bluuebunny/crossref_metadata_2025 huggingface dataset:
Patterns of changing knowledge orders: insights from German and British labour market policy
Authors: Krapp Max-Christopher , Pannowitsch Sylvia
Published: November 2015

Following an interpretative approach this paper investigates the role of knowledge orders, understood as settings which attribute relevance to specific expertise. The changing patterns of incorporation of expertise in policy formulation as well as public justification are analysed for German and British labour market policy. From a comparative perspective it can be observed that the processes of transformation differ with regard to relevant drivers and measures. In both cases approaches of evidence-based policy making have gained importance. Nevertheless we argue that a changing knowledge order does not necessarily affect policy formulation and public justification in analogous ways.
RELAÇÕES ENTRE GESTÃO DO CONHECIMENTO, INOVAÇÃO E FATURAMENTO: UM ESTUDO EM EMPRESAS GRADUADAS NO ESTADO DO PARANÁ
Authors: Bezerra Cicero Aparecido , Quandt Carlos Olavo
Published: November 2015

As incubadoras de empresas de base tecnológica (EBTs) têm graduado organizações a partir de processos baseados em inovação e Gestão do Conhecimento (GC). Uma vez identificada a carência de pesquisas que abordam elementos de GC e relacionam o uso de recursos de conhecimento em ETBs, o presente estudo busca encontrar associação entre a eficácia de práticas de GC e os investimentos em elementos de inovação e faturamento de EBTs graduadas por incubadoras. Trata-se de um estudo exploratório que empregou análises multi e bivariadas, que identificaram agrupamentos formados por empresas com características semelhantes em relação à eficácia da adoção de práticas de GC, investimentos em elementos associados à inovação e faturamento. O estudo foi realizado junto a 52 EBTs graduadas em incubadoras do estado do Paraná. Os resultados mostram que empresas que apresentaram maior faturamento também são aquelas que percebem maior eficácia nas práticas de GC adotadas e que mais investem em elementos de inovação. Por outro lado, as empresas classificadas nas faixas de menor faturamento se agrupam apenas pelas menores percepções de eficácia das práticas de GC. Além disto, evidencia-se que os percentuais do faturamento investidos em elementos de inovação são maiores nas micro e médias empresas – as organizações de pequeno porte demonstraram investir menos em inovação do que aquelas classificadas nas demais faixas de faturamento.
Existence and multiplicity results for the fractional Laplacian in bounded domains
Authors: Mugnai Dimitri , Pagliardini Dayana
Published: November 2015

In this paper, first we study existence results for a linearly perturbed elliptic problem driven by the fractional Laplacian. Then, we show a multiplicity result when the perturbation parameter is close to the eigenvalues. This latter result is obtained by exploiting the topological structure of the sublevels of the associated functional, which permits to apply a critical point theorem of mixed nature due to Marino and Saccon.
Application of S-transform to signal analysis
Authors: Szymczyk Piotr , Szymczyk Magdalena
Published: November 2015

This paper presents opportunities of signal analysis using S-transform. Images of the module and the angle of S-transform show the results. These images may be used as models to compare with unknown signals and to detect patterns and anomalies, even in very sophisticated signals.
Likelihood Inference for the Lifetime Performance Index under Progressive Type-II Censoring
Authors: Laumen Benjamin , Cramer Erhard
Published: November 2015

Likelihood inference for the lifetime performance index CL
is discussed in the presence of progressive censoring. We illustrate that many results available in the literature can be traced back to the exponential case using appropriate transformations of the data. Further, we present procedures to compute the MLE of CL
under the assumption of gamma distributed lifetimes. The results are illustrated by a simulation study and applied to a data set.
Knowledge and perception of young adults in Nigeria on effectiveness of condom use in prevention of sexually transmitted infections
Authors: Anyanwu Philip Emeka , Fulton John
Published: November 2015

Background:

Although sexually transmitted infections (STIs) are a global health problem affecting every region of the world, the higher prevalence and mortality rate of STIs in developing countries of the world, like Nigeria, make them serious public health issues in this region.

Objective:

The aim of this study is to assess the knowledge and perception of young adults in Nigeria on the role of condom (both male and female condoms) as a preventive measure against STIs during heterosexual and homosexual intercourse.

Materials and methods:

Data was collected from participants selected from the northern and southern Nigeria using self-administered questionnaire specifically designed for this study.

Results:

Knowledge of condom efficacy in STI prevention was satisfactory. However, knowledge and practice of the correct use of condom was poor. Only 47.1% of the 102 participants in this study reported correct condom use of wearing condoms before staring intercourse and removing condoms after ejaculation. As a strategy to include the experiences, knowledge and perception of men who have sex with men, this study asked the question on condom use during anal sex. Only 24.4% of the male participants indicated they have never had anal sex while for females, the percentage was more than half (53.5%). Condom use during anal sex was low with only 20.6% of participants reporting condom use during anal sex. Negative perceptions about condom use – such as that condom use promotes sexual promiscuity, and not using condoms with steady sexual partners – were significant in this study. Also, condom use errors were common in this study.

