2,484 research outputs found
Mercury Levels in Marine and Estuarine Fishes of Florida 1989–2001. 2nd edition revised
The Florida Fish and Wildlife Conservation Commission’s Florida Marine Research Institute (FWC-FMRI) has
examined total mercury levels in muscle tissue from a variety of economically and ecologically important species
as part of an ongoing study to better understand mercury contamination in marine fishes.The FWC-FMRI Mercury
Program is one of the most comprehensive programs in the United States for monitoring mercury levels in
marine and estuarine fishes. Because mercury, a toxic metallic element, has been shown to bioaccumulate in fish
tissue, humans consuming fish can potentially consume significant levels of mercury.We examined the concentration
of total mercury in 6,806 fish, representing 108 species from 40 families. Species represented all major trophic
groups, from primary consumers to apex predators.The majority of individuals we examined contained low concentrations
of mercury, but concentrations in individual fish varied greatly within and among species. Species
with very low mean or median mercury concentrations tended to be planktivores, detritivores, species that feed
on invertebrates, or species that feed on invertebrates and small fish prey.Apex predators typically had the highest
mercury concentrations. In most species, mercury concentration increased as fish size increased. Sampling
in Florida waters is continuing, and future research relating mercury levels to fish age, feeding ecology, and the
trophic structure of Florida’s marine and estuarine ecosystems will help us better understand concentrations of
this element in marine fishes. (64pp.
A Water Quality Survey
Representative factors influencing water quality in the Albert Lea, Minnesota area were chosen as to assess water quality and changes in the watershed which has been described as an earlier valley of the Shell Rock River.
Parameters representative of chemical, bacterial, and thermal pollution were, respectively, total phosphorous, total and fecal coliform counts, and temperature. Statistical analysis has revealed that significant differences in some parameters measured do exist when various sampling stations of a given sampling date are compared. Statistical analysis also has indicated that correlations do exist between fluctuation patterns when all sampling stations of a given sampling date are examined. Correlations between parameters and their fluctuation patterns were relatively low
Reliability History and Improvements to the ANL 50 MEV H- Accelerator
The H- Accelerator consists of a 750 keV Cockcroft Walton preaccelerator and
an Alvarez type 50 MeV linac. The accelerator has been in operation since 1961.
Since 1981, it has been used as the injector for the Intense Pulsed Neutron
Source (IPNS), a national user facility for neutron scattering. The linac
delivers about 3.5x1012 H- ions per pulse, 30 times per second (30 Hz), for
multi-turn injection to a 450 MeV Rapid Cycling Synchrotron (RCS). IPNS
presently operates about 4,000 hours per year, and operating when scheduled is
critical to meeting the needs of the user community. For many years the IPNS
injector/RCS has achieved an average reliability of 95%, helped in large part
by the preaccelerator/linac which has averaged nearly 99%. To maintain and
improve system reliability, records need to show what each subsystem
contributes to the total down time. The history of source and linac subsystem
reliability, and improvements that have been made to improve reliability, will
be described. Plans to maintain or enhance this reliability for at least
another ten years of operation, will also be discussed.Comment: 3 pages, 1 figur
Ancient Amazonian populations left lasting impacts on forest structure
Amazonia contains a vast expanse of contiguous tropical forest and is influential in global carbon and hydrological cycles. Whether ancient Amazonia was highly disturbed or modestly impacted, and how ancient disturbances have shaped current forest ecosystem processes, is still under debate. Amazonian Dark Earths (ADEs), which are anthropic soil types with enriched nutrient levels, are one of the primary lines of evidence for ancient human presence and landscape modifications in settings that mostly lack stone structures and which are today covered by vegetation. We assessed the potential of using moderate spatial resolution optical satellite imagery to predict ADEs across the Amazon Basin. Maximum entropy modeling was used to develop a predictive model using locations of ADEs across the basin and satellite‐derived remotely sensed indices. Amazonian Dark Earth sites were predicted to be primarily along the main rivers and in eastern Amazonia. Amazonian Dark Earth sites, when compared with randomly selected forested sites located within 50 km of ADE sites, were less green canopies (lower normalized difference vegetation index) and had lower canopy water content. This difference was accentuated in two drought years, 2005 and 2010. This is contrary to our expectation that ADE sites would have nutrient‐rich soils that support trees with greener canopies and forests on ADE soils being more resilient to drought. Biomass and tree height were lower on ADE sites in comparison with randomly selected adjacent sites. Our results suggested that ADE‐related ancient human impact on the forest is measurable across the entirety of the 6 million km2 of Amazon Basin using remotely sensed data
Socially Distant Health Care
