bluuebunny/crossref_metadata_2025_split huggingface dataset:
PHYTOPLANKTON, PHOTOSYNTHESIS, AND PHOSPHORUS IN LAKE MINNETONKA, MINNESOTA1
Authors: Megard Robert O. 
Published: March 2010

The temporal and spatial variations of chlorophyll concentrations (n) and integral photosynthesis (Σp) are described for a large, morphometrically complex lake. The daily rate of photosynthesis at the average depth where illumination is optimal (pmax) increases, whereas the depth where illumination begins to be saturating (zi) decreases, as chlorophyll concentrations increase. These opposing effects influence the geometric proportions (expressed by the ratio Σp:pmax) of photosynthesis depth profiles systematically. The regression of the ratio Σp:pmax (= zi) on chlorophyll is fitted to an exponential equation with which zi can be estimated from the chlorophyll concentration. Values of zi so estimated are similar to those expected from the reciprocal relationship between zi and chlorophyll required by Lambert’s law. Therefore daily integral photosynthesis at any locality can be calculated from measurements of the chlorophyll concentration and the rate of photosynthesis in a single water sample incubated for a half day at the average depth where illumination is optimal. Chlorophyll concentrations increase as concentrations of total phosphorus increase, but generally no relationship exists between phosphorus concentrations and maximum specific rates of photosynthesis (Pmax). The linear relationship between phosphorus and chlorophyll occurs only when Anabaena, a nitrogen‐fixing alga, is an important component of the phytoplankton.The quantity of chlorophyll above the depth zi (= ni) represents ca. 60–80% of the chlorophyll in the photic zone. The value of ni where chlorophyll concentrations are 60 mg/m3 (the maximum concentration at most localities in Lake Minnetonka) is about 100 mg Chl/m2. The usual limit for integral photosynthesis at 20C is therefore 5 g C m‒2 day‒1.
FIELD STUDY AND MATHEMATICAL MODEL OF THE SLACK‐WATER BUILDUP OF A POLLUTANT IN A TIDAL RIVER1
Authors: Grenney William J. , Bella David A. 
Published: March 2010

The accumulation of a pollutant in the vicinity of an outfall during slack‐water periods in a tidal river was studied through a field investigation and a mathematical model.A diffuser was installed across the main channel of the Yaquina River about 35 km from the mouth at Newport, Oregon. Rhodamine‐B was injected at a constant rate for 10 hr and over 400 water samples were taken. The data indicate a significant buildup during periods of slack water.A one‐dimensional, time dependent, finite‐difference model developed for the field study simulated average trends reasonably well, but calculated peak values were consistently lower than field observations. Concentration profiles from the model were sensitive to the dispersion coefficient and the grid parameters when large concentration gradients were present.
OCCURRENCE AND TYPES OF THIOBACILLUS‐LIKE BACTERIA IN THE SEA1
Authors: Tuttle Jon H. , Jannasch Holger W. 
Published: March 2010

Offshore waters and sediments of the Atlantic Ocean and the Black Sea and inshore waters near Woods Hole, Massachusetts, were examined for bacteria resembling Thiobacillus sp., and 136 isolates were obtained by enrichment culture with thiosulfate or elemental sulfur as the energy source. Enrichments for iron‐oxidizing thiobacilli were unsuccessful.Under chemolithotrophic growth conditions, only 19% of the isolates oxidized more than 5% of the thiosulfate supplied in mineral medium, with an increase, moderate decrease, or no change in the pH of the medium. Strains that decreased the pH were proportionately most abundant in inshore water. Thirty‐five percent of the isolates could be cultured on sulfide substrate with a greater yield than on thiosulfate.Seventy‐four percent of the isolates could grow anoxically in thiosulfate mineral medium containing nitrate as the terminal acceptor; only 3 of these produced gas from nitrate. About 95% of all isolates could be grown on organic media. Heterotrophically grown cultures could easily be grown on thiosulfate mineral medium when transferred from organic medium. Apparently the “typical” obligately chemoautotrophic thiobacilli are rare in the marine environment and biological oxidation of reduced sulfur compounds in open ocean areas is largely carried out by facultatively autotrophic bacteria.
AEROBIC DECOMPOSITION OF SEDIMENT AND DETRITUS AS A FUNCTION OF PARTICLE SURFACE AREA AND ORGANIC CONTENT
Authors: Hargrave Barry T. 
Published: March 2010

