bluuebunny/crossref_metadata_2025 huggingface dataset:
Conceptualizing and Testing a Social Cognitive Model of the Digital Divide
Authors: Wei Kwok-Kee , Teo Hock-Hai , Chan Hock Chuan , Tan Bernard C. Y.
Published: March 2010

The digital divide has loomed as a public policy issue for over a decade. Yet, a theoretical account for the effects of the digital divide is currently lacking. This study examines three levels of the digital divide. The digital access divide (the first-level digital divide) is the inequality of access to information technology (IT) in homes and schools. The digital capability divide (the second-level digital divide) is the inequality of the capability to exploit IT arising from the first-level digital divide and other contextual factors. The digital outcome divide (the third-level digital divide) is the inequality of outcomes (e.g., learning and productivity) of exploiting IT arising from the second-level digital divide and other contextual factors. Drawing on social cognitive theory and computer self-efficacy literature, we developed a model to show how the digital access divide affects the digital capability divide and the digital outcome divide among students. The digital access divide focuses on computer ownership and usage in homes and schools. The digital capability divide and the digital outcome divide focus on computer self-efficacy and learning outcomes, respectively. This model was tested using data collected from over 4,000 students in Singapore. The results generate insights into the relationships among the three levels of the digital divide and provide a theoretical account for the effects of the digital divide. While school computing environments help to increase computer self-efficacy for all students, these factors do not eliminate knowledge the gap between students with and without home computers. Implications for theory and practice are discussed.
Alliances, Rivalry, and Firm Performance in Enterprise Systems Software Markets: A Social Network Approach
Authors: Chellappa Ramnath K. , Saraf Nilesh
Published: March 2010

Enterprise systems software (ESS) is a multibillion dollar industry that produces systems components to support a variety of business functions for a widerange of vertical industry segments. Even if it forms the core of an organization's information systems (IS) infrastructure, there is little prior IS research on the competitive dynamics in this industry. Whereas economic modeling has generally provided the methodological framework for studying standards-driven industries, our research employs social network methods to empirically examine ESS firm competition. Although component compatibility is critical to organizational end users, there is an absence of industry-wide ESS standards and compatibility is ensured through interfirm alliances. First, our research observes that this alliance network does not conform to the equilibrium structures predicted by economics of network evolution supporting the view that it is difficult to identify dominant standards and leaders in this industry. This state of flux combined with the multifirm multicomponent nature of the industry limits the direct applicability of extant analytical models. Instead, we propose that the relative structural position acquired by a firm in its alliance network is a reasonable proxy for its standards dominance and is an indicator of its performance. In lieu of structural measures developed mainly for interpersonal networks, we develop a measure of relative firm prominence specifically for the business software network where benefits of alliances may accrue through indirect connections even if attenuated. Panel data analyses of ESS firms that account for over 95% of the industry revenues, show that our measure provides a superior model fit to extant social network measures. Two interesting counterintuitive findings emerge from our research. First, unlike other software industries compatibility considerations can trump rivalry concerns. We employ quadratic assignment procedure to show that firms freely form alliances even with their rivals. Second, we find that smaller firms enjoy a greater value from acquiring a higher structural position as compared to larger firms.
Pricing Digital Goods: Discontinuous Costs and Shared Infrastructure
Authors: Huang Ke-Wei , Sundararajan Arun
Published: March 2010

In this paper, we analyze a model of usage pricing for digital products with discontinuous supply functions. This model characterizes a number of information technology-based products and services for which variable increases in demand are fulfilled by the addition of blocks of computing or network infrastructure. Such goods are often modeled as information goods with zero variable costs; in fact, the actual cost structure resembles a mixture of zero marginal costs and positive periodic fixed costs. This paper discusses the properties of a general solution for the optimal nonlinear pricing of such digital goods. We show that the discontinuous cost structure can be accrued as a virtual constant variable cost. This paper applies the general solution to solve two related extensions by first investigating the optimal technology capacity planning when the cost function is both discontinuous and declining over time, and then characterizing the optimal costing for the discontinuous supply when it is shared by several business profit centers. Our findings suggest that the widely adopted full cost recovery policies are typically suboptimal.
The Combined Inelastic Neutron Scattering (INS) and Solid-State DFT Study of Hydrogen-Atoms Dynamics in Kaolinite-dimethylsulfoxide Intercalate
Authors: Smrčok L’ubomír , Tunega Daniel , Ramirez-Cuesta Anibal Javier , Ivanov Alexander , Valúchová Jana
Published: March 2010

