Change In Relative Mobility Research Articles

Varieties of Mobility Measures: Comparing Survey and Mobile Phone Data during the COVID-19 Pandemic.

Human mobility has become a major variable of interest during the COVID-19 pandemic and central to policy decisions all around the world. To measure individual mobility, research relies on a variety of indicators that commonly stem from two main data sources: survey self-reports and behavioral mobility data from mobile phones. However, little is known about how mobility from survey self-reports relates to popular mobility estimates using data from the Global System for Mobile Communications (GSM) and the Global Positioning System (GPS). Spanning March 2020 until April 2021, this study compares self-reported mobility from a panel survey in Austria to aggregated mobility estimates utilizing (1) GSM data and (2) Google's GPS-based Community Mobility Reports. Our analyses show that correlations in mobility changes over time are high, both in general and when comparing subgroups by age, gender, and mobility category. However, while these trends are similar, the size of relative mobility changes over time differs substantially between different mobility estimates. Overall, while our findings suggest that these mobility estimates manage to capture similar latent variables, especially when focusing on changes in mobility over time, researchers should be aware of the specific form of mobility different data sources capture.

Heterogeneity in Response to India's Initial COVID‐19 Nationwide‐Lockdown: A Quasi‐Experimental Study Using Aggregate Mobility Data

Research ObjectiveIndia's March 2020 nationwide lockdown garnered early support from the World Health Organization, but has also been the subject of criticism due to strict enforcement and the inaccessibility of basic supplies for those under lockdown. Given the scale of the policy and relevant concerns, there is an urgent need to better understand the impact of this policy on its intended outcome: slowing covid case growth.Study DesignWe assessed state‐level variation in response to the nation‐wide lockdown. Using a public dataset of differentially privatized aggregate mobility data, we assessed the combined impact of the Janta Curfew and lockdown using a Single Interrupted Time Series (SITS) design. Our primary outcomes were change in relative mobility and change in state‐level COVID‐19 case growth. We first looked at variation in mobility between states and then used the results from state‐level SITS to assess the relationship with COVID‐19 case growth. To do so, we used a model with rate of increase in COVID‐19 cases over time as our dependent variable and change in aggregate mobility as our predictor, controlling for population demographics, such as: size, urbanicity and poverty as well as known COVID‐19 cases (cumulative as of March 25th). For COVID‐19, we used “Covid19India” which aggregated statistics from the Ministry of Health and Family Welfare (MoHFW), each state or union territory and the Indian Council of Medical Research (ICMR).Population StudiedOur analytic sample included 10,512 state‐day observations, representing 1.21 billion individuals across 36 states and union territories in India.Principal FindingsWe observed an immediate and pronounced decrease in mobility following the policy's implementation. Overall the lockdown was associated with an 86% decrease in mobility as compared to a location‐specific pre‐lockdown baseline. However, these effects were not homogeneous by mobility type, nor were they homogeneously sustained in the post‐policy period. Visits to grocery stores and pharmacies (slope = 0.62% increase in visits per day) and transit stations (slope = 0.24%) began to recover relatively quickly whereas visits to retail and recreation (slope = −0.41%), and parks (slope − 0.47%) continued to decline during the post period. We observed significant state‐level variation in mobility responses (71% to 95% decrease in visits to retail and recreation sites). States with the largest decreases in aggregate mobility to retail and recreational sites had a relatively slow (7.2%) rate of increase in COVID‐19 case growth in contrast to states with the lowest decreases in mobility, who saw a 53% rate increase in COVID‐19 cases (p = 0.03) over the same time period.ConclusionsStates that were most effective in responding to the lockdown policy, as measured by decreased mobility, were also most effective in slowing covid case growth (controlling for state wealth, size, and urbanicity).Implications for Policy or PracticeWhile our findings suggest India's nationwide lockdown may have been effective in achieving its primary goal, we require a better understanding of what drives sub‐national variation in policy adherence over time as well as careful tracking of unintended economic and wellbeing costs.

