bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Demand for Health Insurance in the Group Setting: Can You Always Get What You Want?
Authors: Pauly Mark V. , Herring Bradley 
Published: March 2007

AbstractTo what extent do health benefits obtained in the employment‐based setting reflect individual preferences? We examine this question by comparing the relationship between person‐level characteristics and the plans they obtain in a group setting to the relationship observed in the individual insurance market, using data from the 1996‐1997 and 1998‐1999 Community Tracking Study's Household Surveys. We also examine the effect of unions on group choice. Our structural models of the demand for insurance indicate that plans obtained in the group setting often reflect underlying individual preferences for insurance, but we consistently observe significantly different effects of ethnicity and unionization.
Equilibrium in Marine Mutual Insurance Markets with Convex Operating Costs
Authors: Aase Knut K. 
Published: March 2007

AbstractThe article analyzes the possibility of reaching an equilibrium in a market of marine mutual insurance syndicates, called Protection and Indemnity Clubs, or P&I Clubs for short, displaying economies of scale. Our analysis rationalizes some empirically documented findings, and points out an interesting future scenario. We find an equilibrium in a market of mutual marine insurers, in which some smaller clubs, having operating costs above average, may grow larger relative to the other clubs in order to become more cost effective, and where medium to larger cost‐efficient clubs may stay unchanged or some even downsize relative to the others. Some of the very large clubs suffering from diseconomies of scale may have a motive to further increase relative to the other clubs. According to observations, most clubs have, during the last decade, expanded significantly in size measured by gross tonnage of entered ships, some clubs have merged, but very few seem to have decreased their underwriting activity, in particular none of the really large ones. The analysis points to the following future scenario: The small and the medium to large clubs converge in size, while there is a possibility for some very large clubs to be present as well.
Optimization of the skin multiple analyte profile bioanalytical method for determination of skin biomarkers from D‐Squame® tape samples
Authors: Hendrix S. W. , Miller K. H. , Youket T. E. , Adam R. , O'Connor R. J. , Morel J. G. , Tepper B. E. 
Published: March 2007

Background/purpose: This work was performed to optimize extraction conditions for D‐Squame® tape skin samples for use in the skin multiple analyte profile (SkinMAP) method, a Linco Research Corporation bead‐based assay for skin analytes. The experiments were designed to help identify sources of variability during extraction that may be amenable to further control.Methods: Two experimental designs were used to study factors influencing the extraction of skin samples from D‐Squame® tapes. Visually healthy skin samples were obtained from both female and male adult volar forearms. Factors studied in two experiments included: four surfactant (SDS) levels (0.02–0.2%), two buffer types [Citrate‐phosphate buffered saline at pH 5.5, phosphate‐buffered saline (PBS) at pH 7.4], two buffer volumes (1.0, 1.5 mL), two propylene glycol (PG) levels (0.1%, 1.0%), two extraction temperatures (7–10°C, 22–30+°C), two extraction times (30, 60 min), and location in sonication bath (two vectors). The response biomarkers were cortisol, fibronectin, human serum albumin, involucrin, keratin‐6 and keratins 1, 10. Skin sampling sites were also evaluated as sources of variation.Results: There was no single set of extraction conditions in our experiments that maximized recovery of all the biomarkers. SDS level had the most consistently significant (P<0.05) and directional effects on biomarker recoveries. In general, higher SDS resulted in higher recovery of all biomarkers. There was less consistency and fewer significant results for the other extraction factors.Conclusions: These data enable us to better manage SkinMAP studies and interpret their results. The use of 1.5 mL PBS containing 0.2% SDS and 0.5% PG with 30 min sonication at low (near 4°C) temperature is optimal for the quantitation of a range of SkinMAP analytes. In order to protect researchers from obtaining inflated false positive rates, it is crucial to design such studies and analyze the data using appropriate statistical methodology, especially for those studies involving only a small number of subjects.
The ‘Good Enough’ Approach to Language Comprehension
Authors: Ferreira Fernanda , Patson Nikole D. 
Published: March 2007

