183 research outputs found
Violence among foragers: The bioarchaeological record from central California
Spatial and diachronic patterns in skeletal evidence for three forms of violence were evaluated for central California with information from a bioarchaeological database that contains information on 16,820 burials from 329 sites. The most abundant form of violence was sharp force/projectile trauma (462/6278, 7.4%), followed by blunt force craniofacial trauma (264/6202, 4.3%) and trophy-taking/dismemberment (87/12,603, 0.7%). Signs of violence were concentrated in the area with the highest ethnographic population densities (Sacramento River), but also in the southern San Francisco Bay area which seems to have been a contested interface zone between established residents and incoming migrants. Sharp force/projectile trauma was also high in the Sierra Nevada following introduction of the bow and arrow, and violence in general was more common among males, although there is less of a sex-difference among individuals with blunt force craniofacial injuries in central California relative to southern California, suggesting greater participation by females in this form of violence as attested by historic eyewitness accounts. Temporal patterning shows two episodes of elevated violence: the Early Middle Period (500 cal B.C.–cal A.D. 420) when trophytaking/dismemberment peaked, and the Protohistoric/Historic Period (cal A.D. 1720–1899) marked by high levels of blunt force craniofacial and projectile trauma. The Protohistoric/Historic peak, preceded by the appearance of the bow and arrow ca. A.D.1000–1200 and an associated upturn in projectile violence, is attributed to the arrival of Europeans into southwestern North America 250 years before their permanent settlement in California ca. A.D. 1769
Continuous high-resolution midlatitude-belt simulations for July–August 2013 with WRF
Increasing computational resources and the demands of impact
modelers, stake holders, and society envision seasonal and climate simulations
with the convection-permitting resolution. So far such a resolution is only
achieved with a limited-area model whose results are impacted by zonal and
meridional boundaries. Here, we present the setup of a latitude-belt domain
that reduces disturbances originating from the western and eastern boundaries
and therefore allows for studying the impact of model resolution and physical
parameterization. The Weather Research and Forecasting (WRF) model coupled to
the NOAH land–surface model was operated during July and August 2013 at two
different horizontal resolutions, namely 0.03 (HIRES) and
0.12° (LOWRES). Both simulations were forced by the European Centre for Medium-Range Weather Forecasts (ECMWF) operational
analysis data at the northern and southern domain boundaries, and the
high-resolution Operational Sea Surface Temperature and Sea Ice Analysis
(OSTIA) data at the sea surface.The simulations are compared to the operational ECMWF analysis for the
representation of large-scale features. To analyze the simulated
precipitation, the operational ECMWF forecast, the CPC MORPHing (CMORPH), and
the ENSEMBLES gridded observation precipitation data set (E-OBS) were used as
references.Analyzing pressure, geopotential height, wind, and temperature fields as well
as precipitation revealed (1)Â a benefit from the higher resolution concerning
the reduction of monthly biases, root mean square error, and an improved
Pearson skill score, and (2)Â deficiencies in the physical parameterizations leading
to notable biases in distinct regions like the polar Atlantic for the LOWRES
simulation, the North Pacific, and Inner Mongolia for both resolutions.In summary, the application of a latitude belt on a convection-permitting
resolution shows promising results that are beneficial for future seasonal
forecasting
Comparative genomic and metabolomic analysis of Termitomyces species provides insights into the terpenome of the fungal cultivar and the characteristic odor of the fungus garden of Macrotermes natalensis termites
Macrotermitinae termites have domesticated fungi of the genus Termitomyces as food for their colony, analogously to human farmers growing crops. Termites propagate the fungus by continuously blending foraged and predigested plant material with fungal mycelium and spores (fungus comb) within designated subterranean chambers. To test the hypothesis that the obligate fungal symbiont emits specific volatiles (odor) to orchestrate its life cycle and symbiotic relations, we determined the typical volatile emission of fungus comb biomass and Termitomyces nodules, revealing α-pinene, camphene, and d-limonene as the most abundant terpenes. Genome mining of Termitomyces followed by gene expression studies and phylogenetic analysis of putative enzymes related to secondary metabolite production encoded by the genomes uncovered a conserved and specific biosynthetic repertoire across strains. Finally, we proved by heterologous