Mixed Chain Research Articles

Cellulose Structural Polymorphism in Plant Primary Cell Walls Investigated by High-Field 2D Solid-State NMR Spectroscopy and Density Functional Theory Calculations.

The native cellulose of bacterial, algal, and animal origins has been well studied structurally using X-ray and neutron diffraction and solid-state NMR spectroscopy, and is known to consist of varying proportions of two allomorphs, Iα and Iβ, which differ in hydrogen bonding, chain packing, and local conformation. In comparison, cellulose structure in plant primary cell walls is much less understood because plant cellulose has lower crystallinity and extensive interactions with matrix polysaccharides. Here we have combined two-dimensional magic-angle-spinning (MAS) solid-state nuclear magnetic resonance (solid-state NMR) spectroscopy at high magnetic fields with density functional theory (DFT) calculations to obtain detailed information about the structural polymorphism and spatial distributions of plant primary-wall cellulose. 2D (13)C-(13)C correlation spectra of uniformly (13)C-labeled cell walls of several model plants resolved seven sets of cellulose chemical shifts. Among these, five sets (denoted a-e) belong to cellulose in the interior of the microfibril while two sets (f and g) can be assigned to surface cellulose. Importantly, most of the interior cellulose (13)C chemical shifts differ significantly from the (13)C chemical shifts of the Iα and Iβ allomorphs, indicating that plant primary-wall cellulose has different conformations, packing, and hydrogen bonding from celluloses of other organisms. 2D (13)C-(13)C correlation experiments with long mixing times and with water polarization transfer revealed the spatial distributions and matrix-polysaccharide interactions of these cellulose structures. Celluloses f and g are well mixed chains on the microfibril surface, celluloses a and b are interior chains that are in molecular contact with the surface chains, while cellulose c resides in the core of the microfibril, outside spin diffusion contact with the surface. Interestingly, cellulose d, whose chemical shifts differ most significantly from those of bacterial, algal, and animal cellulose, interacts with hemicellulose, is poorly hydrated, and is targeted by the protein expansin during wall loosening. To obtain information about the C6 hydroxymethyl conformation of these plant celluloses, we carried out DFT calculations of (13)C chemical shifts, using the Iα and Iβ crystal structures as templates and varying the C5-C6 torsion angle. Comparison with the experimental chemical shifts suggests that all interior cellulose favor the tg conformation, but cellulose d also has a similar propensity to adopt the gt conformation. These results indicate that cellulose in plant primary cell walls, due to their interactions with matrix polysaccharides, and has polymorphic structures that are not a simple superposition of the Iα and Iβ allomorphs, thus distinguishing them from bacterial and animal celluloses.

Effect of the thiophene and selenophene moiety in regular terpolymers on the performance of thin film transistors and polymer solar cells

We demonstrated the effective structural control of the conjugation length and various donor moieties using thiophene and selenophene derivatives in a regular terpolymer system and compared the properties with two copolymers of PDPP-SS and PDPP-TT. The three different terpolymers are composed of diketopyrrolopyrrole (DPP)-based polymers such as PDPP-TTS, PDPP-TSS, and PDPP-TTSS. The optical and electronic properties of these regular terpolymers can be precisely controlled by varying the conjugation length of the repeating unit and the composition ratio of the thiophene and selenophene moieties. It was found from the grazing incidence X-ray diffraction that PDPP-TTS and PDPP-TSS with different lengths of donor moieties exhibited mixed chain orientations in face-on and edge-on manners on the substrate. However, PDPP-TTSS showed edge-on chain orientation which is similar to the copolymers of PDPP-TT and PDPP-SS, and much improved charge-carrier mobility. Moreover, the enhanced power conversion efficiencies (PCEs) of polymer solar cells made of PDPP-TSS and PDPP-TTSS were observed to be 4.18 and 4.76%, respectively, owing to the higher composition of thiophene, which could be compensated by the properties of thiophene. As a result, the PCEs of regular terpolymers were markedly enhanced by inserting the thiophene moiety into the donor part of the DPP-based terpolymer, PDPP-SS.

