bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal tolerance of crustacean larvae (zoea I) in two different populations of the kelp crabTaliepus dentatus(Milne-Edwards)
Authors: Storch Daniela , Santelices Pedro , Barria Jessica , Cabeza Karla , Pörtner Hans-Otto , Fernández Miriam
Published: April 2009

Studies of thermal tolerance in marine ectotherms are key in understanding climate effects on ecosystems; however, tolerance of their larval stages has rarely been analyzed. Larval stages are expected to be particularly sensitive. Thermal stress may affect their potential for dispersal and zoogeographical distribution. A mismatch between oxygen demand and the limited capacity of oxygen supply to tissues has been hypothesized to be the first mechanism restricting survival at thermal extremes. Therefore, thermal tolerance of stage zoea I larvae was examined in two populations of the Chilean kelp crab Taliepus dentatus, which are separated by latitude and the thermal regime. We measured temperature-dependent activity, oxygen consumption,cardiac performance, body mass and the carbon (C) and nitrogen (N) composition in order to: (1) examine thermal effects from organismal to cellular levels,and (2) compare the thermal tolerance of larvae from two environmental temperature regimes. We found that larval performance is affected at thermal extremes indicated by decreases in activity, mainly in maxilliped beat rates,followed by decreases in oxygen consumption rates. Cardiac stroke volume was almost temperature-independent. Through changes in heart rate, cardiac output supported oxygen demand within the thermal window whereas at low and high temperature extremes heart rate declined. The comparison between southern and central populations suggests the adaptation of southern larvae to a colder temperature regime, with higher cardiac outputs due to increased cardiac stroke volumes, larger body sizes but similar body composition as indicated by similar C:N ratios. This limited but clear differentiation of thermal windows between populations allows the species to widen its biogeographical range.
Determination of Binding Parameters and Mode of Ferrocenyl Chalcone–DNA Interaction
Authors: Shah Afzal , Qureshi Rumana , Khan Asad Muhammad , Ansari Farzana Latif , Ahmad Safeer
Published: April 2009

This paper reports that how the variation in peak current, absorbance, and viscosity of ferrocenyl chalcone (FC), chemically named as 1-ferrocenyl-3-(4-nitrophenyl)-2-propen-1-one, in 10% aqueous DMF upon addition of DNA can be used to probe the mode of interaction and binding parameters. Binding constant (K = 5.17 (±0.25) × 103 M−1), binding site size (s = 1.08 ± 0.05 bp) and diffusion coefficient of the free (Df = 5.22 × 10−7 cm2 s−1) and DNA bound drug (Db = 4.39 × 10−8 cm2 s−1) were determined from voltammetric data. The binding constant (K = 4.91 (±0.20) × 103 M−1) was also obtained from UV–vis absorption titration. Gibbs energy change (ΔG = −RT ln K) of −21.18 kJ mol−1 at 25 °C indicated the spontaneity of the binding interaction. The experimental results revealed intercalation of FC into DNA as the dominant mode of interaction. Furthermore, the radii of the free and DNA-bound drug were determined from viscosity measurements.
Formation and Decay Dynamics of Vitamin E Radical in the Antioxidant Reaction of Vitamin E
Authors: Mukai Kazuo , Ouchi Aya , Mitarai Akiko , Ohara Keishi , Matsuoka Chihiro
Published: April 2009

In order to understand the dynamics of antioxidant actions of vitamin E (α-, β-, γ-, and δ-tocopherols, TocH) in biological systems, kinetic study of the formation and decay reactions of vitamin E radicals (α-, β-, γ-, and δ-tocopheroxyls, Toc•) has been performed in organic solvents, using stopped-flow spectrophotometry. By mixing α-, β-, γ-, and δ-TocH with aryloxyl radical (ArO•) in ethanol, the peaks of the UV–vis absorption due to α-, β-, γ-, and δ-Toc• radical appeared rapidly at ca. 430–340 nm, showed maxima, and then decayed gradually. The second-order rate constants (kf and 2kd) for the formation and decay (that is, bimolecular disproportionation) reactions of α-Toc• were determined by comparing the observed curves with the simulation ones obtained by the numerical calculation of differential equations related to the above reactions. From the results, the wavelengths of absorption maxima (λmaxi) and molar extinction coefficients (εi) (i = 1–4) of the optical spectra were determined for α-Toc• radical. Notable solvent effects have been observed for the reaction rates (kf and 2kd) and absorption spectra (λmaxi and εi) of α-Toc• radical. The scheme of the formation and decay reactions of α-, β-, γ-, and δ-Toc• radicals has been discussed based on the results obtained.
Sensitization of NaMO3 (M: Nb and Ta) Photocatalysts with Wide Band Gaps to Visible Light by Ir Doping
Authors: Iwase Akihide , Saito Kenji , Kudo Akihiko
Published: April 2009

