bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fossil Beetle Evidence for Climatic Change 18,000–10,000 years B.P. in South-Central Chile
Authors: Hoganson John W. , Ashworth Allan C. 
Published: July 2006

AbstractCold-adapted beetles colonized the lowlands of the Lake Region of south-central Chile following the retreat of glaciers from their maximum extent at about 19,500 yr B.P. The beetle fauna from 18,000 to 14,000 yr B.P. was characterized by species of moorland habitats. This fauna was species-poor compared to later faunas of the postglacial interval. By 14,000 yr B.P. arboreal species were replacing species of open habitats, reflecting a change toward a warmer climate. By about 12,500 yr B.P. fossil beetle assemblages consisted entirely of rain forest species. The fauna of the postglacial interval was about five times as species-rich as that of the glacial interval. The change in species composition and greater diversity of the beetle fauna was produced by an increase in mean annual temperature estimated to be about 4°–5°C. This was the last major climatic change to affect profoundly the biota of the middle latitudes of South America. The fossil beetle assemblages do not imply a reversal to a colder climate at the time of the European Younger Dryas interval between 11,000 and 10,000 yr B.P.
Short-Duration Holocene Lakes in the Mojave River Drainage Basin, Southern California
Authors: Enzel Yehouda , Brown William J. , Anderson Roger Y. , McFadden Leslie D. , Wells Stephen G. 
Published: July 2006

AbstractStratigraphic, sedimentologic, and pedologic studies of beach ridge and lacustrine deposits indicate that up to five times during the Holocene, shallow lakes covered Silver Lake playa in southeastern California for periods of years to decades. The two youngest lacustrine events (at about 390 ± 90 yr B. P. and 3620 ± 70 yr B. P.) coincide with the early and late Neoglacial episodes of North America. Increasing evidence in recent years from other nonglaciated areas leads us to conclude that the effects of these climatic episodes were much more widespread than previously thought. The climate during these episodes was characterized by an increased frequency of winter storms in the southwestern United States, causing wetter conditions that affected diverse, hyperarid environments in the Mojave Desert and adjacent regions. We propose that this wide areal coverage was caused by large-scale, winter atmospheric circulation patterns, which are probably related to changes in sea-surface temperatures and oceanic circulation in the eastern North Pacific Ocean.
Late Wisconsin Paleoecologic Record from Swamp Lake, Yosemite National Park, California
Authors: Smith Susan J. , Anderson R. Scott 
Published: July 2006

AbstractA 7.86-m sediment core from Swamp Lake in Yosemite National Park, California, provides a continuous record of environmental change over the last ca. 16,000 yr, as inferred from pollen, macrofossil, and microscopic charcoal analyses. The core stratigraphy documents late Wisconsin (Tioga stage) deglaciation between >16,000 and 13,700 yr B.P., approximately 6000-3500 yr earlier than higher-elevation Sierra Nevada records. The core includes five volcanic ash layers, chemically identified as four Mono Craters ashes and the Tsoyawata ash (Mt. Mazama, Oregon). The fossil record shows that herbs and sagebrush dominated the glacial environment at Swamp Lake. By 12,000 yr B.P., a mixed conifer forest composed of high- and mid-elevation conifers grew around the lake, suggesting a cool, wet late-glacial environment. The modern Sierra montane forest did not become established until ca. 10,400 yr B.P., when maximum charcoal concentrations and minimum fir pollen percentages indicate an early Holocene xeric period. The record suggests that a cooling trend began ca. 6500 yr B.P. and persisted until ca. 3700 yr B.P. when the modern climatic regime was established.
Comparison of the anticoagulant effect of a direct thrombin inhibitor and a low molecular weight heparin in an acquired antithrombin deficiency in children with acute lymphoblastic leukaemia treated with l‐asparaginase: an in vitro study
Authors: Kuhle Stefan , Lau Alice , Bajzar Laszlo , Vegh Patsy , Halton Jacqueline , Cherrick Irene , Anderson Ron , Desai Sunil , McCusker Patricia , Wu John , Abshire Thomas , Mahoney Donald , Mitchell Lesley 
Published: July 2006

