bluuebunny/crossref_metadata_2025 huggingface dataset:
Low‐temperature electrospun silk scaffold forin vitromucosal modeling
Authors: Bulysheva Anna A. , Bowlin Gary L. , Klingelhutz Aloysius J. , Yeudall W. Andrew
Published: January 2012

Electrospinning is often used to create scaffolding as a biomimetic of the extracellular matrix of tissues. A frequent limitation of this technique for three‐dimensional tissue modeling is poor cell infiltration throughout the void volume of scaffolds. Here, we generated low‐temperature electrospun silk scaffolds and compared these with conventional electrospun silk scaffolds in terms of mechanical properties, void volume, cell infiltration, cell viability, and potential to support mucosal models under three‐dimensional culture conditions. Low‐temperature electrospun silk scaffolds supported fibroblast attachment and infiltration throughout the volume of the scaffolds, while conventional electrospun scaffolds exhibited limited cell infiltration with fibroblasts attaching exclusively to the seeding surface of the scaffolds. The porosity of low‐temperature electrospun scaffolds was 93% compared with 88% of conventional electrospun silk scaffolds. Uniaxial tensile testing showed a 3.5‐fold reduction in strength of low‐temperature electrospun silk compared with the conventional in terms of peak stress and modulus but no significant change in strain at break. Mucosal modeling with fibroblast‐keratinocyte or fibroblast‐carcinoma cocultures showed similar results, with cell infiltration occurring only in low‐temperature electrospun scaffolds. Cell viability was confirmed using live/dead staining after 21 days in culture. Furthermore, low‐temperature electrospun silk scaffolds were able to support keratinocyte differentiation, as judged by involucrin immunoreactivity. The low‐temperature electrospun silk scaffold that we have developed eliminates the limitation of electrospun silk scaffolds in terms of cell infiltration and, therefore, can potentially be used for a wide range of tissue engineering purposes ranging fromin vitrotissue modeling toin vivotissue regeneration purposes. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Adhesion, activation, and aggregation of blood platelets and biofilm formation on the surfaces of titanium alloys Ti6Al4V and Ti6Al7Nb
Authors: Walkowiak‐Przybyło M. , Klimek L. , Okrój W. , Jakubowski W. , Chwiłka M. , Czajka A. , Walkowiak B.
Published: January 2012

Titanium alloys are still on the top list of fundamental materials intended for dental, orthopedics, neurological, and cardiovascular implantations. Recently, a special attention has been paid to vanadium‐free titanium alloy, Ti6Al7Nb, that seems to represent higher biocompatibility than traditional Ti6Al4V alloy. Surprisingly, these data are not thoroughly elaborated in the literature; particularly there is a lack of comparative experiments conducted simultaneously and at the same conditions. Our study fills these shortcomings in the field of blood contact and microbiological colonization. To observe platelets adhesion and biofilm formation on the surfaces of compared titanium alloys, fluorescence microscope Olympus GX71 and scanning electron microscope HITACHI S‐3000N were used. Additionally, flow cytometry analysis of platelets aggregation and activation in the whole blood after contact with sample surface, as an essential tool for biomaterial thrombocompatibility assessment, was proposed. As a result of our study it was demonstrated that polished surfaces of Ti6Al7Nb and Ti6Al4V alloys after contact with whole citrated blood and E. coli bacterial cells exhibit a considerable difference. Overall, it was established that Ti6Al4V has distinct tendency to higher thrombogenicity, more excessive bacterial biofilm formation and notable cytotoxic properties in comparison to Ti6Al7Nb. However, we suggest these studies should be extended for other types of cells and biological objects. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Extended and sequential delivery of protein from injectable thermoresponsive hydrogels
Authors: Nelson Devin M. , Ma Zuwei , Leeson Cory E. , Wagner William R.
Published: January 2012

Thermoresponsive hydrogels are attractive for their injectability and retention in tissue sites where they may serve as a mechanical support and as a scaffold to guide tissue remodeling. Our objective in this report was to develop a thermoresponsive, biodegradable hydrogel system that would be capable of protein release from two distinct reservoirs—one where protein was attached to the hydrogel backbone, and one where protein was loaded into biodegradable microparticles mixed into the network. Thermoresponsive hydrogels consisting of N‐isopropylacrylamide (NIPAAm), 2‐hydroxyethyl methacrylate (HEMA), and biodegradable methacrylate polylactide were synthesized along with modified copolymers incorporating 1 mol % protein‐reactive methacryloxy N‐hydroxysuccinimide (MANHS), hydrophilic acrylic acid (AAc), or both. In vitro bovine serum albumin (BSA) release was studied from hydrogels, poly(lactide‐co‐glycolide) microparticles, or microparticles mixed into the hydrogels. The synthesized copolymers were able to gel below 37°C and release protein in excess of 3 months. The presence of MANHS and AAc in the copolymers was associated with higher loaded protein retention during thermal transition (45% vs. 22%) and faster release (2 months), respectively. Microspheres entrapped in the hydrogel released protein in a delayed fashion relative to microspheres in saline. The combination of a protein‐reactive hydrogel mixed with protein‐loaded microspheres demonstrated a sequential release of specific BSA populations. Overall the described drug delivery system combines the advantages of injectability, degradability, extended release, and sequential release, which may be useful in tissue engineering applications. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Comparison of the oropharyngeal cavity in the Starksiini (Teleostei: Blenniiformes: Labrisomidae): Taste buds and teeth, including a comparison with closely‐related genera
Authors: Fishelson Lev , Baldwin Carole C. , Hastings Philip A.
Published: January 2012

