Showing papers by "Southern Illinois University Carbondale published in 2011"

A review of the anthropogenic influence on biogenic secondary organic aerosol

Abstract: . Because of the climate and air quality effects of organic aerosol, it is important to quantify the influence of anthropogenic emissions on the aerosol burden, both globally and regionally, and both in terms of mass and number. Methods exist with which the fractions of organic aerosol resulting directly from anthropogenic and biogenic processes can be estimated. However, anthropogenic emissions can also lead to an enhancement in secondary organic aerosol formation from naturally emitted precursors. We term this enhanced biogenic secondary organic aerosol (eBSOA). Here, we review the mechanisms through which such an effect may occur in the atmosphere and describe a work flow via which it may be quantified, using existing measurement techniques. An examination of published data reveals support for the existence of the enhancement effect.

A new framework for modeling the migration of meandering rivers

Abstract: Many models of river meander migration rely upon a simple formalism, whereby the eroding bank is cut back at a rate that is dictated by the flow, and the depositing bank then migrates passively in response, so as to maintain a constant bankfull channel width. Here a new model is presented, in which separate relations are developed for the migration of the eroding bank and the depositing bank. It is assumed that the eroding bank consists of a layer of fine-grained sediment that is cohesive and/or densely riddled with roots, underlain by a purely noncohesive layer of sand and/or gravel. Following erosion of the noncohesive layer, the cohesive layer fails in the form of slump blocks, which armor the noncohesive layer and thereby moderate the erosion rate. If the slump block material breaks down or is fluvially entrained, the protection it provides for the noncohesive layer diminishes and bank erosion is renewed. Renewed bank erosion, however, rejuvenates slump block armoring. At the depositing bank, it is assumed that all the sediment delivered to the edge of vegetation due to the transverse component of sediment transport is captured by encroaching vegetation, which is not removed by successive floods. Separate equations describing the migration of the eroding and depositing banks are tied to a standard morphodynamic formulation for the evolution of the flow and bed in the central region of the channel. In this model, the river evolves toward maintenance of roughly constant bankfull width as it migrates only to the extent that the eroding bank and depositing bank ‘talk’ to each other via the medium of the morphodynamics of the channel center region. The model allows for both (a) migration for which erosion widens the channel, forcing deposition at the opposite bank, and (b) migration for which deposition narrows the channel forcing erosion at the opposite bank. Copyright © 2010 John Wiley & Sons, Ltd.

Effect of suspect race on officers’ arrest decisions*

Abstract: Many respondents to opinion surveys say that the citizen's race influences how police officers treat the public, yet recent expert social-science panels have declared that research findings are too contradictory to form a conclusion on whether American police are biased against racial minorities. We perform a meta-analysis of quantitative research that estimates the effect of race on the police decision to arrest. Screening nearly 4,500 potential sources, we analyze the results based on 27 independent data sets that generated 40 research reports (both published and unpublished) that permitted an estimate of the effect size of the suspect's race on the probability of arrest. The meta-analysis shows with strong consistency that minority suspects are more likely to be arrested than White suspects. Depending on the method of estimation, the effect size of race varied between 1.32 and 1.52. Converting the race effect size to probabilities shows that compared with the average probability in these studies of a White being arrested (.20), the average probability for a non-White was calculated at .26. The significant race effect persists when taking into account the studies’ variations in research methods and the nature of explanatory models used in the studies. Implications for future research are presented.

Evidence-based guideline update: Treatment of essential tremor Report of the Quality Standards Subcommittee of the American Academy of Neurology

