Correlations Between the Thermosphere's Semiannual Density Variations and Infrared Emissions Measured With the SABER Instrument.

This paper presents measurements of the amplitudes and timings of the combined, annual, and semiannual variations of thermospheric neutral density, and a comparison of these density variations with measurements of the infrared emissions from carbon dioxide and nitric oxide in the thermosphere. The density values were obtained from measurements of the atmospheric drag experienced by the Challenging Minisatellite Payload, Gravity Recovery and Climate Experiment A, Gravity field and Ocean Circulation Explorer, and three Swarm satellites, while the optical emissions were measured with the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite. These data span a time period of 16 years. A database containing global average densities that were derived from the orbits of about 5,000 objects (Emmert, 2009, https://doi.org/10.1029/2009JA014102, 2015b, https://doi.org/10.1002/2015JA021047) was employed for calibrating these density data. A comparison with the NRLMSISE-00 model was used to derive measurements of how much the density changes over time due to these seasonal variations. It is found that the seasonal density oscillations have significant variations in amplitude and timing. In order to test the practicality of using optical emissions as a monitoring tool, the SABER data were fit to the measured variations. Even the most simple fit that used only filtered carbon dioxide emissions had good correlations with the measured oscillations. However, the density oscillations were also well predicted by a simple Fourier series, contrary to original expectations. Nevertheless, measurements of the optical emissions from the thermosphere are expected to have a role in future understanding and prediction of the semiannual variations.

Quantitative maps of geomagnetic perturbation vectors during substorm onset and recovery.

We have produced the first series of spherical harmonic, numerical maps of the time-dependent surface perturbations in the Earth's magnetic field following the onset of substorms. Data from 124 ground magnetometer stations in the Northern Hemisphere at geomagnetic latitudes above 33° were used. Ground station data averaged over 5 min intervals covering 8 years (1998-2005) were used to construct pseudo auroral upper, auroral lower, and auroral electrojet (AU*, AL*, and AE*) indices. These indices were used to generate a list of substorms that extended from 1998 to 2005, through a combination of automated processing and visual checks. Events were sorted by interplanetary magnetic field (IMF) orientation (at the Advanced Composition Explorer (ACE) satellite), dipole tilt angle, and substorm magnitude. Within each category, the events were aligned on substorm onset. A spherical cap harmonic analysis was used to obtain a least error fit of the substorm disturbance patterns at 5 min intervals up to 90 min after onset. The fits obtained at onset time were subtracted from all subsequent fits, for each group of substorm events. Maps of the three vector components of the averaged magnetic perturbations were constructed to show the effects of substorm currents. These maps are produced for several specific ranges of values for the peak |AL*| index, IMF orientation, and dipole tilt angle. We demonstrate an influence of the dipole tilt angle on the response to substorms. Our results indicate that there are downward currents poleward and upward currents just equatorward of the peak in the substorms' westward electrojet. KEY POINTS: Show quantitative maps of ground geomagnetic perturbations due to substorms Three vector components mapped as function of time during onset and recovery Compare/contrast results for different tilt angle and sign of IMF Y-component.

High correlations between temperature and nitric oxide in the thermosphere.

Obtaining accurate predictions of the neutral density in the thermosphere has been a long-standing problem. During geomagnetic storms the auroral heating in the polar ionospheres quickly raises the temperature of the thermosphere, resulting in higher neutral densities that exert a greater drag force on objects in low Earth orbit. Rapid increases and decreases in the temperature and density may occur within a couple days. A key parameter in the thermosphere is the total amount of nitric oxide (NO). The production of NO is accelerated by the auroral heating, and since NO is an efficient radiator of thermal energy, higher concentrations of this molecule accelerate the rate at which the thermosphere cools. This paper describes an improved technique that calculates changes in the global temperature of the thermosphere. Starting from an empirical model of the Poynting flux into the ionosphere, a set of differential equations derives the minimum, global value of the exospheric temperature, which can be used in a neutral density model to calculate the global values. The relative variations in NO content are used to obtain more accurate cooling rates. Comparisons with the global rate of NO emissions that are measured with the Sounding of the Atmosphere using Broadband Emission Radiometry instrument show that there is very good agreement with the predicted values. The NO emissions correlate highly with the total auroral heating that has been integrated over time. We also show that the NO emissions are highly correlated with thermospheric temperature, as well as indices of solar extreme ultraviolet radiation.

