Indicator Of Structural Changes Research Articles

Physical characterization of freeze-dried foam prepared from aloe vera gel and guar gum

Background: Foams are colloidal dispersions of a gas suspended in a dispersing phase, which consisting of a semi-freeze-dried or viscous liquid phase. The physical properties of food foams are the result of the bubble characteristics and their spatial arrangement. Objectives: The aim of this work was to obtain foams of A. vera gel and guar gum and describe the changes in their physical properties and microstructure during freeze-drying using the fractal dimension concept and image analysis techniques. Methods: The porosity, density, and volume expansion factor of the fresh foams that were based on the A. vera foams were determined. The kinetics of foam texture, color, porosity and microstructure of the freeze-dried foams were obtained. The fractal texture dimension of surface (FDSDBC) and microstructure (FDESEM) of the foams were determined as indicators of structural changes after freeze-drying. The guar gum concentrations used to obtain the A. vera prefoam were expressed in w/w as F1 (control simple without gum), F2 (2%), F3 (4%) and F4 (6%). Results: We obtained stable freeze-dried foams of Aloe vera gel and guar gum. The porosity, density and volume expansion factor of the fresh and freeze-dried foams were affected by the addition of the guar gum. Changes in the topology of the freeze-dried foam surface during the drying process resulted in a high rugosity compared with the original smooth surface. The microstructure of the dried foam samples suggested a relationship between the gum concentration of the prefoam A. vera gel mixture and the physical properties before and after freeze-drying, such as an increase in the microstructural alterations and surface roughness during freeze-drying. The roughness of the freeze-dried foam surface, described by the FDSDBC represented the macroscopic physical changes of the samples and correlated with the changes in the foam microstructure, which were described by the fractal dimension of the Environmental Scanning Electron Microscopy ESEM microphotographs (FDESEM). Conclusions: The digital analysis of the structure and porosity of the freeze-dried foam can be used to quantify the effect of gum concentrations on the morphological features and physical properties of foams during freeze-drying.

Application of biospeckles for assessment of structural and cellular changes in muscle tissue

A modified spatial-temporal speckle correlation technique for operational assessment of structural changes in muscle tissues after slaughtering is considered. Coefficient of biological activity as a quantitative indicator of structural changes of biochemical processes in biological tissues is proposed. The experimental results have shown that this coefficient properly evaluates the biological activity of pig and chicken muscle tissue samples. Studying the degradation processes in muscle tissue during long-time storage in a refrigerator by measuring the spatial-temporal dynamics of biospeckle patterns is carried out. The reduction of the bioactivity level of refrigerated muscle tissue samples connected with the initiation of muscle fiber cracks and ruptures, reduction of sarcomeres, nuclei deformation, nuclear chromatin diminishing, and destruction of mitochondria is analyzed.

Structural changes in manufacturing industry at division level: Serbia and new EU member states

Research in this paper is oriented towards structural changes at the division level of the manufacturing industry. The goal of the research is to point at the significance of the efficient structural reforms of Serbia's manufacturing industry, more precisely to point at the size, intensity, speed and directions of the changes made in its structure. In the paper, the basic indicators of structural changes are used, namely the trend of the share of employment and the value added. The size of the changes is analyzed by the standard deviation and the dispersion of growth rates, whereas the intensity of changes is analyzed by the elasticity of the divisions' growth rates. A correlation analysis is used to determine the directions and nature of the connectedness of structural changes between divisions, whereas the direction of changes is shown by the Spearman rank correlation coefficient of their growth rates. The Structural Change Indicator is used for researching the pace and patterns of structural changes. At the division level, by applying the comparison method, differences in the directions, speed and patterns of the structural changes of the Serbian manufacturing industry are analyzed against the new EU member states for which there are comparative data (Bulgaria, Romania, Hungary, the Czech Republic, Poland, Slovenia and Slovakia). The research results indicate that growth rates were higher in those divisions in which reforms were more comprehensive, faster, more intensive and efficiently fully implemented.

