The interplay between divergence and phenotypic plasticity is critical to our understanding of a species' adaptive potential under rapid climate changes. We investigated divergence and plasticity in ...natural populations of the Pacific oyster Crassostrea gigas with a congeneric oyster Crassostrea angulata from southern China used as an outgroup. Genome re-sequencing of 371 oysters revealed unexpected genetic divergence in a small area that coincided with phenotypic divergence in growth, physiology, heat tolerance and gene expression across environmental gradients. These findings suggest that selection and local adaptation are pervasive and, together with limited gene flow, influence population structure. Genes showing sequence differentiation between populations also diverged in transcriptional response to heat stress. Plasticity in gene expression is positively correlated with evolved divergence, indicating that plasticity is adaptive and favoured by organisms under dynamic environments. Divergence in heat tolerance-partly through acetylation-mediated energy depression-implies differentiation in adaptive potential. Trade-offs between growth and survival may play an important role in local adaptation of oysters and other marine invertebrates.
People that committed suicide were reported to have enhanced levels of gene transcripts for synaptic proteins in their prefrontal cortex (PFC). Given the close association of suicide with major ...depressive disorder (MDD), we here assessed whether these changes are related to suicide or rather to depression per se.
We used quantitative PCR to determine mRNA levels of 32 genes encoding for proteins directly involved in glutamatergic or GABAergic synaptic transmission in postmortem samples of the anterior cingulate cortex (ACC) and the dorsolateral PFC (DLPFC). Seventy-two brain samples from 3 groups of subjects were derived from the Stanley Medical Research Institute (SMRI): i) patients with MDD who committed suicide (MDD-S), ii) MDD patients who died of non-suicidal causes (MDD-NS) and iii) age-matched, non-psychiatric control subjects.
In the ACC, a significantly enhanced expression of genes related to glutamatergic or GABAergic synaptic transmission was found only in MDD-S patients, whereas in MDD-NS patients, decreased levels for these transcripts were found. Moreover, in the DLPFC, expression of these genes was decreased in MDD-S, relative to MDD-NS patients, whereas both groups showed increased expression compared to control subjects.
In conclusion, our findings indicate that MDD is associated with increases in GABA and glutamate related genes in the DLPFC (irrespective of suicide), while in the ACC, the increase in GABA and glutamate related genes may relate to suicide, rather than to MDD per se.
1 Department of Geriatric Medicine, Radboud University Nijmegen Medical Center, The Netherlands; and 2 Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas and The ...University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
Submitted 16 August 2006
; accepted in final form 12 November 2006
Clinical transcranial Doppler assessment of cerebral vasomotor reactivity (CVMR) uses linear regression of cerebral blood flow velocity (CBFV) vs. end-tidal CO 2 (P ET CO 2 ) under steady-state conditions. However, the cerebral blood flow (CBF)-P ET CO 2 relationship is nonlinear, even for moderate changes in CO 2 . Moreover, CBF is increased by increases in arterial blood pressure (ABP) during hypercapnia. We used a modified rebreathing protocol to estimate CVMR during transient breath-by-breath changes in CBFV and P ET CO 2 . Ten healthy subjects (6 men) performed 15 s of hyperventilation followed by 5 min of rebreathing, with supplemental O 2 to maintain arterial oxygen saturation constant. To minimize effects of changes in ABP on CVMR estimation, cerebrovascular conductance index (CVCi) was calculated. CBFV-P ET CO 2 and CVCi-P ET CO 2 relationships were quantified by both linear and nonlinear logistic regression. In three subjects, muscle sympathetic nerve activity was recorded. From hyperventilation to rebreathing, robust changes occurred in P ET CO 2 (2061 Torr), CBFV (44 to +104% of baseline), CVCi (39 to +64%), and ABP (19 to +23%) (all P < 0.01). Muscle sympathetic nerve activity increased by 446% during hypercapnia. The linear regression slope of CVCi vs. P ET CO 2 was less steep than that of CBFV (3 vs. 5%/Torr; P = 0.01). Logistic regression of CBF-P ET CO 2 ( r 2 = 0.97) and CVCi-P ET CO 2 ( r 2 = 0.93) was superior to linear regression ( r 2 = 0.91, r 2 = 0.85; P = 0.01). CVMR was maximal (68%/Torr) for P ET CO 2 of 4050 Torr. In conclusion, CBFV and CVCi responses to transient changes in P ET CO 2 can be described by a nonlinear logistic function, indicating that CVMR estimation varies within the range from hypocapnia to hypercapnia. Furthermore, quantification of the CVCi-P ET CO 2 relationship may minimize the effects of changes in ABP on the estimation of CVMR. The method developed provides insight into CVMR under transient breath-by-breath changes in CO 2 .
blood pressure; carbon dioxide
Address for reprint requests and other correspondence: R. Zhang, Institute for Exercise and Environmental Medicine, Presbyterian Hospital of Dallas, 7232 Greenville Ave., Dallas, TX 75231 (e-mail: RongZhang{at}texashealth.org )
The effect of carbon impurities on electrical resistivity of Mg doped GaN grown by metal organic chemical vapor deposition (MOCVD) was investigated. It was noted that when the growth rate increases ...or the growth pressure decreases, the resistivity of p-GaN increases and the quality of p-type conductivity of epitaxial GaN deteriorates. The intensity of yellow luminescence (YL) in photoluminescence (PL) spectra was strengthened at the same time. Due to the compensation effect of carbon impurities on magnesium, it makes a significant influence on the electrical resistivity in p-GaN. Carbon impurities may form deep donors, resulting in yellow luminescence (YL) in photoluminescence spectra and compensate Mg acceptors to increase the resistivity of p-GaN. Thus, the low resistivity p-type GaN films can be obtained only when we appropriately reduce growth rate and improve reaction chamber pressure to reduce the residual carbon impurity concentration.
