Step Transition Research Articles

Drought indices supporting drought management in transboundary watersheds subject to climate alterations

There is growing concern in Iraq about the inefficiency of reactive drought management practices. Corresponding actions are largely characterized as emergency-based responses that treat the symptoms of drought rather than consider the vulnerability components associated with impacts. The Diyala watershed shared between Iraq and Iran has been used as an example transboundary river basin marked by ineffectiveness of drought management. The standardized precipitation index and the reconnaissance drought index were used to determine the historical meteorological drought episodes and analysis indicated climate change-induced alterations in the area. Spatiotemporal drought maps were drawn, which can be used for the identification of drought prone areas and assist with proactive planning. This paper discusses the underlying causes of the impairments of drought management policies, and the challenges and difficulties accompanying the governance of drought in Iraq. Given the influence of climate change and the upstream anthropogenic pressures, the time has come to adopt a gradual nation-wide transition step to drought risk planning incorporating a management approach at the transboundary scale. Moreover, the institutional and technical water vulnerability components associated with drought management should be considered in an integrated manner. The paper presents a generic technical template to support decision-makers in drought risk management.

Orbital ordering to orbital glass transition in spinel FeCr2−xAlxS4 (0 ⩽ x ⩽ 0.2)

The polycrystalline (PC) sample of FeCr2S4 displays orbital ordering around TOO ∼ 9 K, while single crystal sample shows orbital glass. In this paper, with the substitution of Al for Cr, a step by step transition from the orbital ordering to the orbital glass is reported in FeCr2−xAlxS4 (0 ⩽ x ⩽ 0.2). For PC FeCr2S4, the onset of long-range orbital order at TOO is evidenced by the appearance of a step-like transition in the temperature dependence of the magnetization (M(T)), a small kink at about 5.5 T below 9 K in the isotherms' magnetic field dependence of the magnetization (M(H)) curves as well as a λ-type anomaly in specific heat. With increasing Al content, the TOO decreases gradually. For the samples with x ⩾ 0.1, the orbital ordering is replaced by orbital glass, where the specific heat obeys a T2-dependence. The calculated residual orbital entropy consistently increases with x, implying the progressive freezing of the orbital moments and the coexistence of orbital ordering and orbital glass in the middle doping level.

Transcription cofactor PC4 plays essential roles in collaboration with the small subunit of general transcription factor TFIIE.

In eukaryotes, positive cofactor 4 (PC4) stimulates activator-dependent transcription by facilitating transcription initiation and the transition from initiation to elongation. It also forms homodimers and binds to single-stranded DNA and various transcriptional activators, including the general transcription factor TFIIH. In this study, we further investigated PC4 from Homo sapiens and the nematode Caenorhabditis elegans (hPC4 and cePC4, respectively). hPC4 strongly stimulated transcription on a linearized template, whereas it alleviated transcription on a supercoiled template. Transcriptional stimulation by PC4 was also alleviated by increasing the amount of TFIID. GST pull-down studies with general transcription factors indicated that both hPC4 and cePC4 bind strongly to TFIIB, TFIIEβ, TFIIFα, TFIIFβ and TFIIH XPB subunits and weakly to TBP and TFIIH p62. However, only hPC4 bound to CDK7. The effect of each PC4 on transcription was studied in combination with TFIIEβ. hPC4 stimulated both basal and activated transcription, whereas cePC4 primarily stimulated activated transcription, especially in the presence of TFIIEβ from C. elegans. Finally, hPC4 bound to the C-terminal region of hTFIIEβ adjacent to the basic region. These results indicate that PC4 plays essential roles in the transition step from transcription initiation to elongation by binding to melted DNA in collaboration with TFIIEβ.

The methyltransferase domain of dengue virus protein NS5 ensures efficient RNA synthesis initiation and elongation by the polymerase domain.

