Log-log Analysis Research Articles

Comparative Reproductive Allometry of Syntopic Black-Knobbed Sawbacks (Graptemys nigrinoda) and Alabama Map Turtles (Graptemys pulchra) in the Alabama River, with Comparison to Three Congeners

In many freshwater turtle species, increasing adult female body size is accompanied by increases in both clutch size and egg size. Because clutch size and egg size represent competing sinks for the increasing abdominal space that can be devoted to reproductive potential as a female grows larger, both are hypoallometrically related to body size, i.e., each increases at less than the rate at which body size is increasing. I studied the reproductive allometry of 2 species of the map turtle and sawback genus (Emydidae: Graptemys) in syntopy in the Alabama River. Relative to congeners, Graptemys nigrinoda is a small-bodied species and Graptemys pulchra is a large-bodied species. In the study populations, adult female G. pulchra were on average 23% larger in plastron length and 125% larger in body mass and there was no overlap in size. Both species had positive but hypoallometric relationships of both clutch size and egg size with body size, a pattern reported for 3 congeners previously, thus further demonstrating the competing sinks of increases in both variables and refuting the optimal egg size hypothesis. For interspecific comparisons using analysis of covariance, there was no significant effect of species on clutch size after accounting for the effect of plastron length. The effect of species on egg width and width of the pelvic aperture was significant, with G. pulchra having relatively wider eggs and pelvic apertures, perhaps related to the more domed carapace and larger body sizes of their hatchlings. Compared with 3 congeners, the 2 Alabama River species had relatively small clutches of relatively large eggs. Latitudinal effects on reproductive output may be important in Graptemys, with more-northerly populations tending toward larger clutches of smaller eggs. There is a need to analyze more data from more populations with log-log analyses of reproductive allometry to confirm the trend. There is also a need to consider shape allometry in future analyses; in particular, the hypoallometry of both shell height and shell width relative to shell length.

Why not see a doctor when ill? Evidence from the Chinese elderly

BackgroundElder people aged ≥45 years often have more healthcare needs than the younger. But the Chinese elderly are less likely to see a doctor when ill. In this article, this phenomenon is abbreviated as “not see a doctor”. This study aimed to describe the reason distribution of“not see a doctor” among the Chinese elderly. Specifically,we examined the reasons why“not see a doctor” happened to the Chinese elderly with different characteristics.MethodsIn order to explore the associations between various predisposing, enabling and need factors and “not see a doctor” in China, this cross-sectional study used the data from the 2015 wave 4 of the China Health and Retirement Longitudinal Study (CHARLS). Using multivariate analyses, associations between “not see a doctor” and factors were accessed. Models were estimated using a binary model with negative log-log link function (cases versus controls) and multinomial logit analysis (reasons for “not see a doctor”).ResultsAdjusted by individual weight, the analysis included 16,277 people aged ≥45 years, of whom 11% reported “not see a doctor”. Overall, those with older age, other marital status (except married) and poorer health status were more likely to report “not see a doctor”. No significant associations were found between income and “not see a doctor”. The majority of cases report “no need” as the reason for their “not see a doctor”. Except reason “no need”, factor associated with the healthcare system—cost—accounted for the most case of “not see a doctor”. Those without health insurance are more likely not to see a doctor due to affordability issues.ConclusionsThis quantitative study suggests that “not see a doctor” is more likely to happen due to age and marital status issues, especially affordability issues. For China, it is important to enforce the policy of reducing of healthcare fees and increasing health insurance coverage.

Solubility and Complexation of the Bismuthate Ion in Nitric Acid Systems.