Abstract: Background: This evidence-based guideline is an update of the 2005 American Academy of Neurology practice parameter on the treatment of essential tremor (ET). Methods: A literature review using MEDLINE, EMBASE, Science Citation Index, and CINAHL was performed to identify clinical trials in patients with ET published between 2004 and April 2010. Results and Recommendations: Conclusions and recommendations for the use of propranolol, primidone (Level A, established as effective); alprazolam, atenolol, gabapentin (monotherapy), sotalol, topiramate (Level B, probably effective); nadolol, nimodipine, clonazepam, botulinum toxin A, deep brain stimulation, thalamotomy (Level C, possibly effective); and gamma knife thalamotomy (Level U, insufficient evidence) are unchanged from the previous guideline. Changes to conclusions and recommendations from the previous guideline include the following: 1) levetiracetam and 3,4-diaminopyridine probably do not reduce limb tremor in ET and should not be considered (Level B); 2) flunarizine possibly has no effect in treating limb tremor in ET and may not be considered (Level C); and 3) there is insufficient evidence to support or refute the use of pregabalin, zonisamide, or clozapine as treatment for ET (Level U). Neurology ® 2011;77:1752–1755

G-protein-coupled receptor for short-chain fatty acids suppresses colon cancer.

Abstract: GPR43 is a G-protein-coupled receptor for short-chain fatty acids (SCFAs). Expression of GPR43 is detected in hematopoietic tissues and the large intestine. SCFAs are derived from bacterial fermentation and metabolism of undigested dietary fibers and have been recognized for their cancer prevention activities in the colon. The role of SCFAs, particularly butyrate, in colon cancer therapy has been extensively studied, and its tumor suppressive functions are believed to be due to their intracellular actions, notably inhibition of histone deacetylase. In our study, we show that SCFAs also exert their antitumor effects via receptor GPR43 and that GPR43 is frequently lost in colon cancer cells. Immunohistostaining revealed that GPR43 immunoreactivity was high in normal colon tissues (N = 31) but was markedly reduced or completely lost in most colorectal adenocarcinoma tissues (N = 70) and their corresponding lymph node metastatic adenocarcinomas (N = 38). RT-PCR analysis detected the presence of full length GPR43 mRNA in only one (HT-29) of nine established human colon cancer cell lines. Restoration of GPR43 expression in HCT8 human colonic adenocarcinoma cells induced G0/G1 cell cycle arrest and activated caspases, leading to increased apoptotic cell death after propionate/butyrate treatment. Restored GPR43 expression, coupled with propionate treatment, induced an upregulation of p21 and a decrease in the levels of cyclin D3 and cyclin-dependent kinases (CDKs) 1 and 2, while the CDK4 and CDK6 levels remained unchanged. Our results suggest that GPR43 functions as a tumor suppressor by mediating SCFA-induced cell proliferation inhibition and apoptotic cell death in colon cancer.

Mice with behavioral evidence of tinnitus exhibit dorsal cochlear nucleus hyperactivity because of decreased GABAergic inhibition

Abstract: Tinnitus has been associated with increased spontaneous and evoked activity, increased neural synchrony, and reorganization of tonotopic maps of auditory nuclei. However, the neurotransmitter systems mediating these changes are poorly understood. Here, we developed an in vitro assay that allows us to evaluate the roles of excitation and inhibition in determining the neural correlates of tinnitus. To measure the magnitude and spatial spread of evoked circuit activity, we used flavoprotein autofluorescence (FA) imaging, a metabolic indicator of neuronal activity. We measured FA responses after electrical stimulation of glutamatergic axons in slices containing the dorsal cochlear nucleus, an auditory brainstem nucleus hypothesized to be crucial in the triggering and modulation of tinnitus. FA imaging in dorsal cochlear nucleus brain slices from mice with behavioral evidence of tinnitus (tinnitus mice) revealed enhanced evoked FA response at the site of stimulation and enhanced spatial propagation of FA response to surrounding sites. Blockers of GABAergic inhibition enhanced FA response to a greater extent in control mice than in tinnitus mice. Blockers of excitation decreased FA response to a similar extent in tinnitus and control mice. These findings indicate that auditory circuits in mice with behavioral evidence of tinnitus respond to stimuli in a more robust and spatially distributed manner because of a decrease in GABAergic inhibition.