NiO/NaNbO3 (BG: 3.5 eV) showed photocatalytic activity for water splitting into H2 and O2 under UV irradiation. When NaMO3 (M: Nb and Ta) was codoped with iridium ions and alkaline earth metal ions or lanthanum ions, a new visible-light absorption band was observed in addition to the band gap absorption band of the host material. The codopants of alkaline earth metal and lanthanum ions contributed to maintaining the charge balance and forming of fine crystals of the NaMO3 powder. These NaNbO3 and NaTaO3 codoped with iridium ions and alkaline earth metal ions or lanthanum ions showed photocatalytic activities for H2 or O2 evolution from an aqueous solution containing a sacrificial reagent under visible light irradiation.
Pressure Dependence of Aggregation State of (DMPC/Cholesterol) Mixed Monolayer Based on AFM Observation
Authors: Tagami Yasunobu , Matsufuji Takashi , Ikigai Hajime , Narita Takayuki , Oishi Yushi
Published: April 2009

We investigated the aggregation state of a mixed monolayer of 1,2-dimyristoyl-sn-glycero-3-phospholine and cholesterol at different surface pressures by AFM. AFM images revealed a nanoscopically separated structure despite a macroscopic homogenization of the monolayer under compression.
Electronegative Oligothiophenes Having Difluorodioxocyclopentene-annelated Thiophenes as Solution-processable n-Type OFET Materials
Authors: Ie Yutaka , Okabe Makoto , Umemoto Yoshikazu , Tada Hirokazu , Aso Yoshio
Published: April 2009

Solution-processable electronegative oligothiophenes bearing difluorodioxocyclopentene-annelated thiophenes have been synthesized. The electronic properties of the oligomers were investigated by absorption spectroscopy and electrochemical measurements. Their films fabricated by spin-coating showed typical n-channel OFET behavior.
Electrochemical Sensing of Sulfate Using Mixed Thiol-derivatized β-Cyclodextrin/Pentanethiol Monolayers
Authors: Domi Yasuhiro , Shimazu Katsuaki , Porter Marc D
Published: April 2009

The oxidation of ferrocene on a defect-free mixed per-6-thio-β-cyclodextrin/pentanethiol monolayer in a NaClO4 solution was inhibited in the presence of sulfate. The peak current in differential pulse voltammograms linearly decreased with the logarithm of the sulfate concentration in an extremely wide range from 1 nM to 1 mM, showing the possible application as an electrochemical sensor of sulfate.
Simple Determination of Melamine Based on Self-assembly of Citrate-capped Gold Nanoparticles
Authors: Qin Zhu Hong , Zhao Hua Wen , Huang Cheng Zhi , Wu Li Ping
Published: April 2009

In the presence of melamine (2,4,6-triamino-s-triazine), citrate-capped gold nanoparticles (Au-NPs) can self-assemble and form a network structure through electrostatic interactions. A new absorption peak appears at approximately 700 nm, and the intensity is proportional to the concentration of melamine. Thus, a new simple method of detecting melamine is developed.
Supervised training with wireless monitoring of ECG, blood pressure and oxygen-saturation in cardiac patients
Authors: Busch Clemens , Baumbach Christian , Willemsen Detlev , Nee Oliver , Gorath Torsten , Hein Andreas , Scheffold Thomas
Published: April 2009

We have developed a tele-rehabilitation application for training cardiac patients. It uses a modified ergometer bicycle with a set of wireless sensors. While the patient is exercising, the ECG, blood pressure and oxygen-saturation are monitored constantly and automatically. If sensor values exceed pre-defined thresholds, the patient receives an alarm. As a result the training will either be stopped or continued at a reduced load, depending on the severity of the alarm. To measure user acceptance, we introduced the system to 13 members of staff and four patients, who trained on the system every day during their stay in hospital. A total of 39 training sessions were completed. In 27% of the exercise sessions an ECG connection could not be established and in 23%, blood pressure measurement failed. However, there were no failures to measure oxygen saturation. The overall acceptance of the patient's graphical user interface (GUI) was excellent. The doctor's GUI with its functions received an overall score of 1.5 on a scale of 1 to 4 (usefulness 1.6, usability 1.3 and operability 1.6). The SAPHIRE tele-rehabilitation system operated properly and was well accepted by patients and doctors.
A randomized trial of virtual visits in a general medicine practice
Authors: Dixon Ronald F , Stahl James E
Published: April 2009

We compared desktop videoconferencing to conventional face-to-face visits for a range of commonly presenting problems in a general practice. A total of 175 patients were recruited. Patients were randomized to one of two arms of the study. In the first arm, the patients completed a visit (virtual or face-to-face) with a physician; they then completed a second visit via the other modality with another physician. In the second arm of the study, subjects had both visits face-to-face; different physicians conducted the two face-to-face consultations. Patients found virtual visits similar to face-to-face visits on most measures, including time spent with the physician, ease of interaction and personal aspects of the interaction. Physicians were also highly satisfied with the virtual visit modality. The diagnostic agreement between physicians was 84% between face-to-face and virtual visits; it was 80% between the two face-to-face visits. The study suggests that both patients and physicians could benefit if virtual visits were used as an alternative method of accessing primary care services.
Head and neck cancer assessment by flexible endoscopy and telemedicine
Authors: Dorrian Cathy , Ferguson Jim , Ah-See Kim , Barr Catriona , Lalla Kushik , van der Pol Marjon , McKenzie Lynda , Wootton Richard
Published: April 2009

