Miracle-dz/UniFAR-FTUs huggingface dataset:
Ecological control: In vitro inhibition of anaerobic bacteria by oral streptococci

It has been proposed that oral malodour occurs at neutral and alkaline pH, and is inhibited by an acid environment. Thus the production of lactic and acetic acids from carbohydrate fermentation by oral streptococci generates a low pH that can interfere with the growth of other microorganisms. Additionally, some streptococci may produce hydrogen peroxide (H2O2) and/or bacteriocins. The purpose of this study was to investigate whether products of streptococcal growth and carbohydrate metabolism had any effect in vitro on the growth of selected anaerobes associated with oral malodour. Oral streptococci were compared for their ability to ferment glucose or sucrose using acid indicator media and pH measurement, and for their ability to produce H2O2. The inhibition of anaerobes by end products of streptococcal growth in glucose-containing medium was evaluated using both an agar overlay technique and a cross-streak technique. Anaerobic bacteria were inhibited by products of growth of oral streptococci, particularly strains of Streptococcus mutans and Streptococcus salivarius in the presence, but not in the absence, of glucose. It is most likely that this inhibition results from the production of lactic acid rather than H2O2 or bacteriocins, because the pattern of inhibition agreed more with acidogenicity than with any other variable. Oral streptococci may play an important role in the ecology of the oral flora and in the control of oral malodour.
Electric and Magnetic Fields in Stem Cell Research

Life of vertebrates, including humans, starts with a fertilized egg, the zygote. During early embryonic development at blastocyst stage the stem cells become prominent. These cells, in time, differentiate into approximately 200 types of cells, which form all the organs of the body. In this process of differentiation, various endogenous and exogenous factors are involved. Electromagnetic fields (EMFs) are one of those factors. Among endogenous factors, epigenetic mechanisms are involved in switching genes on and off as and when required for the differentiation of a specific organ. EMFs seem to have a key role in modulating these epigenetic factors. Very little is known of these factors and their interactions; our understanding of these factors would help in harnessing stem cells in regenerative medicine.
The peripheral fields of octopus stellar nerves

Afferent activity in the stellar nerves of Octopus vulgaris has been recorded in response to a probe applying a mechanical stimulus of approximately 5 gm/mm2 to the inner surface of the mantle. Mechanical sensitivity is distributed throughout the mantle surface and there is a large degree of overlap between the peripheral fields of nearby stellar nerves but no overlap of either ventral or dorsal midline. The afferent activity probably results from stimulation of sensory receptors located in the mantle and skin, but antidromic discharge in motor fibres is also possible.
T Cell Receptor ζ Allows Stable Expression of Receptors Containing the CD3γ Leucine-based Receptor-sorting Motif*

The leucine-based motif in the T cell receptor (TCR) subunit CD3γ constitutes a strong internalization signal. In fully assembled TCR this motif is inactive unless phosphorylated. In contrast, the motif is constitutively active in CD4/CD3γ and Tac/CD3γ chimeras independently of phosphorylation and leads to rapid internalization and sorting of these chimeras to lysosomal degradation. Because the TCRζ chain rescues incomplete TCR complexes from lysosomal degradation and allows stable surface expression of fully assembled TCR, we addressed the question whether TCRζ has the potential to mask the CD3γ leucine-based motif. By studying CD4/CD3γ and CD16/CD3γ chimeras, we found that CD16/CD3γ chimeras associated with TCRζ. The CD16/CD3γ-TCRζ complexes were stably expressed at the cell surface and had a low spontaneous internalization rate, indicating that the leucine-based motif in these complexes was inactive. In contrast, the CD4/CD3γ chimeras did not associate with TCRζ, and the leucine-based motif in these chimeras was constitutively active resulting in a high spontaneous internalization rate and low expression of the chimeras at the cell surface. Thus, our data demonstrate that TCRζ allows stable cell surface expression of receptors containing CD3γ leucine-based motifs by its potential to mask such motifs.
WHAT IS A WINTER FLOATER? CAUSES, CONSEQUENCES, AND IMPLICATIONS FOR HABITAT SELECTION