Effects of NaCl and pH on the structural conformations of kidney bean vicilin

Structural changes as a result of variations in pH value and salt concentration were determined for purified vicilin, the major globular protein in kidney beans using intrinsic fluorescence and circular dichroism (CD). The vicilin consisted of two polypeptide chains of about 43 and 45kDa in size when analysed under reducing SDS–PAGE. Amino acid analysis showed that the vicilin had high contents of acidic amino acids and a low lysine/arginine ratio. Intrinsic fluorescence measurements were performed to measure exposure of tyrosine and tryptophan as a means of estimating protein conformational changes. Generally, the vicilin showed an unfolded structure at pH 3.0, 5.0, 7.0, and 9.0 as evident by the extensive red shift (>350nm) of the wavelength of maximum tryptophan fluorescence intensity. At pH 3.0 and 5.0, the fluorescence intensity (FI) was greater than values obtained at pH 7.0 and 9.0, which suggests that the microenvironment of tryptophan was less hydrophilic at acidic pH. Addition of NaCl also led to increased FI, an indication of structural changes of tryptophan in response to the hydrophilic environment. These changes in FI were due mostly to tryptophan emission because tyrosine emission (at 303nm) was suppressed. The far-UV CD spectra showed that vicilin had minimal measurable secondary structures at pH 3.0 and 5.0 when compared to pH 7.0 and 9.0. Addition of NaCl led to an increase in the tertiary structure conformation of vicilin as determined from the near-UV CD spectra.

High-precision mass measurements of 203-207Rn and 213Ra with SHIPTRAP

The masses of the nuclides 203-207Rn and 213Ra were measured directly for the first time with the Penning-trap mass spectrometer SHIPTRAP at GSI Darmstadt. The results confirm the previously determined mass values. The mass uncertainties for 205Rn and 213Ra were significantly reduced. The results are relevant for the investigation of the nuclear shell structure between N = 82 and N = 126 . As an indicator of structural changes the two-neutron separation energies $ S_{2n}(Z,N)$ have been studied.

P 17: Analysis of the relationship between parameters of total and abdominal obesity, levels of lipoproteins and occurrence of coronary heart disease in type 2 diabetes

Atherosclerosis is the commonest and the most important cause of coronary heart disease (CHD). Among the risk factors for its occurrence the key ones are diabetes mellitus, obesity and dyslipidemia. Therefore, the aim of this study was to determine the connection between the parameters of total and abdominal obesity, level of lipoproteins and the occurrence of CHD in type 2 diabetes (T2D). The research was conducted on 85 patients, 39 diabetics and 46 nondiabetics divided into the following groups: 18 patients with T2D and previously diagnosed CHD (group 1), 21 patients with T2D but without CHD (group 2), 24 nondiabetics with previously diagnosed CHD (group 3) and 22 nondiabetics without CHD (group 4). As an indicator of total obesity we calculated the body mass index (BMI). As parameters of abdominal obesity waist circumference (WC) and waist to hip ratio (WHR) were used. Total cholesterol (ch), HDL-ch, LDL-ch and Triglycerides (Tg) levels were determined by chromatography. We used also Tg/ HDL-ch ratio as an indicator of structural changes in subfractions of cholesterol particles and an independent risk factor for CHD. We found there is no difference in BMI in group 1 vs group 2 (28.09+/−0.82 vs 28.07+/−0.92 kg/m 2 , p=NS) neither in group 3 vs group 4 (27.58+/−0.97 vs 27.16+/−0.71 kg/m 2 , p=NS). WC and WHR values were significantly higher in group 1 vs group 2 (103.06+/−1.88 vs 97.60+/−1.99 cm, 0.98+/−0.01 vs 0.91+/−0.01; p<0.05 respectively) and in group 3 vs group 4 (95.15+/−2.42 vs 90.10+/−2.55 cm, 0.89+/−0.01 vs 0.83+/−0.01, p<0.05 respectively). Comparing the diabetics and nondiabetics, we have found that WC and WHR were significantly higher in diabetics (100.25+/−1.89 vs 92.50+/−2.53; 0.95+/−0.01 vs 0.86+/−0.01; p<0.05 respectively). There was no difference in levels of total ch between groups 1 and 2 (6.59+/−0.33 vs 6.32+/−0.37 mmol/L; p=NS), but total ch levels were significantly higher in group 3 compared to group 4 (6.27+/−0.20 vs 5.70+/−0.16 mmol/L, p<0.05). LDL-ch levels and Tg levels were significantly higher in group 1 vs group 2 (LDL-ch: 4.39+/−0.32 vs 3.61+/−0.24 mmol/L, p<0.05, Tg: 3.68+/−0.59 vs 3.08+/−0.60 mmol/L, p<0.05) and in group 3 vs group 4 (LDL-ch: 4.05+/−0.2 vs 3.59+/−0.17 mmol/L, p<0.05, Tg: 2.55+/−0.35 vs 1.58+/−0.16 mmol/L, p<0.05). There were no difference in HDL-ch levels between these groups (1: 1.04+/−0.06; 2: 1.14+/−0.08; 3: 1.25+/−0.08; 4: 1.25+/−0.07; 1 vs 2 and 3 vs 4 p=NS). However, Tg/HDL ratio was significantly higher in group 1 vs group 2 (4.11+/−0.88 vs 2.87+/−0.67, p<0.01) and in group 3 vs group 4 (2.18+/−0.34 vs 1.40+/−0.19, p<0.05). Also, by method of correlation, we found that in patients with CHD BMI significantly correlate with Tg and Tg/HDL ratio (r=0.338, p<0.05; r=0.388, p<0.05 respectively), while WC and WHR significantly correlate with Tg (r=0.387, p<0.05; r=0.410, p<0.01 respectively), Tg/HDL ratio (r=0.505, p<0.01; r=0.497, p<o.01 respectively) and HDL-ch (r=-0.450, p<0.01; r=-0.494, p<0.01 respectively). Our results have demonstrated that abdominal obesity disrupts cholesterol reverse path, leading to changes in the structure and composition of the HDL subfraction of cholesterol, which is one of the possible pathogenetic mechanisms of atherogenic effects of abdominal obesity. Also, this suggest that parameters of abdominal obesity could be an useful screening test for detecting people with dyslipidemia and high risk of developing CHD, especially diabetics.