We have conducted a feasibility study to establish whether ENT tele-endoscopy would be a suitable method of service delivery for patients who live in the Shetland Islands. Ten clinics were conducted over a period of 17 months using ISDN-based videoconferencing at a bandwidth of 384 kbit/s. A total of 42 patients were seen in Aberdeen via videoconferencing for a head and neck cancer assessment. Feasibility was confirmed after the first 20 patients, following positive feedback from all concerned and the absence of any significant clinical or technical problems. A total of 42 journeys was avoided, each journey saving 123 kg CO2 per person. A preliminary cost analysis showed that the threshold at which tele-ENT became cheaper than travel was a workload of 35 patients/year. The actual workload during the pilot study was 29 patients/year. A national telemedicine service for the initial assessment of potential malignancy has the potential to reduce unnecessary transfers to specialist centres, with accompanying reductions in carbon emissions.
Remote probe microphone measurement to verify hearing aid performance
Authors: Ferrari Deborah Viviane , Bernardez-Braga Gabriela Rosito Alvarez
Published: April 2009

We assessed the feasibility of obtaining probe microphone measurements of hearing aids at a distance. Face-to-face and remote probe microphone measurements were carried out in 60 hearing aid users (mean age 67 yrs) with uni- or bilateral hearing losses (105 ears tested). The participant and a facilitator were located in a room equipped with a probe microphone system interfaced to a PC. Desktop videoconferencing and application sharing was used to allow an audiologist in another room to instruct the facilitator and control the equipment via the LAN. There were significant correlations between face-to-face and remote real ear unaided response (REUR), aided response (REAR) and insertion gain (REIG) at seven discrete frequencies from 250 to 6000 Hz. Differences between face-to-face and remote responses were within the reported variability for probe microphone measurements themselves. The results show that remote probe microphone measurements are feasible and might improve the quality of public hearing aid services and professional training in Brazil.
Evaluation of a mobile phone telemonitoring system for glycaemic control in patients with diabetes
Authors: Istepanian Robert SH , Zitouni Karima , Harry Diane , Moutosammy Niva , Sungoor Ala , Tang Bee , Earle Kenneth A
Published: April 2009

We conducted a randomized controlled trial using mobile health technology in an ethnically diverse sample of 137 patients with complicated diabetes. Patients in the intervention group ( n = 72) were trained to measure their blood glucose with a sensor which transmitted the readings to a mobile phone via a Bluetooth wireless link. Clinicians were then able to examine and respond to the readings which were viewed with a web-based application. Patients in the control arm of the study ( n = 65) did not transmit their readings and received care with their usual doctor in the outpatient and/or primary care setting. The mean follow-up period was 9 months in each group. The default rate was higher in the patients in the intervention arm due to technical problems. In an intention-to-treat analysis there were no differences in HbA1c between the intervention and control groups. In a sub-group analysis of the patients who completed the study, the telemonitoring group had a lower HbA1c than those in the control group: 7.76% and 8.40%, respectively ( P = 0.06).
An economic analysis of the national shared emergency care summary in Scotland
Authors: Jones Tom , Dobrev Alexander , Cameron Jonathan , Morris Libby , Stroetmann Karl A , Stroetmann Veli N
Published: April 2009

The Emergency Care Summary (ECS) in Scotland provides essential clinical and demographic information about patients needing unscheduled or emergency care. Information about patients’ medications, adverse drug reactions and allergies is transferred twice every day from GP systems to the ECS. Access is then available to authorised health-care professionals at the national help line, at out-of-hours services and in accident and emergency departments. An economic analysis of the ECS implementation showed that annual benefits exceeded annual costs after about seven years. Approximately 77% of the benefits were non-financial and 23% from redeployed finance. No cash savings were planned and none were realised. As ECS utilisation increased from 2006, the net benefits became positive. This relationship between utilisation and net benefits is a common feature of successful e-health investment.
Stroke networks based on robotic telepresence
Authors: Lai Fuji
Published: April 2009

In the USA, several telestroke networks have been successfully implemented in which a stroke centre of excellence provides expertise to community and rural hospitals via telemedicine. Stroke patients can thus receive round-the-clock access to stroke expertise. The Remote Presence (RP) system is used in several of these telestroke networks. The stroke expert uses a laptop and wireless Internet to connect to the RP robot in the peripheral emergency department. This improves the geographical reach of stroke specialist care, and improves patient outcomes as well as conforming with best practice. The stroke network concept combined with telemedicine is a powerful way of transforming stroke care.
The Swansea electronic referrals project
Authors: Scott Karla
Published: April 2009

A system was developed to allow general practitioners in Swansea to send urgent cancer referrals electronically to consultants at the South West Wales Cancer Centre. Five practices from the Swansea area took part in a pilot trial. Information was extracted from the system to evaluate the e-referral activity of the first six months, during which a total of 99 referrals were submitted electronically; most (81%) were processed within one hour. Evaluation interviews were conducted with staff at the general practices, who were asked to rate the system on a 10-point Likert scale (1 = completely dissatisfied to 10 = completely satisfied); the lowest satisfaction rating given by the practices was 8. The staff agreed that the use of a standard form was beneficial and improved the quality of the referral information submitted to consultants.
Public health education for young students aided by technology
Authors: Macea Debora D , Rondon Silmara , Chaar Laiali J , Wen Chao L
Published: April 2009

