BACKGROUND The present study explored the role of closing volume as a determinant of orthopnea in stable obese subjects. We hypothesized that: (1) increase in closing volume in supine position would be greater in orthopneic than in non-orthopneic subjects, and (2) the relationship of change in closing volume to change in dyspnea with position would be dependent on expiratory flow limitation in ...

In renal clinical trials, both slope-based and time-to-event renal outcomes have been used. These outcomes are typically based on estimates of GFR obtained using creatinine or iothalamate GFR (iGFR). The African American Study of Kidney Disease and Hypertension (AASK) was a trial in 1094 African Americans with hypertensive nephrosclerosis, which examined the effects of two levels of BP control ...

BACKGROUND Immunoassay-based screening for amphetamines has a variable positive predictive value (PPV) for detecting amphetamine abuse. The lack of immunoassay specificity necessitates confirmatory testing by gas chromatography-mass spectrometry (GC/MS), but the technical complexity and expense of GC/MS limit its availability. Physicians may make decisions regarding patient disposition based on...

The failure of oxygen uptake to increase with increasing work has been considered a marker of the limits of the cardiopulmonary system for many years. However, the concept has suffered from inconsistencies in definition, criteria, and data sampling, all of which affect the interpretation of the relation between changes in work and oxygen uptake. To evaluate the response and reproducibility of t...

OBJECTIVES The aim of this study was to test the hypothesis that the noninvasively constructed slope of the relationship between left ventricular (LV) regional systolic strain and stretch during atrial contraction represents LV inotropic state. BACKGROUND LV systolic response to a changing preload depends on its inotropic state. Changing the preload has allowed constructing the slope of the e...

Biological macromolecules expand with increasing temperature and this dynamic expansion is associated with the onset of function. The expansion is typically characterized by the mean square vibrational displacement (MSD), 〈u〉, of specific atoms such as hydrogen within the macromolecules. We show that the observed expansion and change in slope of 〈u〉 with temperature at a dynamical transition te...

Although handwriting can vary in size, it remains remarkably similar in form, demonstrating motor constancy (equivalence). A consideration of changes in writing size may indicate: (1) how rescaling is accomplished, and (2) those invariant features that remain constrained under size variation. In the experiment reported here nine participants wrote the word "minimum" (without dotting "i's") in c...

We examined the length changes and electromyographic (EMG) activity of two hindlimb muscles in wild turkeys, to determine how these muscles modulate mechanical function with changes in running speed and slope. The muscles studied were the iliotibialis lateralis pars postacetabularis (ILPO), a biarticular knee and hip extensor, and the femorotibialis lateralis (FT), a knee extensor. Muscle lengt...

urban settlements and their connectivity will be the dominant driver of global change during the twenty-first century. in an attempt to assess the effects of urban growth on available land for other uses and its associated impacts on environmental parameters, we modeled the change in the extent of gorgan city, the capital of the golestan province of iran. we used landsat tm and etm+ imagery of ...