bluuebunny/crossref_metadata_2025 huggingface dataset:
In situ ecosystem‐based carbon dioxide perturbation experiments: Design and performance evaluation of a mesocosm facility
Authors: Kim Ja‐Myung , Shin Kyoungsoon , Lee Kitack , Park Byong‐Kwon
Published: April 2011

We describe a mesocosm facility that can be used for in situ CO2 perturbation experiments. The facility consists of a floating raft, nine impermeable cylindrical enclosures (each approximately 2400 L in volume), pCO2 regulation units, and bubble‐mediated seawater mixers. Each enclosure is two‐thirds filled with seawater, and the headspace above is filled with air at a target pCO2 concentration. Each enclosure is capped with a transparent dome that transmits incoming radiation. To produce pCO2 levels higher than the ambient concentration, the mass flow controller in the pCO2 regulation unit delivers varying amounts (10–320 mL min−1) of ultra‐pure CO2 into the gas mixer where it is rapidly mixed with ambient air (approximately 50 L min−1). To produce pCO2 levels lower than the ambient concentration, CO2‐free air and ambient air are mixed in the gas mixer. Prior to daily seawater sampling, approximately 0.5 L min−1 of the target concentration pCO2 air stream is diverted to the seawater mixer for thorough mixing with the seawater in the enclosure, while the major fraction of the target concentration pCO2 air stream continues to flow into the enclosure headspace. A performance evaluation of the mesocosm facility assessed attainment of target pCO2 concentrations in the headspace and enclosure seawater, and the mixing efficiency of the seawater mixer. The results indicate that the facility is suitable for carrying out in situ pCO2 perturbation experiments.
Effects of biofouling on performance of moored data logging acoustic receivers
Authors: Heupel Michelle R. , Reiss Katie L. , Yeiser Beau G. , Simpfendorfer Colin A.
Published: April 2011

Biofouling on scientific equipment deployed in marine and estuarine environments can have implications for equipment performance, and the type and amount of data collected. We examined the effects of biofouling on the performance of data logging acoustic receivers deployed in shallow coastal waters off Florida. Five treatment types of receivers were examined including old and new versions of VR2 (Vemco Ltd) receivers with complete, partial, or no antifouling paint. Receivers were deployed for 2 mo, and acoustic signal detection rates examined. All receivers had some extent of biofouling during the course of the study, and performance was variable among treatment types. Old version receivers did not perform as well as new version receivers in all cases, and significant differences were apparent in detection rate and receiver performance metrics. Reductions in receiver performance over time occurred for most treatments and were likely due to settlement of biofouling organisms including barnacles, annelids, tunicates, and ascidians. Biofouling appeared to affect receiver performance over time and should be taken into account in acoustic telemetry studies.
Determination of photochemically produced carbon dioxide in seawater
Authors: White Emily M. , Kieber David J. , Mopper Kenneth
Published: April 2011

An analytical system was developed to determine photochemically produced carbon dioxide in marine waters. Our system was designed to measure low levels of carbon dioxide by maintaining a closed system to prevent atmospheric contamination during sample preparation, irradiation, and analysis. To detect low levels of photoproduced carbon dioxide in seawater, background dissolved inorganic carbon (DIC) was removed before irradiation. To strip out DIC, samples were acidified to pH 3.0 (converting DIC to carbon dioxide) and bubbled with low carbon dioxide air. The pH was then readjusted back to the original value, and the resulting low‐DIC seawater samples were transferred pneumatically to air‐tight quartz tubes for irradiation. During analysis, samples were pneumatically transferred to a sample loop, injected, and acidified. Carbon dioxide was then stripped out, dried, and carried to a nondispersive infrared carbon dioxide analyzer. Calibration was done with a series of low concentration aqueous carbonate standards (0.05 to 3 µmol L−1). The detection limit, defined as the concentration corresponding to three times the standard deviation of the experimental blank (i.e., DIC‐stripped seawater), was ~60 nmol L−1. Method precision was largely dependent on the agreement between multiple injections from the same tube (< ±2% relative standard deviation [RSD]) and the reproducibility between different tubes (±3% RSD). This method was used to measure carbon dioxide photoproduction in a variety of waters (e.g., estuarine, lake) including the first direct measurements in marine waters.
A microsensor for carbonate ions suitable for microprofiling in freshwater and saline environments
Authors: de Beer Dirk , Bissett Andrew , de Wit Rutger , Jonkers Henk , Köhler‐Rink Stefanie , Nam Hakyun , Kim Byeong Hyo , Eickert Gabriele , Grinstain Mor
Published: April 2011

