4,071 research outputs found
The Invincible (1758) site: an integrated geophysical assessment
Chirp sub-bottom profiler and repeat sidescan sonar imaging of the Invincible wreck site (1758) in the Solent (U.K.), interpretation, and implications for management of the site
Draft genome sequence of an endophytic bacterium, Paenibacillus tyrfis strain SUK123, isolated from Santiria apiculata stem
Here we report the draft genome sequence of an endophytic Paenibacillus tyrfis strain isolated from the Universiti Kebangsaan Malaysia reserve forest, Malaysia. The genome size was approximately 8.04 Mb, and the assembly consisted of 107 scaffolds with 168 contigs, and had a G + C content of 53%. Phylogenetic analysis of strain SUK123 using the 16S rRNA gene revealed that it belonged to the family Paenibacillaceae with the highest similarity to Paenibacillus elgii SDT (99%). Whole genome comparison of SUK123 with related species using average nucleotide identity (ANI) analysis revealed a similarity of 98% to Paenibacillus tyrfis Mst1T, 94% to Paenibacillus elgii B69T, 91% to Paenibacillus ehimensis A2T, 68% to Paenibacillus polymyxa SC2T and 69% to Paenibacillus alvei DMS29T. The draft genome was deposited at the European Nucleotide Archive (PRJEB21373)
Pressure-Dependent, Infrared-Emitting Phenomenon in Hypervelocity Impact
A series of hypervelocity impact experiments were conducted with variable target chamber atmospheric pressure ranging from 0.9 to 21.5 Torr. Using a two-stage light-gas gun, 5.7 mg nylon 6/6 right-cylinders were accelerated to speeds ranging between 6.0 and 6.3 km/s to impact 1.5 mm thick 6061-T6 aluminum plates. Full-field images of near-IR emission (0.9 to 1.7 μm) were measured using a high-speed spectrograph system with image exposure times of 1 μs. The radial expansion of an IR-emitting impact-generated phenomenon was observed to be dependent upon the ambient target chamber atmospheric pressures. Higher chamber pressures demonstrated lower radial expansions of the subsequently measured IR-emitting region uprange of the target. Dimensional analysis, originally presented by Taylor to describe the expansion of a hemispherical blast wave, is applied to describe the observed pressure-dependence of the IR-emitting cloud expansion. Experimental results are used to empirically determine two dimensionless constants for the analysis. The maximum radial expansion of the observed IR-emitting cloud is described by the Taylor blast-wave theory, with experimental results demonstrating the characteristic nonlinear dependence on atmospheric pressure. Furthermore, the edges of the measured IR-emitting clouds are observed to expand at extreme speeds ranging from approximately 13 to 39 km/s. In each experiment, impact ejecta and debris are simultaneously observed in the visible range using an ultrahigh-speed laser shadowgraph system. For the considered experiments, ejecta and debris speeds are measured between 0.6 and 5.1 km/s. Such a disparity in observed phenomena velocities suggests the IR-emitting cloud is a distinctly different phenomenon to both the uprange ejecta and downrange debris generated during a hypervelocity impact
Examining the temporal evolution of hypervelocity impact phenomena via high-speed imaging and ultraviolet-visible emission spectroscopy
The temporal evolution of a previously observed hypervelocity impact-induced vapor cloud [Mihaly et al., Int. J. Impact Eng. 62, 13 (2013)] was measured by simultaneously recording several full-field, near-IR images of the resulting emission using an OMA-V high-speed camera. A two-stage light-gas gun was used to accelerate 5 mg Nylon 6/6 right-cylinders to speeds between 5 km/s and 7 km/s to impact 1.5 mm thick 6061-T6 aluminum target plates. Complementary laser-side-lighting [Mihaly et al., Int. J. Impact Eng. 62, 13 (2013); Proc. Eng. 58, 363 (2013)] and front-of-target (without laser illumination) images were also captured using a Cordin ultra-high-speed camera. The rapid expansion of the vapor cloud was observed to contain a bright, emitting exterior, and a darker, optically thick interior. The shape of this phenomenon was also observed to vary considerably between experiments due to extremely high-rate (>250 000 rpm) of tumbling of the cylindrical projectiles. Additionally, UV-vis emission spectra were simultaneously recorded to investigate the temporal evolution of the atomic and molecular composition of the up-range, impact-induced vapor plume. A PI-MAX3 high-speed camera coupled to an Acton spectrograph was utilized to capture the UV-vis spectra, which shows an overall peak in emission intensity between approximately 6–10 ls after impact trigger, corresponding to an increased quantity of emitting vapor/plasma passing through the spectrometer slit during this time period. The relative intensity of the numerous spectral bands was also observed to vary according to the exposure delay of the camera, indicating that the different atomic/molecular species exhibit a varied temporal evolution during the vapor cloud expansion. Higher resolution spectra yielded additional emission lines/bands that provide further evidence of interaction between fragmented projectile material and the 1 mmHg atmosphere inside the target chamber. A comparison of the data to down-range emission spectra also revealed differences in the relative intensities of the atomic/molecular composition of the observed vapor clouds
Recent advances in the study of development, social and personal experience, and psychopathology
The field of developmental psychopathology has been challenged by various issues in understanding the link between social experiences and psychopathology. These challenges involve conceptual, methodological and statistical concerns that are often interrelated. This article examines four advances in resolving these concerns. First, co-rumination and deviancy training are discussed as specific interpersonal processes that are examples of important social experiences for predicting psychopathology. Second, dynamic properties of dyadic interaction are discussed as one of the recent advances in methodology for this area. Third, the Actor-Partner Interdependence Model is outlined as one of the recent statistical advances in the study of individuals within a dyad. Fourth, changes in the study of culture are presented as informing the understanding link between social experiences and developmental psychopathology