Vibrational spectra of two kaolinite-dimethylsulfoxide intercalates, obtained using inelastic neutron scattering (INS), were analyzed with a view to understanding the dynamics of the hydrogen atoms in the structure. The main focus was on the spectral region 0–1700 cm−1, which is difficult to analyze using optical spectroscopy. The experimental vibrational spectra of kaolinite:dimethylsulfoxide and kaolinite:d6-dimethylsulfoxide collected using two different spectrometers were interpreted by means of the solid-state DFT calculations. Calculated spectra were obtained by both normal-mode analysis and molecular dynamics going beyond the harmonic approximation. The Al-O-H bending modes were found to be spread over the large interval 100−1200 cm−1, with the dominant contributions located between 800 and 1200 cm−1. The shape of the individual hydrogen spectrum depends on whether or not the respective hydrogen atom is involved in an O-H⋯O hydrogen bond and on its strength. The modes corresponding to the in-plane movements of the inner-surface hydrogen atoms are well defined and always appear at the top of the intervals of energy transfer. In contrast, the modes generated by the out-of-plane movements of the hydrogen atoms are spread over large energy intervals extending down to the region of external (lattice) modes. The C-H modes are concentrated mainly in the three regions 1200–1450 cm−1, 800–1100 cm−1, and 0–400 cm−1. While the first two regions are typical of the various deformational modes of methyl groups, the low-energy region is populated by the modes corresponding to the movements of the whole dimethylsulfoxide molecule.
Structure and Properties of Hydrogenated Nitrile Rubber/Organo-Montmorillonite Nanocomposites
Authors: Gu Zheng , Song Guojun , Liu Weisheng , Yang Shujing , Gao Jianming
Published: March 2010

The aim of the work was to study the effect of organo-montmorillonite (OMt) on the properties of hydrogenated nitrile rubber (HNBR)/OMt nanocomposites. The nanocomposites were prepared by a melt intercalation method. The structure of the composites was studied by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The behavior of stress-strain, aging resistance, solvent resistance, and the dynamic mechanical properties of HNBR/OMt nanocomposites were investigated. The TEM and XRD results showed that the OMt layers were dispersed homogeneously in the HNBR matrix. The HNBR/OMt nanocomposites showed excellent mechanical properties which were attributed to the nanometer scale dispersion and strong interaction between the HNBR and OMt. The composites possessed excellent aging resistance and oil resistance, which improved with OMt content. Dynamic mechanical analysis showed that the glass-transition temperature, Tg, of the HNBR/OMt nanocomposites was increased and the nanocomposites had a good rolling resistance in comparison to pure HNBR. The composites displayed better dynamic mechanical properties.
Approach to a Descriptive Model of Charge Reduction in Vermiculite by Hydrothermal Treatment
Authors: Campos Ana M. , Moreno Sonia , Molina Rafael
Published: March 2010

Vermiculites have the potential to serve as effective catalysts if pillared with Al, but their high charge presents an obstacle to the pillaring process. The purpose of this study was to submit natural vermiculite to thermal treatments in the presence of water vapor in order to effect a reduction in the global negative charge and thereby to enhance its susceptibility to pillaring. The process of charge reduction in vermiculite under the conditions selected involved the extraction of 25% of IVAl accompanied by the extraction of structural Mg and charge-compensating cations (Ca2+, Na+, and K+). The results indicate a reduction of 35% in the global negative charge in vermiculite by the end of the treatment. Some of the VIAl content was not removed during acid washing, and probably remained in the solid in structural positions in the octahedral sheet.
From That's Entertainment! to That's Entertainment? globalization and the consumption of the Hollywood musical in Germany and Austria
Authors: Jubin Olaf
Published: March 2010

The media world today is dominated by multinational media operations, most of them with headquarters in the United States of America. How does the fact that most decisions regarding the advertising and preparation of products for the international market are made in the United States
and not in the respective target countries influence the overseas reception of the film musical one of the most American of movie genres? The essay approaches this question by looking at the way Hollywood musicals have been and still are offered for consumption in the German-speaking film
market, which originally had almost no acquaintance with the aesthetics and stars of the dream factory's All Talking! All Singing! All Dancing! movies. Through examples taken from several decades of dubbing, subtitling and cutting film musicals, the article analyses how the attempts of US
film distributors to raise their profile and increase their market share have drastically changed the meaning of certain film musicals and affected the reception by both the general public and film experts of the genre and some of its stars, such as Judy Garland and Doris Day. Despite the
opportunity to present original as well as uncut or extended versions the advent of the DVD has done nothing to change German and Austrian (mis)conceptions of the Hollywood musical as US film companies still tend to treat foreign audiences as a mere extension of the home market.
Nine Key Functions for a Human Subjects Protection Program for Community-Engaged Research: Points to Consider
Authors: Ross Lainie Friedman , Loup Allan , Nelson Robert M. , Botkin Jeffrey R. , Kost Rhonda , Smith George R. , Gehlert Sarah
Published: March 2010

The ethical conduct of community-engaged research (CEnR), of which the Community-Based Participatory Research (CBPR) model is the partnership model most widely discussed in the CEnR literature and is the primary model we draw upon in this discussion, requires an integrated and comprehensive human subjects protection (HSP) program that addresses the additional concerns salient to CEnR where members of a community are both research partners and participants. As delineated in the federal regulations, the backbone of a HSP program is the fulfillment of nine functions: (1) minimize risks; (2) reasonable benefit-risk ratio; (3) fair subject selection; (4) adequate monitoring; (5) informed consent; (6) privacy and confidentiality; (7) conflicts of interest; (8) address vulnerabilities; and (9) HSP training. The federal regulations, however, do not consider the risks and harms that may occur to groups, and these risks have not traditionally been included in the benefit: Risk analysis nor have they been incorporated into an HSP framework. We explore additional HSP issues raised by CEnR within these nine ethical functions. Various entities exist that can provide HSP—the investigator, the Institutional Review Board, the Conflict of Interest Committee, the Research Ethics Consultation program, the Research Subject Advocacy program, the Data and Safety Monitoring Plan, and the Community Advisory Board. Protection is best achieved if these entities are coordinated to ensure that no gaps exist, to minimize unnecessary redundancy, and to provide checks and balances between the different entities of HSP and the nine functions that they must realize. The document is structured to provide a “points-to-consider” roadmap for HSP entities to help them adequately address the nine key functions necessary to provide adequate protection of individuals and communities in CEnR.
Effect of Channel Catfish Stocking Rate on Yield and Water Quality in an Intensive, Mixed Suspended-Growth Production System
Authors: Green Bartholomew W
Published: March 2010

