A combination of scanning transmission electron microscopy, electron energy loss spectroscopy, and ab initio calculations reveal striking electronic structure differences between two distinct single ...substitutional Si defect geometries in graphene. Optimised acquisition conditions allow for exceptional signal-to-noise levels in the spectroscopic data. The near-edge fine structure can be compared with great accuracy to simulations and reveal either an sp3-like configuration for a trivalent Si or a more complicated hybridized structure for a tetravalent Si impurity.
The mosquito Ae. albopictus is usually adapted to the peri-domestic environment and typically breeds outdoors. However, we observed its larvae in most containers within homes in northern peninsular ...Malaysia. To anticipate the epidemiological implications of this indoor-breeding, we assessed some fitness traits affecting vectorial capacity during colonization process. Specifically, we examined whether Ae. albopictus exhibits increased survival, gonotrophic activity and fecundity due to the potential increase in blood feeding opportunities.
In a series of experiments involving outdoors and indoors breeding populations, we found that Ae. albopictus lives longer in the indoor environment. We also observed increased nighttime biting activity and lifetime fecundity in indoor/domestic adapted females, although they were similar to recently colonized females in body size.
Taken together these data suggest that accommodation of Ae. albopictus to indoor/domestic environment may increase its lifespan, blood feeding success, nuisance and thus vectorial capacity (both in terms of increased vector-host contacts and vector population density). These changes in the breeding behavior of Ae. albopictus, a potential vector of several human pathogens including dengue viruses, require special attention.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Summary
1. There has recently been increasing interest in patterns of beta diversity but we still lack a comprehensive understanding of these patterns in various regions (e.g. the tropics), ...ecosystems (e.g. streams) and organism groups (e.g. invertebrates).
2. Our aim was to investigate the patterns of beta diversity of stream macroinvertebrates in relation to key environmental (i.e. stream size, pH and habitat degradation) and geographical variables (i.e. latitude, longitude, altitude) in a tropical region. We surveyed a total of 8–10 riffle sites in each of 34 streams (altogether 337 riffle sites were sampled) in Peninsular Malaysia to examine variation in macroinvertebrate community composition at within‐stream and among‐stream scales.
3. Based on test of homogeneity of dispersion, we found that the streams studied differed significantly in within‐stream variation in community composition (i.e. among‐site variation of within stream beta diversity). The patterns were similar based on Bray–Curtis coefficient on abundance data, Sorensen coefficient on presence–absence data and Simpson coefficient on presence–absence data. We also found that within‐stream beta diversity was significantly related to stream size, pH and latitude, with each of these variables individually accounting for around 20% of the variation in beta diversity in simple regressions, while the total variation explained by the three significant variables amounted to around 50% in multiple regressions. By contrast, habitat degradation, longitude and altitude were not significantly related to beta diversity. We also found that the factor drainage basin accounted for much of the variation in beta diversity in general linear models, suppressing the effects of environmental variables.
4. We concluded that within‐stream beta diversity is mainly related to a combination of the identity of a drainage basin and stream environmental factors. Our findings provide important background for stream environmental assessment and conservation planning by emphasising that (i) macroinvertebrate communities within streams are not homogeneous, but show considerable beta diversity, (ii) streams differ in their degree of within‐stream beta diversity, (iii) stream size and water pH should be considered in applied contexts related to within‐stream beta diversity and (iv) historical effects may be different in different drainage basins and may affect present‐day patterns of within‐stream beta diversity.
CNT/crystalline Fe nanocomposites (see Figure) have excellent microwave‐absorption characteristics. This absorption property is shown to result from the confinement of crystalline Fe in carbon ...nanoshells, deriving mainly from magnetic rather than electric effects—the complex permittivity and permeability depend both on the shape and phase of the CNT/Fe nanocapsulates.