AbstractFerreira and colleagues argued that the language comprehension system creates syntactic and semantic representations that are merely ‘good enough’ (GE) given the task that the comprehender needs to perform. GE representations contrast with ones that are detailed, complete, and accurate with respect to the input. In this article, we review the original argument for GE processing, and we present new evidence that supports the concept: first, local interpretations are computed, which can interfere with global ones; second, new findings based on the recording of event‐related potentials show the use of simple heuristics rather than compositional algorithms for constructing sentence meaning; and recent studies show that the comprehension system has mechanisms for handling disfluencies, but they work imperfectly. We argue that the GE approach to language comprehension is similar to the use of fast and frugal heuristics for decision‐making, and that future research should explore this connection more thoroughly.
Jusa and Barsuchi Log Volcanogenic Massive Sulfide Deposits from the Southern Urals of Russia: Tectonic Setting, Structure and Mode of Formation
Authors: Glasby Geoffrey P. , Prozherova Irina A. , Maslennikov Valery V. , Petukhov Sergey I. 
Published: March 2007

AbstractThe Jusa and Barsuchi Log volcanogenic massive sulfide (VMS) deposits formed along a paleo island arc in the east Magnitogrosk zone of the Southern Urals between ca 398 and 390 Ma. By analogy with the VMS deposits of the west Magnitogrosk zone, they are considered to be Baimak type deposits, which are Zn‐Cu‐Ba deposits containing Au, Ag and minor Pb. Detailed mapping and textural analysis of the two deposits shows that they formed as submarine hydrothermal mounds which were subsequently destroyed on the sea floor under the influence of ocean bottom currents and slumping. Both deposits display a ratio of the length to the maximum width of the deposit >15 and are characterized by ribbon‐like layers composed mainly of bedded ore and consisting principally of altered fine clastic ore facies. The Jusa deposit appears to have formed in two stages: deposition of colloform pyrite followed by deposition of copper–zinc–lead sulfides characterized by the close association of pyrite, chalcopyrite, sphalerite, galena, tennantite, arsenopyrite, marcasite, pyrrhotite, bornite, native gold and electrum and high concentrations of gold and silver. The low metamorphic grade of the east Magnitogorsk zone accounts for the exceptional degree of preservation of these deposits.
Characteristics of the Bumo Gold Field, Hainan Island, China and Gold Exploration Through Soil Geochemical Surveys
Authors: Zhou Jun , Han Ping , Liu Lei , Tian Qin‐hu , Li De‐cheng 
Published: March 2007

AbstractThe Bumo gold deposit is a low‐sulfide quartz vein type deposit, situated in the west of Hainan Island, approximately 25 km southeast of Dongfang City (termed Basuo in alias). Tectonically, the SW‐NE‐oriented Gezhen Ductile‐Shearing Zone was largely attenuated in Bumo. It is hosted by gneisses and schists of Proterozoic age (locally called the Baoban Group), but the radiometric age of ores mainly is Jurassic–Cretaceous, being coeval to the regional metallogenesis along the Eurasian margin. The affinity with the Phanerozoic orogenic gold deposits is indicated by low salinity (2.4 wt% NaCl–10.3 wt% NaCl), intermediate temperature (150–300°C) and appropriate δ18O value (approximately 7–11‰). The gold metal tonnage, proved previously, within an area smaller than 1.0 km2 in the gold belt II amounted to 11.59 t, with the average gold grades for the major Au quartz veins (7 and 8) in this belt of 52.7 and 71.1 g/t, respectively. This shows significant enrichment of gold and an unusual “nugget effect”. A ring structure, mainly represented by ridges, valleys, dikes, big bull quartz veins and lithological borders or pertinent faults, marks the gold field, and its origin was linked to a possible magmatic diapir. It was viewed as macroscopic evidence that the dip angles of strata tend to decline gradually from deeper ones in the center area to nearly horizontal in the outskirts, and certain intrusion‐affiliated elements such as Bi, As and W are considerably abundant in soil samples. Two areas, namely the area A (3.06 km2) in the outskirts of the ring structure or in northeastern Bumo and the area B (1.32 km2) in the field center or to the west of the gold belts I and II, were selected for the geochemical survey in a 50 × 50‐m sampling grid. The analytical results of the samples from horizon C and in a −80 mesh size showed that the average contents of Bi, As and W amounted to 0.55, 19.3 and 3.67 ppm in the area A (1225 samples) and to 0.79, 68.3 and 4.14 ppm in the area B (529 samples), respectively. This geochemical exploration led to the discovery of several Au quartz veins in both areas A and B, which also manifested an Au nugget effect (the average Au grades between 50 and 100 g/t) in spite of their limited scales (from a couple of centimeters to 50 cm wide and from several meters to 15 m long). A mylonite zone in area A was also found by this study. An intimate spatial correlation between a lithological border (gneiss and schist or pegmatite) or the mylonite zone and Au anomalies indicates an important prospect for further gold exploration.
Dating of the Giant Huize Zn‐Pb Ore Field of Yunnan Province, Southwest China: Constraints from the Sm‐Nd System in Hydrothermal Calcite
Authors: Li Wenbo , Huang Zhilong , Yin Mudan 
Published: March 2007

