bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Antibiotic Treatment on Clinical Conditions and Bacterial Growth With Guided Tissue Regeneration
Authors: Demolon Isabelle A. , Persson G. Rutger , Moncla Bernard J. , Johnson Robert H. , Ammons William F.
Published: March 2012

Mucogingival flaps were reflected over pairs of mandibular molar teeth with Class II furcation invasions. The dimensions of the furcations were measured. The teeth were debrided and an expanded polytetrafluoroethylene (e‐PTFE) membrane was placed and retained over one furcation of each pair (test site) for 4 weeks. The second site served as a control. Eight patients (group 1) with 12 e‐PTFE sites received no antibiotic. Seven patients (group 2) with 12 e‐PTFE sites were administered amoxicillin/clavulanate potassium for 10 days. Paper‐points were used to collect bacterial samples and clinical indices were recorded at baseline and weekly for 4 weeks. Paper‐point samples and the e‐PTFE collected at week 4 were sonicated and analyzed by DNA probes for seven putative pathogens. At baseline no parameter showed statistical differences between groups or sites. At week 1 significantly greater levels of Prevotella intermedia type I (P <0.05) and Fusobacterium nucleatum (P <0.01) were found in group 1. At week 4, paper‐point samples from test sites (P <0.05) and e‐PTFE materials (P < 0.001) showed significantly higher presence of Bacteroides forsythus in group 1. No significant microbial changes were found for control sites over time or between groups. The total bacterial load at test sites over time increased similarly for patients administered or not administered the antibiotic. Clinical signs of inflammation were significantly greater in group 1 and associated with the presence of B. forsythus (P <0.01). J Periodontal 1993; 64:609–616.
Evaluation of a Counter‐Rotational Powered Brush in Patients in Supportive Periodontal Therapy
Authors: Yukna Raymond A. , Shaklee Roberta L.
Published: March 2012

In order to evaluate the effectiveness of a counter‐rotational powered brush (CRPB) during the supportive periodontal therapy (SPT) phase of periodontal treatment, 40 treated patients in SPT but with insufficient plaque control were randomly divided into equal experimental or control groups. All subjects used the same toothpaste, but the CRPB group did not use any interproximal aids. Gingivitis (MGI), plaque, and bleeding on probing (BOP) were scored at baseline and 1, 3, and 6 months prior to prophylaxis in conjunction with regular SPT visits. While both groups improved from baseline, CRPB use achieved significantly lower mean plaque scores and BOP at 6 months as analyzed by repeated measures ANOVA. The CRPB also showed consistent statistically superior percentage changes from baseline resulting in a general 50% improvement in clinical conditions compared to a 20 to 25% improvement for control oral hygiene methods. CRPB use resulted in at least a 50% improvement from baseline twice as often as did the control. The results of this study demonstrate more substantial and consistent improvement in periodontal conditions and plaque control effectiveness with the CRPB than the control methods that included interproximal hygiene aids. It appears that the CRPB may be a useful adjunct in maintaining reduced plaque levels and favorable gingival conditions in patients in the SPT phase of periodontal therapy. J Periodontol 1993; 64:859–864.
Microscopic and Chemical Analysis of Bone‐Hydroxyapatite Interface in a Human Retrieved Implant. A Case Report
Authors: Piattelli Adriano , Trisi Paolo
Published: March 2012

The aim of the present study was a histological and chemical analysis of the bonehydroxyapatite interface in a retrieved human implant. The implant was cut in two: one half was processed for light microscopy with the cutting grinding system, and the other for SEM analysis with EDX and a cathodoluminescence system. Bone maintained an intimate contact with the hydroxyapatite and the bonding of the hydroxyapatite with the metal was very strong. An analysis of the interface from a double staining (basic fuchsin and von Kossa) showed a non‐mineralized matrix, interposed between hydroxyapatite and bone in many areas. It is possible that different microscopic features are present in different areas of the interface, however, intimate contact was observed 6 months after insertion of the implant. J Periodontol 1993; 64:906–909.
Liquid-Liquid Equilibria of Solvent/Heavy Crude Systems: In Situ Upgrading and Measurements of Physical Properties
Authors: Nourozieh Hossein , Kariznovi Mohammad , Abedi Jalal
Published: March 2012

World production of heavy and extra heavy oils has increased as the production of conventional crudes declines. However, conventional oil recovery methods cannot effectively recover heavy oils due to their high viscosities. Different techniques for the recovery of these resources, such as enhanced solvent-steam-assisted-gravity-drainage (ES-SAGD), have been patented. The performance of these methods depends on the amount of solvent dissolved in the oil and its phase behavior properties.

Solvent-based recovery processes have lower green house gas emissions and can also contribute to in-situ upgrading of oil. The oil upgrading can be achieved either by the deasphalting or partitioning of the oil mixtures into two liquid phases in which higher grades of oil than the original oil produced. Experimental data on the phase behavior is needed to determine the operating conditions that cause the liquid-liquid system or in situ upgrading.

In the present study, the in situ upgrading of heavy oil using propane was experimentally determined at different temperatures and pressures. The effect of the solvent-to-oil ratio on equilibrium compositions and saturated phase properties were measured. The distributions of different components in both phases were observed with simulated distillation (SimDis) analysis. The amount and type of components that was extracted by propane has been investigated.