A novel carbonate microsensor, based on the ion‐selective ionophore N,N,‐dioctyl‐3a,12 a‐bis(4‐trifluoroacetylbenzoxy)‐5β‐cholan‐24‐amide, is presented. The sensor chemistry and filling electrolyte, used previously for macrosensors, was improved for use in microsensors, and a simple calibration procedure was designed. The sensor is highly selective for carbonate, having a similar selectivity as the macrosensor, and is so insensitive to Cl− interference that it can be used in seawater. The ability to measure accurate profiles with the carbonate sensor was verified in agar gels with artificial carbonate gradients. Several environmental applications are presented, including photosynthesis and calcification measurements in freshwater stromatolites (tufas) and foraminifera. Carbonate profiles in illuminated and darkened hypersaline microbial mats were qualitatively as expected and aligned with the oxygen and pH profiles. The dissolved inorganic carbon profiles calculated from local pH and carbonate values, however, did not follow the expected trends, both in the foraminifera and the hypersaline mat. Temporal and spatial heterogeneities make perfect alignment of pH and carbonate profiles, needed for DIC calculations, unrealistic. The calculation of dissolved inorganic carbon microprofiles from pH and carbonate microprofiles is not recommended. The microsensor is highly useful in studies on calcification and decalcification, where direct concentrations of carbonate and calcium ions are needed.
Intracellular pH distribution in foraminifera determined by the fluorescent probe HPTS
Authors: de Nooijer L. J. , Toyofuku T. , Oguri K. , Nomaki H. , Kitazato H.
Published: April 2011

Fossil foraminifera are excellent tools to reconstruct past marine environments since the chemistry of their calcium carbonate reflects many physical and chemical parameters of seawater. However, trace elemental/calcium ratios in foraminiferal calcite vary between species and within specimens, usually deviating from ratios found in inorganically precipitated calcite. Biological control on CaCO3 precipitation is most likely to proceed by modification of the pH at the site of calcification or by removal of Mg2+ from the mother solution. In this study, we show the application of the nontoxic fluorescent probe 8‐hydroxypyrene‐1,3,6‐trisulfonic acid (HPTS) in analyzing foraminiferal intracellular pH. In all analyzed taxa, high‐pH vesicles with a size of 3–5 µm were found in the cell, commonly in higher densities toward the ultimate chamber. Vesicles with the highest pH (≥ 8.5) were found in the miliolid species Quinqueloculina costata: hyaline species displayed vesicles with a pH of 8.0–8.5. These results show the potential of the application of HPTS in providing fundamental insights in foraminiferal control on the pH during calcification and thereby on trace elemental partitioning.
Persulfate chemical wet oxidation method for the determination of particulate phosphorus in comparison with a high‐temperature dry combustion method
Authors: Suzumura Masahiro
Published: April 2011

A persulfate chemical wet oxidation (CWO) method for the determination of particulate phosphorus (PP) was improved and then compared with a conventional high‐temperature dry combustion (HTDC) method. In the improved CWO method, the concentration of the digestion reagent, potassium persulfate, was increased from 0.5% to 3% (w/v); the method exhibited high recoveries of P from various test materials under commonly used autoclave conditions (at 120°C for 30 min). The recoveries of P relative to those of the HTDC method were 102 ± 6.7% from standard organic and inorganic P compounds, and 100 ± 3.8% from natural particulate matter analogues including riverine suspended particulate matter (SPM), sediments, plankton, and geochemical reference materials of rock. However, low recoveries of 14% to 69% were observed for reference samples of clay minerals. Comparison using many samples of estuarine and pelagic SPM showed that the CWO method produced PP values consistent with those obtained by the HTDC method, except for some estuarine samples enriched in inorganic matter. The low recoveries were ascribed to the presence of an inorganic P fraction highly recalcitrant to chemical digestion. The procedural blank was lower for the CWO method than for the HTDC method. The filter blanks showed large variation among the filter materials tested; aluminum oxide membrane filters were shown to contain a considerable amount of P that could cause significant contamination in both methods. Analytical precision was equivalent between the two methods. Considering its simplicity and its less time‐consuming nature, the CWO method presented here is suitable for PP determination in aquatic environments.
Application of cross‐flow filtration for determining the solubility of iron species in open ocean seawater
Authors: Schlosser Christian , Croot Peter L.
Published: April 2011

Measurements of soluble iron species (organic and inorganic) are important for understanding the transport of iron within the ocean and its bioavailability. Recent developments in ultrafiltration equipment and analytical detection techniques for low level Fe determination has turned the spotlight on obtaining data on soluble iron species. However there have, until now, been few studies that have characterized the performance of an ultrafiltration system with respect to well described soluble iron complexes. In the present work, we describe a methodological study characterizing the behavior of soluble and colloidal iron species in seawater by combining a cross‐flow ultrafiltration system (Vivaflow 50™) with a radioisotope (55Fe). During this study, we were able to maintain excellent mass balances by including all components: not only the solution phases (retentate and permeate) but wall‐adsorbed and filter‐adsorbed iron, which were recovered by an acid‐rinsing step. Wall and filter adsorption were unavoidable when solutions were saturated with respect to Fe′. However in undersaturated solutions, such as with an excess of desferrioxamine B, wall and filter adsorption were minimized, indicating that these effects should be slight for natural samples where iron‐binding ligands are in excess. Our results have important implications for the use of ultrafiltration membranes for open ocean iron biogeochemical studies.
Novel temperature gradient incubator to study the effects of temperature on motile aquatic organisms
Authors: Heinze Adam W. , Sanders Robert W.
Published: April 2011