Conclusion:

There is a wide gap in knowledge of correct condom use in this population. There is need for interventions that address the issue of condom use during anal and same-sex sexual intercourse in this population.
CFD Modelling of a Hollow Fibre Membrane for CO2 Removal by Aqueous Amine Solutions of MEA, DEA and MDEA
Authors: Gilassi Sina , Rahmanian Nejat
Published: November 2015

A mass transfer model was developed to capture CO2 from a gas mixture in hollow fibre membrane contactors under laminar flow conditions. The axial and radial diffusions through membrane and convection in tube and shell sides with chemical reaction were investigated. COMSOL software was used to numerically solve a system of non-linear equations with boundary conditions by use of the finite element method. Three different amine solutions of monoethanolamine (MEA), diethanolamine (DEA) and n-methyldiethanolamine (MDEA) were chosen as absorbent in lumen to consider the mass transfer rate of CO2 and its removal efficiency. The modelling results were compared with experimental data available in the literature and a good agreement was observed. The CFD results revealed that MEA had the best performance for CO2 removal as compared to DEA and MDEA under various operating conditions due to the different CO2 loading factor of absorbents. Furthermore, efficiency of CO2 removal was highly dependent on the absorbent concentration and flow rate, increasing of the gas flow rate caused a reduction in gas residence time in the shell and consequently declined CO2 mass transfer. The modelling results showed the effect of absorbent concentration on the CO2 mass transfer was improved due to availability of absorbent reactants at the gas-liquid interface.
One-phase Stefan problem with temperature-dependent thermal conductivity and
a boundary condition of Robin type
Authors: Briozzo Adriana C. , Natale María Fernanda
Published: November 2015

We study a one-phase Stefan problem for a semi-infinite material with
temperature-dependent thermal conductivity with a boundary
condition of Robin type at the fixed face x = 0. We obtain sufficient
conditions for data in order to have a parametric representation of the
solution of similarity type for t ≥ t
0 > 0 with t
0 an arbitrary positive time. This explicit solution is obtained through the
unique solution of an integral equation with the time as a parameter.
Additive Nonparametric Instrumental Regressions: A Guide to Implementation
Authors: Centorrino Samuele , Feve Frederique , Florens Jean-Pierre
Published: November 2015

We present a review on the implementation of regularization methods for the estimation of additive nonparametric regression models with instrumental variables. We consider various versions of Tikhonov, Landweber-Fridman and Sieve (Petrov-Galerkin) regularization. We review data-driven techniques for the sequential choice of the smoothing and the regularization parameters. Through Monte Carlo simulations, we discuss the finite sample properties of each regularization method for different smoothness properties of the regression function. Finally, we present an application to the estimation of the Engel curve for food in a sample of rural households in Pakistan, where a partially linear specification is described that allows one to embed other exogenous covariates.
Nonclassical Symmetry Analysis of Heated Two-Dimensional Flow Problems
Authors: Naeem Imran , Naz Rehana , Khan Muhammad Danish
Published: November 2015

This article analyses the nonclassical symmetries and group invariant solution of boundary layer equations for two-dimensional heated flows. First, we derive the nonclassical symmetry determining equations with the aid of the computer package SADE. We solve these equations directly to obtain nonclassical symmetries. We follow standard procedure of computing nonclassical symmetries and consider two different scenarios, ξ
1≠0 and ξ
1=0, ξ
2≠0. Several nonclassical symmetries are reported for both scenarios. Furthermore, numerous group invariant solutions for nonclassical symmetries are derived. The similarity variables associated with each nonclassical symmetry are computed. The similarity variables reduce the system of partial differential equations (PDEs) to a system of ordinary differential equations (ODEs) in terms of similarity variables. The reduced system of ODEs are solved to obtain group invariant solution for governing boundary layer equations for two-dimensional heated flow problems. We successfully formulate a physical problem of heat transfer analysis for fluid flow over a linearly stretching porous plat and, with suitable boundary conditions, we solve this problem.
A Serotonin Circuit Acts as an Environmental Sensor to Mediate Midline Axon Crossing through EphrinB2
Authors: Xing Lingyan , Son Jong-Hyun , Stevenson Tamara J. , Lillesaar Christina , Bally-Cuif Laure , Dahl Tiffanie , Bonkowsky Joshua L.
Published: November 2015

Modulation of connectivity formation in the developing brain in response to external stimuli is poorly understood. Here, we show that the raphe nucleus and its serotonergic projections regulate pathfinding of commissural axons in zebrafish. We found that the raphe neurons extend projections toward midline-crossing axons and that when serotonergic signaling is blocked by pharmacological inhibition or by raphe neuron ablation, commissural pathfinding is disrupted. We demonstrate that the serotonin receptorhtr2ais expressed on these commissural axons and that genetic knock-down ofhtr2adisrupts crossing. We further show that knock-down ofhtr2aor ablation of the raphe neurons increases ephrinB2a protein levels in commissural axons. AnephrinB2amutant can rescue midline crossing when serotonergic signaling is blocked. Furthermore, we found that regulation of serotonin expression in the raphe neurons is modulated in response to the developmental environment. Hypoxia causes the raphe to decrease serotonin levels, leading to a reduction in midline crossing. Increasing serotonin in the setting of hypoxia restored midline crossing. Our findings demonstrate an instructive role for serotonin in axon guidance acting throughephrinB2aand reveal a novel mechanism for developmental interpretation of the environmental milieu in the generation of mature neural circuitry.

