Upward Slope Research Articles

Is There a Cigarette Catch-Up Effect for Biracial Black Youth?

Introduction: The catch-up effect is a phenomenon in which the tobacco-use prevalence rates of White individuals are initially greater than the rates of Black individuals, but by the time the youth enter young adulthood, the prevalence rates for Black individuals catch up to or exceed the cigarette-use rates of White individuals. We test the catch-up effect by comparing the cigarette trajectories of monoracial and biracial Black adolescents with the trajectories of White adolecents. Methods: We used longitudinal data from the National Longitudinal Study of Adolescent and Adult Health. Our sample includes 9421 respondents. Study hypotheses are tested using latent growth curve modeling. Results: Findings revealed a catch-up effect for two of four outcomes. The catch-up effect was observed most often for Black individuals. Black and Black-Hispanic individuals showed cigarette smoking patterns consisted of a catch-up effect while Black-American individuals showed smoking patterns consisted of a cross-over effect. Black and Black-American Indian individuals showed a stark contrast to the typical bell-shaped curve with substance use patterns demonstrating upward slope trajectories. Conclusions: Interventions to prevent and reduce tobacco use in these populations are warranted.

Theoretical Calculation and Simulation Analysis of Axial Static Stiffness of Double-Nut Ball Screw with Heavy Load and High Precision

Double-nut ball screws bear the action of bidirectional pretightening force, leading to the deformation of the contact area between the ball and the raceway. Under this condition, it is important to analyze and calculate the static stiffness of the ball screw. However, the conventional calculation method is inaccurate. Hence, a new method for the static stiffness analysis of a double-nut ball screw is proposed. Through the structural analysis of the ball screw and internal load distribution, a load deformation model was established based on the Hertzian contact theory. Through the load analysis of the ball screw, a static stiffness model of the ball screw was established and applied to a case study and a finite element simulation. The rigidity of THK double-nut ball screws used in the X-axis feed system of a high-stiffness heavy-duty friction stir welding robot (developed by the research group) was calculated. When the workload was lower than 1.1 × 104 N, the slope of the double-nut static stiffness curve increased significantly with the increase in the workload, and when the workload was greater than 1.1 × 104 N, its upward slope tended to stabilize. The simulated and experimental stiffness curves were in good agreement; when the external axial load was greater than 2.8 × 104 N, the stiffness value calculated using the finite element method gradually converged to the theoretical value; and when the axial load reached 3.0 × 104 N, the simulation and test curves matched well. The analysis method of the double-nut ball screw was found to be concise and accurate, and the stiffness curves calculated using the two methods were consistent. The simulation analysis of the static stiffness presented herein is expected to aid the design of double-nut ball screws of high-rigidity heavy-duty equipment.

Aggregate Hazes in Exoplanet Atmospheres

Abstract Photochemical hazes have frequently been used to interpret exoplanet transmission spectra that show an upward slope toward shorter wavelengths and weak molecular features. While previous studies have only considered spherical haze particles, photochemical hazes composed of hydrocarbon aggregate particles are common throughout the solar system. We use an aerosol microphysics model to investigate the effect of aggregate photochemical haze particles on the transmission spectra of warm exoplanets. We find that the wavelength dependence of the optical depth of aggregate particle hazes is flatter than for spheres because aggregates grow to larger radii. Consequently, while spherical haze opacity displays a scattering slope toward shorter wavelengths, aggregate haze opacity can be gray in the optical and near-infrared, similar to those assumed for condensate cloud decks. We further find that haze opacity increases with increasing production rate, decreasing eddy diffusivity, and increasing monomer size, although the magnitude of the latter effect is dependent on production rate and the atmospheric pressure levels probed. We generate synthetic exoplanet transmission spectra to investigate the effect of these hazes on spectral features. For high haze opacity cases, aggregate hazes lead to flat, nearly featureless spectra, while spherical hazes produce sloped spectra with clear spectral features at long wavelengths. Finally, we generate synthetic transmission spectra of GJ 1214b for aggregate and spherical hazes and compare them to space-based observations. We find that aggregate hazes can reproduce the data significantly better than spherical hazes, assuming a production rate that is limited by delivery of methane to the upper atmosphere.

