The extent and patterns of usage of Agent Orange and other herbicides in Vietnam

Herbicides including Agent Orange were sprayed by United States forces for military purposes during the Vietnam War (1961-1971) at a rate more than an order of magnitude greater than for similar domestic weed control. In 1974, the US National Academy of Sciences published estimates of the extent and distribution of herbicides sprayed. Here we present revised estimates, developed using more-complete data. The spray inventory is expanded by more than seven million litres, in particular with heavily dioxin-contaminated herbicides. Estimates for the amount of dioxin sprayed are almost doubled. Hamlet census data reveal that millions of Vietnamese were likely to have been sprayed upon directly. Our identification of specific military herbicide targets has led to a more coherent understanding of spraying. Common errors in earlier interpretations of the spray data are also discussed.     

Theophrastus on Lyngurium: Medieval and Early Modern Lore from the Classical Lapidary Tradition

The ancient philosopher Theophrastus (c. 371-285 BC) described a gemstone called lyngurium, purported to be solidified lynx urine, in his work De lapidibus ('On Stones'). Knowledge of the stone passed from him to other classical authors and into the medieval lapidary tradition, but there it was almost always linked to the 'learned master Theophrastus'. Although no physical example of the stone appears to have been seen or touched in ancient, medieval, or early modern times, its physical and medicinal properties were continually reiterated and elaborated as if it did 'exist'. By the seventeenth century, it began to disappear from lapidaries, but with no attempt to explain previous authors' errors since it had never 'existed' anyway. In tracing the career of lyngurium, this study sheds some light on the transmission of knowledge from the classical world to the Renaissance and the changing criteria by which such knowledge was judged.     

Summer food habits of coyotes in central Wyoming

Summer food habits of coyotes ( Canis latrans ) were investigated on a 3100-km 2 area in central Wyoming, divided into one deer-use area and five non-deer areas. Analysis of 404 scats (fecal samples) revealed an overall average of 63 percent occurrence of native ungulates, 63 percent leporids, 46 percent rodents, 14 percent livestock, and 11 percent birds. Pronghorn ( Antilocapra Americana ) was the ungulate most frequently consumed, occurring in about 87 percent of the scats. Mule deer ( Odocoileus hemionus ) occurred in only 8 percent, and in 5 percent the native ungulate remains were not identifiable beyond order. This large percentage of big game in the diet is apparently unusual, because big game has been of minor importance in most coyote food-habit studies. The high incidence of leporids is consistent with other studies performed in arid intermountain areas. Although cricetines, especially deer mice ( Peromyscus maniculatus ), were trapped consistently in all habitats, months, and trapping areas, they were found in scats at a lower frequency than microtines and sciurids. This suggests a coyote hunting strategy that selected for the latter two groups.     

Temperature and salinity relationships of the Nevadan relict dace

Pyramid Lake fish populations were sampled with nets on a monthly basis from November 1975 through December 1977. Fish species were taken in the following order of numerical relative abundance: tui chub ( Gila bicolor ), Tahoe sucker ( Catostomus tahoensis ), Lahontan cutthroat trout ( Salmo clarki henshawi ) including cutthroat-rainbow hybrids, cui-ui ( Chasmistes cujus ), and Sacramento perch ( Archoplites interruptus ). Relative abundance estimates are discussed with respect to seasonal availability, spatial distribution of the fish, sampling bias of the fishing methods, and biomass of the fish. Recent temporal trends in the population structure of the lake are presented.     

管理人员和投资人应该了解知识产权：知识产权的评估、保护及利用指南

知识产权（IP，Intelligence Property）是在知识实现的过程中确立的权力，例如在写作、艺术、音乐及发明的过程中，IP是由法律创造的所有权的捍卫者，它是由政府专业行政部门自动授与或者判决的。尽管它是无形的，但IP和银行户头及国籍一样是实实在在的。只有那些属于一定范畴的智力表现方式才受到保护，允许所有者防范未经授权的使用。而其他不属于独创的东西是不能受到保护的，它们是属于公共的。     

Contributions to the life history of Sacramento perch, Archoplites interruptus, in Pyramid Lake, Nevada

During a two-year period (1976&ndash;1977), 180 Sacramento perch ( Archoplites interruptus ) were sampled from Pyramid Lake, Nevada, on a monthly basis using several capture methods in all lake areas. Age and growth determinations of these fish were inconsistent with previous research on this species. Sacramento perch are entirely carnivorous, adults feeding primarily on tui chub ( Gila bicolor ). Fish accounted for 6 percent of the diet (by volume) of Sacramento perch less than 300 mm fork length, and 98 percent for those exceeding 300 mm. Amphipods, Odonata, and Chironomidae composed 6.3, 5.7, and 1.8 percent, respectively, of the stomach contents by volume for all sizes combined. Females spawned from June to August when water temperatures approached 20 C, and their gonad weight was about 6 percent of the total body weight. A sample of 20 female perch had a mean fecundity of 84,203 eggs. The mean diameter of mature eggs was 0.88 mm. Sacramento perch almost exclusively inhabit the littoral zone of Pyramid Lake. Activity, as indicated by net catches, was greatest during the warm months of May to October. Monthly catches were significantly correlated with temperature (r = 0.577, P < 0.01). No short-term changes in population abundances were observed during 1976&ndash;1977.     

