bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient simulation of tail probabilities of sums of dependent random variables
Authors: Blanchet Jose H. , Rojas-Nandayapa Leonardo
Published: October 2011

We study asymptotically optimal simulation algorithms for approximating the tail probability of P(eX1+⋯+ eXd>u) asu→∞. The first algorithm proposed is based on conditional Monte Carlo and assumes that (X1,…,Xd) has an elliptical distribution with very mild assumptions on the radial component. This algorithm is applicable to a large class of models in finance, as we demonstrate with examples. In addition, we propose an importance sampling algorithm for an arbitrary dependence structure that is shown to be asymptotically optimal under mild assumptions on the marginal distributions and, basically, that we can simulate efficiently (X1,…,Xd|Xj>b) for largeb. Extensions that allow us to handle portfolios of financial options are also discussed.
Checkpointing for the RESTART problem in Markov networks
Authors: Lipsky Lester , Doran Derek , Gokhale Swapna
Published: October 2011

We apply the known formulae of the RESTART problem to Markov models of software (and many other) systems, and derive new equations. We show how checkpoints might be included, with their resultant performance under RESTART. The result is a complete procedure for finding the mean, variance, and tail behavior of the job completion time as a function of the failure rate. We also provide a detailed example.
Population-size-dependent, age-structured branching processes linger around their carrying capacity
Authors: Jagers Peter , Klebaner Fima C.
Published: October 2011

Dependence of individual reproduction upon the size of the whole population is studied in a general branching process context. The particular feature under scrutiny is that of reproduction changing from supercritical in small populations to subcritical in large populations. The transition occurs when the population size passes a critical threshold, known in ecology as the carrying capacity. We show that populations either die out directly, never coming close to the carrying capacity, or grow quickly towards the carrying capacity, subsequently lingering around it for a time that is expected to be exponentially long in terms of a carrying capacity tending to infinity.
Duality results for Markov-modulated fluid flow models
Authors: Ahn Soohan , Ramaswami Vaidyanathan
Published: October 2011

We establish some interesting duality results for Markov-modulated fluid flow models. Though fluid flow models are continuous-state analogues of quasi-birth-and-death processes, some duality results do differ by the inclusion of a scaling factor.
Decay rates for some quasi-birth-and-death processes with phase-dependent transition rates
Authors: Motyer Allan J. , Taylor Peter G.
Published: October 2011

Recently, there has been considerable interest in the calculation of decay rates for models that can be viewed as quasi-birth-and-death (QBD) processes with infinitely many phases. In this paper we make a contribution to this endeavour by considering some classes of models in which the transition function is not homogeneous in the phase direction. We characterize the range of decay rates that are compatible with the dynamics of the process away from the boundary. In many cases, these rates can be attained by changing the transition structure of the QBD process at level 0. Our approach, which relies on the use of orthogonal polynomials, is an extension of that in Motyer and Taylor (2006) for the case where the generator has homogeneous blocks.
Regeneration of the adult zebrafish brain from neurogenic radial glia-type progenitors
Authors: Kroehne Volker , Freudenreich Dorian , Hans Stefan , Kaslin Jan , Brand Michael
Published: October 2011

Severe traumatic injury to the adult mammalian CNS leads to life-long loss of function. By contrast, several non-mammalian vertebrate species, including adult zebrafish, have a remarkable ability to regenerate injured organs, including the CNS. However, the cellular and molecular mechanisms that enable or prevent CNS regeneration are largely unknown. To study brain regeneration mechanisms in adult zebrafish, we developed a traumatic lesion assay, analyzed cellular reactions to injury and show that adult zebrafish can efficiently regenerate brain lesions and lack permanent glial scarring. Using Cre-loxP-based genetic lineage-tracing, we demonstrate that her4.1-positive ventricular radial glia progenitor cells react to injury, proliferate and generate neuroblasts that migrate to the lesion site. The newly generated neurons survive for more than 3 months, are decorated with synaptic contacts and express mature neuronal markers. Thus, regeneration after traumatic lesion of the adult zebrafish brain occurs efficiently from radial glia-type stem/progenitor cells.
Predicting condom use in young women: demographics, behaviours and knowledge from a population-based sample in Brazil
Authors: Miranda A E , Figueiredo N C , McFarland W , Schmidt R , Page K
Published: October 2011

The goal of this study was to assess condom use and related behaviour in young women in Vitória, Brazil. From March to December 2006, a cross-sectional sample of women aged 18–29 years was recruited into a population-based study. Risk behaviours for HIV and sexually transmitted infections (STIs) were surveyed. Condom use at last intercourse was assessed as a principal outcome describing protective sexual behaviour. Of 1200 eligible women identified, 1029 (85.8%) enrolled. Among them, 904 (87.9%) reported a history of sexual activity. Only 36.6% reported condom use at last intercourse; those who did were more likely to report commercial sex work (odds ratio [OR] 9.01 [1.46–55.55]), to state that STI prevention was a primary reason for using condoms (OR = 6.84 [4.81–9.71]), to have been previously diagnosed with an STI (OR = 2.39 [1.36–4.21]), to report that ‘it is easy to tell a sexual partner they will not have vaginal/anal sex without a condom’ (OR = 2.30 [1.56–3.39]), to report that sexual intercourse is only risky when people have anal sex (OR = 1.98 [1.22–3.22]); and less likely to be married (OR = 0.65 [0.54–0.78]), and to find it difficult to use condom consistently in all sexual encounters (OR = 0.36 [0.25–0.52]). Women who reported condom use were more concerned with preventing STIs, and to report less difficulty insisting on condom use with partners.
Developing quality indicators for genitourinary medicine services with patient and public involvement: an audit of performance against proposed local measures
Authors: Challenor R , Warwick Z
Published: October 2011

