Quartz tuning-fork oscillations in He II and drag coefficient

NASA Astrophysics Data System (ADS)

Gritsenko, I. A.; Zadorozhko, A. A.; Neoneta, A. S.; Chagovets, V. K.; Sheshin, G. A.

2011-07-01

The temperature dependencies of drag coefficient for quartz tuning forks of various geometric dimensions, immersed in the He II, were determined experimentally in the temperature range 0.1-3 K. It is identified, that these dependencies are similar, but the values of drag coefficient are different for tuning forks with different geometric dimensions. It is shown, that the obtained specific drag coefficient depends only on the temperature and frequency of vibrations, when the value of drag coefficient is normalized to the surface area of moving tuning-fork prong. The temperature dependencies of normalized drag coefficient for the tuning forks of various dimensions, wire, and microsphere, oscillating in the Не II, are compared. It is shown, that in the ballistic regime of scattering of quasiparticles, these dependencies are identical and have a slope proportional to T4, which is determined by the density of thermal excitations. In the hydrodynamic regime at T > 0.5 K, the behavior of the temperature dependence of specific drag coefficient is affected by the size and frequency of vibrating body. The empirical relation, which allows to describe the behavior of specific drag coefficient for vibrating tuning forks, microsphere, and wire everywhere over the temperature region and at various frequencies, is proposed.

Rinne test: does the tuning fork position affect the sound amplitude at the ear?

PubMed

Butskiy, Oleksandr; Ng, Denny; Hodgson, Murray; Nunez, Desmond A

2016-03-24

Guidelines and text-book descriptions of the Rinne test advise orienting the tuning fork tines in parallel with the longitudinal axis of the external auditory canal (EAC), presumably to maximise the amplitude of the air conducted sound signal at the ear. Whether the orientation of the tuning fork tines affects the amplitude of the sound signal at the ear in clinical practice has not been previously reported. The present study had two goals: determine if (1) there is clinician variability in tuning fork placement when presenting the air-conduction stimulus during the Rinne test; (2) the orientation of the tuning fork tines, parallel versus perpendicular to the EAC, affects the sound amplitude at the ear. To assess the variability in performing the Rinne test, the Canadian Society of Otolaryngology - Head and Neck Surgery members were surveyed. The amplitudes of the sound delivered to the tympanic membrane with the activated tuning fork tines held in parallel, and perpendicular to, the longitudinal axis of the EAC were measured using a Knowles Electronics Mannequin for Acoustic Research (KEMAR) with the microphone of a sound level meter inserted in the pinna insert. 47.4 and 44.8% of 116 survey responders reported placing the fork parallel and perpendicular to the EAC respectively. The sound intensity (sound-pressure level) recorded at the tympanic membrane with the 512 Hz tuning fork tines in parallel with as opposed to perpendicular to the EAC was louder by 2.5 dB (95% CI: 1.35, 3.65 dB; p < 0.0001) for the fundamental frequency (512 Hz), and by 4.94 dB (95% CI: 3.10, 6.78 dB; p < 0.0001) and 3.70 dB (95% CI: 1.62, 5.78 dB; p = .001) for the two harmonic (non-fundamental) frequencies (1 and 3.15 kHz), respectively. The 256 Hz tuning fork in parallel with the EAC as opposed to perpendicular to was louder by 0.83 dB (95% CI: -0.26, 1.93 dB; p = 0.14) for the fundamental frequency (256 Hz), and by 4.28 dB (95% CI: 2.65, 5.90 dB; p < 0.001) and 1.93 dB (95% CI: 0.26, 3.61 dB; p = .02) for the two harmonic frequencies (500 and 4 kHz) respectively. Clinicians vary in their orientation of the tuning fork tines in relation to the EAC when performing the Rinne test. Placement of the tuning fork tines in parallel as opposed to perpendicular to the EAC results in a higher sound amplitude at the level of the tympanic membrane.

Photolithography and Selective Etching of an Array of Quartz Tuning Fork Resonators with Improved Impact Resistance Characteristics

NASA Astrophysics Data System (ADS)

Lee, Sungkyu

2001-08-01

Quartz tuning fork blanks with improved impact-resistant characteristics for use in Qualcomm mobile station modem (MSM)-3000 central processing unit (CPU) chips for code division multiple access (CDMA), personal communication system (PCS), and global system for mobile communication (GSM) systems were designed using finite element method (FEM) analysis and suitable processing conditions were determined for the reproducible precision etching of a Z-cut quartz wafer into an array of tuning forks. Negative photoresist photolithography for the additive process was used in preference to positive photoresist photolithography for the subtractive process to etch the array of quartz tuning forks. The tuning fork pattern was transferred via a conventional photolithographical chromium/quartz glass template using a standard single-sided aligner and subsequent negative photoresist development. A tightly adhering and pinhole-free 600/2000 Å chromium/gold mask was coated over the developed photoresist pattern which was subsequently stripped in acetone. This procedure was repeated on the back surface of the wafer. With the protective metallization area of the tuning fork geometry thus formed, etching through the quartz wafer was performed at 80°C in a ± 1.5°C controlled bath containing a concentrated solution of ammonium bifluoride to remove the unwanted areas of the quartz wafer. The quality of the quartz wafer surface finish after quartz etching depended primarily on the surface finish of the quartz wafer prior to etching and the quality of quartz crystals used. Selective etching of a 100 μm quartz wafer could be achieved within 90 min at 80°C. A selective etching procedure with reproducible precision has thus been established and enables the photolithographic mass production of miniature tuning fork resonators.

ANSYS simulation of the capacitance coupling of quartz tuning fork gyroscope

NASA Astrophysics Data System (ADS)

Zhang, Qing; Feng, Lihui; Zhao, Ke; Cui, Fang; Sun, Yu-nan

2013-12-01

Coupling error is one of the main error sources of the quartz tuning fork gyroscope. The mechanism of capacitance coupling error is analyzed in this article. Finite Element Method (FEM) is used to simulate the structure of the quartz tuning fork by ANSYS software. The voltage output induced by the capacitance coupling is simulated with the harmonic analysis and characteristics of electrical and mechanical parameters influenced by the capacitance coupling between drive electrodes and sense electrodes are discussed with the transient analysis.

Spring constant of a tuning-fork sensor for dynamic force microscopy

PubMed Central

Lange, Manfred; Schmuck, Merlin; Schmidt, Nico; Möller, Rolf

2012-01-01

Summary We present an overview of experimental and numerical methods to determine the spring constant of a quartz tuning fork in qPlus configuration. The simple calculation for a rectangular cantilever is compared to the values obtained by the analysis of the thermal excitation and by the direct mechanical measurement of the force versus displacement. To elucidate the difference, numerical simulations were performed taking account of the real geometry including the glue that is used to mount the tuning fork. PMID:23365793

[History of the tuning fork. III: On the way to quantitative pure-tone measurement. Pictures from the history of otorhinolaryngology, represented by instruments from the collection of the Ingolstadt German Medical History Museum].

PubMed

Feldmann, H

1997-07-01

Weber's and Rinne's tuning-fork tests were for a long time considered unreliable, as they often seemed to yield inconsistent results. The sources of error were manifold and lay in the fields of physics, physiology, pathophysiology, and psychology. When the problems came to be understood, more sophisticated instruments and techniques were developed. The prongs of the tuning fork were fitted with clamps to deaden overtones when it was put into vibration (Politzer 1870). By shifting the clamps along the prongs the tone of the tuning fork could be varied in a range up to one octave (Könlg 1878). A knob of hom or metal was fixed to the end of the shaft to ensure a good coupling to the skull when testing bone conduction (Lucae 1886). A small hammer fixed to the shaft and driven by a spring would activate the tuning fork with reproducible strength (Lucae 1899). A wedge-shaped figure drawn on the lateral surface of the clamps would allow one to optically control the amplitude of vibration (Gradenigo 1899). The time during which a patient hears the tuning fork after it has been struck as compared to that of a normal hearing subject was measured as parameter of hearing acutiy (v. Conta 1864). A number of tuning forks at intervals of one octave each were assembled in sets to cover the whole frequency range of hearing. The most sophisticated example of these sets was the Bezold-Edelmann continuous tone series (1894). It comprised ten tuning forks with sliding clamps, two pipes of the organ type, and a Galton whistle. With this instrumentation it was possible to test the whole range of hearing. The results of testing the hearing via air conduction and bone conduction measured in duration and calculated as percentage of normal hearing were presented in charts (Hartmann 1885, Gradenigo 1893) which can be considered precursors of modern audiograms. The evolution of these instruments and methods is described in detail and illustrated by exhibits from the museum.

Little Known Facts about the Common Tuning Fork.

ERIC Educational Resources Information Center

Ong, P. P.

2002-01-01

Explains the physical principles of the tuning fork which has a common use in teaching laboratories. Includes information on its vibration, frequency of vibration, elasticity, and reasons for having two prongs. (YDS)

Development of a quartz tuning-fork-based force sensor for measurements in the tens of nanoNewton force range during nanomanipulation experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oiko, V. T. A., E-mail: oiko@ifi.unicamp.br; Rodrigues, V.; Ugarte, D.

2014-03-15

Understanding the mechanical properties of nanoscale systems requires new experimental and theoretical tools. In particular, force sensors compatible with nanomechanical testing experiments and with sensitivity in the nN range are required. Here, we report the development and testing of a tuning-fork-based force sensor for in situ nanomanipulation experiments inside a scanning electron microscope. The sensor uses a very simple design for the electronics and it allows the direct and quantitative force measurement in the 1–100 nN force range. The sensor response is initially calibrated against a nN range force standard, as, for example, a calibrated Atomic Force Microscopy cantilever; subsequently,more » applied force values can be directly derived using only the electric signals generated by the tuning fork. Using a homemade nanomanipulator, the quantitative force sensor has been used to analyze the mechanical deformation of multi-walled carbon nanotube bundles, where we analyzed forces in the 5–40 nN range, measured with an error bar of a few nN.« less

A High Sensitivity Preamplifier for Quartz Tuning Forks in QEPAS (Quartz Enhanced PhotoAcoustic Spectroscopy) Applications

PubMed Central

Starecki, Tomasz

2017-01-01

All the preamplifiers dedicated for Quartz Enhanced PhotoAcoustic Spectroscopy (QEPAS) applications that have so far been reported in the literature have been based on operational amplifiers working in transimpedance configurations. Taking into consideration that QEPAS sensors are based on quartz tuning forks, and that quartz has a relatively high voltage constant and relatively low charge constant, it seems that a transimpedance amplifier is not an optimal solution. This paper describes the design of a quartz QEPAS sensor preamplifier, implemented with voltage amplifier configuration. Discussion of an electrical model of the circuit and preliminary measurements are presented. Both theoretical analysis and experiments show that use of the voltage configuration allows for a substantial increase of the output signal in comparison to the transimpedance circuit with the same tuning fork working in identical conditions. Assuming that the sensitivity of the QEPAS technique depends directly on the properties of the preamplifier, use of the voltage amplifier configuration should result in an increase of QEPAS sensitivity by one to two orders of magnitude. PMID:29099765

A High Sensitivity Preamplifier for Quartz Tuning Forks in QEPAS (Quartz Enhanced PhotoAcoustic Spectroscopy) Applications.

PubMed

Starecki, Tomasz; Wieczorek, Piotr Z

2017-11-03

All the preamplifiers dedicated for Quartz Enhanced PhotoAcoustic Spectroscopy (QEPAS) applications that have so far been reported in the literature have been based on operational amplifiers working in transimpedance configurations. Taking into consideration that QEPAS sensors are based on quartz tuning forks, and that quartz has a relatively high voltage constant and relatively low charge constant, it seems that a transimpedance amplifier is not an optimal solution. This paper describes the design of a quartz QEPAS sensor preamplifier, implemented with voltage amplifier configuration. Discussion of an electrical model of the circuit and preliminary measurements are presented. Both theoretical analysis and experiments show that use of the voltage configuration allows for a substantial increase of the output signal in comparison to the transimpedance circuit with the same tuning fork working in identical conditions. Assuming that the sensitivity of the QEPAS technique depends directly on the properties of the preamplifier, use of the voltage amplifier configuration should result in an increase of QEPAS sensitivity by one to two orders of magnitude.

Tuning Forks and Monitor Screens.

ERIC Educational Resources Information Center

Harrison, M. A. T.

2000-01-01

Defines the vibrations of a tuning fork against a computer monitor screen as a pattern that can illustrate or explain physical concepts like wave vibrations, wave forms, and phase differences. Presents background information and demonstrates the experiment. (Author/YDS)

Chemical bond imaging using higher eigenmodes of tuning fork sensors in atomic force microscopy

NASA Astrophysics Data System (ADS)

Ebeling, Daniel; Zhong, Qigang; Ahles, Sebastian; Chi, Lifeng; Wegner, Hermann A.; Schirmeisen, André

2017-05-01

We demonstrate the ability of resolving the chemical structure of single organic molecules using non-contact atomic force microscopy with higher normal eigenmodes of quartz tuning fork sensors. In order to achieve submolecular resolution, CO-functionalized tips at low temperatures are used. The tuning fork sensors are operated in ultrahigh vacuum in the frequency modulation mode by exciting either their first or second eigenmode. Despite the high effective spring constant of the second eigenmode (on the order of several tens of kN/m), the force sensitivity is sufficiently high to achieve atomic resolution above the organic molecules. This is observed for two different tuning fork sensors with different tip geometries (small tip vs. large tip). These results represent an important step towards resolving the chemical structure of single molecules with multifrequency atomic force microscopy techniques where two or more eigenmodes are driven simultaneously.

Quartz tuning fork-based photodetector for mid-infrared laser spectroscopy

NASA Astrophysics Data System (ADS)

Ding, Junya; He, Tianbo; Zhou, Sheng; Zhang, Lei; Li, Jingsong

2018-05-01

In this paper, we report a new type of photoelectric detector based on a standard quartz crystal tuning fork (QCTF) with resonant frequency of 32 kHz for spectroscopic applications. Analogous to the photoelectric effect of traditional semiconductor detectors, we utilize the piezoelectric effect of the QCTF to gauge the light intensity. To explore the capabilities of this technique, the impact of incident light beam excitation positions with respect to QCTF on signal amplitude, resonant frequency and Q factor, as well as the dependence on incident light intensity, ambient pressure and temperature, was investigated in detail. Finally, the QCTF-based photodetector was successfully demonstrated for qualitative analysis of gasoline components by combing a broadband tunable external cavity quantum cascade laser.

Quantitative measurements of nanoscale permittivity and conductivity using tuning-fork-based microwave impedance microscopy

NASA Astrophysics Data System (ADS)

Wu, Xiaoyu; Hao, Zhenqi; Wu, Di; Zheng, Lu; Jiang, Zhanzhi; Ganesan, Vishal; Wang, Yayu; Lai, Keji

2018-04-01

We report quantitative measurements of nanoscale permittivity and conductivity using tuning-fork (TF) based microwave impedance microscopy (MIM). The system is operated under the driving amplitude modulation mode, which ensures satisfactory feedback stability on samples with rough surfaces. The demodulated MIM signals on a series of bulk dielectrics are in good agreement with results simulated by finite-element analysis. Using the TF-MIM, we have visualized the evolution of nanoscale conductance on back-gated MoS2 field effect transistors, and the results are consistent with the transport data. Our work suggests that quantitative analysis of mesoscopic electrical properties can be achieved by near-field microwave imaging with small distance modulation.

Principles and Applications of the qPlus Sensor

NASA Astrophysics Data System (ADS)

Giessibl, Franz J.

The concept of the atomic force microscope (AFM) is a very simple one: map the surface of a sample by a sharp probe that scans over the surface similar to the finger of a blind person that reads Braille characters. In AFM, the role of that finger is taken by the probe tip that senses the presence of the sample surface by detecting the force between the tip of the probe and a sample. The qPlus sensor is a self sensing cantilever based on a quartz tuning fork that supplements the traditional microfabricated cantilevers made of silicon. Quartz tuning forks are used in the watch industry in quantities of billions annually, with the positive effects on quality and perfection. Three properties of these quartz-based sensors simplify the AFM significantly: (1) the piezoelectricity of quartz allows simple self sensing, (2) the mechanical properties of quartz show very small variations with temperature, and (3) the given stiffness of many quartz tuning forks is close to the ideal stiffness of cantilevers. The key properties of the qPlus sensor are a large stiffness that allows small amplitude operation, the large size that allows to mount single-crystal probe tips, and the self-sensing piezoelectric detection mechanism.

An enhanced low-frequency vibration ZnO nanorod-based tuning fork piezoelectric nanogenerator.

PubMed

Deng, Weili; Jin, Long; Chen, Yueqi; Chu, Wenjun; Zhang, Binbin; Sun, Huan; Xiong, Da; Lv, Zekai; Zhu, Minhao; Yang, Weiqing

2018-01-03

In this paper, a piezoelectric nanogenerator (PENG) based on a tuning fork-shaped cantilever was designed and fabricated, aiming at harvesting low frequency vibration energy in the environment. In the PENG, a tuning fork-shaped elastic beam combined with ZnO nanorods (NRs), instead of conventional rectangular cantilever beams, was adopted to extract vibration energy. Benefiting from the high flexibility and the controllable shape of the substrate, this PENG was extremely sensitive to vibration and can harvest weak vibration energy at a low frequency. Moreover, a series of simulation models were established to compare the performance of the PENG with that of different shapes. On this basis, the experimental results further verify that this designed energy harvester could operate at a low frequency which was about 13 Hz. The peak output voltage and current could respectively reach about 160 mV and 11 nA, and a maximum instantaneous peak power of 0.92 μW cm -3 across a matched load of 9 MΩ was obtained. Evidently, this newly designed PENG could harvest vibration energy at a lower frequency, which will contribute to broaden the application range of the PENG in energy harvesting and self-powered systems.

Superfluidity of 4He in dense aerogel studied using quartz tuning fork

NASA Astrophysics Data System (ADS)

Matsumoto, K.; Okamoto, R.; Nakajima, A.; Abe, S.

2018-03-01

Superfluid 4He in aerogel is of interest because it has a normal component coupling to gel strand due to viscosity and a superfluid component with zero viscosity. Superfluid helium in aerogel has two sound modes, a slow critical mode and a fast one. In this study, quartz tuning fork was used in order to study acoustic properties of liquid 4He in aerogel with 90% porosity. Two pieces of aerogel were glued on both prongs of quartz tuning fork that had a resonance frequency of 33 kHz. The tuning fork was immersed in liquid 4He from 2 to 20 bar. The resonance frequency increased in the superfluid phase due to decrease in loaded mass. Temperature variation of resonance frequency was explained by that of superfluid density. Superfluid transition in aerogel was 2 mK lower than that without gel. Additional dissipation was observed in the temperature range between 1 K and transition temperature.

Note: Wide band amplifier for quartz tuning fork sensors with digitally controlled stray capacitance compensation.

PubMed

Peng, Ping; Hao, Lifeng; Ding, Ning; Jiao, Weicheng; Wang, Qi; Zhang, Jian; Wang, Rongguo

2015-11-01

We presented a preamplifier design for quartz tuning fork (QTF) sensors in which the stray capacitance is digitally compensated. In this design, the manually controlled variable capacitor is replaced by a pair of varicap diodes, whose capacitance could be accurately tuned by a bias voltage. A tuning circuit including a single side low power operational amplifier, a digital-to-analog converter, and a microprocessor is also described, and the tuning process can be conveniently carried out on a personal computer. For the design, the noise level was investigated experimentally.

Scanning thermal microscopy based on a quartz tuning fork and a micro-thermocouple in active mode (2ω method).

PubMed

Bontempi, Alexia; Nguyen, Tran Phong; Salut, Roland; Thiery, Laurent; Teyssieux, Damien; Vairac, Pascal

2016-06-01

A novel probe for scanning thermal microscope using a micro-thermocouple probe placed on a Quartz Tuning Fork (QTF) is presented. Instead of using an external deflection with a cantilever beam for contact detection, an original combination of piezoelectric resonator and thermal probe is employed. Due to a non-contact photothermal excitation principle, the high quality factor of the QTF allows the probe-to-surface contact detection. Topographic and thermal scanning images obtained on a specific sample points out the interest of our system as an alternative to cantilevered resistive probe systems which are the most spread.

Scanning thermal microscopy based on a quartz tuning fork and a micro-thermocouple in active mode (2ω method)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bontempi, Alexia; Nguyen, Tran Phong; Salut, Roland

A novel probe for scanning thermal microscope using a micro-thermocouple probe placed on a Quartz Tuning Fork (QTF) is presented. Instead of using an external deflection with a cantilever beam for contact detection, an original combination of piezoelectric resonator and thermal probe is employed. Due to a non-contact photothermal excitation principle, the high quality factor of the QTF allows the probe-to-surface contact detection. Topographic and thermal scanning images obtained on a specific sample points out the interest of our system as an alternative to cantilevered resistive probe systems which are the most spread.

Quantitative measurements of nanoscale permittivity and conductivity using tuning-fork-based microwave impedance microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Xiaoyu; Hao, Zhenqi; Wu, Di

Here, we report quantitative measurements of nanoscale permittivity and conductivity using tuning-fork (TF) based microwave impedance microscopy (MIM). The system is operated under the driving amplitude modulation mode, which ensures satisfactory feedback stability on samples with rough surfaces. The demodulated MIM signals on a series of bulk dielectrics are in good agreement with results simulated by finite-element analysis. Using the TF-MIM, we have visualized the evolution of nanoscale conductance on back-gated MoS 2 field effect transistors, and the results are consistent with the transport data. Our work suggests that quantitative analysis of mesoscopic electrical properties can be achieved by near-fieldmore » microwave imaging with small distance modulation.« less

Quantitative measurements of nanoscale permittivity and conductivity using tuning-fork-based microwave impedance microscopy

DOE PAGES

Wu, Xiaoyu; Hao, Zhenqi; Wu, Di; ...

2018-04-01

Here, we report quantitative measurements of nanoscale permittivity and conductivity using tuning-fork (TF) based microwave impedance microscopy (MIM). The system is operated under the driving amplitude modulation mode, which ensures satisfactory feedback stability on samples with rough surfaces. The demodulated MIM signals on a series of bulk dielectrics are in good agreement with results simulated by finite-element analysis. Using the TF-MIM, we have visualized the evolution of nanoscale conductance on back-gated MoS 2 field effect transistors, and the results are consistent with the transport data. Our work suggests that quantitative analysis of mesoscopic electrical properties can be achieved by near-fieldmore » microwave imaging with small distance modulation.« less

Atomic resolution ultrafast scanning tunneling microscope with scan rate breaking the resonant frequency of a quartz tuning fork resonator.

PubMed

Li, Quanfeng; Lu, Qingyou

2011-05-01

We present an ultra-fast scanning tunneling microscope with atomic resolution at 26 kHz scan rate which surpasses the resonant frequency of the quartz tuning fork resonator used as the fast scan actuator. The main improvements employed in achieving this new record are (1) fully low voltage design (2) independent scan control and data acquisition, where the tuning fork (carrying a tip) is blindly driven to scan by a function generator with the scan voltage and tunneling current (I(T)) being measured as image data (this is unlike the traditional point-by-point move and measure method where data acquisition and scan control are switched many times).

Note: a transimpedance amplifier for remotely located quartz tuning forks.

PubMed

Kleinbaum, Ethan; Csáthy, Gábor A

2012-12-01

The cable capacitance in cryogenic and high vacuum applications of quartz tuning forks imposes severe constraints on the bandwidth and noise performance of the measurement. We present a single stage low noise transimpedance amplifier with a bandwidth exceeding 1 MHz and provide an in-depth analysis of the dependence of the amplifier parameters on the cable capacitance.

Quartz tuning fork-based frequency modulation atomic force spectroscopy and microscopy with all digital phase-locked loop

NASA Astrophysics Data System (ADS)

An, Sangmin; Hong, Mun-heon; Kim, Jongwoo; Kwon, Soyoung; Lee, Kunyoung; Lee, Manhee; Jhe, Wonho

2012-11-01

We present a platform for the quartz tuning fork (QTF)-based, frequency modulation atomic force microscopy (FM-AFM) system for quantitative study of the mechanical or topographical properties of nanoscale materials, such as the nano-sized water bridge formed between the quartz tip (˜100 nm curvature) and the mica substrate. A thermally stable, all digital phase-locked loop is used to detect the small frequency shift of the QTF signal resulting from the nanomaterial-mediated interactions. The proposed and demonstrated novel FM-AFM technique provides high experimental sensitivity in the measurement of the viscoelastic forces associated with the confined nano-water meniscus, short response time, and insensitivity to amplitude noise, which are essential for precision dynamic force spectroscopy and microscopy.

Quartz tuning fork-based frequency modulation atomic force spectroscopy and microscopy with all digital phase-locked loop.

PubMed

An, Sangmin; Hong, Mun-heon; Kim, Jongwoo; Kwon, Soyoung; Lee, Kunyoung; Lee, Manhee; Jhe, Wonho

2012-11-01

We present a platform for the quartz tuning fork (QTF)-based, frequency modulation atomic force microscopy (FM-AFM) system for quantitative study of the mechanical or topographical properties of nanoscale materials, such as the nano-sized water bridge formed between the quartz tip (~100 nm curvature) and the mica substrate. A thermally stable, all digital phase-locked loop is used to detect the small frequency shift of the QTF signal resulting from the nanomaterial-mediated interactions. The proposed and demonstrated novel FM-AFM technique provides high experimental sensitivity in the measurement of the viscoelastic forces associated with the confined nano-water meniscus, short response time, and insensitivity to amplitude noise, which are essential for precision dynamic force spectroscopy and microscopy.

Quartz enhanced photoacoustic spectroscopy based trace gas sensors using different quartz tuning forks.

PubMed

Ma, Yufei; Yu, Guang; Zhang, Jingbo; Yu, Xin; Sun, Rui; Tittel, Frank K

2015-03-27

A sensitive trace gas sensor platform based on quartz-enhanced photoacoustic spectroscopy (QEPAS) is reported. A 1.395 μm continuous wave (CW), distributed feedback pigtailed diode laser was used as the excitation source and H2O was selected as the target analyte. Two kinds of quartz tuning forks (QTFs) with a resonant frequency (f0) of 30.72 kHz and 38 kHz were employed for the first time as an acoustic wave transducer, respectively for QEPAS instead of a standard QTF with a f0 of 32.768 kHz. The QEPAS sensor performance using the three different QTFs was experimentally investigated and theoretically analyzed. A minimum detection limit of 5.9 ppmv and 4.3 ppmv was achieved for f0 of 32.768 kHz and 30.72 kHz, respectively.

Noncontact atomic force microscopy in liquid environment with quartz tuning fork and carbon nanotube probe

NASA Astrophysics Data System (ADS)

Kageshima, Masami; Jensenius, Henriette; Dienwiebel, Martin; Nakayama, Yoshikazu; Tokumoto, Hiroshi; Jarvis, Suzanne P.; Oosterkamp, Tjerk H.

2002-03-01

A force sensor for noncontact atomic force microscopy in liquid environment was developed by combining a multiwalled carbon nanotube (MWNT) probe with a quartz tuning fork. Solvation shells of octamethylcyclotetrasiloxane on a graphite surface were detected both in the frequency shift and dissipation. Due to the high aspect ratio of the CNT probe, the long-range background force was barely detectable in the solvation region.

Frequency shift, damping, and tunneling current coupling with quartz tuning forks in noncontact atomic force microscopy

NASA Astrophysics Data System (ADS)

Nony, Laurent; Bocquet, Franck; Para, Franck; Loppacher, Christian

2016-09-01

A combined experimental and theoretical approach to the coupling between frequency-shift (Δ f ) , damping, and tunneling current (It) in combined noncontact atomic force microscopy/scanning tunneling microscopy using quartz tuning forks (QTF)-based probes is reported. When brought into oscillating tunneling conditions, the tip located at the QTF prong's end radiates an electromagnetic field which couples to the QTF prong motion via its piezoelectric tensor and loads its electrodes by induction. Our approach explains how those It-related effects ultimately modify the Δ f and the damping measurements. This paradigm to the origin of the coupling between It and the nc-AFM regular signals relies on both the intrinsic piezoelectric nature of the quartz constituting the QTF and its electrodes design.

Development of an ICT-Based Air Column Resonance Learning Media

NASA Astrophysics Data System (ADS)

Purjiyanta, Eka; Handayani, Langlang; Marwoto, Putut

2016-08-01

Commonly, the sound source used in the air column resonance experiment is the tuning fork having disadvantage of unoptimal resonance results due to the sound produced which is getting weaker. In this study we made tones with varying frequency using the Audacity software which were, then, stored in a mobile phone as a source of sound. One advantage of this sound source is the stability of the resulting sound enabling it to produce the same powerful sound. The movement of water in a glass tube mounted on the tool resonance and the tone sound that comes out from the mobile phone were recorded by using a video camera. Sound resonances recorded were first, second, and third resonance, for each tone frequency mentioned. The resulting sound stays longer, so it can be used for the first, second, third and next resonance experiments. This study aimed to (1) explain how to create tones that can substitute tuning forks sound used in air column resonance experiments, (2) illustrate the sound wave that occurred in the first, second, and third resonance in the experiment, and (3) determine the speed of sound in the air. This study used an experimental method. It was concluded that; (1) substitute tones of a tuning fork sound can be made by using the Audacity software; (2) the form of sound waves that occured in the first, second, and third resonance in the air column resonance can be drawn based on the results of video recording of the air column resonance; and (3) based on the experiment result, the speed of sound in the air is 346.5 m/s, while based on the chart analysis with logger pro software, the speed of sound in the air is 343.9 ± 0.3171 m/s.

Interface circuit for a multiple-beam tuning-fork gyroscope with high quality factors

NASA Astrophysics Data System (ADS)

Wang, Ren

This research work presents the design, theoretical analysis, fabrication, interface electronics, and experimental results of a Silicon-On-Insulator (SOI) based Multiple-Beam Tuning-Fork Gyroscope (MB-TFG). Based on a numerical model of Thermo-Elastic Damping (TED), a Multiple-Beam Tuning-Fork Structure (MB-TFS) is designed with high Quality factors (Qs) in its two operation modes. A comprehensive theoretical analysis of the MB-TFG design is conducted to relate the design parameters to its operation parameters and further performance parameters. In conjunction with a mask that defines the device through trenches to alleviate severe fabrication effect on anchor loss, a simple one-mask fabrication process is employed to implement this MB-TFG design on SOI wafers. The fabricated MB-TFGs are tested with PCB-level interface electronics and a thorough comparison between the experimental results and a theoretical analysis is conducted to verify the MB-TFG design and accurately interpret the measured performance. The highest measured Qs of the fabricated MB-TFGs in vacuum are 255,000 in the drive-mode and 103,000 in the sense-mode, at a frequency of 15.7kHz. Under a frequency difference of 4Hz between the two modes (operation frequency is 16.8kHz) and a drive-mode vibration amplitude of 3.0um, the measured rate sensitivity is 80mVpp/°/s with an equivalent impedance of 6MQ. The calculated overall rate resolution of this device is 0.37/hrhiElz, while the measured Angle Random Walk (ARW) and bias instability are 6.67°/'vhr and 95°/hr, respectively.

A single active nanoelectromechanical tuning fork front-end radio-frequency receiver

NASA Astrophysics Data System (ADS)

Bartsch, Sebastian T.; Rusu, A.; Ionescu, Adrian M.

2012-06-01

Nanoelectromechanical systems (NEMS) offer the potential to revolutionize fundamental methods employed for signal processing in today’s telecommunication systems, owing to their spectral purity and the prospect of integration with existing technology. In this work we present a novel, front-end receiver topology based on a single device silicon nanoelectromechanical mixer-filter. The operation is demonstrated by using the signal amplification in a field effect transistor (FET) merged into a tuning fork resonator. The combination of both a transistor and a mechanical element into a hybrid unit enables on-chip functionality and performance previously unachievable in silicon. Signal mixing, filtering and demodulation are experimentally demonstrated at very high frequencies ( > 100 MHz), maintaining a high quality factor of Q = 800 and stable operation at near ambient pressure (0.1 atm) and room temperature (T = 300 K). The results show that, ultimately miniaturized, silicon NEMS can be utilized to realize multi-band, single-chip receiver systems based on NEMS mixer-filter arrays with reduced system complexity and power consumption.

Piezoelectric tuning fork biosensors for the quantitative measurement of biomolecular interactions

NASA Astrophysics Data System (ADS)

Gonzalez, Laura; Rodrigues, Mafalda; Benito, Angel Maria; Pérez-García, Lluïsa; Puig-Vidal, Manel; Otero, Jorge

2015-12-01

The quantitative measurement of biomolecular interactions is of great interest in molecular biology. Atomic force microscopy (AFM) has proved its capacity to act as a biosensor and determine the affinity between biomolecules of interest. Nevertheless, the detection scheme presents certain limitations when it comes to developing a compact biosensor. Recently, piezoelectric quartz tuning forks (QTFs) have been used as laser-free detection sensors for AFM. However, only a few studies along these lines have considered soft biological samples, and even fewer constitute quantified molecular recognition experiments. Here, we demonstrate the capacity of QTF probes to perform specific interaction measurements between biotin-streptavidin complexes in buffer solution. We propose in this paper a variant of dynamic force spectroscopy based on representing adhesion energies E (aJ) against pulling rates v (nm s-1). Our results are compared with conventional AFM measurements and show the great potential of these sensors in molecular interaction studies.

Photo-thermal quartz tuning fork excitation for dynamic mode atomic force microscope

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bontempi, Alexia; Teyssieux, Damien; Thiery, Laurent

2014-10-13

A photo-thermal excitation of a Quartz Tuning Fork (QTF) for topographic studies is introduced. The non-invasive photo-thermal excitation presents practical advantages compared to QTF mechanical and electrical excitations, including the absence of the anti-resonance and its associated phase rotation. Comparison between our theoretical model and experiments validate that the optical transduction mechanism is a photo-thermal rather than photo-thermoacoustic phenomenon. Topographic maps in the context of near-field microscopy distance control have been achieved to demonstrate the performance of the system.

Operation of a wet near-field scanning optical microscope in stable zones by minimizing the resonance change of tuning forks.

PubMed

Park, Kyoung-Duck; Park, Doo Jae; Lee, Seung Gol; Choi, Geunchang; Kim, Dai-Sik; Byeon, Clare Chisu; Choi, Soo Bong; Jeong, Mun Seok

2014-02-21

A resonant shift and a decrease of resonance quality of a tuning fork attached to a conventional fiber optic probe in the vicinity of liquid is monitored systematically while varying the protrusion length and immersion depth of the probe. Stable zones where the resonance modification as a function of immersion depth is minimized are observed. A wet near-field scanning optical microscope (wet-NSOM) is operated for a sample within water by using such a stable zone.

Double resonator cantilever accelerometer

DOEpatents

Koehler, Dale R.

1984-01-01

A digital quartz accelerometer includes a pair of spaced double-ended tuning forks fastened at one end to a base and at the other end through a spacer mass. Transverse movement of the resonator members stresses one and compresses the other, providing a differential frequency output which is indicative of acceleration.

Contralateral Occlusion Test: The effect of external ear canal occlusion on hearing thresholds.

PubMed

Reis, Luis Roque; Fernandes, Paulo; Escada, Pedro

Bedside testing with tuning forks may decrease turnaround time and improve decision making for a quick qualitative assessment of hearing loss. The purpose of this study was to quantify the effects of ear canal occlusion on hearing, in order to decide which tuning fork frequency is more appropriate to use for quantifying hearing loss with the Contralateral Occlusion Test. Twenty normal-hearing adults (forty ears) underwent sound field pure tone audiometry with and without ear canal occlusion. Each ear was tested with the standard frequencies. The contralateral ear was suppressed with by masking. Ear occlusion was performed by two examiners. Participants aged between 21 and 30 years (25.6±3.03 years) showed an increase in hearing thresholds with increasing frequencies from 19.94dB (250Hz) to 39.25dB (2000Hz). The threshold difference between occluded and unoccluded conditions was statistically significant and increased from 10.69dB (250Hz) to 32.12dB (2000Hz). There were no statistically significant differences according to gender or between the examiners. The occlusion effect increased the hearing thresholds and became more evident with higher frequencies. The occlusion method as performed demonstrated reproducibility. In the Contralateral Occlusion Test, 256Hz or 512Hz tuning forks should be used for diagnosis of mild hearing loss, and a 2048Hz tuning fork should be used for moderate hearing loss. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.

Flow field and oscillatory shear stress in a tuning-fork-shaped model of the average human carotid bifurcation.

PubMed

Ding, Z; Wang, K; Li, J; Cong, X

2001-12-01

The oscillatory shear index (OSI) was developed based on the hypothesis that intimal hyperplasia was correlated with oscillatory shear stresses. However, the validity of the OSI was in question since the correlation between intimal thickness and the OSI at the side walls of the sinus in the Y-shaped model of the average human carotid bifurcation (Y-AHCB) was weak. The objectives of this paper are to examine whether the reason for the weak correlation lies in the deviation in geometry of Y-AHCB from real human carotid bifurcation, and whether this correlation is clearly improved in the tuning-fork-shaped model of the average human carotid bifurcation (TF-AHCB). The geometry of the TF-AHCB model was based on observation and statistical analysis of specimens from 74 cadavers. The flow fields in both models were studied and compared by using flow visualization methods under steady flow conditions and by using laser Doppler anemometer (LDA) under pulsatile flow conditions. The TF-shaped geometry leads to a more complex flow field than the Y-shaped geometry. This added complexity includes strengthened helical movements in the sinus, new flow separation zone, and directional changes in the secondary flow patterns. The results show that the OSI-values at the side walls of the sinus in the TF-shaped model were more than two times as large as those in the Y-shaped model. This study confirmed the stronger correlation between the OSI and intimal thickness in the tuning-fork geometry of human carotid bifurcation, and the TF-AHCB model is a significant improvement over the traditional Y-shaped model.

Compact all-fiber quartz-enhanced photoacoustic spectroscopy sensor with a 30.72 kHz quartz tuning fork and spatially resolved trace gas detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Yufei, E-mail: mayufei@hit.edu.cn; Post-doctoral Mobile Station of Power Engineering and Engineering Thermophysics, Harbin Institute of Technology, Harbin 150001; He, Ying

An ultra compact all-fiber quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor using quartz tuning fork (QTF) with a low resonance frequency of 30.72 kHz was demonstrated. Such a sensor architecture has the advantages of easier optical alignment, lower insertion loss, lower cost, and more compact compared with a conventional QEPAS sensor using discrete optical components for laser delivery and coupling to the QTF. A fiber beam splitter and three QTFs were employed to perform multi-point detection and demonstrated the potential of spatially resolved measurements.

The conventional tuning fork as a quantitative tool for vibration threshold.

PubMed

Alanazy, Mohammed H; Alfurayh, Nuha A; Almweisheer, Shaza N; Aljafen, Bandar N; Muayqil, Taim

2018-01-01

This study was undertaken to describe a method for quantifying vibration when using a conventional tuning fork (CTF) in comparison to a Rydel-Seiffer tuning fork (RSTF) and to provide reference values. Vibration thresholds at index finger and big toe were obtained in 281 participants. Spearman's correlations were performed. Age, weight, and height were analyzed for their covariate effects on vibration threshold. Reference values at the fifth percentile were obtained by quantile regression. The correlation coefficients between CTF and RSTF values at finger/toe were 0.59/0.64 (P = 0.001 for both). Among covariates, only age had a significant effect on vibration threshold. Reference values for CTF at finger/toe for the age groups 20-39 and 40-60 years were 7.4/4.9 and 5.8/4.6 s, respectively. Reference values for RSTF at finger/toe for the age groups 20-39 and 40-60 years were 6.9/5.5 and 6.2/4.7, respectively. CTF provides quantitative values that are as good as those provided by RSTF. Age-stratified reference data are provided. Muscle Nerve 57: 49-53, 2018. © 2017 Wiley Periodicals, Inc.

Comparison of quartz tuning forks and AlN-based extensional microresonators for viscosity measurements in oil/fuel mixtures

NASA Astrophysics Data System (ADS)

Toledo, J.; Manzaneque, T.; Hernando-García, J.; Vazquez, J.; Ababneh, A.; Seidel, H.; Lapuerta, M.; Sánchez-Rojas, J. L.

2013-05-01

In-situ monitoring of the physical properties of liquids is of great interest in the automotive industry. For example, lubricants are subject to dilution with diesel fuel as a consequence of late-injection processes, which are necessary for regenerating diesel particulate filters. This dilution can be determined by tracking the viscosity and the density of the lubricant. Here we report the test of two in-plane movement based resonators to explore their capability to monitor oil dilution with diesel and biodiesel. One of the resonators is the commercially available millimeter-sized quartz tuning fork, working at 32.7 kHz. The second resonator is a state-of-the-art micron-sized AlN-based rectangular plate, actuated in the first extensional mode in the MHz range. Electrical impedance measurements were carried out to characterize the performance of the structures in various liquid media in a wide range of viscosities. These measurements were completed with the development of low-cost electronic circuits to track the resonance frequency and the quality factor automatically, these two parameters allow to obtain the viscosity of various fluids under investigation, as in the case of dilution of lubricant SAE 15W40 and biodiesel.

Quartz enhanced photoacoustic H{sub 2}S gas sensor based on a fiber-amplifier source and a custom tuning fork with large prong spacing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Hongpeng; Liu, Xiaoli; Zheng, Huadan

2015-09-14

A quartz enhanced photoacoustic spectroscopy (QEPAS) sensor, employing an erbium-doped fiber amplified laser source and a custom quartz tuning fork (QTF) with its two prongs spaced ∼800 μm apart, is reported. The sensor employs an acoustic micro-resonator (AmR) which is assembled in an “on-beam” QEPAS configuration. Both length and vertical position of the AmR are optimized in terms of signal-to-noise ratio, significantly improving the QEPAS detection sensitivity by a factor of ∼40, compared to the case of a sensor using a bare custom QTF. The fiber-amplifier-enhanced QEPAS sensor is applied to H{sub 2}S trace gas detection, reaching a sensitivity of ∼890 ppbmore » at 1 s integration time, similar to those obtained with a power-enhanced QEPAS sensor equipped with a standard QTF, but with the advantages of easy optical alignment, simple installation, and long-term stability.« less

Chemical and biological sensing using tuning forks

DOEpatents

Tao, Nongjian; Boussaad, Salah

2012-07-10

A device for sensing a chemical analyte is disclosed. The device is comprised of a vibrating structure having first and second surfaces and having an associated resonant frequency and a wire coupled between the first and second surfaces of the vibrating structure, wherein the analyte interacts with the wire and causes a change in the resonant frequency of the vibrating structure. The vibrating structure can include a tuning fork. The vibrating structure can be comprised of quartz. The wire can be comprised of polymer. A plurality of vibrating structures are arranged in an array to increase confidence by promoting a redundancy of measurement or to detect a plurality of chemical analytes. A method of making a device for sensing a chemical analyte is also disclosed.

A New Resonance Tube

NASA Astrophysics Data System (ADS)

Bates, Alan

2017-12-01

The measurement of the speed of sound in air with the resonance tube is a popular experiment that often yields accurate results. One approach is to hold a vibrating tuning fork over an air column that is partially immersed in water. The column is raised and lowered in the water until the generated standing wave produces resonance: this occurs at the point where sound is perceived to have maximum loudness, or at the point where the amplitude of the standing wave has maximum value, namely an antinode. An antinode coincides with the position of the tuning fork, beyond the end of the air column, which consequently introduces an end correction. One way to minimize this end correction is to measure the distance between consecutive antinodes.

MEMS vibrating-beam accelerometer with piezoelectric drive

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strehlow, John; MacGugan, Doug

A high-temperature drive component for a double-ended tuning fork (DETF). The drive component attaches to a surface of at least one of the tines. The drive component includes at least one piezoelectric trace sandwiched at least partially between two electrical traces. At least one of the tines includes a doped silicon base with drive component located thereon. One of the electrical traces is electrically connected to the doped silicon base and the other is electrically isolated from the doped silicon base.

Sensing Performance Analysis on Quartz Tuning Fork-Probe at the High Order Vibration Mode for Multi-Frequency Scanning Probe Microscopy

PubMed Central

Gao, Fengli; Li, Xide

2018-01-01

Multi-frequency scanning near-field optical microscopy, based on a quartz tuning fork-probe (QTF-p) sensor using the first two orders of in-plane bending symmetrical vibration modes, has recently been developed. This method can simultaneously achieve positional feedback (based on the 1st in-plane mode called the low mode) and detect near-field optically induced forces (based on the 2nd in-plane mode called the high mode). Particularly, the high mode sensing performance of the QTF-p is an important issue for characterizing the tip-sample interactions and achieving higher resolution microscopic imaging but the related researches are insufficient. Here, we investigate the vibration performance of QTF-p at high mode based on the experiment and finite element method. The frequency spectrum characteristics are obtained by our homemade laser Doppler vibrometer system. The effects of the properties of the connecting glue layer and the probe features on the dynamic response of the QTF-p sensor at the high mode are investigated for optimization design. Finally, compared with the low mode, an obvious improvement of quality factor, of almost 50%, is obtained at the high mode. Meanwhile, the QTF-p sensor has a high force sensing sensitivity and a large sensing range at the high mode, indicating a broad application prospect for force sensing. PMID:29364847

Optimizing qPlus sensor assemblies for simultaneous scanning tunneling and noncontact atomic force microscopy operation based on finite element method analysis

DOE PAGES

Dagdeviren, Omur E.; Schwarz, Udo D.

2017-03-20

Quartz tuning forks that have a probe tip attached to the end of one of its prongs while the other prong is arrested to a holder (“qPlus” configuration) have gained considerable popularity in recent years for high-resolution atomic force microscopy imaging. The small size of the tuning forks and the complexity of the sensor architecture, however, often impede predictions on how variations in the execution of the individual assembly steps affect the performance of the completed sensor. Extending an earlier study that provided numerical analysis of qPlus-style setups without tips, this work quantifies the influence of tip attachment on themore » operational characteristics of the sensor. The results using finite element modeling show in particular that for setups that include a metallic tip that is connected via a separate wire to enable the simultaneous collection of local forces and tunneling currents, the exact realization of this wire connection has a major effect on sensor properties such as spring constant, quality factor, resonance frequency, and its deviation from an ideal vertical oscillation.« less

Optimizing qPlus sensor assemblies for simultaneous scanning tunneling and noncontact atomic force microscopy operation based on finite element method analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dagdeviren, Omur E.; Schwarz, Udo D.

Quartz tuning forks that have a probe tip attached to the end of one of its prongs while the other prong is arrested to a holder (“qPlus” configuration) have gained considerable popularity in recent years for high-resolution atomic force microscopy imaging. The small size of the tuning forks and the complexity of the sensor architecture, however, often impede predictions on how variations in the execution of the individual assembly steps affect the performance of the completed sensor. Extending an earlier study that provided numerical analysis of qPlus-style setups without tips, this work quantifies the influence of tip attachment on themore » operational characteristics of the sensor. The results using finite element modeling show in particular that for setups that include a metallic tip that is connected via a separate wire to enable the simultaneous collection of local forces and tunneling currents, the exact realization of this wire connection has a major effect on sensor properties such as spring constant, quality factor, resonance frequency, and its deviation from an ideal vertical oscillation.« less

Evanescent-wave photoacoustic spectroscopy with optical micro/nano fibers.

PubMed

Cao, Yingchun; Jin, Wei; Ho, Lut Hoi; Liu, Zhibo

2012-01-15

We demonstrate gas detection based on evanescent-wave photoacoustic (PA) spectroscopy with tapered optical fibers. Evanescent-field instead of open-path absorption is exploited for PA generation, and a quartz tuning fork is used for PA detection. A tapered optical fiber with a diameter down to the wavelength scale demonstrates detection sensitivity similar to an open-path system but with the advantages of easier optical alignment, smaller insertion loss, and multiplexing capability.

A High-Q AFM Sensor Using a Balanced Trolling Quartz Tuning Fork in the Liquid

PubMed Central

Li, Yingzi; Song, Zihang; Lin, Rui; Chen, Yifu; Qian, Jianqiang

2018-01-01

A quartz tuning fork (QTF) has been widely used as a force sensor of the frequency modulation atomic force microscope due to its ultrahigh stiffness, high quality factor and self-sensing nature. However, due to the bulky structure and exposed surface electrode arrangement, its application is limited, especially in liquid imaging of in situ biological samples, ionic liquids, electrochemical reaction, etc. Although the complication can be resolved by coating insulating materials on the QTF surface and then immersing the whole QTF into the liquid, it would result in a sharp drop of the quality factor, which will reduce the sensitivity of the QTF. To solve the problem, a novel method, called the balanced trolling quartz tuning fork (BT-QTF), is introduced here. In this method, two same probes are glued on both prongs of the QTF separately while only one probe immersed in the liquid. With the method, the hydrodynamic interaction can be reduced, thus the BT-QTF can retain a high quality factor and constant resonance frequency. The stable small vibration of the BT-QTF can be achieved in the liquid. Initially, a theoretical model is presented to analyze the sensing performance of the BT-QTF in the liquid. Then, the sensing performance analysis experiments of the BT-QTF have been performed. At last, the proposed method is applied to atomic force microscope imaging different samples in the liquid, which proves its feasibility. PMID:29783740

The effects of Vibro-medical insole on vibrotactile sensation in diabetic patients with mild-to-moderate peripheral neuropathy.

PubMed

Bagherzadeh Cham, Masumeh; Mohseni-Bandpei, Mohammad Ali; Bahramizadeh, Mahmood; Kalbasi, Saeed; Biglarian, Akbar

2018-06-01

Peripheral sensory neuropathy seems to be the main risk factor for diabetic foot ulceration. Previous studies demonstrated that stochastic resonance can improve the vibrotactile sensation of diabetic patients. The aim of this study was to evaluate the effects of Vibro-medical insole on pressure and vibration sensation in diabetic patients with mild-to-moderate peripheral neuropathy. A total of 20 patients with mild-to-moderate diabetic neuropathy were included in the pre-test and post-test clinical trial study. Vibro-medical insole consists of medical insole and vibratory system. Medical insole was made independently for each participant and vibratory system was inserted in it. Pressure and vibration sensation were evaluated before and after 30-min walking with Vibro-medical insole. Semmes-Weinstein monofilaments and tuning fork were used to evaluate pressure and vibration sensation, respectively. Pressure sensation showed significantly improvement using Vibro-medical insole at the heel, first and fifth metatarsophalangeal heads, and hallux of both feet in all participants (p < 0.001). Vibration sensation also improved at the big toe of both feet with 256 Hz tuning fork (p < 0.05) but no statistically significant effect was found with 128 Hz tuning fork (p > 0.05). Vibro-medical insole significantly improved pressure and vibration sensation of the foot in diabetic patients with mild-to-moderate peripheral neuropathy. The results suggest that Vibro-medical insole can be used for daily living activities to overcome sensory loss in diabetic neuropathy patients.

DNA Meter: Energy Tunable, Quantitative Hybridization Assay

PubMed Central

Braunlin, William; Völker, Jens; Plum, G. Eric; Breslauer, Kenneth J.

2015-01-01

We describe a novel hybridization assay that employs a unique class of energy tunable, bulge loop-containing competitor strands (C*) that hybridize to a probe strand (P). Such initial “pre-binding” of a probe strand modulates its effective “availability” for hybridizing to a target site (T). More generally, the assay described here is based on competitive binding equilibria for a common probe strand (P) between such tunable competitor strands (C*) and a target strand (T). We demonstrate that loop variable, energy tunable families of C*P complexes exhibit enhanced discrimination between targets and mismatched targets, thereby reducing false positives/negatives. We refer to a C*P complex between a C* competitor single strand and the probe strand as a “tuning fork,” since the C* strand exhibits branch points (forks) at the duplex-bulge interfaces within the complex. By varying the loop to create families of such “tuning forks,” one can construct C*P “energy ladders” capable of resolving small differences within the target that may be of biological/functional consequence. The methodology further allows quantification of target strand concentrations, a determination heretofore not readily available by conventional hybridization assays. The dual ability of this tunable assay to discriminate and quantitate targets provides the basis for developing a technology we refer to as a “DNA Meter.” Here we present data that establish proof-of-principle for an in solution version of such a DNA Meter. We envision future applications of this tunable assay that incorporate surface bound/spatially resolved DNA arrays to yield enhanced discrimination and sensitivity. PMID:23529692

Application of acoustic micro-resonators in quartz-enhanced photoacoustic spectroscopy for trace gas analysis

NASA Astrophysics Data System (ADS)

Zheng, Huadan; Dong, Lei; Wu, Hongpeng; Yin, Xukun; Xiao, Liantuan; Jia, Suotang; Curl, Robert F.; Tittel, Frank K.

2018-01-01

During the past 15 years since the first report of quartz enhanced photoacoustic spectroscopy (QEPAS), QEPAS has become one of the leading optical techniques for trace chemical gas sensing. This paper is a review of the current state-of-the art of QEPAS. QEPAS based spectrophones with different acoustic micro-resonators (AmR) configurations employing both standard quartz tuning forks (QTFs) and custom-made QTFs are summarized and discussed in detail.

A near-field scanning microwave microscope for characterization of inhomogeneous photovoltaics.

PubMed

Weber, J C; Schlager, J B; Sanford, N A; Imtiaz, A; Wallis, T M; Mansfield, L M; Coakley, K J; Bertness, K A; Kabos, P; Bright, V M

2012-08-01

We present a near-field scanning microwave microscope (NSMM) that has been configured for imaging photovoltaic samples. Our system incorporates a Pt-Ir tip inserted into an open-ended coaxial cable to form a weakly coupled resonator, allowing the microwave reflection S(11) signal to be measured across a sample over a frequency range of 1 GHz - 5 GHz. A phase-tuning circuit increased impedance-measurement sensitivity by allowing for tuning of the S(11) minimum down to -78 dBm. A bias-T and preamplifier enabled simultaneous, non-contact measurement of the DC tip-sample current, and a tuning fork feedback system provided simultaneous topographic data. Light-free tuning fork feedback provided characterization of photovoltaic samples both in the dark and under illumination at 405 nm. NSMM measurements were obtained on an inhomogeneous, third-generation Cu(In,Ga)Se(2) (CIGS) sample. The S(11) and DC current features were found to spatially broaden around grain boundaries with the sample under illumination. The broadening is attributed to optically generated charge that becomes trapped and changes the local depletion of the grain boundaries, thereby modifying the local capacitance. Imaging provided by the NSMM offers a new RF methodology to resolve and characterize nanoscale electrical features in photovoltaic materials and devices.

Quartz-Enhanced Photoacoustic Spectroscopy: A Review

PubMed Central

Patimisco, Pietro; Scamarcio, Gaetano; Tittel, Frank K.; Spagnolo, Vincenzo

2014-01-01

A detailed review on the development of quartz-enhanced photoacoustic sensors (QEPAS) for the sensitive and selective quantification of molecular trace gas species with resolved spectroscopic features is reported. The basis of the QEPAS technique, the technology available to support this field in terms of key components, such as light sources and quartz-tuning forks and the recent developments in detection methods and performance limitations will be discussed. Furthermore, different experimental QEPAS methods such as: on-beam and off-beam QEPAS, quartz-enhanced evanescent wave photoacoustic detection, modulation-cancellation approach and mid-IR single mode fiber-coupled sensor systems will be reviewed and analysed. A QEPAS sensor operating in the THz range, employing a custom-made quartz-tuning fork and a THz quantum cascade laser will be also described. Finally, we evaluated data reported during the past decade and draw relevant and useful conclusions from this analysis. PMID:24686729

Experimenting with musical intervals

NASA Astrophysics Data System (ADS)

Lo Presto, Michael C.

2003-07-01

When two tuning forks of different frequency are sounded simultaneously the result is a complex wave with a repetition frequency that is the fundamental of the harmonic series to which both frequencies belong. The ear perceives this 'musical interval' as a single musical pitch with a sound quality produced by the harmonic spectrum responsible for the waveform. This waveform can be captured and displayed with data collection hardware and software. The fundamental frequency can then be calculated and compared with what would be expected from the frequencies of the tuning forks. Also, graphing software can be used to determine equations for the waveforms and predict their shapes. This experiment could be used in an introductory physics or musical acoustics course as a practical lesson in superposition of waves, basic Fourier series and the relationship between some of the ear's subjective perceptions of sound and the physical properties of the waves that cause them.

Simultaneous Detection of Static and Dynamic Signals by a Flexible Sensor Based on 3D Graphene.

PubMed

Xu, Rongqing; Wang, Di; Zhang, Hongchao; Xie, Na; Lu, Shan; Qu, Ke

2017-05-08

A flexible acoustic pressure sensor was developed based on the change in electrical resistance of three-dimensional (3D) graphene change under the acoustic waves action. The sensor was constructed by 3D graphene foam (GF) wrapped in flexible polydimethylsiloxane (PDMS). Tuning forks and human physiological tests indicated that the acoustic pressure sensor can sensitively detect the deformation and the acoustic pressure in real time. The results are of significance to the development of graphene-based applications in the field of health monitoring, in vitro diagnostics, advanced therapies, and transient pressure detection.

Silicon micromachined vibrating gyroscopes

NASA Astrophysics Data System (ADS)

Voss, Ralf

1997-09-01

This work gives an overview of silicon micromachined vibrating gyroscopes. Market perspectives and fields of application are pointed out. The advantage of using silicon micromachining is discussed and estimations of the desired performance, especially for automobiles are given. The general principle of vibrating gyroscopes is explained. Vibrating silicon gyroscopes can be divided into seven classes. for each class the characteristic principle is presented and examples are given. Finally a specific sensor, based on a tuning fork for automotive applications with a sensitivity of 250(mu) V/degrees is described in detail.

Dry demagnetization cryostat for sub-millikelvin helium experiments: Refrigeration and thermometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Todoshchenko, I., E-mail: todo@boojum.hut.fi; Kaikkonen, J.-P.; Hakonen, P. J.

