Instability Index Values Research Articles

Ekstremalne wartości wskaźników chwiejności atmosfery w Polsce i ich związek z mechanizmami ograniczającymi rozwój konwekcji

The primary goal of the study was to examine the temporal and spatial variability of values of selected atmospheric instability indices over Poland for the period 2005–2014. The research involved six indices most frequently applied in convection forecasting – Convective Available Potential Energy, K-Index, Lifted Index, Severe Weather Threat Index, Showalter Index and Total Totals Index. The data from three Polish upper air sounding stations ( Łeba, Legionowo, Wroclaw ), as well as SYNOP codes on present and past weather and reports on severe meteorological phenomena from the European Severe Weather Database were used in this study. It was found that extremely high values of the selected indices were characterised by strong temporal and spatial variability. Moreover, a detailed analysis of the days when no convective events were observed, despite extreme values of instability indices, demonstrated that the occurrence of isothermal or inversion layers were the most common mechanisms inhibiting the development of severe convective phenomena. Convection was also inhibited when the area was free from an influence of atmospheric fronts, convergence zones or low-pressure troughs.

Comparison of instability indices from COSMO-I7 and ECMWF-IFS analyses over the Piedmont Region, Italy, and new modifications to theKIndex

This paper presents a statistical analysis of heavy rain events recorded by the high resolution network of ARPA Piemonte (Piedmont Region Environmental Protection Agency) rain gauges between 2007 and 2014. In order to define convective heavy rain events over the region, a rainfall threshold of 10 mm in 20 min was chosen. Events were sampled at intervals of 6 h for the warning areas of the Piedmont Region, Italy, and their distribution was studied in relation to the values of instability indices obtained from the European Centre for Medium Range Weather Forecasts Integrated Forecasting System and the COnsortium for Small-scale MOdeling (COSMO)-I7 operational analyses. The performances of the indices of the two meteorological models were investigated for the different warning areas in a pseudo-operational weather forecasting context, obtaining useful information in the phase of issuing thunderstorm early warnings. The second part of the work had the goal of improving the performance of these indices, modifying the one that showed better verification results in terms of receiver operating characteristic (ROC) area increase and the K Index (KI). This was done by introducing dependences on the thickness of geopotential height and wind direction at different levels. KI modifications that displayed better results were called reduced K Index (KR), obtained by dividing KI by the thickness of geopotential height between 500 and 850 hPa, and KW, obtained by adjusting the KR value with additive constants depending on the wind direction at different levels. KW in particular led to a net improvement of the performance of the original KI over the region.

Genome-wide identification and comparative structural analysis of RuBisCo proteins in the asteraceae

Asteraceae, the largest known plant family in the world, contains economically important species including ornamental plants. The most abundant enzyme on Earth, Ribulose-1,5-bisphosphate (RuBisCo), catalyzes the first step of carbon assimilation in photosynthesis. In this study, we conducted sequence, physicochemical, phylogenetic, and three-dimensional comparative analyses of 22 RuBisCo proteins in the Asteraceae using various bioinformatic tools. The alignment results showed that all residues corresponding to the region between 48-179 amino acids were conserved in all species, except for just seven residues: G79, I80, S88, F90, F93, I135, and S136. The sequence lengths of the RuBisCo large subunits were between 163 and 477 amino acids, with an average length of 255 amino acids. Their molecular weights (Mw) ranged from 18341.8 to 52895.1 Da, with an average Mw of 26294.5 Da. We found that the most abundant amino acid residue was Gly, which comprised 9.88% of these RuBisCo proteins. Ala (8.17%) and Leu (8.53%) were also both abundant. The extinction coefficient of the RuBisCo proteins at 280 nm ranged from 27515 to 69830 M-1 cm-1. The instability index values ranged from 24.41 to 40.65, and only one protein (from Gymnarrhena micrantha) was unstable in vitro. The aliphatic index values ranged from 72.56 to 81.13, while the GRAVY values ranged from -0.394 to -0.179. A total of ten motifs were identified in the sequences of the RuBisCo proteins. Phylogenetic analysis revealed that the 22 RuBisCo proteins formed two main clades. A RAMPAGE analysis revealed that 95.0-98.4% of residues were located in the favored region in 22 RuBisCo proteins. Sequence alignment and 3D analysis revealed that a catalytically important Lys residue was conserved among all the RuBisCo enzymes of Asteraceae. The results of this study provide insights into the fundamental characteristics of the RuBisCo proteins of the Asteraceae.