The present study describes the distribution of taste buds and teeth in the oropharyngeal cavity of 13 species of adult (18–60 mm SL) Starksiini fishes inhabiting subtidal waters of the Neotropical region. Four types of taste buds described previously in other fish groups were observed within the oropharyngeal cavity, of which type I, situated on prominent protruding papillae, is the most common. The number of taste buds in this cavity varies considerably, ranging from ca. 202 in Starksia lepicoelia to ca. 770 in S. sluiteri. In all the studied species, taste buds are more numerous on the posterior (160–396) than on the anterior (42–294) part of the oropharyngeal cavity. The presence of different numbers of taste buds in different Starksiini species of the same standard length suggests that numbers of taste buds are not directly correlated with size and may be species‐specific. Teeth are found on the premaxilla, dentary, vomer, palatine (in some species) and the upper and lower pharyngeal jaws (third pharyngobranchials and fifth ceratobranchials, respectively); the form and number of teeth and taste buds on each of these sites differs among the various species of Starksiini and between them and closely related species of the labrisomid tribes Labrisomini, Mnierpini, and Paraclinini. The results thus suggest potential systematic value in certain features of the oropharyngeal cavity for blenniiform fishes. It is also shown that benthic‐feeding omnivorous fishes have higher densities of taste buds than piscivorous fishes. A possible correlation among numbers of taste buds, their positions in the oropharyngeal cavity, and other parameters is discussed. J. Morphol., 2012. © 2012 Wiley Periodicals, Inc.
From the Schnauzenorgan to the back: Morphological comparison of mormyromast electroreceptor organs at different skin regions of Gnathonemus petersii
Authors: Amey‐Özel Monique , Hollmann Michael , von der Emde Gerhard
Published: January 2012

The nocturnally active weakly electric fish Gnathonemus petersii is known to employ active electrolocation for the detection of objects and for orientation in its environment. The fish emits pulse‐type electric signals with an electric organ and perceives these signals with more than 3,000 epidermal electroreceptor organs, the mormyromasts, which are distributed over the animal's skin surface. In this study, we measured the metric dimensions of the mormyromasts from different body regions to find structural and functional specialization of the various body parts. We focused on the two foveal regions of G. petersii, which are located at the elongated and movable chin (the Schnauzenorgan; SO) and at the nasal region (NR), the skin region between the mouth and the nares. These two foveal regions were compared to the dorsal part (back) of the fish, which contains typical nonfoveal mormyromasts. While the gross anatomy of the mormyromasts from all skin regions is similar, the metric dimensions of the main substructures differed. The mormyromasts at the SO are the smallest and contain the smallest receptor cells. In addition, the number of receptor cells per organ is lowest at the SO. In contrast, at the back the biggest receptor organs with the highest amount of receptor cells per organ occur. The mormyromasts at the NR are in several respects intermediate between those from the back and the SO. However, mormyromasts at the NR are longer than those at all other skin regions, the canal leading from the receptor pore to the inner chambers were the longest and the overlaying epidermal layers are the thickest. These results show that mormyromasts and the epidermis they are embedded in at both foveal regions differ specifically from those found on the rest of the body. The morphological specializations lead to functional specialization of the two foveae. J. Morphol., 2012. © 2012 Wiley Periodicals, Inc.
Corrosion of steel by carbonate‐bicarbonate solution for CO2 capture
Authors: Zhang J. , Martin F. J.
Published: January 2012

Hot alkaline solutions, such as potassium/sodium carbonate solutions, have been used for carbon dioxide removal and capture processes. This survey summarizes the available corrosion data of steels in the solution with carbon dioxide dissolved. Plant operating experiences and laboratory testing results are considered. The corrosion mechanisms, important factors, inhibitor effects, and corrosion cracking are analyzed.
Copper corrosion inhibition by polyaspartic acid and imidazole
Authors: Wang H. P. , Wu Q. , Li C. M. , Gu N.
Published: January 2012

This work reveals the corrosion inhibition effect of polyaspartic acid (PASP) and imidazole (IM) on copper in 3 wt% aminosulfonic acid acting as mixed‐type inhibitor of predominant cathodic effect. Potentiodynamic polarization and electrochemical impedance spectroscopy work prove that at 30 °C, 1.0 g/L PASP alone gave the best inhibitory effect of 89.8%; the inhibition efficiency could reach up to 95.4% when combining PASP and IM at the same ratio in total of 1.0 g/L. The anti‐corrosion mechanism of PASP and IM on copper is proposed from the characteristic molecular structures of these two chemicals.
Corrosion of stainless steel grades in molten NaOH/KOH eutectic at 250 °C: AISI304 austenitic and 2205 duplex
Authors: Bozzini B. , Barella S. , Bogani F. , Giovannelli G. , Natali S. , Scarselli G. , Boniardi M.
Published: January 2012

