bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional organization of V2a‐related locomotor circuits in the rodent spinal cord
Authors: Dougherty Kimberly J. , Kiehn Ole
Published: September 2010

Studies of mammalian locomotion have been greatly facilitated by the use of the isolated rodent spinal cord preparation that retains the locomotor circuits needed to execute the movement. Physiological and molecular genetic experiments in this preparation have started to unravel the basic circuit organization responsible for walking in mammals. Here, we review these experiments with a focus on the functional role of excitatory V2a interneurons in the mammalian locomotor network. With regard to these neurons and other network structures we also discuss similarities and differences between the mammalian walking central pattern generator (CPG) and the fish swimming CPG.
Synaptic integration of rhythmogenic neurons in the locomotor circuitry: the case of Hb9 interneurons
Authors: Ziskind‐Conhaim Lea , Mentis George Z. , Wiesner Eric P. , Titus David J.
Published: September 2010

Innovative molecular and genetic techniques have recently led to the identification of genetically defined populations of ipsilaterally projecting excitatory interneurons with probable functions in the rhythm‐generating kernel of the central pattern generators (CPGs). The role of interneuronal populations in specific motor function is determined by their synaptic inputs, intrinsic properties, and target neurons. In this review we examine whether Hb9‐expressing interneurons (Hb9 INs) fulfill a set of criteria that are the hallmarks of rhythm generators in the locomotor circuitry. Induced locomotor‐like activity in this distinct population of ventral interneurons is in phase with bursts of motor activity, raising the possibility that they are part of the locomotor generator. To increase our understanding of the integrative function of Hb9 INs in the locomotor CPG, we investigated the cellular mechanisms underlying their rhythmic activity and examined the properties of synaptic inputs from low‐threshold afferents and possible synaptic contacts with segmental motoneurons. Our findings suggest that the rhythmogenic Hb9 INs are integral components of the sensorimotor circuitry that regulate locomotor‐like activity in the spinal cord.
Chemical Characterization of Tomato Juice Fermented with Bifidobacteria
Authors: Koh Jong‐Ho , Kim Youngshik , Oh Jun‐Hyun
Published: September 2010

Abstract:  The objective of this research was to characterize the chemical properties of tomato juice fermented with bifidobacterial species. Tomato juice was prepared from fresh tomatoes and heated at 100 °C prior to fermentation. Bifidobacterium breve, Bifidobacterium longum, and Bifidobacterium infantis were inoculated in tomato juice and kept at 35 to 37 °C for up to 6 h. Fructooligosaccharide (FOS) was added to tomato juice prior to fermentation. The analyses for brix, total titratable acidity (TTA), pH, color, and lycopene content were conducted to characterize tomato juices fermented with bifidobacterial species. Heat treatment of tomato juice did not cause any significant changes in brix, pH, and TTA. Only the redness of tomato juice was significantly increased, as the heating time increased to 30 min. The tomato juices fermented with B. breve and B. longum exhibited significant decreases in pH (3.51 and 3.80, respectively) and significant increases in TTA (13.50 and 12.50, respectively) (P < 0.05). B. infantis did not cause any significant change in the chemical properties of tomato juice. The addition of FOS further improved the fermentation of tomato juice by bifidobacterial species. The lycopene contents of tomato juice were significantly increased from 88 to 113 μg/g by heat treatment at 100 °C (P < 0.05), however did not exhibit any significant change after fermentation with bifidobacterial species.
Effects of Carbon Dioxide and Ozone Treatments on the Volatile Composition and Sensory Quality of Dry‐Cured Ham
Authors: Sekhon R.K. , Schilling M.W. , Phillips T.W. , Aikins R.M.J. , Hasan M.M. , Nannapaneni R. , Mikel W.B.
Published: September 2010

Abstract:  Randomized complete block designs with 3 replications were utilized to evaluate the effects of carbon dioxide (CO2) (0% at 96 h, 60% at 48 h, and 60% at 96 h) and ozone (O3) (0 and 175 ppm for 48 h) on the volatile flavor compound concentrations in dry‐cured ham. Minimal differences existed in the presence and concentration of aroma active compounds in both CO2 and O3 fumigated hams but phenols were slightly more prevalent (P < 0.05) in the CO2 treatments and oxidation compounds were slightly elevated (P < 0.05) in the ozone treated samples when compared to the control. Triangle tests (n = 54 and 56) indicated that consumers could not discern (P > 0.75) between the control hams and the hams that were fumigated with CO2 and O3, respectively. This study revealed that there were minimal aroma/flavor differences among the ham treatments between 0 and 60% CO2 for 96 h; and also between 0 and 175 ppm O3.
Formation of Elastic Whey Protein Gels at Low pH by Acid Equilibration
Authors: Vardhanabhuti Bongkosh , Khayankan Worarat , Foegeding E. Allen
Published: September 2010

Abstract:  Whey protein gels have a weak/brittle texture when formed at pH ≤ 4.5, yet this pH is required to produce a high‐protein, shelf‐stable product. We investigated if gels could be made under conditions that produced strong/elastic textural properties then adjusted to pH ≤ 4.5 and maintain textural properties. Gels were initially formed at 15% w/w protein (pH 7.5). Equilibration in acid solutions caused gel swelling and lowered pH because of the diffusion of water and H+ into the gels. The type and concentration of acid, and presence of other ions, in the equilibrating solutions influenced pH, swelling ratio, and fracture properties of the gels. Swelling of gels decreased fracture stress (because of decreased protein network density) but caused little change to fracture strain, thus maintaining a desirable strong/elastic fracture pattern. We have shown that whey protein isolate gels can be made at pH ≤ 4.5 with a strong/elastic fracture pattern and the magnitude of this pattern can be altered by varying the acid type, acid concentration, pH of equilibrating solution, and equilibrating time.

