Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Sci Rep ; 13(1): 20694, 2023 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-38001336

RESUMO

The invasion of ecosystems by non-native species is recognized as one of the most significant global challenges, particularly in semiarid regions where native biodiversity is already under stress from drought and land degradation. The implicit assumption is that invaders are strong competitors, but a greenhouse pairwise experiment conducted to examine intraspecific and interspecific competition effects of Opuntia ficus-indica, a widespread invader in semiarid ecosystems, with two species native to the highlands of Eritrea, Ricinus communis and Solanum marginatum, revealed that O. ficus-indica is a weak competitor. The unique ability of O. ficus-indica's fallen cladodes to undergo vegetative growth becomes a fundamental trait contributing to its spread. This growth strategy allows O. ficus-indica to outgrow native species and establish a significant presence. In direct interaction, the competition in aboveground productivity measured by the logarithmic response ratio for O. ficus-indica was 3.4-fold and 5.9-fold higher than for R. communis and S. marginatum, respectively. Belowground, the native R. communis was facilitated (- 1.00 ± 0.69) by O. ficus-indica which itself suffered from high competition. This pattern became even more evident under water shortage, where aboveground competition for S. marginatum decreased 5.7-fold, and for O. ficus-indica, it increased 1.4-fold. Despite being a poor competitor, O. ficus-indica outperformed R. communis and S. marginatum in both aboveground (4.3 and 3.8 times more) and belowground (27 and 2.8 times more) biomass production, respectively. The findings of this study challenge the common interpretation that invasive species are strong competitors and highlight the importance of considering other factors, such as productivity and tolerance limits when assessing the potential impacts of invasive species on semiarid ecosystems.


Assuntos
Ecossistema , Opuntia , Biomassa , Espécies Introduzidas , Biodiversidade , Opuntia/metabolismo
2.
Plants (Basel) ; 12(18)2023 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-37765451

RESUMO

Biological invasions pose global threats to biodiversity and ecosystem functions. Invasive species often display a high degree of phenotypic plasticity, enabling them to adapt to new environments. This study examines plasticity to water stress in native and invasive Opuntia ficus-indica populations, a prevalent invader in arid and semi-arid ecosystems. Through controlled greenhouse experiments, we evaluated three native and nine invasive populations. While all plants survived the dry treatment, natives exhibited lower plasticity to high water availability with only a 36% aboveground biomass increase compared to the invasives with a greater increase of 94%. In terms of belowground biomass, there was no significant response to increased water availability for native populations, but plants from the invasive populations showed a 75% increase from the dry to the wet treatment. Enhanced phenotypic plasticity observed in invasive populations of O. ficus-indica is likely a significant driver of their success and invasiveness across different regions, particularly with a clear environmental preference towards less arid conditions. Climate change is expected to amplify the invasion success due to the expansion of arid areas and desertification. Opuntia ficus-indica adapts to diverse environments, survives dry spells, and grows rapidly in times of high-water supply, making it a candidate for increased invasion potential with climate change.

3.
Mil Med ; 185(9-10): e1590-e1595, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32495838

RESUMO

INTRODUCTION: Despite an increasing number of female service members, incidence rates of gynecologic cancers (other than cervical cancer) have not been previously documented in the U.S. active duty military population. This study sought to determine the incidence rates of all gynecologic, including peritoneal, malignancies in the U.S. Active Duty population compared to the general US population as reported in the Surveillance, Epidemiology, and End Results Program database. MATERIALS AND METHODS: Gynecologic cancers diagnosed in U.S. Active Duty women aged 20-59 between 2004 and 2013 were retrospectively ascertained. Cancer cases were identified in both the Automated Central Tumor Registry and the Military Health System Data Repository. All cases in Automated Central Tumor Registry plus cases recorded in Military Health System Data Repository, but not duplicative of Automated Central Tumor Registry cases, were included. Age-specific and age-adjusted incidence rates were calculated in military and Surveillance, Epidemiology, and End Results cases. RESULTS: In U.S. Active Duty women, 327 incident cases of gynecologic cancer were identified. There were 110 cases of cervical cancer, 40 cases of endometrial cancer, 152 cases of ovarian cancer, and 25 other gynecologic malignancies. Of the 327 cases, 154 were ascertained from the Automated Central Tumor Registry database and the remainder from Military Health System Data Repository claims data. The age-adjusted rate of all gynecologic cancers for U.S. Active Duty women was 49.17 per 105 (95%CI 37.58, 65.12), while the age-adjusted rate for Surveillance, Epidemiology, and End Results -18 was 42.09 per 105 (95%CI 41.83, 42.35). The kappa coefficient assessing the overlap between the data sources was -0.1937. Though insufficient in numbers for statistical analysis, the observed proportion of ovarian to cervical cancer cases in active duty women < 45 years of age was substantially greater than in the general population. CONCLUSIONS: U.S. Active Duty women exhibited a similar age-adjusted rate of gynecologic cancer as the general US population. There was suboptimal overlap between the Automated Central Tumor Registry and Military Health System Data Repository databases, indicating the necessity of using both databases in order to obtain reliable data in the active duty population. This study is the current best estimate of a baseline rate of gynecologic cancer in U.S. active duty military women. This rate might change over time as women's roles and exposures in recent and future military conflicts evolve.