SummaryThrombosis occurs in 37% of children with acute lymphoblastic leukaemia (ALL) and is related to an l‐asparaginase‐induced acquired antithrombin (AT) deficiency. The incidence dictates the need for anticoagulant prophylaxis. Direct thrombin inhibitors (DTI) are independent of AT for effect and may thus have advantages in this population. The objective of this study was to determine the interaction of an AT deficiency with the anticoagulant effects of a DTI and a low molecular weight heparin (LMWH). Plasma samples from children with ALL were pooled (mean AT 0·53 U/ml). LMWH 0·3 and 0·7 U/ml or melagatran 0·3 and 0·5 μmol/l were added to the pools, then divided and AT was added back to one aliquot. In additional experiments, AT was added to AT immuno‐depleted plasma. Endogenous thrombin generation capacity (ETGC) was assessed by the continuous method. In plasma with LMWH, there was a 66–88% decrease in ETGC in AT‐normalised samples compared with neat. Conversely, no significant difference in ETGC with or without AT added for melagatran was seen. Experiments with AT‐depleted plasma showed no effect of AT level on anticoagulant activity of DTI, but a significant relationship for LMWH. By contrast to LMWH, DTI provides a consistent anticoagulant response independent of AT levels in children with AT deficiency.
Mediterranean hatchling lizards grow faster at higher altitude: a reciprocal transplant experiment
Authors: IRAETA P. , MONASTERIO C. , SALVADOR A. , DÍAZ J. A. 
Published: July 2006

Summary

In reptiles, growth is subject to proximate environmental influences, such as food availability and temperature, that may be crucial during the early stages of postnatal development. Mediterranean regions, with their severe summer drought, offer an excellent opportunity to examine the effects of environmental variations in precipitation and productivity on the timing of reproduction and growth rates of lizards.
In this study, we compared the incubation time, size at hatching, growth rates and changes in juvenile body condition of two nearby populations of the lizard Psammodromus algirus separated by 600–700 m altitude in central Spain. We combined a reciprocal incubation experiment at 27 and 30 °C with a reciprocal transplant experiment to distinguish between environmental and population‐specific sources of geographical variation.
At both temperatures, eggs from the high‐elevation site hatched sooner. Several important phenotypic traits of juveniles were primarily determined by the growing environment: the high‐elevation site provided more food and allowed hatchlings to grow faster and reach larger size.
Environmental effects overrode familial ones, as shown by the larger growth rate of half‐sibs released at the high‐elevation site. However, both the size and the growth rate of juveniles were also influenced by their mother's site of origin, which means that population differences may reflect a genetic differentiation and/or different maternal effects.
Low precipitation and associated food scarcity were seemingly the main factors constraining the growth rates of juveniles at the lowland site.
Functional analysis of the sea urchin‐derived arylsulfatase (Ars)‐element in mammalian cells
Authors: Watanabe Satoshi , Watanabe Sachiko , Sakamoto Naoaki , Sato Masahiro , Akasaka Koji 
Published: July 2006

An insulator is a DNA sequence that has both enhancer‐blocking activity, through its ability to modify the influence of neighboring cis‐acting elements, and a barrier function that protects a transgene from being silenced by surrounding chromatin. Previously, we isolated and characterized a 582‐bp‐long element from the sea urchin arylsulfatase gene (Ars). This Ars‐element was effective in sea urchin and Drosophila embryos and in plant cells. To investigate Ars‐element activity in mammalian cells, we placed the element between the cytomegalovirus enhancer and a luciferase (luc) expression cassette. In contrast to controls lacking the Ars‐element, NIH3T3 and 293T cells transfected with the element‐containing construct displayed reduced luciferase activities. The Ars‐element therefore acts as an enhancer‐blocking element in mammalian cells. We assessed the barrier activity of the Ars‐element using vectors in which a luc expression cassette was placed between two elements. Transfection experiments demonstrated that luc activity in these vectors was approximately ten‐fold higher than in vectors lacking elements. Luc activities were well maintained even after 12 weeks in culture. Our observations demonstrate that the Ars‐element has also a barrier activity. These results indicated that the Ars‐element act as an insulator in mammalian cells.
Changes in aboveground primary production and carbon and nitrogen pools accompanying woody plant encroachment in a temperate savanna
Authors: HUGHES R. FLINT , ARCHER STEVEN R. , ASNER GREGORY P. , WESSMAN CAROL A. , McMURTRY CHAD , NELSON JIM , ANSLEY R. JAMES 
Published: July 2006