Water temperature influences planktonic communities via biological (e.g., metabolic) and abiotic means. Investigating direct temperature effects in nature is confounded by multiple factors that may covary with temperature at various depths, especially during periods of seasonal stratification. Dissolved oxygen, nutrient availability, water density, and irradiance all change with depth in thermally stratified systems. We have designed a temperature gradient incubator that creates a range of temperature within a continuous 1.65‐m transparent column. This novel instrument allows investigation of how motile plankton are distributed across a controlled range of temperatures, which, in the configuration presented here, is a change of 8°C within the vertical column. The temperature gradient incubator allows elimination of confounding variables to test what portion of vertical migration within the water column is due strictly to changes in temperature. With simple reconfiguration of the light sources, interaction of temperature and irradiance effects on plankton can also be evaluated.
Robolimpets: measuring intertidal body temperatures using biomimetic loggers
Authors: Lima Fernando P. , Wethey David S.
Published: April 2011

This work introduces new biomimetic devices to record body temperatures of sessile intertidal animals. These waterproof devices, built around dissected circuit boards from Maxim DS1922 Thermochron iButtons, are demonstrated using intertidal limpets (Tectura persona). Data were validated by a field experiment carried out at Friday Harbor, Washington, USA. These loggers, named robolimpets, can easily be deployed to autonomously and accurately measure temperatures for long periods of time. Given that they mimic the visual aspect of real animals, they have the advantage of being inconspicuous in the intertidal environment. Their measurements not only match the temperature trajectories, but also the warming and cooling rates and daily temperature maxima and minima of live limpets. Robolimpets provide valuable data on the body temperatures experienced by intertidal animals.
Influence of bubbles and sand on chlorophyll‐a fluorescence measurements in the surfzone
Authors: Omand Melissa M. , Feddersen Falk , Clark David B. , Franks Peter J.S. , Leichter James J. , Guza R.T.
Published: April 2011

Continuous chlorophyll‐a (Chla) measurements in the surfzone (region of wave‐breaking adjacent to the shoreline) would increase understanding of harmful algal blooms, food supply for intertidal invertebrates and fishes, and the fate of terrestrial runoff pollution. Optical measurements of Chla fluorescence in the surfzone are affected by bubbles and suspended sand. Here, errors in surfzone Chla fluorescence measurements (using WET Labs ECO Triplet fluorometers) are estimated by comparing observed (Chlaraw) with known (Chlatrue) Chla concentrations in laboratory tests with controlled amounts of bubbles and suspended sand (characterized with concurrently measured optical turbidity, τ). For both bubbles and sand, Chlaraw and τ are linearly correlated, and the regression line slope depends on Chlatrue. When Chlatrue is low, Chlaraw is biased high, and when Chlatrue is high, Chlaraw is biased low. Fluorometers were also deployed in a natural surfzone, and for the limited range of field Chla observed, the field and laboratory τ‐Chla relationships were largely consistent. Mechanisms responsible for these biases are proposed, and correction procedures using the observed τ‐Chla relationship are developed and applied to surfzone Chlaraw observations. For the moderate Chlatrue concentrations (2–4 µg L−1) encountered, errors in hourly mean and instantaneous Chlaraw are less than 5% and 15%, respectively. Larger errors are expected for Chlatrue outside this range. Although further testing is needed, the results suggest that in situ, optical Chlaraw from other turbid environments (e.g., estuaries, bays) should also be interpreted cautiously.
Mollusc shell periostracum as an alternative to tissue in isotopic studies
Authors: Delong Michael D. , Thorp James H.
Published: April 2011

Recent studies have used carbon and nitrogen stable isotope ratios of preserved soft tissues to examine historical changes in trophic patterns of aquatic ecosystems. A limitation in this application is the difficulty in finding specimens for primary consumers, which can act as a surrogate for basal food sources in determining the trophic status of higher consumers. The availability of preserved soft tissues of invertebrate primary consumers is often limited in museum and archival collections; hard parts such as mollusc shells, however, are often abundant because of their ease of storage. We used stable isotope ratios of carbon and nitrogen to determine if there was a relationship between the isotopic composition of the periostracum of the shell and soft body tissue of freshwater molluscs. We found a significant correlation between (1) periostracum and tissue of freshly collected freshwater mussels, (2) ethanol‐preserved adductor muscle tissue and dry‐preserved mussels from museum collections, and (3) ethanol‐preserved tissue and periostracum of gastropods from museum collections. The predictability of these relationships enhances the capacity to track changes in trophic complexity over time and responses of food webs to natural and anthropogenic environmental perturbations.
Advances in solid phase extraction of the cyanobacterial toxin cylindrospermopsin
Authors: Wormer Lars , Carrasco David , Cirés Samuel , Quesada Antonio
Published: April 2011

Unlike other cyanotoxins, cylindrospermopsin (CYN) is often found in high concentrations in the extracellular fraction, possibly due to a higher release from the producing cells and a limited degradation once liberated. This fact demands effective recovery methods from environmental samples to guarantee a proper quantification. A reliable and simple solid phase extraction (SPE) method was obtained by the sole use of graphitized carbon cartridges and by paying special attention to both the selection of the most suitable solvent and the need of sample preparation prior to SPE. An acidified combination of dichloromethane and methanol not only showed best recoveries, but also allowed drastic reduction to the elution volumes needed with complete recovery being achieved in only 8 mL. Acidification of the sample and addition of sodium chloride are suggested as valuable improvements to the SPE method and turn out to be essential for correct and robust recovery of CYN in environmental samples of great diversity in terms of pH, DOC, and conductivity. Excellent behavior of the proposed method over a wide range of CYN loadings, applied sample volumes, and DOC loadings was also confirmed.
Three‐dimensional laser scanning as an efficient tool for coral surface area measurements
Authors: Raz‐Bahat Michal , Faibish Hanny , Mass Tali , Rinkevich Baruch
Published: April 2011

