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ABSTRACT We present the results of a deep wide-field near-infrared survey of the entire Pleiades cluster recently released as part of the UKIRT Infrared Deep Sky Survey (UKIDSS) Galactic Clusters Survey (GCS) Data Release 9 (DR9). We have identified a sample of ∼1000 Pleiades cluster member candidates combining photometry in five near-infrared passbands and proper motions derived from the multiple epochs provided by the UKIDSS GCS DR9. We also provide revised membership for all previously published Pleiades low-mass stars and brown dwarfs in the past decade recovered in the UKIDSS GCS DR9 Pleiades survey based on the new photometry and astrometry provided by the GCS. We find no evidence of K-band variability in the Pleiades members larger than ∼0.08 mag. In addition, we infer a substellar binary frequency of 22-31 per cent in the 0.075-0.03 M⊙ range for separations less than ∼100 au. We employed two independent but complementary methods to derive the cluster luminosity and mass functions: a probabilistic analysis and a more standard approach consisting of stricter astrometric and photometric cuts. We found that the resulting luminosity and mass functions obtained from both methods are very similar. We derive the Pleiades mass function in the 0.6-0.03 M⊙ range and found that it is best reproduced by a lognormal representation with a mean characteristic mass of 0.20 ± 0.05 M⊙, in agreement with earlier studies and the extrapolation of the field mass function. [ABSTRACT FROM AUTHOR]

ABSTRACT We present the results of a deep wide-field near-infrared survey of the entire Pleiades cluster recently released as part of the UKIRT Infrared Deep Sky Survey (UKIDSS) Galactic Clusters Survey (GCS) Data Release 9 (DR9). We have identified a sample of ∼1000 Pleiades cluster member candidates combining photometry in five near-infrared passbands and proper motions derived from the multiple epochs provided by the UKIDSS GCS DR9. We also provide revised membership for all previously published Pleiades low-mass stars and brown dwarfs in the past decade recovered in the UKIDSS GCS DR9 Pleiades survey based on the new photometry and astrometry provided by the GCS. We find no evidence of K-band variability in the Pleiades members larger than ∼0.08 mag. In addition, we infer a substellar binary frequency of 22-31 per cent in the 0.075-0.03 M⊙ range for separations less than ∼100 au. We employed two independent but complementary methods to derive the cluster luminosity and mass functions: a probabilistic analysis and a more standard approach consisting of stricter astrometric and photometric cuts. We found that the resulting luminosity and mass functions obtained from both methods are very similar. We derive the Pleiades mass function in the 0.6-0.03 M⊙ range and found that it is best reproduced by a lognormal representation with a mean characteristic mass of 0.20 ± 0.05 M⊙, in agreement with earlier studies and the extrapolation of the field mass function. [ABSTRACT FROM AUTHOR]

The Pan-STARRS1 survey has obtained multi-epoch imaging in five bands (Pan-STARRSI gPI, rPI, iPI, zPI, and yPI) on 12 "Medium-Deep fields," each of which spans a 3°73 circle. For the period between 2009 April and 2011 April these fields were observed 50-200 times. Using a reduced proper motion diagram, we have extracted a list of 47 white dwarf (WD) candidates whose Pan-STARRS 1 astrometry indicates a non-zero proper motion at the 6σ level, with a typical 1σ proper motion uncertainty of 10 mas yr-1. We also used astrometry from the Sloan Digital Sky Survey (when available) and USNO-B to assess our proper motion fits. None of the WD candidates exhibits evidence of statistically significant parallaxes, with a typical 1σ uncertainty of 8 mas. Twelve of these candidates are known WDs, including the high proper motion (1".7 yr-1) WD LHS 291. We confirm seven more objects as WDs through optical spectroscopy. Based on the Pan-STARRS1 colors, ten of the stars are likely to be cool WDs with 4170 K < Teff < 5000 K and cooling ages ≈ 8 Gyr. Based on their kinematics, these objects are likely thick disk WDs, but a subset may belong to the halo. Our current sample represents only a small fraction of the Pan-STARRS1 data. With continued coverage from the Medium-Deep Field Survey and the 3π survey, Pan-STARRS1 should find many more high proper motion WDs that are part of the old thick disk and halo. [ABSTRACT FROM AUTHOR]