SIGNIFICANCE STATEMENTWe show here that serotonin has a novel role in regulating connectivity in response to the developmental environment. We demonstrate that serotonergic projections from raphe neurons regulate pathfinding of crossing axons. The neurons modulate their serotonin levels, and thus alter crossing, in response to the developmental environment including hypoxia. The findings suggest that modification of the serotonergic system by early exposures may contribute to permanent CNS connectivity alterations. This has important ramifications because of the association between premature birth and accompanying hypoxia, and increased risk of autism and evidence associatingin uteroexposure to some antidepressants and neurodevelopmental disorders. Finally, this work demonstrates that the vertebrate CNS can modulate its connectivity in response to the external environment.
Dopamine D1 Binding Potential Predicts Fusiform BOLD Activity during Face-Recognition Performance
Authors: Rypma Bart , Fischer Håkan , Rieckmann Anna , Hubbard Nicholas A. , Nyberg Lars , Bäckman Lars
Published: November 2015

The importance of face memory in humans and primates is well established, but little is known about the neurotransmitter systems involved in face recognition. We tested the hypothesis that face recognition is linked to dopamine (DA) activity in fusiform gyrus (FFG). DA availability was assessed by measuring D1 binding potential (BP) during rest using PET. We further assessed blood-oxygen-level-dependent (BOLD) signal change while subjects performed a face-recognition task during fMRI scanning. There was a strong association between D1 BP and BOLD activity in FFG, whereas D1 BP in striatal and other extrastriatal regions were unrelated to neural activity in FFG. These results suggest that D1 BP locally modulates FFG function during face recognition. Observed relationships among D1 BP, BOLD activity, and face-recognition performance further suggest that D1 receptors place constraints on the responsiveness of FFG neurons.

SIGNIFICANCE STATEMENTThe importance of face memory in humans and primates is well established, but little is known about the neurotransmitter systems involved in face recognition. Our work shows a role for a specific neurotransmitter system in face memory.
Cell-Permeable Peptide Targeting the Nrf2–Keap1 Interaction: A Potential Novel Therapy for Global Cerebral Ischemia
Authors: Tu Jingyi , Zhang Xi , Zhu Ying , Dai Yongxin , Li Ning , Yang Fang , Zhang Quanguang , Brann Darrell W. , Wang Ruimin
Published: November 2015

The current study examined efficacy of a small Tat (trans-activator of transcription)-conjugated peptide activator of the Nrf2 (nuclear factor-E2-related factor-2) antioxidant/cell-defense pathway as a potential injury-specific, novel neuroprotectant against global cerebral ischemia (GCI). A competitive peptide, DEETGE-CAL-Tat, was designed to facilitate Nrf2 activation by disrupting interaction of Nrf2 with Keap1 (kelch-like ECH-associated protein 1), a protein that sequesters Nrf2 in the cytoplasm and thereby inactivates it. The DEETGE-CAL-Tat peptide contained the critical sequence DEETGE for the Nrf2–Keap1 interaction, the cell transduction domain of the HIV-Tat protein, and the cleavage sequence of calpain, which is sensitive to Ca2+increase and allows injury-specific activation of Nrf2. Using an animal model of GCI, we demonstrated that pretreatment with the DEETGE-CAL-Tat peptide markedly decreased Nrf2 interaction with Keap1 in the rat hippocampal CA1 region after GCI, and enhanced Nrf2 nuclear translocation and DNA binding. The DEETGE-CAL-Tat peptide also induced Nrf2 antioxidant/cytoprotective target genes, reduced oxidative stress, and induced strong neuroprotection and marked preservation of hippocampal-dependent cognitive function after GCI. These effects were specific as control peptides lacked neuroprotective ability. Intriguingly, the DEETGE-CAL-Tat peptide effects were also injury specific, as it had no effect upon neuronal survival or cognitive performance in sham nonischemic animals. Of significant interest, peripheral, postischemia administration of the DEETGE-CAL-Tat peptide from days 1–9 after GCI also induced robust neuroprotection and strongly preserved hippocampal-dependent cognitive function. Based on its robust neuroprotective and cognitive-preserving effects, and its unique injury-specific activation properties, the DEETGE-CAL-Tat peptide represents a novel, and potentially promising new therapeutic modality for the treatment of GCI.

SIGNIFICANCE STATEMENTThe current study demonstrates that DEETGE-CAL-Tat, a novel peptide activator of a key antioxidant gene transcription pathway in the hippocampus after global cerebral ischemia, can exert robust neuroprotection and preservation of cognitive function. A unique feature of the peptide is that its beneficial effects are injury specific. This feature is attractive as it targets drug activation specifically in the site of injury, and likely would lead to a reduction of undesirable side effects if translatable to the clinic. Due to its injury-specific activation, robust neuroprotection, and cognitive-preserving effects, this novel peptide may represent a much-needed therapeutic advance that could have efficacy in the treatment of global cerebral ischemia.
microRNA-33 Regulates ApoE Lipidation and Amyloid-β Metabolism in the Brain
Authors: Kim Jaekwang , Yoon Hyejin , Horie Takahiro , Burchett Jack M. , Restivo Jessica L. , Rotllan Noemi , Ramírez Cristina M. , Verghese Philip B. , Ihara Masafumi , Hoe Hyang-Sook , Esau Christine , Fernández-Hernando Carlos , Holtzman David M. , Cirrito John R. , Ono Koh , Kim Jungsu
Published: November 2015