The COVID-19 pandemic has elucidated many problems within the American health care system, chief among them the continuing access-to-care issue. Though the Affordable Care Act increased access to health insurance, the current pandemic has demonstrated that health insurance alone is not enough. Communities need access to health care providers. Indeed, many fully insured Americans across the country are experiencing what many have faced on a daily basis: the inability to access a health care provider Rural areas and communities of color regularly battle an inability to obtain care from health care professionals and have done so for many years. Much of the care demanded during the pandemic related to COVID-19 itself; but the pandemic also created access-to-care problems due to quarantines and shut-downs instituted to slow its spread. These measures have prevented millions from receiving necessary care for chronic diseases, simple injuries, and mental health needs, among others. Despite the tragic consequences of the COVID-19 pandemic, one of the bright spots has been state and federal responses designed to increase access to health care providers. One of the most important mechanisms that governments have employed to increase access to care has been telehealth. Though telehealth has been possible for decades, the federal government and many state governments maintain salient legal barriers to its use. Congress recently considered the Protecting Access to Post-COVID-19 Telehealth Act of 2021, which seeks to remove some barriers to accessing telehealth. Against this backdrop of political hungerfor continued improvement in telehealth access, this Article explores the policy experimentation catalyzed by the COVID-19 pandemic to make specific policy prescriptions aimed at alleviating both acute and chronic access-to-care issues. It argues that, following the pandemic, federal agencies and states should continue to dismantle barriers to telehealth as an important toolfor increasing access to health care providers among residents of rural areas and communities of color that have historically lacked reliable access to providers. Importantly, governments at both levels should make permanent many of the temporary policies they have instituted to improve access to telehealth and, therefore, health care more generally
Effects of live-bait shrimp trawling on seagrass beds and fish bycatch in Tampa Bay, Florida
The use of live shrimp for bait in
recreational fishing has resulted in
a controversial fishery for shrimp in
Florida. In this fishery, night collections
are conducted over seagrass
beds with roller beam trawls to capture
live shrimp, primarily pink
shrimp, Penaeus duorarum. These
shrimp are culled from the catch on
sorting tables and placed in onboard
aerated “live” wells. Beds of
turtlegrass, Thalassia testudinum,
a species that has highest growth
rates and biomass during summer
and lowest during the winter (Fonseca
et al., 1996) are predominant
areas for live-bait shrimp trawling
(Tabb and Kenny, 1969).
Our study objectives were 1) to
determine effects of a roller beam
trawl on turtlegrass biomass and
morphometrics during intensive
(up to 18 trawls over a turtlegrass
bed), short-term (3-hour duration)
use and 2) to examine the mortality
of bycatch finfish following capture
by a trawl
A Real-Time Energy Monitor System for the Ipns Linac
Injected beam energy and energy spread are critical parameters affecting the performance of our rapid cycling synchrotron (RCS). A real-time energy monitoring system is being installed to examine the H- beam out of the Intense Pulsed Neutron Source (IPNS) 50 MeV linac. The 200 MHz Alvarez linac serves as the injector for the 450 MeV IPNS RCS. The linac provides an 80 ms macropulse of approximately 3x1012 H- ions 30 times per second for coasting-beam injection into the RCS. The RCS delivers protons to a heavy-metal spallation neutron target for material science studies. Using a number of strip-line beam position monitors (BPMs) distributed along the 50 MeV transport line from the linac to the RCS, fast signals from the strip lines are digitized and transferred to a computer which performs an FFT. Corrections for cable attenuation and oscilloscope bandwidth are made in the frequency domain. Rectangular pulse train phasing (RPTP) is imposed on the spectra prior to obtaining the inverse transform (IFFT). After the IFFT, the reconstructed time-domain signal is analyzed for pulse width as it progresses along the transport line. Time-of-flight measurements of the BPM signals provide beam energy. Finally, using the 3-size measurement technique, the longitudinal emittance and energy spread of the beam are determined
Preliminary evidence for green, brown and black worlds in tropical western Africa during the Middle and Late Pleistocene
Preliminary evidence for green, brown and black worlds in tropical western Africa during the Middle and Late Pleistocene
Health equity and migrants in the Greater Mekong Subregion
Background: Migrant health is receiving increasing international attention, reflecting recognition of the health inequities experienced among many migrant populations and the need for health systems to adapt to diverse migrant populations. In the Greater Mekong Subregion (GMS) there is increasing migration associated with uneven economic integration and growth, socio-economic vulnerabilities, and disparities between countries. There has been limited progress, however, in improving migrant access to health services in the Subregion. This paper examines the health needs, access barriers, and policy responses to cross-border migrants in five GMS countries.
Methods: A review of published literature and research was conducted on migrant health and health service access in Cambodia, Lao People’s Democratic Republic, Myanmar, Thailand, and Viet Nam, as well as analysis of current migration trends and universal health coverage (UHC) indicators in the Subregion. The review included different migrant types: i.e. migrant workers, irregular migrants, victims of trafficking, refugees and asylum seekers, and casual cross-border migrants.
Results: There is substantial diversity in the capacity of GMS health systems to address migrant populations. Thailand has sought to enhance migrant health coverage, including development of migrant health policies/programs, bilateral migrant worker agreements, and migrant health insurance schemes; Viet Nam provides health protection for emigrant workers. Overall, however, access to good quality health care remains weak for many citizens in GMS countries let alone migrants. Migrant workers – and irregular migrants in particular – face elevated health risks yet are not adequately covered and incur high out-of-pocket (OOP) payments for health services.
Conclusions: UHC implies equity: UHC is only achieved when everyone has the opportunity to access and use good-quality health care. Efforts to achieve UHC in the GMS require deliberate policy decisions to include migrants. The emergence of the UHC agenda, and the focus on migrant health among policy makers and partners, present an opportunity to tackle barriers to health service access, extend coverage, and strengthen partnerships in order to improve migrant health. This is an opportune time for GMS countries to develop migrant-inclusive health systems
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