We demonstrate successful “dry” refrigeration of quantum fluids down to T = 0.16 mK by using copper nuclear demagnetization stage that is pre-cooled by a pulse-tube-based dilution refrigerator. This type of refrigeration delivers a flexible and simple sub-mK solution to a variety of needs including experiments with superfluid {sup 3}He. Our central design principle was to eliminate relative vibrations between the high-field magnet and the nuclear refrigeration stage, which resulted in the minimum heat leak of Q = 4.4 nW obtained in field of 35 mT. For thermometry, we employed a quartz tuning fork immersed into liquid {sup 3}He. We show that themore » fork oscillator can be considered as self-calibrating in superfluid {sup 3}He at the crossover point from hydrodynamic into ballistic quasiparticle regime.« less

Tunable Micro- and Nanomechanical Resonators

PubMed Central

Zhang, Wen-Ming; Hu, Kai-Ming; Peng, Zhi-Ke; Meng, Guang

2015-01-01

Advances in micro- and nanofabrication technologies have enabled the development of novel micro- and nanomechanical resonators which have attracted significant attention due to their fascinating physical properties and growing potential applications. In this review, we have presented a brief overview of the resonance behavior and frequency tuning principles by varying either the mass or the stiffness of resonators. The progress in micro- and nanomechanical resonators using the tuning electrode, tuning fork, and suspended channel structures and made of graphene have been reviewed. We have also highlighted some major influencing factors such as large-amplitude effect, surface effect and fluid effect on the performances of resonators. More specifically, we have addressed the effects of axial stress/strain, residual surface stress and adsorption-induced surface stress on the sensing and detection applications and discussed the current challenges. We have significantly focused on the active and passive frequency tuning methods and techniques for micro- and nanomechanical resonator applications. On one hand, we have comprehensively evaluated the advantages and disadvantages of each strategy, including active methods such as electrothermal, electrostatic, piezoelectrical, dielectric, magnetomotive, photothermal, mode-coupling as well as tension-based tuning mechanisms, and passive techniques such as post-fabrication and post-packaging tuning processes. On the other hand, the tuning capability and challenges to integrate reliable and customizable frequency tuning methods have been addressed. We have additionally concluded with a discussion of important future directions for further tunable micro- and nanomechanical resonators. PMID:26501294

[History of the tuning fork. II: Evolution of the classical experiments by Weber, Rinne and Schwabach].

PubMed

Feldmann, H

1997-05-01

Since the 17th centrury it was known that sounds could be perceived via air conduction and bone conduction and that this provided a means of differentiating between hearing disorders located in the middle ear and those located in the acoustic nerve. For a long time to come, however, there was no need for such a differential diagnosis. After the invention of the tuning fork in 1711 this instrument had soon become widely used in music, but it took well over 100 years until it was introduced into physiology and otology. FROM DIRECTIONAL HEARING TO WEBER'S TEST: J. B. Venturi, a physicist in Modena, Italy, in 1802 had shown that the perception of the direction from which a sound is coming is governed by the fact that one ear is hit by the sound more intensely than the other ear. C. T. Tourtual, a physician in Münster, Germany, demonstrated in 1827 that this also holds true for sound conducted via the skull bones. He used a watch as sound source. He found that occlusion of both ear canals would increase the sensation in both ears equally, but that occlusion of only one ear would increase the sensation only in the occluded ear, thus giving the impression that the sound were coming from that side. He was interested in a comparison between vision and audition, and he concluded that with regard to recognizing the direction of a sensory signal vision was superior to audition. In the same year 1827 C. Wheatstone, a physicist in London, investigating the mode of vibration of the tympanic membrane and using a tuning fork found the same phenomena as Tourtual and some more effects. E. H. Weber, an anatomist and physiologist in Leipzig, Germany, described the very same phenomena as Tourtual and Wheatstone once more in 1834. He wanted to prove that airborne sound is perceived by the vestibulum and the semicircular canals, bone conducted sound by the cochlea. None of these investigators was thinking of a clinical use of their findings and made no such suggestion. E. Schmalz, an otologist in Dresden, Germany, in 1845 introduced the tuning fork and the test later named after Weber into otology and explained in great detail all possibilities of a diagnostic evaluation of the test. His grand achievement, however, passed unnoticed at his time. A. Rinne, a physician in Göttingen, Germany. In 1855 described the test which later was named after him, in an elaborate treatise on the physiology of the ear. He wanted to demonstrate that in man and animals living in the air, as opposed to those living in water, the conduction of sound via the bones of the skull is just an unavoidable side effect of sound perception. He mentioned a clinical application of his test only in a footnote and obviously never used it himself in a systematic way. His test was made generally known by Lucae in Berlin only after 1880. The value of Weber's and Rinne's tuning fork tests was much disputed even at the turn of the century and only gradually became generally accepted.

Using Musical Intervals to Demonstrate Superposition of Waves and Fourier Analysis

ERIC Educational Resources Information Center

LoPresto, Michael C.

2013-01-01

What follows is a description of a demonstration of superposition of waves and Fourier analysis using a set of four tuning forks mounted on resonance boxes and oscilloscope software to create, capture and analyze the waveforms and Fourier spectra of musical intervals.

Tuning Fork Oscillators as Downhole Viscometers in Oilfield Applications

NASA Astrophysics Data System (ADS)

Gonzalez, Miguel; Bernero, Greg; Alvarez, Oliverio; Ham, Gregory; Max, Deffenbaugh; Sensors Development Team

2015-03-01

The commerciality of oil wells is greatly influenced by the physical properties of the fluids being produced. A key parameter in determining how producible the hydrocarbons are is their viscosity. Pressure and temperature changes in recovering a downhole sample to the surface can alter viscosity while accurate downhole measurement of this critical property remains a rudimentary effort in the industry. In this presentation we describe the challenges of measuring and quantifying the viscosity of reservoir fluids in situ at downhole conditions, as well as present an overview of some of the different measurement techniques currently used. Additionally, we show our characterization of a piezoelectric tuning fork oscillator used as a viscosity sensor. In an attempt to recreate the environment found in oil wells, its mechanical and electrical properties were studied while the device was immersed in different fluids and, separately, under different conditions of pressure and temperature. This device is a first step toward the development of an inexpensive, integrated, and miniaturized sensing platform for the in situ characterization of reservoir fluids.

A self-strain feedback tuning-fork-shaped ionic polymer metal composite clamping actuator with soft matter elasticity-detecting capability for biomedical applications.

PubMed

Feng, Guo-Hua; Huang, Wei-Lun

2014-12-01

This paper presents a smart tuning-fork-shaped ionic polymer metal composite (IPMC) clamping actuator for biomedical applications. The two fingers of the actuator, which perform the clamping motion, can be electrically controlled through a unique electrode design on the IPMC material. The generated displacement or strain of the fingers can be sensed using an integrated soft strain-gage sensor. The IPMC actuator and associated soft strain gage were fabricated using a micromachining technique. A 13.5×4×2 mm(3) actuator was shaped from Nafion solution and a selectively grown metal electrode formed the active region. The strain gage consisted of patterned copper foil and polyethylene as a substrate. The relationship between the strain gage voltage output and the displacement at the front end of the actuator's fingers was characterized. The equivalent Young's modulus, 13.65 MPa, of the soft-strain-gage-integrated IPMC finger was analyzed. The produced clamping force exhibited a linear increasing rate of 1.07 mN/s, based on a dc driving voltage of 7 V. Using the developed actuator to clamp soft matter and simultaneously acquire its Young's modulus was achieved. This demonstrated the feasibility of the palpation function and the potential use of the actuator in minimally invasive surgery. Copyright © 2014 Elsevier B.V. All rights reserved.

Faculty Development Tug O'War, or Up a Tree with a Tuning Fork

ERIC Educational Resources Information Center

Neff, Charles B.

1976-01-01

A plea is made for a rational and humane effort to reconcile conflicting forces in a genuine movement of faculty development. Faculty members are pulled in two directions: one toward improving performance, and the other toward accountability, retrenchment, or budget cutting. (LBH)

Scanning microwave microscopy applied to semiconducting GaAs structures

NASA Astrophysics Data System (ADS)

Buchter, Arne; Hoffmann, Johannes; Delvallée, Alexandra; Brinciotti, Enrico; Hapiuk, Dimitri; Licitra, Christophe; Louarn, Kevin; Arnoult, Alexandre; Almuneau, Guilhem; Piquemal, François; Zeier, Markus; Kienberger, Ferry

2018-02-01

A calibration algorithm based on one-port vector network analyzer (VNA) calibration for scanning microwave microscopes (SMMs) is presented and used to extract quantitative carrier densities from a semiconducting n-doped GaAs multilayer sample. This robust and versatile algorithm is instrument and frequency independent, as we demonstrate by analyzing experimental data from two different, cantilever- and tuning fork-based, microscope setups operating in a wide frequency range up to 27.5 GHz. To benchmark the SMM results, comparison with secondary ion mass spectrometry is undertaken. Furthermore, we show SMM data on a GaAs p-n junction distinguishing p- and n-doped layers.

Survey of Physical Assessment Course Offerings in American Colleges of Pharmacy.

ERIC Educational Resources Information Center

da Camara, Carlos C.; And Others

1996-01-01

A survey of 55 pharmacy schools found that of those offering a pharmacy doctoral program, three-fourths had a separate course devoted to physical assessment of patients, most offered in the third professional year. Most require students to demonstrate use of stethoscope, sphygmomanometer, ophthalmo-otoscope, tuning fork, reflex hammer. Reasons for…

Teaching about Mechanical Waves and Sound with a Tuning Fork and the Sun

ERIC Educational Resources Information Center

Leccia, Silvio; Colantonio, Arturo; Puddu, Emanuella; Galano, Silvia; Testa, Italo

2015-01-01

Literature in "Physics Education" has shown that students encounter many difficulties in understanding wave propagation. Such difficulties lead to misconceptions also in understanding sound, often used as context to teach wave propagation. To address these issues, we present in this paper a module in which the students are engaged in…

Design of a Compact Tuning Fork-Shaped Notched Ultrawideband Antenna for Wireless Communication Application

PubMed Central

Shakib, M. N.; Moghavvemi, M.; Mahadi, W. N. L.

2014-01-01

A new compact planar notched ultrawideband (UWB) antenna is designed for wireless communication application. The proposed antenna has a compact size of 0.182λ × 0.228λ × 0.018λ where λ is the wavelength of the lowest operating frequency. The antenna is comprised of rectangular radiating patch, ground plane, and an arc-shaped strip in between radiating patch and feed line. By introducing a new Tuning Fork-shaped notch in the radiating plane, a stopband is obtained. The antenna is tested and measured. The measured result indicated that fabricated antenna has achieved a wide bandwidth of 4.33–13.8 GHz (at −10 dB return loss) with a rejection frequency band of 5.28–6.97 GHz (WiMAX, WLAN, and C-band). The effects of the parameters of the antenna are discussed. The experiment results demonstrate that the proposed antenna can well meet the requirement for the UWB communication in spite of its compactness and small size. PMID:24723835

LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Laser microphotoacoustic sensor of ammonia traces in the atmosphere

NASA Astrophysics Data System (ADS)

Serebryakov, D. V.; Morozov, I. V.; Kosterev, A. A.; Letokhov, V. S.

2010-02-01

A microphotoacoustic highly selective sensor of ammonia is built. Main attention is paid to the operation mechanism of the acoustic sensor based on a quartz tuning fork. The optimal dimensions and configuration of the acoustic resonator are determined, which made it possible to increase the sensor sensitivity by two—three times compared to the sensitivity of the existing devices. The detector sensitivity for ammonia was 60ppb (0.05 mg m-3) for the measurement time of 10s and a 25-mW, 1.53-μm laser beam in the acoustic resonator.

A measurement of the hysteresis loop in force-spectroscopy curves using a tuning-fork atomic force microscope

PubMed Central

van Vörden, Dennis; Möller, Rolf

2012-01-01

Summary Measurements of the frequency shift versus distance in noncontact atomic force microscopy (NC-AFM) allow measurements of the force gradient between the oscillating tip and a surface (force-spectroscopy measurements). When nonconservative forces act between the tip apex and the surface the oscillation amplitude is damped. The dissipation is caused by bistabilities in the potential energy surface of the tip–sample system, and the process can be understood as a hysteresis of forces between approach and retraction of the tip. In this paper, we present the direct measurement of the whole hysteresis loop in force-spectroscopy curves at 77 K on the PTCDA/Ag/Si(111) √3 × √3 surface by means of a tuning-fork-based NC-AFM with an oscillation amplitude smaller than the distance range of the hysteresis loop. The hysteresis effect is caused by the making and breaking of a bond between PTCDA molecules on the surface and a PTCDA molecule at the tip. The corresponding energy loss was determined to be 0.57 eV by evaluation of the force–distance curves upon approach and retraction. Furthermore, a second dissipation process was identified through the damping of the oscillation while the molecule on the tip is in contact with the surface. This dissipation process occurs mainly during the retraction of the tip. It reaches a maximum value of about 0.22 eV/cycle. PMID:22496993

Detection of multiple chemicals based on external cavity quantum cascade laser spectroscopy

NASA Astrophysics Data System (ADS)

Sun, Juan; Ding, Junya; Liu, Ningwu; Yang, Guangxiang; Li, Jingsong

2018-02-01

A laser spectroscopy system based on a broadband tunable external cavity quantum cascade laser (ECQCL) and a mini quartz crystal tuning fork (QCTF) detector was developed for standoff detection of volatile organic compounds (VOCs). The self-established spectral analysis model based on multiple algorithms for quantitative and qualitative analysis of VOC components (i.e. ethanol and acetone) was detailedly investigated in both closed cell and open path configurations. A good agreement was obtained between the experimentally observed spectra and the standard reference spectra. For open path detection of VOCs, the sensor system was demonstrated at a distance of 30 m. The preliminary laboratory results show that standoff detection of VOCs at a distance of over 100 m is very promising.

A New Resonance Tube

ERIC Educational Resources Information Center

Bates, Alan

2017-01-01

The measurement of the speed of sound in air with the resonance tube is a popular experiment that often yields accurate results. One approach is to hold a vibrating tuning fork over an air column that is partially immersed in water. The column is raised and lowered in the water until the generated standing wave produces resonance: this occurs at…

Excitation of Standing Waves by an Electric Toothbrush

ERIC Educational Resources Information Center

Cros, Ana; Ferrer-Roca, Chantal

2006-01-01

There are a number of ways of exciting standing waves in ropes and springs using non-commercial vibrators such as loudspeakers, jigsaws, motors, or a simple tuning fork, including the rhythmical shaking of a handheld Slinky. We have come up with a very simple and cheap way of exciting stationary waves in a string, which anyone, particularly…

Quartz tuning fork based sensor for detection of volatile organic compounds: towards breath analysis

NASA Astrophysics Data System (ADS)

Sampson, Abraham; Panchal, Suresh; Phadke, Apoorva; Kashyap, A.; Suman, Jilma; Unnikrishnan, G.; Datar, Suwarna

2018-04-01

Several volatile organic compounds (VOCs) are present in the exhaled human breath whose concentration can vary depending on the physiological changes occurring within a human being. These changes in the concentration or the occurrence of a particular VOC can be used as signature of a particular disease in a person. In the present work, a sensor has been developed to detect VOCs such as 1,4-dimethoxy-2,3-butanediol (BD), and cyclohexanone (CH), acetone, methanol and ethanol. Except for BD and CH, the rest of the VOCs are present in a healthy person in ppm levels. CH and BD have been reported to be present in the exhaled human breath of breast cancer patients in ppm levels and can be used to distinguish between a healthy person and a person with breast cancer. The selectivity of the sensor towards these two compounds in the presence of other VOCs commonly present in human breath like acetone, ethanol and methanol has been studied. The sensor has been developed using modified Quartz Tuning Forks (QTFs) with the intent of developing an array of such sensors identifying different VOCs present in a healthy human’s breath. Two differently modified QTFs have been used to detect 1 ppm of 1,4-dimethoxy-2,3-butanediol and 20 ppm of cyclohexanone. Linear Discriminants Analysis (LDA) has been used to classify seven different VOCs. For this purpose, features extracted from sensor responses -shift in resonant frequency, response time and recovery time of the sensors- have been used as features in the model. Differently modified array of QTFs along with the use of LDA can be a useful pathway towards development of a QTF based sensor array for human breath analysis.

Theory and experimental verifications of the resonator Q and equivalent electrical parameters due to viscoelastic and mounting supports losses.

PubMed

Yong, Yook-Kong; Patel, Mihir S; Tanaka, Masako

2010-08-01

A novel analytical/numerical method for calculating the resonator Q and its equivalent electrical parameters due to viscoelastic, conductivity, and mounting supports losses is presented. The method presented will be quite useful for designing new resonators and reducing the time and costs of prototyping. There was also a necessity for better and more realistic modeling of the resonators because of miniaturization and the rapid advances in the frequency ranges of telecommunication. We present new 3-D finite elements models of quartz resonators with viscoelasticity, conductivity, and mounting support losses. The losses at the mounting supports were modeled by perfectly matched layers (PMLs). A previously published theory for dissipative anisotropic piezoelectric solids was formulated in a weak form for finite element (FE) applications. PMLs were placed at the base of the mounting supports to simulate the energy losses to a semi-infinite base substrate. FE simulations were carried out for free vibrations and forced vibrations of quartz tuning fork and AT-cut resonators. Results for quartz tuning fork and thickness shear AT-cut resonators were presented and compared with experimental data. Results for the resonator Q and the equivalent electrical parameters were compared with their measured values. Good equivalences were found. Results for both low- and high-Q AT-cut quartz resonators compared well with their experimental values. A method for estimating the Q directly from the frequency spectrum obtained for free vibrations was also presented. An important determinant of the quality factor Q of a quartz resonator is the loss of energy from the electrode area to the base via the mountings. The acoustical characteristics of the plate resonator are changed when the plate is mounted onto a base substrate. The base affects the frequency spectra of the plate resonator. A resonator with a high Q may not have a similarly high Q when mounted on a base. Hence, the base is an energy sink and the Q will be affected by the shape and size of this base. A lower-bound Q will be obtained if the base is a semi-infinite base because it will absorb all acoustical energies radiated from the resonator.

Determining Absolute Zero Using a Tuning Fork

ERIC Educational Resources Information Center

Goldader, Jeffrey D.

2008-01-01

The Celsius and Kelvin temperature scales, we tell our students, are related. We explain that a change in temperature of 1 degree C corresponds to a change of 1 Kelvin and that atoms and molecules have zero kinetic energy at zero Kelvin, -273 degrees C. In this paper, we will show how students can derive the relationship between the Celsius and…

Experimenting with End-Correction and the Speed of Sound

ERIC Educational Resources Information Center

LoPresto, Michael C.

2011-01-01

What follows is an alternative to the standard tuning fork and quarter-wave tube speed of sound experiment. Rather than adjusting the water level in a glass or plastic tube to vary the length of an air column, a set of resonance tubes of different lengths is used. The experiment still demonstrates the principles of standing waves in air columns…

Vibration-Induced Errors in MEMS Tuning Fork Gyroscopes with Imbalance.

PubMed

Fang, Xiang; Dong, Linxi; Zhao, Wen-Sheng; Yan, Haixia; Teh, Kwok Siong; Wang, Gaofeng

2018-05-29

This paper discusses the vibration-induced error in non-ideal MEMS tuning fork gyroscopes (TFGs). Ideal TFGs which are thought to be immune to vibrations do not exist, and imbalance between two gyros of TFGs is an inevitable phenomenon. Three types of fabrication imperfections (i.e., stiffness imbalance, mass imbalance, and damping imbalance) are studied, considering different imbalance radios. We focus on the coupling types of two gyros of TFGs in both drive and sense directions, and the vibration sensitivities of four TFG designs with imbalance are simulated and compared. It is found that non-ideal TFGs with two gyros coupled both in drive and sense directions (type CC TFGs) are the most insensitive to vibrations with frequencies close to the TFG operating frequencies. However, sense-axis vibrations with in-phase resonant frequencies of a coupled gyros system result in severe error outputs to TFGs with two gyros coupled in the sense direction, which is mainly attributed to the sense capacitance nonlinearity. With increasing stiffness coupled ratio of the coupled gyros system, the sensitivity to vibrations with operating frequencies is cut down, yet sensitivity to vibrations with in-phase frequencies is amplified.

Investigation on the Mechanical and Electrical Behavior of a Tuning Fork-Shaped Ionic Polymer Metal Composite Actuator with a Continuous Water Supply Mechanism

PubMed Central

Feng, Guo-Hua; Huang, Wei-Lun

2016-01-01

This paper presents an innovative tuning fork-shaped ionic polymer metal composite (IPMC) actuator. With an integrated soft strain gauge and water supply mechanism (WSM), the surface strain of the actuator can be sensed in situ, and providing a continuous water supply maintains the water content inside the IPMC for long-term operation in air. The actuator was fabricated using a micromachining technique and plated with a nickel electrode. The device performance was experimentally characterized and compared with an actuator without a WSM. A large displacement of 1.5 mm was achieved for a 6 mm-long prong with 7-V dc actuation applied for 30 s. The measured current was analyzed using an electrochemical model. The results revealed that the faradaic current plays a crucial role during operation, particularly after 10 s. The measured strain confirms both the bending and axial strain generation during the open-and-close motion of the actuator prongs. Most of the water loss during device operation was due to evaporation rather than hydrolysis. The constructed WSM effectively maintained the water content inside the IPMC for long-term continuous operation. PMID:27023549

Investigation on the Mechanical and Electrical Behavior of a Tuning Fork-Shaped Ionic Polymer Metal Composite Actuator with a Continuous Water Supply Mechanism.

PubMed

Feng, Guo-Hua; Huang, Wei-Lun

2016-03-25

This paper presents an innovative tuning fork-shaped ionic polymer metal composite (IPMC) actuator. With an integrated soft strain gauge and water supply mechanism (WSM), the surface strain of the actuator can be sensed in situ, and providing a continuous water supply maintains the water content inside the IPMC for long-term operation in air. The actuator was fabricated using a micromachining technique and plated with a nickel electrode. The device performance was experimentally characterized and compared with an actuator without a WSM. A large displacement of 1.5 mm was achieved for a 6 mm-long prong with 7-V dc actuation applied for 30 s. The measured current was analyzed using an electrochemical model. The results revealed that the faradaic current plays a crucial role during operation, particularly after 10 s. The measured strain confirms both the bending and axial strain generation during the open-and-close motion of the actuator prongs. Most of the water loss during device operation was due to evaporation rather than hydrolysis. The constructed WSM effectively maintained the water content inside the IPMC for long-term continuous operation.

Objective sound wave amplitude measurement generated by a tuning fork. An analysis of its use as a diagnostic tool in suspected femoral neck fractures.

PubMed

Jawad, Z; Odumala, A; Jones, M

2012-06-01

Hip injuries are becoming a more common problem as the elderly population increases and their management represents a significant proportion of health care costs. Diagnosis of a fracture based on clinical assessment and plain films is not always conclusive and further investigations for such occult fractures, such as magnetic resonance imaging (MRI), are sometimes required which are expensive and may be difficult to access. Disruption to the conduction of a sound wave travelling through a fractured bone is a concept that has been used to diagnose fractures. In our study we used a tuning fork with frequency of 128 Hz to objectively measure the reduction in sound amplitude in fractured and non-fractured hips. We looked at the feasibility of using this test as a diagnostic tool for neck of femur fractures. A total of 20 patients was included in the study, using MRI scan as the standard for comparison of diagnostic findings. Informed consent was obtained from the patients. There was a significant difference in the amplitude reduction of the sound waves when comparing normal to fractured hips. This was 0.9 in normal hips, compared to 0.31 and 0.18 in intra-capsular and extra-capsular fractures, respectively. Our test was 80% accurate at diagnosing neck of femur fractures. In conclusion this test may be used as a diagnostic test or screening tool in the assessment of occult hip fractures. Copyright © 2011 Elsevier Ltd. All rights reserved.

Broadband external cavity quantum cascade laser based sensor for gasoline detection

NASA Astrophysics Data System (ADS)

Ding, Junya; He, Tianbo; Zhou, Sheng; Li, Jinsong

2018-02-01

A new type of tunable diode spectroscopy sensor based on an external cavity quantum cascade laser (ECQCL) and a quartz crystal tuning fork (QCTF) were used for quantitative analysis of volatile organic compounds. In this work, the sensor system had been tested on different gasoline sample analysis. For signal processing, the self-established interpolation algorithm and multiple linear regression algorithm model were used for quantitative analysis of major volatile organic compounds in gasoline samples. The results were very consistent with that of the standard spectra taken from the Pacific Northwest National Laboratory (PNNL) database. In future, The ECQCL sensor will be used for trace explosive, chemical warfare agent, and toxic industrial chemical detection and spectroscopic analysis, etc.

Mid-infrared gas absorption sensor based on a broadband external cavity quantum cascade laser

NASA Astrophysics Data System (ADS)

Sun, Juan; Deng, Hao; Liu, Ningwu; Wang, Hongliang; Yu, Benli; Li, Jingsong

2016-12-01

We developed a laser absorption sensor based on a pulsed, broadband tunable external cavity quantum cascade laser (ECQCL) centered at 1285 cm-1. Unlike traditional infrared spectroscopy system, a quartz crystal tuning fork (QCTF) as a light detector was used for laser signal detection. Fast Fourier transform was applied to extract vibration intensity information of QCTF. The sensor system is successfully tested on nitrous oxide (N2O) spectroscopy measurements and compared with a standard infrared detector. The wide wavelength tunability of ECQCL will allow us to access the fundamental vibrational bands of many chemical agents, which are well-suited for trace explosive, chemical warfare agent, and toxic industrial chemical detection and spectroscopic analysis.

Mid-infrared gas absorption sensor based on a broadband external cavity quantum cascade laser.

PubMed

Sun, Juan; Deng, Hao; Liu, Ningwu; Wang, Hongliang; Yu, Benli; Li, Jingsong

2016-12-01

We developed a laser absorption sensor based on a pulsed, broadband tunable external cavity quantum cascade laser (ECQCL) centered at 1285 cm -1 . Unlike traditional infrared spectroscopy system, a quartz crystal tuning fork (QCTF) as a light detector was used for laser signal detection. Fast Fourier transform was applied to extract vibration intensity information of QCTF. The sensor system is successfully tested on nitrous oxide (N 2 O) spectroscopy measurements and compared with a standard infrared detector. The wide wavelength tunability of ECQCL will allow us to access the fundamental vibrational bands of many chemical agents, which are well-suited for trace explosive, chemical warfare agent, and toxic industrial chemical detection and spectroscopic analysis.

Note: Sound recovery from video using SVD-based information extraction

NASA Astrophysics Data System (ADS)

Zhang, Dashan; Guo, Jie; Lei, Xiujun; Zhu, Chang'an

2016-08-01

This note reports an efficient singular value decomposition (SVD)-based vibration extraction approach that recovers sound information in silent high-speed video. A high-speed camera of which frame rates are in the range of 2 kHz-10 kHz is applied to film the vibrating objects. Sub-images cut from video frames are transformed into column vectors and then reconstructed to a new matrix. The SVD of the new matrix produces orthonormal image bases (OIBs) and image projections onto specific OIB can be recovered as understandable acoustical signals. Standard frequencies of 256 Hz and 512 Hz tuning forks are extracted offline from their vibrating surfaces and a 3.35 s speech signal is recovered online from a piece of paper that is stimulated by sound waves within 1 min.

A Quasiparticle Detector for Imaging Quantum Turbulence in Superfluid He-B

NASA Astrophysics Data System (ADS)

Ahlstrom, S. L.; Bradley, D. I.; Fisher, S. N.; Guénault, A. M.; Guise, E. A.; Haley, R. P.; Holt, S.; Kolosov, O.; McClintock, P. V. E.; Pickett, G. R.; Poole, M.; Schanen, R.; Tsepelin, V.; Woods, A. J.

2014-06-01

We describe the development of a two-dimensional quasiparticle detector for use in visualising quantum turbulence in superfluid He-B at ultra-low temperatures. The detector consists of a matrix of pixels, each a 1 mm diameter hole in a copper block containing a miniature quartz tuning fork. The damping on each fork provides a measure of the local quasiparticle flux. The detector is illuminated by a beam of ballistic quasiparticles generated from a nearby black-body radiator. A comparison of the damping on the different forks provides a measure of the cross-sectional profile of the beam. Further, we generate a tangle of vortices (quantum turbulence) in the path of the beam using a vibrating wire resonator. The vortices cast a shadow onto the face of the detector due to the Andreev reflection of quasiparticles in the beam. This allows us to image the vortices and to investigate their dynamics. Here we give details of the design and construction of the detector and show some preliminary results for one row of pixels which demonstrates its successful application to measuring quasiparticle beams and quantum turbulence.

Simple Excitation of Standing Waves in Rubber Bands and Membranes

NASA Astrophysics Data System (ADS)

Cortel, Adolf

2004-04-01

Many methods to excite standing waves in strings, plates, membranes, rods, tubes, and soap bubbles have been described. Usually a loudspeaker or a vibrating reed is driven by the amplified output of an audio oscillator. A novel and simple method consists of using a tuning fork or a singing rod to excite transversal standing waves in stretched rubber membranes sprinkled with fine sand.

Flexible and wearable 3D graphene sensor with 141 KHz frequency signal response capability

NASA Astrophysics Data System (ADS)

Xu, R.; Zhang, H.; Cai, Y.; Ruan, J.; Qu, K.; Liu, E.; Ni, X.; Lu, M.; Dong, X.

2017-09-01

We developed a flexible force sensor consisting of 3D graphene foam (GF) encapsulated in flexible polydimethylsiloxane (PDMS). Because the 3D GF/PDMS sensor is based on the transformation of an electronic band structure aroused by static mechanical strain or KHz vibration, it can detect frequency signals by both tuning fork tests and piezoelectric ceramic transducer tests, which showed a clear linear response from audio frequencies, including frequencies up to 141 KHz in the ultrasound range. Because of their excellent response with a wide bandwidth, the 3D GF/PDMS sensors are attractive for interactive wearable devices or artificial prosthetics capable of perceiving seismic waves, ultrasonic waves, shock waves, and transient pressures.

Mid-Infrared Trace Gas Sensor Technology Based on Intracavity Quartz-Enhanced Photoacoustic Spectroscopy.

PubMed

Wojtas, Jacek; Gluszek, Aleksander; Hudzikowski, Arkadiusz; Tittel, Frank K

2017-03-04

The application of compact inexpensive trace gas sensor technology to a mid-infrared nitric oxide (NO) detectoion using intracavity quartz-enhanced photoacoustic spectroscopy (I-QEPAS) is reported. A minimum detection limit of 4.8 ppbv within a 30 ms integration time was demonstrated by using a room-temperature, continuous-wave, distributed-feedback quantum cascade laser (QCL) emitting at 5.263 µm (1900.08 cm -1 ) and a new compact design of a high-finesse bow-tie optical cavity with an integrated resonant quartz tuning fork (QTF). The optimum configuration of the bow-tie cavity was simulated using custom software. Measurements were performed with a wavelength modulation scheme (WM) using a 2f detection procedure.

QEPAS nitric oxide sensor based on a mid-infrared fiber-coupled quantum cascade laser

NASA Astrophysics Data System (ADS)

Ren, Wei; Shi, Chao; Wang, Zhen; Yao, Chenyu

2017-04-01

We report a quartz-enhanced photoacoustic sensor (QEPAS) for nitric oxide (NO) detection using a mid-infrared fibercoupled quantum cascade laser (QCL) near 5.2 μm. The QCL radiation was coupled into an InF3 fiber (100 μm core diameter) for light delivery to the quartz tuning fork, a tiny piezoelectric element converting the acoustic wave induced mechanical vibration to the gas-absorption associated electrical signal. This mid-infrared fiber can achieve nearly single-mode light delivery for the target wavelength. The off-beam configuration was adopted for the fiber-coupled detection considering its simpler installation, optical alignment and comparative sensitivity to the traditional on-beam setup.

Vibration modes interference in the MEMS resonant pressure sensor

NASA Astrophysics Data System (ADS)

Zhang, Fangfang; Li, Anlin; Bu, Zhenxiang; Wang, Lingyun; Sun, Daoheng; Du, Xiaohui; Gu, Dandan

2017-11-01

A new type of coupled balanced-mass double-ended tuning fork resonator (CBDETF) pressure sensor is fabricated and tested. However, the low accuracy of the CBDETF pressure sensor is not satisfied to us. Based on systematic analysis and tests, the coupling effect between the operational mode and interference mode is considered to be the main cause for the sensor in accuracy. To solve this problem, the stiffness of the serpentine beams is increased to pull up the resonant frequency of the interfering mode and make it separate far from the operational mode. Finally, the accuracy of the CBDETF pressure sensor is improved from + /-0.5% to less than + /-0.03% of the Full Scale (F.S.).

MicroMegascope.

PubMed

Canale, L; Laborieux, A; Mogane, A Aroul; Jubin, L; Comtet, J; Lainé, A; Bocquet, L; Siria, A; Niguès, A

2018-08-31

Atomic force microscopy (AFM) allows us to reconstruct the topography of surfaces with resolution in the nanometer range. The exceptional resolution attainable with the AFM makes this instrument a key tool in nanoscience and technology. The core of a standard AFM set-up relies on the detection of the change of the mechanical motion of a micro-oscillator when approaching the sample to image. This is despite the fact that AFM is nowadays a very common instrument for both fundamental and applied research. The fabrication of the micrometric scale mechanical oscillator is still a very complicated and expensive task requiring dedicated platforms. Being able to perform AFM with a macroscopic oscillator would make the instrument more versatile and accessible for an even larger spectrum of applications and audience. Here, we present atomic force imaging with a centimetric oscillator, an aluminum tuning fork of centimeter size as a sensor on which an accelerometer is glued on one prong to measure the oscillations. We show that it is possible to perform topographic images of nanometric resolution with a gram tuning fork. In addition to the stunning sensitivity, we show the high versatility of such an oscillator by imaging both in air and liquid. The set-up proposed here can be extended to numerous experiments where the probe has to be heavy and/or very complex, and so too the environment.

Research on the Sensing Performance of the Tuning Fork-Probe as a Micro Interaction Sensor

PubMed Central

Gao, Fengli; Li, Xide

2015-01-01

The shear force position system has been widely used in scanning near-field optical microscopy (SNOM) and recently extended into the force sensing area. The dynamic properties of a tuning fork (TF), the core component of this system, directly determine the sensing performance of the shear positioning system. Here, we combine experimental results and finite element method (FEM) analysis to investigate the dynamic behavior of the TF probe assembled structure (TF-probe). Results from experiments under varying atmospheric pressures illustrate that the oscillation amplitude of the TF-probe is linearly related to the quality factor, suggesting that decreasing the pressure will dramatically increase the quality factor. The results from FEM analysis reveal the influences of various parameters on the resonant performance of the TF-probe. We compared numerical results of the frequency spectrum with the experimental data collected by our recently developed laser Doppler vibrometer system. Then, we investigated the parameters affecting spatial resolution of the SNOM and the dynamic response of the TF-probe under longitudinal and transverse interactions. It is found that the interactions in transverse direction is much more sensitive than that in the longitudinal direction. Finally, the TF-probe was used to measure the friction coefficient of a silica–silica interface. PMID:26404310

Measuring the speed of sound in air using smartphone applications

NASA Astrophysics Data System (ADS)

Yavuz, A.

2015-05-01

This study presents a revised version of an old experiment available in many textbooks for measuring the speed of sound in air. A signal-generator application in a smartphone is used to produce the desired sound frequency. Nodes of sound waves in a glass pipe, of which one end is immersed in water, are more easily detected, so results can be obtained more quickly than from traditional acoustic experiments using tuning forks.

Calibration of Speed Enforcement Down-The-Road Radars

PubMed Central

Jendzurski, John; Paulter, Nicholas G.

2009-01-01

We examine the measurement uncertainty associated with different methods of calibrating the ubiquitous down-the-road (DTR) radar used in speed enforcement. These calibration methods include the use of audio frequency sources, tuning forks, a fifth wheel attached to the rear of the vehicle with the radar unit, and the speedometer of the vehicle. We also provide an analysis showing the effect of calibration uncertainty on DTR-radar speed measurement uncertainty. PMID:27504217

Mid-Infrared Trace Gas Sensor Technology Based on Intracavity Quartz-Enhanced Photoacoustic Spectroscopy

PubMed Central

Wojtas, Jacek; Gluszek, Aleksander; Hudzikowski, Arkadiusz; Tittel, Frank K.

2017-01-01

The application of compact inexpensive trace gas sensor technology to a mid-infrared nitric oxide (NO) detectoion using intracavity quartz-enhanced photoacoustic spectroscopy (I-QEPAS) is reported. A minimum detection limit of 4.8 ppbv within a 30 ms integration time was demonstrated by using a room-temperature, continuous-wave, distributed-feedback quantum cascade laser (QCL) emitting at 5.263 µm (1900.08 cm−1) and a new compact design of a high-finesse bow-tie optical cavity with an integrated resonant quartz tuning fork (QTF). The optimum configuration of the bow-tie cavity was simulated using custom software. Measurements were performed with a wavelength modulation scheme (WM) using a 2f detection procedure. PMID:28273836

Recent advances in quartz enhanced photoacoustic sensing

NASA Astrophysics Data System (ADS)

Patimisco, Pietro; Sampaolo, Angelo; Dong, Lei; Tittel, Frank K.; Spagnolo, Vincenzo

2018-03-01

This review aims to discuss the latest advancements in quartz-enhanced photoacoustic spectroscopy (QEPAS) based trace-gas sensing. Starting from the QEPAS basic physical principles, the most used QEPAS configurations will be described. This is followed by a detailed theoretical analysis and experimental study regarding the influence of quartz tuning forks (QTFs) geometry on their optoacoustic transducer performance. Furthermore, an overview of the latest developments in QEPAS trace-gas sensor technology employing custom QTFs will be reported. Results obtained by exploiting novel micro-resonator configurations, capable of increasing the QEPAS signal-to-noise ratio by more than two orders of magnitude and the utilization of QTF overtone flexural modes for QEPAS based sensing will be presented. A comparison of the QEPAS performance of different spectrophone configurations is reported based upon signal-to-noise ratio. Finally, a novel QEPAS approach allowing simultaneous dual-gas detection will be described.

Nanoscale capillary freezing of ionic liquids confined between metallic interfaces and the role of electronic screening

PubMed Central

Comtet, Jean; Niguès, Antoine; Kaiser, Vojtech; Coasne, Benoit; Bocquet, Lydéric; Siria, Alessandro

2017-01-01

Room temperature Ionic liquids (RTIL) are new materials with fundamental importance for energy storage and active lubrication. They are unsual liquids, which challenge the classical frameworks of electrolytes, whose behavior at electrified interfaces remains elusive with exotic responses relevant to their electrochemical activity. By means of tuning fork based AFM nanorheological measurements, we explore here the properties of confined RTIL, unveiling a dramatic change of the RTIL towards a solid-like phase below a threshold thickness, pointing to capillary freezing in confinement. This threshold is related to the metallic nature of the confining materials, with more metallic surfaces facilitating freezing. This is interpreted in terms of the shift of freezing transition, taking into account the influence of the electronic screening on RTIL wetting of the confining surfaces. Our findings provide fresh views on the properties of confined RTIL with implications for their properties inside nanoporous metallic structures and suggests applications to tune nanoscale lubrication with phase-changing RTIL, by varying the nature and patterning of the substrate, and application of active polarisation. PMID:28346432

Nanoscale capillary freezing of ionic liquids confined between metallic interfaces and the role of electronic screening.

PubMed

Comtet, Jean; Niguès, Antoine; Kaiser, Vojtech; Coasne, Benoit; Bocquet, Lydéric; Siria, Alessandro

2017-06-01

Room-temperature ionic liquids (RTILs) are new materials with fundamental importance for energy storage and active lubrication. They are unusual liquids, which challenge the classical frameworks of electrolytes, whose behaviour at electrified interfaces remains elusive, with exotic responses relevant to their electrochemical activity. Using tuning-fork-based atomic force microscope nanorheological measurements, we explore here the properties of confined RTILs, unveiling a dramatic change of the RTIL towards a solid-like phase below a threshold thickness, pointing to capillary freezing in confinement. This threshold is related to the metallic nature of the confining materials, with more metallic surfaces facilitating freezing. This behaviour is interpreted in terms of the shift of the freezing transition, taking into account the influence of the electronic screening on RTIL wetting of the confining surfaces. Our findings provide fresh views on the properties of confined RTIL with implications for their properties inside nanoporous metallic structures, and suggests applications to tune nanoscale lubrication with phase-changing RTILs, by varying the nature and patterning of the substrate, and application of active polarization.

Nanoscale capillary freezing of ionic liquids confined between metallic interfaces and the role of electronic screening

NASA Astrophysics Data System (ADS)

Comtet, Jean; Niguès, Antoine; Kaiser, Vojtech; Coasne, Benoit; Bocquet, Lydéric; Siria, Alessandro

2017-06-01

Room-temperature ionic liquids (RTILs) are new materials with fundamental importance for energy storage and active lubrication. They are unusual liquids, which challenge the classical frameworks of electrolytes, whose behaviour at electrified interfaces remains elusive, with exotic responses relevant to their electrochemical activity. Using tuning-fork-based atomic force microscope nanorheological measurements, we explore here the properties of confined RTILs, unveiling a dramatic change of the RTIL towards a solid-like phase below a threshold thickness, pointing to capillary freezing in confinement. This threshold is related to the metallic nature of the confining materials, with more metallic surfaces facilitating freezing. This behaviour is interpreted in terms of the shift of the freezing transition, taking into account the influence of the electronic screening on RTIL wetting of the confining surfaces. Our findings provide fresh views on the properties of confined RTIL with implications for their properties inside nanoporous metallic structures, and suggests applications to tune nanoscale lubrication with phase-changing RTILs, by varying the nature and patterning of the substrate, and application of active polarization.

Study of the renal segmental arterial anatomy with contrast-enhanced multi-detector computed tomography.

PubMed

Rocco, Francesco; Cozzi, Luigi Alberto; Cozzi, Gabriele

2015-07-01

To use triphasic multi-detector computed tomography (MDCT) to study the renal segmental arterial anatomy and its relationship with the urinary tract to plan nephron-sparing surgery (NSS). One hundred and fifty nine patients underwent abdominal contrast-enhanced MDCT. We evaluated renal arteries and parenchymal vasculature. In 61 patients, the arteries and the urinary tract were represented simultaneously. 86.60% presented a single renal artery; 13.4%, multiple arteries. All single renal arteries divided into anterior and posterior branch before the hilum. The anterior artery branched into a superior, middle, and inferior branch. In 43.14%, the inferior artery arose before the others; in 45.75%, the superior artery arose before the others; in 9.80%, the branches shared a common trunk. In 26.80%, the posterior artery supplies the entire posterior surface; in 73.20%, it ends along the inferior calyx. In 96.73%, the upper pole was vascularized by the anterior superior branch and the posterior artery: the "tuning fork". MDCT showed four vascular segments in 96.73% and five in 3.27%. MDCT showed two avascular areas: the first along the projection of the inferior calyx on the posterior aspect, the second between the branches of the "tuning fork". The arterial phase provides the arterial tree representation; the delayed phase shows arteries and urinary tract simultaneously. MDCT provides a useful representation of the renal anatomy prior to intervascular-intrarenal NSS.

Utility of quantitative sensory testing and screening tools in identifying HIV-associated peripheral neuropathy in Western Kenya: pilot testing.

PubMed

Cettomai, Deanna; Kwasa, Judith; Kendi, Caroline; Birbeck, Gretchen L; Price, Richard W; Bukusi, Elizabeth A; Cohen, Craig R; Meyer, Ana-Claire

2010-12-08

Neuropathy is the most common neurologic complication of HIV but is widely under-diagnosed in resource-constrained settings. We aimed to identify tools that accurately distinguish individuals with moderate/severe peripheral neuropathy and can be administered by non-physician healthcare workers (HCW) in resource-constrained settings. We enrolled a convenience sample of 30 HIV-infected outpatients from a Kenyan HIV-care clinic. A HCW administered the Neuropathy Severity Score (NSS), Single Question Neuropathy Screen (Single-QNS), Subjective Peripheral Neuropathy Screen (Subjective-PNS), and Brief Peripheral Neuropathy Screen (Brief-PNS). Monofilament, graduated tuning fork, and two-point discrimination examinations were performed. Tools were validated against a neurologist's clinical assessment of moderate/severe neuropathy. The sample was 57% male, mean age 38.6 years, and mean CD4 count 324 cells/µL. Neurologist's assessment identified 20% (6/30) with moderate/severe neuropathy. Diagnostic utilities for moderate/severe neuropathy were: Single-QNS--83% sensitivity, 71% specificity; Subjective-PNS-total--83% sensitivity, 83% specificity; Subjective-PNS-max and NSS--67% sensitivity, 92% specificity; Brief-PNS--0% sensitivity, 92% specificity; monofilament--100% sensitivity, 88% specificity; graduated tuning fork--83% sensitivity, 88% specificity; two-point discrimination--75% sensitivity, 58% specificity. Pilot testing suggests Single-QNS, Subjective-PNS, and monofilament examination accurately identify HIV-infected patients with moderate/severe neuropathy and may be useful diagnostic tools in resource-constrained settings.

Environmental Assessment Deicer Recovery at Grand Forks AFB, North Dakota

DTIC Science & Technology

2004-12-15

Air Force Base (AFB), North Dakota. Contacts: 319 CES/CEVA 525 Tuskegee Airmen Boulevard (Blvd) Grand Forks AFB, ND...ACRONYMS, ABBREVIATIONS, AND TERMS AAM Annual Arithmetic Mean ACM Asbestos Containing Material AFB Air Force Base AFI Air Force Instruction AICUZ...meter 10 GFAFB Grand Forks Air Force Base HAP Hazardous Air Pollutants hr Hour H2S Hydrogen Sulfide IRP Installation Restoration

Analysis of Lubricant Films in Bearings Under Incipient Failure Conditions.

DTIC Science & Technology

1981-01-01

AFOSUR. 8 2 -34 0 1 ACEjSN NO. lEN’ CATALOG NUMBERFO"R8 0-0010 4 4. TITLE (and Subtitio) S. TYPE OFf REPORT a PERIOD COVERED "Analysis of Lubricant...spectroscopy of the lubricant in operating heavily loaded bearings under so-called elasto- hydrodynamic lubricating conditions. In this type of...Chopper and Blackbody Reference Both interferometers are equipped with choppers of the tuning fork type shown in Fig. 6. The tines are located in front of

Preliminary design and development of a reflectance spectrometer instrument

NASA Technical Reports Server (NTRS)

Mccord, T. B.

1979-01-01

An improved design for the reflectance spectrometer is described to be used on various terrestrial body missions. These improvements were made on the original Lunar Polar Orbiter design. These include a larger entrance mirror, rectangular aperture, multiple optical beams, spatial resolution, and a bandwidth extension to 5 microns. In addition, detailed electronic designs were produced for a charge amplifier and an amplifier/demodulator/integrator. Design of a microprocessor driven test system was begun. Laboratory tests were performed on a tuning fork chopper.

Family Traits of Galaxies: From the Tuning Fork to a Physical Classification in a Multi-Wavelength Context

NASA Astrophysics Data System (ADS)

Rampazzo, Roberto; D'Onofrio, Mauro; Zaggia, Simone; Elmegreen, Debra M.; Laurikainen, Eija; Duc, Pierre-Alain; Gallart, Carme; Fraix-Burnet, Didier

At the time of the Great Debate nebulæ where recognized to have different morphologies and first classifications, sometimes only descriptive, have been attempted. A review of these early classification systems are well documented by the Allan Sandage's review in 2005 (Sandage 2005). This review emphasized the debt, in term of continuity of forms of spiral galaxies, due by the Hubble's classification scheme to the Reynold's systems proposed in 1920 (Reynolds, 1920).

Inter-Fork Strand Annealing causes genomic deletions during the termination of DNA replication.

PubMed

Morrow, Carl A; Nguyen, Michael O; Fower, Andrew; Wong, Io Nam; Osman, Fekret; Bryer, Claire; Whitby, Matthew C

2017-06-06

Problems that arise during DNA replication can drive genomic alterations that are instrumental in the development of cancers and many human genetic disorders. Replication fork barriers are a commonly encountered problem, which can cause fork collapse and act as hotspots for replication termination. Collapsed forks can be rescued by homologous recombination, which restarts replication. However, replication restart is relatively slow and, therefore, replication termination may frequently occur by an active fork converging on a collapsed fork. We find that this type of non-canonical fork convergence in fission yeast is prone to trigger deletions between repetitive DNA sequences via a mechanism we call Inter-Fork Strand Annealing (IFSA) that depends on the recombination proteins Rad52, Exo1 and Mus81, and is countered by the FANCM-related DNA helicase Fml1. Based on our findings, we propose that IFSA is a potential threat to genomic stability in eukaryotes.

RTSPM: real-time Linux control software for scanning probe microscopy.

PubMed

Chandrasekhar, V; Mehta, M M

2013-01-01

Real time computer control is an essential feature of scanning probe microscopes, which have become important tools for the characterization and investigation of nanometer scale samples. Most commercial (and some open-source) scanning probe data acquisition software uses digital signal processors to handle the real time data processing and control, which adds to the expense and complexity of the control software. We describe here scan control software that uses a single computer and a data acquisition card to acquire scan data. The computer runs an open-source real time Linux kernel, which permits fast acquisition and control while maintaining a responsive graphical user interface. Images from a simulated tuning-fork based microscope as well as a standard topographical sample are also presented, showing some of the capabilities of the software.

High-Power DFB Diode Laser-Based CO-QEPAS Sensor: Optimization and Performance.

PubMed

Ma, Yufei; Tong, Yao; He, Ying; Yu, Xin; Tittel, Frank K

2018-01-04

A highly sensitive carbon monoxide (CO) trace gas sensor based on quartz-enhanced photoacoustic spectroscopy (QEPAS) was demonstrated. A high-power distributed feedback (DFB), continuous wave (CW) 2.33 μm diode laser with an 8.8 mW output power was used as the QEPAS excitation source. By optimizing the modulation depth and adding an optimum micro-resonator, compared to a bare quartz tuning fork (QTF), a 10-fold enhancement of the CO-QEPAS signal amplitude was achieved. When water vapor acting as a vibrational transfer catalyst was added to the target gas, the signal was further increased by a factor of ~7. A minimum detection limit (MDL) of 11.2 ppm and a calculated normalized noise equivalent absorption (NNEA) coefficient of 1.8 × 10 -5 cm -1 W/√Hz were obtained for the reported CO-QEPAS sensor.

High-Power DFB Diode Laser-Based CO-QEPAS Sensor: Optimization and Performance

PubMed Central

Ma, Yufei; Tong, Yao; He, Ying; Yu, Xin

2018-01-01

A highly sensitive carbon monoxide (CO) trace gas sensor based on quartz-enhanced photoacoustic spectroscopy (QEPAS) was demonstrated. A high-power distributed feedback (DFB), continuous wave (CW) 2.33 μm diode laser with an 8.8 mW output power was used as the QEPAS excitation source. By optimizing the modulation depth and adding an optimum micro-resonator, compared to a bare quartz tuning fork (QTF), a 10-fold enhancement of the CO-QEPAS signal amplitude was achieved. When water vapor acting as a vibrational transfer catalyst was added to the target gas, the signal was further increased by a factor of ~7. A minimum detection limit (MDL) of 11.2 ppm and a calculated normalized noise equivalent absorption (NNEA) coefficient of 1.8 × 10−5 cm−1W/√Hz were obtained for the reported CO-QEPAS sensor. PMID:29300310

Part-per-trillion level SF6 detection using a quartz enhanced photoacoustic spectroscopy-based sensor with single-mode fiber-coupled quantum cascade laser excitation.

PubMed

Spagnolo, Vincenzo; Patimisco, Pietro; Borri, Simone; Scamarcio, Gaetano; Bernacki, Bruce E; Kriesel, Jason

2012-11-01

A sensitive spectroscopic sensor based on a hollow-core fiber-coupled quantum cascade laser (QCL) emitting at 10.54 μm and quartz enhanced photoacoustic spectroscopy (QEPAS) technique is reported. The design and realization of mid-IR fiber and coupler optics has ensured single-mode QCL beam delivery to the QEPAS sensor. The collimation optics was designed to produce a laser beam of significantly reduced beam size and waist so as to prevent illumination of the quartz tuning fork and microresonator tubes. SF(6) was selected as the target gas. A minimum detection sensitivity of 50 parts per trillion in 1 s was achieved with a QCL power of 18 mW, corresponding to a normalized noise-equivalent absorption of 2.7×10(-10) W·cm(-1)/Hz(1/2).

Part-Per-Trillion Level SF6 Detection Using a Quartz Enhanced Photoacoustic Spectroscopy-Based Sensor with Single-Mode Fiber-Coupled Quantum Cascade Laser Excitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spagnolo, V.; Patimisco, P.; Borri, Simone

2012-10-23

A sensitive spectroscopic sensor based on a hollow-core fiber-coupled quantum cascade laser (QCL) emitting at 10.54 µm and quartz enhanced photoacoustic spectroscopy (QEPAS) technique is reported. The design and realization of mid-infrared fiber and coupler optics has ensured single-mode QCL beam delivery to the QEPAS sensor . The collimation optics was designed to produce a laser beam of significantly reduced beam size and waist so as to prevent illumination of the quartz tuning fork and micro-resonator tubes. SF6 was selected as the target gas. A minimum detection sensitivity of 50 parts per trillion in 1 s was achieved with amore » QCL power of 18 mW, corresponding to a normalized noise-equivalent absorption of 2.7x10-10 W•cm-1/Hz1/2.« less

A three-fingered, touch-sensitive, metrological micro-robotic assembly tool

NASA Astrophysics Data System (ADS)

Torralba, Marta; Hastings, D. J.; Thousand, Jeffery D.; Nowakowski, Bartosz K.; Smith, Stuart T.

2015-12-01

This article describes a metrological, robotic hand to manipulate and measure micrometer size objects. The presented work demonstrates not only assembly operations, but also positioning control and metrology capability. Sample motion is achieved by a commercial positioning stage, which provides XYZ-displacements for assembly of components. A designed and manufactured gripper tool that incorporates 21 degrees-of-freedom for independent alignment of actuators, sensors, and the three fingers of this hand is presented. These fingers can be opened and closed by piezoelectric actuators through levered flexures providing an 80 μm displacement range measured with calibrated opto-interrupter based, knife-edge sensors. The operational ends of the fingers comprise of a quartz tuning fork with a 7 μm diameter 3.2 mm long carbon fiber extending from the end of one tuning fork tine. Finger-tip force-sensing is achieved by the monitoring of individual finger resonances typically at around 32 kHz. Experimental results included are focused on probe performance analysis. Pick and place operation using the three fingers is demonstrated with all fingers being continuously oscillated, a capability not possible with the previous single or two finger tweezer type designs. By monitoring electrical feedback during pick and place operations, changes in the response of the three probes demonstrate the ability to identify both grab and release operations. Component metrology has been assessed by contacting different micro-spheres of diameters 50(±7.5) μm, 135(±20) μm, and 140(±20) μm. These were measured by the micro robot to have diameters of 67, 133, and 126 μm respectively with corresponding deviations of 4.2, 4.9, and 4.3 μm. This deviation in the measured results was primarily due to the manual, joystick-based, contacting of the fingers, difficulties associated with centering the components to the axis of the hand, and lower contact sensitivity for the smallest sphere. Finally, assemblies of spheres onto the edge of a razor blade plus assembly of spherical contact probes for micro-meter scale coordinate measurement applications are presented.

Force regulated dynamics of RPA on a DNA fork

PubMed Central

Kemmerich, Felix E.; Daldrop, Peter; Pinto, Cosimo; Levikova, Maryna; Cejka, Petr; Seidel, Ralf

2016-01-01

Replication protein A (RPA) is a single-stranded DNA binding protein, involved in most aspects of eukaryotic DNA metabolism. Here, we study the behavior of RPA on a DNA substrate that mimics a replication fork. Using magnetic tweezers we show that both yeast and human RPA can open forked DNA when sufficient external tension is applied. In contrast, at low force, RPA becomes rapidly displaced by the rehybridization of the DNA fork. This process appears to be governed by the binding or the release of an RPA microdomain (toehold) of only few base-pairs length. This gives rise to an extremely rapid exchange dynamics of RPA at the fork. Fork rezipping rates reach up to hundreds of base-pairs per second, being orders of magnitude faster than RPA dissociation from ssDNA alone. Additionally, we show that RPA undergoes diffusive motion on ssDNA, such that it can be pushed over long distances by a rezipping fork. Generally the behavior of both human and yeast RPA homologs is very similar. However, in contrast to yeast RPA, the dissociation of human RPA from ssDNA is greatly reduced at low Mg2+ concentrations, such that human RPA can melt DNA in absence of force. PMID:27016742

Development of Rotational Accelerometers Final Report CRADA No. TSB-2008-99

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hunter, S.; Crosson, R.

One of the difficulties in fabricating an inexpensive angular rate or rotation sensor is producing a device that is insensitive to acceleration, including the constant acceleration of gravity. The majority of rate sensors are either tuning fork type devices sensing a relatively weak force (i.e., Coriolis effect) and thus not very sensitive, or gyroscopes (either rotating or fiber optic based) that are large, consume lots of power and are expensive. This project was a collaborative effort between LLNL and The Fredericks Company to develop a rotational sensor as a standardized, commercial product. The Fredericks Company possessed expertise and capabilities inmore » the technical aspects of manufacturing this type of sensor, and they were interested in collaborating with LLNL to manufacture the rotational rate sensors as a commercial product.« less

Force regulated dynamics of RPA on a DNA fork.

