Getting a Grip on the Adhesion Mechanism of Epiphytic Orchids – Evidence From Histology and Cryo-Scanning Electron Microscopy

Plants and animals evolve different attachment structures and strategies for reversible or permanent adhesion to different substrate types. For vascular epiphytes, having the ability to permanently attach to their host plants is essential for establishment and survival. Unlike mistletoe roots, roots of vascular epiphytes do not penetrate the host tissues but instead achieve attachment by growing in close contact to the surface of the substrate. However, the fundamental understanding of the attachment functions of epiphytic roots remains scarce, where majority of studies focused on the general root morphology, their functional properties and the descriptions of associated microbial endophytes. To date, research on attachment strategies in plants is almost entirely limited to climbers. Therefore, this study aims to fill the knowledge gap and elucidate the attachment functions of roots of epiphytic orchids. With the use of histology and high-resolution cryo-scanning electron microscopy (cryo-SEM) technique with freeze fracturing, the intimate root-bark substrate interface of epiphytic orchid Epidendrum nocturnum Jacq was investigated. Results showed a flattened underside of the root upon contact with the substrate surface, and the velamen layer appeared to behave like a soft foam, closely following the contours of the substrate. Root hairs emerged from the outermost velamen layer and entered into the crevices in the substrate, whenever possible

Holding on or falling off: The attachment mechanism of epiphytic Anthurium obtusum changes with substrate roughness

Premise For vascular epiphytes, secure attachment to their hosts is vital for survival. Yet studies detailing the adhesion mechanism of epiphytes to their substrate are scarce. Examination of the root hair-substrate interface is essential to understand the attachment mechanism of epiphytes to their substrate. This study also investigated how substrate microroughness relates to the root-substrate attachment strength and the underlying mechanism(s). Methods Seeds of Anthurium obtusum were germinated, and seedlings were transferred onto substrates made of epoxy resin with different defined roughness. After 2 months of growth, roots that adhered to the resin tiles were subjected to anchorage tests, and root hair morphology at different roughness levels was analyzed using light and cryo scanning electron microscopy. Results The highest maximum peeling force was recorded on the smooth surface (glass replica, 0 µm). Maximum peeling force was significantly higher on fine roughness (0, 0.3, 12 µm) than on coarse (162 µm). Root hair morphology varied according to the roughness of the substrate. On smoother surfaces, root hairs were flattened to achieve large surface contact with the substrate. Attachment was mainly by adhesion with the presence of a glue-like substance. On coarser surfaces, root hairs were tubular and conformed to spaces between the asperities on the surface. Attachment was mainly via mechanical interlocking of root hairs and substrate. Conclusions This study demonstrates for the first time that the attachment mechanism of epiphytes varies depending on substrate microtopography, which is important for understanding epiphyte attachment on natural substrates varying in roughness

The development of space-pointing device "Airtouch"

There are many pointing input device information into the computer, the most common of which are a computer mouse and the touchpad on a laptop. However, they have their drawbacks: we must keep in hand the mouse to use it. Touchpad also does have a limited scope. We offer take out touchpad beyond the classical touchpad device. To this end, we propose to use an accelerometer and a gyroscope, attached to the finger, and a microcontroller with a wireless communication module and power element on the wrist. For competitive devices with similar device should differ ease, accuracy, and be affordable

Biological variation in climbing aroids

Antecedentes y Objetivos: Las especies de Araceae son conocidas por sus distintas formas de vida; sin embargo, la terminología relacionada con este grupo genera confusiones conceptuales dentro de la comunidad científica. Nuestro objetivo fue demostrar la confusión conceptual actual derivada de la literatura y ejemplares de herbario vs. observaciones y datos de campo. Métodos: Se realizó una revisión exhaustiva de fuentes de información relevantes sobre las formas de vida de aráceas, incluyendo floras y tratamientos taxonómicos, así como de ejemplares de herbario. Adicionalmente, se llevó a cabo un censo de seis especies de aráceas en la Estación de Biología Tropical “Los Tuxtlas”, Veracruz, México. Para cada individuo se buscaron las conexiones de sus raíces adventicias y tallos con el suelo, además se tomaron medidas de su longitud total y hojas para crear tres clases ontogénicas. Resultados clave: Se presentan las descripciones de formas de vida de 30 especies de Araceae trepadoras de Veracruz publicadas en nueve publicaciones, mostrando una marcada inconsistencia en el uso de la terminología. El análisis de los datos documentados en los ejemplares de herbario reveló para 17 especies, que todas fueron asignadas con al menos tres de ocho diferentes categorías de hábito, principalmente como epífita, hemiepífita y trepadora. De las seis especies censadas en campo, la mayoría de los individuos tiene conexión con el suelo. Conclusiones: Las asignaciones de formas de vida basadas en observaciones de campo sin tener datos cuantitativos sobre el contacto de las plantas con el suelo son problemáticas. Más bien, es necesario analizar y aclarar la ontogenia de las aráceas trepadoras, lo que puede contribuir a estructurar adecuadamente nuestros conceptos y evitar ambigüedades en la terminología. Asimismo, también se debería evitar que se agrupen a las especies de Araceae indistintamente en estudios sobre epífitas, lo cual lleva a sobreestimar la riqueza reportada.Background and Aims: The species of Araceae are known for their diversity of life forms; however, the terminology regarding this group generates conceptual confusion within the scientific community. Our objective was to demonstrate the current conceptual confusion based on the literature, herbarium vouchers vs. observations and field data. Methods: A thorough review of relevant sources of information on aroid life forms was carried out, including floras and taxonomic treatments, as well as herbarium vouchers. Additionally, a census of six aroid species was conducted at the Tropical Biological Station “Los Tuxtlas”, Veracruz, Mexico. For each individual we searched for the connections of its adventitious roots and stems with the soil, in addition we took measurements of its total length and leaves to create three ontogenic classes. Key results: We present descriptions of life forms of 30 species of climbing Araceae from Veracruz published in nine publications, showing pronounced inconsistency in the use of terminology. The analysis of the data documented in the herbarium specimens revealed for 17 species, that these were assigned to at least three of eight different habit categories, mainly as epiphyte, hemiepiphyte and climber. Of the six species surveyed in the field, most of the individuals have a connection with the soil. Conclusions: Life form assignments based on field observations without quantitative data on the contact of plants with the soil are problematic. Rather, it is necessary to analyze and clarify the ontogeny of climbing aroids, which can help to properly structure our concepts and avoid ambiguities in terminology. Likewise, it should also be avoided that Araceae species are lumped indiscriminately in epiphyte studies, which leads to an overestimation of the reported richness