Dysregulation of amyloid-β (Aβ) metabolism is critical for Alzheimer's disease (AD) pathogenesis. Mounting evidence suggests that apolipoprotein E (ApoE) is involved in Aβ metabolism. ATP-binding cassette transporter A1 (ABCA1) is a key regulator of ApoE lipidation, which affects Aβ levels. Therefore, identifying regulatory mechanisms of ABCA1 expression in the brain may provide new therapeutic targets for AD. Here, we demonstrate that microRNA-33 (miR-33) regulates ABCA1 and Aβ levels in the brain. Overexpression of miR-33 impaired cellular cholesterol efflux and dramatically increased extracellular Aβ levels by promoting Aβ secretion and impairing Aβ clearance in neural cells. In contrast, genetic deletion ofmir-33in mice dramatically increased ABCA1 levels and ApoE lipidation, but it decreased endogenous Aβ levels in cortex. Most importantly, pharmacological inhibition of miR-33 via antisense oligonucleotide specifically in the brain markedly decreased Aβ levels in cortex ofAPP/PS1mice, representing a potential therapeutic strategy for AD.

SIGNIFICANCE STATEMENTBrain lipid metabolism, in particular Apolipoprotein E (ApoE) lipidation, is critical to Aβ metabolism and Alzheimer's disease (AD). Brain lipid metabolism is largely separated from the periphery due to blood–brain barrier and different repertoire of lipoproteins. Therefore, identifying the novel regulatory mechanism of brain lipid metabolism may provide a new therapeutic strategy for AD. Although there have been studies on brain lipid metabolism, its regulation, in particular by microRNAs, is relatively unknown. Here, we demonstrate that inhibition of microRNA-33 increases lipidation of brain ApoE and reduces Aβ levels by inducing ABCA1. We provide a unique approach for AD therapeutics to increase ApoE lipidation and reduce Aβ levels via pharmacological inhibition of microRNAin vivo.
Irregular Speech Rate Dissociates Auditory Cortical Entrainment, Evoked Responses, and Frontal Alpha
Authors: Kayser Stephanie J. , Ince Robin A.A. , Gross Joachim , Kayser Christoph
Published: November 2015

The entrainment of slow rhythmic auditory cortical activity to the temporal regularities in speech is considered to be a central mechanism underlying auditory perception. Previous work has shown that entrainment is reduced when the quality of the acoustic input is degraded, but has also linked rhythmic activity at similar time scales to the encoding of temporal expectations. To understand these bottom-up and top-down contributions to rhythmic entrainment, we manipulated the temporal predictive structure of speech by parametrically altering the distribution of pauses between syllables or words, thereby rendering the local speech rate irregular while preserving intelligibility and the envelope fluctuations of the acoustic signal. Recording EEG activity in human participants, we found that this manipulation did not alter neural processes reflecting the encoding of individual sound transients, such as evoked potentials. However, the manipulation significantly reduced the fidelity of auditory delta (but not theta) band entrainment to the speech envelope. It also reduced left frontal alpha power and this alpha reduction was predictive of the reduced delta entrainment across participants. Our results show that rhythmic auditory entrainment in delta and theta bands reflect functionally distinct processes. Furthermore, they reveal that delta entrainment is under top-down control and likely reflects prefrontal processes that are sensitive to acoustical regularities rather than the bottom-up encoding of acoustic features.

SIGNIFICANCE STATEMENTThe entrainment of rhythmic auditory cortical activity to the speech envelope is considered to be critical for hearing. Previous work has proposed divergent views in which entrainment reflects either early evoked responses related to sound encoding or high-level processes related to expectation or cognitive selection. Using a manipulation of speech rate, we dissociated auditory entrainment at different time scales. Specifically, our results suggest that delta entrainment is controlled by frontal alpha mechanisms and thus support the notion that rhythmic auditory cortical entrainment is shaped by top-down mechanisms.
Human Auditory Cortex Neurochemistry Reflects the Presence and Severity of Tinnitus
Authors: Sedley William , Parikh Jehill , Edden Richard A.E. , Tait Valerie , Blamire Andrew , Griffiths Timothy D.
Published: November 2015

It is not known why tinnitus occurs in some cases of hearing damage but not others. Abnormalities of excitation–inhibition balance could influence whether tinnitus develops and its severity if it does. Animal models of hearing damage, which also produce tinnitus based on behavioral evidence, have identified abnormalities of GABAergic inhibition, both cortically and subcortically. However, the precise relationships of GABA inhibitory changes to tinnitus itself, as opposed to other consequences of hearing damage, remain uncertain. Here, we used magnetic resonance spectroscopy to non-invasively quantify GABA in the left (LAC) and right (RAC) auditory cortices of a group of 14 patients with lateralized tinnitus (eight left ear) and 14 controls matched for age, sex, and hearing. We also explored the potential relationships with other brain metabolites (i.e., choline,N-acetylaspartate, and creatine). The presence of tinnitus was associated with a reduction in auditory cortex GABA concentration. Regardless of tinnitus laterality,post hoctesting indicated reductions that were significant in RAC and nonsignificant in LAC. Tinnitus severity and hearing loss were correlated positively with RAC choline but not GABA. We discuss the results in the context of current models of tinnitus and methodological constraints.