A combination of scanning transmission electron microscopy, electron energy loss spectroscopy, and ab initio calculations is used to describe the electronic structure modifications incurred by ...free-standing graphene through two types of single-atom doping. The N K and C K electron energy loss transitions show the presence of π* bonding states, which are highly localized around the N dopant. In contrast, the B K transition of a single B dopant atom shows an unusual broad asymmetric peak which is the result of delocalized π* states away from the B dopant. The asymmetry of the B K toward higher energies is attributed to highly localized σ* antibonding states. These experimental observations are then interpreted as direct fingerprints of the expected p- and n-type behavior of graphene doped in this fashion, through careful comparison with density functional theory calculations.
The contribution of RNA processing to tumorigenesis is understudied. Here, we report that the human RNA debranching enzyme (hDBR1), when inappropriately regulated, induces oncogenesis by causing RNA ...processing defects, for example, splicing defects. We found that wild-type p53 and hypoxia-inducible factor 1 co-regulate hDBR1 expression, and insufficient hDBR1 leads to a higher rate of exon skipping. Transcriptomic sequencing confirmed the effect of hDBR1 on RNA splicing, and metabolite profiling supported the observation that neoplasm is triggered by a decrease in hDBR1 expression both in vitro and in vivo. Most importantly, when modulating the expression of hDBR1, which was found to be generally low in malignant human tissues, higher expression of hDBR1 only affected exon-skipping activity in malignant cells. Together, our findings demonstrate previously unrecognized regulation and functions of hDBR1, with immediate clinical implications regarding the regulation of hDBR1 as an effective strategy for combating human cancer.
Remote sensing images (RSIs) often possess obvious background noises, exhibit a multi‐scale phenomenon, and are characterized by complex scenes with ground objects in diversely spatial distribution ...pattern, bringing challenges to the corresponding semantic segmentation. CNN‐based methods can hardly address the diverse spatial distributions of ground objects, especially their compositional relationships, while Vision Transformers (ViTs) introduce background noises and have a quadratic time complexity due to dense global matrix multiplications. In this paper, we introduce Adaptive Pattern Matching (APM), a lightweight method for long‐range adaptive weight aggregation. Our APM obtains a set of pixels belonging to the same spatial distribution pattern of each pixel, and calculates the adaptive weights according to their compositional relationships. In addition, we design a tiny U‐shaped network using the APM as a module to address the large variance of scales of ground objects in RSIs. This network is embedded after each stage in a backbone network to establish a Multi‐stage U‐shaped Adaptive Pattern Matching Network (MAPMaN), for nested multi‐scale modeling of ground objects towards semantic segmentation of RSIs. Experiments on three datasets demonstrate that our MAPMaN can outperform the state‐of‐the‐art methods in common metrics. The code can be available at https://github.com/INiid/MAPMaN.
Theoretical research on the two-dimensional crystal structure of hexagonal boron nitride (h-BN) has suggested that the physical properties of h-BN can be tailored for a wealth of applications by ...controlling the atomic structure of the membrane edges. Unexplored for h-BN, however, is the possibility that small additional edge-atom distortions could have electronic structure implications critically important to nanoengineering efforts. Here we demonstrate, using a combination of analytical scanning transmission electron microscopy and density functional theory, that covalent interlayer bonds form spontaneously at the edges of a h-BN bilayer, resulting in subangstrom distortions of the edge atomic structure. Orbital maps calculated in 3D around the closed edge reveal that the out-of-plane bonds retain a strong π(*) character. We show that this closed edge reconstruction, strikingly different from the equivalent case for graphene, helps the material recover its bulklike insulating behavior and thus largely negates the predicted metallic character of open edges.
Larvae of
Aedes albopictus
Skuse typically inhabit natural and artificial containers. Since these larval habitats are replenished by rainfall,
Ae. albopictus
may experience increased loss of immature ...stages in areas with high levels of rainfall. In this study, we investigated the effects of rainfall and container water level on population density, and oviposition activity of
Ae. albopictus
. In field and laboratory experiments, we found that rainfall resulted in the flushing of breeding habitats. Excess rain negatively impacted larval and pupal retention, especially in small habitats. When filled with water to overflowing, container habitats were significantly repellent to ovipositing females. Taken together, these data suggest that rainfall triggers population loss of
Ae. albopictus
and related species through a direct detrimental effect (flushing out) and an indirect effect (ovipositional repellency).
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