Latin Americans are highly heterogeneous regarding the type of Native American ancestry. Consideration of specific associations with common diseases may lead to substantial advances in unraveling of ...disease etiology and disease prevention. Here we investigate possible associations between the type of Native American ancestry and leading causes of death. After an aggregate-data study based on genome-wide genotype data from 1805 admixed Chileans and 639,789 deaths, we validate an identified association with gallbladder cancer relying on individual data from 64 gallbladder cancer patients, with and without a family history, and 170 healthy controls. Native American proportions were markedly underestimated when the two main types of Native American ancestry in Chile, originated from the Mapuche and Aymara indigenous peoples, were combined together. Consideration of the type of Native American ancestry was crucial to identify disease associations. Native American ancestry showed no association with gallbladder cancer mortality (P = 0.26). By contrast, each 1% increase in the Mapuche proportion represented a 3.7% increased mortality risk by gallbladder cancer (95%CI 3.1-4.3%, P = 6×10-27). Individual-data results and extensive sensitivity analyses confirmed the association between Mapuche ancestry and gallbladder cancer. Increasing Mapuche proportions were also associated with an increased mortality due to asthma and, interestingly, with a decreased mortality by diabetes. The mortality due to skin, bladder, larynx, bronchus and lung cancers increased with increasing Aymara proportions. Described methods should be considered in future studies on human population genetics and human health. Complementary individual-based studies are needed to apportion the genetic and non-genetic components of associations identified relying on aggregate-data.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Acetogens play a key role in anaerobic degradation of organic material and in maintaining biogas process efficiency. Profiling this community and its temporal changes can help evaluate process ...stability and function, especially under disturbance/stress conditions, and avoid complete process failure. The formyltetrahydrofolate synthetase (FTHFS) gene can be used as a marker for acetogenic community profiling in diverse environments. In this study, we developed a new high-throughput FTHFS gene sequencing method for acetogenic community profiling and compared it with conventional terminal restriction fragment length polymorphism of the FTHFS gene, 16S rRNA gene-based profiling of the whole bacterial community, and indirect analysis via 16S rRNA profiling of the FTHFS gene-harbouring community. Analyses and method comparisons were made using samples from two laboratory-scale biogas processes, one operated under stable control and one exposed to controlled overloading disturbance. Comparative analysis revealed satisfactory detection of the bacterial community and its changes for all methods, but with some differences in resolution and taxonomic identification. FTHFS gene sequencing was found to be the most suitable and reliable method to study acetogenic communities. These results pave the way for community profiling in various biogas processes and in other environments where the dynamics of acetogenic bacteria have not been well studied.
A brain atlas of the carrion crow (Corvus corone) Kersten, Ylva; Friedrich‐Müller, Bettina; Nieder, Andreas
Journal of comparative neurology,
December 2022, 2022-12-00, 20221201, Letnik:
530, Številka:
17
Journal Article
Recenzirano
Odprti dostop
Corvidae, passerine songbirds such as jays, crows, and ravens known as corvids, have become model systems for the study of avian cognition. The superior cognitive capabilities of corvids mainly ...emerge from a disproportionally large telencephalon found in these species. However, a systematic mapping of the neuroanatomy of the corvid brain, and the telencephalon in particular, is lacking so far. Here, we present a brain atlas of the carrion crow, Corvus corone, with special emphasis on the telencephalic pallium. We applied four staining techniques to brain slices (Nissl, myelin, combination of Nissl and myelin, and tyrosine hydroxylase targeting catecholaminergic neurons). This allowed us to identify brain nuclei throughout the brain and delineate the known pallial subdivisions termed hyperpallium, entopallium, mesopallium, nidopallium, arcopallium, and hippocampal complex. The extent of these subdivisions and brain nuclei are described according to stereotaxic coordinates. In addition, 3D depictions of pallial regions were reconstructed from these slices. While the overall organization of the carrion crow's brain matches other songbird brains, the relative proportions and expansions of associative pallial areas differ considerably in agreement with enhanced cognitive skills found in corvids. The presented global organization of the crow brain in stereotaxic coordinates will help to guide future neurobiological studies in corvids.
Kersten et al. present a brain atlas of the carrion crow, Corvus corone, a corvid songbird. Based on different staining techniques applied to brain slices and 3D reconstructions, the global organization of the crow brain is shown in stereotaxic coordinates. This atlas will help to compare avian species and guide future neurobiological studies of corvids.
