Search results for "Heterogeneity."
showing 10 items of 388 documents
Interaction of climate change with effects of conspecific and heterospecific density on reproduction
2020
We studied the relationship between temperature and the coexistence of great tit Parus major and blue tit Cyanistes caeruleus, breeding in 75 study plots across Europe and North Africa. We expected an advance in laying date and a reduction in clutch size during warmer springs as a general response to climate warming and a delay in laying date and a reduction in clutch size during warmer winters due to density-dependent effects. As expected, as spring temperature increases laying date advances and as winter temperature increases clutch size is reduced in both species. Density of great tit affected the relationship between winter temperature and laying date in great and blue tit. Specifically…
Geochemical constraints on basalt petrogenesis in the Strait of Sicily Rift Zone (Italy): Insights into the importance of short lengthscale mantle he…
2020
Igneous activity from the late Miocene to historic time (most recently 1891 CE) in the Strait of Sicily has created two volcanic islands (Pantelleria and Linosa) and several seamounts. These volcanoes are dominated by transitional (ol + hy-normative) to alkaline (ne-normative) basaltic lavas and scoriae; volcanic felsic rocks (peralkaline trachyte-rhyolite) crop out only on Pantelleria. Although most likely erupted through continental crust, basalts demonstrate no evidence of crustal contamination and are geochemically similar to oceanic island basalts (OIB). Despite their isotopic similarities, there are considerable compositional differences with respect to major and trace element geochem…
Management diversity begets biodiversity in production forest landscapes
2022
How to manage forest for biodiversity conservation is an ongoing debate. We argue that maximizing biodiversity in managed forest landscapes requires a diversity of forest management regimes in space and time. This will generate high levels of habitat heterogeneity at a landscape scale, which in turn will support various groups of forest species. Based on concepts from landscape ecology, we formulate five hypotheses on how management diversity, i.e. combining various management approaches can benefit overall biodiversity across a production forest landscape. First, management diversity will increase habitat diversity and, therefore, beta diversity (the habitat diversity hypothesis). Second, …
Effect of endothelial cell heterogeneity on nanoparticle uptake.
2020
Endothelial cells exhibit distinct properties in morphology and functions in different organs that can be exploited for nanomedicine targeting. In this work, endothelial cells from different organs, i.e. brain, lung, liver, and kidney, were exposed to plain, carboxylated, and amino-modified silica. As expected, different protein coronas were formed on the different nanoparticle types and these changed when foetal bovine serum (FBS) or human serum were used. Uptake efficiencies differed strongly in the different endothelia, confirming that the cells retained some of their organ-specific differences. However, all endothelia showed higher uptake for the amino-modified silica in FBS, but, inter…
Chronological Age Interacts with the Circadian Melatonin Receptor 1B Gene Variation, Determining Fasting Glucose Concentrations in Mediterranean Popu…
2020
Gene-age interactions have not been systematically investigated on metabolic phenotypes and this modulation will be key for a better understanding of the temporal regulation in nutrigenomics. Taking into account that aging is typically associated with both impairment of the circadian system and a decrease in melatonin secretion, we focused on the melatonin receptor 1B (MTNR1B)-rs10830963 C>
Extropy: Complementary Dual of Entropy
2015
This article provides a completion to theories of information based on entropy, resolving a longstanding question in its axiomatization as proposed by Shannon and pursued by Jaynes. We show that Shannon's entropy function has a complementary dual function which we call "extropy." The entropy and the extropy of a binary distribution are identical. However, the measure bifurcates into a pair of distinct measures for any quantity that is not merely an event indicator. As with entropy, the maximum extropy distribution is also the uniform distribution, and both measures are invariant with respect to permutations of their mass functions. However, they behave quite differently in their assessments…
Genetic and pharmacological modulation of DNA mismatch repair heterogeneous tumors promotes immune surveillance.
2023
Patients affected by colorectal cancer (CRC) with DNA mismatch repair deficiency (MMRd), often respond to immune checkpoint blockade therapies, while those with mismatch repair-proficient (MMRp) tumors generally do not. Interestingly, a subset of MMRp CRCs contains variable fractions of MMRd cells, but it is unknown how their presence impacts immune surveillance. We asked whether modulation of the MMRd fraction in MMR heterogeneous tumors acts as an endogenous cancer vaccine by promoting immune surveillance. To test this hypothesis, we use isogenic MMRp (Mlh1+/+) and MMRd (Mlh1-/-) mouse CRC cells. MMRp/MMRd cells mixed at different ratios are injected in immunocompetent mice and tumor reje…
Precision sampling fuels precision oncology: an evolutionary perspective.
2021
Intratumor heterogeneity (ITH) develops in malignant tumors. Precision sampling that captures this tumor variability is essential for the implementation of precision oncology. We highlight the necessity to update current sampling protocols and implement a strategy to ensure ITH detection and characterization. A cost-effective strategy for such sampling has been modeled in clear cell renal cell carcinoma (CCRCC).
Cancer stem cell definitions and terminology:the devil is in the details
2012
The cancer stem cell (CSC) concept has important therapeutic implications, but its investigation has been hampered both by a lack of consistency in the terms used for these cells and by how they are defined. Evidence of their heterogeneous origins, frequencies and their genomic, as well as their phenotypic and functional, properties has added to the confusion and has fuelled new ideas and controversies. Participants in The Year 2011 Working Conference on CSCs met to review these issues and to propose a conceptual and practical framework for CSC terminology. More precise reporting of the parameters that are used to identify CSCs and to attribute responses to them is also recommended as key t…
Comparison of vaccine strains and the virus causing the 1986 foot-and-mouth disease outbreak in Spain: epizootiological analysis
1990
RNAs of the most recent foot-and-mouth disease virus isolated in Spain (A5Sp86) during the 1986 outbreak, and of the three vaccine strains in use at that time in that country, have been compared. Although these viruses are serologically indistinguishable, differences have been found among them by T1 fingerprinting. This genetic heterogeneity affects the immunogenic VP1 gene, with amino acid changes located at the carboxyterminal end of the molecule. VP1-coding sequences obtained have been compared with those previously reported for European A5 FMDVs and it has been possible to trace their phylogenetic origin. The most parsimonious evolutionary tree obtained shows that the viruses analyzed a…