Practical Application:  Low‐pH shelf‐stable whey protein gels having the strong/elastic texture can be made by forming gels at high pH and equilibrating in acid solutions. Acid equilibration causes the gel to swell and lower the gel pH. Moreover, gel properties can be altered by varying the acid type, acid concentration, pH of equilibrating solution, and equilibrating time.
FT‐NIR Spectroscopy for the Quality Characterization of Apricots (Prunus Armeniaca L.)
Authors: Berardinelli Annachiara , Cevoli Chiara , Silaghi Florina Aurelia , Fabbri Angelo , Ragni Luigi , Giunchi Alessandro , Bassi Daniele
Published: September 2010

Abstract:  The nondestructive assessment of apricot fruit quality (Bora cultivar) was carried out by means of FT‐NIR reflectance spectroscopy in the wavenumber range 12000 to 4000 cm−1. Samples were harvested at four different ripening stages and scanned by a fiber optical probe immediately after harvesting and after a storage of 3 d (2 d at 4 °C and 1 d at 18 °C); the flesh firmness (FF), the soluble solids content (SSC), the acidity (A), and the titratable acidity (malic and citric acids) were then measured by destructive methods. Soft independent modeling of class analogy (SIMCA) analysis was used to classify spectra according to the ripening stage and the storage: partial least squares regression (PLS) models to predict FF, SSC, A, and the titratable acidity were also set‐up for both just harvested and stored apricots. Spectral pretreatments and wavenumber selections were conducted on the basis of explorative principal component analysis (PCA). Apricot spectra were correctly classified in the right class with a mean classification rate of 87% (range: 80% to 100%). Test set validations of PLS models showed R2 values up to 0.620, 0.863, 0.842, and 0.369 for FF, SSC, A, and the titratable acidity, respectively. The best models were obtained for the SSC and A and are suitable for rough screening; a lower power prediction emerged for the other maturity indices and the relative predictive models are not recommended.

Practical Application: The results of the study could be used as a tool for the assessment of the ripening stage during the harvest and the quality during the postharvest storage of apricot fruits.
Distribution of Stable Free Radicals among Amino Acids of Isolated Soy Proteins
Authors: Lei Qingxin , Liebold Christopher M. , Boatright William L. , Shah Jahan M.
Published: September 2010

Abstract:  Application of deuterium sulfide to powdered isolated soy proteins (ISP) was used to quench stable free radicals and produce a single deuterium label on amino acids where free radicals reside. The deuterium labels rendered increases of isotope ratio for the specific ions of radical‐bearing amino acids. Isotope ratio measurements were achieved by gas chromatography/mass spectrometry (GC/MS) analyses after the amino acids were released by acidic hydrolysis and converted to volatile derivatives with propyl chloroformate. The isotope enrichment data showed the stable free radicals were located on Ala, Gly, Leu, Ile, Asx (Asp+Asn), Glx (Glu+Gln), and Trp but not on Val, Pro, Met, Phe, Lys, and His. Due to the low abundance of Ser, Thr, and Cys derivatives and the impossibility to accurately measure their isotope ratios, the radical bearing status for these amino acids remained undetermined even though their derivatives were positively identified from ISP hydrolysates. The relative isotope enrichment for radical‐bearing amino acids Ala, Gly, Leu, Ile, Asx (Asp+Asn), Glx (Glu+Gln), and Trp were 8.67%, 2.96%, 2.90%, 3.94%, 6.03%, 3.91%, and 21.48%, respectively. Isotope ratio increase for Tyr was also observed but further investigation revealed such increase was mainly from nonspecific deuterium–hydrogen exchange not free radical quenching. The results obtained from the present study provide important information for a better understanding of the mechanisms of free radical formation and stabilization in “dry” ISP.
SCIENTIFIC AND CLINICAL: In this issue – September 2010
Authors: Jackson AE
Published: September 2010

Agricultural shows and communicable disease transmission in poultry · Capsule endoscopy in horse small intestine · Acute lameness from a bone metastasis in a horse · Tidal breathing flow volume loop in dogs with tracheal masses · Intracranial meningioma and facial myokymia in a dog · Caudal epidural flank anaesthesia using multiport catheters in cattle · Needle‐free vaccination in sheep · Smoking vets in Australia
Assessment of the risks of communicable disease transmission through the movement of poultry exhibited at agricultural shows in New South Wales
Authors: Dusan F , Toribio J‐A , East IJ
Published: September 2010

Objective To assess biosecurity practices in the fancy poultry show sector that would influence the establishment and spread of exotic diseases in poultry in New South Wales.

