A rock- and paleomagnetic study of a Holocene lava flow in Central Mexico

Magnetic measurements of the Tres Cruces lava flow (ca. 8500 years BP, Central Mexico) show the presence of two remanence carriers, a Ti-rich titanomagnetite with a Curie temperature between 350 and 400 °C and a Ti-poor magnetite with a Curie temperature close to 580°C. Magnetic changes after heating indicate that the titanomagnetite exsolves into magnetite w and ilmenite when the sample is heated to 580 °C. Paleointensity estimates with the Thellier and Thellier method [Thellier, E., Thellier, O., 1959. Sur l'intensité du champ magnetique terrestre dans le passe historique et geologique. Ann. Geophysique., 15, 285-376] were only successful up to temperatures of 350 to 400 °C. This temperature corresponds with the Curie temperature of the titanomagnetite, which is probably pseudo-single or multi-domain. Therefore, the paleointensities should be interpreted with caution. The magnetic composition changes after 580 °C heating may explain the large w variations in previous paleointensity determinations for the Tres Cruces rocks [Gonzalez, S., Sherwood, G., Bohnel, H., Schnepp, E., 1997. Palaeosecular variation in Central Mexico over the last 30,000 years: the record from lavas. Geophys. J. Int., 130, 201-219] using the [Shaw method Shaw, J., 1974. A new method of determining the magnitude of the palaeomagnetic field: application to five historic lavas and five archaeological samples. Geophys. J. R. Astr. Soc., 39, 133-141]

Hubungan Kuat Geser Pada Tanah Dengan Hasil Percobaan Dynamic Cone Penetrometer Pada Ruas Jalan Wori-likupang Kabupaten Minahasa Utara

Dynamic Cone Penetrometer (DCP) test has been done in Indonesia on the geotechnical and transportation field, to evaluate the properties of flexible pavement or subgrade. Some research that have been done for example, are producing a correlation between CBR and DCP in some types of soil. The use of DCP, a relatively inexpensive, and can be done repeatedly, also have been developed for practical applications, such as generating approximate shear strength in the field (in situ). In this research at 5 points of examination on the road Wori-Likupang North Minahasa regency, the relationship between the shear strength on the field from the use of the DCP with the shear strength from triaxial testing equipment on laboratory is calculated. The result obtained is 4 points almost has the same value, so the use of a DCP for the determination of shear strength field can be used as a road construction planning data

Analisa Kelelahan Struktur Pada Sambungan Antar Tiang Pancang Akibat Beban Horisontal

Indonesia merupakan salah satu Negara yang memiliki banyak sumber daya alam terutama minyak bumi, hal ini menyebabkan berkembangnya bangunan offshore di Indonesia. Jenis bangunan offshore yang digunakan di Indonesia yaitu jenis jacket platform. Tugas akhir ini bertujuan untuk mendesain jacket, dengan data topside load 1567 ton, tinggi gelombang 4,9987 m, periode gelombang 7 second. Mendesain jacket menggunakan software sap 2000 dimana desainnya berdasarkan peraturan API RP 2A WSD tahun 2002. Untuk analisis fatigue mengunakan tabel peristiwa gelombang (25 tahun). Dimensi tiang pancang yang digunakan sebesar 1,2 m dengan Daya dukung vertikal tiang pancang sebesar 210,835 ton dan Daya dukung horizontal sebesar 253,1879 ton. Dari analisis fatigue di sambungan antar tiang pancang didapat umur bangunan 95,202 tahun sehingga desain jacket aman untuk umur rencana bangunan 40 tahun

Enhancing Inhibition-Induced Plasticity in Tinnitus – Spectral Energy Contrasts in Tailor-Made Notched Music Matter

Chronic tinnitus seems to be caused by reduced inhibition among frequency selective neurons in the auditory cortex. One possibility to reduce tinnitus perception is to induce inhibition onto over-activated neurons representing the tinnitus frequency via tailor-made notched music (TMNM). Since lateral inhibition is modifiable by spectral energy contrasts, the question arises if the effects of inhibition-induced plasticity can be enhanced by introducing increased spectral energy contrasts (ISEC) in TMNM. Eighteen participants suffering from chronic tonal tinnitus, pseudo randomly assigned to either a classical TMNM or an ISEC-TMNM group, listened to notched music for three hours on three consecutive days. The music was filtered for both groups by introducing a notch filter centered at the individual tinnitus frequency. For the ISEC-TMNM group a frequency bandwidth of 3/8 octaves on each side of the notch was amplified, additionally, by about 20 dB. Before and after each music exposure, participants rated their subjectively perceived tinnitus loudness on a visual analog scale. During the magnetoencephalographic recordings, participants were stimulated with either a reference tone of 500 Hz or a test tone with a carrier frequency representing the individual tinnitus pitch. Perceived tinnitus loudness was significantly reduced after TMNM exposure, though TMNM type did not influence the loudness ratings. Tinnitus related neural activity in the N1m time window and in the so called tinnitus network comprising temporal, parietal and frontal regions was reduced after TMNM exposure. The ISEC-TMNM group revealed even enhanced inhibition-induced plasticity in a temporal and a frontal cortical area. Overall, inhibition of tinnitus related neural activity could be strengthened in people affected with tinnitus by increasing spectral energy contrast in TMNM, confirming the concepts of inhibition-induced plasticity via TMNM and spectral energy contrasts

