bluuebunny/crossref_metadata_2025 huggingface dataset:
Segregation of Ipsilateral Retinal Ganglion Cell Axons at the Optic Chiasm Requires the Shh Receptor Boc
Authors: Fabre Pierre J. , Shimogori Tomomi , Charron Frédéric
Published: January 2010

The pattern of contralaterally and ipsilaterally projecting retinal ganglion cell (RGC) axons at the optic chiasm is essential for the establishment of binocular vision. Contralateral axons cross the chiasm midline as they progress from the optic nerve to the optic tract. In contrast, ipsilateral axons deviate from the chiasm and continue in the ipsilateral optic tract, avoiding the chiasm midline. The molecular mechanism underlying this phenomenon is not completely understood. Here we show that the Sonic Hedgehog (Shh) receptor Boc is enriched in ipsilateral RGCs of the developing retina. Together with the presence of Shh at the midline, this complementary expression pattern led us to hypothesize that Shh might repel ipsilateral RGC axons at the chiasm. Consistent with this hypothesis, we found that only Boc-positive RGC axons retractin vitroin response to Shh and that this response is lost in Boc mutant RGCs.In vivo, we show that Boc is required for the normal segregation of ipsilateral axons at the optic chiasm and, conversely, that Boc expression in contralateral RGCs prevents their axons from crossing the optic chiasm. Together, these results suggest that Shh repels ipsilateral RGC axons at the optic chiasm via its receptor Boc. This work identifies a novel molecular pathway required for the segregation of axons at the optic chiasm.
Gain Control in CA1 Pyramidal Cells Using Changes in Somatic Conductance
Authors: Fernandez Fernando R. , White John A.
Published: January 2010

Gain modulation is an important feature of neural activity. Previous work has focused on the ability of background synaptic noise to modulate the slope (i.e., gain) of the frequency–current (f–I) relationship in neurons. To date, demonstrations of gain control that are independent of synaptic noise have been limited. We investigated the effects of increasing somatic conductance in the form of tonic inhibition on the initial and steady-statef–Irelationship of CA1 pyramidal cells. We find that increasing membrane conductance reduces the gain of the steady-statef–Irelationship through a graded increase in the magnitude of spike frequency adaptation. Increased adaptation arises through a conductance-induced depolarization of spike voltage threshold. Thus, by increasing the magnitude of spike frequency adaptation, added conductance can reduce the gain of the steady-statef–Irelationship in the absence of random background membrane fluctuations.
Amygdala Neural Encoding of the Absence of Reward during Extinction
Authors: Tye Kay M. , Cone Jackson J. , Schairer William W. , Janak Patricia H.
Published: January 2010

The basolateral amygdala complex (BLA) has been identified as a critical structure mediating fear extinction. However, little is known about the functional role of neurons in the BLA during the extinction of a reward-seeking behavior. Here, we usedin vivoelectrophysiology procedures in freely moving rats to investigate whether and how the BLA encodes the extinction of responding for sucrose. We recorded 330 neurons from 15 rats during a within-session extinction procedure following training under a partial reinforcement schedule. Several distinct populations of neurons change their response profiles as the rat ceases to respond for the omitted reinforcer. One population of neurons (32 of 330; 10%), which responded selectively to port entries in the presence, but not the absence, of sucrose during maintenance, subsequently developed a phasic response to port entries in the absence of sucrose during the extinction epoch only. The relative proportion of these “reinforcement-omission” neurons per rat was correlated with response intensity during extinction, as well as with the rate at which reward-seeking behavior was extinguished. A subpopulation of neurons responded with opposite phasic changes in activity to port entries in the presence of sucrose and to port entries during extinction, demonstrating that BLA neurons may contribute to the detection of value differences between expected and actual outcomes. Another population of neurons (47 of 330; 14%) responded to the empty port only during extinction. Because BLA neural correlates reflect the omission of an expected reward, these neuronal populations may contribute to the expression of behavior during extinction.
Multiscale Pattern Analysis of Orientation-Selective Activity in the Primary Visual Cortex
Authors: Swisher Jascha D. , Gatenby J. Christopher , Gore John C. , Wolfe Benjamin A. , Moon Chan-Hong , Kim Seong-Gi , Tong Frank
Published: January 2010

Although orientation columns are less than a millimeter in width, recent neuroimaging studies indicate that viewed orientations can be decoded from cortical activity patterns sampled at relatively coarse resolutions of several millimeters. One proposal is that these differential signals arise from random spatial irregularities in the columnar map. However, direct support for this hypothesis has yet to be obtained. Here, we used high-field, high-resolution functional magnetic resonance imaging (fMRI) and multivariate pattern analysis to determine the spatial scales at which orientation-selective information can be found in the primary visual cortex (V1) of cats and humans. We applied a multiscale pattern analysis approach in which fine- and coarse-scale signals were first removed by ideal spatial lowpass and highpass filters, and the residual activity patterns then analyzed by linear classifiers. Cat visual cortex, imaged at 0.3125 mm resolution, showed a strong orientation signal at the scale of individual columns. Nonetheless, reliable orientation bias could still be found at spatial scales of several millimeters. In the human visual cortex, imaged at 1 mm resolution, a majority of orientation information was found on scales of millimeters, with small contributions from global spatial biases exceeding ∼1 cm. Our high-resolution imaging results demonstrate a reliable millimeters-scale orientation signal, likely emerging from irregular spatial arrangements of orientation columns and their supporting vasculature. fMRI pattern analysis methods are thus likely to be sensitive to signals originating from other irregular columnar structures elsewhere in the brain.
Metabotropic Glutamate Receptor-Mediated Cell Signaling Pathways Are Altered in a Mouse Model of Huntington's Disease
Authors: Ribeiro Fabiola M. , Paquet Maryse , Ferreira Lucimar T. , Cregan Tamara , Swan Patrick , Cregan Sean P. , Ferguson Stephen S. G.
Published: January 2010

