Do market conditions affect preferences? Evidence from experimental markets with excess supply and excess demand

We study whether people's preferences in an unbalanced market are affected by whether they are on the excess supply side or the excess demand side of the market. Our analysis is based on the comparison of behavior between two types of experimental gift exchange markets, which vary only with respect to whether first or second movers are on the long side of the market. The direction of market imbalance could influence subjects' motivation, as second movers, workers, might react differently to favorable actions by first movers, firms, in the two cases. Our data show strong deviations from the standard game-theoretic prediction. However, we only find secondary treatment effects. First movers are not more generous when they are in excess supply and second movers do not respond less favorably when they are in excess demand. Competition has only minor psychological effects in our data.

Description of Photuris fulvipes (Blanchard) immatures (Coleoptera, Lampyridae, Photurinae) and bionomic aspects under laboratory conditions

Larvae and pupae of the cryptic firefly Photuris fulvipes (Blanchard,1837) are described. They were reared to adult stage from eggs laid by a female collected in São Luiz do Paraitinga, São Paulo, Brazil. Additionally, adult diagnosis and some bionomic data observed in the laboratory are presented. The bionomical and morphological characteristics of P. fulvipes were compared to other unidentified species of the genus and to Bycellonycha sp. from literature. At moment, the data are insufficient to propose a diagnosis for the species, but some characteristics appear to define species group or, at least, they may have generic value.

Endotoxin impairs cardiac hemodynamics by affecting loading conditions but not by reducing cardiac inotropism.

Acute myocardial dysfunction is a typical manifestation of septic shock. Experimentally, the administration of endotoxin [lipopolysacharride (LPS)] to laboratory animals is frequently used to study such dysfunction. However, a majority of studies used load-dependent indexes of cardiac function [including ejection fraction (EF) and maximal systolic pressure increment (dP/dt(max))], which do not directly explore cardiac inotropism. Therefore, we evaluated the direct effects of LPS on myocardial contractility, using left ventricular (LV) pressure-volume catheters in mice. Male BALB/c mice received an intraperitoneal injection of E. coli LPS (1, 5, 10, or 20 mg/kg). After 2, 6, or 20 h, cardiac function was analyzed in anesthetized, mechanically ventilated mice. All doses of LPS induced a significant drop in LV stroke volume and a trend toward reduced cardiac output after 6 h. Concomitantly, there was a significant decrease of LV preload (LV end-diastolic volume), with no apparent change in LV afterload (evaluated by effective arterial elastance and systemic vascular resistance). Load-dependent indexes of LV function were markedly reduced at 6 h, including EF, stroke work, and dP/dt(max). In contrast, there was no reduction of load-independent indexes of LV contractility, including end-systolic elastance (ejection phase measure of contractility) and the ratio dP/dt(max)/end-diastolic volume (isovolumic phase measure of contractility), the latter showing instead a significant increase after 6 h. All changes were transient, returning to baseline values after 20 h. Therefore, the alterations of cardiac function induced by LPS are entirely due to altered loading conditions, but not to reduced contractility, which may instead be slightly increased.

Contrôle biologique de la pourriture cendrée (Macrophomina phaseolina) du niébé par l’enrobage des semences avec Clonostachys rosea: Impact des conditions de conservation des semences traitées sur la performance du bioagent.