SIGNIFICANCE STATEMENTPermanently affecting one in seven adults, tinnitus lacks both widely effective treatments and adequate understanding of its brain mechanisms. Existing animal models represent tinnitus that may not be distinguishable from homeostatic responses to the auditory insults used to induce it. Human studies can be well controlled in this regard but are usually not (with few even matching control subjects for hearing loss) and are limited in scope as a result of relying solely on non-invasive recording techniques. Here, we exploit recent advances in non-invasive spectroscopic techniques to establish, in a human study tightly controlled for hearing loss and hyperacusis, that tinnitus is associated with a significant reduction in auditory cortex GABA concentration, which has implications for understanding and treatment of the condition.
Memory Meets Control in Hippocampal and Striatal Binding of Stimuli, Responses, and Attentional Control States
Authors: Jiang Jiefeng , Brashier Nadia M. , Egner Tobias
Published: November 2015

The human brain encodes experience in an integrative fashion by binding together the various features of an event (i.e., stimuli and responses) into memory “event files.” A subsequent reoccurrence of an event feature can then cue the retrieval of the memory file to “prime” cognition and action. Intriguingly, recent behavioral studies indicate that, in addition to linking concrete stimulus and response features, event coding may also incorporate more abstract, “internal” event features such as attentional control states. In the present study, we used fMRI in healthy human volunteers to determine the neural mechanisms supporting this type of holistic event binding. Specifically, we combined fMRI with a task protocol that dissociated the expression of event feature-binding effects pertaining to concrete stimulus and response features, stimulus categories, and attentional control demands. Using multivariate neural pattern classification, we show that the hippocampus and putamen integrate event attributes across all of these levels in conjunction with other regions representing concrete-feature-selective (primarily visual cortex), category-selective (posterior frontal cortex), and control demand-selective (insula, caudate, anterior cingulate, and parietal cortex) event information. Together, these results suggest that the hippocampus and putamen are involved in binding together holistic event memories that link physical stimulus and response characteristics with internal representations of stimulus categories and attentional control states. These bindings then presumably afford shortcuts to adaptive information processing and response selection in the face of recurring events.

SIGNIFICANCE STATEMENTMemory binds together the different features of our experience, such as an observed stimulus and concurrent motor responses, into so-called event files. Recent behavioral studies suggest that the observer's internal attentional state might also become integrated into the event memory. Here, we used fMRI to determine the brain areas responsible for binding together event information pertaining to concrete stimulus and response features, stimulus categories, and internal attentional control states. We found that neural signals in the hippocampus and putamen contained information about all of these event attributes and could predict behavioral priming effects stemming from these features. Therefore, medial temporal lobe and dorsal striatum structures appear to be involved in binding internal control states to event memories.
Sustained Arginase 1 Expression Modulates Pathological Tau Deposits in a Mouse Model of Tauopathy
Authors: Hunt Jerry B. , Nash Kevin R. , Placides Devon , Moran Peter , Selenica Maj-Linda B. , Abuqalbeen Firas , Ratnasamy Kevin , Slouha Nina , Rodriguez-Ospina Santiago , Savlia Miloni , Ranaweera Yashobha , Reid Patrick , Dickey Chad A. , Uricia Rodrigo , Yang Clement G.Y. , Sandusky Leslie A. , Gordon Marcia N. , Morgan Dave , Lee Daniel C.
Published: November 2015

Tau accumulation remains one of the closest correlates of neuronal loss in Alzheimer's disease. In addition, tau associates with several other neurodegenerative diseases, collectively known as tauopathies, in which clinical phenotypes manifest as cognitive impairment, behavioral disturbances, and motor impairment. Polyamines act as bivalent regulators of cellular function and are involved in numerous biological processes. The regulation of the polyamines system can become dysfunctional during disease states. Arginase 1 (Arg1) and nitric oxide synthases compete forl-arginine to produce either polyamines or nitric oxide, respectively. Herein, we show that overexpression of Arg1 using adeno-associated virus (AAV) in the CNS of rTg4510 tau transgenic mice significantly reduced phospho-tau species and tangle pathology. Sustained Arg1 overexpression decreased several kinases capable of phosphorylating tau, decreased inflammation, and modulated changes in the mammalian target of rapamycin and related proteins, suggesting activation of autophagy. Arg1 overexpression also mitigated hippocampal atrophy in tau transgenic mice. Conversely, conditional deletion of Arg1 in myeloid cells resulted in increased tau accumulation relative to Arg1-sufficient mice after transduction with a recombinant AAV–tau construct. These data suggest that Arg1 and the polyamine pathway may offer novel therapeutic targets for tauopathies.
REST Regulates Non–Cell-Autonomous Neuronal Differentiation and Maturation of Neural Progenitor Cells via Secretogranin II
Authors: Kim Hyung Joon , Denli Ahmet M. , Wright Rebecca , Baul Tithi D. , Clemenson Gregory D. , Morcos Ari S. , Zhao Chunmei , Schafer Simon T. , Gage Fred H. , Kagalwala Mohamedi N.
Published: November 2015

RE-1 silencing transcription factor (REST), a master negative regulator of neuronal differentiation, controls neurogenesis by preventing the differentiation of neural stem cells. Here we focused on the role of REST in the early steps of differentiation and maturation of adult hippocampal progenitors (AHPs). REST knockdown promoted differentiation and affected the maturation of rat AHPs. Surprisingly, REST knockdown cells enhanced the differentiation of neighboring wild-type AHPs, suggesting that REST may play a non–cell-autonomous role. Gene expression analysis identified Secretogranin II (Scg2) as the major secreted REST target responsible for the non–cell-autonomous phenotype. Loss-of-function ofScg2inhibited differentiationin vitro, and exogenous SCG2 partially rescued this phenotype. Knockdown of REST in neural progenitors in mice led to precocious maturation into neurons at the expense of mushroom spinesin vivo. In summary, we found that, in addition to its cell-autonomous function, REST regulates differentiation and maturation of AHPs non–cell-autonomously via SCG2.