The experimental results showed that propane/oil mixtures partitions into a solvent and asphaltene-enriched phases at specific conditions. The SimDis data demonstrated that the oil was upgraded by the separation of the heavier constitutes with the light components extracted by the propane into a solvent-enriched phase. Recovery processes can, therefore, be designed in such a way that the valuable components are extracted from the heavy crude at specific in situ conditions, to produce higher grades of oil than original heavy oil.
Field Evaluation of MOV Adjustable Steam Chokes
Authors: Latif Faisal , Castrup Suzanne , Al Kalbani Ali
Published: March 2012

Controlling and monitoring steam injection into heavy oil reservoirs are important elements of heat management. Static chokes with tapered-bean inserts are the most reliable and cost-effective means of controlling wellhead steam injection rates. However, adjustable steam chokes are often used because Rate changes can be made without interruption of steam supply to the well.An inventory of bean inserts is not required.

Adjustable or multiple orifice valve (MOV) chokes have two disks, each with a pair of holes (orifices). The size of the choke opening is adjusted by rotating one disk causing the two pairs of holes on each disk to overlap by differing amounts. This paper presents the results of field tests conducted to assess the flow control and monitoring capability of MOV steam chokes. Topics include adjustment precision and reproducibility, critical and subcritical flow conditions, and comparison of calculated and measured flow rates.
Water Injector Matrix Acidizing: Evaluation of Tools Deployed on Coiled Tubing Used for Placement
Authors: Trehan Rakesh , Jones Norman , Meraz-Mata Vincent
Published: March 2012

Successful acid treatment depends largely on the method used to place the acid. Water-injection wells are commonly treated using coiled tubing (CT) and a high-pressure nozzle to increase the well's injection rate. This paper focuses on the comparison of two types of high-pressure nozzles, as used in a slotted-liner cleanout in a sandstone formation.

A majority of the diversion techniques available are classified as mechanical, such as straddle packers, opposing cup tools, particulates, and perforation ball sealers. In addition, the industry uses a variety of chemical diverters, such as gelled acids and foamed acid. These options might work fine in perforated and cemented casing, but there are not many effective options available with respect to matrix acidizing of long, uncemented slotted liners in sandstone formations.

CT acid jobs have typically used nozzles, such as the fixed nozzle, rotating-jet nozzle, and the fluid oscillating (FO) nozzle. However, the newest innovation in fluid-oscillating tools is the fluid-oscillating tuned frequency and amplitude (FOTFA) nozzle, which is more efficient than the previous fluid oscillating tuned frequency (FOTF) nozzles.

This paper presents case histories that compare the results of acid jobs using rotating jet nozzles and the latest FOTFA nozzles. Four analogous water-injection wells were chosen for the trial and were acid stimulated using CT. Two wells were acidized using a rotating nozzle and the other two with the FOTFA nozzle. The wells are in the same field and were treated using the same acid design and pumping procedures.
Experiments on Pulse Power Fracturing
Authors: Mao Ronghai , De Pater Hans , Leon Jean Francois , Fram Joe , Storslett Stein , Ewy Russ , Stefani Joe
Published: March 2012

Pressure pulses generated by sparks in water-filled boreholes generate hydraulic fractures in the dynamic regime. Using triaxially stressed model tests, we investigated the potential for multiple fracturing and the expected size of the fractures. In the tests, we determined the power level at which the pulse initiates a fracture and the final fracture geometry after applying many pulses. A dynamic fracture model is used to explain the attenuation of the pulses. Dynamic fracturing is still poorly understood. Lab tests are needed to benchmark simulation codes that predict fracture length and multiple fractures.

In the tests, we varied the number of notches in the wellbore, stress and rock type. Tests on blocks of cement and oil shale show that pulses of a few kJoule can generate pulses up to 50 MPa that induce multiple fractures and create fairly large fractures, depending on rock type. Bi-wing fractures were generated without notching the borehole. With 4-8 notches the fractures initiated from the notches. Attenuation of the pulses was found to depend mainly on turbulent friction in the fractures.

Pulse power has the advantage that it can generate many pulses in the same zone and can be applied quickly to stimulate multiple zones. This may be favorable compared with propellant fracturing. Pulse power fracturing may be used for stimulating very tight reservoirs, for improving breakdown or for initiating fractures at specific locations.
NFFLOW: A Reservoir Simulator Incorporating Explicit Fractures
Authors: Boyle E. J. , Sams W. N.
Published: March 2012

NFFLOW is a research code that quickly and inexpensively simulates flow in moderately fractured reservoirs. It explicitly recognizes fractures separately from rock matrix. In NFFLOW fracture flow is proportional to the pressure gradient along the fracture, and flow in the rock matrix is determined by Darcy's Law. The two flow mechanisms are coupled through the pressure gradient between a fracture and its adjacent rock matrix. Presented is a promising change to NFFLOW that allows for flow across a rock matrix block.
Design Considerations of Waterflood Conformance Control with Temperature-Triggered Low Viscosity Sub-Micron Polymer
Authors: Izgec O. , Shook G. M.
Published: March 2012

In waterfloods, the existence of highly conductive thief zones causes poor volumetric sweep efficiency, resulting in early breakthrough and excessive production of water. A conventional strategy of redirecting injection by closing off perforations yields short-term benefits because diversion occurs near the wellbore. As an alternative, temperature-triggered sub-micron polymers with low viscosity (popping agents), which gives an opportunity for conformance control deep in the reservoir, have been introduced in recent years. This technology aids conformance control by plugging the high permeability zones and diverting the fluid to the unswept portion of the reservoir.

