Pixels consisting of a single vertical-cavity laser thyristor and adouble vertical-cavity phototransistor

Bidirectionally cascadable optical pixels that consist of a single-vertical-cavity surface-emitting laser (VCSEL) thyristor and a double-vertical-cavity phototransistor are proposed. Despite almost identical layer structures, each device characteristic can be independently optimized by introducing a λ/2-spacer layer into the phototransistor section. A lasing threshold of 0.8 mA and a slope efficiency of 0.25 W/A are obtained for the laser thyristor, and a flat-topped photocurrent spectrum over 30 A and a photocurrent gain of 70 A/W are obtained for the phototransistor at the resonant wavelength. This work demonstrates the possibility of monolithic integration using thermal desorption and a regrowth technique and the suitability of these devices for massively parallel optical interconnections     

New control chart for multivariate data with missing values

A new multivariate statistical quality control method has been developed. It is an extension of the method developed by Kume, which is able to find abnormal values in multivariate biochemical data of a clinical laboratory. The present method makes use of the difference between two sets of data measured from the samples of the same patient obtained on different days. The Mahalanobis' distance between two samples can be calculated from the difference of their observations. If the Mahalanobis' distance of the two data is larger than the critical value decided in advance, the reliability of the measurement is doubtful. The characteristic of the present method is that it can apply to data with missing values by estimating them from measured data. Some numerical examples are shown to demonstrate the availability of the method.     

Cyclic tensile creep behaviour of cellulose nitrate and evaluation of constitutive equations

The cyclic creep behaviour under axial tension was quantitatively investigated using non-linear viscoelastic cellulose nitrate heated at 65°C. The instantaneous strains at the instants of loading and unloading for three creep cycles and the creep strain rates during the three creep cycles were found to be influenced by the cycle numbers. However, the effect of the cycle number on the loading process was quite different from that on the unloading process in the cyclic creep deformation. The evaluation of the creep constitutive equations for the loading and unloading processes at one loading cycle deduced in the previous papers is discussed for the cyclic creep deformation. The deduced creep equations give good agreement with the actual observations for the three creep cycles independent of the cycle numbers and of the creep stress levels.     

Proteolysis of the phage lambda CII regulatory protein by FtsH (HflB) of Escherichia coli

BACKGROUND: It has been suggested that the expression of psychosis may reflect an active morbid process that is associated with increasingly poor outcome unless ameliorated by antipsychotic drugs. METHODS: The subjects of this study were 48 in-patients with schizophrenia, many of whom had been admitted before the introduction of antipsychotic drugs to rural Irish psychiatric hospitals in the late 1950s. Each patient was assessed for positive and negative symptoms, and for general and executive (frontal) cognitive function. RESULTS: After controlling for age and for duration and continuity of subsequent antipsychotic treatment, current severity both of negative symptoms and of general cognitive impairment was predicted strongly by increasing duration of initially untreated psychosis; duration of illness following initiation of antipsychotic medication failed to predict the severity thereof. Neither of these indices of illness duration predicted the severity of positive symptoms or of executive dyscontrol. CONCLUSIONS: Increasing duration of initially untreated psychosis was associated specifically with heightened accrual of prominent negative symptoms and general cognitive impairment. Executive dyscontrol, though also prominent in these patients, may be 'locked-in' at an earlier phase of the illness.     

Intersubunit structure within heterodimers of medium-chain prenyl diphosphate synthases. Formation of a hybrid-type heptaprenyl diphosphate synthase

The later work of Wittgenstein (1953) takes language and meaning as arising in use. A local 'grammar' is created. Ethical/research awarding committees have developed, and clashing, meanings about what constitutes 'good' research. The fixed rule language game of the committee is implicitly powerful because it is part of well-rehearsed societal narratives which equate science and knowledge. This creates a force on the qualitative researcher to conform to the authoritative grammar which it is difficult to counter. In these circumstances, qualitative researchers may choose to inhabit two, parallel research universes by 'storying' their research proposal according to the audience. But a question arises as to whether ethical approval has been gained when a 'Trojan horse' approach is used. Moving between worlds involves the researcher living with a dual identity. The postmodernist movement away from structure, form and singular truth is seen as setting a context for a new archaeology of knowledge which transcends good/bad dichotomies in relation to research. The qualitative researcher is encouraged to enter into dialogical communication with committees with the hope that a shared grammar may emerge.     