The dissolution rate and solubility of NaBiO3 have been investigated in nitric acid systems ranging from 4 to 6 M HNO3 and were found to be 58-76 μg/cm2·d and 490-830 mM, respectively. The presence of 50 mM U(VI) drastically increased the solubility to 540-1200 mM, while rates of dissolution were relatively unchanged. The solubility of NaBiO3 increased with an increase in U(VI) concentrations at 4 M HNO3, with log-log analysis indicating a one-to-one complex between Bi and U and infrared spectroscopic evidence monitoring uranyl stretching, suggesting complex formation. Absorbance spectra were obtained experimentally and computationally with an absorbance band in the range of 450-600 nm that has been attributed to Bi(V). The ingrowth and decay of Bi(V) in solution was also studied as a function of mass of solid NaBiO3 present, acidity, and temperature. The activation energies of dissolution and decomposition were calculated to be 39 ± 4 and 61 ± 6 kJ/mol, respectively. These results indicate that dissolution of NaBiO3 into the respective Na+ and BiO3-occurs prior to undergoing reduction, a process which conventionally has been believed to occur in the reverse order.

Expanded Kinetic Control for Persistent Micelle Templates with Solvent Selection

The precision control of nanoscale materials remains a challenge for the study of nanostructure-performance relationships. Persistent micelle templates (PMT) are a kinetic-controlled self-assembly approach that decouples pore and wall control. Here, block copolymer surfactants form persistent micelles that maintain constant template size as material precursors are added, despite the shifting equilibrium dimensions. Earlier PMT demonstrations were based upon solvent mixtures where kinetic rates were adjusted with the amount of water cosolvent. This approach is however limited because ever-higher water contents can lead to secondary porosity within the material walls. Herein, we report an improved method to regulate the PMT kinetics via the majority solvent. This enables a new avenue for the expansion of the PMT window to realize templated materials with a greater extent of tunability. In addition, we report a new small-angle X-ray scattering (SAXS)-based log-log analysis method to independently test the micelle-templated series for consistency with the expected lattice expansion with an increasing material:template ratio. The PMT window identified by the log-log analysis of the SAXS data agreed well with independent scanning electron microscopy measurements. The combination of improved micelle control with solvent selection along with SAXS validation will accelerate the development of a myriad of nanomaterial applications.

Comparative study of the failure rates among 3 implantable defibrillator leads

After the introduction of the Biotronik Linox S/SD high-voltage lead, several cases of early failure have been observed. The purpose of this article was to assess the performance of the Linox S/SD lead in comparison to 2 other contemporary leads. We used the prospective Erasmus MC ICD registry to identify all implanted Linox S/SD (n = 408), Durata (St. Jude Medical, model 7122) (n = 340), and Endotak Reliance (Boston Scientific, models 0155, 0138, and 0158) (n = 343) leads. Lead failure was defined by low- or high-voltage impedance, failure to capture, sense or defibrillate, or the presence of nonphysiological signals not due to external interference. During a median follow-up of 5.1 years, 24 Linox (5.9%), 5 Endotak (1.5%), and 5 Durata (1.5%) leads failed. At 5-year follow-up, the cumulative failure rate of Linox leads (6.4%) was higher than that of Endotak (0.4%; P < .0001) and Durata (2.0%; P = .003) leads. The incidence rate was higher in Linox leads (1.3 per 100 patient-years) than in Endotak and Durata leads (0.2 and 0.3 per 100 patient-years, respectively; P < .001). A log-log analysis of the cumulative hazard for Linox leads functioning at 3-year follow-up revealed a stable failure rate of 3% per year. The majority of failures consisted of noise (62.5%) and abnormal impedance (33.3%). This study demonstrates a higher failure rate of Linox S/SD high-voltage leads compared to contemporary leads. Although the mechanism of lead failure is unclear, the majority presents with abnormal electrical parameters. Comprehensive monitoring of Linox S/SD high-voltage leads includes remote monitoring to facilitate early detection of lead failure.

Impact of Depressive Symptoms on Conversion from Mild Cognitive Impairment Subtypes to Alzheimer's Disease: A Community-Based Longitudinal Study.

While longitudinal studies have investigated the relationships between mild cognitive impairment (MCI) subtypes and dementia subtypes, the results have been contradictory. In addition, some research shows that depression accompanied by MCI might increase the risk of Alzheimer's disease (AD). The aim of this study is to longitudinally investigate the relationships between MCI subtypes and dementia subtypes, with special attention to the effect of comorbid depressive symptoms in a Japanese rural community. Non-demented participants (n = 802) completed a baseline and follow-up study. Outcomes were conversion to dementia especially AD, MCI, or no conversion. A complementary log-log analysis was conducted to investigate the risk of dementia and AD in amnestic MCI (aMCI) compared to nonamnestic MCI (naMCI) groups. The impact of depressive symptoms on the transition from MCI to AD and from cognitively normal to MCI or AD was also analyzed. The risk of developing dementia, in particular AD, for the aMCI group was significantly higher than that for the naMCI group. In the aMCI group, the presence of depressive symptoms increased the risk of developing AD, but depressive symptoms in the naMCI group did not. In the cognitively normal group, the presence of depressive symptoms increased the risk of aMCI but not naMCI or AD. MCI subtyping could be useful in finding a prodrome for dementia and in particular for AD. The differing impacts of depressive symptoms on the development of AD suggest that the relationship between depressive symptoms and cognitive impairment could differ in aMCI and naMCI patients.

Synthesis and Dichromate Extraction Study of Calix[4]arene Derivative

The present article demonstrates synthesis of 25,27-bis-N-(N,N-diethyl-2-aminoethyl-amidomethoxy)-26,28-dihydroxycalix[4]arene (4), its characterization and extraction ability toward the oxoanions such as HCr2O−7/Cr2O2 −7. The extraction efficiency was evaluated by using Pederson extraction method and data was analyzed through log-log plot analysis. The extraction was performed at varying pHs, i.e., pH 2–7. The analysis of results reveals that ligand 4 is a good extractant for dichromate at pH 3. The stoichiometric calculations obtained from Job's plot and log-log plot analyses reveals that it forms ligand:anion complex in 1:2 ratio.

Dichromate Extraction by Calix[4]arene Appended Amberlite XAD-4 Resin

In the present article a comparative extraction efficiency of dichromate by a calix[4]arene derivative (d) and a newly synthesized calix[4]arene appended Amberlite XAD-4 resin (5) are reported. The liquid and solid phase extraction methods have been applied to ascertain the extraction efficiency of both the calix[4]arene derivative and the resin. Different parameters have been optimized such as pH, dosage, concentration, and temperature. Analysis of experimental data has been carried out by log-log plot analyses and the determination of characteristic parameters of each isotherm model such as Freundlich, Langmuir, and Dubinin-Radushkevich (D-R). The kinetic adsorption experiments show that the adsorption process follows pseudo second order kinetics. The adsorption mechanism has been investigated by Reichenberg (R-B) and Morris-Webster equations. From the thermodynamic parameters it is concluded that the adsorption process is endothermic and spontaneous in nature at higher temperature. The results show that the resin-5 has good capability to efficiently remove dichromate from aqueous media.

Mechanisms, predictors, and trends of electrical failure of Riata leads

Riata and Riata ST implantable cardioverter-defibrillator leads have been shown to be prone to structural and electrical failure. To determine predictors, mechanisms, and temporal patterns of Riata/ST lead electrical failure. All 314 patients who underwent Riata/ST lead implantation at our institution with greater than or equal to 90 days of follow-up were studied. The Kaplan-Meier analysis of lead survival was performed. Results from the returned product analysis of explanted leads with electrical lead failure were recorded. During a median follow-up of 4.1 years, the Riata lead electrical failure rate was 6.6%. The rate of externalized conductors among failed leads was 57%. The engineering analysis of 10 explanted leads revealed 5 (50%) leads with electrical failure owing to breach of ethylene tetrafluoroethylene conductor coating. Female gender (hazard ratio 2.7; 95% confidence interval 1.1-6.7; P = .04) and age (hazard ratio 0.95; 95% confidence interval 0.92-0.97; P < .001) were multivariate predictors of lead failure. By using log-log analysis, we noted that the rate of Riata lead failure initially increased exponentially with a power of 2.1 but leads surviving past 4 years had a linear pattern of lead failure with a power of 1.0. Younger age and female gender are independent predictors of Riata lead failure. Loss of integrity of conductor cables with ethylene tetrafluoroethylene coating is an important mode of electrical failure of the Riata lead. Further study of Riata lead failure trends is warranted to guide lead management.