Elevated expression of TcHMA3 plays a key role in the extreme Cd tolerance in a Cd-hyperaccumulating ecotype of Thlaspi caerulescens

Abstract: Cadmium (Cd) is a highly toxic heavy metal for plants, but several unique Cd-hyperaccumulating plant species are able to accumulate this metal to extraordinary concentrations in the aboveground tissues without showing any toxic symptoms. However, the molecular mechanisms underlying this hypertolerance to Cd are poorly understood. Here we have isolated and functionally characterized an allelic gene, TcHMA3 (heavy metal ATPase 3) from two ecotypes (Ganges and Prayon) of Thlaspi caerulescens contrasting in Cd accumulation and tolerance. The TcHMA3 alleles from the higher (Ganges) and lower Cd-accumulating ecotype (Prayon) share 97.8% identity, and encode a P(1B)-type ATPase. There were no differences in the expression pattern, cell-specificity of protein localization and transport substrate-specificity of TcHMA3 between the two ecotypes. Both alleles were characterized by constitutive expression in the shoot and root, a tonoplast localization of the protein in all leaf cells and specific transport activity for Cd. The only difference between the two ecotypes was the expression level of TcHMA3: Ganges showed a sevenfold higher expression than Prayon, partly caused by a higher copy number. Furthermore, the expression level and localization of TcHMA3 were different from AtHMA3 expression in Arabidopsis. Overexpression of TcHMA3 in Arabidopsis significantly enhanced tolerance to Cd and slightly increased tolerance to Zn, but did not change Co or Pb tolerance. These results indicate that TcHMA3 is a tonoplast-localized transporter highly specific for Cd, which is responsible for sequestration of Cd into the leaf vacuoles, and that a higher expression of this gene is required for Cd hypertolerance in the Cd-hyperaccumulating ecotype of T. caerulescens.

Graphene oxide windows for in situ environmental cell photoelectron spectroscopy

Abstract: Thin graphene oxide windows can be used in X-ray photoelectron spectroscopy of environmental cells by virtue of their transparency to low-energy electrons.

Treating Offenders with Mental Illness: A Research Synthesis

Abstract: The purpose of this research synthesis was to examine treatment effects across studies of the service providers to offenders with mental illness. Meta-analytic techniques were applied to 26 empirical studies obtained from a review of 12,154 research documents. Outcomes of interest in this review included measures of both psychiatric and criminal functioning. Although meta-analytic results are based on a small sample of available studies, results suggest interventions with offenders with mental illness effectively reduced symptoms of distress, improving offender’s ability to cope with their problems, and resulted in improved behavioral markers including institutional adjustment and behavioral functioning. Furthermore, interventions specifically designed to meet the psychiatric and criminal justice needs of offenders with mental illness have shown to produce significant reductions in psychiatric and criminal recidivism. Finally, this review highlighted admission policies and treatment strategies (e.g., use of homework), which produced the most positive benefits. Results of this research synthesis are directly relevant for service providers in both criminal justice and mental health systems (e.g., psychiatric hospitals) as well as community settings by informing treatment strategies for the first time, which are based on empirical evidence. In addition, the implications of these results to policy makers tasked with the responsibility of designating services for this special needs population are highlighted.

Major Mesoamerican droughts of the past millennium

Abstract: [1] Ancient Montezuma baldcypress (Taxodium mucronatum) trees found in Barranca de Amealco, Queretaro, have been used to develop a 1,238-year tree-ring chronology that is correlated with precipitation, temperature, drought indices, and crop yields in central Mexico. This chronology has been used to reconstruct the spring-early summer soil moisture balance over the heartland of the Mesoamerican cultural province, and is the first exactly dated, annually resolved paleoclimatic record for Mesoamerica spanning the Late Classic, Post Classic, Colonial, and modern eras. The reconstruction indicates that the Terminal Classic drought extended into central Mexico, supporting other sedimentary and speleothem evidence for this early 10th century drought in Mesoamerica. The reconstruction also documents severe and sustained drought during the decline of the Toltec state (1149–1167) and during the Spanish conquest of the Aztec state (1514–1539), providing a new precisely dated climate framework for Mesoamerican cultural change.