Local service quality indicators (SQIs) for both genitourinary (GU) medicine and HIV were drawn up using patient and public involvement (PPI). Our clinic's performance was audited against these SQIs. All measures were achieved, almost achieved or probably achieved. SQIs need to be challenging yet achievable and it is difficult to judge precisely where standards should be set. This paper provides a first estimate for our service after PPI. We hope other services may wish to audit performance against these SQIs. If such data were to be pooled, there would be valuable evidence for setting ‘SMART’ (specific, measurable, attainable, relevant and time-based) SQIs that are challenging yet achievable for the majority of clinics. If the bar were to be set correctly, the actual performance of clinics ought generally to lie just above or just below the set standard.
Condom use and sexually transmitted infections among Malagasy sex workers
Authors: Turner A N , Feldblum P , Hoke T H
Published: October 2011

We evaluated whether use of a short- or longer-term recall period for condom use was superior for assessing risk of acquisition of incident sexually transmitted infection (STI). Female sex workers ( n = 1000) in Madagascar took part in a randomized trial comparing counselling strategies for male and female condom promotion. We explored associations between women's self-reported condom use with clients and non-paying partners and incident STI, examining both short-term recall (last sex act) and longer-term recall (over the past month and year). Self-reported condom use was generally not associated with reduced STI risk, whether measured at the last act or over longer time periods; with clients or non-paying partners; and through unadjusted and adjusted modelling. No condom use measure (short versus longer time periods, with one or both partner types) was strongly predictive of STI, suggesting poor validity.
Primary Stability of a Dynamic Artificial Disc Tested in a Human Cadaveric Model
Authors: Thompson R. E. , Schwarzenbach O. , Seebeck J. , Fröhlich M.
Published: October 2011

Sufficient anchorage of an interbody device will allow osseointegration and avoid implant migration. Shear forces in the lumbar spine are transferred across the bone/implant interface, resulting in relative motion between the implant and bone. Relative motion greater than 150 μm will have a detrimental effect on the osseointegration of titanium (Ti) implants. This study developed an in vitro, primary stability testing protocol to assess a total disc replacement (TDR). Testing was performed on seven human cadaveric L4 and L5 vertebrae. Cyclic shear loading of the prepared implant/bone interface was applied for 20 cycles in the anterior and posterior directions to ±350 N under an axial compressive load of 600 N. The relative motion was measured and the average of the last five cycles analysed. The shear force necessary to cause complete anterior migration of the TDR was also measured. The averaged cyclic motion for the last five cycles in both the anterior and posterior directions was below 85 μm for all specimens. The average yield force for complete anterior implant migration was 522.2 N (±105.9 N) and the failure force was 605.1 N (±118.4 N). A primary stability testing protocol was developed and employed to assess a TDR in human cadaveric bone. The measured relative motion for this TDR for each loading cycle was below 150 μm, which is favourable for osseointegration with the vertebral body endplates.
Acylated/unacylated ghrelin ratio in cord blood: correlation with anthropometric and metabolic parameters and pediatric lifespan comparison
Authors: Bellone S , Prodam F , Savastio S , Avanzo D , Pagani A , Trovato L , Walker G E , Genoni G , Bona G
Published: October 2011

Context

Ghrelin is a peptide with multiple functions that circulates in acylated (AG) and unacylated (UAG) forms. However, the role of ghrelin in neonates (NN) remains to be clarified.

Objective

The aim of this study was to determine ghrelin concentrations of the two forms in NN to clarify their biological roles. As such, ghrelin levels at birth were compared with those in later life.

Setting and design

Tertiary Care Center. In this cross-sectional study, we evaluated AG, UAG, AG/UAG ratio, and insulin levels in venous cord blood from NN and in fasted normal weight (NW) and obese (OB) children, both prepubertal and pubertal.

Subjects

We studied 82 NN, 82 NW, and 58 OB children.

Results

AG levels were lower in NN than in NW and OB children (P<0.0001), more specifically the prepubertal NW and OB children (P<0.0001). UAG levels were higher in NN than in NW and OB children (P<0.0001). Therefore, the AG/UAG ratio was lower in NN than in NW and OB children (P<0.0001). NN showed insulin levels similar to NW and lower than OB children (P<0.0001). At birth UAG was positively correlated with AG (Pearson: 0.425; P<0.0001) and negatively with insulin (−0.253; P<0.02). In NW and OB, UAG and AG were positively correlated to each other and negatively correlated with insulin and body mass index (−0.566; P<0.0001).