Motion/Force Transmission Analysis of Planar Parallel Mechanisms With Closed-Loop Subchains

Singularities are one of the most important issues affecting the performance of parallel mechanisms. Therefore, analysis of their locations and closeness is essential for the development of a high-performance mechanism. The screw theory based motion/force transmission analysis provides such a closeness measure in terms of the work performed between specific mechanism twists and wrenches. As such, this technique has been applied to many serial chain parallel mechanisms. However, the motion/force transmission performance of parallel mechanisms with mixed topology chains is yet to be examined. These chains include linkages in both series and parallel, where the parallel portion is termed a closed-loop subchain (CLSC). This paper provides an analysis of such chains, where the CLSC is a planar four-bar linkage. In order to completely define the motion/force transmission abilities of these mechanisms, adapted wrench definitions are introduced. The proposed methodology is applied to a family of two degrees-of-freedom planar axis-symmetric parallel mechanisms, each with a different CLSC configuration. The presented analysis provides the first complete motion/force transmission analysis of such mechanisms.

A comprehensive framework to assess the sustainability of nutrient use in global livestock supply chains

The assessment of the performance of nutrient use along livestock supply chains can help to identify targeted nutrient management interventions, with a goal to benchmark and to monitor the improvement of production practices. It is necessary, therefore, to develop indicators that are capable to describe all nutrient dynamics and management along the chain. This paper proposed a comprehensive framework, based on life-cycle thinking, to assess the sustainability of nitrogen and phosphorus use. The proposed framework represents nutrient flows in typical livestock supply chain from the “cradle-to-primary-processing-gate”, including crop/pasture production, animal production, and primary processing stage as well as the transportation of feed materials, live-animals or animal products. In addition, three indicators, including the life-cycle nutrient use efficiency (life-cycle-NUE), life-cycle net nutrient balance (life-cycle-NNB) and nutrient hotspot index (NHI) were proposed and tested in a case study of mixed dairy supply chains in Europe. Proposed indicators were found to be suitable to describe different aspects of nitrogen and phosphorus dynamics and, therefore, were all needed. Moreover, the disaggregation of life-cycle-NUE and life-cycle-NNB has been investigated and the uncertainties related to the choice of the method used to estimate changes in nutrient soil stock have been discussed. Given these uncertainties, the choice of method to compute the proposed indicators is determined by data availability and by the goal and scope of the exercise.

Is the choice of a farm’s commercial market an indicator of agricultural intensity? Conventional and short food supply chains in periurban farming systems

Short food supply chains (SFSCs) have been identified as an economic opportunity for agriculture under urban pressure, as well as drivers for more sustainable farming systems. However, few studies have focused on the intensity of periurban farms that participate in such SFSCs, compared with the performance of the other farms. In this paper, we examined the relationship between agricultural intensity and the market orientation in a representative sample of farms in the urban area of Pisa (Italy). We define agricultural intensity as the intensity of land use and its main drivers (e.g., farm management or the individual characteristics of farmers), and market orientation as the ratio of farm produce within conventional, short or mixed foodsupply chains. The results suggest that the market orientation of periurban farming systems is more correlated to the indicators of farm management and land use intensity than to the individual farmer’s characteristics. This result provides the first evidence that market orientation is a driver of intensity, and that individual farmer’s characteristics are not significantly different in the three groups of market orientation. These findings could be generalised to other urban areas and correlated with the main orientation of farming systems in order to support both the assessment of farming systems and the implementation of innovative urban food policies.

Cooperativity of the SUMO and Ubiquitin Pathways in Genome Stability.

Covalent attachment of ubiquitin (Ub) or SUMO to DNA repair proteins plays critical roles in maintaining genome stability. These structurally related polypeptides can be viewed as distinct road signs, with each being read by specific protein interaction motifs. Therefore, via their interactions with selective readers in the proteome, ubiquitin and SUMO can elicit distinct cellular responses, such as directing DNA lesions into different repair pathways. On the other hand, through the action of the SUMO-targeted ubiquitin ligase (STUbL) family proteins, ubiquitin and SUMO can cooperate in the form of a hybrid signal. These mixed SUMO-ubiquitin chains recruit “effector” proteins such as the AAA+ ATPase Cdc48/p97-Ufd1-Npl4 complex that contain both ubiquitin and SUMO interaction motifs. This review will summarize recent key findings on collaborative and distinct roles that ubiquitin and SUMO play in orchestrating DNA damage responses.