PubMed

Kemmerich, Felix E; Daldrop, Peter; Pinto, Cosimo; Levikova, Maryna; Cejka, Petr; Seidel, Ralf

2016-07-08

Replication protein A (RPA) is a single-stranded DNA binding protein, involved in most aspects of eukaryotic DNA metabolism. Here, we study the behavior of RPA on a DNA substrate that mimics a replication fork. Using magnetic tweezers we show that both yeast and human RPA can open forked DNA when sufficient external tension is applied. In contrast, at low force, RPA becomes rapidly displaced by the rehybridization of the DNA fork. This process appears to be governed by the binding or the release of an RPA microdomain (toehold) of only few base-pairs length. This gives rise to an extremely rapid exchange dynamics of RPA at the fork. Fork rezipping rates reach up to hundreds of base-pairs per second, being orders of magnitude faster than RPA dissociation from ssDNA alone. Additionally, we show that RPA undergoes diffusive motion on ssDNA, such that it can be pushed over long distances by a rezipping fork. Generally the behavior of both human and yeast RPA homologs is very similar. However, in contrast to yeast RPA, the dissociation of human RPA from ssDNA is greatly reduced at low Mg(2+) concentrations, such that human RPA can melt DNA in absence of force. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Accurate aging of juvenile salmonids using fork lengths

USGS Publications Warehouse

Sethi, Suresh; Gerken, Jonathon; Ashline, Joshua

2017-01-01

Juvenile salmon life history strategies, survival, and habitat interactions may vary by age cohort. However, aging individual juvenile fish using scale reading is time consuming and can be error prone. Fork length data are routinely measured while sampling juvenile salmonids. We explore the performance of aging juvenile fish based solely on fork length data, using finite Gaussian mixture models to describe multimodal size distributions and estimate optimal age-discriminating length thresholds. Fork length-based ages are compared against a validation set of juvenile coho salmon, Oncorynchus kisutch, aged by scales. Results for juvenile coho salmon indicate greater than 95% accuracy can be achieved by aging fish using length thresholds estimated from mixture models. Highest accuracy is achieved when aged fish are compared to length thresholds generated from samples from the same drainage, time of year, and habitat type (lentic versus lotic), although relatively high aging accuracy can still be achieved when thresholds are extrapolated to fish from populations in different years or drainages. Fork length-based aging thresholds are applicable for taxa for which multiple age cohorts coexist sympatrically. Where applicable, the method of aging individual fish is relatively quick to implement and can avoid ager interpretation bias common in scale-based aging.

High quality-factor quartz tuning fork glass probe used in tapping mode atomic force microscopy for surface profile measurement

NASA Astrophysics Data System (ADS)

Chen, Yuan-Liu; Xu, Yanhao; Shimizu, Yuki; Matsukuma, Hiraku; Gao, Wei

2018-06-01

This paper presents a high quality-factor (Q-factor) quartz tuning fork (QTF) with a glass probe attached, used in frequency modulation tapping mode atomic force microscopy (AFM) for the surface profile metrology of micro and nanostructures. Unlike conventionally used QTFs, which have tungsten or platinum probes for tapping mode AFM, and suffer from a low Q-factor influenced by the relatively large mass of the probe, the glass probe, which has a lower density, increases the Q-factor of the QTF probe unit allowing it to obtain better measurement sensitivity. In addition, the process of attaching the probe to the QTF with epoxy resin, which is necessary for tapping mode AFM, is also optimized to further improve the Q-factor of the QTF glass probe. The Q-factor of the optimized QTF glass probe unit is demonstrated to be very close to that of a bare QTF without a probe attached. To verify the effectiveness and the advantages of the optimized QTF glass probe unit, the probe unit is integrated into a home-built tapping mode AFM for conducting surface profile measurements of micro and nanostructures. A blazed grating with fine tool marks of 100 nm, a microprism sheet with a vertical amplitude of 25 µm and a Fresnel lens with a steep slope of 90 degrees are used as measurement specimens. From the measurement results, it is demonstrated that the optimized QTF glass probe unit can achieve higher sensitivity as well as better stability than conventional probes in the measurement of micro and nanostructures.

An initial evaluation of a proof-of-concept 128-Hz electronic tuning fork in the detection of peripheral neuropathy.

PubMed

O'Brien, Todd; Karem, Joseph

2014-03-01

Diabetic peripheral neuropathy (DPN) is an essential precursor leading to diabetic limb loss. Neurologic screening tests, including the 128-Hz tuning fork (TF), have long been used to identify and track the progression of DPN, thereby guiding the implementation of preventive strategies. Although a sensitive indicator of neuropathy, shortcomings of TF testing include the lack of standardization and quantification of clinical findings. In an attempt to overcome these limitations, a novel 128-Hz electronic TF (ETF) prototype has been developed that is capable of performing accurate timed vibration tests (TVTs). This study was designed to assess the ability of the ETF to detect sensory impairment compared with three established neurologic screening methods: the Semmes-Weinstein monofilament test, the biothesiometer, and the sharp/dull discrimination test. Fifty-five test patients were recruited from the primary author's practice and enrolled according to an approved protocol. The 10-g Semmes-Weinstein monofilament test and the sharp/dull discrimination test were administered in standard fashion to the plantar aspects of digits 1 and 5 bilaterally. The ETF and the biothesiometer (25-V setting) were applied to the dorsal aspects of the distal phalanx of the hallux and fifth metatarsal head bilaterally. The sensitivity and specificity of neuropathy detection for the ETF were 0.953 and 0.761, respectively, using conventional tests as reference standards. Performance of TVTs with the ETF detected sensory impairment compared with three conventional neurologic screening methods. Given these findings, the ETF could facilitate the use of standardized TVTs as an indicator of DPN progression.

Recent advances of mid-infrared compact, field deployable sensors: principles and applications

NASA Astrophysics Data System (ADS)

Tittel, Frank; Gluszek, Aleksander; Hudzikowski, Arkadiusz; Dong, Lei; Li, Chunguang; Patimisco, Pietro; Sampaolo, Angelo; Spagnolo, Vincenzo; Wojtas, Jacek

2016-04-01

The recent development of compact interband cascade lasers(ICLs) and quantum cascade lasers (QCLs) based trace gas sensors will permit the targeting of strong fundamental rotational-vibrational transitions in the mid-infrared which are one to two orders of magnitude more intense than transitions in the overtone and combination bands in the near-infrared. This has led to the design and fabrication of mid-infrared compact, field deployable sensors for use in the petrochemical industry, environmental monitoring and atmospheric chemistry. Specifically, the spectroscopic detection and monitoring of four molecular species, methane (CH4) [1], ethane (C2H6), formaldehyde (H2CO) [2] and hydrogen sulphide (H2S) [3] will be described. CH4, C2H6 and H2CO can be detected using two detection techniques: mid-infrared tunable laser absorption spectroscopy (TDLAS) using a compact multi-pass gas cell and quartz enhanced photoacoustic spectroscopy (QEPAS). Both techniques utilize state-of-the-art mid-IR, continuous wave (CW), distributed feedback (DFB) ICLs and QCLs. TDLAS was performed with an ultra-compact 54.6m effective optical path length innovative spherical multipass gas cell capable of 435 passes between two concave mirrors separated by 12.5 cm. QEPAS used a small robust absorption detection module (ADM) which consists of a quartz tuning fork (QTF), two optical windows, gas inlet/outlet ports and a low noise frequency pre-amplifier. Wavelength modulation and second harmonic detection were employed for spectral data processing. TDLAS and QEPAS can achieve minimum detectable absorption losses in the range from 10-8 to 10-11cm-1/Hz1/2. Several recent examples of real world applications of field deployable gas sensors will be described. For example, an ICL based TDLAS sensor system is capable of detecting CH4 and C2H6 concentration levels of 1 ppb in a 1 sec. sampling time, using an ultra-compact, robust sensor architecture. H2S detection was realized with a THz QEPAS sensor system using a custom quartz tuning fork (QTF) with a new geometry and a QCL emitting at 2.913 THz [4]. Furthermore, two new approaches aimed to achieve enhanced detection sensitivities with QEPAS based sensing can be realized. The first method will make use of a compact optical power buildup cavity, which achieves significantly lower minimum detectable trace gas concentration levels of < 10 pptv. The second approach will use custom fabricated QTFs capable of improved detection sensitivity. Acknowledgements F.K. Tittel acknowledges support by the National Science Foundation (NSF) ERC MIRTHE award, the Robert Welch Foundation (Grant C-0586) and DOE ARPA-E Monitor Proram. L. Dong acknowledges support by NSF-China (Grant #s. 61275213, 61108030), J. Wojtas acknowledges support by The National Centre for Research and Development, Poland (project ID: 179616). References [1] L. Dong, C. Li, N. P. Sanchez, A. K. Gluszek, R. Griffin and F. K. Tittel;" Compact CH4 sensor system based on a continuous-wave, low power consumption, room temperature interband cascade laser", Appl. Phys Lett. 108, 011106 (2016). [2] L. Dong, Y. Yu, C. Li, S. So, and F.K. Tittel, "Ppb-level formaldehyde detection using a CW room-temperature interband cascade laser and a miniature dense pattern multipass cell" Optics Express; 23, 19821-19830 (2015). [3] V. Spagnolo, P. Patimisco, R. Pennetta, A. Sampaolo, G. Scamarcio, M. Vitiello, and F.K. Tittel, "THz Quartz-enhanced photoacoustic sensor for H2S trace gas detection", Opt. Exp. 23, 7574-7582 (2015). [4] A. Sampaolo, P. Patimisco, L. Dong , A. Geras, S, G. Scamarcio' T. Starecki, F.K Tittel, V. Spagnolo; "Quartz-Enhanced Photoacoustic Spectroscopy exploiting tuning fork overtone modes", Appl. Phys Lett. 107, 231102 (2015).

A diamond-based scanning probe spin sensor operating at low temperature in ultra-high vacuum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schaefer-Nolte, E.; Wrachtrup, J.; 3rd Institute of Physics and Research Center SCoPE, University Stuttgart, 70569 Stuttgart

2014-01-15

We present the design and performance of an ultra-high vacuum (UHV) low temperature scanning probe microscope employing the nitrogen-vacancy color center in diamond as an ultrasensitive magnetic field sensor. Using this center as an atomic-size scanning probe has enabled imaging of nanoscale magnetic fields and single spins under ambient conditions. In this article we describe an experimental setup to operate this sensor in a cryogenic UHV environment. This will extend the applicability to a variety of molecular systems due to the enhanced target spin lifetimes at low temperature and the controlled sample preparation under UHV conditions. The instrument combines amore » tuning-fork based atomic force microscope (AFM) with a high numeric aperture confocal microscope and the facilities for application of radio-frequency (RF) fields for spin manipulation. We verify a sample temperature of <50 K even for strong laser and RF excitation and demonstrate magnetic resonance imaging with a magnetic AFM tip.« less

Quantum Field Energy Sensor based on the Casimir Effect

NASA Astrophysics Data System (ADS)

Ludwig, Thorsten

The Casimir effect converts vacuum fluctuations into a measurable force. Some new energy technologies aim to utilize these vacuum fluctuations in commonly used forms of energy like electricity or mechanical motion. In order to study these energy technologies it is helpful to have sensors for the energy density of vacuum fluctuations. In today's scientific instrumentation and scanning microscope technologies there are several common methods to measure sub-nano Newton forces. While the commercial atomic force microscopes (AFM) mostly work with silicon cantilevers, there are a large number of reports on the use of quartz tuning forks to get high-resolution force measurements or to create new force sensors. Both methods have certain advantages and disadvantages over the other. In this report the two methods are described and compared towards their usability for Casimir force measurements. Furthermore a design for a quantum field energy sensor based on the Casimir force measurement will be described. In addition some general considerations on extracting energy from vacuum fluctuations will be given.

Fast contactless vibrating structure characterization using real time field programmable gate array-based digital signal processing: demonstrations with a passive wireless acoustic delay line probe and vision.

PubMed

Goavec-Mérou, G; Chrétien, N; Friedt, J-M; Sandoz, P; Martin, G; Lenczner, M; Ballandras, S

2014-01-01

Vibrating mechanical structure characterization is demonstrated using contactless techniques best suited for mobile and rotating equipments. Fast measurement rates are achieved using Field Programmable Gate Array (FPGA) devices as real-time digital signal processors. Two kinds of algorithms are implemented on FPGA and experimentally validated in the case of the vibrating tuning fork. A first application concerns in-plane displacement detection by vision with sampling rates above 10 kHz, thus reaching frequency ranges above the audio range. A second demonstration concerns pulsed-RADAR cooperative target phase detection and is applied to radiofrequency acoustic transducers used as passive wireless strain gauges. In this case, the 250 ksamples/s refresh rate achieved is only limited by the acoustic sensor design but not by the detection bandwidth. These realizations illustrate the efficiency, interest, and potentialities of FPGA-based real-time digital signal processing for the contactless interrogation of passive embedded probes with high refresh rates.

Environmental Assessment Housing Transfer at Grand Forks AFB, North Dakota

DTIC Science & Technology

2005-01-27

AIR FORCE BASE ...Equipment…………. 28 9 ACRONYMS, ABBREVIATIONS, AND TERMS AAM Annual Arithmetic Mean ACM Asbestos-Containing Material AFB Air Force Base AFI Air ...of No Significant Impact ft Feet ft3/s feet cubed per meter 10 GFAFB Grand Forks Air Force Base HAP Hazardous Air Pollutants hr Hour

Ultrahigh interlayer friction in multiwalled boron nitride nanotubes.

PubMed

Niguès, A; Siria, A; Vincent, P; Poncharal, P; Bocquet, L

2014-07-01

Friction at the nanoscale has revealed a wealth of behaviours that depart strongly from the long-standing macroscopic laws of Amontons-Coulomb. Here, by using a 'Christmas cracker'-type of system in which a multiwalled nanotube is torn apart between a quartz-tuning-fork-based atomic force microscope (TF-AFM) and a nanomanipulator, we compare the mechanical response of multiwalled carbon nanotubes (CNTs) and multiwalled boron nitride nanotubes (BNNTs) during the fracture and telescopic sliding of the layers. We found that the interlayer friction for insulating BNNTs results in ultrahigh viscous-like dissipation that is proportional to the contact area, whereas for the semimetallic CNTs the sliding friction vanishes within experimental uncertainty. We ascribe this difference to the ionic character of the BN, which allows charge localization. The interlayer viscous friction of BNNTs suggests that BNNT membranes could serve as extremely efficient shock-absorbing surfaces.

Mid-Infrared Fiber-Coupled QCl-QEPAS Sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spagnolo, V.; Patimisco, P.; Borri, Simone

2013-08-01

An innovative spectroscopic system based on an external cavity quantum cascade laser (EC-QCL) coupled with a mid-infrared (mid-IR) fiber and quartz enhanced photoacoustic spectroscopy (QEPAS) is described. SF6 has been selected as a target gas in demonstration of the system for trace gas sensing. Single mode laser delivery through the prongs of the quartz tuning fork has been obtained employing a hollow waveguide fiber with inner silver–silver iodine (Ag–AgI) coatings and internal core diameter of 300 lm. A detailed design and realization of the QCL fiber coupling and output collimator system allowed almost practically all (99.4 %) of the lasermore » beam to be transmitted through the spectrophone module. The achieved sensitivity of the system is 50 parts per trillion in 1 s, corresponding to a record for QEPAS normalized noise-equivalent absorption 2.7 9 10-10 W cm-1 Hz-1/2.« less

Refined tip preparation by electrochemical etching and ultrahigh vacuum treatment to obtain atomically sharp tips for scanning tunneling microscope and atomic force microscope.

PubMed

Hagedorn, Till; El Ouali, Mehdi; Paul, William; Oliver, David; Miyahara, Yoichi; Grütter, Peter

2011-11-01

A modification of the common electrochemical etching setup is presented. The described method reproducibly yields sharp tungsten tips for usage in the scanning tunneling microscope and tuning fork atomic force microscope. In situ treatment under ultrahigh vacuum (p ≤10(-10) mbar) conditions for cleaning and fine sharpening with minimal blunting is described. The structure of the microscopic apex of these tips is atomically resolved with field ion microscopy and cross checked with field emission. © 2011 American Institute of Physics

Temperature and frequency dependent mean free paths of renormalized phonons in nonlinear lattices

NASA Astrophysics Data System (ADS)

Li, Nianbei; Liu, Junjie; Wu, Changqin; Li, Baowen

2018-02-01

Unraveling general properties of renormalized phonons are of fundamental relevance to the heat transport in the regime of strong nonlinearity. In this work, we directly study the temperature and frequency dependent mean free path (MFP) of renormalized phonons with the newly developed numerical tuning fork method. The typical 1D nonlinear lattices such as Fermi-Pasta-Ulam β lattice and {φ }4 lattice are investigated in detail. Interestingly, it is found that the MFPs are inversely proportional to the frequencies of renormalized phonons rather than the square of phonon frequencies predicted by existing phonon scattering theory.

M sub-shell X-ray fluorescence cross-section measurements for six elements in the range Z = 78-92 at tuned synchrotron photon energies 5, 7 and 9 keV.

NASA Astrophysics Data System (ADS)

Bansal, Himani; Tiwari, M. K.; Mittal, Raj

2018-01-01

M sub-shell X-ray fluorescence cross-sections of elements Pt, Au, Hg, Pb, Th and U have been measured with linearly polarized photon beams from Indus-II synchrotron source at Raja Ramanna Centre for Advanced Technology (RRCAT), India at tuned 5, 7 and 9 keV energies less than the L3 edge energy of elements. Measurements at present energies and elements are not available in literature. Therefore, measured cross-sections for Mξ, Mδ, Mα, Mβ, Mγ, Mm1 and Mm2 group of X-rays were compared with calculated theoretical values based upon Non Relativistic Hartree-Slater (NRHS) and relativistic Dirac-Fork (DF) and Dirac-Hartree-Slater (DHS) models. The measured cross-sections along with our earlier quoted measurements at 8 and 10 keV by Kaur et al. [Nucl. Instrum. Meth. B, 2014; 320: 37] are found in good agreement with DF and DHS values around 20% deviations and are highly deviated from NRHS values. Most of the spots of observed high deviations in measured and theoretical cross-sections are found to coincide with the presence of crisscrosses/sharp variations in contributing physical parameters photo-ionization cross-sections σMi's and Coster-Kronig yields fij's with Zs.

Simultaneous binding to the tracking strand, displaced strand and the duplex of a DNA fork enhances unwinding by Dda helicase

PubMed Central

Aarattuthodiyil, Suja; Byrd, Alicia K.; Raney, Kevin D.

2014-01-01

Interactions between helicases and the tracking strand of a DNA substrate are well-characterized; however, the role of the displaced strand is a less understood characteristic of DNA unwinding. Dda helicase exhibited greater processivity when unwinding a DNA fork compared to a ss/ds DNA junction substrate. The lag phase in the unwinding progress curve was reduced for the forked DNA compared to the ss/ds junction. Fewer kinetic steps were required to unwind the fork compared to the ss/ds junction, suggesting that binding to the fork leads to disruption of the duplex. DNA footprinting confirmed that interaction of Dda with a fork leads to two base pairs being disrupted whereas no disruption of base pairing was observed with the ss/ds junction. Neutralization of the phosphodiester backbone resulted in a DNA-footprinting pattern similar to that observed with the ss/ds junction, consistent with disruption of the interaction between Dda and the displaced strand. Several basic residues in the 1A domain which were previously proposed to bind to the incoming duplex DNA were replaced with alanines, resulting in apparent loss of interaction with the duplex. Taken together, these results suggest that Dda interaction with the tracking strand, displaced strand and duplex coordinates DNA unwinding. PMID:25249618

Hidden dangers revealed by misdiagnosed diabetic neuropathy: A comparison of simple clinical tests for the screening of vibration perception threshold at primary care level.

PubMed

Azzopardi, Kurt; Gatt, Alfred; Chockalingam, Nachiappan; Formosa, Cynthia

2018-04-01

Diabetic peripheral neuropathy is an important complication and contributes to the morbidity of diabetes mellitus. Evidence indicates early detection of diabetic peripheral neuropathy results in fewer foot ulcers and amputations. The aim of this study was to compare different screening modalities in the detection of diabetic peripheral neuropathy in a primary care setting. A prospective non-experimental comparative multi-centre cross sectional study was conducted in various Primary Health Centres. One hundred participants living with Type 2 diabetes for at least 10 years were recruited using a convenience sampling method. The Vibratip, 128Hz tuning fork and neurothesiometer were compared in the detection of vibration perception. This study showed different results of diabetic peripheral neuropathy screening tests, even in the same group of participants. This study has shown that the percentage of participants who did not perceive vibrations was highest when using the VibraTip (28.5%). This was followed by the neurothesiometer (21%) and the 128Hz tuning fork (12%) (p<0.001). Correct diagnosis and treatment of neuropathy in patients with diabetes is crucial. This study demonstrates that some instruments are more sensitive to vibration perception than others. We recommend that different modalities should be used in patients with diabetes and when results do not concur, further neurological evaluation should be performed. This would significantly reduce the proportion of patients with diabetes who would be falsely identified as having no peripheral neuropathy and subsequently denied the benefit of beneficial and effective secondary risk factor control. Copyright © 2017 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.

The carpenter fork bed, a new - and older - Black-shale unit at the base of the New Albany shale in central Kentucky: Characterization and significance

USGS Publications Warehouse

Barnett, S.F.; Ettensohn, F.R.; Norby, R.D.

1996-01-01

Black shales previously interpreted to be Late Devonian cave-fill or slide deposits are shown to be much older Middle Devonian black shales only preserved locally in Middle Devonian grabens and structural lows in central Kentucky. This newly recognized - and older -black-shale unit occurs at the base of the New Albany Shale and is named the Carpenter Fork Bed of the Portwood Member of the New Albany Shale after its only known exposure on Carpenter Fork in Boyle County, central Kentucky; two other occurrences are known from core holes in east-central Kentucky. Based on stratigraphic position and conodont biostratigraphy, the unit is Middle Devonian (Givetian: probably Middle to Upper P. varcus Zone) in age and occurs at a position represented by an unconformity atop the Middle Devonian Boyle Dolostone and its equivalents elsewhere on the outcrop belt. Based on its presence as isolated clasts in the overlying Duffin Bed of the Portwood Member, the former distribution of the unit was probably much more widespread - perhaps occurring throughout western parts of the Rome trough. Carpenter Fork black shales apparently represent an episode of subsidence or sea-level rise coincident with inception of the third tectophase of the Acadian orogeny. Deposition, however, was soon interrupted by reactivation of several fault zones in central Kentucky, perhaps in response to bulge migration accompanying start of the tectophase. As a result, much of central Kentucky was uplifted and tilted, and the Carpenter Fork Bed was largely eroded from the top of the Boyle, except in a few structural lows like the Carpenter Fork graben where a nearly complete record of Middle to early Late Devonian deposition is preserved.

Geology, Streamflow, and Water Chemistry of the Talufofo Stream Basin, Saipan, Northern Mariana Islands

USGS Publications Warehouse

Izuka, Scot K.; Ewart, Charles J.

1995-01-01

A study of the geology, streamflow, and water chemistry of Talufofo Stream Basin, Saipan, Commonwealth of the Northern Mariana Islands, was undertaken to determine the flow characteristics of Talufofo Stream and the relation to the geology of the drainage basin. The Commonwealth government is exploring the feasibility of using water from Talufofo Stream to supplement Saipan's stressed municipal water supply. Streamflow records from gaging stations on the principal forks of Talufofo Stream indicate that peak streamflows and long-term average flow are higher at the South Fork gaging station than at the Middle Fork gaging station because the drainage area of the South Fork gaging station is larger, but persistent base flow from ground-water discharge during dry weather is greater in the Middle Fork gaging station. The sum of the average flows at the Middle Fork and South Fork gaging stations, plus an estimate of the average flow at a point in the lower reaches of the North Fork, is about 2.96 cubic feet per second or 1.91 million gallons per day. Although this average represents the theoretical maximum long-term draft rate possible from the Talufofo Stream Basin if an adequate reservoir can be built, the actual amount of surface water available will be less because of evaporation, leaks, induced infiltration, and reservoir-design constraints. Base-flow characteristics, such as stream seepage and spring discharge, are related to geology of the basin. Base flow in the Talufofo Stream Basin originates as discharge from springs near the base of limestones located in the headwaters of Talufofo Stream, flows over low-permeability volcanic rocks in the middle reaches, and seeps back into the high-permeability limestones in the lower reaches. Water sampled from Talufofo Stream during base flow had high dissolved-calcium concentrations (between 35 and 98 milligrams per liter), characteristic of water from a limestone aquifer. Concentrations of potassium, sodium, and chloride ions in water samples from Talufofo Stream are characteristic of water draining a heavily vegetated basin near the ocean. The streamflow and water-chemistry data indicate that discharge from springs is in hydraulic connection with the limestone aquifer near the headwaters of the basin. The base flow therefore is subject to stresses placed on the nearby limestone ground-water system. Pumping from wells in the limestones at the headwaters of Talufofo Stream Basin may decrease spring flow in Talufofo Stream.

Evaluation and optimization of quartz resonant-frequency retuned fork force sensors with high Q factors, and the associated electric circuits, for non-contact atomic force microscopy.

PubMed

Ooe, Hiroaki; Fujii, Mikihiro; Tomitori, Masahiko; Arai, Toyoko

2016-02-01

High-Q factor retuned fork (RTF) force sensors made from quartz tuning forks, and the electric circuits for the sensors, were evaluated and optimized to improve the performance of non-contact atomic force microscopy (nc-AFM) performed under ultrahigh vacuum (UHV) conditions. To exploit the high Q factor of the RTF sensor, the oscillation of the RTF sensor was excited at its resonant frequency, using a stray capacitance compensation circuit to cancel the excitation signal leaked through the stray capacitor of the sensor. To improve the signal-to-noise (S/N) ratio in the detected signal, a small capacitor was inserted before the input of an operational (OP) amplifier placed in an UHV chamber, which reduced the output noise from the amplifier. A low-noise, wideband OP amplifier produced a superior S/N ratio, compared with a precision OP amplifier. The thermal vibrational density spectra of the RTF sensors were evaluated using the circuit. The RTF sensor with an effective spring constant value as low as 1000 N/m provided a lower minimum detection limit for force differentiation. A nc-AFM image of a Si(111)-7 × 7 surface was produced with atomic resolution using the RTF sensor in a constant frequency shift mode; tunneling current and energy dissipation images with atomic resolution were also simultaneously produced. The high-Q factor RTF sensor showed potential for the high sensitivity of energy dissipation as small as 1 meV/cycle and the high-resolution analysis of non-conservative force interactions.

The mini-O, a digital superhet, or a truly low-cost Omega navigation receiver

NASA Technical Reports Server (NTRS)

Burhans, R. W.

1975-01-01

A quartz tuning fork filter circuit and some unique CMOS clock logic methods provide a very simple OMEGA-VLF receiver with true hyperbolic station pair phase difference outputs. An experimental system was implemented on a single battery-operated circuit board requiring only an external antenna preamplifier, and LOP output recorder. A bench evaluation and preliminary navigation tests indicate the technique is viable and can provide very low-cost OMEGA measurement systems. The method is promising for marine use with small boats in the present form, but might be implemented in conjunction with digital microprocessors for airborne navigation aids.

Unraveling fabrication and calibration of wearable gas monitor for use under free-living conditions.

PubMed

Yue Deng; Cheng Chen; Tsow, Francis; Xiaojun Xian; Forzani, Erica

2016-08-01

Volatile organic compounds (VOC) are organic chemicals that have high vapor pressure at regular conditions. Some VOC could be dangerous to human health, therefore it is important to determine real-time indoor and outdoor personal exposures to VOC. To achieve this goal, our group has developed a wearable gas monitor with a complete sensor fabrication and calibration protocol for free-living conditions. Correction factors for calibrating the sensors, including sensitivity, aging effect, and temperature effect are implemented into a Quick Response Code (QR code), so that the pre-calibrated quartz tuning fork (QTF) sensor can be used with the wearable monitor under free-living conditions.

Manipulation of nanoparticles of different shapes inside a scanning electron microscope

PubMed Central

Polyakov, Boris; Dorogin, Leonid M; Butikova, Jelena; Antsov, Mikk; Oras, Sven; Lõhmus, Rünno; Kink, Ilmar

2014-01-01

Summary In this work polyhedron-like gold and sphere-like silver nanoparticles (NPs) were manipulated on an oxidized Si substrate to study the dependence of the static friction and the contact area on the particle geometry. Measurements were performed inside a scanning electron microscope (SEM) that was equipped with a high-precision XYZ-nanomanipulator. To register the occurring forces a quartz tuning fork (QTF) with a glued sharp probe was used. Contact areas and static friction forces were calculated by using different models and compared with the experimentally measured force. The effect of NP morphology on the nanoscale friction is discussed. PMID:24605279

Measuring and characterizing beat phenomena with a smartphone

NASA Astrophysics Data System (ADS)

Osorio, M.; Pereyra, C. J.; Gau, D. L.; Laguarda, A.

2018-03-01

Nowadays, smartphones are in everyone’s life. Apart from being excellent tools for work and communication, they can also be used to perform several measurements of simple physical magnitudes, serving as a mobile and inexpensive laboratory, ideal for use physics lectures in high schools or universities. In this article, we use a smartphone to analyse the acoustic beat phenomena by using a simple experimental setup, which can complement lessons in the classroom. The beats were created by the superposition of the waves generated by two tuning forks, with their natural frequencies previously characterized using different applications. After the characterization, we recorded the beats and analysed the oscillations in time and frequency.

Allan Deviation Plot as a Tool for Quartz-Enhanced Photoacoustic Sensors Noise Analysis.

PubMed

Giglio, Marilena; Patimisco, Pietro; Sampaolo, Angelo; Scamarcio, Gaetano; Tittel, Frank K; Spagnolo, Vincenzo

2016-04-01

We report here on the use of the Allan deviation plot to analyze the long-term stability of a quartz-enhanced photoacoustic (QEPAS) gas sensor. The Allan plot provides information about the optimum averaging time for the QEPAS signal and allows the prediction of its ultimate detection limit. The Allan deviation can also be used to determine the main sources of noise coming from the individual components of the sensor. Quartz tuning fork thermal noise dominates for integration times up to 275 s, whereas at longer averaging times, the main contribution to the sensor noise originates from laser power instabilities.

Installation Restoration Program, Phase 2. Confirmation/Quantification, Stage 1. Kalispell Air Force Station, Montana

DTIC Science & Technology

1989-05-01

AFB Statement of Work. The Phase II Stage 1 investigation of Malmstrom AFB and two off-Base sites at Shelby and Brady, Montana are described in a...Flathead National Forest Headquarters in Kalispell and the Big Fork Ranger Station in Big Fork . Because there has been litigation involved with this...reviewed by phone. An interview at the spill site was held with Mr. William Pedersen, U.S. Forest Service Ranger for the Big Fork District. He personally

Base flow (1966-2009) and streamflow gain and loss (2010) of the Brazos River from the New Mexico-Texas State line to Waco, Texas

USGS Publications Warehouse

Baldys, Stanley; Schalla, Frank E.

2012-01-01

Streamflow was measured at 66 sites from June 6–9, 2010, and at 68 sites from October 16–19, 2010, to identify reaches in the upper Brazos River Basin that were gaining or losing streamflow. Gaining reaches were identified in each of the five subbasins. The gaining reach in the Salt Fork Brazos River Basin began at USGS streamflow-gaging station 08080940 Salt Fork Brazos River at State Highway 208 near Clairemont, Tex. (site SF–6), upstream from where Duck Creek flows into the Salt Fork Brazos River and continued downstream past USGS streamflow-gaging station 08082000 Salt Fork Brazos River near Aspermont, Tex. (site SF–9), to the outlet of the basin. In the Double Mountain Fork Brazos River Basin, a gaining reach from near Post, Tex., downstream to the outlet of the basin was identified. Two gaining reaches were identified in the Clear Fork Brazos River Basin—one from near Roby, Tex., downstream to near Noodle, Tex., and second from Hawley, Tex., downstream to Nugent, Tex. Most of the North Bosque River was characterized as gaining streamflow. Streamflow gains were identified in the main stem of the Brazos River from where the Brazos River main stem forms at the confluence of the Salt Fork Brazos River and Double Mountain Fork Brazos River near Knox City, Tex., downstream to near Seymour, Tex.

Design and Characterization of a Novel Bio-inspired Hair Flow Sensor Based on Resonant Sensing

NASA Astrophysics Data System (ADS)

Guo, X.; Yang, B.; Wang, Q. H.; Lu, C. F.; Hu, D.

2018-03-01

Flow sensors inspired by the natural hair sensing mechanism have great prospect in the research of micro-autonomous system and technology (MAST) for the three-dimensional structure characteristics with high spatial and quality utilization. A novel bio-inspired hair flow sensor (BHFS) based on resonant sensing with a unique asymmetric design is presented in this paper. A hair transducer and a signal detector which is constituted of a two-stage micro-leverage mechanism and two symmetrical resonators (double ended tuning fork, DETF) are adopted to realize the high sensitivity to air flow. The sensitivity of the proposed BHFS is improved significantly than the published ones due to the high sensitivity of resonators and the higher amplification factor possessed by the two-stage micro-leverage mechanism. The standard deep dry silicon on glass (DDSOG) process is chosen to fabricate the proposed BHFS. The experiment result demonstrates that the fabricated BHFS has a mechanical sensitivity of 5.26 Hz/(m/s)2 at a resonant frequency of 22 kHz with the hair height of 6 mm.

MEMS resonant load cells for micro-mechanical test frames: feasibility study and optimal design

NASA Astrophysics Data System (ADS)

Torrents, A.; Azgin, K.; Godfrey, S. W.; Topalli, E. S.; Akin, T.; Valdevit, L.

2010-12-01

This paper presents the design, optimization and manufacturing of a novel micro-fabricated load cell based on a double-ended tuning fork. The device geometry and operating voltages are optimized for maximum force resolution and range, subject to a number of manufacturing and electromechanical constraints. All optimizations are enabled by analytical modeling (verified by selected finite elements analyses) coupled with an efficient C++ code based on the particle swarm optimization algorithm. This assessment indicates that force resolutions of ~0.5-10 nN are feasible in vacuum (~1-50 mTorr), with force ranges as large as 1 N. Importantly, the optimal design for vacuum operation is independent of the desired range, ensuring versatility. Experimental verifications on a sub-optimal device fabricated using silicon-on-glass technology demonstrate a resolution of ~23 nN at a vacuum level of ~50 mTorr. The device demonstrated in this article will be integrated in a hybrid micro-mechanical test frame for unprecedented combinations of force resolution and range, displacement resolution and range, optical (or SEM) access to the sample, versatility and cost.

[Quartz-enhanced photoacoustic spectroscopy trace gas detection system based on the Fabry-Perot demodulation].

PubMed

Lin, Cheng; Zhu, Yong; Wei, Wei; Zhang, Jie; Tian, Li; Xu, Zu-Wen

2013-05-01

An all-optical quartz-enhanced photoacoustic spectroscopy system, based on the F-P demodulation, for trace gas detection in the open environment was proposed. In quartz-enhanced photoacoustic spectroscopy (QEPAS), an optical fiber Fabry-Perot method was used to replace the conventional electronic demodulation method. The photoacoustic signal was obtained by demodulating the variation of the Fabry-Perot cavity between the quartz tuning fork side and the fiber face. An experimental system was setup. The experiment for detection of water vapour in the open environment was carried on. A normalized noise equivalent absorption coefficient of 2.80 x 10(-7) cm(-1) x W x Hz(-1/2) was achieved. The result demonstrated that the sensitivity of the all-optical quartz-enhanced photoacoustic spectroscopy system is about 2.6 times higher than that of the conventional QEPAS system. The all-optical quartz-enhanced photoacoustic spectroscopy system is immune to electromagnetic interference, safe in flammable and explosive gas detection, suitable for high temperature and high humidity environments and realizable for long distance, multi-point and network sensing.

Replication fork reversal triggers fork degradation in BRCA2-defective cells.

PubMed

Mijic, Sofija; Zellweger, Ralph; Chappidi, Nagaraja; Berti, Matteo; Jacobs, Kurt; Mutreja, Karun; Ursich, Sebastian; Ray Chaudhuri, Arnab; Nussenzweig, Andre; Janscak, Pavel; Lopes, Massimo

2017-10-16

Besides its role in homologous recombination, the tumor suppressor BRCA2 protects stalled replication forks from nucleolytic degradation. Defective fork stability contributes to chemotherapeutic sensitivity of BRCA2-defective tumors by yet-elusive mechanisms. Using DNA fiber spreading and direct visualization of replication intermediates, we report that reversed replication forks are entry points for fork degradation in BRCA2-defective cells. Besides MRE11 and PTIP, we show that RAD52 promotes stalled fork degradation and chromosomal breakage in BRCA2-defective cells. Inactivation of these factors restores reversed fork frequency and chromosome integrity in BRCA2-defective cells. Conversely, impairing fork reversal prevents fork degradation, but increases chromosomal breakage, uncoupling fork protection, and chromosome stability. We propose that BRCA2 is dispensable for RAD51-mediated fork reversal, but assembles stable RAD51 nucleofilaments on regressed arms, to protect them from degradation. Our data uncover the physiopathological relevance of fork reversal and illuminate a complex interplay of homologous recombination factors in fork remodeling and stability.BRCA2 is involved in both homologous recombination (HR) and the protection of stalled replication forks from degradation. Here the authors reveal how HR factors cooperate in fork remodeling, showing that BRCA2 supports RAD51 loading on the regressed arms of reversed replication forks to protect them from degradation.

77 FR 50668 - Proposed Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-22

... County, Texas, and Incorporated Areas. Specifically, it addresses the flooding sources: Black Fork Creek, Black Fork Creek Tributary BF-1, Black Fork Creek Tributary BF-M-1, Black Fork Creek Tributary D, Black Fork Creek Tributary D-1, Black Fork Creek Tributary D-2, Black Fork Creek Tributary D-3, Butler Creek...

Salmon Supplementation Studies in Idaho Rivers, 1996-1998 Progress Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reighn, Christopher A.; Lewis, Bert; Taki, Doug

1999-06-01

Information contained in this report summarizes the work that has been done by the Shoshone-Bannock Tribes Fisheries Department under BPA Project No. 89-098-3, Contract Number 92-BI-49450. Relevant data generated by the Shoshone-Bannock Tribe will be collated with other ISS cooperator data collected from the Salmon and Clearwater rivers and tributary streams. A summary of data presented in this report and an initial project-wide level supplementation evaluation will be available in the ISS 5 year report that is currently in progress. The Shoshone-Bannock Tribal Fisheries Department is responsible for monitoring a variety of chinook salmon (Oncorhynchus tshawytscha) production parameters as partmore » of the Idaho Supplementation Studies (BPA Project No. 89-098-3, Contract Number 92-BI-49450). Parameters include parr abundance in tributaries to the upper Salmon River; adult chinook salmon spawner abundance, redd counts, and carcass collection. A rotary screw trap is operated on the East Fork Salmon River and West Fork Yankee Fork Salmon River to enumerate and PIT-tag chinook smolts. These traps are also used to monitor parr movement, and collect individuals for the State and Tribal chinook salmon captive rearing program. The SBT monitors fisheries parameters in the following six tributaries of the Salmon River: Bear Valley Creek, East Fork Salmon River, Herd Creek, South Fork Salmon River, Valley Creek, and West Fork Yankee Fork. Chinook populations in all SBT-ISS monitored streams continue to decline. The South Fork Salmon River and Bear Valley Creek have the strongest remaining populations. Snorkel survey methodology was used to obtain parr population estimates for ISS streams from 1992 to 1997. Confidence intervals for the parr population estimates were large, especially when the populations were low. In 1998, based on ISS cooperator agreement, snorkeling to obtain parr population estimates was ceased due to the large confidence intervals. A rotary screw trap was operated on the West Fork Yankee Fork during the spring, summer, and fall of 1998 to monitor juvenile chinook migration. A screw trap was also operated on the East Fork of the Salmon River during the spring and fall from 1993 to 1997. Supplementation treatments have occurred on the South Fork Salmon River (IDFG), the East Fork Salmon River (EFSR), and the West Fork Yankee Fork of the Salmon River (WFYF). The EFSR received supplementation treatments yearly through 1995. There have been no treatments since 1995, and no significant future treatments from local broodstock are planned due to extremely poor escapement. The WFYF received a single presmolt treatment in 1994. There was an egg and adult release treatment in 1998 from the captive rearing program, not part of the original ISS study. Similarly, no significant future treatments are planned for the West Fork Yankee Fork due to extremely poor escapement. However, small scale experimental captive rearing and broodstock techniques are currently being tested with populations from the EFSR and WFYF. Captive rearing/broodstock techniques could potentially provide feedback for evaluation of supplementation. The other three SBT-ISS streams are control streams and do not receive supplementation treatments.« less

Pairwise frictional profile between particles determines discontinuous shear thickening transition in non-colloidal suspensions

PubMed Central

Comtet, Jean; Chatté, Guillaume; Niguès, Antoine; Bocquet, Lydéric; Siria, Alessandro; Colin, Annie

2017-01-01

The process by which sheared suspensions go through a dramatic change in viscosity is known as discontinuous shear thickening. Although well-characterized on the macroscale, the microscopic mechanisms at play in this transition are still poorly understood. Here, by developing new experimental procedures based on quartz-tuning fork atomic force microscopy, we measure the pairwise frictional profile between approaching pairs of polyvinyl chloride and cornstarch particles in solvent. We report a clear transition from a low-friction regime, where pairs of particles support a finite normal load, while interacting purely hydrodynamically, to a high-friction regime characterized by hard repulsive contact between the particles and sliding friction. Critically, we show that the normal stress needed to enter the frictional regime at nanoscale matches the critical stress at which shear thickening occurs for macroscopic suspensions. Our experiments bridge nano and macroscales and provide long needed demonstration of the role of frictional forces in discontinuous shear thickening. PMID:28561032

Shear thinning in non-Brownian suspensions.

PubMed

Chatté, Guillaume; Comtet, Jean; Niguès, Antoine; Bocquet, Lydéric; Siria, Alessandro; Ducouret, Guylaine; Lequeux, François; Lenoir, Nicolas; Ovarlez, Guillaume; Colin, Annie

2018-02-14

We study the flow of suspensions of non-Brownian particles dispersed into a Newtonian solvent. Combining capillary rheometry and conventional rheometry, we evidence a succession of two shear thinning regimes separated by a shear thickening one. Through X-ray radiography measurements, we show that during each of those regimes, the flow remains homogeneous and does not involve particle migration. Using a quartz-tuning fork based atomic force microscope, we measure the repulsive force profile and the microscopic friction coefficient μ between two particles immersed into the solvent, as a function of normal load. Coupling measurements from those three techniques, we propose that (1) the first shear-thinning regime at low shear rates occurs for a lubricated rheology and can be interpreted as a decrease of the effective volume fraction under increasing particle pressures, due to short-ranged repulsive forces and (2) the second shear thinning regime after the shear-thickening transition occurs for a frictional rheology and can be interpreted as stemming from a decrease of the microscopic friction coefficient at large normal load.

Pairwise frictional profile between particles determines discontinuous shear thickening transition in non-colloidal suspensions.

PubMed

Comtet, Jean; Chatté, Guillaume; Niguès, Antoine; Bocquet, Lydéric; Siria, Alessandro; Colin, Annie

2017-05-31

The process by which sheared suspensions go through a dramatic change in viscosity is known as discontinuous shear thickening. Although well-characterized on the macroscale, the microscopic mechanisms at play in this transition are still poorly understood. Here, by developing new experimental procedures based on quartz-tuning fork atomic force microscopy, we measure the pairwise frictional profile between approaching pairs of polyvinyl chloride and cornstarch particles in solvent. We report a clear transition from a low-friction regime, where pairs of particles support a finite normal load, while interacting purely hydrodynamically, to a high-friction regime characterized by hard repulsive contact between the particles and sliding friction. Critically, we show that the normal stress needed to enter the frictional regime at nanoscale matches the critical stress at which shear thickening occurs for macroscopic suspensions. Our experiments bridge nano and macroscales and provide long needed demonstration of the role of frictional forces in discontinuous shear thickening.

3. View of Clark Fork Vehicle Bridge facing southwest. Bridge ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. View of Clark Fork Vehicle Bridge facing southwest. Bridge from north shore of Clark Fork River. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

4. View of Clark Fork Vehicle Bridge facing northeast. Bridge ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. View of Clark Fork Vehicle Bridge facing northeast. Bridge from south shoreof Clark Fork River showing 4 spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

Final Environmental Assessment Demolition of Alpha Ramp, Grand Forks Air Force Base, North Dakota

DTIC Science & Technology

2007-01-01

including spring wheat, barley, sunflowers, potatoes, and sugar beets. Uncultivated lands are generally used for pasture and hay, urban...Forks, ND 58203 Jack HOURS; Adul* Mon.-Sat. 12 noon - 6pm Main www.gfpets.com (next to Dairy Queen) Emerado, ND 58228 * Competitive prices & Monthly

Hydrogeology and simulated groundwater flow and availability in the North Fork Red River aquifer, southwest Oklahoma, 1980–2013

USGS Publications Warehouse

Smith, S. Jerrod; Ellis, John H.; Wagner, Derrick L.; Peterson, Steven M.

2017-09-28

On September 8, 1981, the Oklahoma Water Resources Board established regulatory limits on the maximum annual yield of groundwater (343,042 acre-feet per year) and equal-proportionate-share (EPS) pumping rate (1.0 acre-foot per acre per year) for the North Fork Red River aquifer. The maximum annual yield and EPS were based on a hydrologic investigation that used a numerical groundwater-flow model to evaluate the effects of potential groundwater withdrawals on groundwater availability in the North Fork Red River aquifer. The Oklahoma Water Resources Board is statutorily required (every 20 years) to update the hydrologic investigation on which the maximum annual yield and EPS were based. Because 20 years have elapsed since the final order was issued, the U.S. Geological Survey, in cooperation with the Oklahoma Water Resources Board, conducted an updated hydrologic investigation and evaluated the effects of potential groundwater withdrawals on groundwater flow and availability in the North Fork Red River aquifer in Oklahoma. This report describes a hydrologic investigation of the North Fork Red River aquifer that includes an updated summary of the aquifer hydrogeology. As part of this investigation, groundwater flow and availability were simulated by using a numerical groundwater-flow model.The North Fork Red River aquifer in Beckham, Greer, Jackson, Kiowa, and Roger Mills Counties in Oklahoma is composed of about 777 square miles (497,582 acres) of alluvium and terrace deposits along the North Fork Red River and tributaries, including Sweetwater Creek, Elk Creek, Otter Creek, and Elm Fork Red River. The North Fork Red River is the primary source of surface-water inflow to Lake Altus, which overlies the North Fork Red River aquifer. Lake Altus is a U.S. Bureau of Reclamation reservoir with the primary purpose of supplying irrigation water to the Lugert-Altus Irrigation District.A hydrogeologic framework was developed for the North Fork Red River aquifer and included a definition of the aquifer extent and potentiometric surface, as well as a description of the textural and hydraulic properties of aquifer materials. The hydrogeologic framework was used in the construction of a numerical groundwater-flow model of the North Fork Red River aquifer described in this report. A conceptual model of aquifer inflows and outflows was developed for the North Fork Red River aquifer to constrain the construction and calibration of a numerical groundwater-flow model that reasonably represented the groundwater-flow system. The conceptual-model water budget estimated mean annual inflows to and outflows from the North Fork Red River aquifer for the period 1980–2013 and included a sub-accounting of mean annual inflows and outflows for the portions of the aquifer that were upgradient and downgradient from Lake Altus. The numerical groundwater-flow model simulated the period 1980–2013 and was calibrated to water-table-altitude observations at selected wells, monthly base flow at selected streamgages, net streambed seepage as estimated for the conceptual model, and Lake Altus stage.Groundwater-availability scenarios were performed by using the calibrated numerical groundwater-flow model to (1) estimate the EPS pumping rate that guarantees a minimum 20-, 40-, and 50-year life of the aquifer, (2) quantify the potential effects of projected well withdrawals on groundwater storage over a 50-year period, and (3) simulate the potential effects of a hypothetical (10-year) drought on base flow and groundwater storage. The results of the groundwater-availability scenarios could be used by the Oklahoma Water Resources Board to reevaluate the maximum annual yield of groundwater from the North Fork Red River aquifer.EPS scenarios for the North Fork Red River aquifer were run for periods of 20, 40, and 50 years. The 20-, 40-, and 50-year EPS pumping rates under normal recharge conditions were 0.59, 0.52, and 0.52 acre-foot per acre per year, respectively. Given the 497,582-acre aquifer area, these rates correspond to annual yields of about 294,000, 259,000, and 259,000 acre-feet per year, respectively. Groundwater storage at the end of the 20-year EPS scenario was about 951,000 acre-feet, or about 1,317,000 acre-feet (58 percent) less than the starting EPS scenario storage. This decrease in storage was equivalent to a mean water-level decline of about 22 feet. Most areas of the active alluvium near the North Fork Red River, Elk Creek, and Elm Fork Red River remained partially saturated through the end of the EPS scenario because of streambed seepage. Lake Altus storage was reduced to zero after 6–7 years of EPS pumping in each scenario.Projected 50-year pumping scenarios were used to simulate the effects of selected well withdrawal rates on groundwater storage of the North Fork Red River aquifer and base flows in the North Fork Red River upstream from Lake Altus. The effects of well withdrawals were evaluated by comparing changes in groundwater storage and base flow between four 50-year scenarios using (1) no groundwater pumping, (2) mean pumping rates for the study period (1980–2013), (3) 2013 pumping rates, and (4) increasing demand pumping rates. The increasing demand pumping rates assumed a 20.4-percent increase in pumping over 50 years based on 2010–60 demand projections for southwest Oklahoma.Groundwater storage after 50 years with no pumping was about 2,606,000 acre-feet, or 137,000 acre-feet (5.5 percent) greater than the initial groundwater storage; this groundwater storage increase is equivalent to a mean water-level increase of 2.3 feet. Groundwater storage after 50 years with the mean pumping rate for the study period (1980–2013) was about 2,476,000 acre-feet, or about 7,000 acre-feet (0.3 percent) greater than the initial groundwater storage; this groundwater storage increase is equivalent to a mean water-level increase of 0.1 foot. Groundwater storage at the end of the 50-year period with 2013 pumping rates was about 2,398,000 acre-feet, or about 70,000 acre-feet (2.8 percent) less than the initial storage; this groundwater storage decrease is equivalent to a mean water-level decline of 1.2 feet. Groundwater storage at the end of the 50-year period with increasing demand pumping rates was about 2,361,000 acre-feet, or about 107,000 acre-feet (4.3 percent) less than the initial storage; this groundwater storage decrease is equivalent to a mean water-level decline of 1.8 feet. Mean annual base flow simulated at the Carter streamgage (07301500) on North Fork Red River increased by about 4,000 acre-feet (10 percent) after 50 years with no pumping and decreased by about 5,400 acre-feet (13 percent) after 50 years with increasing demand pumping rates. Mean annual base flow simulated at the North Fork Red River inflow to Lake Altus increased by about 7,400 acre-feet (15 percent) after 50 years with no pumping and decreased by about 5,800 acre-feet (12 percent) after 50 years with increasing demand pumping rates.A hypothetical 10-year drought scenario was used to simulate the effects of a prolonged period of reduced recharge on groundwater storage and Lake Altus stage and storage. Drought effects were quantified by comparing the results of the drought scenario to those of the calibrated numerical model (no drought). To simulate the hypothetical drought, recharge in the calibrated numerical model was reduced by 50 percent during the simulated drought period (1984–1993). Groundwater storage at the end of the drought period was about 2,271,000 acre-feet, or about 426,000 acre-feet (15.8 percent) less than the groundwater storage of the calibrated numerical model. This decrease in groundwater storage is equivalent to a mean water-table-altitude decline of 7.1 feet. At the end of the 10-year hypothetical drought period, base flows at the Sweetwater (07301420), Carter (07301500), Headrick (07305000), and Snyder (07307010) streamgages had decreased by about 37, 61, 44, and 45 percent, respectively. The minimum Lake Altus storage simulated during the drought period was 403 acre-feet, which was a decline of 92 percent from the nondrought storage. Reduced base flows in the North Fork Red River were the primary cause of Lake Altus storage declines.

2. View of Clark Fork Vehicle Bridge facing northeast. Bridge ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. View of Clark Fork Vehicle Bridge facing northeast. Bridge from south shore of Clark Fork River showing 4 1/2 spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

7. View of Clark Fork Vehicle Bridge facing northwest. Bridge ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. View of Clark Fork Vehicle Bridge facing northwest. Bridge from south shore of Clark Fork River showing 4 1/2 spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

1. View of Clark Fork Vehicle Bridge facing west. Panorama ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. View of Clark Fork Vehicle Bridge facing west. Panorama showing the entire span of bridge from north shore of the Clark Fork River. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

Silent Sentry

NASA Technical Reports Server (NTRS)

1980-01-01

NASA developed personal security system, commercialized by Sentry Products, Inc. enables resident to summon instant help in case of medical emergency or threatened violence. Its principal elements are a pen-shaped signaling device, "silent" because its ultrasonic alert signal is inaudible to the human ear, and a system of receivers interconnected with a constantly-monitored aster console. SCAN pen weighs only two ounces and is worn on necklace or attached by a clip to the user's clothing. The person in trouble simply presses a clasp, releasing a hammer inside the pen which strikes an aluminum bar. The impact causes the bar to resonate like a tuning fork and emit the ultrasonic signal, which is detected by the nearest receiver.

A Miniaturized QEPAS Trace Gas Sensor with a 3D-Printed Acoustic Detection Module.

PubMed

Yang, Xiaotao; Xiao, Youhong; Ma, Yufei; He, Ying; Tittel, Frank K

2017-07-31

A 3D printing technique was introduced to a quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor and is reported for the first time. The acoustic detection module (ADM) was designed and fabricated using the 3D printing technique and the ADM volume was compressed significantly. Furthermore, a small grin lens was used for laser focusing and facilitated the beam adjustment in the 3D-printed ADM. A quartz tuning fork (QTF) with a low resonance frequency of 30.72 kHz was used as the acoustic wave transducer and acetylene (C₂H₂) was chosen as the analyte. The reported miniaturized QEPAS trace gas sensor is useful in actual sensor applications.

5. View of Clark Fork Vehicle Bridge facing east. Bridge ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. View of Clark Fork Vehicle Bridge facing east. Bridge from south shore of Clark Fork River-southernmost span. 1900-era Northern Pacific Railway Bridge in background. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

The Late Cretaceous Middle Fork caldera, its resurgent intrusion, and enduring landscape stability in east-central Alaska

USGS Publications Warehouse

Bacon, Charles R.; Dusel-Bacon, Cynthia; Aleinikoff, John N.; Slack, John F.

2014-01-01

The Middle Fork is a relatively well preserved caldera within a broad region of Paleozoic metamorphic rocks and Mesozoic plutons bounded by northeast-trending faults. In the relatively downdropped and less deeply exhumed crustal blocks, Cretaceous–Early Tertiary silicic volcanic rocks attest to long-term stability of the landscape. Within the Middle Fork caldera, the granite porphyry is interpreted to have been exposed by erosion of thick intracaldera tuff from an asymmetric resurgent dome. The Middle Fork of the North Fork of the Fortymile River incised an arcuate valley into and around the caldera fill on the west and north and may have cut down from within an original caldera moat. The 70 Ma land surface is preserved beneath proximal outflow tuff at the west margin of the caldera structure and beneath welded outflow tuff 16–23 km east-southeast of the caldera in a paleovalley. Within ∼50 km of the Middle Fork caldera are 14 examples of Late Cretaceous (?)–Tertiary felsic volcanic and hypabyssal intrusive rocks that range in area from <1 km2 to ∼100 km2. Rhyolite dome clusters north and northwest of the caldera occupy tectonic basins associated with northeast-trending faults and are relatively little eroded. Lava of a latite complex, 12–19 km northeast of the caldera, apparently flowed into the paleovalley of the Middle Fork of the North Fork of the Fortymile River. To the northwest of the Middle Fork caldera, in the Mount Harper crustal block, mid-Cretaceous plutonic rocks are widely exposed, indicating greater total exhumation. To the southeast of the Middle Fork block, the Mount Veta block has been uplifted sufficiently to expose a ca. 68–66 Ma equigranular granitic pluton. Farther to the southeast, in the Kechumstuk block, the flat-lying outflow tuff remnant in Gold Creek and a regionally extensive high terrace indicate that the landscape there has been little modified since 70 Ma other than entrenchment of tributaries in response to post–2.7 Ma lowering of base level of the Yukon River associated with advance of the Cordilleran ice sheet.

"Forked Tongue: The Politics of Bilingual Education," by Rosalie Pedalino Porter. Book Review.

ERIC Educational Resources Information Center

Amabisca, Anastasia Aimee

1994-01-01

Based on personal experience rather than empirical evidence, "Forked Tongue" presents a biased view that could damage the future of bilingual education in the United States. The book considers bilingual education a threat because it prolongs the learning of English and promotes the maintenance of other "un-American" languages…

Theoretical and experimental study of the dynamic response of absorber-based, micro-scale, oscillatory probes for contact sensing applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kafashi, Sajad, E-mail: skafashi@uncc.edu; Strayhorn, Ralph; Smith, Stuart T.

2016-06-15

This paper presents two models for predicting the frequency response of micro-scale oscillatory probes. These probes are manufactured by attaching a thin fiber to the free end of one tine of a quartz tuning fork oscillator. In these studies, the attached fibers were either 75 μm diameter tungsten or 7 μm diameter carbon with lengths ranging from around 1 to 15 mm. The oscillators used in these studies were commercial 32.7 kHz quartz tuning forks. The first theoretical model considers lateral vibration of two beams serially connected and provides a characteristic equation from which the roots (eigenvalues) are extracted tomore » determine the natural frequencies of the probe. A second, lumped model approximation is used to derive an approximate frequency response function for prediction of tine displacements as a function of a modal force excitation corresponding to the first mode of the tine in the absence of a fiber. These models are used to evaluate the effect of changes in both length and diameter of the attached fibers. Theoretical values of the natural frequencies of different modes show an asymptotic relationship with the length and a linear relationship with the diameter of the attached fiber. Similar results are observed from experiment, one with a tungsten probe having an initial fiber length of 14.11 mm incrementally etched down to 0.83 mm, and another tungsten probe of length 8.16 mm incrementally etched in diameter, in both cases using chronocoulometry to determine incremental volumetric material removal. The lumped model is used to provide a frequency response again reveals poles and zeros that are consistent with experimental measurements. Finite element analysis shows mode shapes similar to experimental microscope observations of the resonating carbon probes. This model provides a means of interpreting measured responses in terms of the relative motion of the tine and attached fibers. Of particular relevance is that, when a “zero” is observed in the response of the tine, one mode of the fiber is matched to the tine frequency and is acting as an absorber. This represents an optimal condition for contact sensing and for transferring energy to the fiber for fluid mixing, touch sensing, and surface modification applications.« less

Theoretical and experimental study of the dynamic response of absorber-based, micro-scale, oscillatory probes for contact sensing applications.