Conclusions

NN compared with children, showed higher UAG and lower AG levels. The AG/UAG ratio showed a very different profile in NN, being lower than in NW and OB children, thus suggesting a different metabolic function for the two forms in NN. Further studies are needed to clarify the exact role of the different ghrelin forms in NN.
Spread of Methicillin-ResistantStaphylococcus aureusin a Large Tertiary NICU: Network Analysis
Authors: Geva Alon , Wright Sharon B. , Baldini Linda M. , Smallcomb Jane A. , Safran Charles , Gray James E.
Published: October 2011

OBJECTIVE:

Methicillin-resistant Staphylococcus aureus (MRSA) colonization in NICUs increases the risk of nosocomial infection. Network analysis provides tools to examine the interactions among patients and staff members that put patients at risk of colonization.

METHODS:

Data from MRSA surveillance cultures were combined with patient room locations, nursing assignments, and sibship information to create patient- and unit-based networks. Multivariate models were constructed to quantify the risk of incident MRSA colonization as a function of exposure to MRSA-colonized infants in these networks.

RESULTS:

A MRSA-negative infant in the NICU simultaneously with a MRSA-positive infant had higher odds of becoming colonized when the colonized infant was a sibling, compared with an unrelated patient (odds ratio: 8.8 [95% confidence interval [CI]: 5.3–14.8]). Although knowing that a patient was MRSA-positive and was placed on contact precautions reduced the overall odds of another patient becoming colonized by 35% (95% CI: 20%–47%), having a nurse in common with that patient still increased the odds of colonization by 43% (95% CI: 14%–80%). Normalized group degree centrality, a unitwide network measure of connectedness between colonized and uncolonized patients, was a significant predictor of incident MRSA cases (odds ratio: 18.1 [95% CI: 3.6–90.0]).

CONCLUSIONS:

Despite current infection-control strategies, patients remain at significant risk of MRSA colonization from MRSA-positive siblings and from other patients with whom they share nursing care. Strategies that minimize the frequency of staff members caring for both colonized and uncolonized infants may be beneficial in reducing the spread of MRSA colonization.
Effectiveness of a School Nurse–Delivered Smoking-Cessation Intervention for Adolescents
Authors: Pbert Lori , Druker Susan , DiFranza Joseph R. , Gorak Diane , Reed George , Magner Robert , Sheetz Anne H. , Osganian Stavroula
Published: October 2011

OBJECTIVE:

To evaluate the effectiveness of a school nurse–delivered smoking-cessation intervention in increasing abstinence among adolescent smokers.

METHODS:

Thirty-five high schools were pair-matched and randomly assigned to 1 of 2 conditions, each of which consisted of 4 visits with the school nurse: (1) counseling intervention using the 5 A's model and cognitive-behavioral techniques; or (2) an information-attention control condition. Adolescents (n = 1068) who reported past 30-day smoking and interest in quitting completed surveys at baseline and at 3 and 12 months and provided saliva samples for biochemical validation of reported smoking abstinence.

RESULTS:

Intervention condition participants were almost twice as likely to be abstinent per self-report at 3 months (odds ratio: 1.90 [95% confidence interval: 1.12–3.24]; P = .017) compared with control participants; at 12 months there were no differences. The difference at 3 months was driven by quit rates in male students (15.0% [intervention] vs 4.9% [control]; odds ratio: 3.23 [95% confidence interval: 1.63–6.43]; P = .001); there was no intervention effect in female students at either time point (6.6% vs 7.0% at 3 months and 16.6% vs 15.5% at 12 months) and no intervention effect in male students at 12 months (13.9% vs 13.2%). Smoking amount and frequency decreased significantly in intervention compared with control schools at 3 but not at 12 months.

CONCLUSIONS:

A school nurse–delivered smoking-cessation intervention proved feasible and effective in improving short-term abstinence among adolescent boys and short-term reductions in smoking amount and frequency in both genders. Additional research is needed to enhance both cessation and maintained abstinence.
Effects of Oxygen and Forming Gas Annealing on ZnO TFTs
Authors: Huang Jiaye , Radhakrishna Ujwal , Lemberger Martin , Jank Michael P.M. , Polster Sebastian , Ryssel Heiner , Frey Lothar
Published: October 2011

ZnO TFTs with bottom gate top S/D contact architecture were fabricated by sputtering of ZnO with layer thicknesses from 30 nm to 100 nm. The effect of post deposition annealing in oxygen and forming gas atmospheres at 400°C to 500°C on the devices was investigated. The tendencies of a lower threshold voltage Vth and a higher saturation mobility μsat for higher annealing temperature can be observed for both oxygen and forming gas annealing. Reduction of trap density in oxygen annealing and additional hydrogen incorporation in forming gas annealing play an important role for these electrical parameters. Morphological changes of increased grain size and fewer grain boundaries in the channel also contribute to tendencies in electrical characteristics of ZnO TFTs.
Characteristics of OTFTs Using Olefin-polymer Gate Insulator and Their Application to a 5-in. OTFT-driven Flexible AMOLED Display
Authors: Nakajima Yoshiki , Fujisaki Yoshihide , Takei Tatsuya , Sato Hiroto , Nakata Mitsuru , Suzuki Mitsunori , Fukagawa Hirohiko , Motomura Genichi , Shimizu Takahisa , Sugitani Koichi , Isogai Yukie , Katoh Takeyoshi , Yamamoto Toshihiro , Fujikake Hideo , Tokito Shizuo
Published: October 2011