2012년 겨울철 특별관측자료를 이용한 강수현상 시 대기 연직구조와 민감도 실험

This study analyzed the synoptic distribution and vertical structure about four cases of precipitation occurrences using NCEP/NCAR reanalysis data and upper level data of winter intensive observation to be performed by National Institute of Meteorological Research at Bukgangneung, Incheon, Boseong during 63days from 4 JAN to 6 MAR in 2012, and Observing System Experiment (OSE) using 3DVAR-WRF system was conducted to examine the precipitation predictability of upper level data at western and southern coastal regions. The synoptic characteristics of selected precipitation occurrences were investigated as causes for 1) rainfall events with effect of moisture convergence owing to low pressure passing through south sea on 19 JAN, 2) snowfall events due to moisture inflowing from yellow sea with propagation of Siberian high pressure after low pressure passage over middle northern region on 31 JAN, 3) rainfall event with effect of weak pressure trough in west low and east high pressure system on 25 FEB, 4) rainfall event due to moisture inflow according to low pressures over Bohai bay and south eastern sea on 5 MAR. However, it is identified that vertical structure of atmosphere had different characteristics with heavy rainfall system in summer. Firstly, depth of convection was narrow due to absence of moisture convergence and strong ascending air current in middle layer. Secondly, warm air advection by veering wind with height only existed in low layer. Thirdly, unstable layer was limited in the narrow depth due to low surface temperature although it formed, and also values of instability indices were not high. Fourthly, total water vapor amounts containing into atmosphere was small due to low temperature distribution so that precipitable water vapor could be little amounts. As result of OSE conducting with upper level data of Incheon and Boseong station, 12 hours accumulated precipitation distributions of control experiment and experiments with additional upper level data were similar with ones of observation data at 610 stations. Although Equitable Threat Scores (ETS) were different according to cases and thresholds, it was verified positive influence of upper level data for precipitation predictability as resulting with high improvement rates of 33.3% in experiment with upper level data of Incheon (INC_EXP), 85.7% in experiment with upper level data of Boseong (BOS_EXP), and 142.9% in experiment with upper level data of both Incheon and Boseong (INC_BOS_EXP) about accumulated precipitation more than 5 mm / 12 hours on 31 January 2012.

Sequence analysis and homology modeling of peroxidase from Medicago sativa.

Plant peroxidases are one of the most extensively studied group of enzymes which find applications in the environment, health, pharmaceutical, chemical and biotechnological processes. Class III secretary peroxidase from alfalfa (Medicago sativa) has been characterized using bioinformatics approach Physiochemical properties and topology of alfalfa peroxidase were compared with that of soybean and horseradish peroxidase, two most popular commercially available peroxidase preparations. Lower value of instability index as predicted by ProtParam and presence of extra disulphide linkages as predicted by Cys_REC suggested alfalfa peroxidase to be more stable than either of the commercial preparations. Multiple Sequence Alignment (MSA) with other functionally similar proteins revealed the presence of highly conserved catalytic residues. Three dimensional model of alfalfa peroxidase was constructed based on the crystal structure of soybean peroxidase (PDB Id: 1FHF A) by homology modelling approach. The model was checked for stereo chemical quality by PROCHECH, VERIFY 3D, WHAT IF, ERRAT, 3D MATCH AND ProSA servers. The best model was selected, energy minimized and used to analyze structure function relationship with substrate hydrogen peroxide by Autodock 4.0. The enzyme substrate complex was viewed with Swiss PDB viewer and one residue ASP43 was found to stabilize the interaction by hydrogen bonds. The results of the study may be a guiding point for further investigations on alfalfa peroxidase.

