Mud Creek Urban Nonpoint Source Demonstration

Northwest Arkansas is the seventh fastest developing area in the nation. The conversion of rolling pastureland into paved city streets, parking lots, and buildings within this rapidly urbanizing region is reducing infiltration and intensifying stormwater runoff. In the city of Fayetteville alone, the population increased from 42,099 to 58,163 between 1990 and 1999, moving the city across the population threshold which will require the Phase II Stormwater Permit process. Approximately half of Fayetteville is included in the Illinois River Watershed, which has been identified as the third highest priority watershed in need of restoration in the state of Arkansas. Mud Creek, an urban tributary to the Illinois River, receives half of the treated effluent from the Fayetteville municipal wastewater treatment plant in addition to capturing residential and commercial runoff in Northeast Fayetteville. Pollutants including sediment, nutrients, bacteria and chemicals can be channeled off residential lawns, parking lots, and construction sites, through stormdrains, and into area water resources. For these reasons, the Mud Creek sub-basin of the Illinois River was the focus of an EPA 319(h) grant-funded project focusing on urban NPS prevention education. The Mud Creek Project was the first of it’s kind in Arkansas to target urban audiences, promoting their role and responsibility in improving and protecting the water quality in an urbanizing watershed

Sexual Offending, Language and Probation Practice

The label ‘sex(ual) offender’, is commonly used to describe those with a sexual offence conviction. Yet, this labelling does much to discourage the rehabilitative efforts of the individual with the conviction, and those supporting their rehabilitation and reintegration journey. Increasingly, there is acknowledgement in academia, policy and practice that language matters. Within probation, for example, there has been a move to using more inclusive terminology such as ‘person on probation’ (PoP). This has replaced the often ‘offender’ laden policy documentation underpinning probation practice and is a seismic change in the right direction. However, parallel to this positive change, discourse surrounding individuals who have a conviction for a sexual crime remains, overall, unchanged. This differential approach contributes to ‘othering’ such individuals, and has stigmatising and ostracising qualities which can have detrimental long-term consequences and subsequently impede probation practice. This paper (i) makes the case for inclusive, and person-centred language for all, and (ii) addresses the implications of terminology usage for people working in probation

Survival of Fecal Contamination Indicator Organisms in Soil

Soils amended with human or animal waste may result in pathogen contamination of ground and surface water. Because temperature has been shown to affect pathogen survival, two laboratory studies were conducted to evaluate the impact of extremes in temperature on bacterial and viral pathogen indicator die-off in soil. A Captina silt loam was amended with broiler litter (0.1 g/g dry soil), septic tank effluent, or Escherichia coli (ATCC 13706) culture (both at 0.04 and 0.1 mL/g dry soil in the two respective studies), incubated at 5 and 35°C, and analyzed over time to determine the number of fecal coliform, E. coli, and coliphage remaining. Pathogen indicator die-off rate constants (k) for all indicator- temperature-treatment combinations were determined by first-order kinetics. For all three pathogen indicators, die-off was significantly more rapid at 35°C than at 5°C. In both studies, fecal coliform die-off rates were not different from E. coli die-off rates across each temperature-treatment combination. Levels of these bacterial indicators appeared in a ratio of 1:0.94 with 95% confidence intervals at 0.89 and 0.99 in the E. coli- and litter-amended soils. Die-off of the viral indicator was significantly slower than the die-off of the bacterial indicators at 5°C in litter-amended soil. Die-off of the bacterial indicator, E. coli, in soil amended with E. coli culture was not significantly different than die-off in soil amended with broiler litter at 5 or 35°C in the two studies. Because the higher incubation temperature increased die-off rates for all three indicators, it is expected that the potential for contamination of ground and surface water decreases with increasing temperature

Movements of White-Headed and White-Backed Vultures

Vultures are the only obligate vertebrate scavengers, and as such provide crucial services as keystone species and support the health and function of ecosystems in which they live. African vultures are a diverse group, with nine species found throughout Sub-Saharan Africa, many with overlapping distributions. Unfortunately, African vultures are faced with numerous threats throughout their range that have led to significant population declines, some greater than 90%, in only three generations. Four of these species are currently listed as critically endangered, and three as endangered. Despite the significant perils faced by African vultures, there are still significant knowledge gaps and, until recently, very little was known about vultures in Mozambique, a large country that falls within the distribution of six of these species. Our research in Gorongosa National Park, Mozambique, focused on movement data collected from 10 White-backed Vultures (Gyps africanus) and 12 White-headed Vultures (Trigonoceps occipitalis), one of Africa’s rarest vulture species. We first focused on estimating White-headed Vulture monthly home ranges and core ranges with continuous-time movement models. We assessed the relationship between ranging behavior and extrinsic (environmental characteristics) and intrinsic (individual characteristics) predictor variables using Bayesian generalized linear mixed effects models. We also explored the degree of White-headed Vulture home range and core range overlap with Gorongosa National Park and its buffer zone. We found that breeding individuals had smaller home ranges and could maintain these into the non-breeding season or abandon them. These small breeding and non-breeding home ranges were representative of central place foraging and averaged 239 km2 and 131 km2, respectively, 80-90% smaller than the average 1180 km2 non-breeding, non-central place foraging home range. Home ranges of birds that used resources outside of the park and its buffer zone were approximately 2.5 times larger than of birds that stayed within park boundaries, suggesting an increase in search effort required to locate less abundant resources. Excursions outside of the park and its buffer zone were rare. Only 15 of the 149 monthly home ranges suggested that birds used resources outside the park; the remaining 134 monthly home ranges fell within 10 km of the edge of the park buffer zone. Additionally, we explored differences in White-headed Vulture and White-backed Vulture movement characteristics. We used Bayesian generalized linear models to determine the effect of species as a predictor for flight altitude, flight speed, onset of movement on two scales (\u3e100 m and \u3e1000 m), and onset of flight at altitude, and the effect of species and hour predictors on hourly activity levels. We found that White-headed Vultures flew at lower altitudes and slower speeds, and initiated movement and flight at altitude earlier than White-backed Vultures. All of these findings correspond with flight less reliant on strong thermals and suggest that the White-headed Vulture is more likely a pioneer than follower. These findings expand on our understanding of both space use by White-headed Vultures and their place within the avian scavenging guild. They also demonstrate the critical importance of protected areas for the survival of the White-headed, and probably other, African Vultures