We associate 132 low-mass ultracool dwarfs in the southern hemisphere as candidate members of five moving groups (MGs) using photometric and astrometric selection techniques. Of these objects, we present high-resolution spectroscopy for seven candidates and combine these with previous measurements from the literature to determine spectral types and radial velocities. We thus constrain distance and space motion spectroscopically, allowing the kinematic membership of the MGs to be assessed. Possible membership of MGs has allowed ages and metallicities to be constrained for these objects and evolutionary models have been used to estimate their mass. We estimate that up to ∼75 of our candidate MG members should be genuine, and discuss future work that will confirm and exploit this major new sample. [ABSTRACT FROM AUTHOR]

Two methods were used to measure in-stream nitrogen loss in the Connecticut River during studies conducted in April and August 2005. A mass balance on nitrogen inputs and output for two study reaches (55 and 66 km), at spring high flow and at summer low flow, was computed on the basis of total nitrogen concentrations and measured river discharges in the Connecticut River and its tributaries. In a 10.3 km subreach of the northern 66 km reach, concentrations of dissolved N2 were also measured during summer low flow and compared to modeled N2 concentrations (based on temperature and atmospheric gas exchange rates) to determine the measured “excess” N2 that indicates denitrification. Mass balance results showed no in-stream nitrogen loss in either reach during April 2005, and no nitrogen loss in the southern 55 km study reach during August 2005. In the northern 66 km reach during August 2005, however, nitrogen output was 18% less than the total nitrogen inputs to the reach. N2 sampling results gave an estimated rate of N2 production that would remove 3.3% of the nitrogen load in the river over the 10.3 km northern sub-reach. The nitrogen losses measured in the northern reach in August 2005 may represent an approximate upper limit for nitrogen attenuation in the Connecticut River because denitrification processes are most active during warm summer temperatures and because the study was performed during the annual low-flow period when total nitrogen loads are small. [ABSTRACT FROM AUTHOR]

The article examines short-term memory of mentally retarded and nonretarded persons. They were compared in four experiments in an attempt to relate short-term memory deficit to control processes. It has been stated that the results of a few studies can be interpreted as evidence for structural memory deficits of retarded persons.

The article cites a study on discrimination learning, memory, and transfer capacity of institutionalized mentally retarded persons in the U.S. The study aimed to provide information on the subjects' trainability. Overall, the higher functioning subjects learned more rapidly compared to lower functioning ones. In addition, interproblem transfer was considered negligible at all levels of retardation.

In a newborn twin with haemolytic anaemia an unstable fetal haemoglobin was found to be the cause. The anaemia improved spontaneously with the disappearance of the fetal haemoglobin. The new Hb F (alpha2gamma2) variant was shown to have a glycine at position 130 of the 146 residues of the gamma chain. This portion is inside the globin molecule and in all known normal globins it is occupied by a residue with a bulky hydrophobic side chain. Its replacement by glycine which has no side chain would be expected to cause instability. The human gamma-chains may either have a glycine or an alanine at position 136. Evidence is brought forward to suggest that in the abnormal chain position 136 is occupied by glycine. [ABSTRACT FROM PUBLISHER]

Incomplete expression of human haemoglobin beta-chains at birth may lead to difficulty in the early demonstration of an inherited beta-chain variant. In this case, the rare unstable variant, Hb Tacoma beta30 (B12) arg leads to ser, although not present in cord blood in sufficient amounts to be easily detected by routine electrophoretic techniques, was readily shown to be present by the striking inclusions provoked by prolonged incubation of the neonatal red cells with new methylene blue. [ABSTRACT FROM PUBLISHER]

The article presents the matters referred to the Constitution and Bylaws Committee by action at the Annual Meeting of the American Association on Mental Deficiency in the U.S. An instruction was given by the Constitution and Bylaws Committee to make a study toward making the necessary change in the name of the Association from the American Association on Mental Retardation.

WISE J085510.83-071442.5 (hereafter, WISE 0855-07) is the coolest Y dwarf known to date and is located at a distance of 2.31 ± 0.08 pc, giving it the fourth largest parallax of any known star or brown dwarf system. We report deep z-band observations of WISE 0855-07 using FORS2 on UT1/Very Large Telescope. We do not detect any counterpart to WISE 0855-07 in our z-band images and estimate a brightness upper limit of AB mag > 24.8 (Fν < 0.45 μJy) at 910 ± 65 nm with 3σ confidence. We combine our z-band upper limit with previous near- and mid-infrared photometry to place constraints on the atmospheric properties of WISE 0855-07 via comparison to models which implement water clouds in the atmospheres of Teff < 300 K substellar objects. We find that none of the available models that implement water clouds can completely reproduce the observed spectral energy distribution of WISE 0855-07. Every model significantly disagrees with the (3.6 μm/4.5 μm) flux ratio and at least one other bandpass. Since methane is predicted to be the dominant absorber at 3-4 μm, these mismatches might point to an incorrect or incomplete treatment of methane in current models. We conclude that (a) WISE0855-07 has Teff ∼ 200-250 K, (b) <80% of its surface is covered by clouds, and (c) deeper observations, and improved models of substellar evolution, atmospheres, clouds, and opacities will be necessary to better characterize this object. [ABSTRACT FROM AUTHOR]

Streambed-sediment samples were collected in the Southern Rocky Mountains physiographic province in the Upper Colorado River Basin in Colorado to characterize the occurrence and distribution of trace elements in mined and nonmined areas of the basin. During October 1995 and September 1996, streambed sediment was collected at 37 sites, and thesamples were analyzed for trace elements. The ranges in concentrations of As, Cd, Cu, Pb, and Zn at mining sites generally were orders ofmagnitude higher than the ranges of concentrations at nonmining sites. Sampling sites located in two predominant rock types in mining areas were not significantly different (p > 0.05) for concentrations of As, Cd, Pb, and Zn. Cu was significantly different (p < 0.05) betweensites in the two predominant rock types. Concentrations of As, Cd, Cu, Pb, and Zn were not significantly different (p > 0.05) between main-stem sites and tributary sites. Concentrations of As, Cd, Cu, Pb, and Zn exceeded established guidelines for adverse effects on aquatic biota at some sites in the study area. The patterns in concentrationsof Cd and Zn, Cd and Pb, and Pb and Zn were highly correlated to oneanother in this study. Concentrations of trace elements in the <63-mu m fraction were higher than in the total particle-size fraction analysis. Comparison of reference sites to sites affected by a mine source indicated that trace-element concentrations initially increased downstream of the source and then gradually decreased in concentration with distance from the source. [ABSTRACT FROM AUTHOR]

Measurements of carbon monoxide, nitrogen oxides, PM10 sulphur dioxide and ozone from four UK National Automatic Urban NetworkStations have been analysed for the year 1994. All of the sites are urban background, with two in the same city (Birmingham Centre and Birmingham East) and the other two also in cities in the centre of England, Leicester and Leeds, respectively 58 and 154 km from Birmingham.Expressed as cumulative frequency distributions and median concentrations, the pollution climates of the four sites are relatively similar, with differences between Birmingham Centre and Birmingham East as large as those between Birmingham and the other cities. Sulphur dioxide, which does not have an appreciable road traffic source, behaves differently, especially in Leeds, which is adjacent to a number of major point sources. However, when monthly hourly maxima and exceedencesof health-related threshold concentrations are examined, the sites behave differently and relationships between them are much poorer, even for the two sites within the same city. It is concluded that network design needs to compromise between two extreme views. On the one hand, very high site density would be necessary to reflect all local conditions and provide adequate public information. On the other hand, concentrations are so spatially variable that the view may be taken that it is impossible to provide sufficient stations to monitor adequately, and that very few stations are all that is needed to give a general view of the pollution climate. Provided an adequate safety margin is built into ambient air quality standards, a high network densityis not essential due to the generally strong correlation of measurements at adjacent sites. [ABSTRACT FROM AUTHOR]

