nils-herrmann/clean_scirepeval huggingface dataset:
The aerodynamics of wind pollination
Venue: Botanical Review

A number of morphologic features have evolved in evolutionarily divergent plant groups that appear to increase the efficiency of wind pollination. Among these features are the appearance of low density pollen grains, female ovulate organs that direct air currents carrying pollen toward stigmas or micropyles, and population structures with a high density of con-specifics. This paper reviews the aerodynamic theory, and the experimental and field data that are relevant to an understanding of the adaptive significance of these and other features of anemophily. Emphasis is placed on the mathematical description of the behavior of airflow patterns around ovulate organs. The efficiency of wind pollination is shown to be dictated principally by the vectoral properties of air currents created by and around ovulate organs and the physical properties of pollen that dictate their behavior as airborne particles.AbstraktEine Anzahl von morphologischen Kennzeichen, die Effizienz der Windpollination zu steigern scheinen, haben sich in evolutionär ausenandergehonden Pflanzengruppen entwickelt. Zu diesen Kennzeichen gehören die Erscheinung von Pollenkörnen von geringer Dichte, weiblichen Organen die pollentragende Luftströmungen zu den Stigmas oder Micropylen dirigieren, und Bevölkerungsstrukturen mit grosser Dichte von Con-specifics. Diese Abhandlung gibt einen überblick der aerodynamischen Theorie und der experimentelle Werte, die für das Verständnis der adaptiven Signifikanz dieser und anderer Kennzeichen der Windpollination von Bedeutung sind. Betont wird die mathematische Beschreibung des Verhaltens der Luftströmungen um die weiblichen Organe. Es wird gezeigt, dass die Effizienz der Windpollination hauptsächlich durch die vectoralen Eigenschaften der Luftströmungen die durch und um die weiblichen Organe entstehen, bestimmt wird, und durch die physischen Eigenschaften des Pollens, die sein Verhalten als luftgetragene Partikel diktieren.
Tissue and life‐stage distribution of a defensin gene in the Lone Star tick, Amblyomma americanum
Venue: Medical and Veterinary Entomology

The transcript sequence of the Amblyomma americanum Linnaeus (Acari: Ixodidae) defensin, termed amercin (amn), was ascertained and a 219‐bp amn coding region identified. The gene encodes a 72‐amino acid prepropeptide with a putative 37‐amino acid mature peptide. This gene shows little similarity to either of the defensins from Amblyomma hebraeum Koch, the only other Amblyomma species for which a defensin has been described. Sequence comparisons with other tick defensins reveal amn to be shorter (6 bp or 2 amino acids) than the Ixodes scapularis Linnaeus (Acari: Ixodidae) and Dermacentor variabilis (Say) (Acari: Ixodidae) defensin sequences. The amercin prepropeptide has 60.8% and 59.5% similarity with the I. scapularis and D. variabilis prepropeptides, respectively, whereas the mature amercin peptide has 73.7% and 71.1% similarity with the mature peptides of these ticks. Similarity with other tick defensins ranges from 42% to 71%. In A. americanum, defensin transcript was found in the midgut, fat body and salivary gland tissues, as well as in the haemocytes. Defensin transcript was also present in early‐stage eggs (less than 48 h old), late‐stage eggs (approximately 2 weeks old), larvae and nymphs of A. americanum and I. scapularis, both of which are vector‐competent for Borrelia spirochetes.
Arbuscular mycorrhizal fungi in alleviation of salt stress: a review.
Venue: Annals of Botany

Salt stress has become a major threat to plant growth and productivity. Arbuscular mycorrhizal fungi colonize plant root systems and modulate plant growth in various ways.



This review addresses the significance of arbuscular mycorrhiza in alleviation of salt stress and their beneficial effects on plant growth and productivity. It also focuses on recent progress in unravelling biochemical, physiological and molecular mechanisms in mycorrhizal plants to alleviate salt stress.



