Variation In Extension Research Articles

Quantification of time-dependent deterioration in mechanical property and ballistic performance through Cunniff Number of poly (p-phenylene terephthalamide) fibers under UV irradiation

Poly (p-phenylene terephthalamide) fibers, a crucial constituent of soft body armor, experience significant deterioration in mechanical and ballistic performance due to UV exposure. However, photo-degradation by UV radiation involves complex chemical reactions and the difficulty in estimating the extent of damage that restricts the development of the predictive aging models or kinetics in such fibrous materials. Hence in this work, the photo-degradation kinetics of poly (p-phenylene terephthalamide) or KF-fibers is quantified by correlating the degradation behavior of different properties with time, thereby assessing the useful performance span of the UV-aged (UV-KF) fibers. The experimental trends indicate three stages of deterioration of any property (modulus, extension at break, Cunniff Number and crystallinity), i.e., an exponential decline followed by an increase over a short duration and finally, a steady and continuous drop. The suitable performance period of UV-aged fibers is estimated based on the initial two stages and presented as ‘favorable property region’ or ‘FPR-zone.’ Changes in V50 ballistic limit, theoretically derived from Cunniff Number, are also estimated, which show a good agreement with the literature data. It reveals that the energy absorption capacity of UV-KF fibers corresponds to initial two years as a span of considerable ballistic protection before continuing to function at 50% of its original protection level for lower aging temperatures. Besides, the apparent activation energy for all the studied properties is correlated to the microstructural and physico-chemical aspects. It indicates that relative changes in molar mass by bond scission/rearrangement and alterations in crystallinity are proportionally related to the degree of variation in modulus and extension at break, thus affecting the wave-velocities in terms of Cunniff Number. The proposed degradation model further can be extended to determine the rate of degradation and lifetime of various ballistic materials under other environmental conditions.

A drain extended FinFET with enhanced DC/RF performance for high-voltage RF applications

A drain-extended fin field-effect transistor (FinFET) with a dual material gate (DMG) and a high-k field plate (FP), named DF-DeFF, is proposed for high-voltage radio frequency (RF) applications. The FP induces the charge variation in the drain extension, which appears as either the extended depletion in the gate-off state or the electron accumulation in the gate-on state. Along with the FP, the DMG forms a step-like potential variation along the channel, which leads to electron acceleration and the screening effect on the drain-to-source voltage (V DS). These effects give significant advantages to the DC characteristics, including breakdown voltage (V BD) and on-resistance (R on), and the RF characteristics, including transconductance (g m) and output-resistance (r o). Compared to the latest high-voltage RF FinFETs, the DF-DeFF shows a drastic improvement in the major performance indicators such as V BD, cut-off frequency (f T), and maximum oscillation frequency (f MAX). These results indicate that DF-DeFF is a FinFET with sufficient competitiveness even in high voltage circumstances.

Calorie restriction and calorie dilution have different impacts on body fat, metabolism, behavior, and hypothalamic gene expression.

Caloric restriction is a robust intervention to increase lifespan. Giving less food (calorie restriction [CR]) or allowing free access to a diluted diet with indigestible components (calorie dilution [CD]) are two methods to impose restriction. CD does not generate the same lifespan effect as CR. We compare responses of C57BL/6 mice with equivalent levels of CR and CD. The two groups have different responses in fat loss, circulating hormones, and metabolic rate. CR mice are hungrier, as assessed by behavioral assays. Although gene expression of Npy, Agrp, and Pomc do not differ between CR and CD groups, CR mice had a distinctive hypothalamic gene-expression profile with many genes related to starvation upregulated relative to CD. While both result in lower calorie intake, CR and CD are not equivalent procedures. Increased hunger under CR supports the hypothesis that hunger signaling is a key process mediating the benefits of CR.

