Tree-ring-drought relationships in the hudson valley, new york

Annual tree-ring chronologies from certain well-drained sites in the Hudson Valley of New York record past changes in temperature and precipitation. This information accounts for much of the July variation in Palmer drought severity indices during the period 1931 to 1970 and is used to develop a preliminary reconstruction of drought as long ago as 1728.     

Earthquakes, faults, and nuclear power plants in southern new york and northern new jersey

Seismic activity in the greater New York City area is concentrated along several northeast-trending faults of which the Ramapo fault appears to be the most active. Three nuclear power plants at Indian Point, New York, are situated close to the Ramapo fault. For a reactor site in use for 40 years, the probability that the site will experience an intensity equal to or in excess of the design (safe shutdown) earthquake is estimated to be about 5 to 11 percent.     

Ozone concentrations in new jersey and new york: statistical association with related variables

The concentrations of ozone at nine measurements sites in New Jersey and New York during the period 1 May through 30 September 1973 have been examined. Daily fluctuations in the ozone concentrations at any two sites are highly correlated. The concentrations are lower with low levels of solar radiation and also with high wind speed. The average ozone concentration shows only minor differences between weekdays and weekends, despite markedly different traffic patterns.     

Early silurian spore tetrads from new york: earliest new world evidence for vascular plants?

Several taxa of abundant cutinized trilete spores from earliest Silurian shale in New York predate by almost an entire period vascular land plant megafossils. Paleoecological evidence suggests that these spores may represent vascular land or semiaquatic plants but a bryophytic origin cannot be precluded on the basis of spore characters. An algal origin is considered unlikely.     

Early land animals in north america: evidence from devonian age arthropods from gilboa, new york

A new fossil site near Gilboa, New York, is one of only three where fossils of terrestrial arthropods of Devonian age have been found. The new Gilboan fauna is younger than the other two but richer in taxa. Fragmentary remains and nearly whole specimens assigned to Eurypterida, Arachnida (Trigonotarbida, Araneae, Amblypygi, and Acari), Chilopoda [Craterostigmatomorpha(?) and Scuterigeromorpha(?)], and tentatively to Insecta (Archaeognatha) have been found. The centipedes and possible insects may represent the earliest records known for these groups.     

Chesapeake bay anoxia: origin, development, and significance

Anoxia occurs annually in deeper waters of the central portion of the Chesapeake Bay and presently extends from Baltimore to the mouth of the Potomac estuary. This condition, which encompasses some 5 billion cubic meters of water and lasts from May to September, is the result of increased stratification of the water column in early spring, with consequent curtailment of reoxygenation of the bottom waters across the halocline, and benthic decay of organic detritus accumulated from plankton blooms of the previous summer and fall. The Chesapeake Bay anoxia appears to have had significant ecological effects on many marine species, including several of economic importance.     

产胆盐水解酶植物乳杆菌降胆固醇作用的研究

采用茚三酮显色法测定了5株具有潜在益生特性的植物乳杆菌的胆盐水解酶(BSH)活性,采用邻苯二甲醛法测定了发酵上清液、菌体洗涤液和菌体破碎液中胆固醇含量,并对二者进行了相关性分析。结果表明,5株菌的BSH比活力为0.0149~0.0299U/mg总蛋白,去除胆固醇能力为37.64~47.88μg/mL。5株乳杆菌BSH活性与菌体洗涤液中胆固醇含量呈显著正相关,推断是菌株BSH水解结合胆盐生成游离胆酸,后者与胆固醇共沉淀,从而达到降胆固醇的效果。上述研究结果为利用益生菌生产具有降胆固醇功效的产品提供了理论依据。     

Fault zone connectivity: slip rates on faults in the san francisco bay area, california

The slip rate of a fault segment is related to the length of the fault zone of which it is part. In turn, the slip rate of a fault zone is related to its connectivity with adjoining or contiguous fault zones. The observed variation in slip rate on fault segments in the San Francisco Bay area in California is consistent with connectivity between the Hayward, Calaveras, and San Andreas fault zones. Slip rates on the southern Hayward fault taper northward from a maximum of more than 10 millimeters per year and are sensitive to the active length of the Maacama fault.     

盐胁迫对植物光合作用影响的研究进展

针对盐胁迫影响光合作用的几个重要方面进行了综述,主要包括盐胁迫对植物光合器官的形态结构、光合作用过程、抗氧化系统以及渗透调节物质等方面.研究表明,盐胁迫对光合作用的影响是由于不同的材料和实验方法,因此得出的结论也不同.为此盐胁迫对光系统Ⅱ(PSⅡ)的影响等问题还需进一步研究.