Berry–Esseen type estimates for nonconventional sums

We obtain Berry-Esseen type estimates for “nonconventional” expressions of the form ξN=1N∑n=1N(F(X(q1(n)),…,X(qℓ(n)))−F̄) where X(n) is a sufficiently fast mixing vector process with some moment conditions and stationarity properties, F is a continuous function with polynomial growth and certain regularity properties, F̄=∫Fd(μ×⋯×μ), μ is the distribution of X(0) and qi(n)=in for 1≤i≤k while for i>k they are positive functions taking integer values with some growth conditions which are satisfied, for instance, when they are polynomials of increasing degrees. Our setup is similar to Kifer and Varadhan (2014) where a nonconventional functional central limit theorem was obtained and the present paper provides estimates for the convergence speed. As a part of the study we provide answers for the crucial question on positivity of the limiting variance limN→∞Var(ξN) which was not studied in Kifer and Varadhan (2014). Extensions to the continuous time case will be discussed as well. As in Kifer and Varadhan (2014) our results are applicable to stationary processes generated by some classes of sufficiently well mixing Markov chains and dynamical systems.

A unified structure theory of multibody open-, closed-, and mixed-loop mechanical systems with simple and multiple joint kinematic chains

This study establishes a “structure theory,” including topology, common properties, synthesis, and analysis of various F-DOF, ñ-link, K-independent loops, and V-multiple joint factors for open, closed, and mixed kinematic chains with simple and multiple joints (if any). This structure theory can be used to study planar, spatial, as well as hybrid nonfractionated and fractionated mechanical systems that are intended to function in any given workspace 1≤h≤6. Accordingly, we propose universal general dependences of mobility equations, total multiple joint factor, and assembly criterion for any valid planar, spatial, and hybrid open, closed, and mixed multiloop simple and multiple joint kinematic chains for the first time. Furthermore, it is important to note that all our results correspond one to one to as well as supplement to the separate well-known dependences and computer number results proposed and calculated by L. Euler, M. Gruebler, L. Assur, and F.R.E. Crossley. The basic general structural dependences represented in this study can be possibly used to further improve the mechanism and machine theory as well as accelerate the creative design process in the conceptual stage of machinery for development of robots, manipulators, mechanisms, clamping devices, truss structures, and so on.

Trapped ion chain thermometry and mass spectrometry through imaging.

We demonstrate a spatial-imaging thermometry technique for ions in a one-dimensional Coulomb crystal by relating their imaged spatial extent along the linear radiofrequency ion trap axis to normal modes of vibration of coupled oscillators in a harmonic potential. We also use the thermal spatial spread of "bright" ions in the case of a two-species mixed chain to measure the center-of-mass resonance frequency of the entire chain and infer the molecular composition of the co-trapped "dark" ions. These non-destructive techniques create new possibilities for better understanding of sympathetic cooling in mixed-ion chains, improving few-ion mass spectrometry, and trapped-ion thermometry without requiring a scan of Doppler cooling parameters.

Hydrocarbon/perfluorocarbon mixed chain azides for surface post-functionalization

Abstract Here, we report the synthesis of original hydrocarbon/perfluorocarbon mixed chain azides for surface post-functionalization. The use of mixed side chain allows to get fluorine properties with reduced amount of fluorine. The synthetized azide are grafted on surface using the Huisgen reaction. Post-modified surfaces were then investigated for their wettability, morphologies and roughness.

Toward a scalable quantum computing architecture with mixed species ion chains

We report on progress toward implementing mixed ion species quantum information processing for a scalable ion-trap architecture. Mixed species chains may help solve several problems with scaling ion-trap quantum computation to large numbers of qubits. Initial temperature measurements of linear Coulomb crystals containing barium and ytterbium ions indicate that the mass difference does not significantly impede cooling at low ion numbers. Average motional occupation numbers are estimated to be $$\bar{n} \approx 130$$n¯ź130 quanta per mode for chains with small numbers of ions, which is within a factor of three of the Doppler limit for barium ions in our trap. We also discuss generation of ion---photon entanglement with barium ions with a fidelity of $$F \ge 0.84$$Fź0.84, which is an initial step towards remote ion---ion coupling in a more scalable quantum information architecture. Further, we are working to implement these techniques in surface traps in order to exercise greater control over ion chain ordering and positioning.