The present paper focuses on the corrosion of an austenitic (AISI304) and a duplex (2205) stainless steel grade in molten KOH/NaOH 50 w/o eutectic at 250 °C. Experimental activities have been performed consisting in electrochemical measurements (linear sweep voltammetry and electrochemical impedance spectrometry) complemented by metallographic (in‐plane and cross‐sectional SEM micrography), structural (X‐ray diffractometry) and compositional (EDX line‐profiles) characterisation of the materials attacked under electrochemically controlled conditions. Electrochemical measurements have shown that AISI304 exhibits a passivating behaviour, characterised by two passivation peaks and a transpassive threshold, while duplex, does not yield a clear indication of passivation. AISI304 was found to fail by intergranular corrosion and to be covered in both passive and transpassive conditions, by an incoherent scale, containing electrolyte species. Duplex samples, instead tends to fail by homogeneous attack and exhibit a range of scale structures, depending on the applied potential.
The failure of GCH at a degree of supercompactness
Authors: Cody Brent
Published: January 2012

We determine the large cardinal consistency strength of the existence of a λ‐supercompact cardinal κ such that \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\mathsf {GCH}$\end{document} fails at λ. Indeed, we show that the existence of a λ‐supercompact cardinal κ such that 2λ ≥ θ is equiconsistent with the existence of a λ‐supercompact cardinal that is also θ‐tall. We also prove some basic facts about the large cardinal notion of tallness with closure.
Impaired olfaction and other prodromal features in the Parkinson At‐Risk Syndrome study
Authors: Siderowf Andrew , Jennings Danna , Eberly Shirley , Oakes David , Hawkins Keith A. , Ascherio Albert , Stern Matthew B. , Marek Kenneth ,   the PARS Investigators
Published: January 2012

To test the association between impaired olfaction and other prodromal features of PD in the Parkinson At‐Risk Syndrome Study. The onset of olfactory dysfunction in PD typically precedes motor features, suggesting that olfactory testing could be used as a screening test. A combined strategy that uses other prodromal nonmotor features, along with olfactory testing, may be more efficient than hyposmia alone for detecting the risk of PD. Individuals with no neurological diagnosis completed a mail survey, including the 40‐item University of Pennsylvania Smell Identification Test, and questions on prodromal features of PD. The frequency of reported nonmotor features was compared across individuals with and without hyposmia. A total of 4,999 subjects completed and returned the survey and smell test. Of these, 669 were at or below the 15th percentile based on age and gender, indicating hyposmia. Hyposmics were significantly more likely to endorse nonmotor features, including anxiety and depression, constipation, and rapid eye movement sleep behavior disorder symptoms, and to report changes in motor function. Twenty‐six percent of subjects with combinations of four or more nonmotor features were hyposmic, compared to 12% for those reporting three or fewer nonmotor features (P < 0.0001). Hyposmia is associated with other nonmotor features of PD in undiagnosed individuals. Further assessment of hyposmic subjects using more specific markers for degeneration, such as dopamine transporter imaging, will evaluate whether combining hyposmia and other nonmotor features is useful in assessing the risk of future neurodegeneration. © 2012 Movement Disorder Society © 2012 Movement Disorder Society
Digital Filters for Molecular Interaction Field Descriptors
Authors: Barbosa Euzébio Guimarães , Ferreira Márcia Miguel Castro
Published: January 2012

Descriptor properties are often neglected when building 3D‐QSAR models. The relevance of correlation and distribution profiles is tested in terms of the models’ prediction power. A different approach to filter descriptors prior to variable selection is proposed. Additionally, a protocol for molecular interaction field descriptors selection and model validation is presented. The algorithms and protocols presented are quite simple and enable a different and powerful way to create parsimonious interaction field‐based models.
Types of Office‐Based Anesthetics
Authors: Hausman Laurence M. , Dickstein Elisha J. , Rosenblatt Meg A.
Published: January 2012

Over the past several decades, there have been evolutionary changes in both surgery and anesthesia. Newer anesthetics have excellent safety profiles and are associated with fewer hemodynamic side effects and rapid elimination from the body. Innovative surgical techniques are less invasive and cause less perioperative patient pain. These developments have fueled the growth of office‐based surgery and anesthesia. All types of anesthesia, including local, monitored anesthesia care, general, and regional anesthesia, have been used safely within the private practitioner's office. Because of the remote nature of the private surgeon's office, the proper selection of both patient and procedure to be performed is of utmost importance. It is likewise imperative that the practitioner assures that the patient does not experience excessive postoperative pain and/or nausea and vomiting. It is of the utmost importance that the practicing anesthesiologist assure that every location in which procedures and surgeries are performed is a safe anesthetizing location. Mt Sinai J Med 79:107–115, 2012. © 2012 Mount Sinai School of Medicine
Managing Chronic Pain With Spinal Cord Stimulation
Authors: Epstein Lawrence J. , Palmieri Marco
Published: January 2012

Since its introduction as a procedure of last resort in a terminally ill patient with intractable cancer‐related pain, spinal cord stimulation has been used to effectively treat chronic pain of varied origins. Spinal cord stimulation is commonly used for control of pain secondary to failed back surgery syndrome and complex regional pain syndrome, as well as pain from angina pectoris, peripheral vascular disease, and other causes. By stimulating one or more electrodes implanted in the posterior epidural space, the patient feels paresthesias in their areas of pain, which reduces the level of pain. Pain is reduced without the side effects associated with analgesic medications. Patients have improved quality of life and improved function, with many returning to work. Spinal cord stimulation has been shown to be cost effective as compared with conservative management alone. There is strong evidence for efficacy and cost effectiveness of spinal cord stimulation in the treatment of pain associated with intractable angina, failed back surgery syndrome, and complex regional pain syndrome. In this article, we review the history and pathophysiology of spinal cord stimulation, and the evidence (or lack thereof) for efficacy in common clinical practice. Mt Sinai J Med 79:123–132, 2012. © 2012 Mount Sinai School of Medicine
Lungs in Critical Care: New Look at Old Practices
Authors: Papadakos Peter J. , Karcz Marcin , Schwaiberger David , Lachmann Burkhard
Published: January 2012