Cardiorespiratory instability before and after implementing an integrated monitoring system*

Cardiorespiratory instability may be undetected in monitored step-down unit patients. We explored whether using an integrated monitoring system that continuously amalgamates single noninvasive monitoring parameters (heart rate, respiratory rate, blood pressure, and peripheral oxygen saturation) into AN instability index value (INDEX) correlated with our single-parameter cardiorespiratory instability concern criteria, and whether nurse response to INDEX alert for patient attention was associated with instability reduction. Prospective, longitudinal evaluation in sequential 8-, 16-, and 8-wk phases (phase I, phase II, and phase III, respectively). A 24-bed trauma step-down unit in single urban tertiary care center. All monitored patients. Phase I: Patients received continuous single-channel monitoring (heart rate, respiratory rate, blood pressure, and peripheral oxygen saturation) and standard care; INDEX background was recorded but not displayed. Phase II: INDEX was background-recorded; staff was educated on use. Phase III: Staff used a clinical response algorithm for INDEX alerts. Any monitored parameters even transiently beyond local cardiorespiratory instability concern triggers (heart rate of <40 or >140 beats/min, respiratory rate of <8 or >36 breaths/min, systolic blood pressure of <80 or >200 mm Hg, diastolic blood pressure of >110 mm Hg, and peripheral oxygen saturation of <85%) defined INSTABILITYmin. INSTABILITYmin further judged as both persistent and serious defined INSTABILITYfull. The INDEX alert states were defined as INDEXmin and INDEXfull by using same classification. Phase I and phase III admissions (323 vs. 308) and monitoring (18,258 vs. 18,314 hrs) were similar. INDEXmin and INDEXfull correlated significantly with INSTABILITYmin and INSTABILITYfull (r = .713 and r = .815, respectively, p < .0001). INDEXmin occurred before INSTABILITYmin in 80% of cases (mean advance time 9.4 ± 9.2 mins). Phase I and phase III admissions were similarly likely to develop INSTABILITYmin (35% vs. 33%), but INSTABILITYmin duration/admission decreased from phase I to phase III (p = .018). Both INSTABILITYfull episodes/admission (p = .03) and INSTABILITYfull duration/admission (p = .05) decreased in phase III. The integrated monitoring system INDEX correlated significantly with cardiorespiratory instability concern criteria, usually occurred before overt instability, and when coupled with a nursing alert was associated with decreased cardiorespiratory instability concern criteria in step-down unit patients.

An implementation of rock engineering system for ranking the instability potential of natural slopes in Greek territory. An application in Karditsa County

This paper presents an application of rock engineering system (RES) in an attempt to reveal and assess the inherent instability potential of 388 sites where equivalent landslides have been manifested and recorded in the region of Karditsa County, Greece. The main objective has been defining the principal causative and triggering factors responsible for the manifestation of landslide phenomena, quantify their interactions, obtain their weighted coefficients, and calculate the instability index, which refers to the inherent potential instability of each natural slope of the examined region. From the statistical interpretation of the data reported in a well-documented database and concerning the examined failure sites, a clear correlation between the instability index and the area affected by a single landslide event has been revealed. Almost the entire failure sites, 98% of the examined slope sites, exhibit an instability index value over 55, a value which is thought to be a critical threshold for landslide manifestation concerning natural slopes in Karditsa County. It is argued that the presented RES methodology, engaging the selected set of parameters, could be considered as an effective expert's tool for ranking, in an objectively optimal and simple way, the instability potential of natural slopes in Karditsa County, and thus providing a tool for sound zoning landslide hazard.

Doping mechanism of optical-damage-resistant ions in lithium niobate crystals

Abstract The doping mechanism of optical-damage-resistant ions (Mg 2+ , Zn 2+ , In 3+ , Sc 3+ , Hf 4+ , and Zr 4+ ) in the lithium niobate crystallographic frame is quantitatively studied from the chemical bond viewpoint. Calculated results show that optical-damage-resistant ions have a strong interaction with the lithium niobate matrix, which is quantitatively evaluated by the deviation between normal and calculated valence states and the global instability index. All optical-damage-resistant ions first substitute Nb Li and then Li ions, they change their dopant occupancies from Li to Nb sites at the same global instability index value 0.1055. On the basis of such a quantitative interaction, the doping mechanism of these ions is finally derived. Furthermore, a criterion in searching for new optical-damage-resistant ions is also proposed.

