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Threads
Kinds of Threads Selected AbstractsSPINNING THREADS: ON PEACOCKE'S MODERATE RATIONALISMANALYTIC PHILOSOPHY, Issue 2 2006Maximilian De Gaynesford First page of article [source] Dysesthesia and Fasciculation: Unusual Complications Following Face-lift with Cog ThreadsDERMATOLOGIC SURGERY, Issue 2 2007CHOONG JAE LEE MD No abstract is available for this article. [source] Effect of Cog Threads under Rat SkinDERMATOLOGIC SURGERY, Issue 12 2005Hyo Jook Jang MD Background. The aging face loses the tensile strength of structural integrity. Cog threads have been used recently to tighten lax skin and soft tissue. Objective. A comparative study of the effects of cog, monofilament, and multifilament threads under rat skin. Methods. Each cog, monofilament, and multifilament thread was inserted under the facial skin of a cadaver and the panniculus carnosus of rat dorsal skin. The maximum holding strength (MHS) of the thread and the tearing strength of the skin around the thread were measured with a tensiometer. The thickness of the capsule around the thread and the myofibroblasts was observed histologically. Results. In the cadaver, the MHS of the cog thread was 190.7 ± 65.6 g. It was greater than that of the monofilament (22.4 ± 7.7 g) or multifilament (40.4 ± 19.7 g) thread. In the rat, the MHS of the cog thread was 95.1 ± 18.8 g. It was greater than that of the monofilament (4.3 ± 1.3 g) or multifilament (10.9 ± 2.1 g) thread in the second week. The thickness of the capsule around the cog thread was 93.0 ± 3.2 ,m. It was thicker than the monofilament thread's capsule, 39.2 ± 12.1 ,m, in the fourth week. The number of myofibroblasts presented significantly more in the cog (96.0 ± 72.4) than in the monofilament thread (4.3 ± 4.4). The rumpled in-between skin suspended by each of the three different threads returned to its original state in 2 weeks. Conclusion. The cog thread placed under the rat skin immediately pulled the skin and subcutaneous tissue. The myofibroblasts around the thread played a role in fibrous tissue contracture 4 weeks postinsertion of the thread. These findings could be the basis for clinical application. THIS STUDY WAS SUPPORTED BY A GRANT FROM THE KOREA HEALTH 21 R&D PROJECT, MINISTRY OF HEALTH AND WELFARE, REPUBLIC OF KOREA. [source] Assembly of Multi-Stranded Nanofiber Threads through AC Electrospinning,ADVANCED MATERIALS, Issue 3 2009Siddharth Maheshwari Multi-stranded threads are fabricated using AC electrospinning. The threads are 1,100,µm thick and are composed of interconnected ,100,nm thick nanofiber strands. The ease of collection due to localization of the whipping instability leads to uncomplicated control and placement of the threads. The network structure has high mechanical integrity and allows for use in fabric weaving, filtration, and biomedical applications. [source] Threads from the labyrinth: therapy with survivors of war and political oppressionJOURNAL OF FAMILY THERAPY, Issue 2 2001Jeremy Woodcock War and political atrocity are endemic, and the denial of what has befallen survivors who become refugees has both therapeutic and human rights dimensions. The work described in this article considers the psychological and political aspects of the suppression of memory and culture and how psychotherapy engages with these processes. Narrative, in its customary form as the creation of stories, is discussed as one of the ways of enabling survivors to be given a voice that allows them to process events of atrocity, displacement and exile. The usefulness of psychoanalytic ideas and their integration with systemic practice is demonstrated. The interplay between difficult psychotherapeutic material, the patient or family and the therapist is shown and the use of supervision noted. The discussion is exemplified with descriptions of therapeutic work with individuals, families and small groups. The thinking that emerges is applicable not only to work with survivors but has general implications for systemic work in general as it struggles with its contemporary identity. [source] Thematic Threads in the Book of the Twelve , Edited by Paul L. Redditt and Aaron SchartRELIGIOUS STUDIES REVIEW, Issue 2 2007Kevin Mellish No abstract is available for this article. [source] Agmatine Signaling: Odds and ThreadsCARDIOVASCULAR THERAPEUTICS, Issue 1 2004Reinhard Berkels ABSTRACT Agmatine is a metabolite of L-arginine. It is formed by the decarboxylation of L-arginine via arginine decarboxylase in bacteria, plants and mammals. It is becoming clear that it has multiple physiological functions as a potential transmitter. Agmatine binds to ,2 -adrenoceptors and to imidazoline binding sites. It blocks NMDA receptors and other ligand-gated cation channels. It also inhibits nitric oxide synthase, induces release