This study was conducted to determine the effect of stocking rate on yield of channel catfish Ictalurus punctatus and water quality in a mixed suspended-growth (biofloc) production system with zero water exchange. Channel catfish (National Warmwater Aquaculture Center 103 strain; average fish weight = 13 g) were stocked into nine 35-m2 tanks (28 m3/tank) at a rate of 2.9, 5.7, or 8.5 fish/m2 for a 238-d grow-out period. One 1.865-kW blower for every three tanks supplied air continuously through a diffuser grid (constructed of 2.5-cm-diameter polyvinyl chloride pipe) on the bottom of each tank. Well water was added only periodically to replace evaporative losses. Fish in each tank were fed daily as much floating catfish feed (32% protein, extruded pellets) as they could consume in a 20-min period. Channel catfish net yield ranged from 0.99 to 3.71 kg/m3 and increased linearly with stocking rate (r  2 = 0.87). At harvest, mean individual weight (0.54 kg/fish), survival (62.1%), specific growth rate (1.54% per day), and net feed conversion ratio (1.9) did not differ significantly among stocking rates. Cumulative feed addition averaged 6.66 kg/m3 for the 8.5-fish/m2 treatment, significantly greater than the 4.04 and 2.96 kg/m3 for the 5.7- and 2.9-fish/m2 treatments, respectively, which did not differ. Mean nitrate-nitrogen concentration was significantly higher and mean pH was significantly lower in the 8.5-fish/m2 treatment compared with the other two treatments. There were no other differences in water quality among treatments. Total ammonia-nitrogen concentration was low throughout the experiment because of nitrification and phytoplankton uptake. This study demonstrated that high yields of channel catfish could be obtained by stocking up to 8.5 fish/m2 in a mixed suspended-growth production system.
Plasma Cortisol, Blood Glucose, and Marketability of Koi Transported with Metomidate Hydrochloride
Authors: Crosby Tina C , Petty B Denise , Hamlin Heather J , Guillette Louis J , Hill Jeffrey E , Hartman Kathleen H , Yanong Roy P E
Published: March 2010

The transportation of fish is stressful and may negatively affect their health, appearance, and marketability (i.e., their appearance, behavior, and activity level). The objective of this study was to determine whether sedation with metomidate hydrochloride during transportation would inhibit elevation of the plasma cortisol and blood glucose levels of koi, a strain of common carp Cyprinus carpio, and improve their marketability relative to that of transported control fish. The metomidate concentrations tested were 0 (control), 1.0, 2.0, 3.0, and 4.0 mg/L. The fish were transported for approximately 24 h via truck and domestic airline under typical shipping conditions. Blood was sampled at 0, 2, 6, and 12 h posttransportation, and appearance and behavior were observed at 0, 1, 4, 8, and 12 h and 7 d posttransportation. Immediately after transport, the plasma cortisol levels of koi in metomidate concentrations of 3.0 and 4.0 mg/L were significantly lower than those of the controls, but no differences were observed in blood glucose levels among the various metomidate treatments. Also, there were no differences in the appearance and behavior scores among transported fish, but the scores of koi transported in 0 and 4.0 mg/L were significantly lower than those of nontransported koi at 0 h posttransportation. In this experiment, a metomidate concentration of 3.0 mg/L had a transient inhibitory effect on plasma cortisol and did not have an adverse effect on appearance or behavior; it therefore represented the best concentration for the transportation of koi among those tested. However, more research is required to fully understand the effects of metomidate exposure on koi.
Culture of Pinfish at Different Stocking Densities and Salinities in Recirculating Aquaculture Systems
Authors: Ohs Cortney L , Grabe Scott W , DeSantis Shawn M , DiMaggio Matthew A , Rhyne Andrew L
Published: March 2010

There is great demand for marine baitfish in U.S. coastal states. The supply of marine baitfish in the United States is almost completely wild caught, and this fishery is seasonal and inconsistent. Aquaculture may be able to consistently supply marine baitfish for anglers. Two experiments were conducted to evaluate the effects of stocking density and salinity on the growth and survival of pinfish Lagodon rhomboides cultured in recirculating aquaculture systems. For the stocking density experiment, juvenile pinfish were stocked (50, 200, 400, and 600 fish/m3) into 1,600-L circular tanks in three identical recirculating systems with a salinity of 27 g/L and were cultured for 82 d. Mean survival was not statistically different among densities and ranged from 94.3% to 99.18%. Daily growth of pinfish ranged from 0.35 to 0.39 g·fish−1·d−1. Mean percent weight gain ranged from 624% to 690% and followed a density-dependent trend. Final total length followed a density-dependent pattern, with each increasing density exhibiting statistically significant decreases in length. Mean feed conversion ratio (FCR) ranged from 1.70 to 1.89. In the salinity experiment, juvenile pinfish were stocked at a density of 120 fish/m3 into 1,600-L tanks within four identical recirculating systems and were cultured for 65 d. Treatment salinities were 9 or 27 g/L; each salinity level was maintained in two systems. Two size-classes were stocked separately into two tanks within all four systems, resulting in four replicates per treatment. Mean survival was not significantly different among treatments and ranged from 98.2% to 99.9%. Mean percent weight gain ranged from 234% to 284%, with no significant differences between salinities. Mean FCR ranged from 2.5 to 3.1 and did not significantly differ between salinities, although fish in the small size-class converted feed more efficiently than those in the large size-class. Pinfish show great potential as a new aquaculture species and can be successfully cultured in recirculating systems at stocking densities of 600 fish/m3 and at a salinity as low as 9g/L.
Origin of Chironomid Larvae in Plastic-Lined Culture Ponds: Airborne or Water Supply?
Authors: Kaatz Sarah E , Morris Joseph E , Rudacille James B , Clayton Richard D
Published: March 2010