SIGNIFICANCE STATEMENTOur results reveal that REST regulates differentiation and maturation of neural progenitor cellsin vitroby orchestrating both cell-intrinsic and non–cell-autonomous factors and thatScg2is a major secretory target of REST with a differentiation-enhancing activity in a paracrine manner.In vivo, REST depletion causes accelerated differentiation of newborn neurons at the expense of spine defects, suggesting a potential role for REST in the timing of the maturation of granule neurons.
Antisense Transcription of Retrotransposons in Drosophila: An Origin of Endogenous Small Interfering RNA Precursors
Authors: Russo Joseph , Harrington Andrew W , Steiniger Mindy
Published: November 2015

Movement of transposons causes insertions, deletions, and chromosomal rearrangements potentially leading to premature lethality in Drosophila melanogaster. To repress these elements and combat genomic instability, eukaryotes have evolved several small RNA-mediated defense mechanisms. Specifically, in Drosophila somatic cells, endogenous small interfering (esi)RNAs suppress retrotransposon mobility. EsiRNAs are produced by Dicer-2 processing of double-stranded RNA precursors, yet the origins of these precursors are unknown. We show that most transposon families are transcribed in both the sense (S) and antisense (AS) direction in Dmel-2 cells. LTR retrotransposons Dm297, mdg1, and blood, and non-LTR retrotransposons juan and jockey transcripts, are generated from intraelement transcription start sites with canonical RNA polymerase II promoters. We also determined that retrotransposon antisense transcripts are less polyadenylated than sense. RNA-seq and small RNA-seq revealed that Dicer-2 RNA interference (RNAi) depletion causes a decrease in the number of esiRNAs mapping to retrotransposons and an increase in expression of both S and AS retrotransposon transcripts. These data support a model in which double-stranded RNA precursors are derived from convergent transcription and processed by Dicer-2 into esiRNAs that silence both sense and antisense retrotransposon transcripts. Reduction of sense retrotransposon transcripts potentially lowers element-specific protein levels to prevent transposition. This mechanism preserves genomic integrity and is especially important for Drosophila fitness because mobile genetic elements are highly active.
Lista con anotaciones de las Angiospermas de la Reserva Biológica Alberto Brenes (microcuencas de lo Ríos San Lorenzo y San Lorencito),Costa Rica
Authors: Gómez-Laurito Jorge , Ortiz Rodolfo
Published: November 2015

La Reserva Biológica Alberto Brenes está localizada al noroeste de Costa Rica, en la vertiente Caribe, con elevaciones que van de 800 a 1500 m. Esta área está expuesta a altas precipitaciones durante todo el año (4500 mm) con pocas lluvias de febrero a abril. Con temperaturas moderadas debido a la ele- vación, la cobertura de nubes y la alta precipitación dan como resultado un bosque tropical húmedo de pre- montano, que también se puede ubicar como un bosque nuboso de transición entre el bosque nuboso de montano, que se halla en elevaciones más altas, y el bosque tropical húmedo de elevaciones más bajas. Así, por su ámbito altitudinal intermedio, los bosques de la Reserva Biológica A. M. Brenes poseen una diversi- dad notable de especies que pertenecen a zonas bajas y altas de Costa Rica. Se presenta aquí una lista con anotaciones de las plantas de la Reserva distribuidas en 137 familias de angiospermas, representadas por 483 géneros y 1294 especies. Las familias con mayor número de especies son Araceae (50), Gesneriaceae (52), Melastomataceae (61), Orchidaceae (208), Rubiaceae (75) y Solanaceae (37). Los géneros de mono- cotiledóneas con mayor número de especies son Pleurothallis (34), Anthurium (25) y Maxillaria (23). Los géneros de dicotiledóneas con mayor número de especies son Peperomia (33), Piper (23), Miconia (16), Ocotea (21) y Psychotria s.s. (15). Las siguientes especies fueron descritas de la Reserva A.M. Brenes como nuevas para la ciencia: Drymonia submarginalis (Gesneriaceae), Ocotea gomezii, Ocotea morae, Povedadaphne quadriporata (Lauraceae), Marlierea mesoamericana (Myrtaceae), Prosthechea ortizii (Orchidaceae, como Encyclia ortizii), Coccoloba porphyrostachys, Coccoloba liportizii (Polygonaceae), Rudgea monofructus (Rubiaceae) y Ticodendron incognitum (Ticodendraceae); ésta última, una familia nueva para la ciencia. 
Abu Ghraib, 2004: Doctrinal Confusion of American Military Police
Authors: House Shelby
Published: November 2015