PubMed

Kafashi, Sajad; Strayhorn, Ralph; Eldredge, Jeff D; Kelly, Scott D; Woody, Shane C; Smith, Stuart T

2016-06-01

This paper presents two models for predicting the frequency response of micro-scale oscillatory probes. These probes are manufactured by attaching a thin fiber to the free end of one tine of a quartz tuning fork oscillator. In these studies, the attached fibers were either 75 μm diameter tungsten or 7 μm diameter carbon with lengths ranging from around 1 to 15 mm. The oscillators used in these studies were commercial 32.7 kHz quartz tuning forks. The first theoretical model considers lateral vibration of two beams serially connected and provides a characteristic equation from which the roots (eigenvalues) are extracted to determine the natural frequencies of the probe. A second, lumped model approximation is used to derive an approximate frequency response function for prediction of tine displacements as a function of a modal force excitation corresponding to the first mode of the tine in the absence of a fiber. These models are used to evaluate the effect of changes in both length and diameter of the attached fibers. Theoretical values of the natural frequencies of different modes show an asymptotic relationship with the length and a linear relationship with the diameter of the attached fiber. Similar results are observed from experiment, one with a tungsten probe having an initial fiber length of 14.11 mm incrementally etched down to 0.83 mm, and another tungsten probe of length 8.16 mm incrementally etched in diameter, in both cases using chronocoulometry to determine incremental volumetric material removal. The lumped model is used to provide a frequency response again reveals poles and zeros that are consistent with experimental measurements. Finite element analysis shows mode shapes similar to experimental microscope observations of the resonating carbon probes. This model provides a means of interpreting measured responses in terms of the relative motion of the tine and attached fibers. Of particular relevance is that, when a "zero" is observed in the response of the tine, one mode of the fiber is matched to the tine frequency and is acting as an absorber. This represents an optimal condition for contact sensing and for transferring energy to the fiber for fluid mixing, touch sensing, and surface modification applications.

An ultrahigh-vacuum cryostat for simultaneous scanning tunneling microscopy and magneto-transport measurements down to 400 mK

NASA Astrophysics Data System (ADS)

Liebmann, Marcus; Bindel, Jan Raphael; Pezzotta, Mike; Becker, Stefan; Muckel, Florian; Johnsen, Tjorven; Saunus, Christian; Ast, Christian R.; Morgenstern, Markus

2017-12-01

We present the design and calibration measurements of a scanning tunneling microscope setup in a 3He ultrahigh-vacuum cryostat operating at 400 mK with a hold time of 10 days. With 2.70 m in height and 4.70 m free space needed for assembly, the cryostat fits in a one-story lab building. The microscope features optical access, an xy table, in situ tip and sample exchange, and enough contacts to facilitate atomic force microscopy in tuning fork operation and simultaneous magneto-transport measurements on the sample. Hence, it enables scanning tunneling spectroscopy on microstructured samples which are tuned into preselected transport regimes. A superconducting magnet provides a perpendicular field of up to 14 T. The vertical noise of the scanning tunneling microscope amounts to 1 pmrms within a 700 Hz bandwidth. Tunneling spectroscopy using one superconducting electrode revealed an energy resolution of 120 μeV. Data on tip-sample Josephson contacts yield an even smaller feature size of 60 μeV, implying that the system operates close to the physical noise limit.

An ultrahigh-vacuum cryostat for simultaneous scanning tunneling microscopy and magneto-transport measurements down to 400 mK.

PubMed

Liebmann, Marcus; Bindel, Jan Raphael; Pezzotta, Mike; Becker, Stefan; Muckel, Florian; Johnsen, Tjorven; Saunus, Christian; Ast, Christian R; Morgenstern, Markus

2017-12-01

We present the design and calibration measurements of a scanning tunneling microscope setup in a 3 He ultrahigh-vacuum cryostat operating at 400 mK with a hold time of 10 days. With 2.70 m in height and 4.70 m free space needed for assembly, the cryostat fits in a one-story lab building. The microscope features optical access, an xy table, in situ tip and sample exchange, and enough contacts to facilitate atomic force microscopy in tuning fork operation and simultaneous magneto-transport measurements on the sample. Hence, it enables scanning tunneling spectroscopy on microstructured samples which are tuned into preselected transport regimes. A superconducting magnet provides a perpendicular field of up to 14 T. The vertical noise of the scanning tunneling microscope amounts to 1 pm rms within a 700 Hz bandwidth. Tunneling spectroscopy using one superconducting electrode revealed an energy resolution of 120 μeV. Data on tip-sample Josephson contacts yield an even smaller feature size of 60 μeV, implying that the system operates close to the physical noise limit.

8. View of Clark Fork Vehicle Bridge facing southwest. Looking ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. View of Clark Fork Vehicle Bridge facing southwest. Looking at understructure of northernmost span. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

20. View of Clark Fork Vehicle Bridge facing up. Looking ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. View of Clark Fork Vehicle Bridge facing up. Looking at understructure of northernmost span. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

18. View of Clark Fork Vehicle Bridge facing north. Looking ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

18. View of Clark Fork Vehicle Bridge facing north. Looking at north concrete abutment and timber stringers. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

Mobile phone generated vibrations used to detect diabetic peripheral neuropathy.

PubMed

May, Jonathan David; Morris, Matthew William John

2017-12-01

In the current United Kingdom population the incidence of diabetic peripheral neuropathy is increasing. The presence of diabetic neuropathy affects decision making and treatment options. This study seeks to evaluate if the vibrations generated from a mobile phone can be used to screen patients for diabetic peripheral neuropathy. This study comprised of 61 patients; a control group of 21 patients; a lower limb injury group of 19 patients; a diabetic peripheral neuropathy group of 21 patients. The control and injury group were recruited randomly from fracture clinics. The diabetic peripheral neuropathy group were randomly recruited from the diabetic foot clinic. The 61 patients were examined using a 10g Semmes-Weinstein monofilament, a 128Hz tuning fork and a vibrating mobile phone. The points tested were, index finger, patella, lateral malleoli, medial malleoli, heel, first and fifth metatarsal heads. The most accurate location of all the clinical tests was the head of the 1st metatarsal at 0.86. The overall accuracy of the tuning fork was 0.77, the ten gram monofilament 0.79 and the mobile phone accuracy was 0.88. The control group felt 420 of 441 tests (95%). The injury group felt 349 of 399 tests (87%). The neuropathic group felt 216 of 441 tests (48%). There is a significant difference in the number of tests felt between the control and both the injury and neuropathic groups. p<0.0001 using N-1 Two Proportion Test. A mobile phone is an accurate screening tool for diabetic peripheral neuropathy. The most accurate location to test for diabetic peripheral neuropathy is the head of the 1st metatarsal. Screening for diabetic peripheral neuropathy in the index finger and patella were inaccurate. An injury to the lower limb affects the patient's vibration sensation, we would therefore recommend screening the contralateral limb to the injury. This study represents level II evidence of a new diagnostic investigation. Copyright © 2016 European Foot and Ankle Society. All rights reserved.

19. View of Clark Fork Vehicle Bridge facing north. Looking ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

19. View of Clark Fork Vehicle Bridge facing north. Looking at north abutment and underside of northernmost span. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

22. View of Clark Fork Vehicle Bridge facing downwest side. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

22. View of Clark Fork Vehicle Bridge facing down-west side. Looking at road deck and vertical laced channel. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

21. View of Clark Fork Vehicle Bridge facing west. Looking ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

21. View of Clark Fork Vehicle Bridge facing west. Looking at bridge deck, guard rail, juncture of two bridge spans. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

11. View of Clark Fork Vehicle Bridge facing northwest. Southernmost ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. View of Clark Fork Vehicle Bridge facing northwest. Southernmost span. Plaque was originally located where striped traffic sign is posted. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

Structural basis of the 3′-end recognition of a leading strand in stalled replication forks by PriA

PubMed Central

Sasaki, Kaori; Ose, Toyoyuki; Okamoto, Naoaki; Maenaka, Katsumi; Tanaka, Taku; Masai, Hisao; Saito, Mihoko; Shirai, Tsuyoshi; Kohda, Daisuke

2007-01-01

In eubacteria, PriA helicase detects the stalled DNA replication forks. This critical role of PriA is ascribed to its ability to bind to the 3′ end of a nascent leading DNA strand in the stalled replication forks. The crystal structures in complexes with oligonucleotides and the combination of fluorescence correlation spectroscopy and mutagenesis reveal that the N-terminal domain of PriA possesses a binding pocket for the 3′-terminal nucleotide residue of DNA. The interaction with the deoxyribose 3′-OH is essential for the 3′-terminal recognition. In contrast, the direct interaction with 3′-end nucleobase is unexpected, considering the same affinity for oligonucleotides carrying the four bases at the 3′ end. Thus, the N-terminal domain of PriA recognizes the 3′-end base in a base-non-selective manner, in addition to the deoxyribose and 5′-side phosphodiester group, of the 3′-terminal nucleotide to acquire both sufficient affinity and non-selectivity to find all of the stalled replication forks generated during DNA duplication. This unique feature is prerequisite for the proper positioning of the helicase domain of PriA on the unreplicated double-stranded DNA. PMID:17464287

Rad53 regulates replication fork restart after DNA damage in Saccharomyces cerevisiae

PubMed Central

Szyjka, Shawn J.; Aparicio, Jennifer G.; Viggiani, Christopher J.; Knott, Simon; Xu, Weihong; Tavaré, Simon; Aparicio, Oscar M.

2008-01-01

Replication fork stalling at a DNA lesion generates a damage signal that activates the Rad53 kinase, which plays a vital role in survival by stabilizing stalled replication forks. However, evidence that Rad53 directly modulates the activity of replication forks has been lacking, and the nature of fork stabilization has remained unclear. Recently, cells lacking the Psy2–Pph3 phosphatase were shown to be defective in dephosphorylation of Rad53 as well as replication fork restart after DNA damage, suggesting a mechanistic link between Rad53 deactivation and fork restart. To test this possibility we examined the progression of replication forks in methyl-methanesulfonate (MMS)-damaged cells, under different conditions of Rad53 activity. Hyperactivity of Rad53 in pph3Δ cells slows fork progression in MMS, whereas deactivation of Rad53, through expression of dominant-negative Rad53-KD, is sufficient to allow fork restart during recovery. Furthermore, combined deletion of PPH3 and PTC2, a second, unrelated Rad53 phosphatase, results in complete replication fork arrest and lethality in MMS, demonstrating that Rad53 deactivation is a key mechanism controlling fork restart. We propose a model for regulation of replication fork progression through damaged DNA involving a cycle of Rad53 activation and deactivation that coordinates replication restart with DNA repair. PMID:18628397

23. View of Clark Fork Vehicle Bridge facing upwest side. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

23. View of Clark Fork Vehicle Bridge facing up-west side. Looking at structural connection of top chord, vertical laced channel and diagonal bars. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

13. View of Clark Fork Vehicle Bridge facing south. Concrete ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. View of Clark Fork Vehicle Bridge facing south. Concrete barrier blocks access. Plaque was originally located where strioed traffic sign is posted at right. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

12. View of Clark Fork Vehicle Bridge facing south. Approach ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. View of Clark Fork Vehicle Bridge facing south. Approach from the north road. Plaque was originally located where striped traffic sign is posted. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

Fork rotation and DNA precatenation are restricted during DNA replication to prevent chromosomal instability.

PubMed

Schalbetter, Stephanie A; Mansoubi, Sahar; Chambers, Anna L; Downs, Jessica A; Baxter, Jonathan

2015-08-18

Faithful genome duplication and inheritance require the complete resolution of all intertwines within the parental DNA duplex. This is achieved by topoisomerase action ahead of the replication fork or by fork rotation and subsequent resolution of the DNA precatenation formed. Although fork rotation predominates at replication termination, in vitro studies have suggested that it also occurs frequently during elongation. However, the factors that influence fork rotation and how rotation and precatenation may influence other replication-associated processes are unknown. Here we analyze the causes and consequences of fork rotation in budding yeast. We find that fork rotation and precatenation preferentially occur in contexts that inhibit topoisomerase action ahead of the fork, including stable protein-DNA fragile sites and termination. However, generally, fork rotation and precatenation are actively inhibited by Timeless/Tof1 and Tipin/Csm3. In the absence of Tof1/Timeless, excessive fork rotation and precatenation cause extensive DNA damage following DNA replication. With Tof1, damage related to precatenation is focused on the fragile protein-DNA sites where fork rotation is induced. We conclude that although fork rotation and precatenation facilitate unwinding in hard-to-replicate contexts, they intrinsically disrupt normal chromosome duplication and are therefore restricted by Timeless/Tipin.

14. View of Clark Fork Vehicle Bridge facing north. Approach ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. View of Clark Fork Vehicle Bridge facing north. Approach from the south. Concrete barrier blocks access. Plaque was originally located where striped traffic sign is posted at right. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

40 CFR 131.33 - Idaho.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Creek, Doe Creek, Duck Creek, East Fork Holy Terror Creek, Fawn Creek, Flume Creek, Fly Creek, Forge... Terror Creek, J Fell Creek, Jacobs Ladder Creek, Lewis Creek, Liberty Creek, Lick Creek, Lime Creek... Creek, South Fork Chamberlain Creek, South Fork Holy Terror Creek, South Fork Norton Creek, South Fork...

40 CFR 131.33 - Idaho.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Creek, Doe Creek, Duck Creek, East Fork Holy Terror Creek, Fawn Creek, Flume Creek, Fly Creek, Forge... Terror Creek, J Fell Creek, Jacobs Ladder Creek, Lewis Creek, Liberty Creek, Lick Creek, Lime Creek... Creek, South Fork Chamberlain Creek, South Fork Holy Terror Creek, South Fork Norton Creek, South Fork...

40 CFR 131.33 - Idaho.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Creek, Doe Creek, Duck Creek, East Fork Holy Terror Creek, Fawn Creek, Flume Creek, Fly Creek, Forge... Terror Creek, J Fell Creek, Jacobs Ladder Creek, Lewis Creek, Liberty Creek, Lick Creek, Lime Creek... Creek, South Fork Chamberlain Creek, South Fork Holy Terror Creek, South Fork Norton Creek, South Fork...

40 CFR 131.33 - Idaho.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Creek, Doe Creek, Duck Creek, East Fork Holy Terror Creek, Fawn Creek, Flume Creek, Fly Creek, Forge... Terror Creek, J Fell Creek, Jacobs Ladder Creek, Lewis Creek, Liberty Creek, Lick Creek, Lime Creek... Creek, South Fork Chamberlain Creek, South Fork Holy Terror Creek, South Fork Norton Creek, South Fork...

40 CFR 131.33 - Idaho.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Creek, Doe Creek, Duck Creek, East Fork Holy Terror Creek, Fawn Creek, Flume Creek, Fly Creek, Forge... Terror Creek, J Fell Creek, Jacobs Ladder Creek, Lewis Creek, Liberty Creek, Lick Creek, Lime Creek... Creek, South Fork Chamberlain Creek, South Fork Holy Terror Creek, South Fork Norton Creek, South Fork...

Advancing the Fork detector for quantitative spent nuclear fuel verification

DOE PAGES

Vaccaro, S.; Gauld, I. C.; Hu, J.; ...

2018-01-31

The Fork detector is widely used by the safeguards inspectorate of the European Atomic Energy Community (EURATOM) and the International Atomic Energy Agency (IAEA) to verify spent nuclear fuel. Fork measurements are routinely performed for safeguards prior to dry storage cask loading. Additionally, spent fuel verification will be required at the facilities where encapsulation is performed for acceptance in the final repositories planned in Sweden and Finland. The use of the Fork detector as a quantitative instrument has not been prevalent due to the complexity of correlating the measured neutron and gamma ray signals with fuel inventories and operator declarations.more » A spent fuel data analysis module based on the ORIGEN burnup code was recently implemented to provide automated real-time analysis of Fork detector data. This module allows quantitative predictions of expected neutron count rates and gamma units as measured by the Fork detectors using safeguards declarations and available reactor operating data. This study describes field testing of the Fork data analysis module using data acquired from 339 assemblies measured during routine dry cask loading inspection campaigns in Europe. Assemblies include both uranium oxide and mixed-oxide fuel assemblies. More recent measurements of 50 spent fuel assemblies at the Swedish Central Interim Storage Facility for Spent Nuclear Fuel are also analyzed. An evaluation of uncertainties in the Fork measurement data is performed to quantify the ability of the data analysis module to verify operator declarations and to develop quantitative go/no-go criteria for safeguards verification measurements during cask loading or encapsulation operations. The goal of this approach is to provide safeguards inspectors with reliable real-time data analysis tools to rapidly identify discrepancies in operator declarations and to detect potential partial defects in spent fuel assemblies with improved reliability and minimal false positive alarms. Finally, the results are summarized, and sources and magnitudes of uncertainties are identified, and the impact of analysis uncertainties on the ability to confirm operator declarations is quantified.« less

Advancing the Fork detector for quantitative spent nuclear fuel verification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vaccaro, S.; Gauld, I. C.; Hu, J.

The Fork detector is widely used by the safeguards inspectorate of the European Atomic Energy Community (EURATOM) and the International Atomic Energy Agency (IAEA) to verify spent nuclear fuel. Fork measurements are routinely performed for safeguards prior to dry storage cask loading. Additionally, spent fuel verification will be required at the facilities where encapsulation is performed for acceptance in the final repositories planned in Sweden and Finland. The use of the Fork detector as a quantitative instrument has not been prevalent due to the complexity of correlating the measured neutron and gamma ray signals with fuel inventories and operator declarations.more » A spent fuel data analysis module based on the ORIGEN burnup code was recently implemented to provide automated real-time analysis of Fork detector data. This module allows quantitative predictions of expected neutron count rates and gamma units as measured by the Fork detectors using safeguards declarations and available reactor operating data. This study describes field testing of the Fork data analysis module using data acquired from 339 assemblies measured during routine dry cask loading inspection campaigns in Europe. Assemblies include both uranium oxide and mixed-oxide fuel assemblies. More recent measurements of 50 spent fuel assemblies at the Swedish Central Interim Storage Facility for Spent Nuclear Fuel are also analyzed. An evaluation of uncertainties in the Fork measurement data is performed to quantify the ability of the data analysis module to verify operator declarations and to develop quantitative go/no-go criteria for safeguards verification measurements during cask loading or encapsulation operations. The goal of this approach is to provide safeguards inspectors with reliable real-time data analysis tools to rapidly identify discrepancies in operator declarations and to detect potential partial defects in spent fuel assemblies with improved reliability and minimal false positive alarms. Finally, the results are summarized, and sources and magnitudes of uncertainties are identified, and the impact of analysis uncertainties on the ability to confirm operator declarations is quantified.« less

Advancing the Fork detector for quantitative spent nuclear fuel verification

NASA Astrophysics Data System (ADS)

Vaccaro, S.; Gauld, I. C.; Hu, J.; De Baere, P.; Peterson, J.; Schwalbach, P.; Smejkal, A.; Tomanin, A.; Sjöland, A.; Tobin, S.; Wiarda, D.

2018-04-01

The Fork detector is widely used by the safeguards inspectorate of the European Atomic Energy Community (EURATOM) and the International Atomic Energy Agency (IAEA) to verify spent nuclear fuel. Fork measurements are routinely performed for safeguards prior to dry storage cask loading. Additionally, spent fuel verification will be required at the facilities where encapsulation is performed for acceptance in the final repositories planned in Sweden and Finland. The use of the Fork detector as a quantitative instrument has not been prevalent due to the complexity of correlating the measured neutron and gamma ray signals with fuel inventories and operator declarations. A spent fuel data analysis module based on the ORIGEN burnup code was recently implemented to provide automated real-time analysis of Fork detector data. This module allows quantitative predictions of expected neutron count rates and gamma units as measured by the Fork detectors using safeguards declarations and available reactor operating data. This paper describes field testing of the Fork data analysis module using data acquired from 339 assemblies measured during routine dry cask loading inspection campaigns in Europe. Assemblies include both uranium oxide and mixed-oxide fuel assemblies. More recent measurements of 50 spent fuel assemblies at the Swedish Central Interim Storage Facility for Spent Nuclear Fuel are also analyzed. An evaluation of uncertainties in the Fork measurement data is performed to quantify the ability of the data analysis module to verify operator declarations and to develop quantitative go/no-go criteria for safeguards verification measurements during cask loading or encapsulation operations. The goal of this approach is to provide safeguards inspectors with reliable real-time data analysis tools to rapidly identify discrepancies in operator declarations and to detect potential partial defects in spent fuel assemblies with improved reliability and minimal false positive alarms. The results are summarized, and sources and magnitudes of uncertainties are identified, and the impact of analysis uncertainties on the ability to confirm operator declarations is quantified.

Assessment of possible sources of microbiological contamination in the water column and streambed sediment of the Jacks Fork, Ozark National Scenic Riverways, Missouri - Phase III

USGS Publications Warehouse

Davis, Jerri V.; Barr, Miya N.

2006-01-01

In 1998, a 5 river-mile reach of the Jacks Fork was included on Missouri's list of impaired waters as required by Section 303(d) of the Federal Clean Water Act. The identified pollutant on the Jacks Fork was fecal coliform bacteria. The length of the impaired reach was changed to 7 miles on the Missouri 2002 303(d) list because of data indicating the fecal coliform bacteria problem existed over a broader area. The U.S. Geological Survey, in cooperation with the National Park Service, conducted a study to better understand the extent and sources of microbiological contamination within the Jacks Fork from Alley Spring to the mouth, which includes the 7-mile 303(d) reach. Ten sites were sampled from June 2003 through October 2003 and from June 2004 through October 2004. Water-column and streambed sediment samples were collected from main-stem and tributary sites mostly during base-flow conditions during a variety of recreational season river uses and analyzed for fecal coliform and Escherichia coli bacteria. Isolates of Escherichia coli obtained from water samples collected at five sites were submitted for rep-PCR analysis to identify presumptive sources of fecal indicator bacteria in the Jacks Fork. Results indicate that recreational users (including boaters and swimmers) are not the primary source of fecal coliform bacteria in the Jacks Fork; rather, the presence of fecal coliform bacteria is associated with other animals, of which horses are the primary source. Increases in fecal coliform bacteria densities in the Jacks Fork are associated with cross-country horseback trail-riding events.

Endonuclease EEPD1 Is a Gatekeeper for Repair of Stressed Replication Forks*

PubMed Central

Kim, Hyun-Suk; Nickoloff, Jac A.; Wu, Yuehan; Williamson, Elizabeth A.; Sidhu, Gurjit Singh; Reinert, Brian L.; Jaiswal, Aruna S.; Srinivasan, Gayathri; Patel, Bhavita; Kong, Kimi; Burma, Sandeep; Lee, Suk-Hee; Hromas, Robert A.

2017-01-01

Replication is not as continuous as once thought, with DNA damage frequently stalling replication forks. Aberrant repair of stressed replication forks can result in cell death or genome instability and resulting transformation to malignancy. Stressed replication forks are most commonly repaired via homologous recombination (HR), which begins with 5′ end resection, mediated by exonuclease complexes, one of which contains Exo1. However, Exo1 requires free 5′-DNA ends upon which to act, and these are not commonly present in non-reversed stalled replication forks. To generate a free 5′ end, stalled replication forks must therefore be cleaved. Although several candidate endonucleases have been implicated in cleavage of stalled replication forks to permit end resection, the identity of such an endonuclease remains elusive. Here we show that the 5′-endonuclease EEPD1 cleaves replication forks at the junction between the lagging parental strand and the unreplicated DNA parental double strands. This cleavage creates the structure that Exo1 requires for 5′ end resection and HR initiation. We observed that EEPD1 and Exo1 interact constitutively, and Exo1 repairs stalled replication forks poorly without EEPD1. Thus, EEPD1 performs a gatekeeper function for replication fork repair by mediating the fork cleavage that permits initiation of HR-mediated repair and restart of stressed forks. PMID:28049724

24. View of one of the plaques from Clark Fork ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

24. View of one of the plaques from Clark Fork Vehicle Bridge. Presently located at the Bonner County Historical Museum in Sandpoint, Idaho. A plaque was attached at each end of the bridge. Only one remains. - Clark Fork Vehicle Bridge, Spanning Clark Fork River, serves Highway 200, Clark Fork, Bonner County, ID

77 FR 76420 - Final Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-28

... Fort Gay, confluence. Unincorporated Areas of Wayne County. At the Tug Fork +575 confluence. Mill Creek (backwater effects from From the Tug Fork +575 Town of Fort Gay. Tug Fork). confluence to approximately 1.1 miles upstream of the Tug Fork confluence. Tug Fork At the Big Sandy River +575 Town of Fort Gay...

11. Turbine Pit and Shaft of Unit 1, view to ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. Turbine Pit and Shaft of Unit 1, view to the south, with operating ring at base of shaft and servo motor arms in foreground and in left background recess. Turbine monitoring and auxiliary equipment is located in the rightbackground recess. - Washington Water Power Clark Fork River Noxon Rapids Hydroelectric Development, Powerhouse, South bank of Clark Fork River at Noxon Rapids, Noxon, Sanders County, MT

Both DNA Polymerases δ and ε Contact Active and Stalled Replication Forks Differently

PubMed Central

Yu, Chuanhe; Gan, Haiyun

2017-01-01

ABSTRACT Three DNA polymerases, polymerases α, δ, and ε (Pol α, Pol δ, and Pol ε), are responsible for eukaryotic genome duplication. When DNA replication stress is encountered, DNA synthesis stalls until the stress is ameliorated. However, it is not known whether there is a difference in the association of each polymerase with active and stalled replication forks. Here, we show that each DNA polymerase has a distinct pattern of association with active and stalled replication forks. Pol α is enriched at extending Okazaki fragments of active and stalled forks. In contrast, although Pol δ contacts the nascent lagging strands of active and stalled forks, it binds to only the matured (and not elongating) Okazaki fragments of stalled forks. Pol ε has greater contact with the nascent single-stranded DNA (ssDNA) of the leading strand on active forks than on stalled forks. We propose that the configuration of DNA polymerases at stalled forks facilitates the resumption of DNA synthesis after stress removal. PMID:28784720

The fecundity of fork-tailed threadfin bream (Nemipterus furcosus) in Bangka, Bangka Belitung

NASA Astrophysics Data System (ADS)

Utami, E.; Safitriyani, E.; Gatra Persada, Leo

2018-04-01

Fork-tailed threadfin bream (Nemipterus furcosus) is one of important economic fishes in Bangka. The sustainability of fork-tailed threadfin bream is threatened by degradation of natural habitat. Information of reproductive is needed for further management. The objective of this study was to examine fecundity of fork-tailed threadfin bream. The mean values of temperature was 28.83 ± 0,37°C, respectively. Sex ratio during sampling showed that female fork-tailed threadfin bream greater than male population. Berried female fork-tailed threadfin bream found from March until November. The greatest number of berried female fork-tailed threadfin bream showed in July with berried female value of 25. Fork-tailed threadfin bream fecundity was 19951 and 66628, respectively. The fecundity data can be used to access the reproductive potential of fish stock and also as an assessment on stock size of their natural population.

Termination of DNA replication forks: "Breaking up is hard to do".

PubMed

Bailey, Rachael; Priego Moreno, Sara; Gambus, Agnieszka

2015-01-01

To ensure duplication of the entire genome, eukaryotic DNA replication initiates from thousands of replication origins. The replication forks move through the chromatin until they encounter forks from neighboring origins. During replication fork termination forks converge, the replisomes disassemble and topoisomerase II resolves the daughter DNA molecules. If not resolved efficiently, terminating forks result in genomic instability through the formation of pathogenic structures. Our recent findings shed light onto the mechanism of replisome disassembly upon replication fork termination. We have shown that termination-specific polyubiquitylation of the replicative helicase component - Mcm7, leads to dissolution of the active helicase in a process dependent on the p97/VCP/Cdc48 segregase. The inhibition of terminating helicase disassembly resulted in a replication termination defect. In this extended view we present hypothetical models of replication fork termination and discuss remaining and emerging questions in the DNA replication termination field.

Sortal Concepts and Pragmatic Inference in Children's Early Quantification of Objects

ERIC Educational Resources Information Center

Srinivasan, Mahesh; Chestnut, Eleanor; Li, Peggy; Barner, David

2013-01-01

It is typically assumed that count nouns like "fork" act as logical sortals, specifying whether objects are countable units of a kind (e.g., that a whole fork counts as "one fork") or not (e.g., that a piece of a fork does not count as "one fork"). In four experiments, we provide evidence from linguistic and conceptual development that nouns do…

11. Photocopy of photograph (original copy in Edison collection). Photographer ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. Photocopy of photograph (original copy in Edison collection). Photographer and date unknown, although photo taken prior to 1930 reconstruction of Project flumes. VIEW OF ORIGINAL SOUTH FORK OF THE TULE RIVER MIDDLE FORK "BOX" WOOD FLUME BRANCH SHOWING NORTH FORK OF TULE RIVER MIDDLE FORK CROSSING. VIEW TO NORTHWEST. - Tule River Hydroelectric Project, Water Conveyance System, Middle Fork Tule River, Springville, Tulare County, CA

Grand Forks/East Grand Forks ITS strategy plan

DOT National Transportation Integrated Search

2001-01-15

The Grand Forks/East Grand Forks (GF/EGF) Area's Intelligent Transportation Systems (ITS) Strategy Plan is an effort by the GF/EGF Metropolitan Planning Organization (MPO) and its partners to develop a plan for deploying Intelligent Transportation Sy...

77 FR 39675 - Wallowa-Whitman National Forest, Baker County, OR; North Fork Burnt River Mining

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-05

...-Whitman National Forest, Baker County, OR; North Fork Burnt River Mining AGENCY: Forest Service, USDA... North Fork Burnt River Mining Record of Decision will replace and supercede the 2004 North Fork Burnt...

Replication stress-induced chromosome breakage is correlated with replication fork progression and is preceded by single-stranded DNA formation.

PubMed

Feng, Wenyi; Di Rienzi, Sara C; Raghuraman, M K; Brewer, Bonita J

2011-10-01

Chromosome breakage as a result of replication stress has been hypothesized to be the direct consequence of defective replication fork progression, or "collapsed" replication forks. However, direct and genome-wide evidence that collapsed replication forks give rise to chromosome breakage is still lacking. Previously we showed that a yeast replication checkpoint mutant mec1-1, after transient exposure to replication impediment imposed by hydroxyurea (HU), failed to complete DNA replication, accumulated single-stranded DNA (ssDNA) at the replication forks, and fragmented its chromosomes. In this study, by following replication fork progression genome-wide via ssDNA detection and by direct mapping of chromosome breakage after HU exposure, we have tested the hypothesis that the chromosome breakage in mec1 cells occurs at collapsed replication forks. We demonstrate that sites of chromosome breakage indeed correlate with replication fork locations. Moreover, ssDNA can be detected prior to chromosome breakage, suggesting that ssDNA accumulation is the common precursor to double strand breaks at collapsed replication forks.

General perspective view of the North Fork Butter Creek Bridge, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General perspective view of the North Fork Butter Creek Bridge, view looking southwest - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

Approach view of the North Fork Butter Creek Bridge, view ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Approach view of the North Fork Butter Creek Bridge, view looking south - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

General perspective view of the North Fork Butter Creek Bridge, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General perspective view of the North Fork Butter Creek Bridge, view looking north - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

Elevation view of the North Fork Butter Creek Bridge, view ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Elevation view of the North Fork Butter Creek Bridge, view looking west - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

Approach view of the North Fork Butter Creek Bridge, view ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Approach view of the North Fork Butter Creek Bridge, view looking north - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

Detail perspective view of the North Fork Butter Creek Bridge, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Detail perspective view of the North Fork Butter Creek Bridge, view looking southwest - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

General perspective view of the North Fork Butter Creek Bridge, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

General perspective view of the North Fork Butter Creek Bridge, view looking south - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

THE FORK AND THE KINASE: A DNA REPLICATION TALE FROM A CHK1 PERSPECTIVE

PubMed Central

González Besteiro, Marina A.; Gottifredi, Vanesa

2014-01-01

Replication fork progression is being continuously hampered by exogenously introduced and naturally occurring DNA lesions and other physical obstacles. The checkpoint kinase 1 (Chk1) is activated at replication forks that encounter damaged-DNA. Chk1 inhibits the initiation of new replication factories and stimulates the firing of dormant origins (those in the vicinity of stalled forks). Chk1 also avoids fork collapse into DSBs (double strand breaks) and promotes fork elongation. At the molecular level, the current model considers stalled forks as the site of Chk1 activation and the nucleoplasm as the location where Chk1 phosphorylates target proteins. This model certainly serves to explain how Chk1 modulates origin firing, but how Chk1 controls the fate of stalled forks is less clear. Interestingly, recent reports demonstrating that Chk1 phosphorylates chromatin-bound proteins and even holds kinase-independent functions might shed light on how Chk1 contributes to the elongation of damaged DNA. Such findings unveil a puzzling connection between Chk1 and DNA-lesion bypass, which might be central to promoting fork elongation and checkpoint attenuation. In summary, the multifaceted and versatile functions of Chk1 at ongoing forks and replication origins determine the extent and quality of the cellular response to replication stress. PMID:25795119

Assessment of hand-transmitted vibration exposure from motorized forks used for beach-cleaning operations.

PubMed

McDowell, Thomas W; Welcome, Daniel E; Warren, Christopher; Xu, Xueyan S; Dong, Ren G

2013-01-01

Motorized vibrating manure forks were used in beach-cleaning operations following the massive Deepwater Horizon oil spill in the Gulf of Mexico during the summer of 2010. The objectives of this study were to characterize the vibration emissions of these motorized forks and to provide a first approximation of hand-transmitted vibration exposures to workers using these forks for beach cleaning. Eight operators were recruited to operate the motorized forks during this laboratory study. Four fork configurations were used in the study; two motor speeds and two fork basket options were evaluated. Accelerations were measured near each hand as the operators completed the simulated beach-cleaning task. The dominant vibration frequency for these tools was identified to be around 20 Hz. Because acceleration was found to increase with motor speed, workers should consider operating these tools with just enough speed to get the job done. These forks exhibited considerable acceleration magnitudes when unloaded. The study results suggest that the motor should not be operated with the fork in the unloaded state. Anti-vibration gloves are not effective at attenuating the vibration frequencies produced by these forks, and they may even amplify the transmitted vibration and increase hand/arm fatigue. While regular work gloves are suitable, vibration-reducing gloves may not be appropriate for use with these tools. These considerations may also be generally applicable for the use of motorized forks in other workplace environments.

TT-Cut Torsional Quartz Crystal Resonators of Free-Free Bar-Type

NASA Astrophysics Data System (ADS)

Kawashima, Hirofumi; Nakazato, Mitsuhiro

1994-05-01

This paper describes a TT-cut torsional quartz crystal resonator of free-free bar type. An object of this paper is to clarify the frequency temperature behavior, series resistance and a quality factor for TT-cut torsional quartz crystal resonators of free-free bar-type. The analysis results are then compared with the measured data. The principal results indicate that the calculated values of frequency temperature behavior for resonators of free-free bar-type agree comparatively well with the measured ones. Similar to the torsional resonators of tuning fork-type, a torsional quartz crystal resonator of free-free bar-type is also found to have an absolute value of the second order temperature coefficient β smaller than half a value of that for a flexural mode quartz crystal resonator.

Enhanced sensitivity of a microfabricated resonator using a graphene-polystyrene bilayer membrane

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yun, Minhyuk; Lee, Eunho; Cho, Kilwon

2014-08-18

A graphene layer was synthesized using chemical vapor deposition methods and a polystyrene solution was spin-cast onto the graphene film. The graphene-polystyrene bilayer membrane was attached between the two tines of a microfabricated quartz tuning fork (QTF). The modulus of the graphene-polystyrene bilayer was measured to be twice that of a pristine polystyrene membrane. Exposure of the membrane-coated QTF to ethanol vapor decreased the resonance frequency of the microresonator. The bilayer membrane-coated QTF produced a frequency change that was three times the change obtained using a polystyrene membrane-coated QTF, with a lower degree of degradation in the Q factor. Themore » limit of detection of the bilayer membrane-coated QTF to ethanol vapor was determined to be 20 ppm.« less

Coarse-grained modelling of triglyceride crystallisation: a molecular insight into tripalmitin tristearin binary mixtures by molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Pizzirusso, Antonio; Brasiello, Antonio; De Nicola, Antonio; Marangoni, Alejandro G.; Milano, Giuseppe

2015-12-01

The first simulation study of the crystallisation of a binary mixture of triglycerides using molecular dynamics simulations is reported. Coarse-grained models of tristearin (SSS) and tripalmitin (PPP) molecules have been considered. The models have been preliminarily tested in the crystallisation of pure SSS and PPP systems. Two different quenching procedures have been tested and their performances have been analysed. The structures obtained from the crystallisation procedures show a high orientation order and a high content of molecules in the tuning fork conformation, comparable with the crystalline α phase. The behaviour of melting temperatures for the α phase of the mixture SSS/PPP obtained from the simulations is in qualitative agreement with the behaviour that was experimentally determined.

Topographic view of the North Fork Butter Creek Bridge (located ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Topographic view of the North Fork Butter Creek Bridge (located center of frame), view looking west - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

RFWD3-Dependent Ubiquitination of RPA Regulates Repair at Stalled Replication Forks.

PubMed

Elia, Andrew E H; Wang, David C; Willis, Nicholas A; Boardman, Alexander P; Hajdu, Ildiko; Adeyemi, Richard O; Lowry, Elizabeth; Gygi, Steven P; Scully, Ralph; Elledge, Stephen J

2015-10-15

We have used quantitative proteomics to profile ubiquitination in the DNA damage response (DDR). We demonstrate that RPA, which functions as a protein scaffold in the replication stress response, is multiply ubiquitinated upon replication fork stalling. Ubiquitination of RPA occurs on chromatin, involves sites outside its DNA binding channel, does not cause proteasomal degradation, and increases under conditions of fork collapse, suggesting a role in repair at stalled forks. We demonstrate that the E3 ligase RFWD3 mediates RPA ubiquitination. RFWD3 is necessary for replication fork restart, normal repair kinetics during replication stress, and homologous recombination (HR) at stalled replication forks. Mutational analysis suggests that multisite ubiquitination of the entire RPA complex is responsible for repair at stalled forks. Multisite protein group sumoylation is known to promote HR in yeast. Our findings reveal a similar requirement for multisite protein group ubiquitination during HR at stalled forks in mammalian cells. Copyright © 2015 Elsevier Inc. All rights reserved.

Water Quality and Biological Characteristics of the Middle Fork of the Saline River, Arkansas, 2003-06

USGS Publications Warehouse

Galloway, Joel M.; Petersen, James C.; Shelby, Erica L.; Wise, Jim A.

2008-01-01

The Middle Fork of the Saline River has many qualities that have been recognized by State and Federal agencies. The Middle Fork provides habitat for several rare aquatic species and is part of a larger stream system (the Upper Saline River) that is known for relatively high levels of species richness and relatively high numbers of species of concern. Water-quality samples were collected and streamflow was measured by the U.S. Geological Survey at three sites in the Middle Fork Basin between October 2003 and October 2006. The Arkansas Department of Environmental Quality collected discrete synoptic water-quality samples from eight sites between January 2004 and October 2006. The Arkansas Department of Environmental Quality also sampled fish (September-October 2003) and benthic macroinvertebrate communities (September 2003-December 2005) at five sites. Streamflow varied annually among the three streamflow sites from October 2003 to October 2006. The mean annual streamflow for Brushy Creek near Jessieville (MFS06) was 0.72 cubic meters per second for water years 2004-2006. The Middle Fork below Jessieville (MFS05) had a mean annual streamflow of 1.11 cubic meters per second for water years 2004-2006. The Middle Fork near Owensville (MFS02), the most downstream site, had a mean annual streamflow of 3.01 cubic meters per second. The greatest streamflows at the three sites generally occurred in the winter and spring and the least in the summer. Nutrient dynamics in the Middle Fork are controlled by activities in the basin and processes that occur in the stream. Point sources and nonpoint sources of nutrients occur in the Middle Fork Basin that could affect the water-quality. Nitrogen and phosphorus concentrations generally were greatest in Mill Creek (MFS04E) and in the Middle Fork immediately downstream from the confluence with Mill Creek (MFS04) with decreasing concentrations at sites farther downstream in Middle Fork. The site in Mill Creek is located downstream from a wastewater-treatment plant discharge and concentrations at sites farther downstream probably had lesser concentrations because of dilution effects and from algal uptake. Nutrient concentrations generally were significantly greater during high-flow conditions compared to base-flow conditions. Flow-weighted nutrient concentrations were computed for the three streamflow sites and were compared to 82 relatively undeveloped sites identified across the Nation, to the Alum Fork of the Saline River near Reform, Arkansas, and to the Illinois River south of Siloam Springs, Arkansas, a site influenced by numerous point and nonpoint sources of nutrients. Annual flow-weighted nutrient concentrations for MFS06, MFS05, and MFS02 were greater than relatively undeveloped sites, but were substantially less than the Illinois River south of Siloam Springs. Fecal indicator bacteria concentrations were slightly greater at MFS06 and MFS05 compared to concentrations at MFS02 for October 2003 to October 2006. MFS05 had the greatest E.coli concentrations and MFS06 had the greatest fecal coliform concentrations. Overall, fecal indicator bacteria concentrations were significantly greater for samples collected during high-flow conditions compared to samples collected during low-flow conditions at all three sites. Suspended-sediment concentrations did not vary significantly among MFS06, MFS05, and MFS02 for all the samples collected from October 2003 to October 2006. Suspended-sediment concentrations were significantly greater in samples collected during high-flow conditions compared to samples collected during base-flow conditions. Synoptic samples indicated varied total suspended-solids distributions from upstream to downstream in the Middle Fork between January 2004 and October 2006. Overall, total suspended-solids values were the greatest at site MFS02 and decreased at sites upstream and downstream. Turbidity measured when water-quality samples were

Feasibility and safety of modified inverted T-shaped method using linear stapler with movable cartridge fork for esophagojejunostomy following laparoscopic total gastrectomy.

PubMed

Ohuchida, Kenoki; Nagai, Eishi; Moriyama, Taiki; Shindo, Koji; Manabe, Tatsuya; Ohtsuka, Takao; Shimizu, Shuji; Nakamura, Masafumi

2017-01-01

We previously reported the use of an inverted T-shaped method to obtain a suitable view for hand sewing to close the common entry hole when the linear stapler was fired for esophagojejunostomy after laparoscopic total gastrectomy (LTG). This conventional method involved insertion of the fixed cartridge fork to the Roux limb and the fine movable anvil fork to the esophagus to avoid perforation of the jejunum. However, insertion of the movable anvil fork to the esophagus during this procedure often requires us to strongly push down the main body of the stapler with the fixed cartridge fork to bring the direction of the anvil fork in line with the direction of the long axis of the esophagus while controlling the opening of the movable anvil fork. We therefore modified this complicated inverted T-shaped method using a linear stapler with a movable cartridge fork. This modified method involved insertion of the movable cartridge fork into the Roux limb followed by natural, easy insertion of the fixed anvil fork into the esophagus without controlling the opening of the movable cartridge fork. We performed LTG in a total of 155 consecutive patients with gastric cancer from November 2007 to December 2015 in Kyushu University Hospital. After LTG, we performed the conventional inverted T-shaped method using a linear stapler with a fixed cartridge fork in 61 patients from November 2007 to July 2011 (fixed cartridge group). From August 2011, we used a linear stapler with a movable cartridge fork and performed the modified inverted T-shaped method in 94 patients (movable cartridge group). We herein compare the short-term outcomes in 94 cases of LTG using the modified method (movable cartridge fork) with those in 61 cases using the conventional method (fixed cartridge fork). We found no significant differences in the perioperative or postoperative events between the movable and fixed cartridge groups. One case of anastomotic leakage occurred in the fixed cartridge group, but no anastomotic leakage occurred in the movable cartridge group. Although there were no remarkable differences in the short-term outcomes between the movable and fixed cartridge groups, we believe that the modified inverted T-shaped method is technically more feasible and reliable than the conventional method and will contribute to the improved safety of LTG.

Feasibility and safety of modified inverted T-shaped method using linear stapler with movable cartridge fork for esophagojejunostomy following laparoscopic total gastrectomy

PubMed Central

Ohuchida, Kenoki; Moriyama, Taiki; Shindo, Koji; Manabe, Tatsuya; Ohtsuka, Takao; Shimizu, Shuji; Nakamura, Masafumi

2017-01-01

Background We previously reported the use of an inverted T-shaped method to obtain a suitable view for hand sewing to close the common entry hole when the linear stapler was fired for esophagojejunostomy after laparoscopic total gastrectomy (LTG). This conventional method involved insertion of the fixed cartridge fork to the Roux limb and the fine movable anvil fork to the esophagus to avoid perforation of the jejunum. However, insertion of the movable anvil fork to the esophagus during this procedure often requires us to strongly push down the main body of the stapler with the fixed cartridge fork to bring the direction of the anvil fork in line with the direction of the long axis of the esophagus while controlling the opening of the movable anvil fork. We therefore modified this complicated inverted T-shaped method using a linear stapler with a movable cartridge fork. This modified method involved insertion of the movable cartridge fork into the Roux limb followed by natural, easy insertion of the fixed anvil fork into the esophagus without controlling the opening of the movable cartridge fork. Methods We performed LTG in a total of 155 consecutive patients with gastric cancer from November 2007 to December 2015 in Kyushu University Hospital. After LTG, we performed the conventional inverted T-shaped method using a linear stapler with a fixed cartridge fork in 61 patients from November 2007 to July 2011 (fixed cartridge group). From August 2011, we used a linear stapler with a movable cartridge fork and performed the modified inverted T-shaped method in 94 patients (movable cartridge group). We herein compare the short-term outcomes in 94 cases of LTG using the modified method (movable cartridge fork) with those in 61 cases using the conventional method (fixed cartridge fork). Results We found no significant differences in the perioperative or postoperative events between the movable and fixed cartridge groups. One case of anastomotic leakage occurred in the fixed cartridge group, but no anastomotic leakage occurred in the movable cartridge group. Conclusions Although there were no remarkable differences in the short-term outcomes between the movable and fixed cartridge groups, we believe that the modified inverted T-shaped method is technically more feasible and reliable than the conventional method and will contribute to the improved safety of LTG. PMID:28616606

Assessment of undiscovered oil resources in the Bakken and Three Forks Formations, Williston Basin Province, Montana, North Dakota, and South Dakota, 2013

USGS Publications Warehouse

Gaswirth, Stephanie B.; Marra, Kristen R.; Cook, Troy A.; Charpentier, Ronald R.; Gautier, Donald L.; Higley, Debra K.; Klett, Timothy R.; Lewan, Michael D.; Lillis, Paul G.; Schenk, Christopher J.; Tennyson, Marilyn E.; Whidden, Katherine J.

2013-01-01

Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered volumes of 7.4 billion barrels of oil, 6.7 trillion cubic feet of associated/dissolved natural gas, and 0.53 billion barrels of natural gas liquids in the Bakken and Three Forks Formations in the Williston Basin Province of Montana, North Dakota, and South Dakota.

Gaussian Random Fields Methods for Fork-Join Network with Synchronization Constraints

DTIC Science & Technology

2014-12-22

substantial efforts were dedicated to the study of the max-plus recursions [21, 3, 12]. More recently, Atar et al. [2] have studied a fork-join...feedback and NES, Atar et al. [2] show that a dynamic priority discipline achieves throughput optimal- ity asymptotically in the conventional heavy...2011) Patient flow in hospitals: a data-based queueing-science perspective. Submitted to Stochastic Systems, 20. [2] R. Atar , A. Mandelbaum and A

The fork and the kinase: a DNA replication tale from a CHK1 perspective.

PubMed

González Besteiro, Marina A; Gottifredi, Vanesa

2015-01-01

Replication fork progression is being continuously hampered by exogenously introduced and naturally occurring DNA lesions and other physical obstacles. Checkpoint kinase 1 (Chk1) is activated at replication forks that encounter damaged DNA. Subsequently, Chk1 inhibits the initiation of new replication factories and stimulates the firing of dormant origins (those in the vicinity of stalled forks). Chk1 also avoids fork collapse into DSBs (double strand breaks) and promotes fork elongation. At the molecular level, the current model considers stalled forks as the site of Chk1 activation and the nucleoplasm as the location where Chk1 phosphorylates target proteins. This model certainly serves to explain how Chk1 modulates origin firing, but how Chk1 controls the fate of stalled forks is less clear. Interestingly, recent reports demonstrating that Chk1 phosphorylates chromatin-bound proteins and even holds kinase-independent functions might shed light on how Chk1 contributes to the elongation of damaged DNA. Indeed, such findings have unveiled a puzzling connection between Chk1 and DNA lesion bypass, which might be central to promoting fork elongation and checkpoint attenuation. In summary, Chk1 is a multifaceted and versatile signaling factor that acts at ongoing forks and replication origins to determine the extent and quality of the cellular response to replication stress. Copyright © 2014 Elsevier B.V. All rights reserved.

Two-dimensional resistivity investigation along West Fork Trinity River, Naval Air Station-Joint Reserve Base, Carswell Field, Fort Worth, Texas, October 2004

USGS Publications Warehouse

Shah, Sachin D.; Stanton, Gregory P.

2006-01-01

Naval Air Station-Joint Reserve Base Carswell Field (NAS-JRB) at Fort Worth, Tex., constitutes a government-owned, contractor-operated facility that has been in operation since 1942. Contaminants, primarily volatile organic compounds and metals, have entered the ground-water-flow system through leakage from waste-disposal sites and manufacturing processes. Ground water flows from west to east toward the West Fork Trinity River. During October 2004, the U.S. Geological Survey conducted a two-dimensional (2D) resistivity investigation at a site along the West Fork Trinity River at the eastern boundary of NAS-JRB to characterize the distribution of subsurface resistivity. Five 2D resistivity profiles were collected, which ranged from 500 to 750 feet long and extended to a depth of 25 feet. The Goodland Limestone and the underlying Walnut Formation form a confining unit that underlies the alluvial aquifer. The top of this confining unit is the top of bedrock at NAS-JRB. The bedrock confining unit is the zone of interest because of the potential for contaminated ground water to enter the West Fork Trinity River through saturated bedrock. The study involved a capacitively-coupled resistivity survey and inverse modeling to obtain true or actual resistivity from apparent resistivity. The apparent resistivity was processed using an inverse modeling software program. The results of this program were used to generate distributions (images) of actual resistivity referred to as inverted sections or profiles. The images along the five profiles show a wide range of resistivity values. The two profiles nearest the West Fork Trinity River generally showed less resistivity than the three other profiles.

36 CFR 292.62 - Valid existing rights.

Code of Federal Regulations, 2010 CFR

2010-07-01

... RECREATION AREAS Smith River National Recreation Area § 292.62 Valid existing rights. (a) Definition. For the... “wild” segments of the Wild and Scenic Smith River, Middle Fork Smith River, North Fork Smith River, Siskiyou Fork Smith River, South Fork Smith River, and their designated tributaries, except Peridotite...

DNA polymerase η modulates replication fork progression and DNA damage responses in platinum-treated human cells

NASA Astrophysics Data System (ADS)

Sokol, Anna M.; Cruet-Hennequart, Séverine; Pasero, Philippe; Carty, Michael P.

2013-11-01

Human cells lacking DNA polymerase η (polη) are sensitive to platinum-based cancer chemotherapeutic agents. Using DNA combing to directly investigate the role of polη in bypass of platinum-induced DNA lesions in vivo, we demonstrate that nascent DNA strands are up to 39% shorter in human cells lacking polη than in cells expressing polη. This provides the first direct evidence that polη modulates replication fork progression in vivo following cisplatin and carboplatin treatment. Severe replication inhibition in individual platinum-treated polη-deficient cells correlates with enhanced phosphorylation of the RPA2 subunit of replication protein A on serines 4 and 8, as determined using EdU labelling and immunofluorescence, consistent with formation of DNA strand breaks at arrested forks in the absence of polη. Polη-mediated bypass of platinum-induced DNA lesions may therefore represent one mechanism by which cancer cells can tolerate platinum-based chemotherapy.

Mutations in DONSON disrupt replication fork stability and cause microcephalic dwarfism

PubMed Central

Reynolds, John J; Bicknell, Louise S; Carroll, Paula; Higgs, Martin R; Shaheen, Ranad; Murray, Jennie E; Papadopoulos, Dimitrios K; Leitch, Andrea; Murina, Olga; Tarnauskaitė, Žygimantė; Wessel, Sarah R; Zlatanou, Anastasia; Vernet, Audrey; von Kriegsheim, Alex; Mottram, Rachel MA; Logan, Clare V; Bye, Hannah; Li, Yun; Brean, Alexander; Maddirevula, Sateesh; Challis, Rachel C; Skouloudaki, Kassiani; Almoisheer, Agaadir; Alsaif, Hessa S; Amar, Ariella; Prescott, Natalie J; Bober, Michael B; Duker, Angela; Faqeih, Eissa; Seidahmed, Mohammed Zain; Al Tala, Saeed; Alswaid, Abdulrahman; Ahmed, Saleem; Al-Aama, Jumana Yousuf; Altmüller, Janine; Al Balwi, Mohammed; Brady, Angela F; Chessa, Luciana; Cox, Helen; Fischetto, Rita; Heller, Raoul; Henderson, Bertram D; Hobson, Emma; Nürnberg, Peter; Percin, E Ferda; Peron, Angela; Spaccini, Luigina; Quigley, Alan J; Thakur, Seema; Wise, Carol A; Yoon, Grace; Alnemer, Maha; Tomancak, Pavel; Yigit, Gökhan; Taylor, A Malcolm R; Reijns, Martin AM; Simpson, Michael A; Cortez, David; Alkuraya, Fowzan S; Mathew, Christopher G; Jackson, Andrew P; Stewart, Grant S

2017-01-01

To ensure efficient genome duplication, cells have evolved numerous factors that promote unperturbed DNA replication, and protect, repair and restart damaged forks. Here we identify DONSON as a novel fork protection factor, and report biallelic DONSON mutations in 29 individuals with microcephalic dwarfism. We demonstrate that DONSON is a replisome component that stabilises forks during genome replication. Loss of DONSON leads to severe replication-associated DNA damage arising from nucleolytic cleavage of stalled replication forks. Furthermore, ATR-dependent signalling in response to replication stress is impaired in DONSON-deficient cells, resulting in decreased checkpoint activity, and potentiating chromosomal instability. Hypomorphic mutations substantially reduce DONSON protein levels and impair fork stability in patient cells, consistent with defective DNA replication underlying the disease phenotype. In summary, we identify mutations in DONSON as a common cause of microcephalic dwarfism, and establish DONSON as a critical replication fork protein required for mammalian DNA replication and genome stability. PMID:28191891

High-affinity DNA-binding Domains of Replication Protein A (RPA) Direct SMARCAL1-dependent Replication Fork Remodeling*

PubMed Central

Bhat, Kamakoti P.; Bétous, Rémy; Cortez, David

2015-01-01

SMARCAL1 catalyzes replication fork remodeling to maintain genome stability. It is recruited to replication forks via an interaction with replication protein A (RPA), the major ssDNA-binding protein in eukaryotic cells. In addition to directing its localization, RPA also activates SMARCAL1 on some fork substrates but inhibits it on others, thereby conferring substrate specificity to SMARCAL1 fork-remodeling reactions. We investigated the mechanism by which RPA regulates SMARCAL1. Our results indicate that although an interaction between SMARCAL1 and RPA is essential for SMARCAL1 activation, the location of the interacting surface on RPA is not. Counterintuitively, high-affinity DNA binding of RPA DNA-binding domain (DBD) A and DBD-B near the fork junction makes it easier for SMARCAL1 to remodel the fork, which requires removing RPA. We also found that RPA DBD-C and DBD-D are not required for SMARCAL1 regulation. Thus, the orientation of the high-affinity RPA DBDs at forks dictates SMARCAL1 substrate specificity. PMID:25552480

High-affinity DNA-binding domains of replication protein A (RPA) direct SMARCAL1-dependent replication fork remodeling.

PubMed

Bhat, Kamakoti P; Bétous, Rémy; Cortez, David

2015-02-13

SMARCAL1 catalyzes replication fork remodeling to maintain genome stability. It is recruited to replication forks via an interaction with replication protein A (RPA), the major ssDNA-binding protein in eukaryotic cells. In addition to directing its localization, RPA also activates SMARCAL1 on some fork substrates but inhibits it on others, thereby conferring substrate specificity to SMARCAL1 fork-remodeling reactions. We investigated the mechanism by which RPA regulates SMARCAL1. Our results indicate that although an interaction between SMARCAL1 and RPA is essential for SMARCAL1 activation, the location of the interacting surface on RPA is not. Counterintuitively, high-affinity DNA binding of RPA DNA-binding domain (DBD) A and DBD-B near the fork junction makes it easier for SMARCAL1 to remodel the fork, which requires removing RPA. We also found that RPA DBD-C and DBD-D are not required for SMARCAL1 regulation. Thus, the orientation of the high-affinity RPA DBDs at forks dictates SMARCAL1 substrate specificity. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

"Where Do We Turn? What Should We Do?" Processes To Help Educators and Their Students Recover from a Natural Disaster. A Monograph for the Plan for Social Excellence.

ERIC Educational Resources Information Center

Silverman, Robin L.

This book analyzes educators' reactions to the floods that destroyed the towns of Grand Forks and East Grand Forks in South Dakota. It is based on a planning grant that had four primary goals: (1) create a curriculum to help students understand their flood experience; (2) perform a child-observation study; (3) script and possibly produce a…

Recent sedimentation and surface-water flow patterns on the flood plain of the North Fork Forked Deer River, Dyer County, Tennessee

USGS Publications Warehouse

Wolfe, W.J.; Diehl, T.H.

