Agonistic-like responses from the torus semicircularis dorsalis elicited by GABA A blockade in the weakly electric fish Gymnotus carapo

Findings by our group have shown that the dorsolateral telencephalon of Gymnotus carapo sends efferents to the mesencephalic torus semicircularis dorsalis (TSd) and that presumably this connection is involved in the changes in electric organ discharge (EOD) and in skeletomotor responses observed following microinjections of GABA A antagonist bicuculline into this telencephalic region. Other studies have implicated the TSd or its mammalian homologue, the inferior colliculus, in defensive responses. In the present study, we explore the possible involvement of the TSd and of the GABA-ergic system in the modulation of the electric and skeletomotor displays. For this purpose, different doses of bicuculline (0.98, 0.49, 0.245, and 0.015 mM) and muscimol (15.35 mM) were microinjected (0.1 µL) in the TSd of the awake G. carapo. Microinjection of bicuculline induced dose-dependent interruptions of EOD and increased skeletomotor activity resembling defense displays. The effects of the two highest doses showed maximum values at 5 min (4.3 ± 2.7 and 3.8 ± 2.0 Hz, P < 0.05) and persisted until 10 min (11 ± 5.7 and 8.7 ± 5.2 Hz, P < 0.05). Microinjections of muscimol were ineffective. During the interruptions of EOD, the novelty response (increased frequency in response to sensory novelties) induced by an electric stimulus delivered by a pair of electrodes placed in the water of the experimental cuvette was reduced or abolished. These data suggest that the GABA-ergic mechanisms of the TSd inhibit the neural substrate of the defense reaction at this midbrain level.

In vitro studies of multiwalled carbon nanotube/ultrahigh molecular weight polyethylene nanocomposites with osteoblast-like MG63 cells

Carbon nanotubes are highly versatile materials; new applications using them are continuously being developed. Special attention is being dedicated to the possible use of multiwalled carbon nanotubes in biomaterials contacting with bone. However, carbon nanotubes are also controversial in regards to effects exerted on living organisms. Carbon nanotubes can be used to improve the tribological properties of polymer/composite materials. Ultrahigh molecular weight polyethylene (UHMWPE) is a polymer widely used in orthopedic applications that imply wear and particle generation. We describe here the response of human osteoblast-like MG63 cells after 6 days of culture in contact with artificially generated particles from both UHMWPE polymer and multiwalled carbon nanotubes (MWCNT)/UHMWPE nanocomposites. This novel composite has superior wear behavior, having thus the potential to reduce the number of revision hip arthroplasty surgeries required by wear failure of acetabular cups and diminish particle-induced osteolysis. The results of an in vitro study of viability and proliferation and interleukin-6 (IL-6) production suggest good cytocompatibility, similar to that of conventional UHMWPE (WST-1 assay results are reported as percentage of control ± SD: UHMWPE = 96.19 ± 7.92, MWCNT/UHMWPE = 97.92 ± 8.29%; total protein: control = 139.73 ± 10.78, UHMWPE = 137.07 ± 6.17, MWCNT/UHMWPE = 163.29 ± 11.81 µg/mL; IL-6: control = 90.93 ± 10.30, UHMWPE = 92.52 ± 11.02, MWCNT/UHMWPE = 108.99 ± 9.90 pg/mL). Standard cell culture conditions were considered as control. These results, especially the absence of significant elevation in the osteolysis inductor IL-6 values, reinforce the potential of this superior wear-resistant composite for future orthopedic applications, when compared to traditional UHMWPE.

