Button botany: plasmodesmata in vegetable ivory

The hard endosperm of species of the palm genus Phytelephas (elephant plant), known as vegetable ivory, was used in the manufacture of buttons in the nineteenth century, the early twentieth century, and again in more recent times. Here, we show that the pathways for intercellular communication, including the cytoplasm in opposite pits and the plasmodesmata that traverse the cell wall, can be visualized in century-old inexpensive buttons that are readily available in antique shops.     

Productivity and sustainability of a vegetable ivory palm (Phytelephas aequatorialis, arecaceae) under three management regimes in Northwestern Ecuador

This study examines the productivity, sustainability, and management of tagua nuts from the palm Phytelephas aequatorialis under three management regimes in northwestern Ecuador. Tagua nuts are used internationally as an ivory substitute and the palm fronds are used locally as roof thatch. Plots were established in a control site and in three local management regimes: pure tagua groves; stands with tagua and cacao in an agroforestry system; and tagua groves where the undergrowth is cleared and old fronds removed. Data were collected for one year and local extractors were interviewed about their tagua management. Palm demography indicates heavy management with few subadult individuals and many more adult females than males. Productivity analyses do not demonstrate the influence of any one environmental variable on leaf or infructescence productivity. The pure tagua grove is the management regime most conducive to tagua sustainability. The sustainability results are underscored by the extractive methodology, where local extractors maximize tagua collected while minimizing collection time. These results are incorporated into management recommendations to foster tagua extraction while ensuring its sustainability and future use.     

Plant breeding and the vegetable industry

Beginning in prehistoric times, man has continuously sought to obtain vegetables of progressively greater productivity and better conformity to his ever increasing requirements. Today’s breeders must use the most modern knowledge and devices in efforts to keep abreast of new demands that grow out of our fast moving, mechanized, industrialized ways of working and living. Varieties are being modified more successfully than ever before to meet changing requirements, but always something more is desired.     

Phages in the global fruit and vegetable industry

From recent articles, we have learned that phages can constitute a promising alternative in the food industry to eliminate bacterial pathogens from seedlings in greenhouse and field environments, as well as from fresh‐cut food products. The fruit and vegetable industry requires quite a different approach than the meat or dairy industry. Several factors can inhibit efficacy of phage treatment such as plant watering or washing ready‐to‐eat products (water may dilute therapeutic doses), UV irradiation or extensive spreading of phytopathogens by wind, insects or even humans. Spontaneously occurring anomalous weather conditions in different parts of the world also may have an enormous impact on phage persistence in cultivations and on yields. Despite that, some phage preparations are commercially available and, without doubt, are much safer than chemical treatments. Along with increasing worldwide fruit and vegetable consumption, plant diseases and human foodborne illnesses are becoming a serious economic problem, resulting in a focus on optimization of phage treatment.     

Demography of the vegetable ivory palm Phytelephas seemannii in Colombia, and the impact of seed harvesting

1. The demography of the vegetable ivory palm Phytelephas seemannii was studied on the Pacific coast of Colombia and a female-based matrix model was used to determine the proportion of seed that can be sustainably harvested from the population.
2. The density of the palm stands ranged from 240 to 420 adult palms ha⁻¹. The sex ratio was 1:1 and palms of both sexes produced leaves at the same rate. Seedlings produced 1·2 leaves per year on average, juveniles 1·8, and adults 6·1–7·4.
3. Adult females had fewer leaves than males (18·5 vs. 21·3 on average). Leaves of females lasted about 2·7 years in the crown, those of males about 3·2 years.
4. Stems creep on the ground, growing at the apex and often dying behind, the extant portion not always reflecting the palm's total age. The longest stem of a female palm in the study plots was 2·5 m, corresponding to an 'extant' age of 85 years; the longest stem recorded was that of a male (outside the plots) 10·5 m long, corresponding to an 'extant' age of 184 years. These figures reflect differences in growth habit, not in longevity.
5. Reproduction began at about 24 years, when the palm still lacked an above-ground stem.
6. The population growth rate λ was 1·059, and was most sensitive to changes in survival of juveniles and adults, and relatively insensitive to changes in fecundity and growth.
7. River channel migration is the most important cause of adult mortality. Phytelephas seemannii is apparently an efficient colonizer of the understorey in the late phases of riverine forest succession.
8. The population can tolerate a harvest intensity of 86% of all seeds before λ decreases to the equilibrium level of 1·00. Monitoring of the populations under intensive harvesting is required.     

The lichen genus Umbilicaria in Ecuador

Nine species of the saxicolous lichen genus Umbilicaria from Ecuador are reported and a key is provided: U. africana, U. aprina, U. cinereorufescens, U. decussata, U. dendrophora, U. haplocarpa, U. leprosa, U. nylanderiana and U. vellea. The species diversity of this genus on the equatorial high mountains of South America is low compared to North America and Eurasia, but similar to that found on high African peaks close to the equator. The species mostly belong to a high‐alpine element with worldwide distribution. Two species belong to an Andean endemic element, viz U. haplocarpa and U. leprosa. The low diversity and low percentage of endemism may reflect the fairly recent uplift of the Andes and the comparatively small geographic extent of the alpine Andean biota. The dense rainforests of Ecuador leave few suitable open rock habitats for the establishment of these light‐craving lichens below the tree‐line (4000–4200 m a.s.l.), and thus their equatorial habitat is almost exclusively restricted to the alpine zone between the tree‐line and the snow‐line (4700–4800 m a.s.l.). The equatorial species mainly reproduce asexually by thalloconidia, and the adaptive significance of this type of reproduction in high altitude habitats is discussed.     