The role of arbuscular mycorrhizal fungi in alleviating salt stress is well documented. This paper reviews the mechanisms arbuscular mycorrhizal fungi employ to enhance the salt tolerance of host plants such as enhanced nutrient acquisition (P, N, Mg and Ca), maintenance of the K(+) : Na(+) ratio, biochemical changes (accumulation of proline, betaines, polyamines, carbohydrates and antioxidants), physiological changes (photosynthetic efficiency, relative permeability, water status, abscissic acid accumulation, nodulation and nitrogen fixation), molecular changes (the expression of genes: PIP, Na(+)/H(+) antiporters, Lsnced, Lslea and LsP5CS) and ultra-structural changes. Theis review identifies certain lesser explored areas such as molecular and ultra-structural changes where further research is needed for better understanding of symbiosis with reference to salt stress for optimum usage of this technology in the field on a large scale. This review paper gives useful benchmark information for the development and prioritization of future research programmes.
New insights into the huddling dynamics of emperor penguins
Venue: Animal Behaviour

Social thermoregulation is a cooperative strategy in which animals actively aggregate to benefit from the warmth of conspecifics in response to low ambient temperatures. Emperor penguins, Aptenodytes forsteri , use this behaviour to ensure their survival and reproduction during the Antarctic winter. An emperor penguin colony consists of a dynamic mosaic of compact zones, the so-called huddles, included in a looser network of individuals. To maximize energy savings, birds should adjust their huddling behaviour according to environmental conditions. Here, we examined the dynamics of emperor penguin aggregations, based on photo and video records, in relation to climatic factors. Environmental temperature, wind and solar radiation were the main factors contributing to huddle formation. The analysis of individual movements showed that birds originating from loose aggregations continually joined huddles. Sometimes, a small number of birds induced a movement that propagated to the entire huddle, causing its breakup within 2 min and releasing birds, which then integrated into looser aggregations. Different parts of the colony therefore appeared to continually exchange individuals in response to environmental conditions. A likely explanation is that individuals in need of warmth join huddles, whereas individuals seeking to dissipate heat break huddles apart. The regular growth and decay of huddles operates as pulses through which birds gain, conserve or lose heat. Originally proposed to account for reducing energy expenditure, the concept of social thermoregulation appears to cover a highly dynamic phenomenon that fulfils a genuine regulatory function in emperor penguins.
Towards ultrahydrophobic surfaces : a biomimetic approach
Venue: Journal of Physics: Condensed Matter

We report on efforts to mimic the wetting behaviour of surfaces or leaves of certain plants, which are rendered ultrahydrophobic through a dense layer of hairs grown on top of the leaf. We use a simple moulding approach to obtain elastic hydrophilic hydrogel networks with pillar structures that may serve as model systems for such hairy surfaces. In order to generate such structures, we first generate either a steel master or directly use a lady's mantle leaf. Second, the master is moulded against a silicone to yield an elastomer, which is a negative of the hairy surface. A subsequent radical polymerization in the negative leads to the formation of an elastic hydrogel even for the very high aspect ratios characteristic of the natural system. The results of some preliminary contact angle measurements on the obtained structures are discussed.
Bill sweeping in spoonbills Platalea: no evidence for an effective suction force at the tip
Venue: Journal of Avian Biology

We analysed the hypothesis of Weihs and Katzir (1994) that feeding spoonbills use their broad bills by sweeping it through the water to shed a vortex. This would result in a hydrodynamic suction on the bottom for catching prey immediately or during the next sweep besides providing some extra benefits. The basic assumptions appear to be erroneous. (1) A spoonbill does not mainly feed on small, benthic invertebrates, but mainly on nekton such as fish and shrimps. (2) The inner surface of the upper mandible of a spoonbill is not concave but convex. (3) During feeding, a spoonbill does not keep its bill tip close to the bottom independent of the water depth. The outcomes of the tests supporting the hypothesis do not hold and the suggested benefits are dubious. Therefore, we reject the hypothesis and the claim that the bill of a spoonbill is used as a hydrofoil. The discussed paper tried to give an explanation of the behaviour of a bird with the help of hydrodynamic formulae. The fundamental mistake in the paper is that the use of the formulae is based on wrong assumptions concerning the food of the bird, its feeding behaviour as well as its anatomical details. The tests with a bird kept in captivity suggesting a proof of the rightness of the hypothesis lack a proper connection to the situation in the wild. Spoonbills ( Threskiornithidae, genus Platalea) are large wading birds characterised by their extremely flattened bills that are widened in the distal parts. The six species are very similar in shape and behaviour, mainly differing in size, colour of legs, bills and other bare parts, and in distribution (Matheu and del Hoyo 1992). They feed tactilely by walking in shallow
Total Internal Reflection Accounts for the Bright Color of the Saharan Silver Ant
Venue: PLOS ONE