Huntington's disease (HD) is an autosomal-dominant neurodegenerative disorder caused by a polyglutamine expansion in the huntingtin protein (Htt). Group I metabotropic glutamate receptors (mGluRs) are coupled to Gαqand play an important role in neuronal survival. We have previously demonstrated that mGluRs interact with Htt. Here we used striatal neuronal primary cultures and acute striatal slices to demonstrate that mGluR-mediated signaling pathways are altered in a presymptomatic mouse model of HD (HdhQ111/Q111), as compared to those of control mice (HdhQ20/Q20). mGluR1/5-mediated inositol phosphate (InsP) formation is desensitized in striatal slices fromHdhQ111/Q111mice and this desensitization is PKC-mediated. Despite of decreased InsP formation, (S)-3,5-dihydroxylphenylglycine (DHPG)-mediated Ca2+release is higher inHdhQ111/Q111than inHdhQ20/Q20neurons. Furthermore, mGluR1/5-stimulated AKT and extracellular signal-regulated kinase (ERK) activation is altered inHdhQ111/Q111mice. Basal AKT activation is higher inHdhQ111/Q111neurons and this increase is mGluR5 dependent. Moreover, mGluR5 activation leads to higher levels of ERK activation inHdhQ111/Q111than inHdhQ20/Q20striatum. PKC inhibition not only bringsHdhQ111/Q111DHPG-stimulated InsP formation toHdhQ20/Q20levels, but also causes an increase in neuronal cell death inHdhQ111/Q111neurons. However, PKC inhibition does not modify neuronal cell death inHdhQ20/Q20neurons, suggesting that PKC-mediated desensitization of mGluR1/5 inHdhQ111/Q111mice might be protective in HD. Together, these data indicate that group I mGluR-mediated signaling pathways are altered in HD and that these cell signaling adaptations could be important for striatal neurons survival.
Wild-Type Cone Photoreceptors Persist Despite Neighboring Mutant Cone Degeneration
Authors: Lewis Alaron , Williams Philip , Lawrence Owen , Wong Rachel O. L. , Brockerhoff Susan E.
Published: January 2010

In many retinal diseases, the malfunction that results in photoreceptor loss occurs only in either rods or cones, but degeneration can progress from the affected cell type to its healthy neighbors. Specifically, in human and mouse models of Retinitis Pigmentosa the loss of rods results in the death of neighboring healthy cones. Significantly less is known about cone-initiated degenerations and their affect on neighboring cells. Sometimes rods remain normal after cone death, whereas other patients experience a loss of scotopic vision over time. The affect of cone death on neighboring cones is unknown. The zebrafish is a cone-rich animal model in which the potential for dying cones to kill neighboring healthy cones can be evaluated. We previously reported that the zebrafish cone phosphodiesterase mutant (pde6cw59) displays a rapid death of cones soon after their formation and a subsequent loss of rods in the central retina. In this study we examine morphological changes associated with cone deathin vivoinpde6cw59fish. We then use blastulae transplantations to create chimeric fish with a photoreceptor layer of mixed wild-type (WT) andpde6cw59cones. We find that the death of inoperative cones does not cause neighboring WT cone loss. The survival of WT cones is independent of transplant size and location within the retina. Furthermore, transplanted WT cones persist at least several weeks after the initial death of dysfunctional mutant cones. Our results suggest a potential for the therapeutic transplantation of healthy cones into an environment of damaged cones.
Neonatal Cerebral Hypoxia–Ischemia Impairs Plasticity in Rat Visual Cortex
Authors: Failor Samuel , Nguyen Vien , Darcy Daniel P. , Cang Jianhua , Wendland Michael F. , Stryker Michael P. , McQuillen Patrick S.
Published: January 2010

Ocular dominance plasticity (ODP) following monocular deprivation (MD) is a model of activity-dependent neural plasticity that is restricted to an early critical period regulated by maturation of inhibition. Unique developmental plasticity mechanisms may improve outcomes following early brain injury. Our objective was to determine the effects of neonatal cerebral hypoxia–ischemia (HI) on ODP. The rationale extends from observations that neonatal HI results in death of subplate neurons, a transient population known to influence development of inhibition. In rodents subjected to neonatal HI and controls, maps of visual response were derived from optical imaging during the critical period for ODP and changes in the balance of eye-specific response following MD were measured. In controls, MD results in a shift of the ocular dominance index (ODI) from a baseline of 0.15 to −0.10 (p< 0.001). Neonatal HI with moderate cortical injury impairs this shift, ODI = 0.14 (p< 0.01). Plasticity was intact in animals with mild injury and in those exposed to hypoxia alone. Neonatal HI resulted in decreased parvalbumin expression in hemispheres receiving HI compared with hypoxia alone: 23.4 versus 35.0 cells/high-power field (p= 0.01), with no change in other markers of inhibitory or excitatory neurons. Despite abnormal inhibitory neuron phenotype, spontaneous activity of single units and development of orientation selective responses were intact following neonatal HI, while overall visual responses were reduced. Our data suggest that specific plasticity mechanisms are impaired following early brain injury and that the impairment is associated with altered inhibitory neuronal development and cortical activation.
Krüppel-like factor 4 is widely expressed in the mouse male and female reproductive tract and responds as an immediate early gene to activation of the protein kinase A in TM4 Sertoli cells
Authors: Godmann M , Kosan C , Behr R
Published: January 2010

