Temporal Dynamics of Distinct CA1 Cell Populations during Unconscious State Induced by Ketamine

Ketamine is a widely used dissociative anesthetic which can induce some psychotic-like symptoms and memory deficits in some patients during the post-operative period. To understand its effects on neural population dynamics in the brain, we employed large-scale in vivo ensemble recording techniques to monitor the activity patterns of simultaneously recorded hippocampal CA1 pyramidal cells and various interneurons during several conscious and unconscious states such as awake rest, running, slow wave sleep, and ketamine-induced anesthesia. Our analyses reveal that ketamine induces distinct oscillatory dynamics not only in pyramidal cells but also in at least seven different types of CA1 interneurons including putative basket cells, chandelier cells, bistratified cells, and O-LM cells. These emergent unique oscillatory dynamics may very well reflect the intrinsic temporal relationships within the CA1 circuit. It is conceivable that systematic characterization of network dynamics may eventually lead to better understanding of how ketamine induces unconsciousness and consequently alters the conscious mind

Effects of the transmissibility and virulence of pathogens on intraguild predation in fragmented landscapes

It is well known that pathogenic infection can have a profound effect on the outcome of competition and predation, however the role of pathogenic infection in systems where predators and prey also compete for other resources is yet to be explored (i.e. in systems of intraguild predation). Using a cellular automaton model, we here explore the effect of pathogenic infection on the spatial dynamics of species that also engage in intraguild predation (IGP) in a fragmented landscape. First, the shared pathogen by the predator and prey can enhance species coexistence in the IGP system, consistent with results for non-spatial IGP systems. Second, equilibrium population sizes of the predator and prey depend crucially on the pathogen virulence to the predator but are insensitive to the change in the virulence to the prey. This asymmetric response to virulence change is due to the fact that the predator species has to juggle between predation, resource competition and pathogenic infection. Finally, the response of the pathogen to habitat fragmentation is largely determined by its life-history strategy (transmissibility and virulence) and the trophic level of its host. These results enrich our understanding on the role of pathogens in the ecosystem functioning of eco-epidemiological systems

Characterizing the malignancy and drug resistance of cancer cells from their membrane resealing response

In this report, we showed that two tumor cell characteristics, namely the malignancy and drug-resistance status can be evaluated by their membrane resealing response. Specifically, membrane pores in a number of pairs of cancer and normal cell lines originated from nasopharynx, lung and intestine were introduced by nano-mechanical puncturing. Interestingly, such nanometer-sized holes in tumor cells can reseal ∼ 2-3 times faster than those in the corresponding normal cells. Furthermore, the membrane resealing time in cancer cell lines exhibiting resistance to several leading chemotherapeutic drugs was also found to be substantially shorter than that in their drug-sensitive counterparts, demonstrating the potential of using this quantity as a novel marker for future cancer diagnosis and drug resistance detection. Finally, a simple model was proposed to explain the observed resealing dynamics of cells which suggested that the distinct response exhibited by normal, tumor and drug resistant cells is likely due to the different tension levels in their lipid membranes, a conclusion that is also supported by direct cortical tension measurement.published_or_final_versio

A Systematic Review and Meta-Analysis of Short-Term Ambient Ozone Exposure and COPD Hospitalizations

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death globally and ozone exposure is

Excitation cross section of erbium-doped GaN waveguides under 980 nm optical pumping

This is the published version. Copyright 2015 American Institute of PhysicsExcitation cross section of erbium-doped GaN waveguides is measured to be approximately 2.2×10−21cm2 at 980 nm pumping wavelength. This cross section value is found relatively insensitive to the crystalline quality of epilayers. However, spontaneous emission carrier lifetimes in these waveguides are directly related to both the crystalline quality and the optical loss, and thus can be used as a material quality indicator

Human papillomavirus viral load as a useful triage tool for non-16/18 high-risk human papillomavirus positive women: A prospective screening cohort study

ASCCP cervical cancer screening guidelines recommend triaging high-risk human papillomavirus (hrHPV) positive women with cytology and genotyping, but cytology is often unavailable in resource-limited areas. We compared the long-term risk of cervical cancer and precancers among type-specific hrHPV-positive women triaged by viral load to cytology and visual inspection with acetic acid (VIA).A cohort of 1742 Chinese women was screened with cytology, VIA, and Hybrid Capture 2 (HC2) test and followed for ten years. All HC2-positive samples were genotyped. Viral load was measured by HC2 relative light units/cutoff (RLU/CO). Ten-year cumulative incidence rate (CIR) of cervical intraepithelial neoplasia grade 2 or worse (CIN2 +) for type-specific hrHPV viral load was estimated using Kaplan-Meier methods.Baseline hrHPV viral load stratified by specific genotypes was positively correlated with prevalent cytological lesions. Ten-year CIR of CIN2 + was associated with cytological lesions and viral load. Among HPV 16/18-positive women, ten-year CIR of CIN2 + was high, even with normal cytology (15.3%), normal VIA (32.4%), viral load with RLU/CO < 10 (23.6%) or RLU/CO < 100 (33.8%). Among non-16/18 hrHPV positive women, ten-year CIR of CIN2 + was significantly stratified by cytology grade of atypical squamous cell of undetermined significance or higher (2.0% VS. 34.6%), viral load cutoffs at 10 RLU/CO (5.1% VS. 27.2%), at 100 RLU/CO (11.0% VS. 35.5%), but not by VIA (19.1% VS. 19.0%).Our findings support the guidelines in referring all HPV16/18 positive women to colposcopy and suggest triaging non-16/18 hrHPV positive women using viral loads in resource-limited areas where cytology screening was inaccessible

Superconductivity near the vibrational mode instability in MgCNi3

To understand the role of electron-phonon interaction in superconducting MgCNi$_{3}$ we have performed density functional based linear response calculations of its lattice dynamical properties. A large coupling constant $\lambda$= 1.51 is predicted and contributing phonons are identified as displacements of Ni atoms towards octahedral interstitials of the perovskite lattice. Instabilities found for some vibrational modes emphasize the role of anharmonic effects in resolving experimental controversies.Comment: 4 pages, 4 eps figures, replaces the older versio