distance has been actively studied in recent years. Currently, there is a lack of practical software tools for computing the rSPR distance for relatively large trees with large rSPR distance.

Results: In this article, we present a simple and practical method that computes the exact rSPR distance with integer linear programming. By applying this new method on several simulated and real biological datasets, we show that our new method outperforms existing software tools in term of accuracy and ef.ciency. Our experimental results indicate that our method can compute the exact rSPR distance for many large trees with large rSPR distance.

Availability: A software tool, SPRDist, is available for download from the web page: http://www.engr.uconn.edu/~ywu.

Contact:  ywu@engr.uconn.edu
Rheological and Pasting Properties of Buckwheat (Fagopyrum esculentum Möench) Flours With and Without Jet‐Cooking
Authors: Inglett George E. , Xu Jingyuan , Stevenson David G. , Chen Diejun
Published: November 2008

Pasting, rheological, and water‐holding properties of buckwheat (Fagopyrum esculentum) flour obtained from whole achenes separated into three particle sizes, and three commercial flours (Fancy, Supreme, and Farinetta) were measured with or without jet‐cooking. Fancy had instantaneous paste viscosity (measured using RVA) after jet‐cooking that was not observed for Supreme or Farinetta, and paste viscosity was lower for the latter two flours. Supreme jet‐cooked flour exhibited higher peak viscosity than flour without jet‐cooking, and paste exhibited high shear‐thinning. Fancy exhibited strongest viscoelastic properties (measured using a rheometer). Jet‐cooking damaged buckwheat flour structure, thereby reducing viscoelasticity. Buckwheat flour pastes experienced shear‐thinning over a wide range of shear rates. Jet‐cooking greatly enhanced water‐holding capacity. Buckwheat flour particle size did not greatly influence paste viscosity. Study showed buckwheat flours have unique pasting and rheological characteristics that have different food applications, which could especially be useful for people with celiac disease as buckwheat is gluten‐free.
Nixtamalized Instant Flour from Corn (Zea mays L.) Meal: Optimization of Nixtamalization Conditions
Authors: Cuevas‐Rodríguez E. O. , Reyes‐Moreno C. , Eckhoff S. R. , Milán‐Carrillo J.
Published: November 2008

The present investigation provides a new method for the nixtamalization process wherein corn endosperm fractions (corn meal) are treated in an alkaline solution that yields quality masa or instant masa flour like traditional nixtamalization process (alkaline cooking of corn with lime). The objective of this work was to determine the best combination of nixtamalization process variables for producing nixtamalized instant flour (NIF) from corn meal. Nixtamalization conditions were selected from factorial combinations of process variables including nixtamalization time (NT 8–22 min) and cooking temperature (CT 78–88°C). A central composite rotable experimental design was chosen. Lime concentration was 1% (10 g of Ca(OH)2/L of water) and ratio of corn meal to cooking medium was 1:4. At the end of each cooking, each treatment was steeped for 5 hr at room temperature (25°C). Nixtamalized corn meal was dried (55°C/12 hr) and milled to pass through 80 U.S. mesh to obtain NIF. Response surface methodology (RSM) was applied as an optimization technique over four response variables: masa firmness (MF), masa adhesiveness (MA), tortilla cutting force (CF), and tortilla tensile strength (TS). Predictive models for response variables were developed as a function of process variables. Conventional graphic methods were applied to obtain response variable values similar to the control (MASECA). Contour plots of each response variable applied superposition surface methodology to obtain a contour plot for observation and for selecting the best combination of nixtamalization time (NT 15 min) and cooking temperature (CT 83°C) for producing an optimized NIF from corn meal. Values of MF, MA, CF, and TS obtained from the predictive models were compared with those derived from experimental tests; a close agreement (coefficient of variance < 10%) between both values was observed.
An infanticide attempt by a free-roaming feral stallion (
Equus caballus
)
Authors: Gray Meeghan E
Published: November 2008

