136 research outputs found

    Qualidade física de um Latossolo Vermelho avaliada por meio da curva de resistência do solo à penetração.

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    A qualidade física do solo pode ser avaliada por meio da resistência mecânica do solo à penetração (RP) e esta pode ser descrita pela curva de RP (CRP). Objetivou quantificar a influência do tempo de ausência da mobilização do solo em sistemas de manejo sobre a CRP em um Latossolo. Foi utilizado um esquema fatorial 5x2, com quatro repetições. Os fatores manejo do solo foram: sistema de preparo convencional; sistema plantio direto (SPD) escarificado a cada ano e/ou a cada três anos; SPD contínuo por 11 e/ou 24 anos. Os fatores modelos de produção foram: rotação e sucessão de culturas. Foi determinada a CRP (RP, umidade volumétrica e densidade do solo) em três camadas de solo. Para uma mesma situação de densidade do solo a RP sempre foi maior em função do aumento do tempo sem intervenção no solo. Quanto maior o tempo do solo sob SPD, maior foi o aumento da resistência da estrutura do solo. Há necessidade de se estabelecer limites distintos de RP em função do tempo de adoção do SPD

    Estado de compactação de um Latossolo Vermelho com sistemas de manejo e modelos de produção de longo prazo.

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    Ao longo do tempo, é muito importante, a preservação da qualidade física dos solos. Objetivou-se determinar o potencial de modelos de produção e manejos do solo em reduzir o grau de compactação do solo ao longo do tempo, determinando o período residual das intervenções mecânicas. Foi utilizado um esquema fatorial 5x2. O fator manejo do solo foi: sistema de preparo convencional; sistema plantio direto (SPD) escarificado a cada ano e/ou a cada três anos; SPD contínuo por 11 e/ou 24 anos. O fator modelo de produção foi: rotação e sucessão de culturas. Foi avaliada a densidade do solo até 0,30 m. Não foram observadas alterações no solo em função do uso dos modelos de produção. O efeito residual da escarificação do solo se restringiu ao período de dez meses na camada de 0,0-0,20 m. A escarificação periódica do solo em SPD é dispensável, independentemente do modelo de produção. O incremento do tempo de adoção do SPD de 11 para 24 anos favoreceu melhorias na qualidade física do solo

    Curva de retenção de água de um Latossolo sob estados de compactação.

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    A qualidade física do solo tem sido avaliada por diversos parâmetros, dentre estes a densidade do solo, porosidade total e a curva de retenção de água característica do solo (CRA). Objetivou-se avaliar as alterações nas propriedades físicas da CRA de um Latossolo Vermelho submetido a diferentes estados de compactação. Para isso, um experimento foi instalado sobre um Latossolo Vermelho Distroférrico, composto por seis níveis de compactação do solo, obtidos por meio da escarificação do solo e da compactação adicional pelo tráfego de uma colhedora autopropelida de grãos (4, 8, 10 e 20 passadas), além de uma testemunha que foi mantida sob sistema plantio direto sem escarificação e sem compactação adicional. Os pontos da CRA foram ajustados utilizando-se o modelo matemático proposto por van Genuchten (1980). Quatro passadas de uma colhedora com 10,28 Mg causou elevação do nível de compactação do solo acima de níveis considerados como críticos. A CRA foi sensível para identificar alterações na qualidade física do solo em estudo

    A prospective cohort study examining medical and social factors associated with engagement in life activities following total hip replacement

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    Objectives: Studies show limited improvement in the frequency of engaging in life activities after joint replacement. However, there is a paucity of research that has examined factors, including other life events, which influence engagement following total hip replacement (THR). This research sought to identify factors associated with engaging in life activities following THR. Methods: A prospective cohort study was conducted with 376 people who had a THR for osteoarthritis (OA). Data were collected pre-surgery and 1 year post-surgery. The primary outcome was change in frequency in engagement in life activities (Late Life Disability Index (LLDI): higher scores indicate higher frequency of engagement (range 0e80)). Analyses included multivariable regression. Factors considered included: positive/negative life events, a new comorbidity, another joint replacement and complications post-surgery. Results: Participants' mean age was 64 years; 46% were male. 68% of participants had at least one comorbidity pre-surgery; 36% reported at least one new comorbidity after surgery. The mean change in LLDI frequency was an increase of 6.29 (+/- 8.10). 36% reported one or more positive impact life events in the year following surgery; 63% reported one or more negative life events. The number of positive life events (beta=1.24; 95% CI: 0.49, 1.99) was significantly associated with change in LLDI frequency after adjusting for age, sex, education, body mass index (BMI), comorbidities pre-surgery, number of symptomatic joints and pre-surgery pain and function, LLDI limitations and depression. Conclusions: These findings highlight the significant influence of social factors and life circumstances on engagement in life activities following THR. (C) 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Optimization of sample unit size for sampling stink bugs (Hemiptera: Pentatomidae) in soybean