Brazil is a large country with a population of nearly 200 million people. There are difficulties in providing public health education. To ensure its effectiveness, health education should begin during adolescence, to encourage young people to adopt healthy habits. A web-based tele-education platform was developed. Thirty students from a public high school in the rural city of Tatui took part in a pilot trial. Six teachers coordinated the student's activities. After face-to-face training, the students participated in tele-education, using a ‘cybertutor’ (an educational environment based on the website) and discussion lists. There were 15 face-to-face interactions, followed by more than 200 offline and 50 online interactions. The students learned about seven health topics. During the following year, 20 of the students used their knowledge to teach people from their local communities. We estimate that about 3000 people, including children, adults and the elderly, received public health education during events in Tatui and in their schools. The pilot trial showed that face-to-face and distance interventions in the rural city of Tatui were a feasible method of disseminating public health information.
Test of a brief theory of planned behaviour‐based intervention to promote adolescent safe sex intentions
Authors: Armitage Christopher J. , Talibudeen Luke
Published: April 2009

The present study tested a brief (303 word) intervention designed to change attitude, subjective norm, and perceived behavioural control regarding a safe sex behaviour in a sample of 16‐ to 18‐year‐olds. Participants (N = 288) were randomized to receive either an experimental intervention or a control (knowledge only) intervention and completed measures of their reactions to the stimuli as well as pre‐ and post‐test measures of theory of planned behaviour variables. The experimental intervention significantly increased message processing (mean between‐group difference = 0.73, 95% CI = 0.40, 1.06; Cohen's d = .52), message acceptance (mean between‐group difference = 0.82, 95% CI = 0.57, 1.07; Cohen's d = .77), subjective norm (adjusted Mean between‐group difference = 0.54, 95% CI = 0.26, 0.81; Cohen's d = .37; mean within‐group difference for intervention condition = 0.59, 95% CI = 0.36, 0.81; Cohen's d = .38) and intention (adjusted Mean between‐group difference = 0.27, 95% CI = 0.02, 0.53; Cohen's d = .20; mean within‐group difference for intervention condition = 0.54, 95% CI = 0.33, 0.75; Cohen's d = .31), but not attitude or perceived behavioural control. The effects of the experimental intervention on intention were mediated solely through subjective norm. The present findings: (a) compare favourably in terms of the effect sizes reported in previous research in this area (mean Cohen's d for within‐group difference for intervention conditions = .009 and .09, for norms and intention, respectively, see Albarracín et al. (2003)), (b) imply that subjective norms are causally related to intentions, and (c) suggest that interventions designed to change subjective norms (as opposed to communication of risks and fear appeals) might ultimately be effective in changing behaviour.
‘It's a boy because he's painting a picture’: Age differences in children's conventional and unconventional gender schemas
Authors: Tenenbaum Harriet R. , Hill Darryl B. , Joseph Nadia , Roche Erin
Published: April 2009

Two studies investigated the development of children's gender knowledge using a procedure designed to tap into children's unconventional gender beliefs. Study 1 revealed a developmental progression with 34 3‐ to 4‐year‐old children providing more unconventional reasons than conventional reasons to explain the gender of a series of drawings. By contrast, 39 5‐ to 6‐year‐old and 42 7‐ to 8‐year‐old children provided more conventional than unconventional reasons. Study 2 found that a second sample of 42 3‐ to 4‐year‐old children mastered a close‐ended assessment of gender stereotyping, while they relied on unconventional and conventional reasoning equally when explaining the gender of a series of drawings displaying conventional cues only. This research supports the model that children's conventional gender schemas do not develop before their unconventional gender schemas.
The use of personality test norms in work settings: Effects of sample size and relevance
Authors: Tett Robert P. , Fitzke Jenna R. , Wadlington Patrick L. , Davies Scott A. , Anderson Michael G. , Foster Jeff
Published: April 2009

The value of personality test norms for use in work settings depends on norm sample size (N) and relevance, yet research on these criteria is scant and corresponding standards are vague. Using basic statistical principles and Hogan Personality Inventory (HPI) data from 5 sales and 4 trucking samples (N range=394–6,200), we show that (a) N>100 has little practical impact on the reliability of norm‐based standard scores (max=±10 percentile points in 99% of samples) and (b) personality profiles vary more from using different norm samples, between as well as within job families. Averaging across scales, T‐scores based on sales versus trucking norms differed by 7.3 points, whereas maximum differences averaged 7.4 and 7.5 points within the sets of sales and trucking norms, respectively, corresponding in each case to approximately ±14 percentile points. Slightly weaker results obtained using nine additional samples from clerical, managerial, and financial job families, and regression analysis applied to the 18 samples revealed demographic effects on four scale means independently of job family. Personality test developers are urged to build norms for more diverse populations, and test users, to develop local norms to promote more meaningful interpretations of personality test scores.
Buchbesprechung/Book Review
Authors: Walzel Dr. rer. nat. H.
Published: April 2009

No abstract available
Buchbesprechung/Book review
Authors: Klein Dr. med. Hans-Georg
Published: April 2009

No abstract available
The Potential Use of Electricity to Control Burrowing Shrimp in Oyster Aquaculture Beds
Authors: Dumbauld Brett , Harlan Lisa
Published: April 2009