1993-01-01

Sedimentation in the 19th and 20th centuries has had a major effect on surface-water drainage conditions along a 7-mile section of the North, Fork Forked Deer River flood plain, Dyer County, Tenn. During the century prior to 1930, 5 to 12 feet of sediment were deposited over much of the flood plain, resulting in channel obstruction and widespread flooding. The estimated bankfull capacity of the natural channel before it was channelized in 19 16 was comparable to the base flow of the river during the 1980's. Ditching of the river between 191i6 and 1;9,21 was followed by reductions in sedimentation rates over parts of the flood plain. However, the effects of sedimentation have persisted. Occlusions along the natural channel of the river have divided this stream reach into a series of sloughs. These sloughs continue to fill with sediment and are surrounded by ponds that have expanded since 1941. Degradation of the North Fork Forked Deer ditch may eventually reduce ponding over much of the flood plain. Active incision of headcuts in both banks of the ditch is enhancing the drainage of widespread ponded areas. These headcuts likely will have limited effect on drainage of most tributaries. The highest recent sedimentation rates, in places more than 0.2 foot per year, are concentrated near the flood-plain margin along tributary streams. In conjunction with beaver dams and debris, ongoing sedimentation has blocked flow in several tributaries, posing a flood hazard to agricultural land near the flood-plain margin. The occluded tributaries likely will continue to overflow unless they are periodically dredged or their sediment loads are reduced.

Channelization and floodplain forests: Impacts of accelerated sedimentation and valley plug formation on floodplain forests of the Middle Fork Forked Deer River, Tennessee, USA

USGS Publications Warehouse

Oswalt, S.N.; King, S.L.

2005-01-01

We evaluated the severe degradation of floodplain habitats resulting from channelization and concomitant excessive coarse sedimentation on the Middle Fork Forked Deer River in west Tennessee from 2000 to 2003. Land use practices have resulted in excessive sediment in the tributaries and river system eventually resulting in sand deposition on the floodplain, increased overbank flooding, a rise in the groundwater table, and ponding of upstream timber. Our objectives were to: (1) determine the composition of floodplain vegetation communities along the degraded river reach, (2) to isolate relationships among these communities, geomorphic features, and environmental variables and (3) evaluate successional changes based on current stand conditions. Vegetation communities were not specifically associated with predefined geomorphic features; nevertheless, hydrologic and geomorphic processes as a result of channelization have clearly affected vegetation communities. The presence of valley plugs and continued degradation of upstream reaches and tributaries on the impacted study reach has arrested recovery of floodplain plant communities. Historically common species like Liquidambar styraciflua L. and Quercus spp. L. were not important, with importance values (IV) less than 1, and occurred in less than 20% of forested plots, while Acer rubrum L., a disturbance-tolerant species, was the most important species on the site (IV = 78.1) and occurred in 87% of forested plots. The results of this study also indicate that channelization impacts on the Middle Fork Forked Deer River are more temporally and spatially complex than previously described for other river systems. Rehabilitation of this system necessitates a long-term, landscape-scale solution that addresses watershed rehabilitation in a spatially and temporally hierarchical manner. ?? 2005 Elsevier B.V. All rights reserved.

Runoff generation from neighboring headwater basins with differing glacier coverage using the distributed hydrological model WaSiM, Eklutna, Alaska

NASA Astrophysics Data System (ADS)

Ostman, J. S.; Loso, M.; Liljedahl, A. K.; Gaedeke, A.; Geck, J. E.

2017-12-01

Many Alaska glaciers are thinning and retreating, and glacier wastage is projected to affect runoff processes from glacierized basins. Accordingly, effective resource management in glacierized watersheds requires quantification of a glacier's role on streamflow generation. The Eklutna catchment (311 km2) supplies water and electricity for Anchorage, Alaska (pop. 300,000) via Eklutna Lake. The Eklutna headwaters include the West Fork (64 km2, 46% glacier), and the East Fork (101 km2, 12% glacier). Total average annual discharge (2009-2015) is similar from the West (42,100 m3) and East (42,200 m3) forks, while specific annual runoff from the West Fork (2940 mm) exceeds that of the East Fork (1500 mm). To better understand what controls runoff, we are simulating the Eklutna annual water budget using a distributed watershed-level hydrological model. We force the Water Flow and Balance Simulation Model (WaSiM) using continuous air temperature, precipitation, wind speed, shortwave incoming radiation, and relative humidity primarily measured in the West Fork basin. We use Eklutna Glacier snow accumulation and ablation to calibrate the snowmelt and glacier sub-modules. Melt season discharge from the West and East forks is used for runoff comparison. Preliminary results show 2013-2015 simulated glacier point balances (accumulation and melt) are within 15% of glacier stake observations. Runoff was effectively modeled in the West Fork (NSE=0.80), while being over-predicted in the East Fork , which we attribute to a lack of forcing data in the less-glacierized basin. The simulations suggest that 78% of West Fork total runoff is from glacier melt, compared with <40% in the East Fork where glacier runoff contribution is higher during low-snow years.

The NEIL1 G83D germline DNA glycosylase variant induces genomic instability and cellular transformation

PubMed Central

Galick, Heather A.; Marsden, Carolyn G.; Kathe, Scott; Dragon, Julie A.; Volk, Lindsay; Nemec, Antonia A.; Wallace, Susan S.; Prakash, Aishwarya; Doublié, Sylvie; Sweasy, Joann B.

2017-01-01

Base excision repair (BER) is a key genome maintenance pathway. The NEIL1 DNA glycosylase recognizes oxidized bases, and likely removes damage in advance of the replication fork. The rs5745906 SNP of the NEIL1 gene is a rare human germline variant that encodes the NEIL1 G83D protein, which is devoid of DNA glycosylase activity. Here we show that expression of G83D NEIL1 in MCF10A immortalized but non-transformed mammary epithelial cells leads to replication fork stress. Upon treatment with hydrogen peroxide, we observe increased levels of stalled replication forks in cells expressing G83D NEIL1 versus cells expressing the wild-type (WT) protein. Double-strand breaks (DSBs) arise in G83D-expressing cells during the S and G2/M phases of the cell cycle. Interestingly, these breaks result in genomic instability in the form of high levels of chromosomal aberrations and micronuclei. Cells expressing G83D also grow in an anchorage independent manner, suggesting that the genomic instability results in a carcinogenic phenotype. Our results are consistent with the idea that an inability to remove oxidative damage in an efficient manner at the replication fork leads to genomic instability and mutagenesis. We suggest that individuals who harbor the G83D NEIL1 variant face an increased risk for human cancer. PMID:29156764

Movement of bull trout in the upper Jarbidge River watershed, Idaho and Nevada, 2008-09--A supplement to Open-File Report 2010-1033

USGS Publications Warehouse

Munz, Carrie S.; Allen, M. Brady; Connolly, Patrick J.

2011-01-01

We monitored bull trout (Salvelinus confluentus) in 2008 and 2009 as a continuation of our work in 2006 and 2007, which involved the tagging of 1,536 bull trout with passive integrated transponder (PIT) tags in the East Fork Jarbidge River and West Fork Jarbidge River and their tributaries in northeastern Nevada and southern Idaho. We installed PIT tag interrogation systems (PTISs) at established locations soon after ice-out, and maintained the PTISs in order to collect information on bull trout movements through December of each year. We observed a marked increase of movement in 2008 and 2009. Bull trout tagged in the uppermost portions of the East Fork Jarbidge River at altitudes greater than 2,100 meters moved to the confluence of the East Fork Jarbidge River and West Fork Jarbidge River in summer and autumn. Ten bull trout tagged upstream of the confluence of Pine Creek and the West Fork Jarbidge River moved downstream and then upstream in the East Fork Jarbidge River, and then past the PTIS at Murphy Hot Springs (river kilometer [rkm] 4.1). Two of these fish ascended Dave Creek, a tributary of the East Fork Jarbidge River, past the PTIS at rkm 0.4. One bull trout that was tagged at rkm 11 in Dave Creek on June 28, 2007 moved downstream to the confluence of the East Fork Jarbidge River and West Fork Jarbidge River (rkm 0) on July 28, 2007, and it was then detected in the West Fork Jarbidge River moving past our PTIS at rkm 15 on May 4, 2008. Combined, the extent and types of bull trout movements observed indicated that the primarily age-1 and age-2 bull trout that we tagged in 2006 and 2007 showed increased movement with age and evidence of a substantial amount of fluvial life history. The movements suggest strong connectivity between spawning areas and downstream mainstem areas, as well as between the East Fork Jarbidge River and West Fork Jarbidge River.

Salmon Supplementation Studies in Idaho Rivers, 1999-2000 Progress Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kohler, Andy; Taki, Doug; Teton, Angelo

2001-11-01

As part of the Idaho Supplementation Studies, fisheries crews from the Shoshone-Bannock Tribes have been snorkeling tributaries of the Salmon River to estimate chinook salmon (Oncorhynchus tshawytscha) parr abundance; conducting surveys of spawning adult chinook salmon to determine the number of redds constructed and collect carcass information; operating a rotary screw trap on the East Fork Salmon River and West Fork Yankee Fork Salmon River to enumerate and PIT-tag emigrating juvenile chinook salmon; and collecting and PIT-tagging juvenile chinook salmon on tributaries of the Salmon River. The Tribes work in the following six tributaries of the Salmon River: Bear Valleymore » Creek, East Fork Salmon River, Herd Creek, South Fork Salmon River, Valley Creek, and West Fork Yankee Fork Salmon River. Snorkeling was used to obtain parr population estimates for ISS streams from 1992 to 1997. However, using the relatively vigorous methods described in the ISS experimental design to estimate summer chinook parr populations, results on a project-wide basis showed extraordinarily large confidence intervals and coefficients of variation. ISS cooperators modified their sampling design over a few years to reduce the variation around parr population estimates without success. Consequently, in 1998 snorkeling to obtain parr population estimates was discontinued and only General Parr Monitoring (GPM) sites are snorkeled. The number of redds observed in SBT-ISS streams has continued to decline as determined by five year cycles. Relatively weak strongholds continue to occur in the South Fork Salmon River and Bear Valley Creek. A rotary screw trap was operated on the West Fork Yankee Fork during the spring and fall of 1999 and the spring of 2000 to monitor juvenile chinook migration. A screw trap was also operated on the East Fork of the Salmon River during the spring and fall from 1993 to 1997 and 1999 (fall only) to 2000. Significant supplementation treatments have occurred in the South Fork Salmon River (IDFG). The East Fork Salmon River received supplementation treatments yearly through 1995. There have been no treatments since 1995, and no significant future treatments from local broodstock are conceivable due to extremely poor escapement. The West Fork Yankee Fork received a single presmolt treatment in 1994. Similarly, no significant future treatments are planned for the WFYF due to extremely poor escapement. However, small scale experimental captive rearing and broodstock techniques are currently being tested with populations from the EFSR and WFYF. Captive rearing/broodstock techniques could potentially provide feedback for evaluation of supplementation. The other three SBT-ISS streams are control streams and do not receive hatchery treatments.« less

27 CFR 9.113 - North Fork of Long Island.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false North Fork of Long Island... North Fork of Long Island. (a) Name. The name of the viticultural area described in this section is “North Fork of Long Island.” (b) Approved maps. The appropriate maps for determining the boundaries of...

27 CFR 9.113 - North Fork of Long Island.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false North Fork of Long Island... North Fork of Long Island. (a) Name. The name of the viticultural area described in this section is “North Fork of Long Island.” (b) Approved maps. The appropriate maps for determining the boundaries of...

27 CFR 9.113 - North Fork of Long Island.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false North Fork of Long Island... North Fork of Long Island. (a) Name. The name of the viticultural area described in this section is “North Fork of Long Island.” (b) Approved maps. The appropriate maps for determining the boundaries of...

Mouse embryonic stem cells have increased capacity for replication fork restart driven by the specific Filia-Floped protein complex.

PubMed

Zhao, Bo; Zhang, Weidao; Cun, Yixian; Li, Jingzheng; Liu, Yan; Gao, Jing; Zhu, Hongwen; Zhou, Hu; Zhang, Rugang; Zheng, Ping

2018-01-01

Pluripotent stem cells (PSCs) harbor constitutive DNA replication stress during their rapid proliferation and the consequent genome instability hampers their applications in regenerative medicine. It is therefore important to understand the regulatory mechanisms of replication stress response in PSCs. Here, we report that mouse embryonic stem cells (ESCs) are superior to differentiated cells in resolving replication stress. Specifically, ESCs utilize a unique Filia-Floped protein complex-dependent mechanism to efficiently promote the restart of stalled replication forks, therefore maintaining genomic stability. The ESC-specific Filia-Floped complex resides on replication forks under normal conditions. Replication stress stimulates their recruitment to stalling forks and the serine 151 residue of Filia is phosphorylated in an ATR-dependent manner. This modification enables the Filia-Floped complex to act as a functional scaffold, which then promotes the stalling fork restart through a dual mechanism: both enhancing recruitment of the replication fork restart protein, Blm, and stimulating ATR kinase activation. In the Blm pathway, the scaffolds recruit the E3 ubiquitin ligase, Trim25, to the stalled replication forks, and in turn Trim25 tethers and concentrates Blm at stalled replication forks through ubiquitination. In differentiated cells, the recruitment of the Trim25-Blm complex to replication forks and the activation of ATR signaling are much less robust due to lack of the ESC-specific Filia-Floped scaffold. Thus, our study reveals that ESCs utilize an additional and unique regulatory layer to efficiently promote the stalled fork restart and maintain genomic stability.

Effects of Transposable Elements on the Expression of the Forked Gene of Drosophila Melanogaster

PubMed Central

Hoover, K. K.; Chien, A. J.; Corces, V. G.

1993-01-01

The products of the forked gene are involved in the formation and/or maintenance of a temporary fibrillar structure within the developing bristle rudiment of Drosophila melanogaster. Mutations in the forked locus alter this structure and result in aberrant development of macrochaetae, microchaetae and trichomes. The locus has been characterized at the molecular level by walking, mutant characterization and transcript analysis. Expression of the six forked transcripts is temporally restricted to midlate pupal development. At this time, RNAs of 6.4, 5.6, 5.4, 2.5, 1.9 and 1.1 kilobases (kb) are detected by Northern analysis. The coding region of these RNAs has been found to be within a 21-kb stretch of genomic DNA. The amino terminus of the proteins encoded by the 5.4- and 5.6-kb forked transcripts contain tandem copies of ankyrin-like repeats that may play an important role in the function of forked-encoded products. The profile of forked RNA expression is altered in seven spontaneous mutations characterized during this study. Three forked mutations induced by the insertion of the gypsy retrotransposon contain a copy of this element inserted into an intron of the gene. In these mutants, the 5.6-, 5.4- and 2.5-kb forked mRNAs are truncated via recognition of the polyadenylation site in the 5' long terminal repeat of the gypsy retrotransposon. These results help explain the role of the forked gene in fly development and further our understanding of the role of transposable elements in mutagenesis. PMID:8244011

Sequence-stratigraphic controls on sandstone diagenesis: An example from the Williams Fork formation, Piceance Basin, Colorado

NASA Astrophysics Data System (ADS)

Aboktef, Adel

This study documents the distribution of diagenetic alterations in Williams Fork fluvial sandstones, assess sequence stratigraphic controls on diagenetic features, and addresses diagenetic impacts on porosity. Petrographic point counts of 220 thin sections from six wells forms the database. The near absence of potassium feldspar and volcanic rock fragments in the lower Williams Fork interval and increasing plagioclase content upward represent changes in sediment provenance rather than stratigraphic variability in diagenesis. The lower Williams Fork sands are from sedimentary sources whereas middle and upper Williams Fork sands include input from magmatic arcs and basement uplifts. Compaction, early and late cementation, dissolution, and replacement by calcite or clay minerals combined to alter Williams Fork sandstones. Infiltration of clays occurred prior to any burial. Chlorite, quartz, non-ferroan calcite, compaction and dissolution features, and kaolinite formed during eo-diagenesis at <70°C. More quartz, compaction and dissolution features, plus albite, illite, mixed-layer illite/smectite, ferroan calcite, and dolomite formed in the meso-diagenetic realm (>70°C). Four of these features show spatial variability with respect to systems tracts. Infiltrated clays are concentrated in lowstand systems tracts (LST) and highstand systems tracts (HST) because accommodation space rose slow or fell during deposition of those sands, which led to prolonged sand body exposure on floodplain and ample opportunities for downward percolation of mud during flood events. Concentration of pseudomatrix (mud intraclasts) in HST and LST deposits resulted from floodplain erosion when base-level fell with decreasing accommodation space. Authigenic chlorite formed in the HST and transgressive systems tracts (TST) of the upper half of the Williams Fork Formation because volcanic clasts are abundant in that interval. Quartz overgrowths are more likely to exceed 7% in TST deposits for reasons that are unknown. High total clay content (infiltrated, grain coatings, pseudomatrix) does inhibit quartz overgrowths in all systems tracts. Williams Fork sandstones form low-permeability tight-gas reservoirs. Primary porosity was almost entirely destroyed by compaction and cementation. Reservoir rock resulted from one of two pathways. Eogenetic authigenic chlorite and/or calcite inhibited quartz cementation, minimized compaction and protected some primary porosity. Alternately, dissolution of framework grains or cements created secondary porosity. The later pathway tends to be the more dominant.

Water quality of some logged and unlogged California streams

Treesearch

Fredric R. Kopperdahl; James W. Burns; Gary E. Smith

1971-01-01

Water quality was monitored in 1968 and 1969 in six coastal streams in northern California, four of which were subjected to logging and/or road building (Bummer Lake Creek, South Fork Yager Creek, Little North Fork Noyo River, and South Fork Caspar Creek), while the others remained undisturbed (Godwood Creek and North Fork Caspar Creek). The purposes of this study were...

Phosphorylated RPA recruits PALB2 to stalled DNA replication forks to facilitate fork recovery

PubMed Central

Murphy, Anar K.; Fitzgerald, Michael; Ro, Teresa; Kim, Jee Hyun; Rabinowitsch, Ariana I.; Chowdhury, Dipanjan; Schildkraut, Carl L.

2014-01-01

Phosphorylation of replication protein A (RPA) by Cdk2 and the checkpoint kinase ATR (ATM and Rad3 related) during replication fork stalling stabilizes the replisome, but how these modifications safeguard the fork is not understood. To address this question, we used single-molecule fiber analysis in cells expressing a phosphorylation-defective RPA2 subunit or lacking phosphatase activity toward RPA2. Deregulation of RPA phosphorylation reduced synthesis at forks both during replication stress and recovery from stress. The ability of phosphorylated RPA to stimulate fork recovery is mediated through the PALB2 tumor suppressor protein. RPA phosphorylation increased localization of PALB2 and BRCA2 to RPA-bound nuclear foci in cells experiencing replication stress. Phosphorylated RPA also stimulated recruitment of PALB2 to single-strand deoxyribonucleic acid (DNA) in a cell-free system. Expression of mutant RPA2 or loss of PALB2 expression led to significant DNA damage after replication stress, a defect accentuated by poly-ADP (adenosine diphosphate) ribose polymerase inhibitors. These data demonstrate that phosphorylated RPA recruits repair factors to stalled forks, thereby enhancing fork integrity during replication stress. PMID:25113031

Phosphorylated RPA recruits PALB2 to stalled DNA replication forks to facilitate fork recovery.

PubMed

Murphy, Anar K; Fitzgerald, Michael; Ro, Teresa; Kim, Jee Hyun; Rabinowitsch, Ariana I; Chowdhury, Dipanjan; Schildkraut, Carl L; Borowiec, James A

2014-08-18

Phosphorylation of replication protein A (RPA) by Cdk2 and the checkpoint kinase ATR (ATM and Rad3 related) during replication fork stalling stabilizes the replisome, but how these modifications safeguard the fork is not understood. To address this question, we used single-molecule fiber analysis in cells expressing a phosphorylation-defective RPA2 subunit or lacking phosphatase activity toward RPA2. Deregulation of RPA phosphorylation reduced synthesis at forks both during replication stress and recovery from stress. The ability of phosphorylated RPA to stimulate fork recovery is mediated through the PALB2 tumor suppressor protein. RPA phosphorylation increased localization of PALB2 and BRCA2 to RPA-bound nuclear foci in cells experiencing replication stress. Phosphorylated RPA also stimulated recruitment of PALB2 to single-strand deoxyribonucleic acid (DNA) in a cell-free system. Expression of mutant RPA2 or loss of PALB2 expression led to significant DNA damage after replication stress, a defect accentuated by poly-ADP (adenosine diphosphate) ribose polymerase inhibitors. These data demonstrate that phosphorylated RPA recruits repair factors to stalled forks, thereby enhancing fork integrity during replication stress. © 2014 Murphy et al.

Micro-Electromechanical Instrument and Systems Development at the Charles Stark Draper Laboratory

NASA Technical Reports Server (NTRS)

Connelly, J. H.; Gilmore, J. P.; Weinberg, M. S.

1995-01-01

Several generations of micromechanical gyros and accelerometers have been developed at Draper. Current design effort centers on tuning-fork gyro design and pendulous accelerometer configurations. Over 200 gyros of different generations have been packaged and tested. These units have successfully performed across a temperature range of -40 to 85 degrees C, and have survived 30,000-g shock tests along all axes. Draper is currently under contract to develop an integrated micro-mechanical inertial sensor assembly (MMISA) and global positioning system (GPS) receiver configuration. The ultimate projections for size, weight, and power for an MMISA, after electronic design of the application specific integrated circuit (ASIC ) is completed, are 2 x 2 x 0.5 cm, 5 gm, and less than 1 W, respectively. This paper describes the fabrication process, the current gyro and accelerometer designs, and system configurations.

Historical Experiments in Students' Hands: Unfragmenting Science through Action and History

NASA Astrophysics Data System (ADS)

Cavicchi, Elizabeth Mary

2008-08-01

Two students, meeting together with a teacher, redid historical experiments. Unlike conventional instruction where science topics and practices often fragment, they experienced interrelatedness among phenomena, participants’ actions, and history. This study narrates actions that fostered an interrelated view. One action involved opening up historical telephones to examine interior circuitry. Another made sound visible in a transparent air column filled with Styrofoam bits and through Lissajous figures produced by reflecting light off orthogonal nineteenth century tuning forks crafted by Koenig and Kohl. Another involved orienting magnetic compasses to reveal the magnetism of conducting wires, historically investigated by Oersted and Schweigger. Replicating Homberg’s triboluminescent compound elicited students’ reflective awareness of history. These actions bore pedagogical value in recovering some of the interrelatedness inherent in the history and reintroducing the wonder of science phenomena to students today.

Contact Dependence and Velocity Crossover in Friction between Microscopic Solid/Solid Contacts.

PubMed

McGraw, Joshua D; Niguès, Antoine; Chennevière, Alexis; Siria, Alessandro

2017-10-11

Friction at the nanoscale differs markedly from that between surfaces of macroscopic extent. Characteristically, the velocity dependence of friction between apparent solid/solid contacts can strongly deviate from the classically assumed velocity independence. Here, we show that a nondestructive friction between solid tips with radius on the scale of hundreds of nanometers and solid hydrophobic self-assembled monolayers has a strong velocity dependence. Specifically, using laterally oscillating quartz tuning forks, we observe a linear scaling in the velocity at the lowest accessed velocities, typically hundreds of micrometers per second, crossing over into a logarithmic velocity dependence. This crossover is consistent with a general multicontact friction model that includes thermally activated breaking of the contacts at subnanometric elongation. We find as well a strong dependence of the friction on the dimensions of the frictional probe.

Quartz-enhanced photoacoustic detection of ethylene using a 10.5 μm quantum cascade laser.

PubMed

Wang, Zhen; Li, Zhili; Ren, Wei

2016-02-22

A quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor has been developed for the sensitive detection of ethylene (C2H4) at 10.5 µm using a continuous-wave distributed-feedback quantum cascade laser. At this long-wavelength infrared, the key acoustic elements of quartz tuning fork and micro-resonators were optimized to improve the detection signal-to-noise ratio by a factor of >4. The sensor calibration demonstrated an excellent linear response (R2>0.999) to C2H4 concentration at the selected operating pressure of 500 and 760 Torr. With a minimum detection limit of 50 parts per billion (ppb) achieved at an averaging time of 70 s, the sensor has been deployed for measuring the C2H4 efflux during the respiration of biological samples in an agronomic environment.

MEMS sensing and control: an aerospace perspective

NASA Astrophysics Data System (ADS)

Schoess, Jeffrey N.; Arch, David K.; Yang, Wei; Cabuz, Cleopatra; Hocker, Ben; Johnson, Burgess R.; Wilson, Mark L.

2000-06-01

Future advanced fixed- and rotary-wing aircraft, launch vehicles, and spacecraft will incorporate smart microsensors to monitor flight integrity and provide flight control inputs. This paper provides an overview of Honeywell's MEMS technologies for aerospace applications of sensing and control. A unique second-generation polysilicon resonant microbeam sensor design is described. It incorporates a micron-level vacuum-encapsulated microbeam to optically sense aerodynamic parameters and to optically excite the sensor pick off: optically excited self-resonant microbeams form the basis for a new class of versatile, high- performance, low-cost MEMS sensors that uniquely combine silicon microfabrication technology with optoelectronic technology that can sense dynamic pressure, acceleration forces, acoustic emission, and many other aerospace parameters of interest. Honeywell's recent work in MEMS tuning fork gyros for inertial sensing and a MEMS free- piston engine are also described.

A Unique Self-Sensing, Self-Actuating AFM Probe at Higher Eigenmodes

PubMed Central

Wu, Zhichao; Guo, Tong; Tao, Ran; Liu, Leihua; Chen, Jinping; Fu, Xing; Hu, Xiaotang

2015-01-01

With its unique structure, the Akiyama probe is a type of tuning fork atomic force microscope probe. The long, soft cantilever makes it possible to measure soft samples in tapping mode. In this article, some characteristics of the probe at its second eigenmode are revealed by use of finite element analysis (FEA) and experiments in a standard atmosphere. Although the signal-to-noise ratio in this environment is not good enough, the 2 nm resolution and 0.09 Hz/nm sensitivity prove that the Akiyama probe can be used at its second eigenmode under FM non-contact mode or low amplitude FM tapping mode, which means that it is easy to change the measuring method from normal tapping to small amplitude tapping or non-contact mode with the same probe and equipment. PMID:26580619

Double-Paddle Oscillators as Probes of Quantum Turbulence in the Zero Temperature Limit

NASA Astrophysics Data System (ADS)

Schmoranzer, David; Jackson, Martin; Zemma, Elisa; Luzuriaga, Javier

2017-06-01

We present a technical report on our tests of a double-paddle oscillator as a detector of quantum turbulence in superfluid 4He at low temperatures ranging from 20 to 1100 mK. The device, known to operate well in the two-fluid regime (Zemma and Luzuriaga in J Low Temp Phys 166:171-181, 2012), is also capable of detecting quantum turbulence in the zero temperature limit. The oscillator demonstrated Lorentzian responses with quality factors of order 10^5 in vacuum, and displayed negative-Duffing resonances in liquid, even at moderate drives. In superfluid He-II at low temperatures, its sensitivity was adversely affected by acoustic damping at higher harmonics. While it successfully created and detected the quantum turbulence, its overall performance does not compare favourably with other oscillators such as tuning forks.

Installation Restoration Program. Phase I: Records Search Minot Air Force Base, North Dakota.

DTIC Science & Technology

1984-12-01

MAFB and Grand Forks AFB. This move localized command along with •. •• insuring that assigned units would be capable of conducting aerial...were realigned !•;>•’ to become members of the 57th AD. Also on May 1, Grand Forks AFB was \\.•/ assigned to the 4th AD at F.E. Warren AFB, Wyoming...potential for vertical - - stratification of possible ground water contaminants. During drilling, Shelby tube samples should be taken to provide soils

Mutations in DONSON disrupt replication fork stability and cause microcephalic dwarfism.

PubMed

Reynolds, John J; Bicknell, Louise S; Carroll, Paula; Higgs, Martin R; Shaheen, Ranad; Murray, Jennie E; Papadopoulos, Dimitrios K; Leitch, Andrea; Murina, Olga; Tarnauskaitė, Žygimantė; Wessel, Sarah R; Zlatanou, Anastasia; Vernet, Audrey; von Kriegsheim, Alex; Mottram, Rachel M A; Logan, Clare V; Bye, Hannah; Li, Yun; Brean, Alexander; Maddirevula, Sateesh; Challis, Rachel C; Skouloudaki, Kassiani; Almoisheer, Agaadir; Alsaif, Hessa S; Amar, Ariella; Prescott, Natalie J; Bober, Michael B; Duker, Angela; Faqeih, Eissa; Seidahmed, Mohammed Zain; Al Tala, Saeed; Alswaid, Abdulrahman; Ahmed, Saleem; Al-Aama, Jumana Yousuf; Altmüller, Janine; Al Balwi, Mohammed; Brady, Angela F; Chessa, Luciana; Cox, Helen; Fischetto, Rita; Heller, Raoul; Henderson, Bertram D; Hobson, Emma; Nürnberg, Peter; Percin, E Ferda; Peron, Angela; Spaccini, Luigina; Quigley, Alan J; Thakur, Seema; Wise, Carol A; Yoon, Grace; Alnemer, Maha; Tomancak, Pavel; Yigit, Gökhan; Taylor, A Malcolm R; Reijns, Martin A M; Simpson, Michael A; Cortez, David; Alkuraya, Fowzan S; Mathew, Christopher G; Jackson, Andrew P; Stewart, Grant S

2017-04-01

To ensure efficient genome duplication, cells have evolved numerous factors that promote unperturbed DNA replication and protect, repair and restart damaged forks. Here we identify downstream neighbor of SON (DONSON) as a novel fork protection factor and report biallelic DONSON mutations in 29 individuals with microcephalic dwarfism. We demonstrate that DONSON is a replisome component that stabilizes forks during genome replication. Loss of DONSON leads to severe replication-associated DNA damage arising from nucleolytic cleavage of stalled replication forks. Furthermore, ATM- and Rad3-related (ATR)-dependent signaling in response to replication stress is impaired in DONSON-deficient cells, resulting in decreased checkpoint activity and the potentiation of chromosomal instability. Hypomorphic mutations in DONSON substantially reduce DONSON protein levels and impair fork stability in cells from patients, consistent with defective DNA replication underlying the disease phenotype. In summary, we have identified mutations in DONSON as a common cause of microcephalic dwarfism and established DONSON as a critical replication fork protein required for mammalian DNA replication and genome stability.

Checkpoint-dependent RNR induction promotes fork restart after replicative stress.

PubMed

Morafraile, Esther C; Diffley, John F X; Tercero, José Antonio; Segurado, Mónica

2015-01-20

The checkpoint kinase Rad53 is crucial to regulate DNA replication in the presence of replicative stress. Under conditions that interfere with the progression of replication forks, Rad53 prevents Exo1-dependent fork degradation. However, although EXO1 deletion avoids fork degradation in rad53 mutants, it does not suppress their sensitivity to the ribonucleotide reductase (RNR) inhibitor hydroxyurea (HU). In this case, the inability to restart stalled forks is likely to account for the lethality of rad53 mutant cells after replication blocks. Here we show that Rad53 regulates replication restart through the checkpoint-dependent transcriptional response, and more specifically, through RNR induction. Thus, in addition to preventing fork degradation, Rad53 prevents cell death in the presence of HU by regulating RNR-expression and localization. When RNR is induced in the absence of Exo1 and RNR negative regulators, cell viability of rad53 mutants treated with HU is increased and the ability of replication forks to restart after replicative stress is restored.

Eukaryotic DNA Replication Fork.

PubMed

Burgers, Peter M J; Kunkel, Thomas A

2017-06-20

This review focuses on the biogenesis and composition of the eukaryotic DNA replication fork, with an emphasis on the enzymes that synthesize DNA and repair discontinuities on the lagging strand of the replication fork. Physical and genetic methodologies aimed at understanding these processes are discussed. The preponderance of evidence supports a model in which DNA polymerase ε (Pol ε) carries out the bulk of leading strand DNA synthesis at an undisturbed replication fork. DNA polymerases α and δ carry out the initiation of Okazaki fragment synthesis and its elongation and maturation, respectively. This review also discusses alternative proposals, including cellular processes during which alternative forks may be utilized, and new biochemical studies with purified proteins that are aimed at reconstituting leading and lagging strand DNA synthesis separately and as an integrated replication fork.

Geologic map of southwestern Sequoia National Park, Tulare County, California

USGS Publications Warehouse

Sisson, Thomas W.; Moore, James G.

2013-01-01

This map shows the geology of 675 km2 (260 mi2) on the west slope of the Sierra Nevada, California, mainly in Sequoia National Park and Sequoia National Forest. It was produced by the U.S. Geological Survey (USGS) at the request of the National Park Service to complete the geologic map coverage of Kings Canyon and Sequoia National Parks. The area includes the Mineral King 15’ topographic quadrangle (sheet 1) and strips along the east and northeast edges of the Kaweah 15’ topographic quadrangle (sheet 2), both in Tulare County. Mapping was performed mainly on the 1:24,000-scale Mineral King, Silver City, Quinn Peak, Moses Mountain, Case Mountain, and Dennison Peak 7.5’ topographic quadrangle bases. Rocks within the study area are chiefly Cretaceous granites and granodiorites of the Sierra Nevada batholith that intruded coherent masses of Mesozoic metasedimentary and metavolcanic rocks. Quaternary till and talus are the principal surficial deposits, with the exception of a large bouldery alluvial apron near the southwest corner of the map area. The study area includes the headwaters of the Kaweah River (East and South Forks), Tule River (North Fork and North Fork of the Middle Fork), and the Little Kern River. Relief is considerable, with elevations spanning from 1,500 feet along the Middle Fork Kaweah River to 12,432 feet at the summit of Florence Peak along the crest of the Great Western Divide.

Hydraulic geometry and sediment data for the South Fork Salmon River, Idaho, 1985-86

USGS Publications Warehouse

Williams, Rhea P.; O'Dell, Ivalou; Megahan, Walter F.

1989-01-01

Hydraulic geometry, suspended-sediment, and bedload samples were collected at three sites in the upper reach of the South Fork Salmon River drainage basin from April 1985 to June 1986. Sites selected were South Fork Salmon River near Krassel Ranger Station, Buckhorn Creek, and North Fork Lick Creek. Results of the data collection are presented in this report.

Apertureless near-field scanning optical microscope working with or without laser source.

PubMed

Formanek, F; De Wilde, Y; Aigouy, L; Chen, Y

2004-01-01

An apertureless near-field scanning optical microscope (ANSOM), used indifferent configurations, is presented. Our versatile home-made setup, based on a sharp tungsten tip glued onto a quartz tuning fork and working in tapping mode, allows to perform imaging over a broad spectral range. We have recorded optical images in the visible (wavelength, lambda = 655 nm) and in the infrared (lambda = 10.6 microm), proving that the setup routinely achieves an optical resolution of <50 nm regardless of the illumination wavelength. We have also shown optical images recorded in the visible (lambda = 655 nm) in an inverted configuration where the tip does not perturb the focused spot of the illumination laser. Approach curves as well as image profiles have revealed that on demodulating the optical signal at higher harmonics, we can obtain an effective probe sharpening which results in an improvement of the resolution. Finally, we have presented optical images recorded in the infrared without any illumination, that is, the usual laser source is replaced by a simple heating of the sample. This has shown that the ANSOM can be used as a near-field thermal optical microscope (NTOM) to probe the near field generated by the thermal emission of the sample.

True Tapping Mode Scanning Near-Field Optical Microscopy with Bent Glass Fiber Probes.

PubMed

Smirnov, A; Yasinskii, V M; Filimonenko, D S; Rostova, E; Dietler, G; Sekatskii, S K

2018-01-01

In scanning near-field optical microscopy, the most popular probes are made of sharpened glass fiber attached to a quartz tuning fork (TF) and exploiting the shear force-based feedback. The use of tapping mode feedback could be preferable. Such an approach can be realized, for example, using bent fiber probes. Detailed analysis of fiber vibration modes shows that realization of truly tapping mode of the probe dithering requires an extreme caution. In case of using the second resonance mode, probes vibrate mostly in shear force mode unless the bending radius is rather small (ca. 0.3 mm) and the probe's tip is short. Otherwise, the shear force character of the dithering persists. Probes having these characteristics were prepared by irradiation of a tapered etched glass fiber with a CW CO 2 laser. These probes were attached to the TF in double resonance conditions which enables achieving significant quality factor (4000-6000) of the TF + probe system (Cherkun et al., 2006). We also show that, to achieve a truly tapping character, dithering, short, and not exceeding 3 mm lengths of a freestanding part of bent fiber probe beam should also be used in the case of nonresonant excitation.

1. Roaring Fork Motor Nature Trail, entrance sign. Great ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

1. Roaring Fork Motor Nature Trail, entrance sign. - Great Smoky Mountains National Park Roads & Bridges, Roaring Fork Motor Nature Trail, Between Cherokee Orchard Road & U.S. Route 321, Gatlinburg, Sevier County, TN

Roaring Fork Motor Nature Trail, Title Sheet Great Smoky ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Roaring Fork Motor Nature Trail, Title Sheet - Great Smoky Mountains National Park Roads & Bridges, Roaring Fork Motor Nature Trail, Between Cherokee Orchard Road & U.S. Route 321, Gatlinburg, Sevier County, TN

9. Roaring Fork Motor Nature Trail, Reagan House. Great ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. Roaring Fork Motor Nature Trail, Reagan House. - Great Smoky Mountains National Park Roads & Bridges, Roaring Fork Motor Nature Trail, Between Cherokee Orchard Road & U.S. Route 321, Gatlinburg, Sevier County, TN

Regulation of Replication Fork Advance and Stability by Nucleosome Assembly

PubMed Central

Prado, Felix; Maya, Douglas

2017-01-01

The advance of replication forks to duplicate chromosomes in dividing cells requires the disassembly of nucleosomes ahead of the fork and the rapid assembly of parental and de novo histones at the newly synthesized strands behind the fork. Replication-coupled chromatin assembly provides a unique opportunity to regulate fork advance and stability. Through post-translational histone modifications and tightly regulated physical and genetic interactions between chromatin assembly factors and replisome components, chromatin assembly: (1) controls the rate of DNA synthesis and adjusts it to histone availability; (2) provides a mechanism to protect the integrity of the advancing fork; and (3) regulates the mechanisms of DNA damage tolerance in response to replication-blocking lesions. Uncoupling DNA synthesis from nucleosome assembly has deleterious effects on genome integrity and cell cycle progression and is linked to genetic diseases, cancer, and aging. PMID:28125036

Channelization and floodplain forests: impacts of accelerated sedimentation and valley plug formation on floodplain forests of the Middle Fork Forked Deer River, Tennessee, USA

Treesearch

Sonja N. Oswalt; Sammy L. King

2005-01-01

We evaluated the severe degradation of floodplain habitats resulting from channelization and concomitant excessive coarse sedimentation on the Middle Fork Forked Deer River in west Tennessee from 2000 to 2003. Land use practices have resulted in excessive sediment in the tributaries and river system eventually resulting in sand deposition on the floodplain, increased...

A ruthenium polypyridyl intercalator stalls DNA replication forks, radiosensitizes human cancer cells and is enhanced by Chk1 inhibition

NASA Astrophysics Data System (ADS)

Gill, Martin R.; Harun, Siti Norain; Halder, Swagata; Boghozian, Ramon A.; Ramadan, Kristijan; Ahmad, Haslina; Vallis, Katherine A.

2016-08-01

Ruthenium(II) polypyridyl complexes can intercalate DNA with high affinity and prevent cell proliferation; however, the direct impact of ruthenium-based intercalation on cellular DNA replication remains unknown. Here we show the multi-intercalator [Ru(dppz)2(PIP)]2+ (dppz = dipyridophenazine, PIP = 2-(phenyl)imidazo[4,5-f][1,10]phenanthroline) immediately stalls replication fork progression in HeLa human cervical cancer cells. In response to this replication blockade, the DNA damage response (DDR) cell signalling network is activated, with checkpoint kinase 1 (Chk1) activation indicating prolonged replication-associated DNA damage, and cell proliferation is inhibited by G1-S cell-cycle arrest. Co-incubation with a Chk1 inhibitor achieves synergistic apoptosis in cancer cells, with a significant increase in phospho(Ser139) histone H2AX (γ-H2AX) levels and foci indicating increased conversion of stalled replication forks to double-strand breaks (DSBs). Normal human epithelial cells remain unaffected by this concurrent treatment. Furthermore, pre-treatment of HeLa cells with [Ru(dppz)2(PIP)]2+ before external beam ionising radiation results in a supra-additive decrease in cell survival accompanied by increased γ-H2AX expression, indicating the compound functions as a radiosensitizer. Together, these results indicate ruthenium-based intercalation can block replication fork progression and demonstrate how these DNA-binding agents may be combined with DDR inhibitors or ionising radiation to achieve more efficient cancer cell killing.

A ruthenium polypyridyl intercalator stalls DNA replication forks, radiosensitizes human cancer cells and is enhanced by Chk1 inhibition.

PubMed

Gill, Martin R; Harun, Siti Norain; Halder, Swagata; Boghozian, Ramon A; Ramadan, Kristijan; Ahmad, Haslina; Vallis, Katherine A

2016-08-25

Ruthenium(II) polypyridyl complexes can intercalate DNA with high affinity and prevent cell proliferation; however, the direct impact of ruthenium-based intercalation on cellular DNA replication remains unknown. Here we show the multi-intercalator [Ru(dppz)2(PIP)](2+) (dppz = dipyridophenazine, PIP = 2-(phenyl)imidazo[4,5-f][1,10]phenanthroline) immediately stalls replication fork progression in HeLa human cervical cancer cells. In response to this replication blockade, the DNA damage response (DDR) cell signalling network is activated, with checkpoint kinase 1 (Chk1) activation indicating prolonged replication-associated DNA damage, and cell proliferation is inhibited by G1-S cell-cycle arrest. Co-incubation with a Chk1 inhibitor achieves synergistic apoptosis in cancer cells, with a significant increase in phospho(Ser139) histone H2AX (γ-H2AX) levels and foci indicating increased conversion of stalled replication forks to double-strand breaks (DSBs). Normal human epithelial cells remain unaffected by this concurrent treatment. Furthermore, pre-treatment of HeLa cells with [Ru(dppz)2(PIP)](2+) before external beam ionising radiation results in a supra-additive decrease in cell survival accompanied by increased γ-H2AX expression, indicating the compound functions as a radiosensitizer. Together, these results indicate ruthenium-based intercalation can block replication fork progression and demonstrate how these DNA-binding agents may be combined with DDR inhibitors or ionising radiation to achieve more efficient cancer cell killing.

Smarcal1-Mediated Fork Reversal Triggers Mre11-Dependent Degradation of Nascent DNA in the Absence of Brca2 and Stable Rad51 Nucleofilaments.

PubMed

Kolinjivadi, Arun Mouli; Sannino, Vincenzo; De Antoni, Anna; Zadorozhny, Karina; Kilkenny, Mairi; Técher, Hervé; Baldi, Giorgio; Shen, Rong; Ciccia, Alberto; Pellegrini, Luca; Krejci, Lumir; Costanzo, Vincenzo

2017-09-07

Brca2 deficiency causes Mre11-dependent degradation of nascent DNA at stalled forks, leading to cell lethality. To understand the molecular mechanisms underlying this process, we isolated Xenopus laevis Brca2. We demonstrated that Brca2 protein prevents single-stranded DNA gap accumulation at replication fork junctions and behind them by promoting Rad51 binding to replicating DNA. Without Brca2, forks with persistent gaps are converted by Smarcal1 into reversed forks, triggering extensive Mre11-dependent nascent DNA degradation. Stable Rad51 nucleofilaments, but not RPA or Rad51 T131P mutant proteins, directly prevent Mre11-dependent DNA degradation. Mre11 inhibition instead promotes reversed fork accumulation in the absence of Brca2. Rad51 directly interacts with the Pol α N-terminal domain, promoting Pol α and δ binding to stalled replication forks. This interaction likely promotes replication fork restart and gap avoidance. These results indicate that Brca2 and Rad51 prevent formation of abnormal DNA replication intermediates, whose processing by Smarcal1 and Mre11 predisposes to genome instability. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Co-localization of polar replication fork barriers and rRNA transcription terminators in mouse rDNA.

PubMed

López-estraño, C; Schvartzman, J B; Krimer, D B; Hernández, P

1998-03-27

We investigated the replication of the region where transcription terminates in mouse rDNA. It contains a replication fork barrier (RFB) that behaves in a polar manner, arresting only replication forks moving in the direction opposite to transcription. This RFB consists of several closely spaced fork arrest sites that co-localize with the transcription terminator elements, known as Sal boxes. Sal boxes are the target for mTTF-I (murine transcription termination factor I). These results suggest that both termination of rRNA transcription and replication fork arrest may share cis-acting as well as trans-acting factors. Copyright 1998 Academic Press Limited.

Development of a flood-warning system and flood-inundation mapping in Licking County, Ohio

USGS Publications Warehouse

Ostheimer, Chad J.

2012-01-01

Digital flood-inundation maps for selected reaches of South Fork Licking River, Raccoon Creek, North Fork Licking River, and the Licking River in Licking County, Ohio, were created by the U.S. Geological Survey (USGS), in cooperation with the Ohio Department of Transportation; U.S. Department of Transportation, Federal Highway Administration; Muskingum Watershed Conservancy District; U.S. Department of Agriculture, Natural Resources Conservation Service; and the City of Newark and Village of Granville, Ohio. The inundation maps depict estimates of the areal extent of flooding corresponding to water levels (stages) at the following USGS streamgages: South Fork Licking River at Heath, Ohio (03145173); Raccoon Creek below Wilson Street at Newark, Ohio (03145534); North Fork Licking River at East Main Street at Newark, Ohio (03146402); and Licking River near Newark, Ohio (03146500). The maps were provided to the National Weather Service (NWS) for incorporation into a Web-based flood-warning system that can be used in conjunction with NWS flood-forecast data to show areas of predicted flood inundation associated with forecasted flood-peak stages. As part of the flood-warning streamflow network, the USGS re-installed one streamgage on North Fork Licking River, and added three new streamgages, one each on North Fork Licking River, South Fork Licking River, and Raccoon Creek. Additionally, the USGS upgraded a lake-level gage on Buckeye Lake. Data from the streamgages and lake-level gage can be used by emergency-management personnel, in conjunction with the flood-inundation maps, to help determine a course of action when flooding is imminent. Flood profiles for selected reaches were prepared by calibrating steady-state step-backwater models to selected, established streamgage rating curves. The step-backwater models then were used to determine water-surface-elevation profiles for up to 10 flood stages at a streamgage with corresponding streamflows ranging from approximately the 50 to 0.2-percent chance annual-exceedance probabilities for each of the 4 streamgages that correspond to the flood-inundation maps. The computed flood profiles were used in combination with digital elevation data to delineate flood-inundation areas. Maps of Licking County showing flood-inundation areas overlain on digital orthophotographs are presented for the selected floods. The USGS also developed an unsteady-flow model for a reach of South Fork Licking River for use by the NWS to enhance their ability to provide advanced flood warning in the region north of Buckeye Lake, Ohio. The unsteady-flow model was calibrated based on data from four flooding events that occurred from June 2008 to December 2011. Model calibration was approximate due to the fact that there were unmeasured inflows to the river that were not able to be considered during the calibration. Information on unmeasured inflow derived from NWS hydrologic models and additional flood-event data could enable the NWS to further refine the unsteady-flow model.

8. Roaring Fork Motor Nature Trail, handbuilt rock pile. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. Roaring Fork Motor Nature Trail, hand-built rock pile. - Great Smoky Mountains National Park Roads & Bridges, Roaring Fork Motor Nature Trail, Between Cherokee Orchard Road & U.S. Route 321, Gatlinburg, Sevier County, TN

ATR-like kinase Mec1 facilitates both chromatin accessibility at DNA replication forks and replication fork progression during replication stress

PubMed Central

Rodriguez, Jairo; Tsukiyama, Toshio

2013-01-01

Faithful DNA replication is essential for normal cell division and differentiation. In eukaryotic cells, DNA replication takes place on chromatin. This poses the critical question as to how DNA replication can progress through chromatin, which is inhibitory to all DNA-dependent processes. Here, we developed a novel genome-wide method to measure chromatin accessibility to micrococcal nuclease (MNase) that is normalized for nucleosome density, the NCAM (normalized chromatin accessibility to MNase) assay. This method enabled us to discover that chromatin accessibility increases specifically at and ahead of DNA replication forks in normal S phase and during replication stress. We further found that Mec1, a key regulatory ATR-like kinase in the S-phase checkpoint, is required for both normal chromatin accessibility around replication forks and replication fork rate during replication stress, revealing novel functions for the kinase in replication stress response. These results suggest a possibility that Mec1 may facilitate DNA replication fork progression during replication stress by increasing chromatin accessibility around replication forks. PMID:23307868

Ribosomal DNA replication fork barrier and HOT1 recombination hot spot: shared sequences but independent activities.

PubMed

Ward, T R; Hoang, M L; Prusty, R; Lau, C K; Keil, R L; Fangman, W L; Brewer, B J

2000-07-01

In the ribosomal DNA of Saccharomyces cerevisiae, sequences in the nontranscribed spacer 3' of the 35S ribosomal RNA gene are important to the polar arrest of replication forks at a site called the replication fork barrier (RFB) and also to the cis-acting, mitotic hyperrecombination site called HOT1. We have found that the RFB and HOT1 activity share some but not all of their essential sequences. Many of the mutations that reduce HOT1 recombination also decrease or eliminate fork arrest at one of two closely spaced RFB sites, RFB1 and RFB2. A simple model for the juxtaposition of RFB and HOT1 sequences is that the breakage of strands in replication forks arrested at RFB stimulates recombination. Contrary to this model, we show here that HOT1-stimulated recombination does not require the arrest of forks at the RFB. Therefore, while HOT1 activity is independent of replication fork arrest, HOT1 and RFB require some common sequences, suggesting the existence of a common trans-acting factor(s).

Backwater at bridges and densely wooded flood plains, west fork Amite River near Liberty, Mississippi

USGS Publications Warehouse

Colson, B.E.; Ming, C.O.; Arcement, George J.

1979-01-01

Floodflow data that will provide a base for evaluating digital models relating to open-channel flow were obtained at 22 sites on streams in Alabama, Louisiana, and Mississippi. Thirty-five floods were measured. Analysis of the data indicated methods currently in use would be inaccurate where densely vegetated flood plains are crossed by highway embankments and single-opening bridges. This atlas presents flood information at the site on West Fork Amite River near Liberty, MS. Water depths , velocities, and discharges through bridge openings on West Fork Amite River near Liberty, MS for floods of December 6, 1971 , and March 25, 1973, are shown, together with peak water-surface elevations along embankments and along cross sections. Manning 's roughness coefficient values in different parts of the flood plain are shown on maps, and flood-frequency relations are shown on a graph. (USGS).

Analyzing the dynamics of DNA replication in Mammalian cells using DNA combing.

PubMed

Bialic, Marta; Coulon, Vincent; Drac, Marjorie; Gostan, Thierry; Schwob, Etienne

2015-01-01

How cells duplicate their chromosomes is a key determinant of cell identity and genome stability. DNA replication can initiate from more than 100,000 sites distributed along mammalian chromosomes, yet a given cell uses only a subset of these origins due to inefficient origin activation and regulation by developmental or environmental cues. An impractical consequence of cell-to-cell variations in origin firing is that population-based techniques do not accurately describe how chromosomes are replicated in single cells. DNA combing is a biophysical DNA fiber stretching method which permits visualization of ongoing DNA synthesis along Mb-sized single-DNA molecules purified from cells that were previously pulse-labeled with thymidine analogues. This allows quantitative measurements of several salient features of chromosome replication dynamics, such as fork velocity, fork asymmetry, inter-origin distances, and global instant fork density. In this chapter we describe how to obtain this information from asynchronous cultures of mammalian cells.

LOOKING EASTSOUTHEAST. Showing downstream side of completed bridge, from confluence ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

LOOKING EAST-SOUTHEAST. Showing downstream side of completed bridge, from confluence of Trinity and South Fork Trinity Rivers - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

7. Roaring Fork Motor Nature Trail, rocks along edge of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. Roaring Fork Motor Nature Trail, rocks along edge of road. - Great Smoky Mountains National Park Roads & Bridges, Roaring Fork Motor Nature Trail, Between Cherokee Orchard Road & U.S. Route 321, Gatlinburg, Sevier County, TN

5. Roaring Fork Motor Nature Trail, vista at stop three. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. Roaring Fork Motor Nature Trail, vista at stop three. - Great Smoky Mountains National Park Roads & Bridges, Roaring Fork Motor Nature Trail, Between Cherokee Orchard Road & U.S. Route 321, Gatlinburg, Sevier County, TN

15. INSIDE VIEW OF FLUME, LOOKING DOWNSTREAM, LEFT FORK TO ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. INSIDE VIEW OF FLUME, LOOKING DOWNSTREAM, LEFT FORK TO SETTLING BASIN, SHOWING RIGHT FORK WITH GATE IN PLACE AND A FEW NEEDLES IN PLACE - Electron Hydroelectric Project, Along Puyallup River, Electron, Pierce County, WA

2. Roaring Fork Motor Nature Trail, road view before first ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. Roaring Fork Motor Nature Trail, road view before first stop. - Great Smoky Mountains National Park Roads & Bridges, Roaring Fork Motor Nature Trail, Between Cherokee Orchard Road & U.S. Route 321, Gatlinburg, Sevier County, TN

6. Roaring Fork Motor Nature Trail, road view after stop ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. Roaring Fork Motor Nature Trail, road view after stop four. - Great Smoky Mountains National Park Roads & Bridges, Roaring Fork Motor Nature Trail, Between Cherokee Orchard Road & U.S. Route 321, Gatlinburg, Sevier County, TN

5. VIEW EAST ACROSS BRIDGE SHOWING RAILING DETAILS AND WATERFALLS ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. VIEW EAST ACROSS BRIDGE SHOWING RAILING DETAILS AND WATERFALLS OF THE SOUTH FORK OF THE TUOLUMNE. - South Fork Tuolumne River Bridge, Spanning South Fork Tuolumne River on Tioga Road, Mather, Tuolumne County, CA

Evaluating the impacts of logging activities on erosion and suspended sediment transport in the Caspar Creek watersheds

Treesearch

Jack Lewis

1998-01-01

Suspended sediment has been sampled at both the North and South Fork weirs of Caspar Creek in northwestern California since 1963, and at 13 tributary locations in the North Fork since 1986. The North Fork gaging station (NFC) was used as a control to evaluate the effects of logging in the South Fork, in the 1970's, on annual sediment loads. In the most...

A complex mechanism determines polarity of DNA replication fork arrest by the replication terminator complex of Bacillus subtilis.

PubMed

Duggin, Iain G; Matthews, Jacqueline M; Dixon, Nicholas E; Wake, R Gerry; Mackay, Joel P

2005-04-01

Two dimers of the replication terminator protein (RTP) of Bacillus subtilis bind to a chromosomal DNA terminator site to effect polar replication fork arrest. Cooperative binding of the dimers to overlapping half-sites within the terminator is essential for arrest. It was suggested previously that polarity of fork arrest is the result of the RTP dimer at the blocking (proximal) side within the complex binding very tightly and the permissive-side RTP dimer binding relatively weakly. In order to investigate this "differential binding affinity" model, we have constructed a series of mutant terminators that contain half-sites of widely different RTP binding affinities in various combinations. Although there appeared to be a correlation between binding affinity at the proximal half-site and fork arrest efficiency in vivo for some terminators, several deviated significantly from this correlation. Some terminators exhibited greatly reduced binding cooperativity (and therefore have reduced affinity at each half-site) but were highly efficient in fork arrest, whereas one terminator had normal affinity over the proximal half-site, yet had low fork arrest efficiency. The results show clearly that there is no direct correlation between the RTP binding affinity (either within the full complex or at the proximal half-site within the full complex) and the efficiency of replication fork arrest in vivo. Thus, the differential binding affinity over the proximal and distal half-sites cannot be solely responsible for functional polarity of fork arrest. Furthermore, efficient fork arrest relies on features in addition to the tight binding of RTP to terminator DNA.

South Fork Latrine, east elevation showing structure in context, view ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

South Fork Latrine, east elevation showing structure in context, view west - Fort McKinley, South Fork Latrine, West side of East Side Drive, approximately 225 feet south of Weymouth Way, Great Diamond Island, Portland, Cumberland County, ME

3. Roaring Fork Motor Nature Trail, view between second and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. Roaring Fork Motor Nature Trail, view between second and third stops - Great Smoky Mountains National Park Roads & Bridges, Roaring Fork Motor Nature Trail, Between Cherokee Orchard Road & U.S. Route 321, Gatlinburg, Sevier County, TN

11. Roaring Fork Motor Nature Trail, boulders along road after ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. Roaring Fork Motor Nature Trail, boulders along road after stop 13. - Great Smoky Mountains National Park Roads & Bridges, Roaring Fork Motor Nature Trail, Between Cherokee Orchard Road & U.S. Route 321, Gatlinburg, Sevier County, TN

2. VIEW OF NORTH FACE SHOWING SUBSTRUCTURE AND ABUTMENTS OF ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. VIEW OF NORTH FACE SHOWING SUBSTRUCTURE AND ABUTMENTS OF BRIDGE CROSSING THE SOUTH FORK OF THE TUOLUMNE RIVER. - South Fork Tuolumne River Bridge, Spanning South Fork Tuolumne River on Tioga Road, Mather, Tuolumne County, CA

Distribution and movement of bull trout in the upper Jarbidge River watershed, Nevada

USGS Publications Warehouse

Allen, M. Brady; Connolly, Patrick J.; Mesa, Matthew G.; Charrier, Jodi; Dixon, Chris

2010-01-01

In 2006 and 2007, we surveyed the occurrence of bull trout (Salvelinus confluentus), the relative distributions of bull trout and redband trout (Oncorhynchus mykiss), and stream habitat conditions in the East and West Forks of the Jarbidge River in northeastern Nevada and southern Idaho. We installed passive integrated transponder (PIT) tag interrogation systems at strategic locations within the watershed, and PIT-tagged bull trout were monitored to evaluate individual fish growth, movement, and the connectivity of bull trout between streams. Robust bull trout populations were found in the upper portions of the East Fork Jarbidge River, the West Fork Jarbidge River, and in the Pine, Jack, Dave, and Fall Creeks. Small numbers of bull trout also were found in Slide and Cougar Creeks. Bull trout were numerically dominant in the upper portions of the East Fork Jarbidge River, and in Fall, Dave, Jack, and Pine Creeks, whereas redband trout were numerically dominant throughout the rest of the watershed. The relative abundance of bull trout was notably higher at altitudes above 2,100 m. This study was successful in documenting bull trout population connectivity within the West Fork Jarbidge River, particularly between West Fork Jarbidge River and Pine Creek. Downstream movement of bull trout to the confluence of the East Fork and West Fork Jarbidge River both from Jack Creek (rkm 16.6) in the West Fork Jarbidge River and from Dave Creek (rkm 7.5) in the East Fork Jarbidge River was detected. Although bull trout exhibited some downstream movement during the spring and summer, much of their emigration occurred in the autumn, concurrent with decreasing water temperatures and slightly increasing flows. The bull trout that emigrated were mostly age-2 or older, but some age-1 fish also emigrated. Upstream movement by bull trout was detected less than downstream movement. The overall mean annual growth rate of bull trout in the East Fork and West Fork Jarbidge River was 36 mm. This growth rate is within the range reported in other river systems and is indicative of good habitat conditions. Mark-recapture methods were used to estimate a population of 147 age-1 or older bull trout in the reach of Jack Creek upstream of Jenny Creek.

