Ichthyofaunal Diversification and Distribution in the Ozark Stream in Northcentral Arkansas

The distribution and diversity of the ichthyofauna of Arkansas are poorly known. This study is part of a continuing effort to elucidate the natural history of Arkansas. Big Creek is a relatively small, clear, cool-water stream in the Ozark Plateau of northcentral Arkansas. Big Creek and its tributaries drain into Lake Norfork, an impoundment on North Fork River. A total of 6,779 fish of 30 species was collected. Dominant pool species included Notropis boops, Fundulus catenatus, F. olivaceus, Labidesthes sicculus, and Campostoma anomalum; dominant riffle species included Etheostoma spectabile, E. caeruleum, Notropis boops, Fundulus catenatus, and Campostoma anomalum. The numerical standing crop ranged from 1.3 to 2.6 fish/m 2 in the pools and riffles, respectively. The relative uniformity of substrate and soil types throughout the watershed, and the absence of rooted aquatic plants, limited the diversity of species found. The concomitant reduction in competition and predation probably explains the relatively large numerical standing crop

SOUTHERNMOST OCCURRENCE OF THE SUWANNEE COOTER, PSEUDEMYS CONCINNA SUWANNIENSIS (TESTUDINES: EMYDIDAE)

The Suwannee Cooter, Pseudemys concinna suwanniensis, the largest member of the speciose turtle family Emydidae, inhabits a small number of rivers that drain into the northeastern Gulf of Mexico along the northwest coast of Florida from just west of Tallahassee to just south of Tampa. The status of this state-protected subspecies in the southernmost of these rivers, the Alafia, is unknown and hence of conservation concern. We provide recent evidence confirming that a reproducing population still exists in this river, and review available specimens and both published and unpublished records documenting the southern limit of distribution. At least within the eastern United States, our observations also extend confirmed knowledge of the geographic occurrence of hatchling turtles overwintering in the nest southward by 285 km

Exploring the relative importance of factors that influence the job retention of social care staff working in intellectual disability services

We wanted to find out what would help care staff to stay in their jobs. The most important thing for them was getting on well with the person they supported. The next most important thing was their pay. These results can be used to find ways to help staff stay in their jobs. This is important to make sure that people with a learning disability get good support. Abstract: Background: High staff turnover presents a challenge to the provision of good quality community-based support to people with an intellectual disability. While recent research has identified factors that are thought to be important for staff retention, their relative importance to social care staff is unknown. The aim of this study was to address this gap. Methods: 205 social care staff who worked in intellectual disability services completed an online questionnaire that asked them to: rank factors that had been previously identified as influencing staff retention in order of importance; identify the extent to which their most important factor was met by their organisation (fulfilment score); and rate their recent job-seeking intentions. Findings: The most important factor overall was the relationship of the staff member with the person they supported. This was also identified as the most important factor by the most participants, followed by pay. All of the factors, with the exception of “benefits” (such as pensions), were rated by at least one person as the most important factor. A significant negative relationship was found between fulfilment score and job-seeking score; that is, the lower the former, the more the person agreed that they had been seeking a new job. Conclusion: The results suggest that interventions to improve staff retention should take account of differences in staff views about which work-related factors are most important to them; use multi-component approaches where possible; prioritise staff pay; and help ensure that staff relationships with those they support are positive and fulfilling

DISTRIBUTION AND STATUS OF THE SUWANNEE COOTER, PSEUDEMYS CONCINNA SUWANNIENSIS, IN THE ALAFIA RIVER (HILLSBOROUGH COUNTY, FLORIDA, USA)

