The Small Magellanic Cloud (SMC) is the second-largest satellite galaxy of the Milky Way and is only 60 kpc away. As a nearby, massive, and dense object with relatively low astrophysical backgrounds, ...it is a natural target for dark matter indirect detection searches. In this work, we use six years of Pass 8 data from the Fermi Large Area Telescope to search for gamma-ray signals of dark matter annihilation in the SMC. Using data-driven fits to the gamma-ray backgrounds, and a combination of N-body simulations and direct measurements of rotation curves to estimate the SMC DM density profile, we found that the SMC was well described by standard astrophysical sources, and no signal from dark matter annihilation was detected. We set conservative upper limits on the dark matter annihilation cross section. These constraints are in agreement with stronger constraints set by searches in the Large Magellanic Cloud and approach the canonical thermal relic cross section at dark matter masses lower than 10 GeV in the bb and tau super(+)tau super(-) channels.
Cullin-RING ligases (CRL) are ubiquitin E3 enzymes that bind substrates through variable substrate receptor proteins and are activated by attachment of the ubiquitin-like protein NEDD8 to the cullin ...subunit. DCNs are NEDD8 E3 ligases that promote neddylation. Mammalian cells express five DCN-like (DCNL) proteins but little is known about their specific functions or interaction partners. We found that DCNLs form stable stoichiometric complexes with CAND1 and cullins that can only be neddylated in the presence of a substrate adaptor. These CAND-cullin-DCNL complexes might represent 'reserve' CRLs that can be rapidly activated when needed. We further found that all DCNLs interact with most cullin subtypes, but that they are probably responsible for the neddylation of different subpopulations of any given cullin. This is consistent with the fact that the subcellular localization of DCNLs in tissue culture cells differs and that they show unique tissue-specific expression patterns in mice. Thus, the specificity between DCNL-type NEDD8 E3 enzymes and their cullin substrates is only apparent in well-defined physiological contexts and related to their subcellular distribution and restricted expression.
Slope units are terrain partitions bounded by drainage and divide lines. In landslide modeling, including susceptibility modeling and event-specific modeling of landslide occurrence, slope units ...provide several advantages over gridded units, such as better capturing terrain geometry, improved incorporation of geospatial landslide-occurrence data in different formats (e.g., point and polygon), and better accommodating the varying data accuracy and precision in landslide inventories. However, the use of slope units in regional (> 100 km2) landslide studies remains limited due, in part, to the large computational costs and/or poor reproducibility with current delineation methods. We introduce a computationally efficient algorithm for the parameter-free delineation of slope units that leverages tools from within TauDEM and GRASS, using an R interface. The algorithm uses geomorphic laws to define the appropriate scaling of the slope units representative of hillslope processes, avoiding the often ambiguous determination of slope unit size. We then demonstrate how slope units enable more robust regional-scale landslide susceptibility and event-specific landslide occurrence maps.
•We synthesize a formative opportunity attractiveness construct from the extant opportunity evaluation literature.•Opportunity attractiveness consists of gain estimation, loss estimation, and ...perceived feasibility.•We develop scales for the dimensions of opportunity attractiveness and provide evidence for their reliability and validity.•Gain estimation, loss estimation, and perceived feasibility are predicted by relevant antecedents.•The dimensions combine to form opportunity attractiveness which predicts pursuit intentions and opportunity preference.
Quantifying ecological responses to river flow regimes is a key scientific approach underpinning many environmental flow (e‐flow) strategies. Incorporating habitat‐scale influences (e.g. substrate ...composition and organic matter cover) within e‐flow frameworks has the potential to provide a broader understanding of the causal mechanisms shaping instream communities, which may be used to guide river management strategies.
In this study, we examined invertebrate communities inhabiting three distinct habitat groups (HGs—defined by coarse substrates, fine sediments, and the fine‐leaved macrophyte Ranunculus sp.) across four rivers (each comprising two study sites) within a single catchment. We tested the structural and functional responses of communities inhabiting different HGs to three sets of flow‐related characteristics: (1) antecedent hydrological (discharge—m3/s) variability; (2) antecedent anthropogenic flow alterations (percentage of discharge added to or removed from the river by human activity); and (3) proximal hydraulic conditions (characterised by the Froude number). The former two were derived from groundwater model daily time series in the year prior to the collection of each invertebrate sample, while the latter was collected at the point of sampling.
While significant effects of hydrological and anthropogenic flow alteration indices were detected, Froude number exerted the greatest statistical influence on invertebrate communities. This highlights that habitat‐scale hydraulic conditions to which biota are exposed at the time of sampling are a key influence on the structure and function of invertebrate communities.
Mixed‐effect models testing invertebrate community responses to flow‐related characteristics, most notably Froude number, improved when a HG interaction term was incorporated. This highlights that different mineralogical and organic habitat patches mediate ecological responses to hydraulic conditions. This can be attributed to HGs supporting distinct taxonomic and functional compositions and/or providing unique ecological functions (e.g. flow refuges), which alter how instream communities respond to hydraulic conditions.
While the individual importance of both flow and small‐scale habitat effects on instream biota has been widely reported, this study provides rare evidence on how their interactive effects have a significant influence on riverine ecosystems. These findings suggest that river management strategies and e‐flow frameworks should not only aim to create a mosaic of riverine habitats that support ecosystem functioning, but also consider the management of local hydraulic conditions within habitat patches to support specific taxonomic and functional compositions.