of peptide hormones and antizyme and plays a role during cell proliferation by interacting with the generation and transport of polyamines. Although the precise function of endogenously released agmatine is presently still unclear, this review will summarize several aspects concerning the biological function of agmatine. [source] Augmentation of Exposed Implant Threads with Autogenous Bone Chips: Prospective Clinical StudyCLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 4 2000Göran Widmark DDS ABSTRACT Background: Autogenous bone chips can be harvested during drilling of implant sites and may be used as a graft material for bone augmentation and coverage of exposed implant threads. Purpose: The aim of this prospective study was to evaluate the possibility of augmenting exposed implant threads with autogenous bone chips. Materials and Methods: Twenty-one consecutive patients treated with screw-shaped oral implants with exposed threads due to buccal fenestration or marginal defects were augmented with autogenous bone harvested with a bone trap during drilling of the implant site. Both marginal (9 sites) and fenestration defects (12 sites), with 4 to 14 exposed implant threads, were registered clinically and with photography. The number of exposed implant threads was measured before and at second-stage surgery 6 months after augmentation. Results: Complete bone coverage of the exposed implant threads was seen in 12 of the 21 implant sites. Six sites showed one to two remaining exposed threads, two showed about 40% coverage, and one showed flattening of the defect but with eight of nine exposed threads at 6 months follow-up. The mean bone gain was 81% in patients with a marginal defect and 82% in patients with a fenestration defect. Conclusion: The results from this clinical study show that it is possible to gain bone over exposed implant threads by augmentation with autogenous bone chips. Conclusion It is concluded that it is possible to achieve coverage of exposed implant threads by augmentation with autogenous bone chips harvested during drilling of implant sites. [source] Visualizing massively multithreaded applications with ThreadScopeCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 1 2010Kyle B. Wheeler Abstract As highly parallel multicore machines become commonplace, programs must exhibit more concurrency to exploit the available hardware. Many multithreaded programming models already encourage programmers to create hundreds or thousands of short-lived threads that interact in complex ways. Programmers need to be able to analyze, tune, and troubleshoot these large-scale multithreaded programs. To address this problem, we present ThreadScope: a tool for tracing, visualizing, and analyzing massively multithreaded programs. ThreadScope extracts the machine-independent program structure from execution trace data from a variety of tracing tools and displays it as a graph of dependent execution blocks and memory objects, enabling identification of synchronization and structural problems, even if they did not occur in the traced run. It also uses graph-based analysis to identify potential problems. We demonstrate the use of ThreadScope to view program structure, memory access patterns, and synchronization problems in three programming environments and seven applications. Copyright © 2009 John Wiley & Sons, Ltd. [source] Increasing data reuse of sparse algebra codes on simultaneous multithreading architecturesCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 15 2009J. C. Pichel Abstract In this paper the problem of the locality of sparse algebra codes on simultaneous multithreading (SMT) architectures is studied. In these kind of architectures many hardware structures are dynamically shared among the running threads. This puts a lot of stress on the memory hierarchy, and a poor locality, both inter-thread and intra-thread, may become a major bottleneck in the performance of a code. This behavior is even more pronounced when the code is irregular, which is the case of sparse matrix ones. Therefore, techniques that increase the locality of irregular codes on SMT architectures are important to achieve high performance. This paper proposes a data reordering technique specially tuned for these kind of architectures and codes. It is based on a locality model developed by the authors in previous works. The technique has been tested, first, using a simulator of a SMT architecture, and subsequently, on a real architecture as Intel's Hyper-Threading. Important reductions in the number of cache misses have been achieved, even when the number of running threads grows. When applying the locality improvement technique, we also decrease the total execution time and improve the scalability of the code. Copyright © 2009 John Wiley & Sons, Ltd. [source] JAC: declarative Java concurrencyCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 5 2006Max Haustein Abstract The Java programming language has a low-level concurrency model which is hard to use and does not blend well with inheritance. JAC is an extension of Java that introduces a higher level of concurrency, hiding threads and separating thread synchronization from application logic in a declarative fashion. The emphasis is on limiting the differences between sequential and concurrent code, thus furthering code reuse, and on avoiding inheritance anomalies. This is achieved by taking a middle road between concurrent code on the one hand and complete separation of sequential application logic from concurrency mechanisms on the other. An extensive comparison with related approaches is given for motivating our design decisions. Copyright © 2005 John Wiley & Sons, Ltd. [source] A comparison of concurrent programming and cooperative multithreading under load balancing applicationsCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 4 2004Justin T. Maris Abstract Two models of thread execution are the general concurrent programming execution model (CP) and the cooperative multithreading execution model (CM). CP provides nondeterministic thread execution where context switches occur arbitrarily. CM provides threads that execute one at a time until they explicitly choose to yield the processor. This paper focuses on a classic application to reveal the advantages and disadvantages of load balancing during thread execution under CP and CM styles; results from a second classic application were similar. These applications are programmed in two different languages (SR and Dynamic C) on different hardware (standard PCs and embedded system controllers). An SR-like run-time system, DesCaRTeS, was developed to provide interprocess communication for the Dynamic C implementations. This paper compares load balancing and non-load balancing implementations; it also compares CP and CM style implementations. The results show that in cases of very high or very low workloads, load balancing slightly hindered performance; and in cases of moderate workload, both SR and Dynamic C implementations of load balancing generally performed well. Further, for these applications, CM style programs outperform CP style programs in some cases, but the opposite occurs in some other cases. This paper also discusses qualitative tradeoffs between CM style programming and CP style programming for these applications. Copyright © 2004 John Wiley & Sons, Ltd. [source] OpenMP-oriented applications for distributed shared memory architecturesCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 4 2004Ami Marowka Abstract The rapid rise of OpenMP as the preferred parallel programming paradigm for small-to-medium scale parallelism could slow unless OpenMP can show capabilities for becoming the model-of-choice for large scale high-performance parallel computing in the coming decade. The main stumbling block for the adaptation of OpenMP to distributed shared memory (DSM) machines, which are based on architectures like cc-NUMA, stems from the lack of capabilities for data placement among processors and threads for achieving data locality. The absence of such a mechanism causes remote memory accesses and inefficient cache memory use, both of which lead to poor performance. This paper presents a simple software programming approach called copy-inside,copy-back (CC) that exploits the data privatization mechanism of OpenMP for data placement and replacement. This technique enables one to distribute data manually without taking away control and flexibility from the programmer and is thus an alternative to the automat and implicit approaches. Moreover, the CC approach improves on the OpenMP-SPMD style of programming that makes the development process of an OpenMP application more structured and simpler. The CC technique was tested and analyzed using the NAS Parallel Benchmarks on SGI Origin 2000 multiprocessor machines. This study shows that OpenMP improves performance of coarse-grained parallelism, although a fast copy mechanism is essential. Copyright © 2004 John Wiley & Sons, Ltd. [source] SCALEA: a performance analysis tool for parallel programsCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 11-12 2003Hong-Linh Truong Abstract Many existing performance analysis tools lack the flexibility to control instrumentation and performance measurement for code regions and performance metrics of interest. Performance analysis is commonly restricted to single experiments. In this paper we present SCALEA, which is a performance instrumentation, measurement, analysis, and visualization tool for parallel programs that supports post-mortem performance analysis. SCALEA currently focuses on performance analysis for OpenMP, MPI, HPF, and