Infanticide by adult males occurs in a variety of species. While infanticidal attacks have been documented in several equid species in captivity, it has never been witnessed in free-roaming feral horses. I report an infanticide attempt by a free-living feral stallion on a recently born female foal. The stallion picked up the foal by the shoulders, tossed it around twice and bit in on the neck several times. The dam of the foal charged the stallion and successfully protected her foal from additional attacks. The foal survived the attack and later weaned successfully. The stallion recently took over the band and was excluded as the sire through genetic analysis. While this type of attack is rare, this case lends support to the sexual selection hypothesis and further demonstrates that equids have evolved with the risk of infanticide. Furthermore, it shows that maternal protectiveness can be successful against attacks by infanticidal males.
Boundary-induced electrophoresis of uncharged conducting particles: remote wall approximations
Authors: Yariv Ehud
Published: November 2008

An initially uncharged ideally polarizable particle is freely suspended in an electrolyte solution in the vicinity of an uncharged dielectric wall. A uniform electric field is externally applied parallel to the wall, inflicting particle drift perpendicular to it. Assuming a thin Debye thickness, the electrokinetic flow is analysed for large particle–wall separations using reflection methods, thereby yielding an asymptotic approximation for the particle velocity. The leading-order correction term in that approximations stems from wall polarization.
Reticulated tubes: effective elastic properties and actuation response
Authors: Mai S.P , Fleck N.A
Published: November 2008

The structural performance is explored for a reticulated circular tube made from a periodic lattice: triangulated; hexagonal; Kagome; and square lattices. The finite-element (FE) method is used to determine the macroscopic bending, torsional and axial rigidities of each tube. Additional insight is obtained by examining the structural mechanics of the pin-jointed version of each topology. For all pin-jointed lattices considered, no states of self-stress exist. However, collapse mechanisms do exist for all reticulated tubes, and for the Kagome and hexagonal lattices some of these mechanisms produce macroscopic generalized strain. These strain-producing collapse modes are additional to those observed in the planar version of these lattices. Consequently, the structural rigidities of tubes with walls made from the rigid-jointed Kagome lattice or hexagonal lattice are less than those predicted from the in-plane effective properties of these two lattices. The morphing capacity of reticulated tubes is also explored by replacing a single bar with an actuator in the FE simulations. The actuation stiffness of the structure is defined by the stiffness of the reticulated tube in resisting extension by the actuated bar. The actuation stiffness is explored as a function of the type of lattice, number of unit cells around the circumference, orientation of the actuated bar and of the bar stockiness. In all cases, the macroscopic shape change of the tube can be idealized as a combination of a local rotation, axial extension, axial twist and shear displacement of the cross-section.
A new stem turtle from the Middle Jurassic of Scotland: new insights into the evolution and palaeoecology of basal turtles
Authors: Anquetin Jérémy , Barrett Paul M , Jones Marc E.H , Moore-Fay Scott , Evans Susan E
Published: November 2008

The discovery of a new stem turtle from the Middle Jurassic (Bathonian) deposits of the Isle of Skye, Scotland, sheds new light on the early evolutionary history of Testudinata.
Eileanchelys waldmani
gen. et sp. nov. is known from cranial and postcranial material of several individuals and represents the most complete Middle Jurassic turtle described to date, bridging the morphological gap between basal turtles from the Late Triassic–Early Jurassic and crown-group turtles that diversify during the Late Jurassic. A phylogenetic analysis places the new taxon within the stem group of Testudines (crown-group turtles) and suggests a sister-group relationship between
E. waldmani
and
Heckerochelys romani
from the Middle Jurassic of Russia. Moreover,
E. waldmani
also demonstrates that stem turtles were ecologically diverse, as it may represent the earliest known aquatic turtle.
Range-wide mtDNA phylogeography yields insights into the origins of Asian elephants
Authors: Vidya T.N.C , Sukumar Raman , Melnick Don J
Published: November 2008

