bluuebunny/crossref_metadata_2025 huggingface dataset:
Ablation of the Galnt3 Gene Leads to Low-Circulating Intact Fibroblast Growth Factor 23 (Fgf23) Concentrations and Hyperphosphatemia Despite Increased Fgf23 Expression
Authors: Ichikawa Shoji , Sorenson Andrea H. , Austin Anthony M. , Mackenzie Donald S. , Fritz Timothy A. , Moh Akira , Hui Siu L. , Econs Michael J.
Published: February 2009

Familial tumoral calcinosis is characterized by ectopic calcifications and hyperphosphatemia. The disease is caused by inactivating mutations in fibroblast growth factor 23 (FGF23), Klotho (KL), and uridine diphosphate-N-acetyl-α-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3). In vitro studies indicate that GALNT3 O-glycosylates a phosphaturic hormone, FGF23, and prevents its proteolytic processing, thereby allowing secretion of intact FGF23. In this study we generated mice lacking the Galnt3 gene, which developed hyperphosphatemia without apparent calcifications. In response to hyperphosphatemia, Galnt3-deficient mice had markedly increased Fgf23 expression in bone. However, compared with wild-type and heterozygous littermates, homozygous mice had only about half of circulating intact Fgf23 levels and higher levels of C-terminal Fgf23 fragments in bone. Galnt3-deficient mice also exhibited an inappropriately normal 1,25-dihydroxyvitamin D level and decreased alkaline phosphatase activity. Furthermore, renal expression of sodium-phosphate cotransporters and Kl were elevated in Galnt3-deficient mice. Interestingly, there were sex-specific phenotypes; only Galnt3-deficient males showed growth retardation, infertility, and significantly increased bone mineral density. In summary, ablation of Galnt3 impaired secretion of intact Fgf23, leading to decreased circulating Fgf23 and hyperphosphatemia, despite increased Fgf23 expression. Our findings indicate that Galnt3-deficient mice have a biochemical phenotype of tumoral calcinosis and provide in vivo evidence that Galnt3 plays an essential role in proper secretion of Fgf23 in mice.
Filamin A Modulates Kinase Activation and Intracellular Trafficking of Epidermal Growth Factor Receptors in Human Melanoma Cells
Authors: Fiori Jennifer L. , Zhu Tie-Nian , O'Connell Michael P. , Hoek Keith S. , Indig Fred E. , Frank Brittany P. , Morris Christa , Kole Sutapa , Hasskamp Joanne , Elias George , Weeraratna Ashani T. , Bernier Michel
Published: February 2009

The actin-binding protein filamin A (FLNa) affects the intracellular trafficking of various classes of receptors and has a potential role in oncogenesis. However, it is unclear whether FLNa regulates the signaling capacity and/or down-regulation of the activated epidermal growth factor receptor (EGFR). Here it is shown that partial knockdown of FLNa gene expression blocked ligand-induced EGFR responses in metastatic human melanomas. To gain greater insights into the role of FLNa in EGFR activation and intracellular sorting, we used M2 melanoma cells that lack endogenous FLNa and a subclone in which human FLNa cDNA has been stably reintroduced (M2A7 cells). Both tyrosine phosphorylation and ubiquitination of EGFR were significantly lower in epidermal growth factor (EGF)-stimulated M2 cells when compared with M2A7 cells. Moreover, the lack of FLNa interfered with EGFR interaction with the ubiquitin ligase c-Cbl. M2 cells exhibited marked resistance to EGF-induced receptor degradation, which was very active in M2A7 cells. Despite comparable rates of EGF-mediated receptor endocytosis, internalized EGFR colocalized with the lysosomal marker lysosome-associated membrane protein-1 in M2A7 cells but not M2 cells, in which EGFR was found to be sequestered in large vesicles and subsequently accumulated in punctated perinuclear structures after EGF stimulation. These results suggest the requirement of FLNa for efficient EGFR kinase activation and the sorting of endocytosed receptors into the degradation pathway.
Relaxin Reverses Airway Remodeling and Airway Dysfunction in Allergic Airways Disease
Authors: Royce Simon G. , Miao Yu R. , Lee Melissa , Samuel Chrishan S. , Tregear Geoffrey W. , Tang Mimi L. K.
Published: February 2009

Mice deficient in the antifibrotic hormone relaxin develop structural changes in the airway that resemble airway remodeling, and demonstrate exaggerated remodeling changes in models of allergic airways disease (AAD). Relaxin expression in asthma has not been previously studied. We evaluated the efficacy of relaxin in the treatment of established airway remodeling in a mouse model of AAD. Relaxin expression in mouse AAD was also examined by immunohistochemistry and real-time PCR. BALB/c mice with established AAD were treated with relaxin or vehicle control (sc for 14 d), and effects on airway remodeling, airway inflammation, and airway hyperresponsiveness (AHR) were assessed. Relaxin expression was significantly reduced in the airways of mice with AAD compared with controls. Recombinant relaxin treatment in a mouse model of AAD reversed collagen deposition and epithelial thickening, and significantly improved AHR (all P < 0.05 vs. vehicle control), but did not influence airway inflammation or goblet cell hyperplasia. Relaxin treatment was associated with increased matrix metalloproteinase-2 levels, suggesting a possible mechanism for its antifibrotic effects. Endogenous relaxin expression is decreased in murine AAD, whereas exogenous relaxin represents a novel treatment capable of reversing established airway remodeling and AHR.
Interleukin-11 and Leukemia Inhibitory Factor Regulate the Adhesion of Endometrial Epithelial Cells: Implications in Fertility Regulation
Authors: Marwood M. , Visser K. , Salamonsen L. A. , Dimitriadis E.
Published: February 2009

