4,991 research outputs found
Storm-related suspended particulate matter in Little Westham Creek
Properties of a watershed regulate the amount of suspended particulate matter (SPM) in a stream. The present study examined relationships between storm-related SPM and impervious area and tree cover in the suburban watershed of Little Westham Creek, Richmond, Virginia during Summer and early Fall, 1999. SPM concentration, SPM discharge, and turbidity due to clay, silt and sand, and the areas of impervious surface and tree stand cover in the watershed were measured at three sites. SPM concentration, SPM discharge, and turbidity due to clay were greater upstream than downstream. The percentages of watershed area covered by impervious surfaces and tree stands also were greater upstream than downstream. SPM was most likely associated with impervious area, not tree cover
An innovative approach to improving father-child relationships for fathers who are noncompliant with child support payments: a mixed methods evaluation
Mixed methods were used to evaluate the effectiveness of the Fathers Offering Children Unfailing Support (FOCUS) program. FOCUS is a diversion program which is designed to offer an alternative to incarceration for fathers who are noncompliant with child support payments. Quantitative data were collected through a pretest/posttest design (n = 55) and qualitative data were collected through telephone interviews with FOCUS instructors (n = 2) and community key stakeholders (n = 5) and focus groups with FOCUS participants (n = 76). FOCUS appears to be benefiting children by increasing their fathersâ emotional support, strengthening co-parenting relationships, and promoting their fathersâ parenting skills
Adios to Paper JournalsâRemoved and RecycledâOne Mile Long and 75 Tons
This presentation uses Appalachian State Universityâs experiences as a stimulus for discussing how we have, and others may, successfully remove in a single swoop several thousand linear feet of little used bound periodicals. This effort opens library areas for new services and spaces. The program will be a resource and guide to others interested in largeâscale deaccessioning projects and includes three deaccessioning projects using online back files from 1) JSTOR; 2) ScienceDirect, Wiley, and Sage; and 3) journals outside of these packages
Antagonism of GABA-B but not GABA-A receptors in the VTA prevents stress- and intra-VTA CRF-induced reinstatement of extinguished cocaine seeking in rats
Stress-induced reinstatement of cocaine seeking requires corticotropin releasing factor (CRF) actions in the ventral tegmental area (VTA). However the mechanisms through which CRF regulates VTA function to promote cocaine use are not fully understood. Here we examined the role of GABAergic neurotransmission in the VTA mediated by GABA-A or GABA-B receptors in the reinstatement of extinguished cocaine seeking by a stressor, uncontrollable intermittent footshock, or bilateral intra-VTA administration of CRF. Rats underwent repeated daily cocaine self-administration (1.0 mg/kg/ing; 14 Ă 6 h/day) and extinction and were tested for reinstatement in response to footshock (0.5 mA, 0.5â duration, average every 40 s; range 10â70 s) or intra-VTA CRF delivery (500 ng/side) following intra-VTA pretreatment with the GABA-A antagonist, bicuculline, the GABA-B antagonist, 2-hydroxysaclofen or vehicle. Intra-VTA bicuculline (1, 10 or 20 ng/side) failed to block footshock- or CRF-induced cocaine seeking at either dose tested. By contrast, 2-hydroxysaclofen (0.2 or 2 ÎŒg/side) prevented reinstatement by both footshock and intra-VTA CRF at a concentration that failed to attenuate food-reinforced lever pressing (45 mg sucrose-sweetened pellets; FR4 schedule) in a separate group of rats. These data suggest that GABA-B receptor-dependent CRF actions in the VTA mediate stress-induced cocaine seeking and that GABA-B receptor antagonists may have utility for the management of stress-induced relapse in cocaine addicts
Augmented Cocaine Seeking in Response to Stress or CRF Delivered into the Ventral Tegmental Area Following Long-Access Self-Administration Is Mediated by CRF Receptor Type 1 But Not CRF Receptor Type 2
Stressful events are determinants of relapse in recovering cocaine addicts. Excessive cocaine use may increase susceptibility to stressor-induced relapse through alterations in brain corticotropin-releasing factor (CRF) regulation of neurocircuitry involved in drug seeking. We previously reported that the reinstatement of cocaine seeking by a stressor (footshock) is CRF dependent and is augmented in rats that self-administered cocaine under long-access (LgA; 6 h daily) conditions for 14 d when compared with rats provided shorter daily cocaine access [short access (ShA) rats; 2 h daily]. Further, we have demonstrated that reinstatement in response to intracerebroventricular CRF administration is heightened in LgA rats. This study examined the role of altered ventral tegmental area (VTA) responsiveness to CRF in intake-dependent increases in CRF- and stress-induced cocaine seeking. Bilateral intra-VTA administration of CRF (250 or 500 ng/side) produced reinstatement in LgA but not ShA rats. In LgA rats, intra-VTA CRF-induced reinstatement was blocked by administration of the CRF-receptor type 1 (CRF-R1) antagonist antalarmin (500 ng/side) or CP-376395 (500 ng/side), but not the CRF-R2 antagonist astressin-2B (500 ng or 1 ÎŒg/side) or antisauvagine-30(ASV-30; 500 ng/side) into the VTA. Likewise, intra-VTA antalarmin, but not astressin-2B, blocked footshock-induced reinstatement in LgA rats. By contrast, neither intra-VTA antalarmin nor CP-376395 altered food-reinforced lever pressing. Intra-VTA injection of the CRF-R1-selective agonist cortagine (100 ng/side) but not the CRF-R2-selective agonist rat urocortin II (rUCN II; 250 ng/side) produced reinstatement. These findings reveal that excessive cocaine use increases susceptibility to stressor-induced relapse in part by augmenting CRF-R1-dependent regulation of addiction-related neurocircuitry in the VTA