Recent phylogeographic studies of the endangered Asian elephant (Elephas maximus) reveal two highly divergent mitochondrial DNA (mtDNA) lineages, an elucidation of which is central to understanding the species's evolution. Previous explanations for the divergent clades include introgression of mtDNA haplotypes between ancestral species, allopatric divergence of the clades between Sri Lanka or the Sunda region and the mainland, historical trade of elephants, and retention of divergent lineages due to large population sizes. However, these studies lacked data from India and Myanmar, which host approximately 70 per cent of all extant Asian elephants. In this paper, we analyse mtDNA sequence data from 534 Asian elephants across the species's range to explain the current distribution of the two divergent clades. Based on phylogenetic reconstructions, estimates of times of origin of clades, probable ancestral areas of origin inferred from dispersal–vicariance analyses and the available fossil record, we believe both clades originated fromElephas hysudricus. This probably occurred allopatrically in different glacial refugia, the α clade in the Myanmar region and the β clade possibly in southern India–Sri Lanka, 1.6–2.1 Myr ago. Results from nested clade and dispersal–vicariance analyses indicate a subsequent isolation and independent diversification of the β clade in both Sri Lanka and the Sunda region, followed by northward expansion of the clade. We also find more recent population expansions in both clades based on mismatch distributions. We therefore suggest a contraction–expansion scenario during severe climatic oscillations of the Quaternary, with range expansions from different refugia during warmer interglacials leading to the varying geographical overlaps of the two mtDNA clades. We also demonstrate that trade in Asian elephants has not substantially altered the species's mtDNA population genetic structure.
The dynamics of Titan's troposphere
Authors: Tokano Tetsuya
Published: November 2008

While the Voyager mission could essentially not reveal the dynamics of Titan's troposphere, useful information was obtained by the Cassini spacecraft and, particularly, by the Huygens probe that landed on Titan's surface; this information can be interpreted by means of numerical models of atmospheric circulation. The meridional circulation is likely to consist of a large Hadley circulation asymmetric about the equator, but is susceptible to disruption by turbulence in clouds. The zonal wind in the troposphere is comparable to or even weaker than that in the terrestrial troposphere and contains zones of easterlies, much in contrast to the super-rotating stratosphere. Unique to Titan is the transition from a geostrophic to cyclostrophic wind balance in the upper troposphere. While Earth-like storm systems associated with baroclinic instability are absent, Saturn's gravitational tide introduces a planetary wave of wavenumber 2 and a periodical variation in the wind direction in the troposphere. Unlike on Earth, the wind over the equatorial surface is westerly. The seasonal reversal in the Hadley circulation sense and zonal wind direction is predicted to have a substantial influence on the formation of dunes as well as variation of Titan's rotation rate and length of day.
Dynamical implications of seasonal and spatial variations in Titan's stratospheric composition
Authors: Teanby Nicholas A , Irwin Patrick G.J , de Kok Remco , Nixon Conor A
Published: November 2008

Titan's diverse inventory of photochemically produced gases can be used as tracers to probe atmospheric circulation. Since the arrival of the Cassini–Huygens mission in July 2004 it has been possible to map the seasonal and spatial variations of these compounds in great detail. Here, we use 3.5 years of data measured by the Cassini Composite InfraRed Spectrometer instrument to determine spatial and seasonal composition trends, thus providing clues to underlying atmospheric motions. Titan's North Pole (currently in winter) displays enrichment of trace species, implying subsidence is occurring there. This is consistent with the descending branch of a single south-to-north stratospheric circulation cell and a polar vortex. Lack of enrichment in the south over most of the observed time period argues against the presence of any secondary circulation cell in the Southern Polar stratosphere. However, a residual cap of enriched gas was observed over the South Pole early in the mission, which has since completely dissipated. This cap was most probably due to residual build-up from southern winter. These observations provide new and important constraints for models of atmospheric photochemistry and circulation.
Composition and chemistry of Titan's thermosphere and ionosphere
Authors: Vuitton V , Yelle R.V , Lavvas P
Published: November 2008