AbstractThe Huize ore field, which is the most famous high‐grade Mississippi Valley‐type Zn‐Pb ore field in China, consists of the Kuangshanchang and Qilinchang deposits. The Sm‐Nd isotopic compositions of gangue calcite were analyzed to constrain the timing of mineralization. Eight calcite samples from the No. 6 orebody in the Qilinchang deposit have Sm and Nd concentrations of 1.82–25.93 and 15.25–79.02 ppm, respectively, and yielded an age of 225 ± 9.9 Ma with epsilon Nd =−10.6 and MSWD = 0.13. Five calcites from the No. 1 orebody in the Kuangshanchang deposit contain 2.37–2.90 ppm Sm and 8.18–16.85 ppm Nd, and yielded an age of 228 ± 16 Ma, with epsilon Nd =−10.6 and MSWD = 0.28. These two ages are close to the age of the Emeishan flood basalt, which is ca 255 Ma, and agree with the reported40Ar/39Ar plateau and isochron ages of the native copper mineralization related to the Emeishan flood basalt in this region, which are 226–228 Ma. Moreover, previous study shows that the magnitude of uplift resulting from the Emeishan flood basalts is >1000 m. It indicates that the Kuangshanchang and the Qilinchang deposit formed during the same geological event and originated by fluid migration during uplift resulting from the Emeishan flood basalt.
Central Roles of Small GTPases in the Development of Cell Polarity in Yeast and Beyond
Authors: Park Hay-Oak , Bi Erfei 
Published: March 2007

SUMMARYThe establishment of cell polarity is critical for the development of many organisms and for the function of many cell types. A large number of studies of diverse organisms from yeast to humans indicate that the conserved, small-molecular-weight GTPases function as key signaling proteins involved in cell polarization. The budding yeastSaccharomyces cerevisiaeis a particularly attractive model because it displays pronounced cell polarity in response to intracellular and extracellular cues. Cells ofS. cerevisiaeundergo polarized growth during various phases of their life cycle, such as during vegetative growth, mating between haploid cells of opposite mating types, and filamentous growth upon deprivation of nutrition such as nitrogen. Substantial progress has been made in deciphering the molecular basis of cell polarity in budding yeast. In particular, it becomes increasingly clear how small GTPases regulate polarized cytoskeletal organization, cell wall assembly, and exocytosis at the molecular level and how these GTPases are regulated. In this review, we discuss the key signaling pathways that regulate cell polarization during the mitotic cell cycle and during mating.
Insertion Sequence Diversity in Archaea
Authors: Filée J. , Siguier P. , Chandler M. 
Published: March 2007

SUMMARYInsertion sequences (ISs) can constitute an important component of prokaryotic (bacterial and archaeal) genomes. Over 1,500 individual ISs are included at present in the ISfinder database (www-is.biotoul.fr), and these represent only a small portion of those in the available prokaryotic genome sequences and those that are being discovered in ongoing sequencing projects. In spite of this diversity, the transposition mechanisms of only a few of these ubiquitous mobile genetic elements are known, and these are all restricted to those present in bacteria. This review presents an overview of ISs within the archaeal kingdom. We first provide a general historical summary of the known properties and behaviors of archaeal ISs. We then consider how transposition might be regulated in some cases by small antisense RNAs and by termination codon readthrough. This is followed by an extensive analysis of the IS content in the sequenced archaeal genomes present in the public databases as of June 2006, which provides an overview of their distribution among the major archaeal classes and species. We show that the diversity of archaeal ISs is very great and comparable to that of bacteria. We compare archaeal ISs to known bacterial ISs and find that most are clearly members of families first described for bacteria. Several cases of lateral gene transfer between bacteria and archaea are clearly documented, notably for methanogenic archaea. However, several archaeal ISs do not have bacterial equivalents but can be grouped intoArchaea-specific groups or families. In addition to ISs, we identify and list nonautonomous IS-derived elements, such as miniature inverted-repeat transposable elements. Finally, we present a possible scenario for the evolutionary history of ISs in theArchaea.
Biosynthesis of Ether-Type Polar Lipids in Archaea and Evolutionary Considerations
Authors: Koga Yosuke , Morii Hiroyuki 
Published: March 2007