In this paper, we analyze how previously failed entrepreneurs fare with their current venture in terms of survival compared with novices. While previous studies have focused on the superior learning ...effects of failure experience, we point to the selection process that takes place before failed entrepreneurs become business owners again. One potential driver of this process is entrepreneurial talent. We find that failed entrepreneurs are less likely to survive with their current venture. This result persists for several subgroups of entrepreneurs, if we consider the number of past failure events, or if we control for the inclination of entrepreneurs to pursue high-risk projects. Overall, our results are consistent with the hypothesis that previously failed entrepreneurs are those with below-average entrepreneurial talent.
Plain English Summary
It is often argued that failure is a particularly rich source of learning. It is reasonable to expect, therefore, that entrepreneurs who have failed once will do better the second time than those who try for the first time. In this paper, we compare the survival chances of businesses of entrepreneurs who failed with their ventures in the past with those of first-time entrepreneurs (novices). We find that entrepreneurs whose previous business has failed keep new businesses running for less time than novices do. This result remains even after a series of robustness checks in which we look at different subgroups of entrepreneurs. Thus, we cannot find evidence for the assumption that previous entrepreneurial failure is particularly valuable for entrepreneurs. To explain our result, we point to the selection process that takes place before we see failed entrepreneurs another time in business. Some of the failed entrepreneurs decide to start again, while others do not, and it is likely that this process is not random. A potential driver of this process is entrepreneurial talent and our results are consistent with the hypothesis that failed entrepreneurs are those with below-average entrepreneurial talent. Although this does not imply that all entrepreneurs who failed have poor talent, a general second-chance policy cannot be easily justified. A targeted search and support of high-profile entrepreneurs among the failed might be more sensible.
The song system of songbirds (oscines) is one of the best studied neuroethological model systems. So far, it has been treated as a relatively constrained sensorimotor system. Songbirds such as crows, ...however, are also known for their capability to cognitively control their audio‐vocal system. Yet, the neuroanatomy of the corvid song system has never been explored systematically. We aim to close this scientific gap by presenting a stereotactic investigation of the extended song system of the carrion crow (Corvus corone), an oscine songbird of the corvid family that has become an interesting model system for cognitive neuroscience. In order to identify and delineate the song nuclei, the ascending auditory nuclei, and the descending vocal‐motor nuclei, four stains were applied. In addition to the classical Nissl‐, myelin‐, and a combination of Nissl‐and‐myelin staining, staining for tyrosine hydroxylase was used to reveal the distribution of catecholaminergic neurons (dopaminergic, noradrenergic, and adrenergic) in the song system. We show that the crow brain contains the important song‐related nuclei, including auditory input and motor output structures, and map them throughout the brain. Fiber‐stained sections reveal putative connection patterns between the crow's song nuclei comparable to other songbirds.
The song system of songbirds (oscines) is one of the best explored neuroethological model systems. The study presents a histological investigation of the nuclei of the extended song system of the carrion crow (Corvus corone), a songbird of the corvid family that has become an interesting model system for cognitive neuroscience.
Methane (CH
) is produced as an end product from feed fermentation in the rumen. Yield of CH
varies between individuals despite identical feeding conditions. To get a better understanding of factors ...behind the individual variation, 73 dairy cows given the same feed but differing in CH
emissions were investigated with focus on fiber digestion, fermentation end products and bacterial and archaeal composition. In total 21 cows (12 Holstein, 9 Swedish Red) identified as persistent low, medium or high CH
emitters over a 3 month period were furthermore chosen for analysis of microbial community structure in rumen fluid. This was assessed by sequencing the V4 region of 16S rRNA gene and by quantitative qPCR of targeted
groups. The results showed a positive correlation between low CH
emitters and higher abundance of
clade. Principal coordinate analysis (PCoA) on operational taxonomic unit (OTU) level of bacteria showed two distinct clusters (
< 0.01) that were related to CH
production. One cluster was associated with low CH
production (referred to as cluster L) whereas the other cluster was associated with high CH
production (cluster H) and the medium emitters occurred in both clusters. The differences between clusters were primarily linked to differential abundances of certain OTUs belonging to
. Moreover, several OTUs belonging to the family Succinivibrionaceae were dominant in samples belonging to cluster L. Fermentation pattern of volatile fatty acids showed that proportion of propionate was higher in cluster L, while proportion of butyrate was higher in cluster H. No difference was found in milk production or organic matter digestibility between cows. Cows in cluster L had lower CH
/kg energy corrected milk (ECM) compared to cows in cluster H, 8.3 compared to 9.7 g CH
/kg ECM, showing that low CH
cows utilized the feed more efficient for milk production which might indicate a more efficient microbial population or host genetic differences that is reflected in bacterial and archaeal (or methanogens) populations.
