Trabecular Bone Structure Correlates with Hand Posture and Use in Hominoids

Bone is capable of adapting during life in response to stress. Therefore, variation in locomotor and manipulative behaviours across extant hominoids may be reflected in differences in trabecular bone structure. The hand is a promising region for trabecular analysis, as it is the direct contact between the individual and the environment and joint positions at peak loading vary amongst extant hominoids. Building upon traditional volume of interest-based analyses, we apply a whole-epiphysis analytical approach using high-resolution microtomographic scans of the hominoid third metacarpal to investigate whether trabecular structure reflects differences in hand posture and loading in knuckle-walking (Gorilla, Pan), suspensory (Pongo, Hylobates and Symphalangus) and manipulative (Homo) taxa. Additionally, a comparative phylogenetic method was used to analyse rates of evolutionary changes in trabecular parameters. Results demonstrate that trabecular bone volume distribution and regions of greatest stiffness (i.e., Young''s modulus) correspond with predicted loading of the hand in each behavioural category. In suspensory and manipulative taxa, regions of high bone volume and greatest stiffness are concentrated on the palmar or distopalmar regions of the metacarpal head, whereas knuckle-walking taxa show greater bone volume and stiffness throughout the head, and particularly in the dorsal region; patterns that correspond with the highest predicted joint reaction forces. Trabecular structure in knuckle-walking taxa is characterised by high bone volume fraction and a high degree of anisotropy in contrast to the suspensory brachiators. Humans, in which the hand is used primarily for manipulation, have a low bone volume fraction and a variable degree of anisotropy. Finally, when trabecular parameters are mapped onto a molecular-based phylogeny, we show that the rates of change in trabecular structure vary across the hominoid clade. Our results support a link between inferred behaviour and trabecular structure in extant hominoids that can be informative for reconstructing behaviour in fossil primates.     

Optimizing ecosystem function by manipulating pasture community composition

The ability to design plant communities to optimize particular ecosystem functions and thus more effectively provide ecosystem services would improve all types of ecosystem management, including agriculture. We propose a novel quantitative multi-step method for selecting mixtures of plant species to meet ecosystem objectives: collecting trait data; identifying suites of traits related to relevant community processes; relating those processes to the ecosystem functions of interest; optimizing the planted mixture; and evaluating trade-offs. This approach was tested using planted mixtures of 14 grassland species common in managed pastures of the northeastern United States. Ordination of trait data from greenhouse and small plot studies was used to relate species traits to community processes, followed by generalized additive modeling to relate community-weighted mean process scores to field estimates of biomass production and resistance to invasion. Multi-criteria optimization identified seed mixtures that maximized or minimized selected ecosystem functions, facilitating quantification of trade-offs in processual ability within species and between ecosystem functions at the community level. In this study, predicted seasonal and annual biomass values were within expected ranges, but the optimal mixtures differed from forage mixtures traditionally planted in the northeastern United States. Perennial ryegrass was the most commonly-selected grass. Legumes were represented less than expected, possibly due to attributes such as longevity and forage quality that are important in pastures but were not directly included in the optimization. Ecosystem function was not linearly related to species richness. While further research on quantitatively relating species traits and community processes is needed, multi-criteria optimization offers a new path for linking ecosystem function to ecosystem management.     

Generating thermotolerant colonies by pairing Beauveria bassiana isolates

Low thermotolerance in entomopathogenic fungi is the main impediment to their industrialization. This research, for the first time, describes the generation of a thermotolerant colony by pairing and subculturing (cycling) two Beauveria bassiana isolates without sexual reproduction. A mixture of B.?bassiana ERL1578 and ERL1576 was inoculated on quarter-strength Sabouraud dextrose agar with yeast extract (?SDAY). The paired culture (ERL1578?+?1576) was cycled three times to increase the frequency of possible hyphal fusion at the first cycle (c.?5/5?×?10(5) conidia), followed by a heat treatment as a selection pressure. Two non-paired isolates served as controls. Two morphologically different colonies (BbHet1 and BbHet2) were isolated from the pairing. BbHet1 colony had the highest conidial yield. BbHet2 had the most rapid mycelial growth and produced sponge-like mycelial masses (the others were flat), and its conidia were darker than the non-paired colonies under a microscope (400×). BbHet2 conidia had 60.7% germination after exposure to 45?°C for 60?min (the others had 相似文献   