Development of surface ruptures by hanging-wall extension over a thrust ramp along the Ragged Mountain fault, Katalla, Alaska, USA: Applications of high-resolution three-dimensional terrain models

AbstractHigh-resolution three-dimensional terrain models are used to evaluate the Ragged Mountain fault kinematics (Katalla, Alaska, USA). Previous studies have produced contradictory interpretations of the fault’s kinematics because surface ruptures along the fault are primarily steeply dipping, uphill-facing normal fault scarps. In this paper, we evaluate the hypothesis that these uphill-facing scarps represent extension above a buried thrust ramp. Detailed geomorphic mapping along the fault, using 20-cm-resolution aerial imagery draped onto a 1-m-resolution lidar (light detection and ranging) elevation model, was used to produce multiple topographic profiles. These profiles illustrate scarp geometries and prominent convex-upward topographic surfaces, indicating significant disturbance by active tectonics. A theoretical model is developed for fault-parallel flow over a thrust ramp that shows the geometric relationships between thrust displacement, upper-plate extension, and ramp dip. An important prediction of the model for this study is that the magnitude of upper-plate extension is comparable to, or greater than, the thrust displacement for ramps with dips greater than ∼45°. This model is used to analyze profile shapes and surface displacements in Move software (Midland Valley Ltd.). Analyses of scarp heights allow estimates of hanging-wall extension, which we then use to estimate slip on the underlying thrust via the model. Assuming a low-angle (30°) uniformly dipping thrust and simple longitudinal extension via normal faulting, variations in extension along the fault would require a slip gradient from ∼8 m in the north to ∼22 m in the south. However, the same north-south variation in extension with a constant slip of 8–10 m may infer an increase in fault dip from ∼30° in the north to ∼60° in the south. This model prediction has broader implications for active-fault studies. Because the model quantifies relationships between hanging-wall extension, fault slip, and fault dip, it is possible to invert for fault slip in blind thrust ramps where hanging-wall extension is the primary surface manifestation. This study, together with results from the St. Elias Erosion and Tectonics Project (STEEP), clarifies the role of the Ragged Mountain fault as a contractional structure within a broadly sinistral shear system in the western syntaxis of the St. Elias orogeny.

Genetic and metabolomic architecture of variation in diet restriction-mediated lifespan extension in Drosophila.

In most organisms, dietary restriction (DR) increases lifespan. However, several studies have found that genotypes within the same species vary widely in how they respond to DR. To explore the mechanisms underlying this variation, we exposed 178 inbred Drosophila melanogaster lines to a DR or ad libitum (AL) diet, and measured a panel of 105 metabolites under both diets. Twenty four out of 105 metabolites were associated with the magnitude of the lifespan response. These included proteinogenic amino acids and metabolites involved in α-ketoglutarate (α-KG)/glutamine metabolism. We confirm the role of α-KG/glutamine synthesis pathways in the DR response through genetic manipulations. We used covariance network analysis to investigate diet-dependent interactions between metabolites, identifying the essential amino acids threonine and arginine as "hub" metabolites in the DR response. Finally, we employ a novel metabolic and genetic bipartite network analysis to reveal multiple genes that influence DR lifespan response, some of which have not previously been implicated in DR regulation. One of these is CCHa2R, a gene that encodes a neuropeptide receptor that influences satiety response and insulin signaling. Across the lines, variation in an intronic single nucleotide variant of CCHa2R correlated with variation in levels of five metabolites, all of which in turn were correlated with DR lifespan response. Inhibition of adult CCHa2R expression extended DR lifespan of flies, confirming the role of CCHa2R in lifespan response. These results provide support for the power of combined genomic and metabolomic analysis to identify key pathways underlying variation in this complex quantitative trait.

Variation in skeletal extension, density and calcification of the Scleractinian coral Porites lobate across the northern Persian Gulf

In chronological and geochemical studies of coral reefs, the annual coral growth bands function as an indicator for monitoring environmental change. In this study, the annual linear growth rates were measured in two core samples of Scleractinian coral Porites lobate collected from two geographically distinct islands across the northern Persian Gulf Using CoralXDS, the linear extension rates, densities, and calcification rates for each x-rayed samples were evaluated The mean (±SE) for extension (cm.yr−1), density (g.cm−3), and calcification (g.cm−2.yr−1) rates in Kharg Island within the period of 1985 to 2015 were 1.04 ± 0.05, 2.09 ± 0.01 and 2.17 ± 0.1, respectively and in Hendourabi Island within the period of 1999 to 2016 were 1.09 ± 0.07, 2.02 ± 0.02 and 2.19 ± 0.14, respectively The mean for a linear extension, skeletal density, and calcification rates were nearly 10% lower, 60% higher and close to the global average rates, respectively. No association was found between SST as independent variable and extension, skeletal density and calcification rates as dependent variables in both islands at this study. This suggests that the high inter-annual variability of growth parameters in this region might be the underlying reason for the poor association among these parameters with SST. The difference in the results of this study with others elsewhere in the world might be linked to the severe environmental stress under which reef-building corals occur in the Persian Gulf.

