Capacity of Molecular Channels with Imperfect Particle-Intensity Modulation and Detection

This work introduces the particle-intensity channel (PIC) as a model for molecular communication systems and characterizes the properties of the optimal input distribution and the capacity limits for this system. In the PIC, the transmitter encodes information, in symbols of a given duration, based on the number of particles released, and the receiver detects and decodes the message based on the number of particles detected during the symbol interval. In this channel, the transmitter may be unable to control precisely the number of particles released, and the receiver may not detect all the particles that arrive. We demonstrate that the optimal input distribution for this channel always has mass points at zero and the maximum number of particles that can be released. We then consider diffusive particle transport, derive the capacity expression when the input distribution is binary, and show conditions under which the binary input is capacity-achieving. In particular, we demonstrate that when the transmitter cannot generate particles at a high rate, the optimal input distribution is binary.Comment: Accepted at IEEE International Symposium on Information Theory (ISIT

A Combinatorial Premotor Neural Code: Transformation Of Sensory Information Into Meaningful Rhythmic Motor Output By A Network Of Heterogeneous Modulatory Neurons

The goal of the following research was to investigate the contributions of neural networks in selecting distinct variants of rhythmic motor activity. We used the premotor commissural ganglion (CoG) in the stomatogastric nervous system of the Jonah crab to understand how this network effectively controls the rhythms produced in downstream motor circuits. Prior research determined that individual CoG neurons are necessary to mediate sensory-induced variation in the effected motor patterns. However, single premotor neuron inputs to the STG are not sufficient to recreate the patterns induced by the selective activation of sensory pathways. Thus, it was hypothesized that the CoG-mediated effects on these sensorimotor transformations must be explained at the level of CoG population activity. We embraced the exploratory nature of this study by approaching it in three phases. First, we established voltage-sensitive dye imaging in the stomatogastric nervous system, as a technique that reports the simultaneous activity of many neurons with single-neuron resolution. In short, this form of imaging was effective at reporting both slow and fast changes in membrane potential, and provided an effective means of staining fine neural structures through neural sheaths, structures that often act as barriers to many substances. Then, we characterized the distribution of somata in the CoG, and found that soma location was not fixed in its location from animal to animal, but that clustering of CoG somata did occur near their different nerve pathway origins. Finally, we used the voltage-sensitive dye-imaging technique to investigate the CoG population under many different sensory conditions, and found that two different sensory modalities, one chemosensory and one mechanosensory pathway, differentially affected the balance of excited and inhibited (network activation) neurons found in the CoGs. Moreover, differences in the composition of CoG participants between modalities was not extremely robust. However, it differed enough so that both CoG participation and activation were drivers of the observed changes in the downstream pyloric motor network, providing support for a premotor combinatorial code for motor pattern selection

Ultrasound increases the aqueous extraction of phenolic compounds with high antioxidant activity from olive pomace

Olive pomace is a waste produced by the olive oil industry in massive quantities each year. Disposal of olive pomace is difficult due to high concentrations of phenolic compounds, which is an environmental concern. However, phenolic compounds have applications in the health industry. Therefore, extraction of phenolic compounds from olive pomace has the potential to remove an environmentally hazardous portion of pomace while creating an additional source of income for farmers and producers. Using advanced technologies including Ultrasound Assisted Extraction (UAE), combined with water as an extraction solvent, has recently gained popularity. The present study outlines the optimal UAE conditions for the extraction of phenolic compounds with high antioxidant activity from olive pomace. Optimal conditions were developed using RSM for parameters power, time and sample-to-solvent ratio. Total phenolic compounds determined by Folin Ciocalteu method and total major bioactive compounds determined by HPLC as well as antioxidant capacity (DPPH and CUPRAC) were investigated. The optimal conditions for the extraction of phenolic compounds with high antioxidant activity were 2 g of dried pomace/100 mL of water at 250 W power for 75 min. UAE improved the extraction efficiency of water and yielded extracts with high levels of phenolic compounds and strong antioxidant activity

Heterogeneity in susceptibility dictates the order of epidemiological models

The fundamental models of epidemiology describe the progression of an infectious disease through a population using compartmentalized differential equations, but do not incorporate population-level heterogeneity in infection susceptibility. We show that variation strongly influences the rate of infection, while the infection process simultaneously sculpts the susceptibility distribution. These joint dynamics influence the force of infection and are, in turn, influenced by the shape of the initial variability. Intriguingly, we find that certain susceptibility distributions (the exponential and the gamma) are unchanged through the course of the outbreak, and lead naturally to power-law behavior in the force of infection; other distributions often tend towards these "eigen-distributions" through the process of contagion. The power-law behavior fundamentally alters predictions of the long-term infection rate, and suggests that first-order epidemic models that are parameterized in the exponential-like phase may systematically and significantly over-estimate the final severity of the outbreak

The olive biophenols oleuropein and hydroxytyrosol selectively reduce proliferation, influence the cell cycle, and induce apoptosis in pancreatic cancer cells

Current chemotherapy drugs for pancreatic cancer only offer an increase in survival of up to six months. Additionally, they are highly toxic to normal tissues, drastically affecting the quality of life of patients. Therefore, the search for novel agents, which induce apoptosis in cancer cells while displaying limited toxicity towards normal cells, is paramount. The olive biophenols, oleuropein, hydroxytyrosol and tyrosol, have displayed cytotoxicity towards cancer cells without affecting non-tumorigenic cells in cancers of the breast and prostate. However, their activity in pancreatic cancer has not been investigated. Therefore, the aim of this study was to determine the anti-pancreatic cancer potential of oleuropein, hydroxytyrosol and tyrosol. Pancreatic cancer cells (MIA PaCa-2, BxPC-3, and CFPAC-1) and non-tumorigenic pancreas cells (HPDE) were treated with oleuropein, hydroxytyrosol and tyrosol to determine their effect on cell viability. Oleuropein displayed selective toxicity towards MIA PaCa-2 cells and hydroxytyrosol towards MIA PaCa-2 and HPDE cells. Subsequent analysis of Bcl-2 family proteins and caspase 3/7 activation determined that oleuropein and hydroxytyrosol induced apoptosis in MIA PaCa-2 cells, while oleuropein displayed a protective effect on HPDE cells. Gene expression analysis revealed putative mechanisms of action, which suggested that c-Jun and c-Fos are involved in oleuropein and hydroxytyrosol induced apoptosis of MIA PaCa-2 cells

Toward a Blended Ontology: Applying Knowledge Systems to Compare Therapeutic and Toxicological Nanoscale Domains

Bionanomedicine and environmental research share need common terms and ontologies. This study applied knowledge systems, data mining, and bibliometrics used in nano-scale ADME research from 1991 to 2011. The prominence of nano-ADME in environmental research began to exceed the publication rate in medical research in 2006. That trend appears to continue as a result of the growing products in commerce using nanotechnology, that is, 5-fold growth in number of countries with nanomaterials research centers. Funding for this research virtually did not exist prior to 2002, whereas today both medical and environmental research is funded globally. Key nanoparticle research began with pharmacology and therapeutic drug-delivery and contrasting agents, but the advances have found utility in the environmental research community. As evidence ultrafine aerosols and aquatic colloids research increased 6-fold, indicating a new emphasis on environmental nanotoxicology. User-directed expert elicitation from the engineering and chemical/ADME domains can be combined with appropriate Boolean logic and queries to define the corpus of nanoparticle interest. The study combined pharmacological expertise and informatics to identify the corpus by building logical conclusions and observations. Publication records informatics can lead to an enhanced understanding the connectivity between fields, as well as overcoming the differences in ontology between the fields

Carbonate Control of H(2) and Ch(4) Production in Serpentinization Systems at Elevated P-Ts

Serpentinization of forsteritic olivine results in the inorganic synthesis of molecular hydrogen (H(2)) in ultramafic hydrothermal systems (e. g., mid-ocean ridge and forearc environments). Inorganic carbon in those hydrothermal systems may react with H(2) to produce methane (CH(4)) and other hydrocarbons or react with dissolved metal ions to form carbonate minerals. Here, we report serpentinization experiments at 200 degrees C and 300 bar demonstrating Fe(2+) being incorporated into carbonates more rapidly than Fe(2+) oxidation (and concomitant H(2) formation) leading to diminished yields of H(2) and H(2)-dependent CH(4). In addition, carbonate formation is temporally fast in carbonate oversaturated fluids. Our results demonstrate that carbonate chemistry ultimately modulates the abiotic synthesis of both H(2) and CH(4) in hydrothermal ultramafic systems and that ultramafic systems present great potential for CO(2)-mineral sequestration

New Tolerance Factor to Predict the Stability of Perovskite Oxides and Halides

Predicting the stability of the perovskite structure remains a longstanding challenge for the discovery of new functional materials for many applications including photovoltaics and electrocatalysts. We developed an accurate, physically interpretable, and one-dimensional tolerance factor, {\tau}, that correctly predicts 92% of compounds as perovskite or nonperovskite for an experimental dataset of 576 $ABX_3$ materials ($\textit{X} =$ $O^{2-}$, $F^-$, $Cl^-$, $Br^-$, $I^-$) using a novel data analytics approach based on SISSO (sure independence screening and sparsifying operator). {\tau} is shown to generalize outside the training set for 1,034 experimentally realized single and double perovskites (91% accuracy) and is applied to identify 23,314 new double perovskites ($A_2$$\textit{BB'}$$X_6$) ranked by their probability of being stable as perovskite. This work guides experimentalists and theorists towards which perovskites are most likely to be successfully synthesized and demonstrates an approach to descriptor identification that can be extended to arbitrary applications beyond perovskite stability predictions