Understanding the critical parameters that leads to a successful treatment and accurate determination of the slug size are two important criteria for a technically and economically successful treatment. In this study, first we investigate the effect of different parameters on the success of a conformance control treatment. A comprehensive design of experiments (DoE) study resolves the effects (and combined effects) of kv/kh, treatment fluid concentration, thief-to-matrix permeability ratio, mobility ratio and location of the placement in the reservoir. Next, a methodology is developed for accurate determination of the conformance slug size. The method is built on the temporal moment and residence time distribution analysis (RTDA) of interwell tracers. Dynamic flow- and storage-capacity curves are used to identify the optimum slug size.

3D thermal computer simulations show that thief-zone to matrix permeability ratio and placement location of the polymer are the most important parameters that affect the success of a treatment. The most desirable setting is placing the polymer deep in the reservoir, closer to the producer within high kv/kh reservoirs. Furthermore, the computer simulations confirm the power of the new optimum slug size determination technique. This new technique can avoid underestimation of the volume that needs to be treated which is critical for success of a treatment.
Economic valuation of benefits and costs associated with the coordinated development and management of the Zambezi river basin
Authors: Tilmant A. , Kinzelbach W. , Juizo D. , Beevers L. , Senn D. , Casarotto C.
Published: March 2012

The Zambezi river basin is of utmost importance to its riparian countries in terms of energy, food production and natural resources. Even though there is no legal agreement on the sharing of Zambezi waters, an assessment of basin-wide economically efficient allocation policies will provide valuable information at a time where water managers and policy makers in the region are negotiating the establishment of a unified river basin institution, called the Zambezi Watercourse Commission (ZAMCOM). That institution would be responsible for, amongst other things, the design of allocation rules. In this study, basin-wide allocation policies are derived from a hydro-economic model that considers the largest existing and planned hydraulic infrastructure and irrigation schemes in the basin. Our results illustrate that the economic value of water varies spatially, driven primarily by large changes in elevation and on the locations of existing or proposed dams. This observation may have implications for future decisions about the siting of expansions in irrigated agriculture. For example, some of the planned irrigation schemes in upstream countries are not economically sound if the power stations that are in an advanced planning phase are implemented. This study also reveals that the economic value of the three largest storage infrastructure (Kariba, Itezhitezhi, Cahora Bassa) is around US$443 million/year.
Sex-Specific Effect of Estrogen Sulfotransferase on Mouse Models of Type 2 Diabetes
Authors: Gao Jie , He Jinhan , Shi Xiongjie , Stefanovic-Racic Maja , Xu Meishu , O’Doherty Robert Martin , Garcia-Ocana Adolfo , Xie Wen
Published: March 2012

Estrogen sulfotransferase (EST), the enzyme responsible for the sulfonation and inactivation of estrogens, plays an important role in estrogen homeostasis. In this study, we showed that induction of hepatic Est is a common feature of type 2 diabetes. Loss of Est in female mice improved metabolic function in ob/ob, dexamethasone-, and high-fat diet–induced mouse models of type 2 diabetes. The metabolic benefit of Est ablation included improved body composition, increased energy expenditure and insulin sensitivity, and decreased hepatic gluconeogenesis and lipogenesis. This metabolic benefit appeared to have resulted from decreased estrogen deprivation and increased estrogenic activity in the liver, whereas such benefit was abolished in ovariectomized mice. Interestingly, the effect of Est was sex-specific, as Est ablation in ob/ob males exacerbated the diabetic phenotype, which was accounted for by the decreased islet β-cell mass and failure of glucose-stimulated insulin secretion in vivo. The loss of β-cell mass in ob/ob males deficient in Est was associated with increased macrophage infiltration and inflammation in white adipose tissue. Our results revealed an essential role of EST in energy metabolism and the pathogenesis of type 2 diabetes. Inhibition of EST, at least in females, may represent a novel approach to manage type 2 diabetes.
Dedicated detector for verification of X-ray energy in the linear accelerators for cargo screening and industrial radiography
Authors: Kaminski Przemyslaw , Wronka Slawomir
Published: March 2012

Dedicated detector for verification of X-ray energy in the linear accelerators for cargo screening and industrial radiography

The novel type of detector for X-ray energy evaluation has been developed. Thanks to a simultaneous analysis of the attenuation of X-rays by different thicknesses of well known material, the maximum energy of electrons on the conversion target can be deducted. Fast operation allows for pulse-to-pulse measurement, which is a must for modern, interlaced-energy cargo inspection systems. In this article the construction of the detector and software description are presented.
Application of recombination chambers for determination of neutron ambient dose equivalent at the door to the maze of linear accelerator vault
Authors: Jakubowska Edyta , Golnik Natalia , Gryzinski Michał , Tulik Piotr
Published: March 2012

