DDT: The degradation of ring-labeled14C-DDT to14CO2 in the rat

Summary Ring fission ofp, p-DDT was studied in the rat following a single oral dose of 0.74 mg/kg (1.04 Ci) of uniformly ring-labeled¹⁴C-DDT. Expired air was passed through a solution of ethanolamine-ethylene glycol monomethyl ether (12) to trap¹⁴CO₂. A total of 1.6% of the radioactivity administered was recovered in the expired air collected continually for 10 days, indicating that while degradation of the phenyl moiety is not a major route pfp, p-DDT metabolism in the rat, it is equal to the urinary excretion. Nevertheless, these results represent the most radical change accomplished in vivo of a residual insecticide yet reported in mammals.Acknowledgment. We acknowledge the secretarial work of Ms.Elaine Smolko. This study was supported by NIH fellowship No. 1 F22 ES01723-01 and No. HL16264.     

Organization of myosin molecules in the muscle thick filament

Summary Tryptic treatment of muscle thick filaments reveals the underlying backbones of aggregatedl-meromyosin as a coli of 3 secondary filaments (helical repeat 130 nm) each in turn a coli of a 3 finer ones.     

Blood plasma investigations by resonance raman spectroscopy: Detection of carotenoid pigments

Summary Using Raman spectroscopy, we demonstrate that low levels of -carotene, lycopene, and xanthophyll give rise to resonance enhanced bands in blood plasma. These results explain the significance of previously unidentified spectral maxima which have been related to the state of health of the blood donor.     

Struktur-Wirkungsbeziehungen beim menschlichen Calcitonin. III. Die biologische Aktivität verkürzter oder an den Kettenenden modifizierter,synthetischer analoger

Summary Assays of 8 synthetic analogues of human calcitonin in rats showed that their hypocalcaemic activity was drastically reduced by deletion of the C-terminal amide group, chain-shortening or opening of the disulphide ring, but unaffected or enhanced by modification of the N-terminal amino group.

---

---

II. vgl.R. Maier, B. Kamber, B. Riniker andW. Rittel, Hormon. Metab. Res.7, 511 (1975).

---

Die hier verwendete, abgekürzte Schreibweise für Peptide folgt den Empfehlungen der IUPAC-IUB Kommission für Biochemische Nomenklatur, J.B.C.247, 977 (1972). Weitere Abkürzungen: HCT, Human-Calcitonin; PCT, Schweinecalcitonin; Bmp, -Mercaptopropionsäure (Desaminocystein); NMet, Normethionin (S-Methylcystein); -OMe, Methylester.     

Differential effects of ethanol on prostaglandin responses of arterial and venous smooth muscle

Summary The present results, using isolated rat aortic strips and portal vein segments, demonstrate that ethanol, depending upon concentration, can either enhance or attenuate the contractile actions of PGF₂ on at least 2 different types of vascular smooth muscle. At the very least, the present findings question the use of ethanol as a solvent when investigating the contractile actions of PG molecules on smooth muscles.Supported by NIH grant No. HL-18015 and NIMH grant No. MH-26236. The authors are indebted to Dr.John E. Pike and Dr.John Babcock of the Upjohn Company for generously providing us with the PGF₂ used in this study.     

Ecdysone 20-hydroxylase from the midgut of the tobacco hornworm (Manduca sexta L.)

Summary An ecdysone 20-hydroxylase enzyme system that converts -ecdysone to 20-hydroxyecdysone was prepared from the midgut of the tobacco hornworm prepupa. This partially purified enzyme is NADPH dependent and is localized in the mitochondrial fraction of the midgut tissue.     

Land vehicle positioning using GPS and dead reckoning

To ensure reliable land vehicle positioning, the Global Positioning System (GPS) is one of the best techniques commonly used in present-day positioning systems. However, GPS signals are not available if line of sight with the satellites is lost. In this respect, the addition of the Dead Reckoning (DR) method to complement the GPS unit would enhance the reliability of land vehicle positioning system. For implementing the DR method, the magnetic sensor and accelerometer are used for obtaining heading and velocity or distance information. Calibration of two sensors' dynamic model and DR algorithm are also introduced in this paper. The test result utilizing the GPS and DR methods is analyzed in this paper. It utilize spositioning information from GPS receiver when GPSsignal is available, otherwise DR is started to compensate GPS outage with the GPS output as the original point. The results showed that the error in east and north produced by the DR algorithm for a short time interval can be limitedwithin an acceptable range.     

Ni2MnGa铁磁形状记忆材料

铁磁形状记忆合金 (FSMA)是在一定温度范围马氏体相稳定同时又具铁磁性的一类特殊的形状记忆合金。Ni2MnGa铁磁形状记忆合金近年来成为呈现磁场驱动大应变的新型驱动材料 ,这些应变来自磁场诱发马氏体孪晶的重排 ,而不是磁场对奥氏体至马氏体相变的作用。孪晶变体的重排在宏观上呈现为正或切应变 ,一非化学计量比Ni2 MnGa单晶于室温加 0 .4T磁场能产生6 %的应变 ,Ni Mn Ga单晶在高至 15 0Hz的交变磁场仍可得到 2 .5 %的应变。本文阐述了与这种磁控形状记忆效应相关的孪晶界迁动的磁学和晶体学理论。马氏体相的大磁晶各向异性能使磁化沿c轴方向有利 ,穿过孪晶界c轴刚好转动 90度 ,同时 ,这个孪晶界也构成了约 90度的畴界。在各向异性的情况下 ,孪晶界的迁动仅有相邻孪晶变体的Zeeman能差驱动 ,μ0 ΔMis·Hi。磁场和外应力对应变的影响通过对一简单的自由能表达式取极小值来表示 ,自由能表达式包括Zeeman能、磁晶各向异性能和外应力以及在某些情况下需考虑的内部弹性能 ,模型的所有参数可通过应力 应变曲线和磁化曲线测量得到。铁磁形状记忆合金的磁场诱发应变可类比传统热弹性形状记忆效应 ,与更为人们所熟知的磁致伸缩现象不同。     

Splitting an Ordering into a Partition to Minimize Diameter

k consisting of k clusters, with k > 2. Bottom-up agglomerative approaches are also commonly used to construct partitions, and we discuss these in terms of worst-case performance for metric data sets. Our main contribution derives from a new restricted partition formulation that requires each cluster to be an interval of a given ordering of the objects being clustered. Dynamic programming can optimally split such an ordering into a partition P^k for a large class of objectives that includes min-diameter. We explore a variety of ordering heuristics and show that our algorithm, when combined with an appropriate ordering heuristic, outperforms traditional algorithms on both random and non-random data sets.