Enhanced Performance of Polymer Solar Cells Comprising Diketopyrrolopyrrole-Based Regular Terpolymer Bearing Two Different π-Extended Donor Units.

New regular and random diketopyrrolopyrrole (DPP)-based terpolymers (i.e., Reg-PBDPPT and Ran-PBDPPT, respectively) bearing DPP as an electron deficient unit and 2,2'-bithiophene and (E)-1,2-di(thiophen-2-yl)ethene as electron donating units were designed and synthesized, and their performance in photovoltaic cells was investigated precisely. The absorption properties and highest occupied molecular orbital (HOMO) of Reg-PBDPPT were found to be different from those of Ran-PBDPPT. The results of grazing incidence X-ray diffraction experiments revealed that Ran-PBDPPT typically had a predominantly edge-on chain orientation on the substrate, whereas Reg-PBDPPT showed mixed chain orientation both in pristine and thermally annealed films. Although Reg-PBDPPT exhibited a lower degree of edge-on chain orientation on the substrate, the corresponding TFTs showed a high hole mobility of 0.42-0.96 cm(2) V(-1) s(-1) and maintained a high current on/off ratio (>10(6)). A polymer solar cell (PSC) composed of Reg-PBDPPT and PC71BM exhibited power conversion efficiencies (PCE) of 5.24-5.45%, which were higher than those of the Ran-PBDPPT-based PSCs. The enhanced efficiency was supported by an increase in the short circuit current, which is strongly related to the unique internal crystalline morphology and pronounced nanophase segregation behavior in the blend films. These results obviously manifested that this synthetic strategy for regular conjugated terpolymers could be employed to control morphological properties to obtain high-performance PSCs.

Myosin content of individual human muscle fibers isolated by laser capture microdissection.

Muscle fiber composition correlates with insulin resistance, and exercise training can increase slow-twitch (type I) fibers and, thereby, mitigate diabetes risk. Human skeletal muscle is made up of three distinct fiber types, but muscle contains many more isoforms of myosin heavy and light chains, which are coded by 15 and 11 different genes, respectively. Laser capture microdissection techniques allow assessment of mRNA and protein content in individual fibers. We found that specific human fiber types contain different mixtures of myosin heavy and light chains. Fast-twitch (type IIx) fibers consistently contained myosin heavy chains 1, 2, and 4 and myosin light chain 1. Type I fibers always contained myosin heavy chains 6 and 7 (MYH6 and MYH7) and myosin light chain 3 (MYL3), whereas MYH6, MYH7, and MYL3 were nearly absent from type IIx fibers. In contrast to cardiomyocytes, where MYH6 (also known as α-myosin heavy chain) is seen solely in fast-twitch cells, only slow-twitch fibers of skeletal muscle contained MYH6. Classical fast myosin heavy chains (MHC1, MHC2, and MHC4) were present in variable proportions in all fiber types, but significant MYH6 and MYH7 expression indicated slow-twitch phenotype, and the absence of these two isoforms determined a fast-twitch phenotype. The mixed myosin heavy and light chain content of type IIa fibers was consistent with its role as a transition between fast and slow phenotypes. These new observations suggest that the presence or absence of MYH6 and MYH7 proteins dictates the slow- or fast-twitch phenotype in skeletal muscle.

Identification and characterization of a novel ISG15-ubiquitin mixed chain and its role in regulating protein homeostasis.

As a ubiquitin-like modifier, ISG15 is conjugated to many cellular proteins in a process termed protein ISGylation. However, the crosstalk between protein ISGylation and the ubiquitin proteasome system is not fully understood. Here, we report that cellular ubiquitin is a substrate of ISG15 and Lys 29 on ubiquitin is the major ISG15 acceptor site. Using a model substrate, we demonstrate that ISG15 can modify ubiquitin, which is immobilized on its substrate, to form ISG15-ubiquitin mixed chains. Furthermore, our results indicate that ISG15-ubiquitin mixed chains do not serve as degradation signals for a ubiquitin fusion degradation substrate. Accordingly, an ISG15-ubiquitin fusion protein, which mimics an ISG15-ubiquitin mixed chain, negatively regulates cellular turnover of ubiquitylated proteins. In addition, ISG15-ubiquitin mixed chains, which are detectable on endogenously ubiquitylated proteins, dampen cellular turnover of these proteins. Thus, our studies unveil an unanticipated interplay between two protein modification systems and highlight its role in coordinating protein homeostasis.

