Synthesis of 3Z, 6Z-Dienoic Acids

3Z,6Z-Dienoic acids (C₈-C₁₂ and C₁₈) were for the first time synthesized by coupling 2-acetylenic bromides and 2-(3′-butynyloxy)-tetrahydropyrane followed by stereoselective hydrogenation and oxidation.     

研究报告：MWNTs/PMMA薄膜对大鼠棕色脂肪来源的心脏干细胞生物学特性的影响

近年来,鉴于心肌组织独有的电生理特性,应用导电纳米材料作为细胞支架开展心肌组织工程研究取得明显进展．碳纳米管材料具有良好的力学性能和导电特性,前期研究表明,其具有促进新生鼠心肌细胞中未成熟心肌细胞增殖与成熟心肌细胞进一步发育的作用,但尚未见碳纳米管材料对棕色脂肪来源的心脏干细胞(CSCs)生物学特性影响的研究报道．为此,本研究首先采用凝胶-溶胶法制备了羧基化多壁碳纳米管和聚甲基丙烯酸甲酯 (MWNTs/PMMA)薄膜,并通过一系列细胞学、免疫细胞化学及电镜检测方法,系统评价了MWNTs/PMMA薄膜对大鼠棕色脂肪CSCs活力、增殖能力及向心肌分化效率的影响．研究发现,与明胶材料相比,MWNTs/PMMA薄膜对棕色脂肪CSCs活力、增殖能力有明显促进作用,并且明显增强其向心肌细胞分化的能力,分化的心肌细胞具有明显可见的肌管结构,并且表达介导细胞间电化学传导的缝隙连接蛋白connexin43．此外,超微结构观察发现碳纳米管与细胞膜间及细胞与细胞之间可直接形成紧密连接,调控细胞行为．本研究首次探讨了碳纳米管导电材料对棕色脂肪CSCs生物学特性影响的规律,证实碳纳米管导电材料具有良好的促心肌细胞分化作用．作为一种新型导电纳米材料,碳纳米管在心肌组织工程研究中具有良好的应用前景,未来有望在心肌组织体外构建及心肌梗死治疗性应用中发挥潜在的价值．     

Influence of diet on biology and life-table parameters of the predacious mite Euseius scutalis (A.H.) (Acari: Phytoseiidae)

Abstract

Studies on the developmental duration, immature survival, longevity, reproduction, and life-table parameters of the predatory mite, Euseius scutalis Athias-Henriot were carried out under laboratory conditions of 28 ± 1°C and 75 ± 5% relative humidity (RH). The food sources for the predator included Ricinus communis pollen, eggs and nymphs of Eutetranychus orientalis, moving stages of Aceria ficus and Rhyncaphytoptus ficifoliae and immature stages of Icerya aegyptica. Development was faster and reproduction was higher when E. scutalis fed on R. communis pollen, while the developmental time increased and reproduction decreased when fed on R. ficifoliae. The number of A. ficus consumed was significantly higher compared with R. ficifoliae. Life-table parameters showed that a diet of R. communis pollen provided the shortest generation time (T = 9.51511 days), female longevity (21.37 days), the highest intrinsic rate of natural increase (rm = 0.33789) and greatest total fecundity, which resulted in the high net reproductive rate (Ro = 24.906) value. Aceria ficus and R. ficifoliae showed a relatively close value of (T = 11.59057 and 11.5222), (rm = 0.218029 and 0.2158297), (λ = 1.243623 and 1.240891) and the number of eggs deposited per female per day (1.20 and 1.20 eggs/♀/day). Eggs of E. orientalis were the least favourable source of food among all food tested.     

Mortality of Baltic sea trout (Salmo trutta) after release from gillnets

We explore the mortality rate of disentangled sea trout in whitefish fishery using gillnets with a 35–43 mm bar length. The study was conducted during the main fishing seasons in the Gulf of Bothnia in the northern Baltic Sea. Overall 59.5% of the sea trout were alive at the end of a 2–7 day observation period following release from the gillnets. Altogether, 12.1% of the captured fish were found dead in gillnets and 28.4% died due to injuries during an extended observation period. The average length of the captured sea trout was 435 mm, indicating that the majority were spending their first or second year at sea. The proportion of the survived and not injured (no observed damage) fish was highest in larger fish, >450 mm. The injured and not injured fish died equally frequently. Post capture survival was not connected to the removal time from gillnets or type of observed injuries but to the type of entanglement. Most of the fish were entangled by a mesh around the body, which caused extensive scale loss and open sores on the skin. The smallest fish may have had internal wounds that were not registered in this study. These results can be used in fisheries management to estimate the mortality of multi‐species gillnet fishing to sea trout populations in relation to management actions.     

Development of monosomic alien addition lines and introgression of genes from Oryza australiensis Domin. to cultivated rice O. sativa L.