Organic thin-film transistors (OTFTs) using cross-linked olefin polymer as a gate insulator were fabricated on a plastic film. An olefin polymer layer was formed by spin-coating and baking at temperatures below 150°C. Pentacene was used as an organic semiconductor layer. The fabricated OTFTs with a short 5-μm-long channel showed a mobility of 0.1-0.2 cm2/Vs and a current ON/OFF ratio of 107. These OTFTs also exhibited good stable performance in the atmosphere. On the basis of the results, we fabricated a 5 inches OTFT-driven flexible active-matrix organic light emitting diode (AMOLED) display. The gate insulator, some metal wirings and electrodes on the OTFT backplane were formed on the plastic film by photolithography. After fabrication of the OTFT backplane, OLED layers were formed by vacuum deposition through a shadow-mask. Clear color moving images were observed on the flexible display even when it was bent.
Pulsed Laser Deposition of Silicon Nanostructures
Authors: Bruno P. , Salve T. , Russo V. , Dellasega D. , Filoni G. , Casari C.S. , Bottani C.E. , Bassi A. Li
Published: October 2011

Silicon nanostructures embedded in an amorphous matrix have been synthesized by Pulsed Laser Deposition (PLD) at room temperature. The structural and optical properties of the materials were tailored by varying deposition parameters; attention has been devoted to the nanoscale morphology of the Si layers which has been varied from compact to open-porous by changing background gas (Ar) pressure (1-100 Pa). An adopted simple-minded strategy of a compact Si layer deposited on top of nanostructured layers showed to reduce quite successfully ex-situ oxidation. Raman spectroscopy suggests that as deposited samples are mainly constituted by amorphous silicon with nanocrystals (NCs) inclusions. The results indicate that the average size of the Si NCs varies in the range 2-6 nm. Photoluminescence (PL) responses are found to be strictly dependent on morphology and strengthen up the idea of the quantum confinement effect in the obtained nanostructured material. The results are interpreted in terms of particle size distribution, crystallinity and partial surface oxidation of the silicon nanostructures.
Non-idealities in Graphene/p-silicon Schottky-barrier Solar Cells
Authors: Lin Derek Y.T. , Shambayati Shabnam , Kiasari Nima Mohseni , Pulfrey David L. , Servati Peyman
Published: October 2011

This paper presents fabrication details and preliminary experimental results for graphene/p-silicon Schottky-barrier solar cells, where graphene is used as a transparent electrode and forms a rectifying junction with silicon wafer. Deviations from expected Schottky behavior in the form of large diode-ideality factors and s-shaped current-voltage curves observed in measurements are reported and analyzed.
Vortex Pinning and Dynamics in HTS films: Role of Extended Linear Defects
Authors: Kasatkin Alexander L. , Tretiatchenko Constantin G. , Pan Volodymyr M.
Published: October 2011

The model of single vortex escape from extended linear defect and subsequent vortex dynamics under the Lorentz force action in a rather thick (d > 2λ) 3D anisotropic superconductor is developed. We consider the case of parallel c-oriented linear defects as well as the case of equidistant linear row of such kind of defects, which represents the dislocation model of low-angle [001] tilt grain boundary in HTS films and bicrystals. The suggested model based on the classical mechanics approach allows to describe behavior of an elastic vortex string in the potential well of linear defect and under the action of Lorentz force on its end within the Meissner current carrying layer and to determine the depinning critical current density at low magnetic fields and temperatures.
Influence of a dominant consumer species reverses at increased diversity
Authors: Brandt Margarita , Witman Jon D. , Chiriboga Angel I.
Published: October 2011

Theory and experiments indicate that changes in consumer diversity affect benthic community structure and ecosystem functioning. Although the effects of consumer diversity have been tested in the laboratory and the field, little is known about effects of consumer diversity in the subtidal zone, one of the largest marine habitats. We investigated the grazing effects of sea urchins on algal abundance and benthic community structure in a natural subtidal habitat of the Galápagos Islands. Three species of urchins (Eucidaris,Lytechinus, andTripneustes) were manipulated in inclusion cages following a replacement design with three levels of species richness (one, two, and three species) with all possible two‐species urchin combinations. Identity was the main factor accounting for changes in the percentage of substrate grazed and benthic community structure. Two out of the three two‐species assemblages grazed more than expected, suggesting a richness effect, but analyses revealed that this increased grazing was due to a sampling effect of the largest and commercially valued urchin species,Tripneustes. Benthic community structure in treatments withEucidaris,Lytechinus, andTripneustesalone was significantly different at the end of the experiment, suggesting that resource use differentiation occurred. Communities inTripneustesenclosures were characterized by abundant crustose coralline algae and grazed substrate, while those without it contained abundant green foliose algae (Ulvasp.). An unexpected emergent property of the system was that the most species‐rich urchin assemblage underyielded, grazing less than any other assemblage withTripneustes, effectively reversing its dominant influence observed in the two‐species treatments. While further experiments are needed to discern the mechanisms of underyielding, it may be related to changing interspecific interactions as richness increases from two to three species or to density‐dependentTripneustesgrazing. This study highlights the general importance of evaluating consumer richness effects across the entire range of species richness considered, as the performance of the most species‐rich consumer assemblage could not be predicted by manipulations of intermediate levels of consumer species richness.
Robustness of variance and autocorrelation as indicators of critical slowing down
Authors: Dakos Vasilis , van Nes Egbert H. , D'Odorico Paolo , Scheffer Marten
Published: October 2011

