bluuebunny/crossref_metadata_2025 huggingface dataset:
Efeitos de diferentes tipos de exercício nos parâmetros do andar de idosas
Authors: Gonzaga Jozilma de Medeiros , Barros Sandra Emília Benício , Lisboa Maria Goretti da Cunha , Barbieri Fabio Augusto , Gobbi Lilian Teresa Bucken
Published: September 2011

O tipo de exercício, a intensidade e a frequência são fatores importantes para produzir mudanças na velocidade de andar. O objetivo do estudo foi comparar os efeitos de diferentes tipos de exercício nos parâmetros cinemáticos do andar de idosas, considerando as características antropométricas, a capacidade funcional e o nível de atividade física. Participaram do estudo 56 idosas que foram agrupadas de acordo com o envolvimento, a mais de seis meses, na prática específica de uma atividade: dança (n = 10), musculação (n = 10), hidroginástica (n = 12) e caminhada (n = 11). Além disso, um grupo de idosas inativas (n = 13), sem envolvimento em atividade física regular por pelo menos dois meses, também participou do estudo. Foram mensurados o nível de atividade física (Questionário de Baecke), a capacidade funcional (Bateria da AAHPERD) e os parâmetros cinemáticos do andar (comprimento da passada e do passo, duração e velocidade da passada, cadência e duração das fases de suporte simples, balanço e duplo suporte). Os resultados revelaram que o nível de atividade física do grupo Controle foi diferente dos demais grupos que praticam atividades físicas. Em relação à capacidade funcional, apenas o componente força apresentou diferenças entre os grupos, indicando que o grupo Controle difere do grupo musculação. Quanto às variáveis do andar, o grupo Controle foi estatisticamente diferente apenas do grupo dança, tanto no comprimento do passo como no comprimento da passada. Pode-se concluir que a capacidade funcional e os parâmetros do andar dos idosos ativos e sedentários apresentam poucas diferenças
Força de preensão manual de atletas tenistas avaliada por diferentes recomendações de teste
Authors: Pereira Hugo Maxwell , Menacho Maryela de Oliveira , Takahashi Ricardo Hisayoshi , Cardoso Jefferson Rosa
Published: September 2011

A avaliação da força de preensão manual (FPM) em tenistas competitivos deve ser realizada devido à assimetria que o jogador pode desenvolver. Para avaliar a FPM, profissionais utilizam dois protocolos diferentes (das Sociedades Americana e Europeia). Os objetivos deste estudo foram comparar a FPM usando a técnica do European Test of Physical Fitness Handbook (Eurofit) e da American Society of Hand Therapists (ASHT), bem como verificar a FPM entre o lado dominante/contralateral e comparar a FPM entre as idades em atletas de tênis da categoria infanto-juvenil. Participaram do estudo 137 tenistas do gênero masculino e 45 do feminino, todos com idade entre oito e 18 anos. Para avaliar a FPM, segundo as recomendações da Eurofit e ASHT, foi utilizado um dinamômetro manual (Jamar). Nenhum dos sujeitos avaliados apresentava qualquer lesão que pudesse comprometer o teste. Os resultados mostram que não há diferença na FPM entre os posicionamentos recomendados pela Eurofit e ASHT para medir a FPM independente do gênero. A curva sigmoide foi a que melhor se adequou para regressão da FPM e idade em ambos os gêneros sendo que para o masculino a FPM tem maior inclinação aos 11 anos, já para o feminino a maior inclinação é aos 10 anos. Além disso, a partir dos 14 anos, o lado dominante dos atletas masculinos apresentou maior FPM que o lado não dominante; contudo, essa assimetria não ocorreu no feminino em qualquer idade até os 18 anos.
Avaliação isocinética dos músculos extensores e flexores de joelho em jogadores de futebol profissional
Authors: Zabka Felipe Furlan , Valente Henrique Gonçalves , Pacheco Adriana Moré
Published: September 2011

INTRODUÇÃO E OBJETIVOS: Estudos que relacionam parâmetros de desempenho muscular em diferentes esportes, e, especialmente no futebol, têm sido frequentemente reportados na literatura. Entretanto, as variações metodológicas entre os diversos estudos, o tipo de dinamômetro usado em cada pesquisa e o posicionamento dos sujeitos durante as avaliações resultam na divergência dos dados coletados. Portanto, o objetivo deste estudo foi realizar uma coleta de dados que forneçam valores sobre o perfil muscular e estabelecer parâmetros normativos relativos ao desempenho muscular de jogadores profissionais de futebol, fundamentando a pesquisa científica e estudos futuros. MÉTODOS: A amostra consistiu de 39 atletas pertencentes a um clube de futebol de elite da capital gaúcha. Para avaliação do desempenho muscular foi utilizado um dinamômetro isocinético e os testes consistiram de contrações concêntricas máximas, sendo testados os músculos extensores e flexores do joelho nas velocidades 60º/s e 240º/s. Realizou-se a análise das médias através do teste t (amostras independentes) para investigar diferenças bilaterais nos parâmetros avaliados. Para todos os procedimentos estatísticos, o intervalo de confiança foi de 95% (p < 0,05). RESULTADOS: Os resultados deste estudo caracterizaram o perfil muscular de jogadores profissionais do futebol relativo à capacidade de produção de torque, trabalho e potência máxima, normalizados pelo peso corporal. Além disso, foram observadas diferenças significativas entre pernas em algumas variáveis. CONCLUSÃO: Os dados normativos estabelecidos podem ser utilizados como valores de referência na prevenção, treinamento e reabilitação dos atletas, além de servirem de referência para futuros estudos que tenham como objetivo relacionar os parâmetros de desempenho muscular à incidência de lesões no futebol.
Treinamento físico de natação promove remodelamento cardíaco e melhora a perfusão sanguínea no músculo cardíaco de SHR via mecanismo dependente de adenosina
Authors: Barros Juliana Gonçalves de , Redondo Fernanda Roque , Zamo Fernanda de Souza , Mattos Katt Cristina , Angelis Kátia De , Irigoyen Maria Cláudia , Oliveira Edilamar Menezes de
Published: September 2011