Dans les sols infestés avec Macrophomina phaseolina les semences de niébé ne germent pas ou bien la plantule est détruite plus ou moins rapidement après la germination. Clonostachys rosea est un champignon commun du sol reconnu comme un saprophyte avec une haute capacité de compétition sur les racines et dans le sol. Notre étude a pour objectif d’évaluer l’effet de C. rosea en traitement de semences du niébé conservées à 40°C sur le développement de la pourriture charbonneuse. L’effet de la durée de conservation sur la viabilité des spores et le pouvoir antagonique du bioagent a également été étudié dans les conditions semi contrôlé et au champ. Les isolats de C. rosea proviennent de la collection du laboratoire de phytopathologie de AGRHYMET. La production des spores a été effectuée sur le milieu PDA pendant 4 semaines. Les semences du niébé ont été traitées avec une suspension de spores à la concentration de 108 spores / ml à raison de 5 ml de suspension par kg de semences. Les semences traitées ont été séchées sous la hotte à flux laminaire pendant 2 h avant d’être semées ou conservées à 40°C. Des tests de viabilité des spores de C. rosea sur le milieu de culture PDA ont été effectués au laboratoire tous les 15 jours de conservation. Le taux de germination des semences sur papier buvard, évalué au cinquième jour après semis au laboratoire a été de 99 %. La forte moyenne de spores viables au jour de l’enrobage (J0) (>4,5 105), a chuté à 1700 spores par graines après 75 jours de conservation. En serre, le niveau de colonisation des tissus des plants de niébé se développant sur le sol infesté a été significativement plus faible chez les plants issus de graines enrobées (1009 microsclérotes/g tissus) que chez ceux issus de graines non enrobées (2356 microsclérotes/g tissus). Par rapport a la sévérité de la maladie, exprimée sur une échelle de 1-5, ont été notées une forte infection des plants du témoin Macrophomina (graines non traitées semées dans un sol infesté) et des attaques moins sévères sur les traitements G3M et G4M (graines traitées semées dans un sol infesté). Au champ dans l’essai semé avec des graines enrobées mais non conservées, l’association des isolats G3 et G4 a été nettement supérieure aux autres traitements par rapport aux rendements en fane et en graines. Par contre, par rapport au rendement, aucun effet des traitements n’a été observé dans l’essai semé avec les graines conservées pendant 30 jours.

Assessing an intuitive condition for stability under a range of traffic conditions via a generalised Lu-Kumar network

We argue the importance both of developing simple sufficientconditions for the stability of general multiclass queueing networks and also of assessing such conditions under a range of assumptions on the weight of the traffic flowing between service stations. To achieve the former, we review a peak-rate stability condition and extend its range of application and for the latter, we introduce a generalisation of the Lu-Kumar network on which the stability condition may be tested for a range of traffic configurations. The peak-rate condition is close to exact when the between-station traffic is light, but degrades as this traffic increases.

The influence of environmental conditions on immune responses, morphology and recapture probability of nestling house martins (Delichon urbica)

Nestling birds produced later in the season are hypothesized to be of poor quality with a low probability of survival and recruitment. In a Spanish population of house martins (Delichon urbica), we first compared reproductive success, immune responses and morphological traits between the first and the second broods. Second, we investigated the effects of an ectoparasite treatment and breeding date on the recapture rate the following year. Due probably to a reverse situation in weather conditions during the experiment, with more rain during rearing of the first brood, nestlings reared during the second brood were in better condition and had stronger immune responses compared with nestlings from the first brood. Contrary to other findings on house martins, we found a similar recapture rate for chicks reared during the first and the second brood. Furthermore, ectoparasitic house martin bugs had no significant effect on the recapture rate. Recaptured birds had similar morphology but higher immunoglobulin levels when nestlings compared with non-recaptured birds. This result implies that a measure of immune function is a better predictor of survival than body condition per se.

Development of the immature stages of Culex (Culex) saltanensis Dyar (Diptera, Culicidae) under laboratory conditions

Development of the immature stages of Culex (Culex) saltanensis Dyar (Diptera, Culicidae) under laboratory conditions. Culex (Culex) saltanensis Dyar, 1928 is becoming frequent and abundant in natural and artificial breeding sites in urban and rural areas of Brazil. This study contributes to the knowledge of the biology of a Brazilian strain of C. saltanensis. The development of specimens reared individually or grouped was observed. The study was conducted at a constant temperature of 27 ± 2°C, 14L:10D photoperiod and 80 ± 5% relative humidity. The immature stages were observed every 6 hours until adult emergence, which occurred in 12.29 days among individually reared specimens and in 13.12 days among group-reared specimens. Egg rafts for the experiment were obtained from the laboratory and field. Eggs hatched at a rate of 97.48 ± 2.32%. More eggs per egg raft were obtained from the field than from the laboratory. Males from individually reared specimens emerged in 12.29 ± 1.11 days and females in 13.12 ± 1.58 days. The male-female ratio was 1:1. Larval survival rate was higher than 85% for larvae reared isolated and higher than 95% for group-reared larvae. The Culex saltanensis life cycle was completed within 12 to 14 days, where larval instars I and IV took the most time to develop and the pupae, the shortest.

