541 research outputs found
The implications of grassland and heathland management for the conservation of spider communities: a review
No full textBoth intensity and type of habitat management in grasslands and heathlands affect spider communities. With high intensity management, spider communities often lack diversity and are dominated by a few r-selected species affiliated with bare ground. Low intensity management produces more complex communities introducing more niches for aerial web spinners and climbing spiders. The preferred management will be site-dependent and may not be appropriate for all spiders in all situations, particularly for some rare or threatened species. Providing natural cover is recommended when using extreme forms of management or intensive grazing (particularly by sheep). In extreme cases, or where trampling is heavy, the litter layer should be conserved. We advocate research and survey before and after major management implementation. Habitat management for spiders should not be considered alone, but integrated into a holistic plan. Management for spiders may conflict with rare plant conservation and small reserves should examine the viability of providing two contrasting regimes
Spider communities as tools in monitoring reclaimed limestone quarry landforms
No full textSpider communities are sensitive to a wide range of environmental factors and are potential ecological indicators which may be effective in the assessment and monitoring of restored ecosystems. One restoration technique of disused limestone quarry faces, landform replication, attempts to create landforms and ecosystems similar to those found on natural dalesides. Vegetation surveys indicate that communities developing on landform replications are more closely allied to natural dalesides than are those of naturally recolonised disused quarries. Assessment of the spider communities of three landform replication sites, a natural limestone daleside and seven naturally recolonised disused limestone quarries, using DECORANA and TWINSPAN, produced differing patterns of sites than those observed through the assessment of the vegetation communities. DECORANA assessment based on vascular plant species composition highlights the similarities between daleside and reclaimed site communities. The sensitivity of spider communities to vegetation structure and extent of bare ground highlights differences between sites and provides evidence of important differences in vegetation community development particularly in relation to cover and structure. Implications for the assessment of reclamation and restoration techniques are discussed
Retinitis Pigmentosa GTPase Regulator (RPGR) protein isoforms in mammalian retina:insights into X-linked Retinitis Pigmentosa and associated ciliopathies
No full textMutations in the cilia-centrosomal protein Retinitis Pigmentosa GTPase Regulator (RPGR) are a frequent cause of retinal degeneration. The RPGR gene undergoes complex alternative splicing and encodes multiple protein isoforms. To elucidate the function of major RPGR isoforms (RPGR 1-19 and RPGR ORF15), we have generated isoform-specific antibodies and examined their expression and localization in the retina. Using sucrose-gradient centrifugation, immunofluorescence and co-immunoprecipitation methods, we show that RPGR isoforms localize to distinct sub-cellular compartments in mammalian photoreceptors and associate with a number of cilia-centrosomal proteins. The RCC1-like domain of RPGR, which is present in all major RPGR isoforms, is sufficient to target it to the cilia and centrosomes in cultured cells. Our findings indicate that multiple isotypes of RPGR may perform overlapping yet somewhat distinct transport-related functions in photoreceptors
Author Correction: The future of Blue Carbon science
No full textCorrection to: Nature Communications https://doi.org/10.1038/s41467-019-11693-w, published online 05 September 2019.
The original version of this Article contained an error in the author affiliations.
