Polyparameter linear free energy relationship for wood char–water sorption coefficients of organic sorbates

Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Environmental Toxicology and Chemistry 34 (2015): 1464-1471, doi:10.1002/etc.2951.Black carbons (BCs), including soots, chars, activated carbons, and engineered nanocarbons, have different surface properties, but we do not know to what extent these affect their sorbent properties. To evaluate this for an environmentally ubiquitous form of BC, biomass char, we probed the surface of a well-studied wood char using 14 sorbates exhibiting diverse functional groups and then fit the data with a polyparameter linear free energy relationship (ppLFER) to assess the importance of the various possible sorbate-char surface interactions. Sorption from water to water-wet char evolved with the sorbate's degree of surface saturation and depended on only a few sorbate parameters: log Kd(L/kg) = [(4.03 ± 0.14) + (-0.15 ± 0.04) log ai)] V + [(-0.28 ± 0.04) log ai)] S + (-5.20 ± 0.21) B where ai is the aqueous saturation of the sorbate i, V is McGowan’s characteristic volume, S reflects polarity, and B represents the electron-donation basicity. As generally observed for activated carbon, the sorbate’s size encouraged sorption from water to the char, while its electron donation/proton acceptance discouraged sorption from water. However, the magnitude and saturation dependence differed significantly from what has been seen for activated carbons, presumably reflecting the unique surface chemistries of these two BC materials and suggesting BC-specific sorption coefficients will yield more accurate assessments of contaminant mobility and bioavailability and evaluation of a site's response to remediation.This material is based upon work supported by the U.S. Army Corps of Engineering, Humphreys Engineer Center Support Activity under Contract No. W912HQ-10-C-0005 awarded as part of the SERDP program.2016-05-1

Tunneling in a cavity

The mechanism of coherent destruction of tunneling found by Grossmann et al. [Phys. Rev. Lett. 67, 516 (1991)] is studied from the viewpoint of quantum optics by considering the photon statistics of a single mode cavity field which is strongly coupled to a two-level tunneling system (TS). As a function of the interaction time between TS and cavity the photon statistics displays the tunneling dynamics. In the semi-classical limit of high photon occupation number $n$, coherent destruction of tunneling is exhibited in a slowing down of an amplitude modulation for certain parameter ratios of the field. The phenomenon is explained as arising from interference between displaced number states in phase space which survives the large $n$ limit due to identical $n^{-1/2}$ scaling between orbit width and displacement.Comment: 4 pages Revtex, 2 PS-figures, appears in The Physical Review

Critical periods of increased fetal vulnerability to a maternal high fat diet

Background: Fetal adaptations to high fat (HF) diet in utero (IU) that may predispose to Metabolic Syndrome (MetS) in adulthood include changes in fetal hepatic gene expression. Studies were performed to determine whether maternal exposure to HF diet at different stages during pregnancy had different effects on the fetus, including hepatic gene expression. Methods: Female wild type mice were fed either a HF or breeding chow (C) for 2 wks prior to mating. The experimental groups were composed of embryonic day (e) 18.5 fetuses obtained from WT female mice that were fed HF (HF, 35.5% fat) or breeding chow (C, 9.5% fat) for 2 wk before mating until e9.5 of pregnancy (periconception-midpregnancy). At e9.5 dams were switched to the opposite diet (C-HF or HF-C). Results: Exposure to HF diet throughout pregnancy reduced maternal weight gain compared to C diet (p \u3c 0.02 HF vs. C). HF-C dams had significantly decreased adiponectin levels and litter size when compared to C-HF (p \u3c 0.02 HF-C vs C-HF). Independent of the timing of exposure to HF, fetal weight and length were significantly decreased when compared to C diet (HF, C-HF and HF-C vs. C p \u3c 0.02). HF diet during the second half of pregnancy increased expression of genes in the fetal liver associated with fetal growth (C-HF vs C p \u3c 0.001), glucose production (C-HF vs C p \u3c 0.04), oxidative stress and inflammation (C-HF vs C p \u3c 0.01) compared to C diet. Conclusions: This model defines that there are critical periods during gestation in which the fetus is actively shaped by the environment. Early exposure to a HF diet determines litter size while exposure to HF during the second half of pregnancy leads to dysregulation of expression of key genes responsible for fetal growth, hepatic glucose production and oxidative stress. These findings underscore the importance of future studies designed to clarify how these critical periods may influence future risk of developing MetS later in life