Evolution and Expression of MYB Genes in Diploid and Polyploid Cotton
R2R3-MYB transcription factors have been implicated in a diversity of plant-specific processes. Among the functions attributed to myb factors is the determination of cell shape, including regulation of trichome length and density. Because myb transcription factors are likely to play a role in cotton fiber development, the molecular evolutionary properties of six MYB genes previously shown to be expressed in cotton fiber initiation were examined. In accordance with their presumed central role, each of the genes display conservative substitution patterns and limited sequence divergence in diploid members of the genus Gossypium, and this pattern is conserved in allotetraploid cottons. In contrast to highly reiterated rDNA repeats, GhMYB homologues (duplicated gene pairs) exhibit no evidence of concerted evolution, but instead appear to evolve independently in the allopolyploid nucleus. Expression patterns for the MYB genes were examined in several organs to determine if there have been changes in expression patterns between the diploids (G. raimondii and G. arboreum) and the tetraploid (G. hirsutum) or between the duplicated copies in the tetraploid. Spatial and temporal expression patterns appear to have been evolutionarily conserved, both during divergence of the diploid parents of allopolyploid cotton and following polyploid formation. However, the duplicated copies of MYB1 in the tetraploid are not expressed at equal levels or equivalently in all organs, suggesting possible functional differentiation
Phenotopic Plasticity of Leaf Shape Along a Temperature Gradient in \u3cem\u3eAcer Rubrum\u3c/em\u3e
Both phenotypic plasticity and genetic determination can be important for understanding how plants respond to environmental change. However, little is known about the plastic response of leaf teeth and leaf dissection to temperature. This gap is critical because these leaf traits are commonly used to reconstruct paleoclimate from fossils, and such studies tacitly assume that traits measured from fossils reflect the environment at the time of their deposition, even during periods of rapid climate change. We measured leaf size and shape in Acer rubrum derived from four seed sources with a broad temperature range and grown for two years in two gardens with contrasting climates (Rhode Island and Florida). Leaves in the Rhode Island garden have more teeth and are more highly dissected than leaves in Florida from the same seed source. Plasticity in these variables accounts for at least 6–19 % of the total variance, while genetic differences among ecotypes probably account for at most 69–87 %. This study highlights the role of phenotypic plasticity in leaf-climate relationships. We suggest that variables related to tooth count and leaf dissection in A. rubrum can respond quickly to climate change, which increases confidence in paleoclimate methods that use these variables
Rainforest conversion to rubber plantation may not result in lower soil diversity of bacteria, fungi, and nematodes
Large areas of rainforest in Asia have been converted to plantations, with uncertain effects on soil biodiversity. Using standard metagenetic methods, we compared the soil biota of bacteria, fungi, and nematodes at three rainforest sites in Malaysia with two rubber plantation sites with similar soils and geology. We predicted the following: (1) that the rubber sites would have a lower α- and β-diversity than the rainforest sites, due to the monospecific canopy cover and intensive management with herbicides, pesticides, and fertilizers, and (2) that due to differences in the physical and biotic environment associated with cultivation, there would be distinct communities of bacteria, fungi, and nematodes. However, regarding (1), the results showed no consistent difference in α- and β-diversity of bacteria, fungi, or nematodes between rainforest and rubber plantation sites. It appears that conversion of rainforest to rubber plantations does not necessarily result in a decrease in diversity of soil biota. It may be that heterogeneity associated with the cultivation regimen compensates for loss of biotically imposed heterogeneity of the original rainforest. Regarding (2), as predicted there were statistically significant differences in community composition between rainforest and rubber plantation for bacteria, fungi, and nematodes. These differences could be related to a range of factors including light level, litter fall composition, pH, C and N, selecting a distinct set of soil taxa, and it is possible that this in itself would affect long-term soil function
Reactivity and Distortions in the Self: Narcissism, Types of Aggression, and the Functioning of the Hypothalamic–Pituitary–Adrenal Axis During Early Adolescence
A multisample, multistudy project aimed at understanding how individual differences in narcissism during early adolescence are related to distortions in the aggression, and the reactivity of the hypothalamic–pituitary–adrenal axis to negative and positive experiences. The findings indicate that individual differences in narcissism are a remarkably stable aspect of personality during early adolescence. It is predictably related to an inflated view of the self that is not warranted by objective indices of social functioning. Further evidence shows that it promotes the continuity of aggressive behavior and is more strongly related to reactive aggression than to proactive aggression and more strongly related to relational aggression than to physical aggression. Finally, there is evidence that distortions in the self may derive from the inadequate functioning of the hypothalamic–pituitary–adrenal axis, one of the body’s main response system for dealing with stress. These findings are discussed in terms of the processes by which early adolescents react to threats and arousal in their daily functioning
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