Surgical approaches, anaesthetic management and outcome in pediatric superior mediastinal tumors

BackgroundPediatric superior mediastinal tumors are a heterogeneous group of tumors with marked variation in pathology and extension. We reviewed our experience with different surgical approaches to tumors originating from or extending to superior mediastinum in pediatrics. Patients and methodsThe medical records of all patients who had undergone resection for superior mediastinal tumors in Children's Cancer Hospital – Egypt, between January 2008 to December 2015, were reviewed for demographic data, clinico-pathological features, radiologic findings, operative techniques and outcome. ResultsThe study included 20 patients. Diagnosis included: germ cell tumors (n=8), neuroblastoma (n=4), soft tissue sarcoma (n=3), thymolipoma (n=2), infantile fibromatosis (n=1), calcifying fibrous tumor (n=1), and thymic carcinoma (n=1). Tumor extension was divided into tumors extending unilaterally to one hemithorax (n=9), tumors extending bilaterally to both hemithoraces (n=4), and cervico thoracic junction tumors (n=7). Extended lateral thoracotomy was used in 8 patients. Other approaches included trapdoor (n=5), clamshell (n=4), cervical approach (n=2) and double level lateral thoracotomy (n=1). There was no perioperative mortality, and postoperative morbidity was 20%. At the end of December 2016, 15 patients were alive free of disease, 5 patients developed local and/ or distant relapse. ConclusionPediatric superior mediastinal tumors could be divided into 3 groups according to tumor extension. Each group has an optimum surgical approach that achieves the best exposure for adequate resection. However, further research is needed to confirm the conclusion as this was a descriptive study and the sample size was too small for valid statistical analysis.

Present-day stress fields of the Gulf of Suez (Egypt) based on exploratory well data: Non-uniform regional extension and its relation to inherited structures and local plate motion

The Gulf of Suez is the prototype model of a failed or aborted continental rift. However, the basin is seismically active and the footwalls of several major extensional faults continue to rise at the present time. Furthermore, decadal-length Global Positioning System (GPS) datasets demonstrate that the Sinai micro-plate continues to separate from Africa in a northerly direction at ∼0.15 cm/yr with a Gulf of Suez rift-normal component of ∼0.05 cm/yr. Geologic and GPS observations both indicate that the rift is now undergoing highly-oblique extension. Previous interpretations of borehole breakouts in industry exploration wells suggested that the minimum horizontal stress (Shmin) in the southern Gulf of Suez is presently aligned ∼015°. New subsurface data from the accommodation zone boundary between the Central and Darag (northern) sub-basins similarly identifies an extension direction of approximately N-S. By contrast, in the Central sub-basin itself breakout and drilling-induced fracture (DIF) data indicate NE-SW extension, or rift-normal movement that is similar to the documented older Miocene history of the entire basin. Based on these observations the present-day stress field of the Gulf of Suez is spatially non-uniform. Variations are also present in local and teleseismic datasets. The northern Gulf of Suez shows relatively less seismicity, with very few events greater than M = 3. The central sub-basin is very active, with 17 events M ≥ 3 during the past 45 years, and these suggest NE-SW extension similar to the breakout data. The southern Gulf of Suez is the most seismically active and merges with an area of significant seismicity in the northern Red Sea. In the southern Gulf of Suez the seismicity is complex but focal plane analyses of the two largest historical events indicated NNE-SSW extension, in agreement with the breakout data. Differing interpretations have been proposed for the smaller magnitude seismicity. We suggest that each of the three sub-basins of the Gulf of Suez, whose fault geometries are inherited from the main phase of Miocene continental rifting, are now subject to differing shallow crustal stress fields with variation in orientation and perhaps magnitude of the principal stresses. We do not know what the long-term implications for displacement fields throughout the rift might be, but along-strike variation in extension has been suggested in other ancient continental rift settings. This study also highlights the danger in assuming that fault populations with different kinematics must represent different times in a region's geologic evolution.

