167 research outputs found
2-Methylsulfanyl-5,6-dihydro-2H-1,3-dithiolo[4,5-b][1,4]dioxin-2-ium tetrafluoroborate
The title compound, C6H7O2S3
+·BF4
−, consists of a planar 2-thioxo-1,3-dithiol-4,5-yl unit [maximum deviation from the ring plane = 0.020 (3) Å], with an ethylenedioxy group fused at the 4,5-positions; the ethylenedioxy C atoms are disordered over two positions with site-occupancy factors of 0.5. The 1,4-dioxine ring has a twist-chair conformation. Weak cation–anion S⋯F interactions [3.022 (4)–3.095 (4) Å] and an S⋯O [3.247 (4) Å] interaction are present
Influence of host plant nitrogen fertilization on haemolymph protein profiles of herbivore Spodoptera exigua and development of its endoparasitoid Cotesia marginiventris
Citation: Chen, Y., Ruberson, J. R., & Ni, X. (2014). Influence of host plant nitrogen fertilization on haemolymph protein profiles of herbivore Spodoptera exigua and development of its endoparasitoid Cotesia marginiventris. Retrieved from http://krex.ksu.eduNitrogen has complex effects on plant-herbivore-parasitoid tri-trophic interactions. The negative effects of host plant low nitrogen fertilization on insect herbivores in many cases can be amplified to the higher trophic levels. In the present study, we examined the impact of varying nitrogen fertilization (42, 112, 196, and 280 ppm) on cotton plants (Gossypium hirsutum L.) on the interactions between the beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), and the hymenopteran endoparasitoid Cotesia marginiventris (Cresson) (Hymenoptera: Braconidae). We predicted that the development and fitness of C. marginiventris would be adversely affected by low host plant nitrogen fertilization through the herbivore S. exigua. The percentage of C. marginiventris offspring developing to emerge and spin a cocoon, and total mortality of parasitized S. exigua larvae were unaffected by nitrogen level. The developmental time of C. marginiventris larvae in S. exigua larvae feeding on low (42 ppm) nitrogen cotton plants was approximately 30% longer than that of those feeding on high (112, 196, and 280 ppm) nitrogen plants. Parasitoid size (length of right metathoracic tibia), a proxy for fitness, of C. marginiventris males was positively affected by nitrogen level. Total amounts of S. exigua haemolymph proteins were not affected by nitrogen level, but were reduced by parasitism by C. marginiventris. Two proteins with molecular weights of ca. 84 and 170 kDa dominated the S. exigua larval haemolymph proteins. Concentrations of the 170 kDa haemolymph protein were unaffected by nitrogen treatment, but parasitism reduced concentrations of the the 170 kDa protein. Concentrations of the 84 kDa protein, on the other hand, were interactively affected by parasitism and nitrogen treatment: higher nitrogen fertilization (112, 196, and 280 ppm) increased protein concentrations relative to the 42 ppm treatment for unparasitized S. exigua larvae, whereas nitrogen treatment had no effects on parasitized larvae. For S. exigua larvae feeding on 42 ppm nitrogen plants, parasitism increased concentration of the 84 kDa protein, while for those feeding on 112, 196, and 280 ppm nitrogen plants, parasitism decreased concentrations of the protein. Possible mechanisms and ecological consequences for the extended development of C. marginiventris on S. exigua hosts grown on low-nitrogen plants are discussed
Understanding Heterogeneity of Automated Vehicles and Its Traffic-level Impact: A Stochastic Behavioral Perspective
This paper develops a stochastic and unifying framework to examine
variability in car-following (CF) dynamics of commercial automated vehicles
(AVs) and its direct relation to traffic-level dynamics. The asymmetric
behavior (AB) model by Chen at al. (2012a) is extended to accommodate a range
of CF behaviors by AVs and compare with the baseline of human-driven vehicles
(HDVs). The parameters of the extended AB (EAB) model are calibrated using an
adaptive sequential Monte Carlo method for Approximate Bayesian Computation
(ABC-ASMC) to stochastically capture various uncertainties including model
mismatch resulting from unknown AV CF logic. The estimated posterior
distributions of the parameters reveal significant differences in CF behavior
(1) between AVs and HDVs, and (2) across AV developers, engine modes, and speed
ranges, albeit to a lesser degree. The estimated behavioral patterns and
simulation experiments further reveal mixed platoon dynamics in terms of
traffic throughout reduction and hysteresis
Cross-talks between perivascular adipose tissue and neighbors: multifaceted nature of nereids
Perivascular adipose tissue (PVAT) is a unique fat depot surrounding blood vessels and plays a vital role in the progression of vascular remodeling and dysfunction. PVAT exhibits remarkable differences in structure, phenotype, origin, and secretome across anatomical locations. The proximity of PVAT to neighboring vascular beds favors a niche for bidirectional communication between adipocytes and vascular smooth muscle cells, endothelial cells, and immune cells. In this review, we update our understanding of PVAT’s regional differences and provide a comprehensive exploration of how these differences impact cross-talks between PVAT and the vascular wall. Different PVAT depots show different degrees of vasoprotective function and resilience to pathological changes such as obesity and vasculopathies, shaping multifaceted interactions between PVAT depots and adjacent vasculatures. The depot-specific resilience may lead to innovative strategies to manage cardiometabolic disorders
4-(Pyridin-2-yl)-1,3-dithiol-2-one
In the title compound, C8H5NOS2, the non-H atoms are approximately coplanar [maxium deviation = 0.060 (3) Å]. The dihedral angle between the least-squares planes of the pyridine and 1,3-dithiol-2-one rings is 5.96 (17)°. The crystal packing is stabilized by weak intermolecular C—H⋯O hydrogen bonds and by an S⋯S close contact [3.510 (5) Å]
Linking the SO2 emission of cement plants to the sulfur characteristics of their limestones: A study of 80 NSP cement lines in China
In a properly operated new suspension preheater (NSP) cement line, the SO2 emission is mainly originated from sulfides in the raw meal, and limestone, occupying about 85% wt. of the raw meal, is the dominant sulfur source. However, the sulfur characteristics of limestones and then their influences on the SO2 emission have not been clarified yet. In the present study, 80 NSP cement lines with SO2 emission > 200 mg/Nm3 were recorded, the sulfur content and species as well as pyrite morphology of limestones were analyzed and then correlated to their resulting SO2 emission. The results show that the SO2 emission of stack gas increases linearly with the SO3 content of limestone used, and sulfates lead to a 50% reduction in SO2 emission relative to sulfides. Compared with average SO2 emission, euhedral pyrite leads to a slightly higher SO2 emission, whereas metasomatic pyrite results in a lower SO2 emission, which can be attributed to the effects of accompanying elements (Ti, F, K, and Al etc.) on the desulfurization reaction and clinkerization in the whole NSP cement line. The relationships proposed can be used to predict the SO2 emission based on the sulfur characteristics of limestone and to rationally utilize high-sulfur limestone in cement industry
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