Twelve 0.26-m3, shallow, plastic pools at an Iowa fish culture facility were used as mesocosms to determine the mode (airborne versus water supply) and rate of colonization by benthic chironomid larvae without the predation pressure of fingerling walleyes Sander vitreus. Chironomid larvae have particular importance in the culture of walleye fingerlings. Concurrent with walleye hatchery operations in nearby plastic-lined production ponds, pools were filled and then fertilized using the same protocols as the production ponds. A 2 × 2 factorial experimental design was used that included screened (1,000-μm mesh over the top of the pools) and nonscreened pools and filtered (75-μm-mesh sock) and nonfiltered water in the pools. Chironomid larvae were sampled twice during the 5-week culture season with Hester–Dendy samplers. At the end of the walleye culture season, there were no significant differences in chironomid density between filtered (108 larvae/m2) and nonfiltered (657 larvae/m2) pools, but nonscreened pools (592 larvae/m2) had larger densities of chironomid larvae than screened pools (174 larvae/m2). These results suggest that airborne movement and egg deposition by chironomid adults, rather than transfer of organisms from the water supply reservoir to the culture facility, constitute the primary method of chironomid colonization in plastic-lined ponds.
Osmoregulatory Evaluation of the Seminole Killifish after Gradual Seawater Acclimation
Authors: DiMaggio M A , Ohs C L , Grabe S W , Petty B D , Rhyne A L
Published: March 2010

Aquaculture of marine baitfish species is still in its relative infancy and the increasing value of coastal property is forcing marine aquaculture inland. The Seminole killifish Fundulus seminolis, a freshwater species that is endemic to Florida, has recently emerged as a candidate for marine baitfish aquaculture. Gradual acclimation of Seminole killifish from 0-g/L salinity to natural seawater at 32-g/L salinity was carried out over 24, 48, 72, and 96 h. Physiological analyses of seawater-acclimated fish yielded elevated plasma ion (sodium, potassium, chloride) and osmolality concentrations accompanied by decreases in body weight and muscle water content. Although all of the seawater-acclimated physiological endpoints measured remained significantly different from control values, a general trend signaling the initiation of osmoregulatory compensation was noticed in 96-h values as select analytes began to migrate towards reference values derived from controls. Results of this investigation will contribute to the development of salinity acclimation protocols for use in commercial aquaculture as well as marketing and distribution strategies for the economically valuable Seminole killifish.
Surface Disinfection and Removal of Adhesiveness from Rainbow Smelt Eggs
Authors: Walker Abigail B , Ward Daniel , Duclos Kristin , Peters Michael , Berlinsky David L
Published: March 2010

The survival of rainbow smelt Osmerus mordax embryos was evaluated after treating fertilized eggs with tannic acid (150, 300, 600, or 1,200 mg/L) in suspension for 10 min to remove adhesiveness or treating them with calcium hypochlorite (25, 50, 75, or 100 mg/L), polyvinylpyrrolidone iodine (PVP-I; 25, 50, 75, or 100 mg/L), or hydrogen peroxide (H2O2; 500, 1,000, 1,500, or 2,000 μL/L) for 15 min to achieve surface disinfection. Nonlethal concentrations of egg disinfectants were also evaluated for their germicidal effects by culturing disinfected eggs in sterile Bacto Tryptic Soy Broth. The hatching success of the eggs treated with tannic acid (at all concentrations) was not different from that of the controls. Disinfecting eggs with H2O2 (all doses) and low doses of calcium hypochlorite (25–75 mg/L) or PVP-I (25 mg/L) did not reduce embryo survival, but exposure to calcium hypochlorite and PVP-I at higher concentrations (100 mg/L and 50, 75, or 100 mg/L, respectively) was lethal. In the first disinfection trial both H2O2 and PVP-I (25 mg/L) prevented bacterial growth, but only H2O2 at 2,000 μL/L did so in the second trial.
Mitochondrial DNA Dosage Effects in Triploid Grass Carp
Authors: Anderson Joel D
Published: March 2010