Viral RNA-dependent RNA polymerases (RdRps) responsible for the replication of single-strand RNA virus genomes exert their function in the context of complex replication machineries. Within these replication complexes the polymerase activity is often highly regulated by RNA elements, proteins or other domains of multi-domain polymerases. Here, we present data of the influence of the methyltransferase domain (NS5-MTase) of dengue virus (DENV) protein NS5 on the RdRp activity of the polymerase domain (NS5-Pol). The steady-state polymerase activities of DENV-2 recombinant NS5 and NS5-Pol are compared using different biochemical assays allowing the dissection of the de novo initiation, transition and elongation steps of RNA synthesis. We show that NS5-MTase ensures efficient RdRp activity by stimulating the de novo initiation and the elongation phase. This stimulation is related to a higher affinity of NS5 toward the single-strand RNA template indicating NS5-MTase either completes a high-affinity RNA binding site and/or promotes the correct formation of the template tunnel. Furthermore, the NS5-MTase increases the affinity of the priming nucleotide ATP upon de novo initiation and causes a higher catalytic efficiency of the polymerase upon elongation. The complex stimulation pattern is discussed under the perspective that NS5 adopts several conformations during RNA synthesis.

Fast Step Transition and State Identification (STaSI) for Discrete Single-Molecule Data Analysis.

We introduce a step transition and state identification (STaSI) method for piecewise constant single-molecule data with a newly derived minimum description length equation as the objective function. We detect the step transitions using the Student’s t test and group the segments into states by hierarchical clustering. The optimum number of states is determined based on the minimum description length equation. This method provides comprehensive, objective analysis of multiple traces requiring few user inputs about the underlying physical models and is faster and more precise in determining the number of states than established and cutting-edge methods for single-molecule data analysis. Perhaps most importantly, the method does not require either time-tagged photon counting or photon counting in general and thus can be applied to a broad range of experimental setups and analytes.

Trypsinogen activation as observed in accelerated molecular dynamics simulations.

Serine proteases are involved in many fundamental physiological processes, and control of their activity mainly results from the fact that they are synthetized in an inactive form that becomes active upon cleavage. Three decades ago Martin Karplus's group performed the first molecular dynamics simulations of trypsin, the most studied member of the serine protease family, to address the transition from the zymogen to its active form. Based on the computational power available at the time, only high frequency fluctuations, but not the transition steps, could be observed. By performing accelerated molecular dynamics (aMD) simulations, an interesting approach that increases the configurational sampling of atomistic simulations, we were able to observe the N-terminal tail insertion, a crucial step of the transition mechanism. Our results also support the hypothesis that the hydrophobic effect is the main force guiding the insertion step, although substantial enthalpic contributions are important in the activation mechanism. As the N-terminal tail insertion is a conserved step in the activation of serine proteases, these results afford new perspective on the underlying thermodynamics of the transition from the zymogen to the active enzyme.

Character of transitions causing the physicochemical aging of a sapric histosol

Physicochemical aging of soil organic matter is assured by the dynamic character of weak interactions stabilizing its supramolecular structure. However, aging is difficult to monitor, due to low organic matter content in most soils and relatively large time constants. In order to overcome those problems, a model soil, sapric histosol, was exposed to the accelerated aging after a short heating event to 110 °C, and its thermal characteristics were monitored over several months. Classical and temperature modulated differential scanning calorimetry, microcalorimetry and solid-state NMR were used to elucidate the character of involved transitions. The heating event caused separation of an initially broad transition into two processes; a melting, which showed almost no response on the previous heating and a step transition, which is associated with the disruption of water molecule bridges (WaMB) between molecular segments of organic matter. Both processes are preceded by a preparatory phase, starting at subambient temperatures, in which aliphatic domains probably recrystallize and water molecules condensate forming WaMB stabilizing the physical structure of sapric histosol. The aliphatic moieties showed a particular behavior reflected in higher imperfection in crystallite structure upon slow cooling, which was attributed to their interaction with surrounding porous and heterogeneous structures. The results show that soil organic matter aging, considered as a natural process driven by thermodynamic principles, is caused by successive development of WaMB. This is potentially accompanied by recrystallization of aliphatic structures and both processes lead to higher physicochemical stability of soil organic matter.