mixed parallel programs. It computes a variety of performance metrics based on a novel classification of overhead. SCALEA also supports multi-experiment performance analysis that allows one to compare and to evaluate the performance outcome of several experiments. A highly flexible instrumentation and measurement system is provided which can be controlled by command-line options and program directives. SCALEA can be interfaced by external tools through the provision of a full Fortran90 OpenMP/MPI/HPF frontend that allows one to instrument an abstract syntax tree at a very high-level with C-function calls and to generate source code. A graphical user interface is provided to view a large variety of performance metrics at the level of arbitrary code regions, threads, processes, and computational nodes for single- and multi-experiment performance analysis. Copyright © 2003 John Wiley & Sons, Ltd. [source] Sapphire: copying garbage collection without stopping the worldCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 3-5 2003Richard L. Hudson Abstract The growing use in concurrent systems of languages that require garbage collection (GC), such as Java, is raising practical interest in concurrent GC. Sapphire is a new algorithm for concurrent copying GC for Java. It stresses minimizing the amount of time any given application thread may need to block to support the collector. In particular, Sapphire is intended to work well in the presence of a large number of application threads, on small- to medium-scale shared memory multiprocessors. Sapphire extends previous concurrent copying algorithms, and is most closely related to replicating copying collection, a GC technique in which application threads observe and update primarily the old copies of objects. The key innovations of Sapphire are: (1) the ability to ,flip' one thread at a time (changing the thread's view from the old copies of objects to the new copies), as opposed to needing to stop all threads and flip them at the same time; (2) exploiting Java semantics and assuming any data races occur on volatile fields, to avoid a barrier on reads of non-volatile fields; and (3) working in concert with virtually any underlying (non-concurrent) copying collection algorithm. Copyright © 2003 John Wiley & Sons, Ltd. [source] Lesser Bear: A lightweight process library for SMP computers,scheduling mechanism without a lock operationCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 10 2002Hisashi Oguma Abstract We have designed and implemented a lightweight process (thread) library called ,Lesser Bear' for SMP computers. Lesser Bear has thread-level parallelism and high portability. Lesser Bear executes threads in parallel by creating UNIX processes as virtual processors and a memory-mapped file as a huge shared-memory space. To schedule thread in parallel, the shared-memory space has been divided into working spaces for each virtual processor, and a ready queue has been distributed. However the previous version of Lesser Bear sometimes requires a lock operation for dequeueing. We therefore proposed a scheduling mechanism that does not require a lock operation. To achieve this, each divided space forms a link topology through the queues, and we use a lock-free algorithm for the queue operation. This mechanism is applied to Lesser Bear and evaluated by experimental results. Copyright © 2002 John Wiley & Sons, Ltd. [source] Effect of Cog Threads under Rat SkinDERMATOLOGIC SURGERY, Issue 12 2005Hyo Jook Jang MD Background. The aging face loses the tensile strength of structural integrity. Cog threads have been used recently to tighten lax skin and soft tissue. Objective. A comparative study of the effects of cog, monofilament, and multifilament threads under rat skin. Methods. Each cog, monofilament, and multifilament thread was inserted under the facial skin of a cadaver and the panniculus carnosus of rat dorsal skin. The maximum holding strength (MHS) of the thread and the tearing strength of the skin around the thread were measured with a tensiometer. The thickness of the capsule around the thread and the myofibroblasts was observed histologically. Results. In the cadaver, the MHS of the cog thread was 190.7 ± 65.6 g. It was greater than that of the monofilament (22.4 ± 7.7 g) or multifilament (40.4 ± 19.7 g) thread. In the rat, the MHS of the cog thread was 95.1 ± 18.8 g. It was greater than that of the monofilament (4.3 ± 1.3 g) or multifilament (10.9 ± 2.1 g) thread in the second week. The thickness of the capsule around the cog thread was 93.0 ± 3.2 ,m. It was thicker than the monofilament thread's capsule, 39.2 ± 12.1 ,m, in the fourth week. The number of myofibroblasts presented significantly more in the cog (96.0 ± 72.4) than in the monofilament thread (4.3 ± 4.4). The rumpled in-between skin suspended