Thalassinidean shrimp cause significant problems for oyster aquaculture in the Pacific Northwest (USA), where oysters succumb to the physical sediment disruption generated by the burrowing activity of these animals. Although electrofishing is a commonly used technique to capture fish and some invertebrates in freshwater, applications in marine systems are limited due to the high conductivity of the water medium. Experiments conducted in aquaria showed that burrowing bay ghost shrimp Neotrypaea californiensis responded best (forced swimming with directed movement) to a pulsed DC waveform with optimal parameter settings of 1 V/cm, a frequency of 2 Hz, and a pulse width of 0.001–0.005 s. Unfortunately, when bay ghost shrimp were allowed to burrow into the substrate, they displayed a similar reaction but moved towards the bottom of their burrows, thus ruling out the envisioned use of this technique to attract them to the surface for capture. In experiments designed to induce mortality, it was possible to achieve paralysis or tetany by use of higher power with DC, pulsed DC, and AC, but the animals recovered unless (1) exposure time exceeded 60–100 s and (2) voltage exceeded 100 V (5 V/cm), frequency exceeded 120 Hz (pulsed DC), or both. These sustained levels would be difficult to achieve in the field due to the substrate, depth of the shrimp burrows, and high power necessary to obtain adequate field strength.
Determinantes sociais da iniciação sexual precoce na coorte de nascimentos de 1982 a 2004-5, Pelotas, RS
Authors: Gonçalves Helen , Béhague Dominique P , Gigante Denise P , Minten Gicele C , Horta Bernardo L , Victora Cesar G , Barros Fernando C
Published: April 2009

OBJETIVO: Analisar determinantes sociais da iniciação sexual precoce de jovens pertencentes a uma coorte de nascimentos. MÉTODOS: Foram entrevistados em 2004-5 os indivíduos da coorte de nascimentos de Pelotas (RS), em 1982 (N=4.297). A iniciação sexual precoce (<13 anos) foi o desfecho. Análises descritivas e estratificadas foram realizadas segundo o sexo. As variáveis analisadas foram renda familiar em 1982, cor da pele, escolaridade do jovem e mudança de renda (1982-2004-5). Usaram-se dados etnográficos para complementar a análise dos resultados. RESULTADOS: A prevalência de iniciação sexual precoce foi maior para homens com cor da pele preta/parda, baixa escolaridade, renda familiar baixa em 1982 e em 2004-5. As exigências para que os papéis sexuais masculinos mais tradicionais (virilidade, iniciativa sexual) mostraram ter maior repercussão e adesão desde cedo no grupo dos homens. Jovens mulheres de família com maior renda e de maior escolaridade tenderam a postergar a iniciação sexual. Os reflexos da imposição de valores culturais tradicionais mostraram-se importantes para a iniciação sexual precoce em homens e mulheres, ambos com menor escolaridade e renda. CONCLUSÕES: Os resultados encontrados recolocam o fator econômico como determinante dos comportamentos ou dos usos da sexualidade para ambos os sexos. Concentrar esforços políticos que incentivem a população menos privilegiada economicamente a ter chances e perspectivas futuras igualitárias é uma estratégia importante para desfechos em saúde.
Maternidade e paternidade na coorte de nascimentos de 1982 a 2004-5, Pelotas, RS
Authors: Gigante Denise P , Barros Fernando C , Veleda Rosângela , Gonçalves Helen , Horta Bernardo L , Victora Cesar G
Published: April 2009

OBJETIVO: Descrever a prevalência de maternidade e paternidade em adultos jovens e sua associação com variáveis perinatais, socioeconômicas e demográficas. MÉTODOS: Os participantes foram jovens com idade média de 23 anos, acompanhados em estudo de coorte desde o seu nascimento, em 1982, em Pelotas (RS) e entrevistados em 2004-5. Foram considerados elegíveis os jovens que referiram ter tido um ou mais filhos, nascidos vivos ou mortos. Dois questionários foram aplicados para coletar informações sobre saúde reprodutiva, dados socioeconômicos e demográficos. As variáveis independentes foram sexo e cor da pele, renda familiar em 1982 e 2004-5, mudança de renda, peso ao nascer do jovem e escolaridade aos 23 anos. Análises brutas e ajustadas foram realizadas por meio de regressão de Poisson para investigar os efeitos das variáveis independentes sobre a maternidade/paternidade na adolescência. RESULTADOS: De 4.297 jovens entrevistados, 1.373 (32%) eram mães ou pais, dos quais 842 (19,6%) haviam experimentado a maternidade/paternidade na adolescência. O planejamento da gravidez do primeiro filho mostrou relação direta com a idade do jovem. Relação inversa foi observada entre as variáveis socioeconômicas e a ocorrência de maternidade/paternidade na adolescência. A probabilidade de ser mãe na adolescência foi maior entre as mulheres pretas ou pardas, mas a cor da pele não esteve associada com a paternidade na adolescência. CONCLUSÕES: Houve forte relação entre a maternidade/paternidade na adolescência e condições socioeconômicas, a qual deve ser considerada no delineamento de ações preventivas no campo da saúde pública.
Vulnerabilidades e situações de riscos relacionados ao uso de agrotóxicos na fruticultura irrigada
Authors: Bedor Cheila Nataly Galindo , Ramos Lara Oliveira , Pereira Paulo José , Rêgo Marco Antônio Vasconcelos , Pavão Antonio Carlos , Augusto Lia Giraldo da Silva
Published: April 2009