Visualization of DNA Replication in the Vertebrate Model System DT40 using the DNA Fiber Technique

PubMed Central

Schwab, Rebekka A.V.; Niedzwiedz, Wojciech

2011-01-01

Maintenance of replication fork stability is of utmost importance for dividing cells to preserve viability and prevent disease. The processes involved not only ensure faithful genome duplication in the face of endogenous and exogenous DNA damage but also prevent genomic instability, a recognized causative factor in tumor development. Here, we describe a simple and cost-effective fluorescence microscopy-based method to visualize DNA replication in the avian B-cell line DT40. This cell line provides a powerful tool to investigate protein function in vivo by reverse genetics in vertebrate cells1. DNA fiber fluorography in DT40 cells lacking a specific gene allows one to elucidate the function of this gene product in DNA replication and genome stability. Traditional methods to analyze replication fork dynamics in vertebrate cells rely on measuring the overall rate of DNA synthesis in a population of pulse-labeled cells. This is a quantitative approach and does not allow for qualitative analysis of parameters that influence DNA synthesis. In contrast, the rate of movement of active forks can be followed directly when using the DNA fiber technique2-4. In this approach, nascent DNA is labeled in vivo by incorporation of halogenated nucleotides (Fig 1A). Subsequently, individual fibers are stretched onto a microscope slide, and the labeled DNA replication tracts are stained with specific antibodies and visualized by fluorescence microscopy (Fig 1B). Initiation of replication as well as fork directionality is determined by the consecutive use of two differently modified analogues. Furthermore, the dual-labeling approach allows for quantitative analysis of parameters that influence DNA synthesis during the S-phase, i.e. replication structures such as ongoing and stalled forks, replication origin density as well as fork terminations. Finally, the experimental procedure can be accomplished within a day, and requires only general laboratory equipment and a fluorescence microscope. PMID:22064662

A Cultural Resource Reconnaissance of Two Proposed Bank Unloading Areas, East Grand Forks, Polk County, Minnesota,

DTIC Science & Technology

1984-12-01

architectural or archeotogical evidence was identified. The southern unloading area includes the former sites of a brewery and a sawmill, both of... brewery and a sawmill, both of which were associated with 0 significant historic events and themes in the late nineteenth and early twentieth century...Forks Brewery (1888) . . . . . . . 16 Figure 4. The Grand Forks Lumber Company mill is located at A. -. Building at B is probably the East Grand Forks

Archaeological Investigations on the East Fork of the Salmon River, Custer County, Idaho.

DTIC Science & Technology

1984-01-01

coniferous environment in addition to pine marten (Martes americana), red squirrel (Tamiasciurus hudsonicus), porcupine (Erithizon dorsatum), mountain vole...can be seen in small herds throughout the East Fork valley from the Salmon River to Big Boulder Creek. Two bands of Rocky Mountain bighorn sheep...utilize the Challis Planning Unit, one on the East Fork and the other in the Birch Creek area. The East Fork herd is comprised of approximately 50-70

A dual role of BRCA1 in two distinct homologous recombination mediated repair in response to replication arrest

PubMed Central

Feng, Zhihui; Zhang, Junran

2012-01-01

Homologous recombination (HR) is a major mechanism utilized to repair blockage of DNA replication forks. Here, we report that a sister chromatid exchange (SCE) generated by crossover-associated HR efficiently occurs in response to replication fork stalling before any measurable DNA double-strand breaks (DSBs). Interestingly, SCE produced by replication fork collapse following DNA DSBs creation is specifically suppressed by ATR, a central regulator of the replication checkpoint. BRCA1 depletion leads to decreased RPA2 phosphorylation (RPA2-P) following replication fork stalling but has no obvious effect on RPA2-P following replication fork collapse. Importantly, we found that BRCA1 promotes RAD51 recruitment and SCE induced by replication fork stalling independent of ATR. In contrast, BRCA1 depletion leads to a more profound defect in RAD51 recruitment and SCE induced by replication fork collapse when ATR is depleted. We concluded that BRCA1 plays a dual role in two distinct HR-mediated repair upon replication fork stalling and collapse. Our data established a molecular basis for the observation that defective BRCA1 leads to a high sensitivity to agents that cause replication blocks without being associated with DSBs, and also implicate a novel mechanism by which loss of cell cycle checkpoints promotes BRCA1-associated tumorigenesis via enhancing HR defect resulting from BRCA1 deficiency. PMID:21954437

Dissolved-Solids Load in Henrys Fork Upstream from the Confluence with Antelope Wash, Wyoming, Water Years 1970-2009

USGS Publications Warehouse

Foster, Katharine; Kenney, Terry A.

2010-01-01

Annual dissolved-solids load at the mouth of Henrys Fork was estimated by using data from U.S. Geological Survey streamflow-gaging station 09229500, Henrys Fork near Manila, Utah. The annual dissolved-solids load for water years 1970-2009 ranged from 18,300 tons in 1977 to 123,300 tons in 1983. Annual streamflows for this period ranged from 14,100 acre-feet in 1977 to 197,500 acre-feet in 1983. The 25-percent trimmed mean dissolved-solids load for water years 1970-2009 was 44,300 tons per year at Henrys Fork near Manila, Utah. Previous simulations using a SPAtially Referenced Regression On Watershed attributes (SPARROW) model for dissolved solids specific to water year 1991 conditions in the Upper Colorado River Basin predicted an annual dissolved-solids load of 25,000 tons for the Henrys Fork Basin upstream from Antelope Wash. On the basis of computed dissolved-solids load data from Henrys Fork near Manila, Utah, together with estimated annual dissolved-solids load from Antelope Wash and Peoples Canal, this prediction was adjusted to 37,200 tons. As determined by simulations with the Upper Colorado River Basin SPARROW model, approximately 56 percent (14,000 tons per year) of the dissolved-solids load at Henrys Fork upstream from Antelope Wash is associated with the 21,500 acres of irrigated agricultural lands in the upper Henrys Fork Basin.

South Fork Latrine, oblique view showing south and east sides; ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

South Fork Latrine, oblique view showing south and east sides; view northwest - Fort McKinley, South Fork Latrine, West side of East Side Drive, approximately 225 feet south of Weymouth Way, Great Diamond Island, Portland, Cumberland County, ME

South Fork Latrine showing north and west sides, general view ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

South Fork Latrine showing north and west sides, general view to southeast - Fort McKinley, South Fork Latrine, West side of East Side Drive, approximately 225 feet south of Weymouth Way, Great Diamond Island, Portland, Cumberland County, ME

COMPLETED STRUCTURE. View is eastsoutheast of downstream side of bridge, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

COMPLETED STRUCTURE. View is east-southeast of downstream side of bridge, from beyond confluence of Trinity and South Fork Trinity Rivers - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

7. View to southeast. View of downstream side of bridge ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

7. View to southeast. View of downstream side of bridge from confluence of Trinity and South Fork Trinity Rivers. (90mm Lens) - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

50 CFR 226.211 - Critical habitat for Seven Evolutionarily Significant Units (ESUs) of Salmon (Oncorhynchus spp...

Code of Federal Regulations, 2014 CFR

2014-10-01

... form and maintain physical habitat conditions and support juvenile growth and mobility; (ii) Water...); Fossil Creek (39.9447, -123.0403); Middle Fork Eel River (40.0780, -123.0442); North Fork Middle Fork Eel...

50 CFR 226.211 - Critical habitat for Seven Evolutionarily Significant Units (ESUs) of Salmon (Oncorhynchus spp...

Code of Federal Regulations, 2011 CFR

2011-10-01

... form and maintain physical habitat conditions and support juvenile growth and mobility; (ii) Water...); Fossil Creek (39.9447, -123.0403); Middle Fork Eel River (40.0780, -123.0442); North Fork Middle Fork Eel...

50 CFR 226.211 - Critical habitat for Seven Evolutionarily Significant Units (ESUs) of Salmon (Oncorhynchus spp...

Code of Federal Regulations, 2013 CFR

2013-10-01

... form and maintain physical habitat conditions and support juvenile growth and mobility; (ii) Water...); Fossil Creek (39.9447, -123.0403); Middle Fork Eel River (40.0780, -123.0442); North Fork Middle Fork Eel...

50 CFR 226.211 - Critical habitat for Seven Evolutionarily Significant Units (ESUs) of Salmon (Oncorhynchus spp...

Code of Federal Regulations, 2012 CFR

2012-10-01

... form and maintain physical habitat conditions and support juvenile growth and mobility; (ii) Water...); Fossil Creek (39.9447, -123.0403); Middle Fork Eel River (40.0780, -123.0442); North Fork Middle Fork Eel...

50 CFR 226.211 - Critical habitat for Seven Evolutionarily Significant Units (ESUs) of Salmon (Oncorhynchus spp...

Code of Federal Regulations, 2010 CFR

2010-10-01

... form and maintain physical habitat conditions and support juvenile growth and mobility; (ii) Water...); Fossil Creek (39.9447, -123.0403); Middle Fork Eel River (40.0780, -123.0442); North Fork Middle Fork Eel...

LAKE FORK

EPA Science Inventory

The Lake Fork of the Arkansas River Watershed has been adversely affected through mining, water diversion and storage projects, grazing, logging, and other human influences over the past 120 years. It is the goals of the LFWWG to improve the health of Lake fork by addressing th...

12. Roaring Fork Motor Nature Trail, place of a thousand ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. Roaring Fork Motor Nature Trail, place of a thousand drips, view from road. - Great Smoky Mountains National Park Roads & Bridges, Roaring Fork Motor Nature Trail, Between Cherokee Orchard Road & U.S. Route 321, Gatlinburg, Sevier County, TN

Evaluation of the Life History of Native Salmonids in the Malheur River Basin; Cooperative Bull Trout/Redband Trout Research Project, 1999-2000 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwabe, Lawrence; Tiley, Mark; Perkins, Raymond R.

2000-11-01

The purpose of this study is to document the seasonal distribution of adult/sub-adult bull trout (Salvelinus confluentus) in the Malheur River basin. Due to the decline of bull trout in the Columbia Basin, the United States Fish and Wildlife Service listed bull trout as a threatened species in June 1998. Past land management activities; construction of dams; and fish eradication projects in the North Fork and Middle Fork Malheur River by poisoning have worked in concert to cumulatively impact native species in the Malheur Basin (Bowers et. al. 1993). Survival of the remaining bull trout populations is severely threatened (Buchananmore » 1997). 1999 Research Objects are: (1) Document the migratory patterns of adult/sub-adult bull trout in the North Fork Malheur River; (2) Determine the seasonal bull trout use of Beulah Reservoir and bull trout entrainment; and (3) Timing and location of bull trout spawning in the North Fork Malheur River basin. The study area includes the Malheur basin from the mouth of the Malheur River located near Ontario, Oregon to the headwaters of the North Fork Malheur River (Map 1). All fish collected and most of the telemetry effort was done on the North Fork Malheur River subbasin (Map 2). Fish collection was conducted on the North Fork Malheur River at the tailwaters of Beulah Reservoir (RK 29), Beulah Reservoir (RK 29-RK 33), and in the North Fork Malheur River at Crane Crossing (RK 69) to the headwaters of the North Fork Malheur. Radio telemetry was done from the mouth of the Malheur River in Ontario, Oregon to the headwaters of the North Fork Malheur. This report will reflect all migration data collected from 3/1/99 to 12/31/99.« less

Quartz-Enhanced Photoacoustic Spectroscopy with Right-Angle Prism.

PubMed

Liu, Yongning; Chang, Jun; Lian, Jie; Liu, Zhaojun; Wang, Qiang; Qin, Zengguang

2016-02-06

A right-angle prism was used to enhance the acoustic signal of a quartz-enhanced photoacoustic spectroscopy (QEPAS) system. The incident laser beam was parallelly inverted by the right-angle prism and passed through the gap between two tuning fork prongs again to produce another acoustic excitation. Correspondingly, two pairs of rigid metal tubes were used as acoustic resonators with resonance enhancement factors of 16 and 12, respectively. The QEPAS signal was enhanced by a factor of 22.4 compared with the original signal, which was acquired without resonators or a prism. In addition, the system noise was reduced a little with double resonators due to the Q factor decrease. The signal-to-noise ratio (SNR) was greatly improved. Additionally, a normalized noise equivalent absorption coefficient (NNEA) of 5.8 × 10(-8) W·cm(-1)·Hz(-1/2) was achieved for water vapor detection in the atmosphere.

South Fork Telephone Switchboard Building, oblique view of east side; ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

South Fork Telephone Switchboard Building, oblique view of east side; view northwest - Fort McKinley, South Fork Telephone Switchboard Building, South side of Weymouth Way, approximately 100 feet west of East Side Drive, Great Diamond Island, Portland, Cumberland County, ME

South Fork Telephone Switchboard Building, interior west room showing hardwood ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

South Fork Telephone Switchboard Building, interior west room showing hardwood floor; view south - Fort McKinley, South Fork Telephone Switchboard Building, South side of Weymouth Way, approximately 100 feet west of East Side Drive, Great Diamond Island, Portland, Cumberland County, ME

South Fork Latrine, interior showing head with steel tank mounted ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

South Fork Latrine, interior showing head with steel tank mounted to wall; view south - Fort McKinley, South Fork Latrine, West side of East Side Drive, approximately 225 feet south of Weymouth Way, Great Diamond Island, Portland, Cumberland County, ME

14. Roaring Fork Motor Nature Trail, Place of a thousand ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. Roaring Fork Motor Nature Trail, Place of a thousand drips, view with three culvert pipes. - Great Smoky Mountains National Park Roads & Bridges, Roaring Fork Motor Nature Trail, Between Cherokee Orchard Road & U.S. Route 321, Gatlinburg, Sevier County, TN

Class I Histone Deacetylase HDAC1 and WRN RECQ Helicase Contribute Additively to Protect Replication Forks upon Hydroxyurea-induced Arrest.

PubMed

Kehrli, Keffy; Phelps, Michael; Lazarchuk, Pavlo; Chen, Eleanor; Monnat, Ray; Sidorova, Julia M

2016-11-18

The WRN helicase/exonuclease is mutated in Werner syndrome of genomic instability and premature aging. WRN-depleted fibroblasts, although remaining largely viable, have a reduced capacity to maintain replication forks active during a transient hydroxyurea-induced arrest. A strand exchange protein, RAD51, is also required for replication fork maintenance, and here we show that recruitment of RAD51 to stalled forks is reduced in the absence of WRN. We performed a siRNA screen for genes that are required for viability of WRN-depleted cells after hydroxyurea treatment, and identified HDAC1, a member of the class I histone deacetylase family. One of the functions of HDAC1, which it performs together with a close homolog HDAC2, is deacetylation of new histone H4 deposited at replication forks. We show that HDAC1 depletion exacerbates defects in fork reactivation and progression after hydroxyurea treatment observed in WRN- or RAD51-deficient cells. The additive WRN, HDAC1 loss-of-function phenotype is also observed with a catalytic mutant of HDAC1; however, it does not correlate with changes in histone H4 deacetylation at replication forks. On the other hand, inhibition of histone deacetylation by an inhibitor specific to HDACs 1-3, CI-994, correlates with increased processing of newly synthesized DNA strands in hydroxyurea-stalled forks. WRN co-precipitates with HDAC1 and HDAC2. Taken together, our findings indicate that WRN interacts with HDACs 1 and 2 to facilitate activity of stalled replication forks under conditions of replication stress. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Progress report on the effects of highway construction on suspended-sediment discharge in the Coal River and Trace Fork, West Virginia, 1975-81

USGS Publications Warehouse

Downs, S.C.; Appel, David H.

1986-01-01

Construction of the four-lane Appalachian Corridon G highway disturbed about 2 sq mi in the Coal River and 0.35 sq mi of the 4.75 sq mi Trace Fork basin in southern West Virginia. Construction had a negligible effect on runoff and suspended-sediment load in the Coal River and its major tributaries, the Little Coal and Big Coal Rivers. Drainage areas of the mainstem sites in the Coal River basin ranged from 269 to 862 sq mi, and average annual suspended-sediment yields ranged from 535 to 614 tons/sq mi for the 1975-81 water years. Suspended-sediment load in the smaller Trace Fork basin (4.72 sq mi) was significantly affected by the highway construction. Based on data from undisturbed areas upstream from construction, the normal background load at Trace Fork downstream from construction during the period July 1980 to September 1981 was estimated to be 830 tons; the measured load was 2,385 tons. Runoff from the 0.35 sq mi area disturbed by highway construction transported approximately 1,550 tons of sediment. Suspended-sediment loads from the construction zone were also higher than normal background loads during storms. (USGS)

South Fork Telephone Switchboard Building, general view in setting showing ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

South Fork Telephone Switchboard Building, general view in setting showing (N) side; view (S) - Fort McKinley, South Fork Telephone Switchboard Building, South side of Weymouth Way, approximately 100 feet west of East Side Drive, Great Diamond Island, Portland, Cumberland County, ME

South Fork Telephone Switchboard Building, oblique view of (W) and ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

South Fork Telephone Switchboard Building, oblique view of (W) and (S) sides, view to northeast - Fort McKinley, South Fork Telephone Switchboard Building, South side of Weymouth Way, approximately 100 feet west of East Side Drive, Great Diamond Island, Portland, Cumberland County, ME

STEEL ERECTION. View of downstream of bridge, looking southeast from ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

STEEL ERECTION. View of downstream of bridge, looking southeast from confluence of Trinity and South Fork Trinity rivers. The old suspension bridge is in background - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

Stabilization of Reversed Replication Forks by Telomerase Drives Telomere Catastrophe.

PubMed

Margalef, Pol; Kotsantis, Panagiotis; Borel, Valerie; Bellelli, Roberto; Panier, Stephanie; Boulton, Simon J

2018-01-25

Telomere maintenance critically depends on the distinct activities of telomerase, which adds telomeric repeats to solve the end replication problem, and RTEL1, which dismantles DNA secondary structures at telomeres to facilitate replisome progression. Here, we establish that reversed replication forks are a pathological substrate for telomerase and the source of telomere catastrophe in Rtel1 -/- cells. Inhibiting telomerase recruitment to telomeres, but not its activity, or blocking replication fork reversal through PARP1 inhibition or depleting UBC13 or ZRANB3 prevents the rapid accumulation of dysfunctional telomeres in RTEL1-deficient cells. In this context, we establish that telomerase binding to reversed replication forks inhibits telomere replication, which can be mimicked by preventing replication fork restart through depletion of RECQ1 or PARG. Our results lead us to propose that telomerase inappropriately binds to and inhibits restart of reversed replication forks within telomeres, which compromises replication and leads to critically short telomeres. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Progerin sequestration of PCNA promotes replication fork collapse and mislocalization of XPA in laminopathy-related progeroid syndromes.

PubMed

Hilton, Benjamin A; Liu, Ji; Cartwright, Brian M; Liu, Yiyong; Breitman, Maya; Wang, Youjie; Jones, Rowdy; Tang, Hui; Rusinol, Antonio; Musich, Phillip R; Zou, Yue

2017-09-01

Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder that is caused by a point mutation in the LMNA gene, resulting in production of a truncated farnesylated-prelamin A protein (progerin). We previously reported that XPA mislocalized to the progerin-induced DNA double-strand break (DSB) sites, blocking DSB repair, which led to DSB accumulation, DNA damage responses, and early replication arrest in HGPS. In this study, the XPA mislocalization to DSBs occurred at stalled or collapsed replication forks, concurrent with a significant loss of PCNA at the forks, whereas PCNA efficiently bound to progerin. This PCNA sequestration likely exposed ds-ssDNA junctions at replication forks for XPA binding. Depletion of XPA or progerin each significantly restored PCNA at replication forks. Our results suggest that although PCNA is much more competitive than XPA in binding replication forks, PCNA sequestration by progerin may shift the equilibrium to favor XPA binding. Furthermore, we demonstrated that progerin-induced apoptosis could be rescued by XPA, suggesting that XPA-replication fork binding may prevent apoptosis in HGPS cells. Our results propose a mechanism for progerin-induced genome instability and accelerated replicative senescence in HGPS.-Hilton, B. A., Liu, J., Cartwright, B. M., Liu, Y., Breitman, M., Wang, Y., Jones, R., Tang, H., Rusinol, A., Musich, P. R., Zou, Y. Progerin sequestration of PCNA promotes replication fork collapse and mislocalization of XPA in laminopathy-related progeroid syndromes. © FASEB.

The effectiveness of front fork systems at damping accelerations during isolated aspects specific to cross-country mountain biking.

PubMed

Macdermid, Paul W; Miller, Matthew C; Fink, Philip W; Stannard, Stephen R

2017-11-01

Cross-country mountain bike suspension reportedly enhances comfort and performance through reduced vibration and impact exposure. This study analysed the effectiveness of three different front fork systems at damping accelerations during the crossing of three isolated obstacles (stairs, drop, and root). One participant completed three trials on six separate occasions in a randomised order using rigid, air-sprung, and carbon leaf-sprung forks. Performance was determined by time to cross obstacles, while triaxial accelerometers quantified impact exposure and damping response. Results identified significant main effect of fork type for performance time (p < 0.05). The air-sprung and leaf-sprung forks were significantly slower than the rigid forks for the stairs (p < 0.05), while air-sprung suspension was slower than the rigid for the root protocol (p < 0.05). There were no differences for the drop protocol (p < 0.05). Rigid forks reduced overall exposure (p < 0.05), specifically at the handlebars for the stairs and drop trials. More detailed analysis presented smaller vertical accelerations at the handlebar for air-sprung and leaf-sprung forks on the stairs (p < 0.05), and drop (p < 0.05) but not the root. As such, it appears that the suspension systems tested were ineffective at reducing overall impact exposure at the handlebar during isolated aspects of cross-country terrain features which may be influenced to a larger extent by rider technique.

An annotated bibliography of the hydrology and fishery studies of the South Fork Salmon River

Treesearch

Kathleen A. Seyedbagheri; Michael L. McHenry; William S. Platts

1987-01-01

A brief summary of the land management history of the South Fork Salmon River (Idaho) watershed includes citations and annotations of published and unpublished reports of fishery and hydrology studies conducted in the South Fork drainage for 1960 to 1986.

OLD SUSPENSION BRIDGE. This view appears to be looking southeast, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

OLD SUSPENSION BRIDGE. This view appears to be looking southeast, at the downstream side of the suspension bridge, which was replaced by the South Fork Trinity River Bridge - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

Impact. The southwest end is down, as the buckled middle ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Impact. The southwest end is down, as the buckled middle section splashes into the river. View is to southeast from confluence of Trinity and South Fork Trinity Rivers - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

The ophiolitic North Fork terrane in the Salmon River region, central Klamath Mountains, California

USGS Publications Warehouse

Ando, C.J.; Irwin, W.P.; Jones, D.L.; Saleeby, J.B.

1983-01-01

The North Fork terrane is an assemblage of ophiolitic and other oceanic volcanic and sedimentary rocks that has been internally imbricated and folded. The ophiolitic rocks form a north-trending belt through the central part of the region and consist of a disrupted sequence of homogeneous gabbro, diabase, massive to pillowed basalt, and interleaved tectonitic harzburgite. U-Pb zircon age data on a plagiogranite pod from the gabbroic unit indicate that at least this part of the igneous sequence is late Paleozoic in age.The ophiolitic belt is flanked on either side by mafic volcanic and volcaniclastic rocks, limestone, bedded chert, and argillite. Most of the chert is Triassic, including much of Late Triassic age, but chert with uncertain stratigraphic relations at one locality is Permian. The strata flanking the east side of the ophiolitic belt face eastward, and depositional contacts between units are for the most part preserved. The strata on the west side of the ophiolitic belt are more highly disrupted than those on the east side, contain chert-argillite melange, and have unproven stratigraphic relation to either the ophiolitic rocks or the eastern strata.Rocks of the North Fork terrane do not show widespread evidence of penetrative deformation at elevated temperatures, except an early tectonitic fabric in the harzburgite. Slip-fiber foliation in serpentinite, phacoidal foliation in chert and mafic rocks, scaly foliation in argillite, and mesoscopic folds in bedded chert are consistent with an interpretation of large-scale anti-formal folding of the terrane about a north-south hinge found along the ophiolitic belt, but other structural interpretations are tenable. The age of folding of North Fork rocks is constrained by the involvement of Triassic and younger cherts and crosscutting Late Jurassic plutons. Deformation in the North Fork terrane must have spanned a short period of time because the terrane is bounded structurally above and below by Middle or Late Jurassic thrust faults.The North Fork terrane appears to contain no arc volcanic rocks or arc-derived detritus, suggesting that it neither constituted the base for an arc nor was in a basinal setting adjacent to an arc sediment source. Details of the progressive accretion and evolutionary relationship of the North Fork to other terranes of the Klamath Mountains are not yet clear.

Aftermath. The remains of the southwest end of the bridge ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Aftermath. The remains of the southwest end of the bridge lie next to the southwest pier. View is south-southeast from confluence of Trinity and South Fork Trinity Rivers - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

Dust trailing from the top chord, the bridge falls toward ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Dust trailing from the top chord, the bridge falls toward the river, as the southwest end (right) falls first. View southeast from confluence of Trinity and South Fork Trinity Rivers - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

With water still in midflight, the northeast end of the ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

With water still in mid-flight, the northeast end of the bridge (left) nears total collapse. View is to southeast from confluence of Trinity and South Fork Trinity Rivers - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

76 FR 13572 - Proposed Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-14

.... Specifically, it addresses the following flooding sources: Left Bank Overflow Main Stem Skagit River, Left Bank Overflow Main Stem Skagit River/South Fork Skagit River, Left Bank Overflow North Fork Skagit River, Main Stem Skagit River, North Fork Skagit River, Overflow from the Main Stem Skagit River between the North...

16 CFR Figure 1 to Part 1512 - Bicycle Front Fork Cantilever Bending Test Rig

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Bicycle Front Fork Cantilever Bending Test Rig 1 Figure 1 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS... Fork Cantilever Bending Test Rig EC03OC91.070 ...

16 CFR Figure 1 to Part 1512 - Bicycle Front Fork Cantilever Bending Test Rig

Code of Federal Regulations, 2011 CFR

2011-01-01

... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Bicycle Front Fork Cantilever Bending Test Rig 1 Figure 1 to Part 1512 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS... Fork Cantilever Bending Test Rig EC03OC91.070 ...

Claspin Promotes Normal Replication Fork Rates in Human Cells

PubMed Central

Helleday, Thomas; Caldecott, Keith W.

2008-01-01

The S phase-specific adaptor protein Claspin mediates the checkpoint response to replication stress by facilitating phosphorylation of Chk1 by ataxia-telangiectasia and Rad3-related (ATR). Evidence suggests that these components of the ATR pathway also play a critical role during physiological S phase. Chk1 is required for high rates of global replication fork progression, and Claspin interacts with the replication machinery and might therefore monitor normal DNA replication. Here, we have used DNA fiber labeling to investigate, for the first time, whether human Claspin is required for high rates of replication fork progression during normal S phase. We report that Claspin-depleted HeLa and HCT116 cells display levels of replication fork slowing similar to those observed in Chk1-depleted cells. This was also true in primary human 1BR3 fibroblasts, albeit to a lesser extent, suggesting that Claspin is a universal requirement for high replication fork rates in human cells. Interestingly, Claspin-depleted cells retained significant levels of Chk1 phosphorylation at both Ser317 and Ser345, raising the possibility that Claspin function during normal fork progression may extend beyond facilitating phosphorylation of either individual residue. Consistent with this possibility, depletion of Chk1 and Claspin together doubled the percentage of very slow forks, compared with depletion of either protein alone. PMID:18353973

Assessment of water and proppant quantities associated with petroleum production from the Bakken and Three Forks Formations, Williston Basin Province, Montana and North Dakota, 2016

USGS Publications Warehouse

Haines, Seth S.; Varela, Brian A.; Hawkins, Sarah J.; Gianoutsos, Nicholas J.; Thamke, Joanna N.; Engle, Mark A.; Tennyson, Marilyn E.; Schenk, Christopher J.; Gaswirth, Stephanie B.; Marra, Kristen R.; Kinney, Scott A.; Mercier, Tracey J.; Martinez, Cericia D.

2017-06-23

The U.S. Geological Survey (USGS) has completed an assessment of water and proppant requirements and water production associated with the possible future production of undiscovered oil and gas resources in the Three Forks and Bakken Formations (Late Devonian to Early Mississippian) of the Williston Basin Province in Montana and North Dakota. This water and proppant assessment is directly linked to the geology-based assessment of the undiscovered, technically recoverable continuous oil and gas resources that is described in USGS Fact Sheet 2013–3013.

Mercury and selenium concentrations in biofilm, macroinvertebrates, and fish collected in the Yankee Fork of the Salmon River, Idaho, USA, and their potential effects on fish health.

PubMed

Rhea, Darren T; Farag, Aïda M; Harper, David D; McConnell, Elizabeth; Brumbaugh, William G

2013-01-01

The Yankee Fork is a large tributary of the Salmon River located in central Idaho, USA, with an extensive history of placer and dredge-mining activities. Concentrations of selenium (Se) and mercury (Hg) in various aquatic trophic levels were measured in the Yankee Fork during 2001 and 2002. Various measurements of fish health were also performed. Sites included four on the mainstem of the Yankee Fork and two off-channel sites in partially reclaimed dredge pools used as rearing habitat for cultured salmonid eggs and fry. Hg concentrations in whole mountain whitefish and shorthead sculpin ranged from 0.28 to 0.56 μg/g dry weight (dw), concentrations that are generally less than those reported to have significant impacts on fish. Biofilm and invertebrates ranged from 0.05 to 0.43 μg Hg/g dw. Se concentrations measured in biota samples from the Yankee Fork were greater than many representative samples collected in the Snake and Columbia watersheds and often exceeded literature-based toxic thresholds. Biofilm and invertebrates ranged from 0.58 to 4.66 μg Se/g dw. Whole fish ranged from 3.92 to 7.10 μg Se/g dw, and gonads ranged from 6.91 to 31.84 μg Se/g dw. Whole-body Se concentrations exceeded reported toxicological thresholds at three of four sites and concentrations in liver samples were mostly greater than concentrations shown to have negative impacts on fish health. Histological examinations performed during this study noted liver abnormalities, especially in shorthead sculpin, a bottom-dwelling species.

Mercury and selenium concentrations in biofilm, macroinvertebrates, and fish collected in the Yankee Fork of the Salmon River, Idaho, USA, and their potential effects on fish health

USGS Publications Warehouse

Rhea, Darren T.; Farag, Aïda M.; Harper, David D.; McConnell, Elizabeth; Brumbaugh, William G.

2013-01-01

The Yankee Fork is a large tributary of the Salmon River located in central Idaho, USA, with an extensive history of placer and dredge-mining activities. Concentrations of selenium (Se) and mercury (Hg) in various aquatic trophic levels were measured in the Yankee Fork during 2001 and 2002. Various measurements of fish health were also performed. Sites included four on the mainstem of the Yankee Fork and two off-channel sites in partially reclaimed dredge pools used as rearing habitat for cultured salmonid eggs and fry. Hg concentrations in whole mountain whitefish and shorthead sculpin ranged from 0.28 to 0.56 μg/g dry weight (dw), concentrations that are generally less than those reported to have significant impacts on fish. Biofilm and invertebrates ranged from 0.05 to 0.43 μg Hg/g dw. Se concentrations measured in biota samples from the Yankee Fork were greater than many representative samples collected in the Snake and Columbia watersheds and often exceeded literature-based toxic thresholds. Biofilm and invertebrates ranged from 0.58 to 4.66 μg Se/g dw. Whole fish ranged from 3.92 to 7.10 μg Se/g dw, and gonads ranged from 6.91 to 31.84 μg Se/g dw. Whole-body Se concentrations exceeded reported toxicological thresholds at three of four sites and concentrations in liver samples were mostly greater than concentrations shown to have negative impacts on fish health. Histological examinations performed during this study noted liver abnormalities, especially in shorthead sculpin, a bottom-dwelling species.

Estimated effects on water quality of Lake Houston from interbasin transfer of water from the Trinity River, Texas

USGS Publications Warehouse

Liscum, Fred; East, Jeffery W.

2000-01-01

The City of Houston is considering the transfer of water from the Trinity River to Lake Houston (on the San Jacinto River) to alleviate concerns about adequate water supplies for future water demands. The U.S. Geological Survey, in cooperation with the City of Houston, conducted a study to estimate the effects on the water quality of Lake Houston from the transfer of Trinity River water. A water-quality model, CE–QUAL–W2, was used to simulate six water-quality properties and constituents for scenarios of interbasin transfer of Trinity River water. Three scenarios involved the transferred Trinity River water augmenting streamflow in the East Fork of Lake Houston, and three scenarios involved the transferred water replacing streamflow from the West Fork of the San Jacinto River.The estimated effects on Lake Houston were determined by comparing volume-weighted daily mean water temperature, phosphorus, ammonia nitrogen, nitrite plus nitrate nitrogen, algal biomass, and dissolved oxygen simulated for each of the transfer scenarios to simulations for a base dataset. The effects of the interbasin transfer on Lake Houston do not appear to be detrimental to water temperature, ammonia nitrogen, or dissolved oxygen. Phosphorus and nitrite plus nitrate nitrogen showed fairly large changes when Trinity River water was transferred to replace West Fork San Jacinto River streamflow. Algal biomass showed large decreases when Trinity River water was transferred to augment East Fork Lake Houston streamflow and large increases when Trinity River water was transferred to replace West Fork San Jacinto River streamflow. Regardless of the scenario simulated, the model indicated that light was the limiting factor for algal biomass growth.

Effects of rainbow trout fry of a metals-contaminated diet of benthic invertebrates from the Clark Fork River, Montana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woodward, D.F.; Brumbaugh, W.G.; DeLonay, A.J.

1994-01-01

The upper Clark Fork River in northwestern Montana has received mining wastes from the Butte and Anaconda areas since 1880. These wastes have contaminated areas of the river bed and floodplain with tailings and heavy metal sludge, resulting in elevated concentration of metals in surface water, sediments, and biota. Rainbow trout Oncorhynchus mykiss were exposed immediately after hatching for 91 d to cadmium, copper, lead, and zinc in water at concentrations simulating those in Clark Fork River. From exogenous feeding (21 d posthatch) through 91 d, fry were also fed benthic invertebrates from the Clark Fork River that contained elevatedmore » concentrations of arsenic, cadmium, copper, and lead. Evaluations of different combinations of diet and water exposure indicated diet-borne metals were more important than water-borne metals - at the concentrations we tested - in reducing survival and growth of rainbow trout. Whole-body metal concentrations ([mu]g/g, wet weight) at 91 d in fish fed Clark Fork invertebrates without exposure to Clark Fork water were arsenic, 1.4; cadmium, 0.16; and copper, 6.7. These were similar to concentrations found in Clark Fork River fishes. Livers from fish on the high-metals diets exhibited degenerative changes and generally lacked glycogen vacuolation. Indigenous Clark Fork River invertebrates provide a concentrated source of metals for accumulation into young fishes, and probably were the cause of decreased survival and growth of age-0 rainbow trout in our laboratory exposures. 30 refs., 8 figs., 4 tabs.« less

76 FR 53082 - Proposed Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-25

..., 201 Saint Andrews Street, Tarboro, NC 27886. Smith County, Texas, and Incorporated Areas Black Fork.... Tributary BF-1 At the Black Fork Creek +434 +436 City of Tyler, confluence. Unincorporated Areas of Smith County. Approximately 1.2 miles None +476 upstream of Loop 323. Tributary BF-M-1 At the Black Fork Creek...

11. DETAIL VIEW OF BRIDGE DATEPLATE AT SOUTHEAST CORNER OF ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. DETAIL VIEW OF BRIDGE DATEPLATE AT SOUTHEAST CORNER OF BRIDGE WHICH READS 'NORTH FORK OF WHITE RIVER, VINCENNES STEEL CORP., CONTRACTOR, ARKANSAS STATE HIGHWAY COMMISSION AND THE UNITED STATES BUREAU OF PUBLIC ROADS, 1936' - North Fork Bridge, Spans North Fork of White River at State Highway 5, Norfork, Baxter County, AR

With deck removed and critical members severed, the bridge begins ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

With deck removed and critical members severed, the bridge begins to succumb to tractors, pulling cables attached to its downstream side. View is to the southeast from confluence of Trinity and South Fork Trinity Rivers - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

Spray and dust hang in the air, as the demolition ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Spray and dust hang in the air, as the demolition is completed. Only the southeast pier remains standing at right. View is to southeast from confluence of Trinity and South Fork Trinity Rivers - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

76 FR 70397 - Proposed Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-14

... the Ohio River +549 +550 Town of Fort Gay, Unincorporated Areas of Wayne County. confluence. At the... of Fort Gay. Fork). confluence to approximately 1.1 miles upstream of the Tug Fork confluence. Tug Fork At the Big Sandy River +576 +575 Town of Fort Gay. confluence. Approximately 0.5 mile +577 +575...

Integrating Salmon Recovery, Clean Water Act Compliance, Restoration, and Climate Change Impacts in the South Fork Nooksack River

EPA Science Inventory

"The South Fork Nooksack River (SFNR) is an important tributary to the Nooksack River, Bellingham Bay, and the Salish Sea. The South Fork Nooksack River comprises one of the 22 independent populations of spring Chinook in the Puget Sound Chinook Evolutionarily Significant Un...

76 FR 46721 - Salmon-Challis National Forest, ID; Upper North Fork HFRA Ecosystem Restoration Project...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-03

...-Challis National Forest, ID; Upper North Fork HFRA Ecosystem Restoration Project Environmental Impact... improve the health of the ecosystem and reach the desired future condition. DATES: Comments concerning the... Ecosystem Restoration Project EIS, P.O. Box 180, 11 Casey Rd., North Fork, ID 83466. Comments may also be...

75 FR 57493 - Notice of Inventory Completion: Department of Anthropology & Ethnic Studies, University of Nevada...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-21

..., Nevada; Shoshone-Paiute Tribes of the Duck Valley Reservation, Nevada; South Fork Band (Constituent Band... of Idaho; Shoshone-Paiute Tribes of the Duck Valley Reservation, Nevada; South Fork Band (Constituent... Idaho; Shoshone-Paiute Tribes of the Duck Valley Reservation, Nevada; South Fork Band; Summit Lake...

76 FR 35009 - Draft Oil and Gas Management Plan/Environmental Impact Statement for Big South Fork National...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-15

... DEPARTMENT OF THE INTERIOR National Park Service [5130-0400-NZM] Draft Oil and Gas Management Plan... Management Plan/ Environmental Impact Statement for Big South Fork National River and Recreation Area and... gas management plan/environmental impact statement (OGMP/DEIS) for the proposed Big South Fork...

Training Guidelines: Fork Lift Truck Driving.

ERIC Educational Resources Information Center

Ceramics, Glass, and Mineral Products Industry Training Board, Harrow (England).

This manual of operative training guidelines for fork lift truck driving has been developed by the Ceramics, Glass and Mineral Products Industry Training Board (Great Britain) in consultation with a number of firms which manufacture fork lift trucks or which already have training--programs for their use. The purpose of the guidelines is to assist…

HOWARD FORK ACID ROCK DRAINAGE SOURCE INTERCEPTION STUDY; HOWARD FORK OF THE SAN MIGUEL RIVER NEAR OPHIR, COLORADO

EPA Science Inventory

This project proposes to analyze regional hydrogeology as it relates to mine workings which discharge significant heavy metals into the Howard Fork of the San Miguel River and recommend strategies to intercept and divert water away from mineralized zones. The study also includes...

Chk1 promotes replication fork progression by controlling replication initiation

PubMed Central

Petermann, Eva; Woodcock, Mick; Helleday, Thomas

2010-01-01

DNA replication starts at initiation sites termed replication origins. Metazoan cells contain many more potential origins than are activated (fired) during each S phase. Origin activation is controlled by the ATR checkpoint kinase and its downstream effector kinase Chk1, which suppresses origin firing in response to replication blocks and during normal S phase by inhibiting the cyclin-dependent kinase Cdk2. In addition to increased origin activation, cells deficient in Chk1 activity display reduced rates of replication fork progression. Here we investigate the causal relationship between increased origin firing and reduced replication fork progression. We use the Cdk inhibitor roscovitine or RNAi depletion of Cdc7 to inhibit origin firing in Chk1-inhibited or RNAi-depleted cells. We report that Cdk inhibition and depletion of Cdc7 can alleviate the slow replication fork speeds in Chk1-deficient cells. Our data suggest that increased replication initiation leads to slow replication fork progression and that Chk1 promotes replication fork progression during normal S phase by controlling replication origin activity. PMID:20805465

Poly(ADP-ribose) binding to Chk1 at stalled replication forks is required for S-phase checkpoint activation

NASA Astrophysics Data System (ADS)

Min, Wookee; Bruhn, Christopher; Grigaravicius, Paulius; Zhou, Zhong-Wei; Li, Fu; Krüger, Anja; Siddeek, Bénazir; Greulich, Karl-Otto; Popp, Oliver; Meisezahl, Chris; Calkhoven, Cornelis F.; Bürkle, Alexander; Xu, Xingzhi; Wang, Zhao-Qi

2013-12-01

Damaged replication forks activate poly(ADP-ribose) polymerase 1 (PARP1), which catalyses poly(ADP-ribose) (PAR) formation; however, how PARP1 or poly(ADP-ribosyl)ation is involved in the S-phase checkpoint is unknown. Here we show that PAR, supplied by PARP1, interacts with Chk1 via a novel PAR-binding regulatory (PbR) motif in Chk1, independent of ATR and its activity. iPOND studies reveal that Chk1 associates readily with the unperturbed replication fork and that PAR is required for efficient retention of Chk1 and phosphorylated Chk1 at the fork. A PbR mutation, which disrupts PAR binding, but not the interaction with its partners Claspin or BRCA1, impairs Chk1 and the S-phase checkpoint activation, and mirrors Chk1 knockdown-induced hypersensitivity to fork poisoning. We find that long chains, but not short chains, of PAR stimulate Chk1 kinase activity. Collectively, we disclose a previously unrecognized mechanism of the S-phase checkpoint by PAR metabolism that modulates Chk1 activity at the replication fork.

Role of replication protein A as sensor in activation of the S-phase checkpoint in Xenopus egg extracts

PubMed Central

Recolin, Bénédicte; Van Der Laan, Siem; Maiorano, Domenico

2012-01-01

Uncoupling between DNA polymerases and helicase activities at replication forks, induced by diverse DNA lesions or replication inhibitors, generate long stretches of primed single-stranded DNA that is implicated in activation of the S-phase checkpoint. It is currently unclear whether nucleation of the essential replication factor RPA onto this substrate stimulates the ATR-dependent checkpoint response independently of its role in DNA synthesis. Using Xenopus egg extracts to investigate the role of RPA recruitment at uncoupled forks in checkpoint activation we have surprisingly found that in conditions in which DNA synthesis occurs, RPA accumulation at forks stalled by either replication stress or UV irradiation is dispensable for Chk1 phosphorylation. In contrast, when both replication fork uncoupling and RPA hyperloading are suppressed, Chk1 phosphorylation is inhibited. Moreover, we show that extracts containing reduced levels of RPA accumulate ssDNA and induce spontaneous, caffeine-sensitive, Chk1 phosphorylation in S-phase. These results strongly suggest that disturbance of enzymatic activities of replication forks, rather than RPA hyperloading at stalled forks, is a critical determinant of ATR activation. PMID:22187152

Water-Quality, Bed-Sediment, and Biological Data (October 2007 through September 2008) and Statistical Summaries of Long-Term Data for Streams in the Clark Fork Basin, Montana

USGS Publications Warehouse

Dodge, Kent A.; Hornberger, Michelle I.; Dyke, Jessica

2009-01-01

Water, bed sediment, and biota were sampled in streams from Butte to near Missoula as part of a long-term monitoring program in the upper Clark Fork basin; additional water samples were collected in the Clark Fork basin from sites near Missoula downstream to near the confluence of the Clark Fork and Flathead River as part of a supplemental sampling program. The sampling programs were conducted in cooperation with the U.S. Environmental Protection Agency to characterize aquatic resources in the Clark Fork basin of western Montana, with emphasis on trace elements associated with historic mining and smelting activities. Sampling sites were located on the Clark Fork and selected tributaries. Water samples were collected periodically at 23 sites from October 2007 through September 2008. Bed-sediment and biota samples were collected once at 13 sites during August 2008. This report presents the analytical results and quality assurance data for water-quality, bed-sediment, and biota samples collected at all long-term and supplemental monitoring sites from October 2007 through September 2008. Water-quality data include concentrations of selected major ions, trace elements, and suspended sediment. Turbidity was analyzed for water samples collected at sites where seasonal daily values of turbidity were being determined and at Clark Fork above Missoula. Nutrients also were analyzed at all the supplemental water-quality sites, except for Clark Fork Bypass, near Bonner. Daily values of suspended-sediment concentration and suspended-sediment discharge were determined for four sites, and seasonal daily values of turbidity were determined for four sites. Bed-sediment data include trace-element concentrations in the fine-grained fraction. Biological data include trace-element concentrations in whole-body tissue of aquatic benthic insects. Statistical summaries of long-term water-quality, bed-sediment, and biological data for sites in the upper Clark Fork basin are provided for the period of record since 1985.

Water-quality, bed-sediment, and biological data (October 2008 through September 2009) and statistical summaries of long-term data for streams in the Clark Fork basin, Montana

USGS Publications Warehouse

Dodge, Kent A.; Hornberger, Michelle I.; Dyke, Jessica

2010-01-01

Water, bed sediment, and biota were sampled in streams from Butte to near Missoula, Montana, as part of a long-term monitoring program in the upper Clark Fork basin; additional water samples were collected in the Clark Fork basin from sites near Missoula downstream to near the confluence of the Clark Fork and Flathead River as part of a supplemental sampling program. The sampling programs were conducted by the U.S. Geological Survey in cooperation with the U.S. Environmental Protection Agency to characterize aquatic resources in the Clark Fork basin of western Montana, with emphasis on trace elements associated with historic mining and smelting activities. Sampling sites were located on the Clark Fork and selected tributaries. Water samples were collected periodically at 24 sites from October 2008 through September 2009. Bed-sediment and biota samples were collected once at 13 sites during August 2009. This report presents the analytical results and quality-assurance data for water-quality, bed-sediment, and biota samples collected at all long-term and supplemental monitoring sites from October 2008 through September 2009. Water-quality data include concentrations of selected major ions, trace elements, and suspended sediment. Turbidity was analyzed for water samples collected at the four sites where seasonal daily values of turbidity were being determined as well as at Clark Fork above Missoula. Nutrients also were analyzed at all the supplemental water-quality sites, except for Clark Fork Bypass, near Bonner. Daily values of suspended-sediment concentration and suspended-sediment discharge were determined for four sites. Bed-sediment data include trace-element concentrations in the fine-grained fraction. Biological data include trace-element concentrations in whole-body tissue of aquatic benthic insects. Statistical summaries of long-term water-quality, bed-sediment, and biological data for sites in the upper Clark Fork basin are provided for the period of record since 1985.

The Human RNA Polymerase I Transcription Terminator Complex Acts as a Replication Fork Barrier That Coordinates the Progress of Replication with rRNA Transcription Activity.

PubMed

Akamatsu, Yufuko; Kobayashi, Takehiko

2015-05-01

In S phase, the replication and transcription of genomic DNA need to accommodate each other, otherwise their machineries collide, with chromosomal instability as a possible consequence. Here, we characterized the human replication fork barrier (RFB) that is present downstream from the 47S pre-rRNA gene (ribosomal DNA [rDNA]). We found that the most proximal transcription terminator, Sal box T1, acts as a polar RFB, while the other, Sal box T4/T5, arrests replication forks bidirectionally. The fork-arresting activity at these sites depends on polymerase I (Pol I) transcription termination factor 1 (TTF-1) and a replisome component, TIMELESS (TIM). We also found that the RFB activity was linked to rDNA copies with hypomethylated CpG and coincided with the time that actively transcribed rRNA genes are replicated. Failed fork arrest at RFB sites led to a slowdown of fork progression moving in the opposite direction to rRNA transcription. Chemical inhibition of transcription counteracted this deceleration of forks, indicating that rRNA transcription impedes replication in the absence of RFB activity. Thus, our results reveal a role of RFB for coordinating the progression of replication and transcription activity in highly transcribed rRNA genes. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

The Replisome-Coupled E3 Ubiquitin Ligase Rtt101Mms22 Counteracts Mrc1 Function to Tolerate Genotoxic Stress

PubMed Central

Melnik, Andre; Wilson-Zbinden, Caroline; Schellhaas, René; Kastner, Lisa; Piwko, Wojciech; Dees, Martina; Picotti, Paola; Maric, Marija; Labib, Karim; Luke, Brian; Peter, Matthias

2016-01-01

Faithful DNA replication and repair requires the activity of cullin 4-based E3 ubiquitin ligases (CRL4), but the underlying mechanisms remain poorly understood. The budding yeast Cul4 homologue, Rtt101, in complex with the linker Mms1 and the putative substrate adaptor Mms22 promotes progression of replication forks through damaged DNA. Here we characterized the interactome of Mms22 and found that the Rtt101Mms22 ligase associates with the replisome progression complex during S-phase via the amino-terminal WD40 domain of Ctf4. Moreover, genetic screening for suppressors of the genotoxic sensitivity of rtt101Δ cells identified a cluster of replication proteins, among them a component of the fork protection complex, Mrc1. In contrast to rtt101Δ and mms22Δ cells, mrc1Δ rtt101Δ and mrc1Δ mms22Δ double mutants complete DNA replication upon replication stress by facilitating the repair/restart of stalled replication forks using a Rad52-dependent mechanism. Our results suggest that the Rtt101Mms22 E3 ligase does not induce Mrc1 degradation, but specifically counteracts Mrc1’s replicative function, possibly by modulating its interaction with the CMG (Cdc45-MCM-GINS) complex at stalled forks. PMID:26849847

Quartz-enhanced photo-acoustic spectroscopy for breath analyses

NASA Astrophysics Data System (ADS)

Petersen, Jan C.; Lamard, Laurent; Feng, Yuyang; Focant, Jeff-F.; Peremans, Andre; Lassen, Mikael

2017-03-01

An innovative and novel quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor for highly sensitive and selective breath gas analysis is introduced. The QEPAS sensor consists of two acoustically coupled micro- resonators (mR) with an off-axis 20 kHz quartz tuning fork (QTF). The complete acoustically coupled mR system is optimized based on finite element simulations and experimentally verified. Due to the very low fabrication costs the QEPAS sensor presents a clear breakthrough in the field of photoacoustic spectroscopy by introducing novel disposable gas chambers in order to avoid cleaning after each test. The QEPAS sensor is pumped resonantly by a nanosecond pulsed single-mode mid-infrared optical parametric oscillator (MIR OPO). Spectroscopic measurements of methane and methanol in the 3.1 μm to 3.7 μm wavelength region is conducted. Demonstrating a resolution bandwidth of 1 cm-1. An Allan deviation analysis shows that the detection limit at optimum integration time for the QEPAS sensor is 32 ppbv@190s for methane and that the background noise is solely due to the thermal noise of the QTF. Spectra of both individual molecules as well as mixtures of molecules were measured and analyzed. The molecules are representative of exhaled breath gasses that are bio-markers for medical diagnostics.

Single & Multiprobe Apertureless Thermal Imaging of Electromagnetic Excitation Over A Wide Range of Wavelengths

NASA Astrophysics Data System (ADS)

Dekhter, Rimma; Lewis, Aaron; Kokotov, Sophia; Hamra, Patricia; Fleischman, Boaz; Taha, Hesham

2013-03-01

Near-field optical effects have generally been detected using photodetectors. There are no reports on the use of the temperature changes caused by electromagnetic radiation using thermal sensing probes for scanned probe microscopy. In this paper we apply our development of such probes to monitor the effects of electromagnetic radiation at a number of different wavelengths using the heating caused in a sample by specific wavelengths and their propagation. The paper will catalogue effects over a wide spectrum of wavelengths from the near to mid infrared. The thermal sensing probes are based on glass nanopipettes that have metal wires that make a contact at the very tip of a tapered glass structure. These probes are cantilevered and use normal force tuning fork methodology to bring them either into contact or near-contact since this feedback method has no jump to contact instability associated with it. Data will be shown that defines the resolution of such thermal sensing to at least the 32 nm level. In addition the probes have the important attribute of having a highly exposed tip that allows for either optical sensing methodologies with a lens either from directly above or below or heat sensing with a single or additional probe in a multiprobe scanning probe system.

Development and calibration of a compact self-sensing atomic force microscope head for micro-nano characterization

NASA Astrophysics Data System (ADS)

Guo, Tong; Wang, Siming; Zhao, Jian; Chen, Jinping; Fu, Xing; Hu, Xiaotang

2011-12-01

A compact self-sensing atomic force microscope (AFM) head is developed for the micro-nano dimensional measurement. This AFM head works in tapping mode equipped with a commercial self-sensing probe. This kind of probe can benefit not only from the tuning fork's stable resonant frequency and high quality factor but also from the silicon cantilever's reasonable spring constant. The head is convenient to operate by its simplicity of structure, since it does not need any optical detector to measure the bending of the cantilever. The compact structure makes the head ease to combine with other measuring methods. According to the probe"s characteristics, a method is proposed to quickly calculate the cantilever"s resonance amplitude through measuring its electro-mechanical coupling factor. An experiment system is established based on the nano-measuring machine (NMM) as a high precision positioning stage. Using this system, the approach/retract test is carried out for calibrating the head. The tests can be traced to the meter definition by interferometers in NMM. Experimental results show that the non-linearity error of this AFM head is smaller than 1%, the sensitivity reaches 0.47nm/mV and the measurement stroke is several hundreds of nanometers.

True Tapping Mode Scanning Near-Field Optical Microscopy with Bent Glass Fiber Probes

PubMed Central

Yasinskii, V. M.; Filimonenko, D. S.; Rostova, E.; Dietler, G.; Sekatskii, S. K.

2018-01-01

In scanning near-field optical microscopy, the most popular probes are made of sharpened glass fiber attached to a quartz tuning fork (TF) and exploiting the shear force-based feedback. The use of tapping mode feedback could be preferable. Such an approach can be realized, for example, using bent fiber probes. Detailed analysis of fiber vibration modes shows that realization of truly tapping mode of the probe dithering requires an extreme caution. In case of using the second resonance mode, probes vibrate mostly in shear force mode unless the bending radius is rather small (ca. 0.3 mm) and the probe's tip is short. Otherwise, the shear force character of the dithering persists. Probes having these characteristics were prepared by irradiation of a tapered etched glass fiber with a CW CO2 laser. These probes were attached to the TF in double resonance conditions which enables achieving significant quality factor (4000–6000) of the TF + probe system (Cherkun et al., 2006). We also show that, to achieve a truly tapping character, dithering, short, and not exceeding 3 mm lengths of a freestanding part of bent fiber probe beam should also be used in the case of nonresonant excitation. PMID:29849857

Development of a Hybrid Atomic Force Microscopic Measurement System Combined with White Light Scanning Interferometry

PubMed Central

Guo, Tong; Wang, Siming; Dorantes-Gonzalez, Dante J.; Chen, Jinping; Fu, Xing; Hu, Xiaotang

2012-01-01

A hybrid atomic force microscopic (AFM) measurement system combined with white light scanning interferometry for micro/nanometer dimensional measurement is developed. The system is based on a high precision large-range positioning platform with nanometer accuracy on which a white light scanning interferometric module and an AFM head are built. A compact AFM head is developed using a self-sensing tuning fork probe. The head need no external optical sensors to detect the deflection of the cantilever, which saves room on the head, and it can be directly fixed under an optical microscopic interferometric system. To enhance the system’s dynamic response, the frequency modulation (FM) mode is adopted for the AFM head. The measuring data can be traceable through three laser interferometers in the system. The lateral scanning range can reach 25 mm × 25 mm by using a large-range positioning platform. A hybrid method combining AFM and white light scanning interferometry is proposed to improve the AFM measurement efficiency. In this method, the sample is measured firstly by white light scanning interferometry to get an overall coarse morphology, and then, further measured with higher resolution by AFM. Several measuring experiments on standard samples demonstrate the system’s good measurement performance and feasibility of the hybrid measurement method. PMID:22368463

Development of a hybrid atomic force microscopic measurement system combined with white light scanning interferometry.

