628 results match your criteria: "Bowdoin College.[Affiliation]"

Critical Phenomena in the Gravitational Collapse of Electromagnetic Waves.

Phys Rev Lett

October 2019

CENTRA, Departamento de Física, Instituto Superior Técnico IST, Universidade de Lisboa UL, Avenida Rovisco Pais 1, 1049 Lisboa, Portugal.

We numerically investigate the threshold of black-hole formation in the gravitational collapse of electromagnetic waves in axisymmetry. We find approximate power-law scaling ρ_{max}∼(η_{*}-η)^{-2γ} of the maximum density in the time evolution of near-subcritical data with γ≃0.145, where η is the amplitude of the initial data.

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This paper presents the first study to examine the psychometric qualities of a Turkish translation and adaptation of the Early Adolescent Temperament Questionnaire - Revised (EATQ-R). Participants included 1,109 Turkish adolescents (48.7% females) aged 11 to 15 years.

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, the most common fungal pathogen, is a diploid with a genome that is rich in repeats and has high levels of heterozygosity. To study the role of different recombination pathways on direct-repeat recombination, we replaced either allele of the gene (Chr6) with the -blaster cassette (), measured rates of loss as resistance to 5-fluoroorotic acid (5FOA) and used CHEF Southern hybridization and SNP-RFLP analysis to identify recombination mechanisms and their frequency in wildtype and recombination mutants. FOA rates varied little across different strain backgrounds.

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Homolog Pairing at the Push of a Button.

Dev Cell

November 2019

Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address:

Homologous chromosomes pair in somatic cells in Drosophila, but how this occurs is poorly understood. In this issue of Developmental Cell, Viets et al. (2019) show that proteins and chromatin structure mediate pairing and argue against a DNA sequence-based mechanism.

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This paper highlights the challenge of predicting the excited state proton transfer (ESPT) reactions of small organic compounds with multiple proton transfer sites. Aminonaphthols, naphthalene compounds with both hydroxyl and amino substituents, can be viewed as a combination of two monoprotic photoacids, naphthol and naphthylammonium. Here, the ESPT reactions of 3-ammonium-2-naphthol (3N2OH) and 1-ammonium-2-naphthol (1N2OH) were studied in water and methanol using a combination of steady-state and time-correlated single-photon counting emission spectroscopy.

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ADHD and ODD Symptoms in Toddlers: Common and Specific Associations with Temperament Dimensions.

Child Psychiatry Hum Dev

April 2020

Department of Developmental Psychology and Education, Faculty of Psychology, University of Murcia, Campus de Espinardo, 30100, Murcia, Spain.

The aim of this work was to study the relationship between temperament and signs of psychopathology in typically developing toddlers. More specifically, Attentional Deficit Hyperactivity Disorder (ADHD) and Oppositional Defiant Disorder (ODD) symptoms were analyzed in connection with fine-grained temperament dimensions. The sample was composed of 65 toddlers aged between 18 and 35 months.

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Guidance cues act during development to guide growth cones to their proper targets in both the central and peripheral nervous systems. Experiments in many species indicate that guidance molecules also play important roles after development, though less is understood about their functions in the adult. The Semaphorin family of guidance cues, signaling through Plexin receptors, influences the development of both axons and dendrites in invertebrates.

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Position Effects Influence Transvection in .

Genetics

December 2019

Biology Department, Bowdoin College, Brunswick, Maine 04011

Transvection is an epigenetic phenomenon wherein regulatory elements communicate between different chromosomes in , and is thereby dependent upon the three-dimensional organization of the genome. Transvection is best understood in , where homologous chromosomes are closely paired in most somatic nuclei, although similar phenomena have been observed in other species. Previous data have supported that the genome is generally permissive to enhancer action in , a form of transvection where an enhancer on one homolog activates gene expression from a promoter on a paired homolog.

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Chlorophyll fluorometry is one of the most commonly implemented approaches for estimating phytoplankton biomass in situ, despite documented sources of natural variability and instrumental uncertainty in the relationship between in vivo fluorescence and chlorophyll concentration. A number of strategies are employed to minimize errors and quantify natural variability in this relationship in the open ocean. However, the assumptions underlying these approaches are unsupported in coastal waters due to the short temporal and small spatial scales of variability, as well as the optical complexity.

