The stimulating effects of ethylene and auxin on petiole elongation and on hyponastic curvature are independent processes in submerged Rumex palustris

The flooding-tolerant plant species Rumex palustris (Sm.) responds to complete submergence with stimulation of petiole elongation mediated by the gaseous hormone ethylene. We examined the involvement of auxin in petiole elongation. The manipulation of petiolar auxin levels by removing the leaf blade, or by addition of synthetic auxins or auxin transport inhibitors, led to the finding that auxin plays an important role in submergence-induced petiole elongation in R. palustris. A detailed kinetic analysis revealed a transient effect of removing the auxin source (leaf blade), explaining why earlier studies in which less frequent measurements were taken failed to identify any role for auxin in petiole elongation. We previously showed that the onset of stimulated petiole elongation depends on a more upright petiole angle being reached by means of hyponastic (upward) curvature, a differential growth process that is also regulated by ethylene and auxin. This raised the possibility that both ethylene and auxin stimulate elongation only indirectly by influencing hyponastic growth. We show here that the action of ethylene and auxin in promoting petiole elongation in submerged R. palustris is independent of the promoting effect that these hormones also exert on the hyponastic curvature of the same petiole.     

Photography: conservation and restoration problems of archives

Summary The more and more numerous photographs witnessing the past are often kept, or better, forgotten and confined to the attics and cellars and are thus running the risk of an irreparable deterioration or worse, of an impending and probable destruction. The study of photograph production systems, the analysis of components and thus the chemico-physical investigations are of extreme importance. Nonetheless the aerobiological research is essential for the daily management of archives.     

On techniques for stabilising and photographing skulls

The design and use of a small light portable craniostat is described. Made of clear polystyrene, with adjustable pegs of the same material, the device is small, light, unbreakable and easily portable. It facilitates rapid and stable positioning of skulls in any position for study of photography.     

Picture worth a thousand words: Updating repeat photography for 21st century ecologists

1. Anthropogenic climate change is altering every ecosystem on Earth. Understanding these changes requires quality baseline measurements of ecosystem states. While satellite imagery provides a coarse baseline for regional‐scale changes in vegetation, landscape‐scale observations are lacking. Ground‐based repeat photographic points (RPP) can provide this finer baseline. As precise visual records of ecosystems at a particular time, RPP provide rich data for diverse uses. Current methodology for establishing RPP, developed in the era of film cameras, requires placement of permanent markers in a landscape to provide accurate repeats over time. Another form of RPP involves relocating sites of historic photographs, to assess change between historic and present‐day photographs. Through a three‐year field survey, we synthesized these techniques to modernize repeat photography for the 21st century ecologist.
2. We established 100 RPP in the Peloncillo Mountains of New Mexico, recapturing 86 RPP in the three years (2015–2017) of the study. During our study, a large (>16,000 ha) complex of wildfires burned more than half of the RPP sites we established in the prior month, providing a unique opportunity to assess method accuracy after dramatic landscape disturbance by comparing burned, unburned, pre‐, and post‐fire RPP image recapture precision.
3. Our method produced 92% mean similarity for 86 RPP between original and repeated photographs, with no difference between burned and unburned sites. Interval between photographs did not cause a decline in similarity.
4. Our updated methods can be practically applied to nearly all terrestrial study systems. Landscape changes driven by human (e.g., effects of anthropogenic climate change, land use) and natural activities (e.g., wildfires, phenology, and hydrologic events) are especially well suited to our updated methods. Modern smartphones include the technology necessary (e.g., camera, GPS, and compass) to employ our method and provide a means for low‐cost deployment of the technique in diverse landscapes. We encourage broad adoption of this technique to establish baseline RPP of ecosystems across the globe, and the formation of a centralized database for repeat photography.

     

Evaluation of the distortion of photographs using various focal lengths

It is of interest to evaluate the distortion of intraoral frontal photographs using various focal lengths. Intra-oral frontal view pictures of 20 subjects were taken using a standard 18-55mm lens of a DSLR camera at three different focal lengths (18mm, 35mm, 55mm). 52 experienced orthodontists were chosen and they were asked to assess the photographs and choose the one with the least amount of distortion. Majority of the orthodontists selected the frontal photograph taken at a focal length of 35mm as the best photo with the least distortion among the three photographs. The photos taken at a focal length of 35 mm showed the least amount of distortion.     