PubMed

Guo, Tong; Wang, Siming; Dorantes-Gonzalez, Dante J; Chen, Jinping; Fu, Xing; Hu, Xiaotang

2012-01-01

A hybrid atomic force microscopic (AFM) measurement system combined with white light scanning interferometry for micro/nanometer dimensional measurement is developed. The system is based on a high precision large-range positioning platform with nanometer accuracy on which a white light scanning interferometric module and an AFM head are built. A compact AFM head is developed using a self-sensing tuning fork probe. The head need no external optical sensors to detect the deflection of the cantilever, which saves room on the head, and it can be directly fixed under an optical microscopic interferometric system. To enhance the system's dynamic response, the frequency modulation (FM) mode is adopted for the AFM head. The measuring data can be traceable through three laser interferometers in the system. The lateral scanning range can reach 25 mm × 25 mm by using a large-range positioning platform. A hybrid method combining AFM and white light scanning interferometry is proposed to improve the AFM measurement efficiency. In this method, the sample is measured firstly by white light scanning interferometry to get an overall coarse morphology, and then, further measured with higher resolution by AFM. Several measuring experiments on standard samples demonstrate the system's good measurement performance and feasibility of the hybrid measurement method.

A near-field scanning microwave microscope based on a superconducting resonator for low power measurements.

PubMed

de Graaf, S E; Danilov, A V; Adamyan, A; Kubatkin, S E

2013-02-01

We report on the design and performance of a cryogenic (300 mK) near-field scanning microwave microscope. It uses a microwave resonator as the near-field sensor, operating at a frequency of 6 GHz and microwave probing amplitudes down to 100 μV, approaching low enough photon population (N ∼ 1000) of the resonator such that coherent quantum manipulation becomes feasible. The resonator is made out of a miniaturized distributed fractal superconducting circuit that is integrated with the probing tip, micromachined to be compact enough such that it can be mounted directly on a quartz tuning-fork, and used for parallel operation as an atomic force microscope (AFM). The resonator is magnetically coupled to a transmission line for readout, and to achieve enhanced sensitivity we employ a Pound-Drever-Hall measurement scheme to lock to the resonance frequency. We achieve a well localized near-field around the tip such that the microwave resolution is comparable to the AFM resolution, and a capacitive sensitivity down to 6.4 × 10(-20) F/Hz, limited by mechanical noise. We believe that the results presented here are a significant step towards probing quantum systems at the nanoscale using near-field scanning microwave microscopy.

Combined low-temperature scanning tunneling/atomic force microscope for atomic resolution imaging and site-specific force spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwarz, Udo; Albers, Boris J.; Liebmann, Marcus

2008-02-27

The authors present the design and first results of a low-temperature, ultrahigh vacuum scanning probe microscope enabling atomic resolution imaging in both scanning tunneling microscopy (STM) and noncontact atomic force microscopy (NC-AFM) modes. A tuning-fork-based sensor provides flexibility in selecting probe tip materials, which can be either metallic or nonmetallic. When choosing a conducting tip and sample, simultaneous STM/NC-AFM data acquisition is possible. Noticeable characteristics that distinguish this setup from similar systems providing simultaneous STM/NC-AFM capabilities are its combination of relative compactness (on-top bath cryostat needs no pit), in situ exchange of tip and sample at low temperatures, short turnaroundmore » times, modest helium consumption, and unrestricted access from dedicated flanges. The latter permits not only the optical surveillance of the tip during approach but also the direct deposition of molecules or atoms on either tip or sample while they remain cold. Atomic corrugations as low as 1 pm could successfully be resolved. In addition, lateral drifts rates of below 15 pm/h allow long-term data acquisition series and the recording of site-specific spectroscopy maps. Results obtained on Cu(111) and graphite illustrate the microscope's performance.« less

76 FR 34690 - Placer County Water Agency; Notice of Application Accepted for Filing, Soliciting Motions To...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-14

... Water Agency; Notice of Application Accepted for Filing, Soliciting Motions To Intervene and Protests... Water Agency. e. Name of Project: Middle Fork American River Project. f. Location: The Middle Fork....S. Department of Agriculture-- Forest Service. g. Filed Pursuant to: Federal Power Act 16 U.S.C. 791...

Qualitative Assessment: Evaluating the Impacts of Climate Change on Endangered Species Act Recovery Actions for the South Fork Nooksack River, WA

EPA Science Inventory

The South Fork Nooksack River (South Fork) is located in northwest Washington State and is home to nine species of Pacific salmon, including Nooksack early Chinook (aka, spring Chinook salmon), an iconic species for the Nooksack Indian Tribe. The quantity of salmon in the South F...

33 CFR 165.552 - Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey. 165.552 Section 165.552 Navigation and Navigable... Coast Guard District § 165.552 Security Zone; Oyster Creek Generation Station, Forked River, Ocean...

33 CFR 165.552 - Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey. 165.552 Section 165.552 Navigation and Navigable... Coast Guard District § 165.552 Security Zone; Oyster Creek Generation Station, Forked River, Ocean...

33 CFR 165.552 - Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey. 165.552 Section 165.552 Navigation and Navigable... Coast Guard District § 165.552 Security Zone; Oyster Creek Generation Station, Forked River, Ocean...

33 CFR 165.552 - Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey. 165.552 Section 165.552 Navigation and Navigable... Coast Guard District § 165.552 Security Zone; Oyster Creek Generation Station, Forked River, Ocean...

33 CFR 165.552 - Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Security Zone; Oyster Creek Generation Station, Forked River, Ocean County, New Jersey. 165.552 Section 165.552 Navigation and Navigable... Coast Guard District § 165.552 Security Zone; Oyster Creek Generation Station, Forked River, Ocean...

76 FR 35909 - Temporary Concession Contract for Big South Fork National Recreation Area, TN/KY

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-20

... Recreation Area, TN/KY. SUMMARY: Pursuant to 36 CFR 51.24, public notice is hereby given that the National... Concession Contract for Big South Fork National Recreation Area, TN/KY AGENCY: National Park Service... services within Big South Fork National Recreation Area, Tennessee and Kentucky, for a term not to exceed 3...

9. 'CRIB DAM IN LAKE FORK RIVER AT HEADING OF ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. 'CRIB DAM IN LAKE FORK RIVER AT HEADING OF LAKE FORK CANAL, UINTAH PROJECT. TWO SLUICEWAYS TWENTY FEET WIDE HAVE BEEN LEFT IN THE DAM TO PASS BOULDERS DURING HIGH WATER. THESE SLUICEWAYS ARE CLOSED BY LOGS AND HAY DURING LOW WATER.' Date unknown - Irrigation Canals in the Uinta Basin, Duchesne, Duchesne County, UT

16 CFR 1512.14 - Requirements for fork and frame assembly.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 16 Commercial Practices 2 2011-01-01 2011-01-01 false Requirements for fork and frame assembly... assembly. The fork and frame assembly shall be tested for strength by application of a load of 890 N (200 lbf) or at least 39.5 J (350 in-lb) of energy, whichever results in the greater force, in accordance...

16 CFR 1512.14 - Requirements for fork and frame assembly.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 16 Commercial Practices 2 2014-01-01 2014-01-01 false Requirements for fork and frame assembly... assembly. The fork and frame assembly shall be tested for strength by application of a load of 890 N (200 lbf) or at least 39.5 J (350 in-lb) of energy, whichever results in the greater force, in accordance...

16 CFR 1512.14 - Requirements for fork and frame assembly.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Requirements for fork and frame assembly... assembly. The fork and frame assembly shall be tested for strength by application of a load of 890 N (200 lbf) or at least 39.5 J (350 in-lb) of energy, whichever results in the greater force, in accordance...

16 CFR 1512.14 - Requirements for fork and frame assembly.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 16 Commercial Practices 2 2012-01-01 2012-01-01 false Requirements for fork and frame assembly... assembly. The fork and frame assembly shall be tested for strength by application of a load of 890 N (200 lbf) or at least 39.5 J (350 in-lb) of energy, whichever results in the greater force, in accordance...

Utilization of protein expression profiles as indicators of environmental impairment of smallmouth bass (Micropterus dolomieu) from the Shenandoah River, Virginia, USA.

PubMed

Ripley, Jennifer; Iwanowicz, Luke; Blazer, Vicki; Foran, Christy

2008-08-01

The Shenandoah River (VA, USA), the largest tributary of the Potomac River (MD, USA) and an important source of drinking water, has been the site of extensive fish kills since 2004. Previous investigations indicate environmental stressors may be adversely modulating the immune system of smallmouth bass (Micropterus dolomieu) and other species. Anterior kidney (AK) tissue, the major site of blood cell production in fish, was collected from smallmouth bass at three sites along the Shenandoah River. The tissue was divided for immune function and proteomics analyses. Bactericidal activity and respiratory burst were significantly different between North Fork and mainstem Shenandoah River smallmouth bass, whereas South Fork AK tissue did not significantly differ in either of these measures compared with the other sites. Cytotoxic cell activity was highest among South Fork and lowest among North Fork AK leukocytes. The composite two-dimension gels of the North Fork and mainstem smallmouth bass AK tissues contained 584 and 591 spots, respectively. South Fork smallmouth bass AK expressed only 335 proteins. Nineteen of 50 proteins analyzed by matrix-assisted laser desorption ionization-time of flight were successfully identified. Three of the four identified proteins with increased expression in South Fork AK tissue were involved in metabolism. Seven proteins exclusive to mainstem and North Fork smallmouth bass AK and expressed at comparable abundances serve immune and stress response functions. The proteomics data indicate these fish differ in metabolic capacity of AK tissue and in the ability to produce functional leukocytes. The variable responses of the immune function assays further indicate disruption to the immune system. Our results allow us to hypothesize underlying physiological changes that may relate to fish kills and suggest relevant contaminants known to produce similar physiological disruption.

Utilization of protein expression profiles as indicators of environmental impairment of smallmouth bass (Micropterus dolomieu) from the Shenandoah River, Virginia, USA

USGS Publications Warehouse

Ripley, J.; Iwanowicz, L.; Blazer, V.; Foran, C.

2008-01-01

The Shenandoah River (VA, USA), the largest tributary of the Potomac River (MD, USA) and an important source of drinking water, has been the site of extensive fish kills since 2004. Previous investigations indicate environmental stressors may be adversely modulating the immune system of smallmouth bass (Micropterus dolomieu) and other species. Anterior kidney (AK) tissue, the major site of blood cell production in fish, was collected from smallmouth bass at three sites along the Shenandoah River. The tissue was divided for immune function and proteomics analyses. Bactericidal activity and respiratory burst were significantly different between North Fork and mainstem Shenandoah River smallmouth bass, whereas South Fork AK tissue did not significantly differ in either of these measures compared with the other sites. Cytotoxic cell activity was highest among South Fork and lowest among North Fork AK leukocytes. The composite two-dimension gels of the North Fork and mainstem smallmouth bass AK tissues contained 584 and 591 spots, respectively. South Fork smallmouth bass AK expressed only 335 proteins. Nineteen of 50 proteins analyzed by matrix-assisted laser desorption ionization-time of flight were successfully identified. Three of the four identified proteins with increased expression in South Fork AK tissue were involved in metabolism. Seven proteins exclusive to mainstem and North Fork smallmouth bass AK and expressed at comparable abundances serve immune and stress response functions. The proteomics data indicate these fish differ in metabolic capacity of AK tissue and in the ability to produce functional leukocytes. The variable responses of the immune function assays further indicate disruption to the immune system. Our results allow us to hypothesize underlying physiological changes that may relate to fish kills and suggest relevant contaminants known to produce similar physiological disruption. ?? 2008 SETAC.

U.S. Geological Survey 2013 assessment of undiscovered resources in the Bakken and Three Forks Formations of the U.S. Williston Basin Province

USGS Publications Warehouse

Gaswirth, Stephanie B.; Marra, Kristen R.

2014-01-01

The Upper Devonian Three Forks and Upper Devonian to Lower Mississippian Bakken Formations comprise a major United States continuous oil resource. Current exploitation of oil is from horizontal drilling and hydraulic fracturing of the Middle Member of the Bakken and upper Three Forks, with ongoing exploration of the lower Three Forks, and the Upper, Lower, and Pronghorn Members of the Bakken Formation. In 2008, the U.S. Geological Survey (USGS) estimated a mean of 3.65 billion bbl of undiscovered, technically recoverable oil resource within the Bakken Formation. The USGS recently reassessed the Bakken Formation, which included an assessment of the underlying Three Forks Formation. The Pronghorn Member of the Bakken Formation, where present, was included as part of the Three Forks assessment due to probable fluid communication between reservoirs. For the Bakken Formation, five continuous and one conventional assessment units (AUs) were defined. These AUs are modified from the 2008 AU boundaries to incorporate expanded geologic and production information. The Three Forks Formation was defined with one continuous and one conventional AU. Within the continuous AUs, optimal regions of hydrocarbon recovery, or “sweet spots,” were delineated and estimated ultimate recoveries were calculated for each continuous AU. Resulting undiscovered, technically recoverable resource estimates were 3.65 billion bbl for the five Bakken continuous oil AUs and 3.73 billion bbl for the Three Forks Continuous Oil AU, generating a total mean resource estimate of 7.38 billion bbl. The two conventional AUs are hypothetical and represent a negligible component of the total estimated resource (8 million barrels of oil).

ATR prohibits replication catastrophe by preventing global exhaustion of RPA.

PubMed

Toledo, Luis Ignacio; Altmeyer, Matthias; Rask, Maj-Britt; Lukas, Claudia; Larsen, Dorthe Helena; Povlsen, Lou Klitgaard; Bekker-Jensen, Simon; Mailand, Niels; Bartek, Jiri; Lukas, Jiri

2013-11-21

ATR, activated by replication stress, protects replication forks locally and suppresses origin firing globally. Here, we show that these functions of ATR are mechanistically coupled. Although initially stable, stalled forks in ATR-deficient cells undergo nucleus-wide breakage after unscheduled origin firing generates an excess of single-stranded DNA that exhausts the nuclear pool of RPA. Partial reduction of RPA accelerated fork breakage, and forced elevation of RPA was sufficient to delay such "replication catastrophe" even in the absence of ATR activity. Conversely, unscheduled origin firing induced breakage of stalled forks even in cells with active ATR. Thus, ATR-mediated suppression of dormant origins shields active forks against irreversible breakage via preventing exhaustion of nuclear RPA. This study elucidates how replicating genomes avoid destabilizing DNA damage. Because cancer cells commonly feature intrinsically high replication stress, this study also provides a molecular rationale for their hypersensitivity to ATR inhibitors. Copyright © 2013 Elsevier Inc. All rights reserved.

DETAIL VIEW OF BASE OF CAST IRON TOWER SHOWING THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DETAIL VIEW OF BASE OF CAST IRON TOWER SHOWING THE FABRICATING MARK OF STARBUCK IRON WORKS, TROY, NY - Bidwell Bar Suspension Bridge & Stone Toll House, Near Lake Oroville (moved from fork of Feather River), Oroville, Butte County, CA

Habitat-dependent interactions between two size-classes of juvenile steelhead in a small stream

Treesearch

Bret C. Harvey; Rodney J. Nakamoto

1997-01-01

Abstract - The presence of small steelhead (Oncorhynchus mykiss; averaging 55 mm fork length) influenced the growth of larger juvenile steelhead (90 mm fork length) during a 6-week experiment conducted in North Fork Caspar Creek, California, in summer 1994. In fenced replicate deep stream sections in this small stream, growth of the larger steelhead was greater in...

Status of the Mussel Resource in Little South Fork Cumberland River

Treesearch

Melvin L. Warren; Wendell R. Haag; Brooks M. Burr

1999-01-01

As recently as the 198Os, the Little South Fork Cumberland River of southeastern Kentucky supported a diverse freshwater mussel fauna (Starnes and Bogan 1982; Appendix A). The Little South Fork represented one of the last rivers to support a high number of mussel species in the Cumberland River drainage of Kentucky and Tennessee. The river was first surveyed...

A watershed's response to logging and roads: South Fork of Caspar Creek, California, 1967-1976

Treesearch

Raymond M. Rice; Forest B. Tilley; Patricia A. Datzman

1979-01-01

The effect of logging and roadbuilding on erosion and sedimentation are analyzed by comparing the North Fork and South Fork of Caspar Creek, in northern California. Increased sediment production during the 4 years after road construction, was 326 cu yd/sq mi/yr—80 percent greater than that predicted by the predisturbance regression analysis. The average...

16 CFR § 1512.14 - Requirements for fork and frame assembly.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 16 Commercial Practices 2 2013-01-01 2013-01-01 false Requirements for fork and frame assembly. Â... assembly. The fork and frame assembly shall be tested for strength by application of a load of 890 N (200 lbf) or at least 39.5 J (350 in-lb) of energy, whichever results in the greater force, in accordance...

Input-form data for the U.S. Geological Survey assessment of the Devonian and Mississippian Bakken and Devonian Three Forks Formations of the U.S. Williston Basin Province, 2013

USGS Publications Warehouse

,; Gaswirth, Stephanie B.; Marra, Kristen R.; Cook, Troy A.; Charpentier, Ronald R.; Gautier, Donald L.; Higley, Debra K.; Klett, Timothy R.; Lewan, Michael D.; Lillis, Paul G.; Schenk, Christopher J.; Tennyson, Marilyn E.; Whidden, Katherine J.

2013-01-01

In 2013, the U.S. Geological Survey assessed the technically recoverable oil and gas resources of the Bakken and Three Forks Formations of the U.S. portion of the Williston Basin. The Bakken and Three Forks Formations were assessed as continuous and hypothetical conventional oil accumulations using a methodology similar to that used in the assessment of other continuous- and conventional-type assessment units throughout the United States. The purpose of this report is to provide supplemental documentation and information used in the Bakken-Three Forks assessment.

Evaluate Status of Pacific Lamprey in the Clearwater River Drainage, Idaho, Annual Report 2002.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cochnauer, Tim; Claire, Christopher

In 2002 Idaho Department of Fish and Game continued investigation into the status of Pacific lamprey populations in Idaho's Clearwater River drainage. Trapping, electrofishing, and spawning ground redd surveys were used to determine Pacific lamprey distribution, life history strategies, and habitat requirements in the South Fork Clearwater River, Lochsa River, Selway River, and Middle Fork Clearwater River subbasins. Five-hundred forty-one ammocoetes were captured electroshocking 70 sites in the South Fork Clearwater River, Lochsa River, Selway River, Middle Fork Clearwater River, Clearwater River, and their tributaries in 2002. Habitat utilization surveys in Red River support previous work indicating Pacific lamprey ammocoetemore » densities are greater in lateral scour pool habitats compared to riffles and rapids. Presence-absence survey findings in 2002 augmented 2000 and 2001 indicating Pacific lamprey macrothalmia and ammocoetes are not numerous or widely distributed. Pacific lamprey distribution was confined to the lower reaches of Red River below rkm 8.0, the South Fork Clearwater River, Lochsa River (Ginger Creek to mouth), Selway River (Race Creek to mouth), Middle Fork Clearwater River, and the Clearwater River (downstream to Potlatch River).« less

Acute inactivation of the replicative helicase in human cells triggers MCM8–9-dependent DNA synthesis

PubMed Central

Natsume, Toyoaki; Nishimura, Kohei; Minocherhomji, Sheroy; Bhowmick, Rahul; Hickson, Ian D.; Kanemaki, Masato T.

2017-01-01

DNA replication fork progression can be disrupted at difficult to replicate loci in the human genome, which has the potential to challenge chromosome integrity. This replication fork disruption can lead to the dissociation of the replisome and the formation of DNA damage. To model the events stemming from replisome dissociation during DNA replication perturbation, we used a degron-based system for inducible proteolysis of a subunit of the replicative helicase. We show that MCM2-depleted cells activate a DNA damage response pathway and generate replication-associated DNA double-strand breaks (DSBs). Remarkably, these cells maintain some DNA synthesis in the absence of MCM2, and this requires the MCM8–9 complex, a paralog of the MCM2–7 replicative helicase. We show that MCM8–9 functions in a homologous recombination-based pathway downstream from RAD51, which is promoted by DSB induction. This RAD51/MCM8–9 axis is distinct from the recently described RAD52-dependent DNA synthesis pathway that operates in early mitosis at common fragile sites. We propose that stalled replication forks can be restarted in S phase via homologous recombination using MCM8–9 as an alternative replicative helicase. PMID:28487407

Quantifying Impact of Chromosome Copy Number on Recombination in Escherichia coli.

PubMed

Reynolds, T Steele; Gill, Ryan T

2015-07-17

The ability to precisely and efficiently recombineer synthetic DNA into organisms of interest in a quantitative manner is a key requirement in genome engineering. Even though considerable effort has gone into the characterization of recombination in Escherichia coli, there is still substantial variability in reported recombination efficiencies. We hypothesized that this observed variability could, in part, be explained by the variability in chromosome copy number as well as the location of the replication forks relative to the recombination site. During rapid growth, E. coli cells may contain several pairs of open replication forks. While recombineered forks are resolving and segregating within the population, changes in apparent recombineering efficiency should be observed. In the case of dominant phenotypes, we predicted and then experimentally confirmed that the apparent recombination efficiency declined during recovery until complete segregation of recombineered and wild-type genomes had occurred. We observed the reverse trend for recessive phenotypes. The observed changes in apparent recombination efficiency were found to be in agreement with mathematical calculations based on our proposed mechanism. We also provide a model that can be used to estimate the total segregated recombination efficiency based on an initial efficiency and growth rate. These results emphasize the importance of employing quantitative strategies in the design of genome-scale engineering efforts.

Top2 and Sgs1-Top3 Act Redundantly to Ensure rDNA Replication Termination

PubMed Central

Fredsøe, Jacob; Nielsen, Ida; Pedersen, Jakob Madsen; Bentsen, Iben Bach; Lisby, Michael; Bjergbaek, Lotte; Andersen, Anni H

2015-01-01

Faithful DNA replication with correct termination is essential for genome stability and transmission of genetic information. Here we have investigated the potential roles of Topoisomerase II (Top2) and the RecQ helicase Sgs1 during late stages of replication. We find that cells lacking Top2 and Sgs1 (or Top3) display two different characteristics during late S/G2 phase, checkpoint activation and accumulation of asymmetric X-structures, which are both independent of homologous recombination. Our data demonstrate that checkpoint activation is caused by a DNA structure formed at the strongest rDNA replication fork barrier (RFB) during replication termination, and consistently, checkpoint activation is dependent on the RFB binding protein, Fob1. In contrast, asymmetric X-structures are formed independent of Fob1 at less strong rDNA replication fork barriers. However, both checkpoint activation and formation of asymmetric X-structures are sensitive to conditions, which facilitate fork merging and progression of replication forks through replication fork barriers. Our data are consistent with a redundant role of Top2 and Sgs1 together with Top3 (Sgs1-Top3) in replication fork merging at rDNA barriers. At RFB either Top2 or Sgs1-Top3 is essential to prevent formation of a checkpoint activating DNA structure during termination, but at less strong rDNA barriers absence of the enzymes merely delays replication fork merging, causing an accumulation of asymmetric termination structures, which are solved over time. PMID:26630413

Sediment transport and storage in North Fork Caspar Creek, Mendocino County, California: water years 1980-1988

Treesearch

Michael Brent Napolitano

1996-01-01

Abstract - The old-growth redwood forest of North Fork Caspar Creek was clear-cut between 1864 and 1904. Previous research on logging-related changes in suspended sediment and streamflow would suggest that North Fork Caspar Creek has recovered from historical logging (Rice et al., 1979; Ziemer, 1981); research on the influence of large woody debris (LWD) on channel...

Continuous water-quality monitoring and regression analysis to estimate constituent concentrations and loads in the Red River of the North at Fargo and Grand Forks, North Dakota, 2003-12

USGS Publications Warehouse

Galloway, Joel M.

2014-01-01

The Red River of the North (hereafter referred to as “Red River”) Basin is an important hydrologic region where water is a valuable resource for the region’s economy. Continuous water-quality monitors have been operated by the U.S. Geological Survey, in cooperation with the North Dakota Department of Health, Minnesota Pollution Control Agency, City of Fargo, City of Moorhead, City of Grand Forks, and City of East Grand Forks at the Red River at Fargo, North Dakota, from 2003 through 2012 and at Grand Forks, N.Dak., from 2007 through 2012. The purpose of the monitoring was to provide a better understanding of the water-quality dynamics of the Red River and provide a way to track changes in water quality. Regression equations were developed that can be used to estimate concentrations and loads for dissolved solids, sulfate, chloride, nitrate plus nitrite, total phosphorus, and suspended sediment using explanatory variables such as streamflow, specific conductance, and turbidity. Specific conductance was determined to be a significant explanatory variable for estimating dissolved solids concentrations at the Red River at Fargo and Grand Forks. The regression equations provided good relations between dissolved solid concentrations and specific conductance for the Red River at Fargo and at Grand Forks, with adjusted coefficients of determination of 0.99 and 0.98, respectively. Specific conductance, log-transformed streamflow, and a seasonal component were statistically significant explanatory variables for estimating sulfate in the Red River at Fargo and Grand Forks. Regression equations provided good relations between sulfate concentrations and the explanatory variables, with adjusted coefficients of determination of 0.94 and 0.89, respectively. For the Red River at Fargo and Grand Forks, specific conductance, streamflow, and a seasonal component were statistically significant explanatory variables for estimating chloride. For the Red River at Grand Forks, a time component also was a statistically significant explanatory variable for estimating chloride. The regression equations for chloride at the Red River at Fargo provided a fair relation between chloride concentrations and the explanatory variables, with an adjusted coefficient of determination of 0.66 and the equation for the Red River at Grand Forks provided a relatively good relation between chloride concentrations and the explanatory variables, with an adjusted coefficient of determination of 0.77. Turbidity and streamflow were statistically significant explanatory variables for estimating nitrate plus nitrite concentrations at the Red River at Fargo and turbidity was the only statistically significant explanatory variable for estimating nitrate plus nitrite concentrations at Grand Forks. The regression equation for the Red River at Fargo provided a relatively poor relation between nitrate plus nitrite concentrations, turbidity, and streamflow, with an adjusted coefficient of determination of 0.46. The regression equation for the Red River at Grand Forks provided a fair relation between nitrate plus nitrite concentrations and turbidity, with an adjusted coefficient of determination of 0.73. Some of the variability that was not explained by the equations might be attributed to different sources contributing nitrates to the stream at different times. Turbidity, streamflow, and a seasonal component were statistically significant explanatory variables for estimating total phosphorus at the Red River at Fargo and Grand Forks. The regression equation for the Red River at Fargo provided a relatively fair relation between total phosphorus concentrations, turbidity, streamflow, and season, with an adjusted coefficient of determination of 0.74. The regression equation for the Red River at Grand Forks provided a good relation between total phosphorus concentrations, turbidity, streamflow, and season, with an adjusted coefficient of determination of 0.87. For the Red River at Fargo, turbidity and streamflow were statistically significant explanatory variables for estimating suspended-sediment concentrations. For the Red River at Grand Forks, turbidity was the only statistically significant explanatory variable for estimating suspended-sediment concentration. The regression equation at the Red River at Fargo provided a good relation between suspended-sediment concentration, turbidity, and streamflow, with an adjusted coefficient of determination of 0.95. The regression equation for the Red River at Grand Forks provided a good relation between suspended-sediment concentration and turbidity, with an adjusted coefficient of determination of 0.96.

Geochemical map of the North Fork John Day River Roadless Area, Grant County, Oregon

USGS Publications Warehouse

Evans, James G.

1986-01-01

The North Fork John Day River Roadless Area comprised 21,210 acres in the Umatilla and Wallowa-Whitman National Forests, Grant County, Oregon, about 30 miles northwest of Baker, Oregon. The irregularly shaped area extends for about 1 mile on both sides of a 25-mile segment of the North Fork John Day River from Big Creek on the west to North Fork John Day Campground on the east. Most of the roadless area is in the northern half of the Desolation Butte 15-minute quadrangle. The eastern end of the area is in parts of the Granite and Trout Meadows 7½-minute quadrangles.

BLM helicase facilitates telomere replication during leading strand synthesis of telomeres

PubMed Central

Kosiyatrakul, Settapong T.

2015-01-01

Based on its in vitro unwinding activity on G-quadruplex (G4) DNA, the Bloom syndrome–associated helicase BLM is proposed to participate in telomere replication by aiding fork progression through G-rich telomeric DNA. Single molecule analysis of replicated DNA (SMARD) was used to determine the contribution of BLM helicase to telomere replication. In BLM-deficient cells, replication forks initiating from origins within the telomere, which copy the G-rich strand by leading strand synthesis, moved slower through the telomere compared with the adjacent subtelomere. Fork progression through the telomere was further slowed in the presence of a G4 stabilizer. Using a G4-specific antibody, we found that deficiency of BLM, or another G4-unwinding helicase, the Werner syndrome-associated helicase WRN, resulted in increased G4 structures in cells. Importantly, deficiency of either helicase led to greater increases in G4 DNA detected in the telomere compared with G4 seen genome-wide. Collectively, our findings are consistent with BLM helicase facilitating telomere replication by resolving G4 structures formed during copying of the G-rich strand by leading strand synthesis. PMID:26195664

Cancer therapy and replication stress: forks on the road to perdition.

PubMed

Kotsantis, Panagiotis; Jones, Rebecca M; Higgs, Martin R; Petermann, Eva

2015-01-01

Deregulated DNA replication occurs in cancer where it contributes to genomic instability. This process is a target of cytotoxic therapies. Chemotherapies exploit high DNA replication in cancer cells by modifying the DNA template or by inhibiting vital enzymatic activities that lead to slowing or stalling replication fork progression. Stalled replication forks can be converted into toxic DNA double-strand breaks resulting in cell death, i.e., replication stress. While likely crucial for many cancer treatments, replication stress is poorly understood due to its complexity. While we still know relatively little about the role of replication stress in cancer therapy, technical advances in recent years have shed new light on the effect that cancer therapeutics have on replication forks and the molecular mechanisms that lead from obstructed fork progression to cell death. This chapter will give an overview of our current understanding of replication stress in the context of cancer therapy. © 2015 Elsevier Inc. All rights reserved.

Assembly of Slx4 signaling complexes behind DNA replication forks.

PubMed

Balint, Attila; Kim, TaeHyung; Gallo, David; Cussiol, Jose Renato; Bastos de Oliveira, Francisco M; Yimit, Askar; Ou, Jiongwen; Nakato, Ryuichiro; Gurevich, Alexey; Shirahige, Katsuhiko; Smolka, Marcus B; Zhang, Zhaolei; Brown, Grant W

2015-08-13

Obstructions to replication fork progression, referred to collectively as DNA replication stress, challenge genome stability. In Saccharomyces cerevisiae, cells lacking RTT107 or SLX4 show genome instability and sensitivity to DNA replication stress and are defective in the completion of DNA replication during recovery from replication stress. We demonstrate that Slx4 is recruited to chromatin behind stressed replication forks, in a region that is spatially distinct from that occupied by the replication machinery. Slx4 complex formation is nucleated by Mec1 phosphorylation of histone H2A, which is recognized by the constitutive Slx4 binding partner Rtt107. Slx4 is essential for recruiting the Mec1 activator Dpb11 behind stressed replication forks, and Slx4 complexes are important for full activity of Mec1. We propose that Slx4 complexes promote robust checkpoint signaling by Mec1 by stably recruiting Dpb11 within a discrete domain behind the replication fork, during DNA replication stress. © 2015 The Authors.

Using Caffeine as a Water Quality Indicator in the Ambient Monitoring Program for Third Fork Creek Watershed, Durham, North Carolina

PubMed Central

Spence, Porché L

2015-01-01

Caffeine has been suggested as a chemical indicator for domestic wastewater in freshwater systems, although it is not included in water quality monitoring programs. The Third Fork Creek watershed in Durham, NC, is highly urbanized, with a history of receiving untreated wastewater from leaking and overflowing sanitary sewers. The poor water quality originating in the Third Fork Creek watershed threatens its intended uses and jeopardizes drinking water, aquatic life, and recreational activities provided by Jordan Lake. Organic waste contaminants have been detected in both Third Fork Creek watershed and Jordan Lake; however, the sampling periods were temporary, resulting in a few samples collected during nonstorm periods. It is recommended that (1) the concentration of caffeine and other organic waste contaminants are determined during storm and nonstorm periods and (2) caffeine is monitored regularly with traditional water quality indicators to evaluate the health of Third Fork Creek watershed. PMID:26157335

Ecological condition of the East Fork of the Gila River and selected tributaries: Gila National Forest, New Mexico

Treesearch

Robert D. Ohmart

1996-01-01

Ecological condition of riparian habitats along the East Fork of the Gila River, Main Diamond Creek, lower South Diamond Creek, and Black Canyon Creek are all in very heavily degraded condition. Channel cross-sections show extensive entrenchment, high width-to-depth ratios, and numerous reaches where banks are sloughing into the stream, especially on the East Fork of...

Persistence of historical logging impacts on channel form in mainstem North Fork Caspar Creek

Treesearch

Michael B. Napolitano

1998-01-01

The old-growth redwood forest of North Fork Caspar Creek was clear-cut logged between 1860 and 1904. Transportation of logs involved construction of a splash dam in the headwaters of North Fork Caspar Creek. Water stored behind the dam was released during large storms to enable log drives. Before log drives could be conducted, the stream channel had to be prepared by...

Qualitative Assessment: Evaluating the Impacts of Climate ...

EPA Pesticide Factsheets

The South Fork Nooksack River (South Fork) is located in northwest Washington State and is home to nine species of Pacific salmon, including Nooksack early Chinook (aka, spring Chinook salmon), an iconic species for the Nooksack Indian Tribe. The quantity of salmon in the South Fork, especially spring Chinook salmon, has dramatically declined from historic levels, due primarily to habitat degradation from the legacy impacts of various land uses such as commercial forestry, agriculture, flood control, and transportation infrastructure. Segments of the South Fork and some of its tributaries exceed temperature criteria established for the protection of cold-water salmonid populations, and were listed on Washington State’s Clean Water Act (CWA) 303(d) list of impaired waterbodies. High water temperatures in the South Fork are detrimental to fish and other native species that depend on cool, clean, well-oxygenated water. Of the nine salmon species, three have been listed as threatened under the federal Endangered Species Act (ESA) and are of high priority to restoration efforts in the South Fork—spring Chinook salmon, summer steelhead trout, and bull trout. Growing evidence shows that climate change will exacerbate legacy impacts. This qualitative assessment is a comprehensive analysis of climate change impacts on freshwater habitat and Pacific salmon in the South Fork. It also evaluates the effectiveness of restoration tools that address Pacific salmon recovery.

The PriA Replication Restart Protein Blocks Replicase Access Prior to Helicase Assembly and Directs Template Specificity through Its ATPase Activity*

PubMed Central

Manhart, Carol M.; McHenry, Charles S.

2013-01-01

The PriA protein serves as an initiator for the restart of DNA replication on stalled replication forks and as a checkpoint protein that prevents the replicase from advancing in a strand displacement reaction on forks that do not contain a functional replicative helicase. We have developed a primosomal protein-dependent fluorescence resonance energy transfer (FRET) assay using a minimal fork substrate composed of synthetic oligonucleotides. We demonstrate that a self-loading reaction, which proceeds at high helicase concentrations, occurs by threading of a preassembled helicase over free 5′-ends, an event that can be blocked by attaching a steric block to the 5′-end or coating DNA with single-stranded DNA binding protein. The specificity of PriA for replication forks is regulated by its intrinsic ATPase. ATPase-defective PriA K230R shows a strong preference for substrates that contain no gap between the leading strand and the duplex portion of the fork, as demonstrated previously. Wild-type PriA prefers substrates with larger gaps, showing maximal activity on substrates on which PriA K230R is inactive. We demonstrate that PriA blocks replicase function on forks by blocking its binding. PMID:23264623

Movements of adult chinook salmon during spawning migration in a metals-contaminated system, Coeur d'Alene River, Idaho

USGS Publications Warehouse

Goldstein, J.N.; Woodward, D.F.; Farag, A.M.

1999-01-01

Spawning migration of adult male chinook salmon Oncorhynchus tshawytscha was monitored by radio telemetry to determine their response to the presence of metals contamination in the South Fork of the Coeur d'Alene River, Idaho. The North Fork of the Coeur d'Alene River is relatively free of metals contamination and was used as a control. In all, 45 chinook salmon were transported from their natal stream, Wolf Lodge Creek, tagged with radio transmitters, and released in the Coeur d'Alene River 2 km downstream of the confluence of the South Fork and the North Fork of the Coeur d'Alene River. Fixed telemetry receivers were used to monitor the upstream movement of the tagged chinook salmon through the confluence area for 3 weeks after release. During this period, general water quality and metals concentrations were monitored in the study area. Of the 23 chinook salmon observed to move upstream from the release site and through the confluence area, the majority (16 fish, 70%) moved up the North Fork, and only 7 fish (30%) moved up the South Fork, where greater metals concentrations were observed. Our results agree with laboratory findings and suggest that natural fish populations will avoid tributaries with high metals contamination.

Hydrology of Eagle Creek Basin and effects of groundwater pumping on streamflow, 1969-2009

USGS Publications Warehouse

Matherne, Anne Marie; Myers, Nathan C.; McCoy, Kurt J.

2010-01-01

Urban and resort development and drought conditions have placed increasing demands on the surface-water and groundwater resources of the Eagle Creek Basin, in southcentral New Mexico. The Village of Ruidoso, New Mexico, obtains 60-70 percent of its water from the Eagle Creek Basin. The village drilled four production wells on Forest Service land along North Fork Eagle Creek; three of the four wells were put into service in 1988 and remain in use. Local citizens have raised questions as to the effects of North Fork well pumping on flow in Eagle Creek. In response to these concerns, the U.S. Geological Survey, in cooperation with the Village of Ruidoso, conducted a hydrologic investigation from 2007 through 2009 of the potential effect of the North Fork well field on streamflow in North Fork Eagle Creek. Mean annual precipitation for the period of record (1942-2008) at the Ruidoso climate station is 22.21 inches per year with a range from 12.27 inches in 1970 to 34.81 inches in 1965. Base-flow analysis indicates that the 1970-80 mean annual discharge, direct runoff, and base flow were 2,260, 1,440, and 819 acre-ft/yr, respectively, and for 1989-2008 were 1,290, 871, and 417 acre-ft/yr, respectively. These results indicate that mean annual discharge, direct runoff, and base flow were less during the 1989-2008 period than during the 1970-80 period. Mean annual precipitation volume for the study area was estimated to be 12,200 acre-feet. Estimated annual evapotranspiration for the study area ranged from 8,730 to 8,890 acre-feet. Estimated annual basin yield for the study area was 3,390 acre-ft or about 28 percent of precipitation. On the basis of basin-yield computations, annual recharge was estimated to be 1,950 acre-ft, about 16 percent of precipitation. Using a chloride mass-balance method, groundwater recharge over the study area was estimated to average 490 acre-ft, about 4.0 percent of precipitation. Because the North Fork wells began pumping in 1988, 1969-80 represents the pre-groundwater-pumping period, and 1988-2009 represents the groundwater-pumping period. The 5-year moving average for precipitation at the Ruidoso climate station shows years of below-average precipitation during both time periods, but no days of zero flow were recorded for the 11-year period 1970-80 and no-flow days were recorded in 11 of 20 years for the 1988-2009 period. View report for unabridged abstract.

Emerging technologies in microguidance and control

NASA Technical Reports Server (NTRS)

Weinberg, Marc S.

1993-01-01

Employing recent advances in microfabrication, the Charles Stark Draper Laboratory has developed inertial guidance instruments of very small size and low cost. Microfabrication employs the batch processing techniques of solid state electronics, such as photolithography, diffusion, and etching, to carve mechanical parts. Within a few years, microfabricated gyroscopes should perform in the 10 to 100 deg/h range. Microfabricated accelerometers have demonstrated performance in the 50 to 500 microgravity range. These instruments will result in not only the redesign of conventional military products, but also new applications that could not exist without small, inexpensive sensors and computing. Draper's microfabricated accelerometers and gyroscopes will be described and test results summarized. Associated electronics and control issues will also be addressed. Gimballed, vibrating gyroscopes and force rebalance accelerometers constructed from bulk silicon, polysilicon surface-machined tuning fork gyroscopes, and quartz resonant accelerometers and gyroscopes are examined. Draper is pursuing several types of devices for the following reasons: to address wide ranges of performance, to realize construction in a flat pack, and to lessen the risks associated with emerging technologies.

A Novel QEPAS with Microresonator in the Open Environment

NASA Astrophysics Data System (ADS)

Lin, Cheng; Zhu, Yong; Wei, Wei; Wang, Ning; Bao, Weiyi

2013-09-01

An improved quartz-enhanced photoacoustic spectroscopy (QEPAS) sensing system for trace gas detection is proposed. The optical fiber Fabry-Perot (F-P) demodulation method is used to replace the conventional electrical one in the QEPAS system. The experimental QEPAS system, which has a microresonator consisting of two stainless steel tubes with a length of 2.3 mm and an inner diameter of 0.9 mm, is implemented to detect the absorption of water vapor in the open environment. The structure parameters of the quartz tuning fork (QTF) are optimized in order to make the sensing system work more stably and reliably. Demonstration experiments are carried out. The vibration signal of the QTF was picked up by the optical fiber F-P demodulator and the conventional electrical scheme at the same time. Normalized noise equivalent absorption coefficients of and are obtained, respectively. The experimental result demonstrates that the sensitivity of the improved QEPAS sensing system with an optical fiber F-P demodulator is about 5.9 times higher than that of the conventional QEPAS system.

Beat frequency quartz-enhanced photoacoustic spectroscopy for fast and calibration-free continuous trace-gas monitoring

PubMed Central

Wu, Hongpeng; Dong, Lei; Zheng, Huadan; Yu, Yajun; Ma, Weiguang; Zhang, Lei; Yin, Wangbao; Xiao, Liantuan; Jia, Suotang; Tittel, Frank K.

2017-01-01

Quartz-enhanced photoacoustic spectroscopy (QEPAS) is a sensitive gas detection technique which requires frequent calibration and has a long response time. Here we report beat frequency (BF) QEPAS that can be used for ultra-sensitive calibration-free trace-gas detection and fast spectral scan applications. The resonance frequency and Q-factor of the quartz tuning fork (QTF) as well as the trace-gas concentration can be obtained simultaneously by detecting the beat frequency signal generated when the transient response signal of the QTF is demodulated at its non-resonance frequency. Hence, BF-QEPAS avoids a calibration process and permits continuous monitoring of a targeted trace gas. Three semiconductor lasers were selected as the excitation source to verify the performance of the BF-QEPAS technique. The BF-QEPAS method is capable of measuring lower trace-gas concentration levels with shorter averaging times as compared to conventional PAS and QEPAS techniques and determines the electrical QTF parameters precisely. PMID:28561065

Initial Geomorphic Responses to Removal of Milltown Dam, Clark Fork River, Montana, USA

NASA Astrophysics Data System (ADS)

Wilcox, A. C.; Brinkerhoff, D.; Woelfle-Erskine, C.

2008-12-01

The removal of Milltown Dam on the Clark Fork River, Montana, USA, is creating a field-scale experiment on upstream and downstream responses to dam removal and on how gravel-bed rivers respond to sediment pulses. Milltown Dam was removed in 2008, reconnecting the Clark Fork River to its upstream basin in terms of sediment transport and fish passage. This dam removal is especially notable because (1) it is the largest dam removal to date in the United States in terms of the volume of reservoir sediment potentially available for downstream transport (over 3 million m3; 1.7 million m3 are being mechanically removed); and (2) the dam is the downstream end of the largest Superfund site in the United States, the Clark Fork Complex, and reservoir sediments are composed largely of contaminated mine tailings. Data collection on pre- and post-dam removal channel morphology, bed sediment characteristics, and sediment loads are being used to investigate spatial and temporal patterns of sediment transport and deposition associated with this dam removal. In the first several months following breaching of the dam, snowmelt runoff with a 3-year recurrence interval peak caused substantial erosion and downstream transport of metals-laden sediments from Milltown reservoir. Reservoir sediments in the Clark Fork arm of Milltown reservoir eroded at levels far exceeding modeling predictions as a result of both incision to the new base level created by dam removal and bank retreat of over 200 m in reaches upstream of a constructed bypass reach and remediation area. Copper and other metals in these eroded reservoir sediments provide a tracer for identifying whether sediment deposits observed downstream of the dam originated from Milltown reservoir or uncontaminated tributaries and indicate that Milltown sediments have reached over 200 km downstream. Downstream deposition has been greatest along channel margins and in side-channel areas, whereas the transport capacity of the active channel has limited channel changes there.

Occurrence and distribution of fecal indicator bacteria, and physical and chemical indicators of water quality in streams receiving discharge from Dallas/Fort Worth International Airport and vicinity, North-Central Texas, 2008

USGS Publications Warehouse

Harwell, Glenn R.; Mobley, Craig A.

2009-01-01

This report, done by the U.S. Geological Survey in cooperation with Dallas/Fort Worth International (DFW) Airport in 2008, describes the occurrence and distribution of fecal indicator bacteria (fecal coliform and Escherichia [E.] coli), and the physical and chemical indicators of water quality (relative to Texas Surface Water Quality Standards), in streams receiving discharge from DFW Airport and vicinity. At sampling sites in the lower West Fork Trinity River watershed during low-flow conditions, geometric mean E. coli counts for five of the eight West Fork Trinity River watershed sampling sites exceeded the Texas Commission on Environmental Quality E. coli criterion, thus not fully supporting contact recreation. Two of the five sites with geometric means that exceeded the contact recreation criterion are airport discharge sites, which here means that the major fraction of discharge at those sites is from DFW Airport. At sampling sites in the Elm Fork Trinity River watershed during low-flow conditions, geometric mean E. coli counts exceeded the geometric mean contact recreation criterion for seven (four airport, three non-airport) of 13 sampling sites. Under low-flow conditions in the lower West Fork Trinity River watershed, E. coli counts for airport discharge sites were significantly different from (lower than) E. coli counts for non-airport sites. Under low-flow conditions in the Elm Fork Trinity River watershed, there was no significant difference between E. coli counts for airport sites and non-airport sites. During stormflow conditions, fecal indicator bacteria counts at the most downstream (integrator) sites in each watershed were considerably higher than counts at those two sites during low-flow conditions. When stormflow sample counts are included with low-flow sample counts to compute a geometric mean for each site, classification changes from fully supporting to not fully supporting contact recreation on the basis of the geometric mean contact recreation criterion. All water temperature measurements at sampling sites in the lower West Fork Trinity River watershed were less than the maximum criterion for water temperature for the lower West Fork Trinity segment. Of the measurements at sampling sites in the Elm Fork Trinity River watershed, 95 percent were less than the maximum criterion for water temperature for the Elm Fork Trinity River segment. All dissolved oxygen concentrations were greater than the minimum criterion for stream segments classified as exceptional aquatic life use. Nearly all pH measurements were within the pH criterion range for the classified segments in both watersheds, except for those at one airport site. For sampling sites in the lower West Fork Trinity River watershed, all annual average dissolved solids concentrations were less than the maximum criterion for the lower West Fork Trinity segment. For sampling sites in the Elm Fork Trinity River, nine of the 13 sites (six airport, three non-airport) had annual averages that exceeded the maximum criterion for that segment. For ammonia, 23 samples from 12 different sites had concentrations that exceeded the screening level for ammonia. Of these 12 sites, only one non-airport site had more than the required number of exceedances to indicate a screening level concern. Stormflow total suspended solids concentrations were significantly higher than low-flow concentrations at the two integrator sites. For sampling sites in the lower West Fork Trinity River watershed, all annual average chloride concentrations were less than the maximum annual average chloride concentration criterion for that segment. For the 13 sampling sites in the Elm Fork Trinity River watershed, one non-airport site had an annual average concentration that exceeded the maximum annual average chloride concentration criterion for that segment.

Archaeological Investigations in the Halls-Fowlkes Region South Fork of the Forked Deer River, West Tennessee

DTIC Science & Technology

1985-01-01

Obion-Forked Deer River and Reelfoot -Indian Creek drainages (Smith 1979a), the Mud Creek drainage (Dye 1975), the Cypress Creek drainages (Peterson 1975...sites have been identified by the presence of Palmer, Cypress Creek, Lost Lake , Decatur, Kirk Stemmed, Big Sandy, Plevna, Haywood, Kirk Corner Notched...necessary to clarify this problem. Several different Mississippian phases, including the Walls, Boxtown, Ensley, Tiptonville and Reelfoot phases have

UNIDENTIFIED CATENARY SUSPENSION BRIDGE ON RIVETED METAL PIERS, SHOWING HOWE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

UNIDENTIFIED CATENARY SUSPENSION BRIDGE ON RIVETED METAL PIERS, SHOWING HOWE PIPE TRUSS RAILING AND TRUSSED DECK BEAMS TYPICAL TO BRIDGES BUILT BY FLINN-MOYER COMPANY. TRIPODAL PIPE TOWERS RESEMBLE CLEAR FORK OF THE BRAZOS SUSPENSION BRIDGE’S TOWERS PRIOR TO ENCASEMENT IN CONCRETE. NOTE COLLAPSED TRUSS IN RIVER. ELEVATION VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

Maps showing mines, quarries, prospects, and exposures in the Devils Fork Roadless Area, Scott County, Virginia

USGS Publications Warehouse

Behum, Paul T.

1984-01-01

The Devils Fork Roadless Area is located at the eastern edge of the Appalachian coal region and is within the Cumberland Mountain section of the Appalachian Plateau physiographic province. Most of the area is drained by Devil Fork and its tributaries. Clinch Rock Branch of Straight Creek, Roddy Branch of Valley Creek, and Stinking Creek, all tributary to the Clinch River, drain small fringe tracts. Altitudes range from about 1,550 ft on the lower part of Straight Fork to about 3,490 ft at Cox Place on Little Mountain. Vegetation varies from mixed hardwoods in the uplands to thickets of conifer, rhododendron, and laurel in moist protected areas, as in coves along drainage courses.

Replication Fork Protection Factors Controlling R-Loop Bypass and Suppression.

PubMed

Chang, Emily Yun-Chia; Stirling, Peter C

2017-01-14

Replication-transcription conflicts have been a well-studied source of genome instability for many years and have frequently been linked to defects in RNA processing. However, recent characterization of replication fork-associated proteins has revealed that defects in fork protection can directly or indirectly stabilize R-loop structures in the genome and promote transcription-replication conflicts that lead to genome instability. Defects in essential DNA replication-associated activities like topoisomerase, or the minichromosome maintenance (MCM) helicase complex, as well as fork-associated protection factors like the Fanconi anemia pathway, both appear to mitigate transcription-replication conflicts. Here, we will highlight recent advances that support the concept that normal and robust replisome function itself is a key component of mitigating R-loop coupled genome instability.

Mass loading of selected major and trace elements in Lake Fork Creek near Leadville, Colorado, September-October 2001

USGS Publications Warehouse

Walton-Day, Katherine; Flynn, Jennifer L.; Kimball, Briant A.; Runkel, Robert L.

2005-01-01

A mass-loading study of Lake Fork Creek of the Arkansas River between Sugarloaf Dam and the mouth was completed in September-October 2001 to help ascertain the following: (1) variation of pH and aqueous constituent concentrations (calcium, sulfate, alkalinity, aluminum, cadmium, copper, iron, manganese, lead, and zinc) and their relation to toxicity standards along the study reach; (2) location and magnitude of sources of metal loading to Lake Fork Creek; (3) amount and locations of metal attenuation; (4) the effect of streamside wetlands on metal transport from contributing mine tunnels; and (5) the effect of organic-rich inflow from the Leadville National Fish Hatchery on water quality in Lake Fork Creek. The study was done in cooperation with the Bureau of Land Management, U.S. Department of Agriculture Forest Service, and U.S. Fish and Wildlife Service. Constituent concentrations and pH showed variable patterns over the study reach. Hardness-based acute and chronic toxicity standards were exceeded for some inflows and some constituents. However, stream concentrations did not exceed standards except for zinc starting in the upper parts of the study reach and extending to just downstream from the inflow from the Leadville National Fish Hatchery. Dilution from that inflow lowered stream zinc concentrations to less than acute and chronic toxicity standards. The uppermost 800 meters of the study reach that contained inflow from the Bartlett, Dinero, and Nelson mine tunnels and the Dinero wetland was the greatest source of loading for manganese and zinc. A middle section of the study reach that extended approximately 2 kilometers upstream from the National Fish Hatchery inflow to just downstream from that inflow was the largest source of aluminum, copper, iron, and lead loading. The loading was partially from the National Fish Hatchery inflow but also from unknown sources upstream from that inflow, possibly ground water. The largest sources for calcium and sulfate load to the stream were the parts of the study reach containing inflow from the tribu-taries Halfmoon Creek (calcium) and Willow Creek (sulfate). The Arkansas River and its tributaries upstream from Lake Fork Creek were the source of most of the calcium (70 percent), sulfate (82 percent), manganese (77 percent), lead (78 percent), and zinc (95 percent) loads in the Arkansas River downstream from the Lake Fork confluence. In contrast, Lake Fork Creek was the major source of aluminum (68 percent), copper (65 percent), and iron (87 percent) loads to the Arkansas River downstream from the confluence. Attenuation was not important for calcium, sulfate, or iron. However, other metals loads were reduced up to 81 percent over the study reach (aluminum, 25 percent; copper, 20 percent; manganese, 81 percent; lead, 30 percent; zinc, 72 percent). Metal attenuation in the stream occurred primarily in three locations (1) the irrigation diversion ditch; (2) the beaver pond complex extending from upstream from the Colorado Gulch inflow to just downstream from that inflow; and (3) the stream reach that included the inflow from Willow Creek. The most likely attenuation mechanism is precipitation of metal oxides and hydroxides (primarily manganese), and sorption or coprecipitation of trace elements with the precipitating phase. A mass-balance calculation indicated that the wetland between the Dinero Tunnel and Lake Fork Creek removed iron, had little effect on zinc mass load, and was a source for, or was releasing, aluminum and manganese. In contrast, the wetland that occurred between the Siwatch Tunnel and Lake Fork Creek removed aluminum, iron, manganese, and zinc from the tunnel drainage before it entered the creek. Inflow from the National Fish Hatchery increased dissolved organic carbon concentrations in Lake Fork Creek and slightly changed the composition of the dissolved organic carbon. However, dissolved organic carbon loads increased in the stream reach downs

Population ecology of variegate darter (Etheostoma variatum) in Virginia

USGS Publications Warehouse

Argentina, Jane E.; Angermeier, Paul; Hallerman, Eric M.

2013-01-01

Variegate darters (Etheostoma variatum) were listed as endangered in Virginia in 1992. Reasons for listing included habitat degradation and concerns about current and future impacts of coal mining throughout their Virginia range. Prior to this research, little was known about variegate darter distribution, habitat use, or populations in Virginia. Two primary goals of this research were to gain knowledge about the current population ecology and the relationship between landscape-level factors (e.g., land cover changes, watershed size, isolation from other populations) on current and past variegate darter population sizes.We investigated distribution, habitat suitability, population genetics, and population size and structure of variegate darters in the upper Big Sandy River drainage, Buchanan, Dickenson, and Wise Co., Virginia. Our results indicate variegate darters are primarily found in the Levisa Fork, with highest densities and abundances between its confluence with Dismal Creek and the Virginia-Kentucky border. Sporadic occurrences in smaller tributaries to the Levisa and Tug forks indicate they exist more widely in low densities, especially near the confluence with the Tug and Levisa mainstems. Detection of variegate darters in smaller tributaries was inconsistent, with reach-level occupancy estimates varying among years. We detected young-of-year variegate darters every year we sampled, but age 1+ darters were indistinguishable from older darters based on standard length.Variegate darter population size and stability in Virginia were estimated via multiple methods, including site occupancy surveys, mark-recapture studies, and population genetic analysis. Using mark-recapture methods at five sites, we estimated overall population size in 2011 to be approximately 12,800 individuals in the 35-km reach between the Levisa Fork - Dismal Creek confluence and the Virginia-Kentucky border. Age structure seemed stable, with breeding adults and young-of-year collected annually during 2008-2011. Population genetic analysis indicated variegate darters in the Levisa Fork and its tributaries are part of a single genetic population. Historical and current genetic stability were seen in our analysis of the variegate darter population, with no genetic differentiation among riffles across the upper Levisa Fork watershed, indicating dispersal among these sites is enough to overcome random genetic drift. This population is genetically isolated from downstream populations by the dam at Fishtrap Lake, Pike Co., Kentucky, and is beginning to show genetic isolation from other nearby populations. As expected, the Virginia population is most closely related to those in the Russell Fork and Levisa Fork downstream of the dam.Regular monitoring of variegate darters in the Levisa Fork mainstem from the Dismal Creek confluence to the Virginia-Kentucky border would facilitate better understanding of normal fluctuations of population size and distribution, as well as assessments of population status. This reach encompasses the core of the variegate darter population in Virginia, and its persistence will determine long-term viability of this species. Given that little is known about long-term population trends, we suggest that annual site-occupancy and population size estimates be made at ten randomly selected riffles for at least ten years to understand normal levels of variability. Thereafter, these population parameters could be monitored bi-annually as a way to detect shrinking distribution or abundance, especially after any fish kill or other pollution event in the Levisa Fork. We further suggest that the sites upstream and downstream of the saline diffusor pipe be monitored to detect changes in the extent of the impact zone.Overall, the variegate darter population in Virginia appears stable, although primarily confined to the lower 35 km of the Levisa Fork. Nevertheless, variegate darters in Virginia remain susceptible to extirpation due to catastrophic events, both physical (chemical spill) and biological (disease outbreak or invasive species introduction).

40 CFR 131.34 - Kansas.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Contact Recreation Basin: Solomon Subbasin: Upper North Fork Solomon Ash Creek 10260011 24 Primary Contact... Recreation Subbasin: Lower North Fork Solomon Beaver Creek 10260012 10 Primary Contact Recreation...

40 CFR 131.34 - Kansas.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Contact Recreation Basin: Solomon Subbasin: Upper North Fork Solomon Ash Creek 10260011 24 Primary Contact... Recreation Subbasin: Lower North Fork Solomon Beaver Creek 10260012 10 Primary Contact Recreation...

40 CFR 131.34 - Kansas.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Contact Recreation Basin: Solomon Subbasin: Upper North Fork Solomon Ash Creek 10260011 24 Primary Contact... Recreation Subbasin: Lower North Fork Solomon Beaver Creek 10260012 10 Primary Contact Recreation...