Assuntos
Neoplasias dos Genitais Femininos , Militares , Adulto , Feminino , Neoplasias dos Genitais Femininos/epidemiologia , Humanos , Incidência , Pessoa de Meia-Idade , Sistema de Registros , Estudos Retrospectivos , Estados Unidos/epidemiologia , Adulto Jovem
4.
Zoonoses Public Health ; 67(2): 130-137, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31705635

RESUMO

Neoehrlichia mikurensis is a tick-borne pathogen widespread among ticks and rodents in Europe and Asia. A previous study on Ixodes ricinus ticks in Norway suggested that N. mikurensis was scarce or absent on the south-west coast of Norway, but abundant elsewhere. The aim of this study was to further investigate the prevalence and distribution of N. mikurensis along the western seaboard of Norway in comparison with more eastern and northern areas. The second aim of the study was to examine seasonal variation of the bacterium in one specific location in the south-eastern part of Norway. Questing I. ricinus were collected from 13 locations along the coast of Norway, from Brønnøysund in Nordland County to Spjaerøy in Østfold County. In total, 11,113 nymphs in 1,113 pools and 718 individual adult ticks were analysed for N. mikurensis by real-time PCR. The mean prevalence of N. mikurensis in adult ticks was 7.9% while the estimated pooled prevalence in nymphs was 3.5%. The prevalence ranged from 0% to 25.5%, with the highest prevalence in the southernmost and the northernmost locations. The pathogen was absent, or present only at low prevalence (<5%), at eight locations, all located in the west, from 58.9°N to 64.9°N. The prevalence of N. mikurensis was significantly different between counties (p < .0001). No significant seasonal variation of N. mikurensis prevalence was observed in the period May to October 2015. Our results confirm earlier findings of a low prevalence of N. mikurensis in the western seaboard of Norway.


Assuntos
Anaplasmataceae/classificação , Anaplasmataceae/isolamento & purificação , Ixodes/microbiologia , Animais , Noruega , Estações do Ano
5.
Fed Pract ; 36(4): 170-175, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31138969

RESUMO

Easily implemented ordering practices in the electronic health record increased the rate of guideline-concordant testing, decreased cost, and furthered the goal of high-value medical care.

6.
Int J Pharm ; 529(1-2): 597-607, 2017 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-28713000

RESUMO

A mechanistic particle scale model is proposed for bilayer tablet compaction. Making bilayer tablets involves the application of first layer compaction pressure on the first layer powder and a second layer compaction pressure on entire powder bed. The bonding formed between the first layer and the second layer particles is crucial for the mechanical strength of the bilayer tablet. The bonding and the contact forces between particles of the first layer and second layer are affected by the deformation and rearrangement of particles due to the compaction pressures. Our model takes into consideration the elastic and plastic deformations of the first layer particles due to the first layer compaction pressure, in addition to the mechanical and physical properties of the particles. Using this model, bilayer tablets with layers of the same material and different materials, which are commonly used pharmaceutical powders, are tested. The simulations show that the strength of the layer interface becomes weaker than the strength of the two layers as the first layer compaction pressure is increased. The reduction of strength at the layer interface is related to reduction of the first layer surface roughness. The reduced roughness decreases the available bonding area and hence reduces the mechanical strength at the interface. In addition, the simulations show that at higher first layer compaction pressure the bonding area is significantly less than the total contact area at the layer interface. At the interface itself, there is a non-monotonic relationship between the bonding area and first layer force. The bonding area at the interface first increases and then decreases as the first layer pressure is increased. These results are in agreement with findings of previous experimental studies.


Assuntos
Composição de Medicamentos/métodos , Comprimidos , Pós , Pressão , Resistência à Tração
7.
Phys Rev E ; 94(4-1): 042902, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27841576

RESUMO

Accurate prediction of the time required to heat up granular materials to a target temperature is crucial for several processes. However, we do not have quantitative models to predict the average temperature or the temperature distribution of the particles. Here, we computationally investigate the scaling of heat transfer in granular flows in rotating drums. Based on our simulations, which include a wide range of system and material properties, we identify the appropriate characteristic time that is used to derive equations that predict the particles' average temperature and the particles' temperature distribution.