In scleractinian corals, as in many sessile colonial organisms, surface area serves as the prime descriptor for standardization and quantification of physiological and biochemical parameters. The complexity of colonial architecture, however, complicates measurement of surface area, yielding less than satisfactory results for the established methodologies. Here, we used a 3D desktop laser scanner for accurate measurements of skeletal surface area of various coral fragments. The original 127‐µm accuracy of the scanner was tested on modules with increasing complexity. It showed a linear (R2 = 0.912), but relatively small, increase of up to 9.67% accuracy error in complex modules. The scanner's maximum credibility error in repeated measurements was only 1.67%, representing an average error of 0.87 ± 0.66%. We compared the scanner's measured surface area results with those of four established methods: wax coating, foil paper wrapping, methylene blue dipping, and caliper measurements. In all methods, credibility and accuracy errors pointed to the superiority of the new method. Laser scanning is rapid (minimum 10 min per scan), efficient, easy to operate, and economically feasible as a common bench tool.
Real‐time detection of reactive oxygen species generation by marine phytoplankton using flow injection—chemiluminescence
Authors: Milne Angela , Davey Margaret S. , Worsfold Paul J. , Achterberg Eric P. , Taylor Alison R.
Published: April 2011

Little is known about the biological production of reactive oxygen species (ROS) such as H2O2 and O2− in the surface waters of the oceans. This article describes two flow injection—chemiluminescence methods to measure H2O2 and O2− production by marine diatoms. These methods each incorporated a polycarbonate filter unit in which live cells were immobilized, followed by downstream determination of H2O2 and O2− in the cell filtrate. The sample analysis rate was ~1 min−1 for H2O2 and continuous for O2− during assays with diatom cells. The respective detection limits for each system were 1.9 nM (H2O2) and 1.6 nM (O2−). An initial examination of the effect of changing light intensity showed that a rapid light‐induced production of both O2− and H2O2 by T. weissflogii cells could be readily detected. Moreover, this production was proportional to the biomass present on the flushed filter. These methods enable the monitoring of real‐time fluctuations of biological ROS production in response to changing environmental conditions, and therefore facilitate analysis of the biotic component of ROS production and the subsequent impacts on chemical speciation of nutrients and trace metals in aquatic ecosystems.
Comparison of CHN analysis and Hach acid digestion to quantify total nitrogen in marine organisms
Authors: Barbarino Elisabete , Lourenço Sergio O.
Published: April 2011

The quantification of total nitrogen in biological samples has wide applications in marine sciences. Different methods are currently used to quantify nitrogen content, but their accuracies have not been extensively tested with samples of marine origin. In this study, we compared results for total nitrogen analysis generated by the Hach method, a relatively new and low‐cost technique, with CHN elemental analysis, a widely accepted and costly technique. Sixty aquatic organisms were tested covering substantial biological diversity, including algae, invertebrates, fishes, mangrove plants, salt marsh plants, and seagrasses. Two pure protein standards (bovine serum albumin and bovine milk casein) were also tested. All materials were tested using freeze‐dried samples. Fishes showed the highest concentrations of nitrogen, with values always higher than 14%, whereas leaves of mangrove plants showed the poorest N content among all species (<2.0%). In general, animals showed higher values for total nitrogen than algae and spermatophytes. Results obtained with CHN analysis and the Hach method were compared for each species based on triplicate analyses for each method. Comparisons for each species showed no statistical differences between the techniques, which yielded virtually identical nitrogen measurements. In addition, results obtained with both CHN analysis and the Hach method for the two pure protein standards were similar to data provided by the manufacturer. The set of results indicates that the Hach method is suitable for nitrogen analysis of marine organisms and should be considered as an inexpensive and accurate alternative for nitrogen quantification.
Sequential injection trace determination of iron in natural waters using a long‐pathlength liquid core waveguide and different spectrophotometric chemistries
Authors: Páscoa Ricardo N.M.J. , Tóth Ildikó V. , Rangel António O.S.S.
Published: April 2011

We developed a sequential injection analysis (SIA) method for the determination of iron in coastal, ground, and surface fresh waters using two different reagents (ferrozine and 1,10‐phenathroline). The methodology uses a double‐line SIA system to improve mixing conditions between sample and reagent solutions. A liquid wave‐guide capillary cell (LWCC) with 1.0 m pathlength, 550 µm i.d., and 250 µL internal volume was used to enhance the sensitivity of the determination. The detection limits for the ferrozine and 1,10‐phenanthroline reagent were 0.15 and 0.35 µg L−1, respectively. The system provides a linear response up to 20 µg L−1 and has a high throughput rate (41 h−1), low reagent consumption, and also low effluent production for both reagents. The developed method was applied to natural waters (river, well, ground, potable, and sea waters) and one reference water sample.
Extraction of interannual trends in seasonal events for ecological time series
Authors: Almeida Elizabete , Dowd Michael , Flemming Joanna Mills , Li William K.W.
Published: April 2011