Krüppel-like factor 4 (KLF4) is a zinc finger transcription factor critically involved in cell proliferation, differentiation, and carcinogenesis. Recently, KLF4 has also been used for the generation of induced pluripotent stem cells. In this study, we analyzedKlf4expression in different mouse tissues using northern blot analysis and immunohistochemistry. Focusing on the male and female reproductive tract, we showed for the first time that KLF4 is expressed in the epithelia of the murine uterus and the vagina. In the male reproductive tract, we detected KLF4 in the epithelia of the epididymis, ductus deferens, coagulating gland, and the penis. As KLF4 is strongly inducible by FSH signaling in Sertoli cells and as this transcription factor is also involved in Sertoli cell development, we employed the mouse Sertoli cell line TM4 as a model system to investigate i) the induction kinetics ofKlf4upon activation of the cAMP/protein kinase A pathway by forskolin and ii) the effects ofKlf4induction on TM4 cell cycle progression. Interestingly,Klf4mRNA and protein were rapidly but transiently induced, reaching peak levels after 90–120 min and declining to basal levels within 4 h. Compared with the inducible cAMP early repressor, an immediate early response gene, the induction kinetics ofKlf4is much faster. In conclusion,Klf4is an immediate early gene in TM4 cells and its expression in several epithelia of the male and female reproductive tract suggests an important role ofKlf4in mouse reproductive functions.
Gnatostomíase no Brasil: relato de caso
Authors: Dani Christiane Maria de Castro , Mota Karina Frias , Sanchotene Paola Vizcaichipi , Maceira Juan Piñeiro , Maia Cláudia Pires Amaral
Published: January 2010

A gnatostomíase é parasitose endêmica em alguns países asiáticos, causada pela ingestão da larva do nematódio Gnathostoma sp, que pode ocorrer no consumo de carne crua de peixes de água doce. Atinge vários órgãos, entre eles a pele, manifestando-se frequentemente como lesão subcutânea migratória. Países da América Central e do Sul como México e Peru vêm apresentando número crescente de casos da doença desde 1970. Este trabalho registra o primeiro caso notificado e publicado no Brasil e alerta para o surgimento dessa doença em áreas anteriormente não endêmicas. Relata-se caso de paciente, com história de viagem ao Peru, que evoluiu com quadro cutâneo compatível com gnatostomíase.
Incipient Speciation inStrauzia longipennis(Diptera: Tephritidae): Two Sympatric Mitochondrial DNA Lineages in Eastern Iowa
Authors: Axen Heather J , Harrison Jessica L , Gammons John R , McNish Ian G , Blythe Laura D , Condon Marty A
Published: January 2010

Strauzia longipennis (Wiedemann) (Diptera: Tephritidae) is a notoriously variable species. Seven varieties were once recognized. Three varieties were elevated to species status. The status of the other four varieties, including the synonyms for S. longipennis, has been contested. Such taxonomic instability, particularly when associated with variable patterns of host use, suggests that S. longipennis may represent a dynamic complex of host-associated populations in the process of divergence. To detect evidence of genetic differentiation indicating genetically distinct sympatric populations of S. longipennis, we sequenced a fragment of cytochrome c oxidase subunit I of mitochondrial DNA of S. longipennis from two sites (three habitats) in eastern Iowa. At each site, we found two genetically and morphologically distinct sympatric populations. One corresponds to morphological descriptions of S. longipennis variety typica (Loew). The other corresponds to descriptions of S. longipennis variety vittigera (Loew). High levels of genetic differentiation between these divergent sympatric populations suggest the populations might represent host races or incipient species.
Mate Recognition and Sex Differences in Cuticular Hydrocarbons of the Diurnal Firefly Ellychnia corrusca (Coleoptera: Lampyridae)
Authors: Ming Qing-Lei , Lewis Sara M
Published: January 2010

There are several genera of diurnally active fireflies (Coleoptera: Lampyridae), and these adults generally do not produce bioluminescent signals. We investigated whether contact sex pheromones play a role in mate recognition in the diurnal firefly Ellychnia corrusca (L.). In laboratory behavioral assays, after antennal contact >70% of males attempted copulation with freeze-killed females, whereas no copulation attempts occurred when freeze-killed females had been washed with hexane. This shows that E. corrusca mate recognition relies on contact chemoreception and suggests that male mating responses are mediated by contact sex pheromones on the female cuticle. Using direct contact solid phase microextraction (SPME) and solvent extraction, we sampled cuticular hydrocarbons (CHCs) from both sexes of E. corrusca adults. Gas chromatography-mass spectrometry showed that SPME was more effective than solvent extraction in detecting CHCs (a two-fold increase in the number of compounds detected). Although E. corrusca males and females showed similar CHCs profiles, we documented several quantitative and qualitative differences between the sexes that may play a role in mate recognition. This report provides the first behavioral evidence for the existence of contact sex pheromones in any diurnal firefly.
An Evaluation of a Movement Imagery Training Scheme
Authors: McAvinue Laura P. , Robertson Ian H.
Published: January 2010