CXCL13 plays a unique role in the trafficking and homing of B1 cells associated with its cognate receptor, CXCR5. The CXCR5-CXCL13 axis has been previously demonstrated to be a poor prognosis factor ...in malignancies. However, the clinical significance of the CXCR5-CXCL13 expression in colorectal cancer carcinoma (CRC) remains unclear. The aim of this study was to investigate the CXCR5-CXCL13 expression in CRC and determine its correlation with the progression and prognosis of the tumor.
A total of 144 paraffin-embedded specimens with advanced colon cancer were assessed for CXCR5 and CXCL13 by immunohistochemistry. Patients' long-term survival was also monitored. There were significant differences in lymph node metastasis (p = 0.0066), neural invasion (p = 0.0061) and neural invasion (p = 0.0001) between high and low expression of CXCR5.
There were significant differences in distant metastasis (p = 0.0261), TNM stage (p = 0.0409), differentiation (p < 0.0001) and neural invasion of the CXCL13. Both CXCR5 and CXCL13 was associated with poor correlation with the overall survival (OS) and relapse-free survival (RFS).
Our data suggest that the CXCR5 and CXCL13 may play a crucial role in the development, metastasis and relapse of advanced colon cancer. They can be used as prognostic markers of colon cancer in clinical practice.
We present a new determination of the smallest neutrino mixing angle θ_{13} and the mass-squared difference Δm_{32}^{2} using a final sample of 5.55×10^{6} inverse beta-decay (IBD) candidates with ...the final-state neutron captured on gadolinium. This sample is selected from the complete dataset obtained by the Daya Bay reactor neutrino experiment in 3158 days of operation. Compared to the previous Daya Bay results, selection of IBD candidates has been optimized, energy calibration refined, and treatment of backgrounds further improved. The resulting oscillation parameters are sin^{2}2θ_{13}=0.0851±0.0024, Δm_{32}^{2}=(2.466±0.060)×10^{-3} eV^{2} for the normal mass ordering or Δm_{32}^{2}=-(2.571±0.060)×10^{-3} eV^{2} for the inverted mass ordering.
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The extension of the cosmic-ray spectrum beyond 1 petaelectronvolt (PeV; 10
electronvolts) indicates the existence of the so-called PeVatrons-cosmic-ray factories that accelerate particles to PeV ...energies. We need to locate and identify such objects to find the origin of Galactic cosmic rays
. The principal signature of both electron and proton PeVatrons is ultrahigh-energy (exceeding 100 TeV) γ radiation. Evidence of the presence of a proton PeVatron has been found in the Galactic Centre, according to the detection of a hard-spectrum radiation extending to 0.04 PeV (ref.
). Although γ-rays with energies slightly higher than 0.1 PeV have been reported from a few objects in the Galactic plane
, unbiased identification and in-depth exploration of PeVatrons requires detection of γ-rays with energies well above 0.1 PeV. Here we report the detection of more than 530 photons at energies above 100 teraelectronvolts and up to 1.4 PeV from 12 ultrahigh-energy γ-ray sources with a statistical significance greater than seven standard deviations. Despite having several potential counterparts in their proximity, including pulsar wind nebulae, supernova remnants and star-forming regions, the PeVatrons responsible for the ultrahigh-energy γ-rays have not yet been firmly localized and identified (except for the Crab Nebula), leaving open the origin of these extreme accelerators.
In patients with celiac disease, gluten triggers an immune reaction that damages small intestinal villi and may increase long-term risk of gastrointestinal cancer. However, the health impacts of ...gluten in the general population are understudied. We aimed to examine the association between gluten intake and risk of digestive system cancers among individuals without celiac disease.
We leveraged longitudinal data from 3 prospective cohorts, the Nurses' Health Study (1984-2018, 73,166 women aged 65.1 ± 10.8 years), Nurses' Health Study II (1991-2017, 90,423 women aged 49.1 ± 8.2 years), and Health Professionals Follow-Up Study (1986-2016, 42,617 men aged 64.8 ± 10.8 years). Using Cox proportional hazards regression, we estimated hazard ratios and 95% confidence intervals of digestive system cancers according to quintiles of gluten intake assessed from food frequency questionnaires.
During 4,801,513 person-years of follow-up, we documented 6231 incident digestive system cancer cases among 3 cohorts. After adjusting for a wide-range of risk factors, including body mass index, physical activity, diet quality, gluten intake was not associated with an increased risk of digestive system cancer, with a hazard ratio of 0.94 (95% confidence interval, 0.87-1.02) comparing the highest with the lowest quintile of gluten intake (P trend = .05). Similar null associations were found for individual digestive system cancers: oral cavity and oropharyngeal cancer, esophageal cancer, stomach cancer, small intestine cancer, colorectal cancer, pancreatic cancer, gallbladder cancer, and liver cancer.
Gluten intake was not associated with risk of digestive system cancers in adults without celiac disease. Restricting dietary gluten is unlikely to be beneficial to the prevention of digestive system cancers in the general population.
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