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1.
Biometrics ; 80(2)2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38591365

RESUMO

A spatial sampling design determines where sample locations are placed in a study area so that population parameters can be estimated with relatively high precision. If the response variable has spatial trends, spatially balanced or well-spread designs give precise results for commonly used estimators. This article proposes a new method that draws well-spread samples over arbitrary auxiliary spaces and can be used for master sampling applications. All we require is a measure of the distance between population units. Numerical results show that the method generates well-spread samples and compares favorably with existing designs. We provide an example application using several auxiliary variables to estimate total aboveground biomass over a large study area in Eastern Amazonia, Brazil. Multipurpose surveys are also considered, where the totals of aboveground biomass, primary production, and clay content (3 responses) are estimated from a single well-spread sample over the auxiliary space.


Assuntos
Tamanho da Amostra , Inquéritos e Questionários
2.
Angew Chem Int Ed Engl ; 62(21): e202301356, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36944060

RESUMO

We report the synthesis and characterization of a novel type of nanohoop, consisting of a cycloparaphenylene derivative incorporating a curved heptagon-containing π-extended polycyclic aromatic hydrocarbon (PAH) unit. We demonstrate that this new macrocycle behaves as a supramolecular receptor of curved π-systems such as fullerenes C60 and C70 , with remarkably large binding constants (ca. 107  M-1 ), as estimated by fluorescence measurements. Nanosecond and femtosecond spectroscopic analysis show that these host-guest complexes are capable of quasi-instantaneous charge separation upon photoexcitation, due to the ultrafast charge transfer from the macrocycle to the complexed fullerene. These results demonstrate saddle-shaped PAHs with dibenzocycloheptatrienone motifs as structural components for new macrocycles displaying molecular receptor abilities and versatile photochemical responses with promising electron-donor properties in host-guest complexes.

3.
J Neurooncol ; 149(3): 489-498, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33025283

RESUMO

PURPOSE: Despite the large clinical interest in mindfulness, little is known about its effects in patients with brain tumours. Novel delivery methods such as App based Mindfulness training (AMT) may assist in the delivery of mindfulness treatment to this group of patients. METHODS: We aimed to determine the feasibility of administering an 8-week mindfulness treatment by AMT in patients operated on for brain tumours in a publically funded hospital. As a secondary aim we collected preliminary data regarding changes in self-reported psychological distress, quality of life and mindfulness capacity. RESULTS: Uptake was of 40 potentially eligible participants. Of the 20 entering the study, only 10 completed the 8-week post group assessment and only 3 completed the follow-up assessment. There was a positive direction of pre-post change in almost all completers with statistically significant improvement in several mindfulness scales and illness-related quality of life however there was a deterioration in the social/family quality of life domain. The significant variability in individual usage of the AMT appeared to be related more to individual differences rather than tumour histology, progression or treatment. The treatment was well received by those completing the study. CONCLUSIONS: Recruitment and retention feasibility issues were identified. Promising preliminary change and treatment satisfaction scores however suggest that further research with the AMT is warranted. Reduced assessment burden and more regular engagement during treatment is recommended to enhance retention. Large sample sizes however will be needed to address the heterogeneity of this group.


Assuntos
Neoplasias Encefálicas/terapia , Atenção Plena/métodos , Qualidade de Vida , Adolescente , Adulto , Idoso , Neoplasias Encefálicas/psicologia , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Adulto Jovem
4.
Proc Natl Acad Sci U S A ; 114(15): 3885-3890, 2017 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-28289202

RESUMO

Increased regulation of chemical pesticides and rapid evolution of pesticide resistance have increased calls for sustainable pest management. Biological control offers sustainable pest suppression, partly because evolution of resistance to predators and parasitoids is prevented by several factors (e.g., spatial or temporal refuges from attacks, reciprocal evolution by control agents, and contrasting selection pressures from other enemy species). However, evolution of resistance may become more probable as agricultural intensification reduces the availability of refuges and diversity of enemy species, or if control agents have genetic barriers to evolution. Here we use 21 y of field data from 196 sites across New Zealand to show that parasitism of a key pasture pest (Listronotus bonariensis; Argentine stem weevil) by an introduced parasitoid (Microctonus hyperodae) was initially nationally successful but then declined by 44% (leading to pasture damage of c. 160 million New Zealand dollars per annum). This decline was not attributable to parasitoid numbers released, elevation, or local climatic variables at sample locations. Rather, in all locations the decline began 7 y (14 host generations) following parasitoid introduction, despite releases being staggered across locations in different years. Finally, we demonstrate experimentally that declining parasitism rates occurred in ryegrass Lolium perenne, which is grown nationwide in high-intensity was significantly less than in adjacent plots of a less-common pasture grass (Lolium multiflorum), indicating that resistance to parasitism is host plant-dependent. We conclude that low plant and enemy biodiversity in intensive large-scale agriculture may facilitate the evolution of host resistance by pests and threaten the long-term viability of biological control.


