Static dielectric response of icosahedral fullerenes from C60 to C2160 by an all electron density functional theory

The static dielectric response of C60, C180, C240, C540, C720, C960, C1500, and C2160 fullerenes is characterized by an all-electron density-functional method. First, the screened polarizabilities of C60, C180, C240, and C540, are determined by the finite-field method using Gaussian basis set containing 35 basis functions per atom. In the second set of calculations, the unscreened polarizabilities are calculated for fullerenes C60 through C2160 from the self-consistent Kohn-Sham orbitals and eigen-values using the sum-over-states method. The approximate screened polarizabilities, obtained by applying a correction determined within linear response theory show excellent agreement with the finite-field polarizabilities. The static dipole polarizability per atom in C2160 is (4 Angstrom^3) three times larger than that in C60 (1.344 Angstrom^3). Our results reduce the uncertainty in various theoretical models used previously to describe the dielectric response of fullerenes and show that quantum size effects in polarizability are significantly smaller than previously thought.Comment: RevTex, 3 figure

Interstellar Communication: The Case for Spread Spectrum

Spread spectrum, widely employed in modern digital wireless terrestrial radio systems, chooses a signal with a noise-like character and much higher bandwidth than necessary. This paper advocates spread spectrum modulation for interstellar communication, motivated by robust immunity to radio-frequency interference (RFI) of technological origin in the vicinity of the receiver while preserving full detection sensitivity in the presence of natural sources of noise. Receiver design for noise immunity alone provides no basis for choosing a signal with any specific character, therefore failing to reduce ambiguity. By adding RFI to noise immunity as a design objective, the conjunction of choice of signal (by the transmitter) together with optimum detection for noise immunity (in the receiver) leads through simple probabilistic argument to the conclusion that the signal should possess the statistical properties of a burst of white noise, and also have a large time-bandwidth product. Thus spread spectrum also provides an implicit coordination between transmitter and receiver by reducing the ambiguity as to the signal character. This strategy requires the receiver to guess the specific noise-like signal, and it is contended that this is feasible if an appropriate pseudorandom signal is generated algorithmically. For example, conceptually simple algorithms like the binary expansion of common irrational numbers like Pi are shown to be suitable. Due to its deliberately wider bandwidth, spread spectrum is more susceptible to dispersion and distortion in propagation through the interstellar medium, desirably reducing ambiguity in parameters like bandwidth and carrier frequency. This suggests a promising new direction in interstellar communication using spread spectrum modulation techniques

RNAseq Analyses Identify Tumor Necrosis Factor-Mediated Inflammation as a Major Abnormality in ALS Spinal Cord

ALS is a rapidly progressive, devastating neurodegenerative illness of adults that produces disabling weakness and spasticity arising from death of lower and upper motor neurons. No meaningful therapies exist to slow ALS progression, and molecular insights into pathogenesis and progression are sorely needed. In that context, we used high-depth, next generation RNA sequencing (RNAseq, Illumina) to define gene network abnormalities in RNA samples depleted of rRNA and isolated from cervical spinal cord sections of 7 ALS and 8 CTL samples. We aligned \u3e50 million 2X150 bp paired-end sequences/sample to the hg19 human genome and applied three different algorithms (Cuffdiff2, DEseq2, EdgeR) for identification of differentially expressed genes (DEG’s). Ingenuity Pathways Analysis (IPA) and Weighted Gene Co-expression Network Analysis (WGCNA) identified inflammatory processes as significantly elevated in our ALS samples, with tumor necrosis factor (TNF) found to be a major pathway regulator (IPA) and TNFα-induced protein 2 (TNFAIP2) as a major network “hub” gene (WGCNA). Using the oPOSSUM algorithm, we analyzed transcription factors (TF) controlling expression of the nine DEG/hub genes in the ALS samples and identified TF’s involved in inflammation (NFkB, REL, NFkB1) and macrophage function (NR1H2::RXRA heterodimer). Transient expression in human iPSC-derived motor neurons of TNFAIP2 (also a DEG identified by all three algorithms) reduced cell viability and induced caspase 3/7 activation. Using high-density RNAseq, multiple algorithms for DEG identification, and an unsupervised gene co-expression network approach, we identified significant elevation of inflammatory processes in ALS spinal cord with TNF as a major regulatory molecule. Overexpression of the DEG TNFAIP2 in human motor neurons, the population most vulnerable to die in ALS, increased cell death and caspase 3/7 activation. We propose that therapies targeted to reduce inflammatory TNFα signaling may be helpful in ALS patients

Seasonality of Leaf and Fig Production in Ficus squamosa, a Fig Tree with Seeds Dispersed by Water

The phenology of plants reflects selection generated by seasonal climatic factors and interactions with other plants and animals, within constraints imposed by their phylogenetic history. Fig trees (Ficus) need to produce figs year-round to support their short-lived fig wasp pollinators, but this requirement is partially de-coupled in dioecious species, where female trees only develop seeds, not pollinator offspring. This allows female trees to concentrate seed production at more favorable times of the year. Ficus squamosa is a riparian species whose dispersal is mainly by water, rather than animals. Seeds can float and travel in long distances. We recorded the leaf and reproductive phenology of 174 individuals for three years in Chiang Mai, Northern Thailand. New leaves were produced throughout the year. Fig production occurred year-round, but with large seasonal variations that correlated with temperature and rainfall. Female and male trees initiated maximal fig crops at different times, with production in female trees confined mainly to the rainy season and male figs concentrating fig production in the preceding months, but also often bearing figs continually. Ficus squamosa concentrates seed production by female plants at times when water levels are high, favouring dispersal by water, and asynchronous flowering within male trees allow fig wasps to cycle there, providing them with potential benefits by maintaining pollinators for times when female figs become available to pollinate

CONCURRENT AND CONCORDANT ORAL AND GENITAL HIGH RISK HUMAN PAPILLOMAVIRUS INFECTIONS IN THE UNITED STATES POPULATION; RESULTS FROM NATIONAL HEALTH AND NUTRITION EXAMINATION SURVEY (NHANES)

Human papillomavirus (HPV) is a common sexually transmitted disease which infects various sites in the body including the genitals, oral cavity, and anal regions. Very little research has assessed the prevalence of concurrent and concordant high risk (HR) HPV oral and genital infections in the general United States population despite the fact that HR HPV oral pharyngeal cancers are on the rise in the US, particularly in men. To further our understanding of HR HPV concurrent and concordant infections we aim to estimate the prevalence of HR HPV concurrent and concordant infections in the U.S. population, and for men and women separately. The next aim is to determine via Monte Carlo simulations, whether HR HPV concurrent and concordant infections happen more than expected by chance, given the population marginal rates of oral and genital infections. Lastly, we characterize predictors of HR HPV concurrent and concordant infections. We use the cross-sectional National Health and Nutrition Examination Survey (NHANES). Participants included women from NHANES 2009-2014 and men from NHANES 2013-2014 who had valid HPV test results. Concurrent infections were identified in 116 (2.5%) individuals in the combined population (65 (4.0%) men and 51 (.76%) women). Simulations showed that the observed prevalence of concurrent infections exceeded the expected prevalence for the combined population, men, and women (1.13%, 4.0%, and .76%, respectively). Similarly, we identified concordant infections in 59 (.99%) of individuals (29 (1.5%) men and 30 (.47%) women). Simulations showed that the observed prevalence of concordant infections exceeded the expected prevalence for the combined population, men, and women (.15%, .26%, and .05% respectively). Our multivariable analysis for men showed marital status, lifetime number of sexual partners, lifetime number of oral sex partners, recent number of oral sex partners, marijuana use, and sexual orientation were all positively associated with HR HPV concurrent infection, and lifetime number of sex partners, recent number of sex partners, and sexual orientation were positively associated with HR concordant infections. Our multivariable analysis for womenshowednopredictorswereassociatedwithHRHPVconcurrentinfections, and cigarette use was positively associated with HR HPV concordant infections. Importantly, our analyses show that HR HPV infections between the oral and genital sites are not independent of one another. We further highlight several factors that are important predictors of HR HPV concurrent and concordant infections. These analyses show the importance of the HPV vaccine and suggest its continued recommendation, perhaps more adamantly in boys and men than previously suggested