The Impact of Index Funds in Commodity Futures Markets: A Systems Approach

Abstract: This article addresses the debate regarding the role of index funds in commodity futures markets. Many have argued that index funds are speculators that are responsible for bubbles in commodity futures prices. The argument is based on the premise that the sheer size of index investment can overwhelm the normal functioning of these markets. Importantly, an empirical linkage must be made between commodity index fund positions and prices, or there is no obvious mechanism by which a bubble can form. The authors’ empirical analysis uses new data from the U.S. Commodity Futures Trading Commission contained in the “Disaggregated Commitments of Traders” report. Grangerstyle causality regressions provide no convincing evidence that positions held by swap dealers impact market returns. Surprisingly, the results do suggest that larger commodity index positions are associated with declining market volatility, although these results may be market specific.

Assessing bee species richness in two Mediterranean communities: importance of habitat type and sampling techniques

Abstract: The decline of bees has raised concerns regarding their conservation and the maintenance of ecosystem services they provide to bee-pollinated wild flowers and crops. Although the Mediterranean region is a hotspot for bee species richness, their status remains poorly studied. There is an urgent need for cost-effective, reliable, and unbiased sampling methods that give good bee species richness estimates. This study aims: (a) to assess bee species richness in two common Mediterranean habitat types: semi-natural scrub (phrygana) and managed olive groves; (b) to compare species richness in those systems to that of other biogeographic regions, and (c) to assess whether six different sampling methods (pan traps, variable and standardized transect walks, observation plots and trap nests), previously tested in other European biogeographic regions, are suitable in Mediterranean communities. Eight study sites, four per habitat type, were selected on the island of Lesvos, Greece. The species richness observed was high compared to other habitat types worldwide for which comparable data exist. Pan traps collected the highest proportion of the total bee species richness across all methods at the scale of a study site. Variable and standardized transect walks detected the highest total richness over all eight study sites. Trap nests and observation plots detected only a limited fraction of the bee species richness. To assess the total bee species richness in bee diversity hotspots, such as the studied habitats, we suggest a combination of transect walks conducted by trained bee collectors and pan trap sampling.

Gender, fashion innovativeness and opinion leadership, and need for touch: Effects on multi‐channel choice and touch/non‐touch preference in clothing shopping

Abstract: – This study aims to examine whether gender, fashion innovativeness and opinion leadership, and need for touch have effects on consumers' multi‐channel choice and touch/non‐touch shopping channel preference in clothing shopping., – A survey was conducted using a convenience sample of 123 male and 154 female US college students. Data were analyzed using PASW Statistics 18 and Analysis of Moment Structure (AMOS) 18., – Results showed that participants' multi‐channel choice was influenced only by fashion innovativeness and opinion leadership such that consumers high in fashion innovativeness and opinion leadership tend to use more than one shopping channel. Touch channel preference was influenced by need for touch and multi‐channel choice such that participants who had higher need for touch and used more than one channel for clothing shopping preferred local and non‐local stores. Non‐touch channel preference was influenced by fashion innovativeness and opinion leadership and multi‐channel choice. Regardless of gender, those high in fashion innovativeness and opinion leadership who used more than one channel preferred TV retailers, catalogs, and online stores., – Results cannot be generalized to the larger population of other consumer groups. Future research should include other population groups., – This study is the first to investigate the effects of consumers' gender, fashion innovativeness and opinion leadership, and need for touch on their multi‐channel choice and touch/non‐touch shopping channel preference in clothing shopping.

Short-chain fatty acids induced autophagy serves as an adaptive strategy for retarding mitochondria-mediated apoptotic cell death

Abstract: Short-chain fatty acids (SCFAs) are the major by-products of bacterial fermentation of undigested dietary fibers in the large intestine. SCFAs, mostly propionate and butyrate, inhibit proliferation and induce apoptosis in colon cancer cells, but clinical trials had mixed results regarding the anti-tumor activities of SCFAs. Herein we demonstrate that propionate and butyrate induced autophagy in human colon cancer cells to dampen apoptosis whereas inhibition of autophagy potentiated SCFA induced apoptosis. Colon cancer cells, after propionate treatment, exhibited extensive characteristics of autophagic proteolysis: increased LC3-I to LC3-II conversion, acidic vesicular organelle development, and reduced p62/SQSTM1 expression. Propionate-induced autophagy was associated with decreased mTOR activity and enhanced AMP kinase activity. The elevated AMPKα phosphorylation was associated with cellular ATP depletion and overproduction of reactive oxygen species due to mitochondrial dysfunction involving the induction of MPT and loss of Δψ. In this context, mitochondria biogenesis was initiated to recover cellular energy homeostasis. Importantly, when autophagy was prevented either pharmacologically (3-MA or chloroquine) or genetically (knockdown of ATG5 or ATG7), the colon cancer cells became sensitized toward propionate-induced apoptosis through activation of caspase-7 and caspase-3. The observations indicate that propionate-triggered autophagy serves as an adaptive strategy for retarding mitochondria-mediated apoptotic cell death, whereas application of an autophagy inhibitor (Chloroquine) is expected to enhance the therapeutic efficacy of SCFAs in inducing colon tumor cell apoptosis.