Titan has long been known to harbour the richest atmospheric chemistry in the Solar System. Until recently, it had been believed that complex hydrocarbons and nitriles were produced through neutral chemistry that would eventually lead to the formation of micrometre sized organic aerosols. However, recent measurements by the Cassini spacecraft are drastically changing our understanding of Titan's chemistry. The Ion and Neutral Mass Spectrometer (INMS) and the Cassini Plasma Spectrometer (CAPS) revealed an extraordinary complex ionospheric composition. INMS detected roughly 50 positive ions with
m
/
z
<100 and a density higher than 0.1 cm
−3
. CAPS provided evidence for heavy (up to 350 amu) positively and negatively charged (up to 4000 amu) ions. These observations all indicate that Titan's ionospheric chemistry is incredibly complex and that molecular growth starts in the upper atmosphere rather than at lower altitude. Here, we review the recent progress made on ionospheric chemistry. The presence of heavy neutrals in the upper atmosphere has been inferred as a direct consequence of the presence of complex positive ions. Benzene (C
6
H
6
) is created by ion chemistry at high altitudes and its main photolysis product, the phenyl radical (C
6
H
5
), is at the origin of the formation of aromatic species at lower altitude.
Insulin‐like growth factor stimulation increases radiosensitivity of a pancreatic cancer cell line through endoplasmic reticulum stress under hypoxic conditions
Authors: Isohashi Fumiaki , Endo Hiroko , Mukai Mutsuko , Inoue Takehiro , Inoue Masahiro
Published: November 2008

Tumor hypoxia is an obstacle to radiotherapy. Radiosensitivity under hypoxic conditions is determined by molecular oxygen levels, as well as by various biological cellular responses. The insulin‐like growth factor (IGF) signaling pathway is a widely recognized survival signal that confers radioresistance. However, under hypoxic conditions the role of IGF signaling in radiosensitivity is still poorly understood. Here, we demonstrate that IGF‐II stimulation decreases clonogenic survival under hypoxic conditions in the pancreatic cancer cell lines AsPC‐1 and Panc‐1, and in the human breast cancer cell line MCF‐7. IGF treatment under hypoxic conditions suppressed increased radiation sensitivity in these cell lines by pharmacologically inhibiting the phosphoinositide 3‐kinase–mammalian target of rapamycin pathway, a major IGF signal‐transduction pathway. Meanwhile, IGF‐II induced the endoplasmic reticulum stress response under hypoxia, including increased protein levels of CHOP and ATF4, mRNA levels of CHOP, GADD34, and BiP, as well as splicing levels of XBP‐1. The response was suppressed by inhibiting phosphoinositide 3‐kinase and mammalian target of rapamycin activity. Overexpression of CHOP in AsPC‐1 cells increased radiation sensitivity by IGF‐II simulation under hypoxic conditions, whereas suppression of CHOP expression levels with small hairpin RNA or a dominant negative form of a proline‐rich extensin‐like receptor protein kinase in hypoxia decreased IGF‐induced radiosensitivity. IGF‐induced endoplasmic reticulum stress contributed to radiosensitization independent of cell cycle status. Taken together, IGF stimulation increased radiosensitivity through the endoplasmic reticulum stress response under hypoxic conditions. (Cancer Sci 2008; 99: 2395–2401)
Non‐solid oncogenes in solid tumors: EML4–ALK fusion genes in lung cancer
Authors: Mano Hiroyuki
Published: November 2008