A study of inner zone electron data and their comparison with trapped radiation models

A summary and intercomparison of recent inner radiation zone electron data are presented. The morphology of the inner radiation zone is described and the data compared with the current generation of inner zone trapped electron models. An analytic representation of the inner zone equatorial pitch angle distribution is presented. This model was based upon data from eight satellites and was used to reduce all data to the form of equatorial flux. Although no Starfish-free high energy electron measurements were available from the inner portion of the inner radiation zone, it was found that the AE-6 model provided a good description of the present solar maximum environment

Observation of Fermi-energy dependent unitary impurity resonances in a strong topological insulator Bi_2Se_3 with scanning tunneling spectroscopy

Scanning tunneling spectroscopic studies of Bi_2Se_3 epitaxial films on Si (111) substrates reveal highly localized unitary impurity resonances associated with non-magnetic quantum impurities. The strength of the resonances depends on the energy difference between the Fermi level (E_F) and the Dirac point (E_D) and diverges as E_F approaches E_D. The Dirac-cone surface state of the host recovers within ~ 2Å spatial distance from impurities, suggesting robust topological protection of the surface state of topological insulators against high-density impurities that preserve time reversal symmetry

Measurement of a Sign-Changing Two-Gap Superconducting Phase in Electron-Doped Ba(Fe_{1-x}Co_x)_2As_2 Single Crystals using Scanning Tunneling Spectroscopy

Scanning tunneling spectroscopic studies of $Ba(Fe_{1-x}Co_x)_2As_2$ (x = 0.06, 0.12) single crystals reveal direct evidence for predominantly two-gap superconductivity. These gaps decrease with increasing temperature and vanish above the superconducting transition $T_c$. The two-gap nature and the slightly doping- and energy-dependent quasiparticle scattering interferences near the wave-vectors $(\pm \pi, 0)$ and $(0, \pm \pi)$ are consistent with sign-changing $s$-wave superconductivity. The excess zero-bias conductance and the large gap-to-$T_c$ ratios suggest dominant unitary impurity scattering.Comment: 4 pages, 4 figures. Paper accepted for publication in Physical Review Letters. Contact author: Nai-Chang Yeh ([email protected]

Scanning Tunnelling Spectroscopic Studies of Dirac Fermions in Graphene and Topological Insulators

We report novel properties derived from scanning tunnelling spectroscopic (STS) studies of Dirac fermions in graphene and the surface state (SS) of a strong topological insulator (STI), Bi_2Se_3. For mono-layer graphene grown on Cu by chemical vapour deposition (CVD), strain-induced scalar and gauge potentials are manifested by the charging effects and the tunnelling conductance peaks at quantized energies, respectively. Additionally, spontaneous time-reversal symmetry breaking is evidenced by the alternating anti-localization and localization spectra associated with the zero-mode of two sublattices while global time-reversal symmetry is preserved under the presence of pseudo-magnetic fields. For Bi_2Se_3 epitaxial films grown on Si(111) by molecular beam epitaxy (MBE), spatially localized unitary impurity resonances with sensitive dependence on the energy difference between the Fermi level and the Dirac point are observed for samples thicker than 6 quintuple layers (QL). These findings are characteristic of the SS of a STI and are direct manifestation of strong topological protection against impurities. For samples thinner than 6-QL, STS studies reveal the openup of an energy gap in the SS due to overlaps of wave functions between the surface and interface layers. Additionally, spin-preserving quasiparticle interference wave-vectors are observed, which are consistent with the Rashba-like spin-orbit splitting

AE 6: A model environment of trapped electrons for solar maximum

A projected inner zone electron model environment, AE 6, for the epoch 1980 is presented. It is intended to provide estimates of mission fluxes that spacecraft will encounter in the coming solar maximum years. AE 6 is presented by graphs of omnidirectional integral flux as a function of L shell, the ambient magnetic field B, and the energy E. Results of orbital integrations for altitudes from 150 n.m. to 18,000 n.m. are given for circular orbits with four different inclinations, using the AE 6 and the AE 4 solar maximum models for the inner and outer zones, respectively. The derivation of AE 6 is described, and a brief comparison is given of the radial profiles of equatorial fluxes from several related models. A short summary of the associated computer programs is included