Contextualising the bycatch 'problem' in the Olifants Estuary Small-Scale Gillnet Fishery using an Ecosystem Approach to Fisheries

Conventional fisheries management approaches have been shown, in many instances, to have been ineffective in dealing with complex conservation concerns such as bycatch. Greater considerations for broader-scale and holistic approaches, as proposed by the 'Ecosystem Approach to Fisheries' (EAF) and the 'balanced harvesting approach', are beginning to challenge some of the negative misconceptions around bycatch, especially in small-scale fisheries. The need for a more holistic approach to fisheries management, particularly in small-scale fisheries, in South Africa is highlighted by its commitment to an EAF and the recent Small-Scale Fisheries Policy, for which the Marine living Resource Act of 1998 provides the legal framework to implement. The case study of the Olifants estuary small-scale traditional gillnet fishing community, located on the west coast of South Africa, provides a particularly relevant example of a complex fishery requiring a holistic approach. Current regulations prohibit the harvesting or retention of any bycatch species. Fisheries management worldwide and in South Africa, generally view gillnet fisheries as destructive, due to the occurrence of bycatch and the fact that many of these bycatch species are considered overexploited, which has led to numerous attempts over the years to phase out the Olifants gillnet fishery. The purpose of this study was to, firstly, use an EAF framework to contextualise the issue of bycatch in the Olifants gillnet fishery, and secondly, to identify the relative contributions of all fisheriy sectors to the four key selected linefish species caught as bycatch by the fishery. An extensive review and analysis of available secondary data, as well as primary data collected for this study, have estimated, with acknowledged limitations, the magnitude of the exploitation by all known fisheries of these species. Key information from small-scale fisher interviews and community-monitoring data highlight the capture rate of key linefish species by this fishery. This is echoed by recent landings for 2012 indicating the relative contribution of the national beache seine and gillnet fishery to the overall catch of (Elf [Pomatomus saltatrix] - 26.94%; Silver Kob [Argyrosomus inodorus] - 0.88%; White Stumpnose [Rhabdosargus globiceps] - 1.05% - excluding the recreational sector). A significant finding of this study is the substantial levels of cross-sectorial exploitation of Silver Kob and White Stumpnose, and to a somewhat lesser extent Elf and White Steenbras

Critical evaluation of standard ratios of railroad analysis

Thesis (M.B.A.)--Boston University

Patterns of emergency admissions for ambulatory care sensitive conditions: : a spatial cross-sectional analysis of observational data

Objectives: To examine the spatial and temporal patterns of English general practices’ emergency admissions for Ambulatory Care Sensitive Conditions (ACSC). Design: Observational study of annual hospital admission data for ACSC emergency admissions at general practice level for all practices in England 2004 to 2017. Participants: All patients with an emergency admission to a National Health Service (NHS) hospital in England who were registered with an English GP practice. Main outcome measure: Practice level age and gender indirectly standardised ratios (ISARs) for emergency admissions for ACSC. Results: In 2017 41.8% of the total variation in ISARs across practices was between the 207 Clinical Commissioning Groups (the administrative unit for general practices) and 58.2% was across practices within CCGs. ACSC ISARs increased by 4.7% between 2004 and 2017 while those for conditions incentivised by the Quality and Outcomes Framework fell by 20.02%. Practice ISARs are persistent: practices with high rates in 2004 also had high rates in 2017. Standardising by deprivation as well as age and gender reduced the coefficient of variation of practice ISARs in 2017 by 22% Conclusions: There is persistent spatial pattern of emergency admissions for ACSC across England both within and across CCGs. We illustrate the reduction in ACSC emergency admissions across the study period for conditions incentivised by the QOF but find that this was not accompanied by a reduction in variation in these admissions across practices. The observed spatial pattern persists when admission rates are standardised by deprivation. The persistence of spatial clusters of high emergency admissions for ACSC within and across CCG boundaries suggests that policies to reduce potentially unwarranted variation should be targeted at practice level

Variable modes of larval development in the Polydora cornuta complex (Polychaeta: Spionidae) are directly related to stored sperm availability

