Perceived state of self during motion can differentially modulate numerical magnitude allocation

Although a direct relationship between numerical allocation and spatial attention has been proposed, recent research suggests that these processes are not directly coupled. In keeping with this, spatial attention shifts induced either via visual or vestibular motion can modulate numerical allocation in some circumstances but not in others. In addition to shifting spatial attention, visual or vestibular motion paradigms also (i) elicit compensatory eye movements which themselves can influence numerical processing and (ii) alter the perceptual state of ‘self’, inducing changes in bodily self‐consciousness impacting upon cognitive mechanisms. Thus, the precise mechanism by which motion modulates numerical allocation remains unknown. We sought to investigate the influence that different perceptual experiences of motion have upon numerical magnitude allocation while controlling for both eye movements and task‐related effects. We first used optokinetic visual motion stimulation (OKS) to elicit the perceptual experience of either ‘visual world’ or ‘self’‐motion during which eye movements were identical. In a second experiment, we used a vestibular protocol examining the effects of perceived and subliminal angular rotations in darkness, which also provoked identical eye movements. We observed that during the perceptual experience of ‘visual world’ motion, rightward OKS‐biased judgments towards smaller numbers, whereas leftward OKS‐biased judgments towards larger numbers. During the perceptual experience of ‘self‐motion’, judgments were biased towards larger numbers irrespective of the OKS direction. Contrastingly, vestibular motion perception was found not to modulate numerical magnitude allocation, nor was there any differential modulation when comparing ‘perceived’ vs. ‘subliminal’ rotations. We provide a novel demonstration that numerical magnitude allocation can be differentially modulated by the perceptual state of self during visual but not vestibular mediated motion.     

Left ventricular isovolumic flow sequence during sinus and paced rhythms: new insights from use of high-resolution Doppler and ultrasonic digital particle imaging velocimetry.

OBJECTIVES: We sought to clarify the role of isovolumic intervals during a cardiac cycle by in vivo visualization of left ventricular (LV) intracavitary flow dynamics. BACKGROUND: Asynchronous LV deformation during isovolumic contraction (IVC) and isovolumic relaxation (IVR) might represent a transient feature of myocardial wall mechanics that reverses the direction of blood flow. METHODS: In 10 beating porcine hearts, the changes in LV intracavitary flow were recorded at baseline and after LV epicardial and right atrial pacing with high-resolution Doppler and contrast echocardiography. Two-dimensional vector flow fields were generated offline from B-mode contrast images with particle imaging velocimetry. RESULTS: During IVC, flow from the LV apex accelerated toward the base, whereas blood from the base was redirected toward the outflow through formation of an anterior vortex. Conversely, during IVR, flow was initially directed toward the apex and then briefly reversed toward the base. Epicardial pacing from the LV base altered the stages of flow redirection during the pre-ejection period and delayed mitral valve closure (28 +/- 14 ms vs. 61 +/- 13 ms, p < 0.001) and aortic valve opening (77 +/- 18 ms vs. 111 +/- 18 ms, p = 0.004). CONCLUSIONS: Isovolumic intervals are not periods of hemodynamic stasis but, rather, phases with dynamic changes in intracavitary flow. Experimentally induced aberrant epicardial electrical activation alters stages of flow redirection and prolongs the pre-ejection period. Normal electromechanical activation through the His-Purkinje system in mammalian hearts maintains an inherent synchrony with the sequence of intracavitary flow redirection.     

Prevalence of hepatitis B among Afghan refugees living in Balochistan, Pakistan.