On the way to becoming a society of downward mobility? Intergenerational occupational mobility in seven West German birth cohorts (1944–1978)

Many studies on social mobility use operationalizations of social positions that do not take occupational upgrading into account. In order to estimate social mobility patterns net of occupational upgrading, I propose an operationalization involving administrative data to measure social positions by applying a percentile approach. Based on this measurement I calculate absolute and relative intergenerational mobility patterns.Using this operationalization, I aim to answer the question of how far intergenerational mobility patterns have changed over time in West Germany. Therefore, I analyze the occupational data of 7,416 38- to 42-year-olds born between 1944 and 1978 belonging to the sixth starting cohort of the National Educational Panel Study (NEPS). Compared to previous studies, I observe significantly higher rates of downward mobility. However, I do not find any cohort trends in absolute mobility rates and do not detect any changes in social fluidity patterns. I therefore conclude that there are no cohort trends in absolute or relative intergenerational mobility in West Germany, implying that it is not on its way to becoming a society of downward mobility. In contrast to previous studies, my results indicate high social fluidity and no changes in relative mobility over time. Hence, the picture of a rigid German social structure should be reconsidered.

Quantifying Sediment Transport Dynamics on Alluvial Fans From Spatial and Temporal Changes in Grain Size, Death Valley, California

How information about sediment transport processes is transmitted to the sedimentary record remains a complex problem for the interpretation of fluvial stratigraphy. Alluvial fan deposits represent the condensed archive of sediment transport, which is at least partly controlled by tectonics and climate. For three coupled catchment‐fan systems in northern Death Valley, California, we measure grain size across 12 well‐preserved Holocene and late‐Pleistocene surfaces, mapped in detail from field observations and remote sensing. Our results show that fan surfaces correlated to the late Pleistocene are, on average, 30–50% coarser than active or Holocene fan surfaces. We adopt a self‐similar form of grain size distribution based on the observed stability of the ratio between mean grain size and standard deviation downstream. Using statistical analysis, we show that fan surface grain size distributions are self‐similar. We derive a relative mobility function using our self‐similar grain size distributions, which describes the relative probability of a given grain size being transported. We show that the largest mobile grain sizes are between 20 and 35 mm, a value that varies over time and is clearly lower in the Holocene than in the Pleistocene; a change we suggest is due to a drier climate in the Holocene. These results support recent findings that alluvial fan sedimentology can record past environmental change and that these landscapes are potentially sensitive to climatic change over a glacial‐interglacial cycle. We demonstrate that the self‐similarity methodology offers a means to explore changes in relative mobility of grain sizes from preserved fluvial deposits.

Ultrasound imaging of the lower urinary tract after successful tension‐free vaginal tape (TVT) procedure

To evaluate changes in the mobility of the whole urethra, in the proximal urethra (funneling) and in the thickness of the urinary bladder wall, after a successful tension-free vaginal tape (TVT) procedure. This prospective longitudinal study included 52 women with urodynamically confirmed stress urinary incontinence who had undergone a successful TVT procedure. Ultrasound examination was performed before the TVT procedure and at a median of 3 (range, 3-6) months after surgery. For all women, the changes to the urethra and urinary bladder induced by surgery were examined. For three mobility groups (low, intermediate and high urethral mobility before surgery) we compared the changes induced by the operation and the typical position and mobility of the tape. The position of the urethra at rest was not influenced by surgery. The operation significantly decreased the mobility of all parts of the urethra during Valsalva. The absolute changes of the vector of the urethral movement differed according to the mobility group (average decrease, 6 mm; decrease for women with low, intermediate and high mobility, respectively, 2-3 mm, 4-6 mm and 9 mm). The change in relative mobility was the same in all groups. The operation decreased funneling (width and depth) during maximal Valsalva. After surgery there was an increase in the thickness of the bladder wall (by 0.64 and 0.73 mm, respectively, at the anterior part and trigone). A successful TVT procedure did not influence the position of the urethra at rest but significantly decreased the mobility of the urethra during Valsalva and also decreased funneling at maximal Valsalva.