Analysis of homodimeric avian and human galectins by two methods based on fluorescence spectroscopy: Different structural alterations upon oxidation and ligand binding

Spectroscopic monitoring is applied to detect structural alterations for homodimeric adhesion/growth-regulatory galectins. Mammalian galectin-1 and the avian ortholog CG-1B, due to their distinct patterns of cysteine positioning, can undergo oxidation. When monitoring tryptophan fluorescence anisotropy comparatively, an indicator of structural changes affecting rotational diffusion, segmental motion and/or fluorescence life time, reductions are seen in both cases upon oxidation. The decrease was especially marked for the human protein, more than 2-fold compared to the avian lectin. Using this approach to analyze binding of lactose, equilibrium and kinetic binding constants of both proteins were similar. This result is corroborated by fluorescence correlation spectroscopy with labeled proteins. Of note, the diffusion constant of CG-1B increased by 5.6% in the presence of lactose, as has been seen for the human protein. When processing the other two homodimeric avian galectins (CG-1A, CG-2) accordingly it was revealed that sequence homology does not translate into identical behavior. The diffusion constant of CG-1A was not affected, a slight decrease (-3.8%) was observed for CG-2. Obviously, alterations induced by oxidation and responses to ligand binding are different between these closely related proteins. Methodologically, the two spectroscopic techniques are proven to be sensitive and robust sensors for detecting intergalectin differences.

K-35, a fluorescent probe for albumin study: Optical properties

Fluorescent probe N-(carboxyphenyl)imide of 4-(dimethylamino)naphthalic acid, K-35, is used as an indicator of structural changes of human serum albumin molecules in pathology. The probe occupies albumin binding pockets where the probe environment is of very high polarity; probably, the pocket(s) contains protein polar groups and water molecules. At the same time rather small Stokes shift of K-35 fluorescence spectrum shows that the polar group motion is of one-two order of value lower than mobility of polar molecules in polar fluids. K-35 fluorescence decay in HSA can be described as a sum of three exponentials with time constants close to tau1=9 ns; tau2=3.6 ns and tau3=1.0 ns. A difference between excitation maxima of these three decay components shows that environment of these three species of K-35 molecules has been different before excitation. Different r values are probably a consequence of non-identical structure of several binding sites, or a binding site(s) can have a variable conformation.