Abstract Abstract. In migrant birds, winter social systems reflect strategies of habitat use. The best-studied strategy is that of a fixed home range or territory. Alternative strategies to holding a territory, such as floating and flocking behaviors, suggest different processes of habitat selection. Whereas flocking, like territoriality, is a well-studied social strategy, solitary nonterritorial (floater) behavior is difficult to study and is thus poorly understood in terms of its causes, consequences, and implications for habitat selection. Floaters are individuals of a primarily stationary population which move over large areas compared to the average home range size. We review evidence of the causes, consequences, and frequency of winter floating behavior, focusing primarily on migrant songbirds. We also address the endocrine basis of alternative behavioral strategies by presenting results from aviary-based dominance trials with Hermit Thrushes (Catharus guttatus). Results from this study and others suggest that the adrenocortical response to social stress plays a key role in both the proximate and ultimate causes of floating behavior. Because winter floating behavior exists in many migrant songbird species, better understanding of winter floaters may be important for population modeling and conservation planning.
The physiological basis of seed dormancy in Avena fatua. VII. Action of organic acids and pH

Citric, succinic, fumaric, malic, pyruvic and lactic acids induced germination in two genetically pure dormant lines of Avena fatua L. The sensitivity to these acids was low immediately after harvest and increased markedly after a period of dry after-ripening. Because the acids could only overcome dormancy in partly after-ripened caryopses, the mode of their action in these caryopses differed from that of another germination promotor, ethanol, and was similar to that of the germination promoter, sodium nitrate. The mode of action of the organic acids on the partly after-ripened caryopses through lowering pH was indicated by the observation that other non-metabolic weak acids could also break dormancy while neutral pH value salt solutions of some of the tested acids were inactive. The dose-response curves of citric acid for the stimulation of germination and for oxygen uptake were similar, indicating that this organic acid may stimulate germination by promoting oxygen uptake. A time sequence study showed that citric acid stimulated oxygen uptake before the first visible signs of germination. Stimulation of germination and oxygen uptake over a range of pH values showed that those values of pH which stimulated germination also stimulated oxygen uptake, indicating that the ability to stimulate oxygen uptake was not confined to organic acids. The stimulation of both germination and oxygen uptake by citric acid was not inhibited by salicylhydroxamic acid, an inhibitor of alternative respiration, therefore stimulation of both germination and oxygen uptake by citric acid does not require the operation of the alternative pathway of respiration. The function of weak acids as promoters of oxygen uptake is discussed with reference to the breakage of dormancy in partly after-ripened caryopses and the involvement of various respiratory pathways is indicated.
Cranial morphology of Platypterygius longmani Wade, 1990 (Reptilia : Ichthyosauria) from the Lower Cretaceous of Australia.

Exceptionally well-preserved remains belonging to the Australian Early Cretaceous (Albian) ichthyosaur Platypterygius longmani Wade, 1990 are described in detail. The material is used to reconstruct some of the cranial musculature and provide a brief functional analysis of the skull and mandible. Preparation of specimens using acetic acid and application of high-resolution X-ray computed tomographic analyses has revealed many previously unrecorded anatomical details, including the absence of a coronoid and squamosal, and the presence of well-developed epipterygoid facets on the pterygoid and parietal (possibly indicating retention of an unossified epipterygoid element). Reconstruction of the jaw musculature suggests a well-developed m. adductor mandibulae internus pterygoideus (serving to close the jaws against inertia and drag of the surrounding water), and possibly an m. intramandibularis (acting to accentuate static pressure along the elongate mandible when the jaws were closed). Despite its large size (maximum total body length of around 7 m), the long, narrow snout of P. longmani (together with preserved gut contents) indicates selective feeding on relatively small prey such as fish, small tetrapods and probably cephalopods. Large orbits are indicative of a visual hunter, but extensive external passages for nerves and blood vessels might suggest the presence of a dermal sensory system. The massive stapes appears to have lost all sound conductive function, serving primarily as structural support in the basicranial region. © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society, 2005, 145, 583–622.
Conserving energy at a cost to biodiversity? Impacts of LED lighting on bats