Treating T2DM by ensuring insulin access is a global challenge.

As the global increase in type 2 diabetes mellitus has a steep upward slope, meeting the worldwide demand for insulin is an international challenge. Sanjay Basu and colleagues used microsimulation to create scenarios that can inform the design of health-care strategies and insulin requirements for governments and the national and international organizations responsible for formulating treatment guidelines.

Effect of spectral measurement orientation on online prediction of soluble solids content of apple using Vis/NIR diffuse reflectance

The effect of variation of fruit orientation on online prediction of soluble solids content (SSC) of ‘Fuji’ apples based on visible and near-infrared (Vis/NIR) spectroscopy was studied. The diffuse reflectance spectra in 550–950 nm were collected with a designed online system in six orientations: stem-calyx axis vertical with stem upward (T1) and stem downward (T5), 45° between stem-calyx axis and horizontal with stem slope upward (T2) and stem slope downward (T4), stem-calyx axis horizontal with stem towards computer side lights (T3), stem-calyx axis horizontal with stem towards belt movement direction (T6). The 180 samples with SSC range of 8.00–13.60°Brix were divided into 135 of calibration set with 1.09 standard deviation (S.D.) and 45 of prediction set with 0.85 S.D. The signal-to-noise ratio (SNR) and area change rate (ACR) were used to evaluate the stability of collected spectra. After the comparison of different preprocessing methods, partial least squares (PLS) and least squares-support vector machine (LS-SVM) were used to develop compensation models of SSC for each orientation separately (local models) and all orientations (global model), respectively. Finally, competitive adaptive reweighted sampling (CARS), successive projection algorithm (SPA), and their combination were used to select the effective wavelengths (EWs), respectively. Results showed that T1 performed better for our system and influence of measurement orientation on spectra greatly affected SSC prediction accuracy. Comparatively, global model was insensitive to fruit orientation variation. 37 EWs selected by CARS-SPA-PLS model after Savitzky-Golay smoothing in all orientations achieved better results with rp and RMSEP of 0.815, 0.818, 0.837, 0.731, 0.807, 0.842 and 0.487, 0.484, 0.460, 0.573, 0.497, 0.453°Brix, respectively. Generally, global model with EWs could be promisingly used for online SSC prediction of apple.

Multiple spatial–temporal scale change patterns of rainfall erosivity in China over past 58 years based on gravity centre model

The rainfall erosivity in China have shown different change characteristics and patterns at different spatial–temporal scales. In this article, we introduced a gravity centre model for use in studying and analyzing the spatial–temporal distribution patterns of rainfall erosivity in China in the past 58 years combined with traditional geostatistical analysis methods at different spatial–temporal scales. During 1961–2018, rainfall erosivity in China showed a decreasing trend from southeast to northwest in spatial distribution. Moreover, the spatial distribution patterns of the annual average rainfall erosivity had been negatively affected by altitude. In terms of interannual variability, rainfall erosivity had shown a fluctuating upward trend in the past 58 years, with a steep upward slope in 1982 and a steep downward slope in 1990. In the past 58 years, the gravity centre of rainfall erosivity in China had moved southeastward, which indicated that the increment and increasing rate of rainfall erosivity in eastern and southern China were greater than those in western and northern China. These results could provide important data to support decisions regarding the prevention and control of soil erosion at regional and national scales.

Association between gestation length and lactation performance, lactation curve, calf birth weight and dystocia in Holstein dairy cows in Iran.