Environmental control of the microfaunal community structure in tropical bromeliads.

Ecological communities hosted within phytotelmata (plant compartments filled with water) provide an excellent opportunity to test ecological theory and to advance our understanding of how local and global environmental changes affect ecosystems. However, insights from bromeliad phytotelmata communities are currently limited by scarce accounts of microfauna assemblages, even though these assemblages are critical in transferring, recycling, and releasing nutrients in these model ecosystems. Here, we analyzed natural microfaunal communities in leaf compartments of 43 bromeliads to identify the key environmental filters underlying their community structures. We found that microfaunal community richness and abundance were negatively related to canopy openness and vertical height above the ground. These associations were primarily driven by the composition of amoebae and flagellate assemblages and indicate the importance of bottom-up control of microfauna in bromeliads. Taxonomic richness of all functional groups followed a unimodal relationship with water temperature, peaking at 23-25°C and declining below and above this relatively narrow thermal range. This suggests that relatively small changes in water temperature under expected future climate warming may alter taxonomic richness and ecological structure of these communities. Our findings improve the understanding of this unstudied but crucial component of bromeliad ecosystems and reveal important environmental filters that likely contribute to overall bromeliad community structure and function.This research was funded by Natural Sciences and Engineering Research Council of Canada (NSERC) and the Swiss National Science Foundation (SNF)

Varespladib and cardiovascular events in patients with an acute coronary syndrome: the VISTA-16 randomized clinical trial

IMPORTANCE: Secretory phospholipase A2(sPLA2) generates bioactive phospholipid products implicated in atherosclerosis. The sPLA2inhibitor varespladib has favorable effects on lipid and inflammatory markers; however, its effect on cardiovascular outcomes is unknown. OBJECTIVE: To determine the effects of sPLA2inhibition with varespladib on cardiovascular outcomes. DESIGN, SETTING, AND PARTICIPANTS: A double-blind, randomized, multicenter trial at 362 academic and community hospitals in Europe, Australia, New Zealand, India, and North America of 5145 patients randomized within 96 hours of presentation of an acute coronary syndrome (ACS) to either varespladib (n = 2572) or placebo (n = 2573) with enrollment between June 1, 2010, and March 7, 2012 (study termination on March 9, 2012). INTERVENTIONS: Participants were randomized to receive varespladib (500 mg) or placebo daily for 16 weeks, in addition to atorvastatin and other established therapies. MAIN OUTCOMES AND MEASURES: The primary efficacy measurewas a composite of cardiovascular mortality, nonfatal myocardial infarction (MI), nonfatal stroke, or unstable angina with evidence of ischemia requiring hospitalization at 16 weeks. Six-month survival status was also evaluated. RESULTS: At a prespecified interim analysis, including 212 primary end point events, the independent data and safety monitoring board recommended termination of the trial for futility and possible harm. The primary end point occurred in 136 patients (6.1%) treated with varespladib compared with 109 patients (5.1%) treated with placebo (hazard ratio [HR], 1.25; 95%CI, 0.97-1.61; log-rank P = .08). Varespladib was associated with a greater risk of MI (78 [3.4%] vs 47 [2.2%]; HR, 1.66; 95%CI, 1.16-2.39; log-rank P = .005). The composite secondary end point of cardiovascular mortality, MI, and stroke was observed in 107 patients (4.6%) in the varespladib group and 79 patients (3.8%) in the placebo group (HR, 1.36; 95% CI, 1.02-1.82; P = .04). CONCLUSIONS AND RELEVANCE: In patients with recent ACS, varespladib did not reduce the risk of recurrent cardiovascular events and significantly increased the risk of MI. The sPLA2inhibition with varespladib may be harmful and is not a useful strategy to reduce adverse cardiovascular outcomes after ACS. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01130246. Copyright 2014 American Medical Association. All rights reserved

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives