Second-order continuous phase transitions are characterized by symmetry breaking with order parameters. Topological orders of electrons, characterized by the topological index defined in momentum ...space, provide a distinct perspective for phase transitions, which are categorized as quantum phase transitions not being accompanied by symmetry breaking. However, there are still limited observations of counterparts in real space. Here we show a real-space topological phase transition in a chiral magnet MnGe, hosting a periodic array of hedgehog and antihedgehog topological spin singularities. This transition is driven by the pair annihilation of the hedgehogs and antihedgehogs acting as monopoles and antimonopoles of the emergent electromagnetic field. Observed anomalies in the magnetoresistivity and phonon softening are consistent with the theoretical prediction of critical phenomena associated with enhanced fluctuations of emergent field near the transition. This finding reveals a vital role of topology of the spins in strongly correlated systems.
Prevotella copri is a common human gut microbe that has been both positively and negatively associated with host health. In a cross-continent meta-analysis exploiting >6,500 metagenomes, we obtained ...>1,000 genomes and explored the genetic and population structure of P. copri. P. copri encompasses four distinct clades (>10% inter-clade genetic divergence) that we propose constitute the P. copri complex, and all clades were confirmed by isolate sequencing. These clades are nearly ubiquitous and co-present in non-Westernized populations. Genomic analysis showed substantial functional diversity in the complex with notable differences in carbohydrate metabolism, suggesting that multi-generational dietary modifications may be driving reduced prevalence in Westernized populations. Analysis of ancient metagenomes highlighted patterns of P. copri presence consistent with modern non-Westernized populations and a clade delineation time pre-dating human migratory waves out of Africa. These findings reveal that P. copri exhibits a high diversity that is underrepresented in Western-lifestyle populations.
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•P. copri is not a monotypic species but composed of four distinct clades•The P. copri complex is more prevalent in populations with non-Westernized lifestyles•P. copri clades are frequently co-present within non-Westernized individuals•Ancient stool samples suggest Westernization leads to P. copri underrepresentation
Tett et al. find that the intestinal microbe Prevotella copri encompasses four distinct clades constituting the P. copri complex. The complex is prevalent in non-Westernized populations where co-presence of all clades is commonly observed within individuals. Analysis of ancient stool samples supports Westernization as contributing to reduced P. copri prevalence.
Stress vulnerability is a critical factor for the development of trauma‐related disorders; however, its biological underpinnings are not clear. We demonstrated that dysfunctions in the X‐linked ...epigenetic factor methyl‐CpG binding protein 2 (MeCP2) provide trauma vulnerability in male mice. Given the prominent role of sex in stress outcomes, we explored the effects of MeCP2 hypofunctionality in females. Female mice carrying truncated MeCP2 (heterozygous and homozygous) and wild type controls (wt) were tested for fear memory. Stress‐induced corticosterone release and brain expression of hypothalamic‐pituitary‐adrenal (HPA) axis regulatory genes were also evaluated in wt and mutant mice of both sexes. Although heterozygous females displayed a normal stress‐related behavioural profile, homozygous mice showed enhanced memory recall for the threatening context compared to wt, thus recapitulating the phenotype previously evidenced in hemizygous males. Interestingly, MeCP2 truncation abolished the sex differences in stress‐induced corticosterone release, which was found increased in mutant males, whereas blunted in mutant females in a zygosity‐independent manner. Although heterozygous mice did not differ from controls, homozygous females and hemizygous males showed increased hypotalamic Crh and Avp mRNAs and a differentially altered expression of Fkbp5 in cortical areas. Present results demonstrate that in female mice carrying truncated MeCP2, altered stress responsivity is driven by homozygosity, whereas heterozygosity does not lead to maladaptive stress outcomes. MeCP2 dysfunctions thus provide stress vulnerability in mice with sex‐ and zygosity‐dependent outcomes.
Zygosity for a truncating mutation at the X‐linked MeCP2 gene and sex differentially contribute to the onset of stress vulnerability in transgenic mice. Zygosity is crucial in rising contextual fear and hypotalamic HPA axis‐regulatory genes expression (Crh and Avp) compared to wt, while sex primarily modulates the detrimental consequences of MeCP2 hypofunctionality on HPA axis reactivity. Sex and zygosity together influence cortical expression of the HPA axis negative feedback regulator Fkbp5.