INTRODUÇÃO: Exercícios físicos são utilizados como terapia não farmacológica para o tratamento da hipertensão arterial, e o treinamento físico (TF) por natação é reconhecido por produzir remodelamento cardíaco em animais experimentais. Entretanto, a ação vasodilatadora da adenosina (ado) resultante do exercício físico como prevenção e tratamento da hipertensão é pouco explorada. OBJETIVO: Avaliar o remodelamento cardíaco e o papel da adenosina na distribuição do fluxo sanguíneo para o miocárdio após treinamento físico em SHR. Método: 28 SHR machos babies e adultos foram submetidos ao TF aeróbio de natação, durante 10 semanas (5x/sem -1h/dia). Foram utilizados protocolos de microesferas coloridas para avaliar fluxo sanguíneo, técnicas de morfologia para avaliar hipertrofia cardíaca e análises bioquímicas para verificar atividade de enzimas envolvidas na formação de adenosina. RESULTADOS: TF por natação atenuou a evolução da HA em SHR babies (S: 145 ± 2; T: 140 ± 2mmHg), promoveu bradicardia de repouso em SHR adultos (S: 340 ± 4; T: 321 ± 6bpm) e desenvolveu HC nos dois grupos (TB: 12%; TA: 10%). Na condição basal, o TF aumentou o FS coronário em SHR babies (S: 4.745 ± 2.145; T: 6.970 ± 2.374mi/coração) e maior resposta vasodilatadora à infusão de adenosina foi observada (S: 18.946 ± 6.685; T: 25.045 ± 7.031mi/coração). Neste grupo, o TF promoveu maior atividade da enzima 5'-nucleotidase, levando à maior formação de adenosina (S: 0,45 ± 0,09; T: 1,01 ± 0,05). CONCLUSÃO: O TF de natação, além de desenvolver HC e apresentar maior hidrólise de AMP, promoveu aumento no FS coronário, sendo mostrado que desempenha um importante papel na regulação da hipertensão
Treinamento em natação com baixa intensidade não protege músculo esquelético contra lesões induzidas por exercício exaustivo em ratos
Authors: Silva Edson da , Maldonado Izabel Regina dos Santos Costa , Matta Sérgio Luís Pinto da , Maia Giselle Carvalho , Bozi Luíz Henrique Marchesi , Silva Karina Ana da , Castro Cynthia Aparecida , Natali Antônio José
Published: September 2011

Enquanto o exercício aeróbico regular promove adaptações benéficas ao músculo esquelético, o exercício físico exaustivo induz lesões musculares. O objetivo deste estudo foi verificar se um programa de natação com baixa intensidade é capaz de proteger músculos esqueléticos contra lesões induzidas por exercício exaustivo. Ratos Wistar (peso: 376,50 ± 4,36g; idade: 90 dias) foram divididos aleatoriamente em quatro grupos: controle sedentário (CS); sedentário submetido a teste de exaustão (SE); treinado em natação (TN); treinado em natação submetido a teste de exaustão (TNE). Animais dos grupos TN e TNE foram submetidos a um programa de natação sem sobrecarga por 90 minutos/dia, cinco dias/semana, durante 17 semanas. Após este período, os grupos SE e TNE foram submetidos a um teste de exaustão em natação. Após eutanásia, fragmentos dos músculos sóleo e reto femoral foram coletados e submetidos à análise histológica e de proteínas de choque térmico (HSP70). Os resultados mostraram que o tempo até a exaustão foi maior no grupo TNE que no SE (125,0 ± 6,0 vs. 90,0 ± 8,5min, respectivamente, P < 0,05). Os níveis de lactato sanguíneo durante o teste e exaustão foram menores no grupo TNE que no SE (5,31 ± 0,22 vs. 8,76 ± 0,59mmol/L, respectivamente, P < 0,05). A frequência de fibras lesadas nos músculos foi maior nos grupos SE (sóleo: 34,86 ± 0,04; reto femoral: 37,57 ± 0,07) e TNE (sóleo: 41,57 ± 0,08; reto femoral: 39,57 ± 0,05), comparada aos grupos CS (sóleo: 13,88 ± 0,81; reto femoral: 16,75 ± 0,79) e TN (sóleo: 24,14 ± 0,06; reto femoral: 24,0 ± 0,05), respectivamente (P < 0,05). Não houve diferença significativa nos níveis de HSP70 dos músculos analisados entre os quatro grupos. Concluimos que apesar do treinamento em natação melhorar o desempenho dos animais no teste de exaustão, não promoveu proteção aos seus músculos esqueléticos contra as lesões induzidas pelo exercício exaustivo
The effect of mouthrinses against oral microorganisms
Authors: Cortelli José Roberto , Thénoux Raul Emilio de La Sotta
Published: September 2011