Postnatal Deletion of Wnt7a Inhibits Uterine Gland Morphogenesis and Compromises Adult Fertility in Mice

Abstract: The success of postnatal uterine morphogenesis dictates, in part, the embryotrophic potential and functional capacity of the adult uterus. The definitive role of Wnt7a in postnatal uterine development and adult function requires a conditional knockout, because global deletion disrupts mullerian duct patterning, specification, and cell fate in the fetus. The Wnt7a-null uterus appears to be posteriorized because of developmental defects in the embryo, as evidenced by the stratified luminal epithelium that is normally found in the vagina and the presence of short and uncoiled oviducts. To understand the biological role of WNT7A after birth and allow tissue-selective deletion of Wnt7a, we generated loxP-flanked exon 2 mice and conditionally deleted Wnt7a after birth in the uterus by crossing them with Pgr(Cre) mice. Morphological examination revealed no obvious differences in the vagina, cervix, oviduct, or ovary. The uteri of Wnt7a mutant mice contained no endometrial glands, whereas all other uterine cell types appeared to be normal. Postnatal differentiation of endometrial glands was observed in control mice, but not in mutant mice, between Postnatal Days 3 and 12. Expression of morphoregulatory genes, particularly Foxa2, Hoxa10, Hoxa11, Msx1, and Wnt16, was disrupted in the Wnt7a mutant uteri. Conditional Wnt7a mutant mice were not fertile. Although embryos were present in uteri of mutant mice on Day 3.5 of pregnancy, blastocyst implantation was not observed on Day 5.5. Furthermore, expression of several genes (Foxa2, Lif, Msx1, and Wnt16) was reduced or absent in adult Wnt7a-deleted uteri on Day 3.5 postmating. These results indicate that WNT7A plays a critical role in postnatal uterine gland morphogenesis and function, which are important for blastocyst implantation and fertility in the adult uterus.

Media Health Literacy (MHL): development and measurement of the concept among adolescents

Abstract: Increasing media use among adolescents and its significant influence on health behavior warrants in-depth understanding of their response to media content. This study developed the concept and tested a model of Media Health Literacy (MHL), examined its association with personal/socio-demographic determinants and reported sources of health information, while analyzing its role in promoting empowerment and health behavior (cigarette/water-pipe smoking, nutritional/dieting habits, physical/sedentary activity, safety/injury behaviors and sexual behavior). The school-based study included a representative sample of 1316 Israeli adolescents, grades 7, 9 and 11, using qualitative and quantitative instruments to develop the new measure. The results showed that the MHL measure is highly scalable (0.80) includes four sequenced categories: identification/recognition, critical evaluation of health content in media, perceived influence on adolescents and intended action/reaction. Multivariate analysis showed that MHL was significantly higher among girls (β = 1.25, P < 0.001), adolescents whose mothers had higher education (β = 0.16, P = 0.04), who report more adult/interpersonal sources of health information (β = 0.23, P < 0.01) and was positively associated with health empowerment (β = 0.36, P < 0.0005) and health behavior (β = 0.03, P = 0.05). The findings suggest that as a determinant of adolescent health behavior, MHL identifies groups at risk and may provide a basis for health promotion among youth.