SUMMARY

This review deals with the in vitro biosynthesis of the characteristics of polar lipids in archaea along with preceding in vivo studies. Isoprenoid chains are synthesized through the classical mevalonate pathway, as in eucarya, with minor modifications in some archaeal species. Most enzymes involved in the pathway have been identified enzymatically and/or genomically. Three of the relevant enzymes are found in enzyme families different from the known enzymes. The order of reactions in the phospholipid synthesis pathway (glycerophosphate backbone formation, linking of glycerophosphate with two radyl chains, activation by CDP, and attachment of common polar head groups) is analogous to that of bacteria.
sn
-Glycerol-1-phosphate dehydrogenase is responsible for the formation of the
sn-
glycerol-1-phosphate backbone of phospholipids in all archaea. After the formation of two ether bonds, CDP-archaeol acts as a common precursor of various archaeal phospholipid syntheses. Various phospholipid-synthesizing enzymes from archaea and bacteria belong to the same large CDP-alcohol phosphatidyltransferase family. In short, the first halves of the phospholipid synthesis pathways play a role in synthesis of the characteristic structures of archaeal and bacterial phospholipids, respectively. In the second halves of the pathways, the polar head group-attaching reactions and enzymes are homologous in both domains. These are regarded as revealing the hybrid nature of phospholipid biosynthesis. Precells proposed by Wächtershäuser are differentiated into archaea and bacteria by spontaneous segregation of enantiomeric phospholipid membranes (with
sn-
glycerol-1-phosphate and
sn-
glycerol-3-phosphate backbones) and the fusion and fission of precells. Considering the nature of the phospholipid synthesis pathways, we here propose that common phospholipid polar head groups were present in precells before the differentiation into archaea and bacteria.
Do seed banks confer resilience to coastal wetlands invaded by Typha ×glauca?
Authors: Frieswyk Christin B. , Zedler Joy B. 
Published: March 2007

Historically, seed banks conferred resilience to Laurentian Great Lakes coastal wetlands by providing propagules of many species to replace invasive plants, such as Typha ×glauca Godr. After flooding, the seed bank could allow recovery of wetland composition and structure as the water levels fall. Using the seedling emergence method to estimate seed density, species and guild richness, and floristic quality, we evaluated the resilience of five wetlands along the western coast of Green Bay, Lake Michigan by comparing seed bank attributes in areas invaded by Typha to those of neighboring uninvaded areas and to attributes of the extant vegetation. Resilience decreased from north to south among the five wetlands, mirroring a gradient of decreasing water quality. The invasive Lythrum salicaria L. dominated the seed bank of all five wetlands despite low relative abundance in the extant vegetation. The resilience of Green Bay coastal wetlands is threatened by the overwhelming presence of L. salicaria in the seed bank. Because the seed bank holds a wetland’s potential to be renewed by the natural hydrological cycle, seed bank assessment should be a routine measure of wetland resilience.
Relationships between flowering phenology, plant size, and female reproductive output in a dioecious shrub, Ilex leucoclada (Aquifoliaceae)
Authors: Torimaru Takeshi , Tomaru Nobuhiro 
Published: March 2007

Flowering phenology is critical for reproduction in dioecious species, but selection on timing of flowering may be weakened by physiological factors such as plant size, and external factors such as climate. We investigated the flowering phenology of male and female adults, and female reproductive output, in 10 patches with various sex ratios, of the dioecious shrub Ilex leucoclada (Maxim.) Makino over three consecutive years in an old-growth beech forest. Sexual dimorphism was observed in flowering amplitude, but not in other traits examined, including flowering onset date, duration, peak date, and synchrony with plants of the opposite sex in the population. Plant size had a consistent, positive effect on flowering amplitude in both sexes throughout the study period, but its effects on other factors, including the extent of fruit set, varied. Females in mixed patches showed higher fruit set than those in female patches. Furthermore, although the reproductive output of the female I. leucoclada plants is likely to be affected by flowering phenological traits in the mixed patches, the importance of these factor is probably modulated by other variables, including precipitation (which had a major effect on male flowering patterns) and the spatial distribution of the males.
Local seed rain and seed bank in a species-rich grassland: effects of plant abundance and seed size
Authors: Jakobsson Anna , Eriksson Ove , Bruun Hans Henrik 
Published: March 2007