Artificial lighting is a key biodiversity threat and produces 1900 million tonnes of CO 2 emissions globally, more than three times that produced by aviation. The need to meet climate change targets has led to a global increase in energy‐efficient light sources such as high‐brightness light‐emitting diodes (LEDs). Despite the energetic benefits of LEDs, their ecological impacts have not been tested. Using an experimental approach, we show that LED street lights caused a reduction in activity of slow‐flying bats ( Rhinolophus hipposideros and Myotis spp.). Both R. hipposideros and Myotis spp. activities were significantly reduced even during low light levels of 3.6 lux. There was no effect of LED lighting on the relatively fast‐flying Pipistrellus pipistrellus, Pipistrellus pygmaeus and Nyctalus/Eptesicus spp. We provide the first evidence of the effects of LED lights on bats. Despite having considerable energy‐saving benefits, LED lights can potentially fragment commuting routes for bats with associated negative conservation consequences. Our results add to the growing evidence of negative impacts of lighting on a wide range of taxa. We highlight the complexities involved in simultaneously meeting targets for reduction of greenhouse gas emissions and biodiversity loss. New lighting strategies should integrate climate change targets with the cultural, social and ecological impacts of emerging lighting technologies.
Water balance and rectal absorption in the grasshopper Oedipoda

ABSTRACT. The xeric grasshopper Oedipoda germanica pyrenaica (Uvarov, 1936) has a daily cycle of water‐gain from feeding during the afternoon and water‐loss at night. The afternoon peak of water‐gain in laboratory animals is correlated with a short‐term rise in the osmotic pressure of the haemolymph in field animals. It is estimated that starved large animals would deplete their water reserves within 8–11 days. Water loss in faeces production is a major component of total water loss only during the late afternoon to early evening; at all other times transpiratory water losses are considerably greater. Overall, 23% of the daily water loss occurs through the faeces. From hindgut cannulation experiments, c. 80% of water entering the rectum is reabsorbed. A comparison of transpiratory water losses of xeric and mesic Orthoptera and some xeric Coleoptera revealed that water losses are some 6–7 times higher in Orthoptera than in similar sized Coleoptera.
Interrelationships of lower actinopterygian fishes

The lower actinopterygian fishes are classified using dermal skull roof pattern, in particular the various configurations displayed by the bones on the otic branch of the infraorbital canal (dermosphenotic, intertemporal-supratemporal/dermopterotic). Where possible these patterns are related to the sequential acquisition of derived features, and the resulting cladogram represents a synthesis of dermal bone pattern and endochondral and dermal skeletal characters. We have proposed 27 terminal groups which we tentatively regard as monophyletic and have concluded that Polypterus is the most primitive living taxon, that the Chondrostei is the sister-group of Saurichthys and Luganoia the most derived stem-group neopterygian.
The Uptake of Gaseous Ammonia by the Leaves of Italian Ryegrass

Lockyer, D. R. and Whitehead, D. C. 1986. The uptake of gaseous ammonia by the leaves of Italian ryegrass. —J. exp. Bot. 37: 919-927. Plants of Italian ryegrass (Lolium multiflorum Lam.) grown in soil with two rates of added 15N-labelled nitrate were exposed, in chambers, for 40 d to NH3 in the air at concentrations of 16,118 and 520 fig m " 3. At the highest concentration of NH3, this source provided 47-3% of the total nitrogen in plants grown with the lower rate of nitrate addition (100 mg N kg"1 dry soil) and 35-2% with the higher rate (200 mg N kg"1 dry soil). At the intermediate concentration of NH3, the contributions to total plant N were 19-6% and 10-8%, respectively, at low and high nitrate while, at the lowest concentration of NH3, they were 5-1% and 3-2%. Most of the N derived from the NH3 remained in the leaves, but some was transported to the roots. The amount of N derived from the NH3 that was present in the leaves was not reduced by washing the leaves in water at pH 5 0 before harvesting, indicating that the N was assimildtttl-by the plant and not adsorbed superficially. Rates of uptake of NH3 per unit leaf area ranged from 1-7 fig dm"2 h"1 at a concentration of 16/rgm"3 to 29-0 /igdm"2 h 1 at a concentration of 520 fig m " 3 and with the lower rate of nitrate addition. Increasing the supply of nitrate to the roots slightly reduced the rate of uptake of NH3 per unit leaf area. Uptake of N from the higher rate of nitrate was reduced at the highest concentration of NH3 in the air. Key words—Ammonia, nitrogen, leaf sorption, Lolium multiflorum. Correspondence to: The Animal and Grassland Research Institute, Hurley, Maidenhead, Berkshire SL6 5LR, U.K.
Vasculature-guided neural migration in mouse cerebellum