Change in relative mobility of M protein following neuraminidase treatment in patients with multiple myeloma and monoclonal gammopathy of undetermined significance.

The aim of this study was to clarify the relationship between the relative mobility of M protein in various disease states using cellulose acetate membrane electrophoresis. To examine the carbohydrate chain of the M protein, sera from patients with multiple myeloma (MM), various cancers, and benign disease were treated with neuraminidase. The relative mobility in benign disease and MM patient sera following neuraminidase treatment varied among individuals, while that of IgG M protein in sera from cancer patients was from 0.2 to 0.3. Thus, the relative mobility in cancer patients was narrower than in those with MM or benign disease.However, after neuraminidase treatment, there was no significant difference between relative mobility in cancer patient's sera and those in other disease patients.

Investigation of drift gas selectivity in high resolution ion mobility spectrometry with mass spectrometry detection

Recent studies in electrospray ionization (ESI)/ion mobility spectrometry (IMS) have focussed on employing different drift gases to alter separation efficiency for some molecules. This study investigates four structurally similar classes of molecules (cocaine and metabolites, amphetamines, benzodiazepines, and small peptides) to determine the effect of structure on relative mobility changes in four drift gases (helium, nitrogen, argon, carbon dioxide). Collision cross sections were plotted against drift gas polarizability and a linear relationship was found for the nineteen compounds evaluated in the study. Based on the reduced mobility database, all nineteen compounds could be separated in one of the four drift gases, however, the drift gas that provided optimal separation was specific for the two compounds.

Quercetin Abrogates Taxol-Mediated Signaling by Inhibiting Multiple Kinases

Cell cycle block in G2/M initiates apoptosis, but the mechanism of this signaling cascade are largely unknown. The microtubule-perturbing agent Taxol has multiple effects on this signaling pathway and is a potent inducer of apoptosis. The specific pathways activated by low, clinically relevant concentrations of the drug are still largely unknown and are dependent on cell type and drug concentration. In this work, we have investigated why HeLa cells respond to Taxol by undergoing complete apoptosis, whereas MCF-7 cells remain in an intermediate phase with reduced death. Three phases were distinguished in these apoptotic pathways. The initial phase characterized by cellular detachment is followed by a second phase which includes the onset of apoptotic morphology, and p38 and Bcl-2 phosphorylation. These two phases are common to both cell lines. HeLa cells then proceed to the third and final execution phase, which culminates in death, whereas MCF-7 cells do not progress. Interestingly, the isoflavonoid Quercetin, a known general kinase inhibitor and an antioxidant, was able to prevent the onset of Taxol-induced cellular detachment and to protect from cell death. Moreover, it blocked Taxol-induced phosphorylation of p38 and Bcl-2, and prevented a Taxol-induced change in relative mobility of the apoptosis signal-regulating kinase 1 (Ask1). Our data elucidate the signaling pathways activated by Taxol at low clinically relevant concentrations.

Dielectric friction in capillary electrophoresis: mobility of organic anions in mixed methanol-water media.

The mobilities of a series of organic carboxylates and sulfonates, ranging in charge from -1 to -4, were investigated by capillary electrophoresis using buffers containing 0 to 75% (v/v) methanol. Effective mobilities were measured at a series of ionic strengths, and were extrapolated to zero ionic strength using Pitts' equation to yield absolute mobilities. Generally, higher-charged ions were more strongly influenced by ionic strength, as predicted by the Pitts' equation. Some differences in the ionic strength effects for anions of like charge were observed and were consistent with the relaxation effect. The absolute mobilities of anions were altered by the addition of methanol to the buffer. Analytes with higher charge-to-size ratios were slowed to a greater extent than were ions with lower charge-to-size. As a result, dramatic changes in relative mobility were observed, such as a reversal in migration order between anions of -1 and -4 charge at 75% methanol and 20 mM ionic strength. The mobility changes caused by the addition of methanol are attributed to dielectric friction. Mobilities in the methanol-water solutions were found to depend on analyte charge-to-size and solvent dielectric relaxation time (tau) and were inversely dependent upon solvent dielectric constant (epsilon), as predicted by the Hubbard-Onsager mobility model.