The grass carp Ctenopharyngodon idella is used widely in aquaculture for aquatic weed control. Historically, concern about the proliferative growth of nonnative diploid grass carp populations led to development of the hydrostatic pressure shock technique for the production of sterile triploids. Despite the success of this technique in accomplishing management goals, little is known about the cellular physiology of triploids. In particular, few studies have explored whether the induction of triploidy via hydrostatic pressure shock affects mitochondrial DNA (mtDNA) copy number in addition to that of chromosomal DNA. While the nuclear DNA (nDNA): mtDNA ratio is conserved in polyploid yeast, there are few data suggesting that vertebrate polyploids have nDNA: mtDNA ratios consistent with those of their diploid counterparts. In this study, two novel quantitative polymerase chain reaction assays were used to explore gene copy number in the nuclear and mitochondrial genome of diploid and triploid grass carp and to determine whether nuclear–mitochondrial copy number differences can be exploited to determine the ploidy of individual fish. The results of this study suggest that the ratio of mtDNA to overall cellular DNA is conserved in vertebrate polyploids and that real-time assays of mtDNA copy number are not a feasible alternative to current methodologies for identifying triploid grass carp.
Fisher-Collected Sampling Data: Lessons from the New Zealand Experience
Authors: Starr Paul
Published: March 2010

The New Zealand fishing industry has adopted a strategy of using fishers to collect biological sampling data from their fisheries, usually on a voluntary basis. This approach can be adopted for data-poor fisheries to obtain data that would otherwise not be available. This article describes a wide range of such programs implemented in fisheries spanning a period of 15 years. This article also reveals the designs employed, how these data have been used in stock assessment and fisheries management situations, and some of the problems encountered in administering these programs. I conclude that while these programs need supervision and support in order to succeed, the benefits that can accrue are considerable. These benefits include a dynamic sampling design that should ensure good representation of the fishery and the involvement of fishers in collecting the data used to manage their fishery.
Developing British Columbia's Inshore Rockfish Conservation Strategy
Authors: Yamanaka K. Lynne , Logan Gary
Published: March 2010

The hook-and-line fishery for inshore rockfishes Sebastes spp. in British Columbia is diverse, with participants in directed commercial, recreational, and Aboriginal fisheries, as well as other incidental fisheries coastwide. Rockfish species targeted in this fishery are yelloweye rockfish S. ruberrimus and quillback rockfish S. maliger. Expansion of the fishery outpaced management's effort controls, and catch quotas were implemented in the early 1990s. Conservation concerns largely based on life history traits resulted in restrictions to the directed fishery, but other fisheries remained unmanaged. A growing mismatch between the demands of fishery management and the difficulties of inshore rockfish stock assessment led to the development of a conservation strategy in 2001. The strategy included the following four components: comprehensive catch monitoring; dramatically reduced fishing mortality; extensive fishery closed areas; and improved stock assessment and monitoring. Targets were met in 2002 by reducing the fishing mortality rate by 75% in the protected waters east of Vancouver Island (inside area) and by 50% in the remaining open-coast waters (outside area). Research survey programs were reinstated by the provision of funds in 2003. An intricate catch accounting and monitoring proposal from industry set the rules in a pilot groundfish licensing integration program launched in 2006. Progress continues to be made on this difficult task. Areas closed to all fishing were implemented in 30% of the rockfish habitats throughout the inside area and in 20% of the outside area in 2007. Key to the development of the strategy was the consultation process. Consensus-based decision making within the Department of Fisheries and Oceans and the organization and commitment of industry participants contributed to this success. Open communication and respectful conduct brought participants to the table and kept them engaged. Without the consultation process and the benefits from this exchange, the conservation strategy would not have been possible.
Essential Habitat Identification for Age-0 Rockfish along the Central Oregon Coast
Authors: Gallagher M. Brett , Heppell Selina S.
Published: March 2010

The habitat needs of nearshore juvenile rockfish Sebastes spp. have rarely been studied but are an essential component of habitat identification for management. We investigated the relationships between habitat type, species composition, and growth of juvenile rockfish after settlement into nearshore reefs and estuaries in central Oregon. We identify and prioritize essential fish habitat (EFH) for blue rockfish S. mystinus and black rockfish S. melanops caught by minnow traps and by scuba divers with hand nets. Species were confirmed through genetic analysis. Our nearshore samples were dominated by blue rockfish, while estuary samples contained almost exclusively black rockfish. Settlement patterns suggest that black rockfish had a strong preference for anthropogenic habitat (docks, pilings, jetties) within the Yaquina Bay estuary. Growth was not significantly different among habitats or sampling years for either black rockfish or blue rockfish. We identify estuaries as EFH for black rockfish juveniles along the central Oregon coast and confirm nearshore reef areas as EFH for blue rockfish juveniles. Small sample sizes of juvenile yellowtail rockfish S. flavidus and widow rockfish S. entomelas suggest that estuaries are also important for these species.
8Cl-cAMP modifies the balance between PKAR1 and PKAR2 and modulates the cell cycle, growth and apoptosis in human adrenocortical H295R cells
Authors: Bouizar Zhor , Ragazzon Bruno , Viou Lucie , Hortane Mariuccia , Bertherat Jerôme , Rizk-Rabin Marthe
Published: March 2010