Application of recombination chambers for determination of neutron ambient dose equivalent at the door to the maze of linear accelerator vault

Recombination chambers and 2202D Studsvik-Alnor reference remmeter were used for determination of ambient dose equivalent, H*(10) and its neutron and gamma components at the door to the maze of 15 MV medical accelerator. The measurements were performed at opened and partly closed door. The results showed that the ambient dose equivalent rate was 76.2 μSv h-1 at the opened door and only 2.7 μSv h-1 at slightly opened door, 2.5 m from the entrance to the maze.
Development of international coordination of research activities in the EU through ERA-NET and ERA-NET Plus: general trends and situtation in the Czech Republic
Authors: Havlíčková Lenka , Vavříková Lucie
Published: March 2012

Rozvoj mezinárodní koordinace výzkumných aktivit v EU prostřednictvím nástrojů ERA-NET a ERA-NET Plus: obecné trendy a situace v ČR

Projekty typu ERA-NET jsou nástrojem k propojení národních, regionálních a jiných dílčích výzkumných programů, intenzivnější propojení je pak realizováno schématy ERA-NET Plus a na základě čl. 185 Smlouvy o fungování EU. Článek se zabývá aktuální situací při realizaci těchto schémat. Zmiňuje vznik těchto projektů, jejich poslání a vysvětluje jejich rozsah. Formou mezinárodního srovnání analyzuje zapojení jednotlivých států do těchto projektů s důrazem na účast českých institucí. Vzhledem k nižšímu zapojení ČR se dále zabývá možnostmi české účasti. Přináší výsledky dotazníku ohledně zapojení do výzev, které jsou ve schématu ERA-NET vyhlašovány.
Data Analytical Processing in Data Warehouses
Authors: Rostek Katarzyna
Published: March 2012

Data Analytical Processing in Data Warehouses

The article presents issues connected with processing information from data warehouses (the analytical enterprise databases) and two basic types of analytical data processing in data warehouse. The genesis, main definitions, scope of application and real examples from business implementations will be described for each type of analysis. There will be presented copyrighted method of knowledge discovering in databases, together with practical guidelines for its proper and effective use in the enterprise.
Soil mechanical resistance measurement by an unique multi-cone tips horizontal sensor
Authors: Sharifi A. , Mohsenimanesh A.
Published: March 2012

Soil mechanical resistance measurement by an unique multi-cone tips horizontal sensor

Amulti-tips horizontal sensor was developed and mounted horizontally on a tine face by shafts. The length of shafts was reduced from top to down the tine. The developed system was evaluated in the controlled soil bin laboratory conditions with clay loam soil and uniform soil moisture content. The experiment was designed with soil compaction at three levels of uniform and non-uniform soil compaction in completely randomized block design with four replications. Vertical standard penetrometer was also used to compare with horizontal sensor data at whole working depth of 0 to 400 mm. The results indicated that there is a correlation with R2= 0.86 between soil cone penetrometer values and the horizontal soil mechanical resistance measurement system data. It can be concluded that the idea of reducing the length of the tips from top to down the tine face would give promising results.
Increasing the X-ray Diffraction Power of Protein Crystals by Dehydration: The Case of Bovine Serum Albumin and a Survey of Literature Data
Authors: Russo Krauss Irene , Sica Filomena , Mattia Carlo Andrea , Merlino Antonello
Published: March 2012

Serum albumin is one of the most widely studied proteins. It is the most abundant protein in plasma with a typical concentration of 5 g/100 mL and the principal transporter of fatty acids in plasma. While the crystal structures of human serum albumin (HSA) free and in complex with fatty acids, hemin, and local anesthetics have been characterized, no crystallographic models are available on bovine serum albumin (BSA), presumably because of the poor diffraction power of existing hexagonal BSA crystals. Here, the crystallization and diffraction data of a new BSA crystal form, obtained by the hanging drop method using MPEG 5K as precipitating agent, are presented. The crystals belong to space group C2, with unit-cell parameters a = 216.45 Å, b = 44.72 Å, c = 140.18 Å, β = 114.5°. Dehydration was found to increase the diffraction limit of BSA crystals from ~8 Å to 3.2 Å, probably by improving the packing of protein molecules in the crystal lattice. These results, together with a survey of more than 60 successful cases of protein crystal dehydration, confirm that it can be a useful procedure to be used in initial screening as a method of improving the diffraction limits of existing crystals.
The Effect of Osmolytes on Protein Fibrillation
Authors: Macchi Francesca , Eisenkolb Maike , Kiefer Hans , Otzen Daniel E.
Published: March 2012