by each of the three different threads returned to its original state in 2 weeks. Conclusion. The cog thread placed under the rat skin immediately pulled the skin and subcutaneous tissue. The myofibroblasts around the thread played a role in fibrous tissue contracture 4 weeks postinsertion of the thread. These findings could be the basis for clinical application. THIS STUDY WAS SUPPORTED BY A GRANT FROM THE KOREA HEALTH 21 R&D PROJECT, MINISTRY OF HEALTH AND WELFARE, REPUBLIC OF KOREA. [source] A Case of Aptos Thread Migration and Partial ExpulsionDERMATOLOGIC SURGERY, Issue 3 2005José G. Silva-Siwady MD Background In our practice, the use of dented polypropylene suture has become a very simple, conservative, and effective procedure for lifting flabby ptosed facial tissue, improving it without surgery. As with some cosmetic procedures, we have seen complications with this technique. Objective To present a case report of migration and partial expulsion of Aptos thread (TOTAL Charm, Moscow, Russia). Methods After successful fixation of facial tissue with 10 Aptos threads (5 on each side, 3 in the upper and central cheek, and 2 in the mandibular area), the patient returned 28 days later owing to migration and partial expulsion of one of the Aptos threads. Results The expulsed thread was easily removed, and the patient was treated with antibiotic therapy without further complications. Conclusion After this experience, we can conclude that Aptos threads are an additional tool in our arsenal for the treatment of facial aging. We must be especially cautious and aware that our patients can present with previously unknown complications secondary to newly described procedures, as with this recent technique. JOSé G. SILVA-SIWADY, MD, CELINA DÍAZ-GARZA, AND JORGE OCAMPO-CANDIANI, MD, HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS. [source] Development and fine structure of the yolk nucleus of previtellogenic oocytes in the medaka Oryzias latipesDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 6 2000Hirokuni Kobayashi The development and fine structure of yolk nuclei in the cytoplasm of previtellogenic oocytes were examined by electron microscopy during several stages of oogenesis in the medaka, Oryzias latipes. Shortly after oogenesis starts, oocytes 20,30 ,m in diameter have much electron-dense (basophilic) cytoplasm, within which a continuous or discontinuous, irregular ring-shaped lower electron-dense area of flocculent appearance (LF) begins to emerge around the nucleus. The yolk nucleus is first recognized within an LF area as a few fragments of dense granular thread measuring 20,25 nm in width. The threads consist of two rows of very dense granules resembling ribosomes or ribonucleoprotein (RNP)-like particles in size and electron density. These thread-like fragments gradually increase in number and length until they assemble into a compact, spherical mass of complicated networks. Analysis of serial sections suggests that the yolk nucleus is a complicated mass of numerous, small deformed vacuoles composed of a single lamella with double layers of ribosomes or RNP-like granules, rather than a mass of granular threads. When oocytes develop to greater than 100 ,m in diameter, the yolk nucleus begins to fragment before dispersing throughout the surrounding cytoplasm, concomitantly with the disappearance of LF areas. At this stage of oogenesis, a restricted region of the granulosa cell layer adjacent to the yolk nucleus becomes somewhat columnar in morphology, fixing the vegetal pole region of the oocyte. [source] Organic litter: dominance over stones as a source of interrill flow roughness on low-gradient desert slopes at Fowlers Gap, arid western NSW, AustraliaEARTH SURFACE PROCESSES AND LANDFORMS, Issue 1 2003David Dunkerley Abstract Thirty-six runoff plot experiments provide data on flow depths, speeds, and Darcy,Weisbach friction coefficients (f) on bare soil surfaces, and surfaces to which were added sufficient extra plant litter or surface stones to provide projected cover of 5, 10 and 20 per cent. Precision flow depth data were derived with a computer-controlled gantry and needle gauge for two different discharges for each plot treatment. Taking a fixed flow intensity (Reynolds number, Re = 150) for purposes of comparison shows means of f = 17·7 for bare soil surfaces, f = 11·4 for added stone treatments, and f = 23·8 for added litter treatments. Many individual values of f for stone treatments are lower than for the bare soil surface, but all litter treatments show increases in fcompared to bare soil. The lowering of f in stone treatments relates to the submerged volume that the stones occupied, and the associated concentration of flow onto a smaller part of the plot surface. This leads to locally higher flow intensities and lower frictional drag