The spread of modern humans across the globe has led to genetic adaptations to diverse local environments. Recent developments in genomic technologies, statistical analyses, and expanded sampled ...populations have led to improved identification and fine-mapping of genetic variants associated with adaptations to regional living conditions and dietary practices. Ongoing efforts in sequencing genomes of indigenous populations, accompanied by the growing availability of "-omics" and ancient DNA data, promises a new era in our understanding of recent human evolution and the origins of variable traits and disease risks.
It is not clear to what extent starvation-induced autophagy affects the proteome on a global scale and whether it is selective. In this study, we report based on quantitative proteomics that cells ...during the first 4 h of acute starvation elicit lysosomal degradation of up to 2-3% of the proteome. The most significant changes are caused by an immediate autophagic response elicited by shortage of amino acids but executed independently of mechanistic target of rapamycin and macroautophagy. Intriguingly, the autophagy receptors p62/SQSTM1, NBR1, TAX1BP1, NDP52, and NCOA4 are among the most efficiently degraded substrates. Already 1 h after induction of starvation, they are rapidly degraded by a process that selectively delivers autophagy receptors to vesicles inside late endosomes/multivesicular bodies depending on the endosomal sorting complex required for transport III (ESCRT-III). Our data support a model in which amino acid deprivation elicits endocytosis of specific membrane receptors, induction of macroautophagy, and rapid degradation of autophagy receptors by endosomal microautophagy.
Hybrid nanowires combining semiconductor and superconductor materials appear well suited for the creation, detection, and control of Majorana bound states (MBSs). We demonstrate the emergence of MBSs ...from coalescing Andreev bound states (ABSs) in a hybrid InAs nanowire with epitaxial Al, using a quantum dot at the end of the nanowire as a spectrometer. Electrostatic gating tuned the nanowire density to a regime of one or a few ABSs. In an applied axial magnetic field, a topological phase emerges in which ABSs move to zero energy and remain there, forming MBSs. We observed hybridization of the MBS with the end-dot bound state, which is in agreement with a numerical model. The ABS/MBS spectra provide parameters that are useful for understanding topological superconductivity in this system.
This paper presents finite‐sample efficiency bounds for the core econometric problem of estimation of linear regression coefficients. We show that the classical Gauss–Markov theorem can be restated ...omitting the unnatural restriction to linear estimators, without adding any extra conditions. Our results are lower bounds on the variances of unbiased estimators. These lower bounds correspond to the variances of the the least squares estimator and the generalized least squares estimator, depending on the assumption on the error covariances. These results show that we can drop the label “linear estimator” from the pedagogy of the Gauss–Markov theorem. Instead of referring to these estimators as BLUE, they can legitimately be called BUE (best unbiased estimators).
There is widespread concern about the quality, reproducibility and translatability of studies involving research animals. Although there are a number of reporting guidelines available, there is very ...little overarching guidance on how to plan animal experiments, despite the fact that this is the logical place to start ensuring quality. In this paper we present the PREPARE guidelines: Planning Research and Experimental Procedures on Animals: Recommendations for Excellence. PREPARE covers the three broad areas which determine the quality of the preparation for animal studies: formulation, dialogue between scientists and the animal facility, and quality control of the various components in the study. Some topics overlap and the PREPARE checklist should be adapted to suit specific needs, for example in field research. Advice on use of the checklist is available on the Norecopa website, with links to guidelines for animal research and testing, at https://norecopa.no/PREPARE.
We investigate effects of quasiparticle poisoning in a Majorana island with strong tunnel coupling to normal-metal leads. In addition to the main Coulomb blockade diamonds, "shadow" diamonds appear, ...shifted by 1e in gate voltage, consistent with transport through an excited (poisoned) state of the island. Comparison to a simple model yields an estimate of parity lifetime for the strongly coupled island (∼1 μs) and sets a bound for a weakly coupled island (>10 μs). Fluctuations in the gate-voltage spacing of Coulomb peaks at high field, reflecting Majorana hybridization, are enhanced by the reduced lever arm at strong coupling. When converted from gate voltage to energy units, fluctuations are consistent with previous measurements.
Threshold regression methods are developed for non-dynamic panels with individual-specific fixed effects. Least squares estimation of the threshold and regression slopes is proposed using ...fixed-effects transformations. A non-standard asymptotic theory of inference is developed which allows construction of confidence intervals and testing of hypotheses. The methods are applied to a 15-year sample of 565 US firms to test whether financial constraints affect investment decisions.