Design A cross‐sectional survey of 105 fancy poultry exhibitors at seven agricultural shows.

Procedure Exhibitors were interviewed about biosecurity practices on their farms and their knowledge of exotic diseases. Poultry stewards at 18 shows were interviewed about biosecurity practices at their shows.

Results Although many exhibitors travelled only short distances to attend shows, some exhibitors attended up to 30 shows per year and travelled interstate to exhibit poultry. A network diagram revealed extensive connections and interactions of poultry throughout the eastern half of NSW. Five of 18 shows included cash sales without any record of purchasers; 46% of exhibitors reintroduced exhibited birds back into their flocks without a quarantine period; and 16% failed to wash cages used to transport the birds. There was a general awareness that exhibition of birds posed a risk to flock health, but knowledge of avian influenza and practices that could be adopted to minimise the risk of disease introduction was limited.

Conclusions The factors that could assist the establishment and spread of exotic diseases in poultry in NSW include the mixing of birds at shows, inadequate recording of exhibitor details at shows, inadequate biosecurity practices when reintroducing exhibited poultry back into flocks, cash sales associated with shows that did not include the collection of purchaser details, and inadequate identification of birds.
Construction of vectors for inducible and constitutive gene expression in Lactobacillus
Authors: Duong Tri , Miller Michael J. , Barrangou Rodolphe , Azcarate‐Peril M. Andrea , Klaenhammer Todd R.
Published: September 2010

Microarray analysis of the genome of Lactobacillus acidophilus identified a number of operons that were differentially expressed in response to carbohydrate source or constitutively expressed regardless of carbohydrate source. These included operons implicated in the transport and catabolism of fructooligosaccharides (FOS), lactose (lac), trehalose (tre) and genes directing glycolysis. Analysis of these operons identified a number of putative promoter and repressor elements, which were used to construct a series of expression vectors for use in lactobacilli, based on the broad host range pWV01 replicon. A β‐glucuronidase (GusA3) reporter gene was cloned into each vector to characterize expression from each promoter. GUS reporter assays showed FOS, lac and tre based vectors to be highly inducible by their specific carbohydrate and repressed by glucose. Additionally, a construct based on the phosphoglycerate mutase (pgm) promoter was constitutively highly expressed. To demonstrate the potential utility of these vectors, we constructed a plasmid for the overexpression of the oxalate degradation pathway (Frc and Oxc) of L. acidophilus NCFM. This construct was able to improve oxalate degradation by L. gasseri ATCC 33323 and compliment a L. acidophilus oxalate‐deficient mutant. Development of these expression vectors could support several novel applications, including the expression of enzymes, proteins, vaccines and biotherapeutics by intestinal lactobacilli.
Long‐term results of bilateral congenital cataract treated with early cataract surgery, aphakic glasses and secondary IOL implantation
Authors: Kim Dong‐Hyun , Kim Jeong Hun , Kim Seong‐Joon , Yu Young Suk
Published: September 2010

Purpose:  To evaluate the long‐term visual outcome after early surgery of bilateral dense congenital cataracts, aphakic correction with glasses and secondary intraocular lens (IOL) implantation around 2 years of age.

Methods:  The medical records of paediatric patients who underwent cataract extraction, aphakic correction and secondary IOL implantation from 1993 to 2004 at Seoul National University Children’s Hospital were reviewed retrospectively. Age at secondary IOL implantation, axial length (AL), best corrected visual acuity (BCVA), refractive error, ocular alignment, stereopsis, and postoperative ocular complications were recorded.

Results:  Thirty‐seven paediatric bilateral pseudophakic patients were identified with a mean follow‐up period of 81.4 months. Best corrected visual acuity of 20/40 or better were attained in 44.0% of eyes, and the median BCVA was 20/50. Preoperative factors associated with poor visual prognosis included cataract surgery after 8 weeks of age, interocular AL difference of 0.5 mm or more, and glaucoma. Amblyopic eyes showed more myopic change compared to fellow eyes. Good or moderate binocular function was achieved in 18.9% of all patients. Incidences of strabismus, glaucoma, posterior capsular opacity formation were 46.0%, 32.4% and 4.0%, respectively.

Conclusion:  Good postoperative BCVA and binocular function were achieved in most healthy children with bilateral dense congenital cataract and no posterior segment pathology. Early cataract surgery, aphakic correction with glasses and secondary IOL implantation around 2 years of age appears to be appropriate methods.
The new heart of your brand: Transforming your business through customer experience
Authors: Moore Carol
Published: September 2010

Design matters. But design alone is not enough. In both the digital and 3‐D worlds, value—and the resulting business success—is not in objects, but in the experience that surrounds objects. In this context, Carol Moore offers insights into the creation of powerful experiences: understand brand intent; engage customer emotions; invest in what is valued, not in what is possible; coordinate interactions to generate a seamless reality; and ensure consistency.
In Situ Microindentation for Determining Local Subchondral Bone Compressive Modulus
Authors: Gardner-Morse Mack G. , Tacy Nelson J. , Beynnon Bruce D. , Roemhildt Maria L.
Published: September 2010