Movement imagery has become an important tool in a variety of fields but individual differences in imagery ability mean that some participants, with weak imagery abilities, may not be able to engage in imagery tasks or programs. In this article we present an evaluation of a training scheme designed to improve movement imagery ability. The scheme lasted 4 weeks, involving four individual training sessions lasting 1–1 1/2 hours each and homework. The scheme emphasized relaxation and kinaesthetic awareness, external and internal perspective movement imagery, prospective action judgments, and motorically driven perceptual decisions. Ten participants, of mean age 35 ( SD = 11.97), participated in the training scheme and 12 participants, of mean age 35.33 ( SD = 13.38), participated in the control group. The performance of the trainee group was compared to the performance of the control group on a series of visual and movement imagery measures, completed before and after training. In comparison to controls, trainees improved significantly on a number of key measures of movement imagery ability but did not improve on any measure of visual imagery ability. The results demonstrated that explicit and implicit aspects of movement imagery ability can be improved through imagery training.
Altered States of Consciousness and Mystical Experiences during Sensory Isolation in Flotation Tank: Is the Highly Sensitive Personality Variable of Importance?
Authors: Kjellgren Anette , Lindahl Andreas , Norlander Torsten
Published: January 2010

The aim of this study was to investigate if the highly sensitive personality variable affects the occurrence of mystical experiences and degree of altered states of consciousness during sensory isolation in flotation-tank. Forty-eight persons (20 males, 28 females) were included. Background variables and the Highly Sensitive Personality Scale (HSP) were assessed. The independent variable was derived from this scale, where two groups were formed: low sensitivity and high sensitivity. The treatment lasted 45 minutes in the flotation tank. Dependent variables were assessed through scales measuring mystical experiences and degree of altered states of consciousness. The group with highly sensitive persons experienced significantly more mystical experiences and higher degree of altered states of consciousness during the treatment compared to the other group. Also, the highly sensitive persons exhibited more stress and anxiety at arrival, but no differences in depression and optimism were found between the groups.
Hepatoprotective Evaluation of Scoparia dulcis L.
Authors: Sahoo Atish Kumar , Madhavan V.
Published: January 2010

Scoparia dulcis L. (Family: Scrophulariaceae) is an herb native to America and in tropics and widely present in Karnataka, India. This plant has been traditionally used to cure many liver aliments. Phytochemical screening has revealed that the plant contains diterpenoids, flavonoids, tannins, alkaloids, triterpenes, hexacosonol, ?-sitosterol, ketone, dulcitone and amellin. Liver cirrhosis represents the common pathological outcome for the majority of chronic liver insults (e.g. alcohol, autoimmune, or viral injury, even oxidative stress). The therapeutic potential of antioxidants with respect to liver toxicity has been realized marginally so far. In the present study the in vitro antioxidant activity and antihepatotoxic activity of hydroalcoholic extract of S. dulcis (HASD) was investigated against CCl4 induced liver damage in rats. The extracts showed in vitro free radical scavenging activity against DPPH free radicals. The in vivo hepatoprotective activity study for HASD extracts at an oral dose of 500 mg/kg and 800 mg/kg, exhibited a significant (P<0.01) protective effect against CCl4 induced changes in serum glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT), serum alkaline phosphatase (ALP), total billirubin and an increased level of total protein in treated rats and on liver histopathology, as compared to positive control. The above results are comparable to the standard, silymarin. In conclusion, the hydroalcoholic extract of S. dulcis exhibits significant hepatoprotective activity against CCl4 induced liver damage in rats because of their free radical scavenging ability.
A Study on Multiband PSS Coordination
Authors: Ramirez Juan M , Correa-Gutierrez Rosa E , Castrillon-Gutierrez Neby J
Published: January 2010

The purpose of this paper is to present results for power system stabilizers (PSS) coordination in multi-machine applications. Due to their versatility, multiband power system stabilizers (MB_PSS) have been employed to enhance the power oscillations damping. The problem at hand is to minimize an objective function, which is solved by the conventional differential evolution (DE) algorithm. Results for an equivalent of the Mexican power system are exhibited showing the improvement on the electromechanical transient.
Influence of Temperature and Pressure on the Non-Catalytic Partial Oxidation of Natural Gas
Authors: Brüggemann Philipp , Seifert Peter , Meyer Bernd , Müller-Hagedorn Matthias
Published: January 2010