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Mindfulness meditation has been shown to improve episodic memory and increase theta oscillations which are known to play a role in episodic memory retrieval. The present study examined the effect of mindfulness meditation on episodic memory retrieval and theta oscillations. Using a longitudinal design, subjects in the mindfulness meditation experimental group who underwent 4 weeks of mindfulness meditation training and practice were compared to a waitlist control group.

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Injecting Gryllus bimaculatus Eggs.

J Vis Exp

August 2019

Department of Organismic and Evolutionary Biology and Department of Molecular and Cellular Biology, Harvard University.

Altering gene function in a developing organism is central to different kinds of experiments. While tremendously powerful genetic tools have been developed in traditional model systems, it is difficult to manipulate genes or messenger RNA (mRNA) in most other organisms. At the same time, evolutionary and comparative approaches rely on an exploration of gene function in many different species, necessitating the development and adaptation of techniques for manipulating expression outside currently genetically tractable species.

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Sugar-Modified Analogs of Auranofin Are Potent Inhibitors of the Gastric Pathogen .

ACS Infect Dis

October 2019

Department of Chemistry & Biochemistry , Bowdoin College , 6600 College Station, Brunswick , Maine 04011 , United States.

() infection poses a worldwide public health crisis, as chronic infection is rampant and can lead to gastric ulcers, gastritis, and gastric cancer. Unfortunately, frontline therapies cause harmful side effects and are often ineffective due to antibiotic resistance. The FDA-approved drug auranofin is a gold complex with a Au(I) core coordinated with triethylphosphine and peracetylated thioglucose as the ligands.

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Background: Previous studies of relations between parenting self-concepts, parental adjustment and child temperament have been ambiguous regarding the direction of influence; and have rarely followed families from pregnancy through the first year of life. The current study examines change and stability in maternal depressive symptoms, parenting competences and child temperament through the perinatal period until nine months postpartum.

Methods: Czech mothers (N = 282) participated at three time points: the third trimester of pregnancy (Time 1), six weeks (Time 2) and nine months postpartum (Time 3).

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Marine intertidal systems have long served as focal environments for ecological research, yet these environments are changing due to the entry of human-produced carbon dioxide into seawater, which causes 'ocean acidification' (OA). One component of OA is a decline in seawater pH, an alteration known to disrupt organism behaviors underlying predator-prey interactions. To date, however, studies examining OA's effects on feeding relationships consider predominantly simple direct interactions between consumers and their food sources.

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Diagnosis of the presence of tumors and subsequent prognosis based on tumor microenvironment becomes more clinically practical because tumor-adjacent tissues are easy to collect and they are more genetically homogeneous. The purpose of this study was to identify new prognostic markers in prostate stroma that are near the tumor. We have demonstrated the prognostic features of FGFR1, FRS2, S6K1, LDHB, MYPT1, and P-LDHA in prostate tumors using tissue microarrays (TMAs) which consist of 241 patient samples from Massachusetts General Hospital (MGH).

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Medical reasoning and doctor-patient communication.

J Eval Clin Pract

December 2019

Department of Philosophy, Bowdoin College, Brunswick, Maine.

Nineteenth-century American philosopher Charles Sanders Peirce offered a picture of the scientific method that can be fruitfully applied to the practice of medical diagnosis. Physicians can use this framework to become more self-consciously aware of what they are doing when they diagnose medical conditions, and they can also learn more about the potential pitfalls of communication between physicians and their patients.

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Mitochondrial genotype influences the response to cold stress in the European green crab, .

J Exp Biol

September 2019

Department of Biology & Schiller Coastal Studies Center, Bowdoin College, Brunswick, ME 04011, USA

Hybrid zones provide natural experiments in recombination within and between genomes that may have strong effects on organismal fitness. On the East Coast of North America, two distinct lineages of the European green crab () have been introduced in the last two centuries. These two lineages with putatively different adaptive properties have hybridized along the coast of the eastern Gulf of Maine, producing new nuclear and mitochondrial combinations that show clinal variation correlated with water temperature.