Alterations to joint tissues, including subchondral bone, occur with osteoarthritis. A microindentation technique was developed to determine the local compressive modulus of subchondral bone. This test, in conjunction with a cartilage indentation test at the same location, could evaluate changes of these material properties in both tissues. The accuracy of the technique was determined by applying it to materials of known moduli. The technique was then applied to rat tibial plateaus to characterize the local moduli of the subchondral bone. An established nanoindentation method was adopted to determine the modulus of subchondral bone following penetration of the overlying articular cartilage. Three cycles of repeated loadings were applied (2.452 N, 30 s hold). The slope of the load-displacement response during the unloading portion of the third cycle was used to measure the stiffness. Indentation tests were performed on two polyurethane foams and polymethyl-methacrylate for validation (n=15). Regression analysis was used to compare the moduli with reference values. Subchondral bone moduli of tibial plateaus from Sprague-Dawley rats (n=5) were measured for central and posterior locations of medial and lateral compartments. An analysis of variance was used to analyze the effects of compartment and test location. The measured moduli of the validation materials correlated with the reference values (R2=0.993, p=0.05). In rat tibial plateaus, the modulus of the posterior location was significantly greater than the center location (4.03±1.00 GPa and 3.35±1.16 GPa respectively, p=0.03). The medial compartment was not different from the lateral compartment. This method for measuring the subchondral bone in the same location as articular cartilage allows studies of the changes in these material properties with the onset and progression of osteoarthritis.
Effects of Anterior Shear Displacement Rate on the Structural Properties of the Porcine Cervical Spine
Authors: Gallagher Kaitlin M. , Howarth Samuel J. , Callaghan Jack P.
Published: September 2010

While the individual tissues of the vertebral joint demonstrate viscoelastic properties, the global viscoelastic properties of the lumbar vertebral joint are not well established. This study investigated how changes in displacement rate influenced the mechanical response of the porcine cervical spine (a surrogate or model for the human lumbar spine) exposed to acute anterior shear failure loading. Thirty porcine cervical spine specimens (15 C3-C4 and 15 C5-C6) were placed under a 1600 N compressive load and subsequently loaded in anterior shear to failure at one of three randomly assigned displacement rates (1 mm/s, 4 mm/s, or 16 mm/s). Ultimate anterior shear force, ultimate displacement, average stiffness, and energy stored until failure were calculated. Load rate in the elastic region was also calculated to compare the load rates used in this study to those used in previous studies. Changes in displacement rate affected the C3-C4 and C5-C6 specimens differently. C5-C6 specimens tested at 16 mm/s had an ultimate force that was 28% and 23% higher than at 1 (p=0.0215) and 4 mm/s (p=0.0461), respectively. The average stiffness to failure of the C5-C6 specimens tested at 16 mm/s was 52% higher than at 4 mm/s (p=0.0289). No such differences were found for the C3-C4 specimens. An increase in the anterior shear displacement rate did not necessarily demonstrate viscoelasticity of the vertebral joint. Specimen intervertebral levels were affected differently by changes in anterior shear displacement rate, which may have been a result of anatomical and postural differences between the two levels. Future studies should further investigate the effect of displacement rate on the spine and the inconsistencies between different specimen levels.
Outflow Conditions for Image-Based Hemodynamic Models of the Carotid Bifurcation: Implications for Indicators of Abnormal Flow
Authors: Morbiducci Umberto , Gallo Diego , Massai Diana , Consolo Filippo , Ponzini Raffaele , Antiga Luca , Bignardi Cristina , Deriu Marco A. , Redaelli Alberto
Published: September 2010

Computational fluid dynamics (CFD) models have become very effective tools for predicting the flow field within the carotid bifurcation, and for understanding the relationship between local hemodynamics, and the initiation and progression of vascular wall pathologies. As prescribing proper boundary conditions can affect the solutions of the equations governing blood flow, in this study, we investigated the influence to assumptions regarding the outflow boundary conditions in an image-based CFD model of human carotid bifurcation. Four simulations were conducted with identical geometry, inlet flow rate, and fluid parameters. In the first case, a physiological time-varying flow rate partition at branches along the cardiac cycle was obtained by coupling the 3D model of the carotid bifurcation at outlets with a lumped-parameter model of the downstream vascular network. Results from the coupled model were compared with those obtained by imposing three fixed flow rate divisions (50/50, 60/40, and 70/30) between the two branches of the isolated 3D model of the carotid bifurcation. Three hemodynamic wall parameters were considered as indicators of vascular wall dysfunction. Our findings underscore that the overall effect of the assumptions done in order to simulate blood flow within the carotid bifurcation is mainly in the hot-spot modulation of the hemodynamic descriptors of atherosusceptible areas, rather than in their distribution. In particular, the more physiological, time-varying flow rate division deriving from the coupled simulation has the effect of damping wall shear stress (WSS) oscillations (differences among the coupled and the three fixed flow partition models are up to 37.3% for the oscillating shear index). In conclusion, we recommend to adopt more realistic constraints, for example, by coupling models at different scales, as in this study, when the objective is the outcome prediction of alternate therapeutic interventions for individual patients, or to test hypotheses related to the role of local fluid dynamics and other biomechanical factors in vascular diseases.
A Neurogenetic Approach to a Multiobjective Design Optimization of Spinal Pedicle Screws
Authors: Chao Ching-Kong , Lin Jinn , Putra Sandy Tri , Hsu Ching-Chi
Published: September 2010