From sneaker to bourgeois male: Long-term observations on recognized tompot blenny Parablennius gattorugine individuals reveal new information on their biology

The behaviour of the tompot blenny Parablennius gattorugine was studied by underwater observation and photography on the south-west coast of the UK over an 11 year period, with >50 individuals identified at two locations by their distinctive skin markings. Observations showed males engaging in rapid swimming behaviour when approached by a female, and younger males using alternative ‘sneaker’ tactics before becoming ‘bourgeois’ territory-holders. The noninvasive recognition technique also facilitated detailed observations on territory retention (up to 7 years) and agonistic behaviours among both males and females.     

The Use of Polarised Light in Photography of Macrofossils

An elaboration of a little known technique involving the use of polarised light sources, together with a polarising filter over the camera lens is described and used to demonstrate its usefulness in the photography of low contrast fossils.     

A novel multiple subdivision-based algorithm for quantitative assessment of retinal vascular tortuosity

Vascular tortuosity as an indicator of retinal vascular morphological changes can be quantitatively analyzed and used as a biomarker for the early diagnosis of relevant disease such as diabetes. While various methods have been proposed to evaluate retinal vascular tortuosity, the main obstacle limiting their clinical application is the poor consistency compared with the experts’ evaluation. In this research, we proposed to apply a multiple subdivision-based algorithm for the vessel segment vascular tortuosity analysis combining with a learning curve function of vessel curvature inflection point number, emphasizing the human assessment nature focusing not only global but also on local vascular features. Our algorithm achieved high correlation coefficients of 0.931 for arteries and 0.925 for veins compared with clinical grading of extracted retinal vessels. For the prognostic performance against experts’ prediction in retinal fundus images from diabetic patients, the area under the receiver operating characteristic curve reached 0.968, indicating a good consistency with experts’ predication in full retinal vascular network evaluation.     

Monitoring vegetation recovery in the early stages of the Dirk Hartog Island Restoration Programme using high temporal frequency Landsat imagery

Dirk Hartog Island is the largest island off the West Australian coast. From the 1860s to 2008, the island was managed as a pastoral lease. In 2009, the island was gazetted as a National Park and the process of removing introduced animals, to allow for the reintroduction of a suite of 12 native mammal species, began. With the removal of high numbers of goats and sheep concerns were raised regarding the proliferation of weed species (which would no longer be controlled through grazing) and the ability of the island’s native vegetation to recover. A vegetation monitoring programme was developed which integrated detailed floristic surveys, repeated site photography and Landsat time series data to provide a comprehensive picture of how the island’s vegetation cover had changed since destocking. The integration of these elements has allowed present‐day observations to be put into context of longer term landscape dynamics. Through statistical analysis of temporal sequences of Landsat satellite imagery, the timing of changes to phenology and cover at monitoring sites was related directly to the management action of stock removal. With the use of field observations, the species responsible for the increase in cover were identified. These data sources, when analysed together, allowed management to have confidence that, following destocking, native vegetation cover is increasing.     

Do blood-borne calcifying nanoparticles self-propagate?

The nanotechnology industry is currently in the process of producing new nanoparticles. The biological activity of nanoparticles including adverse as well as beneficial effects tends to increase as their size decreases. The smaller the particles are, the greater their bioactivity and toxicity. Thus, one can easily conjecture the impact ofa nanoparticle if it could also self-replicate. This in vitro study reveals the self-propagating ability of unique calcifying nanoparticles (CNP) that can be as small as 50 nm in size and found in blood, blood products, and calcified soft tissues. Although specific detection techniques, morphological characteristics and biomineralizing properties of CNP are well established, their genomic information and self-propagating capability have always been challenged. The objective of this study is to document the propagation of CNP under physiological conditions, using inverted light microscopy (LM) and the Biostation IM time-lapse imaging system. Their detailed morphological structure was examined using scanning (SEM) and transmission (TEM) electron microscopy. This present study, in conjunction with previous findings of metabolic activity, antibiotic sensitivity, antibody specificity, morphological aspects and infectivity, validates CNP as self-replicators. Therefore these sterile-filterable, blood-borne nanoparticles should be of concern to the nanomedicine industry.     