New methods are needed to rapidly identify malaria parasites in blood smears. The coupling of a Focal Plane Array (FPA) infrared microscope system to a synchrotron light source at IRENI enables rapid ...molecular imaging at high spatial resolution. The technique, in combination with hyper-spectral processing, enables imaging and diagnosis of early stage malaria parasites at the single cell level in a blood smear. The method relies on the detection of distinct lipid signatures associated with the different stages of the malaria parasite and utilises resonant Mie extended multiplicative scatter correction to pre-process the spectra followed by full bandwidth image deconvolution to resolve the single cells. This work demonstrates the potential of focal plane technology to diagnose single cells in a blood smear. Brighter laboratory based infrared sources, optical refinements and higher sensitive detectors will soon see the emergence of focal plane array imaging in the clinical environment.
FTIR focal plane array imaging can be applied to diagnose single malaria infected cells in a thick film blood smear.
Patients with hepatocellular carcinoma (HCC) frequently have multiple anatomically distinct tumors. In these patients, multifocal HCC could represent intrahepatic metastases (IMs) of a single cancer ...or multicentric carcinogenesis (MC) with multiple independent neoplasms. To determine the frequency and clinical implications of these 2 possibilities, we performed histological and molecular analysis of 70 anatomically distinct HCCs from 24 patients. We assayed mutations in the TERT promoter region by Sanger sequencing and used next-generation sequencing to analyze the entire coding regions of 7 well-characterized HCC driver genes—based on shared or discordant mutations in these genes, we classified the HCCs in each patient as IM, MC, or indeterminate. Mutations in the TERT promoter were the most common alteration in our cohort, present in 71% of tumors analyzed. Mutations in the remaining genes occurred in less than 20% of analyzed tumors. We were able to determine the relatedness in 58% of the patients analyzed: MC occurred in 41% of patients, with 33% with exclusively MC and 8% with both MC and IM. IM occurred exclusively in 17% of patients, whereas the remainder were indeterminate. This study highlights the utility of molecular analyses to determine relatedness in multifocal HCC; however, targeted sequencing can only resolve this distinction in approximately 60% of patients with multifocal HCC.
•The origin of multifocal HCC can be determined with targeted sequencing.•Multicentric carcinogenesis and intrahepatic metastasis occur in 41% and 25%.•Targeted sequencing can resolve this distinction in approximately 60% of patients.
There is growing recognition of the essential services provided to humanity by functionally intact ecosystems. Freshwater ecosystems are found throughout agricultural and urban landscapes and provide ...a wide range of ecosystem services, but globally they are also amongst the most vulnerable. In particular, ponds (lentic waters typically less than 2 ha), provide natural flood management, sequester carbon and hold significant cultural value. However, to inform their management it is important to understand (1) how functional diversity varies in response to disturbance and (2) the link between biodiversity conservation and ecosystem function. In this study, a meta‐analysis of seven separate pond studies from across England and Wales was carried out to explore the effect of urban and agricultural land‐use gradients, shading, emergent vegetation, surface area and pH upon groups of functionally similar members of the macroinvertebrate fauna. Functional effect groups were first identified by carrying out a hierarchical cluster analysis using body size, voltinism and feeding habits (18 categories) that are closely related to biogeochemical processes (e.g. nutrient and carbon recycling). Secondly, the influence of the gradients upon effect group membership (functional redundancy—FR) and the breadth of traits available to aid ecosystem recovery (response diversity) was assessed using species counts and functional dispersion (FDis) using 12 response traits. The effect of land‐use gradients was unpredictable, whilst there was a negative response in both FR and FDis to shading and positive responses to increases in emergent vegetation cover and surface area. An inconsistent association between FDis and FR suggested that arguments for taxonomic biodiversity conservation to augment ecosystem functioning are too simplistic. Thus, a deeper understanding of the response of functional diversity to disturbance could have greater impact with decision‐makers who may relate better to the loss of ecosystem function in response to environmental degradation than species loss alone.
Whilst land‐use change has been well documented to negatively impact freshwater habitats and their biodiversity, the functional response of these communities is little researched. We asked, how does the number of species sharing similar functional traits (redundancy), and their respective response trait diversity change along land‐use and local environment gradients? An inconsistent effect of land‐use upon functional diversity was found suggesting context‐dependency. Local environmental variables were more consistent and significant in their influence. A partial disconnect was observed between functional redundancy and response diversity, with implications for biological conservation.
The growing research interest and uptake of layered nanomaterials for real-world applications require efficient, reliable, high-quality characterization methods. Liquid-exfoliated graphene has ...well-established Raman spectroscopic metrics for mean size and thickness. In association with the mapping process described here, distributions of nanosheet properties can be reconstructed. Here, we develop new, robust metrics for length and layer number of MoS2 nanosheets, developed using resonant Raman spectroscopy, applicable to both liquid- and mechanically-exfoliated MoS2. The use of metricized Raman mapping analysis, here demonstrated for graphene and MoS2, facilitates the standardization of characterization, allowing the correlation of size- and thickness-sensitive applications’ performance with materials properties.
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