374 research outputs found
CONSOLIDATION IN THE FRESH FLORIDA GRAPEFRUIT PACKING INDUSTRY
First-order, homogeneous, stationary Markov models are used to compare patterns of adjustment among Florida fresh grapefruit packers between the 1970/71-1983/84 and 1987/88-1999/00 periods, and 1970/71-1994/95 and 1995/95-1999/00 periods, respectively. Despite sweeping aggregate trends impacting fresh produce markets, there was insufficient evidence to identify significant differences in the patterns of adjustment in the packing sector during the later time periods. Comparisons with actual firm numbers are indicative of an industry near equilibrium. While individual firms enter and exit the different states, currently there are no profound structural changes pointing to major concentration.Industrial Organization,
Fresh Grapefruit Supply-Chain Adjustments: Consolidation in Produce Packing?
This study evaluates long-term structural adjustments in fresh grapefruit packing under aggregate market pressures, including those from retail concentration. While individual firms enter and exit, Markov-model results are indicative of an industry near equilibrium with little expectation of change in the distribution of firm sizes given existing patterns of sector adjustment. Estimation of Lorenz curves and corresponding Gini coefficients fully support Markov analysis findings. Lags in the packing sector adjustment process in the face of sweeping forces of change in fresh produce markets are likely to put this sector at a relative disadvantage within the supply chain.Crop Production/Industries,
Downflow Limestone Beds for Treatment of Net-Acidic, Oxic, Iron-Laden Drainage from a Flooded Anthracite Mine, Pennsylvania, USA: 2. Laboratory Evaluation
Acidic mine drainage (AMD) containing elevated concentrations of dissolved iron and other metals can be neutralized to varying degrees by reactions with limestone in passive treatment systems. We evaluated the chemical and mineralogical characteristics and the effectiveness of calcitic and dolomitic limestone for the neutralization of net-acidic, oxic, iron-laden AMD from a flooded anthracite mine. The calcitic limestone, with CaCO3 and MgCO3 contents of 99.8 and \u3c0.1 wt%, respectively, and the dolomitic limestone, with CaCO3 and MgCO3 contents of 60.3 and 40.2 wt%, were used to construct a downflow treatment system in 2003 at the Bell Mine, a large source of AMD and baseflow to the Schuylkill River in the Southern Anthracite Coalfield, in east-central Pennsylvania. In the winter of 2002–2003, laboratory neutralization-rate experiments evaluated the evolution of effluent quality during 2 weeks of continuous contact between AMD from the Bell Mine and the crushed calcitic or dolomitic limestone in closed, collapsible containers (cubitainers). The cubitainer tests showed that: (1) net-alkaline effluent could be achieved with detention times greater than 3 h, (2) effluent alkalinities and associated dissolution rates were equivalent for uncoated and Fe(OH)3-coated calcitic limestone, and (3) effluent alkalinities and associated dissolution rates for dolomitic limestone were about half those for calcitic limestone. The dissolution rate data for the cubitainer tests were used with data on the volume of effuent and surface area of limestone in the treatment system at the Bell Mine to evaluate the water-quality data for the first 1.5 years of operation of the treatment system. These rate models supported the interpretation of field results and indicated that treatment benefits were derived mainly from the dissolution of calcitic limestone, despite a greater quantity of dolomitic limestone within the treatment system. The dissolution-rate models were extrapolated on a decadal scale to indicate the expected decreases in the mass of limestone and associated alkalinities resulting from the long-term reaction of AMD with the treatment substrate. The models indicated the calcitic limestone would need to be replenished approaching the 5-year anniversary of treatment operations to maintain net-alkaline effluent quality
Downflow Limestone Beds for Treatment of Net-Acidic, Oxic, Iron-Laden Drainage from a Flooded Anthracite Mine, Pennsylvania, USA: 2. Laboratory Evaluation