Osmolytes are small molecules that are exploited by cells as a protective system against stress conditions. They favour compact protein states which makes them stabilize globular proteins in vitro and promote folding. Conversely, this preference for compact states promotes aggregation of unstructured proteins. Here we combine a brief review of the effect of osmolytes on protein fibrillation with a report of the effect of osmolytes on the unstructured peptide hormone glucagon. Our results show that osmolytes either accelerate the fibrillation kinetics or leave them unaffected, with the exception of the osmolyte taurine. Furthermore, the osmolytes that affected the shape of the fibrillation time profile led to fibrils with different structure as revealed by CD. The structural changes induced by Pro, Ser and choline-O-sulfate could be due to specific osmolytes binding to the peptides, stabilizing an otherwise labile fibrillation intermediate.
Comparison of Intraocular Pressure, Blood Pressure, Ocular Perfusion Pressure and Blood Flow Fluctuations During Dorzolamide Versus Timolol Add-On Therapy in Prostaglandin Analogue Treated Glaucoma Subjects
Authors: Januleviciene Ingrida , Siaudvytyte Lina , Diliene Vaida , Barsauskaite Ruta , Paulaviciute-Baikstiene Daiva , Siesky Brent , Harris Alon
Published: March 2012

Objective: To compare the effects of dorzolamide and timolol add-on therapy in open-angle glaucoma (OAG) patients previously treated with prostaglandin analogue (Pg), by evaluating fluctuations in the intraocular (IOP), blood (BP), ocular perfusion pressures (OPP) and retrobulbar blood flow (RBF) parameters. Methods: 35 OAG patients (35 eyes), 31 women (88.6%) age 63.3 (8.9) years were evaluated in a 3 month randomized, cross-over, single-masked study. During the experiments BP, heart rate, IOP and OPP were assessed 4 times per day (8–12–16–20 h). RBF was measured twice per day (8–20 h) using Color Doppler imaging in the ophthalmic (OA), central retinal (CRA), nasal (nSPCA) and temporal (tSPCA) posterior ciliary arteries. In each vessel, peak systolic velocity (PSV) and end-diastolic velocity (EDV) were assessed and vascular resistance (RI) calculated. Results: Both add-on therapies lowered IOP in a statistically significant manner from 15.7 ± 2.4 mmHg at latanoprost baseline to 14.9 ± 2.2 mmHg using dorzolamide (p < 0.001) and 14.2 ± 1.9 mmHg using timolol (p < 0.001). The IOP lowering effect was statistically significant at 20 h, favoring timolol as compared to dorzolamide (1.4 ± 2.4 vs. 0.2 ± 2.1 mmHg), (p < 0.05). Dorzolamide add-on therapy showed smaller IOP (2.0 ± 1.4), SPP (13.3 ± 7.9), systolic BP (13.5 ± 8.7) and diastolic BP (8.4 ± 5.4) fluctuations as compared to both latanoprost baseline or timolol add-on therapies. Higher difference between morning and evening BP was correlated to decreased evening CRA EDV in the timolol group (c = −0.41; p = 0.01). With increased MAP in the morning or evening hours, we found increased evening OA RI in timolol add-on group (c = 0.400, p = 0.02; c = 0.513, p = 0.002 accordingly). Higher MAP fluctuations were related to impaired RBF parameters during evening hours-decreased CRA EDV (c = −0.408; p = 0.01), increased CRA RI (c = 0.576; p < 0.001) and tSPCA RI (c = 0.356; p = 0.04) in the dorzolamide group and increased nSPCA RI (c = 0.351; p = 0.04) in the timolol add-on group. OPP fluctuations correlated with increased nSPCA RI (c = 0.453; p = 0.006) in the timolol group. OPP fluctuations were not related to IOP fluctuations in both add-on therapies (p < 0.05). Conclusions: Both dorzolamide and timolol add-on therapies lowered IOP in a statistically significant fashion dorzolamide add-on therapy showed lower fluctuations in IOP, SPP and BP. Higher variability of daytime OPP led to impaired RBF parameters in the evening.
“Secondary stem lengthening” in the palm Iriartea deltoidea (Arecaceae) provides an efficient and novel method for height growth in a tree form
Authors: Renninger Heidi J. , Phillips Nathan
Published: March 2012

• Premise of the study: Although traditionally assumed that all height growth in trees occurs at apical meristems, sequential measurement of internode lengths in the palm Iriartea deltoidea suggested that stems were lengthening long after the differentiation of tissues and far below the apical meristem. This observation is difficult to reconcile with the fact that neither the water‐conducting vessels nor the sugar‐transporting sieve tube cells are capable of lengthening after differentiation. However, the vascular bundles in palms form a spiral within the stem and could theoretically lengthen if the spiral “straightened”.

• Methods: We marked stretches of internodes on small and medium‐sized palms and measured their lengths over 2 years. Additionally, we collected material from small palms with short internodes and large palms with long internodes and made cross sections to determine the angle of vascular bundles within stems.

• Key results: We found that stems lengthened (up to 12% over 2 years) below the apical meristem in small and medium‐sized palms and that the spiral angle in vascular bundles of small palms was significantly larger than at the base of large palms indicating a straightening of the spiral.

• Conclusions: These results represent the first determination of “secondary lengthening” in tree stems as well as the most efficient method for height growth in terms of carbon investment. Likewise, elongation of stems allows palms to exhibit plasticity in height growth rates for more rapid growth when short‐lived canopy gaps are present than they would have with apical growth alone.
El poder de la estructura: edificio BBK Paraninfo
Authors: Losada R. , Egia E. , Rojí E. , Cuadrado J.
Published: March 2012

La última obra terminada por Álvaro Siza en España permite reflexionar sobre el valor del sistema estructural en la composición de formas y huecos, de vuelos y los movimientos de alineación de fachadas; en suma, de la creación del espacio arquitectónico y su envolvente.