Production of thermotolerant entomopathogenic fungal conidia on millet grain

Thermotolerance of entomopathogenic (insect-killing) fungi should be seriously considered before industrialization. This work describes the feasibility of millet grain as a substrate for production of thermotolerant Beauveria bassiana (Bb) GHA and ERL1170 and Metarhizium anisopliae (Ma) ERL1171 and ERL1540 conidia. First, conidial suspensions of the Bb isolates, produced on millet grain in polyethylene bags, were exposed to five temperatures (43–47°C) at 15-min intervals for up to 120 min (experiment I). Agar-based quarter-strength (¼) Sabouraud dextrose agar supplemented with yeast extract (SDAY) and whey permeate media served as controls. Millet-grain-based culture was superior in producing the most thermotolerant Bb conidia, followed by whey permeate agar and ¼SDAY-based cultures. Secondly, to compare the thermotolerance of conidia produced at the same conditions, the Bb isolates were then produced on agar-based millet powder medium, with ¼SDAY and whey permeate agar media as controls, and the two Ma isolates were added (experiment II). They were then exposed to the same temperatures as above. More thermotolerant Bb and Ma conidia were produced on millet powder agar than on whey permeate agar and ¼SDAY overall. These results suggest that millet grain can be used as a substrate to produce thermotolerant conidia in a mass production system.     

Role of epigenetics in developmental biology and transgenerational inheritance

The molecular mechanisms involved in developmental biology and cellular differentiation have traditionally been considered to be primarily genetic. Environmental factors that influence early life critical windows of development generally do not have the capacity to modify genome sequence, nor promote permanent genetic modifications. Epigenetics provides a molecular mechanism for environment to influence development, program cellular differentiation, and alter the genetic regulation of development. The current review discusses how epigenetics can cooperate with genetics to regulate development and allow for greater plasticity in response to environmental influences. This impacts area such as cellular differentiation, tissue development, environmental induced disease etiology, epigenetic transgenerational inheritance, and the general systems biology of organisms and evolution.     

Restoring species diversity: assessing capacity in the U.S. native plant industry

Large quantities of diverse and appropriately adapted native plant germplasm are required to facilitate restoration globally, yet shortages can prevent restorations from attaining desired species diversity and structure. An extensive native plant industry has developed in the United States to help meet these demands, yet very little is known about its capacity to support germplasm needs. To better understand current capacity and germplasm availability, we report results of the first comprehensive and quantitative assessment of the native plant industry in the United States, which includes at least 841 vendors nationwide and the species they make available for restoration. We synthesized lists of commercially available species from native plant vendors across the United States and identified gaps in species availability to inform germplasm research, development, and production. Of the approximately 25,000 vascular plant taxa native to the United States, 26% are sold commercially, with growth form, conservation status, distribution, and taxonomy significantly predicting availability. In contrast, only 0.07% of approximately 3,000 native nonvascular taxa are sold commercially. We also investigated how demand for germplasm to support high‐quality restoration efforts is met by vendors in the Midwestern tallgrass prairie region, which has been targeted extensively by restoration efforts for decades. In this well‐developed native plant market, 74% of more than 1,000 target species are commercially available, often from vendors that advertise genetically diverse, locally sourced germplasm. We make recommendations to build on the successes of regional markets like the tallgrass prairie region, and to fill identified gaps, including investing in research to support production, ensuring more consistent and clear demand, and fostering regional collaboration.     

A Forward Genetic Screen in Zebrafish Identifies the G-Protein-Coupled Receptor CaSR as a Modulator of Sensorimotor Decision Making

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