There has been a marked increase in the volume of critical care services throughout the world in the last few years with the wide addition of intensive care units in developing nations. Despite extensive efforts in research and some progress in treatment, mortality and morbidity have not significantly decreased. Recent research has demonstrated that modifying standard practices of mechanical ventilation and sedation may contribute to improved patient outcomes. This article discusses how new aspects of physiologically based mechanical ventilation with minimal intravenous sedation may help decrease the incidence of nosocomial pneumonia, modulate systemic inflammatory response, and reduce the incidence of delirium. These interlinked modalities may someday contribute to decreased length of stay and a reduction in treatment‐related complications. These concepts may also open new avenues to improve patient care and stimulate ongoing investigation in other areas related to physiologically based critical care practices. Mt Sinai J Med 79:116–122, 2012. © 2012 Mount Sinai School of Medicine
Evaluation of partial and total splenectomy in children with sickle cell disease using an internet‐based registry
Authors: Mouttalib Sofia , Rice Henry E. , Snyder Denise , Levens Justin S. , Reiter Audra , Soler Pauline , Rothman Jennifer A. , Thornburg Courtney D.
Published: January 2012

Background

Clinical outcomes of children with sickle cell disease (SCD) who undergo total or partial splenectomy (PS) are poorly defined. The purpose of this retrospective study was to initiate an Internet‐based registry to facilitate analysis of clinical outcomes for these children. We hypothesized that both surgical procedures would be well tolerated and would eliminate risk of splenic sequestration.

Methods

We developed a web‐based registry using the Research Electronic Data Capture (REDCap) platform. Children were included if they had SCD and underwent total splenectomy (TS) or PS between 2003 and 2010. Clinical outcomes were compared between cohorts, with follow‐up to 1 year.

Results

Twenty‐four children were included, TS (n = 15) and PS (n = 9). There were no differences in surgical time or intraoperative blood loss. The length of stay was longer after PS (4.1 ± 1.7 days) compared to TS, (2.4 ± 1.2 days, P = 0.02). Within 30 days of surgery, 2 (20%) patients had acute chest syndrome (ACS) following TS and 2 (15%) patients had ACS after PS. During 1‐year follow‐up, no patient in either cohort had recurrent splenic sequestration, venous thrombosis or overwhelming postsplenectomy sepsis. All children who were transfused preoperatively to prevent recurrent splenic sequestration successfully discontinued transfusions.

Conclusions

Both TS and PS result in favorable hematologic outcomes and low risk of adverse events for children with SCD. A REDCap‐based registry may facilitate data entry and analysis of clinical outcomes to allow for comparison between different types of splenectomy. Pediatr Blood Cancer 2012; 59: 100–104. © 2012 Wiley Periodicals, Inc.
Toxicity and efficacy of the acetylcholinesterase (AChe) inhibitor donepezil in childhood brain tumor survivors: A pilot study
Authors: Castellino Sharon M. , Tooze Janet A. , Flowers Lynn , Hill Debbie F. , McMullen Kevin P. , Shaw Edward G. , Parsons Susan K.
Published: January 2012

Background

Neurocognitive deficits are a recognized late effect of curative brain tumor therapy. We evaluated the feasibility, tolerance, and impact of a pilot pharmacologic intervention with the acetylcholinesterase (AChe) inhibitor, donepezil, in pediatric brain tumor (BT) survivors at risk for neurocognitive dysfunction.

Procedure

A single institution open‐label pilot study was conducted in childhood BT survivors: ≥1 year from cancer treatment; and who received >23.5 Gy cranial radiation therapy (RT). Toxicity, adherence and neurocognitive outcomes were evaluated at baseline and serially during 24 weeks of donepezil, and following a 12‐week washout period off drug.

Results

From a pool of subjects, 13 were successfully contacted and screened, and 11 met all eligibility criteria to initiate donepezil at a median of 4.7 (1.9–11.9) years from RT. Seventy‐two percent of patients completed the 24‐week drug study visit. Despite transient gastrointestinal toxicity (vomiting and diarrhea) in 30% of patients there was no weight loss on donepezil. Significant improvement in performance was noted at 24 weeks on the Dellis–Kaplan Executive Function (D‐KEF) Tower test (P < 0.001), the Wide Range Assessment of Memory and Learning, 2nd Edition (WRAML‐2) Visual memory (P = 0.007), and the Number/Letter task (P = 0.018).