Africa is the origin of modern humans within the past 300 thousand years. To infer the complex demographic history of African populations and adaptation to diverse environments, we sequenced the ...genomes of 92 individuals from 44 indigenous African populations.
Genetic structure analyses indicate that among Africans, genetic ancestry is largely partitioned by geography and language, though we observe mixed ancestry in many individuals, consistent with both short- and long-range migration events followed by admixture. Phylogenetic analysis indicates that the San genetic lineage is basal to all modern human lineages. The San and Niger-Congo, Afroasiatic, and Nilo-Saharan lineages were substantially diverged by 160 kya (thousand years ago). In contrast, the San and Central African rainforest hunter-gatherer (CRHG), Hadza hunter-gatherer, and Sandawe hunter-gatherer lineages were diverged by ~ 120-100 kya. Niger-Congo, Nilo-Saharan, and Afroasiatic lineages diverged more recently by ~ 54-16 kya. Eastern and western CRHG lineages diverged by ~ 50-31 kya, and the western CRHG lineages diverged by ~ 18-12 kya. The San and CRHG populations maintained the largest effective population size compared to other populations prior to 60 kya. Further, we observed signatures of positive selection at genes involved in muscle development, bone synthesis, reproduction, immune function, energy metabolism, and cell signaling, which may contribute to local adaptation of African populations.
We observe high levels of genomic variation between ethnically diverse Africans which is largely correlated with geography and language. Our study indicates ancient population substructure and local adaptation of Africans.
Abnormal glucose metabolism is central to neurodegeneration, and considerable evidence suggests that abnormalities in key enzymes of the tricarboxylic acid (TCA) cycle underlie the metabolic ...deficits. Significant recent advances in the role of metabolism in cancer provide new insight that facilitates our understanding of the role of metabolism in neurodegeneration. Research indicates that the rate-limiting step of the TCA cycle, the α-ketoglutarate dehydrogenase complex (KGDHC) and its substrate alpha ketoglutarate (KG), serve as a signaling hub that regulates multiple cellular processes: (1) is the rate-limiting step of the TCA cycle, (2) is sensitive to reactive oxygen species (ROS) and produces ROS, (3) determines whether KG is used for energy or synthesis of compounds to support growth, (4) regulates the cellular responses to hypoxia, (5) controls the post-translational modification of hundreds of cell proteins in the mitochondria, cytosol, and nucleus through succinylation, (6) controls critical aspects of transcription, (7) modulates protein signaling within cells, and (8) modulates cellular calcium. The primary focus of this review is to understand how reductions in KGDHC are translated to pathologically important changes that underlie both neurodegeneration and cancer. An understanding of each role is necessary to develop new therapeutic strategies to treat neurodegenerative disease.
Objective
To develop recommendations for prevention and treatment of glucocorticoid‐induced osteoporosis (GIOP).
Methods
We conducted a systematic review to synthesize the evidence for the benefits ...and harms of GIOP prevention and treatment options. The Grading of Recommendations Assessment, Development and Evaluation methodology was used to rate the quality of evidence. We used a group consensus process to determine the final recommendations and grade their strength. The guideline addresses initial assessment and reassessment in patients beginning or continuing long‐term (≥3 months) glucocorticoid (GC) treatment, as well as the relative benefits and harms of lifestyle modification and of calcium, vitamin D, bisphosphonate, raloxifene, teriparatide, and denosumab treatment in the general adult population receiving long‐term GC treatment, as well as in special populations of long‐term GC users.
Results
Because of limited evidence regarding the benefits and harms of interventions in GC users, most recommendations in this guideline are conditional (uncertain balance between benefits and harms). Recommendations include treating only with calcium and vitamin D in adults at low fracture risk, treating with calcium and vitamin D plus an additional osteoporosis medication (oral bisphosphonate preferred) in adults at moderate‐to‐high fracture risk, continuing calcium plus vitamin D but switching from an oral bisphosphonate to another antifracture medication in adults in whom oral bisphosphonate treatment is not appropriate, and continuing oral bisphosphonate treatment or switching to another antifracture medication in adults who complete a planned oral bisphosphonate regimen but continue to receive GC treatment. Recommendations for special populations, including children, people with organ transplants, women of childbearing potential, and people receiving very high‐dose GC treatment, are also made.
Conclusion
This guideline provides direction for clinicians and patients making treatment decisions. Clinicians and patients should use a shared decision‐making process that accounts for patients’ values, preferences, and comorbidities. These recommendations should not be used to limit or deny access to therapies.
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