Summary
Biogas production from nitrogen‐rich feedstock results in release of ammonia (NH3), causing inhibition of the microbial process. The reported threshold ammonia value for stable biogas ...production varies greatly between studies, probably because of differences in operating conditions. Moreover, it is often difficult to separate the effect of ammonia inhibition from that of organic loading rate (OLR), as these two factors are often interrelated. This study attempted to distinguish the effects of ammonia and OLR by analysis of two laboratory‐scale biogas reactors operating with thin stillage and subjected to an increase in free ammonia (from 0.30 to 1.1 g L−1) either by addition of an external nitrogen source (urea) or by increasing the OLR (3.2–6.0 g volatile solids L−1 d−1). The results showed that ammonia concentration was detrimental for process performance, with the threshold for stability in both processes identified as being about 1 g NH3‐N L−1, irrespective of OLR. Analysis of the methanogenic community showed limited differences between the two reactors on order level and a clear increase in the abundance of Methanomicrobiales, particularly Methanoculleus sp., in response to increasing ammonia concentration. Further comprehensive molecular analysis revealed that diverse Methanoculleus species dominated in the reactors at a given ammonia level at different OLR. The acetogenic community was clearly affected by both ammonia concentration and OLR, suggesting that the volatile fatty acid load in relation to the higher OLR was important for the dynamics of this community.
This study attempted to distinguish the effects of ammonia and OLR by analysis of two laboratory‐scale biogas reactors operating with thin stillage and subjected to an increase in free ammonia (from 0.30 to 1.1 g/L) either by addition of an external nitrogen source (urea) or by increasing the OLR (3.2‐6.0 g volatile solids/L d). The results showed that ammonia concentration was detrimental for process performance, with the threshold for stability in both processes identified as being about 1 g NH3‐N/L, irrespective of OLR.
•10 out of 13 randomly selected biogas plants showed syntrophic acetate oxidation (SAO).•High SAO bacteria (SAOB) abundance despite differences in operation parameters.•Stable levels of SAOB under ...variable operating conditions.•SAOB correlated positively with low abundance of aceticlastic methanogens.•The thermophilic SAOB T. phaeum correlated with high ammonia levels.
The extent of syntrophic acetate oxidation (SAO) and the levels of known SAO bacteria and acetate- and hydrogen-consuming methanogens were determined in sludge from 13 commercial biogas production plants. Results from these measurements were statistically related to the prevailing operating conditions, through partial least squares (PLS) analysis. This revealed that high abundance of microorganisms involved in SAO was positively correlated with relatively low abundance of aceticlastic methanogens and high concentrations of free ammonia (>160mg/L) and volatile fatty acids (VFA). Temperature was identified as another influencing factor for the population structure of the syntrophic acetate oxidising bacteria (SAOB). Overall, there was a high abundance of SAOB in the different digesters despite differences in their operating parameters, indicating that SAOB are an enduring and important component of biogas-producing consortia.
Carotenoids and squalene are important terpenes that are applied in a wide range of products in foods and cosmetics. Thraustochytrids might be used as alternative production organisms to improve ...production processes, but the taxon is rarely studied. A screening of 62 strains of thraustochytrids
for their potential to produce carotenoids and squalene was performed. A phylogenetic tree was built based on 18S rRNA gene sequences for taxonomic classification, revealing eight different clades of thraustochytrids. Design of experiments (DoE) and growth models identified high amounts of glucose (up to 60 g/L) and yeast extract (up to 15 g/L) as important factors for most of the strains. Squalene and carotenoid production was studied by UHPLC-PDA-MS measurements. Cluster analysis of the carotenoid composition partially mirrored the phylogenetic results, indicating a possible use for chemotaxonomy. Strains in five clades produced carotenoids. Squalene was found in all analyzed strains. Carotenoid and squalene synthesis was dependent on the strain, medium composition and solidity. Strains related to
and
sp. are promising candidates for carotenoid synthesis. Strains closely related to
might be suitable for squalene production.
might be a good compromise for the production of both molecule groups.
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