Genome-wide Functional Analysis Reveals Factors Needed at the Transition Steps of Induced Reprogramming

Although transcriptome analysis can uncover the molecular changes that occur during induced reprogramming, the functional requirements for a given factor during stepwise cell-fate transitions are left unclear. Here, we used a genome-wide RNAi screen and performed integrated transcriptome analysis to identify key genes and cellular events required at the transition steps in reprogramming. Genes associated with cell signaling pathways (e.g., Itpr1, Itpr2, and Pdia3) constitute the major regulatory networks before cells acquire pluripotency. Activation of a specific gene set (e.g., Utf1 or Tdgf1) is important for mature induced pluripotent stem cell formation. Strikingly, a major proportion of RNAi targets (∼ 53% to 70%) includes genes whose expression levels are unchanged during reprogramming. Among these non-differentially expressed genes, Dmbx1, Hnf4g, Nobox, and Asb4 are important, whereas Nfe2, Cdkn2aip, Msx3, Dbx1, Lzts1, Gtf2i, and Ankrd22 are roadblocks to reprogramming. Together, our results provide a wealth of information about gene functions required at transition steps during reprogramming.

Calcium-Doping for Structure Stabilization of Sodium Transition Metal Oxide Cathodes in Sodium Ion Batteries

NaNi0.5Mn0.5O2 (NNMO), which has a layered structure, is a promising cathode material for sodium ion batteries. The stack of Mn(Ni)O2 slabs in a layered structure of NaiNi0.5Mn0.5O2, are composed of edge-shared Mn(Ni)O6 octahedra, forming metal-occupied octahedral sites and empty tetrahedral sites. The octahedral sites in Na slabs are also occupied by Na+ ions, which are sandwiched by edge-sharing with Mn(Ni)O2 slabs. In this work, O3-CaxNa1-2x[Ni0.5Mn0.5]O2 (0 < x ≤ 0.1) was synthesized by incorporating Ca2+ into NaO6 layer of Na[Ni0.5Mn0.5]O2. Both the significant difference in ionic radii between Ca2+ (1.12Å) and Ni2+ (0.69Å) or Mn4+ (0.53 Å) and the reduction of Na+ content allowed the preparation of phase-pure and cation-mixing-free (i.e., absence of Ca2+ in transition metal oxide layers) CaxNa1-2x[Ni0.5Mn0.5]O2 up to x = 0.05. It was expected that, while no noticeable change was observed in a dimension of MnO6 octahedron, NaO6 octahedron continuously shrank as the increase of Ca2+ content. The latter effect was expected to prevent the structural degradation during repeated charge-discharge, eventually contributing to the improvement of capacity retention. Preliminary study indicated that, while pristine Na[Ni0.5Mn0.5]O2 showed a continuous decrease in discharge capacity, Ca0.05Na0.90[Ni0.5Mn0.5]O2 maintained a significant fraction of an initial capacity with a small capacity fading during 50 cycles. The excellent capacity retention of Ca2+-doped one is believed because the strong interaction of immobile Ca2+ with O2- helps restore of the initial O3 structure, which leads to the maintenance of distinctive phase transition steps on discharge profiles after repeated cycles in contrast to pristine one.

Step to step transition cost when walking with an energy storing and release prosthetic foot and SACH foot

s / Gait & Posture 39S (2014) S1–S141 S83 Table 1 Cohort information (height and mass including prostheses). Participant Age (yrs) Height (m) Mass (kg) Amputation level Time between fitting and Session 1 (days) Activity on limbs between Sessions 1 and 2 (h)

Klebsormidium flaccidum genome reveals primary factors for plant terrestrial adaptation.

The colonization of land by plants was a key event in the evolution of life. Here we report the draft genome sequence of the filamentous terrestrial alga Klebsormidium flaccidum (Division Charophyta, Order Klebsormidiales) to elucidate the early transition step from aquatic algae to land plants. Comparison of the genome sequence with that of other algae and land plants demonstrate that K. flaccidum acquired many genes specific to land plants. We demonstrate that K. flaccidum indeed produces several plant hormones and homologues of some of the signalling intermediates required for hormone actions in higher plants. The K. flaccidum genome also encodes a primitive system to protect against the harmful effects of high-intensity light. The presence of these plant-related systems in K. flaccidum suggests that, during evolution, this alga acquired the fundamental machinery required for adaptation to terrestrial environments.

Kinematic differences exist between transtibial amputee fallers and non-fallers during downwards step transitioning.