The statistical analysis of environmental monitoring data is an important issue in detecting year‐to‐year changes in levels and timings of important ecological events. In many cases, this trend detection must explicitly view interannual changes from the context of an evolving seasonal cycle. This study analyses weekly sampling data from a long‐term ocean monitoring program near Halifax, Nova Scotia, Canada. A state space model of evolving seasonality with a quadratic trend is fit to these time series to extract the signal from the noisy and irregularly sampled data. The procedure uses Kalman filter innovations to estimate model parameters. A fixed interval smoother is then applied to estimate the system state. The resultant state estimates are subjected to a trend analysis carried out with respect to key ecological events: the level and timing of the peak, trough, spring, and fall abundances. These events are identified using derivative information, followed by a regression‐based trend analysis. The analysis found a number of significant linear trends in the biogeochemical variables considered. More generally, the approach used here is suitable for use with monitoring data exhibiting a unimodal seasonal signal with noise and missing values.
Shotgun proteomics: Tools for analysis of marine particulate proteins
Authors: Dong Hong‐Po , Wang Da‐Zhi , Dai Minhan , Chan Leo Lai , Hong Hua‐Sheng
Published: April 2011

This study sought a high resolution and high‐throughput method to identify and characterize proteins from marine particulate organic matter (POM) using proteomic approaches. The results showed that only a limited number of discrete protein spots were distinguished using two‐dimensional electrophoresis (2‐DE). Most protein spots were faint and small in 2‐DE gels, with a heavy unresolved smeared staining background, indicating 2‐DE was not a good high resolution method to separate particulate proteins for identification and characterization. The shotgun proteomic approach combining one‐dimensional electrophoresis and capillary liquid chromatography‐ tandem mass spectrometry as well as the NCBI protein database search was successfully applied to identify and characterize particulate proteins. Using this approach, 737 proteins matching one or more peptides were detected in a POM sample collected from the 41 m water layer in the basin area of the western South China Sea. Of these, 184 were identified as high‐confidence proteins matching two or more peptides, including photosynthetic proteins, transporters, molecular chaperones, and porins. In addition to these proteins with known functions, a significant number of novel proteins (accounting for ~30% of the proteins identified) were also detected. The identification of a large number of high‐confidence proteins in the POM sample demonstrated that the shotgun proteomic approach is reliable and feasible for the study of particulate proteins and will provide a powerful tool to comprehensively investigate the nature and dynamics of POM in the ocean.
Three‐dimensional odorant concentration measurements around actively tracking blue crabs
Authors: Dickman Brian D. , Webster Donald R. , Page Jennifer L. , Weissburg Marc J.
Published: April 2011

Blue crabs (Callinectes sapidus) and other aquatic organisms locate food and mates by tracking turbulent odorant plumes. The odorant concentration fluctuates unpredictably due to turbulent transport, and many characteristics of the fluctuation pattern have been hypothesized as useful cues for orienting to the odorant source. To make a direct linkage between tracking behavior and odorant signal properties, we developed a laserinduced fluorescence measurement system to quantify the instantaneous three‐dimensional (3D) concentration field surrounding actively tracking blue crabs. The data suggest a connection between upstream walking speed and bursts of odorant concentration arriving at the antennule chemosensors, which are located near the mouth region. Specifically, we note rapid upstream walking speed when high concentration bursts arrive at the antennules location and a decrease in upstream walking speed in the absence of odorant filaments near the antennules. Additionally, we note transverse crab movements in apparent response to the transverse distribution of the odorant concentration field. Specifically, asymmetry of the odorant concentration distribution at the elevation of the leg chemosensors is associated with subsequent crab position adjustments in the transverse direction. The methods described here allow for powerful and direct tests of chemosensory navigation strategies in blue crabs, as well as other macroscopic aquatic animals.
Which peer-reviewed journals publish the most on diabetes?
Authors: Neilson Christine J , Neilson Daniel D
Published: April 2011

Objectives – A list of the major peer-reviewed journals that publish on diabetes has not been published to date. This article briefly describes a project to compile a list of peer-reviewed English-language journals that publish the most on the topic of diabetes. Methods – We used the PubMed and CINAHL Plus databases to identify relevant articles published in English between 2003 and 2007. The number of citations for each journal was totalled, and the peer-reviewed status of the journals topping the list was determined. Results – We present a list of 100 peer-reviewed journals relevant to the topic of diabetes that is based on a larger list compiled for the Canadian Diabetes Educator Certification Board. The list includes a mix of general medicine journals and specialty journals. Discussion – A number of technical setbacks were overcome to determine which scholarly journals publish the most articles of potential interest to health practitioners with an interest in diabetes. This list can inform the current awareness activities of librarians and health practitioners alike, and may be useful from the perspective of collection development.
Clinical significance of annexin A2 downregulation in oral squamous cell carcinoma
Authors: Rodrigo Juan P. , Lequerica–Fernández Paloma , Rosado Pablo , Allonca Eva , García–Pedrero Juana M. , de Vicente Juan C.
Published: April 2011

Background

The purpose of this study was to determine the expression of Annexin A2 (ANXA2) in normal oral epithelium and in oral carcinomas to correlate these findings with prognostically relevant variables.

Methods

ANXA2 expression in normal oral mucosa and in 106 oral squamous cell carcinomas was examined by immunohistochemistry.