Urban Park Development and Pediatric Obesity Rates: A Quasi-Experiment Using Electronic Health Record Data

INTRODUCTION: Childhood obesity affects ~20% of children in the United States. Environmental influences, such as parks, are linked with increased physical activity (PA). OBJECTIVE: To examine whether changes in Body Mass Index (BMI) z-score were associated with construction of a new park. METHODS: A quasi-experimental design was used to determine whether living in proximity of a park was associated with a reduction in BMI z-score. Children were selected from health clinics within an 11 mile radius of the park. A repeated-measure ANOVA was employed for analysis of the relationship between exposure (new park) and BMI z-score. RESULTS: Participants were 1443 (median age 10.3 range (2-17.9 years), BMI: z-score 0.84 ± 1.09) African American (77.4%) adolescents. Change in BMI z-score was not statistically different for children living at different distances from the park after controlling for age, gender, race, ethnicity, or payer type (p = 0.4482). We did observe a small 0.03 increase in BMI z-score from pre- to post-park (p = 0.0007). There was a significant positive association between child's baseline age and BMI z-score (p < 0.001). CONCLUSIONS: This study found proximity to a park was not associated with reductions in BMI z-score. Additional efforts to understand the complex relationship between park proximity, access, and PA are warranted

Sampling in Coal Handling and Preparation Plants

Sampling is the art of withdrawing a small quantity of material from a large lot in such a manner that the smaller fraction represents proportionally the same spec-ific composition and quality as present in the original entire lot. This is a difficult task and unless due atte-ntion is given to the sampling system white designing a plant it is not possible to achieve satisfactory results in our day to day practice. Attempt has been made in the present article to setforth some practical aspects of sampling and sampling procedure. Readers should use their own discretion and judgement to modify these techniques to suit their particular requirements always keeping in mind that the procedure adopted remained reliable and accurate

A cadaveric model to evaluate the effect of unloading the medial quadriceps on patellar tracking and patellofemoral joint pressure and stability

Background Vastus Medialis Muscles (VMM) damage has been widely identified following patellar dislocation. Rehabilitation programmes have been suggested to strengthen the VMM and reduce clinical symptoms of pain and instability. This controlled laboratory study investigated the hypothesis that reduced Vastus Medialis Obliquus (VMO) and Vastus Medialis Longus (VML) muscle tension would alter patellar tracking, stability and PFJ contact pressures. Methods Nine fresh-frozen dissected cadaveric knees were mounted in a rig with the quadriceps and iliotibial band loaded to 205 N. An optical tracking system measured joint kinematics and pressure sensitive film between the patella and trochlea measured PFJ contact pressures. Measurements were repeated for three conditions: 1. With all quadriceps heads and iliotibial band (ITB) loaded; 2. as 1, but with the VMO muscle unloaded and 3. as 1, but with the VMO and VML unloaded. Measurements were also repeated for the three conditions with a 10 N lateral displacement force applied to the patella. Results Reduction of VMM tension resulted in significant increases in lateral patellar tilt (2.8°) and translation (4 mm), with elevated lateral and reduced medial joint contact pressures from 0.48 to 0.14 MPa, and reduced patellar stability (all p < 0.05). Conclusions These findings provide basic scientific rationale to support the role of quadriceps strengthening to resist patellar lateral maltracking and rebalance the articular contact pressure away from the lateral facet in patients with normal patellofemoral joint anatomy

Vms1 and ANKZF1 peptidyl-tRNA hydrolases release nascent chains from stalled ribosomes

Ribosomal surveillance pathways scan for ribosomes that are transiently paused or terminally stalled owing to structural elements in mRNAs or nascent chain sequences. Some stalls in budding yeast are sensed by the GTPase Hbs1, which loads Dom34, a catalytically inactive member of the archaeo-eukaryotic release factor 1 superfamily. Hbs1–Dom34 and the ATPase Rli1 dissociate stalled ribosomes into 40S and 60S subunits. However, the 60S subunits retain the peptidyl-tRNA nascent chains, which recruit the ribosome quality control complex that consists of Rqc1–Rqc2–Ltn1–Cdc48–Ufd1–Npl4. Nascent chains ubiquitylated by the E3 ubiquitin ligase Ltn1 are extracted from the 60S subunit by the ATPase Cdc48–Ufd1–Npl4 and presented to the 26S proteasome for degradation. Failure to degrade the nascent chains leads to protein aggregation and proteotoxic stress in yeast and neurodegeneration in mice. Despite intensive investigations on the ribosome quality control pathway, it is not known how the tRNA is hydrolysed from the ubiquitylated nascent chain before its degradation. Here we show that the Cdc48 adaptor Vms1 is a peptidyl-tRNA hydrolase. Similar to classical eukaryotic release factor 1, Vms1 activity is dependent on a conserved catalytic glutamine. Evolutionary analysis indicates that yeast Vms1 is the founding member of a clade of eukaryotic release factor 1 homologues that we designate the Vms1-like release factor 1 clade