Stair negotiation is biomechanically more challenging than level gait. There are few biomechanical assessments of transtibial amputees descending stairs and none specifically related to falls. Stair descent may elicit more differences than level gait in amputees with and without a previous falls history. The aim of this study was to compare the gait kinematics of fallers and non-fallers during downwards step transitioning in transtibial amputees. Cross-sectional study. Six fallers and five non-fallers completed step transition trials on a three-step staircase at their self-selected pace. Nine participants exhibited a clear preference to lead with the affected limb, while two had no preference. Four participants self-selected a step-to rather than a reciprocal stair descent strategy. The fallers who used a reciprocal strategy walked 44% more quickly than the non-fallers. To compensate for the lack of active plantar flexion of the prosthetic foot, exaggerated range of motion occurred proximally at the pelvis during swing. The step-to group was more reliant on the handrails than the reciprocal group and walked more slowly. As anticipated, the fallers walked faster than the non-fallers despite employing the more difficult 'roll-over' technique. Handrail use could help to improve dynamic control during downwards step transitions. Transtibial amputees are advised to descend steps using external support, such as handrails, for enhanced dynamic control. Hip abductor and knee extensor eccentric strength should be improved through targeted exercise. Prosthetic socket fit should be checked to allow adequate knee range of motion on the affected side.

Transition of electrical conductivity in carbon nanotube/silver particle composite buckypapers

The electrical conductivity of carbon nanotube buckypapers can be dramatically increased by incorporation of silver particles contained in a commercial silver paste. Two methods, co-dispersion during the production of buckypaper and surface coating on a preformed buckypaper, were used to prepare composite buckypapers. The two types of composite buckypapers exhibited very different electrical conductivity profiles. The composite buckypapers prepared by the surface coating method showed a distinct step transition in electrical conductivity at 3vol% silver content, leading to a 15-fold improvement at 6% silver content. The composite buckypapers prepared by the co-dispersion method showed a gradual change in electrical conductivity with increasing silver particle content, resulting in a five-fold improvement at 12% silver content. Surface and sectional morphologies of the two types of composite buckypapers were examined and related to their electrical conductivity profiles.

Magnetization reversal and dynamics in non-interacting NiFe mesoscopic ring arrays

The dynamics of magnetization (M) reversal and relaxation as a function of temperature (T) are reported in three non-interacting NiFe ring arrays having fixed ring outer diameter and varying widths. Additionally, the dependence of M(H) loop on the angle (θ) between magnetic field (H) and the plane of the rings is addressed. The M(H) loops show a double step transition from onion state (OS) to vortex state (VS) at all temperatures (T = 3 to 300 K) and angles (θ = 0 to 90°). The critical reversal fields HC1 (OS to VS) and HC2 (VS to OS) show a pronounced dependence on T, ring width, and θ. Estimation of the transverse and vortex domain wall energies reveals that the latter is favored in the OS. The OS is also the remanent state in the smallest rings and decays with the effective energy scale (U0/T) of 50 and 32 meV/K at 10 and 300 K, respectively. The robust in-plane anisotropy of magnetization of ring assemblies is established by scaling the M(H) with θ.

ПРОГРАММНО-МЕТОДИЧЕСКИЕ АСПЕКТЫ ФОРМИРОВАНИЯ КОМПЕТЕНЦИЙ СТУДЕНТОВ В ОБЛАСТИ ОБРАЗОВАТЕЛЬНОГО МАРКЕТИНГА

Marketing introduction in the field of education is capable to make a beneficial im-pact both on experts of education, and on consumers of their production. Marketing appli-cation for education is represented as an actual scientifically reasonable way of ensuring successful activity of an educational institution. Having established interrelation between labour market and needs of the personality, the educational institution is able to create a complex of competitive services demanded by the market of educational services. The de-velopment of the market of educational services foregrounds the problem of the definition of aspects of formation of educational marketing and carrying out market researches in the field of education. For producers of services, including educational, the degree of commit-ment to marketing as a market philosophy is embodied in the degree, transition step supply-side orientation of the company to market, marketing orientation. The necessity to increase the effectiveness of management in the sphere of education, search of innovative methods led to the use of marketing as a way of integrated management of production and sale of educational services which are understood as a complex of the services focused on realiza-tion of main objectives of education that allows to give the definition of educational mar-keting as the process of production and realization of educational services in the system of education, the demand based on consumers’ needs and satisfaction of this demand. The realization of marketing technologies assumes focusing on such factors as the demand in educational services, the latest achievements in science and technology, the use of effective methods, technologies and tutorials, individualization of training, the mobility of training allowing to change character quickly, the contents and terms of training and quantity of students. In this article some aspects of realization of the policy in the field of educational marketing are considered. The model of formation of marketing culture of future specialists of preschool institutions on the example of a special course "Marketing in preschool educa-tion" which approbation was carried out in 2012-2014 in educational establishments "Bara-novichi State University" (The Republic of Belarus) is offered. Key words: educational marketing, marketing readiness, marketing culture, marketing activ-ity.