El edificio BBK Paraninfo muestra un sistema estructural de láminas – muro, con forjados de estructura mixta (acero – hormigón), cimentación de losa de hormigón armado sobre pilotes barrenados.

La posición y dimensiones de huecos sin apoyos intermedios y las características de los vuelos dan lugar a una discontinuidad de transmisión de acciones, que requieren fuertes armaduras en secciones limitadas de hormigón, comportando una complejidad de ejecución y actuación frente a retracciones del hormigón.

Arquitectónicamente, la estructura pasa totalmente desapercibida en una arquitectura caracterizada por su simplicidad visual, complejidad espacial y constructiva, donde la luz natural y sus matices juegan un papel básico para la definición de espacios.
Technology Support for Knowledge Management in Industrial Settings
Authors: Saeed Saqib , Ahmad Rizwan , Mahmood Zaigham , Khan Mohammad Ayoub
Published: March 2012

The rapid innovation rate of industrial equipment, coupled with diversity of industrial processes and application areas, has introduced new constraints for management and workers in industrial settings. As a result, it is difficult to present a generic framework for knowledge management (KM) support in industrial environments. In this contribution, the authors briefly discuss KM in customer based organizations and highlight, in some detail, the factors that make Information Technology (IT) support particularly specific for KM in industrial settings. In order to design IT tools for effective knowledge sharing, there is a need for researchers to go beyond the theoretical frameworks and concepts. This requires a deep look at the knowledge sharing practices embedded in the work settings. It is suggested that there is a need for more empirical work in industrial settings to have a practice based analysis. The chapter also reviews the literature and provides guidelines for future research in the domain of technology support for KM in industrial settings.
E-Government
Authors: Sagheb-Tehrani Mehdi
Published: March 2012

Some state, national, and local governments around the world have long been playing active roles in the use of Information and Communication Technologies (ICTs) to stimulate economic development. Electronic government (e-Government) utilizes information technology (IT) to provide the necessary the access to a wide range of public services. Governments see IT as a way to improve the quality of life of their citizens. Today, governments at all levels of the governance hierarchy respond to millions of citizen demands electronically. Many public organizations are implementing e-Government projects. There is a need to put forward a conceptual model focusing on steps towards implementing more successful e-Government projects. This exploratory paper argues that several key success factors are appropriate for e-Government implementation. About twelve e-Government websites were examined using the identified key success factors. This chapter proposes a conceptual model for a better implementation of electronic government especially in the developing world context.
Trends in Government e-Authentication
Authors: Just Mike , Renaud Karen
Published: March 2012

Government engagement of its citizens through digital channels offers the potential for efficiencies and savings, while at the same time allowing the government to reach out to constituents in novel ways. Yet such endeavours must be undertaken with care, especially with personalised service delivery, which requires effective management of security and privacy. Proper authentication and management of identity are key related factors. In this chapter, the authors examine government use and adoption of e-authentication and identity management technologies in order to securely interact with citizens. They first provide some background in which the state-of-the-art for protecting and managing identities is reviewed in terms of the various methods studied in academia and marketed by industry. The chapter then describes the degree to which these methods have been, and continue to be, used in the e-government initiatives of several developed countries. Finally, the authors consider the lessons learned, and how they might be applied to similar initiatives in developing countries.
Visual Tweet
Authors: Ursyn Anna
Published: March 2012

“Visual Tweet: nature inspired visual statements” explores connections between science, computing, and art in a similar way as it is done in the previous chapter, “Looking at sciences through the water.” This chapter examines concepts and processes that relate to some fields in physics, biology, computing, and other sciences, and at the same time pertain to the planet’s life and humanity’s everyday experience. This chapter solves the projects visually, through art and/or graphics. Exploration of science-based concepts and nature-related processes support the understanding of the project themes, triggers imagination, and thus inspires enhancements to the ability to communicate with visual language and create artistic work. Comprehension of what is observed, the power of abstract thought, and an answer to evolving issues will result in personal visual projects – drawings, graphics, illustrations, animations, video clips, or web projects. This chapter comprises two projects about science-related themes: (1) Symmetry and pattern in animal world: geometry and art, and (2) Crystals and crystal caves. Each project invites the reader to create visual presentation of this theme.
Drawings from Small Beginnings
Authors: Dehlinger Hans
Published: March 2012

Small, densely arranged elements in large numbers are frequently observed phenomena in nature. The author uses an arbitrarily chosen stretch of landscape, a dry riverbed, to formulate artistic intentions and design programmed interpretations of them. From the database of recorded findings the author formulates concepts, which then transform into programs to generate drawings. Many different programs can satisfactorily assist in this task. The conceptual formulation is a crucial step in the procedural chain for attempts in generative art. This chapter experimentally addresses the formulation of a few concepts inspired by nature, aimed at generating line drawings executed on pen-plotters. Unlike in science and engineering, a piece of code does not produce a solution to a problem for concepts in generative art. Generative drawings are produced through a structured process including a sequence of discrete procedural steps, which are: finding and recording; concept and transformation; programming and testing; and drawing and interpretation.
A SURVEY OF CORE MEDICAL TRAINEES’ OPINIONS ON THE EPORTFOLIO RECORD OF EDUCATIONAL ACTIVITIES: BENEFICIAL AND COST-EFFECTIVE?
Authors: Johnson S , Cai A , Riley P , Millar LM , McConkey H , Bannister C
Published: March 2012