AbstractWhen woody plant abundance increases in grasslands and savannas, a phenomenon widely observed worldwide, there is considerable uncertainty as to whether aboveground net primary productivity (ANPP) and ecosystem carbon (C) and nitrogen (N) pools increase, decrease, or remain the same. We estimated ANPP and C and N pools in aboveground vegetation and surface soils on shallow clay and clay loam soils undergoing encroachment by Prosopis glandulosa in the Southern Great Plains of the United States. Aboveground Prosopis C and N mass increased linearly, and ANPP increased logarithmically, with stand age on clay loam soils; on shallow clays, Prosopis C and N mass and ANPP all increased linearly with stand age. We found no evidence of an asymptote in trajectories of C and N accumulation or ANPP on either soil type even following 68 years of stand development. Production and accumulation rates were lower on shallow clay sites relative to clay loam sites, suggesting strong edaphic control of C and N accumulation associated with woody plant encroachment. Response of herbaceous C mass to Prosopis stand development also differed between soil types. Herbaceous C declined with increasing aboveground Prosopis C on clay loams, but increased with increasing Prosopis C on shallow clays. Total ANPP (Prosopis+herbaceous) of sites with the highest Prosopis basal area were 1.2 × and 4.0 × greater than those with the lowest Prosopis basal area on clay loam and shallow clay soils, respectively. Prosopis ANPP more than offset declines in herbaceous ANPP on clay loams and added to increased herbaceous ANPP on shallow clays. Although aboveground C and N pools increased substantially with Prosopis stand development, we found no corresponding change in surface soil C and N pools (0–10 cm). Overall, our findings indicate that Prosopis stand development significantly increases ecosystem C and N storage/cycling, and the magnitude of these impacts varied with stand age, soil type and functional plant traits
Variation and infectivity neutralization in influenza
Authors: Knossow Marcel , Skehel John J. 
Published: July 2006

SummaryWorldwide epidemics of influenza are caused by viruses that normally infect other species, particularly waterfowl, and that contain haemagglutinin membrane glycoproteins (HAs) to which the human population has no immunity. Anti‐HA immunoglobulins neutralize influenza virus infectivity. In this review we outline structural differences that distinguish the HAs of the 16 antigenic subtypes (H1–16) found in viruses from avian species. We also describe structural changes in HA required for the effective transfer to humans of viruses containing three of them, H1, H2 and H3, in the 1918 (Spanish), the 1957 (Asian) and the 1968 (Hong Kong) pandemics, respectively. In addition, we consider changes that may be required before the current avian H5 viruses could pass from human to human.
The potential association between smoking and endodontic disease
Authors: Duncan H. F. , Pitt Ford T. R. 
Published: July 2006

AbstractThe aim of this review was to analyse the literature to assess the possibility of an association between smoking and endodontic disease and the prognosis of endodontically treated teeth. The review of the prognosis of endodontically treated teeth involved taking account of any potential associations with smoking and endodontic disease and marginal periodontitis, and smoking and prosthodontic outcomes. In addition, the role of smoking in implant failure and surgical wound healing was analysed with a view to drawing parallels regarding the possible implications of smoking on the outcome of surgical endodontics. A MEDLINE and Cochrane library search including smoking and various endodontic keyword searches identified three papers which discussed the variables, and did not just mention them separately in the text. The literature demonstrates a paucity of evidence relating smoking with endodontic disease and prognosis, but nevertheless presents evidence of a possible influence on the prognosis of endodontically treated teeth in smokers and a likely increase in surgical complications. The possible merits of a smoking cessation protocol prior to surgical endodontics are also discussed.
Effect of heat sterilization on surface characteristics and microstructure of Mani NRT rotary nickel–titanium instruments
Authors: Alexandrou G. , Chrissafis K. , Vasiliadis L. , Pavlidou E. , Polychroniadis E. K. 
Published: July 2006