In this study, 252,798 lactations on 108,077 cows in 433 herds were used to determine the association between gestation length (GL) and lactation performance, lactation curve, calf birth weight and dystocia in Holstein dairy cows in Iran. The GL averaged 278.1 ± 5.41 d, was categorized as short (SGL; at 1 SD below the population mean), average (AGL; the population mean ± 1 SD), or long (LGL; at least 1 SD above the population mean). Factors including parity, calf gender and calving season were associated with the GL. Primiparous cows with SGL had less lactation performance than those with longer GL; however, there was no difference between those with AGL and LGL. Multiparous cows with longer GL always had more partial and 305-d lactation performance. Primiparous cows with SGL produced less milk at the beginning of lactation and at the peak than those with AGL or LGL; inverse trends were found for lactation persistency, upward and downward slopes of the lactation curve. Within multiparous, a direct relationship was found between GL and the peak yield, where cows with longer GL always produced more milk at the peak. Multiparous cows with SGL produced less milk at the beginning of lactation, reached their peaks later, had higher lactation persistency and showed a lower upward slope of lactation curve than those with AGL or LGL. There was a direct relationship between GL and calf birth weight, where cows with longer GL had calves with more weight at the birth. Within primiparous, cows with SGL had the lowest and those with LGL had the highest rate of dystocia. However, multiparous cows with AGL had a lower rate of dystocia than those with SGL or LGL. Although there was a direct relationship between GL and lactation performance, intermediate GL seems optimal when considering dystocia.

Automatic Identification of S1 and S2 Heart Sounds Using Simultaneous PCG and PPG Recordings

Accurate and reliable identification of the first (S1) and second (S2) sounds of the phonocardiogram (PCG) is still a challenging task due to the presence of the S3 and S4, murmurs, high-pitched sounds, physiological interference, and other environmental noises. This paper presents an automated method for identification of the S1 and S2 sounds by simultaneously recording, processing, and fusing the extracted fiducial points of the PCG and photoplethysmogram (PPG) signals. The method consists of four main stages: the PCG and PPG signal sensing with Arduino interfacing, the heart sound delineation (HSD) and pulse waveform delineation (PWD) using variational mode decomposition (VMD), and the S1/S2 identification based on the estimated timings of the pulse onset, peak, upward slope zerocrossing, and downward slope zerocrossing of the pulsatile waveform. The accuracy and robustness of the HSD and PWD algorithms are evaluated using both the benchmark databases and simultaneous PCG and PPG recordings. Then, the proposed S1/S2 identification method is evaluated using the simultaneous PCG and PPG recordings. The VMD-based HSD algorithm achieves an average sensitivity (SE) = 99.80%, positive predictivity (PP) = 99.0%, and accuracy (ACC) = 98.81% whereas the Gaussian derivative filter (GDF)-based HSD and bandpass filter (BPF)-based HSD algorithms achieve the average SE = 99.75%, PP = 93.59%, and ACC = 93.37% and the average SE = 99.67%, PP = 84.97%, and ACC = 84.73%, respectively, for the recorded PCG signals with SNR value of 5 dB. The proposed S1/S2 identification method achieves a correct identification rate of 99.75% which outperforms the GDF+systole interval(SI)/diastole interval(DI) and the BPF+SI/DI feature-based methods having 66% and 59.25%, respectively, in the case of noisy recordings with a SNR value of 5 dB. The proposed method has great potential in improving the identification accuracy and robustness in the presence of other sounds and murmurs, and different kinds of environmental noises.

Use of cumulative summation (CUSUM) as a tool for early feedback and monitoring in robot-assisted radical prostatectomy outcomes and performance.

Today's surgical practice has evolved, with increasing emphasis on quality assurance. Many forms of quality-control monitoring have been suggested, but they are often impractical or difficult to implement. Cumulative summation (CUSUM) is a simple method to provide visual feedback before significant quality issues arise. We present our initial use and practical application of CUSUM in a surgical practice. A retrospective analysis was applied to a prospectively collected database of 577 sequential patients who have undergone robot-assisted radical prostatectomy from a single surgeon over a 10-year period. Outcome measures were analyzed with CUSUM, which included a composite complication score, continence rates, length of hospital stay, biochemical recurrence, and need for adjuvant radiation. If any outcomes were out of control, they would cross the CUSUM failure line. CUSUM chart-plotting for incontinence demonstrated an initial upward slope followed by trending to a new safety limit. Additionally, outcomes in complications and biochemical recurrence did not reach the established safety boundaries. Length of stay and radiation outcomes did initially cross the safety line, but were improved over time. The use of CUSUM in clinical practice can fulfill the need for quality assurance. CUSUM plotting in our practice reflected the initial learning curve, followed by ongoing maintenance and improvement in performance. These changes were consistent with the implementation of changes in surgical techniques. Although this tool was used retrospectively, this strengthens our argument to implement the tool prospectively and assess real-time refinement of surgeon skill. We have demonstrated that CUSUM can be appropriately used to assure quality control in a surgical practice.