Ecosystems close to a critical threshold lose resilience, in the sense that perturbations can more easily push them into an alternative state. Recently, it has been proposed that such loss of resilience may be detected from elevated autocorrelation and variance in the fluctuations of the state of an ecosystem due to critical slowing down; the underlying generic phenomenon that occurs at critical thresholds. Here we explore the robustness of autocorrelation and variance as indicators of imminent critical transitions. We show both analytically and in simulations that variance may sometimes decrease close to a transition. This can happen when environmental factors fluctuate stochastically and the ecosystem becomes less sensitive to these factors near the threshold, or when critical slowing down reduces the ecosystem's capacity to follow high‐frequency fluctuations in the environment. In addition, when available data is limited, variance can be systematically underestimated due to the prevalence of low frequencies close to a transition. By contrast, autocorrelation always increases toward critical transitions in our analyses. To exemplify this point, we provide cases of rising autocorrelation and increasing or decreasing variance in time series prior to past climate transitions.
Life Without Barite: Ten Years of Drilling Deep HPHT Gas Wells With Cesium Formate Brine
Authors: Downs John
Published: October 2011

The tradition of using barite to increase the weight of drilling fluids dates back to the early-1920's and, while it has been of great benefit to the oil industry over the past 90 years, it has also caused some chronic and persistent well construction problems along the way. These problems, which are very familiar to drillers, include well control difficulties, stuck pipe incidents and formation damage.

The oil industry has known since the 1970's that replacing barite with suitable non-damaging solutes in reservoir drill-in fluids is an effective way of reducing formation damage, simplifying operations and eliminating the need for expensive formation damage by-pass operations. The development of brine-based drill-in fluids opened up the opportunity to connect more effectively with hydrocarbon reserves by allowing the construction of long high-angle reservoir sections completed in open hole. Despite the advantages on offer, the industry was unable to exploit this novel technology in deep HPHT gas field developments until the mid-to late-1990's when drill-in fluids based on potassium and cesium formate brine became available in commercial volumes.

Cesium formate brine was first used as a reservoir drilling fluid in the Huldra gas/condensate field in the North Sea in January 2001, and has now been used to drill a total of 29 deep HPHT gas wells. The information presented and reviewed in this paper confirms that the use of potassium and cesium formates as the sole weighting agents in reservoir drill-in fluids has enabled operators to enjoy the full economic benefits of creating low-skin open-hole completions in deep high-angle HPHT gas wells. The review also concludes that the use of these heavy formate brines as drill-in fluids over the past 10 years has facilitated the safe and efficient development of deep HPHT gas reserves by:

Virtually eliminating well control and stuck pipe incidents Enabling the drilling of long high-angle HPHT wells with narrow drilling windows Typically reducing offshore HPHT well completion times by 30 days or more Improving the definition and visualization of the reservoirs Eliminating the need for clean-ups, stimulation treatments or any other form of post-drilling well intervention to remove formation damage caused by the drilling fluid

This has all been made possible by the operators’ acceptance and adoption of the award-winning Chemical Leasing (ChL) and fluid management programmes that form the basis of their contracts with the sole producer of cesium formate brine. The use of the ChL model has played an important role in reducing the unnecessary consumption of what is a very rare and valuable chemical resource
Recent Advances in ADME Predictions
Authors: Molnar Laszlo , M. Keseru Gyorgy
Published: October 2011

The basic objective of medicinal chemistry is to deliver not only potent in vitro chemicals, but also,
more importantly, drug candidates that can be progressed to clinical trials and that will eventually reach the
market. This is a long and winding road – one that is often tricky to follow and that sometimes reaches a dead
end. Over the past few decades, the pharmaceutical industry has learned that ADME and related parameters are of
pre-eminent importance in selecting a successful candidate. This chapter briefly discusses the most important
physico-chemical and other more complex ADME parameters, while focusing on in silico prediction. Historical
approaches are mentioned, but, as the title suggests, the emphasis is on recent advances. The authors’ intention is
to help medicinal chemists to achieve their goal of identifying new therapeutic options for human diseases.
Solubility as a Challenge in Drug Research and Development
Authors: Sandor Halász Attila
Published: October 2011

In the last several decades, drug research and development have faced a number of issues related to the
pharmacokinetics of new chemical entities. Numerous new drug candidates have been reported to have failed in
human clinical phases (mainly phase I) after oral administration due to ineffectiveness caused by unsatisfactory
pharmacokinetics. The same problem is also occurring during preclinical research and development. It has been
clearly demonstrated that solubility is one of the major factors affecting the in vivo systemic exposure of drug
candidates. Drug companies usually aim to develop oral products, as this is the preferred administration route for
medicines. The main administration route in the preclinical phase is also oral. Solubility is an issue not only in
human clinical phases, but also in the preclinical stage. Keeping the factors affecting solubility in mind can help
the researcher to achieve a satisfactory level of drug exposure. This chapter addresses the theoretics of solubility
and the internal and external factors concerning the dissolution process, such as morphology, particle size, surface
area, pH, ionic strength and surfactants. At the end of the chapter, there is a short overview of the practice of
solubility measurement.
Intestinal Absorption and Models of Penetration
Authors: Hellinger Eva , Vastag Monika
Published: October 2011

A high enough level of bioavailability (BA) is a prerequisite in order for a drug to take effect. Absolute
bioavailability is the fraction of a dose that reaches systemic circulation following oral administration. The key
determinants of the systemically available drug level are the amount of the dose that enters the enterocytes and
the fraction that escapes as a result of metabolism by the gut wall and/or the liver. Body biology, drug properties
and formulation factors all influence the outcome. In silico, in vitro and in vivo models for drug screening have
been developed and are able to provide predictions for human absorption in accordance with the degree of
complexity of the model.