Conclusions

Donepezil was well tolerated among childhood BT survivors who had received substantial prior therapy. Based on improved executive function and memory performance in this pilot trial, a randomized placebo controlled trial of this pharmacologic agent is warranted to fully evaluate its efficacy in remediating neurocognitive dysfunction. Pediatr Blood Cancer 2012;59:540–547. © 2012 Wiley Periodicals, Inc.
The role of the oligosaccharide binding cleft of rice BGlu1 in hydrolysis of cellooligosaccharides and in their synthesis by rice BGlu1 glycosynthase
Authors: Pengthaisong Salila , Withers Stephen G. , Kuaprasert Buabarn , Svasti Jisnuson , Ketudat Cairns James R.
Published: January 2012

Rice BGlu1 β‐glucosidase nucleophile mutant E386G is a glycosynthase that can synthesize p‐nitrophenyl (pNP)‐cellooligosaccharides of up to 11 residues. The X‐ray crystal structures of the E386G glycosynthase with and without α‐glucosyl fluoride were solved and the α‐glucosyl fluoride complex was found to contain an ordered water molecule near the position of the nucleophile of the BGlu1 native structure, which is likely to stabilize the departing fluoride. The structures of E386G glycosynthase in complexes with cellotetraose and cellopentaose confirmed that the side chains of N245, S334, and Y341 interact with glucosyl residues in cellooligosaccharide binding subsites +2, +3, and +4. Mutants in which these residues were replaced in BGlu1 β‐glucosidase hydrolyzed cellotetraose and cellopentaose with kcat/Km values similar to those of the wild type enzyme. However, the Y341A, Y341L, and N245V mutants of the E386G glycosynthase synthesize shorter pNP‐cellooligosaccharides than do the E386G glycosynthase and its S334A mutant, suggesting that Y341 and N245 play important roles in the synthesis of long oligosaccharides. X‐ray structural studies revealed that cellotetraose binds to the Y341A mutant of the glycosynthase in a very different, alternative mode not seen in complexes with the E386G glycosynthase, possibly explaining the similar hydrolysis, but poorer synthesis of longer oligosaccharides by Y341 mutants.
Morin hydrate inhibits amyloid formation by islet amyloid polypeptide and disaggregates amyloid fibers
Authors: Noor Harris , Cao Ping , Raleigh Daniel P.
Published: January 2012

The polypeptide hormone Islet Amyloid Polypeptide (IAPP, amylin) is responsible for islet amyloid formation in type‐2 diabetes and in islet cell transplants, where it may contribute to graft failure. Human IAPP is extremely amyloidogenic and fewer inhibitors of IAPP amyloid formation have been reported than for the Alzheimer's Aβ peptide or for α‐synuclein. The ability of a set of hydroxyflavones to inhibit IAPP amyloid formation was tested. Fluorescence detected thioflavin‐T‐binding assays are the most popular methods for measuring the kinetics of amyloid formation and for screening potential inhibitors; however, we show that they can lead to false positives with hydroxyflavones. Several of the compounds inhibit thioflavin‐T fluorescence, but not amyloid formation; a result which highlights the hazards of relying solely on thioflavin‐T assays to screen potential inhibitors. Transmission electron microscopy (TEM) and right‐angle light scattering show that Morin hydrate (2′,3,4′,5,7‐Pentahydroxyflavone) inhibits amyloid formation by human IAPP and disaggregates preformed IAPP amyloid fibers. In contrast, Myricetin, Kaempferol, and Quercetin, which differ only in hydroxyl groups on the B‐ring, are not effective inhibitors. Morin hydrate represents a new type of IAPP amyloid inhibitor and the results with the other compounds highlight the importance of the substitution pattern on the B‐ring.
Structure–function relationship of assimilatory nitrite reductases from the leaf and root of tobacco based on high‐resolution structures
Authors: Nakano Shogo , Takahashi Misa , Sakamoto Atsushi , Morikawa Hiromichi , Katayanagi Katsuo
Published: January 2012

Tobacco expresses four isomers of assimilatory nitrite reductase (aNiR), leaf‐type (Nii1 and Nii3), and root‐type (Nii2 and Nii4). The high‐resolution crystal structures of Nii3 and Nii4, determined at 1.25 and 2.3 Å resolutions, respectively, revealed that both proteins had very similar structures. The Nii3 structure provided detailed geometries for the [4Fe–4S] cluster and the siroheme prosthetic groups. We have generated two types of Nii3 variants: one set focuses on residue Met175 (Nii3‐M175G, Nii3‐M175E, and Nii3‐M175K), a residue that is located on the substrate entrance pathway; the second set targets residue Gln448 (Nii3‐Q448K), a residue near the prosthetic groups. Comparison of the structures and kinetics of the Nii3 wild‐type (Nii3‐WT) and the Met175 variants showed that the hydrophobic side‐chain of Met175 facilitated enzyme efficiency (kcat/Km). The Nii4‐WT has Lys449 at the equivalent position of Gln448 in Nii3‐WT. The enzyme activity assay revealed that the turnover number (kcat) and Michaelis constant (Km) of Nii4‐WT were lower than those of Nii3‐WT. However, the kcat/Km of Nii4‐WT was about 1.4 times higher than that of Nii3‐WT. A comparison of the kinetics of the Nii3‐Q448K and Nii4‐K449Q variants revealed that the change in kcat/Km was brought about by the difference in Residue 448 (defined as Gln448 in Nii3 and Lys449 in Nii4). By combining detailed crystal structures with enzyme kinetics, we have proposed that Nii3 is the low‐affinity and Nii4 is the high‐affinity aNiR.
Life history parameters and scale‐cover surface area of Aonidiella aurantii are altered in a mating disruption environment: implications for biological control
Authors: Vanaclocha Pilar , Vacas Sandra , Alfaro Cristina , Primo Jaime , Verdú María J , Navarro‐Llopis Vicente , Urbaneja Alberto
Published: January 2012

BACKGROUND: In recent years, environmentally safe measures to control the California red scale (CRS), Aonidiella aurantii (Maskell), have been successfully implemented. These measures include mating disruption (MD) and biological control. The goal of this study was to examine the effect of high concentrations of the CRS sex pheromone on its life history parameters and scale‐cover surface area under controlled laboratory conditions.