Rethinking the Use of Seabed Sediment Temperature Profiles to Trace Submarine Groundwater Flow

AbstractSubmarine groundwater fluxes across the seafloor facilitate important hydrological and biogeochemical exchanges between oceans and seabed sediment, yet few studies have investigated spatially distributed groundwater fluxes in deep‐ocean environments such as continental slopes. Heat has been previously applied as a submarine groundwater tracer using an analytical solution to a heat flow equation assuming steady state conditions and homogeneous thermal conductivity. These assumptions are often violated in shallow seabeds due to ocean bottom temperature changes or sediment property variations. Here heat tracing analysis techniques recently developed for terrestrial settings are applied in concert to examine the influences of groundwater flow, ocean temperature changes, and seabed thermal conductivity variations on deep‐ocean sediment temperature profiles. Temperature observations from the sediment and bottom ocean water on the Scotian Slope off eastern Canada are used to demonstrate how simple thermal methods for tracing groundwater can be employed if more comprehensive techniques indicate that the simplifying assumptions are valid. The spatial distribution of the inferred groundwater fluxes on the slope suggests a downward groundwater flow system with recharge occurring over the upper‐middle slope and discharge on the lower slope. We speculate that the downward groundwater flow inferred on the Scotian Slope is due to density‐driven processes arising from underlying salt domes, in contrast with upward slope systems driven by geothermal convection. Improvements in the design of future submarine hydrogeological studies are proposed for thermal data collection and groundwater flow analysis, including new equations that quantify the minimum detectable flux magnitude for a given sensor accuracy and profile length.

Prevalence of signs of celiac axis compression by the median arcuate ligament on computed tomography angiography in asymptomatic patients

ObjectiveThe increasing use of computed tomography (CT) angiography has led to more frequent diagnoses of celiac artery compression (CAC) by the median arcuate ligament (MAL). The signs of CAC by the MAL have been described as stenosis and a hook or J appearance on sagittal views. The importance of the “hook signal,” however, has not been documented by studies of the normal anatomy of the celiac axis. MethodsCT angiography images of 344 completely asymptomatic, live kidney donors (without history of chronic abdominal pain or weight loss) were reviewed. The angle of emergence (AE) of the celiac axis from the aorta and the angle of upward or downward shifting of the celiac axis before its first branch (fold angle [FA]) were measured. Weight, height, and body mass index were obtained from our electronic database, and correlations with the angles measured were tested. The occurrence of stenosis >50% at the origins of the celiac axis was also determined in the sample. ResultsMeasurements were possible in 321 cases. The celiac axis was found to leave the aorta at an angle of <90 degrees in all patients (AE range, 7-83 degrees) and <45 degrees in 292 (90%) patients. The FA ranged from 66 to 208 degrees. Before the first branch, the celiac trunk shifted upward in 306 (95%) patients, remained straight in just one of them, and shifted downward in 14 (4%). The AE was positively correlated with weight in women. The FA was negatively correlated with weight in men and women. Body mass index was positively correlated with AE and negatively correlated with FA in both men and women. In 11 cases (3.4%), stenosis >50% was found at the origin of the celiac axis. In only two patients, the celiac axis had an upward slope after the stenosis, which could be interpreted as a hook shape. ConclusionsThe normal anatomy of the celiac axis, when seen on CT angiography images, demonstrates that it exits the aorta downward and then shifts upward. This hook or J shape should not be interpreted as resulting from external compression. CAC by the MAL occurs in 3.42% of the normal asymptomatic population; a hook or J shape is not visible in most cases in that subgroup.