The influence of temperature and pressure on the non-catalytic partial oxidation and reforming of natural gas in an entrained-flow reactor under non-equilibrium conditions has been investigated experimentally in pilot scale.As thermochemical equilibrium suggests, the methane conversion increases drastically with temperature, but does not reach equilibrium in the investigated range of parameters (Tmax = 1450 °C; 30 bar (3 MPa) < p(g) < 100 bar (10 MPa), 5 s < ? < 20 s). A practical method to describe the non-equilibrium state of a partial oxidation product gas at high temperatures due to kinetic limitations and/or mixing conditions within a reactor is by calculating apparent equilibrium temperatures Teq,ap for the main global kinetic reactions from the measured concentrations of the gas. The temperature difference between Teq,ap and the measured reactor outlet temperature Tex results in the temperature differental approach (?TApp = Teq,ap - Tex).In this paper, typical parameters influencing ?TApp for the methane reforming reaction (temperature T, pressure p, residence time ?) were examined. ?TApp was found in the range between -300 K and -50 K in non-catalytic partial oxidation. Its absolute value decreases with increasing pressure and decreasing ratio of steam to fuel carbon H2O : Cf , but is just weakly dependent on the reactor temperature Tex in a range from 1100-1450 °C. The results were used for the evaluation and further development of a model combining kinetics and residence time behaviour of the non-catalytic partial oxidation and reforming of natural gas.For comparison, results from catalytic autothermal reforming of natural gas and non-catalytic partial oxidation of liquid hydrocarbons are also presented.
Sequential Auctions with Multi-Unit Demands
Authors: Rodriguez Gustavo E
Published: January 2010

I study sequential second price auctions with multi-unit demands in a complete information setting, focusing on cases in which payoffs are non-separable as a consequence of decreasing marginal values. At the equilibrium outcome a buyer behaves as a monopsonist with respect to the residual supply, which raises the possibility of inefficiency. Moreover, I construct an equilibrium that exhibits declining prices, a fact that has been empirically observed.
Redundancy in Systems Which Entertain a Model of Themselves: Interaction Information and the Self-Organization of Anticipation
Authors: Leydesdorff Loet
Published: January 2010

Mutual information among three or more dimensions (μ* = –Q) has been considered as interaction information. However, Krippendorff [1,2] has shown that this measure cannot be interpreted as a unique property of the interactions and has proposed an alternative measure of interaction information based on iterative approximation of maximum entropies. Q can then be considered as a measure of the difference between interaction information and redundancy generated in a model entertained by an observer. I argue that this provides us with a measure of the imprint of a second-order observing system—a model entertained by the system itself—on the underlying information processing. The second-order system communicates meaning hyper-incursively; an observation instantiates this meaning-processing within the information processing. The net results may add to or reduce the prevailing uncertainty. The model is tested empirically for the case where textual organization can be expected to contain intellectual organization in terms of distributions of title words, author names, and cited references.
3-Methyl-4,5,6,7-tetrahydro-1-benzothiophene-2-carboxylic Acid
Authors: Jayaraman Sembian Ruso , Sridharan Madhavan , Nagappan Rajendiran
Published: January 2010

3-Methyl-4,5,6,7-tetrahydro-1-benzothiophene-2-carboxylic acid was synthesized chemoselectively from 3-formyl-4,5,6,7-tetrahydro-1-benzothiophene-2-carboxylic acid, using Et3SiH/I2 as a reducing agent. The title compound was characterized by IR, 1H NMR, 13C NMR and LCMS.
The Timing of Antidepressant Effects: A Comparison of Diverse Pharmacological and Somatic Treatments
Authors: Machado-Vieira Rodrigo , Baumann Jacqueline , Wheeler-Castillo Cristina , Latov David , Henter Ioline D. , Salvadore Giacomo , Zarate Carlos A.
Published: January 2010

Currently available antidepressants used to treat major depressive disorder (MDD) unfortunately often take weeks to months to achieve their full effects, commonly resulting in considerable morbidity and increased risk for suicidal behavior. Our lack of understanding of the precise cellular underpinnings of this illness and of the mechanism of action of existing effective pharmacological treatments is a large part of the reason that therapies with a more rapid onset of antidepressant action (ROAA) have not been developed. Other issues that need to be addressed include heterogeneous clinical concepts and statistical models to measure rapid antidepressant effects. This review describes the timing of onset of antidepressant effects for various therapies used to treat MDD. While several agents produce earlier improvement of depressive symptoms (defined as occurring within one week), the response rate associated with such agents can be quite variable. These agents include both currently available antidepressants as well as other pharmacological and non-pharmacological interventions. Considerably fewer treatments are associated with ROAA, defined as occurring within several hours or one day. Treatment strategies for MDD whose sustained antidepressant effects manifest within hours or even a few days would have an enormous impact on public health.
Collaborative Localization in Wireless Sensor Networks via Pattern Recognition in Radio Irregularity Using Omnidirectional Antennas
Authors: Jiang Joe-Air , Chuang Cheng-Long , Lin Tzu-Shiang , Chen Chia-Pang , Hung Chih-Hung , Wang Jiing-Yi , Liu Chang-Wang , Lai Tzu-Yun
Published: January 2010

In recent years, various received signal strength (RSS)-based localization estimation approaches for wireless sensor networks (WSNs) have been proposed. RSS-based localization is regarded as a low-cost solution for many location-aware applications in WSNs. In previous studies, the radiation patterns of all sensor nodes are assumed to be spherical, which is an oversimplification of the radio propagation model in practical applications. In this study, we present an RSS-based cooperative localization method that estimates unknown coordinates of sensor nodes in a network. Arrangement of two external low-cost omnidirectional dipole antennas is developed by using the distance-power gradient model. A modified robust regression is also proposed to determine the relative azimuth and distance between a sensor node and a fixed reference node. In addition, a cooperative localization scheme that incorporates estimations from multiple fixed reference nodes is presented to improve the accuracy of the localization. The proposed method is tested via computer-based analysis and field test. Experimental results demonstrate that the proposed low-cost method is a useful solution for localizing sensor nodes in unknown or changing environments.
Eco-nomics: Are the Planet-Unfriendly Features of Capitalism Barriers to Sustainability?
Authors: Singer Merrill
Published: January 2010

