Preliminary investigation into the effect of ethanol exposure on body temperature in Apis mellifera

Comparative studies of physiological effects of toxicants with social insects can be useful to understand effects in humans. These studies can yield insight into the biochemical mechanisms that underlie addictive behavior and other substance use. The aim of the current study is to assess the physiological influence of ethanol on body temperature change in Apis mellifera. It is part of a project to establish honey bees as a comparative model to humans for ethanol and other toxicant studies using social insects. Bees have shown a variety of responses to alcohol that make them viable research subjects, and are an easily obtainable and ethical alternative to humans in alcohol-behavior assays. Using an infrared laser thermometer, 125 harnessed bees (25 per condition) were measured at 30s intervals to record temperature change after exposure to either 0%, 1%, 2.5%, 5%, or 10% ethanol solution. The data collected in this experiment did not show significant variation between dose conditions. This experiment demonstrates a new protocol design and an apparatus that can be used for future study of ethanol's effect on honey bee physiology. More control, better instruments, and greater sample size may yield more insight into the viability and utility of honey bee body temperature as a measures for response to toxicants. The results of this experiment give necessary preliminary data to better study the body temperature effects of ethanol in honey bees

A native parasitic plant affects the performance of an introduced host regardless of environmental variation across field sites

Increasing evidence from glasshouse studies shows that native hemiparasitic plants can significantly impact the performance and growth of introduced host plants. We investigated the effect of the native Australian hemiparasite Cassytha pubescens R.Br. on the introduced shrub Ulex europaeus L. at three field sites in South Australia. Parasite infection significantly decreased midday PSII efficiency (ΦPSII) and the maximum electron transport rates (ETRmax) of U. europaeus across sites. The impact of C. pubescens on the photosynthetic performance of U. europaeus may have been caused by infected plants having significantly lower N and K, but higher Fe and Al than uninfected plants at all sites. Significant Al and Fe enrichment in infected plants may be possibly due to the parasite indirectly inducing rhizosphere acidification. At two sites, C. pubescens significantly affected host Fv/Fm, indicating chronic photoinhibition in response to infection. The impact of infection on Fv/Fmwas greatest at the wettest site, in line with an experiment where C. pubescens had more impact under high water availability. At this site, infected plants also had the highest foliar Fe and Al. The C isotope (δ13C) of infected plants was significantly lower than that of uninfected plants at only one site. Unusually, the δ13C of the parasite was the same as or significantly higher than that of the hosts. There were no site effects on parasite Fv/Fmor ΦPSII; however, ETRmaxand δ13C varied across sites. The results suggest that this native parasite has negative effects on U. europaeus in the field, as was found for glasshouse studies. The abundance of this introduced weed in Australia could be negatively affected by C. pubescens infection

Identificación, relevamiento e interpretación de áreas y sitios de valor paisajístico cultural en los centros urbanos tributarios de la cuenca del río Luján, Provincia de Buenos Aires. Estudio de caso: propuesta de área de protección paisajística cultural en el casco urbano de la ciudad de Luján