The ESG Integration Paradox

Today, most investment managers have something to say about environmental, social and governance (ESG) issues, and written ESG policies are ubiquitous.Yet, a written policy is not a reliable indicator of a firm's commitment. Actual ESG incorporation practices vary greatly, with most investment managers falling well short of full integration. Only a few firms seem to be using ESG factors to deliver alpha, hence, the paradox. If not implemented wholeheartedly, responsible investing can lead to lower financial returns. So, why have so few investment managers gone all the way?The paradox involves a “valley” of lower returns where portfolios first absorb the costs of ESG integration before the promised benefits materialize. In the early days of ethical investing, the focus was on using negative screens to exclude certain companies for moral or ethical reasons but lower financial returns are inherent to exclusionary screening.Hard exclusions force managers to tradeoff certain risks for others. So, for example, if the market discounts tobacco stock prices to account for changing consumer behavior, eventually tobacco stock prices become attractive again as, indeed, has been the case over the last two decades. Exclusionary screening alone is a self‐limiting strategy.By contrast, ESG strategies range from active ownership and engagement, to positive screening (selecting for certain attributes), to relative weighting (sometimes called “best‐in‐class selection”), to risk factor investing, to full integration.Because the relationship between an asset manager's ESG efforts and its risk‐adjusted performance is not classically linear, asset owners should look for managers that are on the upward slope of the ESG intensity curve and are fully committed to advancing up it.

P.087 “Reported Brain Injury” Time trends within two Canadian health surveys over two decades

Background: An “epidemic” of concussions has been widely reported. We explored the annual incidence of reported concussion or other brain injury, over 20 years within Canada in order to explore the magnitude of this reported epidemic. Methods: Two Canadian nationally representative health surveys have serially collected injury data associated with disability. The National Population Health Survey (NPHS) (1994-9) collected data on “concussion”, and the Canadian Community Health Survey (CCHS) (2000-current) has collected data on “concussion or other brain injury”. Data on respondents 12 years and older reporting concussion with or without other brain injury within the past year were examined in order to produce serial incidence data. Results: Nationally representative data were available biennially from 1994/95 through 2013/14 with the exception of 2007/08 and 2011/12. The incidence of reported concussions, or concussions and other brain injury has been stable until 2005/06 when the reported annual incidence started an upward slope to levels 250% higher (p&lt;0.001) without any apparent stabilization by 2013/14, when approximately 1 in 200 Canadians 12 years and older report concussion or other brain injury as their most significant injury associated with disability in the previous 12 months. Conclusions: There is currently a pandemic of reported brain injury in Canada.

The Influence of Different Walking Conditions on Walking Parameters

PURPOSE: This study investigated the relationship between characteristics of walking parameters and walking parameters of different walking conditions. METHODS: The participants were 54 university students who had the habit of exercising ( 32 men and 22 women, 19.6 ± 0.7 years). Participants were asked to walk on flat and sloped ground. On the flat ground, they were asked to walk freely with a subjective intensity of “Light (ratings of perceived exertion (RPE) 11)” and “Somewhat hard (RPE 13).” The average slope was 4% for both upward and downward conditions and participants walked freely on both. Participants wore a wearable device attached to the left wrist that measured their walking speed, cadence, stride, and heart rate. RESULTS: On the flat ground, in all walking parameters, RPE 13 showed significantly higher values compared to RPE 11 (walking speed: 5.35 ± 0.49 versus 4.48 ± 0.43 km/h, cadence: 121.9 ± 8.8 versus 113.0 ± 7.3 steps/min, stride: 73.2 ± 6.8 versus 65.8 ± 6.8 cm, respectively; P < 0.05). On the sloped ground, walking speed on the upward slope showed significantly lower values compared to that on the downward slope and the free-walking speed on flat ground(upward slope: 4.85 ± 0.27 km/h, downward slope: 5.27 ± 0.38 km/h, flat ground: 5.25 ± 0.30 km/h). However, heart rate was significantly higher on the upward slope than in other conditions(118.8 ± 16.9 beats/min, 103.5 ± 14.0 beats/min, 107.8 ± 18.2 beats/min, respectively). Multiple regression analysis was performed with walking speed as the dependent variable and cadence and stride as independent variables. Results showed that for walking on the flat ground, the standardized coefficient for stride was higher than that for the cadence under all conditions. Although the same trend was found for walking on downward slopes, for walking on upward slopes, the standardized coefficient for cadence was higher than that for the stride. CONCLUSIONS: Walking parameters tended to be similar for walking on flat ground even when conditions changed; however, it became clear that characteristics of walking parameters on upward slopes varied from those of other conditions.