A pedicle screw fixation has been widely used to treat spinal diseases. Clinical reports have shown that the weakest part of the spinal fixator is the pedicle screw. However, previous studies have only focused on either screw breakage or screw loosening. There have been no studies that have addressed the multiobjective design optimization of the pedicle screws. The multiobjective optimization methodology was applied and it consisted of finite element method, Taguchi method, artificial neural networks, and genetic algorithms. Three-dimensional finite element models for both the bending strength and the pullout strength of the pedicle screw were first developed and arranged on an L25 orthogonal array. Then, artificial neural networks were used to create two objective functions. Finally, the optimum solutions of the pedicle screws were obtained by genetic algorithms. The results showed that the optimum designs had higher bending and pullout strengths compared with commercially available screws. The optimum designs of pedicle screw revealed excellent biomechanical performances. The neurogenetic approach has effectively decreased the time and effort required for searching for the optimal designs of pedicle screws and has directly provided the selection information to surgeons.
Design of a Free-Floating Polycarbonate-Urethane Meniscal Implant Using Finite Element Modeling and Experimental Validation
Authors: Elsner Jonathan J. , Portnoy Sigal , Zur Gal , Guilak Farshid , Shterling Avi , Linder-Ganz Eran
Published: September 2010

The development of a synthetic meniscal implant that does not require surgical attachment but still provides the biomechanical function necessary for joint preservation would have important advantages. We present a computational-experimental approach for the design optimization of a free-floating polycarbonate-urethane (PCU) meniscal implant. Validated 3D finite element (FE) models of the knee and PCU-based implant were analyzed under physiological loads. The model was validated by comparing calculated pressures, determined from FE analysis to tibial plateau contact pressures measured in a cadaveric knee in vitro. Several models of the implant, some including embedded reinforcement fibers, were tested. An optimal implant configuration was then selected based on the ability to restore pressure distribution in the knee, manufacturability, and long-term safety. The optimal implant design entailed a PCU meniscus embedded with circumferential reinforcement made of polyethylene fibers. This selected design can be manufactured in various sizes, without risking its integrity under joint loads. Importantly, it produces an optimal pressure distribution, similar in shape and values to that of natural meniscus. We have shown that a fiber-reinforced, free-floating PCU meniscal implant can redistribute joint loads in a similar pattern to natural meniscus, without risking the integrity of the implant materials.
Epitaxial growth of germanium on silicon using a Gd2O3/Si (111) crystalline template
Authors: Niu G. , Largeau L. , Saint-Girons G. , Vilquin B. , Cheng J. , Mauguin O. , Hollinger G.
Published: September 2010

This work presents a study of the epitaxial growth of Ge on Si (111) using a Gd2O3 crystalline template. A smooth two-dimensional Ge layers is obtained from the coalescence of initially three-dimensional Ge islands grown in the Volmer–Weber mode. Ge takes its bulk lattice parameter at the very early stages of its growth. A detailed x-ray pole figure analysis reveals that the epitaxial relationship between the layers and the Si substrate is [1–10]Ge(111)∥[−110]Gd2O3(111)∥[1–10]Si(111) and that microtwins are formed in the Ge layer.
Cosputtered composition-spread reproducibility established by high-throughput x-ray fluorescence
Authors: Gregoire John M. , Dale Darren , Kazimirov Alexander , DiSalvo Francis J. , Bruce van Dover R.
Published: September 2010

We describe the characterization of sputtered yttria-zirconia composition spread thin films by x-ray fluorescence (XRF). We also discuss our automated analysis of the XRF data, which was collected in a high throughput experiment at the Cornell High Energy Synchrotron Source. The results indicate that both the composition reproducibility of the library deposition and the composition measurements have a precision of better than 1 atomic percent.
Preparation and topography analysis of randomly textured glass substrates
Authors: Bunte Eerke , Zhang Wendi , Hüpkes Jürgen
Published: September 2010

Randomly textured glass sheets in combination with a transparent conductive layer are promising as front contacts for silicon based thin-film solar cells. The authors have developed a novel method to create randomly textured glass surfaces. For the fabrication a wet chemically textured zinc oxide (ZnO) film is used as three dimensional etch mask and its surface topography is transferred to the glass substrate by ion beam etching. The typical texture of the sputtered and etched ZnO film exhibits craterlike features, which can be tuned by a variation of the initial ZnO film thickness and the etching time. Thus, the surface features of the resulting rough glass can be varied within a wide range. Its topography exhibits a maximum root mean square roughness of more than 200 nm with a lateral correlation length around 1500 nm. Microcrystalline silicon solar cells on the textured glass substrates show an increase of the short circuit current density by 36% compared to cells on flat glass. This proves the improvement of the so-called “light-trapping” effect in the solar cells by the glass texture.
The 2008 Declaration of Helsinki: some reflections
Authors: Giordano Simona
Published: September 2010