OBJECTIVE: Continued civil war and political instability in Afghanistan have lead to a huge influx of refugees into the neighboring provinces in Pakistan. This study was conducted to estimate seroprevalence of hepatitis B and to identify potential risk factors for hepatitis B virus (HBV) transmission among the refugees living in the camps of Balochistan Province, Pakistan. METHODS: A cross-sectional survey of hepatitis B surface antigen (HBsAg) was conducted during October 2003. We obtained the registration list to select families randomly from the refugee camps. A husband, wife and one of their children, selected at random, were enrolled in the study. Study subjects with positive laboratory results for HBsAg were compared with those who were negative for HBsAg. RESULTS: Field workers interviewed 301 families with a total of 903 study subjects. Blood specimens of 75 study subjects (8.3%, 95% CI 6.6-10.3) were positive for HBsAg. There were 37 husbands (12.3%, 95% CI 7.2-14.4) and 21 wives (7.0%, 95% CI 4.5-10.6) positive for HBsAg. Out of 301 children, 17 (5.6%, 95% CI 3.4-9.1) were positive for HBsAg. Receiving more than ten injections during the previous year increased the risk of HBV infection (OR 3.5, 95% CI 1.8-6.7). A child positive for HBsAg was more likely to have a positive parent compared to an HBsAg negative child (OR 5.7, 95% CI 2.0-16.5). CONCLUSION: Hepatitis B is highly endemic among Afghan refugees living in these camps. Unsafe injection practices will continue to cause a steady increase in the magnitude of this health problem until appropriate control measures are taken. The possibility of mother-to-child transmission underscores the need to include vaccination against hepatitis B as part of routine immunization in this population.     

Increased incidence of life-threatening ventricular arrhythmias in implantable defibrillator patients after the World Trade Center attack

OBJECTIVES: This study was designed to evaluate whether the destruction of the World Trade Center (WTC) on September 11, 2001 (9/11), led to an increased frequency of ventricular arrhythmias among patients fitted with an implantable cardioverter-defibrillator (ICD). BACKGROUND: The WTC attack induced psychological distress. Because ICDs store all serious arrhythmias for months, the attack provided a unique opportunity to compare pre- and post-9/11 frequencies of potentially lethal arrhythmias among ICD patients. METHODS: Two hundred consecutive ICD patients who presented for regularly scheduled follow-up to six affiliated clinics were recruited into this observational study. The electrograms stored in the ICDs for the three months before 9/11 and 13 months thereafter were scrutinized in a blinded manner (relative to date) for all ventricular tachyarrhythmias (tachycardia or fibrillation) triggering ICD therapy. RESULTS: The frequency of tachyarrhythmias increased significantly for the 30 days post-9/11 (p = 0.004) relative to all other months between May 2001 and October 2002. In the 30 days post-9/11, 16 patients (8%) demonstrated tachyarrhythmias, compared with only seven (3.5%) in the preceding 30 days, representing a 2.3-fold increase in risk (95% confidence interval 1.1 to 4.9; p = 0.03). The first arrhythmic event did not occur for three days following 9/11, with events accumulating in a progressive non-clustered pattern. CONCLUSIONS: Ventricular arrhythmias increased by more than twofold among ICD patients following the WTC attack. The delay in onset and the non-clustered pattern of these events differ sharply from effects following other disasters, suggesting that subacute stress may have served to promote this arrhythmogenesis.     

Association of chronic kidney disease with atrial fibrillation among adults in the United States: REasons for Geographic and Racial Differences in Stroke (REGARDS) Study

BACKGROUND: Atrial fibrillation (AF) is common among patients with end-stage renal disease, but few data are available on its prevalence among adults with chronic kidney disease (CKD) of lesser severity. methods and results: We evaluated the association of CKD with ECG-detected AF among 26 917 participants in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study, a population-based cohort of African-American and white US adults ≥45 years of age. Estimated glomerular filtration rate (eGFR) was calculated using the abbreviated Modification of Diet in Renal Disease study equation and albuminuria was defined as a urinary albumin to creatinine ratio ≥30 mg/g. Participants were categorized by renal function: no CKD (eGFR ≥60 mL/min/1.73 m(2) without albuminuria, n=21 081), stage 1 to 2 CKD (eGFR ≥60 mL/min/1.73 m(2) with albuminuria n=2938), stage 3 CKD (eGFR 30 to 59 mL/min/1.73 m(2), n=2683) and stage 4 to 5 CKD (eGFR <30 mL/min/1.73 m(2), n=215). The prevalence of AF among participants without CKD, and with stage 1 to 2, stage 3, and stage 4 to 5 CKD was 1.0%, 2.8%, 2.7% and 4.2%, respectively. Compared with participants without CKD, the age-, race-, and sex-adjusted odds ratios for prevalent AF were 2.67 (95% confidence interval, 2.04 to 3.48), 1.68 (95% confidence interval, 1.26 to 2.24) and 3.52 (95% confidence interval, 1.73 to 7.15) among those with stage 1 to 2, stage 3, and stage 4 to 5 CKD. The association between CKD and prevalent AF remained statistically significant after further multivariable adjustment and was consistent across numerous subgroups. CONCLUSIONS: Regardless of severity, CKD is associated with an increased prevalence of AF among US adults.     