Papillary thyroid cancer: high inter-(simple sequence repeat) genomic instability in a typically indolent cancer.

The object of this study is to measure genomic instability in papillary thyroid cancer and correlate these measurements with known clinical prognosticators such as patient age, tumor size, histologic subtype, and three commonly used thyroid risk assessment indices. A secondary objective of this study was to use the measurements of genomic instability to estimate the number of mutational events present in the papillary thyroid cancer genome. Inter-simple sequence repeat polymerase chain reaction (ISSR-PCR) is a rapid and reproducible technique for quantitation of genomic instability, or the degree of genome alteration, in solid tumors. This includes quantitation of amplifications, deletions, translocations, and insertions. Twenty-eight papillary carcinomas were evaluated by ISSR-PCR. Evaluation of 28 papillary carcinomas by ISSR-PCR demonstrated a wide range of genomic instability. Of the panel of clinicopathologic factors examined, only patient age was significantly associated with genomic instability. The mean genomic instability index value was greatest in the youngest age group, which was significantly different from the median value measured in the oldest age group (3.7, 2.5, respectively, p =.05). The mean value in the intermediate age group fell between the younger and older groups (3.1). By use of ISSR-PCR, we have calculated 15,000 individual genomic events as having occurred in each papillary tumor cell. Despite its generally indolent biologic behavior, papillary thyroid cancer exhibits a high degree of genomic instability comparable to that seen in colorectal cancer. These results suggest that elevated genomic instability, as measured by ISSR-PCR, may not be sufficient to enable thyroid tumor progression to less indolent disease and that this process is severely constrained by some additional essential factor such as the differentiated state of the tissue or the need to bring into play an additional form of genomic destabilization.

Application of inter-simple sequence repeat PCR to mouse models: assessment of genetic alterations in carcinogenesis.

Genomic instability is believed to play a significant role in cancer development by facilitating tumor progression and tumor heterogeneity. Inter-simple sequence repeat (inter-SSR) PCR has been proved to be a fast and reproducible technique for quantitation of genomic instability (amplifications, deletions, translocations, and insertions) in human sporadic tumors. However, the use of inter-SSR PCR in animal models of cancer has never been described. This new technique has been adapted in our laboratory for the analysis of spontaneous and induced mouse tumors. We established the best PCR conditions for each microsatellite-anchored primer and critically evaluated the reproducibility of the band patterns. We also studied the variation of the fingerprints between and within various inbred mouse strains, including wild-derived lines. Tumor-specific alterations were detected as gains, losses, or intensity changes in bands when compared with matched normal DNA. We quantitated the extent of alterations by dividing the number of altered bands in the tumor by the total number of bands in normal DNA (instability index). By means of inter-SSR PCR, we successfully analyzed genomic alterations in various mouse tumors, including spontaneous thymic lymphomas developed in Msh2 knockout mice as well as chemically induced squamous cell carcinomas and thymic lymphomas. Instability index values ranged between 0 and 9%, the highest levels observed in N-methyl-N-nitrosourea-induced thymic lymphomas generated in Trp53 (p53) nullizygote (-/-) mice. We report here, for the first time, the use of inter-SSR PCR to detect somatic mutations in mouse tumoral DNA, including laser-capture microdissected, methanol-fixed tissues. These PCR-based fingerprints provide a novel approach to assessing the number and onset of mutational events in mouse tumors and will help to understand better the mechanisms of carcinogenesis in mouse models.