This paper argues that there are essential features of capitalist modes of production, consumption, and waste dispersal in interaction with the environment and its built-in systemic features that contradict long-term sustainable development. These features include: (a) contradictions in the origin and meaning of sustainability; (b) the central role of the productivity ethic in capitalism and its reproduction in emergent green capitalism; (c) the commodification of nature and the continued promotion of expanding consumption; (d) globalism and the contradictions of continued Western-style development; and (e) the emergence of anthropogenic ecocrises and crises interaction. In light of these barriers to capitalist sustainability, an alternative social narrative is needed, one that embraces values, understandings, and relationships that promote ecological stability and justice.
Liver Transient Elastography (Fibroscan®): A Place in the Management Algorithms of Chronic Viral Hepatitis
Authors: Scott David R , Levy Miriam T
Published: January 2010

Treatment guidelines are continuously evolving in chronic viral hepatitis, taking into consideration our greater understanding of natural history and therapeutic efficacy and safety. Key in the decision making process is an assessment of liver injury. Traditionally, liver biopsy has provided this information; however, this is an invasive procedure and not completely reliable. Liver transient elastography (Fibroscan®) is exciting new technology that allows estimation of hepatic fibrosis through measurement of liver stiffness. It is acceptably accurate, safe, cheap, quick and widely applicable, and can reduce the need for liver biopsy in chronic hepatitis. In chronic hepatitis C, it can identify those most likely to benefit from treatment, as well as those with cirrhosis who require more specific care. In chronic hepatitis B, it could screen groups previously excluded from treatment (normal alanine aminotransferase and low DNA) to identify the subgroup that would benefit from therapy. It cannot replace biopsy in all settings, but it will narrow the group who do require biopsy, and provide information on liver damage in patients for whom biopsy would probably not have been considered.
Pressure Testing: Best Practices
Authors: Hardy Kevin , James Matt
Published: January 2010

AbstractSuccess below the seas comes from careful preparation topside. Pressure testing remains one of the most useful tools designers have available to assure their systems function as intended, whether a company chooses to have in-house pressure test capability or to work
with a commercial test facility.Capt. Don Walsh, pilot of the bathyscaph Trieste on its historic two-man dive to the floor of the Challenger Deep in the Mariana Trench, said with a grin, “Successful operations depend upon a Skill-to-Luck ratio. While luck is important, you
always want skill to be more than 50%.”Given the limited availability of ship time, the danger to personnel in close quarters onboard ship or in a submersible, the high cost of ship operations and equipment, and the long lead time of grant and project funding, pressure testing makes
sense to validate system integrity before deployment. Simply put, equipment should not see pressure for the first time on its first operational deployment. Pressure testing is a vital environmental check of mechanical integrity, analogous to electronics and software burn-in. Ideally, pressure
testing will simulate the actual conditions of deployment and operation. A solid test provides the operator and deck crew confidence in the system being deployed.While pressure testing will appear to add time and cost, in practice it saves both by eliminating failure modes, some potentially
catastrophic, while offshore.This technical note is intended to summarize current best practices in pressure testing for engineers and programs managers new to the field, including tips for coordinating work with pressure test facilities. The lessons are based on the authors’ combined
experience as users and operators of pressure test facilities.
Flotation in Ocean Trenches Using Hollow Ceramic Spheres
Authors: Weston Steve , Olsson Mark , Merewether Ray , Sanderson John
Published: January 2010

AbstractSpherical flotation units of 99.9% Al2O3 ceramic have been successfully produced by DeepSea Power & Light for application to ocean trench systems, such as the Woods Hole Oceanographic Institution (WHOI) hybrid remotely operated vehicle (HROV)
Nereus and other high-performance systems requiring maximum buoyancy with minimum air weight. WHOI successfully operated their HROV in the Mariana Trench Challenger Deep in Summer 2009, scooting across the trench floor for a total of 11 h at 36,000 feet (11,000 m). More than 1,750 3.6-inch
(91.45 mm), OD seamless hollow ceramic spheres, each generating 0.6 lb (272 g) of lift, provided Nereus its buoyancy. The spheres, with a 0.34 weight/displacement ratio, withstood proof testing to 30,000 psi (207 MPa), 1,000 h of sustained pressurization to 25,000 psi and 10,000 pressure
cycles to 20,000 psi (138 MPa). In addition, each of the WHOI spheres withstood 15 h at 18 ksi static pressure hold. When encased in a 0.2-inch thick buoyant elastomeric boot, they withstood impact on a concrete floor from a 6-foot elevation. An extensive quality assurance (QA) procedure is
applied to 100% of manufactured spheres, with strict adherence to tight dimensional and thickness specifications as well as pressure test acoustic emission criteria (Figure 1).FIGURE 1Engineers
at WHOI demonstrate the toughness of DSPL’s jacketed hollow ceramic spheres they use to provide lift at extreme pressures for their deep diving HROV, Nereus. (Photo by Tom Kleindinst, WHOI).DeepSea Power
& Light has additionally demonstrated the process for casting larger alumina ceramic spheres with an 8.6-inch (218.4 mm) outside diameter for the whole range of ocean depths from 10,000 feet (3000 m) to 36,000 feet (11,000 m). The larger spheres were successfully used offshore by Scripps
Institution of Oceanography/UCSD in summer 2005 in an experimental free vehicle sediment sampler that impacted the seafloor at 2 m/s at a water depth of 2,200 m, dropped a weight, then rebounded to the surface with its cargo of sediment.
Tetrastichus garryana Burks (Hymenoptera: Eulophidae) Parasite of an Oak Gall-Wasp, Besbicus mirabilis (Kinsey)
Authors: Evans David
Published: January 2010