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Knowledge of the genetic architecture of importantly agronomical traits can speed up genetic improvement in cultivated rice (Oryza sativa L.). Many recent investigations have leveraged genome-wide association studies (GWAS) to identify single nucleotide polymorphisms (SNPs), associated with agronomic traits in various rice populations.

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SIFamide peptides modulate cardiac activity differently in two species of Cancer crab.

Gen Comp Endocrinol

October 2019

Békésy Laboratory of Neurobiology, Pacific Biosciences Research Center, School of Ocean and Earth Science and Technology, University of Hawaii at Manoa, 1993 East-West Road, Honolulu, HI 96822, USA.

The SIFamides are a broadly conserved arthropod peptide family characterized by the C-terminal motif -SIFamide. In decapod crustaceans, two isoforms of SIFamide are known, GYRKPPFNGSIFamide (Gly-SIFamide), which is nearly ubiquitously conserved in the order, and VYRKPPFNGSIFamide (Val-SIFamide), known only from members of the astacidean genus Homarus. While much work has focused on the identification of SIFamide isoforms in decapods, there are few direct demonstrations of physiological function for members of the peptide family in this taxon.

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The first formed tooth serves as a signalling centre to induce the formation of the dental row in zebrafish.

Proc Biol Sci

June 2019

2 Institut de Génomique Fonctionnelle de Lyon, UMR 5242 du CNRS, Université de Lyon, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon , 46 Allée d'Italie, 69364 Lyon Cedex 07 , France.

The diversity of teeth patterns in actinopterygians is impressive with tooth rows in many locations in the oral and pharyngeal regions. The first-formed tooth has been hypothesized to serve as an initiator controlling the formation of the subsequent teeth. In zebrafish, the existence of the first tooth (named 4 V) is puzzling as its replacement is induced before the opening of the mouth.

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Speed of person perception affects immediate and ongoing aesthetic evaluation.

Acta Psychol (Amst)

June 2019

Department of Art History and Archaeology & Italian Academy for Advanced Studies, Columbia University, USA.

Recent studies have shed light on how aesthetic judgments are formed following presentations lasting less than a second. Meanwhile, dedicated neural mechanisms are understood to enable the rapid detection of human faces, bodies, and actions. On the basis of cognitive studies of: (i) the speed and acuity of person perception, and (ii) preferential attention given to human imagery (e.

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Genome rearrangements resulting in copy number variation (CNV) and loss of heterozygosity (LOH) are frequently observed during the somatic evolution of cancer and promote rapid adaptation of fungi to novel environments. In the human fungal pathogen , CNV and LOH confer increased virulence and antifungal drug resistance, yet the mechanisms driving these rearrangements are not completely understood. Here, we unveil an extensive array of long repeat sequences (65-6499 bp) that are associated with CNV, LOH, and chromosomal inversions.

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Alarming Trends in Mortality from Firearms Among United States Schoolchildren.

Am J Med

August 2019

Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton; Baylor College of Medicine, Houston, Texas. Electronic address:

Background: Mortality from firearms among US schoolchildren is an increasingly major clinical and public health crisis. We explored temporal trends in mortality from firearms among US schoolchildren from 1999 to 2017 by age and race.

Methods: We used the Multiple Cause of Death Files of the United States National Center for Health Statistics; PubMed searches, and joinpoint regressions for trend analyses and calculated mortality rates and 95% confidence limits.

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The principles underlying the art of origami paper folding can be applied to design sophisticated metamaterials with unique mechanical properties. By exploiting the flat crease patterns that determine the dynamic folding and unfolding motion of origami, we are able to design an origami-based metamaterial that can form rarefaction solitary waves. Our analytical, numerical, and experimental results demonstrate that this rarefaction solitary wave overtakes initial compressive strain waves, thereby causing the latter part of the origami structure to feel tension first instead of compression under impact.

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Northern hemisphere evergreen forests assimilate a significant fraction of global atmospheric CO but monitoring large-scale changes in gross primary production (GPP) in these systems is challenging. Recent advances in remote sensing allow the detection of solar-induced chlorophyll fluorescence (SIF) emission from vegetation, which has been empirically linked to GPP at large spatial scales. This is particularly important in evergreen forests, where traditional remote-sensing techniques and terrestrial biosphere models fail to reproduce the seasonality of GPP.

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