The identification of O-glycosylated precursors of insulin-like growth factor II.

A procedure that combined ion exchange, gel permeation, and insulin-like growth factor-binding protein 3 (IGF-BP-3) affinity chromatography with chromatofocusing and reversed-phase high pressure liquid chromatography was used to isolate high molecular weight precursors of human insulin-like growth factor II (IGF-II) from acetic acid extracts of Cohn fraction IV1. Two precursors had isoelectric points (pI) of 5.1 and 5.4 and apparent Mr values of 15,000 and 11,500, respectively. An apparent Mr = 16,000 RLPG/Ser29 variant of IGF-II was also identified in the acetic acid extracts. Amino-terminal amino acid sequencing of the major E domain-containing peptide that had been isolated from apparent Mr = 15,000 IGF-II (pI 5.1), following its digestion with the endoprotease Lys-C, indicated the carboxyl terminus of this precursor was near or at Lys88. During the sequencing of this peptide, a sharply reduced yield of derivatized amino acid occurred at cycle 10, indicating that Thr75 had been posttranslationally modified, possibly by O-glycosylation. To evaluate this possibility, the 125I-labeled high molecular weight IGF-IIs and their endoprotease-generated peptides were treated with glycosidases, and their effects were determined from the change in relative mobilities of the polypeptide and peptides during sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Neuraminidase treatment of apparent Mr = 15,000 and 11,500 IGF-II reduced their Mr values to a common value of 10,500. When the desialylated precursors of IGF-II were treated with O-glycosidase, but not when treated with N-glycosidase, the Mr values were reduced further to about 10,000. This was the Mr value that would be predicted for an unglycosylated form of precursor IGF-II that had a carboxyl-terminal end at or near Lys88. When the Ser66-Lys88 endoprotease-generated E domain peptides from pI5.1 and 5.4 high Mr IGF-II were treated with the glycosidases, they had relative mobility changes during sodium dodecyl sulfate-polyacrylamide gel electrophoresis that were similar to those of the intact precursors. Finally, the association of O-linked oligosaccharide with the E domain peptide of IGF-II was confirmed by demonstrating the specificity of binding of the Ser66-Lys88 asialoglycopeptide to jackfruit lectin.

Changes in relative mobility of pancreatic amylase variants in isoelectric focusing

Using isoelectric focusing with one ampholytic solution, double- and single-banded amylase phenotypes were found in a sample of rhesus monkeys,Macaca mulatta. When applying different ampholytic solutions, these variants were shown to change their position relative to each other. Single-banded phenotypes showed either a position corresponding to one of the bands of the double-banded phenotype or to an intermediate one. Family studies, however, suggested that the differences between the observed patterns were not caused by genetic differences. This discloses a problem with respect to the interpretation of electrophoretic data, i.e. bands with different positions produced by isoelectric focusing may not necessarily represent genetic differences.

Electrophoretic behavior of d(GGAAAAAAGG)n, d(CCAAAAAACC)n, and (CCAAAAAAGG)n, and implications for a DNA bending model

Double stranded multimers (C2A6C2)n, (C2A6G2)n and (G2A6G2)n were prepared from chemically synthesized oligonucleotides to study the influence of sequences flanking the An tract on the curvature of DNA. All these duplexes, including polypurine.polypyrimidine one, exhibit strong retardation in polyacrylamide gel which is indicative of pronounced DNA curvature. It has been proposed previously that among the bends at the boundary with the oligo(A) tract two types should be distinguished: 5'-bends and 3'-bends (Koo et al., 1986) This distinction was deduced from different relative mobilities of two specially designed sequences having phased 5'-bends and 3'-bends, respectively. Our data indicate that the substitutions of nucleotides at both 5' and 3' boundaries of A6 tract result in comparable changes in relative mobility. Therefore, for B-B' bends it is important to take into account not only whether they are at the 5' or 3' end of an oligo(dA) tract, but also the particular sequences at the boundaries of this tract.