RESULTS: The developmental time of both males and females of CRS increased with exposure to airborne pheromone. MD had an effect on both the total number of progeny and on the crawler production period for females. Accordingly, demographic parameters such as net fecundity (R0) and intrinsic rate of increase (rm) were significantly lower in the pheromone‐treated populations. The largest scale‐cover surface areas were observed in the CRS reared in the pheromone environment.

CONCLUSION: A clear influence of airborne pheromone on the biology of CRS has been demonstrated. In addition to the classical mating disruption benefits of this technique, additional benefits, such as increase in the duration of exposure to natural enemies and increase in size, which benefits some species of parasitoids, have been confirmed. Copyright © 2012 Society of Chemical Industry
ON THE IMPORTANCE OF CONSIDERING CHANNEL MICROFORMS IN GROUNDWATER MODELS OF HYPORHEIC EXCHANGE
Authors: Käser D. H. , Binley A. , Heathwaite A. L.
Published: January 2012

The infiltration of stream water in the sediment and its return to the stream—a process known here as hyporheic exchange flows (HEF)—is a critical control of the structure and functions of the stream ecosystem. River restoration programmes will increasingly require quantitative methods for evaluating this influence. Previous studies have already shown the potential of numerical groundwater models to characterize HEF and compare restoration scenarios. Although various sources of uncertainty are acknowledged, the potential effect of small streambed structures (or microforms), such as grains or ripples, embedded in channel‐unit scale structures (or macroforms), such as riffle‐pool sequences, is commonly ignored. Here, a simple conceptualization through a 2‐D vertical model is used to test whether (i) ignoring microforms in groundwater models at the macroform scale can impact estimations of residence times; (ii) microforms can influence HEF patterns driven by macroforms; and conversely (iii) the uncertainty of head measurements in stream piezometers can affect our understanding of HEF patterns. Results show that (i) residence times and flux estimations can be strongly affected by the modeller's choice to represent microform‐induced HEF or not; (ii) the interaction of the microform and macroform scales can induce various subsurface flow patterns; and (iii) the perceived significance of microform‐induced HEF is highly sensitive to the uncertainty of in‐stream measurements of subsurface heads. Little is known about the relative efficiency of these microform and macroform scales, which are effectively influencing exchange at different depths and interacting with each other. Future studies that consider biogeochemical cycling or streambed ecology should be placed in this context. It is also necessary to find ways of including this source of uncertainty in groundwater models of HEF. Copyright © 2012 John Wiley & Sons, Ltd.
USING LOW‐COST SIDE‐SCAN SONAR FOR BENTHIC MAPPING THROUGHOUT THE LOWER FLINT RIVER, GEORGIA, USA
Authors: Kaeser Adam J. , Litts Thomas L. , Tracy T. Wesley
Published: January 2012

An efficient, low‐cost approach for mapping habitat features in navigable streams is needed to support the research and management of aquatic ecosystems at the landscape level. We developed a method that uses high‐resolution (455 kHz) side‐scan sonar imagery obtained with the inexpensive (~$2000) Humminbird® Side Imaging system and ArcGIS to produce sonar image maps (SIMs) used to interpret and map habitat features such as substrates and large woody debris, in addition to continuously recording depth along the survey route. This method was recently demonstrated and evaluated in several small streams in southwestern Georgia (30–50 m width, 40 km mapped). To evaluate the feasibility of this method for mapping substrate and depth in larger rivers and over greater spatial extents, we conducted a sonar survey and generated SIMs for 124 km of the lower Flint River (85–140 m width). We interpreted the SIMs to digitize and classify substrate and bank boundaries. To assess classification accuracy, we visually inspected substrate at randomly assigned reference locations. A comparison of reference and map data revealed an overall classification accuracy of 84%. These results were consistent with previous findings and indicate that low‐cost side‐scan sonar is also an effective mapping tool for larger rivers. The sonar survey did, however, result in more missing and unsure substrate data and a lower map accuracy for fine‐textured substrates than previously achieved when mapping smaller streams. We found a strong, positive relationship (r2 = 0.89) between the sonar range and the proportion of unsure substrate in the map, suggesting that a multi‐pass, parallel‐transect sonar survey could be used to maintain high‐image resolution when stream widths exceed 100 m and/or obstructions, such as islands, are encountered. Applications for sonar‐based habitat maps are widespread and numerous. The ability to produce these maps efficiently at low‐cost is within the grasp of researchers and managers alike. Copyright © 2012 John Wiley & Sons, Ltd.
RESERVOIR COMPENSATION RELEASES: IMPACT ON THE MACROINVERTEBRATE COMMUNITY OF THE DERWENT RIVER, NORTHUMBERLAND, UK—A LONGITUDINAL STUDY
Authors: Maynard Carly M. , Lane Stuart N.
Published: January 2012