Objectives: To evaluate Core Medical Trainees’ (CMTs) opinions on the role of the ePortfolio in postgraduate education. Design and setting: Cross-sectional survey of 91 CMTs in five NHS trusts within the South Thames Deanery. Participants: Completed surveys were received from 80 Core Medical Trainees.

Results: A total of 84% agreed that an ongoing record of progress is necessary, only 5% felt the ePortfolio represents value for money; 78% of respondents were unclear as to how the Freedom of Information Act (2000) impacts on the ePortfolio, and most were uninformed of the extent to which their entries can be accessed by third parties.

Conclusions: Trainees recognise the importance of recording ongoing progress, but most consider the ePortfolio to be poor value for money. There is uncertainty regarding ownership of information held on ePortfolio, and to what extent it can be accessed. There are inadequate opportunities to discuss concerns. This requires further deliberation and until things are clarified, trainees may not fully engage with the resource.
Malignant mesothelioma presenting as a breast mass
Authors: Aujayeb A , Clague H , Pollock S , Stamenkovic S , Hughes A
Published: March 2012

We present a case of a male patient with a breast mass, found to be a malignant mesothelioma. We discuss the diagnostic challenges, the need for heightened awareness in suspected cases, the histological classification of mesotheliomas and the treatments available. We believe this to be the second reported case of a mesothelioma presenting as a breast mass.
Is the warfarin saga over?
Authors: Schulman S
Published: March 2012

Warfarin is the most widely used oral anticoagulant and has been available for more than 65 years. The last decade has brought a host of new orally available anticoagulants with promising features to clinical trials and some have already been approved for limited indications. As patients are starting to be switched to these new agents there is a need to gain understanding of the subsets of patients that will benefit the most from the new alternatives and whether warfarin is still the best choice for some subpopulations. With this knowledge we will provide the individual patient with the drug that has the best benefit/risk ratio at the same time as we conserve drug expenditures. This review discusses the directions we could follow in such a tailored anticoagulation approach, referring to the limited evidence when available.
The evolution of human skin colouration and its relevance to health in the modern world
Authors: Jablonski NG
Published: March 2012

Functionally naked skin which comes in a range of colours is unique to the human species. This review summarises current evidence pertaining to the evolution of these attributes. The biggest changes in the integument occurred during the course of human evolution in equatorial Africa, under regimes of high daytime temperatures and high ultraviolet radiation (UVR). Loss of most functional body hair was accompanied by the evolution of an epidermis with a specialised stratum corneum and permanent, protective, eumelanin pigmentation. The main reason for the evolution of dark pigmentation was to protect against folate deficiency caused by elevated demands for folate in cell division, DNA repair, and melanogenesis stimulated by UVR. Dispersal out of tropical Africa created new challenges for human physiology especially because of lower and more seasonal levels of UVR and ultraviolet B (UVB) outside of the tropics. In these environments, the challenge of producing a vitamin D precursor in the skin from available UVB was met by natural selection acting on mutations capable of producing varying degrees of depigmentation. The range of pigmentation observed in modern humans today is, thus, the product of two opposing clines, one favoring photoprotection near the equator, the other favoring vitamin D photosynthesis nearer the poles. Recent migrations and changes in lifestyle in the last 500 years have brought many humans into UVR regimes different from those experienced by their ancestors and, accordingly, exposed them to new disease risks, including skin cancer and vitamin D deficiency.
Promise cut short: the career of William Anderson
Authors: Beasley AW
Published: March 2012

This paper traces the career of William Anderson, naval surgeon and naturalist, who served in Cook’s ship Resolution on the second and final voyages, and died of tuberculosis high in the Arctic.
Daniel Carrion’s experiment: the use of selfinfection in the advance of medicine
Authors: Pamo OG
Published: March 2012

In 1885, Daniel Carrion (1857–1885), a young Peruvian medical student, was trying to establish the prodromal symptoms of ‘verruga disease’, an infectious disease rare outside South America but endemic in parts of Peru. As part of this investigation he was inoculated with fluid from a verruga lesion from a patient with the chronic form of the disease. He recorded the clinical features which developed, including fever, malaise, arthralgia, vomiting and anaemia, and it became apparent that he had developed the anaemic, febrile, acute phase of the illness (known as Oroya fever). This did not however progress in his case to the chronic form of the disease, and he died a few weeks later on 5 October 1885. His sacrifice served to establish, supposedly, that Oroya fever and verruga disease had a common aetiology and his death stimulated further research into the cause, now established as the bacterium Bartonella bacilliformis. Carrion is considered a martyr of Peruvian medicine and 5 October has been designated Peruvian Medicine Day in his honour.
Future challenges of representing land-processes in studies on land-atmosphere interactions
Authors: Arneth A. , Mercado L. , Kattge J. , Booth B.
Published: March 2012