This chapter provides a summary of the drug properties and biological variables in the gastrointestinal tract that
influence drug absorption, and summarises the key models that have been developed and are in use for screening
and predicting intestinal drug absorption.
Membrane and Dye Efflux Assays to Detect and Characterize the Interaction of Drugs with ABC Transporters
Authors: Ioja Eniko , Nagy Zoltan , Juhasz Viktoria , Janossy Judit , Heredi-Szabo Krisztina , Krajcsi Peter
Published: October 2011

The aim of this chapter is to describe the main in vitro assays used to predict the interaction of drugs
with ABC efflux transporters, to highlight their characteristics and to discuss their advantages and disadvantages.
In recent years, the number of synthesized compounds has increased dramatically as a result of advances in
combinatorial chemistry; consequently, early prediction of the interactions of drug-like compounds with efflux
transporters has garnered considerable attention. Moreover, transporter-related drug-drug interactions,
particularly in specific groups (children and the elderly), are of great concern. The withdrawal of marketed drugs
and the failure of drugs in the late clinical phase of drug research is often due to drug-drug interactions.
Furthermore, regulatory authorities require information on the potential for interactions to cause adverse effects: a
question that might be answered by in vitro assays even in the early stages of discovery. In vivo studies and cellbased
assays such as CaCo-2 monolayers have been elaborated, as well as quite expensive screening modes that
are primarily used for screening large numbers of compounds. By scaling the discussed in vitro assays up to
medium- or high-throughput screening modes, these assays can be efficiently used for the prediction of active
transport and transporter-mediated drug-drug interactions, and may be the most cost-effective approach to
transporter screening in drug discovery.
Cell-Penetrating Peptides and Protein Transduction Domains in Drug Delivery
Authors: Duda Erno , Letoha Tamas
Published: October 2011

High molecular weight biomolecules are becoming increasingly important for the development of
molecular therapies. However, these molecules cannot diffuse through the cell membrane the way traditional
small molecule drugs can. The potential therapeutic use of such information-rich macromolecules has been
limited by their poor permeability across the lipid bilayer of biological membranes. Different approaches have
been used to develop biological agents, biophysical methods or mimicking natural processes to overcome the
barrier function of the plasma membrane. The unique capability of special oligopeptides, known as cellpenetrating
peptides (CPPs) or protein transduction domains (PTDs), opened the way to introducing biologically
active macromolecules into living cells. These peptides, conjugated or complexed with the desired molecules, can
be used in both in vitro and in vivo systems for the intracellular or intraorganellar delivery of large molecules.
After the discovery of these small peptides, macromolecular transport across biological membranes has emerged
as a valuable technique in basic research and a promising tool in in vivo preclinical models and clinical trials.
This chapter attempts to give an overview of what kind of CPPs exist, how they function, what has been achieved
and what can be achieved in the future with their use. It also aims to expose the limitations of the utilization of
CPPs and the controversies regarding their potential, working mechanism and route of internalization. Finally, we
want to discuss how virus-, liposome- and CPP-mediated techniques converge into new complex methodologies.
Multilingual Elite-interviews and Software-based Analysis
Authors: Sinkovics Rudolf R. , Penz Elfriede
Published: October 2011

Qualitative international research is increasingly popular in marketing, management and business practice. Cultural dimensions, most importantly language, play a central role in this research context. The importance of language in the context of questionnaire design and international data gathering has long been stressed in various sources (Pike 1966; Brislin 1970; Piekkari & Welch 2004). However, the practice of qualitative data collection and analysis has not been addressed sufficiently, although new and innovative software-based tools are available to help these efforts. This paper deals with methodological and practical issues in analysing qualitative interviews with corporate elites. We illustrate conceptual challenges in setting up qualitative projects that build on interviewing corporate elites and address practical implementation issues in terms of multilingual coding, node creation and theory building by means of computerassisted qualitative data analysis software (CAQDAS). To this end a specific empirical example will be used.
Identification of Average Treatment Effects in Social Experiments Under Alternative Forms of Attrition
Authors: Huber Martin
Published: October 2011

As any empirical method used for causal analysis, social experiments are prone to attrition which may flaw the validity of the results. This article considers the problem of partially missing outcomes in experiments. First, it systematically reveals under which forms of attrition—in terms of its relation to observable and/or unobservable factors—experiments do (not) yield causal parameters. Second, it shows how the various forms of attrition can be controlled for by different methods of inverse probability weighting (IPW) that are tailored to the specific missing data problem at hand. In particular, it discusses IPW methods that incorporate instrumental variables (IVs) when attrition is related to unobservables, which has been widely ignored in the experimental literature before.
Hepatoprotective Action of Radix Paeoniae Rubra Aqueous Extract against CCl4-Induced Hepatic Damage
Authors: Li Ruidong , Guo Wenyuan , Fu Zhiren , Ding Guoshan , Zou You , Wang Zhengxin
Published: October 2011