Postural balance in patients with social anxiety disorder

Body stability is controlled by the postural system and can be affected by fear and anxiety. Few studies have addressed freezing posture in psychiatric disorders. The purpose of the present study was to assess posturographic behavior in 30 patients with social anxiety disorder (SAD) and 35 without SAD during presentation of blocks of pictures with different valences. Neutral images consisted of objects taken from a catalog of pictures, negative images were mutilation pictures and anxiogenic images were related to situations regarding SAD fears. While participants were standing on a force platform, similar to a balance, displacement of the center of pressure in the mediolateral and anteroposterior directions was measured. We found that the SAD group exhibited a lower sway area and a lower velocity of sway throughout the experiment independent of the visual stimuli, in which the phobic pictures, a stimulus associated with a defense response, were unable to evoke a significantly more rigid posture than the others. We hypothesize that patients with SAD when entering in a situation of exposure, from the moment the pictures are presented, tend to move less than controls, remaining this way until the experiment ends. This discrete body manifestation can provide additional data to the characterization of SAD and its differentiation from other anxiety disorders, especially in situations regarding facing fear.

Involvement of midbrain tectum neurokinin-mediated mechanisms in fear and anxiety

Electrical stimulation of midbrain tectum structures, particularly the dorsal periaqueductal gray (dPAG) and inferior colliculus (IC), produces defensive responses, such as freezing and escape behavior. Freezing also ensues after termination of dPAG stimulation (post-stimulation freezing). These defensive reaction responses are critically mediated by γ-aminobutyric acid and 5-hydroxytryptamine mechanisms in the midbrain tectum. Neurokinins (NKs) also play a role in the mediation of dPAG stimulation-evoked fear, but how NK receptors are involved in the global processing and expression of fear at the level of the midbrain tectum is yet unclear. The present study investigated the role of NK-1 receptors in unconditioned defensive behavior induced by electrical stimulation of the dPAG and IC of male Wistar rats. Spantide (100 pmol/0.2 μL), a selective NK-1 antagonist, injected into these midbrain structures had anti-aversive effects on defensive responses and distress ultrasonic vocalizations induced by stimulation of the dPAG but not of the IC. Moreover, intra-dPAG injections of spantide did not influence post-stimulation freezing or alter exploratory behavior in rats subjected to the elevated plus maze. These results suggest that NK-1 receptors are mainly involved in the mediation of defensive behavior organized in the dPAG. Dorsal periaqueductal gray-evoked post-stimulation freezing was not affected by intra-dPAG injections of spantide, suggesting that NK-1-mediated mechanisms are only involved in the output mechanisms of defensive behavior and not involved in the processing of ascending aversive information from the dPAG.

An interleukin-33/ST2 signaling deficiency reduces overt pain-like behaviors in mice

Interleukin (IL)-33, the most recent member of the IL family of cytokines, signals through the ST2 receptor. IL-33/ST2 signaling mediates antigen challenge-induced mechanical hyperalgesia in the joints and cutaneous tissues of immunized mice. The present study asked whether IL-33/ST2 signaling is relevant to overt pain-like behaviors in mice. Acetic acid and phenyl-p-benzoquinone induced significant writhing responses in wild-type (WT) mice; this overt nociceptive behavior was reduced in ST2-deficient mice. In an antigen-challenge model, ST2-deficient immunized mice had reduced induced flinch and licking overt pain-like behaviors. In the formalin test, ST2-deficient mice also presented reduced flinch and licking responses, compared with WT mice. Naive WT and ST2-deficient mice presented similar responses in the rota-rod, hot plate, and electronic von Frey tests, indicating no impairment of motor function or alteration in basal nociceptive responses. The results demonstrate that IL-33/ST2 signaling is important in the development of overt pain-like behaviors.

Activation of locus coeruleus heme oxygenase-carbon monoxide pathway promoted an anxiolytic-like effect in rats