Evaluation of substituted polycarbonates and a blend with polystyrene as gas separation membranes

The balance between the rate and the selectivity of transport of various gas pairs in a series of polycarbonates has been examined. Replacement of the four available hydrogens on the aromatic rings of the bisphenol-A unit with CH 3, Cl, or Br groups gives materials with a better balance of these two characteristics than the unsubstituted polycarbonate (PC). For example, using CH 3 substitution increases the permeability to O 2 by nearly a factor of four with no loss in O 2/N 2 selectivity compared with PC, while using Br substitution increases O 2/N 2 selectivity by 50% without any loss in O 2 permeability compared with PC. While these substitutions affect the permeability through both its mobility and solubility components, the remarkable selectivity effects are caused primarily by changes in relative mobility since the changes in solubility characteristics are nearly the same for all gases. These substitutions alter chain motions, cohesion, and packing as discussed. The tetramethylbisphenol-A polycarbonate forms miscible blends with polystyrene. These blends show absolute permeability coefficients which are lower than additivity while the selectivity of transport is greater. These effects are a result of the interactions between the two polymers.

Electrophoretic and 31P nuclear magnetic resonance evidence for alterations in conformation and net charge on phosphorylation and “aging” of α-chymotrypsin

Native α-chymotrypsin and its phosphoenzyme and “aged” phosphoenzyme derivatives are conveniently differentiated by polyacrylamide gradient gel electrophoresis in a pH 4.5 buffer. The changes in relative mobilities most likely reflect alterations in conformation induced by phosphorylation and, for the aged product, also the formation of the negatively charged substituent. Similar electrophoretic separations are achieved for the corresponding derivatives of γ-chymotrypsin and α-chymotrypsinogen A, but not for those of trypsin. Aged α-chymotrypsins give rise to two 31P resonances, also suggesting conformational isomerization of the enzyme, and the chemical shifts exhibit a small, reversible, pH dependence. A third phosphoenzyme arises on longer term incubations at pH 7.6. Under the conditions examined, 31P n.m.r. spectroscopy does not allow differentiation of the aged phosphoenzymes, intermediates in their formation, or the phosphorylated but non-aged analogs.

Labeling of a glucose binding protein in the rabbit intestinal brush border membrane.

Using a double labeling method based on the method of Thomas (Thomas, L. 1973). Isolation of N-ethylmaleimide-labeled phloridzin-sensitive D-glucose binding protein of brush border membrane from rat kidney cortex. Biochim. Biophys. Acta, 291, 454--464), with radioactive N-ethylmaleimide ([3H]NEM and [14C]NEM) in the presence and absence of D-glucose, a protein band which is periodic acid--Schiff staining insensitive and which has a relative mobility (Rm) of 0.55 (corresponding to a molecular weight of 51 000 daltons) as determined by sodium dodecyl sulfate (SDS) electrophoresis was labeled preferentially. When radioactive p-hydroxymercuriphenylsulfonate ([203Hg]PCMBS) is used in the presence and absence of D-glucose, as described by Smith et al. (Smith, M. W., Ferguson, D. R., and Burton, K. A. 1975. Glucose- and phloridzin-protected thiol groups in pig intestinal brush border membranes. Biochem. J. 147, 617--619.), a protein band which has a relative mobility of 0.62 and a corresponding molecular weight of 42 000 daltons was labeled. Control experiments have shown that increasing concentrations of nonradioactive NEM (0.1--5.0 mM) do not substantially modify the electrophoretic pattern of SDS-solubilized brush border membrane. Nonradioactive PCMBS (0.1--10 mM), on the other hand, modifies the electrophoretic pattern and especially causes a change in relative mobility of the 0.55 protein band which migrates after 1 mM PCMBS treatment with a Rm of 0.62. The effect of 1 mM PCMBS can be reversed by adding L-cysteine or dithiothreitol. Actin extracted from rabbit muscle migrates with the same Rm as the 0.55 protein band in our electrophoretic conditions.