This paper reflects on some amendments to the Declaration of Helsinki in 2008. It focuses on former paragraphs 5 (now 6) and 19 (now 17). Paragraph 5 suggested that the wellbeing of research participants should take precedence over the interests of science and society. Paragraph 6 now proposes that it should take precedence over all other interests. Paragraph 19, and the new paragraph 17, suggest that research involving the members of a disadvantaged population is only justified if the clinical trial is likely to benefit them. In both cases, the recommendation is that the interests of the research subjects should prevail over the interests of third parties. This paper assesses the plausibility of these statements, and in order to do so, considers debates on the moral duty to participate in biomedical research. It is argued that, even if seen in the context of the Declaration as a whole, the statements contained in these paragraphs risk offering a misleading portrait of science and risk eroding some of the ethical principles that should form the basis of a satisfactory shared life, such as altruism and responsibility for our fellows.
Trophic interactions affecting a key ecosystem component: a multistage analysis of the recruitment of the Barents Sea capelin (Mallotus villosus)
Authors: Hjermann Dag Øystein , Bogstad Bjarte , Dingsør Gjert Endre , Gjøsæter Harald , Ottersen Geir , Eikeset Anne Maria , Stenseth Nils Christian
Published: September 2010

The Barents Sea stock of capelin ( Mallotus villosus ) has suffered three major collapses (>90% reduction) since 1985 due to recruitment failures. As capelin is a key species in the area, these population collapses have had major ecosystem consequences. By analysing data on spawner biomass and three recruitment stages (larvae, 0-group, and 1-year-olds), we suggest that much of the recruitment failures are caused by predation from herring ( Clupea harengus ) and 0-group and adult Northeast Arctic cod ( Gadus morhua ). Recruitment is furthermore positively correlated with sea temperatures in winter and spring. Harvesting of maturing capelin on their way to the spawning grounds reduced the abundance of larvae significantly, but this reduction to a large extent is compensated for later in life, as mortality is strongly density-dependent between the larval stage and age 1. Altogether, our study indicates a very high importance of trophic interactions, consistent with similar findings in other high-latitude marine ecosystems.
Selenium incorporation in fish otoliths: effects of selenium and mercury from the water
Authors: Lochet Aude , Limburg Karin E. , Rudstam Lars , Montesdeoca Mario
Published: September 2010

To study fish migration using otolith microchemistry, it is important to understand the relationship between elements in the otoliths and in the surrounding water, including potential interactions with other elements. Selenium (Se) is a trace element with strong affinity for mercury (Hg). To test if Se is a reliable tracer for fish migration, the effects of dissolved Se and Hg concentrations on Se incorporation in fish otoliths were investigated experimentally. Brown bullheads ( Ameiurus nebulosus ) were reared in waters spiked with various concentrations of inorganic Se and Hg. Otolith Se:Ca increased nonlinearly with dissolved Se concentrations as there was no significant difference between fish reared in low and medium [Se] waters (Se:Ca for low [Se] waters, 7.64 × 10−6; medium, 6.59 × 10−6; high, 1.24 × 10−5). Our study also provided the first evidence of a negative effect of Hg on Se incorporation into otoliths (p = 0.01), a phenomenon most evident in high [Se] waters. Because of the influence of Hg, caution should be taken when inferring fish migration based on Se.
Finite element investigations of granular material behaviour during cyclic wall shearing under a constant normal stiffness condition
Authors: Tejchman J.
Published: September 2010

The behaviour of dry and cohesionless sand during quasi-static cyclic wall shearing under a constant normal stiffness (CNS) condition was studied. Numerical calculations were carried out using a finite element method based on a hypoplastic constitutive model extended by micropolar quantities: rotations, curvatures, and couple stresses. The mean grain diameter was used as the characteristic length of the microstructure. The constitutive model takes into account the effects of pressure, void ratio, and direction of deformation rate on the material’s behaviour. Calculations were performed for several shear cycles in a direct wall shear tester. The initial void ratio, mean grain diameter of sand, and vertical normal stiffness were varied. The numerical results with medium density sand were compared with corresponding laboratory tests.
Upper-bound approach for analysis of cantilever retaining walls
Authors: Vrecl Kojc H. , Trauner L.
Published: September 2010

The proposed method for the analysis of cantilever retaining walls is based on ultimate limit states, but in contrast to other methods, which are recognized worldwide, also considers the condition of vertical force equilibrium, which includes the wall unit weight and the vertical component of the soil–structure interaction. The two-dimensional analytical model with polygonal soil pressure distribution is based on two new characteristics: the parameter α and the passive pressure coefficient at the embedment depth, Kb. The kinematic approach of limit analysis is used to examine the limit equilibrium state of the cantilever retaining wall according to soil properties and other loadings. The failure mechanism, composed of a classical determination of the passive pressure in the embedded part of the wall and a kinematically admissible velocity field at the retained side of the wall, estimates the limiting value of the passive earth pressure at the embedment depth. The advantage of the proposed method is that it enables the design of more slender cantilever retaining walls, at which the comparable level of safety for geotechnical and structural bearing capacity limit states is reached, which is the basic condition for safe design of retaining structures.
A factored strength approach for the limit states design of geotechnical structures
Authors: Callisto Luigi
Published: September 2010