Abstract Neural migration is regarded as a key step for cortical development and cortical lamination. While classical theory holds that immature neurons migrate to their destinations along radial glia, there is some preliminary evidence showing that vasculature is probably involved in that process as well. In this study, we compared vascular development with that of radial glia and the migration of neurons, so that the relationships among them could be elucidated. We found that the radial glial cells and vasculature were highly similar in their distribution and development. For instance, in the external granular layer (EGL, the putative molecular layer), the processes of radial glial cells were arranged in an orderly radial pattern, whereas in the deep areas of the cerebellum, their arrangements were in relative disorder. On the other hand, the vasculatures in EGL were usually orientated radially, which paralleled the projections of radial glia; however, the distribution of vasculature in the internal granular layer (IGL, the putative granular layer) and white matter was in relative disorder as well, similar to the pattern exhibited by radial glial processes. This high harmonization between vasculature and radial glia suggests their interconnected biological relationships during cerebellar development and neural migration. We also observed that a large number of newborn neurons were migrating along blood vessels, suggesting that the vasculature could serve as a scaffold for cell migration. In conclusion, cerebellar vasculature could guide neural migration not only as a platform for biological interaction with radial glia, but also serve scaffolding functions for neural migration.
Phenotypic Plasticity: Beyond Nature and Nurture

Contents: Series Editor's Foreword, by Samuel M. Scheiner Foreword, by Paul Brakefield Preface Chapter 1: What is Phenotypic Plasticity? Chapter 2: Studying and Understanding Plasticity Chapter 3: A Brief (Conceptual) History of Phenotypic Plasticity Chapter 4: The Genetics of Phenotypic Plasticity Chapter 5: The Molecular Biology of Phenotypic Plasticity Chapter 6: The Developmental Biology of Phenotypic Plasticity Chapter 7: The Ecology of Phenotypic Plasticity Chapter 8: Behavior and Phenotypic Plasticity Chapter 9: Evolution of and by Phenotypic Plasticity Chapter 10: The Theoretical Biology of Phenotypic Plasticity Chapter 11: Phenotypic Plasticity as a Central Concept in Evolutionary Biology Epilogue: Beyond Nature and Nurture Notes References Author Index Subject Index
Distance decay is uncommon in large‐scale population synchrony of common moths: does it promote vulnerability to climate change?

Large‐scale spatial synchrony is common in population dynamics. In nearly all empirical data sets, population synchrony decays with distance. Large‐scale spatial population synchrony of 20 common moth species was studied using 367 separate light‐trap time series of 3–27 years, at 13–19 localities in southern Finland. The maximum distance between trap sites was ca 1075 km. The degree of spatial synchrony in three weather variables (daily mean and minimum temperature, and daily total precipitation) from 15 weather stations was also studied. Data were analysed with spatial non‐parametric correlation functions (Sncf). Statistically significant large‐scale spatial synchrony in population fluctuations occurred in 85% of the species (Scotopteryx chenopodiata, Eulithis populata, Chloroclysta citrata, Epirrita autumnata, Perizoma alchemillata, P. didymata, Eupithecia pusillata, Macaria wauaria, Itame brunneata, Cabera pusaria, C. exanthemata, Eilema lurideola, Rusina ferruginea, Amphipoea fucosa, Orthosia gothica, Cerapteryx graminis and Diarsia mendica), as well as in all weather variables. Spatial synchrony decreased with distance (=distance decay) in 45% of the species, and there was no indication of distance decay in the remaining species. Climate change is likely to cause an increasing frequency of extreme weather events, and insects are strongly affected by such environmental stochasticity. In combination with the high frequency of large‐scale spatial synchrony, which did not show distance decay as a rule in these data, even currently common moth species may become threatened in the near future.
Further Comments on the Evidence for Multiple Stable Points in Natural Communities