Embryo implantation requires the closely harmonized processes of apposition, attachment, and adhesion of the conceptus to the maternal endometrial epithelium. IL-11 and leukemia inhibitory factor (LIF), two IL-6 family cytokines, are produced by the endometrium and are absolutely required for implantation in mice. We examined the effect of IL-11 and LIF on human endometrial epithelial cell adhesion. Both cytokines increased adhesion of primary human endometrial epithelial cells to fibronectin and collagen IV. IL-11 stimulated, whereas LIF had no effect on the adhesion of trophoblast to endometrial epithelial cells. Focused oligogene arrays were used to identify extracellular matrix and adhesion molecules mRNAs regulated by endometrial epithelial cells. We demonstrated by real-time RT-PCR and antibody arrays that both cytokines increased integrin-α2 mRNA and protein by endometrial epithelial cells. Signal transducers and activators of transcription (STAT)-3 inhibition reduced IL-11- and LIF-mediated epithelial cell adhesion to fibronectin, suggesting both cytokines regulated adhesion via phosphorylation of STAT3. Addition of either IL-11 neutralizing antibody and IL-11 or LIF and LIF antagonist to endometrial epithelial cells abolished cytokine induced phosphorylated STAT3. LIF but not IL-11 induced adhesion to collagen IV was reduced by an integrin-α2β1 neutralizing antibody. This study demonstrated that IL-11 and LIF regulated endometrial epithelial cell adhesion, suggesting that targeting IL-11 and LIF may be useful in regulating fertility by either enhancing or blocking implantation.
Altered Iron Metabolism Is Part of the Choroid Plexus Response to Peripheral Inflammation
Authors: Marques F. , Falcao A. M. , Sousa J. C. , Coppola G. , Geschwind D. , Sousa N. , Correia-Neves M. , Palha J. A.
Published: February 2009

Iron is essential for normal cellular homeostasis but in excess promotes free radical formation and is detrimental. Therefore, iron metabolism is tightly regulated. Here, we show that mechanisms regulating systemic iron metabolism may also control iron release into the brain at the blood-choroid plexus-cerebrospinal fluid (CSF) barrier. Intraperitoneal administration of lipopolysaccharide (LPS) in mice triggers a transient transcription of the gene encoding for hepcidin, a key regulator of iron homeostasis, in the choroid plexus, which correlated with increased detection of pro-hepcidin in the CSF. Similarly, the expression of several other iron-related genes is influenced in the choroid plexus by the inflammatory stimulus. Using primary cultures of rat choroid plexus epithelial cells, we show that this response is triggered not only directly by LPS but also by molecules whose expression increases in the blood in response to inflammation, such as IL-6. Intracellular conveyors of these signaling molecules include signal transducer and activator of transcription 3, which becomes phosphorylated, and SMAD family member 4, whose mRNA levels increase soon after LPS administration. This novel role for the choroid plexus-CSF barrier in regulating iron metabolism may be particularly relevant to restrict iron availability for microorganism growth, and in neurodegenerative diseases in which an inflammatory underlying component has been reported.
Development of Gonadotropin-Releasing Hormone-1 Secretion in Mouse Nasal Explants
Authors: Constantin Stephanie , Caraty Alain , Wray Susan , Duittoz Anne H.
Published: February 2009

Pulsatile release of GnRH-1 is critical to stimulate gonadotropes of the anterior pituitary. This secretory pattern seems to be inherent to GnRH-1 neurons, however, the mechanisms underlying such episodical release remain unknown. In monkey nasal explants, the GnRH-1 population exhibits synchronized calcium events with the same periodicity as GnRH-1 release, suggesting a link, though the sequence of events was unclear. GnRH-1 neurons in mouse nasal explants also exhibit synchronized calcium events. In the present work, GnRH-1 release was assayed in mouse nasal explants using radioimmunology and its relationship with calcium signaling analyzed. GnRH-1 neurons generated episodical release as early as 3 d in vitro (div) and maintained such release throughout the period studied (3–21 div). The pulse frequency remained constant, suggesting that the pulse generator is operative at an early developmental stage. In contrast, pulse amplitude increased 2-fold between 3 and 7 div, and again between 7 and 14 div, suggesting maturation in synthesizing and/or secretory mechanisms. To evaluate these possibilities, total GnRH-1 content was measured. Only a small increase in GnRH-1 content was detected between 7 and 14 div, whereas a large increase occurred between 14 and 21 div. These data indicate that GnRH-1 content was not a limiting factor for the amplitude of the pulses at 7 div but that the secretory mechanisms mature between 3 and 14 div. The application of kisspeptin-10 revealed the ability of GnRH-1 neurons to integrate signals from natural ligands into a secretory response. Finally, simultaneous sampling of medium and calcium imaging recordings indicated that the synchronized calcium events and secretory events are congruent.
An Occludin-Focal Adhesion Kinase Protein Complex at the Blood-Testis Barrier: A Study Using the Cadmium Model
Authors: Siu Erica R. , Wong Elissa W. P. , Mruk Dolores D. , Sze K. L. , Porto Catarina S. , Cheng C. Yan
Published: February 2009