This paper reviews the benefits of the use of antimicrobial mouthrinses for controlling dental biofilm. It is currently known that the human oral cavity is inhabited by approximately 600 to 700 different species of microorganisms, including bacteria, fungi and viruses, organized in biofilms. Biofilm accumulation represents the principal etiologic agent of oral diseases including caries and periodontal diseases. For that reason, prevention of biofilm accumulation has been shown to be associated with the control of diseases. Patient motivation and oral hygiene instruction are claimed to be a major factor influencing the degree of biofilm control. Therefore, mechanical home-care methods, including toothbrushing and flossing, represent the best way for patients to remove biofilm. For many patients, however, the elimination of all biofilm present in the oral cavity through home-care methods could be tedious and time-consuming. Additionally, some local conditions, including malpositioned teeth, presence of bridge-work or orthodontic appliances, among others, may render the mechanical control of biofilm especially difficult. Chemotherapeutic agents, including mouthrinses, could have a key role as adjuncts to daily home care, preventing and controlling supragingival plaque, gingivitis and oral malodor. Indeed, according to the ADA, the active ingredients of mouthwashes must demonstrate a therapeutic effect in vivo and in vitro to be classified as drugs. Several studies included in the present review have demonstrated the effectiveness of mouthrinses containing active ingredients such as chlorhexidine and essential oils in preventing and controlling both supragingival plaque and gingivitis, especially when used adjunctively to regular toothbrushing and flossing procedures.
Age and oral health: current considerations
Authors: Tawse-Smith Andrew
Published: September 2011

Dental plaque is still considered the main etiological factor for periodontal diseases. Our understanding of periodontal disease has advanced from the previous concepts where gingivitis slowly progressed to periodontitis to a more complex scenario that correlates several risk factors in the pathogenesis of periodontal disease. Among these factors, age has been associated with increased rates of periodontal disease as the population gets older. Although the loss of alveolar bone and periodontal attachment is common in the elderly population, and there is evident age-related changes in the periodontium, severe periodontitis is not a natural consequence of ageing. The importance of identifying the risk factors that participate in the pathogenesis of periodontal disease at an early phase, both of the individual and the disease, as well as evaluating the capacity of the individual to control dental plaque will enable the implementation of an adequate preventive program, where the needs and limitations of the individual are considered to specifically tailor the oral hygiene procedures and the mouthwashes to be used.
Effects of Herbicide, Tillage, and Grass Seeding on Wild Chervil (Anthriscus sylvestris)
Authors: Miller Timothy W. , D'Auria Danielle E.
Published: September 2011

Wild chervil is an invasive biennial or short-lived perennial weed introduced into North America that negatively impacts forage production and degrades habitat for native plant species. A 2-yr study using prebloom mowing followed by combinations of herbicide, tillage, and grass seeding was conducted in the Pacific Northwest to identify an effective integrated weed management strategy for this species. By 2 mo after herbicide treatment (MAHT), wild chervil control with glyphosate + ammonium sulfate (AMS) and clopyralid was 83 and 73%, respectively. Tillage with or without herbicide pretreatment resulted in 92 to 98% wild chervil control at 2 MAHT, whereas herbicide without tillage gave only 45% control across all treatments. Tillage with or without subsequent grass seeding reduced wild chervil density four-fold compared to herbicide alone at 9 MAHT. Herbicide + tillage + grass seeding resulted in similar wild chervil cover (1 to 5% cover) as herbicide + tillage (1 to 6% cover) without subsequent grass seeding. Wild chervil biomass at 1 yr after herbicide treatment (YAHT) was reduced to 487 kg ha−1 (439 lb ac−1) with herbicide + tillage compared to 4,256 kg ha−1 for herbicide treatment alone. Herbicide + tillage + grass seeding increased grass dry weight at 1 YAHT from 201 kg ha−1 for herbicide + tillage to 1,575 kg ha−1, compared to 351 kg ha−1 in herbicide-only plots.
Herbicide Management of Umbrella Dracaena (Dianella ensifolia) in a Florida State Park
Authors: Hutchinson Jeffrey T. , Gandy Elizabeth A. , Langeland Kenneth A.
Published: September 2011

We evaluated herbicide treatments for control of umbrella dracaena, locally invasive in central Florida. Biannual treatments of imazapyr (3.2 and 6.4 g ai L−1), metsulfuron (0.08 and 0.16 g ai L−1), and imazapyr (0.8 g ai L−1) plus glyphosate (19.9 g ai L−1) reduced cover to < 3% at 12 mo, but no treatment eliminated the plant. In contrast, a single treatment on individual potted plants in greenhouse trials was highly effective with ≥ 98% necrosis/chlorosis at 6 mo and no regrowth at 9 mo posttreatment for most treatments. Management of umbrella dracaena will require more than two herbicide treatments with imazapyr, metsulfuron, glyphosate, or a combination of these herbicides if eradication is to be achieved. Because it is currently problematic and localized in one specific area in about 40 ha, it should be a high management priority before it spreads throughout Florida and possibly other states.
Predator Interference with the Cinnabar Moth (Tyria jacobaeae) for the Biological Control of Tansy Ragwort (Senecio jacobaea)
Authors: Crider Kimberly K.
Published: September 2011