Relationship between sympathetic reactivity and body weight loss in morbidly obese subjects.

OBJECTIVE: To investigate the possible role of peripheral sympathetic activity in gastric bypass-induced body weight loss. SUBJECTS AND METHODS: In 42 morbidly obese patients (sex: 36 f/6 m; BMI: 46.0+/-0.7 kg/m(2)) undergoing a gastric bypass, the skin vasoconstrictor reflex in answer to a deep inspiration was measured by laser Doppler fluximetry. The extent of vasoconstriction, measured at the second finger of the left hand, was expressed as percent reduction of the basal blood flux (% vasoconstriction). Insulin sensitivity was assessed before surgery in a subset of patients (n=11), by the method of euglycemic, hyperinsulinemic clamp. Body weight and composition were evaluated before, and 3, 6 and 12 months after surgery. At the same time points, energy intake (kJ/day) was evaluated by means of both food record diary and alimentary anamnesis. RESULTS: The % vasoconstriction, which was significantly (P=0.01) greater in normoglycemic subjects than in diabetic ones, was also significantly (P=0.03) related to the extent of insulin sensitivity measured during the euglycemic clamp. The % vasoconstriction showed a significant (P>0.0001), positive correlation with weight reduction obtained between the 6th and 12th months following surgery; as a consequence, % vasoconstriction was significantly (P=0.0004) related to the overall body weight loss achieved during the year following the operation. These correlations remained significant in multiple regression analysis with adjustment for age, initial body weight, plasma glucose and insulin (P=0.0007 and 0.006, respectively). The % vasoconstriction was also significantly (P=0.0006), negatively related to energy intake measured 12 months after surgery. CONCLUSIONS: In conditions of stable body weight, the sympathetic nervous system (SNS) reactivity is influenced by the degree of insulin resistance. A high capacity to activate the SNS, measured before surgery, is associated with both a larger gastric bypass-induced weight loss and a lower energy intake, at the phase of weight stabilization.

Selected Contribution: Osteocytes upregulate HIF-1alpha in response to acute disuse and oxygen deprivation.

Loss of mechanical loading, or disuse, rapidly precipitates locally mediated bone resorption. However, the pathway by which this process is initiated and mediated is poorly understood. In this study, we used a complementary in vivo and in vitro approach to determine whether disuse-induced osteocyte hypoxia resulted in upregulation of the hypoxia-dependent transcription factor HIF-1alpha. We found that acute disuse (1-5 days) resulted in a significant increase in the percentage of osteocytes staining positive for HIF-1alpha vs. normal bone (30.9 +/- 6.1 vs. 14.1 +/- 3.8%) and that this response was uniform around the cortex. In addition, we found that acute oxygen deprivation (4-12 h of 2% O2) resulted in a 2.1- to 3.7-fold upregulation of HIF-1alpha protein expression in MLO-Y4 osteocyte-like cells compared with cells cultured in parallel under normal oxygen conditions. Given known HIF-1alpha targets genes, we suggest that osteocyte hypoxia and subsequent upregulation of hypoxia-dependent pathways may serve to initiate and mediate disuse-induced bone resorption.

Cyclosporine toxicity in renal transplant recipients detected by nailfold capillaroscopy with Na-fluorescein.