expression and in vitro enzymatic assays that a highly expressed gene sequence encodes a rare bifunctional mono-/sesquiterpene cyclase able to produce the abundant comb volatiles camphene and d-limonene. IMPORTANCE The symbiosis between macrotermitinae termites and Termitomyces is obligate for both partners and is one of the most important contributors to biomass conversion in the Old World tropic’s ecosystems. To date, research efforts have dominantly focused on acquiring a better understanding of the degradative capabilities of Termitomyces to sustain the obligate nutritional symbiosis, but our knowledge of the small-molecule repertoire of the fungal cultivar mediating interspecies and interkingdom interactions has remained fragmented. Our omics-driven chemical, genomic, and phylogenetic study provides new insights into the volatilome and biosynthetic capabilities of the evolutionarily conserved fungal genus Termitomyces, which allows matching metabolites to genes and enzymes and, thus, opens a new source of unique and rare enzymatic transformations
Observational operators for dual polarimetric radars in variational data assimilation systems (PolRad VAR v1.0)
We implemented two observational
operators for dual polarimetric radars in two variational data assimilation
systems: WRF Var, the Weather Research and Forecasting Model variational data
assimilation system, and NHM-4DVAR, the nonhydrostatic variational data
assimilation system for the Japan Meteorological Agency nonhydrostatic model.
The operators consist of a space interpolator, two types of variable
converters, and their linearized and transposed (adjoint) operators. The
space interpolator takes account of the effects of radar-beam broadening in
both the vertical and horizontal directions and climatological beam bending.
The first variable converter emulates polarimetric parameters with model
prognostic variables and includes attenuation effects, and the second one
derives rainwater content from the observed polarimetric parameter (specific
differential phase). We developed linearized and adjoint operators for the
space interpolator and variable converters and then assessed whether the
linearity of the linearized operators and the accuracy of the adjoint
operators were good enough for implementation in variational systems. The
results of a simple assimilation experiment showed good agreement between
assimilation results and observations with respect to reflectivity and
specific differential phase but not with respect to differential
reflectivity
Meteorological, impact and climate perspectives of the 29 June 2017 heavy precipitation event in the Berlin metropolitan area
Extreme precipitation is a weather phenomenon with tremendous damaging potential for property and human life. As the intensity and frequency of such events is projected to increase in a warming climate, there is an urgent need to advance the existing knowledge on extreme precipitation processes, statistics and impacts across scales. To this end, a working group within the Germany-based project, ClimXtreme, has been established to carry out multidisciplinary analyses of high-impact events. In this work, we provide a comprehensive assessment of the 29 June 2017 heavy precipitation event (HPE) affecting the Berlin metropolitan region (Germany), from the meteorological, impacts and climate perspectives, including climate change attribution. Our analysis showed that this event occurred under the influence of a mid-tropospheric trough over western Europe and two shortwave surface lows over Britain and Poland (Rasmund and Rasmund II), inducing relevant low-level wind convergence along the German–Polish border. Over 11 000 convective cells were triggered, starting early morning 29 June, displacing northwards slowly under the influence of a weak tropospheric flow (10 m s at 500 hPa). The quasi-stationary situation led to totals up to 196 mm d, making this event the 29 June most severe in the 1951–2021 climatology, ranked by means of a precipitation-based index. Regarding impacts, it incurred the largest insured losses in the period 2002 to 2017 (EUR 60 million) in the greater Berlin area. We provide further insights on flood attributes (inundation, depth, duration) based on a unique household-level survey data set. The major moisture source for this event was the Alpine–Slovenian region (63 % of identified sources) due to recycling of precipitation falling over that region 1 d earlier. Implementing three different generalised extreme value (GEV) models, we quantified the return periods for this case to be above 100 years for daily aggregated precipitation, and up to 100 and 10 years for 8 and 1 h aggregations, respectively. The conditional attribution demonstrated that warming since the pre-industrial era caused a small but significant increase of 4 % in total precipitation and 10 % for extreme intensities. The possibility that not just greenhouse-gas-induced warming, but also anthropogenic aerosols affected the intensity of precipitation is investigated through aerosol sensitivity experiments. Our multi-disciplinary approach allowed us to relate interconnected aspects of extreme precipitation. For instance, the link between the unique meteorological conditions of this case and its very large return periods, or the extent to which it is attributable to already-observed anthropogenic climate change