Several integral membrane proteins that constitute the blood-testis barrier (BTB) in mammalian testes, in particular rodents, are known to date. These include tight junction (TJ) proteins (e.g. occludin, junctional adhesion molecule-A, claudins), basal ectoplasmic specialization proteins (e.g. N-cadherin), and gap junction proteins (e.g. connexin43). However, the regulators (e.g. protein kinases and phosphatases) that affect these proteins, such as their interaction with the cytoskeletal actin, which in turn confer cell adhesion at the TJ, remain largely unknown. We report herein that focal adhesion kinase (FAK) is a putative interacting partner of occludin, but not claudin-11 or junctional adhesion molecule-A. Immunohistochemistry and fluorescence microscopy studies illustrated that the expression of FAK in the seminiferous epithelium of adult rat testes was stage specific. FAK colocalized with occludin at the BTB in virtually all stages of the seminiferous epithelial cycle but considerably diminished in stages VIII–IX, at the time of BTB restructuring to facilitate the transit of primary leptotene spermatocytes. Using Sertoli cells cultured in vitro with established TJ-permeability barrier and ultrastructures of TJ, basal ectoplasmic specialization and desmosome-like junction that mimicked the BTB in vivo, FAK was shown to colocalize with occludin and zonula occludens-1 (ZO-1) at the Sertoli-Sertoli cell interface. When these Sertoli cell cultures were treated with CdCl2 to perturb the TJ-barrier function, occludin underwent endocytic-mediated internalization in parallel with FAK and ZO-1. Thus, these findings demonstrate that FAK is an integrated regulatory component of the occludin-ZO-1 protein complex, suggesting that functional studies can be performed to study the role of FAK in BTB dynamics.
Unexpected Cowboy, Unexpected Indian: The Case of Will Rogers
Authors: Ware Amy M.
Published: February 2009

This brief examination of the early-twentieth-century United States expands academic interpretations of ethnic performance in the popular realm. The case of Will Rogers—Cherokee entertainer, writer, and political pundit—is particularly useful in understanding the representational conflicts, then and now, between cowboys and American Indians in the popular realm. Rogers himself was unexpected; he was both a cowboy and an Indian, a conflation that baffled and titillated his urban fan base. Throughout his early career, from approximately 1903 to 1919, Rogers and his audience grappled with these seemingly conflicting roles of cowboy and Indian, characters steeped in a seeming ethnic conflict yet embodied simultaneously by Rogers. The celebrity's strong ties to Cherokee ranching culture influenced the way he presented himself, yet such performances confounded his fans. In the end, Rogers's self-representation as a cowboy limited the public's recognition of him as an Indian.
Central Mexican Indigenous Coats of Arms and the Conquest of Mesoamerica
Authors: de la Paz María Castañeda
Published: February 2009

In this essay, I will discuss certain coats of arms that the Spanish Crown granted to some of the major central Mexican towns and their rulers for taking part in the conquests of Mexico; these towns and peoples have always been considered as conquered rather than conquerors. I will consider the nature of this participation as well as the historical context in which the requests for the coats of arms were made. My analysis will show an indigenous society that coexisted with its Spanish counterpart, and in order to strengthen its identity in new and confusing times, the indigenous society accepted Spanish cultural elements, creating what we now know as the colonial society of New Spain. The indigenous coats of arms are an excellent example of how native iconographic elements were gradually incorporated into the otherwise strongly European medium, producing a new format.
The physiology of long-distance migration: extending the limits of endurance metabolism
Authors: Weber Jean-Michel
Published: February 2009

Long-distance migrants have evolved specific adaptations that make their athletic records possible. Unique mechanisms explaining their amazing capacity for endurance exercise have now been uncovered, particularly with respect to energy storage, mobilization, transport and utilization. Birds are champions of migration because flying offers a key compromise: it allows more rapid movement than swimming, but has a lower cost of transport than running. High efficiency for muscle contraction, pointed wings, low wingloading, travelling in V-formations, storing fuel as energy-dense lipids and atrophy of non-essential organs are some of their strategies to decrease the cost of transport. The ability to process lipids rapidly also emerges as a crucial component of the migrant phenotype. High lipid fluxes are made possible by lipoprotein shuttles and fatty acid binding proteins (FABPs) that accelerate lipid transport and by upgrading the metabolic machinery for lipolysis and lipid oxidation. Preparation for long flights can include natural doping on n-3 polyunsaturated fatty acids (n-3 PUFAs) from unique invertebrate diets. Muscle performance is improved by restructuring membrane phospholipids and by activating key genes of lipid metabolism through peroxisome proliferator-activated receptors (PPARs). The physiological secret to long migrations does not depend on a single `magic' adaptation but on the integration of multiple adjustments in morphology, biomechanics, behavior,nutrition and metabolism. Research on the physiology of migrants improves the fundamental knowledge of exercise biology, but it also has important implications for wildlife conservation, treating obesity and improving the performance of human athletes.
Behavioral responses of big brown bats to dives by praying mantises
Authors: Ghose Kaushik , Triblehorn Jeffrey D. , Bohn Kari , Yager David D. , Moss Cynthia F.
Published: February 2009

