A role for tectal midline glia in the unilateral containment of retinocollicular axons

Retinal fibers approach close to the tectal midline but do not encroach on the other side. Just before the entry of retinal axons into the superior colliculus (SC), a group of radial glia differentiates at the tectal midline; the spatiotemporal deployment of these cells points to their involvement in the unilateral containment of retinotectal axons. To test for such a barrier function of the tectal midline cells, we used two lesion paradigms for disrupting their radial processes in the neonatal hamster: (1) a heat lesion was used to destroy the superficial layers of the right SC, including the midline region, and (2) a horizontally oriented hooked wire was inserted from the lateral edge of the left SC toward the midline and was used to undercut the midline cells, leaving intact the retinorecipient layers in the right SC. In both cases, the left SC was denervated by removing its contralateral retinal input. Animals were killed 12 hr to 2 weeks later, after intraocular injections of anterograde tracers to label the axons from the remaining eye. Both lesions resulted in degeneration of the distal processes of the tectal raphe glia and in an abnormal crossing of the tectal midline by retinal axons, leading to an innervation of the opposite ("wrong") tectum. The crossover occurred only where glial cell attachments were disrupted. These results document that during normal development, the integrity of the midline septum is critical in compartmentalizing retinal axons and in retaining the laterality of the retinotectal projection.     

The importance of temperature on storage of ground natural spices (author's transl)]

Several factors influencing the ingredients of volative oils of some ground natural spices have been investigated during storage. The effects on the aroma have been characterized sensorically; relations between the analytical and sensorical results are explained using anise as an example. Of the influencing factors studied such as packaging material, storage temperature and storage duration, the storage temperature must be regarded as the most important.     

Performance of sequential estimation for direct sequence spread spectrum code acquisition

The Sequential Estimation (SE) technique introduced by Ward was designed for the acquisition of pseudo-noise (PN) signals. It proves to be an effective model in medium SNRs as long as inverted PN sequences are not encountered. Recognizing that negative data bits invert PN sequences in spread spectrum transmissions, Chiu and Lee developed an Improved Sequential Estimator (ISE) that processes both types of sequences. The ISE design, however, erroneously despreads the incoming signal by inverting it during negative bit acquisitions. In some applications, this could be a problem, hence a Dual Correlating Sequential Estimator (DCSE) is proposed in this paper. The DCSE detects modulation errors by gathering correlation measurements from resident SE and ISE subsystems and corrects for them with an inverting mechanism. Key performance parameters such as mean timing and the variance of acquisition for the sequential estimator designs are derived via the generalized signal flow graph method and verified through simulation. In an additive White Gaussian noise (AWGN) environment, the DCSE design is shown to outperform the SE for every tested signal-to-noise ratio (SNR).Abbreviations SE sequential estimation - PN pseudo-noise - ISE improved sequential estimator - DCSE dual correlating sequential estimator - AWGN additive white gaussian noise - SNR signal-to-noise ratio     

Pyrane-derivatives as fragrances and flavors-a study on structure/odour relationships

Summary In this study several 2/H-3,4-dihydropyrane-derivatives, substituted with different unsaturated alkyl groups, have been synthesized. These compounds exhibit pleasant green, fruity and flowery fragrances. The syntheses start from 2H-3,4-dihydropyrane-2-carbaldehydes which are available by dimerisation of acroleine, meth-ylacroleine and ethylacroleine. It was shown that it is possible to induce dimerisation by ultrasonic irradiation. Subsequent Wittig and Horner-Emmons olefinations lead to the desired pyrane derivatives. The odorous character of these compounds is fully described and remarkable structure/odour relationships are discussed.

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Pyran-Derivate als Aroma- und Duftstoffe. Eine Studie über Struktur/Geruchs-Beziehungen

Zusammenfassung In der vorliegenden Untersuchung werden die Synthese und der Geruch verschiedener 2H-3,4-Dihydropyrane, die unterschiedliche olefinische Seitenketten tragen, beschrieben. Alle diese Verbindungen besitzen ein ausgeprägtes grünes, fruchtiges und blumiges Aroma. Die Synthesen nehmen ihren Ausgang von den durch Dimerisation von Acrolein, Methyl- und Ethyl-acrolein zugänglichen 2H-3,4-Dihydropyran-2-carbalde-hyden, wobei gezeigt werden konnte, daß durch Ultraschall-Bestrahlung ebenfalls Dimerisation induziert werden kann. Anschließende Wittig- bzw. Horner-Emmons Reaktionen führen zu den gewünschten Zielverbindungen. Die Geruchseigenschaften dieser Substanzen werden ausführlich beschrieben und etwaige Struktur/Wirkungsbeziehungen diskutiert.

     

The potential of serum levels of soluble tumour necrosis factor receptor I as a biochemical marker in cervical cancer

OBJECTIVES: To investigate the significance of serum levels of soluble tumour necrosis factor receptor I (sTNF-RI) as a potential biochemical marker in women with cervical cancer. DESIGN: A prospective, case-controlled study. PARTICIPANTS: Seventy-one women with cervical cancer and 33 women with myoma were enrolled in this study. METHODS: Pre-operative serum levels of sTNF-RI were measured with a standard enzyme-linked immunosorbent assay utilising murine monoclonal antibody against sTNF-RI. MAIN OUTCOME MEASURES: All data in both groups were evaluated and correlated with the pre-operative serum levels of sTNF-RI. Data analysis was carried out using ANOVA with multiple comparison and linear regression. RESULTS: The mean serum level of sTNF-RI in the cervical cancer group was significantly lower than that in the myoma group (P < 0.001). The sTNF-RI levels decreased sequentially with disease progression from Stage Ia to IIb in women with cervical cancer. The mean serum level of sTNF-RI was also significantly lower in women with positive lymph node (P < 0.05) or recurrent cancer (P < 0.001). A negative correlation was observed between serum levels of sTNF-RI and tumour size (r = -0.622, P < 0.0001). CONCLUSIONS: Decreased pre-operative serum levels of sTNF-RI are observed in women with cervical cancer. The results do not support that the use of sTNF-RI as a biochemical marker for cervical cancer.