The heme oxygenase-carbon monoxide pathway has been shown to play an important role in many physiological processes and is capable of altering nociception modulation in the nervous system by stimulating soluble guanylate cyclase (sGC). In the central nervous system, the locus coeruleus (LC) is known to be a region that expresses the heme oxygenase enzyme (HO), which catalyzes the metabolism of heme to carbon monoxide (CO). Additionally, several lines of evidence have suggested that the LC can be involved in the modulation of emotional states such as fear and anxiety. The purpose of this investigation was to evaluate the activation of the heme oxygenase-carbon monoxide pathway in the LC in the modulation of anxiety by using the elevated plus maze test (EPM) and light-dark box test (LDB) in rats. Experiments were performed on adult male Wistar rats weighing 250-300 g (n=182). The results showed that the intra-LC microinjection of heme-lysinate (600 nmol), a substrate for the enzyme HO, increased the number of entries into the open arms and the percentage of time spent in open arms in the elevated plus maze test, indicating a decrease in anxiety. Additionally, in the LDB test, intra-LC administration of heme-lysinate promoted an increase on time spent in the light compartment of the box. The intracerebroventricular microinjection of guanylate cyclase, an sGC inhibitor followed by the intra-LC microinjection of the heme-lysinate blocked the anxiolytic-like reaction on the EPM test and LDB test. It can therefore be concluded that CO in the LC produced by the HO pathway and acting via cGMP plays an anxiolytic-like role in the LC of rats.

Hygroscopic behavior of buriti (Mauritia flexuosa) fruit

The objective of this study was to perform an analysis of the characterization of buriti fruit (Mauritia flexuosa). Each part of the fruit (peel, pulp, and fibrous part) was analyzed and their hygroscopic behavior was evaluated to establish the drying and storage conditions. Adsorption and desorption isotherms were obtained at 25 °C to the monolayer value was estimated, and the application of the Halsey, Handerson, Kuhn, Mizrahi, Oswin, Smith, BET, and GAB models was evaluated to the prediction of the isotherms. The fruit pulp was classified as rich in high quality oil, and like the peel and the fibrous part, it was also considered as rich in dietary fiber. The isotherms of the fruit parts were classified as type II, and their microbiological stability (a w < 0.6) can be maintained at 25 °C if the moisture content is lower than 8.5, 7.3, and 11.0 g H2O.100 g-1 of dry matter (d.m.), respectively. The hygroscopic behavior showed that in order to ensure stability, the fruit parts should be packaged with low water vapor permeability. The monolayer demonstrated that the peel, pulp, and the fibrous part cannot be dried under moisture content lower than 5.9, 5.0, and 6.4 g H2O.100 g-1 d.m., respectively. GAB was the most adequate model to describe their isotherms.

An investigation of the psychopathy construct and its (novel) correlates in non-clinical samples

A substantial research literature exists regarding the psychopathy construct in forensic populations, but more recently, the construct has been extended to non-clinical populations. The purpose of the present dissertation was to investigate the content and the correlates of the psychopathy construct, with a particular focus on addressing gaps and controversies in the literature. In Study 1, the role of low anxiety in psychopathy was investigated, as some authors have proposed that low anxiety is integral to the psychopathy construct. Participants (n = 346) responded to two self-report psychopathy scales, the SRP-III and the PPI-R, as well as measures of temperament, personality, and antisociality. Of particular interest was the PPI-R Stress Immunity sub scale, which represents low anxiety content. I t was found that Stress Immunity was not correlated with SRP-III psychopathy, nor did it share common personality or temperament correlates or contribute to the prediction of anti sociality. From Study 1, it was concluded that it was unlikely that low anxiety is a central feature of the psychopathy construct. In Study 2, the relationship between SRP-III psychopathy and Ability Emotional Intelligence (Le., Emotional Intelligence measured as an ability, rather than as a self-report personality trait-like characteristic) was investigated, to determine whether psychopathy is be s t seen as a syndrome characterized by emotional deficits or by the ability to skillfully manipulate and prey upon the others' emotions. A negative correlation between the two constructs was found, suggesting that psychopathy is best characterized by deficits in perceiving, facilitating, managing, and understanding emotions. In Study 3, sex differences in the sexual behavior (i.e., promiscuity, age of first sexual behaviors, extradyadic sexual relations) and appearance-related esteem (i.e., body shame,appearance anxiety, self-esteem) correlates of SRP-III psychopathy were investigated. The sexual behavior correlates of psychopathy were quite similar for men and women, but the esteem correlates were very different, such that high psychopathy in men was related to high esteem, whereas high psychopathy in women was generally related to low esteem. This sex difference was difficult to interpret in that it was not mediated by sexual behavior, suggesting that further exploration of this topic is warranted. Together, these three studies contribute to our understanding of non-clinical psychopathy, indicating that low anxiety is likely not part of the construct, that psychopathy is related to low levels of ability in Emotional Intelligence, and that psychopathy is an important predictor of behavior, ability, and beliefs and feelings about the self