Oxygen uptake by microbial populations on mud, sand, and various types of detritus was measured in short‐term experiments in aerated water at 20C. Sample size had no effect on oxygen consumption per unit weight, but stirring increased uptake. A 2% Formalin solution completely stopped biological uptake of oxygen by microorganisms on sand and detritus; lake muds showed various degrees of chemical uptake of oxygen.Microorganisms on dead Phragmites leaves consumed oxygen at an increasing rate during the first few days of decomposition, followed by a decline to a rate comparable to uptake by freshly collected detritus. Limnaea feces initially consumed oxygen three times more rapidly than detritus, but after 5 days the rates were equal.Detritus consumed up to three orders of magnitude more oxygen per dry weight than sand; uptake rates were inversely related to particle diameter. The logarithm of oxygen uptake was directly related to the logarithm of particle organic content. Particulate oxygen uptake in this and previous studies fell between 0.1 and 10 mg O2 (g organic matter)−1 hr−1, a rate inversely related to particle diameter. Oxygen uptake per unit weight by particles of ashed mud and sand exposed for 24 hr to decomposing detritus in a nutrient solution and transferred to fresh solution was inversely related to particle size and similar to rates measured with freshly collected samples. On an areal basis all particles consumed between 0.01 and 1.0 × 10−3 mg O2 cm−1 hr−1.The negative linear correlation on logarithmic axes of surface area, organic carbon and nitrogen and bacterial plate counts with sediment particle size is similar to that observed for measures of oxygen uptake. Bacteria cover only a few percent of particle surfaces. This may result in the narrow range of measures of microbial community respiration on an areal basis.
DETERMINATION OF VITAMIN B12, THIAMINE, AND BIOTIN IN LAKE TAHOE WATERS USING MODIFIED MARINE BIOASSAY TECHNIQUES1
Authors: CARLUCCI A. F. , BOWES PEGGY M. 
Published: March 2010

Seawater bioassays for dissolved vitamin B12, thiamine, and biotin have been modified for freshwater samples. The assay algae are: Cyclotella nana; thiamine, Monochrysis lutheri; and biotin, Amphidinium carterae. The lowest detectable levels of dissolved vitamins are: B12, 0.1 ng/liter; thiamine, 4 ng /liter; and biotin, 0.4 ng/liter.Summer and winter samples in a water column near the center of Lake Tahoe were assayed using this method, and, with one exception, vitamins were found only in the euphotic zone.
OXYGEN DEFICIENT CONDITIONS AND NITRATE REDUCTION IN THE EASTERN TROPICAL NORTH PACIFIC OCEAN1
Authors: Cline Joel D. , Richards Francis A. 
Published: March 2010

Oxygen concentrations in the oxygen‐minimum zone of the eastern tropical North Pacific Ocean are at least an order of magnitude lower than previously reported. Concentrations of less than 1µg‐atom/liter are common throughout the region from below the pycnocline to depths of several hundred meters.In these nearly anoxic waters, nitrate appears to be reduced to nitrite and free nitrogen. Nitrate deficits, derived from material balance calculations, suggest that up to 13–14 µg‐atoms/liter of nitrate‐nitrogen have been so reduced. This is 40–50% of the nitrate normally present in this depth interval. Secondary nitrite concentrations rarely exceed 1.5 µg‐atoms/liter and are generally associated with oxygen concentrations of less than 2 µg‐atoms/liter. Ammonia concentrations appear to be slightly lower in the region of denitrification, probably because of bacterial assimilation.If the nitrate reduction rate observed in Darwin Bay in the Galapagos Islands were to apply as a rate of denitrification in the entire oxygen‐minimum zone in the eastern tropical North Pacific, the annual loss of 920 × 1012 g of combined nitrogen could be expected. However, considerations of environmental differences suggest that a figure somewhat less than a quarter of this amount is more probable.
A Simple Engineering Estimate of the Fatigue Notch Factor of Arbitrary Stress Concentrators
Authors: Gaenser Hans‐Peter , Javidi Ataollah 
Published: March 2010

AbstractIn fatigue life estimates, the fatigue stress endured at the hot spot is usually higher than what is predicted by the elastic stress concentration factor. Recently, Neuber's and Novozhilov's approaches of introducing an effective stress by averaging the actual stress field over a characteristic microstructural length have experienced a reappraisal. The present contribution aims at complementing these recent proposals by a mathematically simple engineering assessment of arbitrarily shaped notches, resulting in a closed‐form expression for the fatigue notch factor. The limits of validity of the solution are discussed.
Interplay of Properties and Functions upon Introduction of Mesoporosity in ITQ‐4 Zeolite
Authors: Verboekend Danny , Groen Johan C. , Pérez‐Ramírez Javier 
Published: March 2010