AbstractAim  To evaluate the effect of repeated dry heat sterilization on surface characteristics and microstructure of Mani nickel–titanium rotary instruments.Methodology  Thirty‐three new Mani NRT instruments, size 30, taper 0.04 and 25 mm in length were examined. Twenty‐seven instruments were divided into three groups for surface characterization by scanning electron microscopy (SEM). In the first group (n = 3), instruments were examined in the ‘as‐received’ condition and after they had been subjected to 11 sterilization cycles. In the second and third subgroups (n = 12), 12 instruments were prepared for cross‐section and a further 12 for longitudinal sectional analysis and evaluated in subgroups of three, after 0, 1, 6 and 11 sterilization cycles. The remaining six instruments were analysed with differential scanning calorimetry (DSC), three in the ‘as‐received’ condition and three after being subjected to 11 cycles of sterilization.Results  Scanning electron microscopy observations indicated the presence of debris, pitting and deep milling marks in both new and sterilized files. After 11 sterilization cycles, debris remained and surface roughness was increased significantly (P = 0.05). DSC analyses showed that the specimens in the ‘as‐received’ condition and after 11 sterilization cycles were in the austenite phase or a mixture of austenite and R‐phase at 37 °C.Conclusions  The machining defects and structural imperfections of new Mani instruments are indicative of the difficulty in manufacturing nickel–titanium endodontic instruments. DSC measurements suggest that Mani instruments are capable of superelastic behaviour under clinical conditions.
Efficacy of automated versus hand instrumentation during root canal retreatment: an ex vivo study
Authors: De Carvalho Maciel A. C. , Zaccaro Scelza M. F. 
Published: July 2006

AbstractAim  To compare automated and manual instrumentation techniques for removing filling material from root canal walls during root canal retreatment.Methodology  One hundred extracted human single‐rooted teeth were root filled and stored. Specimens were divided into two groups: group A, Endofill plus gutta‐percha; group B, Sealer 26 plus gutta‐percha. The filling material was removed using the following techniques: group I – Gates–Glidden and K‐type files; group II – ProFile; group III – ProTaper; group IV – K3; group V– Micro Mega Hero 642. The remaining filling debris on the root canal walls were assessed radiographically, images were digitized and analysed using Image ProPlus software. The roots were split for evaluation in a stereomicroscope by epiluminescence and photomicrographs were taken for further analysis. The area covered with filling debris was analysed by means of Student's t‐test to compare the evaluation methods. The student's t‐test was also used to compare the removal of filling materials. An anova test was applied to compare the different techniques (P < 0.05).Results  A significant difference occurred between radiographic and photomicrographic evaluation methods (P < 0.05). No significant difference was observed between the filling materials on terms of their removal (P > 0.05). Manual instrumentation left more filling debris on the root canal walls when compared to K3 (P < 0.05) and ProTaper (P < 0.01).Conclusions  A photomicrographic method by epiluminescence was more effective than the radiographic method to evaluate filling debris. There was no significant difference between the filling materials in terms of their removal. K3 and ProTaper were more efficient than manual instrumentation.
Reassessment of Some Fruit and Vegetable Pectin Levels
Authors: BAKER ROBERT A. 
Published: July 2006

ABSTRACTSeveral reviews of pectin as a soluble fiber have included unreliable tables of pectin content for fruits and vegetables. Values given for ranges of pectin content in the fresh, edible portion are actually presented in original reports variously as peel pectin content, dry weight values, soluble rather than total pectins, and some values have been for unripe fruit. This has resulted in reporting pectin levels for some products that may be 2‐10 times higher than other published data on the same product. This report examines the original sources and errors of such data and, when available, provides other more substantiated published values.
Citrus Tissue Extracts Affect Juice Cloud Stability
Authors: CAMERON RANDALL G. , BAKER ROBERT A. , GROHMANN KAREL 
Published: July 2006

ABSTRACTSalt extractable proteins were isolated from hand expressed juice, rag and peel of Valencia oranges. Each tissue extract was divided into dialysis supernatant (DS) and precipitate (DP) (forms during dialysis). DP, DS and DS heated for 2 min at 80°C (HDS) were added to pasteurized, reconstituted frozen concentrated orange juice at 5 U · mL−1 of pectinmethylesterase. Samples were incubated either at 25°C for 14 days or 4°C for 28 days and periodically sampled to determine the effects of tissue extracts on juice cloud stability. Tissue specific differences were observed for the rate of juice cloud precipitation and among the HDS, DS, and DP fractions of a given tissue. HDS fractions destabilized juice cloud more rapidly than DS or DP at both 25 and 4°C.
Inorganic Cations and Polyamines Moderate Pectinesterase Activity
Authors: LEITING V.A. , WICKER L. 
Published: July 2006