‘Reported concussion’ time trends within two national health surveys over two decades

ABSTRACTBackground: An ‘epidemic’ of concussions has been widely reported. We examined the annual incidence of reported concussion or other brain injury, over 20 years within Canada in order to explore the magnitude of this reported epidemic.Methods: Two Canadian nationally representative health surveys have serially collected injury data associated with disability. The National Population Health Survey (NPHS) collected data on ‘concussion’ (1994–1999), and the Canadian Community Health Survey (CCHS) collects data on ‘concussion or other brain injury’ (2000–current). Respondents 12 years and older reporting concussion or other brain injury occurring within the previous year were used to produce serial incidence data.Results: Nationally representative data were available biennially from 1994/95 through 2013/14 with the exception of 2007/08 and 2011/12. Reported incidence of concussions, or concussions and other brain injury has been stable until 2005/06 when the reported annual incidence started an upward slope to levels 250% higher without any apparent stabilization by 2013/14, at which time approximately 1 in 200 Canadians 12 years and older reported concussion or other brain injury as their most significant injury associated with disability in the previous year.Conclusions: The current pandemic of reported brain injury in Canada will have implications for health-care delivery.

Impact of combined alignments on lane departure: A simulator study for mountainous freeways

Lane departures are responsible for many side-swipe, rear-end and single-vehicle run-off-road crashes. There is a dearth of research, however, on how lane departures are impacted by roadway alignments. The objective of this paper is to examine which geometric design characteristics, including road alignment at the current segment and the adjacent segments, have significant influence on lane departure. Lane departure data from a total 30 drivers were collected from a driving simulator study of a four-lane (two lanes in each direction) divided mountainous freeway. Lane departures were classified into lane keeping, lane departure to the left and lane departure to the right for all-alignments (Dataset I), and lane keeping, lane departure to the inside and lane departure to the outside for curves-only (Dataset II). A mixed multinomial logit model for each dataset was employed to examine the contributory factors. This approach allows for the possibility that the estimated model parameters can vary randomly to account for unobserved effects potentially relating to heterogeneous driver behaviors. Fixed parameters that had a significant increase on lane departure were horizontal curvature at the current segment, and the difference (max-min) in horizontal curvature within the 300-m adjacent upstream alignment. Downward slope and upward slope with fixed parameters significantly decreased lane departure. Estimated parameters related to the direction of the curve, driving lane (bordering median or hard shoulder) and driving speed had found to have randomly distributed over the drivers. This indicates that driver behavior is not consistent in the effect of these three variables on lane departure. These results can assist engineers in designing safer mountainous freeways.

An Experimental Study on Water Surface Profiles of High Froude Number Flows

Motivated by need to study supercritical overbank flows on floodplain, we experimentally investigate if initially supercritical flow in a rectangular flume would maintain its state throughout. Varying upstream gate opening, flow rate and angle of the slope, a total of 37 experimental cases were carried out. The experimental results are compared to two existing theories: an inviscid theory based on nonlinear shallow water equations and jump conditions and a hydraulic theory that takes friction into account. The experimental data are consistent with the two theories. Flows on downward slope were stable, while those on upward slope had unstable hydraulic jump and transformed into subcritical flow. The reported results should serve well in designing a laboratory flume with the supercritical inflow and in conducting hydraulic model experiments on overbank flows.