The Hidden Curriculum of a Teacher Induction Program: Ontario Teacher Educatorsâ Perspectives
This article investigates the hidden curriculum of Ontarioâs New Teacher Induction Program (NTIP). The study involved interviews with 47 teacher educators from eight faculties of education. Responses revealed concerns about (a) who chooses the menâ tors, (b) the probationary status of new teachers, and (c) the evaluation of new teachâ ersâ competence. In the opinion of some teacher educators, the structure of NTIP may discourage new teachers from critiquing the system that employs them thus decreasâ ing the likelihood of their taking a critical democratic stance in their teaching. These findings have implications for any induction or mentorship program for new teachâ ers. Key Words: teacher education, mentorship, social justice, critical democratic, Ontario New Teacher Induction ProgramCet article porte sur les objectifs cachĂ©s du Programme dÊčinsertion professionnelle du nouveau personnel enseignant (PIPNPE) de lâOntario. Pour cette recherche, les auâ teurs ont interviewĂ© 47 professeurs de pĂ©dagogie dans huit facultĂ©s dâĂ©ducation. Ces entrevues rĂ©vĂšlent des inquiĂ©tudes au sujet (a) du mode de sĂ©lection des mentors, (b) du statut probatoire du nouveau personnel enseignant, (c) de lâĂ©valuation des compĂ©â tences du nouveau personnel enseignant. Selon certains des rĂ©pondants, la structure du PIPNPE peut dissuader certains nouveaux enseignants de critiquer le systĂšme qui les emploie, ce qui diminue les chances quâils prennent une orientation dĂ©mocratique critique dans leur enseignement. Ces observations ont des implications pour tout programme dâinsertion professionnelle ou de mentorat sâadressant au nouveau perâ sonnel enseignant. Mots clĂ©s : formation Ă lâenseignement, mentorat, justice sociale, critique, dĂ©mocratiâ que, Programme dÊčinsertion professionnelle du nouveau personnel enseignant de lâOntario.
Spectroscopy and dynamics of the hydrated electron at the water/air interface
The hydrated electron, eâ(aq), has attracted much attention as a central species in radiation chemistry. However, much less is known about eâ(aq) at the water/air surface, despite its fundamental role in electron transfer processes at interfaces. Using time-resolved electronic sum-frequency generation spectroscopy, the electronic spectrum of eâ(aq) at the water/air interface and its dynamics are measured here, following photo-oxidation of the phenoxide anion. The spectral maximum agrees with that for bulk eâ(aq) and shows that the orbital density resides predominantly within the aqueous phase, in agreement with supporting calculations. In contrast, the chemistry of the interfacial hydrated electron differs from that in bulk water, with eâ(aq) diffusing into the bulk and leaving the phenoxyl radical at the surface. Our work resolves long-standing questions about eâ(aq) at the water/air interface and highlights its potential role in chemistry at the ubiquitous aqueous interface
Direct Kerr-frequency-comb atomic spectroscopy
Microresonator-based soliton frequency combs - microcombs - have recently
emerged to offer low-noise, photonic-chip sources for optical measurements.
Owing to nonlinear-optical physics, microcombs can be built with various
materials and tuned or stabilized with a consistent framework. Some
applications require phase stabilization, including optical-frequency synthesis
and measurements, optical-frequency division, and optical clocks. Partially
stabilized microcombs can also benefit applications, such as oscillators,
ranging, dual-comb spectroscopy, wavelength calibration, and optical
communications. Broad optical bandwidth, brightness, coherence, and frequency
stability have made frequency-comb sources important for studying comb-matter
interactions with atoms and molecules. Here, we explore direct microcomb atomic
spectroscopy, utilizing a cascaded, two-photon 1529-nm atomic transition of
rubidium. Both the microcomb and the atomic vapor are implemented with planar
fabrication techniques to support integration. By fine and simultaneous control
of the repetition rate and carrier-envelope-offset frequency of the soliton
microcomb, we obtain direct sub-Doppler and hyperfine spectroscopy of the
manifold. Moreover, the entire set of microcomb modes are
stabilized to this atomic transition, yielding absolute optical-frequency
fluctuations of the microcomb at the kilohertz-level over a few seconds and < 1
MHz day-to-day accuracy. Our work demonstrates atomic spectroscopy with
microcombs and provides a rubidium-stabilized microcomb laser source, operating
across the 1550 nm band for sensing, dimensional metrology, and communication.Comment: 5 pages, 3 figure
Suspended sediment export in five intensive agricultural river catchments with contrasting land use and soil drainage characteristics
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