BACKGROUND: Cyclosporine represented a major advance in the medical management of patients with organ transplantation, but its use is limited by the frequent occurrence of hypertension and renal toxicity diagnosed by invasive renal biopsy. Renal histology shows a specific arteriolopathy. It was hypothesized that cyclosporine may also induce subclinical microvascular changes in the skin that might be detected noninvasively by a combination of dynamic capillaroscopy [capillary blood cell velocity (CBV)] with and without intravenous Na-fluorescein (NaF) injection and laser Doppler fluxmetry (LDF). METHODS: The nailfold skin microcirculation was evaluated in 112 consecutive renal transplant recipients (54 +/- 11 years old; 70 males and 42 females) receiving cyclosporine. The investigation was made the same day as a routine renal biopsy performed in all patients more than two years after transplantation. Renal biopsies were blindly classified as positive (N = 33) when significant specific signs of cyclosporine toxicity were clearly observed (AH2-AH3) and were otherwise negative (AH0-AH1, N = 79) according to the Banff classification. RESULTS: Time to fluorescence peak after NaF injection (tpNaF) was significantly longer in patients with positive biopsies than in patients with negative biopsies (13.9 +/- 8.1 vs. 17.5 +/- 9.4 sec, P = 0.009). All patients but three with negative biopsies (93%) had a tpNaF less than 10 seconds (sensitivity 91%, negative predictive value 93%). On the other hand, CBV, LDF, plasma levels of cyclosporine, and endothelin were similar in the two groups. CONCLUSION: Nailfold fluorescence capillaroscopy is an accurate and simple mean to rule out cyclosporine toxicity in renal transplant recipients. A normal test could avoid invasive renal biopsy in about 40% of the patients. Renal biopsy would, however, still be indicated when the test is abnormal.

Racial differences in access to high-quality cardiac surgeons.

OBJECTIVES: Racial differences in access to cardiac artery bypass graft (CABG) surgery are well documented. This study extends the literature by examining racial differences in access to high-quality cardiac surgeons. METHODS: The analyses included 11,296 CABG surgeries in New York State in 1996. Regression techniques were used to identify significant associations between a patient's race, health maintenance organization (HMO) enrollment, and the quality of the surgeon performing the surgery, measured by the surgeon's risk-adjusted mortality rate (RAMR). RESULTS: Non-Whites were more likely than Whites to have access to surgeons of higher RAMR, by 11.7% among HMO enrollees (1-tailed P < .1) and by 5.4% among fee-for-service enrollees (1-tailed P < .05). CONCLUSIONS: Even when racial minorities do gain access to CABG services, they are more likely that non-Whites to receive care from lower-quality providers.

Do quality report cards play a role in HMOs' contracting practices? Evidence from New York State.

OBJECTIVE: To answer two related questions: (1) Do managed care organizations (MCOs) in New York State (NYS) consider quality when they choose cardiac surgeons? (2) Do they use information about risk-adjusted mortality rates (RAMR) provided in the New York State Cardiac Surgery Reports? DATA SOURCES: (1) Telephone interviews with and contracting data from the majority of MCOs licensed in NYS; (2) RAMR, quality outlier designation, and procedure volume for all cardiac surgeons, as reported in the Cardiac Surgery Reports. STUDY DESIGN: Interview data were analyzed in conjunction with patterns revealed by contracting data. Null hypotheses that MCOs' contracting choices were random with respect to the information published in the Cardiac Surgery Reports were tested. PRINCIPAL FINDINGS: Sixty percent of MCOs ranked the quality of surgeons as most important in their contracting considerations. Although 64 percent of MCOs indicated some knowledge of the NYS Cardiac Surgery Reports, only 20 percent indicated that the reports were a major factor in their contracting decision. Analyses of actual contracting patterns show that in aggregate, the hypothesis of random choice could be rejected with respect to high-quality outlier status and high procedure volume but not for RAMR or poor-quality outlier status. The panel composition of the majority of MCOs (80.2 percent) was within two standard deviations of the expected mean under the null hypothesis. CONCLUSIONS: Despite a professed preference for high-quality surgeons, the use of publicly available quality reports by MCOs is currently low, and contracting practices for the majority of MCOs do not indicate a systematic selection either for or against surgeons based on their reported mortality scores. This study suggests that policy initiatives to increase the effective use of report cards should be encouraged.