Insectivorous echolocating bats face a formidable array of defenses employed by their airborne prey. One such insect defense is the ultrasound-triggered dive, which is a sudden, rapid drop in altitude,sometimes all the way to the ground. Although many previous studies have investigated the dynamics of such dives and their effect on insect survival rate, there has been little work on how bats may adapt to such an insect defense employed in the middle of pursuit. In this study we investigated how big brown bats (Eptesicus fuscus) adjust their pursuit strategy when flying praying mantises (Parasphendale agrionina) execute evasive,ultrasound-triggered dives. Although the mantis dive occasionally forced the bat to completely abort its chase (25% trials), in a number of cases (75%trials) the bat followed the mantis into the dive. In such cases the bat kept its sonar beam locked onto the target and maneuvered to maintain the same time efficient strategy it adopted during level flight pursuit, though it was ultimately defeated by the dive. This study suggests that although the mantis dive can be effective in evading the bat, it does not always deter the bat from continuing pursuit and, given enough altitude, the bat can potentially capture diving prey using the same flight strategy it employs to intercept prey in level flight.
AMP-activated protein kinase (AMPK) in the rock crab,Cancer irroratus: an early indicator of temperature stress
Authors: Frederich Markus , O'Rourke Michaela R. , Furey Nathan B. , Jost Jennifer A.
Published: February 2009

Exposure of marine invertebrates to high temperatures leads to a switch from aerobic to anaerobic metabolism, a drop in the cellular ATP concentration([ATP]), and subsequent death. In mammals, AMP-activated protein kinase (AMPK)is a major regulator of cellular [ATP] and activates ATP-producing pathways,while inhibiting ATP-consuming pathways. We hypothesized that temperature stress in marine invertebrates activates AMPK to provide adequate concentrations of ATP at increased but sublethal temperatures and that AMPK consequently can serve as a stress indicator (similar to heat shock proteins,HSPs). We tested these hypotheses through two experiments with the rock crab, Cancer irroratus. First, crabs were exposed to a progressive temperature increase (6°C h–1) from 12 to 30°C. AMPK activity, total AMPK protein and HSP70 levels, reaction time, heart rate and lactate accumulation were measured in hearts at 2°C increments. AMPK activity remained constant between 12 and 18°C, but increased up to 9.1(±1.5)-fold between 18 and 30°C. The crabs' reaction time also decreased above 18°C. By contrast, HSP70 (total and inducible) and total AMPK protein expression levels did not vary significantly over this temperature range. Second, crabs were exposed for up to 6 h to the sublethal temperature of 26°C. This prolonged exposure led to a constant elevation of AMPK activity and levels of HSP70 mRNA. AMPK mRNA continuously increased,indicating an additional response in gene expression. We conclude that AMPK is an earlier indicator of temperature stress in rock crabs than HSP70,especially during the initial response to high temperatures. We discuss the temperature-dependent increase in AMPK activity in the context of Shelford's law of tolerance. Specifically, we describe AMPK activity as a cellular marker that indicates a thermal threshold, called the pejus temperature, Tp. At Tp the animals leave their optimum range and enter a temperature range with a limited aerobic scope for exercise. This Tp is reached periodically during annual temperature fluctuations and has higher biological significance than earlier described critical temperatures, at which the animals switch to anaerobic metabolism and HSP expression is induced.
Flight variability in the woodwasp Sirex noctilio (Hymenoptera:Siricidae): an analysis of flight data using wavelets
Authors: Bruzzone Octavio A. , Villacide José M. , Bernstein Carlos , Corley Juan C.
Published: February 2009

We describe flight variability in the woodwasp Sirex noctilioFabricius, 1793 (Hymenoptera: Siricidae) by studying tethered females in a flight mill device and analyzing output data by a time series methodology. Twenty-eight wasps were flown during 24 h-long periods, under controlled temperature and lighting conditions. The maximum distance recorded was 49 km,and mean velocity was 0.37 m s–1. All wasps lost weight during flight (mean weight loss of 10.0% of initial body mass). By using a wavelets analysis on the flight mill time series output, we identified three distinct flight patterns: regular (long acceleration–deceleration spells), periodic (alternation of acceleration–deceleration spells without resting) and pulsating (resting spells interrupted by bursts of flight activity). The first two flight patterns are indistinguishable using traditional flight mill data analysis. Flight patterns for each individual were significantly dependent on wasp body mass, suggesting a relationship with the resources used in flight and their availability. Large females flew sequentially through a regular-periodic-pulsating sequence but medium sized wasps flew mostly with periodic and pulsating patterns. The smallest wasps flew only in a pulsating pattern, being incapable of long, sustained flight. Variability in size and behavior can have significant consequences on population dynamics by determining local and regional dispersal. An important outcome of our work is the introduction of wavelet analysis to study tethered flight data series for the first time. This methodology allowed us to uncover and statistically test individual variability in insect flight characteristics.
Plasma membrane calcium ATPase required for semicircular canal formation and otolith growth in the zebrafish inner ear
Authors: Cruz Shelly , Shiao Jen-Chieh , Liao Bo-Kai , Huang Chang-Jen , Hwang Pung-Pung
Published: February 2009