Results

ANXA2 expression was detected in basal and suprabasal cell layers of normal epithelium, and immunostaining was preferentially membrane‐localized. ANXA2 expression was significantly correlated with the histopathological grade, tumor size, and recurrence, but ANXA2 expression was not an independent prognostic factor.

Conclusion

The reduction of ANXA2 expression in poorly differentiated tumors is expected to result in a loss of function aimed at the coordination of membrane signaling enzyme complexes. The consequences may manifest as an alteration of epithelial tissue growth and remodeling which eventually exert an influence on tumor progression and metastasis © 2011 Wiley Periodicals, Inc. Head Neck, 2011
Surface‐Active Properties and Antimicrobial Study of Conventional Cationic and Synthesized Symmetrical Gemini Surfactants
Authors: Kuperkar Ketan , Modi Jigisha , Patel Keshav
Published: April 2011

Symmetrical gemini surfactants of cationic series α,ω‐alkanediyl bis (dimethyl ammonium bromide) commonly referred as “m–s–m” have been synthesized. Spectral analysis was performed to confirm compound structures and purity. Conductivity and surface tension measurements provide better understanding of the micellization process. Their self‐assembly behavior in aqueous solution is also discussed in detail. The antimicrobial efficacy was measured by bacterial and fungal growth inhibition expressed as minimal inhibitory concentration values against five strains of a representative group of microorganisms viz. Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumonia, Salmonella paratyphi B and Aspergillus niger. All of the synthesized surfactants showed antimicrobial activity against them, but at different levels depending on their structures. The surfactants possessing longer alkyl chains (more hydrophobic environment) demonstrated better antimicrobial functionality. The antimicrobial potency was found to be dependent on the representative target microorganism (Gram‐positive bacteria > fungi > Gram‐negative bacteria), as well as on the ionic nature of the surfactant (cationic), alkyl chain length (m = 12, 16) and spacer length (s = 2, 4, 6) of the synthesized compounds. Gemini surfactants such as 12‐2‐12 and 12‐4‐12 were found to be weakly active whereas 16‐2‐16 and 16‐4‐16 compounds proved to be the most potent antimicrobial surface‐active agents among the synthesized gemini homologues.
Left ventricular apical diseases
Authors: Cisneros Silvia , Duarte Ricardo , Fernandez-Perez Gabriel C. , Castellon Daniel , Calatayud Julia , Lecumberri Iñigo , Larrazabal Eneritz , Ruiz Berta Irene
Published: April 2011

There are many disorders that may involve the left ventricular (LV) apex; however, they are sometimes difficult to differentiate. In this setting cardiac imaging methods can provide the clue to obtaining the diagnosis. The purpose of this review is to illustrate the spectrum of diseases that most frequently affect the apex of the LV including Tako-Tsubo cardiomyopathy, LV aneurysms and pseudoaneurysms, apical diverticula, apical ventricular remodelling, apical hypertrophic cardiomyopathy, LV non-compaction, arrhythmogenic right ventricular dysplasia with LV involvement and LV false tendons, with an emphasis on the diagnostic criteria and imaging features.
The prevalence of circumportal pancreas as shown by multidetector-row computed tomography
Authors: Ishigami Kousei , Tajima Tsuyoshi , Nishie Akihiro , Asayama Yoshiki , Kakihara Daisuke , Nakayama Tomohiro , Shirabe Ken , Taketomi Akinobu , Nakamura Masafumi , Takahata Shunichi , Ito Tetsuhide , Honda Hiroshi
Published: April 2011

Objective

To evaluate the prevalence of circumportal pancreas (CP) and any coexisting anomaly. In addition, three cases of surgically confirmed CP are presented.

Methods

The study group consisted of 317 consecutive potential liver transplant donor candidates who had undergone thin-section MDCT studies for the evaluation of vascular anatomy. MDCT images were retrospectively reviewed to assess the presence or absence of CP. If CP was present, the transverse diameter of the aberrant pancreatic tissue was measured on axial images, and the course of the main pancreatic duct (MPD) was classified into ante-portal (normal) or retro-portal. In addition, the prevalence of variant hepatic arterial anatomy was compared between cases with and without CP.

Results

Eight of 317 liver transplant donor candidates (2.5%) were found to have CP at CT. The transverse diameter of the aberrant pancreatic tissue ranged from 5 to 18 mm (mean ± SD: 10 ± 4 mm). One of eight (12.5%) showed the MPD to be retro-portal. A variant hepatic artery was noted in two of the of eight (25%) patients, which was similar to the finding for those without CP [72 out of 309 (23%)].