40 CFR 131.34 - Kansas.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Contact Recreation Basin: Solomon Subbasin: Upper North Fork Solomon Ash Creek 10260011 24 Primary Contact... Recreation Subbasin: Lower North Fork Solomon Beaver Creek 10260012 10 Primary Contact Recreation...

40 CFR 131.34 - Kansas.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Contact Recreation Basin: Solomon Subbasin: Upper North Fork Solomon Ash Creek 10260011 24 Primary Contact... Recreation Subbasin: Lower North Fork Solomon Beaver Creek 10260012 10 Primary Contact Recreation Beaver...

Application of Acoustic and Optic Methods for Estimating Suspended-Solids Concentrations in the St. Lucie River Estuary, Florida

USGS Publications Warehouse

Patino, Eduardo; Byrne, Michael J.

2004-01-01

Acoustic and optic methods were applied to estimate suspended-solids concentrations in the St. Lucie River Estuary, southeastern Florida. Acoustic Doppler velocity meters were installed at the North Fork, Speedy Point, and Steele Point sites within the estuary. These sites provide varying flow, salinity, water-quality, and channel cross-sectional characteristics. The monitoring site at Steele Point was not used in the analyses because repeated instrument relocations (due to bridge construction) prevented a sufficient number of samples from being collected at the various locations. Acoustic and optic instruments were installed to collect water velocity, acoustic backscatter strength (ABS), and turbidity data that were used to assess the feasibility of estimating suspended-solids concentrations in the estuary. Other data collected at the monitoring sites include tidal stage, salinity, temperature, and periodic discharge measurements. Regression analyses were used to determine the relations of suspended-solids concentration to ABS and suspended-solids concentration to turbidity at the North Fork and Speedy Point sites. For samples used in regression analyses, measured suspended-solids concentrations at the North Fork and Speedy Point sites ranged from 3 to 37 milligrams per liter, and organic content ranged from 50 to 83 percent. Corresponding salinity for these samples ranged from 0.12 to 22.7 parts per thousand, and corresponding temperature ranged from 19.4 to 31.8 ?C. Relations determined using this technique are site specific and only describe suspended-solids concentrations at locations where data were collected. The suspended-solids concentration to ABS relation resulted in correlation coefficients of 0.78 and 0.63 at the North Fork and Speedy Point sites, respectively. The suspended-solids concentration to turbidity relation resulted in correlation coefficients of 0.73 and 0.89 at the North Fork and Speedy Point sites, respectively. The adequacy of the empirical equations seems to be limited by the number and distribution of suspended-solids samples collected throughout the expected concentration range at the North Fork and Speedy Point sites. Additionally, the ABS relations for both sites seem to overestimate at the low end and underestimate at the high end of the concentration range. Based on the sensitivity analysis, temperature had a greater effect than salinity on estimated suspended-solids concentrations. Temperature also appeared to affect ABS data, perhaps by changing the absorptive and reflective characteristics of the suspended material. Salinity and temperature had no observed effects on the turbidity relation at the North Fork and Speedy Point sites. Estimates of suspended-solids concentrations using ABS data were less 'erratic' than estimates using turbidity data. Combining ABS and turbidity data into one equation did not improve the accuracy of results, and therefore, was not considered.

Water-Quality, Bed-Sediment, and Biological Data (October 2005 through September 2006) and Statistical Summaries of Long-Term Data for Streams in the Clark Fork Basin, Montana

USGS Publications Warehouse

Dodge, Kent A.; Hornberger, Michelle I.; Dyke, Jessica

2007-01-01

Water, bed sediment, and biota were sampled in streams from Butte to below Milltown Reservoir as part of a long-term monitoring program in the upper Clark Fork basin; additional water-quality samples were collected in the Clark Fork basin from sites near Milltown Reservoir downstream to near the confluence of the Clark Fork and Flathead River as part of a supplemental sampling program. The sampling programs were conducted in cooperation with the U.S. Environmental Protection Agency to characterize aquatic resources in the Clark Fork basin of western Montana, with emphasis on trace elements associated with historic mining and smelting activities. Sampling sites were located on the Clark Fork and selected tributaries. Water-quality samples were collected periodically at 22 sites from October 2005 through September 2006. Bed-sediment and biological samples were collected once at 12 sites during August 2006. This report presents the analytical results and quality-assurance data for water-quality, bed-sediment, and biota samples collected at all long-term and supplemental monitoring sites from October 2005 through September 2006. Water-quality data include concentrations of selected major ions, trace ele-ments, and suspended sediment. Nutrients also were analyzed in the supplemental water-quality samples. Daily values of suspended-sed-iment concentration and suspended-sediment discharge were determined for four sites, and seasonal daily values of turbidity were determined for four sites. Bed-sediment data include trace-ele-ment concentrations in the fine-grained fraction. Bio-logical data include trace-element concentrations in whole-body tissue of aquatic benthic insects. Statistical summaries of long-term water-quality, bed-sediment, and biological data for sites in the upper Clark Fork basin are provided for the period of record since 1985.

Stream-Sediment Geochemistry in Mining-Impacted Drainages of the Yankee Fork of the Salmon River, Custer County, Idaho

USGS Publications Warehouse

Frost, Thomas P.; Box, Stephen E.

2009-01-01

This reconnaissance study was undertaken at the request of the USDA Forest Service, Region 4, to assess the geochemistry, in particular the mercury and selenium contents, of mining-impacted sediments in the Yankee Fork of the Salmon River in Custer County Idaho. The Yankee Fork has been the site of hard-rock and placer mining, primarily for gold and silver, starting in the 1880s. Major dredge placer mining from the 1930s to 1950s in the Yankee Fork disturbed about a 10-kilometer reach. Mercury was commonly used in early hard-rock mining and placer operations for amalgamation and recovery of gold. During the late 1970s, feasibility studies were done on cyanide-heap leach recovery of gold from low-grade ores of the Sunbeam and related deposits. In the mid-1990s a major open-pit bulk-vat leach operation was started at the Grouse Creek Mine. This operation shut down when gold values proved to be lower than expected. Mercury in stream sediments in the Yankee Fork ranges from below 0.02 ppm to 7 ppm, with the highest values associated with old mill locations and lode and placer mines. Selenium ranges from below the detection limit for this study of 0.2 ppm to 4 ppm in Yankee Fork sediment samples. The generally elevated selenium content in the sediment samples reflect the generally high selenium contents in the volcanic rocks that underlie the Yankee Fork and the presence of gold and silver selenides in some of the veins that were exploited in the early phases of mining.

Surface-water quality assessment of the North Fork Red River basin upstream from Lake Altus, Oklahoma, 2002

USGS Publications Warehouse

Smith, S. Jerrod; Schneider, M.L.; Masoner, J.R.; Blazs, R.L.

2003-01-01

Elevated salinity in the North Fork Red River is a major concern of the Bureau of Reclamation W. C. Austin Project at Lake Altus. Understanding the relation between surface-water runoff, ground-water discharge, and surface-water quality is important for maintaining the beneficial use of water in the North Fork Red River basin. Agricultural practices, petroleum production, and natural dissolution of salt-bearing bedrock have the potential to influence the quality of nearby surface water. The U.S. Geological Survey, in cooperation with the Bureau of Reclamation, sampled stream discharge and water chemistry at 19 stations on the North Fork Red River and tributaries. To characterize surface-water resources of the basin in a systematic manner, samples were collected synoptically during receding streamflow conditions during July 8-11, 2002. Together, sulfate and chloride usually constitute greater than half of the dissolved solids. Concentrations of sulfate ranged from 87.1 to 3,450 milligrams per liter. The minimum value was measured at McClellan Creek near Back (07301220), and the maximum value was measured at Bronco Creek near Twitty (07301303). Concentrations of chloride ranged from 33.2 to 786 milligrams per liter. The minimum value was measured at a North Fork Red River tributary (unnamed) near Twitty (07301310), and the maximum value was measured at the North Fork Red River near Back (07301190), the most upstream sample station.

Human ribonuclease H1 resolves R-loops and thereby enables progression of the DNA replication fork.

PubMed

Parajuli, Shankar; Teasley, Daniel C; Murali, Bhavna; Jackson, Jessica; Vindigni, Alessandro; Stewart, Sheila A

2017-09-15

Faithful DNA replication is essential for genome stability. To ensure accurate replication, numerous complex and redundant replication and repair mechanisms function in tandem with the core replication proteins to ensure DNA replication continues even when replication challenges are present that could impede progression of the replication fork. A unique topological challenge to the replication machinery is posed by RNA-DNA hybrids, commonly referred to as R-loops. Although R-loops play important roles in gene expression and recombination at immunoglobulin sites, their persistence is thought to interfere with DNA replication by slowing or impeding replication fork progression. Therefore, it is of interest to identify DNA-associated enzymes that help resolve replication-impeding R-loops. Here, using DNA fiber analysis, we demonstrate that human ribonuclease H1 (RNH1) plays an important role in replication fork movement in the mammalian nucleus by resolving R-loops. We found that RNH1 depletion results in accumulation of RNA-DNA hybrids, slowing of replication forks, and increased DNA damage. Our data uncovered a role for RNH1 in global DNA replication in the mammalian nucleus. Because accumulation of RNA-DNA hybrids is linked to various human cancers and neurodegenerative disorders, our study raises the possibility that replication fork progression might be impeded, adding to increased genomic instability and contributing to disease. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Recombinase and translesion DNA polymerase decrease the speed of replication fork progression during the DNA damage response in Escherichia coli cells

PubMed Central

Tan, Kang Wei; Pham, Tuan Minh; Furukohri, Asako; Maki, Hisaji; Akiyama, Masahiro Tatsumi

2015-01-01

The SOS response is a DNA damage response pathway that serves as a general safeguard of genome integrity in bacteria. Extensive studies of the SOS response in Escherichia coli have contributed to establishing the key concepts of cellular responses to DNA damage. However, how the SOS response impacts on the dynamics of DNA replication fork movement remains unknown. We found that inducing the SOS response decreases the mean speed of individual replication forks by 30–50% in E. coli cells, leading to a 20–30% reduction in overall DNA synthesis. dinB and recA belong to a group of genes that are upregulated during the SOS response, and encode the highly conserved proteins DinB (also known as DNA polymerase IV) and RecA, which, respectively, specializes in translesion DNA synthesis and functions as the central recombination protein. Both genes were independently responsible for the SOS-dependent slowdown of replication fork progression. Furthermore, fork speed was reduced when each gene was ectopically expressed in SOS-uninduced cells to the levels at which they are expressed in SOS-induced cells. These results clearly indicate that the increased expression of dinB and recA performs a novel role in restraining the progression of an unperturbed replication fork during the SOS response. PMID:25628359

BRCA2 and RAD51 promote double-strand break formation and cell death in response to gemcitabine.

PubMed

Jones, Rebecca M; Kotsantis, Panagiotis; Stewart, Grant S; Groth, Petra; Petermann, Eva

2014-10-01

Replication inhibitors cause replication fork stalling and double-strand breaks (DSB) that result from processing of stalled forks. During recovery from replication blocks, the homologous recombination (HR) factor RAD51 mediates fork restart and DSB repair. HR defects therefore sensitize cells to replication inhibitors, with clear implications for cancer therapy. Gemcitabine is a potent replication inhibitor used to treat cancers with mutations in HR genes such as BRCA2. Here, we investigate why, paradoxically, mutations in HR genes protect cells from killing by gemcitabine. Using DNA replication and DNA damage assays in mammalian cells, we show that even short gemcitabine treatments cause persistent replication inhibition. BRCA2 and RAD51 are recruited to chromatin early after removal of the drug, actively inhibit replication fork progression, and promote the formation of MUS81- and XPF-dependent DSBs that remain unrepaired. Our data suggest that HR intermediates formed at gemcitabine-stalled forks are converted into DSBs and thus contribute to gemcitabine-induced cell death, which could have implications for the treatment response of HR-deficient tumors. ©2014 American Association for Cancer Research.

BRCA2 and RAD51 promote double-strand break formation and cell death in response to Gemcitabine

PubMed Central

Jones, Rebecca M.; Kotsantis, Panagiotis; Stewart, Grant S.; Groth, Petra; Petermann, Eva

2014-01-01

Replication inhibitors cause replication fork stalling and double-strand breaks (DSBs) that result from processing of stalled forks. During recovery from replication blocks, the homologous recombination (HR) factor RAD51 mediates fork restart and DSB repair. HR defects therefore sensitise cells to replication inhibitors, with clear implications for cancer therapy. Gemcitabine is a potent replication inhibitor used to treat cancers with mutations in HR genes such as BRCA2. Here we investigate why, paradoxically, mutations in HR genes protect cells from killing by Gemcitabine. Using DNA replication and -damage assays in mammalian cells, we show that even short Gemcitabine treatments cause persistent replication inhibition. BRCA2 and RAD51 are recruited to chromatin early after removal of the drug, actively inhibit replication fork progression and promote the formation of MUS81- and XPF-dependent DSBs that remain unrepaired. Our data suggest that HR intermediates formed at Gemcitabine-stalled forks are converted into DSBs and thus contribute to Gemcitabine-induced cell death, which could have implications for the treatment response of HR-deficient tumours. PMID:25053826

Mammalian RAD52 Functions in Break-Induced Replication Repair of Collapsed DNA Replication Forks.

PubMed

Sotiriou, Sotirios K; Kamileri, Irene; Lugli, Natalia; Evangelou, Konstantinos; Da-Ré, Caterina; Huber, Florian; Padayachy, Laura; Tardy, Sebastien; Nicati, Noemie L; Barriot, Samia; Ochs, Fena; Lukas, Claudia; Lukas, Jiri; Gorgoulis, Vassilis G; Scapozza, Leonardo; Halazonetis, Thanos D

2016-12-15

Human cancers are characterized by the presence of oncogene-induced DNA replication stress (DRS), making them dependent on repair pathways such as break-induced replication (BIR) for damaged DNA replication forks. To better understand BIR, we performed a targeted siRNA screen for genes whose depletion inhibited G1 to S phase progression when oncogenic cyclin E was overexpressed. RAD52, a gene dispensable for normal development in mice, was among the top hits. In cells in which fork collapse was induced by oncogenes or chemicals, the Rad52 protein localized to DRS foci. Depletion of Rad52 by siRNA or knockout of the gene by CRISPR/Cas9 compromised restart of collapsed forks and led to DNA damage in cells experiencing DRS. Furthermore, in cancer-prone, heterozygous APC mutant mice, homozygous deletion of the Rad52 gene suppressed tumor growth and prolonged lifespan. We therefore propose that mammalian RAD52 facilitates repair of collapsed DNA replication forks in cancer cells. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

DNA Replication Origins and Fork Progression at Mammalian Telomeres

PubMed Central

Higa, Mitsunori; Fujita, Masatoshi; Yoshida, Kazumasa

2017-01-01

Telomeres are essential chromosomal regions that prevent critical shortening of linear chromosomes and genomic instability in eukaryotic cells. The bulk of telomeric DNA is replicated by semi-conservative DNA replication in the same way as the rest of the genome. However, recent findings revealed that replication of telomeric repeats is a potential cause of chromosomal instability, because DNA replication through telomeres is challenged by the repetitive telomeric sequences and specific structures that hamper the replication fork. In this review, we summarize current understanding of the mechanisms by which telomeres are faithfully and safely replicated in mammalian cells. Various telomere-associated proteins ensure efficient telomere replication at different steps, such as licensing of replication origins, passage of replication forks, proper fork restart after replication stress, and dissolution of post-replicative structures. In particular, shelterin proteins have central roles in the control of telomere replication. Through physical interactions, accessory proteins are recruited to maintain telomere integrity during DNA replication. Dormant replication origins and/or homology-directed repair may rescue inappropriate fork stalling or collapse that can cause defects in telomere structure and functions. PMID:28350373

Distinct functions of human RecQ helicases during DNA replication.

PubMed

Urban, Vaclav; Dobrovolna, Jana; Janscak, Pavel

2017-06-01

DNA replication is the most vulnerable process of DNA metabolism in proliferating cells and therefore it is tightly controlled and coordinated with processes that maintain genomic stability. Human RecQ helicases are among the most important factors involved in the maintenance of replication fork integrity, especially under conditions of replication stress. RecQ helicases promote recovery of replication forks being stalled due to different replication roadblocks of either exogenous or endogenous source. They prevent generation of aberrant replication fork structures and replication fork collapse, and are involved in proper checkpoint signaling. The essential role of human RecQ helicases in the genome maintenance during DNA replication is underlined by association of defects in their function with cancer predisposition. Copyright © 2016 Elsevier B.V. All rights reserved.

75 FR 60740 - Record of Decision for the Base Closure and Realignment Beddown and Flight Operations of Remotely...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-01

... DEPARTMENT OF DEFENSE Department of the Air Force Record of Decision for the Base Closure and Realignment Beddown and Flight Operations of Remotely Piloted Aircraft at Grand Forks Air Force Base (AFB), ND... United States Air Force signed the ROD for the 2005 Base Closure and Realignment (BRAC 2005) directed...

Comparison of Three Biomass Sampling Techniques on Submersed Aquatic Plants in a Northern Tier Lake

DTIC Science & Technology

2010-07-01

distribution in 3 out of 14 species when comparing the box-core sampler and the rake method. These included forked duckweed (Lemna trisulca L, p...each site did not exhibit differences. These included coontail (p=0.2949), muskgrass (p=0.2746), American elodea (p=0.7622), forked duckweed (p...collected by the PVC-core sampler. These included coontail (p=0.000), chara (p=0.0219), American elodea (p=0.0061), forked duckweed (p=0.0000), najas (p

Grand Forks - East Grand Forks Urban Water Resources Study. East Grand Forks Flood Fight Manual.

DTIC Science & Technology

1981-07-01

wastewater management, and flood control) were identified, and a "plan of study" was developed. The plan of study outlined the general approach t~i -tiTd...three parts. Part 1 contains a general description and narrative on the need of the unit, Part 2 identifies the Unit Chief, Deputies, and Unit members...other units are discussed only in general terms. Future revisions will hopefully result in a happy medium between detailed specifics and generalities

An Inventory and Evaluation of Architectural and Engineering Resources of the Big South Fork National River and Recreation Area, Tennessee and Kentucky.

DTIC Science & Technology

1982-02-25

coordinated multidisciplinary study of both the architectural and engineering resources of the National Area. Both research b1 orientation and...South Fork just north of Rugby , and traveled through the site where Jamestown, Tennessee, now stands. A third trail, the Chickamauga Path, left the...Thomas Hughes (1881), the founder of the English colony of Rugby , Tennessee, described his neighbors in the Big South Fork area as mostly poor men

41 CFR 101-25.405 - Materials handling equipment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 50 45 40 30 25 20 15 10 Straddle truck 15 50 50 50 45 45 45 40 40 35 35 30 25 20 15 10 Electric Fork... percentage of acquisition costs (years in use) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Gasoline Fork truck (2000 pounds to 6000 pounds) 8 50 45 40 30 25 20 15 10 Fork truck (over 6000 pounds) 10 50 45 40 35 30 25 20 15...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakayama, T.; Kubo, O.; Shingaya, Y.

the research of advanced materials based on nanoscience and nanotechnology, it is often desirable to measure nanoscale local electrical conductivity at a designated position of a given sample. For this purpose, multiple-probe scanning probe microscopes (MP-SPMs), in which two, three or four scanning tunneling microscope (STM) or atomic force microscope (AFM) probes are operated independently, have been developed. Each probe in an MP-SPM is used not only for observing high-resolution STM or AFM images but also for forming an electrical contact enabling nanoscale local electrical conductivity measurement. The world's first double-probe STM (DP-STM) developed by the authors, which was subsequentlymore » modified to a triple-probe STM (TP-STM), has been used to measure the conductivities of one-dimensional metal nanowires and carbon nanotubes and also two-dimensional molecular films. A quadruple-probe STM (QP-STM) has also been developed and used to measure the conductivity of two-dimensional molecular films without the ambiguity of contact resistance between the probe and sample. Moreover, a quadruple-probe AFM (QP-AFM) with four conductive tuning-fork-type self-detection force sensing probes has been developed to measure the conductivity of a nanostructure on an insulating substrate. A general-purpose computer software to control four probes at the same time has also been developed and used in the operation of the QP-AFM. These developments and applications of MP-SPMs are reviewed in this paper.« less

Coma cluster of galaxies

NASA Technical Reports Server (NTRS)

1999-01-01

Atlas Image mosaic, covering 34' x 34' on the sky, of the Coma cluster, aka Abell 1656. This is a particularly rich cluster of individual galaxies (over 1000 members), most prominently the two giant ellipticals, NGC 4874 (right) and NGC 4889 (left). The remaining members are mostly smaller ellipticals, but spiral galaxies are also evident in the 2MASS image. The cluster is seen toward the constellation Coma Berenices, but is actually at a distance of about 100 Mpc (330 million light years, or a redshift of 0.023) from us. At this distance, the cluster is in what is known as the 'Hubble flow,' or the overall expansion of the Universe. As such, astronomers can measure the Hubble Constant, or the universal expansion rate, based on the distance to this cluster. Large, rich clusters, such as Coma, allow astronomers to measure the 'missing mass,' i.e., the matter in the cluster that we cannot see, since it gravitationally influences the motions of the member galaxies within the cluster. The near-infrared maps the overall luminous mass content of the member galaxies, since the light at these wavelengths is dominated by the more numerous older stellar populations. Galaxies, as seen by 2MASS, look fairly smooth and homogeneous, as can be seen from the Hubble 'tuning fork' diagram of near-infrared galaxy morphology. Image mosaic by S. Van Dyk (IPAC).

Structure of the replication fork in ultraviolet light-irradiated human cells.

PubMed Central

Cordeiro-Stone, M; Schumacher, R I; Meneghini, R

1979-01-01

The DNA extracted from xeroderma pigmentosum human fibroblasts previously irradiated with 12.5 J/m2 of UV light and pulse-labeled for 45 min with radioactive and (or) heavy precursors, was used to determine the structural characteristics of the replication fork. Density equilibrium centrifugation experiments showed that a fork moved 6 micrometer in 45 min and bypassed 3 pyrimidine dimers in both strands. The same length was covered in 15-20 min in control cells. The delay in irradiated cells was apparently due to pyrimidine dimers acting as temporary blocks to the fork movement. Evidence for this interpretation comes from kinetics of incorporation of [3H]thymidine into DNA, which show that the time necessary to attain a new stable level of DNA synthesis in irradiated cells is equivalent to that required for the replication fork to cover the interdimer distance in one strand. On the other hand, the action of S1 nuclease on DNA synthesized soon after irradiation gives rise to a bimodal distribution in neutral sucrose gradients, one peak corresponding to 43 X 10(6) daltons and the other to 3 X 10(6) daltons. These two DNA species are generated by the attack of the S1 nuclease on single-stranded regions associated with the replication fork. A possible explanation for these results is given by a model according to which there is a delayed bypass of the dimer in the leading strand and the appearance of gaps opposite pyrimidine dimers in the lagging strand, as a direct consequence of the discontinuous mode of DNA replication. In terms of the model, the DNA of 43 X 10(6) daltons corresponds to the leading strand, linked to the unreplicated branch of the forks, whereas the piece of 3 X 10(6) daltons is the intergap DNA coming from the lagging strand. Pulse and chase experiments reveal that the low molecular weight DNA grows in a pattern that suggests that more than one gap may be formed per replication fork. PMID:233582

Structure of the replication fork in ultraviolet light-irradiated human cells.

PubMed

Cordeiro-Stone, M; Schumacher, R I; Meneghini, R

1979-08-01

The DNA extracted from xeroderma pigmentosum human fibroblasts previously irradiated with 12.5 J/m2 of UV light and pulse-labeled for 45 min with radioactive and (or) heavy precursors, was used to determine the structural characteristics of the replication fork. Density equilibrium centrifugation experiments showed that a fork moved 6 micrometer in 45 min and bypassed 3 pyrimidine dimers in both strands. The same length was covered in 15-20 min in control cells. The delay in irradiated cells was apparently due to pyrimidine dimers acting as temporary blocks to the fork movement. Evidence for this interpretation comes from kinetics of incorporation of [3H]thymidine into DNA, which show that the time necessary to attain a new stable level of DNA synthesis in irradiated cells is equivalent to that required for the replication fork to cover the interdimer distance in one strand. On the other hand, the action of S1 nuclease on DNA synthesized soon after irradiation gives rise to a bimodal distribution in neutral sucrose gradients, one peak corresponding to 43 X 10(6) daltons and the other to 3 X 10(6) daltons. These two DNA species are generated by the attack of the S1 nuclease on single-stranded regions associated with the replication fork. A possible explanation for these results is given by a model according to which there is a delayed bypass of the dimer in the leading strand and the appearance of gaps opposite pyrimidine dimers in the lagging strand, as a direct consequence of the discontinuous mode of DNA replication. In terms of the model, the DNA of 43 X 10(6) daltons corresponds to the leading strand, linked to the unreplicated branch of the forks, whereas the piece of 3 X 10(6) daltons is the intergap DNA coming from the lagging strand. Pulse and chase experiments reveal that the low molecular weight DNA grows in a pattern that suggests that more than one gap may be formed per replication fork.

Lower Paleozoic deep-water facies of the Medfra area, central Alaska: A section in Geologic studies in Alaska by the U.S. Geological Survey, 1997

USGS Publications Warehouse

Dumoulin, Julie A.; Bradley, Dwight C.; Harris, Anita G.; Repetski, John E.

1999-01-01

Deep-water facies, chiefly hemipelagic deposits and turbidites, of Cambrian through Devonian age are widely exposed in the Medfra and Mt. McKinley quadrangles. These strata include the upper part of the Telsitna Formation (Middle-Upper Ordovician) and the Paradise Fork Formation (Lower Silurian-Lower Devonian) in the Nixon Fork terrane, the East Fork Hills Formation (Upper Cambrian-Lower Devonian) in the East Fork subterrane of the Minchumina terrane, and the chert and argillite unit (Ordovician) and the argillite and quartzite unit (Silurian- Devonian? and possibly older) in the Telida subterrane of the Minchumina terrane.In the western part of the study area (Medfra quadrangle), both hemipelagic deposits and turbidites are largely calcareous and were derived from the Nixon Fork carbonate platform. East- ern exposures (Mt. McKinley quadrangle; eastern part of the Telida subterrane) contain much less carbonate; hemipelagic strata are mostly chert, and turbidites contain abundant rounded quartz and lesser plagioclase and potassium feldspar. Deep-water facies in the Medfra quadrangle correlate well with rocks of the Dillinger terrane exposed to the south (McGrath quadrangle), but coeval strata in the Mt. McKinley quadrangle are compositionally similar to rocks to the northeast (Livengood quadrangle). Petrographic data thus suggest that the Telida subterranes presently defined is an artificial construct made up of two distinct sequences of disparate provenance.Restoration of 90 and 150 km of dextral strike-slip on the Iditarod and Farewell faults, respectively, aligns the deep-water strata of the Minchumina and Dillinger terranes in a position east of the Nixon Fork carbonate platform. This restoration supports the interpretation that lower Paleozoic rocks in the Nixon Fork and Dillinger terranes, and in the western part of the Minchumina terrane (East Fork subterrane and western part of the Telida subterrane), formed along a single continental margin. Rocks in the eastern part of the Telida subterrane are compositionally distinct from those to the west and may have had a different origin and history.

Recharge of shallow aquifers through two ephemeral-stream channels in northeastern Wyoming, 1982-1983

USGS Publications Warehouse

Lenfest, L.W.

1987-01-01

Quantifying the recharge from ephemeral streams to alluvial and bedrock aquifers will help evaluate the effects of surface mining on alluvial valley floors in Wyoming. Two stream reaches were chosen for study in the Powder River basin. One reach was located along the North Fork Dry Fork Cheyenne River near Glenrock, Wyoming, and the other reach was located along Black Thunder Creek near Hampshire, Wyoming. The reach along the North Fork Dry Fork Cheyenne River was instrumented with 3 gaging stations to measure streamflow and with 6 observation wells to measure groundwater level fluctuations in alluvial and bedrock aquifers in response to streamflow. The 3 streamflow gaging stations were located within the 2.5-mi study reach to measure the approximate gain or loss of discharge along the reach. Computed streamflow losses ranged from 0.43 acre-ft/mi on July 9 , 1982, to 1.44 acre-ft/mi on August 9, 1982. The observation wells completed only in the alluvial aquifer were dry during flow in the North Fork Dry Fork Cheyenne River, whereas water levels in half of the observation wells completed in the bedrock aquifers or the alluvial and bedrock aquifers rose in response to flow in the North Fork Dry Fork Cheyenne River. Groundwater recharge on August 9, 1982, was calculated using a convolution technique using groundwater levels at the upstream site and was estimated to be 26.5 acre-ft/mi. The reach along Black Thunder Creek was instrumented with one gaging station to measure streamflow and with 4 observation wells to measure water level response in alluvial and bedrock aquifers to streamflow. Recharge to the alluvial aquifer from flow in Black Thunder Creek ranged from 3.56 to 12.4 acre-ft/mi. The recharge was estimated using the convolution technique using water level measurements in the observation wells completed in the alluvial aquifer. Water level measurements in the observation wells indicated water level rises in the alluvial and bedrock aquifers in response to flow in Black Thunder Creek. (Author 's abstract)

Architecture and ssDNA interaction of the Timeless-Tipin-RPA complex

PubMed Central

Witosch, Justine; Wolf, Eva; Mizuno, Naoko

2014-01-01

The Timeless-Tipin (Tim-Tipin) complex, also referred to as the fork protection complex, is involved in coordination of DNA replication. Tim-Tipin is suggested to be recruited to replication forks via Replication Protein A (RPA) but details of the interaction are unknown. Here, using cryo-EM and biochemical methods, we characterized complex formation of Tim-Tipin, RPA and single-stranded DNA (ssDNA). Tim-Tipin and RPA form a 258 kDa complex with a 1:1:1 stoichiometry. The cryo-EM 3D reconstruction revealed a globular architecture of the Tim-Tipin-RPA complex with a ring-like and a U-shaped domain covered by a RPA lid. Interestingly, RPA in the complex adopts a horse shoe-like shape resembling its conformation in the presence of long ssDNA (>30 nucleotides). Furthermore, the recruitment of the Tim-Tipin-RPA complex to ssDNA is modulated by the RPA conformation and requires RPA to be in the more compact 30 nt ssDNA binding mode. The dynamic formation and disruption of the Tim-Tipin-RPA-ssDNA complex implicates the RPA-based recruitment of Tim-Tipin to the replication fork. PMID:25348395

14. INSIDE VIEW OF FLUME, LOOKING DOWNSTREAM TOWARD SETTLING BASIN, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. INSIDE VIEW OF FLUME, LOOKING DOWNSTREAM TOWARD SETTLING BASIN, SHOWING RIGHT FORK TO BYPASS, LEFT FORK TO BASIN - Electron Hydroelectric Project, Along Puyallup River, Electron, Pierce County, WA

Effects of Structural Flexibility on Motorcycle Straight Running Stability by using Energy Flow Method

NASA Astrophysics Data System (ADS)

Marumo, Yoshitaka; Katayama, Tsuyoshi

This study uses the energy flow method to analyze how structural flexibility affects the motorcycle wobble and weave modes. Lateral bending of the front fork and torsion of the main frame affect the wobble mode stability. These are based on the gyroscopic effect of the front wheel in the steering motion by considering structural flexibility. At high speeds, lateral bending of the front fork and torsion of the rear swing arm more significantly affect the weave mode stability. These are primarily due to the phase changes of the external force generated by the yaw rate in the lateral motion. The phase change of the yaw rate force in the lateral motion originates from the phase change of the tire side forces.

Concurrent Cuba

NASA Astrophysics Data System (ADS)

Hahn, T.

2016-10-01

The parallel version of the multidimensional numerical integration package Cuba is presented and achievable speed-ups discussed. The parallelization is based on the fork/wait POSIX functions, needs no extra software installed, imposes almost no constraints on the integrand function, and works largely automatically.

77 FR 41897 - Airworthiness Directives; PZL Swidnik S.A. Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-17

... control system hydraulic actuator fork end. These actions are intended to prevent rotation of the... locking of the longitudinal control system hydraulic actuator fork end. This condition, if not detected...

NEK8 regulates DNA damage-induced RAD51 foci formation and replication fork protection

PubMed Central

Abeyta, Antonio; Castella, Maria; Jacquemont, Celine; Taniguchi, Toshiyasu

2017-01-01

ABSTRACT Proteins essential for homologous recombination play a pivotal role in the repair of DNA double strand breaks, DNA inter-strand crosslinks and replication fork stability. Defects in homologous recombination also play a critical role in the development of cancer and the sensitivity of these cancers to chemotherapy. RAD51, an essential factor for homologous recombination and replication fork protection, accumulates and forms immunocytochemically detectable nuclear foci at sites of DNA damage. To identify kinases that may regulate RAD51 localization to sites of DNA damage, we performed a human kinome siRNA library screen, using DNA damage-induced RAD51 foci formation as readout. We found that NEK8, a NIMA family kinase member, is required for efficient DNA damage-induced RAD51 foci formation. Interestingly, knockout of Nek8 in murine embryonic fibroblasts led to cellular sensitivity to the replication inhibitor, hydroxyurea, and inhibition of the ATR kinase. Furthermore, NEK8 was required for proper replication fork protection following replication stall with hydroxyurea. Loading of RAD51 to chromatin was decreased in NEK8-depleted cells and Nek8-knockout cells. Single-molecule DNA fiber analyses revealed that nascent DNA tracts were degraded in the absence of NEK8 following treatment with hydroxyurea. Consistent with this, Nek8-knockout cells showed increased chromosome breaks following treatment with hydroxyurea. Thus, NEK8 plays a critical role in replication fork stability through its regulation of the DNA repair and replication fork protection protein RAD51. PMID:27892797

NEK8 regulates DNA damage-induced RAD51 foci formation and replication fork protection.

PubMed

Abeyta, Antonio; Castella, Maria; Jacquemont, Celine; Taniguchi, Toshiyasu

2017-02-16

Proteins essential for homologous recombination play a pivotal role in the repair of DNA double strand breaks, DNA inter-strand crosslinks and replication fork stability. Defects in homologous recombination also play a critical role in the development of cancer and the sensitivity of these cancers to chemotherapy. RAD51, an essential factor for homologous recombination and replication fork protection, accumulates and forms immunocytochemically detectable nuclear foci at sites of DNA damage. To identify kinases that may regulate RAD51 localization to sites of DNA damage, we performed a human kinome siRNA library screen, using DNA damage-induced RAD51 foci formation as readout. We found that NEK8, a NIMA family kinase member, is required for efficient DNA damage-induced RAD51 foci formation. Interestingly, knockout of Nek8 in murine embryonic fibroblasts led to cellular sensitivity to the replication inhibitor, hydroxyurea, and inhibition of the ATR kinase. Furthermore, NEK8 was required for proper replication fork protection following replication stall with hydroxyurea. Loading of RAD51 to chromatin was decreased in NEK8-depleted cells and Nek8-knockout cells. Single-molecule DNA fiber analyses revealed that nascent DNA tracts were degraded in the absence of NEK8 following treatment with hydroxyurea. Consistent with this, Nek8-knockout cells showed increased chromosome breaks following treatment with hydroxyurea. Thus, NEK8 plays a critical role in replication fork stability through its regulation of the DNA repair and replication fork protection protein RAD51.

Water-quality trends and constituent-transport analysis for selected sampling sites in the Milltown Reservoir/Clark Fork River Superfund Site in the upper Clark Fork Basin, Montana, water years 1996–2015

USGS Publications Warehouse

Sando, Steven K.; Vecchia, Aldo V.

2016-07-20

During the extended history of mining in the upper Clark Fork Basin in Montana, large amounts of waste materials enriched with metallic contaminants (cadmium, copper, lead, and zinc) and the metalloid trace element arsenic were generated from mining operations near Butte and milling and smelting operations near Anaconda. Extensive deposition of mining wastes in the Silver Bow Creek and Clark Fork channels and flood plains had substantial effects on water quality. Federal Superfund remediation activities in the upper Clark Fork Basin began in 1983 and have included substantial remediation near Butte and removal of the former Milltown Dam near Missoula. To aid in evaluating the effects of remediation activities on water quality, the U.S. Geological Survey began collecting streamflow and water-quality data in the upper Clark Fork Basin in the 1980s.Trend analysis was done on specific conductance, selected trace elements (arsenic, copper, and zinc), and suspended sediment for seven sampling sites in the Milltown Reservoir/Clark Fork River Superfund Site for water years 1996–2015. The most upstream site included in trend analysis is Silver Bow Creek at Warm Springs, Montana (sampling site 8), and the most downstream site is Clark Fork above Missoula, Montana (sampling site 22), which is just downstream from the former Milltown Dam. Water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends. Trend analysis was done by using a joint time-series model for concentration and streamflow. To provide temporal resolution of changes in water quality, trend analysis was conducted for four sequential 5-year periods: period 1 (water years 1996–2000), period 2 (water years 2001–5), period 3 (water years 2006–10), and period 4 (water years 2011–15). Because of the substantial effect of the intentional breach of Milltown Dam on March 28, 2008, period 3 was subdivided into period 3A (October 1, 2005–March 27, 2008) and period 3B (March 28, 2008–September 30, 2010) for the Clark Fork above Missoula (sampling site 22). Trend results were considered statistically significant when the statistical probability level was less than 0.01.In conjunction with the trend analysis, estimated normalized constituent loads (hereinafter referred to as “loads”) were calculated and presented within the framework of a constituent-transport analysis to assess the temporal trends in flow-adjusted concentrations (FACs) in the context of sources and transport. The transport analysis allows assessment of temporal changes in relative contributions from upstream source areas to loads transported past each reach outflow.Trend results indicate that FACs of unfiltered-recoverable copper decreased at the sampling sites from the start of period 1 through the end of period 4; the decreases ranged from large for one sampling site (Silver Bow Creek at Warm Springs [sampling site 8]) to moderate for two sampling sites (Clark Fork near Galen, Montana [sampling site 11] and Clark Fork above Missoula [sampling site 22]) to small for four sampling sites (Clark Fork at Deer Lodge, Montana [sampling site 14], Clark Fork at Goldcreek, Montana [sampling site 16], Clark Fork near Drummond, Montana [sampling site 18], and Clark Fork at Turah Bridge near Bonner, Montana [sampling site 20]). For period 4 (water years 2011–15), the most notable changes indicated for the Milltown Reservoir/Clark Fork River Superfund Site were statistically significant decreases in FACs and loads of unfiltered-recoverable copper for sampling sites 8 and 22. The period 4 changes in FACs of unfiltered-recoverable copper for all other sampling sites were not statistically significant.Trend results indicate that FACs of unfiltered-recoverable arsenic decreased at the sampling sites from period 1 through period 4 (water years 1996–2015); the decreases ranged from minor (sampling sites 8–20) to small (sampling site 22). For period 4 (water years 2011–15), the most notable changes indicated for the Milltown Reservoir/Clark Fork River Superfund Site were statistically significant decreases in FACs and loads of unfiltered-recoverable arsenic for sampling site 8 and near statistically significant decreases for sampling site 22. The period 4 changes in FACs of unfiltered-recoverable arsenic for all other sampling sites were not statistically significant.Trend results indicate that FACs of suspended sediment decreased at the sampling sites from period 1 through period 4 (water years 1996–2015); the decreases ranged from moderate (sampling site 8) to small (sampling sites 11–22). For period 4 (water years 2011–15), the changes in FACs of suspended sediment were not statistically significant for any sampling sites.The reach of the Clark Fork from Galen to Deer Lodge is a large source of metallic contaminants and suspended sediment, which strongly affects downstream transport of those constituents. Mobilization of copper and suspended sediment from flood-plain tailings and the streambed of the Clark Fork and its tributaries within the reach results in a contribution of those constituents that is proportionally much larger than the contribution of streamflow from within the reach. Within the reach from Galen to Deer Lodge, unfiltered-recoverable copper loads increased by a factor of about 4 and suspended-sediment loads increased by a factor of about 5, whereas streamflow increased by a factor of slightly less than 2. For period 4 (water years 2011–15), unfiltered-recoverable copper and suspended-sediment loads sourced from within the reach accounted for about 41 and 14 percent, respectively, of the loads at Clark Fork above Missoula (sampling site 22), whereas streamflow sourced from within the reach accounted for about 4 percent of the streamflow at sampling site 22. During water years 1996–2015, decreases in FACs and loads of unfiltered-recoverable copper and suspended sediment for the reach generally were proportionally smaller than for most other reaches.Unfiltered-recoverable copper loads sourced within the reaches of the Clark Fork between Deer Lodge and Turah Bridge near Bonner (just upstream from the former Milltown Dam) were proportionally smaller than contributions of streamflow sourced from within the reaches; these reaches contributed proportionally much less to copper loading in the Clark Fork than the reach between Galen and Deer Lodge. Although substantial decreases in FACs and loads of unfiltered-recoverable copper and suspended sediment were indicated for Silver Bow Creek at Warm Springs (sampling site 8), those substantial decreases were not translated to downstream reaches between Deer Lodge and Turah Bridge near Bonner. The effect of the reach of the Clark Fork from Galen to Deer Lodge as a large source of copper and suspended sediment, in combination with little temporal change in those constituents for the reach, contributes to this pattern.With the removal of the former Milltown Dam in 2008, substantial amounts of contaminated sediments that remained in the Clark Fork channel and flood plain in reach 9 (downstream from Turah Bridge near Bonner) became more available for mobilization and transport than before the dam removal. After the removal of the former Milltown Dam, the Clark Fork above Missoula (sampling site 22) had statistically significant decreases in FACs of unfiltered-recoverable copper in period 3B (March 28, 2008, through water year 2010) that continued in period 4 (water years 2011–15). Also, decreases in FACs of unfiltered-recoverable arsenic and suspended sediment were indicated for period 4 at this site. The decrease in FACs of unfiltered-recoverable copper for sampling site 22 during period 4 was proportionally much larger than the decrease for the Clark Fork at Turah Bridge near Bonner (sampling site 20). Net mobilization of unfiltered-recoverable copper and arsenic from sources within reach 9 are smaller for period 4 than for period 1 when the former Milltown Dam was in place, providing evidence that contaminant source materials have been substantially reduced in reach 9.

Von Economo Neurons and Fork Cells: A Neurochemical Signature Linked to Monoaminergic Function.

PubMed

Dijkstra, Anke A; Lin, Li-Chun; Nana, Alissa L; Gaus, Stephanie E; Seeley, William W

2018-01-01

The human anterior cingulate and frontoinsular cortices are distinguished by 2 unique Layer 5 neuronal morphotypes, the von Economo neurons (VENs) and fork cells, whose biological identity remains mysterious. Insights could impact research on diverse neuropsychiatric diseases to which these cells have been linked. Here, we leveraged the Allen Brain Atlas to evaluate mRNA expression of 176 neurotransmitter-related genes and identified vesicular monoamine transporter 2 (VMAT2), gamma-aminobutyric acid (GABA) receptor subunit θ (GABRQ), and adrenoreceptor α-1A (ADRA1A) expression in human VENs, fork cells, and a minority of neighboring Layer 5 neurons. We confirmed these results using immunohistochemistry or in situ hybridization. VMAT2 and GABRQ expression was absent in mouse cerebral cortex. Although VMAT2 is known to package monoamines into synaptic vesicles, in VENs and fork cells its expression occurs in the absence of monoamine-synthesizing enzymes or reuptake transporters. Thus, VENs and fork cells may possess a novel, uncharacterized mode of cortical monoaminergic function that distinguishes them from most other mammalian Layer 5 neurons. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of acid mine drainage on the stream ecosystem of the east fork of the Obey River, Tennessee

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nichols, L.E.; Bulow, F.L.

1973-01-01

The stream ecosystem of the east fork of the Obey River, Tennessee was studied from January through December 1970. Emphasis centered on water quality, macroinvertebrates, fish and aquatic flora affected by acid mine drainage. Two control stations were established within the study area, one located below the zone of pollution. A reservoir station was established to detect any neutralization occurring within Dale Hollow Reservoir below the confluence of the east fork and west fork. An area approximately 40 miles in length was found to be severely degraded by acid mine drainage. Limited macroinvertebrate populations existed within this region. Chironomus andmore » Sialis were the predominate benthic indicator organisms present in the polluted zone. Euglena mutabilis was the most abundant representative organism of the aquatic flora. This organism was found to be characteristic of acid mine pollution. Fish were recovered above and below, but not within, the zone of pollution. Fish recovered were characteristic of the type of habitat in which they were collected, being either typical stream or reservoir fish. A fish kill occurred in the east fork embayment of Dale Hollow on August 15, 1970 from acid mine drainage discharged upstream.« less

The annealing helicase and branch migration activities of Drosophila HARP.

PubMed

Kassavetis, George A; Kadonaga, James T

2014-01-01

HARP (SMARCAL1, MARCAL1) is an annealing helicase that functions in the repair and restart of damaged DNA replication forks through its DNA branch migration and replication fork regression activities. HARP is conserved among metazoans. HARP from invertebrates differs by the absence of one of the two HARP-specific domain repeats found in vertebrates. The annealing helicase and branch migration activity of invertebrate HARP has not been documented. We found that HARP from Drosophila melanogaster retains the annealing helicase activity of human HARP, the ability to disrupt D-loops and to branch migrate Holliday junctions, but fails to regress model DNA replication fork structures. A comparison of human and Drosophila HARP on additional substrates revealed that both HARPs are competent in branch migrating a bidirectional replication bubble composed of either DNA:DNA or RNA:DNA hybrid. Human, but not Drosophila, HARP is also capable of regressing a replication fork structure containing a highly stable poly rG:dC hybrid. Persistent RNA:DNA hybrids in vivo can lead to replication fork arrest and genome instability. The ability of HARP to strand transfer hybrids may signify a hybrid removal function for this enzyme, in vivo.

CANVAS FINISH TO REMOVE FLOAT MARKS. View is to the ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CANVAS FINISH TO REMOVE FLOAT MARKS. View is to the northwest of deck finishing operations - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

27 CFR 9.65 - North Fork of Roanoke.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Fork of Roanoke.” (b) Approved maps. The appropriate maps for determining the boundaries of the North... and 697 in Roanoke County. (2) Then the boundary follows State Route 697 northeast over Crawford Ridge...

27 CFR 9.65 - North Fork of Roanoke.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Fork of Roanoke.” (b) Approved maps. The appropriate maps for determining the boundaries of the North... and 697 in Roanoke County. (2) Then the boundary follows State Route 697 northeast over Crawford Ridge...

14. View to southwest. View through truss along centerline from ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. View to southwest. View through truss along centerline from below deck. (65mm lens) - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

20. View to southeast. Aerial view of bridge in setting; ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. View to southeast. Aerial view of bridge in setting; downstream side. (135mm lens) - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

COUNTERWEIGHT FOOTINGS ON EAST SIDE. View is to the north ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

COUNTERWEIGHT FOOTINGS ON EAST SIDE. View is to the north from the old suspension bridge - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

13. View to northeast. View along centerline from Humboldt County ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. View to northeast. View along centerline from Humboldt County side of bridge. (90mm lens) - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

JIGGER STICK USED IN ERECTION. Shown on highline, direction of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

JIGGER STICK USED IN ERECTION. Shown on highline, direction of view is probably to the north - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

12. View to southwest. View along centerline from Trinity County ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. View to southwest. View along centerline from Trinity County side of bridge. (90mm lens) - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

11. View to southeast. More distant overview of bridge in ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

11. View to southeast. More distant overview of bridge in setting; downstream side. (135mm lens) - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

26. MOORSE DRILL CABINET AND FORK ART FABRICATED AT SHOP ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

26. MOORSE DRILL CABINET AND FORK ART FABRICATED AT SHOP (L TO R)- LOOKING SOUTHEAST. - W. A. Young & Sons Foundry & Machine Shop, On Water Street along Monongahela River, Rices Landing, Greene County, PA

Concentrations and loads of cadmium, lead, and zinc measured near the peak of the 1999 snowmelt-runoff hydrographs for 42 water-quality stations, Coeur d'Alene River basin, Idaho

USGS Publications Warehouse

Woods, Paul F.

2000-01-01

The Coeur d’Alene River near Harrison transported 924 pounds of dissolved lead per day, of which 82.8 pounds came from the South Fork and 11.7 pounds from the North Fork. Only 10.2 percent of the load at Harrison was measured at the Pinehurst and Enaville stations; therefore, a substantial load of dissolved lead is being contributed downstream from the confluence of the North and South Forks.

Cultural Resource Investigation of the Grand Forks/East Grand Forks Urban Study and the East Grand Forks Flood Control Project,

DTIC Science & Technology

1981-04-01

and will not be impacted. Remarks: Level II. Father William Sherman, Pastor of St. Michael’s Church can be reached at St. Michael’s Church, 520 North...Trygg, J. William 1967 Composite Map of the Uni- % [ted States Land Surveyors’ L Original Plats and Field Notes, Minnesota Series, Sheet 20, Ely...Investigators/Years: Surveyors’ Original Plats and Notes, ’ 1872 Report/Reference: Trygg, J. William * 1967 Composite Map of United States Surveyors

Cultural Resources Reconnaissance for Proposed Flood Control Measures at Cramerton, Gaston County, North Carolina.

DTIC Science & Technology

1982-01-28

by the South Fork of the 6 I. .. . ... . .. . . . Catawba Piver. The South Fork is a major upper tributary of the Santee drainage system. :t rises in...streams in the survey area are first order tributaries . Several of the smaller streams are not depicted an the 1:24,000 topographic sheet. The South Fork...of i-ost.oid O’. Cultura aate’rial density in the s=r2eJ and deflated sample area is 0.35 piecei1.0 szuare meter. Anite quartz ncdules w€ere eroded

Integrated Natural Resources Management Plan Grand Forks Air Force Base, North Dakota. 2004-2008

DTIC Science & Technology

2005-12-01

5-37 5.7 Integrated Pest Management...5-44 5.7.3 Animal Pest Control...mph MSL 2005 INRMP Update 319th Civil Engineer Squadron/Environmental Management Automated Civil Engineer System Project Management Air Combat

75 FR 69097 - Allocations and Common Application and Reporting Waivers Granted to and Alternative Requirements...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-10

... award under this Notice. HUD computes allocations based on data that are generally available and that... Grand Forks, North Dakota, provided a very affordable soft-second loan as an incentive to help induce...

Water-Quality, Bed-Sediment, and Biological Data (October 2006 through September 2007) and Statistical Summaries of Long-Term Data for Streams in the Clark Fork Basin, Montana

USGS Publications Warehouse

Dodge, Kent A.; Hornberger, Michelle I.; Dyke, Jessica

2008-01-01

Water, bed sediment, and biota were sampled in streams from Butte to below Milltown Reservoir as part of a long-term monitoring program in the upper Clark Fork basin; additional water-quality samples were collected in the Clark Fork basin from sites near Milltown Reservoir downstream to near the confluence of the Clark Fork and Flathead River as part of a supplemental sampling program. The sampling programs were conducted in cooperation with the U.S. Environmental Protection Agency to characterize aquatic resources in the Clark Fork basin of western Montana, with emphasis on trace elements associated with historic mining and smelting activities. Sampling sites were located on the Clark Fork and selected tributaries. Water-quality samples were collected periodically at 22 sites from October 2006 through September 2007. Bed-sediment and biological samples were collected once at 12 sites during August 2007. This report presents the analytical results and quality-assurance data for water-quality, bed-sediment, and biota samples collected at all long-term and supplemental monitoring sites from October 2006 through September 2007. Water-quality data include concentrations of selected major ions, trace elements, and suspended sediment. Turbidity was analyzed for samples collected at sites where seasonal daily values of turbidity were being determined. Nutrients also were analyzed in the supplemental water-quality samples. Daily values of suspended-sediment concentration and suspended-sediment discharge were determined for four sites, and seasonal daily values of turbidity were determined for five sites. Bed-sediment data include trace-element concentrations in the fine-grained fraction. Biological data include trace-element concentrations in whole-body tissue of aquatic benthic insects. Statistical summaries of long-term water-quality, bed-sediment, and biological data for sites in the upper Clark Fork basin are provided for the period of record since 1985.

37. BRIDGE 115, SMITH RIVER MIDDLE FORK OREGON STATE HIGHWAY ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

37. BRIDGE 1-15, SMITH RIVER MIDDLE FORK OREGON STATE HIGHWAY 199. JOSEPHINE COUNTY, OREGON. LOOKING SSW. - Redwood National & State Parks Roads, California coast from Crescent City to Trinidad, Crescent City, Del Norte County, CA

2. GENERAL VIEW OF BRIDGE FROM ROADBED WITH 4' RANGE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. GENERAL VIEW OF BRIDGE FROM ROADBED WITH 4' RANGE POLE NEAR NORTHWEST CORNER OF BRIDGE, LOOKING SOUTH - North Fork Bridge, Spans North Fork of White River at State Highway 5, Norfork, Baxter County, AR

PIER 2. View is to the northeast, looking from Pier ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PIER 2. View is to the northeast, looking from Pier 1 toward Pier 2 from beneath completed bridge - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

3. View to southwest. Oblique view of downstream side of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. View to southwest. Oblique view of downstream side of bridge and west pier. (135mm lens) - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

2. View to east. Oblique view of downstream side of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. View to east. Oblique view of downstream side of bridge and east pier. (135mm lens) - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

9. View to northeast. Oblique view of upstream side of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. View to northeast. Oblique view of upstream side of bridge from approximately deck level. (90mm lens) - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

PLACING TOP CHORD CENTER PANEL. View to the northwest from ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

PLACING TOP CHORD CENTER PANEL. View to the northwest from the old suspension bridge. Chord members in place - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

17. View to west. Detail, connection point L2 (see plans), ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

17. View to west. Detail, connection point L2 (see plans), from below deck. (135mm lens) - South Fork Trinity River Bridge, State Highway 299 spanning South Fork Trinity River, Salyer, Trinity County, CA

35. CHARGING DOOR OF CUPOLA FORM LOFT, WITH FORKS FOR ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

35. CHARGING DOOR OF CUPOLA FORM LOFT, WITH FORKS FOR FEEDING COKE, FOUNDRY BELOW-LOOKING NORTH. - W. A. Young & Sons Foundry & Machine Shop, On Water Street along Monongahela River, Rices Landing, Greene County, PA

6. VIEW FACING EAST ALONG NORTH FACE OF BRIDGE AT ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

6. VIEW FACING EAST ALONG NORTH FACE OF BRIDGE AT CONSTRUCTION DETAILS OF WOOD RAILINGS AND STONE ABUTMENTS. - South Fork Tuolumne River Bridge, Spanning South Fork Tuolumne River on Tioga Road, Mather, Tuolumne County, CA

17. DETAIL VIEW OF WHAT APPEARS TO BE STIRRING FORK ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

17. DETAIL VIEW OF WHAT APPEARS TO BE STIRRING FORK THAT MIXED COFFEE BEANS AS THEY WERE HUSKED - Hacienda Cafetalera Santa Clara, Coffee Mill, KM 19, PR Route 372, Hacienda La Juanita, Yauco Municipio, PR

Pressure effects on the dissipative behavior of nanocrystalline diamond microelectromechanical resonators

NASA Astrophysics Data System (ADS)

Santos, J. T.; Holz, T.; Fernandes, A. J. S.; Costa, F. M.; Chu, V.; Conde, J. P.

2015-02-01

Diamond-based microelectromechanical resonators have the potential of enhanced performance due to the chemical inertness of the diamond structural layer and its high Young’s modulus, high wear resistance, low thermal expansion coefficient, and very high thermal conductivity. In this work, the resonance frequency and quality factor of MEMS resonators based on nanocrystalline diamond films are characterized under different air pressures. The dynamic behavior of 50-300 μm long linear bridges and double ended tuning forks, with resonance frequencies between 0.5 and 15 MHz and quality factors as high as 50 000 are described as a function of measurement pressure from high vacuum(~10 mTorr) up to atmospheric conditions. The resonance frequencies and quality factors in vacuum show good agreement with the theoretical models including anchor and thermoelastic dissipation (TED). The Young’s moduli for nanocrystalline diamond films extrapolated from experimental data are between 840-920 GPa. The critical pressure values, at which the quality factor starts decreasing due to dissipation in air, are dependent on the resonator length. Longer structures, with quality factors limited by TED and lower resonance frequencies, have low critical pressures, of the order of 1-10 Torr and go from an intrinsic dissipation, to a molecular dissipation regime and finally to a region of viscous dissipation. Shorter resonators, with higher resonance frequencies and quality factors limited by anchor losses, have higher critical pressures, some higher than atmospheric pressure, and enter directly into the viscous dissipation regime from the intrinsic region.

Research on Bell-Shaped Vibratory Angular Rate Gyro's Character of Resonator

PubMed Central

Su, Zhong; Fu, Mengyin; Li, Qing; Liu, Ning; Liu, Hong

2013-01-01

Bell-shaped vibratory angular rate gyro (abbreviated as BVG) is a new type Coriolis vibratory gyro that was inspired by Chinese traditional clocks. The resonator fuses based on a variable thickness axisymmetric multicurved surface shell. Its characteristics can directly influence the performance of BVG. The BVG structure not only has capabilities of bearing high overload, high impact and, compared with the tuning fork, vibrating beam, shell and a comb structure, but also a higher frequency to overcome the influence of the disturbance of the exterior environment than the same sized hemispherical resonator gyroscope (HRG) and the traditional cylinder vibratory gyroscope. It can be widely applied in high dynamic low precision angular rate measurement occasions. The main work is as follows: the issue mainly analyzes the structure and basic principle, and investigates the bell-shaped resonator's mathematical model. The reasonable structural parameters are obtained from finite element analysis and an intelligent platform. Using the current solid vibration gyro theory analyzes the structural characteristics and principles of BVG. The bell-shaped resonator is simplified as a paraboloid of the revolution mechanical model, which has a fixed closed end and a free opened end. It obtains the natural frequency and vibration modes based on the theory of elasticity. The structural parameters are obtained from the orthogonal method by the research on the structural parameters of the resonator analysis. It obtains the modal analysis, stress analysis and impact analysis with the chosen parameters. Finally, using the turntable experiment verifies the gyro effect of the BVG. PMID:23575033