8.
Int J Pharm ; 503(1-2): 68-77, 2016 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-26902721

RESUMO

The evolution of microstructure during powder compaction process was investigated using a discrete particle modeling, which accounts for particle size distribution and material properties, such as plasticity, elasticity, and inter-particle bonding. The material properties were calibrated based on powder compaction experiments and validated based on tensile strength test experiments for lactose monohydrate and microcrystalline cellulose, which are commonly used excipient in pharmaceutical industry. The probability distribution function and the orientation of contact forces were used to study the evolution of the microstructure during the application of compaction pressure, unloading, and ejection of the compact from the die. The probability distribution function reveals that the compression contact forces increase as the compaction force increases (or the relative density increases), while the maximum value of the tensile contact forces remains the same. During unloading of the compaction pressure, the distribution approaches a normal distribution with a mean value of zero. As the contact forces evolve, the anisotropy of the powder bed also changes. Particularly, during loading, the compression contact forces are aligned along the direction of the compaction pressure, whereas the tensile contact forces are oriented perpendicular to direction of the compaction pressure. After ejection, the contact forces become isotropic.


Assuntos
Modelos Teóricos , Pós/química , Celulose/química , Composição de Medicamentos , Lactose/química , Tamanho da Partícula , Pressão , Resistência à Tração
9.
APMIS ; 123(9): 759-64, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26126504

RESUMO

Tick-borne encephalitis (TBE) is the most important viral tick-borne disease in Europe and can cause severe disease in humans. In Norway, human cases have been reported only from the southern coast. The aim of this study was to investigate the prevalence of tick-borne encephalitis virus (TBEV) in questing Ixodes ricinus ticks from the north-western part of Norway. A total of 4509 ticks were collected by flagging in May and June 2014. A subpopulation of 2220 nymphs and 162 adult ticks were analysed by real-time PCR and positive samples were confirmed by pyrosequencing. The estimated prevalence of TBEV was 3.08% among adult ticks from Sekken in Møre og Romsdal County and 0.41% among nymphs from both Hitra and Frøya in Sør-Trøndelag County. This study indicates that TBEV might be more widespread than the distribution of reported human cases suggests.


Assuntos
Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Encefalite Transmitida por Carrapatos/epidemiologia , Ixodes/virologia , Carrapatos/virologia , Animais , Humanos , Ilhas , Noruega/epidemiologia , Prevalência
10.
J Clin Anesth ; 27(2): 153-8, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25468586

RESUMO

STUDY OBJECTIVE: The aim of this study was to examine the effect of changing head position on the laryngeal view in the same subject. DESIGN: Prospective, randomized, crossover comparison of laryngeal views. SETTING: Operating suite at a university-affiliated, community hospital. PATIENTS: One hundred sixty-seven consenting adult patients scheduled to undergo elective surgery with general anesthesia. INTERVENTIONS: After anesthesia induction and muscle relaxation and the head in extended position, the laryngeal view was graded in 3 different head height positions. A special inflatable pillow was placed under the subject's head before induction and was deflated to produce no head elevation or inflated to produce either 6.0cm (sniffing position), or 10.0cm elevation (elevated sniffing position) in random order. MAIN RESULTS: The incidence of difficult laryngoscopy (grade ≥3) was 8.38% with no head elevation, 2.39% in the sniffing position, and 1.19% in the elevated sniffing position. Head elevation was not associated with a worse grade in any single patient. CONCLUSIONS: Sniffing position improves glottic exposure when the laryngoscopic grade is greater than 1 in the head-flat position. The elevated sniffing position improves the view to a better grade in some patients. Because head elevation was not associated with a worse grade in any subject, the elevated sniffing position should be considered as the initial head position before direct laryngoscopy when a difficult exposure is anticipated.