Molecular organization in bacterial cell membranes III. Components of a “soluble” fraction obtained by n-butanol extraction of Streptomyces albus membranes

We have isolated a “soluble” fraction of Streptomyces albus G membranes or membranes previously solubilised by sodium dodecylsulphate, using n-butanol extraction. Polyacrylamide gel electrophoresis in sodium dodecylsulphate of the whole membrane showed a complex protein pattern (about 20–25 bands) with two predominant groups. The “soluble” fraction represented about 25% of the membrane protein and contained part of the major polypeptides. The yield of protein in “soluble” form decreased when membranes were suspended in water and di not significantly change if membranes were reduced with sodium dithionite and then treated with iodoacetamide. A change in relative mobility of some of these polypeptides seemed to occur with membrane delipidation. The proteins of the fraction appear to be glycoproteins as indicated by their simultaneous staining for protein and carbohydrate and the parallel sensitivity to trypsin of both stains. The apparent molecular weights by sodium dodecylsulphate gel electrophoresis of the proteins (glycoproteins) were: 63 000, 40 000 and 17 000. Similar protein patterns were obtained by extraction of the membranes with EDTA and non-ionic detergents. Lipid and nucleotide material were also found in the “soluble” fraction. The “soluble” fraction showed by gel filtration on Sephadex G-200 the existence of different states of aggregation. These states of aggregation revealed the same electrophoretic pattern of proteins, which seemingly corresponded to that of the original fraction (i.e. three protein groups with relative mobilities 0.65, 0.80 and 1.0). Treatment of the samples under different conditions with 1% dodecylsulphate (supplemented or not with 0.5% β-mercaptoethanol) failed to completely dissociate the fraction as shown by Sephadex filtration.

Microheterogeneity of N-acetyl- -D-hexosaminidase of bull epididymis.

SummaryMost (90%) of the total activity of N-acetyl-β-D-hexosaminidase (EC 3.2.1.30) of bull epididymis homogenate was found in the soluble fraction. Electrophoresis of the soluble fraction on polyacrylamide gel (5.3%) at pH 9.5 separated the enzyme into as many as 12 enzymatically active bands. The bands were successfully stained on the gel using naphthol AS-BI N-acetyl-β-D-glucosaminide as substrate; freed naphthol being coupled with fast garnet GBC. Under similar conditions, human aortic N-acetyl-β-D-hexosaminidase was separated into two bands, namely the A and B forms.In both preparations, 1 mMN-acetyl-glucosaminolactone completely inhibited staining.Incubation of bull epididymal preparation with neuraminidase resulted in the disappearance of some of the fast-moving bands and the concomitant deeper staining of the slowmoving bands. Some changes in relative mobility were also observed.

Visual perception of horizontal movement.

When two lights were presented in a dark room and one light made to move while the other was stationary, it was found that: One light was perceived as more mobile than the other when it was smaller or fixated. One light was increasingly more mobile when it was smaller and the speed was decreased, or when it was smaller and the difference in size increased, or when it was fixated and the speed decreased, or when it was both a fixated light and a small light. There was no change in relative mobility of one light when it was fixated and there was an increase or decrease of difference in size, or when it was fixated and fixation was varied to the right or to the left, or when the light was a right light or a left light. (PsycINFO Database Record (c) 2012 APA, all rights reserved)