The Saharan silver ant Cataglyphis bombycina is one of the terrestrial living organisms best adapted to tolerate high temperatures. It has recently been shown that the hairs covering the ant’s dorsal body part are responsible for its silvery appearance. The hairs have a triangular cross-section with two corrugated surfaces allowing a high optical reflection in the visible and near-infrared (NIR) range of the spectrum while maximizing heat emissivity in the mid-infrared (MIR). Those two effects account for remarkable thermoregulatory properties, enabling the ant to maintain a lower thermal steady state and to cope with the high temperature of its natural habitat. In this paper, we further investigate how geometrical optical and high reflection properties account for the bright silver color of C. bombycina. Using optical ray-tracing models and attenuated total reflection (ATR) experiments, we show that, for a large range of incidence angles, total internal reflection (TIR) conditions are satisfied on the basal face of each hair for light entering and exiting through its upper faces. The reflection properties of the hairs are further enhanced by the presence of the corrugated surface, giving them an almost total specular reflectance for most incidence angles. We also show that hairs provide an almost 10-fold increase in light reflection, and we confirm experimentally that they are responsible for a lower internal body temperature under incident sunlight. Overall, this study improves our understanding of the optical mechanisms responsible for the silver color of C. bombycina and the remarkable thermoregulatory properties of the hair coat covering the ant’s body.
Factors Affecting the Geometry of Silver Nanoparticles Synthesis in Chrysosporium Tropicum and Fusarium Oxysporum
Venue: Current Research in Nanotechnology

Biosynthesis of nanoparticles using fungal cells is a novel approach to develop biotechnological possess such as bioleaching and bioremediation. In the present study, an effort was made to investigate the effect of physio-chemical parameters on the silver nanoparticle formation with the fungus Chrysosporium tropicum Carmichael and Fusarium oxysporum Schltdl.  The possibilities to manipulating the geometry of silver nanoparticles by altering the key growth parameters such as pH, temperature, concentrations and time have been explored. The effect of AgNO3 with the cell free extract of fungi and time, temperature, pH with the formation of silver has also been investigated. The presence of nanosilver has been carried out with the Micro-scan reader and has been confirmed by X-Rays Diffractometer (XRD). The micrographs of the silver nanoparticles have been evaluated through the Transmission Electron Microscope (TEM) and confirmed by Scanning Electron Microscope (SEM). The effect of concentrations with response to time, temperature and pH has studied with the help of Micro-scan reader and their microstructure analyzed by TEM and SEM.  It was observed that fungus C. tropicum and F. oxysporum Schltdl significantly activate the extra-cellular production of silver nanoparticles. The different sized and spherical shaped nanoparticles have been formed in different strains. With the increase in concentration, the absorbance increased with response to time (24-120h) and temperature. Significantly, the pH was found decreasing with the increase of absorbance.  We presume that these changes initiate new geometry of nanosilver in the cell free solutions. These different shaped, sized and geometry of nanoparticles can be used in the field of medicine for drug formation and diseases diagnosis.
The influence of fallback foods on great ape tooth enamel.
Venue: American Journal of Physical Anthropology

Lucas and colleagues recently proposed a model based on fracture and deformation concepts to describe how mammalian tooth enamel may be adapted to the mechanical demands of diet (Lucas et al.: Bioessays 30 2008 374-385). Here we review the applicability of that model by examining existing data on the food mechanical properties and enamel morphology of great apes (Pan, Pongo, and Gorilla). Particular attention is paid to whether the consumption of fallback foods is likely to play a key role in influencing great ape enamel morphology. Our results suggest that this is indeed the case. We also consider the implications of this conclusion on the evolution of the dentition of extinct hominins.
A honey bee odorant receptor for the queen substance 9-oxo-2-decenoic acid
Venue: Proceedings of the National Academy of Sciences of the United States of America