This paper discusses the implications of an approach to the limit states design of geotechnical structures in which the soil strength parameters are factored, as is the one contained in the European construction code. It is shown that a factored strength approach has very different implications for the two customary types of geotechnical analyses; namely, the study of plastic mechanisms and interaction analyses. The relationship between partial safety factors and the reliability of a system is highlighted first, with the aid of approximate reliability calculations relative to two example problems. It is then demonstrated that the method of factoring the soil strength may be regarded as an effective way to assess the distance of a structure from the activation of a plastic mechanism, and to relate this distance to a conventional measure of its reliability. Using the same examples, it is argued that the procedure of factoring the soil strength parameters is not appropriate for the evaluation of the internal forces in structural elements: most of the soil–structure interaction analyses are nonlinear and, at least partly, empirically based. The insertion of unrealistic parameters, such as the factored strength properties, in a complex calculation may produce ambiguous and uncontrollable results.
Large-scale geomechanical model testing of an underground cavern group in a true three-dimensional (3-D) stress state
Authors: Zhu W. S. , Zhang Q. B. , Zhu H. H. , Li Y. , Yin J.-H. , Li S. C. , Sun L. F. , Zhang L.
Published: September 2010

The stability of a large cavern group at great depth is discussed on the basis of large-scale three-dimensional (3-D) geomechanical model tests and numerical simulations. The model tests are described in detail. Improvements in the tests were made in terms of experimental techniques and advanced measurement methods. The model tests utilized active loading on six sides of a rock mass in a true 3-D stress state. During the model construction, precast blocks were fabricated and monitoring holes were defined prior to test initiation. Newly developed combination ball-sliding walls were installed on each of the major loading surfaces to reduce the friction induced by model deformation. A unique grouting and installation technique employing prestressed cables was adopted in the tests. A digital photogrammetric technique, displacement sensing bars using fiber Bragg grating (FBG) technology, and mini multipoint extensometers were developed for measuring deformation. Overloading tests were then conducted for different overburden depths, and 3-D numerical analyses were performed to simulate the testing procedures. Conclusions regarding the stability of the cavern group were developed based on a comparison between the experimental and numerical results.
A quasi-classical trajectory (QCT) study of the H + OF reaction stereodynamics
Authors: Zhao Dan , Zhang Tian Yu , Chu Tian Shu
Published: September 2010

Based on the global three-dimensional adiabatic potential surface of the 13A′ excited electronic state (J. Chem. Phys. 2005, 123, 114310) of the OHF system, we investigated the H + OF → OH + F/HF + O reaction stereodynamics by using the quasi-classical trajectory (QCT) method. The four polarization-dependent differential cross sections (PDDCSs) and the three angular distributions P(θr), P([Formula: see text]), P(θr, [Formula: see text]) were calculated at a low collision energy of 0.48 eV for both product channels. The results indicated that the products are backward-scattering on the triplet state, and the product rotational angular momenta are aligned or oriented. Moreover, there is a remarkable difference between the polarization behaviors of the two product channels. Product orientation exhibited by the OH + F channel is found to be absent in the HF + O channel at this collision energy albeit the latter shows stronger alignment along the direction perpendicular to the reagent relative velocity k than OH + F.
Iron(II) complexes containing thiophene-substituted “bispicen” ligands — Spin-crossover, ligand rearrangements, and ferromagnetic interactions
Authors: Cheng Haojin , Djukic Brandon , Jenkins Hilary A. , Gorelsky Serge I. , Lemaire Martin T.
Published: September 2010

The synthesis and characterization of three new tetradentate “bispicen-type” ligands containing a substituted thiophene heterocycle are described [2,5-thienyl substituents = H (7), Ph (8), or 2-thienyl (9)]. Iron(II) bis(thiocyanate) coordination complexes containing 7–9 were prepared, and the electronic and variable-temperature magnetic properties of complexes containing 7 (10) and 9 (12) are described. Complex 10 features a gradual and incomplete spin crossover in the solid state, and 12 remains high-spin over the entire temperature range. Complex 11 is extremely unstable and rearranges to another iron(II) complex (13), which was structurally characterized. The temperature-dependent magnetic properties of 13 are described as a one-dimensional ferromagnetic chain, with interchain antiferromagnetic interactions and (or) zero-field splitting dominant at low temperatures. The magnetic analysis is corroborated by the molecular packing and density functional theory calculations, which suggest intermolecular interactions between coordinated thiocyanate ligands bearing a significant spin density.
Novel β-galactosidase-specific O2-glycosylated diazeniumdiolate probes
Authors: Bedell Barry J. , Bohle D. Scott , Chua Zhijie , Czerniewski Alexander , Evans Alan C. , Mzengeza Shadreck
Published: September 2010

Three β-galactosidase-specific nitric-oxide-releasing diazeniumdiolate conjugated probes were prepared as a prelude to studies of new potential molecular MRI imaging agents. A glycosylated derivative, 2e, designed to be trafficked across cell membranes, was also prepared. We report, in detail, the synthesis and characterization of these probes. In addition, the release of diazeniumdiolate from the probes by β-galactosidase-catalyzed hydrolysis was used to estimate their efficacy as serum-stable, specific NO donors.
Factors controlling litter production in a large Mediterranean river floodplain forest
Authors: González Eduardo , Muller Etienne , Gallardo Belinda , Comín Francisco Antonio , González-Sanchis María
Published: September 2010