AbstractThe introduction of mesoporosity in zeolites is often directly coupled to changes in their overall catalytic performance without the detailed assessment of other key functions required for the rational design of the catalytic process such as accessibility, adsorption, and transport. This study presents an integrated approach to study property–function relationships in hierarchical zeolites. Accordingly, desilication of the 1D ITQ‐4 zeolite in alkaline medium is applied to develop different degrees of mesoporosity. Along with porosity modification, significant changes in composition, structure, and acidity occur. Relationships are established between the physicochemical properties of the zeolites and their characteristics in the adsorption and elution of light hydrocarbons (C2 to C5, alkanes and alkenes) as well as in the catalytic activity in low‐density polyethylene (LDPE) pyrolysis. The recently introduced hierarchy factor can appropriately relate porosity changes to catalytic performance.
Growth and Transfer of Monolithic Horizontal ZnO Nanowire Superstructures onto Flexible Substrates
Authors: Xu Sheng , Shen Yue , Ding Yong , Wang Zhong Lin 
Published: March 2010

AbstractA method of fabricating horizontally aligned ZnO nanowire (NW) arrays with full control over the width and length is demonstrated. A cross‐sectional view of the NWs by transmission electron microscopy shows a “mushroom‐like” structure. Novel monolithic multisegment superstructures are fabricated by making use of the lateral overgrowth. Ultralong horizontal ZnO NWs of an aspect ratio on the order of ten thousand are also demonstrated. These horizontal NWs are lifted off and transferred onto a flexible polymer substrate, which may have many great applications in horizontal ZnO NW‐based nanosensor arrays, light‐emitting diodes, optical gratings, integrated circuit interconnects, and high‐output‐power alternating‐current nanogenerators.
Hyperferritinemia and iron overload in type 1 Gaucher disease
Authors: Stein Philip , Yu Hannah , Jain Dhanpat , Mistry Pramod K. 
Published: March 2010

AbstractHyperferritinemia occurs in Gaucher disease but its clinical spectrum or its association with systemic iron overload and HFE mutations are not known. In 114 patients with Type 1 Gaucher disease, we determined serum ferritin, transferrin saturation and HFE genotype. The results were correlated with the extent of hepatosplenomegaly, overall Gaucher disease severity score index, and response to enzyme replacement therapy. In a subset of patients with radiological and/or laboratory evidence of systemic iron overload, liver biopsy was performed. There was a mean 3.7‐fold elevation of serum ferritin over the upper limit of normal (ULN). Prior splenectomy was associated with most severe hyperferritinemia compared to patients with intact spleen (6.53 × ULN vs. 2.69 × ULN, P = 0.003). HFE genotyping revealed two patients homozygous for H63D mutation and 30% of patients heterozygote carriers of H63D mutation; no patients harbored C282Y mutation; there was no correlation of ferritin with HFE genotype. Ferritin level correlated with liver volume (Pearson correlation coefficient = 0.254, P = 0.035) and it was negatively correlated with hemoglobin (r = −0.315, P = 0.004); there was no relationship with other indicators of Gaucher disease activity. Enzyme replacement therapy (ERT) resulted in amelioration of hyperferritinemia: 707 ± 898 ng/ml vs. 301 ± 310 ng/ml (P = 0.001), transferrin saturation remained normal. Three patients were suspected of clinical iron overload, confirmed on liver biopsy. Iron accumulation was variably noted in hepatocytes and Kupffer cells. There is a high prevalence of hyperferritinemia in Type 1 Gaucher disease that is associated with indicators of disease severity, reversed by ERT and is not related to HFE mutations. Am. J. Hematol. 2010. © 2010 Wiley‐Liss, Inc.
The longitudinal relationship between the use of ergonomic measures and the incidence of low back complaints
Authors: van der Molen Henk F. , Frings‐Dresen Monique H.W. , Sluiter Judith K. 
Published: March 2010