Quantification of interference with biological control agents can provide support for anecdotal claims of success or failure of agent establishment and efficacy. This study was initiated because of observed predation of cinnabar moth larvae by carpenter ants when releasing larvae for the control of tansy ragwort, an invasive plant in Montana. Biotic and abiotic factors were compared among three sites with historically variable moth population establishment. Two experiments were developed to (1) observe and document insect activity, predation, or disappearance on tansy ragwort stems either protected or accessible to ants; and (2) quantify the effects of ant exclusion on herbivory of tansy ragwort. Site comparisons indicated that ant colony density was highest at the driest of three sites, and, interestingly, no ant colonies were detected at the site with higher observed numbers of moth larvae and adults and lower densities of tansy ragwort. Available substrate (logs and stumps) for ant colonization did not differ between the three sites. In the ant exclusion experiments, a larger number of larvae were missing on plants accessible to ants (63%) compared with plants where ants were excluded (39%) after 36 h. Direct observation of predation of larvae by carpenter ants accounted for 9% of missing larvae on stems accessible to ants. Larvae were able to consume 81% of original flowers or buds on ant-excluded stems, compared with 18% consumption on ant-accessible stems, suggesting that ant predation could limit the efficacy of cinnabar moth larvae. These results provide one of many possible explanations for the anecdotal observations of large, persistent populations of cinnabar moths in moist areas. This work emphasizes the importance of post-release observation and monitoring to detect and, ideally, quantify factors to support anecdotal perceptions regarding the fate and subsequent efficacy of insect biological-control agents.
Invasion Prediction on Alaska Trails: Distribution, Habitat, and Trail Use
Authors: Bella Elizabeth M.
Published: September 2011

Little is known about the relationship between frequency of occurrence and the expected maximum distance a nonnative species might spread along a trail once introduced to an ecological system with high native species integrity. Understanding how colonization and invasive plant habitat degradation occur in largely intact ecosystems is challenging. Determining which nonnative species are most likely to spread might be possible, given a suite of environmental or trail conditions. Spread may be linked to a particular set of environmental conditions, or to type and level of trail use. A field study conducted on trails in Forest Service and State Park lands on the Kenai Peninsula, Alaska, was designed to determine frequency and spread distance of all nonnative vascular plant species per 100-m segments keyed to vegetation type, canopy cover class, aspect, trail use level, and trail use type. Although the maximum total number of nonnative species decreased with increased distances from trailheads, the average number of species remained nearly constant. Common dandelion, broadleaf plantain, and annual bluegrass exhibited consistent presence per canopy cover class or vegetation type. A nested subset analysis revealed a significant reduction in nonnative species presence beyond a 500-m distance from a trailhead and a moderately strong nestedness pattern. High-use trails exhibited the greatest numbers of nonnative species at the farthest distances from the trailhead and contained a greater number of less common nonnative species. Alaska and other northern biomes have relatively few widespread invasive problems, offering an opportunity to limit ecosystem degradation by invasion. Results suggest that control strategies might focus on high-use trails with open-canopy habitats to prevent spread.
Colonization and Effects of Garlic Mustard (Alliaria petiolata), European Buckthorn (Rhamnus cathartica), and Bell's Honeysuckle (Lonicera × bella) on Understory Plants After Five Decades in Southern Wisconsin Forests
Authors: Rooney Thomas P. , Rogers David A.
Published: September 2011

Preinvasion baseline data on entire communities are absent for most taxa in most places, and this limits our ability to connect long-term ecological changes to particular invasive species or invasion events. We obtained data on forest understory composition from 94 stands in the 1950s and again the 2000s. We recorded within-stand frequency of occurrence for garlic mustard, European buckthorn, and Bell's honeysuckle and identified changes in native plant species density in 20, 1-m2 quadrats in invaded and noninvaded stands. All three invasive species were absent from all study sites 50 yr ago, yet at least one was present in 77.7% of the stands by the 2000s. All three species were present in 14.9% of the stands. Garlic mustard and European buckthorn were found at 47.9% of resurveyed sites, and Bell's honeysuckle was found in 40.4% of resurveyed sites. Native understory plant species density declined an average of 23.1% during the past 50 yr. Declines were not significantly different in stands with or without invasive plants. The absence of a measurable effect by invasive plant presence or frequency could be due to invasive plants being too few to have a measurable effect at the plot scale, species density being an insensitive response variable, time lags between invasions and effects, or regional factors like development pressure and fire suppression driving density declines in both invasives and native species.
Corallita (Antigonon leptopus): Intentional Introduction of a Plant with Documented Invasive Capability
Authors: Burke Janelle M. , DiTommaso Antonio
Published: September 2011

Corallita (Antigonon leptopus) is a perennial vine, lauded as an ornamental for its vigorous growth, and plentiful (usually) pink flowers, and even its ability to smother unsightly landscapes. In the United States it thrives in horticultural zones 8 to 10, and also is successfully grown worldwide in tropical climates. When corallita is neglected, it can grow quickly over other vegetation, spreading beyond its area of introduction. Once established, it is difficult to eradicate because it produces many tuberous roots that can propagate vegetatively. Its fruits are buoyant, allowing for successful seed dispersal in water. The islands of Guam (South Pacific Ocean) and St. Eustatius (Caribbean Sea) represent two regions where corallita has become so pervasive that it threatens local diversity. In Florida, already it is classified as a Category II invasive. Our report reviews the literature and past studies of corallita, in addition to adding new taxonomic and distribution information from herbarium specimens to clarify the identity and geographic range. It is recommended that introductions of this plant by the horticultural industry in both tropical and temperate regions be closely monitored to prevent spread. On tropical island nations, we advise against any new introductions.
Seed Mass, Viability, and Germination of Japanese Stiltgrass (Microstegium vimineum) under Variable Light and Moisture Conditions
Authors: Huebner Cynthia D.
Published: September 2011

