New tropical seed oils. II.—Component acids of leguminous and other seed oils

The component acids of seed oils from over fifty legumes and over fifty other species are reported, and their potential value is discussed.     

Phase noise characteristics of a diode-pumped Nd:YAG laser in an unbalanced fiber-optic interferometer

The measurement sensitivity of interferometric fiber sensors can be limited by the laser phase noise. We investigate the phase noise characteristics of a diode-pumped Nd:YAG laser in an unbalanced fiber-optic interferometer. Measurements were made of the phase-induced intensity noise of an interferometer with varying optical path differences. The experimental results of the relation between the noise and the optical path difference are given, and the application of the results in the design of a fiber-optic accelerometer is discussed.     

Collaboration and Teamwork: Immersion and Presence in an Online Learning Environment

In the world of OTIS, an online Internet School for occupational therapists, students from four European countries were encouraged to work collaboratively through problem-based learning by interacting with each other in a virtual semi-immersive environment. This paper describes, often in their own words, the experience of European occupational therapy students working together across national and cultural boundaries. Collaboration and teamwork were facilitated exclusively through an online environment, since the students never met each other physically during the OTIS pilot course. The aim of the paper is to explore the observations that (1) there was little interaction between students from different tutorial groups and (2) virtual teamwork developed in each of the cross-cultural tutorial groups. Synchronous data from the students was captured during tutorial sessions and peer-booked meetings and analyzed using the qualitative constructs of immersion, presence and reflection in learning. The findings indicate that immersion was experienced only to a certain extent. However, students found both presence and shared presence, within their tutorial groups, to help collaboration and teamwork. Other evidence suggests that communities of interest were established. Further study is proposed to support group work in an online learning environment. It is possible to conclude that collaborative systems can be designed, which encourage students to build trust and teamwork in a cross cultural online learning environment.This revised version was published online in March 2005 with corrections to the cover dateFunded by the European Union through the TENTelecom programme.     

Online Teaching: Encouraging Collaboration through Anonymity

The essay comprises four sections. The first section provides a survey of some significant developments which today determine philosophical discussion on the subject of 'time'. The second section conisders the question of how time and the issue of media are linked with one another in the views of two influential contemporary philosophers – Jacques Derrida and Richard Rorty. Finally, in the third section, the temporal implications of cultural practices developing in the new medium of the Internet are analyzed and, in the fourth section, related to the named philosophers' theses.     

Secondary debris impact damage and environment study

All long-duration spacecraft, such as Space Station Freedom (SSF), are subject to impacts by micrometeoroid and orbital debris (MM/OD) particles in low Earth orbit. The secondary effects of such impacts on SSF was the subject of the Secondary Debris Impact Damage and Environment Study. The primary objective was the assessment of possible damage to SSF hardware in the vicinity of large surface areas impacted by typical MM/OD particles. Several SSF components were evaluated that showed varying degrees of damage due to secondary ejecta. A comparison of the results from 45° and 60° MM/OD impacts revealed that penetration ejecta had greater damage potential at 45° and ricochet ejecta had greater damage potential at 60°. The significant ricochet damage was concentrated within an angle of 15° with respect to the primary target. The impact distribution data was evaluated further using a previous math model. The comparison was inconclusive due to insufficient data within the bounds of the model. Preliminary results of the study showed that secondary debris has the potential to penetrate and induce some damage to SSF hardware. The failure of hardware due to the damage is unknown. Further testing with larger MM/OD particle sizes and varying impact angles is recommended.     

Viability of an enzymatic mannitol method to predict sugarcane deterioration at factories

The delivery of consignments of deteriorated sugarcane to factories can detrimentally affect multiple process units, and even lead to a factory shut-down. An enzymatic factory method was used to measure mannitol, a major degradation product of sugarcane Leuconostoc deterioration in the US, in press (consignment) and crusher juices collected across the 2004 processing season at a Louisiana factory. Weather conditions varied markedly across the season causing periods of the delivery of deteriorated sugarcane to the factory. A strong polynomial relationship existed between mannitol and haze dextran (R² = 0.912) in press and crusher juices. Mannitol concentrations were usually higher than haze and monoclonal antibody dextran concentrations, which indicates: (i) the usefulness and higher sensitivity of mannitol to better predict sugarcane deterioration from Leuconostoc and other bacteria than dextran, and (ii) the underestimation by sugar industry personnel of the relatively large amounts of mannitol present in deteriorated sugarcane that can affect processing. Greater than ∼2500 ppm/%Brix mannitol in juice predicts downstream processing problems. The enzymatic method is quantitative and could be used in a sugarcane payment formula. Approximately >300 ppm/%Brix haze dextran in raw sugar indicated that the majority of the crystals were elongated. Approximately >600 ppm/%Brix antibody dextran indicated when elongated crystals were predominant in the raw sugar. The enzymatic mannitol method underestimates mannitol in raw sugars.     

Lamin-Related Congenital Muscular Dystrophy Alters Mechanical Signaling and Skeletal Muscle Growth

Laminopathies are a clinically heterogeneous group of disorders caused by mutations in the LMNA gene, which encodes the nuclear envelope proteins lamins A and C. The most frequent diseases associated with LMNA mutations are characterized by skeletal and cardiac involvement, and include autosomal dominant Emery–Dreifuss muscular dystrophy (EDMD), limb-girdle muscular dystrophy type 1B, and LMNA-related congenital muscular dystrophy (LMNA-CMD). Although the exact pathophysiological mechanisms responsible for LMNA-CMD are not yet understood, severe contracture and muscle atrophy suggest that mutations may impair skeletal muscle growth. Using human muscle stem cells (MuSCs) carrying LMNA-CMD mutations, we observe impaired myogenic fusion with disorganized cadherin/β catenin adhesion complexes. We show that skeletal muscle from Lmna-CMD mice is unable to hypertrophy in response to functional overload, due to defective fusion of activated MuSCs, defective protein synthesis and defective remodeling of the neuromuscular junction. Moreover, stretched myotubes and overloaded muscle fibers with LMNA-CMD mutations display aberrant mechanical regulation of the yes-associated protein (YAP). We also observe defects in MuSC activation and YAP signaling in muscle biopsies from LMNA-CMD patients. These phenotypes are not recapitulated in closely related but less severe EDMD models. In conclusion, combining studies in vitro, in vivo, and patient samples, we find that LMNA-CMD mutations interfere with mechanosignaling pathways in skeletal muscle, implicating A-type lamins in the regulation of skeletal muscle growth.     

Evaluating the use of digital image correlation for strain measurement in historic tapestries using representative deformation fields

An analysis technique to assess the viability of digital image correlation (DIC) in tracking the full‐field strains across the surface of hanging historic tapestries is presented. Measurement uncertainty related to the use of the inherent tapestry image in tracking displacements is investigated through use of “synthetic” deformation fields. The latter are generated by mapping the details of a given tapestry image into finite element analyses. The combination of self‐weight loading, material non‐linearity, and image specific heterogeneity (related to slit stitching, damage, and patch‐restorations) serve to generate a bespoke deformation field complex enough to assess the reliability of DIC measurements. Accuracy is evaluated by comparing measured results with the original known deformations. The technique demonstrates that the optimum imaging settings and the choice of subset size for DIC analysis are strongly influenced by the tapestry image and the goal of the measurement, they are found using a compromise between conflicting objectives: minimising measurement error while maximising resolution.