Abstract Reproductive crosses between geographically separated populations of the nominal species, Polydora cornuta, support the hypothesis that the Florida/ Gulf of Mexico populations represent a single, potentially interbreeding lineage that is reproductively isolated from West Coast (California) and East Coast (Carolinas to Maine) populations. Previous research has indicated that California populations are reproductively compatible with worms from North Carolina but reproductively isolated from Maine populations. In spite of these species-level differences, all populations of this nominal species deposit egg capsules inside the female's tube that usually develop into three-chaetiger planktonic larvae measuring about 200 µm in length. Although adelphophagy (feeding upon unfertilized eggs within an egg capsule) has been reported in some populations of P. cornuta and in numerous other spionid polychaetes, the relationship between stored sperm in the female parent and the size of larvae within capsules has not been explored. We raised isolated female P. cornuta from three genetically and reproductively distinct populations (Florida, California and Maine) over a period of about 16 weeks and determined percent fertilization and larval size in successive spawnings over time until the females ran out of stored sperm. As each female used up stored sperm during successive spawnings, the percent of fertilized eggs per capsule declined and larval size at release increased. In some cases, the largest larvae produced by an isolated female were 114% larger than the smallest larvae produced by the same female. Larvae inside capsules containing unfertilized eggs fed upon these eggs and grew larger than larvae that did not have unfertilized eggs to feed upon. The effects of producing larger larvae following stored sperm depletion were completely reversed by transfer of fresh spermatophores to the isolated females. Variable larval size produced by a single female worm (poecilogony) may therefore be a result of stored sperm limitations rather than a genetically determined reproductive strategy in this species complex

Flame propagation in fuel oil sprays

http://www.archive.org/details/flamepropagation00riceU.S. Navy (U.S.N.) authors.Approved for public release; distribution is unlimited

Differences in Shade Tolerance Help Explain Varying Success of Two Sympatric Alnus Species

Alnus maritima and Alnus serrulata are riparian shrubs that occur in similar habitats in the southern and eastern United States.Alnus serrulata is abundant throughout this range, but A. maritima is rare, occurring only in small populations in Oklahoma and Georgia and on the Delmarva Peninsula. Alnus maritima is more resistant than A. serrulata to water and temperature stresses, but the degree to which insolation influences the restricted distribution of A. maritima is unknown. Our goals were to characterize the shade tolerance of A. maritima and A. serrulata and determine whether differences in shade tolerance could help explain the differing ecological success of the two species. Measurements in nature showed that leaves of A. serrulatahave greater concentrations of chlorophyll than do leaves of A. maritima, and a greater percentage of A. serrulata inhabit shaded sites. Two experiments evaluating the resistance of seedlings to light‐deficit stress revealed that A. maritima had a greater photosynthetic capacity and grew more quickly than A. serrulata in full sunlight. In shade, survival of seedlings was lower and reductions in photosynthesis and growth were greater for A. maritima than for A. serrulata. We conclude that A. serrulata is tolerant and A. maritima is intolerant of shade. Moreover, we conclude that shade intolerance strongly restricts the potential niches of A. maritima within the region where the shade‐tolerant A. serrulata is comparatively abundant

Honeaite, a new gold-thallium-telluride from the Eastern Goldfields, Yilgarn Craton, Western Australia

Honeaite, ideal formula Au3TlTe2, is a new mineral from the late Archaean Karonie gold deposit, Eastern Goldfields province, Western Australia. Honeaite is found with native gold, tellurobismuthite, petzite, hessite, calaverite, melonite, mattagamite, frohbergite, altaite, pyrrhotite and molybdenite. These minerals are concentrated in microvughs and microfractures mainly within areas of prehnite alteration of amphibolite. The mineralisation appears to have been deposited under greenschistfacies conditions at lower temperatures than most gold deposits in the Eastern Goldfields. Single-crystal X-ray studies identified the structure of honeaite as orthorhombic, space group Pbcm, and unit cell parameters a = 8.9671(4) Å, b = 8.8758(4) Å, c = 7.8419(5) Å, V = 624.14(6) Å3 (Z = 4). The strongest reflections of the calculated powder X-ray diffraction pattern are [d in Å (I rel)(hkl)]: 2.938(100)(022), 2.905 (39,8)(322, 411), 2.989 (31)(300), 2.833 (23)(310), 1.853 (17)(332). Electron-microprobe analysis (EDS mode) gave (wt%) Au 56.33, Tl 19.68, Te 24.30, total 100.31, leading to an empirical formula (based on 2 Te apfu) of Au3.00Tl1.01Te2.00. Honeaite is black with a metallic lustre and no observed cleavage. The calculated density is 11.18 g/cm3. In reflected plane-polarized light it is slightly bluish grey. Between crossed polars it is weakly anisotropic with dark brown to dark blue rotation tints. Reflectance values in air and in oil are given. Honeaite is named after the late Russell M. Honea (1929–2002).© 2016 E. Schweizerbart'sche Verlagsbuchhandlung, D-70176 Stuttgart. This document is the author's final accepted version of the journal article. You are advised to consult the publisher's version if you wish to cite from it