Conclusion

The prevalence of circumportal pancreas was 2.5%.
Destabilization of Conjugated Systems of α-Dicarbonyls and of Cyanogen
Authors: Zavitsas Andreas A. , Rogers Donald W. , Matsunaga Nikita
Published: April 2011

The formally conjugated system of α-carbonyls in 2,3-butanedione does not impart thermodynamic stabilization, but significant destabilization of 5.9 kcal mol–1. The conjugated triple bonds of cyanogen cause a large thermodynamic destabilization of 11.4 kcal mol–1, which is the difference in the enthalpies of hydrogenation of the first and second triple bonds. Experimental thermochemical and structural measurements and theoretical ab initio (G3) calculations support the destabilizations being reported. This work focuses only on the observable thermodynamic effects (enthalpies of hydrogenation), which are not necessarily related to the ability of conjugated groups to transmit electronic effects.
A Profluorescent Azaphenalene Nitroxide for Nitroxide-Mediated Polymerization
Authors: Colwell John M. , Blinco James P. , Hulbert Courtney , Fairfull-Smith Kathryn E. , Bottle Steven E.
Published: April 2011

A novel nitroxide‐mediated polymerization (NMP) control agent; 1,1,3,3‐tetramethyl‐2,3‐dihydro‐2‐azaphenalen‐2‐yloxyl (TMAO), was used in the free‐radical polymerization of styrene. The conversion of styrene during NMP was studied using FT‐Raman spectroscopy and the effectiveness of TMAO as a NMP control agent was assessed by GPC analysis. Fidelity of the TMAO‐alkoxyamine end‐group on the synthesized polymers was confirmed by GPC, UV‐Vis and fluorescence spectroscopic analyses. Comparison to the well known NMP control agent, TEMPO was made. TMAO showed control of molecular weight approaching that of TEMPO. Attempts to improve the properties of TMAO as an NMP control agent by synthesizing an analogue with bulkier substituents around the nitroxide did not generate the target molecule but demonstrated some of the interesting chemistry of the azaphenalene ring system.
Phytochemical Study of Fagraea spp. Uncovers a New Terpene Alkaloid with Anti-Inflammatory Properties
Authors: Suciati  , Lambert Lynette K. , Ross Benjamin P. , Deseo Myrna A. , Garson Mary J.
Published: April 2011

Phytochemical investigation of the stem bark of F. racemosa JACK ex WALL (Loganiaceae) from East Java, Indonesia, has resulted in the isolation of a new alkaloid fagraeoside along with the iridoid glycoside secologanoside. Fagraeoside may be derived from the condensation of secologanin with L-asparagine, and represents a rare example of a terpene alkaloid in which the amino acid component is non-aromatic. Investigation of three additional species of Fagraea provided known lignans, iridoid or secoiridoid glycosides, and flavanol-6-C-glucosides, thus it is likely that iridoid and secoiridoid glucosides are chemotaxonomic markers for the Fagraea genus. Fagraeoside inhibited the production of prostaglandin E2 in 3T3 murine fibroblasts (IC50 ~5.1 µM), and was not cytotoxic to this cell line or to a P388 murine leukaemia cell line. Selected isolated compounds, including fagraeoside, showed low to moderate activity in anti-acetylcholinesterase screening.
Studies Directed Towards the Preparation of Probes for the Photoaffinity Labelling of Gibberellin Receptors
Authors: Crow James R. , Chandler Peter M. , Mander Lewis N.
Published: April 2011

Model studies for the preparation of photoaffinity probes designed to explore the nature of gibberellin receptor sites have provided a wide range of gibberellin derivatives that should afford useful scaffolds incorporating auxiliary groups attached to C-2 and C-12. Methodology features the stereocontrolled opening of 2β,3β-epoxy gibberellins by attack on the lower face at C-2, while functionalization of C-12 was effected by the rhodium acetate-catalyzed CH insertion reaction of a 17-diazo ketone. Compounds were screened for bioactivity in growth and barley endosperm-based bioassays.
Synthesis of 2,3-Dihydro-4(1H)-quinolones and the Corresponding 4(1H)-Quinolones via Low-Temperature Fries Rearrangement of N-Arylazetidin-2-ones
Authors: Lange Jens , Bissember Alex C. , Banwell Martin G. , Cade Ian A.
Published: April 2011

N-Arylazetidin-2-ones of the general form 1, which are readily prepared by Goldberg–Buchwald-type copper-catalyzed coupling of N-unsubstituted azetidin-2-ones with the relevant aryl halide or using Mitsunobu cyclization processes, undergo smooth Fries-rearrangement in triflic acid at 0–18°C to give the isomeric 2,3-dihydro-4(1H)-quinolones (2). Dehydrogenation of the latter compounds using 10% Pd on C in 1.0 M aqueous sodium hydroxide/propan-2-ol mixtures at ca. 82°C provides the corresponding 4(1H)-quinolones (3).
A Potential New RAFT - Click Reaction or a Cautionary Note on the Use of Diazomethane to Methylate RAFT-synthesized Polymers
Authors: Chen Ming , Moad Graeme , Rizzardo Ezio
Published: April 2011

It has been found that diazomethane undergoes a facile 1,3‐dipolar cycloaddition with both dithiobenzoate RAFT agents and the dithiobenzoate end‐groups of polymers formed by RAFT polymerization. Thus, 2‐cyanoprop‐2‐yl dithiobenzoate on treatment with diazomethane at room temperature provided a mixture of stereoisomeric 1,3‐dithiolanes in near quantitative (>95%) yield. A low‐molecular‐weight RAFT‐synthesized poly(methyl methacrylate) with dithiobenzoate end‐groups underwent similar reaction as indicated by immediate decolourization and a quantitative doubling of molecular weight. Higher‐molecular‐weight poly(methyl methacrylate)s were also rapidly decolourized by diazomethane and provided a product with a bimodal molecular weight distribution. Under similar conditions, the trithiocarbonate group does not react with diazomethane.
The Distal Effect of N-Electron-withdrawing Groups on the Stability of Peptide Carbon Radicals
Authors: Ho Junming , Coote Michelle L. , Easton Christopher J.
Published: April 2011