Ischial Form as an Indicator of Bipedal Kinematics in Early Hominins: A Test Using Extant Anthropoids.

Human ischia contrast with those of great apes in being craniocaudally short and dorsally projecting. This configuration is thought to facilitate greater hip extension in humans during bipedal locomotion. This link has been used to infer kinematics in early hominins, but the consequences of variation in ischial configuration for gait remain uncertain. Kinematic data for a limited sample of extant nonhuman primates demonstrate that there is variation in hip extension in these taxa during bipedal behaviors-specifically, Hylobates and Ateles are capable of greater extension than Pan and Macaca. In this study, we tested the hypothesis that ischial length and orientation are functionally linked with hip extension during bipedalism among these taxa. As expected, humans have the shortest ischia, followed by gibbons, spider monkeys, chimpanzees, and macaques. Our predictions for ischial orientation are not supported, however: macaques, gibbons, and spider monkeys do not vary in this trait, and they have ischia that are less dorsally angled than that of the chimpanzee. The results for ischium length provide limited support for the idea that the early hominin Ardipithecus ramidus, with its long, caudally oriented ischium was not capable of humanlike extended-hip bipedalism, and that the ischial shortening observed in post-Ardipithecus hominins reflects a shift toward a more humanlike gait. In contrast, while our results do not necessarily refute a link between ischial orientation and hip extension in hominins, they do not provide comparative support, making changes in ischial orientation in this part of the fossil record more difficult to interpret. Anat Rec, 300:845-858, 2017. © 2017 Wiley Periodicals, Inc.

Post-Levator Aponeurosis Fat Pad.

The aim of this study was to examine the superoinferior extension of the post-levator aponeurosis fat pad in the upper eyelids of Japanese cadavers. Twenty-six upper eyelids (12 right and 14 left) from 15 Japanese cadavers (6 men and 9 women; average age at death, 82.1 years) were used in this experimental anatomical study. After an orbital exenteration, the tissues were cut sagittally through the center of the orbit, and the superoinferior extension of the post-levator aponerosis fat pad was microscopically examined on the sections. Consequently, the fat pad superiorly reached the myotendinous junction between the levator aponeurosis and the levator palpebrae superioris (LPS) muscle in 17 eyelids with the nonbranching LPS muscle. The fat pad extended to the roots of the superior and inferior branches of the LPS muscle in the other 9 eyelids with the branching LPS muscle. Inferiorly, the fat pad was limited to the conjunctival fornix in 13 eyelids, but reached the tarsal plate in the other 13 eyelids. This study showed anatomical variation in the superoinferior extension of the post-levator aponerosis fat pad in Japanese cadavers.

How consistent are lordosis, range of movement and lumbo-pelvic rhythm in people with and without back pain?

BackgroundComparing movements/postures in people with and without lower back pain (LBP) may assist identifying LBP-specific dysfunction and its relationship to pain or activity limitation. This study compared the consistency in lumbo-pelvic posture and movement (range and pattern) in people with and without chronic LBP (>12 week’s duration).MethodsWireless, wearable, inertial measurement units measured lumbar lordosis angle, range of movement (ROM) and lumbo-pelvic rhythm in adults (n = 63). Measurements were taken on three separate occasions: two tests on the same day with different raters and a third (intra-rater) test one to two weeks later. Participants performed five repetitions of tested postures or movements. Test data were captured automatically. Minimal detectable change scores (MDC90) provided estimates of between-test consistency.ResultsThere was no significant difference between participants with and without LBP for lordosis angle. There were significant differences for pelvic flexion ROM (LBP 60.8°, NoLBP 54.8°, F(1,63) = 4.31, p = 0.04), lumbar right lateral flexion ROM (LBP 22.2°, NoLBP 24.6° F(1,63) = 4.48, p = .04), trunk right lateral flexion ROM (LBP 28.4°, NoLBP 31.7°, F(1,63) = 5.9, p = .02) and lumbar contribution to lumbo-pelvic rhythm in the LBP group (LBP 45.8 %, F(1,63) = 4.20, NoLBP 51.3 % p = .044). MDC90 estimates for intra and inter-rater comparisons were 10°–15° for lumbar lordosis, and 5°–15° for most ROM. For lumbo-pelvic rhythm, we found 8–15 % variation in lumbar contribution to flexion and lateral flexion and 36–56 % variation in extension. Good to excellent agreement (reliability) was seen between raters (mean r = .88, ICC (2,2)).ConclusionComparisons of ROM between people with and without LBP showed few differences between groups, with reduced relative lumbar contribution to trunk flexion. There was no difference between groups for lordosis. Wide, within-group differences were seen for both groups for ROM and lordosis. Due to variability between test occasions, changes would need to exceed 10°–15° for lumbar lordosis, 5°–15° for ROM components, and 8–15 % of lumbar contribution to lumbo-pelvic rhythm, to have 90 % confidence that movements had actually changed. Lordosis, range of movement and lumbo-pelvic rhythm typically demonstrate variability between same-day and different-day tests. This variability needs to be considered when interpreting posture and movement changes.Electronic supplementary materialThe online version of this article (doi:10.1186/s12891-016-1250-1) contains supplementary material, which is available to authorized users.