The aim of this research is to define areas of cultural scenic value from an interpretative synthesis that extends from a multi-scale vision of the cultural heritage to the heritage-architectural object as an inseparable component of the historical urban scene. Especially, the heritage situation in Luján City’s urban core, where the strong presence of the cultural and historical heritage associated with the river constitutes an area of unique characteristics, is analysed. In accordance with the goals of this research, the historical and geographic variables and spatiotemporal relations –as from the seventeenth century– in the subsequent urban development stages of the city have been studied, analysing the evolution of the urban fabric, as well as the main heritage landmarks characteristic of its scene. The periods for the analysis were organized in “time breaks” which illustrate the evolution of the area by the systematical analysis of each of the components that constitute the area of study, in particular, the landmarks and heritage areas representative of each identified stage. In order to accomplish the proposed goals, eleven areas with characteristics that deserve to be valued as historical urban scenes have been identified: Ana de Matos’s primitive estate; the Basilica area, El Quinto neighbourhood with the city’s cementery and the Colegio Hermanos Maristas, Parque Ameghino, the riverside area, Estación Basílica, Estación Luján, Avenida Humberto Primero, Parque San Martín, the water tank area, and Plaza Colón. Each of these areas is identified with different historical stages representative of the constitution of the city’s urban core. The most representative heritage landmarks of the urban core are closely related to the riverside park and are inseparably associated with the history of the settlement conformation in relation to the Rio Luján. However, the current Código de Ordenamiento Urbano [Urban Regulation Code] of the city establishes different categories of heritage protection fragmented in the area, and neither links both riverbanks and the different landmarks that define it, nor considers its protection from a scenic-environmental perspective, as a true and emblematic historical urban scene of great local and territorial value.Esta investigación propone la delimitación de áreas de “valor paisajístico cultural” a partir de una síntesis interpretativa que abarca desde una visión “multiescalar” del Patrimonio Cultural, hasta el objeto patrimonial-arquitectónico como componente indisoluble del paisaje urbano histórico. En particular se aborda la problemática patrimonial en el núcleo urbano de la ciudad de Luján, donde la fuerte presencia del Patrimonio Histórico Cultural asociado al río configura un enclave de características singulares. De acuerdo a los objetivos de la investigación, se han estudiado las variables histórico-geográficas y las relaciones espacio temporales (desde el s. XVII en adelante) en las sucesivas etapas del desarrollo urbano de la ciudad, analizando la evolución del tejido, así como los principales hitos patrimoniales que caracterizan su paisaje. El estudio por épocas se organizó mediante “cortes en el tiempo” que ilustran la evolución del enclave mediante el análisis sistemático de cada uno de los componentes que integran el área en cuestión, en particular los hitos y áreas patrimoniales representativas de cada etapa identificada. En cumplimiento de los objetivos propuestos, se han identificado once áreas con características que ameritan valorarse como paisaje urbano histórico: la primitiva estancia Ana de Matos; área Basilical; barrio El Quinto con cementerio municipal y colegio de Hnos. Maristas; Parque Ameghino; Área Costera; Estación Basílica; Estación Luján; Av. Humberto Primero; Parque San Martín; Tanque de agua; Plaza Colón. Cada una de estas áreas se identifica con diferentes etapas históricas representativas de la conformación del núcleo urbano de la ciudad. Los hitos patrimoniales más representativos que caracterizan al casco urbano se encuentran íntimamente relacionados con el parque costero y se asocian indisolublemente a la historia de la conformación del poblado en relación al Río Luján. Sin embargo, el Código de Ordenamiento Urbano vigente del Municipio, establece diferentes categorías de protección fragmentadas en el área, sin vincular ambas franjas costeras y los diferentes hitos que la jalonan, ni considerar su protección desde un enfoque paisajístico ambiental, como un verdadero paisaje urbano histórico emblemático de gran valor local y territorial

The impact of a native hemiparasite on a major invasive shrub is affected by host size at time of infection.

Few studies have examined how parasite impact is affected by host size. In a glasshouse experiment, we investigated the impact of the Australian native hemiparasitic vine, Cassytha pubescens, on a major invasive shrub, Ulex europaeus, of different sizes. Infected plants had significantly lower total, shoot and root biomass, but the parasite's impact was more severe on small than large hosts. When infected small but not large hosts had significantly lower nodule biomass. Irrespective of size, infection significantly decreased host shoot/root ratio, predawn and midday quantum yields, maximum electron transport rates and carbon isotope composition, and host nodule biomass g-1 root biomass significantly increased in response to infection. Infection did not affect host foliar nitrogen concentration or midday shoot water potential. Parasite biomass was significantly lower on small relative to large hosts, but was similar g-1 host total biomass. Parasite stem nitrogen, phosphorous and potassium concentration were significantly greater when C. pubescens was growing on small than large hosts. Our results clearly show that C. pubescens strongly decreases performance of this major invasive shrub, especially when hosts are small. This suggests that C. pubescens could be used most effectively as a native biocontrol when deployed on smaller hosts

Multipoverty in Venezuela

Poverty has been defined by several authors and international organizations from similar perspectives. However, those definitions tend to be simplistic and not powerful enough to deal with complex situations that involve different points of view on the poverty phenomenon. The aim of this paper is to use a praxeological standpoint and introduce a new definition, multipoverty, while using it to analyze the current crisis in Venezuela. Three main conclusions are drawn: in current Venezuela, all common people are very likely to be poor, and a social explosion there is possible; the nature of the human being is too complex to be analyzed under a simplistic approach based on the rigidness of pure quantitative methods; the multipoverty approach adds a humanistic, praxeological, and individualistic edge, based upon ideas of freedom of action, to the traditional definitions of poverty and helps to better understand the phenomena

High water availability increases the negative impact of a native hemiparasite on its non-native host