Assuntos
Agricultura/métodos , Controle Biológico de Vetores/métodos , Animais , Interações Hospedeiro-Parasita , Himenópteros , Espécies Introduzidas , Nova Zelândia , Gorgulhos
5.
Materials (Basel) ; 16(2)2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36676571

RESUMO

Nanographenes (NGs) have been attracting widespread interest since they combine peculiar properties of graphene with molecular features, such as bright visible photoluminescence. However, our understanding of the fundamental properties of NGs is still hampered by the high degree of heterogeneity usually characterizing most of these materials. In this context, NGs obtained by atomically precise synthesis routes represent optimal benchmarks to unambiguously relate their properties to well-defined structures. Here we investigate in deep detail the optical response of three curved hexa-peri-hexabenzocoronene (HBC) derivatives obtained by atomically precise synthesis routes. They are constituted by the same graphenic core, characterized by the presence of a heptagon ring determining a saddle distortion of their sp2 network, and differ from each other for slightly different edge functionalization. The quite similar structure allows for performing a direct comparison of their spectroscopic features, from steady-state down to the femtosecond scale, and precisely disentangling the role played by the different edge chemistry.

6.
Sci Rep ; 13(1): 3870, 2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36890142

RESUMO

The attention of the scientific community, policymakers, and public opinion on the Medicanes has recently grown because of their increase in intensity and harmful potential. Although Medicanes may be influenced by pre-existing upper-ocean conditions, uncertainties remain about how such weather extremes influence ocean circulation. This work examines a condition that has been never described before in the Mediterranean, which involves the interplay between an atmospheric cyclone (Medicane Apollo-October 2021) and a cyclonic gyre located in the western Ionian Sea. During the event, the temperature in the core of the cold gyre dropped dramatically, due to a local maximum in the wind-stress curl, Ekman pumping, and relative vorticity. Cooling and vertical mixing of the surface layer combined with upwelling in the subsurface layer caused a shoaling of the Mixed Layer Depth, halocline, and nutricline. The resulting biogeochemical impacts included an increase in oxygen solubility, chlorophyll concentration, productivity at the surface, and decreases in the subsurface layer. The presence of a cold gyre along Apollo's trajectory leads to a different ocean response from that observed with previous Medicanes, endorsing the efficiency of a multi-platform observation system integrated into an operational model for future mitigation of weather-related damages.

8.
ISRN Pediatr ; 2011: 296418, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22389774

RESUMO

Aim. To explore the potential usefulness of the mean, standard deviation (SD), and coefficient of variation (CV = SD/mean) of oximeter oxygen saturations in the clinical care of preterm babies. Methods. This was an exploratory investigation involving 31 preterm babies at 36 weeks postmenstrual age. All babies were healthy, but two were considered to be clinically unstable and required greater attention. Each baby's oxygen saturations were recorded using an oximeter and summarized by the mean, SD, and CV. The potential usefulness of each measure was assessed by its ability to distinguish the two unstable babies from the others. This was achieved using box plots and hierarchical clustering together with the Calinski-Harabasz (CH) index to quantify clustering performance (higher CH index indicates stronger clustering outcome). Results. The box plots flagged both unstable babies as outliers and none of the other babies. Successful clustering of the stable and unstable babies was achieved using the CV (CH = 72.8) and SD (CH = 63.3) but not with the mean. Conclusion. Taking the box plots and clustering results together, it seems plausible that variability might be more effective than mean level for detecting instability in oxygen saturation in preterm babies and that the combination of variability and level through the CV might be even better.

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