The role of habitat complexity on spider communities in native alpine grasslands of New Zealand

Abstract. 1. Physical structure and species composition of vegetation determine spider diversity through habitat availability. Here, we assess, for the first time, the role of plant structure on spider communities in New Zealand native alpine tussock grasslands. We investigate the specific associations between spider assemblages and plant communities and test the hypothesis that spider diversity increases with plant diversity and tussock cover.2. Spiders were sampled using density‐ and abundance‐activity‐dependent methods. Data on physical characteristics and species composition of plants revealed gradients in vegetation, driven by distinct intra‐ecosystem plant communities. Effects of vegetation on spider diversity and composition were assessed through linear mixed‐effects models. Redundancy analysis was used to determine and visualise the spider species–level response to gradients in plant compositions.3. There was a positive relationship between plant diversity and spider diversity, while the effects of tussock cover varied with spider taxa. Overall, physical structure and species composition of vegetation had effects on the abundance of a similar number of spider species and families.4. Gradients in vegetation were matched to gradients in spider communities, whose diversity and composition varied according to their habitat preference. The family Orsolobidae was associated with wetland vegetation, and Linyphiidae with shrubs. The abundance of certain spider families and species, such as Lycosidae and Anoteropsis hilaris, was consistently affected by vegetation.5. Environmental factors, such as soil moisture, may affect plant species composition and physical structure in tussock grasslands, which in turn determine spider assemblages. Lycosidae were identified as potential indicators of structural changes in tussock grassland plants and could be valuable for ecological monitoring in conservation management.

Impact of Thermal Treatment on PECVD Al2O3 Passivation Layers

We present a detailed study about the influence of post-deposition temperature treatment on PECVD Al2O3 passivation layers. Fourier transform infrared spectroscopy (FTIR) and quasi-steady-state photoconductance (QSSPC) were applied for characterization. We observed several indications of structural changes of the Al2O3 layer with annealing duration, temperature and layer thickness. A shift and an increase of the Si-O vibrational mode (1100- 980cm-1) in the FTIR measured with changing temperature and layer thickness is presented. Structural changes of the Al2O3 layer with annealing duration, temperature, and layer thickness, caused by changes in the oxygen concentration within the SiOx layer are observed for the different FTIR spectra. We also detected a water band at 1650-1630cm-1 and other OH components around 3200cm-1-400cm-1 depending on annealing temperature and time. For a temperature of 820°C, a dramatic change of the Al2O3 peak (650-700cm-1) is observed. This is probably due to the crystallization of the film.

Can Sectoral Re-allocation Explain the Jobless Growth? Empirical Evidence from Pakistan

The present paper discuss the nature of structural changes in employment to understand jobless growth in Pakistan for the period spanning over 1967-2008. In our work (elsewhere)1 analysing Pakistan at sectoral level to find underlying factors generating jobless growth, we found that Jobless growth in manufacturing sector was anticipated. Industrial sector has a significant importance in any economy across the glob. Recent changes in the use of capital—based foreign technology has resulted in substitution of labour with non-labour inputs such as capital. Employment shifts between industrial sectors are often witnessed as indicators of Structural change in an economy. In this paper we are more interested in the nature of structural change that took place in Pakistan economy over 1967-2008. We set to analyse four commonly used measures of sectoral reallocation proposed by Lilien (1982), Groshen and Potter (2003), Rissman (1997), and Aaronson, Rissman and Sullivan (2004). Findings of our work are suggesting that the economy of Pakistan underwent structural change during periods of recession and recovery. However, it does appear that structural changes were more pronounced at the time of 1969 recession than that of 1991 recession. A plausible explanation for this result might be significant shifts in employment from agriculture towards services sectors. We conclude, based on the evidence from our study, that sectoral reallocation is one of the major causes of jobless growth in Pakistan.