"Weathering a hidden storm" : an application of Andersen's behavioral model of health, and health services use for those with diagnosable anxiety disorder

"Weathering a Hidden Storm": An App~ication of Andersen's Behaviora~ Mode~ of Hea~th, and Hea~th Services Use for Those With Diagnosab~e Anxiety Disorder Research has primarily focused on depression and mood disorders, but little research has been devoted to an examination of mental health services use amongst those with diagnosable anxiety disorder (Wittchen et al., 2002; Bergeron et al., 2005). This study examined the possible predicting factors for mental health services utilization amongst those with identifiable anxiety disorder in the Canadian population. The methods used for this study was the application of Andersen's Behavioral Model of Health Services Use, where predisposing, need and enabling 111 characteristics were regressed on the dependent variable of mental health services use. This study used the Canadian Community Health Survey (cycle 1.2: Mental Health and Well- Being) in a secondary data analysis. Several multiple logistics models predicted the likelihood to seek and use mental health services. Predisposing characteristics of gender and age, Enabling characteristics of education and geographical location, and those with co-occurring mood disorders were at the greatest increased likelihood to seek and use mental health services.

Buyer information and brand Choice behavior in markets with asymmetries

This thesis Entitled Buyer information and brand choice behaviour in markets with asymmetries.The period of transition set in by globalization and liberalization has ensued a onsiderable degree of homogeneity with western societies with respect to quantity and quality of goods and services.The study is aimed at finding out how the buyers adapt to the prevalent complex and dynamic market configuration by taking an archetypical situation of information gathering and brand- choice decision of select household consumer durables.The study was based on a set of 301 sample respondents who were either first time purchasers or repeat purchasers for household use, of the items under study in the sample area comprising of rural, urban and semi-urban areas. Data were collected using interview schedule and analysis of the same was done with standard statistical computer programs.Buyer confidence as perceived by buyers with respect to information acquisition and brand-choice represents the felt competence to effectively function in the market.In general, lower levels of education, income and occupation showed lower levels of search. The oldest were also low searchers. The repeat purchasers of the product searched less than the first purchasers. The most important source of information was word of mouth or information from others followed by television advertisements. The least important source of information was billboards, displays and similar forms of advertisements.The second factor is characterized by items representing ‘social attributes’ like, use by many others, use by peers, recommendation by significant others and reputation of the brand. The third factor represents ‘susceptibility to incentives and promotions’.

Real Estate Development In India And The Behavior of Investors to Invest In The Real Estate Market: An Empirical Investigation

This study examines the behavioral factors that influence the Indian Investors to invest in the Real Estate Market. Among the various factors that affect the tendency of investors to invest in the real market, certain factors are greatly influenced the investors at greatest extend while others at least level. From this study it is revealed that motivation from the real estate developers and brokers (mean value- 3.46) is most influencing factor and happening of uncertain events (mean value- 1.75) is the least factor that influences the investors’ investment behavior. In this study, the behavioral factor like over confidence and the hypotheses regarding education, religion were analyzed and found that religious factor influences the Indian investors to invest in the real estate