Spatio-temporal variability of micro-, nano- and pico-phytoplankton in the Mediterranean Sea from satellite ocean colour data of SeaWiFS

Abstract. The seasonal and year-to-year variability of the phytoplankton size class (PSC) spatial distribution has been examined in the Mediterranean Sea by using the entire time series of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) space observations (1998–2010). Daily maps of PSCs have been determined using an empirical model based on a synoptic relationship between surface chlorophyll a and diagnostic pigments referred to different taxonomic groups. The analysis of micro-, nano- and pico-phytoplankton satellite time series (1998–2010) describes, quantitatively, the algal assemblage structure over the basin and reveals that the main contribution to chlorophyll a in most of the Mediterranean Sea comes from the pico-phytoplankton component, especially in nutrient-poor environments. Regions with different and peculiar features are the Northwestern Mediterranean Sea, the Alborán Sea and several coastal areas, such as the North Adriatic Sea. In these areas, local interactions between physical and biological components modulate the composition of the three phytoplankton size classes. It results that, during the spring bloom season, micro-phytoplankton dominates in areas of intense vertical winter mixing and deep/intermediate water formation, while in coastal areas micro-phytoplankton dominates in all seasons because of the nutrient supply from the terrestrial inputs. In the Alborán Sea, where the Atlantic inflow modulates the nutrient availability, any predominance of one class over the other two has been observed. The nano-phytoplankton component instead remains widespread over the entire basin along the year, and its contribution to chlorophyll a is of the order of 30–40 %. The largest inter-annual signal occurs in the Northwestern Mediterranean Sea, driven by the year-to-year variation in intensity and extension of the spring bloom, followed by the Alborán Sea, in which the inter-annual variability is strongly modulated by the Atlantic inflow. In absence of sufficient in situ data of community composition, the satellite-based analysis demonstrated that pico-, nano- and micro-phytoplankton classes often coexist. The predominance of one group over the other ones is strongly dependent on the physical and biological processes occurring at the mesoscale. These processes directly influence the nutrient and light availability, which are the principal forcing for the algae growth.

Eccentric and Concentric Exercise of the Triceps Surae: An in Vivo Study of Dynamic Muscle and Tendon Biomechanical Parameters

Triceps surae eccentric exercise is more effective than concentric exercise for treating Achilles tendinopathy, however the mechanisms underpinning these effects are unclear. This study compared the biomechanical characteristics of eccentric and concentric exercises to identify differences in the tendon load response. Eleven healthy volunteers performed eccentric and concentric exercises on a force plate, with ultrasonography, motion tracking, and EMG applied to measure Achilles tendon force, lower limb movement, and leg muscle activation. Tendon length was ultrasonographically tracked and quantified using a novel algorithm. The Fourier transform of the ground reaction force was also calculated to investigate for tremor, or perturbations. Tendon stiffness and extension did not vary between exercise types (P = .43). However, tendon perturbations were significantly higher during eccentric than concentric exercises (25%–40% higher, P = .02). Furthermore, perturbations during eccentric exercises were found to be negatively correlated with the tendon stiffness (R2 = .59). The particular efficacy of eccentric exercise does not appear to result from variation in tendon stiffness or extension within a given session. However, varied perturbation magnitude may have a role in mediating the observed clinical effects. This property is subject-specific, with the source and clinical timecourse of such perturbations requiring further research.