AbstractBackgroundThe aim of this prospective study was to evaluate the primary preventive effect of the use of ergonomic measures on low back complaints among construction workers.MethodsAn initial questionnaire was sent to a cohort of bricklayers, carpenters, and pavers in 2000. Workers who reported no musculoskeletal complaints were selected (n = 539) and divided into groups that either used or did not use ergonomic measures. The incidence of low back complaints among members of the two groups was re‐assessed with a follow‐up questionnaire administered in 2005.ResultsA total of 12.4% of the construction workers reported regular use of ergonomic measures at baseline and during follow‐up. The 4.5‐year incidence of regular or sustained low back complaints was 17.3%. Frequent use of ergonomic measures was associated with a 15% (RR = 0.85; 95% confidence interval = 0.46–1.55) reduced risk of reporting regular or sustained low back complaints among construction workers after a 4.5‐year period.ConclusionsThis study did not find a statistically significant primary preventive effect of the use of ergonomic measures on low back complaints. Sustained use of effective ergonomic measures among a large group of young construction workers is necessary to provide possible evidence for a significant and relevant primary preventive effect of the use of ergonomic measures on low back complaints in the long term. Am. J. Ind. Med. 53: 635–640, 2010. © 2010 Wiley‐Liss, Inc.
Psychosocial work factors and shoulder pain in hotel room cleaners
Authors: Burgel Barbara J. , White Mary C. , Gillen Marion , Krause Niklas 
Published: March 2010

AbstractBackgroundHotel room cleaners have physically demanding jobs that place them at high risk for shoulder pain. Psychosocial work factors may also play a role in shoulder pain, but their independent role has not been studied in this group.MethodsSeventy‐four percent (941 of 1,276) of hotel room cleaners from five Las Vegas hotels completed a 29‐page survey assessing health status, working conditions, and psychosocial work factors. For this study, 493 of the 941 (52%) with complete data for 21 variables were included in multivariate logistic regression analyses.ResultsFifty‐six percent reported shoulder pain in the prior four weeks. Room cleaners with effort–reward imbalance (ERI) were three times as likely to report shoulder pain (OR 2.99, 95% CI 1.95–4.59, P = 0.000) even after adjustment for physical workload and other factors. After adjustment for physical workload, job strain and iso‐strain were not significantly associated with shoulder pain.ConclusionsERI is independently associated with shoulder pain in hotel room cleaners even after adjustment for physical workload and other risk factors. Am. J. Ind. Med. 53:743–756, 2010. © 2010 Wiley‐Liss, Inc.
Ovarian reserve tests and their utility in predicting response to controlled ovarian stimulation in rhesus monkeys
Authors: Wu Julie M. , Takahashi Diana L. , Ingram Donald K. , Mattison Julie A. , Roth George , Ottinger Mary Ann , Zelinski Mary B. 
Published: March 2010

AbstractControlled ovarian stimulation (COS) is an alternative to natural breeding in nonhuman primates; however, these protocols are costly with no guarantee of success. Toward the objective of predicting COS outcome in rhesus monkeys, this study evaluated three clinically used ovarian reserve tests (ORTs): day 3 (d3) follicle‐stimulating hormone (FSH) with d3 inhibin B (INHB), the clomiphene citrate challenge test (CCCT), and the exogenous FSH Ovarian Reserve Test. A COS was also performed and response was classified as either successful (COS+) or unsuccessful (COS−) and retrospectively compared with ORT predictions. FSH and INHB were assessed for best hormonal index in conjunction with the aforementioned tests. INHB was consistently more accurate than FSH in all the ORTs used. Overall, a modified version of the CCCT using INHB values yielded the best percentage of correct predictions. This is the first report of ORT evaluation in rhesus monkeys and may provide a useful diagnostic test before costly follicle stimulations, as well as predicting the onset of menopause. Am. J. Primatol. 72:672–680, 2010. © 2010 Wiley‐Liss, Inc.
Effect of polyethylene glycol on the performance of ultrahigh‐molecular‐weight polyethylene membranes
Authors: Li Nana , Xiao Changfa , Zhang Zhiying 
Published: March 2010