Distribution, Transition and Thermodynamic Stability of Protein Conformations in the Denaturant-Induced Unfolding of Proteins

BackgroundExtensive and intensive studies on the unfolding of proteins require appropriate theoretical model and parameter to clearly illustrate the feature and characteristic of the unfolding system. Over the past several decades, four approaches have been proposed to describe the interaction between proteins and denaturants, but some ambiguity and deviations usually occur in the explanation of the experimental data.Methodology/Principal FindingsIn this work, a theoretical model was presented to show the dependency of the residual activity ratio of the proteins on the molar denaturant concentration. Through the characteristic unfolding parameters k i and Δm i in this model, the distribution, transition and thermodynamic stability of protein conformations during the unfolding process can be quantitatively described. This model was tested with the two-state unfolding of bovine heart cytochrome c and the three-state unfolding of hen egg white lysozyme induced by both guanidine hydrochloride and urea, the four-state unfolding of bovine carbonic anhydrase b induced by guanidine hydrochloride and the unfolding of some other proteins induced by denaturants. The results illustrated that this model could be used accurately to reveal the distribution and transition of protein conformations in the presence of different concentrations of denaturants and to evaluate the unfolding tendency and thermodynamic stability of different conformations. In most denaturant-induced unfolding of proteins, the unfolding became increasingly hard in next transition step and the proteins became more unstable as they attained next successive stable conformation.Conclusions/SignificanceThis work presents a useful method for people to study the unfolding of proteins and may be used to describe the unfolding and refolding of other biopolymers induced by denaturants, inducers, etc.

Tet and TDG Mediate DNA Demethylation Essential for Mesenchymal-to-Epithelial Transition in Somatic Cell Reprogramming

Tet-mediated DNA oxidation is a recently identified mammalian epigenetic modification, and its functional role in cell-fate transitions remains poorly understood. Here, we derive mouse embryonic fibroblasts (MEFs) deleted in all three Tet genes and examine their capacity for reprogramming into induced pluripotent stem cells (iPSCs). We show that Tet-deficient MEFs cannot be reprogrammed because of a block in the mesenchymal-to-epithelial transition (MET) step. Reprogramming of MEFs deficient in TDG is similarly impaired. The block in reprogramming is caused at least in part by defective activation of key miRNAs, which depends on oxidative demethylation promoted by Tet and TDG. Reintroduction of either the affected miRNAs or catalytically active Tet and TDG restores reprogramming in the knockout MEFs. Thus, oxidative demethylation to promote gene activation appears to be functionally required for reprogramming of fibroblasts to pluripotency. These findings provide mechanistic insight into the role of epigenetic barriers in cell-lineage conversion.

A Gene Expression and Pre-mRNA Splicing Signature That Marks the Adenoma-Adenocarcinoma Progression in Colorectal Cancer

It is widely accepted that most colorectal cancers (CRCs) arise from colorectal adenomas (CRAs), but transcriptomic data characterizing the progression from colorectal normal mucosa to adenoma, and then to adenocarcinoma are scarce. These transition steps were investigated using microarrays, both at the level of gene expression and alternative pre-mRNA splicing. Many genes and exons were abnormally expressed in CRAs, even more than in CRCs, as compared to normal mucosae. Known biological pathways involved in CRC were altered in CRA, but several new enriched pathways were also recognized, such as the complement and coagulation cascades. We also identified four intersectional transcriptional signatures that could distinguish CRAs from normal mucosae or CRCs, including a signature of 40 genes differentially deregulated in both CRA and CRC samples. A majority of these genes had been described in different cancers, including FBLN1 or INHBA, but only a few in CRC. Several of these changes were also observed at the protein level. In addition, 20% of these genes (i.e. CFH, CRYAB, DPT, FBLN1, ITIH5, NR3C2, SLIT3 and TIMP1) showed altered pre-mRNA splicing in CRAs. As a global variation occurring since the CRA stage, and maintained in CRC, the expression and splicing changes of this 40-gene set may mark the risk of cancer occurrence from analysis of CRA biopsies.