A Novel In Vivo Joint Loading System to Investigate the Effect of Daily Mechanical Load on a Healing Anterior Cruciate Ligament Reconstruction

We designed and validated a novel knee joint fixation/distraction system to study tendon-to-bone healing in an in vivo rat model of anterior cruciate ligament (ACL) reconstruction. The system uses an external fixator to apply a cyclic distraction of the knee joint while monitoring the resultant force developed across the joint, thus providing a temporal indication of structural changes during the healing process of the bone-tendon-bone reconstruction. The validation was performed using an optical kinematic tracking system to determine the local displacement of the knee. The average system compliance was determined to be 42.4 +/- 8.8 mum/N with a coefficient of variation of 20.7%. The compliance was used to obtain a best fit correction factor which brought the total root mean square error of knee joint distraction to within 179 mum (16.1%) of the applied distraction. We performed a pilot study using 15 rats that had ACL reconstructions using a flexor digitorum longus tendon autograft and found that the animals tolerated the indwelling fixator and daily anesthesia over a 10 day loading protocol. Our knee joint fixation/distraction system provides a valuable tool to study how mechanical stimuli affect in vivo bone-tendon-bone healing.

Interorganizational Network Changes Among Health Organizations in the Brazos Valley, Texas

Community health development is a process by which a community identifies factors influencing population health, assesses available resources to build the capacity to plan and take action, and implement interventions to address identified needs. At its core, community health development targets structural change and infrastructure development to facilitate more efficient and effective health service delivery systems and environmental changes to support improvements in community health. One indicator of structural change and common measure of community capacity is the relationships among the network of organizations that comprise that system. The Brazos Valley has employed a community health development approach to population health improvement in partnership with the Center for Community Health Development. Changes in interorganizational networks illustrate progress in the Brazos Valley. Contextual factors provide some insight into how the process has unfolded.

Dynamic animations of journal maps: Indicators of structural changes and interdisciplinary developments

AbstractThe dynamic analysis of structural change in the organization of the sciences requires, methodologically, the integration of multivariate and time‐series analysis. Structural change—for instance, interdisciplinary development—is often an objective of government interventions. Recent developments in multidimensional scaling (MDS) enable us to distinguish the stress originating in each time‐slice from the stress originating from the sequencing of time‐slices, and thus to locally optimize the trade‐offs between these two sources of variance in the animation. Furthermore, visualization programs like Pajek and Visone allow us to show not only the positions of the nodes, but also their relational attributes such as betweenness centrality. Betweenness centrality in the vector space can be considered as an indicator of interdisciplinarity. Using this indicator, the dynamics of the citation‐impact environments of the journals Cognitive Science, Social Networks, and Nanotechnology are animated and assessed in terms of interdisciplinarity among the disciplines involved.

X-ray structures of cobalt(III) complexes with bio-relevant pyrazolyl thiosemicarbazone: Indication of structural changes on the increasing bulkiness of the alkyl substituents on thiosemicarbazone moiety

X-ray crystallographic studies of cobalt(III) complexes of 5-methyl-3-formylpyrazole-N(4)-diethylthiosemicarbazone (HMPzNEt2), [Co(MPzNEt2)2]Br·2H2O, 5-methyl-3-formylpyrazole-N(4)-dipropylthiosemicarbazone (HMPzNPr2), [Co(MPzNPr2)2]Br·2H2O and 5-methyl-3formylpyrazole-N(4)-dibutylthiosemicarbazone (HMPzNBu2), [Co(MPzNBu2)2]Br·H2O, have been reported. In all the three complex species, X-ray crystallography has authenticated a CoN4S2 octahedral coordination with the pair of orthogonally coordinated NNS tridentate ligands in the monodeprotonated form of the ligand. The two azomethine nitrogen atoms are trans to each other, while the pyrazolyl ring nitrogens and the thiolato sulfurs are in cis positions. A gradual decrease in the dihedral angle between the coordinating ligands has been observed with increase in the bulkiness of the aliphatic side chains of the substituent on the thiosemicarbazone moieties. In all the three complexes, intraligand C–H···S contacts appear to arrest the free rotation of the side chains about the C(6)–N(5) single bond.

Study of structural phase transitions in YBa2Cu3O6+δ by x-ray photoelectron spectroscopy

We have used x-ray photoelectron spectroscopy to investigate the charge state of oxygen found in the basal structural plane of YBa2Cu3O6+γ.. We have observed a change in this state after thermal treatment, with a transition to the adjacent structural phase region. We have shown that changes in the charge state of oxygen can be used as an indicator of structural changes occurring in YBa2Cu3O6+δ.. We have found that the rate of structural relaxation yttrium barium cuprate depends on the amount of structural water it contains.