Various types of protein kinase A (PKA) alterations have been observed in adrenocortical tumours and Carney complex (CNC). PKA is a heterotetramer of two regulatory and two catalytic subunits. The R1A and R2B proteins are the most abundant regulatory subunits in endocrine tissues. A decrease in R2B protein levels has been observed in adrenal adenoma, whereas tumours from patients with CNC display a decrease in R1A protein levels. Dysregulation of the balance between R1A and R2B may thus be involved in adrenal tumourigenesis. We investigated the impact of the differences in the balance of PKA subunits on cell growth using specific cAMP analogues. We assessed the effects of 8-chloroadenosine-cAMP (8Cl-cAMP), a site-selective activator of PKA R2B, in H295R adrenocortical cells. 8Cl-cAMP stimulated PKA activity, decreased R1A levels and increased R2B levels. It had no cytotoxic effects, initially stimulating DNA synthesis and then inducing apoptosis by disrupting G2/M progression. We observed an initial accumulation of cells in the S phase, translocation of cyclin A to the nucleus, CDK2 activation, sustained DNA synthesis and proliferating cell nuclear antigen accumulation. Cell cycle arrest in the G2 phase was parallel with the accumulation of cyclin B and the inactivation of CDC2 kinase. The 8CPT-cAMP, which activates the R2B subunit, had similar effects. R2B silencing reduced the apoptosis induced by tumour necrosis factor α and transforming growth factor β. Thus, R2B is a key regulator of proliferation/differentiation in H295R cell line along with the complex balance between the PKA subunits. Activation of PKA R2B and dysregulation of the R1A/R2B balance regulate cell cycle progression and apoptosis in adrenocortical cells by modulating cyclin production and cyclin-dependent kinase activities.
Unfired clay masonry bricks incorporating slate waste
Authors: Oti J. E. , Kinuthia J. M. , Bai J.
Published: March 2010

This paper discusses the potential of using slate waste generated from roofing slate production in the UK in the manufacture of unfired clay masonry bricks. Ground granulated blast-furnace slag activated by lime and Portland cement were used to stabilise Lower Oxford Clay incorporating slate waste in the preparation of laboratory cylindrical test specimens. The specimens were moist cured at room temperature (20±2°C) for between 3 and 90 days before testing for compressive strength. The drying and linear expansion behaviours of the test samples were assessed by means of moisture content measurement (at the age of testing) and linear expansion measurement after soaking the samples in deionised water. The strength of the cement-activated blended mixture was lower than that of the lime-activated mixtures. An environmental comparison of the unfired clay masonry bricks with mainstream construction (fired) bricks shows that the unfired clay bricks have good environmental characteristics over a range of important criteria. These results suggest that there is potential for using activated slag mixtures in the manufacture of bricks for low-cost environmentally friendly housing and energy-efficient masonry wall construction within the UK.
Crushed brick blends with crushed rock for pavement systems
Authors: Aatheesan T. , Arulrajah A. , Bo M. W. , Vuong B. , Wilson J.
Published: March 2010

Construction and demolition materials account for a major proportion of the waste materials present in landfills in Australia. Crushed brick and crushed rock are, however, viable substitute materials for natural resources used as construction materials in engineering applications. Crushed brick is one of the major components of demolition materials. The crushed rock used in this study originates from ‘basalt floaters’ or surface excavation rock (basalt), which commonly occurs near the surface to the north and west of Melbourne, Australia. The engineering characteristics of various proportions of crushed brick blends with crushed rock obtained from extensive laboratory testing are presented in this paper. The engineering properties obtained were compared with existing local road authority specifications for pavement sub-base or light-duty base material and backfill material for drainage systems to ascertain the potential use of crushed brick blends. The materials for the experimental works were collected from a recycling facility in Victoria, Australia.
Applications of slate waste material in the UK
Authors: Oti J. E. , Kinuthia J. M. , Snelson D. G. , Bai J.
Published: March 2010

The potential of using slate waste generated from roofing slate production in the UK in various applications is reviewed and the environmental impact of the stockpile of slate waste is also assessed. The findings suggest that there is potential for using slate waste in many situations, including engineering applications. In order to reduce the environmental impact arising from the quarrying of conventional construction materials, the abundance of slate waste in Wales in particular and the UK in general could be exploited. With associated economic advantages despite reported transportation difficulties, utilisation of this waste stream for most practical and low- to medium-strength engineering applications is feasible and would maximise the use of surplus regional and national industrial wastes and minimise the environmental impact of their disposal.
Viability Tests, Active Caspase‐3 and −7, and Chromatin Structure in Ram Sperm Selected Using the Swim‐Up Procedure
Authors: Pichardo Ana I. , Aragón‐Martínez Andrés , Ayala‐Escobar María E. , Domínguez‐Vara Ignacio A.
Published: March 2010

ABSTRACT: Swim‐up (SU) is a technique that permits the obtaining of motile sperm. Based on the sperm motility of neat ejaculates, we analyzed functional parameters, cytoplasmic esterases, and mitochondrial dehydrogenases of ram sperm using calcein acetomethylester and resazurin, respectively. Active caspase‐3 and −7 and chromatin structure were evaluated in ram sperm before and after the SU process. There were no changes in any of the viability parameters after SU in neat semen samples with less or more than 25% motility. The percentage of active caspase‐3 and −7 decreased after SU (68.8 ± 4.6 vs 54.2 ± 6.0), whereas a small but significant increase of chromatin structural abnormalities was observed (DNA fragmentation index[DFI], 287.3 ± 3.1 vs 297.2 ± 2.4). For the first time, the location of active caspase‐3 and −7 was described for ram sperm. Notably, we found active caspases in the implantation fossa region. The presence of active caspases in neat ejaculates and the diminished presence of active caspases in SU‐processed ejaculates suggest a role for caspases in motility and possibly in male fertility. The results of this study indicatethat the evaluation of more than one cell‐function marker is necessary to appropriately evaluate sperm quality. Furthermore, in semen samples with low motility, a lower percentage of sperm with active caspases is obtained after SU, although these sperm present increased values of DFI.
Phenotypic Expression of Partial AZFc Deletions Is Independent of the Variations in DAZL and BOULE in a Han Population
Authors: Chen Pu , Ma Mingyi , Li Lei , Zhang Sizhong , Su Dan , Ma Yongxin , Liu Yunqiang , Tao Dachang , Lin Li , Yang Yuan
Published: March 2010