Peterson (1984) argues that we have applied unnecessarily strict criteria in evaluating evidence for the existence of multiple stable points in natural communities (Connell and Sousa 1983). In particular, he disagrees with the blanket application of our criterion that "when alternate or multiple stable states are postulated to exist, it is essential to establish that any relevant conditions of the abiotic environment are similar (in average value and in variance) in both situations" (Connell and Sousa 1983, p. 792). Peterson (1984, p. 128) suggests that this criterion would eliminate from consideration cases in which "the differences in environment between sites occupied by alternative communities may be extreme, merely as a historical consequence of feedbacks between the biota and the physical environment. Furthermore, if cases of multiple stable points do exist in natural systems, this feedback between the organisms and their local environment would seem to me to be one of the most likely mechanisms involved in maintaining the alternative states. " We agree that if this suggested feedback actually operates in nature, it represents an important mechanism. Therefore, we will address two points in this paper: (1) the nature of the evidence needed to demonstrate the feedback mechanism; and (2) the adequacy of the evidence supporting any proposed examples of it. In regard to the first point, we propose two criteria that need to be satisfied before evidence can be accepted as demonstrating the existence of the feedback mechanism. (1) If significant differences are observed between the two sites in any relevant environmental variables, they must be shown to result from the influence of the different resident populations rather than being of extrinsic abiotic origin. (By "relevant" we mean those environmental variables that exert a statistically significant effect on density or rate of population growth.) (2) The environment on each of the two sites, modified as above, should have properties that both result in self-replacement of the resident population, and reduce the likelihood of invasion of the alternative population from the other site. Our second point concerns the adequacy of evidence for the existence of the feedback mechanism in natural populations. Peterson (1984, p. 128) gives several "potential (but not yet adequately demonstrated) examples" of it. He is correct in this assessment and we would like to discuss their inadequacies in regard to each of the above criteria. One of his examples satisfies both criteria for one of the two proposed alternative stable states. Vivrette and Muller (1977) showed that the ice plant, Mesembryanthemum crystallinum, increases the salt content of the soil beneath it. This apparently inhibits germination of grasses and enhances that of its
First Observations on the Effect of a Complete, Exceptional Overturn of Lake Maggiore on Plankton and Primary Productivity

This manuscript presents some results of a monitoring of the planktonic communities of Lago Maggiore during the complete overturn of the lake in the winter of 1998/1999. These results are of particular interest not only because holomixy is a rare event in this well-known water body, but also because these are the first such results obtained after a significant change in the lake's trophic status. Holomixy can be regarded as a “whole lake experiment” sensuEdmondson (1993): irrespective of the mechanisms underlying the process, it produces an internal enrichment of algal nutrients, and particularly of phosphorus. The increase in biomass and productivity of phytoplankton seems to be driven more by the increase in phosphorus than by a decrease in potential grazers. However, once the luxury amount of nutrients supplied by the overturn was exhausted, the photosynthetic productivity decreased to values more typical of a “normal” spring productivity, in accordance with the present trophic condition of the lake. Similarly, the enhancement of phytoplankton growth seems likely to have stimulated the numerical increase of zooplankton, and especially of small, fast reproducing rotifer species. Moreover, the spring pulse of primary productivity and the phosphorus enrichment represent a crucial phase for the storage of the potential energy necessary for the development of the zooplankton population, particularly of cladocera, in summer.