An analysis of the correlation between structural anisotropy and dimensional stability for drawn poly(lactic acid) films

The anisotropic structures found in drawn poly(lactic acid) films are strongly correlated to their overall dimensional stability. Several aspects of this relationship can be efficiently characterized by Raman spectroscopy. We determined the degree of orientation in these drawn films by measuring the relative intensity of the polarized and depolarized components and the shift in the relative band positions. The bandwidth and specific band frequency also correlated well with the degree of sample crystallinity. These aspects make the Raman method amenable for the online monitoring of orientation and crystallinity in commercial processes. A molecular understanding of heat setting to reduce film shrinkage is also proposed. Raman data from films that were heat-set while physically constrained suggest that amorphous-phase relaxation does not occur during heat setting. Rather, the level of crystallinity increases substantially, indicating that the cause of low shrinkage in the films was due to crystalline network formation rather than amorphous-phase relaxation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2497–2505, 2001     

Simultaneous pancreatitis and hepatitis associated with trimethoprim-sulfamethoxazole

A 34-yr-old woman developed simultaneous pancreatitis and hepatitis following exposure to trimethoprim-sulfamethoxazole (TMP/SMX). The episode occurred 4 yr after a previous episode of hepatitis associated with TMP/SMX. This patient represents the second case of concurrent TMP/SMX-induced pancreatitis and hepatitis reported in the literature. However, it is the first in which the adverse reaction was documented following an inadvertent rechallenge with the drug.     

Experimental Manufacture of Paper for War Maps

Early in World War II, a new map paper was developed that greatly improved the quality and performance of war maps. The National Bureau of Standards cooperated in the development and, subsequently, determined by experimental manufacture how to make the paper from commercially available raw materials. The best results were obtained in experimental manufacture by using fiber furnishes of 100-percent strong bleached sulfate pulps with the addition of melamine-formaldehyde resin to increase the wet strength and titanium dioxide to produce the desired capacity. It was essential that the beating be very carefully controlled to preserve the maximum fiber strength. The most critical requirements from a manufacturing standpoint were very high resistance to tear, high wet tensile strength, high opacity, and good smoothness. A moderate degree of wildness was not objectionable. The data obtained by experiments were applied to initiate the commercial production of the new paper to meet unprecedented tonnage requirements.     

A machining process planning activity model for systems integration

A key issue of integrating process planning systems with design systems and production planning systems is how to overcome barriers in data exchange and sharing amongst software systems. A machining process planning activity model was developed to address some of the barriers. This model represents functional components and data requirements in process planning systems. The purpose of the model is to create the context in which data requirements and data flow for numerically controlled machining process planning are defined. Furthermore, the model was developed as a unification of many previously developed process planning activity models.     

Migration of primordial germ cells to the developing gonadal ridges in the tammar wallaby Macropus eugenii

Primordial germ cells (PGCs) of the tammar wallaby Macropus eugenii have a distinctive morphology and stain positively for alkaline phosphatase. PGCs are identifiable in embryos with 12 somites, on about day 17 of the 26.5 day gestation period, when they are located in all three germ layers of the developing embryo and in the endoderm of the bilaminar and vascular (trilaminar) yolk sac membranes. PGCs are positive for alkaline phosphatase (ALP) at least between days 17 and 22 of pregnancy. In whole mounts on day 17, three groups of cells positive for ALP occur: about 40 just caudal to the neural tube, and about 20 distributed on either side of the last three somites. By day 21, there are about 150 PGCs in the newly formed gonadal ridges and 275 in the mesenteries. On days 21-22, there are PGCs in the umbilical mesoderm, the dorsal mesentery and the coelomic angles between the dorsal mesentery and the mesonephroi. On day 22, most ALP-positive PGCs are located in the dorsal mesentery, where they occur in groups. They apparently do not migrate through the hindgut endoderm, but occasional PGCs are seen in sites such as the mesonephros, the adrenals, the blood vessels of the yolk sac and in the vicinity of the dorsal aorta and dorsal nerve cord. Between day 23 and day 25, 1 day before birth, most of the 3200-4000 PGCs complete their migration to the gonadal ridges. Although there are marked differences between embryogenesis of tammars and mice, development and the pattern of migration of PGCs in this marsupial mammal are similar to that of eutherian mammals.     