Combined study of Schwinger-boson mean-field theory and linearized tensor renormalization group on Heisenberg ferromagnetic mixed spin (S, σ) chains

The Schwinger-boson mean-field theory (SBMFT) and the linearized tensor renormalization group (LTRG) methods are complementarily applied to explore the thermodynamics of the quantum ferromagnetic mixed spin (S, σ) chains. It is found that the system has double excitations, i.e. a gapless and a gapped excitation; the low-lying spectrum can be approximated by ωk∼Sσ2(S+σ)Jk2 with J the ferromagnetic coupling; and the gap between the two branches is estimated to be △ ∼ J. The Bose-Einstein condensation indicates a ferromagnetic ground state with magnetization mtotz=N(S+σ). At low temperature, the spin correlation length is inversely proportional to temperature (T), the susceptibility behaviors as χ=a1∗1T2+a2∗1T, and the specific heat has the form of C=c1∗T−c2∗T+c3∗T32, with ai (i = 1, 2) and ci (i = 1, 2, 3) the temperature independent constants. The SBMFT results are shown to be in qualitatively agreement with those by the LTRG numerical calculations for S = 1 and σ = 1/2. A comparison of the LTRG results with the experimental data of the model material MnIINiII(NO2)4(en)2(en = ethylenediamine), is made, in which the coupling parameters of the compound are obtained. This study provides useful information for deeply understanding the physical properties of quantum ferromagnetic mixed spin chain materials.

The Proteasome Distinguishes between Heterotypic and Homotypic Lysine-11-Linked Polyubiquitin Chains.

SummaryProteasome-mediated degradation occurs with proteins principally modified with lysine-48 polyubiquitin chains. Whether the proteasome also can bind atypical ubiquitin chains, including those linked by lysine-11, has not been well established. This is critically important, as lysine-11 polyubiquitination has been implicated in both proteasome-mediated degradation and non-degradative outcomes. Here we demonstrate that pure homotypic lysine-11-linked chains do not bind strongly to the mammalian proteasome. By contrast, heterotypic polyubiquitin chains, containing lysine-11 and lysine-48 linkages, not only bind to the proteasome but also stimulate the proteasomal degradation of the cell-cycle regulator cyclin B1. Thus, while heterotypic lysine-11-linked chains facilitate proteasomal degradation, homotypic lysine-11 linkages adopt conformations that prevent association with the proteasome. Our data demonstrate the capacity of the proteasome to bind ubiquitin chains of distinct topology, with implications for the recognition and diverse biological functions of mixed ubiquitin chains.

Effects of different types of triglycerides on hepatic and renal function and lipometabolism of patients with acute necrotizing pancreatitis: a prospective study