Fish otoliths consist of >90% calcium carbonate, the accretion of which depends on acellular endolymph. This study confirms the presence of plasma membrane calcium ATPase 1a isoform (Atp2b1a) in the auditory and vestibular system of a teleost fish. As shown by in situ hybridization,zebrafish atp2b1a is expressed mainly in larval otic placode and lateral-line neuromast as well as in the hair cells within the adult zebrafish inner ear chamber. Zebrafish atp2b1a knockdown by antisense morpholinos reduced the number of hair cells and produced malformation of semicircular canals and smaller otoliths. These defects coincide with unbalanced body orientation. The formation of smaller otoliths in atp2b1a morphants may stem from an impairment of calcium supply in the endolymph. However, otolith formation persists in most morphants,suggesting that other zebrafish Atp2b isoforms or paracellular pathways may also transport calcium into the endolymph. These results suggest that Atp2b1a plays an important role for normal development of the auditory and vestibular system as well as calcium transport in the inner ear of zebrafish.
Odour aversion after olfactory conditioning of the sting extension reflex in honeybees
Authors: Carcaud Julie , Roussel Edith , Giurfa Martin , Sandoz Jean-Christophe
Published: February 2009

In Pavlovian conditioning, an originally neutral stimulus (conditioned stimulus or CS) gains control over an animal's reflex after its association with a biologically relevant stimulus (unconditioned stimulus or US). As a consequence, a conditioned response is emitted by the animal upon further CS presentations. In such a situation, the subject exhibits a reflex response, so that whether the CS thereby acquires a positive or a negative value for the animal is difficult to assess. In honeybees, Apis mellifera, an odour(CS) can be associated either with sucrose solution (US) in the appetitive conditioning of the proboscis extension reflex (PER), or with an electric shock (US) in the aversive conditioning of the sting extension reflex (SER). The term `aversive' may not apply to the latter as bees do not suppress SER as a consequence of learning but, on the contrary, start emitting SER to the CS. To determine whether the CS acquires a positive or a negative value in these conditioning forms, we compared the orientation behaviour of freely walking honeybees in an olfactory-cued Y-maze after training them with an odour–sucrose association (PER conditioning) or an odour–shock association (SER conditioning). We show that the same odours can acquire either a positive value when associated to sucrose, or a negative value when associated to an electric shock, as bees respectively approach or avoid the CS in the Y-maze. Importantly, these results clearly establish the aversive nature of SER conditioning in honeybees.
An auxiliary model based on a recursive least-squares parameter estimation algorithm for non-uniformly sampled multirate systems
Authors: Liu Yanjun , Xie Li , Ding Feng
Published: February 2009

The lifted state-space models for a class of multirate systems non-uniformly sampled from their continuous-time systems are derived, and the corresponding input-output relationship is obtained. For unmeasurable information vectors arising in the identification models, this paper gives an auxiliary-model-based recursive least-squares (AM-RLS) identification algorithm to estimate the parameters of non-uniformly sampled data systems using the auxiliary model method. The basic idea is to replace the unknown inner variables in the information vector with the outputs of the auxiliary model. Convergence properties of the algorithm proposed show that the parameter estimation error consistently converges to zero under the generalized excitation condition and bounded noise variance. A simulation example is included.
Assessing the External Validity of Analytical Results from National Brand and Store Brand Competition Models
Authors: Sethuraman Raj
Published: February 2009

This research has three objectives: (i) to compile analytical results on national brand and store brand marketing obtained from mathematical models, (ii) to assess the external validity of those results and thus the applicability of the results to practice, and (iii) to identify avenues for further research on national brand and store brand competition.

A total of 44 analytical results (29 related to retailer strategies and 15 related to manufacturer strategies) are compiled from a survey of literature published between 1966 and 2006. Three criteria are then used to assess the external validity of these results—robustness (R), empirical support (E), and credibility (C) (collectively, REC). Each result is quantitatively assessed (scored) using these three criteria. Robustness is measured as the total number of relevant market conditions for which the result has been shown to hold. Empirical support is measured as the number of independent empirical studies in which the findings are consistent with the analytical result. Credibility is measured as the believability of the theoretical result as perceived by experienced brand managers and retail executives.