The effect of electron-withdrawing substituents, hydrogen bonding and protonation at amide nitrogen on the stability of radicals formed by loss of either a distal C–H adjacent to the amide carbonyl or one proximal to the amide nitrogen for a series of acetamides and diketopiperazines has been studied via high-level ab initio methods. These studies show that the effect is to destabilize the radicals formed by abstraction of the proximal hydrogens, typically by 10–20 kJ mol–1, and stabilize the distal radicals typically by 5–10 kJ mol–1, but only if the distal radicals are polarized by another dative substituent. The different radical stabilities are not directly mirrored in calculated activation energies or experimental rates of radical formation in bromination reactions, because there is significant charge development in these reaction transition states.
Effects of environmental variability on the spawning areas, catch, and recruitment of the Japanese common squid, Todarodes pacificus (Cephalopoda: Ommastrephidae), from the 1970s to the 2000s
Authors: Rosa A. L. , Yamamoto J. , Sakurai Y.
Published: April 2011

Rosa, A. L., Yamamoto, J., and Sakurai, Y. 2011. Effects of environmental variability on the spawning areas, catch, and recruitment of the Japanese common squid, Todarodes pacificus (Cephalopoda: Ommastrephidae), from the 1970s to the 2000s. – ICES Journal of Marine Science, 68: 1114–1121. The Japanese common squid, Todarodes pacificus, is one of the most commercially valuable squids in the world. It spawns almost throughout the year, with a seasonal peak in autumn and winter. Long-term changes in sea surface temperature (SST) and its effect on the spawning areas and catch of T. pacificus were analysed for 27 spawning seasons (September–April 1978–2006) in the Sea of Japan and East China Sea. The spawning area was inferred between the limits of 21–41°N and 121°–142°E, 100–500-m depth, the mean Kuroshio axis, and the 19.5–23°C SST range. The results revealed that the area surrounding Kyushu Island is gaining importance as a spawning area. In addition, the discontinuity of the spawning ground in the East China Sea (around 29°N 128°E) during the winter spawning period was demonstrated to be associated with a decrease in the catches by both the Japanese and the Korean fleets. This constriction of the spawning ground would act as an obstacle to either the adult squid, making it difficult for them to reach the most southern grounds, or the paralarvae and juveniles, which, because of adverse environmental conditions, might not be able to survive the early stages of the feeding migration.
The status of routine fishery data collection in Southeast Asia, central America, the South Pacific, and West Africa, with special reference to small-scale fisheries
Authors: de Graaf Gertjan J. , Grainger Richard J. R. , Westlund Lena , Willmann Rolf , Mills David , Kelleher Kieran , Koranteng Kwame
Published: April 2011

de Graaf, G. J., Grainger, R. J. R., Westlund, L., Willmann, R., Mills, D., Kelleher, K., and Koranteng, K. 2011. The status of routine fishery data collection in Southeast Asia, central America, the South Pacific, and West Africa, with special reference to small-scale fisheries. – ICES Journal of Marine Science, 68: 1743–1750. The Food and Agriculture Organization (FAO) strategy for improving information on the status and trends of capture fisheries (FAO Strategy STF) was endorsed by Member States and the UN General Assembly in 2003. Its overall objective is to provide a framework, strategy, and plan to improve knowledge and understanding of the status and trends of fisheries as a basis for policy-making and management, towards conservation and sustainable use of resources within ecosystems. The FAO supports the implementation of FAO Strategy STF in developing countries through a project known as FAO FishCode–STF, and an initiative funded by the World Bank entitled the “BigNumbers project”. The BigNumbers project underscored the importance of small-scale fisheries and revealed that catches by and employment in this sector tend to be underreported. An inventory of data collection systems made under the FAO FishCode–STF project showed that small-scale fisheries are not well covered. Their dispersed nature, the weak institutional capacity in many developing countries, and the traditional methods used make routine data collection cumbersome. Innovative sampling strategies are required. The main priority is a sample frame for small-scale fisheries. Sustainable strategies are most likely to be found outside the sector through population and agricultural household censuses and inside the sector through the direct involvement of fishers.
Evaluation of the Limping Child
Authors: Mordecai Simon , Avis Duncan
Published: April 2011

Hip pathology in children often manifests as a limp or abnormal gait, which is a common presentation in primary care. Although the majority of cases are self-limiting and can be managed without specialist referral, prompt identification of the more sinister causes is crucial to avoid permanent joint damage and long-term disability. This article outlines a systematic approach for dealing with a limping child in the community and highlights the key points to gain from the history and examination to enable easy identification of the cases that need to be referred.
Demonstrating superposition of waves and Fourier analysis with tuning forks and MacScope II
Authors: LoPresto Michael C.
Published: April 2011

In this paper we describe a simple demonstration that shows how the Fourier spectrum of sound waves affect sound quality. It requires only a set of tuning forks, mounted on resonance boxes, and computer data collection hardware and software capable of capturing sound waves and displaying their waveforms and Fourier spectra.