The effects of concentration-dependent morphology of self-assembling RADA16 nanoscaffolds on mixed retinal cultures

RADA16 self-assembling peptide nanofiber scaffolds (SAPNSs) have been shown to have positive effects on neural regeneration following injury to the central nervous system in vivo, but mechanisms are unclear. Here we show that RADA16 SAPNSs form scaffolds of increasing fiber density with increasing peptide concentration which in turn has a concentration-dependent effect on neurons and astrocytes in mixed retinal cultures. Importantly, we report that the final nanoscale fiber architecture is an important factor to consider in designing scaffolds to promote regeneration in the central nervous system.     

Herd-level variables associated with premilking stimulation time in Michigan dairy herds

The objective of this study was to determine the herd-level variables that were associated with total stimulation time during the premilking routine in 64 Michigan dairy herds. The mean herd size was 452 cows (range = 59 to 2,771 cows). For each herd, surveys were administered to producers to gather mastitis management practices and attitudes. Additionally, milking protocols were observed and milk flow dynamics were measured by use of digital vacuum recorders. Backward multivariate regression analysis was used to determine which of 47 herd-level milking and management variables were associated with mean total stimulation time. Mean total stimulation time was 14.2 s (range = 2.4–40.8 s) and was positively associated with increasing latency period (time interval between first stimulation and cluster attachment). Total stimulation time was negatively associated with greater herd size and number of visits to each cow in the premilking routine. In summary, increased stimulation time is more likely in herds that foster a lower sense of urgency of cow throughput during milking, as evidenced by a positive association with longer latency periods and fewer preparation visits per cow. Tactile stimulation is critical for efficient milk ejection; if inadequate, cows are at greater risk of delayed milk ejection and bimodal milk flow, which in turn has been associated with teat congestion and reduced milk flow. This study offers insight as to some of the herd factors that may be limiting adequate tactile stimulation.     

Mechanical design of a second generation LHC IR quadrupole

One of the proposed options to increase the LHC luminosity is the replacement of the existing inner triplets at the interaction regions with new low-beta larger aperture quadrupoles operating at the same gradient. Lawrence Berkeley National Laboratory (LBNL) is carrying out preliminary studies of a large-bore Nb/sub 3/Sn quadrupole. The mechanical design presents a support structure based on the use of keys and bladders without self-supporting collars. This technology has been proven effective in several successful common coil Nb/sub 3/Sn dipoles built at LBNL, and it is for the first time applied to a cos(2/spl thetav/) design. In this paper, we present a detailed analysis of the quadrupole mechanical behavior, demonstrating the possibility of delivering, through this method, well-controlled coil pre-compression during assembly, cool-down and excitation. The study has been performed with the finite element program ANSYS.     

UK government activities in support of OSI

The UK Department of Trade and Industry has taken a considerable and active interest in the development of osi standards. It is now undertaking a number of measures to consolidate these developments and establish a critical quantity and quality of OSI products and services. These measures include application studies, demonstrator projects, conformance testing services and the requirement to use OSI in value-added services.     

Automatic solder joint inspection

The task of automating the visual inspection of pin-in-hole solder joints is addressed. Two approaches are explored: statistical pattern recognition and expert systems. An objective dimensionality-reduction method is used to enhance the performance of traditional statistical pattern recognition approaches by decorrelating feature data, generating feature weights, and reducing run-time computations. The expert system uses features in a manner more analogous to the visual clues that a human inspector would rely on for classification. Rules using these cues are developed, and a voting scheme is implemented to accumulate classification evidence incrementally. Both methods compared favorably with human inspector performance     

Clinical investigations of gastro-oesophageal reflux: Part 1

Most people have at some time experienced the symptoms of heartburn associated with gastro-oesophageal reflux. Fortunately, these symptoms are usually short-lived and require no treatment, but in some patients severe and prolonged reflux of gastric juice into the mouth can cause dental erosion. This paper, the first in a two-part series, describes the aetiology of gastro-oesophageal reflux and associated problems that may be encountered.     

Effects of aging and musical experience on the representation of tonal hierarchies.

Two experiments explored the representation of the tonal hierarchy in Western music among older (aged 60 to 80) and younger (aged 15 to 22) musicians and nonmusicians. A probe tone technique was used: 4 notes from the major triad were presented, followed by 1 note chosen from the 12 notes of the chromatic scale. Whereas musicians had a better sense of the tonal hierarchy than nonmusicians, older adults were no worse than younger adults in differentiating the notes according to musical principles. However, older adults were more prone than younger adults to classify the notes by frequency proximity (pitch height) when proximity was made more salient, as were nonmusicians compared with musicians. With notes having ambiguous pitch height, pitch height effects disappeared among older adults but not nonmusicians. Older adults seem to have internalized tonal structure, but they sometimes fail to inhibit less musically relevant information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)