Thus, the REC scoring approach represents a triangulation of perspectives—robustness (modeler perspective), empirical support (empiricist perspective), and credibility (managerial perspective). In particular, this research serves in part as a bridge between scholars and practitioners in the context of national brand and store brand marketing.
Quasi-Robust Multiagent Contracts
Authors: Arya Anil , Demski Joel , Glover Jonathan , Liang Pierre
Published: February 2009

A criticism of mechanism design theory is that the optimal mechanism designed for one environment can produce drastically different actions, outcomes, and payoffs in a second, even slightly different, environment. In this sense, the theoretically optimal mechanisms usually studied are not “robust.” To study robust mechanisms while maintaining an expected utility maximization approach, we study a multiagent model in which the mechanism must be designed before the environment is as well understood as is usually assumed. The particular model is of an auction setting with binary private values. Our main result is that if the prior belief about the correlation in the agents' values is diffuse enough, the optimal Bayesian-Nash auction must also satisfy dominant strategy incentive constraints. Furthermore, when the optimal auction does provide dominant strategy incentives, it takes one of two forms: (i) if perfect correlation and negative correlation are excluded as possibilities, the auction incorporates all information about the prior belief over the possible correlations, and (ii) if either perfect correlation or negative correlation is a possibility, the auction does not incorporate any correlation information and can be described as a modified Vickrey auction.
Effectiveness of pupil diameter in a probable‐lie comparison question test for deception
Authors: Webb Andrea K. , Honts Charles R. , Kircher John C. , Bernhardt Paul , Cook Anne E.
Published: February 2009

Purpose. There were three objectives of this study: (1) To assess the possibility of using pupil diameter as an index of deception in the context of a comparison question polygraph test. (2) To determine if pupil diameter would make a significant contribution to an optimal multivariate classification equation in combination with the traditional predictor variables used in field polygraph practice. (3) We explored the possibility of replacing one or more of the traditional predictor variables with pupil diameter.

Methods. We used a laboratory mock crime experiment with 24 participants, half of whom stole $20 (US) from a secretary's purse. Participants were tested with a comparison question test modelled after standard field practice. Physiological measures were taken with laboratory quality instrumentation. Features were extracted from the physiological measures. Those features were subjected to a number of different statistical analyses.

Results. Innocent participants showed larger increases in pupil diameter in response to probable‐lie questions than to relevant questions. Guilty participants did not show differential responding to the question types. The additional of pupil diameter to a multivariate classification model approached, but did not reach significance. Subsequent analyses suggest that pupil diameter might be used to replace the traditional relative blood pressure measure.

Conclusions. Pupil diameter was found to be a significant predictor variable for deception. Pupil diameter may be a possible replacement for the traditional relative blood pressure measure. Additional research to explore that possibility would seem to be warranted.
Nanoessence: God, the first nano assembler
Authors: Thomas Paul
Published: February 2009

The Nanoessence project aims to examine life at a sub-cellular level, re-examining space and scale within the human context. A single HaCat skin cell is analysed with an Atomic Force Microscope (AFM) to explore comparisons between, life and death at a nano level. The humanistic discourse
concerning life is now being challenged by nanotechnological research that brings into question the concepts of what constitutes living. The Nanoessence project research is based on data gathered as part of a residency at SymbioticA, Centre of Excellence in Biological Arts, University of Western
Australia and the Nanochemistry Research Institute, (NRI) Curtin University of Technology. The space of the body can be seen at an atomic level as having no defining boundaries. More generally, molecular self-assembly seeks to use concepts of supramolecular chemistry, and molecular recognition
in particular, to cause single-molecule components to automatically arrange themselves into some useful conformation (reference Wikipedia). Nano assembly, or bottom-up approach, is the construction of a supramolecular chemistry by the assembly of nanoscopic particles, or even atoms and molecules.
The proposal for nanotechnology to reshape nature atom by atom develops an interesting debate as to the constitution of life. The Nanoessence project aims to construct a physical experience to examine this scientific and metaphysical world. Nanoessence is an interactive audio-visual installation.
In the Nanoessence installation the viewer will interface with the visual and sonic presentation through his or her own breath. In the context of the project breath has a strong conceptual and metaphorical link to a Biblical inception of life. The project attempts to maintain a high quality
of authentic data to engage the viewer in a sensorial qualitative experience of quantitative data.
Insights into the polymorphism of the diatomPhaeodactylum tricornutumBohlin
Authors: Tesson Benoit , Gaillard Cedric , Martin-Jézéquel Veronique
Published: February 2009

Phaeodactylum tricornutumis a pleiomorphic diatom that exists in three different forms depending on environmental conditions, viz. oval, fusiform or triradiate. In spite of numerous observations of the three morphotypes, very little information is available about the process of transformation. In this review, we summarize results of previous studies and add new observations on cell wall structure of the three morphotypes and the environmental conditions under which each form appears (for different strains ofPhaeodactylum). New data on the cellular mechanisms of transformation between the three morphotypes and on the differentiation of oval cells are also presented. The ultrastructural morphology of the three morphotypes and strain/genotype-dependent transformations of morphotypes are discussed.
Temperature drop sensor for monitoring kiln drying of lumber
Authors: Elustondo Diego Miguel , Oliveira Luiz , Lister Peter
Published: February 2009