along threads of flow that the obstacles create. Litter causes higher frictional drag because the particles are smaller, and, for the same cover fraction, are 100 times more numerous and provide 20 times the edge or perimeter length. Along these edges, which in total exceed 2·5 m g,1 (equivalent to 500 m m,2 for a loading of 2 t ha,1), surface tension draws up water from between the litter particles. This reduces flow depth there, and as a consequence of the lower flow intensity, frictional drag rises. Furthermore, no clear passage remains for the establishment of flow threads. These findings apply to shallow interrill flows in which litter is largely immobile. The key new result from these experiments is that under these conditions, a 20 per cent cover of organic litter can generate interrill frictional retardation that exceeds by nearly 41 per cent that of a bare soil surface, and twice that contributed by the same cover fraction of surface stones. Even greater dominance by litter can be anticipated at the many dryland sites where litter covers exceed those tested here. Copyright © 2002 John Wiley & Sons, Ltd. [source] Spatial analysis of an invasion front of Acer platanoides: dynamic inferences from static dataECOGRAPHY, Issue 3 2005Wei Fang It is an open question whether the invading tree species Acer platanoides is invading and displacing native trees within pre-existing forest stands, or merely preferentially occupying new stands of secondary forest growth at the edges of existing forests. Several threads of spatial pattern analyses were used to assess the invasibility of A. platanoides, and to link the invasion to the structure of a plant community in the deciduous forest of the northeastern United States. The analyses were based on maps of a contiguous 100×50 m area along an A. platanoides infestation gradient. The distribution of A. platanoides was highly aggregated and the population importance value increased from 28.1 to 38.5% according to mortality estimated from standing dead trees, while the distribution of native tree species was close to random and importance value of Quercus spp. decreased from 33.4 to 26.9% over time. The size distributions of each tree species across distance indicated that A. platanoides was progressively invading the interior of the forest while the native species (including A. rubrum) were not spreading back towards the A. platanoides monospecific patch. The null hypothesis of no invasibility was rejected based on quantile regressions. There were negative correlations between A. platanoides density and the densities of native species in different functional groups, and negative correlation of A. platanoides density and the species diversity in forest understory. The null hypothesis that A. platanoides invasion did not suppress native trees or understory was rejected based on Dutilleul's modified t-test for correlation, consistent with experimental results in the same study site. The combination of multiple spatial analyses of static data can be used to infer historical dynamical processes that shape a plant community structure. The concept of "envelop effects" was discussed and further developed. [source] A comparison of the host-searching efficiency of two larval parasitoids of Plutella xylostellaECOLOGICAL ENTOMOLOGY, Issue 1 2002Xin-Geng Wang Summary 1. A host specialist parasitoid is thought to have greater efficiency in locating hosts or greater ability to overcome host defence than a generalist species. This leads to the prediction that a specialist should locate and parasitise more hosts than a generalist in a given arena. The work reported here tested these predictions by comparing the host-searching behaviour of Diadegma semiclausum (a specialist) and Cotesia plutellae (an oligophagous species), two parasitoids of larval Plutella xylostella. 2. Both parasitoids employed antennal search and ovipositor search when seeking hosts but D. semiclausum also seemed to use visual perception in the immediate vicinity of hosts. 3. Larvae of P. xylostella avoided detection by parasitoids by moving away from damaged plant parts after short feeding bouts. When they encountered parasitoids, the larvae wriggled vigorously as they retreated and often hung from silk threads after dropping from a plant. 4. These two parasitoids differed in their responses to host defences. Diadegma semiclausum displayed a wide-area search around feeding damage and waited near the silk thread for a suspended host to climb up to the leaf, then attacked it again. Cotesia plutellae displayed an area-restricted search and usually pursued the host down the silk thread onto the ground. 5. Diadegma semiclausum showed a relatively fixed behavioural pattern leading to oviposition but C. plutellae exhibited a more plastic behavioural pattern. 6. The time spent by the two parasitoids on different plants increased with increasing host density, but the time spent either on all plants or a single plant by D. semiclausum was longer than that of C. plutellae. Diadegma semiclausum visited individual plants more frequently than C. plutellae before it left the patch, and stung hosts at more than twice the rate of C. plutellae. 7. The results indicated that the host-location strategies employed by D. semiclausum were adapted better to the host's defensive behaviour, and thus it was more effective at detecting and parasitising the host than was C. plutellae. [source] Does the Giant Wood Spider Nephila pilipes Respond to Prey Variation by Altering Web or Silk Properties?ETHOLOGY, Issue 4 2007I-Min Tso Recent studies demonstrated that orb-weaving spiders may alter web architectures, the amount of silk in webs, or the protein composition of silks in response to variation in amount or type of prey. In this study, we conducted food manipulations to examine three mechanisms by which orb-weaving spiders may adjust the performance of webs to variation in prey by altering the architectures of webs, making structural changes to the diameters of silk threads, and manipulating the material properties or amino acid composition of silk fibers. We fed Nephila pilipes two different types of prey, crickets or flies, and then compared orb structure and the chemical and physical properties of major ampullate (MA) silk between groups. Prey type did not affect orb structures in N. pilipes, except for mesh size. However, MA silk diameter and the stiffness of orbs constructed by spiders fed crickets were significantly greater than for the fly group. MA fibers forcibly silked from N. pilipes fed crickets was significantly thicker, but less stiff, than silk from spiders fed flies. Spiders in the cricket treatment also produced MA silk with slightly, but statistically significantly, more serine than silk from spiders in the fly treatment. Percentages of other major amino acids (proline, glycine, and glutamine) did not differ between treatments. This study demonstrated that orb-weaving spiders can simultaneously alter some structural and material properties of MA silk, as well as the physical characteristics of webs, in response to different types of prey. [source] Pseudorotaxanes and Rotaxanes Incorporating Diarylcycloheptatriene StationsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 2 2005Werner Abraham Abstract The nature of the interaction between the tetracationic cyclophane cyclobis(paraquat-4,4,-biphenylene) and molecular threads incorporating arylcycloheptatriene units as stations was studied through the differences between the proton resonances observed in the NMR spectra of free molecular threads and in those of corresponding pseudorotaxanes and rotaxanes (CIS values). Molecular threads of different lengths possessing one or two recognition stations and incorporating two different isomeric arylcycloheptatriene units were used for pseudorotaxanes and rotaxanes. The main contribution to the driving forces behind the complexation of pseudorotaxanes and the co-conformation of rotaxanes was deduced from the CIS values of distinct parts of the molecular threads. The unusual signal dispersion of the cyclophane proton resonances is attributed to the asymmetry caused by the molecular thread incorporating the asymmetric cycloheptatriene ring. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Exploring the Challenges of Climate Science Literacy: Lessons from Students, Teachers and Lifelong LearnersGEOGRAPHY COMPASS (ELECTRONIC), Issue 9 2010Lesley-Ann L. Dupigny-Giroux Today more than ever, being climate literate is a critical skill and knowledge area that influences our interaction with the environment around us, our understanding of scientific news and the daily decisions that we make. Yet, the term climate literacy can be misunderstood, as are the terms weather, climate and climate variability. This article surveys the existing literature and highlights six challenges to achieving a climate literate citizenry in both formal and informal or lifelong learning. The lessons learned from high school and undergraduate students, teachers and lifelong learners, many of whom are retired, serve as the threads which are woven into a tapestry of strategies for embedding climate science principles across entire school curricula as well as society at large. [source] Oral health and oral implant status in edentulous patients with implant-supported dental prostheses who are receiving long-term nursing careGERODONTOLOGY, Issue 4 2009Rita Isaksson Aim:, The aim of this study was to investigate oral health and oral implant status in a group of edentulous patients receiving long-term residential or nursing care (LTC), all of whom had implant-supported fixed or