AbstractPorous, flat membranes of ultrahigh‐molecular‐weight polyethylene (UHMWPE) were prepared by thermally induced phase separation, with mineral oil as a diluent and poly(ethylene glycol) with a weight‐average molecular weight of 20,000 (PEG20000) as an additive. Through the control of the rheological behavior, crystallite size, and pore structure, the influential factors, including the diluent, poly(ethylene glycol) (PEG) content, and cooling rate, were investigated. The results suggested that PEG could decrease the viscosity of UHMWPE/diluent apparently. The crystal density decreased when mineral oil was added, which made the melting point and crystallinity of UHMWPE lower. The crystallization rate and crystallinity also increased with the addition of PEG. However, the addition of excess PEG restrained crystal growth. PEG20000 in membranes could be extracted absolutely through the soaking of the membranes with fresh water for 7 days. With increasing PEG content, both porosity and pure water flux first increased and then decreased, reaching a maximum at a PEG mass fraction of 10%. The cooling rate had a direct effect the crystal structure. A slow cooling rate was good for crystal growth and diluent integration. Therefore, the pure water flux increased along with the temperature of the cooling medium, whereas porosity first increased and then decreased, reaching a maximum at 40°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
A simple method for forecast of cooling time of high‐density polyethylene during gas‐assisted injection molding
Authors: Liang Shui‐Po , Yang Bin , Fu Xiao‐Rong , Yang Wei , Sun Nan , Hu Sheng , Yang Ming‐Bo 
Published: March 2010

AbstractGas‐assisted injection molding (GAIM) is an innovative plastic processing technology, which was developed from the conventional injection molding, and has currently found wide industrial applications. About 70% of the whole gas‐assisted injection molding cycle is actually occupied by the cooling stage. The quality and production efficiency of molded parts are considerably affected by the cooling stage. Hence, it is necessary to study the solidification behaviors during the cooling stage. In this work, a simple experimental method was designed to simulate the solidification behaviors of high‐density polyethylene during cooling stage of GAIM. The enthalpy transformation approach, coupled with the control‐volume/finite difference techniques, was adopted to deal with the transient heat transfer problems with phase change effects. In situ measurements of the temperature decreases in the cavity were also carried out. Reasonable agreements between the experimental values and the simulated results such as cooling time, cooling rates, and temperature curves were obtained, which proved that this simple experimental method was effective. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Cell Secretion Mediated by Granule‐Associated Vesicle Transport: A Glimpse at Evolution
Authors: Crivellato Enrico , Nico Beatrice , Gallo Valentina Patrizia , Ribatti Domenico 
Published: March 2010

AbstractRegulated secretion allows extrusion of cell products stored in specialized membrane‐bound organelles called secretory granules or secretory vesicles. Regulated secretion provides basic functions in living organisms, and in a phylogenetic perspective, it is recognizable in the most primitive eukaryotic forms. This article is an attempt to trace the evolutionary history of a special type of secretory pattern, which has been referred to as vesicle‐mediated degranulation or piecemeal degranulation (PMD). First described in the early 70s of the last century in inflammatory cells, such as the basophils, mast cells, and eosinophils, this regulated secretory route has subsequently been recognized in endocrine cells, in particular in the chromaffin cells of the adrenal medulla. This vesicle‐mediated degranulation is held to mobilize small and specific aliquots of granule‐associated material for selective paracrine or endocrine transport to the cell exterior. PMD has been identified in many vertebrate classes. By contrast, no data are available for invertebrates. We speculate that this pattern of cell secretion emerged early in phylogenesis, when the first metazoans appeared. In this review article, we will first revise the concept of vesicle‐mediated degranulation in the light of the most recent experimental discoveries and theoretical implications. Then, the distribution of this secretory mode among vertebrates and its molecular basis will be highlighted. Finally, the potential occurrence of PMD in invertebrates, its biological significance from an evolutionary perspective and the future direction of investigations will be briefly sketched. Anat Rec 293:1115–1124, 2010. © 2010 Wiley‐Liss, Inc.
Resolution of the Atropochiral Biminap Ligand and Applications in Asymmetric Catalysis
Authors: Abdellah Ibrahim , Debono Nathalie , Canac Yves , Vendier Laure , Chauvin Remi 
Published: March 2010

AbstractEnantiomeric resolution of the rac‐biminap ligand is achieved through fractional crystallization of four diastereoisomeric palladium complexes involving ortho‐metallated enantiomerically pure (R)‐dimethyl(1‐naphthylethyl)amine as a chiral auxiliary. After decomplexation, the absolute configuration of (R)‐biminap and (S)‐biminap has been unambiguously attributed by single‐crystal X‐ray crystallography, and their stereochemical purity is confirmed by measurement of their optical rotation and by re‐derivatization with the initial resolving chiral complex. Palladium complexes of biminap are shown to efficiently catalyze Tsuji–Trost allylic substitution of 3‐acetoxy‐1,3‐diphenylpropene by sodium dimethyl malonate. In the asymmetric version using the enantiomerically pure (R)‐biminap ligand, significant solvent and anion effects are evident, and an ee up to 90 % is obtained.