By using a functional genomics approach, we have identified a honey bee [Apis mellifera (Am)] odorant receptor (Or) for the queen substance 9-oxo-2-decenoic acid (9-ODA). Honey bees live in large eusocial colonies in which a single queen is responsible for reproduction, several thousand sterile female worker bees complete a myriad of tasks to maintain the colony, and several hundred male drones exist only to mate. The “queen substance” [also termed the queen retinue pheromone (QRP)] is an eight-component pheromone that maintains the queen's dominance in the colony. The main component, 9-ODA, acts as a releaser pheromone by attracting workers to the queen and as a primer pheromone by physiologically inhibiting worker ovary development; it also acts as a sex pheromone, attracting drones during mating flights. However, the extent to which social and sexual chemical messages are shared remains unresolved. By using a custom chemosensory-specific microarray and qPCR, we identified four candidate sex pheromone Ors (AmOr10, -11, -18, and -170) from the honey bee genome based on their biased expression in drone antennae. We assayed the pheromone responsiveness of these receptors by using Xenopus oocytes and electrophysiology. AmOr11 responded specifically to 9-ODA (EC50 = 280 ± 31 nM) and not to any of the other seven QRP components, other social pheromones, or floral odors. We did not observe any responses of the other three Ors to any of the eight QRP pheromone components, suggesting 9-ODA is the only QRP component that also acts as a long-distance sex pheromone.
Super black and ultrathin amorphous carbon film inspired by anti-reflection architecture in butterfly wing
Venue: Carbon

An ultrathin and super black amorphous carbon (a-C) film has been fabricated by borrowing the inverse V-type anti-reflection nano-architecture from the black wings of butterfly Ornithoptera goliath through vacuum sintering process. The biomimetic a-C film shows good optical absorption (99%) at low reflectance (
Spider Web Protection Through Visual Advertisement: Role of the Stabilimentum
Venue: Science

The conspicuous white silken adornments known as stabilimenta, which are commonly found in the orb webs of some spiders, appear to be protective devices that warn birds of the presence of webs in their flight path. Webs endowed with artificial equivalents of stabilimenta tended to survive intact the early morning period when birds are on the wing; unmarked webs showed a high incidence of destruction.
Physiological Colour Change in the Hercules Beetle
Venue: Nature

THE Hercules beetle, Dynastes Hercules L., can change the colour of its elytra—horny fore-wings—from black to greenish yellow and back again to black all within a few minutes. It does this in a way previously unknown among insects. Apart from the reversible migrations of pigment granules in the iris cells, physiological or rapidly reversible colour changes are very rare in insects1–4. Among beetles, Coptocyclia5, Aspidomorpha, and many other Cassidinae can change the colour of their elytra by varying the amount of water in the cuticle and thereby the thickness of the thin films responsible for the interference colours.
The Venus Flytrap Dionaea muscipula Counts Prey-Induced Action Potentials to Induce Sodium Uptake
Venue: Current Biology

Carnivorous plants, such as the Venus flytrap (Dionaea muscipula), depend on an animal diet when grown in nutrient-poor soils. When an insect visits the trap and tilts the mechanosensors on the inner surface, action potentials (APs) are fired. After a moving object elicits two APs, the trap snaps shut, encaging the victim. Panicking preys repeatedly touch the trigger hairs over the subsequent hours, leading to a hermetically closed trap, which via the gland-based endocrine system is flooded by a prey-decomposing acidic enzyme cocktail. Here, we asked the question as to how many times trigger hairs have to be stimulated (e.g., now many APs are required) for the flytrap to recognize an encaged object as potential food, thus making it worthwhile activating the glands. By applying a series of trigger-hair stimulations, we found that the touch hormone jasmonic acid (JA) signaling pathway is activated after the second stimulus, while more than three APs are required to trigger an expression of genes encoding prey-degrading hydrolases, and that this expression is proportional to the number of mechanical stimulations. A decomposing animal contains a sodium load, and we have found that these sodium ions enter the capture organ via glands. We identified a flytrap sodium channel DmHKT1 as responsible for this sodium acquisition, with the number of transcripts expressed being dependent on the number of mechano-electric stimulations. Hence, the number of APs a victim triggers while trying to break out of the trap identifies the moving prey as a struggling Na+-rich animal and nutrition for the plant.
Pre-copulatory courtship behavior in a solitary bee, Nomia triangulifera Vachal (Hymenoptera : Halictidae)
Venue: Apidologie