The success of Japanese stiltgrass as an invader may be due to its ability to respond to stochastic events (e.g., by sexual reproduction via chasmogamous [CH] flowers) and to maintain a beneficial genetic make-up (e.g., by self-fertilizing via cleistogamous [CL] flowers) when conditions are stable. This paper evaluates the importance of Japanese stiltgrass seed type (chasmogamous seeds, cleistogamous seeds, and seeds originating from forest-interior [F-I] plants) in terms of seed mass, viability, and germination across variable moisture regimes (three regions in West Virginia) and at two light levels (roadside and forest interior). Seeds from nine populations were sampled in three site types in 2005 and 2008 and stored at 5 C until testing in April 2009. Seeds were tested for viability using a dye test. Seeds were germinated under both constant and fluctuating day/night temperatures. Additional samples of CH and CL seeds collected in 2008 were tested for viability again in September 2010 for a measure of seed longevity. CL and F-I seeds were smaller in mass than CH seeds. Seeds from the drier sites were smaller in mass than seeds from the more mesic sites. CL seeds, followed by F-I seeds, were less viable than CH seeds in 2005 and 2008. CL and F-I seeds had lower germination rates than CH seeds for each site type in 2005, but germination rates of the seed types did not differ in 2008. Differences in seed longevity for 2008 seeds were lower for CL compared to CH seeds, but only in the drier sites. Japanese stiltgrass' longer-lived and larger CH seeds from the roadsides may ensure population survival over the long term. Younger CL and F-I seeds differ less from CH seeds in terms of germination than older seeds, which may help Japanese stiltgrass to maintain populations under relatively stable conditions in the short term.
Does Superior Competitive Ability Explain Yellow Starthistle's (Centaurea solstitialis) Successful Invasion of Annual Grasslands in California?
Authors: Spencer David , Enloe Stephen , Liow Pul-Sze , Ksander Greg , Carruthers Raymond
Published: September 2011

Yellow starthistle represents one of the most spectacular examples of biological invasion in the western United States. However, the mechanisms leading to its success have not been clearly elucidated. Although its success has been attributed to superior competitive ability, few competition studies have been performed with yellow starthistle to test this assertion. Yellow starthistle and wild oat (a dominant component of California annual grasslands) were grown in monocultures and mixtures to assess the strength of competitive interactions between them. For either species, intraspecific competition exerted a greater influence over mean plant weight than did interspecific competition. A companion study revealed temporal separation in the phenology of these plants, explaining the weak role of interspecific competition. Additional measurements of growth and soil moisture dynamics in large 270-cm-tall by 50-cm-diam polyvinyl chloride columns also showed a lack of interspecific competition and confirmed that water use patterns differed between these species, indicating niche partitioning. Wild oat reduced soil moisture to 5% but only to a depth of approximately 150 cm. Yellow starthistle depleted soil moisture to less than 5% throughout the column to a depth of at least 270 cm. These patterns were present when wild oat and yellow starthistle were grown individually or together in the columns, indicating that yellow starthistle had a greater impact on soil moisture and to greater depths. Yellow starthistle's invasion of grasslands in California does not appear to be due to superior competitive ability, but may be due to its ability to access deeper soil moisture. These results support the empty niche hypothesis that implies that invasive species are successful in new habitats because they access resources not available to resident species.
A simplified analytical model for predicting the shear behaviour of regular triangular rock/concrete joints under constant normal stiffness
Authors: HAQUE A. , KODIKARA J.
Published: September 2011

In developing a shear strength model for rock joints, it is essential to understand the shear behaviour of idealised elastic asperities. In this paper, the shear behaviour of regular triangular elastic asperities subjected to constant normal stiffness (CNS) boundary conditions is examined for a range of Young's moduli of the rock. The results show that dilation of the joint decreases with a decrease in rock Young's modulus, because of the increased elastic deformation of asperities. Finally, a simplified analytical model for predicting the peak shear strength of regular triangular concrete/rock joints is developed, incorporating a non-dimensional equation for joint normal stiffness.
Competencies for the intelligent public sector construction client
Authors: Aritua Bernard , Male Steve , Bower Denise , Madter Nancy
Published: September 2011

It is widely accepted that an organisation’s performance is closely linked to the people working within it. Hence, the success or otherwise of the intelligent client in the delivery of major public infrastructure is closely linked to identifying the right individuals for the right positions. Multiple case studies research on the current and future challenges in delivering major public infrastructure has shown that the critical roles representing the intelligent client are under strain. The declining numbers and profile of individuals in key roles suggest difficulties in the future. Moreover, clear deficiencies exist at the front end of current schemes, when critical decisions are made about policy, desired public service aspirations and concepts of design outcomes. To face these challenges, the competencies needed to fulfil the intelligent client role need to be clarified. This should enable the public sector to engage more productively with the private sector and to obtain value for money. A socio-technical systems conception of the endeavour to deliver major infrastructure suggests an alternative basis for fulfilling the intelligent client roles.
Resilience and regime change in a southern Rocky Mountain ecosystem during the past 17 000 years
Authors: Minckley T. A. , Shriver R. K. , Shuman B
Published: September 2011