Trends in Fidelis Lead Survival

Background— The Sprint Fidelis implantable cardioverter-defibrillator lead was recalled in 2007 because of an elevated risk of lead fracture. Several studies have demonstrated an accelerating risk of lead failure over time. We sought to identify predictors and characterize trends of Fidelis lead failure. Methods and Results— We evaluated 604 Fidelis leads with ≥90 days of follow-up implanted at our institution. Fidelis lead survival was analyzed by the Kaplan-Meier method. Analysis of log-log plots of cumulative hazard plots was performed to assess changes in lead failure rate over time. During follow-up of 3.3±1.7 years, 51 (8.4%) Fidelis lead failures were identified. The 3-year and 5-year Fidelis lead survival rates were 93.5% and 85.3%, respectively. Female sex was the only significant predictor of lead failure (heart rate, 2.1; 95% CI, 1.1–3.9; P &lt;0.0001). The rate of lead failure initially increased exponentially with a power of 2.3 (95% CI, 2.22–2.43; P &lt;0.0001). However, log-log analysis of cumulative hazard for leads functioning at 2 and 4 years revealed a stable rate of failure of 4.5%/year. Mathematical modeling of the Fidelis lead failure demonstrated a transition from an exponential to linear pattern of lead failure at 2.9 years. Conclusions— After 3 years, failure rates of Fidelis leads stabilize but at a significantly elevated rate. Female sex is associated with a doubling of the risk of Fidelis lead failure. These findings have implications for Fidelis lead management decisions that are based on the prediction of lead failure risk.

Cloud point and solvent extraction study of uranium(VI) by 8-hydroxyquinoline

BACKGROUND: Cloud point extraction (CPE) is an attractive alternative to solvent extraction. However, comparisons between both techniques are lacking. In this paper, the extraction of uranium(VI) using 8-hydroxyquinoline (HQ) as chelating agent was studied by CPE using Triton X-114 as non-ionic surfactant and by solvent extraction using CHCl3 as diluent. RESULTS: Using CPE, a quantitative extraction was observed for pH higher than 4.5 with a HQ/U ratio of 10. Using solvent extraction an increase in the HQ/U ratio up to 50 is necessary to obtain a near quantitative extraction. Both extraction systems were then compared with respect to the nature of extracted species, and the extraction constants determined using log-log analysis of the extraction data. In the solvent extraction system, the extracted species were identified as UO2Q2 and the corresponding extraction constant was found to be log kex = − 3.6 ± 0.2 on the molar scale. Considering that UO2Q2 is also the extracted species in CPE, a slightly higher extraction constant, i.e. log kex = − 2.5 ± 0.3, was found. CONCLUSION: Such a small difference in favour of the CPE system may arise from the combination of various phenomena, including effects of temperature and effects of ‘extractant environment’. However, a change in the nature of the extracted species, namely from UO2Q2 in the solvent extraction system to the formation of adducts, i.e. UO2Q2(HQ) and UO2Q2(HQ)2 in the CPE system, due to higher HQ concentration in the surfactant-rich phase compared with chloroform, cannot be precluded, but requires confirmation. Copyright © 2012 Society of Chemical Industry

Predicting marital separation: Do parent–child relationships matter?