The European Union as a system of differentiated integration: interdependence, politicization and differentiation

ABSTRACTThis contribution conceptualizes the European Union (EU) as a system of differentiated integration characterized by both variation in levels of centralization (vertical differentiation) and variation in territorial extension (horizontal differentiation) across policy areas. Differentiation has been a concomitant of deepening and widening and has increased and consolidated as the EU's powers, policy scope and membership have grown. Turning to explanation, the contribution attributes the pattern of differentiated integration in the EU to the interaction of interdependence and politicization. Differentiation among the member states (internal differentiation) results from supranational integration under conditions of high interdependence and politicization. By contrast, external differentiation (the selective policy integration of non-member states) occurs in highly interdependent but weakly politicized policy areas. These constellations are illustrated in case studies of differentiation in the internal market, monetary union and defence.

Underwater turning movement during foraging in Hydromedusa maximiliani (Testudines, Chelidae) from southeastern Brazil.

A type of locomotor behavior observed in animals with rigid bodies, that can be found in many animals with exoskeletons, shells, or other forms of body armor, to change direction, is the turning behavior. Aquatic floated-turning behavior among rigid bodies animals have been studied in whirligig beetles, boxfish, and more recently in freshwater turtle, Chrysemys picta. In the laboratory we observed a different kind of turning movement that consists in an underwater turning movement during foraging, wherein the animal pivoted its body, using one of the hindlimbs as the fixed-point support in the substratum. We describe, analyze and quantify this movement during foraging in Hydromedusa maximiliani, using observations made in the laboratory. We studied 3 adult specimens (2 males, 1 female) and 2 non-sexed juveniles of H. maximiliani. They were kept individually in an aquarium filled with water and small fish. They were filmed, in dorsal view, at 30 frames per second. Sequences were analyzed frame by frame and points were marked on limbs and shell to enable analysis of variation in limb flexion and extension, as well as rotation movements. While foraging, turtles frequently turned their bodies, using one hind leg as the pivot point. This underwater turning movement, in addition to slow movements with the neck stretched, or staying nearly immobile and scanning the surroundings with lateral movements of the neck (in arcs up to 180°), and fast attacks of neck, may increase prey capture rates.

Eccentric and concentric loading of the triceps surae: an in vivo study of dynamic muscle and tendon biomechanical parameters.

Triceps surae eccentric exercise is more effective than concentric exercise for treating Achilles tendinopathy, however the mechanisms underpinning these effects are unclear. This study compared the biomechanical characteristics of eccentric and concentric exercises to identify differences in the tendon load response. Eleven healthy volunteers performed eccentric and concentric exercises on a force plate, with ultrasonography, motion tracking, and EMG applied to measure Achilles tendon force, lower limb movement, and leg muscle activation. Tendon length was ultrasonographically tracked and quantified using a novel algorithm. The Fourier transform of the ground reaction force was also calculated to investigate for tremor, or perturbations. Tendon stiffness and extension did not vary between exercise types (P = .43). However, tendon perturbations were significantly higher during eccentric than concentric exercises (25%-40% higher, P = .02). Furthermore, perturbations during eccentric exercises were found to be negatively correlated with the tendon stiffness (R2 = .59). The particular efficacy of eccentric exercise does not appear to result from variation in tendon stiffness or extension within a given session. However, varied perturbation magnitude may have a role in mediating the observed clinical effects. This property is subject-specific, with the source and clinical time-course of such perturbations requiring further research.