Mentalisation et psychothérapie chez le patient limite

Psychotherapy of borderline patients allows us to observe that often, the intense affects, the rage and the lack of good internal objects prevent the mentalization of object relations that are confined to acting-out. Moreover, mentalization deficiency inhibits the experience of relationships with a good object in the transference, which often jeopardizes the continuation of the treatment. It is argued that these dimensions of borderline pathology can be better worked out by closely adjusting therapeutic interventions to the patient's ability to mentalise psychological experiences, particularly with regards to positive transference. We explain our view that the capacity to mentalise in the transference a relationship with a good object is an indication of structural change.

Pressure−Volume−Temperature Dependence of Polypropylene/Organoclay Nanocomposites

The pressure−volume−temperature (PVT) dependencies of commercial polypropylene melt (PP) and its nanocomposites containing X wt % of organoclay (Cloisite-15A, or C15) and 2X wt % of a compatibilizer were determined at T = 450−530 K and P = 0.1−190 MPa. C15 was used at concentrations: X = 0, 2, and 4 wt %. Three functionalized PP's were used as compatibilizers: two maleated and one grafted with glycidyl methacrylate. Incorporation of X = 2 wt % C15 into PP resulted in reduction of specific volume by ΔV ≈ 1%, but that of free volume (hole) fraction by Δh ≈ 5%. The latter quantity was computed from the Simha−Somcynsky lattice−hole equation of state. Furthermore, at constant T and P the hole fraction was found to be linearly related to the bulk-average energetic interaction parameter and to be a sensitive indicator of structural changes. In binary (polymer + organoclay) systems Δh is linearly related to the interlayer spacing, d001. So, where statements from the previous paper are repeated or there are similarities, this is done for purposes of comparison. In three-component systems (with a compatibilizer) the proportionality has been preserved, but large changes of Δh result in relatively small changes of d001. Mechanical properties hardly correlate with either Δh or d001, as polymer/compatibilizer morphology and crystallinity complicate the behavior.

Effect of strain on NiTi surface-optical reflectivity

The mechanical interaction of living cells upon a NiTi surface was simulated with external loads. The surface structural response was studied. Optical reflectivity, which is a sensitive indicator of structural changes at the surface, was used. The behaviour of reflectivity under tension and compression within the range of strains up to 5% was analysed. The probability of reversible martensitic transformations (MT) in the surface oxide layer was demonstrated. The peculiarities of these MT in comparison with those in the bulk of the alloy were considered. Irreversible structural changes occurred in surface oxide under external stresses, despite complete strain recovery after unloading. A correlation emerged between the strains caused by external stresses and the residual augmentation of reflectivity. The probable mechanisms of irreversible structural changes initiated at the NiTi surface by external load action are discussed.

Vibrational spectroscopy of beta-eucryptite (LiAlSiO 4 ): optical phonons and phase transition(s)

The structural behavior of β-eucryptite (LiAlSiO4) has been investigated using infrared (IR) spectroscopy over a temperature range of 20 to 900 K and FT-Raman spectroscopy at room temperature. IR reflectance measurements show that β-eucryptite possesses high reflectivity in the far-IR region, as is consistent with its reported superionic conductivity along the c-axis. On heating, the Li-related IR bands near 246 and 300 cm−1 (with A2 symmetry) broadened and weakened dramatically, presumably as a result of Li+ positional disordering along the structural channels parallel to c. The disordering process appears to induce a framework distortion, as is evidenced by the broadening of some vibrations of Si(Al)–O with increasing temperature. A change in slope in the temperature dependence of the phonon frequency near 300 cm−1 and the linewidth of the 760 cm−1 band at ∼715 K indicates that Li becomes completely disordered above this temperature. In addition, the temperature dependence of the linewidth for the 760 cm–1 band exhibits an additional change in slope at 780 K, implying the existence of an intermediate state within this temperature range. The detailed structure of this intermediate phase, however, needs further study. Our IR data provide no indication of structural changes between room temperature and 20 K.