The main objective of this study was to test a new sensor based on the temperature drop across the load (TDAL). The TDAL sensor was designed to determine the transition point between wet and dry wood without any specific information about the drying process. When additional information is available, the TDAL sensor can also be used to monitor drying rate and estimate the drying end-point. In this study, three potential applications of TDAL sensor for lumber drying were explored, namely, to monitor drying rate, to detect the transition point between wet and dry wood, and for determination of drying end-point after calibration. For the first application, it was demonstrated that the transition point between wet and dry wood coincides with the time at which the TDAL decreases with time at a constant logarithmic slope. For the second application, the TDAL sensor was calibrated with nine experimental drying runs, and the end-points determined with the calibrated TDAL sensor did not show a significant difference with the end-points determined by the in-kiln MC meter. Finally, the TDAL sensor was used to monitor drying rate during drying.
How virtuous are gelotophobes? Self- and peer-reported character strengths among those who fear being laughed at
Authors: Proyer René T. , Ruch Willibald
Published: February 2009

In this study we combine variables that make our lives most worth living with the fear of being laughed at. Peterson and Seligman (Character Strengths and Virtues: A Handbook and Classification, American Psychological Association, 2004) suggested a classification of 24 strengths of character and six virtues. The virtues are universally evaluated positively across different countries and cultures. A sample of N = 346 participants allowed the examination of correlations between self- and peer-reported character strengths and gelotophobia. The results indicate that gelotophobia is negatively related to overall virtuousness in self-reports and in the same direction but less so in peer-reports. The rank-order of the character strengths showed that mainly modesty and prudence (both of the virtue of temperance) were positively correlated with gelotophobia (this was also supported by peer-reports). Gelotophobia was mainly negatively related to hope/optimism, curiosity, bravery, love, and zest. The analysis of mean score differences revealed that in some cases the mean scores for the peer-reports of character strengths were higher for the highest scoring gelotophobes than for the less gelotophobic and even lower or equal to the mean scores of the non-gelotophobes. This unexpected finding cannot be fully explained and needs to be addressed in follow-up studies. The results of the study clearly indicate that it is worthwhile to study gelotophobia in its relation to variables of positive psychological functioning.
Ultrasonic Imaging Technique of Spot Weld Structure for a High Strength Galvanized Steel Sheet
Authors: Chen Zhenhua , Shi Yaowu , Zhao Haiyan
Published: February 2009

In this paper, ultrasonic C-scan imagery technique is applied to measure the nugget diameter and image the defects in a spot weld of a high strength galvanized steel sheet. In order to enhance the test precision, the ultrasonic C-scan image is divided into six characteristic color regions and the related A-scan signals are analyzed according to the structural characteristics of the high strength galvanized steel spot weld. The results indicate that the nugget diameter can be measured accurately, and the shape of inner defects of nugget is evaluated based on the C-scan image and the time domain analysis of A-scan signal. The method proposed in the research is not only a comprehensive and visualized method for spot welding evaluation, but also a kind of important auxiliary method for spot weld research since the inner structure of the spot weld can be investigated without devastating it.
Measurement of Board Temperatures during Kiln Drying Using Fiber Optic Sensors
Authors: Sargent R.
Published: February 2009

Fiber optic temperature sensors were investigated as an alternative to thermocouples for measuring the temperature inside pieces of timber during kiln drying. Fiber optic sensors were thought to have some advantages over thermocouples in standard hot air drying, and this increased measurement accuracy would be beneficial for validating the Scion single-board drying model. The fiber optic sensors showed some improvement over the thermocouples, mainly in not conducting heat into the board from the kiln atmosphere. Overall the two types of sensors behaved similarly, and both showed quite different behavior to predictions from the single-board drying model. Due to their higher cost and fragility, the fiber optic sensors are not recommended for applications such as this, where thermocouples could be used instead.
Effects and Interaction of Phenotype and Rearing Density on Growth and Fin Erosion in Rainbow Trout
Authors: Kindschi Greg A , Barrows Frederic T
Published: February 2009

Intensively reared rainbow trout Oncorhynchus mykiss that receive formulated feed frequently exhibit torn, ragged, and eroded fins. To better understand the factors affecting fin erosion, two rainbow trout phenotypes (albino and pigmented) were reared to verify reports that albino rainbow trout suffer less dorsal fin erosion than do pigmented fish. A 12-month study was conducted to evaluate the effects of phenotype, rearing density, and the phenotype × density interaction on fin erosion. Extremes in rearing density were tested using group rearing (maximum density = 200 fish/tank) and individual rearing as the treatments. To evaluate interactive effects of phenotype, rainbow trout were reared either in mixed populations (MPs) containing equal proportions of albino and pigmented fish or in separate populations (SPs) containing only albino or pigmented individuals. Group rearing treatments were each applied to three tanks at 200 first-feeding fish/tank. Eight albino and eight pigmented fish were reared in individual rearing chambers. At 3-month intervals, fish were measured for weight, total length, condition factor, and dorsal and pectoral fin lengths. Survival exceeded 90% in all treatments, but albino fish had lower survival than did pigmented fish in both MPs and SPs. Albino fish from MPs were significantly smaller (37 g) than MP-reared pigmented fish (77.5 g) at the end of the study. Dorsal fin index scores were greater (i.e., indicated less fin erosion) for MP-reared albino fish (7.5%) than for MP-reared pigmented fish (5.6%), but considerable erosion occurred in both phenotypes reared in MPs and SPs. Rainbow trout that were reared individually had complete dorsal fins and pectoral fins during the entire study (i.e., dorsal fin and pectoral fin indices [fin lengths expressed as a percentage of total length] > 11%). This study demonstrates that albinism does not directly affect the occurrence or rate of dorsal fin erosion, but less fin erosion is observed in albino fish than in pigmented fish when reared in MPs.
Alternative Substrates for Culturing the Freshwater Oligochaete Lumbriculus variegatus
Authors: Lasier Peter J
Published: February 2009