We present initial results from a wide-field (30,000 deg2) search for L/T transition brown dwarfs within 25 pc using the Pan-STARRS1 and Wide-field Infrared Survey Explorer (WISE) surveys. Previous large-area searches have been incomplete for L/T transition dwarfs, because these objects are faint in optical bands and have near-infrared (near-IR) colors that are difficult to distinguish from background stars. To overcome these obstacles, we have cross-matched the Pan-STARRS1 (optical) and WISE (mid-IR) catalogs to produce a unique multi-wavelength database for finding ultracool dwarfs. As part of our initial discoveries, we have identified seven brown dwarfs in the L/T transition within 9-15 pc of the Sun. The L9.5 dwarf PSO J140.2308+45.6487 and the T1.5 dwarf PSO J307.6784+07.8263 (both independently discovered by Mace et al.) show possible spectroscopic variability at the Y and J bands. Two more objects in our sample show evidence of photometric J-band variability, and two others are candidate unresolved binaries based on their spectra. We expect our full search to yield a well-defined, volume-limited sample of L/T transition dwarfs that will include many new targets for study of this complex regime. PSO J307.6784+07.8263 in particular may be an excellent candidate for in-depth study of variability, given its brightness (J = 14.2 mag) and proximity (11 pc). [ABSTRACT FROM AUTHOR]

The process of designing protected areas to represent all ecosystems in an area adequately is becoming increasingly sophisticated. To date freshwater aquatic ecosystems have seldom been considered in this process. How much of a difference does it make when they are considered as well? This study examined the conservation of riverine biodiversity within 17 assessment units contained by the catchment areas of five perennial rivers flowing through Kruger National Park and two seasonal rivers that are largely contained within this park. Physical river types, fish species and invertebrate families or genera were used as surrogates of riverine biodiversity. Conservation planning software was used to select an optimal set of planning units to represent and maintain riverine biodiversity. The current spatial configuration of Kruger National Park, largely an accident of history, is particularly poor when assessed against the objective of conserving riverine biodiversity. Several alternative layouts are examined. These options are theoretical since there is little current opportunity to reassign land uses in the region. This study shows that substantially improved layouts for both riverine and terrestrial biodiversity are possible, under the constraint of the same total area under protection. The study also shows that even these optimal layouts are only partially successful in efforts to conserve fully representative samples of riverine biodiversity. Because of the longitudinal connectivity of rivers, conservation strategies that extend beyond protected areas are essential. Explicit conservation visions, targets and strategies need to be included in integrated water resource management plans. Based on the results of this study, nine recommendations are provided for increasing the effectiveness of current and future protected areas in conserving riverine biodiversity. These are to use systematic conservation planning to make biodiversity benefits explicit; mend the disconnect between terrestrial and freshwater conservation; use multiple surrogates wherever possible; be strategic about the collection and management of primary data; strive for maximum hydrologic connectivity; resist development pressure; foster good relationships across park fences; where relevant, pursue multi-national cooperation at the basin scale; and engage the value debate and resolve awareness and capacity constraints. [Copyright &y& Elsevier]

We present the results of 3 years' experience of rapid pre-screening in cervical cytology. In our laboratory we rapidly pre-screen all smears. The performance of each primary screener can be assessed. In addition, the relative sensitivity and specificity of each rapid pre-screener can itself be continuously monitored using the final report as a yardstick. In our laboratory individual sensitivity of rapid pre-screening for the detection of high-grade abnormalities was in the range of 44-90% with an overall laboratory sensitivity of 69%. Specificity was in the range of 94-99% with an overall laboratory specificity of 98%. Rapid pre-screening allows checking of the checkers and pathologists and tends to promote uniformity in the assessment of smear adequacy. This form of continuous quality assurance is practical, convenient and acceptable to staff. [ABSTRACT FROM AUTHOR]