A determinação de situações de riscos na população que faz uso de agrotóxico é complexa. O objetivo desse estudo foi conhecer o contexto social, econômico e cultural e algumas das vulnerabilidades para a saúde relacionadas com o processo produtivo químico dependente da fruticultura do Vale do São Francisco. Questionário semiestruturado foi aplicado a uma amostra aleatória de trabalhadores rurais, para obtenção de informações socioeconômicas e culturais, assim como a morbidade relacionada com intoxicação por agrotóxicos. Os trabalhadores rurais da região têm em sua maioria baixo grau de escolaridade, sendo esta uma importante vulnerabilidade para compreensão da rotulagem dos agrotóxicos e sua implicação toxicológica e ambiental. Foi observado uso indiscriminado de agrotóxicos em condições inseguras de trabalho que comprometem a saúde dos expostos. A sintomatologia sugestiva de intoxicação por agrotóxicos aponta para quadros relacionados com exposição à organofosforados, carbamatos e piretróides, em congruência com os biocidas utilizados na fruticultura. 7% da população estudada referiram ter sofrido pelo menos um caso de intoxicação no decorrer da vida. A assistência técnica relacionada com o manejo de agrotóxicos é precária e não se observaram ações de proteção no âmbito da saúde, do trabalho, da previdência ou do ambiente. Estas vulnerabilidades institucionais corroboram aquelas relacionadas com o modelo tecnológico que objetiva meramente a produtividade e o rendimento financeiro.
Inferring evolutionary modes in a fossil lineage (Bryozoa:Peronopora) from the Middle and Late Ordovician
Authors: Pachut Joseph F. , Anstey Robert L.
Published: April 2009

Recent analytical advances have permitted quantitative evaluations of evolutionary mode in populations of fossil organisms by providing tests of the null hypothesis that patterns of stratigraphic character variation do not differ from the expectations of a random walk. If the hypothesis can be rejected, then stasis and anagenesis represent alternative evolutionary modes discernable using values of the Hurst estimate. We used this approach to evaluate evolutionary mode in the bryozoan genusPeronoporaacross 34 characters in eight unbranched, cladistically defined, evolutionary sequences. Eight monophyletic crown species and eight paraphyletic (phenetically distinct) metaspecies constitute 16 species-rank taxa within the genus.

In seven of 15 species-rank transitions that had adequate sample sizes, significant character state changes—both phyletic gradualism and punctuated equilibrium—coincided with speciation events 11% of the time and were limited to more derived, crownward, ancestor-descendant pairs. Each of the 34 measured characters exhibited instances of transpecific stasis or anagenesis. Anagenesis of some characters persisted across unbranched lineages over 13 species (i.e., across 12 speciation events), whereas character stasis continued through unbranched lineages in up to 16 species (i.e., persisted unchanged across all 15 speciation events). Transpecific stasis and anagenesis were recognizable in over one-half of the data set, with stasis being approximately twice as common as anagenesis.

Across all character state transitions, approximately one-half reflect stasis, 30% anagenesis, and 20% could not be differentiated from a random walk. Similarly, across species and metaspecies characterized by a single intraspecific mode, stasis was twice as common as anagenesis and three times more common than undifferentiated random walks. The remaining instances of multiple intraspecific evolutionary modes occurred more commonly within metaspecies than within species. This difference might reflect the more frequent presence of unrecognized cryptic species or subspecies within metaspecies ofPeronopora.Instantaneous rates of evolution can be estimated both within and between species ofPeronoporafor characters displaying anagenesis, potentially providing quantitative insights into evolutionary changes within the lineage.
Alpha diversity of Phanerozoic marine communities positively correlates with longevity of genera
Authors: Markov Alexander V.
Published: April 2009

Several lines of theoretical and empirical evidence suggest that there can be a positive correlation between alpha diversity (genus richness) of marine communities (D) and average longevity of marine genera included in these communities (L). One possible reason for such a correlation is that diversity can be expected to give rise to ecosystem stability, which, in turn, may slow down the extinction of taxa. However, this hypothesis has not been verified on the global scale. The analysis of two large data sets (Sepkoski's compendium of fossil marine genera and the Paleobiology Database) shows that the correlation (1) actually exists and (2) is robust to some possible sources of errors in L and D estimation. Further analysis reveals that the correlation is not a secondary pattern caused by any of the following factors: (1) encounter probability of taxa, which is greatly influenced by differential incompleteness of the fossil record; (2) degree of sediment lithification, which is one of the major factors affecting the preservation of fossils; (3) onshore-offshore gradient; (4) parallel growth of both L and D through the Phanerozoic; (5) paleolatitudinal gradient. Although there may be other factors that influence both L and D in a similar way, the results generally confirm the hypothesis that higher alpha diversity enhances longevity of genera.
Taphonomic and zooarchaeological implications of spotted hyena (Crocuta crocuta) bone accumulations in Kenya: a modern behavioral ecological approach
Authors: Lansing Sarah W. , Cooper Susan M. , Boydston Erin E. , Holekamp Kay E.
Published: April 2009