The life history and the later larval instars of Tetrastichus garryana Burks (Hymenoptera: Eulophidae) are described and figured. The parasite has been collected from several species of oak gall cynipids, to which general group it seems to be restricted. In British Columbia it is most commonly associated with the gall-wasp Besbicus mirabilis (Kinsey).
Preservative Discoloration in Lepidopterous Larvae
Authors: MacKay Margaret Rae
Published: January 2010

It is well known that the membranous areas of lepidopterous larvae may lose much of their colour pigment when the larvae are preserved, but it appears to be less widely recognized that the larvae themselves mav also be burned by the preservative. A pale larva, one that is greenish or yellowish when alive and almost cream-coloured when preserved, becomes brownish under these circumstances. The colour change may be so pronounced as to result in mis-identification of the species, and a colour description based on a series of such larvae may be most inaccurate.
Laboratory and Field Investigations of the Effect of Temperature on the Development of Neodiprion sertifer (Geoff.) in the Cocoon
Authors: Wallace D. R. , Sullivan C. R.
Published: January 2010

Laboratory studies show that diapause, or eonymphal development, has a temperature optimum approximating 8 °C, at which some 29 days are required for its completion. The optimum for morphogenesis is 22 °C. About 33 and 37 days for females and males, respectively, are required for its completion.

Field data for three sites with mean temperatures near 22, 19, and 16 °C. show that emergence took place earliest at the intermediate site and latest at the exposed site, which experienced the highest mean temperature. Emergence of males and females overlapped, but at the shaded site, having the lowest mean temperature, females emerged sooner than males, whereas the reverse was observed at the exposed site.

The length of the eonymphal stage in the field is dependent upon site temperature and can be predicted from laboratory data. The duration of the pronymphal stage is dependent not only upon site temperature, but also upon the length of time which has been required for eonymphal development. Thus the longer the eonymphal period. the shorter the pronymphal period. This compensatory mechanism is probably due to a temperature effect on any morphogenesis that takes place concurrently with diapause.
Nectar of Peach Leaf Glands as Insect Food
Authors: Putman Wm. L.
Published: January 2010

The secretion of the extrafloral nectaries on peach leaves is consumed by many insects. It is especially important as food for some stages of a number of predators and parasites that usually feed on honeydew and blossoms, but it cannot completely replace these foods for those species requiring nitrogenous components.
The Immature Stages of the Canadian Species of Pero Herrich-Schaeffer (Lepidoptera: Geometridae)
Authors: McGuffin W. C.
Published: January 2010

The immature stages of five Canadian species of Pero Herrich-Schaeffer are described. These species arc P. bebrensarius Packard, P. bonestarim Walker, P. mizon Ritidge, P. morrisonaius Henry Edwards, and P. occidentalis pnckardi Cassino and Swett. Three colour patterns have been noted in the larvae of P. mizon and P. morrisovarius but only nne in each of P. behreniarius, P. bonestarius and P. occidtmtalis packardi. Brief accounts of the life histories and habits of the species are presented together with a key to the mature larvae.
The North American Species in Groups II and III of Ips De Geer (Coleoptera: Scolytidae)
Authors: Hopping G. R.
Published: January 2010

North American Ips of Group II (Hopping, 196îb) are I. emarginatus (Leconre) and I. knattsi Swaine. They are the only Ips having the third declivital spine emarginate ar the tip. They breed in various species of pine. The distribution of I. emarginatus is from southern British Columbia to California and eastward to Montana. I. knausi is found in Colorado, New Mexico and Arizona. A key to the species is given. I. plastographus (Leconte) is the sole representative of Group III. It is the only four-spined Ips with the sutures of the autennal club strongly angled at the middle. I. plastographus breeds in species of pine. It occurs from southern British Columbia southward in the western United States and through Mexico into Guatemala. Hosts and more detailed distributions are given for species in Groups IT and III.
Predicting the Size of European Corn Borer Infestations (Ostrinia nubilalis Hbn.)
Authors: Barlow C. A.
Published: January 2010

A method of forecasting the size of first-generation or summer infestations of Ostrinia nubilalis in Kent County, Ontario, is described. A function is derived from partial regression analysis relating the estimated size of the expected summer infestation to (1) the number of females caught in a light-trap during the first or spring flight, and (2) average rainfall per day during the first flight. The function explains 94% of the observed variation in estimated size of first-generation infestations in this area between 1947 and 1961. A means of categorizing the estimated size of the predicted infestation based on the frequency distribution of previously estimated infestations is also described. Methods of sampling and estimating population size and the applicability of the predictive equation to other environments are discussed.
The Occurrence of Nemobius fasciatus (DeGeer) in Newfoundland (Orthoptera: Gryllidae: Nemobiinae)
Authors: Vickery V. R.
Published: January 2010

Hebard (1915) and J. W. H. Rehn (1939 and 1939a) listed species of Orthoptera from Newfoundland but neither author reported any species of Gryllidae. Walker (1915) did not list any members of this family as inhabiting the Magdalen Islands.