Objective To investigate the effects of structured triglyceride (STG) and physical mixed medium chain/ long chain triglycerides (MCT/ LCT) on hepatic and renal function and lipometabolism of patients with acute necrotizing pancreatitis (ANP) . Methods The clinical data of 30 patients with ANP who were admitted to the PLA General Hospital between January 2012 and June 2014 were prospectively analyzed. A double-blind, randomized, controlled study was performed in 30 patients who were allocated into the experimental group (15 patients received STG) and the control group (15 patients received physical mixed MCT/ LCT) . All the patients received isometrical nitrogen and isocaloric parenteral nutrition more than 5 days. The levels of alanine transaminase (ALT) , aspartate transaminase (AST) , glutamyl-transpeptidase (GGT) , alkaline phosphatase (ALP) , creatinine (Cr) , blood urea nitrogen (BUN) , triglyceride (TG) and total cholesterol (TC) were assayed before nutritional support treatment and at day 1 , 3 and 5 after nutritional support therapy. The measurement data with normal distribution was presented as ±s. The skew distribution data were described as M (range) . The comparison between groups were evaluated with an independent sample t test or one-way ANOVA. The count data were analyzed using the chi-square test. Results A total of 30 patients were screened for eligibility. The levels of ALT, AST, GGT, ALP, Cr, BUN, TG and TC were changed within a certain range at day 1, 3 and 5 after nutritional support treatment. The levels of ALT, AST, GGT, ALP, Cr, BUN and TC before treatment and at day 5 after treatment were changed from 29. 0 U/ L, 25. 4 U/ L, 83.2 U/ L, (193 ± 115) U/ L, (124 ± 97) μmol/ L, (8 ±6) mmol/ L and (2.4 ± 1.1) mmol/ L to 29.4 U/ L, 33.0 U/ L, 77.7 U/ L, (172 ± 74) U/ L, (117 ± 103) μmol/ L, (8 ± 5) mmol/ L and (2.3 ± 1.0) mmol/ L in the experimental group, and from 23.8 U/ L, 22. 9 U/ L, 96. 2 U/ L, (148 ± 108) U/ L, (82 ± 57) μmol/ L, (9 ± 7) mmol/ L and (2.5 ± 0.7) mmol/ L to 21. 3 U/ L, 24. 5 U/ L, 127.4 U/ L, (179 ± 126) U/ L, (80 ± 54) μmol/ L, (10 ± 6) mmol/ L and (2.4 ± 0. 8 ) mmol/ L in the control group, respectively. There were no significant differences in the changing trends of the levels of ALT, AST, GGT, ALP, Cr, BUN and TC between the 2 groups (F =0.647, 1.186, 0.282, 0.553, 0.862, 0.182, 0.369, P >0.05) . The level of TG in the experimental group from pre-treatment to day 5 after treatment was changed from (1. 5 ± 0.6) mmol/ L to (1. 5 ± 0.7) mmol/ L, with increasing trend from pre-treatment to day 1 after treatment and reaching the normal level at day 3 and 5 after treatment. The level of TG in the control group from pre-treatment to day 5 after treatment was changed from (1.5 ± 0.6) mmol/ L to (2.4 ± 0. 6) mmol/ L, with increasing trend from pre-treatment to day 1 , 3 and 5 after treatments. There were significant differences in the changing trends of TG before and after nutritional support therapy between the 2 groups (F = 7.940, P <0.05) . Conclusion STG and physical mixed MCT/ LCT don't influence the hepatic and renal function of patients with ANP undergoing parenteral nutritional support therapy, while STG has a better effect of lipometabolism compared with physical mixed MCT/ LCT. Registry This study was registered with the UMIN Clinical Trial Registry with the registry number of UMI16958 Key words: Acute necrotizing pancreatitis; Nutritional support therapy; Structured triglyceride; Lipometabolism

Study of mechanical property of polyurethane composites for vibration isolator

This paper explores the influence of polycaprolactone, which is commonly used in the production of polyurethane, on the mechanical properties of polyurethane composites. Polycaprolactone with different molecular weights and mixed chain extenders with different mixing proportions were analysed for this study. The results show that a multi-formula system had advantages over a single-formula, in that, multi-formula systems created an optimal overall balance among all indices of mechanical properties, and provided optimised integration of comprehensive mechanical properties. Therefore, a multi-formula system approach can be adopted for polyurethane composites to satisfy usage requirements of a high-performance vibration isolator with respect to comprehensive mechanical properties, such as tensile, tear and creep properties.

Cutoff for nonbacktracking random walks on sparse random graphs

A finite ergodic Markov chain exhibits cutoff if its distance to stationarity remains close to 1 over a certain number of iterations and then abruptly drops to near 0 on a much shorter time scale. Discovered in the context of card shuffling (Aldous–Diaconis, 1986), this phenomenon is now believed to be rather typical among fast mixing Markov chains. Yet, establishing it rigorously often requires a challengingly detailed understanding of the underlying chain. Here, we consider nonbacktracking random walks on random graphs with a given degree sequence. Under a general sparsity condition, we establish the cutoff phenomenon, determine its precise window and prove that the cutoff profile approaches a remarkably simple, universal shape.

RuO4 catalyzed dihydroxylation for the synthesis of mixed medium-chain triacylglycerols

RuO4 catalyzed dihydroxylation of allyl acylates (C5 to C12) to glyceryl acylates is reported. The dihydroxylation was a major product (61–85%) with C5–C7 whereas carbonyl compounds by double bond fission were major with C8–C12 systems. 1-Hexanoylglycerol, obtained in high yields (85%), was further acylated with medium chain fatty acid chlorides to prepare mixed medium chain triglycerides (85–90%). Hence, a facile preparation of triacylglycerols such as C6–C6–C6, C6–C8–C8, C6–C10–C10, and C6–C12–C12 is accomplished.