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    Cost-effective and reliable sampling procedures are crucial for integrated pest management. Sweep net sampling is commonly used for stink bugs (Hemiptera: Pentatomidae) in soybean, with sample size being the number of sets of sweeps, and sample unit size the number of sweeps in each set. Sample unit size has received little attention, but can affect sampling parameters. Here, two sample unit sizes (10 vs. 25 sweeps) were compared for the sampling of stink bug taxa. On average, sampling for stink bugs took 3.6 more minutes with the 25-sweep than with the 10-sweep sample unit size. Generally, estimates of the mean number of stink bugs per sweep were similar between the two sample unit sizes for Euschistus spp. and Chinavia hilaris combined (“combined herbivores”) and Euschistus spp. The 25-sweep sample unit size had a higher probability of detecting combined herbivores, Euschistus spp. and Podisus spp., lower standard errors and relative variance for combined herbivores and Euschistus spp., lower standard errors for C. hilaris, and higher relative net precision [which accounts for sampling cost (i.e., time)] for combined herbivores and Euschistus spp. Taken together, the better probability of detection, precision and efficiency of the 25-sweep sample unit size support the continued use of sampling plans developed for that sample unit size. The optimization of sample unit sizes is an important factor that should be accounted for in the development of sampling plans

    Structural and functional characterization of endothelial microparticles released by cigarette smoke

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    Circulating endothelial microparticles (EMPs) are emerging as biomarkers of chronic obstructive pulmonary disease (COPD) in individuals exposed to cigarette smoke (CS), but their mechanism of release and function remain unknown. We assessed biochemical and functional characteristics of EMPs and circulating microparticles (cMPs) released by CS. CS exposure was sufficient to increase microparticle levels in plasma of humans and mice, and in supernatants of primary human lung microvascular endothelial cells. CS-released EMPs contained predominantly exosomes that were significantly enriched in let-7d, miR-191; miR-126; and miR125a, microRNAs that reciprocally decreased intracellular in CS-exposed endothelium. CS-released EMPs and cMPs were ceramide-rich and required the ceramide-synthesis enzyme acid sphingomyelinase (aSMase) for their release, an enzyme which was found to exhibit significantly higher activity in plasma of COPD patients or of CS-exposed mice. The ex vivo or in vivo engulfment of EMPs or cMPs by peripheral blood monocytes-derived macrophages was associated with significant inhibition of efferocytosis. Our results indicate that CS, via aSMase, releases circulating EMPs with distinct microRNA cargo and that EMPs affect the clearance of apoptotic cells by specialized macrophages. These targetable effects may be important in the pathogenesis of diseases linked to endothelial injury and inflammation in smokers

    English language proficiency and the accommodations for language non-concordance amongst patients utilizing chiropractic college teaching clinics

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    Background: The number of households in the United States that are not proficient in the English language is growing and presenting a challenge to the health care system. Over nineteen percent of the US population speak a language other than English in the home. This increase in language discordance generates a greater need to find and implement accommodations in the clinical setting to insure accurate and efficient diagnosis and treatment as well as provide for patient safety. Aim: The purpose of this study is to determine the percentage of patients accessing the chiropractic college teaching clinics who are not proficient in the English language and to what extent the colleges provide accommodations for that language disparity. Methods: The clinic directors and deans of the Association of Chiropractic Colleges were surveyed via an on-line survey engine. The survey queried the percentage of the patient population that is not English language proficient, the accommodations the college currently has in place, if the college has a language specific consent to treat document and if the college has a written policy concerning patients without English proficiency. Results: Fifty percent of the contacted chiropractic colleges responded to the survey. In the respondent college clinics 16.5% of the patient population is not proficient in English, with over 75% speaking Spanish. All but one of the respondents provide some level of accommodation for the language non-concordance. Forty five percent of the responding colleges employ a language specific consent to treat form. The implementation of accommodations and the use of a language specific consent to treat form is more prevalent at colleges with a higher percentage of non-English speaking patients. Conclusions: The percentage of patients with limited English proficiency accessing services at the teaching clinics of the chiropractic colleges mirrors the numbers in the general population. There is a wide disparity in the accommodations that the individual colleges make to address this language discordance. There is a need to further develop accurate and meaningful accommodations to address language disparity in the chiropractic teaching clinics.https://doi.org/10.1186/2045-709X-21-

    Time course of risk factors associated with mortality of 1260 critically ill patients with COVID-19 admitted to 24 Italian intensive care units

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    Purpose: To evaluate the daily values and trends over time of relevant clinical, ventilatory and laboratory parameters during the intensive care unit (ICU) stay and their association with outcome in critically ill patients with coronavirus disease 19 (COVID-19). Methods: In this retrospective–prospective multicentric study, we enrolled COVID-19 patients admitted to Italian ICUs from February 22 to May 31, 2020. Clinical data were daily recorded. The time course of 18 clinical parameters was evaluated by a polynomial maximum likelihood multilevel linear regression model, while a full joint modeling was fit to study the association with ICU outcome. Results: 1260 consecutive critically ill patients with COVID-19 admitted in 24 ICUs were enrolled. 78% were male with a median age of 63 [55–69] years. At ICU admission, the median ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2) was 122 [89–175] mmHg. 79% of patients underwent invasive mechanical ventilation. The overall mortality was 34%. Both the daily values and trends of respiratory system compliance, PaO2/FiO2, driving pressure, arterial carbon dioxide partial pressure, creatinine, C-reactive protein, ferritin, neutrophil, neutrophil–lymphocyte ratio, and platelets were associated with survival, while for lactate, pH, bilirubin, lymphocyte, and urea only the daily values were associated with survival. The trends of PaO2/FiO2, respiratory system compliance, driving pressure, creatinine, ferritin, and C-reactive protein showed a higher association with survival compared to the daily values. Conclusion: Daily values or trends over time of parameters associated with acute organ dysfunction, acid–base derangement, coagulation impairment, or systemic inflammation were associated with patient survival
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