ABSTRACT: DAZ on the Y chromosome and 2 autosomal ancestral genes DAZL and BOULE are suggested to represent functional conservation in spermatogenesis. The partial AZFc deletion, a common mutation of the Y chromosome, always involves 2 DAZ copies and represents a different spermatogenic phenotype in the populations studied. To investigate whether the variations in DAZL and BOULE influence partial AZFc deletion phenotype, the genotyping of 15 loci variations, including 4 known mutations and 11 single‐nucleotide polymorphisms (SNPs), was carried out in 157 azoo‐/oligzoospermic men and 57 normozoospermic men, both groups with partial AZFc deletions. The frequencies of the alleles, genotypes, and haplotypes of the variations were compared between the 2 groups. As a result, for 9 exonic variations in DAZL and BOULE, only T12A was observed in both groups with similar frequency, and I71V was identified in an azoospermic man with b2/b3 deletion, whereas the rest were absent in the population. The distribution of DAZL haplotypes from 4 variations, including T12A, and of BOULE haplotypes from 2 SNPs was similar between men with normozoospermia and spermatogenic failure. Our findings indicate that the contribution of DAZL and BOULE variations to spermatogenic impairment in men with the DAZ defect is greatly limited, suggesting that expression of spermatogenic phenotypes of partial AZFc deletions is independent of the variations in DAZL and BOULE in the Han population.
A Novel Treatment Modality in Patients With Premature Ejaculation Resistant to Conventional Methods: The Neuromodulation of Dorsal Penile Nerves by Pulsed Radiofrequency
Authors: Basal Seref , Goktas Serdar , Ergin Atilla , Yildirim Ibrahim , Atim Abdulkadir , Tahmaz Lutfi , Dayanc Murat
Published: March 2010

ABSTRACT: Premature ejaculation (PE) is the most common sexual problem experienced by men, and it affects 20%–30% of them. Pulsed radiofrequency (PRF) neuromodulation has been shown to be an effective treatment for a wide range of pain conditions. We used PRF to treat PE by desensitizing dorsal penile nerves in patients resistant to conventional treatments. Fifteen patients with a lifelong history of PE, defined as an intravaginal ejaculatory latency time (IELT) of <1 minute that occurred in more than 90% of acts of intercourse and was resistant to conventional treatments, were enrolled in this study. Patients with erectile dysfunction were excluded. The mean age of the patients was 39 ± 9 years. Before and 3 weeks after the treatment, IELT and sexual satisfaction score (SSS; for patients and their partners) were obtained. The mean IELTs before and 3 weeks after procedure were 18.5 ± 17.9 and 139.9 ± 55.1 seconds, respectively. Side effects did not occur. Mean SSSs of patients before and after treatment were 1.3 ± 0.3 and 4.6 ± 0.5, and mean SSSs of partners before and after treatment were 1.3 ± 0.4 and 4.4 ± 0.5, respectively. In all cases, IELT and SSS were significantly increased (P < .05). None of the patients or their wives reported any treatment failure during the follow‐up period. The mean follow‐up time was 8.3 ± 1.9 months. It is early to conclude that this new treatment modality might be used widely for the treatment of PE; however, because it is an innovative modality, placebo‐controlled studies (eg, sham procedure), with larger numbers of patients and including assessment of penile sensitivity (eg, biothesiometry), are needed.
Assessment of Seminal Estradiol and Testosterone Levels as Predictors of Human Spermatogenesis
Authors: Zhang Qiufang , Bai Quan , Yuan Yang , Liu Ping , Qiao Jie
Published: March 2010

ABSTRACT: The proposed hypothesis for this study was that seminal testosterone/estradiol levels and/or their ratios may be a good indicator for predicting normal spermatogenesis. The concentrations of estradiol and testosterone in seminal fluid were measured using competitive immunoassay techniques in specimens collected from 192 infertile patients and 103 normospermic men. Infertile patients were subdivided into three groups according to their semen analysis results and testicular biopsy: oligozoospermia, obstructive azoospermia (OA), and nonobstructive azoospermia (NOA). Results showed that seminal testosterone levels in the infertile groups were lower than in the normospermic individuals (P < .01), whereas seminal estradiol levels in the OA group were significantly higher than those in normospermic and NOA groups (P < .01). Testosterone/estradiol ratios in the seminal plasma from the infertile groups were significantly lower than that in the normospermic group (P < .01). However, seminal estradiol levels among normospermic and NOA groups showed no significant differences. These results suggest that the local balance between androgen and estrogen, or their ratios, may play an important role in maintaining normal spermatogenesis. Also, decreased seminal testosterone/estradiol ratio may be a good indicator for identifying the absence of sperm production in NOA patients.
Semen Quality of Male Idiopathic Infertile Smokers and Nonsmokers: An Ultrastructural Study
Authors: Collodel G. , Capitani S. , Pammolli A. , Giannerini V. , Geminiani M. , Moretti E.
Published: March 2010