Epidemiologic attributes of invasive non-typhoidal Salmonella infections in Michigan, 1995--2001.

OBJECTIVES: To determine: (1) the incidence of invasive salmonellosis, (2) the distribution of specific Salmonella serotypes associated with invasive disease, and (3) the role of demographic characteristics in invasive salmonellosis in Michigan. DESIGN: We conducted a cross-sectional study using laboratory-confirmed cases of salmonellosis reported to the Michigan Department of Community Health between 1995 and 2001. METHODS: Average annual incidences (AAIs) for invasive salmonellosis were computed, and Poisson regression analysis was used to model the association between demographic attributes and invasive salmonellosis. RESULTS: Of 6797 cases of salmonellosis, 347 (5.1%) were characterized as invasive having an AAI of 0.5/100000. A covariate-adjusted Poisson model showed children aged <1 year to be at higher risk for invasive salmonellosis compared to adults aged 40-49 years (rate ratio (RR) 8.98, 95% confidence interval (CI) 5.69-14.17). No significant differences were found between males and females (RR 1.02, 95% CI 0.83-1.26), African-Americans and Caucasians (RR 0.95, 95% CI 0.64-1.42), and urban and rural residents (RR 0.98, 95% CI 0.76-1.26). Among the most common serotypes associated with invasive salmonellosis (Heidelberg, Typhimurium, and Enteritidis), Salmonella serotype Heidelberg had the highest blood invasiveness ratio (15.79/100). CONCLUSIONS: Children aged <1 year, especially of minority groups, are at higher risk for invasive Salmonella infections. Invasive salmonellosis may be included in the differential diagnosis of acute bacterial infections in young children with positive stool cultures for Salmonella.     

A mechanobiochemical mechanism for monooriented chromosome oscillation in mitosis

During mitosis, the condensed chromosomes undergo a series of spectacular oscillations after they are captured in an end-on manner by kinetochore microtubules (KMT) emanating from the spindle poles. Such oscillations are commonly attributed to tug-of-war-like mechanisms, where the mechanical force imbalance alone drives the chromosome movement. However, a large portion of the force imbalance upon the chromosome is absorbed by the kinetochore and may not drive chromosome movement directly. Mounting evidence suggests that such resistance by the kinetochores regulates the chemical reactions of KMT plus-end growth and shrinkage, which have been shown as the determinant of the chromosome antipoleward (AP) and poleward movements. Here we incorporate this important regulatory feature, propose a mechanobiochemical feedback mechanism, and apply it to the monooriented chromosome oscillation, the early stage of the series of observed chromosome oscillations. In this model, the mechanical movement of the chromosome and the local biochemical reactions at the attached kinetochore region form a feedback loop that drives the oscillation. The force imbalance exerted on the chromosomes provides a bias (via mechanically sensitive proteins) on the local biochemical reactions controlling the KMT plus-end dynamics, and the movement of the chromosome in turn changes the forces exerted on it through the experimentally supported gradient in AP force. The proposed feedback mechanism can generate oscillatory behavior that depends on the topology of the feedback loop but is largely independent of the detailed molecular mechanism. We suggest potential molecular players, whose perturbation may allow direct experimental tests of the model.     