Behavior of geopolymer concrete exposed to elevated temperatures

The research in the area of geopolymer is gaining momentum during the past 20 years. Studies confirm that geopolymer concrete has good compressive strength, tensile strength, flexural strength, modulus of elasticity and durability. These properties are comparable with OPC concrete.There are many occasions where concrete is exposed to elevated temperatures like fire exposure from thermal processor, exposure from furnaces, nuclear exposure, etc.. In such cases, understanding of the behaviour of concrete and structural members exposed to elevated temperatures is vital. Even though many research reports are available about the behaviour of OPC concrete at elevated temperatures, there is limited information available about the behaviour of geopolymer concrete after exposure to elevated temperatures. A preliminary study was carried out for the selection of a mix proportion. The important variable considered in the present study include alkali/fly ash ratio, percentage of total aggregate content, fine aggregate to total aggregate ratio, molarity of sodium hydroxide, sodium silicate to sodium hydroxide ratio, curing temperature and curing period. Influence of different variables on engineering properties of geopolymer concrete was investigated. The study on interface shear strength of reinforced and unreinforced geopolymer concrete as well as OPC concrete was also carried out. Engineering properties of fly ash based geopolymer concrete after exposure to elevated temperatures (ambient to 800 °C) were studied and the corresponding results were compared with those of conventional concrete. Scanning Electron Microscope analysis, Fourier Transform Infrared analysis, X-ray powder Diffractometer analysis and Thermogravimetric analysis of geopolymer mortar or paste at ambient temperature and after exposure to elevated temperature were also carried out in the present research work. Experimental study was conducted on geopolymer concrete beams after exposure to elevated temperatures (ambient to 800 °C). Load deflection characteristics, ductility and moment-curvature behaviour of the geopolymer concrete beams after exposure to elevated temperatures were investigated. Based on the present study, major conclusions derived could be summarized as follows. There is a definite proportion for various ingredients to achieve maximum strength properties. Geopolymer concrete with total aggregate content of 70% by volume, ratio of fine aggregate to total aggregate of 0.35, NaOH molarity 10, Na2SiO3/NaOH ratio of 2.5 and alkali to fly ash ratio of 0.55 gave maximum compressive strength in the present study. An early strength development in geopolymer concrete could be achieved by the proper selection of curing temperature and the period of curing. With 24 hours of curing at 100 °C, 96.4% of the 28th day cube compressive strength could be achieved in 7 days in the present study. The interface shear strength of geopolymer concrete is lower to that of OPC concrete. Compared to OPC concrete, a reduction in the interface shear strength by 33% and 29% was observed for unreinforced and reinforced geopolymer specimens respectively. The interface shear strength of geopolymer concrete is lower than ordinary Portland cement concrete. The interface shear strength of geopolymer concrete can be approximately estimated as 50% of the value obtained based on the available equations for the calculation of interface shear strength of ordinary portland cement concrete (method used in Mattock and ACI). Fly ash based geopolymer concrete undergoes a high rate of strength loss (compressive strength, tensile strength and modulus of elasticity) during its early heating period (up to 200 °C) compared to OPC concrete. At a temperature exposure beyond 600 °C, the unreacted crystalline materials in geopolymer concrete get transformed into amorphous state and undergo polymerization. As a result, there is no further strength loss (compressive strength, tensile strength and modulus of elasticity) in geopolymer concrete, whereas, OPC concrete continues to lose its strength properties at a faster rate beyond a temperature exposure of 600 °C. At present no equation is available to predict the strength properties of geopolymer concrete after exposure to elevated temperatures. Based on the study carried out, new equations have been proposed to predict the residual strengths (cube compressive strength, split tensile strength and modulus of elasticity) of geopolymer concrete after exposure to elevated temperatures (upto 800 °C). These equations could be used for material modelling until better refined equations are available. Compared to OPC concrete, geopolymer concrete shows better resistance against surface cracking when exposed to elevated temperatures. In the present study, while OPC concrete started developing cracks at 400 °C, geopolymer concrete did not show any visible cracks up to 600 °C and developed only minor cracks at an exposure temperatureof 800 °C. Geopolymer concrete beams develop crack at an early load stages if they are exposed to elevated temperatures. Even though the material strength of the geopolymer concrete does not decrease beyond 600 °C, the flexural strength of corresponding beam reduces rapidly after 600 °C temperature exposure, primarily due to the rapid loss of the strength of steel. With increase in temperature, the curvature at yield point of geopolymer concrete beam increases and thereby the ductility reduces. In the present study, compared to the ductility at ambient temperature, the ductility of geopolymer concrete beams reduces by 63.8% at 800 °C temperature exposure. Appropriate equations have been proposed to predict the service load crack width of geopolymer concrete beam exposed to elevated temperatures. These equations could be used to limit the service load on geopolymer concrete beams exposed to elevated temperatures (up to 800 °C) for a predefined crack width (between 0.1mm and 0.3 mm) or vice versa. The moment-curvature relationship of geopolymer concrete beams at ambient temperature is similar to that of RCC beams and this could be predicted using strain compatibility approach Once exposed to an elevated temperature, the strain compatibility approach underestimates the curvature of geopolymer concrete beams between the first cracking and yielding point.