This study used a family systems perspective in modeling predictors of marital separation within married-parent families with adolescents. Specifically, we examined whether mother-adolescent closeness and negativity, father-adolescent closeness and negativity, and couple relationship quality (mothers' and fathers' positive marital behaviors) prospectively predicted the likelihood of marital separation, operationalized as the father moving out of the household. Data were derived from the first 4 waves of the National Longitudinal Survey of Youth, 1997 (n = 1649), assessing both biological and stepfather families. Results from complementary log-log analyses revealed that marital separations were related to complex family relationships. Specifically, greater mother-adolescent closeness predicted a higher likelihood of marital separation, whereas greater father-child closeness predicted a lower likelihood. In addition, mothers' more positive marital behaviors toward fathers predicted a lower likelihood of marital separation. Patterns were largely similar between biological and stepfather families, with the exception that mothers' positive marital behaviors toward fathers were more influential within biological father families.

Study on the Cloud Point Extraction of Gd(III) with 8-Hydroxyquinoline

The extraction of gadolinium was studied using Cloud Point Extraction (CPE) with 8-hydroxyquinoline (8-HQ) as a chelating agent. The structure of the extracted Gd3+ complex with 8-HQ in the micelle of Triton X114 was determined using log-log analysis of the extraction data. A ratio of 8-HQ to Gd3+ of 3:1 was found. The CPE results were compared with those obtained by classical liquid-liquid extraction with chloroform as solvent. The parameters of the extraction process in both media were determined and compared. A quantitative extraction of Gd3+ at pH 5.5 was obtained by CPE using a 8-HQ/Gd3+ ratio of 10 although a 8-HQ/Gd3+ ratio of 500 was necessary for solvent extraction using chloroform as solvent, illustrating an increase of the mass action of extractants when using CPE instead of solvent extraction. Under those conditions, a higher extraction constant was determined for CPE compared with solvent extraction even if the formation of adducts in the CPE system could not be checked experimentally.

Longevity, lipids and C. elegans

Longevity, lipids and C. elegans

Violent Fan Fluctuations: A Diffusion Perspective to Explain Supporters' Violence

In this article, we address the question of how diffusion mechanisms predict the level of violence among soccer fans. We embed possible causes of violent fan behavior in a theoretical framework of diffusion, as social movement scholars deploy it to study other instances of collective violence. Four possible diffusion explanations are examined: social status of transmitters (both other fan-sides as well as soccer players), status similarity of adopter and transmitter, direct ties as captured by geographical distance, and indirect ties as measured by media coverage. These explanations are tested for the occurrence of violence around soccer matches in the Netherlands during the period 2001-2005. We employ a pooled complementary log-log analysis of fourteen teams over two hundred match weeks and control for repression, city size, and several match characteristics. We find considerable evidence for three of the four proposed explanations and demonstrate that aggressive play on the pitch, hooliganism by fan-sides with similar status, and media coverage are significant explanatory factors for the evolution of fan violence.

Extraction of thorium(IV) and europium(III) by a phosphorylated calix[4]arene in dichloromethane

The extractive properties of 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetrakis(diphenylphosphinoylmethoxy)calix[4]arene towards thorium(IV) and europium(III) ions are studied. The conventional log-log analysis of the extraction data reveals that the stoichiometry of the extracted species is 1 : 1 metal ion to ligand ratio for the two metals. The effects of ligand concentration, types of diluent and concentration of the salting-out agents are investigated and discussed. The selectivity of the ligand for thorium and europium ions versus Mn2+, Pb2+, Cd2+, Fe2+, Ni2+ and Co2+ is examined.

Thermodynamics of the solvent extraction of thorium and europium nitrates by neutral phosphorylated ligands

Solvent extraction of tetravalent thorium and trivalent europium ions from nitrate media into dichloromethane solution of triphenylphosphine oxide (TPPO) has been studied. The extractant was shown to be more efficient for europium than for thorium. A conventional log-log analysis reveals that the extraction of both metal nitrates takes place via the formation of the species with 1 : 2 metal to ligand ratio. Thermodynamic parameters i.e., ΔG°, ΔH° and ΔS° of the extraction process using 1,2-dichloroethane as diluent have been calculated based on the influence of the temperature on extraction equilibria in the range 293-313 K. While the extraction of europium is controlled by enthalpy changes, the extraction of thorium is an endothermic process and is driven by entropy changes. A comparison of these data with those obtained for the extraction of europium and thorium nitrates by two other related phosphorylated ligands, tri-n-octylphosphine oxide (TOPO) and diphenyl-N,N-dimethylcarbamoylmethylphosphine oxide (DФDMCMPO), indicates that DФDMCMPO coordinates presumably as a chelating ligand.