removable dental prostheses. Material and methods:, A dental examination was performed on a total of 3310 patients receiving LTC and from this population 35 edentulous patients in whom dental implants had been placed formed the cohort for this study. All examinations were performed by a specialist in hospital dentistry and took place in the patients' own home environment. Oral health was assessed by means of a protocol which evaluated oral hygiene status, possible oral mucosal inflammation and oral mucosal friction levels. Any problems with the implant-supported prosthesis, implant mobility or other complications were also assessed. In addition, patients were asked about any oral symptoms and their usual oral hygiene procedures. Results:, About half of the subjects (17/35) were registered as having no/mild inflammation with 18 of 35 having moderate/severe inflammation. Twelve of the 35 patients had good/acceptable oral hygiene and 23 of 35 had poor/bad oral hygiene. Twenty-one of the 35 patients depended on help from the nursing personnel for their daily oral hygiene procedures. Obvious problems with food impaction were noted in 11 patients. A total of 229 implants had been placed in 43 jaws supporting 40 full arch-fixed prostheses and three implant-borne overdentures. There was no evidence of mobility or fractures of either the implants or the prostheses. Fifteen implants showed some exposed screw threads. Pus was exuding from one implant site and general peri-implant gingival hyperplasia was noted in two patients. Twenty-four patients were completely satisfied with the function and appearance of their implant-supported prostheses. Two patients were totally dissatisfied. Conclusion:, This study indicates that oral implant therapy can be considered as a treatment of choice in elderly patients, even if oral hygiene is sub-optimal. [source] Waiter, There's a Fly in My Soup!HYPATIA, Issue 3 2004Reflections on the Philosophical Gourmet Report Editor's note: with this essay, Hypatia inaugurates a new column. We welcome musings on the state of the profession, the life of the independent scholar, political activism, teaching, publishing, or other topics of interest to feminist philosophers. We particularly invite submissions that pick up conversational threads begun by earlier contributions to the column, so that Musings becomes a forum for talking to one another. If you have an idea for the column, please tell us about it. [source] Environmental conditions impinge on dragline silk protein compositionINSECT MOLECULAR BIOLOGY, Issue 5 2008K.-H. Guehrs Abstract The silk formed in the major ampullate (MA) gland of the orb weaving spider Nephila clavipes is composed of two silk fibroins, which are called major ampullate spidroins 1 (MaSp1) and 2 (MaSp2). Analysis of proteolytic peptides and reactivity to spidroin type specific antibodies indicated that MaSp2 constituted only a minor part in the spinning dope as well as in the spun filaments. Upon starvation, a change in the silk's characteristic features was observed that was concomitant of a decrease in the contribution of MaSp2. The silk became less elastic and stiffer, which will better tailor its usability for the safety line, albeit at the expense of its employment as the web frame threads. In addition, since MaSp2 production requires greater ATP consumption, such a shift in the protein ratio cuts down on the energy costs to produce the silk. From this change in protein composition the spider might therefore benefit twice, by synthesizing ,cheaper' silk that into the bargain has properties that potentially can better support foraging in times of food shortage. [source] How Nature Modulates a Fiber's Mechanical Properties: Mechanically Distinct Fibers Drawn from Natural Mesogenic Block Copolymer VariantsADVANCED MATERIALS, Issue 4 2009Matthew J. Harrington Mussel byssal threads are functionally graded biological fibers adapted for tethering the soft tissue of the organism (,1 MPa) to hard surfaces !(25 GPa) in the rocky seashore. A stiffness gradient mitigates contact deformation and is defined by an incrementally regulated distribution of two protein block copolymer variants with stiff and pliable domains, respectively. [source] Assembly of Multi-Stranded Nanofiber Threads through AC Electrospinning,ADVANCED MATERIALS, Issue 3 2009Siddharth Maheshwari Multi-stranded threads are fabricated using AC electrospinning. The threads are 1,100,µm thick and are composed of interconnected ,100,nm thick nanofiber strands. The ease of collection due to localization of the whipping instability leads to uncomplicated control and placement of the threads. The network structure has high mechanical integrity and allows for use in fabric weaving, filtration, and biomedical applications. 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