Pressure-viscosity measurements for several lubricants to 5.5 x 10 to the 8th power Newtons per square meter (8 x 10 to the 4th psi) and 149 C (300 F)

A capillary viscometer was used to measure viscosity as a function of pressure, temperature, and shear stress for a number of lubricants. The conditions under which the measurements were made are specified. The results obtained for each material are analyzed. It was determined that all pressure-viscosity coefficients decreased with increasing temperature. Data from other techniques such as optical elastohydrodynamics, oscillating crystal, and low shear capillary viscometry were compared with the results obtained

Thermal Adaptation and Diversity in Tropical Ecosystems: Evidence from Cicadas (Hemiptera, Cicadidae)

The latitudinal gradient in species diversity is a central problem in ecology. Expeditions covering approximately 16°54′ of longitude and 21°4′ of latitude and eight Argentine phytogeographic regions provided thermal adaptation data for 64 species of cicadas. We test whether species diversity relates to the diversity of thermal environments within a habitat. There are general patterns of the thermal response values decreasing in cooler floristic provinces and decreasing maximum potential temperature within a habitat except in tropical forest ecosystems. Vertical stratification of the plant communities leads to stratification in species using specific layers of the habitat. There is a decrease in thermal tolerances in species from the understory communities in comparison to middle level or canopy fauna. The understory Herrera umbraphila Sanborn & Heath is the first diurnally active cicada identified as a thermoconforming species. The body temperature for activity in H. umbraphila is less than and significantly different from active body temperatures of all other studied species regardless of habitat affiliation. These data suggest that variability in thermal niches within the heterogeneous plant community of the tropical forest environments permits species diversification as species adapt their physiology to function more efficiently at temperatures different from their potential competitors

Effects of Hypovolemia on Cerebral Blood Velocity and Autoregulation During Upright Tilt: Implications for Post-Spaceflight Orthostasis

Orthostatic stability depends on maintenance of adequate cerebral blood flow. Orthostatic instability experienced by returning astronauts is associated with microgravity-induced hypovolemia, suggesting that hypovolemia may disrupt the ability of the cerebral vasculature to regulate blood flow. PURPOSE: To test the hypothesis that hypovolemia reduces cerebral blood velocity and impairs cerebral autoregulation (CA) during upright tilt. METHODS: Nine males (age 23 ± .5 yrs; height 172 ± 2 cm; weight 87 ± 3 kg; mean ± SE) were tilted head-up to 70° on two occasions separated by at least 5 days under euhydration (EUH) and dehydration (DEH) conditions. Dehydration was induced with 40 mg Furosemide and 8 h water restriction. Plasma volumes (PV) and blood volumes (BV) were estimated from venous hemoglobin and hematocrit. ECG, beat-by-beat finger arterial pressures, and cerebral blood velocity (CBV) were measured during a five min supine baseline, and during the first (T1) and last (T2) five min of upright tilt. Dynamic CA was assessed in the frequency domain with cross-spectral analysis of mean arterial pressure (MAP) and mean CBV within the frequency range of 0.07-0.2 Hz. RESULTS: Furosemide reduced PV by 10 ± 2 % and BV by 6 ± 2 % (P = .005 and P = .07). MAP decreased during tilt (P \u3c .007), but the reduction was similar between hydration conditions. CBV during DEH was lower during the entire 10-min tilt by about 7 cm/s (P \u3c .004) compared with EUH. Low frequency coherence was higher during DEH T1 compared with EUH T1 (.67 ± .04 vs .51 ± .04; P = .02), but coherence decreased as tilt continued, and was similar to EUH during T2 (P = 0.7). CONCLUSIONS: Increased coherence during the first 5 min of tilt suggests that reductions of CBV with hypovolemia might be explained by a reduced autoregulatory capacity. However, maintenance of lower CBV despite reduced coherence during the second 5 min of tilt suggests that disruptions of autoregulatory capacity with hypovolemia are transient. Our results provide evidence that hypovolemic astronauts may be at greatest risk for orthostatic intolerance immediately upon assumption of upright posture

Association of Leptin Gene Markers with Carcass Traits in Beef Cattle

The objective of this study was to evaluate four genetic markers on the leptin gene for association with carcass traits in three crossbred families. Three half-sib families were developed from crossbred sires. Families 1, 2, and 3 comprised 26, 21, and 66 offspring, respectively (n = 113). The genetic background of the sires, dams, and offspring was 1/3 Angus, 1/3 Hereford, 1/3 Simmental. Carcass traits collected were finished weight, hot carcass weight (HCW), marbling score, Quality Grade, Longissimus muscle area (LMA), rib fat, Yield Grade, and percent kidney, pelvic, and heart fat (KPH). The four markers analyzed were located on the exon 2, exon 3, and promoter region of the leptin gene. There was an association of marbling score with leptin exon 3 (P \u3c 0.05), and ability to grade choice with leptin exon 2 (P \u3c 0.05), exon 3 (P \u3c 0.001), and promoter (P \u3c 0.01) in family 2. Family 2 also displayed allelic effects for ability to grade choice (P \u3c 0.01) with leptin exon 3 and promoter. Family 3 showed an association between leptin exon 2 (P \u3c 0.05) and marbling score. No association was detected (P \u3e 0.05) on family 1