Affiliation 24 incorrectly read ‘School of Applied Sciences, Edinburgh University, Edinburgh EH11 4BN, UK’
This has now been corrected in both the PDF and HTML versions of the Article.Full Tex
Measurement of torsional rigidity of the machine elements with use of holographic interferometry
No full textW wielu konstrukcjach mechanicznych występują elementy poddane skręcaniu. Powyższe elementy powinny charakteryzować się odpowiednią wartością sztywności skrętnej. Sztywność ta może być określona na podstawie pomiaru kąta skręcenia pręta w funkcji momentu skręcającego. Szczególne trudności występują w przypadku pręta o przekroju niekołowym. W powyższym artykule określono sztywność skrętną elementów maszyn. Oceny tej sztywności dokonano na podstawie pomiaru przemieszczeń pręta skręcanego o przekroju kwadratowym przy użyciu interferometrii holograficznej. Wyznaczono współczynnik sztywności skrętnej pręta zdefiniowany przez autora.Elements subjected to torsion in many mechanical construction are occurred. The elements should be characterized by adequate value of stiffness of torsional rigidity. This stiffness can be determined by the measurement of the rod torsion angle vs. torsion moment function. The particular difficulty appears when the rod section is non-circular. The estimation of the torsional rigidity of machine elements is presented in the paper. The rigidity estimation is based on the displacement measurement of the rod of square section subjected to torsion and bending. The measurements are made by the use of holographic interferometry. The scheme of test stand is shown in Fig. 1. The investigated object is presented in Fig. 2. Based on interferometry striae shown in Fig.3. the coefficient ? according to the Saint Venant introduction is determined. In this paper there are presented two methods for determining this coefficient. In the first method the coefficient ? based on measurement of angle of the rod is determined. In the second method the bending line of beam is as-sumed. Finally the equivalent of torsional rigidity Kz defined by the author is presented
Pseudoscorpions in Field Margins: Effects of Margin Age, Management and Boundary Habitats
No full textVolume: 27Start Page: 236End Page: 24
Rod-and-cable systems of retractable roofings of small sports venues
No full textPowstaje coraz więcej niewielkich obiektów sportowych przeznaczonych dla popularnego uprawiania tenisa, siatkówki, czy piłki nożnej. Chętnie są one rozgrywane na wolnym powietrzu, ale w naszym klimacie niezbędne jest też zapewnienie okresowej izolacji od warunków zewnętrznych zarówno w okresie zimy, jak i w upalne letnie dni. Takie sprzeczne wymagania spełnić mogą tylko obiekty z częściowo lub całkowicie składanymi konstrukcjami przekryć i ścian zewnętrznych. Szczególnie przydatne do realizacji takich urządzeń wydają się być lekkie systemy prętowo-cięgnowe. Autor przytacza przykłady historycznych i współczesnych realizacji i projektów tego typu, poszukując rozwiązań możliwych do zastosowania w konstrukcjach małych składanych przekryć.More and more small sports venues are being created, for the purpose of playing tennis, volleyball or football (soccer). The aforementioned sports are often connected with an outdoor setting, however in the Polish climatic conditions, it is required that a periodic isolation from the weather factors is available, both during the winter, as well as during the hot days of summer. This forms a set of contradictory requirements, which may only be met by facilities with partially and fully retractable roof/external wall solutions. Rod-and-Cable systems seem to be especially well suited for implementation of such designs. The author discusses the historical and contemporary structures and designs of this type, striving to find solutions that may be feasible in case of the structures of small size
The specificity of heavy oil production from ,,Lubaczów" reservoir
No full textW artykule przedstawiono propozycję wyboru metody eksploatacji ropy ciężkiej (asfaltowej) ze złoża "Lubaczów". Wyboru tego dokonano, biorąc pod uwagę własności fizykochemiczne i ich zmiany uzależnione od temperatury oraz własności geologiczno złożowe. Do wydobywania tej ropy proponuje się zastosowanie pomp wgłębnych żerdziowych z odpowiednią ich modyfikacją lub wgłębnych pomp śrubowych.The proposal of choice of the heavy oil production method from ,,Lubaczów" reservoir is presented in article. This selection was made with regards of oil physicochemical properties and their change with temperature and geological properties of reservoir. Author proposes to heavy oil production the use of rod modified pumps or screw pumps
Providing students with formative audio feedback
No full textThe provision of timely and constructive feedback is increasingly challenging for busy academics. Ensuring effective student engagement with feedback is equally difficult. Increasingly, studies have explored provision of audio recorded feedback to enhance effectiveness and engagement with feedback. Few, if any, of these focus on purely formative audio feedback on draft submissions of written assignments. This study encouraged a cohort of 40 students to submit drafts of written assignments, two weeks before formal submission, in order to receive audio recorded feedback. Nearly half the cohort either did not submit drafts or submitted only brief outlines. The level of draft completeness impacted on the characteristics of the lecturer's feedback. While students receiving audio feedback gained significantly higher marks for finished work, this cannot be directly attributed to receipt/use of feedback as analysis suggests generally more able students are more likely to submit more complete drafts, which leads us to ask the question, are we simply helping better students to perform even better? Audio feedback was reported as clear, engaging and helpful; however, timing of feedback (before formal submission) may be of greater importance in terms of impact on attainment than the audio format. We suggest a model that focuses efforts on formative feedback (in advance of formal submission) and selective provision of summative feedback (targeted feed forward). © 2013 G. Scott, The Higher Education Academy
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