The Abu Ghraib prison scandal in 2004 was one of the worst and most widely talked-about cases of prisoner abuse by American forces during any war. This scandal had lasting implications for the War in Iraq and America's War on Terror as a whole. This essay examines what failures in military doctrine led to such egregious abuses and how those failures have or have not been remedied.
Triglyceride Regulation of Lysosomal Cholesterol in THP-1 Macrophages
Authors: Dorrell Robert
Published: November 2015

The central question I investigated in my research this semester was how the cholesterol and triglyceride metabolic pathways interact in macrophages when cholesterol levels are high. What factors prevent or enhance macrophage ability to regulate cholesterol metabolism? We have preliminary evidence that excessive cholesterol accumulation in macrophages alters triglyceride metabolism in these cells. When cellular cholesterol levels are normal, the primary site of triglyceride hydrolysis is on the surface of the macrophage. There, lipases hydrolyze triglycerides within triglyceride-rich lipoproteins to glycerol and fatty acids. The fatty acids are carried across the cell membrane into the cytoplasm. In the cytoplasm, the fatty acids can be utilized to make triglycerides, phospholipids and cholesteryl esters. Cholesterol influences how the cell breaks down triglycerides. If cholesterol levels are high then triglyceride metabolism tends to occur more frequently in the lysosome. In contrast, when the cells have excess cholesterol, particularly within their lysosomes, the surface hydrolysis is suppressed and lipoproteins are taken up by endocytosis and delivered to lysosomes for hydrolysis. The effect of inhibiting the surface lipolysis was evaluated to determine the impact on intracellular cholesterol and triglyceride levels. The data indicates that the presence of triglyceride restores lysosomal metabolism of cholesterol.
Should extinction be forever
Authors: Saulsberry Ashley
Published: November 2015

Typically the extinction of a species is thought of as an ultimate end by conservation biologists. However, now with the advent of inter-species somatic cell nuclear transfer extinct species can be re-created using a tissue sample from the extinct species and oocytes from a related species. This technology has a long way to go before stable populations of previously extinct species can be created, but we must consider the ethics of re-creating extinct species and the potential consequences of de-extinction, whether positive or negative. Re-creating extinct species could potentially allow for justice for these wronged species and new cultural, research, and ecological value. However, some argue this process is too unnatural or hubristic, and it could also detract from conserving extant species and have negative effects on human societies and cultures or ecosystems. Re-creating extinct species may ultimately be an inevitable technological advancement, but we must consider all these issues to make sure de-extinction is pursued in such a way to have net positive effects.
Adam Smith's Impartial Spectator: His Reliance on Societal Values, Limits in Inspiring Altruism, and Application in Today's Context
Authors: Shin Jung Min
Published: November 2015

In his comprehensive overview of moral philosophy, The Theory of Moral Sentiments (1759), Adam Smith made a key contribution through the concept of the “impartial spectator”—an imagined third party who allows an individual to objectively judge the ethical status of his or her actions. Also called the “man within the breast,” the impartial spectator is a tool through which individuals divide themselves into the “judge” and “the judged” to examine their own conduct in an unbiased manner. While Smith conceptualizes this imaginary figure as an embodiment of universal morality, and hence not limited to the values of one’s immediate community, I argue that this is largely impossible due to the character’s society-reliant nature. The impartial spectator is inevitably a local figure, a judge who, while objective, adjudicates based on the context of one’s immediate social milieu. Furthermore, due to his dependence on community norms, the impartial spectator is unable to motivate individuals to care for those outside conventional society’s concerns, and is ultimately restricted in his capacity to inspire moral improvement. Interestingly, however, the “man within the breast’s” society-driven nature seem less problematic and debilitating to Smith’s overall self-evaluation method in the context of today’s globalized, equality-driven world. His reliance on community norms does not serve as a key hindrance factor for inspiring altruism today, which demonstrates that Smith’s introspective technique may be better-suit for application in the present than in the philosopher’s time.
The Flexner Report and the African-American Health Experience: Black Collective Memory and Identity as Shaped by Afro-cultural Trauma and Re-membering
Authors: Arrington Jasmine
Published: November 2015

The 1910 Flexner Report was a seemingly benevolent document intended to standardize medical education and increase the quality of physicians in the United States. Despite good intentions, it was a document with implications for African-Americans. The Flexner Report caused the closing of historically black medical schools, leaving two in the nation – Howard Medical School in the North and Meharry Medical College in the South. African-Americans were excluded from the institution of medicine, leaving blacks vulnerable to institutional abuses in health that facilitated distrust and disenfranchisement. This paper argues that despite the trauma experienced from violation and exclusion, Meharry Medical College serves as a chronotope that helps rebuild and symbolically re-member black collective identity and memory within and beyond medical education. The trauma includes present day black medical students and physicians not considered the equals of their white counterparts and black patients who suffered physical abuse and the infringement of self-determination. That created crises in collective African-American identity, sparking social pain. The Flexner Report is deeply implicated in structural inequality that has systematically disenfranchised African-Americans in medical education. Moving beyond structural inequalities, the Flexner Report is an unacknowledged source of trauma in the collective African-American health experience with both literal and figurative ramifications.
From the Light and into the Dark: the Transformation to the Early Middle Ages
Authors: Choudhary Arrush
Published: November 2015