The first record of a cricket from Newfoundland was by Ander (1960) who recorded two immature females from Shoal Harbour, July 27, 1951. He somewhat doubtfully assigned these specimens to Nemobius fasciatus (DeGeer), stating: “I suppose that the specimens belong to the species Nemobius fasciatus (Degeer), widely distributed in North America, which is common in Nova Scotia (Piers 1918). The specimens agree very well with the description of fasciatus in Morse (1920) and Blatchley (1920), and as it is the only Nemobius known from Nova Scotia I have good reasons to suppose that the larvae belong to the species mentioned.”
A New Birch Aphid from Central New Brunswick (Homoptera: Aphididae)
Authors: MacGillivray M.E.
Published: January 2010

In this paper a new species of Glyphina Koch is described. This genus has not been previously recorded from the Western Hemisphere.
Environmental Causes of Variation in the Sex Ratio of an Arrhenotokous Insect,Dahlbominus fuliginosus(Nees) (Hymenoptera: Eulophidae)
Authors: Wilkes A.
Published: January 2010

Unlike most other arrhenotokous species,D.fuliginosusfemales cannot control fertilization of their eggs and in an optimal environment the sex ratio of any one strain is constant. Variations in the sex ratio occurred when unfavourable environmental conditions prevailed before, during and immediately following mating. Beyond half their life span, males inseminated less than half the females they mated and the inseminated females produced fewer female progeny. Temperatures above 27 °C. during post-embryonic development sterilized otherwise functional males but had much less effect on females. Structural defects of either sex were rare. Mating was successful only within the normal range for optimal adult activity. Although females were inseminated by more than one male, the sex ratio of their progeny was not affected. Larval mortality from superparasitism above 65 larvae per host differentially favoured survival of males, heightening the incidence of pairing in nature at low host population densities. The percentage females was significantly reduced when oviposition was interrupted, or delayed by low temperature, providing a possible explanation for the numerous reported differences in the sex ratio between laboratory and different geographically located populations.
Effects of Pollens on Fecundity and Longevity of AdultScambus buolianae(Htg.) (Hymenoptera: Ichneumonidae)
Authors: Leius K.
Published: January 2010

Experiments indicated that pollen does not increase the length of life of the males ofScambus buolianae. Various pollens significantly increased either fecundity or longevity, or both, of the females. The greatest fecundity and longevity resulted from the addition of wild carrot and tulip pollen, Goldenrod, oriental poppy, or snapdragon pollen improved fecundity, while birch and ragweed pollen affected longevity only. Parasites have a greater chance of establishment in areas where they can find a rich vegetation of nectar- and pollen-producing plants, than in areas lacking such flowering plants.
Ambrosia Fungus Storage in Two Species of Gnathotrichus Eichhoff (Coleoptera: Scolytidae)
Authors: Farris S. H.
Published: January 2010

Stained serial sections of Gnathotrichus retusus (Lec.) and Gnathotrichus sulcatus (Lec.) males showed an enlargement of the forecoxal cavities to contain fungus cells. No similar enlargement or fungus material was found in these cavities of the females.
A New Pest of Apple in New Brunswick
Authors: Maxwell C. W. , Finnamore D. B.
Published: January 2010

In June, 1962, a type of bug injury was found by the junior author to be prevalent in a well cared for apple orchard of 800 trees at Debec, Carleton County, N.B. Adults of the bug causing the injury were collected in early July and determined by Dr. L. A. Kelton, Entomology Research Institute, Ottawa, as Lygidea mendax Reut., commonly known as the apple redbug. This is the first record of this species in New Brunswick.
Molluscs and Arthropods from Cardinal Nests at London, Ontario
Authors: Judd W. W.
Published: January 2010

During 1960, 534 organisms were collected from 32 nests. In order of decreasing numbers they were ants, bark lice, beetles, mites, sowbugs, springtails, spiders, snails, millipeds, harvestmen, hemipterous nymphs, biting midges, a slug, a damsel bug and a wasp. Observations on their distribution among the nests are included.
A Practical Apparatus for Feeding Artificial Diets to All Stages ofRhodnius prolixusStål
Authors: Friend W. G. , Cartwright Edna
Published: January 2010

Before atten~pting to determine the nutritional requirements ofRhodnius prelixusStål, a blood-feeding reduviid bug, it was necessary to build a feeding apparatus that would permit the insects to feed normally on various artificial diets. Since it was expected that large numbers of animals would have to be fed individually, practical considerations demanded that the feeding apparatus be easy to service and maintain. Some of the experimental diets would be extremely expensive and radioactive and consequently an apparatus that would permit the use of small volumes of diet was required.
Laboratory and Field Observations on Two Predators of the Pear Psylla in British Columbia
Authors: Watson T. K. , Wilde W. H. A.
Published: January 2010

During 1961 and 1962 observations were made on the activities of predators of the pear psylla, Psylla pyricola Förster, in the Okanagan Valley of British Columbia. Attacking the psylla together, the anthocorid bug, Anthocoris melanocerus Reuter, and the green lacewing, Chrysopa oculata Say, gave more effective suppression than either predator alone. DDT and Diazinon drastically reduced numbers of these predators b commercial plantings. In non-sprayed, isolated orchards, trace numbers of these predators maintained effective control of pear psylla populations.