Composition and abundance of periphyton and aquatic insects in Sierra Nevada, California, stream

The species composition of periphyton and benthic insect communities and abundances of common taxa (&;gt;0.1&;#37; of individuals) were examined during snow-free months in Convict Creek, a permanent snowmelt- and spring-fed stream in the Sierra Nevada of California. The communities were highly diverse. The most abundant taxa in the periphyton were diatoms ( Achnanthes minutissima, Cocconeis placentula lineata, Cymbella microcephala, C. sinuata, Fragilaria construens, F. crotonensis , Navicula spp., Synedra acus , and S. rumpens ), except in late spring and summer when several seasonal blue-green algae ( Chamaesiphon incrustans, Lyngbya spp. and Oscillatoria spp.) are at their maximum densities. Most common periphyton taxa vary systematically in abundance with season, but relative abundances of taxa also appear to be influenced by streambed scouring and by concentrations of ambient nutrients. Data on population densities and length frequencies of larval and nymphal stages of common benthic insects and occurrences of pupal and adult stages were examined to determine life history patterns. Taxa hatching in winter and spring and abundant as immatures in late spring include ephemeropterans ( Epeorus longimanus, Drunella flavilinea , and Caudatella heterocaudata ), plecopterans ( Calineuria californica, Doroneuria baumanni, and Pteronarcys princeps ) and dipterans ( Cryptolabis sp.). Common taxa hatching in late spring or summer are the plecopteran Malenka ( californica? ) and the trichopterans Arctopsyche grandis and Rhyacophila acropedes . Several bivoltine and multivoltine ephemeropterans ( Baetis devinctus and B. tricaudatus ) and dipterans ( Simulium spp. and Chironomidae) have summer cohorts. Taxa hatching in late summer or autumn and most abundant in autumn include ephemeropterans ( Baetis spp., Ephemerella infrequens, Epeorus dulciana, Ironodes lepidus , and Paraleptophlebia pallipes ), trichopterans ( Hydropsyche oslari, Lepidostoma spp., Glossosoma califica, Micrasema sp., Brachycentrus americanus, Neophylax sp., and Rhyacophila vaccua ) and dipterans ( Antocha monticola, Pericoma sp., and Chironomidae). Major recurring events that may influence life history patterns and structure of the benthic insect community are (1) near-freezing, nighttime winter water temperatures and occasional anchor ice, (2) a prolonged period of high discharge in late spring and early summer (3) a brief summer, and (4) a prolonged period of moderate stream discharge in autumn when the substratum is stable and food is abundant.     

Zoogeographic patterns and faunal change of South Dakota fishes

We summarized historic and recent fish distributions in South Dakota and analyzed fish faunal similarity at 2 spatial scales (geomorphic province and river drainage) for both historic (native) and recent (post-1990) faunas. We quantified zoogeographic patterns between geomorphic provinces and among neighboring river drainages for historic and recent faunas. We also quantified faunal change (species losses and additions) between provinces and among drainages. Ninety-seven fishes were native to South Dakota, but 111 fishes were present in recent collections because 8 native species were missing, and 22 nonnatives were present. There was high β diversity among historic and recent river drainage fish faunas, but there was between 22% and 56% faunal change between periods. Recent faunas were homogenized compared to historic faunas at both provincial and river drainage spatial scales. Patterns of nonnative species establishment were geographically distinct from patterns of native species loss. Most nonnative species additions were in cold-water or human-made habitats of the Great Plains. Most native species declines stemmed from warm water streams of the Central Lowlands and Missouri River valley. Conservation of rare and declining native species and containment of nonnatives are both necessary to preserve historical patterns of fish biodiversity in South Dakota.     

Looking for structure in all the wrong places: Ramsey sentences, multiple realisability, and structure

‘Epistemic structural realism’ (ESR) insists that all that we know of the world is its structure, and that the ‘nature’ of the underlying elements remains hidden. With structure represented via Ramsey sentences, the question arises as to how ‘hidden natures’ might also be represented. If the Ramsey sentence describes a class of realisers for the relevant theory, one way of answering this question is through the notion of multiple realisability. We explore this answer in the context of the work of Carnap, Hintikka and Lewis. Both Carnap and Hintikka offer clear structuralist perspectives which, crucially, accommodate the openness inherent in theory change. Unfortunately there is little purchase for a viable form of realism in either case. Lewis’s approach, on the other hand, offers more scope for realism but, as we shall see, concerns arise as to whether a relevant form of structuralism can be maintained. In particular his thesis of Ramseyan humility undermines certain conceptions of scientific laws that the structural realist might naturally cleave to. Our overall conclusion is that the representational device of Ramsey sentence plus multiple realisability can accommodate either the structuralist or realist aspects of ESR but has difficulties capturing both.     

Association between GTPase activators for Rho and Ras families.

The ras-related low-molecular-mass GTPases participate in signal transduction involving a variety of cellular functions, including cell-cycle progression, cellular differentiation, cytoskeletal organization, protein transport and secretion. The cycling of these proteins between GTP-bound and GDP-bound states is partially controlled by GTPase activating proteins (GAPs) which stimulate the intrinsic GTP-hydrolysing activity of specific GTPases. The ras GTPase-activating protein (Ras-GAP) forms a complex with a second protein, p190 (M(r) 190,000), in growth-factor stimulated and tyrosine-kinase transformed cells. At its carboxy-terminal end, p190 contains a region that is conserved in the breakpoint cluster region, n-chimaerin, and Rho-GAP. Each of these three proteins exhibits GAP activity for at least one member of the rho family of small GTPases. We have tested recombinant p190 protein for GAP activity on GTPases of the ras, rho and rab families, and show here that p190 can function as a GAP specifically for members of the rho family. Consequently, the formation of a complex between Ras-GAP and p190 in growth-factor stimulated cells may allow the coupling of signalling pathways that involve ras and rho GTPases.