La organización: una aproximación desde la psicología positiva

Actualmente los problemas psicológicos como el estrés y la depresión se hacen más evidentes en las compañías debido tanto a factores económicos externos, como las crisis y el desempleo, e internos como tiempos de entrega, presión y, tensión por ventas, etc. Dichos problemas psicológicos afectan tanto al individuo (agotamiento físico y mental, fatiga constante, angustia, bajo estado de ánimo, fallas en la memoria) como a la misma organización (bajos rendimientos y baja productividad). La Psicología Positiva fue definida por Seligman (2000), como una aproximación que busca el bienestar personal a través de la potenciación de emociones positivas como la esperanza, la resiliencia y el optimismo. Este documento presenta una revisión sobre como se ha aplicado la Psicología Positiva al ámbito organizacional, concretamente en relación con el liderazgo, el clima organizacional y los equipos de trabajo

Nongenetic inheritance, linguistic competence, prenatal experience and behavior manipulation: recent contributions from behavioral neurobiology and neuropsychology to the explanation of behavior

This article gives an overview of presuppositions and explanations posed by behaviorist psychology (particularly its radical branch), cognitive–nativist sciences (i.e. psycholinguistics and a branch of cognitive psychology) and other disciplines regarding important psychological events such as anxiety, stress, fear, mood states and language. In relation to the discussion of environment versus genetics, contributions from behavioral neurobiology and neuropsychology are added, showing evidence of traits that can be multigenerationally inherited in a non-genetic way, which have an impact thought the life of organisms and on their way of interacting with the environment; ways in which behavior can be altered by recently unsuspected environmental agents or events, and the overlooked role of prenatal experiences in the explanation of behavior. The evidence calls into question presuppositions made by the academic disciplines listed above, and suggests alternative behavior reinterpretations and explanations

Attention and selection behavior on ‘universal search’ result pages

The ISO norm line 9241 states some criteria for ergonomics of human system interaction. In markets with a huge variety of offers and little possibility of differentiation, providers can gain a decisive competitive advantage by user oriented interfaces. A precondition for this is that relevant information can be obtained for entrepreneurial decisions in this regard. To test how users of universal search result pages use those pages and pay attention to different elements, an eye tracking experiment with a mixed design has been developed. Twenty subjects were confronted with search engine result pages (SERPs) and were instructed to make a decision while conditions “national vs. international city” and “with vs. without miniaturized Google map” were used. Different parameters like fixation count, duration and time to first fixation were computed from the eye tracking raw data and supplemented by click rate data as well as data from questionnaires. Results of this pilot study revealed some remarkable facts like a vampire effect on miniaturized Google maps. Furthermore, Google maps did not shorten the process of decision making, Google ads were not fixated, visual attention on SERPs was influenced by position of the elements on the SERP and by the users’ familiarity with the search target. These results support the theory of Amount of Invested Mental Effort (AIME) and give providers empirical evidence to take users’ expectations into account. Furthermore, the results indicated that the task oriented goal mode of participants was a moderator for the attention spent on ads. Most important, SERPs with images attracted the viewers’ attention much longer than those without images. This unique selling proposition may lead to a distortion of competition on markets.