[Mild cognitive deficit in the elderly. Results of a gerontologic study]. / Leichte kognitive Beeinträchtigung im Alter. Ergebnisse einer gerontologischen Untersuchung.

The term "mild cognitive impairment" refers to cognitive deficits which exceed normal physiological aging processes, but do not fulfill the criteria for dementia. The prevalence rates of four current concepts were compared in a sample of 202 healthy 60-64 year-old participants recruited from the interdisciplinary longitudinal study on adult development and aging (ILSE). Furthermore, the relationships between cognitive deficits and psychological and sociodemographic variables were examined. The following prevalence rates were determined: 13.5% for age-associated memory impairment, 6.5% for age-consistent memory impairment, 1.5% for late-life forgetfulness and 23.5% for aging-associated cognitive decline. Subjective cognitive complaints did not correlate with results obtained from neuropsychological tests. Significant correlations were however found between subjective cognitive complaints and higher scores on depression and neuroticism scales. Significant correlations were also found between a reduced test performance and a lower educational level and socioeconomic status. Longitudinal studies are warranted to further elucidate the predictive value of these diagnostic concepts.

Effects of intermittent pneumatic compression on venous haemodynamics and fibrinolytic activity.

Pneumatic intermittent compression is an effective method to prevent postoperative venous thromboembolism. Its efficacy has been ascribed to both a haemodynamic action (increase of blood flow velocity) and a stimulation of endogenous fibrinolytic activity [via the production of tissue-type plasminogen activator (t-PA) by the vascular endothelium]. The relative contribution of these two effects is still debated. In a randomized, cross-over study in ten healthy volunteers, we compared the haemodynamic and fibrinolytic effects of two different pneumatic intermittent compression devices: a classical, low-pressure, whole-leg boots system, and a novel, high-pressure, plantar compression system. The study was performed at rest, to compare haemodynamics and fibrinolytic activity modifications, and under induced venous leg stasis, in order to compare the two compression systems in experimental conditions mimicking laparoscopic surgery. Our data show that (1) a pneumatic compression device that exerts its compression on the plantar venous plexus only induced an increase of venous blood peak velocity and flow in the common femoral vein that is very similar to that induced by the classical whole-leg boots compression system; (2) the venous stasis induced by an external pressure mimicking the conditions of laparoscopic surgery further increased the absolute velocity and flow increase, with the two intermittent compression systems tested; (3) no changes of t-PA or plasminogen activator-inhibitor 1 antigens were observed with either pneumatic compression device. In conclusion, the present study indicates that the antithrombotic effect of mechanical prophylaxis is probably mainly due to its ability to increase venous peak velocity and flow, especially under venous stasis conditions.

A method of evaluating efficiency in the operating room.

A scientific four-step approach to evaluating efficiency in the operating room (OR) is described. These steps include identification of sequential work activities (SWAs) that are critical to the timely progression of surgical cases through the OR, identification of a time standard for completion of SWAs, direct observations of the amount of time required for completion of SWAs, and analysis of results. Two strategies to improve OR efficiency are described. Intergroup strategies require coordination of work among various specialty groups involved with the progress of cases through the OR. Interpersonal strategies necessitate coordination of work between two or more people within the same specialty group.

Changes in estrogen and progesterone receptor content of primary breast carcinoma during the menstrual cycle.

This study was undertaken to determine if hormone receptor activity in breast cancers changes during different phases of the menstrual cycle. Estrogen (ER) and progesterone (PgR) receptors in seventy-eight primary breast carcinomas from premenopausal women were compared with the phase of the menstrual cycle at the time of biopsy. The frequency of ER positivity did not change, but PgR positivity became significantly higher after the early follicular phase. An increase in mean ER and PgR concentration was found (p less than .05) in the late luteal phase. The results indicate that tumor ER and PgR values change during the menstrual cycle, probably in response to endogenous hormonal fluctuations, and this may account for some vicissitudes in establishing hormone dependence.