Oryza australiensis, a diploid wild relative of cultivated rice, is an important source of resistance to brown planthopper (BPH) and bacterial blight (BB). Interspecific hybrids between three breeding lines of O. sativa (2n=24, AA) and four accessions of O. australiensis (2n=24, EE) were obtained through embryo rescue. The crossability ranged from 0.25% to 0.90%. The mean frequency of bivalents at diakinesis/metaphase I in F₁ hybrids (AE) was 2.29 to 4.85 with a range of 0–8 bivalents. F₁ hybrids were completely male sterile. We did not obtain any BC₁ progenies even after pollinating 20,234 spikelets of AE hybrids with O. sativa pollen. We crossed the artificially induced autotetraploid of an elite breeding line (IR31917-45-3-2) with O. australiensis (Acc. 100882) and, following embryo rescue, produced six F₁ hybrid plants (AAE). These triploid hybrids were backcrossed to O. sativa. The chromosome number of 16 BC₁ plants varied from 28 to 31, and all were male sterile. BC₂ plants had 24–28 chromosomes. Eight monosomic alien addition lines (MAALs) having a 2n chromosome complement of O. sativa and one chromosome of O. australiensis were selected from the BC₂ F₂ progenies. The MAALs resembled the primary trisomies of O. sativa in morphology, and on the basis of this morphological similarity the MAALs were designated as MAAL-1, -4, -5, -7, -9, -10, -11, and -12. The identity of the alien chromosome was verified at the pachytene stage of meiosis. The alien chromosomes paired with the homoeologous pairs to form trivalents at a frequency of 13.2% to 24.0% at diakinesis and 7.5% to 18.5% at metaphase I. The female transmission rates of alien chromosomes varied from 4.2% to 37.2%, whereas three of the eight MAALs transmitted the alien chromosome through the male gametes. BC₂ progenies consisting of disomic and aneuploid plants were examined for the presence of O. australiensis traits. Alien introgression was detected for morphological traits, such as long awns, earliness, and Amp-3 and Est-2 allozymes. Of the 600 BC₂ F₄ progenies 4 were resistant to BPH and 1 to race 6 of BB. F₃ segregation data suggest that earliness is a recessive trait and that BPH resistance is monogenic recessive in two of the four lines but controlled by a dominant gene in the other two lines.     

CHARACTERIZATION OF NITROGEN UPTAKE BY NATURAL POPULATIONS OF AUREOCOCCUS ANOPHAGEFFERENS (CHRYSOPHYCEAE) AS A FUNCTION OF INCUBATION DURATION,SUBSTRATE CONCENTRATION,LIGHT, AND TEMPERATURE1

Nitrogen uptake studies were conducted during an aestival “brown tide” bloom in Shinnecock Bay, Long Island, New York. The same station was sampled in late July and mid-August 1995 when Aureococcus anophagefferens composed >90% and 30–40% of the total cell density, respectively. Experiments were designed to examine the effect of incubation duration on the uptake kinetics, and the effect of light and temperature dependencies of NH₄⁺, urea, and NO₃^? uptake. Maximum specific uptake rates (V'_max) decreased in the order NH₄⁺, urea, NO₃^? and were nonlinear with time for NH₄⁺ and urea, both of which exhibited an exponential decline between 1 and 10 min and then did nut significantly change for 60 min. Nitrogen uptake kinetic experiments exhibited a typical hyperbolic response for urea and NO₃^?. Half-saturation constants. (K_s) were calculated to he 0.03 and 0.12 μmol · L^?1 for urea and NO₃^?; respectively, but could not be calculated for NH₄⁺ under these experimental conditions. Nutrient uptake rate versus, irradiance (NI) experiments showed that maximum uptake rates occurred at ≤% of incident irradiance on both sampling dates and that values of V′_max-cell (NH₄⁺) were on average 30% greater than V′_max-cell (urea). A7°–9°C temperature decrease in incubation temperature between the two NI experiments in August resulted in a 30% decrease in V′_max-cell(NH₄⁺), no change in V′_max-cell(urea), and a 3–4-fold decrease in calculated K_lt values for both NH₄⁺ and urea. The results from these experiments demonstrate that A. anophagefferens has a higher affinity for NH₄⁺ and urea than for NO₃^? and that this particular species is adapted to use these substrates at low irradiances and concentrations. The data presented in this study are also consistent with the hypothesis that A. anophagefferens may be an oceanic clone that was displaced by an anomalous oceanographic event.     

Life history invariants,age at maturity and the ferox trout

Summary Data on brown trout in Norway and on Arctic char in Norway, Iceland, Greenland or Canada are used to make three points about life-history invariants. First, invariants constructed from adaptive programmes of development that are conditioned on growth and mortality rates are more complicated than those constructed solely on the basis of dimensional analysis, but are more consistent with the data. Second, if one allows the possibility of escaping a size ceiling (e.g. by switching from planktivory to piscivory) ferox trout — brown trout that are exceptionally large and long lived — are predicted with the theory only if mortality is size dependent and the growth rate on food sources with different asymptotic sizes differs. Third, a successful empirical approach for finding life-history invariants can be more fully understood as the result of adaptive programmes of development.     

Biogeographical zonation of the western Iberian peninsula on the basis of the distribution of earthworm species

We used TWINSPAN and CANOCO to investigate the biogeography of the western Iberian Peninsula on the basis of the distribution of earthworms among ninety areas of Galicia, Portugal, Asturias, León, Zamora, Salamanca, Cáceres, Badajoz and Huelva. This part of Iberia is clearly divisible into a Eurosiberian Region in the north and west and a Mediterranean Region in the south and east. For earthworm faunas, however, the limit between these regions is considerably further south than is conventionally accepted on the basis of Rivas Martinez's (1987) vegetation-type classification. Species character- istic of the Eurosiberian Region include Dendrobaena madeirensis, D. octaedra, Allolobophora caliginosa and various species of the genus Lumbricus . Within this region the earthworm fauna of Asturias is clearly distinct from that of Galicia and northern Portugal. Species characteristic of the Mediterranean Region include Allolobophora caliginosa , A. chlorotica and A. rosea , but inventories from this region are most easily identified by the absence or scarcity of those species characteristic of the Eurosiberian Region. Many areas show intermediate characteristics between the two major regions, and in some cases one region 'intrudes' into the other.