Photographic estimation of photosynthetically active radiation: evaluation of a computerized technique

Summary We describe a computerized technique for the analysis of hemispherical photographs of sites within plant canopies. The analysis yields estimates of canopy openness, a summary of the spatial distribution of canopy openings, estimates of direct and diffuse site factors, predicted times and durations of sunflecks for any date, and predicted daily courses of photosynthetically active photon flux density (PFD) for any date and for horizontal as well as inclined surfaces. By comparing estimates from photographs with measured values in 32 tropical forest microsites, we evaluate this technique and assess its potential and limitations. In sites of widely varying light availability, and with predictions specific to leaves at various angles, measured daily PFD correlated strongly (r=0.908) with predictions from photographs. Measured daily PFD was also closely correlated with estimates, from the photographs, of diffuse and direct site factors (r>0.8). Differences between predictions and measurements were proportionately largest in heavily shaded sites. Under clear conditions, this technique reliably predicted both daily PFD and the temporal pattern of PFD including predicting suflecks lasting more than a few minutes. However, temporal patterns of PFD predicted from photographs differ in potentially important details from measured patterns.C.I.W.D.P.B. Publication no. 935     

Light from maillard reaction: Photon counting,emission spectrum,photography and visual perception

Several authors have reported on high-sensitivity measurement of oxygen-dependent low-level chemiluminescence (CL) from Maillard reactions (MR), i.e. nonenzymatic amino-carbonyl reactions between reducing sugars and amino acids (also referred to as nonenzymatic browning). Here we report for the first time, that light from Maillard reactions can be seen by the human eye and also can be photographed. In parallel with visual perception and photography CL was monitored by means of a CL-detection programme of a liquid scintillation counter (LSC, single photon rate counting). CL emission spectrum was recorded by a monochromator-microchannel plate photomultiplier arrangement. CL intensity from reaction of 6-aminocaproic acid with D-ribose (200 mg each) in 5 mL H₂O at pH 11 at 95°C was high enough for visual perception after adaptation to absolute darkness. Reaction in dimethylsulphoxide (DMSO) exhibited strongly enhanced CL (10 mg each in 5 mL were sufficient for visual detection) and could be photographed (15 minutes' exposure, ASA 6400); all characteristics of Maillard specific CL (O₂-dependence, no CL from nonreducing sugars, inhibition by sulphur compounds) remained. Visual detection of CL and measurement by LSC were in full concordance. The CL emission spectrum showed two broad peaks at around 500 nm and 695 nm. Fluorescence emission of the brown reaction mixture matched the bluegreen part of the CL emission spectrum. Emission of visible light during Maillard reactions may partly originate from oxygen-dependent generation of excited states and energy transfer to simultaneously formed fluorescent products of the browning reaction.     

Epiboly connected with cleavage in morula and early blastula stages of Xenopus laevis,a study using time-lapse photography

Summary Measurements were made of the external surface areas occupied by animal and vegetal blastomeres and their daughter cells at successive cleavage cycles in 15 embyros of Xenopus laevis. On the animal side, after each cleavage a general area increase (epiboly) occurs from cycle 4 (16-cell stage, stage 5) to cycle 10 (stage 8 1/2), while on the vegetal side there is a slight general area decrease after each cleavage from cycle 6 to cycle 10. The comparison between the external surface areas of individual animal blastomeres and those of their daughter cells, visible at the next cycle, shows a significantly larger increase after radial than after tangential cleavage, a difference that may be connected with the insertion of new membrane into the external surface at radial cleavage.     

‘Black and white,a significant contrast’: Race,humanism and missionary photography in the Pacific

Taking the example of ‘Studies in black and white’, a genre of photographs taken around the end of the nineteenth century by Methodist missionaries in the Pacific, this article seeks to go beyond conventional analyses that scrutinize colonial photography for forms of domination. I argue that these photographs, and the context in which some of them were published, reveal a complex interplay between two contradictory principles: on the one hand, a Christian humanism, articulating a vision of commonality and equality, and on the other, paternalism, articulating a vision of superiority and inequality .      

Using time-lapse digital video recording for a nesting study of birds of prey

Remote photography using various photo, movie or video devices has been employed in numerous studies in wildlife research during the last 50 years. Given the rapid advances in digital technologies, digital video and photo techniques are becoming more common in use, and publications that introduce a new method or equipment for video surveillance in wildlife research (and in ornithological studies particularly) are appearing almost every year. However, still no special guide to the great variety of equipment and methods is available, and the choice and use of suitable gear for scientific purposes may be difficult for non-specialists. In this paper, we review the most common surveillance techniques used in today’s nest studies, as well as the most essential properties of image recording equipment. We also describe the digital video recording technique, which we used for observations of raptor nests, and summarise our experience of its operation. As an example of the obtained data, we present the timing of prey deliveries of goshawks and common buzzards.     

Quantitative characterization of domes in primary mouse mammary epithelial tumor cell cultures

Summary Dome populations from primary cultures of mouse mammary tumor cells were quantitatively studied in regard to size, distribution, density and the area occupied by light-diffusion photography and image analysis. The effects of fetal bovine serum, insulin and hydrocortisone were analyzed. Quantitative characterization documented dome diameter (mode diameter 0.26 to 0.52 mm), dome area occupied (average 23%, maximum 38.7%), and density (average 78 domes per cm², maximum 117 domes per cm²) for standard culture conditions. Insulin and hydrocortisone had a primary effect on dome density whereas 15% fetal bovine serum had a minimal effect. However, insulin and hydrocortisone had a synergistic optimal effect on dome population. Time-lapse cinematography revealed that the dome population is not static, but a very dynamic one. Domes underwent irregular pulsations of expansion and contraction. Dome enlargement was either by a series of expansions and contractions, by lateral involvement of other cells, or by coalescence of two or more domes. Domes have been considered to be the in vitro counterpart of the in vivo acinus of the mouse mammary gland. However, quantitative dome population characterization has not been available. Dome analysis by light-diffraction photography and image analysis lends itself towards correlative studies of domes and their differentiative products. Supported in part by Public Health Service Contract NO1-CP 61013 within the Virus Cancer Program of the National Cancer Institute and by Public Health Service Training Grant CA05245 from the National Cancer Institute.     

利用半球图像法提取植被冠层结构特征参数

植被冠层结构深刻地影响着植物群落与环境的相互作用,对植被冠层结构的研究是深入理解植被生态系统格局、过程及其运作机制的重要基础。冠层结构特征参数的快速测量方法是植被冠层结构研究的前提,目前测量方法主要是基于实际测量的地面法,地面法一般费时费力,受人为因素影响较大,因此本文探索利用半球图像法获取植被冠层结构特征参数。通过对半球图像进行几何纠正并建立参数图层,与分类后的植被冠层图层进行运算提取植被冠层结构特征参数。将该方法应用于祁连山旺腰沟流域青海云杉冠层结构特征参数的提取,包括植被冠幅、冠层面积、冠层周长等,结果显示：半球图像法能够较好的提取植被冠层结构特征参数,该方法具有简单、客观、可重复等优点,也可作为植被冠层结构变化的监测方法。     

Complete intra-annual cycle of leaf area index in a Platanus orientalis L. stand

Leaf area index (LAI) analysis of deciduous forest trees is usually restricted to seasonal monitoring involving the assessment of distinct leaf phenological stages within definite time intervals of the year. However, continuous LAI monitoring that includes entire leaf periods is necessary to define the ecophysiological characteristics of deciduous trees. Therefore, this study investigated the intra-annual cycle of the LAI for a Platanus orientalis L. stand in the Bart?n watershed of Turkey. A complete cycle involves three periods: foliation, stable, and defoliation. The foliation period comprises budburst, leaf emergence and flushing sessions, whereas the defoliation period consists of leaf senescence and leaf fall sessions. The stable period is in between these two periods when LAI values are at a climax around maximum. Eight points were determined in the field for the analysis of LAI by a hemispherical photography technique. Over a relatively frequent schedule, photographs were taken almost weekly during the foliation period. Both weekly and approximate monthly photographs were applied during the stable period. Finally, near-monthly photographs were taken for the defoliation period. The foliation period lasted for about 1.5 months from mid-April to May with the mean LAI reaching from 0.16 up to 2.38. Mean LAI was between 2.38 and 2.47 for a stable period over 2 months (June and July). For the defoliation period, mean LAI dropped from 2.42 down to 0.35 over 5 months from August to December. The total foliated period was more than 8 months, which is relatively long for a temperate forest. In addition, correlations between mean LAI and maximum, mean and minimum temperatures were highly significant (P < 0.01) with coefficients (r) of 0.79, 0.90 and 0.93, respectively. By describing the intra-annual LAI pattern, this study fills a gap in the literature on the phenology of Platanus orientalis L.