Meteorological, impact and climate perspectives of the 29 June 2017 heavy precipitation event in the Berlin metropolitan area
Extreme precipitation is a weather phenomenon with tremendous damaging potential for property and human life. As the intensity and frequency of such events is projected to increase in a warming climate, there is an urgent need to advance the existing knowledge on extreme precipitation processes, statistics and impacts across scales. To this end, a working group within the Germany-based project, ClimXtreme, has been established to carry out multidisciplinary analyses of high-impact events. In this work, we provide a comprehensive assessment of the 29 June 2017 heavy precipitation event (HPE) affecting the Berlin metropolitan region (Germany), from the meteorological, impacts and climate perspectives, including climate change attribution. Our analysis showed that this event occurred under the influence of a mid-tropospheric trough over western Europe and two shortwave surface lows over Britain and Poland (Rasmund and Rasmund II), inducing relevant low-level wind convergence along the German–Polish border. Over 11 000 convective cells were triggered, starting early morning 29 June, displacing northwards slowly under the influence of a weak tropospheric flow (10 m s−1 at 500 hPa). The quasi-stationary situation led to totals up to 196 mm d−1, making this event the 29 June most severe in the 1951–2021 climatology, ranked by means of a precipitation-based index. Regarding impacts, it incurred the largest insured losses in the period 2002 to 2017 (EUR 60 million) in the greater Berlin area. We provide further insights on flood attributes (inundation, depth, duration) based on a unique household-level survey data set. The major moisture source for this event was the Alpine–Slovenian region (63 % of identified sources) due to recycling of precipitation falling over that region 1 d earlier. Implementing three different generalised extreme value (GEV) models, we quantified the return periods for this case to be above 100 years for daily aggregated precipitation, and up to 100 and 10 years for 8 and 1 h aggregations, respectively. The conditional attribution demonstrated that warming since the pre-industrial era caused a small but significant increase of 4 % in total precipitation and 10 % for extreme intensities. The possibility that not just greenhouse-gas-induced warming, but also anthropogenic aerosols affected the intensity of precipitation is investigated through aerosol sensitivity experiments. Our multi-disciplinary approach allowed us to relate interconnected aspects of extreme precipitation. For instance, the link between the unique meteorological conditions of this case and its very large return periods, or the extent to which it is attributable to already-observed anthropogenic climate change.</p
Tumour Cell Heterogeneity.
The population of cells that make up a cancer are manifestly heterogeneous at the genetic, epigenetic, and phenotypic levels. In this mini-review, we summarise the extent of intra-tumour heterogeneity (ITH) across human malignancies, review the mechanisms that are responsible for generating and maintaining ITH, and discuss the ramifications and opportunities that ITH presents for cancer prognostication and treatment
Aberrant epithelial GREM1 expression initiates colonic tumorigenesis from cells outside the stem cell niche
Hereditary mixed polyposis syndrome (HMPS) is characterized by the development of mixed-morphology colorectal tumors and is caused by a 40-kb genetic duplication that results in aberrant epithelial expression of the gene encoding mesenchymal bone morphogenetic protein antagonist, GREM1. Here we use HMPS tissue and a mouse model of the disease to show that epithelial GREM1 disrupts homeostatic intestinal morphogen gradients, altering cell fate that is normally determined by position along the vertical epithelial axis. This promotes the persistence and/or reacquisition of stem cell properties in Lgr5-negative progenitor cells that have exited the stem cell niche. These cells form ectopic crypts, proliferate, accumulate somatic mutations and can initiate intestinal neoplasia, indicating that the crypt base stem cell is not the sole cell of origin of colorectal cancer. Furthermore, we show that epithelial expression of GREM1 also occurs in traditional serrated adenomas, sporadic premalignant lesions with a hitherto unknown pathogenesis, and these lesions can be considered the sporadic equivalents of HMPS polyps
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