Paleoecological records indicate that subalpine forests in western North America have been resilient in response to multiple influences, including severe droughts, insect outbreaks, and widely varying fire regimes, over many millennia. One hypothesis for explaining this ecosystem resilience centers on the disruption of forest dynamics by frequent disturbance and climatic variability, and the resulting development of non‐steady‐state regimes dominated by early‐successional conifers with broad climatic tolerances, such as lodgepole pine (Pinus contorta var. latifolia Engelm. ex Wats.). To evaluate this hypothesis, we independently reconstructed the vegetation, fire, and effective‐moisture histories of a small, forested watershed at 2890 m elevation in southeastern Wyoming, USA, using sedimentary pollen and charcoal counts in conjunction with sedimentary lake‐level indicators. The data indicate that prominent vegetation shifts (from sagebrush steppe to spruce–fir parkland at ca. 10.7 ka and spruce–fir parkland to pine‐dominated forest at ca. 8.5 ka [ka stands for thousands of years before the present, defined as AD 1950]) coincided with changes in effective moisture. However, after lodgepole pine forests established at ca. 8.5 ka, similar hydroclimatic changes did not produce detectable vegetation responses. Fire history data show that other aspects of the ecosystem were responsive to changes in effective moisture at centennial timescales with prolonged fire‐free episodes coinciding with periods of low effective moisture ca. 7.2–5.6 and 3.7–1.6 ka. Throughout our record, the ratio of ecosystem perturbation time (i.e., fire frequency and changes in effective moisture) to recovery time (assuming 200–600‐year successional processes) falls within estimates of the ratio for non‐steady state ecosystems. Frequent perturbations, therefore, may have prevented this ecosystem from reaching compositional equilibrium with the varied climatic conditions over the past 8.5 ka. Equilibrium states could have included more abundant spruce (Picea spp.) and fir (Abies spp.) than presently observed based on brief increases in pollen abundances of these taxa during prolonged dry, fire‐free intervals. Our results show that, although current climate changes favor widespread disturbance in Rocky Mountain forests, the composition of these ecosystems could be highly resilient and recover through successional dynamics over the next few decades to centuries.
Recent tectonic reorganization of the Nubia-Eurasia convergent boundary heading for the closure of the western Mediterranean
Authors: Billi Andrea , Faccenna Claudio , Bellier Olivier , Minelli Liliana , Neri Giancarlo , Piromallo Claudia , Presti Debora , Scrocca Davide , Serpelloni Enrico
Published: September 2011

In the western Mediterranean area, after a long period (late Paleogene-Neogene) of Nubian (W-Africa) northward subduction beneath Eurasia, subduction has almost ceased, as well as convergence accommodation in the subduction zone. With the progression of Nubia-Eurasia convergence, a tectonic reorganization is therefore necessary to accommodate future contraction. Previously-published tectonic, seismological, geodetic, tomographic, and seismic reflection data (integrated by some new GPS velocity data) are reviewed to understand the reorganization of the convergent boundary in the western Mediterranean. Between northern Morocco, to the west, and northern Sicily, to the east, contractional deformation has shifted from the former subduction zone to the margins of the two back-arc oceanic basins (Algerian-Liguro-Provençal and Tyrrhenian basins) and it is now mainly active in the south-Tyrrhenian (northern Sicily), northern Liguro-Provençal, Algerian, and Alboran (partly) margins. Onset of compression and basin inversion has propagated in a scissor-like manner from the Alboran (c. 8 Ma) to the Tyrrhenian (younger than c. 2 Ma) basins following a similar propagation of the cessation of the subduction, i.e., older to the west and younger to the east. It follows that basin inversion is rather advanced on the Algerian margin, where a new southward subduction seems to be in its very infant stage, while it has still to really start in the Tyrrhenian margin, where contraction has resumed at the rear of the fold-thrust belt and may soon invert the Marsili oceanic basin. Part of the contractional deformation may have shifted toward the north in the Liguro-Provençal basin possibly because of its weak rheological properties compared with those of the area between Tunisia and Sardinia, where no oceanic crust occurs and seismic deformation is absent or limited. The tectonic reorganization of the Nubia-Eurasia boundary in the study area is still strongly controlled by the inherited tectonic fabric and rheological attributes, which are strongly heterogeneous along the boundary. These features prevent, at present, the development of long and continuous thrust faults. In an extreme and approximate synthesis, the evolution of the western Mediterranean is inferred to follow a Wilson Cycle (at a small scale) with the following main steps : (1) northward Nubian subduction with Mediterranean back-arc extension (since ~35 Ma); (2) progressive cessation, from west to east, of Nubian main subduction (since ~15 Ma); (3) progressive onset of compression, from west to east, in the former back-arc domain and consequent basin inversion (since ~8–10 Ma); (4) possible future subduction of former back-arc basins.
The GROSMarin experiment: three dimensional crustal structure of the North Ligurian margin from refraction tomography and preliminary analysis of microseismic measurements
Authors: Dessa Jean-Xavier , Simon Soazig , Lelievre Marjorie , Beslier Marie-Odile , Deschamps Anne , Bethoux Nicole , Solarino Stefano , Sage Françoise , Eva Elena , Ferretti Gabriele , Bellier Olivier , Eva Claudio
Published: September 2011