Ovarian Hormones and Cerebral Hemodynamics During Upright Tilt

The cerebral vasculature is a specific target for ovarian hormones. Estrogens in particular activate endothelial factors that decrease vessel tone and increase blood flow. Changes in cerebral blood flow across the menstrual cycle could underlie the observation that women experience orthostatic instability more often than men, but the influence of ovarian hormone levels on cerebral hemodynamics in the upright posture is unclear. PURPOSE: To test the hypothesis that cerebral blood velocity and cerebral autoregulatory capacity change in parallel with ovarian hormone concentrations. METHODS: Nine healthy eumenorrheic women (mean age 24 ± 1 yr, height 166 ± 3 cm, weight 68 ± 2 kg; mean ± SE) were studied during the early and late follicular (EF and LF) and early and late luteal (EL and LL) phases of the menstrual cycle. We recorded the ECG, beat-by-beat arterial pressure, end-tidal CO2, and cerebral blood velocity from the middle cerebral artery (transcranial Doppler). Plasma ovarian hormone concentrations were assessed with high performance liquid chromatography. Subjects breathed in time to a metronome for 10 min (15 breaths/min) in the supine position, and were then tilted head-up to 70° for an additional 10 min of controlled breathing. Cerebral autoregulation was assessed in the frequency domain with cross-spectral analysis of mean arterial pressure (MAP) and mean CBV within the frequency range of 0.07-0.2 Hz. RESULTS: Upright tilt decreased CBV (supine 74 ± 1.7; tilt 65 ± 1.8 cm ∙ s-1; P=.005 pooled across phases) and end-tidal CO2 (P\u3c.001) but did not affect MAP. Coherence increased from .45 ± .02 to .67 ± .03 with tilt (P\u3c .001 pooled across phases) and was significantly higher during LF (.61 ± .03) compared with LL (.48 ± .03; P = .04). Lower coherence during LL compared with LF was associated with higher concentrations of progesterone (P \u3c .001). CONCLUSIONS: Upright tilt decreases CBV, and the magnitude of reduction is not related to ovarian hormone concentrations. Lower coherence during LL compared with LF suggests improved autoregulatory capacity mediated by higher concentrations of progesterone. These results have implications for orthostatic stability in women

Investigations of lubricant rheology as applied to elastohydrodynamic lubrication

Traction prediction in sliding elastohydrodynamic (EHD) contacts was examined along with an elastohydrodynamic lubrication simulation of the effects of load and speed on temperatures in the EHD contact. An existing shear stress theory and lubricant rheological model were studied and evaluated by applying them to traction prediction. Results obtained using measured film thickness and surface temperature data, were compared with measured traction values. The infrared technique for measuring temperatures in an EHD contact was further developed and ball surface and fluid temperatures are reported for sliding speeds of 0.35 to 5.08 m/s at 0.52 to 2.03 GN/sq m maximum pressure and surface roughnesses of .011 to .381 micrometers c.1.a. The relationship between asperity interaction, as measured by relocation surface profilimetry and high frequency temperature measurements, and the ratio of film thickness to surface roughness was also studied

Results of Lung Cancer Screening in the Community.

PURPOSE: To address doubts regarding National Lung Screening Trial (NLST) generalizability, we analyzed over 6,000 lung cancer screenings (LCSs) within a community health system. METHODS: Our LCS program included 10 sites, 7 hospitals (2 non-university tertiary care, 5 community) and 3 free-standing imaging centers. Primary care clinicians referred patients. Standard criteria determined eligibility. Dedicated radiologists interpreted all LCSs, assigning Lung Imaging Reporting and Data System (Lung-RADS) categories. All category 4 Lung-RADS scans underwent multidisciplinary review and management recommendations. Data was prospectively collected from November 2013 through December 2018 and retrospectively analyzed. RESULTS: Of 4,666 referrals, 1,264 individuals were excluded or declined, and 3,402 individuals underwent initial LCS. Second through eighth LCSs were performed on 2,758 patients, for a total of 6,161 LCSs. Intervention rate after LCS was 14.6% (500 individuals) and was most often additional imaging. Invasive interventions (n = 226) were performed, including 141 diagnostic procedures and 85 surgeries in 176 individuals (procedure rate 6.6%). Ninety-five lung cancers were diagnosed: 84 non-small cell (stage 1: 60; stage 2: 7; stage 3: 9; stage 4: 8), and 11 small cell lung cancers. The procedural adverse event rate was 23/226 (10.1%) in 21 patients (0.6% of all screened individuals). Pneumothorax (n = 10) was the most frequent, 6 requiring pleural drainage. There were 2 deaths among 85 surgeries or 2.3% surgical mortality. CONCLUSIONS: Our LCS experience in a community setting demonstrated lung cancer diagnosis, stage shift, intervention frequency, and adverse event rate similar to the NLST. This study confirms that LCS can be performed successfully, safely, and with equivalence to the NLST in a community health care setting

Reply to Rouder (2014) : good frequentist properties raise confidence

Established psychological results have been called into question by demonstrations that statistical significance is easy to achieve, even in the absence of an effect. One often-warned-against practice, choosing when to stop the experiment on the basis of the results, is guaranteed to produce significant results. In response to these demonstrations, Bayes factors have been proposed as an antidote to this practice, because they are invariant with respect to how an experiment was stopped. Should researchers only care about the resulting Bayes factor, without concern for how it was produced? Yu, Sprenger, Thomas, and Dougherty (2014) and Sanborn and Hills (2014) demonstrated that Bayes factors are sometimes strongly influenced by the stopping rules used. However, Rouder (2014) has provided a compelling demonstration that despite this influence, the evidence supplied by Bayes factors remains correct. Here we address why the ability to influence Bayes factors should still matter to researchers, despite the correctness of the evidence. We argue that good frequentist properties mean that results will more often agree with researchers’ statistical intuitions, and good frequentist properties control the number of studies that will later be refuted. Both help raise confidence in psychological results