In this study, we examined the relationship between seed size, seed rain, and seed bank in a species-rich perennial grassland in Sweden. The seed rain was monitored by 100 seed traps placed in a 10 m × 10 m area for 1 year. The seed bank was sampled by taking 100 soil samples, each in close vicinity to a seed trap. Abundance of reproductive ramets in the area was estimated, since this is likely to affect the proportion of hit seed traps and seed bank samples. When abundance of reproductive ramets was accounted for, we found a negative relationship between seed size and proportion of hit seed bank samples, but we found no relationship between seed size and proportion of hit seed traps. We found strong positive relationships between the abundance of reproductive ramets and proportion of hit seed traps and seed bank samples. We also found strong positive relationships between abundance of reproductive ramets and abundance of seeds in the seed rain and the seed bank, but no relationship between seed size and abundance of seeds in the seed rain or the seed bank. We discuss these results in the context of theory suggesting that large-seeded and small-seeded species may coexist because of a trade-off between colonization and competitive abilities, where smaller-seeded species are able to reach more sites than seeds of larger-seeded species, because they are more numerous and (or) better dispersed.
Lichens from the Hudson Bay Lowlands: diversity in the southeastern peatlands of Wapusk National Park, Manitoba
Authors: Piercey-Normore Michele D. 
Published: March 2007

Peatlands form an important component of the Northern Hemisphere. They provide substrate for lichen growth and are used by large mammals such as polar bears, caribou, and humans. This study provides the first annotated species list of lichens on the peatlands of Wapusk National Park, Manitoba. It also provides insight into the chemical and genetic diversity of members of Cladonia that dominate the peatlands. Ninety-three species of lichen-forming fungi are reported for the peatlands, fewer than that reported for the coastal beach ridges in Wapusk National Park. This study reports six species of cyanobacterial lichens and two species of Basidiomycete lichens, including two new occurrences for Manitoba, Leptogium intermedium (Arnold) Arnold and Lichenomphalia hudsoniana (H.S. Jenn.) Redhead, Lutzoni, Moncalvo, & Vilgalys. Both chemical diversity in the genus Cladonia and genetic diversity within the species, Cladonia arbuscula (Wallr.) Flotow, were lower than those of a comparable study in a more southerly location. The abundance of apothecia produced by crustose species on the peatlands suggests that crustose species were predominantly sexually reproducing. Foliose species showed production of both sexual and vegetative features, and the fruticose species were mainly vegetatively reproducing. The study raises questions on life history strategies, the influence of habitat on lichen chemistry, and genetic variation of lichen algae in northern environments.
Magnesium localization in shoot apices during flower induction in Pharbitis nil
Authors: Kobayashi Natsuko I. , Tanoi Keitaro , Nakanishi Tomoko M. 
Published: March 2007

We present the potential involvement of Mg2+ in the flowering mechanism in the shoot apex of the short-day plant Pharbitis nil (L.). To analyze elemental distribution in shoot apical meristems, fluorescence staining methods with Mag-fluo-4 AM and Fluo-3 AM were used. The former is sensitive to both Mg2+ and Ca2+, and the latter is a specific Ca2+ indicator. When plants were grown under continuous light conditions, some cells with intensive fluorescence of Mg2+ appeared in the top layers of the shoot apical meristem. During growth in the vegetative phase, cells in the center of the top layers accumulated large amounts of Mg2+. Exposure to a single 16 h short-day treatment induced the flowering process and dramatically reduced the fluorescence associated with Mg2+ accumulation in the top layers, suggesting that Mg2+ contributes to the flower induction process. The fluorescence associated with Ca2+ did not show this distribution difference between growth phases. A night-break treatment also influenced the fluorescence pattern. It was suggested for the first time that Mg2+ plays an important role in flower induction.