Human papillomavirus type 16 DNA detected by the polymerase chain reaction in non-cancer tissues of the head and neck

Cancer-free tissues from various anatomical subsites in the head and neck were examined by the polymerase chain reaction (PCR) for the incidence of human papillomavirus (HPV) types 16 and 18. We detected HPV-16 DNA in 9 of 103 samples (8.7%), including specimens from the paranasal sinuses, tonsil, hypopharynx and larynx. However, no HPV-16/18 DNA was detected by Southern hybridization in these 9 samples. The significance of the presence of HPV-16 DNA in non-cancer tissues is still unknown, but PCR detection only of high-risk HPV DNA in head and neck cancer should be evaluated cautiously because of its ubiquity in this region.     

Atomic force microscopy in histology and cytology

This review briefly introduces the principles of the atomic force microscope (AFM) and shows our own results of AFM application to biological samples. The AFM, invented in 1986, is an instrument that traces the surface topography of the sample with a sharp probe while monitoring the interaction forces working between the probe and sample surface. Thus, the AFM provides three-dimensional surface images of the sample with high resolution. The advantage of the AFM for biologists is that AFM can visualize non-conductive materials in a non-vacuous (i.e., air or liquid) environment. AFM images of the plasmid DNA are comparable to those by transmission electron microscopy using a rotary shadowing technique, and have the advantage of examining directly the molecule without staining nor coating. The surface structure of human metaphase chromosomes and mouse collagen fibrils demonstrated in air by the non-contact mode AFM is comparable to that obtained by scanning electron microscopy. Quantitative information on the heights of structures is further obtainable from the AFM images. Embedment-free thin tissue-sections are useful for observing intracellular structures by AFM. The present review also shows AFM images of living cultured cells which have been collected in a contact mode in liquid. This technique afforded us three-dimensional observation of the cellular movement with high resolution. Although there are some innate limitations for AFM imaging, the AFM has great potential for providing valuable new information in histology and cytology.     

Design and Synthesis of A‐Ring Simplified Pyripyropene A Analogues as Potent and Selective Synthetic SOAT2 Inhibitors

Currently, pyripyropene A, which is isolated from the culture broth of Aspergillus fumigatus FO‐1289, is the only compound known to strongly and selectively inhibit the isozyme sterol O‐acyltransferase 2 (SOAT2). To aid in the development of new cholesterol‐lowering or anti‐atherosclerotic agents, new A‐ring simplified pyripyropene A analogues have been designed and synthesized based on total synthesis, and the results of structure–activity relationship studies of pyripyropene A. Among the analogues, two A‐ring simplified pyripyropene A analogues exhibited equally efficient SOAT2 inhibitory activity to that of natural pyripyropene A. These new analogues are the most potent and selective SOAT2 inhibitors to be used as synthetic compounds and attractive seed compounds for the development of drug for dyslipidemia, including atherosclerotic disease and steatosis.     

Gait motion for naturally curving variously shaped corners

Modeling the curving motion of humans in actual environment is rarely done because of the complexity and variability of the turning motion. In this study, various gait motions, including straight, round corner, and circular walks, were recorded and analyzed using factor analysis. As a result, we successfully extracted several factors that represent turning motions, such as long stride motion, turning motion led by the inner leg, and turning motion led by the outer leg. In particular, we found that the natural curving motion, which is a motion that results when turning around a round corner, is widely and continuously distributed on the factor space. Although several typical stepping strategies were reported by related studies, we found that the stepping motion changes between straight and turning gaits in the factor space during natural curving motions. Thus, the classification of curving motion into several typical distinct stepping patterns is probably insufficient to understand the natural curving motion. Furthermore, natural curving motions that comprise circular curving motions that were believed to represent typical curving motions was not validated. On the other hand, this result also suggests the possibility of generating curving motions for a physical assistant robot by combining straight gait and circler curving motion.