Acidic mine drainage (AMD) containing elevated concentrations of dissolved iron and other metals can be neutralized to varying degrees by reactions with limestone in passive treatment systems. We evaluated the chemical and mineralogical characteristics and the effectiveness of calcitic and dolomitic limestone for the neutralization of net-acidic, oxic, iron-laden AMD from a flooded anthracite mine. The calcitic limestone, with CaCO3 and MgCO3 contents of 99.8 and \u3c0.1 wt%, respectively, and the dolomitic limestone, with CaCO3 and MgCO3 contents of 60.3 and 40.2 wt%, were used to construct a downflow treatment system in 2003 at the Bell Mine, a large source of AMD and baseflow to the Schuylkill River in the Southern Anthracite Coalfield, in east-central Pennsylvania. In the winter of 2002–2003, laboratory neutralization-rate experiments evaluated the evolution of effluent quality during 2 weeks of continuous contact between AMD from the Bell Mine and the crushed calcitic or dolomitic limestone in closed, collapsible containers (cubitainers). The cubitainer tests showed that: (1) net-alkaline effluent could be achieved with detention times greater than 3 h, (2) effluent alkalinities and associated dissolution rates were equivalent for uncoated and Fe(OH)3-coated calcitic limestone, and (3) effluent alkalinities and associated dissolution rates for dolomitic limestone were about half those for calcitic limestone. The dissolution rate data for the cubitainer tests were used with data on the volume of effuent and surface area of limestone in the treatment system at the Bell Mine to evaluate the water-quality data for the first 1.5 years of operation of the treatment system. These rate models supported the interpretation of field results and indicated that treatment benefits were derived mainly from the dissolution of calcitic limestone, despite a greater quantity of dolomitic limestone within the treatment system. The dissolution-rate models were extrapolated on a decadal scale to indicate the expected decreases in the mass of limestone and associated alkalinities resulting from the long-term reaction of AMD with the treatment substrate. The models indicated the calcitic limestone would need to be replenished approaching the 5-year anniversary of treatment operations to maintain net-alkaline effluent quality
Perceptions Of School By Two Teenage Boys With Asperger Syndrome And Their Mothers: A Qualitative Study
This qualitative study aimed to develop an understanding of the challenges faced by teenage boys with Asperger syndrome and their mothers. A case study approach was used to collect data from two 13-year-old boys who have Asperger syndrome and their mothers in Queensland, Australia. Data were collected through the use of semi¬structured interviews. The words of the boys and their mothers provide a valuable insight into the personal experiences and feelings of the par¬ticipants. An inductive approach to data analysis identified four themes: (1) developmental differences; (2) problems associated with the general characteristics of Asperger syndrome (i.e. communication and social difficulties, restricted range of interests, a need for routine); (3) stress; and (4) 'masquerading'. The first three themes relate strongly to the current literature, but the emergence of masquerading is of particular interest in developing a fuller understanding of the experiences of individuals with Asperger syndrome at school
A biophysical model of prokaryotic diversity in geothermal hot springs
Recent field investigations of photosynthetic bacteria living in geothermal
hot spring environments have revealed surprisingly complex ecosystems, with an
unexpected level of genetic diversity. One case of particular interest involves
the distribution along hot spring thermal gradients of genetically distinct
bacterial strains that differ in their preferred temperatures for reproduction
and photosynthesis. In such systems, a single variable, temperature, defines
the relevant environmental variation. In spite of this, each region along the
thermal gradient exhibits multiple strains of photosynthetic bacteria adapted
to several distinct thermal optima, rather than the expected single thermal
strain adapted to the local environmental temperature. Here we analyze
microbiology data from several ecological studies to show that the thermal
distribution field data exhibit several universal features independent of
location and specific bacterial strain. These include the distribution of
optimal temperatures of different thermal strains and the functional dependence
of the net population density on temperature. Further, we present a simple
population dynamics model of these systems that is highly constrained by
biophysical data and by physical features of the environment. This model can
explain in detail the observed diversity of different strains of the
photosynthetic bacteria. It also reproduces the observed thermal population
distributions, as well as certain features of population dynamics observed in