Improving solar radiation absorbance of high refractory sintered ceramics by fs Ti:sapphire laser surface treatment

Samples of high refractory pressure-less sintered carbide ceramics (HfC based), polished by mechanical grinding to a surface roughness Ra∼40nm, have been surface treated, in vacuum, by fs Ti:sapphire laser, operating at 800nm wavelength, 1000Hz repetition rate and 100fs pulse duration, at fluence varying in the range (∼6–25J/cm2), to optimize their solar radiation absorbance, in such a way that they could operate as absorber material in an innovative conversion module of solar radiation into electrical energy. To this aim, an area of approximately 9.6cm2 was treated by the fs laser beam. The beam strikes perpendicular to the sample, placed on a stage set in motion in the x, y, z-directions, thus generating a scanning pattern of parallel lines. The experimental conditions of laser treatment (energy fluence, speed of transition, overlapping and lateral step distance) were varied in order to optimize the radiation absorption properties of the patterned surface. In laser treated samples the absorption value is increased by about 15%, compared to the original untreated surface, up to a value of final absorbance of about 95%, all over the range of solar radiation spectrum (from UV to IR). The morphological and chemical effects of the treatment have been evaluated by SEM–EDS analysis. At very high fluence, we obtained the characteristic ablation craters and local material decomposition, while at lower fluence (in any case above the threshold) typical periodic nano-structures have been obtained, exploitable for their modified optical properties.

Making the case for directed organ donation to registered donors in Israel

BackgroundThe number of deceased donor organ donations in Israel is lower than average when compared to other Western World countries. To address the organ gap, the 2008 Organ Transplantation Law provides new interventions, including important incentives to donors (and their families). The most notable of these was granting priority to registered donors (i.e., people on the waiting list who signed a donor card). The current study presents the normative arguments as well as the first documentation of public attitudes in Israel towards another possible incentive – allowing individuals to influence the allocation of their organs by permitting them to designate, to direct their donated organs [DD] to other registered donors, instead of the current allocation based primarily on medical criteria.MethodsA structured phone survey of 695 Israelis was conducted during Feb-March 2012. The sample is representative of the Israeli society in terms of age mix and gender, with adequate representation of the Arab and ultra-orthodox Jewish subgroups.ResultsAmong all Israelis, 68% stated a willingness to donate their organs, but only 16% reported to have already signed a donor card. 85% stated their interest in receiving an organ if the need arises. Overall, 64% of respondents felt that DD to a group of others who have registered as donors is justified, and the rate was remarkably higher in the Arab group (84%), and lower in the religious and ultraorthodox Jewish groups (52% and 50% respectively).ConclusionsThe majority of the Israeli public supports organ donation and its proven benefits. Thus, organ recovery policy should be grounded in a strong communitarian strategy as we all stand to benefit from cooperation. However, current legislation and practices are modeled on individual disposition based on an opt-in legal framework. DD allows personal choices of to-be donors that might interfere with social interests, principles, and values such as equal access to care (i.e. organs) or justice. However, based on the result of this survey, the conceptual case of DD to other registered donors should be viewed more favorably (while the details should be addressed in future analyses), as DD is not expected to be rejected by the public at the outset. From a normative perspective, it is possible to support an allocation scheme that allows DD to other registered donors, where individual preferences that promote just sharing of the burden (donating organs) as well as the benefits (receiving an organ) of transplantation medicine are respected. Yet, DD to other registered donors should be understood and portrayed as a transition step towards a more communitarian model, and as a signal of solidarity by sharing organs as a public good rather than as an exercise of a quasi-property right.