Application of Bond Valence Model to Stability of RE Oxycompounds

The bond valence model was used to study the stability of the non-stoichiometric LaO1_,xF1+2x phases, the solid solubility in the (La1_ xGd )OCl system and the phase transformation in the REOCl (RE3+ =La3+—Nd3+, Sm 3+—Gd Ho and Y ) series. The stability of the non-stoichiometric LaO1_xF1+2x (0 < x < 0.3) phase decreases with increasing excess fluoride. The global instability index values close to 0.2 indicate the instability of the non-stoichiometric phase. The relative stability of the (La1_ x Gdx )OCl (0 < x < 1.0) solid solutions achieved its minimum in the middle of the series. However, the X-ray powder diffraction results indicated complete solid solubility in the whole (La1_ x Gdx )OCl series and no phase separation was observed. The bond valence model was used to explain the structural transformation from the tetragonal oxychlorides, REOCl (RE = La—Er, and Y), to hexagonal beyond ErOCI. The calculated global instability index values did not show any clear trend across the REOCl series probably due to the inaccuracies and incoherencies in the original structural data.

P53 tumor suppressor gene status and the degree of genomic instability in sporadic colorectal cancers.

Genomic instability reflects the propensity and the susceptibility of the genome to acquire multiple alterations and, in turn, is believed to be a driving force behind multistep carcinogenesis. Although the molecular basis of genomic instability in sporadic colorectal cancers remains largely a mystery, mutation of the p53 tumor suppressor gene (also known as TP53) has been proposed to play an integral role in this process. However, a dilemma exists in that p53 mutation appears to be a late event in the progression of sporadic colorectal tumors, whereas genomic instability, serving as a facilitator of tumor progression, is envisioned as occurring early in this process. We evaluated the relationship between p53 mutation and the major form of genomic instability in sporadic colorectal tumors, namely, that involving DNA breakage, which leads to chromosomal translocations, insertions, deletions, and gene amplification. Fifty-eight sporadic colorectal tumors that had been previously evaluated for genomic instability were analyzed for p53 mutations. These tumors were from consecutively diagnosed patients. Genomic instability was quantified by use of inter-simple sequence repeat polymerase chain reaction analysis that employed (CA)8RG and (CA)8RY primers (R = purine [A or G]; Y = pyrimidine [C or T]); a genomic instability index (a measure of the number of alterations in tumor DNA in comparison with normal DNA, expressed as a percent) was calculated for each tumor. Mutation of the p53 gene in exons 5-9 was determined by use of single-strand conformational polymorphism-polymerase chain reaction analysis and DNA sequencing. Chi-squared analysis was used to determine the statistical significance of differences between groups of tumors. Reported P values are two-sided. p53 mutations were identified in 29 (50%) of the 58 tumors. The median genomic instability index value was 3.3%. Nineteen (65.5%) of the 29 tumors with p53 mutations had genomic instability indices that were less than the median value (range, 0%-2.6%); the remaining 10 (34.5%) tumors had genomic instability indices that were greater than the median (range, 3.9%-13.0%). Eleven (37.9%) of the 29 tumors with wild-type p53 genes had genomic instability indices that were less than the median value (range, 0%-2.6%), whereas the remaining 18 tumors had genomic instability indices above the median (range, 3.9%-11.7%). There was a statistically significant association between a lesser degree of genomic instability and the presence of p53 mutations (P = .032). Tumors with no or minimal evidence of genomic instability are more likely to harbor p53 mutations than tumors with evidence of substantial genomic instability. p53 mutations play an important role in the development of cancers but do not appear to initiate or promote genomic instability in sporadic colorectal tumors.

A fuzzy approach in the determination of unstable machines

The aim of this paper is to present a fuzzy approach in the determination of the unstable machines in transient stability studies of multimachine electric power systems. This approach is based on the derivation of an index that can identify the unstable machine by using the values of the generator rotor angles and accelerations. The index actually computes the degree of instability of every system machine, when a three-phase fault is established on any power system location, causing no topological changes after its clearance. The unstable machine will be the one having the largest value of instability index. The derivation of this index is based on the principles of pattern recognition, fuzzy sets theory and the Taylor series expansion technique. Two examples illustrating the methods application are given, including the analysis of the interconnected Hellenic power system.