River regulation for the purposes of public water supply causes the flow regime downstream of a dam to change. Traditionally, in the UK, such regulation was accompanied by requirements for reservoir releases to compensate downstream water users (e.g. industry) for the loss of natural flow (compensation flows). In this article, we compare a unique pre‐impoundment macroinvertebrate data set for a regulated upland river with survey data post‐impoundment. This allows a longitudinal assessment of the response of the system to regulation. The Derwent River, Northumberland, was impounded in 1966. Impacts on the hydrological regime were quantified by comparing long‐term hydrographs, flow duration curves, flow ranges and flashiness indices for the pre‐impoundment and post‐impoundment periods. The comparison of changes in macroinvertebrate richness and diversity post‐impoundment showed that the change in flow regime has had limited effect on the ecological community structure. The flow regime of the Derwent River has become less flashy with fewer extreme events, and the richness and the diversity of macroinvertebrates have, in some cases, increased and at worst have not deteriorated. We suggest that this reflects the strict compensation regime, which has guaranteed minimum flows at all times. Copyright © 2012 John Wiley & Sons, Ltd.
Foreign IPO capital market choice: Understanding the institutional fit of corporate governance
Authors: Moore Curt B. , Bell R. Greg , Filatotchev Igor , Rasheed Abdul A.
Published: January 2012

While product market choices have been central to strategy formulation for firms in the past, the integration of financial markets makes the choice of capital markets an equally important strategic decision. We advance a comparative institutional perspective to explain capital market choice by firms making an IPO in a foreign market. We find that internal governance characteristics (founder‐CEO, executive incentives, and board independence) and external network characteristics (prestigious underwriters, degree of venture capitalist syndication, and board interlocks) are significant predictors of foreign capital market choice by foreign IPO firms. Our results suggest foreign IPO firms select a host market where the firms' governance characteristics and third party affiliations fit the host market's institutional environment. Copyright © 2012 John Wiley & Sons, Ltd.
Data‐Driven Pareto Optimization for Microalloyed Steels Using Genetic Algorithms
Authors: Kumar Aman , Chakrabarti Debalay , Chakraborti Nirupam
Published: January 2012

A data base was put together for the mechanical properties of microalloyed steels, which contained about 800 entries for ultimate tensile strength (UTS), yield strength (YS), and elongation. Using an evolutionary neural network, based upon a predator–prey genetic algorithms of bi‐objective type, this information was used to construct data‐driven models for UTS, YS, and elongation. The optimum Pareto tradeoffs between these properties were obtained using a multi‐objective genetic algorithm. The results led to some hitherto unexplored steel compositions with optimum properties. Some such steels were actually cast and the experimentally observed property values were found to be well in accord with the predicted results.
P2X receptors in bone
Authors: Gartland Alison
Published: January 2012

Bone is a dynamic organ that from the early stages of development defines an organism's form and function and responds to the external environment, a process that continues as the organism grows and persists even once maturity is reached. The formation, growth, and integrity of bone are co‐ordinated and maintained throughout life via the finely tuned actions of osteoblasts and osteoclasts, with disruption in this balance leading to skeletal abnormalities and bone disease. The precise complement of mechanisms balancing these actions is not fully known, although several regulatory systems are known to be involved and current treatments for bone disease target these systems. The actions of purinergic signaling in bone have come to light over the past 20 years or so, but previously the emphasis was largely placed upon G‐protein coupled P2Y receptors. This article details the current status of P2X receptors in bone, mainly focussing on the P2X7 receptor for which the most compelling evidence exists for its regulatory role in bone. The contribution of other P2X receptors to bone biology and future directions are also discussed. WIREs Membr Transp Signal 2012, 1:221–227. doi: 10.1002/wmts.26

For further resources related to this article, please visit the WIREs website.
Metabotropic glutamate receptor‐mediated signaling in neuroglia
Authors: Loane David J. , Stoica Bogdan A. , Faden Alan I.
Published: January 2012

Metabotropic glutamate (mGlu) receptors are G‐protein‐coupled receptors, including eight subtypes classified into three groups (I–III) based upon sequence homology, signal transduction mechanism and pharmacological profile. Although most studied with regard to neuronal function and modulation, mGlu receptors are also expressed by neuroglia—including astrocytes, microglia, and oligodendrocytes. Activation of mGlu receptors on neuroglia under both physiologic and pathophysiologic conditions mediates numerous actions that are essential for intrinsic glial cell function, as well as for glial–neuronal interactions. Astrocyte mGlu receptors play important physiological roles in regulating neurotransmission and maintaining neuronal homeostasis. However, mGlu receptors on astrocytes and microglia also serve to modulate cell death and neurological function in a variety of pathophysiological conditions such as acute and chronic neurodegenerative disorders. The latter effects are complex and bidirectional, depending on which mGlu receptor subtypes are activated. WIREs Membr Transp Signal 2012, 1:136–150. doi: 10.1002/wmts.30

For further resources related to this article, please visit the WIREs website.
Inositol 1,4,5‐trisphosphate receptor degradation pathways
Authors: Wojcikiewicz Richard J. H.
Published: January 2012

We know where cellular proteins come from, but know very little about where they go. This is a fairly accurate generalization, since a great deal of emphasis has been placed on understanding the synthesis of proteins, the regulation of their synthesis, and if appropriate, their posttranslational modification, assembly into complexes, and insertion into membranes. In contrast, very little attention has been paid to the details of protein turnover—cellular proteins only have a limited lifetime and are somehow degraded to be replaced by new copies, but how? This generalization is certainly applicable to inositol 1,4,5‐trisphosphate (IP3) receptors. In summary, it seems that under resting conditions, IP3 receptors are slowly disposed of in a nonspecific manner that may involve trafficking to lysosomes, whereas activated IP3 receptors are rapidly and selectively degraded by the ubiquitin‐proteasome pathway. WIREs Membr Transp Signal 2012, 1:126–135. doi: 10.1002/wmts.4