The deep structure of the North Ligurian margin and its contiguous Ligurian basin as well as the seismicity recorded in these zones are neither well understood nor precisely constrained. In order to better address these questions, there is a need for offshore instrumenting, which was realised for a duration of nearly 6 months during the GROSMarin (Grand Réseau d’Observation Sous-Marin) experiment. An array of 21 ocean bottom seismometers was deployed over the most active area of the margin and was complemented on land by mobile seismological stations that densified existing permanent networks. We also realised the acquisition of deep refraction seismic shots at sea in order to get a 3D distribution of velocities along the margin through travel time tomography. We present here a preliminary analysis of the seismicity recorded during this experiment and a tomographic model of the margin structures obtained using data from the offshore network only. Our results support the existence of a high velocity zone at the base of a domain interpreted as transitional between continental and oceanic ones, on the northern part of the deep basin. A very similar pattern is observed across the neighbouring margin of the Gulf of Lions and is most likely related to serpentinisation of the underlying mantle during late rifting and continental break-up. North of this transition zone, we observe the basinward crustal thinning of the continental crust beneath the margin that seemingly narrows eastward. To the south, our results hint at transition to the oceanic domain. In contrast, our velocity distribution does not reveal a transition along strike between transitional and oceanic domains, as previous works suggest. Some microseismic activity was recorded throughout the duration of the experiment, on land and at sea. The number of detected events and precision of location were both improved by our considering French and Italian permanent networks. The detection capabilities of our dense network still need to be fully exploited.
Contribution to the seismic hazard assessment of a slow active fault, the Vuache fault in the southern Molasse basin (France)
Authors: Baize Stéphane , Cushing Marc , Lemeille Francis , Gelis Céline , Texier David , Nicoud Gérard , Schwenninger Jean-Luc
Published: September 2011

The Vuache fault is a prominent structure cutting the southernmost Swiss Molasse basin, from the Subalpine massifs to the Jura range. It controls a superficial (0 to 3 km), moderate (moment magnitude ≤ 5) and recurrent (a few events per century) seismicity. In order to address the seismic hazard associated to this fault, we compiled existing data, performed new field investigations and reprocessed existing seismic lines. The newly acquired data validate the hypothesis of an active structure. Its imprint in the landscape and its Quaternary long-term activity are demonstrated, especially by the offset of incised small valleys. Some sites also reveal the occurrence of Quaternary deposits deformed along the fault. Despite the alternative interpretation (glacitectonism) already published, we favour the hypothesis of a tectonic origin for some of them. Concerning the fault slip rate, dating problems preclude definitely addressing the issue, but regional correlations suggest that long-term slip rate ranges from 0.15 to 0.4 mm/a. In addition, as previously concluded by other authors, there is probably a basement fault beneath the surface structure. A connection between the two is not completely demonstrated because of the poor quality of the seismic line at the key point, but this hypothesis should nonetheless be considered in seismic hazard assessment. The relative weight of a deep-seated fault (up to 10 or 15 km into the brittle crust) hypothesis may be low because the well-established data fit more with a scenario of shallow fault producing moderate to low magnitude earthquake. This hypothesis – which would drastically increase the possible maximum magnitude – should not however be neglected in seismic hazard assessment, especially because the coseismic origin of deformations in La Petite Balme is still a possible alternative.
Learning from the post-earthquake mission following the L’Aquila earthquake
Authors: Juster-Lermitte Sandrine , Fournely Eric , Lamadon Thierry , Juraszek Nicolas
Published: September 2011

Following the L’Aquila earthquake in 2009, AFPS (French Association of Earthquake Engineering) sent a mission to investigate the effects of this earthquake (seismological, structural and societal aspects were investigated). It has been observed that most of the damaged buildings were generally irregular in plan and/or in elevation and that their design details were not suitable to take into account the seismic risk. The damaged structures were generally located in the vicinity of L’Aquila, in a square area of 400 km2. This article presents the main observations of this mission regarding the structural behaviour of typical buildings in the L’Aquila surrounding, and investigates the advantage of a capacity design analysis. A special consideration is given to soil configurations in this area and will be related to each structural approach.
Correlating Particle Shape Parameters to Bulk Properties and Load Stress at Two Water Contents
Authors: Miller Nathaniel A. , Henderson Jason J.
Published: September 2011

Particle shape of prospective root‐zone sands is evaluated qualitatively, but a quantitative shape determination may be more useful for sand selection. The objectives of this research were to: determine how particle shape complexity relates to bulk density, total porosity, and mechanical behavior (resistance to displacement given a vertical load); correlate quantitative shape parameters to these properties; determine how water content influences these relationships; and establish if quantitative shape parameters can be used to predict mechanical behavior in the absence of turfgrass roots. Seven materials of various shapes were separated into the medium size class (0.25–0.50 mm) to limit variability introduced by particle size distribution. A dynamic, digital imaging machine was used to quantify particle sphericity, symmetry, and aspect ratio. Bulk density, total porosity, and stress at multiple displacements were determined for the materials at two water contents, oven‐dry and 5% gravimetric water content. As sphericity, symmetry, and aspect ratio increased, bulk density increased and total porosity decreased. Sphericity, symmetry, and aspect ratio were negatively correlated with stress under a vertical load. The addition of water at compaction did not affect the correlations of the shape parameters with either bulk density or porosity; correlations of symmetry and sphericity with these were stronger at 5% water content for some displacements. Multiple regression analysis indicated that sphericity can be used to predict stress characteristics of sands compacted at 5% water content for specific testing conditions. These data indicate that particle shape complexity is related to bulk properties and has potential for predicting the stress characteristics of prospective root zone materials before construction.
Seeding Rate Effects on Soybean Height, Yield, and Economic Return
Authors: Chen Guihua , Wiatrak Pawel
Published: September 2011