Magnon-polaron and spin-polaron signatures in the specific heat and electrical resistivity ofLa0.6Y0.1Ca0.3MnO3in zero magnetic field and the effect ofMn—O—Mnbond environment

$La_{0.6}Y_{0.1}Ca_{0.3}MnO_{3}$, an $ABO_{3}$ perovskite manganite oxide, exhibits a non trivial behavior in the vicinity of the sharp peak found in the resistivity $\rho$ as a function of temperature $T$ in zero magnetic field. The various features seen on $d\rho/dT$ are discussed in terms of competing phase transitions. They are related to the $Mn-O-Mn$ bond environment depending on the content of the $A$ crystallographic site. A Ginzburg-Landau type theory is presented for incorporating concurrent phase transitions. The specific heat $C$ of such a compound is also examined from 50 till 200 K. A log-log analysis indicates different regimes. In the low temperature conducting ferromagnetic phase, a collective magnon signature ($C \simeq T^{3/2}$) is found as for what are called magnon-polaron excitations. A $C \simeq T^{2/3}$ law is found at high temperature and discussed in terms of the fractal dimension of the conducting network of the weakly conducting (so-called insulating) phase and Orbach estimate of the excitation spectral behaviors. The need of considering both independent spin scattering and collective spin scattering is thus emphasized. The report indicates a remarkable agreement for the Fisher-Langer formula, i.e. $C$ $\sim$ $d\rho/dT$ at second order phase transitions. Within the Attfield model, we find an inverse square root relationship between the critical temperature(s) and the total local $Mn-O-Mn$ strain.

Charge transport in vacuum-sublimed films of metal-free tetraphenylporphyrin and its relation to capacitance and photocurrent measurements

Drift mobilities (μ) of holes and electrons in vacuum-sublimed films of metal-free tetraphenylporphyrin (H 2TPP) were measured by using a time-of-flight technique with a log-log analysis of photocurrent transients with an electric field ( E) and temperature as parameters. Extrapolation of a plot of log μ vs. E 1/2 to E = 0 yielded a very small μ value of the order 10 -16 cm 2 V -1 s -1 for hole and electron transport in the H 2TPP film at 20°C. Field and temperature dependencies of the hole mobilities, analyzed on the basis of the disorder formalism of Bässler and his coworkers, revealed that the extremely slow hole transport in the H 2TPP films was characterized by the largest energetic disorder parameter of 0.22 eV among those reported for other media so far. In addition, measurements of capacitances and photocurrents due to an Al/H 2TPP Schottky junction were carried out with photovoltaic cells of Al/H 2TPP/Au. The lack of dependencies of the capacitances on the frequency and bias voltage was interpreted in terms of the low mobilities of holes in the H 2TPP films. A marked increase of photocurrents with time paralleled a mobility increase, suggesting an important role of carrier mobilities in the mechanism of photocurrent generation in molecular semiconductors.

Separation of Zirconium(IV) and Hafnium(IV) by Extraction Chromatography Using Di(l-methylheptyl) Methylphosphonate as a Stationary Phase

The extraction chromatographic behavior of zirconium(IV) and hafnium(lV) was investigated using di(1-methylheptyl) methylphosphonate (DM HP) as a stationary phase in the media of hydrochloric acid-ammonium chloride by a batch method. Through a log-log analysis and the IR spectra the extractable species has been proposed to be (DMHPH + ) 2 ZrCl 6 2- and (DMHPH + ) 2 HfCl 6 2- . The quantitative separation of Zr(lV) and Hf(IV) with ratios of 1:1 to 100 : 1 from each other has been achieved by DMHP-extraction chromatography.