In the present study the capacity of Radix Paeoniae Rubra aqueous extract (RPRAE) as an antioxidant to protect against carbon tetrachloride (CCl4)-induced oxidative stress and hepatotoxicity in Wistar rats was investigated. Six groups of rats were used. Radix Paeoniae Rubra aqueous extract (100 or 200 or 300 mg/kg of bw) or bifendate (100 mg/kg of bw) were given daily by gavage to the animals on 28 consecutive days to elucidate the protective effects against CCl4-induced hepatotoxicity. The 20% CCl4/olive oil was gavage of gastric tube twice a week (on the third and seventh days of each week). The animals of normal control group were given only vehicle. The animals of CCl4-treated group were administered with CCl4 twice a week (on the third and seventh days of each week) and with vehicle on rest of the days. The test materials were found effective as hepatoprotective agents, as evidenced by plasma and liver biochemical parameters. Therefore, the results of this study show that Radix Paeoniae Rubra aqueous extract can protect the liver against CCl4-induced oxidative damage in rats, and the hepatoprotective effects might be correlated with its antioxidant and free radical scavenger effects.
Interaction of spin and vibrations in transport through single-molecule magnets
Authors: May Falk , Wegewijs Maarten R , Hofstetter Walter
Published: October 2011

We study electron transport through a single-molecule magnet (SMM) and the interplay of its anisotropic spin with quantized vibrational distortions of the molecule. Based on numerical renormalization group calculations we show that, despite the longitudinal anisotropy barrier and small transverse anisotropy, vibrational fluctuations can induce quantum spin-tunneling (QST) and a QST-Kondo effect. The interplay of spin scattering, QST and molecular vibrations can strongly enhance the Kondo effect and induce an anomalous magnetic field dependence of vibrational Kondo side-bands.
Are Gerontological Nurses Apathetic About Apathy in Older Adults
Authors: Lane Annette M. , Hirst Sandra P.
Published: October 2011

Despite its serious health consequences, apathy in older adults is often underrecognized by gerontological nurses and other health care professionals. Within this article, we discuss what apathy is and present a review of the literature and research. Two frameworks emerging from the literature search—one regarding rehabilitation and the other illness—are introduced as ways in which apathy may be conceptualized and addressed. Using these frameworks, implications for gerontological nurses are outlined.
Garden Walking and Art Therapy for Depression in Older Adults: A Pilot Study
Authors: McCaffrey Ruth , Liehr Patricia , Gregersen Thomas , Nishioka Reiko
Published: October 2011

The purpose of this pilot study was to compare garden walking (either alone or guided) with art therapy in older adults with depression. Depression was measured using the Geriatric Depression Scale (GDS) and stories of sadness/joy. Prior to the intervention, 47% of participants had depression scores in the severe range and 53% in the mild range. At the end of the intervention, none of the participants had scores in the severe range, 89% had scores in the mild range, and 11% had scores in the normal range. Results of the GDS data using repeated measures analysis of variance indicated significant decreases in depression for all three groups from pretest to posttest. All participants, regardless of group assignment, had a lower percentage of negative-emotion word use and a higher percentage of positive-emotion word use over time. This study provides evidence for nurses wishing to guide older adults in safe, easy, and inexpensive ways to reduce depression.
Hacia el desarrollo sostenible. Evolución y tendencias de la política europea de medio ambiente
Authors: Aguilar Fernández Susana
Published: October 2011

En este artículo se analiza la evolución de la política medioambiental de la Unión Europea, desde sus antecedentes a mediados de los años 70 hasta su desarrollo y posterior consolidación a raíz del Acta Única (1986), primero, y del Tratado de Maastricht (1992), más tarde. En primer lugar, el autor presenta algunas de las perspectivas teóricas que pueden ser de utilidad para analizar el desarrollo de las políticas públicas, centrándose sobre todo en el neoinstitucionalismo y la teoría de la gobernanza. En segundo lugar, se analizan las características más relevantes de la política medioambiental europea, mostrando su naturaleza regulativa y cómo ha incorporado instrumentos económico-fiscales, basados en la voluntariedad y negociación con los grupos implicados, y en la información y educación de los ciudadanos y agentes sociales. Finalmente, el artículo expone las claves del éxito de la estrategia de desarrollo sostenible en la UE.
Inmigrantes peruanas en España. Conquistando el espacio laboral extradoméstico
Authors: Escrivá Chordá Angeles
Published: October 2011

La sustitución de mujeres inmigrantes de unas nacionalidades por otras es un fenómeno bastante frecuente en el ámbito de la inmigración. El caso de las peruanas en España lo confirma con claridad. En este artículo se analiza dicho fenómeno social explicando por qué comparativamente las peruanas muestran algo más de movilidad ocupacional que las mujeres de otras nacionalidades que incluso llevan más tiempo en España. El artículo recalca que los nuevos puestos conquistados siguen mostrando mayormente la característica de ser poco cualificados, poco remunerados y considerados, reincidiendo en la asignación de tareas de servicio calificadas de femeninas y poco reconocidas en las mujeres. La reflexión final apunta a que sigue abierto el debate sobre la consideración social del trabajo doméstico, el reparto de estas tareas entre los géneros, y la necesaria conciliación del hogar con el empleo remunerado.
La migración laboral Marroqui y los territorios españoles de Ceuta y Melilla
Authors: White Gregory
Published: October 2011