© 2015 The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. Environmental factors alter the impacts of parasitic plants on their hosts. However, there have been no controlled studies on how water availability modulates stem hemiparasites' effects on hosts. A glasshouse experiment was conducted to investigate the association between the Australian native stem hemiparasite Cassytha pubescens and the introduced host Ulex europaeus under high (HW) and low (LW) water supply. Cassytha pubescens had a significant, negative effect on the total biomass of U. europaeus, which was more severe in HW than LW. Regardless of watering treatment, infection significantly decreased shoot and root biomass, nodule biomass, nodule biomass per unit root biomass, F v/F m, and nitrogen concentration of U. europaeus. Host spine sodium concentration significantly increased in response to infection in LW but not HW conditions. Host water potential was significantly higher in HW than in LW, which may have allowed the parasite to maintain higher stomatal conductances in HW. In support of this, the δ13C of the parasite was significantly lower in HW than in LW (and significantly higher than the host). C. pubescens also had significantly higher F v/F m and 66% higher biomass per unit host in the HW compared with the LW treatment. The data suggest that the enhanced performance of C. pubescens in HW resulted in higher parasite growth rates and thus a larger demand for resources from the host, leading to poorer host performance in HW compared with LW. C. pubescens should more negatively affect U. europaeus growth under wet conditions rather than under dry conditions in the field

Differentiation of regulatory myeloid and T-cells from adult human hematopoietic stem cells after allogeneic stimulation

IntroductionDonor hematopoietic stem cell (DHSC) infusions are increasingly being studied in transplant patients for tolerance induction.MethodsTo analyze the fate of infused DHSCs in patients, we developed an in vitro culture system utilizing CD34+DHSCs stimulated with irradiated allogeneic cells in cytokine supplemented medium long-term.ResultsFlow cytometric analyses revealed loss of the CD34 marker and an increase in CD33+ myeloid and CD3+ T-cell proportion by 10.4% and 72.7%, respectively, after 21 days in culture. T-cells primarily expressed TcR-αβ and were of both CD4+ and CD8+ subsets. Approximately 80% of CD3+ T cells lacked expression of the co-stimulatory receptor CD28. The CD4+ compartment was predominated by CD4+CD25+CD127-FOXP3+ Tregs (>50% CD4+CD127- compartment) with <1% of all leukocytes exhibiting a CD4+CD127+ phenotype. Molecular analyses for T-cell receptor excision circles showed recent and increased numbers of TcR rearrangements in generated T cells over time suggesting de novo differentiation from DHSCs. CD33+ myeloid cells mostly expressed HLA-DR, but lacked expression of co-stimulatory receptors CD80 and CD83. When studied as modulators in primary mixed lymphocyte reactions where the cells used to stimulate the DHSC were used as responders, the DHSC-lines and their purified CD8+, CD4+, CD33+ and linage negative subsets inhibited the responses in a dose-dependent and non-specific fashion. The CD8+ cell-mediated inhibition was due to direct lysis of responder cells.DiscussionExtrapolation of these results into the clinical situation would suggest that DHSC infusions into transplant recipients may generate multiple subsets of donor “chimeric” cells and promote recipient Treg development that could regulate the anti-donor immune response in the periphery. These studies have also indicated that T cell maturation can occur in vitro in response to allogeneic stimulation without the pre-requisite of a thymic-like environment or NOTCH signaling stimulatory cell line

Does nitrogen affect the interaction between a native hemiparasite and its native or introduced leguminous hosts?

© 2016 The Authors. New Phytologist © 2016 New Phytologist Trust Associations between plants and nitrogen (N)-fixing rhizobia intensify with decreasing N supply and come at a carbon cost to the host. However, what additional impact parasitic plants have on their leguminous hosts’ carbon budget in terms of effects on host physiology and growth is unknown. Under glasshouse conditions, Ulex europaeus and Acacia paradoxa either uninfected or infected with the hemiparasite Cassytha pubescens were supplied (high nitrogen (HN)) or not (low nitrogen (LN)) with extra N. The photosynthetic performance and growth of the association were measured. Cassytha pubescens significantly reduced the maximum electron transport rates and total biomass of U. europaeus but not those of A. paradoxa, regardless of N. Infection significantly decreased the root biomass of A. paradoxa only at LN, while the significant negative effect of infection on roots of U. europaeus was less severe at LN. Infection had a significant negative impact on host nodule biomass. Ulex europaeus supported significantly greater parasite biomass (also per unit host biomass) than A. paradoxa, regardless of N. We concluded that rhizobia do not influence the effect of a native parasite on overall growth of leguminous hosts. Our results suggest that C. pubescens will have a strong impact on U. europaeus but not A. paradoxa, regardless of N in the field