The freshwater oligochaete Lumbriculus variegatus is tank cultured to provide organisms for aquatic habitat assessments and regeneration research and to produce a clean source of live food for aquarium fishes. Shredded paper is the typical substrate in small-scale culture of L. variegatus. However, the effort needed to separate large numbers of individuals from decomposing paper can be prohibitive. Burlap and nylon mesh materials were compared with paper as potential alternatives for reducing this effort. Production and the time needed to separate L. variegatus from substrate were compared for 8 weeks among cultures with burlap, mesh, and paper substrates. Cultures with paper increased in number and weight faster than those with burlap or mesh, but cultures using the alternative substrates also expanded their populations quickly. The time required to separate oligochaetes from substrate was initially longer with paper and became significantly longer at 6 weeks as the paper decomposed. Burlap frayed, but mesh exhibited no degradation. Elevated ammonia and nitrite concentrations may have suppressed production in mesh treatments throughout the study, and ammonia was lethal in paper treatments during the final 2 weeks. Slow initial production in burlap treatments may have been due to chemical applications to the fabric, which may limit the utility of burlap as a substrate. Culture systems that maintain adequate water quality could increase production from burlap and mesh substrates to levels observed with paper substrate. Mesh is recommended because it is nontoxic and nonbiodegradable and can significantly reduce the effort required to obtain oligochaetes and to maintain and monitor the cultures.
Effects of water hardness, alkalinity, and dissolved organic carbon on the toxicity of copper to the lateral line of developing fish
Authors: Linbo Tiffany L. , Baldwin David H. , McIntyre Jenifer K. , Scholz Nathaniel L.
Published: February 2009

Conventional water chemistry parameters such as hardness, alkalinity, and organic carbon are known to affect the acutely lethal toxicity of copper to fish and other aquatic organisms. In the present study, we investigate the influence of these water chemistry parameters on short-term (3 h), sublethal (0–40 μg/L) copper toxicity to the peripheral mechanosensory system of larval zebrafish (Danio rerio) using an in vivo fluorescent marker of lateral line sensory neuron (hair cell) integrity. We studied the influence of hardness (via CaCl2, MgSO4, or both at a 2:1 molar ratio), sodium (via NaHCO3 or NaCl), and organic carbon on copper-induced neurotoxicity to zebrafish lateral line neurons over a range of environmentally relevant water chemistries. For all water parameters but organic carbon, the reductions in copper toxicity, although statistically significant, were small. Increasing organic carbon across a range of environmentally relevant concentrations (0.1–4.3 mg/L) increased the EC50 for copper toxicity (the effective concentration resulting in a 50% loss of hair cells) from approximately 12 μg/L to approximately 50 μg/L. Finally, we used an ionoregulatory-based biotic ligand model to compare copper toxicity mediated by targets in the fish gill and lateral line. Relative to copper toxicity via the gill, we find that individual water chemistry parameters are less influential in terms of reducing cytotoxic impacts to the mechanosensory system.
Factors affecting water strider (Hemiptera: Gerridae) mercury concentrations in lotic systems
Authors: Jardine Timothy D. , Kidd Karen A. , Cunjak Richard A. , Arp Paul A.
Published: February 2009

Water striders (Hemiptera: Gerridae) have been considered as a potential sentinel for mercury (Hg) contamination of freshwater ecosystems, yet little is known about factors that control Hg concentrations in this invertebrate. Striders were collected from 80 streams and rivers in New Brunswick, Canada, in August and September of 2004 through 2007 to assess the influence of factors such as diet, water chemistry, and proximity to point sources on Hg concentrations in this organism. Higher than average Hg concentrations were observed in the southwest and Grand Lake regions of the province, the latter being the location of a coal-fired power plant that is a source of Hg (∼100 kg annually), with elevated Hg concentrations in the lichen Old Man's Beard (Usnea spp.) in its immediate vicinity. Across all streams, pH and total organic carbon of water were relatively weak predictors of strider Hg concentrations. Female striders that were larger in body size than males had significantly lower Hg concentrations within sites, suggestive of growth dilution. There was no relationship between percent aquatic carbon in the diet and Hg concentrations in striders. For those striders feeding solely on terrestrial carbon, Hg concentrations were higher in animals occupying a higher trophic level. Mercury concentrations were highly variable in striders collected monthly over two growing seasons, suggesting short-term changes in Hg availability. These measurements highlight the importance of considering both deposition and postdepositional processes in assessing Hg bioaccumulation in this species. They also suggest that striders may be more appropriate as a terrestrial rather than an aquatic Hg sentinel, underscoring the importance of understanding the origin of food for organisms used in contaminant studies.