Spatio-temporal variation in invasion of woodlands and forest by Phytophthora cinnamomi

This study determined spatio-temporal invasion dynamics of Phytophthora cinnamomi, examined differences between disease centres and inferred mechanisms of invasion. Patch disease extension was measured from aerial photographs of three Banksia woodland areas infested with P. cinnamomi. Disease extension was also determined from the fronts of six disease centres in Banksia woodland biomes and a disease front in Eucalyptus marginata forest. A localised, salient, disjunct pattern of spatial variation in upslope disease extension that occurred in all disease centres between years was probably due to growth of P. cinnamomi in major lateral roots and infection of plants by root to root contact. The square root of the area invaded was significantly related to year after first assessment (R 2 = 0.59–0.97). Linear rates of disease extension from baselines with years after first assessment ranged from 0.1 ± 0.07 and 1.46 ± 0.39 m/year. Differences in P. cinnamomi isolation frequency, community structure and measured variables in different soils did not indicate reasons for the variation in rate of invasion between Banksia woodland disease centres. Management options to limit invasion will depend on whether disease extension is the result of unrestricted movement of infectious propagules in overland and subsurface flows, or relatively restricted growth through roots and root to root contact. The hierarchy of factors affecting the invasive success of P. cinnamomi is discussed.

Quantitative trait loci controlling aluminum tolerance in soybean: candidate gene and single nucleotide polymorphism marker discovery

Aluminum (Al) toxicity is an important abiotic stress that affects soybean production in acidic soils throughout the world. Development of Al-tolerant cultivars is an efficient and environmentally friendly solution to the problem. A previous report identified quantitative trait loci (QTL) for Al tolerance inherited from PI 416937, using restriction fragment length polymorphism markers, in a population of Young × PI 416937. The population was genotyped with 162 simple sequence repeats to enhance the power of QTL detection and enable the selection of candidate genes for functional marker development. Two QTL that explained 54 % of the phenotypic variation in root extension under Al stress conditions (HIAL) were refined on chromosomes (chr) Gm08 and Gm16. Three QTL located on chr Gm08, Gm16 and Gm19 explained 59 % of the phenotypic variation in root extension as a percent of control (PC). Two major QTL, designated qAL_HIAL_08 and qAL_PC_08, controlling HIAL and PC, respectively, were mapped to the same genomic region on chr Gm08 and inherited their favorable allele from PI 416937. These QTL explained 45 and 41 % of phenotypic variation in HIAL and PC, respectively. Six homologues for citrate synthase (CS) genes were found in the soybean genome sequence at chr Gm02, Gm08, Gm14, Gm15, and Gm18. Sixteen single nucleotide polymorphisms (SNPs) were identified in the CS homologue on chr Gm08. A SimpleProbe assay of Glyma08g42400-SNP was developed for the major QTL on chr Gm08. The SNPs identified from this region could be used for marker-assisted selection of Al tolerance.

Simple shear detachment fault system and marginal grabens in the southernmost Red Sea rift

Abstract The NNW-SSE oriented Red Sea rift, which separates the African and Arabian plates, bifurcates southwards into two parallel branches, southeastern and southern, collectively referred to as the southernmost Red Sea rift. The southern branch forms the magmatically and seismo-tectonically active Afar rift, while the less active southeastern branch connects the Red Sea to the Gulf of Aden through the strait of Bab el Mandeb. The Afar rift is characterized by lateral heterogeneities in crustal thickness, and along-strike variation in extension. The Danakil horst, a counterclockwise rotating, narrow sliver of coherent continental relic, stands between the two rift branches. The western margin of the Afar rift is marked by a series of N-S aligned right-lateral-stepping and seismo-tectonically active marginal grabens. The tectonic configuration of the parallel rift branches, the alignment of the marginal grabens, and the Danakil horst are linked to the initial mode of stretching of the continental crust and its progressive deformation that led to the breakup of the once contiguous African–Arabian plates. We attribute the initial stretching of the continental crust to a simple shear ramp-flat detachment fault geometry where the marginal grabens mark the breakaway zone. The rift basins represent the ramps and the Danakil horst corresponds to the flat in the detachment fault system. As extension progressed, pure shear deformation dominated and overprinted the initial low-angle detachment fault system. Magmatic activity continues to play an integral part in extensional deformation in the southernmost Red Sea rift.

AB1289 What is the influence of variation in knee positioning during image acquisition on separate quantitative radiographic parameters of osteoarthritis?

BackgroundThe clinical application of quantitative measurement of separate radiographic parameters of knee osteoarthritis (OA) might be hampered by a lack of reproducible joint positioning during acquisition of the radiographs.ObjectivesTo evaluate...