Although litter production is an essential floodplain forest function, the drivers and their relative importance remain largely unknown, especially in semi-arid rivers. The influence of forest structure, flooding regime, soil conditions, and litterfall chemistry (a total of 17 variables) on spatial variability of litter production within the Middle Ebro River floodplain forests (northeastern Spain) was examined by monitoring litterfall in 12 forest plots in 2007. Linear mixed effects (LME) models, using stem density (SD), river distance (RD) (or soil total organic C (TOC)), and soil total P (TP) as independent predictors, explained 51% of the variance in litter production, while an alternative LME model using SD and P use efficiency (P-NUE) explained 40%. In particular, litter increased with SD and TP and decreased with RD, P-NUE, and TOC. Based on these results, P limitation appears to be controlling litter production in a rather dry hydrological regime. We hypothesized that a deficient sediment input at the plot scale (especially in the outer floodplain), with flood quality (overbank flooding, ground-water seepage, ponding) being a greater determinant than quantity (flood duration, water table levels), might ultimately be responsible for the spatial variability observed in litter production.
The impacts of changes in federal timber harvest on forest carbon sequestration in western Oregon
Authors: Im Eun Ho , Adams Darius M. , Latta Gregory S.
Published: September 2010

This study examines the potential impacts of changes in federal timber harvest, acting through regional log markets, on the sequestration of carbon in forests and forest products in western Oregon. We construct a dynamic model of the region’s log markets in which market prices, log consumption at mills, and timber harvests and timber inventories on private, federal, and state forests are endogenous. Absent any policies regulating forest carbon sequestration, simulations show that regional carbon flux in forests and forest products would gradually decline as federal harvest rises from recent historical levels. If regional forest carbon flux were constrained to meet some minimum target, however, projections indicate that there would be opportunities for substituting carbon sequestration between federal and nonfederal lands through coordination of harvests across ownerships. We find that relatively small reductions in average private harvest could offset substantial losses of carbon flux on federal timberlands caused by increased federal harvest. One mechanism for achieving the changes needed in private harvest to meet a regional carbon flux target would be a carbon tax/subsidy program or a carbon offset market. For example, if federal owners offered timber for sale equal to the maximum sustainable level under the Northwest Forest Plan, our analysis indicates that a carbon price of roughly $US 19 per tonne of carbon would be sufficient to induce private owners to undertake the harvest and management modifications necessary to maintain regional forest carbon flux at its level in the early 2000s.
Meta-analysis of fertilization experiments indicates multiple limiting nutrients in northeastern deciduous forests
Authors: Vadeboncoeur Matthew A.
Published: September 2010

It is widely accepted that N limits primary production in temperate forests, although colimitation by N and P has also been suggested, and on some soils, Ca and base cations are in short supply. I conducted a meta-analysis to assess the strength of existing experimental evidence for limitation of primary production by N, P, and Ca in hardwood forests of the northeastern United States and southeastern Canada using data from 35 fertilization experiments in deciduous forests on glaciated soils across the region. There is strong evidence for N limitation (formal meta-analysis weighted mean response ratio = 1.51, p < 0.01; simple mean = 1.42, p < 0.001). Forest productivity also tended to increase with additions of P (simple mean = 1.15, p = 0.05) and Ca (simple mean = 1.36, p < 0.001). Across all treatments, 85% of response ratios were positive. Multiple-element additions had larger effects than single elements, but factorial experiments showed little evidence of synergistic effects between nutrient additions. Production responses correlated positively with the rate of N fertilization, but this effect was reduced at high rates of ambient N deposition.
Do harvest methods and soil type impact the regeneration and growth of black spruce stands in northwestern Quebec?
Authors: Lafleur Benoit , Paré David , Fenton Nicole J. , Bergeron Yves
Published: September 2010

Machinery traffic restrictions during forest harvest have been adopted to minimize soil damage and protect tree regeneration. However, this practice is questioned for paludifying black spruce ( Picea mariana (Mill.) BSP) stands in which severe soil disturbance by wildfire restores forest productivity. The objective of this study was to determine, 8 years after harvest, how soil disturbance created by clearcutting and careful logging affected black spruce natural regeneration and growth and how this effect varied by soil type. While regeneration density was higher following careful logging, stocking was not influenced by harvest method. Regenerating stands were taller following clearcutting despite potentially greater damages to preestablished regeneration. Compared with careful logging, clearcutting also resulted in reduced cover of Sphagnum spp. and ericaceous shrubs. Spruce stem density and stocking were both higher on organic and subhydric soils and lower on mesic soils. No significant interactions were observed between harvest method and soil type, indicating that the observation of taller black spruce stands and adequate stocking with clearcutting may be applicable to all soil types considered in this study. These results suggest that an adequate level of soil disturbance is an important part of forest regeneration, particularly in ecosystems where an autogenic reduction in productivity occurs.