The significant impact of extant carnivores, particularly spotted hyenas, on the depositional history and physical characteristics of archaeofaunal and paleontological assemblages is well recognized. We focus on the behavioral ecology of extant spotted hyenas (Crocuta crocuta) in relation to bone accumulations produced by one East African clan at communal dens. Limbs and skulls of prey animals more frequently appear at dens than do other carcass portions. These items reflect the relative abundance of prey species near dens; carnivore remains are poorly represented. Comparative analysis reveals that bones are deposited far more slowly (<7 carcass portions per month) and accumulations tend to be smaller atCrocutadens than at dens of either brown (Parahyaena brunnea) or striped (Hyaena hyaena) hyenas. We propose that extantCrocutabone accumulation rates and sizes are likely affected by prey species abundance, clan size, social interactions within the clan, and the type and availability of den sites. We also suggest that the potential for intraspecific behavioral variability in bone accumulation patterns is important when comparisons are made among spotted hyena populations and across hyena species. For example, accumulation patterns may be dramatically influenced by the temporal span, potentially ranging from days to hundreds or thousands of years, in which bones are collected, depending on the species-specific history of occupation at a given site. Understanding the behavioral and ecological variability likely to influence bone accumulation patterns at dens used by different hyaenids will allow taphonomists and zooarchaeologists to refine their knowledge of mechanisms underlying site formation processes and potential causes of variability in deeper-time den assemblages.
The effects of rarity and abundance distributions on measurements of local morphological disparity
Authors: Deline Bradley
Published: April 2009

Understanding the relationships between morphological disparity and environment, geography, and scale require examination at the local level. Even with disparity metrics that are inherently sample size independent, the nature of rare species and the segregation of common and rare species within morphospace can create substantial sampling issues. Eight well-sampled, Late Ordovician crinoid assemblages were examined for potential biases in the study of local disparity. Disparity is based on the ordination of discrete characters. The rare and common species within these assemblages contributed equally to disparity. In spite of this pattern, rare species in some localities occupy a different area of morphospace, causing disparity to vary greatly with sampling intensity. Morphological rarefaction based on the number of specimens shows that disparity weighted by abundance is constant past a sample size of approximately 30 individuals. This metric is dependent on the evenness within an assemblage as well as the abundance within subgroups in morphospace. Disparity weighted according to abundance gives a view of the functional disparity of an assemblage, which is more applicable in studies of local disparity, though unweighted disparity is still preferred in regional-scale studies and in investigations of morphospace filling through a clade's history.
A cautionary note on implications of the well-mixed compartment assumption as applied to mass balance models of chemical fate in flowing systems
Authors: Warren Christopher S. , Mackay Donald , Webster Eva , Arnot Jon A.
Published: April 2009

A convenient, simple, and widely used approach for modeling the fate of a chemical in a flowing environmental or biological system is to simulate the system as comprising one or more well-mixed boxes, also known as continuous stirred tank reactors (CSTRs). In principle, any desired level of accuracy can be achieved by increasing the number of boxes. However, highly segmented systems require more input data, they are more computationally intensive, and the results may be more difficult to interpret. Thus there is a tendency to minimize the number of boxes, especially in screening level models. Whereas in the hydrology and engineering literature there is an appreciation of the mathematical errors associated with applying the well-mixed box concept, we believe that these errors are often underappreciated when modeling certain environmental systems. Here, we briefly review the implications of these errors in multimedia models, river and lake simulations, atmospheric transport, flow in soils, gastrointestinal absorption, and metabolism in the liver. The key conclusion is that if over 25% of the chemical entering a box is removed, applying this well-mixed assumption can lead to substantial error. We recommend that results obtained when this criterion is violated be treated with caution.
Verification and Proper Use of Water-Oil Transfer Function for Dual-Porosity and Dual-Permeability Reservoirs
Authors: Balogun A. , Kazemi H. , Ozkan E. , Al-Kobaisi M. , Ramirez B.
Published: April 2009

Accurate calculation of multiphase fluid transfer between the fracture and matrix in naturally fractured reservoirs is a very crucial issue. In this paper, we will present the viability of the use of a simple transfer function to accurately account for fluid exchange resulting from capillary and gravity forces between fracture and matrix in dual-porosity and dual-permeability numerical models. With this approach, fracture- and matrix-flow calculations can be decoupled and solved sequentially, improving the speed and ease of computation. In fact, the transfer-function equations can be used easily to calculate the expected oil recovery from a matrix block of any dimension without the use of a simulator or oil-recovery correlations.

The study was accomplished by conducting a 3-D fine-grid simulation of a typical matrix block and comparing the results with those obtained through the use of a single-node simple transfer function for a water-oil system. This study was similar to a previous study (Al-kandari 2002) we had conducted for a 1D gas-oil system.

The transfer functions of this paper are specifically for the sugar-cube idealization of a matrix block, which can be extended to simulation of a match-stick idealization in reservoir modeling. The basic data required are: matrix capillary-pressure curves, densities of the flowing fluids, and matrix block dimensions.
Multiphysics and Multiscale Methods for Modeling Fluid Flow Through Naturally Fractured Carbonate Karst Reservoirs
Authors: Popov P. , Qin G. , Bi L. , Efendiev Y. , Kang Z. , Li J.
Published: April 2009