ABSTRACT: This retrospective study was aimed at evaluating the effects of cigarette consumption on semen parameters in a group of men with idiopathic infertility. The semen quality of 2 groups of men with idiopathic infertility, smokers (n = 118) and nonsmokers (n = 153), were compared. Conventional semen analysis was performed and sperm morphology was assessed by transmission electron microscopy (TEM). TEM data were elaborated by means of a mathematical formula based on a Bayesian technique able to furnish a fertility index (FI), and the percentages of sperm apoptosis, necrosis, and immaturity. Values of normality recommended by World Health Organization guidelines were used as a control for conventional semen analysis, and values from sperm of 25 men of proven fertility were used for TEM indices. Infertile smoker and nonsmoker patients showed similar sperm parameters, although sperm motility and TEM analysis values in both groups were significantly impaired compared with controls. Smoker patients were then classified as mild (≥1 and ≤10 cigarettes/d), moderate (>10 and <20 cigarettes/day), or heavy smokers (≥20 cigarettes/d). Sperm concentration and FI were significantly (P < .05) different among the 3 considered smoker classes. Comparing the pairs of smoker classes, sperm concentration and FI in heavy smokers were significantly lower (P < .05) than that observed in mild smoker and nonsmoker groups. Although semen quality in males with idiopathic infertility seems not to be dramatically affected by cigarette consumption, heavy smokers show significantly lower sperm concentration and FI: another strong reason to stop smoking.
Raised Inflammatory Markers in Semen From Men With Asymptomatic Chlamydial Infection
Authors: Kokab Abas , Akhondi Mohammad M. , Sadeghi Mohammad R. , Modarresi Mohammed H. , Aarabi Mohsen , Jennings Roy , Pacey Allan A. , Eley A.
Published: March 2010

ABSTRACT: The aim of this study was to determine whether interleukin (IL)‐6 and IL‐8 concentrations, as well as numbers of seminal leukocytes in a population of infertile men, some of whom were Chlamydia trachomatis positive, were related to chlamydial infection. Our patient group included 255 men attending for diagnostic semen analysis as part of infertility investigations. Significantly raised levels of IL‐8, but not IL‐6, were found in C trachomatis–infected patients but not in uninfected patients. Raised IL‐8 levels in semen were also associated with an increase in semen volume. There was a relationship between C trachomatis infection and lower progressive motile sperm, as well as an increase in seminal leukocytes. The overall prevalence rate for C trachomatis was 6.2%, and more infections were detected in semen than in first void urine. This study supports the suggestion that IL‐8 might be used as a marker for male genital tract infection, especially when due to C trachomatis. In this study, there was a relationship between the presence of C trachomatis in semen and alterations of some semen parameters. Further investigations should be performed to understand the disparities of first void urine and semen testing for detection of C trachomatis in males.
Spermatogenic Cycle Length and Sperm Production in a Feral Pig Species (Collared Peccary, Tayassu tajacu)
Authors: Costa Guilherme M. J. , Leal Marcelo C. , Silva Jurupytan V. , Cássia Ana , Ferreira S. , Guimarães Diva A. , França Luiz R.
Published: March 2010

ABSTRACT: Although the collared peccary (Tayassu tajacu) is found throughout the Americas, with a high potential for domestication and commercial exploitation, there are few data on the reproductive biology of this mammalian species. The aim of the present study was to investigate testis structure, spermatogenic cycle length, Sertoli cell efficiency, and spermatogenic efficiency. Twelve adult peccaries were used for biometrical, histological, and stereological analyses; 3 of these peccaries received intratesticular injections of 3H‐thymidine for the determination of the duration of spermatogenesis. Testis weight and gonadosomatic index were 23.7 ± 1.8 g and 0.2% ± 0.1%, respectively. Seminiferous tubule volume density was 77.4% ± 1.7%. Leydig cells occupied 12.8% ± 1.8% of the testis parenchyma and presented a peculiar cytoarchitecture in the periphery of the seminiferous tubule lobes. The premeiotic, meiotic, and postmeiotic stage frequencies were very similar to those found for wild and domestic boars. The spermatogenic cycle and entire spermatogenic process (based on 4.5 cycles) lasted approximately 12.3 ± 0.2 and 55.1 ± 0.7 days, respectively. Daily sperm production per gram of testis in the collared peccary was approximately 23.4 ± 2 × 106, which is similar to that of domestic and wild boars. The knowledge generated in the present study could be used in reproduction and animal improvement programs and provides important information that may be used for comparative reproductive biology with previously investigated mammalian species.
On Downey's conjecture
Authors: Arslanov Marat M. , Kalimullin Iskander Sh. , Lempp Steffen
Published: March 2010

We prove that the degree structures of the d.c.e. and the 3-c.e. Turing degrees are not elementarily equivalent, thus refuting a conjecture of Downey. More specifically, we show that the following statement fails in the former but holds in the latter structure: There are degreesf>e>d>0such that any degreeu≤fis either comparable with botheandd, or incomparable with both.