Interpretation of paleoceanographic conditions on the Peru shelf using paleoecology and geochemistry

Analisa una serie de sedimentos geoquimicos de nueve muestras colectadas a lo largo del recorrido de Panamá.

Phenology of Spalangia endius Walker (Hymenoptera, Pteromalidae) in pupae of Musca domestica Linnaeus (Diptera, Muscidae) under laboratory conditions

This work describes the phenology of Spalangia endius Walker in pupae of Musca domestica Linnaeus under laboratory conditions. In order to understand the developmental cycle of Spalangia endius under laboratory conditions, 360 Musca domestica pupae aged from 24 to 48 hours were exposed to 15 S. endius pairs for a period of 24 hours at 26 ± 2ºC. These pupae were kept in a BOD incubator at the same temperature, with a relative humidity of <70%, and 12 hours photophase. Fifteen hymenopteran specimens were dissected daily to evaluate their stage and development time. The phenology concluded that S. endius had a development cycle of 19 days with an incubation period of 24 hours. The development of the larvae of S. endius occurred in the subsequent eight days, during which a series of morphological alterations were observed. The pre-pupal stage occurred on the tenth day, where the movement ceased and elimination of the meconium started. The pupal stage occurred from the 11th to the 19th day, with emergence of males first, followed by female emergence approximately 24 hours later. These results allowed the evaluation of aspects of the detailed bionomics of the development of S. endius in order to record and program production of this parasitoid, thus optimizing its utilization as a biological control agent.

Comparative testing of a miniature diffusion size classifier to assess airborne ultrafine particles under field conditions

Miniature diffusion size classifiers (miniDiSC) are novel handheld devices to measure ultrafine particles (UFP). UFP have been linked to the development of cardiovascular and pulmonary diseases; thus, detection and quantification of these particles are important for evaluating their potential health hazards. As part of the UFP exposure assessments of highwaymaintenance workers in western Switzerland, we compared a miniDiSC with a portable condensation particle counter (P-TRAK). In addition, we performed stationary measurements with a miniDiSC and a scanning mobility particle sizer (SMPS) at a site immediately adjacent to a highway. Measurements with miniDiSC and P-TRAK correlated well (correlation of r = 0.84) but average particle numbers of the miniDiSC were 30%âeuro"60% higher. This difference was significantly increased for mean particle diameters below 40 nm. The correlation between theminiDiSC and the SMPSduring stationary measurements was very high (r = 0.98) although particle numbers from the miniDiSC were 30% lower. Differences between the three devices were attributed to the different cutoff diameters for detection. Correction for this size dependent effect led to very similar results across all counters.We did not observe any significant influence of other particle characteristics. Our results suggest that the miniDiSC provides accurate particle number concentrations and geometric mean diameters at traffic-influenced sites, making it a useful tool for personal exposure assessment in such settings.

Extra burden of psychosomatic complaints among adolescents suffering from chronic conditions.