Standing on slopes \u2013 how current microprocessor-controlled prosthetic feet support transtibial and transfemoral amputees in an everyday task

BackgroundConventional prosthetic feet like energy storage and return feet provide only a limited range of ankle motion compared to human ones. In order to overcome the poor rotational adaptability, prosthetic manufacturers developed different prosthetic feet with an additional rotational joint and implemented active control in different states. It was the aim of the study to investigate to what extent these commercially available microprocessor-controlled prosthetic feet support a natural posture while standing on inclines and which concept is most beneficial for lower limb amputees.MethodsFour unilateral transtibial and four unilateral transfemoral amputees participated in the study. Each of the subjects wore five different microprocessor-controlled prosthetic feet in addition to their everyday feet. The subjects were asked to stand on slopes of different inclinations (level ground, upward slope of 10°, and downward slope of −10°). Vertical ground reaction forces, joint torques and joint angles in the sagittal plane were measured for both legs separately for the different situations and compared to a non-amputee reference group.ResultsDifferences in the biomechanical parameters were observed between the different prosthetic feet and compared to the reference group for the investigated situations. They were most prominent while standing on a downward slope. For example, on the prosthetic side, the vertical ground reaction force is reduced by about 20%, and the torque about the knee acts to flex the joint for feet that are not capable of a full adaptation to the downward slope. In contrast, fully adaptable feet with an auto-adaptive dorsiflexion stop show no changes in vertical ground reaction forces and knee extending torques.ConclusionsA prosthetic foot that provides both, an auto-adaptive dorsiflexion stop and a sufficient range of motion for fully adapting to inclinations appears to be the key element in the prosthetic fitting for standing on inclinations in lower limb amputees. In such situations, this prosthetic concept appears superior to both, conventional feet with passive structures as well as feet that solely provide a sufficient range of motion. The results also indicate that both, transfemoral and transtibial amputees benefit from such a foot.

Relationships of relative humidity with PM2.5 and PM10 in the Yangtze River Delta, China.

Severe particulate matter (PM, including PM2.5 and PM10) pollution frequently impacts many cities in the Yangtze River Delta (YRD) in China, which has aroused growing concern. In this study, we examined the associations between relative humidity (RH) and PM pollution using the equal step-size statistical method. Our results revealed that RH had an inverted U-shaped relationship with PM2.5 concentrations (peaking at RH=45-70%), and an inverted V-shaped relationship (peaking at RH=40±5%) with PM10, SO2, and NO2. The trends of polluted-day number significantly changed at RH=70%. The very-dry (RH <45%), dry (RH=45-60%) and low-humidity (RH=60-70%) conditions positively affected PM2.5 and exerted an accumulation effect, while the mid-humidity (RH=70-80%), high-humidity (RH=80-90%), and extreme-humidity (RH=90-100%) conditions played a significant role in reducing particle concentrations. For PM10, the accumulation and reduction effects of RH were split at RH=45%. Moreover, an upward slope in the PM2.5/PM10 ratio indicated that the accumulation effects from increasing RH were more intense on PM2.5 than on PM10, while the opposite was noticed for the reduction effects. Secondary transformations from SO2 and NO2 to sulfate and nitrate were mainly responsible for PM2.5 pollution, and thus, controlling these precursors is effective in mitigating the PM pollution in the YRD, especially during winter. The conclusions in this study will be helpful for regional air-quality management.

Replication and Substitution of Anatomic Stabilizing Mechanisms in a Total Knee Design

While the majority of the total knees used today are of the cruciate retaining (CR) and cruciate substituting (PS) types, the results are not ideal in terms of satisfaction, function, and biomechanical parameters. It is proposed that a design which specifically substituted for the structures which provided stability could produce normal laxity behavior, which may be a path forward to improved outcomes. Stabilizing structures of the anatomic knee were identified under conditions of low and high axial loading. The upward slope of the anterior medial tibial plateau and the anterior cruciate was particularly important under all loading conditions. A guided motion design was formulated based on this data, and then tested in a simulating machine which performed an enhanced ASTM constraint test to determine stability and laxity. The guided motion design showed much closer neutral path of motion and laxity in anterior–posterior (AP) and internal–external rotation, compared with the PS design. Particular features included absence of paradoxical anterior sliding in early flexion, and lateral rollback in higher flexion. A total knee design which replicated the stabilizing structures of the anatomical knee is likely to provide more anatomical motion and may result in improved clinical outcomes.