For further resources related to this article, please visit the WIREs website.
Structural Effect of Lignans and Sesamol on Polymerization of Soybean Oil at Frying Temperature
Authors: Hwang Hong‐Sik , Winkler‐Moser Jill K. , Liu Sean X.
Published: January 2012

The antipolymerization activity of the lignans including nordihydroguaiaretic acid, (+)‐pinoresinol, (−)‐secoisolariciresinol, enterodiol, and two sesame lignans (sesamol and sesamin), and four model compounds (4‐ethylcatechol, 2‐methoxy‐4‐propylphenol, 4‐methyl‐2,6‐dimethoxyphenol, and piperonyl alcohol) were investigated for soybean oil at frying temperature (180 °C). The heated samples were analyzed by gel‐permeation chromatography for polymerized triacylglycerols and by 1H NMR to monitor the decrease in peak intensities for bisallylic protons and olefinic protons. The heating test results were compared with ability to scavenge the radical 2,2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonic acid) to understand the relationship between radical‐scavenging ability at room temperature and antipolymerization activity at 180 °C. It was found that the antipolymerization activity of a lignan at frying temperature cannot be predicted solely from the radical‐scavenging ability at room temperature. The lignans tested in this research had antipolymerization activity, but it was not as strong as that of 200 ppm tert‐butylhydroquinone (TBHQ) with equivalent of phenolic moiety (0.0012 meq/g). At higher concentrations, however, sesamol, nordihydroguaiaretic acid, and (+)‐pinoresinol had better antipolymerization activity than the legal limit set for TBHQ (200 ppm, 0.0012 meq/g). Therefore, this research showed that by using an appropriate concentration, these natural antioxidants can replace synthetic antioxidants and provide better antioxidation activity.
Sarcopenia and cachexia: the adaptations of negative regulators of skeletal muscle mass
Authors: Sakuma Kunihiro , Yamaguchi Akihiko
Published: January 2012

Recent advances in our understanding of the biology of muscle, and how anabolic and catabolic stimuli interact to control muscle mass and function, have led to new interest in the pharmacological treatment of muscle wasting. Loss of muscle occurs as a consequence of several chronic diseases (cachexia) as well as normal aging (sarcopenia). Although many negative regulators [Atrogin‐1, muscle ring finger‐1, nuclear factor‐kappaB (NF‐κB), myostatin, etc.] have been proposed to enhance protein degradation during both sarcopenia and cachexia, the adaptation of mediators markedly differs among these conditions. Sarcopenic and cachectic muscles have been demonstrated to be abundant in myostatin‐ and apoptosis‐linked molecules. The ubiquitin–proteasome system (UPS) is activated during many different types of cachexia (cancer cachexia, cardiac heart failure, chronic obstructive pulmonary disease), but not many mediators of the UPS change during sarcopenia. NF‐κB signaling is activated in cachectic, but not in sarcopenic, muscle. Some studies have indicated a change of autophagic signaling during both sarcopenia and cachexia, but the adaptation remains to be elucidated. This review provides an overview of the adaptive changes in negative regulators of muscle mass in both sarcopenia and cachexia.
Identification of essential sequences for cellular localization in the muscle‐specific ubiquitin E3 ligase MAFbx/Atrogin 1
Authors: Julie Lagirand-Cantaloube , Sabrina Batonnet-Pichon , Marie-Pierre Leibovitch , Leibovitch Serge A.
Published: January 2012

In skeletal muscle atrophy, upregulation and nuclear accumulation of the Ubiquitin E3 ligase MAFbx is essential for accelerated muscle protein loss, but the nuclear/cytoplasmic shuttling of MAFbx is undefined. Here we found that MAFbx contains two functional nuclear localization signals (NLS). Mutation or deletion of only one NLS induced cytoplasmic localization of MAFbx. We identified a non‐classical NES located in the leucine charged domain (LCD) of MAFbx, which is leptomycin B insensitive. We demonstrated that mutation (L169Q) in LLXXL motif of LCD suppressed cytoplasmic retention of MAFbx. Nucleocytoplasmic shuttling of MAFbx represents a novel mechanism for targeting its substrates and its cytosolic partners in muscle atrophy.
Process quality improvement: An examination of general vs. outcome‐specific climate and practices in hospitals
Authors: Boyer Kenneth K. , Gardner John W. , Schweikhart Sharon
Published: January 2012

Despite numerous efforts to foster quality improvement in healthcare, much of the extant data and research indicate that substantial shortcomings in the delivery of effective and reliable care remain. This research examines both general and outcome‐specific operations management efforts and their impact on delivering quality healthcare. We empirically test a conceptual framework of safety culture that accounts for the use of general quality practices as well as outcome‐specific approaches in light of the general and more focused climates in which those practices are embedded. We utilize structural equation modeling to analyze a unique pairing of primary data from a survey of quality improvement directors and chief nursing officers at 272 hospitals across the U.S. with secondary data on process of care performance publicly reported by the federal government's Center for Medicare and Medicaid Services (CMS). General safety climate and quality practices are found to establish an environment in which outcome‐specific efforts enable process quality improvement. A split‐group SEM analysis highlights significant differences in managing healthcare safety outcomes through climate and practices. In particular, the employment of practices focused on the specific outcome goals is found to relate to higher quality of patient care in smaller hospitals. In contrast, the development of a climate focused on specific outcome goals is found to relate to higher quality of patient care in larger hospitals. These findings suggest alternative approaches for small and large hospitals in the critical effort to improve patient safety and reduce healthcare costs.