The synthesis and application of (E)-N′-(benzo[d]dioxol-5-ylmethylene)-4-methyl-benzenesulfonohydrazide for the detection of carcinogenic lead

In this study, noble ligands of (E)-N′-(benzo[d]dioxol-5-ylmethylene)-4-methyl-benzenesulfonohydrazide (BDMMBSH) were prepared via a simple condensation method using benzo-[d][1,3]-dioxole carbaldehyde, benzenesulfonylhydrazine (BSH), and 4-methyl-benzenesulphonylhydrazine (4-MBSH) in good yield, which were crystallized in acetone, EtOAc, and EtOH. The BDMMBSH derivatives were characterized using different spectroscopic techniques, such as ¹H-NMR, ¹³C-NMR, FTIR, and UV-Vis spectroscopy, and their crystal structures were analyzed using the single crystal X-ray diffraction method (SCXRDM). Subsequently, the BDMMBSH compounds were used for the significant detection of the carcinogenic heavy metal ion, lead (Pb²⁺), via a reliable electrochemical approach. A sensitive and selective Pb²⁺ sensor was developed via the deposition of a thin layer of BDMMBSH on a GCE with the conducting polymer matrix Nafion (NF). The sensitivity, LOQ, and LOD of the proposed sensor towards Pb²⁺ were calculated from the calibration curves to be 2220.0 pA μM⁻¹ cm⁻², 320.0 mM, and 96.0 pM, respectively. The validation of the BDMMBSH/GCE/NF sensor probe was performed via the selective determination of Pb²⁺ in spiked natural samples with a satisfactory and rational outcome.

A sensitive cationic sensor was developed by BDMMBSH onto GCE with 5% Nafion using electrochemical method, which was validated with the selective determination of Pb²⁺ in spiked samples and found satisfactory results.     

From the Cover: Global inequality remotely sensed

Economic inequality is notoriously difficult to quantify as reliable data on household incomes are missing for most of the world. Here, we show that a proxy for inequality based on remotely sensed nighttime light data may help fill this gap. Individual households cannot be remotely sensed. However, as households tend to segregate into richer and poorer neighborhoods, the correlation between light emission and economic thriving shown in earlier studies suggests that spatial variance of remotely sensed light per person might carry a signal of economic inequality. To test this hypothesis, we quantified Gini coefficients of the spatial variation in average nighttime light emitted per person. We found a significant relationship between the resulting light-based inequality indicator and existing estimates of net income inequality. This correlation between light-based Gini coefficients and traditional estimates exists not only across countries, but also on a smaller spatial scale comparing the 50 states within the United States. The remotely sensed character makes it possible to produce high-resolution global maps of estimated inequality. The inequality proxy is entirely independent from traditional estimates as it is based on observed light emission rather than self-reported household incomes. Both are imperfect estimates of true inequality. However, their independent nature implies that the light-based proxy could be used to constrain uncertainty in traditional estimates. More importantly, the light-based Gini maps may provide an estimate of inequality where previously no data were available at all.

Over the past decades, there has been a transition from theoretical to data-driven inequality research (1). However, progress is limited by a lack of data on economic prosperity at the household level (2) as well as the absence of consensus on ways of measuring economic inequality (3, 4). Practical constraints include limited coverage, incomparability at population subscales, dependence on misreported income surveys, and low-quality data collection in developing economies (5–7). Furthermore, since traditional inequality measures are not georeferenced at different geographic scales, they cannot be used in subregional studies. Thus, despite broad interest in inequality, empirical approaches remain contentious (8). Since the late twentieth century, initiatives like the World Income Inequality Database, the Luxembourg Income Study Database, and the World Wealth and Income Database have partly filled this lacuna. However, these datasets still suffer from large regional variations in coverage, data quality, and lack of compatibility concerning collection methodologies (9, 10). The vast majority of publications in inequality research are based on data from North America and Western Europe (11). As a result, while inequality in the developed world is relatively well documented (12–14), our knowledge about inequality in the developing world is limited by paucity, poor quality, uncertainty, and incomparability of data (15, 16). This implies that we know the least about areas where inequality perhaps presents the most serious developmental policy challenge.Here, we suggest a way to use remotely sensed nighttime light (NTL) for filling this gap. NTL is a globally uniform metric reflecting the nocturnal anthropogenic use of lights (17, 18). Almost all economic activities occurring in postdaylight hours, be it consumption or production, require the use of artificial lights, an assertion corroborated by studies showing NTL to be highly related with indicators of economic activity (19–22).