The impact of utilization of palm products on the population structure of the vegetable ivory palm (Hyphaene petersiana,arecaceae) in North-Central Namibia

Indigenous trees fulfil many subsistence and economic needs in north-central Namibia.Hyphaene petersiana provides a range of products which contribute to most aspects of people’s livelihoods. Of particular importance is its income-generating capacity through the use of palm leaves for basket production and the sale of liquor distilled from the fruits. This study investigates the population structure ofHyphaene petersiana in two areas of different human and livestock densities. Data were recorded for height class distribution, basal diameter of mature, stemmed individuals and sex ratios. These parameters of population structure indicate a reduction in the recruitment of mature palms and an increase in single-stemmed, vegetatively reproduced palm suckers of the smallest size class (0.5 m). This trend is more pronounced in the site with greater human and livestock population densities. It appears to be related to high recorded levels of browsing by livestock of juvenile, unstemmed palms, despite the unpalatability of palm leaves. This acts to prevent recruitment into larger size classes and increase the compensatory growth of palm suckers, the latter being enhanced due to reduced competition through the prior removal by grazing animals of grasses and other herbaceous species. Accompanying this heavy pressure on juvenile palms are destructive uses of mature, stemmed palms, including their felling for construction purposes and tapping for palm wine. With regional human population increase, exacerbated by a recent trend to privatise land and raise pressure on remaining communal resources, it is possible that these destructive uses of mature palms will increase to unsustainable levels. Concern is thus expressed in this study regarding the long-term viability ofHyphaene petersiana populatiops in this area.     

The History of Entomology in Ecuador

This work is not intended to be a complete review of all publications about entomology in Ecuador. It compiles the history of entomology in Ecuador in a chronological order. It first provides observations about the influence of pre-Columbian cultures and the cultural heritage of indigenous populations. It then presents the contribution of the Spanish conquest and colonization chroniclers, the specialists that described American species during the Renaissance period and the great scientific expeditions. Finally the birth of Ecuadorian entomology as a science is described with the creation of institutes for applied research and the Ecuadorian museums of entomology.     

Surviving Shattered Worlds: Vietnam and Cambodia

Shattered World: Adaptation and Survival among Vietnam's Highland People during the Vietnam War . Gerald Cannon Hickey
Beyond the Killing Fields: Voices of Nine Cambodian Survivors in America . Usha Welaratna     

Gold in the ivory tower: equity rewards of outlicensing

An analysis of life-science initial public offerings from three time periods reveals that the equity share received by universities and their academic researchers has changed over time.     

Resurrection Plants: The Puzzle of Surviving Extreme Vegetative Desiccation

Tolerance to near complete desiccation of vegetative organs is a widespread capability in bryophytes and is also shared by a small group of vascular plants known as resurrection plants. To date more than 300 species, belonging to pteridophytes and angiosperms, have been identified that possess this kind of desiccation-tolerance. The vegetative desiccation-tolerance of resurrection plants is an inductive process displayed only under environmental stress with or without the involvement of abscisic acid as molecular signal. The different problems associated with desiccation encountered by resurrection plants render the employment of many interacting mechanisms necessary. Preservation of cell order and correct structure of membranes and macromolecules is underpinned by the synthesis of large amounts of sugars, amino acids, and small polypeptides such as late embryogenesis abundant (LEA) proteins and dehydrins. Some of these compatible solutes, such as sucrose and LEA proteins, are also involved in cytoplasm vitrification, which occurs during the last phase of desiccation. Mechanical damage due to vacuole shrinkage in dehydrating cells is avoided by cell wall folding or by replacing the water in vacuoles with nonaqueous substances. Oxidative stress, due to enhanced production of reactive oxygen species (ROS) especially by chloroplasts, is minimized through two different strategies. The homoiochlorophyllous resurrection plants, which conserve chloroplasts with chlorophylls and thylakoids upon drying, fold leaf blades and synthesize anthocyanins, as both sunscreens and free radical scavengers, and additionally increase the activity of antioxidant systems in cells. In contrast, the chloroplasts in poikilochlorophyllous species degrade chlorophylls and thylakoid membranes yielding desiccoplasts that are devoid of any internal structures. These adaptive mechanisms preserve cells from damage by desiccation and allow them to resume vital functions once rehydrated. Even if based mainly on cell protection during drying, the vegetative desiccation-tolerance of resurrection plants also relies on systems of cell recovery and repair upon rehydration. However, most of these systems are prepared during cell dehydration.     

Cryo-electron tomography: The challenge of doing structural biology in situ

The mitotic segregation apparatus composed of microtubules and chromatin functions to faithfully partition a duplicated genome into two daughter cells. Microtubules exert extensional pulling force on sister chromatids toward opposite poles, whereas pericentric chromatin resists with contractile springlike properties. Tension generated from these opposing forces silences the spindle checkpoint to ensure accurate chromosome segregation. It is unknown how the cell senses tension across multiple microtubule attachment sites, considering the stochastic dynamics of microtubule growth and shortening. In budding yeast, there is one microtubule attachment site per chromosome. By labeling several chromosomes, we find that pericentromeres display coordinated motion and stretching in metaphase. The pericentromeres of different chromosomes exhibit physical linkage dependent on centromere function and structural maintenance of chromosomes complexes. Coordinated motion is dependent on condensin and the kinesin motor Cin8, whereas coordinated stretching is dependent on pericentric cohesin and Cin8. Linking of pericentric chromatin through cohesin, condensin, and kinetochore microtubules functions to coordinate dynamics across multiple attachment sites.