The high cost of soybean [Glycine max (L.) Merr.] seed has increased the importance of determining the optimum seeding rates for maximum yield and economic return. Previous research has evaluated vegetation indices of soybean cultivars in five maturity groups (MG IV, V, VI, VII, and VIII) at six seeding rates (68,000; 136,000; 204,000; 272,000; 340,000; and 408,000 seeds ha−1) under dryland conditions on a loamy sand soil in the southeastern Coastal Plain from 2007 to 2009. This study evaluated the effects of soybean seeding rate in 96‐cm rows on mature plant height, grain yield, and economic return, and determined the optimum seeding rates. Plant height increased with increasing seeding rate for MGs IV, VII, and VIII in 2 of 3 yr and for MGs V and VI in all 3 yr. For MG V in 2009, and VII and VIII in 2008, optimum seeding rates were 255,200; 228,200; and 342,500 seeds ha−1, respectively, at maximum yield, and 230,600; 179,100; and 325,900 seeds ha−1, respectively, at maximum economic return. For MG IV in 2008 and VI in 2009, economic return decreased linearly with seeding rate. Seeding rates that produced economic returns within $2.50 ha−1 of the maximum across years were 136,000; 208,600 to 252,600; 136,000; ≥ 172,300; and 308,400 to 343,200 seeds ha−1 for soybean cultivars in MG IV, V, VI, VII, and VIII, respectively. These results suggest that optimum seeding rate varies for cultivars in different MGs and could be lower than current recommendations for MGs IV, VI, and VII, but higher for MG VIII.
Agronomic Responses of Corn to Planting Date and Plant Density
Authors: Van Roekel Ryan J. , Coulter Jeffrey A.
Published: September 2011

Corn (Zea mays L.) grain yield is closely related to plant density and is typically maximized in the northern Corn Belt when planting occurs in late April. However, spring rainfall events often result in wet soil conditions that delay planting. From 2008 to 2010, experiments were conducted at two locations in southern Minnesota to determine whether the agronomic responses of corn to plant density differ with planting date. Six plant densities ranging from 38,400 to 107,900 plants ha−1 were evaluated within three planting dates that occurred on 2‐wk intervals beginning in late April to early May. Yield and net return to seed cost were not affected when planting was delayed 2 wk, but were 15 and 18 to 30% lower when planting was delayed 4 wk, respectively. Yield loss due to late planting was associated with a 7% decrease in kernel weight and no change in kernels per square meter. Responses to plant density for stalk diameter, intercepted photosynthetically active radiation (IPAR) and leaf area index (LAI) at silking, lodging, grain yield and components, and net return to seed cost for 25 economic scenarios did not differ with planting date. There was a quadratic‐plateau response of grain yield to plant density with yield maximized at ≥81,700 plants ha−1. These results from a 102‐d relative maturity hybrid over six site‐years in southern Minnesota show that increased plant density may not be able to offset the yield and economic losses associated with late planting.
Long‐Term Tillage and Poultry Litter Impacts on Soybean and Corn Grain Yield
Authors: Watts Dexter B. , Torbert H. Allen
Published: September 2011

Reduced tillage, poultry litter applications, crop rotations, and winter cover cropping are management practices that could be used with conservation tillage systems to increase yields compared to conventional monoculture systems. This study evaluated cropping sequences of corn (Zea mays L.), soybean [Glycine max (L.) Merr.], and corn–soybean rotations with wheat (Triticum aestivum L.) covers in conventional, strip, and no‐tillage (no‐till) systems, following poultry litter additions to wheat cover. The study was conducted from 1991 to 2001 on a Hartsells fine sandy loam (fine‐loamy, siliceous, subactive, thermic Typic Hapludults). Poultry litter (112 kg N ha−1) was applied to wheat each year in fall. Wheat not receiving poultry litter received equivalent inorganic N. Corn was fertilized with inorganic fertilizer in spring with 56 kg N ha−1 at planting followed by 168 kg N ha−1 3 wk after emergence; soybean received no fertilizer. Corn yields were influenced by tillage in 1991, 1992, 1993, 1994, 1996, 1997, 1998, and 2001 with conventional tillage producing greater yields, except in 1993 (strip tillage) and 2001 (no‐till). Poultry litter increased corn yield in 1991, 1997, and 1998. Crop rotations increased corn yield for all years, except 2001. Soybean yields were not impacted by differences in tillage. Crop rotations significantly impacted soybean yield in 1992, 1995, and 1998, with higher yields observed in 1992, and 1995, and lower yields in 1998. Poultry litter significantly increased soybean yield 8 of the 9 yr evaluated. This study suggests that poultry litter use for these crop rotations in conservation tillage systems could increase sustainable yield production.