Modeling and numerical simulations of Carbonate karst reservoirs is a challenging problem because of the presence of vugs and caves which are connected through fracture networks at multiple scales. In this paper, we propose a unified approach to this problem by using the Stokes-Brinkman equations which combine both Stokes and Darcy flows. These equations are capable of representing porous media (porous rock) as well as free-flow regions (fractures, vugs, and caves) in a single system of equations. The Stokes-Brinkman equations also generalize the traditional Darcy-Stokes coupling without sacrificing the modeling rigor. Thus, it allows us to use a single set of equations to represent multiphysics phenomena on multiple scales. The local Stokes-Brinkman equations are used to perform accurate scale-up. We present numerical results for permeable rock matrix populated with elliptical vugs and we consider upscaling to two different coarse-scale grids— 5×5 and 10×10. Both constant and variable background permeability matrices are considered and the effect the vugs have on the overall permeability is evaluated. The Stokes-Brinkman equations are also used to study several vug/cave configurations which are typical of Tahe oilfield in China.
A New Approach for Reliable Estimation of Hydraulic Fracture Properties Using Elliptical Flow Data in Tight Gas Wells
Authors: Cheng Yueming , Lee W. John , McVay Duane A.
Published: April 2009

Gas wells in low-permeability formations usually require hydraulic fracturing to be commercially viable. Pressure transient analysis in hydraulically fractured tight gas wells is commonly based on analysis of three flow regimes: bilinear, linear, and pseudoradial. Without the presence of pseudoradial flow, neither reservoir permeability nor fracture half-length can be independently estimated. In practice, as pseudoradial flow is often absent, the resulting estimation is uncertain and unreliable. On the other hand, elliptical flow, which exists between linear flow and pseudoradial flow, is of long duration (typically months to years). We can acquire much rate and pressure data during this flow regime, but no practical well test analysis technique is currently available to interpret these data.

This paper presents a new approach to reliably estimate reservoir and hydraulic fracture properties from analysis of pressure data obtained during the elliptical flow period. The method is applicable to estimate fracture half-length, formation permeability, and skin factor independently for both infinite- and finite-conductivity fractures. It is iterative and features rapid convergence. The method can estimate formation permeability when pseudoradial flow does not exist. Coupled with stable deconvolution technology, which converts variable production-rate and pressure measurements into an equivalent constant-rate pressure drawdown test, this method can provide fracture-property estimates from readily available, noisy production data. We present synthetic and field examples to illustrate the procedures and demonstrate the validity and applicability of the proposed approach.
Stress-Dependent Directional Permeabilities of Two Analog Reservoir Rocks: A Prospective Study on Contribution of µ-Tomography and Pore Network Models
Authors: Dautriat J. , Gland N. , Youssef S. , Rosenberg E. , Bekri S. , Vizika O.
Published: April 2009

To predict the effects of stress on rock permeability, the authors propose an integrated approach based on an extended rock characterization, an experimental investigation of pressure dependency of directional rock permeabilities and finally a pore-scale simulation of this dependency using equivalent pore network extracted from microtomography analysis. This study has been conducted on two analog reservoir rock types: the high-permeability Bentheimer Sandstone and a dual-porosity bioclastic carbonate, the Estaillades Limestone, having an intermediate permeability. Compression tests have been conducted using a new triaxial cell specially designed to measure directional permeabilities along and transverse to direction of maximum stress application. We measured the pressure dependency of porosity, directional permeabilities, compressibilities, and elastic moduli of the tested samples. We also performed computed microtomography (CMT) imaging of the rock samples, from which we extracted the poral skeletons and the associated characteristics lengths. Then, we calculated the macroscopic transport properties using Pore Network Modeling (PNM) based on the real pore geometry. We included a model of pressure dependence of pore and throat sizes based on pressurized cavity models derived from elasticity theory to simulate the evolution of porosity and permeability with pressure. First, we show that the experimental determination of the evolution of directional permeabilities under hydrostatic and deviatoric loading is feasible. Finally, we show that the PNM coupled with μ-tomography can be a promising tool to forecast the evolution of transport properties under stresses representative of reservoir conditions, at the condition of integrating more advanced pore-scale compaction models.
Monitoring SAGD Steam Injection Using Microseismicity and Tiltmeters
Authors: Maxwell S. C. , Du J. , Shemeta J. , Zimmer U. , Boroumand N. , Griffin L. G.
Published: April 2009

A combination of microseismic and surface-deformation monitoring with an array of tiltmeters was used to monitor the warm-up phase of a steam-assisted-gravity-drainage (SAGD) well pair. A sequence of microseismic events was recorded with signal characteristics that suggested deformation associated with thermal expansion of the wellbore, in addition to events apparently associated with induced fracturing in the reservoir. Integration of the microseismic data with volumetric strain, inverted from the measured surface deformation, indicates a discrete deforming region near the toe of the well. The volumetric strain also shows another region near the heel of the well, although the area is too far from the microseismic observation well for any associated microseismicity to be recorded. The central portion of the well pair did not have significant deformation, indicating poor steam conformance during this warm-up phase. A comparison of the temporal response of the microseismic deformation with the surface uplift suggests a lag between periods of accelerated seismic deformation followed by an associated period of accelerated uplift a few days later. This timing suggests the creation of a fracture network and related seismic deformation, which then fills with steam and starts to expand over a period of a few days. In a related paper (Du et al. 2007), stress changes associated with the volumetric strain are used to examine potential geomechanical failure zones that match the observed locations of microseisms. Together, the volumetric strain, computed stress changes, and failure zones could be used to calibrate a geomechanically linked reservoir simulator.