Walking behaviours from the 1965–2003 American Heritage Time Use Study (AHTUS)

Background  

The American Heritage Time Use Study (AHTUS) represents a harmonised historical data file of time use by adults, amalgamating surveys collected in 1965–66, 1975–76, 1985, 1992–94, and 2003. The objectives of time-use studies have ranged from evaluating household and other unpaid production of goods and services, to monitoring of media use, to comparing lifestyles of more and less privileged social groups, or to tracking broad shifts in social behaviour. The purpose of this paper is to describe the process and utility of identifying and compiling data from the AHTUS to describe a range of walking behaviours collected using time-use survey methods over almost 40 years in the USA.     

A New Optical Technique for Evaluating Collective Motility of Ram and Bull Ejaculated Spermatozoa

A new. non-destructive, objective technique for measuring collective motility of highly-concentrated ram and bull semen is described. The principle is based on changes in the reflected light scattered by motile spermatozoa. These changes can be recorded as a continuous analog wave pattern (Reflectospermiogram-RSG) and are correlated to the intensity of the turbulent motility as evaluated subjectively with an ordinary light microscope. Ram spermatozoa have, after ejaculation, a typical motility pattern, i.e., high, stable activity for about 20 min, then a period during which the motility decreases at a constant rate, and finally, a period with a low but rather constant activity. The usefulness of the technique has been demonstrated in various types of experiments.     

Localization of beta-andrenoceptors in the anterior segment of the albino rabbit eye using a fluorescent analog of propranolol.

A fluorescent analog of propranolol, 9-amino-acridin-propranolol (9-AAP), was injected into the carotid arteries of albino rabbits in an attempt to localize β-adrenergic receptors (β-adrenoceptors) in the anterior segment of the eye. 9-AAP fluorescence was noted mainly in the ciliary epithelium, but also in the walls of the episcleral vessels. Only mild fluorescence was noted in the iris sphincter region. It is suggested that these findings are compatible with the distribution of β-receptor sites in the anterior segment of the rabbit eye.     

Premature atherosclerosis in systemic lupus erythematosus

Significant advances have been made in defining the spectrum of clinical manifestations and the prognosis of systemic lupus erythematosus (SLE). With the use of corticosteroids and other immunosuppressive agents as well as better management of complications such as infection, there has been a dramatic improvement in the short-term prognosis of patients who have SLE from less than 50% survival at 5 years to 93% at 5 years and 85% and 10 years. However, many patients who survive early complications of organ failure and sepsis later develop premature coronary artery disease (CAD). In this evidence-based review, the magnitude of the problem of premature atherosclerosis in SLE is defined and evaluation of the strength of association of risk factors determined to date. The authors focus on the emerging role of new modalities for noninvasive assessment of vascular health in patients who have SLE and offer a strategy for screening and management of those at risk of CAD. The article concludes with a discussion on the important questions that remain to be answered and future directions for research.     

Oncogenic K-ras drives cell cycle progression and phenotypic conversion of primary pancreatic duct epithelial cells

We have established a primary pancreatic duct epithelial cell culture (PDEC) system to investigate the relationship between oncogenic activation of K-ras and pancreatic ductal tumorigenesis. We have found that the acute introduction of physiological levels of oncogenic K-ras (K-rasV12) into quiescent PDECs stimulates S-phase entry and induces a pronounced increase in cell size. Both effects are dependent on the functional integrity of the phosphatidylinositol 3'-kinase (PI3K)/mammalian target of rapamycin (mTOR) signaling pathway. In addition, K-rasV12 promotes the loss of epithelial E-cadherin and the gain of mesenchymal N-cadherin in PDEC. Our observations indicate that the oncogenic activation of K-ras is sufficient to elicit mitogenic and morphogenic responses in pancreatic ductal cells and hence is likely to play an instructive role in the initiation of pancreatic ductal adenocarcinoma.     

Neural correlates of auditory repetition priming: reduced fMRI activation in the auditory cortex

Repetition priming refers to enhanced or biased performance with repeatedly presented stimuli. Modality-specific perceptual repetition priming has been demonstrated behaviorally for both visually and auditorily presented stimuli. In functional neuroimaging studies, repetition of visual stimuli has resulted in reduced activation in the visual cortex, as well as in multimodal frontal and temporal regions. The reductions in sensory cortices are thought to reflect plasticity in modality-specific neocortex. Unexpectedly, repetition of auditory stimuli has resulted in reduced activation in multimodal and visual regions, but not in the auditory temporal lobe cortex. This finding puts the coupling of perceptual priming and modality-specific cortical plasticity into question. Here, functional magnetic resonance imaging was used with environmental sounds to reexamine whether auditory priming is associated with reduced activation in the auditory cortex. Participants heard environmental sounds (e.g., animals, machines, musical instruments, etc.) in blocks, alternating between initial and repeated presentations, and decided whether or not each sound was produced by an animal. Repeated versus initial presentations of sounds resulted in repetition priming (faster responses) and reduced activation in the right superior temporal gyrus, bilateral superior temporal sulci, and right inferior prefrontal cortex. The magnitude of behavioral priming correlated positively with reduced activation in these regions. This indicates that priming for environmental sounds is associated with modification of neural activation in modality-specific auditory cortex, as well as in multimodal areas.     

Psoriatic arthritis

Although there is still some controversy about the existence of psoriatic arthritis as a specific form of inflammatory arthritis associated with psoriasis, epidemiological, and clinical studies support the unique features of psoriatic arthritis. Because of lack of diagnostic or classification criteria, the disease has been thought of as uncommon. Over the past several decades, it has become clear that the disease leads to serious disability and even increased mortality. Traditional medications have not been effective in preventing the progression of joint damage. New medications, including biologics, have emerged with the potential to control the inflammation and arrest the progression of joint damage.