Physical Basis for Quasi-Universal Relationships Describing Bankfull Hydraulic Geometry of Sand-Bed Rivers

Abstract: Empirical data indicate that hydraulic geometry relationships for single-thread sand-bed rivers (i.e., rivers with median bed-material size between 0.062 and 0.50 mm) can be delineated such that bankfull width, bankfull depth, and channel slope are related in consistent ways to bankfull discharge. Such relationships ought to be the external expression of physical relationships intrinsic to sand-bed river dynamics. In this study, a back-calculation is performed to identify parameters (exponents and coefficients) for three relationships taken to be intrinsic to sand-bed rivers: (1) a generalized Manning-Strickler resistance relationship; (2) a relationship for channel-forming Shields number; and (3) a relationship for sand yield at bankfull flow. To back-calculate parameters for the physical relationships, first the hydraulic geometry relationships are expressed in suitable dimensionless form. Second, the physical relationships are expressed with coefficients and exponents that are analytically related to p...

Economic Inequality, Relative Power, and Religiosity*

Abstract: Objective. What effect does the extent of economic inequality within a country have on the religiosity of the people who live there? As inequality increases, does religion serve primarily as a source of comfort for the deprived and impoverished or as a tool of social control for the rich and powerful? Methods. This article examines these questions with two complementary analyses of inequality and religiosity: a multilevel analysis of countries around the world over two decades and a time-series analysis of the United States over a half-century. Results. Economic inequality has a strong positive effect on the religiosity of all members of a society regardless of income. Conclusions. These results support relative power theory, which maintains that greater inequality yields more religiosity by increasing the degree to which wealthy people are attracted to religion and have the power to shape the attitudes and beliefs of those with fewer means.

Climatic modifiers of the response to nitrogen deposition in peat-forming Sphagnum mosses: a meta-analysis

Abstract: Summary • Peatlands in the northern hemisphere have accumulated more atmospheric carbon (C) during the Holocene than any other terrestrial ecosystem, making peatlands long-term C sinks of global importance. Projected increases in nitrogen (N) deposition and temperature make future accumulation rates uncertain. • Here, we assessed the impact of N deposition on peatland C sequestration potential by investigating the effects of experimental N addition on Sphagnum moss. We employed meta-regressions to the results of 107 field experiments, accounting for sampling dependence in the data. • We found that high N loading (comprising N application rate, experiment duration, background N deposition) depressed Sphagnum production relative to untreated controls. The interactive effects of presence of competitive vascular plants and high tissue N concentrations indicated intensified biotic interactions and altered nutrient stochiometry as mechanisms underlying the detrimental N effects. Importantly, a higher summer temperature (mean for July) and increased

Isolation of Sertoli, Leydig, and spermatogenic cells from the mouse testis.

Abstract: A thorough understanding of the events during mammalian spermatogenesis requires studying specific molecular signatures of individual testicular cell populations as well as their interaction in co-cultures. However, most purification techniques to isolate specific testicular cell populations are time-consuming, require large numbers of animals, and/or are only able to isolate a few cell types. Here we describe a cost-effective and timesaving approach that uses a single protocol to enrich multiple testicular cell populations (Sertoli, Leydig, and several spermatogenic cell populations) from as few as one mouse. Our protocol combines rigorous enzymatic digestion of seminiferous tubules with counter-current centrifugal elutriation, yielding specific testicular cell populations with >80%-95% purity.

Religion and Scientific Literacy in the United States

Abstract: Objective This study examines how commitment to sectarian Protestant religious groups and fundamentalist beliefs in the inerrancy of the Bible influence basic scientific literacy. Methods I analyze data from the 2006 General Social Survey (N = 1,780), which included a 13-point examination of scientific facts and reasoning. Ordinary least squares regression models are estimated to determine the impact of religious affiliations and beliefs net of other control variables such as race, gender, education, income, region, and rural residence. Results Analyses show that sectarian Protestants, Catholics, and people with fundamentalist beliefs in the inerrancy of the Bible have significantly lower levels of scientific literacy when compared with secular Americans. Religious differences are identifiable in multivariate analyses controlling for other demographic factors. Conclusions Religion plays a sizeable role in the low levels of scientific literacy found in the United States, and the negative impact of religious factors is more substantial than gender, race, or income.