T cell subpopulation phenotypes in filarial infections: CD27 negativity defines a population greatly enriched for Th2 cells

Three-color flow cytometric analysis was used to define surface markers which identify the Th2-type CD4+ cells responsible for the eosinophilia and elevated serum IgE typical of tissue invasive helminth infections. A group of six mAbs to well known cell surface markers were screened for differential expression on CD4+ CD45RO+ lymphocytes from normal individuals (NL; n = 6) and filaria-infected patients (PT; n = 10). The majority of markers were expressed equally by both groups, but the CD4+ CD45RO+ cells in the PTs showed significantly higher levels of expression of HLA-DR than those of NLs (P = 0.014). This CD4+ HLA-DR+ subpopulation was then studied further for its expression of an additional 10 activation and adhesion molecules. CD27 showed a trend for lower intensities of expression on PT CD4+ HLA-DR+ cells than on those of NLs. Analysis of the serum from both NLs and PTs revealed that PTs had significantly higher levels of soluble CD27 and CD25 (IL-2R) in the serum than NLs (P < 0.01 and P = 0.022 respectively) indicating a general state of immune activation and differentiation. Functional analysis of the CD4+ HLA-DR+ and the CD4+ CD27- subpopulations revealed that the CD4+ HLA-DR+ cells produced significantly higher levels of IL-5 than the CD4+ HLA-DR- cells (P = 0.04), and the CD4+ CD27- cells produced significantly higher levels of both IL-4 and IL-5 than the CD4+ CD27+ cells (P < 0.05 and P < 0.001 respectively). Thus, while the CD4+ CD27- and CD27+ subpopulations contain Th1 and Th0 cells, only the CD4+ CD27- population contains the Th2 cells (producing both IL-4 and IL-5).     

Gastrointestinal nematode infections of first-grazing season calves in Western Europe: general patterns and the effect of chemoprophylaxis

Research on the prevention of gastrointestinal nematode infections of cattle has mainly concentrated on comparing a specific chemoprophylactic treatment system to an untreated control group on a particular farm. Here, the results from analysis of 85 studies involving over 2000 first grazing season (FGS) calves put onto pasture for at least 4 months from late spring/early summer over a 26-year period in 13 countries in Western Europe are presented. Both control and chemoprophylactic treated FGS calf groups were considered. All chemoprophylactic systems (slow- and pulse-release boli, strategic treatments) were given early in the grazing season. Two general infection levels emerged--'sub-clinical' (32 studies) and 'clinical' (53 studies). The 'sub-clinical' infections were characterised by no clinical symptoms of parasitic gastroenteritis (PGE) being observed in the control groups. Mean faecal egg counts in the 'clinical' control groups were significantly higher than those for 'sub-clinical' control groups for almost the entire season with overall peaks of 275 and 100 EPG respectively. Maximum pasture larval counts were also significantly higher in the 'clinical' control groups with 44% of 'clinical' pastures > 10,000 L3 kg(-1) dry herbage by the end of the FGS, compared to only 15% of 'sub-clinical' pastures. There was a significant positive relationship between log transformed worm burdens from tracers put onto pastures for 2 weeks and the corresponding pasture larval count. No evidence of density dependence in tracer worm burden was observed. Weight gains in the 'clinical' control groups (375 g/day) were significantly lower than those of the 'sub-clinical' control groups (530 g/day). No symptoms of PGE were observed in any of the chemoprophylactic treated groups, but in those studies with an outbreak of PGE in the control group, the treated groups had significantly higher faecal egg and pasture larval counts than treated groups in 'sub-clinical' studies. The overall weight gain in chemoprophylactic treated calves in 'clinical' studies (600 g/day) was significantly lower than the chemoprophylactic treated calves in 'sub-clinical' studies (690 g/day), and was not significantly different from the weight gain of control calves in 'sub-clinical' studies. These results indicate that on heavily infected pastures, chemoprophylaxis will prevent PGE, but calves will still suffer production losses.     

Intrinsic and required dynamics of a simple bat-ball skill

Three experiments investigated the coordination dynamics of a simple bat-and-ball skill: cyclically striking a ball suspended by a string with a pendular bat. The relative phase phi between the bat and ball is dictated by the potential function V(phi) = k sin phi and the difference delta omega in their uncoupled frequencies. For various delta omega, phi and its standard deviation were measured in the absence of any environmental restraints (intrinsic dynamics) and when the ball had to reach resistive or nonresistive targets at set distances (required dynamics). Results support the dynamical theory of coordination patterns (G. Sch?ner & J.A.S. Kelso, 1988a, 1988c), particularly the hypothesis that required dynamics are understandable as the addition of terms to the potential governing the intrinsic dynamics.