Survival of dental implants in patients with oral cancer treated by surgery and radiotherapy: a retrospective study

BACKGROUND: The aim of this retrospective study was to evaluate the survival of dental implants placed after ablative surgery, in patients affected by oral cancer treated with or without radiotherapy. METHODS: We collected data for 34 subjects (22 females, 12 males; mean age: 51 ± 19) with malignant oral tumors who had been treated with ablative surgery and received dental implant rehabilitation between 2007 and 2012. Postoperative radiation therapy (less than 50 Gy) was delivered before implant placement in 12 patients. A total of 144 titanium implants were placed, at a minimum interval of 12 months, in irradiated and non-irradiated residual bone. RESULTS: Implant loss was dependent on the position and location of the implants (P = 0.05-0.1). Moreover, implant survival was dependent on whether the patient had received radiotherapy. This result was highly statistically significant (P < 0.01). Whether the implant was loaded is another highly significant (P < 0.01) factor determinin

Elevated levels of diesel range organic compounds in groundwater near Marcellus gas operations are derived from surface activities

Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of National Academy of Sciences for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of American 112 (2015): 13184-13189, doi: 10.1073/pnas.1511474112 .Hundreds of organic chemicals are utilized during natural gas extraction via high volume hydraulic fracturing (HVHF). However, it is unclear if these chemicals, injected into deep shale horizons, reach shallow groundwater aquifers and impact local water quality, either from deep underground injection sites or from the surface or shallow subsurface. Here, we report detectable levels of organic compounds in shallow groundwater samples from private residential wells overlying the Marcellus Shale in northeastern Pennsylvania. Analyses of purgeable and extractable organic compounds from 64 groundwater samples revealed trace levels of volatile organic compounds, well below the Environmental Protection Agency’s maximum contaminant levels, and low levels of both gasoline range (GRO; 0-8 ppb) and diesel range organic compounds (DRO; 0-157 ppb). A compound-specific analysis revealed the presence of bis(2-ethylhexyl)phthalate, which is a disclosed HVHF additive, that was notably absent in a representative geogenic water sample and field blanks. Pairing these analyses with 1) inorganic chemical fingerprinting of deep saline groundwater, 2) characteristic noble gas isotopes, and 3) spatial relationships between active shale gas extraction wells and wells with disclosed environmental health and safety (EHS) violations, we differentiate between a chemical signature associated with naturally occurring saline groundwater and a one associated with alternative anthropogenic routes from the surface (e.g., accidental spills or leaks). The data support a transport mechanism of DRO to groundwater via accidental release of fracturing fluid chemicals derived from the surface rather than subsurface flow of these fluids from the underlying shale formation.The authors thank Duke University’s Pratt School of Engineering and the National Science Foundation’s CBET Grant Number 1336702 and NSF EAGER (EAR-1249255) for financial support.2016-04-1

A multistep process for the dispersal of a Y chromosomal lineage in the Mediterranean area

Tn this work we focus on a microsatellite-defined Y-chromosomal lineage (network 1.2) identified by us and reported in previous studies, whose geographic distribution and antiquity appear to be compatible with the Neolithic spread of farmers. Here, we set network 1.2 in the Y-chromosomal phylogenetic tree, date it with respect to other lineages associated with the same movements by other authors, examine its diversity by means of tri- and tetranucleotide loci and discuss the implications hi reconstructing the spread of this group of chromosomes in the Mediterranean area. Our results define a tripartite phylogeny wit-bin HG 9 (Rosser et al. 2000) with the deepest branching defined by alleles T (Haplogroup Eu 10) or G (Haplogroup Eu9) at M172 (Semino et al. 2000), and a subsequent branching within Eu9 defined by network 1.2. Population distributions of HG 9 and network 1.2 show that their occurrence in the surveyed area is not due to the spread of people from a single parental population but, rather, to a process punctuated by at least two phases. Our data identify the wide area of the Balkans, Aegean and Anatolia as the possible homeland harbouring the largest variation within network 1.2. The use of recently proposed tests based on the stepwise mutation model suggests that its spread was associated to a population expansion, xvith a high rate of male gene flow in the Turkish Greek area

Ionization via Chaos Assisted Tunneling

A simple example of quantum transport in a classically chaotic system is studied. It consists in a single state lying on a regular island (a stable primary resonance island) which may tunnel into a chaotic sea and further escape to infinity via chaotic diffusion. The specific system is realistic : it is the hydrogen atom exposed to either linearly or circularly polarized microwaves. We show that the combination of tunneling followed by chaotic diffusion leads to peculiar statistical fluctuation properties of the energy and the ionization rate, especially to enhanced fluctuations compared to the purely chaotic case. An appropriate random matrix model, whose predictions are analytically derived, describes accurately these statistical properties.Comment: 30 pages, 11 figures, RevTeX and postscript, Physical Review E in pres

Efecto del nivel de proteína en el crecimiento de Goodea atripinnis (Pisces: Goodeidae)

Background. Goodea atripinnis is an omnivorous fish that is only found in the state of Aguascalientes. Its population is being drastically reduced and its survival is considered to be threatened. To avoid its extinction, ex situ breeding programs are being implemented. To implement these programs, however, it is necessary to have feeding plans that allow the nutritional needs of this species to be met. Goals. To evaluate the effects of different protein levels in the diet (25, 30, 35, 40 and 45 % PC) on the growth of G. atripinnis. Methods. A randomized complete-block design with five treatments (protein levels) and 3 aquariums per treatment was used, each aquarium containing 20 fish. The experiment lasted 150 days. Daily feed intake and changes in weight and length of each fish were recorded every 15 days. Results. We found differences in final weight and total weight gain (p &lt;0.05) depended on protein levels. Both the growth rate and the total food intake increased with higher levels of protein. As a result, the feed conversion rate, protein efficiency, and Fulton (K) body condition factor improved. The Gompertz model showed that high protein levels increased standard weight and that the inflection point occurred at the same weight. Conclusions. With higher protein levels, the standard weight is reached at an earlier age, leading to greater development of the fish. &nbsp;Antecedentes. Goodea atripinnis es un pez omnívoro que sólo se localiza en el estado de Aguascalientes y su población se encuentra en estatus de amenaza. Para evitar su extinción se están implementando programas de reproducción ex situ; sin embargo, para lograrlo es necesario contar con planes de alimentación que permitan satisfacer las necesidades nutricionales de la especie. Objetivos. Evaluar los efectos de 5 niveles de proteína (25, 30, 35, 40 y 45% PC) en la dieta, velocidad de crecimiento y parámetros productivos de G. atripinnis. Métodos. Se utilizó un diseño de bloques al azar con 5 tratamientos (niveles de proteína) y 3 acuarios por tratamiento, cada uno contenía 20 peces (peso medio: 0.47 ± 0.02 g). El experimento duró 150 días, durante los cuales se registraron el consumo de alimento diariamente y los cambios en peso y longitud de cada pez cada 15 días. Resultados. Se encontraron diferencias en peso final y ganancia de peso total (p &lt;0.05) entre los niveles de proteína. Tanto la tasa de crecimiento como la ingesta total de alimento aumentaron con el nivel alto de proteína. La tasa de conversión de alimento, la eficiencia proteínica y el factor de condición corporal de Fulton (K) mejoraron. El modelo de Gompertz mostró que los altos niveles de proteína aumentaron el peso estándar y que el punto de inflexión se produce en el mismo peso. Conclusiones. Con los niveles altos de proteína el peso estándar se alcanza a una edad más temprana y permite un mayor desarrollo de los peces

Factor XIIIa-positive dermal dendritic cells and HLA-DR expression in radial versus vertical growth-phase melanomas

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72186/1/j.1600-0560.1998.tb01740.x.pd

Heavy Metals as Risk Factors for Human Diseases - A Bayesian Network Approach

Modern industrial agricultural processes expose human beings to multifactorial environmental pollution including heightened levels of heavy metals. The effects of acute heavy metal exposures at toxic levels are usually known; they are tested for and treated promptly. The effects of low/moderate-level chronic heavy metal exposures are less known as they may be subclinical, and pathogenic effects may only manifest clinically over time under the disguise of a diagnosable disease or miscellaneous symptoms attributed to aging. Consequently, the health impact of low-moderate heavy metal exposure is unlikely to be identified. Furthermore, established heavy metal safety levels often fail to recognize the potential toxic effects on humans. We report in this review what is known about the sub-chronic and chronic effects of exposure to heavy metals, particularly lead, mercury, cadmium, arsenic, and nickel, and we highlight their possible effects in the brain, cardiovascular and endocrine-metabolic systems, and on reproduction