ABSTRACTInorganic and organic cations influenced pectinesterase (PE) activity and solubilization from Marsh grapefruit pulp. Activity increased to 281%, 183%, and 130% with lead acetate (6.8 mM), ferric chloride (0.2 mM), and calcium chloride (20 mM), respectively. The polyamines, putrescine, spermidine, and spermine had negligible stimulating effect. All cations tested inhibited PE activity at higher concentrations. Solubilization of total PE was decreased and thermostable PE (TS‐PE) was not affected by polyamines. There was a progressive decline in total PE activity above 1.6 mM spermidine, 7.6 mM putrescine and 20.0 mM spermine. Loss of activity upon solubilization suggests that the TL‐PE‐pectate complex stabilized TL‐PE. No change in TS‐PE activity suggests that it may be bound with greater affinity, physically entrapped, or non‐electrostatically bound.
Biopolymers Produced by Cross‐linking Soybean 11S Globulin with Whey Proteins using Transglutaminase
Authors: YILDIRIM M. , HETTIARACHCHY N.S. 
Published: July 2006

ABSTRACTHeterogeneity of biopolymers was determined by cross‐linking acetylated‐11S acidic subunits (Ac‐11S) of soy protein with α‐lactalbumin and β‐lactoglobulin. The extent of polymerization was determined by electrophoresis and HPLC. Differential scanning calorimetry (DSC) was used to determine thermal properties of starting proteins and biopolymers. HPLC data demonstrated the absence of biopolymers from Ac‐11S, acetylated α‐lactalbumin and acetylated β‐lactoglobulin when each was incubated separately with transglutaminase (TG). However, Ac‐11S formed biopolymers with α‐lactalbumin and β‐lactoglobulin when TG was added. TG catalyzed the formation of heterologous and homologous biopolymers from whey protein isolate (WPI) and soybean 11S globulin (11S). Cross‐linking WPI and 11S provided biopolymers with improved heat stability which may be useful to provide functionality to food products.
Water Uptake, Protein Solubility, and Protein Changes of Cod Mince Stored on Ice as Affected by Polyphosphates
Authors: CHANG C.C. , REGENSTEIN J.M. 
Published: July 2006

ABSTRACTWater uptake ability (WUA) and protein solubility of cod mince were higher with sodium hexametaphosphate (SHMP) than with sodium tripolyphosphate (STP) or untreated controls during ice storage. WUA increased significantly with SHMP concentration up to 0.7% SHMP but above that WUA decreased, although protein solubility continued to increase. The SDS‐PAGE results showed that extraction of a specific amount of water‐soluble protein, perhaps including some myosin heavy chain (MHC, 200 kd), correlated with high WUA. However, excess extraction of MHC may cause destruction of the structural matrix of the insoluble protein network, preventing it from holding water.
Lactate Dehydrogenase Activity as an Endpoint Heating Indicator in Cooked Beef
Authors: STALDER J.W. , SMITH G.L. , KEETON J.T. , SMITH S.B. 
Published: July 2006

ABSTRACTLactate dehydrogenase (LDH, E.C. 1.1.1.27) activity, specifically LDH5 isoenzyme, declined significantly when bovine Semimembranosus (SM) slurries were heated from 57° to 66°C. When SM whole muscle roasts were brine pumped and oven‐cooked, total LDH and specific activities declined proportionately from 57° to 63°C resulting in almost no activity at 63°± 0.5°C. LDH activities were consistently higher in younger cattle and lower in older cattle for SM, Infraspinatus (IN) and Longissimus dorsi (LD) muscles and were lowest overall in the IN. LDH colorimetric and fluorescent assays were more accurate indicators for predicting beef roast heating temperature endpoints between 60° and 63°C than the USDA‐FSIS method.
Pectic Substance Degradation and Texture of Carrots as Affected by Pressurization
Authors: KATO NORIKO (HYAKUMOTO) , TERAMOTO AI , FUCHIGAMI MICHIKO 
Published: July 2006

ABSTRACTHeated pectin was degraded by transelimination (β‐elimination) above pH 5 and by hydrolysis below pH 2, but pressurized pectin did not degrade. Thus cooked carrots decreased in firmness, but pressurized carrots did not. Pressurizing above 200 MPa slightly increased rupture strain. Galacturonic acid levels decreased in carrots cooked for 30 min. Total pectin in pressurized carrots was the same as in cooked for 3 min. However, with increased pressure, the amount of high methoxyl pectin in carrots decreased while low methoxyl pectin increased. Thus, the effects of pressurization on pectin degradation (transelimination) and texture of carrots were different from those of heating.