Assuntos
Movimentos da Cabeça , Laringoscopia/métodos , Laringe/anatomia & histologia , Posicionamento do Paciente/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anestesia Geral/métodos , Estudos Cross-Over , Feminino , Cabeça/anatomia & histologia , Humanos , Intubação Intratraqueal/métodos , Masculino , Pessoa de Meia-Idade , Postura/fisiologia , Estudos Prospectivos , Adulto Jovem
11.
Malar J ; 12: 242, 2013 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-23855778

RESUMO

BACKGROUND: Ethiopia scaled up net distribution markedly starting in 2006. Information on expected net life under field conditions (physical durability and persistence of insecticidal activity) is needed to improve planning for net replacement. Standardization of physical durability assessment methods is lacking. METHODS: Permanet®2.0 long-lasting insecticidal bed nets (LLINs), available for distribution in early 2007, were collected from households at three time intervals. The number, size and location of holes were recorded for 189 nets used for three to six months from nine sites (2007) and 220 nets used for 14 to 20 months from 11 sites (2008). In 2009, a "finger/fist" sizing method classified holes in 200 nets used for 26 to 32 months from ten sites into small (<2 cm), medium (> = 2 to < =10 cm) and large (>10 cm) sizes. A proportionate hole index based on both hole number and area was derived from these size classifications. RESULTS: After three to six months, 54.5% (95% CI 47.1-61.7%) of 189 LLINs had at least one hole 0.5 cm (in the longest axis) or larger; mean holes per net was 4.4 (SD 8.4), median was 1.0 (Inter Quartile Range [IQR] 0-5) and median size was 1 cm (IQR 1-2). At 14 to 20 months, 85.5% (95% CI 80.1-89.8%) of 220 nets had at least one hole with mean 29.1 (SD 50.1) and median 12 (IQR 3-36.5) holes per net, and median size of 1 cm (IQR 1-2). At 26 to 32 months, 92.5% of 200 nets had at least one hole with a mean of 62.2 (SD 205.4) and median of 23 (IQR 6-55.5) holes per net. The mean hole index was 24.3, 169.1 and 352.8 at the three time periods respectively. Repairs were rarely observed. The majority of holes were in the lower half of the net walls. The proportion of nets in 'poor' condition (hole index >300) increased from 0% at three to six months to 30% at 26 to 32 months. CONCLUSIONS: Net damage began quickly: more than half the nets had holes by three to six months of use, with 40% of holes being larger than 2 cm. Holes continued to accumulate until 92.5% of nets had holes by 26 to 32 months of use. An almost complete lack of repairs shows the need for promoting proper use of nets and repairs, to increase LLIN longevity. Using the hole index, almost one third of the nets were classed as unusable and ineffective after two and a half years of potential use.


Assuntos
Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Controle de Mosquitos/instrumentação , Etiópia , Humanos , Malária/prevenção & controle
12.
Phys Rev Lett ; 106(5): 058302, 2011 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-21405443

RESUMO

Models for dense sheared granular materials indicate that their rheological properties depend on particle size, but the representative size for mixtures is not obvious. Here, we computationally study pressure on a boundary due to sheared granular mixtures to determine its dependence on particle size distribution. We find that the pressure does not depend monotonically on average particle size. Instead it has an additional dependence on a measure of the effective free volume per particle we adapt from an expression for packing of monosized particles near the jammed state.

13.
Trop Med Int Health ; 11(6): 824-33, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16772004

RESUMO

OBJECTIVE: This paper describes determinants of insecticide treated net (ITN) ownership and use in malarious areas of Eritrea. With ITN distribution and re-treatment now free for all living in these areas, we examine barriers (other than cost) to access and use of ITNs. We explore the differences between use of an ITN as a proportion of all households in the survey (the roll back malaria indicator), and use of an ITN as a proportion of those households who already own an ITN. METHODS: A modified two-stage cluster design was used to collect data from a sample of households (n = 2341) in the three most malarious administrative zobas (zones or provinces). Logistic regression was used to analyse the data. RESULTS: Our findings suggest environmental heterogeneity among zobas (including program effects specific to each zoba), perception of risk, and proximity to a clinic are important predictors of ITN possession and use. Among households with at least one ITN, 17.0% reported that children under five were not under an ITN the night before the survey, while half of all such households did not have all occupants using them the night before the survey. The number of ITNs, as well as zoba, was also significant determinants of use in these households with at least one ITN. CONCLUSION: Current efforts to disseminate ITNs to vulnerable populations in Eritrea are working, as suggested by high ITN ownership and net-to-person ratios inside households. However, the gap between ITN ownership and use, given ownership, is large, and may represent lost opportunities to prevent infection. Closing this gap requires concerted efforts to change behaviour to ensure that all household members use ITNs as consistently and correctly as possible during and following the rains.


Assuntos
Roupas de Cama, Mesa e Banho/estatística & dados numéricos , Inseticidas/uso terapêutico , Malária/prevenção & controle , Atitude Frente a Saúde , Serviços de Saúde Comunitária , Eritreia/epidemiologia , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Malária/epidemiologia , Propriedade/estatística & dados numéricos , Vigilância da População/métodos , Chuva , Saúde da População Rural , Estações do Ano
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA