Nestmate recognition in the unicolonial ant Formica paralugubris

In unicolonial populations of ants, individuals can mix freelywithin large networks of nests that contain many queens. Ithas been proposed that the absence of aggression in unicolonialpopulations stems from a loss of nest mate recognition, butfew studies have tested this hypothesis. We investigated patternsof aggression and nest mate recognition in the unicolonial woodant, Formica paralugubris. Little aggression occurred, evenbetween workers from nests separated by up to 5 km. However,when aggression took place, it was directed toward non–nestmates rather than nest mates. Trophallaxis (exchange of liquidfood) occurred very frequently, and surprisingly, workers performedsignificantly more trophallaxis with non–nest mates thanwith nest mates (bias 2.4:1). Hence, workers are able to discriminatenest mates from non–nest mates. Higher rates of trophallaxisbetween non–nest mates may serve to homogenize the colonyodor or may be an appeasement mechanism. Trophallaxis rate andaggression level were not correlated with geographical distanceand did not differ within and between two populations separatedby several kilometers. Hence, these populations do not representdifferentiated supercolonies with clear-cut behavioral boundaries.Overall, the data demonstrate that unicoloniality can evolvedespite well-developed nest mate recognition. Reduced levelsof aggression might have been favored by the low rate of interactionswith foreign workers, high cost of erroneously rejecting nestmates, and low cost of accepting foreign workers.     

Investigation of the visual cytoscreening of conventional gynecologic smears. II. Analysis of eye movement

The perception of visual information in cytoscreening was studied: eye movements were recorded while the cytotechnologist was screening cervical smears by means of a projection screen. Four phases of eye movement could be distinguished: small, aimless movements during the stage movement; a latency period with a duration of about 180 milliseconds; saccadic movement to the position of an object; and fixation on an object. These components explain the two-phase behavior of cytoscreening found in our previous investigations of the stage movement. Visual perception during the period of latency was found to be the most important since only those objects that are recognized by peripheral vision during this period can trigger the necessary saccadic movement before fixation takes place. The scanpath of search in the stationary field of view is determined by the conspicuousness of the objects; the main features of conspicuousness are size and contrast. Even with the comparatively small fields of view (24 degrees and 29 degrees in diameter) used in these experiments, it was found that the detection threshold of peripheral vision increases towards the margin of the field of view. This raises the question of whether the use of large-field binoculars (with 40-degree visual angles) may cause higher false-negative rates for samples with only a few atypical cells.     

Transcranial sonography for diagnosis of Parkinson's disease

Background  

In idiopathic Parkinson's disease (IPD) transcranial sonography (TCS) represents an alternative diagnostic method to verify clinical diagnosis. Although the phenomenon of an increased echogenicity of the Substantia nigra (SN) is well known this method is still not widly used in the diagnostic workup. Until now reliability of this method is still a matter of debate, partly because data only existed from a few laboratories using the same ultrasound machine. Therefore our study was conducted to test the reliability of this method by using a different ultrasound device and examining a large population of control and IPD subjects by two examiners to calculate interobserver reliability.     

Structural features of an acidic polysaccharide from the mucin of Drosera binata

The polysaccharide from the mucin secreted by the leaves of Drosera binata is composed of l-arabinose, d-xylose, d-galactose, d-man     

Cost versus environment? Combined life cycle,techno-economic,and circularity assessment of silicon- and perovskite-based photovoltaic systems

Photovoltaics will play a key role in future energy systems, but their full potential may not be realized until their life cycles are optimized for circularity and overall sustainability. Methods that quantify flows of compound and minor element mixtures, rather than non-mixed elemental flows, are needed to prospectively analyze and predict inventory and performance for complex technology life cycles. This study utilizes process simulation to resolve the mass and energy balances needed to rigorously analyze these complexities in circular systems. Using physics-based prospective inventory data, we simultaneously assess the environmental and techno-economic performance of three photovoltaic life cycles and predict the effects of circularity on resource efficiency, carbon footprint, and levelized cost of electricity. One inventory dataset is generated per life cycle to ensure alignment between assessments and to identify trade-offs between environmental and techno-economic performance with respect to circularity, so linking circularity and sustainability. The linked material and energy resource and techno-economic models allow for the impacts of carbon taxation and the moderating effects of circularity to be explored. In addition to the clear environmental benefits of increased circularity, we find that it could dampen the cost impact of taxation. While confirming that perovskite-based modules, single junction or in tandem with silicon, clearly outperform the silicon market standard both techno-economically and environmentally, we show that maximum circularity does not automatically deliver the most sustainable outcome. The approach enables assessment of the combined impacts of specific technological, commercial, and policy choices made by different actors along the photovoltaic value chain. This article met the requirements for a gold–gold JIE data openness badge described at http://jie.click/badges .      

Fossil round karren from Cyprus: a latest Miocene record of a humid-temperate climate in the eastern Mediterranean

Round karren represent a typical karst landform in humid regions. Since they only form beneath organic-rich soil and become rapidly destroyed after exhumation, their preservation potential in the geological record is, however, low. Herein, we describe pristine fossil round karren from a late Messinian karrenfeld that is incised into a fault scarp at the northwestern margin of the Polis Graben in NW Cyprus (Eastern Mediterranean Sea). The karren indicate that humid temperate climate conditions with at least seasonal rainfalls and vegetation which decomposed into acid humus occurred at the end of the Messinian salinity crisis on Cyprus. Rapid drowning due to the Zanclean transgression ceased karstification at the Miocene–Pliocene boundary and preserved the original round karren morphology.     

Mass spectrometric identification of the pentasialoganglioside GP1c of embryonic chicken brain

Gangliosides were extracted from 11-day-old chicken embryos and finally purified by chromatography on high performance thin-layer plates. Four fractions migrating more slowly than ganglioside GQ1b were obtained by preparative thin-layer chromatography. With the aid of negative ion fast atom bombardment mass spectrometry, one of these could be identified as GP1c.     

Nature and biosynthesis of sialic acids in the starfish Asterias rubens. Identification of sialo-oligomers and detection of S-adenosyl-L-methionine: N-acylneuraminate 8-O-methyltransferase and CMP-N-acetylneuraminate monooxygenase activities.

Mass spectrometric and NMR spectroscopic analyses of bound sialic acids from the starfish Asterias rubens revealed the presence of N-acetylneuraminic acid (4%), N-acetyl-8-O-methylneuraminic acid (12%), N-acetyl-9-O-acetyl-8-O-methylneuraminic acid (less than 1%), N-glycoloylneuraminic acid (19%), N-glycoloyl-8-O-methylneuraminic acid (47%), and N-glycoloyl-9-O-acetyl-8-O-methylneuraminic acid (18%). Analysis of sialo-oligomeric material, obtained after mild acid hydrolysis, demonstrated that N-glycoloyl-8-O-methylneuraminic acid can occur as di- and tri-oligomers, linked through the anomeric center and the N-glycoloyl moiety, Neu5Gc8Me-alpha(2----O5)-Neu5Gc8Me and Neu5Gc8Me-alpha(2----O5)-Neu5Gc8Me-alpha (2----O5)-Neu5Gc8Me. Studies on the biosynthesis of N-acyl-8-O-methylneuraminic acid in A rubens, using the tracer S-adenosyl-L-[methyl-14C]methionine, showed that N-acylneuraminate 8-O-methyltransferase activity was present predominantly in the membrane fraction. CMP-N-acetylneuraminic acid monooxygenase activity was found in the soluble protein fraction, in agreement with investigations on the corresponding vertebrate enzyme.