laboratory studies of the same organisms
Fatty acids and stable isotopes (13C, 15N) in southern right whale Eubalaena australis calves in relation toage and mortality at Peninsula Valdes, Argentina
Baleen whales accumulate fat reserves during the summer to sustain reproduction while fasting in the winter. The southern right whale Eubalaena australis population that calves off PenĂnsula ValdĂ©s, Argentina, experienced high calf mortality events from 2003 to 2013 and poor nutritional states of mothers could be a contributing cause. Previous studies found that the population’s reproductive success is influenced by prey availability. Mothers unable to build sufficient fat reserves or feeding on prey with different nutritional value may fail to meet the demands of lactation. Milk is the only source of nutrients and energy for calves at ValdĂ©s, so their fatty acids (FAs) and stable isotopes should reflect their mother’s diet and feeding-ground locations. Here, we compared FA profiles and C and N stable isotopes of dead calves with those of living calves to evaluate the potential impact of maternal nutrition on calf survival. We found no differences in the FA composition of blubber in dead and living calves, indicating similar maternal diets. Likewise, the isotopic values of living and dead calves imply that their mothers had similar foraging ranges. However, FA composition was greatly affected by calf length, indicating effects of calf age and duration of nursing. These findings suggest that mothers of dead calves did not feed on different diets or feeding grounds compared to mothers of living calves. Future research should further assess the overall health and body condition of the ValdĂ©s southern right whale calves.Fil: MarĂłn, Carina Flavia. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas, FĂsicas y Naturales. Departamento de Diversidad BiolĂłgica y EcolĂłgica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Instituto de ConservaciĂłn de Ballenas; ArgentinaFil: Budge, Suzanne M.. Dalhousie University Halifax; CanadáFil: Ward, Robert E.. Utah State University; Estados UnidosFil: Valenzuela, Luciano Oscar. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Sociales. Departamento de ArqueologĂa. Laboratorio de EcologĂa Evolutiva Humana (Sede QuequĂ©n); Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Tandil; ArgentinaFil: Di Martino, MatĂas. Programa de Monitoreo Sanitario Ballena Franca Austral; ArgentinaFil: Ricciardi, Marcos. Instituto de ConservaciĂłn de Ballenas; ArgentinaFil: Sironi, Mariano. Instituto de ConservaciĂłn de Ballenas; Argentina. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas, FĂsicas y Naturales. Departamento de Diversidad BiolĂłgica y EcolĂłgica; Argentina. Programa de Monitoreo Sanitario Ballena Franca Austral; ArgentinaFil: Uhart, Marcela. Programa de Monitoreo Sanitario Ballena Franca Austral; Argentina. University of California; Estados UnidosFil: Seger, Jon. University Of Utah. Department Of Biology; Estados UnidosFil: Rowntree, Victoria J.. University Of Utah. Department Of Biology; Estados Unidos. Instituto de ConservaciĂłn de Ballenas; Argentina. Programa de Monitoreo Sanitario Ballena Franca Austral; Argentina. Whale Conservation Institute/Ocean Alliance; Estados Unido
Submillimetre line spectrum of the Seyfert galaxy NGC1068 from the Herschel-SPIRE Fourier Transform Spectrometer
The first complete submillimetre spectrum (190-670um) of the Seyfert 2 galaxy
NGC1068 has been observed with the SPIRE Fourier Transform Spectrometer onboard
the {\it Herschel} Space Observatory. The sequence of CO lines (Jup=4-13),
lines from water, the fundamental rotational transition of HF, two o-H_2O+
lines and one line each from CH+ and OH+ have been detected, together with the
two [CI] lines and the [NII]205um line. The observations in both single
pointing mode with sparse image sampling and in mapping mode with full image
sampling allow us to disentangle two molecular emission components, one due to
the compact circum-nuclear disk (CND) and one from the extended region
encompassing the star forming ring (SF-ring). Radiative transfer models show
that the two CO components are characterized by density of n(H_2)=10^4.5 and
10^2.9 cm^-3 and temperature of T=100K and 127K, respectively. The comparison
of the CO line intensities with photodissociation region (PDR) and X-ray
dominated region (XDR) models, together with other observational constraints,
such as the observed CO surface brightness and the radiation field, indicate
that the best explanation for the CO excitation of the CND is an XDR with
density of n(H_2) 10^4 cm^-3 and X-ray flux of 9 erg s^-1 cm^-2, consistent