The Suwannee Cooter, Pseudemys concinna suwanniensis, is a geographically limited turtle of conservation concern that inhabits Florida rivers draining into the northeastern Gulf of Mexico. Threats impacting its conservation status include take for human consumption, predation of turtles and nests, loss or degradation of nesting and basking habitat, water quality degradation, and boat strikes. Our surveys revealed that the Alafia River, which drains into Hillsborough Bay (northeastern Tampa Bay), is likely the stronghold of the southern distribution of P. c. suwanniensis. Multiple survey methods during 2015-2020 revealed that a substantial population of Suwannee Cooters inhabits much of this blackwater river system, including the main channel and at least one of its two primary tributaries. GIS analysis showed that more than half of the shoreline within the occupied extent is currently protected by conservation lands, although additional protection of private lands and improved habitat management protocols are needed to assure the population’s conservation

Multimode bolometer development for the PIXIE instrument

The Primordial Inflation Explorer (PIXIE) is an Explorer-class mission concept designed to measure the polarization and absolute intensity of the cosmic microwave background. In the following, we report on the design, fabrication, and performance of the multimode polarization-sensitive bolometers for PIXIE, which are based on silicon thermistors. In particular we focus on several recent advances in the detector design, including the implementation of a scheme to greatly raise the frequencies of the internal vibrational modes of the large-area, low-mass optical absorber structure consisting of a grid of micromachined, ion-implanted silicon wires. With $\sim30$ times the absorbing area of the spider-web bolometers used by Planck, the tensioning scheme enables the PIXIE bolometers to be robust in the vibrational and acoustic environment at launch of the space mission. More generally, it could be used to reduce microphonic sensitivity in other types of low temperature detectors. We also report on the performance of the PIXIE bolometers in a dark cryogenic environment.Comment: 10 pages, 7 figure

Movement of Axoplasmic Organelles on Actin Filaments from Skeletal Muscle

It was recently shown that, in addition to the well-established microtubule-dependent mechanism, fast transport of organelles in squid giant axons also occurs in the presence of actin filaments [Kuznetsov et al., 1992, Nature 356:722-725]. The objectives of this study were to obtain direct evidence of axoplasmic organelle movement on actin filaments and to demonstrate that these organelles are able to move on skeletal muscle actin filaments. Organelles and actin filaments were visualized by video-enhanced contrast differential interference contrast (AVEC-DIC) microscopy and by video intensified fluorescence microscopy. Actin filaments, prepared by polymerization of monomeric actin purified from rabbit skeletal muscle, were stabilized with rhodamine-phalloidin and adsorbed to cover slips. When axoplasm was extruded on these cover slips in the buffer containing cytochalasin B that prevents the formation of endogenous axonal actin filaments, organelles were observed to move at the fast transport rate. Also, axoplasmic organelles were observed to move on bundles of actin filaments that were of sufficient thickness to be detected directly by AVEC-DIC microscopy. The range of average velocities of movement on the muscle actin filaments was not statistically different from that on axonal filaments. The level of motile activity (number of organelles moving/min/field) on the exogenous filaments was less than on endogenous filaments probably due to the entanglement of filaments on the cover slip surface. We also found that calmodulin (CaM) increased the level of motile activity of organelles on actin filaments. In addition, CaM stimulated the movement of elongated membranous organelles that appeared to be tubular elements of smooth endoplasmic reticulum or extensions of prelysosomes. These studies provide the first direct evidence that organelles from higher animal cells such as neurons move on biochemically defined actin filaments

Book Reviews

TO SECURE THESE RIGHTS The Report of the President\u27s Committee on Civil Rights with An Introduction by Charles S. Wilson, Committee Chairman. New York: Simon and Schuster, 1947. Pp. xii, 178. $1.00.. ====================== ROSCOE POUND By Paul Sayre Iowa City: College of Law Committee State University of Iowa, 1948. Pp. 412.$4.50. ====================== A NATIONAL POLICY FOR THE OIL INDUSTRY By Eugene V. Rostow New Haven: Yale University Press, 1948. Pp. XVI, 173. $2.50. ===================== THE TRADE OF NATIONS By Michael A. Heilperin New York: Alfred A. Knopf, 1947. Pp. xix, 234.$3.00. ==================== AMERICA\u27S ECONOMIC SUPREMACY By Brooks Adams New York: Harper & Brothers, Inc., 1947. Pp. 194. $2.50