OBJECTIVE:: To determine whether there are differences in health perception and health care use among adolescents with psychosomatic symptoms (PS), with chronic conditions (CCs), and with both conditions compared with healthy controls. METHODS:: By using the SMASH02 database, 4 groups were created: youths with PS but no CCs (N = 1010); youths with CCs but no PS (N = 497); youths with both psychosomatic symptoms and chronic conditions (PSCC, N = 213); and youths with neither PS nor CC (control, N = 5709). We used χ tests and analysis of variance to compare each variable between the 4 groups. In a second step, all health and health care use variables were included in a multinomial regression analysis controlling for significant (p < .05) background variables and using the control group as the reference. RESULTS:: Overall, PS and PSCC youths were significantly more likely to rate their health as poor, to be depressed, and to have consulted several times their primary health care provider or a mental health professional than their healthy peers. With the exception of being depressed, PSCC adolescents reported worse health perception and higher health care use than CC and PS. CONCLUSIONS:: Although PS youths do not define PS as a CC, it should be considered as one. Moreover, having PS represents an additional burden to chronically ill adolescents. Health professionals dealing with adolescents must be aware of the deleterious health effects that PS can have on adolescents and have this diagnosis in mind to better target the treatment and improve their management.

Bioactivity of the latex from Parahancornia amapa (Apocynaceae) on the development of Rhodnius nasutus (Hemiptera, Reduviidae, Triatominae) under laboratory conditions

Bioactivity of the latex from Parahancornia amapa (Apocynaceae) on the development of Rhodnius nasutus (Hemiptera, Reduviidae, Triatominae) under laboratory conditions. The aim of this study was to verify the effects of the methanolic fraction of the latex from Parahancornia amapa (Apocynaceae) (PALAM) on individuals of the species Rhodnius nasutus Stål (Hemiptera, Triatominae). Many of the insects treated with the substance presented deformities and these may interfere in the feeding and possibly hinder the reproductive capacity. They also presented significant mortality during the molt when compared to the control group, noting a gradual increase in mortality. The treated insects also presented delayed nymphal development (5th instar) and higher adult longevity.

Biological aspects of immature stage of Nyssomyia whitmani (Antunes and Coutinho) (Diptera, Psychodidae, Phlebotominae) in laboratory conditions

Nyssomyia whitmani (Antunes and Coutinho, 1939) has been considered as a complex of cryptic species, and some of the populations of this complex plays an important role in the transmission of Leishmania spp. in Brazil. The present study reports the biological aspects concerning the productivity out of eggs and the development time of the descendants of females obtained in Dourados municipality, Mato Grosso do Sul state. The females were captured with modified electric aspirators, fed in hamsters and further individualized in containers for breeding. At the insectary, temperature and relative humidity were maintained on average of 24.5 °C and 67.3%, respectively. From 944 females 3737 eggs were obtained, 748 (20.0%) evolved to the stage of larvae, and 93 (12.4%) of these reached adult stage. The life cycle lasted 80.6 days and the last larval instar was the longest. The use of a higher protein diet revealed a significant improvement in larval development.

Characterization of Human Late Outgrowth Endothelial Progenitor-Derived Cells under Various Flow Conditions.

Background: Endothelial progenitor-derived cells (EPC) are a cell therapy tool in peripheral arterial disease and for re-endothelialization of bypasses and stents. Objective: To assess EPC behavior under flow conditions normally found in vivo. Results: EPC were isolated from human cord blood, cultured on compliant tubes and exposed in an in vitro flow system mimicking hemodynamic environments normally found in medium and large arteries. EPC exposed for 24 h to unidirectional (0.3 ± 0.1 or 6 ± 3 dynes/cm(2)) shear stress oriented along flow direction, while those exposed to bidirectional shear stress (0.3 ± 3 dynes/cm(2)) or static conditions had random orientation. Under bidirectional flow, tissue factor (TF) activity and mRNA expression were significantly increased (2.5- and 7.0-fold) compared to static conditions. Under low shear unidirectional flow TF mRNA increased 4.9 ± 0.5-fold. Similar flow-induced increases were observed for TF in mature umbilical vein-derived endothelial cells. Expression of tissue-type plasminogen activator (t-PA), urokinase (u-PA) and monocyte chemotactic protein 1 (MCP1) were reduced by 40-60% in late outgrowth endothelial progenitor-derived cells (LO-EPC) exposed to any flow environment, while MCP1, but not t-PA or u-PA, was decreased in HUVEC. Conclusions: Flow, in particular bidirectional, modifies the hemostatic balance in LO-EPC with increased TF and decreased plasminogen activator expression.