Los enclaves españoles de Ceuta y Melilla desempeñan un papel central en la política de migración transmediterránea. Asimismo, resultan cruciales para la economía del norte de Marruecos debido al movimiento de personas y bienes que se produce hacia aquellas zonas libres de impuestos. Además, Ceuta y Melilia se encuentran en el centro de una enconada disputa diplomática entre España y Marruecos, en la que Rabat cuestiona la soberanía de España sobre dichos territorios. Sin embargo, la soberanía de cada uno de los enclaves se ha visto reforzada, no socavada, por el sistema de migración laboral en el que se hallan inmersos. Pese a las quejas y a la insatisfacción de las que, en ocasiones, Rabat da muestras, lo más probable es que esos territorios sigan siendo españoles. Por su parte, Marruecos se beneficiará de esa carta en sus negociaciones con España y la UE.
Cambio familiar y maltrato conyugal a la mujer
Authors: Meil Landwerlin Gerardo
Published: October 2011

Según la teoría de los recursos, la ganancia de recursos de poder por parte de las mujeres derivada de las distintas dimensiones del cambio familiar (desintitucionalización de la familia, incorporación de la mujer al mercado de trabajo, mayor nivel educativo, etc.) ha comportado un mayor poder de negociación del contenido de los roles familiares y domésticos. Esta ganancia en recursos de poder debería haberse traducido en una menor violencia conyugal contra las mujeres que viven en uniones “modernas”. A partir de la macroencuesta sobre violencia de género realizada por el Instituto de la Mujer en 1999 se analiza si las distintas dimensiones del cambio familiar están asociadas con un menor riesgo de maltrato. Los resultados obtenidos mediante ajustes de regresión logística indican que el cambio familiar y el correspondiente aumento de poder de negociación de las mujeres no se ha traducido automáticamente en una reducción del riesgo de maltrato.
Distintas aproximaciones a la elección racional
Authors: Martínez García José Saturnino
Published: October 2011

En este artículo se realiza una clasificación de las teorías de la elección racional. La elección racional instrumentalista dice que la teoría es buena si sus predicciones teóricas son buenas, sin importar si la teoría es cierta o falsa. La elección racional realista considera que la teoría de la elección racional es cierta, pero que necesita de otros supuestos, tomados normalmente de la psicología, como la teoría cognitivista. La reconstrucción racional de la acción, enmarcada en la tradición weberiana, considera la elección racional como una forma de comprender la acción social mediante empatía, atribuyéndole sentido. La reconstrucción formal afirma que la elección racional no es realmente una teoría, sino simplemente una gramática útil para pensar los problemas sociales. La reconstrucción estadística defiende que la elección racional es buena para explicar un tipo ideal de actor, representativo de un conjunto: cada actor puede ser diferente, pero las restricciones institucionales producen regularidades empíricas para el conjunto.
Las paradojas de la globalización
Authors: Larochelle Gilbert
Published: October 2011

El debate contemporáneo sobre la globalización (mundialización) se ve restringido por unos modos de aproximación que limitan su análisis e impiden dilucidar sus elementos fundamentales. En el debate se observan varias actitudes: desde quienes lo demonizan hasta quienes lo ensalzan; desde los que lo interpretan en términos del bien o del mal hasta los que caen en la tentación de contrarrestarlo replegándose en la intimidad deliberativa de la comunidad. Más allá de las posibles reacciones a este fenómeno, en el fondo del debate subyace una antinomia, más tenaz y decisiva que cualquier otra, enfrentando democracia y globalización. El objetivo de este artículo es negar tal enfrentamiento, mostrando la porosidad de las dinámicas locales y globales. Asimismo, muestra cómo el proceso de globalización activa la concurrencia entre los sistemas sociales haciendo posible nuevas opciones de vida y debilitando la capacidad de las élites para ejercer un dominio pleno sobre la sociedad. Este artículo analiza de manera crítica los tres elementos fundamentales del debate, a saber: la selección de las palabras utilizadas para describir la globalización; los argumentos que delimitan el escenario del debate, y sus efectos sobre el ejercicio de la libertad en las sociedades democráticas.
La situación residencial de la población inmigrante en Andalucía
Authors: Rinken Sebastin , Herrón Anaïs
Published: October 2011

En este artículo se describe la situación residencial en Andalucía de los inmigrantes procedentes de países menos desarrollados. Basándonos en datos de una reciente encuesta representativa, llevamos a cabo un examen pormenorizado de las situaciones de ausencia de vivienda digna en esta población, haciendo especial hincapié en establecer definiciones claras e indicadores transparentes. Los resultados confirman la existencia de una situación residencial gravemente deficiente de una proporción importante de los inmigrantes asentados en zonas de agricultura intensiva, sobre todo en la provincia de Almería. Sin embargo, a diferencia de otros estudios, concluimos que aproximadamente cuatro de cada cinco inmigrantes asentados en Andalucía disponen de una vivienda digna.