From a historic perspective, the period of Roman rule and the following Middle Ages are polar opposites. For most, the city of Rome and the Western Roman Empire represent a time of advancement for the Mediterranean world while the Middle Ages are viewed as a regression of sorts for Europe. The reasons explaining the underlying cause of this transition from the Western Roman Empire to the Middle Ages are numerous but this paper will specifically focus on the practices started by the Romans themselves and how they contributed to the rise of the Early Middle Ages on the Italian Peninsula. More specifically, economic turmoil and urbanization following the 3rd century crisis in the city of Rome laid the groundwork for social, legislative, and political changes that thread the path to the fundamental characteristics of the Middle Ages. Changing views of the city and the countryside, the construction of latifundia and villas, and the passing of legislation that restricted the rights of laborers, in addition to other transformations in late Rome, all contributed to the decentralized governance, rural life, and serfdom that are characteristic of the Middle Ages. Ultimately, the goal of this paper is to illustrate that despite the major differences that exist between the Roman period and the Middle Ages, the practices of the late Western Roman Empire were often directly carried over into the Middle Ages and, as a result, for one to truly understand the origins of the Middle Ages, it is essential to comprehend the traditions started by the late Romans.
Murphy vs. Domino in Florida's 18th Congressional District: A Case Study in Localizing Congressional Elections to Survive a Political Wave
Authors: Greenberg Jeffrey Alexander
Published: November 2015

The 2014 Midterm Elections saw Republicans sweep the House of Representatives and retake the United States Senate. This paper examines how select Democrats survived this wave election by analyzing the case of Florida's 18th Congressional District, Patrick Murphy (D-Incumbent) vs Carl Domino (R). The analysis uses descriptive statistics of the district as well as precinct and county election results from 2012 and 2014 in order to show change in the political success of the Democrat Murphy. It then uses advertisement data and campaign finances, as well as personal interviews to find a reason for the change. The author concludes that a focus on the localization of district issues created a variety of effects that both aided Murphy and harmed the challenger Domino in 2014. This chain reaction, including the interaction between local and national politics and parties, would come to define the success of Democrats in the 2014 Midterms.
The Route to Crisis: Cities, Trade, and Epidemics of the Roman Empire
Authors: Hanna Eriny
Published: November 2015

The goal of this paper is to provide a universal model that outlines the origins of disease contraction and transmission in the ancient Mediterranean world. While numerous scholars have written on the subject of epidemics and their effects on the Roman Empire, very limited studies focus on the general causes of epidemics throughout the Roman era. I propose that Roman culture, urbanism, and the interdependence between cities and provinces led to the entry and transmission of communicable diseases, contributing to conditions that ultimately caused the fall of the empire. I first discuss and describe the causal factors of epidemics. I start by presenting Roman ideologies as this will aid in the understanding of city structure. After a description of a typical city layout, I present the conditions which encouraged the spread of disease within cities. Cities and provinces were not in isolation, but rather part of a greater economic network. I, therefore, also describe the nature of trade routes and how trade impacted the global spread of pathogens. I conclude by applying the proposed theories to two plagues—the Antonine Plague and Justinianic Plague—from different, yet comparable, time periods. I also gauge the effects of disease on Roman economy, demography, and society by using these case studies.
The Histone Methyltransferase Enzyme Enhancer of Zeste Homolog 2 Protects against Podocyte Oxidative Stress and Renal Injury in Diabetes
Authors: Siddiqi Ferhan S. , Majumder Syamantak , Thai Kerri , Abdalla Moustafa , Hu Pingzhao , Advani Suzanne L. , White Kathryn E. , Bowskill Bridgit B. , Guarna Giuliana , dos Santos Claudia C. , Connelly Kim A. , Advani Andrew
Published: November 2015

Epigenetic regulation of oxidative stress is emerging as a critical mediator of diabetic nephropathy. In diabetes, oxidative damage occurs when there is an imbalance between reactive oxygen species generation and enzymatic antioxidant repair. Here, we investigated the function of the histone methyltransferase enzyme enhancer of zeste homolog 2 (EZH2) in attenuating oxidative injury in podocytes, focusing on its regulation of the endogenous antioxidant inhibitor thioredoxin interacting protein (TxnIP). Pharmacologic or genetic depletion of EZH2 augmented TxnIP expression and oxidative stress in podocytes cultured under high-glucose conditions. Conversely, EZH2 upregulation through inhibition of its regulatory microRNA, microRNA-101, downregulated TxnIP and attenuated oxidative stress. In diabetic rats, depletion of EZH2 decreased histone 3 lysine 27 trimethylation (H3K27me3), increased glomerular TxnIP expression, induced podocyte injury, and augmented oxidative stress and proteinuria. Chromatin immunoprecipitation sequencing revealed H3K27me3 enrichment at the promoter of the transcription factor Pax6, which was upregulated on EZH2 depletion and bound to the TxnIP promoter, controlling expression of its gene product. In high glucose–exposed podocytes and the kidneys of diabetic rats, the lower EZH2 expression detected coincided with upregulation of Pax6 and TxnIP. Finally, in a gene expression array, TxnIP was among seven of 30,854 genes upregulated by high glucose, EZH2 depletion, and the combination thereof. Thus, EZH2 represses the transcription factor Pax6, which controls expression of the antioxidant inhibitor TxnIP, and in diabetes, downregulation of EZH2 promotes oxidative stress. These findings expand the extent to which epigenetic processes affect the diabetic kidney to include antioxidant repair.