with illumination by the active galactic nucleus, while the CO lines in the
SF-ring are better modeled by a PDR. The detected water transitions, together
with those observed with the \her \sim PACS Spectrometer, can be modeled by an
LVG model with low temperature (T_kin \sim 40K) and high density (n(H_2) in the
range 10^6.7-10^7.9 cm^-3).Comment: Accepted for publication on the Astrophysical Journal, 30 August 201
Mechanical design and development of TES bolometer detector arrays for the Advanced ACTPol experiment
The next generation Advanced ACTPol (AdvACT) experiment is currently underway
and will consist of four Transition Edge Sensor (TES) bolometer arrays, with
three operating together, totaling ~5800 detectors on the sky. Building on
experience gained with the ACTPol detector arrays, AdvACT will utilize various
new technologies, including 150mm detector wafers equipped with multichroic
pixels, allowing for a more densely packed focal plane. Each set of detectors
includes a feedhorn array of stacked silicon wafers which form a spline profile
leading to each pixel. This is then followed by a waveguide interface plate,
detector wafer, back short cavity plate, and backshort cap. Each array is
housed in a custom designed structure manufactured from high purity copper and
then gold plated. In addition to the detector array assembly, the array package
also encloses cryogenic readout electronics. We present the full mechanical
design of the AdvACT high frequency (HF) detector array package along with a
detailed look at the detector array stack assemblies. This experiment will also
make use of extensive hardware and software previously developed for ACT, which
will be modified to incorporate the new AdvACT instruments. Therefore, we
discuss the integration of all AdvACT arrays with pre-existing ACTPol
infrastructure.Comment: 9 pages, 5 figures, SPIE Astronomical Telescopes and Instrumentation
conference proceeding
Explaining variable effects of an adaptable implementation package to promote evidence-based practice in primary care : a longitudinal process evaluation
This study is funded by the National Institute for Health Research (NIHR) [Programme Grants for Applied Research (Grant Reference Number RP-PG-1209-10040)] (https://www.nihr.ac.uk/).Background Implementing evidence-based recommendations is challenging in UK primary care, especially given system pressures and multiple guideline recommendations competing for attention. Implementation packages that can be adapted and hence applied to target multiple guideline recommendations could offer efficiencies for recommendations with common barriers to achievement. We developed and evaluated a package of evidence-based interventions (audit and feedback, educational outreach and reminders) incorporating behaviour change techniques to target common barriers, in two pragmatic trials for four “high impact” indicators: risky prescribing; diabetes control; blood pressure control; and anticoagulation in atrial fibrillation. We observed a significant, cost-effective reduction in risky prescribing but there was insufficient evidence of effect on the other outcomes. We explored the impact of the implementation package on both social processes (Normalisation Process Theory; NPT) and hypothesised determinants of behaviour (Theoretical Domains Framework; TDF). Methods We conducted a prospective multi-method process evaluation. Observational, administrative and interview data collection and analyses in eight primary care practices were guided by NPT and TDF. Survey data from trial and process evaluation practices explored fidelity. Results We observed three main patterns of variation in how practices responded to the implementation package. First, in integration and achievement, the package “worked” when it was considered distinctive and feasible. Timely feedback directed at specific behaviours enabled continuous goal setting, action and review, which reinforced motivation and collective action. Second, impacts on team-based determinants were limited, particularly when the complexity of clinical actions impeded progress. Third, there were delivery delays and unintended consequences. Delays in scheduling outreach further reduced ownership and time for improvement. Repeated stagnant or declining feedback that did not reflect effort undermined engagement. Conclusions Variable integration within practice routines and organisation of care, variable impacts on behavioural determinants, and delays in delivery and unintended consequences help explain the partial success of an adaptable package in primary care.Publisher PDFPeer reviewe
- …