The waste-to-energy (WTE) incinerator plant located in the Turin area (Italy) started to recover energy from the combustion of municipal solid waste in 2013. A health surveillance program was ...implemented to evaluate the potential health effects on the population living near the plant. This program included a longitudinal biomonitoring to evaluate temporal changes of some environmental pollutants, including polycyclic aromatic hydrocarbons (PAHs), in residents living in areas near the Turin incinerator (exposed group, E) compared to those observed in subjects living far from the plant (not exposed group, NE). Ten monohydroxy-PAHs (OH-PAHs), consisting in the principal metabolites of naphthalene, fluorine, phenanthrene, and pyrene, were analyzed in urines collected from the E and NE subjects after one (T1) and three years (T2) of plant activity and compared with those determined in the same cohort established before the plant start-up (T0). Spearman correlation analysis was undertaken to explore possible associations between OH-PAHs and personal characteristics, lifestyle variables, and dietary habits. A linear mixed model (LMM) approach was applied to determine temporal trends of OH-PAHs observed in the E and NE subjects and to evaluate possible differences in trend between the two groups. Temporal trends of OH-PAHs determined by LMM analysis demonstrated that, at all times, the E group had concentrations lower than those assessed in the NE group, all other conditions being equal. Moreover, no increase in OH-PAH concentrations was observed at T1 and T2 either in E or in NE group. Significant positive correlations were found between all OH-PAHs and smoking habits. Regarding variables associated to outdoor PAH exposure, residence near high traffic roads and daily time in traffic road was positively correlated with 1-hydroxynaphthalene and 1-hydroxypyrene, respectively. In conclusion, no impact of the WTE plant on exposure to PAHs was observed on the population living near the plant.
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•Human exposure to waste incinerator emissions is of great concern.•No impact of the WTE plant was observed on human exposure to PAHs.•OH-PAH levels did not increase after one and three years of incinerator activity.•Temporal trends of OH-PAH levels did not differ among exposed and not-exposed group.
Let
R
be a prime ring of characteristic different from 2 with extended centroid
C
,
n
≥
1
a fixed positive integer,
F
,
G
:
R
→
R
two non-zero generalized skew derivations of
R
.
If
(
F
(
x
)
x
)
n
∈
...C
for all
x
∈
R
, then the following hold:
if
F
is an inner generalized skew derivation, then either
R
⊆
M
2
(
C
)
or
R
is commutative;
if
F
is not an inner generalized skew derivation, then
R
is commutative.
If
F
(
x
)
x
,
G
(
y
)
y
n
=
0
for all
x
,
y
∈
R
, then
R
is commutative unless when
c
h
a
r
(
R
)
=
p
>
0
,
G
is an inner generalized skew derivation and
R
⊆
M
2
(
C
)
.
In September 2013 a waste-to-energy (WTE) incinerator located in the Turin area (Piedmont, Northern Italy) started to produce energy by the incineration of municipal solid wastes. The plant, one of ...the largest WTE incinerator in Europe, burns up to 490,000 tons of waste per year. A health surveillance program was implemented in order to evaluate the potential health effects on the population living near the plant. This program included a biomonitoring study aimed at assessing levels of several environmental contaminants including, among others, PCDDs, PCDFs, and PCBs. Before the WTE incinerator start-up (T0), a group of 85 subjects (41 “exposed” and 44 “not exposed” subjects) was randomly selected for enrollment by the local health units among individuals aged 36–50 years who had been living in the same area for at least five years prior to the study. Subjects were balanced by exposure area, sex and five-year age classes. As from the study design, the same cohort was re-evaluated after three years of incinerator activity (T2). A parallel study was conducted on a group of 12 farmers living and/or working in farms located in an area in the range of 5 km around the incinerator. Results of this study did not evidence any impact of the WTE plant on human exposure to PCDDs, PCDFs, and PCBs. In fact, no significant differences were found in the concentrations of PCDDs + PCDFs, DL-PCBs, and NDL-PCBs measured in the population group residing near the plant after three years of activity (T2) with respect to the control group. A significant decrease of serum concentrations of all the analytes was observed at T2 in both groups compared to T0. Serum concentrations of PCDDs, PCDFs, and PCBs in the group of farmers were higher than those observed in the adult population under study.
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•Human exposure to waste incinerator emissions is of great concern.•No impact of the WTE plant was observed on human exposure to PCDDs, PCDFs, and PCBs.•PCDD, PCDF and PCB decrease was observed at T2 in exposed and not exposed groups.•Observed concentrations of PCDDs, PCDFs, and PCBs were higher in females.
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