It is generally accepted that recurrent chromosome translocations play a major role in the molecular pathogenesis of hematological malignancies but not of solid tumors. However, chromosome translocations involving the e26 transformation‐specific sequence transcription factor loci have been demonstrated recently in many prostate cancer cases. Furthermore, through a functional screening with retroviral cDNA expression libraries, we have discovered the fusion‐type protein tyrosine kinase echinoderm microtubule‐associated protein like‐4 (EML4)–anaplastic lymphoma kinase (ALK) in non‐small cell lung cancer (NSCLC) specimens. A recurrent chromosome translocation, inv(2)(p21p23), in NSCLC generates fused mRNA encoding the amino‐terminal half of EML4 ligated to the intracellular region of the receptor‐type protein tyrosine kinase ALK. EML4–ALK oligomerizes constitutively in cells through the coiled coil domain within the EML4 region, and becomes activated to exert a marked oncogenicity both in vitro and in vivo. Break and fusion points within the EML4 locus may diverge in NSCLC cells to generate various isoforms of EML4–ALK, which may constitute ~5% of NSCLC cases, at least in the Asian ethnic group. In the present review I summarize how detection of EML4–ALK cDNA may become a sensitive diagnostic means for NSCLC cases that are positive for the fusion gene, and discuss whether suppression of ALK enzymatic activity could be an effective treatment strategy against this intractable disorder. (Cancer Sci 2008; 99: 2349–2355)
Inhibition of tumor‐induced edema by antisense VEGF is mediated by suppressive vesiculo‐vacuolar organelles (VVO) formation
Authors: Lin Zhi Xiong , Yang Li Juan , Huang Qian , Lin Jian Hua , Ren Jie , Chen Zhen Bin , Zhou Lin Ying , Zhang Peng Fei , Fu Jin
Published: November 2008

Vascular endothelial growth factor (VEGF) is an important regulator of angiogenesis, vasculogenesis and vascular permeability. Edema in glioma tumors is considered one of the most pathological characteristics, but the mechanism of regulating vascular permeability is still unclear. In the present study, tumorigenic mice were generated by subcutaneous injection of glioma cell lines, C6‐null cells and stable transfected‐C6 cells overexpressing mock vector (C6‐mock) and antisense VEGF (C6‐VEGF−/–). Overexpression of antisense VEGF (C6‐VEGF−/– mice) significantly suppressed tumor growth, decreased angiogenesis and reduced tumoral edema. Further studies by electron microscope revealed that tumor‐induced hyperpermeability was mediated by formation of vesiculo‐vacuolar organelles (VVO), specifically reducing the number of vesicle and caveolae in VVO, and this effect was blocked, at least partially, by antisense VEGF. These data show a possible mechanism of tumor‐induced hyperpermeability and indicate that blockage of VEGF might contribute to therapeutical strategies for tumor edema. (Cancer Sci 2008; 99: 2540–2546)
REG I enhances chemo‐ and radiosensitivity in squamous cell esophageal cancer cells
Authors: Hayashi Kaori , Motoyama Satoru , Koyota Souichi , Koizumi Yukio , Wang Jingshu , Takasawa Shin , Itaya‐Hironaka Asako , Sakuramoto‐Tsuchida Sumiyo , Maruyama Kiyotomi , Saito Hajime , Minamiya Yoshihiro , Ogawa Jun‐ichi , Sugiyama Toshihiro
Published: November 2008

Identification of reliable markers of chemo‐ and radiosensitivity and the key molecules that enhance the susceptibility of squamous esophageal cancer cells to anticancer treatments would be highly desirable. To test whether regenerating gene (REG) I expression enhances chemo‐ and radiosensitivity in esophageal squamous cell carcinoma cells, we used MTT (3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide) assays to compare the chemo‐ and radiosensitivities of untransfected TE‐5 and TE‐9 cells with those of cells stably transfected with REG Iα and Iβ. We then used flow cytometry to determine whether REG I expression alters cell cycle progression. No REG I mRNA or protein were detected in untransfected TE‐5 and TE‐9 cells. Transfection with REG Iα and Iβ led to strong expression of both REG I mRNA and protein in TE‐5 and TE‐9 cells, which in turn led to significant increases in both chemo‐ and radiosensitivity. Cell cycle progression was unaffected by REG I expression. REG I thus appears to enhance the chemo‐ and radiosensitivity of squamous esophageal cancer cells, which suggests that it may be a useful target for improved and more individualized treatments for patients with esophageal squamous cell carcinoma. (Cancer Sci 2008; 99: 2491–2495)