Abstract. Over recent years, it has become increasingly apparent that climate change and air pollution need to be considered jointly for improved attribution and projections of human-caused changes in the earth system. Exchange processes at the land surface come into play in this context because many compounds that either act as greenhouse gases, as pollutant precursors, or both, have not only anthropogenic but also terrestrial sources and sinks. And since the fluxes of multiple gases and particulate matter between the terrestrial biota and the atmosphere are directly or indirectly coupled to vegetation and soil carbon, nutrient and water balances, quantification of their geographic patterns or changes over time requires due consideration of the underlying biological processes. In this review we highlight a number of critical aspects and recent progress in this respect, identifying in particular a number of areas where studies have shown that accounting for biological and ecological process understanding can alter global model projections of land-atmosphere interactions substantially. Specifically, this concerns the improved quantification of uncertainties and dynamic system responses, including acclimation, and the incorporation of exchange processes that so far have been missing from global models even though they are proposed to be of relevance for our understanding of terrestrial biota-climate feedbacks. Progress has also been made regarding studies on the impacts of land use/land cover change on climate change but the absence of a mechanistically-based representation of human response-processes limits our ability to analyse how climate change or air pollution in turn might affect human land use. A more integrated perspective is necessary and should become an active area of research that bridges the socio-economic and biophysical communities.
Distributions of dissolved trace metals (Cd, Cu, Mn, Pb, Ag) in the southeastern Atlantic and the Southern Ocean
Authors: Boye M. , Wake B. D. , Lopez Garcia P. , Bown J. , Baker A. R. , Achterberg E. P.
Published: March 2012

Abstract. Comprehensive synoptic datasets (surface water down to 4000 m) of dissolved cadmium (Cd), copper (Cu), manganese (Mn), lead (Pb) and silver (Ag) are presented along a section between 34° S and 57° S in the southeastern Atlantic Ocean and the Southern Ocean to the south off South Africa. The vertical distributions of Cu, Ag, and of Cd display nutrient-like profiles similar to silicic acid, and phosphate, respectively. The distribution of Mn shows a subsurface maximum in the oxygen minimum zone, whereas Pb concentrations are rather invariable with depth. Dry deposition of aerosols is thought to be an important source of Pb to surface waters close to South Africa, and dry deposition and snowfall may have been significant sources of Cu and Mn at the higher latitudes. Furthermore, the advection of water-masses enriched in trace metals following contact with continental margins appeared to be an important source of trace elements to the surface, intermediate and deep waters in the southeastern Atlantic Ocean and the Antarctic Circumpolar Current. Hydrothermal inputs appeared to have formed a source of trace metals to the deep waters over the Bouvet Triple Junction ridge crest, as suggested by relatively enhanced dissolved Mn concentrations. The biological utilization of Cu and Ag was proportional to that of silicic acid across the section, suggesting that diatoms formed an important control over the removal of Cu and Ag from surface waters. However uptake by dino- and nano-flagelattes may have influenced the distribution of Cu and Ag in the surface waters of the subtropical Atlantic domain. Cadmium correlated strongly with phosphate (P), yielding lower Cd/P ratios in the subtropical surface waters where phosphate concentrations were below 0.95 μM. The greater depletion of Cd relative to P observed in the Weddell Gyre compared to the Antarctic Circumpolar Current could be due to increase Cd-uptake induced by iron-limiting conditions in these High-Nutrient Low-Chlorophyll waters. Similarly, an increase of Mn uptake under Fe-depleted conditions may have caused the highest depletion of Mn relative to P in surface waters of the Weddell Gyre. In addition, a cellular Mn-transport channel of Cd was possibly activated in the Weddell Gyre, which in turn may have yielded depletion of both Mn and Cd in these surface waters.
Parameterization of atmospheric long-wave emissivity in a mountainous site for all sky conditions
Authors: Herrero J. , Polo M. J.
Published: March 2012

Abstract. Long-wave radiation is an important component of the energy balance of the Earth's surface. The downward component, emitted by the clouds and aerosols in the atmosphere, is rarely measured, and is still not well understood. In mountainous areas, the models existing for its estimation through the emissivity of the atmosphere do not give good results, and worse still in the presence of clouds. In order to estimate this emissivity for any atmospheric state and in a mountainous site, we related it to the screen-level values of temperature, relative humidity and solar radiation. This permitted the obtaining of: (1) a new set of parametric equations and (2) the modification of the Brutsaert's equation for cloudy skies through the calibration of C factor to 0.34 and the parameterization of the cloud index N. Both fitted to the surface data measured at a weather station at a height of 2500 m a.s.l. in Sierra Nevada, Spain. This study analyzes separately three significant atmospheric states related to cloud cover, which were also deduced from the screen-level meteorological data. Clear and totally overcast skies are accurately represented by the new parametric expressions, while the intermediate situations corresponding to partly clouded skies, concentrate most of the dispersion in the measurements and, hence, the error in the simulation. Thus, the modeling of atmospheric emissivity is greatly improved thanks to the use of different equations for each atmospheric state.