Comportement de cour precopulatoire chez une abeille solitaire, Nomia triangulifera Vachal (Hymenoptera, Halictidae). L'abeille terricole, Nomia triangulifera, presente un comportement de cour complexe avant et pendant l'accouplement. Le comportement d'accouplement a ete etudie sur de grosses aggregations dans une ferme du Nord-Est du Kansas, ou les abeilles nidifient depuis de nombreuses annees. En 1989 et 1990, on a capture des abeilles qui emergeaient afin de determiner la phenologie de l'emergence et d'estimer le sex-ratio journalier d'accouplement (nombre de mâles presents/nombre de femelles receptives)
Adhesive recruitment by the viscous capture threads of araneoid orb-weaving spiders
Venue: The Journal of Experimental Biology

The sticky prey capture threads of orb-webs are critical to web performance. By retaining insects that strike the web, these spirally arrayed threads allow a spider time to locate and subdue prey. The viscous capture threads spun by modern orb-weaving spiders of the Araneoidea clade replaced the dry, fuzzy cribellar capture threads of the Deinopoidea and feature regularly spaced moist, adhesive droplets. The stickiness of a cribellar thread is limited by its tendency to peel from a surface after the adhesion generated at the edges of contact is exceeded. In this study we test the hypothesis that viscous thread overcomes this limitation by implementing a suspension bridge mechanism (SBM) that recruits the adhesion of multiple thread droplets. We do so by using contact plates of four widths to measure the stickiness of six species' viscous threads whose profiles range from small, closely spaced droplets to large, widely spaced droplets. The increased stickiness registered by an increased number of thread droplets supports the operation of a SBM. However, the accompanying decrease in mean per droplet adhesion shows that droplets interior to the edges of thread contact contribute successively less adhesion. Models developed from these data suggest that the suspension bridge mechanism is limited to a span of approximately 12 droplets.
Parasites and mutualism function: measuring enemy-free space in a fig–pollinator symbiosis
Venue: Oikos

Mutualisms involve cooperation between species and underpin several ecosystem functions. However, there is also conflict between mutualists, because their interests are not perfectly aligned. In addition, most mutualisms are exploited by parasites. Here, we study the interplay between cooperation, conflict and parasitism in the mutualism between fig trees and their pollinator wasps. Conflict occurs because each fig ovary can nurture either one seed or one pollinator offspring and, while fig trees benefit directly from seeds and pollinator offspring (pollen vectors), pollinators only benefit directly from pollinator offspring. The mechanism(s) of conflict resolution is debated, but must explain the widespread observation that pollinators develop in inner, and seeds in outer, layers of fig flowers. We recently suggested a role for non-pollinating figs wasps (NPFWs) that are natural enemies or competitors of the pollinators and lay their eggs through the fig wall. Most NPFW offspring develop in outer and middle layer flowers, suggesting that inner flowers provide enemy-free space for pollinator offspring. Here, we test the hypothesis that NPFWs cannot reach inner flowers, by measuring wasp and fig morphology at the species-specific times of NPFW attack in the field. We found that three species of Sycoscapter and Philotrypesis wasps that parasitise pollinators could reach 34–73%, 75–92% and 82–97% of fig ovaries, respectively. Meanwhile, Eukobelea and Pseudidarnes gall-formers, despite having shorter ovipositors, can access almost all fig flowers (93–99% and 100%), because they attack smaller (younger) fig fruits. Our mechanistic results from ovipositing wasps support spatial patterns of wasp offspring segregation within figs to suggest that inner ovules provide enemy-free-space for pollinators. This may contribute to mutualism stability by helping select for pollinators to avoid laying eggs where they are likely to be parasitised. These outer flowers then remain free to develop as seeds, promoting mutualism persistence.