The Flathead Catfish in Unchannelized and Channelized Missouri River, Nebraska

Flathead catfish, Pylodictus olivaris (Rafinesque), were studied in approximately 83.7 km of unchannelized and 67.6 km miles of channelized Missouri River. Growth rates were slower in the unchannelized section than they were in the channelized section. The oldest fish in the unchannelized section was 25 years old, while in the channelized study area the oldest was 10 years. In the pectoral spines of progressively older fish from both sections, enlargement of the lumen obliterated early annuli. Much of the annual increment of growth was accomplished during June, July and August. Males became sexually mature at 3 to 4 years of age and 350 to 425 mm, while females matured between 3 and 5 years and 350 to 500 mm with most mature females measuring at least 450 mm. Approximately 1,500 eggs per pound of body weight were produced. Three orders of insects (Ephemeroptera, Trichoptera and Diptera) dominated the food habits of young-of-the-year flathead catfish in both study areas; however, there were some generic differences. Yearlings and adults consumed primarily fish and crayfish, with crayfish being more intensively utilized in the unchannelized study area. Fish 200 mm and longer were marked in order to estimate movements and population sizes. Between the two study areas there was little difference in movement patterns. Based on fishermen\u27s reports, 25 percent of the recaptured fish were within 1.6 km from the point of tagging. Mean upstream and downstream distances moved were identical (40.2 km) but 57 percent of the fish were reported downstream of the point of release. Our recapturing of marked fish indicated less movement (86 percent were within 1.6 km) than did recapturing by fishermen because we did not attempt to collect marked fish outside of the two study areas. Marked fish avoided crossing the main channel. Population estimates for fish 200 mm and longer were 17 fish per linear km and 9 per linear km in unchannelized and channelized study areas respectively. Estimated standing crops were 130 grams per hectare in the unchannelized study area and 149 grams per hectare in the channelized study area

Pion, kaon, proton and anti-proton transverse momentum distributions from p+p and d+Au collisions at sNN=200\sqrt{s_{NN}} = 200 GeV

Identified mid-rapidity particle spectra of $\pi^{\pm}$, $K^{\pm}$, and $p(\bar{p})$ from 200 GeV p+p and d+Au collisions are reported. A time-of-flight detector based on multi-gap resistive plate chamber technology is used for particle identification. The particle-species dependence of the Cronin effect is observed to be significantly smaller than that at lower energies. The ratio of the nuclear modification factor ($R_{dAu}$) between protons $(p+\bar{p})$ and charged hadrons ($h$) in the transverse momentum range $1.2<{p_{T}}<3.0$ GeV/c is measured to be $1.19\pm0.05$(stat)$\pm0.03$(syst) in minimum-bias collisions and shows little centrality dependence. The yield ratio of $(p+\bar{p})/h$ in minimum-bias d+Au collisions is found to be a factor of 2 lower than that in Au+Au collisions, indicating that the Cronin effect alone is not enough to account for the relative baryon enhancement observed in heavy ion collisions at RHIC.Comment: 6 pages, 4 figures, 1 table. We extended the pion spectra from transverse momentum 1.8 GeV/c to 3. GeV/

Demonstration of the temporal matter-wave Talbot effect for trapped matter waves

We demonstrate the temporal Talbot effect for trapped matter waves using ultracold atoms in an optical lattice. We investigate the phase evolution of an array of essentially non-interacting matter waves and observe matter-wave collapse and revival in the form of a Talbot interference pattern. By using long expansion times, we image momentum space with sub-recoil resolution, allowing us to observe fractional Talbot fringes up to 10th order.Comment: 17 pages, 7 figure

Azimuthal anisotropy at RHIC: the first and fourth harmonics

We report the first observations of the first harmonic (directed flow, v_1), and the fourth harmonic (v_4), in the azimuthal distribution of particles with respect to the reaction plane in Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC). Both measurements were done taking advantage of the large elliptic flow (v_2) generated at RHIC. From the correlation of v_2 with v_1 it is determined that v_2 is positive, or {\it in-plane}. The integrated v_4 is about a factor of 10 smaller than v_2. For the sixth (v_6) and eighth (v_8) harmonics upper limits on the magnitudes are reported.Comment: 6 pages with 3 figures, as accepted for Phys. Rev. Letters The data tables are at http://www.star.bnl.gov/central/publications/pubDetail.php?id=3

Mid-rapidity anti-proton to proton ratio from Au+Au collisions at sNN=130 \sqrt{s_{NN}} = 130 GeV

We report results on the ratio of mid-rapidity anti-proton to proton yields in Au+Au collisions at \rts = 130 GeV per nucleon pair as measured by the STAR experiment at RHIC. Within the rapidity and transverse momentum range of $|y|<0.5$ and 0.4 $<p_t<$ 1.0 GeV/$c$, the ratio is essentially independent of either transverse momentum or rapidity, with an average of $0.65\pm 0.01_{\rm (stat.)} \pm 0.07_{\rm (syst.)}$ for minimum bias collisions. Within errors, no strong centrality dependence is observed. The results indicate that at this RHIC energy, although the $p$-\pb pair production becomes important at mid-rapidity, a significant excess of baryons over anti-baryons is still present.Comment: 5 pages, 3 figures, accepted by Phys. Rev. Let

Transverse-momentum ptp_t correlations on (η,ϕ)(\eta,\phi) from mean-ptp_{t} fluctuations in Au-Au collisions at sNN=\sqrt{s_{NN}} = 200 GeV

We present first measurements of the pseudorapidity and azimuth $(\eta,\phi)$ bin-size dependence of event-wise mean transverse momentum $$ fluctuations for Au-Au collisions at $\sqrt{s_{NN}} = 200$ GeV. We invert that dependence to obtain $p_t$ autocorrelations on differences $(\eta_\Delta,\phi_\Delta)$ interpreted to represent velocity/temperature distributions on ($\eta,\phi$). The general form of the autocorrelations suggests that the basic correlation mechanism is parton fragmentation. The autocorrelations vary strongly with collision centrality, which suggests that fragmentation is strongly modified by a dissipative medium in the more central Au-Au collisions relative to peripheral or p-p collisions. \\Comment: 7 pages, 3 figure

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Effects of Main Stem Impoundments and Channelization upon the Limnology of the Missouri River, Nebraska

Rigid control has been imposed upon the Missouri River by impounding over one-half of the upper 1,500 miles and by channeling most of the remaining river within permanent, narrow banks. These controls have caused environmental changes in the lower Missouri River, as shown by this study, of adjacent unchannelized and channelized sections of river below the main stem impoundments. Impoundments have regulated flow by evening maximum and minimum discharges and improved downstream water quality by decreasing turbidity and indirectly raising the dissolved oxygen. In addition the impoundments have contributed a limnetic cladoceran, Leptodora kindti, to the drift and have affected the distribution of benthos through the modification of turbidity. Channelization of the river has reduced both the size and variety of aquatic habitat by destroying key productive areas. Average standing crops of benthos were similar in unchannelized and channelized river (0.63 and 0.67 pounds per acre, respectively) but the benthic area had been reduced 67% by channelization. In the channelized river the average standing crop of drift was 8 g per acre-foot while in the unaltered river the average standing crop was 68 g per acre-foot. There was little similarity between the organisms of the drift and benthos; however there was similarity between the organisms in the drift and the aufwuchs